From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: Re: [PATCH] Reduce number of pointer dereferences in IPv6 netfilter LOG module function dump_packet() Date: Mon, 15 Nov 2010 01:50:15 +0100 Message-ID: <1289782215.2743.167.camel@edumazet-laptop> References: Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Netfilter Core Team , Jan Rekorajski , "David S. Miller" , netfilter-devel@vger.kernel.org, netfilter@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org To: Jesper Juhl Return-path: In-Reply-To: Sender: netfilter-devel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Le dimanche 14 novembre 2010 =C3=A0 22:47 +0100, Jesper Juhl a =C3=A9cr= it : > By adding two pointer variables to=20 > net/ipv6/netfilter/ip6t_LOG.c::dump_packet() we can save 19 bytes of = =2Etext=20 > and many pointer dereferences. >=20 > before: > text data bss dec hex filename > 6258 600 3088 9946 26da net/ipv6/netfilter/ip6t_LOG.o >=20 > after: > text data bss dec hex filename > 6239 600 3088 9927 26c7 net/ipv6/netfilter/ip6t_LOG.o >=20 >=20 > Please Cc me on replies. >=20 >=20 > Signed-off-by: Jesper Juhl > --- > ip6t_LOG.c | 16 ++++++++++------ > 1 file changed, 10 insertions(+), 6 deletions(-) >=20 > diff --git a/net/ipv6/netfilter/ip6t_LOG.c b/net/ipv6/netfilter/ip6t_= LOG.c > index 09c8889..51d10a5 100644 > --- a/net/ipv6/netfilter/ip6t_LOG.c > +++ b/net/ipv6/netfilter/ip6t_LOG.c > @@ -46,6 +46,8 @@ static void dump_packet(struct sbuff *m, > unsigned int ptr; > unsigned int hdrlen =3D 0; > unsigned int logflags; > + struct sock *sk; > + struct socket *sk_socket; > =20 > if (info->type =3D=3D NF_LOG_TYPE_LOG) > logflags =3D info->u.log.logflags; > @@ -358,13 +360,15 @@ static void dump_packet(struct sbuff *m, > } > =20 > /* Max length: 15 "UID=3D4294967295 " */ > - if ((logflags & IP6T_LOG_UID) && recurse && skb->sk) { > - read_lock_bh(&skb->sk->sk_callback_lock); > - if (skb->sk->sk_socket && skb->sk->sk_socket->file) > + sk =3D skb->sk; > + sk_socket =3D sk->sk_socket; > + if ((logflags & IP6T_LOG_UID) && recurse && sk) { > + read_lock_bh(&sk->sk_callback_lock); > + if (sk_socket && sk_socket->file) > sb_add(m, "UID=3D%u GID=3D%u ", > - skb->sk->sk_socket->file->f_cred->fsuid, > - skb->sk->sk_socket->file->f_cred->fsgid); > - read_unlock_bh(&skb->sk->sk_callback_lock); > + sk_socket->file->f_cred->fsuid, > + sk_socket->file->f_cred->fsgid); > + read_unlock_bh(&sk->sk_callback_lock); > } > =20 > /* Max length: 16 "MARK=3D0xFFFFFFFF " */ >=20 >=20 >=20 Same comment than previous patch, you add a NULL dereference. -- To unsubscribe from this list: send the line "unsubscribe netfilter-dev= el" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html