futex_atomic_cmpxchg_inatomic() is simply the 32-bit implementation of
user_atomic_cmpxchg_inatomic(), which in turn is simply a
generalization of the original code in
futex_atomic_cmpxchg_inatomic().
Use the newly generalized user_atomic_cmpxchg_inatomic() as the futex
implementation, too.
[ hpa: retain the inline in futex.h rather than changing it to a macro ]
Signed-off-by: Qiaowei Ren <qiaowei.ren@intel.com>
Link: http://lkml.kernel.org/r/1387002303-6620-2-git-send-email-qiaowei.ren@intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
static inline int futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
u32 oldval, u32 newval)
{
static inline int futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
u32 oldval, u32 newval)
{
- int ret = 0;
-
- if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
- return -EFAULT;
-
- asm volatile("\t" ASM_STAC "\n"
- "1:\t" LOCK_PREFIX "cmpxchgl %4, %2\n"
- "2:\t" ASM_CLAC "\n"
- "\t.section .fixup, \"ax\"\n"
- "3:\tmov %3, %0\n"
- "\tjmp 2b\n"
- "\t.previous\n"
- _ASM_EXTABLE(1b, 3b)
- : "+r" (ret), "=a" (oldval), "+m" (*uaddr)
- : "i" (-EFAULT), "r" (newval), "1" (oldval)
- : "memory"
- );
-
- *uval = oldval;
- return ret;
+ return user_atomic_cmpxchg_inatomic(uval, uaddr, oldval, newval);