>
> This was also reported by Dominik and is being tracked at
>
https://bugzilla.kernel.org/show_bug.cgi?id=16230
>
> On Tue, 15 Jun 2010 14:24:34 +0300
> Sergey Senozhatsky <sergey.senozhatsky@gmail.com> wrote:
>
> > Hello,
> >
> > kernel: [ 3272.351191]
> > kernel: [ 3272.351194] =================================
> > kernel: [ 3272.351199] [ INFO: inconsistent lock state ]
> > kernel: [ 3272.351204] 2.6.35-rc3-dbg-00106-ga75e02b-dirty #15
> > kernel: [ 3272.351206] ---------------------------------
> > kernel: [ 3272.351210] inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage.
> > kernel: [ 3272.351215] X/3827 [HC0[0]:SC0[0]:HE1:SE1] takes:
> > kernel: [ 3272.351218] (&(&new->fa_lock)->rlock){?.-...}, at: [<c10aefb4>] kill_fasync+0x37/0x71
> > kernel: [ 3272.351232] {IN-HARDIRQ-W} state was registered at:
> > kernel: [ 3272.351235] [<c104e95c>] __lock_acquire+0x281/0xbe1
> > kernel: [ 3272.351243] [<c104f652>] lock_acquire+0x59/0x70
> > kernel: [ 3272.351248] [<c12c6c48>] _raw_spin_lock+0x25/0x34
> > kernel: [ 3272.351255] [<c10aefb4>] kill_fasync+0x37/0x71
> > kernel: [ 3272.351261] [<fd220c81>] evdev_event+0x135/0x190 [evdev]
> > kernel: [ 3272.351275] [<c1232003>] input_pass_event+0x6f/0xae
> > kernel: [ 3272.351283] [<c1232ef5>] input_handle_event+0x38d/0x396
> > kernel: [ 3272.351288] [<c1232fbf>] input_event+0x4f/0x62
> > kernel: [ 3272.351293] [<c12368e4>] input_sync+0xe/0x11
> > kernel: [ 3272.351299] [<c1236d72>] atkbd_interrupt+0x48b/0x541
> > kernel: [ 3272.351304] [<c122ecb2>] serio_interrupt+0x35/0x68
> > kernel: [ 3272.351309] [<c122fbff>] i8042_interrupt+0x264/0x26e
> > kernel: [ 3272.351314] [<c106bb02>] handle_IRQ_event+0x1d/0x98
> > kernel: [ 3272.351321] [<c106d506>] handle_edge_irq+0xc0/0x107
> > kernel: [ 3272.351326] [<c10045ca>] handle_irq+0x1a/0x20
> > kernel: [ 3272.351332] [<c100435f>] do_IRQ+0x43/0x8d
> > kernel: [ 3272.351337] [<c1002d75>] common_interrupt+0x35/0x3c
> > kernel: [ 3272.351342] [<c124723d>] cpuidle_idle_call+0x6a/0xa0
> > kernel: [ 3272.351349] [<c100170d>] cpu_idle+0x89/0xbe
> > kernel: [ 3272.351354] [<c12b6d11>] rest_init+0xb5/0xba
> > kernel: [ 3272.351361] [<c148a7bf>] start_kernel+0x33b/0x340
> > kernel: [ 3272.351368] [<c148a0c9>] i386_start_kernel+0xc9/0xd0
> > kernel: [ 3272.351374] irq event stamp: 54104917
> > kernel: [ 3272.351377] hardirqs last enabled at (54104917): [<c12c70f2>] _raw_spin_unlock_irqrestore+0x36/0x5b
> > kernel: [ 3272.351384] hardirqs last disabled at (54104916): [<c12c6ced>] _raw_spin_lock_irqsave+0x13/0x42
> > kernel: [ 3272.351391] softirqs last enabled at (54104732): [<c1032cf2>] __do_softirq+0xfd/0x10c
> > kernel: [ 3272.351398] softirqs last disabled at (54104703): [<c1032d30>] do_softirq+0x2f/0x47
> > kernel: [ 3272.351404]
> > kernel: [ 3272.351405] other info that might help us debug this:
> > kernel: [ 3272.351409] 3 locks held by X/3827:
> > kernel: [ 3272.351412] #0: (rcu_read_lock){.+.+..}, at: [<c124fdfa>] rcu_read_lock+0x0/0x26
> > kernel: [ 3272.351423] #1: (rcu_read_lock){.+.+..}, at: [<c124d5d9>] rcu_read_lock+0x0/0x26
> > kernel: [ 3272.351432] #2: (rcu_read_lock){.+.+..}, at: [<c10ae429>] rcu_read_lock+0x0/0x26
> > kernel: [ 3272.351442]
> > kernel: [ 3272.351443] stack backtrace:
> > kernel: [ 3272.351448] Pid: 3827, comm: X Not tainted 2.6.35-rc3-dbg-00106-ga75e02b-dirty #15
> > kernel: [ 3272.351451] Call Trace:
> > kernel: [ 3272.351456] [<c12c4ff1>] ? printk+0xf/0x11
> > kernel: [ 3272.351462] [<c104e51a>] valid_state+0x133/0x141
> > kernel: [ 3272.351468] [<c104e5f7>] mark_lock+0xcf/0x1b3
> > kernel: [ 3272.351473] [<c104e54e>] ? mark_lock+0x26/0x1b3
> > kernel: [ 3272.351479] [<c104dfd2>] ? check_usage_backwards+0x0/0x68
> > kernel: [ 3272.351484] [<c104e9d0>] __lock_acquire+0x2f5/0xbe1
> > kernel: [ 3272.351489] [<c104ea44>] ? __lock_acquire+0x369/0xbe1
> > kernel: [ 3272.351495] [<c104ea44>] ? __lock_acquire+0x369/0xbe1
> > kernel: [ 3272.351502] [<c102ab40>] ? try_to_wake_up+0x2a8/0x2bb
> > kernel: [ 3272.351508] [<c104f652>] lock_acquire+0x59/0x70
> > kernel: [ 3272.351513] [<c10aefb4>] ? kill_fasync+0x37/0x71
> > kernel: [ 3272.351519] [<c12c6c48>] _raw_spin_lock+0x25/0x34
> > kernel: [ 3272.351524] [<c10aefb4>] ? kill_fasync+0x37/0x71
> > kernel: [ 3272.351529] [<c10aefb4>] kill_fasync+0x37/0x71
> > kernel: [ 3272.351534] [<c124d694>] sock_wake_async+0x77/0x83
> > kernel: [ 3272.351540] [<c124fe4d>] sk_wake_async+0x2d/0x32
> > kernel: [ 3272.351545] [<c1250004>] sock_def_readable+0x45/0x51
> > kernel: [ 3272.351551] [<c12b0247>] unix_stream_sendmsg+0x1e2/0x269
> > kernel: [ 3272.351557] [<c124fe6e>] ? rcu_read_unlock+0x1c/0x1e
> > kernel: [ 3272.351562] [<c124cf1a>] __sock_sendmsg+0x51/0x5a
> > kernel: [ 3272.351567] [<c124cff7>] sock_aio_write+0xd4/0xdd
> > kernel: [ 3272.351575] [<c10a4d95>] do_sync_readv_writev+0x84/0xb7
> > kernel: [ 3272.351582] [<c10a4288>] ? copy_from_user+0x8/0xa
> > kernel: [ 3272.351587] [<c10a4e69>] ? rw_copy_check_uvector+0x55/0xc7
> > kernel: [ 3272.351594] [<c1164082>] ? security_file_permission+0xf/0x11
> > kernel: [ 3272.351599] [<c10a47e5>] ? rw_verify_area+0x90/0xac
> > kernel: [ 3272.351605] [<c10a4f58>] do_readv_writev+0x7d/0xdf
> > kernel: [ 3272.351610] [<c124cf23>] ? sock_aio_write+0x0/0xdd
> > kernel: [ 3272.351615] [<c1164082>] ? security_file_permission+0xf/0x11
> > kernel: [ 3272.351621] [<c10a47e5>] ? rw_verify_area+0x90/0xac
> > kernel: [ 3272.351626] [<c10a4ff3>] vfs_writev+0x39/0x42
> > kernel: [ 3272.351632] [<c10a5102>] sys_writev+0x3b/0x8c
> > kernel: [ 3272.351637] [<c10027d3>] sysenter_do_call+0x12/0x32
> >
>
> This, I think?
>
>
> From: Andrew Morton <akpm@linux-foundation.org>
>
> Fix a lockdep-splat-causing regression introduced by
>
> : commit 989a2979205dd34269382b357e6d4b4b6956b889
> : Author: Eric Dumazet <eric.dumazet@gmail.com>
> : AuthorDate: Wed Apr 14 09:55:35 2010 +0000
> : Commit: David S. Miller <davem@davemloft.net>
> : CommitDate: Wed Apr 21 16:19:29 2010 -0700
> :
> : fasync: RCU and fine grained locking
>
> kill_fasync() can be called from both process and hard-irq context, so
> fa_lock must be taken with IRQs disabled.
>
> Addresses
https://bugzilla.kernel.org/show_bug.cgi?id=16230
>
> Reported-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
> Reported-by: Dominik Brodowski <linux@dominikbrodowski.net>
> Cc: Maciej Rutecki <maciej.rutecki@gmail.com>
> Cc: Eric Dumazet <eric.dumazet@gmail.com>
> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
> Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
> Cc: "David S. Miller" <davem@davemloft.net>
> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
> ---
>
> fs/fcntl.c | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff -puN fs/fcntl.c~fs-fcntlc-kill_fasync_rcu-fa_lock-must-be-irq-safe fs/fcntl.c
> --- a/fs/fcntl.c~fs-fcntlc-kill_fasync_rcu-fa_lock-must-be-irq-safe
> +++ a/fs/fcntl.c
> @@ -733,12 +733,14 @@ static void kill_fasync_rcu(struct fasyn
> {
> while (fa) {
> struct fown_struct *fown;
> + unsigned long flags;
> +
> if (fa->magic != FASYNC_MAGIC) {
> printk(KERN_ERR "kill_fasync: bad magic number in "
> "fasync_struct!\n");
> return;
> }
> - spin_lock(&fa->fa_lock);
> + spin_lock_irqsave(&fa->fa_lock, flags);
> if (fa->fa_file) {
> fown = &fa->fa_file->f_owner;
> /* Don't send SIGURG to processes which have not set a
> @@ -747,7 +749,7 @@ static void kill_fasync_rcu(struct fasyn
> if (!(sig == SIGURG && fown->signum == 0))
> send_sigio(fown, fa->fa_fd, band);
> }
> - spin_unlock(&fa->fa_lock);
> + spin_unlock_irqrestore(&fa->fa_lock, flags);
> fa = rcu_dereference(fa->fa_next);
> }
> }
> _
>
>
> afaict all other lockers of fa_lock are OK (but one never really knows
> with spin_lock_irq()).
>
> Guys, please review-and-ack and I'll get it merged up.
