mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-09-15 23:25:07 +00:00
bc43b28c10
Luis reported this lockdep complaint, that he had also reported earlier but when trying to analyse I had been locking at the wrong code, and never saw the problem: (slightly abridged) ======================================================= [ INFO: possible circular locking dependency detected ] 2.6.31-rc4-wl #6 ------------------------------------------------------- wpa_supplicant/3799 is trying to acquire lock: (cfg80211_mutex){+.+.+.}, at: [<ffffffffa009246a>] cfg80211_get_dev_from_ifindex+0x1a/0x90 [cfg80211] but task is already holding lock: (rtnl_mutex){+.+.+.}, at: [<ffffffff81400ff2>] rtnl_lock+0x12/0x20 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (rtnl_mutex){+.+.+.}: [<ffffffff810857b6>] __lock_acquire+0xd76/0x12b0 [<ffffffff81085dd3>] lock_acquire+0xe3/0x120 [<ffffffff814ee7a4>] mutex_lock_nested+0x44/0x350 [<ffffffff81400ff2>] rtnl_lock+0x12/0x20 [<ffffffffa009f6a5>] nl80211_send_reg_change_event+0x1f5/0x2a0 [cfg80211] [<ffffffffa009529e>] set_regdom+0x28e/0x4c0 [cfg80211] -> #0 (cfg80211_mutex){+.+.+.}: [<ffffffff8108587b>] __lock_acquire+0xe3b/0x12b0 [<ffffffff81085dd3>] lock_acquire+0xe3/0x120 [<ffffffff814ee7a4>] mutex_lock_nested+0x44/0x350 [<ffffffffa009246a>] cfg80211_get_dev_from_ifindex+0x1a/0x90 [cfg80211] [<ffffffffa009813f>] get_rdev_dev_by_info_ifindex+0x6f/0xa0 [cfg80211] [<ffffffffa009b12b>] nl80211_set_interface+0x3b/0x260 [cfg80211] When looking at the correct code, the problem is quite obvious. I'm not entirely sure which code paths lead here, so until I can analyse it better let's just use RCU to avoid the problem. Signed-off-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: John W. Linville <linville@tuxdriver.com> |
||
|---|---|---|
| .. | ||
| core.c | ||
| core.h | ||
| debugfs.c | ||
| debugfs.h | ||
| ibss.c | ||
| Kconfig | ||
| lib80211.c | ||
| lib80211_crypt_ccmp.c | ||
| lib80211_crypt_tkip.c | ||
| lib80211_crypt_wep.c | ||
| Makefile | ||
| mlme.c | ||
| nl80211.c | ||
| nl80211.h | ||
| radiotap.c | ||
| reg.c | ||
| reg.h | ||
| scan.c | ||
| sme.c | ||
| sysfs.c | ||
| sysfs.h | ||
| util.c | ||
| wext-compat.c | ||
| wext-sme.c | ||
| wext.c | ||