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Subject: Re: [PATCH v3 1/3] init/main.c: Give init_task a canary
From: Michael Ellerman <mpe@ellerman.id.au>
To: Aaron Tomlin <atomlin@redhat.com>
Date: Fri, 12 Sep 2014 17:28:56 +1000
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On Thu, 2014-09-11 at 16:41 +0100, Aaron Tomlin wrote:
> Tasks get their end of stack set to STACK_END_MAGIC with the
> aim to catch stack overruns. Currently this feature does not
> apply to init_task. This patch removes this restriction.
> 
> diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c
> index 51ab9e7..35d0760c 100644
> --- a/arch/powerpc/mm/fault.c
> +++ b/arch/powerpc/mm/fault.c
> @@ -30,7 +30,6 @@
>  #include <linux/kprobes.h>
>  #include <linux/kdebug.h>
>  #include <linux/perf_event.h>
> -#include <linux/magic.h>
>  #include <linux/ratelimit.h>
>  #include <linux/context_tracking.h>
>  
> @@ -538,7 +537,7 @@ void bad_page_fault(struct pt_regs *regs, unsigned long address, int sig)
>  		regs->nip);
>  
>  	stackend = end_of_stack(current);
> -	if (current != &init_task && *stackend != STACK_END_MAGIC)
> +	if (*stackend != STACK_END_MAGIC)
>  		printk(KERN_ALERT "Thread overran stack, or stack corrupted\n");

This part looks fine.

Acked-by: Michael Ellerman <mpe@ellerman.id.au>

cheers