From patchwork Wed May 14 12:52:46 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: James Hogan X-Patchwork-Id: 4174521 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 EEE129F387 for ; Wed, 14 May 2014 12:53:15 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 005F720340 for ; Wed, 14 May 2014 12:53:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0908920364 for ; Wed, 14 May 2014 12:53:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932072AbaENMxI (ORCPT ); Wed, 14 May 2014 08:53:08 -0400 Received: from mailapp01.imgtec.com ([195.59.15.196]:34827 "EHLO mailapp01.imgtec.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755553AbaENMxB (ORCPT ); Wed, 14 May 2014 08:53:01 -0400 Received: from KLMAIL01.kl.imgtec.org (unknown [192.168.5.35]) by Websense Email Security Gateway with ESMTPS id CE7E9A78DDCB2; Wed, 14 May 2014 13:52:55 +0100 (IST) Received: from KLMAIL02.kl.imgtec.org (192.168.5.97) by KLMAIL01.kl.imgtec.org (192.168.5.35) with Microsoft SMTP Server (TLS) id 14.3.181.6; Wed, 14 May 2014 13:52:58 +0100 Received: from LEMAIL01.le.imgtec.org (192.168.152.62) by klmail02.kl.imgtec.org (192.168.5.97) with Microsoft SMTP Server (TLS) id 14.3.181.6; Wed, 14 May 2014 13:52:58 +0100 Received: from jhogan-linux.le.imgtec.org (192.168.154.101) by LEMAIL01.le.imgtec.org (192.168.152.62) with Microsoft SMTP Server (TLS) id 14.3.174.1; Wed, 14 May 2014 13:52:57 +0100 From: James Hogan To: Helge Deller CC: James Hogan , "James E.J. Bottomley" , , , John David Anglin Subject: [PATCH v4 2/4] parisc, metag: Do not hardcode maximum userspace stack size Date: Wed, 14 May 2014 13:52:46 +0100 Message-ID: <1400071968-21581-3-git-send-email-james.hogan@imgtec.com> X-Mailer: git-send-email 1.9.3 In-Reply-To: <1400071968-21581-1-git-send-email-james.hogan@imgtec.com> References: <1400071968-21581-1-git-send-email-james.hogan@imgtec.com> MIME-Version: 1.0 X-Originating-IP: [192.168.154.101] Sender: linux-parisc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-parisc@vger.kernel.org X-Spam-Status: No, score=-7.5 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=ham 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 From: Helge Deller This patch affects only architectures where the stack grows upwards (currently parisc and metag only). On those do not hardcode the maximum initial stack size to 1GB for 32-bit processes, but make it configurable via a config option. The main problem with the hardcoded stack size is, that we have two memory regions which grow upwards: stack and heap. To keep most of the memory available for heap in a flexmap memory layout, it makes no sense to hard allocate up to 1GB of the memory for stack which can't be used as heap then. This patch makes the stack size for 32-bit processes configurable and uses 80MB as default value which has been in use during the last few years on parisc and which hasn't showed any problems yet. Signed-off-by: Helge Deller Signed-off-by: James Hogan Cc: "James E.J. Bottomley" Cc: linux-parisc@vger.kernel.org Cc: linux-metag@vger.kernel.org Cc: John David Anglin --- v4 (James Hogan): - split out the metag stable fix, otherwise identical. v3 (James Hogan): - fix so that 64-bit parisc processes still use the 1GB limit. CONFIG_STACK_GROWSUP arches should provide a STACK_SIZE_MAX in their asm/processor.h, and for parisc it depends on USER_WIDE_MODE (whether the current process is 64-bit). v2 (James Hogan): - updated description to mention BUG on metag. - added custom range limit for METAG. - moved Kconfig symbol to mm/Kconfig and reworded. - fixed "matag" typo. --- arch/metag/include/asm/processor.h | 2 +- arch/parisc/include/asm/processor.h | 5 ++++- arch/parisc/kernel/sys_parisc.c | 6 +++--- mm/Kconfig | 15 +++++++++++++++ 4 files changed, 23 insertions(+), 5 deletions(-) diff --git a/arch/metag/include/asm/processor.h b/arch/metag/include/asm/processor.h index 3be8581af495..a8a37477c66e 100644 --- a/arch/metag/include/asm/processor.h +++ b/arch/metag/include/asm/processor.h @@ -23,7 +23,7 @@ #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 */ +#define STACK_SIZE_MAX (CONFIG_MAX_STACK_SIZE_MB*1024*1024) /* 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 86522ef09d52..d951c9681ab3 100644 --- a/arch/parisc/include/asm/processor.h +++ b/arch/parisc/include/asm/processor.h @@ -55,7 +55,10 @@ #define STACK_TOP TASK_SIZE #define STACK_TOP_MAX DEFAULT_TASK_SIZE -#define STACK_SIZE_MAX (1 << 30) /* 1 GB */ +/* Allow bigger stacks for 64-bit processes */ +#define STACK_SIZE_MAX (USER_WIDE_MODE \ + ? (1 << 30) /* 1 GB */ \ + : (CONFIG_MAX_STACK_SIZE_MB*1024*1024)) #endif diff --git a/arch/parisc/kernel/sys_parisc.c b/arch/parisc/kernel/sys_parisc.c index 31ffa9b55322..e1ffea2f9a0b 100644 --- a/arch/parisc/kernel/sys_parisc.c +++ b/arch/parisc/kernel/sys_parisc.c @@ -72,10 +72,10 @@ static unsigned long mmap_upper_limit(void) { unsigned long stack_base; - /* Limit stack size to 1GB - see setup_arg_pages() in fs/exec.c */ + /* Limit stack size - see setup_arg_pages() in fs/exec.c */ 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; return PAGE_ALIGN(STACK_TOP - stack_base); } diff --git a/mm/Kconfig b/mm/Kconfig index ebe5880c29d6..1b5a95f0fa01 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -581,3 +581,18 @@ config PGTABLE_MAPPING config GENERIC_EARLY_IOREMAP bool + +config MAX_STACK_SIZE_MB + int "Maximum user stack size for 32-bit processes (MB)" + default 80 + range 8 256 if METAG + range 8 2048 + depends on STACK_GROWSUP && (!64BIT || COMPAT) + help + This is the maximum stack size in Megabytes in the VM layout of 32-bit + user processes when the stack grows upwards (currently only on parisc + and metag arch). The stack will be located at the highest memory + address minus the given value, unless the RLIMIT_STACK hard limit is + changed to a smaller value in which case that is used. + + A sane initial value is 80 MB.