Re: [PATCH 3/5] HWPOISON: Handle hwpoison in current process

[Chen Gong <gong.chen@linux.intel.com>]

于 2011/9/1 6:25, Luck, Tony 写道:
> From: Andi Kleen<andi@firstfloor.org>
>
> When hardware poison handles the current process use
> a forced signal with _AR severity.
>
> [Tony: changed some function names .. the "_ao" suffix was no longer meaningful]
>
> Signed-off-by: Andi Kleen<ak@linux.intel.com>
> Signed-off-by: Tony Luck<tony.luck@intel.com>
> ---
>   mm/memory-failure.c |   39 ++++++++++++++++++++++-----------------
>   1 files changed, 22 insertions(+), 17 deletions(-)
>
> diff --git a/mm/memory-failure.c b/mm/memory-failure.c
> index 2b43ba0..6ccb8a6 100644
> --- a/mm/memory-failure.c
> +++ b/mm/memory-failure.c
> @@ -186,33 +186,38 @@ int hwpoison_filter(struct page *p)
>   EXPORT_SYMBOL_GPL(hwpoison_filter);
>
>   /*
> - * Send all the processes who have the page mapped an ``action optional''
> - * signal.
> + * Send one process who has the page mapped a SIGBUS. It might
> + * be able to catch it and initiate its own task level recovery.
>    */
> -static int kill_proc_ao(struct task_struct *t, unsigned long addr, int trapno,
> +static int user_recovery(struct task_struct *t, unsigned long addr, int trapno,
>   			unsigned long pfn, struct page *page)
>   {
>   	struct siginfo si;
>   	int ret;
>
>   	printk(KERN_ERR
> -		"MCE %#lx: Killing %s:%d early due to hardware memory corruption\n",
> -		pfn, t->comm, t->pid);
> +		"MCE %#lx: Killing %s:%d due to hardware memory corruption\n",
> +	       pfn, t->comm, t->pid);
>   	si.si_signo = SIGBUS;
>   	si.si_errno = 0;
> -	si.si_code = BUS_MCEERR_AO;
>   	si.si_addr = (void *)addr;
>   #ifdef __ARCH_SI_TRAPNO
>   	si.si_trapno = trapno;
>   #endif
>   	si.si_addr_lsb = compound_trans_order(compound_head(page)) + PAGE_SHIFT;
> -	/*
> -	 * Don't use force here, it's convenient if the signal
> -	 * can be temporarily blocked.
> -	 * This could cause a loop when the user sets SIGBUS
> -	 * to SIG_IGN, but hopefully no one will do that?
> -	 */
> -	ret = send_sig_info(SIGBUS,&si, t);  /* synchronous? */
> +	if (t == current) {
> +		si.si_code = BUS_MCEERR_AR;
> +		ret = force_sig_info(SIGBUS,&si, t);
> +	} else {
> +		/*
> +		 * Don't use force here, it's convenient if the signal
> +		 * can be temporarily blocked.
> +		 * This could cause a loop when the user sets SIGBUS
> +		 * to SIG_IGN, but hopefully noone will do that?
                                              ^^^^^
spelling error