From nobody Sat Jul 25 07:27:10 2026 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 CB844303C8A for ; Fri, 17 Jul 2026 04:50:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784263826; cv=none; b=iwBY1DdPiKuUnle78EXDkYJ4YY+6Oxc2dZWCMMtHRVoYkyNL1E4iRF7zoOeBeBZBQ0wCVF229jFE0MEeiujfsw1Wi2+lz3BUAQV+r3CKCovU60mPpADqehGrXai/4xe1r9Z4dX/jK311Qxco2YKn+b8v3vm83kvXW9Ryd58/B+Q= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784263826; c=relaxed/simple; bh=I9IMlFd2xOnZC5R6Qm/LVSZxj9cai7sE5sbfm3aViLw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=BWA1hHkxRQrc2e2M4av3H/rrHL5i7bEnb8UZu4c1Tb0XlXhkwb7GmVXweJoF/MFEzAUETxR0fxjpRQOkJBMPSq0WcH+8h0uQZmcdFMJC0JT20C3XKEAvEaWNXSqLr2eaGSYAbMXN8c9P6dlz2qrQt3rLl8jCBUI5orb5PyxBqmQ= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=euTl/G8Y; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="euTl/G8Y" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EB4671F00A3A; Fri, 17 Jul 2026 04:50:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1784263825; bh=YmUcugeGeXi+5MXDad3HeCWFENW1OK2xtCUPhv1gVq0=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=euTl/G8YERmlYB6o0ScMG0J5sCuHKltxAB4SqR2xykOR1A9LMrA4JHn888g5NPX6X 3zBeyMtEodLN4AtImdjSDnvfYnS2L5znsoqia9IrEGIno3DkP9HweEinurBW2kphs0 G6PvrOCCJyLxCqsBHRvoYQo+2bT9RCiSiIhZZHlt4EKN80jGbWAH1BGlfQ0aGtQCab Zy3SRQcPpMKtESrISasVrP0Z1NOtvi18I12EShASlCT/ulQLlxCs9wjNMqRnL/bPaN KYk/sxj4/k5w5kJ3+30d7ZEF60tA4gxEIrARZEm3bvMbPvoghQBKb4zNhcxwReifIy 02xGhVCZsLA1w== From: Geliang Tang To: mptcp@lists.linux.dev Cc: Geliang Tang Subject: [PATCH mptcp-next v7 1/9] ipv4: fix uninitialized memory in zerocopy cmsg Date: Fri, 17 Jul 2026 12:50:10 +0800 Message-ID: <32bac661bcae143f7e63905dfb781c98e95cdde5.1784260668.git.tanggeliang@kylinos.cn> X-Mailer: git-send-email 2.53.0 In-Reply-To: References: Precedence: bulk X-Mailing-List: mptcp@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Geliang Tang When SOF_TIMESTAMPING_OPT_CMSG is enabled and applications read MSG_ZEROCOPY completion notifications from the error queue, the ipv4_datagram_support_cmsg() function attempts to read ip_hdr(skb)->saddr to populate IP_PKTINFO cmsg data. However, zerocopy completion notification skbs don't have IP headers, causing this read to access uninitialized memory which is then leaked to userspace via put_cmsg(). This is because the function checks PKTINFO_SKB_CB(skb)->ipi_ifindex (which aliases the ops pointer in ubuf_info_msgzc stored in skb->cb), and if non-NULL, proceeds to read ip_hdr(skb)->saddr without verifying that the skb actually has an IP header. Fix this by adding an early check for SO_EE_ORIGIN_ZEROCOPY and returning false, since zerocopy completion notifications don't have IP headers and IP_PKTINFO cmsg is not applicable to them. Fixes: 829ae9d61165 ("net-timestamp: allow reading recv cmsg on errqueue wi= th origin tstamp") Signed-off-by: Geliang Tang --- net/ipv4/ip_sockglue.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c index a55ef327ec93..59513f15e522 100644 --- a/net/ipv4/ip_sockglue.c +++ b/net/ipv4/ip_sockglue.c @@ -504,6 +504,12 @@ static bool ipv4_datagram_support_cmsg(const struct so= ck *sk, if (ee_origin =3D=3D SO_EE_ORIGIN_LOCAL) return false; =20 + /* Zerocopy completion notifications don't have IP headers, + * so IP_PKTINFO cmsg is not applicable. + */ + if (ee_origin =3D=3D SO_EE_ORIGIN_ZEROCOPY) + return false; + /* Support IP_PKTINFO on tstamp packets if requested, to correlate * timestamp with egress dev. Not possible for packets without iif * or without payload (SOF_TIMESTAMPING_OPT_TSONLY). --=20 2.53.0 From nobody Sat Jul 25 07:27:10 2026 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 8EBA6303C8A for ; Fri, 17 Jul 2026 04:50:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784263828; cv=none; b=DF5jGbBN08rfwlItdDBIHP1dlk9aqhBdkskJ111b6JFMFm0OkA9zZ2ktSdYdmskCLLRiGi8SFjDb/x5VTYqwYqjT6D3JF4yW7CqffGSX+sDcVNS/xwMZRUtyqfRiXdziDtUqOoKDfELfVFgM3VJyTDUY/80tpnp+fw6V5kyIzYE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784263828; c=relaxed/simple; bh=jME7UwAhFGdpy0DC+LD1XLRwwMwYlVOX++7xseGcuGo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=hqVSgxAtOdZrdDHEog205ZT/0O4KcLBcHljNFaoLEXOpf5a+qkZcgPiXi3NRuXJ4qnJ7Jc64YC7r7fuwlLQrVwfAYB6qdvJZVLu0beZxzxNlUyNVUudxUUCpWY2EJSSQWs9CyXpzPcysnGNp/eX9BPcNXMjYMv4a46Lduae+QJ8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Wz9y2iSU; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Wz9y2iSU" Received: by smtp.kernel.org (Postfix) with ESMTPSA id ABD1B1F000E9; Fri, 17 Jul 2026 04:50:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1784263827; bh=EYeyAMGYwgrEvRqPliDbY8/sG7cAJUpla97WO7oBIDM=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=Wz9y2iSUwfE2WJsfAZgaFAQ5z818KtYpITXRp3AaTFNlet0TZnq5slj2dXY+pLbEl +4QS07VXR6Uoi/2DLKweJ+fdWu7iz4wxG0AnnF9Um5joS63Ulz/QWizUOKOmaFq4IV HfbzXzGk/P1sqeoJpe1RbsMHHv00ThdtTJbpLSdjF1AmaWola2VtcC2hgwZW8xXPwu qrM+SGhj5ElKl6CBQQFP/lmWfj79UeFgic+EYPuyBd4iZzoBTdRtruzBX4l27MS1Cp NF0QcgSIysFcUjvJvu7sLfNBb1eMxm+nhnf2FXkWluqJpJ9E/3zktLjY7D1g+om+jv CB+XEnwKCmh0A== From: Geliang Tang To: mptcp@lists.linux.dev Cc: Geliang Tang , Paolo Abeni Subject: [PATCH mptcp-next v7 2/9] mptcp: use local variable tp in sendmsg_frag Date: Fri, 17 Jul 2026 12:50:11 +0800 Message-ID: <1bb1bbdcfc774167d4054c91536c9946f1c7732f.1784260668.git.tanggeliang@kylinos.cn> X-Mailer: git-send-email 2.53.0 In-Reply-To: References: Precedence: bulk X-Mailing-List: mptcp@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Geliang Tang In mptcp_sendmsg_frag(), tcp_sk(ssk) is called multiple times. Introduce a local variable 'tp' to hold the tcp_sock pointer and use it throughout the function. This avoids repeated dereferencing and improves code readability, with no functional change. Suggested-by: Paolo Abeni Signed-off-by: Geliang Tang --- net/mptcp/protocol.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index ffcf5a1788f6..1cab07b1b9b1 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -1375,6 +1375,7 @@ static int mptcp_sendmsg_frag(struct sock *sk, struct= sock *ssk, u64 data_seq =3D dfrag->data_seq + info->sent; int offset =3D dfrag->offset + info->sent; struct mptcp_sock *msk =3D mptcp_sk(sk); + struct tcp_sock *tp =3D tcp_sk(ssk); bool zero_window_probe =3D false; struct mptcp_ext *mpext =3D NULL; bool can_coalesce =3D false; @@ -1410,14 +1411,14 @@ static int mptcp_sendmsg_frag(struct sock *sk, stru= ct sock *ssk, mpext =3D mptcp_get_ext(skb); if (!mptcp_skb_can_collapse_to(data_seq, skb, mpext)) { TCP_SKB_CB(skb)->eor =3D 1; - tcp_mark_push(tcp_sk(ssk), skb); + tcp_mark_push(tp, skb); goto alloc_skb; } =20 i =3D skb_shinfo(skb)->nr_frags; can_coalesce =3D skb_can_coalesce(skb, i, dfrag->page, offset); if (!can_coalesce && i >=3D READ_ONCE(net_hotdata.sysctl_max_skb_frags))= { - tcp_mark_push(tcp_sk(ssk), skb); + tcp_mark_push(tp, skb); goto alloc_skb; } =20 @@ -1471,7 +1472,7 @@ static int mptcp_sendmsg_frag(struct sock *sk, struct= sock *ssk, skb->truesize +=3D copy; sk_wmem_queued_add(ssk, copy); sk_mem_charge(ssk, copy); - WRITE_ONCE(tcp_sk(ssk)->write_seq, tcp_sk(ssk)->write_seq + copy); + WRITE_ONCE(tp->write_seq, tp->write_seq + copy); TCP_SKB_CB(skb)->end_seq +=3D copy; tcp_skb_pcount_set(skb, 0); =20 --=20 2.53.0 From nobody Sat Jul 25 07:27:10 2026 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 691DB303C8A for ; Fri, 17 Jul 2026 04:50:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784263830; cv=none; b=auc1nWv4ttWVlOGzVkcao9AzpVZvQqgvqqAMjUoBwagqFJ3rUFgo4dT/bpAiX1zJZqwKRa09DDWSJ6byOaTFE0XzJr4+6exqFR1BdxG/SXqT2Kqdz0i6ZQUEtTESKwkMoZZP0PK6e+TwVxmpxTW8KgPse57MnnLmHQyr1DiL5cQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784263830; c=relaxed/simple; bh=cs9ZDRNpHUGOZhVgZLHEw9C7VMUcJdt8rlQlk1KLNQw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=nBECkiQW/lD1zoz1UpkuTnxa5vXsO/lREk6Gb0iNOvjK6gfEqFakswtMNF1LMAzwzGTRA76PkpO76GRq/NHa6ik5DAxh80SQ7rSTlaor0qDSIz3Xzqvy5hobvEgWWF0TSnYM7fs60SPsEwOm/ZmlocFHD8LCvieJrDyvl/FQq48= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=NSomSi46; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="NSomSi46" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D04881F00A3A; Fri, 