On Wed, May 22, 2013 at 03:59:01PM +0200, Arnd Bergmann wrote:
> On Thursday 16 May 2013, Michael S. Tsirkin wrote:
> > @@ -178,7 +178,7 @@ do { \
> > long __pu_err; \
> > __typeof__(*(ptr)) __user *__pu_addr = (ptr); \
> > if (!is_kernel_addr((unsigned long)__pu_addr)) \
> > - might_sleep(); \
> > + might_fault(); \
> > __chk_user_ptr(ptr); \
> > __put_user_size((x), __pu_addr, (size), __pu_err); \
> > __pu_err; \
> >
>
> Another observation:
>
> if (!is_kernel_addr((unsigned long)__pu_addr))
> might_sleep();
>
> is almost the same as
>
> might_fault();
>
> except that it does not call might_lock_read().
>
> The version above may have been put there intentionally and correctly, but
> if you want to replace it with might_fault(), you should remove the
> "if ()" condition.
>
> Arnd
Well not exactly. The non-inline might_fault checks the
current segment, not the address.
I'm guessing this is trying to do the same just without
pulling in segment_eq, but I'd like a confirmation
from more PPC maintainers.
Guys would you ack
- if (!is_kernel_addr((unsigned long)__pu_addr))
- might_fault();
+ might_fault();
on top of this patch?
Also, any volunteer to test this (not just test-build)?
--
MST
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