Commit Graph

27354 Commits

Author SHA1 Message Date
Peter Zijlstra c28d62cf52 locking/rtmutex: Handle non enqueued waiters gracefully in remove_waiter()
In -RT task_blocks_on_rt_mutex() may return with -EAGAIN due to
(->pi_blocked_on == PI_WAKEUP_INPROGRESS) before it added itself as a
waiter. In such a case remove_waiter() must not be called because without a
waiter it will trigger the BUG_ON() statement.

This was initially reported by Yimin Deng. Thomas Gleixner fixed it then
with an explicit check for waiters before calling remove_waiter().

Instead of an explicit NULL check before calling rt_mutex_top_waiter() make
the function return NULL if there are no waiters. With that fixed the now
pointless NULL check is removed from rt_mutex_slowlock().

Reported-and-debugged-by: Yimin Deng <yimin11.deng@gmail.com>
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/CAAh1qt=DCL9aUXNxanP5BKtiPp3m+qj4yB+gDohhXPVFCxWwzg@mail.gmail.com
Link: https://lkml.kernel.org/r/20180327121438.sss7hxg3crqy4ecd@linutronix.de
2018-03-28 23:01:30 +02:00
Alexei Starovoitov c4f6699dfc bpf: introduce BPF_RAW_TRACEPOINT
Introduce BPF_PROG_TYPE_RAW_TRACEPOINT bpf program type to access
kernel internal arguments of the tracepoints in their raw form.

>From bpf program point of view the access to the arguments look like:
struct bpf_raw_tracepoint_args {
       __u64 args[0];
};

int bpf_prog(struct bpf_raw_tracepoint_args *ctx)
{
  // program can read args[N] where N depends on tracepoint
  // and statically verified at program load+attach time
}

kprobe+bpf infrastructure allows programs access function arguments.
This feature allows programs access raw tracepoint arguments.

Similar to proposed 'dynamic ftrace events' there are no abi guarantees
to what the tracepoints arguments are and what their meaning is.
The program needs to type cast args properly and use bpf_probe_read()
helper to access struct fields when argument is a pointer.

For every tracepoint __bpf_trace_##call function is prepared.
In assembler it looks like:
(gdb) disassemble __bpf_trace_xdp_exception
Dump of assembler code for function __bpf_trace_xdp_exception:
   0xffffffff81132080 <+0>:     mov    %ecx,%ecx
   0xffffffff81132082 <+2>:     jmpq   0xffffffff811231f0 <bpf_trace_run3>

where

TRACE_EVENT(xdp_exception,
        TP_PROTO(const struct net_device *dev,
                 const struct bpf_prog *xdp, u32 act),

The above assembler snippet is casting 32-bit 'act' field into 'u64'
to pass into bpf_trace_run3(), while 'dev' and 'xdp' args are passed as-is.
All of ~500 of __bpf_trace_*() functions are only 5-10 byte long
and in total this approach adds 7k bytes to .text.

This approach gives the lowest possible overhead
while calling trace_xdp_exception() from kernel C code and
transitioning into bpf land.
Since tracepoint+bpf are used at speeds of 1M+ events per second
this is valuable optimization.

The new BPF_RAW_TRACEPOINT_OPEN sys_bpf command is introduced
that returns anon_inode FD of 'bpf-raw-tracepoint' object.

The user space looks like:
// load bpf prog with BPF_PROG_TYPE_RAW_TRACEPOINT type
prog_fd = bpf_prog_load(...);
// receive anon_inode fd for given bpf_raw_tracepoint with prog attached
raw_tp_fd = bpf_raw_tracepoint_open("xdp_exception", prog_fd);

Ctrl-C of tracing daemon or cmdline tool that uses this feature
will automatically detach bpf program, unload it and
unregister tracepoint probe.

On the kernel side the __bpf_raw_tp_map section of pointers to
tracepoint definition and to __bpf_trace_*() probe function is used
to find a tracepoint with "xdp_exception" name and
corresponding __bpf_trace_xdp_exception() probe function
which are passed to tracepoint_probe_register() to connect probe
with tracepoint.

Addition of bpf_raw_tracepoint doesn't interfere with ftrace and perf
tracepoint mechanisms. perf_event_open() can be used in parallel
on the same tracepoint.
Multiple bpf_raw_tracepoint_open("xdp_exception", prog_fd) are permitted.
Each with its own bpf program. The kernel will execute
all tracepoint probes and all attached bpf programs.

In the future bpf_raw_tracepoints can be extended with
query/introspection logic.

__bpf_raw_tp_map section logic was contributed by Steven Rostedt

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-03-28 22:55:19 +02:00
Linus Torvalds f67b15037a perf/hwbp: Simplify the perf-hwbp code, fix documentation
Annoyingly, modify_user_hw_breakpoint() unnecessarily complicates the
modification of a breakpoint - simplify it and remove the pointless
local variables.

Also update the stale Docbook while at it.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: <stable@vger.kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-28 17:41:50 +02:00
Shaohua Li b76354cdfe bpf: follow idr code convention
Generally we do a preload before doing idr allocation. This also help
improve the allocation success rate in memory pressure.

Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-03-27 22:23:08 +02:00
Kirill Tkhai 2f635ceeb2 net: Drop pernet_operations::async
Synchronous pernet_operations are not allowed anymore.
All are asynchronous. So, drop the structure member.

Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-27 13:18:09 -04:00
Rohit Visavalia 13cf912b2d tracing: Block comments should align the * on each line
Resolved Block comments use * on subsequent lines checkpatch warning.
Issue found by checkpatch.

Signed-off-by: Rohit Visavalia <rohit.visavalia@softnautics.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2018-03-27 09:51:23 +02:00
Davidlohr Bueso b720342849 sched/core: Update preempt_notifier_key to modern API
No changes in refcount semantics, use DEFINE_STATIC_KEY_FALSE()
for initialization and replace:

  static_key_slow_inc|dec()   =>   static_branch_inc|dec()
  static_key_false()          =>   static_branch_unlikely()

Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: akpm@linux-foundation.org
Link: http://lkml.kernel.org/r/20180326210929.5244-4-dave@stgolabs.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-27 07:51:45 +02:00
Joe Perches 447a5647c9 treewide: Align function definition open/close braces
Some functions definitions have either the initial open brace and/or
the closing brace outside of column 1.

Move those braces to column 1.

This allows various function analyzers like gnu complexity to work
properly for these modified functions.

Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Paul Moore <paul@paul-moore.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Takashi Iwai <tiwai@suse.de>
Acked-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Nicolin Chen <nicoleotsuka@gmail.com>
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2018-03-26 11:13:09 +02:00
Martin KaFai Lau 77d2e05abd bpf: Add bpf_verifier_vlog() and bpf_verifier_log_needed()
The BTF (BPF Type Format) verifier needs to reuse the current
BPF verifier log.  Hence, it requires the following changes:

(1) Expose log_write() in verifier.c for other users.
    Its name is renamed to bpf_verifier_vlog().

(2) The BTF verifier also needs to check
'log->level && log->ubuf && !bpf_verifier_log_full(log);'
independently outside of the current log_write().  It is
because the BTF verifier will do one-check before
making multiple calls to btf_verifier_vlog to log
the details of a type.

Hence, this check is also re-factored to a new function
bpf_verifier_log_needed().  Since it is re-factored,
we can check it before va_start() in the current
bpf_verifier_log_write() and verbose().

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Alexei Starovoitov <ast@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-03-26 09:58:17 +02:00
Martin KaFai Lau b9193c1b61 bpf: Rename bpf_verifer_log
bpf_verifer_log =>
bpf_verifier_log

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Alexei Starovoitov <ast@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-03-26 09:58:17 +02:00
Linus Torvalds 9fd64e8ac2 Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer fix from Ingo Molnar:
 "Make posix clock ID usage Spectre-safe"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  posix-timers: Protect posix clock array access against speculation
2018-03-25 07:34:50 -10:00
Linus Torvalds bf45bae961 Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fixes from Ingo Molnar:
 "Two sched debug output related fixes: a console output fix and
  formatting fixes"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/debug: Adjust newlines for better alignment
  sched/debug: Fix per-task line continuation for console output
2018-03-25 07:33:30 -10:00
Linus Torvalds eaf67993f5 Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Ingo Molnar:
 "Misc kernel side fixes.

  Generic:
   - cgroup events counting fix

  x86:
   - Intel PMU truncated-parameter fix

   - RDPMC fix

   - API naming fix/rename

   - uncore driver big-hardware PCI enumeration fix

   - uncore driver filter constraint fix"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/cgroup: Fix child event counting bug
  perf/x86/intel/uncore: Fix multi-domain PCI CHA enumeration bug on Skylake servers
  perf/x86/intel: Rename confusing 'freerunning PEBS' API and implementation to 'large PEBS'
  perf/x86/intel/uncore: Add missing filter constraint for SKX CHA event
  perf/x86/intel: Don't accidentally clear high bits in bdw_limit_period()
  perf/x86/intel: Disable userspace RDPMC usage for large PEBS
2018-03-25 07:27:32 -10:00
Linus Torvalds 6bacf66077 Merge branch 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking fixes from Ingo Molnar:
 "Two fixes: tighten up a jump-labels warning to not trigger on certain
  modules and fix confusing (and non-existent) mutex API documentation"

* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  jump_label: Disable jump labels in __exit code
  locking/mutex: Improve documentation
2018-03-25 07:18:31 -10:00
Ingo Molnar 7054e4e0b1 Merge branch 'perf/urgent' into perf/core, to pick up fixes
With the cherry-picked perf/urgent commit merged separately we can now
merge all the fixes without conflicts.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-24 09:21:47 +01:00
Linus Torvalds 99fec39e77 The documentation for kprobe events says that symbol offets can
take both a + and - sign to get to befor and after the symbol address.
 But in actuality, the code does not support the minus. This fixes
 that issue, and adds a few more selftests to kprobe events.
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 ovdZBMmiQBKjc727VgdRpkXWVA+sCoIhAzlkB5cSdDoYx5pHZi23qi5ZHjvlIIRz
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 BSMxInLOk5E+eechCkO/S9bugwlJYw2i7Oiq
 =SWSP
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Merge tag 'trace-v4.16-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull kprobe fixes from Steven Rostedt:
 "The documentation for kprobe events says that symbol offets can take
  both a + and - sign to get to befor and after the symbol address.

  But in actuality, the code does not support the minus. This fixes that
  issue, and adds a few more selftests to kprobe events"

* tag 'trace-v4.16-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  selftests: ftrace: Add a testcase for probepoint
  selftests: ftrace: Add a testcase for string type with kprobe_event
  selftests: ftrace: Add probe event argument syntax testcase
  tracing: probeevent: Fix to support minus offset from symbol
2018-03-23 15:34:18 -07:00
Claudio Scordino e97a90f706 sched/cpufreq: Rate limits for SCHED_DEADLINE
When the SCHED_DEADLINE scheduling class increases the CPU utilization, it
should not wait for the rate limit, otherwise it may miss some deadline.

Tests using rt-app on Exynos5422 with up to 10 SCHED_DEADLINE tasks have
shown reductions of even 10% of deadline misses with a negligible
increase of energy consumption (measured through Baylibre Cape).

Signed-off-by: Claudio Scordino <claudio@evidence.eu.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Joel Fernandes <joelaf@google.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: linux-pm@vger.kernel.org
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Morten Rasmussen <morten.rasmussen@arm.com>
Cc: Patrick Bellasi <patrick.bellasi@arm.com>
Cc: Todd Kjos <tkjos@android.com>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Link: https://lkml.kernel.org/r/1520937340-2755-1-git-send-email-claudio@evidence.eu.com
2018-03-23 22:48:22 +01:00
Jiri Olsa abe0884011 bpf: Remove struct bpf_verifier_env argument from print_bpf_insn
We use print_bpf_insn in user space (bpftool and soon perf),
so it'd be nice to keep it generic and strip it off the kernel
struct bpf_verifier_env argument.

This argument can be safely removed, because its users can
use the struct bpf_insn_cbs::private_data to pass it.

By changing the argument type  we can no longer have clean
'verbose' alias to 'bpf_verifier_log_write' in verifier.c.
Instead  we're adding the  'verbose' cb_print callback and
removing the alias.

This way we have new cb_print callback in place, and all
the 'verbose(env, ...) calls in verifier.c will cleanly
cast to 'verbose(void *, ...)' so no other change is
needed.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-03-23 17:38:57 +01:00
Masami Hiramatsu c5d343b6b7 tracing: probeevent: Fix to support minus offset from symbol
In Documentation/trace/kprobetrace.txt, it says

 @SYM[+|-offs] : Fetch memory at SYM +|- offs (SYM should be a data symbol)

However, the parser doesn't parse minus offset correctly, since
commit 2fba0c8867 ("tracing/kprobes: Fix probe offset to be
unsigned") drops minus ("-") offset support for kprobe probe
address usage.

This fixes the traceprobe_split_symbol_offset() to parse minus
offset again with checking the offset range, and add a minus
offset check in kprobe probe address usage.

Link: http://lkml.kernel.org/r/152129028983.31874.13419301530285775521.stgit@devbox

Cc: Ingo Molnar <mingo@redhat.com>
Cc: Tom Zanussi <tom.zanussi@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org
Fixes: 2fba0c8867 ("tracing/kprobes: Fix probe offset to be unsigned")
Acked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-03-23 12:02:37 -04:00
David S. Miller 03fe2debbb Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Fun set of conflict resolutions here...

For the mac80211 stuff, these were fortunately just parallel
adds.  Trivially resolved.

In drivers/net/phy/phy.c we had a bug fix in 'net' that moved the
function phy_disable_interrupts() earlier in the file, whilst in
'net-next' the phy_error() call from this function was removed.

In net/ipv4/xfrm4_policy.c, David Ahern's changes to remove the
'rt_table_id' member of rtable collided with a bug fix in 'net' that
added a new struct member "rt_mtu_locked" which needs to be copied
over here.

The mlxsw driver conflict consisted of net-next separating
the span code and definitions into separate files, whilst
a 'net' bug fix made some changes to that moved code.

The mlx5 infiniband conflict resolution was quite non-trivial,
the RDMA tree's merge commit was used as a guide here, and
here are their notes:

====================

    Due to bug fixes found by the syzkaller bot and taken into the for-rc
    branch after development for the 4.17 merge window had already started
    being taken into the for-next branch, there were fairly non-trivial
    merge issues that would need to be resolved between the for-rc branch
    and the for-next branch.  This merge resolves those conflicts and
    provides a unified base upon which ongoing development for 4.17 can
    be based.

    Conflicts:
            drivers/infiniband/hw/mlx5/main.c - Commit 42cea83f95
            (IB/mlx5: Fix cleanup order on unload) added to for-rc and
            commit b5ca15ad7e (IB/mlx5: Add proper representors support)
            add as part of the devel cycle both needed to modify the
            init/de-init functions used by mlx5.  To support the new
            representors, the new functions added by the cleanup patch
            needed to be made non-static, and the init/de-init list
            added by the representors patch needed to be modified to
            match the init/de-init list changes made by the cleanup
            patch.
    Updates:
            drivers/infiniband/hw/mlx5/mlx5_ib.h - Update function
            prototypes added by representors patch to reflect new function
            names as changed by cleanup patch
            drivers/infiniband/hw/mlx5/ib_rep.c - Update init/de-init
            stage list to match new order from cleanup patch
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-23 11:31:58 -04:00
Dan Carpenter 5e4cf2bf6d tracing: Fix a potential NULL dereference
We forgot to set the error code on this path so we return ERR_PTR(0)
which is NULL.  It results in a NULL dereference in the caller.

Link: http://lkml.kernel.org/r/20180323113735.GC28518@mwanda

Fixes: 100719dcef ("tracing: Add simple expression support to hist triggers")
Acked-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-03-23 11:15:20 -04:00
Tomeu Vizoso 47319f7186 printk: change message to pr_info
To allow userspace to prevent this message from appearing in the
console by changing the log priority.

This matches other informative messages that the power subsystem emits
when the system changes power states.

Link: http://lkml.kernel.org/r/20180322135833.16602-1-tomeu.vizoso@collabora.com
To: linux-kernel@vger.kernel.org
Cc: kernel@collabora.com
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
2018-03-23 15:41:59 +01:00
Linus Torvalds 8401c72c59 Merge branch 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm
Pull libnvdimm fixes from Dan Williams:
 "Two regression fixes, two bug fixes for older issues, two fixes for
  new functionality added this cycle that have userspace ABI concerns,
  and a small cleanup. These have appeared in a linux-next release and
  have a build success report from the 0day robot.

   * The 4.16 rework of altmap handling led to some configurations
     leaking page table allocations due to freeing from the altmap
     reservation rather than the page allocator.

     The impact without the fix is leaked memory and a WARN() message
     when tearing down libnvdimm namespaces. The rework also missed a
     place where error handling code needed to be removed that can lead
     to a crash if devm_memremap_pages() fails.

   * acpi_map_pxm_to_node() had a latent bug whereby it could
     misidentify the closest online node to a given proximity domain.

   * Block integrity handling was reworked several kernels back to allow
     calling add_disk() after setting up the integrity profile.

     The nd_btt and nd_blk drivers are just now catching up to fix
     automatic partition detection at driver load time.

   * The new peristence_domain attribute, a platform indicator of
     whether cpu caches are powerfail protected for example, is meant to
     be a single value enum and not a set of flags.

     This oversight was caught while reviewing new userspace code in
     libndctl to communicate the attribute.

     Fix this new enabling up so that we are not stuck with an unwanted
     userspace ABI"

* 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  libnvdimm, nfit: fix persistence domain reporting
  libnvdimm, region: hide persistence_domain when unknown
  acpi, numa: fix pxm to online numa node associations
  x86, memremap: fix altmap accounting at free
  libnvdimm: remove redundant assignment to pointer 'dev'
  libnvdimm, {btt, blk}: do integrity setup before add_disk()
  kernel/memremap: Remove stale devres_free() call
2018-03-22 18:37:49 -07:00
Linus Torvalds 394c73d396 Modules fix for v4.16-rc7
- Propagate error in modules_open() to avoid possible later NULL
   dereference if seq_open() had failed.
 
 Signed-off-by: Jessica Yu <jeyu@kernel.org>
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Merge tag 'modules-for-v4.16-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux

Pull modules fix from Jessica Yu:
 "Propagate error in modules_open() to avoid possible later NULL
  dereference if seq_open() had failed"

* tag 'modules-for-v4.16-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux:
  module: propagate error in modules_open()
2018-03-22 16:13:49 -07:00
James Morris 5893ed18a2 Linux 4.16-rc6
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Merge tag 'v4.16-rc6' into next-general

Merge to Linux 4.16-rc6 at the request of Jarkko, for his TPM updates.
2018-03-23 08:26:16 +11:00
Linus Torvalds c4f4d2f917 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Pull networking fixes from David Miller:

 1) Always validate XFRM esn replay attribute, from Florian Westphal.

 2) Fix RCU read lock imbalance in xfrm_get_tos(), from Xin Long.

 3) Don't try to get firmware dump if not loaded in iwlwifi, from Shaul
    Triebitz.

 4) Fix BPF helpers to deal with SCTP GSO SKBs properly, from Daniel
    Axtens.

 5) Fix some interrupt handling issues in e1000e driver, from Benjamin
    Poitier.

 6) Use strlcpy() in several ethtool get_strings methods, from Florian
    Fainelli.

 7) Fix rhlist dup insertion, from Paul Blakey.

 8) Fix SKB leak in netem packet scheduler, from Alexey Kodanev.

 9) Fix driver unload crash when link is up in smsc911x, from Jeremy
    Linton.

10) Purge out invalid socket types in l2tp_tunnel_create(), from Eric
    Dumazet.

11) Need to purge the write queue when TCP connections are aborted,
    otherwise userspace using MSG_ZEROCOPY can't close the fd. From
    Soheil Hassas Yeganeh.

12) Fix double free in error path of team driver, from Arkadi
    Sharshevsky.

13) Filter fixes for hv_netvsc driver, from Stephen Hemminger.

14) Fix non-linear packet access in ipv6 ndisc code, from Lorenzo
    Bianconi.

15) Properly filter out unsupported feature flags in macvlan driver,
    from Shannon Nelson.

16) Don't request loading the diag module for a protocol if the protocol
    itself is not even registered. From Xin Long.

17) If datagram connect fails in ipv6, make sure the socket state is
    consistent afterwards. From Paolo Abeni.

18) Use after free in qed driver, from Dan Carpenter.

19) If received ipv4 PMTU is less than the min pmtu, lock the mtu in the
    entry. From Sabrina Dubroca.

20) Fix sleep in atomic in tg3 driver, from Jonathan Toppins.

21) Fix vlan in vlan untagging in some situations, from Toshiaki Makita.

22) Fix double SKB free in genlmsg_mcast(). From Nicolas Dichtel.

23) Fix NULL derefs in error paths of tcf_*_init(), from Davide Caratti.

24) Unbalanced PM runtime calls in FEC driver, from Florian Fainelli.

25) Memory leak in gemini driver, from Igor Pylypiv.

26) IDR leaks in error paths of tcf_*_init() functions, from Davide
    Caratti.

27) Need to use GFP_ATOMIC in seg6_build_state(), from David Lebrun.

28) Missing dev_put() in error path of macsec_newlink(), from Dan
    Carpenter.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (201 commits)
  macsec: missing dev_put() on error in macsec_newlink()
  net: dsa: Fix functional dsa-loop dependency on FIXED_PHY
  hv_netvsc: common detach logic
  hv_netvsc: change GPAD teardown order on older versions
  hv_netvsc: use RCU to fix concurrent rx and queue changes
  hv_netvsc: disable NAPI before channel close
  net/ipv6: Handle onlink flag with multipath routes
  ppp: avoid loop in xmit recursion detection code
  ipv6: sr: fix NULL pointer dereference when setting encap source address
  ipv6: sr: fix scheduling in RCU when creating seg6 lwtunnel state
  net: aquantia: driver version bump
  net: aquantia: Implement pci shutdown callback
  net: aquantia: Allow live mac address changes
  net: aquantia: Add tx clean budget and valid budget handling logic
  net: aquantia: Change inefficient wait loop on fw data reads
  net: aquantia: Fix a regression with reset on old firmware
  net: aquantia: Fix hardware reset when SPI may rarely hangup
  s390/qeth: on channel error, reject further cmd requests
  s390/qeth: lock read device while queueing next buffer
  s390/qeth: when thread completes, wake up all waiters
  ...
2018-03-22 14:10:29 -07:00
Thomas Gleixner 19b558db12 posix-timers: Protect posix clock array access against speculation
The clockid argument of clockid_to_kclock() comes straight from user space
via various syscalls and is used as index into the posix_clocks array.

Protect it against spectre v1 array out of bounds speculation. Remove the
redundant check for !posix_clock[id] as this is another source for
speculation and does not provide any advantage over the return
posix_clock[id] path which returns NULL in that case anyway.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Cc: Rasmus Villemoes <rasmus.villemoes@prevas.dk>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: stable@vger.kernel.org
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Link: https://lkml.kernel.org/r/alpine.DEB.2.21.1802151718320.1296@nanos.tec.linutronix.de
2018-03-22 12:29:27 +01:00
Richard Guy Briggs 94b9d9b7a1 audit: remove path param from link denied function
In commit 45b578fe4c
("audit: link denied should not directly generate PATH record")
the need for the struct path *link parameter was removed.
Remove the now useless struct path argument.

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2018-03-21 11:17:41 -04:00
Alexey Dobriyan dd206bec9a pidns: simpler allocation of pid_* caches
Those pid_* caches are created on demand when a process advances to the new
level of pid namespace. Which means pointers are stable, write only and
thus can be packed into an array instead of spreading them over and using
lists(!) to find them.

Both first and subsequent clone/unshare(CLONE_NEWPID) become faster.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2018-03-21 09:40:17 -05:00
Chenbo Feng 0fa4fe85f4 bpf: skip unnecessary capability check
The current check statement in BPF syscall will do a capability check
for CAP_SYS_ADMIN before checking sysctl_unprivileged_bpf_disabled. This
code path will trigger unnecessary security hooks on capability checking
and cause false alarms on unprivileged process trying to get CAP_SYS_ADMIN
access. This can be resolved by simply switch the order of the statement
and CAP_SYS_ADMIN is not required anyway if unprivileged bpf syscall is
allowed.

Signed-off-by: Chenbo Feng <fengc@google.com>
Acked-by: Lorenzo Colitti <lorenzo@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-03-20 23:50:39 +01:00
Yonghong Song f005afede9 trace/bpf: remove helper bpf_perf_prog_read_value from tracepoint type programs
Commit 4bebdc7a85 ("bpf: add helper bpf_perf_prog_read_value")
added helper bpf_perf_prog_read_value so that perf_event type program
can read event counter and enabled/running time.
This commit, however, introduced a bug which allows this helper
for tracepoint type programs. This is incorrect as bpf_perf_prog_read_value
needs to access perf_event through its bpf_perf_event_data_kern type context,
which is not available for tracepoint type program.

This patch fixed the issue by separating bpf_func_proto between tracepoint
and perf_event type programs and removed bpf_perf_prog_read_value
from tracepoint func prototype.

Fixes: 4bebdc7a85 ("bpf: add helper bpf_perf_prog_read_value")
Reported-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-03-20 23:08:52 +01:00
Lai Jiangshan f75da8a8a9 workqueue: remove the comment about the old manager_arb mutex
The manager_arb mutex doesn't exist any more.

Signed-off-by: Lai Jiangshan <jiangshanlai@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2018-03-20 13:01:45 -07:00
Lai Jiangshan 5826cc8f5a workqueue: fix the comments of nr_idle
Since the worker rebinding behavior was refactored, there is
no idle worker off the idle_list now. The comment is outdated
and can be just removed.

It also groups nr_workers and nr_idle together.

Signed-off-by: Lai Jiangshan <jiangshanlai@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2018-03-20 13:01:36 -07:00
Thomas Gleixner f3f59fbc54 genirq: Remove license boilerplate/references
Now that SPDX identifiers are in place, remove the boilerplate or
references.

The change in timings.c has been acked by the author.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Link: https://lkml.kernel.org/r/20180314212030.668321222@linutronix.de
2018-03-20 14:23:28 +01:00
Thomas Gleixner 52a65ff560 genirq: Add missing SPDX identifiers
Add SPDX identifiers to files

 - which contain an explicit license boiler plate or reference

 - which do not contain a license reference and were not updated in the
   initial SPDX conversion because the license was deduced by the scanners
   via EXPORT_SYMBOL_GPL as GPL2.0 only.

[ tglx: Moved adding identifiers from the patch which removes the
  	references/boilerplate ]

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Link: https://lkml.kernel.org/r/20180314212030.668321222@linutronix.de
2018-03-20 14:23:28 +01:00
Thomas Gleixner 90cafdd521 genirq/matrix: Cleanup SPDX identifier
Use the proper SPDX-Identifier format.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Link: https://lkml.kernel.org/r/20180314212030.492674761@linutronix.de
2018-03-20 14:23:28 +01:00
Thomas Gleixner 99bfce5db9 genirq: Cleanup top of file comments
Remove pointless references to the file name itself and condense the
information so it wastes less space.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Link: https://lkml.kernel.org/r/20180314212030.412095827@linutronix.de
2018-03-20 14:23:27 +01:00
Joe Lawrence e9ca267096 sched/debug: Adjust newlines for better alignment
Scheduler debug stats include newlines that display out of alignment
when prefixed by timestamps.  For example, the dmesg utility:

  % echo t > /proc/sysrq-trigger
  % dmesg
  ...
  [   83.124251]
  runnable tasks:
   S           task   PID         tree-key  switches  prio     wait-time
  sum-exec        sum-sleep
  -----------------------------------------------------------------------------------------------------------

At the same time, some syslog utilities (like rsyslog by default) don't
like the additional newlines control characters, saving lines like this
to /var/log/messages:

  Mar 16 16:02:29 localhost kernel: #012runnable tasks:#012 S           task   PID         tree-key ...
                                    ^^^^               ^^^^
Clean these up by moving newline characters to their own SEQ_printf
invocation.  This leaves the /proc/sched_debug unchanged, but brings the
entire output into alignment when prefixed:

  % echo t > /proc/sysrq-trigger
  % dmesg
  ...
  [   62.410368] runnable tasks:
  [   62.410368]  S           task   PID         tree-key  switches  prio     wait-time             sum-exec        sum-sleep
  [   62.410369] -----------------------------------------------------------------------------------------------------------
  [   62.410369]  I  kworker/u12:0     5      1932.215593       332   120         0.000000         3.621252         0.000000 0 0 /

and no escaped control characters from rsyslog in /var/log/messages:

  Mar 16 16:15:06 localhost kernel: runnable tasks:
  Mar 16 16:15:06 localhost kernel: S           task   PID         tree-key  ...

Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1521484555-8620-3-git-send-email-joe.lawrence@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-20 09:30:09 +01:00
Joe Lawrence a8c024cd9b sched/debug: Fix per-task line continuation for console output
When the SEQ_printf() macro prints to the console, it runs a simple
printk() without KERN_CONT "continued" line printing.  The result of
this is oddly wrapped task info, for example:

  % echo t > /proc/sysrq-trigger
  % dmesg
  ...
  runnable tasks:
  ...
  [   29.608611]  I
  [   29.608613]       rcu_sched     8      3252.013846      4087   120
  [   29.608614]         0.000000        29.090111         0.000000
  [   29.608615]  0 0
  [   29.608616]  /

Modify SEQ_printf to use pr_cont() for expected one-line results:

  % echo t > /proc/sysrq-trigger
  % dmesg
  ...
  runnable tasks:
  ...
  [  106.716329]  S        cpuhp/5    37      2006.315026        14   120         0.000000         0.496893         0.000000 0 0 /

Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1521484555-8620-2-git-send-email-joe.lawrence@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-20 09:30:09 +01:00
Luis R. Rodriguez ceb1813224 firmware: enable run time change of forcing fallback loader
Currently one requires to test four kernel configurations to test the
firmware API completely:

0)
  CONFIG_FW_LOADER=y

1)
  o CONFIG_FW_LOADER=y
  o CONFIG_FW_LOADER_USER_HELPER=y

2)
  o CONFIG_FW_LOADER=y
  o CONFIG_FW_LOADER_USER_HELPER=y
  o CONFIG_FW_LOADER_USER_HELPER_FALLBACK=y

3) When CONFIG_FW_LOADER=m the built-in stuff is disabled, we have
   no current tests for this.

We can reduce the requirements to three kernel configurations by making
fw_config.force_sysfs_fallback a proc knob we flip on off. For kernels that
disable CONFIG_IKCONFIG_PROC this can also enable one to inspect if
CONFIG_FW_LOADER_USER_HELPER_FALLBACK was enabled at build time by checking
the proc value at boot time.

Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-20 09:28:47 +01:00
Song Liu c917e0f259 perf/cgroup: Fix child event counting bug
When a perf_event is attached to parent cgroup, it should count events
for all children cgroups:

   parent_group   <---- perf_event
     \
      - child_group  <---- process(es)

However, in our tests, we found this perf_event cannot report reliable
results. Here is an example case:

  # create cgroups
  mkdir -p /sys/fs/cgroup/p/c
  # start perf for parent group
  perf stat -e instructions -G "p"

  # on another console, run test process in child cgroup:
  stressapptest -s 2 -M 1000 & echo $! > /sys/fs/cgroup/p/c/cgroup.procs

  # after the test process is done, stop perf in the first console shows

       <not counted>      instructions              p

The instruction should not be "not counted" as the process runs in the
child cgroup.

We found this is because perf_event->cgrp and cpuctx->cgrp are not
identical, thus perf_event->cgrp are not updated properly.

This patch fixes this by updating perf_cgroup properly for ancestor
cgroup(s).

Reported-by: Ephraim Park <ephiepark@fb.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <jolsa@redhat.com>
Cc: <kernel-team@fb.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Link: http://lkml.kernel.org/r/20180312165943.1057894-1-songliubraving@fb.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-20 08:58:47 +01:00
Josh Poimboeuf 578ae447e7 jump_label: Disable jump labels in __exit code
With the following commit:

  3335224470 ("jump_label: Explicitly disable jump labels in __init code")

... we explicitly disabled jump labels in __init code, so they could be
detected and not warned about in the following commit:

  dc1dd184c2 ("jump_label: Warn on failed jump_label patching attempt")

In-kernel __exit code has the same issue.  It's never used, so it's
freed along with the rest of initmem.  But jump label entries in __exit
code aren't explicitly disabled, so we get the following warning when
enabling pr_debug() in __exit code:

  can't patch jump_label at dmi_sysfs_exit+0x0/0x2d
  WARNING: CPU: 0 PID: 22572 at kernel/jump_label.c:376 __jump_label_update+0x9d/0xb0

Fix the warning by disabling all jump labels in initmem (which includes
both __init and __exit code).

Reported-and-tested-by: Li Wang <liwang@redhat.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Jason Baron <jbaron@akamai.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: dc1dd184c2 ("jump_label: Warn on failed jump_label patching attempt")
Link: http://lkml.kernel.org/r/7121e6e595374f06616c505b6e690e275c0054d1.1521483452.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-20 08:57:17 +01:00
Uwe Kleine König 83ac4ca943 genirq: Pass desc to __irq_free instead of irq number
Given that irq_to_desc() is a radix_tree_lookup and the reverse
operation is only a pointer dereference and that all callers of
__free_irq already have the desc, pass the desc instead of the irq
number.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: kernel@pengutronix.de
Link: https://lkml.kernel.org/r/20180319105202.9794-1-u.kleine-koenig@pengutronix.de
2018-03-20 08:52:44 +01:00
Peter Zijlstra b3fc5c9bb3 sched/wait: Improve __var_waitqueue() code generation
Since we fixed hash_64() to not suck there is no need to play games to
attempt to improve the hash value on 64-bit.

Also, since we don't use the bit value for the variables, use hash_ptr()
directly.

No change in functionality.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: George Spelvin <linux@sciencehorizons.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-20 08:23:25 +01:00
Peter Zijlstra 9b8cce52c4 sched/wait: Remove the wait_on_atomic_t() API
There are no users left (everyone got converted to wait_var_event()), remove it.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-20 08:23:24 +01:00
Peter Zijlstra 6b2bb7265f sched/wait: Introduce wait_var_event()
As a replacement for the wait_on_atomic_t() API provide the
wait_var_event() API.

The wait_var_event() API is based on the very same hashed-waitqueue
idea, but doesn't care about the type (atomic_t) or the specific
condition (atomic_read() == 0). IOW. it's much more widely
applicable/flexible.

It shares all the benefits/disadvantages of a hashed-waitqueue
approach with the existing wait_on_atomic_t/wait_on_bit() APIs.

The API is modeled after the existing wait_event() API, but instead of
taking a wait_queue_head, it takes an address. This addresses is
hashed to obtain a wait_queue_head from the bit_wait_table.

Similar to the wait_event() API, it takes a condition expression as
second argument and will wait until this expression becomes true.

The following are (mostly) identical replacements:

	wait_on_atomic_t(&my_atomic, atomic_t_wait, TASK_UNINTERRUPTIBLE);
	wake_up_atomic_t(&my_atomic);

	wait_var_event(&my_atomic, !atomic_read(&my_atomic));
	wake_up_var(&my_atomic);

The only difference is that wake_up_var() is an unconditional wakeup
and doesn't check the previously hard-coded (atomic_read() == 0)
condition here. This is of little concequence, since most callers are
already conditional on atomic_dec_and_test() and the ones that are
not, are trivial to make so.

Tested-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-20 08:23:17 +01:00
Patrick Bellasi d519329f72 sched/fair: Update util_est only on util_avg updates
The estimated utilization of a task is currently updated every time the
task is dequeued. However, to keep overheads under control, PELT signals
are effectively updated at maximum once every 1ms.

Thus, for really short running tasks, it can happen that their util_avg
value has not been updates since their last enqueue.  If such tasks are
also frequently running tasks (e.g. the kind of workload generated by
hackbench) it can also happen that their util_avg is updated only every
few activations.

This means that updating util_est at every dequeue potentially introduces
not necessary overheads and it's also conceptually wrong if the util_avg
signal has never been updated during a task activation.

Let's introduce a throttling mechanism on task's util_est updates
to sync them with util_avg updates. To make the solution memory
efficient, both in terms of space and load/store operations, we encode a
synchronization flag into the LSB of util_est.enqueued.
This makes util_est an even values only metric, which is still
considered good enough for its purpose.
The synchronization bit is (re)set by __update_load_avg_se() once the
PELT signal of a task has been updated during its last activation.

Such a throttling mechanism allows to keep under control util_est
overheads in the wakeup hot path, thus making it a suitable mechanism
which can be enabled also on high-intensity workload systems.
Thus, this now switches on by default the estimation utilization
scheduler feature.

Suggested-by: Chris Redpath <chris.redpath@arm.com>
Signed-off-by: Patrick Bellasi <patrick.bellasi@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Joel Fernandes <joelaf@google.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Morten Rasmussen <morten.rasmussen@arm.com>
Cc: Paul Turner <pjt@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J . Wysocki <rafael.j.wysocki@intel.com>
Cc: Steve Muckle <smuckle@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Todd Kjos <tkjos@android.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Link: http://lkml.kernel.org/r/20180309095245.11071-5-patrick.bellasi@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-20 08:11:09 +01:00
Patrick Bellasi a07630b8b2 sched/cpufreq/schedutil: Use util_est for OPP selection
When schedutil looks at the CPU utilization, the current PELT value for
that CPU is returned straight away. In certain scenarios this can have
undesired side effects and delays on frequency selection.

For example, since the task utilization is decayed at wakeup time, a
long sleeping big task newly enqueued does not add immediately a
significant contribution to the target CPU. This introduces some latency
before schedutil will be able to detect the best frequency required by
that task.

Moreover, the PELT signal build-up time is a function of the current
frequency, because of the scale invariant load tracking support. Thus,
starting from a lower frequency, the utilization build-up time will
increase even more and further delays the selection of the actual
frequency which better serves the task requirements.

In order to reduce these kind of latencies, we integrate the usage
of the CPU's estimated utilization in the sugov_get_util function.

This allows to properly consider the expected utilization of a CPU which,
for example, has just got a big task running after a long sleep period.
Ultimately this allows to select the best frequency to run a task
right after its wake-up.

Signed-off-by: Patrick Bellasi <patrick.bellasi@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Joel Fernandes <joelaf@google.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Morten Rasmussen <morten.rasmussen@arm.com>
Cc: Paul Turner <pjt@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steve Muckle <smuckle@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Todd Kjos <tkjos@android.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Link: http://lkml.kernel.org/r/20180309095245.11071-4-patrick.bellasi@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-20 08:11:08 +01:00
Patrick Bellasi f9be3e5961 sched/fair: Use util_est in LB and WU paths
When the scheduler looks at the CPU utilization, the current PELT value
for a CPU is returned straight away. In certain scenarios this can have
undesired side effects on task placement.

For example, since the task utilization is decayed at wakeup time, when
a long sleeping big task is enqueued it does not add immediately a
significant contribution to the target CPU.
As a result we generate a race condition where other tasks can be placed
on the same CPU while it is still considered relatively empty.

In order to reduce this kind of race conditions, this patch introduces the
required support to integrate the usage of the CPU's estimated utilization
in the wakeup path, via cpu_util_wake(), as well as in the load-balance
path, via cpu_util() which is used by update_sg_lb_stats().

The estimated utilization of a CPU is defined to be the maximum between
its PELT's utilization and the sum of the estimated utilization (at
previous dequeue time) of all the tasks currently RUNNABLE on that CPU.
This allows to properly represent the spare capacity of a CPU which, for
example, has just got a big task running since a long sleep period.

Signed-off-by: Patrick Bellasi <patrick.bellasi@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Joel Fernandes <joelaf@google.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Morten Rasmussen <morten.rasmussen@arm.com>
Cc: Paul Turner <pjt@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J . Wysocki <rafael.j.wysocki@intel.com>
Cc: Steve Muckle <smuckle@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Todd Kjos <tkjos@android.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Link: http://lkml.kernel.org/r/20180309095245.11071-3-patrick.bellasi@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-20 08:11:07 +01:00
Patrick Bellasi 7f65ea42eb sched/fair: Add util_est on top of PELT
The util_avg signal computed by PELT is too variable for some use-cases.
For example, a big task waking up after a long sleep period will have its
utilization almost completely decayed. This introduces some latency before
schedutil will be able to pick the best frequency to run a task.

The same issue can affect task placement. Indeed, since the task
utilization is already decayed at wakeup, when the task is enqueued in a
CPU, this can result in a CPU running a big task as being temporarily
represented as being almost empty. This leads to a race condition where
other tasks can be potentially allocated on a CPU which just started to run
a big task which slept for a relatively long period.

Moreover, the PELT utilization of a task can be updated every [ms], thus
making it a continuously changing value for certain longer running
tasks. This means that the instantaneous PELT utilization of a RUNNING
task is not really meaningful to properly support scheduler decisions.

For all these reasons, a more stable signal can do a better job of
representing the expected/estimated utilization of a task/cfs_rq.
Such a signal can be easily created on top of PELT by still using it as
an estimator which produces values to be aggregated on meaningful
events.

This patch adds a simple implementation of util_est, a new signal built on
top of PELT's util_avg where:

    util_est(task) = max(task::util_avg, f(task::util_avg@dequeue))

This allows to remember how big a task has been reported by PELT in its
previous activations via f(task::util_avg@dequeue), which is the new
_task_util_est(struct task_struct*) function added by this patch.

If a task should change its behavior and it runs longer in a new
activation, after a certain time its util_est will just track the
original PELT signal (i.e. task::util_avg).

The estimated utilization of cfs_rq is defined only for root ones.
That's because the only sensible consumer of this signal are the
scheduler and schedutil when looking for the overall CPU utilization
due to FAIR tasks.

For this reason, the estimated utilization of a root cfs_rq is simply
defined as:

    util_est(cfs_rq) = max(cfs_rq::util_avg, cfs_rq::util_est::enqueued)

where:

    cfs_rq::util_est::enqueued = sum(_task_util_est(task))
                                 for each RUNNABLE task on that root cfs_rq

It's worth noting that the estimated utilization is tracked only for
objects of interests, specifically:

 - Tasks: to better support tasks placement decisions
 - root cfs_rqs: to better support both tasks placement decisions as
                 well as frequencies selection

Signed-off-by: Patrick Bellasi <patrick.bellasi@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Joel Fernandes <joelaf@google.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Morten Rasmussen <morten.rasmussen@arm.com>
Cc: Paul Turner <pjt@google.com>
Cc: Rafael J . Wysocki <rafael.j.wysocki@intel.com>
Cc: Steve Muckle <smuckle@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Todd Kjos <tkjos@android.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Link: http://lkml.kernel.org/r/20180309095245.11071-2-patrick.bellasi@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-20 08:11:06 +01:00
Ingo Molnar 10c18c44a6 Merge branch 'linus' into sched/core, to pick up fixes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-20 08:08:02 +01:00
Matthew Wilcox 45dbac0e28 locking/mutex: Improve documentation
On Wed, Mar 14, 2018 at 01:56:31PM -0700, Andrew Morton wrote:

> My memory is weak and our documentation is awful.  What does
> mutex_lock_killable() actually do and how does it differ from
> mutex_lock_interruptible()?

Add kernel-doc for mutex_lock_killable() and mutex_lock_io().  Reword the
kernel-doc for mutex_lock_interruptible().

Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: cl@linux.com
Cc: tj@kernel.org
Link: http://lkml.kernel.org/r/20180315115812.GA9949@bombadil.infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-20 08:07:41 +01:00
Marc-André Lureau 43d4cb47f6 crash: export paddr_vmcoreinfo_note()
The following patch is going to use the symbol from the fw_cfg module,
to call the function and write the note location details in the
vmcoreinfo entry, so qemu can produce dumps with the vmcoreinfo note.

CC: Andrew Morton <akpm@linux-foundation.org>
CC: Hari Bathini <hbathini@linux.vnet.ibm.com>
CC: Tony Luck <tony.luck@intel.com>
CC: Vivek Goyal <vgoyal@redhat.com>
Acked-by: Baoquan He <bhe@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Acked-by: Gabriel Somlo <somlo@cmu.edu>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2018-03-20 03:17:41 +02:00
Linus Torvalds 1b5f3ba415 Merge branch 'for-4.16-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup fixes from Tejun Heo:
 "Two commits to fix the following subtle cgroup2 behavior bugs:

   - cpu.max was rejecting config when it shouldn't

   - thread mode enable was allowed when it shouldn't"

* 'for-4.16-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cgroup: fix rule checking for threaded mode switching
  sched, cgroup: Don't reject lower cpu.max on ancestors
2018-03-19 15:39:02 -07:00
Linus Torvalds c6256ca9c0 Merge branch 'for-4.16-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
Pull workqueue fixes from Tejun Heo:
 "Two low-impact workqueue commits.

  One fixes workqueue creation error path and the other removes the
  unused cancel_work()"

* 'for-4.16-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  workqueue: remove unused cancel_work()
  workqueue: use put_device() instead of kfree()
2018-03-19 15:13:04 -07:00
John Fastabend 4f738adba3 bpf: create tcp_bpf_ulp allowing BPF to monitor socket TX/RX data
This implements a BPF ULP layer to allow policy enforcement and
monitoring at the socket layer. In order to support this a new
program type BPF_PROG_TYPE_SK_MSG is used to run the policy at
the sendmsg/sendpage hook. To attach the policy to sockets a
sockmap is used with a new program attach type BPF_SK_MSG_VERDICT.

Similar to previous sockmap usages when a sock is added to a
sockmap, via a map update, if the map contains a BPF_SK_MSG_VERDICT
program type attached then the BPF ULP layer is created on the
socket and the attached BPF_PROG_TYPE_SK_MSG program is run for
every msg in sendmsg case and page/offset in sendpage case.

BPF_PROG_TYPE_SK_MSG Semantics/API:

BPF_PROG_TYPE_SK_MSG supports only two return codes SK_PASS and
SK_DROP. Returning SK_DROP free's the copied data in the sendmsg
case and in the sendpage case leaves the data untouched. Both cases
return -EACESS to the user. Returning SK_PASS will allow the msg to
be sent.

In the sendmsg case data is copied into kernel space buffers before
running the BPF program. The kernel space buffers are stored in a
scatterlist object where each element is a kernel memory buffer.
Some effort is made to coalesce data from the sendmsg call here.
For example a sendmsg call with many one byte iov entries will
likely be pushed into a single entry. The BPF program is run with
data pointers (start/end) pointing to the first sg element.

In the sendpage case data is not copied. We opt not to copy the
data by default here, because the BPF infrastructure does not
know what bytes will be needed nor when they will be needed. So
copying all bytes may be wasteful. Because of this the initial
start/end data pointers are (0,0). Meaning no data can be read or
written. This avoids reading data that may be modified by the
user. A new helper is added later in this series if reading and
writing the data is needed. The helper call will do a copy by
default so that the page is exclusively owned by the BPF call.

The verdict from the BPF_PROG_TYPE_SK_MSG applies to the entire msg
in the sendmsg() case and the entire page/offset in the sendpage case.
This avoids ambiguity on how to handle mixed return codes in the
sendmsg case. Again a helper is added later in the series if
a verdict needs to apply to multiple system calls and/or only
a subpart of the currently being processed message.

The helper msg_redirect_map() can be used to select the socket to
send the data on. This is used similar to existing redirect use
cases. This allows policy to redirect msgs.

Pseudo code simple example:

The basic logic to attach a program to a socket is as follows,

  // load the programs
  bpf_prog_load(SOCKMAP_TCP_MSG_PROG, BPF_PROG_TYPE_SK_MSG,
		&obj, &msg_prog);

  // lookup the sockmap
  bpf_map_msg = bpf_object__find_map_by_name(obj, "my_sock_map");

  // get fd for sockmap
  map_fd_msg = bpf_map__fd(bpf_map_msg);

  // attach program to sockmap
  bpf_prog_attach(msg_prog, map_fd_msg, BPF_SK_MSG_VERDICT, 0);

Adding sockets to the map is done in the normal way,

  // Add a socket 'fd' to sockmap at location 'i'
  bpf_map_update_elem(map_fd_msg, &i, fd, BPF_ANY);

After the above any socket attached to "my_sock_map", in this case
'fd', will run the BPF msg verdict program (msg_prog) on every
sendmsg and sendpage system call.

For a complete example see BPF selftests or sockmap samples.

Implementation notes:

It seemed the simplest, to me at least, to use a refcnt to ensure
psock is not lost across the sendmsg copy into the sg, the bpf program
running on the data in sg_data, and the final pass to the TCP stack.
Some performance testing may show a better method to do this and avoid
the refcnt cost, but for now use the simpler method.

Another item that will come after basic support is in place is
supporting MSG_MORE flag. At the moment we call sendpages even if
the MSG_MORE flag is set. An enhancement would be to collect the
pages into a larger scatterlist and pass down the stack. Notice that
bpf_tcp_sendmsg() could support this with some additional state saved
across sendmsg calls. I built the code to support this without having
to do refactoring work. Other features TBD include ZEROCOPY and the
TCP_RECV_QUEUE/TCP_NO_QUEUE support. This will follow initial series
shortly.

Future work could improve size limits on the scatterlist rings used
here. Currently, we use MAX_SKB_FRAGS simply because this was being
used already in the TLS case. Future work could extend the kernel sk
APIs to tune this depending on workload. This is a trade-off
between memory usage and throughput performance.

Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-03-19 21:14:38 +01:00
John Fastabend ffa3566001 sockmap: convert refcnt to an atomic refcnt
The sockmap refcnt up until now has been wrapped in the
sk_callback_lock(). So its not actually needed any locking of its
own. The counter itself tracks the lifetime of the psock object.
Sockets in a sockmap have a lifetime that is independent of the
map they are part of. This is possible because a single socket may
be in multiple maps. When this happens we can only release the
psock data associated with the socket when the refcnt reaches
zero. There are three possible delete sock reference decrement
paths first through the normal sockmap process, the user deletes
the socket from the map. Second the map is removed and all sockets
in the map are removed, delete path is similar to case 1. The third
case is an asyncronous socket event such as a closing the socket. The
last case handles removing sockets that are no longer available.
For completeness, although inc does not pose any problems in this
patch series, the inc case only happens when a psock is added to a
map.

Next we plan to add another socket prog type to handle policy and
monitoring on the TX path. When we do this however we will need to
keep a reference count open across the sendmsg/sendpage call and
holding the sk_callback_lock() here (on every send) seems less than
ideal, also it may sleep in cases where we hit memory pressure.
Instead of dealing with these issues in some clever way simply make
the reference counting a refcnt_t type and do proper atomic ops.

Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-03-19 21:14:38 +01:00
Ingo Molnar 134933e557 Linux 4.16-rc6
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Merge tag 'v4.16-rc6' into perf/core, to pick up fixes

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-19 20:37:35 +01:00
Tejun Heo 8f36aaec9c cgroup: Use rcu_work instead of explicit rcu and work item
Workqueue now has rcu_work.  Use it instead of open-coding rcu -> work
item bouncing.

Signed-off-by: Tejun Heo <tj@kernel.org>
2018-03-19 10:12:03 -07:00
Tejun Heo 05f0fe6b74 RCU, workqueue: Implement rcu_work
There are cases where RCU callback needs to be bounced to a sleepable
context.  This is currently done by the RCU callback queueing a work
item, which can be cumbersome to write and confusing to read.

This patch introduces rcu_work, a workqueue work variant which gets
executed after a RCU grace period, and converts the open coded
bouncing in fs/aio and kernel/cgroup.

v3: Dropped queue_rcu_work_on().  Documented rcu grace period behavior
    after queue_rcu_work().

v2: Use rcu_barrier() instead of synchronize_rcu() to wait for
    completion of previously queued rcu callback as per Paul.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
2018-03-19 10:12:03 -07:00
Arnd Bergmann a84d116916 y2038: Introduce struct __kernel_old_timeval
Dealing with 'struct timeval' users in the y2038 series is a bit tricky:

We have two definitions of timeval that are visible to user space,
one comes from glibc (or some other C library), the other comes from
linux/time.h. The kernel copy is what we want to be used for a number of
structures defined by the kernel itself, e.g. elf_prstatus (used it core
dumps), sysinfo and rusage (used in system calls).  These generally tend
to be used for passing time intervals rather than absolute (epoch-based)
times, so they do not suffer from the y2038 overflow. Some of them
could be changed to use 64-bit timestamps by creating new system calls,
others like the core files cannot easily be changed.

An application using these interfaces likely also uses gettimeofday()
or other interfaces that use absolute times, and pass 'struct timeval'
pointers directly into kernel interfaces, so glibc must redefine their
timeval based on a 64-bit time_t when they introduce their y2038-safe
interfaces.

The only reasonable way forward I see is to remove the 'timeval'
definion from the kernel's uapi headers, and change the interfaces that
we do not want to (or cannot) duplicate for 64-bit times to use a new
__kernel_old_timeval definition instead. This type should be avoided
for all new interfaces (those can use 64-bit nanoseconds, or the 64-bit
version of timespec instead), and should be used with great care when
converting existing interfaces from timeval, to be sure they don't suffer
from the y2038 overflow, and only with consensus for the particular user
that using __kernel_old_timeval is better than moving to a 64-bit based
interface. The structure name is intentionally chosen to not conflict
with user space types, and to be ugly enough to discourage its use.

Note that ioctl based interfaces that pass a bare 'timeval' pointer
cannot change to '__kernel_old_timeval' because the user space source
code refers to 'timeval' instead, and we don't want to modify the user
space sources if possible. However, any application that relies on a
structure to contain an embedded 'timeval' (e.g. by passing a pointer
to the member into a function call that expects a timeval pointer) is
broken when that structure gets converted to __kernel_old_timeval. I
don't see any way around that, and we have to rely on the compiler to
produce a warning or compile failure that will alert users when they
recompile their sources against a new libc.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Stephen Boyd <sboyd@kernel.org>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Link: https://lkml.kernel.org/r/20180315161739.576085-1-arnd@arndb.de
2018-03-19 15:23:03 +01:00
Linus Torvalds 9e1909b9da Merge branch 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86/pti updates from Thomas Gleixner:
 "Another set of melted spectrum updates:

   - Iron out the last late microcode loading issues by actually
     checking whether new microcode is present and preventing the CPU
     synchronization to run into a timeout induced hang.

   - Remove Skylake C2 from the microcode blacklist according to the
     latest Intel documentation

   - Fix the VM86 POPF emulation which traps if VIP is set, but VIF is
     not. Enhance the selftests to catch that kind of issue

   - Annotate indirect calls/jumps for objtool on 32bit. This is not a
     functional issue, but for consistency sake its the right thing to
     do.

   - Fix a jump label build warning observed on SPARC64 which uses 32bit
     storage for the code location which is casted to 64 bit pointer w/o
     extending it to 64bit first.

