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Message-Id: <20240223051302.177596-3-baolu.lu@linux.intel.com>
Date: Fri, 23 Feb 2024 13:13:02 +0800
From: Lu Baolu <baolu.lu@...ux.intel.com>
To: Joerg Roedel <joro@...tes.org>,
Will Deacon <will@...nel.org>,
Robin Murphy <robin.murphy@....com>,
Jason Gunthorpe <jgg@...pe.ca>,
Kevin Tian <kevin.tian@...el.com>,
Eric Badger <ebadger@...estorage.com>
Cc: iommu@...ts.linux.dev,
linux-kernel@...r.kernel.org,
Lu Baolu <baolu.lu@...ux.intel.com>
Subject: [PATCH 2/2] iommu/vt-d: Fix NULL domain on device release
In the kdump kernel, the IOMMU operates in deferred_attach mode. In this
mode, info->domain may not yet be assigned by the time the release_device
function is called. It leads to the following crash in the crash kernel:
BUG: kernel NULL pointer dereference, address: 000000000000003c
...
RIP: 0010:do_raw_spin_lock+0xa/0xa0
...
_raw_spin_lock_irqsave+0x1b/0x30
intel_iommu_release_device+0x96/0x170
iommu_deinit_device+0x39/0xf0
__iommu_group_remove_device+0xa0/0xd0
iommu_bus_notifier+0x55/0xb0
notifier_call_chain+0x5a/0xd0
blocking_notifier_call_chain+0x41/0x60
bus_notify+0x34/0x50
device_del+0x269/0x3d0
pci_remove_bus_device+0x77/0x100
p2sb_bar+0xae/0x1d0
...
i801_probe+0x423/0x740
Use the release_domain mechanism to fix it.
Fixes: 586081d3f6b1 ("iommu/vt-d: Remove DEFER_DEVICE_DOMAIN_INFO")
Reported-by: Eric Badger <ebadger@...estorage.com>
Closes: https://lore.kernel.org/r/20240113181713.1817855-1-ebadger@purestorage.com
Signed-off-by: Lu Baolu <baolu.lu@...ux.intel.com>
---
drivers/iommu/intel/iommu.c | 26 +-------------------------
1 file changed, 1 insertion(+), 25 deletions(-)
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 61bb35046ea4..2c04ea90d22f 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -3798,30 +3798,6 @@ static void domain_context_clear(struct device_domain_info *info)
&domain_context_clear_one_cb, info);
}
-static void dmar_remove_one_dev_info(struct device *dev)
-{
- struct device_domain_info *info = dev_iommu_priv_get(dev);
- struct dmar_domain *domain = info->domain;
- struct intel_iommu *iommu = info->iommu;
- unsigned long flags;
-
- if (!dev_is_real_dma_subdevice(info->dev)) {
- if (dev_is_pci(info->dev) && sm_supported(iommu))
- intel_pasid_tear_down_entry(iommu, info->dev,
- IOMMU_NO_PASID, false);
-
- iommu_disable_pci_caps(info);
- domain_context_clear(info);
- }
-
- spin_lock_irqsave(&domain->lock, flags);
- list_del(&info->link);
- spin_unlock_irqrestore(&domain->lock, flags);
-
- domain_detach_iommu(domain, iommu);
- info->domain = NULL;
-}
-
/*
* Clear the page table pointer in context or pasid table entries so that
* all DMA requests without PASID from the device are blocked. If the page
@@ -4348,7 +4324,6 @@ static void intel_iommu_release_device(struct device *dev)
{
struct device_domain_info *info = dev_iommu_priv_get(dev);
- dmar_remove_one_dev_info(dev);
intel_pasid_free_table(dev);
intel_iommu_debugfs_remove_dev(info);
kfree(info);
@@ -4839,6 +4814,7 @@ static const struct iommu_dirty_ops intel_dirty_ops = {
const struct iommu_ops intel_iommu_ops = {
.blocked_domain = &blocking_domain,
+ .release_domain = &blocking_domain,
.capable = intel_iommu_capable,
.hw_info = intel_iommu_hw_info,
.domain_alloc = intel_iommu_domain_alloc,
--
2.34.1
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