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authorDave Jones <davej@redhat.com>2006-09-29 01:59:00 -0700
committerLinus Torvalds <torvalds@g5.osdl.org>2006-09-29 09:18:05 -0700
commit199a9afc3dbe98c35326f1d3907ab94dae953a6e (patch)
treef656df600bec86e8764af2e33bc4a0b98330e758 /lib/list_debug.c
parentdf67b3daea602728b51325a4debaeeb912ee51d1 (diff)
downloadlinux-199a9afc3dbe98c35326f1d3907ab94dae953a6e.tar.gz
[PATCH] Debug variants of linked list macros
Signed-off-by: Dave Jones <davej@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'lib/list_debug.c')
-rw-r--r--lib/list_debug.c77
1 files changed, 77 insertions, 0 deletions
diff --git a/lib/list_debug.c b/lib/list_debug.c
new file mode 100644
index 00000000000..1aae85cef92
--- /dev/null
+++ b/lib/list_debug.c
@@ -0,0 +1,77 @@
+/*
+ * 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)
+{
+ if (unlikely(next->prev != prev)) {
+ printk(KERN_ERR "list_add corruption. next->prev should be %p, but was %p\n",
+ prev, next->prev);
+ BUG();
+ }
+ if (unlikely(prev->next != next)) {
+ printk(KERN_ERR "list_add corruption. prev->next should be %p, but was %p\n",
+ next, prev->next);
+ BUG();
+ }
+ next->prev = new;
+ new->next = next;
+ new->prev = prev;
+ prev->next = new;
+}
+EXPORT_SYMBOL(__list_add);
+
+/**
+ * list_add - add a new entry
+ * @new: new entry to be added
+ * @head: list head to add it after
+ *
+ * Insert a new entry after the specified head.
+ * This is good for implementing stacks.
+ */
+void list_add(struct list_head *new, struct list_head *head)
+{
+ __list_add(new, head, head->next);
+}
+EXPORT_SYMBOL(list_add);
+
+/**
+ * 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)
+{
+ 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);
+ 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);
+ BUG();
+ }
+ __list_del(entry->prev, entry->next);
+ entry->next = LIST_POISON1;
+ entry->prev = LIST_POISON2;
+}
+EXPORT_SYMBOL(list_del);
+