Commit Graph

35686 Commits

Author SHA1 Message Date
Tom Rix f2a99ddfd0 tracing: Remove definition of DEBUG in trace_mmiotrace.c
Defining DEBUG should only be done in development.
So remove DEBUG.

Link: https://lkml.kernel.org/r/20210115153348.131791-1-trix@redhat.com

Signed-off-by: Tom Rix <trix@redhat.com>
Reviewed-by: Karol Herbst <kherbst@redhat.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-02-02 17:02:07 -05:00
Bean Huo 557d50e79d tracing: Fix a kernel doc warning
Add description for trace_array_put() parameter.

kernel/trace/trace.c:464: warning: Function parameter or member 'this_tr' not described in 'trace_array_put'

Link: https://lkml.kernel.org/r/20210112111202.23508-1-huobean@gmail.com

Signed-off-by: Bean Huo <beanhuo@micron.com>
[ Merged as one of the original fixes was already fixed by someone else ]
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-02-02 17:02:07 -05:00
Bhaskar Chowdhury 39bcdd6a96 tracing: Fix spelling of controlling in uprobes
s/controling/controlling/p

Link: https://lkml.kernel.org/r/20210112045008.29834-1-unixbhaskar@gmail.com

Signed-off-by: Bhaskar Chowdhury <unixbhaskar@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-02-02 17:02:07 -05:00
Colin Ian King 28cc65a173 tracing: Fix spelling mistake in Kconfig "infinit" -> "infinite"
There is a spelling mistake in the Kconfig help text. Fix it.

Link: https://lkml.kernel.org/r/20201216114051.12056-1-colin.king@canonical.com

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-02-02 17:02:07 -05:00
Sebastian Andrzej Siewior fe427886bf tracing: Use in_serving_softirq() to deduct softirq status.
PREEMPT_RT does not report "serving softirq" because the tracing core
looks at the preemption counter while PREEMPT_RT does not update it
while processing softirqs in order to remain preemptible. The
information is stored somewhere else.
The in_serving_softirq() macro and the SOFTIRQ_OFFSET define are still
working but not on the preempt-counter.

Use in_serving_softirq() macro which works on PREEMPT_RT. On !PREEMPT_RT
the compiler (gcc-10 / clang-11) is smart enough to optimize the
in_serving_softirq() related read of the preemption counter away.
The only difference I noticed by using in_serving_softirq() on
!PREEMPT_RT is that gcc-10 implemented tracing_gen_ctx_flags() as
reading FLAG, jmp _tracing_gen_ctx_flags(). Without in_serving_softirq()
it inlined _tracing_gen_ctx_flags() into tracing_gen_ctx_flags().

Link: https://lkml.kernel.org/r/20210125194511.3924915-4-bigeasy@linutronix.de

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-02-02 17:02:06 -05:00
Sebastian Andrzej Siewior 0c02006e6f tracing: Inline tracing_gen_ctx_flags()
Inline tracing_gen_ctx_flags(). This allows to have one ifdef
CONFIG_TRACE_IRQFLAGS_SUPPORT.

This requires to move `trace_flag_type' so tracing_gen_ctx_flags() can
use it.

Link: https://lkml.kernel.org/r/20210125194511.3924915-3-bigeasy@linutronix.de

Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Link: https://lkml.kernel.org/r/20210125140323.6b1ff20c@gandalf.local.home
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-02-02 17:02:06 -05:00
Sebastian Andrzej Siewior 36590c50b2 tracing: Merge irqflags + preempt counter.
The state of the interrupts (irqflags) and the preemption counter are
both passed down to tracing_generic_entry_update(). Only one bit of
irqflags is actually required: The on/off state. The complete 32bit
of the preemption counter isn't needed. Just whether of the upper bits
(softirq, hardirq and NMI) are set and the preemption depth is needed.

The irqflags and the preemption counter could be evaluated early and the
information stored in an integer `trace_ctx'.
tracing_generic_entry_update() would use the upper bits as the
TRACE_FLAG_* and the lower 8bit as the disabled-preemption depth
(considering that one must be substracted from the counter in one
special cases).

The actual preemption value is not used except for the tracing record.
The `irqflags' variable is mostly used only for the tracing record. An
exception here is for instance wakeup_tracer_call() or
probe_wakeup_sched_switch() which explicilty disable interrupts and use
that `irqflags' to save (and restore) the IRQ state and to record the
state.

Struct trace_event_buffer has also the `pc' and flags' members which can
be replaced with `trace_ctx' since their actual value is not used
outside of trace recording.

This will reduce tracing_generic_entry_update() to simply assign values
to struct trace_entry. The evaluation of the TRACE_FLAG_* bits is moved
to _tracing_gen_ctx_flags() which replaces preempt_count() and
local_save_flags() invocations.

As an example, ftrace_syscall_enter() may invoke:
- trace_buffer_lock_reserve() -> … -> tracing_generic_entry_update()
- event_trigger_unlock_commit()
  -> ftrace_trace_stack() -> … -> tracing_generic_entry_update()
  -> ftrace_trace_userstack() -> … -> tracing_generic_entry_update()

In this case the TRACE_FLAG_* bits were evaluated three times. By using
the `trace_ctx' they are evaluated once and assigned three times.

A build with all tracers enabled on x86-64 with and without the patch:

    text     data      bss      dec      hex    filename
21970669 17084168  7639260 46694097  2c87ed1 vmlinux.old
21970293 17084168  7639260 46693721  2c87d59 vmlinux.new

text shrank by 379 bytes, data remained constant.

Link: https://lkml.kernel.org/r/20210125194511.3924915-2-bigeasy@linutronix.de

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-02-02 17:02:06 -05:00
Qiujun Huang c6358bacdc ring-buffer: Drop unneeded check in ring_buffer_resize()
Remove the cpumask check, as we has done it at the beginning of
the function.
Also fix a typo. s/also the on the/also on the/

Link: https://lkml.kernel.org/r/20201224144634.3210-1-hqjagain@gmail.com

Signed-off-by: Qiujun Huang <hqjagain@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-02-02 17:02:06 -05:00
Qiujun Huang 6689bed36c ring-buffer: Remove cpu_buffer argument from the rb_inc_page()
The cpu_buffer argument is not used inside the rb_inc_page() after
commit 3adc54fa82 ("ring-buffer: make the buffer a true circular link
list").
And cpu_buffer argument is not used inside the two functions too,
rb_is_head_page/rb_set_list_to_head.

Link: https://lkml.kernel.org/r/20201225140356.23008-1-hqjagain@gmail.com

Signed-off-by: Qiujun Huang <hqjagain@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-02-02 17:02:06 -05:00
Qiujun Huang 18d14ebdbd tracing: Remove get/put_cpu() from function_trace_init
Since commit b6f11df26f ("trace: Call tracing_reset_online_cpus before
tracer->init()"), get/put_cpu() are not needed anymore.
We can use raw_smp_processor_id() instead.

Link: https://lkml.kernel.org/r/20201230140521.31920-1-hqjagain@gmail.com

Signed-off-by: Qiujun Huang <hqjagain@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-02-02 17:02:05 -05:00
Qiujun Huang b3ca59f6fe tracing: Update trace_ignore_this_task() kernel-doc comment
Update kernel-doc parameter after
commit b3b1e6eded ("ftrace: Create set_ftrace_notrace_pid to not trace tasks")
added @filtered_no_pids.

Link: https://lkml.kernel.org/r/20201231153558.4804-1-hqjagain@gmail.com

Signed-off-by: Qiujun Huang <hqjagain@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-02-02 17:02:05 -05:00
Linus Torvalds 7d36ccd4bd dma-mapping fix for 5.11
- fix a kernel crash in the new dma-mapping benchmark test (Barry Song)
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Merge tag 'dma-mapping-5.11-1' of git://git.infradead.org/users/hch/dma-mapping

Pull dma-mapping fix from Christoph Hellwig:
 "Fix a kernel crash in the new dma-mapping benchmark test (Barry Song)"

* tag 'dma-mapping-5.11-1' of git://git.infradead.org/users/hch/dma-mapping:
  dma-mapping: benchmark: fix kernel crash when dma_map_single fails
2021-02-02 10:40:20 -08:00
Linus Torvalds a992562872 Networking fixes for 5.11-rc7, including fixes from bpf and mac80211
trees.
 
 Current release - regressions:
 
  - ip_tunnel: fix mtu calculation
 
  - mlx5: fix function calculation for page trees
 
 Previous releases - regressions:
 
  - vsock: fix the race conditions in multi-transport support
 
  - neighbour: prevent a dead entry from updating gc_list
 
  - dsa: mv88e6xxx: override existent unicast portvec in port_fdb_add
 
 Previous releases - always broken:
 
  - bpf, cgroup: two copy_{from,to}_user() warn_on_once splats for BPF
                 cgroup getsockopt infra when user space is trying
 		to race against optlen, from Loris Reiff.
 
  - bpf: add missing fput() in BPF inode storage map update helper
 
  - udp: ipv4: manipulate network header of NATed UDP GRO fraglist
 
  - mac80211: fix station rate table updates on assoc
 
  - r8169: work around RTL8125 UDP HW bug
 
  - igc: report speed and duplex as unknown when device is runtime
         suspended
 
  - rxrpc: fix deadlock around release of dst cached on udp tunnel
 
 Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Merge tag 'net-5.11-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

Pull networking fixes from Jakub Kicinski:
 "Networking fixes for 5.11-rc7, including fixes from bpf and mac80211
  trees.

  Current release - regressions:

   - ip_tunnel: fix mtu calculation

   - mlx5: fix function calculation for page trees

  Previous releases - regressions:

   - vsock: fix the race conditions in multi-transport support

   - neighbour: prevent a dead entry from updating gc_list

   - dsa: mv88e6xxx: override existent unicast portvec in port_fdb_add

  Previous releases - always broken:

   - bpf, cgroup: two copy_{from,to}_user() warn_on_once splats for BPF
     cgroup getsockopt infra when user space is trying to race against
     optlen, from Loris Reiff.

   - bpf: add missing fput() in BPF inode storage map update helper

   - udp: ipv4: manipulate network header of NATed UDP GRO fraglist

   - mac80211: fix station rate table updates on assoc

   - r8169: work around RTL8125 UDP HW bug

   - igc: report speed and duplex as unknown when device is runtime
     suspended

   - rxrpc: fix deadlock around release of dst cached on udp tunnel"

* tag 'net-5.11-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (36 commits)
  net: hsr: align sup_multicast_addr in struct hsr_priv to u16 boundary
  net: ipa: fix two format specifier errors
  net: ipa: use the right accessor in ipa_endpoint_status_skip()
  net: ipa: be explicit about endianness
  net: ipa: add a missing __iomem attribute
  net: ipa: pass correct dma_handle to dma_free_coherent()
  r8169: fix WoL on shutdown if CONFIG_DEBUG_SHIRQ is set
  net/rds: restrict iovecs length for RDS_CMSG_RDMA_ARGS
  net: mvpp2: TCAM entry enable should be written after SRAM data
  net: lapb: Copy the skb before sending a packet
  net/mlx5e: Release skb in case of failure in tc update skb
  net/mlx5e: Update max_opened_tc also when channels are closed
  net/mlx5: Fix leak upon failure of rule creation
  net/mlx5: Fix function calculation for page trees
  docs: networking: swap words in icmp_errors_use_inbound_ifaddr doc
  udp: ipv4: manipulate network header of NATed UDP GRO fraglist
  net: ip_tunnel: fix mtu calculation
  vsock: fix the race conditions in multi-transport support
  net: sched: replaced invalid qdisc tree flush helper in qdisc_replace
  ibmvnic: device remove has higher precedence over reset
  ...
2021-02-02 10:26:09 -08:00
Kan Liang 2a6c6b7d7a perf/core: Add PERF_SAMPLE_WEIGHT_STRUCT
Current PERF_SAMPLE_WEIGHT sample type is very useful to expresses the
cost of an action represented by the sample. This allows the profiler
to scale the samples to be more informative to the programmer. It could
also help to locate a hotspot, e.g., when profiling by memory latencies,
the expensive load appear higher up in the histograms. But current
PERF_SAMPLE_WEIGHT sample type is solely determined by one factor. This
could be a problem, if users want two or more factors to contribute to
the weight. For example, Golden Cove core PMU can provide both the
instruction latency and the cache Latency information as factors for the
memory profiling.

For current X86 platforms, although meminfo::latency is defined as a
u64, only the lower 32 bits include the valid data in practice (No
memory access could last than 4G cycles). The higher 32 bits can be used
to store new factors.

Add a new sample type, PERF_SAMPLE_WEIGHT_STRUCT, to indicate the new
sample weight structure. It shares the same space as the
PERF_SAMPLE_WEIGHT sample type.

Users can apply either the PERF_SAMPLE_WEIGHT sample type or the
PERF_SAMPLE_WEIGHT_STRUCT sample type to retrieve the sample weight, but
they cannot apply both sample types simultaneously.

Currently, only X86 and PowerPC use the PERF_SAMPLE_WEIGHT sample type.
- For PowerPC, there is nothing changed for the PERF_SAMPLE_WEIGHT
  sample type. There is no effect for the new PERF_SAMPLE_WEIGHT_STRUCT
  sample type. PowerPC can re-struct the weight field similarly later.
- For X86, the same value will be dumped for the PERF_SAMPLE_WEIGHT
  sample type or the PERF_SAMPLE_WEIGHT_STRUCT sample type for now.
  The following patches will apply the new factors for the
  PERF_SAMPLE_WEIGHT_STRUCT sample type.

The field in the union perf_sample_weight should be shared among
different architectures. A generic name is required, but it's hard to
abstract a name that applies to all architectures. For example, on X86,
the fields are to store all kinds of latency. While on PowerPC, it
stores MMCRA[TECX/TECM], which should not be latency. So a general name
prefix 'var$NUM' is used here.

Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/1611873611-156687-2-git-send-email-kan.liang@linux.intel.com
2021-02-01 15:31:36 +01:00
Linus Torvalds f7ea44c717 A single fix for the single step reporting regression caused by getting the
condition wrong when moving SYSCALL_EMU away from TIF flags.
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Merge tag 'core-urgent-2021-01-31' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull single stepping fix from Thomas Gleixner:
 "A single fix for the single step reporting regression caused by
  getting the condition wrong when moving SYSCALL_EMU away from TIF
  flags"

[ There's apparently another problem too, fix pending ]

* tag 'core-urgent-2021-01-31' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  entry: Unbreak single step reporting behaviour
2021-01-31 11:39:32 -08:00
Marc Zyngier 4c457e8cb7 genirq/msi: Activate Multi-MSI early when MSI_FLAG_ACTIVATE_EARLY is set
When MSI_FLAG_ACTIVATE_EARLY is set (which is the case for PCI),
__msi_domain_alloc_irqs() performs the activation of the interrupt (which
in the case of PCI results in the endpoint being programmed) as soon as the
interrupt is allocated.

But it appears that this is only done for the first vector, introducing an
inconsistent behaviour for PCI Multi-MSI.

Fix it by iterating over the number of vectors allocated to each MSI
descriptor. This is easily achieved by introducing a new
"for_each_msi_vector" iterator, together with a tiny bit of refactoring.

Fixes: f3b0946d62 ("genirq/msi: Make sure PCI MSIs are activated early")
Reported-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20210123122759.1781359-1-maz@kernel.org
2021-01-30 01:22:31 +01:00
Wang ShaoBo 0188b87899 kretprobe: Avoid re-registration of the same kretprobe earlier
Our system encountered a re-init error when re-registering same kretprobe,
where the kretprobe_instance in rp->free_instances is illegally accessed
after re-init.

Implementation to avoid re-registration has been introduced for kprobe
before, but lags for register_kretprobe(). We must check if kprobe has
been re-registered before re-initializing kretprobe, otherwise it will
destroy the data struct of kretprobe registered, which can lead to memory
leak, system crash, also some unexpected behaviors.

We use check_kprobe_rereg() to check if kprobe has been re-registered
before running register_kretprobe()'s body, for giving a warning message
and terminate registration process.

Link: https://lkml.kernel.org/r/20210128124427.2031088-1-bobo.shaobowang@huawei.com

Cc: stable@vger.kernel.org
Fixes: 1f0ab40976 ("kprobes: Prevent re-registration of the same kprobe")
[ The above commit should have been done for kretprobes too ]
Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Acked-by: Ananth N Mavinakayanahalli <ananth@linux.ibm.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Wang ShaoBo <bobo.shaobowang@huawei.com>
Signed-off-by: Cheng Jian <cj.chengjian@huawei.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-01-29 17:29:16 -05:00
Linus Torvalds 32b0c410cd Power management fixes for 5.11-rc6
- Fix a deadlock caused by attempting to acquire the same mutex
    twice in a row in the "kexec jump" code (Baoquan He).
 
  - Modify the hibernation image saving code to flush the unwritten
    data to the swap storage later so as to avoid failing to write the
    image signature which is possible in some cases (Laurent Badel).
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Merge tag 'pm-5.11-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management fixes from Rafael Wysocki:
 "These fix a deadlock in the 'kexec jump' code and address a possible
  hibernation image creation issue.

  Specifics:

   - Fix a deadlock caused by attempting to acquire the same mutex twice
     in a row in the "kexec jump" code (Baoquan He)

   - Modify the hibernation image saving code to flush the unwritten
     data to the swap storage later so as to avoid failing to write the
     image signature which is possible in some cases (Laurent Badel)"

* tag 'pm-5.11-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  PM: hibernate: flush swap writer after marking
  kernel: kexec: remove the lock operation of system_transition_mutex
2021-01-29 13:30:09 -08:00
Masami Hiramatsu 97c753e62e tracing/kprobe: Fix to support kretprobe events on unloaded modules
Fix kprobe_on_func_entry() returns error code instead of false so that
register_kretprobe() can return an appropriate error code.

append_trace_kprobe() expects the kprobe registration returns -ENOENT
when the target symbol is not found, and it checks whether the target
module is unloaded or not. If the target module doesn't exist, it
defers to probe the target symbol until the module is loaded.

However, since register_kretprobe() returns -EINVAL instead of -ENOENT
in that case, it always fail on putting the kretprobe event on unloaded
modules. e.g.

Kprobe event:
/sys/kernel/debug/tracing # echo p xfs:xfs_end_io >> kprobe_events
[   16.515574] trace_kprobe: This probe might be able to register after target module is loaded. Continue.

Kretprobe event: (p -> r)
/sys/kernel/debug/tracing # echo r xfs:xfs_end_io >> kprobe_events
sh: write error: Invalid argument
/sys/kernel/debug/tracing # cat error_log
[   41.122514] trace_kprobe: error: Failed to register probe event
  Command: r xfs:xfs_end_io
             ^

To fix this bug, change kprobe_on_func_entry() to detect symbol lookup
failure and return -ENOENT in that case. Otherwise it returns -EINVAL
or 0 (succeeded, given address is on the entry).

Link: https://lkml.kernel.org/r/161176187132.1067016.8118042342894378981.stgit@devnote2

Cc: stable@vger.kernel.org
Fixes: 59158ec4ae ("tracing/kprobes: Check the probe on unloaded module correctly")
Reported-by: Jianlin Lv <Jianlin.Lv@arm.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-01-29 15:39:48 -05:00
Viktor Rosendahl da7f84cdf0 tracing: Use pause-on-trace with the latency tracers
Eaerlier, tracing was disabled when reading the trace file. This behavior
was changed with:

commit 06e0a548ba ("tracing: Do not disable tracing when reading the
trace file").

This doesn't seem to work with the latency tracers.

The above mentioned commit dit not only change the behavior but also added
an option to emulate the old behavior. The idea with this patch is to
enable this pause-on-trace option when the latency tracers are used.

Link: https://lkml.kernel.org/r/20210119164344.37500-2-Viktor.Rosendahl@bmw.de

Cc: stable@vger.kernel.org
Fixes: 06e0a548ba ("tracing: Do not disable tracing when reading the trace file")
Signed-off-by: Viktor Rosendahl <Viktor.Rosendahl@bmw.de>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-01-29 15:35:33 -05:00
Steven Rostedt (VMware) 7e0a922046 fgraph: Initialize tracing_graph_pause at task creation
On some archs, the idle task can call into cpu_suspend(). The cpu_suspend()
will disable or pause function graph tracing, as there's some paths in
bringing down the CPU that can have issues with its return address being
modified. The task_struct structure has a "tracing_graph_pause" atomic
counter, that when set to something other than zero, the function graph
tracer will not modify the return address.

The problem is that the tracing_graph_pause counter is initialized when the
function graph tracer is enabled. This can corrupt the counter for the idle
task if it is suspended in these architectures.

   CPU 1				CPU 2
   -----				-----
  do_idle()
    cpu_suspend()
      pause_graph_tracing()
          task_struct->tracing_graph_pause++ (0 -> 1)

				start_graph_tracing()
				  for_each_online_cpu(cpu) {
				    ftrace_graph_init_idle_task(cpu)
				      task-struct->tracing_graph_pause = 0 (1 -> 0)

      unpause_graph_tracing()
          task_struct->tracing_graph_pause-- (0 -> -1)

The above should have gone from 1 to zero, and enabled function graph
tracing again. But instead, it is set to -1, which keeps it disabled.

There's no reason that the field tracing_graph_pause on the task_struct can
not be initialized at boot up.

Cc: stable@vger.kernel.org
Fixes: 380c4b1411 ("tracing/function-graph-tracer: append the tracing_graph_flag")
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=211339
Reported-by: pierre.gondois@arm.com
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-01-29 15:07:32 -05:00
Nikolay Borisov 442187f3c2 locking/rwsem: Remove empty rwsem.h
This is a leftover from 7f26482a87 ("locking/percpu-rwsem: Remove the embedded rwsem")

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lkml.kernel.org/r/20210126101721.976027-1-nborisov@suse.com
2021-01-29 20:02:34 +01:00
Jakub Kicinski 06cc6e5dc6 Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Daniel Borkmann says:

====================
pull-request: bpf 2021-01-29

1) Fix two copy_{from,to}_user() warn_on_once splats for BPF cgroup getsockopt
   infra when user space is trying to race against optlen, from Loris Reiff.

2) Fix a missing fput() in BPF inode storage map update helper, from Pan Bian.

3) Fix a build error on unresolved symbols on disabled networking / keys LSM
   hooks, from Mikko Ylinen.

4) Fix preload BPF prog build when the output directory from make points to a
   relative path, from Quentin Monnet.

* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
  bpf, preload: Fix build when $(O) points to a relative path
  bpf: Drop disabled LSM hooks from the sleepable set
  bpf, inode_storage: Put file handler if no storage was found
  bpf, cgroup: Fix problematic bounds check
  bpf, cgroup: Fix optlen WARN_ON_ONCE toctou
====================

Link: https://lore.kernel.org/r/20210129001556.6648-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-28 21:07:45 -08:00
Viresh Kumar be65de6b03 fs: Remove dcookies support
The dcookies stuff was only used by the kernel's old oprofile code. Now
that oprofile's support is removed from the kernel, there is no need for
dcookies as well. Remove it.

Suggested-by: Christoph Hellwig <hch@infradead.org>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Robert Richter <rric@kernel.org>
Acked-by: William Cohen <wcohen@redhat.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
2021-01-29 10:06:46 +05:30
Tobias Klauser 61ca36c8c4 bpf: Simplify cases in bpf_base_func_proto
!perfmon_capable() is checked before the last switch(func_id) in
bpf_base_func_proto. Thus, the cases BPF_FUNC_trace_printk and
BPF_FUNC_snprintf_btf can be moved to that last switch(func_id) to omit
the inline !perfmon_capable() checks.

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210127174615.3038-1-tklauser@distanz.ch
2021-01-29 02:20:28 +01:00
Jakub Kicinski c358f95205 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
drivers/net/can/dev.c
  b552766c87 ("can: dev: prevent potential information leak in can_fill_info()")
  3e77f70e73 ("can: dev: move driver related infrastructure into separate subdir")
  0a042c6ec9 ("can: dev: move netlink related code into seperate file")

  Code move.

drivers/net/ethernet/mellanox/mlx5/core/en_ethtool.c
  57ac4a31c4 ("net/mlx5e: Correctly handle changing the number of queues when the interface is down")
  214baf2287 ("net/mlx5e: Support HTB offload")

  Adjacent code changes

net/switchdev/switchdev.c
  20776b465c ("net: switchdev: don't set port_obj_info->handled true when -EOPNOTSUPP")
  ffb68fc58e ("net: switchdev: remove the transaction structure from port object notifiers")
  bae33f2b5a ("net: switchdev: remove the transaction structure from port attributes")

  Transaction parameter gets dropped otherwise keep the fix.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-28 17:09:31 -08:00
Yuxuan Shui 41c1a06d1d entry: Unbreak single step reporting behaviour
The move of TIF_SYSCALL_EMU to SYSCALL_WORK_SYSCALL_EMU broke single step
reporting. The original code reported the single step when TIF_SINGLESTEP
was set and TIF_SYSCALL_EMU was not set. The SYSCALL_WORK conversion got
the logic wrong and now the reporting only happens when both bits are set.

Restore the original behaviour.

[ tglx: Massaged changelog and dropped the pointless double negation ]

Fixes: 64eb35f701 ("ptrace: Migrate TIF_SYSCALL_EMU to use SYSCALL_WORK flag")
Signed-off-by: Yuxuan Shui <yshuiv7@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Gabriel Krisman Bertazi <krisman@collabora.com>
Link: https://lore.kernel.org/r/877do3gaq9.fsf@m5Zedd9JOGzJrf0
2021-01-28 13:46:55 +01:00
Alex Shi bf594bf400 locking/rtmutex: Add missing kernel-doc markup
To fix the following issues:
kernel/locking/rtmutex.c:1612: warning: Function parameter or member
'lock' not described in '__rt_mutex_futex_unlock'
kernel/locking/rtmutex.c:1612: warning: Function parameter or member
'wake_q' not described in '__rt_mutex_futex_unlock'
kernel/locking/rtmutex.c:1675: warning: Function parameter or member
'name' not described in '__rt_mutex_init'
kernel/locking/rtmutex.c:1675: warning: Function parameter or member
'key' not described in '__rt_mutex_init'

[ tglx: Change rt lock to rt_mutex for consistency sake ]

Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/1605257895-5536-2-git-send-email-alex.shi@linux.alibaba.com
2021-01-28 13:20:18 +01:00
Jangwoong Kim 0f9438503e futex: Remove unneeded gotos
Get rid of gotos that do not contain any cleanup. These were not removed in
commit 9180bd467f ("futex: Remove put_futex_key()").

