diff options
-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 cd9f894dd2d7..c9952ea9f698 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; |