Commit Graph

4798 Commits

Author SHA1 Message Date
Qiujun Huang 499f7bb085 tracing: Fix some typos in comments
s/wihin/within/
s/retrieven/retrieved/
s/suppport/support/
s/wil/will/
s/accidently/accidentally/
s/if the if the/if the/

Link: https://lkml.kernel.org/r/20201010140924.3809-1-hqjagain@gmail.com

Signed-off-by: Qiujun Huang <hqjagain@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-10-15 12:01:13 -04:00
Masami Hiramatsu c163409719 tracing/boot: Add ftrace.instance.*.alloc_snapshot option
Add ftrace.instance.*.alloc_snapshot option.

This option has been described in Documentation/trace/boottime-trace.rst
but not implemented yet.

ftrace.[instance.INSTANCE.]alloc_snapshot
   Allocate snapshot buffer.

The difference from kernel.alloc_snapshot is that the kernel.alloc_snapshot
will allocate the buffer only for the main instance, but this can allocate
buffer for any new instances.

Link: https://lkml.kernel.org/r/160234368948.400560.15313384470765915015.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-10-15 12:01:13 -04:00
Gaurav Kohli bbeb97464e tracing: Fix race in trace_open and buffer resize call
Below race can come, if trace_open and resize of
cpu buffer is running parallely on different cpus
CPUX                                CPUY
				    ring_buffer_resize
				    atomic_read(&buffer->resize_disabled)
tracing_open
tracing_reset_online_cpus
ring_buffer_reset_cpu
rb_reset_cpu
				    rb_update_pages
				    remove/insert pages
resetting pointer

This race can cause data abort or some times infinte loop in
rb_remove_pages and rb_insert_pages while checking pages
for sanity.

Take buffer lock to fix this.

Link: https://lkml.kernel.org/r/1601976833-24377-1-git-send-email-gkohli@codeaurora.org

Cc: stable@vger.kernel.org
Fixes: b23d7a5f4a ("ring-buffer: speed up buffer resets by avoiding synchronize_rcu for each CPU")
Signed-off-by: Gaurav Kohli <gkohli@codeaurora.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-10-15 12:01:13 -04:00
Steven Rostedt (VMware) 6d9bd13945 tracing: Check return value of __create_val_fields() before using its result
After having a typo for writing a histogram trigger.

Wrote:
  echo 'hist:key=pid:ts=common_timestamp.usec' > events/sched/sched_waking/trigger

Instead of:
  echo 'hist:key=pid:ts=common_timestamp.usecs' > events/sched/sched_waking/trigger

and the following crash happened:

 BUG: kernel NULL pointer dereference, address: 0000000000000008
 #PF: supervisor read access in kernel mode
 #PF: error_code(0x0000) - not-present page
 PGD 0 P4D 0
 Oops: 0000 [#1] PREEMPT SMP PTI
 CPU: 4 PID: 1641 Comm: sh Not tainted 5.9.0-rc5-test+ #549
 Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01 v03.03 07/14/2016
 RIP: 0010:event_hist_trigger_func+0x70b/0x1ee0
 Code: 24 08 89 d5 49 89 cc e9 8c 00 00 00 4c 89 f2 41 b9 00 10 00 00 4c 89 e1 44 89 ee 4c 89 ff e8 dc d3 ff ff 45 89 ea 4b 8b 14 d7 <f6> 42 08 04 74 17 41 8b 8f c0 00 00 00 8d 71 01 41 89 b7 c0 00 00
 RSP: 0018:ffff959213d53db0 EFLAGS: 00010202
 RAX: ffffffffffffffea RBX: 0000000000000000 RCX: 0000000000084c04
 RDX: 0000000000000000 RSI: df7326aefebd174c RDI: 0000000000031080
 RBP: 0000000000000002 R08: 0000000000000001 R09: 0000000000000001
 R10: 0000000000000001 R11: 0000000000000046 R12: ffff959211dcf690
 R13: 0000000000000001 R14: ffff95925a36e370 R15: ffff959251c89800
 FS:  00007fb9ea934740(0000) GS:ffff95925ab00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000000008 CR3: 00000000c976c005 CR4: 00000000001706e0
 Call Trace:
  ? trigger_process_regex+0x78/0x110
  trigger_process_regex+0xc5/0x110
  event_trigger_write+0x71/0xd0
  vfs_write+0xca/0x210
  ksys_write+0x70/0xf0
  do_syscall_64+0x33/0x40
  entry_SYSCALL_64_after_hwframe+0x44/0xa9
 RIP: 0033:0x7fb9eaa29487
 Code: 64 89 02 48 c7 c0 ff ff ff ff eb bb 0f 1f 80 00 00 00 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 48 89 54 24 18 48 89 74 24

This was caused by accessing the hlist_data fields after the call to
__create_val_fields() without checking if the creation succeed.

Link: https://lkml.kernel.org/r/20201013154852.3abd8702@gandalf.local.home

Fixes: 63a1e5de30 ("tracing: Save normal string variables")
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-10-15 12:00:59 -04:00
Linus Torvalds 3ad11d7ac8 block-5.10-2020-10-12
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Merge tag 'block-5.10-2020-10-12' of git://git.kernel.dk/linux-block

Pull block updates from Jens Axboe:

 - Series of merge handling cleanups (Baolin, Christoph)

 - Series of blk-throttle fixes and cleanups (Baolin)

 - Series cleaning up BDI, seperating the block device from the
   backing_dev_info (Christoph)

 - Removal of bdget() as a generic API (Christoph)

 - Removal of blkdev_get() as a generic API (Christoph)

 - Cleanup of is-partition checks (Christoph)

 - Series reworking disk revalidation (Christoph)

 - Series cleaning up bio flags (Christoph)

 - bio crypt fixes (Eric)

 - IO stats inflight tweak (Gabriel)

 - blk-mq tags fixes (Hannes)

 - Buffer invalidation fixes (Jan)

 - Allow soft limits for zone append (Johannes)

 - Shared tag set improvements (John, Kashyap)

 - Allow IOPRIO_CLASS_RT for CAP_SYS_NICE (Khazhismel)

 - DM no-wait support (Mike, Konstantin)

 - Request allocation improvements (Ming)

 - Allow md/dm/bcache to use IO stat helpers (Song)

 - Series improving blk-iocost (Tejun)

 - Various cleanups (Geert, Damien, Danny, Julia, Tetsuo, Tian, Wang,
   Xianting, Yang, Yufen, yangerkun)

* tag 'block-5.10-2020-10-12' of git://git.kernel.dk/linux-block: (191 commits)
  block: fix uapi blkzoned.h comments
  blk-mq: move cancel of hctx->run_work to the front of blk_exit_queue
  blk-mq: get rid of the dead flush handle code path
  block: get rid of unnecessary local variable
  block: fix comment and add lockdep assert
  blk-mq: use helper function to test hw stopped
  block: use helper function to test queue register
  block: remove redundant mq check
  block: invoke blk_mq_exit_sched no matter whether have .exit_sched
  percpu_ref: don't refer to ref->data if it isn't allocated
  block: ratelimit handle_bad_sector() message
  blk-throttle: Re-use the throtl_set_slice_end()
  blk-throttle: Open code __throtl_de/enqueue_tg()
  blk-throttle: Move service tree validation out of the throtl_rb_first()
  blk-throttle: Move the list operation after list validation
  blk-throttle: Fix IO hang for a corner case
  blk-throttle: Avoid tracking latency if low limit is invalid
  blk-throttle: Avoid getting the current time if tg->last_finish_time is 0
  blk-throttle: Remove a meaningless parameter for throtl_downgrade_state()
  block: Remove redundant 'return' statement
  ...
2020-10-13 12:12:44 -07:00
Jakub Kicinski ccdf7fae3a Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Alexei Starovoitov says:

====================
pull-request: bpf-next 2020-10-12

The main changes are:

1) The BPF verifier improvements to track register allocation pattern, from Alexei and Yonghong.

2) libbpf relocation support for different size load/store, from Andrii.

3) bpf_redirect_peer() helper and support for inner map array with different max_entries, from Daniel.

4) BPF support for per-cpu variables, form Hao.

5) sockmap improvements, from John.
====================

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-10-12 16:16:50 -07:00
Linus Torvalds 3bff6112c8 These are the performance events changes for v5.10:
x86 Intel updates:
 
  - Add Jasper Lake support
 
  - Add support for TopDown metrics on Ice Lake
 
  - Fix Ice Lake & Tiger Lake uncore support, add Snow Ridge support
 
  - Add a PCI sub driver to support uncore PMUs where the PCI resources
    have been claimed already - extending the range of supported systems.
 
 x86 AMD updates:
 
  - Restore 'perf stat -a' behaviour to program the uncore PMU
    to count all CPU threads.
 
  - Fix setting the proper count when sampling Large Increment
    per Cycle events / 'paired' events.
 
  - Fix IBS Fetch sampling on F17h and some other IBS fine tuning,
    greatly reducing the number of interrupts when large sample
    periods are specified.
 
  - Extends Family 17h RAPL support to also work on compatible
    F19h machines.
 
 Core code updates:
 
  - Fix race in perf_mmap_close()
 
  - Add PERF_EV_CAP_SIBLING, to denote that sibling events should be
    closed if the leader is removed.
 
  - Smaller fixes and updates.
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'perf-core-2020-10-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull performance events updates from Ingo Molnar:
 "x86 Intel updates:

   - Add Jasper Lake support

   - Add support for TopDown metrics on Ice Lake

   - Fix Ice Lake & Tiger Lake uncore support, add Snow Ridge support

   - Add a PCI sub driver to support uncore PMUs where the PCI resources
     have been claimed already - extending the range of supported
     systems.

  x86 AMD updates:

   - Restore 'perf stat -a' behaviour to program the uncore PMU to count
     all CPU threads.

   - Fix setting the proper count when sampling Large Increment per
     Cycle events / 'paired' events.

   - Fix IBS Fetch sampling on F17h and some other IBS fine tuning,
     greatly reducing the number of interrupts when large sample periods
     are specified.

   - Extends Family 17h RAPL support to also work on compatible F19h
     machines.

  Core code updates:

   - Fix race in perf_mmap_close()

   - Add PERF_EV_CAP_SIBLING, to denote that sibling events should be
     closed if the leader is removed.

   - Smaller fixes and updates"

* tag 'perf-core-2020-10-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (45 commits)
  perf/core: Fix race in the perf_mmap_close() function
  perf/x86: Fix n_metric for cancelled txn
  perf/x86: Fix n_pair for cancelled txn
  x86/events/amd/iommu: Fix sizeof mismatch
  perf/x86/intel: Check perf metrics feature for each CPU
  perf/x86/intel: Fix Ice Lake event constraint table
  perf/x86/intel/uncore: Fix the scale of the IMC free-running events
  perf/x86/intel/uncore: Fix for iio mapping on Skylake Server
  perf/x86/msr: Add Jasper Lake support
  perf/x86/intel: Add Jasper Lake support
  perf/x86/intel/uncore: Reduce the number of CBOX counters
  perf/x86/intel/uncore: Update Ice Lake uncore units
  perf/x86/intel/uncore: Split the Ice Lake and Tiger Lake MSR uncore support
  perf/x86/intel/uncore: Support PCIe3 unit on Snow Ridge
  perf/x86/intel/uncore: Generic support for the PCI sub driver
  perf/x86/intel/uncore: Factor out uncore_pci_pmu_unregister()
  perf/x86/intel/uncore: Factor out uncore_pci_pmu_register()
  perf/x86/intel/uncore: Factor out uncore_pci_find_dev_pmu()
  perf/x86/intel/uncore: Factor out uncore_pci_get_dev_die_info()
  perf/amd/uncore: Inform the user how many counters each uncore PMU has
  ...
2020-10-12 14:14:35 -07:00
Linus Torvalds dd502a8107 This tree introduces static_call(), which is the idea of static_branch()
applied to indirect function calls. Remove a data load (indirection) by
 modifying the text.
 
 They give the flexibility of function pointers, but with better
 performance. (This is especially important for cases where
 retpolines would otherwise be used, as retpolines can be pretty
 slow.)
 
 API overview:
 
   DECLARE_STATIC_CALL(name, func);
   DEFINE_STATIC_CALL(name, func);
   DEFINE_STATIC_CALL_NULL(name, typename);
 
   static_call(name)(args...);
   static_call_cond(name)(args...);
   static_call_update(name, func);
 
 x86 is supported via text patching, otherwise basic indirect calls are used,
 with function pointers.
 
 There's a second variant using inline code patching, inspired by jump-labels,
 implemented on x86 as well.
 
 The new APIs are utilized in the x86 perf code, a heavy user of function pointers,
 where static calls speed up the PMU handler by 4.2% (!).
 
 The generic implementation is not really excercised on other architectures,
 outside of the trivial test_static_call_init() self-test.
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'core-static_call-2020-10-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull static call support from Ingo Molnar:
 "This introduces static_call(), which is the idea of static_branch()
  applied to indirect function calls. Remove a data load (indirection)
  by modifying the text.

  They give the flexibility of function pointers, but with better
  performance. (This is especially important for cases where retpolines
  would otherwise be used, as retpolines can be pretty slow.)

  API overview:

      DECLARE_STATIC_CALL(name, func);
      DEFINE_STATIC_CALL(name, func);
      DEFINE_STATIC_CALL_NULL(name, typename);

      static_call(name)(args...);
      static_call_cond(name)(args...);
      static_call_update(name, func);

  x86 is supported via text patching, otherwise basic indirect calls are
  used, with function pointers.

  There's a second variant using inline code patching, inspired by
  jump-labels, implemented on x86 as well.

  The new APIs are utilized in the x86 perf code, a heavy user of
  function pointers, where static calls speed up the PMU handler by
  4.2% (!).

  The generic implementation is not really excercised on other
  architectures, outside of the trivial test_static_call_init()
  self-test"

* tag 'core-static_call-2020-10-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (21 commits)
  static_call: Fix return type of static_call_init
  tracepoint: Fix out of sync data passing by static caller
  tracepoint: Fix overly long tracepoint names
  x86/perf, static_call: Optimize x86_pmu methods
  tracepoint: Optimize using static_call()
  static_call: Allow early init
  static_call: Add some validation
  static_call: Handle tail-calls
  static_call: Add static_call_cond()
  x86/alternatives: Teach text_poke_bp() to emulate RET
  static_call: Add simple self-test for static calls
  x86/static_call: Add inline static call implementation for x86-64
  x86/static_call: Add out-of-line static call implementation
  static_call: Avoid kprobes on inline static_call()s
  static_call: Add inline static call infrastructure
  static_call: Add basic static call infrastructure
  compiler.h: Make __ADDRESSABLE() symbol truly unique
  jump_label,module: Fix module lifetime for __jump_label_mod_text_reserved()
  module: Properly propagate MODULE_STATE_COMING failure
  module: Fix up module_notifier return values
  ...
2020-10-12 13:58:15 -07:00
Peter Zijlstra d741bf41d7 kprobes: Remove kretprobe hash
The kretprobe hash is mostly superfluous, replace it with a per-task
variable.

This gets rid of the task hash and it's related locking.

Note that this may change the kprobes module-exported API for kretprobe
handlers. If any out-of-tree kretprobe user uses ri->rp, use
get_kretprobe(ri) instead.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/159870620431.1229682.16325792502413731312.stgit@devnote2
2020-10-12 18:27:27 +02:00
Steven Rostedt (VMware) 848183553e tracing: Fix synthetic print fmt check for use of __get_str()
A cut and paste error had the check to use __get_str() test "is_dynamic"
twice, instead of checking "is_string && is_dynamic".

Link: https://lore.kernel.org/r/d34dccd5-96ba-a2d9-46ea-de8807525deb@canonical.com

Reported-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-10-08 15:29:07 -04:00
Sudip Mukherjee 43aa422c0c tracing: Remove a pointless assignment
The variable 'len' has been assigned a value but is not used after that.
So, remove the assignement.

Link: https://lkml.kernel.org/r/20200930184303.22896-1-sudipm.mukherjee@gmail.com

Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-10-08 15:29:06 -04:00
Steven Rostedt (VMware) 7ba031e8b7 ftrace: Format variable declarations of ftrace_allocate_records
I hate when unrelated variables are declared on the same line.
Split them.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-10-08 15:29:06 -04:00
Wei Yang b40c6eabfc ftrace: Simplify the calculation of page number for ftrace_page->records
Based on the following two reasones, we could simplify the calculation:

  - If the number after roundup count is not power of 2, we would
    definitely have more than 1 empty page with a higher order.
  - get_count_order() just return current order, so one lower order
    could meet the requirement.

The calculation could be simplified by lower one order level when pages
are not power of 2.

Link: https://lkml.kernel.org/r/20200831031104.23322-5-richard.weiyang@linux.alibaba.com

Signed-off-by: Wei Yang <richard.weiyang@linux.alibaba.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-10-08 15:29:06 -04:00
Steven Rostedt (VMware) be49313273 ftrace: Simplify the hash calculation
No need to add a check to subtract the number of bits if bits is zero after
fls(). Just divide the size by two before calling it. This does give the
same answer for size of 0 and 1, but that's fine.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-10-08 15:29:06 -04:00
Wei Yang 59e65b3358 ftrace: Use fls() to get the bits for dup_hash()
The effect here is to get the number of bits, lets use fls() to do
this job.

Link: https://lkml.kernel.org/r/20200831031104.23322-3-richard.weiyang@linux.alibaba.com

Signed-off-by: Wei Yang <richard.weiyang@linux.alibaba.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-10-08 15:29:06 -04:00
Steven Rostedt (VMware) 8db4d6bfbb tracing: Change synthetic event string format to limit printed length
Change the format for printing synthetic field strings to limit the
length of the string printed even if it's not correctly terminated.

Link: https://lore.kernel.org/r/20201002210036.0200371b@oasis.local.home
Link: https://lkml.kernel.org/r/b6bdb34e70d970e8026daa3503db6b8e5cdad524.1601848695.git.zanussi@kernel.org

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-10-08 15:29:06 -04:00
Tom Zanussi 1bc36bd4a8 tracing: Add README information for synthetic_events file
Add an entry with a basic description of events/synthetic_events along
with a simple example.

Link: https://lkml.kernel.org/r/3c7f178cf95aaeebc01eda7d95600dd937233eb7.1601848695.git.zanussi@kernel.org

Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-10-08 15:28:14 -04:00
Yonghong Song ebfb4d40ed bpf: Fix build failure for kernel/trace/bpf_trace.c with CONFIG_NET=n
When CONFIG_NET is not defined, I hit the following build error:
    kernel/trace/bpf_trace.o:(.rodata+0x110): undefined reference to `bpf_prog_test_run_raw_tp'

Commit 1b4d60ec16 ("bpf: Enable BPF_PROG_TEST_RUN for raw_tracepoint")
added test_run support for raw_tracepoint in /kernel/trace/bpf_trace.c.
But the test_run function bpf_prog_test_run_raw_tp is defined in
net/bpf/test_run.c, only available with CONFIG_NET=y.

Adding a CONFIG_NET guard for
    .test_run = bpf_prog_test_run_raw_tp;
fixed the above build issue.

Fixes: 1b4d60ec16 ("bpf: Enable BPF_PROG_TEST_RUN for raw_tracepoint")
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20201007062933.3425899-1-yhs@fb.com
2020-10-07 10:56:46 -07:00
David S. Miller 8b0308fe31 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Rejecting non-native endian BTF overlapped with the addition
of support for it.

The rest were more simple overlapping changes, except the
renesas ravb binding update, which had to follow a file
move as well as a YAML conversion.

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-10-05 18:40:01 -07:00
Tom Zanussi bd82631d7c tracing: Add support for dynamic strings to synthetic events
Currently, sythetic events only support static string fields such as:

  # echo 'test_latency u64 lat; char somename[32]' > /sys/kernel/debug/tracing/synthetic_events

Which is fine, but wastes a lot of space in the event.

It also prevents the most commonly-defined strings in the existing
trace events e.g. those defined using __string(), from being passed to
synthetic events via the trace() action.

With this change, synthetic events with dynamic fields can be defined:

  # echo 'test_latency u64 lat; char somename[]' > /sys/kernel/debug/tracing/synthetic_events

And the trace() action can be used to generate events using either
dynamic or static strings:

  # echo 'hist:keys=name:lat=common_timestamp.usecs-$ts0:onmatch(sys.event).test_latency($lat,name)' > /sys/kernel/debug/tracing/events

The synthetic event dynamic strings are implemented in the same way as
the existing __data_loc strings and appear as such in the format file.

[ <rostedt@goodmis.org>: added __set_synth_event_print_fmt() changes:

  I added the following to make it work with trace-cmd. Dynamic strings
  must have __get_str() for events in the print_fmt otherwise it can't be
  parsed correctly. ]

Link: https://lore.kernel.org/r/cover.1601588066.git.zanussi@kernel.org
Link: https://lkml.kernel.org/r/3ed35b6d0e390f5b94cb4a9ba1cc18f5982ab277.1601848695.git.zanussi@kernel.org

Tested-by: Axel Rasmussen <axelrasmussen@google.com>
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-10-05 19:32:18 -04:00
Tom Zanussi 63a1e5de30 tracing: Save normal string variables
String variables created as field variables and save variables are
already handled properly by having their values copied when set.  The
same isn't done for normal variables, but needs to be - simply saving
a pointer to a string contained in an old event isn't sufficient,
since that event's data may quickly become overwritten and therefore a
string pointer to it could yield garbage.

This change uses the same mechanism as field variables and simply
appends the new strings to the existing per-element field_var_str[]
array allocated for that purpose.

Link: https://lkml.kernel.org/r/1c1a03798b02e67307412a0c719d1bfb69b13007.1601848695.git.zanussi@kernel.org

Fixes: 02205a6752 (tracing: Add support for 'field variables')
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-10-05 18:13:53 -04:00
Tom Zanussi 8fbeb52a59 tracing: Fix parse_synth_field() error handling
synth_field_size() returns either a positive size or an error (zero or
a negative value). However, the existing code assumes the only error
value is 0. It doesn't handle negative error codes, as it assigns
directly to field->size (a size_t; unsigned), thereby interpreting the
error code as a valid size instead.

Do the test before assignment to field->size.

[ axelrasmussen@google.com: changelog addition, first paragraph above ]

Link: https://lkml.kernel.org/r/9b6946d9776b2eeb43227678158196de1c3c6e1d.1601848695.git.zanussi@kernel.org

Fixes: 4b147936fa (tracing: Add support for 'synthetic' events)
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Tested-by: Axel Rasmussen <axelrasmussen@google.com>
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-10-05 18:13:53 -04:00
Tom Zanussi 4a4a56b4e7 tracing: Change STR_VAR_MAX_LEN
32 is too small for this value, and anyway it makes more sense to use
MAX_FILTER_STR_VAL, as this is also the value used for variable-length
__strings.

Link: https://lkml.kernel.org/r/6adfd1668ac1fd8670bd58206944a762061a5559.1601848695.git.zanussi@kernel.org

Tested-by: Axel Rasmussen <axelrasmussen@google.com>
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-10-05 18:13:53 -04:00
Christoph Hellwig 10ed16662d block: add a bdget_part helper
All remaining callers of bdget() outside of fs/block_dev.c want to get a
reference to the struct block_device for a given struct hd_struct.  Add
a helper just for that and then mark bdget static.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-05 10:38:33 -06:00
Tingwei Zhang 458999c6f6 tracing: Add trace_export support for trace_marker
Add the support to route trace_marker buffer to other destination
via trace_export.

Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Reviewed-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Tingwei Zhang <tingwei@codeaurora.org>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Link: https://lore.kernel.org/r/20201005071319.78508-5-alexander.shishkin@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-10-05 12:43:53 +02:00
Tingwei Zhang 8ab7a2b705 tracing: Add trace_export support for event trace
Only function traces can be exported to other destinations currently.
This patch exports event trace as well. Move trace export related
function to the beginning of file so other trace can call
trace_process_export() to export.

Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Reviewed-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Tingwei Zhang <tingwei@codeaurora.org>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Link: https://lore.kernel.org/r/20201005071319.78508-4-alexander.shishkin@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-10-05 12:43:53 +02:00
Tingwei Zhang 8438f52114 tracing: Add flag to control different traces
More traces like event trace or trace marker will be supported.
Add flag for difference traces, so that they can be controlled
separately. Move current function trace to it's own flag
instead of global ftrace enable flag.

Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Reviewed-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Tingwei Zhang <tingwei@codeaurora.org>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Link: https://lore.kernel.org/r/20201005071319.78508-3-alexander.shishkin@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-10-05 12:43:53 +02:00
Hao Luo 63d9b80dcf bpf: Introducte bpf_this_cpu_ptr()
Add bpf_this_cpu_ptr() to help access percpu var on this cpu. This
helper always returns a valid pointer, therefore no need to check
returned value for NULL. Also note that all programs run with
preemption disabled, which means that the returned pointer is stable
during all the execution of the program.

Signed-off-by: Hao Luo <haoluo@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200929235049.2533242-6-haoluo@google.com
2020-10-02 15:00:49 -07:00
Hao Luo eaa6bcb71e bpf: Introduce bpf_per_cpu_ptr()
Add bpf_per_cpu_ptr() to help bpf programs access percpu vars.
bpf_per_cpu_ptr() has the same semantic as per_cpu_ptr() in the kernel
except that it may return NULL. This happens when the cpu parameter is
out of range. So the caller must check the returned value.

Signed-off-by: Hao Luo <haoluo@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200929235049.2533242-5-haoluo@google.com
2020-10-02 15:00:49 -07:00
Qiujun Huang fdda88d31a ftrace: Fix some typos in comment
s/coorditate/coordinate/
s/emty/empty/
s/preeptive/preemptive/
s/succes/success/
s/carefule/careful/

Link: https://lkml.kernel.org/r/20201002143126.2890-1-hqjagain@gmail.com

Signed-off-by: Qiujun Huang <hqjagain@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-10-02 14:05:48 -04:00
Linus Torvalds aa5ff93523 Two tracing fixes:
- Fix temp buffer accounting that caused a WARNING for
   ftrace_dump_on_opps()
 
 - Move the recursion check in one of the function callback helpers to the
   beginning of the function, as if the rcu_is_watching() gets traced, it
   will cause a recursive loop that will crash the kernel.
 -----BEGIN PGP SIGNATURE-----
 
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 b29kbWlzLm9yZwAKCRAp5XQQmuv6qlelAP4nzEIyE7s8HkKHo+IEvzEiYL523Xq7
 zrTm27XnLjZ+EQD9ECbtea9me8kL+zBcG8H3Wu/ykN15LIT2ZsvVTrWYmwI=
 =eTh4
 -----END PGP SIGNATURE-----

Merge tag 'trace-v5.9-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixes from Steven Rostedt:
 "Two tracing fixes:

   - Fix temp buffer accounting that caused a WARNING for
     ftrace_dump_on_opps()

   - Move the recursion check in one of the function callback helpers to
     the beginning of the function, as if the rcu_is_watching() gets
     traced, it will cause a recursive loop that will crash the kernel"

* tag 'trace-v5.9-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  ftrace: Move RCU is watching check after recursion check
  tracing: Fix trace_find_next_entry() accounting of temp buffer size
2020-10-01 09:41:02 -07:00
Steven Rostedt (VMware) b40341fad6 ftrace: Move RCU is watching check after recursion check
The first thing that the ftrace function callback helper functions should do
is to check for recursion. Peter Zijlstra found that when
"rcu_is_watching()" had its notrace removed, it caused perf function tracing
to crash. This is because the call of rcu_is_watching() is tested before
function recursion is checked and and if it is traced, it will cause an
infinite recursion loop.

rcu_is_watching() should still stay notrace, but to prevent this should
never had crashed in the first place. The recursion prevention must be the
first thing done in callback functions.

Link: https://lore.kernel.org/r/20200929112541.GM2628@hirez.programming.kicks-ass.net

Cc: stable@vger.kernel.org
Cc: Paul McKenney <paulmck@kernel.org>
Fixes: c68c0fa293 ("ftrace: Have ftrace_ops_get_func() handle RCU and PER_CPU flags too")
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reported-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-09-29 13:05:10 -04:00
Steven Rostedt (VMware) 851e6f61cd tracing: Fix trace_find_next_entry() accounting of temp buffer size
The temp buffer size variable for trace_find_next_entry() was incorrectly
being updated when the size did not change. The temp buffer size should only
be updated when it is reallocated.

This is mostly an issue when used with ftrace_dump(). That's because
ftrace_dump() can not allocate a new buffer, and instead uses a temporary
buffer with a fix size. But the variable that keeps track of that size is
incorrectly updated with each call, and it could fall into the path that
would try to reallocate the buffer and produce a warning.

