From patchwork Wed Feb 5 00:46:12 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hyesoo Yu X-Patchwork-Id: 13960264 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6D001C02193 for ; Wed, 5 Feb 2025 00:47:50 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id F303628000C; Tue, 4 Feb 2025 19:47:49 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id EE00428000B; Tue, 4 Feb 2025 19:47:49 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id D593828000C; Tue, 4 Feb 2025 19:47:49 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id B7C9F28000B for ; Tue, 4 Feb 2025 19:47:49 -0500 (EST) Received: from smtpin08.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id 3610B1C708C for ; Wed, 5 Feb 2025 00:47:49 +0000 (UTC) X-FDA: 83084053458.08.A564EEA Received: from mailout1.samsung.com (mailout1.samsung.com [203.254.224.24]) by imf24.hostedemail.com (Postfix) with ESMTP id 3AC37180014 for ; Wed, 5 Feb 2025 00:47:45 +0000 (UTC) Authentication-Results: imf24.hostedemail.com; dkim=pass header.d=samsung.com header.s=mail20170921 header.b=ibK63bsy; spf=pass (imf24.hostedemail.com: domain of hyesoo.yu@samsung.com designates 203.254.224.24 as permitted sender) smtp.mailfrom=hyesoo.yu@samsung.com; dmarc=pass (policy=none) header.from=samsung.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1738716466; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding:in-reply-to: references:references:dkim-signature; bh=uwDTXPOl/iFjYULcYF/gvbwf7NyMWagWNtqOiYY00EA=; b=RD4KPo57QHbTBlhmBBy2HxJsMXmE9h0USPG+TATSoFx4l56aUrDDF/ju9AW1+YOeTguZEu YZbHHT6tbPZl2Mq4fjaTCgfwK8ulOSGjP5nNOZYHwluE0dJhExrK5kcpp+kdTQwojmW/yP W9TaOr9sNb7U8Wk9sVWLeC81mUHVbuU= ARC-Authentication-Results: i=1; imf24.hostedemail.com; dkim=pass header.d=samsung.com header.s=mail20170921 header.b=ibK63bsy; spf=pass (imf24.hostedemail.com: domain of hyesoo.yu@samsung.com designates 203.254.224.24 as permitted sender) smtp.mailfrom=hyesoo.yu@samsung.com; dmarc=pass (policy=none) header.from=samsung.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1738716466; a=rsa-sha256; cv=none; b=FSuORJ3pO8xRkj9niFFWLLWjrIIm/JJJNIpfOqWj4Dit/WFKVN+LVth/LPc5BKXaomAEXn e/g9vSt35GpZ/crsUzdSea89mzZddi9aIKUNVo/276ykPT8kpUWOa+DzkL+Br2ptJskVDy 8WyP1cwwG+KFCif+Nvc3gPJe5Em0fvs= Received: from epcas2p3.samsung.com (unknown [182.195.41.55]) by mailout1.samsung.com (KnoxPortal) with ESMTP id 20250205004742epoutp019c140d2cb09ac631ba27900f6fd876cb~hKWkpNJnw2063620636epoutp01W for ; Wed, 5 Feb 2025 00:47:42 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 mailout1.samsung.com 20250205004742epoutp019c140d2cb09ac631ba27900f6fd876cb~hKWkpNJnw2063620636epoutp01W DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=samsung.com; s=mail20170921; t=1738716462; bh=uwDTXPOl/iFjYULcYF/gvbwf7NyMWagWNtqOiYY00EA=; h=From:To:Cc:Subject:Date:References:From; b=ibK63bsynu60PQbF5YpapB/z31ysnb7D/fYhhC63NkCUEgLkbkr+dOAK15HJQCtSl KJIkjhDDcV85GzIGu8UWaACrWgncZGQJ4dESWrdmshsS93ZVPm9XagZ/Yh79kelLYj SbkJwBoNQ6JdlvSR2ha2TJpSbVUVRXPPiMpS+tO0= Received: from epsnrtp1.localdomain (unknown [182.195.42.162]) by epcas2p3.samsung.com (KnoxPortal) with ESMTP id 20250205004742epcas2p39369e1aeaa917b4f574edd9f2ae100b9~hKWkWU-cn0090700907epcas2p3W; Wed, 5 Feb 2025 00:47:42 +0000 (GMT) Received: from epsmges2p4.samsung.com (unknown [182.195.36.99]) by epsnrtp1.localdomain (Postfix) with ESMTP id 4YnhR16Wbzz4x9Q7; Wed, 5 Feb 2025 00:47:41 +0000 (GMT) Received: from epcas2p2.samsung.com ( [182.195.41.54]) by epsmges2p4.samsung.com (Symantec Messaging Gateway) with SMTP id 79.45.22094.D25B2A76; Wed, 5 Feb 2025 09:47:41 +0900 (KST) Received: from epsmtrp1.samsung.com (unknown [182.195.40.13]) by epcas2p3.samsung.com (KnoxPortal) with ESMTPA id 20250205004741epcas2p3081bc2c97b7c1c27a9797cd498c4bc64~hKWjJN-sv0319703197epcas2p3p; Wed, 5 Feb 2025 00:47:41 +0000 (GMT) Received: from epsmgms1p1new.samsung.com (unknown [182.195.42.41]) by epsmtrp1.samsung.com (KnoxPortal) with ESMTP id 20250205004741epsmtrp117728312c8a0ae238979b29757a011f5~hKWjIeT1j0427704277epsmtrp1F; Wed, 5 Feb 2025 00:47:41 +0000 (GMT) X-AuditID: b6c32a48-e7eec7000000564e-e1-67a2b52dec1a Received: from epsmtip1.samsung.com ( [182.195.34.30]) by epsmgms1p1new.samsung.com (Symantec Messaging Gateway) with SMTP id BF.3D.18729.C25B2A76; Wed, 5 Feb 2025 09:47:41 +0900 (KST) Received: from localhost.localdomain (unknown [10.229.95.142]) by epsmtip1.samsung.com (KnoxPortal) with ESMTPA id 20250205004740epsmtip17daa410f5afdbcd7fc5f9c8b425d615d~hKWi5gr0X1698316983epsmtip1j; Wed, 5 Feb 2025 00:47:40 +0000 (GMT) From: Hyesoo Yu To: Cc: janghyuck.kim@samsung.com, Hyesoo Yu , Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , Andrew Morton , Vlastimil Babka , Roman Gushchin , Hyeonggon Yoo <42.hyeyoo@gmail.com>, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH v2] mm: slub: call WARN() instead of pr_err on slab_fix. Date: Wed, 5 Feb 2025 09:46:12 +0900 Message-ID: <20250205004615.1253389-1-hyesoo.yu@samsung.com> X-Mailer: git-send-email 2.48.0 MIME-Version: 1.0 X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFtrMJsWRmVeSWpSXmKPExsWy7bCmma7u1kXpBptuGFlM7DGwmLN+DZvF 9W9vGC3+dl5gtVjZ3cxmsXlOscXlXXPYLO6t+c9q0fb5H5BYspHJYuIaUYvZjX2MDjweO2fd ZfdYsKnUY9OqTjaPTZ8msXt0vb3C5HFixm8WjydXpjN5LGyYyuzRt2UVo8eZBUfYPT5vkgvg