<feed xmlns='http://www.w3.org/2005/Atom'>
<title>BMC/Intel-BMC/linux.git/drivers/iommu, branch dev-5.2</title>
<subtitle>Intel OpenBMC Linux kernel source tree (mirror)</subtitle>
<id>https://git.radix-linux.su/BMC/Intel-BMC/linux.git/atom?h=dev-5.2</id>
<link rel='self' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/atom?h=dev-5.2'/>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/'/>
<updated>2019-09-06T08:23:18+00:00</updated>
<entry>
<title>iommu/dma: Handle SG length overflow better</title>
<updated>2019-09-06T08:23:18+00:00</updated>
<author>
<name>Robin Murphy</name>
<email>robin.murphy@arm.com</email>
</author>
<published>2019-07-29T16:46:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=583c8d3118e00e32b1fe64dc6c442e8f241f9198'/>
<id>urn:sha1:583c8d3118e00e32b1fe64dc6c442e8f241f9198</id>
<content type='text'>
[ Upstream commit ab2cbeb0ed301a9f0460078e91b09f39958212ef ]

Since scatterlist dimensions are all unsigned ints, in the relatively
rare cases where a device's max_segment_size is set to UINT_MAX, then
the "cur_len + s_length &lt;= max_len" check in __finalise_sg() will always
return true. As a result, the corner case of such a device mapping an
excessively large scatterlist which is mergeable to or beyond a total
length of 4GB can lead to overflow and a bogus truncated dma_length in
the resulting segment.

As we already assume that any single segment must be no longer than
max_len to begin with, this can easily be addressed by reshuffling the
comparison.

Fixes: 809eac54cdd6 ("iommu/dma: Implement scatterlist segment merging")
Reported-by: Nicolin Chen &lt;nicoleotsuka@gmail.com&gt;
Tested-by: Nicolin Chen &lt;nicoleotsuka@gmail.com&gt;
Signed-off-by: Robin Murphy &lt;robin.murphy@arm.com&gt;
Signed-off-by: Joerg Roedel &lt;jroedel@suse.de&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>iommu/vt-d: Check if domain-&gt;pgd was allocated</title>
<updated>2019-08-16T08:11:03+00:00</updated>
<author>
<name>Dmitry Safonov</name>
<email>dima@arista.com</email>
</author>
<published>2019-07-16T21:38:06+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=69dd8b5ebe8edd0330691922b04d098f55a15a7f'/>
<id>urn:sha1:69dd8b5ebe8edd0330691922b04d098f55a15a7f</id>
<content type='text'>
[ Upstream commit 3ee9eca760e7d0b68c55813243de66bbb499dc3b ]

There is a couple of places where on domain_init() failure domain_exit()
is called. While currently domain_init() can fail only if
alloc_pgtable_page() has failed.

Make domain_exit() check if domain-&gt;pgd present, before calling
domain_unmap(), as it theoretically should crash on clearing pte entries
in dma_pte_clear_level().

Cc: David Woodhouse &lt;dwmw2@infradead.org&gt;
Cc: Joerg Roedel &lt;joro@8bytes.org&gt;
Cc: Lu Baolu &lt;baolu.lu@linux.intel.com&gt;
Cc: iommu@lists.linux-foundation.org
Signed-off-by: Dmitry Safonov &lt;dima@arista.com&gt;
Reviewed-by: Lu Baolu &lt;baolu.lu@linux.intel.com&gt;
Signed-off-by: Joerg Roedel &lt;jroedel@suse.de&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>iommu/iova: Remove stale cached32_node</title>
<updated>2019-07-31T05:25:02+00:00</updated>
<author>
<name>Chris Wilson</name>
<email>chris@chris-wilson.co.uk</email>
</author>
<published>2019-07-20T18:08:48+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=0ce35762bad71d077b7a582338a4e40ec0d3fc04'/>
<id>urn:sha1:0ce35762bad71d077b7a582338a4e40ec0d3fc04</id>
<content type='text'>
commit 9eed17d37c77171cf5ffb95c4257f87df3cd4c8f upstream.

