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=-14.2 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 F3BF9C43381 for ; Sat, 23 Feb 2019 21:18:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BDEFC20651 for ; Sat, 23 Feb 2019 21:18:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1550956720; bh=1KjYLO2d2v1dzF55nKQyZk899jcu1N+0V/IWtEDlhEI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=nCSLxDf64NRzW7Vk78LbR9FoqN6m8GDPIiOXc7c4mPE8/EpK/aJb1lgKBWjIjL+pm KQ5OsUos9vCCQphra9bM1OSkiKsespOhcbW46b4svYElI5v8CvkwC9wbCggBtrQV/t OdvX9n4X5mpqlZzH1D+bInTyOSQg+OsFRUPQhdk0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729619AbfBWVSj (ORCPT ); Sat, 23 Feb 2019 16:18:39 -0500 Received: from mail.kernel.org ([198.145.29.99]:45390 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729576AbfBWVJk (ORCPT ); Sat, 23 Feb 2019 16:09:40 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id D418E20855; Sat, 23 Feb 2019 21:09:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1550956179; bh=1KjYLO2d2v1dzF55nKQyZk899jcu1N+0V/IWtEDlhEI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=tARekGYiGE+gXr2UyVZJnIMxdxWgidvDasu6FCUxz50oaz9/hAzzhRhFobqBJukGs eOvI5sQ10m21pBRECCTSPjXMZOFaKTZ18ppJ2kRoGceyo2JuxqnRLdv4qpdjqUOhUq lQUMbhjL9QaNF+fOOuz4Tt7wDw8PkEHgHxBp4+sE= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Qian Cai , Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H. Peter Anvin" , Andrey Ryabinin , Alexander Potapenko , Dmitry Vyukov , Andrew Morton , Linus Torvalds , Sasha Levin Subject: [PATCH AUTOSEL 4.14 39/45] x86_64: increase stack size for KASAN_EXTRA Date: Sat, 23 Feb 2019 16:08:29 -0500 Message-Id: <20190223210835.201708-39-sashal@kernel.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20190223210835.201708-1-sashal@kernel.org> References: <20190223210835.201708-1-sashal@kernel.org> MIME-Version: 1.0 X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Qian Cai [ Upstream commit a8e911d13540487942d53137c156bd7707f66e5d ] If the kernel is configured with KASAN_EXTRA, the stack size is increasted significantly because this option sets "-fstack-reuse" to "none" in GCC [1]. As a result, it triggers stack overrun quite often with 32k stack size compiled using GCC 8. For example, this reproducer https://github.com/linux-test-project/ltp/blob/master/testcases/kernel/syscalls/madvise/madvise06.c triggers a "corrupted stack end detected inside scheduler" very reliably with CONFIG_SCHED_STACK_END_CHECK enabled. There are just too many functions that could have a large stack with KASAN_EXTRA due to large local variables that have been called over and over again without being able to reuse the stacks. Some noticiable ones are size 7648 shrink_page_list 3584 xfs_rmap_convert 3312 migrate_page_move_mapping 3312 dev_ethtool 3200 migrate_misplaced_transhuge_page 3168 copy_process There are other 49 functions are over 2k in size while compiling kernel with "-Wframe-larger-than=" even with a related minimal config on this machine. Hence, it is too much work to change Makefiles for each object to compile without "-fsanitize-address-use-after-scope" individually. [1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81715#c23 Although there is a patch in GCC 9 to help the situation, GCC 9 probably won't be released in a few months and then it probably take another 6-month to 1-year for all major distros to include it as a default. Hence, the stack usage with KASAN_EXTRA can be revisited again in 2020 when GCC 9 is everywhere. Until then, this patch will help users avoid stack overrun. This has already been fixed for arm64 for the same reason via 6e8830674ea ("arm64: kasan: Increase stack size for KASAN_EXTRA"). Link: http://lkml.kernel.org/r/20190109215209.2903-1-cai@lca.pw Signed-off-by: Qian Cai Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Borislav Petkov Cc: "H. Peter Anvin" Cc: Andrey Ryabinin Cc: Alexander Potapenko Cc: Dmitry Vyukov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin --- arch/x86/include/asm/page_64_types.h | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/x86/include/asm/page_64_types.h b/arch/x86/include/asm/page_64_types.h index 74d531f6d5180..50c8baaca4b06 100644 --- a/arch/x86/include/asm/page_64_types.h +++ b/arch/x86/include/asm/page_64_types.h @@ -7,7 +7,11 @@ #endif #ifdef CONFIG_KASAN +#ifdef CONFIG_KASAN_EXTRA +#define KASAN_STACK_ORDER 2 +#else #define KASAN_STACK_ORDER 1 +#endif #else #define KASAN_STACK_ORDER 0 #endif -- 2.19.1