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authorLinus Torvalds <torvalds@linux-foundation.org>2019-07-27 21:10:26 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2019-07-27 21:10:26 -0700
commit431f288ed730abfaca5cb73f7e0a2d04459aa65c (patch)
treef1f36fa92c4a0b9909b64afa7ae86e603fbd39aa /drivers
parent13fbe991b5b1bbb52ede39be11d5c196721349bf (diff)
parent6c11c6e3d5e9e5caf8686cd6a5e4552cfc3ea326 (diff)
Merge branch 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking fixes from Thomas Gleixner: "A set of locking fixes: - Address the fallout of the rwsem rework. Missing ACQUIREs and a sanity check to prevent a use-after-free - Add missing checks for unitialized mutexes when mutex debugging is enabled. - Remove the bogus code in the generic SMP variant of arch_futex_atomic_op_inuser() - Fixup the #ifdeffery in lockdep to prevent compile warnings" * 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: locking/mutex: Test for initialized mutex locking/lockdep: Clean up #ifdef checks locking/lockdep: Hide unused 'class' variable locking/rwsem: Add ACQUIRE comments tty/ldsem, locking/rwsem: Add missing ACQUIRE to read_failed sleep loop lcoking/rwsem: Add missing ACQUIRE to read_slowpath sleep loop locking/rwsem: Add missing ACQUIRE to read_slowpath exit when queue is empty locking/rwsem: Don't call owner_on_cpu() on read-owner futex: Cleanup generic SMP variant of arch_futex_atomic_op_inuser()
Diffstat (limited to 'drivers')
-rw-r--r--drivers/tty/tty_ldsem.c5
1 files changed, 2 insertions, 3 deletions
diff --git a/drivers/tty/tty_ldsem.c b/drivers/tty/tty_ldsem.c
index 717292c1c0df..60ff236a3d63 100644
--- a/drivers/tty/tty_ldsem.c
+++ b/drivers/tty/tty_ldsem.c
@@ -93,8 +93,7 @@ static void __ldsem_wake_readers(struct ld_semaphore *sem)
list_for_each_entry_safe(waiter, next, &sem->read_wait, list) {
tsk = waiter->task;
- smp_mb();
- waiter->task = NULL;
+ smp_store_release(&waiter->task, NULL);
wake_up_process(tsk);
put_task_struct(tsk);
}
@@ -194,7 +193,7 @@ down_read_failed(struct ld_semaphore *sem, long count, long timeout)
for (;;) {
set_current_state(TASK_UNINTERRUPTIBLE);
- if (!waiter.task)
+ if (!smp_load_acquire(&waiter.task))
break;
if (!timeout)
break;