The patch titled
irda lockdep fix
has been added to the -mm tree. Its filename is
irda-lockdep-fix.patch
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: irda lockdep fix
From: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
On Sat, 2006-11-18 at 16:12 +0300, Andrey Borzenkov wrote:
> =============================================
> [ INFO: possible recursive locking detected ]
> 2.6.19-rc5-2avb #2
> - ---------------------------------------------
> pppd/26425 is trying to acquire lock:
> (&hashbin->hb_spinlock){....}, at: [<dfdea87a>] irlmp_slsap_inuse+0x5a/0x170
> [irda]
>
> but task is already holding lock:
> (&hashbin->hb_spinlock){....}, at: [<dfdea857>] irlmp_slsap_inuse+0x37/0x170
> [irda]
>
> other info that might help us debug this:
> 1 lock held by pppd/26425:
> #0: (&hashbin->hb_spinlock){....}, at: [<dfdea857>]
> irlmp_slsap_inuse+0x37/0x170 [irda]
>
> stack backtrace:
> [<c010413c>] dump_trace+0x1cc/0x200
> [<c010418a>] show_trace_log_lvl+0x1a/0x30
> [<c01047f2>] show_trace+0x12/0x20
> [<c01048c9>] dump_stack+0x19/0x20
> [<c01346ca>] __lock_acquire+0x8fa/0xc20
> [<c0134d2d>] lock_acquire+0x5d/0x80
> [<c02a851c>] _spin_lock+0x2c/0x40
> [<dfdea87a>] irlmp_slsap_inuse+0x5a/0x170 [irda]
> [<dfdebab2>] irlmp_open_lsap+0x62/0x180 [irda]
> [<dfdf35d1>] irttp_open_tsap+0x181/0x230 [irda]
> [<dfdc0c3d>] ircomm_open_tsap+0x5d/0xa0 [ircomm]
> [<dfdc05d8>] ircomm_open+0xb8/0xd0 [ircomm]
> [<dfdd0477>] ircomm_tty_open+0x4f7/0x570 [ircomm_tty]
> [<c020bbe4>] tty_open+0x174/0x340
> [<c016bd69>] chrdev_open+0x89/0x170
> [<c0167bd6>] __dentry_open+0xa6/0x1d0
> [<c0167da5>] nameidata_to_filp+0x35/0x40
> [<c0167df9>] do_filp_open+0x49/0x50
> [<c0167e47>] do_sys_open+0x47/0xd0
> [<c0167f0c>] sys_open+0x1c/0x20
> [<c010307d>] sysenter_past_esp+0x56/0x8d
> [<b7f86410>] 0xb7f86410
> =======================
The comment at the nesting lock says:
/* Careful for priority inversions here !
* irlmp->links is never taken while another IrDA
* spinlock is held, so we are safe. Jean II */
So, under the assumption the author was right, it just needs a lockdep
annotation.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Acked-by: Ingo Molnar <mingo@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
net/irda/irlmp.c | 2 +-
1 files changed, 1 insertion(+), 1 deletion(-)
diff -puN net/irda/irlmp.c~irda-lockdep-fix net/irda/irlmp.c
--- a/net/irda/irlmp.c~irda-lockdep-fix
+++ a/net/irda/irlmp.c
@@ -1678,7 +1678,7 @@ static int irlmp_slsap_inuse(__u8 slsap_
* every IrLAP connection and check every LSAP associated with each
* the connection.
*/
- spin_lock_irqsave(&irlmp->links->hb_spinlock, flags);
+ spin_lock_irqsave_nested(&irlmp->links->hb_spinlock, flags, 1);
lap = (struct lap_cb *) hashbin_get_first(irlmp->links);
while (lap != NULL) {
IRDA_ASSERT(lap->magic == LMP_LAP_MAGIC, goto errlap;);
_
Patches currently in -mm which might be from a.p.zijlstra@xxxxxxxxx are
git-net.patch
grab-swap-token-reordered.patch
new-scheme-to-preempt-swap-token.patch
new-scheme-to-preempt-swap-token-tidy.patch
mm-arch-do_page_fault-vs-in_atomic.patch
mm-pagefault_disableenable.patch
mm-pagefault_disableenable-s390-fix.patch
mm-kummap_atomic-vs-in_atomic.patch
mm-call-into-direct-reclaim-without-pf_memalloc-set.patch
mm-cleanup-and-document-reclaim-recursion.patch
lockdep-annotate-nfs-nfsd-in-kernel-sockets.patch
lockdep-annotate-nfs-nfsd-in-kernel-sockets-tidy.patch
lockdep-fix-ide-proc-interaction.patch
lockdep-spin_lock_irqsave_nested.patch
lockdep-spin_lock_irqsave_nested-fix.patch
lockdep-spin_lock_irqsave_nested-fix-2.patch
lockdep-annotate-bcsp-driver.patch
lockdep-print-current-locks-on-in_atomic-warnings.patch
lockdep-name-some-old-style-locks.patch
debug-workqueue-locking-sanity.patch
debug-workqueue-locking-sanity-fix.patch
irda-lockdep-fix.patch
tty-signal-tty-locking.patch
tty-signal-tty-locking-3270-fix.patch
do_task_stat-dont-take-tty_mutex.patch
do_acct_process-dont-take-tty_mutex.patch
sys_unshare-remove-a-broken-clone_sighand-code.patch
remove-the-old-bd_mutex-lockdep-annotation.patch
new-bd_mutex-lockdep-annotation.patch
remove-lock_key-approach-to-managing-nested-bd_mutex-locks.patch
simplify-some-aspects-of-bd_mutex-nesting.patch
use-mutex_lock_nested-for-bd_mutex-to-avoid-lockdep-warning.patch
avoid-lockdep-warning-in-md.patch
bdev-fix-bd_part_count-leak.patch
lockdep-annotate-nfsd4-recover-code.patch
-
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