From patchwork Sun Sep 18 09:21:46 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chao Yu X-Patchwork-Id: 12979375 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 C1844C32771 for ; Sun, 18 Sep 2022 09:22:13 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id E6A2F940008; Sun, 18 Sep 2022 05:22:12 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id E19A8940007; Sun, 18 Sep 2022 05:22:12 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id CE172940008; Sun, 18 Sep 2022 05:22:12 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id C11B9940007 for ; Sun, 18 Sep 2022 05:22:12 -0400 (EDT) Received: from smtpin19.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 92879160D82 for ; Sun, 18 Sep 2022 09:22:12 +0000 (UTC) X-FDA: 79924664904.19.FCC58B2 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by imf12.hostedemail.com (Postfix) with ESMTP id 42BEE4001A for ; Sun, 18 Sep 2022 09:22:12 +0000 (UTC) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 487D36123D; Sun, 18 Sep 2022 09:22:11 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1B754C433D6; Sun, 18 Sep 2022 09:22:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1663492930; bh=d3t5vaJ7vpph6uaJ6/CLOVhFeXHAy4FKOvb8EhJO0vE=; h=From:To:Cc:Subject:Date:From; b=bZnt1YBTZePDwrE/lyj0niNlKTnwv6m78bMIrck6gMy+9JyZmLqExPfXEZtxbDGub p29TwO1g4NjpruzgtOi8TweChcRH1Wjjc/zqJj8FjEgP8dXOWTIDsc0Fqug9+1VNWP OwYdFmEP+8l6xuUgaZsqd0uPl6NCDMqMyQZsVjPWUV9UnV+euZc93bUAos8QkKMd0T ymz1NbLSq34Zz8jsgmVK4Ijk2+4BHOLYooQpgouLjjGnxa09A0xhHgR3radr6sfZF3 oaJlotGcpAk2Cw0DNKbN5dAxQrR71UZcN3Pi4PoaatLSjBPe2Wd1fccWMABMuR18TN lcXeX6h2x/pUA== From: Chao Yu To: Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , Andrew Morton , Vlastimil Babka , Roman Gushchin , Hyeonggon Yoo <42.hyeyoo@gmail.com>, Hugh Dickins Cc: chao@kernel.org, Chao Yu , Christophe JAILLET , Christoph Lameter , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH] mm/slub: clean up create_unique_id() Date: Sun, 18 Sep 2022 17:21:46 +0800 Message-Id: <20220918092146.4060783-1-chao@kernel.org> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1663492932; 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:references:dkim-signature; bh=PqdhO5k4Z85sIEPaq0G1VZvBqs76/URsmT4HLPPOTOk=; b=mDiYpc7os7r5ma/dkYG44glUI44MkndWUT9388rc8mxJwfd8g5CZ891CfpKYM0b1drFk+R GwyXIqQc0TZ2SiD/GB8dg7YbSsdg0JSSNc8CPCGztMP1efHhBVZp9jLhWEWwn7EVHTLSCF YzZPSw5HWelWMmP+eCtJXN06y9R0MM4= ARC-Authentication-Results: i=1; imf12.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=bZnt1YBT; spf=pass (imf12.hostedemail.com: domain of chao@kernel.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=chao@kernel.org; dmarc=pass (policy=none) header.from=kernel.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1663492932; a=rsa-sha256; cv=none; b=vaHQ0Mt4URpzc6hz07hvhpnaOxutF2l04+kUMaCI9xd9/h6NJ7Epob1JuR0ZCxG7NXlPED isJ+xjYFdJsyc/YHuMNceYEpctdKzmZnNl7I/QWqdQDAZBlBFDsCeIjFmQAYL5qrMg9oNU w/q4JhaeGkRuM0riDw+b8cRqnSOqC0g= X-Rspamd-Queue-Id: 42BEE4001A Authentication-Results: imf12.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=bZnt1YBT; spf=pass (imf12.hostedemail.com: domain of chao@kernel.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=chao@kernel.org; dmarc=pass (policy=none) header.from=kernel.org X-Rspam-User: X-Rspamd-Server: rspam01 X-Stat-Signature: smyag1i9dqqusejjtkkj1t7xxe57oii4 X-HE-Tag: 1663492932-124866 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: From: Chao Yu As Christophe JAILLET suggested: In create_unique_id(), "looks that ID_STR_LENGTH could even be reduced to 32 or 16. The 2nd BUG_ON at the end of the function could certainly be just removed as well or remplaced by a: if (p > name + ID_STR_LENGTH - 1) { kfree(name); return -E; } " According to above suggestion, let's do below cleanups: 1. reduce ID_STR_LENGTH to 32, as the buffer size should be enough; 2. remove BUG_ON() and return error if check condition is true. Link: https://lore.kernel.org/linux-mm/2025305d-16db-abdf-6cd3-1fb93371c2b4@wanadoo.fr/ Suggested-by: Christophe JAILLET Fixes: 81819f0fc828 ("SLUB core") Signed-off-by: Chao Yu Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> --- mm/slub.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/mm/slub.c b/mm/slub.c index 5ba6db62a5ab..a045c1ca8772 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -5883,7 +5883,7 @@ static inline struct kset *cache_kset(struct kmem_cache *s) return slab_kset; } -#define ID_STR_LENGTH 64 +#define ID_STR_LENGTH 32 /* Create a unique string id for a slab cache: * @@ -5919,7 +5919,10 @@ static char *create_unique_id(struct kmem_cache *s) *p++ = '-'; p += sprintf(p, "%07u", s->size); - BUG_ON(p > name + ID_STR_LENGTH - 1); + if (p > name + ID_STR_LENGTH - 1) { + kfree(name); + return ERR_PTR(-EINVAL); + } return name; }