Commit Graph

37762 Commits

Author SHA1 Message Date
Linus Torvalds
7587a4a5a4 - Prevent a tick storm when a dedicated timekeeper CPU in nohz_full
mode runs for prolonged periods with interrupts disabled and ends up
 programming the next tick in the past, leading to that storm
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Merge tag 'timers_urgent_for_v5.16_rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull timer fix from Borislav Petkov:

 - Prevent a tick storm when a dedicated timekeeper CPU in nohz_full
   mode runs for prolonged periods with interrupts disabled and ends up
   programming the next tick in the past, leading to that storm

* tag 'timers_urgent_for_v5.16_rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  timers/nohz: Last resort update jiffies on nohz_full IRQ entry
2021-12-05 08:58:52 -08:00
Linus Torvalds
1d213767dc - Properly init uclamp_flags of a runqueue, on first enqueuing
- Fix preempt= callback return values
 
 - Correct utime/stime resource usage reporting on nohz_full to return
 the proper times instead of shorter ones
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Merge tag 'sched_urgent_for_v5.16_rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler fixes from Borislav Petkov:

 - Properly init uclamp_flags of a runqueue, on first enqueuing

 - Fix preempt= callback return values

 - Correct utime/stime resource usage reporting on nohz_full to return
   the proper times instead of shorter ones

* tag 'sched_urgent_for_v5.16_rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/uclamp: Fix rq->uclamp_max not set on first enqueue
  preempt/dynamic: Fix setup_preempt_mode() return value
  sched/cputime: Fix getrusage(RUSAGE_THREAD) with nohz_full
2021-12-05 08:53:31 -08:00
Qais Yousef
315c4f8848 sched/uclamp: Fix rq->uclamp_max not set on first enqueue
Commit d81ae8aac8 ("sched/uclamp: Fix initialization of struct
uclamp_rq") introduced a bug where uclamp_max of the rq is not reset to
match the woken up task's uclamp_max when the rq is idle.

The code was relying on rq->uclamp_max initialized to zero, so on first
enqueue

	static inline void uclamp_rq_inc_id(struct rq *rq, struct task_struct *p,
					    enum uclamp_id clamp_id)
	{
		...

		if (uc_se->value > READ_ONCE(uc_rq->value))
			WRITE_ONCE(uc_rq->value, uc_se->value);
	}

was actually resetting it. But since commit d81ae8aac8 changed the
default to 1024, this no longer works. And since rq->uclamp_flags is
also initialized to 0, neither above code path nor uclamp_idle_reset()
update the rq->uclamp_max on first wake up from idle.

This is only visible from first wake up(s) until the first dequeue to
idle after enabling the static key. And it only matters if the
uclamp_max of this task is < 1024 since only then its uclamp_max will be
effectively ignored.

Fix it by properly initializing rq->uclamp_flags = UCLAMP_FLAG_IDLE to
ensure uclamp_idle_reset() is called which then will update the rq
uclamp_max value as expected.

Fixes: d81ae8aac8 ("sched/uclamp: Fix initialization of struct uclamp_rq")
Signed-off-by: Qais Yousef <qais.yousef@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <Valentin.Schneider@arm.com>
Tested-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Link: https://lkml.kernel.org/r/20211202112033.1705279-1-qais.yousef@arm.com
2021-12-04 10:56:18 +01:00
Andrew Halaney
9ed20bafc8 preempt/dynamic: Fix setup_preempt_mode() return value
__setup() callbacks expect 1 for success and 0 for failure. Correct the
usage here to reflect that.

Fixes: 826bfeb37b ("preempt/dynamic: Support dynamic preempt with preempt= boot option")
Reported-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Andrew Halaney <ahalaney@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20211203233203.133581-1-ahalaney@redhat.com
2021-12-04 10:56:18 +01:00
Frederic Weisbecker
e7f2be115f sched/cputime: Fix getrusage(RUSAGE_THREAD) with nohz_full
getrusage(RUSAGE_THREAD) with nohz_full may return shorter utime/stime
than the actual time.

task_cputime_adjusted() snapshots utime and stime and then adjust their
sum to match the scheduler maintained cputime.sum_exec_runtime.
Unfortunately in nohz_full, sum_exec_runtime is only updated once per
second in the worst case, causing a discrepancy against utime and stime
that can be updated anytime by the reader using vtime.

To fix this situation, perform an update of cputime.sum_exec_runtime
when the cputime snapshot reports the task as actually running while
the tick is disabled. The related overhead is then contained within the
relevant situations.

Reported-by: Hasegawa Hitomi <hasegawa-hitomi@fujitsu.com>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Hasegawa Hitomi <hasegawa-hitomi@fujitsu.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com>
Acked-by: Phil Auld <pauld@redhat.com>
Link: https://lore.kernel.org/r/20211026141055.57358-3-frederic@kernel.org
2021-12-02 15:08:22 +01:00
Frederic Weisbecker
53e87e3cdc timers/nohz: Last resort update jiffies on nohz_full IRQ entry
When at least one CPU runs in nohz_full mode, a dedicated timekeeper CPU
is guaranteed to stay online and to never stop its tick.

Meanwhile on some rare case, the dedicated timekeeper may be running
with interrupts disabled for a while, such as in stop_machine.

If jiffies stop being updated, a nohz_full CPU may end up endlessly
programming the next tick in the past, taking the last jiffies update
monotonic timestamp as a stale base, resulting in an tick storm.

Here is a scenario where it matters:

0) CPU 0 is the timekeeper and CPU 1 a nohz_full CPU.

1) A stop machine callback is queued to execute somewhere.

2) CPU 0 reaches MULTI_STOP_DISABLE_IRQ while CPU 1 is still in
   MULTI_STOP_PREPARE. Hence CPU 0 can't do its timekeeping duty. CPU 1
   can still take IRQs.

3) CPU 1 receives an IRQ which queues a timer callback one jiffy forward.

4) On IRQ exit, CPU 1 schedules the tick one jiffy forward, taking
   last_jiffies_update as a base. But last_jiffies_update hasn't been
   updated for 2 jiffies since the timekeeper has interrupts disabled.

5) clockevents_program_event(), which relies on ktime_get(), observes
   that the expiration is in the past and therefore programs the min
   delta event on the clock.

6) The tick fires immediately, goto 3)

7) Tick storm, the nohz_full CPU is drown and takes ages to reach
   MULTI_STOP_DISABLE_IRQ, which is the only way out of this situation.

Solve this with unconditionally updating jiffies if the value is stale
on nohz_full IRQ entry. IRQs and other disturbances are expected to be
rare enough on nohz_full for the unconditional call to ktime_get() to
actually matter.

Reported-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Paul E. McKenney <paulmck@kernel.org>
Link: https://lore.kernel.org/r/20211026141055.57358-2-frederic@kernel.org
2021-12-02 15:07:22 +01:00
Masami Hiramatsu
6bbfa44116 kprobes: Limit max data_size of the kretprobe instances
The 'kprobe::data_size' is unsigned, thus it can not be negative.  But if
user sets it enough big number (e.g. (size_t)-8), the result of 'data_size
+ sizeof(struct kretprobe_instance)' becomes smaller than sizeof(struct
kretprobe_instance) or zero. In result, the kretprobe_instance are
allocated without enough memory, and kretprobe accesses outside of
allocated memory.

To avoid this issue, introduce a max limitation of the
kretprobe::data_size. 4KB per instance should be OK.

Link: https://lkml.kernel.org/r/163836995040.432120.10322772773821182925.stgit@devnote2

Cc: stable@vger.kernel.org
Fixes: f47cd9b553 ("kprobes: kretprobe user entry-handler")
Reported-by: zhangyue <zhangyue1@kylinos.cn>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-12-01 21:04:34 -05:00
Chen Jun
f25667e598 tracing: Fix a kmemleak false positive in tracing_map
Doing the command:
  echo 'hist:key=common_pid.execname,common_timestamp' > /sys/kernel/debug/tracing/events/xxx/trigger

Triggers many kmemleak reports:

unreferenced object 0xffff0000c7ea4980 (size 128):
  comm "bash", pid 338, jiffies 4294912626 (age 9339.324s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<00000000f3469921>] kmem_cache_alloc_trace+0x4c0/0x6f0
    [<0000000054ca40c3>] hist_trigger_elt_data_alloc+0x140/0x178
    [<00000000633bd154>] tracing_map_init+0x1f8/0x268
    [<000000007e814ab9>] event_hist_trigger_func+0xca0/0x1ad0
    [<00000000bf8520ed>] trigger_process_regex+0xd4/0x128
    [<00000000f549355a>] event_trigger_write+0x7c/0x120
    [<00000000b80f898d>] vfs_write+0xc4/0x380
    [<00000000823e1055>] ksys_write+0x74/0xf8
    [<000000008a9374aa>] __arm64_sys_write+0x24/0x30
    [<0000000087124017>] do_el0_svc+0x88/0x1c0
    [<00000000efd0dcd1>] el0_svc+0x1c/0x28
    [<00000000dbfba9b3>] el0_sync_handler+0x88/0xc0
    [<00000000e7399680>] el0_sync+0x148/0x180
unreferenced object 0xffff0000c7ea4980 (size 128):
  comm "bash", pid 338, jiffies 4294912626 (age 9339.324s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<00000000f3469921>] kmem_cache_alloc_trace+0x4c0/0x6f0
    [<0000000054ca40c3>] hist_trigger_elt_data_alloc+0x140/0x178
    [<00000000633bd154>] tracing_map_init+0x1f8/0x268
    [<000000007e814ab9>] event_hist_trigger_func+0xca0/0x1ad0
    [<00000000bf8520ed>] trigger_process_regex+0xd4/0x128
    [<00000000f549355a>] event_trigger_write+0x7c/0x120
    [<00000000b80f898d>] vfs_write+0xc4/0x380
    [<00000000823e1055>] ksys_write+0x74/0xf8
    [<000000008a9374aa>] __arm64_sys_write+0x24/0x30
    [<0000000087124017>] do_el0_svc+0x88/0x1c0
    [<00000000efd0dcd1>] el0_svc+0x1c/0x28
    [<00000000dbfba9b3>] el0_sync_handler+0x88/0xc0
    [<00000000e7399680>] el0_sync+0x148/0x180

The reason is elts->pages[i] is alloced by get_zeroed_page.
and kmemleak will not scan the area alloced by get_zeroed_page.
The address stored in elts->pages will be regarded as leaked.

