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@xxxxxxx>
Cc: Jason Wang <jasowang@xxxxxxxxxx>
Cc: Michael S. Tsirkin <mst@xxxxxxxxxx>
Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc: virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx
---
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@xxxxxxxxxx>
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