On Wed, Jan 29, 2014 at 03:19:51PM -0200, Fabio Estevam wrote: > On Wed, Jan 29, 2014 at 3:04 PM, Tejun Heo <tj@xxxxxxxxxx> wrote: > > kernfs_deactivate() forgot to check whether KERNFS_LOCKDEP is set > > before performing lockdep annotations and ends up feeding > > uninitialized lockdep_map to lockdep triggering warning like the > > following on USB stick hotunplug. > > > > usb 1-2: USB disconnect, device number 2 > > INFO: trying to register non-static key. > > the code is fine but needs lockdep annotation. > > turning off the locking correctness validator. > > CPU: 1 PID: 62 Comm: khubd Not tainted 3.13.0-work+ #82 > > Hardware name: empty empty/S3992, BIOS 080011 10/26/2007 > > ffff880065ca7f60 ffff88013a4ffa08 ffffffff81cfb6bd 0000000000000002 > > ffff88013a4ffac8 ffffffff810f8530 ffff88013a4fc710 0000000000000002 > > ffff880100000000 ffffffff82a3db50 0000000000000001 ffff88013a4fc710 > > Call Trace: > > [<ffffffff81cfb6bd>] dump_stack+0x4e/0x7a > > [<ffffffff810f8530>] __lock_acquire+0x1910/0x1e70 > > [<ffffffff810f931a>] lock_acquire+0x9a/0x1d0 > > [<ffffffff8127c75e>] kernfs_deactivate+0xee/0x130 > > [<ffffffff8127d4c8>] kernfs_addrm_finish+0x38/0x60 > > [<ffffffff8127d701>] kernfs_remove_by_name_ns+0x51/0xa0 > > [<ffffffff8127b4f1>] remove_files.isra.1+0x41/0x80 > > [<ffffffff8127b7e7>] sysfs_remove_group+0x47/0xa0 > > [<ffffffff8127b873>] sysfs_remove_groups+0x33/0x50 > > [<ffffffff8177d66d>] device_remove_attrs+0x4d/0x80 > > [<ffffffff8177e25e>] device_del+0x12e/0x1d0 > > [<ffffffff819722c2>] usb_disconnect+0x122/0x1a0 > > [<ffffffff819749b5>] hub_thread+0x3c5/0x1290 > > [<ffffffff810c6a6d>] kthread+0xed/0x110 > > [<ffffffff81d0a56c>] ret_from_fork+0x7c/0xb0 > > > > Fix it by making kernfs_deactivate() perform lockdep annotations only > > if KERNFS_LOCKDEP is set. > > > > Signed-off-by: Tejun Heo <tj@xxxxxxxxxx> > > Reported-by: Fabio Estevam <festevam@xxxxxxxxx> > > Reported-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> > > Thanks, Tejun. I don't get the warning after removing the USB stick > after applying this patch: > > Tested-by: Fabio Estevam <fabio.estevam@xxxxxxxxxxxxx> Great, I'll queue this up and get it to Linus after 3.14-rc1 is out. thanks, greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
