Message ID | 1461142655-5067-2-git-send-email-nicolas.dichtel@6wind.com |
---|---|
State | Changes Requested, archived |
Delegated to: | David Miller |
Headers | show |
On Wed, 2016-04-20 at 10:57 +0200, Nicolas Dichtel wrote: > IS_ALIGN() returns true when the alignment is as expected. The pad > attribute should be added only when the alignment is not 8. > > Fixes: 35c5845957c7 ("net: Add helpers for 64-bit aligning netlink attributes.") > Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> > --- > include/net/netlink.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/include/net/netlink.h b/include/net/netlink.h > index e644b3489acf..694caac31d2c 100644 > --- a/include/net/netlink.h > +++ b/include/net/netlink.h > @@ -1245,7 +1245,7 @@ static inline int nla_validate_nested(const struct nlattr *start, int maxtype, > static inline int nla_align_64bit(struct sk_buff *skb, int padattr) > { > #ifndef HAVE_EFFICIENT_UNALIGNED_ACCESS > - if (IS_ALIGNED((unsigned long)skb->data, 8)) { > + if (!IS_ALIGNED((unsigned long)skb->data, 8)) { > struct nlattr *attr = nla_reserve(skb, padattr, 0); > if (!attr) > return -EMSGSIZE; This is silly. How have you tested your patch exactly ? I guess David should have copied his original comment here. - * The nlattr header is 4 bytes in size, that's why we test - * if the skb->data _is_ aligned. This NOP attribute, plus - * nlattr header for IFLA_STATS64, will make nla_data() 8-byte - * aligned.
Le 20/04/2016 11:33, Eric Dumazet a écrit : [snip] > How have you tested your patch exactly ? As stated in the cover letter, I didn't test it. > > I guess David should have copied his original comment here. > > - * The nlattr header is 4 bytes in size, that's why we test > - * if the skb->data _is_ aligned. This NOP attribute, plus > - * nlattr header for IFLA_STATS64, will make nla_data() 8-byte > - * aligned. > > I knew I was missing something, thanks for the explanation. All other patches of this series need to be updated, I will do it if there is no other comment.
diff --git a/include/net/netlink.h b/include/net/netlink.h index e644b3489acf..694caac31d2c 100644 --- a/include/net/netlink.h +++ b/include/net/netlink.h @@ -1245,7 +1245,7 @@ static inline int nla_validate_nested(const struct nlattr *start, int maxtype, static inline int nla_align_64bit(struct sk_buff *skb, int padattr) { #ifndef HAVE_EFFICIENT_UNALIGNED_ACCESS - if (IS_ALIGNED((unsigned long)skb->data, 8)) { + if (!IS_ALIGNED((unsigned long)skb->data, 8)) { struct nlattr *attr = nla_reserve(skb, padattr, 0); if (!attr) return -EMSGSIZE;
IS_ALIGN() returns true when the alignment is as expected. The pad attribute should be added only when the alignment is not 8. Fixes: 35c5845957c7 ("net: Add helpers for 64-bit aligning netlink attributes.") Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> --- include/net/netlink.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)