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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 1F84AC5CFCF for ; Thu, 13 Aug 2026 16:18:02 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 3B9DB6B0539; Thu, 13 Aug 2026 12:18:01 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 390DA6B0541; Thu, 13 Aug 2026 12:18:01 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 27FF06B0543; Thu, 13 Aug 2026 12:18:01 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id 085FC6B0539 for ; Thu, 13 Aug 2026 12:18:01 -0400 (EDT) Received: from smtpin12.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay10.hostedemail.com (Postfix) with ESMTP id 9116BC01EF for ; Thu, 13 Aug 2026 16:18:00 +0000 (UTC) X-FDA: 85096752720.12.EA479FC Received: from cstnet.cn (smtp21.cstnet.cn [159.226.251.21]) by imf26.hostedemail.com (Postfix) with ESMTP id B4574140008 for ; Thu, 13 Aug 2026 16:17:57 +0000 (UTC) Authentication-Results: imf26.hostedemail.com; spf=pass (imf26.hostedemail.com: domain of pengpeng@iscas.ac.cn designates 159.226.251.21 as permitted sender) smtp.mailfrom=pengpeng@iscas.ac.cn ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1786637878; 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-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Icyie6iqKeeeM/yHnGjppFziBJm96uBgX62zqkHxlaY=; b=R7Zzj4tzC8kkgu1AsBBRq098ezZHHMqv1ZGtCqthk3uoLJlBpkvC9AzgvYqUDZxfF+JL6V iDhFAMcGpNd7Zyqbr9UybGbE8NuxnFNOfMH2lWbhor93HsOLchXtA3zA2r6j8WqWB7rJNq doQ2VTg73x+ssIFBC7zC6776FCm7DcE= ARC-Authentication-Results: i=1; imf26.hostedemail.com; dkim=none; dmarc=none; spf=pass (imf26.hostedemail.com: domain of pengpeng@iscas.ac.cn designates 159.226.251.21 as permitted sender) smtp.mailfrom=pengpeng@iscas.ac.cn ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1786637878; b=o5BqyTTbj5Mc7xBlCWF+vKZyBgPi5PQg/xfVs8scgD/w3CjCh328zXkiohOUqZ5KWmlyh0 gXpAwLKvBAdikL4KgcNveoU7mLoNGeypQ6PdJ0BQvDcdv0X5kVCiDiQHnxLXrc/P9E7eFq S8Mgq9n+tJ4+8zXeDVveLMfkiqs6nYc= Received: from localhost.localdomain (unknown [111.196.241.250]) by APP-01 (Coremail) with SMTP id qwCowAAHofQt7n1qad57BQ--.20463S2; Fri, 14 Aug 2026 00:17:50 +0800 (CST) From: Pengpeng Hou To: Vlastimil Babka , Andrew Morton , linux-mm@kvack.org Cc: Harry Yoo , Hao Li , Christoph Lameter , David Rientjes , Roman Gushchin , David Hildenbrand , Lorenzo Stoakes , "Liam R. Howlett" , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Jonathan Corbet , Shuah Khan , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, Pengpeng Hou Subject: [PATCH v2 4/4] Documentation/mm: describe SLUB previous lifetime tracking Date: Fri, 14 Aug 2026 00:17:48 +0800 Message-ID: <20260813161748.76447-1-pengpeng@iscas.ac.cn> X-Mailer: git-send-email 2.50.1 In-Reply-To: <20260813160825.73031-1-pengpeng@iscas.ac.cn> References: <20260813160825.73031-1-pengpeng@iscas.ac.cn> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CM-TRANSID:qwCowAAHofQt7n1qad57BQ--.20463S2 X-Coremail-Antispam: 1UD129KBjvJXoW7WryfuFW5tr1ktw4xuFy8Krg_yoW8ur15pa 9rGw1xta4UGrn2kr95Ar1rKF1Sqan5uay3CF4UKr48uwn8JwnFyF4Fkrn8ZFn5AFWkCaya