Signed-off-by: Jangwoong Kim <6812skiii@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20201230122953.10473-1-6812skiii@gmail.com
2021-01-28 13:20:18 +01:00
Alejandro Colomar 1ce53e2c2a futex: Change utime parameter to be 'const ... *'
futex(2) says that 'utime' is a pointer to 'const'.  The implementation
doesn't use 'const'; however, it _never_ modifies the contents of utime.

- futex() either uses 'utime' as a pointer to struct or as a 'u32'.

- In case it's used as a 'u32', it makes a copy of it, and of course it is
  not dereferenced.

- In case it's used as a 'struct __kernel_timespec __user *', the pointer
  is not dereferenced inside the futex() definition, and it is only passed
  to a function: get_timespec64(), which accepts a 'const struct
  __kernel_timespec __user *'.

[ tglx: Make the same change to the compat syscall and fixup the prototypes. ]

Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20201128123945.4592-1-alx.manpages@gmail.com
2021-01-28 13:20:18 +01:00
Emil Renner Berthing c260954177 genirq: Use new tasklet API for resend_tasklet
This converts the resend_tasklet to use the new API in
commit 12cc923f1c ("tasklet: Introduce new initialization API")

The new API changes the argument passed to the callback function, but
fortunately the argument isn't used so it is straight forward to use
DECLARE_TASKLET() rather than DECLARE_TASKLET_OLD().

Signed-off-by: Emil Renner Berthing <kernel@esmil.dk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210123182456.6521-1-esmil@mailme.dk
2021-01-28 11:18:04 +01:00
Yang Yang 127c8c5f05 audit: Make audit_filter_syscall() return void
No invoker uses the return value of audit_filter_syscall().
So make it return void, and amend the comment of
audit_filter_syscall().

Signed-off-by: Yang Yang <yang.yang29@zte.com.cn>
Reviewed-by: Richard Guy Briggs <rgb@redhat.com>
[PM: removed the changelog from the description]
Signed-off-by: Paul Moore <paul@paul-moore.com>
2021-01-27 21:55:14 -05:00
Stanislav Fomichev 772412176f bpf: Allow rewriting to ports under ip_unprivileged_port_start
At the moment, BPF_CGROUP_INET{4,6}_BIND hooks can rewrite user_port
to the privileged ones (< ip_unprivileged_port_start), but it will
be rejected later on in the __inet_bind or __inet6_bind.

Let's add another return value to indicate that CAP_NET_BIND_SERVICE
check should be ignored. Use the same idea as we currently use
in cgroup/egress where bit #1 indicates CN. Instead, for
cgroup/bind{4,6}, bit #1 indicates that CAP_NET_BIND_SERVICE should
be bypassed.

v5:
- rename flags to be less confusing (Andrey Ignatov)
- rework BPF_PROG_CGROUP_INET_EGRESS_RUN_ARRAY to work on flags
  and accept BPF_RET_SET_CN (no behavioral changes)

v4:
- Add missing IPv6 support (Martin KaFai Lau)

v3:
- Update description (Martin KaFai Lau)
- Fix capability restore in selftest (Martin KaFai Lau)

v2:
- Switch to explicit return code (Martin KaFai Lau)

Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Andrey Ignatov <rdna@fb.com>
Link: https://lore.kernel.org/bpf/20210127193140.3170382-1-sdf@google.com
2021-01-27 18:18:15 -08:00
Menglong Dong 60e578e82b bpf: Change 'BPF_ADD' to 'BPF_AND' in print_bpf_insn()
This 'BPF_ADD' is duplicated, and I belive it should be 'BPF_AND'.

Fixes: 981f94c3e9 ("bpf: Add bitwise atomic instructions")
Signed-off-by: Menglong Dong <dong.menglong@zte.com.cn>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Brendan Jackman <jackmanb@google.com>
Link: https://lore.kernel.org/bpf/20210127022507.23674-1-dong.menglong@zte.com.cn
2021-01-27 22:23:46 +01:00
Zqiang ccf7ce46ab PM: sleep: No need to check PF_WQ_WORKER in thaw_kernel_threads()
Because PF_KTHREAD is set for all wq worker threads, it is
not necessary to check PF_WQ_WORKER in addition to it in
thaw_kernel_threads(), so stop doing that.

Signed-off-by: Zqiang <qiang.zhang@windriver.com>
[ rjw: Subject and changelog rewrite ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2021-01-27 19:20:17 +01:00
Mel Gorman bae4ec1364 sched/fair: Move avg_scan_cost calculations under SIS_PROP
As noted by Vincent Guittot, avg_scan_costs are calculated for SIS_PROP
even if SIS_PROP is disabled. Move the time calculations under a SIS_PROP
check and while we are at it, exclude the cost of initialising the CPU
mask from the average scan cost.

Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://lkml.kernel.org/r/20210125085909.4600-3-mgorman@techsingularity.net
2021-01-27 17:26:44 +01:00
Mel Gorman e6e0dc2d54 sched/fair: Remove SIS_AVG_CPU
SIS_AVG_CPU was introduced as a means of avoiding a search when the
average search cost indicated that the search would likely fail. It was
a blunt instrument and disabled by commit 4c77b18cf8 ("sched/fair: Make
select_idle_cpu() more aggressive") and later replaced with a proportional
search depth by commit 1ad3aaf3fc ("sched/core: Implement new approach
to scale select_idle_cpu()").

While there are corner cases where SIS_AVG_CPU is better, it has now been
disabled for almost three years. As the intent of SIS_PROP is to reduce
the time complexity of select_idle_cpu(), lets drop SIS_AVG_CPU and focus
on SIS_PROP as a throttling mechanism.

Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://lkml.kernel.org/r/20210125085909.4600-2-mgorman@techsingularity.net
2021-01-27 17:26:43 +01:00
Valentin Schneider 620a6dc407 sched/topology: Make sched_init_numa() use a set for the deduplicating sort
The deduplicating sort in sched_init_numa() assumes that the first line in
the distance table contains all unique values in the entire table. I've
been trying to pen what this exactly means for the topology, but it's not
straightforward. For instance, topology.c uses this example:

  node   0   1   2   3
    0:  10  20  20  30
    1:  20  10  20  20
    2:  20  20  10  20
    3:  30  20  20  10

  0 ----- 1
  |     / |
  |   /   |
  | /     |
  2 ----- 3

Which works out just fine. However, if we swap nodes 0 and 1:

  1 ----- 0
  |     / |
  |   /   |
  | /     |
  2 ----- 3

we get this distance table:

  node   0  1  2  3
    0:  10 20 20 20
    1:  20 10 20 30
    2:  20 20 10 20
    3:  20 30 20 10

Which breaks the deduplicating sort (non-representative first line). In
this case this would just be a renumbering exercise, but it so happens that
we can have a deduplicating sort that goes through the whole table in O(n²)
at the extra cost of a temporary memory allocation (i.e. any form of set).

The ACPI spec (SLIT) mentions distances are encoded on 8 bits. Following
this, implement the set as a 256-bits bitmap. Should this not be
satisfactory (i.e. we want to support 32-bit values), then we'll have to go
for some other sparse set implementation.

This has the added benefit of letting us allocate just the right amount of
memory for sched_domains_numa_distance[], rather than an arbitrary
(nr_node_ids + 1).

Note: DT binding equivalent (distance-map) decodes distances as 32-bit
values.

Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20210122123943.1217-2-valentin.schneider@arm.com
2021-01-27 17:26:42 +01:00
Qais Yousef 0ae78eec8a sched/eas: Don't update misfit status if the task is pinned
If the task is pinned to a cpu, setting the misfit status means that
we'll unnecessarily continuously attempt to migrate the task but fail.

This continuous failure will cause the balance_interval to increase to
a high value, and eventually cause unnecessary significant delays in
balancing the system when real imbalance happens.

Caught while testing uclamp where rt-app calibration loop was pinned to
cpu 0, shortly after which we spawn another task with high util_clamp
value. The task was failing to migrate after over 40ms of runtime due to
balance_interval unnecessary expanded to a very high value from the
calibration loop.

Not done here, but it could be useful to extend the check for pinning to
verify that the affinity of the task has a cpu that fits. We could end
up in a similar situation otherwise.

Fixes: 3b1baa6496 ("sched/fair: Add 'group_misfit_task' load-balance type")
Signed-off-by: Qais Yousef <qais.yousef@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Quentin Perret <qperret@google.com>
Acked-by: Valentin Schneider <valentin.schneider@arm.com>
Link: https://lkml.kernel.org/r/20210119120755.2425264-1-qais.yousef@arm.com
2021-01-27 17:26:42 +01:00
Barry Song d17405d52b dma-mapping: benchmark: fix kernel crash when dma_map_single fails
if dma_map_single() fails, kernel will give the below oops since
task_struct has been destroyed and we are running into the memory
corruption due to use-after-free in kthread_stop():

[   48.095310] Unable to handle kernel paging request at virtual address 000000c473548040
[   48.095736] Mem abort info:
[   48.095864]   ESR = 0x96000004
[   48.096025]   EC = 0x25: DABT (current EL), IL = 32 bits
[   48.096268]   SET = 0, FnV = 0
[   48.096401]   EA = 0, S1PTW = 0
[   48.096538] Data abort info:
[   48.096659]   ISV = 0, ISS = 0x00000004
[   48.096820]   CM = 0, WnR = 0
[   48.097079] user pgtable: 4k pages, 48-bit VAs, pgdp=0000000104639000
[   48.098099] [000000c473548040] pgd=0000000000000000, p4d=0000000000000000
[   48.098832] Internal error: Oops: 96000004 [#1] PREEMPT SMP
[   48.099232] Modules linked in:
[   48.099387] CPU: 0 PID: 2 Comm: kthreadd Tainted: G        W
[   48.099887] Hardware name: linux,dummy-virt (DT)
[   48.100078] pstate: 60000005 (nZCv daif -PAN -UAO -TCO BTYPE=--)
[   48.100516] pc : __kmalloc_node+0x214/0x368
[   48.100944] lr : __kmalloc_node+0x1f4/0x368
[   48.101458] sp : ffff800011f0bb80
[   48.101843] x29: ffff800011f0bb80 x28: ffff0000c0098ec0
[   48.102330] x27: 0000000000000000 x26: 00000000001d4600
[   48.102648] x25: ffff0000c0098ec0 x24: ffff800011b6a000
[   48.102988] x23: 00000000ffffffff x22: ffff0000c0098ec0
[   48.103333] x21: ffff8000101d7a54 x20: 0000000000000dc0
[   48.103657] x19: ffff0000c0001e00 x18: 0000000000000000
[   48.104069] x17: 0000000000000000 x16: 0000000000000000
[   48.105449] x15: 000001aa0304e7b9 x14: 00000000000003b1
[   48.106401] x13: ffff8000122d5000 x12: ffff80001228d000
[   48.107296] x11: ffff0000c0154340 x10: 0000000000000000
[   48.107862] x9 : ffff80000fffffff x8 : ffff0000c473527f
[   48.108326] x7 : ffff800011e62f58 x6 : ffff0000c01c8ed8
[   48.108778] x5 : ffff0000c0098ec0 x4 : 0000000000000000
[   48.109223] x3 : 00000000001d4600 x2 : 0000000000000040
[   48.109656] x1 : 0000000000000001 x0 : ff0000c473548000
[   48.110104] Call trace:
[   48.110287]  __kmalloc_node+0x214/0x368
[   48.110493]  __vmalloc_node_range+0xc4/0x298
[   48.110805]  copy_process+0x2c8/0x15c8
[   48.111133]  kernel_clone+0x5c/0x3c0
[   48.111373]  kernel_thread+0x64/0x90
[   48.111604]  kthreadd+0x158/0x368
[   48.111810]  ret_from_fork+0x10/0x30
[   48.112336] Code: 17ffffe9 b9402a62 b94008a1 11000421 (f8626802)
[   48.112884] ---[ end trace d4890e21e75419d5 ]---

Signed-off-by: Barry Song <song.bao.hua@hisilicon.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2021-01-27 17:18:38 +01:00
Stephen Zhang e9ad2eb3d9 workqueue: Use %s instead of function name
It is better to replace the function name with %s, in case the function
name changes.

Signed-off-by: Stephen Zhang <stephenzhangzsd@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2021-01-27 09:42:48 -05:00
Quentin Monnet 150a27328b bpf, preload: Fix build when $(O) points to a relative path
Building the kernel with CONFIG_BPF_PRELOAD, and by providing a relative
path for the output directory, may fail with the following error:

  $ make O=build bindeb-pkg
  ...
  /.../linux/tools/scripts/Makefile.include:5: *** O=build does not exist.  Stop.
  make[7]: *** [/.../linux/kernel/bpf/preload/Makefile:9: kernel/bpf/preload/libbpf.a] Error 2
  make[6]: *** [/.../linux/scripts/Makefile.build:500: kernel/bpf/preload] Error 2
  make[5]: *** [/.../linux/scripts/Makefile.build:500: kernel/bpf] Error 2
  make[4]: *** [/.../linux/Makefile:1799: kernel] Error 2
  make[4]: *** Waiting for unfinished jobs....

In the case above, for the "bindeb-pkg" target, the error is produced by
the "dummy" check in Makefile.include, called from libbpf's Makefile.
This check changes directory to $(PWD) before checking for the existence
of $(O). But at this step we have $(PWD) pointing to "/.../linux/build",
and $(O) pointing to "build". So the Makefile.include tries in fact to
assert the existence of a directory named "/.../linux/build/build",
which does not exist.

Note that the error does not occur for all make targets and
architectures combinations. This was observed on x86 for "bindeb-pkg",
or for a regular build for UML [0].

Here are some details. The root Makefile recursively calls itself once,
after changing directory to $(O). The content for the variable $(PWD) is
preserved across recursive calls to make, so it is unchanged at this
step. For "bindeb-pkg", $(PWD) is eventually updated because the target
writes a new Makefile (as debian/rules) and calls it indirectly through
dpkg-buildpackage. This script does not preserve $(PWD), which is reset
to the current working directory when the target in debian/rules is
called.

Although not investigated, it seems likely that something similar causes
UML to change its value for $(PWD).

Non-trivial fixes could be to remove the use of $(PWD) from the "dummy"
check, or to make sure that $(PWD) and $(O) are preserved or updated to
always play well and form a valid $(PWD)/$(O) path across the different
targets and architectures. Instead, we take a simpler approach and just
update $(O) when calling libbpf's Makefile, so it points to an absolute
path which should always resolve for the "dummy" check run (through
includes) by that Makefile.

David Gow previously posted a slightly different version of this patch
as a RFC [0], two months ago or so.

  [0] https://lore.kernel.org/bpf/20201119085022.3606135-1-davidgow@google.com/t/#u

Fixes: d71fa5c976 ("bpf: Add kernel module with user mode driver that populates bpffs.")
Reported-by: David Gow <davidgow@google.com>
Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Link: https://lore.kernel.org/bpf/20210126161320.24561-1-quentin@isovalent.com
2021-01-26 23:13:25 +01:00
Mikko Ylinen 78031381ae bpf: Drop disabled LSM hooks from the sleepable set
Some networking and keys LSM hooks are conditionally enabled
and when building the new sleepable BPF LSM hooks with those
LSM hooks disabled, the following build error occurs:

  BTFIDS  vmlinux
  FAILED unresolved symbol bpf_lsm_socket_socketpair

To fix the error, conditionally add the relevant networking/keys
LSM hooks to the sleepable set.

Fixes: 423f16108c ("bpf: Augment the set of sleepable LSM hooks")
Signed-off-by: Mikko Ylinen <mikko.ylinen@linux.intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: KP Singh <kpsingh@kernel.org>
Link: https://lore.kernel.org/bpf/20210125063936.89365-1-mikko.ylinen@linux.intel.com
2021-01-26 17:08:50 +01:00
Thomas Gleixner 34b1a1ce14 futex: Handle faults correctly for PI futexes
fixup_pi_state_owner() tries to ensure that the state of the rtmutex,
pi_state and the user space value related to the PI futex are consistent
before returning to user space. In case that the user space value update
faults and the fault cannot be resolved by faulting the page in via
fault_in_user_writeable() the function returns with -EFAULT and leaves
the rtmutex and pi_state owner state inconsistent.

A subsequent futex_unlock_pi() operates on the inconsistent pi_state and
releases the rtmutex despite not owning it which can corrupt the RB tree of
the rtmutex and cause a subsequent kernel stack use after free.

It was suggested to loop forever in fixup_pi_state_owner() if the fault
cannot be resolved, but that results in runaway tasks which is especially
undesired when the problem happens due to a programming error and not due
to malice.

As the user space value cannot be fixed up, the proper solution is to make
the rtmutex and the pi_state consistent so both have the same owner. This
leaves the user space value out of sync. Any subsequent operation on the
futex will fail because the 10th rule of PI futexes (pi_state owner and
user space value are consistent) has been violated.

As a consequence this removes the inept attempts of 'fixing' the situation
in case that the current task owns the rtmutex when returning with an
unresolvable fault by unlocking the rtmutex which left pi_state::owner and
rtmutex::owner out of sync in a different and only slightly less dangerous
way.

Fixes: 1b7558e457 ("futexes: fix fault handling in futex_lock_pi")
Reported-by: gzobqq@gmail.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
2021-01-26 15:11:00 +01:00
Thomas Gleixner f2dac39d93 futex: Simplify fixup_pi_state_owner()
Too many gotos already and an upcoming fix would make it even more
unreadable.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
2021-01-26 15:10:59 +01:00
Thomas Gleixner 6ccc84f917 futex: Use pi_state_update_owner() in put_pi_state()
No point in open coding it. This way it gains the extra sanity checks.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
2021-01-26 15:10:59 +01:00
Thomas Gleixner 2156ac1934 rtmutex: Remove unused argument from rt_mutex_proxy_unlock()
Nothing uses the argument. Remove it as preparation to use
pi_state_update_owner().

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
2021-01-26 15:10:58 +01:00
Thomas Gleixner c5cade200a futex: Provide and use pi_state_update_owner()
Updating pi_state::owner is done at several places with the same
code. Provide a function for it and use that at the obvious places.

This is also a preparation for a bug fix to avoid yet another copy of the
same code or alternatively introducing a completely unpenetratable mess of
gotos.

Originally-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
2021-01-26 15:10:58 +01:00
Thomas Gleixner 04b79c5520 futex: Replace pointless printk in fixup_owner()
If that unexpected case of inconsistent arguments ever happens then the
futex state is left completely inconsistent and the printk is not really
helpful. Replace it with a warning and make the state consistent.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
2021-01-26 15:10:58 +01:00
Thomas Gleixner 12bb3f7f1b futex: Ensure the correct return value from futex_lock_pi()
In case that futex_lock_pi() was aborted by a signal or a timeout and the
task returned without acquiring the rtmutex, but is the designated owner of
the futex due to a concurrent futex_unlock_pi() fixup_owner() is invoked to
establish consistent state. In that case it invokes fixup_pi_state_owner()
which in turn tries to acquire the rtmutex again. If that succeeds then it
does not propagate this success to fixup_owner() and futex_lock_pi()
returns -EINTR or -ETIMEOUT despite having the futex locked.

Return success from fixup_pi_state_owner() in all cases where the current
task owns the rtmutex and therefore the futex and propagate it correctly
through fixup_owner(). Fixup the other callsite which does not expect a
positive return value.

Fixes: c1e2f0eaf0 ("futex: Avoid violating the 10th rule of futex")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
2021-01-26 15:10:58 +01:00
Lukas Bulwahn 8f0bfc25c9 watch_queue: rectify kernel-doc for init_watch()
The command './scripts/kernel-doc -none kernel/watch_queue.c'
reported a mismatch in the kernel-doc of init_watch().

Rectify the kernel-doc, such that no issues remain for watch_queue.c.

Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
2021-01-26 11:16:34 +00:00
Lukas Bulwahn 9bc284ca0b printk: rectify kernel-doc for prb_rec_init_wr()
The command 'find ./kernel/printk/ | xargs ./scripts/kernel-doc -none'
reported a mismatch with the kernel-doc of prb_rec_init_wr().

Rectify the kernel-doc, such that no issues remain for ./kernel/printk/.

Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Reviewed-by: John Ogness <john.ogness@linutronix.de>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20210125081748.19903-1-lukas.bulwahn@gmail.com
2021-01-26 11:17:51 +01:00
Linus Torvalds 007ad27d7b Printk urgent fixup for 5.11-rc6
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Merge tag 'printk-for-5.11-urgent-fixup' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux

Pull printk fix from Petr Mladek:
 "The fix of a potential buffer overflow in 5.11-rc5 introduced another
  one. The trailing '\0' might be written up to the message "len" past
  the buffer. Fortunately, it is not that easy to hit.

  Most readers use 1kB buffers for a single message. Typical messages
  fit into the temporary buffer with enough reserve.

  Also readers do not rely on the '\0'. It is related to the previous
  fix. Some readers required the space for the trailing '\0'. We decided
  to write it there to avoid such regressions in the future.

  The most realistic victims are dumpers using kmsg_dump_get_buffer().
  They are filling the entire buffer with as many messages as possible.
  They are typically used when handling panic()"

* tag 'printk-for-5.11-urgent-fixup' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux:
  printk: fix string termination for record_print_text()
2021-01-25 10:19:40 -08:00
Laurent Badel fef9c8d28e PM: hibernate: flush swap writer after marking
Flush the swap writer after, not before, marking the files, to ensure the
signature is properly written.

Fixes: 6f612af578 ("PM / Hibernate: Group swap ops")
Signed-off-by: Laurent Badel <laurentbadel@eaton.com>
Cc: All applicable <stable@vger.kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2021-01-25 18:52:30 +01:00
Baoquan He 56c91a1843 kernel: kexec: remove the lock operation of system_transition_mutex
Function kernel_kexec() is called with lock system_transition_mutex
held in reboot system call. While inside kernel_kexec(), it will
acquire system_transition_mutex agin. This will lead to dead lock.

The dead lock should be easily triggered, it hasn't caused any
failure report just because the feature 'kexec jump' is almost not
used by anyone as far as I know. An inquiry can be made about who
is using 'kexec jump' and where it's used. Before that, let's simply
remove the lock operation inside CONFIG_KEXEC_JUMP ifdeffery scope.

Fixes: 55f2503c3b ("PM / reboot: Eliminate race between reboot and suspend")
Signed-off-by: Baoquan He <bhe@redhat.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Pingfan Liu <kernelfans@gmail.com>
Cc: 4.19+ <stable@vger.kernel.org> # 4.19+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2021-01-25 18:40:37 +01:00
Petr Mladek 61bb17da44 Merge branch 'printk-rework' into for-linus 2021-01-25 14:29:35 +01:00
John Ogness 08d60e5999 printk: fix string termination for record_print_text()
Commit f0e386ee0c ("printk: fix buffer overflow potential for
print_text()") added string termination in record_print_text().
However it used the wrong base pointer for adding the terminator.
This led to a 0-byte being written somewhere beyond the buffer.

Use the correct base pointer when adding the terminator.

Fixes: f0e386ee0c ("printk: fix buffer overflow potential for print_text()")
Reported-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20210124202728.4718-1-john.ogness@linutronix.de
2021-01-25 10:37:08 +01:00
Christoph Hellwig 309dca309f block: store a block_device pointer in struct bio
Replace the gendisk pointer in struct bio with a pointer to the newly
improved struct block device.  From that the gendisk can be trivially
accessed with an extra indirection, but it also allows to directly
look up all information related to partition remapping.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-01-24 18:17:20 -07:00
Linus Torvalds e68061375f - Fix a kernel panic in mips-cpu due to invalid irq domain hierarchy.
- Fix to not lose IPIs on bcm2836.
 
  - Fix for a bogus marking of ITS devices as shared due to unitialized
    stack variable.
 
  - Clear a phantom interrupt on qcom-pdc to unblock suspend.
 
  - Small cleanups, warning and build fixes.
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Merge tag 'irq_urgent_for_v5.11_rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull irq fixes from Borislav Petkov:

 - Fix a kernel panic in mips-cpu due to invalid irq domain hierarchy.

 - Fix to not lose IPIs on bcm2836.

 - Fix for a bogus marking of ITS devices as shared due to unitialized
   stack variable.

 - Clear a phantom interrupt on qcom-pdc to unblock suspend.

 - Small cleanups, warning and build fixes.

* tag 'irq_urgent_for_v5.11_rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  genirq: Export irq_check_status_bit()
  irqchip/mips-cpu: Set IPI domain parent chip
  irqchip/pruss: Simplify the TI_PRUSS_INTC Kconfig
  irqchip/loongson-liointc: Fix build warnings
  driver core: platform: Add extra error check in devm_platform_get_irqs_affinity()
  irqchip/bcm2836: Fix IPI acknowledgement after conversion to handle_percpu_devid_irq
  irqchip/irq-sl28cpld: Convert comma to semicolon
  genirq/msi: Initialize msi_alloc_info before calling msi_domain_prepare_irqs()
2021-01-24 10:24:20 -08:00
Linus Torvalds 24c56ee06c - Correct the marking of kthreads which are supposed to run on a specific,
single CPU vs such which are affine to only one CPU, mark per-cpu workqueue
  threads as such and make sure that marking "survives" CPU hotplug. Fix CPU
  hotplug issues with such kthreads.
 
  - A fix to not push away tasks on CPUs coming online.
 
  - Have workqueue CPU hotplug code use cpu_possible_mask when breaking affinity
    on CPU offlining so that pending workers can finish on newly arrived onlined
    CPUs too.
 
  - Dump tasks which haven't vacated a CPU which is currently being unplugged.
 
  - Register a special scale invariance callback which gets called on resume
  from RAM to read out APERF/MPERF after resume and thus make the schedutil
  scaling governor more precise.
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Merge tag 'sched_urgent_for_v5.11_rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler fixes from Borislav Petkov:

 - Correct the marking of kthreads which are supposed to run on a
   specific, single CPU vs such which are affine to only one CPU, mark
   per-cpu workqueue threads as such and make sure that marking
   "survives" CPU hotplug. Fix CPU hotplug issues with such kthreads.

 - A fix to not push away tasks on CPUs coming online.

 - Have workqueue CPU hotplug code use cpu_possible_mask when breaking
   affinity on CPU offlining so that pending workers can finish on newly
   arrived onlined CPUs too.

 - Dump tasks which haven't vacated a CPU which is currently being
   unplugged.

 - Register a special scale invariance callback which gets called on
   resume from RAM to read out APERF/MPERF after resume and thus make
   the schedutil scaling governor more precise.

