Subject: [mac80211_hwsim] WARNING: CPU: 0 PID: 1 at include/linux/kref.h:47 kobject_get()

From: Fengguang Wu <[email-masked]>
Date: Wed, 5 Mar 2014 20:57:03 +0800

Greetings,

I got the below dmesg and the first bad commit is

commit 9ea927748ced4953f1e9a0f1fa1fdeacd1018b4e
Author:     Martin Pitt <[email-masked]>
AuthorDate: Mon Apr 8 11:30:01 2013 +0200
Commit:     Johannes Berg <[email-masked]>
CommitDate: Wed Apr 10 20:23:50 2013 +0200

    mac80211_hwsim: Register and bind to driver
    
[    3.588600] mac80211_hwsim: ieee80211_register_hw failed (-2)
[    3.590170] ------------[ cut here ]------------
[    3.590170] ------------[ cut here ]------------
[    3.591332] WARNING: CPU: 0 PID: 1 at include/linux/kref.h:47 kobject_get+0x33/0x50()
...
[    3.695323] WARNING: CPU: 0 PID: 1 at fs/kernfs/dir.c:1216 kernfs_remove_by_name_ns+0x31/0x80()
...
[    3.814723] BUG: unable to handle kernel paging requestpaging request at 883d11f0

Bisect log shows that the problems are also present in linux-next.

git bisect start v3.10 v3.9 --
git bisect  bad ff89acc563a0bd49965674f56552ad6620415fe2  # 22:47      0-      6  Merge branch 'rcu/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu
git bisect  bad 24d0c2542b38963ae4d5171ecc0a2c1326c656bc  # 22:52      0-      2  Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
git bisect good 151173e8ce9b95bbbbd7eedb9035cfaffbdb7cb2  # 23:00     23+     23  Merge tag 'for-v3.10' of git://git.infradead.org/battery-2.6
git bisect  bad e95893004104054d49406fd108fefa3ddc054366  # 23:03      0-      1  Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost
git bisect good 8a72f3820c4d14b27ad5336aed00063a7a7f1bef  # 23:09     23+     23  Merge git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile
git bisect  bad 600fe9751aeb6f6b72de84076a05c5b8c04152c0  # 23:12      0-      3  ipc_schedule_free() can do vfree() directly now
git bisect  bad 126de6b20bfb82cc19012d5048f11f339ae5a021  # 23:16      0-      3  linkage.h: fix build breakage due to symbol prefix handling
git bisect good 251df49db3327c64bf917bfdba94491fde2b4ee0  # 23:22     23+     23  Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
git bisect  bad 73287a43cc79ca06629a88d1a199cd283f42456a  # 23:25      0-      1  Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next
git bisect good 953c96e0d85615d1ab1f100e525d376053294dc2  # 23:37     23+      0  tg3: Use bool not int
git bisect  bad 4fc4118cdb29ab946b8a586fc766ebb6ae1e1c90  # 23:42      0-      7  wil6210: more Rx descriptor accessor functions
git bisect good e73dcfbf061b524fe9aaef56cf3c2e234a45ec19  # 23:52     23+      0  Bluetooth: hidp: fix sending output reports on intr channel
git bisect good d5590bba37f3c7d496195648532d5313abb43891  # 23:58     23+      0  NFC: pn533: Re-group fields in struct pn533
git bisect  bad 06d961a8e210035bff7e82f466107f9ab4a8fd94  # 00:07      0-     16  mac80211/minstrel: use the new rate control API
git bisect  bad 97990a060e6757f48b931a3946b17c1c4362c3fb  # 00:11      0-      4  nl80211: allow using wdev identifiers to get scan results
git bisect  bad 85220d71bf3ca1ba9129e0744247ae5f61bec559  # 00:12      0-      1  mac80211: support secondary channel offset in CSA
git bisect  bad 0ca54f6c5fd4ce58aa044d1fc7f00d7f6cf2801c  # 00:14      0-      1  mac80211: provide SSID in IBSS mode
git bisect  bad 3088f7d2db42925808c4b43a6258647ee4d1dd5f  # 00:15      0-      2  mac80211: stringify another plink state
git bisect  bad 9d6d6f4924133567a108a862d9cf949cd03f71cb  # 00:17      0-      1  mac80211: unset FC retry bit in mesh fwding path
git bisect  bad 9ea927748ced4953f1e9a0f1fa1fdeacd1018b4e  # 00:21      0-      2  mac80211_hwsim: Register and bind to driver
# first bad commit: [9ea927748ced4953f1e9a0f1fa1fdeacd1018b4e] mac80211_hwsim: Register and bind to driver
git bisect good ddc4db2e3d5393ede7a9222bb3b7522a603a4678  # 00:35     69+      0  mac80211: make ieee802_11_parse_elems an inline
git bisect  bad faa2e6fb0a98c9caa8995acf3222db9f7f029395  # 00:35      0-     19  Add linux-next specific files for 20140221
git bisect  bad 8427defd087ae6c5eaea9d609dfe7f165568accd  # 00:38      0-      2  MAINTAINERS: add maintainer entry for Armada DRM driver
git bisect  bad b148a42ba7823e34971cd4e5b05a5c74fa3311ed  # 00:41      0-      2  Add linux-next specific files for 20140228

Thanks,
Fengguang