Since the cached32_node is allowed to be advanced above dma_32bit_pfn
(to provide a shortcut into the limited range), we need to be careful to
remove the to be freed node if it is the cached32_node.

[   48.477773] BUG: KASAN: use-after-free in __cached_rbnode_delete_update+0x68/0x110
[   48.477812] Read of size 8 at addr ffff88870fc19020 by task kworker/u8:1/37
[   48.477843]
[   48.477879] CPU: 1 PID: 37 Comm: kworker/u8:1 Tainted: G     U            5.2.0+ #735
[   48.477915] Hardware name: Intel Corporation NUC7i5BNK/NUC7i5BNB, BIOS BNKBL357.86A.0052.2017.0918.1346 09/18/2017
[   48.478047] Workqueue: i915 __i915_gem_free_work [i915]
[   48.478075] Call Trace:
[   48.478111]  dump_stack+0x5b/0x90
[   48.478137]  print_address_description+0x67/0x237
[   48.478178]  ? __cached_rbnode_delete_update+0x68/0x110
[   48.478212]  __kasan_report.cold.3+0x1c/0x38
[   48.478240]  ? __cached_rbnode_delete_update+0x68/0x110
[   48.478280]  ? __cached_rbnode_delete_update+0x68/0x110
[   48.478308]  __cached_rbnode_delete_update+0x68/0x110
[   48.478344]  private_free_iova+0x2b/0x60
[   48.478378]  iova_magazine_free_pfns+0x46/0xa0
[   48.478403]  free_iova_fast+0x277/0x340
[   48.478443]  fq_ring_free+0x15a/0x1a0
[   48.478473]  queue_iova+0x19c/0x1f0
[   48.478597]  cleanup_page_dma.isra.64+0x62/0xb0 [i915]
[   48.478712]  __gen8_ppgtt_cleanup+0x63/0x80 [i915]
[   48.478826]  __gen8_ppgtt_cleanup+0x42/0x80 [i915]
[   48.478940]  __gen8_ppgtt_clear+0x433/0x4b0 [i915]
[   48.479053]  __gen8_ppgtt_clear+0x462/0x4b0 [i915]
[   48.479081]  ? __sg_free_table+0x9e/0xf0
[   48.479116]  ? kfree+0x7f/0x150
[   48.479234]  i915_vma_unbind+0x1e2/0x240 [i915]
[   48.479352]  i915_vma_destroy+0x3a/0x280 [i915]
[   48.479465]  __i915_gem_free_objects+0xf0/0x2d0 [i915]
[   48.479579]  __i915_gem_free_work+0x41/0xa0 [i915]
[   48.479607]  process_one_work+0x495/0x710
[   48.479642]  worker_thread+0x4c7/0x6f0
[   48.479687]  ? process_one_work+0x710/0x710
[   48.479724]  kthread+0x1b2/0x1d0
[   48.479774]  ? kthread_create_worker_on_cpu+0xa0/0xa0
[   48.479820]  ret_from_fork+0x1f/0x30
[   48.479864]
[   48.479907] Allocated by task 631:
[   48.479944]  save_stack+0x19/0x80
[   48.479994]  __kasan_kmalloc.constprop.6+0xc1/0xd0
[   48.480038]  kmem_cache_alloc+0x91/0xf0
[   48.480082]  alloc_iova+0x2b/0x1e0
[   48.480125]  alloc_iova_fast+0x58/0x376
[   48.480166]  intel_alloc_iova+0x90/0xc0
[   48.480214]  intel_map_sg+0xde/0x1f0
[   48.480343]  i915_gem_gtt_prepare_pages+0xb8/0x170 [i915]
[   48.480465]  huge_get_pages+0x232/0x2b0 [i915]
[   48.480590]  ____i915_gem_object_get_pages+0x40/0xb0 [i915]
[   48.480712]  __i915_gem_object_get_pages+0x90/0xa0 [i915]
[   48.480834]  i915_gem_object_prepare_write+0x2d6/0x330 [i915]
[   48.480955]  create_test_object.isra.54+0x1a9/0x3e0 [i915]
[   48.481075]  igt_shared_ctx_exec+0x365/0x3c0 [i915]
[   48.481210]  __i915_subtests.cold.4+0x30/0x92 [i915]
[   48.481341]  __run_selftests.cold.3+0xa9/0x119 [i915]
[   48.481466]  i915_live_selftests+0x3c/0x70 [i915]
[   48.481583]  i915_pci_probe+0xe7/0x220 [i915]
[   48.481620]  pci_device_probe+0xe0/0x180
[   48.481665]  really_probe+0x163/0x4e0
[   48.481710]  device_driver_attach+0x85/0x90
[   48.481750]  __driver_attach+0xa5/0x180
[   48.481796]  bus_for_each_dev+0xda/0x130
[   48.481831]  bus_add_driver+0x205/0x2e0
[   48.481882]  driver_register+0xca/0x140
[   48.481927]  do_one_initcall+0x6c/0x1af