* tag 'sched_urgent_for_v5.11_rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched: Relax the set_cpus_allowed_ptr() semantics
  sched: Fix CPU hotplug / tighten is_per_cpu_kthread()
  sched: Prepare to use balance_push in ttwu()
  workqueue: Restrict affinity change to rescuer
  workqueue: Tag bound workers with KTHREAD_IS_PER_CPU
  kthread: Extract KTHREAD_IS_PER_CPU
  sched: Don't run cpu-online with balance_push() enabled
  workqueue: Use cpu_possible_mask instead of cpu_active_mask to break affinity
  sched/core: Print out straggler tasks in sched_cpu_dying()
  x86: PM: Register syscore_ops for scale invariance
2021-01-24 10:09:20 -08:00
Linus Torvalds 025929f468 - Fix an integer overflow in the NTP RTC synchronization which lead to latter
happening every 2 seconds instead of the intended every 11 minutes.
 
  - Get rid of now unused get_seconds().
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Merge tag 'timers_urgent_for_v5.11_rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull timer fixes from Borislav Petkov:

 - Fix an integer overflow in the NTP RTC synchronization which led to
   the latter happening every 2 seconds instead of the intended every 11
   minutes.

 - Get rid of now unused get_seconds().

* tag 'timers_urgent_for_v5.11_rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  ntp: Fix RTC synchronization on 32-bit platforms
  timekeeping: Remove unused get_seconds()
2021-01-24 09:58:38 -08:00
Linus Torvalds 17b6c49da3 - Add a new Intel model number for Alder Lake
- Differentiate which aspects of the FPU state get saved/restored when the FPU
    is used in-kernel and fix a boot crash on K7 due to early MXCSR access before
    CR4.OSFXSR is even set.
 
  - A couple of noinstr annotation fixes
 
  - Correct die ID setting on AMD for users of topology information which need
    the correct die ID
 
  - A SEV-ES fix to handle string port IO to/from kernel memory properly
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Merge tag 'x86_urgent_for_v5.11_rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 fixes from Borislav Petkov:

 - Add a new Intel model number for Alder Lake

 - Differentiate which aspects of the FPU state get saved/restored when
   the FPU is used in-kernel and fix a boot crash on K7 due to early
   MXCSR access before CR4.OSFXSR is even set.

 - A couple of noinstr annotation fixes

 - Correct die ID setting on AMD for users of topology information which
   need the correct die ID

 - A SEV-ES fix to handle string port IO to/from kernel memory properly

* tag 'x86_urgent_for_v5.11_rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/cpu: Add another Alder Lake CPU to the Intel family
  x86/mmx: Use KFPU_387 for MMX string operations
  x86/fpu: Add kernel_fpu_begin_mask() to selectively initialize state
  x86/topology: Make __max_die_per_package available unconditionally
  x86: __always_inline __{rd,wr}msr()
  x86/mce: Remove explicit/superfluous tracing
  locking/lockdep: Avoid noinstr warning for DEBUG_LOCKDEP
  locking/lockdep: Cure noinstr fail
  x86/sev: Fix nonistr violation
  x86/entry: Fix noinstr fail
  x86/cpu/amd: Set __max_die_per_package on AMD
  x86/sev-es: Handle string port IO to kernel memory properly
2021-01-24 09:46:05 -08:00
Linus Torvalds c509ce2378 for-linus-2021-01-24
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Merge tag 'for-linus-2021-01-24' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux

Pull misc fixes from Christian Brauner:

 - Jann reported sparse complaints because of a missing __user
   annotation in a helper we added way back when we added
   pidfd_send_signal() to avoid compat syscall handling. Fix it.

 - Yanfei replaces a reference in a comment to the _do_fork() helper I
   removed a while ago with a reference to the new kernel_clone()
   replacement

 - Alexander Guril added a simple coding style fix

* tag 'for-linus-2021-01-24' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux:
  kthread: remove comments about old _do_fork() helper
  Kernel: fork.c: Fix coding style: Do not use {} around single-line statements
  signal: Add missing __user annotation to copy_siginfo_from_user_any
2021-01-24 09:35:28 -08:00
Christian Brauner 549c729771
fs: make helpers idmap mount aware
Extend some inode methods with an additional user namespace argument. A
filesystem that is aware of idmapped mounts will receive the user
namespace the mount has been marked with. This can be used for
additional permission checking and also to enable filesystems to
translate between uids and gids if they need to. We have implemented all
relevant helpers in earlier patches.

As requested we simply extend the exisiting inode method instead of
introducing new ones. This is a little more code churn but it's mostly
mechanical and doesnt't leave us with additional inode methods.

Link: https://lore.kernel.org/r/20210121131959.646623-25-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2021-01-24 14:27:20 +01:00
Christian Brauner 71bc356f93
commoncap: handle idmapped mounts
When interacting with user namespace and non-user namespace aware
filesystem capabilities the vfs will perform various security checks to
determine whether or not the filesystem capabilities can be used by the
caller, whether they need to be removed and so on. The main
infrastructure for this resides in the capability codepaths but they are
called through the LSM security infrastructure even though they are not
technically an LSM or optional. This extends the existing security hooks
security_inode_removexattr(), security_inode_killpriv(),
security_inode_getsecurity() to pass down the mount's user namespace and
makes them aware of idmapped mounts.

In order to actually get filesystem capabilities from disk the
capability infrastructure exposes the get_vfs_caps_from_disk() helper.
For user namespace aware filesystem capabilities a root uid is stored
alongside the capabilities.

In order to determine whether the caller can make use of the filesystem
capability or whether it needs to be ignored it is translated according
to the superblock's user namespace. If it can be translated to uid 0
according to that id mapping the caller can use the filesystem
capabilities stored on disk. If we are accessing the inode that holds
the filesystem capabilities through an idmapped mount we map the root
uid according to the mount's user namespace. Afterwards the checks are
identical to non-idmapped mounts: reading filesystem caps from disk
enforces that the root uid associated with the filesystem capability
must have a mapping in the superblock's user namespace and that the
caller is either in the same user namespace or is a descendant of the
superblock's user namespace. For filesystems that are mountable inside
user namespace the caller can just mount the filesystem and won't
usually need to idmap it. If they do want to idmap it they can create an
idmapped mount and mark it with a user namespace they created and which
is thus a descendant of s_user_ns. For filesystems that are not
mountable inside user namespaces the descendant rule is trivially true
because the s_user_ns will be the initial user namespace.

If the initial user namespace is passed nothing changes so non-idmapped
mounts will see identical behavior as before.

Link: https://lore.kernel.org/r/20210121131959.646623-11-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: James Morris <jamorris@linux.microsoft.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2021-01-24 14:27:17 +01:00
Christian Brauner 21cb47be6f
inode: make init and permission helpers idmapped mount aware
The inode_owner_or_capable() helper determines whether the caller is the
owner of the inode or is capable with respect to that inode. Allow it to
handle idmapped mounts. If the inode is accessed through an idmapped
mount it according to the mount's user namespace. Afterwards the checks
are identical to non-idmapped mounts. If the initial user namespace is
passed nothing changes so non-idmapped mounts will see identical
behavior as before.

Similarly, allow the inode_init_owner() helper to handle idmapped
mounts. It initializes a new inode on idmapped mounts by mapping the
fsuid and fsgid of the caller from the mount's user namespace. If the
initial user namespace is passed nothing changes so non-idmapped mounts
will see identical behavior as before.

Link: https://lore.kernel.org/r/20210121131959.646623-7-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: James Morris <jamorris@linux.microsoft.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2021-01-24 14:27:16 +01:00
Christian Brauner 47291baa8d
namei: make permission helpers idmapped mount aware
The two helpers inode_permission() and generic_permission() are used by
the vfs to perform basic permission checking by verifying that the
caller is privileged over an inode. In order to handle idmapped mounts
we extend the two helpers with an additional user namespace argument.
On idmapped mounts the two helpers will make sure to map the inode
according to the mount's user namespace and then peform identical
permission checks to inode_permission() and generic_permission(). If the
initial user namespace is passed nothing changes so non-idmapped mounts
will see identical behavior as before.

Link: https://lore.kernel.org/r/20210121131959.646623-6-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: James Morris <jamorris@linux.microsoft.com>
Acked-by: Serge Hallyn <serge@hallyn.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2021-01-24 14:27:16 +01:00
Christian Brauner 0558c1bf5a
capability: handle idmapped mounts
In order to determine whether a caller holds privilege over a given
inode the capability framework exposes the two helpers
privileged_wrt_inode_uidgid() and capable_wrt_inode_uidgid(). The former
verifies that the inode has a mapping in the caller's user namespace and
the latter additionally verifies that the caller has the requested
capability in their current user namespace.
If the inode is accessed through an idmapped mount map it into the
mount's user namespace. Afterwards the checks are identical to
non-idmapped inodes. If the initial user namespace is passed all
operations are a nop so non-idmapped mounts will not see a change in
behavior.

Link: https://lore.kernel.org/r/20210121131959.646623-5-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: James Morris <jamorris@linux.microsoft.com>
Acked-by: Serge Hallyn <serge@hallyn.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2021-01-24 14:27:16 +01:00
Christian Brauner 02f92b3868
fs: add file and path permissions helpers
Add two simple helpers to check permissions on a file and path
respectively and convert over some callers. It simplifies quite a few
codepaths and also reduces the churn in later patches quite a bit.
Christoph also correctly points out that this makes codepaths (e.g.
ioctls) way easier to follow that would otherwise have to do more
complex argument passing than necessary.

Link: https://lore.kernel.org/r/20210121131959.646623-4-christian.brauner@ubuntu.com
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Suggested-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: James Morris <jamorris@linux.microsoft.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2021-01-24 14:27:16 +01:00
Paul E. McKenney 0d2460ba61 Merge branches 'doc.2021.01.06a', 'fixes.2021.01.04b', 'kfree_rcu.2021.01.04a', 'mmdumpobj.2021.01.22a', 'nocb.2021.01.06a', 'rt.2021.01.04a', 'stall.2021.01.06a', 'torture.2021.01.12a' and 'tortureall.2021.01.06a' into HEAD
doc.2021.01.06a: Documentation updates.
fixes.2021.01.04b: Miscellaneous fixes.
kfree_rcu.2021.01.04a: kfree_rcu() updates.
mmdumpobj.2021.01.22a: Dump allocation point for memory blocks.
nocb.2021.01.06a: RCU callback offload updates and cblist segment lengths.
rt.2021.01.04a: Real-time updates.
stall.2021.01.06a: RCU CPU stall warning updates.
torture.2021.01.12a: Torture-test updates and polling SRCU grace-period API.
tortureall.2021.01.06a: Torture-test script updates.
2021-01-22 15:26:44 -08:00
Paul E. McKenney b4b7914a6a rcu: Make call_rcu() print mem_dump_obj() info for double-freed callback
The debug-object double-free checks in __call_rcu() print out the
RCU callback function, which is usually sufficient to track down the
double free.  However, all uses of things like queue_rcu_work() will
have the same RCU callback function (rcu_work_rcufn() in this case),
so a diagnostic message for a double queue_rcu_work() needs more than
just the callback function.

This commit therefore calls mem_dump_obj() to dump out any additional
available information on the double-freed callback.

Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: <linux-mm@kvack.org>
Reported-by: Andrii Nakryiko <andrii@kernel.org>
Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-22 15:24:16 -08:00
Tobias Klauser 18b24d78d5 bpf: Fix typo in scalar{,32}_min_max_rsh comments
s/bounts/bounds/

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210121174324.24127-1-tklauser@distanz.ch
2021-01-23 00:23:23 +01:00
Pan Bian b9557caaf8 bpf, inode_storage: Put file handler if no storage was found
Put file f if inode_storage_ptr() returns NULL.

Fixes: 8ea636848a ("bpf: Implement bpf_local_storage for inodes")
Signed-off-by: Pan Bian <bianpan2016@163.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: KP Singh <kpsingh@kernel.org>
Link: https://lore.kernel.org/bpf/20210121020856.25507-1-bianpan2016@163.com
2021-01-22 23:19:24 +01:00
Loris Reiff f4a2da755a bpf, cgroup: Fix problematic bounds check
Since ctx.optlen is signed, a larger value than max_value could be
passed, as it is later on used as unsigned, which causes a WARN_ON_ONCE
in the copy_to_user.

Fixes: 0d01da6afc ("bpf: implement getsockopt and setsockopt hooks")
Signed-off-by: Loris Reiff <loris.reiff@liblor.ch>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/bpf/20210122164232.61770-2-loris.reiff@liblor.ch
2021-01-22 23:11:47 +01:00
Loris Reiff bb8b81e396 bpf, cgroup: Fix optlen WARN_ON_ONCE toctou
A toctou issue in `__cgroup_bpf_run_filter_getsockopt` can trigger a
WARN_ON_ONCE in a check of `copy_from_user`.

`*optlen` is checked to be non-negative in the individual getsockopt
functions beforehand. Changing `*optlen` in a race to a negative value
will result in a `copy_from_user(ctx.optval, optval, ctx.optlen)` with
`ctx.optlen` being a negative integer.

Fixes: 0d01da6afc ("bpf: implement getsockopt and setsockopt hooks")
Signed-off-by: Loris Reiff <loris.reiff@liblor.ch>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/bpf/20210122164232.61770-1-loris.reiff@liblor.ch
2021-01-22 23:11:34 +01:00
Peter Zijlstra 741ba80f6f sched: Relax the set_cpus_allowed_ptr() semantics
Now that we have KTHREAD_IS_PER_CPU to denote the critical per-cpu
tasks to retain during CPU offline, we can relax the warning in
set_cpus_allowed_ptr(). Any spurious kthread that wants to get on at
the last minute will get pushed off before it can run.

While during CPU online there is no harm, and actual benefit, to
allowing kthreads back on early, it simplifies hotplug code and fixes
a number of outstanding races.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Lai jiangshan <jiangshanlai@gmail.com>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Tested-by: Valentin Schneider <valentin.schneider@arm.com>
Link: https://lkml.kernel.org/r/20210121103507.240724591@infradead.org
2021-01-22 15:09:44 +01:00
Peter Zijlstra 5ba2ffba13 sched: Fix CPU hotplug / tighten is_per_cpu_kthread()
Prior to commit 1cf12e08bc ("sched/hotplug: Consolidate task
migration on CPU unplug") we'd leave any task on the dying CPU and
break affinity and force them off at the very end.

This scheme had to change in order to enable migrate_disable(). One
cannot wait for migrate_disable() to complete while stuck in
stop_machine(). Furthermore, since we need at the very least: idle,
hotplug and stop threads at any point before stop_machine, we can't
break affinity and/or push those away.

Under the assumption that all per-cpu kthreads are sanely handled by
CPU hotplug, the new code no long breaks affinity or migrates any of
them (which then includes the critical ones above).

However, there's an important difference between per-cpu kthreads and
kthreads that happen to have a single CPU affinity which is lost. The
latter class very much relies on the forced affinity breaking and
migration semantics previously provided.

Use the new kthread_is_per_cpu() infrastructure to tighten
is_per_cpu_kthread() and fix the hot-unplug problems stemming from the
change.

Fixes: 1cf12e08bc ("sched/hotplug: Consolidate task migration on CPU unplug")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Tested-by: Valentin Schneider <valentin.schneider@arm.com>
Link: https://lkml.kernel.org/r/20210121103507.102416009@infradead.org
2021-01-22 15:09:44 +01:00
Peter Zijlstra 975707f227 sched: Prepare to use balance_push in ttwu()
In preparation of using the balance_push state in ttwu() we need it to
provide a reliable and consistent state.

The immediate problem is that rq->balance_callback gets cleared every
schedule() and then re-set in the balance_push_callback() itself. This
is not a reliable signal, so add a variable that stays set during the
entire time.

Also move setting it before the synchronize_rcu() in
sched_cpu_deactivate(), such that we get guaranteed visibility to
ttwu(), which is a preempt-disable region.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Tested-by: Valentin Schneider <valentin.schneider@arm.com>
Link: https://lkml.kernel.org/r/20210121103506.966069627@infradead.org
2021-01-22 15:09:43 +01:00
Peter Zijlstra 640f17c824 workqueue: Restrict affinity change to rescuer
create_worker() will already set the right affinity using
kthread_bind_mask(), this means only the rescuer will need to change
it's affinity.

Howveer, while in cpu-hot-unplug a regular task is not allowed to run
on online&&!active as it would be pushed away quite agressively. We
need KTHREAD_IS_PER_CPU to survive in that environment.

Therefore set the affinity after getting that magic flag.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Tested-by: Valentin Schneider <valentin.schneider@arm.com>
Link: https://lkml.kernel.org/r/20210121103506.826629830@infradead.org
2021-01-22 15:09:43 +01:00
Peter Zijlstra 5c25b5ff89 workqueue: Tag bound workers with KTHREAD_IS_PER_CPU
Mark the per-cpu workqueue workers as KTHREAD_IS_PER_CPU.

Workqueues have unfortunate semantics in that per-cpu workers are not
default flushed and parked during hotplug, however a subset does
manual flush on hotplug and hard relies on them for correctness.

Therefore play silly games..

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Tested-by: Valentin Schneider <valentin.schneider@arm.com>
Link: https://lkml.kernel.org/r/20210121103506.693465814@infradead.org
2021-01-22 15:09:42 +01:00
Peter Zijlstra ac687e6e8c kthread: Extract KTHREAD_IS_PER_CPU
There is a need to distinguish geniune per-cpu kthreads from kthreads
that happen to have a single CPU affinity.

Geniune per-cpu kthreads are kthreads that are CPU affine for
correctness, these will obviously have PF_KTHREAD set, but must also
have PF_NO_SETAFFINITY set, lest userspace modify their affinity and
ruins things.

However, these two things are not sufficient, PF_NO_SETAFFINITY is
also set on other tasks that have their affinities controlled through
other means, like for instance workqueues.

Therefore another bit is needed; it turns out kthread_create_per_cpu()
already has such a bit: KTHREAD_IS_PER_CPU, which is used to make
kthread_park()/kthread_unpark() work correctly.

Expose this flag and remove the implicit setting of it from
kthread_create_on_cpu(); the io_uring usage of it seems dubious at
best.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Tested-by: Valentin Schneider <valentin.schneider@arm.com>
Link: https://lkml.kernel.org/r/20210121103506.557620262@infradead.org
2021-01-22 15:09:42 +01:00
Peter Zijlstra 22f667c97a sched: Don't run cpu-online with balance_push() enabled
We don't need to push away tasks when we come online, mark the push
complete right before the CPU dies.

XXX hotplug state machine has trouble with rollback here.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Tested-by: Valentin Schneider <valentin.schneider@arm.com>
Link: https://lkml.kernel.org/r/20210121103506.415606087@infradead.org
2021-01-22 15:09:42 +01:00
Lai Jiangshan 547a77d02f workqueue: Use cpu_possible_mask instead of cpu_active_mask to break affinity
The scheduler won't break affinity for us any more, and we should
"emulate" the same behavior when the scheduler breaks affinity for
us.  The behavior is "changing the cpumask to cpu_possible_mask".

And there might be some other CPUs online later while the worker is
still running with the pending work items.  The worker should be allowed
to use the later online CPUs as before and process the work items ASAP.
If we use cpu_active_mask here, we can't achieve this goal but
using cpu_possible_mask can.

Fixes: 06249738a4 ("workqueue: Manually break affinity on hotplug")
Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Acked-by: Tejun Heo <tj@kernel.org>
Tested-by: Paul E. McKenney <paulmck@kernel.org>
Tested-by: Valentin Schneider <valentin.schneider@arm.com>
Link: https://lkml.kernel.org/r/20210111152638.2417-4-jiangshanlai@gmail.com
2021-01-22 15:09:41 +01:00
Valentin Schneider 36c6e17bf1 sched/core: Print out straggler tasks in sched_cpu_dying()
Since commit

  1cf12e08bc ("sched/hotplug: Consolidate task migration on CPU unplug")

tasks are expected to move themselves out of a out-going CPU. For most
tasks this will be done automagically via BALANCE_PUSH, but percpu kthreads
will have to cooperate and move themselves away one way or another.

Currently, some percpu kthreads (workqueues being a notable exemple) do not
cooperate nicely and can end up on an out-going CPU at the time
sched_cpu_dying() is invoked.

Print the dying rq's tasks to shed some light on the stragglers.

Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Tested-by: Valentin Schneider <valentin.schneider@arm.com>
Link: https://lkml.kernel.org/r/20210113183141.11974-1-valentin.schneider@arm.com
2021-01-22 15:09:41 +01:00
Mark Rutland 997acaf6b4 lockdep: report broken irq restoration
We generally expect local_irq_save() and local_irq_restore() to be
paired and sanely nested, and so local_irq_restore() expects to be
called with irqs disabled. Thus, within local_irq_restore() we only
trace irq flag changes when unmasking irqs.

This means that a sequence such as:

| local_irq_disable();
| local_irq_save(flags);
| local_irq_enable();
| local_irq_restore(flags);

... is liable to break things, as the local_irq_restore() would mask
irqs without tracing this change. Similar problems may exist for
architectures whose arch_irq_restore() function depends on being called
with irqs disabled.

We don't consider such sequences to be a good idea, so let's define
those as forbidden, and add tooling to detect such broken cases.

This patch adds debug code to WARN() when raw_local_irq_restore() is
called with irqs enabled. As raw_local_irq_restore() is expected to pair
with raw_local_irq_save(), it should never be called with irqs enabled.

To avoid the possibility of circular header dependencies between
irqflags.h and bug.h, the warning is handled in a separate C file.

The new code is all conditional on a new CONFIG_DEBUG_IRQFLAGS symbol
which is independent of CONFIG_TRACE_IRQFLAGS. As noted above such cases
will confuse lockdep, so CONFIG_DEBUG_LOCKDEP now selects
CONFIG_DEBUG_IRQFLAGS.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20210111153707.10071-1-mark.rutland@arm.com
2021-01-22 11:08:56 +01:00
Linus Torvalds 2561bbbe2e Printk fixes for 5.11-rc5
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Merge tag 'printk-for-5.11-printk-rework-fixup' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux

Pull printk fixes from Petr Mladek:

 - Fix line counting and buffer size calculation. Both regressions
   caused that a reader buffer might not get filled as much as possible.

 - Restore non-documented behavior of printk() reader API and make it
   official.

   It did not fill the last byte of the provided buffer before 5.10. Two
   architectures, powerpc and um, used it to add the trailing '\0'.
   There might theoretically be more callers depending on this behavior
   in userspace.

* tag 'printk-for-5.11-printk-rework-fixup' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux:
  printk: fix buffer overflow potential for print_text()
  printk: fix kmsg_dump_get_buffer length calulations
  printk: ringbuffer: fix line counting
2021-01-21 11:37:22 -08:00
Petr Mladek 535b6a122c Merge branch 'printk-rework' into for-linus 2021-01-21 16:06:21 +01:00
Stanislav Fomichev a9ed15dae0 bpf: Split cgroup_bpf_enabled per attach type
When we attach any cgroup hook, the rest (even if unused/unattached) start
to contribute small overhead. In particular, the one we want to avoid is
__cgroup_bpf_run_filter_skb which does two redirections to get to
the cgroup and pushes/pulls skb.

Let's split cgroup_bpf_enabled to be per-attach to make sure
only used attach types trigger.

I've dropped some existing high-level cgroup_bpf_enabled in some
places because BPF_PROG_CGROUP_XXX_RUN macros usually have another
cgroup_bpf_enabled check.

I also had to copy-paste BPF_CGROUP_RUN_SA_PROG_LOCK for
GETPEERNAME/GETSOCKNAME because type for cgroup_bpf_enabled[type]
has to be constant and known at compile time.

Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20210115163501.805133-4-sdf@google.com
2021-01-20 14:23:00 -08:00
Stanislav Fomichev 20f2505fb4 bpf: Try to avoid kzalloc in cgroup/{s,g}etsockopt
When we attach a bpf program to cgroup/getsockopt any other getsockopt()
syscall starts incurring kzalloc/kfree cost.

Let add a small buffer on the stack and use it for small (majority)
{s,g}etsockopt values. The buffer is small enough to fit into
the cache line and cover the majority of simple options (most
of them are 4 byte ints).

It seems natural to do the same for setsockopt, but it's a bit more
involved when the BPF program modifies the data (where we have to
kmalloc). The assumption is that for the majority of setsockopt
calls (which are doing pure BPF options or apply policy) this
will bring some benefit as well.

Without this patch (we remove about 1% __kmalloc):
     3.38%     0.07%  tcp_mmap  [kernel.kallsyms]  [k] __cgroup_bpf_run_filter_getsockopt
            |
             --3.30%--__cgroup_bpf_run_filter_getsockopt
                       |
                        --0.81%--__kmalloc

Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20210115163501.805133-3-sdf@google.com
2021-01-20 14:23:00 -08:00
Stanislav Fomichev 9cacf81f81 bpf: Remove extra lock_sock for TCP_ZEROCOPY_RECEIVE
Add custom implementation of getsockopt hook for TCP_ZEROCOPY_RECEIVE.
We skip generic hooks for TCP_ZEROCOPY_RECEIVE and have a custom
call in do_tcp_getsockopt using the on-stack data. This removes
3% overhead for locking/unlocking the socket.

Without this patch:
     3.38%     0.07%  tcp_mmap  [kernel.kallsyms]  [k] __cgroup_bpf_run_filter_getsockopt
            |
             --3.30%--__cgroup_bpf_run_filter_getsockopt
                       |
                        --0.81%--__kmalloc

With the patch applied:
     0.52%     0.12%  tcp_mmap  [kernel.kallsyms]  [k] __cgroup_bpf_run_filter_getsockopt_kern

Note, exporting uapi/tcp.h requires removing netinet/tcp.h
from test_progs.h because those headers have confliciting
definitions.

Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20210115163501.805133-2-sdf@google.com
2021-01-20 14:23:00 -08:00
Yonghong Song 13ca51d5eb bpf: Permit size-0 datasec
llvm patch https://reviews.llvm.org/D84002 permitted
to emit empty rodata datasec if the elf .rodata section
contains read-only data from local variables. These
local variables will be not emitted as BTF_KIND_VARs
since llvm converted these local variables as
static variables with private linkage without debuginfo
types. Such an empty rodata datasec will make
skeleton code generation easy since for skeleton
a rodata struct will be generated if there is a
.rodata elf section. The existence of a rodata
btf datasec is also consistent with the existence
of a rodata map created by libbpf.

