Re: list_head debugging patch
From: William Lee Irwin III (wli@holomorphy.com)
Date: Thu May 29 2003 - 19:04:28 EST
On Thursday 29 May 2003 22:13, William Lee Irwin III wrote:
>>> Same thing; nuke the __list_head_check() check in list_empty()
>>> please.
On Thu, May 29, 2003 at 11:03:19PM +0200, Morten Helgesen wrote:
>> Ok, after having nuked __list_head_check() in list_empty() I can`t
>> seem to trigger any more list corruption on this box.
On Thu, May 29, 2003 at 02:09:08PM -0700, William Lee Irwin III wrote:
> Well, that's a hopeful sign; at some point maybe IDE will stop oopsing
> on me with it.
This time fixed up for list_emptY() and list_for_each*_safe()
--- linux-2.5.70/include/linux/list.h 2003-05-26 18:00:41.000000000 -0700
+++ pgcl-2.5.70-2/include/linux/list.h 2003-05-29 14:26:39.000000000 -0700
@@ -30,6 +30,22 @@
(ptr)->next = (ptr); (ptr)->prev = (ptr); \
} while (0)
+static inline void __list_head_check(const struct list_head *elem)
+{
+ if (elem->prev->next != elem) {
+ printk(KERN_CRIT "elem = %p, elem->prev = %p, "
+ "elem->prev->next = %p\n",
+ elem, elem->prev, elem->prev->next);
+ BUG();
+ }
+ if (elem->next->prev != elem) {
+ printk(KERN_CRIT "elem = %p, elem->next = %p, "
+ "elem->next->prev = %p\n",
+ elem, elem->next, elem->next->prev);
+ BUG();
+ }
+}
+
/*
* Insert a new entry between two known consecutive entries.
*
@@ -56,6 +72,7 @@
*/
static inline void list_add(struct list_head *new, struct list_head *head)
{
+ __list_head_check(head);
__list_add(new, head, head->next);
}
@@ -69,6 +86,7 @@
*/
static inline void list_add_tail(struct list_head *new, struct list_head *head)
{
+ __list_head_check(head);
__list_add(new, head->prev, head);
}
@@ -136,7 +154,10 @@
*/
static inline void list_del(struct list_head *entry)
{
+ __list_head_check(entry);
__list_del(entry->prev, entry->next);
+ entry->prev = (void *)0x7c7c7c7c;
+ entry->next = (void *)0x8d8d8d8d;
}
/**
* list_del_rcu - deletes entry from list without re-initialization
@@ -156,6 +177,7 @@
*/
static inline void list_del_init(struct list_head *entry)
{
+ __list_head_check(entry);
__list_del(entry->prev, entry->next);
INIT_LIST_HEAD(entry);
}
@@ -167,6 +189,8 @@
*/
static inline void list_move(struct list_head *list, struct list_head *head)
{
+ __list_head_check(list);
+ __list_head_check(head);
__list_del(list->prev, list->next);
list_add(list, head);
}
@@ -179,6 +203,8 @@
static inline void list_move_tail(struct list_head *list,
struct list_head *head)
{
+ __list_head_check(list);
+ __list_head_check(head);
__list_del(list->prev, list->next);
list_add_tail(list, head);
}
@@ -199,6 +225,9 @@
struct list_head *last = list->prev;
struct list_head *at = head->next;
+ __list_head_check(head);
+ __list_head_check(list);
+
first->prev = head;
head->next = first;
@@ -213,6 +242,8 @@
*/
static inline void list_splice(struct list_head *list, struct list_head *head)
{
+ __list_head_check(list);
+ __list_head_check(head);
if (!list_empty(list))
__list_splice(list, head);
}
@@ -227,6 +258,8 @@
static inline void list_splice_init(struct list_head *list,
struct list_head *head)
{
+ __list_head_check(list);
+ __list_head_check(head);
if (!list_empty(list)) {
__list_splice(list, head);
INIT_LIST_HEAD(list);
@@ -248,8 +281,9 @@
* @head: the head for your list.
*/
#define list_for_each(pos, head) \
- for (pos = (head)->next, prefetch(pos->next); pos != (head); \
- pos = pos->next, prefetch(pos->next))
+ for (pos = (head)->next, prefetch((pos)->next); pos != (head); \
+ __list_head_check(pos), __list_head_check(head), \
+ pos = (pos)->next, prefetch((pos)->next))
/**
* __list_for_each - iterate over a list
@@ -262,7 +296,11 @@
* or 1 entry) most of the time.
