Re: [PATCH 17/43] x86/irq/64: In the stack overflow warning, print the offending IP

[Borislav Petkov]

On Fri, Nov 24, 2017 at 06:23:45PM +0100, Ingo Molnar wrote:
> From: Andy Lutomirski <luto@xxxxxxxxxx>
> 
> In case something goes wrong with unwind (not unlikely in case of
> overflow), print the offending IP where we detected the overflow.
> 
> Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxx>
> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Cc: Borislav Petkov <bpetkov@xxxxxxx>
> Cc: Brian Gerst <brgerst@xxxxxxxxx>
> Cc: Dave Hansen <dave.hansen@xxxxxxxxx>
> Cc: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> Link: https://lkml.kernel.org/r/6fcf700cc5ee884fb739b67d1246ab4185c41409.1511497875.git.luto@xxxxxxxxxx
> Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
> ---
>  arch/x86/kernel/irq_64.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/x86/kernel/irq_64.c b/arch/x86/kernel/irq_64.c
> index 020efbf5786b..d86e344f5b3d 100644
> --- a/arch/x86/kernel/irq_64.c
> +++ b/arch/x86/kernel/irq_64.c
> @@ -57,10 +57,10 @@ static inline void stack_overflow_check(struct pt_regs *regs)
>  	if (regs->sp >= estack_top && regs->sp <= estack_bottom)
>  		return;
>  
> -	WARN_ONCE(1, "do_IRQ(): %s has overflown the kernel stack (cur:%Lx,sp:%lx,irq stk top-bottom:%Lx-%Lx,exception stk top-bottom:%Lx-%Lx)\n",
> +	WARN_ONCE(1, "do_IRQ(): %s has overflown the kernel stack (cur:%Lx,sp:%lx,irq stk top-bottom:%Lx-%Lx,exception stk top-bottom:%Lx-%Lx,ip:%pF)\n",
>  		current->comm, curbase, regs->sp,
>  		irq_stack_top, irq_stack_bottom,
> -		estack_top, estack_bottom);
> +		estack_top, estack_bottom, (void *)regs->ip);
>  
>  	if (sysctl_panic_on_stackoverflow)
>  		panic("low stack detected by irq handler - check messages\n");
> -- 

Reviewed-by: Borislav Petkov <bp@xxxxxxx>

Also move to the beginning of the patchset.

-- 
Regards/Gruss,
    Boris.

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