From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-173.mta1.migadu.com (out-173.mta1.migadu.com [95.215.58.173]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4A8131991B6 for ; Sat, 25 Jan 2025 01:09:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.173 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737767393; cv=none; b=Hc3O9O6qKhf/VCiY31v3N8gdMOlmKoLmdJ53Y9s8VoWfIV3YIUuaFMfiMV4DX6F+mO6mC5oluIMI62meJdk9Ab9hUkPtevKX8VMKluy9gxvq+hA1Y0CdBsFaT+WPvzEbxMAuTLIXcut/8NePTifT8sOPRLjGwmx6eFbmOEMiK78= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737767393; c=relaxed/simple; bh=UmSAfM9RV8whxp65NUZ6e1UKVCRS0brhWpbzK1gCSYo=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=ICC++NJcRqLljmdU+LrXcOd1oZwIyGq6Vl6asZZG6DKYnTGJ5r0JsFYwf2GwFM/1U2Jzb4Q4IpBJ3/4Z+2oLzzeymje5HrQrq8D8iPRSlja/HRSYZBNvW6R7jRGQhEbGj9owt2FkjhtdS+4E0Gmzo5cjU9EakaTFE0hV96lte/4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=WHbDFiSv; arc=none smtp.client-ip=95.215.58.173 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="WHbDFiSv" Message-ID: <0697db8c-9909-4abb-932d-51413850cdd4@linux.dev> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1737767389; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=VlmsTZhWis28WVHX+6DJKvsE9ZhzkonmhfKddu+5WeY=; b=WHbDFiSv4NSBC1KDzq5VjRA082nhqvIOjzKAyS5jtRishgn2pSCT+lYIQv7xxrzr6SaOvh eLkCLV02VHjVNXLdGHvwJInFgJwKIYzUUsnZrnr5osUhgi1GbvZZr+EFBZRPCMHfi1nY9X dOBePuCxIxzIfhllwWKf3tE8LWg1TcY= Date: Fri, 24 Jan 2025 17:09:41 -0800 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: Re: [RFC PATCH net-next v6 12/13] net-timestamp: introduce cgroup lock to avoid affecting non-bpf cases To: Jason Xing Cc: davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, dsahern@kernel.org, willemdebruijn.kernel@gmail.com, willemb@google.com, ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, eddyz87@gmail.com, song@kernel.org, yonghong.song@linux.dev, john.fastabend@gmail.com, kpsingh@kernel.org, sdf@fomichev.me, haoluo@google.com, jolsa@kernel.org, horms@kernel.org, bpf@vger.kernel.org, netdev@vger.kernel.org References: <20250121012901.87763-1-kerneljasonxing@gmail.com> <20250121012901.87763-13-kerneljasonxing@gmail.com> X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Martin KaFai Lau Content-Language: en-US In-Reply-To: <20250121012901.87763-13-kerneljasonxing@gmail.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Migadu-Flow: FLOW_OUT On 1/20/25 5:29 PM, Jason Xing wrote: > Introducing the lock to avoid affecting the applications which > are not using timestamping bpf feature. > > Signed-off-by: Jason Xing > --- > net/core/skbuff.c | 6 ++++-- > net/ipv4/tcp.c | 3 ++- > net/ipv4/tcp_input.c | 3 ++- > net/ipv4/tcp_output.c | 3 ++- > 4 files changed, 10 insertions(+), 5 deletions(-) > > diff --git a/net/core/skbuff.c b/net/core/skbuff.c > index 33340e0b094f..db5b4b653351 100644 > --- a/net/core/skbuff.c > +++ b/net/core/skbuff.c > @@ -5605,11 +5605,13 @@ void __skb_tstamp_tx(struct sk_buff *orig_skb, > return; > > /* bpf extension feature entry */ > - if (skb_shinfo(orig_skb)->tx_flags & SKBTX_BPF) > + if (cgroup_bpf_enabled(CGROUP_SOCK_OPS) && I wonder if it is really needed. The caller has just tested the tx_flags. > + skb_shinfo(orig_skb)->tx_flags & SKBTX_BPF) > skb_tstamp_tx_bpf(orig_skb, sk, tstype, sw, hwtstamps); > > /* application feature entry */ > - if (!skb_enable_app_tstamp(orig_skb, tstype, sw)) > + if (cgroup_bpf_enabled(CGROUP_SOCK_OPS) && Same here and this one looks wrong also. The userspace may get something unexpected in the err queue. The bpf prog may have already detached here after setting the SKBTX_BPF earlier. > + !skb_enable_app_tstamp(orig_skb, tstype, sw)) > return; > > tsflags = READ_ONCE(sk->sk_tsflags); > diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c > index 49e489c346ea..d88160af00c4 100644 > --- a/net/ipv4/tcp.c > +++ b/net/ipv4/tcp.c > @@ -493,7 +493,8 @@ static void tcp_tx_timestamp(struct sock *sk, struct sockcm_cookie *sockc) > shinfo->tskey = TCP_SKB_CB(skb)->seq + skb->len - 1; > } > > - if (SK_BPF_CB_FLAG_TEST(sk, SK_BPF_CB_TX_TIMESTAMPING) && skb) { > + if (cgroup_bpf_enabled(CGROUP_SOCK_OPS) && This looks ok considering SK_BPF_CB_FLAG_TEST may get to another cacheline. > + SK_BPF_CB_FLAG_TEST(sk, SK_BPF_CB_TX_TIMESTAMPING) && skb) { > struct skb_shared_info *shinfo = skb_shinfo(skb); > struct tcp_skb_cb *tcb = TCP_SKB_CB(skb); > > diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c > index c8945f5be31b..e30607ba41e5 100644 > --- a/net/ipv4/tcp_input.c > +++ b/net/ipv4/tcp_input.c > @@ -3324,7 +3324,8 @@ static void tcp_ack_tstamp(struct sock *sk, struct sk_buff *skb, > > /* Avoid cache line misses to get skb_shinfo() and shinfo->tx_flags */ > if (likely(!TCP_SKB_CB(skb)->txstamp_ack && > - !TCP_SKB_CB(skb)->txstamp_ack_bpf)) > + !(cgroup_bpf_enabled(CGROUP_SOCK_OPS) && Same here. txtstamp_ack has just been tested.... txstamp_ack_bpf is the next bit. > + TCP_SKB_CB(skb)->txstamp_ack_bpf))) > return; > > shinfo = skb_shinfo(skb); > diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c > index fc84ca669b76..483f19c2083e 100644 > --- a/net/ipv4/tcp_output.c > +++ b/net/ipv4/tcp_output.c > @@ -1556,7 +1556,8 @@ static void tcp_adjust_pcount(struct sock *sk, const struct sk_buff *skb, int de > static bool tcp_has_tx_tstamp(const struct sk_buff *skb) > { > return TCP_SKB_CB(skb)->txstamp_ack || > - TCP_SKB_CB(skb)->txstamp_ack_bpf || > + (cgroup_bpf_enabled(CGROUP_SOCK_OPS) && Same here. > + TCP_SKB_CB(skb)->txstamp_ack_bpf) || > (skb_shinfo(skb)->tx_flags & SKBTX_ANY_TSTAMP); > } >