The btf with such an empty rodata datasec will fail
in the kernel though as kernel will reject a datasec
with zero vlen and zero size. For example, for the below code,
    int sys_enter(void *ctx)
    {
       int fmt[6] = {1, 2, 3, 4, 5, 6};
       int dst[6];

       bpf_probe_read(dst, sizeof(dst), fmt);
       return 0;
    }
We got the below btf (bpftool btf dump ./test.o):
    [1] PTR '(anon)' type_id=0
    [2] FUNC_PROTO '(anon)' ret_type_id=3 vlen=1
            'ctx' type_id=1
    [3] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED
    [4] FUNC 'sys_enter' type_id=2 linkage=global
    [5] INT 'char' size=1 bits_offset=0 nr_bits=8 encoding=SIGNED
    [6] ARRAY '(anon)' type_id=5 index_type_id=7 nr_elems=4
    [7] INT '__ARRAY_SIZE_TYPE__' size=4 bits_offset=0 nr_bits=32 encoding=(none)
    [8] VAR '_license' type_id=6, linkage=global-alloc
    [9] DATASEC '.rodata' size=0 vlen=0
    [10] DATASEC 'license' size=0 vlen=1
            type_id=8 offset=0 size=4
When loading the ./test.o to the kernel with bpftool,
we see the following error:
    libbpf: Error loading BTF: Invalid argument(22)
    libbpf: magic: 0xeb9f
    ...
    [6] ARRAY (anon) type_id=5 index_type_id=7 nr_elems=4
    [7] INT __ARRAY_SIZE_TYPE__ size=4 bits_offset=0 nr_bits=32 encoding=(none)
    [8] VAR _license type_id=6 linkage=1
    [9] DATASEC .rodata size=24 vlen=0 vlen == 0
    libbpf: Error loading .BTF into kernel: -22. BTF is optional, ignoring.

Basically, libbpf changed .rodata datasec size to 24 since elf .rodata
section size is 24. The kernel then rejected the BTF since vlen = 0.
Note that the above kernel verifier failure can be worked around with
changing local variable "fmt" to a static or global, optionally const, variable.

This patch permits a datasec with vlen = 0 in kernel.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210119153519.3901963-1-yhs@fb.com
2021-01-20 14:14:09 -08:00
Lorenzo Bianconi 97a0e1ea7b net, xdp: Introduce __xdp_build_skb_from_frame utility routine
Introduce __xdp_build_skb_from_frame utility routine to build
the skb from xdp_frame. Rely on __xdp_build_skb_from_frame in
cpumap code.

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Link: https://lore.kernel.org/bpf/4f9f4c6b3dd3933770c617eb6689dbc0c6e25863.1610475660.git.lorenzo@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2021-01-20 14:10:35 -08:00
Jakub Kicinski 0fe2f273ab Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Conflicts:

drivers/net/can/dev.c
  commit 03f16c5075 ("can: dev: can_restart: fix use after free bug")
  commit 3e77f70e73 ("can: dev: move driver related infrastructure into separate subdir")

  Code move.

drivers/net/dsa/b53/b53_common.c
 commit 8e4052c32d ("net: dsa: b53: fix an off by one in checking "vlan->vid"")
 commit b7a9e0da2d ("net: switchdev: remove vid_begin -> vid_end range from VLAN objects")

 Field rename.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-20 12:16:11 -08:00
Linus Torvalds 75439bc439 Networking fixes for 5.11-rc5, including fixes from bpf, wireless,
and can trees.
 
 Current release - regressions:
 
  - nfc: nci: fix the wrong NCI_CORE_INIT parameters
 
 Current release - new code bugs:
 
  - bpf: allow empty module BTFs
 
 Previous releases - regressions:
 
  - bpf: fix signed_{sub,add32}_overflows type handling
 
  - tcp: do not mess with cloned skbs in tcp_add_backlog()
 
  - bpf: prevent double bpf_prog_put call from bpf_tracing_prog_attach
 
  - bpf: don't leak memory in bpf getsockopt when optlen == 0
 
  - tcp: fix potential use-after-free due to double kfree()
 
  - mac80211: fix encryption issues with WEP
 
  - devlink: use right genl user_ptr when handling port param get/set
 
  - ipv6: set multicast flag on the multicast route
 
  - tcp: fix TCP_USER_TIMEOUT with zero window
 
 Previous releases - always broken:
 
  - bpf: local storage helpers should check nullness of owner ptr passed
 
  - mac80211: fix incorrect strlen of .write in debugfs
 
  - cls_flower: call nla_ok() before nla_next()
 
  - skbuff: back tiny skbs with kmalloc() in __netdev_alloc_skb() too
 
 Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Merge tag 'net-5.11-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

Pull networking fixes from Jakub Kicinski:
 "Networking fixes for 5.11-rc5, including fixes from bpf, wireless, and
  can trees.

  Current release - regressions:

   - nfc: nci: fix the wrong NCI_CORE_INIT parameters

  Current release - new code bugs:

   - bpf: allow empty module BTFs

  Previous releases - regressions:

   - bpf: fix signed_{sub,add32}_overflows type handling

   - tcp: do not mess with cloned skbs in tcp_add_backlog()

   - bpf: prevent double bpf_prog_put call from bpf_tracing_prog_attach

   - bpf: don't leak memory in bpf getsockopt when optlen == 0

   - tcp: fix potential use-after-free due to double kfree()

   - mac80211: fix encryption issues with WEP

   - devlink: use right genl user_ptr when handling port param get/set

   - ipv6: set multicast flag on the multicast route

   - tcp: fix TCP_USER_TIMEOUT with zero window

  Previous releases - always broken:

   - bpf: local storage helpers should check nullness of owner ptr passed

   - mac80211: fix incorrect strlen of .write in debugfs

   - cls_flower: call nla_ok() before nla_next()

   - skbuff: back tiny skbs with kmalloc() in __netdev_alloc_skb() too"

* tag 'net-5.11-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (52 commits)
  net: systemport: free dev before on error path
  net: usb: cdc_ncm: don't spew notifications
  net: mscc: ocelot: Fix multicast to the CPU port
  tcp: Fix potential use-after-free due to double kfree()
  bpf: Fix signed_{sub,add32}_overflows type handling
  can: peak_usb: fix use after free bugs
  can: vxcan: vxcan_xmit: fix use after free bug
  can: dev: can_restart: fix use after free bug
  tcp: fix TCP socket rehash stats mis-accounting
  net: dsa: b53: fix an off by one in checking "vlan->vid"
  tcp: do not mess with cloned skbs in tcp_add_backlog()
  selftests: net: fib_tests: remove duplicate log test
  net: nfc: nci: fix the wrong NCI_CORE_INIT parameters
  sh_eth: Fix power down vs. is_opened flag ordering
  net: Disable NETIF_F_HW_TLS_RX when RXCSUM is disabled
  netfilter: rpfilter: mask ecn bits before fib lookup
  udp: mask TOS bits in udp_v4_early_demux()
  xsk: Clear pool even for inactive queues
  bpf: Fix helper bpf_map_peek_elem_proto pointing to wrong callback
  sh_eth: Make PHY access aware of Runtime PM to fix reboot crash
  ...
2021-01-20 11:52:21 -08:00
Daniel Borkmann bc895e8b2a bpf: Fix signed_{sub,add32}_overflows type handling
Fix incorrect signed_{sub,add32}_overflows() input types (and a related buggy
comment). It looks like this might have slipped in via copy/paste issue, also
given prior to 3f50f132d8 ("bpf: Verifier, do explicit ALU32 bounds tracking")
the signature of signed_sub_overflows() had s64 a and s64 b as its input args
whereas now they are truncated to s32. Thus restore proper types. Also, the case
of signed_add32_overflows() is not consistent to signed_sub32_overflows(). Both
have s32 as inputs, therefore align the former.

Fixes: 3f50f132d8 ("bpf: Verifier, do explicit ALU32 bounds tracking")
Reported-by: De4dCr0w <sa516203@mail.ustc.edu.cn>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
2021-01-20 17:19:40 +01:00
Linus Torvalds 45dfb8a565 task_work-2021-01-19
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Merge tag 'task_work-2021-01-19' of git://git.kernel.dk/linux-block

Pull task_work fix from Jens Axboe:
 "The TIF_NOTIFY_SIGNAL change inadvertently removed the unconditional
  task_work run we had in get_signal().

  This caused a regression for some setups, since we're relying on eg
  ____fput() being run to close and release, for example, a pipe and
  wake the other end.

  For 5.11, I prefer the simple solution of just reinstating the
  unconditional run, even if it conceptually doesn't make much sense -
  if you need that kind of guarantee, you should be using TWA_SIGNAL
  instead of TWA_NOTIFY. But it's the trivial fix for 5.11, and would
  ensure that other potential gotchas/assumptions for task_work don't
  regress for 5.11.

  We're looking into further simplifying the task_work notifications for
  5.12 which would resolve that too"

* tag 'task_work-2021-01-19' of git://git.kernel.dk/linux-block:
  task_work: unconditionally run task_work from get_signal()
2021-01-19 13:26:05 -08:00
Mircea Cirjaliu 301a33d518 bpf: Fix helper bpf_map_peek_elem_proto pointing to wrong callback
I assume this was obtained by copy/paste. Point it to bpf_map_peek_elem()
instead of bpf_map_pop_elem(). In practice it may have been less likely
hit when under JIT given shielded via 84430d4232 ("bpf, verifier: avoid
retpoline for map push/pop/peek operation").

Fixes: f1a2e44a3a ("bpf: add queue and stack maps")
Signed-off-by: Mircea Cirjaliu <mcirjaliu@bitdefender.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Mauricio Vasquez <mauriciovasquezbernal@gmail.com>
Link: https://lore.kernel.org/bpf/AM7PR02MB6082663DFDCCE8DA7A6DD6B1BBA30@AM7PR02MB6082.eurprd02.prod.outlook.com
2021-01-19 22:04:08 +01:00
Odin Ugedal 385aac1519 cgroup: fix psi monitor for root cgroup
Fix NULL pointer dereference when adding new psi monitor to the root
cgroup. PSI files for root cgroup was introduced in df5ba5be74 by using
system wide psi struct when reading, but file write/monitor was not
properly fixed. Since the PSI config for the root cgroup isn't
initialized, the current implementation tries to lock a NULL ptr,
resulting in a crash.

Can be triggered by running this as root:
$ tee /sys/fs/cgroup/cpu.pressure <<< "some 10000 1000000"

Signed-off-by: Odin Ugedal <odin@uged.al>
Reviewed-by: Suren Baghdasaryan <surenb@google.com>
Acked-by: Dan Schatzberg <dschatzberg@fb.com>
Fixes: df5ba5be74 ("kernel/sched/psi.c: expose pressure metrics on root cgroup")
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: stable@vger.kernel.org # 5.2+
Signed-off-by: Tejun Heo <tj@kernel.org>
2021-01-19 11:37:05 -05:00
John Ogness f0e386ee0c printk: fix buffer overflow potential for print_text()
Before the commit 896fbe20b4 ("printk: use the lockless
ringbuffer"), msg_print_text() would only write up to size-1 bytes
into the provided buffer. Some callers expect this behavior and
append a terminator to returned string. In particular:

arch/powerpc/xmon/xmon.c:dump_log_buf()
arch/um/kernel/kmsg_dump.c:kmsg_dumper_stdout()

msg_print_text() has been replaced by record_print_text(), which
currently fills the full size of the buffer. This causes a
buffer overflow for the above callers.

Change record_print_text() so that it will only use size-1 bytes
for text data. Also, for paranoia sakes, add a terminator after
the text data.

And finally, document this behavior so that it is clear that only
size-1 bytes are used and a terminator is added.

Fixes: 896fbe20b4 ("printk: use the lockless ringbuffer")
Cc: stable@vger.kernel.org # 5.10+
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20210114170412.4819-1-john.ogness@linutronix.de
2021-01-19 11:42:14 +01:00
Frank van der Linden ec2a29593c module: harden ELF info handling
5fdc7db644 ("module: setup load info before module_sig_check()")
moved the ELF setup, so that it was done before the signature
check. This made the module name available to signature error
messages.

However, the checks for ELF correctness in setup_load_info
are not sufficient to prevent bad memory references due to
corrupted offset fields, indices, etc.

So, there's a regression in behavior here: a corrupt and unsigned
(or badly signed) module, which might previously have been rejected
immediately, can now cause an oops/crash.

Harden ELF handling for module loading by doing the following:

- Move the signature check back up so that it comes before ELF
  initialization. It's best to do the signature check to see
  if we can trust the module, before using the ELF structures
  inside it. This also makes checks against info->len
  more accurate again, as this field will be reduced by the
  length of the signature in mod_check_sig().

  The module name is now once again not available for error
  messages during the signature check, but that seems like
  a fair tradeoff.

- Check if sections have offset / size fields that at least don't
  exceed the length of the module.

- Check if sections have section name offsets that don't fall
  outside the section name table.

- Add a few other sanity checks against invalid section indices,
  etc.

This is not an exhaustive consistency check, but the idea is to
at least get through the signature and blacklist checks without
crashing because of corrupted ELF info, and to error out gracefully
for most issues that would have caused problems later on.

Fixes: 5fdc7db644 ("module: setup load info before module_sig_check()")
Signed-off-by: Frank van der Linden <fllinden@amazon.com>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
2021-01-19 10:24:45 +01:00
Fangrui Song ebfac7b778 module: Ignore _GLOBAL_OFFSET_TABLE_ when warning for undefined symbols
clang-12 -fno-pic (since
a084c0388e)
can emit `call __stack_chk_fail@PLT` instead of `call __stack_chk_fail`
on x86.  The two forms should have identical behaviors on x86-64 but the
former causes GNU as<2.37 to produce an unreferenced undefined symbol
_GLOBAL_OFFSET_TABLE_.

(On x86-32, there is an R_386_PC32 vs R_386_PLT32 difference but the
linker behavior is identical as far as Linux kernel is concerned.)

Simply ignore _GLOBAL_OFFSET_TABLE_ for now, like what
scripts/mod/modpost.c:ignore_undef_symbol does. This also fixes the
problem for gcc/clang -fpie and -fpic, which may emit `call foo@PLT` for
external function calls on x86.

Note: ld -z defs and dynamic loaders do not error for unreferenced
undefined symbols so the module loader is reading too much.  If we ever
need to ignore more symbols, the code should be refactored to ignore
unreferenced symbols.

Cc: <stable@vger.kernel.org>
Link: https://github.com/ClangBuiltLinux/linux/issues/1250
Link: https://sourceware.org/bugzilla/show_bug.cgi?id=27178
Reported-by: Marco Elver <elver@google.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Tested-by: Marco Elver <elver@google.com>
Signed-off-by: Fangrui Song <maskray@google.com>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
2021-01-18 10:45:42 +01:00
Jakub Kicinski 2d9116be76 Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Daniel Borkmann says:

====================
pull-request: bpf-next 2021-01-16

1) Extend atomic operations to the BPF instruction set along with x86-64 JIT support,
   that is, atomic{,64}_{xchg,cmpxchg,fetch_{add,and,or,xor}}, from Brendan Jackman.

2) Add support for using kernel module global variables (__ksym externs in BPF
   programs) retrieved via module's BTF, from Andrii Nakryiko.

3) Generalize BPF stackmap's buildid retrieval and add support to have buildid
   stored in mmap2 event for perf, from Jiri Olsa.

4) Various fixes for cross-building BPF sefltests out-of-tree which then will
   unblock wider automated testing on ARM hardware, from Jean-Philippe Brucker.

5) Allow to retrieve SOL_SOCKET opts from sock_addr progs, from Daniel Borkmann.

6) Clean up driver's XDP buffer init and split into two helpers to init per-
   descriptor and non-changing fields during processing, from Lorenzo Bianconi.

7) Minor misc improvements to libbpf & bpftool, from Ian Rogers.

* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (41 commits)
  perf: Add build id data in mmap2 event
  bpf: Add size arg to build_id_parse function
  bpf: Move stack_map_get_build_id into lib
  bpf: Document new atomic instructions
  bpf: Add tests for new BPF atomic operations
  bpf: Add bitwise atomic instructions
  bpf: Pull out a macro for interpreting atomic ALU operations
  bpf: Add instructions for atomic_[cmp]xchg
  bpf: Add BPF_FETCH field / create atomic_fetch_add instruction
  bpf: Move BPF_STX reserved field check into BPF_STX verifier code
  bpf: Rename BPF_XADD and prepare to encode other atomics in .imm
  bpf: x86: Factor out a lookup table for some ALU opcodes
  bpf: x86: Factor out emission of REX byte
  bpf: x86: Factor out emission of ModR/M for *(reg + off)
  tools/bpftool: Add -Wall when building BPF programs
  bpf, libbpf: Avoid unused function warning on bpf_tail_call_static
  selftests/bpf: Install btf_dump test cases
  selftests/bpf: Fix installation of urandom_read
  selftests/bpf: Move generated test files to $(TEST_GEN_FILES)
  selftests/bpf: Fix out-of-tree build
  ...
====================

Link: https://lore.kernel.org/r/20210116012922.17823-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-15 17:57:26 -08:00
Jakub Kicinski e23a8d0021 Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Daniel Borkmann says:

====================
pull-request: bpf 2021-01-16

1) Fix a double bpf_prog_put() for BPF_PROG_{TYPE_EXT,TYPE_TRACING} types in
   link creation's error path causing a refcount underflow, from Jiri Olsa.

2) Fix BTF validation errors for the case where kernel modules don't declare
   any new types and end up with an empty BTF, from Andrii Nakryiko.

3) Fix BPF local storage helpers to first check their {task,inode} owners for
   being NULL before access, from KP Singh.

4) Fix a memory leak in BPF setsockopt handling for the case where optlen is
   zero and thus temporary optval buffer should be freed, from Stanislav Fomichev.

5) Fix a syzbot memory allocation splat in BPF_PROG_TEST_RUN infra for
   raw_tracepoint caused by too big ctx_size_in, from Song Liu.

6) Fix LLVM code generation issues with verifier where PTR_TO_MEM{,_OR_NULL}
   registers were spilled to stack but not recognized, from Gilad Reti.

* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
  MAINTAINERS: Update my email address
  selftests/bpf: Add verifier test for PTR_TO_MEM spill
  bpf: Support PTR_TO_MEM{,_OR_NULL} register spilling
  bpf: Reject too big ctx_size_in for raw_tp test run
  libbpf: Allow loading empty BTFs
  bpf: Allow empty module BTFs
  bpf: Don't leak memory in bpf getsockopt when optlen == 0
  bpf: Update local storage test to check handling of null ptrs
  bpf: Fix typo in bpf_inode_storage.c
  bpf: Local storage helpers should check nullness of owner ptr passed
  bpf: Prevent double bpf_prog_put call from bpf_tracing_prog_attach
====================

Link: https://lore.kernel.org/r/20210116002025.15706-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-15 16:34:59 -08:00
Aubrey Li 415de5fdeb cpuset: fix typos in comments
Change hierachy to hierarchy and congifured to configured, no functionality
changed.

Signed-off-by: Aubrey Li <aubrey.li@linux.intel.com>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
2021-01-15 15:36:41 -05:00
Michal Koutný da70862efe cgroup: cgroup.{procs,threads} factor out common parts
The functions cgroup_threads_write and cgroup_procs_write are almost
identical. In order to reduce duplication, factor out the common code in
similar fashion we already do for other threadgroup/task functions. No
functional changes are intended.

Suggested-by: Hao Lee <haolee.swjtu@gmail.com>
Signed-off-by: Michal Koutný <mkoutny@suse.com>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2021-01-15 15:36:18 -05:00
Chen Zhou 61e960b07b cgroup-v1: add disabled controller check in cgroup1_parse_param()
When mounting a cgroup hierarchy with disabled controller in cgroup v1,
all available controllers will be attached.
For example, boot with cgroup_no_v1=cpu or cgroup_disable=cpu, and then
mount with "mount -t cgroup -ocpu cpu /sys/fs/cgroup/cpu", then all
enabled controllers will be attached except cpu.

Fix this by adding disabled controller check in cgroup1_parse_param().
If the specified controller is disabled, just return error with information
"Disabled controller xx" rather than attaching all the other enabled
controllers.

Fixes: f5dfb5315d ("cgroup: take options parsing into ->parse_monolithic()")
Signed-off-by: Chen Zhou <chenzhou10@huawei.com>
Reviewed-by: Zefan Li <lizefan.x@bytedance.com>
Reviewed-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2021-01-15 15:10:37 -05:00
Davidlohr Bueso c1de44631e audit: Remove leftover reference to the audit_tasklet
This was replaced with a kauditd_wait kthread long ago,
back in:

     b7d1125817 (AUDIT: Send netlink messages from a separate kernel thread)

Update the stale comment.

Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2021-01-15 11:58:10 -05:00
John Ogness 89ccf18f03 printk: fix kmsg_dump_get_buffer length calulations
kmsg_dump_get_buffer() uses @syslog to determine if the syslog
prefix should be written to the buffer. However, when calculating
the maximum number of records that can fit into the buffer, it
always counts the bytes from the syslog prefix.

Use @syslog when calculating the maximum number of records that can
fit into the buffer.

Fixes: e2ae715d66 ("kmsg - kmsg_dump() use iterator to receive log buffer content")
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20210113164413.1599-1-john.ogness@linutronix.de
2021-01-15 11:32:52 +01:00
John Ogness 668af87f99 printk: ringbuffer: fix line counting
Counting text lines in a record simply involves counting the number
of newline characters (+1). However, it is searching the full data
block for newline characters, even though the text data can be (and
often is) a subset of that area. Since the extra area in the data
block was never initialized, the result is that extra newlines may
be seen and counted.

Restrict newline searching to the text data length.

Fixes: b6cf8b3f33 ("printk: add lockless ringbuffer")
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20210113144234.6545-1-john.ogness@linutronix.de
2021-01-15 11:30:03 +01:00
Jiri Olsa 88a16a1309 perf: Add build id data in mmap2 event
Adding support to carry build id data in mmap2 event.

The build id data replaces maj/min/ino/ino_generation
fields, which are also used to identify map's binary,
so it's ok to replace them with build id data:

  union {
          struct {
                  u32       maj;
                  u32       min;
                  u64       ino;
                  u64       ino_generation;
          };
          struct {
                  u8        build_id_size;
                  u8        __reserved_1;
                  u16       __reserved_2;
                  u8        build_id[20];
          };
  };

Replaced maj/min/ino/ino_generation fields give us size
of 24 bytes. We use 20 bytes for build id data, 1 byte
for size and rest is unused.

There's new misc bit for mmap2 to signal there's build
id data in it:

  #define PERF_RECORD_MISC_MMAP_BUILD_ID   (1 << 14)

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/bpf/20210114134044.1418404-4-jolsa@kernel.org
2021-01-14 19:29:58 -08:00
Jiri Olsa 921f88fc89 bpf: Add size arg to build_id_parse function
It's possible to have other build id types (other than default SHA1).
Currently there's also ld support for MD5 build id.

Adding size argument to build_id_parse function, that returns (if defined)
size of the parsed build id, so we can recognize the build id type.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210114134044.1418404-3-jolsa@kernel.org
2021-01-14 19:29:58 -08:00
Jiri Olsa bd7525dacd bpf: Move stack_map_get_build_id into lib
Moving stack_map_get_build_id into lib with
declaration in linux/buildid.h header:

  int build_id_parse(struct vm_area_struct *vma, unsigned char *build_id);

This function returns build id for given struct vm_area_struct.
There is no functional change to stack_map_get_build_id function.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20210114134044.1418404-2-jolsa@kernel.org
2021-01-14 19:29:58 -08:00
Brendan Jackman 981f94c3e9 bpf: Add bitwise atomic instructions
This adds instructions for

atomic[64]_[fetch_]and
atomic[64]_[fetch_]or
atomic[64]_[fetch_]xor

All these operations are isomorphic enough to implement with the same
verifier, interpreter, and x86 JIT code, hence being a single commit.

The main interesting thing here is that x86 doesn't directly support
the fetch_ version these operations, so we need to generate a CMPXCHG
loop in the JIT. This requires the use of two temporary registers,
IIUC it's safe to use BPF_REG_AX and x86's AUX_REG for this purpose.

Signed-off-by: Brendan Jackman <jackmanb@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210114181751.768687-10-jackmanb@google.com
2021-01-14 18:34:29 -08:00
Brendan Jackman 462910670e bpf: Pull out a macro for interpreting atomic ALU operations
Since the atomic operations that are added in subsequent commits are
all isomorphic with BPF_ADD, pull out a macro to avoid the
interpreter becoming dominated by lines of atomic-related code.

Note that this sacrificies interpreter performance (combining
STX_ATOMIC_W and STX_ATOMIC_DW into single switch case means that we
need an extra conditional branch to differentiate them) in favour of
compact and (relatively!) simple C code.

Signed-off-by: Brendan Jackman <jackmanb@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210114181751.768687-9-jackmanb@google.com
2021-01-14 18:34:29 -08:00
Brendan Jackman 5ffa25502b bpf: Add instructions for atomic_[cmp]xchg
This adds two atomic opcodes, both of which include the BPF_FETCH
flag. XCHG without the BPF_FETCH flag would naturally encode
atomic_set. This is not supported because it would be of limited
value to userspace (it doesn't imply any barriers). CMPXCHG without
BPF_FETCH woulud be an atomic compare-and-write. We don't have such
an operation in the kernel so it isn't provided to BPF either.

There are two significant design decisions made for the CMPXCHG
instruction:

 - To solve the issue that this operation fundamentally has 3
   operands, but we only have two register fields. Therefore the
   operand we compare against (the kernel's API calls it 'old') is
   hard-coded to be R0. x86 has similar design (and A64 doesn't
   have this problem).

   A potential alternative might be to encode the other operand's
   register number in the immediate field.

 - The kernel's atomic_cmpxchg returns the old value, while the C11
   userspace APIs return a boolean indicating the comparison
   result. Which should BPF do? A64 returns the old value. x86 returns
   the old value in the hard-coded register (and also sets a
   flag). That means return-old-value is easier to JIT, so that's
   what we use.

Signed-off-by: Brendan Jackman <jackmanb@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210114181751.768687-8-jackmanb@google.com
2021-01-14 18:34:29 -08:00
Brendan Jackman 5ca419f286 bpf: Add BPF_FETCH field / create atomic_fetch_add instruction
The BPF_FETCH field can be set in bpf_insn.imm, for BPF_ATOMIC
instructions, in order to have the previous value of the
atomically-modified memory location loaded into the src register
after an atomic op is carried out.

Suggested-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Brendan Jackman <jackmanb@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20210114181751.768687-7-jackmanb@google.com
2021-01-14 18:34:29 -08:00
Brendan Jackman c5bcb5eb4d bpf: Move BPF_STX reserved field check into BPF_STX verifier code
I can't find a reason why this code is in resolve_pseudo_ldimm64;
since I'll be modifying it in a subsequent commit, tidy it up.

Signed-off-by: Brendan Jackman <jackmanb@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20210114181751.768687-6-jackmanb@google.com
2021-01-14 18:34:29 -08:00
Brendan Jackman 91c960b005 bpf: Rename BPF_XADD and prepare to encode other atomics in .imm
A subsequent patch will add additional atomic operations. These new
operations will use the same opcode field as the existing XADD, with
the immediate discriminating different operations.

