| Message ID | 20211229143205.410731-3-imagedong@tencent.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | net: skb: introduce kfree_skb_with_reason() | expand |
On 12/29/21 7:32 AM, menglong8.dong@gmail.com wrote: > From: Menglong Dong <imagedong@tencent.com> > > Replace kfree_skb() with kfree_skb_with_reason() in tcp_v4_rcv(). > Following drop reason are added: > > SKB_DROP_REASON_NO_SOCK > SKB_DROP_REASON_BAD_PACKET > SKB_DROP_REASON_TCP_CSUM > > After this patch, 'kfree_skb' event will print message like this: > > $ TASK-PID CPU# ||||| TIMESTAMP FUNCTION > $ | | | ||||| | | > <idle>-0 [000] ..s1. 36.113438: kfree_skb: skbaddr=(____ptrval____) protocol=2048 location=(____ptrval____) reason: NO_SOCK > > The reason of skb drop is printed too. > > Signed-off-by: Menglong Dong <imagedong@tencent.com> > --- > include/linux/skbuff.h | 3 +++ > include/trace/events/skb.h | 3 +++ > net/ipv4/tcp_ipv4.c | 10 ++++++++-- your first patch set was targeting UDP and now you are starting with tcp? > 3 files changed, 14 insertions(+), 2 deletions(-) > > diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h > index 3620b3ff2154..f85db6c035d1 100644 > --- a/include/linux/skbuff.h > +++ b/include/linux/skbuff.h > @@ -313,6 +313,9 @@ struct sk_buff; > */ > enum skb_drop_reason { > SKB_DROP_REASON_NOT_SPECIFIED, > + SKB_DROP_REASON_NO_SOCK, SKB_DROP_REASON_NO_SOCKET > + SKB_DROP_REASON_BAD_PACKET, SKB_DROP_REASON_PKT_TOO_SMALL User oriented messages, not code based. > + SKB_DROP_REASON_TCP_CSUM, > SKB_DROP_REASON_MAX, > }; > > diff --git a/include/trace/events/skb.h b/include/trace/events/skb.h > index cab1c08a30cd..b9ea6b4ed7ec 100644 > --- a/include/trace/events/skb.h > +++ b/include/trace/events/skb.h > @@ -11,6 +11,9 @@ > > #define TRACE_SKB_DROP_REASON \ > EM(SKB_DROP_REASON_NOT_SPECIFIED, NOT_SPECIFIED) \ > + EM(SKB_DROP_REASON_NO_SOCK, NO_SOCK) \ > + EM(SKB_DROP_REASON_BAD_PACKET, BAD_PACKET) \ > + EM(SKB_DROP_REASON_TCP_CSUM, TCP_CSUM) \ > EMe(SKB_DROP_REASON_MAX, HAHA_MAX) > > #undef EM > diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c > index ac10e4cdd8d0..03dc4c79b84b 100644 > --- a/net/ipv4/tcp_ipv4.c > +++ b/net/ipv4/tcp_ipv4.c > @@ -1971,8 +1971,10 @@ int tcp_v4_rcv(struct sk_buff *skb) > const struct tcphdr *th; > bool refcounted; > struct sock *sk; > + int drop_reason; > int ret; > > + drop_reason = 0; drop_reason = SKB_DROP_REASON_NOT_SPECIFIED;
On Thu, Dec 30, 2021 at 4:18 AM David Ahern <dsahern@gmail.com> wrote: > > On 12/29/21 7:32 AM, menglong8.dong@gmail.com wrote: > > From: Menglong Dong <imagedong@tencent.com> > > > > Replace kfree_skb() with kfree_skb_with_reason() in tcp_v4_rcv(). > > Following drop reason are added: > > > > SKB_DROP_REASON_NO_SOCK > > SKB_DROP_REASON_BAD_PACKET > > SKB_DROP_REASON_TCP_CSUM > > > > After this patch, 'kfree_skb' event will print message like this: > > > > $ TASK-PID CPU# ||||| TIMESTAMP FUNCTION > > $ | | | ||||| | | > > <idle>-0 [000] ..s1. 36.113438: kfree_skb: skbaddr=(____ptrval____) protocol=2048 location=(____ptrval____) reason: NO_SOCK > > > > The reason of skb drop is printed too. > > > > Signed-off-by: Menglong Dong <imagedong@tencent.com> > > --- > > include/linux/skbuff.h | 3 +++ > > include/trace/events/skb.h | 3 +++ > > net/ipv4/tcp_ipv4.c | 10 ++++++++-- > > your first patch set was targeting UDP and now you are starting with tcp? Yeah, I think TCP is used more, which can be a good starting point. After all, general protocols are all my target. > > > > 3 files changed, 14 insertions(+), 2 