Messages in this thread Patch in this message | | | From | Paul Gortmaker <> | Subject | [34-longterm 087/179] debugobjects: Fix boot crash when kmemleak and debugobjects enabled | Date | Mon, 14 May 2012 22:13:03 -0400 |
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From: Marcin Slusarz <marcin.slusarz@gmail.com>
------------------- This is a commit scheduled for the next v2.6.34 longterm release. http://git.kernel.org/?p=linux/kernel/git/paulg/longterm-queue-2.6.34.git If you see a problem with using this for longterm, please comment. -------------------
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: Paul Gortmaker <paul.gortmaker@windriver.com> --- lib/debugobjects.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/lib/debugobjects.c b/lib/debugobjects.c index b862b30..e60bd59 100644 --- a/lib/debugobjects.c +++ b/lib/debugobjects.c @@ -197,7 +197,7 @@ 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--; -- 1.7.9.6
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