In preparation, rename the instruction mode BPF_ATOMIC and start
calling the zero immediate BPF_ADD.

This is possible (doesn't break existing valid BPF progs) because the
immediate field is currently reserved MBZ and BPF_ADD is zero.

All uses are removed from the tree but the BPF_XADD definition is
kept around to avoid breaking builds for people including kernel
headers.

Signed-off-by: Brendan Jackman <jackmanb@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Björn Töpel <bjorn.topel@gmail.com>
Link: https://lore.kernel.org/bpf/20210114181751.768687-5-jackmanb@google.com
2021-01-14 18:34:29 -08:00
Boqun Feng 5f2962401c locking/lockdep: Exclude local_lock_t from IRQ inversions
The purpose of local_lock_t is to abstract: preempt_disable() /
local_bh_disable() / local_irq_disable(). These are the traditional
means of gaining access to per-cpu data, but are fundamentally
non-preemptible.

local_lock_t provides a per-cpu lock, that on !PREEMPT_RT reduces to
no-ops, just like regular spinlocks do on UP.

This gives rise to:

	CPU0			CPU1

	local_lock(B)		spin_lock_irq(A)
	<IRQ>
	  spin_lock(A)		local_lock(B)

Where lockdep then figures things will lock up; which would be true if
B were any other kind of lock. However this is a false positive, no
such deadlock actually exists.

For !RT the above local_lock(B) is preempt_disable(), and there's
obviously no deadlock; alternatively, CPU0's B != CPU1's B.

For RT the argument is that since local_lock() nests inside
spin_lock(), it cannot be used in hardirq context, and therefore CPU0
cannot in fact happen. Even though B is a real lock, it is a
preemptible lock and any threaded-irq would simply schedule out and
let the preempted task (which holds B) continue such that the task on
CPU1 can make progress, after which the threaded-irq resumes and can
finish.

This means that we can never form an IRQ inversion on a local_lock
dependency, so terminate the graph walk when looking for IRQ
inversions when we encounter one.

One consequence is that (for LOCKDEP_SMALL) when we look for redundant
dependencies, A -> B is not redundant in the presence of A -> L -> B.

Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
[peterz: Changelog]
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2021-01-14 11:20:17 +01:00
Peter Zijlstra 175b1a60e8 locking/lockdep: Clean up check_redundant() a bit
In preparation for adding an TRACE_IRQFLAGS dependent skip function to
check_redundant(), move it below the TRACE_IRQFLAGS #ifdef.

While there, provide a stub function to reduce #ifdef usage.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2021-01-14 11:20:17 +01:00
Boqun Feng bc2dd71b28 locking/lockdep: Add a skip() function to __bfs()
Some __bfs() walks will have additional iteration constraints (beyond
the path being strong). Provide an additional function to allow
terminating graph walks.

Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2021-01-14 11:20:17 +01:00
Peter Zijlstra dfd5e3f5fe locking/lockdep: Mark local_lock_t
The local_lock_t's are special, because they cannot form IRQ
inversions, make sure we can tell them apart from the rest of the
locks.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2021-01-14 11:20:17 +01:00
Hui Su 65bcf072e2 sched: Use task_current() instead of 'rq->curr == p'
Use the task_current() function where appropriate.

No functional change.

Signed-off-by: Hui Su <sh_def@163.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Link: https://lkml.kernel.org/r/20201030173223.GA52339@rlk
2021-01-14 11:20:11 +01:00
Vincent Guittot e9b9734b74 sched/fair: Reduce cases for active balance
Active balance is triggered for a number of voluntary cases like misfit
or pinned tasks cases but also after that a number of load balance
attempts failed to migrate a task. There is no need to use active load
balance when the group is overloaded because an overloaded state means
that there is at least one waiting task. Nevertheless, the waiting task
is not selected and detached until the threshold becomes higher than its
load. This threshold increases with the number of failed lb (see the
condition if ((load >> env->sd->nr_balance_failed) > env->imbalance) in
detach_tasks()) and the waiting task will end up to be selected after a
number of attempts.

Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Link: https://lkml.kernel.org/r/20210107103325.30851-4-vincent.guittot@linaro.org
2021-01-14 11:20:11 +01:00
Vincent Guittot 8a41dfcda7 sched/fair: Don't set LBF_ALL_PINNED unnecessarily
Setting LBF_ALL_PINNED during active load balance is only valid when there
is only 1 running task on the rq otherwise this ends up increasing the
balance interval whereas other tasks could migrate after the next interval
once they become cache-cold as an example.

LBF_ALL_PINNED flag is now always set it by default. It is then cleared
when we find one task that can be pulled when calling detach_tasks() or
during active migration.

Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Link: https://lkml.kernel.org/r/20210107103325.30851-3-vincent.guittot@linaro.org
2021-01-14 11:20:11 +01:00
Vincent Guittot fc488ffd42 sched/fair: Skip idle cfs_rq
Don't waste time checking whether an idle cfs_rq could be the busiest
queue. Furthermore, this can end up selecting a cfs_rq with a high load
but being idle in case of migrate_load.

Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Link: https://lkml.kernel.org/r/20210107103325.30851-2-vincent.guittot@linaro.org
2021-01-14 11:20:10 +01:00
Xuewen Yan 8c1f560c1e sched/fair: Avoid stale CPU util_est value for schedutil in task dequeue
CPU (root cfs_rq) estimated utilization (util_est) is currently used in
dequeue_task_fair() to drive frequency selection before it is updated.

with:

CPU_util        : rq->cfs.avg.util_avg
CPU_util_est    : rq->cfs.avg.util_est
CPU_utilization : max(CPU_util, CPU_util_est)
task_util       : p->se.avg.util_avg
task_util_est   : p->se.avg.util_est

dequeue_task_fair():

    /* (1) CPU_util and task_util update + inform schedutil about
           CPU_utilization changes */
    for_each_sched_entity() /* 2 loops */
        (dequeue_entity() ->) update_load_avg() -> cfs_rq_util_change()
         -> cpufreq_update_util() ->...-> sugov_update_[shared\|single]
         -> sugov_get_util() -> cpu_util_cfs()

    /* (2) CPU_util_est and task_util_est update */
    util_est_dequeue()

cpu_util_cfs() uses CPU_utilization which could lead to a false (too
high) utilization value for schedutil in task ramp-down or ramp-up
scenarios during task dequeue.

To mitigate the issue split the util_est update (2) into:

 (A) CPU_util_est update in util_est_dequeue()
 (B) task_util_est update in util_est_update()

Place (A) before (1) and keep (B) where (2) is. The latter is necessary
since (B) relies on task_util update in (1).

Fixes: 7f65ea42eb ("sched/fair: Add util_est on top of PELT")
Signed-off-by: Xuewen Yan <xuewen.yan@unisoc.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://lkml.kernel.org/r/1608283672-18240-1-git-send-email-xuewen.yan94@gmail.com
2021-01-14 11:20:10 +01:00
Anna-Maria Behnsen e0b257c3b7 sched: Prevent raising SCHED_SOFTIRQ when CPU is !active
SCHED_SOFTIRQ is raised to trigger periodic load balancing. When CPU is not
active, CPU should not participate in load balancing.

The scheduler uses nohz.idle_cpus_mask to keep track of the CPUs which can
do idle load balancing. When bringing a CPU up the CPU is added to the mask
when it reaches the active state, but on teardown the CPU stays in the mask
until it goes offline and invokes sched_cpu_dying().

When SCHED_SOFTIRQ is raised on a !active CPU, there might be a pending
softirq when stopping the tick which triggers a warning in NOHZ code. The
SCHED_SOFTIRQ can also be raised by the scheduler tick which has the same
issue.

Therefore remove the CPU from nohz.idle_cpus_mask when it is marked
inactive and also prevent the scheduler_tick() from raising SCHED_SOFTIRQ
after this point.

Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Link: https://lkml.kernel.org/r/20201215104400.9435-1-anna-maria@linutronix.de
2021-01-14 11:20:09 +01:00
Viresh Kumar a5418be9df sched/core: Rename schedutil_cpu_util() and allow rest of the kernel to use it
There is nothing schedutil specific in schedutil_cpu_util(), rename it
to effective_cpu_util(). Also create and expose another wrapper
sched_cpu_util() which can be used by other parts of the kernel, like
thermal core (that will be done in a later commit).

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lkml.kernel.org/r/db011961fb3bb8bef1c0eda5cd64564637d3ef31.1607400596.git.viresh.kumar@linaro.org
2021-01-14 11:20:09 +01:00
Viresh Kumar 7d6a905f3d sched/core: Move schedutil_cpu_util() to core.c
There is nothing schedutil specific in schedutil_cpu_util(), move it to
core.c and define it only for CONFIG_SMP.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lkml.kernel.org/r/c921a362c78e1324f8ebc5aaa12f53e309c5a8a2.1607400596.git.viresh.kumar@linaro.org
2021-01-14 11:20:08 +01:00
Gilad Reti 744ea4e388 bpf: Support PTR_TO_MEM{,_OR_NULL} register spilling
Add support for pointer to mem register spilling, to allow the verifier
to track pointers to valid memory addresses. Such pointers are returned
for example by a successful call of the bpf_ringbuf_reserve helper.

The patch was partially contributed by CyberArk Software, Inc.

Fixes: 457f44363a ("bpf: Implement BPF ring buffer and verifier support for it")
Suggested-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Gilad Reti <gilad.reti@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: KP Singh <kpsingh@kernel.org>
Link: https://lore.kernel.org/bpf/20210113053810.13518-1-gilad.reti@gmail.com
2021-01-13 19:47:43 -08:00
Thomas Gleixner ce09ccc502 genirq: Export irq_check_status_bit()
One of the users can be built modular:

  ERROR: modpost: "irq_check_status_bit" [drivers/perf/arm_spe_pmu.ko] undefined!

Fixes: fdd0296304 ("genirq: Move status flag checks to core")
Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20201227192049.GA195845@roeck-us.net
2021-01-13 15:48:05 +01:00
Andrii Nakryiko 541c3bad8d bpf: Support BPF ksym variables in kernel modules
Add support for directly accessing kernel module variables from BPF programs
using special ldimm64 instructions. This functionality builds upon vmlinux
ksym support, but extends ldimm64 with src_reg=BPF_PSEUDO_BTF_ID to allow
specifying kernel module BTF's FD in insn[1].imm field.

During BPF program load time, verifier will resolve FD to BTF object and will
take reference on BTF object itself and, for module BTFs, corresponding module
as well, to make sure it won't be unloaded from under running BPF program. The
mechanism used is similar to how bpf_prog keeps track of used bpf_maps.

One interesting change is also in how per-CPU variable is determined. The
logic is to find .data..percpu data section in provided BTF, but both vmlinux
and module each have their own .data..percpu entries in BTF. So for module's
case, the search for DATASEC record needs to look at only module's added BTF
types. This is implemented with custom search function.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Acked-by: Hao Luo <haoluo@google.com>
Link: https://lore.kernel.org/bpf/20210112075520.4103414-6-andrii@kernel.org
2021-01-12 17:24:30 -08:00
Brendan Jackman 28a8add641 bpf: Fix a verifier message for alloc size helper arg
The error message here is misleading, the argument will be rejected unless
it is a known constant.

Signed-off-by: Brendan Jackman <jackmanb@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210112123913.2016804-1-jackmanb@google.com
2021-01-12 21:41:17 +01:00
Thomas Gleixner 4bae052dde irqchip fixes for 5.11, take #1
- Fix the MIPS CPU interrupt controller hierarchy
 - Simplify the PRUSS Kconfig entry
 - Eliminate trivial build warnings on the MIPS Loongson liointc
 - Fix error path in devm_platform_get_irqs_affinity()
 - Turn the BCM2836 IPI irq_eoi callback into irq_ack
 - Fix initialisation of on-stack msi_alloc_info
 - Cleanup spurious comma in irq-sl28cpld
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Merge tag 'irqchip-fixes-5.11-1' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into irq/urgent

Pull irqchip fixes from Marc Zyngier:

 - Fix the MIPS CPU interrupt controller hierarchy
 - Simplify the PRUSS Kconfig entry
 - Eliminate trivial build warnings on the MIPS Loongson liointc
 - Fix error path in devm_platform_get_irqs_affinity()
 - Turn the BCM2836 IPI irq_eoi callback into irq_ack
 - Fix initialisation of on-stack msi_alloc_info
 - Cleanup spurious comma in irq-sl28cpld

Link: https://lore.kernel.org/r/20210110110001.2328708-1-maz@kernel.org
2021-01-12 21:23:55 +01:00
Geert Uytterhoeven e3fab2f3de ntp: Fix RTC synchronization on 32-bit platforms
Due to an integer overflow, RTC synchronization now happens every 2s
instead of the intended 11 minutes.  Fix this by forcing 64-bit
arithmetic for the sync period calculation.

Annotate the other place which multiplies seconds for consistency as well.

Fixes: c9e6189fb0 ("ntp: Make the RTC synchronization more reliable")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210111103956.290378-1-geert+renesas@glider.be
2021-01-12 21:13:01 +01:00
Chunguang Xu aba428a0c6 timekeeping: Remove unused get_seconds()
The get_seconds() cleanup seems to have been completed, now it is
time to delete the legacy interface to avoid misuse later.

Signed-off-by: Chunguang Xu <brookxu@tencent.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/1606816351-26900-1-git-send-email-brookxu@tencent.com
2021-01-12 21:13:01 +01:00
Andrii Nakryiko bcc5e6162d bpf: Allow empty module BTFs
Some modules don't declare any new types and end up with an empty BTF,
containing only valid BTF header and no types or strings sections. This
currently causes BTF validation error. There is nothing wrong with such BTF,
so fix the issue by allowing module BTFs with no types or strings.

Fixes: 36e68442d1 ("bpf: Load and verify kernel module BTFs")
Reported-by: Christopher William Snowhill <chris@kode54.net>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210110070341.1380086-1-andrii@kernel.org
2021-01-12 21:11:30 +01:00
Peter Zijlstra 77ca93a6b1 locking/lockdep: Avoid noinstr warning for DEBUG_LOCKDEP
vmlinux.o: warning: objtool: lock_is_held_type()+0x60: call to check_flags.part.0() leaves .noinstr.text section

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210106144017.652218215@infradead.org
2021-01-12 21:10:59 +01:00
Peter Zijlstra 0afda3a888 locking/lockdep: Cure noinstr fail
When the compiler doesn't feel like inlining, it causes a noinstr
fail:

  vmlinux.o: warning: objtool: lock_is_held_type()+0xb: call to lockdep_enabled() leaves .noinstr.text section

Fixes: 4d004099a6 ("lockdep: Fix lockdep recursion")
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210106144017.592595176@infradead.org
2021-01-12 21:10:59 +01:00
Stanislav Fomichev 4be34f3d07 bpf: Don't leak memory in bpf getsockopt when optlen == 0
optlen == 0 indicates that the kernel should ignore BPF buffer
and use the original one from the user. We, however, forget
to free the temporary buffer that we've allocated for BPF.

Fixes: d8fe449a9c ("bpf: Don't return EINVAL from {get,set}sockopt when optlen > PAGE_SIZE")
Reported-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20210112162829.775079-1-sdf@google.com
2021-01-12 21:05:07 +01:00
KP Singh 84d571d46c bpf: Fix typo in bpf_inode_storage.c
Fix "gurranteed" -> "guaranteed" in bpf_inode_storage.c

Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: KP Singh <kpsingh@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210112075525.256820-4-kpsingh@kernel.org
2021-01-12 16:07:57 +01:00
KP Singh 1a9c72ad4c bpf: Local storage helpers should check nullness of owner ptr passed
The verifier allows ARG_PTR_TO_BTF_ID helper arguments to be NULL, so
helper implementations need to check this before dereferencing them.
This was already fixed for the socket storage helpers but not for task
and inode.

The issue can be reproduced by attaching an LSM program to
inode_rename hook (called when moving files) which tries to get the
inode of the new file without checking for its nullness and then trying
to move an existing file to a new path:

  mv existing_file new_file_does_not_exist

The report including the sample program and the steps for reproducing
the bug:

  https://lore.kernel.org/bpf/CANaYP3HWkH91SN=wTNO9FL_2ztHfqcXKX38SSE-JJ2voh+vssw@mail.gmail.com

Fixes: 4cf1bc1f10 ("bpf: Implement task local storage")
Fixes: 8ea636848a ("bpf: Implement bpf_local_storage for inodes")
Reported-by: Gilad Reti <gilad.reti@gmail.com>
Signed-off-by: KP Singh <kpsingh@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210112075525.256820-3-kpsingh@kernel.org
2021-01-12 16:07:56 +01:00
Daniel Vetter 71a1d8ed90 resource: Move devmem revoke code to resource framework
We want all iomem mmaps to consistently revoke ptes when the kernel
takes over and CONFIG_IO_STRICT_DEVMEM is enabled. This includes the
pci bar mmaps available through procfs and sysfs, which currently do
not revoke mappings.

To prepare for this, move the code from the /dev/kmem driver to
kernel/resource.c.

During review Jason spotted that barriers are used somewhat
inconsistently. Fix that up while we shuffle this code, since it
doesn't have an actual impact at runtime. Otherwise no semantic and
behavioural changes intended, just code extraction and adjusting
comments and names.

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Kees Cook <keescook@chromium.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: linux-mm@kvack.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-samsung-soc@vger.kernel.org
Cc: linux-media@vger.kernel.org
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: David Hildenbrand <david@redhat.com>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20201127164131.2244124-11-daniel.vetter@ffwll.ch
2021-01-12 14:26:31 +01:00
Jiri Olsa 5541075a34 bpf: Prevent double bpf_prog_put call from bpf_tracing_prog_attach
The bpf_tracing_prog_attach error path calls bpf_prog_put
on prog, which causes refcount underflow when it's called
from link_create function.

  link_create
    prog = bpf_prog_get              <-- get
    ...
    tracing_bpf_link_attach(prog..
      bpf_tracing_prog_attach(prog..
        out_put_prog:
          bpf_prog_put(prog);        <-- put

    if (ret < 0)
      bpf_prog_put(prog);            <-- put

Removing bpf_prog_put call from bpf_tracing_prog_attach
and making sure its callers call it instead.

Fixes: 4a1e7c0c63 ("bpf: Support attaching freplace programs to multiple attach points")
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210111191650.1241578-1-jolsa@kernel.org
2021-01-12 00:17:34 +01:00
Linus Torvalds a0d54b4f5b Blacklist properly on all archs
The way to blacklist notrace functions for kprobes was not using
 the proper kconfig which caused some archs (powerpc) from blacklisting
 them.
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Merge tag 'trace-v5.11-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fix from Steven Rostedt:
 "Blacklist properly on all archs.

  The code to blacklist notrace functions for kprobes was not using the
  right kconfig option, which caused some archs (powerpc) to possibly
  not blacklist them"

* tag 'trace-v5.11-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing/kprobes: Do the notrace functions check without kprobes on ftrace
2021-01-11 14:37:13 -08:00
Masami Hiramatsu 7bb83f6fc4 tracing/kprobes: Do the notrace functions check without kprobes on ftrace
Enable the notrace function check on the architecture which doesn't
support kprobes on ftrace but support dynamic ftrace. This notrace
function check is not only for the kprobes on ftrace but also
sw-breakpoint based kprobes.
Thus there is no reason to limit this check for the arch which
supports kprobes on ftrace.

This also changes the dependency of Kconfig. Because kprobe event
uses the function tracer's address list for identifying notrace
function, if the CONFIG_DYNAMIC_FTRACE=n, it can not check whether
the target function is notrace or not.

Link: https://lkml.kernel.org/r/20210105065730.2634785-1-naveen.n.rao@linux.vnet.ibm.com
Link: https://lkml.kernel.org/r/161007957862.114704.4512260007555399463.stgit@devnote2

Cc: stable@vger.kernel.org
Fixes: 45408c4f92 ("tracing: kprobes: Prohibit probing on notrace function")
Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-01-11 16:09:53 -05:00
Paul Cercueil 04b38d0125 seccomp: Add missing return in non-void function
We don't actually care about the value, since the kernel will panic
before that; but a value should nonetheless be returned, otherwise the
compiler will complain.

Fixes: 8112c4f140 ("seccomp: remove 2-phase API")
Cc: stable@vger.kernel.org # 4.7+
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210111172839.640914-1-paul@crapouillou.net
2021-01-11 12:05:14 -08:00
Yanfei Xu cb5021ca62
kthread: remove comments about old _do_fork() helper
The old _do_fork() helper has been removed in favor of kernel_clone().
Here correct some comments which still contain _do_fork()

Link: https://lore.kernel.org/r/20210111104807.18022-1-yanfei.xu@windriver.com
Cc: christian@brauner.io
Cc: linux-kernel@vger.kernel.org
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Yanfei Xu <yanfei.xu@windriver.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2021-01-11 15:11:56 +01:00
Alexander Guril 96e1e9846c
Kernel: fork.c: Fix coding style: Do not use {} around single-line statements
Fixed two coding style issues in kernel/fork.c
Do not use {} around single-line statements.

Cc: linux-kernel@vger.kernel.org
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Alexander Guril <alexander.guril02@gmail.com>
Link: https://lore.kernel.org/r/20201226114021.2589-1-alexander.guril02@gmail.com
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2021-01-11 12:55:01 +01:00
Jann Horn adc5d87572
signal: Add missing __user annotation to copy_siginfo_from_user_any
copy_siginfo_from_user_any() takes a userspace pointer as second
argument; annotate the parameter type accordingly.

Signed-off-by: Jann Horn <jannh@google.com>
Link: https://lore.kernel.org/r/20201207000252.138564-1-jannh@google.com
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2021-01-11 12:55:00 +01:00
Linus Torvalds 4ad9a28f56 Staging driver fixes for 5.11-rc3
Here are some small staging driver fixes for 5.11-rc3.  Nothing major,
 just resolving some reported issues:
 	- cleanup some remaining mentions of the ION drivers that were
 	  removed in 5.11-rc1
 	- comedi driver bugfix
 	- 2 error path memory leak fixes
 
 All have been in linux-next for a while with no reported issues.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'staging-5.11-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging

Pull staging driver fixes from Greg KH:
 "Here are some small staging driver fixes for 5.11-rc3. Nothing major,
  just resolving some reported issues:

   - cleanup some remaining mentions of the ION drivers that were
     removed in 5.11-rc1

   - comedi driver bugfix

   - two error path memory leak fixes

  All have been in linux-next for a while with no reported issues"

* tag 'staging-5.11-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
  staging: ION: remove some references to CONFIG_ION
  staging: mt7621-dma: Fix a resource leak in an error handling path
  Staging: comedi: Return -EFAULT if copy_to_user() fails
  staging: spmi: hisi-spmi-controller: Fix some error handling paths
2021-01-10 12:28:07 -08:00
Sami Tolvanen 3b15cdc159 tracing: move function tracer options to Kconfig
Move function tracer options to Kconfig to make it easier to add
new methods for generating __mcount_loc, and to make the options
available also when building kernel modules.

Note that FTRACE_MCOUNT_USE_* options are updated on rebuild and
therefore, work even if the .config was generated in a different
environment.

Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20201211184633.3213045-2-samitolvanen@google.com
2021-01-08 15:59:02 -08:00
Leah Neukirchen 619775c3cf bpf: Remove unnecessary <argp.h> include from preload/iterators
This program does not use argp (which is a glibcism). Instead include <errno.h>
directly, which was pulled in by <argp.h>.

Signed-off-by: Leah Neukirchen <leah@vuxu.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20201216100306.30942-1-leah@vuxu.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2021-01-08 13:39:24 -08:00
Jens Axboe 35d0b389f3 task_work: unconditionally run task_work from get_signal()
Song reported a boot regression in a kvm image with 5.11-rc, and bisected
it down to the below patch. Debugging this issue, turns out that the boot
stalled when a task is waiting on a pipe being released. As we no longer
run task_work from get_signal() unless it's queued with TWA_SIGNAL, the
task goes idle without running the task_work. This prevents ->release()
from being called on the pipe, which another boot task is waiting on.

For now, re-instate the unconditional task_work run from get_signal().
For 5.12, we'll collapse TWA_RESUME and TWA_SIGNAL, as it no longer
makes sense to have a distinction between the two. This will turn
task_work notification into a simple boolean, whether to notify or not.

Fixes: 98b89b649f ("signal: kill JOBCTL_TASK_WORK")
Reported-by: Song Liu <songliubraving@fb.com>
Tested-by: John Stultz <john.stultz@linaro.org>
Tested-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com> # LLVM/Clang version 11.0.1
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-01-08 09:14:21 -07:00
Jakub Kicinski 0565ff56cd Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Alexei Starovoitov says:

====================
pull-request: bpf 2021-01-07

We've added 4 non-merge commits during the last 10 day(s) which contain
a total of 4 files changed, 14 insertions(+), 7 deletions(-).

The main changes are:

1) Fix task_iter bug caused by the merge conflict resolution, from Yonghong.

2) Fix resolve_btfids for multiple type hierarchies, from Jiri.

* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
  bpftool: Fix compilation failure for net.o with older glibc
  tools/resolve_btfids: Warn when having multiple IDs for single type
  bpf: Fix a task_iter bug caused by a merge conflict resolution
  selftests/bpf: Fix a compile error for BPF_F_BPRM_SECUREEXEC
====================

Link: https://lore.kernel.org/r/20210107221555.64959-1-alexei.starovoitov@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-07 15:10:27 -08:00
Paul E. McKenney 1afb95fee0 torture: Maintain torture-specific set of CPUs-online books
The TREE01 rcutorture scenario intentionally creates confusion as to the
number of available CPUs by specifying the "maxcpus=8 nr_cpus=43" kernel
boot parameters.  This can disable rcutorture's load shedding, which
currently uses num_online_cpus(), which would count the extra 35 CPUs.
However, the rcutorture guest OS will be provisioned with only 8 CPUs,
which means that rcutorture will present full load even when all but one
of the original 8 CPUs are offline.  This can result in spurious errors
due to extreme overloading of that single remaining CPU.

This commit therefore keeps a separate set of books on the number of
usable online CPUs, so that torture_num_online_cpus() is used for load
shedding instead of num_online_cpus().  Note that initial sizing must
use num_online_cpus() because torture_num_online_cpus() will return
NR_CPUS until shortly after torture_onoff_init() is invoked.