17 Jul 2026 04:50:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1784263829; bh=ElSZlA4Rb1X0Hy0iYkwooMfxGtyLfN6d3LNYXmaf+tE=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=NSomSi46hLD7+4OsOiPp/TJAVpLiAdbii6g5tCyQPsYLCerlmQxeS+9cp71xpdVaj +vw+XdBZV0K42DCaY9Fj1/55sqsn+eXD9pYppCTMgGcnqp/KRrL7vYLfeXS26cMur8 kevbcrPfA4JEVYlhYLPNw35ipYXeze0o3tl7DrUnLg4ZQYVK+3wtq8ASohW1dOTDh1 2ABv1M8u9bvfQKp9d6dH6j1s8aedm4eB6/Y6h+L/lzy70aTX++ppoEXVInspjs1vQL rC7iuZToohhpaTiGJU9YHVIglRXPF2i3o1XEuCTk9aOchRu1TotFYS34hNQUhOd+tP bLTHkL6Y6lBlw== From: Geliang Tang To: mptcp@lists.linux.dev Cc: Geliang Tang Subject: [PATCH mptcp-next v7 3/9] mptcp: align struct mptcp_data_frag to 8 bytes on 32-bit Date: Fri, 17 Jul 2026 12:50:12 +0800 Message-ID: <54e907886c661227cf62641ad46bc470344b3613.1784260668.git.tanggeliang@kylinos.cn> X-Mailer: git-send-email 2.53.0 In-Reply-To: References: Precedence: bulk X-Mailing-List: mptcp@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Geliang Tang mptcp_carve_data_frag() places a struct mptcp_data_frag inside a page-frag region, using ALIGN(orig_offset, sizeof(long)) to compute the offset where the struct lives. On 64-bit Linux sizeof(long) is 8 and this works as intended. On 32-bit Linux sizeof(long) is 4, which only guarantees 4-byte alignment for the struct. struct mptcp_data_frag contains a u64 data_seq member, which requires 8-byte alignment. 4-byte-aligned 64-bit loads fault on 32-bit architectures that do not handle unaligned 64-bit accesses in hardware (armv7, mips, sparc, ...). The in-source comment near BUILD_BUG_ON that states "ALIGN(1, sizeof(long)) - 1, so 8-1" is misleading because it implicitly assumes sizeof(long) is always 8. Switch both the ALIGN() and the matching BUILD_BUG_ON to sizeof(u64) so the 8-byte alignment is enforced on every architecture, and the overhead u8 budget still fits the worst-case 7-byte padding plus the struct size. This is a no-op on 64-bit and a correctness fix on 32-bit. Signed-off-by: Geliang Tang --- net/mptcp/protocol.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 1cab07b1b9b1..ca0c02f3bfd3 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -1237,7 +1237,7 @@ static struct mptcp_data_frag * mptcp_carve_data_frag(const struct mptcp_sock *msk, struct page_frag *pfra= g, int orig_offset) { - int offset =3D ALIGN(orig_offset, sizeof(long)); + int offset =3D ALIGN(orig_offset, sizeof(u64)); struct mptcp_data_frag *dfrag; =20 dfrag =3D (struct mptcp_data_frag *)(page_to_virt(pfrag->page) + offset); @@ -4789,9 +4789,9 @@ void __init mptcp_proto_init(void) BUILD_BUG_ON(sizeof(struct mptcp_skb_cb) > sizeof_field(struct sk_buff, c= b)); =20 /* struct mptcp_data_frag: 'overhead' corresponds to the alignment - * (ALIGN(1, sizeof(long)) - 1, so 8-1) + the struct's size + * (ALIGN(1, sizeof(u64)) - 1, so 8-1) + the struct's size */ - BUILD_BUG_ON(ALIGN(1, sizeof(long)) - 1 + sizeof(struct mptcp_data_frag) + BUILD_BUG_ON(ALIGN(1, sizeof(u64)) - 1 + sizeof(struct mptcp_data_frag) > U8_MAX); } =20 --=20 2.53.0 From nobody Sat Jul 25 07:27:10 2026 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 3B51E347BD4 for ; Fri, 17 Jul 2026 04:50:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784263832; cv=none; b=nUPnlN4kKb/f/TIGHN2PQAjLYSWB4I83EcBCofb9iBMopRC83d8Usb8d9etNx4wfpY210N47mAAVJLiLCRvRvGlrQeD7gptylDa3acuxM836ExnaMrJkMhPeJ+1RtkBZa7dH4CxRcnae2ca3T6WrRMoCkU084tu1tXHkNQjut5E= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784263832; c=relaxed/simple; bh=VO2lWM9yY6PIOaTJ4sd3MLKK0esuT4PcPjMrYkyKJfU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=tNd/V/WTMTNNmS135B4XkxaqXKJIKs/jMzko8d+WeV53J69igcejUxClfe9rcn+20t/1O1+Q9gQvPct8btQUSSW1v+NZt9SetcCe39Wbk0pe7tBUp6FgoFFVlIrJPuWBx+qmzcJMp1ZCChoLk/RdD9tNj5fmmLbpqbMhUp0cpC8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=T/YcbnwL; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="T/YcbnwL" Received: by smtp.kernel.org (Postfix) with ESMTPSA id AA2561F000E9; Fri, 17 Jul 2026 04:50:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1784263830; bh=hBTp4gJcdKx312WpXFgr4fskzyl+43n/D4lcsgFrgyg=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=T/YcbnwLLxfH5Snc3JOUxyxmPUul785vuo5up4LDK9j6N97s+/YLB+KHmu6SZpviR NhP74mZ3wiDqjHPJCw3GnFqw/q+qmB+RAjnBNghUT1/g9VoDmcYZacyR7ytJ02n/LD /U+aMeZqfLR88+5WMo0m9R3nDZL5ZiFH+J6cc8ZL0M7D7GUmQKMSw4nQlXi+Kf4XqW c9Ij1KN8QxomKM7PQ0qFUulQXM8QUdkZiigIz19u3D96BmEXWaCoT80nKb3qhcjGuF KoPl6FTXNjPjSQnyv69Mnx9X6x0Iu7x0ytn+FiQH3TJmnL+3Rqtu6uQaVlh4tcoxk3 6UdnwJ9IBVLQA== From: Geliang Tang To: mptcp@lists.linux.dev Cc: Geliang Tang Subject: [PATCH mptcp-next v7 4/9] mptcp: remove redundant orig_offset in carve_data_frag Date: Fri, 17 Jul 2026 12:50:13 +0800 Message-ID: X-Mailer: git-send-email 2.53.0 In-Reply-To: References: Precedence: bulk X-Mailing-List: mptcp@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Geliang Tang mptcp_carve_data_frag() already receives struct page_frag via its 'pfrag' parameter, making the separate 'orig_offset' parameter redundant since it merely duplicates pfrag->offset. Simplify the function signature by removing this unnecessary parameter and directly accessing the offset from struct pfrag internally. Signed-off-by: Geliang Tang --- net/mptcp/protocol.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index ca0c02f3bfd3..6a9daa187dad 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -1234,12 +1234,13 @@ static bool mptcp_page_frag_refill(struct sock *sk,= struct page_frag *pfrag) } =20 static struct mptcp_data_frag * -mptcp_carve_data_frag(const struct mptcp_sock *msk, struct page_frag *pfra= g, - int orig_offset) +mptcp_carve_data_frag(const struct mptcp_sock *msk, struct page_frag *pfra= g) { - int offset =3D ALIGN(orig_offset, sizeof(u64)); + int orig_offset =3D pfrag->offset; struct mptcp_data_frag *dfrag; + int offset; =20 + offset =3D ALIGN(orig_offset, sizeof(u64)); dfrag =3D (struct mptcp_data_frag *)(page_to_virt(pfrag->page) + offset); dfrag->data_len =3D 0; dfrag->data_seq =3D msk->write_seq; @@ -2031,7 +2032,7 @@ static int mptcp_sendmsg(struct sock *sk, struct msgh= dr *msg, size_t len) if (!mptcp_page_frag_refill(sk, pfrag)) goto wait_for_memory; =20 - dfrag =3D mptcp_carve_data_frag(msk, pfrag, pfrag->offset); + dfrag =3D mptcp_carve_data_frag(msk, pfrag); frag_truesize =3D dfrag->overhead; } =20 --=20 2.53.0 From nobody Sat Jul 25 07:27:10 2026 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 CBBB7347BD4 for ; Fri, 17 Jul 2026 04:50:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784263834; cv=none; b=V8icol9ZZSccvvbKTk/F4p6zMYfp/YYHVrTT6CSGSZoiE7nhTKgoKSf3Hsc1euNPM/K5LsG/EzHKjtjWhX21dCD0Y7f+Wvful4FcjCaZZQ4MZovaYWXai0w2e9w+F3VzqJszZKh6VjYNGaMGkCKOk1N6dy8e5Pn7s9dLL+dXBus= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784263834; c=relaxed/simple; bh=GOmNuNbm9K1iFPshyvOqSGan7qzBqcYux5IAtDKJFBg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=adn9ADEygz17BQg38NU4zZQj1djQFC03N1gGgBBo2JGjyzsLOHWxtMmJjyR8Mqg0SeTKVRBLotACy2GQaWRgkUtpnh9/A5vGZnHyCPtviZaDFUS/R/+yn8kC0TR+ZFg4dY2PQV49TCCUTuv3pvkqHMpwssjqWIDi4Y6HiL0EtOQ= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=gDNTG2/G; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="gDNTG2/G" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 83F391F00A3A; Fri, 17 Jul 2026 04:50:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1784263832; bh=dC4wnq62TLEzYS9XGKlPKRska9aL+BuKGqITsmdoXD8=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=gDNTG2/GQrSsNIAfOZ00NzE1JNGL1d3JUej7NRzNBj8/qvNVcHOO4G0c++7oHkg7V YIGkNVCw606RBIgmVPkar/Q2A1pm8DD8dsXl1oFBcupmHSUIjav1+xb+ta7a2uYiZC