This fixes the following sparse 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 <[email protected]>
---
The commit is based on next.2014.12.11a branch of linux-rcu tree
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 372ad5e..6f7aefb 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))
#endif /* __KERNEL__ */
--
1.7.9.5
On Fri, Dec 12, 2014 at 09:36:14AM +0800, Ying Xue wrote:
> This fixes the following sparse 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 <[email protected]>
Queued for 3.20, thank you!
Thanx, Paul
> ---
> The commit is based on next.2014.12.11a branch of linux-rcu tree
>
> 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 372ad5e..6f7aefb 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))
>
>
> #endif /* __KERNEL__ */
> --
> 1.7.9.5
>