diff options
| author | Will Deacon <will.deacon@arm.com> | 2017-10-24 11:22:48 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2017-12-17 13:57:15 +0100 |
| commit | 3382290ed2d5e275429cef510ab21889d3ccd164 (patch) | |
| tree | 0993c387956cf3b6f802acf12a62b79cb94ece1a /kernel | |
| parent | c2bc66082e1048c7573d72e62f597bdc5ce13fea (diff) | |
| download | op-kernel-dev-3382290ed2d5e275429cef510ab21889d3ccd164.zip op-kernel-dev-3382290ed2d5e275429cef510ab21889d3ccd164.tar.gz | |
locking/barriers: Convert users of lockless_dereference() to READ_ONCE()
[ Note, this is a Git cherry-pick of the following commit:
506458efaf15 ("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>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/events/core.c | 4 | ||||
| -rw-r--r-- | kernel/seccomp.c | 2 | ||||
| -rw-r--r-- | kernel/task_work.c | 2 |
3 files changed, 4 insertions, 4 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c index 10cdb9c..6eee4ed 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -4233,7 +4233,7 @@ static void perf_remove_from_owner(struct perf_event *event) * indeed free this event, otherwise we need to serialize on * owner->perf_event_mutex. */ - owner = lockless_dereference(event->owner); + owner = READ_ONCE(event->owner); if (owner) { /* * Since delayed_put_task_struct() also drops the last @@ -4330,7 +4330,7 @@ again: * Cannot change, child events are not migrated, see the * comment with perf_event_ctx_lock_nested(). */ - ctx = lockless_dereference(child->ctx); + ctx = READ_ONCE(child->ctx); /* * Since child_mutex nests inside ctx::mutex, we must jump * through hoops. We start by grabbing a reference on the ctx. diff --git a/kernel/seccomp.c b/kernel/seccomp.c index 418a1c0..5f0dfb2ab 100644 --- a/kernel/seccomp.c +++ b/kernel/seccomp.c @@ -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))) diff --git a/kernel/task_work.c b/kernel/task_work.c index 5718b3e..0fef395 100644 --- a/kernel/task_work.c +++ b/kernel/task_work.c @@ -68,7 +68,7 @@ task_work_cancel(struct task_struct *task, task_work_func_t func) * we raced with task_work_run(), *pprev == NULL/exited. */ raw_spin_lock_irqsave(&task->pi_lock, flags); - while ((work = lockless_dereference(*pprev))) { + while ((work = READ_ONCE(*pprev))) { if (work->func != func) pprev = &work->next; else if (cmpxchg(pprev, work, work->next) == work) |
