369f61bee0
team interface could be nested and it's lock variable could be nested too.
But this lock uses static lockdep key and there is no nested locking
handling code such as mutex_lock_nested() and so on.
so the Lockdep would warn about the circular locking scenario that
couldn't happen.
In order to fix, this patch makes the team module to use dynamic lock key
instead of static key.
Test commands:
ip link add team0 type team
ip link add team1 type team
ip link set team0 master team1
ip link set team0 nomaster
ip link set team1 master team0
ip link set team1 nomaster
Splat that looks like:
[ 40.364352] WARNING: possible recursive locking detected
[ 40.364964] 5.4.0-rc3+ #96 Not tainted
[ 40.365405] --------------------------------------------
[ 40.365973] ip/750 is trying to acquire lock:
[ 40.366542] ffff888060b34c40 (&team->lock){+.+.}, at: team_set_mac_address+0x151/0x290 [team]
[ 40.367689]
but task is already holding lock:
[ 40.368729] ffff888051201c40 (&team->lock){+.+.}, at: team_del_slave+0x29/0x60 [team]
[ 40.370280]
other info that might help us debug this:
[ 40.371159] Possible unsafe locking scenario:
[ 40.371942] CPU0
[ 40.372338] ----
[ 40.372673] lock(&team->lock);
[ 40.373115] lock(&team->lock);
[ 40.373549]
*** DEADLOCK ***
[ 40.374432] May be due to missing lock nesting notation
[ 40.375338] 2 locks held by ip/750:
[ 40.375851] #0: ffffffffabcc42b0 (rtnl_mutex){+.+.}, at: rtnetlink_rcv_msg+0x466/0x8a0
[ 40.376927] #1: ffff888051201c40 (&team->lock){+.+.}, at: team_del_slave+0x29/0x60 [team]
[ 40.377989]
stack backtrace:
[ 40.378650] CPU: 0 PID: 750 Comm: ip Not tainted 5.4.0-rc3+ #96
[ 40.379368] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
[ 40.380574] Call Trace:
[ 40.381208] dump_stack+0x7c/0xbb
[ 40.381959] __lock_acquire+0x269d/0x3de0
[ 40.382817] ? register_lock_class+0x14d0/0x14d0
[ 40.383784] ? check_chain_key+0x236/0x5d0
[ 40.384518] lock_acquire+0x164/0x3b0
[ 40.385074] ? team_set_mac_address+0x151/0x290 [team]
[ 40.385805] __mutex_lock+0x14d/0x14c0
[ 40.386371] ? team_set_mac_address+0x151/0x290 [team]
[ 40.387038] ? team_set_mac_address+0x151/0x290 [team]
[ 40.387632] ? mutex_lock_io_nested+0x1380/0x1380
[ 40.388245] ? team_del_slave+0x60/0x60 [team]
[ 40.388752] ? rcu_read_lock_sched_held+0x90/0xc0
[ 40.389304] ? rcu_read_lock_bh_held+0xa0/0xa0
[ 40.389819] ? lock_acquire+0x164/0x3b0
[ 40.390285] ? lockdep_rtnl_is_held+0x16/0x20
[ 40.390797] ? team_port_get_rtnl+0x90/0xe0 [team]
[ 40.391353] ? __module_text_address+0x13/0x140
[ 40.391886] ? team_set_mac_address+0x151/0x290 [team]
[ 40.392547] team_set_mac_address+0x151/0x290 [team]
[ 40.393111] dev_set_mac_address+0x1f0/0x3f0
[ ... ]
Fixes:
|
||
|---|---|---|
| Documentation | ||
| LICENSES | ||
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| 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 | ||
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.