diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2008-02-16 14:05:01 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-02-26 12:56:06 +0100 |
| commit | f18edc95a37a901ffcbe91f5e05105f916a04fae (patch) | |
| tree | 66bb079a44a7bf997207cce8eb6b3c840082c45d | |
| parent | 12c247a6719987aad65f83158d2bb3e73c75c1f5 (diff) | |
x86: no robust/pi futex for real i386 CPUs
Real i386 CPUs do not have cmpxchg instructions. Catch it before
crashing on an invalid opcode.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| -rw-r--r-- | include/asm-x86/futex.h | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/include/asm-x86/futex.h b/include/asm-x86/futex.h index cd9f894dd2d..c9952ea9f69 100644 --- a/include/asm-x86/futex.h +++ b/include/asm-x86/futex.h @@ -102,6 +102,13 @@ futex_atomic_op_inuser(int encoded_op, int __user *uaddr) static inline int futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, int newval) { + +#if defined(CONFIG_X86_32) && !defined(CONFIG_X86_BSWAP) + /* Real i386 machines have no cmpxchg instruction */ + if (boot_cpu_data.x86 == 3) + return -ENOSYS; +#endif + if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int))) return -EFAULT; |