Eliad Peller fe20b39ec3 cfg80211: fix potential deadlock in regulatory ... reg_timeout_work() calls restore_regulatory_settings() which takes cfg80211_mutex. reg_set_request_processed() already holds cfg80211_mutex before calling cancel_delayed_work_sync(reg_timeout), so it might deadlock. Call the async cancel_delayed_work instead, in order to avoid the potential deadlock. This is the relevant lockdep warning: cfg80211: Calling CRDA for country: XX ====================================================== [ INFO: possible circular locking dependency detected ] 3.4.0-rc5-wl+ #26 Not tainted ------------------------------------------------------- kworker/0:2/1391 is trying to acquire lock: (cfg80211_mutex){+.+.+.}, at: [<bf28ae00>] restore_regulatory_settings+0x34/0x418 [cfg80211] but task is already holding lock: ((reg_timeout).work){+.+...}, at: [<c0059e94>] process_one_work+0x1f0/0x480 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 ((reg_timeout).work){+.+...}: [<c008fd44>] validate_chain+0xb94/0x10f0 [<c0090b68>] __lock_acquire+0x8c8/0x9b0 [<c0090d40>] lock_acquire+0xf0/0x114 [<c005b600>] wait_on_work+0x4c/0x154 [<c005c000>] __cancel_work_timer+0xd4/0x11c [<c005c064>] cancel_delayed_work_sync+0x1c/0x20 [<bf28b274>] reg_set_request_processed+0x50/0x78 [cfg80211] [<bf28bd84>] set_regdom+0x550/0x600 [cfg80211] [<bf294cd8>] nl80211_set_reg+0x218/0x258 [cfg80211] [<c03c7738>] genl_rcv_msg+0x1a8/0x1e8 [<c03c6a00>] netlink_rcv_skb+0x5c/0xc0 [<c03c7584>] genl_rcv+0x28/0x34 [<c03c6720>] netlink_unicast+0x15c/0x228 [<c03c6c7c>] netlink_sendmsg+0x218/0x298 [<c03933c8>] sock_sendmsg+0xa4/0xc0 [<c039406c>] __sys_sendmsg+0x1e4/0x268 [<c0394228>] sys_sendmsg+0x4c/0x70 [<c0013840>] ret_fast_syscall+0x0/0x3c -> #1 (reg_mutex){+.+.+.}: [<c008fd44>] validate_chain+0xb94/0x10f0 [<c0090b68>] __lock_acquire+0x8c8/0x9b0 [<c0090d40>] lock_acquire+0xf0/0x114 [<c04734dc>] mutex_lock_nested+0x48/0x320 [<bf28b2cc>] reg_todo+0x30/0x538 [cfg80211] [<c0059f44>] process_one_work+0x2a0/0x480 [<c005a4b4>] worker_thread+0x1bc/0x2bc [<c0061148>] kthread+0x98/0xa4 [<c0014af4>] kernel_thread_exit+0x0/0x8 -> #0 (cfg80211_mutex){+.+.+.}: [<c008ed58>] print_circular_bug+0x68/0x2cc [<c008fb28>] validate_chain+0x978/0x10f0 [<c0090b68>] __lock_acquire+0x8c8/0x9b0 [<c0090d40>] lock_acquire+0xf0/0x114 [<c04734dc>] mutex_lock_nested+0x48/0x320 [<bf28ae00>] restore_regulatory_settings+0x34/0x418 [cfg80211] [<bf28b200>] reg_timeout_work+0x1c/0x20 [cfg80211] [<c0059f44>] process_one_work+0x2a0/0x480 [<c005a4b4>] worker_thread+0x1bc/0x2bc [<c0061148>] kthread+0x98/0xa4 [<c0014af4>] kernel_thread_exit+0x0/0x8 other info that might help us debug this: Chain exists of: cfg80211_mutex --> reg_mutex --> (reg_timeout).work Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock((reg_timeout).work); lock(reg_mutex); lock((reg_timeout).work); lock(cfg80211_mutex); *** DEADLOCK *** 2 locks held by kworker/0:2/1391: #0: (events){.+.+.+}, at: [<c0059e94>] process_one_work+0x1f0/0x480 #1: ((reg_timeout).work){+.+...}, at: [<c0059e94>] process_one_work+0x1f0/0x480 stack backtrace: [<c001b928>] (unwind_backtrace+0x0/0x12c) from [<c0471d3c>] (dump_stack+0x20/0x24) [<c0471d3c>] (dump_stack+0x20/0x24) from [<c008ef70>] (print_circular_bug+0x280/0x2cc) [<c008ef70>] (print_circular_bug+0x280/0x2cc) from [<c008fb28>] (validate_chain+0x978/0x10f0) [<c008fb28>] (validate_chain+0x978/0x10f0) from [<c0090b68>] (__lock_acquire+0x8c8/0x9b0) [<c0090b68>] (__lock_acquire+0x8c8/0x9b0) from [<c0090d40>] (lock_acquire+0xf0/0x114) [<c0090d40>] (lock_acquire+0xf0/0x114) from [<c04734dc>] (mutex_lock_nested+0x48/0x320) [<c04734dc>] (mutex_lock_nested+0x48/0x320) from [<bf28ae00>] (restore_regulatory_settings+0x34/0x418 [cfg80211]) [<bf28ae00>] (restore_regulatory_settings+0x34/0x418 [cfg80211]) from [<bf28b200>] (reg_timeout_work+0x1c/0x20 [cfg80211]) [<bf28b200>] (reg_timeout_work+0x1c/0x20 [cfg80211]) from [<c0059f44>] (process_one_work+0x2a0/0x480) [<c0059f44>] (process_one_work+0x2a0/0x480) from [<c005a4b4>] (worker_thread+0x1bc/0x2bc) [<c005a4b4>] (worker_thread+0x1bc/0x2bc) from [<c0061148>] (kthread+0x98/0xa4) [<c0061148>] (kthread+0x98/0xa4) from [<c0014af4>] (kernel_thread_exit+0x0/0x8) cfg80211: Calling CRDA to update world regulatory domain cfg80211: World regulatory domain updated: cfg80211: (start_freq - end_freq @ bandwidth), (max_antenna_gain, max_eirp) cfg80211: (2402000 KHz - 2472000 KHz @ 40000 KHz), (300 mBi, 2000 mBm) cfg80211: (2457000 KHz - 2482000 KHz @ 20000 KHz), (300 mBi, 2000 mBm) cfg80211: (2474000 KHz - 2494000 KHz @ 20000 KHz), (300 mBi, 2000 mBm) cfg80211: (5170000 KHz - 5250000 KHz @ 40000 KHz), (300 mBi, 2000 mBm) cfg80211: (5735000 KHz - 5835000 KHz @ 40000 KHz), (300 mBi, 2000 mBm) Cc: stable@kernel.org Signed-off-by: Eliad Peller <eliad@wizery.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com>		2012-06-13 10:17:53 +02:00
..
.gitignore
chan.c
core.c
core.h
db.txt
debugfs.c
debugfs.h
ethtool.c
ethtool.h
genregdb.awk
ibss.c
Kconfig
lib80211_crypt_ccmp.c
lib80211_crypt_tkip.c
lib80211_crypt_wep.c
lib80211.c
Makefile
mesh.c
mlme.c
nl80211.c
nl80211.h
radiotap.c
reg.c
reg.h
regdb.h
scan.c
sme.c
sysfs.c
sysfs.h
util.c
wext-compat.c
wext-compat.h
wext-core.c
wext-priv.c
wext-proc.c
wext-sme.c
wext-spy.c