linux-stable.git/kernel/locking, branch v5.10.22

locking/lockdep: Avoid unmatched unlock

2021-03-04T10:37:47+00:00

[ Upstream commit 7f82e631d236cafd28518b998c6d4d8dc2ef68f6 ]

Commit f6f48e180404 ("lockdep: Teach lockdep about "USED" <- "IN-NMI"
inversions") overlooked that print_usage_bug() releases the graph_lock
and called it without the graph lock held.

Fixes: f6f48e180404 ("lockdep: Teach lockdep about "USED" <- "IN-NMI" inversions")
Reported-by: Dmitry Vyukov 
Signed-off-by: Peter Zijlstra (Intel) 
Acked-by: Waiman Long 
Link: https://lkml.kernel.org/r/YBfkuyIfB1+VRxXP@hirez.programming.kicks-ass.net
Signed-off-by: Sasha Levin

locking/lockdep: Avoid noinstr warning for DEBUG_LOCKDEP

2021-02-07T14:37:14+00:00

[ Upstream commit 77ca93a6b1223e210e58e1000c09d8d420403c94 ]

  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) 
Signed-off-by: Thomas Gleixner 
Link: https://lore.kernel.org/r/20210106144017.652218215@infradead.org
Signed-off-by: Sasha Levin

rtmutex: Remove unused argument from rt_mutex_proxy_unlock()

2021-01-30T12:55:17+00:00

commit 2156ac1934166d6deb6cd0f6ffc4c1076ec63697 upstream

Nothing uses the argument. Remove it as preparation to use
pi_state_update_owner().

Signed-off-by: Thomas Gleixner 
Acked-by: Peter Zijlstra (Intel) 
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman

locking/lockdep: Cure noinstr fail

2021-01-27T10:55:21+00:00

commit 0afda3a888dccf12557b41ef42eee942327d122b upstream.

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: 4d004099a668 ("lockdep: Fix lockdep recursion")
Reported-by: Randy Dunlap 
Signed-off-by: Peter Zijlstra (Intel) 
Signed-off-by: Thomas Gleixner 
Link: https://lore.kernel.org/r/20210106144017.592595176@infradead.org
Signed-off-by: Greg Kroah-Hartman

rwsem: Implement down_read_interruptible

2021-01-09T12:46:24+00:00

[ Upstream commit 31784cff7ee073b34d6eddabb95e3be2880a425c ]

In preparation for converting exec_update_mutex to a rwsem so that
multiple readers can execute in parallel and not deadlock, add
down_read_interruptible.  This is needed for perf_event_open to be
converted (with no semantic changes) from working on a mutex to
wroking on a rwsem.

Signed-off-by: Eric W. Biederman 
Signed-off-by: Peter Zijlstra (Intel) 
Link: https://lkml.kernel.org/r/87k0tybqfy.fsf@x220.int.ebiederm.org
Signed-off-by: Sasha Levin

rwsem: Implement down_read_killable_nested

2021-01-09T12:46:24+00:00

[ Upstream commit 0f9368b5bf6db0c04afc5454b1be79022a681615 ]

In preparation for converting exec_update_mutex to a rwsem so that
multiple readers can execute in parallel and not deadlock, add
down_read_killable_nested.  This is needed so that kcmp_lock
can be converted from working on a mutexes to working on rw_semaphores.

Signed-off-by: Eric W. Biederman 
Signed-off-by: Peter Zijlstra (Intel) 
Link: https://lkml.kernel.org/r/87o8jabqh3.fsf@x220.int.ebiederm.org
Signed-off-by: Sasha Levin

lockdep: Put graph lock/unlock under lock_recursion protection

2020-11-17T12:15:35+00:00

A warning was hit when running xfstests/generic/068 in a Hyper-V guest:

[...] ------------[ cut here ]------------
[...] DEBUG_LOCKS_WARN_ON(lockdep_hardirqs_enabled())
[...] WARNING: CPU: 2 PID: 1350 at kernel/locking/lockdep.c:5280 check_flags.part.0+0x165/0x170
[...] ...
[...] Workqueue: events pwq_unbound_release_workfn
[...] RIP: 0010:check_flags.part.0+0x165/0x170
[...] ...
[...] Call Trace:
[...]  lock_is_held_type+0x72/0x150
[...]  ? lock_acquire+0x16e/0x4a0
[...]  rcu_read_lock_sched_held+0x3f/0x80
[...]  __send_ipi_one+0x14d/0x1b0
[...]  hv_send_ipi+0x12/0x30
[...]  __pv_queued_spin_unlock_slowpath+0xd1/0x110
[...]  __raw_callee_save___pv_queued_spin_unlock_slowpath+0x11/0x20
[...]  .slowpath+0x9/0xe
[...]  lockdep_unregister_key+0x128/0x180
[...]  pwq_unbound_release_workfn+0xbb/0xf0
[...]  process_one_work+0x227/0x5c0
[...]  worker_thread+0x55/0x3c0
[...]  ? process_one_work+0x5c0/0x5c0
[...]  kthread+0x153/0x170
[...]  ? __kthread_bind_mask+0x60/0x60
[...]  ret_from_fork+0x1f/0x30

The cause of the problem is we have call chain lockdep_unregister_key()
->  lockdep_unlock() ->
arch_spin_unlock() -> __pv_queued_spin_unlock_slowpath() -> pv_kick() ->
__send_ipi_one() -> trace_hyperv_send_ipi_one().

Although this particular warning is triggered because Hyper-V has a
trace point in ipi sending, but in general arch_spin_unlock() may call
another function having a trace point in it, so put the arch_spin_lock()
and arch_spin_unlock() after lock_recursion protection to fix this
problem and avoid similiar problems.

Signed-off-by: Boqun Feng 
Signed-off-by: Peter Zijlstra (Intel) 
Link: https://lkml.kernel.org/r/20201113110512.1056501-1-boqun.feng@gmail.com

lockdep: Avoid to modify chain keys in validate_chain()

2020-11-10T17:38:38+00:00

Chris Wilson reported a problem spotted by check_chain_key(): a chain
key got changed in validate_chain() because we modify the ->read in
validate_chain() to skip checks for dependency adding, and ->read is
taken into calculation for chain key since commit f611e8cf98ec
("lockdep: Take read/write status in consideration when generate
chainkey").

Fix this by avoiding to modify ->read in validate_chain() based on two
facts: a) since we now support recursive read lock detection, there is
no need to skip checks for dependency adding for recursive readers, b)
since we have a), there is only one case left (nest_lock) where we want
to skip checks in validate_chain(), we simply remove the modification
for ->read and rely on the return value of check_deadlock() to skip the
dependency adding.

Reported-by: Chris Wilson 
Signed-off-by: Boqun Feng 
Signed-off-by: Peter Zijlstra (Intel) 
Link: https://lkml.kernel.org/r/20201102053743.450459-1-boqun.feng@gmail.com

Merge tag 'locking-urgent-2020-11-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2020-11-01T19:08:17+00:00

Pull locking fixes from Thomas Gleixner:
 "A couple of locking fixes:

   - Fix incorrect failure injection handling in the fuxtex code

   - Prevent a preemption warning in lockdep when tracking
     local_irq_enable() and interrupts are already enabled

   - Remove more raw_cpu_read() usage from lockdep which causes state
     corruption on !X86 architectures.

   - Make the nr_unused_locks accounting in lockdep correct again"

* tag 'locking-urgent-2020-11-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  lockdep: Fix nr_unused_locks accounting
  locking/lockdep: Remove more raw_cpu_read() usage
  futex: Fix incorrect should_fail_futex() handling
  lockdep: Fix preemption WARN for spurious IRQ-enable

lockdep: Fix nr_unused_locks accounting

2020-10-30T16:07:18+00:00

Chris reported that commit 24d5a3bffef1 ("lockdep: Fix
usage_traceoverflow") breaks the nr_unused_locks validation code
triggered by /proc/lockdep_stats.

By fully splitting LOCK_USED and LOCK_USED_READ it becomes a bad
indicator for accounting nr_unused_locks; simplyfy by using any first
bit.

Fixes: 24d5a3bffef1 ("lockdep: Fix usage_traceoverflow")
Reported-by: Chris Wilson 
Signed-off-by: Peter Zijlstra (Intel) 
Tested-by: Chris Wilson 
Link: https://lkml.kernel.org/r/20201027124834.GL2628@hirez.programming.kicks-ass.net