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| author | Marcin Slusarz <marcin.slusarz@gmail.com> | 2011-05-28 13:23:42 +0200 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2011-06-20 14:38:43 +0200 |
| commit | 161b6ae0e067e421b20bb35caf66bdb405c929ac (patch) | |
| tree | ef8d7eb7d8b9acdfb6c6df40df771c6978d03132 /lib | |
| parent | f8b7fc6b514f34a51875dd48dff70d4d17a54f38 (diff) | |
| download | lwn-161b6ae0e067e421b20bb35caf66bdb405c929ac.tar.gz lwn-161b6ae0e067e421b20bb35caf66bdb405c929ac.zip | |
debugobjects: Fix boot crash when kmemleak and debugobjects enabled
Order of initialization look like this:
...
debugobjects
kmemleak
...(lots of other subsystems)...
workqueues (through early initcall)
...
debugobjects use schedule_work for batch freeing of its data and kmemleak
heavily use debugobjects, so when it comes to freeing and workqueues were
not initialized yet, kernel crashes:
BUG: unable to handle kernel NULL pointer dereference at (null)
IP: [<ffffffff810854d1>] __queue_work+0x29/0x41a
[<ffffffff81085910>] queue_work_on+0x16/0x1d
[<ffffffff81085abc>] queue_work+0x29/0x55
[<ffffffff81085afb>] schedule_work+0x13/0x15
[<ffffffff81242de1>] free_object+0x90/0x95
[<ffffffff81242f6d>] debug_check_no_obj_freed+0x187/0x1d3
[<ffffffff814b6504>] ? _raw_spin_unlock_irqrestore+0x30/0x4d
[<ffffffff8110bd14>] ? free_object_rcu+0x68/0x6d
[<ffffffff8110890c>] kmem_cache_free+0x64/0x12c
[<ffffffff8110bd14>] free_object_rcu+0x68/0x6d
[<ffffffff810b58bc>] __rcu_process_callbacks+0x1b6/0x2d9
...
because system_wq is NULL.
Fix it by checking if workqueues susbystem was initialized before using.
Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Dipankar Sarma <dipankar@in.ibm.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: stable@kernel.org
Link: http://lkml.kernel.org/r/20110528112342.GA3068@joi.lan
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/debugobjects.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/lib/debugobjects.c b/lib/debugobjects.c index 9d86e45086f5..a78b7c6e042c 100644 --- a/lib/debugobjects.c +++ b/lib/debugobjects.c @@ -198,7 +198,7 @@ static void free_object(struct debug_obj *obj) * initialized: */ if (obj_pool_free > ODEBUG_POOL_SIZE && obj_cache) - sched = !work_pending(&debug_obj_work); + sched = keventd_up() && !work_pending(&debug_obj_work); hlist_add_head(&obj->node, &obj_pool); obj_pool_free++; obj_pool_used--; |