From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from stravinsky.debian.org (stravinsky.debian.org [82.195.75.108]) (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 C4CCB387378; Fri, 30 Jan 2026 18:47:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=82.195.75.108 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769798830; cv=none; b=FQliOOZo1GmR5g0zPYCpgLGl7G5GYOVf+snCCiVPPtmQB8NOTq8QVCwsJSuP1B+Lvja6tyrL8f5hD056Xuv/n4Y6xLnErlG372fucQobpOQkv6naNoCpSvwOLct1dXwZNX3379xZ/VNgWzEaE3ZzBGzgxmIJrq32AsSLVZpPAcU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769798830; c=relaxed/simple; bh=IVnLhnrcy/3xPEQctLWhlsnsImXX6rsH2GP1mnkmDNQ=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=ninl4gqEi+mhuXkI2SVPYjQm8YdlvBaPxO6fTdO2uCl59RQcc5oI8X0S6jLwwtFuYeJNSPC0lPtPsag3YeAH9MudQZQrZuwZH4LkKvlNQR8oqeOoNqkkCdL19pbQxiEmIhH566jsoUh8ktkqtv5yKb8zW7Zb4XrHcWfgb0owjUY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=debian.org; spf=none smtp.mailfrom=debian.org; dkim=pass (2048-bit key) header.d=debian.org header.i=@debian.org header.b=aRHmPsMW; arc=none smtp.client-ip=82.195.75.108 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=debian.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=debian.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=debian.org header.i=@debian.org header.b="aRHmPsMW" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=debian.org; s=smtpauto.stravinsky; h=X-Debian-User:Cc:To:In-Reply-To:References: Message-Id:Content-Transfer-Encoding:Content-Type:MIME-Version:Subject:Date: From:Reply-To:Content-ID:Content-Description; bh=gW70Iuxcr93CtMyUc93o0K6n2EmDcL/0tFhB6bt/uXk=; b=aRHmPsMWedGIXc2X0YSNAMvFAT gpBxbCe23doJ2GkVOjXk5qAtYdxfG7QHsv/GZFeGglF5MVb8oi8ie8ecBvqK6OwwGvp3Mrufj4R9f gwTIgyr9An7iroBpuFdP4pCvSv54rbsHMadaNcOX2Oks/h19TTOICxX6Iv3LinlyE9QvOv+tbGx/L wTcT5umDxfJ4bBZWN9TxcctGh0UQpm3mRZ4XmF3h5po3lGR7yRCUFQw2uBAZRzDswWic5we1XzcwF /SAvFr1DLgt6bXlrFp4P21KqJpRkog5J4b+9kw2+DpFOJNuHjlhk466pmK9RtnC8VpIwnGyBr2P/L ry9AY69w==; Received: from authenticated user by stravinsky.debian.org with esmtpsa (TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim 4.94.2) (envelope-from ) id 1vltWK-001urn-5X; Fri, 30 Jan 2026 18:47:04 +0000 From: Breno Leitao Date: Fri, 30 Jan 2026 10:46:19 -0800 Subject: [PATCH net-next RFC 3/3] netlink: convert to getsockopt_iter Precedence: bulk X-Mailing-List: io-uring@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260130-getsockopt-v1-3-9154fcff6f95@debian.org> References: <20260130-getsockopt-v1-0-9154fcff6f95@debian.org> In-Reply-To: <20260130-getsockopt-v1-0-9154fcff6f95@debian.org> To: "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Simon Horman , Kuniyuki Iwashima , Willem de Bruijn , metze@samba.org, axboe@kernel.dk, Stanislav Fomichev Cc: io-uring@vger.kernel.org, bpf@vger.kernel.org, netdev@vger.kernel.org, Linus Torvalds , linux-kernel@vger.kernel.org, kernel-team@meta.com, Breno Leitao X-Mailer: b4 0.15-dev-f4305 X-Developer-Signature: v=1; a=openpgp-sha256; l=3397; i=leitao@debian.org; h=from:subject:message-id; bh=IVnLhnrcy/3xPEQctLWhlsnsImXX6rsH2GP1mnkmDNQ=; b=owEBbQKS/ZANAwAIATWjk5/8eHdtAcsmYgBpfPyU2OZHI4M0lCr3semqght57TV1hos0Fo3WE c1nHQfKtcOJAjMEAAEIAB0WIQSshTmm6PRnAspKQ5s1o5Of/Hh3bQUCaXz8lAAKCRA1o5Of/Hh3 bQ4lEACRll/JUEMJtdVPtrX+RF5bS7TQWHv7YtDd+8lAJdwtts5jliTofGG4ukbpoQbE4pRKcmL N/9T9SNairfNx6pRssn8tdoyNfc2TICWLatqB057ecdFQqlbWWefHLy4Jycya/yZUIQap+S3roY vR0L2UggKugpnVKUZ9+dAA4uYhYkCfVlS/SY4VU4Bk2NHNDCJvllMiGXsi71Bv2Pq7MirYfw/uv xiblpCNa5UEKDsIbIKV/sobPtejFcU50xdAtoxDBv2shqH6xsO0i3NxzhNBDxuJ6+ufHizF0M1Q