d59b73a66e
Add a lock_class_key per mlx5 device to avoid a false positive
"possible circular locking dependency" warning by lockdep, on flows
which lock more than one mlx5 device, such as adding SF.
kernel log:
======================================================
WARNING: possible circular locking dependency detected
5.19.0-rc8+ #2 Not tainted
------------------------------------------------------
kworker/u20:0/8 is trying to acquire lock:
ffff88812dfe0d98 (&dev->intf_state_mutex){+.+.}-{3:3}, at: mlx5_init_one+0x2e/0x490 [mlx5_core]
but task is already holding lock:
ffff888101aa7898 (&(¬ifier->n_head)->rwsem){++++}-{3:3}, at: blocking_notifier_call_chain+0x5a/0x130
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (&(¬ifier->n_head)->rwsem){++++}-{3:3}:
down_write+0x90/0x150
blocking_notifier_chain_register+0x53/0xa0
mlx5_sf_table_init+0x369/0x4a0 [mlx5_core]
mlx5_init_one+0x261/0x490 [mlx5_core]
probe_one+0x430/0x680 [mlx5_core]
local_pci_probe+0xd6/0x170
work_for_cpu_fn+0x4e/0xa0
process_one_work+0x7c2/0x1340
worker_thread+0x6f6/0xec0
kthread+0x28f/0x330
ret_from_fork+0x1f/0x30
-> #0 (&dev->intf_state_mutex){+.+.}-{3:3}:
__lock_acquire+0x2fc7/0x6720
lock_acquire+0x1c1/0x550
__mutex_lock+0x12c/0x14b0
mlx5_init_one+0x2e/0x490 [mlx5_core]
mlx5_sf_dev_probe+0x29c/0x370 [mlx5_core]
auxiliary_bus_probe+0x9d/0xe0
really_probe+0x1e0/0xaa0
__driver_probe_device+0x219/0x480
driver_probe_device+0x49/0x130
__device_attach_driver+0x1b8/0x280
bus_for_each_drv+0x123/0x1a0
__device_attach+0x1a3/0x460
bus_probe_device+0x1a2/0x260
device_add+0x9b1/0x1b40
__auxiliary_device_add+0x88/0xc0
mlx5_sf_dev_state_change_handler+0x67e/0x9d0 [mlx5_core]
blocking_notifier_call_chain+0xd5/0x130
mlx5_vhca_state_work_handler+0x2b0/0x3f0 [mlx5_core]
process_one_work+0x7c2/0x1340
worker_thread+0x59d/0xec0
kthread+0x28f/0x330
ret_from_fork+0x1f/0x30
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&(¬ifier->n_head)->rwsem);
lock(&dev->intf_state_mutex);
lock(&(¬ifier->n_head)->rwsem);
lock(&dev->intf_state_mutex);
*** DEADLOCK ***
4 locks held by kworker/u20:0/8:
#0: ffff888150612938 ((wq_completion)mlx5_events){+.+.}-{0:0}, at: process_one_work+0x6e2/0x1340
#1: ffff888100cafdb8 ((work_completion)(&work->work)#3){+.+.}-{0:0}, at: process_one_work+0x70f/0x1340
#2: ffff888101aa7898 (&(¬ifier->n_head)->rwsem){++++}-{3:3}, at: blocking_notifier_call_chain+0x5a/0x130
#3: ffff88813682d0e8 (&dev->mutex){....}-{3:3}, at:__device_attach+0x76/0x460
stack backtrace:
CPU: 6 PID: 8 Comm: kworker/u20:0 Not tainted 5.19.0-rc8+
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
Workqueue: mlx5_events mlx5_vhca_state_work_handler [mlx5_core]
Call Trace:
<TASK>
dump_stack_lvl+0x57/0x7d
check_noncircular+0x278/0x300
? print_circular_bug+0x460/0x460
? lock_chain_count+0x20/0x20
? register_lock_class+0x1880/0x1880
__lock_acquire+0x2fc7/0x6720
? register_lock_class+0x1880/0x1880
? register_lock_class+0x1880/0x1880
lock_acquire+0x1c1/0x550
? mlx5_init_one+0x2e/0x490 [mlx5_core]
? lockdep_hardirqs_on_prepare+0x400/0x400
__mutex_lock+0x12c/0x14b0
? mlx5_init_one+0x2e/0x490 [mlx5_core]
? mlx5_init_one+0x2e/0x490 [mlx5_core]
? _raw_read_unlock+0x1f/0x30
? mutex_lock_io_nested+0x1320/0x1320
? __ioremap_caller.constprop.0+0x306/0x490
? mlx5_sf_dev_probe+0x269/0x370 [mlx5_core]
? iounmap+0x160/0x160
mlx5_init_one+0x2e/0x490 [mlx5_core]
mlx5_sf_dev_probe+0x29c/0x370 [mlx5_core]
? mlx5_sf_dev_remove+0x130/0x130 [mlx5_core]
auxiliary_bus_probe+0x9d/0xe0
really_probe+0x1e0/0xaa0
__driver_probe_device+0x219/0x480
? auxiliary_match_id+0xe9/0x140
driver_probe_device+0x49/0x130
__device_attach_driver+0x1b8/0x280
? driver_allows_async_probing+0x140/0x140
bus_for_each_drv+0x123/0x1a0
? bus_for_each_dev+0x1a0/0x1a0
? lockdep_hardirqs_on_prepare+0x286/0x400
? trace_hardirqs_on+0x2d/0x100
__device_attach+0x1a3/0x460
? device_driver_attach+0x1e0/0x1e0
? kobject_uevent_env+0x22d/0xf10
bus_probe_device+0x1a2/0x260
device_add+0x9b1/0x1b40
? dev_set_name+0xab/0xe0
? __fw_devlink_link_to_suppliers+0x260/0x260
? memset+0x20/0x40
? lockdep_init_map_type+0x21a/0x7d0
__auxiliary_device_add+0x88/0xc0
? auxiliary_device_init+0x86/0xa0
mlx5_sf_dev_state_change_handler+0x67e/0x9d0 [mlx5_core]
blocking_notifier_call_chain+0xd5/0x130
mlx5_vhca_state_work_handler+0x2b0/0x3f0 [mlx5_core]
? mlx5_vhca_event_arm+0x100/0x100 [mlx5_core]
? lock_downgrade+0x6e0/0x6e0
? lockdep_hardirqs_on_prepare+0x286/0x400
process_one_work+0x7c2/0x1340
? lockdep_hardirqs_on_prepare+0x400/0x400
? pwq_dec_nr_in_flight+0x230/0x230
? rwlock_bug.part.0+0x90/0x90
worker_thread+0x59d/0xec0
? process_one_work+0x1340/0x1340
kthread+0x28f/0x330
? kthread_complete_and_exit+0x20/0x20
ret_from_fork+0x1f/0x30
</TASK>
Fixes:
|
||
|---|---|---|
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| io_uring | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.