[   48.481970]  do_init_module+0x106/0x350
[   48.482010]  load_module+0x3d2c/0x3ea0
[   48.482058]  __do_sys_finit_module+0x110/0x180
[   48.482102]  do_syscall_64+0x62/0x1f0
[   48.482147]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[   48.482190]
[   48.482224] Freed by task 37:
[   48.482273]  save_stack+0x19/0x80
[   48.482318]  __kasan_slab_free+0x12e/0x180
[   48.482363]  kmem_cache_free+0x70/0x140
[   48.482406]  __free_iova+0x1d/0x30
[   48.482445]  fq_ring_free+0x15a/0x1a0
[   48.482490]  queue_iova+0x19c/0x1f0
[   48.482624]  cleanup_page_dma.isra.64+0x62/0xb0 [i915]
[   48.482749]  __gen8_ppgtt_cleanup+0x63/0x80 [i915]
[   48.482873]  __gen8_ppgtt_cleanup+0x42/0x80 [i915]
[   48.482999]  __gen8_ppgtt_clear+0x433/0x4b0 [i915]
[   48.483123]  __gen8_ppgtt_clear+0x462/0x4b0 [i915]
[   48.483250]  i915_vma_unbind+0x1e2/0x240 [i915]
[   48.483378]  i915_vma_destroy+0x3a/0x280 [i915]
[   48.483500]  __i915_gem_free_objects+0xf0/0x2d0 [i915]
[   48.483622]  __i915_gem_free_work+0x41/0xa0 [i915]
[   48.483659]  process_one_work+0x495/0x710
[   48.483704]  worker_thread+0x4c7/0x6f0
[   48.483748]  kthread+0x1b2/0x1d0
[   48.483787]  ret_from_fork+0x1f/0x30
[   48.483831]
[   48.483868] The buggy address belongs to the object at ffff88870fc19000
[   48.483868]  which belongs to the cache iommu_iova of size 40
[   48.483920] The buggy address is located 32 bytes inside of
[   48.483920]  40-byte region [ffff88870fc19000, ffff88870fc19028)
[   48.483964] The buggy address belongs to the page:
[   48.484006] page:ffffea001c3f0600 refcount:1 mapcount:0 mapping:ffff8888181a91c0 index:0x0 compound_mapcount: 0
[   48.484045] flags: 0x8000000000010200(slab|head)
[   48.484096] raw: 8000000000010200 ffffea001c421a08 ffffea001c447e88 ffff8888181a91c0
[   48.484141] raw: 0000000000000000 0000000000120012 00000001ffffffff 0000000000000000
[   48.484188] page dumped because: kasan: bad access detected
[   48.484230]
[   48.484265] Memory state around the buggy address:
[   48.484314]  ffff88870fc18f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[   48.484361]  ffff88870fc18f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[   48.484406] &gt;ffff88870fc19000: fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc
[   48.484451]                                ^
[   48.484494]  ffff88870fc19080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[   48.484530]  ffff88870fc19100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=108602
Fixes: e60aa7b53845 ("iommu/iova: Extend rbtree node caching")
Signed-off-by: Chris Wilson &lt;chris@chris-wilson.co.uk&gt;
Cc: Robin Murphy &lt;robin.murphy@arm.com&gt;
Cc: Joerg Roedel &lt;jroedel@suse.de&gt;
Cc: Joerg Roedel &lt;joro@8bytes.org&gt;
Cc: &lt;stable@vger.kernel.org&gt; # v4.15+
Reviewed-by: Robin Murphy &lt;robin.murphy@arm.com&gt;
Signed-off-by: Joerg Roedel &lt;jroedel@suse.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>iommu/vt-d: Don't queue_iova() if there is no flush queue</title>
<updated>2019-07-31T05:25:02+00:00</updated>
<author>
<name>Dmitry Safonov</name>
<email>dima@arista.com</email>
</author>
<published>2019-07-16T21:38:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=8498d00472bfe08a94625da502ebdbae129aad9e'/>
<id>urn:sha1:8498d00472bfe08a94625da502ebdbae129aad9e</id>
<content type='text'>
commit effa467870c7612012885df4e246bdb8ffd8e44c upstream.

