From patchwork Tue Jun 17 21:43:36 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kamal Mostafa X-Patchwork-Id: 4371211 Return-Path: X-Original-To: patchwork-linux-parisc@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id D6B1B9F1C4 for ; Tue, 17 Jun 2014 22:07:40 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id EB2D5202AE for ; Tue, 17 Jun 2014 22:07:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 05FCF201B9 for ; Tue, 17 Jun 2014 22:07:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966979AbaFQVwF (ORCPT ); Tue, 17 Jun 2014 17:52:05 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:54729 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S966973AbaFQVwD (ORCPT ); Tue, 17 Jun 2014 17:52:03 -0400 Received: from c-67-160-228-185.hsd1.ca.comcast.net ([67.160.228.185] helo=fourier) by youngberry.canonical.com with esmtpsa (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1Wx1C6-0000Hq-8A; Tue, 17 Jun 2014 21:45:30 +0000 Received: from kamal by fourier with local (Exim 4.82) (envelope-from ) id 1Wx1C4-0003m6-Ct; Tue, 17 Jun 2014 14:45:28 -0700 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: James Hogan , Helge Deller , "James E.J. Bottomley" , linux-parisc@vger.kernel.org, linux-metag@vger.kernel.org, John David Anglin , Kamal Mostafa Subject: [PATCH 3.13 122/212] metag: Reduce maximum stack size to 256MB Date: Tue, 17 Jun 2014 14:43:36 -0700 Message-Id: <1403041506-13646-123-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1403041506-13646-1-git-send-email-kamal@canonical.com> References: <1403041506-13646-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.13 Sender: linux-parisc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-parisc@vger.kernel.org X-Spam-Status: No, score=-7.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP 3.13.11.4 -stable review patch. If anyone has any objections, please let me know. ------------------ From: James Hogan commit d71f290b4e98a39f49f2595a13be3b4d5ce8e1f1 upstream. Specify the maximum stack size for arches where the stack grows upward (parisc and metag) in asm/processor.h rather than hard coding in fs/exec.c so that metag can specify a smaller value of 256MB rather than 1GB. This fixes a BUG on metag if the RLIMIT_STACK hard limit is increased beyond a safe value by root. E.g. when starting a process after running "ulimit -H -s unlimited" it will then attempt to use a stack size of the maximum 1GB which is far too big for metag's limited user virtual address space (stack_top is usually 0x3ffff000): BUG: failure at fs/exec.c:589/shift_arg_pages()! Signed-off-by: James Hogan Cc: Helge Deller Cc: "James E.J. Bottomley" Cc: linux-parisc@vger.kernel.org Cc: linux-metag@vger.kernel.org Cc: John David Anglin Signed-off-by: Kamal Mostafa --- arch/metag/include/asm/processor.h | 2 ++ arch/parisc/include/asm/processor.h | 2 ++ fs/exec.c | 6 +++--- 3 files changed, 7 insertions(+), 3 deletions(-) diff --git a/arch/metag/include/asm/processor.h b/arch/metag/include/asm/processor.h index f16477d..3be8581 100644 --- a/arch/metag/include/asm/processor.h +++ b/arch/metag/include/asm/processor.h @@ -22,6 +22,8 @@ /* Add an extra page of padding at the top of the stack for the guard page. */ #define STACK_TOP (TASK_SIZE - PAGE_SIZE) #define STACK_TOP_MAX STACK_TOP +/* Maximum virtual space for stack */ +#define STACK_SIZE_MAX (1 << 28) /* 256 MB */ /* This decides where the kernel will search for a free chunk of vm * space during mmap's. diff --git a/arch/parisc/include/asm/processor.h b/arch/parisc/include/asm/processor.h index cc2290a..c6ee865 100644 --- a/arch/parisc/include/asm/processor.h +++ b/arch/parisc/include/asm/processor.h @@ -53,6 +53,8 @@ #define STACK_TOP TASK_SIZE #define STACK_TOP_MAX DEFAULT_TASK_SIZE +#define STACK_SIZE_MAX (1 << 30) /* 1 GB */ + #endif #ifndef __ASSEMBLY__ diff --git a/fs/exec.c b/fs/exec.c index 7ea097f..5743b8f 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -655,10 +655,10 @@ int setup_arg_pages(struct linux_binprm *bprm, unsigned long rlim_stack; #ifdef CONFIG_STACK_GROWSUP - /* Limit stack size to 1GB */ + /* Limit stack size */ stack_base = rlimit_max(RLIMIT_STACK); - if (stack_base > (1 << 30)) - stack_base = 1 << 30; + if (stack_base > STACK_SIZE_MAX) + stack_base = STACK_SIZE_MAX; /* Make sure we didn't let the argument array grow too large. */ if (vma->vm_end - vma->vm_start > stack_base)