Hi All,
When testing the 6.6 kernel release with lockdep
enabled on a Dell Latitude 9420 laptop, I got
the below lockdep warning.
I'm happy to test any patches to address this.
[ 2.973360] pci 10000:e0:06.0: BAR 14: assigned [mem 0xbc000000-0xbc0fffff]
[ 2.973365] pci 10000:e0:06.0: BAR 13: no space for [io size 0x1000]
[ 2.973367] pci 10000:e0:06.0: BAR 13: failed to assign [io size 0x1000]
[ 2.973370] pci 10000:e1:00.0: BAR 0: assigned [mem 0xbc000000-0xbc003fff 64bit]
[ 2.973381] pci 10000:e0:06.0: PCI bridge to [bus e1]
[ 2.973385] pci 10000:e0:06.0: bridge window [mem 0xbc000000-0xbc0fffff]
[ 2.973407] ============================================
[ 2.973409] WARNING: possible recursive locking detected
[ 2.973411] 6.6.0+ #118 Not tainted
[ 2.973413] --------------------------------------------
[ 2.973415] (udev-worker)/425 is trying to acquire lock:
[ 2.973417] ffffffffb5ec8830 (pci_bus_sem){++++}-{3:3}, at: pci_enable_link_state+0x77/0x1b0
[ 2.973426]
but task is already holding lock:
[ 2.973428] ffffffffb5ec8830 (pci_bus_sem){++++}-{3:3}, at: pci_walk_bus+0x25/0x90
[ 2.973433]
other info that might help us debug this:
[ 2.973436] Possible unsafe locking scenario:
[ 2.973438] CPU0
[ 2.973439] ----
[ 2.973440] lock(pci_bus_sem);
[ 2.973442] lock(pci_bus_sem);
[ 2.973443]
*** DEADLOCK ***
[ 2.973445] May be due to missing lock nesting notation
[ 2.973448] 2 locks held by (udev-worker)/425:
[ 2.973450] #0: ffff88810279d1a8 (&dev->mutex){....}-{3:3}, at: __driver_attach+0xc7/0x1c0
[ 2.973456] #1: ffffffffb5ec8830 (pci_bus_sem){++++}-{3:3}, at: pci_walk_bus+0x25/0x90
[ 2.973461]
stack backtrace:
[ 2.973463] CPU: 6 PID: 425 Comm: (udev-worker) Not tainted 6.6.0+ #118
[ 2.973466] Hardware name: Dell Inc. Latitude 9420/, BIOS 1.23.0 07/10/2023
[ 2.973469] Call Trace:
[ 2.973471] <TASK>
[ 2.973472] dump_stack_lvl+0x57/0x90
[ 2.973477] __lock_acquire+0x1272/0x2190
[ 2.973482] lock_acquire+0xc4/0x290
[ 2.973485] ? pci_enable_link_state+0x77/0x1b0
[ 2.973489] down_read+0x3e/0x190
[ 2.973493] ? pci_enable_link_state+0x77/0x1b0
[ 2.973496] pci_enable_link_state+0x77/0x1b0
[ 2.973500] ? __pfx_vmd_pm_enable_quirk+0x10/0x10 [vmd]
[ 2.973505] vmd_pm_enable_quirk+0x24/0xa0 [vmd]
[ 2.973510] ? down_read+0x48/0x190
[ 2.973512] pci_walk_bus+0x6f/0x90
[ 2.973515] vmd_probe+0x7e9/0xa40 [vmd]
[ 2.973520] local_pci_probe+0x3e/0x90
[ 2.973523] pci_device_probe+0xb3/0x210
[ 2.973527] really_probe+0x19b/0x3e0
[ 2.973529] ? __pfx___driver_attach+0x10/0x10
[ 2.973532] __driver_probe_device+0x78/0x160
[ 2.973535] driver_probe_device+0x1f/0x90
[ 2.973537] __driver_attach+0xd2/0x1c0
[ 2.973540] bus_for_each_dev+0x63/0xa0
[ 2.973543] bus_add_driver+0x115/0x210
[ 2.973546] driver_register+0x55/0x100
[ 2.973548] ? __pfx_vmd_drv_init+0x10/0x10 [vmd]
[ 2.973553] do_one_initcall+0x5a/0x360
[ 2.973557] ? rcu_is_watching+0xd/0x40
[ 2.973561] ? kmalloc_trace+0xa5/0xb0
[ 2.973565] do_init_module+0x60/0x230
[ 2.973569] __do_sys_init_module+0x16a/0x1a0
[ 2.973571] ? __seccomp_filter+0x320/0x510
[ 2.973577] do_syscall_64+0x59/0x90
[ 2.973580] ? do_user_addr_fault+0x366/0x830
[ 2.973584] ? exc_page_fault+0xf1/0x200
[ 2.973588] ? asm_exc_page_fault+0x22/0x30
[ 2.973592] ? lockdep_hardirqs_on+0x7d/0x100
[ 2.973594] entry_SYSCALL_64_after_hwframe+0x6e/0xd8
[ 2.973597] RIP: 0033:0x7f84bedcf7fe
[ 2.973600] Code: 48 8b 0d 35 16 0c 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 49 89 ca b8 af 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 02 16 0c 00 f7 d8 64 89 01 48
[ 2.973606] RSP: 002b:00007fff04d64ea8 EFLAGS: 00000246 ORIG_RAX: 00000000000000af
[ 2.973609] RAX: ffffffffffffffda RBX: 000055589fb73360 RCX: 00007f84bedcf7fe
[ 2.973612] RDX: 00007f84beed507d RSI: 000000000000a3b9 RDI: 00005558a037de70
[ 2.973614] RBP: 00007fff04d64f60 R08: 000055589fb44010 R09: 0000000000000007
[ 2.973617] R10: 0000000000000002 R11: 0000000000000246 R12: 00007f84beed507d
[ 2.973619] R13: 0000000000020000 R14: 000055589fb6c760 R15: 000055589fb74c70
[ 2.973623] </TASK>
[ 2.974292] pci 10000:e1:00.0: VMD: Default LTR value set by driver
Regards,
Hans
