| Message ID | 17-v1-5f734af130a3+34f-iommu_fwspec_jgg@nvidia.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Solve iommu probe races around iommu_fwspec | expand |
On 2023/11/4 0:45, Jason Gunthorpe wrote: > A perfect driver would only call dev_iommu_priv_set() from its probe > callback. We've made it functionally correct to call it from the of_xlate > by adding a lock around that call. > > lockdep assert that iommu_probe_device_lock is held to discourage misuse. > > Exclude PPC kernels with CONFIG_FSL_PAMU turned on because FSL_PAMU uses a > global static for its priv and abuses priv for its domain. > > Remove the pointless stores of NULL, all these are on paths where the core > code will free dev->iommu after the op returns. > > Signed-off-by: Jason Gunthorpe<jgg@nvidia.com> > --- > drivers/iommu/amd/iommu.c | 2 -- > drivers/iommu/apple-dart.c | 1 - > drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 1 - > drivers/iommu/arm/arm-smmu/arm-smmu.c | 1 - > drivers/iommu/intel/iommu.c | 2 -- > drivers/iommu/iommu.c | 9 +++++++++ > drivers/iommu/omap-iommu.c | 1 - > include/linux/iommu.h | 5 +---- > 8 files changed, 10 insertions(+), 12 deletions(-) Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com> Best regards, baolu
Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com>
diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c index 089886485895bc..604056eb0f5f8a 100644 --- a/drivers/iommu/amd/iommu.c +++ b/drivers/iommu/amd/iommu.c @@ -549,8 +549,6 @@ static void amd_iommu_uninit_device(struct device *dev) if (dev_data->domain) detach_device(dev); - dev_iommu_priv_set(dev, NULL); - /* * We keep dev_data around for unplugged devices and reuse it when the * device is re-plugged - not doing so would introduce a ton of races. diff --git a/drivers/iommu/apple-dart.c b/drivers/iommu/apple-dart.c index ee05f4824bfad1..56cfc33042e0b5 100644 --- a/drivers/iommu/apple-dart.c +++ b/drivers/iommu/apple-dart.c @@ -740,7 +740,6 @@ static void apple_dart_release_device(struct device *dev) { struct apple_dart_master_cfg *cfg = dev_iommu_priv_get(dev); - dev_iommu_priv_set(dev, NULL); kfree(cfg); } diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c index b1309f04ebc0d9..df81fcd25a75b0 100644 --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c @@ -2698,7 +2698,6 @@ static struct iommu_device *arm_smmu_probe_device(struct device *dev) err_free_master: kfree(master); - dev_iommu_priv_set(dev, NULL); return ERR_PTR(ret); } diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu.c b/drivers/iommu/arm/arm-smmu/arm-smmu.c index 8c4a60d8e5d522..6fc040a4168aa3 100644 --- a/drivers/iommu/arm/arm-smmu/arm-smmu.c +++ b/drivers/iommu/arm/arm-smmu/arm-smmu.c @@ -1423,7 +1423,6 @@ static void arm_smmu_release_device(struct device *dev) arm_smmu_rpm_put(cfg->smmu); - dev_iommu_priv_set(dev, NULL); kfree(cfg); } diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c index d5d191a71fe0d5..890c2cc9759b51 100644 --- a/drivers/iommu/intel/iommu.c +++ b/drivers/iommu/intel/iommu.c @@ -4401,7 +4401,6 @@ static struct iommu_device *intel_iommu_probe_device(struct device *dev) ret = intel_pasid_alloc_table(dev); if (ret) { dev_err(dev, "PASID table allocation failed\n"); - dev_iommu_priv_set(dev, NULL); kfree(info); return ERR_PTR(ret); } @@ -4419,7 +4418,6 @@ static void intel_iommu_release_device(struct device *dev) dmar_remove_one_dev_info(dev); intel_pasid_free_table(dev); intel_iommu_debugfs_remove_dev(info); - dev_iommu_priv_set(dev, NULL); kfree(info); set_dma_ops(dev, NULL); } diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 1cf9f62c047c7d..254cde45bc5c1c 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -387,6 +387,15 @@ static u32 dev_iommu_get_max_pasids(struct device *dev) return min_t(u32, max_pasids, dev->iommu->iommu_dev->max_pasids); } +void dev_iommu_priv_set(struct device *dev, void *priv) +{ + /* FSL_PAMU does something weird */ + if (!IS_ENABLED(CONFIG_FSL_PAMU)) + lockdep_assert_held(&iommu_probe_device_lock); + dev->iommu->priv = priv; +} +EXPORT_SYMBOL_GPL(dev_iommu_priv_set); + /* * Init the dev->iommu and dev->iommu_group in the struct device and get the * driver probed. Take ownership of fwspec, it always freed on error diff --git a/drivers/iommu/omap-iommu.c b/drivers/iommu/omap-iommu.c index c66b070841dd41..c9528065a59afa 100644 --- a/drivers/iommu/omap-iommu.c +++ b/drivers/iommu/omap-iommu.c @@ -1719,7 +1719,6 @@ static void omap_iommu_release_device(struct device *dev) if (!dev->of_node || !arch_data) return; - dev_iommu_priv_set(dev, NULL); kfree(arch_data); } diff --git a/include/linux/iommu.h b/include/linux/iommu.h index 2fac54a942af54..de52217ee4f4c0 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -722,10 +722,7 @@ static inline void *dev_iommu_priv_get(struct device *dev) return NULL; } -static inline void dev_iommu_priv_set(struct device *dev, void *priv) -{ - dev->iommu->priv = priv; -} +void dev_iommu_priv_set(struct device *dev, void *priv); int iommu_probe_device_fwspec(struct device *dev, struct iommu_fwspec *fwspec); static inline int iommu_probe_device(struct device *dev)
A perfect driver would only call dev_iommu_priv_set() from its probe callback. We've made it functionally correct to call it from the of_xlate by adding a lock around that call. lockdep assert that iommu_probe_device_lock is held to discourage misuse. Exclude PPC kernels with CONFIG_FSL_PAMU turned on because FSL_PAMU uses a global static for its priv and abuses priv for its domain. Remove the pointless stores of NULL, all these are on paths where the core code will free dev->iommu after the op returns. Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> --- drivers/iommu/amd/iommu.c | 2 -- drivers/iommu/apple-dart.c | 1 - drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 1 - drivers/iommu/arm/arm-smmu/arm-smmu.c | 1 - drivers/iommu/intel/iommu.c | 2 -- drivers/iommu/iommu.c | 9 +++++++++ drivers/iommu/omap-iommu.c | 1 - include/linux/iommu.h | 5 +---- 8 files changed, 10 insertions(+), 12 deletions(-)