From: Robin Murphy <robin.murphy@arm.com> To: joro@8bytes.org Cc: will@kernel.org, iommu@lists.linux.dev, linux-arm-kernel@lists.infradead.org, baolu.lu@linux.intel.com, suravee.suthikulpanit@amd.com, vasant.hegde@amd.com, mjrosato@linux.ibm.com, gerald.schaefer@linux.ibm.com, schnelle@linux.ibm.com, linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v3 01/15] iommu/vt-d: Handle race between registration and device probe Date: Tue, 5 Jul 2022 18:08:24 +0100 [thread overview] Message-ID: <894db0ccae854b35c73814485569b634237b5538.1657034828.git.robin.murphy@arm.com> (raw) In-Reply-To: <cover.1657034827.git.robin.murphy@arm.com> 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, so I'm leaving it here for someone with more confidence to tackle a larger rework of the locking. Signed-off-by: Robin Murphy <robin.murphy@arm.com> --- v3: New drivers/iommu/intel/iommu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c index 44016594831d..3e02c08802a0 100644 --- a/drivers/iommu/intel/iommu.c +++ b/drivers/iommu/intel/iommu.c @@ -4600,7 +4600,7 @@ 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); -- 2.36.1.dirty
WARNING: multiple messages have this Message-ID (diff)
From: Robin Murphy <robin.murphy@arm.com> To: joro@8bytes.org Cc: will@kernel.org, iommu@lists.linux.dev, linux-arm-kernel@lists.infradead.org, baolu.lu@linux.intel.com, suravee.suthikulpanit@amd.com, vasant.hegde@amd.com, mjrosato@linux.ibm.com, gerald.schaefer@linux.ibm.com, schnelle@linux.ibm.com, linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v3 01/15] iommu/vt-d: Handle race between registration and device probe Date: Tue, 5 Jul 2022 18:08:24 +0100 [thread overview] Message-ID: <894db0ccae854b35c73814485569b634237b5538.1657034828.git.robin.murphy@arm.com> (raw) In-Reply-To: <cover.1657034827.git.robin.murphy@arm.com> 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, so I'm leaving it here for someone with more confidence to tackle a larger rework of the locking. Signed-off-by: Robin Murphy <robin.murphy@arm.com> --- v3: New drivers/iommu/intel/iommu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c index 44016594831d..3e02c08802a0 100644 --- a/drivers/iommu/intel/iommu.c +++ b/drivers/iommu/intel/iommu.c @@ -4600,7 +4600,7 @@ 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); -- 2.36.1.dirty _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2022-07-05 17:08 UTC|newest] Thread overview: 88+ messages / expand[flat|nested] mbox.gz Atom feed top 2022-07-05 17:08 [PATCH v3 00/15] iommu: Retire bus_set_iommu() Robin Murphy 2022-07-05 17:08 ` Robin Murphy 2022-07-05 17:08 ` Robin Murphy [this message] 2022-07-05 17:08 ` [PATCH v3 01/15] iommu/vt-d: Handle race between registration and device probe Robin Murphy 2022-07-06 1:39 ` Baolu Lu 2022-07-06 1:39 ` Baolu Lu 2022-07-07 6:51 ` Tian, Kevin 2022-07-07 6:51 ` Tian, Kevin 2022-07-08 7:52 ` Baolu Lu 2022-07-08 7:52 ` Baolu Lu 2022-07-15 12:37 ` Robin Murphy 2022-07-15 12:37 ` Robin Murphy 2022-07-19 0:06 ` Lu Baolu 2022-07-19 