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=-9.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,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 2A231C10F11 for ; Mon, 22 Apr 2019 20:04:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DDD22204EC for ; Mon, 22 Apr 2019 20:04:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1555963495; bh=0NHLvwfoKQMlaQaxzUsbEC/SYdZ/fTDhC2rT8mW3vRE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=GijJqUvl3TbsOKQaIhcy4piFTHVo6JUA2IuZWUC1ELvYD0GMrIUys3/grt/g65H9s H3OXpOcnwpbAsn4hgjFvb5WhQIRI7A0esDR/ExZWY5EfSXS48ioV9/JeOJwHcqB1LV ngkrgcY0DPY92drTfhDhqfgv/ikD/+J1JvxGPOEI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731529AbfDVUEy (ORCPT ); Mon, 22 Apr 2019 16:04:54 -0400 Received: from mail.kernel.org ([198.145.29.99]:47084 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729719AbfDVTpX (ORCPT ); Mon, 22 Apr 2019 15:45:23 -0400 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 B459E21901; Mon, 22 Apr 2019 19:45:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1555962322; bh=0NHLvwfoKQMlaQaxzUsbEC/SYdZ/fTDhC2rT8mW3vRE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=vUarLLJw8gmFXjQ0ukmIsR9vcv5R+wcpZ5pXk6RmOabN/FFt8fN7zG9ooH7/9NdRC Xzyzguyes5vUNE3HWOlIC4Amyyu+2183V9q91xcgZeA4Zqeydq/+eDJY0R5I75KfxJ E3HGnqktuez+DsGOidDxH8jcV1B3B7gx3v4ftVCI= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Martin Schwidefsky , Sasha Levin , linux-s390@vger.kernel.org Subject: [PATCH AUTOSEL 4.19 02/68] s390: limit brk randomization to 32MB Date: Mon, 22 Apr 2019 15:44:10 -0400 Message-Id: <20190422194516.11634-2-sashal@kernel.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20190422194516.11634-1-sashal@kernel.org> References: <20190422194516.11634-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Martin Schwidefsky [ Upstream commit cd479eccd2e057116d504852814402a1e68ead80 ] For a 64-bit process the randomization of the program break is quite large with 1GB. That is as big as the randomization of the anonymous mapping base, for a test case started with '/lib/ld64.so.1 ' it can happen that the heap is placed after the stack. To avoid this limit the program break randomization to 32MB for 64-bit and keep 8MB for 31-bit. Reported-by: Stefan Liebler Signed-off-by: Martin Schwidefsky Signed-off-by: Sasha Levin (Microsoft) --- arch/s390/include/asm/elf.h | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/arch/s390/include/asm/elf.h b/arch/s390/include/asm/elf.h index 7d22a474a040..f74639a05f0f 100644 --- a/arch/s390/include/asm/elf.h +++ b/arch/s390/include/asm/elf.h @@ -252,11 +252,14 @@ do { \ /* * Cache aliasing on the latest machines calls for a mapping granularity - * of 512KB. For 64-bit processes use a 512KB alignment and a randomization - * of up to 1GB. For 31-bit processes the virtual address space is limited, - * use no alignment and limit the randomization to 8MB. + * of 512KB for the anonymous mapping base. For 64-bit processes use a + * 512KB alignment and a randomization of up to 1GB. For 31-bit processes + * the virtual address space is limited, use no alignment and limit the + * randomization to 8MB. + * For the additional randomization of the program break use 32MB for + * 64-bit and 8MB for 31-bit. */ -#define BRK_RND_MASK (is_compat_task() ? 0x7ffUL : 0x3ffffUL) +#define BRK_RND_MASK (is_compat_task() ? 0x7ffUL : 0x1fffUL) #define MMAP_RND_MASK (is_compat_task() ? 0x7ffUL : 0x3ff80UL) #define MMAP_ALIGN_MASK (is_compat_task() ? 0 : 0x7fUL) #define STACK_RND_MASK MMAP_RND_MASK -- 2.19.1