Re: Lockdep annotation introduced warn in VMD driver

[Jani Nikula <jani.nikula@linux.intel.com>]

On Tue, 28 May 2024, Nirmal Patel <nirmal.patel@linux.intel.com> wrote:
> On Tue, 28 May 2024 15:36:54 +0300
> Imre Deak <imre.deak@intel.com> wrote:
>
>> Hi,
>> 
>> commit 7e89efc6e9e402839643cb297bab14055c547f07
>> Author: Dave Jiang <dave.jiang@intel.com>
>> Date:   Thu May 2 09:57:31 2024 -0700
>> 
>>     PCI: Lock upstream bridge for pci_reset_function()
>> 
>> introduced the WARN below in the VMD driver, see [1] for the full log.
>> Not sure if the annotation is incorrect or the VMD driver is missing
>> the lock, CC'ing VMD folks.
>> 
>> --Imre
> Can you please provide repro steps and some background on the setup?

Hardware name: Intel Corporation Alder Lake Client Platform/AlderLake-P
LP5 RVP.

Kconfig: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_14842/kconfig.txt

Just booting with the above commit is enough.

BR,
Jani.

>
> -nirmal
>> 
>> https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_134112v1/bat-adlp-11/boot0.txt
>> 
>> <4>[   17.354071] WARNING: CPU: 0 PID: 1 at drivers/pci/pci.c:4886
>> pci_bridge_secondary_bus_reset+0x5d/0x70 <4>[   17.354095] Modules
>> linked in: <4>[   17.354104] CPU: 0 PID: 1 Comm: swapper/0 Not
>> tainted 6.10.0-rc1-Patchwork_134112v1-gabaeae202dfb+ #1 <4>[
>> 17.354128] Hardware name: Intel Corporation Alder Lake Client
>> Platform/AlderLake-P LP5 RVP, BIOS RPLPFWI1.R00.4035.A00.2301200723
>> 01/20/2023 <4>[   17.354153] RIP:
>> 0010:pci_bridge_secondary_bus_reset+0x5d/0x70 <4>[   17.354167] Code:
>> c3 cc cc cc cc 48 89 ef 48 c7 c6 78 55 44 82 5d e9 d8 c6 ff ff 48 8d
>> bf 48 08 00 00 be ff ff ff ff e8 97 10 5f 00 85 c0 75 b5 <0f> 0b eb
>> b1 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 90 90 90 <4>[
>> 17.354199] RSP: 0000:ffffc90000097ca0 EFLAGS: 00010246 <4>[
>> 17.354210] RAX: 0000000000000000 RBX: ffff888105604000 RCX:
>> 0000000000000000 <4>[   17.354224] RDX: 0000000080000000 RSI:
>> ffffffff82421c40 RDI: ffffffff82441c4c <4>[   17.354238] RBP:
>> ffff888105601000 R08: 0000000000000001 R09: 0000000000000000 <4>[
>> 17.354251] R10: 0000000000000001 R11: ffff8881008c8040 R12:
>> 0000000000000000 <4>[   17.354264] R13: 0000000000000020 R14:
>> 000000000000007f R15: ffff888105615c28 <4>[   17.354283] FS:
>> 0000000000000000(0000) GS:ffff8882a6e00000(0000)
>> knlGS:0000000000000000 <4>[   17.354313] CS:  0010 DS: 0000 ES: 0000
>> CR0: 0000000080050033 <4>[   17.354334] CR2: ffff8882afbff000 CR3:
>> 000000000663a000 CR4: 0000000000f50ef0 <4>[   17.354348] PKRU:
>> 55555554 <4>[   17.354355] Call Trace: <4>[   17.354361]  <TASK> <4>[
>>   17.354367]  ? __warn+0x8c/0x190 <4>[   17.354380]  ?
>> pci_bridge_secondary_bus_reset+0x5d/0x70 <4>[   17.354392]  ?
>> report_bug+0x1f8/0x200 <4>[   17.354405]  ? handle_bug+0x3c/0x70 <4>[
>>   17.354415]  ? exc_invalid_op+0x18/0x70 <4>[   17.354424]  ?
>> asm_exc_invalid_op+0x1a/0x20 <4>[   17.354438]  ?
>> pci_bridge_secondary_bus_reset+0x5d/0x70 <4>[   17.354451]
>> pci_reset_bus+0x1d8/0x270 <4>[   17.354461]  vmd_probe+0x778/0xa10
>> <4>[   17.354474]  pci_device_probe+0x95/0x120 <4>[   17.354484]
>> really_probe+0xd9/0x370 <4>[   17.354496]  ?
>> __pfx___driver_attach+0x10/0x10 <4>[   17.354505]
>> __driver_probe_device+0x73/0x150 <4>[   17.354516]
>> driver_probe_device+0x19/0xa0 <4>[   17.354525]
>> __driver_attach+0xb6/0x180 <4>[   17.354534]  ?
>> __pfx___driver_attach+0x10/0x10 <4>[   17.354544]
>> bus_for_each_dev+0x77/0xd0 <4>[   17.354555]
>> bus_add_driver+0x110/0x240 <4>[   17.354566]
>> driver_register+0x5b/0x110 <4>[   17.354575]  ?
>> __pfx_vmd_drv_init+0x10/0x10 <4>[   17.354587]
>> do_one_initcall+0x5c/0x2b0 <4>[   17.354600]
>> kernel_init_freeable+0x18e/0x340 <4>[   17.354612]  ?
>> __pfx_kernel_init+0x10/0x10 <4>[   17.354623]  kernel_init+0x15/0x130
>> <4>[   17.354631]  ret_from_fork+0x2c/0x50 <4>[   17.354641]  ?
>> __pfx_kernel_init+0x10/0x10 <4>[   17.354650]
>> ret_from_fork_asm+0x1a/0x30 <4>[   17.354663]  </TASK> <4>[
>> 17.354669] irq event stamp: 28577685 <4>[   17.354677] hardirqs last
>> enabled at (28577693): [<ffffffff8117c060>]
>> console_unlock+0x110/0x120 <4>[   17.354697] hardirqs last disabled
>> at (28577700): [<ffffffff8117c045>] console_unlock+0xf5/0x120 <4>[
>> 17.354713] softirqs last  enabled at (28577176): [<ffffffff810df29c>]
>> handle_softirqs+0x2ec/0x3f0 <4>[   17.354731] softirqs last disabled
>> at (28577167): [<ffffffff810dfa17>] irq_exit_rcu+0x87/0xc0 <4>[
>> 17.354747] ---[ end trace 0000000000000000 ]---
>> 
>> <4>[   17.487274] =====================================
>> <4>[   17.487277] WARNING: bad unlock balance detected!
>> <4>[   17.487279] 6.10.0-rc1-Patchwork_134112v1-gabaeae202dfb+ #1
>> Tainted: G        W <4>[   17.487282]
>> ------------------------------------- <4>[   17.487284] swapper/0/1
>> is trying to release lock (10000:e1:00.0) at: <4>[   17.487287]
>> [<ffffffff8176b377>] pci_cfg_access_unlock+0x57/0x60 <4>[
>> 17.487292] but there are no more locks to release! <4>[   17.487294]
>>                   other info that might help us debug this:
>> <4>[   17.487297] 2 locks held by swapper/0/1:
>> <4>[   17.487299]  #0: ffff888102c1c1b0 (&dev->mutex){....}-{3:3},
>> at: __driver_attach+0xab/0x180 <4>[   17.487306]  #1:
>> ffff8881056041b0 (&dev->mutex){....}-{3:3}, at:
>> pci_dev_trylock+0x19/0x50 <4>[   17.487312] stack backtrace:
>> <4>[   17.487314] CPU: 0 PID: 1 Comm: swapper/0 Tainted: G        W
>>        6.10.0-rc1-Patchwork_134112v1-gabaeae202dfb+ #1 <4>[
>> 17.487318] Hardware name: Intel Corporation Alder Lake Client
>> Platform/AlderLake-P LP5 RVP, BIOS RPLPFWI1.R00.4035.A00.2301200723
>> 01/20/2023 <4>[   17.487322] Call Trace: <4>[   17.487324]  <TASK>
>> <4>[   17.487325]  dump_stack_lvl+0x82/0xd0 <4>[   17.487329]
>> lock_release+0x20b/0x2d0 <4>[   17.487334]  pci_bus_unlock+0x25/0x40
>> <4>[   17.487337]  pci_reset_bus+0x1eb/0x270
>> <4>[   17.487340]  vmd_probe+0x778/0xa10
>> <4>[   17.487344]  pci_device_probe+0x95/0x120
>> <4>[   17.487346]  really_probe+0xd9/0x370
>> <4>[   17.487349]  ? __pfx___driver_attach+0x10/0x10
>> <4>[   17.487352]  __driver_probe_device+0x73/0x150
>> <4>[   17.487354]  driver_probe_device+0x19/0xa0
>> <4>[   17.487357]  __driver_attach+0xb6/0x180
>> <4>[   17.487359]  ? __pfx___driver_attach+0x10/0x10
>> <4>[   17.487362]  bus_for_each_dev+0x77/0xd0
>> <4>[   17.487365]  bus_add_driver+0x110/0x240
>> <4>[   17.487369]  driver_register+0x5b/0x110
>> <4>[   17.487371]  ? __pfx_vmd_drv_init+0x10/0x10
>> <4>[   17.487374]  do_one_initcall+0x5c/0x2b0
>> <4>[   17.487378]  kernel_init_freeable+0x18e/0x340
>> <4>[   17.487381]  ? __pfx_kernel_init+0x10/0x10
>> <4>[   17.487384]  kernel_init+0x15/0x130
>> <4>[   17.487387]  ret_from_fork+0x2c/0x50
>> <4>[   17.487390]  ? __pfx_kernel_init+0x10/0x10
>> <4>[   17.487392]  ret_from_fork_asm+0x1a/0x30
>> <4>[   17.487396]  </TASK>
>> 
>

-- 
Jani Nikula, Intel