Messages in this thread | | | Date | Fri, 13 Mar 2009 08:03:43 -0700 | From | Darren Hart <> | Subject | Re: [tip:core/futexes] futex: remove the pointer math from double_unlock_hb, fix |
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Ingo Molnar wrote: > Commit-ID: 88f502fedba82eff252b6420e8b8328e4ae25c67 > Gitweb: http://git.kernel.org/tip/88f502fedba82eff252b6420e8b8328e4ae25c67 > Author: Ingo Molnar <mingo@elte.hu> > AuthorDate: Fri, 13 Mar 2009 10:32:07 +0100 > Commit: Ingo Molnar <mingo@elte.hu> > CommitDate: Fri, 13 Mar 2009 10:32:07 +0100 > > futex: remove the pointer math from double_unlock_hb, fix > > Impact: fix double unlock crash > > Thomas Gleixner noticed that the simplified double_unlock_hb() > became ... too unsophisticated: in the hb1 == hb2 case it will > do a double unlock.
Gah. Thanks for catching it.
> > Reported-by: Thomas Gleixner <tglx@linutronix.de> > Cc: Darren Hart <dvhltc@us.ibm.com> > LKML-Reference: <20090312221118.11146.68610.stgit@Aeon> > Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Darren Hart <dvhltc@us.ibm.com>
> > > --- > kernel/futex.c | 3 ++- > 1 files changed, 2 insertions(+), 1 deletions(-) > > diff --git a/kernel/futex.c b/kernel/futex.c > index 2331b73..6b50a02 100644 > --- a/kernel/futex.c > +++ b/kernel/futex.c > @@ -659,7 +659,8 @@ static inline void > double_unlock_hb(struct futex_hash_bucket *hb1, struct futex_hash_bucket *hb2) > { > spin_unlock(&hb1->lock); > - spin_unlock(&hb2->lock); > + if (hb1 != hb2) > + spin_unlock(&hb2->lock); > } > > /*
-- Darren Hart IBM Linux Technology Center Real-Time Linux Team
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