mirror of
https://github.com/torvalds/linux.git
synced 2024-11-14 08:02:07 +00:00
e3f76e3386
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 <baruch@tkos.co.il> Cc: Dave Jones <davej@codemonkey.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
63 lines
1.7 KiB
C
63 lines
1.7 KiB
C
/*
|
|
* 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);
|
|
|
|
/**
|
|
* 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)
|
|
{
|
|
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);
|
|
WARN(entry->next->prev != entry,
|
|
"list_del corruption. next->prev should be %p, "
|
|
"but was %p\n", entry, entry->next->prev);
|
|
__list_del(entry->prev, entry->next);
|
|
entry->next = LIST_POISON1;
|
|
entry->prev = LIST_POISON2;
|
|
}
|
|
EXPORT_SYMBOL(list_del);
|