 ------------[ cut here ]------------
 WARNING: CPU: 1 PID: 1601 at kernel/trace/trace.c:3548
trace_find_next_entry+0xd0/0xe0
 Modules linked in [..]
 CPU: 1 PID: 1601 Comm: bash Not tainted 5.9.0-rc5-test+ #521
 Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01 v03.03
07/14/2016
 RIP: 0010:trace_find_next_entry+0xd0/0xe0
 Code: 40 21 00 00 4c 89 e1 31 d2 4c 89 ee 48 89 df e8 c6 9e ff ff 89 ab 54
21 00 00 5b 5d 41 5c 41 5d c3 48 63 d5 eb bf 31 c0 eb f0 <0f> 0b 48 63 d5 eb
b4 66 0f 1f 84 00 00 00 00 00 53 48 8d 8f 60 21
 RSP: 0018:ffff95a4f2e8bd70 EFLAGS: 00010046
 RAX: ffffffff96679fc0 RBX: ffffffff97910de0 RCX: ffffffff96679fc0
 RDX: ffff95a4f2e8bd98 RSI: ffff95a4ee321098 RDI: ffffffff97913000
 RBP: 0000000000000018 R08: 0000000000000000 R09: 0000000000000000
 R10: 0000000000000001 R11: 0000000000000046 R12: ffff95a4f2e8bd98
 R13: 0000000000000000 R14: ffff95a4ee321098 R15: 00000000009aa301
 FS:  00007f8565484740(0000) GS:ffff95a55aa40000(0000)
knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 000055876bd43d90 CR3: 00000000b76e6003 CR4: 00000000001706e0
 Call Trace:
  trace_print_lat_context+0x58/0x2d0
  ? cpumask_next+0x16/0x20
  print_trace_line+0x1a4/0x4f0
  ftrace_dump.cold+0xad/0x12c
  __handle_sysrq.cold+0x51/0x126
  write_sysrq_trigger+0x3f/0x4a
  proc_reg_write+0x53/0x80
  vfs_write+0xca/0x210
  ksys_write+0x70/0xf0
  do_syscall_64+0x33/0x40
  entry_SYSCALL_64_after_hwframe+0x44/0xa9
 RIP: 0033:0x7f8565579487
 Code: 64 89 02 48 c7 c0 ff ff ff ff eb bb 0f 1f 80 00 00 00 00 f3 0f 1e fa
64 8b 04 25 18 00 00 00 85 c0 75 10 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff
77 51 c3 48 83 ec 28 48 89 54 24 18 48 89 74 24
 RSP: 002b:00007ffd40707948 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
 RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f8565579487
 RDX: 0000000000000002 RSI: 000055876bd74de0 RDI: 0000000000000001
 RBP: 000055876bd74de0 R08: 000000000000000a R09: 0000000000000001
 R10: 000055876bdec280 R11: 0000000000000246 R12: 0000000000000002
 R13: 00007f856564a500 R14: 0000000000000002 R15: 00007f856564a700
 irq event stamp: 109958
 ---[ end trace 7aab5b7e51484b00 ]---

Not only fix the updating of the temp buffer, but also do not free the temp
buffer before a new buffer is allocated (there's no reason to not continue
to use the current temp buffer if an allocation fails).

Cc: stable@vger.kernel.org
Fixes: 8e99cf91b9 ("tracing: Do not allocate buffer in trace_find_next_entry() in atomic")
Reported-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-09-29 12:46:22 -04:00
Alan Maguire eb411377ae bpf: Add bpf_seq_printf_btf helper
A helper is added to allow seq file writing of kernel data
structures using vmlinux BTF.  Its signature is

long bpf_seq_printf_btf(struct seq_file *m, struct btf_ptr *ptr,
                        u32 btf_ptr_size, u64 flags);

Flags and struct btf_ptr definitions/use are identical to the
bpf_snprintf_btf helper, and the helper returns 0 on success
or a negative error value.

Suggested-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/1601292670-1616-8-git-send-email-alan.maguire@oracle.com
2020-09-28 18:26:58 -07:00
Alan Maguire c4d0bfb450 bpf: Add bpf_snprintf_btf helper
A helper is added to support tracing kernel type information in BPF
using the BPF Type Format (BTF).  Its signature is

long bpf_snprintf_btf(char *str, u32 str_size, struct btf_ptr *ptr,
		      u32 btf_ptr_size, u64 flags);

struct btf_ptr * specifies

- a pointer to the data to be traced
- the BTF id of the type of data pointed to
- a flags field is provided for future use; these flags
  are not to be confused with the BTF_F_* flags
  below that control how the btf_ptr is displayed; the
  flags member of the struct btf_ptr may be used to
  disambiguate types in kernel versus module BTF, etc;
  the main distinction is the flags relate to the type
  and information needed in identifying it; not how it
  is displayed.

For example a BPF program with a struct sk_buff *skb
could do the following:

	static struct btf_ptr b = { };

	b.ptr = skb;
	b.type_id = __builtin_btf_type_id(struct sk_buff, 1);
	bpf_snprintf_btf(str, sizeof(str), &b, sizeof(b), 0, 0);

Default output looks like this:

(struct sk_buff){
 .transport_header = (__u16)65535,
 .mac_header = (__u16)65535,
 .end = (sk_buff_data_t)192,
 .head = (unsigned char *)0x000000007524fd8b,
 .data = (unsigned char *)0x000000007524fd8b,
 .truesize = (unsigned int)768,
 .users = (refcount_t){
  .refs = (atomic_t){
   .counter = (int)1,
  },
 },
}

Flags modifying display are as follows:

- BTF_F_COMPACT:	no formatting around type information
- BTF_F_NONAME:		no struct/union member names/types
- BTF_F_PTR_RAW:	show raw (unobfuscated) pointer values;
			equivalent to %px.
- BTF_F_ZERO:		show zero-valued struct/union members;
			they are not displayed by default

Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/1601292670-1616-4-git-send-email-alan.maguire@oracle.com
2020-09-28 18:26:58 -07:00
Song Liu 1b4d60ec16 bpf: Enable BPF_PROG_TEST_RUN for raw_tracepoint
Add .test_run for raw_tracepoint. Also, introduce a new feature that runs
the target program on a specific CPU. This is achieved by a new flag in
bpf_attr.test, BPF_F_TEST_RUN_ON_CPU. When this flag is set, the program
is triggered on cpu with id bpf_attr.test.cpu. This feature is needed for
BPF programs that handle perf_event and other percpu resources, as the
program can access these resource locally.

Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200925205432.1777-2-songliubraving@fb.com
2020-09-28 21:52:36 +02:00
Masami Hiramatsu 720dee53ad tracing/boot: Initialize per-instance event list in early boot
Initialize per-instance event list in early boot time (before
initializing instance directory on tracefs). This fixes boot-time
tracing to correctly handle the boot-time per-instance settings.

Link: https://lkml.kernel.org/r/160096560826.182763.17110991546046128881.stgit@devnote2

Fixes: 4114fbfd02 ("tracing: Enable creating new instance early boot")
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-09-25 15:36:03 -04:00
Christoph Hellwig fa01b1e973 block: add a bdev_is_partition helper
Add a littler helper to make the somewhat arcane bd_contains checks a
little more obvious.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-25 08:18:57 -06:00
Jarkko Sakkinen e9ffc8c1b8 kprobes: Use module_name() macro
It is advised to use module_name() macro instead of dereferencing mod->name
directly. This makes sense for consistencys sake and also it prevents a
hard dependency to CONFIG_MODULES.

Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Link: https://lkml.kernel.org/r/20200818050857.117998-1-jarkko.sakkinen@linux.intel.com
2020-09-24 15:55:49 +02:00
David S. Miller 6d772f328d Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Alexei Starovoitov says:

====================
pull-request: bpf-next 2020-09-23

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

We've added 95 non-merge commits during the last 22 day(s) which contain
a total of 124 files changed, 4211 insertions(+), 2040 deletions(-).

The main changes are:

1) Full multi function support in libbpf, from Andrii.

2) Refactoring of function argument checks, from Lorenz.

3) Make bpf_tail_call compatible with functions (subprograms), from Maciej.

4) Program metadata support, from YiFei.

5) bpf iterator optimizations, from Yonghong.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-23 13:11:11 -07:00
David S. Miller 3ab0a7a0c3 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Two minor conflicts:

1) net/ipv4/route.c, adding a new local variable while
   moving another local variable and removing it's
   initial assignment.

2) drivers/net/dsa/microchip/ksz9477.c, overlapping changes.
   One pretty prints the port mode differently, whilst another
   changes the driver to try and obtain the port mode from
   the port node rather than the switch node.

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-22 16:45:34 -07:00
Linus Torvalds eff48ddeab Tracing fixes:
- Check kprobe is enabled before unregistering from ftrace as it isn't
   registered when disabled.
 
 - Remove kprobes enabled via command-line that is on init text when freed.
 
 - Add missing RCU synchronization for ftrace trampoline symbols removed
   from kallsyms.
 
 - Free trampoline on error path if ftrace_startup() fails.
 
 - Give more space for the longer PID numbers in trace output.
 
 - Fix a possible double free in the histogram code.
 
 - A couple of fixes that were discovered by sparse.
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Merge tag 'trace-v5.9-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixes from Steven Rostedt:

 - Check kprobe is enabled before unregistering from ftrace as it isn't
   registered when disabled.

 - Remove kprobes enabled via command-line that is on init text when
   freed.

 - Add missing RCU synchronization for ftrace trampoline symbols removed
   from kallsyms.

 - Free trampoline on error path if ftrace_startup() fails.

 - Give more space for the longer PID numbers in trace output.

 - Fix a possible double free in the histogram code.

 - A couple of fixes that were discovered by sparse.

* tag 'trace-v5.9-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  bootconfig: init: make xbc_namebuf static
  kprobes: tracing/kprobes: Fix to kill kprobes on initmem after boot
  tracing: fix double free
  ftrace: Let ftrace_enable_sysctl take a kernel pointer buffer
  tracing: Make the space reserved for the pid wider
  ftrace: Fix missing synchronize_rcu() removing trampoline from kallsyms
  ftrace: Free the trampoline when ftrace_startup() fails
  kprobes: Fix to check probe enabled before disarm_kprobe_ftrace()
2020-09-22 09:08:33 -07:00
Masami Hiramatsu ba0fbfbb21 tracing/boot, kprobe, synth: Initialize boot-time tracing earlier
Initialize boot-time tracing in core_initcall_sync instead of
fs_initcall, and initialize required tracers (kprobes and synth)
in core_initcall. This will allow the boot-time tracing to trace
__init code from the beginning of postcore_initcall stage.

Link: https://lkml.kernel.org/r/159974155727.478751.7486926132902849578.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-09-21 21:06:04 -04:00
Masami Hiramatsu 4114fbfd02 tracing: Enable creating new instance early boot
Enable creating new trace_array instance in early boot stage.
If the instances directory is not created, postpone it until
the tracefs is initialized.

Link: https://lkml.kernel.org/r/159974154763.478751.6289753509587233103.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-09-21 21:06:04 -04:00
Masami Hiramatsu a838deab4e tracing: Enable adding dynamic events early stage
Split the event fields initialization from creating new event directory.
This allows the boot-time tracing to define dynamic events before
initializing events directory on tracefs.

Link: https://lkml.kernel.org/r/159974153790.478751.3475515065034825374.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-09-21 21:06:04 -04:00
Masami Hiramatsu ac343da7bc tracing: Define event fields early stage
Define event fields at early stage so that boot-time tracing can
access the event fields (like per-event filter setting).

Link: https://lkml.kernel.org/r/159974152862.478751.2023768466808361350.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-09-21 21:06:04 -04:00
Masami Hiramatsu 3dd3aae32d tracing/uprobes: Support perf-style return probe
Support perf-style return probe ("SYMBOL%return") for uprobe events
as same as kprobe events does.

Link: https://lkml.kernel.org/r/159972814601.428528.7641183316212425445.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-09-21 21:06:03 -04:00
Masami Hiramatsu 4725cd8997 tracing/kprobes: Support perf-style return probe
Support perf-style return probe ("SYMBOL%return") for kprobe events.
This will allow boot-time tracing user to define a return probe event.

Link: https://lkml.kernel.org/r/159972813535.428528.4437029657208468954.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-09-21 21:06:03 -04:00
Masami Hiramatsu 8490db06f9 tracing/boot: Add per-instance tracing_on option support
Add per-instance tracing_on option, which will be useful with
traceon/traceoff event trigger actions. For example, if we
disable tracing_on by default and set traceon and traceoff on
a pair of events, we can trace functions between the pair of
events.

Link: https://lkml.kernel.org/r/159972811538.428528.2561315102284268611.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-09-21 21:06:03 -04:00
Davidlohr Bueso 40d14da383 fgraph: Convert ret_stack tasklist scanning to rcu
It seems that alloc_retstack_tasklist() can also take a lockless
approach for scanning the tasklist, instead of using the big global
tasklist_lock. For this we also kill another deprecated and rcu-unsafe
tsk->thread_group user replacing it with for_each_process_thread(),
maintaining semantics.

Here tasklist_lock does not protect anything other than the list
against concurrent fork/exit. And considering that the whole thing
is capped by FTRACE_RETSTACK_ALLOC_SIZE (32), it should not be a
problem to have a pontentially stale, yet stable, list. The task cannot
go away either, so we don't risk racing with ftrace_graph_exit_task()
which clears the retstack.

The tsk->ret_stack management is not protected by tasklist_lock, being
serialized with the corresponding publish/subscribe barriers against
concurrent ftrace_push_return_trace(). In addition this plays nicer
with cachelines by avoiding two atomic ops in the uncontended case.

Link: https://lkml.kernel.org/r/20200907013326.9870-1-dave@stgolabs.net

Acked-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-09-21 21:06:02 -04:00
Dan Carpenter eb8d8b4c98 tracing: remove a pointless assignment
The "tr" is a stack variable so setting it to NULL before a return is
a no-op.  Delete the assignment.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-09-21 21:06:02 -04:00
Jarkko Sakkinen f3d3642661 kprobes: Use module_name() macro
It is advised to use module_name() macro instead of dereferencing mod->name
directly. This makes sense for consistencys sake and also it prevents a
hard dependency to CONFIG_MODULES.

Link: https://lkml.kernel.org/r/20200818050857.117998-1-jarkko.sakkinen@linux.intel.com

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: linux-mm@kvack.org
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Jessica Yu <jeyu@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>,
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Will Deacon <will@kernel.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-09-21 21:06:02 -04:00
Xianting Tian b427e765bd tracing: Use __this_cpu_read() in trace_buffered_event_enable()
The code is executed with preemption disabled, so it's
safe to use __this_cpu_read().

Link: https://lkml.kernel.org/r/20200813112803.12256-1-tian.xianting@h3c.com

Signed-off-by: Xianting Tian <tian.xianting@h3c.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-09-21 21:06:02 -04:00
Randy Dunlap 5c8c206e43 tracing: Delete repeated words in comments
Drop repeated words in kernel/trace/.
{and, the, not}

Link: https://lkml.kernel.org/r/20200807033259.13778-1-rdunlap@infradead.org

Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-09-21 21:06:02 -04:00
Jiri Olsa a8a717963f selftests/bpf: Fix stat probe in d_path test
Some kernels builds might inline vfs_getattr call within fstat
syscall code path, so fentry/vfs_getattr trampoline is not called.

Add security_inode_getattr to allowlist and switch the d_path test stat
trampoline to security_inode_getattr.

Keeping dentry_open and filp_close, because they are in their own
files, so unlikely to be inlined, but in case they are, adding
security_file_open.

Adding flags that indicate trampolines were called and failing
the test if any of them got missed, so it's easier to identify
the issue next time.

Fixes: e4d1af4b16 ("selftests/bpf: Add test for d_path helper")
Suggested-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200918112338.2618444-1-jolsa@kernel.org
2020-09-21 16:18:00 -07:00
Lorenz Bauer 9436ef6e86 bpf: Allow specifying a BTF ID per argument in function protos
Function prototypes using ARG_PTR_TO_BTF_ID currently use two ways to signal
which BTF IDs are acceptable. First, bpf_func_proto.btf_id is an array of
IDs, one for each argument. This array is only accessed up to the highest
numbered argument that uses ARG_PTR_TO_BTF_ID and may therefore be less than
five arguments long. It usually points at a BTF_ID_LIST. Second, check_btf_id
is a function pointer that is called by the verifier if present. It gets the
actual BTF ID of the register, and the argument number we're currently checking.
It turns out that the only user check_arg_btf_id ignores the argument, and is
simply used to check whether the BTF ID has a struct sock_common at it's start.

Replace both of these mechanisms with an explicit BTF ID for each argument
in a function proto. Thanks to btf_struct_ids_match this is very flexible:
check_arg_btf_id can be replaced by requiring struct sock_common.

Signed-off-by: Lorenz Bauer <lmb@cloudflare.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20200921121227.255763-5-lmb@cloudflare.com
2020-09-21 15:00:40 -07:00
Linus Torvalds 325d0eab4f Merge branch 'akpm' (patches from Andrew)
Merge fixes from Andrew Morton:
 "15 patches.

  Subsystems affected by this patch series: mailmap, mm/hotfixes,
  mm/thp, mm/memory-hotplug, misc, kcsan"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  kcsan: kconfig: move to menu 'Generic Kernel Debugging Instruments'
  fs/fs-writeback.c: adjust dirtytime_interval_handler definition to match prototype
  stackleak: let stack_erasing_sysctl take a kernel pointer buffer
  ftrace: let ftrace_enable_sysctl take a kernel pointer buffer
  mm/memory_hotplug: drain per-cpu pages again during memory offline
  selftests/vm: fix display of page size in map_hugetlb
  mm/thp: fix __split_huge_pmd_locked() for migration PMD
  kprobes: fix kill kprobe which has been marked as gone
  tmpfs: restore functionality of nr_inodes=0
  mlock: fix unevictable_pgs event counts on THP
  mm: fix check_move_unevictable_pages() on THP
  mm: migration of hugetlbfs page skip memcg
  ksm: reinstate memcg charge on copied pages
  mailmap: add older email addresses for Kees Cook
2020-09-19 18:18:37 -07:00
Tobias Klauser 7bb82ac30c ftrace: let ftrace_enable_sysctl take a kernel pointer buffer
Commit 32927393dc ("sysctl: pass kernel pointers to ->proc_handler")
changed ctl_table.proc_handler to take a kernel pointer.  Adjust the
signature of ftrace_enable_sysctl to match ctl_table.proc_handler which
fixes the following sparse warning:

kernel/trace/ftrace.c:7544:43: warning: incorrect type in argument 3 (different address spaces)
kernel/trace/ftrace.c:7544:43:    expected void *
kernel/trace/ftrace.c:7544:43:    got void [noderef] __user *buffer

Fixes: 32927393dc ("sysctl: pass kernel pointers to ->proc_handler")
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Link: https://lkml.kernel.org/r/20200907093207.13540-1-tklauser@distanz.ch
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-09-19 13:13:39 -07:00
Wei Yang 22c36b1826 tracing: make tracing_init_dentry() returns an integer instead of a d_entry pointer
Current tracing_init_dentry() return a d_entry pointer, while is not
necessary. This function returns NULL on success or error on failure,
which means there is no valid d_entry pointer return.

Let's return 0 on success and negative value for error.

Link: https://lkml.kernel.org/r/20200712011036.70948-5-richard.weiyang@linux.alibaba.com

Signed-off-by: Wei Yang <richard.weiyang@linux.alibaba.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-09-18 22:17:14 -04:00
Wei Yang dc300d77b8 tracing: toplevel d_entry already initialized
Currently we have following call flow:

    tracer_init_tracefs()
        tracing_init_dentry()
        event_trace_init()
            tracing_init_dentry()

This shows tracing_init_dentry() is called twice in this flow and this
is not necessary.

Let's remove the second one when it is for sure be properly initialized.

Link: https://lkml.kernel.org/r/20200712011036.70948-4-richard.weiyang@linux.alibaba.com

Signed-off-by: Wei Yang <richard.weiyang@linux.alibaba.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-09-18 22:17:14 -04:00
Tom Rix 46bbe5c671 tracing: fix double free
clang static analyzer reports this problem

trace_events_hist.c:3824:3: warning: Attempt to free
  released memory
    kfree(hist_data->attrs->var_defs.name[i]);

In parse_var_defs() if there is a problem allocating
var_defs.expr, the earlier var_defs.name is freed.
This free is duplicated by free_var_defs() which frees
the rest of the list.

Because free_var_defs() has to run anyway, remove the
second free fom parse_var_defs().

Link: https://lkml.kernel.org/r/20200907135845.15804-1-trix@redhat.com

Cc: stable@vger.kernel.org
Fixes: 30350d65ac ("tracing: Add variable support to hist triggers")
Reviewed-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Tom Rix <trix@redhat.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-09-18 13:16:40 -04:00
Tobias Klauser 54fa9ba564 ftrace: Let ftrace_enable_sysctl take a kernel pointer buffer
Commit 32927393dc ("sysctl: pass kernel pointers to ->proc_handler")
changed ctl_table.proc_handler to take a kernel pointer. Adjust the
signature of ftrace_enable_sysctl to match ctl_table.proc_handler which
fixes the following sparse warning:

kernel/trace/ftrace.c:7544:43: warning: incorrect type in argument 3 (different address spaces)
kernel/trace/ftrace.c:7544:43:    expected void *
kernel/trace/ftrace.c:7544:43:    got void [noderef] __user *buffer

Link: https://lkml.kernel.org/r/20200907093207.13540-1-tklauser@distanz.ch

Fixes: 32927393dc ("sysctl: pass kernel pointers to ->proc_handler")
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-09-18 13:15:56 -04:00
Sebastian Andrzej Siewior 795d6379a4 tracing: Make the space reserved for the pid wider
For 64bit CONFIG_BASE_SMALL=0 systems PID_MAX_LIMIT is set by default to
4194304. During boot the kernel sets a new value based on number of CPUs
but no lower than 32768. It is 1024 per CPU so with 128 CPUs the default
becomes 131072 which needs six digits.
This value can be increased during run time but must not exceed the
initial upper limit.

Systemd sometime after v241 sets it to the upper limit during boot. The
result is that when the pid exceeds five digits, the trace output is a
little hard to read because it is no longer properly padded (same like
on big iron with 98+ CPUs).

Increase the pid padding to seven digits.

Link: https://lkml.kernel.org/r/20200904082331.dcdkrr3bkn3e4qlg@linutronix.de

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-09-18 12:42:11 -04:00
Adrian Hunter 478ece9573 ftrace: Fix missing synchronize_rcu() removing trampoline from kallsyms
Add synchronize_rcu() after list_del_rcu() in
ftrace_remove_trampoline_from_kallsyms() to protect readers of
ftrace_ops_trampoline_list (in ftrace_get_trampoline_kallsym)
which is used when kallsyms is read.

Link: https://lkml.kernel.org/r/20200901091617.31837-1-adrian.hunter@intel.com

Fixes: fc0ea795f5 ("ftrace: Add symbols for ftrace trampolines")
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-09-18 12:22:42 -04:00
Miroslav Benes d5e47505e0 ftrace: Free the trampoline when ftrace_startup() fails
Commit fc0ea795f5 ("ftrace: Add symbols for ftrace trampolines")
missed to remove ops from new ftrace_ops_trampoline_list in
ftrace_startup() if ftrace_hash_ipmodify_enable() fails there. It may
lead to BUG if such ops come from a module which may be removed.

Moreover, the trampoline itself is not freed in this case.

Fix it by calling ftrace_trampoline_free() during the rollback.

Link: https://lkml.kernel.org/r/20200831122631.28057-1-mbenes@suse.cz

Fixes: fc0ea795f5 ("ftrace: Add symbols for ftrace trampolines")
Fixes: f8b8be8a31 ("ftrace, kprobes: Support IPMODIFY flag to find IP modify conflict")
Signed-off-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-09-18 12:19:08 -04:00
Sven Schnelle 73ac74c7d4 lockdep: fix order in trace_hardirqs_off_caller()
Switch order so that locking state is consistent even
if the IRQ tracer calls into lockdep again.

Acked-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-09-14 10:08:07 +02:00
Wang Hai e75ad2cc41 blktrace: make function blk_trace_bio_get_cgid() static
The sparse tool complains as follows:

kernel/trace/blktrace.c:796:5: warning:
 symbol 'blk_trace_bio_get_cgid' was not declared. Should it be static?

This function is not used outside of blktrace.c, so this commit
marks it static.

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wang Hai <wanghai38@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-09-07 20:11:15 -06:00
Jakub Kicinski 44a8c4f33c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
We got slightly different patches removing a double word
in a comment in net/ipv4/raw.c - picked the version from net.

Simple conflict in drivers/net/ethernet/ibm/ibmvnic.c. Use cached
values instead of VNIC login response buffer (following what
commit 507ebe6444 ("ibmvnic: Fix use-after-free of VNIC login
response buffer") did).

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-09-04 21:28:59 -07:00
Peter Zijlstra 0340a6b7fb module: Fix up module_notifier return values
While auditing all module notifiers I noticed a whole bunch of fail
wrt the return value. Notifiers have a 'special' return semantics.

As is; NOTIFY_DONE vs NOTIFY_OK is a bit vague; but
notifier_from_errno(0) results in NOTIFY_OK and NOTIFY_DONE has a
comment that says "Don't care".

From this I've used NOTIFY_DONE when the function completely ignores
the callback and notifier_to_error() isn't used.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Reviewed-by: Robert Richter <rric@kernel.org>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Link: https://lore.kernel.org/r/20200818135804.385360407@infradead.org
2020-09-01 09:58:03 +02:00
Alexei Starovoitov 07be4c4a3e bpf: Add bpf_copy_from_user() helper.
Sleepable BPF programs can now use copy_from_user() to access user memory.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: KP Singh <kpsingh@google.com>
Link: https://lore.kernel.org/bpf/20200827220114.69225-4-alexei.starovoitov@gmail.com
2020-08-28 21:20:33 +02:00
Jiri Olsa 6e22ab9da7 bpf: Add d_path helper
Adding d_path helper function that returns full path for
given 'struct path' object, which needs to be the kernel
BTF 'path' object. The path is returned in buffer provided
'buf' of size 'sz' and is zero terminated.

  bpf_d_path(&file->f_path, buf, size);

The helper calls directly d_path function, so there's only
limited set of function it can be called from. Adding just
very modest set for the start.

Updating also bpf.h tools uapi header and adding 'path' to
bpf_helpers_doc.py script.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: KP Singh <kpsingh@google.com>
Link: https://lore.kernel.org/bpf/20200825192124.710397-11-jolsa@kernel.org
2020-08-25 15:41:15 -07:00
Gustavo A. R. Silva df561f6688 treewide: Use fallthrough pseudo-keyword
Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2020-08-23 17:36:59 -05:00
Linus Torvalds a1d21081a6 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Pull networking fixes from David Miller:
 "Some merge window fallout, some longer term fixes:

   1) Handle headroom properly in lapbether and x25_asy drivers, from
      Xie He.

   2) Fetch MAC address from correct r8152 device node, from Thierry
      Reding.

   3) In the sw kTLS path we should allow MSG_CMSG_COMPAT in sendmsg,
      from Rouven Czerwinski.

   4) Correct fdputs in socket layer, from Miaohe Lin.

   5) Revert troublesome sockptr_t optimization, from Christoph Hellwig.

   6) Fix TCP TFO key reading on big endian, from Jason Baron.

   7) Missing CAP_NET_RAW check in nfc, from Qingyu Li.

   8) Fix inet fastreuse optimization with tproxy sockets, from Tim
      Froidcoeur.

   9) Fix 64-bit divide in new SFC driver, from Edward Cree.

  10) Add a tracepoint for prandom_u32 so that we can more easily
      perform usage analysis. From Eric Dumazet.

