Let's explicitly disable/enable preemption in the !CONFIG_SMP version of futex_atomic_cmpxchg_inatomic, to prepare for pagefault_disable() not touching preemption anymore. This is needed for this function to be callable from both, atomic and non-atomic context.
Otherwise we might break mutual exclusion when relying on a get_user()/ put_user() implementation. Signed-off-by: David Hildenbrand <[email protected]> --- include/asm-generic/futex.h | 2 ++ 1 file changed, 2 insertions(+) diff --git a/include/asm-generic/futex.h b/include/asm-generic/futex.h index 3586017..e56272c 100644 --- a/include/asm-generic/futex.h +++ b/include/asm-generic/futex.h @@ -107,6 +107,7 @@ futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, { u32 val; + preempt_disable(); if (unlikely(get_user(val, uaddr) != 0)) return -EFAULT; @@ -114,6 +115,7 @@ futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, return -EFAULT; *uval = val; + preempt_enable(); return 0; } -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
