[PATCH 2/2] list: DEBUG_LIST for hlist

Akinobu Mita
2009-03-15T15:26:37Z

Add sanity checks in hlist manipulation when CONFIG_DEBUG_LIST is enabled.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
---
include/linux/list.h | 18 ++++++++++++++++++
lib/list_debug.c | 38 ++++++++++++++++++++++++++++++++++++++
2 files changed, 56 insertions(+)

Index: 2.6/include/linux/list.h
===================================================================
--- 2.6.orig/include/linux/list.h
+++ 2.6/include/linux/list.h
@@ -564,6 +564,12 @@ static inline int hlist_empty(const stru
return !h->first;
}

+#ifdef CONFIG_DEBUG_LIST
+
+extern void __hlist_del(struct hlist_node *n);
+
+#else
+
static inline void __hlist_del(struct hlist_node *n)
{
struct hlist_node *next = n->next;
@@ -573,6 +579,8 @@ static inline void __hlist_del(struct hl
next->pprev = pprev;
}

+#endif
+
static inline void hlist_del(struct hlist_node *n)
{
__hlist_del(n);
@@ -592,6 +600,14 @@ static inline void hlist_del_init(struct
* This is only for internal hlist manipulation where we know
* the pprev/next entries already!
*/
+
+#ifdef CONFIG_DEBUG_LIST
+
+extern void __hlist_add(struct hlist_node *new,
+ struct hlist_node **pprev, struct hlist_node *next);
+
+#else
+
static inline void __hlist_add(struct hlist_node *new,
struct hlist_node **pprev, struct hlist_node *next)
{
@@ -602,6 +618,8 @@ static inline void __hlist_add(struct hl
new->pprev = pprev;
}

+#endif
+
static inline void hlist_add_head(struct hlist_node *n, struct hlist_head *h)
{
__hlist_add(n, &h->first, h->first);
Index: 2.6/lib/list_debug.c
===================================================================
--- 2.6.orig/lib/list_debug.c
+++ 2.6/lib/list_debug.c
@@ -54,3 +54,41 @@ void list_del(struct list_head *entry)
entry->prev = LIST_POISON2;
}
EXPORT_SYMBOL(list_del);
+
+void __hlist_del(struct hlist_node *n)
+{
+ struct hlist_node *next = n->next;
+ struct hlist_node **pprev = n->pprev;
+
+ WARN(next && next->pprev != &n->next,
+ "hlist_del corruption. next->pprev should be %p, but was %p\n",
+ &n->next, next->pprev);
+ WARN(*pprev != n,
+ "hlist_del corruption. *pprev should be %p, but was %p\n",
+ n, *pprev);
+
+ *pprev = next;
+ if (next)
+ next->pprev = pprev;
+}
+EXPORT_SYMBOL(__hlist_del);
+
+void __hlist_add(struct hlist_node *new,
+ struct hlist_node **pprev, struct hlist_node *next)
+{
+ WARN(next && next->pprev != pprev,
+ "hlist_add corruption. next->pprev should be pprev (%p), "
+ "but was %p. (next=%p).\n",
+ pprev, next->pprev, next);
+ WARN(*pprev != next,
+ "hlist_add corruption. *pprev should be next (%p), "
+ "but was %p. (pprev=%p).\n",
+ next, *pprev, pprev);
+
+ new->next = next;
+ if (next)
+ next->pprev = &new->next;
+ *pprev = new;
+ new->pprev = pprev;
+}
+EXPORT_SYMBOL(__hlist_add);