From e5bb62b63ae07e930719b02105103ff1dc3e12d0 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Wed, 17 Aug 2016 14:42:09 -0700 Subject: [PATCH] rculist: Consolidate DEBUG_LIST for list_add_rcu() This commit consolidates the debug checking for list_add_rcu() into the new single __list_add_valid() debug function. Notably, this commit fixes the sanity check that was added in commit 17a801f4bfeb ("list_debug: WARN for adding something already in the list"), which wasn't checking RCU-protected lists. Signed-off-by: Kees Cook Acked-by: Steven Rostedt Signed-off-by: Paul E. McKenney Acked-by: Rik van Riel --- include/linux/rculist.h | 8 +++----- lib/list_debug.c | 19 ------------------- 2 files changed, 3 insertions(+), 24 deletions(-) diff --git a/include/linux/rculist.h b/include/linux/rculist.h index 8beb98dcf14f..4f7a9561b8c4 100644 --- a/include/linux/rculist.h +++ b/include/linux/rculist.h @@ -45,19 +45,17 @@ static inline void INIT_LIST_HEAD_RCU(struct list_head *list) * 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) { + if (!__list_add_valid(new, prev, next)) + return; + new->next = next; new->prev = prev; rcu_assign_pointer(list_next_rcu(prev), new); next->prev = new; } -#else -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 diff --git a/lib/list_debug.c b/lib/list_debug.c index 149dd57b583b..d0b89b9d0736 100644 --- a/lib/list_debug.c +++ b/lib/list_debug.c @@ -77,22 +77,3 @@ 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); -- 2.34.1