That is, the elts->pages[i] will have pointers loaded onto it as well, and
without telling kmemleak about it, those pointers will look like memory
without a reference.

To fix this, call kmemleak_alloc to tell kmemleak to scan elts->pages[i]

Link: https://lkml.kernel.org/r/20211124140801.87121-1-chenjun102@huawei.com

Signed-off-by: Chen Jun <chenjun102@huawei.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-12-01 21:04:34 -05:00
Steven Rostedt (VMware)
450fec13d9 tracing/histograms: String compares should not care about signed values
When comparing two strings for the "onmatch" histogram trigger, fields
that are strings use string comparisons, which do not care about being
signed or not.

Do not fail to match two string fields if one is unsigned char array and
the other is a signed char array.

Link: https://lore.kernel.org/all/20211129123043.5cfd687a@gandalf.local.home/

Cc: stable@vgerk.kernel.org
Cc: Tom Zanussi <zanussi@kernel.org>
Cc: Yafang Shao <laoar.shao@gmail.com>
Fixes: b05e89ae7c ("tracing: Accept different type for synthetic event fields")
Reviewed-by: Masami Hiramatsu <mhiramatsu@kernel.org>
Reported-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-12-01 21:04:22 -05:00
Linus Torvalds
97891bbf38 A single scheduler fix to ensure that there is no stale KASAN shadow state
left on the idle task's stack when a CPU is brought up after it was brought
 down before.
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Merge tag 'sched-urgent-2021-11-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler fix from Thomas Gleixner:
 "A single scheduler fix to ensure that there is no stale KASAN shadow
  state left on the idle task's stack when a CPU is brought up after it
  was brought down before"

* tag 'sched-urgent-2021-11-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/scs: Reset task stack state in bringup_cpu()
2021-11-28 09:15:34 -08:00
Linus Torvalds
1ed1d3a3da A single fix for perf to prevent that it sends SIGTRAP to another task from
a trace point event as it's not possible to deliver a synchronous signal to
 a different task from there.
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Merge tag 'perf-urgent-2021-11-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull perf fix from Thomas Gleixner:
 "A single fix for perf to prevent it from sending SIGTRAP to another
  task from a trace point event as it's not possible to deliver a
  synchronous signal to a different task from there"

* tag 'perf-urgent-2021-11-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf: Ignore sigtrap for tracepoints destined for other tasks
2021-11-28 09:10:54 -08:00
Linus Torvalds
d039f38801 Two regression fixes for reader writer semaphores:
- Plug a race in the lock handoff which is caused by inconsistency of the
    reader and writer path and can lead to corruption of the underlying
    counter.
 
  - down_read_trylock() is suboptimal when the lock is contended and
    multiple readers trylock concurrently. That's due to the initial value
    being read non-atomically which results in at least two compare exchange
    loops. Making the initial readout atomic reduces this significantly.
    Whith 40 readers by 11% in a benchmark which enforces contention on
    mmap_sem.
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Merge tag 'locking-urgent-2021-11-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull locking fixes from Thomas Gleixner:
 "Two regression fixes for reader writer semaphores:

   - Plug a race in the lock handoff which is caused by inconsistency of
     the reader and writer path and can lead to corruption of the
     underlying counter.

   - down_read_trylock() is suboptimal when the lock is contended and
     multiple readers trylock concurrently. That's due to the initial
     value being read non-atomically which results in at least two
     compare exchange loops. Making the initial readout atomic reduces
     this significantly. Whith 40 readers by 11% in a benchmark which
     enforces contention on mmap_sem"

* tag 'locking-urgent-2021-11-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking/rwsem: Optimize down_read_trylock() under highly contended case
  locking/rwsem: Make handoff bit handling more consistent
2021-11-28 09:04:41 -08:00
Linus Torvalds
f8132d62a2 tracing: Fix the fix of pid filtering
- The setting of the pid filtering flag tested the "trace only this
   pid" case twice, and ignored the "trace everything but this pid" case.
 
   Note, the 5.15 kernel does things a little differently due to the new
   sparse pid mask introduced in 5.16, and as the bug was discovered
   running the 5.15 kernel, and the first fix was initially done for
   that kernel, that fix handled both cases (only pid and all but pid),
   but the forward port to 5.16 created this bug.
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Merge tag 'trace-v5.16-rc2-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull another tracing fix from Steven Rostedt:
 "Fix the fix of pid filtering

  The setting of the pid filtering flag tested the "trace only this pid"
  case twice, and ignored the "trace everything but this pid" case.

  The 5.15 kernel does things a little differently due to the new sparse
  pid mask introduced in 5.16, and as the bug was discovered running the
  5.15 kernel, and the first fix was initially done for that kernel,
  that fix handled both cases (only pid and all but pid), but the
  forward port to 5.16 created this bug"

* tag 'trace-v5.16-rc2-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Test the 'Do not trace this pid' case in create event
2021-11-28 08:50:53 -08:00
Steven Rostedt (VMware)
27ff768fa2 tracing: Test the 'Do not trace this pid' case in create event
When creating a new event (via a module, kprobe, eprobe, etc), the
descriptors that are created must add flags for pid filtering if an
instance has pid filtering enabled, as the flags are used at the time the
event is executed to know if pid filtering should be done or not.

The "Only trace this pid" case was added, but a cut and paste error made
that case checked twice, instead of checking the "Trace all but this pid"
case.

Link: https://lore.kernel.org/all/202111280401.qC0z99JB-lkp@intel.com/

Fixes: 6cb206508b ("tracing: Check pid filtering when creating events")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-11-27 16:50:43 -05:00
Linus Torvalds
86155d6b43 Two fixes to event pid filtering:
- Have created events reflect the current state of pid filtering
 
 - Test pid filtering on discard test of recorded logic.
   (Also clean up the if statement to be cleaner).
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Merge tag 'trace-v5.16-rc2-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixes from Steven Rostedt:
 "Two fixes to event pid filtering:

   - Make sure newly created events reflect the current state of pid
     filtering

   - Take pid filtering into account when recording trigger events.
     (Also clean up the if statement to be cleaner)"

* tag 'trace-v5.16-rc2-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Fix pid filtering when triggers are attached
  tracing: Check pid filtering when creating events
2021-11-27 12:03:57 -08:00
Steven Rostedt (VMware)
a55f224ff5 tracing: Fix pid filtering when triggers are attached
If a event is filtered by pid and a trigger that requires processing of
the event to happen is a attached to the event, the discard portion does
not take the pid filtering into account, and the event will then be
recorded when it should not have been.

Cc: stable@vger.kernel.org
Fixes: 3fdaf80f4a ("tracing: Implement event pid filtering")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-11-26 17:37:06 -05:00
Linus Torvalds
0ce629b15d Power management fixes for 5.16-rc3
- Make intel_pstate work correctly on Ice Lake server systems with
    out-of-band performance control enabled (Adamos Ttofari).
 
  - Fix EPP handling in intel_pstate during CPU offline and online in
    the active mode (Rafael Wysocki).
 
  - Make intel_pstate support ITMT on asymmetric systems with
    overclocking enabled (Srinivas Pandruvada).
 
  - Fix hibernation image saving when using the user space interface
    based on the snapshot special device file (Evan Green).
 
  - Make the hibernation code release the snapshot block device using
    the same mode that was used when acquiring it (Thomas Zeitlhofer).
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Merge tag 'pm-5.16-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management fixes from Rafael Wysocki:
 "These address three issues in the intel_pstate driver and fix two
  problems related to hibernation.

  Specifics:

   - Make intel_pstate work correctly on Ice Lake server systems with
     out-of-band performance control enabled (Adamos Ttofari).

   - Fix EPP handling in intel_pstate during CPU offline and online in
     the active mode (Rafael Wysocki).

