[PATCH] list_del debug check

A list_del() debugging check.  Has been in -mm for years.  Dave moved
list_del() out-of-line in the debug case, so this is now suitable for
mainline.

Cc: Dave Jones <davej@codemonkey.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 7 insertions, 5 deletions

diff --git a/lib/list_debug.c b/lib/list_debug.c
index 1aae85cef92..e80d27c9789 100644
--- a/lib/list_debug.c
+++ b/lib/list_debug.c
@@ -59,14 +59,17 @@ EXPORT_SYMBOL(list_add);
  */
 void list_del(struct list_head *entry)
 {
+        BUG_ON(entry->prev->next != entry);
+        BUG_ON(entry->next->prev != entry);
+
         if (unlikely(entry->prev->next != entry)) {
-                printk(KERN_ERR "list_del corruption. prev->next should be %p, but was %p\n",
-                        entry, entry->prev->next);
+                printk(KERN_ERR "list_del corruption. prev->next should be %p, "
+                                "but was %p\n", entry, entry->prev->next);
                 BUG();
         }
         if (unlikely(entry->next->prev != entry)) {
-                printk(KERN_ERR "list_del corruption. next->prev should be %p, but was %p\n",
-                        entry, entry->next->prev);
+                printk(KERN_ERR "list_del corruption. next->prev should be %p, "
+                                "but was %p\n", entry, entry->next->prev);
                 BUG();
         }
         __list_del(entry->prev, entry->next);
@@ -74,4 +77,3 @@ void list_del(struct list_head *entry)
         entry->prev = LIST_POISON2;
 }
 EXPORT_SYMBOL(list_del);
-