commit: 161b6ae0e067e421b20bb35caf66bdb405c929ac From: Marcin Slusarz <marcin.slus...@gmail.com> Date: Sat, 28 May 2011 13:23:42 +0200 Subject: [PATCH] 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.slus...@gmail.com> Cc: Catalin Marinas <catalin.mari...@arm.com> Cc: Tejun Heo <t...@kernel.org> Cc: Dipankar Sarma <dipan...@in.ibm.com> Cc: Paul E. McKenney <paul...@linux.vnet.ibm.com> Cc: sta...@kernel.org Link: http://lkml.kernel.org/r/20110528112342.ga3...@joi.lan Signed-off-by: Thomas Gleixner <t...@linutronix.de> --- lib/debugobjects.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/lib/debugobjects.c b/lib/debugobjects.c index 9d86e45..a78b7c6 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--; _______________________________________________ stable mailing list stable@linux.kernel.org http://linux.kernel.org/mailman/listinfo/stable