   - Make intel_pstate support ITMT on asymmetric systems with
     overclocking enabled (Srinivas Pandruvada).

   - Fix hibernation image saving when using the user space interface
     based on the snapshot special device file (Evan Green).

   - Make the hibernation code release the snapshot block device using
     the same mode that was used when acquiring it (Thomas Zeitlhofer)"

* tag 'pm-5.16-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  PM: hibernate: Fix snapshot partial write lengths
  PM: hibernate: use correct mode for swsusp_close()
  cpufreq: intel_pstate: ITMT support for overclocked system
  cpufreq: intel_pstate: Fix active mode offline/online EPP handling
  cpufreq: intel_pstate: Add Ice Lake server to out-of-band IDs
2021-11-26 12:14:50 -08:00
Steven Rostedt (VMware)
6cb206508b tracing: Check pid filtering when creating events
When pid filtering is activated in an instance, all of the events trace
files for that instance has the PID_FILTER flag set. This determines
whether or not pid filtering needs to be done on the event, otherwise the
event is executed as normal.

If pid filtering is enabled when an event is created (via a dynamic event
or modules), its flag is not updated to reflect the current state, and the
events are not filtered properly.

Cc: stable@vger.kernel.org
Fixes: 3fdaf80f4a ("tracing: Implement event pid filtering")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-11-26 14:31:23 -05:00
Evan Green
88a5045f17 PM: hibernate: Fix snapshot partial write lengths
snapshot_write() is inappropriately limiting the amount of data that can
be written in cases where a partial page has already been written. For
example, one would expect to be able to write 1 byte, then 4095 bytes to
the snapshot device, and have both of those complete fully (since now
we're aligned to a page again). But what ends up happening is we write 1
byte, then 4094/4095 bytes complete successfully.

The reason is that simple_write_to_buffer()'s second argument is the
total size of the buffer, not the size of the buffer minus the offset.
Since simple_write_to_buffer() accounts for the offset in its
implementation, snapshot_write() can just pass the full page size
directly down.

Signed-off-by: Evan Green <evgreen@chromium.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2021-11-24 13:50:18 +01:00
Thomas Zeitlhofer
cefcf24b4d PM: hibernate: use correct mode for swsusp_close()
Commit 39fbef4b0f ("PM: hibernate: Get block device exclusively in
swsusp_check()") changed the opening mode of the block device to
(FMODE_READ | FMODE_EXCL).

In the corresponding calls to swsusp_close(), the mode is still just
FMODE_READ which triggers the warning in blkdev_flush_mapping() on
resume from hibernate.

So, use the mode (FMODE_READ | FMODE_EXCL) also when closing the
device.

Fixes: 39fbef4b0f ("PM: hibernate: Get block device exclusively in swsusp_check()")
Signed-off-by: Thomas Zeitlhofer <thomas.zeitlhofer+lkml@ze-it.at>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2021-11-24 13:45:54 +01:00
Mark Rutland
dce1ca0525 sched/scs: Reset task stack state in bringup_cpu()
To hot unplug a CPU, the idle task on that CPU calls a few layers of C
code before finally leaving the kernel. When KASAN is in use, poisoned
shadow is left around for each of the active stack frames, and when
shadow call stacks are in use. When shadow call stacks (SCS) are in use
the task's saved SCS SP is left pointing at an arbitrary point within
the task's shadow call stack.

When a CPU is offlined than onlined back into the kernel, this stale
state can adversely affect execution. Stale KASAN shadow can alias new
stackframes and result in bogus KASAN warnings. A stale SCS SP is
effectively a memory leak, and prevents a portion of the shadow call
stack being used. Across a number of hotplug cycles the idle task's
entire shadow call stack can become unusable.

We previously fixed the KASAN issue in commit:

  e1b77c9298 ("sched/kasan: remove stale KASAN poison after hotplug")

... by removing any stale KASAN stack poison immediately prior to
onlining a CPU.

Subsequently in commit:

  f1a0a376ca ("sched/core: Initialize the idle task with preemption disabled")

... the refactoring left the KASAN and SCS cleanup in one-time idle
thread initialization code rather than something invoked prior to each
CPU being onlined, breaking both as above.

We fixed SCS (but not KASAN) in commit:

  63acd42c0d ("sched/scs: Reset the shadow stack when idle_task_exit")

... but as this runs in the context of the idle task being offlined it's
potentially fragile.

To fix these consistently and more robustly, reset the SCS SP and KASAN
shadow of a CPU's idle task immediately before we online that CPU in
bringup_cpu(). This ensures the idle task always has a consistent state
when it is running, and removes the need to so so when exiting an idle
task.

Whenever any thread is created, dup_task_struct() will give the task a
stack which is free of KASAN shadow, and initialize the task's SCS SP,
so there's no need to specially initialize either for idle thread within
init_idle(), as this was only necessary to handle hotplug cycles.

I've tested this on arm64 with:

* gcc 11.1.0, defconfig +KASAN_INLINE, KASAN_STACK
* clang 12.0.0, defconfig +KASAN_INLINE, KASAN_STACK, SHADOW_CALL_STACK

... offlining and onlining CPUS with:

| while true; do
|   for C in /sys/devices/system/cpu/cpu*/online; do
|     echo 0 > $C;
|     echo 1 > $C;
|   done
| done

Fixes: f1a0a376ca ("sched/core: Initialize the idle task with preemption disabled")
Reported-by: Qian Cai <quic_qiancai@quicinc.com>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Tested-by: Qian Cai <quic_qiancai@quicinc.com>
Link: https://lore.kernel.org/lkml/20211115113310.35693-1-mark.rutland@arm.com/
2021-11-24 12:20:27 +01:00
Jiri Olsa
1880ed71ce tracing/uprobe: Fix uprobe_perf_open probes iteration
Add missing 'tu' variable initialization in the probes loop,
otherwise the head 'tu' is used instead of added probes.

Link: https://lkml.kernel.org/r/20211123142801.182530-1-jolsa@kernel.org

Cc: stable@vger.kernel.org
Fixes: 99c9a923e9 ("tracing/uprobe: Fix double perf_event linking on multiprobe uprobe")
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-11-23 20:52:01 -05:00
Marco Elver
73743c3b09 perf: Ignore sigtrap for tracepoints destined for other tasks
syzbot reported that the warning in perf_sigtrap() fires, saying that
the event's task does not match current:

 | WARNING: CPU: 0 PID: 9090 at kernel/events/core.c:6446 perf_pending_event+0x40d/0x4b0 kernel/events/core.c:6513
 | Modules linked in:
 | CPU: 0 PID: 9090 Comm: syz-executor.1 Not tainted 5.15.0-syzkaller #0
 | Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 | RIP: 0010:perf_sigtrap kernel/events/core.c:6446 [inline]
 | RIP: 0010:perf_pending_event_disable kernel/events/core.c:6470 [inline]
 | RIP: 0010:perf_pending_event+0x40d/0x4b0 kernel/events/core.c:6513
 | ...
 | Call Trace:
 |  <IRQ>
 |  irq_work_single+0x106/0x220 kernel/irq_work.c:211
 |  irq_work_run_list+0x6a/0x90 kernel/irq_work.c:242
 |  irq_work_run+0x4f/0xd0 kernel/irq_work.c:251
 |  __sysvec_irq_work+0x95/0x3d0 arch/x86/kernel/irq_work.c:22
 |  sysvec_irq_work+0x8e/0xc0 arch/x86/kernel/irq_work.c:17
 |  </IRQ>
 |  <TASK>
 |  asm_sysvec_irq_work+0x12/0x20 arch/x86/include/asm/idtentry.h:664
 | RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
 | RIP: 0010:_raw_spin_unlock_irqrestore+0x38/0x70 kernel/locking/spinlock.c:194
 | ...
 |  coredump_task_exit kernel/exit.c:371 [inline]
 |  do_exit+0x1865/0x25c0 kernel/exit.c:771
 |  do_group_exit+0xe7/0x290 kernel/exit.c:929
 |  get_signal+0x3b0/0x1ce0 kernel/signal.c:2820
 |  arch_do_signal_or_restart+0x2a9/0x1c40 arch/x86/kernel/signal.c:868
 |  handle_signal_work kernel/entry/common.c:148 [inline]
 |  exit_to_user_mode_loop kernel/entry/common.c:172 [inline]
 |  exit_to_user_mode_prepare+0x17d/0x290 kernel/entry/common.c:207
 |  __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline]
 |  syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:300
 |  do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86
 |  entry_SYSCALL_64_after_hwframe+0x44/0xae

On x86 this shouldn't happen, which has arch_irq_work_raise().

The test program sets up a perf event with sigtrap set to fire on the
'sched_wakeup' tracepoint, which fired in ttwu_do_wakeup().

This happened because the 'sched_wakeup' tracepoint also takes a task
argument passed on to perf_tp_event(), which is used to deliver the
event to that other task.

Since we cannot deliver synchronous signals to other tasks, skip an event if
perf_tp_event() is targeted at another task and perf_event_attr::sigtrap is
set, which will avoid ever entering perf_sigtrap() for such events.

