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authorLu Baolu <baolu.lu@linux.intel.com>2020-09-27 14:24:28 +0800
committerJoerg Roedel <jroedel@suse.de>2020-10-01 14:54:17 +0200
commit1a3f2fd7fc4e8f24510830e265de2ffb8e3300d2 (patch)
tree1f23f0361f6d748e89e462440dfdf4c968522139 /drivers/iommu
parent0bbe4ced53e36786eafc2ecbf9a1761f55b4a82e (diff)
downloadlinux-1a3f2fd7fc4e8f24510830e265de2ffb8e3300d2.tar.bz2
iommu/vt-d: Fix lockdep splat in iommu_flush_dev_iotlb()
Lock(&iommu->lock) without disabling irq causes lockdep warnings. [ 12.703950] ======================================================== [ 12.703962] WARNING: possible irq lock inversion dependency detected [ 12.703975] 5.9.0-rc6+ #659 Not tainted [ 12.703983] -------------------------------------------------------- [ 12.703995] systemd-udevd/284 just changed the state of lock: [ 12.704007] ffffffffbd6ff4d8 (device_domain_lock){..-.}-{2:2}, at: iommu_flush_dev_iotlb.part.57+0x2e/0x90 [ 12.704031] but this lock took another, SOFTIRQ-unsafe lock in the past: [ 12.704043] (&iommu->lock){+.+.}-{2:2} [ 12.704045] and interrupts could create inverse lock ordering between them. [ 12.704073] other info that might help us debug this: [ 12.704085] Possible interrupt unsafe locking scenario: [ 12.704097] CPU0 CPU1 [ 12.704106] ---- ---- [ 12.704115] lock(&iommu->lock); [ 12.704123] local_irq_disable(); [ 12.704134] lock(device_domain_lock); [ 12.704146] lock(&iommu->lock); [ 12.704158] <Interrupt> [ 12.704164] lock(device_domain_lock); [ 12.704174] *** DEADLOCK *** Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> Link: https://lore.kernel.org/r/20200927062428.13713-1-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel <jroedel@suse.de>
Diffstat (limited to 'drivers/iommu')
-rw-r--r--drivers/iommu/intel/iommu.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 87b17bac04c2..2239c211178b 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -2664,7 +2664,7 @@ static struct dmar_domain *dmar_insert_one_dev_info(struct intel_iommu *iommu,
}
/* Setup the PASID entry for requests without PASID: */
- spin_lock(&iommu->lock);
+ spin_lock_irqsave(&iommu->lock, flags);
if (hw_pass_through && domain_type_is_si(domain))
ret = intel_pasid_setup_pass_through(iommu, domain,
dev, PASID_RID2PASID);
@@ -2674,7 +2674,7 @@ static struct dmar_domain *dmar_insert_one_dev_info(struct intel_iommu *iommu,
else
ret = intel_pasid_setup_second_level(iommu, domain,
dev, PASID_RID2PASID);
- spin_unlock(&iommu->lock);
+ spin_unlock_irqrestore(&iommu->lock, flags);
if (ret) {
dev_err(dev, "Setup RID2PASID failed\n");
dmar_remove_one_dev_info(dev);