Reported-by: Frederic Weisbecker <frederic@kernel.org>
[ paulmck: Apply feedback from kernel test robot. ]
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-06 17:17:22 -08:00
Paul E. McKenney 0b962c8fe0 torture: Clean up after torture-test CPU hotplugging
This commit puts all CPUs back online at the end of a torture test,
and also unconditionally puts them online at the beginning of the test,
rather than just in the case of built-in tests.  This allows torture tests
to behave in a predictable manner, whether built-in or based on modules.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-06 17:17:22 -08:00
Paul E. McKenney edf7b84178 rcutorture: Make object_debug also double call_rcu() heap object
This commit provides a test for call_rcu() printing the allocation address
of a double-freed callback by double-freeing a callback allocated via
kmalloc().  However, this commit does not depend on any other commit.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-06 17:17:21 -08:00
Paul E. McKenney 8a67a20bf2 torture: Throttle VERBOSE_TOROUT_*() output
This commit adds kernel boot parameters torture.verbose_sleep_frequency
and torture.verbose_sleep_duration, which allow VERBOSE_TOROUT_*() output
to be throttled with periodic sleeps on large systems.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-06 17:17:21 -08:00
Paul E. McKenney 414c116e01 torture: Make refscale throttle high-rate printk()s
This commit adds a short delay for verbose_batched-throttled printk()s
to further decrease console flooding.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-06 17:17:20 -08:00
Paul E. McKenney 1eba0ef981 rcutorture: Use hrtimers for reader and writer delays
This commit replaces schedule_timeout_uninterruptible() and
schedule_timeout_interruptible() with torture_hrtimeout_us() and
torture_hrtimeout_jiffies() to avoid timer-wheel synchronization.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-06 17:17:20 -08:00
Paul E. McKenney ed24affa71 torture: Make stutter use torture_hrtimeout_*() functions
This commit saves a few lines of code by making the stutter_wait()
and torture_stutter() functions use torture_hrtimeout_jiffies() and
torture_hrtimeout_us().

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-06 17:17:20 -08:00
Paul E. McKenney ea31fd9ca8 rcutorture: Use torture_hrtimeout_jiffies() to avoid busy-waits
Because rcu_torture_writer() and rcu_torture_fakewriter() predate
hrtimers, they do timer-wheel-decoupled timed waits by using the
timer-wheel-based schedule_timeout_interruptible() functions in
conjunction with a random udelay()-based wait.  This latter unnecessarily
burns CPU time, so this commit instead uses torture_hrtimeout_jiffies()
to decouple from the timer wheels without busy-waiting.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-06 17:17:19 -08:00
Paul E. McKenney ae19aaafae torture: Add fuzzed hrtimer-based sleep functions
This commit adds torture_hrtimeout_ns(), torture_hrtimeout_us(),
torture_hrtimeout_ms(), torture_hrtimeout_jiffies(), and
torture_hrtimeout_s(), each of which uses hrtimers to block for a fuzzed
time interval.  These functions are intended to be used by the various
torture tests to decouple wakeups from the timer wheel, thus providing
more opportunity for Murphy to insert destructive race conditions.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-06 17:17:19 -08:00
Paul E. McKenney 682189a3f8 rcutorture: Make rcu_torture_fakewriter() use blocking wait primitives
Full testing of the new SRCU polling API requires that the fake
writers also use it in order to test concurrent calls to all of the API
members, especially start_poll_synchronize_srcu().  This commit makes
rcu_torture_fakewriter() use all available blocking grace-period-wait
primitives available from the RCU flavor under test.

Link: https://lore.kernel.org/rcu/20201112201547.GF3365678@moria.home.lan/
Reported-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-06 17:17:18 -08:00
Paul E. McKenney 18fbf307b7 rcutorture: Make synctype[] and nsynctype be static global
Full testing of the new SRCU polling API requires that the fake writers
also use it in order to test concurrent calls to all of the API members,
especially start_poll_synchronize_srcu().  This commit prepares the ground
for this by making the synctype[] and nsynctype variables be static
globals so that the rcu_torture_fakewriter() function can access them.
Initialization of these variables is moved from rcu_torture_writer()
to a new rcu_torture_write_types() function that is invoked from
rcu_torture_init() just before the first writer kthread is spawned.

Link: https://lore.kernel.org/rcu/20201112201547.GF3365678@moria.home.lan/
Reported-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-06 17:17:10 -08:00
Paul E. McKenney 12a910e3cd rcutorture: Require entire stutter period be post-boot
Currently, the rcu_torture_writer() function checks that all required
grace periods elapse during a stutter interval, which is a multi-second
time period during which the test load is removed.  However, this check
is suppressed during early boot (that is, before init is spawned) in
order to avoid false positives that otherwise occur due to heavy load
on the single boot CPU.

Unfortunately, this approach is insufficient.  It is possible that the
stutter interval might end just as init is spawned, so that early boot
conditions prevailed during almost the entire stutter interval.

This commit therefore takes a snapshot of boot-complete state just
before the stutter interval, thus suppressing the check for failure to
complete grace periods unless the entire stutter interval took place
after early boot.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-06 17:08:12 -08:00
Paul E. McKenney e76506f0e8 refscale: Allow summarization of verbose output
The refscale test prints enough per-kthread console output to provoke RCU
CPU stall warnings on large systems.  This commit therefore allows this
output to be summarized.  For example, the refscale.verbose_batched=32
boot parameter would causes only every 32nd line of output to be logged.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-06 17:08:09 -08:00
Neeraj Upadhyay 683954e55c rcu: Check and report missed fqs timer wakeup on RCU stall
For a new grace period request, the RCU GP kthread transitions through
following states:

a. [RCU_GP_WAIT_GPS] -> [RCU_GP_DONE_GPS]

The RCU_GP_WAIT_GPS state is where the GP kthread waits for a request
for a new GP.  Once it receives a request (for example, when a new RCU
callback is queued), the GP kthread transitions to RCU_GP_DONE_GPS.

b. [RCU_GP_DONE_GPS] -> [RCU_GP_ONOFF]

Grace period initialization starts in rcu_gp_init(), which records the
start of new GP in rcu_state.gp_seq and transitions to RCU_GP_ONOFF.

c. [RCU_GP_ONOFF] -> [RCU_GP_INIT]

The purpose of the RCU_GP_ONOFF state is to apply the online/offline
information that was buffered for any CPUs that recently came online or
went offline.  This state is maintained in per-leaf rcu_node bitmasks,
with the buffered state in ->qsmaskinitnext and the state for the upcoming
GP in ->qsmaskinit.  At the end of this RCU_GP_ONOFF state, each bit in
->qsmaskinit will correspond to a CPU that must pass through a quiescent
state before the upcoming grace period is allowed to complete.

However, a leaf rcu_node structure with an all-zeroes ->qsmaskinit
cannot necessarily be ignored.  In preemptible RCU, there might well be
tasks still in RCU read-side critical sections that were first preempted
while running on one of the CPUs managed by this structure.  Such tasks
will be queued on this structure's ->blkd_tasks list.  Only after this
list fully drains can this leaf rcu_node structure be ignored, and even
then only if none of its CPUs have come back online in the meantime.
Once that happens, the ->qsmaskinit masks further up the tree will be
updated to exclude this leaf rcu_node structure.

Once the ->qsmaskinitnext and ->qsmaskinit fields have been updated
as needed, the GP kthread transitions to RCU_GP_INIT.

d. [RCU_GP_INIT] -> [RCU_GP_WAIT_FQS]

The purpose of the RCU_GP_INIT state is to copy each ->qsmaskinit to
the ->qsmask field within each rcu_node structure.  This copying is done
breadth-first from the root to the leaves.  Why not just copy directly
from ->qsmaskinitnext to ->qsmask?  Because the ->qsmaskinitnext masks
can change in the meantime as additional CPUs come online or go offline.
Such changes would result in inconsistencies in the ->qsmask fields up and
down the tree, which could in turn result in too-short grace periods or
grace-period hangs.  These issues are avoided by snapshotting the leaf
rcu_node structures' ->qsmaskinitnext fields into their ->qsmaskinit
counterparts, generating a consistent set of ->qsmaskinit fields
throughout the tree, and only then copying these consistent ->qsmaskinit
fields to their ->qsmask counterparts.

Once this initialization step is complete, the GP kthread transitions
to RCU_GP_WAIT_FQS, where it waits to do a force-quiescent-state scan
on the one hand or for the end of the grace period on the other.

e. [RCU_GP_WAIT_FQS] -> [RCU_GP_DOING_FQS]

The RCU_GP_WAIT_FQS state waits for one of three things:  (1) An
explicit request to do a force-quiescent-state scan, (2) The end of
the grace period, or (3) A short interval of time, after which it
will do a force-quiescent-state (FQS) scan.  The explicit request can
come from rcutorture or from any CPU that has too many RCU callbacks
queued (see the qhimark kernel parameter and the RCU_GP_FLAG_OVLD
flag).  The aforementioned "short period of time" is specified by the
jiffies_till_first_fqs boot parameter for a given grace period's first
FQS scan and by the jiffies_till_next_fqs for later FQS scans.

Either way, once the wait is over, the GP kthread transitions to
RCU_GP_DOING_FQS.

f. [RCU_GP_DOING_FQS] -> [RCU_GP_CLEANUP]

The RCU_GP_DOING_FQS state performs an FQS scan.  Each such scan carries
out two functions for any CPU whose bit is still set in its leaf rcu_node
structure's ->qsmask field, that is, for any CPU that has not yet reported
a quiescent state for the current grace period:

  i.  Report quiescent states on behalf of CPUs that have been observed
      to be idle (from an RCU perspective) since the beginning of the
      grace period.

  ii. If the current grace period is too old, take various actions to
      encourage holdout CPUs to pass through quiescent states, including
      enlisting the aid of any calls to cond_resched() and might_sleep(),
      and even including IPIing the holdout CPUs.

These checks are skipped for any leaf rcu_node structure with a all-zero
->qsmask field, however such structures are subject to RCU priority
boosting if there are tasks on a given structure blocking the current
grace period.  The end of the grace period is detected when the root
rcu_node structure's ->qsmask is zero and when there are no longer any
preempted tasks blocking the current grace period.  (No, this last check
is not redundant.  To see this, consider an rcu_node tree having exactly
one structure that serves as both root and leaf.)

Once the end of the grace period is detected, the GP kthread transitions
to RCU_GP_CLEANUP.

g. [RCU_GP_CLEANUP] -> [RCU_GP_CLEANED]

The RCU_GP_CLEANUP state marks the end of grace period by updating the
rcu_state structure's ->gp_seq field and also all rcu_node structures'
->gp_seq field.  As before, the rcu_node tree is traversed in breadth
first order.  Once this update is complete, the GP kthread transitions
to the RCU_GP_CLEANED state.

i. [RCU_GP_CLEANED] -> [RCU_GP_INIT]

Once in the RCU_GP_CLEANED state, the GP kthread immediately transitions
into the RCU_GP_INIT state.

j. The role of timers.

If there is at least one idle CPU, and if timers are not firing, the
transition from RCU_GP_DOING_FQS to RCU_GP_CLEANUP will never happen.
Timers can fail to fire for a number of reasons, including issues in
timer configuration, issues in the timer framework, and failure to handle
softirqs (for example, when there is a storm of interrupts).  Whatever the
reason, if the timers fail to fire, the GP kthread will never be awakened,
resulting in RCU CPU stall warnings and eventually in OOM.

However, an RCU CPU stall warning has a large number of potential causes,
as documented in Documentation/RCU/stallwarn.rst.  This commit therefore
adds analysis to the RCU CPU stall-warning code to emit an additional
message if the cause of the stall is likely to be timer failure.

Signed-off-by: Neeraj Upadhyay <neeraju@codeaurora.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-06 16:54:11 -08:00
Paul E. McKenney 147c6852d3 rcu: Do any deferred nocb wakeups at CPU offline time
Because the need to wake a nocb GP kthread ("rcuog") is sometimes
detected when wakeups cannot be done, these wakeups can be deferred.
The wakeups are then carried out by calls to do_nocb_deferred_wakeup()
at various safe points in the code, including RCU's idle hooks.  However,
when a CPU goes offline, it invokes arch_cpu_idle_dead() without invoking
any of RCU's idle hooks.

This commit therefore adds a call to do_nocb_deferred_wakeup() in
rcu_report_dead() in order to handle any deferred wakeups that have been
requested by the outgoing CPU.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-06 16:50:24 -08:00
Paul E. McKenney f759081e8f rcu/nocb: Code-style nits in callback-offloading toggling
This commit addresses a few code-style nits in callback-offloading
toggling, including one that predates this toggling.

Cc: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-06 16:47:55 -08:00
Paul E. McKenney 3d0cef50f3 rcu/nocb: Add nocb CB kthread list to show_rcu_nocb_state() output
This commit improves debuggability by indicating laying out the order
in which rcuoc kthreads appear in the ->nocb_next_cb_rdp list.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-06 16:25:00 -08:00
Paul E. McKenney 341690611f rcu/nocb: Add grace period and task state to show_rcu_nocb_state() output
This commit improves debuggability by indicating which grace period each
batch of nocb callbacks is waiting on and by showing the task state and
last CPU for reach nocb kthread.

[ paulmck: Handle !SMP CB offloading per kernel test robot feedback. ]
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-06 16:25:00 -08:00
Paul E. McKenney 2c4319bd1d rcutorture: Test runtime toggling of CPUs' callback offloading
Frederic Weisbecker is adding the ability to change the rcu_nocbs state
of CPUs at runtime, that is, to offload and deoffload their RCU callback
processing without the need to reboot.  As the old saying goes, "if it
ain't tested, it don't work", so this commit therefore adds prototype
rcutorture testing for this capability.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Frederic Weisbecker <frederic@kernel.org>
2021-01-06 16:24:59 -08:00
Frederic Weisbecker dcd42591eb timer: Add timer_curr_running()
This commit adds a timer_curr_running() function that verifies that the
current code is running in the context of the specified timer's handler.

Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Neeraj Upadhyay <neeraju@codeaurora.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-06 16:24:59 -08:00
Frederic Weisbecker 43759fe5a1 cpu/hotplug: Add lockdep_is_cpus_held()
This commit adds a lockdep_is_cpus_held() function to verify that the
proper locks are held and that various operations are running in the
correct context.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Neeraj Upadhyay <neeraju@codeaurora.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-06 16:24:59 -08:00
Frederic Weisbecker 634954c2db rcu/nocb: Locally accelerate callbacks as long as offloading isn't complete
The local callbacks processing checks if any callbacks need acceleration.
This commit carries out this checking under nocb lock protection in
the middle of toggle operations, during which time rcu_core() executes
concurrently with GP/CB kthreads.

Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Neeraj Upadhyay <neeraju@codeaurora.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Inspired-by: Paul E. McKenney <paulmck@kernel.org>
Tested-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-06 16:24:59 -08:00
Frederic Weisbecker 32aa2f4170 rcu/nocb: Process batch locally as long as offloading isn't complete
This commit makes sure to process the callbacks locally (via either
RCU_SOFTIRQ or the rcuc kthread) whenever the segcblist isn't entirely
offloaded.  This ensures that callbacks are invoked one way or another
while a CPU is in the middle of a toggle operation.

Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Neeraj Upadhyay <neeraju@codeaurora.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Inspired-by: Paul E. McKenney <paulmck@kernel.org>
Tested-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-06 16:24:59 -08:00
Frederic Weisbecker e3abe959fb rcu/nocb: Only cond_resched() from actual offloaded batch processing
During a toggle operations, rcu_do_batch() may be invoked concurrently
by softirqs and offloaded processing for a given CPU's callbacks.
This commit therefore makes sure cond_resched() is invoked only from
the offloaded context.

Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Neeraj Upadhyay <neeraju@codeaurora.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Inspired-by: Paul E. McKenney <paulmck@kernel.org>
Tested-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-06 16:24:59 -08:00
Frederic Weisbecker b9ced9e1ab rcu/nocb: Set SEGCBLIST_SOFTIRQ_ONLY at the very last stage of de-offloading
This commit sets SEGCBLIST_SOFTIRQ_ONLY once toggling is otherwise fully
complete, allowing further RCU callback manipulation to be carried out
locklessly and locally.

Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Neeraj Upadhyay <neeraju@codeaurora.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Inspired-by: Paul E. McKenney <paulmck@kernel.org>
Tested-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-06 16:24:59 -08:00
Frederic Weisbecker 314202f84d rcu/nocb: Flush bypass before setting SEGCBLIST_SOFTIRQ_ONLY
This commit flushes the bypass queue and sets state to avoid its being
refilled before switching to the final de-offloaded state.  To avoid
refilling, this commit sets SEGCBLIST_SOFTIRQ_ONLY before re-enabling
IRQs.

Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Neeraj Upadhyay <neeraju@codeaurora.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Inspired-by: Paul E. McKenney <paulmck@kernel.org>
Tested-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-06 16:24:59 -08:00
Frederic Weisbecker 69cdea873c rcu/nocb: Shutdown nocb timer on de-offloading
This commit ensures that the nocb timer is shut down before reaching the
final de-offloaded state.  The key goal is to prevent the timer handler
from manipulating the callbacks without the protection of the nocb locks.

Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Neeraj Upadhyay <neeraju@codeaurora.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Inspired-by: Paul E. McKenney <paulmck@kernel.org>
Tested-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-06 16:24:59 -08:00
Frederic Weisbecker 254e11efde rcu/nocb: Re-offload support
To re-offload the callback processing off of a CPU, it is necessary to
clear SEGCBLIST_SOFTIRQ_ONLY, set SEGCBLIST_OFFLOADED, and then notify
both the CB and GP kthreads so that they both set their own bit flag and
start processing the callbacks remotely.  The re-offloading worker is
then notified that it can stop the RCU_SOFTIRQ handler (or rcuc kthread,
as the case may be) from processing the callbacks locally.

Ordering must be carefully enforced so that the callbacks that used to be
processed locally without locking will have the same ordering properties
when they are invoked by the nocb CB and GP kthreads.

This commit makes this change.

Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Neeraj Upadhyay <neeraju@codeaurora.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Inspired-by: Paul E. McKenney <paulmck@kernel.org>
Tested-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
[ paulmck: Export rcu_nocb_cpu_offload(). ]
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-06 16:24:25 -08:00
Frederic Weisbecker 5bb39dc956 rcu/nocb: De-offloading GP kthread
To de-offload callback processing back onto a CPU, it is necessary
to clear SEGCBLIST_OFFLOAD and notify the nocb GP kthread, which will
then clear its own bit flag and ignore this CPU until further notice.
Whichever of the nocb CB and nocb GP kthreads is last to clear its own
bit notifies the de-offloading worker kthread.  Once notified, this
worker kthread can proceed safe in the knowledge that the nocb CB and
GP kthreads will no longer be manipulating this CPU's RCU callback list.

This commit makes this change.

Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Neeraj Upadhyay <neeraju@codeaurora.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Inspired-by: Paul E. McKenney <paulmck@kernel.org>
Tested-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-06 16:24:20 -08:00
Frederic Weisbecker ef005345e6 rcu/nocb: Don't deoffload an offline CPU with pending work
Offloaded CPUs do not migrate their callbacks, instead relying on
their rcuo kthread to invoke them.  But if the CPU is offline, it
will be running neither its RCU_SOFTIRQ handler nor its rcuc kthread.
This means that de-offloading an offline CPU that still has pending
callbacks will strand those callbacks.  This commit therefore refuses
to toggle offline CPUs having pending callbacks.

Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Neeraj Upadhyay <neeraju@codeaurora.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Suggested-by: Paul E. McKenney <paulmck@kernel.org>
Tested-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-06 16:24:19 -08:00
Frederic Weisbecker d97b078182 rcu/nocb: De-offloading CB kthread
To de-offload callback processing back onto a CPU, it is necessary to
clear SEGCBLIST_OFFLOAD and notify the nocb CB kthread, which will then
clear its own bit flag and go to sleep to stop handling callbacks.  This
commit makes that change.  It will also be necessary to notify the nocb
GP kthread in this same way, which is the subject of a follow-on commit.

Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Neeraj Upadhyay <neeraju@codeaurora.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Inspired-by: Paul E. McKenney <paulmck@kernel.org>
Tested-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
[ paulmck: Add export per kernel test robot feedback. ]
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-06 16:24:19 -08:00
Frederic Weisbecker 126d9d4952 rcu/nocb: Always init segcblist on CPU up
How the rdp->cblist enabled state is treated at CPU-hotplug time depends
on whether or not that ->cblist is offloaded.

1) Not offloaded: The ->cblist is disabled when the CPU goes down. All
   its callbacks are migrated and none can to enqueued until after some
   later CPU-hotplug operation brings the CPU back up.

2) Offloaded: The ->cblist is not disabled on CPU down because the CB/GP
   kthreads must finish invoking the remaining callbacks. There is thus
   no need to re-enable it on CPU up.

Since the ->cblist offloaded state is set in stone at boot, it cannot
change between CPU down and CPU up. So 1) and 2) are symmetrical.

However, given runtime toggling of the offloaded state, there are two
additional asymmetrical scenarios:

3) The ->cblist is not offloaded when the CPU goes down. The ->cblist
   is later toggled to offloaded and then the CPU comes back up.

4) The ->cblist is offloaded when the CPU goes down. The ->cblist is
   later toggled to no longer be offloaded and then the CPU comes back up.

Scenario 4) is currently handled correctly. The ->cblist remains enabled
on CPU down and gets re-initialized on CPU up. The toggling operation
will wait until ->cblist is empty, so ->cblist will remain empty until
CPU-up time.

The scenario 3) would run into trouble though, as the rdp is disabled
on CPU down and not re-initialized/re-enabled on CPU up.  Except that
in this case, ->cblist is guaranteed to be empty because all its
callbacks were migrated away at CPU-down time.  And the CPU-up code
already initializes and enables any empty ->cblist structures in order
to handle the possibility of early-boot invocations of call_rcu() in
the case where such invocations don't occur.  So all that need be done
is to adjust the locking.

Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Neeraj Upadhyay <neeraju@codeaurora.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Inspired-by: Paul E. McKenney <paulmck@kernel.org>
Tested-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-06 16:24:19 -08:00
Frederic Weisbecker 8d346d438f rcu/nocb: Provide basic callback offloading state machine bits
Offloading and de-offloading RCU callback processes must be done
carefully.  There must never be a time at which callback processing is
disabled because the task driving the offloading or de-offloading might be
preempted or otherwise stalled at that point in time, which would result
in OOM due to calbacks piling up indefinitely.  This implies that there
will be times during which a given CPU's callbacks might be concurrently
invoked by both that CPU's RCU_SOFTIRQ handler (or, equivalently, that
CPU's rcuc kthread) and by that CPU's rcuo kthread.

This situation could fatally confuse both rcu_barrier() and the
CPU-hotplug offlining process, so these must be excluded during any
concurrent-callback-invocation period.  In addition, during times of
concurrent callback invocation, changes to ->cblist must be protected
both as needed for RCU_SOFTIRQ and as needed for the rcuo kthread.

This commit therefore defines and documents the states for a state
machine that coordinates offloading and deoffloading.

Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Neeraj Upadhyay <neeraju@codeaurora.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Inspired-by: Paul E. McKenney <paulmck@kernel.org>
Tested-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-06 16:24:19 -08:00
Frederic Weisbecker 65e560327f rcu/nocb: Turn enabled/offload states into a common flag
This commit gathers the rcu_segcblist ->enabled and ->offloaded property
field into a single ->flags bitmask to avoid further proliferation of
individual u8 fields in the structure.  This change prepares for the
state formerly known as ->offloaded state to be modified at runtime.

Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Neeraj Upadhyay <neeraju@codeaurora.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Inspired-by: Paul E. McKenney <paulmck@kernel.org>
Tested-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-06 16:24:19 -08:00
Joel Fernandes (Google) b4e6039e8a rcu/segcblist: Add debug checks for segment lengths
This commit adds debug checks near the end of rcu_do_batch() that emit
warnings if an empty rcu_segcblist structure has non-zero segment counts,
or, conversely, if a non-empty structure has all-zero segment counts.

Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
[ paulmck: Fix queue/segment-length checks. ]
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-06 16:24:19 -08:00
Joel Fernandes (Google) 3afe7fa535 rcu/trace: Add tracing for how segcb list changes
This commit adds tracing to track how the segcb list changes before/after
acceleration, during queuing and during dequeuing.

This tracing helped discover an optimization that avoided needless GP
requests when no callbacks were accelerated. The tracing overhead is
minimal as each segment's length is now stored in the respective segment.

Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Reviewed-by: Neeraj Upadhyay <neeraju@codeaurora.org>
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-06 16:24:19 -08:00
Joel Fernandes (Google) 68804cf1c9 rcu/tree: segcblist: Remove redundant smp_mb()s
The full memory barriers in rcu_segcblist_enqueue() and in rcu_do_batch()
are not needed because rcu_segcblist_add_len(), and thus also
rcu_segcblist_inc_len(), already includes a memory barrier *before*
and *after* the length of the list is updated.

This commit therefore removes these redundant smp_mb() invocations.

Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-06 16:24:19 -08:00
Joel Fernandes (Google) ae5c2341ed rcu/segcblist: Add counters to segcblist datastructure
Add counting of segment lengths of segmented callback list.

This will be useful for a number of things such as knowing how big the
ready-to-execute segment have gotten. The immediate benefit is ability
to trace how the callbacks in the segmented callback list change.

Also this patch remove hacks related to using donecbs's ->len field as a
temporary variable to save the segmented callback list's length. This cannot be
done anymore and is not needed.

Also fix SRCU:
The negative counting of the unsegmented list cannot be used to adjust
the segmented one. To fix this, sample the unsegmented length in
advance, and use it after CB execution to adjust the segmented list's
length.

Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-06 16:24:19 -08:00
Joel Fernandes (Google) c2e13112e8 rcu/segcblist: Add additional comments to explain smp_mb()
One counter-intuitive property of RCU is the fact that full memory
barriers are needed both before and after updates to the full
(non-segmented) length.  This patch therefore helps to assist the
reader's intuition by adding appropriate comments.

[ paulmck:  Wordsmithing. ]
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-06 16:23:23 -08:00
Matthias Maennich 00b8c557d0 staging: ION: remove some references to CONFIG_ION
With commit e722a295cf ("staging: ion: remove from the tree"), ION and
its corresponding config CONFIG_ION is gone. Remove stale references
from drivers/staging/media/atomisp/pci and from the recommended Android
kernel config.

Fixes: e722a295cf ("staging: ion: remove from the tree")
Cc: Hridya Valsaraju <hridya@google.com>
Cc: Rob Herring <robh@kernel.org>
Cc: linux-media@vger.kernel.org
Cc: devel@driverdev.osuosl.org
Signed-off-by: Matthias Maennich <maennich@google.com>
Link: https://lore.kernel.org/r/20210106155201.2845319-1-maennich@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-06 17:39:38 +01:00
Al Viro f2485a2dc9 elf_prstatus: collect the common part (everything before pr_reg) into a struct
Preparations to doing i386 compat elf_prstatus sanely - rather than duplicating
the beginning of compat_elf_prstatus, take these fields into a separate
structure (compat_elf_prstatus_common), so that it could be reused.  Due to
the incestous relationship between binfmt_elf.c and compat_binfmt_elf.c we
need the same shape change done to native struct elf_prstatus, gathering the
fields prior to pr_reg into a new structure (struct elf_prstatus_common).

