x86: replace futex_atomic_cmpxchg_inatomic() with user_atomic_cmpxchg_inatomic

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>
This commit is contained in:
Qiaowei Ren 2013-12-14 14:25:03 +08:00 committed by H. Peter Anvin
parent f09174c501
commit 0ee3b6f87d

View File

@ -110,26 +110,7 @@ static inline int futex_atomic_op_inuser(int encoded_op, u32 __user *uaddr)
static inline int futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, static inline int futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
u32 oldval, u32 newval) u32 oldval, u32 newval)
{ {
int ret = 0; return user_atomic_cmpxchg_inatomic(uval, uaddr, oldval, newval);
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;
} }
#endif #endif