jsq2yUhNTEktUkjNS85PycxLt1XyDo53jjc1MzDUNbS0MFdSyEvMTbVVcvEJ0HXLzAG6XEmh LDGnFCgUkFhcrKRvZ1OUX1qSqpCRX1xiq5RakJJTYF6gV5yYW1yal66Xl1piZWhgYGQKVJiQ nXHixS3GggkiFTOurWRuYPzK38XIySEhYCLRtvItUxcjF4eQwA5GiWfTH7FBOJ8YJY7s+gmV +cYo8aJ5BQtMy/03X9khEnsZJY5/ncgM4XxmlHg/t58JpIpNQF3ixJZljCC2iACLxMrv38G6 mQVWMUv0vjAHsYUFPCReb7vADGKzCKhK7H78mg3E5hWwkdj1+CUTxDZ5idtrTrJAxAUlTs58 AjVHXqJ562ywxRICMzkkNq2axgbR4CJxbt51qGZhiVfHt7BD2FISL/vboOxiiW2LDzNBNDcw SmzuuM8MkTCWmPWsHehqDqANmhLrd+mDmBICyhJHbkHt5ZPoOPyXHSLMK9HRJgTRqCyxf9k8 aABJSjxa284KYXtIHJn9DewyIYFYifX/D7FNYJSfheSbWUi+mYWwdwEj8ypGsdSC4tz01GKj AhN4rCbn525iBKdeLY8djLPfftA7xMjEwXiIUYKDWUmE9/T2BelCvCmJlVWpRfnxRaU5qcWH GE2B4TuRWUo0OR+Y/PNK4g1NLA1MzMwMzY1MDcyVxHmrd7SkCwmkJ5akZqemFqQWwfQxcXBK NTBFTc0/wcng9OyGgWCS4Ord/JVdPFHms2VYLt5RvZVtU8a3XOn4z2imtiLmZSm5kgmVlnW5 s5s+HEgsPTZp3z2P4Cj9kocP2K7oCrN/8jsjbfb59Sb/A3/PXbol8EqBc4XZIqaj031urmhI V2xMCb/oVBuZ2JA5Y0/AcpPUP/c+hr0/kn5QfmkqR0gq/5dze067Sc8NOXdH/9kr0WDNO/fq r8Qav9o0ueABo8/VmndZ4leOWptHxmx9dSvzXF5hyMy/AR/M48s6z54/9fpSkqeAy1GvhWbB 09/N+PDOn3nN/b0H6ir5E691l5tPs8iUWWKwYXeGnmeb3i8t57/GwoZxn7sNg5ZweWvdWRJV +U6JpTgj0VCLuag4EQB8SLG2RgQAAA== X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFnrMLMWRmVeSWpSXmKPExsWy7bCSnK7u1kXpBjuPMVpM7DGwmLN+DZvF 9W9vGC3+dl5gtVjZ3cxmsXlOscXlXXPYLO6t+c9q0fb5H5BYspHJYuIaUYvZjX2MDjweO2fd ZfdYsKnUY9OqTjaPTZ8msXt0vb3C5HFixm8WjydXpjN5LGyYyuzRt2UVo8eZBUfYPT5vkgvg juKySUnNySxLLdK3S+DKOPHiFmPBBJGKGddWMjcwfuXvYuTkkBAwkbj/5it7FyMXh5DAbkaJ 2Q172SESkhKzPp9kgrCFJe63HGGFKPrIKPFsyn5GkASbgLrEiS3LwGwRARaJld+/s4AUMQts Y5a4cXAeG0hCWMBD4vW2C8wgNouAqsTux6/B4rwCNhK7Hr+E2iAvcXvNSRaIuKDEyZlPwGxm oHjz1tnMExj5ZiFJzUKSWsDItIpRMrWgODc9t9iwwDAvtVyvODG3uDQvXS85P3cTIzgetDR3 MG5f9UHvECMTB+MhRgkOZiUR3tPbF6QL8aYkVlalFuXHF5XmpBYfYpTmYFES5xV/0ZsiJJCe WJKanZpakFoEk2Xi4JRqYIp84rJKml3///dZd7P2XI6fObFr7b6U6R+fZBTPOz9tnadfqc5K hdfxvDMrel+7LJbh9rJbxKF7ov/7hg0n0jcdPBgZ1VcVoNL8zdmuuvWdZmQjmxeLd+y3o3qa /AuKrXSVP+85f/neh0lHBBav2zN5ZqV+ge5czTbTLTmT13Hr2oneLn/zZzk399WTZdYJa0pj 9su7Xq1ZM3vx8Ud7PqfOTuFzf5Pwc/nRlLtBsocvnOVPucQw43zA1e0T+pZ86yublSGsUiBT zXM9g3vNQwEVtYdTp5t/9ZjybsO0Yn19FovaNxPdPnrKPQsRyzbq4dzO+HFNeeiP7blnfv54 +XMpc2Za/+cohpKDP9gj92kpsRRnJBpqMRcVJwIAQPTDjPYCAAA= X-CMS-MailID: 20250205004741epcas2p3081bc2c97b7c1c27a9797cd498c4bc64 X-Msg-Generator: CA X-Sendblock-Type: AUTO_CONFIDENTIAL CMS-TYPE: 102P DLP-Filter: Pass X-CFilter-Loop: Reflected X-CMS-RootMailID: 20250205004741epcas2p3081bc2c97b7c1c27a9797cd498c4bc64 References: X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 3AC37180014 X-Stat-Signature: 4sh4yz13qfyorgxdyzwgb8hn348poys5 X-Rspam-User: X-HE-Tag: 1738716465-300319 X-HE-Meta: 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 