Commit 559f9bad authored by Dave Jones's avatar Dave Jones Committed by Paul E. McKenney

rcu: List-debug variants of rcu list routines.

* Make __list_add_rcu check the next->prev and prev->next pointers
  just like __list_add does.
* Make list_del_rcu use __list_del_entry, which does the same checking
  at deletion time.

Has been running for a week here without anything being tripped up,
but it seems worth adding for completeness just in case something
ever does corrupt those lists.
Signed-off-by: default avatarDave Jones <davej@redhat.com>
Signed-off-by: default avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
parent 66f75a5d
......@@ -30,6 +30,7 @@
* This is only for internal list manipulation where we know
* the prev/next entries already!
*/
#ifndef CONFIG_DEBUG_LIST
static inline void __list_add_rcu(struct list_head *new,
struct list_head *prev, struct list_head *next)
{
......@@ -38,6 +39,10 @@ static inline void __list_add_rcu(struct list_head *new,
rcu_assign_pointer(list_next_rcu(prev), new);
next->prev = new;
}
#else
extern void __list_add_rcu(struct list_head *new,
struct list_head *prev, struct list_head *next);
#endif
/**
* list_add_rcu - add a new entry to rcu-protected list
......@@ -108,7 +113,7 @@ static inline void list_add_tail_rcu(struct list_head *new,
*/
static inline void list_del_rcu(struct list_head *entry)
{
__list_del(entry->prev, entry->next);
__list_del_entry(entry);
entry->prev = LIST_POISON2;
}
......
......@@ -10,6 +10,7 @@
#include <linux/list.h>
#include <linux/bug.h>
#include <linux/kernel.h>
#include <linux/rculist.h>
/*
* Insert a new entry between two known consecutive entries.
......@@ -75,3 +76,24 @@ void list_del(struct list_head *entry)
entry->prev = LIST_POISON2;
}
EXPORT_SYMBOL(list_del);
/*
* RCU variants.
*/
void __list_add_rcu(struct list_head *new,
struct list_head *prev, struct list_head *next)
{
WARN(next->prev != prev,
"list_add_rcu corruption. next->prev should be "
"prev (%p), but was %p. (next=%p).\n",
prev, next->prev, next);
WARN(prev->next != next,
"list_add_rcu corruption. prev->next should be "
"next (%p), but was %p. (prev=%p).\n",
next, prev->next, prev);
new->next = next;
new->prev = prev;
rcu_assign_pointer(list_next_rcu(prev), new);
next->prev = new;
}
EXPORT_SYMBOL(__list_add_rcu);
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