From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757985AbYKWIIh (ORCPT ); Sun, 23 Nov 2008 03:08:37 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752655AbYKWII2 (ORCPT ); Sun, 23 Nov 2008 03:08:28 -0500 Received: from mx3.mail.elte.hu ([157.181.1.138]:41069 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752411AbYKWII1 (ORCPT ); Sun, 23 Nov 2008 03:08:27 -0500 Date: Sun, 23 Nov 2008 09:08:16 +0100 From: Ingo Molnar To: jia zhang Cc: linux-kernel@vger.kernel.org, tglx@linutronix.de, hpa@zytor.com, Arjan van de Ven , Alexander van Heukelum Subject: [PATCH] x86: clean up stack overflow debug check Message-ID: <20081123080816.GA30453@elte.hu> References: <4928B72D.20901@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4928B72D.20901@gmail.com> User-Agent: Mutt/1.5.18 (2008-05-17) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.3 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * jia zhang wrote: > stack_overflow_check() should consider the stack usage of pt_regs, > and thus it could warn us in advance. Additionally, it looks a bit > good that the warning time starts at INITIAL_JIFFIES. > > Signed-off-by: jia zhang > --- > Assume at the moment rsp get close to the check point before > interrupt arrives. When interrupt really happens, thread_info will > be partly overrode. > > arch/x86/kernel/irq_64.c | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) > > --- a/arch/x86/kernel/irq_64.c > +++ b/arch/x86/kernel/irq_64.c > @@ -29,11 +29,12 @@ > static inline void stack_overflow_check(struct pt_regs *regs) > { > u64 curbase = (u64)task_stack_page(current); > - static unsigned long warned = -60*HZ; > + static unsigned long warned = INITIAL_JIFFIES - 60*HZ; > > if (regs->sp >= curbase && regs->sp <= curbase + THREAD_SIZE && > - regs->sp < curbase + sizeof(struct thread_info) + 128 && > - time_after(jiffies, warned + 60*HZ)) { > + regs->sp < curbase + sizeof(struct thread_info) + > + sizeof(struct pt_regs) + 128 && > + time_after(jiffies, warned + 60*HZ)) { > printk("do_IRQ: %s near stack overflow (cur:%Lx,sp:%lx)\n", > current->comm, curbase, regs->sp); > show_stack(NULL,NULL); applied to tip/x86/debug, thanks! I also applied the clean up patch below on top of your fix. Ingo -----------------> >>From f377fa123d0ec621e8e361ecc3f2a8ee70e81a2e Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Sun, 23 Nov 2008 09:02:26 +0100 Subject: [PATCH] x86: clean up stack overflow debug check Impact: cleanup Simplify the irq-sampled stack overflow debug check: - eliminate an #idef - use WARN_ONCE() to emit a single warning (all bets are off after the first such warning anyway) Signed-off-by: Ingo Molnar --- arch/x86/kernel/irq_64.c | 25 ++++++++++--------------- 1 files changed, 10 insertions(+), 15 deletions(-) diff --git a/arch/x86/kernel/irq_64.c b/arch/x86/kernel/irq_64.c index b842fc8..1d3d0e7 100644 --- a/arch/x86/kernel/irq_64.c +++ b/arch/x86/kernel/irq_64.c @@ -18,7 +18,6 @@ #include #include -#ifdef CONFIG_DEBUG_STACKOVERFLOW /* * Probabilistic stack overflow check: * @@ -28,20 +27,18 @@ */ static inline void stack_overflow_check(struct pt_regs *regs) { +#ifdef CONFIG_DEBUG_STACKOVERFLOW u64 curbase = (u64)task_stack_page(current); - static unsigned long warned = INITIAL_JIFFIES - 60*HZ; - - if (regs->sp >= curbase && regs->sp <= curbase + THREAD_SIZE && - regs->sp < curbase + sizeof(struct thread_info) + - sizeof(struct pt_regs) + 128 && - time_after(jiffies, warned + 60*HZ)) { - printk("do_IRQ: %s near stack overflow (cur:%Lx,sp:%lx)\n", - current->comm, curbase, regs->sp); - show_stack(NULL,NULL); - warned = jiffies; - } -} + + WARN_ONCE(regs->sp >= curbase && + regs->sp <= curbase + THREAD_SIZE && + regs->sp < curbase + sizeof(struct thread_info) + + sizeof(struct pt_regs) + 128, + + "do_IRQ: %s near stack overflow (cur:%Lx,sp:%lx)\n", + current->comm, curbase, regs->sp); #endif +} /* * do_IRQ handles all normal device IRQ's (the special @@ -61,9 +58,7 @@ asmlinkage unsigned int do_IRQ(struct pt_regs *regs) irq_enter(); irq = __get_cpu_var(vector_irq)[vector]; -#ifdef CONFIG_DEBUG_STACKOVERFLOW stack_overflow_check(regs); -#endif desc = irq_to_desc(irq); if (likely(desc))