Fortunately, offset of pr_reg is always a multiple of 16 with no padding
right before it, so it's possible to turn all the stuff prior to it into
a single member without disturbing the layout.

[build fix from Geert Uytterhoeven folded in]

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2021-01-06 08:38:29 -05:00
Linus Torvalds aa35e45cd4 Networking fixes for 5.11-rc3, including fixes from netfilter, wireless
and bpf trees.
 
 Current release - regressions:
 
  - mt76: - usb: fix NULL pointer dereference in mt76u_status_worker
          - sdio: fix NULL pointer dereference in mt76s_process_tx_queue
 
  - net: ipa: fix interconnect enable bug
 
 Current release - always broken:
 
  - netfilter: ipset: fixes possible oops in mtype_resize
 
  - ath11k: fix number of coding issues found by static analysis tools
            and spurious error messages
 
 Previous releases - regressions:
 
  - e1000e: re-enable s0ix power saving flows for systems with
            the Intel i219-LM Ethernet controllers to fix power
 	   use regression
 
  - virtio_net: fix recursive call to cpus_read_lock() to avoid
                a deadlock
 
  - ipv4: ignore ECN bits for fib lookups in fib_compute_spec_dst()
 
  - net-sysfs: take the rtnl lock around XPS configuration
 
  - xsk: - fix memory leak for failed bind
         - rollback reservation at NETDEV_TX_BUSY
 
  - r8169: work around power-saving bug on some chip versions
 
 Previous releases - always broken:
 
  - dcb: validate netlink message in DCB handler
 
  - tun: fix return value when the number of iovs exceeds MAX_SKB_FRAGS
         to prevent unnecessary retries
 
  - vhost_net: fix ubuf refcount when sendmsg fails
 
  - bpf: save correct stopping point in file seq iteration
 
  - ncsi: use real net-device for response handler
 
  - neighbor: fix div by zero caused by a data race (TOCTOU)
 
  - bareudp: - fix use of incorrect min_headroom size
             - fix false positive lockdep splat from the TX lock
 
  - net: mvpp2: - clear force link UP during port init procedure
                  in case bootloader had set it
                - add TCAM entry to drop flow control pause frames
 	       - fix PPPoE with ipv6 packet parsing
 	       - fix GoP Networking Complex Control config of port 3
 	       - fix pkt coalescing IRQ-threshold configuration
 
  - xsk: fix race in SKB mode transmit with shared cq
 
  - ionic: account for vlan tag len in rx buffer len
 
  - net: stmmac: ignore the second clock input, current clock framework
                 does not handle exclusive clock use well, other drivers
 		may reconfigure the second clock
 Misc:
 
  - ppp: change PPPIOCUNBRIDGECHAN ioctl request number to follow
         existing scheme
 
 Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Merge tag 'net-5.11-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

Pull networking fixes from Jakub Kicinski:
 "Networking fixes, including fixes from netfilter, wireless and bpf
  trees.

  Current release - regressions:

   - mt76: fix NULL pointer dereference in mt76u_status_worker and
     mt76s_process_tx_queue

   - net: ipa: fix interconnect enable bug

  Current release - always broken:

   - netfilter: fixes possible oops in mtype_resize in ipset

   - ath11k: fix number of coding issues found by static analysis tools
     and spurious error messages

  Previous releases - regressions:

   - e1000e: re-enable s0ix power saving flows for systems with the
     Intel i219-LM Ethernet controllers to fix power use regression

   - virtio_net: fix recursive call to cpus_read_lock() to avoid a
     deadlock

   - ipv4: ignore ECN bits for fib lookups in fib_compute_spec_dst()

   - sysfs: take the rtnl lock around XPS configuration

   - xsk: fix memory leak for failed bind and rollback reservation at
     NETDEV_TX_BUSY

   - r8169: work around power-saving bug on some chip versions

  Previous releases - always broken:

   - dcb: validate netlink message in DCB handler

   - tun: fix return value when the number of iovs exceeds MAX_SKB_FRAGS
     to prevent unnecessary retries

   - vhost_net: fix ubuf refcount when sendmsg fails

   - bpf: save correct stopping point in file seq iteration

   - ncsi: use real net-device for response handler

   - neighbor: fix div by zero caused by a data race (TOCTOU)

   - bareudp: fix use of incorrect min_headroom size and a false
     positive lockdep splat from the TX lock

   - mvpp2:
      - clear force link UP during port init procedure in case
        bootloader had set it
      - add TCAM entry to drop flow control pause frames
      - fix PPPoE with ipv6 packet parsing
      - fix GoP Networking Complex Control config of port 3
      - fix pkt coalescing IRQ-threshold configuration

   - xsk: fix race in SKB mode transmit with shared cq

   - ionic: account for vlan tag len in rx buffer len

   - stmmac: ignore the second clock input, current clock framework does
     not handle exclusive clock use well, other drivers may reconfigure
     the second clock

  Misc:

   - ppp: change PPPIOCUNBRIDGECHAN ioctl request number to follow
     existing scheme"

* tag 'net-5.11-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (99 commits)
  net: dsa: lantiq_gswip: Fix GSWIP_MII_CFG(p) register access
  net: dsa: lantiq_gswip: Enable GSWIP_MII_CFG_EN also for internal PHYs
  net: lapb: Decrease the refcount of "struct lapb_cb" in lapb_device_event
  r8169: work around power-saving bug on some chip versions
  net: usb: qmi_wwan: add Quectel EM160R-GL
  selftests: mlxsw: Set headroom size of correct port
  net: macb: Correct usage of MACB_CAPS_CLK_HW_CHG flag
  ibmvnic: fix: NULL pointer dereference.
  docs: networking: packet_mmap: fix old config reference
  docs: networking: packet_mmap: fix formatting for C macros
  vhost_net: fix ubuf refcount incorrectly when sendmsg fails
  bareudp: Fix use of incorrect min_headroom size
  bareudp: set NETIF_F_LLTX flag
  net: hdlc_ppp: Fix issues when mod_timer is called while timer is running
  atlantic: remove architecture depends
  erspan: fix version 1 check in gre_parse_header()
  net: hns: fix return value check in __lb_other_process()
  net: sched: prevent invalid Scell_log shift count
  net: neighbor: fix a crash caused by mod zero
  ipv4: Ignore ECN bits for fib lookups in fib_compute_spec_dst()
  ...
2021-01-05 12:38:56 -08:00
Zheng Yongjun a1b861faa6 kernel/audit: convert comma to semicolon
Replace a comma between expression statements by a semicolon.

Signed-off-by: Zheng Yongjun <zhengyongjun3@huawei.com>
Reviewed-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2021-01-04 19:37:35 -05:00
Paul E. McKenney c26165efac rcu: Make TASKS_TRACE_RCU select IRQ_WORK
Tasks Trace RCU uses irq_work_queue() to safely awaken its grace-period
kthread, so this commit therefore causes the TASKS_TRACE_RCU Kconfig
option select the IRQ_WORK Kconfig option.

Reported-by: kernel test robot <lkp@intel.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org> # build-tested
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-04 15:54:49 -08:00
Uladzislau Rezki (Sony) bfba7ed084 rcu-tasks: Add RCU-tasks self tests
This commit adds self tests for early-boot use of RCU-tasks grace periods.
It tests all three variants (Rude, Tasks, and Tasks Trace) and covers
both synchronous (e.g., synchronize_rcu_tasks()) and asynchronous (e.g.,
call_rcu_tasks()) grace-period APIs.

Self-tests are run only in kernels built with CONFIG_PROVE_RCU=y.

Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
[ paulmck: Handle CONFIG_PROVE_RCU=n and identify test cases' callbacks. ]
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-04 15:54:49 -08:00
Paul E. McKenney 7dffe01765 rcu: Add lockdep_assert_irqs_disabled() to raw_spin_unlock_rcu_node() macros
This commit adds a lockdep_assert_irqs_disabled() call to the
helper macros that release the rcu_node structure's ->lock, namely
to raw_spin_unlock_rcu_node(), raw_spin_unlock_irq_rcu_node() and
raw_spin_unlock_irqrestore_rcu_node().  The point of this is to help track
down a situation where lockdep appears to be insisting that interrupts
are enabled while holding an rcu_node structure's ->lock.

Link: https://lore.kernel.org/lkml/20201111133813.GA81547@elver.google.com/
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-04 15:54:49 -08:00
Paul E. McKenney a649d25dcc rcu: Add lockdep_assert_irqs_disabled() to rcu_sched_clock_irq() and callees
This commit adds a number of lockdep_assert_irqs_disabled() calls
to rcu_sched_clock_irq() and a number of the functions that it calls.
The point of this is to help track down a situation where lockdep appears
to be insisting that interrupts are enabled within these functions, which
should only ever be invoked from the scheduling-clock interrupt handler.

Link: https://lore.kernel.org/lkml/20201111133813.GA81547@elver.google.com/
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-04 15:54:49 -08:00
Wang Qing c5586e32df locking: Remove duplicate include of percpu-rwsem.h
This commit removes an unnecessary #include.

Signed-off-by: Wang Qing <wangqing@vivo.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-04 15:54:49 -08:00
Peter Zijlstra 1b7af29554 sched/core: Allow try_invoke_on_locked_down_task() with irqs disabled
The try_invoke_on_locked_down_task() function currently requires
that interrupts be enabled, but it is called with interrupts
disabled from rcu_print_task_stall(), resulting in an "IRQs not
enabled as expected" diagnostic.  This commit therefore updates
try_invoke_on_locked_down_task() to use raw_spin_lock_irqsave() instead
of raw_spin_lock_irq(), thus allowing use from either context.

Link: https://lore.kernel.org/lkml/000000000000903d5805ab908fc4@google.com/
Link: https://lore.kernel.org/lkml/20200928075729.GC2611@hirez.programming.kicks-ass.net/
Reported-by: syzbot+cb3b69ae80afd6535b0e@syzkaller.appspotmail.com
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-04 15:49:52 -08:00
Marco Elver 71a076f4a6 kcsan: Rewrite kcsan_prandom_u32_max() without prandom_u32_state()
Rewrite kcsan_prandom_u32_max() to not depend on code that might be
instrumented, removing any dependency on lib/random32.c. The rewrite
implements a simple linear congruential generator, that is sufficient
for our purposes (for udelay() and skip_watch counter randomness).

The initial motivation for this was to allow enabling KCSAN for
kernel/sched (remove KCSAN_SANITIZE := n from kernel/sched/Makefile),
with CONFIG_DEBUG_PREEMPT=y. Without this change, we could observe
recursion:

	check_access() [via instrumentation]
	  kcsan_setup_watchpoint()
	    reset_kcsan_skip()
	      kcsan_prandom_u32_max()
	        get_cpu_var()
		  preempt_disable()
		    preempt_count_add() [in kernel/sched/core.c]
		      check_access() [via instrumentation]

Note, while this currently does not affect an unmodified kernel, it'd be
good to keep a KCSAN kernel working when KCSAN_SANITIZE := n is removed
from kernel/sched/Makefile to permit testing scheduler code with KCSAN
if desired.

Fixes: cd290ec246 ("kcsan: Use tracing-safe version of prandom")
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-04 14:39:07 -08:00
Paul E. McKenney 725969ac11 rcu: Do not NMI offline CPUs
Currently, RCU CPU stall warning messages will NMI whatever CPU looks
like it is blocking either the current grace period or the grace-period
kthread.  This can produce confusing output if the target CPU is offline.
This commit therefore checks for offline CPUs.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-04 13:59:47 -08:00
Paul E. McKenney 243027a3c8 rcu: For RCU grace-period kthread starvation, dump last CPU it ran on
When the RCU CPU stall-warning code detects that the RCU grace-period
kthread is being starved, it dumps that kthread's stack.  This can
sometimes be useful, but it is also useful to know what is running on the
CPU that this kthread is attempting to run on.  This commit therefore
adds a stack trace of this CPU in order to help track down whatever it
is that might be preventing RCU's grace-period kthread from running.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-04 13:59:41 -08:00
Paul E. McKenney b08ea1de6a rcu: Mark obtuse portion of stall warning as internal debug
There is a rather obtuse string that can be printed as part of an
expedited RCU CPU stall-warning message that starts with "blocking
rcu_node structures".  Under normal conditions, most of this message
is just repeating the list of CPUs blocking the current expedited grace
period, but in a manner that is rather difficult to read.  This commit
therefore marks this message as "(internal RCU debug)" in an effort to
give people the option of avoiding wasting time attempting to extract
nonexistent additional meaning from this portion of the message.

Reported-by: Jonathan Lemon <bsd@fb.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-04 13:54:40 -08:00
Paul E. McKenney f3ea978b71 scftorture: Add debug output for wrong-CPU warning
This commit adds the desired CPU, the actual CPU, and nr_cpu_ids to
the wrong-CPU warning in scftorture_invoker(), the better to help with
debugging.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-04 13:53:41 -08:00
Paul E. McKenney 00504537f4 rcutorture: Add testing for RCU's global memory ordering
RCU guarantees that anything seen by a given reader will also be seen
after any grace period that must wait on that reader.  This is very likely
to hold based on inspection, but the advantage of having rcutorture do
the inspecting is that rcutorture doesn't mind inspecting frequently
and often.

This commit therefore adds code to test RCU's global memory ordering.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-04 13:53:41 -08:00
Paul E. McKenney bc480a6354 rcutorture: Add reader-side tests of polling grace-period API
This commit adds reader-side testing of the polling grace-period API.
This testing verifies that a cookie obtained in an SRCU read-side critical
section does not get a true return from poll_state_synchronize_srcu()
within that same critical section.

Link: https://lore.kernel.org/rcu/20201112201547.GF3365678@moria.home.lan/
Reported-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-04 13:53:40 -08:00
Paul E. McKenney 0fd0548db1 rcutorture: Add writer-side tests of polling grace-period API
This commit adds writer-side testing of the polling grace-period API.
One test verifies that the polling API sees a grace period caused by
some other mechanism.  Another test verifies that using the polling API
to wait for a grace period does not result in too-short grace periods.
A third test verifies that the polling API does not report
completion within a read-side critical section.  A fourth and final
test verifies that the polling API does report completion given an
intervening grace period.

Link: https://lore.kernel.org/rcu/20201112201547.GF3365678@moria.home.lan/
Reported-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-04 13:53:40 -08:00
Paul E. McKenney fd56f64b4e rcutorture: Prepare for ->start_gp_poll and ->poll_gp_state
The new get_state_synchronize_srcu(), start_poll_synchronize_srcu() and
poll_state_synchronize_srcu() functions need to be tested, and so this
commit prepares by renaming the rcu_torture_ops field ->get_state to
->get_gp_state in order to be consistent with the upcoming ->start_gp_poll
and ->poll_gp_state fields.

Link: https://lore.kernel.org/rcu/20201112201547.GF3365678@moria.home.lan/
Reported-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-04 13:53:39 -08:00
Paul E. McKenney 4e7ccfae52 srcu: Add comment explaining cookie overflow/wrap
This commit adds to the poll_state_synchronize_srcu() header comment
describing the issues surrounding SRCU cookie overflow/wrap for the
different kernel configurations.

Link: https://lore.kernel.org/rcu/20201112201547.GF3365678@moria.home.lan/
Reported-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-04 13:53:39 -08:00
Paul E. McKenney 5358c9fa54 srcu: Provide polling interfaces for Tree SRCU grace periods
There is a need for a polling interface for SRCU grace
periods, so this commit supplies get_state_synchronize_srcu(),
start_poll_synchronize_srcu(), and poll_state_synchronize_srcu() for this
purpose.  The first can be used if future grace periods are inevitable
(perhaps due to a later call_srcu() invocation), the second if future
grace periods might not otherwise happen, and the third to check if a
grace period has elapsed since the corresponding call to either of the
first two.

As with get_state_synchronize_rcu() and cond_synchronize_rcu(),
the return value from either get_state_synchronize_srcu() or
start_poll_synchronize_srcu() must be passed in to a later call to
poll_state_synchronize_srcu().

Link: https://lore.kernel.org/rcu/20201112201547.GF3365678@moria.home.lan/
Reported-by: Kent Overstreet <kent.overstreet@gmail.com>
[ paulmck: Add EXPORT_SYMBOL_GPL() per kernel test robot feedback. ]
[ paulmck: Apply feedback from Neeraj Upadhyay. ]
Link: https://lore.kernel.org/lkml/20201117004017.GA7444@paulmck-ThinkPad-P72/
Reviewed-by: Neeraj Upadhyay <neeraju@codeaurora.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-04 13:53:38 -08:00
Paul E. McKenney 8b5bd67cf6 srcu: Provide polling interfaces for Tiny SRCU grace periods
There is a need for a polling interface for SRCU grace
periods, so this commit supplies get_state_synchronize_srcu(),
start_poll_synchronize_srcu(), and poll_state_synchronize_srcu() for this
purpose.  The first can be used if future grace periods are inevitable
(perhaps due to a later call_srcu() invocation), the second if future
grace periods might not otherwise happen, and the third to check if a
grace period has elapsed since the corresponding call to either of the
first two.

As with get_state_synchronize_rcu() and cond_synchronize_rcu(),
the return value from either get_state_synchronize_srcu() or
start_poll_synchronize_srcu() must be passed in to a later call to
poll_state_synchronize_srcu().

Link: https://lore.kernel.org/rcu/20201112201547.GF3365678@moria.home.lan/
Reported-by: Kent Overstreet <kent.overstreet@gmail.com>
[ paulmck: Add EXPORT_SYMBOL_GPL() per kernel test robot feedback. ]
[ paulmck: Apply feedback from Neeraj Upadhyay. ]
Link: https://lore.kernel.org/lkml/20201117004017.GA7444@paulmck-ThinkPad-P72/
Reviewed-by: Neeraj Upadhyay <neeraju@codeaurora.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-04 13:53:38 -08:00
Paul E. McKenney 29d2bb94a8 srcu: Provide internal interface to start a Tree SRCU grace period
There is a need for a polling interface for SRCU grace periods.
This polling needs to initiate an SRCU grace period without having
to queue (and manage) a callback.  This commit therefore splits the
Tree SRCU __call_srcu() function into callback-initialization and
queuing/start-grace-period portions, with the latter in a new function
named srcu_gp_start_if_needed().  This function may be passed a NULL
callback pointer, in which case it will refrain from queuing anything.

Why have the new function mess with queuing?  Locking considerations,
of course!

Link: https://lore.kernel.org/rcu/20201112201547.GF3365678@moria.home.lan/
Reported-by: Kent Overstreet <kent.overstreet@gmail.com>
Reviewed-by: Neeraj Upadhyay <neeraju@codeaurora.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-04 13:53:37 -08:00
Paul E. McKenney 1a893c711a srcu: Provide internal interface to start a Tiny SRCU grace period
There is a need for a polling interface for SRCU grace periods.
This polling needs to initiate an SRCU grace period without
having to queue (and manage) a callback.  This commit therefore
splits the Tiny SRCU call_srcu() function into callback-queuing and
start-grace-period portions, with the latter in a new function named
srcu_gp_start_if_needed().

Link: https://lore.kernel.org/rcu/20201112201547.GF3365678@moria.home.lan/
Reported-by: Kent Overstreet <kent.overstreet@gmail.com>
Reviewed-by: Neeraj Upadhyay <neeraju@codeaurora.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-04 13:53:37 -08:00
Paul E. McKenney 74612a07b8 srcu: Make Tiny SRCU use multi-bit grace-period counter
There is a need for a polling interface for SRCU grace periods.  This
polling needs to distinguish between an SRCU instance being idle on the
one hand or in the middle of a grace period on the other.  This commit
therefore converts the Tiny SRCU srcu_struct structure's srcu_idx from
a defacto boolean to a free-running counter, using the bottom bit to
indicate that a grace period is in progress.  The second-from-bottom
bit is thus used as the index returned by srcu_read_lock().

Link: https://lore.kernel.org/rcu/20201112201547.GF3365678@moria.home.lan/
Reported-by: Kent Overstreet <kent.overstreet@gmail.com>
[ paulmck: Fix ->srcu_lock_nesting[] indexing per Neeraj Upadhyay. ]
Reviewed-by: Neeraj Upadhyay <neeraju@codeaurora.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-04 13:53:36 -08:00
Julia Cartwright 36221e109e rcu: Enable rcu_normal_after_boot unconditionally for RT
Expedited RCU grace periods send IPIs to all non-idle CPUs, and thus can
disrupt time-critical code in real-time applications.  However, there
is a portion of boot-time processing (presumably before any real-time
applications have started) where expedited RCU grace periods are the only
option.  And so it is that experience with the -rt patchset indicates that
PREEMPT_RT systems should always set the rcupdate.rcu_normal_after_boot
kernel boot parameter.

This commit therefore makes the post-boot application environment safe
for real-time applications by making PREEMPT_RT systems disable the
rcupdate.rcu_normal_after_boot kernel boot parameter and acting as
if this parameter had been set.  This means that post-boot calls to
synchronize_rcu_expedited() will be treated as if they were instead
calls to synchronize_rcu(), thus preventing the IPIs, and thus avoiding
disrupting real-time applications.

Suggested-by: Luiz Capitulino <lcapitulino@redhat.com>
Acked-by: Paul E. McKenney <paulmck@linux.ibm.com>
Signed-off-by: Julia Cartwright <julia@ni.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
[ paulmck: Update kernel-parameters.txt accordingly. ]
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-04 13:43:51 -08:00
Scott Wood 8b9a0ecc7e rcu: Unconditionally use rcuc threads on PREEMPT_RT
PREEMPT_RT systems have long used the rcutree.use_softirq kernel
boot parameter to avoid use of RCU_SOFTIRQ handlers, which can disrupt
real-time applications by invoking callbacks during return from interrupts
that arrived while executing time-critical code.  This kernel boot
parameter instead runs RCU core processing in an 'rcuc' kthread, thus
allowing the scheduler to do its job of avoiding disrupting time-critical
code.

This commit therefore disables the rcutree.use_softirq kernel boot
parameter on PREEMPT_RT systems, thus forcing such systems to do RCU
core processing in 'rcuc' kthreads.  This approach has long been in
use by users of the -rt patchset, and there have been no complaints.
There is therefore no way for the system administrator to override this
choice, at least without modifying and rebuilding the kernel.

Signed-off-by: Scott Wood <swood@redhat.com>
[bigeasy: Reword commit message]
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
[ paulmck: Update kernel-parameters.txt accordingly. ]
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-04 13:43:51 -08:00
Sebastian Andrzej Siewior 2341bc4a03 rcu: Make RCU_BOOST default on CONFIG_PREEMPT_RT
On PREEMPT_RT kernels, RCU callbacks are deferred to the `rcuc' kthread.
This can stall RCU grace periods due to lengthy preemption not only of RCU
readers but also of 'rcuc' kthreads, either of which prevent grace periods
from completing, which can in turn result in OOM.  Because PREEMPT_RT
kernels have more kthreads that can block grace periods, it is more
important for such kernels to enable RCU_BOOST.

This commit therefore makes RCU_BOOST the default on PREEMPT_RT.
RCU_BOOST can still be manually disabled if need be.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-04 13:43:50 -08:00
Zqiang 84109ab585 rcu: Record kvfree_call_rcu() call stack for KASAN
This commit adds a call to kasan_record_aux_stack() in kvfree_call_rcu()
in order to record the call stack of the code that caused the object
to be freed.  Please note that this function does not update the
allocated/freed state, which is important because RCU readers might
still be referencing this object.

Acked-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Signed-off-by: Zqiang <qiang.zhang@windriver.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-04 13:42:04 -08:00
Joel Fernandes (Google) 6bc3358280 rcu/tree: Make rcu_do_batch count how many callbacks were executed
The rcu_do_batch() function extracts the ready-to-invoke callbacks
from the rcu_segcblist located in the ->cblist field of the current
CPU's rcu_data structure.  These callbacks are first moved to a local
(unsegmented) rcu_cblist.  The rcu_do_batch() function then uses this
rcu_cblist's ->len field to count how many CBs it has invoked, but it
does so by counting that field down from zero.  Finally, this function
negates the value in this ->len field (resulting in a positive number)
and subtracts the result from the ->len field of the current CPU's
->cblist field.

Except that it is sometimes necessary for rcu_do_batch() to stop invoking
callbacks mid-stream, despite there being more ready to invoke, for
example, if a high-priority task wakes up.  In this case the remaining
not-yet-invoked callbacks are requeued back onto the CPU's ->cblist,
but remain in the ready-to-invoke segment of that list.  As above, the
negative of the local rcu_cblist's ->len field is still subtracted from
the ->len field of the current CPU's ->cblist field.

The design of counting down from 0 is confusing and error-prone, plus
use of a positive count will make it easier to provide a uniform and
consistent API to deal with the per-segment counts that are added
later in this series.  For example, rcu_segcblist_extract_done_cbs()
can unconditionally populate the resulting unsegmented list's ->len
field during extraction.

This commit therefore explicitly counts how many callbacks were executed
in rcu_do_batch() itself, counting up from zero, and then uses that
to update the per-CPU segcb list's ->len field, without relying on the
downcounting of rcl->len from zero.

Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Reviewed-by: Neeraj Upadhyay <neeraju@codeaurora.org>
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-04 13:22:12 -08:00
Linus Torvalds 36bbbd0e23 Merge branch 'rcu/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu
Pull RCU fix from Paul McKenney:
 "This is a fix for a regression in the v5.10 merge window, but it was
  reported quite late in the v5.10 process, plus generating and testing
  the fix took some time.

  The regression is due to commit 36dadef23f ("kprobes: Init kprobes
  in early_initcall") which on powerpc can use RCU Tasks before
  initialization, resulting in boot failures.

  The fix is straightforward, simply moving initialization of RCU Tasks
  before the early_initcall()s. The fix has been exposed to -next and
  kbuild test robot testing, and has been tested by the PowerPC guys"

* 'rcu/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu:
  rcu-tasks: Move RCU-tasks initialization to before early_initcall()
2021-01-04 10:55:19 -08:00
Yonghong Song 04901aab40 bpf: Fix a task_iter bug caused by a merge conflict resolution
Latest bpf tree has a bug for bpf_iter selftest:

  $ ./test_progs -n 4/25
  test_bpf_sk_storage_get:PASS:bpf_iter_bpf_sk_storage_helpers__open_and_load 0 nsec
  test_bpf_sk_storage_get:PASS:socket 0 nsec
  ...
  do_dummy_read:PASS:read 0 nsec
  test_bpf_sk_storage_get:FAIL:bpf_map_lookup_elem map value wasn't set correctly
                          (expected 1792, got -1, err=0)
  #4/25 bpf_sk_storage_get:FAIL
  #4 bpf_iter:FAIL
  Summary: 0/0 PASSED, 0 SKIPPED, 2 FAILED

When doing merge conflict resolution, Commit 4bfc471484 missed to
save curr_task to seq_file private data. The task pointer in seq_file
private data is passed to bpf program. This caused NULL-pointer task
passed to bpf program which will immediately return upon checking
whether task pointer is NULL.

