Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756082Ab0D1Rq4 (ORCPT ); Wed, 28 Apr 2010 13:46:56 -0400 Received: from mail.openrapids.net ([64.15.138.104]:53505 "EHLO blackscsi.openrapids.net" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754850Ab0D1Rqz (ORCPT ); Wed, 28 Apr 2010 13:46:55 -0400 Date: Wed, 28 Apr 2010 13:46:54 -0400 From: Mathieu Desnoyers To: Greg KH , Tejun Heo Cc: linux-kernel@vger.kernel.org, stable@kernel.org, Greg KH , stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Randy Dunlap , Eric Dumazet , Rusty Russell , Peter Zijlstra , Ingo Molnar , Steven Rostedt Subject: Re: [170/197] lockdep: fix incorrect percpu usage Message-ID: <20100428174653.GB4205@Krystal> References: <20100422191857.GA13268@kroah.com> <20100422190922.618832798@kvm.kroah.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100422190922.618832798@kvm.kroah.org> X-Editor: vi X-Info: http://www.efficios.com X-Operating-System: Linux/2.6.26-2-686 (i686) X-Uptime: 13:46:05 up 95 days, 20:23, 7 users, load average: 0.02, 0.02, 0.00 User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2605 Lines: 80 * Greg KH (gregkh@suse.de) wrote: > 2.6.32-stable review patch. If anyone has any objections, please let us know. > > ------------------ > > From: Mathieu Desnoyers > > The mainline kernel as of 2.6.34-rc5 is not affected by this problem because > commit 10fad5e46f6c7bdfb01b1a012380a38e3c6ab346 fixed it by refactoring. > > lockdep fix incorrect percpu usage > > Should use per_cpu_ptr() to obfuscate the per cpu pointers (RELOC_HIDE is needed > for per cpu pointers). > > git blame points to commit: > > lockdep.c: commit 8e18257d29238311e82085152741f0c3aa18b74d > > But it's really just moving the code around. But it's enough to say that the > problems appeared before Jul 19 01:48:54 2007, which brings us back to 2.6.23. > > It should be applied to stable 2.6.23.x to 2.6.33.x (or whichever of these > stable branches are still maintained). Tejun, (same as module.c patch) should this patch be applied to 2.6.32.x, or will it cause problems on ia64 ? Thanks, Mathieu > > (tested on 2.6.33.1 x86_64) > > Signed-off-by: Mathieu Desnoyers > CC: Randy Dunlap > CC: Eric Dumazet > CC: Rusty Russell > CC: Peter Zijlstra > CC: Tejun Heo > CC: Ingo Molnar > CC: Andrew Morton > CC: Linus Torvalds > CC: Greg Kroah-Hartman > CC: Steven Rostedt > Signed-off-by: Greg Kroah-Hartman > > --- > kernel/lockdep.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > --- a/kernel/lockdep.c > +++ b/kernel/lockdep.c > @@ -591,9 +591,9 @@ static int static_obj(void *obj) > * percpu var? > */ > for_each_possible_cpu(i) { > - start = (unsigned long) &__per_cpu_start + per_cpu_offset(i); > - end = (unsigned long) &__per_cpu_start + PERCPU_ENOUGH_ROOM > - + per_cpu_offset(i); > + start = (unsigned long) per_cpu_ptr(&__per_cpu_start, i); > + end = (unsigned long) per_cpu_ptr(&__per_cpu_start > + + PERCPU_ENOUGH_ROOM, i); > > if ((addr >= start) && (addr < end)) > return 1; > > -- Mathieu Desnoyers Operating System Efficiency R&D Consultant EfficiOS Inc. http://www.efficios.com -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/