[PATCH 4.3 145/157] iommu/arm-smmu: Fix error checking for ASID and VMID allocation

From: Greg Kroah-Hartman
Date: Wed Jan 27 2016 - 13:30:00 EST


4.3-stable review patch. If anyone has any objections, please let me know.

------------------

From: Will Deacon <will.deacon@xxxxxxx>

commit c0733a2cf30c1e7923b6ad4f8df67941502923de upstream.

The bitmap allocator returns an int, which is one of the standard
negative values on failure. Rather than assigning this straight to a
u16 (like we do for the ASID and VMID callers), which means that we
won't detect failure correctly, use an int for the purposes of error
checking.

Signed-off-by: Will Deacon <will.deacon@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/iommu/arm-smmu-v3.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)

--- a/drivers/iommu/arm-smmu-v3.c
+++ b/drivers/iommu/arm-smmu-v3.c
@@ -1427,7 +1427,7 @@ static int arm_smmu_domain_finalise_s1(s
struct io_pgtable_cfg *pgtbl_cfg)
{
int ret;
- u16 asid;
+ int asid;
struct arm_smmu_device *smmu = smmu_domain->smmu;
struct arm_smmu_s1_cfg *cfg = &smmu_domain->s1_cfg;

@@ -1439,10 +1439,11 @@ static int arm_smmu_domain_finalise_s1(s
&cfg->cdptr_dma, GFP_KERNEL);
if (!cfg->cdptr) {
dev_warn(smmu->dev, "failed to allocate context descriptor\n");
+ ret = -ENOMEM;
goto out_free_asid;
}

- cfg->cd.asid = asid;
+ cfg->cd.asid = (u16)asid;
cfg->cd.ttbr = pgtbl_cfg->arm_lpae_s1_cfg.ttbr[0];
cfg->cd.tcr = pgtbl_cfg->arm_lpae_s1_cfg.tcr;
cfg->cd.mair = pgtbl_cfg->arm_lpae_s1_cfg.mair[0];
@@ -1456,7 +1457,7 @@ out_free_asid:
static int arm_smmu_domain_finalise_s2(struct arm_smmu_domain *smmu_domain,
struct io_pgtable_cfg *pgtbl_cfg)
{
- u16 vmid;
+ int vmid;
struct arm_smmu_device *smmu = smmu_domain->smmu;
struct arm_smmu_s2_cfg *cfg = &smmu_domain->s2_cfg;

@@ -1464,7 +1465,7 @@ static int arm_smmu_domain_finalise_s2(s
if (IS_ERR_VALUE(vmid))
return vmid;

- cfg->vmid = vmid;
+ cfg->vmid = (u16)vmid;
cfg->vttbr = pgtbl_cfg->arm_lpae_s2_cfg.vttbr;
cfg->vtcr = pgtbl_cfg->arm_lpae_s2_cfg.vtcr;
return 0;