On 03/25/2015 09:49 PM, Paul E. McKenney wrote: > On Wed, Mar 25, 2015 at 12:43:38PM +0800, Ying Xue wrote: >> This fixes the following sparse warnings: >> >> make C=1 CF=-D__CHECK_ENDIAN__ net/tipc/name_table.o >> net/tipc/name_table.c:977:17: error: incompatible types in comparison >> expression (different address spaces) >> net/tipc/name_table.c:977:17: 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_from_rcu(). >> >> Signed-off-by: Ying Xue <[email protected]> > > If hlist_for_each_entry_from_rcu() is to use rcu_dereference_bh(), then > it needs to be named hlist_for_each_entry_from_rcu_bh(). If we want > to retain the generic nature, rcu_dereference_raw() would work. > > (Otherwise, we would get splats if this was used under rcu_read_lock() > rather than rcu_read_lock_bh().) >
Yes, you are absolutely right. Thanks to point out my mistake. I will fix it in next version. Regards, Ying > Thanx, Paul > >> --- >> include/linux/rculist.h | 4 ++-- >> 1 file changed, 2 insertions(+), 2 deletions(-) >> >> diff --git a/include/linux/rculist.h b/include/linux/rculist.h >> index a18b16f..18a3f15 100644 >> --- a/include/linux/rculist.h >> +++ b/include/linux/rculist.h >> @@ -549,8 +549,8 @@ static inline void hlist_add_behind_rcu(struct >> hlist_node *n, >> */ >> #define hlist_for_each_entry_from_rcu(pos, member) \ >> for (; pos; \ >> - pos = hlist_entry_safe(rcu_dereference((pos)->member.next),\ >> - typeof(*(pos)), member)) >> + pos = hlist_entry_safe(rcu_dereference_bh(hlist_next_rcu( \ >> + &(pos)->member)), typeof(*(pos)), member)) >> >> #endif /* __KERNEL__ */ >> #endif >> -- >> 1.7.9.5 >> > > > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