Fixes: 97ba62b278 ("perf: Add support for SIGTRAP on perf events")
Reported-by: syzbot+663359e32ce6f1a305ad@syzkaller.appspotmail.com
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/YYpoCOBmC/kJWfmI@elver.google.com
2021-11-23 09:45:37 +01:00
Muchun Song
14c2404884 locking/rwsem: Optimize down_read_trylock() under highly contended case
We found that a process with 10 thousnads threads has been encountered
a regression problem from Linux-v4.14 to Linux-v5.4. It is a kind of
workload which will concurrently allocate lots of memory in different
threads sometimes. In this case, we will see the down_read_trylock()
with a high hotspot. Therefore, we suppose that rwsem has a regression
at least since Linux-v5.4. In order to easily debug this problem, we
write a simply benchmark to create the similar situation lile the
following.

  ```c++
  #include <sys/mman.h>
  #include <sys/time.h>
  #include <sys/resource.h>
  #include <sched.h>

  #include <cstdio>
  #include <cassert>
  #include <thread>
  #include <vector>
  #include <chrono>

  volatile int mutex;

  void trigger(int cpu, char* ptr, std::size_t sz)
  {
  	cpu_set_t set;
  	CPU_ZERO(&set);
  	CPU_SET(cpu, &set);
  	assert(pthread_setaffinity_np(pthread_self(), sizeof(set), &set) == 0);

  	while (mutex);

  	for (std::size_t i = 0; i < sz; i += 4096) {
  		*ptr = '\0';
  		ptr += 4096;
  	}
  }

  int main(int argc, char* argv[])
  {
  	std::size_t sz = 100;

  	if (argc > 1)
  		sz = atoi(argv[1]);

  	auto nproc = std:🧵:hardware_concurrency();
  	std::vector<std::thread> thr;
  	sz <<= 30;
  	auto* ptr = mmap(nullptr, sz, PROT_READ | PROT_WRITE, MAP_ANON |
			 MAP_PRIVATE, -1, 0);
  	assert(ptr != MAP_FAILED);
  	char* cptr = static_cast<char*>(ptr);
  	auto run = sz / nproc;
  	run = (run >> 12) << 12;

  	mutex = 1;

  	for (auto i = 0U; i < nproc; ++i) {
  		thr.emplace_back(std::thread([i, cptr, run]() { trigger(i, cptr, run); }));
  		cptr += run;
  	}

  	rusage usage_start;
  	getrusage(RUSAGE_SELF, &usage_start);
  	auto start = std::chrono::system_clock::now();

  	mutex = 0;

  	for (auto& t : thr)
  		t.join();

  	rusage usage_end;
  	getrusage(RUSAGE_SELF, &usage_end);
  	auto end = std::chrono::system_clock::now();
  	timeval utime;
  	timeval stime;
  	timersub(&usage_end.ru_utime, &usage_start.ru_utime, &utime);
  	timersub(&usage_end.ru_stime, &usage_start.ru_stime, &stime);
  	printf("usr: %ld.%06ld\n", utime.tv_sec, utime.tv_usec);
  	printf("sys: %ld.%06ld\n", stime.tv_sec, stime.tv_usec);
  	printf("real: %lu\n",
  	       std::chrono::duration_cast<std::chrono::milliseconds>(end -
  	       start).count());

  	return 0;
  }
  ```

The functionality of above program is simply which creates `nproc`
threads and each of them are trying to touch memory (trigger page
fault) on different CPU. Then we will see the similar profile by
`perf top`.

  25.55%  [kernel]                  [k] down_read_trylock
  14.78%  [kernel]                  [k] handle_mm_fault
  13.45%  [kernel]                  [k] up_read
   8.61%  [kernel]                  [k] clear_page_erms
   3.89%  [kernel]                  [k] __do_page_fault

The highest hot instruction, which accounts for about 92%, in
down_read_trylock() is cmpxchg like the following.

  91.89 │      lock   cmpxchg %rdx,(%rdi)

Sice the problem is found by migrating from Linux-v4.14 to Linux-v5.4,
so we easily found that the commit ddb20d1d3a ("locking/rwsem: Optimize
down_read_trylock()") caused the regression. The reason is that the
commit assumes the rwsem is not contended at all. But it is not always
true for mmap lock which could be contended with thousands threads.
So most threads almost need to run at least 2 times of "cmpxchg" to
acquire the lock. The overhead of atomic operation is higher than
non-atomic instructions, which caused the regression.

By using the above benchmark, the real executing time on a x86-64 system
before and after the patch were:

                  Before Patch  After Patch
   # of Threads      real          real     reduced by
   ------------     ------        ------    ----------
         1          65,373        65,206       ~0.0%
         4          15,467        15,378       ~0.5%
        40           6,214         5,528      ~11.0%

For the uncontended case, the new down_read_trylock() is the same as
before. For the contended cases, the new down_read_trylock() is faster
than before. The more contended, the more fast.

Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Waiman Long <longman@redhat.com>
Link: https://lore.kernel.org/r/20211118094455.9068-1-songmuchun@bytedance.com
2021-11-23 09:45:36 +01:00
Waiman Long
d257cc8cb8 locking/rwsem: Make handoff bit handling more consistent
There are some inconsistency in the way that the handoff bit is being
handled in readers and writers that lead to a race condition.

Firstly, when a queue head writer set the handoff bit, it will clear
it when the writer is being killed or interrupted on its way out
without acquiring the lock. That is not the case for a queue head
reader. The handoff bit will simply be inherited by the next waiter.

Secondly, in the out_nolock path of rwsem_down_read_slowpath(), both
the waiter and handoff bits are cleared if the wait queue becomes
empty.  For rwsem_down_write_slowpath(), however, the handoff bit is
not checked and cleared if the wait queue is empty. This can
potentially make the handoff bit set with empty wait queue.

Worse, the situation in rwsem_down_write_slowpath() relies on wstate,
a variable set outside of the critical section containing the ->count
manipulation, this leads to race condition where RWSEM_FLAG_HANDOFF
can be double subtracted, corrupting ->count.

To make the handoff bit handling more consistent and robust, extract
out handoff bit clearing code into the new rwsem_del_waiter() helper
function. Also, completely eradicate wstate; always evaluate
everything inside the same critical section.

The common function will only use atomic_long_andnot() to clear bits
when the wait queue is empty to avoid possible race condition.  If the
first waiter with handoff bit set is killed or interrupted to exit the
slowpath without acquiring the lock, the next waiter will inherit the
handoff bit.

While at it, simplify the trylock for loop in
rwsem_down_write_slowpath() to make it easier to read.

Fixes: 4f23dbc1e6 ("locking/rwsem: Implement lock handoff to prevent lock starvation")
Reported-by: Zhenhua Ma <mazhenhua@xiaomi.com>
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20211116012912.723980-1-longman@redhat.com
2021-11-23 09:45:35 +01:00
Linus Torvalds
e4365e369f Tracing fixes:
- Fix double free in destroy_hist_field
 
  - Harden memset() of trace_iterator structure
 
  - Do not warn in trace printk check when test buffer fills up
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Merge tag 'trace-v5.16-6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixes from Steven Rostedt:

 - Fix double free in destroy_hist_field

 - Harden memset() of trace_iterator structure

 - Do not warn in trace printk check when test buffer fills up

* tag 'trace-v5.16-6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Don't use out-of-sync va_list in event printing
  tracing: Use memset_startat() to zero struct trace_iterator
  tracing/histogram: Fix UAF in destroy_hist_field()
2021-11-19 13:50:48 -08:00
Linus Torvalds
7af959b5d5 Merge branch 'SA_IMMUTABLE-fixes-for-v5.16-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull exit-vs-signal handling fixes from Eric Biederman:
 "This is a small set of changes where debuggers were no longer able to
  intercept synchronous SIGTRAP and SIGSEGV, introduced by the exit
  cleanups.

  This is essentially the change you suggested with all of i's dotted
  and the t's crossed so that ptrace can intercept all of the cases it
  has been able to intercept the past, and all of the cases that made it
  to exit without giving ptrace a chance still don't give ptrace a
  chance"

* 'SA_IMMUTABLE-fixes-for-v5.16-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  signal: Replace force_fatal_sig with force_exit_sig when in doubt
  signal: Don't always set SA_IMMUTABLE for forced signals
2021-11-19 11:33:31 -08:00
Eric W. Biederman
fcb116bc43 signal: Replace force_fatal_sig with force_exit_sig when in doubt
Recently to prevent issues with SECCOMP_RET_KILL and similar signals
being changed before they are delivered SA_IMMUTABLE was added.

Unfortunately this broke debuggers[1][2] which reasonably expect
to be able to trap synchronous SIGTRAP and SIGSEGV even when
the target process is not configured to handle those signals.

Add force_exit_sig and use it instead of force_fatal_sig where
historically the code has directly called do_exit.  This has the
implementation benefits of going through the signal exit path
(including generating core dumps) without the danger of allowing
userspace to ignore or change these signals.

This avoids userspace regressions as older kernels exited with do_exit
which debuggers also can not intercept.

In the future is should be possible to improve the quality of
implementation of the kernel by changing some of these force_exit_sig
calls to force_fatal_sig.  That can be done where it matters on
a case-by-case basis with careful analysis.

Reported-by: Kyle Huey <me@kylehuey.com>
Reported-by: kernel test robot <oliver.sang@intel.com>
[1] https://lkml.kernel.org/r/CAP045AoMY4xf8aC_4QU_-j7obuEPYgTcnQQP3Yxk=2X90jtpjw@mail.gmail.com
[2] https://lkml.kernel.org/r/20211117150258.GB5403@xsang-OptiPlex-9020
Fixes: 00b06da29c ("signal: Add SA_IMMUTABLE to ensure forced siganls do not get changed")
Fixes: a3616a3c02 ("signal/m68k: Use force_sigsegv(SIGSEGV) in fpsp040_die")
Fixes: 83a1f27ad7 ("signal/powerpc: On swapcontext failure force SIGSEGV")
Fixes: 9bc508cf07 ("signal/s390: Use force_sigsegv in default_trap_handler")
Fixes: 086ec444f8 ("signal/sparc32: In setup_rt_frame and setup_fram use force_fatal_sig")
Fixes: c317d306d5 ("signal/sparc32: Exit with a fatal signal when try_to_clear_window_buffer fails")
Fixes: 695dd0d634 ("signal/x86: In emulate_vsyscall force a signal instead of calling do_exit")
Fixes: 1fbd60df8a ("signal/vm86_32: Properly send SIGSEGV when the vm86 state cannot be saved.")
Fixes: 941edc5bf1 ("exit/syscall_user_dispatch: Send ordinary signals on failure")
Link: https://lkml.kernel.org/r/871r3dqfv8.fsf_-_@email.froward.int.ebiederm.org
Reviewed-by: Kees Cook <keescook@chromium.org>
Tested-by: Kees Cook <keescook@chromium.org>
Tested-by: Kyle Huey <khuey@kylehuey.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2021-11-19 09:15:58 -06:00
Eric W. Biederman
e349d945fa signal: Don't always set SA_IMMUTABLE for forced signals
Recently to prevent issues with SECCOMP_RET_KILL and similar signals
being changed before they are delivered SA_IMMUTABLE was added.

Unfortunately this broke debuggers[1][2] which reasonably expect to be
able to trap synchronous SIGTRAP and SIGSEGV even when the target
process is not configured to handle those signals.

Update force_sig_to_task to support both the case when we can allow
the debugger to intercept and possibly ignore the signal and the case
when it is not safe to let userspace know about the signal until the
process has exited.

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Reported-by: Kyle Huey <me@kylehuey.com>
Reported-by: kernel test robot <oliver.sang@intel.com>
Cc: stable@vger.kernel.org
[1] https://lkml.kernel.org/r/CAP045AoMY4xf8aC_4QU_-j7obuEPYgTcnQQP3Yxk=2X90jtpjw@mail.gmail.com
[2] https://lkml.kernel.org/r/20211117150258.GB5403@xsang-OptiPlex-9020
Fixes: 00b06da29c ("signal: Add SA_IMMUTABLE to ensure forced siganls do not get changed")
Link: https://lkml.kernel.org/r/877dd5qfw5.fsf_-_@email.froward.int.ebiederm.org
Reviewed-by: Kees Cook <keescook@chromium.org>
Tested-by: Kees Cook <keescook@chromium.org>
Tested-by: Kyle Huey <khuey@kylehuey.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2021-11-19 09:11:43 -06:00
Nikita Yushchenko
2ef75e9bd2 tracing: Don't use out-of-sync va_list in event printing
If trace_seq becomes full, trace_seq_vprintf() no longer consumes
arguments from va_list, making va_list out of sync with format
processing by trace_check_vprintf().

This causes va_arg() in trace_check_vprintf() to return wrong
positional argument, which results into a WARN_ON_ONCE() hit.

ftrace_stress_test from LTP triggers this situation.

Fix it by explicitly avoiding further use if va_list at the point
when it's consistency can no longer be guaranteed.

Link: https://lkml.kernel.org/r/20211118145516.13219-1-nikita.yushchenko@virtuozzo.com

Signed-off-by: Nikita Yushchenko <nikita.yushchenko@virtuozzo.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-11-18 21:10:18 -05:00
Kees Cook
c4c1dbcc09 tracing: Use memset_startat() to zero struct trace_iterator
In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memset(), avoid intentionally writing across
neighboring fields.

Use memset_startat() to avoid confusing memset() about writing beyond
the target struct member.

Link: https://lkml.kernel.org/r/20211118202217.1285588-1-keescook@chromium.org

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-11-18 20:54:51 -05:00
Linus Torvalds
8d0112ac6f Networking fixes for 5.16-rc2, including fixes from bpf, mac80211.
Current release - regressions:
 
  - devlink: don't throw an error if flash notification sent before
    devlink visible
 
  - page_pool: Revert "page_pool: disable dma mapping support...",
    turns out there are active arches who need it
 
 Current release - new code bugs:
 
  - amt: cancel delayed_work synchronously in amt_fini()
 
 Previous releases - regressions:
 
  - xsk: fix crash on double free in buffer pool
 
  - bpf: fix inner map state pruning regression causing program
    rejections
 
  - mac80211: drop check for DONT_REORDER in __ieee80211_select_queue,
    preventing mis-selecting the best effort queue
 
  - mac80211: do not access the IV when it was stripped
 
  - mac80211: fix radiotap header generation, off-by-one
 
  - nl80211: fix getting radio statistics in survey dump
 
  - e100: fix device suspend/resume
 
 Previous releases - always broken:
 
  - tcp: fix uninitialized access in skb frags array for Rx 0cp
 
  - bpf: fix toctou on read-only map's constant scalar tracking
 
  - bpf: forbid bpf_ktime_get_coarse_ns and bpf_timer_* in tracing progs
 
  - tipc: only accept encrypted MSG_CRYPTO msgs
 
  - smc: transfer remaining wait queue entries during fallback,
    fix missing wake ups
 
  - udp: validate checksum in udp_read_sock() (when sockmap is used)
 
  - sched: act_mirred: drop dst for the direction from egress to ingress
 
  - virtio_net_hdr_to_skb: count transport header in UFO, prevent
    allowing bad skbs into the stack
 
  - nfc: reorder the logic in nfc_{un,}register_device, fix unregister
 
  - ipsec: check return value of ipv6_skip_exthdr
 
  - usb: r8152: add MAC passthrough support for more Lenovo Docks
 
 Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Merge tag 'net-5.16-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

Pull networking fixes from Jakub Kicinski:
 "Including fixes from bpf, mac80211.

  Current release - regressions:

   - devlink: don't throw an error if flash notification sent before
     devlink visible

   - page_pool: Revert "page_pool: disable dma mapping support...",
     turns out there are active arches who need it

  Current release - new code bugs:

   - amt: cancel delayed_work synchronously in amt_fini()

  Previous releases - regressions:

   - xsk: fix crash on double free in buffer pool

   - bpf: fix inner map state pruning regression causing program
     rejections

   - mac80211: drop check for DONT_REORDER in __ieee80211_select_queue,
     preventing mis-selecting the best effort queue

   - mac80211: do not access the IV when it was stripped

   - mac80211: fix radiotap header generation, off-by-one

   - nl80211: fix getting radio statistics in survey dump

   - e100: fix device suspend/resume

  Previous releases - always broken:

   - tcp: fix uninitialized access in skb frags array for Rx 0cp

   - bpf: fix toctou on read-only map's constant scalar tracking

   - bpf: forbid bpf_ktime_get_coarse_ns and bpf_timer_* in tracing
     progs

   - tipc: only accept encrypted MSG_CRYPTO msgs

   - smc: transfer remaining wait queue entries during fallback, fix
     missing wake ups

   - udp: validate checksum in udp_read_sock() (when sockmap is used)

   - sched: act_mirred: drop dst for the direction from egress to
     ingress

   - virtio_net_hdr_to_skb: count transport header in UFO, prevent
     allowing bad skbs into the stack

   - nfc: reorder the logic in nfc_{un,}register_device, fix unregister

   - ipsec: check return value of ipv6_skip_exthdr

   - usb: r8152: add MAC passthrough support for more Lenovo Docks"

* tag 'net-5.16-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (96 commits)
  ptp: ocp: Fix a couple NULL vs IS_ERR() checks
  net: ethernet: dec: tulip: de4x5: fix possible array overflows in type3_infoblock()
  net: tulip: de4x5: fix the problem that the array 'lp->phy[8]' may be out of bound
  ipv6: check return value of ipv6_skip_exthdr
  e100: fix device suspend/resume
  devlink: Don't throw an error if flash notification sent before devlink visible
  page_pool: Revert "page_pool: disable dma mapping support..."
  ethernet: hisilicon: hns: hns_dsaf_misc: fix a possible array overflow in hns_dsaf_ge_srst_by_port()
  octeontx2-af: debugfs: don't corrupt user memory
  NFC: add NCI_UNREG flag to eliminate the race
  NFC: reorder the logic in nfc_{un,}register_device
  NFC: reorganize the functions in nci_request
  tipc: check for null after calling kmemdup
  i40e: Fix display error code in dmesg
  i40e: Fix creation of first queue by omitting it if is not power of two
  i40e: Fix warning message and call stack during rmmod i40e driver
  i40e: Fix ping is lost after configuring ADq on VF
  i40e: Fix changing previously set num_queue_pairs for PFs
  i40e: Fix NULL ptr dereference on VSI filter sync
  i40e: Fix correct max_pkt_size on VF RX queue
  ...
2021-11-18 12:54:24 -08:00
Kalesh Singh
f86b0aaad7 tracing/histogram: Fix UAF in destroy_hist_field()
Calling destroy_hist_field() on an expression will recursively free
any operands associated with the expression. If during expression
parsing the operands of the expression are already set when an error
is encountered, there is no need to explicity free the operands. Doing
so will result in destroy_hist_field() being called twice for the
operands and lead to a use-after-free (UAF) error.

