* [PATCH driver-core-linus] kernfs: make kernfs_deactivate() honor KERNFS_LOCKDEP flag [not found] ` <Pine.LNX.4.44L0.1401291134070.11997-100000@netrider.rowland.org> @ 2014-01-29 17:04 ` Tejun Heo 2014-01-29 17:19 ` Fabio Estevam 2014-01-30 10:42 ` Jiri Kosina 0 siblings, 2 replies; 4+ messages in thread From: Tejun Heo @ 2014-01-29 17:04 UTC (permalink / raw) To: Greg Kroah-Hartman, Fabio Estevam, Alan Stern Cc: Denis Kirjanov, linux-kernel, USB list 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@kernel.org> Reported-by: Fabio Estevam <festevam@gmail.com> Reported-by: Alan Stern <stern@rowland.harvard.edu> --- fs/kernfs/dir.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/fs/kernfs/dir.c b/fs/kernfs/dir.c index 5104cf5..bd6e18b 100644 --- a/fs/kernfs/dir.c +++ b/fs/kernfs/dir.c @@ -187,19 +187,23 @@ static void kernfs_deactivate(struct kernfs_node *kn) kn->u.completion = (void *)&wait; - rwsem_acquire(&kn->dep_map, 0, 0, _RET_IP_); + if (kn->flags & KERNFS_LOCKDEP) + rwsem_acquire(&kn->dep_map, 0, 0, _RET_IP_); /* atomic_add_return() is a mb(), put_active() will always see * the updated kn->u.completion. */ v = atomic_add_return(KN_DEACTIVATED_BIAS, &kn->active); if (v != KN_DEACTIVATED_BIAS) { - lock_contended(&kn->dep_map, _RET_IP_); + if (kn->flags & KERNFS_LOCKDEP) + lock_contended(&kn->dep_map, _RET_IP_); wait_for_completion(&wait); } - lock_acquired(&kn->dep_map, _RET_IP_); - rwsem_release(&kn->dep_map, 1, _RET_IP_); + if (kn->flags & KERNFS_LOCKDEP) { + lock_acquired(&kn->dep_map, _RET_IP_); + rwsem_release(&kn->dep_map, 1, _RET_IP_); + } } /** ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH driver-core-linus] kernfs: make kernfs_deactivate() honor KERNFS_LOCKDEP flag 2014-01-29 17:04 ` [PATCH driver-core-linus] kernfs: make kernfs_deactivate() honor KERNFS_LOCKDEP flag Tejun Heo @ 2014-01-29 17:19 ` Fabio Estevam 2014-01-29 21:21 ` Greg Kroah-Hartman 2014-01-30 10:42 ` Jiri Kosina 1 sibling, 1 reply; 4+ messages in thread From: Fabio Estevam @ 2014-01-29 17:19 UTC (permalink / raw) To: Tejun Heo Cc: Greg Kroah-Hartman, Alan Stern, Denis Kirjanov, linux-kernel, USB list On Wed, Jan 29, 2014 at 3:04 PM, Tejun Heo <tj@kernel.org> 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@kernel.org> > Reported-by: Fabio Estevam <festevam@gmail.com> > Reported-by: Alan Stern <stern@rowland.harvard.edu> Thanks, Tejun. I don't get the warning after removing the USB stick after applying this patch: Tested-by: Fabio Estevam <fabio.estevam@freescale.com> ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH driver-core-linus] kernfs: make kernfs_deactivate() honor KERNFS_LOCKDEP flag 2014-01-29 17:19 ` Fabio Estevam @ 2014-01-29 21:21 ` Greg Kroah-Hartman 0 siblings, 0 replies; 4+ messages in thread From: Greg Kroah-Hartman @ 2014-01-29 21:21 UTC (permalink / raw) To: Fabio Estevam Cc: Tejun Heo, Alan Stern, Denis Kirjanov, linux-kernel, USB list 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@kernel.org> 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@kernel.org> > > Reported-by: Fabio Estevam <festevam@gmail.com> > > Reported-by: Alan Stern <stern@rowland.harvard.edu> > > Thanks, Tejun. I don't get the warning after removing the USB stick > after applying this patch: > > Tested-by: Fabio Estevam <fabio.estevam@freescale.com> Great, I'll queue this up and get it to Linus after 3.14-rc1 is out. thanks, greg k-h ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH driver-core-linus] kernfs: make kernfs_deactivate() honor KERNFS_LOCKDEP flag 2014-01-29 17:04 ` [PATCH driver-core-linus] kernfs: make kernfs_deactivate() honor KERNFS_LOCKDEP flag Tejun Heo 2014-01-29 17:19 ` Fabio Estevam @ 2014-01-30 10:42 ` Jiri Kosina 1 sibling, 0 replies; 4+ messages in thread From: Jiri Kosina @ 2014-01-30 10:42 UTC (permalink / raw) To: Tejun Heo Cc: Greg Kroah-Hartman, Fabio Estevam, Alan Stern, Denis Kirjanov, linux-kernel, USB list On Wed, 29 Jan 2014, Tejun Heo 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@kernel.org> > Reported-by: Fabio Estevam <festevam@gmail.com> > Reported-by: Alan Stern <stern@rowland.harvard.edu> I reported it here: https://lkml.org/lkml/2014/1/22/217 The patch fixes it for me as well. Reported-and-tested-by: Jiri Kosina <jkosina@suse.cz> Thanks, -- Jiri Kosina SUSE Labs ^ permalink raw reply [flat|nested] 4+ messages in thread
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[not found] ` <Pine.LNX.4.44L0.1401291134070.11997-100000@netrider.rowland.org>
2014-01-29 17:04 ` [PATCH driver-core-linus] kernfs: make kernfs_deactivate() honor KERNFS_LOCKDEP flag Tejun Heo
2014-01-29 17:19 ` Fabio Estevam
2014-01-29 21:21 ` Greg Kroah-Hartman
2014-01-30 10:42 ` Jiri Kosina
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