From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932267Ab1LENTZ (ORCPT ); Mon, 5 Dec 2011 08:19:25 -0500 Received: from terminus.zytor.com ([198.137.202.10]:57390 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932118Ab1LENTY (ORCPT ); Mon, 5 Dec 2011 08:19:24 -0500 Date: Mon, 5 Dec 2011 05:19:06 -0800 From: tip-bot for Mitsuo Hayasaka Message-ID: Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@redhat.com, rdunlap@xenotime.net, tglx@linutronix.de, mingo@elte.hu, mitsuo.hayasaka.hu@hitachi.com Reply-To: mingo@redhat.com, hpa@zytor.com, linux-kernel@vger.kernel.org, tglx@linutronix.de, rdunlap@xenotime.net, mitsuo.hayasaka.hu@hitachi.com, mingo@elte.hu In-Reply-To: <20111129060836.11076.12323.stgit@ltc219.sdl.hitachi.co.jp> References: <20111129060836.11076.12323.stgit@ltc219.sdl.hitachi.co.jp> To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/debug] x86: Panic on detection of stack overflow Git-Commit-ID: 55af77969fbd7a841838220ea2287432e0da8ae5 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.6 (terminus.zytor.com [127.0.0.1]); Mon, 05 Dec 2011 05:19:11 -0800 (PST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 55af77969fbd7a841838220ea2287432e0da8ae5 Gitweb: http://git.kernel.org/tip/55af77969fbd7a841838220ea2287432e0da8ae5 Author: Mitsuo Hayasaka AuthorDate: Tue, 29 Nov 2011 15:08:36 +0900 Committer: Ingo Molnar CommitDate: Mon, 5 Dec 2011 11:37:47 +0100 x86: Panic on detection of stack overflow Currently, messages are just output on the detection of stack overflow, which is not sufficient for systems that need a high reliability. This is because in general the overflow may corrupt data, and the additional corruption may occur due to reading them unless systems stop. This patch adds the sysctl parameter kernel.panic_on_stackoverflow and causes a panic when detecting the overflows of kernel, IRQ and exception stacks except user stack according to the parameter. It is disabled by default. Signed-off-by: Mitsuo Hayasaka Cc: yrl.pp-manager.tt@hitachi.com Cc: Randy Dunlap Cc: "H. Peter Anvin" Link: http://lkml.kernel.org/r/20111129060836.11076.12323.stgit@ltc219.sdl.hitachi.co.jp Signed-off-by: Ingo Molnar --- Documentation/sysctl/kernel.txt | 14 ++++++++++++++ arch/x86/kernel/irq_32.c | 2 ++ arch/x86/kernel/irq_64.c | 5 +++++ include/linux/kernel.h | 1 + kernel/sysctl.c | 9 +++++++++ 5 files changed, 31 insertions(+), 0 deletions(-) diff --git a/Documentation/sysctl/kernel.txt b/Documentation/sysctl/kernel.txt index 1f24636..6d8cd8b 100644 --- a/Documentation/sysctl/kernel.txt +++ b/Documentation/sysctl/kernel.txt @@ -49,6 +49,7 @@ show up in /proc/sys/kernel: - panic - panic_on_oops - panic_on_unrecovered_nmi +- panic_on_stackoverflow - pid_max - powersave-nap [ PPC only ] - printk @@ -393,6 +394,19 @@ Controls the kernel's behaviour when an oops or BUG is encountered. ============================================================== +panic_on_stackoverflow: + +Controls the kernel's behavior when detecting the overflows of +kernel, IRQ and exception stacks except a user stack. +This file shows up if CONFIG_DEBUG_STACKOVERFLOW is enabled. + +0: try to continue operation. + +1: panic immediately. + +============================================================== + + pid_max: PID allocation wrap value. When the kernel's next PID value diff --git a/arch/x86/kernel/irq_32.c b/arch/x86/kernel/irq_32.c index 7209070..e16e99eb 100644 --- a/arch/x86/kernel/irq_32.c +++ b/arch/x86/kernel/irq_32.c @@ -43,6 +43,8 @@ static void print_stack_overflow(void) { printk(KERN_WARNING "low stack detected by irq handler\n"); dump_stack(); + if (sysctl_panic_on_stackoverflow) + panic("low stack detected by irq handler - check messages\n"); } #else diff --git a/arch/x86/kernel/irq_64.c b/arch/x86/kernel/irq_64.c index 928a7e9..42552b0 100644 --- a/arch/x86/kernel/irq_64.c +++ b/arch/x86/kernel/irq_64.c @@ -26,6 +26,8 @@ EXPORT_PER_CPU_SYMBOL(irq_stat); DEFINE_PER_CPU(struct pt_regs *, irq_regs); EXPORT_PER_CPU_SYMBOL(irq_regs); +int sysctl_panic_on_stackoverflow; + /* * Probabilistic stack overflow check: * @@ -65,6 +67,9 @@ static inline void stack_overflow_check(struct pt_regs *regs) current->comm, curbase, regs->sp, irq_stack_top, irq_stack_bottom, estack_top, estack_bottom); + + if (sysctl_panic_on_stackoverflow) + panic("low stack detected by irq handler - check messages\n"); #endif } diff --git a/include/linux/kernel.h b/include/linux/kernel.h index e8b1597..ff83683 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -341,6 +341,7 @@ extern int panic_timeout; extern int panic_on_oops; extern int panic_on_unrecovered_nmi; extern int panic_on_io_nmi; +extern int sysctl_panic_on_stackoverflow; extern const char *print_tainted(void); extern void add_taint(unsigned flag); extern int test_taint(unsigned flag); diff --git a/kernel/sysctl.c b/kernel/sysctl.c index ae27196..f487f25 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -803,6 +803,15 @@ static struct ctl_table kern_table[] = { .mode = 0644, .proc_handler = proc_dointvec, }, +#ifdef CONFIG_DEBUG_STACKOVERFLOW + { + .procname = "panic_on_stackoverflow", + .data = &sysctl_panic_on_stackoverflow, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec, + }, +#endif { .procname = "bootloader_type", .data = &bootloader_type,