From e3f76e3386ee38e3654e81c2f3933ccca1f2d639 Mon Sep 17 00:00:00 2001 From: Baruch Siach Date: Mon, 9 Aug 2010 17:20:53 -0700 Subject: [PATCH] list debugging: warn when deleting a deleted entry Use the magic LIST_POISON* values to detect an incorrect use of list_del on a deleted entry. This DEBUG_LIST specific warning is easier to understand than the generic Oops message caused by LIST_POISON dereference. Signed-off-by: Baruch Siach Cc: Dave Jones Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- lib/list_debug.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/lib/list_debug.c b/lib/list_debug.c index 1a39f4e3ae1f..344c710d16ca 100644 --- a/lib/list_debug.c +++ b/lib/list_debug.c @@ -43,6 +43,12 @@ EXPORT_SYMBOL(__list_add); */ void list_del(struct list_head *entry) { + WARN(entry->next == LIST_POISON1, + "list_del corruption, next is LIST_POISON1 (%p)\n", + LIST_POISON1); + WARN(entry->next != LIST_POISON1 && entry->prev == LIST_POISON2, + "list_del corruption, prev is LIST_POISON2 (%p)\n", + LIST_POISON2); WARN(entry->prev->next != entry, "list_del corruption. prev->next should be %p, " "but was %p\n", entry, entry->prev->next);