From: Will Deacon <will.deacon@xxxxxxx> commit 427503519739e779c0db8afe876c1b33f3ac60ae upstream. The architecture implementations of 'arch_futex_atomic_op_inuser()' and 'futex_atomic_cmpxchg_inatomic()' are permitted to return only -EFAULT, -EAGAIN or -ENOSYS in the case of failure. Update the comments in the asm-generic/ implementation and also a stray reference in the robust futex documentation. Signed-off-by: Will Deacon <will.deacon@xxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- Documentation/robust-futexes.txt | 3 +-- include/asm-generic/futex.h | 8 ++++++-- 2 files changed, 7 insertions(+), 4 deletions(-) --- a/Documentation/robust-futexes.txt +++ b/Documentation/robust-futexes.txt @@ -218,5 +218,4 @@ All other architectures should build jus the new syscalls yet. Architectures need to implement the new futex_atomic_cmpxchg_inatomic() -inline function before writing up the syscalls (that function returns --ENOSYS right now). +inline function before writing up the syscalls. --- a/include/asm-generic/futex.h +++ b/include/asm-generic/futex.h @@ -23,7 +23,9 @@ * * Return: * 0 - On success - * <0 - On error + * -EFAULT - User access resulted in a page fault + * -EAGAIN - Atomic operation was unable to complete due to contention + * -ENOSYS - Operation not supported */ static inline int arch_futex_atomic_op_inuser(int op, u32 oparg, int *oval, u32 __user *uaddr) @@ -85,7 +87,9 @@ out_pagefault_enable: * * Return: * 0 - On success - * <0 - On error + * -EFAULT - User access resulted in a page fault + * -EAGAIN - Atomic operation was unable to complete due to contention + * -ENOSYS - Function not implemented (only if !HAVE_FUTEX_CMPXCHG) */ static inline int futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
