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Message-ID: <4C762572.4070509@mvista.com>
Date:   Thu, 26 Aug 2010 12:27:30 +0400
From:   Sergei Shtylyov <sshtylyov@mvista.com>
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To:     Adam Jiang <jiang.adam@gmail.com>
CC:     ralf@linux-mips.org, dmitri.vorobiev@movial.com,
        wuzhangjin@gmail.com, ddaney@caviumnetworks.com,
        peterz@infradead.org, fweisbec@gmail.com, tj@kernel.org,
        tglx@linutronix.de, mingo@elte.hu, linux-mips@linux-mips.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH 3/3] mips: irq: add stackoverflow detection
References: <linux-kernel@vger.kernel.org> <1282794933-20639-1-git-send-email-jiang.adam@gmail.com>
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Hello.

Adam Jiang wrote:

> Add stackoverflow detection to mips arch

[...]

> diff --git a/arch/mips/kernel/irq.c b/arch/mips/kernel/irq.c
> index c6345f5..75c584d 100644
> --- a/arch/mips/kernel/irq.c
> +++ b/arch/mips/kernel/irq.c
> @@ -151,6 +151,25 @@ void __init init_IRQ(void)
>  #endif
>  }
>  
> +#ifdef CONFIG_DEBUG_STACKOVERFLOW
> +static inline void check_stack_overflow(void)
> +{
> +	long sp;
> +
> +	asm volatile("move %0, $sp" : "=r" (sp));
> +	sp = sp & (THREAD_SIZE-1);
> +
> +	/* check for stack overflow: is there less than 2KB free? */
> +	if (unlikely(sp < (sizeof(struct thread_info) + 2048))) {
> +		printk("do_IRQ: stack overflow: %ld\n",
> +		       sp - sizeof(struct thread_info));
> +		dump_stack();
> +	}
> +}
> +#else
> +static inline void check_stack_overflow(void)

    You didn't even try to compile with the option disabled -- you've missed {}.

> +#endif
> +
>  /*
>   * do_IRQ handles all normal device IRQ's (the special
>   * SMP cross-CPU interrupts have their own specific

WBR, Sergei