vrWvv3Wayw1qyrJanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUU9S14x267AKxVW5JVWrJwAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2ocxC64kIII0Yj41l84x0c7CEw4AK67xGY2AK02 1l84ACjcxK6xIIjxv20xvE14v26r4j6ryUM28EF7xvwVC0I7IYx2IY6xkF7I0E14v26r4U JVWxJr1l84ACjcxK6I8E87Iv67AKxVW8JVWxJwA2z4x0Y4vEx4A2jsIEc7CjxVAFwI0_Gr 1j6F4UJwAS0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0VAKzVAqx4xG6I80ewAv 7VC0I7IYx2IY67AKxVWUAVWUtwAv7VC2z280aVAFwI0_Jr0_Gr1lOx8S6xCaFVCjc4AY6r 1j6r4UM4x0Y48IcxkI7VAKI48JM4x0x7Aq67IIx4CEVc8vx2IErcIFxwACI402YVCY1x02 628vn2kIc2xKxwCY1x0262kKe7AKxVW8ZVWrXwCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4 IE7xkEbVWUJVW8JwC20s026c02F40E14v26r1j6r18MI8I3I0E7480Y4vE14v26r106r1r MI8E67AF67kF1VAFwI0_GFv_WrylIxkGc2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUCV W8JwCI42IY6xIIjxv20xvEc7CjxVAFwI0_Gr1j6F4UJwCI42IY6xAIw20EY4v20xvaj40_ Jr0_JF4lIxAIcVC2z280aVAFwI0_Jr0_Gr1lIxAIcVC2z280aVCY1x0267AKxVW8Jr0_Cr 1UYxBIdaVFxhVjvjDU0xZFpf9x0pRLIDwUUUUU= X-Originating-IP: [111.196.241.250] X-CM-SenderInfo: pshqw1xhqjqxpvfd2hldfou0/ X-Rspamd-Queue-Id: B4574140008 X-Stat-Signature: fu7h3yaws93z9xn3a3tpp1oy1sjtidyz X-Rspam-User: X-Rspamd-Server: rspam11 X-HE-Tag: 1786637877-338028 X-HE-Meta: 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 Ugi3hCQ6 WMe0Cd8q96mKtEOii4qKUdCgu+7ffYITuHvtFERC60bNbRQRxraChR23ebqfU6rOGKEmIc7lcCCcnFiIshmqRxjxfjZN9fVvdgGCl/xSr5NWv7S9tfEMYH9RU3s60zAGokqeYLytNB14n2UHGKXtawvc5U9IvSPLKpXNg Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: Document that SLAB_STORE_USER now retains one previous completed allocation/free pair, show the additional report section, and state that address history is diagnostic evidence rather than semantic ownership attribution. Assisted-by: Codex:gpt-5 Signed-off-by: Pengpeng Hou --- Documentation/admin-guide/mm/slab.rst | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/Documentation/admin-guide/mm/slab.rst b/Documentation/admin-guide/mm/slab.rst index 14429ab90611..5f60904b1e0b 100644 --- a/Documentation/admin-guide/mm/slab.rst +++ b/Documentation/admin-guide/mm/slab.rst @@ -49,7 +49,8 @@ Possible debug options are:: Sorry SLAB legacy issues) Z Red zoning P Poisoning (object and padding) - U User tracking (free and alloc) + U User tracking (free and alloc, plus one previous + completed object lifetime) T Trace (please only use on single slabs) A Enable failslab filter mark for the cache O Switch debugging off for caches that would have @@ -245,10 +246,20 @@ into the syslog: cpu> pid= INFO: Freed in age= cpu= pid= + INFO: Previous object lifetime: + INFO: Allocated in age= cpu= pid= + INFO: Freed in age= cpu= + pid= (Object allocation / free information is only available if SLAB_STORE_USER is set for the slab. slab_debug sets that option) + If an object with a completed allocation/free pair is reused, user tracking + also retains that pair as the previous object lifetime. This address history + can help diagnose stale references after reuse, but it does not establish + semantic ownership or identify a use-after-free root cause by itself. + 2. The object contents if an object was involved. Various types of lines can follow the BUG SLUB line: -- 2.50.1 (Apple Git-155)