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 X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 00210C2BB1D for ; Fri, 17 Apr 2020 07:17:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CDC072083E for ; Fri, 17 Apr 2020 07:17:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729016AbgDQHRu (ORCPT ); Fri, 17 Apr 2020 03:17:50 -0400 Received: from m176115.mail.qiye.163.com ([59.111.176.115]:38929 "EHLO m176115.mail.qiye.163.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728808AbgDQHRt (ORCPT ); Fri, 17 Apr 2020 03:17:49 -0400 X-Greylist: delayed 459 seconds by postgrey-1.27 at vger.kernel.org; Fri, 17 Apr 2020 03:17:48 EDT Received: from ubuntu.localdomain (unknown [157.0.31.122]) by m176115.mail.qiye.163.com (Hmail) with ESMTPA id 37C2C665296; Fri, 17 Apr 2020 15:10:06 +0800 (CST) From: Bernard Zhao To: Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org Cc: kernel@vivo.com, Bernard Zhao Subject: [PATCH] kmalloc_index optimization(add kmalloc max size check) Date: Fri, 17 Apr 2020 00:09:35 -0700 Message-Id: <1587107376-111722-1-git-send-email-bernard@vivo.com> X-Mailer: git-send-email 2.7.4 X-HM-Spam-Status: e1kfGhgUHx5ZQUtXWQgYFAkeWUFZT1VJS09CQkJCSUhMS01LTllXWShZQU hPN1dZLVlBSVdZCQ4XHghZQVk1NCk2OjckKS43PlkG X-HM-Sender-Digest: e1kMHhlZQR0aFwgeV1kSHx4VD1lBWUc6Myo6EQw6ATg4LA4jAxg#CQJD LTcKCz5VSlVKTkNMSktMT0tNT09CVTMWGhIXVRkeCRUaCR87DRINFFUYFBZFWVdZEgtZQVlKTkxV S1VISlVKSUlZV1kIAVlBSUtOQzcG X-HM-Tid: 0a7186f922229373kuws37c2c665296 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org kmalloc size should never exceed KMALLOC_MAX_SIZE. kmalloc_index realise if size is exceed KMALLOC_MAX_SIZE, e.g 64M, kmalloc_index just return index 26, but never check with OS`s max kmalloc config KMALLOC_MAX_SIZE. This index`s kmalloc caches maybe not create in function create_kmalloc_caches. We can throw an warninginfo in kmalloc at the beginning, instead of being guaranteed by the buddy alloc behind. Signed-off-by: Bernard Zhao --- include/linux/slab.h | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/include/linux/slab.h b/include/linux/slab.h index 6d45488..59b60d2 100644 --- a/include/linux/slab.h +++ b/include/linux/slab.h @@ -351,6 +351,10 @@ static __always_inline unsigned int kmalloc_index(size_t size) if (!size) return 0; + /* size should never exceed KMALLOC_MAX_SIZE. */ + if (size > KMALLOC_MAX_SIZE) + WARN(1, "size exceed max kmalloc size!\n"); + if (size <= KMALLOC_MIN_SIZE) return KMALLOC_SHIFT_LOW; -- 2.7.4