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author | Jeff Garzik <jeff@garzik.org> | 2006-03-29 17:18:49 -0500 |
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committer | Jeff Garzik <jeff@garzik.org> | 2006-03-29 17:18:49 -0500 |
commit | e02a4cabfcb9a999b74a2e2e6f13ffcb7ff2d606 (patch) | |
tree | 2f3db60be4c57eca2a4c3ab3f3122dcf1ec0c624 /include/asm-x86_64/futex.h | |
parent | 600511e86babe3727264a0883a3a264f6fb6caf5 (diff) | |
parent | f3cab8a0b1a772dc8b055b7affa567a366627c9e (diff) | |
download | op-kernel-dev-e02a4cabfcb9a999b74a2e2e6f13ffcb7ff2d606.zip op-kernel-dev-e02a4cabfcb9a999b74a2e2e6f13ffcb7ff2d606.tar.gz |
Merge branch 'master'
Diffstat (limited to 'include/asm-x86_64/futex.h')
-rw-r--r-- | include/asm-x86_64/futex.h | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/include/asm-x86_64/futex.h b/include/asm-x86_64/futex.h index 8602c09..9804bf0 100644 --- a/include/asm-x86_64/futex.h +++ b/include/asm-x86_64/futex.h @@ -94,5 +94,32 @@ futex_atomic_op_inuser (int encoded_op, int __user *uaddr) return ret; } +static inline int +futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, int newval) +{ + if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int))) + return -EFAULT; + + __asm__ __volatile__( + "1: " LOCK_PREFIX "cmpxchgl %3, %1 \n" + + "2: .section .fixup, \"ax\" \n" + "3: mov %2, %0 \n" + " jmp 2b \n" + " .previous \n" + + " .section __ex_table, \"a\" \n" + " .align 8 \n" + " .quad 1b,3b \n" + " .previous \n" + + : "=a" (oldval), "=m" (*uaddr) + : "i" (-EFAULT), "r" (newval), "0" (oldval) + : "memory" + ); + + return oldval; +} + #endif #endif |