   - Add two new cpufeature bits. Not really an urgent issue, but
     provides them for both x86 and x86/kvm work. No impact on the
     current kernel"

* 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/microcode: Fix CPU synchronization routine
  x86/microcode: Attempt late loading only when new microcode is present
  x86/speculation: Remove Skylake C2 from Speculation Control microcode blacklist
  jump_label: Fix sparc64 warning
  x86/speculation, objtool: Annotate indirect calls/jumps for objtool on 32-bit kernels
  x86/vm86/32: Fix POPF emulation
  selftests/x86/entry_from_vm86: Add test cases for POPF
  selftests/x86/entry_from_vm86: Exit with 1 if we fail
  x86/cpufeatures: Add Intel PCONFIG cpufeature
  x86/cpufeatures: Add Intel Total Memory Encryption cpufeature
2018-03-18 12:03:15 -07:00
Mark Rutland 24868367cd perf/core: Clear sibling list of detached events
When perf_group_dettach() is called on a group leader, it updates each
sibling's group_leader field to point to that sibling, effectively
upgrading each siblnig to a group leader. After perf_group_detach has
completed, the caller may free the leader event.

We only remove siblings from the group leader's sibling_list when the
leader has a non-empty group_node. This was fine prior to commit:

  8343aae661 ("perf/core: Remove perf_event::group_entry")

... as the sibling's sibling_list would be empty. However, now that we
use the sibling_list field as both the list head and the list entry,
this leaves each sibling with a non-empty sibling list, including the
stale leader event.

If perf_group_detach() is subsequently called on a sibling, it will
appear to be a group leader, and we'll walk the sibling_list,
potentially dereferencing these stale events. In 0day testing, this has
been observed to result in kernel panics.

Let's avoid this by always removing siblings from the sibling list when
we promote them to leaders.

Fixes: 8343aae661 ("perf/core: Remove perf_event::group_entry")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: vincent.weaver@maine.edu
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: torvalds@linux-foundation.org
Cc: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: valery.cherepennikov@intel.com
Cc: linux-tip-commits@vger.kernel.org
Cc: eranian@google.com
Cc: acme@redhat.com
Cc: alexander.shishkin@linux.intel.com
Cc: davidcc@google.com
Cc: kan.liang@intel.com
Cc: Dmitry.Prohorov@intel.com
Cc: Jiri Olsa <jolsa@redhat.com>
Link: https://lkml.kernel.org/r/20180316131741.3svgr64yibc6vsid@lakrids.cambridge.arm.com
2018-03-16 20:44:32 +01:00
Peter Zijlstra edb39592a5 perf: Fix sibling iteration
Mark noticed that the change to sibling_list changed some iteration
semantics; because previously we used group_list as list entry,
sibling events would always have an empty sibling_list.

But because we now use sibling_list for both list head and list entry,
siblings will report as having siblings.

Fix this with a custom for_each_sibling_event() iterator.

Fixes: 8343aae661 ("perf/core: Remove perf_event::group_entry")
Reported-by: Mark Rutland <mark.rutland@arm.com>
Suggested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: vincent.weaver@maine.edu
Cc: alexander.shishkin@linux.intel.com
Cc: torvalds@linux-foundation.org
Cc: alexey.budankov@linux.intel.com
Cc: valery.cherepennikov@intel.com
Cc: eranian@google.com
Cc: acme@redhat.com
Cc: linux-tip-commits@vger.kernel.org
Cc: davidcc@google.com
Cc: kan.liang@intel.com
Cc: Dmitry.Prohorov@intel.com
Cc: jolsa@redhat.com
Link: https://lkml.kernel.org/r/20180315170129.GX4043@hirez.programming.kicks-ass.net
2018-03-16 20:44:12 +01:00
Arnd Bergmann 1a8429132e mm: remove blackfin MPU support
The CONFIG_MPU option was only defined on blackfin, and that architecture
is now being removed, so the respective code can be simplified.

A lot of other microcontrollers have an MPU, but I suspect that if we
want to bring that support back, we'd do it differently anyway.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2018-03-16 10:56:10 +01:00
Arnd Bergmann fcb3029a8d cpu/hotplug: Fix unused function warning
The cpuhp_is_ap_state() function is no longer called outside of the
CONFIG_SMP #ifdef section, causing a harmless warning:

kernel/cpu.c:129:13: error: 'cpuhp_is_ap_state' defined but not used [-Werror=unused-function]

This moves the function into the #ifdef to get a clean build again.

Fixes: 17a2f1ced0 ("cpu/hotplug: Merge cpuhp_bp_states and cpuhp_ap_states")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Link: https://lkml.kernel.org/r/20180315153829.3819606-1-arnd@arndb.de
2018-03-15 20:34:40 +01:00
Dave Young e36df28f53 printk: move dump stack related code to lib/dump_stack.c
dump_stack related stuff should belong to lib/dump_stack.c thus move them
there. Also conditionally compile lib/dump_stack.c since dump_stack code
does not make sense if printk is disabled.

Link: http://lkml.kernel.org/r/20180213072834.GA24784@dhcp-128-65.nay.redhat.com
To: Steven Rostedt <rostedt@goodmis.org>
Cc: linux-kernel@vger.kernel.org
Cc: akpm@linux-foundation.org
Cc: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Dave Young <dyoung@redhat.com>
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Suggested-by: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
2018-03-15 13:25:36 +01:00
Song Liu 615755a77b bpf: extend stackmap to save binary_build_id+offset instead of address
Currently, bpf stackmap store address for each entry in the call trace.
To map these addresses to user space files, it is necessary to maintain
the mapping from these virtual address to symbols in the binary. Usually,
the user space profiler (such as perf) has to scan /proc/pid/maps at the
beginning of profiling, and monitor mmap2() calls afterwards. Given the
cost of maintaining the address map, this solution is not practical for
system wide profiling that is always on.

This patch tries to solve this problem with a variation of stackmap. This
variation is enabled by flag BPF_F_STACK_BUILD_ID. Instead of storing
addresses, the variation stores ELF file build_id + offset.

Build ID is a 20-byte unique identifier for ELF files. The following
command shows the Build ID of /bin/bash:

  [user@]$ readelf -n /bin/bash
  ...
    Build ID: XXXXXXXXXX
  ...

With BPF_F_STACK_BUILD_ID, bpf_get_stackid() tries to parse Build ID
for each entry in the call trace, and translate it into the following
struct:

  struct bpf_stack_build_id_offset {
          __s32           status;
          unsigned char   build_id[BPF_BUILD_ID_SIZE];
          union {
                  __u64   offset;
                  __u64   ip;
          };
  };

The search of build_id is limited to the first page of the file, and this
page should be in page cache. Otherwise, we fallback to store ip for this
entry (ip field in struct bpf_stack_build_id_offset). This requires the
build_id to be stored in the first page. A quick survey of binary and
dynamic library files in a few different systems shows that almost all
binary and dynamic library files have build_id in the first page.

Build_id is only meaningful for user stack. If a kernel stack is added to
a stackmap with BPF_F_STACK_BUILD_ID, it will automatically fallback to
only store ip (status == BPF_STACK_BUILD_ID_IP). Similarly, if build_id
lookup failed for some reason, it will also fallback to store ip.

User space can access struct bpf_stack_build_id_offset with bpf
syscall BPF_MAP_LOOKUP_ELEM. It is necessary for user space to
maintain mapping from build id to binary files. This mostly static
mapping is much easier to maintain than per process address maps.

Note: Stackmap with build_id only works in non-nmi context at this time.
This is because we need to take mm->mmap_sem for find_vma(). If this
changes, we would like to allow build_id lookup in nmi context.

Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-03-15 01:09:28 +01:00
Palmer Dabbelt caacdbf4aa genirq: Add CONFIG_GENERIC_IRQ_MULTI_HANDLER
The arm multi irq handler registration mechanism has been copied into a
handful of architectures, including arm64 and openrisc. RISC-V needs the
same mechanism.

Instead of adding yet another copy for RISC-V copy the arm implementation
into the core code depending on a new Kconfig symbol:
CONFIG_GENERIC_MULTI_IRQ_HANDLER.

Subsequent patches will convert the various architectures.

Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: jonas@southpole.se
Cc: catalin.marinas@arm.com
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux@armlinux.org.uk
Cc: stefan.kristiansson@saunalahti.fi
Cc: openrisc@lists.librecores.org
Cc: shorne@gmail.com
Cc: linux-riscv@lists.infradead.org
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lkml.kernel.org/r/20180307235731.22627-2-palmer@sifive.com
2018-03-14 21:46:29 +01:00
Thomas Gleixner b0d8bef8ed Merge branch 'linus' into irq/core to pick up dependencies. 2018-03-14 20:37:31 +01:00
Steven Rostedt (VMware) 80765597bc tracing: Rewrite filter logic to be simpler and faster
Al Viro reviewed the filter logic of ftrace trace events and found it to be
very troubling. It creates a binary tree based on the logic operators and
walks it during tracing. He sent myself and Tom Zanussi a long explanation
(and formal proof) of how to do the string parsing better and end up with a
program array that can be simply iterated to come up with the correct
results.

I took his ideas and his pseudo code and rewrote the filter logic based on
them. In doing so, I was able to remove a lot of code, and have a much more
condensed filter logic in the process. I wrote a very long comment
describing the methadology that Al proposed in my own words. For more info
on how this works, read the comment above predicate_parse().

Suggested-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-03-14 12:35:39 -04:00
Steven Rostedt (VMware) 478325f188 tracing: Clean up and document pred_funcs_##type creation and use
The pred_funcs_##type arrays consist of five functions that are assigned
based on the ops. The array must be in the same order of the ops each
function represents. The PRED_FUNC_START macro denotes the op enum that
starts the op that maps to the pred_funcs_##type arrays. This is all very
subtle and prone to bugs if the code is changed.

Add comments describing how PRED_FUNC_START and pred_funcs_##type array is
used, and also a PRED_FUNC_MAX that is the maximum number of functions in
the arrays.

Clean up select_comparison_fn() that assigns the predicates to the
pred_funcs_##type array function as well as add protection in case an op is
passed in that does not map correctly to the array.

Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-03-14 12:35:20 -04:00
Steven Rostedt (VMware) e9baef0d86 tracing: Combine enum and arrays into single macro in filter code
Instead of having a separate enum that is the index into another array, like
a string array, make a single macro that combines them into a single list,
and then the two can not get out of sync. This makes it easier to add and
remove items.

The macro trick is:

 #define DOGS				\
  C( JACK,     "Jack Russell")		\
  C( ITALIAN,  "Italian Greyhound")	\
  C( GERMAN,   "German Shepherd")

 #undef C
 #define C(a, b) a

 enum { DOGS };

 #undef C
 #define C(a, b) b

 static char dogs[] = { DOGS };

Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-03-14 12:32:18 -04:00
Lai Jiangshan 17a2f1ced0 cpu/hotplug: Merge cpuhp_bp_states and cpuhp_ap_states
cpuhp_bp_states and cpuhp_ap_states have different set of steps without any
conflicting steps, so that they can be merged.

The original `[CPUHP_BRINGUP_CPU] = { },` is removed, because the new
cpuhp_hp_states has CPUHP_ONLINE index which is larger than
CPUHP_BRINGUP_CPU.

Signed-off-by: Lai Jiangshan <jiangshanlai@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Link: https://lkml.kernel.org/r/20171201135008.21633-1-jiangshanlai@gmail.com
2018-03-14 16:38:43 +01:00
Josh Poimboeuf af1d830bf3 jump_label: Fix sparc64 warning
The kbuild test robot reported the following warning on sparc64:

  kernel/jump_label.c: In function '__jump_label_update':
  kernel/jump_label.c:376:51: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
       WARN_ONCE(1, "can't patch jump_label at %pS", (void *)entry->code);

On sparc64, the jump_label entry->code field is of type u32, but
pointers are 64-bit.  Silence the warning by casting entry->code to an
unsigned long before casting it to a pointer.  This is also what the
sparc jump label code does.

Fixes: dc1dd184c2 ("jump_label: Warn on failed jump_label patching attempt")
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Jason Baron <jbaron@akamai.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: "David S . Miller" <davem@davemloft.net>
Link: https://lkml.kernel.org/r/c966fed42be6611254a62d46579ec7416548d572.1521041026.git.jpoimboe@redhat.com
2018-03-14 16:35:26 +01:00
Stephen Hemminger 6417250d3f workqueue: remove unused cancel_work()
Found this by accident.
There are no usages of bare cancel_work() in current kernel source.

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
2018-03-13 13:37:42 -07:00
Arvind Yadav 537f4146c5 workqueue: use put_device() instead of kfree()
Never directly free @dev after calling device_register(), even
if it returned an error! Always use put_device() to give up the
reference initialized in this function instead.

Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2018-03-13 13:26:03 -07:00
Milind Chabbi 32ff77e8cc perf/core: Implement fast breakpoint modification via _IOC_MODIFY_ATTRIBUTES
Problem and motivation: Once a breakpoint perf event (PERF_TYPE_BREAKPOINT)
is created, there is no flexibility to change the breakpoint type
(bp_type), breakpoint address (bp_addr), or breakpoint length (bp_len). The
only option is to close the perf event and configure a new breakpoint
event. This inflexibility has a significant performance overhead. For
example, sampling-based, lightweight performance profilers (and also
concurrency bug detection tools),  monitor different addresses for a short
duration using PERF_TYPE_BREAKPOINT and change the address (bp_addr) to
another address or change the kind of breakpoint (bp_type) from  "write" to
a "read" or vice-versa or change the length (bp_len) of the address being
monitored. The cost of these modifications is prohibitive since it involves
unmapping the circular buffer associated with the perf event, closing the
perf event, opening another perf event and mmaping another circular buffer.

Solution: The new ioctl flag for perf events,
PERF_EVENT_IOC_MODIFY_ATTRIBUTES, introduced in this patch takes a pointer
to a struct perf_event_attr as an argument to update an old breakpoint
event with new address, type, and size. This facility allows retaining a
previous mmaped perf events ring buffer and avoids having to close and
reopen another perf event.

This patch supports only changing PERF_TYPE_BREAKPOINT event type; future
implementations can extend this feature. The patch replicates some of its
functionality of modify_user_hw_breakpoint() in
kernel/events/hw_breakpoint.c. modify_user_hw_breakpoint cannot be called
directly since perf_event_ctx_lock() is already held in _perf_ioctl().

Evidence: Experiments show that the baseline (not able to modify an already
created breakpoint) costs an order of magnitude (~10x) more than the
suggested optimization (having the ability to dynamically modifying a
configured breakpoint via ioctl). When the breakpoints typically do not
trap, the speedup due to the suggested optimization is ~10x; even when the
breakpoints always trap, the speedup is ~4x due to the suggested
optimization.

Testing: tests posted at
https://github.com/linux-contrib/perf_event_modify_bp demonstrate the
performance significance of this patch. Tests also check the functional
correctness of the patch.

Signed-off-by: Milind Chabbi <chabbi.milind@gmail.com>
[ Using modify_user_hw_breakpoint_check function. ]
[ Reformated PERF_EVENT_IOC_*, so the values are all in one column. ]
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Hari Bathini <hbathini@linux.vnet.ibm.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Oleg Nesterov <onestero@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Link: http://lkml.kernel.org/r/20180312134548.31532-8-jolsa@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-13 15:24:02 +01:00
Thomas Gleixner 92af4dcb4e tracing: Unify the "boot" and "mono" tracing clocks
Unify the "boot" and "mono" tracing clocks and document the new behaviour.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kevin Easton <kevin@guarana.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Salyzyn <salyzyn@android.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20180301165150.489635255@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-13 07:34:23 +01:00
Thomas Gleixner 127bfa5f43 hrtimer: Unify MONOTONIC and BOOTTIME clock behavior
Now that th MONOTONIC and BOOTTIME clocks are indentical remove all the special
casing.

The user space visible interfaces still support both clocks, but their behavior
is identical.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kevin Easton <kevin@guarana.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Salyzyn <salyzyn@android.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20180301165150.410218515@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-13 07:34:23 +01:00
Thomas Gleixner 7250a4047a posix-timers: Unify MONOTONIC and BOOTTIME clock behavior
Now that the MONOTONIC and BOOTTIME clocks are indentical remove all the special
casing.

The user space visible interfaces still support both clocks, but their behavior
is identical.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kevin Easton <kevin@guarana.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Salyzyn <salyzyn@android.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20180301165150.315745557@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-13 07:34:22 +01:00
Thomas Gleixner d6c7270e91 timekeeping: Remove boot time specific code
Now that the MONOTONIC and BOOTTIME clocks are the same, remove all the
special handling from timekeeping. Keep wrappers for the existing users of
the *boot* timekeeper interfaces.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kevin Easton <kevin@guarana.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Salyzyn <salyzyn@android.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20180301165150.236279497@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-13 07:34:22 +01:00
Thomas Gleixner d6ed449afd timekeeping: Make the MONOTONIC clock behave like the BOOTTIME clock
The MONOTONIC clock is not fast forwarded by the time spent in suspend on
resume. This is only done for the BOOTTIME clock. The reason why the
MONOTONIC clock is not forwarded is historical: the original Linux
implementation was using jiffies as a base for the MONOTONIC clock and
jiffies have never been advanced after resume.

At some point when timekeeping was unified in the core code, the
MONONOTIC clock was advanced after resume which also advanced jiffies causing
interesting side effects. As a consequence the the MONOTONIC clock forwarding
was disabled again and the BOOTTIME clock was introduced, which allows to read
time since boot.

Back then it was not possible to completely distangle the MONOTONIC clock and
jiffies because there were still interfaces which exposed the MONOTONIC clock
behaviour based on the timer wheel and therefore jiffies.

As of today none of the MONOTONIC clock facilities depends on jiffies
anymore so the forwarding can be done seperately. This is achieved by
forwarding the variables which are used for the jiffies update after resume
before the tick is restarted,

In timekeeping resume, the change is rather simple. Instead of updating the
offset between the MONOTONIC clock and the REALTIME/BOOTTIME clocks, advance the
time keeper base for the MONOTONIC and the MONOTONIC_RAW clocks by the time
spent in suspend.

The MONOTONIC clock is now the same as the BOOTTIME clock and the offset between
the REALTIME and the MONOTONIC clocks is the same as before suspend.

There might be side effects in applications, which rely on the
(unfortunately) well documented behaviour of the MONOTONIC clock, but the
downsides of the existing behaviour are probably worse.

There is one obvious issue. Up to now it was possible to retrieve the time
spent in suspend by observing the delta between the MONOTONIC clock and the
BOOTTIME clock. This is not longer available, but the previously introduced
mechanism to read the active non-suspended monotonic time can mitigate that
in a detectable fashion.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kevin Easton <kevin@guarana.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Salyzyn <salyzyn@android.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20180301165150.062975504@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-13 07:34:22 +01:00
Thomas Gleixner 72199320d4 timekeeping: Add the new CLOCK_MONOTONIC_ACTIVE clock
The planned change to unify the behaviour of the MONOTONIC and BOOTTIME
clocks vs. suspend removes the ability to retrieve the active
non-suspended time of a system.

Provide a new CLOCK_MONOTONIC_ACTIVE clock which returns the active
non-suspended time of the system via clock_gettime().

This preserves the old behaviour of CLOCK_MONOTONIC before the
BOOTTIME/MONOTONIC unification.

This new clock also allows applications to detect programmatically that
the MONOTONIC and BOOTTIME clocks are identical.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kevin Easton <kevin@guarana.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Salyzyn <salyzyn@android.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20180301165149.965235774@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-13 07:34:21 +01:00
Jiri Olsa 5f970521d3 perf/core: Move perf_event_attr::sample_max_stack into perf_copy_attr()
Move the sample_max_stack check and setup into perf_copy_attr(),
so we have all perf_event_attr initial setup in one place
and can easily compare attrs in the new ioctl introduced
in following change.

Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Hari Bathini <hbathini@linux.vnet.ibm.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Milind Chabbi <chabbi.milind@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Oleg Nesterov <onestero@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Link: http://lkml.kernel.org/r/20180312134548.31532-7-jolsa@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-13 06:56:08 +01:00
Jiri Olsa 705feaf321 hw_breakpoint: Add perf_event_attr fields check in __modify_user_hw_breakpoint()
And rename it to modify_user_hw_breakpoint_check().

We are about to use modify_user_hw_breakpoint_check() for user space
breakpoints modification, we must be very strict to check only the
fields we can change have changed. As Peter explained:

 "Suppose someone does:

        attr = malloc(sizeof(*attr)); // uninitialized memory
        attr->type = BP;
        attr->bp_addr = new_addr;
        attr->bp_type = bp_type;
        attr->bp_len = bp_len;
        ioctl(fd, PERF_IOC_MOD_ATTR, &attr);

  And feeds absolute shite for the rest of the fields.
  Then we later want to extend IOC_MOD_ATTR to allow changing
  attr::sample_type but we can't, because that would break the
  above application."

I'm making this check optional because we already export
modify_user_hw_breakpoint() and with this check we could
break existing users.

Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Hari Bathini <hbathini@linux.vnet.ibm.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Milind Chabbi <chabbi.milind@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Oleg Nesterov <onestero@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Link: http://lkml.kernel.org/r/20180312134548.31532-6-jolsa@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-13 06:56:08 +01:00
Jiri Olsa 18ff57b220 hw_breakpoint: Factor out __modify_user_hw_breakpoint() function
Moving out all the functionality without the events
disabling/enabling calls, because we want to call another
disabling/enabling functions in following change.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Hari Bathini <hbathini@linux.vnet.ibm.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Milind Chabbi <chabbi.milind@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Oleg Nesterov <onestero@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Link: http://lkml.kernel.org/r/20180312134548.31532-5-jolsa@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-13 06:56:08 +01:00
Jiri Olsa ea6a9d530c hw_breakpoint: Add modify_bp_slot() function
Add the modify_bp_slot() function to keep slot numbers
correct when changing the breakpoint type.

Using existing __release_bp_slot()/__reserve_bp_slot()
call sequence to update the slot counts.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Hari Bathini <hbathini@linux.vnet.ibm.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Milind Chabbi <chabbi.milind@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Oleg Nesterov <onestero@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Link: http://lkml.kernel.org/r/20180312134548.31532-4-jolsa@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-13 06:56:07 +01:00
Jiri Olsa 1ad9ff7dea hw_breakpoint: Pass bp_type argument to __reserve_bp_slot|__release_bp_slot()
Passing bp_type argument to __reserve_bp_slot() and __release_bp_slot()
functions, so we can pass another bp_type than the one defined in
bp->attr.bp_type. This will be handy in following change that fixes
breakpoint slot counts during its modification.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Hari Bathini <hbathini@linux.vnet.ibm.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Milind Chabbi <chabbi.milind@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Oleg Nesterov <onestero@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Link: http://lkml.kernel.org/r/20180312134548.31532-3-jolsa@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-13 06:56:07 +01:00
Jiri Olsa cbd9d9f114 hw_breakpoint: Pass bp_type directly as find_slot_idx() argument
Pass bp_type directly as a find_slot_idx() argument,
so we don't need to have whole event to get the
breakpoint slot type. It will be used in following
changes.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Hari Bathini <hbathini@linux.vnet.ibm.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Milind Chabbi <chabbi.milind@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Oleg Nesterov <onestero@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Link: http://lkml.kernel.org/r/20180312134548.31532-2-jolsa@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-13 06:56:07 +01:00
Masami Hiramatsu b6b76dd62c error-injection: Fix to prohibit jump optimization
Since the kprobe which was optimized by jump can not change
the execution path, the kprobe for error-injection must not
be optimized. To prohibit it, set a dummy post-handler as
officially stated in Documentation/kprobes.txt.

Fixes: 4b1a29a7f5 ("error-injection: Support fault injection framework")
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-03-12 16:16:00 +01:00
leilei.lin 33801b9474 perf/core: Fix installing cgroup events on CPU
There's two problems when installing cgroup events on CPUs: firstly
list_update_cgroup_event() only tries to set cpuctx->cgrp for the
first event, if that mismatches on @cgrp we'll not try again for later
additions.

Secondly, when we install a cgroup event into an active context, only
issue an event reprogram when the event matches the current cgroup
context. This avoids a pointless event reprogramming.

Signed-off-by: leilei.lin <leilei.lin@alibaba-inc.com>
[ Improved the changelog and comments. ]
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: brendan.d.gregg@gmail.com
Cc: eranian@gmail.com
Cc: linux-kernel@vger.kernel.org
Cc: yang_oliver@hotmail.com
Link: http://lkml.kernel.org/r/20180306093637.28247-1-linxiulei@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-12 15:28:51 +01:00
Peter Zijlstra 8d5bce0c37 perf/core: Optimize perf_rotate_context() event scheduling
The event schedule order (as per perf_event_sched_in()) is:

 - cpu  pinned
 - task pinned
 - cpu  flexible
 - task flexible

But perf_rotate_context() will unschedule cpu-flexible even if it
doesn't need a rotation.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-12 15:28:50 +01:00
Peter Zijlstra 8703a7cfe1 perf/core: Fix tree based event rotation
Similar to how first programming cpu=-1 and then cpu=# is wrong, so is
rotating both. It was especially wrong when we were still programming
the PMU in this same order, because in that scenario we might never
actually end up running cpu=# events at all.

Cure this by using the active_list to pick the rotation event; since
at programming we already select the left-most event.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Carrillo-Cisneros <davidcc@google.com>
Cc: Dmitri Prokhorov <Dmitry.Prohorov@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Valery Cherepennikov <valery.cherepennikov@intel.com>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-12 15:28:50 +01:00
Peter Zijlstra 6e6804d2fa perf/core: Simpify perf_event_groups_for_each()
The last argument is, and always must be, the same.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Carrillo-Cisneros <davidcc@google.com>
Cc: Dmitri Prokhorov <Dmitry.Prohorov@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Valery Cherepennikov <valery.cherepennikov@intel.com>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-12 15:28:50 +01:00
Peter Zijlstra 6668128a9e perf/core: Optimize ctx_sched_out()
When an event group contains more events than can be scheduled on the
hardware, iterating the full event group for ctx_sched_out is a waste
of time.

Keep track of the events that got programmed on the hardware, such
that we can iterate this smaller list in order to schedule them out.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Carrillo-Cisneros <davidcc@google.com>
Cc: Dmitri Prokhorov <Dmitry.Prohorov@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Valery Cherepennikov <valery.cherepennikov@intel.com>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-12 15:28:50 +01:00
Peter Zijlstra 8343aae661 perf/core: Remove perf_event::group_entry
Now that all the grouping is done with RB trees, we no longer need
group_entry and can replace the whole thing with sibling_list.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Carrillo-Cisneros <davidcc@google.com>
Cc: Dmitri Prokhorov <Dmitry.Prohorov@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Valery Cherepennikov <valery.cherepennikov@intel.com>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-12 15:28:49 +01:00
Peter Zijlstra 1cac7b1ae3 perf/core: Fix event schedule order
Scheduling in events with cpu=-1 before events with cpu=# changes
semantics and is undesirable in that it would priorize these events.

Given that groups->index is across all groups we actually have an
inter-group ordering, meaning we can merge-sort two groups, which is
just what we need to preserve semantics.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Carrillo-Cisneros <davidcc@google.com>
Cc: Dmitri Prokhorov <Dmitry.Prohorov@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Valery Cherepennikov <valery.cherepennikov@intel.com>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-12 15:28:49 +01:00
Peter Zijlstra 161c85fab7 perf/core: Cleanup the rb-tree code
Trivial comment and code fixups..

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Carrillo-Cisneros <davidcc@google.com>
Cc: Dmitri Prokhorov <Dmitry.Prohorov@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Valery Cherepennikov <valery.cherepennikov@intel.com>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-12 15:28:49 +01:00
Alexey Budankov 8e1a2031e4 perf/cor: Use RB trees for pinned/flexible groups
Change event groups into RB trees sorted by CPU and then by a 64bit
index, so that multiplexing hrtimer interrupt handler would be able
skipping to the current CPU's list and ignore groups allocated for the
other CPUs.

New API for manipulating event groups in the trees is implemented as well
as adoption on the API in the current implementation.

pinned_group_sched_in() and flexible_group_sched_in() API are
introduced to consolidate code enabling the whole group from pinned
and flexible groups appropriately.

Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: David Carrillo-Cisneros <davidcc@google.com>
Cc: Dmitri Prokhorov <Dmitry.Prohorov@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Valery Cherepennikov <valery.cherepennikov@intel.com>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/372f9c8b-0cfe-4240-e44d-83d863d40813@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-12 15:28:49 +01:00
Peter Zijlstra 9e5b127d6f perf/core: Fix perf_output_read_group()
Mark reported his arm64 perf fuzzer runs sometimes splat like:

  armv8pmu_read_counter+0x1e8/0x2d8
  armpmu_event_update+0x8c/0x188
  armpmu_read+0xc/0x18
  perf_output_read+0x550/0x11e8
  perf_event_read_event+0x1d0/0x248
  perf_event_exit_task+0x468/0xbb8
  do_exit+0x690/0x1310
  do_group_exit+0xd0/0x2b0
  get_signal+0x2e8/0x17a8
  do_signal+0x144/0x4f8
  do_notify_resume+0x148/0x1e8
  work_pending+0x8/0x14

which asserts that we only call pmu::read() on ACTIVE events.

The above callchain does:

  perf_event_exit_task()
    perf_event_exit_task_context()
      task_ctx_sched_out() // INACTIVE
      perf_event_exit_event()
        perf_event_set_state(EXIT) // EXIT
        sync_child_event()
          perf_event_read_event()
            perf_output_read()
              perf_output_read_group()
                leader->pmu->read()

Which results in doing a pmu::read() on an !ACTIVE event.

I _think_ this is 'new' since we added attr.inherit_stat, which added
the perf_event_read_event() to the exit path, without that
perf_event_read_output() would only trigger from samples and for
@event to trigger a sample, it's leader _must_ be ACTIVE too.

Still, adding this check makes it consistent with the @sub case for
the siblings.

Reported-and-Tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-12 15:28:48 +01:00
Ingo Molnar 9884afa2fd Linux 4.16-rc5
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Merge tag 'v4.16-rc5' into locking/core, to pick up fixes

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-12 12:14:57 +01:00
Linus Torvalds 8ad4424350 Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf updates from Thomas Gleixner:
 "Another set of perf updates:

   - Fix a Skylake Uncore event format declaration

   - Prevent perf pipe mode from crahsing which was caused by a missing
     buffer allocation

   - Make the perf top popup message which tells the user that it uses
     fallback mode on older kernels a debug message.

   - Make perf context rescheduling work correcctly

   - Robustify the jump error drawing in perf browser mode so it does
     not try to create references to NULL initialized offset entries

   - Make trigger_on() robust so it does not enable the trigger before
     everything is set up correctly to handle it

   - Make perf auxtrace respect the --no-itrace option so it does not
     try to queue AUX data for decoding.

   - Prevent having different number of field separators in CVS output
     lines when a counter is not supported.

   - Make the perf kallsyms man page usage behave like it does for all
     other perf commands.

   - Synchronize the kernel headers"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/core: Fix ctx_event_type in ctx_resched()
  perf tools: Fix trigger class trigger_on()
  perf auxtrace: Prevent decoding when --no-itrace
  perf stat: Fix CVS output format for non-supported counters
  tools headers: Sync x86's cpufeatures.h
  tools headers: Sync copy of kvm UAPI headers
  perf record: Fix crash in pipe mode
  perf annotate browser: Be more robust when drawing jump arrows
  perf top: Fix annoying fallback message on older kernels
  perf kallsyms: Fix the usage on the man page
  perf/x86/intel/uncore: Fix Skylake UPI event format
2018-03-11 14:49:49 -07:00
Linus Torvalds 02bf0ef028 Merge branch 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking fix from Thomas Gleixner:
 "rt_mutex_futex_unlock() grew a new irq-off call site, but the function
  assumes that its always called from irq enabled context.

  Use (un)lock_irqsafe() to handle the new call site correctly"

* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  rtmutex: Make rt_mutex_futex_unlock() safe for irq-off callsites
2018-03-11 14:46:54 -07:00
Ingo Molnar c4fb5f3700 Merge branch 'for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu
Pull RCU updates from Paul E. McKenney:

 - Miscellaneous fixes, perhaps most notably removing obsolete
   code whose only purpose in life was to gather information for
   the now-removed RCU debugfs facility.  Other notable changes
   include removing NO_HZ_FULL_ALL in favor of the nohz_full kernel
   boot parameter, minor optimizations for expedited grace periods,
   some added tracing, creating an RCU-specific workqueue using Tejun's
   new WQ_MEM_RECLAIM flag, and several cleanups to code and comments.

 - SRCU cleanups and optimizations.

 - Torture-test updates, perhaps most notably the adding of ARMv8
   support, but also including numerous cleanups and usability fixes.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-11 10:42:16 +01:00
Steven Rostedt (VMware) 567f6989fd tracing: Embed replace_filter_string() helper function
The replace_filter_string() frees the current string and then copies a given
string. But in the two locations that it was used, the allocation happened
right after the filter was allocated (nothing to replace). There's no need
for this to be a helper function. Embedding the allocation in the two places
where it was called will make changing the code in the future easier.

Also make the variable consistent (always use "filter_string" as the name,
as it was used in one instance as "filter_str")

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-03-10 16:06:07 -05:00
Steven Rostedt (VMware) 404a3add43 tracing: Only add filter list when needed
replace_system_preds() creates a filter list to free even when it doesn't
really need to have it. Only save filters that require synchronize_sched()
in the filter list to free. This will allow the code to be updated a bit
easier in the future.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-03-10 16:06:07 -05:00
Steven Rostedt (VMware) c7399708b3 tracing: Remove filter allocator helper
The __alloc_filter() function does nothing more that allocate the filter.
There's no reason to have it as a helper function.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-03-10 16:06:06 -05:00
Steven Rostedt (VMware) 559d421267 tracing: Use trace_seq instead of open code string appending
The filter code does open code string appending to produce an error message.
Instead it can be simplified by using trace_seq function helpers.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-03-10 16:06:06 -05:00
Steven Rostedt (VMware) a0ff08fd4e tracing: Remove BUG_ON() from append_filter_string()
There's no reason to BUG if there's a bug in the filtering code. Simply do a
warning and return.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-03-10 16:06:05 -05:00
Tom Zanussi 89e270c1df tracing: Add inter-event blurb to HIST_TRIGGERS config option
So that users know that inter-event tracing is supported as part of
the HIST_TRIGGERS option, include text to that effect in the help
text.

Link: http://lkml.kernel.org/r/a38e24231d8d980be636b56d35814570acfd167a.1516069914.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-03-10 16:06:05 -05:00
Steven Rostedt (VMware) 4708abc6c6 tracing: Use the ring-buffer nesting to allow synthetic events to be traced
Synthetic events can be done within the recording of other events. Notify
the ring buffer via ring_buffer_nest_start() and ring_buffer_nest_end() that
this is intended and not to block it due to its recursion protection.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-03-10 16:06:04 -05:00
Steven Rostedt (VMware) 8e012066fe ring-buffer: Add nesting for adding events within events
The ring-buffer code has recusion protection in case tracing ends up tracing
itself, the ring-buffer will detect that it was called at the same context
(normal, softirq, interrupt or NMI), and not continue to record the event.

With the histogram synthetic events, they are called while tracing another
event at the same context. The recusion protection triggers because it
detects tracing at the same context and stops it.

Add ring_buffer_nest_start() and ring_buffer_nest_end() that will notify the
ring buffer that a trace is about to happen within another trace and that it
is intended, and not to trigger the recursion blocking.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-03-10 16:06:04 -05:00
Tom Zanussi a4072fe85b tracing: Add a clock attribute for hist triggers
The default clock if timestamps are used in a histogram is "global".
If timestamps aren't used, the clock is irrelevant.

Use the "clock=" param only if you want to override the default
"global" clock for a histogram with timestamps.

Link: http://lkml.kernel.org/r/427bed1389c5d22aa40c3e0683e30cc3d151e260.1516069914.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Rajvi Jingar <rajvi.jingar@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-03-10 16:06:03 -05:00
Tom Zanussi d71bd34d78 tracing: Make tracing_set_clock() non-static
Allow tracing code outside of trace.c to access tracing_set_clock().

Some applications may require a particular clock in order to function
properly, such as latency calculations.

Also, add an accessor returning the current clock string.

Link: http://lkml.kernel.org/r/6d1c53e9ee2163f54e1849f5376573f54f0e6009.1516069914.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-03-10 16:06:03 -05:00
Tom Zanussi f404da6e1d tracing: Add 'last error' error facility for hist triggers
With the addition of variables and actions, it's become necessary to
provide more detailed error information to users about syntax errors.

Add a 'last error' facility accessible via the erroring event's 'hist'
file.  Reading the hist file after an error will display more detailed
information about what went wrong, if information is available.  This
extended error information will be available until the next hist
trigger command for that event.

  # echo xxx > /sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
  echo: write error: Invalid argument

  # cat /sys/kernel/debug/tracing/events/sched/sched_wakeup/hist

  ERROR: Couldn't yyy: zzz
  Last command: xxx

Also add specific error messages for variable and action errors.

Link: http://lkml.kernel.org/r/64e9c422fc8aeafcc2f7a3b4328c0cffe7969129.1516069914.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-03-10 16:06:02 -05:00
Tom Zanussi 7e8b88a30b tracing: Add hist trigger support for variable reference aliases
Add support for alias=$somevar where alias can be used as
onmatch.xxx($alias).

Aliases are a way of creating a new name for an existing variable, for
flexibly in making naming more clear in certain cases.  For example in
the below the user perhaps feels that using $new_lat in the synthetic
event invocation is opaque or doesn't fit well stylistically with
previous triggers, so creates an alias of $new_lat named $latency and
uses that in the call instead:

  # echo 'hist:keys=next_pid:new_lat=common_timestamp.usecs' >
    /sys/kernel/debug/tracing/events/sched/sched_switch/trigger

  # echo 'hist:keys=pid:latency=$new_lat:
    onmatch(sched.sched_switch).wake2($latency,pid)' >
    /sys/kernel/debug/tracing/events/synthetic/wake1/trigger

Link: http://lkml.kernel.org/r/ef20a65d921af3a873a6f1e8c71407c926d5586f.1516069914.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-03-10 16:06:01 -05:00
Tom Zanussi 8b7622bf94 tracing: Add cpu field for hist triggers
A common key to use in a histogram is the cpuid - add a new cpu
'synthetic' field named 'cpu' for that purpose.

Link: http://lkml.kernel.org/r/89537645bfc957e0d76e2cacf5f0ada88691a6cc.1516069914.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-03-10 16:06:01 -05:00
Tom Zanussi ec5ce09875 tracing: Allow whitespace to surround hist trigger filter
The existing code only allows for one space before and after the 'if'
specifying the filter for a hist trigger.  Add code to make that more
permissive as far as whitespace goes.  Specifically, we want to allow
spaces in the trigger itself now that we have additional syntax
(onmatch/onmax) where spaces are more natural e.g. spaces after commas
in param lists.

Link: http://lkml.kernel.org/r/1053090c3c308d4f431accdeb59dff4b511d4554.1516069914.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-03-10 16:06:00 -05:00
Tom Zanussi 50450603ec tracing: Add 'onmax' hist trigger action support
Add an 'onmax(var).save(field,...)' hist trigger action which is
invoked whenever an event exceeds the current maximum.

The end result is that the trace event fields or variables specified
as the onmax.save() params will be saved if 'var' exceeds the current
maximum for that hist trigger entry.  This allows context from the
event that exhibited the new maximum to be saved for later reference.
When the histogram is displayed, additional fields displaying the
saved values will be printed.

As an example the below defines a couple of hist triggers, one for
sched_wakeup and another for sched_switch, keyed on pid.  Whenever a
sched_wakeup occurs, the timestamp is saved in the entry corresponding
to the current pid, and when the scheduler switches back to that pid,
the timestamp difference is calculated.  If the resulting latency
exceeds the current maximum latency, the specified save() values are
saved:

    # echo 'hist:keys=pid:ts0=common_timestamp.usecs \
        if comm=="cyclictest"' >> \
      /sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger

    # echo 'hist:keys=next_pid:\
      wakeup_lat=common_timestamp.usecs-$ts0:\
      onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \
        if next_comm=="cyclictest"' >> \
      /sys/kernel/debug/tracing/events/sched/sched_switch/trigger

When the histogram is displayed, the max value and the saved values
corresponding to the max are displayed following the rest of the
fields:

    # cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist

      { next_pid:       3728 } hitcount:        199 \
        max:        123  next_comm: cyclictest  prev_pid:          0 \
	prev_prio:        120  prev_comm: swapper/3
      { next_pid:       3730 } hitcount:       1321 \
        max:         15  next_comm: cyclictest  prev_pid:          0 \
	prev_prio:        120  prev_comm: swapper/1
      { next_pid:       3729 } hitcount:       1973\
        max:         25  next_comm: cyclictest  prev_pid:          0  \
	prev_prio:        120  prev_comm: swapper/0

    Totals:
        Hits: 3493
        Entries: 3
	Dropped: 0

Link: http://lkml.kernel.org/r/006907f71b1e839bb059337ec3c496f84fcb71de.1516069914.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-03-10 16:06:00 -05:00
Tom Zanussi c282a386a3 tracing: Add 'onmatch' hist trigger action support
Add an 'onmatch(matching.event).<synthetic_event_name>(param list)'
hist trigger action which is invoked with the set of variables or
event fields named in the 'param list'.  The result is the generation
of a synthetic event that consists of the values contained in those
variables and/or fields at the time the invoking event was hit.

As an example the below defines a simple synthetic event using a
variable defined on the sched_wakeup_new event, and shows the event
definition with unresolved fields, since the sched_wakeup_new event
with the testpid variable hasn't been defined yet:

    # echo 'wakeup_new_test pid_t pid; int prio' >> \
      /sys/kernel/debug/tracing/synthetic_events

    # cat /sys/kernel/debug/tracing/synthetic_events
      wakeup_new_test pid_t pid; int prio

The following hist trigger both defines a testpid variable and
specifies an onmatch() trace action that uses that variable along with
a non-variable field to generate a wakeup_new_test synthetic event
whenever a sched_wakeup_new event occurs, which because of the 'if
comm == "cyclictest"' filter only happens when the executable is
cyclictest:

    # echo 'hist:testpid=pid:keys=$testpid:\
      onmatch(sched.sched_wakeup_new).wakeup_new_test($testpid, prio) \
        if comm=="cyclictest"' >> \
      /sys/kernel/debug/tracing/events/sched/sched_wakeup_new/trigger

Creating and displaying a histogram based on those events is now just
a matter of using the fields and new synthetic event in the
tracing/events/synthetic directory, as usual:

    # echo 'hist:keys=pid,prio:sort=pid,prio' >> \
      /sys/kernel/debug/tracing/events/synthetic/wakeup_new_test/trigger

Link: http://lkml.kernel.org/r/8c2a574bcb7530c876629c901ecd23911b14afe8.1516069914.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Rajvi Jingar <rajvi.jingar@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-03-10 16:05:59 -05:00
Tom Zanussi 02205a6752 tracing: Add support for 'field variables'
Users should be able to directly specify event fields in hist trigger
'actions' rather than being forced to explicitly create a variable for
that purpose.

Add support allowing fields to be used directly in actions, which
essentially does just that - creates 'invisible' variables for each
bare field specified in an action.  If a bare field refers to a field
on another (matching) event, it even creates a special histogram for
the purpose (since variables can't be defined on an existing histogram
after histogram creation).

Here's a simple example that demonstrates both.  Basically the
onmatch() action creates a list of variables corresponding to the
parameters of the synthetic event to be generated, and then uses those
values to generate the event.  So for the wakeup_latency synthetic
event 'call' below the first param, $wakeup_lat, is a variable defined
explicitly on sched_switch, where 'next_pid' is just a normal field on
sched_switch, and prio is a normal field on sched_waking.

Since the mechanism works on variables, those two normal fields just
have 'invisible' variables created internally for them.  In the case of
'prio', which is on another event, we actually need to create an
additional hist trigger and define the invisible variable on that, since
once a hist trigger is defined, variables can't be added to it later.

  echo 'wakeup_latency u64 lat; pid_t pid; int prio' >>
       /sys/kernel/debug/tracing/synthetic_events

  echo 'hist:keys=pid:ts0=common_timestamp.usecs >>
       /sys/kernel/debug/tracing/events/sched/sched_waking/trigger

echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:
      onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,prio)
            >> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger

Link: http://lkml.kernel.org/r/8e8dcdac1ea180ed7a3689e1caeeccede9dc42b3.1516069914.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-03-10 16:05:59 -05:00
Tom Zanussi 4b147936fa tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.

To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.

For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:

    # echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
      /sys/kernel/debug/tracing/synthetic_events

Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:

    # cat /sys/kernel/debug/tracing/synthetic_events
    wakeup_latency u64 lat; pid_t pid; int prio

At this point, the synthetic event is ready to use, and a histogram
can be defined using it:

    # echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
    /sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger

The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:

    # ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
      enable  filter  format  hist  id  trigger

Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.

How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.

Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-03-10 16:05:58 -05:00
Tom Zanussi 0212e2aa30 tracing: Add hist trigger action hook
Add a hook for executing extra actions whenever a histogram entry is
added or updated.

The default 'action' when a hist entry is added to a histogram is to
update the set of values associated with it.  Some applications may
want to perform additional actions at that point, such as generate
another event, or compare and save a maximum.

Add a simple framework for doing that; specific actions will be
implemented on top of it in later patches.

Link: http://lkml.kernel.org/r/9482ba6a3eaf5ca6e60954314beacd0e25c05b24.1516069914.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-03-10 16:05:58 -05:00
Tom Zanussi 067fe038e7 tracing: Add variable reference handling to hist triggers
Add the necessary infrastructure to allow the variables defined on one
event to be referenced in another.  This allows variables set by a
previous event to be referenced and used in expressions combining the
variable values saved by that previous event and the event fields of
the current event.  For example, here's how a latency can be
calculated and saved into yet another variable named 'wakeup_lat':

    # echo 'hist:keys=pid,prio:ts0=common_timestamp ...
    # echo 'hist:keys=next_pid:wakeup_lat=common_timestamp-$ts0 ...

In the first event, the event's timetamp is saved into the variable
ts0.  In the next line, ts0 is subtracted from the second event's
timestamp to produce the latency.

Further users of variable references will be described in subsequent
patches, such as for instance how the 'wakeup_lat' variable above can
be displayed in a latency histogram.

Link: http://lkml.kernel.org/r/b1d3e6975374e34d501ff417c20189c3f9b2c7b8.1516069914.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-03-10 16:05:58 -05:00
Tom Zanussi 19a9facd0f tracing: Add hist_field 'type' field
Future support for synthetic events requires hist_field 'type'
information, so add a field for that.

Also, make other hist_field attribute usage consistent (size,
is_signed, etc).

Link: http://lkml.kernel.org/r/3fd12a2e86316b05151ba0d7c68268e780af2c9d.1516069914.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-03-10 16:05:57 -05:00
Tom Zanussi df35d93bbf tracing: Pass tracing_map_elt to hist_field accessor functions
Some accessor functions, such as for variable references, require
access to a corrsponding tracing_map_elt.

Add a tracing_map_elt param to the function signature and update the
accessor functions accordingly.

Link: http://lkml.kernel.org/r/e0f292b068e9e4948da1d5af21b5ae0efa9b5717.1516069914.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-03-10 16:05:57 -05:00
Tom Zanussi af6a29bcaf tracing: Generalize per-element hist trigger data
Up until now, hist triggers only needed per-element support for saving
'comm' data, which was saved directly as a private data pointer.

In anticipation of the need to save other data besides 'comm', add a
new hist_elt_data struct for the purpose, and switch the current
'comm'-related code over to that.

Link: http://lkml.kernel.org/r/4502c338c965ddf5fc19fb1ec4764391e001ed4b.1516069914.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-03-10 16:05:56 -05:00
Tom Zanussi 100719dcef tracing: Add simple expression support to hist triggers
Add support for simple addition, subtraction, and unary expressions
(-(expr) and expr, where expr = b-a, a+b, a+b+c) to hist triggers, in
order to support a minimal set of useful inter-event calculations.

These operations are needed for calculating latencies between events
(timestamp1-timestamp0) and for combined latencies (latencies over 3
or more events).

In the process, factor out some common code from key and value
parsing.

Link: http://lkml.kernel.org/r/9a9308ead4fe32a433d9c7e95921fb798394f6b2.1516069914.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[kbuild test robot fix, add static to parse_atom()]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
[ Replaced '//' comments with normal /* */ comments ]
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-03-10 16:05:56 -05:00
Tom Zanussi 2ece94fbd2 tracing: Move get_hist_field_flags()
Move get_hist_field_flags() to make it more easily accessible for new
code (and keep the move separate from new functionality).

Link: http://lkml.kernel.org/r/32470f0a7047ec7a6e84ba5ec89d6142cc6ede7d.1516069914.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-03-10 16:05:55 -05:00
Tom Zanussi 1a361dfcf2 tracing: Account for variables in named trigger compatibility
Named triggers must also have the same set of variables in order to be
considered compatible - update the trigger match test to account for
that.

The reason for this requirement is that named triggers with variables
are meant to allow one or more events to set the same variable.

Link: http://lkml.kernel.org/r/a17eae6328a99917f9d5c66129c9fcd355279ee9.1516069914.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-03-10 16:05:55 -05:00
Tom Zanussi 30350d65ac tracing: Add variable support to hist triggers
Add support for saving the value of a current event's event field by
assigning it to a variable that can be read by a subsequent event.

The basic syntax for saving a variable is to simply prefix a unique
variable name not corresponding to any keyword along with an '=' sign
to any event field.

Both keys and values can be saved and retrieved in this way:

    # echo 'hist:keys=next_pid:vals=$ts0:ts0=common_timestamp ...
    # echo 'hist:timer_pid=common_pid:key=$timer_pid ...'

If a variable isn't a key variable or prefixed with 'vals=', the
associated event field will be saved in a variable but won't be summed
as a value:

    # echo 'hist:keys=next_pid:ts1=common_timestamp:...

Multiple variables can be assigned at the same time:

    # echo 'hist:keys=pid:vals=$ts0,$b,field2:ts0=common_timestamp,b=field1 ...

Multiple (or single) variables can also be assigned at the same time
using separate assignments:

    # echo 'hist:keys=pid:vals=$ts0:ts0=common_timestamp:b=field1:c=field2 ...

Variables set as above can be used by being referenced from another
event, as described in a subsequent patch.

Link: http://lkml.kernel.org/r/fc93c4944d9719dbcb1d0067be627d44e98e2adc.1516069914.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Baohong Liu <baohong.liu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-03-10 16:05:54 -05:00
Tom Zanussi 860f9f6b02 tracing: Add usecs modifier for hist trigger timestamps
Appending .usecs onto a common_timestamp field will cause the
timestamp value to be in microseconds instead of the default
nanoseconds.  A typical latency histogram using usecs would look like
this:

   # echo 'hist:keys=pid,prio:ts0=common_timestamp.usecs ...
   # echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0 ...

This also adds an external trace_clock_in_ns() to trace.c for the
timestamp conversion.

Link: http://lkml.kernel.org/r/4e813705a170b3e13e97dc3135047362fb1a39f3.1516069914.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-03-10 16:05:54 -05:00
Tom Zanussi b559d003a2 tracing: Add hist_data member to hist_field
Allow hist_data access via hist_field.  Some users of hist_fields
require or will require more access to the associated hist_data.

Link: http://lkml.kernel.org/r/d04cd0768f5228ebb4ac0ba4a847bc4d14d4826f.1516069914.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-03-10 16:05:53 -05:00
Tom Zanussi 2734b62952 tracing: Add per-element variable support to tracing_map
In order to allow information to be passed between trace events, add
support for per-element variables to tracing_map.  This provides a
means for histograms to associate a value or values with an entry when
it's saved or updated, and retrieved by a subsequent event occurrences.

Variables can be set using tracing_map_set_var() and read using
tracing_map_read_var().  tracing_map_var_set() returns true or false
depending on whether or not the variable has been set or not, which is
important for event-matching applications.

tracing_map_read_var_once() reads the variable and resets it to the
'unset' state, implementing read-once variables, which are also
important for event-matching uses.

Link: http://lkml.kernel.org/r/7fa001108252556f0c6dd9d63145eabfe3370d1a.1516069914.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-03-10 16:05:53 -05:00
Tom Zanussi ad42febe51 tracing: Add hist trigger timestamp support
Add support for a timestamp event field.  This is actually a 'pseudo-'
event field in that it behaves like it's part of the event record, but
is really part of the corresponding ring buffer event.

To make use of the timestamp field, users can specify
"common_timestamp" as a field name for any histogram.  Note that this
doesn't make much sense on its own either as either a key or value,
but needs to be supported even so, since follow-on patches will add
support for making use of this field in time deltas.  The
common_timestamp 'field' is not a bona fide event field - so you won't
find it in the event description - but rather it's a synthetic field
that can be used like a real field.

Note that the use of this field requires the ring buffer be put into
'absolute timestamp' mode, which saves the complete timestamp for each
event rather than an offset.  This mode will be enabled if and only if
a histogram makes use of the "common_timestamp" field.

Link: http://lkml.kernel.org/r/97afbd646ed146e26271f3458b4b33e16d7817c2.1516069914.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Baohong Liu <baohong.liu@intel.com>
[kasan use-after-free fix]
Signed-off-by: Vedang Patel <vedang.patel@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-03-10 16:05:52 -05:00
Tom Zanussi 9b1ae035c9 tracing: Break out hist trigger assignment parsing
This will make it easier to add variables, and makes the parsing code
cleaner regardless.

Link: http://lkml.kernel.org/r/e574b3291bbe15e35a4dfc87e5395aa715701c98.1516069914.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Rajvi Jingar <rajvi.jingar@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-03-10 16:05:52 -05:00
Tom Zanussi fbd302cbeb tracing: Add ring buffer event param to hist field functions
Some events such as timestamps require access to a ring_buffer_event
struct; add a param so that hist field functions can access that.

Link: http://lkml.kernel.org/r/2ff4af18e72b6002eb86b26b2a7f39cef7d1dfe4.1516069914.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-03-10 16:05:52 -05:00
Tom Zanussi 1ac4f51c0e tracing: Give event triggers access to ring_buffer_event
The ring_buffer event can provide a timestamp that may be useful to
various triggers - pass it into the handlers for that purpose.

Link: http://lkml.kernel.org/r/6de592683b59fa70ffa5d43d0109896623fc1367.1516069914.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-03-10 16:05:51 -05:00
Tom Zanussi 2c1ea60b19 tracing: Add timestamp_mode trace file
Add a new option flag indicating whether or not the ring buffer is in
'absolute timestamp' mode.

Currently this is only set/unset by hist triggers that make use of a
common_timestamp.  As such, there's no reason to make this writeable
for users - its purpose is only to allow users to determine
unequivocally whether or not the ring buffer is in that mode (although
absolute timestamps can coexist with the normal delta timestamps, when
the ring buffer is in absolute mode, timestamps written while absolute
mode is in effect take up more space in the buffer, and are not as
efficient).

Link: http://lkml.kernel.org/r/e8aa7b1cde1cf15014e66545d06ac6ef2ebba456.1516069914.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-03-10 16:05:51 -05:00
Tom Zanussi dc4e2801d4 ring-buffer: Redefine the unimplemented RINGBUF_TYPE_TIME_STAMP
RINGBUF_TYPE_TIME_STAMP is defined but not used, and from what I can
gather was reserved for something like an absolute timestamp feature
for the ring buffer, if not a complete replacement of the current
time_delta scheme.

This code redefines RINGBUF_TYPE_TIME_STAMP to implement absolute time
stamps.  Another way to look at it is that it essentially forces
extended time_deltas for all events.

