From 9d55b9923a1b7ea8193b8875c57ec940dc2ff027 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Fri, 1 Feb 2008 17:45:14 +0100 Subject: [PATCH] x86: replace LOCK_PREFIX in futex.h The exception fixup for the futex macros __futex_atomic_op1/2 and futex_atomic_cmpxchg_inatomic() is missing an entry when the lock prefix is replaced by a NOP via SMP alternatives. Chuck Ebert tracked this down from the information provided in: https://bugzilla.redhat.com/show_bug.cgi?id=429412 A possible solution would be to add another fixup after the LOCK_PREFIX, so both the LOCK and NOP case have their own entry in the exception table, but it's not really worth the trouble. Simply replace LOCK_PREFIX with lock and keep those untouched by SMP alternatives. Signed-off-by: Thomas Gleixner Signed-off-by: Ingo Molnar --- include/asm-x86/futex.h | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/include/asm-x86/futex.h b/include/asm-x86/futex.h index 62828d63f1b..9d919264923 100644 --- a/include/asm-x86/futex.h +++ b/include/asm-x86/futex.h @@ -30,7 +30,7 @@ "1: movl %2, %0\n \ movl %0, %3\n" \ insn "\n" \ -"2: " LOCK_PREFIX "cmpxchgl %3, %2\n \ +"2: lock; cmpxchgl %3, %2\n \ jnz 1b\n \ 3: .section .fixup,\"ax\"\n \ 4: mov %5, %1\n \ @@ -72,7 +72,7 @@ futex_atomic_op_inuser(int encoded_op, int __user *uaddr) __futex_atomic_op1("xchgl %0, %2", ret, oldval, uaddr, oparg); break; case FUTEX_OP_ADD: - __futex_atomic_op1(LOCK_PREFIX "xaddl %0, %2", ret, oldval, + __futex_atomic_op1("lock; xaddl %0, %2", ret, oldval, uaddr, oparg); break; case FUTEX_OP_OR: @@ -111,8 +111,8 @@ futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, int newval) return -EFAULT; __asm__ __volatile__( - "1: " LOCK_PREFIX "cmpxchgl %3, %1 \n" + "1: lock; cmpxchgl %3, %1 \n" "2: .section .fixup, \"ax\" \n" "3: mov %2, %0 \n" " jmp 2b \n" -- 2.41.1