Return-path: Received: from mga01.intel.com ([192.55.52.88]:25352 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751899AbZBLTHT (ORCPT ); Thu, 12 Feb 2009 14:07:19 -0500 Subject: possible circular locking triggered from iw From: reinette chatre To: johannes@sipsolutions.net Cc: linux-wireless@vger.kernel.org Content-Type: text/plain Date: Thu, 12 Feb 2009 11:11:10 -0800 Message-Id: <1234465870.30608.20.camel@rc-desk> (sfid-20090212_200727_602309_F0E5BB47) Mime-Version: 1.0 Sender: linux-wireless-owner@vger.kernel.org List-ID: Running "iw dev wlan0 scan trigger" resulted in the message below. This is on the latest wireless-testing and iw. It only happened the first time I triggered the scan. [ 450.148335] ======================================================= [ 450.148453] [ INFO: possible circular locking dependency detected ] [ 450.148521] 2.6.29-rc4-wl #22 [ 450.148586] ------------------------------------------------------- [ 450.148651] iw/6265 is trying to acquire lock: [ 450.148711] (rtnl_mutex){--..}, at: [] rtnl_lock+0x12/0x20 [ 450.148898] [ 450.148899] but task is already holding lock: [ 450.149008] (&drv->mtx){--..}, at: [] cfg80211_get_dev_from_ifindex+0x5b/0x80 [cfg80211] [ 450.149221] [ 450.149222] which lock already depends on the new lock. [ 450.149224] [ 450.149384] [ 450.149385] the existing dependency chain (in reverse order) is: [ 450.149498] [ 450.149499] -> #2 (&drv->mtx){--..}: [ 450.149717] [] validate_chain+0xc1f/0x1270 [ 450.149825] [] __lock_acquire+0x31e/0xa30 [ 450.149929] [] lock_acquire+0x58/0x80 [ 450.150032] [] mutex_lock_nested+0x9d/0x2f0 [ 450.150138] [] cfg80211_get_dev_from_ifindex+0x5b/0x80 [cfg80211] [ 450.150265] [] cfg80211_wext_siwscan+0x58/0x210 [cfg80211] [ 450.150392] [] ioctl_standard_call+0x1a3/0x390 [ 450.150498] [] wext_handle_ioctl+0xf1/0x220 [ 450.150602] [] dev_ioctl+0x559/0x5b0 [ 450.150706] [] sock_ioctl+0xe5/0x260 [ 450.150810] [] vfs_ioctl+0x31/0x90 [ 450.150913] [] do_vfs_ioctl+0x330/0x540 [ 450.151015] [] sys_ioctl+0x82/0xa0 [ 450.151117] [] system_call_fastpath+0x16/0x1b [ 450.151223] [] 0xffffffffffffffff [ 450.151330] [ 450.151332] -> #1 (cfg80211_drv_mutex){--..}: [ 450.151551] [] validate_chain+0xc1f/0x1270 [ 450.151656] [] __lock_acquire+0x31e/0xa30 [ 450.151759] [] lock_acquire+0x58/0x80 [ 450.151861] [] mutex_lock_nested+0x9d/0x2f0 [ 450.151965] [] cfg80211_get_dev_from_ifindex+0x1e/0x80 [cfg80211] [ 450.152010] [] cfg80211_wext_siwscan+0x58/0x210 [cfg80211] [ 450.152010] [] ioctl_standard_call+0x1a3/0x390 [ 450.152010] [] wext_handle_ioctl+0xf1/0x220 [ 450.152010] [] dev_ioctl+0x559/0x5b0 [ 450.152010] [] sock_ioctl+0xe5/0x260 [ 450.152010] [] vfs_ioctl+0x31/0x90 [ 450.152010] [] do_vfs_ioctl+0x330/0x540 [ 450.152010] [] sys_ioctl+0x82/0xa0 [ 450.152010] [] system_call_fastpath+0x16/0x1b [ 450.152010] [] 0xffffffffffffffff [ 450.152010] [ 450.152010] -> #0 (rtnl_mutex){--..}: [ 450.152010] [] validate_chain+0x7d0/0x1270 [ 450.152010] [] __lock_acquire+0x31e/0xa30 [ 450.152010] [] lock_acquire+0x58/0x80 [ 450.152010] [] mutex_lock_nested+0x9d/0x2f0 [ 450.152010] [] rtnl_lock+0x12/0x20 [ 450.152010] [] nl80211_trigger_scan+0x52/0x490 [cfg80211] [ 450.152010] [] genl_rcv_msg+0x181/0x1c0 [ 450.152010] [] netlink_rcv_skb+0x89/0xb0 [ 450.152010] [] genl_rcv+0x29/0x40 [ 450.152010] [] netlink_unicast+0x27f/0x2c0 [ 450.152010] [] netlink_sendmsg+0x231/0x2e0 [ 450.152010] [] sock_sendmsg+0x127/0x140 [ 450.152010] [] sys_sendmsg+0x142/0x260 [ 450.152010] [] system_call_fastpath+0x16/0x1b [ 450.152010] [] 0xffffffffffffffff [ 450.152010] [ 450.152010] other info that might help us debug this: [ 450.152010] [ 450.152010] 2 locks held by iw/6265: [ 450.152010] #0: (genl_mutex){--..}, at: [] genl_rcv+0x1a/0x40 [ 450.152010] #1: (&drv->mtx){--..}, at: [] cfg80211_get_dev_from_ifindex+0x5b/0x80 [cfg80211] [ 450.152010] [ 450.152010] stack backtrace: [ 450.152010] Pid: 6265, comm: iw Not tainted 2.6.29-rc4-wl #22 [ 450.152010] Call Trace: [ 450.152010] [] print_circular_bug_tail+0x95/0xe0 [ 450.152010] [] validate_chain+0x7d0/0x1270 [ 450.152010] [] ? __lock_acquire+0x31e/0xa30 [ 450.152010] [] __lock_acquire+0x31e/0xa30 [ 450.152010] [] ? rtnl_lock+0x12/0x20 [ 450.152010] [] lock_acquire+0x58/0x80 [ 450.152010] [] ? rtnl_lock+0x12/0x20 [ 450.152010] [] mutex_lock_nested+0x9d/0x2f0 [ 450.152010] [] ? rtnl_lock+0x12/0x20 [ 450.152010] [] ? cfg80211_get_dev_from_ifindex+0x6e/0x80 [cfg80211] [ 450.152010] [] rtnl_lock+0x12/0x20 [ 450.152010] [] nl80211_trigger_scan+0x52/0x490 [cfg80211] [ 450.152010] [] genl_rcv_msg+0x181/0x1c0 [ 450.152010] [] ? genl_rcv_msg+0x0/0x1c0 [ 450.152010] [] netlink_rcv_skb+0x89/0xb0 [ 450.152010] [] genl_rcv+0x29/0x40 [ 450.152010] [] ? netlink_unicast+0xe8/0x2c0 [ 450.152010] [] netlink_unicast+0x27f/0x2c0 [ 450.152010] [] ? __alloc_skb+0x89/0x140 [ 450.152010] [] netlink_sendmsg+0x231/0x2e0 [ 450.152010] [] sock_sendmsg+0x127/0x140 [ 450.152010] [] ? autoremove_wake_function+0x0/0x40 [ 450.152010] [] ? get_page_from_freelist+0x485/0x590 [ 450.152010] [] ? trace_hardirqs_on_caller+0x15a/0x1b0 [ 450.152010] [] ? trace_hardirqs_on+0xd/0x10 [ 450.152010] [] ? get_page_from_freelist+0x3a8/0x590 [ 450.152010] [] ? move_addr_to_kernel+0x57/0x60 [ 450.152010] [] ? verify_iovec+0x3c/0xc0 [ 450.152010] [] sys_sendmsg+0x142/0x260 [ 450.152010] [] ? _spin_unlock_irqrestore+0x55/0x60 [ 450.152010] [] ? trace_hardirqs_on_caller+0x15a/0x1b0 [ 450.152010] [] ? trace_hardirqs_on+0xd/0x10 [ 450.152010] [] ? __up_read+0x46/0xb0 [ 450.152010] [] ? up_read+0x26/0x30 [ 450.152010] [] ? trace_hardirqs_on_caller+0x15a/0x1b0 [ 450.152010] [] ? trace_hardirqs_on_thunk+0x3a/0x3f [ 450.152010] [] system_call_fastpath+0x16/0x1b