redonkable
/
alistair23-linux
1
0
Fork 0
Code Releases Activity

iommu/arm-smmu-v3: Use WRITE_ONCE() when changing validity of an STE 

[ Upstream commit d71e01716b ]

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>
5.4-rM2-2.2.x-imx-squashed
Will Deacon 2020-01-15 15:21:47 +00:00 committed by Greg Kroah-Hartman
parent 23d3f191a5
commit 480494e28a
1 changed files with 2 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
drivers/iommu/arm-smmu-v3.c
View File

@ -1643,7 +1643,8 @@ static void arm_smmu_write_strtab_ent(struct arm_smmu_master *master, u32 sid,
STRTAB_STE_1_EATS_TRANS));
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 */