Intel VT-d driver was reworked to use common deferred flushing
implementation. Previously there was one global per-cpu flush queue,
afterwards - one per domain.

Before deferring a flush, the queue should be allocated and initialized.

Currently only domains with IOMMU_DOMAIN_DMA type initialize their flush
queue. It's probably worth to init it for static or unmanaged domains
too, but it may be arguable - I'm leaving it to iommu folks.

Prevent queuing an iova flush if the domain doesn't have a queue.
The defensive check seems to be worth to keep even if queue would be
initialized for all kinds of domains. And is easy backportable.

On 4.19.43 stable kernel it has a user-visible effect: previously for
devices in si domain there were crashes, on sata devices:

 BUG: spinlock bad magic on CPU#6, swapper/0/1
  lock: 0xffff88844f582008, .magic: 00000000, .owner: &lt;none&gt;/-1, .owner_cpu: 0
 CPU: 6 PID: 1 Comm: swapper/0 Not tainted 4.19.43 #1
 Call Trace:
  &lt;IRQ&gt;
  dump_stack+0x61/0x7e
  spin_bug+0x9d/0xa3
  do_raw_spin_lock+0x22/0x8e
  _raw_spin_lock_irqsave+0x32/0x3a
  queue_iova+0x45/0x115
  intel_unmap+0x107/0x113
  intel_unmap_sg+0x6b/0x76
  __ata_qc_complete+0x7f/0x103
  ata_qc_complete+0x9b/0x26a
  ata_qc_complete_multiple+0xd0/0xe3
  ahci_handle_port_interrupt+0x3ee/0x48a
  ahci_handle_port_intr+0x73/0xa9
  ahci_single_level_irq_intr+0x40/0x60
  __handle_irq_event_percpu+0x7f/0x19a
  handle_irq_event_percpu+0x32/0x72
  handle_irq_event+0x38/0x56
  handle_edge_irq+0x102/0x121
  handle_irq+0x147/0x15c
  do_IRQ+0x66/0xf2
  common_interrupt+0xf/0xf
 RIP: 0010:__do_softirq+0x8c/0x2df

The same for usb devices that use ehci-pci:
 BUG: spinlock bad magic on CPU#0, swapper/0/1
  lock: 0xffff88844f402008, .magic: 00000000, .owner: &lt;none&gt;/-1, .owner_cpu: 0
 CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.19.43 #4
 Call Trace:
  &lt;IRQ&gt;
  dump_stack+0x61/0x7e
  spin_bug+0x9d/0xa3
  do_raw_spin_lock+0x22/0x8e
  _raw_spin_lock_irqsave+0x32/0x3a
  queue_iova+0x77/0x145
  intel_unmap+0x107/0x113
  intel_unmap_page+0xe/0x10
  usb_hcd_unmap_urb_setup_for_dma+0x53/0x9d
  usb_hcd_unmap_urb_for_dma+0x17/0x100
  unmap_urb_for_dma+0x22/0x24
  __usb_hcd_giveback_urb+0x51/0xc3
  usb_giveback_urb_bh+0x97/0xde
  tasklet_action_common.isra.4+0x5f/0xa1
  tasklet_action+0x2d/0x30
  __do_softirq+0x138/0x2df
  irq_exit+0x7d/0x8b
  smp_apic_timer_interrupt+0x10f/0x151
  apic_timer_interrupt+0xf/0x20
  &lt;/IRQ&gt;
 RIP: 0010:_raw_spin_unlock_irqrestore+0x17/0x39

