diff mbox series

[bpf-next,v4,3/4] skmsg: get rid of skb_clone()

Message ID 20220615162014.89193-4-xiyou.wangcong@gmail.com (mailing list archive)
State Accepted
Commit 57452d767feaeab405de3bff0d240c3ac84bfe0d
Delegated to: BPF
Headers show
Series sockmap: some performance optimizations | expand

Checks

Context Check Description
netdev/tree_selection success Clearly marked for bpf-next, async
netdev/fixes_present success Fixes tag not required for -next series
netdev/subject_prefix success Link
netdev/cover_letter success Series has a cover letter
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 8 this patch: 8
netdev/cc_maintainers warning 11 maintainers not CCed: songliubraving@fb.com ast@kernel.org pabeni@redhat.com davem@davemloft.net kuba@kernel.org yoshfuji@linux-ipv6.org yhs@fb.com kafai@fb.com dsahern@kernel.org andrii@kernel.org kpsingh@kernel.org
netdev/build_clang success Errors and warnings before: 6 this patch: 6
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 8 this patch: 8
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 30 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
bpf/vmtest-bpf-next-PR success PR summary
bpf/vmtest-bpf-next-VM_Test-1 success Logs for Kernel LATEST on ubuntu-latest with gcc
bpf/vmtest-bpf-next-VM_Test-2 success Logs for Kernel LATEST on ubuntu-latest with llvm-15
bpf/vmtest-bpf-next-VM_Test-3 success Logs for Kernel LATEST on z15 with gcc

Commit Message

Cong Wang June 15, 2022, 4:20 p.m. UTC 
From: Cong Wang <cong.wang@bytedance.com>

With ->read_skb() now we have an entire skb dequeued from
receive queue, now we just need to grab an addtional refcnt
before passing its ownership to recv actors.

And we should not touch them any more, particularly for
skb->sk. Fortunately, skb->sk is already set for most of
the protocols except UDP where skb->sk has been stolen,
so we have to fix it up for UDP case.

Cc: Eric Dumazet <edumazet@google.com>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Cong Wang <cong.wang@bytedance.com>
---
 net/core/skmsg.c | 7 +------
 net/ipv4/udp.c   | 1 +
 2 files changed, 2 insertions(+), 6 deletions(-)
diff mbox series

Patch

diff --git a/net/core/skmsg.c b/net/core/skmsg.c
index f7f63b7d990c..8b248d289c11 100644
--- a/net/core/skmsg.c
+++ b/net/core/skmsg.c
@@ -1167,10 +1167,7 @@  static int sk_psock_verdict_recv(struct sock *sk, struct sk_buff *skb)
 	int ret = __SK_DROP;
 	int len = skb->len;
 
-	/* clone here so sk_eat_skb() in tcp_read_sock does not drop our data */
-	skb = skb_clone(skb, GFP_ATOMIC);
-	if (!skb)
-		return 0;
+	skb_get(skb);
 
 	rcu_read_lock();
 	psock = sk_psock(sk);
@@ -1183,12 +1180,10 @@  static int sk_psock_verdict_recv(struct sock *sk, struct sk_buff *skb)
 	if (!prog)
 		prog = READ_ONCE(psock->progs.skb_verdict);
 	if (likely(prog)) {
-		skb->sk = sk;
 		skb_dst_drop(skb);
 		skb_bpf_redirect_clear(skb);
 		ret = bpf_prog_run_pin_on_cpu(prog, skb);
 		ret = sk_psock_map_verd(ret, skb_bpf_redirect_fetch(skb));
-		skb->sk = NULL;
 	}
 	if (sk_psock_verdict_apply(psock, skb, ret) < 0)
 		len = 0;
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 0a1e90b80e36..b09936ccf709 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -1817,6 +1817,7 @@  int udp_read_skb(struct sock *sk, skb_read_actor_t recv_actor)
 			continue;
 		}
 
+		WARN_ON(!skb_set_owner_sk_safe(skb, sk));
 		used = recv_actor(sk, skb);
 		if (used <= 0) {
 			if (!copied)