Commit 3aeb95d5 authored Nov 23, 2008 by jia zhang Committed by Ingo Molnar Nov 23, 2008

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 <jia.zhang2008@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

parent ca9eed76

arch/x86/kernel/irq_64.c

+4 −3

Original line number	Diff line number	Diff line
		@@ -29,10 +29,11 @@
		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 &&
		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);

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