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| author | Thomas Gleixner <tglx@linutronix.de> | 2008-02-01 17:45:14 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-02-01 17:45:14 +0100 |
| commit | 9d55b9923a1b7ea8193b8875c57ec940dc2ff027 (patch) | |
| tree | c80e51cc63c1e2316d4419b8644ff8359b8586f6 | |
| parent | tick-sched: add more debug information (diff) | |
| download | linux-9d55b9923a1b7ea8193b8875c57ec940dc2ff027.tar.xz linux-9d55b9923a1b7ea8193b8875c57ec940dc2ff027.zip | |
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 <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
| -rw-r--r-- | include/asm-x86/futex.h | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/include/asm-x86/futex.h b/include/asm-x86/futex.h index 62828d63f1b1..9d919264923a 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" |