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	When list debugging is enabled, we aim to readably show list corruption errors, and the basic list_add/list_del operations end up having extra debugging code in them to do some basic validation of the list entries. However, "list_del_init()" and "list_move[_tail]()" ended up avoiding the debug code due to how they were written. This fixes that. So the _next_ time we have list_move() problems with stale list entries, we'll hopefully have an easier time finding them.. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
		
			
				
	
	
		
			75 lines
		
	
	
	
		
			1.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			75 lines
		
	
	
	
		
			1.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 * Copyright 2006, Red Hat, Inc., Dave Jones
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 * Released under the General Public License (GPL).
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 *
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 * This file contains the linked list implementations for
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 * DEBUG_LIST.
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 */
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#include <linux/module.h>
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#include <linux/list.h>
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/*
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 * Insert a new entry between two known consecutive entries.
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 *
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 * This is only for internal list manipulation where we know
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 * the prev/next entries already!
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 */
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void __list_add(struct list_head *new,
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			      struct list_head *prev,
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			      struct list_head *next)
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{
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	WARN(next->prev != prev,
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		"list_add corruption. next->prev should be "
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		"prev (%p), but was %p. (next=%p).\n",
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		prev, next->prev, next);
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	WARN(prev->next != next,
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		"list_add corruption. prev->next should be "
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		"next (%p), but was %p. (prev=%p).\n",
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		next, prev->next, prev);
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	next->prev = new;
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	new->next = next;
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	new->prev = prev;
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	prev->next = new;
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}
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EXPORT_SYMBOL(__list_add);
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void __list_del_entry(struct list_head *entry)
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{
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	struct list_head *prev, *next;
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	prev = entry->prev;
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	next = entry->next;
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	if (WARN(next == LIST_POISON1,
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		"list_del corruption, %p->next is LIST_POISON1 (%p)\n",
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		entry, LIST_POISON1) ||
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	    WARN(prev == LIST_POISON2,
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		"list_del corruption, %p->prev is LIST_POISON2 (%p)\n",
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		entry, LIST_POISON2) ||
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	    WARN(prev->next != entry,
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		"list_del corruption. prev->next should be %p, "
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		"but was %p\n", entry, prev->next) ||
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	    WARN(next->prev != entry,
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		"list_del corruption. next->prev should be %p, "
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		"but was %p\n", entry, next->prev))
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		return;
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	__list_del(prev, next);
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}
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EXPORT_SYMBOL(__list_del_entry);
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/**
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 * list_del - deletes entry from list.
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 * @entry: the element to delete from the list.
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 * Note: list_empty on entry does not return true after this, the entry is
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 * in an undefined state.
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 */
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void list_del(struct list_head *entry)
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{
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	__list_del_entry(entry);
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	entry->next = LIST_POISON1;
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	entry->prev = LIST_POISON2;
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}
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EXPORT_SYMBOL(list_del);
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