[Devel] [PATCH RHEL9 COMMIT] net: tcp: use kfree_skb_reason() for tcp_v{4, 6}_do_rcv()

[Konstantin Khorenko]

The commit is pushed to "branch-rh9-5.14.0-162.6.1.vz9.18.x-ovz" and will appear at https://src.openvz.org/scm/ovz/vzkernel.git
after rh9-5.14.0-162.6.1.vz9.18.2
------>
commit 398cf4f6dde643f59f80b21988982e3a4b058b32
Author: Menglong Dong <imagedong at tencent.com>
Date:   Tue Jan 3 17:39:10 2023 +0200

    net: tcp: use kfree_skb_reason() for tcp_v{4, 6}_do_rcv()
    
    Replace kfree_skb() used in tcp_v4_do_rcv() and tcp_v6_do_rcv() with
    kfree_skb_reason().
    
    Reviewed-by: Mengen Sun <mengensun at tencent.com>
    Reviewed-by: Hao Peng <flyingpeng at tencent.com>
    Signed-off-by: Menglong Dong <imagedong at tencent.com>
    Reviewed-by: Eric Dumazet <edumazet at google.com>
    Reviewed-by: David Ahern <dsahern at kernel.org>
    Signed-off-by: David S. Miller <davem at davemloft.net>
    Acked-by: Nikolay Borisov <nborisov at suse.com>
    Signed-off-by: Nikolay Borisov <nikolay.borisov at virtuozzo.com>
    
    ======
    Patchset description:
    ms/net: Annotate skb free sites with reason
    
    This series backports most of the patches that add a reason to skb free sites.
    
    https://jira.sw.ru/browse/PSBM-143302
    
    Feature: net: improve verbosity of dropped packets reporting
---
 net/ipv4/tcp_ipv4.c | 5 ++++-
 net/ipv6/tcp_ipv6.c | 5 ++++-
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index cdc51d377d49..b1c845cf441e 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1693,6 +1693,7 @@ INDIRECT_CALLABLE_DECLARE(struct dst_entry *ipv4_dst_check(struct dst_entry *,
  */
 int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb)
 {
+	enum skb_drop_reason reason;
 	struct sock *rsk;
 
 	if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
@@ -1715,6 +1716,7 @@ int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb)
 		return 0;
 	}
 
+	reason = SKB_DROP_REASON_NOT_SPECIFIED;
 	if (tcp_checksum_complete(skb))
 		goto csum_err;
 
@@ -1742,7 +1744,7 @@ int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb)
 reset:
 	tcp_v4_send_reset(rsk, skb);
 discard:
-	kfree_skb(skb);
+	kfree_skb_reason(skb, reason);
 	/* Be careful here. If this function gets more complicated and
 	 * gcc suffers from register pressure on the x86, sk (in %ebx)
 	 * might be destroyed here. This current version compiles correctly,
@@ -1751,6 +1753,7 @@ int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb)
 	return 0;
 
 csum_err:
+	reason = SKB_DROP_REASON_TCP_CSUM;
 	trace_tcp_bad_csum(skb);
 	TCP_INC_STATS(sock_net(sk), TCP_MIB_CSUMERRORS);
 	TCP_INC_STATS(sock_net(sk), TCP_MIB_INERRS);
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 42854bdb6e1f..1f0d2ea486c6 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -1470,6 +1470,7 @@ static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
 {
 	struct ipv6_pinfo *np = tcp_inet6_sk(sk);
 	struct sk_buff *opt_skb = NULL;
+	enum skb_drop_reason reason;
 	struct tcp_sock *tp;
 
 	/* Imagine: socket is IPv6. IPv4 packet arrives,
@@ -1504,6 +1505,7 @@ static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
 	if (np->rxopt.all)
 		opt_skb = skb_clone(skb, sk_gfp_mask(sk, GFP_ATOMIC));
 
+	reason = SKB_DROP_REASON_NOT_SPECIFIED;
 	if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
 		struct dst_entry *dst;
 
@@ -1557,9 +1559,10 @@ static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
 discard:
 	if (opt_skb)
 		__kfree_skb(opt_skb);
-	kfree_skb(skb);
+	kfree_skb_reason(skb, reason);
 	return 0;
 csum_err:
+	reason = SKB_DROP_REASON_TCP_CSUM;
 	trace_tcp_bad_csum(skb);
 	TCP_INC_STATS(sock_net(sk), TCP_MIB_CSUMERRORS);
 	TCP_INC_STATS(sock_net(sk), TCP_MIB_INERRS);