| Message ID | 1310521339-1115-1-git-send-email-loke.chetan@gmail.com |
|---|---|
| State | Superseded, archived |
| Delegated to: | David Miller |
| Headers | show |
Le mardi 12 juillet 2011 à 21:42 -0400, Chetan Loke a écrit : > Currently we flush tp_status and then flush the remainder of the header+payload. > tp_status should be flushed in the end to avoid stale data being read by user-space. > > > Signed-off-by: Chetan Loke <loke.chetan@gmail.com> > --- > net/packet/af_packet.c | 4 ++-- > 1 files changed, 2 insertions(+), 2 deletions(-) > > diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c > index d2294ad..f7be71f 100644 > --- a/net/packet/af_packet.c > +++ b/net/packet/af_packet.c > @@ -1129,8 +1129,6 @@ static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, > else > sll->sll_ifindex = dev->ifindex; > > - __packet_set_status(po, h.raw, status); > - smp_mb(); > #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 > { > u8 *start, *end; > @@ -1140,6 +1138,8 @@ static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, > flush_dcache_page(pgv_to_page(start)); > } > #endif > + smp_mb(); > + __packet_set_status(po, h.raw, status); > > sk->sk_data_ready(sk, 0); > Are you sure we can perform the flush_dcache_page() before smp_mb() ? I believe we should do one smp_wmb() before __packet_set_status() as well. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Tue, Jul 12, 2011 at 9:56 PM, Eric Dumazet <eric.dumazet@gmail.com> wrote: > Le mardi 12 juillet 2011 à 21:42 -0400, Chetan Loke a écrit : >> Currently we flush tp_status and then flush the remainder of the header+payload. >> tp_status should be flushed in the end to avoid stale data being read by user-space. >> >> >> Signed-off-by: Chetan Loke <loke.chetan@gmail.com> >> --- >> net/packet/af_packet.c | 4 ++-- >> 1 files changed, 2 insertions(+), 2 deletions(-) >> >> diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c >> index d2294ad..f7be71f 100644 >> --- a/net/packet/af_packet.c >> +++ b/net/packet/af_packet.c >> @@ -1129,8 +1129,6 @@ static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, >> else >> sll->sll_ifindex = dev->ifindex; >> >> - __packet_set_status(po, h.raw, status); >> - smp_mb(); >> #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 >> { >> u8 *start, *end; >> @@ -1140,6 +1138,8 @@ static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, >> flush_dcache_page(pgv_to_page(start)); >> } >> #endif >> + smp_mb(); >> + __packet_set_status(po, h.raw, status); >> >> sk->sk_data_ready(sk, 0); >> > > Are you sure we can perform the flush_dcache_page() before smp_mb() ? > > I believe we should do one smp_wmb() before __packet_set_status() as > well. Eric - something like this? #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 smp_wmb(); #endif __packet_set_status(po, h.raw, status); Chetan Loke -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index d2294ad..f7be71f 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -1129,8 +1129,6 @@ static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, else sll->sll_ifindex = dev->ifindex; - __packet_set_status(po, h.raw, status); - smp_mb(); #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 { u8 *start, *end; @@ -1140,6 +1138,8 @@ static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, flush_dcache_page(pgv_to_page(start)); } #endif + smp_mb(); + __packet_set_status(po, h.raw, status); sk->sk_data_ready(sk, 0);
Currently we flush tp_status and then flush the remainder of the header+payload. tp_status should be flushed in the end to avoid stale data being read by user-space. Signed-off-by: Chetan Loke <loke.chetan@gmail.com> --- net/packet/af_packet.c | 4 ++-- 1 files changed, 2 insertions(+), 2 deletions(-)