From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1764101AbYD0UzD (ORCPT ); Sun, 27 Apr 2008 16:55:03 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751109AbYD0Uyy (ORCPT ); Sun, 27 Apr 2008 16:54:54 -0400 Received: from bombadil.infradead.org ([18.85.46.34]:35117 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751058AbYD0Uyx (ORCPT ); Sun, 27 Apr 2008 16:54:53 -0400 Subject: Re: + mutex-debug-check-mutex-magic-before-owner.patch added to -mm tree From: Peter Zijlstra To: akpm@linux-foundation.org Cc: linux-kernel , jk@ozlabs.org, mingo@elte.hu In-Reply-To: <200804272047.m3RKlMgY024122@imap1.linux-foundation.org> References: <200804272047.m3RKlMgY024122@imap1.linux-foundation.org> Content-Type: text/plain Date: Sun, 27 Apr 2008 22:54:37 +0200 Message-Id: <1209329677.6429.0.camel@lappy> Mime-Version: 1.0 X-Mailer: Evolution 2.22.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, 2008-04-27 at 13:47 -0700, akpm@linux-foundation.org wrote: > The patch titled > mutex-debug: check mutex magic before owner > has been added to the -mm tree. Its filename is > mutex-debug-check-mutex-magic-before-owner.patch > > Before you just go and hit "reply", please: > a) Consider who else should be cc'ed > b) Prefer to cc a suitable mailing list as well > c) Ideally: find the original patch on the mailing list and do a > reply-to-all to that, adding suitable additional cc's > > *** Remember to use Documentation/SubmitChecklist when testing your code *** > > See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find > out what to do about this > > The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ > > ------------------------------------------------------ > Subject: mutex-debug: check mutex magic before owner > From: Jeremy Kerr > > Currently, the mutex debug code checks the lock->owner before lock->magic, so > a corrupt mutex will most likely result in failing the owner check, rather > than the magic check. > > This change to debug_mutex_unlock does the magic check first, so > we have a better idea of what breaks. > > Signed-off-by: Jeremy Kerr > Cc: Peter Zijlstra Acked-by; Peter Zijlstra > Cc: Ingo Molnar > Signed-off-by: Andrew Morton > --- > > kernel/mutex-debug.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff -puN kernel/mutex-debug.c~mutex-debug-check-mutex-magic-before-owner kernel/mutex-debug.c > --- a/kernel/mutex-debug.c~mutex-debug-check-mutex-magic-before-owner > +++ a/kernel/mutex-debug.c > @@ -79,8 +79,8 @@ void debug_mutex_unlock(struct mutex *lo > if (unlikely(!debug_locks)) > return; > > - DEBUG_LOCKS_WARN_ON(lock->owner != current_thread_info()); > DEBUG_LOCKS_WARN_ON(lock->magic != lock); > + DEBUG_LOCKS_WARN_ON(lock->owner != current_thread_info()); > DEBUG_LOCKS_WARN_ON(!lock->wait_list.prev && !lock->wait_list.next); > DEBUG_LOCKS_WARN_ON(lock->owner != current_thread_info()); > } > _ > > Patches currently in -mm which might be from jk@ozlabs.org are > > origin.patch > mutex-debug-check-mutex-magic-before-owner.patch >