From patchwork Fri Feb 28 10:01:30 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Geliang Tang X-Patchwork-Id: 13996125 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 DDE5925D218; Fri, 28 Feb 2025 10:01:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740736907; cv=none; b=k2wtEWr8KMKq0eOl7uEU164E1FLTJuGog8L8bd0dsmZCKHX+/WKbdpyLbhUfzHTLFyaQY9mrLYVyLuTKAzTFZOZrwhdu/Uind7ybfFlerUUGIHBvNKck9bsIJ0WqgqoWWQlXF9sJDBU6MFdMSQfgZRGf349TwogoarrtTQWoc3g= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740736907; c=relaxed/simple; bh=WG2xZI0wmFn+Azmg6PmV3m8qa+1ewbLpbNmj4jiXmJY=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=MlcnmXUZMfzeOA7lna+Vk3UvIfHt3tNDqicKqX/kXPJoSELrpSDOW23iMpnySi8APm+/D/6jUAs7nL1+WSrlNe5WgPqCKm5P8WGzo88K1AsIqfw3xZfOYKBIOB+xWpQt9P2kXE3UfhfxtF20cM/KodXhrICQhQD1Tegms5HZ10g= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Kr3e59p4; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Kr3e59p4" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B5372C4CED6; Fri, 28 Feb 2025 10:01:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1740736906; bh=WG2xZI0wmFn+Azmg6PmV3m8qa+1ewbLpbNmj4jiXmJY=; h=From:To:Cc:Subject:Date:From; b=Kr3e59p4oI135FiQwVWVoxKHXIKSsF8DyqNcr0YKvSHIIjXUQ2SfNWvnfVjQNCchF 6Quo2kp8M+Ny868FIibt3EuhvF0ffx2ZOSZS9g7WKsWpB+oGkUu6ix2OldsMRTYboE 5sfAhuWkOdtS7btQS3uVbZme7l6NWHtLJZDDqZysczdO0Dv4Iw7yBBBn3zezhmjnJf vfRxnS9ZUUQlKqufE97DKS8bf1DgTG4VZYprMx3bWYm5nEYd9V0ibvWIKQspg/mf33 VEYrY9ySmKFi3LCiGeNVUEjBedgFCv3b3maArlIpqTxTWDxABUYL5WA+FqmTkJaUBA UMFbGIr8ydauw== From: Geliang Tang To: Eric Dumazet , Kuniyuki Iwashima , Paolo Abeni , Willem de Bruijn , "David S. Miller" , Jakub Kicinski , Simon Horman , Neal Cardwell , David Ahern , Matthieu Baerts , Mat Martineau , Marcelo Ricardo Leitner , Xin Long Cc: Geliang Tang , netdev@vger.kernel.org, mptcp@lists.linux.dev, linux-sctp@vger.kernel.org Subject: [PATCH net-next v2 0/3] add sock_kmemdup helper Date: Fri, 28 Feb 2025 18:01:30 +0800 Message-ID: X-Mailer: git-send-email 2.43.0 Precedence: bulk X-Mailing-List: mptcp@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Geliang Tang v2: - add "EXPORT_SYMBOL(sock_kmemdup)" as Matthieu suggested. - drop the patch "use sock_kmemdup for tcp_ao_key". While developing MPTCP BPF path manager [1], I found it's useful to add a new sock_kmemdup() helper. My use case is this: In mptcp_userspace_pm_append_new_local_addr() function (see patch 3 in this patchset), it uses sock_kmalloc() to allocate an address entry "e", then immediately duplicate the input "entry" to it: ''' e = sock_kmalloc(sk, sizeof(*e), GFP_ATOMIC); if (!e) { ret = -ENOMEM; goto append_err; } *e = *entry; ''' When I implemented MPTCP BPF path manager, I needed to implement a code similar to this in BPF. The kfunc sock_kmalloc() can be easily invoked in BPF to allocate an entry "e", but the code "*e = *entry;" that assigns "entry" to "e" is not easy to implemented. I had to implement such a "copy entry" helper in BPF: ''' static void mptcp_pm_copy_addr(struct mptcp_addr_info *dst, struct mptcp_addr_info *src) { dst->id = src->id; dst->family = src->family; dst->port = src->port; if (src->family == AF_INET) { dst->addr.s_addr = src->addr.s_addr; } else if (src->family == AF_INET6) { dst->addr6.s6_addr32[0] = src->addr6.s6_addr32[0]; dst->addr6.s6_addr32[1] = src->addr6.s6_addr32[1]; dst->addr6.s6_addr32[2] = src->addr6.s6_addr32[2]; dst->addr6.s6_addr32[3] = src->addr6.s6_addr32[3]; } } static void mptcp_pm_copy_entry(struct mptcp_pm_addr_entry *dst, struct mptcp_pm_addr_entry *src) { mptcp_pm_copy_addr(&dst->addr, &src->addr); dst->flags = src->flags; dst->ifindex = src->ifindex; } ''' And add "write permission" for BPF to each field of mptcp_pm_addr_entry: ''' @@ static int bpf_mptcp_pm_btf_struct_access(struct bpf_verifier_log *log, case offsetof(struct mptcp_pm_addr_entry, addr.port): end = offsetofend(struct mptcp_pm_addr_entry, addr.port); break; #if IS_ENABLED(CONFIG_MPTCP_IPV6) case offsetof(struct mptcp_pm_addr_entry, addr.addr6.s6_addr32[0]): end = offsetofend(struct mptcp_pm_addr_entry, addr.addr6.s6_addr32[0]); break; case offsetof(struct mptcp_pm_addr_entry, addr.addr6.s6_addr32[1]): end = offsetofend(struct mptcp_pm_addr_entry, addr.addr6.s6_addr32[1]); break; case offsetof(struct mptcp_pm_addr_entry, addr.addr6.s6_addr32[2]): end = offsetofend(struct mptcp_pm_addr_entry, addr.addr6.s6_addr32[2]); break; case offsetof(struct mptcp_pm_addr_entry, addr.addr6.s6_addr32[3]): end = offsetofend(struct mptcp_pm_addr_entry, addr.addr6.s6_addr32[3]); break; #else case offsetof(struct mptcp_pm_addr_entry, addr.addr.s_addr): end = offsetofend(struct mptcp_pm_addr_entry, addr.addr.s_addr); break; #endif ''' But if there's a sock_kmemdup() helper, it will become much simpler, only need to call kfunc sock_kmemdup() instead in BPF. So this patchset adds this new helper and uses it in several places. [1] https://lore.kernel.org/mptcp/cover.1738924875.git.tanggeliang@kylinos.cn/ Geliang Tang (3): sock: add sock_kmemdup helper net: use sock_kmemdup for ip_options mptcp: use sock_kmemdup for address entry include/net/sock.h | 2 ++ net/core/sock.c | 16 ++++++++++++++++ net/ipv6/exthdrs.c | 3 +-- net/mptcp/pm_userspace.c | 3 +-- net/mptcp/protocol.c | 7 ++----- net/sctp/protocol.c | 7 ++----- 6 files changed, 24 insertions(+), 14 deletions(-) Acked-by: Matthieu Baerts (NGI0)