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Linux kernel source tree
c9e78afa68
While configuring a vxlan tunnel in a system with a i40e NIC driver, I
observe the following deadlock:
WARNING: possible recursive locking detected
6.16.0-rc2.net-next-6.16_92d87230d899+ #13 Tainted: G E
--------------------------------------------
kworker/u256:4/1125 is trying to acquire lock:
ffff88921ab9c8c8 (&utn->lock){+.+.}-{4:4}, at: i40e_udp_tunnel_set_port (/home/pabeni/net-next/include/net/udp_tunnel.h:343 /home/pabeni/net-next/drivers/net/ethernet/intel/i40e/i40e_main.c:13013) i40e
but task is already holding lock:
ffff88921ab9c8c8 (&utn->lock){+.+.}-{4:4}, at: udp_tunnel_nic_device_sync_work (/home/pabeni/net-next/net/ipv4/udp_tunnel_nic.c:739) udp_tunnel
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(&utn->lock);
lock(&utn->lock);
*** DEADLOCK ***
May be due to missing lock nesting notation
4 locks held by kworker/u256:4/1125:
#0: ffff8892910ca158 ((wq_completion)udp_tunnel_nic){+.+.}-{0:0}, at: process_one_work (/home/pabeni/net-next/kernel/workqueue.c:3213)
#1: ffffc900244efd30 ((work_completion)(&utn->work)){+.+.}-{0:0}, at: process_one_work (/home/pabeni/net-next/kernel/workqueue.c:3214)
#2: ffffffff9a14e290 (rtnl_mutex){+.+.}-{4:4}, at: udp_tunnel_nic_device_sync_work (/home/pabeni/net-next/net/ipv4/udp_tunnel_nic.c:737) udp_tunnel
#3: ffff88921ab9c8c8 (&utn->lock){+.+.}-{4:4}, at: udp_tunnel_nic_device_sync_work (/home/pabeni/net-next/net/ipv4/udp_tunnel_nic.c:739) udp_tunnel
stack backtrace:
Hardware name: Dell Inc. PowerEdge R7525/0YHMCJ, BIOS 2.2.5 04/08/2021
i
Call Trace:
<TASK>
dump_stack_lvl (/home/pabeni/net-next/lib/dump_stack.c:123)
print_deadlock_bug (/home/pabeni/net-next/kernel/locking/lockdep.c:3047)
validate_chain (/home/pabeni/net-next/kernel/locking/lockdep.c:3901)
__lock_acquire (/home/pabeni/net-next/kernel/locking/lockdep.c:5240)
lock_acquire.part.0 (/home/pabeni/net-next/kernel/locking/lockdep.c:473 /home/pabeni/net-next/kernel/locking/lockdep.c:5873)
__mutex_lock (/home/pabeni/net-next/kernel/locking/mutex.c:604 /home/pabeni/net-next/kernel/locking/mutex.c:747)
i40e_udp_tunnel_set_port (/home/pabeni/net-next/include/net/udp_tunnel.h:343 /home/pabeni/net-next/drivers/net/ethernet/intel/i40e/i40e_main.c:13013) i40e
udp_tunnel_nic_device_sync_by_port (/home/pabeni/net-next/net/ipv4/udp_tunnel_nic.c:230 /home/pabeni/net-next/net/ipv4/udp_tunnel_nic.c:249) udp_tunnel
__udp_tunnel_nic_device_sync.part.0 (/home/pabeni/net-next/net/ipv4/udp_tunnel_nic.c:292) udp_tunnel
udp_tunnel_nic_device_sync_work (/home/pabeni/net-next/net/ipv4/udp_tunnel_nic.c:742) udp_tunnel
process_one_work (/home/pabeni/net-next/kernel/workqueue.c:3243)
worker_thread (/home/pabeni/net-next/kernel/workqueue.c:3315 /home/pabeni/net-next/kernel/workqueue.c:3402)
kthread (/home/pabeni/net-next/kernel/kthread.c:464)
AFAICS all the existing callsites of udp_tunnel_nic_set_port_priv() are
already under the utn lock scope, avoid (re-)acquiring it in such a
function.
Fixes:
|
||
|---|---|---|
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| io_uring | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| rust | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .clippy.toml | ||
| .cocciconfig | ||
| .editorconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| .pylintrc | ||
| .rustfmt.toml | ||
| 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 reStructuredText 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.