arm_smmu_rpm_get() invokes pm_runtime_get_sync(), which increases the
refcount of the "smmu" even though the return value is less than 0.
The reference counting issue happens in several exception handling paths
of arm_smmu_iova_to_phys_hard(). When those error scenarios occur, the
function forgets to decrease the refcount of "smmu" increased by
arm_smmu_rpm_get(), causing a refcount leak.
Fix this issue by jumping to "out" label when those error scenarios
occur.
Signed-off-by: Xiyu Yang <xiyuyan...@fudan.edu.cn>
Signed-off-by: Xin Tan <tanxin....@gmail.com>
---
drivers/iommu/arm/arm-smmu/arm-smmu.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu.c
b/drivers/iommu/arm/arm-smmu/arm-smmu.c
index 6f72c4d208ca..023dcd72ed35 100644
--- a/drivers/iommu/arm/arm-smmu/arm-smmu.c
+++ b/drivers/iommu/arm/arm-smmu/arm-smmu.c
@@ -1271,10 +1271,11 @@ static phys_addr_t arm_smmu_iova_to_phys_hard(struct
iommu_domain *domain,
u64 phys;
unsigned long va, flags;
int ret, idx = cfg->cbndx;
+ phys_addr_t addr = 0;
ret = arm_smmu_rpm_get(smmu);
if (ret < 0)
- return 0;
+ goto out;
spin_lock_irqsave(&smmu_domain->cb_lock, flags);
va = iova & ~0xfffUL;
@@ -1290,6 +1291,7 @@ static phys_addr_t arm_smmu_iova_to_phys_hard(struct
iommu_domain *domain,
dev_err(dev,
"iova to phys timed out on %pad. Falling back to
software table walk.\n",
&iova);
+ arm_smmu_rpm_put(smmu);
return ops->iova_to_phys(ops, iova);
}
@@ -1298,12 +1300,14 @@ static phys_addr_t arm_smmu_iova_to_phys_hard(struct
iommu_domain *domain,
if (phys & ARM_SMMU_CB_PAR_F) {
dev_err(dev, "translation fault!\n");
dev_err(dev, "PAR = 0x%llx\n", phys);
- return 0;
+ goto out;
}
+ addr = (phys & GENMASK_ULL(39, 12)) | (iova & 0xfff);
+out:
arm_smmu_rpm_put(smmu);
- return (phys & GENMASK_ULL(39, 12)) | (iova & 0xfff);
+ return addr;
}
static phys_addr_t arm_smmu_iova_to_phys(struct iommu_domain *domain,
--
2.7.4
_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu
