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| author | Robin Murphy <robin.murphy@arm.com> | 2022-08-15 17:20:02 +0100 |
|---|---|---|
| committer | Joerg Roedel <jroedel@suse.de> | 2022-09-07 14:25:01 +0200 |
| commit | c919739ce4721ecf7b96b99253b032df30fcf19b (patch) | |
| tree | 15e18eb7ab4559eed9c5cb8941d43c9c0cec46fb /drivers/iommu | |
| parent | ca25ec247aadbff98083e92c5e79c198a16cd2db (diff) | |
| download | linux-c919739ce4721ecf7b96b99253b032df30fcf19b.tar.gz linux-c919739ce4721ecf7b96b99253b032df30fcf19b.tar.bz2 linux-c919739ce4721ecf7b96b99253b032df30fcf19b.zip | |
iommu/vt-d: Handle race between registration and device probe
Currently we rely on registering all our instances before initially
allowing any .probe_device calls via bus_set_iommu(). In preparation for
phasing out the latter, make sure we won't inadvertently return success
for a device associated with a known but not yet registered instance,
otherwise we'll run straight into iommu_group_get_for_dev() trying to
use NULL ops.
That also highlights an issue with intel_iommu_get_resv_regions() taking
dmar_global_lock from within a section where intel_iommu_init() already
holds it, which already exists via probe_acpi_namespace_devices() when
an ANDD device is probed, but gets more obvious with the upcoming change
to iommu_device_register(). Since they are both read locks it manages
not to deadlock in practice, and a more in-depth rework of this locking
is underway, so no attempt is made to address it here.
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/579f2692291bcbfc3ac64f7456fcff0d629af131.1660572783.git.robin.murphy@arm.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Diffstat (limited to 'drivers/iommu')
| -rw-r--r-- | drivers/iommu/intel/iommu.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c index da63b358ef4a..5d3c220a0308 100644 --- a/drivers/iommu/intel/iommu.c +++ b/drivers/iommu/intel/iommu.c @@ -4449,7 +4449,7 @@ static struct iommu_device *intel_iommu_probe_device(struct device *dev) u8 bus, devfn; iommu = device_to_iommu(dev, &bus, &devfn); - if (!iommu) + if (!iommu || !iommu->iommu.ops) return ERR_PTR(-ENODEV); info = kzalloc(sizeof(*info), GFP_KERNEL); |