  11) Fix rwlock imbalance in AF_PACKET, from John Ogness"

* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (49 commits)
  net: openvswitch: introduce common code for flushing flows
  af_packet: TPACKET_V3: fix fill status rwlock imbalance
  random32: add a tracepoint for prandom_u32()
  Revert "ipv4: tunnel: fix compilation on ARCH=um"
  net: accept an empty mask in /sys/class/net/*/queues/rx-*/rps_cpus
  net: ethernet: stmmac: Disable hardware multicast filter
  net: stmmac: dwmac1000: provide multicast filter fallback
  ipv4: tunnel: fix compilation on ARCH=um
  vsock: fix potential null pointer dereference in vsock_poll()
  sfc: fix ef100 design-param checking
  net: initialize fastreuse on inet_inherit_port
  net: refactor bind_bucket fastreuse into helper
  net: phy: marvell10g: fix null pointer dereference
  net: Fix potential memory leak in proto_register()
  net: qcom/emac: add missed clk_disable_unprepare in error path of emac_clks_phase1_init
  ionic_lif: Use devm_kcalloc() in ionic_qcq_alloc()
  net/nfc/rawsock.c: add CAP_NET_RAW check.
  hinic: fix strncpy output truncated compile warnings
  drivers/net/wan/x25_asy: Added needed_headroom and a skb->len check
  net/tls: Fix kmap usage
  ...
2020-08-13 20:03:11 -07:00
Linus Torvalds fc80c51fd4 Kbuild updates for v5.9
- run the checker (e.g. sparse) after the compiler
 
  - remove unneeded cc-option tests for old compiler flags
 
  - fix tar-pkg to install dtbs
 
  - introduce ccflags-remove-y and asflags-remove-y syntax
 
  - allow to trace functions in sub-directories of lib/
 
  - introduce hostprogs-always-y and userprogs-always-y syntax
 
  - various Makefile cleanups
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Merge tag 'kbuild-v5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:

 - run the checker (e.g. sparse) after the compiler

 - remove unneeded cc-option tests for old compiler flags

 - fix tar-pkg to install dtbs

 - introduce ccflags-remove-y and asflags-remove-y syntax

 - allow to trace functions in sub-directories of lib/

 - introduce hostprogs-always-y and userprogs-always-y syntax

 - various Makefile cleanups

* tag 'kbuild-v5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  kbuild: stop filtering out $(GCC_PLUGINS_CFLAGS) from cc-option base
  kbuild: include scripts/Makefile.* only when relevant CONFIG is enabled
  kbuild: introduce hostprogs-always-y and userprogs-always-y
  kbuild: sort hostprogs before passing it to ifneq
  kbuild: move host .so build rules to scripts/gcc-plugins/Makefile
  kbuild: Replace HTTP links with HTTPS ones
  kbuild: trace functions in subdirectories of lib/
  kbuild: introduce ccflags-remove-y and asflags-remove-y
  kbuild: do not export LDFLAGS_vmlinux
  kbuild: always create directories of targets
  powerpc/boot: add DTB to 'targets'
  kbuild: buildtar: add dtbs support
  kbuild: remove cc-option test of -ffreestanding
  kbuild: remove cc-option test of -fno-stack-protector
  Revert "kbuild: Create directory for target DTB"
  kbuild: run the checker after the compiler
2020-08-09 14:10:26 -07:00
Masahiro Yamada 15d5761ad3 kbuild: introduce ccflags-remove-y and asflags-remove-y
CFLAGS_REMOVE_<file>.o filters out flags when compiling a particular
object, but there is no convenient way to do that for every object in
a directory.

Add ccflags-remove-y and asflags-remove-y to make it easily.

Use ccflags-remove-y to clean up some Makefiles.

The add/remove order works as follows:

 [1] KBUILD_CFLAGS specifies compiler flags used globally

 [2] ccflags-y adds compiler flags for all objects in the
     current Makefile

 [3] ccflags-remove-y removes compiler flags for all objects in the
     current Makefile (New feature)

 [4] CFLAGS_<file> adds compiler flags per file.

 [5] CFLAGS_REMOVE_<file> removes compiler flags per file.

Having [3] before [4] allows us to remove flags from most (but not all)
objects in the current Makefile.

For example, kernel/trace/Makefile removes $(CC_FLAGS_FTRACE)
from all objects in the directory, then adds it back to
trace_selftest_dynamic.o and CFLAGS_trace_kprobe_selftest.o

The same applies to lib/livepatch/Makefile.

Please note ccflags-remove-y has no effect to the sub-directories.
In contrast, the previous notation got rid of compiler flags also from
all the sub-directories.

The following are not affected because they have no sub-directories:

  arch/arm/boot/compressed/
  arch/powerpc/xmon/
  arch/sh/
  kernel/trace/

However, lib/ has several sub-directories.

To keep the behavior, I added ccflags-remove-y to all Makefiles
in subdirectories of lib/, except the following:

  lib/vdso/Makefile        - Kbuild does not descend into this Makefile
  lib/raid/test/Makefile   - This is not used for the kernel build

I think commit 2464a609de ("ftrace: do not trace library functions")
excluded too much. In the next commit, I will remove ccflags-remove-y
from the sub-directories of lib/.

Suggested-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Acked-by: Brendan Higgins <brendanhiggins@google.com> (KUnit)
Tested-by: Anders Roxell <anders.roxell@linaro.org>
2020-08-10 01:32:59 +09:00
Linus Torvalds 32663c78c1 Tracing updates for 5.9
- The biggest news in that the tracing ring buffer can now time events that
    interrupted other ring buffer events. Before this change, if an interrupt
    came in while recording another event, and that interrupt also had an
    event, those events would all have the same time stamp as the event it
    interrupted. Now, with the new design, those events will have a unique time
    stamp and rightfully display the time for those events that were recorded
    while interrupting another event.
 
  - Bootconfig how has an "override" operator that lets the users have a
    default config, but then add options to override the default.
 
  - A fix was made to properly filter function graph tracing to the ftrace
    PIDs. This came in at the end of the -rc cycle, and needs to be backported.
 
  - Several clean ups, performance updates, and minor fixes as well.
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Merge tag 'trace-v5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:

 - The biggest news in that the tracing ring buffer can now time events
   that interrupted other ring buffer events.

   Before this change, if an interrupt came in while recording another
   event, and that interrupt also had an event, those events would all
   have the same time stamp as the event it interrupted.

   Now, with the new design, those events will have a unique time stamp
   and rightfully display the time for those events that were recorded
   while interrupting another event.

 - Bootconfig how has an "override" operator that lets the users have a
   default config, but then add options to override the default.

 - A fix was made to properly filter function graph tracing to the
   ftrace PIDs. This came in at the end of the -rc cycle, and needs to
   be backported.

 - Several clean ups, performance updates, and minor fixes as well.

* tag 'trace-v5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (39 commits)
  tracing: Add trace_array_init_printk() to initialize instance trace_printk() buffers
  kprobes: Fix compiler warning for !CONFIG_KPROBES_ON_FTRACE
  tracing: Use trace_sched_process_free() instead of exit() for pid tracing
  bootconfig: Fix to find the initargs correctly
  Documentation: bootconfig: Add bootconfig override operator
  tools/bootconfig: Add testcases for value override operator
  lib/bootconfig: Add override operator support
  kprobes: Remove show_registers() function prototype
  tracing/uprobe: Remove dead code in trace_uprobe_register()
  kprobes: Fix NULL pointer dereference at kprobe_ftrace_handler
  ftrace: Fix ftrace_trace_task return value
  tracepoint: Use __used attribute definitions from compiler_attributes.h
  tracepoint: Mark __tracepoint_string's __used
  trace : Have tracing buffer info use kvzalloc instead of kzalloc
  tracing: Remove outdated comment in stack handling
  ftrace: Do not let direct or IPMODIFY ftrace_ops be added to module and set trampolines
  ftrace: Setup correct FTRACE_FL_REGS flags for module
  tracing/hwlat: Honor the tracing_cpumask
  tracing/hwlat: Drop the duplicate assignment in start_kthread()
  tracing: Save one trace_event->type by using __TRACE_LAST_TYPE
  ...
2020-08-07 18:29:15 -07:00
Steven Rostedt (VMware) 38ce2a9e33 tracing: Add trace_array_init_printk() to initialize instance trace_printk() buffers
As trace_array_printk() used with not global instances will not add noise to
the main buffer, they are OK to have in the kernel (unlike trace_printk()).
This require the subsystem to create their own tracing instance, and the
trace_array_printk() only writes into those instances.

Add trace_array_init_printk() to initialize the trace_printk() buffers
without printing out the WARNING message.

Reported-by: Sean Paul <sean@poorly.run>
Reviewed-by: Sean Paul <sean@poorly.run>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-08-07 17:05:01 -04:00
Linus Torvalds eb65405eb6 \n
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Merge tag 'fsnotify_for_v5.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs

Pull fsnotify updates from Jan Kara:

 - fanotify fix for softlockups when there are many queued events

 - performance improvement to reduce fsnotify overhead when not used

 - Amir's implementation of fanotify events with names. With these you
   can now efficiently monitor whole filesystem, eg to mirror changes to
   another machine.

* tag 'fsnotify_for_v5.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs: (37 commits)
  fanotify: compare fsid when merging name event
  fsnotify: create method handle_inode_event() in fsnotify_operations
  fanotify: report parent fid + child fid
  fanotify: report parent fid + name + child fid
  fanotify: add support for FAN_REPORT_NAME
  fanotify: report events with parent dir fid to sb/mount/non-dir marks
  fanotify: add basic support for FAN_REPORT_DIR_FID
  fsnotify: remove check that source dentry is positive
  fsnotify: send event with parent/name info to sb/mount/non-dir marks
  audit: do not set FS_EVENT_ON_CHILD in audit marks mask
  inotify: do not set FS_EVENT_ON_CHILD in non-dir mark mask
  fsnotify: pass dir and inode arguments to fsnotify()
  fsnotify: create helper fsnotify_inode()
  fsnotify: send event to parent and child with single callback
  inotify: report both events on parent and child with single callback
  dnotify: report both events on parent and child with single callback
  fanotify: no external fh buffer in fanotify_name_event
  fanotify: use struct fanotify_info to parcel the variable size buffer
  fsnotify: add object type "child" to object type iterator
  fanotify: use FAN_EVENT_ON_CHILD as implicit flag on sb/mount/non-dir marks
  ...
2020-08-06 19:29:51 -07:00
Stanislav Fomichev 0d360d64b0 bpf: Remove inline from bpf_do_trace_printk
I get the following error during compilation on my side:
kernel/trace/bpf_trace.c: In function 'bpf_do_trace_printk':
kernel/trace/bpf_trace.c:386:34: error: function 'bpf_do_trace_printk' can never be inlined because it uses variable argument lists
 static inline __printf(1, 0) int bpf_do_trace_printk(const char *fmt, ...)
                                  ^

Fixes: ac5a72ea5c ("bpf: Use dedicated bpf_trace_printk event instead of trace_printk()")
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200806182612.1390883-1-sdf@google.com
2020-08-06 16:53:17 -07:00
Linus Torvalds 6d2b84a4e5 This tree adds the sched_set_fifo*() encapsulation APIs to remove
static priority level knowledge from non-scheduler code.
 
 The three APIs for non-scheduler code to set SCHED_FIFO are:
 
  - sched_set_fifo()
  - sched_set_fifo_low()
  - sched_set_normal()
 
 These are two FIFO priority levels: default (high), and a 'low' priority level,
 plus sched_set_normal() to set the policy back to non-SCHED_FIFO.
 
 Since the changes affect a lot of non-scheduler code, we kept this in a separate
 tree.
 
 When merging to the latest upstream tree there's a conflict in drivers/spi/spi.c,
 which can be resolved via:
 
 	sched_set_fifo(ctlr->kworker_task);
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'sched-fifo-2020-08-04' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull sched/fifo updates from Ingo Molnar:
 "This adds the sched_set_fifo*() encapsulation APIs to remove static
  priority level knowledge from non-scheduler code.

  The three APIs for non-scheduler code to set SCHED_FIFO are:

   - sched_set_fifo()
   - sched_set_fifo_low()
   - sched_set_normal()

  These are two FIFO priority levels: default (high), and a 'low'
  priority level, plus sched_set_normal() to set the policy back to
  non-SCHED_FIFO.

  Since the changes affect a lot of non-scheduler code, we kept this in
  a separate tree"

* tag 'sched-fifo-2020-08-04' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits)
  sched,tracing: Convert to sched_set_fifo()
  sched: Remove sched_set_*() return value
  sched: Remove sched_setscheduler*() EXPORTs
  sched,psi: Convert to sched_set_fifo_low()
  sched,rcutorture: Convert to sched_set_fifo_low()
  sched,rcuperf: Convert to sched_set_fifo_low()
  sched,locktorture: Convert to sched_set_fifo()
  sched,irq: Convert to sched_set_fifo()
  sched,watchdog: Convert to sched_set_fifo()
  sched,serial: Convert to sched_set_fifo()
  sched,powerclamp: Convert to sched_set_fifo()
  sched,ion: Convert to sched_set_normal()
  sched,powercap: Convert to sched_set_fifo*()
  sched,spi: Convert to sched_set_fifo*()
  sched,mmc: Convert to sched_set_fifo*()
  sched,ivtv: Convert to sched_set_fifo*()
  sched,drm/scheduler: Convert to sched_set_fifo*()
  sched,msm: Convert to sched_set_fifo*()
  sched,psci: Convert to sched_set_fifo*()
  sched,drbd: Convert to sched_set_fifo*()
  ...
2020-08-06 11:55:43 -07:00
Linus Torvalds 47ec5303d7 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next
Pull networking updates from David Miller:

 1) Support 6Ghz band in ath11k driver, from Rajkumar Manoharan.

 2) Support UDP segmentation in code TSO code, from Eric Dumazet.

 3) Allow flashing different flash images in cxgb4 driver, from Vishal
    Kulkarni.

 4) Add drop frames counter and flow status to tc flower offloading,
    from Po Liu.

 5) Support n-tuple filters in cxgb4, from Vishal Kulkarni.

 6) Various new indirect call avoidance, from Eric Dumazet and Brian
    Vazquez.

 7) Fix BPF verifier failures on 32-bit pointer arithmetic, from
    Yonghong Song.

 8) Support querying and setting hardware address of a port function via
    devlink, use this in mlx5, from Parav Pandit.

 9) Support hw ipsec offload on bonding slaves, from Jarod Wilson.

10) Switch qca8k driver over to phylink, from Jonathan McDowell.

11) In bpftool, show list of processes holding BPF FD references to
    maps, programs, links, and btf objects. From Andrii Nakryiko.

12) Several conversions over to generic power management, from Vaibhav
    Gupta.

13) Add support for SO_KEEPALIVE et al. to bpf_setsockopt(), from Dmitry
    Yakunin.

14) Various https url conversions, from Alexander A. Klimov.

15) Timestamping and PHC support for mscc PHY driver, from Antoine
    Tenart.

16) Support bpf iterating over tcp and udp sockets, from Yonghong Song.

17) Support 5GBASE-T i40e NICs, from Aleksandr Loktionov.

18) Add kTLS RX HW offload support to mlx5e, from Tariq Toukan.

19) Fix the ->ndo_start_xmit() return type to be netdev_tx_t in several
    drivers. From Luc Van Oostenryck.

20) XDP support for xen-netfront, from Denis Kirjanov.

21) Support receive buffer autotuning in MPTCP, from Florian Westphal.

22) Support EF100 chip in sfc driver, from Edward Cree.

23) Add XDP support to mvpp2 driver, from Matteo Croce.

24) Support MPTCP in sock_diag, from Paolo Abeni.

25) Commonize UDP tunnel offloading code by creating udp_tunnel_nic
    infrastructure, from Jakub Kicinski.

26) Several pci_ --> dma_ API conversions, from Christophe JAILLET.

27) Add FLOW_ACTION_POLICE support to mlxsw, from Ido Schimmel.

28) Add SK_LOOKUP bpf program type, from Jakub Sitnicki.

29) Refactor a lot of networking socket option handling code in order to
    avoid set_fs() calls, from Christoph Hellwig.

30) Add rfc4884 support to icmp code, from Willem de Bruijn.

31) Support TBF offload in dpaa2-eth driver, from Ioana Ciornei.

32) Support XDP_REDIRECT in qede driver, from Alexander Lobakin.

33) Support PCI relaxed ordering in mlx5 driver, from Aya Levin.

34) Support TCP syncookies in MPTCP, from Flowian Westphal.

35) Fix several tricky cases of PMTU handling wrt. briding, from Stefano
    Brivio.

* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2056 commits)
  net: thunderx: initialize VF's mailbox mutex before first usage
  usb: hso: remove bogus check for EINPROGRESS
  usb: hso: no complaint about kmalloc failure
  hso: fix bailout in error case of probe
  ip_tunnel_core: Fix build for archs without _HAVE_ARCH_IPV6_CSUM
  selftests/net: relax cpu affinity requirement in msg_zerocopy test
  mptcp: be careful on subflow creation
  selftests: rtnetlink: make kci_test_encap() return sub-test result
  selftests: rtnetlink: correct the final return value for the test
  net: dsa: sja1105: use detected device id instead of DT one on mismatch
  tipc: set ub->ifindex for local ipv6 address
  ipv6: add ipv6_dev_find()
  net: openvswitch: silence suspicious RCU usage warning
  Revert "vxlan: fix tos value before xmit"
  ptp: only allow phase values lower than 1 period
  farsync: switch from 'pci_' to 'dma_' API
  wan: wanxl: switch from 'pci_' to 'dma_' API
  hv_netvsc: do not use VF device if link is down
  dpaa2-eth: Fix passing zero to 'PTR_ERR' warning
  net: macb: Properly handle phylink on at91sam9x
  ...
2020-08-05 20:13:21 -07:00
Linus Torvalds dd27111e32 Driver core changes for 5.9-rc1
Here is the "big" set of changes to the driver core, and some drivers
 using the changes, for 5.9-rc1.
 
 "Biggest" thing in here is the device link exposure in sysfs, to help
 to tame the madness that is SoC device tree representations and driver
 interactions with it.
 
 Other stuff in here that is interesting is:
 	- device probe log helper so that drivers can report problems in
 	  a unified way easier.
 	- devres functions added
 	- DEVICE_ATTR_ADMIN_* macro added to make it harder to write
 	  incorrect sysfs file permissions
 	- documentation cleanups
 	- ability for debugfs to be present in the kernel, yet not
 	  exposed to userspace.  Needed for systems that want it
 	  enabled, but do not trust users, so they can still use some
 	  kernel functions that were otherwise disabled.
 	- other minor fixes and cleanups
 
 The patches outside of drivers/base/ all have acks from the respective
 subsystem maintainers to go through this tree instead of theirs.
 
 All of these have been in linux-next with no reported issues.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-5.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core updates from Greg KH:
 "Here is the "big" set of changes to the driver core, and some drivers
  using the changes, for 5.9-rc1.

  "Biggest" thing in here is the device link exposure in sysfs, to help
  to tame the madness that is SoC device tree representations and driver
  interactions with it.

  Other stuff in here that is interesting is:

   - device probe log helper so that drivers can report problems in a
     unified way easier.

   - devres functions added

   - DEVICE_ATTR_ADMIN_* macro added to make it harder to write
     incorrect sysfs file permissions

   - documentation cleanups

   - ability for debugfs to be present in the kernel, yet not exposed to
     userspace. Needed for systems that want it enabled, but do not
     trust users, so they can still use some kernel functions that were
     otherwise disabled.

   - other minor fixes and cleanups

  The patches outside of drivers/base/ all have acks from the respective
  subsystem maintainers to go through this tree instead of theirs.

  All of these have been in linux-next with no reported issues"

* tag 'driver-core-5.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (39 commits)
  drm/bridge: lvds-codec: simplify error handling
  drm/bridge/sii8620: fix resource acquisition error handling
  driver core: add deferring probe reason to devices_deferred property
  driver core: add device probe log helper
  driver core: Avoid binding drivers to dead devices
  Revert "test_firmware: Test platform fw loading on non-EFI systems"
  firmware_loader: EFI firmware loader must handle pre-allocated buffer
  selftest/firmware: Add selftest timeout in settings
  test_firmware: Test platform fw loading on non-EFI systems
  driver core: Change delimiter in devlink device's name to "--"
  debugfs: Add access restriction option
  tracefs: Remove unnecessary debug_fs checks.
  driver core: Fix probe_count imbalance in really_probe()
  kobject: remove unused KOBJ_MAX action
  driver core: Fix sleeping in invalid context during device link deletion
  driver core: Add waiting_for_supplier sysfs file for devices
  driver core: Add state_synced sysfs file for devices that support it
  driver core: Expose device link details in sysfs
  driver core: Drop mention of obsolete bus rwsem from kernel-doc
  debugfs: file: Remove unnecessary cast in kfree()
  ...
2020-08-05 11:52:17 -07:00
Steven Rostedt (VMware) afcab63665 tracing: Use trace_sched_process_free() instead of exit() for pid tracing
On exit, if a process is preempted after the trace_sched_process_exit()
tracepoint but before the process is done exiting, then when it gets
scheduled in, the function tracers will not filter it properly against the
function tracing pid filters.

That is because the function tracing pid filters hooks to the
sched_process_exit() tracepoint to remove the exiting task's pid from the
filter list. Because the filtering happens at the sched_switch tracepoint,
when the exiting task schedules back in to finish up the exit, it will no
longer be in the function pid filtering tables.

This was noticeable in the notrace self tests on a preemptable kernel, as
the tests would fail as it exits and preempted after being taken off the
notrace filter table and on scheduling back in it would not be in the
notrace list, and then the ending of the exit function would trace. The test
detected this and would fail.

Cc: stable@vger.kernel.org
Cc: Namhyung Kim <namhyung@kernel.org>
Fixes: 1e10486ffe ("ftrace: Add 'function-fork' trace option")
Fixes: c37775d578 ("tracing: Add infrastructure to allow set_event_pid to follow children"
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-08-04 20:15:07 -04:00
Linus Torvalds 99ea1521a0 Remove uninitialized_var() macro for v5.9-rc1
- Clean up non-trivial uses of uninitialized_var()
 - Update documentation and checkpatch for uninitialized_var() removal
 - Treewide removal of uninitialized_var()
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Merge tag 'uninit-macro-v5.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull uninitialized_var() macro removal from Kees Cook:
 "This is long overdue, and has hidden too many bugs over the years. The
  series has several "by hand" fixes, and then a trivial treewide
  replacement.

   - Clean up non-trivial uses of uninitialized_var()

   - Update documentation and checkpatch for uninitialized_var() removal

   - Treewide removal of uninitialized_var()"

* tag 'uninit-macro-v5.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  compiler: Remove uninitialized_var() macro
  treewide: Remove uninitialized_var() usage
  checkpatch: Remove awareness of uninitialized_var() macro
  mm/debug_vm_pgtable: Remove uninitialized_var() usage
  f2fs: Eliminate usage of uninitialized_var() macro
  media: sur40: Remove uninitialized_var() usage
  KVM: PPC: Book3S PR: Remove uninitialized_var() usage
  clk: spear: Remove uninitialized_var() usage
  clk: st: Remove uninitialized_var() usage
  spi: davinci: Remove uninitialized_var() usage
  ide: Remove uninitialized_var() usage
  rtlwifi: rtl8192cu: Remove uninitialized_var() usage
  b43: Remove uninitialized_var() usage
  drbd: Remove uninitialized_var() usage
  x86/mm/numa: Remove uninitialized_var() usage
  docs: deprecated.rst: Add uninitialized_var()
2020-08-04 13:49:43 -07:00
Linus Torvalds b34133fec8 - HW support updates:
- Add uncore support for Intel Comet Lake
 
    - Add RAPL support for Hygon Fam18h
 
    - Add Intel "IIO stack to PMON mapping" support on Skylake-SP CPUs,
      which enumerates per device performance counters via sysfs and enables
      the perf stat --iiostat functionality
 
    - Add support for Intel "Architectural LBRs", which generalized the model
      specific LBR hardware tracing feature into a model-independent, architected
      performance monitoring feature. Usage is mostly seamless to tooling, as the
      pre-existing LBR features are kept, but there's a couple of advantages
      under the hood, such as faster context-switching, faster LBR reads,
      cleaner exposure of LBR features to guest kernels, etc.
 
      ( Since architectural LBRs are supported via XSAVE, there's related
        changes to the x86 FPU code as well. )
 
  - ftrace/perf updates: Add support to add a text poke event to record changes
                         to kernel text (i.e. self-modifying code) in order to
                         support tracers like Intel PT decoding through
                         jump labels, kprobes and ftrace trampolines.
 
  - Misc cleanups, smaller fixes.
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'perf-core-2020-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull perf event updates from Ingo Molnar:
 "HW support updates:

   - Add uncore support for Intel Comet Lake

   - Add RAPL support for Hygon Fam18h

   - Add Intel "IIO stack to PMON mapping" support on Skylake-SP CPUs,
     which enumerates per device performance counters via sysfs and
     enables the perf stat --iiostat functionality

   - Add support for Intel "Architectural LBRs", which generalized the
     model specific LBR hardware tracing feature into a
     model-independent, architected performance monitoring feature.

     Usage is mostly seamless to tooling, as the pre-existing LBR
     features are kept, but there's a couple of advantages under the
     hood, such as faster context-switching, faster LBR reads, cleaner
     exposure of LBR features to guest kernels, etc.

     ( Since architectural LBRs are supported via XSAVE, there's related
       changes to the x86 FPU code as well. )

  ftrace/perf updates:

   - Add support to add a text poke event to record changes to kernel
     text (i.e. self-modifying code) in order to support tracers like
     Intel PT decoding through jump labels, kprobes and ftrace
     trampolines.

  Misc cleanups, smaller fixes..."

* tag 'perf-core-2020-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (47 commits)
  perf/x86/rapl: Add Hygon Fam18h RAPL support
  kprobes: Remove unnecessary module_mutex locking from kprobe_optimizer()
  x86/perf: Fix a typo
  perf: <linux/perf_event.h>: drop a duplicated word
  perf/x86/intel/lbr: Support XSAVES for arch LBR read
  perf/x86/intel/lbr: Support XSAVES/XRSTORS for LBR context switch
  x86/fpu/xstate: Add helpers for LBR dynamic supervisor feature
  x86/fpu/xstate: Support dynamic supervisor feature for LBR
  x86/fpu: Use proper mask to replace full instruction mask
  perf/x86: Remove task_ctx_size
  perf/x86/intel/lbr: Create kmem_cache for the LBR context data
  perf/core: Use kmem_cache to allocate the PMU specific data
  perf/core: Factor out functions to allocate/free the task_ctx_data
  perf/x86/intel/lbr: Support Architectural LBR
  perf/x86/intel/lbr: Factor out intel_pmu_store_lbr
  perf/x86/intel/lbr: Factor out rdlbr_all() and wrlbr_all()
  perf/x86/intel/lbr: Mark the {rd,wr}lbr_{to,from} wrappers __always_inline
  perf/x86/intel/lbr: Unify the stored format of LBR information
  perf/x86/intel/lbr: Support LBR_CTL
  perf/x86: Expose CPUID enumeration bits for arch LBR
  ...
2020-08-03 14:51:09 -07:00
Peng Fan 231621d0c5 tracing/uprobe: Remove dead code in trace_uprobe_register()
In the function trace_uprobe_register(), the statement "return 0;"
out of switch case is dead code, remove it.

Link: https://lkml.kernel.org/r/1595561064-29186-1-git-send-email-fanpeng@loongson.cn

Signed-off-by: Peng Fan <fanpeng@loongson.cn>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-08-03 16:16:46 -04:00
Josef Bacik c58b6b0372 ftrace: Fix ftrace_trace_task return value
I was attempting to use pid filtering with function_graph, but it wasn't
allowing anything to make it through.  Turns out ftrace_trace_task
returns false if ftrace_ignore_pid is not-empty, which isn't correct
anymore.  We're now setting it to FTRACE_PID_IGNORE if we need to ignore
that pid, otherwise it's set to the pid (which is weird considering the
name) or to FTRACE_PID_TRACE.  Fix the check to check for !=
FTRACE_PID_IGNORE.  With this we can now use function_graph with pid
filtering.

Link: https://lkml.kernel.org/r/20200725005048.1790-1-josef@toxicpanda.com

Fixes: 717e3f5ebc ("ftrace: Make function trace pid filtering a bit more exact")
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-08-03 16:12:31 -04:00
Linus Torvalds 382625d0d4 for-5.9/block-20200802
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Merge tag 'for-5.9/block-20200802' of git://git.kernel.dk/linux-block

Pull core block updates from Jens Axboe:
 "Good amount of cleanups and tech debt removals in here, and as a
  result, the diffstat shows a nice net reduction in code.