The motivation for doing this is to enable time_deltas that aren't
dependent on previous events in the ring buffer, making it feasible to
use the ring_buffer_event timetamps in a more random-access way, for
purposes other than serial event printing.

To set/reset this mode, use tracing_set_timestamp_abs() from the
previous interface patch.

Link: http://lkml.kernel.org/r/477b362dba1ce7fab9889a1a8e885a62c472f041.1516069914.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-03-10 16:05:50 -05:00
Tom Zanussi 00b4145298 ring-buffer: Add interface for setting absolute time stamps
Define a new function, tracing_set_time_stamp_abs(), which can be used
to enable or disable the use of absolute timestamps rather than time
deltas for a trace array.

Only the interface is added here; a subsequent patch will add the
underlying implementation.

Link: http://lkml.kernel.org/r/ce96119de44c7fe0ee44786d15254e9b493040d3.1516069914.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Baohong Liu <baohong.liu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-03-10 16:05:50 -05:00
Vedang Patel c193707dde tracing: Remove code which merges duplicates
We now have the logic to detect and remove duplicates in the
tracing_map hash table. The code which merges duplicates in the
histogram is redundant now. So, modify this code just to detect
duplicates. The duplication detection code is still kept to ensure
that any rare race condition which might cause duplicates does not go
unnoticed.

Link: http://lkml.kernel.org/r/55215cf59e2674391bdaf772fdafc4c393352b03.1516069914.git.tom.zanussi@linux.intel.com

Signed-off-by: Vedang Patel <vedang.patel@intel.com>
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-03-10 16:05:49 -05:00
Vedang Patel cbf4100efb tracing: Add support to detect and avoid duplicates
A duplicate in the tracing_map hash table is when 2 different entries
have the same key and, as a result, the key_hash. This is possible due
to a race condition in the algorithm. This race condition is inherent to
the algorithm and not a bug. This was fine because, until now, we were
only interested in the sum of all the values related to a particular
key (the duplicates are dealt with in tracing_map_sort_entries()). But,
with the inclusion of variables[1], we are interested in individual
values. So, it will not be clear what value to choose when
there are duplicates. So, the duplicates need to be removed.

The duplicates can occur in the code in the following scenarios:

- A thread is in the process of adding a new element. It has
successfully executed cmpxchg() and inserted the key. But, it is still
not done acquiring the trace_map_elt struct, populating it and storing
the pointer to the struct in the value field of tracing_map hash table.
If another thread comes in at this time and wants to add an element with
the same key, it will not see the current element and add a new one.

- There are multiple threads trying to execute cmpxchg at the same time,
one of the threads will succeed and the others will fail. The ones which
fail will go ahead increment 'idx' and add a new element there creating
a duplicate.

This patch detects and avoids the first condition by asking the thread
which detects the duplicate to loop one more time. There is also a
possibility of infinite loop if the thread which is trying to insert
goes to sleep indefinitely and the one which is trying to insert a new
element detects a duplicate. Which is why, the thread loops for
map_size iterations before returning NULL.

The second scenario is avoided by preventing the threads which failed
cmpxchg() from incrementing idx. This way, they will loop
around and check if the thread which succeeded in executing cmpxchg()
had the same key.

[1] http://lkml.kernel.org/r/cover.1498510759.git.tom.zanussi@linux.intel.com

Link: http://lkml.kernel.org/r/e178e89ec399240331d383bd5913d649713110f4.1516069914.git.tom.zanussi@linux.intel.com

Signed-off-by: Vedang Patel <vedang.patel@intel.com>
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-03-10 16:05:49 -05:00
Ingo Molnar d88f1f1fdb Merge branch 'linus' into locking/core, to pick up fixes and dependencies
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-10 10:19:28 +01:00
Miroslav Lichvar 78b98e3c5a timekeeping/ntp: Determine the multiplier directly from NTP tick length
When the length of the NTP tick changes significantly, e.g. when an
NTP/PTP application is correcting the initial offset of the clock, a
large value may accumulate in the NTP error before the multiplier
converges to the correct value. It may then take a very long time (hours
or even days) before the error is corrected. This causes the clock to
have an unstable frequency offset, which has a negative impact on the
stability of synchronization with precise time sources (e.g. NTP/PTP
using hardware timestamping or the PTP KVM clock).

Use division to determine the correct multiplier directly from the NTP
tick length and replace the iterative approach. This removes the last
major source of the NTP error. The only remaining source is now limited
resolution of the multiplier, which is corrected by adding 1 to the
multiplier when the system clock is behind the NTP time.

Signed-off-by: Miroslav Lichvar <mlichvar@redhat.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Stephen Boyd <stephen.boyd@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1520620971-9567-3-git-send-email-john.stultz@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-10 09:12:41 +01:00
Miroslav Lichvar c2cda2a5bd timekeeping/ntp: Don't align NTP frequency adjustments to ticks
When the timekeeping multiplier is changed, the NTP error is updated to
correct the clock for the delay between the tick and the update of the
clock. This error is corrected in later updates and the clock appears as
if the frequency was changed exactly on the tick.

Remove this correction to keep the point where the frequency is
effectively changed at the time of the update. This removes a major
source of the NTP error.

Signed-off-by: Miroslav Lichvar <mlichvar@redhat.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Stephen Boyd <stephen.boyd@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1520620971-9567-2-git-send-email-john.stultz@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-10 09:12:41 +01:00
Kees Cook 0862ca422b bug: use %pB in BUG and stack protector failure
The BUG and stack protector reports were still using a raw %p.  This
changes it to %pB for more meaningful output.

Link: http://lkml.kernel.org/r/20180301225704.GA34198@beast
Fixes: ad67b74d24 ("printk: hash addresses printed with %p")
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Richard Weinberger <richard.weinberger@gmail.com>,
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-03-09 16:40:01 -08:00
Dave Martin af40ff687b arm64: signal: Ensure si_code is valid for all fault signals
Currently, as reported by Eric, an invalid si_code value 0 is
passed in many signals delivered to userspace in response to faults
and other kernel errors.  Typically 0 is passed when the fault is
insufficiently diagnosable or when there does not appear to be any
sensible alternative value to choose.

This appears to violate POSIX, and is intuitively wrong for at
least two reasons arising from the fact that 0 == SI_USER:

 1) si_code is a union selector, and SI_USER (and si_code <= 0 in
    general) implies the existence of a different set of fields
    (siginfo._kill) from that which exists for a fault signal
    (siginfo._sigfault).  However, the code raising the signal
    typically writes only the _sigfault fields, and the _kill
    fields make no sense in this case.

    Thus when userspace sees si_code == 0 (SI_USER) it may
    legitimately inspect fields in the inactive union member _kill
    and obtain garbage as a result.

    There appears to be software in the wild relying on this,
    albeit generally only for printing diagnostic messages.

 2) Software that wants to be robust against spurious signals may
    discard signals where si_code == SI_USER (or <= 0), or may
    filter such signals based on the si_uid and si_pid fields of
    siginfo._sigkill.  In the case of fault signals, this means
    that important (and usually fatal) error conditions may be
    silently ignored.

In practice, many of the faults for which arm64 passes si_code == 0
are undiagnosable conditions such as exceptions with syndrome
values in ESR_ELx to which the architecture does not yet assign any
meaning, or conditions indicative of a bug or error in the kernel
or system and thus that are unrecoverable and should never occur in
normal operation.

The approach taken in this patch is to translate all such
undiagnosable or "impossible" synchronous fault conditions to
SIGKILL, since these are at least probably localisable to a single
process.  Some of these conditions should really result in a kernel
panic, but due to the lack of diagnostic information it is
difficult to be certain: this patch does not add any calls to
panic(), but this could change later if justified.

Although si_code will not reach userspace in the case of SIGKILL,
it is still desirable to pass a nonzero value so that the common
siginfo handling code can detect incorrect use of si_code == 0
without false positives.  In this case the si_code dependent
siginfo fields will not be correctly initialised, but since they
are not passed to userspace I deem this not to matter.

A few faults can reasonably occur in realistic userspace scenarios,
and _should_ raise a regular, handleable (but perhaps not
ignorable/blockable) signal: for these, this patch attempts to
choose a suitable standard si_code value for the raised signal in
each case instead of 0.

arm64 was the only arch to define a BUS_FIXME code, so after this
patch nobody defines it.  This patch therefore also removes the
relevant code from siginfo_layout().

Cc: James Morse <james.morse@arm.com>
Reported-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-09 13:58:36 +00:00
Ingo Molnar 82b691bedf softirq: Consolidate common code in tasklet_[hi]_action()
tasklet_action() + tasklet_hi_action() are almost identical.  Move the
common code from both function into __tasklet_action_common() and let
both functions invoke it with different arguments.

[ bigeasy: Splitted out from RT's "tasklet: Prevent tasklets from going
	   into infinite spin in RT" and added commit message]

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Julia Cartwright <juliac@eso.teric.us>
Link: https://lkml.kernel.org/r/20180227164808.10093-3-bigeasy@linutronix.de
2018-03-09 11:50:55 +01:00
Ingo Molnar 6498ddad30 softirq: Consolidate common code in __tasklet_[hi]_schedule()
__tasklet_schedule() and __tasklet_hi_schedule() are almost identical.
Move the common code from both function into __tasklet_schedule_common()
and let both functions invoke it with different arguments.

[ bigeasy: Splitted out from RT's "tasklet: Prevent tasklets from going
  	   into infinite spin in RT" and added commit message. Use
  	   this_cpu_ptr(headp) in __tasklet_schedule_common() as suggested
  	   by Julia Cartwright ]

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Julia Cartwright <juliac@eso.teric.us>
Link: https://lkml.kernel.org/r/20180227164808.10093-2-bigeasy@linutronix.de
2018-03-09 11:50:55 +01:00
Bartosz Golaszewski f09777fa89 genirq/irq_sim: Return the base of the irq range from irq_sim_init()
Returning the base of the allocated interrupt range from irq_sim_init() and
devm_irq_sim_init() allows users to handle the logic of associating irq
numbers with any other driver-specific resources without having to use
irq_sim_irqnum().

Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Link: https://lkml.kernel.org/r/20180304121018.640-4-brgl@bgdev.pl
2018-03-09 11:44:03 +01:00
Bartosz Golaszewski 28b6afa7d4 genirq/irq_sim: Check the return value of irq_sim_init() for error codes
As discussed with Marc Zyngier: irq_sim_init() and its devres variant
should return the base of the allocated interrupt range on success rather
than 0.

Make devm_irq_sim_init() check for an error code. This is a preparatory
change for modifying irq_sim_init() itself.

Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Link: https://lkml.kernel.org/r/20180304121018.640-3-brgl@bgdev.pl
2018-03-09 11:44:03 +01:00
Bartosz Golaszewski 34a866bd45 genirq/irq_sim: Explicitly include slab.h
kfree() is used in the irq_sim code but slab.h is pulled in indirectly via
irq.h. Include it explicitly.

Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Link: https://lkml.kernel.org/r/20180304121018.640-2-brgl@bgdev.pl
2018-03-09 11:44:03 +01:00
Boqun Feng 6b0ef92fee rtmutex: Make rt_mutex_futex_unlock() safe for irq-off callsites
When running rcutorture with TREE03 config, CONFIG_PROVE_LOCKING=y, and
kernel cmdline argument "rcutorture.gp_exp=1", lockdep reports a
HARDIRQ-safe->HARDIRQ-unsafe deadlock:

 ================================
 WARNING: inconsistent lock state
 4.16.0-rc4+ #1 Not tainted
 --------------------------------
 inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage.
 takes:
 __schedule+0xbe/0xaf0
 {IN-HARDIRQ-W} state was registered at:
   _raw_spin_lock+0x2a/0x40
   scheduler_tick+0x47/0xf0
...
 other info that might help us debug this:
  Possible unsafe locking scenario:
        CPU0
        ----
   lock(&rq->lock);
   <Interrupt>
     lock(&rq->lock);
  *** DEADLOCK ***
 1 lock held by rcu_torture_rea/724:
 rcu_torture_read_lock+0x0/0x70
 stack backtrace:
 CPU: 2 PID: 724 Comm: rcu_torture_rea Not tainted 4.16.0-rc4+ #1
 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-20171110_100015-anatol 04/01/2014
 Call Trace:
  lock_acquire+0x90/0x200
  ? __schedule+0xbe/0xaf0
  _raw_spin_lock+0x2a/0x40
  ? __schedule+0xbe/0xaf0
  __schedule+0xbe/0xaf0
  preempt_schedule_irq+0x2f/0x60
  retint_kernel+0x1b/0x2d
 RIP: 0010:rcu_read_unlock_special+0x0/0x680
  ? rcu_torture_read_unlock+0x60/0x60
  __rcu_read_unlock+0x64/0x70
  rcu_torture_read_unlock+0x17/0x60
  rcu_torture_reader+0x275/0x450
  ? rcutorture_booster_init+0x110/0x110
  ? rcu_torture_stall+0x230/0x230
  ? kthread+0x10e/0x130
  kthread+0x10e/0x130
  ? kthread_create_worker_on_cpu+0x70/0x70
  ? call_usermodehelper_exec_async+0x11a/0x150
  ret_from_fork+0x3a/0x50

This happens with the following even sequence:

	preempt_schedule_irq();
	  local_irq_enable();
	  __schedule():
	    local_irq_disable(); // irq off
	    ...
	    rcu_note_context_switch():
	      rcu_note_preempt_context_switch():
	        rcu_read_unlock_special():
	          local_irq_save(flags);
	          ...
		  raw_spin_unlock_irqrestore(...,flags); // irq remains off
	          rt_mutex_futex_unlock():
	            raw_spin_lock_irq();
	            ...
	            raw_spin_unlock_irq(); // accidentally set irq on

	    <return to __schedule()>
	    rq_lock():
	      raw_spin_lock(); // acquiring rq->lock with irq on

which means rq->lock becomes a HARDIRQ-unsafe lock, which can cause
deadlocks in scheduler code.

This problem was introduced by commit 02a7c234e5 ("rcu: Suppress
lockdep false-positive ->boost_mtx complaints"). That brought the user
of rt_mutex_futex_unlock() with irq off.

To fix this, replace the *lock_irq() in rt_mutex_futex_unlock() with
*lock_irq{save,restore}() to make it safe to call rt_mutex_futex_unlock()
with irq off.

Fixes: 02a7c234e5 ("rcu: Suppress lockdep false-positive ->boost_mtx complaints")
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com>
Link: https://lkml.kernel.org/r/20180309065630.8283-1-boqun.feng@gmail.com
2018-03-09 11:06:16 +01:00
Quentin Monnet 6d8cb045cd bpf: comment why dots in filenames under BPF virtual FS are not allowed
When pinning a file under the BPF virtual file system (traditionally
/sys/fs/bpf), using a dot in the name of the location to pin at is not
allowed. For example, trying to pin at "/sys/fs/bpf/foo.bar" will be
rejected with -EPERM.

This check was introduced at the same time as the BPF file system
itself, with commit b2197755b2 ("bpf: add support for persistent
maps/progs"). At this time, it was checked in a function called
"bpf_dname_reserved()", which made clear that using a dot was reserved
for future extensions.

This function disappeared and the check was moved elsewhere with commit
0c93b7d85d ("bpf: reject invalid names right in ->lookup()"), and the
meaning of the dot ban was lost.

The present commit simply adds a comment in the source to explain to the
reader that the usage of dots is reserved for future usage.

Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-03-09 10:30:30 +01:00
Song Liu bd903afeb5 perf/core: Fix ctx_event_type in ctx_resched()
In ctx_resched(), EVENT_FLEXIBLE should be sched_out when EVENT_PINNED is
added. However, ctx_resched() calculates ctx_event_type before checking
this condition. As a result, pinned events will NOT get higher priority
than flexible events.

The following shows this issue on an Intel CPU (where ref-cycles can
only use one hardware counter).

  1. First start:
       perf stat -C 0 -e ref-cycles  -I 1000
  2. Then, in the second console, run:
       perf stat -C 0 -e ref-cycles:D -I 1000

The second perf uses pinned events, which is expected to have higher
priority. However, because it failed in ctx_resched(). It is never
run.

This patch fixes this by calculating ctx_event_type after re-evaluating
event_type.

Reported-by: Ephraim Park <ephiepark@fb.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <jolsa@redhat.com>
Cc: <kernel-team@fb.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Fixes: 487f05e18a ("perf/core: Optimize event rescheduling on active contexts")
Link: http://lkml.kernel.org/r/20180306055504.3283731-1-songliubraving@fb.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-09 08:03:02 +01:00
gaurav jindal d17067e448 sched/completions: Use bool in try_wait_for_completion()
Since the return type of the function is bool, the internal
'ret' variable should be bool too.

Signed-off-by: Gaurav Jindal<gauravjindal1104@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20180221125407.GA14292@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-09 08:00:18 +01:00
Vincent Guittot 31e77c93e4 sched/fair: Update blocked load when newly idle
When NEWLY_IDLE load balance is not triggered, we might need to update the
blocked load anyway. We can kick an ilb so an idle CPU will take care of
updating blocked load or we can try to update them locally before entering
idle. In the latter case, we reuse part of the nohz_idle_balance.

Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: brendan.jackman@arm.com
Cc: dietmar.eggemann@arm.com
Cc: morten.rasmussen@foss.arm.com
Cc: valentin.schneider@arm.com
Link: http://lkml.kernel.org/r/1518622006-16089-4-git-send-email-vincent.guittot@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-09 07:59:28 +01:00
Peter Zijlstra 47ea54121e sched/fair: Move idle_balance()
We're going to want to call nohz_idle_balance() or parts thereof from
idle_balance(). Since we already have a forward declaration of
idle_balance() move it down such that it's below nohz_idle_balance()
avoiding the need for a forward declaration for that.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-09 07:59:25 +01:00
Peter Zijlstra dd707247ab sched/nohz: Merge CONFIG_NO_HZ_COMMON blocks
Now that we have two back-to-back NO_HZ_COMMON blocks, merge them.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-09 07:59:24 +01:00
Peter Zijlstra af3fe03c56 sched/fair: Move rebalance_domains()
This pure code movement results in two #ifdef CONFIG_NO_HZ_COMMON
sections landing next to each other.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-09 07:59:23 +01:00
Peter Zijlstra 63928384fa sched/nohz: Optimize nohz_idle_balance()
Avoid calling update_blocked_averages() when it does not in fact have
any by re-using/extending update_nohz_stats().

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-09 07:59:22 +01:00
Vincent Guittot 1936c53ce8 sched/fair: Reduce the periodic update duration
Instead of using the cfs_rq_is_decayed() which monitors all *_avg
and *_sum, we create a cfs_rq_has_blocked() which only takes care of
util_avg and load_avg. We are only interested by these 2 values which are
decaying faster than the *_sum so we can stop the periodic update earlier.

Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: brendan.jackman@arm.com
Cc: dietmar.eggemann@arm.com
Cc: morten.rasmussen@foss.arm.com
Cc: valentin.schneider@arm.com
Link: http://lkml.kernel.org/r/1518517879-2280-3-git-send-email-vincent.guittot@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-09 07:59:22 +01:00
Vincent Guittot f643ea2207 sched/nohz: Stop NOHZ stats when decayed
Stopped the periodic update of blocked load when all idle CPUs have fully
decayed. We introduce a new nohz.has_blocked that reflect if some idle
CPUs has blocked load that have to be periodiccally updated. nohz.has_blocked
is set everytime that a Idle CPU can have blocked load and it is then clear
when no more blocked load has been detected during an update. We don't need
atomic operation but only to make cure of the right ordering when updating
nohz.idle_cpus_mask and nohz.has_blocked.

Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: brendan.jackman@arm.com
Cc: dietmar.eggemann@arm.com
Cc: morten.rasmussen@foss.arm.com
Cc: valentin.schneider@arm.com
Link: http://lkml.kernel.org/r/1518517879-2280-2-git-send-email-vincent.guittot@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-09 07:59:21 +01:00
Peter Zijlstra ea14b57e8a sched/cpufreq: Provide migration hint
It was suggested that a migration hint might be usefull for the
CPU-freq governors.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Juri Lelli <juri.lelli@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-09 07:59:20 +01:00
Peter Zijlstra 00357f5ec5 sched/nohz: Clean up nohz enter/exit
The primary observation is that nohz enter/exit is always from the
current CPU, therefore NOHZ_TICK_STOPPED does not in fact need to be
an atomic.

Secondary is that we appear to have 2 nearly identical hooks in the
nohz enter code, set_cpu_sd_state_idle() and
nohz_balance_enter_idle(). Fold the whole set_cpu_sd_state thing into
nohz_balance_{enter,exit}_idle.

Removes an atomic op from both enter and exit paths.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-09 07:59:19 +01:00
Peter Zijlstra e022e0d38a sched/fair: Update blocked load from NEWIDLE
Since we already iterate CPUs looking for work on NEWIDLE, use this
iteration to age the blocked load. If the domain for which this is
done completely spand the idle set, we can push the ILB based aging
forward.

Suggested-by: Brendan Jackman <brendan.jackman@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-09 07:59:19 +01:00
Peter Zijlstra a4064fb614 sched/fair: Add NOHZ stats balancing
Teach the idle balancer about the need to update statistics which have
a different periodicity from regular balancing.

Suggested-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-09 07:59:18 +01:00
Peter Zijlstra 4550487a99 sched/fair: Restructure nohz_balance_kick()
The current:

	if (nohz_kick_needed())
		nohz_balancer_kick()

is pointless complexity, fold them into a single call and avoid the
various conditions at the call site.

When we introduce multiple different needs to kick the ilb, the above
construct also becomes a problem.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-09 07:59:17 +01:00
Peter Zijlstra b7031a02ec sched/fair: Add NOHZ_STATS_KICK
Split the NOHZ idle balancer into doing two separate actions:

 - update blocked load statistic

 - actually load-balance

Since the latter requires the former, ensure this happens. For now
always tag both bits at the same time.

Prepares for a future where we can toggle only the STATS bit.

Suggested-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-09 07:59:16 +01:00
Peter Zijlstra a22e47a4e3 sched/core: Convert nohz_flags to atomic_t
Using atomic_t allows us to use the more flexible bitops provided
there. Also its smaller.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-09 07:59:16 +01:00
Peter Zijlstra 8f111bc357 cpufreq/schedutil: Rewrite CPUFREQ_RT support
Instead of trying to duplicate scheduler state to track if an RT task
is running, directly use the scheduler runqueue state for it.

This vastly simplifies things and fixes a number of bugs related to
sugov and the scheduler getting out of sync wrt this state.

As a consequence we not also update the remove cfs/dl state when
iterating the shared mask.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Juri Lelli <juri.lelli@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-09 07:59:15 +01:00
Peter Zijlstra 4042d003a0 cpufreq/schedutil: Remove unused CPUFREQ_DL
Bitrot...

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Juri Lelli <juri.lelli@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-09 07:59:14 +01:00
Norbert Manthey 13a453c241 sched/fair: Add ';' after label attributes
Due to using GCC defines for configuration, some labels might be unused in
certain configurations. While adding a __maybe_unused to the label is
fine in general, the line has to be terminated with ';'. This is also
reflected in the GCC documentation, but GCC parsed the previous variant
without an error message.

This has been spotted while compiling with goto-cc, the compiler for the
CPROVER tool suite.

Signed-off-by: Norbert Manthey <nmanthey@amazon.de>
Signed-off-by: Michael Tautschnig <tautschn@amazon.co.uk>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1519717660-16157-1-git-send-email-nmanthey@amazon.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-09 07:59:13 +01:00
Ingo Molnar fc4c5a3828 Merge branch 'linus' into sched/core, to pick up fixes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-09 07:32:20 +01:00
Richard Guy Briggs 45b578fe4c audit: link denied should not directly generate PATH record
Audit link denied events generate duplicate PATH records which disagree
in different ways from symlink and hardlink denials.
audit_log_link_denied() should not directly generate PATH records.

See: https://github.com/linux-audit/audit-kernel/issues/21

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2018-03-08 19:25:35 -05:00
Richard Guy Briggs 15564ff0a1 audit: make ANOM_LINK obey audit_enabled and audit_dummy_context
Audit link denied events emit disjointed records when audit is disabled.
No records should be emitted when audit is disabled.

See: https://github.com/linux-audit/audit-kernel/issues/21

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2018-03-08 19:19:54 -05:00
Leon Yu 3f553b308b module: propagate error in modules_open()
otherwise kernel can oops later in seq_release() due to dereferencing null
file->private_data which is only set if seq_open() succeeds.

BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
IP: seq_release+0xc/0x30
Call Trace:
 close_pdeo+0x37/0xd0
 proc_reg_release+0x5d/0x60
 __fput+0x9d/0x1d0
 ____fput+0x9/0x10
 task_work_run+0x75/0x90
 do_exit+0x252/0xa00
 do_group_exit+0x36/0xb0
 SyS_exit_group+0xf/0x10

Fixes: 516fb7f2e7 ("/proc/module: use the same logic as /proc/kallsyms for address exposure")
Cc: Jessica Yu <jeyu@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: stable@vger.kernel.org # 4.15+
Signed-off-by: Leon Yu <chianglungyu@gmail.com>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
2018-03-08 21:58:51 +01:00
Linus Torvalds e67548254b MIPS fixes for 4.16-rc5
A miscellaneous pile of MIPS fixes for 4.16:
  - Move put_compat_sigset() to evade hardened usercopy warnings (4.16)
  - Select ARCH_HAVE_PC_{SERIO,PARPORT} for Loongson64 platforms (4.16)
  - Fix kzalloc() failure handling in ath25 (3.19) and Octeon (4.0)
  - Fix disabling of IPIs during BMIPS suspend (3.19)
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Merge tag 'mips_fixes_4.16_4' of git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/mips

Pull MIPS fixes from James Hogan:
 "A miscellaneous pile of MIPS fixes for 4.16:

   - move put_compat_sigset() to evade hardened usercopy warnings (4.16)

   - select ARCH_HAVE_PC_{SERIO,PARPORT} for Loongson64 platforms (4.16)

   - fix kzalloc() failure handling in ath25 (3.19) and Octeon (4.0)

   - fix disabling of IPIs during BMIPS suspend (3.19)"

* tag 'mips_fixes_4.16_4' of git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/mips:
  MIPS: BMIPS: Do not mask IPIs during suspend
  MIPS: Loongson64: Select ARCH_MIGHT_HAVE_PC_SERIO
  MIPS: Loongson64: Select ARCH_MIGHT_HAVE_PC_PARPORT
  signals: Move put_compat_sigset to compat.h to silence hardened usercopy
  MIPS: OCTEON: irq: Check for null return on kzalloc allocation
  MIPS: ath25: Check for kzalloc allocation failure
2018-03-08 10:03:12 -08:00
Borislav Petkov 5ad7510537 panic: Add closing panic marker parenthesis
Otherwise it looks unbalanced.

Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Link: https://lkml.kernel.org/r/20180306094920.16917-2-bp@alien8.de
2018-03-08 12:01:10 +01:00
Teng Qin 95da0cdb72 bpf: add support to read sample address in bpf program
This commit adds new field "addr" to bpf_perf_event_data which could be
read and used by bpf programs attached to perf events. The value of the
field is copied from bpf_perf_event_data_kern.addr and contains the
address value recorded by specifying sample_type with PERF_SAMPLE_ADDR
when calling perf_event_open.