Cc: David Woodhouse &lt;dwmw2@infradead.org&gt;
Cc: Joerg Roedel &lt;joro@8bytes.org&gt;
Cc: Lu Baolu &lt;baolu.lu@linux.intel.com&gt;
Cc: iommu@lists.linux-foundation.org
Cc: &lt;stable@vger.kernel.org&gt; # 4.14+
Fixes: 13cf01744608 ("iommu/vt-d: Make use of iova deferred flushing")
Signed-off-by: Dmitry Safonov &lt;dima@arista.com&gt;
Reviewed-by: Lu Baolu &lt;baolu.lu@linux.intel.com&gt;
Signed-off-by: Joerg Roedel &lt;jroedel@suse.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>iommu/arm-smmu-v3: Invalidate ATC when detaching a device</title>
<updated>2019-07-26T07:10:44+00:00</updated>
<author>
<name>Jean-Philippe Brucker</name>
<email>jean-philippe.brucker@arm.com</email>
</author>
<published>2019-07-03T11:19:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=0417b0fda7f992b61fd132fec64df4b90b21c494'/>
<id>urn:sha1:0417b0fda7f992b61fd132fec64df4b90b21c494</id>
<content type='text'>
[ Upstream commit 8dd8f005bdd45823fc153ef490239558caf6ff20 ]

We make the invalid assumption in arm_smmu_detach_dev() that the ATC is
clear after calling pci_disable_ats(). For one thing, only enabling the
PCIe ATS capability constitutes an implicit invalidation event, so the
comment was wrong. More importantly, the ATS capability isn't necessarily
disabled by pci_disable_ats() in a PF, if the associated VFs have ATS
enabled. Explicitly invalidate all ATC entries in arm_smmu_detach_dev().
The endpoint cannot form new ATC entries because STE.EATS is clear.

Fixes: 9ce27afc0830 ("iommu/arm-smmu-v3: Add support for PCI ATS")
Reported-by: Manoj Kumar &lt;Manoj.Kumar3@arm.com&gt;
Reported-by: Robin Murphy &lt;Robin.Murphy@arm.com&gt;
Signed-off-by: Jean-Philippe Brucker &lt;jean-philippe.brucker@arm.com&gt;
Acked-by: Will Deacon &lt;will@kernel.org&gt;
Signed-off-by: Joerg Roedel &lt;jroedel@suse.de&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>iommu: Fix a leak in iommu_insert_resv_region</title>
<updated>2019-07-26T07:10:24+00:00</updated>
<author>
<name>Eric Auger</name>
<email>eric.auger@redhat.com</email>
</author>
<published>2019-06-03T06:53:30+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=725fb018531f72dff4fc0a4a01e191451db1e538'/>
<id>urn:sha1:725fb018531f72dff4fc0a4a01e191451db1e538</id>
<content type='text'>
[ Upstream commit ad0834dedaa15c3a176f783c0373f836e44b4700 ]

In case we expand an existing region, we unlink
this latter and insert the larger one. In
that case we should free the original region after
the insertion. Also we can immediately return.

Fixes: 6c65fb318e8b ("iommu: iommu_get_group_resv_regions")

Signed-off-by: Eric Auger &lt;eric.auger@redhat.com&gt;
Signed-off-by: Joerg Roedel &lt;jroedel@suse.de&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>Merge tag 'iommu-fix-v5.2-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu</title>
<updated>2019-06-22T21:08:47+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2019-06-22T21:08:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=6698a71a1e360d89514aafcea15ccff837f59038'/>
<id>urn:sha1:6698a71a1e360d89514aafcea15ccff837f59038</id>
<content type='text'>
Pull iommu fix from Joerg Roedel:
 "Revert a commit from the previous pile of fixes which causes new
  lockdep splats. It is better to revert it for now and work on a better
  and more well tested fix"

* tag 'iommu-fix-v5.2-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu:
  Revert "iommu/vt-d: Fix lock inversion between iommu-&gt;lock and device_domain_lock"
</content>
</entry>
<entry>
<title>Revert "iommu/vt-d: Fix lock inversion between iommu-&gt;lock and device_domain_lock"</title>
<updated>2019-06-22T19:19:58+00:00</updated>
<author>
<name>Peter Xu</name>
<email>peterx@redhat.com</email>
</author>
<published>2019-06-21T02:32:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=0aafc8ae665f89b9031a914f80f5e58825b33021'/>
<id>urn:sha1:0aafc8ae665f89b9031a914f80f5e58825b33021</id>
<content type='text'>
This reverts commit 7560cc3ca7d9d11555f80c830544e463fcdb28b8.

With 5.2.0-rc5 I can easily trigger this with lockdep and iommu=pt:

    ======================================================
    WARNING: possible circular locking dependency detected
    5.2.0-rc5 #78 Not tainted
    ------------------------------------------------------
    swapper/0/1 is trying to acquire lock:
    00000000ea2b3beb (&amp;(&amp;iommu-&gt;lock)-&gt;rlock){+.+.}, at: domain_context_mapping_one+0xa5/0x4e0
    but task is already holding lock:
    00000000a681907b (device_domain_lock){....}, at: domain_context_mapping_one+0x8d/0x4e0
    which lock already depends on the new lock.
    the existing dependency chain (in reverse order) is:
    -&gt; #1 (device_domain_lock){....}:
           _raw_spin_lock_irqsave+0x3c/0x50
           dmar_insert_one_dev_info+0xbb/0x510
           domain_add_dev_info+0x50/0x90
           dev_prepare_static_identity_mapping+0x30/0x68
           intel_iommu_init+0xddd/0x1422
           pci_iommu_init+0x16/0x3f
           do_one_initcall+0x5d/0x2b4
           kernel_init_freeable+0x218/0x2c1
           kernel_init+0xa/0x100
           ret_from_fork+0x3a/0x50
    -&gt; #0 (&amp;(&amp;iommu-&gt;lock)-&gt;rlock){+.+.}:
           lock_acquire+0x9e/0x170
           _raw_spin_lock+0x25/0x30
           domain_context_mapping_one+0xa5/0x4e0
           pci_for_each_dma_alias+0x30/0x140
           dmar_insert_one_dev_info+0x3b2/0x510
           domain_add_dev_info+0x50/0x90
           dev_prepare_static_identity_mapping+0x30/0x68
           intel_iommu_init+0xddd/0x1422
           pci_iommu_init+0x16/0x3f
           do_one_initcall+0x5d/0x2b4
           kernel_init_freeable+0x218/0x2c1
           kernel_init+0xa/0x100
           ret_from_fork+0x3a/0x50

    other info that might help us debug this:
     Possible unsafe locking scenario:
           CPU0                    CPU1
           ----                    ----
      lock(device_domain_lock);
                                   lock(&amp;(&amp;iommu-&gt;lock)-&gt;rlock);
                                   lock(device_domain_lock);
      lock(&amp;(&amp;iommu-&gt;lock)-&gt;rlock);

     *** DEADLOCK ***
    2 locks held by swapper/0/1:
     #0: 00000000033eb13d (dmar_global_lock){++++}, at: intel_iommu_init+0x1e0/0x1422
     #1: 00000000a681907b (device_domain_lock){....}, at: domain_context_mapping_one+0x8d/0x4e0