   - Softirq completion cleanups (Christoph)

   - Stop using ->queuedata (Christoph)

   - Cleanup bd claiming (Christoph)

   - Use check_events, moving away from the legacy media change
     (Christoph)

   - Use inode i_blkbits consistently (Christoph)

   - Remove old unused writeback congestion bits (Christoph)

   - Cleanup/unify submission path (Christoph)

   - Use bio_uninit consistently, instead of bio_disassociate_blkg
     (Christoph)

   - sbitmap cleared bits handling (John)

   - Request merging blktrace event addition (Jan)

   - sysfs add/remove race fixes (Luis)

   - blk-mq tag fixes/optimizations (Ming)

   - Duplicate words in comments (Randy)

   - Flush deferral cleanup (Yufen)

   - IO context locking/retry fixes (John)

   - struct_size() usage (Gustavo)

   - blk-iocost fixes (Chengming)

   - blk-cgroup IO stats fixes (Boris)

   - Various little fixes"

* tag 'for-5.9/block-20200802' of git://git.kernel.dk/linux-block: (135 commits)
  block: blk-timeout: delete duplicated word
  block: blk-mq-sched: delete duplicated word
  block: blk-mq: delete duplicated word
  block: genhd: delete duplicated words
  block: elevator: delete duplicated word and fix typos
  block: bio: delete duplicated words
  block: bfq-iosched: fix duplicated word
  iocost_monitor: start from the oldest usage index
  iocost: Fix check condition of iocg abs_vdebt
  block: Remove callback typedefs for blk_mq_ops
  block: Use non _rcu version of list functions for tag_set_list
  blk-cgroup: show global disk stats in root cgroup io.stat
  blk-cgroup: make iostat functions visible to stat printing
  block: improve discard bio alignment in __blkdev_issue_discard()
  block: change REQ_OP_ZONE_RESET and REQ_OP_ZONE_RESET_ALL to be odd numbers
  block: defer flush request no matter whether we have elevator
  block: make blk_timeout_init() static
  block: remove retry loop in ioc_release_fn()
  block: remove unnecessary ioc nested locking
  block: integrate bd_start_claiming into __blkdev_get
  ...
2020-08-03 11:57:03 -07:00
Zhaoyang Huang 0f69dae4d1 trace : Have tracing buffer info use kvzalloc instead of kzalloc
High order memory stuff within trace could introduce OOM, use kvzalloc instead.

Please find the bellowing for the call stack we run across in an android system.
The scenario happens when traced_probes is woken up to get a large quantity of
trace even if free memory is even higher than watermark_low. 

traced_probes invoked oom-killer: gfp_mask=0x140c0c0(GFP_KERNEL|__GFP_COMP|__GFP_ZERO), nodemask=(null),  order=2, oom_score_adj=-1

traced_probes cpuset=system-background mems_allowed=0
CPU: 3 PID: 588 Comm: traced_probes Tainted: G        W  O    4.14.181 #1
Hardware name: Generic DT based system
(unwind_backtrace) from [<c010d824>] (show_stack+0x20/0x24)
(show_stack) from [<c0b2e174>] (dump_stack+0xa8/0xec)
(dump_stack) from [<c027d584>] (dump_header+0x9c/0x220)
(dump_header) from [<c027cfe4>] (oom_kill_process+0xc0/0x5c4)
(oom_kill_process) from [<c027cb94>] (out_of_memory+0x220/0x310)
(out_of_memory) from [<c02816bc>] (__alloc_pages_nodemask+0xff8/0x13a4)
(__alloc_pages_nodemask) from [<c02a6a1c>] (kmalloc_order+0x30/0x48)
(kmalloc_order) from [<c02a6a64>] (kmalloc_order_trace+0x30/0x118)
(kmalloc_order_trace) from [<c0223d7c>] (tracing_buffers_open+0x50/0xfc)
(tracing_buffers_open) from [<c02e6f58>] (do_dentry_open+0x278/0x34c)
(do_dentry_open) from [<c02e70d0>] (vfs_open+0x50/0x70)
(vfs_open) from [<c02f7c24>] (path_openat+0x5fc/0x169c)
(path_openat) from [<c02f75c4>] (do_filp_open+0x94/0xf8)
(do_filp_open) from [<c02e7650>] (do_sys_open+0x168/0x26c)
(do_sys_open) from [<c02e77bc>] (SyS_openat+0x34/0x38)
(SyS_openat) from [<c0108bc0>] (ret_fast_syscall+0x0/0x28)

Link: https://lkml.kernel.org/r/1596155265-32365-1-git-send-email-zhaoyang.huang@unisoc.com

Signed-off-by: Zhaoyang Huang <zhaoyang.huang@unisoc.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-08-03 11:52:20 -04:00
Vincent Whitchurch ee896ee805 tracing: Remove outdated comment in stack handling
This comment describes the behaviour before commit 2a820bf749
("tracing: Use percpu stack trace buffer more intelligently").  Since
that commit, interrupts and NMIs do use the per-cpu stacks so the
comment is no longer correct.  Remove it.

(Note that the FTRACE_STACK_SIZE mentioned in the comment has never
existed, it probably should have said FTRACE_STACK_ENTRIES.)

Link: https://lkml.kernel.org/r/20200727092840.18659-1-vincent.whitchurch@axis.com

Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-07-30 22:54:50 -04:00
Chengming Zhou c5f51572a7 ftrace: Do not let direct or IPMODIFY ftrace_ops be added to module and set trampolines
When inserting a module, we find all ftrace_ops referencing it on the
ftrace_ops_list. But FTRACE_OPS_FL_DIRECT and FTRACE_OPS_FL_IPMODIFY
flags are special, and should not be set automatically. So warn and
skip ftrace_ops that have these two flags set and adding new code.
Also check if only one ftrace_ops references the module, in which case
we can use a trampoline as an optimization.

Link: https://lkml.kernel.org/r/20200728180554.65203-2-zhouchengming@bytedance.com

Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-07-30 22:45:31 -04:00
Chengming Zhou 8a224ffb3f ftrace: Setup correct FTRACE_FL_REGS flags for module
When module loaded and enabled, we will use __ftrace_replace_code
for module if any ftrace_ops referenced it found. But we will get
wrong ftrace_addr for module rec in ftrace_get_addr_new, because
rec->flags has not been setup correctly. It can cause the callback
function of a ftrace_ops has FTRACE_OPS_FL_SAVE_REGS to be called
with pt_regs set to NULL.
So setup correct FTRACE_FL_REGS flags for rec when we call
referenced_filters to find ftrace_ops references it.

Link: https://lkml.kernel.org/r/20200728180554.65203-1-zhouchengming@bytedance.com

Cc: stable@vger.kernel.org
Fixes: 8c4f3c3fa9 ("ftrace: Check module functions being traced on reload")
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-07-30 19:35:19 -04:00
Kevin Hao 96b4833b68 tracing/hwlat: Honor the tracing_cpumask
In calculation of the cpu mask for the hwlat kernel thread, the wrong
cpu mask is used instead of the tracing_cpumask, this causes the
tracing/tracing_cpumask useless for hwlat tracer. Fixes it.

Link: https://lkml.kernel.org/r/20200730082318.42584-2-haokexin@gmail.com

Cc: Ingo Molnar <mingo@redhat.com>
Cc: stable@vger.kernel.org
Fixes: 0330f7aa8e ("tracing: Have hwlat trace migrate across tracing_cpumask CPUs")
Signed-off-by: Kevin Hao <haokexin@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-07-30 19:35:04 -04:00
Kevin Hao a9d0ba6772 tracing/hwlat: Drop the duplicate assignment in start_kthread()
We have set 'current_mask' to '&save_cpumask' in its declaration,
so there is no need to assign again.

Link: https://lkml.kernel.org/r/20200730082318.42584-1-haokexin@gmail.com

Signed-off-by: Kevin Hao <haokexin@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-07-30 19:35:04 -04:00
Peter Zijlstra 4fd5750af0 sched,tracing: Convert to sched_set_fifo()
One module user of sched_setscheduler() was overlooked and is
obviously causing build failures.

Convert ring_buffer_benchmark to use sched_set_fifo_low() when fifo==1
and sched_set_fifo() when fifo==2. This is a bit of an abuse, but it
makes the thing 'work' again.

Specifically, it enables all combinations that were previously
possible:

  producer higher than consumer
  consumer higher than producer

Fixes: 616d91b68c ("sched: Remove sched_setscheduler*() EXPORTs")
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Link: https://lkml.kernel.org/r/20200720214918.GM5523@worktop.programming.kicks-ass.net
2020-07-29 11:43:53 +02:00
Amir Goldstein 82ace1efb3 fsnotify: create helper fsnotify_inode()
Simple helper to consolidate biolerplate code.

Link: https://lore.kernel.org/r/20200722125849.17418-5-amir73il@gmail.com
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2020-07-27 23:13:51 +02:00
Song Liu 7b04d6d60f bpf: Separate bpf_get_[stack|stackid] for perf events BPF
Calling get_perf_callchain() on perf_events from PEBS entries may cause
unwinder errors. To fix this issue, the callchain is fetched early. Such
perf_events are marked with __PERF_SAMPLE_CALLCHAIN_EARLY.

Similarly, calling bpf_get_[stack|stackid] on perf_events from PEBS may
also cause unwinder errors. To fix this, add separate version of these
two helpers, bpf_get_[stack|stackid]_pe. These two hepers use callchain in
bpf_perf_event_data_kern->data->callchain.

Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200723180648.1429892-2-songliubraving@fb.com
2020-07-25 20:16:34 -07:00
Peter Enderborg 072e133d55 tracefs: Remove unnecessary debug_fs checks.
This is a preparation for debugfs restricted mode.
We don't need debugfs to trace, the removed check stop tracefs to work
if debugfs is not initialised. We instead tries to automount within
debugfs and relay on it's handling. The code path is to create a
backward compatibility from when tracefs was part of debugfs, it is now
standalone and does not need debugfs. When debugfs is in restricted
it is compiled in but not active and return EPERM to clients and
tracefs wont work if it assumes it is active it is compiled in
kernel.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Peter Enderborg <peter.enderborg@sony.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Link: https://lore.kernel.org/r/20200716071511.26864-2-peter.enderborg@sony.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-23 17:10:25 +02:00
Kees Cook 3f649ab728 treewide: Remove uninitialized_var() usage
Using uninitialized_var() is dangerous as it papers over real bugs[1]
(or can in the future), and suppresses unrelated compiler warnings
(e.g. "unused variable"). If the compiler thinks it is uninitialized,
either simply initialize the variable or make compiler changes.

In preparation for removing[2] the[3] macro[4], remove all remaining
needless uses with the following script:

git grep '\buninitialized_var\b' | cut -d: -f1 | sort -u | \
	xargs perl -pi -e \
		's/\buninitialized_var\(([^\)]+)\)/\1/g;
		 s:\s*/\* (GCC be quiet|to make compiler happy) \*/$::g;'

drivers/video/fbdev/riva/riva_hw.c was manually tweaked to avoid
pathological white-space.

No outstanding warnings were found building allmodconfig with GCC 9.3.0
for x86_64, i386, arm64, arm, powerpc, powerpc64le, s390x, mips, sparc64,
alpha, and m68k.

[1] https://lore.kernel.org/lkml/20200603174714.192027-1-glider@google.com/
[2] https://lore.kernel.org/lkml/CA+55aFw+Vbj0i=1TGqCR5vQkCzWJ0QxK6CernOU6eedsudAixw@mail.gmail.com/
[3] https://lore.kernel.org/lkml/CA+55aFwgbgqhbp1fkxvRKEpzyR5J8n1vKT1VZdz9knmPuXhOeg@mail.gmail.com/
[4] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/

Reviewed-by: Leon Romanovsky <leonro@mellanox.com> # drivers/infiniband and mlx4/mlx5
Acked-by: Jason Gunthorpe <jgg@mellanox.com> # IB
Acked-by: Kalle Valo <kvalo@codeaurora.org> # wireless drivers
Reviewed-by: Chao Yu <yuchao0@huawei.com> # erofs
Signed-off-by: Kees Cook <keescook@chromium.org>
2020-07-16 12:35:15 -07:00
Alan Maguire ac5a72ea5c bpf: Use dedicated bpf_trace_printk event instead of trace_printk()
The bpf helper bpf_trace_printk() uses trace_printk() under the hood.
This leads to an alarming warning message originating from trace
buffer allocation which occurs the first time a program using
bpf_trace_printk() is loaded.

We can instead create a trace event for bpf_trace_printk() and enable
it in-kernel when/if we encounter a program using the
bpf_trace_printk() helper.  With this approach, trace_printk()
is not used directly and no warning message appears.

This work was started by Steven (see Link) and finished by Alan; added
Steven's Signed-off-by with his permission.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/r/20200628194334.6238b933@oasis.local.home
Link: https://lore.kernel.org/bpf/1594641154-18897-2-git-send-email-alan.maguire@oracle.com
2020-07-13 16:55:49 -07:00
Jiri Olsa c9a0f3b85e bpf: Resolve BTF IDs in vmlinux image
Using BTF_ID_LIST macro to define lists for several helpers
using BTF arguments.

And running resolve_btfids on vmlinux elf object during linking,
so the .BTF_ids section gets the IDs resolved.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200711215329.41165-5-jolsa@kernel.org
2020-07-13 10:42:02 -07:00
Wei Yang 36b8aacf2a tracing: Save one trace_event->type by using __TRACE_LAST_TYPE
Static defined trace_event->type stops at (__TRACE_LAST_TYPE - 1) and
dynamic trace_event->type starts from (__TRACE_LAST_TYPE + 1).

To save one trace_event->type index, let's use __TRACE_LAST_TYPE.

Link: https://lkml.kernel.org/r/20200703020612.12930-3-richard.weiyang@linux.alibaba.com

Signed-off-by: Wei Yang <richard.weiyang@linux.alibaba.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-07-09 18:14:58 -04:00
Wei Yang 746cf3459f tracing: Simplify defining of the next event id
The value to be used and compared in trace_search_list() is "last + 1".
Let's just define next to be "last + 1" instead of doing the addition
each time.

Link: https://lkml.kernel.org/r/20200703020612.12930-2-richard.weiyang@linux.alibaba.com

Signed-off-by: Wei Yang <richard.weiyang@linux.alibaba.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-07-09 18:00:47 -04:00
David S. Miller f91c031e65 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Daniel Borkmann says:

====================
pull-request: bpf-next 2020-07-04

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

We've added 73 non-merge commits during the last 17 day(s) which contain
a total of 106 files changed, 5233 insertions(+), 1283 deletions(-).

The main changes are:

1) bpftool ability to show PIDs of processes having open file descriptors
   for BPF map/program/link/BTF objects, relying on BPF iterator progs
   to extract this info efficiently, from Andrii Nakryiko.

2) Addition of BPF iterator progs for dumping TCP and UDP sockets to
   seq_files, from Yonghong Song.

3) Support access to BPF map fields in struct bpf_map from programs
   through BTF struct access, from Andrey Ignatov.

4) Add a bpf_get_task_stack() helper to be able to dump /proc/*/stack
   via seq_file from BPF iterator progs, from Song Liu.

5) Make SO_KEEPALIVE and related options available to bpf_setsockopt()
   helper, from Dmitry Yakunin.

6) Optimize BPF sk_storage selection of its caching index, from Martin
   KaFai Lau.

7) Removal of redundant synchronize_rcu()s from BPF map destruction which
   has been a historic leftover, from Alexei Starovoitov.

8) Several improvements to test_progs to make it easier to create a shell
   loop that invokes each test individually which is useful for some CIs,
   from Jesper Dangaard Brouer.

9) Fix bpftool prog dump segfault when compiled without skeleton code on
   older clang versions, from John Fastabend.

10) Bunch of cleanups and minor improvements, from various others.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-04 17:48:34 -07:00
Peter Zijlstra 78c2141b65 Merge branch 'perf/vlbr' 2020-07-02 15:51:48 +02:00
Steven Rostedt (VMware) 29ce24519c ring-buffer: Do not trigger a WARN if clock going backwards is detected
After tweaking the ring buffer to be a bit faster, a warning is triggering
on one of my machines, and causing my tests to fail. This warning is caused
when the delta (current time stamp minus previous time stamp), is larger
than the max time held by the ring buffer (59 bits).

If the clock were to go backwards slightly, this would then easily trigger
this warning. The machine that it triggered on, the clock did go backwards
by around 450 nanoseconds, and this happened after a recalibration of the
TSC clock. Now that the ring buffer is faster, it detects this, and the
delta that is used larger than the max, the warning is triggered and my test
fails.

To handle the clock going backwards, look at the saved before and after time
stamps. If they are the same, it means that the current event did not
interrupt another event, and that those timestamp are of a previous event
that was recorded. If the max delta is triggered, look at those time stamps,
make sure they are the same, then use them to compare with the current
timestamp. If the current timestamp is less than the before/after time
stamps, then that means the clock being used went backward.

Print out a message that this has happened, but do not warn about it (and
only print the message once).

Still do the warning if the delta is indeed larger than what can be used.

Also remove the unneeded KERN_WARNING from the WARN_ONCE() print.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-07-01 22:12:07 -04:00
Steven Rostedt (VMware) bbeba3e58f ring-buffer: Call trace_clock_local() directly for RETPOLINE kernels
After doing some benchmarks and examining the code, I found that the ring
buffer clock calls were quite expensive, and noticed that it uses
retpolines. This is because the ring buffer clock is programmable, and can
be set. But in most cases it simply uses the fastest ns unit clock which is
the trace_clock_local(). For RETPOLINE builds, checking if the ring buffer
clock is set to trace_clock_local() and then calling it directly has brought
the time of an event on my i7 box from an average of 93 nanoseconds an event
down to 83 nanoseconds an event, and the minimum time from 81 nanoseconds to
68 nanoseconds!

Suggested-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-07-01 22:12:07 -04:00
Steven Rostedt (VMware) 74e879373b ring-buffer: Move the add_timestamp into its own function
Make a helper function rb_add_timestamp() that moves the adding of the
extended time stamps into its own function. Also, remove the noinline and
inline for the functions it calls, as recent benchmarks appear they do not
make a difference (just let gcc decide).

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-07-01 22:12:06 -04:00
Steven Rostedt (VMware) 58fbc3c632 ring-buffer: Consolidate add_timestamp to remove some branches
Reorganize a little the logic to handle adding the absolute time stamp,
extended and forced time stamps, in such a way to remove a branch or two.
This is just a micro optimization.

Also add before and after time stamps to the rb_event_info structure to
display those values in the rb_check_timestamps() code, if something were to
go wrong.

Suggested-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-07-01 22:11:22 -04:00
Song Liu 2df6bb5493 bpf: Allow %pB in bpf_seq_printf() and bpf_trace_printk()
This makes it easy to dump stack trace in text.

Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200630062846.664389-4-songliubraving@fb.com
2020-07-01 08:23:59 -07:00
Song Liu fa28dcb82a bpf: Introduce helper bpf_get_task_stack()
Introduce helper bpf_get_task_stack(), which dumps stack trace of given
task. This is different to bpf_get_stack(), which gets stack track of
current task. One potential use case of bpf_get_task_stack() is to call
it from bpf_iter__task and dump all /proc/<pid>/stack to a seq_file.

bpf_get_task_stack() uses stack_trace_save_tsk() instead of
get_perf_callchain() for kernel stack. The benefit of this choice is that
stack_trace_save_tsk() doesn't require changes in arch/. The downside of
using stack_trace_save_tsk() is that stack_trace_save_tsk() dumps the
stack trace to unsigned long array. For 32-bit systems, we need to
translate it to u64 array.

Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200630062846.664389-3-songliubraving@fb.com
2020-07-01 08:23:19 -07:00
Steven Rostedt (VMware) 75b21c6dfa ring-buffer: Mark the !tail (crossing a page) as unlikely
It is the uncommon case where an event crosses a sub buffer boundary (page)
mark that check at the end of reserving an event as unlikely.

Suggested-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-06-30 17:18:56 -04:00
Nicholas Piggin b23d7a5f4a ring-buffer: speed up buffer resets by avoiding synchronize_rcu for each CPU
On a 144 thread system, `perf ftrace` takes about 20 seconds to start
up, due to calling synchronize_rcu() for each CPU.

  cat /proc/108560/stack
    0xc0003e7eb336f470
    __switch_to+0x2e0/0x480
    __wait_rcu_gp+0x20c/0x220
    synchronize_rcu+0x9c/0xc0
    ring_buffer_reset_cpu+0x88/0x2e0
    tracing_reset_online_cpus+0x84/0xe0
    tracing_open+0x1d4/0x1f0

On a system with 10x more threads, it starts to become an annoyance.

Batch these up so we disable all the per-cpu buffers first, then
synchronize_rcu() once, then reset each of the buffers. This brings
the time down to about 0.5s.

Link: https://lkml.kernel.org/r/20200625053403.2386972-1-npiggin@gmail.com

Tested-by: Anton Blanchard <anton@ozlabs.org>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-06-30 17:18:56 -04:00
Steven Rostedt (VMware) 10464b4aa6 ring-buffer: Add rb_time_t 64 bit operations for speeding up 32 bit
After a discussion with the new time algorithm to have nested events still
have proper time keeping but required using local64_t atomic operations.
Mathieu was concerned about the performance this would have on 32 bit
machines, as in most cases, atomic 64 bit operations on them can be
expensive.

As the ring buffer's timing needs do not require full features of local64_t,
a wrapper is made to implement a new rb_time_t operation that uses two longs
on 32 bit machines but still uses the local64_t operations on 64 bit
machines. There's a switch that can be made in the file to force 64 bit to
use the 32 bit version just for testing purposes.

All reads do not need to succeed if a read happened while the stamp being
read is in the process of being updated. The requirement is that all reads
must succed that were done by an interrupting event (where this event was
interrupted by another event that did the write). Or if the event itself did
the write first. That is: rb_time_set(t, x) followed by rb_time_read(t) will
always succeed (even if it gets interrupted by another event that writes to
t. The result of the read will be either the previous set, or a set
performed by an interrupting event.

If the read is done by an event that interrupted another event that was in
the process of setting the time stamp, and no other event came along to
write to that time stamp, it will fail and the rb_time_read() will return
that it failed (the value to read will be undefined).

A set will always write to the time stamp and return with a valid time
stamp, such that any read after it will be valid.

A cmpxchg may fail if it interrupted an event that was in the process of
updating the time stamp just like the reads do. Other than that, it will act
like a normal cmpxchg.

The way this works is that the rb_time_t is made of of three fields. A cnt,
that gets updated atomically everyting a modification is made. A top that
represents the most significant 30 bits of the time, and a bottom to
represent the least significant 30 bits of the time. Notice, that the time
values is only 60 bits long (where the ring buffer only uses 59 bits, which
gives us 18 years of nanoseconds!).

The top two bits of both the top and bottom is a 2 bit counter that gets set
by the value of the least two significant bits of the cnt. A read of the top
and the bottom where both the top and bottom have the same most significant
top 2 bits, are considered a match and a valid 60 bit number can be created
from it. If they do not match, then the number is considered invalid, and
this must only happen if an event interrupted another event in the midst of
updating the time stamp.

This is only used for 32 bits machines as 64 bit machines can get better
performance out of the local64_t. This has been tested heavily by forcing 64
bit to use this logic.

Link: https://lore.kernel.org/r/20200625225345.18cf5881@oasis.local.home
Link: http://lkml.kernel.org/r/20200629025259.309232719@goodmis.org

Inspired-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-06-30 17:18:51 -04:00
Steven Rostedt (VMware) 7c4b4a5164 ring-buffer: Incorporate absolute timestamp into add_timestamp logic
Instead of calling out the absolute test for each time to check if the
ring buffer wants absolute time stamps for all its recording, incorporate it
with the add_timestamp field and turn it into flags for faster processing
between wanting a absolute tag and needing to force one.

Link: http://lkml.kernel.org/r/20200629025259.154892368@goodmis.org

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-06-30 16:16:14 -04:00
Steven Rostedt (VMware) a389d86f7f ring-buffer: Have nested events still record running time stamp
Up until now, if an event is interrupted while it is recorded by an
interrupt, and that interrupt records events, the time of those events will
all be the same. This is because events only record the delta of the time
since the previous event (or beginning of a page), and to handle updating
the time keeping for that of nested events is extremely racy. After years of
thinking about this and several failed attempts, I finally have a solution
to solve this puzzle.

The problem is that you need to atomically calculate the delta and then
update the time stamp you made the delta from, as well as then record it
into the buffer, all this while at any time an interrupt can come in and
do the same thing. This is easy to solve with heavy weight atomics, but that
would be detrimental to the performance of the ring buffer. The current
state of affairs sacrificed the time deltas for nested events for
performance.

The reason for previous failed attempts at solving this puzzle was because I
was trying to completely avoid slow atomic operations like cmpxchg. I final
came to the conclusion to always avoid cmpxchg is not possible, which is why
those previous attempts always failed. But it is possible to pick one path
(the most common case) and avoid cmpxchg in that path, which is the "fast
path". The most common case is that an event will not be interrupted and
have other events added into it. An event can detect if it has
interrupted another event, and for these cases we can make it the slow
path and use the heavy operations like cmpxchg.

One more player was added to the game that made this possible, and that is
the "absolute timestamp" (by Tom Zanussi) that allows us to inject a full 59
bit time stamp. (Of course this breaks if a machine is running for more than
18 years without a reboot!).

There's barrier() placements around for being paranoid, even when they
are not needed because of other atomic functions near by. But those
should not hurt, as if they are not needed, they basically become a nop.

Note, this also makes the race window much smaller, which means there
are less slow paths to slow down the performance.

The basic idea is that there's two main paths taken.

 1) Not being interrupted between time stamps and reserving buffer space.
    In this case, the time stamps taken are true to the location in the
    buffer.

 2) Was interrupted by another path between taking time stamps and reserving
    buffer space.

The objective is to know what the delta is from the last reserved location
in the buffer.

As it is possible to detect if an event is interrupting another event before
reserving data, space is added to the length to be reserved to inject a full
time stamp along with the event being reserved.

When an event is not interrupted, the write stamp is always the time of the
last event written to the buffer.

In path 1, there's two sub paths we care about:

 a) The event did not interrupt another event.
 b) The event interrupted another event.

In case a, as the write stamp was read and known to be correct, the delta
between the current time stamp and the write stamp is the delta between the
current event and the previously recorded event.

In case b, extra space was reserved to just put the full time stamp into the
buffer. Which is done, as stated, in this path the time stamp taken is known
to match the location in the buffer.

In path 2, there's also two sub paths we care about:

 a) The event was not interrupted by another event since it reserved space
    on the buffer and re-reading the write stamp.
 b) The event was interrupted by another event.

In case a, the write stamp is that of the last event that interrupted this
event between taking the time stamps and reserving. As no event came in
after re-reading the write stamp, that event is known to be the time of the
event directly before this event and the delta can be the new time stamp and
the write stamp.

In case b, one or more events came in between reserving the event and
re-reading he write stamp. Since this event's buffer reservation is between
other events at this path, there's no way to know what the delta is. But
because an event interrupted this event after it started, its fine to just
give a zero delta, and take the same time stamp as the events that happened
within the event being recorded.

Here's the implementation of the design of this solution:

 All this is per cpu, and only needs to worry about nested events (not
 parallel events).

The players:

 write_tail: The index in the buffer where new events can be written to.
     It is incremented via local_add() to reserve space for a new event.

 before_stamp: A time stamp set by all events before reserving space.

 write_stamp: A time stamp updated by events after it has successfully
     reserved space.

	/* Save the current position of write */
 [A]	w = local_read(write_tail);
	barrier();
	/* Read both before and write stamps before touching anything */
	before = local_read(before_stamp);
	after = local_read(write_stamp);
	barrier();

	/*
	 * If before and after are the same, then this event is not
	 * interrupting a time update. If it is, then reserve space for adding
	 * a full time stamp (this can turn into a time extend which is
	 * just an extended time delta but fill up the extra space).
	 */
	if (after != before)
		abs = true;

	ts = clock();

	/* Now update the before_stamp (everyone does this!) */
 [B]	local_set(before_stamp, ts);

	/* Now reserve space on the buffer */
 [C]	write = local_add_return(len, write_tail);

	/* Set tail to be were this event's data is */
	tail = write - len;

 	if (w == tail) {

		/* Nothing interrupted this between A and C */
 [D]		local_set(write_stamp, ts);
		barrier();
 [E]		save_before = local_read(before_stamp);

 		if (!abs) {
			/* This did not interrupt a time update */
			delta = ts - after;
		} else {
			delta = ts; /* The full time stamp will be in use */
		}
		if (ts != save_before) {
			/* slow path - Was interrupted between C and E */
			/* The update to write_stamp could have overwritten the update to
			 * it by the interrupting event, but before and after should be
			 * the same for all completed top events */
			after = local_read(write_stamp);
			if (save_before > after)
				local_cmpxchg(write_stamp, after, save_before);
		}
	} else {
		/* slow path - Interrupted between A and C */

		after = local_read(write_stamp);
		temp_ts = clock();
		barrier();
 [F]		if (write == local_read(write_tail) && after < temp_ts) {
			/* This was not interrupted since C and F
			 * The last write_stamp is still valid for the previous event
			 * in the buffer. */
			delta = temp_ts - after;
			/* OK to keep this new time stamp */
			ts = temp_ts;
		} else {
			/* Interrupted between C and F
			 * Well, there's no use to try to know what the time stamp
			 * is for the previous event. Just set delta to zero and
			 * be the same time as that event that interrupted us before
			 * the reservation of the buffer. */

			delta = 0;
		}
		/* No need to use full timestamps here */
		abs = 0;
	}

Link: https://lkml.kernel.org/r/20200625094454.732790f7@oasis.local.home
Link: https://lore.kernel.org/r/20200627010041.517736087@goodmis.org
Link: http://lkml.kernel.org/r/20200629025258.957440797@goodmis.org

Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-06-30 14:29:33 -04:00
Steven Rostedt (VMware) 7ef282e051 tracing: Move pipe reference to trace array instead of current_tracer
If a process has the trace_pipe open on a trace_array, the current tracer
for that trace array should not be changed. This was original enforced by a
global lock, but when instances were introduced, it was moved to the
current_trace. But this structure is shared by all instances, and a
trace_pipe is for a single instance. There's no reason that a process that
has trace_pipe open on one instance should prevent another instance from
changing its current tracer. Move the reference counter to the trace_array
instead.