Signed-off-by: Teng Qin <qinteng@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-03-08 02:22:34 +01:00
Stephen Smalley 6b4f3d0105 usb, signal, security: only pass the cred, not the secid, to kill_pid_info_as_cred and security_task_kill
commit d178bc3a70 ("user namespace: usb:
 make usb urbs user namespace aware (v2)") changed kill_pid_info_as_uid
to kill_pid_info_as_cred, saving and passing a cred structure instead of
uids.  Since the secid can be obtained from the cred, drop the secid fields
from the usb_dev_state and async structures, and drop the secid argument to
kill_pid_info_as_cred.  Replace the secid argument to security_task_kill
with the cred.  Update SELinux, Smack, and AppArmor to use the cred, which
avoids the need for Smack and AppArmor to use a secid at all in this hook.
Further changes to Smack might still be required to take full advantage of
this change, since it should now be possible to perform capability
checking based on the supplied cred.  The changes to Smack and AppArmor
have only been compile-tested.

Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: Paul Moore <paul@paul-moore.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: James Morris <james.morris@microsoft.com>
2018-03-07 09:05:53 +11:00
Oliver O'Halloran 167f5594b5 kernel/memremap: Remove stale devres_free() call
devm_memremap_pages() was re-worked in e8d5134833 "memremap: change
devm_memremap_pages interface to use struct dev_pagemap" to take a
caller allocated struct dev_pagemap as a function parameter. A call to
devres_free() was left in the error cleanup path which results in a
kernel panic if the remap fails for some reason. Remove it to fix the
panic and let devm_memremap_pages() fail gracefully.

Fixes: e8d5134833 ("memremap: change devm_memremap_pages interface...")
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2018-03-06 10:58:54 -08:00
Greg Edwards 11dd266637 audit: do not panic on invalid boot parameter
If you pass in an invalid audit boot parameter value, e.g. "audit=off",
the kernel panics very early in boot before the regular console is
initialized.  Unless you have earlyprintk enabled, there is no
indication of what the problem is on the console.

Convert the panic() calls to pr_err(), and leave auditing enabled if an
invalid parameter value was passed in.

Modify the parameter to also accept "on" or "off" as valid values, and
update the documentation accordingly.

Signed-off-by: Greg Edwards <gedwards@ddn.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2018-03-06 13:50:07 -05:00
Ingo Molnar 8af31363cd Linux 4.16-rc4
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Merge tag 'v4.16-rc4' into perf/core, to pick up fixes

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-06 07:30:22 +01:00
David S. Miller 0f3e9c97eb Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
All of the conflicts were cases of overlapping changes.

In net/core/devlink.c, we have to make care that the
resouce size_params have become a struct member rather
than a pointer to such an object.

Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-06 01:20:46 -05:00
Linus Torvalds 547046141f Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Pull networking fixes from David Miller:

 1) Use an appropriate TSQ pacing shift in mac80211, from Toke
    Høiland-Jørgensen.

 2) Just like ipv4's ip_route_me_harder(), we have to use skb_to_full_sk
    in ip6_route_me_harder, from Eric Dumazet.

 3) Fix several shutdown races and similar other problems in l2tp, from
    James Chapman.

 4) Handle missing XDP flush properly in tuntap, for real this time.
    From Jason Wang.

 5) Out-of-bounds access in powerpc ebpf tailcalls, from Daniel
    Borkmann.

 6) Fix phy_resume() locking, from Andrew Lunn.

 7) IFLA_MTU values are ignored on newlink for some tunnel types, fix
    from Xin Long.

 8) Revert F-RTO middle box workarounds, they only handle one dimension
    of the problem. From Yuchung Cheng.

 9) Fix socket refcounting in RDS, from Ka-Cheong Poon.

10) Don't allow ppp unit registration to an unregistered channel, from
    Guillaume Nault.

11) Various hv_netvsc fixes from Stephen Hemminger.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (98 commits)
  hv_netvsc: propagate rx filters to VF
  hv_netvsc: filter multicast/broadcast
  hv_netvsc: defer queue selection to VF
  hv_netvsc: use napi_schedule_irqoff
  hv_netvsc: fix race in napi poll when rescheduling
  hv_netvsc: cancel subchannel setup before halting device
  hv_netvsc: fix error unwind handling if vmbus_open fails
  hv_netvsc: only wake transmit queue if link is up
  hv_netvsc: avoid retry on send during shutdown
  virtio-net: re enable XDP_REDIRECT for mergeable buffer
  ppp: prevent unregistered channels from connecting to PPP units
  tc-testing: skbmod: fix match value of ethertype
  mlxsw: spectrum_switchdev: Check success of FDB add operation
  net: make skb_gso_*_seglen functions private
  net: xfrm: use skb_gso_validate_network_len() to check gso sizes
  net: sched: tbf: handle GSO_BY_FRAGS case in enqueue
  net: rename skb_gso_validate_mtu -> skb_gso_validate_network_len
  rds: Incorrect reference counting in TCP socket creation
  net: ethtool: don't ignore return from driver get_fecparam method
  vrf: check forwarding on the original netdevice when generating ICMP dest unreachable
  ...
2018-03-05 11:29:24 -08:00
Linus Torvalds 4c4ce3022d Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer fixes from Thomas Gleixner:
 "A small set of fixes from the timer departement:

   - Add a missing timer wheel clock forward when migrating timers off a
     unplugged CPU to prevent operating on a stale clock base and
     missing timer deadlines.

   - Use the proper shift count to extract data from a register value to
     prevent evaluating unrelated bits

   - Make the error return check in the FSL timer driver work correctly.
     Checking an unsigned variable for less than zero does not really
     work well.

   - Clarify the confusing comments in the ARC timer code"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  timers: Forward timer base before migrating timers
  clocksource/drivers/arc_timer: Update some comments
  clocksource/drivers/mips-gic-timer: Use correct shift count to extract data
  clocksource/drivers/fsl_ftm_timer: Fix error return checking
2018-03-04 11:34:49 -08:00
Ingo Molnar 14a7405b2e sched/core: Undefine tracepoint creation at the end of core.c
Make it easier to concatenate all the scheduler .c files for single-module
compilation.

Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-04 12:39:34 +01:00
Ingo Molnar 02d8ec9456 sched/deadline, rt: Rename queue_push_tasks/queue_pull_task to create separate namespace
There are similarly named functions in both of these modules:

  kernel/sched/deadline.c:static inline void queue_push_tasks(struct rq *rq)
  kernel/sched/deadline.c:static inline void queue_pull_task(struct rq *rq)
  kernel/sched/deadline.c:static inline void queue_push_tasks(struct rq *rq)
  kernel/sched/deadline.c:static inline void queue_pull_task(struct rq *rq)
  kernel/sched/deadline.c:	queue_push_tasks(rq);
  kernel/sched/deadline.c:	queue_pull_task(rq);
  kernel/sched/deadline.c:			queue_push_tasks(rq);
  kernel/sched/deadline.c:			queue_pull_task(rq);
  kernel/sched/rt.c:static inline void queue_push_tasks(struct rq *rq)
  kernel/sched/rt.c:static inline void queue_pull_task(struct rq *rq)
  kernel/sched/rt.c:static inline void queue_push_tasks(struct rq *rq)
  kernel/sched/rt.c:	queue_push_tasks(rq);
  kernel/sched/rt.c:	queue_pull_task(rq);
  kernel/sched/rt.c:			queue_push_tasks(rq);
  kernel/sched/rt.c:			queue_pull_task(rq);

... which makes it harder to grep for them. Prefix them with
deadline_ and rt_, respectively.

Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-04 12:39:34 +01:00
Ingo Molnar a92057e14b sched/idle: Merge kernel/sched/idle.c and kernel/sched/idle_task.c
Merge these two small .c modules as they implement two aspects
of idle task handling.

Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-04 12:39:33 +01:00
Ingo Molnar 325ea10c08 sched/headers: Simplify and clean up header usage in the scheduler
Do the following cleanups and simplifications:

 - sched/sched.h already includes <asm/paravirt.h>, so no need to
   include it in sched/core.c again.

 - order the <linux/sched/*.h> headers alphabetically

 - add all <linux/sched/*.h> headers to kernel/sched/sched.h

 - remove all unnecessary includes from the .c files that
   are already included in kernel/sched/sched.h.

Finally, make all scheduler .c files use a single common header:

  #include "sched.h"

... which now contains a union of the relied upon headers.

This makes the various .c files easier to read and easier to handle.

Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-04 12:39:29 +01:00
Linus Torvalds 20f14172cb Merge branch 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm
Pull libnvdimm fixes from Dan Williams:
 "A 4.16 regression fix, three fixes for -stable, and a cleanup fix:

   - During the merge window support for the new ACPI NVDIMM Platform
     Capabilities structure disabled support for "deep flush", a
     force-unit- access like mechanism for persistent memory. Restore
     that mechanism.

   - VFIO like RDMA is yet one more memory registration / pinning
     interface that is incompatible with Filesystem-DAX. Disable long
     term pins of Filesystem-DAX mappings via VFIO.

   - The Filesystem-DAX detection to prevent long terms pins mistakenly
     also disabled Device-DAX pins which are not subject to the same
     block- map collision concerns.

   - Similar to the setup path, softlockup warnings can trigger in the
     shutdown path for large persistent memory namespaces. Teach
     for_each_device_pfn() to perform cond_resched() in all cases.

   - Boaz noticed that the might_sleep() in dax_direct_access() is stale
     as of the v4.15 kernel.

  These have received a build success notification from the 0day robot,
  and the longterm pin fixes have appeared in -next. However, I recently
  rebased the tree to remove some other fixes that need to be reworked
  after review feedback.

* 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  memremap: fix softlockup reports at teardown
  libnvdimm: re-enable deep flush for pmem devices via fsync()
  vfio: disable filesystem-dax page pinning
  dax: fix vma_is_fsdax() helper
  dax: ->direct_access does not sleep anymore
2018-03-03 14:32:00 -08:00
Ingo Molnar 97fb7a0a89 sched: Clean up and harmonize the coding style of the scheduler code base
A good number of small style inconsistencies have accumulated
in the scheduler core, so do a pass over them to harmonize
all these details:

 - fix speling in comments,

 - use curly braces for multi-line statements,

 - remove unnecessary parentheses from integer literals,

 - capitalize consistently,

 - remove stray newlines,

 - add comments where necessary,

 - remove invalid/unnecessary comments,

 - align structure definitions and other data types vertically,

 - add missing newlines for increased readability,

 - fix vertical tabulation where it's misaligned,

 - harmonize preprocessor conditional block labeling
   and vertical alignment,

 - remove line-breaks where they uglify the code,

 - add newline after local variable definitions,

No change in functionality:

  md5:
     1191fa0a890cfa8132156d2959d7e9e2  built-in.o.before.asm
     1191fa0a890cfa8132156d2959d7e9e2  built-in.o.after.asm

Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-03 15:50:21 +01:00
Mario Leinweber c2e513821d sched/deadline: Clean up various coding style details
- Fixed style error: Missing space before the open parenthesis
- Fixed style warnings: 2x Missing blank line after declaration

One warning left: else after return
 (I don't feel comfortable fixing that without side effects)

Signed-off-by: Mario Leinweber <marioleinweber@web.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/20180302182007.28691-1-marioleinweber@web.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-03 15:50:20 +01:00
Dan Williams 949b93250a memremap: fix softlockup reports at teardown
The cond_resched() currently in the setup path needs to be duplicated in
the teardown path. Rather than require each instance of
for_each_device_pfn() to open code the same sequence, embed it in the
helper.

Link: https://github.com/intel/ixpdimm_sw/issues/11
Cc: "Jérôme Glisse" <jglisse@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: <stable@vger.kernel.org>
Fixes: 7138970383 ("mm, zone_device: Replace {get, put}_zone_device_page()...")
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2018-03-02 19:34:50 -08:00
Matt Redfearn fde9fc766e
signals: Move put_compat_sigset to compat.h to silence hardened usercopy
Since commit afcc90f862 ("usercopy: WARN() on slab cache usercopy
region violations"), MIPS systems booting with a compat root filesystem
emit a warning when copying compat siginfo to userspace:

WARNING: CPU: 0 PID: 953 at mm/usercopy.c:81 usercopy_warn+0x98/0xe8
Bad or missing usercopy whitelist? Kernel memory exposure attempt
detected from SLAB object 'task_struct' (offset 1432, size 16)!
Modules linked in:
CPU: 0 PID: 953 Comm: S01logging Not tainted 4.16.0-rc2 #10
Stack : ffffffff808c0000 0000000000000000 0000000000000001 65ac85163f3bdc4a
	65ac85163f3bdc4a 0000000000000000 90000000ff667ab8 ffffffff808c0000
	00000000000003f8 ffffffff808d0000 00000000000000d1 0000000000000000
	000000000000003c 0000000000000000 ffffffff808c8ca8 ffffffff808d0000
	ffffffff808d0000 ffffffff80810000 fffffc0000000000 ffffffff80785c30
	0000000000000009 0000000000000051 90000000ff667eb0 90000000ff667db0
	000000007fe0d938 0000000000000018 ffffffff80449958 0000000020052798
	ffffffff808c0000 90000000ff664000 90000000ff667ab0 00000000100c0000
	ffffffff80698810 0000000000000000 0000000000000000 0000000000000000
	0000000000000000 0000000000000000 ffffffff8010d02c 65ac85163f3bdc4a
	...
Call Trace:
[<ffffffff8010d02c>] show_stack+0x9c/0x130
[<ffffffff80698810>] dump_stack+0x90/0xd0
[<ffffffff80137b78>] __warn+0x100/0x118
[<ffffffff80137bdc>] warn_slowpath_fmt+0x4c/0x70
[<ffffffff8021e4a8>] usercopy_warn+0x98/0xe8
[<ffffffff8021e68c>] __check_object_size+0xfc/0x250
[<ffffffff801bbfb8>] put_compat_sigset+0x30/0x88
[<ffffffff8011af24>] setup_rt_frame_n32+0xc4/0x160
[<ffffffff8010b8b4>] do_signal+0x19c/0x230
[<ffffffff8010c408>] do_notify_resume+0x60/0x78
[<ffffffff80106f50>] work_notifysig+0x10/0x18
---[ end trace 88fffbf69147f48a ]---

Commit 5905429ad8 ("fork: Provide usercopy whitelisting for
task_struct") noted that:

"While the blocked and saved_sigmask fields of task_struct are copied to
userspace (via sigmask_to_save() and setup_rt_frame()), it is always
copied with a static length (i.e. sizeof(sigset_t))."

However, this is not true in the case of compat signals, whose sigset
is copied by put_compat_sigset and receives size as an argument.

At most call sites, put_compat_sigset is copying a sigset from the
current task_struct. This triggers a warning when
CONFIG_HARDENED_USERCOPY is active. However, by marking this function as
static inline, the warning can be avoided because in all of these cases
the size is constant at compile time, which is allowed. The only site
where this is not the case is handling the rt_sigpending syscall, but
there the copy is being made from a stack local variable so does not
trigger the warning.

Move put_compat_sigset to compat.h, and mark it static inline. This
fixes the WARN on MIPS.

Fixes: afcc90f862 ("usercopy: WARN() on slab cache usercopy region violations")
Signed-off-by: Matt Redfearn <matt.redfearn@mips.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: "Dmitry V . Levin" <ldv@altlinux.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: kernel-hardening@lists.openwall.com
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/18639/
Signed-off-by: James Hogan <jhogan@kernel.org>
2018-03-02 21:31:55 +00:00
David S. Miller a5f7b0eeb2 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Daniel Borkmann says:

====================
pull-request: bpf 2018-02-28

The following pull-request contains BPF updates for your *net* tree.

The main changes are:

1) Add schedule points and reduce the number of loop iterations
   the test_bpf kernel module is performing in order to not hog
   the CPU for too long, from Eric.

2) Fix an out of bounds access in tail calls in the ppc64 BPF
   JIT compiler, from Daniel.

3) Fix a crash on arm64 on unaligned BPF xadd operations that
   could be triggered via interpreter and JIT, from Daniel.

Please not that once you merge net into net-next at some point, there
is a minor merge conflict in test_verifier.c since test cases had
been added at the end in both trees. Resolution is trivial: keep all
the test cases from both trees.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-01 21:42:07 -05:00
Linus Torvalds 7bec4a9646 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk
Pull printk fix from Petr Mladek:
 "Make sure that we wake up userspace loggers. This fixes a race
  introduced by the console waiter logic during this merge window"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk:
  printk: Wake klogd when passing console_lock owner
2018-03-01 10:06:39 -08:00
Lingutla Chandrasekhar c52232a49e timers: Forward timer base before migrating timers
On CPU hotunplug the enqueued timers of the unplugged CPU are migrated to a
live CPU. This happens from the control thread which initiated the unplug.

If the CPU on which the control thread runs came out from a longer idle
period then the base clock of that CPU might be stale because the control
thread runs prior to any event which forwards the clock.

In such a case the timers from the unplugged CPU are queued on the live CPU
based on the stale clock which can cause large delays due to increased
granularity of the outer timer wheels which are far away from base:;clock.

But there is a worse problem than that. The following sequence of events
illustrates it:

 - CPU0 timer1 is queued expires = 59969 and base->clk = 59131.

   The timer is queued at wheel level 2, with resulting expiry time = 60032
   (due to level granularity).

 - CPU1 enters idle @60007, with next timer expiry @60020.

 - CPU0 is hotplugged at @60009

 - CPU1 exits idle and runs the control thread which migrates the
   timers from CPU0

   timer1 is now queued in level 0 for immediate handling in the next
   softirq because the requested expiry time 59969 is before CPU1 base->clk
   60007

 - CPU1 runs code which forwards the base clock which succeeds because the
   next expiring timer. which was collected at idle entry time is still set
   to 60020.

   So it forwards beyond 60007 and therefore misses to expire the migrated
   timer1. That timer gets expired when the wheel wraps around again, which
   takes between 63 and 630ms depending on the HZ setting.

Address both problems by invoking forward_timer_base() for the control CPUs
timer base. All other places, which might run into a similar problem
(mod_timer()/add_timer_on()) already invoke forward_timer_base() to avoid
that.

[ tglx: Massaged comment and changelog ]

Fixes: a683f390b9 ("timers: Forward the wheel clock whenever possible")
Co-developed-by: Neeraj Upadhyay <neeraju@codeaurora.org>
Signed-off-by: Neeraj Upadhyay <neeraju@codeaurora.org>
Signed-off-by: Lingutla Chandrasekhar <clingutla@codeaurora.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Anna-Maria Gleixner <anna-maria@linutronix.de>
Cc: linux-arm-msm@vger.kernel.org
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20180118115022.6368-1-clingutla@codeaurora.org
2018-02-28 23:34:33 +01:00
Andy Shevchenko d61e2944b6 genirq: Add wakeup sysfs node to show IRQ wakeup state
Surprisingly there is no simple way to see if the IRQ line in question
is wakeup source or not.

Note that wakeup might be an OOB (out-of-band) source like GPIO line
which makes things slightly more complicated.

Add a sysfs node to cover this case.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Tony Lindgren <tony@atomide.com>
Cc: Grygorii Strashko <grygorii.strashko@ti.com>
Cc: "Rafael J . Wysocki" <rafael.j.wysocki@intel.com>
Link: https://lkml.kernel.org/r/20180226155043.67937-1-andriy.shevchenko@linux.intel.com
2018-02-28 18:07:20 +01:00
Borislav Petkov 04860d48a8 locking/lockdep: Show unadorned pointers
Show unadorned pointers in lockdep reports - lockdep is a debugging
facility and hashing pointers there doesn't make a whole lotta sense.

Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20180226134926.23069-1-bp@alien8.de
2018-02-28 15:25:44 +01:00
Baolin Wang 27263e8dc0 clocksource: Use ATTRIBUTE_GROUPS
Use ATTRIBUTE_GROUPS instead of manually creating the individual device
files.

Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: arnd@arndb.de
Cc: sboyd@codeaurora.org
Cc: broonie@kernel.org
Cc: john.stultz@linaro.org
Link: https://lkml.kernel.org/r/d80dccb981dc2461781ebb8d71a32ccdc1b0e6f9.1516167691.git.baolin.wang@linaro.org
2018-02-28 14:05:07 +01:00
Baolin Wang e87821d18c clocksource: Use DEVICE_ATTR_RW/RO/WO to define device attributes
Convert DEVICE_ATTR to DEVICE_ATTR_RW/RO/WO which is the preferred and
simpler way of implementation.

Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: arnd@arndb.de
Cc: sboyd@codeaurora.org
Cc: broonie@kernel.org
Cc: john.stultz@linaro.org
Link: https://lkml.kernel.org/r/8f35c77e753e957b61187e8e7b2e4a3d61e4a72b.1516167691.git.baolin.wang@linaro.org
2018-02-28 14:04:52 +01:00
Baolin Wang 7f852afe44 clocksource: Don't walk the clocksource list for empty override
If the override clocksource name is empty there is no point in walking the
clocksource list for a match.

Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: arnd@arndb.de
Cc: sboyd@codeaurora.org
Cc: broonie@kernel.org
Cc: john.stultz@linaro.org
Link: https://lkml.kernel.org/r/069ce2a605546bcad6552968cff755f0a03f9f10.1516167691.git.baolin.wang@linaro.org
2018-02-28 14:04:52 +01:00
Petr Mladek c14376de3a printk: Wake klogd when passing console_lock owner
wake_klogd is a local variable in console_unlock(). The information
is lost when the console_lock owner using the busy wait added by
the commit dbdda842fe ("printk: Add console owner and waiter
logic to load balance console writes"). The following race is
possible:

CPU0				CPU1
console_unlock()

  for (;;)
     /* calling console for last message */

				printk()
				  log_store()
				    log_next_seq++;

     /* see new message */
     if (seen_seq != log_next_seq) {
	wake_klogd = true;
	seen_seq = log_next_seq;
     }

     console_lock_spinning_enable();

				  if (console_trylock_spinning())
				     /* spinning */

     if (console_lock_spinning_disable_and_check()) {
	printk_safe_exit_irqrestore(flags);
	return;

				  console_unlock()
				    if (seen_seq != log_next_seq) {
				    /* already seen */
				    /* nothing to do */

Result: Nobody would wakeup klogd.

One solution would be to make a global variable from wake_klogd.
But then we would need to manipulate it under a lock or so.

This patch wakes klogd also when console_lock is passed to the
spinning waiter. It looks like the right way to go. Also userspace
should have a chance to see and store any "flood" of messages.

Note that the very late klogd wake up was a historic solution.
It made sense on single CPU systems or when sys_syslog() operations
were synchronized using the big kernel lock like in v2.1.113.
But it is questionable these days.

Fixes: dbdda842fe ("printk: Add console owner and waiter logic to load balance console writes")
Link: http://lkml.kernel.org/r/20180226155734.dzwg3aovqnwtvkoy@pathway.suse.cz
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: linux-kernel@vger.kernel.org
Cc: Tejun Heo <tj@kernel.org>
Suggested-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
2018-02-27 10:25:50 +01:00
Linus Torvalds 85a2d939c0 Merge branch 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Thomas Gleixner:
 "Yet another pile of melted spectrum related changes:

   - sanitize the array_index_nospec protection mechanism: Remove the
     overengineered array_index_nospec_mask_check() magic and allow
     const-qualified types as index to avoid temporary storage in a
     non-const local variable.

   - make the microcode loader more robust by properly propagating error
     codes. Provide information about new feature bits after micro code
     was updated so administrators can act upon.

   - optimizations of the entry ASM code which reduce code footprint and
     make the code simpler and faster.

   - fix the {pmd,pud}_{set,clear}_flags() implementations to work
     properly on paravirt kernels by removing the address translation
     operations.

   - revert the harmful vmexit_fill_RSB() optimization

   - use IBRS around firmware calls

   - teach objtool about retpolines and add annotations for indirect
     jumps and calls.

   - explicitly disable jumplabel patching in __init code and handle
     patching failures properly instead of silently ignoring them.

   - remove indirect paravirt calls for writing the speculation control
     MSR as these calls are obviously proving the same attack vector
     which is tried to be mitigated.

   - a few small fixes which address build issues with recent compiler
     and assembler versions"

* 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (38 commits)
  KVM/VMX: Optimize vmx_vcpu_run() and svm_vcpu_run() by marking the RDMSR path as unlikely()
  KVM/x86: Remove indirect MSR op calls from SPEC_CTRL
  objtool, retpolines: Integrate objtool with retpoline support more closely
  x86/entry/64: Simplify ENCODE_FRAME_POINTER
  extable: Make init_kernel_text() global
  jump_label: Warn on failed jump_label patching attempt
  jump_label: Explicitly disable jump labels in __init code
  x86/entry/64: Open-code switch_to_thread_stack()
  x86/entry/64: Move ASM_CLAC to interrupt_entry()
  x86/entry/64: Remove 'interrupt' macro
  x86/entry/64: Move the switch_to_thread_stack() call to interrupt_entry()
  x86/entry/64: Move ENTER_IRQ_STACK from interrupt macro to interrupt_entry
  x86/entry/64: Move PUSH_AND_CLEAR_REGS from interrupt macro to helper function
  x86/speculation: Move firmware_restrict_branch_speculation_*() from C to CPP
  objtool: Add module specific retpoline rules
  objtool: Add retpoline validation
  objtool: Use existing global variables for options
  x86/mm/sme, objtool: Annotate indirect call in sme_encrypt_execute()
  x86/boot, objtool: Annotate indirect jump in secondary_startup_64()
  x86/paravirt, objtool: Annotate indirect calls
  ...
2018-02-26 09:34:21 -08:00
David S. Miller ba6056a41c Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Daniel Borkmann says:

====================
pull-request: bpf-next 2018-02-26

The following pull-request contains BPF updates for your *net-next* tree.

The main changes are:

1) Various improvements for BPF kselftests: i) skip unprivileged tests
   when kernel.unprivileged_bpf_disabled sysctl knob is set, ii) count
   the number of skipped tests from unprivileged, iii) when a test case
   had an unexpected error then print the actual but also the unexpected
   one for better comparison, from Joe.

2) Add a sample program for collecting CPU state statistics with regards
   to how long the CPU resides in cstate and pstate levels. Based on
   cpu_idle and cpu_frequency trace points, from Leo.

3) Various x64 BPF JIT optimizations to further shrink the generated
   image size in order to make it more icache friendly. When tested on
   the Cilium generated programs, image size reduced by approx 4-5% in
   best case mainly due to how LLVM emits unsigned 32 bit constants,
   from Daniel.

4) Improvements and fixes on the BPF sockmap sample programs: i) fix
   the sockmap's Makefile to include nlattr.o for libbpf, ii) detach
   the sock ops programs from the cgroup before exit, from Prashant.

5) Avoid including xdp.h in filter.h by just forward declaring the
   struct xdp_rxq_info in filter.h, from Jesper.

6) Fix the BPF kselftests Makefile for cgroup_helpers.c by only declaring
   it a dependency for test_dev_cgroup.c but not every other test case
   where it is not needed, from Jesper.

7) Adjust rlimit RLIMIT_MEMLOCK for test_tcpbpf_user selftest since the
   default is insufficient for creating the 'global_map' used in the
   corresponding BPF program, from Yonghong.

8) Likewise, for the xdp_redirect sample, Tushar ran into the same when
   invoking xdp_redirect and xdp_monitor at the same time, therefore
   in order to have the sample generically work bump the limit here,
   too. Fix from Tushar.

