diff options
| author | Will Deacon <will@kernel.org> | 2020-01-15 15:21:47 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-02-28 15:39:04 +0100 |
| commit | e3295cded4e8327dc8b254d65349956572d367d7 (patch) | |
| tree | 6e317d2984a3e3ad98c6ed8ddbeaba5aafcecaf3 /drivers/iommu | |
| parent | afd459796f6bd2db8bfeac39eb8a2b7c955a2b63 (diff) | |
iommu/arm-smmu-v3: Use WRITE_ONCE() when changing validity of an STE
[ Upstream commit d71e01716b3606a6648df7e5646ae12c75babde4 ]
If, for some bizarre reason, the compiler decided to split up the write
of STE DWORD 0, we could end up making a partial structure valid.
Although this probably won't happen, follow the example of the
context-descriptor code and use WRITE_ONCE() to ensure atomicity of the
write.
Reported-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/iommu')
| -rw-r--r-- | drivers/iommu/arm-smmu-v3.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c index eb9937225d64..6c10f307a1c9 100644 --- a/drivers/iommu/arm-smmu-v3.c +++ b/drivers/iommu/arm-smmu-v3.c @@ -1090,7 +1090,8 @@ static void arm_smmu_write_strtab_ent(struct arm_smmu_device *smmu, u32 sid, } arm_smmu_sync_ste_for_sid(smmu, sid); - dst[0] = cpu_to_le64(val); + /* See comment in arm_smmu_write_ctx_desc() */ + WRITE_ONCE(dst[0], cpu_to_le64(val)); arm_smmu_sync_ste_for_sid(smmu, sid); /* It's likely that we'll want to use the new STE soon */ |