locking/barriers: Convert users of lockless_dereference() to READ_ONCE()

[ Note, this is a Git cherry-pick of the following commit:

    506458efaf ("locking/barriers: Convert users of lockless_dereference() to READ_ONCE()")

  ... for easier x86 PTI code testing and back-porting. ]

READ_ONCE() now has an implicit smp_read_barrier_depends() call, so it
can be used instead of lockless_dereference() without any change in
semantics.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1508840570-22169-4-git-send-email-will.deacon@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Will Deacon
2017-10-24 11:22:48 +01:00
committed by Ingo Molnar
parent c2bc66082e
commit 3382290ed2
13 changed files with 27 additions and 27 deletions

View File

@@ -190,7 +190,7 @@ static u32 seccomp_run_filters(const struct seccomp_data *sd,
u32 ret = SECCOMP_RET_ALLOW;
/* Make sure cross-thread synced filter points somewhere sane. */
struct seccomp_filter *f =
lockless_dereference(current->seccomp.filter);
READ_ONCE(current->seccomp.filter);
/* Ensure unexpected behavior doesn't result in failing open. */
if (unlikely(WARN_ON(f == NULL)))