deletions(-) > > > > diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h > > index 3620b3ff2154..f85db6c035d1 100644 > > --- a/include/linux/skbuff.h > > +++ b/include/linux/skbuff.h > > @@ -313,6 +313,9 @@ struct sk_buff; > > */ > > enum skb_drop_reason { > > SKB_DROP_REASON_NOT_SPECIFIED, > > + SKB_DROP_REASON_NO_SOCK, > > SKB_DROP_REASON_NO_SOCKET > > > + SKB_DROP_REASON_BAD_PACKET, > > SKB_DROP_REASON_PKT_TOO_SMALL > > User oriented messages, not code based. > Ok, get it! Thanks! Menglong Dong > > > + SKB_DROP_REASON_TCP_CSUM, > > SKB_DROP_REASON_MAX, > > }; > > > > diff --git a/include/trace/events/skb.h b/include/trace/events/skb.h > > index cab1c08a30cd..b9ea6b4ed7ec 100644 > > --- a/include/trace/events/skb.h > > +++ b/include/trace/events/skb.h > > @@ -11,6 +11,9 @@ > > > > #define TRACE_SKB_DROP_REASON \ > > EM(SKB_DROP_REASON_NOT_SPECIFIED, NOT_SPECIFIED) \ > > + EM(SKB_DROP_REASON_NO_SOCK, NO_SOCK) \ > > + EM(SKB_DROP_REASON_BAD_PACKET, BAD_PACKET) \ > > + EM(SKB_DROP_REASON_TCP_CSUM, TCP_CSUM) \ > > EMe(SKB_DROP_REASON_MAX, HAHA_MAX) > > > > #undef EM > > diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c > > index ac10e4cdd8d0..03dc4c79b84b 100644 > > --- a/net/ipv4/tcp_ipv4.c > > +++ b/net/ipv4/tcp_ipv4.c > > @@ -1971,8 +1971,10 @@ int tcp_v4_rcv(struct sk_buff *skb) > > const struct tcphdr *th; > > bool refcounted; > > struct sock *sk; > > + int drop_reason; > > int ret; > > > > + drop_reason = 0; > > drop_reason = SKB_DROP_REASON_NOT_SPECIFIED; >
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 3620b3ff2154..f85db6c035d1 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -313,6 +313,9 @@ struct sk_buff; */ enum skb_drop_reason { SKB_DROP_REASON_NOT_SPECIFIED, + SKB_DROP_REASON_NO_SOCK, + SKB_DROP_REASON_BAD_PACKET, + SKB_DROP_REASON_TCP_CSUM, SKB_DROP_REASON_MAX, }; diff --git a/include/trace/events/skb.h b/include/trace/events/skb.h index cab1c08a30cd..b9ea6b4ed7ec 100644 --- a/include/trace/events/skb.h +++ b/include/trace/events/skb.h @@ -11,6 +11,9 @@ #define TRACE_SKB_DROP_REASON \ EM(SKB_DROP_REASON_NOT_SPECIFIED, NOT_SPECIFIED) \ + EM(SKB_DROP_REASON_NO_SOCK, NO_SOCK) \ + EM(SKB_DROP_REASON_BAD_PACKET, BAD_PACKET) \ + EM(SKB_DROP_REASON_TCP_CSUM, TCP_CSUM) \ EMe(SKB_DROP_REASON_MAX, HAHA_MAX) #undef EM diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index ac10e4cdd8d0..03dc4c79b84b 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -1971,8 +1971,10 @@ int tcp_v4_rcv(struct sk_buff *skb) const struct tcphdr *th; bool refcounted; struct sock *sk; + int drop_reason; int ret; + drop_reason = 0; if (skb->pkt_type != PACKET_HOST) goto discard_it; @@ -1984,8 +1986,10 @@ int tcp_v4_rcv(struct sk_buff *skb) th = (const struct tcphdr *)skb->data; - if (unlikely(th->doff < sizeof(struct tcphdr) / 4)) + if (unlikely(th->doff < sizeof(struct tcphdr) / 4)) { + drop_reason = SKB_DROP_REASON_BAD_PACKET; goto bad_packet; + } if (!pskb_may_pull(skb, th->doff * 4)) goto discard_it; @@ -2124,6 +2128,7 @@ int tcp_v4_rcv(struct sk_buff *skb) return ret; no_tcp_socket: + drop_reason = SKB_DROP_REASON_NO_SOCK; if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) goto discard_it; @@ -2131,6 +2136,7 @@ int tcp_v4_rcv(struct sk_buff *skb) if (tcp_checksum_complete(skb)) { csum_error: + drop_reason = SKB_DROP_REASON_TCP_CSUM; trace_tcp_bad_csum(skb); __TCP_INC_STATS(net, TCP_MIB_CSUMERRORS); bad_packet: @@ -2141,7 +2147,7 @@ int tcp_v4_rcv(struct sk_buff *skb) discard_it: /* Discard frame. */ - kfree_skb(skb); + kfree_skb_with_reason(skb, drop_reason); return 0; discard_and_relse: