* [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 related [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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