From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id ECA7EC433E0 for ; Tue, 16 Mar 2021 17:46:31 +0000 (UTC) Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 7A77365120 for ; Tue, 16 Mar 2021 17:46:31 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7A77365120 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=desiato.20200630; h=Sender:Content-Transfer-Encoding :Content-Type:Reply-To:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject:Cc:To:From:Date:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=l42eVYgl/18u3i6k4L6LTtGkauzUFYfTZQH3yyu/kGU=; b=KbBRCNZo7I5ZAI5WduD0+q/RZ 7YbTrPWy7JEKfjREdl9XlTUFDvDsXJjPEcSlTVvBjCKfSzpzicLe8BPJ/6YpJhwbWHscmGBgWcKri Nj7XVCitTwFXm3q2TJJfTpMq3ZHDBMZoNA6PIz/3J5AcTiGE/UfaEpFM1P/P2VAojnHpTQvYz0Z6n +AkuthBpPOoO2zQ11kUpgCt7P6YxtSNa0Xd8AaSBFAjVYdr+H+sphsEO7duJ/e+u7bGUZNcCgcPdC ZXMnx36dp+qHMNP1EXzjnEN//Iv3KdRtJ8IVykjWgxC+VNOxsBQQo7DInEe8MGnCjZLJ2YmWuBcQx AthdJfMDw==; Received: from localhost ([::1] helo=desiato.infradead.org) by desiato.infradead.org with esmtp (Exim 4.94 #2 (Red Hat Linux)) id 1lMDkF-001QdA-Ot; Tue, 16 Mar 2021 17:44:39 +0000 Received: from mail.kernel.org ([198.145.29.99]) by desiato.infradead.org with esmtps (Exim 4.94 #2 (Red Hat Linux)) id 1lMDk8-001QcU-Qu for linux-arm-kernel@lists.infradead.org; Tue, 16 Mar 2021 17:44:37 +0000 Received: by mail.kernel.org (Postfix) with ESMTPSA id 768546511D; Tue, 16 Mar 2021 17:44:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1615916671; bh=70urjVlzuIkBAAt6z/A7aEgLJGDaoFtxXpjtZaip/+I=; h=Date:From:To:Cc:Subject:Reply-To:References:In-Reply-To:From; b=RfJlUe04rO0XegYU6UvIVXzCZTbC5LlaWuudIWIYH50c1pgyq4U5a3vutog1RttNx uRcmoqxQeEjCc2raxL4arPFYnhaSQqS/lwLLDrf74yhqjbCg0kDjLqUuL9rCMlHj6S Y6LO5SAQfiSR+ThRrKq4A78hZQHl1VEaWZT+K3Ag0Hc9YgLGIm81CAz8vVl/VhTBM2 pxczDjGsHE95fM072hLdrb30mEB+jKxKuA8phptAv2uHTw+ISLr7RDtZXfTD4euFvn kwnvgkuk/T9wPBKgQCg/L9hNhAW351k4tEtDnjKsCMFkkZ8cwqQYq+DJWSoPDM+RkQ WYkPtLQfpoN9Q== Received: by paulmck-ThinkPad-P72.home (Postfix, from userid 1000) id 42827352262D; Tue, 16 Mar 2021 10:44:31 -0700 (PDT) Date: Tue, 16 Mar 2021 10:44:31 -0700 From: "Paul E. McKenney" To: Maninder Singh Cc: linux@armlinux.org.uk, cl@linux.com, penberg@kernel.org, rientjes@google.com, iamjoonsoo.kim@lge.com, akpm@linux-foundation.org, vbabka@suse.cz, 0x7f454c46@gmail.com, viro@zeniv.linux.org.uk, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, a.sahrawat@samsung.com, Vaneet Narang Subject: Re: [PATCH 1/3] mm/slub: fixing backtrace of objects because of redzone adjustment Message-ID: <20210316174431.GX2696@paulmck-ThinkPad-P72> References: <1615891032-29160-1-git-send-email-maninder1.s@samsung.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1615891032-29160-1-git-send-email-maninder1.s@samsung.com> User-Agent: Mutt/1.9.4 (2018-02-28) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210316_174435_873161_03EAF1B9 X-CRM114-Status: GOOD ( 15.84 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: paulmck@kernel.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Tue, Mar 16, 2021 at 04:07:10PM +0530, Maninder Singh wrote: > fixing commit 8e7f37f2aaa5 ("mm: Add mem_dump_obj() to print source > of memory block") > > with current code, Backtrace of allocated object is coming wrong: > / # cat /proc/meminfo > [ 14.969843] slab kmalloc-64 start c8ab0140 data offset 64 pointer offset 0 size 64 allocated at 0x6b6b6b6b > [ 14.970635] 0x6b6b6b6b > [ 14.970794] 0x6b6b6b6b > [ 14.970932] 0x6b6b6b6b > [ 14.971077] 0x6b6b6b6b > [ 14.971202] 0x6b6b6b6b > [ 14.971317] 0x6b6b6b6b > [ 14.971423] 0x6b6b6b6b > [ 14.971635] 0x6b6b6b6b > [ 14.971740] 0x6b6b6b6b > [ 14.971871] 0x6b6b6b6b > [ 14.972229] 0x6b6b6b6b > [ 14.972363] 0x6b6b6b6b > [ 14.972505] 0xa56b6b6b > [ 14.972631] 0xbbbbbbbb > [ 14.972734] 0xc8ab0400 > [ 14.972891] meminfo_proc_show+0x40/0x4fc > > And reason is red zone was not adjusted from object address. > after adding fixup for redzone, backtrace is coming correct: > / # cat /proc/meminfo > [ 14.870782] slab kmalloc-64 start c8ab0140 data offset 64 pointer offset 128 size 64 allocated at meminfo_proc_show+0x40/0x4f4 > [ 14.871817] meminfo_proc_show+0x40/0x4f4 > [ 14.872035] seq_read_iter+0x18c/0x4c4 > [ 14.872229] proc_reg_read_iter+0x84/0xac > [ 14.872433] generic_file_splice_read+0xe8/0x17c > [ 14.872621] splice_direct_to_actor+0xb8/0x290 > [ 14.872747] do_splice_direct+0xa0/0xe0 > [ 14.872896] do_sendfile+0x2d0/0x438 > [ 14.873044] sys_sendfile64+0x12c/0x140 > [ 14.873229] ret_fast_syscall+0x0/0x58 > [ 14.873372] 0xbe861de4 > > Signed-off-by: Vaneet Narang > Signed-off-by: Maninder Singh Good catch, thank you! For the series: Acked-by: Paul E. McKenney On the other hand, if you would like me to take these, we need to get a maintainer ack. Thanx, Paul > --- > mm/slub.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/mm/slub.c b/mm/slub.c > index 1912c4614248..9d13f0117ae6 100644 > --- a/mm/slub.c > +++ b/mm/slub.c > @@ -4052,6 +4052,7 @@ void kmem_obj_info(struct kmem_obj_info *kpp, void *object, struct page *page) > !(s->flags & SLAB_STORE_USER)) > return; > #ifdef CONFIG_SLUB_DEBUG > + objp = fixup_red_left(s, objp); > trackp = get_track(s, objp, TRACK_ALLOC); > kpp->kp_ret = (void *)trackp->addr; > #ifdef CONFIG_STACKTRACE > -- > 2.17.1 > _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel