On 2022/11/2 19:17, Baolu Lu wrote:
On 2022/9/22 18:10, Janusz Krzysztofik wrote:
From: Chris Wilson<chris@xxxxxxxxxxxxxxxxxx>
Manual revert of commit f598a497bc7d ("iova: Add CPU hotplug handler to
flush rcaches"). It is trying to instantiate a cpuhp notifier from
inside
a cpuhp callback. That code replaced intel_iommu implementation of
flushing per-IOVA domain CPU rcaches which used a single instance of
cpuhp
held for the module lifetime.
<4>[ 6.928112] ======================================================
<4>[ 6.928621] WARNING: possible circular locking dependency detected
<4>[ 6.929225] 6.0.0-rc6-CI_DRM_12164-ga1f63e144e54+ #1 Not tainted
<4>[ 6.929818] ------------------------------------------------------
<4>[ 6.930415] cpuhp/0/15 is trying to acquire lock:
<4>[ 6.931011] ffff888100e02a78
(&(&priv->bus_notifier)->rwsem){++++}-{3:3}, at:
blocking_notifier_call_chain+0x20/0x50
<4>[ 6.931533]
but task is already holding lock:
<4>[ 6.931534] ffffffff826490c0 (cpuhp_state-up){+.+.}-{0:0}, at:
cpuhp_thread_fun+0x48/0x1f0
<4>[ 6.933069]
which lock already depends on the new lock.
Just FYI.
Hot plugging a PCI device will trigger a similar lockdep warning.
#echo 1 > /sys/bus/pci/devices/.../remove
With this patch applied, the warning disappeared.
The following kernel trace is generated by my experimental code. Please
ignore it. Sorry for the inconvenience.
[ 2599.612285] BUG: kernel NULL pointer dereference, address:
0000000000000064
[ 2599.622454] #PF: supervisor read access in kernel mode
[ 2599.630460] #PF: error_code(0x0000) - not-present page
[ 2599.638473] PGD 109f7d067 P4D 0
[ 2599.644274] Oops: 0000 [#1] PREEMPT SMP NOPTI
[ 2599.651385] CPU: 0 PID: 828 Comm: bash Tainted: G I
6.1.0-rc2+ #367
[ 2599.677439] RIP: 0010:do_raw_spin_lock+0xa/0xc0
[ 2599.684796] Code: 8d 88 80 0b 00 00 48 c7 c7 d8 39 cd 91 e8 c7 c2 06
01 e9 e8 32 0e 01 66 0f 1f 84 00 00 00 00 00 66 0f 1f 00 0f 1f 44 00 00
53 <8b> 47 04 48 89 fb 3d ad 4e ad de 75 4a 48 8b 53 10 65 48 8b 04 25
[ 2599.711073] RSP: 0018:ff5efa9101b27ca8 EFLAGS: 00010092
[ 2599.719254] RAX: 0000000000000000 RBX: 0000000000000206 RCX:
0000000000000000
[ 2599.729869] RDX: 0000000000000000 RSI: 0000000000000000 RDI:
0000000000000060
[ 2599.740427] RBP: 0000000000000060 R08: 0000000000000001 R09:
0000000000000000
[ 2599.750985] R10: 0000000000000000 R11: ffffffff95b0be60 R12:
ff24417986fce000
[ 2599.761500] R13: ffffffff959f9bf0 R14: ff244179872d5058 R15:
0000000000000003
[ 2599.772114] FS: 00007f04aa2b1740(0000) GS:ff244180dfc00000(0000)
knlGS:0000000000000000
[ 2599.783841] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 2599.792747] CR2: 0000000000000064 CR3: 000000010a6a2004 CR4:
0000000000771ef0
[ 2599.803372] DR0: 0000000000000000 DR1: 0000000000000000 DR2:
0000000000000000
[ 2599.813976] DR3: 0000000000000000 DR6: 00000000ffff07f0 DR7:
0000000000000400
[ 2599.824572] PKRU: 55555554
[ 2599.829655] Call Trace:
[ 2599.834444] <TASK>
[ 2599.838833] _raw_spin_lock_irqsave+0x41/0x60
[ 2599.846048] ? domain_update_iotlb+0x16/0x60