If the operands are associated with the expression, only call
destroy_hist_field() on the expression since the operands will be
recursively freed.

Link: https://lore.kernel.org/all/CAHk-=wgcrEbFgkw9720H3tW-AhHOoEKhYwZinYJw4FpzSaJ6_Q@mail.gmail.com/
Link: https://lkml.kernel.org/r/20211118011542.1420131-1-kaleshsingh@google.com

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
Fixes: 8b5d46fd7a ("tracing/histogram: Optimize division by constants")
Reported-by: kernel test robot <oliver.sang@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-11-18 13:53:43 -05:00
Linus Torvalds
7d5775d49e printk fixup for 5.16
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Merge tag 'printk-for-5.16-fixup' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux

Pull printk fixes from Petr Mladek:

 - Try to flush backtraces from other CPUs also on the local one. This
   was a regression caused by printk_safe buffers removal.

 - Remove header dependency warning.

* tag 'printk-for-5.16-fixup' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux:
  printk: Remove printk.h inclusion in percpu.h
  printk: restore flushing of NMI buffers on remote CPUs after NMI backtraces
2021-11-18 10:50:45 -08:00
Petr Mladek
bf6d0d1e1a Merge branch 'rework/printk_safe-removal' into for-linus 2021-11-18 10:03:47 +01:00
Jakub Kicinski
f083ec3160 Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Daniel Borkmann says:

====================
pull-request: bpf 2021-11-16

We've added 12 non-merge commits during the last 5 day(s) which contain
a total of 23 files changed, 573 insertions(+), 73 deletions(-).

The main changes are:

1) Fix pruning regression where verifier went overly conservative rejecting
   previsouly accepted programs, from Alexei Starovoitov and Lorenz Bauer.

2) Fix verifier TOCTOU bug when using read-only map's values as constant
   scalars during verification, from Daniel Borkmann.

3) Fix a crash due to a double free in XSK's buffer pool, from Magnus Karlsson.

4) Fix libbpf regression when cross-building runqslower, from Jean-Philippe Brucker.

5) Forbid use of bpf_ktime_get_coarse_ns() and bpf_timer_*() helpers in tracing
   programs due to deadlock possibilities, from Dmitrii Banshchikov.

6) Fix checksum validation in sockmap's udp_read_sock() callback, from Cong Wang.

7) Various BPF sample fixes such as XDP stats in xdp_sample_user, from Alexander Lobakin.

8) Fix libbpf gen_loader error handling wrt fd cleanup, from Kumar Kartikeya Dwivedi.

* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
  udp: Validate checksum in udp_read_sock()
  bpf: Fix toctou on read-only map's constant scalar tracking
  samples/bpf: Fix build error due to -isystem removal
  selftests/bpf: Add tests for restricted helpers
  bpf: Forbid bpf_ktime_get_coarse_ns and bpf_timer_* in tracing progs
  libbpf: Perform map fd cleanup for gen_loader in case of error
  samples/bpf: Fix incorrect use of strlen in xdp_redirect_cpu
  tools/runqslower: Fix cross-build
  samples/bpf: Fix summary per-sec stats in xdp_sample_user
  selftests/bpf: Check map in map pruning
  bpf: Fix inner map state pruning regression.
  xsk: Fix crash on double free in buffer pool
====================

Link: https://lore.kernel.org/r/20211116141134.6490-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-11-16 16:53:48 -08:00
Daniel Borkmann
353050be4c bpf: Fix toctou on read-only map's constant scalar tracking
Commit a23740ec43 ("bpf: Track contents of read-only maps as scalars") is
checking whether maps are read-only both from BPF program side and user space
side, and then, given their content is constant, reading out their data via
map->ops->map_direct_value_addr() which is then subsequently used as known
scalar value for the register, that is, it is marked as __mark_reg_known()
with the read value at verification time. Before a23740ec43, the register
content was marked as an unknown scalar so the verifier could not make any
assumptions about the map content.

The current implementation however is prone to a TOCTOU race, meaning, the
value read as known scalar for the register is not guaranteed to be exactly
the same at a later point when the program is executed, and as such, the
prior made assumptions of the verifier with regards to the program will be
invalid which can cause issues such as OOB access, etc.

While the BPF_F_RDONLY_PROG map flag is always fixed and required to be
specified at map creation time, the map->frozen property is initially set to
false for the map given the map value needs to be populated, e.g. for global
data sections. Once complete, the loader "freezes" the map from user space
such that no subsequent updates/deletes are possible anymore. For the rest
of the lifetime of the map, this freeze one-time trigger cannot be undone
anymore after a successful BPF_MAP_FREEZE cmd return. Meaning, any new BPF_*
cmd calls which would update/delete map entries will be rejected with -EPERM
since map_get_sys_perms() removes the FMODE_CAN_WRITE permission. This also
means that pending update/delete map entries must still complete before this
guarantee is given. This corner case is not an issue for loaders since they
create and prepare such program private map in successive steps.

However, a malicious user is able to trigger this TOCTOU race in two different
ways: i) via userfaultfd, and ii) via batched updates. For i) userfaultfd is
used to expand the competition interval, so that map_update_elem() can modify
the contents of the map after map_freeze() and bpf_prog_load() were executed.
This works, because userfaultfd halts the parallel thread which triggered a
map_update_elem() at the time where we copy key/value from the user buffer and
this already passed the FMODE_CAN_WRITE capability test given at that time the
map was not "frozen". Then, the main thread performs the map_freeze() and
bpf_prog_load(), and once that had completed successfully, the other thread
is woken up to complete the pending map_update_elem() which then changes the
map content. For ii) the idea of the batched update is similar, meaning, when
there are a large number of updates to be processed, it can increase the
competition interval between the two. It is therefore possible in practice to
modify the contents of the map after executing map_freeze() and bpf_prog_load().

One way to fix both i) and ii) at the same time is to expand the use of the
map's map->writecnt. The latter was introduced in fc9702273e ("bpf: Add mmap()
support for BPF_MAP_TYPE_ARRAY") and further refined in 1f6cb19be2 ("bpf:
Prevent re-mmap()'ing BPF map as writable for initially r/o mapping") with
the rationale to make a writable mmap()'ing of a map mutually exclusive with
read-only freezing. The counter indicates writable mmap() mappings and then
prevents/fails the freeze operation. Its semantics can be expanded beyond
just mmap() by generally indicating ongoing write phases. This would essentially
span any parallel regular and batched flavor of update/delete operation and
then also have map_freeze() fail with -EBUSY. For the check_mem_access() in
the verifier we expand upon the bpf_map_is_rdonly() check ensuring that all
last pending writes have completed via bpf_map_write_active() test. Once the
map->frozen is set and bpf_map_write_active() indicates a map->writecnt of 0
only then we are really guaranteed to use the map's data as known constants.
For map->frozen being set and pending writes in process of still being completed
we fall back to marking that register as unknown scalar so we don't end up
making assumptions about it. With this, both TOCTOU reproducers from i) and
ii) are fixed.

Note that the map->writecnt has been converted into a atomic64 in the fix in
order to avoid a double freeze_mutex mutex_{un,}lock() pair when updating
map->writecnt in the various map update/delete BPF_* cmd flavors. Spanning
the freeze_mutex over entire map update/delete operations in syscall side
would not be possible due to then causing everything to be serialized.
Similarly, something like synchronize_rcu() after setting map->frozen to wait
for update/deletes to complete is not possible either since it would also
have to span the user copy which can sleep. On the libbpf side, this won't
break d66562fba1 ("libbpf: Add BPF object skeleton support") as the
anonymous mmap()-ed "map initialization image" is remapped as a BPF map-backed
mmap()-ed memory where for .rodata it's non-writable.

