Messages in this thread | | | Subject | Re: [PATCH 3/3] tools/virtio: use {READ,WRITE}_ONCE() in uaccess.h | From | Jason Wang <> | Date | Fri, 25 Nov 2016 10:40:48 +0800 |
| |
On 2016年11月24日 18:25, Mark Rutland wrote: > As a step towards killing off ACCESS_ONCE, use {READ,WRITE}_ONCE() for the > virtio tools uaccess primitives, pulling these in from <linux/compiler.h>. > > With this done, we can kill off the now-unused ACCESS_ONCE() definition. > > Signed-off-by: Mark Rutland <mark.rutland@arm.com> > Cc: Jason Wang <jasowang@redhat.com> > Cc: Michael S. Tsirkin <mst@redhat.com> > Cc: linux-kernel@vger.kernel.org > Cc: virtualization@lists.linux-foundation.org > --- > tools/virtio/linux/uaccess.h | 9 +++++---- > 1 file changed, 5 insertions(+), 4 deletions(-) > > diff --git a/tools/virtio/linux/uaccess.h b/tools/virtio/linux/uaccess.h > index 0a578fe..fa05d01 100644 > --- a/tools/virtio/linux/uaccess.h > +++ b/tools/virtio/linux/uaccess.h > @@ -1,8 +1,9 @@ > #ifndef UACCESS_H > #define UACCESS_H > -extern void *__user_addr_min, *__user_addr_max; > > -#define ACCESS_ONCE(x) (*(volatile typeof(x) *)&(x)) > +#include <linux/compiler.h> > + > +extern void *__user_addr_min, *__user_addr_max; > > static inline void __chk_user_ptr(const volatile void *p, size_t size) > { > @@ -13,7 +14,7 @@ static inline void __chk_user_ptr(const volatile void *p, size_t size) > ({ \ > typeof(ptr) __pu_ptr = (ptr); \ > __chk_user_ptr(__pu_ptr, sizeof(*__pu_ptr)); \ > - ACCESS_ONCE(*(__pu_ptr)) = x; \ > + WRITE_ONCE(*(__pu_ptr), x); \ > 0; \ > }) > > @@ -21,7 +22,7 @@ static inline void __chk_user_ptr(const volatile void *p, size_t size) > ({ \ > typeof(ptr) __pu_ptr = (ptr); \ > __chk_user_ptr(__pu_ptr, sizeof(*__pu_ptr)); \ > - x = ACCESS_ONCE(*(__pu_ptr)); \ > + x = READ_ONCE(*(__pu_ptr)); \ > 0; \ > }) >
Reviewed-by: Jason Wang <jasowang@redhat.com>
| |