N2eOtST+2XGJCSy0lJ1bmJVQpZVInrCKXRi/HHOJ6BzmsM8s9me0Z37e7Me9xk2eMl Ro0ya8wxoul2CGdcl4fR2Wr3R8Mn4a9CgvGvBZYVPXfC2tjF1qFY2kXufUMCod/iDK bj4IWsKHmp0HkQGC3VG6fwykYNgtfUuziY9UZBKUU3/5JpopmGC/05XNzGAyDgLVdk TFdn//iCoSDtw== From: Geliang Tang To: mptcp@lists.linux.dev Cc: Geliang Tang Subject: [PATCH mptcp-next v7 5/9] mptcp: add MSG_ZEROCOPY support Date: Fri, 17 Jul 2026 12:50:14 +0800 Message-ID: <2a7c1b1838b75a83700c060da3068244681f1943.1784260668.git.tanggeliang@kylinos.cn> X-Mailer: git-send-email 2.53.0 In-Reply-To: References: Precedence: bulk X-Mailing-List: mptcp@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Geliang Tang This patch enables MSG_ZEROCOPY support for MPTCP sockets, allowing user-space to transmit data without intermediate kernel copies. The implementation follows the same lifecycle model as TCP: A single ubuf_info_msgzc is allocated per sendmsg via msg_zerocopy_realloc(). Its reference count consists of three parts: one 'caller' reference held until sendmsg returns, one reference per MPTCP dfrag in the retransmission queue (released when the dfrag is acked and cleared), and one reference per subflow skb that consumes dfrag bytes (released by TCP's skb_zcopy_clear() when the skb is acked). Completion is reported only after all bytes are acknowledged at both MPTCP and subflow levels. User pages are pinned via iov_iter_get_pages2() and stored directly in a newly allocated mptcp_data_frag. The dfrag takes one reference on the ubuf_info and one on the page. Subflow skbs take additional page references via get_page() and are marked with skb_zcopy_set() and SKBFL_PURE_ZEROCOPY, mirroring TCP's behavior and bypassing kernel memory accounting for those pages. The feature is silently downgraded to regular copy when MSG_FASTOPEN is set or the application has not opted in via setsockopt(SO_ZEROCOPY). If msg_zerocopy_realloc() fails (e.g. RLIMIT_MEMLOCK pressure), sendmsg(2) aborts with -ENOBUFS. The implementation prevents coalescing of dfrags with different ubuf instances into the same subflow skb to avoid premature completion notifications: a coalescing break is taken when the skb's pure-zerocopy state differs from the incoming dfrag, and another when both dfrags have ubuf instances but they differ. The new mptcp_sendmsg_zerocopy_iter() helper caps pg_len to U16_MAX (reverting the excess from the iov_iter when iov_iter_get_pages2() returns more than that) and returns -EFAULT when pg_off exceeds U16_MAX (which can happen on 256KB-page kernels like PowerPC and Hexagon), so the u16 dfrag->data_len and dfrag->offset fields cannot wrap. The caller accumulates the per-iteration byte count via the ssize_t return value. The non-zerocopy path is left untouched. When iov_iter_get_pages2() returns 0, the function returns -EFAULT to properly signal iterator exhaustion. Signed-off-by: Geliang Tang --- net/mptcp/protocol.c | 132 ++++++++++++++++++++++++++++++++++++++++--- net/mptcp/protocol.h | 1 + 2 files changed, 126 insertions(+), 7 deletions(-) diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 6a9daa187dad..8b58309566b8 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -1118,9 +1118,11 @@ static bool mptcp_frag_can_collapse_to(const struct = mptcp_sock *msk, df->data_seq + df->data_len =3D=3D msk->write_seq; } =20 -static void dfrag_uncharge(struct sock *sk, int len) +static void dfrag_uncharge(struct sock *sk, int len, + struct mptcp_data_frag *dfrag) { - sk_mem_uncharge(sk, len); + if (!dfrag->ubuf) + sk_mem_uncharge(sk, len); sk_wmem_queued_add(sk, -len); } =20 @@ -1129,7 +1131,13 @@ static void dfrag_clear(struct sock *sk, struct mptc= p_data_frag *dfrag) int len =3D dfrag->data_len + dfrag->overhead; =20 list_del(&dfrag->list); - dfrag_uncharge(sk, len); + dfrag_uncharge(sk, len, dfrag); + if (dfrag->ubuf) { + net_zcopy_put(dfrag->ubuf); + put_page(dfrag->page); + kfree(dfrag); + return; + } put_page(dfrag->page); } =20 @@ -1174,7 +1182,7 @@ static void __mptcp_clean_una(struct sock *sk) dfrag->data_len -=3D delta; dfrag->already_sent -=3D delta; =20 - dfrag_uncharge(sk, delta); + dfrag_uncharge(sk, delta, dfrag); } =20 /* all retransmitted data acked, recovery completed */ @@ -1249,6 +1257,7 @@ mptcp_carve_data_frag(const struct mptcp_sock *msk, s= truct page_frag *pfrag) dfrag->already_sent =3D 0; dfrag->page =3D pfrag->page; dfrag->eor =3D 0; + dfrag->ubuf =3D NULL; =20 return dfrag; } @@ -1416,6 +1425,16 @@ static int mptcp_sendmsg_frag(struct sock *sk, struc= t sock *ssk, goto alloc_skb; } =20 + if (skb_zcopy_pure(skb) !