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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C1089C32771 for ; Sun, 18 Sep 2022 09:22:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229673AbiIRJWT (ORCPT ); Sun, 18 Sep 2022 05:22:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49986 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229511AbiIRJWM (ORCPT ); Sun, 18 Sep 2022 05:22:12 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BBEF61EC41 for ; Sun, 18 Sep 2022 02:22:11 -0700 (PDT) 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 551AE61370 for ; 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 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 --- 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; } -- 2.25.1