WSL2-Linux-Kernel/drivers/iommu/intel
Lu Baolu 1a3f2fd7fc 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>
2020-10-01 14:54:17 +02:00
..
Kconfig IOMMU Updates for Linux v5.9 2020-08-11 14:13:24 -07:00
Makefile iommu/vt-d: Move Kconfig and Makefile bits down into intel directory 2020-07-29 14:14:55 +02:00
debugfs.c iommu/vt-d: Rename intel-pasid.h to pasid.h 2020-07-24 10:51:21 +02:00
dmar.c iommu/vt-d: Skip TE disabling on quirky gfx dedicated iommu 2020-07-24 14:33:39 +02:00
iommu.c iommu/vt-d: Fix lockdep splat in iommu_flush_dev_iotlb() 2020-10-01 14:54:17 +02:00
irq_remapping.c iommu/vt-d: Serialize IOMMU GCMD register modifications 2020-09-04 11:39:21 +02:00
pasid.c iommu/vt-d: Rename intel-pasid.h to pasid.h 2020-07-24 10:51:21 +02:00
pasid.h iommu/vt-d: Rename intel-pasid.h to pasid.h 2020-07-24 10:51:21 +02:00
svm.c Merge branch 'akpm' (patches from Andrew) 2020-08-12 11:24:12 -07:00
trace.c