This patch added back the assignment of curr_task to seq_file private
data and fixed the issue.

Fixes: 4bfc471484 ("Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf")
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20201231052418.577024-1-yhs@fb.com
2021-01-03 01:41:32 +01:00
Linus Torvalds dc3e24b214 io_uring-5.11-2021-01-01
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Merge tag 'io_uring-5.11-2021-01-01' of git://git.kernel.dk/linux-block

Pull io_uring fixes from Jens Axboe:
 "A few fixes that should go into 5.11, all marked for stable as well:

   - Fix issue around identity COW'ing and users that share a ring
     across processes

   - Fix a hang associated with unregistering fixed files (Pavel)

   - Move the 'process is exiting' cancelation a bit earlier, so
     task_works aren't affected by it (Pavel)"

* tag 'io_uring-5.11-2021-01-01' of git://git.kernel.dk/linux-block:
  kernel/io_uring: cancel io_uring before task works
  io_uring: fix io_sqe_files_unregister() hangs
  io_uring: add a helper for setting a ref node
  io_uring: don't assume mm is constant across submits
2021-01-01 12:29:49 -08:00
Pavel Begunkov b1b6b5a30d kernel/io_uring: cancel io_uring before task works
For cancelling io_uring requests it needs either to be able to run
currently enqueued task_works or having it shut down by that moment.
Otherwise io_uring_cancel_files() may be waiting for requests that won't
ever complete.

Go with the first way and do cancellations before setting PF_EXITING and
so before putting the task_work infrastructure into a transition state
where task_work_run() would better not be called.

Cc: stable@vger.kernel.org # 5.5+
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-30 19:36:54 -07:00
David S. Miller 4bfc471484 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Daniel Borkmann says:

====================
pull-request: bpf 2020-12-28

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

There is a small merge conflict between bpf tree commit 69ca310f34
("bpf: Save correct stopping point in file seq iteration") and net tree
commit 66ed594409 ("bpf/task_iter: In task_file_seq_get_next use
task_lookup_next_fd_rcu"). The get_files_struct() does not exist anymore
in net, so take the hunk in HEAD and add the `info->tid = curr_tid` to
the error path:

  [...]
                curr_task = task_seq_get_next(ns, &curr_tid, true);
                if (!curr_task) {
                        info->task = NULL;
                        info->tid = curr_tid;
                        return NULL;
                }

                /* set info->task and info->tid */
  [...]

We've added 10 non-merge commits during the last 9 day(s) which contain
a total of 11 files changed, 75 insertions(+), 20 deletions(-).

The main changes are:

1) Various AF_XDP fixes such as fill/completion ring leak on failed bind and
   fixing a race in skb mode's backpressure mechanism, from Magnus Karlsson.

2) Fix latency spikes on lockdep enabled kernels by adding a rescheduling
   point to BPF hashtab initialization, from Eric Dumazet.

3) Fix a splat in task iterator by saving the correct stopping point in the
   seq file iteration, from Jonathan Lemon.

4) Fix BPF maps selftest by adding retries in case hashtab returns EBUSY
   errors on update/deletes, from Andrii Nakryiko.

5) Fix BPF selftest error reporting to something more user friendly if the
   vmlinux BTF cannot be found, from Kamal Mostafa.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-12-28 15:26:11 -08:00
Linus Torvalds c76e02c59e Merge branch 'for-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
Pull workqueue update from Tejun Heo:
 "The same as the cgroup tree - one commit which was scheduled for the
  5.11 merge window.

  All the commit does is avoding spurious worker wakeups from workqueue
  allocation / config change path to help cpuisol use cases"

* 'for-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  workqueue: Kick a worker based on the actual activation of delayed works
2020-12-28 11:23:02 -08:00
Linus Torvalds 91afe604c1 Merge branch 'for-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup updates from Tejun Heo:
 "These three patches were scheduled for the merge window but I forgot
  to send them out. Sorry about that.

  None of them are significant and they fit well in a fix pull request
  too - two are cosmetic and one fixes a memory leak in the mount option
  parsing path"

* 'for-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cgroup: Fix memory leak when parsing multiple source parameters
  cgroup/cgroup.c: replace 'of->kn->priv' with of_cft()
  kernel: cgroup: Mundane spelling fixes throughout the file
2020-12-28 11:16:38 -08:00
Linus Torvalds 6be5f58215 Misc fixes/updates:
- Fix static keys usage in module __init sections
 - Add separate MAINTAINERS entry for static branches/calls
 - Fix lockdep splat with CONFIG_PREEMPTIRQ_EVENTS=y tracing
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'locking-urgent-2020-12-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull locking fixes from Ingo Molnar:
 "Misc fixes/updates:

   - Fix static keys usage in module __init sections

   - Add separate MAINTAINERS entry for static branches/calls

   - Fix lockdep splat with CONFIG_PREEMPTIRQ_EVENTS=y tracing"

* tag 'locking-urgent-2020-12-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  softirq: Avoid bad tracing / lockdep interaction
  jump_label/static_call: Add MAINTAINERS
  jump_label: Fix usage in module __init
2020-12-27 09:06:10 -08:00
Linus Torvalds 2eeefc60ad Update/fix two CPU sanity checks in the hotplug and the boot code,
and fix a typo in the Kconfig help text.
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'timers-urgent-2020-12-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull timer fixes from Ingo Molnar:
 "Update/fix two CPU sanity checks in the hotplug and the boot code, and
  fix a typo in the Kconfig help text.

  [ Context: the first two commits are the result of an ongoing
    annotation+review work of (intentional) tick_do_timer_cpu() data
    races reported by KCSAN, but the annotations aren't fully cooked
    yet ]"

* tag 'timers-urgent-2020-12-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  timekeeping: Fix spelling mistake in Kconfig "fullfill" -> "fulfill"
  tick/sched: Remove bogus boot "safety" check
  tick: Remove pointless cpu valid check in hotplug code
2020-12-27 09:03:41 -08:00
Linus Torvalds 3b80dee70e Fix a context switch performance regression.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'sched-urgent-2020-12-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler fix from Ingo Molnar:
 "Fix a context switch performance regression"

* tag 'sched-urgent-2020-12-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched: Optimize finish_lock_switch()
2020-12-27 09:00:47 -08:00
Michael Ellerman 11cc92eb74 genirq: Fix export of irq_to_desc() for powerpc KVM
Commit 64a1b95bb9 ("genirq: Restrict export of irq_to_desc()") removed
the export of irq_to_desc() unless powerpc KVM is being built, because
there is still a use of irq_to_desc() in modular code there.

However it used:

  #ifdef CONFIG_KVM_BOOK3S_64_HV

Which doesn't work when that symbol is =m, leading to a build failure:

  ERROR: modpost: "irq_to_desc" [arch/powerpc/kvm/kvm-hv.ko] undefined!

Fix it by checking for the definedness of the correct symbol which is
CONFIG_KVM_BOOK3S_64_HV_MODULE.

Fixes: 64a1b95bb9 ("genirq: Restrict export of irq_to_desc()")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-25 11:02:39 -08:00
Linus Torvalds 3913d00ac5 A treewide cleanup of interrupt descriptor (ab)use with all sorts of racy
accesses, inefficient and disfunctional code. The goal is to remove the
 export of irq_to_desc() to prevent these things from creeping up again.
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Merge tag 'irq-core-2020-12-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull irq updates from Thomas Gleixner:
 "This is the second attempt after the first one failed miserably and
  got zapped to unblock the rest of the interrupt related patches.

  A treewide cleanup of interrupt descriptor (ab)use with all sorts of
  racy accesses, inefficient and disfunctional code. The goal is to
  remove the export of irq_to_desc() to prevent these things from
  creeping up again"

* tag 'irq-core-2020-12-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (30 commits)
  genirq: Restrict export of irq_to_desc()
  xen/events: Implement irq distribution
  xen/events: Reduce irq_info:: Spurious_cnt storage size
  xen/events: Only force affinity mask for percpu interrupts
  xen/events: Use immediate affinity setting
  xen/events: Remove disfunct affinity spreading
  xen/events: Remove unused bind_evtchn_to_irq_lateeoi()
  net/mlx5: Use effective interrupt affinity
  net/mlx5: Replace irq_to_desc() abuse
  net/mlx4: Use effective interrupt affinity
  net/mlx4: Replace irq_to_desc() abuse
  PCI: mobiveil: Use irq_data_get_irq_chip_data()
  PCI: xilinx-nwl: Use irq_data_get_irq_chip_data()
  NTB/msi: Use irq_has_action()
  mfd: ab8500-debugfs: Remove the racy fiddling with irq_desc
  pinctrl: nomadik: Use irq_has_action()
  drm/i915/pmu: Replace open coded kstat_irqs() copy
  drm/i915/lpe_audio: Remove pointless irq_to_desc() usage
  s390/irq: Use irq_desc_kstat_cpu() in show_msi_interrupt()
  parisc/irq: Use irq_desc_kstat_cpu() in show_interrupts()
  ...
2020-12-24 13:50:23 -08:00
Jonathan Lemon a61daaf351 bpf: Use thread_group_leader()
Instead of directly comparing task->tgid and task->pid, use the
thread_group_leader() helper.  This helps with readability, and
there should be no functional change.

Signed-off-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20201218185032.2464558-3-jonathan.lemon@gmail.com
2020-12-24 02:04:53 +01:00
Jonathan Lemon 69ca310f34 bpf: Save correct stopping point in file seq iteration
On some systems, some variant of the following splat is
repeatedly seen.  The common factor in all traces seems
to be the entry point to task_file_seq_next().  With the
patch, all warnings go away.

    rcu: INFO: rcu_sched self-detected stall on CPU
    rcu: \x0926-....: (20992 ticks this GP) idle=d7e/1/0x4000000000000002 softirq=81556231/81556231 fqs=4876
    \x09(t=21033 jiffies g=159148529 q=223125)
    NMI backtrace for cpu 26
    CPU: 26 PID: 2015853 Comm: bpftool Kdump: loaded Not tainted 5.6.13-0_fbk4_3876_gd8d1f9bf80bb #1
    Hardware name: Quanta Twin Lakes MP/Twin Lakes Passive MP, BIOS F09_3A12 10/08/2018
    Call Trace:
     <IRQ>
     dump_stack+0x50/0x70
     nmi_cpu_backtrace.cold.6+0x13/0x50
     ? lapic_can_unplug_cpu.cold.30+0x40/0x40
     nmi_trigger_cpumask_backtrace+0xba/0xca
     rcu_dump_cpu_stacks+0x99/0xc7
     rcu_sched_clock_irq.cold.90+0x1b4/0x3aa
     ? tick_sched_do_timer+0x60/0x60
     update_process_times+0x24/0x50
     tick_sched_timer+0x37/0x70
     __hrtimer_run_queues+0xfe/0x270
     hrtimer_interrupt+0xf4/0x210
     smp_apic_timer_interrupt+0x5e/0x120
     apic_timer_interrupt+0xf/0x20
     </IRQ>
    RIP: 0010:get_pid_task+0x38/0x80
    Code: 89 f6 48 8d 44 f7 08 48 8b 00 48 85 c0 74 2b 48 83 c6 55 48 c1 e6 04 48 29 f0 74 19 48 8d 78 20 ba 01 00 00 00 f0 0f c1 50 20 <85> d2 74 27 78 11 83 c2 01 78 0c 48 83 c4 08 c3 31 c0 48 83 c4 08
    RSP: 0018:ffffc9000d293dc8 EFLAGS: 00000202 ORIG_RAX: ffffffffffffff13
    RAX: ffff888637c05600 RBX: ffffc9000d293e0c RCX: 0000000000000000
    RDX: 0000000000000001 RSI: 0000000000000550 RDI: ffff888637c05620
    RBP: ffffffff8284eb80 R08: ffff88831341d300 R09: ffff88822ffd8248
    R10: ffff88822ffd82d0 R11: 00000000003a93c0 R12: 0000000000000001
    R13: 00000000ffffffff R14: ffff88831341d300 R15: 0000000000000000
     ? find_ge_pid+0x1b/0x20
     task_seq_get_next+0x52/0xc0
     task_file_seq_get_next+0x159/0x220
     task_file_seq_next+0x4f/0xa0
     bpf_seq_read+0x159/0x390
     vfs_read+0x8a/0x140
     ksys_read+0x59/0xd0
     do_syscall_64+0x42/0x110
     entry_SYSCALL_64_after_hwframe+0x44/0xa9
    RIP: 0033:0x7f95ae73e76e
    Code: Bad RIP value.
    RSP: 002b:00007ffc02c1dbf8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
    RAX: ffffffffffffffda RBX: 000000000170faa0 RCX: 00007f95ae73e76e
    RDX: 0000000000001000 RSI: 00007ffc02c1dc30 RDI: 0000000000000007
    RBP: 00007ffc02c1ec70 R08: 0000000000000005 R09: 0000000000000006
    R10: fffffffffffff20b R11: 0000000000000246 R12: 00000000019112a0
    R13: 0000000000000000 R14: 0000000000000007 R15: 00000000004283c0

If unable to obtain the file structure for the current task,
proceed to the next task number after the one returned from
task_seq_get_next(), instead of the next task number from the
original iterator.

Also, save the stopping task number from task_seq_get_next()
on failure in case of restarts.

Fixes: eaaacd2391 ("bpf: Add task and task/file iterator targets")
Signed-off-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20201218185032.2464558-2-jonathan.lemon@gmail.com
2020-12-24 02:04:47 +01:00
Linus Torvalds 4960821a4d More power management updates for 5.11-rc1
- Rework the passive-mode "fast switch" path in the intel_pstate
    driver to allow it receive the minimum (required) and target
    (desired) performance information from the schedutil governor so
    as to avoid running some workloads too fast (Rafael Wysocki).
 
  - Make the intel_pstate driver allow the policy max limit to be
    increased after the guaranteed performance value for the given
    CPU has increased (Rafael Wysocki).
 
  - Clean up the handling of CPU coordination types in the CPPC
    cpufreq driver and make it export frequency domains information
    to user space via sysfs (Ionela Voinescu).
 
  - Fix the ACPI code handling processor objects to use a correct
    coordination type when it fails to map frequency domains and drop
    a redundant CPU map initialization from it (Ionela Voinescu, Punit
    Agrawal).
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Merge tag 'pm-5.11-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull more power management updates from Rafael Wysocki:
 "These update the CPPC cpufreq driver and intel_pstate (which involves
  updating the cpufreq core and the schedutil governor) and make
  janitorial changes in the ACPI code handling processor objects.

  Specifics:

   - Rework the passive-mode "fast switch" path in the intel_pstate
     driver to allow it receive the minimum (required) and target
     (desired) performance information from the schedutil governor so as
     to avoid running some workloads too fast (Rafael Wysocki).

   - Make the intel_pstate driver allow the policy max limit to be
     increased after the guaranteed performance value for the given CPU
     has increased (Rafael Wysocki).

   - Clean up the handling of CPU coordination types in the CPPC cpufreq
     driver and make it export frequency domains information to user
     space via sysfs (Ionela Voinescu).

   - Fix the ACPI code handling processor objects to use a correct
     coordination type when it fails to map frequency domains and drop a
     redundant CPU map initialization from it (Ionela Voinescu, Punit
     Agrawal)"

* tag 'pm-5.11-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  cpufreq: intel_pstate: Use most recent guaranteed performance values
  cpufreq: intel_pstate: Implement the ->adjust_perf() callback
  cpufreq: Add special-purpose fast-switching callback for drivers
  cpufreq: schedutil: Add util to struct sg_cpu
  cppc_cpufreq: replace per-cpu data array with a list
  cppc_cpufreq: expose information on frequency domains
  cppc_cpufreq: clarify support for coordination types
  cppc_cpufreq: use policy->cpu as driver of frequency setting
  ACPI: processor: fix NONE coordination for domain mapping failure
2020-12-22 14:12:10 -08:00
Linus Torvalds 1375b9803e Merge branch 'akpm' (patches from Andrew)
Merge KASAN updates from Andrew Morton.

This adds a new hardware tag-based mode to KASAN.  The new mode is
similar to the existing software tag-based KASAN, but relies on arm64
Memory Tagging Extension (MTE) to perform memory and pointer tagging
(instead of shadow memory and compiler instrumentation).

By Andrey Konovalov and Vincenzo Frascino.

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (60 commits)
  kasan: update documentation
  kasan, mm: allow cache merging with no metadata
  kasan: sanitize objects when metadata doesn't fit
  kasan: clarify comment in __kasan_kfree_large
  kasan: simplify assign_tag and set_tag calls
  kasan: don't round_up too much
  kasan, mm: rename kasan_poison_kfree
  kasan, mm: check kasan_enabled in annotations
  kasan: add and integrate kasan boot parameters
  kasan: inline (un)poison_range and check_invalid_free
  kasan: open-code kasan_unpoison_slab
  kasan: inline random_tag for HW_TAGS
  kasan: inline kasan_reset_tag for tag-based modes
  kasan: remove __kasan_unpoison_stack
  kasan: allow VMAP_STACK for HW_TAGS mode
  kasan, arm64: unpoison stack only with CONFIG_KASAN_STACK
  kasan: introduce set_alloc_info
  kasan: rename get_alloc/free_info
  kasan: simplify quarantine_put call site
  kselftest/arm64: check GCR_EL1 after context switch
  ...
2020-12-22 13:38:17 -08:00
Linus Torvalds 347d81b68b dma-mapping updates for 5.11:
- support for a partial IOMMU bypass (Alexey Kardashevskiy)
  - add a DMA API benchmark (Barry Song)
  - misc fixes (Tiezhu Yang, tangjianqiang)
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Merge tag 'dma-mapping-5.11' of git://git.infradead.org/users/hch/dma-mapping

Pull dma-mapping updates from Christoph Hellwig:

 - support for a partial IOMMU bypass (Alexey Kardashevskiy)

 - add a DMA API benchmark (Barry Song)

 - misc fixes (Tiezhu Yang, tangjianqiang)

* tag 'dma-mapping-5.11' of git://git.infradead.org/users/hch/dma-mapping:
  selftests/dma: add test application for DMA_MAP_BENCHMARK
  dma-mapping: add benchmark support for streaming DMA APIs
  dma-contiguous: fix a typo error in a comment
  dma-pool: no need to check return value of debugfs_create functions
  powerpc/dma: Fallback to dma_ops when persistent memory present
  dma-mapping: Allow mixing bypass and mapped DMA operation
2020-12-22 13:19:43 -08:00
Andrey Konovalov cebd0eb29a kasan: rename (un)poison_shadow to (un)poison_range
This is a preparatory commit for the upcoming addition of a new hardware
tag-based (MTE-based) KASAN mode.

The new mode won't be using shadow memory.  Rename external annotation
kasan_unpoison_shadow() to kasan_unpoison_range(), and introduce internal
functions (un)poison_range() (without kasan_ prefix).

Co-developed-by: Marco Elver <elver@google.com>
Link: https://lkml.kernel.org/r/fccdcaa13dc6b2211bf363d6c6d499279a54fe3a.1606161801.git.andreyknvl@google.com
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-22 12:55:06 -08:00
Rafael J. Wysocki c3a74f8e25 Merge branch 'pm-cpufreq'
* pm-cpufreq:
  cpufreq: intel_pstate: Use most recent guaranteed performance values
  cpufreq: intel_pstate: Implement the ->adjust_perf() callback
  cpufreq: Add special-purpose fast-switching callback for drivers
  cpufreq: schedutil: Add util to struct sg_cpu
  cppc_cpufreq: replace per-cpu data array with a list
  cppc_cpufreq: expose information on frequency domains
  cppc_cpufreq: clarify support for coordination types
  cppc_cpufreq: use policy->cpu as driver of frequency setting
  ACPI: processor: fix NONE coordination for domain mapping failure
  ACPI: processor: Drop duplicate setting of shared_cpu_map
2020-12-22 17:59:11 +01:00
Eric Dumazet e7e518053c bpf: Add schedule point in htab_init_buckets()
We noticed that with a LOCKDEP enabled kernel,
allocating a hash table with 65536 buckets would
use more than 60ms.

htab_init_buckets() runs from process context,
it is safe to schedule to avoid latency spikes.

Fixes: c50eb518e2 ("bpf: Use separate lockdep class for each hashtab")
Reported-by: John Sperbeck <jsperbeck@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20201221192506.707584-1-eric.dumazet@gmail.com
2020-12-22 00:14:31 +01:00
Linus Torvalds 6a447b0e31 ARM:
* PSCI relay at EL2 when "protected KVM" is enabled
 * New exception injection code
 * Simplification of AArch32 system register handling
 * Fix PMU accesses when no PMU is enabled
 * Expose CSV3 on non-Meltdown hosts
 * Cache hierarchy discovery fixes
 * PV steal-time cleanups
 * Allow function pointers at EL2
 * Various host EL2 entry cleanups
 * Simplification of the EL2 vector allocation
 
 s390:
 * memcg accouting for s390 specific parts of kvm and gmap
 * selftest for diag318
 * new kvm_stat for when async_pf falls back to sync
 
 x86:
 * Tracepoints for the new pagetable code from 5.10
 * Catch VFIO and KVM irqfd events before userspace
 * Reporting dirty pages to userspace with a ring buffer
 * SEV-ES host support
 * Nested VMX support for wait-for-SIPI activity state
 * New feature flag (AVX512 FP16)
 * New system ioctl to report Hyper-V-compatible paravirtualization features
 
 Generic:
 * Selftest improvements
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM updates from Paolo Bonzini:
 "Much x86 work was pushed out to 5.12, but ARM more than made up for it.

  ARM:
   - PSCI relay at EL2 when "protected KVM" is enabled
   - New exception injection code
   - Simplification of AArch32 system register handling
   - Fix PMU accesses when no PMU is enabled
   - Expose CSV3 on non-Meltdown hosts
   - Cache hierarchy discovery fixes
   - PV steal-time cleanups
   - Allow function pointers at EL2
   - Various host EL2 entry cleanups
   - Simplification of the EL2 vector allocation

  s390:
   - memcg accouting for s390 specific parts of kvm and gmap
   - selftest for diag318
   - new kvm_stat for when async_pf falls back to sync

  x86:
   - Tracepoints for the new pagetable code from 5.10
   - Catch VFIO and KVM irqfd events before userspace
   - Reporting dirty pages to userspace with a ring buffer
   - SEV-ES host support
   - Nested VMX support for wait-for-SIPI activity state
   - New feature flag (AVX512 FP16)
   - New system ioctl to report Hyper-V-compatible paravirtualization features

  Generic:
   - Selftest improvements"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (171 commits)
  KVM: SVM: fix 32-bit compilation
  KVM: SVM: Add AP_JUMP_TABLE support in prep for AP booting
  KVM: SVM: Provide support to launch and run an SEV-ES guest
  KVM: SVM: Provide an updated VMRUN invocation for SEV-ES guests
  KVM: SVM: Provide support for SEV-ES vCPU loading
  KVM: SVM: Provide support for SEV-ES vCPU creation/loading
  KVM: SVM: Update ASID allocation to support SEV-ES guests
  KVM: SVM: Set the encryption mask for the SVM host save area
  KVM: SVM: Add NMI support for an SEV-ES guest
  KVM: SVM: Guest FPU state save/restore not needed for SEV-ES guest
  KVM: SVM: Do not report support for SMM for an SEV-ES guest
  KVM: x86: Update __get_sregs() / __set_sregs() to support SEV-ES
  KVM: SVM: Add support for CR8 write traps for an SEV-ES guest
  KVM: SVM: Add support for CR4 write traps for an SEV-ES guest
  KVM: SVM: Add support for CR0 write traps for an SEV-ES guest
  KVM: SVM: Add support for EFER write traps for an SEV-ES guest
  KVM: SVM: Support string IO operations for an SEV-ES guest
  KVM: SVM: Support MMIO for an SEV-ES guest
  KVM: SVM: Create trace events for VMGEXIT MSR protocol processing
  KVM: SVM: Create trace events for VMGEXIT processing
  ...
2020-12-20 10:44:05 -08:00
Willem de Bruijn b0a0c2615f epoll: wire up syscall epoll_pwait2
Split off from prev patch in the series that implements the syscall.

Link: https://lkml.kernel.org/r/20201121144401.3727659-4-willemdebruijn.kernel@gmail.com
Signed-off-by: Willem de Bruijn <willemb@google.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-19 11:18:38 -08:00
Colin Ian King f6f5cd840a timekeeping: Fix spelling mistake in Kconfig "fullfill" -> "fulfill"
There is a spelling mistake in the Kconfig help text. Fix it.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20201217171705.57586-1-colin.king@canonical.com
2020-12-18 23:15:00 +01:00
Zenghui Yu 06fde695ee genirq/msi: Initialize msi_alloc_info before calling msi_domain_prepare_irqs()
Since commit 5fe71d271d ("irqchip/gic-v3-its: Tag ITS device as shared if
allocating for a proxy device"), some of the devices are wrongly marked as
"shared" by the ITS driver on systems equipped with the ITS(es). The
problem is that the @info->flags may not be initialized anywhere and we end
up looking at random bits on the stack. That's obviously not good.

We can perform the initialization in the IRQ core layer before calling
msi_domain_prepare_irqs(), which is neat enough.

Fixes: 5fe71d271d ("irqchip/gic-v3-its: Tag ITS device as shared if allocating for a proxy device")
Signed-off-by: Zenghui Yu <yuzenghui@huawei.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201218060039.1770-1-yuzenghui@huawei.com
2020-12-18 17:42:18 +00:00
Peter Zijlstra 91ea62d58b softirq: Avoid bad tracing / lockdep interaction
Similar to commit:

  1a63dcd876 ("softirq: Reorder trace_softirqs_on to prevent lockdep splat")

__local_bh_enable_ip() can also call into tracing with inconsistent
state. Unlike that commit we don't need to bother about the tracepoint
because 'cnt-1' never matches preempt_count() (by construction).

Reported-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Heiko Carstens <hca@linux.ibm.com>
Link: https://lkml.kernel.org/r/20201218154519.GW3092@hirez.programming.kicks-ass.net
2020-12-18 16:53:13 +01:00