When fall-through warnings was enabled by default, commit d93512ef0f0e ("Makefile: Globally enable fall-through warning"), the following warning was starting to show up:
../drivers/iommu/arm-smmu-v3.c: In function ‘arm_smmu_write_strtab_ent’: ../drivers/iommu/arm-smmu-v3.c:1189:7: warning: this statement may fall through [-Wimplicit-fallthrough=] if (disable_bypass) ^ ../drivers/iommu/arm-smmu-v3.c:1191:3: note: here default: ^~~~~~~
Rework so that the compiler doesn't warn about fall-through. Make it clearer by calling 'BUG()' when disable_bypass is set, and always 'break;'
Cc: stable@vger.kernel.org # v4.2+ Fixes: 5bc0a11664e1 ("iommu/arm-smmu: Don't BUG() if we find aborting STEs with disable_bypass") Signed-off-by: Anders Roxell anders.roxell@linaro.org --- drivers/iommu/arm-smmu-v3.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c index a9a9fabd3968..8e5f0565996d 100644 --- a/drivers/iommu/arm-smmu-v3.c +++ b/drivers/iommu/arm-smmu-v3.c @@ -1186,8 +1186,9 @@ static void arm_smmu_write_strtab_ent(struct arm_smmu_master *master, u32 sid, ste_live = true; break; case STRTAB_STE_0_CFG_ABORT: - if (disable_bypass) - break; + if (!disable_bypass) + BUG(); + break; default: BUG(); /* STE corruption */ }