rculist: Fix sparse warning
authorYing Xue <ying.xue@windriver.com>
Fri, 12 Dec 2014 01:36:14 +0000 (09:36 +0800)
committerPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Tue, 6 Jan 2015 19:01:13 +0000 (11:01 -0800)
This fixes the following sparse warnings:

make C=1 CF=-D__CHECK_ENDIAN__ net/ipv6/addrconf.o
net/ipv6/addrconf.c:3495:9: error: incompatible types in comparison expression (different address spaces)
net/ipv6/addrconf.c:3495:9: error: incompatible types in comparison expression (different address spaces)
net/ipv6/addrconf.c:3495:9: error: incompatible types in comparison expression (different address spaces)
net/ipv6/addrconf.c:3495:9: error: incompatible types in comparison expression (different address spaces)

To silence these spare complaints, an RCU annotation should be added to
"next" pointer of hlist_node structure through hlist_next_rcu() macro
when iterating over a hlist with hlist_for_each_entry_continue_rcu_bh().

By the way, this commit also resolves the same error appearing in
hlist_for_each_entry_continue_rcu().

Signed-off-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
include/linux/rculist.h

index 529bc94..a18b16f 100644 (file)
@@ -524,11 +524,11 @@ static inline void hlist_add_behind_rcu(struct hlist_node *n,
  * @member:    the name of the hlist_node within the struct.
  */
 #define hlist_for_each_entry_continue_rcu(pos, member)                 \
-       for (pos = hlist_entry_safe(rcu_dereference((pos)->member.next),\
-                       typeof(*(pos)), member);                        \
+       for (pos = hlist_entry_safe(rcu_dereference_raw(hlist_next_rcu( \
+                       &(pos)->member)), typeof(*(pos)), member);      \
             pos;                                                       \
-            pos = hlist_entry_safe(rcu_dereference((pos)->member.next),\
-                       typeof(*(pos)), member))
+            pos = hlist_entry_safe(rcu_dereference_raw(hlist_next_rcu( \
+                       &(pos)->member)), typeof(*(pos)), member))
 
 /**
  * hlist_for_each_entry_continue_rcu_bh - iterate over a hlist continuing after current point
@@ -536,11 +536,11 @@ static inline void hlist_add_behind_rcu(struct hlist_node *n,
  * @member:    the name of the hlist_node within the struct.
  */
 #define hlist_for_each_entry_continue_rcu_bh(pos, member)              \
-       for (pos = hlist_entry_safe(rcu_dereference_bh((pos)->member.next),\
-                       typeof(*(pos)), member);                        \
+       for (pos = hlist_entry_safe(rcu_dereference_bh(hlist_next_rcu(  \
+                       &(pos)->member)), typeof(*(pos)), member);      \
             pos;                                                       \
-            pos = hlist_entry_safe(rcu_dereference_bh((pos)->member.next),\
-                       typeof(*(pos)), member))
+            pos = hlist_entry_safe(rcu_dereference_bh(hlist_next_rcu(  \
+                       &(pos)->member)), typeof(*(pos)), member))
 
 /**
  * hlist_for_each_entry_from_rcu - iterate over a hlist continuing from current point