[ 2599.853147] domain_update_iotlb+0x16/0x60
[ 2599.859946] intel_iommu_release_device+0xc5/0xd0
[ 2599.867549] iommu_release_device+0x49/0x80
[ 2599.874444] iommu_bus_notifier+0x24/0x50
[ 2599.881139] notifier_call_chain+0x3a/0xa0
[ 2599.887936] blocking_notifier_call_chain+0x43/0x60
[ 2599.895736] device_del+0x2b4/0x420
[ 2599.901829] pci_remove_bus_device+0x70/0x110
[ 2599.909034] pci_stop_and_remove_bus_device_locked+0x22/0x30
[ 2599.917852] remove_store+0x7d/0x90
[ 2599.923949] kernfs_fop_write_iter+0x12a/0x1d0
[ 2599.931253] vfs_write+0x313/0x4b0
[ 2599.937247] ksys_write+0x60/0xe0
[ 2599.943095] do_syscall_64+0x43/0x90
[ 2599.949245] entry_SYSCALL_64_after_hwframe+0x63/0xcd
[ 2599.957135] RIP: 0033:0x7f04a9d18a98
[ 2599.963213] Code: 89 02 48 c7 c0 ff ff ff ff eb b3 0f 1f 80 00 00 00
00 f3 0f 1e fa 48 8d 05 05 26 0f 00 8b 00 85 c0 75 1f b8 01 00 00 00 0f
05 <0f> 1f 84 00 00 00 00 00 48 3d 00 f0 ff ff 77 58 c3 0f 1f 80 00 00
[ 2599.989405] RSP: 002b:00007ffc28cce9e8 EFLAGS: 00000246 ORIG_RAX:
0000000000000001
[ 2600.000537] RAX: ffffffffffffffda RBX: 0000000000000002 RCX:
00007f04a9d18a98
[ 2600.011155] RDX: 0000000000000002 RSI: 000055d272355f60 RDI:
0000000000000001
[ 2600.021748] RBP: 000055d272355f60 R08: 000000000000000a R09:
0000000000000001
[ 2600.032334] R10: 000000000000000a R11: 0000000000000246 R12:
00007f04a9e06520
[ 2600.042923] R13: 0000000000000002 R14: 00007f04a9e07260 R15:
00007f04a9e06720
[ 2600.053527] </TASK>
[ 2600.057993] Modules linked in: fuse x86_pkg_temp_thermal
intel_powerclamp coretemp kvm_intel kvm irqbypass isst_if_mmio
isst_if_common joydev intel_vsec idxd cxl_acpi cxl_core sunrpc
crc32c_intel ixgbe mdio dca bochs drm_vram_helper drm_ttm_helper
[ 2600.088403] CR2: 0000000000000064
[ 2600.094376] ---[ end trace 0000000000000000 ]---
[ 2600.238419] RIP: 0010:do_raw_spin_lock+0xa/0xc0
[ 2600.245811] Code: 8d 88 80 0b 00 00 48 c7 c7 d8 39 cd 91 e8 c7 c2 06
01 e9 e8 32 0e 01 66 0f 1f 84 00 00 00 00 00 66 0f 1f 00 0f 1f 44 00 00
53 <8b> 47 04 48 89 fb 3d ad 4e ad de 75 4a 48 8b 53 10 65 48 8b 04 25
[ 2600.272091] RSP: 0018:ff5efa9101b27ca8 EFLAGS: 00010092
[ 2600.280345] RAX: 0000000000000000 RBX: 0000000000000206 RCX:
0000000000000000
[ 2600.290980] RDX: 0000000000000000 RSI: 0000000000000000 RDI:
0000000000000060
[ 2600.301580] RBP: 0000000000000060 R08: 0000000000000001 R09:
0000000000000000
[ 2600.312167] R10: 0000000000000000 R11: ffffffff95b0be60 R12:
ff24417986fce000
[ 2600.322762] R13: ffffffff959f9bf0 R14: ff244179872d5058 R15:
0000000000000003
[ 2600.333354] FS: 00007f04aa2b1740(0000) GS:ff244180dfc00000(0000)
knlGS:0000000000000000
[ 2600.345062] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 2600.353949] CR2: 0000000000000064 CR3: 000000010a6a2004 CR4:
0000000000771ef0
[ 2600.364571] DR0: 0000000000000000 DR1: 0000000000000000 DR2:
0000000000000000
[ 2600.375178] DR3: 0000000000000000 DR6: 00000000ffff07f0 DR7:
0000000000000400
[ 2600.385756] PKRU: 55555554
[ 2600.390848] note: bash[828] exited with preempt_count 1
Best regards,
baolu