=3D !!dfrag->ubuf) { + tcp_mark_push(tp, skb); + goto alloc_skb; + } + if (dfrag->ubuf && skb_zcopy(skb) && + skb_zcopy(skb) !=3D dfrag->ubuf) { + tcp_mark_push(tp, skb); + goto alloc_skb; + } + i =3D skb_shinfo(skb)->nr_frags; can_coalesce =3D skb_can_coalesce(skb, i, dfrag->page, offset); if (!can_coalesce && i >=3D READ_ONCE(net_hotdata.sysctl_max_skb_frags))= { @@ -1456,7 +1475,7 @@ static int mptcp_sendmsg_frag(struct sock *sk, struct= sock *ssk, } =20 copy =3D min_t(size_t, copy, info->limit - info->sent); - if (!sk_wmem_schedule(ssk, copy)) { + if (!dfrag->ubuf && !sk_wmem_schedule(ssk, copy)) { tcp_remove_empty_skb(ssk); return -ENOMEM; } @@ -1466,13 +1485,19 @@ static int mptcp_sendmsg_frag(struct sock *sk, stru= ct sock *ssk, } else { get_page(dfrag->page); skb_fill_page_desc(skb, i, dfrag->page, offset, copy); + + if (dfrag->ubuf && !skb_zcopy(skb)) { + skb_zcopy_set(skb, dfrag->ubuf, NULL); + skb_shinfo(skb)->flags |=3D SKBFL_PURE_ZEROCOPY; + } } =20 skb->len +=3D copy; skb->data_len +=3D copy; skb->truesize +=3D copy; sk_wmem_queued_add(ssk, copy); - sk_mem_charge(ssk, copy); + if (!skb_zcopy_pure(skb)) + sk_mem_charge(ssk, copy); WRITE_ONCE(tp->write_seq, tp->write_seq + copy); TCP_SKB_CB(skb)->end_seq +=3D copy; tcp_skb_pcount_set(skb, 0); @@ -1969,22 +1994,99 @@ static void mptcp_rps_record_subflows(const struct = mptcp_sock *msk) } } =20 +static ssize_t mptcp_sendmsg_zerocopy_iter(struct sock *sk, struct msghdr = *msg, + struct ubuf_info *ubuf, + u32 copy_limit) +{ + struct mptcp_sock *msk =3D mptcp_sk(sk); + struct mptcp_data_frag *dfrag; + struct page *pages[1] =3D {}; + size_t pg_off =3D 0; + ssize_t pg_len; + + pg_len =3D iov_iter_get_pages2(&msg->msg_iter, pages, + copy_limit, 1, &pg_off); + if (pg_len < 0) + return pg_len; + /* pg_len =3D=3D 0 means the iterator is exhausted */ + if (pg_len =3D=3D 0) + return -EFAULT; + + if (pg_len > U16_MAX) { + iov_iter_revert(&msg->msg_iter, pg_len - U16_MAX); + pg_len =3D U16_MAX; + } + + if (pg_off > U16_MAX) { + iov_iter_revert(&msg->msg_iter, pg_len); + put_page(pages[0]); + return -EFAULT; + } + + if (!sk_wmem_schedule(sk, pg_len + sizeof(*dfrag))) { + iov_iter_revert(&msg->msg_iter, pg_len); + put_page(pages[0]); + return -EAGAIN; + } + + dfrag =3D kzalloc_obj(*dfrag, GFP_KERNEL_ACCOUNT); + if (!dfrag) { + iov_iter_revert(&msg->msg_iter, pg_len); + put_page(pages[0]); + sk_forward_alloc_add(sk, -(pg_len + sizeof(*dfrag))); + return -ENOMEM; + } + + dfrag->data_len =3D pg_len; + dfrag->data_seq =3D msk->write_seq; + dfrag->offset =3D pg_off; + dfrag->page =3D pages[0]; + dfrag->ubuf =3D ubuf; + dfrag->overhead =3D sizeof(struct mptcp_data_frag); + + /* one ref for the dfrag; released in dfrag_clear */ + net_zcopy_get(ubuf); + + WRITE_ONCE(msk->write_seq, msk->write_seq + pg_len); + sk_wmem_queued_add(sk, pg_len + dfrag->overhead); + + list_add_tail(&dfrag->list, &msk->rtx_queue); + if (!msk->first_pending) + msk->first_pending =3D dfrag; + + return pg_len; +} + static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) { struct mptcp_sock *msk =3D mptcp_sk(sk); + struct ubuf_info *ubuf =3D NULL; struct page_frag *pfrag; size_t copied =3D 0; + bool zc =3D false; int ret =3D 0; long timeo; =20 /* silently ignore everything else */ msg->msg_flags &=3D MSG_MORE | MSG_DONTWAIT | MSG_NOSIGNAL | - MSG_FASTOPEN | MSG_EOR; + MSG_FASTOPEN | MSG_EOR | MSG_ZEROCOPY; =20 lock_sock(sk); =20 mptcp_rps_record_subflows(msk); =20 + if (msg->msg_flags & MSG_FASTOPEN || !sock_flag(sk, SOCK_ZEROCOPY)) + msg->msg_flags &=3D ~MSG_ZEROCOPY; + + if ((msg->msg_flags & MSG_ZEROCOPY) && len) { + ubuf =3D msg_zerocopy_realloc(sk, len, NULL, false); + if (!ubuf) { + ret =3D -ENOBUFS; + goto do_error; + } + zc =3D true; + } + if (unlikely(inet_test_bit(DEFER_CONNECT, sk) || msg->msg_flags & MSG_FASTOPEN)) { int copied_syn =3D 0; @@ -2023,6 +2125,16 @@ static int mptcp_sendmsg(struct sock *sk, struct msg= hdr *msg, size_t len) if (!copy_limit) goto wait_for_memory; =20 + if (zc) { + ret =3D mptcp_sendmsg_zerocopy_iter(sk, msg, ubuf, + copy_limit); + if (ret < 0) + goto do_error; + + copied +=3D ret; + continue; + } + /* reuse tail pfrag, if possible, or carve a new one from the * page allocator */ @@ -2098,6 +2210,8 @@ static int mptcp_sendmsg(struct sock *sk, struct msgh= dr *msg, size_t len) } =20 out: + if (zc) + net_zcopy_put(ubuf); release_sock(sk); return copied; =20 @@ -2106,6 +2220,10 @@ static int mptcp_sendmsg(struct sock *sk, struct msg= hdr *msg, size_t len) goto out; =20 copied =3D sk_stream_error(sk, msg->msg_flags, ret); + if (zc) { + net_zcopy_put_abort(ubuf, true); + zc =3D false; + } goto out; } =20 diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h index da40c6f3705f..f4e69ea51a94 100644 --- a/net/mptcp/protocol.h +++ b/net/mptcp/protocol.h @@ -268,6 +268,7 @@ struct mptcp_data_frag { u8 eor; /* currently using 1 bit */ u16 already_sent; struct page *page; + struct ubuf_info *ubuf; }; =20 /* Arbitrary compromise between as low as possible to react timely to subf= low --=20 2.53.0 From nobody Sat Jul 25 07:27:10 2026 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 A35FC304BDF for ; Fri, 17 Jul 2026 04:50:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784263835; cv=none; 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charset="utf-8" From: Geliang Tang SO_ZEROCOPY is currently rejected by MPTCP setsockopt with -EOPNOTSUPP, even though the matching MSG_ZEROCOPY path in mptcp_sendmsg() is wired up. As a result MSG_ZEROCOPY silently falls back to a copy on MPTCP sockets because the opt-in flag is never set. Expose SO_ZEROCOPY through the SOL_SOCKET setsockopt dispatcher. The new mptcp_setsockopt_sol_socket_zerocopy() helper validates that val is 0 or 1 (matching standard TCP sk_setsockopt) and flips SOCK_ZEROCOPY on the msk only. mptcp_sendmsg() consults the same flag directly, so opt-in is honoured on every data path without any cross-socket propagation. Signed-off-by: Geliang Tang --- net/mptcp/sockopt.c | 17 ++++++++++++++++- 1 file changed, 16 insertions(+), 1 deletion(-) diff --git a/net/mptcp/sockopt.c b/net/mptcp/sockopt.c index fcf6feb2a9eb..abcc7d4452b4 100644 --- a/net/mptcp/sockopt.c +++ b/net/mptcp/sockopt.c @@ -175,6 +175,19 @@ static int mptcp_setsockopt_sol_socket_tstamp(struct m= ptcp_sock *msk, int optnam return 0; } =20 +static int mptcp_setsockopt_sol_socket_zerocopy(struct mptcp_sock *msk, in= t val) +{ + struct sock *sk =3D (struct sock *)msk; + + if (val !=3D 0 && val !=3D 1) + return -EINVAL; + + lock_sock(sk); + sock_valbool_flag(sk, SOCK_ZEROCOPY, val); + release_sock(sk); + return 0; +} + static int mptcp_setsockopt_sol_socket_int(struct mptcp_sock *msk, int opt= name, sockptr_t optval, unsigned int optlen) @@ -203,6 +216,8 @@ static int mptcp_setsockopt_sol_socket_int(struct mptcp= _sock *msk, int optname, case SO_TIMESTAMPNS_OLD: case SO_TIMESTAMPNS_NEW: return mptcp_setsockopt_sol_socket_tstamp(msk, optname, val); + case SO_ZEROCOPY: + return mptcp_setsockopt_sol_socket_zerocopy(msk, val); } =20 return -ENOPROTOOPT; @@ -342,6 +357,7 @@ static int mptcp_setsockopt_sol_socket(struct mptcp_soc= k *msk, int optname, case SO_TIMESTAMP_NEW: case SO_TIMESTAMPNS_OLD: case SO_TIMESTAMPNS_NEW: + case SO_ZEROCOPY: return mptcp_setsockopt_sol_socket_int(msk, optname, optval, optlen); case