Re: [PATCH 13/18] powerpc/uaccess: fix sparse errors

Benjamin Herrenschmidt
2014-12-15T01:38:22Z

On Mon, 2014-12-15 at 11:05 +1100, Benjamin Herrenschmidt wrote:
> On Sun, 2014-12-14 at 18:52 +0200, Michael S. Tsirkin wrote:
> > virtio wants to read bitwise types from userspace using get_user. At the
> > moment this triggers sparse errors, since the value is passed through an
> > integer.
> >
> > Fix that up using __force.
>
> You mean bitfields ? Argh ... we should just remove them from the
> compiler and be done with it :-(

Oh... no I suppose you actually meant explicit endian fields, ie, __be32
or __le32 right ? Ack on that. It sucks a bit but I think it's
acceptable.

Cheers,
Ben.

> Ben.
>
> > Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> > ---
> > arch/powerpc/include/asm/uaccess.h | 6 +++---
> > 1 file changed, 3 insertions(+), 3 deletions(-)
> >
> > diff --git a/arch/powerpc/include/asm/uaccess.h b/arch/powerpc/include/asm/uaccess.h
> > index 9485b43..a0c071d 100644
> > --- a/arch/powerpc/include/asm/uaccess.h
> > +++ b/arch/powerpc/include/asm/uaccess.h
> > @@ -284,7 +284,7 @@ do { \
> > if (!is_kernel_addr((unsigned long)__gu_addr)) \
> > might_fault(); \
> > __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \
> > - (x) = (__typeof__(*(ptr)))__gu_val; \
> > + (x) = (__force __typeof__(*(ptr)))__gu_val; \
> > __gu_err; \
> > })
> > #endif /* __powerpc64__ */
> > @@ -297,7 +297,7 @@ do { \
> > might_fault(); \
> > if (access_ok(VERIFY_READ, __gu_addr, (size))) \
> > __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \
> > - (x) = (__typeof__(*(ptr)))__gu_val; \
> > + (x) = (__force __typeof__(*(ptr)))__gu_val; \
> > __gu_err; \
> > })
> >
> > @@ -308,7 +308,7 @@ do { \
> > const __typeof__(*(ptr)) __user *__gu_addr = (ptr); \
> > __chk_user_ptr(ptr); \
> > __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \
> > - (x) = (__typeof__(*(ptr)))__gu_val; \
> > + (x) = (__force __typeof__(*(ptr)))__gu_val; \
> > __gu_err; \
> > })
> >
>