diff options
| author | Mark Rutland <[email protected]> | 2023-06-05 08:00:58 +0100 |
|---|---|---|
| committer | Peter Zijlstra <[email protected]> | 2023-06-05 09:57:13 +0200 |
| commit | dda5f312bb09e56e7a1c3e3851f2000eb2e9c879 (patch) | |
| tree | 2c5d77a688caffdffb4b516c1e6b00baeadb1259 /arch/arm/lib/testsetbit.S | |
| parent | 497cc42bf53b55185ab3d39c634fbf09eb6681ae (diff) | |
locking/atomic: arm: fix sync ops
The sync_*() ops on arch/arm are defined in terms of the regular bitops
with no special handling. This is not correct, as UP kernels elide
barriers for the fully-ordered operations, and so the required ordering
is lost when such UP kernels are run under a hypervsior on an SMP
system.
Fix this by defining sync ops with the required barriers.
Note: On 32-bit arm, the sync_*() ops are currently only used by Xen,
which requires ARMv7, but the semantics can be implemented for ARMv6+.
Fixes: e54d2f61528165bb ("xen/arm: sync_bitops")
Signed-off-by: Mark Rutland <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Diffstat (limited to 'arch/arm/lib/testsetbit.S')
| -rw-r--r-- | arch/arm/lib/testsetbit.S | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/arm/lib/testsetbit.S b/arch/arm/lib/testsetbit.S index f3192e55acc8..649dbab65d8d 100644 --- a/arch/arm/lib/testsetbit.S +++ b/arch/arm/lib/testsetbit.S @@ -10,3 +10,7 @@ .text testop _test_and_set_bit, orreq, streq + +#if __LINUX_ARM_ARCH__ >= 6 +sync_testop _sync_test_and_set_bit, orreq, streq +#endif |