SO_TIMESTAMPING_OLD: @@ -387,7 +403,6 @@ static int mptcp_setsockopt_sol_socket(struct mptcp_soc= k *msk, int optname, * SO_CNX_ADVICE is currently unsupported, could possibly be relevant, * but likely needs careful design * - * SO_ZEROCOPY is currently unsupported, TODO in sndmsg * SO_TXTIME is currently unsupported */ =20 --=20 2.53.0 From nobody Sat Jul 25 07:27:10 2026 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 2832F304BDF for ; Fri, 17 Jul 2026 04:50:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784263837; cv=none; b=MeCIukyBLYLSTFmdKKElnVc14p/kTb+vRt8UGTJ1PUrEM6Sy+iwD+6aOwnEFEgDGbmN+GJ7OL9B6633P/Tp0CBOChzXYARdmwXA3ZCQ4wJkxU7jqia7ZHBGCCh7n5wiUv0O/SO7czTpCe1lyu3GJmCAdRc2NHuHMYUNWgD+Mujw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784263837; c=relaxed/simple; bh=mB4ElubyuYVkTuLy6Ay8PCPnsTSm04VFaKyuPOovojo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Ld8oCoK8rAq1zA4UOZS4zN0HY8Ux01erROGtCjttMDiaba10funBu4nIkNHa03bRqatVoNr0kLLgUdVJ7IGkLgvS5KYHDpNSp5kQrZ692i5Bk7lnwMo/zVgzjSesjrEYERciJiJrL0uFe3kICvd8fvN7YgHNXb6PJuOtAvWbK7g= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=na42CF7p; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="na42CF7p" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 376211F00A3A; Fri, 17 Jul 2026 04:50:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1784263836; bh=NoHE9yCFCmcosyIGNKg3hVbsyiSvt+JXJynBvANWavU=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=na42CF7pS98lQyH3H3OEbMct1VeAyiflA9vq2UNXp1AlwR/foxziGBLZtBIkQH6fi 7JcAtCuWJGmCpSek0Uwcci7Tr7+EQ2WsH4E6UJy0WR8T5mVp1CE1Tn578HQTH/RDBj 1wyGOZwMWsE3TVO1UDhxj1BvvjDwn5/bbMepAlzD+yP/CwHk0/wAYQUFpTgLCK+ySC jFQt4+v+9mlue3vdFyUxkXb/bmXlQawF/NOTUK8Ub+DhqiKi1Jc6k1eN1Ix7gJ11LH BPvYKQ3ESrC4Vw+eLBuw8ORkUERS2oi50XX0SCGN8ozwD92Ux10jrAa+vXtFAj4Yli AkMlz6nHMxtbw== From: Geliang Tang To: mptcp@lists.linux.dev Cc: Geliang Tang Subject: [PATCH mptcp-next v7 7/9] selftests: mptcp: connect: add zerocopy io mode Date: Fri, 17 Jul 2026 12:50:16 +0800 Message-ID: <2e6b8d84bf48a8d7a9a5b4897786d0dc181ebe3f.1784260668.git.tanggeliang@kylinos.cn> X-Mailer: git-send-email 2.53.0 In-Reply-To: References: Precedence: bulk X-Mailing-List: mptcp@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Geliang Tang Add a new I/O mode 'zerocopy' to the mptcp_connect selftest, which uses sendmsg() with the MSG_ZEROCOPY flag to transmit data. This enables testing and performance validation of the zero-copy send path for both TCP and MPTCP connections. This mode is useful for benchmarking and for verifying correctness of MSG_ZEROCOPY handling in the MPTCP stack. The completion notification draining uses batched polling to handle large transfers that may generate multiple completion events across different TCP segments. Signed-off-by: Geliang Tang --- .../selftests/net/mptcp/mptcp_connect.c | 162 +++++++++++++++++- 1 file changed, 161 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/net/mptcp/mptcp_connect.c b/tools/test= ing/selftests/net/mptcp/mptcp_connect.c index ea4cb6c1bd5e..f6ebdc5bf745 100644 --- a/tools/testing/selftests/net/mptcp/mptcp_connect.c +++ b/tools/testing/selftests/net/mptcp/mptcp_connect.c @@ -33,6 +33,7 @@ #include #include #include +#include #include =20 extern int optind; @@ -53,6 +54,7 @@ enum cfg_mode { CFG_MODE_MMAP, CFG_MODE_SENDFILE, CFG_MODE_SPLICE, + CFG_MODE_ZEROCOPY, }; =20 enum cfg_peek { @@ -125,7 +127,7 @@ static void die_usage(void) fprintf(stderr, "\t-j -- add additional sleep at connection start and= tear down " "-- for MPJ tests\n"); fprintf(stderr, "\t-l -- listens mode, accepts incoming connection\n"= ); - fprintf(stderr, "\t-m [poll|mmap|sendfile|splice] -- use poll(default)/mm= ap+write/sendfile/splice\n"); + fprintf(stderr, "\t-m [poll|mmap|sendfile|splice|zerocopy] -- use poll(de= fault)/mmap+write/sendfile/splice/zerocopy\n"); fprintf(stderr, "\t-M mark -- set socket packet mark\n"); fprintf(stderr, "\t-o option -- test sockopt