Fixes: a23740ec43 ("bpf: Track contents of read-only maps as scalars")
Reported-by: w1tcher.bupt@gmail.com
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2021-11-15 20:47:07 -08:00
Dmitrii Banshchikov
5e0bc3082e bpf: Forbid bpf_ktime_get_coarse_ns and bpf_timer_* in tracing progs
Use of bpf_ktime_get_coarse_ns() and bpf_timer_* helpers in tracing
progs may result in locking issues.

bpf_ktime_get_coarse_ns() uses ktime_get_coarse_ns() time accessor that
isn't safe for any context:
======================================================
WARNING: possible circular locking dependency detected
5.15.0-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor.4/14877 is trying to acquire lock:
ffffffff8cb30008 (tk_core.seq.seqcount){----}-{0:0}, at: ktime_get_coarse_ts64+0x25/0x110 kernel/time/timekeeping.c:2255

but task is already holding lock:
ffffffff90dbf200 (&obj_hash[i].lock){-.-.}-{2:2}, at: debug_object_deactivate+0x61/0x400 lib/debugobjects.c:735

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #1 (&obj_hash[i].lock){-.-.}-{2:2}:
       lock_acquire+0x19f/0x4d0 kernel/locking/lockdep.c:5625
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162
       __debug_object_init+0xd9/0x1860 lib/debugobjects.c:569
       debug_hrtimer_init kernel/time/hrtimer.c:414 [inline]
       debug_init kernel/time/hrtimer.c:468 [inline]
       hrtimer_init+0x20/0x40 kernel/time/hrtimer.c:1592
       ntp_init_cmos_sync kernel/time/ntp.c:676 [inline]
       ntp_init+0xa1/0xad kernel/time/ntp.c:1095
       timekeeping_init+0x512/0x6bf kernel/time/timekeeping.c:1639
       start_kernel+0x267/0x56e init/main.c:1030
       secondary_startup_64_no_verify+0xb1/0xbb

-> #0 (tk_core.seq.seqcount){----}-{0:0}:
       check_prev_add kernel/locking/lockdep.c:3051 [inline]
       check_prevs_add kernel/locking/lockdep.c:3174 [inline]
       validate_chain+0x1dfb/0x8240 kernel/locking/lockdep.c:3789
       __lock_acquire+0x1382/0x2b00 kernel/locking/lockdep.c:5015
       lock_acquire+0x19f/0x4d0 kernel/locking/lockdep.c:5625
       seqcount_lockdep_reader_access+0xfe/0x230 include/linux/seqlock.h:103
       ktime_get_coarse_ts64+0x25/0x110 kernel/time/timekeeping.c:2255
       ktime_get_coarse include/linux/timekeeping.h:120 [inline]
       ktime_get_coarse_ns include/linux/timekeeping.h:126 [inline]
       ____bpf_ktime_get_coarse_ns kernel/bpf/helpers.c:173 [inline]
       bpf_ktime_get_coarse_ns+0x7e/0x130 kernel/bpf/helpers.c:171
       bpf_prog_a99735ebafdda2f1+0x10/0xb50
       bpf_dispatcher_nop_func include/linux/bpf.h:721 [inline]
       __bpf_prog_run include/linux/filter.h:626 [inline]
       bpf_prog_run include/linux/filter.h:633 [inline]
       BPF_PROG_RUN_ARRAY include/linux/bpf.h:1294 [inline]
       trace_call_bpf+0x2cf/0x5d0 kernel/trace/bpf_trace.c:127
       perf_trace_run_bpf_submit+0x7b/0x1d0 kernel/events/core.c:9708
       perf_trace_lock+0x37c/0x440 include/trace/events/lock.h:39
       trace_lock_release+0x128/0x150 include/trace/events/lock.h:58
       lock_release+0x82/0x810 kernel/locking/lockdep.c:5636
       __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:149 [inline]
       _raw_spin_unlock_irqrestore+0x75/0x130 kernel/locking/spinlock.c:194
       debug_hrtimer_deactivate kernel/time/hrtimer.c:425 [inline]
       debug_deactivate kernel/time/hrtimer.c:481 [inline]
       __run_hrtimer kernel/time/hrtimer.c:1653 [inline]
       __hrtimer_run_queues+0x2f9/0xa60 kernel/time/hrtimer.c:1749
       hrtimer_interrupt+0x3b3/0x1040 kernel/time/hrtimer.c:1811
       local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline]
       __sysvec_apic_timer_interrupt+0xf9/0x270 arch/x86/kernel/apic/apic.c:1103
       sysvec_apic_timer_interrupt+0x8c/0xb0 arch/x86/kernel/apic/apic.c:1097
       asm_sysvec_apic_timer_interrupt+0x12/0x20
       __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
       _raw_spin_unlock_irqrestore+0xd4/0x130 kernel/locking/spinlock.c:194
       try_to_wake_up+0x702/0xd20 kernel/sched/core.c:4118
       wake_up_process kernel/sched/core.c:4200 [inline]
       wake_up_q+0x9a/0xf0 kernel/sched/core.c:953
       futex_wake+0x50f/0x5b0 kernel/futex/waitwake.c:184
       do_futex+0x367/0x560 kernel/futex/syscalls.c:127
       __do_sys_futex kernel/futex/syscalls.c:199 [inline]
       __se_sys_futex+0x401/0x4b0 kernel/futex/syscalls.c:180
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x44/0xae

There is a possible deadlock with bpf_timer_* set of helpers:
hrtimer_start()
  lock_base();
  trace_hrtimer...()
    perf_event()
      bpf_run()
        bpf_timer_start()
          hrtimer_start()
            lock_base()         <- DEADLOCK

Forbid use of bpf_ktime_get_coarse_ns() and bpf_timer_* helpers in
BPF_PROG_TYPE_KPROBE, BPF_PROG_TYPE_TRACEPOINT, BPF_PROG_TYPE_PERF_EVENT
and BPF_PROG_TYPE_RAW_TRACEPOINT prog types.

Fixes: d055126180 ("bpf: Add bpf_ktime_get_coarse_ns helper")
Fixes: b00628b1c7 ("bpf: Introduce bpf timers.")
Reported-by: syzbot+43fd005b5a1b4d10781e@syzkaller.appspotmail.com
Signed-off-by: Dmitrii Banshchikov <me@ubique.spb.ru>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211113142227.566439-2-me@ubique.spb.ru
2021-11-15 20:35:58 -08:00
Linus Torvalds
8ab7745879 Update to tracing histogram variable string copy
A fix to only copy the size of the field to the histogram string
 did not take into account that the size can be larger than the
 storage.
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Merge tag 'trace-v5.16-5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fix from Steven Rostedt:
 "Update to tracing histogram variable string copy

  A fix to only copy the size of the field to the histogram string did
  not take into account that the size can be larger than the storage"

* tag 'trace-v5.16-5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Add length protection to histogram string copies
2021-11-14 19:07:19 -08:00
Steven Rostedt (VMware)
938aa33f14 tracing: Add length protection to histogram string copies
The string copies to the histogram storage has a max size of 256 bytes
(defined by MAX_FILTER_STR_VAL). Only the string size of the event field
needs to be copied to the event storage, but no more than what is in the
event storage. Although nothing should be bigger than 256 bytes, there's
no protection against overwriting of the storage if one day there is.

Copy no more than the destination size, and enforce it.

Also had to turn MAX_FILTER_STR_VAL into an unsigned int, to keep the
min() comparison of the string sizes of comparable types.

Link: https://lore.kernel.org/all/CAHk-=wjREUihCGrtRBwfX47y_KrLCGjiq3t6QtoNJpmVrAEb1w@mail.gmail.com/
Link: https://lkml.kernel.org/r/20211114132834.183429a4@rorschach.local.home

Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Tom Zanussi <zanussi@kernel.org>
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Fixes: 63f84ae6b8 ("tracing/histogram: Do not copy the fixed-size char array field over the field size")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-11-14 21:21:08 -05:00
Linus Torvalds
622c72b651 A single fix for POSIX CPU timers to address a problem where POSIX CPU
timer delivery stops working for a new child task because copy_process()
 copies state information which is only valid for the parent task.
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Merge tag 'timers-urgent-2021-11-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull timer fix from Thomas Gleixner:
 "A single fix for POSIX CPU timers to address a problem where POSIX CPU
  timer delivery stops working for a new child task because
  copy_process() copies state information which is only valid for the
  parent task"

* tag 'timers-urgent-2021-11-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  posix-cpu-timers: Clear task::posix_cputimers_work in copy_process()
2021-11-14 10:43:38 -08:00
Linus Torvalds
c36e33e2f4 A set of fixes for the interrupt subsystem:
- Core code:
 
     A regression fix for the Open Firmware interrupt mapping code where a
     interrupt controller property in a node caused a map property in the
     same node to be ignored.
 
   - Interrupt chip drivers:
 
     - Workaround a limitation in SiFive PLIC interrupt chip which silently
       ignores an EOI when the interrupt line is masked.
 
     - Provide the missing mask/unmask implementation for the CSKY MP
       interrupt controller.
 
   - PCI/MSI:
 
     - Prevent a use after free when PCI/MSI interrupts are released by
       destroying the sysfs entries before freeing the memory which is
       accessed in the sysfs show() function.
 
     - Implement a mask quirk for the Nvidia ION AHCI chip which does not
       advertise masking capability despite implementing it. Even worse the
       chip comes out of reset with all MSI entries masked, which due to the
       missing masking capability never get unmasked.
 
