lkml.org 
[lkml]   [2016]   [Nov]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 3/3] tools/virtio: use {READ,WRITE}_ONCE() in uaccess.h
Date
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; \
})

--
2.7.4
\
 
 \ /
  Last update: 2016-11-24 11:27    [W:0.086 / U:0.452 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site