Messages in this thread Patch in this message | | | From | Kent Overstreet <> | Subject | [PATCH 12/12] closures: fix a race on wakeup from closure_sync | Date | Mon, 10 Jun 2019 15:14:20 -0400 |
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Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com> --- lib/closure.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/lib/closure.c b/lib/closure.c index 46cfe4c382..3e6366c262 100644 --- a/lib/closure.c +++ b/lib/closure.c @@ -104,8 +104,14 @@ struct closure_syncer { static void closure_sync_fn(struct closure *cl) { - cl->s->done = 1; - wake_up_process(cl->s->task); + struct closure_syncer *s = cl->s; + struct task_struct *p; + + rcu_read_lock(); + p = READ_ONCE(s->task); + s->done = 1; + wake_up_process(p); + rcu_read_unlock(); } void __sched __closure_sync(struct closure *cl) -- 2.20.1
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