9) Avoid an unnecessary NULL check in BPF_CGROUP_RUN_PROG_INET_SOCK()
   since sk is always guaranteed to be non-NULL, from Yafang.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-26 10:37:24 -05:00
Linus Torvalds c23a757591 Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Thomas Gleixner:
 "A small set of fixes:

   - UAPI data type correction for hyperv

   - correct the cpu cores field in /proc/cpuinfo on CPU hotplug

   - return proper error code in the resctrl file system failure path to
     avoid silent subsequent failures

   - correct a subtle accounting issue in the new vector allocation code
     which went unnoticed for a while and caused suspend/resume
     failures"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/topology: Update the 'cpu cores' field in /proc/cpuinfo correctly across CPU hotplug operations
  x86/topology: Fix function name in documentation
  x86/intel_rdt: Fix incorrect returned value when creating rdgroup sub-directory in resctrl file system
  x86/apic/vector: Handle vector release on CPU unplug correctly
  genirq/matrix: Handle CPU offlining proper
  x86/headers/UAPI: Use __u64 instead of u64 in <uapi/asm/hyperv.h>
2018-02-25 16:58:55 -08:00
David S. Miller f74290fdb3 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-02-24 00:04:20 -05:00
Paul E. McKenney 338c46403f Merge branches 'fixes.2018.02.23a', 'srcu.2018.02.20a' and 'torture.2018.02.20a' into HEAD
fixes.2018.02.23a: Miscellaneous fixes
srcu.2018.02.20a: SRCU updates
torture.2018.02.20a: Torture-test updates
2018-02-23 15:15:41 -08:00
Paul E. McKenney ad7c946b35 rcu: Create RCU-specific workqueues with rescuers
RCU's expedited grace periods can participate in out-of-memory deadlocks
due to all available system_wq kthreads being blocked and there not being
memory available to create more.  This commit prevents such deadlocks
by allocating an RCU-specific workqueue_struct at early boot time, and
providing it with a rescuer to ensure forward progress.  This uses the
shiny new init_rescuer() function provided by Tejun (but indirectly).

This commit also causes SRCU to use this new RCU-specific
workqueue_struct.  Note that SRCU's use of workqueues never blocks them
waiting for readers, so this should be safe from a forward-progress
viewpoint.  Note that this moves SRCU from system_power_efficient_wq
to a normal workqueue.  In the unlikely event that this results in
measurable degradation, a separate power-efficient workqueue will be
creates for SRCU.

Reported-by: Prateek Sood <prsood@codeaurora.org>
Reported-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Tejun Heo <tj@kernel.org>
2018-02-23 15:14:40 -08:00
Linus Torvalds 9cb9c07d6b Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Pull networking fixes from David Miller:

 1) Fix TTL offset calculation in mac80211 mesh code, from Peter Oh.

 2) Fix races with procfs in ipt_CLUSTERIP, from Cong Wang.

 3) Memory leak fix in lpm_trie BPF map code, from Yonghong Song.

 4) Need to use GFP_ATOMIC in BPF cpumap allocations, from Jason Wang.

 5) Fix potential deadlocks in netfilter getsockopt() code paths, from
    Paolo Abeni.

 6) Netfilter stackpointer size checks really are needed to validate
    user input, from Florian Westphal.

 7) Missing timer init in x_tables, from Paolo Abeni.

 8) Don't use WQ_MEM_RECLAIM in mac80211 hwsim, from Johannes Berg.

 9) When an ibmvnic device is brought down then back up again, it can be
    sent queue entries from a previous session, handle this properly
    instead of crashing. From Thomas Falcon.

10) Fix TCP checksum on LRO buffers in mlx5e, from Gal Pressman.

11) When we are dumping filters in cls_api, the output SKB is empty, and
    the filter we are dumping is too large for the space in the SKB, we
    should return -EMSGSIZE like other netlink dump operations do.
    Otherwise userland has no signal that is needs to increase the size
    of its read buffer. From Roman Kapl.

12) Several XDP fixes for virtio_net, from Jesper Dangaard Brouer.

13) Module refcount leak in netlink when a dump start fails, from Jason
    Donenfeld.

14) Handle sub-optimal GSO sizes better in TCP BBR congestion control,
    from Eric Dumazet.

15) Releasing bpf per-cpu arraymaps can take a long time, add a
    condtional scheduling point. From Eric Dumazet.

16) Implement retpolines for tail calls in x64 and arm64 bpf JITs. From
    Daniel Borkmann.

17) Fix page leak in gianfar driver, from Andy Spencer.

18) Missed clearing of estimator scratch buffer, from Eric Dumazet.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (76 commits)
  net_sched: gen_estimator: fix broken estimators based on percpu stats
  gianfar: simplify FCS handling and fix memory leak
  ipv6 sit: work around bogus gcc-8 -Wrestrict warning
  macvlan: fix use-after-free in macvlan_common_newlink()
  bpf, arm64: fix out of bounds access in tail call
  bpf, x64: implement retpoline for tail call
  rxrpc: Fix send in rxrpc_send_data_packet()
  net: aquantia: Fix error handling in aq_pci_probe()
  bpf: fix rcu lockdep warning for lpm_trie map_free callback
  bpf: add schedule points in percpu arrays management
  regulatory: add NUL to request alpha2
  ibmvnic: Fix early release of login buffer
  net/smc9194: Remove bogus CONFIG_MAC reference
  net: ipv4: Set addr_type in hash_keys for forwarded case
  tcp_bbr: better deal with suboptimal GSO
  smsc75xx: fix smsc75xx_set_features()
  netlink: put module reference if dump start fails
  selftests/bpf/test_maps: exit child process without error in ENOMEM case
  selftests/bpf: update gitignore with test_libbpf_open
  selftests/bpf: tcpbpf_kern: use in6_* macros from glibc
  ..
2018-02-23 15:14:17 -08:00
Linus Torvalds 2eb02aa94f Merge branch 'fixes-v4.16-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull security subsystem fixes from James Morris:

 - keys fixes via David Howells:
      "A collection of fixes for Linux keyrings, mostly thanks to Eric
       Biggers:

        - Fix some PKCS#7 verification issues.

        - Fix handling of unsupported crypto in X.509.

        - Fix too-large allocation in big_key"

 - Seccomp updates via Kees Cook:
      "These are fixes for the get_metadata interface that landed during
       -rc1. While the new selftest is strictly not a bug fix, I think
       it's in the same spirit of avoiding bugs"

 - an IMA build fix from Randy Dunlap

* 'fixes-v4.16-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
  integrity/security: fix digsig.c build error with header file
  KEYS: Use individual pages in big_key for crypto buffers
  X.509: fix NULL dereference when restricting key with unsupported_sig
  X.509: fix BUG_ON() when hash algorithm is unsupported
  PKCS#7: fix direct verification of SignerInfo signature
  PKCS#7: fix certificate blacklisting
  PKCS#7: fix certificate chain verification
  seccomp: add a selftest for get_metadata
  ptrace, seccomp: tweak get_metadata behavior slightly
  seccomp, ptrace: switch get_metadata types to arch independent
2018-02-23 15:04:24 -08:00
Daniel Borkmann ca36960211 bpf: allow xadd only on aligned memory
The requirements around atomic_add() / atomic64_add() resp. their
JIT implementations differ across architectures. E.g. while x86_64
seems just fine with BPF's xadd on unaligned memory, on arm64 it
triggers via interpreter but also JIT the following crash:

  [  830.864985] Unable to handle kernel paging request at virtual address ffff8097d7ed6703
  [...]
  [  830.916161] Internal error: Oops: 96000021 [#1] SMP
  [  830.984755] CPU: 37 PID: 2788 Comm: test_verifier Not tainted 4.16.0-rc2+ #8
  [  830.991790] Hardware name: Huawei TaiShan 2280 /BC11SPCD, BIOS 1.29 07/17/2017
  [  830.998998] pstate: 80400005 (Nzcv daif +PAN -UAO)
  [  831.003793] pc : __ll_sc_atomic_add+0x4/0x18
  [  831.008055] lr : ___bpf_prog_run+0x1198/0x1588
  [  831.012485] sp : ffff00001ccabc20
  [  831.015786] x29: ffff00001ccabc20 x28: ffff8017d56a0f00
  [  831.021087] x27: 0000000000000001 x26: 0000000000000000
  [  831.026387] x25: 000000c168d9db98 x24: 0000000000000000
  [  831.031686] x23: ffff000008203878 x22: ffff000009488000
  [  831.036986] x21: ffff000008b14e28 x20: ffff00001ccabcb0
  [  831.042286] x19: ffff0000097b5080 x18: 0000000000000a03
  [  831.047585] x17: 0000000000000000 x16: 0000000000000000
  [  831.052885] x15: 0000ffffaeca8000 x14: 0000000000000000
  [  831.058184] x13: 0000000000000000 x12: 0000000000000000
  [  831.063484] x11: 0000000000000001 x10: 0000000000000000
  [  831.068783] x9 : 0000000000000000 x8 : 0000000000000000
  [  831.074083] x7 : 0000000000000000 x6 : 000580d428000000
  [  831.079383] x5 : 0000000000000018 x4 : 0000000000000000
  [  831.084682] x3 : ffff00001ccabcb0 x2 : 0000000000000001
  [  831.089982] x1 : ffff8097d7ed6703 x0 : 0000000000000001
  [  831.095282] Process test_verifier (pid: 2788, stack limit = 0x0000000018370044)
  [  831.102577] Call trace:
  [  831.105012]  __ll_sc_atomic_add+0x4/0x18
  [  831.108923]  __bpf_prog_run32+0x4c/0x70
  [  831.112748]  bpf_test_run+0x78/0xf8
  [  831.116224]  bpf_prog_test_run_xdp+0xb4/0x120
  [  831.120567]  SyS_bpf+0x77c/0x1110
  [  831.123873]  el0_svc_naked+0x30/0x34
  [  831.127437] Code: 97fffe97 17ffffec 00000000 f9800031 (885f7c31)

Reason for this is because memory is required to be aligned. In
case of BPF, we always enforce alignment in terms of stack access,
but not when accessing map values or packet data when the underlying
arch (e.g. arm64) has CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS set.

xadd on packet data that is local to us anyway is just wrong, so
forbid this case entirely. The only place where xadd makes sense in
fact are map values; xadd on stack is wrong as well, but it's been
around for much longer. Specifically enforce strict alignment in case
of xadd, so that we handle this case generically and avoid such crashes
in the first place.

Fixes: 17a5267067 ("bpf: verifier (add verifier core)")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-02-23 14:33:39 -08:00
Linus Torvalds 8961ca441b exynos, meson, ipuv3, secondary gpu, cirrus, edid quirk fixes
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Merge tag 'drm-fixes-for-v4.16-rc3' of git://people.freedesktop.org/~airlied/linux

Pull drm fixes from Dave Airlie:
 "A bunch of fixes for rc3:

  Exynos:
   - fixes for using monotonic timestamps
   - register definitions
   - removal of unused file

  ipu-v3L
   - minor changes
   - make some register arrays const+static
   - fix some leaks

  meson:
   - fix for vsync

  atomic:
   - fix for memory leak

  EDID parser:
   - add quirks for some more non-desktop devices
   - 6-bit panel fix.

  drm_mm:
   - fix a bug in the core drm mm hole handling

  cirrus:
   - fix lut loading regression

  Lastly there is a deadlock fix around runtime suspend for secondary
  GPUs.

  There was a deadlock between one thread trying to wait for a workqueue
  job to finish in the runtime suspend path, and the workqueue job it
  was waiting for in turn waiting for a runtime_get_sync to return.

  The fixes avoids it by not doing the runtime sync in the workqueue as
  then we always wait for all those tasks to complete before we runtime
  suspend"

* tag 'drm-fixes-for-v4.16-rc3' of git://people.freedesktop.org/~airlied/linux: (25 commits)
  drm/tve200: fix kernel-doc documentation comment include
  drm/edid: quirk Sony PlayStation VR headset as non-desktop
  drm/edid: quirk Windows Mixed Reality headsets as non-desktop
  drm/edid: quirk Oculus Rift headsets as non-desktop
  drm/meson: fix vsync buffer update
  drm: Handle unexpected holes in color-eviction
  drm: exynos: Use proper macro definition for HDMI_I2S_PIN_SEL_1
  drm/exynos: remove exynos_drm_rotator.h
  drm/exynos: g2d: Delete an error message for a failed memory allocation in two functions
  drm/exynos: fix comparison to bitshift when dealing with a mask
  drm/exynos: g2d: use monotonic timestamps
  drm/edid: Add 6 bpc quirk for CPT panel in Asus UX303LA
  gpu: ipu-csi: add 10/12-bit grayscale support to mbus_code_to_bus_cfg
  gpu: ipu-cpmem: add 16-bit grayscale support to ipu_cpmem_set_image
  gpu: ipu-v3: prg: fix device node leak in ipu_prg_lookup_by_phandle
  gpu: ipu-v3: pre: fix device node leak in ipu_pre_lookup_by_phandle
  drm/amdgpu: Fix deadlock on runtime suspend
  drm/radeon: Fix deadlock on runtime suspend
  drm/nouveau: Fix deadlock on runtime suspend
  drm: Allow determining if current task is output poll worker
  ...
2018-02-23 10:31:31 -08:00
Paul Moore ce423631ce audit: track the owner of the command mutex ourselves
Evidently the __mutex_owner() function was never intended for use
outside the core mutex code, so build a thing locking wrapper around
the mutex code which allows us to track the mutex owner.

One, arguably positive, side effect is that this allows us to hide
the audit_cmd_mutex inside of kernel/audit.c behind the lock/unlock
functions.

Reported-by: Peter Zijlstra <peterz@infradead.org>
Reviewed-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2018-02-23 11:22:22 -05:00
Thomas Gleixner 651ca2c004 genirq/matrix: Handle CPU offlining proper
At CPU hotunplug the corresponding per cpu matrix allocator is shut down and
the allocated interrupt bits are discarded under the assumption that all
allocated bits have been either migrated away or shut down through the
managed interrupts mechanism.

This is not true because interrupts which are not started up might have a
vector allocated on the outgoing CPU. When the interrupt is started up
later or completely shutdown and freed then the allocated vector is handed
back, triggering warnings or causing accounting issues which result in
suspend failures and other issues.

Change the CPU hotplug mechanism of the matrix allocator so that the
remaining allocations at unplug time are preserved and global accounting at
hotplug is correctly readjusted to take the dormant vectors into account.

Fixes: 2f75d9e1c9 ("genirq: Implement bitmap matrix allocator")
Reported-by: Yuriy Vostrikov <delamonpansie@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Yuriy Vostrikov <delamonpansie@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20180222112316.849980972@linutronix.de
2018-02-22 22:05:43 +01:00
Yonghong Song 6c5f61023c bpf: fix rcu lockdep warning for lpm_trie map_free callback
Commit 9a3efb6b66 ("bpf: fix memory leak in lpm_trie map_free callback function")
fixed a memory leak and removed unnecessary locks in map_free callback function.
Unfortrunately, it introduced a lockdep warning. When lockdep checking is turned on,
running tools/testing/selftests/bpf/test_lpm_map will have:

  [   98.294321] =============================
  [   98.294807] WARNING: suspicious RCU usage
  [   98.295359] 4.16.0-rc2+ #193 Not tainted
  [   98.295907] -----------------------------
  [   98.296486] /home/yhs/work/bpf/kernel/bpf/lpm_trie.c:572 suspicious rcu_dereference_check() usage!
  [   98.297657]
  [   98.297657] other info that might help us debug this:
  [   98.297657]
  [   98.298663]
  [   98.298663] rcu_scheduler_active = 2, debug_locks = 1
  [   98.299536] 2 locks held by kworker/2:1/54:
  [   98.300152]  #0:  ((wq_completion)"events"){+.+.}, at: [<00000000196bc1f0>] process_one_work+0x157/0x5c0
  [   98.301381]  #1:  ((work_completion)(&map->work)){+.+.}, at: [<00000000196bc1f0>] process_one_work+0x157/0x5c0

Since actual trie tree removal happens only after no other
accesses to the tree are possible, replacing
  rcu_dereference_protected(*slot, lockdep_is_held(&trie->lock))
with
  rcu_dereference_protected(*slot, 1)
fixed the issue.

Fixes: 9a3efb6b66 ("bpf: fix memory leak in lpm_trie map_free callback function")
Reported-by: Eric Dumazet <edumazet@google.com>
Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-02-22 21:29:12 +01:00
Eric Dumazet 32fff239de bpf: add schedule points in percpu arrays management
syszbot managed to trigger RCU detected stalls in
bpf_array_free_percpu()

It takes time to allocate a huge percpu map, but even more time to free
it.

Since we run in process context, use cond_resched() to yield cpu if
needed.

Fixes: a10423b87a ("bpf: introduce BPF_MAP_TYPE_PERCPU_ARRAY map")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-02-22 21:27:06 +01:00
Al Viro 304ec482f5 get rid of pointless includes of fs_struct.h
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-02-22 14:28:50 -05:00
James Morris 645ae5c51e - Fix seccomp GET_METADATA to deal with field sizes correctly (Tycho Andersen)
- Add selftest to make sure GET_METADATA doesn't regress (Tycho Andersen)
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Merge tag 'seccomp-v4.16-rc3' of https://git.kernel.org/pub/scm/linux/kernel/git/kees/linux into fixes-v4.16-rc3

- Fix seccomp GET_METADATA to deal with field sizes correctly (Tycho Andersen)
- Add selftest to make sure GET_METADATA doesn't regress (Tycho Andersen)
2018-02-22 10:50:24 -08:00
Linus Torvalds 238ca35707 Merge branch 'akpm' (patches from Andrew)
Merge misc fixes from Andrew Morton:
 "16 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  mm: don't defer struct page initialization for Xen pv guests
  lib/Kconfig.debug: enable RUNTIME_TESTING_MENU
  vmalloc: fix __GFP_HIGHMEM usage for vmalloc_32 on 32b systems
  selftests/memfd: add run_fuse_test.sh to TEST_FILES
  bug.h: work around GCC PR82365 in BUG()
  mm/swap.c: make functions and their kernel-doc agree (again)
  mm/zpool.c: zpool_evictable: fix mismatch in parameter name and kernel-doc
  ida: do zeroing in ida_pre_get()
  mm, swap, frontswap: fix THP swap if frontswap enabled
  certs/blacklist_nohashes.c: fix const confusion in certs blacklist
  kernel/relay.c: limit kmalloc size to KMALLOC_MAX_SIZE
  mm, mlock, vmscan: no more skipping pagevecs
  mm: memcontrol: fix NR_WRITEBACK leak in memcg and system stats
  Kbuild: always define endianess in kconfig.h
  include/linux/sched/mm.h: re-inline mmdrop()
  tools: fix cross-compile var clobbering
2018-02-22 10:45:46 -08:00
Luck, Tony bef3efbeb8 efivarfs: Limit the rate for non-root to read files
Each read from a file in efivarfs results in two calls to EFI
(one to get the file size, another to get the actual data).

On X86 these EFI calls result in broadcast system management
interrupts (SMI) which affect performance of the whole system.
A malicious user can loop performing reads from efivarfs bringing
the system to its knees.

Linus suggested per-user rate limit to solve this.

So we add a ratelimit structure to "user_struct" and initialize
it for the root user for no limit. When allocating user_struct for
other users we set the limit to 100 per second. This could be used
for other places that want to limit the rate of some detrimental
user action.

In efivarfs if the limit is exceeded when reading, we take an
interruptible nap for 50ms and check the rate limit again.

Signed-off-by: Tony Luck <tony.luck@intel.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-22 10:21:02 -08:00
Tycho Andersen 63bb0045b9 ptrace, seccomp: tweak get_metadata behavior slightly
Previously if users passed a small size for the input structure size, they
would get get odd behavior. It doesn't make sense to pass a structure
smaller than at least filter_off size, so let's just give -EINVAL in this
case.

This changes userspace visible behavior, but was only introduced in commit
26500475ac ("ptrace, seccomp: add support for retrieving seccomp
metadata") in 4.16-rc2, so should be safe to change if merged before then.

Reported-by: Eugene Syromiatnikov <esyr@redhat.com>
Signed-off-by: Tycho Andersen <tycho@tycho.ws>
CC: Kees Cook <keescook@chromium.org>
CC: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
2018-02-21 16:56:03 -08:00
Richard Guy Briggs 23138ead27 audit: return on memory error to avoid null pointer dereference
If there is a memory allocation error when trying to change an audit
kernel feature value, the ignored allocation error will trigger a NULL
pointer dereference oops on subsequent use of that pointer.  Return
instead.

Passes audit-testsuite.
See: https://github.com/linux-audit/audit-kernel/issues/76

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
[PM: not necessary (other funcs check for NULL), but a good practice]
Signed-off-by: Paul Moore <paul@paul-moore.com>
2018-02-21 18:45:36 -05:00
David Rientjes 88913bd8ea kernel/relay.c: limit kmalloc size to KMALLOC_MAX_SIZE
chan->n_subbufs is set by the user and relay_create_buf() does a kmalloc()
of chan->n_subbufs * sizeof(size_t *).

kmalloc_slab() will generate a warning when this fails if
chan->subbufs * sizeof(size_t *) > KMALLOC_MAX_SIZE.

Limit chan->n_subbufs to the maximum allowed kmalloc() size.

Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1802061216100.122576@chino.kir.corp.google.com
Fixes: f6302f1bcd ("relay: prevent integer overflow in relay_open()")
Signed-off-by: David Rientjes <rientjes@google.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-21 15:35:43 -08:00
Andrew Morton d34bc48f82 include/linux/sched/mm.h: re-inline mmdrop()
As Peter points out, Doing a CALL+RET for just the decrement is a bit silly.

Fixes: d70f2a14b7 ("include/linux/sched/mm.h: uninline mmdrop_async(), etc")
Acked-by: Peter Zijlstra (Intel) <peterz@infraded.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-21 15:35:42 -08:00
Dave Airlie dfe8db2237 Fixes for 4.16. I contains fixes for deadlock on runtime suspend on few
drivers, a memory leak on non-blocking commits, a crash on color-eviction.
 The is also meson and edid fixes, plus a fix for a doc warning.
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Merge tag 'drm-misc-fixes-2018-02-21' of git://anongit.freedesktop.org/drm/drm-misc into drm-fixes

Fixes for 4.16. I contains fixes for deadlock on runtime suspend on few
drivers, a memory leak on non-blocking commits, a crash on color-eviction.
The is also meson and edid fixes, plus a fix for a doc warning.

* tag 'drm-misc-fixes-2018-02-21' of git://anongit.freedesktop.org/drm/drm-misc:
  drm/tve200: fix kernel-doc documentation comment include
  drm/meson: fix vsync buffer update
  drm: Handle unexpected holes in color-eviction
  drm/edid: Add 6 bpc quirk for CPT panel in Asus UX303LA
  drm/amdgpu: Fix deadlock on runtime suspend
  drm/radeon: Fix deadlock on runtime suspend
  drm/nouveau: Fix deadlock on runtime suspend
  drm: Allow determining if current task is output poll worker
  workqueue: Allow retrieval of current task's work struct
  drm/atomic: Fix memleak on ERESTARTSYS during non-blocking commits
2018-02-22 08:39:26 +10:00
David S. Miller bf006d18b7 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Daniel Borkmann says:

====================
pull-request: bpf 2018-02-20

The following pull-request contains BPF updates for your *net* tree.

The main changes are:

1) Fix a memory leak in LPM trie's map_free() callback function, where
   the trie structure itself was not freed since initial implementation.
   Also a synchronize_rcu() was needed in order to wait for outstanding
   programs accessing the trie to complete, from Yonghong.

2) Fix sock_map_alloc()'s error path in order to correctly propagate
   the -EINVAL error in case of too large allocation requests. This
   was just recently introduced when fixing close hooks via ULP layer,
   fix from Eric.

3) Do not use GFP_ATOMIC in __cpu_map_entry_alloc(). Reason is that this
   will not work with the recent __ptr_ring_init_queue_alloc() conversion
   to kvmalloc_array(), where in case of fallback to vmalloc() that GFP
   flag is invalid, from Jason.

4) Fix two recent syzkaller warnings: i) fix bpf_prog_array_copy_to_user()
   when a prog query with a big number of ids was performed where we'd
   otherwise trigger a warning from allocator side, ii) fix a missing
   mlock precharge on arraymaps, from Daniel.

5) Two fixes for bpftool in order to avoid breaking JSON output when used
   in batch mode, from Quentin.

6) Move a pr_debug() in libbpf in order to avoid having an otherwise
   uninitialized variable in bpf_program__reloc_text(), from Jeremy.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-21 15:37:37 -05:00
Tejun Heo d1897c9538 cgroup: fix rule checking for threaded mode switching
A domain cgroup isn't allowed to be turned threaded if its subtree is
populated or domain controllers are enabled.  cgroup_enable_threaded()
depended on cgroup_can_be_thread_root() test to enforce this rule.  A
parent which has populated domain descendants or have domain
controllers enabled can't become a thread root, so the above rules are
enforced automatically.

However, for the root cgroup which can host mixed domain and threaded
children, cgroup_can_be_thread_root() doesn't check any of those
conditions and thus first level cgroups ends up escaping those rules.

This patch fixes the bug by adding explicit checks for those rules in
cgroup_enable_threaded().

Reported-by: Michael Kerrisk (man-pages) <mtk.manpages@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Fixes: 8cfd8147df ("cgroup: implement cgroup v2 thread support")
Cc: stable@vger.kernel.org # v4.14+
2018-02-21 11:39:22 -08:00
Josh Poimboeuf 9fbcc57aa1 extable: Make init_kernel_text() global
Convert init_kernel_text() to a global function and use it in a few
places instead of manually comparing _sinittext and _einittext.

Note that kallsyms.h has a very similar function called
is_kernel_inittext(), but its end check is inclusive.  I'm not sure
whether that's intentional behavior, so I didn't touch it.

Suggested-by: Jason Baron <jbaron@akamai.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/4335d02be8d45ca7d265d2f174251d0b7ee6c5fd.1519051220.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-02-21 16:54:06 +01:00
Josh Poimboeuf dc1dd184c2 jump_label: Warn on failed jump_label patching attempt
Currently when the jump label code encounters an address which isn't
recognized by kernel_text_address(), it just silently fails.

This can be dangerous because jump labels are used in a variety of
places, and are generally expected to work.  Convert the silent failure
to a warning.

This won't warn about attempted writes to tracepoints in __init code
after initmem has been freed, as those are already guarded by the
entry->code check.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Jason Baron <jbaron@akamai.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/de3a271c93807adb7ed48f4e946b4f9156617680.1519051220.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-02-21 16:54:06 +01:00
Josh Poimboeuf 3335224470 jump_label: Explicitly disable jump labels in __init code
After initmem has been freed, any jump labels in __init code are
prevented from being written to by the kernel_text_address() check in
__jump_label_update().  However, this check is quite broad.  If
kernel_text_address() were to return false for any other reason, the
jump label write would fail silently with no warning.

For jump labels in module init code, entry->code is set to zero to
indicate that the entry is disabled.  Do the same thing for core kernel
init code.  This makes the behavior more consistent, and will also make
it more straightforward to detect non-init jump label write failures in
the next patch.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Jason Baron <jbaron@akamai.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/c52825c73f3a174e8398b6898284ec20d4deb126.1519051220.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-02-21 16:54:05 +01:00
Frederic Weisbecker dcdedb2415 sched/nohz: Remove the 1 Hz tick code
Now that the 1Hz tick is offloaded to workqueues, we can safely remove
the residual code that used to handle it locally.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luiz Capitulino <lcapitulino@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Wanpeng Li <kernellwp@gmail.com>
Link: http://lkml.kernel.org/r/1519186649-3242-7-git-send-email-frederic@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-02-21 09:49:09 +01:00
Frederic Weisbecker d84b31313e sched/isolation: Offload residual 1Hz scheduler tick
When a CPU runs in full dynticks mode, a 1Hz tick remains in order to
keep the scheduler stats alive. However this residual tick is a burden
for bare metal tasks that can't stand any interruption at all, or want
to minimize them.

The usual boot parameters "nohz_full=" or "isolcpus=nohz" will now
outsource these scheduler ticks to the global workqueue so that a
housekeeping CPU handles those remotely. The sched_class::task_tick()
implementations have been audited and look safe to be called remotely
as the target runqueue and its current task are passed in parameter
and don't seem to be accessed locally.

Note that in the case of using isolcpus, it's still up to the user to
affine the global workqueues to the housekeeping CPUs through
/sys/devices/virtual/workqueue/cpumask or domains isolation
"isolcpus=nohz,domain".

