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| author | Will Deacon <will.deacon@arm.com> | 2019-04-10 11:51:54 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-07-03 13:14:49 +0200 |
| commit | a319c8ff4f09cae9936385a9297b1b29165e2d8c (patch) | |
| tree | 785d9330c244d5f7e4f15d1a84b5bacc76a7f25d | |
| parent | 4423a82cbde399ada728c5d027972f20d64ae4ae (diff) | |
| download | linux-stable-a319c8ff4f09cae9936385a9297b1b29165e2d8c.tar.gz | |
futex: Update comments and docs about return values of arch futex code
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@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | Documentation/robust-futexes.txt | 3 | ||||
| -rw-r--r-- | include/asm-generic/futex.h | 8 |
2 files changed, 7 insertions, 4 deletions
diff --git a/Documentation/robust-futexes.txt b/Documentation/robust-futexes.txt index 6c42c75103eb6d..6361fb01c9c1e8 100644 --- a/Documentation/robust-futexes.txt +++ b/Documentation/robust-futexes.txt @@ -218,5 +218,4 @@ All other architectures should build just fine too - but they won't have 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. diff --git a/include/asm-generic/futex.h b/include/asm-generic/futex.h index fcb61b4659b39d..8666fe7f35d77d 100644 --- 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, |