Messages in this thread | | | Date | Fri, 20 Jan 2023 06:58:20 -0800 | Subject | Re: [PATCH] Fix data race in mark_rt_mutex_waiters | From | Arjan van de Ven <> |
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On 1/20/2023 5:55 AM, Hernan Ponce de Leon wrote: > From: Hernan Ponce de Leon <hernanl.leon@huawei.com> >
> kernel/locking/rtmutex.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c > index 010cf4e6d0b8..7ed9472edd48 100644 > --- a/kernel/locking/rtmutex.c > +++ b/kernel/locking/rtmutex.c > @@ -235,7 +235,7 @@ static __always_inline void mark_rt_mutex_waiters(struct rt_mutex_base *lock) > unsigned long owner, *p = (unsigned long *) &lock->owner; > > do { > - owner = *p; > + owner = READ_ONCE(*p); > } while (cmpxchg_relaxed(p, owner,
I don't see how this makes any difference at all. *p can be read a dozen times and it's fine; cmpxchg has barrier semantics for compilers afaics
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