     - Move the check which prevents accessing the MSI[X] masking for XEN
       back into the low level accessors. The recent consolidation missed
       that these accessors can be invoked from places which do not have
       that check which broke XEN. Move them back to he original place
       instead of sprinkling tons of these checks all over the code.
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Merge tag 'irq-urgent-2021-11-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull irq fixes from Thomas Gleixner:
 "A set of fixes for the interrupt subsystem

  Core code:

   - A regression fix for the Open Firmware interrupt mapping code where
     a interrupt controller property in a node caused a map property in
     the same node to be ignored.

  Interrupt chip drivers:

   - Workaround a limitation in SiFive PLIC interrupt chip which
     silently ignores an EOI when the interrupt line is masked.

   - Provide the missing mask/unmask implementation for the CSKY MP
     interrupt controller.

  PCI/MSI:

   - Prevent a use after free when PCI/MSI interrupts are released by
     destroying the sysfs entries before freeing the memory which is
     accessed in the sysfs show() function.

   - Implement a mask quirk for the Nvidia ION AHCI chip which does not
     advertise masking capability despite implementing it. Even worse
     the chip comes out of reset with all MSI entries masked, which due
     to the missing masking capability never get unmasked.

   - Move the check which prevents accessing the MSI[X] masking for XEN
     back into the low level accessors. The recent consolidation missed
     that these accessors can be invoked from places which do not have
     that check which broke XEN. Move them back to he original place
     instead of sprinkling tons of these checks all over the code"

* tag 'irq-urgent-2021-11-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  of/irq: Don't ignore interrupt-controller when interrupt-map failed
  irqchip/sifive-plic: Fixup EOI failed when masked
  irqchip/csky-mpintc: Fixup mask/unmask implementation
  PCI/MSI: Destroy sysfs before freeing entries
  PCI: Add MSI masking quirk for Nvidia ION AHCI
  PCI/MSI: Deal with devices lying about their MSI mask capability
  PCI/MSI: Move non-mask check back into low level accessors
2021-11-14 10:38:27 -08:00
Linus Torvalds
fc661f2dcb - Avoid touching ~100 config files in order to be able to select
the preemption model
 
 - clear cluster CPU masks too, on the CPU unplug path
 
 - prevent use-after-free in cfs
 
 - Prevent a race condition when updating CPU cache domains
 
 - Factor out common shared part of smp_prepare_cpus() into a common
 helper which can be called by both baremetal and Xen, in order to fix a
 booting of Xen PV guests
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Merge tag 'sched_urgent_for_v5.16_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler fixes from Borislav Petkov:

 - Avoid touching ~100 config files in order to be able to select the
   preemption model

 - clear cluster CPU masks too, on the CPU unplug path

 - prevent use-after-free in cfs

 - Prevent a race condition when updating CPU cache domains

 - Factor out common shared part of smp_prepare_cpus() into a common
   helper which can be called by both baremetal and Xen, in order to fix
   a booting of Xen PV guests

* tag 'sched_urgent_for_v5.16_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  preempt: Restore preemption model selection configs
  arch_topology: Fix missing clear cluster_cpumask in remove_cpu_topology()
  sched/fair: Prevent dead task groups from regaining cfs_rq's
  sched/core: Mitigate race cpus_share_cache()/update_top_cache_domain()
  x86/smp: Factor out parts of native_smp_prepare_cpus()
2021-11-14 09:39:03 -08:00
Linus Torvalds
f7018be292 - Prevent unintentional page sharing by checking whether a page
reference to a PMU samples page has been acquired properly before that
 
 - Make sure the LBR_SELECT MSR is saved/restored too
 
 - Reset the LBR_SELECT MSR when resetting the LBR PMU to clear any
 residual data left
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Merge tag 'perf_urgent_for_v5.16_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull perf fixes from Borislav Petkov:

 - Prevent unintentional page sharing by checking whether a page
   reference to a PMU samples page has been acquired properly before
   that

 - Make sure the LBR_SELECT MSR is saved/restored too

 - Reset the LBR_SELECT MSR when resetting the LBR PMU to clear any
   residual data left

* tag 'perf_urgent_for_v5.16_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/core: Avoid put_page() when GUP fails
  perf/x86/vlbr: Add c->flags to vlbr event constraints
  perf/x86/lbr: Reset LBR_SELECT during vlbr reset
2021-11-14 09:33:12 -08:00
Linus Torvalds
7c3737c706 Three tracing fixes:
- Make local osnoise_instances static
 
  - Copy just actual size of histogram strings
 
  - Properly check missing operands in histogram expressions
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Merge tag 'trace-v5.16-4' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

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

   - Make local osnoise_instances static

   - Copy just actual size of histogram strings

   - Properly check missing operands in histogram expressions"

* tag 'trace-v5.16-4' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing/histogram: Fix check for missing operands in an expression
  tracing/histogram: Do not copy the fixed-size char array field over the field size
  tracing/osnoise: Make osnoise_instances static
2021-11-13 10:11:51 -08:00
Kalesh Singh
1cab6bce42 tracing/histogram: Fix check for missing operands in an expression
If a binary operation is detected while parsing an expression string,
the operand strings are deduced by splitting the experssion string at
the position of the detected binary operator. Both operand strings are
sub-strings (can be empty string) of the expression string but will
never be NULL.

Currently a NULL check is used for missing operands, fix this by
checking for empty strings instead.

Link: https://lkml.kernel.org/r/20211112191324.1302505-1-kaleshsingh@google.com

Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
Fixes: 9710b2f341 ("tracing: Fix operator precedence for hist triggers expression")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-11-12 15:55:59 -05:00
Masami Hiramatsu
63f84ae6b8 tracing/histogram: Do not copy the fixed-size char array field over the field size
Do not copy the fixed-size char array field of the events over
the field size. The histogram treats char array as a string and
there are 2 types of char array in the event, fixed-size and
dynamic string. The dynamic string (__data_loc) field must be
null terminated, but the fixed-size char array field may not
be null terminated (not a string, but just a data).
In that case, histogram can copy the data after the field.
This uses the original field size for fixed-size char array
field to restrict the histogram not to access over the original
field size.

Link: https://lkml.kernel.org/r/163673292822.195747.3696966210526410250.stgit@devnote2

Fixes: 02205a6752 (tracing: Add support for 'field variables')
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-11-12 15:48:46 -05:00
Linus Torvalds
f78e9de80f Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
Pull input updates from Dmitry Torokhov:
 "Just one new driver (Cypress StreetFighter touchkey), and no input
  core changes this time.

  Plus various fixes and enhancements to existing drivers"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input: (54 commits)
  Input: iforce - fix control-message timeout
  Input: wacom_i2c - use macros for the bit masks
  Input: ili210x - reduce sample period to 15ms
  Input: ili210x - improve polled sample spacing
  Input: ili210x - special case ili251x sample read out
  Input: elantench - fix misreporting trackpoint coordinates
  Input: synaptics-rmi4 - Fix device hierarchy
  Input: i8042 - Add quirk for Fujitsu Lifebook T725
  Input: cap11xx - add support for cap1206
  Input: remove unused header <linux/input/cy8ctmg110_pdata.h>
  Input: ili210x - add ili251x firmware update support
  Input: ili210x - export ili251x version details via sysfs
  Input: ili210x - use resolution from ili251x firmware
  Input: pm8941-pwrkey - respect reboot_mode for warm reset
  reboot: export symbol 'reboot_mode'
  Input: max77693-haptic - drop unneeded MODULE_ALIAS
  Input: cpcap-pwrbutton - do not set input parent explicitly
  Input: max8925_onkey - don't mark comment as kernel-doc
  Input: ads7846 - do not attempt IRQ workaround when deferring probe
  Input: ads7846 - use input_set_capability()
  ...
2021-11-12 11:53:16 -08:00
Alexei Starovoitov
34d11a440c bpf: Fix inner map state pruning regression.
Introduction of map_uid made two lookups from outer map to be distinct.
That distinction is only necessary when inner map has an embedded timer.
Otherwise it will make the verifier state pruning to be conservative
which will cause complex programs to hit 1M insn_processed limit.
Tighten map_uid logic to apply to inner maps with timers only.

Fixes: 3e8ce29850 ("bpf: Prevent pointer mismatch in bpf_timer_init.")
Reported-by: Lorenz Bauer <lmb@cloudflare.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Lorenz Bauer <lmb@cloudflare.com>
Link: https://lore.kernel.org/bpf/CACAyw99hVEJFoiBH_ZGyy=+oO-jyydoz6v1DeKPKs2HVsUH28w@mail.gmail.com
Link: https://lore.kernel.org/bpf/20211110172556.20754-1-alexei.starovoitov@gmail.com
2021-11-12 16:19:40 +01:00
Daniel Bristot de Oliveira
d7458bc0d8 tracing/osnoise: Make osnoise_instances static
Make the struct list_head osnoise_instances definition static.

Link: https://lore.kernel.org/all/202111120052.ZuikQSJi-lkp@intel.com/
Link: https://lkml.kernel.org/r/d001f0eeac66e2b2eeec7d2a15e9e7abede0453a.1636667971.git.bristot@kernel.org

Cc: Ingo Molnar <mingo@redhat.com>
Fixes: dae181349f ("tracing/osnoise: Support a list of trace_array *tr")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-11-12 09:25:59 -05:00