*/
#define __list_for_each(pos, head) \
- for (pos = (head)->next; pos != (head); pos = pos->next)
+ for (pos = (head)->next; \
+ pos != (head); \
+ __list_head_check(pos), \
+ __list_head_check(head), \
+ pos = pos->next)
/**
* list_for_each_prev - iterate over a list backwards
@@ -270,8 +308,9 @@
* @head: the head for your list.
*/
#define list_for_each_prev(pos, head) \
- for (pos = (head)->prev, prefetch(pos->prev); pos != (head); \
- pos = pos->prev, prefetch(pos->prev))
+ for (pos = (head)->prev, prefetch((pos)->prev); pos != (head); \
+ __list_head_check(pos), __list_head_check(head), \
+ pos = (pos)->prev, prefetch((pos)->prev))
/**
* list_for_each_safe - iterate over a list safe against removal of list entry
@@ -280,8 +319,9 @@
* @head: the head for your list.
*/
#define list_for_each_safe(pos, n, head) \
- for (pos = (head)->next, n = pos->next; pos != (head); \
- pos = n, n = pos->next)
+ for (pos = (head)->next, n = (pos)->next; pos != (head); \
+ __list_head_check(n), __list_head_check(head), \
+ pos = n, n = (pos)->next)
/**
* list_for_each_entry - iterate over list of given type
@@ -290,11 +330,28 @@
* @member: the name of the list_struct within the struct.
*/
#define list_for_each_entry(pos, head, member) \
- for (pos = list_entry((head)->next, typeof(*pos), member), \
- prefetch(pos->member.next); \
- &pos->member != (head); \
- pos = list_entry(pos->member.next, typeof(*pos), member), \
- prefetch(pos->member.next))
+ for (pos = list_entry((head)->next, typeof(*(pos)), member), \
+ prefetch((pos)->member.next); \
+ &(pos)->member != (head); \
+ pos = list_entry((pos)->member.next, typeof(*(pos)), member),\
+ __list_head_check(head), \
+ __list_head_check(&(pos)->member), \
+ prefetch((pos)->member.next))
+
+/**
+ * list_for_each_entry_prev - iterate over a list backwards
+ * @pos: the type * to use as a loop counter.
+ * @head: the head for your list.
+ * @member: the name of the list_struct within the struct.
+ */
+#define list_for_each_entry_prev(pos, head, member) \
+ for (pos = list_entry((head)->prev, typeof(*(pos)), member), \
+ prefetch((pos)->member.prev); \
+ &(pos)->member != (head); \
+ pos = list_entry((pos)->member.prev, typeof(*(pos)), member),\
+ __list_head_check(head), \
+ __list_head_check(&(pos)->member), \
+ prefetch((pos)->member.prev))
/**
* list_for_each_entry_safe - iterate over list of given type safe against removal of list entry
@@ -304,10 +361,11 @@
* @member: the name of the list_struct within the struct.
*/
#define list_for_each_entry_safe(pos, n, head, member) \
- for (pos = list_entry((head)->next, typeof(*pos), member), \
- n = list_entry(pos->member.next, typeof(*pos), member); \
- &pos->member != (head); \
- pos = n, n = list_entry(n->member.next, typeof(*n), member))
+ for (pos = list_entry((head)->next, typeof(*(pos)), member), \
+ n = list_entry((pos)->member.next, typeof(*(pos)), member);\
+ &(pos)->member != (head); \
+ __list_head_check(head), __list_head_check(&(n)->member), \
+ pos = n, n = list_entry((n)->member.next, typeof(*(n)), member))
/**
* list_for_each_rcu - iterate over an rcu-protected list
@@ -401,9 +459,15 @@
{
if (n->pprev)
__hlist_del(n);
+ n->next = (void *)0x9e9e9e9e;
+ n->pprev = (void *)0xafafafaf;
}
-#define hlist_del_rcu hlist_del /* list_del_rcu is identical too? */
+static __inline__ void hlist_del_rcu(struct hlist_node *n)
+{
+ if (n->pprev)
+ __hlist_del(n);
+}
static __inline__ void hlist_del_init(struct hlist_node *n)
{
-
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