linux-stable/tools/virtio/linux/uaccess.h
Mark Rutland ea9156fb3b tools/virtio: use {READ,WRITE}_ONCE() in uaccess.h
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
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Jason Wang <jasowang@redhat.com>
2016-12-16 00:13:37 +02:00

51 lines
1.1 KiB
C

#ifndef UACCESS_H
#define UACCESS_H
#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)
{
assert(p >= __user_addr_min && p + size <= __user_addr_max);
}
#define put_user(x, ptr) \
({ \
typeof(ptr) __pu_ptr = (ptr); \
__chk_user_ptr(__pu_ptr, sizeof(*__pu_ptr)); \
WRITE_ONCE(*(__pu_ptr), x); \
0; \
})
#define get_user(x, ptr) \
({ \
typeof(ptr) __pu_ptr = (ptr); \
__chk_user_ptr(__pu_ptr, sizeof(*__pu_ptr)); \
x = READ_ONCE(*(__pu_ptr)); \
0; \
})
static void volatile_memcpy(volatile char *to, const volatile char *from,
unsigned long n)
{
while (n--)
*(to++) = *(from++);
}
static inline int copy_from_user(void *to, const void __user volatile *from,
unsigned long n)
{
__chk_user_ptr(from, n);
volatile_memcpy(to, from, n);
return 0;
}
static inline int copy_to_user(void __user volatile *to, const void *from,
unsigned long n)
{
__chk_user_ptr(to, n);
volatile_memcpy(to, from, n);
return 0;
}
#endif /* UACCESS_H */