v2.6.28-rc1: possible recursive locking detected

v2.6.28-rc1: possible recursive locking detected

[Vegard Nossum]

Hi,

I think that this wasn't my fault. It's v2.6.28-rc1+kmemcheck.

=============================================
[ INFO: possible recursive locking detected ]
2.6.28-rc1 #58
---------------------------------------------
cat/25690 is trying to acquire lock:
 (&hashbin->hb_spinlock){....}, at: [<c1780e1f>] irias_seq_show+0x3f/0x180

but task is already holding lock:
 (&hashbin->hb_spinlock){....}, at: [<c1780f95>] irias_seq_start+0x15/0x90

other info that might help us debug this:
2 locks held by cat/25690:
 #0:  (&p->lock){--..}, at: [<c0502545>] seq_read+0x25/0x2e0
 #1:  (&hashbin->hb_spinlock){....}, at: [<c1780f95>] irias_seq_start+0x15/0x90

stack backtrace:
Pid: 25690, comm: cat Not tainted 2.6.28-rc1 #58
Call Trace:
 [<c195b5d6>] ? printk+0x18/0x1a
 [<c048a0bb>] __lock_acquire+0xf0b/0xf80
 [<c044c8da>] ? kmemcheck_hide_addr+0x4a/0x60
 [<c042529b>] ? do_debug+0x3b/0x1b0
 [<c048a1a1>] lock_acquire+0x71/0xa0
 [<c1780e1f>] ? irias_seq_show+0x3f/0x180
 [<c195e636>] _spin_lock+0x36/0x60
 [<c1780e1f>] ? irias_seq_show+0x3f/0x180
 [<c1780e1f>] irias_seq_show+0x3f/0x180
 [<c050270c>] seq_read+0x1ec/0x2e0
 [<c0502520>] ? seq_read+0x0/0x2e0
 [<c05297ed>] proc_reg_read+0x5d/0x90
 [<c04ea749>] vfs_read+0x99/0x160
 [<c0529790>] ? proc_reg_read+0x0/0x90
 [<c04ea8cd>] sys_read+0x3d/0x70
 [<c0422f83>] sysenter_do_call+0x12/0x3f
 [<c0420000>] ? svm_intr_assist+0x90/0x1a0


Vegard

-- 
"The animistic metaphor of the bug that maliciously sneaked in while
the programmer was not looking is intellectually dishonest as it
disguises that the error is the programmer's own creation."
	-- E. W. Dijkstra, EWD1036

Re: v2.6.28-rc1: possible recursive locking detected

[Rafael J. Wysocki]

On Sunday, 26 of October 2008, Vegard Nossum wrote:
> Hi,
> 
> I think that this wasn't my fault. It's v2.6.28-rc1+kmemcheck.

Is this reproducible on -rc2?

Rafael


> =============================================
> [ INFO: possible recursive locking detected ]
> 2.6.28-rc1 #58
> ---------------------------------------------
> cat/25690 is trying to acquire lock:
>  (&hashbin->hb_spinlock){....}, at: [<c1780e1f>] irias_seq_show+0x3f/0x180
> 
> but task is already holding lock:
>  (&hashbin->hb_spinlock){....}, at: [<c1780f95>] irias_seq_start+0x15/0x90
> 
> other info that might help us debug this:
> 2 locks held by cat/25690:
>  #0:  (&p->lock){--..}, at: [<c0502545>] seq_read+0x25/0x2e0
>  #1:  (&hashbin->hb_spinlock){....}, at: [<c1780f95>] irias_seq_start+0x15/0x90
> 
> stack backtrace:
> Pid: 25690, comm: cat Not tainted 2.6.28-rc1 #58
> Call Trace:
>  [<c195b5d6>] ? printk+0x18/0x1a
>  [<c048a0bb>] __lock_acquire+0xf0b/0xf80
>  [<c044c8da>] ? kmemcheck_hide_addr+0x4a/0x60
>  [<c042529b>] ? do_debug+0x3b/0x1b0
>  [<c048a1a1>] lock_acquire+0x71/0xa0
>  [<c1780e1f>] ? irias_seq_show+0x3f/0x180
>  [<c195e636>] _spin_lock+0x36/0x60
>  [<c1780e1f>] ? irias_seq_show+0x3f/0x180
>  [<c1780e1f>] irias_seq_show+0x3f/0x180
>  [<c050270c>] seq_read+0x1ec/0x2e0
>  [<c0502520>] ? seq_read+0x0/0x2e0
>  [<c05297ed>] proc_reg_read+0x5d/0x90
>  [<c04ea749>] vfs_read+0x99/0x160
>  [<c0529790>] ? proc_reg_read+0x0/0x90
>  [<c04ea8cd>] sys_read+0x3d/0x70
>  [<c0422f83>] sysenter_do_call+0x12/0x3f
>  [<c0420000>] ? svm_intr_assist+0x90/0x1a0
> 
> 
> Vegard
>