Bug in _und_usr on dual-core ARM?

TAO HU tghk48 at motorola.com
Tue Jun 21 05:37:31 EDT 2011


Hi, Russell

Wouldn't it lead to oops with your patch?
We're trying avoid oops actually.

On Tue, Jun 21, 2011 at 5:15 PM, Russell King - ARM Linux
<linux at arm.linux.org.uk> wrote:
> On Tue, Jun 21, 2011 at 04:31:19PM +0800, TAO HU wrote:
>> Hi, All
>>
>> We got an issue on our OMAP4 SMP system.
>> Looks like __und_user(), which was triggered by a user space
>> exception, got a page fault hence lead to might_sleep() failure.
>
> Could you see whether this patch prevents the warning please.
>
> diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c
> index bc0e1d8..d52b940 100644
> --- a/arch/arm/mm/fault.c
> +++ b/arch/arm/mm/fault.c
> @@ -289,7 +289,7 @@ do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
>         * If we're in an interrupt or have no user
>         * context, we must not take the fault..
>         */
> -       if (in_atomic() || !mm)
> +       if (in_atomic() || irqs_disabled() || !mm)
>                goto no_context;
>
>        /*
>
>



-- 
Best Regards
Hu Tao



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