[PATCH net-next RESEND 2/2] ipv6: fix sparse warning

From: Ying Xue
Date: Wed Dec 10 2014 - 03:47:55 EST


This fixes the following spare warning when using

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 above spare complaint, 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@xxxxxxxxxxxxx>
---
include/linux/rculist.h | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/include/linux/rculist.h b/include/linux/rculist.h
index 866d9c9..32bd4ad 100644
--- a/include/linux/rculist.h
+++ b/include/linux/rculist.h
@@ -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
--
1.7.9.5

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