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| author | Will Deacon <will@kernel.org> | 2019-12-19 12:03:41 +0000 |
|---|---|---|
| committer | Joerg Roedel <jroedel@suse.de> | 2019-12-23 14:06:05 +0100 |
| commit | 25f003de987aed630db265ceae9cd978537a3f80 (patch) | |
| tree | 6a53d13ae038b397f968766a1a5c7fa9b1b5fc71 /drivers/iommu/iommu.c | |
| parent | 1a373a78b8e2fae1d61dd9c5ed22472045d83d24 (diff) | |
| download | lwn-25f003de987aed630db265ceae9cd978537a3f80.tar.gz lwn-25f003de987aed630db265ceae9cd978537a3f80.zip | |
drivers/iommu: Take a ref to the IOMMU driver prior to ->add_device()
To avoid accidental removal of an active IOMMU driver module, take a
reference to the driver module in 'iommu_probe_device()' immediately
prior to invoking the '->add_device()' callback and hold it until the
after the device has been removed by '->remove_device()'.
Suggested-by: Joerg Roedel <joro@8bytes.org>
Signed-off-by: Will Deacon <will@kernel.org>
Tested-by: John Garry <john.garry@huawei.com> # smmu v3
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Diffstat (limited to 'drivers/iommu/iommu.c')
| -rw-r--r-- | drivers/iommu/iommu.c | 19 |
1 files changed, 17 insertions, 2 deletions
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 3abe19ecbcd1..32ceda1d5031 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -22,6 +22,7 @@ #include <linux/bitops.h> #include <linux/property.h> #include <linux/fsl/mc.h> +#include <linux/module.h> #include <trace/events/iommu.h> static struct kset *iommu_group_kset; @@ -185,10 +186,21 @@ int iommu_probe_device(struct device *dev) if (!iommu_get_dev_param(dev)) return -ENOMEM; + if (!try_module_get(ops->owner)) { + ret = -EINVAL; + goto err_free_dev_param; + } + ret = ops->add_device(dev); if (ret) - iommu_free_dev_param(dev); + goto err_module_put; + + return 0; +err_module_put: + module_put(ops->owner); +err_free_dev_param: + iommu_free_dev_param(dev); return ret; } @@ -199,7 +211,10 @@ void iommu_release_device(struct device *dev) if (dev->iommu_group) ops->remove_device(dev); - iommu_free_dev_param(dev); + if (dev->iommu_param) { + module_put(ops->owner); + iommu_free_dev_param(dev); + } } static struct iommu_domain *__iommu_domain_alloc(struct bus_type *bus, |