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| author | Vegard Nossum <vegard.nossum@gmail.com> | 2008-09-01 01:39:21 +0400 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2008-09-01 11:47:16 +0400 |
| commit | 673d62cc5ea6fca046650f17f77985b112c62322 (patch) | |
| tree | 7cde0d756ffa71ad732cc079d28254b256c14e68 /include | |
| parent | bef69ea0dcce574a425feb0a5aa4c63dd108b9a6 (diff) | |
| download | linux-673d62cc5ea6fca046650f17f77985b112c62322.tar.xz | |
debugobjects: fix lockdep warning
Daniel J. Blueman reported:
> =======================================================
> [ INFO: possible circular locking dependency detected ]
> 2.6.27-rc4-224c #1
> -------------------------------------------------------
> hald/4680 is trying to acquire lock:
> (&n->list_lock){++..}, at: [<ffffffff802bfa26>] add_partial+0x26/0x80
>
> but task is already holding lock:
> (&obj_hash[i].lock){++..}, at: [<ffffffff8041cfdc>]
> debug_object_free+0x5c/0x120
We fix it by moving the actual freeing to outside the lock (the lock
now only protects the list).
The pool lock is also promoted to irq-safe (suggested by Dan). It's
necessary because free_pool is now called outside the irq disabled
region. So we need to protect against an interrupt handler which calls
debug_object_init().
[tglx@linutronix.de: added hlist_move_list helper to avoid looping
through the list twice]
Reported-by: Daniel J Blueman <daniel.blueman@gmail.com>
Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/list.h | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/include/linux/list.h b/include/linux/list.h index db35ef02e745..969f6e92d089 100644 --- a/include/linux/list.h +++ b/include/linux/list.h @@ -619,6 +619,19 @@ static inline void hlist_add_after(struct hlist_node *n, next->next->pprev = &next->next; } +/* + * Move a list from one list head to another. Fixup the pprev + * reference of the first entry if it exists. + */ +static inline void hlist_move_list(struct hlist_head *old, + struct hlist_head *new) +{ + new->first = old->first; + if (new->first) + new->first->pprev = &new->first; + old->first = NULL; +} + #define hlist_entry(ptr, type, member) container_of(ptr,type,member) #define hlist_for_each(pos, head) \ |