#define USER_DS ((mm_segment_t) { -0x40000000000UL })
#define get_fs() (current_thread_info()->addr_limit)
-#define get_ds() (KERNEL_DS)
#define set_fs(x) (current_thread_info()->addr_limit = (x))
#define segment_eq(a, b) ((a).seg == (b).seg)
* Address valid if:
* - "addr" doesn't have any high-bits set
* - AND "size" doesn't have any high-bits set
- * - AND "addr+size" doesn't have any high-bits set
+ * - AND "addr+size-(size != 0)" doesn't have any high-bits set
* - OR we are in kernel mode.
*/
-#define __access_ok(addr, size) \
- ((get_fs().seg & (addr | size | (addr+size))) == 0)
+#define __access_ok(addr, size) ({ \
+ unsigned long __ao_a = (addr), __ao_b = (size); \
+ unsigned long __ao_end = __ao_a + __ao_b - !!__ao_b; \
+ (get_fs().seg & (__ao_a | __ao_b | __ao_end)) == 0; })
#define access_ok(addr, size) \
({ \