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luiz Capitulino <lcapitulino@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Wanpeng Li <kernellwp@gmail.com>
Link: http://lkml.kernel.org/r/1519186649-3242-6-git-send-email-frederic@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-02-21 09:49:09 +01:00
Frederic Weisbecker 1bda3f8087 sched/isolation: Isolate workqueues when "nohz_full=" is set
As we prepare for offloading the residual 1hz scheduler ticks to
workqueue, let's affine those to housekeepers so that they don't
interrupt the CPUs that don't want to be disturbed.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luiz Capitulino <lcapitulino@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Wanpeng Li <kernellwp@gmail.com>
Link: http://lkml.kernel.org/r/1519186649-3242-5-git-send-email-frederic@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-02-21 09:49:08 +01:00
Frederic Weisbecker 22ab8bc02a nohz: Allow to check if remote CPU tick is stopped
This check is racy but provides a good heuristic to determine whether
a CPU may need a remote tick or not.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luiz Capitulino <lcapitulino@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Wanpeng Li <kernellwp@gmail.com>
Link: http://lkml.kernel.org/r/1519186649-3242-4-git-send-email-frederic@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-02-21 09:49:08 +01:00
Frederic Weisbecker a364298359 nohz: Convert tick_nohz_tick_stopped() to bool
It makes this function more self-explanatory about what it does and how
to use it.

Reported-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luiz Capitulino <lcapitulino@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Wanpeng Li <kernellwp@gmail.com>
Link: http://lkml.kernel.org/r/1519186649-3242-3-git-send-email-frederic@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-02-21 09:49:08 +01:00
Frederic Weisbecker 77a021be38 sched/core: Rename init_rq_hrtick() to hrtick_rq_init()
Do that rename in order to normalize the hrtick namespace.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luiz Capitulino <lcapitulino@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Wanpeng Li <kernellwp@gmail.com>
Link: http://lkml.kernel.org/r/1519186649-3242-2-git-send-email-frederic@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-02-21 09:49:07 +01:00
Mel Gorman 7347fc87df sched/numa: Delay retrying placement for automatic NUMA balance after wake_affine()
If wake_affine() pulls a task to another node for any reason and the node is
no longer preferred then temporarily stop automatic NUMA balancing pulling
the task back. Otherwise, tasks with a strong waker/wakee relationship
may constantly fight automatic NUMA balancing over where a task should
be placed.

Once again netperf is interesting here. The performance barely changes
but automatic NUMA balancing is interesting:

 Hmean     send-64         354.67 (   0.00%)      352.15 (  -0.71%)
 Hmean     send-128        702.91 (   0.00%)      693.84 (  -1.29%)
 Hmean     send-256       1350.07 (   0.00%)     1344.19 (  -0.44%)
 Hmean     send-1024      5124.38 (   0.00%)     4941.24 (  -3.57%)
 Hmean     send-2048      9687.44 (   0.00%)     9624.45 (  -0.65%)
 Hmean     send-3312     14577.64 (   0.00%)    14514.35 (  -0.43%)
 Hmean     send-4096     16393.62 (   0.00%)    16488.30 (   0.58%)
 Hmean     send-8192     26877.26 (   0.00%)    26431.63 (  -1.66%)
 Hmean     send-16384    38683.43 (   0.00%)    38264.91 (  -1.08%)
 Hmean     recv-64         354.67 (   0.00%)      352.15 (  -0.71%)
 Hmean     recv-128        702.91 (   0.00%)      693.84 (  -1.29%)
 Hmean     recv-256       1350.07 (   0.00%)     1344.19 (  -0.44%)
 Hmean     recv-1024      5124.38 (   0.00%)     4941.24 (  -3.57%)
 Hmean     recv-2048      9687.43 (   0.00%)     9624.45 (  -0.65%)
 Hmean     recv-3312     14577.59 (   0.00%)    14514.35 (  -0.43%)
 Hmean     recv-4096     16393.55 (   0.00%)    16488.20 (   0.58%)
 Hmean     recv-8192     26876.96 (   0.00%)    26431.29 (  -1.66%)
 Hmean     recv-16384    38682.41 (   0.00%)    38263.94 (  -1.08%)

 NUMA alloc hit                 1465986     1423090
 NUMA alloc miss                      0           0
 NUMA interleave hit                  0           0
 NUMA alloc local               1465897     1423003
 NUMA base PTE updates             1473        1420
 NUMA huge PMD updates                0           0
 NUMA page range updates           1473        1420
 NUMA hint faults                  1383        1312
 NUMA hint local faults             451         124
 NUMA hint local percent             32           9

There is a slight degrading in performance but there are slightly fewer
NUMA faults. There is a large drop in the percentage of local faults but
the bulk of migrations for netperf are in small shared libraries so it's
reflecting the fact that automatic NUMA balancing has backed off. This is
a case where despite wake_affine() and automatic NUMA balancing fighting
for placement that there is a marginal benefit to rescheduling to local
data quickly. However, it should be noted that wake_affine() and automatic
NUMA balancing fighting each other constantly is undesirable.

However, the benefit in other cases is large. This is the result for NAS
with the D class sizing on a 4-socket machine:

 nas-mpi
                           4.15.0                 4.15.0
                     sdnuma-v1r23       delayretry-v1r23
 Time cg.D      557.00 (   0.00%)      431.82 (  22.47%)
 Time ep.D       77.83 (   0.00%)       79.01 (  -1.52%)
 Time is.D       26.46 (   0.00%)       26.64 (  -0.68%)
 Time lu.D      727.14 (   0.00%)      597.94 (  17.77%)
 Time mg.D      191.35 (   0.00%)      146.85 (  23.26%)

               4.15.0      4.15.0
         sdnuma-v1r23delayretry-v1r23
 User        75665.20    70413.30
 System      20321.59     8861.67
 Elapsed       766.13      634.92

 Minor Faults                  16528502     7127941
 Major Faults                      4553        5068
 NUMA alloc local               6963197     6749135
 NUMA base PTE updates        366409093   107491434
 NUMA huge PMD updates           687556      198880
 NUMA page range updates      718437765   209317994
 NUMA hint faults              13643410     4601187
 NUMA hint local faults         9212593     3063996
 NUMA hint local percent             67          66

Note the massive reduction in system CPU usage even though the percentage
of local faults is barely affected. There is a massive reduction in the
number of PTE updates showing that automatic NUMA balancing has backed off.
A critical observation is also that there is a massive reduction in minor
faults which is due to far fewer NUMA hinting faults being trapped.

There were questions on NAS OMP and how it behaved related to threads
being bound to CPUs. First, there are more gains than losses with this
patch applied and a reduction in system CPU usage:

nas-omp
                      4.16.0-rc1             4.16.0-rc1
                     sdnuma-v2r1        delayretry-v2r1
Time bt.D      436.71 (   0.00%)      430.05 (   1.53%)
Time cg.D      201.02 (   0.00%)      180.87 (  10.02%)
Time ep.D       32.84 (   0.00%)       32.68 (   0.49%)
Time is.D        9.63 (   0.00%)        9.64 (  -0.10%)
Time lu.D      331.20 (   0.00%)      304.80 (   7.97%)
Time mg.D       54.87 (   0.00%)       52.72 (   3.92%)
Time sp.D     1108.78 (   0.00%)      917.10 (  17.29%)
Time ua.D      378.81 (   0.00%)      398.83 (  -5.28%)

          4.16.0-rc1  4.16.0-rc1
         sdnuma-v2r1delayretry-v2r1
User       305633.08   296751.91
System        451.75      357.80
Elapsed      2595.73     2368.13

However, it does not close the gap between binding and being unbound. There
is negligible difference between the performance of the baseline and a
patched kernel when threads are bound so it is not presented here:

                      4.16.0-rc1             4.16.0-rc1
                 delayretry-bind     delayretry-unbound
Time bt.D      385.02 (   0.00%)      430.05 ( -11.70%)
Time cg.D      144.02 (   0.00%)      180.87 ( -25.59%)
Time ep.D       32.85 (   0.00%)       32.68 (   0.52%)
Time is.D       10.52 (   0.00%)        9.64 (   8.37%)
Time lu.D      285.31 (   0.00%)      304.80 (  -6.83%)
Time mg.D       43.21 (   0.00%)       52.72 ( -22.01%)
Time sp.D      820.24 (   0.00%)      917.10 ( -11.81%)
Time ua.D      337.09 (   0.00%)      398.83 ( -18.32%)

          4.16.0-rc1  4.16.0-rc1
        delayretry-binddelayretry-unbound
User       277731.25   296751.91
System        261.29      357.80
Elapsed      2100.55     2368.13

Unfortunately, while performance is improved by the patch, there is still
quite a long way to go before it's equivalent to hard binding.

Other workloads like hackbench, tbench, dbench and schbench are barely
affected. dbench shows a mix of gains and losses depending on the machine
although in general, the results are more stable.

Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Giovanni Gherdovich <ggherdovich@suse.cz>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20180213133730.24064-7-mgorman@techsingularity.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-02-21 08:49:45 +01:00
Mel Gorman 2c83362734 sched/fair: Consider SD_NUMA when selecting the most idle group to schedule on
find_idlest_group() compares a local group with each other group to select
the one that is most idle. When comparing groups in different NUMA domains,
a very slight imbalance is enough to select a remote NUMA node even if the
runnable load on both groups is 0 or close to 0. This ignores the cost of
remote accesses entirely and is a problem when selecting the CPU for a
newly forked task to run on.  This is problematic when a forking server
is almost guaranteed to run on a remote node incurring numerous remote
accesses and potentially causing automatic NUMA balancing to try migrate
the task back or migrate the data to another node. Similar weirdness is
observed if a basic shell command pipes output to another as each process
in the pipeline is likely to start on different nodes and then get adjusted
later by wake_affine().

This patch adds imbalance to remote domains when considering whether to
select CPUs from remote domains. If the local domain is selected, imbalance
will still be used to try select a CPU from a lower scheduler domain's group
instead of stacking tasks on the same CPU.

A variety of workloads and machines were tested and as expected, there is no
difference on UMA. The difference on NUMA can be dramatic. This is a comparison
of elapsed times running the git regression test suite. It's fork-intensive with
short-lived processes:

                                  4.15.0                 4.15.0
                            noexit-v1r23           sdnuma-v1r23
 Elapsed min          1706.06 (   0.00%)     1435.94 (  15.83%)
 Elapsed mean         1709.53 (   0.00%)     1436.98 (  15.94%)
 Elapsed stddev          2.16 (   0.00%)        1.01 (  53.38%)
 Elapsed coeffvar        0.13 (   0.00%)        0.07 (  44.54%)
 Elapsed max          1711.59 (   0.00%)     1438.01 (  15.98%)

               4.15.0      4.15.0
         noexit-v1r23 sdnuma-v1r23
 User         5434.12     5188.41
 System       4878.77     3467.09
 Elapsed     10259.06     8624.21

That shows a considerable reduction in elapsed times. It's important to
note that automatic NUMA balancing does not affect this load as processes
are too short-lived.

There is also a noticable impact on hackbench such as this example using
processes and pipes:

 hackbench-process-pipes
                               4.15.0                 4.15.0
                         noexit-v1r23           sdnuma-v1r23
 Amean     1        1.0973 (   0.00%)      0.9393 (  14.40%)
 Amean     4        1.3427 (   0.00%)      1.3730 (  -2.26%)
 Amean     7        1.4233 (   0.00%)      1.6670 ( -17.12%)
 Amean     12       3.0250 (   0.00%)      3.3013 (  -9.13%)
 Amean     21       9.0860 (   0.00%)      9.5343 (  -4.93%)
 Amean     30      14.6547 (   0.00%)     13.2433 (   9.63%)
 Amean     48      22.5447 (   0.00%)     20.4303 (   9.38%)
 Amean     79      29.2010 (   0.00%)     26.7853 (   8.27%)
 Amean     110     36.7443 (   0.00%)     35.8453 (   2.45%)
 Amean     141     45.8533 (   0.00%)     42.6223 (   7.05%)
 Amean     172     55.1317 (   0.00%)     50.6473 (   8.13%)
 Amean     203     64.4420 (   0.00%)     58.3957 (   9.38%)
 Amean     234     73.2293 (   0.00%)     67.1047 (   8.36%)
 Amean     265     80.5220 (   0.00%)     75.7330 (   5.95%)
 Amean     296     88.7567 (   0.00%)     82.1533 (   7.44%)

It's not a universal win as there are occasions when spreading wide and
quickly is a benefit but it's more of a win than it is a loss. For other
workloads, there is little difference but netperf is interesting. Without
the patch, the server and client starts on different nodes but quickly get
migrated due to wake_affine. Hence, the difference is overall performance
is marginal but detectable:

                                      4.15.0                 4.15.0
                                noexit-v1r23           sdnuma-v1r23
 Hmean     send-64         349.09 (   0.00%)      354.67 (   1.60%)
 Hmean     send-128        699.16 (   0.00%)      702.91 (   0.54%)
 Hmean     send-256       1316.34 (   0.00%)     1350.07 (   2.56%)
 Hmean     send-1024      5063.99 (   0.00%)     5124.38 (   1.19%)
 Hmean     send-2048      9705.19 (   0.00%)     9687.44 (  -0.18%)
 Hmean     send-3312     14359.48 (   0.00%)    14577.64 (   1.52%)
 Hmean     send-4096     16324.20 (   0.00%)    16393.62 (   0.43%)
 Hmean     send-8192     26112.61 (   0.00%)    26877.26 (   2.93%)
 Hmean     send-16384    37208.44 (   0.00%)    38683.43 (   3.96%)
 Hmean     recv-64         349.09 (   0.00%)      354.67 (   1.60%)
 Hmean     recv-128        699.16 (   0.00%)      702.91 (   0.54%)
 Hmean     recv-256       1316.34 (   0.00%)     1350.07 (   2.56%)
 Hmean     recv-1024      5063.99 (   0.00%)     5124.38 (   1.19%)
 Hmean     recv-2048      9705.16 (   0.00%)     9687.43 (  -0.18%)
 Hmean     recv-3312     14359.42 (   0.00%)    14577.59 (   1.52%)
 Hmean     recv-4096     16323.98 (   0.00%)    16393.55 (   0.43%)
 Hmean     recv-8192     26111.85 (   0.00%)    26876.96 (   2.93%)
 Hmean     recv-16384    37206.99 (   0.00%)    38682.41 (   3.97%)

However, what is very interesting is how automatic NUMA balancing behaves.
Each netperf instance runs long enough for balancing to activate:

 NUMA base PTE updates             4620        1473
 NUMA huge PMD updates                0           0
 NUMA page range updates           4620        1473
 NUMA hint faults                  4301        1383
 NUMA hint local faults            1309         451
 NUMA hint local percent             30          32
 NUMA pages migrated               1335         491
 AutoNUMA cost                      21%          6%

There is an unfortunate number of remote faults although tracing indicated
that the vast majority are in shared libraries. However, the tendency to
start tasks on the same node if there is capacity means that there were
far fewer PTE updates and faults incurred overall.

Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Giovanni Gherdovich <ggherdovich@suse.cz>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20180213133730.24064-6-mgorman@techsingularity.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-02-21 08:49:43 +01:00
Peter Zijlstra 24d0c1d6e6 sched/fair: Do not migrate due to a sync wakeup on exit
When a task exits, it notifies the parent that it has exited. This is a
sync wakeup and the exiting task may pull the parent towards the wakers
CPU. For simple workloads like using a shell, it was observed that the
shell is pulled across nodes by exiting processes. This is daft as the
parent may be long-lived and properly placed. This patch special cases a
sync wakeup on exit to avoid pulling tasks across nodes. Testing on a range
of workloads and machines showed very little differences in performance
although there was a small 3% boost on some machines running a shellscript
intensive workload (git regression test suite).

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Giovanni Gherdovich <ggherdovich@suse.cz>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20180213133730.24064-5-mgorman@techsingularity.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-02-21 08:49:42 +01:00
Mel Gorman 082f764a2f sched/fair: Do not migrate on wake_affine_weight() if weights are equal
wake_affine_weight() will consider migrating a task to, or near, the current
CPU if there is a load imbalance. If the CPUs share LLC then either CPU
is valid as a search-for-idle-sibling target and equally appropriate for
stacking two tasks on one CPU if an idle sibling is unavailable. If they do
not share cache then a cross-node migration potentially impacts locality
so while they are equal from a CPU capacity point of view, they are not
equal in terms of memory locality. In either case, it's more appropriate
to migrate only if there is a difference in their effective load.

This patch modifies wake_affine_weight() to only consider migrating a task
if there is a load imbalance for normal wakeups but will allow potential
stacking if the loads are equal and it's a sync wakeup.

For the most part, the different in performance is marginal. For example,
on a 4-socket server running netperf UDP_STREAM on localhost the differences
are as follows:

                                      4.15.0                 4.15.0
                                       16rc0          noequal-v1r23
 Hmean     send-64         355.47 (   0.00%)      349.50 (  -1.68%)
 Hmean     send-128        697.98 (   0.00%)      693.35 (  -0.66%)
 Hmean     send-256       1328.02 (   0.00%)     1318.77 (  -0.70%)
 Hmean     send-1024      5051.83 (   0.00%)     5051.11 (  -0.01%)
 Hmean     send-2048      9637.02 (   0.00%)     9601.34 (  -0.37%)
 Hmean     send-3312     14355.37 (   0.00%)    14414.51 (   0.41%)
 Hmean     send-4096     16464.97 (   0.00%)    16301.37 (  -0.99%)
 Hmean     send-8192     26722.42 (   0.00%)    26428.95 (  -1.10%)
 Hmean     send-16384    38137.81 (   0.00%)    38046.11 (  -0.24%)
 Hmean     recv-64         355.47 (   0.00%)      349.50 (  -1.68%)
 Hmean     recv-128        697.98 (   0.00%)      693.35 (  -0.66%)
 Hmean     recv-256       1328.02 (   0.00%)     1318.77 (  -0.70%)
 Hmean     recv-1024      5051.83 (   0.00%)     5051.11 (  -0.01%)
 Hmean     recv-2048      9636.95 (   0.00%)     9601.30 (  -0.37%)
 Hmean     recv-3312     14355.32 (   0.00%)    14414.48 (   0.41%)
 Hmean     recv-4096     16464.74 (   0.00%)    16301.16 (  -0.99%)
 Hmean     recv-8192     26721.63 (   0.00%)    26428.17 (  -1.10%)
 Hmean     recv-16384    38136.00 (   0.00%)    38044.88 (  -0.24%)
 Stddev    send-64           7.30 (   0.00%)        4.75 (  34.96%)
 Stddev    send-128         15.15 (   0.00%)       22.38 ( -47.66%)
 Stddev    send-256         13.99 (   0.00%)       19.14 ( -36.81%)
 Stddev    send-1024       105.73 (   0.00%)       67.38 (  36.27%)
 Stddev    send-2048       294.57 (   0.00%)      223.88 (  24.00%)
 Stddev    send-3312       302.28 (   0.00%)      271.74 (  10.10%)
 Stddev    send-4096       195.92 (   0.00%)      121.10 (  38.19%)
 Stddev    send-8192       399.71 (   0.00%)      563.77 ( -41.04%)
 Stddev    send-16384     1163.47 (   0.00%)     1103.68 (   5.14%)
 Stddev    recv-64           7.30 (   0.00%)        4.75 (  34.96%)
 Stddev    recv-128         15.15 (   0.00%)       22.38 ( -47.66%)
 Stddev    recv-256         13.99 (   0.00%)       19.14 ( -36.81%)
 Stddev    recv-1024       105.73 (   0.00%)       67.38 (  36.27%)
 Stddev    recv-2048       294.59 (   0.00%)      223.89 (  24.00%)
 Stddev    recv-3312       302.24 (   0.00%)      271.75 (  10.09%)
 Stddev    recv-4096       196.03 (   0.00%)      121.14 (  38.20%)
 Stddev    recv-8192       399.86 (   0.00%)      563.65 ( -40.96%)
 Stddev    recv-16384     1163.79 (   0.00%)     1103.86 (   5.15%)

The difference in overall performance is marginal but note that most
measurements are less variable. There were similar observations for other
netperf comparisons. hackbench with sockets or threads with processes or
threads showed minor difference with some reduction of migration. tbench
showed only marginal differences that were within the noise. dbench,
regardless of filesystem, showed minor differences all of which are
within noise. Multiple machines, both UMA and NUMA were tested without
any regressions showing up.

The biggest risk with a patch like this is affecting wakeup latencies.
However, the schbench load from Facebook which is very sensitive to wakeup
latency showed a mixed result with mostly improvements in wakeup latency:

                                      4.15.0                 4.15.0
                                       16rc0          noequal-v1r23
 Lat 50.00th-qrtle-1        38.00 (   0.00%)       38.00 (   0.00%)
 Lat 75.00th-qrtle-1        49.00 (   0.00%)       41.00 (  16.33%)
 Lat 90.00th-qrtle-1        52.00 (   0.00%)       50.00 (   3.85%)
 Lat 95.00th-qrtle-1        54.00 (   0.00%)       51.00 (   5.56%)
 Lat 99.00th-qrtle-1        63.00 (   0.00%)       60.00 (   4.76%)
 Lat 99.50th-qrtle-1        66.00 (   0.00%)       61.00 (   7.58%)
 Lat 99.90th-qrtle-1        78.00 (   0.00%)       65.00 (  16.67%)
 Lat 50.00th-qrtle-2        38.00 (   0.00%)       38.00 (   0.00%)
 Lat 75.00th-qrtle-2        42.00 (   0.00%)       43.00 (  -2.38%)
 Lat 90.00th-qrtle-2        46.00 (   0.00%)       48.00 (  -4.35%)
 Lat 95.00th-qrtle-2        49.00 (   0.00%)       50.00 (  -2.04%)
 Lat 99.00th-qrtle-2        55.00 (   0.00%)       57.00 (  -3.64%)
 Lat 99.50th-qrtle-2        58.00 (   0.00%)       60.00 (  -3.45%)
 Lat 99.90th-qrtle-2        65.00 (   0.00%)       68.00 (  -4.62%)
 Lat 50.00th-qrtle-4        41.00 (   0.00%)       41.00 (   0.00%)
 Lat 75.00th-qrtle-4        45.00 (   0.00%)       46.00 (  -2.22%)
 Lat 90.00th-qrtle-4        50.00 (   0.00%)       50.00 (   0.00%)
 Lat 95.00th-qrtle-4        54.00 (   0.00%)       53.00 (   1.85%)
 Lat 99.00th-qrtle-4        61.00 (   0.00%)       61.00 (   0.00%)
 Lat 99.50th-qrtle-4        65.00 (   0.00%)       64.00 (   1.54%)
 Lat 99.90th-qrtle-4        76.00 (   0.00%)       82.00 (  -7.89%)
 Lat 50.00th-qrtle-8        48.00 (   0.00%)       46.00 (   4.17%)
 Lat 75.00th-qrtle-8        55.00 (   0.00%)       54.00 (   1.82%)
 Lat 90.00th-qrtle-8        60.00 (   0.00%)       59.00 (   1.67%)
 Lat 95.00th-qrtle-8        63.00 (   0.00%)       63.00 (   0.00%)
 Lat 99.00th-qrtle-8        71.00 (   0.00%)       69.00 (   2.82%)
 Lat 99.50th-qrtle-8        74.00 (   0.00%)       73.00 (   1.35%)
 Lat 99.90th-qrtle-8        98.00 (   0.00%)       90.00 (   8.16%)
 Lat 50.00th-qrtle-16       56.00 (   0.00%)       55.00 (   1.79%)
 Lat 75.00th-qrtle-16       68.00 (   0.00%)       67.00 (   1.47%)
 Lat 90.00th-qrtle-16       77.00 (   0.00%)       78.00 (  -1.30%)
 Lat 95.00th-qrtle-16       82.00 (   0.00%)       84.00 (  -2.44%)
 Lat 99.00th-qrtle-16       90.00 (   0.00%)       93.00 (  -3.33%)
 Lat 99.50th-qrtle-16       93.00 (   0.00%)       97.00 (  -4.30%)
 Lat 99.90th-qrtle-16      110.00 (   0.00%)      110.00 (   0.00%)
 Lat 50.00th-qrtle-32       68.00 (   0.00%)       62.00 (   8.82%)
 Lat 75.00th-qrtle-32       90.00 (   0.00%)       83.00 (   7.78%)
 Lat 90.00th-qrtle-32      110.00 (   0.00%)      100.00 (   9.09%)
 Lat 95.00th-qrtle-32      122.00 (   0.00%)      111.00 (   9.02%)
 Lat 99.00th-qrtle-32      145.00 (   0.00%)      133.00 (   8.28%)
 Lat 99.50th-qrtle-32      154.00 (   0.00%)      143.00 (   7.14%)
 Lat 99.90th-qrtle-32     2316.00 (   0.00%)      515.00 (  77.76%)
 Lat 50.00th-qrtle-35       69.00 (   0.00%)       72.00 (  -4.35%)
 Lat 75.00th-qrtle-35       92.00 (   0.00%)       95.00 (  -3.26%)
 Lat 90.00th-qrtle-35      111.00 (   0.00%)      114.00 (  -2.70%)
 Lat 95.00th-qrtle-35      122.00 (   0.00%)      124.00 (  -1.64%)
 Lat 99.00th-qrtle-35      142.00 (   0.00%)      144.00 (  -1.41%)
 Lat 99.50th-qrtle-35      150.00 (   0.00%)      154.00 (  -2.67%)
 Lat 99.90th-qrtle-35     6104.00 (   0.00%)     5640.00 (   7.60%)

Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Giovanni Gherdovich <ggherdovich@suse.cz>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20180213133730.24064-4-mgorman@techsingularity.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-02-21 08:49:08 +01:00
Mel Gorman eeb6039863 sched/fair: Defer calculation of 'prev_eff_load' in wake_affine_weight() until needed
On sync wakeups, the previous CPU effective load may not be used so delay
the calculation until it's needed.

Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Giovanni Gherdovich <ggherdovich@suse.cz>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20180213133730.24064-3-mgorman@techsingularity.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-02-21 08:49:07 +01:00
Mel Gorman 7ebb66a12f sched/fair: Avoid an unnecessary lookup of current CPU ID during wake_affine
The only caller of wake_affine() knows the CPU ID. Pass it in instead of
rechecking it.

Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Giovanni Gherdovich <ggherdovich@suse.cz>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20180213133730.24064-2-mgorman@techsingularity.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-02-21 08:49:07 +01:00
Ingo Molnar ed02934395 Linux 4.16-rc2
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Merge tag 'v4.16-rc2' into sched/core, to pick up fixes

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-02-21 08:48:35 +01:00
Paul E. McKenney 85ba6bfe8b torture: Provide more sensible nreader/nwriter defaults for rcuperf
The default values for nreader and nwriter are apparently not all that
user-friendly, resulting in people doing scalability tests that ran all
runs at large scale.  This commit therefore makes both the nreaders and
nwriters module default to the number of CPUs, and adds a comment to
rcuperf.c stating that the number of CPUs should be specified using the
nr_cpus kernel boot parameter.  This commit also eliminates the redundant
rcuperf scripting specification of default values for these parameters.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-02-20 16:22:01 -08:00
Paul E. McKenney db0c1a8aba rcutorture: Record which grace-period primitives are tested
The rcu_torture_writer() function adapts to requested testing from module
parameters as well as the function pointers in the structure referenced
by cur_ops.  However, as long as the module parameters do not conflict
with the function pointers, this adaptation is silent.  This silence can
result in confusion as to exactly what was tested, which could in turn
result in untested RCU code making its way into mainline.

This commit therefore makes rcu_torture_writer() announce exactly which
portions of RCU's API it ends up testing.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-02-20 16:21:58 -08:00