From 55af77969fbd7a841838220ea2287432e0da8ae5 Mon Sep 17 00:00:00 2001 From: Mitsuo Hayasaka Date: Tue, 29 Nov 2011 15:08:36 +0900 Subject: 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 --- arch/x86/kernel/irq_32.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'arch/x86/kernel/irq_32.c') diff --git a/arch/x86/kernel/irq_32.c b/arch/x86/kernel/irq_32.c index 72090705a656..e16e99ebd7ad 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 -- cgit v1.2.3 From 53b5650273fea486ac8ac6c1d1e9a6cd17aa31ca Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Mon, 5 Dec 2011 12:25:44 +0100 Subject: x86: Fix the 32-bit stackoverflow-debug build The panic_on_stackoverflow variable needs to be avilable on the 32-bit side as well ... Cc: Mitsuo Hayasaka 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 --- arch/x86/kernel/irq_32.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'arch/x86/kernel/irq_32.c') diff --git a/arch/x86/kernel/irq_32.c b/arch/x86/kernel/irq_32.c index e16e99ebd7ad..40fc86161d92 100644 --- a/arch/x86/kernel/irq_32.c +++ b/arch/x86/kernel/irq_32.c @@ -28,6 +28,9 @@ DEFINE_PER_CPU(struct pt_regs *, irq_regs); EXPORT_PER_CPU_SYMBOL(irq_regs); #ifdef CONFIG_DEBUG_STACKOVERFLOW + +int sysctl_panic_on_stackoverflow __read_mostly; + /* Debugging check for stack overflow: is there less than 1KB free? */ static int check_stack_overflow(void) { -- cgit v1.2.3