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author | Robin Murphy <robin.murphy@arm.com> | 2017-01-16 13:58:07 +0100 |
---|---|---|
committer | Joerg Roedel <jroedel@suse.de> | 2017-01-17 16:49:24 +0100 |
commit | 797a8b4d768c58caac58ee3e8cb36a164d1b7751 (patch) | |
tree | 6f7bdf319d1bf50bbfef970167755d464eabb499 /drivers/iommu | |
parent | iommu/iova: Use rb_entry() (diff) | |
download | linux-797a8b4d768c58caac58ee3e8cb36a164d1b7751.tar.xz linux-797a8b4d768c58caac58ee3e8cb36a164d1b7751.zip |
iommu: Handle default domain attach failure
We wouldn't normally expect ops->attach_dev() to fail, but on IOMMUs
with limited hardware resources, or generally misconfigured systems,
it is certainly possible. We report failure correctly from the external
iommu_attach_device() interface, but do not do so in iommu_group_add()
when attaching to the default domain. The result of failure there is
that the device, group and domain all get left in a broken,
part-configured state which leads to weird errors and misbehaviour down
the line when IOMMU API calls sort-of-but-don't-quite work.
Check the return value of __iommu_attach_device() on the default domain,
and refactor the error handling paths to cope with its failure and clean
up correctly in such cases.
Fixes: e39cb8a3aa98 ("iommu: Make sure a device is always attached to a domain")
Reported-by: Punit Agrawal <punit.agrawal@arm.com>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Diffstat (limited to 'drivers/iommu')
-rw-r--r-- | drivers/iommu/iommu.c | 37 |
1 files changed, 24 insertions, 13 deletions
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index dbe7f653bb7c..aed906a3e3db 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -383,36 +383,30 @@ int iommu_group_add_device(struct iommu_group *group, struct device *dev) device->dev = dev; ret = sysfs_create_link(&dev->kobj, &group->kobj, "iommu_group"); - if (ret) { - kfree(device); - return ret; - } + if (ret) + goto err_free_device; device->name = kasprintf(GFP_KERNEL, "%s", kobject_name(&dev->kobj)); rename: if (!device->name) { - sysfs_remove_link(&dev->kobj, "iommu_group"); - kfree(device); - return -ENOMEM; + ret = -ENOMEM; + goto err_remove_link; } ret = sysfs_create_link_nowarn(group->devices_kobj, &dev->kobj, device->name); if (ret) { - kfree(device->name); if (ret == -EEXIST && i >= 0) { /* * Account for the slim chance of collision * and append an instance to the name. */ + kfree(device->name); device->name = kasprintf(GFP_KERNEL, "%s.%d", kobject_name(&dev->kobj), i++); goto rename; } - - sysfs_remove_link(&dev->kobj, "iommu_group"); - kfree(device); - return ret; + goto err_free_name; } kobject_get(group->devices_kobj); @@ -424,8 +418,10 @@ rename: mutex_lock(&group->mutex); list_add_tail(&device->list, &group->devices); if (group->domain) - __iommu_attach_device(group->domain, dev); + ret = __iommu_attach_device(group->domain, dev); mutex_unlock(&group->mutex); + if (ret) + goto err_put_group; /* Notify any listeners about change to group. */ blocking_notifier_call_chain(&group->notifier, @@ -436,6 +432,21 @@ rename: pr_info("Adding device %s to group %d\n", dev_name(dev), group->id); return 0; + +err_put_group: + mutex_lock(&group->mutex); + list_del(&device->list); + mutex_unlock(&group->mutex); + dev->iommu_group = NULL; + kobject_put(group->devices_kobj); +err_free_name: + kfree(device->name); +err_remove_link: + sysfs_remove_link(&dev->kobj, "iommu_group"); +err_free_device: + kfree(device); + pr_err("Failed to add device %s to group %d: %d\n", dev_name(dev), group->id, ret); + return ret; } EXPORT_SYMBOL_GPL(iommu_group_add_device); |