This is marked as "Fixes" but is more of a clean up than a true fix.
Backport if you want, but its not critical.

Fixes: cf6ab6d914 ("tracing: Add ref count to tracer for when they are being read by pipe")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-06-30 14:29:33 -04:00
Steven Rostedt (VMware) 5da7cd11d0 x86/ftrace: Only have the builtin ftrace_regs_caller call direct hooks
If a direct hook is attached to a function that ftrace also has a function
attached to it, then it is required that the ftrace_ops_list_func() is used
to iterate over the registered ftrace callbacks. This will also include the
direct ftrace_ops helper, that tells ftrace_regs_caller where to return to
(the direct callback and not the function that called it).

As this direct helper is only to handle the case of ftrace callbacks
attached to the same function as the direct callback, the ftrace callback
allocated trampolines (used to only call them), should never be used to
return back to a direct callback.

Only copy the portion of the ftrace_regs_caller that will return back to
what called it, and not the portion that returns back to the direct caller.

The direct ftrace_ops must then pick the ftrace_regs_caller builtin function
as its own trampoline to ensure that it will never have one allocated for
it (which would not include the handling of direct callbacks).

Link: http://lkml.kernel.org/r/20200422162750.495903799@goodmis.org

Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-06-29 11:42:47 -04:00
Steven Rostedt (VMware) c791cc4b1f tracing: Only allow trace_array_printk() to be used by instances
To prevent default "trace_printks()" from spamming the top level tracing
ring buffer, only allow trace instances to use trace_array_printk() (which
can be used without the trace_printk() start up warning).

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-06-29 09:01:02 -04:00
Jan Kara f3bdc62fd8 blktrace: Provide event for request merging
Currently blk-mq does not report any event when two requests get merged
in the elevator. This then results in difficult to understand sequence
of events like:

...
  8,0   34     1579     0.608765271  2718  I  WS 215023504 + 40 [dbench]
  8,0   34     1584     0.609184613  2719  A  WS 215023544 + 56 <- (8,4) 2160568
  8,0   34     1585     0.609184850  2719  Q  WS 215023544 + 56 [dbench]
  8,0   34     1586     0.609188524  2719  G  WS 215023544 + 56 [dbench]
  8,0    3      602     0.609684162   773  D  WS 215023504 + 96 [kworker/3:1H]
  8,0   34     1591     0.609843593     0  C  WS 215023504 + 96 [0]

and you can only guess (after quite some headscratching since the above
excerpt is intermixed with a lot of other IO) that request 215023544+56
got merged to request 215023504+40. Provide proper event for request
merging like we used to do in the legacy block layer.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-25 21:06:11 -06:00
Linus Torvalds 4a21185cda Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Pull networking fixes from David Miller:

 1) Don't insert ESP trailer twice in IPSEC code, from Huy Nguyen.

 2) The default crypto algorithm selection in Kconfig for IPSEC is out
    of touch with modern reality, fix this up. From Eric Biggers.

 3) bpftool is missing an entry for BPF_MAP_TYPE_RINGBUF, from Andrii
    Nakryiko.

 4) Missing init of ->frame_sz in xdp_convert_zc_to_xdp_frame(), from
    Hangbin Liu.

 5) Adjust packet alignment handling in ax88179_178a driver to match
    what the hardware actually does. From Jeremy Kerr.

 6) register_netdevice can leak in the case one of the notifiers fail,
    from Yang Yingliang.

 7) Use after free in ip_tunnel_lookup(), from Taehee Yoo.

 8) VLAN checks in sja1105 DSA driver need adjustments, from Vladimir
    Oltean.

 9) tg3 driver can sleep forever when we get enough EEH errors, fix from
    David Christensen.

10) Missing {READ,WRITE}_ONCE() annotations in various Intel ethernet
    drivers, from Ciara Loftus.

11) Fix scanning loop break condition in of_mdiobus_register(), from
    Florian Fainelli.

12) MTU limit is incorrect in ibmveth driver, from Thomas Falcon.

13) Endianness fix in mlxsw, from Ido Schimmel.

14) Use after free in smsc95xx usbnet driver, from Tuomas Tynkkynen.

15) Missing bridge mrp configuration validation, from Horatiu Vultur.

16) Fix circular netns references in wireguard, from Jason A. Donenfeld.

17) PTP initialization on recovery is not done properly in qed driver,
    from Alexander Lobakin.

18) Endian conversion of L4 ports in filters of cxgb4 driver is wrong,
    from Rahul Lakkireddy.

19) Don't clear bound device TX queue of socket prematurely otherwise we
    get problems with ktls hw offloading, from Tariq Toukan.

20) ipset can do atomics on unaligned memory, fix from Russell King.

21) Align ethernet addresses properly in bridging code, from Thomas
    Martitz.

22) Don't advertise ipv4 addresses on SCTP sockets having ipv6only set,
    from Marcelo Ricardo Leitner.

* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (149 commits)
  rds: transport module should be auto loaded when transport is set
  sch_cake: fix a few style nits
  sch_cake: don't call diffserv parsing code when it is not needed
  sch_cake: don't try to reallocate or unshare skb unconditionally
  ethtool: fix error handling in linkstate_prepare_data()
  wil6210: account for napi_gro_receive never returning GRO_DROP
  hns: do not cast return value of napi_gro_receive to null
  socionext: account for napi_gro_receive never returning GRO_DROP
  wireguard: receive: account for napi_gro_receive never returning GRO_DROP
  vxlan: fix last fdb index during dump of fdb with nhid
  sctp: Don't advertise IPv4 addresses if ipv6only is set on the socket
  tc-testing: avoid action cookies with odd length.
  bpf: tcp: bpf_cubic: fix spurious HYSTART_DELAY exit upon drop in min RTT
  tcp_cubic: fix spurious HYSTART_DELAY exit upon drop in min RTT
  net: dsa: sja1105: fix tc-gate schedule with single element
  net: dsa: sja1105: recalculate gating subschedule after deleting tc-gate rules
  net: dsa: sja1105: unconditionally free old gating config
  net: dsa: sja1105: move sja1105_compose_gating_subschedule at the top
  net: macb: free resources on failure path of at91ether_open()
  net: macb: call pm_runtime_put_sync on failure path
  ...
2020-06-25 18:27:40 -07:00
Yonghong Song 0d4fad3e57 bpf: Add bpf_skc_to_udp6_sock() helper
The helper is used in tracing programs to cast a socket
pointer to a udp6_sock pointer.
The return value could be NULL if the casting is illegal.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Cc: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/bpf/20200623230815.3988481-1-yhs@fb.com
2020-06-24 18:37:59 -07:00
Yonghong Song 478cfbdf5f bpf: Add bpf_skc_to_{tcp, tcp_timewait, tcp_request}_sock() helpers
Three more helpers are added to cast a sock_common pointer to
an tcp_sock, tcp_timewait_sock or a tcp_request_sock for
tracing programs.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20200623230811.3988277-1-yhs@fb.com
2020-06-24 18:37:59 -07:00
Yonghong Song af7ec13833 bpf: Add bpf_skc_to_tcp6_sock() helper
The helper is used in tracing programs to cast a socket
pointer to a tcp6_sock pointer.
The return value could be NULL if the casting is illegal.

A new helper return type RET_PTR_TO_BTF_ID_OR_NULL is added
so the verifier is able to deduce proper return types for the helper.

Different from the previous BTF_ID based helpers,
the bpf_skc_to_tcp6_sock() argument can be several possible
btf_ids. More specifically, all possible socket data structures
with sock_common appearing in the first in the memory layout.
This patch only added socket types related to tcp and udp.

All possible argument btf_id and return value btf_id
for helper bpf_skc_to_tcp6_sock() are pre-calculcated and
cached. In the future, it is even possible to precompute
these btf_id's at kernel build time.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20200623230809.3988195-1-yhs@fb.com
2020-06-24 18:37:59 -07:00
Yonghong Song 72e2b2b66f bpf: Allow tracing programs to use bpf_jiffies64() helper
/proc/net/tcp{4,6} uses jiffies for various computations.
Let us add bpf_jiffies64() helper to tracing program
so bpf_iter and other programs can use it.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20200623230808.3988073-1-yhs@fb.com
2020-06-24 18:37:58 -07:00
Yonghong Song c06b022957 bpf: Support 'X' in bpf_seq_printf() helper
'X' tells kernel to print hex with upper case letters.
/proc/net/tcp{4,6} seq_file show() used this, and
supports it in bpf_seq_printf() helper too.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20200623230807.3988014-1-yhs@fb.com
2020-06-24 18:37:58 -07:00
Luis Chamberlain 85e0cbbb8a block: create the request_queue debugfs_dir on registration
We were only creating the request_queue debugfs_dir only
for make_request block drivers (multiqueue), but never for
request-based block drivers. We did this as we were only
creating non-blktrace additional debugfs files on that directory
for make_request drivers. However, since blktrace *always* creates
that directory anyway, we special-case the use of that directory
on blktrace. Other than this being an eye-sore, this exposes
request-based block drivers to the same debugfs fragile
race that used to exist with make_request block drivers
where if we start adding files onto that directory we can later
run a race with a double removal of dentries on the directory
if we don't deal with this carefully on blktrace.

Instead, just simplify things by always creating the request_queue
debugfs_dir on request_queue registration. Rename the mutex also to
reflect the fact that this is used outside of the blktrace context.

Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-24 09:15:58 -06:00
Luis Chamberlain b431ef837e blktrace: ensure our debugfs dir exists
We make an assumption that a debugfs directory exists, but since
this can fail ensure it exists before allowing blktrace setup to
complete. Otherwise we end up stuffing blktrace files on the debugfs
root directory. In the worst case scenario this *in theory* can create
an eventual panic *iff* in the future a similarly named file is created
prior on the debugfs root directory. This theoretical crash can happen
due to a recursive removal followed by a specific dentry removal.

This doesn't fix any known crash, however I have seen the files
go into the main debugfs root directory in cases where the debugfs
directory was not created due to other internal bugs with blktrace
now fixed.

blktrace is also completely useless without this directory, so
this ensures to userspace we only setup blktrace if the kernel
can stuff files where they are supposed to go into.

debugfs directory creations typically aren't checked for, and we have
maintainers doing sweep removals of these checks, but since we need this
check to ensure proper userspace blktrace functionality we make sure
to annotate the justification for the check.

Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-24 09:15:58 -06:00
Luis Chamberlain bad8e64fb1 blktrace: fix debugfs use after free
On commit 6ac93117ab ("blktrace: use existing disk debugfs directory")
merged on v4.12 Omar fixed the original blktrace code for request-based
drivers (multiqueue). This however left in place a possible crash, if you
happen to abuse blktrace while racing to remove / add a device.

We used to use asynchronous removal of the request_queue, and with that
the issue was easier to reproduce. Now that we have reverted to
synchronous removal of the request_queue, the issue is still possible to
reproduce, its however just a bit more difficult.

We essentially run two instances of break-blktrace which add/remove
a loop device, and setup a blktrace and just never tear the blktrace
down. We do this twice in parallel. This is easily reproduced with the
script run_0004.sh from break-blktrace [0].

We can end up with two types of panics each reflecting where we
race, one a failed blktrace setup:

[  252.426751] debugfs: Directory 'loop0' with parent 'block' already present!
[  252.432265] BUG: kernel NULL pointer dereference, address: 00000000000000a0
[  252.436592] #PF: supervisor write access in kernel mode
[  252.439822] #PF: error_code(0x0002) - not-present page
[  252.442967] PGD 0 P4D 0
[  252.444656] Oops: 0002 [#1] SMP NOPTI
[  252.446972] CPU: 10 PID: 1153 Comm: break-blktrace Tainted: G            E     5.7.0-rc2-next-20200420+ #164
[  252.452673] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1 04/01/2014
[  252.456343] RIP: 0010:down_write+0x15/0x40
[  252.458146] Code: eb ca e8 ae 22 8d ff cc cc cc cc cc cc cc cc cc cc cc cc
               cc cc 0f 1f 44 00 00 55 48 89 fd e8 52 db ff ff 31 c0 ba 01 00
               00 00 <f0> 48 0f b1 55 00 75 0f 48 8b 04 25 c0 8b 01 00 48 89
               45 08 5d
[  252.463638] RSP: 0018:ffffa626415abcc8 EFLAGS: 00010246
[  252.464950] RAX: 0000000000000000 RBX: ffff958c25f0f5c0 RCX: ffffff8100000000
[  252.466727] RDX: 0000000000000001 RSI: ffffff8100000000 RDI: 00000000000000a0
[  252.468482] RBP: 00000000000000a0 R08: 0000000000000000 R09: 0000000000000001
[  252.470014] R10: 0000000000000000 R11: ffff958d1f9227ff R12: 0000000000000000
[  252.471473] R13: ffff958c25ea5380 R14: ffffffff8cce15f1 R15: 00000000000000a0
[  252.473346] FS:  00007f2e69dee540(0000) GS:ffff958c2fc80000(0000) knlGS:0000000000000000
[  252.475225] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  252.476267] CR2: 00000000000000a0 CR3: 0000000427d10004 CR4: 0000000000360ee0
[  252.477526] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  252.478776] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[  252.479866] Call Trace:
[  252.480322]  simple_recursive_removal+0x4e/0x2e0
[  252.481078]  ? debugfs_remove+0x60/0x60
[  252.481725]  ? relay_destroy_buf+0x77/0xb0
[  252.482662]  debugfs_remove+0x40/0x60
[  252.483518]  blk_remove_buf_file_callback+0x5/0x10
[  252.484328]  relay_close_buf+0x2e/0x60
[  252.484930]  relay_open+0x1ce/0x2c0
[  252.485520]  do_blk_trace_setup+0x14f/0x2b0
[  252.486187]  __blk_trace_setup+0x54/0xb0
[  252.486803]  blk_trace_ioctl+0x90/0x140
[  252.487423]  ? do_sys_openat2+0x1ab/0x2d0
[  252.488053]  blkdev_ioctl+0x4d/0x260
[  252.488636]  block_ioctl+0x39/0x40
[  252.489139]  ksys_ioctl+0x87/0xc0
[  252.489675]  __x64_sys_ioctl+0x16/0x20
[  252.490380]  do_syscall_64+0x52/0x180
[  252.491032]  entry_SYSCALL_64_after_hwframe+0x44/0xa9

And the other on the device removal:

[  128.528940] debugfs: Directory 'loop0' with parent 'block' already present!
[  128.615325] BUG: kernel NULL pointer dereference, address: 00000000000000a0
[  128.619537] #PF: supervisor write access in kernel mode
[  128.622700] #PF: error_code(0x0002) - not-present page
[  128.625842] PGD 0 P4D 0
[  128.627585] Oops: 0002 [#1] SMP NOPTI
[  128.629871] CPU: 12 PID: 544 Comm: break-blktrace Tainted: G            E     5.7.0-rc2-next-20200420+ #164
[  128.635595] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1 04/01/2014
[  128.640471] RIP: 0010:down_write+0x15/0x40
[  128.643041] Code: eb ca e8 ae 22 8d ff cc cc cc cc cc cc cc cc cc cc cc cc
               cc cc 0f 1f 44 00 00 55 48 89 fd e8 52 db ff ff 31 c0 ba 01 00
               00 00 <f0> 48 0f b1 55 00 75 0f 65 48 8b 04 25 c0 8b 01 00 48 89
               45 08 5d
[  128.650180] RSP: 0018:ffffa9c3c05ebd78 EFLAGS: 00010246
[  128.651820] RAX: 0000000000000000 RBX: ffff8ae9a6370240 RCX: ffffff8100000000
[  128.653942] RDX: 0000000000000001 RSI: ffffff8100000000 RDI: 00000000000000a0
[  128.655720] RBP: 00000000000000a0 R08: 0000000000000002 R09: ffff8ae9afd2d3d0
[  128.657400] R10: 0000000000000056 R11: 0000000000000000 R12: 0000000000000000
[  128.659099] R13: 0000000000000000 R14: 0000000000000003 R15: 00000000000000a0
[  128.660500] FS:  00007febfd995540(0000) GS:ffff8ae9afd00000(0000) knlGS:0000000000000000
[  128.662204] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  128.663426] CR2: 00000000000000a0 CR3: 0000000420042003 CR4: 0000000000360ee0
[  128.664776] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  128.666022] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[  128.667282] Call Trace:
[  128.667801]  simple_recursive_removal+0x4e/0x2e0
[  128.668663]  ? debugfs_remove+0x60/0x60
[  128.669368]  debugfs_remove+0x40/0x60
[  128.669985]  blk_trace_free+0xd/0x50
[  128.670593]  __blk_trace_remove+0x27/0x40
[  128.671274]  blk_trace_shutdown+0x30/0x40
[  128.671935]  blk_release_queue+0x95/0xf0
[  128.672589]  kobject_put+0xa5/0x1b0
[  128.673188]  disk_release+0xa2/0xc0
[  128.673786]  device_release+0x28/0x80
[  128.674376]  kobject_put+0xa5/0x1b0
[  128.674915]  loop_remove+0x39/0x50 [loop]
[  128.675511]  loop_control_ioctl+0x113/0x130 [loop]
[  128.676199]  ksys_ioctl+0x87/0xc0
[  128.676708]  __x64_sys_ioctl+0x16/0x20
[  128.677274]  do_syscall_64+0x52/0x180
[  128.677823]  entry_SYSCALL_64_after_hwframe+0x44/0xa9

The common theme here is:

debugfs: Directory 'loop0' with parent 'block' already present

This crash happens because of how blktrace uses the debugfs directory
where it places its files. Upon init we always create the same directory
which would be needed by blktrace but we only do this for make_request
drivers (multiqueue) block drivers. When you race a removal of these
devices with a blktrace setup you end up in a situation where the
make_request recursive debugfs removal will sweep away the blktrace
files and then later blktrace will also try to remove individual
dentries which are already NULL. The inverse is also possible and hence
the two types of use after frees.

We don't create the block debugfs directory on init for these types of
block devices:

  * request-based block driver block devices
  * every possible partition
  * scsi-generic

And so, this race should in theory only be possible with make_request
drivers.

We can fix the UAF by simply re-using the debugfs directory for
make_request drivers (multiqueue) and only creating the ephemeral
directory for the other type of block devices. The new clarifications
on relying on the q->blk_trace_mutex *and* also checking for q->blk_trace
*prior* to processing a blktrace ensures the debugfs directories are
only created if no possible directory name clashes are possible.

This goes tested with:

  o nvme partitions
  o ISCSI with tgt, and blktracing against scsi-generic with:
    o block
    o tape
    o cdrom
    o media changer
  o blktests

This patch is part of the work which disputes the severity of
CVE-2019-19770 which shows this issue is not a core debugfs issue, but
a misuse of debugfs within blktace.

Fixes: 6ac93117ab ("blktrace: use existing disk debugfs directory")
Reported-by: syzbot+603294af2d01acfdd6da@syzkaller.appspotmail.com
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Bart Van Assche <bvanassche@acm.org>
Cc: Omar Sandoval <osandov@fb.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Nicolai Stange <nstange@suse.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: "James E.J. Bottomley" <jejb@linux.ibm.com>
Cc: yu kuai <yukuai3@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-24 09:15:58 -06:00
Luis Chamberlain a67549c8e5 blktrace: annotate required lock on do_blk_trace_setup()
Ensure it is clear which lock is required on do_blk_trace_setup().

Suggested-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-24 09:15:58 -06:00
Sascha Ortmann 20dc3847cc tracing/boottime: Fix kprobe multiple events
Fix boottime kprobe events to report and abort after each failure when
adding probes.

As an example, when we try to set multiprobe kprobe events in
bootconfig like this:

ftrace.event.kprobes.vfsevents {
        probes = "vfs_read $arg1 $arg2,,
                 !error! not reported;?", // leads to error
                 "vfs_write $arg1 $arg2"
}

This will not work as expected. After
commit da0f1f4167 ("tracing/boottime: Fix kprobe event API usage"),
the function trace_boot_add_kprobe_event will not produce any error
message when adding a probe fails at kprobe_event_gen_cmd_start.
Furthermore, we continue to add probes when kprobe_event_gen_cmd_end fails
(and kprobe_event_gen_cmd_start did not fail). In this case the function
even returns successfully when the last call to kprobe_event_gen_cmd_end
is successful.

The behaviour of reporting and aborting after failures is not
consistent.

The function trace_boot_add_kprobe_event now reports each failure and
stops adding probes immediately.

Link: https://lkml.kernel.org/r/20200618163301.25854-1-sascha.ortmann@stud.uni-hannover.de

Cc: stable@vger.kernel.org
Cc: linux-kernel@i4.cs.fau.de
Co-developed-by: Maximilian Werner <maximilian.werner96@gmail.com>
Fixes: da0f1f4167 ("tracing/boottime: Fix kprobe event API usage")
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Maximilian Werner <maximilian.werner96@gmail.com>
Signed-off-by: Sascha Ortmann <sascha.ortmann@stud.uni-hannover.de>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-06-23 21:51:50 -04:00
Masami Hiramatsu 6784beada6 tracing: Fix event trigger to accept redundant spaces
Fix the event trigger to accept redundant spaces in
the trigger input.

For example, these return -EINVAL

echo " traceon" > events/ftrace/print/trigger
echo "traceon  if common_pid == 0" > events/ftrace/print/trigger
echo "disable_event:kmem:kmalloc " > events/ftrace/print/trigger

But these are hard to find what is wrong.

To fix this issue, use skip_spaces() to remove spaces
in front of actual tokens, and set NULL if there is no
token.

Link: http://lkml.kernel.org/r/159262476352.185015.5261566783045364186.stgit@devnote2

Cc: Tom Zanussi <zanussi@kernel.org>
Cc: stable@vger.kernel.org
Fixes: 85f2b08268 ("tracing: Add basic event trigger framework")
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-06-23 21:51:40 -04:00
Masami Hiramatsu 6c95503c29 tracing/boot: Fix config dependency for synthedic event
Since commit 726721a518 ("tracing: Move synthetic events to
a separate file") decoupled synthetic event from histogram,
boot-time tracing also has to check CONFIG_SYNTH_EVENT instead
of CONFIG_HIST_TRIGGERS.

Link: http://lkml.kernel.org/r/159262475441.185015.5300725180746017555.stgit@devnote2

Fixes: 726721a518 ("tracing: Move synthetic events to a separate file")
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-06-23 21:51:22 -04:00
Alexei Starovoitov 4e608675e7 Merge up to bpf_probe_read_kernel_str() fix into bpf-next 2020-06-23 15:33:41 -07:00
Steven Rostedt (VMware) 097350d1c6 ring-buffer: Zero out time extend if it is nested and not absolute
Currently the ring buffer makes events that happen in interrupts that preempt
another event have a delta of zero. (Hopefully we can change this soon). But
this is to deal with the races of updating a global counter with lockless
and nesting functions updating deltas.

With the addition of absolute time stamps, the time extend didn't follow
this rule. A time extend can happen if two events happen longer than 2^27
nanoseconds appart, as the delta time field in each event is only 27 bits.
If that happens, then a time extend is injected with 2^59 bits of
nanoseconds to use (18 years). But if the 2^27 nanoseconds happen between
two events, and as it is writing the event, an interrupt triggers, it will
see the 2^27 difference as well and inject a time extend of its own. But a
recent change made the time extend logic not take into account the nesting,
and this can cause two time extend deltas to happen moving the time stamp
much further ahead than the current time. This gets all reset when the ring
buffer moves to the next page, but that can cause time to appear to go
backwards.

This was observed in a trace-cmd recording, and since the data is saved in a
file, with trace-cmd report --debug, it was possible to see that this indeed
did happen!

  bash-52501   110d... 81778.908247: sched_switch:         bash:52501 [120] S ==> swapper/110:0 [120] [12770284:0x2e8:64]
  <idle>-0     110d... 81778.908757: sched_switch:         swapper/110:0 [120] R ==> bash:52501 [120] [509947:0x32c:64]
 TIME EXTEND: delta:306454770 length:0
  bash-52501   110.... 81779.215212: sched_swap_numa:      src_pid=52501 src_tgid=52388 src_ngid=52501 src_cpu=110 src_nid=2 dst_pid=52509 dst_tgid=52388 dst_ngid=52501 dst_cpu=49 dst_nid=1 [0:0x378:48]
 TIME EXTEND: delta:306458165 length:0
  bash-52501   110dNh. 81779.521670: sched_wakeup:         migration/110:565 [0] success=1 CPU:110 [0:0x3b4:40]

and at the next page, caused the time to go backwards:

  bash-52504   110d... 81779.685411: sched_switch:         bash:52504 [120] S ==> swapper/110:0 [120] [8347057:0xfb4:64]
CPU:110 [SUBBUFFER START] [81779379165886:0x1320000]
  <idle>-0     110dN.. 81779.379166: sched_wakeup:         bash:52504 [120] success=1 CPU:110 [0:0x10:40]
  <idle>-0     110d... 81779.379167: sched_switch:         swapper/110:0 [120] R ==> bash:52504 [120] [1168:0x3c:64]

Link: https://lkml.kernel.org/r/20200622151815.345d1bf5@oasis.local.home

Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Tom Zanussi <zanussi@kernel.org>
Cc: stable@vger.kernel.org
Fixes: dc4e2801d4 ("ring-buffer: Redefine the unimplemented RINGBUF_TYPE_TIME_STAMP")
Reported-by: Julia Lawall <julia.lawall@inria.fr>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-06-23 11:18:42 -04:00
Linus Torvalds 8b6ddd10d6 A few fixes and small cleanups for tracing:
- Have recordmcount work with > 64K sections (to support LTO)
  - kprobe RCU fixes
  - Correct a kprobe critical section with missing mutex
  - Remove redundant arch_disarm_kprobe() call
  - Fix lockup when kretprobe triggers within kprobe_flush_task()
  - Fix memory leak in fetch_op_data operations
  - Fix sleep in atomic in ftrace trace array sample code
  - Free up memory on failure in sample trace array code
  - Fix incorrect reporting of function_graph fields in format file
  - Fix quote within quote parsing in bootconfig
  - Fix return value of bootconfig tool
  - Add testcases for bootconfig tool
  - Fix maybe uninitialized warning in ftrace pid file code
  - Remove unused variable in tracing_iter_reset()
  - Fix some typos
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Merge tag 'trace-v5.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixes from Steven Rostedt:

 - Have recordmcount work with > 64K sections (to support LTO)

 - kprobe RCU fixes

 - Correct a kprobe critical section with missing mutex

 - Remove redundant arch_disarm_kprobe() call

 - Fix lockup when kretprobe triggers within kprobe_flush_task()

 - Fix memory leak in fetch_op_data operations

 - Fix sleep in atomic in ftrace trace array sample code

 - Free up memory on failure in sample trace array code

 - Fix incorrect reporting of function_graph fields in format file

 - Fix quote within quote parsing in bootconfig

 - Fix return value of bootconfig tool

 - Add testcases for bootconfig tool

 - Fix maybe uninitialized warning in ftrace pid file code

 - Remove unused variable in tracing_iter_reset()

 - Fix some typos

* tag 'trace-v5.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  ftrace: Fix maybe-uninitialized compiler warning
  tools/bootconfig: Add testcase for show-command and quotes test
  tools/bootconfig: Fix to return 0 if succeeded to show the bootconfig
  tools/bootconfig: Fix to use correct quotes for value
  proc/bootconfig: Fix to use correct quotes for value
  tracing: Remove unused event variable in tracing_iter_reset
  tracing/probe: Fix memleak in fetch_op_data operations
  trace: Fix typo in allocate_ftrace_ops()'s comment
  tracing: Make ftrace packed events have align of 1
  sample-trace-array: Remove trace_array 'sample-instance'
  sample-trace-array: Fix sleeping function called from invalid context
  kretprobe: Prevent triggering kretprobe from within kprobe_flush_task
  kprobes: Remove redundant arch_disarm_kprobe() call
  kprobes: Fix to protect kick_kprobe_optimizer() by kprobe_mutex
  kprobes: Use non RCU traversal APIs on kprobe_tables if possible
  kprobes: Suppress the suspicious RCU warning on kprobes
  recordmcount: support >64k sections
2020-06-20 13:17:47 -07:00
Linus Torvalds d2b1c81f5f block-5.8-2020-06-19
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Merge tag 'block-5.8-2020-06-19' of git://git.kernel.dk/linux-block

Pull block fixes from Jens Axboe:

 - Use import_uuid() where appropriate (Andy)

 - bcache fixes (Coly, Mauricio, Zhiqiang)

 - blktrace sparse warnings fix (Jan)

 - blktrace concurrent setup fix (Luis)

 - blkdev_get use-after-free fix (Jason)

 - Ensure all blk-mq maps are updated (Weiping)

 - Loop invalidate bdev fix (Zheng)

* tag 'block-5.8-2020-06-19' of git://git.kernel.dk/linux-block:
  block: make function 'kill_bdev' static
  loop: replace kill_bdev with invalidate_bdev
  partitions/ldm: Replace uuid_copy() with import_uuid() where it makes sense
  block: update hctx map when use multiple maps
  blktrace: Avoid sparse warnings when assigning q->blk_trace
  blktrace: break out of blktrace setup on concurrent calls
  block: Fix use-after-free in blkdev_get()
  trace/events/block.h: drop kernel-doc for dropped function parameter
  blk-mq: Remove redundant 'return' statement
  bcache: pr_info() format clean up in bcache_device_init()
  bcache: use delayed kworker fo asynchronous devices registration
  bcache: check and adjust logical block size for backing devices
  bcache: fix potential deadlock problem in btree_gc_coalesce
2020-06-19 13:11:26 -07:00
Linus Torvalds 5e857ce6ea Merge branch 'hch' (maccess patches from Christoph Hellwig)
Merge non-faulting memory access cleanups from Christoph Hellwig:
 "Andrew and I decided to drop the patches implementing your suggested
  rename of the probe_kernel_* and probe_user_* helpers from -mm as
  there were way to many conflicts.

