| From baf705661782e05364c072910c7c41e41d020921 Mon Sep 17 00:00:00 2001 |
| From: Marcin Slusarz <marcin.slusarz@gmail.com> |
| Date: Sat, 28 May 2011 13:23:42 +0200 |
| Subject: [PATCH] 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: 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 |
| |
