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authorVegard Nossum <vegard.nossum@gmail.com>2008-08-31 23:39:21 +0200
committerThomas Gleixner <tglx@linutronix.de>2008-09-01 09:47:16 +0200
commit673d62cc5ea6fca046650f17f77985b112c62322 (patch)
tree7cde0d756ffa71ad732cc079d28254b256c14e68 /include/linux/list.h
parentbef69ea0dcce574a425feb0a5aa4c63dd108b9a6 (diff)
downloadop-kernel-dev-673d62cc5ea6fca046650f17f77985b112c62322.zip
op-kernel-dev-673d62cc5ea6fca046650f17f77985b112c62322.tar.gz
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/linux/list.h')
-rw-r--r--include/linux/list.h13
1 files changed, 13 insertions, 0 deletions
diff --git a/include/linux/list.h b/include/linux/list.h
index db35ef0..969f6e9 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) \
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