On Fri, Aug 27, 2010 at 06:32:06PM +0900, jiang.adam@xxxxxxxxx wrote:
> diff --git a/arch/mips/Kconfig.debug b/arch/mips/Kconfig.debug
> index 43dc279..f437cd1 100644
> --- a/arch/mips/Kconfig.debug
> +++ b/arch/mips/Kconfig.debug
> @@ -67,6 +67,15 @@ config CMDLINE_OVERRIDE
>
> Normally, you will choose 'N' here.
>
> +config DEBUG_STACKOVERFLOW
> + bool "Check for stack overflows"
> + depends on DEBUG_KERNEL
> + help
> + This option will cause messages to be printed if free stack space
> + drops below a certain limit(2GB on MIPS). The debugging option
I better upgrade my meory then. 2GB is a LOTS :)
> + provides another way to check stack overflow happened on kernel mode
> + stack usually caused by nested interruption.
> +
> config DEBUG_STACK_USAGE
> bool "Enable stack utilization instrumentation"
> depends on DEBUG_KERNEL
> diff --git a/arch/mips/kernel/irq.c b/arch/mips/kernel/irq.c
> index c6345f5..d0b924d 100644
> --- a/arch/mips/kernel/irq.c
> +++ b/arch/mips/kernel/irq.c
> @@ -151,6 +151,26 @@ void __init init_IRQ(void)
> #endif
> }
>
> +#ifdef DEBUG_STACKOVERFLOW
> +static inline void check_stack_overflow(void)
> +{
> + long sp;
Addresses in Linux should always be unsigned long.
> +
> + __asm__ __volatile__("move %0, $sp" : "=r" (sp));
> + sp = sp & (THREAD_SIZE-1);
For THREAD_SIZE - 1 there is the symbol THREAD_MASK.
> + /* check for stack overflow: is there less than 2KB free? */
> + if (unlikely(sp < (sizeof(struct thread_info) + 2048))) {
Looks good otherwise, will queue.
Ralf
