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]) by smtp.lore.kernel.org (Postfix) with ESMTP id 95E6EC83F25 for ; Wed, 23 Jul 2025 07:46:46 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 13FD96B008A; Wed, 23 Jul 2025 03:46:46 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 0F04B6B0093; Wed, 23 Jul 2025 03:46:46 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 005FA6B0095; Wed, 23 Jul 2025 03:46:45 -0400 (EDT) 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 E4BA16B008A for ; Wed, 23 Jul 2025 03:46:45 -0400 (EDT) Received: from smtpin25.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay05.hostedemail.com (Postfix) with ESMTP id 4B10559C91 for ; Wed, 23 Jul 2025 07:46:45 +0000 (UTC) X-FDA: 83694747570.25.7E7BD47 Received: from m16.mail.163.com (m16.mail.163.com [220.197.31.3]) by imf19.hostedemail.com (Postfix) with ESMTP id 86EBE1A0006 for ; Wed, 23 Jul 2025 07:46:40 +0000 (UTC) Authentication-Results: imf19.hostedemail.com; dkim=pass header.d=163.com header.s=s110527 header.b=VIu3RiMc; spf=pass (imf19.hostedemail.com: domain of liuqiye2025@163.com designates 220.197.31.3 as permitted sender) smtp.mailfrom=liuqiye2025@163.com; dmarc=pass (policy=none) header.from=163.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1753256803; a=rsa-sha256; cv=none; b=vQN8RURzoCChNZqc5dXEZ4F7Muy4sa18y736qcckZn/zJ01W6leQIOUOooqNql40ZLXR5F xPaAmY28ZvI7tTKnWweEClImJa/e+9JYVOQbhqJ/e3kRpvnbBAvn3pwrZK5MoxcpGwwD0U 2cdu7Ew851WKaDUakDaOqm9qbHCDfWo= ARC-Authentication-Results: i=1; imf19.hostedemail.com; dkim=pass header.d=163.com header.s=s110527 header.b=VIu3RiMc; spf=pass (imf19.hostedemail.com: domain of liuqiye2025@163.com designates 220.197.31.3 as permitted sender) smtp.mailfrom=liuqiye2025@163.com; dmarc=pass (policy=none) header.from=163.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1753256803; 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:in-reply-to:references:references:dkim-signature; bh=QdwtM+ZTobn78aFin1VxfehR87TJtajIWuTIlJuGaW4=; b=IwY1EVrVv9hccQdcp5EiYajKo83uRAnvwYKDg6msWr5D9YMl3L3YPWAErYuaaLAkgyKsz+ enUcBxwE1XbOVOVaXkJW4siULtfPnnFi71HqTZISabSQM4Rw0iX5J+WYUlyuX0UDDHMXxp tacVNTDXrl06hgJeqT7kv/ky8//2o8I= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=163.com; s=s110527; h=Message-ID:Date:MIME-Version:Subject:To:From: Content-Type; bh=QdwtM+ZTobn78aFin1VxfehR87TJtajIWuTIlJuGaW4=; b=VIu3RiMc1TE02syEQwNuBjti6uiptRARgYNN0+LAri/La9G1cMGP9RPykKBftQ z9ILruiFz2VDheTiOQ4mf6oFMMwLNPKWMxMlsyi+HhRQio2xiJxYK0mndl/XLL+D w0ejlh1YcG4mU2C1m/EEfo0PdjrGVsoxhX6krUT+MDnMs= Received: from [192.168.22.151] (unknown []) by gzga-smtp-mtada-g1-3 (Coremail) with SMTP id _____wDHPKw3k4Bo1_HrGg--.1050S2; Wed, 23 Jul 2025 15:46:04 +0800 (CST) Message-ID: Date: Wed, 23 Jul 2025 15:45:58 +0800 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] mm: add stack trace when bad rss-counter state is detected To: Kees Cook Cc: Ingo Molnar , Peter Zijlstra , Juri Lelli , Vincent Guittot , Andrew Morton , David Hildenbrand , Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Valentin Schneider , linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <20250723072350.1742071-1-liuqiye2025@163.com> <202507230031.52B5C2B53@keescook> Content-Language: en-US From: Xuanye Liu In-Reply-To: <202507230031.52B5C2B53@keescook> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-CM-TRANSID:_____wDHPKw3k4Bo1_HrGg--.1050S2 X-Coremail-Antispam: 1Uf129KBjvJXoW7Ww48uw4kJr48CryDXr4xJFb_yoW8GF45pF n3KF1DJFWkX342gasIva1qyry5tw4qqryag34kA3yfKr9xtF1FqF45Kr4UKF1qkryxK3WS 9F4jgrnrAa90vFDanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDUYxBIdaVFxhVjvjDU0xZFpf9x07jr2-nUUUUU= X-Originating-IP: [223.70.160.239] X-CM-SenderInfo: 5olx1xd1hsijqv6rljoofrz/1tbiMAGTUGiAiBfEtwABs3 X-Rspam-User: X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 86EBE1A0006 X-Stat-Signature: jq3pshbscubwnn19xoae3y3mqk3awwf6 X-HE-Tag: 1753256800-879592 X-HE-Meta: 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 7mqQ8yXY 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 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: 在 2025/7/23 15:31, Kees Cook 写道: > On Wed, Jul 23, 2025 at 03:23:49PM +0800, Xuanye Liu wrote: >> The check_mm() function verifies the correctness of rss counters in >> struct mm_struct. Currently, it only prints an alert when a bad >> rss-counter state is detected, but lacks sufficient context for >> debugging. >> >> This patch adds a dump_stack() call to provide a stack trace when >> the rss-counter state is invalid. This helps developers identify >> where the corrupted mm_struct is being checked and trace the >> underlying cause of the inconsistency. > Why not just convert the pr_alert to a WARN? Good idea! I'll gather more feedback from others and then update to v2. > > -Kees > >> Signed-off-by: Xuanye Liu >> --- >> kernel/fork.c | 4 +++- >> 1 file changed, 3 insertions(+), 1 deletion(-) >> >> diff --git a/kernel/fork.c b/kernel/fork.c >> index cfe2f1df5f27..d38f1c5270ea 100644 >> --- a/kernel/fork.c >> +++ b/kernel/fork.c >> @@ -584,9 +584,11 @@ static void check_mm(struct mm_struct *mm) >> for (i = 0; i < NR_MM_COUNTERS; i++) { >> long x = percpu_counter_sum(&mm->rss_stat[i]); >> >> - if (unlikely(x)) >> + if (unlikely(x)) { >> pr_alert("BUG: Bad rss-counter state mm:%p type:%s val:%ld\n", >> mm, resident_page_types[i], x); >> + dump_stack(); >> + } >> } >> >> if (mm_pgtables_bytes(mm)) >> -- >> 2.43.0 >> -- Thanks, Xuanye