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authorMarcin Slusarz <marcin.slusarz@gmail.com>2011-05-28 13:23:42 +0200
committerGreg Kroah-Hartman <gregkh@suse.de>2011-07-13 05:31:24 +0200
commitb115036a750c9bba4b9a598683eb5105744fe196 (patch)
tree35100058d08387fc28c64d9bc5d5ad665effd5b1
parent72b6e8a847914a76cce6f0741a894872a55ec5f3 (diff)
debugobjects: Fix boot crash when kmemleak and debugobjects enabled
commit 161b6ae0e067e421b20bb35caf66bdb405c929ac upstream. 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> Link: http://lkml.kernel.org/r/20110528112342.GA3068@joi.lan Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
-rw-r--r--lib/debugobjects.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/lib/debugobjects.c b/lib/debugobjects.c
index a9a8996d286a..e64b04c68746 100644
--- a/lib/debugobjects.c
+++ b/lib/debugobjects.c
@@ -196,7 +196,7 @@ 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--;