Re: [PATCH v2] x86: Fix an RT MCE crash

[Corey Minyard <minyard@acm.org>]

I forgot to mention that this applies to v3.2-rt, v3.4-rt,
v3.10-rt, v3.12-rt, and v3.14-rt.  I didn't see a v3.16-rt.

-corey

On 07/06/2016 01:55 PM, minyard@acm.org wrote:
> From: Corey Minyard <cminyard@mvista.com>
>
> On some x86 systems an MCE interrupt would come in before the kernel
> was ready for it.  Looking at the latest RT code, it has similar
> (but not quite the same) code, except it adds a bool that tells if
> MCE handling is initialized.  That was required because they had
> switched to use swork instead of a kernel thread.  Here, just
> checking to see if the thread is NULL is good enough to see if
> MCE handling is initialized.
>
> Signed-off-by: Corey Minyard <cminyard@mvista.com>
> ---
>   arch/x86/kernel/cpu/mcheck/mce.c | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c
> index aaf4b9b..cc70d98 100644
> --- a/arch/x86/kernel/cpu/mcheck/mce.c
> +++ b/arch/x86/kernel/cpu/mcheck/mce.c
> @@ -1391,7 +1391,8 @@ static int mce_notify_work_init(void)
>   
>   static void mce_notify_work(void)
>   {
> -	wake_up_process(mce_notify_helper);
> +	if (mce_notify_helper)
> +		wake_up_process(mce_notify_helper);
>   }
>   #else
>   static void mce_notify_work(void)