From patchwork Mon Feb 8 00:28:43 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Neuling X-Patchwork-Id: 44750 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from bilbo.ozlabs.org (localhost [127.0.0.1]) by ozlabs.org (Postfix) with ESMTP id CB1D5B7F48 for ; Mon, 8 Feb 2010 11:28:52 +1100 (EST) Received: by ozlabs.org (Postfix) id 6439DB7CFA; Mon, 8 Feb 2010 11:28:44 +1100 (EST) Delivered-To: linuxppc-dev@ozlabs.org Received: from localhost.localdomain (localhost [127.0.0.1]) by ozlabs.org (Postfix) with ESMTP id 25C69B7CBB; Mon, 8 Feb 2010 11:28:44 +1100 (EST) Received: by localhost.localdomain (Postfix, from userid 1000) id B156912023; Mon, 8 Feb 2010 11:28:43 +1100 (EST) Received: from neuling.org (localhost [127.0.0.1]) by localhost.localdomain (Postfix) with ESMTP id A9A592200D; Mon, 8 Feb 2010 11:28:43 +1100 (EST) From: Michael Neuling To: Andrew Morton , Linus Torvalds Subject: [PATCH] Restrict stack space reservation to rlimit In-reply-to: <18033.1265587672@neuling.org> References: <3984.1265416993@neuling.org> <20100206042038.GB32246@kryten> <10125.1265451732@neuling.org> <18033.1265587672@neuling.org> Comments: In-reply-to Michael Neuling message dated "Mon, 08 Feb 2010 11:07:52 +1100." X-Mailer: MH-E 8.2; nmh 1.3; GNU Emacs 23.1.1 Date: Mon, 08 Feb 2010 11:28:43 +1100 Message-ID: <19732.1265588923@neuling.org> Cc: linux-kernel@vger.kernel.org, aeb@cwi.nl, James Morris , miltonm@bga.com, Oleg Nesterov , linuxppc-dev@ozlabs.org, Paul Mackerras , Ollie Wild , WANG Cong , linux-fsdevel@vger.kernel.org, Serge Hallyn , Ingo Molnar , stable@kernel.org, Anton Blanchard , Alexander Viro X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.13 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org When reserving stack space for a new process, make sure we're not attempting to allocate more than rlimit allows. Also, reserve the same stack size independent of page size. This fixes a bug cause by b6a2fea39318e43fee84fa7b0b90d68bed92d2ba "mm: variable length argument support" and unmasked by fc63cf237078c86214abcb2ee9926d8ad289da9b "exec: setup_arg_pages() fails to return errors". Signed-off-by: Michael Neuling Cc: Anton Blanchard Cc: stable@kernel.org --- Update commit message to include patch name and SHA1 of related patches. fs/exec.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) Index: clone1/fs/exec.c =================================================================== --- clone1.orig/fs/exec.c +++ clone1/fs/exec.c @@ -554,7 +554,7 @@ static int shift_arg_pages(struct vm_are return 0; } -#define EXTRA_STACK_VM_PAGES 20 /* random */ +#define EXTRA_STACK_VM_SIZE 81920UL /* randomly 20 4K pages */ /* * Finalizes the stack vm_area_struct. The flags and permissions are updated, @@ -627,10 +627,13 @@ int setup_arg_pages(struct linux_binprm goto out_unlock; } + stack_base = min(EXTRA_STACK_VM_SIZE, + current->signal->rlim[RLIMIT_STACK].rlim_cur) - + PAGE_SIZE; #ifdef CONFIG_STACK_GROWSUP - stack_base = vma->vm_end + EXTRA_STACK_VM_PAGES * PAGE_SIZE; + stack_base = vma->vm_end + stack_base; #else - stack_base = vma->vm_start - EXTRA_STACK_VM_PAGES * PAGE_SIZE; + stack_base = vma->vm_start - stack_base; #endif ret = expand_stack(vma, stack_base); if (ret)