From: Greg KH <gregkh@suse.de>
To: linux-kernel@vger.kernel.org, stable@kernel.org
Cc: Justin Forbes <jmforbes@linuxtx.org>,
Zwane Mwaikambo <zwane@arm.linux.org.uk>,
"Theodore Ts'o" <tytso@mit.edu>,
Randy Dunlap <rdunlap@xenotime.net>,
Dave Jones <davej@redhat.com>,
Chuck Wolber <chuckw@quantumlinux.com>,
Chris Wedgwood <reviews@ml.cw.f00f.org>,
Michael Krufky <mkrufky@linuxtv.org>,
Chuck Ebbert <cebbert@redhat.com>,
Domenico Andreoli <cavokz@gmail.com>,
torvalds@linux-foundation.org, akpm@linux-foundation.org,
alan@lxorguk.ukuu.org.uk, kuznet@ms2.inr.ac.ru, mingo@elte.hu,
Thomas Gleixner <tglx@linutronix.de>,
Chris Wright <chrisw@sous-sol.org>,
Greg Kroah-Hartman <gregkh@suse.de>
Subject: [patch 04/26] rt-mutex: Fix chain walk early wakeup bug
Date: Mon, 30 Jul 2007 21:31:30 -0700 [thread overview]
Message-ID: <20070731043130.GE3975@kroah.com> (raw)
In-Reply-To: <20070731043047.GA3975@kroah.com>
[-- Attachment #1: rt-mutex-fix-chain-walk-early-wakeup-bug.patch --]
[-- Type: text/plain, Size: 1325 bytes --]
-stable review patch. If anyone has any objections, please let us know.
------------------
Alexey Kuznetsov found some problems in the pi-futex code.
One of the root causes is:
When a wakeup happens, we do not to stop the chain walk so we
we follow a non existing locking chain.
Drop out when this happens.
Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
kernel/rtmutex.c | 13 +++++++++++++
1 file changed, 13 insertions(+)
--- linux-2.6.21.6.orig/kernel/rtmutex.c
+++ linux-2.6.21.6/kernel/rtmutex.c
@@ -212,6 +212,19 @@ static int rt_mutex_adjust_prio_chain(st
if (!waiter || !waiter->task)
goto out_unlock_pi;
+ /*
+ * Check the orig_waiter state. After we dropped the locks,
+ * the previous owner of the lock might have released the lock
+ * and made us the pending owner:
+ */
+ if (orig_waiter && !orig_waiter->task)
+ goto out_unlock_pi;
+
+ /*
+ * Drop out, when the task has no waiters. Note,
+ * top_waiter can be NULL, when we are in the deboosting
+ * mode!
+ */
if (top_waiter && (!task_has_pi_waiters(task) ||
top_waiter != task_top_pi_waiter(task)))
goto out_unlock_pi;
--
next prev parent reply other threads:[~2007-07-31 4:31 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20070731042108.546594256@blue.kroah.org>
2007-07-31 4:30 ` [patch 00/26] 2.6.21.7 -stable review Greg KH
2007-07-31 4:31 ` [patch 01/26] BNX2: Fix netdev watchdog on 5708 Greg KH
2007-07-31 4:31 ` [patch 02/26] sparsemem: fix oops in x86_64 show_mem Greg KH
2007-07-31 4:31 ` [patch 03/26] rt-mutex: Fix stale return value Greg KH
2007-07-31 4:31 ` Greg KH [this message]
2007-07-31 4:31 ` [patch 05/26] pi-futex: Fix exit races and locking problems Greg KH
2007-07-31 4:31 ` [patch 06/26] hpt366: disallow Ultra133 for HPT374 Greg KH
2007-07-31 4:31 ` [patch 07/26] md: Fix two raid10 bugs Greg KH
2007-07-31 4:32 ` [patch 08/26] md: Fix bug in error handling during raid1 repair Greg KH
2007-07-31 4:32 ` [patch 09/26] dm crypt: disable barriers Greg KH
2007-07-31 4:32 ` [patch 10/26] dm crypt: fix call to clone_init Greg KH
2007-07-31 4:32 ` [patch 11/26] dm crypt: fix avoid cloned bio ref after free Greg KH
2007-07-31 4:32 ` [patch 12/26] dm crypt: fix remove first_clone Greg KH
2007-07-31 4:32 ` [patch 13/26] hugetlb: fix get_policy for stacked shared memory files Greg KH
2007-07-31 4:32 ` [patch 14/26] sched: fix next_interval determination in idle_balance() Greg KH
2007-07-31 15:02 ` Paul E. McKenney
2007-07-31 4:32 ` [patch 15/26] posix-timers: Prevent softirq starvation by small intervals and SIG_IGN Greg KH
2007-07-31 4:33 ` [patch 16/26] FUTEX: Restore the dropped ERSCH fix Greg KH
2007-07-31 4:33 ` [patch 17/26] audit: fix oops removing watch if audit disabled Greg KH
2007-07-31 4:33 ` [patch 18/26] POWERPC: Fix subtle FP state corruption bug in signal return on SMP Greg KH
2007-07-31 4:33 ` [patch 19/26] mm: kill validate_anon_vma to avoid mapcount BUG Greg KH
2007-07-31 4:33 ` [patch 20/26] saa7134: fix thread shutdown handling Greg KH
2007-07-31 5:05 ` Mauro Carvalho Chehab
2007-07-31 5:16 ` Greg KH
2007-07-31 4:33 ` [patch 21/26] serial: clear proper MPSC interrupt cause bits Greg KH
2007-07-31 4:33 ` [patch 22/26] i386: fix infinite loop with singlestep int80 syscalls Greg KH
2007-07-31 4:33 ` [patch 23/26] NTP: remove clock_was_set() call to prevent deadlock Greg KH
2007-07-31 4:33 ` [patch 24/26] sky2: workaround for lost IRQ Greg KH
2007-07-31 4:33 ` [patch 25/26] V4L: bttv: fix v4l1 api usage breaking the driver Greg KH
2007-07-31 4:34 ` [patch 26/26] V4L: cx88-blackbird: fix vidioc_g_tuner never ending list of tuners Greg KH
2007-07-31 4:43 ` [patch 00/26] 2.6.21.7 -stable review Greg KH
2007-07-31 10:50 ` Stefan Richter
2007-07-31 19:47 ` Greg KH
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=20070731043130.GE3975@kroah.com \
--to=gregkh@suse.de \
--cc=akpm@linux-foundation.org \
--cc=alan@lxorguk.ukuu.org.uk \
--cc=cavokz@gmail.com \
--cc=cebbert@redhat.com \
--cc=chrisw@sous-sol.org \
--cc=chuckw@quantumlinux.com \
--cc=davej@redhat.com \
--cc=jmforbes@linuxtx.org \
--cc=kuznet@ms2.inr.ac.ru \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@elte.hu \
--cc=mkrufky@linuxtv.org \
--cc=rdunlap@xenotime.net \
--cc=reviews@ml.cw.f00f.org \
--cc=stable@kernel.org \
--cc=tglx@linutronix.de \
--cc=torvalds@linux-foundation.org \
--cc=tytso@mit.edu \
--cc=zwane@arm.linux.org.uk \
/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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).