6Kl+n0sB 8ZrYGeqmUgJ4xqJdSsJpcCIY5pV+GaQ70mzzWF7DxMFU1yd0DI3SpoiCxdv8Jo/IXQLOjMNFEtVImwA8pzC9Z0kyz5gMSfy8F3fBkhMgOFk8OwONurcCDlNuOZGhsgj5vzbRbiloV5EK1GNAZsZuQfbFc6a2zKKed4P99jK+cCDpc3ghWZ0eqiQA+Y0xhDPwsDO73VfLIGg62iJEtlBPwP1ekWg== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: If a slab object is corrupted or an error occurs in its internal value, continuing after restoration may cause other side effects. At this point, it is difficult to debug because the problem occurred in the past. It is better to use WARN() instead of pr_err to catch errors at the point of issue because WARN() could trigger panic for system debugging when panic_on_warn is enabled. WARN() should be called prior to fixing the value because when a panic is triggered by WARN(), it allows us to check corrupted data. Changes in v2: - Replace direct calling with BUG_ON with the use of WARN in slab_fix. Signed-off-by: Hyesoo Yu --- mm/slub.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/mm/slub.c b/mm/slub.c index 1f50129dcfb3..ea956cb4b8be 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -1043,7 +1043,7 @@ static void slab_fix(struct kmem_cache *s, char *fmt, ...) va_start(args, fmt); vaf.fmt = fmt; vaf.va = &args; - pr_err("FIX %s: %pV\n", s->name, &vaf); + WARN(1, "FIX %s: %pV\n", s->name, &vaf); va_end(args); } @@ -1106,8 +1106,8 @@ static bool freelist_corrupted(struct kmem_cache *s, struct slab *slab, if ((s->flags & SLAB_CONSISTENCY_CHECKS) && !check_valid_pointer(s, slab, nextfree) && freelist) { object_err(s, slab, *freelist, "Freechain corrupt"); - *freelist = NULL; slab_fix(s, "Isolate corrupted freechain"); + *freelist = NULL; return true; } @@ -1445,9 +1445,9 @@ static int on_freelist(struct kmem_cache *s, struct slab *slab, void *search) set_freepointer(s, object, NULL); } else { slab_err(s, slab, "Freepointer corrupt"); + slab_fix(s, "Freelist cleared"); slab->freelist = NULL; slab->inuse = slab->objects; - slab_fix(s, "Freelist cleared"); return 0; } break; @@ -1464,14 +1464,14 @@ static int on_freelist(struct kmem_cache *s, struct slab *slab, void *search) if (slab->objects != max_objects) { slab_err(s, slab, "Wrong number of objects. Found %d but should be %d", slab->objects, max_objects); - slab->objects = max_objects; slab_fix(s, "Number of objects adjusted"); + slab->objects = max_objects; } if (slab->inuse != slab->objects - nr) { slab_err(s, slab, "Wrong object count. Counter is %d but counted were %d", slab->inuse, slab->objects - nr); - slab->inuse = slab->objects - nr; slab_fix(s, "Object count adjusted"); + slab->inuse = slab->objects - nr; } return search == NULL; }