  After -rc1 might be a good time for this as all the conflicts are
  resolved now"

This also adds a type safety checking patch on top of the renaming
series to make the subtle behavioral difference between 'get_user()' and
'get_kernel_nofault()' less potentially dangerous and surprising.

* emailed patches from Christoph Hellwig <hch@lst.de>:
  maccess: make get_kernel_nofault() check for minimal type compatibility
  maccess: rename probe_kernel_address to get_kernel_nofault
  maccess: rename probe_user_{read,write} to copy_{from,to}_user_nofault
  maccess: rename probe_kernel_{read,write} to copy_{from,to}_kernel_nofault
2020-06-18 12:35:51 -07:00
Kaitao Cheng 026bb845b0 ftrace: Fix maybe-uninitialized compiler warning
During build compiler reports some 'false positive' warnings about
variables {'seq_ops', 'filtered_pids', 'other_pids'} may be used
uninitialized. This patch silences these warnings.
Also delete some useless spaces

Link: https://lkml.kernel.org/r/20200529141214.37648-1-pilgrimtao@gmail.com

Signed-off-by: Kaitao Cheng <pilgrimtao@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-06-17 17:13:18 -04:00
David S. Miller b9d37bbb55 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Alexei Starovoitov says:

====================
pull-request: bpf 2020-06-17

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

We've added 10 non-merge commits during the last 2 day(s) which contain
a total of 14 files changed, 158 insertions(+), 59 deletions(-).

The main changes are:

1) Important fix for bpf_probe_read_kernel_str() return value, from Andrii.

2) [gs]etsockopt fix for large optlen, from Stanislav.

3) devmap allocation fix, from Toke.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-17 13:26:55 -07:00
Christoph Hellwig c0ee37e85e maccess: rename probe_user_{read,write} to copy_{from,to}_user_nofault
Better describe what these functions do.

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-17 10:57:41 -07:00
Christoph Hellwig fe557319aa maccess: rename probe_kernel_{read,write} to copy_{from,to}_kernel_nofault
Better describe what these functions do.

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-17 10:57:41 -07:00
Andrii Nakryiko 02553b91da bpf: bpf_probe_read_kernel_str() has to return amount of data read on success
During recent refactorings, bpf_probe_read_kernel_str() started returning 0 on
success, instead of amount of data successfully read. This majorly breaks
applications relying on bpf_probe_read_kernel_str() and bpf_probe_read_str()
and their results. Fix this by returning actual number of bytes read.

Fixes: 8d92db5c04 ("bpf: rework the compat kernel probe handling")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20200616050432.1902042-1-andriin@fb.com
2020-06-17 17:50:02 +02:00
Jan Kara c3dbe541ef blktrace: Avoid sparse warnings when assigning q->blk_trace
Mostly for historical reasons, q->blk_trace is assigned through xchg()
and cmpxchg() atomic operations. Although this is correct, sparse
complains about this because it violates rcu annotations since commit
c780e86dd4 ("blktrace: Protect q->blk_trace with RCU") which started
to use rcu for accessing q->blk_trace. Furthermore there's no real need
for atomic operations anymore since all changes to q->blk_trace happen
under q->blk_trace_mutex and since it also makes more sense to check if
q->blk_trace is set with the mutex held earlier.

So let's just replace xchg() with rcu_replace_pointer() and cmpxchg()
with explicit check and rcu_assign_pointer(). This makes the code more
efficient and sparse happy.

Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-17 09:07:11 -06:00
Luis Chamberlain 1b0b283648 blktrace: break out of blktrace setup on concurrent calls
We use one blktrace per request_queue, that means one per the entire
disk.  So we cannot run one blktrace on say /dev/vda and then /dev/vda1,
or just two calls on /dev/vda.

We check for concurrent setup only at the very end of the blktrace setup though.

If we try to run two concurrent blktraces on the same block device the
second one will fail, and the first one seems to go on. However when
one tries to kill the first one one will see things like this:

The kernel will show these:

```
debugfs: File 'dropped' in directory 'nvme1n1' already present!
debugfs: File 'msg' in directory 'nvme1n1' already present!
debugfs: File 'trace0' in directory 'nvme1n1' already present!
``

And userspace just sees this error message for the second call:

```
blktrace /dev/nvme1n1
BLKTRACESETUP(2) /dev/nvme1n1 failed: 5/Input/output error
```

The first userspace process #1 will also claim that the files
were taken underneath their nose as well. The files are taken
away form the first process given that when the second blktrace
fails, it will follow up with a BLKTRACESTOP and BLKTRACETEARDOWN.
This means that even if go-happy process #1 is waiting for blktrace
data, we *have* been asked to take teardown the blktrace.

This can easily be reproduced with break-blktrace [0] run_0005.sh test.

Just break out early if we know we're already going to fail, this will
prevent trying to create the files all over again, which we know still
exist.

[0] https://github.com/mcgrof/break-blktrace

Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-17 09:07:11 -06:00
YangHui 69243720c0 tracing: Remove unused event variable in tracing_iter_reset
We do not use the event variable, just remove it.

Signed-off-by: YangHui <yanghui.def@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-06-16 21:21:03 -04:00
Vamshi K Sthambamkadi 3aa8fdc37d tracing/probe: Fix memleak in fetch_op_data operations
kmemleak report:
    [<57dcc2ca>] __kmalloc_track_caller+0x139/0x2b0
    [<f1c45d0f>] kstrndup+0x37/0x80
    [<f9761eb0>] parse_probe_arg.isra.7+0x3cc/0x630
    [<055bf2ba>] traceprobe_parse_probe_arg+0x2f5/0x810
    [<655a7766>] trace_kprobe_create+0x2ca/0x950
    [<4fc6a02a>] create_or_delete_trace_kprobe+0xf/0x30
    [<6d1c8a52>] trace_run_command+0x67/0x80
    [<be812cc0>] trace_parse_run_command+0xa7/0x140
    [<aecfe401>] probes_write+0x10/0x20
    [<2027641c>] __vfs_write+0x30/0x1e0
    [<6a4aeee1>] vfs_write+0x96/0x1b0
    [<3517fb7d>] ksys_write+0x53/0xc0
    [<dad91db7>] __ia32_sys_write+0x15/0x20
    [<da347f64>] do_syscall_32_irqs_on+0x3d/0x260
    [<fd0b7e7d>] do_fast_syscall_32+0x39/0xb0
    [<ea5ae810>] entry_SYSENTER_32+0xaf/0x102

Post parse_probe_arg(), the FETCH_OP_DATA operation type is overwritten
to FETCH_OP_ST_STRING, as a result memory is never freed since
traceprobe_free_probe_arg() iterates only over SYMBOL and DATA op types

Setup fetch string operation correctly after fetch_op_data operation.

Link: https://lkml.kernel.org/r/20200615143034.GA1734@cosmos

Cc: stable@vger.kernel.org
Fixes: a42e3c4de9 ("tracing/probe: Add immediate string parameter support")
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Vamshi K Sthambamkadi <vamshi.k.sthambamkadi@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-06-16 21:21:02 -04:00
Wei Yang 48a42f5d13 trace: Fix typo in allocate_ftrace_ops()'s comment
No functional change, just correct the word.

Link: https://lkml.kernel.org/r/20200610033251.31713-1-richard.weiyang@linux.alibaba.com

Signed-off-by: Wei Yang <richard.weiyang@linux.alibaba.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-06-16 21:21:02 -04:00
Steven Rostedt (VMware) 4649079b9d tracing: Make ftrace packed events have align of 1
When using trace-cmd on 5.6-rt for the function graph tracer, the output was
corrupted. It gave output like this:

 funcgraph_entry:       func=0xffffffff depth=38982
 funcgraph_entry:       func=0x1ffffffff depth=16044
 funcgraph_exit:        func=0xffffffff overrun=0x92539aaf00000000 calltime=0x92539c9900000072 rettime=0x100000072 depth=11084
 funcgraph_exit:        func=0xffffffff overrun=0x9253946e00000000 calltime=0x92539e2100000072 rettime=0x72 depth=26033702
 funcgraph_entry:       func=0xffffffff depth=85798
 funcgraph_entry:       func=0x1ffffffff depth=12044

The reason was because the tracefs/events/ftrace/funcgraph_entry/exit format
file was incorrect. The -rt kernel adds more common fields to the trace
events. Namely, common_migrate_disable and common_preempt_lazy_count. Each
is one byte in size. This changes the alignment of the normal payload. Most
events are aligned normally, but the function and function graph events are
defined with a "PACKED" macro, that packs their payload. As the offsets
displayed in the format files are now calculated by an aligned field, the
aligned field for function and function graph events should be 1, not their
normal alignment.

With aligning of the funcgraph_entry event, the format file has:

        field:unsigned short common_type;       offset:0;       size:2; signed:0;
        field:unsigned char common_flags;       offset:2;       size:1; signed:0;
        field:unsigned char common_preempt_count;       offset:3;       size:1; signed:0;
        field:int common_pid;   offset:4;       size:4; signed:1;
        field:unsigned char common_migrate_disable;     offset:8;       size:1; signed:0;
        field:unsigned char common_preempt_lazy_count;  offset:9;       size:1; signed:0;

        field:unsigned long func;       offset:16;      size:8; signed:0;
        field:int depth;        offset:24;      size:4; signed:1;

But the actual alignment is:

	field:unsigned short common_type;	offset:0;	size:2;	signed:0;
	field:unsigned char common_flags;	offset:2;	size:1;	signed:0;
	field:unsigned char common_preempt_count;	offset:3;	size:1;	signed:0;
	field:int common_pid;	offset:4;	size:4;	signed:1;
	field:unsigned char common_migrate_disable;	offset:8;	size:1;	signed:0;
	field:unsigned char common_preempt_lazy_count;	offset:9;	size:1;	signed:0;

	field:unsigned long func;	offset:12;	size:8;	signed:0;
	field:int depth;	offset:20;	size:4;	signed:1;

Link: https://lkml.kernel.org/r/20200609220041.2a3b527f@oasis.local.home

Cc: stable@vger.kernel.org
Fixes: 04ae87a520 ("ftrace: Rework event_create_dir()")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-06-16 21:21:02 -04:00
Gustavo A. R. Silva 7fac96f2be tracing/probe: Replace zero-length array with flexible-array
There is a regular need in the kernel to provide a way to declare having a
dynamically sized set of trailing elements in a structure. Kernel code should
always use “flexible array members”[1] for these cases. The older style of
one-element or zero-length arrays should no longer be used[2].

[1] https://en.wikipedia.org/wiki/Flexible_array_member
[2] https://github.com/KSPP/linux/issues/21

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2020-06-15 23:08:32 -05:00
Adrian Hunter 548e1f6c76 ftrace: Add perf text poke events for ftrace trampolines
Add perf text poke events for ftrace trampolines when created and when
freed.

There can be 3 text_poke events for ftrace trampolines:

1. NULL -> trampoline
   By ftrace_update_trampoline() when !ops->trampoline
   Trampoline created

2. [e.g. on x86] CALL rel32 -> CALL rel32
   By arch_ftrace_update_trampoline() when ops->trampoline and
                        ops->flags & FTRACE_OPS_FL_ALLOC_TRAMP
   [e.g. on x86] via text_poke_bp() which generates text poke events
   Trampoline-called function target updated

3. trampoline -> NULL
   By ftrace_trampoline_free() when ops->trampoline and
                 ops->flags & FTRACE_OPS_FL_ALLOC_TRAMP
   Trampoline freed

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200512121922.8997-9-adrian.hunter@intel.com
2020-06-15 14:09:50 +02:00
Adrian Hunter dd9ddf466a ftrace: Add perf ksymbol events for ftrace trampolines
Symbols are needed for tools to describe instruction addresses. Pages
allocated for ftrace's purposes need symbols to be created for them.
Add such symbols to be visible via perf ksymbol events.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200512121922.8997-8-adrian.hunter@intel.com
2020-06-15 14:09:49 +02:00
Adrian Hunter fc0ea795f5 ftrace: Add symbols for ftrace trampolines
Symbols are needed for tools to describe instruction addresses. Pages
allocated for ftrace's purposes need symbols to be created for them.
Add such symbols to be visible via /proc/kallsyms.

Example on x86 with CONFIG_DYNAMIC_FTRACE=y

	# echo function > /sys/kernel/debug/tracing/current_tracer
	# cat /proc/kallsyms | grep '\[__builtin__ftrace\]'
	ffffffffc0238000 t ftrace_trampoline    [__builtin__ftrace]

Note: This patch adds "__builtin__ftrace" as a module name in /proc/kallsyms for
symbols for pages allocated for ftrace's purposes, even though "__builtin__ftrace"
is not a module.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200512121922.8997-7-adrian.hunter@intel.com
2020-06-15 14:09:49 +02:00
Linus Torvalds 96144c58ab Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Pull networking fixes from David Miller:

 1) Fix cfg80211 deadlock, from Johannes Berg.

 2) RXRPC fails to send norigications, from David Howells.

 3) MPTCP RM_ADDR parsing has an off by one pointer error, fix from
    Geliang Tang.

 4) Fix crash when using MSG_PEEK with sockmap, from Anny Hu.

 5) The ucc_geth driver needs __netdev_watchdog_up exported, from
    Valentin Longchamp.

 6) Fix hashtable memory leak in dccp, from Wang Hai.

 7) Fix how nexthops are marked as FDB nexthops, from David Ahern.

 8) Fix mptcp races between shutdown and recvmsg, from Paolo Abeni.

 9) Fix crashes in tipc_disc_rcv(), from Tuong Lien.

10) Fix link speed reporting in iavf driver, from Brett Creeley.

11) When a channel is used for XSK and then reused again later for XSK,
    we forget to clear out the relevant data structures in mlx5 which
    causes all kinds of problems. Fix from Maxim Mikityanskiy.

12) Fix memory leak in genetlink, from Cong Wang.

13) Disallow sockmap attachments to UDP sockets, it simply won't work.
    From Lorenz Bauer.

* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (83 commits)
  net: ethernet: ti: ale: fix allmulti for nu type ale
  net: ethernet: ti: am65-cpsw-nuss: fix ale parameters init
  net: atm: Remove the error message according to the atomic context
  bpf: Undo internal BPF_PROBE_MEM in BPF insns dump
  libbpf: Support pre-initializing .bss global variables
  tools/bpftool: Fix skeleton codegen
  bpf: Fix memlock accounting for sock_hash
  bpf: sockmap: Don't attach programs to UDP sockets
  bpf: tcp: Recv() should return 0 when the peer socket is closed
  ibmvnic: Flush existing work items before device removal
  genetlink: clean up family attributes allocations
  net: ipa: header pad field only valid for AP->modem endpoint
  net: ipa: program upper nibbles of sequencer type
  net: ipa: fix modem LAN RX endpoint id
  net: ipa: program metadata mask differently
  ionic: add pcie_print_link_status
  rxrpc: Fix race between incoming ACK parser and retransmitter
  net/mlx5: E-Switch, Fix some error pointer dereferences
  net/mlx5: Don't fail driver on failure to create debugfs
  net/mlx5e: CT: Fix ipv6 nat header rewrite actions
  ...
2020-06-13 16:27:13 -07:00
Linus Torvalds 076f14be7f The X86 entry, exception and interrupt code rework
This all started about 6 month ago with the attempt to move the Posix CPU
 timer heavy lifting out of the timer interrupt code and just have lockless
 quick checks in that code path. Trivial 5 patches.
 
 This unearthed an inconsistency in the KVM handling of task work and the
 review requested to move all of this into generic code so other
 architectures can share.
 
 Valid request and solved with another 25 patches but those unearthed
 inconsistencies vs. RCU and instrumentation.
 
 Digging into this made it obvious that there are quite some inconsistencies
 vs. instrumentation in general. The int3 text poke handling in particular
 was completely unprotected and with the batched update of trace events even
 more likely to expose to endless int3 recursion.
 
 In parallel the RCU implications of instrumenting fragile entry code came
 up in several discussions.
 
 The conclusion of the X86 maintainer team was to go all the way and make
 the protection against any form of instrumentation of fragile and dangerous
 code pathes enforcable and verifiable by tooling.
 
 A first batch of preparatory work hit mainline with commit d5f744f9a2.
 
 The (almost) full solution introduced a new code section '.noinstr.text'
 into which all code which needs to be protected from instrumentation of all
 sorts goes into. Any call into instrumentable code out of this section has
 to be annotated. objtool has support to validate this. Kprobes now excludes
 this section fully which also prevents BPF from fiddling with it and all
 'noinstr' annotated functions also keep ftrace off. The section, kprobes
 and objtool changes are already merged.
 
 The major changes coming with this are:
 
     - Preparatory cleanups
 
     - Annotating of relevant functions to move them into the noinstr.text
       section or enforcing inlining by marking them __always_inline so the
       compiler cannot misplace or instrument them.
 
     - Splitting and simplifying the idtentry macro maze so that it is now
       clearly separated into simple exception entries and the more
       interesting ones which use interrupt stacks and have the paranoid
       handling vs. CR3 and GS.
 
     - Move quite some of the low level ASM functionality into C code:
 
        - enter_from and exit to user space handling. The ASM code now calls
          into C after doing the really necessary ASM handling and the return
 	 path goes back out without bells and whistels in ASM.
 
        - exception entry/exit got the equivivalent treatment
 
        - move all IRQ tracepoints from ASM to C so they can be placed as
          appropriate which is especially important for the int3 recursion
          issue.
 
     - Consolidate the declaration and definition of entry points between 32
       and 64 bit. They share a common header and macros now.
 
     - Remove the extra device interrupt entry maze and just use the regular
       exception entry code.
 
     - All ASM entry points except NMI are now generated from the shared header
       file and the corresponding macros in the 32 and 64 bit entry ASM.
 
     - The C code entry points are consolidated as well with the help of
       DEFINE_IDTENTRY*() macros. This allows to ensure at one central point
       that all corresponding entry points share the same semantics. The
       actual function body for most entry points is in an instrumentable
       and sane state.
 
       There are special macros for the more sensitive entry points,
       e.g. INT3 and of course the nasty paranoid #NMI, #MCE, #DB and #DF.
       They allow to put the whole entry instrumentation and RCU handling
       into safe places instead of the previous pray that it is correct
       approach.
 
     - The INT3 text poke handling is now completely isolated and the
       recursion issue banned. Aside of the entry rework this required other
       isolation work, e.g. the ability to force inline bsearch.
 
     - Prevent #DB on fragile entry code, entry relevant memory and disable
       it on NMI, #MC entry, which allowed to get rid of the nested #DB IST
       stack shifting hackery.
 
     - A few other cleanups and enhancements which have been made possible
       through this and already merged changes, e.g. consolidating and
       further restricting the IDT code so the IDT table becomes RO after
       init which removes yet another popular attack vector
 
     - About 680 lines of ASM maze are gone.
 
 There are a few open issues:
 
    - An escape out of the noinstr section in the MCE handler which needs
      some more thought but under the aspect that MCE is a complete
      trainwreck by design and the propability to survive it is low, this was
      not high on the priority list.
 
    - Paravirtualization
 
      When PV is enabled then objtool complains about a bunch of indirect
      calls out of the noinstr section. There are a few straight forward
      ways to fix this, but the other issues vs. general correctness were
      more pressing than parawitz.
 
    - KVM
 
      KVM is inconsistent as well. Patches have been posted, but they have
      not yet been commented on or picked up by the KVM folks.
 
    - IDLE
 
      Pretty much the same problems can be found in the low level idle code
      especially the parts where RCU stopped watching. This was beyond the
      scope of the more obvious and exposable problems and is on the todo
      list.
 
 The lesson learned from this brain melting exercise to morph the evolved
 code base into something which can be validated and understood is that once
 again the violation of the most important engineering principle
 "correctness first" has caused quite a few people to spend valuable time on
 problems which could have been avoided in the first place. The "features
 first" tinkering mindset really has to stop.
 
 With that I want to say thanks to everyone involved in contributing to this
 effort. Special thanks go to the following people (alphabetical order):
 
    Alexandre Chartre
    Andy Lutomirski
    Borislav Petkov
    Brian Gerst
    Frederic Weisbecker
    Josh Poimboeuf
    Juergen Gross
    Lai Jiangshan
    Macro Elver
    Paolo Bonzini
    Paul McKenney
    Peter Zijlstra
    Vitaly Kuznetsov
    Will Deacon
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Merge tag 'x86-entry-2020-06-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 entry updates from Thomas Gleixner:
 "The x86 entry, exception and interrupt code rework

  This all started about 6 month ago with the attempt to move the Posix
  CPU timer heavy lifting out of the timer interrupt code and just have
  lockless quick checks in that code path. Trivial 5 patches.

  This unearthed an inconsistency in the KVM handling of task work and
  the review requested to move all of this into generic code so other
  architectures can share.

  Valid request and solved with another 25 patches but those unearthed
  inconsistencies vs. RCU and instrumentation.

  Digging into this made it obvious that there are quite some
  inconsistencies vs. instrumentation in general. The int3 text poke
  handling in particular was completely unprotected and with the batched
  update of trace events even more likely to expose to endless int3
  recursion.

  In parallel the RCU implications of instrumenting fragile entry code
  came up in several discussions.

  The conclusion of the x86 maintainer team was to go all the way and
  make the protection against any form of instrumentation of fragile and
  dangerous code pathes enforcable and verifiable by tooling.

  A first batch of preparatory work hit mainline with commit
  d5f744f9a2 ("Pull x86 entry code updates from Thomas Gleixner")

  That (almost) full solution introduced a new code section
  '.noinstr.text' into which all code which needs to be protected from
  instrumentation of all sorts goes into. Any call into instrumentable
  code out of this section has to be annotated. objtool has support to
  validate this.

  Kprobes now excludes this section fully which also prevents BPF from
  fiddling with it and all 'noinstr' annotated functions also keep
  ftrace off. The section, kprobes and objtool changes are already
  merged.

  The major changes coming with this are:

    - Preparatory cleanups

    - Annotating of relevant functions to move them into the
      noinstr.text section or enforcing inlining by marking them
      __always_inline so the compiler cannot misplace or instrument
      them.

    - Splitting and simplifying the idtentry macro maze so that it is
      now clearly separated into simple exception entries and the more
      interesting ones which use interrupt stacks and have the paranoid
      handling vs. CR3 and GS.

    - Move quite some of the low level ASM functionality into C code:

       - enter_from and exit to user space handling. The ASM code now
         calls into C after doing the really necessary ASM handling and
         the return path goes back out without bells and whistels in
         ASM.

       - exception entry/exit got the equivivalent treatment

       - move all IRQ tracepoints from ASM to C so they can be placed as
         appropriate which is especially important for the int3
         recursion issue.

    - Consolidate the declaration and definition of entry points between
      32 and 64 bit. They share a common header and macros now.

    - Remove the extra device interrupt entry maze and just use the
      regular exception entry code.

    - All ASM entry points except NMI are now generated from the shared
      header file and the corresponding macros in the 32 and 64 bit
      entry ASM.

    - The C code entry points are consolidated as well with the help of
      DEFINE_IDTENTRY*() macros. This allows to ensure at one central
      point that all corresponding entry points share the same
      semantics. The actual function body for most entry points is in an
      instrumentable and sane state.

      There are special macros for the more sensitive entry points, e.g.
      INT3 and of course the nasty paranoid #NMI, #MCE, #DB and #DF.
      They allow to put the whole entry instrumentation and RCU handling
      into safe places instead of the previous pray that it is correct
      approach.

    - The INT3 text poke handling is now completely isolated and the
      recursion issue banned. Aside of the entry rework this required
      other isolation work, e.g. the ability to force inline bsearch.

    - Prevent #DB on fragile entry code, entry relevant memory and
      disable it on NMI, #MC entry, which allowed to get rid of the
      nested #DB IST stack shifting hackery.

    - A few other cleanups and enhancements which have been made
      possible through this and already merged changes, e.g.
      consolidating and further restricting the IDT code so the IDT
      table becomes RO after init which removes yet another popular
      attack vector

    - About 680 lines of ASM maze are gone.

  There are a few open issues:

   - An escape out of the noinstr section in the MCE handler which needs
     some more thought but under the aspect that MCE is a complete
     trainwreck by design and the propability to survive it is low, this
     was not high on the priority list.

   - Paravirtualization

     When PV is enabled then objtool complains about a bunch of indirect
     calls out of the noinstr section. There are a few straight forward
     ways to fix this, but the other issues vs. general correctness were
     more pressing than parawitz.

   - KVM

     KVM is inconsistent as well. Patches have been posted, but they
     have not yet been commented on or picked up by the KVM folks.

   - IDLE

     Pretty much the same problems can be found in the low level idle
     code especially the parts where RCU stopped watching. This was
     beyond the scope of the more obvious and exposable problems and is
     on the todo list.

  The lesson learned from this brain melting exercise to morph the
  evolved code base into something which can be validated and understood
  is that once again the violation of the most important engineering
  principle "correctness first" has caused quite a few people to spend
  valuable time on problems which could have been avoided in the first
  place. The "features first" tinkering mindset really has to stop.

  With that I want to say thanks to everyone involved in contributing to
  this effort. Special thanks go to the following people (alphabetical
  order): Alexandre Chartre, Andy Lutomirski, Borislav Petkov, Brian
  Gerst, Frederic Weisbecker, Josh Poimboeuf, Juergen Gross, Lai
  Jiangshan, Macro Elver, Paolo Bonzin,i Paul McKenney, Peter Zijlstra,
  Vitaly Kuznetsov, and Will Deacon"

* tag 'x86-entry-2020-06-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (142 commits)
  x86/entry: Force rcu_irq_enter() when in idle task
  x86/entry: Make NMI use IDTENTRY_RAW
  x86/entry: Treat BUG/WARN as NMI-like entries
  x86/entry: Unbreak __irqentry_text_start/end magic
  x86/entry: __always_inline CR2 for noinstr
  lockdep: __always_inline more for noinstr
  x86/entry: Re-order #DB handler to avoid *SAN instrumentation
  x86/entry: __always_inline arch_atomic_* for noinstr
  x86/entry: __always_inline irqflags for noinstr
  x86/entry: __always_inline debugreg for noinstr
  x86/idt: Consolidate idt functionality
  x86/idt: Cleanup trap_init()
  x86/idt: Use proper constants for table size
  x86/idt: Add comments about early #PF handling
  x86/idt: Mark init only functions __init
  x86/entry: Rename trace_hardirqs_off_prepare()
  x86/entry: Clarify irq_{enter,exit}_rcu()
  x86/entry: Remove DBn stacks
  x86/entry: Remove debug IDT frobbing
  x86/entry: Optimize local_db_save() for virt
  ...
2020-06-13 10:05:47 -07:00
Linus Torvalds b791d1bdf9 The Kernel Concurrency Sanitizer (KCSAN)
KCSAN is a dynamic race detector, which relies on compile-time
 instrumentation, and uses a watchpoint-based sampling approach to detect
 races.
 
 The feature was under development for quite some time and has already found
 legitimate bugs.
 
 Unfortunately it comes with a limitation, which was only understood late in
 the development cycle:
 
   It requires an up to date CLANG-11 compiler
 
 CLANG-11 is not yet released (scheduled for June), but it's the only
 compiler today which handles the kernel requirements and especially the
 annotations of functions to exclude them from KCSAN instrumentation
 correctly.
 
 These annotations really need to work so that low level entry code and
 especially int3 text poke handling can be completely isolated.
 
 A detailed discussion of the requirements and compiler issues can be found
 here:
 
   https://lore.kernel.org/lkml/CANpmjNMTsY_8241bS7=XAfqvZHFLrVEkv_uM4aDUWE_kh3Rvbw@mail.gmail.com/
 
 We came to the conclusion that trying to work around compiler limitations
 and bugs again would end up in a major trainwreck, so requiring a working
 compiler seemed to be the best choice.
 
 For Continous Integration purposes the compiler restriction is manageable
 and that's where most xxSAN reports come from.
 
 For a change this limitation might make GCC people actually look at their
 bugs. Some issues with CSAN in GCC are 7 years old and one has been 'fixed'
 3 years ago with a half baken solution which 'solved' the reported issue
 but not the underlying problem.
 
 The KCSAN developers also ponder to use a GCC plugin to become independent,
 but that's not something which will show up in a few days.
 
 Blocking KCSAN until wide spread compiler support is available is not a
 really good alternative because the continuous growth of lockless
 optimizations in the kernel demands proper tooling support.
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Merge tag 'locking-kcsan-2020-06-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull the Kernel Concurrency Sanitizer from Thomas Gleixner:
 "The Kernel Concurrency Sanitizer (KCSAN) is a dynamic race detector,
  which relies on compile-time instrumentation, and uses a
  watchpoint-based sampling approach to detect races.

  The feature was under development for quite some time and has already
  found legitimate bugs.

  Unfortunately it comes with a limitation, which was only understood
  late in the development cycle:

     It requires an up to date CLANG-11 compiler

  CLANG-11 is not yet released (scheduled for June), but it's the only
  compiler today which handles the kernel requirements and especially
  the annotations of functions to exclude them from KCSAN
  instrumentation correctly.

  These annotations really need to work so that low level entry code and
  especially int3 text poke handling can be completely isolated.

  A detailed discussion of the requirements and compiler issues can be
  found here:

    https://lore.kernel.org/lkml/CANpmjNMTsY_8241bS7=XAfqvZHFLrVEkv_uM4aDUWE_kh3Rvbw@mail.gmail.com/

  We came to the conclusion that trying to work around compiler
  limitations and bugs again would end up in a major trainwreck, so
  requiring a working compiler seemed to be the best choice.

  For Continous Integration purposes the compiler restriction is
  manageable and that's where most xxSAN reports come from.

  For a change this limitation might make GCC people actually look at
  their bugs. Some issues with CSAN in GCC are 7 years old and one has
  been 'fixed' 3 years ago with a half baken solution which 'solved' the
  reported issue but not the underlying problem.

  The KCSAN developers also ponder to use a GCC plugin to become
  independent, but that's not something which will show up in a few
  days.

  Blocking KCSAN until wide spread compiler support is available is not
  a really good alternative because the continuous growth of lockless
  optimizations in the kernel demands proper tooling support"

* tag 'locking-kcsan-2020-06-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (76 commits)
  compiler_types.h, kasan: Use __SANITIZE_ADDRESS__ instead of CONFIG_KASAN to decide inlining
  compiler.h: Move function attributes to compiler_types.h
  compiler.h: Avoid nested statement expression in data_race()
  compiler.h: Remove data_race() and unnecessary checks from {READ,WRITE}_ONCE()
  kcsan: Update Documentation to change supported compilers
  kcsan: Remove 'noinline' from __no_kcsan_or_inline
  kcsan: Pass option tsan-instrument-read-before-write to Clang
  kcsan: Support distinguishing volatile accesses
  kcsan: Restrict supported compilers
  kcsan: Avoid inserting __tsan_func_entry/exit if possible
  ubsan, kcsan: Don't combine sanitizer with kcov on clang
  objtool, kcsan: Add kcsan_disable_current() and kcsan_enable_current_nowarn()
  kcsan: Add __kcsan_{enable,disable}_current() variants
  checkpatch: Warn about data_race() without comment
  kcsan: Use GFP_ATOMIC under spin lock
  Improve KCSAN documentation a bit
  kcsan: Make reporting aware of KCSAN tests
  kcsan: Fix function matching in report
  kcsan: Change data_race() to no longer require marking racing accesses
  kcsan: Move kcsan_{disable,enable}_current() to kcsan-checks.h
  ...
2020-06-11 18:55:43 -07:00
Linus Torvalds a58dfea297 block-5.8-2020-06-11
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Merge tag 'block-5.8-2020-06-11' of git://git.kernel.dk/linux-block

Pull block fixes from Jens Axboe:
 "Some followup fixes for this merge window. In particular:

   - Seqcount write missing preemption disable for stats (Ahmed)

   - blktrace fixes (Chaitanya)

   - Redundant initializations (Colin)

   - Various small NVMe fixes (Chaitanya, Christoph, Daniel, Max,
     Niklas, Rikard)

   - loop flag bug regression fix (Martijn)

   - blk-mq tagging fixes (Christoph, Ming)"

* tag 'block-5.8-2020-06-11' of git://git.kernel.dk/linux-block:
  umem: remove redundant initialization of variable ret
  pktcdvd: remove redundant initialization of variable ret
  nvmet: fail outstanding host posted AEN req
  nvme-pci: use simple suspend when a HMB is enabled
  nvme-fc: don't call nvme_cleanup_cmd() for AENs
  nvmet-tcp: constify nvmet_tcp_ops
  nvme-tcp: constify nvme_tcp_mq_ops and nvme_tcp_admin_mq_ops
  nvme: do not call del_gendisk() on a disk that was never added
  blk-mq: fix blk_mq_all_tag_iter
  blk-mq: split out a __blk_mq_get_driver_tag helper
  blktrace: fix endianness for blk_log_remap()
  blktrace: fix endianness in get_pdu_int()
  blktrace: use errno instead of bi_status
  block: nr_sects_write(): Disable preemption on seqcount write
  block: remove the error argument to the block_bio_complete tracepoint
  loop: Fix wrong masking of status flags
  block/bio-integrity: don't free 'buf' if bio_integrity_add_page() failed
2020-06-11 16:07:33 -07:00
Thomas Gleixner 37d1a04b13 Rebase locking/kcsan to locking/urgent
Merge the state of the locking kcsan branch before the read/write_once()
and the atomics modifications got merged.

Squash the fallout of the rebase on top of the read/write once and atomic
fallback work into the merge. The history of the original branch is
preserved in tag locking-kcsan-2020-06-02.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2020-06-11 20:02:46 +02:00
Peter Zijlstra bf2b300844 x86/entry: Rename trace_hardirqs_off_prepare()
The typical pattern for trace_hardirqs_off_prepare() is:

  ENTRY
    lockdep_hardirqs_off(); // because hardware
    ... do entry magic
    instrumentation_begin();
    trace_hardirqs_off_prepare();
    ... do actual work
    trace_hardirqs_on_prepare();
    lockdep_hardirqs_on_prepare();
    instrumentation_end();
    ... do exit magic
    lockdep_hardirqs_on();

which shows that it's named wrong, rename it to
trace_hardirqs_off_finish(), as it concludes the hardirq_off transition.

Also, given that the above is the only correct order, make the traditional
all-in-one trace_hardirqs_off() follow suit.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20200529213321.415774872@infradead.org
2020-06-11 15:15:24 +02:00
Linus Torvalds 1c38372662 Merge branch 'work.sysctl' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull sysctl fixes from Al Viro:
 "Fixups to regressions in sysctl series"

* 'work.sysctl' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  sysctl: reject gigantic reads/write to sysctl files
  cdrom: fix an incorrect __user annotation on cdrom_sysctl_info
  trace: fix an incorrect __user annotation on stack_trace_sysctl
  random: fix an incorrect __user annotation on proc_do_entropy
  net/sysctl: remove leftover __user annotations on neigh_proc_dointvec*
  net/sysctl: use cpumask_parse in flow_limit_cpu_sysctl
2020-06-10 16:05:54 -07:00
Jean-Philippe Brucker 22d5bd6867 tracing/probe: Fix bpf_task_fd_query() for kprobes and uprobes
Commit 60d53e2c3b ("tracing/probe: Split trace_event related data from
trace_probe") removed the trace_[ku]probe structure from the
trace_event_call->data pointer. As bpf_get_[ku]probe_info() were
forgotten in that change, fix them now. These functions are currently
only used by the bpf_task_fd_query() syscall handler to collect
information about a perf event.

Fixes: 60d53e2c3b ("tracing/probe: Split trace_event related data from trace_probe")
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Link: https://lore.kernel.org/bpf/20200608124531.819838-1-jean-philippe@linaro.org
2020-06-09 11:10:12 -07:00
Linus Torvalds d1e521adad Tracing updates for 5.8:
No new features this release. Mostly clean ups, restructuring and
 documentation.
 
  - Have ftrace_bug() show ftrace errors before the WARN, as the WARN will
    reboot the box before the error messages are printed if panic_on_warn
    is set.
 
  - Have traceoff_on_warn disable tracing sooner (before prints)
 
  - Write a message to the trace buffer that its being disabled when
    disable_trace_on_warning() is set.
 
  - Separate out synthetic events from histogram code to let it be used by
    other parts of the kernel.
 
  - More documentation on histogram design.
 
  - Other small fixes and clean ups.
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Merge tag 'trace-v5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:
 "No new features this release. Mostly clean ups, restructuring and
  documentation.

   - Have ftrace_bug() show ftrace errors before the WARN, as the WARN
     will reboot the box before the error messages are printed if
     panic_on_warn is set.

   - Have traceoff_on_warn disable tracing sooner (before prints)

   - Write a message to the trace buffer that its being disabled when
     disable_trace_on_warning() is set.

   - Separate out synthetic events from histogram code to let it be used
     by other parts of the kernel.

   - More documentation on histogram design.

   - Other small fixes and clean ups"

* tag 'trace-v5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Remove obsolete PREEMPTIRQ_EVENTS kconfig option
  tracing/doc: Fix ascii-art in histogram-design.rst
  tracing: Add a trace print when traceoff_on_warning is triggered
  ftrace,bug: Improve traceoff_on_warn
  selftests/ftrace: Distinguish between hist and synthetic event checks
  tracing: Move synthetic events to a separate file
  tracing: Fix events.rst section numbering
  tracing/doc: Fix typos in histogram-design.rst
  tracing: Add hist_debug trace event files for histogram debugging
  tracing: Add histogram-design document
  tracing: Check state.disabled in synth event trace functions
  tracing/probe: reverse arguments to list_add
  tools/bootconfig: Add a summary of test cases and return error
  ftrace: show debugging information when panic_on_warn set
2020-06-09 10:06:18 -07:00
Christoph Hellwig 98a23609b1 maccess: always use strict semantics for probe_kernel_read
Except for historical confusion in the kprobes/uprobes and bpf tracers,
which has been fixed now, there is no good reason to ever allow user
memory accesses from probe_kernel_read.  Switch probe_kernel_read to only
read from kernel memory.

[akpm@linux-foundation.org: update it for "mm, dump_page(): do not crash with invalid mapping pointer"]

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20200521152301.2587579-17-hch@lst.de
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-09 09:39:15 -07:00
Christoph Hellwig 9de1fec50b tracing/kprobes: handle mixed kernel/userspace probes better
Instead of using the dangerous probe_kernel_read and strncpy_from_unsafe
helpers, rework probes to try a user probe based on the address if the
architecture has a common address space for kernel and userspace.

[svens@linux.ibm.com:use strncpy_from_kernel_nofault() in fetch_store_string()]
  Link: http://lkml.kernel.org/r/20200606181903.49384-1-svens@linux.ibm.com

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20200521152301.2587579-15-hch@lst.de
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-09 09:39:15 -07:00
Christoph Hellwig 8d92db5c04 bpf: rework the compat kernel probe handling
Instead of using the dangerous probe_kernel_read and strncpy_from_unsafe
helpers, rework the compat probes to check if an address is a kernel or
userspace one, and then use the low-level kernel or user probe helper
shared by the proper kernel and user probe helpers.  This slightly
changes behavior as the compat probe on a user address doesn't check
the lockdown flags, just as the pure user probes do.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20200521152301.2587579-14-hch@lst.de
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-09 09:39:15 -07:00
Andrew Morton 19c8d8ac63 bpf:bpf_seq_printf(): handle potentially unsafe format string better
User the proper helper for kernel or userspace addresses based on
TASK_SIZE instead of the dangerous strncpy_from_unsafe function.

Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-09 09:39:15 -07:00
Christoph Hellwig aec6ce5913 bpf: handle the compat string in bpf_trace_copy_string better
User the proper helper for kernel or userspace addresses based on
TASK_SIZE instead of the dangerous strncpy_from_unsafe function.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20200521152301.2587579-13-hch@lst.de
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-09 09:39:15 -07:00
Christoph Hellwig d7b2977b81 bpf: factor out a bpf_trace_copy_string helper
Split out a helper to do the fault free access to the string pointer
to get it out of a crazy indentation level.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20200521152301.2587579-12-hch@lst.de
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-09 09:39:15 -07:00
Christoph Hellwig 02dddb160e maccess: rename strnlen_unsafe_user to strnlen_user_nofault
This matches the naming of strnlen_user, and also makes it more clear
what the function is supposed to do.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20200521152301.2587579-9-hch@lst.de
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-09 09:39:15 -07:00
Christoph Hellwig c4cb164426 maccess: rename strncpy_from_unsafe_strict to strncpy_from_kernel_nofault
This matches the naming of strncpy_from_user_nofault, and also makes it
more clear what the function is supposed to do.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20200521152301.2587579-8-hch@lst.de
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-09 09:39:15 -07:00
Christoph Hellwig bd88bb5d40 maccess: rename strncpy_from_unsafe_user to strncpy_from_user_nofault
This matches the naming of strncpy_from_user, and also makes it more
clear what the function is supposed to do.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20200521152301.2587579-7-hch@lst.de
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-09 09:39:15 -07:00
Michel Lespinasse d8ed45c5dc mmap locking API: use coccinelle to convert mmap_sem rwsem call sites
This change converts the existing mmap_sem rwsem calls to use the new mmap
locking API instead.

The change is generated using coccinelle with the following rule:

// spatch --sp-file mmap_lock_api.cocci --in-place --include-headers --dir .

@@
expression mm;
@@
(
-init_rwsem
+mmap_init_lock
|
-down_write
+mmap_write_lock
|
-down_write_killable
+mmap_write_lock_killable
|
-down_write_trylock
+mmap_write_trylock
|
-up_write
+mmap_write_unlock
|
-downgrade_write
+mmap_write_downgrade
|
-down_read
+mmap_read_lock
|
-down_read_killable
+mmap_read_lock_killable
|
-down_read_trylock
+mmap_read_trylock
|
-up_read
+mmap_read_unlock
)
-(&mm->mmap_sem)
+(mm)

Signed-off-by: Michel Lespinasse <walken@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Reviewed-by: Laurent Dufour <ldufour@linux.ibm.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Liam Howlett <Liam.Howlett@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ying Han <yinghan@google.com>
Link: http://lkml.kernel.org/r/20200520052908.204642-5-walken@google.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-09 09:39:14 -07:00
Dmitry Safonov 2062a4e8ae kallsyms/printk: add loglvl to print_ip_sym()
Patch series "Add log level to show_stack()", v3.

Add log level argument to show_stack().

Done in three stages:
1. Introducing show_stack_loglvl() for every architecture
2. Migrating old users with an explicit log level
3. Renaming show_stack_loglvl() into show_stack()

Justification:

- It's a design mistake to move a business-logic decision into platform
  realization detail.

- I have currently two patches sets that would benefit from this work:
  Removing console_loglevel jumps in sysrq driver [1] Hung task warning
  before panic [2] - suggested by Tetsuo (but he probably didn't realise
  what it would involve).

- While doing (1), (2) the backtraces were adjusted to headers and other
  messages for each situation - so there won't be a situation when the
  backtrace is printed, but the headers are missing because they have
  lesser log level (or the reverse).

- As the result in (2) plays with console_loglevel for kdb are removed.

The least important for upstream, but maybe still worth to note that every
company I've worked in so far had an off-list patch to print backtrace
with the needed log level (but only for the architecture they cared
about).  If you have other ideas how you will benefit from show_stack()
with a log level - please, reply to this cover letter.

See also discussion on v1:
https://lore.kernel.org/linux-riscv/20191106083538.z5nlpuf64cigxigh@pathway.suse.cz/

This patch (of 50):

print_ip_sym() needs to have a log level parameter to comply with other
parts being printed.  Otherwise, half of the expected backtrace would be
printed and other may be missing with some logging level.

The following callee(s) are using now the adjusted log level:
- microblaze/unwind: the same level as headers & userspace unwind.
  Note that pr_debug()'s there are for debugging the unwinder itself.
- nds32/traps: symbol addresses are printed with the same log level
  as backtrace headers.
- lockdep: ip for locking issues is printed with the same log level
  as other part of the warning.
- sched: ip where preemption was disabled is printed as error like
  the rest part of the message.
- ftrace: bug reports are now consistent in the log level being used.

Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Ben Segall <bsegall@google.com>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Hogan <jhogan@kernel.org>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Burton <paulburton@kernel.org>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vincent Chen <deanbo422@gmail.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Will Deacon <will@kernel.org>
Cc: Dmitry Safonov <0x7f454c46@gmail.com>
Cc: Dmitry Safonov <dima@arista.com>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Aurelien Jacquiot <jacquiot.aurelien@gmail.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Guo Ren <guoren@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Ley Foon Tan <lftan@altera.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Cc: Helge Deller <deller@gmx.de>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Rich Felker <dalias@libc.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Cc: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Douglas Anderson <dianders@chromium.org>
Cc: Jason Wessel <jason.wessel@windriver.com>
Link: http://lkml.kernel.org/r/20200418201944.482088-2-dima@arista.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-09 09:39:10 -07:00
Christoph Hellwig 7ff0d4490e trace: fix an incorrect __user annotation on stack_trace_sysctl
No user pointers for sysctls anymore.

Fixes: 32927393dc ("sysctl: pass kernel pointers to ->proc_handler")
Reported-by: build test robot <lkp@intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-06-08 10:13:56 -04:00
Mel Gorman 388d8bdb87 tracing: Remove obsolete PREEMPTIRQ_EVENTS kconfig option
The PREEMPTIRQ_EVENTS option is unused after commit c3bc8fd637 ("tracing:
Centralize preemptirq tracepoints and unify their usage"). Remove it.

Note that this option is hazardous as it stands. It enables TRACE_IRQFLAGS
event on non-preempt configurations without the irqsoff tracer enabled.
TRACE_IRQFLAGS as it stands incurs significant overhead on each IRQ
entry/exit. This is because trace_hardirqs_[on|off] does all the per-cpu
manipulations and NMI checks even if tracing is completely disabled for
some insane reason.  For example, netperf running UDP_STREAM on localhost
incurs a 4-6% performance penalty without any tracing if IRQFLAGS is
set. It can be put behind a static brach but even the function entry/exit
costs a little bit.

Link: https://lkml.kernel.org/r/20200409104034.GJ3818@techsingularity.net

Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-06-05 20:08:26 -04:00
Chaitanya Kulkarni 5aec598c45 blktrace: fix endianness for blk_log_remap()
The function blk_log_remap() can be simplified by removing the
call to get_pdu_remap() that copies the values into extra variable to
print the data, which also fixes the endiannness warning reported by
sparse.

Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-04 21:23:38 -06:00
Chaitanya Kulkarni 71df3fd82e blktrace: fix endianness in get_pdu_int()
In function get_pdu_len() replace variable type from __u64 to
__be64. This fixes sparse warning.

Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-04 21:23:38 -06:00
Chaitanya Kulkarni 48bc3cd3e0 blktrace: use errno instead of bi_status
In blk_add_trace_spliti() blk_add_trace_bio_remap() use
blk_status_to_errno() to pass the error instead of pasing the bi_status.
This fixes the sparse warning.

Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-04 21:23:38 -06:00
Christoph Hellwig d24de76af8 block: remove the error argument to the block_bio_complete tracepoint
The status can be trivially derived from the bio itself.  That also avoid
callers like NVMe to incorrectly pass a blk_status_t instead of the errno,
and the overhead of translating the blk_status_t to the errno in the I/O
completion fast path when no tracing is enabled.

Fixes: 35fe0d12c8 ("nvme: trace bio completion")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-04 21:16:11 -06:00
Linus Torvalds cb8e59cc87 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next
Pull networking updates from David Miller:

 1) Allow setting bluetooth L2CAP modes via socket option, from Luiz
    Augusto von Dentz.

 2) Add GSO partial support to igc, from Sasha Neftin.

 3) Several cleanups and improvements to r8169 from Heiner Kallweit.

 4) Add IF_OPER_TESTING link state and use it when ethtool triggers a
    device self-test. From Andrew Lunn.

 5) Start moving away from custom driver versions, use the globally
    defined kernel version instead, from Leon Romanovsky.

 6) Support GRO vis gro_cells in DSA layer, from Alexander Lobakin.

 7) Allow hard IRQ deferral during NAPI, from Eric Dumazet.

 8) Add sriov and vf support to hinic, from Luo bin.

 9) Support Media Redundancy Protocol (MRP) in the bridging code, from
    Horatiu Vultur.

10) Support netmap in the nft_nat code, from Pablo Neira Ayuso.

11) Allow UDPv6 encapsulation of ESP in the ipsec code, from Sabrina
    Dubroca. Also add ipv6 support for espintcp.

12) Lots of ReST conversions of the networking documentation, from Mauro
    Carvalho Chehab.

13) Support configuration of ethtool rxnfc flows in bcmgenet driver,
    from Doug Berger.

14) Allow to dump cgroup id and filter by it in inet_diag code, from
    Dmitry Yakunin.

15) Add infrastructure to export netlink attribute policies to
    userspace, from Johannes Berg.

16) Several optimizations to sch_fq scheduler, from Eric Dumazet.

17) Fallback to the default qdisc if qdisc init fails because otherwise
    a packet scheduler init failure will make a device inoperative. From
    Jesper Dangaard Brouer.

18) Several RISCV bpf jit optimizations, from Luke Nelson.

19) Correct the return type of the ->ndo_start_xmit() method in several
    drivers, it's netdev_tx_t but many drivers were using
    'int'. From Yunjian Wang.

20) Add an ethtool interface for PHY master/slave config, from Oleksij
    Rempel.

21) Add BPF iterators, from Yonghang Song.

22) Add cable test infrastructure, including ethool interfaces, from
    Andrew Lunn. Marvell PHY driver is the first to support this
    facility.

23) Remove zero-length arrays all over, from Gustavo A. R. Silva.

24) Calculate and maintain an explicit frame size in XDP, from Jesper
    Dangaard Brouer.

25) Add CAP_BPF, from Alexei Starovoitov.

26) Support terse dumps in the packet scheduler, from Vlad Buslov.

27) Support XDP_TX bulking in dpaa2 driver, from Ioana Ciornei.

28) Add devm_register_netdev(), from Bartosz Golaszewski.

29) Minimize qdisc resets, from Cong Wang.

30) Get rid of kernel_getsockopt and kernel_setsockopt in order to
    eliminate set_fs/get_fs calls. From Christoph Hellwig.

* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2517 commits)
  selftests: net: ip_defrag: ignore EPERM
  net_failover: fixed rollback in net_failover_open()
  Revert "tipc: Fix potential tipc_aead refcnt leak in tipc_crypto_rcv"
  Revert "tipc: Fix potential tipc_node refcnt leak in tipc_rcv"
  vmxnet3: allow rx flow hash ops only when rss is enabled
  hinic: add set_channels ethtool_ops support
  selftests/bpf: Add a default $(CXX) value
  tools/bpf: Don't use $(COMPILE.c)
  bpf, selftests: Use bpf_probe_read_kernel
  s390/bpf: Use bcr 0,%0 as tail call nop filler
  s390/bpf: Maintain 8-byte stack alignment
  selftests/bpf: Fix verifier test
  selftests/bpf: Fix sample_cnt shared between two threads
  bpf, selftests: Adapt cls_redirect to call csum_level helper
  bpf: Add csum_level helper for fixing up csum levels
  bpf: Fix up bpf_skb_adjust_room helper's skb csum setting
  sfc: add missing annotation for efx_ef10_try_update_nic_stats_vf()
  crypto/chtls: IPv6 support for inline TLS
  Crypto/chcr: Fixes a coccinile check error
  Crypto/chcr: Fixes compilations warnings
  ...
2020-06-03 16:27:18 -07:00
Linus Torvalds ae03c53d00 Merge branch 'work.splice' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull splice updates from Al Viro:
 "Christoph's assorted splice cleanups"

* 'work.splice' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  fs: rename pipe_buf ->steal to ->try_steal
  fs: make the pipe_buf_operations ->confirm operation optional
  fs: make the pipe_buf_operations ->steal operation optional
  trace: remove tracing_pipe_buf_ops
  pipe: merge anon_pipe_buf*_ops
  fs: simplify do_splice_from
  fs: simplify do_splice_to
2020-06-03 15:52:19 -07:00
Linus Torvalds 039aeb9deb ARM:
- Move the arch-specific code into arch/arm64/kvm
 - Start the post-32bit cleanup
 - Cherry-pick a few non-invasive pre-NV patches
 
 x86:
 - Rework of TLB flushing
 - Rework of event injection, especially with respect to nested virtualization
 - Nested AMD event injection facelift, building on the rework of generic code
 and fixing a lot of corner cases
 - Nested AMD live migration support
 - Optimization for TSC deadline MSR writes and IPIs
 - Various cleanups
 - Asynchronous page fault cleanups (from tglx, common topic branch with tip tree)
 - Interrupt-based delivery of asynchronous "page ready" events (host side)
 - Hyper-V MSRs and hypercalls for guest debugging
 - VMX preemption timer fixes
 
 s390:
 - Cleanups
 
 Generic:
 - switch vCPU thread wakeup from swait to rcuwait
 
 The other architectures, and the guest side of the asynchronous page fault
 work, will come next week.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull kvm updates from Paolo Bonzini:
 "ARM:
   - Move the arch-specific code into arch/arm64/kvm

   - Start the post-32bit cleanup

   - Cherry-pick a few non-invasive pre-NV patches

  x86:
   - Rework of TLB flushing

   - Rework of event injection, especially with respect to nested
     virtualization

   - Nested AMD event injection facelift, building on the rework of
     generic code and fixing a lot of corner cases

   - Nested AMD live migration support

   - Optimization for TSC deadline MSR writes and IPIs

   - Various cleanups

   - Asynchronous page fault cleanups (from tglx, common topic branch
     with tip tree)

   - Interrupt-based delivery of asynchronous "page ready" events (host
     side)

   - Hyper-V MSRs and hypercalls for guest debugging

   - VMX preemption timer fixes

  s390:
   - Cleanups

  Generic:
   - switch vCPU thread wakeup from swait to rcuwait

  The other architectures, and the guest side of the asynchronous page
  fault work, will come next week"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (256 commits)
  KVM: selftests: fix rdtsc() for vmx_tsc_adjust_test
  KVM: check userspace_addr for all memslots
  KVM: selftests: update hyperv_cpuid with SynDBG tests
  x86/kvm/hyper-v: Add support for synthetic debugger via hypercalls
  x86/kvm/hyper-v: enable hypercalls regardless of hypercall page
  x86/kvm/hyper-v: Add support for synthetic debugger interface
  x86/hyper-v: Add synthetic debugger definitions
  KVM: selftests: VMX preemption timer migration test
  KVM: nVMX: Fix VMX preemption timer migration
  x86/kvm/hyper-v: Explicitly align hcall param for kvm_hyperv_exit
  KVM: x86/pmu: Support full width counting
  KVM: x86/pmu: Tweak kvm_pmu_get_msr to pass 'struct msr_data' in
  KVM: x86: announce KVM_FEATURE_ASYNC_PF_INT
  KVM: x86: acknowledgment mechanism for async pf page ready notifications
  KVM: x86: interrupt based APF 'page ready' event delivery
  KVM: introduce kvm_read_guest_offset_cached()
  KVM: rename kvm_arch_can_inject_async_page_present() to kvm_arch_can_dequeue_async_page_present()
  KVM: x86: extend struct kvm_vcpu_pv_apf_data with token info
  Revert "KVM: async_pf: Fix #DF due to inject "Page not Present" and "Page Ready" exceptions simultaneously"
  KVM: VMX: Replace zero-length array with flexible-array
  ...
2020-06-03 15:13:47 -07:00
Linus Torvalds 750a02ab8d for-5.8/block-2020-06-01
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Merge tag 'for-5.8/block-2020-06-01' of git://git.kernel.dk/linux-block

Pull block updates from Jens Axboe:
 "Core block changes that have been queued up for this release:

   - Remove dead blk-throttle and blk-wbt code (Guoqing)

   - Include pid in blktrace note traces (Jan)

   - Don't spew I/O errors on wouldblock termination (me)

   - Zone append addition (Johannes, Keith, Damien)

   - IO accounting improvements (Konstantin, Christoph)

   - blk-mq hardware map update improvements (Ming)

   - Scheduler dispatch improvement (Salman)

   - Inline block encryption support (Satya)

   - Request map fixes and improvements (Weiping)

   - blk-iocost tweaks (Tejun)

   - Fix for timeout failing with error injection (Keith)

   - Queue re-run fixes (Douglas)

   - CPU hotplug improvements (Christoph)

   - Queue entry/exit improvements (Christoph)

   - Move DMA drain handling to the few drivers that use it (Christoph)

   - Partition handling cleanups (Christoph)"

* tag 'for-5.8/block-2020-06-01' of git://git.kernel.dk/linux-block: (127 commits)
  block: mark bio_wouldblock_error() bio with BIO_QUIET
  blk-wbt: rename __wbt_update_limits to wbt_update_limits
  blk-wbt: remove wbt_update_limits
  blk-throttle: remove tg_drain_bios
  blk-throttle: remove blk_throtl_drain
  null_blk: force complete for timeout request
  blk-mq: drain I/O when all CPUs in a hctx are offline
  blk-mq: add blk_mq_all_tag_iter
  blk-mq: open code __blk_mq_alloc_request in blk_mq_alloc_request_hctx
  blk-mq: use BLK_MQ_NO_TAG in more places
  blk-mq: rename BLK_MQ_TAG_FAIL to BLK_MQ_NO_TAG
  blk-mq: move more request initialization to blk_mq_rq_ctx_init
  blk-mq: simplify the blk_mq_get_request calling convention
  blk-mq: remove the bio argument to ->prepare_request
  nvme: force complete cancelled requests
  blk-mq: blk-mq: provide forced completion method
  block: fix a warning when blkdev.h is included for !CONFIG_BLOCK builds
  block: blk-crypto-fallback: remove redundant initialization of variable err
  block: reduce part_stat_lock() scope
  block: use __this_cpu_add() instead of access by smp_processor_id()
  ...
2020-06-02 15:29:19 -07:00
Linus Torvalds 94709049fb Merge branch 'akpm' (patches from Andrew)
Merge updates from Andrew Morton:
 "A few little subsystems and a start of a lot of MM patches.

  Subsystems affected by this patch series: squashfs, ocfs2, parisc,
  vfs. With mm subsystems: slab-generic, slub, debug, pagecache, gup,
  swap, memcg, pagemap, memory-failure, vmalloc, kasan"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (128 commits)
  kasan: move kasan_report() into report.c
  mm/mm_init.c: report kasan-tag information stored in page->flags
  ubsan: entirely disable alignment checks under UBSAN_TRAP
  kasan: fix clang compilation warning due to stack protector
  x86/mm: remove vmalloc faulting
  mm: remove vmalloc_sync_(un)mappings()
  x86/mm/32: implement arch_sync_kernel_mappings()
  x86/mm/64: implement arch_sync_kernel_mappings()
  mm/ioremap: track which page-table levels were modified
  mm/vmalloc: track which page-table levels were modified
  mm: add functions to track page directory modifications
  s390: use __vmalloc_node in stack_alloc
  powerpc: use __vmalloc_node in alloc_vm_stack
  arm64: use __vmalloc_node in arch_alloc_vmap_stack
  mm: remove vmalloc_user_node_flags
  mm: switch the test_vmalloc module to use __vmalloc_node
  mm: remove __vmalloc_node_flags_caller
  mm: remove both instances of __vmalloc_node_flags
  mm: remove the prot argument to __vmalloc_node
  mm: remove the pgprot argument to __vmalloc
  ...
2020-06-02 12:21:36 -07:00
Joerg Roedel 73f693c3a7 mm: remove vmalloc_sync_(un)mappings()
These functions are not needed anymore because the vmalloc and ioremap
mappings are now synchronized when they are created or torn down.

Remove all callers and function definitions.

Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Acked-by: Andy Lutomirski <luto@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Link: http://lkml.kernel.org/r/20200515140023.25469-7-joro@8bytes.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-02 10:59:12 -07:00
Jiri Olsa 958a3f2d2a bpf: Use tracing helpers for lsm programs
Currenty lsm uses bpf_tracing_func_proto helpers which do
not include stack trace or perf event output. It's useful
to have those for bpftrace lsm support [1].

Using tracing_prog_func_proto helpers for lsm programs.

[1] https://github.com/iovisor/bpftrace/pull/1347

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Cc: KP Singh <kpsingh@google.com>
Link: https://lore.kernel.org/bpf/20200531154255.896551-1-jolsa@kernel.org
2020-06-01 15:08:04 -07:00
Yonghong Song b36e62eb85 bpf: Use strncpy_from_unsafe_strict() in bpf_seq_printf() helper
In bpf_seq_printf() helper, when user specified a "%s" in the
format string, strncpy_from_unsafe() is used to read the actual string
to a buffer. The string could be a format string or a string in
the kernel data structure. It is really unlikely that the string
will reside in the user memory.

This is different from Commit b2a5212fb6 ("bpf: Restrict bpf_trace_printk()'s %s
usage and add %pks, %pus specifier") which still used
strncpy_from_unsafe() for "%s" to preserve the old behavior.

If in the future, bpf_seq_printf() indeed needs to read user
memory, we can implement "%pus" format string.

Based on discussion in [1], if the intent is to read kernel memory,
strncpy_from_unsafe_strict() should be used. So this patch
changed to use strncpy_from_unsafe_strict().

[1]: https://lore.kernel.org/bpf/20200521152301.2587579-1-hch@lst.de/T/

Fixes: 492e639f0c ("bpf: Add bpf_seq_printf and bpf_seq_write helpers")
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Cc: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/bpf/20200529004810.3352219-1-yhs@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2020-06-01 14:48:31 -07:00
Andrii Nakryiko 457f44363a bpf: Implement BPF ring buffer and verifier support for it
This commit adds a new MPSC ring buffer implementation into BPF ecosystem,
which allows multiple CPUs to submit data to a single shared ring buffer. On
the consumption side, only single consumer is assumed.

Motivation
----------
There are two distinctive motivators for this work, which are not satisfied by
existing perf buffer, which prompted creation of a new ring buffer
implementation.
  - more efficient memory utilization by sharing ring buffer across CPUs;
  - preserving ordering of events that happen sequentially in time, even
  across multiple CPUs (e.g., fork/exec/exit events for a task).

These two problems are independent, but perf buffer fails to satisfy both.
Both are a result of a choice to have per-CPU perf ring buffer.  Both can be
also solved by having an MPSC implementation of ring buffer. The ordering
problem could technically be solved for perf buffer with some in-kernel
counting, but given the first one requires an MPSC buffer, the same solution
would solve the second problem automatically.

Semantics and APIs
------------------
Single ring buffer is presented to BPF programs as an instance of BPF map of
type BPF_MAP_TYPE_RINGBUF. Two other alternatives considered, but ultimately
rejected.

One way would be to, similar to BPF_MAP_TYPE_PERF_EVENT_ARRAY, make
BPF_MAP_TYPE_RINGBUF could represent an array of ring buffers, but not enforce
"same CPU only" rule. This would be more familiar interface compatible with
existing perf buffer use in BPF, but would fail if application needed more
advanced logic to lookup ring buffer by arbitrary key. HASH_OF_MAPS addresses
this with current approach. Additionally, given the performance of BPF
ringbuf, many use cases would just opt into a simple single ring buffer shared
among all CPUs, for which current approach would be an overkill.

Another approach could introduce a new concept, alongside BPF map, to
represent generic "container" object, which doesn't necessarily have key/value
interface with lookup/update/delete operations. This approach would add a lot
of extra infrastructure that has to be built for observability and verifier
support. It would also add another concept that BPF developers would have to
familiarize themselves with, new syntax in libbpf, etc. But then would really
provide no additional benefits over the approach of using a map.
BPF_MAP_TYPE_RINGBUF doesn't support lookup/update/delete operations, but so
doesn't few other map types (e.g., queue and stack; array doesn't support
delete, etc).

The approach chosen has an advantage of re-using existing BPF map
infrastructure (introspection APIs in kernel, libbpf support, etc), being
familiar concept (no need to teach users a new type of object in BPF program),
and utilizing existing tooling (bpftool). For common scenario of using
a single ring buffer for all CPUs, it's as simple and straightforward, as
would be with a dedicated "container" object. On the other hand, by being
a map, it can be combined with ARRAY_OF_MAPS and HASH_OF_MAPS map-in-maps to
implement a wide variety of topologies, from one ring buffer for each CPU
(e.g., as a replacement for perf buffer use cases), to a complicated
application hashing/sharding of ring buffers (e.g., having a small pool of
ring buffers with hashed task's tgid being a look up key to preserve order,
but reduce contention).

Key and value sizes are enforced to be zero. max_entries is used to specify
the size of ring buffer and has to be a power of 2 value.

There are a bunch of similarities between perf buffer
(BPF_MAP_TYPE_PERF_EVENT_ARRAY) and new BPF ring buffer semantics:
  - variable-length records;
  - if there is no more space left in ring buffer, reservation fails, no
    blocking;
  - memory-mappable data area for user-space applications for ease of
    consumption and high performance;
  - epoll notifications for new incoming data;
  - but still the ability to do busy polling for new data to achieve the
    lowest latency, if necessary.

BPF ringbuf provides two sets of APIs to BPF programs:
  - bpf_ringbuf_output() allows to *copy* data from one place to a ring
    buffer, similarly to bpf_perf_event_output();
  - bpf_ringbuf_reserve()/bpf_ringbuf_commit()/bpf_ringbuf_discard() APIs
    split the whole process into two steps. First, a fixed amount of space is
    reserved. If successful, a pointer to a data inside ring buffer data area
    is returned, which BPF programs can use similarly to a data inside
    array/hash maps. Once ready, this piece of memory is either committed or
    discarded. Discard is similar to commit, but makes consumer ignore the
    record.

bpf_ringbuf_output() has disadvantage of incurring extra memory copy, because
record has to be prepared in some other place first. But it allows to submit
records of the length that's not known to verifier beforehand. It also closely
matches bpf_perf_event_output(), so will simplify migration significantly.

bpf_ringbuf_reserve() avoids the extra copy of memory by providing a memory
pointer directly to ring buffer memory. In a lot of cases records are larger
than BPF stack space allows, so many programs have use extra per-CPU array as
a temporary heap for preparing sample. bpf_ringbuf_reserve() avoid this needs
completely. But in exchange, it only allows a known constant size of memory to
be reserved, such that verifier can verify that BPF program can't access
memory outside its reserved record space. bpf_ringbuf_output(), while slightly
slower due to extra memory copy, covers some use cases that are not suitable
for bpf_ringbuf_reserve().

The difference between commit and discard is very small. Discard just marks
a record as discarded, and such records are supposed to be ignored by consumer
code. Discard is useful for some advanced use-cases, such as ensuring
all-or-nothing multi-record submission, or emulating temporary malloc()/free()
within single BPF program invocation.

Each reserved record is tracked by verifier through existing
reference-tracking logic, similar to socket ref-tracking. It is thus
impossible to reserve a record, but forget to submit (or discard) it.

bpf_ringbuf_query() helper allows to query various properties of ring buffer.
Currently 4 are supported:
  - BPF_RB_AVAIL_DATA returns amount of unconsumed data in ring buffer;
  - BPF_RB_RING_SIZE returns the size of ring buffer;
  - BPF_RB_CONS_POS/BPF_RB_PROD_POS returns current logical possition of
    consumer/producer, respectively.
Returned values are momentarily snapshots of ring buffer state and could be
off by the time helper returns, so this should be used only for
debugging/reporting reasons or for implementing various heuristics, that take
into account highly-changeable nature of some of those characteristics.

One such heuristic might involve more fine-grained control over poll/epoll
notifications about new data availability in ring buffer. Together with
BPF_RB_NO_WAKEUP/BPF_RB_FORCE_WAKEUP flags for output/commit/discard helpers,
it allows BPF program a high degree of control and, e.g., more efficient
batched notifications. Default self-balancing strategy, though, should be
adequate for most applications and will work reliable and efficiently already.

Design and implementation
-------------------------
This reserve/commit schema allows a natural way for multiple producers, either
on different CPUs or even on the same CPU/in the same BPF program, to reserve
independent records and work with them without blocking other producers. This
means that if BPF program was interruped by another BPF program sharing the
same ring buffer, they will both get a record reserved (provided there is
enough space left) and can work with it and submit it independently. This
applies to NMI context as well, except that due to using a spinlock during
reservation, in NMI context, bpf_ringbuf_reserve() might fail to get a lock,
in which case reservation will fail even if ring buffer is not full.

The ring buffer itself internally is implemented as a power-of-2 sized
circular buffer, with two logical and ever-increasing counters (which might
wrap around on 32-bit architectures, that's not a problem):
  - consumer counter shows up to which logical position consumer consumed the
    data;
  - producer counter denotes amount of data reserved by all producers.

Each time a record is reserved, producer that "owns" the record will
successfully advance producer counter. At that point, data is still not yet
ready to be consumed, though. Each record has 8 byte header, which contains
the length of reserved record, as well as two extra bits: busy bit to denote
that record is still being worked on, and discard bit, which might be set at
commit time if record is discarded. In the latter case, consumer is supposed
to skip the record and move on to the next one. Record header also encodes
record's relative offset from the beginning of ring buffer data area (in
pages). This allows bpf_ringbuf_commit()/bpf_ringbuf_discard() to accept only
the pointer to the record itself, without requiring also the pointer to ring
buffer itself. Ring buffer memory location will be restored from record
metadata header. This significantly simplifies verifier, as well as improving
API usability.

Producer counter increments are serialized under spinlock, so there is
a strict ordering between reservations. Commits, on the other hand, are
completely lockless and independent. All records become available to consumer
in the order of reservations, but only after all previous records where
already committed. It is thus possible for slow producers to temporarily hold
off submitted records, that were reserved later.

Reservation/commit/consumer protocol is verified by litmus tests in
Documentation/litmus-test/bpf-rb.

One interesting implementation bit, that significantly simplifies (and thus
speeds up as well) implementation of both producers and consumers is how data
area is mapped twice contiguously back-to-back in the virtual memory. This
allows to not take any special measures for samples that have to wrap around
at the end of the circular buffer data area, because the next page after the
last data page would be first data page again, and thus the sample will still
appear completely contiguous in virtual memory. See comment and a simple ASCII
diagram showing this visually in bpf_ringbuf_area_alloc().

Another feature that distinguishes BPF ringbuf from perf ring buffer is
a self-pacing notifications of new data being availability.
bpf_ringbuf_commit() implementation will send a notification of new record
being available after commit only if consumer has already caught up right up
to the record being committed. If not, consumer still has to catch up and thus
will see new data anyways without needing an extra poll notification.
Benchmarks (see tools/testing/selftests/bpf/benchs/bench_ringbuf.c) show that
this allows to achieve a very high throughput without having to resort to
tricks like "notify only every Nth sample", which are necessary with perf
buffer. For extreme cases, when BPF program wants more manual control of
notifications, commit/discard/output helpers accept BPF_RB_NO_WAKEUP and
BPF_RB_FORCE_WAKEUP flags, which give full control over notifications of data
availability, but require extra caution and diligence in using this API.

Comparison to alternatives
--------------------------
Before considering implementing BPF ring buffer from scratch existing
alternatives in kernel were evaluated, but didn't seem to meet the needs. They
largely fell into few categores:
  - per-CPU buffers (perf, ftrace, etc), which don't satisfy two motivations
    outlined above (ordering and memory consumption);
  - linked list-based implementations; while some were multi-producer designs,
    consuming these from user-space would be very complicated and most
    probably not performant; memory-mapping contiguous piece of memory is
    simpler and more performant for user-space consumers;
  - io_uring is SPSC, but also requires fixed-sized elements. Naively turning
    SPSC queue into MPSC w/ lock would have subpar performance compared to
    locked reserve + lockless commit, as with BPF ring buffer. Fixed sized
    elements would be too limiting for BPF programs, given existing BPF
    programs heavily rely on variable-sized perf buffer already;
  - specialized implementations (like a new printk ring buffer, [0]) with lots
    of printk-specific limitations and implications, that didn't seem to fit
    well for intended use with BPF programs.

  [0] https://lwn.net/Articles/779550/

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200529075424.3139988-2-andriin@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2020-06-01 14:38:22 -07:00
John Fastabend f470378c75 bpf: Extend bpf_base_func_proto helpers with probe_* and *current_task*
Often it is useful when applying policy to know something about the
task. If the administrator has CAP_SYS_ADMIN rights then they can
use kprobe + networking hook and link the two programs together to
accomplish this. However, this is a bit clunky and also means we have
to call both the network program and kprobe program when we could just
use a single program and avoid passing metadata through sk_msg/skb->cb,
socket, maps, etc.

To accomplish this add probe_* helpers to bpf_base_func_proto programs
guarded by a perfmon_capable() check. New supported helpers are the
following,

 BPF_FUNC_get_current_task
 BPF_FUNC_probe_read_user
 BPF_FUNC_probe_read_kernel
 BPF_FUNC_probe_read_user_str
 BPF_FUNC_probe_read_kernel_str

Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/159033905529.12355.4368381069655254932.stgit@john-Precision-5820-Tower
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2020-06-01 14:38:20 -07:00
Linus Torvalds a7092c8204 Kernel side changes:
- Add AMD Fam17h RAPL support
   - Introduce CAP_PERFMON to kernel and user space
   - Add Zhaoxin CPU support
   - Misc fixes and cleanups
 
 Tooling changes:
 
   perf record:
 
     - Introduce --switch-output-event to use arbitrary events to be setup
       and read from a side band thread and, when they take place a signal
       be sent to the main 'perf record' thread, reusing the --switch-output
       code to take perf.data snapshots from the --overwrite ring buffer, e.g.:
 
 	# perf record --overwrite -e sched:* \
 		      --switch-output-event syscalls:*connect* \
 		      workload
 
       will take perf.data.YYYYMMDDHHMMSS snapshots up to around the
       connect syscalls.
 
     - Add --num-synthesize-threads option to control degree of parallelism of the
       synthesize_mmap() code which is scanning /proc/PID/task/PID/maps and can be
       time consuming. This mimics pre-existing behaviour in 'perf top'.
 
   perf bench:
 
     - Add a multi-threaded synthesize benchmark.
     - Add kallsyms parsing benchmark.
 
   Intel PT support:
 
     - Stitch LBR records from multiple samples to get deeper backtraces,
       there are caveats, see the csets for details.
     - Allow using Intel PT to synthesize callchains for regular events.
     - Add support for synthesizing branch stacks for regular events (cycles,
       instructions, etc) from Intel PT data.
 
   Misc changes:
 
     - Updated perf vendor events for power9 and Coresight.
     - Add flamegraph.py script via 'perf flamegraph'
     - Misc other changes, fixes and cleanups - see the Git log for details.
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'perf-core-2020-06-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull perf updates from Ingo Molnar:
 "Kernel side changes:

   - Add AMD Fam17h RAPL support

   - Introduce CAP_PERFMON to kernel and user space

   - Add Zhaoxin CPU support

   - Misc fixes and cleanups

  Tooling changes:

   - perf record:

     Introduce '--switch-output-event' to use arbitrary events to be
     setup and read from a side band thread and, when they take place a
     signal be sent to the main 'perf record' thread, reusing the core
     for '--switch-output' to take perf.data snapshots from the ring
     buffer used for '--overwrite', e.g.:

	# perf record --overwrite -e sched:* \
		      --switch-output-event syscalls:*connect* \
		      workload

     will take perf.data.YYYYMMDDHHMMSS snapshots up to around the
     connect syscalls.

     Add '--num-synthesize-threads' option to control degree of
     parallelism of the synthesize_mmap() code which is scanning
     /proc/PID/task/PID/maps and can be time consuming. This mimics
     pre-existing behaviour in 'perf top'.

   - perf bench:

     Add a multi-threaded synthesize benchmark and kallsyms parsing
     benchmark.

   - Intel PT support:

     Stitch LBR records from multiple samples to get deeper backtraces,
     there are caveats, see the csets for details.

     Allow using Intel PT to synthesize callchains for regular events.

     Add support for synthesizing branch stacks for regular events
     (cycles, instructions, etc) from Intel PT data.

  Misc changes:

   - Updated perf vendor events for power9 and Coresight.

   - Add flamegraph.py script via 'perf flamegraph'

   - Misc other changes, fixes and cleanups - see the Git log for details

  Also, since over the last couple of years perf tooling has matured and
  decoupled from the kernel perf changes to a large degree, going
  forward Arnaldo is going to send perf tooling changes via direct pull
  requests"

* tag 'perf-core-2020-06-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (163 commits)
  perf/x86/rapl: Add AMD Fam17h RAPL support
  perf/x86/rapl: Make perf_probe_msr() more robust and flexible
  perf/x86/rapl: Flip logic on default events visibility
  perf/x86/rapl: Refactor to share the RAPL code between Intel and AMD CPUs
  perf/x86/rapl: Move RAPL support to common x86 code
  perf/core: Replace zero-length array with flexible-array
  perf/x86: Replace zero-length array with flexible-array
  perf/x86/intel: Add more available bits for OFFCORE_RESPONSE of Intel Tremont
  perf/x86/rapl: Add Ice Lake RAPL support
  perf flamegraph: Use /bin/bash for report and record scripts
  perf cs-etm: Move definition of 'traceid_list' global variable from header file
  libsymbols kallsyms: Move hex2u64 out of header
  libsymbols kallsyms: Parse using io api
  perf bench: Add kallsyms parsing
  perf: cs-etm: Update to build with latest opencsd version.
  perf symbol: Fix kernel symbol address display
  perf inject: Rename perf_evsel__*() operating on 'struct evsel *' to evsel__*()
  perf annotate: Rename perf_evsel__*() operating on 'struct evsel *' to evsel__*()
  perf trace: Rename perf_evsel__*() operating on 'struct evsel *' to evsel__*()
  perf script: Rename perf_evsel__*() operating on 'struct evsel *' to evsel__*()
  ...
2020-06-01 13:23:59 -07:00
Linus Torvalds 2227e5b21a The RCU updates for this cycle were:
- RCU-tasks update, including addition of RCU Tasks Trace for
    BPF use and TASKS_RUDE_RCU
  - kfree_rcu() updates.
  - Remove scheduler locking restriction
  - RCU CPU stall warning updates.
  - Torture-test updates.
  - Miscellaneous fixes and other updates.
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'core-rcu-2020-06-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull RCU updates from Ingo Molnar:
 "The RCU updates for this cycle were:

   - RCU-tasks update, including addition of RCU Tasks Trace for BPF use
     and TASKS_RUDE_RCU

   - kfree_rcu() updates.

   - Remove scheduler locking restriction

   - RCU CPU stall warning updates.

   - Torture-test updates.

   - Miscellaneous fixes and other updates"

* tag 'core-rcu-2020-06-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (103 commits)
  rcu: Allow for smp_call_function() running callbacks from idle
  rcu: Provide rcu_irq_exit_check_preempt()
  rcu: Abstract out rcu_irq_enter_check_tick() from rcu_nmi_enter()
  rcu: Provide __rcu_is_watching()
  rcu: Provide rcu_irq_exit_preempt()
  rcu: Make RCU IRQ enter/exit functions rely on in_nmi()
  rcu/tree: Mark the idle relevant functions noinstr
  x86: Replace ist_enter() with nmi_enter()
  x86/mce: Send #MC singal from task work
  x86/entry: Get rid of ist_begin/end_non_atomic()
  sched,rcu,tracing: Avoid tracing before in_nmi() is correct
  sh/ftrace: Move arch_ftrace_nmi_{enter,exit} into nmi exception
  lockdep: Always inline lockdep_{off,on}()
  hardirq/nmi: Allow nested nmi_enter()
  arm64: Prepare arch_nmi_enter() for recursion
  printk: Disallow instrumenting print_nmi_enter()
  printk: Prepare for nested printk_nmi_enter()
  rcutorture: Convert ULONG_CMP_LT() to time_before()
  torture: Add a --kasan argument
  torture: Save a few lines by using config_override_param initially
  ...
2020-06-01 12:56:29 -07:00
Steven Rostedt (VMware) c200784a08 tracing: Add a trace print when traceoff_on_warning is triggered
When "traceoff_on_warning" is enabled and a warning happens, there can still
be many trace events happening on other CPUs between the time the warning
occurred and the last trace event on that same CPU. This can cause confusion
in examining the trace, as it may not be obvious where the warning happened.
By adding a trace print into the trace just before disabling tracing, it
makes it obvious where the warning occurred, and the developer doesn't have
to look at other means to see what CPU it occurred on.

Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-06-01 08:23:47 -04:00
Tom Zanussi 726721a518 tracing: Move synthetic events to a separate file
With the addition of the in-kernel synthetic event API, synthetic
events are no longer specifically tied to the histogram triggers.

The synthetic event code is also making trace_event_hist.c very
bloated, so for those reasons, move it to a separate file,
trace_events_synth.c, along with a new trace_synth.h header file.

Because synthetic events are now independent from hist triggers, add a
new CONFIG_SYNTH_EVENTS config option, and have CONFIG_HIST_TRIGGERS
select it, and have CONFIG_SYNTH_EVENT_GEN_TEST depend on it.

Link: http://lkml.kernel.org/r/4d1fa1f85ed5982706ac44844ac92451dcb04715.1590693308.git.zanussi@kernel.org

Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-06-01 08:23:22 -04:00
Tom Zanussi 2d19bd79ae tracing: Add hist_debug trace event files for histogram debugging
Add a new "hist_debug" file for each trace event, which when read will
dump out a bunch of internal details about the hist triggers defined
on that event.

This is normally off but can be enabled by saying 'y' to the new
CONFIG_HIST_TRIGGERS_DEBUG config option.

This is in support of the new Documentation file describing histogram
internals, Documentation/trace/histogram-design.rst, which was
requested by developers trying to understand the internals when
extending or making use of the hist triggers for higher-level tools.

The histogram-design.rst documentation refers to the hist_debug files
and demonstrates their use with output in the test examples.

Link: http://lkml.kernel.org/r/77914c22b0ba493d9783c53bbfbc6087d6a7e1b1.1585941485.git.zanussi@kernel.org

Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-06-01 08:22:30 -04:00
Tom Zanussi 1b94b3aed3 tracing: Check state.disabled in synth event trace functions
Since trace_state.disabled is set in __synth_event_trace_start() at
the same time -ENOENT is returned, don't bother returning -ENOENT -
just have callers check trace_state.disabled instead, and avoid the
extra return val munging.

Link: http://lkml.kernel.org/r/87315c3889af870e8370e82b76cf48b426d70130.1585941485.git.zanussi@kernel.org

Suggested-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@godmis.org>
2020-06-01 08:21:08 -04:00
Ingo Molnar 0bffedbce9 Linux 5.7-rc7
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Merge tag 'v5.7-rc7' into perf/core, to pick up fixes

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-05-28 07:58:12 +02:00
Christoph Hellwig b8d9e7f241 fs: make the pipe_buf_operations ->confirm operation optional
Just return 0 for success if it is not present.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-05-20 12:11:26 -04:00
Christoph Hellwig 76887c2567 fs: make the pipe_buf_operations ->steal operation optional
Just return 1 for failure if it is not present.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-05-20 12:11:26 -04:00
Christoph Hellwig 6797d97ab9 trace: remove tracing_pipe_buf_ops
tracing_pipe_buf_ops has identical ops to default_pipe_buf_ops, so use
that instead.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-05-20 12:11:26 -04:00
Julia Lawall fc9d276f22 tracing/probe: reverse arguments to list_add
Elsewhere in the file, the function trace_kprobe_has_same_kprobe uses
a trace_probe_event.probes object as the second argument of
list_for_each_entry, ie as a list head, while the list_for_each_entry
iterates over the list fields of the trace_probe structures, making
them the list elements.  So, exchange the arguments on the list_add
call to put the list head in the second argument.

Since both list_head structures were just initialized, this problem
did not cause any loss of information.

Link: https://lkml.kernel.org/r/1588879808-24488-1-git-send-email-Julia.Lawall@inria.fr

Fixes: 60d53e2c3b ("tracing/probe: Split trace_event related data from trace_probe")
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-05-19 21:10:50 -04:00