0:06 ` Lu Baolu 2022-07-05 17:08 ` [PATCH v3 02/15] iommu/amd: " Robin Murphy 2022-07-05 17:08 ` Robin Murphy 2022-07-05 17:08 ` [PATCH v3 03/15] iommu: Always register bus notifiers Robin Murphy 2022-07-05 17:08 ` Robin Murphy 2022-07-06 1:53 ` Baolu Lu 2022-07-06 1:53 ` Baolu Lu 2022-07-06 13:43 ` Robin Murphy 2022-07-06 13:43 ` Robin Murphy 2022-07-07 0:20 ` Baolu Lu 2022-07-07 0:20 ` Baolu Lu 2022-07-07 6:34 ` Tian, Kevin 2022-07-07 6:34 ` Tian, Kevin 2022-07-07 9:38 ` Robin Murphy 2022-07-07 9:38 ` Robin Murphy 2022-07-07 6:31 ` Tian, Kevin 2022-07-07 6:31 ` Tian, Kevin 2022-07-07 9:58 ` Robin Murphy 2022-07-07 9:58 ` Robin Murphy 2022-07-08 5:50 ` Tian, Kevin 2022-07-08 5:50 ` Tian, Kevin 2022-07-05 17:08 ` [PATCH v3 04/15] iommu: Move bus setup to IOMMU device registration Robin Murphy 2022-07-05 17:08 ` Robin Murphy 2022-07-06 2:35 ` Baolu Lu 2022-07-06 2:35 ` Baolu Lu 2022-07-06 14:37 ` Robin Murphy 2022-07-06 14:37 ` Robin Murphy 2022-07-07 1:19 ` Baolu Lu 2022-07-07 1:19 ` Baolu Lu 2022-07-07 6:51 ` Tian, Kevin 2022-07-07 6:51 ` Tian, Kevin 2022-07-07 10:58 ` Robin Murphy 2022-07-07 10:58 ` Robin Murphy 2022-07-08 5:52 ` Tian, Kevin 2022-07-08 5:52 ` Tian, Kevin 2022-07-05 17:08 ` [PATCH v3 05/15] iommu/amd: Clean up bus_set_iommu() Robin Murphy 2022-07-05 17:08 ` Robin Murphy 2022-07-05 17:08 ` [PATCH v3 06/15] iommu/arm-smmu: " Robin Murphy 2022-07-05 17:08 ` Robin Murphy 2022-07-05 17:08 ` [PATCH v3 07/15] iommu/arm-smmu-v3: " Robin Murphy 2022-07-05 17:08 ` Robin Murphy 2022-07-05 17:08 ` [PATCH v3 08/15] iommu/dart: " Robin Murphy 2022-07-05 17:08 ` Robin Murphy 2022-07-05 17:08 ` [PATCH v3 09/15] iommu/exynos: " Robin Murphy 2022-07-05 17:08 ` Robin Murphy 2022-07-05 17:08 ` [PATCH v3 10/15] iommu/ipmmu-vmsa: " Robin Murphy 2022-07-05 17:08 ` Robin Murphy 2022-07-05 17:08 ` [PATCH v3 11/15] iommu/mtk: " Robin Murphy 2022-07-05 17:08 ` Robin Murphy 2022-07-05 17:08 ` [PATCH v3 12/15] iommu/omap: " Robin Murphy 2022-07-05 17:08 ` Robin Murphy 2022-07-05 17:08 ` [PATCH v3 13/15] iommu/tegra-smmu: " Robin Murphy 2022-07-05 17:08 ` Robin Murphy 2022-07-05 17:08 ` [PATCH v3 14/15] iommu/virtio: " Robin Murphy 2022-07-05 17:08 ` Robin Murphy 2022-07-05 17:08 ` [PATCH v3 15/15] iommu: " Robin Murphy 2022-07-05 17:08 ` Robin Murphy 2022-07-07 7:45 ` Tian, Kevin 2022-07-07 7:45 ` Tian, Kevin 2022-07-07 12:49 ` Matthew Rosato 2022-07-07 12:49 ` Matthew Rosato 2022-07-07 12:54 ` Matthew Rosato 2022-07-07 12:54 ` Matthew Rosato 2022-07-07 14:58 ` Robin Murphy 2022-07-07 14:58 ` Robin Murphy 2022-07-07 16:42 ` Matthew Rosato 2022-07-07 16:42 ` Matthew Rosato 2022-07-08 8:14 ` [PATCH] iommu/s390: fail probe for non-pci device Niklas Schnelle 2022-07-08 8:14 ` Niklas Schnelle 2022-07-08 8:17 ` [PATCH v3 00/15] iommu: Retire bus_set_iommu() Niklas Schnelle 2022-07-08 8:17 ` Niklas Schnelle 2022-07-15 13:12 ` Robin Murphy 2022-07-15 13:12 ` Robin Murphy 2022-07-21 7:17 ` Tian, Kevin 2022-07-21 7:17 ` Tian, Kevin
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