From: Darren Hart <dvhltc@us.ibm.com>
To: mingo@redhat.com, hpa@zytor.com, linux-kernel@vger.kernel.org,
tglx@linutronix.de, mingo@elte.hu
Cc: linux-tip-commits@vger.kernel.org
Subject: Re: [tip:core/futexes] futex: remove the pointer math from double_unlock_hb, fix
Date: Fri, 13 Mar 2009 08:03:43 -0700 [thread overview]
Message-ID: <49BA75CF.3040501@us.ibm.com> (raw)
In-Reply-To: <tip-88f502fedba82eff252b6420e8b8328e4ae25c67@git.kernel.org>
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
prev parent reply other threads:[~2009-03-13 15:04 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-03-12 22:11 [PATCH] futex: remove the pointer math from double_unlock_hb Darren Hart
2009-03-13 0:18 ` [tip:core/futexes] " Darren Hart
2009-03-13 9:26 ` [PATCH] " Thomas Gleixner
2009-03-13 9:36 ` [tip:core/futexes] futex: remove the pointer math from double_unlock_hb, fix Ingo Molnar
2009-03-13 15:03 ` Darren Hart [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=49BA75CF.3040501@us.ibm.com \
--to=dvhltc@us.ibm.com \
--cc=hpa@zytor.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-tip-commits@vger.kernel.org \
--cc=mingo@elte.hu \
--cc=mingo@redhat.com \
--cc=tglx@linutronix.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.