    stack backtrace:
    CPU: 2 PID: 1 Comm: swapper/0 Not tainted 5.2.0-rc5 #78
    Hardware name: LENOVO 20KGS35G01/20KGS35G01, BIOS N23ET50W (1.25 ) 06/25/2018
    Call Trace:
     dump_stack+0x85/0xc0
     print_circular_bug.cold.57+0x15c/0x195
     __lock_acquire+0x152a/0x1710
     lock_acquire+0x9e/0x170
     ? domain_context_mapping_one+0xa5/0x4e0
     _raw_spin_lock+0x25/0x30
     ? domain_context_mapping_one+0xa5/0x4e0
     domain_context_mapping_one+0xa5/0x4e0
     ? domain_context_mapping_one+0x4e0/0x4e0
     pci_for_each_dma_alias+0x30/0x140
     dmar_insert_one_dev_info+0x3b2/0x510
     domain_add_dev_info+0x50/0x90
     dev_prepare_static_identity_mapping+0x30/0x68
     intel_iommu_init+0xddd/0x1422
     ? printk+0x58/0x6f
     ? lockdep_hardirqs_on+0xf0/0x180
     ? do_early_param+0x8e/0x8e
     ? e820__memblock_setup+0x63/0x63
     pci_iommu_init+0x16/0x3f
     do_one_initcall+0x5d/0x2b4
     ? do_early_param+0x8e/0x8e
     ? rcu_read_lock_sched_held+0x55/0x60
     ? do_early_param+0x8e/0x8e
     kernel_init_freeable+0x218/0x2c1
     ? rest_init+0x230/0x230
     kernel_init+0xa/0x100
     ret_from_fork+0x3a/0x50

domain_context_mapping_one() is taking device_domain_lock first then
iommu lock, while dmar_insert_one_dev_info() is doing the reverse.

That should be introduced by commit:

7560cc3ca7d9 ("iommu/vt-d: Fix lock inversion between iommu-&gt;lock and
              device_domain_lock", 2019-05-27)

So far I still cannot figure out how the previous deadlock was
triggered (I cannot find iommu lock taken before calling of
iommu_flush_dev_iotlb()), however I'm pretty sure that that change
should be incomplete at least because it does not fix all the places
so we're still taking the locks in different orders, while reverting
that commit is very clean to me so far that we should always take
device_domain_lock first then the iommu lock.

We can continue to try to find the real culprit mentioned in
7560cc3ca7d9, but for now I think we should revert it to fix current
breakage.

CC: Joerg Roedel &lt;joro@8bytes.org&gt;
CC: Lu Baolu &lt;baolu.lu@linux.intel.com&gt;
CC: dave.jiang@intel.com
Signed-off-by: Peter Xu &lt;peterx@redhat.com&gt;
Tested-by: Chris Wilson &lt;chris@chris-wilson.co.uk&gt;
Signed-off-by: Joerg Roedel &lt;jroedel@suse.de&gt;
</content>
</entry>
<entry>
<title>treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500</title>
<updated>2019-06-19T15:09:55+00:00</updated>
<author>
<name>Thomas Gleixner</name>
<email>tglx@linutronix.de</email>
</author>
<published>2019-06-04T08:11:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=d2912cb15bdda8ba4a5dd73396ad62641af2f520'/>
<id>urn:sha1:d2912cb15bdda8ba4a5dd73396ad62641af2f520</id>
<content type='text'>
Based on 2 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation #

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Reviewed-by: Enrico Weigelt &lt;info@metux.net&gt;
Reviewed-by: Kate Stewart &lt;kstewart@linuxfoundation.org&gt;
Reviewed-by: Allison Randal &lt;allison@lohutok.net&gt;
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 234</title>
<updated>2019-06-19T15:09:07+00:00</updated>
<author>
<name>Thomas Gleixner</name>
<email>tglx@linutronix.de</email>
</author>
<published>2019-06-03T05:44:50+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/BMC/Intel-BMC/linux.git/commit/?id=caab277b1de0a22b675c4c95fc7b285ec2eb5bf5'/>
<id>urn:sha1:caab277b1de0a22b675c4c95fc7b285ec2eb5bf5</id>
<content type='text'>
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation this program is
  distributed in the hope that it will be useful but without any
  warranty without even the implied warranty of merchantability or
  fitness for a particular purpose see the gnu general public license
  for more details you should have received a copy of the gnu general
  public license along with this program if not see http www gnu org
  licenses

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 503 file(s).

Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Reviewed-by: Alexios Zavras &lt;alexios.zavras@intel.com&gt;
Reviewed-by: Allison Randal &lt;allison@lohutok.net&gt;
Reviewed-by: Enrico Weigelt &lt;info@metux.net&gt;
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190602204653.811534538@linutronix.de
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
</feed>
