rhashtable: Use rcu_dereference_all and rcu_dereference_all_check

Add rcu_dereference_all and rcu_dereference_all_check so that
library code such as rhashtable can be used with any RCU variant.

As it stands rcu_dereference is used within rashtable, which
creates false-positive warnings if the user calls it from another
RCU context, such as preempt_disable().

Use the rcu_dereference_all and rcu_dereference_all_check calls
in rhashtable to suppress these warnings.

Also replace the rcu_dereference_raw calls in the list iterators
with rcu_dereference_all to uncover buggy calls.

Reported-by: Menglong Dong <dongml2@chinatelecom.cn>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Reviewed-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 7 insertions, 7 deletions

diff --git a/include/linux/rhashtable.h b/include/linux/rhashtable.h
index e740157f3cd7..05a221ce79a6 100644
--- a/include/linux/rhashtable.h
+++ b/include/linux/rhashtable.h
@@ -272,13 +272,13 @@ struct rhash_lock_head __rcu **rht_bucket_nested_insert(
 	rcu_dereference_protected(p, lockdep_rht_mutex_is_held(ht))
 
 #define rht_dereference_rcu(p, ht) \
-	rcu_dereference_check(p, lockdep_rht_mutex_is_held(ht))
+	rcu_dereference_all_check(p, lockdep_rht_mutex_is_held(ht))
 
 #define rht_dereference_bucket(p, tbl, hash) \
 	rcu_dereference_protected(p, lockdep_rht_bucket_is_held(tbl, hash))
 
 #define rht_dereference_bucket_rcu(p, tbl, hash) \
-	rcu_dereference_check(p, lockdep_rht_bucket_is_held(tbl, hash))
+	rcu_dereference_all_check(p, lockdep_rht_bucket_is_held(tbl, hash))
 
 #define rht_entry(tpos, pos, member) \
 	({ tpos = container_of(pos, typeof(*tpos), member); 1; })
@@ -373,7 +373,7 @@ static inline struct rhash_head *__rht_ptr(
 static inline struct rhash_head *rht_ptr_rcu(
 	struct rhash_lock_head __rcu *const *bkt)
 {
-	return __rht_ptr(rcu_dereference(*bkt), bkt);
+	return __rht_ptr(rcu_dereference_all(*bkt), bkt);
 }
 
 static inline struct rhash_head *rht_ptr(
@@ -497,7 +497,7 @@ static inline void rht_assign_unlock(struct bucket_table *tbl,
 	for (({barrier(); }),						\
 	     pos = head;						\
 	     !rht_is_a_nulls(pos);					\
-	     pos = rcu_dereference_raw(pos->next))
+	     pos = rcu_dereference_all(pos->next))
 
 /**
  * rht_for_each_rcu - iterate over rcu hash chain
@@ -513,7 +513,7 @@ static inline void rht_assign_unlock(struct bucket_table *tbl,
 	for (({barrier(); }),					\
 	     pos = rht_ptr_rcu(rht_bucket(tbl, hash));		\
 	     !rht_is_a_nulls(pos);				\
-	     pos = rcu_dereference_raw(pos->next))
+	     pos = rcu_dereference_all(pos->next))
 
 /**
  * rht_for_each_entry_rcu_from - iterated over rcu hash chain from given head
@@ -560,7 +560,7 @@ static inline void rht_assign_unlock(struct bucket_table *tbl,
  * list returned by rhltable_lookup.
  */
 #define rhl_for_each_rcu(pos, list)					\
-	for (pos = list; pos; pos = rcu_dereference_raw(pos->next))
+	for (pos = list; pos; pos = rcu_dereference_all(pos->next))
 
 /**
  * rhl_for_each_entry_rcu - iterate over rcu hash table list of given type
@@ -574,7 +574,7 @@ static inline void rht_assign_unlock(struct bucket_table *tbl,
  */
 #define rhl_for_each_entry_rcu(tpos, pos, list, member)			\
 	for (pos = list; pos && rht_entry(tpos, pos, member);		\
-	     pos = rcu_dereference_raw(pos->next))
+	     pos = rcu_dereference_all(pos->next))
 
 static inline int rhashtable_compare(struct rhashtable_compare_arg *arg,
 				     const void *obj)