zrbl+57gijjx5LAREzuKi2WQAPF7uDsNb2Tvsalu+PAD8JRZ7YznHF1L1PzPbqnoWs3OPIcjGt+ xNcJyKiVgsbt5Pv6S1jqDc6xAL5LWxhgAhzAvPTX/SELvDNREw+K+cpSI+z9fSWKPCXonVFoFTJ jGCQ6XOInJel7qW1TpyKx5prRb9mVwyWxC/RV4pjjA2qR4jWSGQ8BdRysIMGBBc1ag7w0abTwFD K7scjnQ7i3JMdCkzk4VNJROLa+khmlxqU6rF+iJEVB+Qe7gGJWU52UiApPVoc9+pHLnOLR/ZPYF Tpx8H3BUSXqEYGONXfRZKraJkRpzAK9GIMCiXVrgUzXLcH4KihTVihsECbhYcLvmEH0sGkpQknh pios0YQFtQXxG+Q== X-Developer-Key: i=leitao@debian.org; a=openpgp; fpr=AC8539A6E8F46702CA4A439B35A3939FFC78776D X-Debian-User: leitao Convert netlink's getsockopt implementation to use the new getsockopt_iter callback with sockopt_t. Key changes: - Replace (char __user *optval, int __user *optlen) with sockopt_t *opt - Use opt->optlen for buffer length (input) and returned size (output) - Use copy_to_iter() instead of put_user()/copy_to_user() The optlen field allows callbacks to return a specific length value independent of the bytes written via copy_to_iter(). This enables io_uring to call netlink's getsockopt with kernel buffers. Signed-off-by: Breno Leitao --- net/netlink/af_netlink.c | 22 ++++++++++++---------- 1 file changed, 12 insertions(+), 10 deletions(-) diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c index 8e5151f0c6e46..8a195eb1ef761 100644 --- a/net/netlink/af_netlink.c +++ b/net/netlink/af_netlink.c @@ -39,6 +39,7 @@ #include #include #include +#include #include #include #include @@ -1716,7 +1717,7 @@ static int netlink_setsockopt(struct socket *sock, int level, int optname, } static int netlink_getsockopt(struct socket *sock, int level, int optname, - char __user *optval, int __user *optlen) + sockopt_t *opt) { struct sock *sk = sock->sk; struct netlink_sock *nlk = nlk_sk(sk); @@ -1726,8 +1727,7 @@ static int netlink_getsockopt(struct socket *sock, int level, int optname, if (level != SOL_NETLINK) return -ENOPROTOOPT; - if (get_user(len, optlen)) - return -EFAULT; + len = opt->optlen; if (len < 0) return -EINVAL; @@ -1743,6 +1743,8 @@ static int netlink_getsockopt(struct socket *sock, int level, int optname, break; case NETLINK_LIST_MEMBERSHIPS: { int pos, idx, shift, err = 0; + u32 group_val; + size_t size; netlink_lock_table(); for (pos = 0; pos * 8 < nlk->ngroups; pos += sizeof(u32)) { @@ -1751,14 +1753,14 @@ static int netlink_getsockopt(struct socket *sock, int level, int optname, idx = pos / sizeof(unsigned long); shift = (pos % sizeof(unsigned long)) * 8; - if (put_user((u32)(nlk->groups[idx] >> shift), - (u32 __user *)(optval + pos))) { + group_val = (u32)(nlk->groups[idx] >> shift); + size = copy_to_iter(&group_val, sizeof(group_val), &opt->iter); + if (size != sizeof(group_val)) { err = -EFAULT; break; } } - if (put_user(ALIGN(BITS_TO_BYTES(nlk->ngroups), sizeof(u32)), optlen)) - err = -EFAULT; + opt->optlen = ALIGN(BITS_TO_BYTES(nlk->ngroups), sizeof(u32)); netlink_unlock_table(); return err; } @@ -1784,10 +1786,10 @@ static int netlink_getsockopt(struct socket *sock, int level, int optname, len = sizeof(int); val = test_bit(flag, &nlk->flags); - if (put_user(len, optlen) || - copy_to_user(optval, &val, len)) + if (copy_to_iter(&val, len, &opt->iter) != len) return -EFAULT; + opt->optlen = sizeof(int); return 0; } @@ -2813,7 +2815,7 @@ static const struct proto_ops netlink_ops = { .listen = sock_no_listen, .shutdown = sock_no_shutdown, .setsockopt = netlink_setsockopt, - .getsockopt = netlink_getsockopt, + .getsockopt_iter = netlink_getsockopt, .sendmsg = netlink_sendmsg, .recvmsg = netlink_recvmsg, .mmap = sock_no_mmap, -- 2.47.3