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-rw-r--r--lib/list_debug.c75
1 files changed, 75 insertions, 0 deletions
diff --git a/lib/list_debug.c b/lib/list_debug.c
new file mode 100644
index 00000000..b8029a55
--- /dev/null
+++ b/lib/list_debug.c
@@ -0,0 +1,75 @@
+/*
+ * Copyright 2006, Red Hat, Inc., Dave Jones
+ * Released under the General Public License (GPL).
+ *
+ * This file contains the linked list implementations for
+ * DEBUG_LIST.
+ */
+
+#include <linux/module.h>
+#include <linux/list.h>
+
+/*
+ * Insert a new entry between two known consecutive entries.
+ *
+ * This is only for internal list manipulation where we know
+ * the prev/next entries already!
+ */
+
+void __list_add(struct list_head *new,
+ struct list_head *prev,
+ struct list_head *next)
+{
+ WARN(next->prev != prev,
+ "list_add corruption. next->prev should be "
+ "prev (%p), but was %p. (next=%p).\n",
+ prev, next->prev, next);
+ WARN(prev->next != next,
+ "list_add corruption. prev->next should be "
+ "next (%p), but was %p. (prev=%p).\n",
+ next, prev->next, prev);
+ next->prev = new;
+ new->next = next;
+ new->prev = prev;
+ prev->next = new;
+}
+EXPORT_SYMBOL(__list_add);
+
+void __list_del_entry(struct list_head *entry)
+{
+ struct list_head *prev, *next;
+
+ prev = entry->prev;
+ next = entry->next;
+
+ if (WARN(next == LIST_POISON1,
+ "list_del corruption, %p->next is LIST_POISON1 (%p)\n",
+ entry, LIST_POISON1) ||
+ WARN(prev == LIST_POISON2,
+ "list_del corruption, %p->prev is LIST_POISON2 (%p)\n",
+ entry, LIST_POISON2) ||
+ WARN(prev->next != entry,
+ "list_del corruption. prev->next should be %p, "
+ "but was %p\n", entry, prev->next) ||
+ WARN(next->prev != entry,
+ "list_del corruption. next->prev should be %p, "
+ "but was %p\n", entry, next->prev))
+ return;
+
+ __list_del(prev, next);
+}
+EXPORT_SYMBOL(__list_del_entry);
+
+/**
+ * list_del - deletes entry from list.
+ * @entry: the element to delete from the list.
+ * Note: list_empty on entry does not return true after this, the entry is
+ * in an undefined state.
+ */
+void list_del(struct list_head *entry)
+{
+ __list_del_entry(entry);
+ entry->next = LIST_POISON1;
+ entry->prev = LIST_POISON2;
+}
+EXPORT_SYMBOL(list_del);