From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751881AbZH2Nan (ORCPT ); Sat, 29 Aug 2009 09:30:43 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751427AbZH2Nam (ORCPT ); Sat, 29 Aug 2009 09:30:42 -0400 Received: from mx3.mail.elte.hu ([157.181.1.138]:54956 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751183AbZH2Nam (ORCPT ); Sat, 29 Aug 2009 09:30:42 -0400 Date: Sat, 29 Aug 2009 15:29:54 +0200 From: Ingo Molnar To: Catalin Marinas Cc: x86@kernel.org, linux-kernel@vger.kernel.org, Ingo Molnar Subject: Re: [PATCH 1/2] kmemleak: Inform kmemleak about kernel stack allocation Message-ID: <20090829132954.GB24123@elte.hu> References: <20090827165927.27901.97270.stgit@pc1117.cambridge.arm.com> <20090827170253.27901.33997.stgit@pc1117.cambridge.arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090827170253.27901.33997.stgit@pc1117.cambridge.arm.com> User-Agent: Mutt/1.5.18 (2008-05-17) X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.5 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Catalin Marinas wrote: > Traversing all the tasks in the system for scanning the kernel > stacks requires locking which increases the kernel latency > considerably. This patch informs kmemleak about newly allocated or > freed stacks so that they are treated as any other allocated > object. Subsequent patch will remove the explicit stack scanning > from mm/kmemleak.c. > > Signed-off-by: Catalin Marinas > Cc: Ingo Molnar > --- > arch/x86/include/asm/thread_info.h | 7 ++++++- > arch/x86/kernel/process.c | 2 ++ > kernel/fork.c | 7 ++++++- > 3 files changed, 14 insertions(+), 2 deletions(-) > > diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thread_info.h > index fad7d40..f26432a 100644 > --- a/arch/x86/include/asm/thread_info.h > +++ b/arch/x86/include/asm/thread_info.h > @@ -162,7 +162,12 @@ struct thread_info { > #define __HAVE_ARCH_THREAD_INFO_ALLOCATOR > > #define alloc_thread_info(tsk) \ > - ((struct thread_info *)__get_free_pages(THREAD_FLAGS, THREAD_ORDER)) > +({ \ > + struct thread_info *ti = (struct thread_info *) \ > + __get_free_pages(THREAD_FLAGS, THREAD_ORDER); \ > + kmemleak_alloc(ti, THREAD_SIZE, 1, THREAD_FLAGS); \ > + ti; \ > +}) Sidenote:this used to be a trivial wrapper to gfp so it was borderline OK as a CPP macro - now it's a non-trivial CPP wrapper macro which is not OK. Mind converting it to an inline function? Ingo