From 3aeb95d5b7839708a8d8e11aa274ee4d0d4042cc Mon Sep 17 00:00:00 2001 From: jia zhang Date: Sun, 23 Nov 2008 09:51:41 +0800 Subject: x86_64: fix the check in stack_overflow_check Impact: make stack overflow debug check and printout narrower stack_overflow_check() should consider the stack usage of pt_regs, and thus it could warn us in advance. Additionally, it looks better for the warning time to start at INITIAL_JIFFIES. Assuming that rsp gets close to the check point before interrupt arrives: when interrupt really happens, thread_info will be partly overrode. Signed-off-by: jia zhang Signed-off-by: Ingo Molnar --- arch/x86/kernel/irq_64.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) (limited to 'arch/x86/kernel/irq_64.c') diff --git a/arch/x86/kernel/irq_64.c b/arch/x86/kernel/irq_64.c index 60eb84eb77a0..b842fc82be15 100644 --- 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); -- cgit v1.2.3 From f377fa123d0ec621e8e361ecc3f2a8ee70e81a2e Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Sun, 23 Nov 2008 09:02:26 +0100 Subject: 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 file changed, 10 insertions(+), 15 deletions(-) (limited to 'arch/x86/kernel/irq_64.c') diff --git a/arch/x86/kernel/irq_64.c b/arch/x86/kernel/irq_64.c index b842fc82be15..1d3d0e71b044 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)) -- cgit v1.2.3