On Wed, Mar 7, 2018 at 5:50 PM, Robin Murphy <robin.mur...@arm.com> wrote: > On 02/03/18 10:10, Vivek Gautam wrote: >> >> If we fail after initializing domain_context, we should destroy >> the context to free up resources. > > > Have another think about why the "problem" this patch caters for cannot ever > happen (hint: consider how domain->smmu is used in > arm_smmu_init_domain_context()). And then also about the really > catastrophically bad problem it actually introduces (hint: > "iommu_attach(domain, good_dev); iommu_attach(domain, bad_dev);")
Got it, we would end up destroying good_dev's domain context with this. Thanks regards Vivek > > Robin. > > >> Signed-off-by: Vivek Gautam <vivek.gau...@codeaurora.org> >> --- >> >> * New patch added in this series. >> >> drivers/iommu/arm-smmu.c | 7 ++++++- >> 1 file changed, 6 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c >> index 69e7c60792a8..ffc152c36002 100644 >> --- a/drivers/iommu/arm-smmu.c >> +++ b/drivers/iommu/arm-smmu.c >> @@ -1223,11 +1223,16 @@ static int arm_smmu_attach_dev(struct iommu_domain >> *domain, struct device *dev) >> dev_err(dev, >> "cannot attach to SMMU %s whilst already attached >> to domain on SMMU %s\n", >> dev_name(smmu_domain->smmu->dev), >> dev_name(smmu->dev)); >> - return -EINVAL; >> + ret = -EINVAL; >> + goto destroy_domain; >> } >> /* Looks ok, so add the device to the domain */ >> return arm_smmu_domain_add_master(smmu_domain, fwspec); >> + >> +destroy_domain: >> + arm_smmu_destroy_domain_context(domain); >> + return ret; >> } >> static int arm_smmu_map(struct iommu_domain *domain, unsigned long >> iova, >> > -- QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation
