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 86BD14ADD91; Fri, 5 Jun 2026 10:32:00 +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=1780655526; cv=none; b=DcefUCIWDwNFR30w3msZobhTddwHiyHikc8R++UmVQ3JOHuPp5KGaZNlHoRF1IGXTK8tHy63BhlUEssa5Y24VKWVDoO0J2Jcz2ZxCNRMphiIRv7210Sh9Z/4fUCh+1ukRyM7nqVYwGwLDnquO9v1S878LsbP8wNBcS+prs4zj3o= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780655526; c=relaxed/simple; bh=4JzxiyHuzVHV5u6xPLo9a96EavCnG+zUg49sD/rGMvI=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=t8VYUA9W5GhrGnNdi+f7nNd1n8aBoSOHrDH21D+SRQ1+yfrE8lz2QXJIiVoAFh1tRwdSINA/xZmI/y3R+M+ALUzFqFgTTcxcsv1Pzo6g3GlTHl86EN5qyoPpIJaF7aho1l2oXISo569Bq6Q+gsKpTR+M4wLjjw3BEIp9pO9WY5w= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=debian.org; spf=pass smtp.mailfrom=debian.org; dkim=pass (2048-bit key) header.d=debian.org header.i=@debian.org header.b=gFB8rLUi; arc=none smtp.client-ip=82.195.75.108 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=debian.org Authentication-Results: smtp.subspace.kernel.org; spf=pass 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="gFB8rLUi" 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=hz7RK7vwPIuok63s9GZ4PpfT4BdFxPOdoyp+D6Hshek=; b=gFB8rLUiKwhKNLuk1v5vyhI+fY yFrancLNEruQ+LUh94AtzRl/WZUFYHEJVkzHesOHExSFdTghhE5phL7GhYbQ8xV2fxGaGpo0drjHK oVbKjzeqhd83CIrT907Yx3I6SCw1JYrwYJHPdV/o43wGOLCXn68cpH1/2G4VSAsEoV0DX4VZATc9Z rsJslc8+TFsxqhq99cc8AgeffOf4boHlRrbiPrXhwLvnhYPd+x2IAq+LM3bkoI6NfTPGZpHCkvKC1 6RJAdLsloo18OMTlVlCw+/mftGwIlDBleabgl22nWcLBXywRzwzPTs1F2B1e1j3qYOLTUiwKTfNmQ 3GmfnX8A==; Received: from authenticated-user by stravinsky.debian.org with esmtpsa (TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim 4.96) (envelope-from ) id 1wVRqI-005EFA-1u; Fri, 05 Jun 2026 10:31:58 +0000 From: Breno Leitao Date: Fri, 05 Jun 2026 03:31:40 -0700 Subject: [PATCH net-next v2 3/3] rds: convert to getsockopt_iter Precedence: bulk X-Mailing-List: linux-kernel@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: <20260605-getsock_more-v2-3-80f38cdb8706@debian.org> References: <20260605-getsock_more-v2-0-80f38cdb8706@debian.org> In-Reply-To: <20260605-getsock_more-v2-0-80f38cdb8706@debian.org> To: Allison Henderson , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Simon Horman , Shuah Khan Cc: linux-kernel@vger.kernel.org, netdev@vger.kernel.org, linux-rdma@vger.kernel.org, rds-devel@oss.oracle.com, linux-kselftest@vger.kernel.org, Breno Leitao , kernel-team@meta.com X-Mailer: b4 0.14.3 X-Developer-Signature: v=1; a=openpgp-sha256; l=9081; i=leitao@debian.org; h=from:subject:message-id; bh=4JzxiyHuzVHV5u6xPLo9a96EavCnG+zUg49sD/rGMvI=; b=owEBbQKS/ZANAwAIATWjk5/8eHdtAcsmYgBqIqWNPsa6CpdJh4dvuEhZUZ8+jLGq5cBu0MEeG sKPw0LgBUyJAjMEAAEIAB0WIQSshTmm6PRnAspKQ5s1o5Of/Hh3bQUCaiKljQAKCRA1o5Of/Hh3 bQ91EACkyOJGyYbxqcqRFMP4CLI1rDkhLKBmc2Jqcz/2nKLJ/XMa2BiDP9wjpTwdjiqjY4rvCsj AFfa/qZE78VlUnP3VWid1QenRkzHFgr2u+AP80UK7PUsh5URErdShVmOccu4vc0JJArWyP+/YH0 hjWaCtx/GAO+EUGS5SpPV3suPWvykiVEVl2ifrlgUPuWbPHd6rKXLmATALzbX6afs3YXGyIjb4/ +JsbXs21/nBzYMZJu4KOkqGobDFiqoKgyF3WcXvq+s2EvEaPvmPdMRtg4elMhx4Ep8IXsbRPa1G LunlQCrW0BjtEg671mRyZ+6A8P8VoKyBfjocVyOiBaXikP1SXi+ieM45vmc5tC7RBorx6R+W6hF H/u8omYzrUbl/5m/TWB4m7ZXTSSLRmTZ7q5IsZ2d4ugONsrW+K/JRlyhpqvIKBp+B2d3dcDOw2W Hb8e7bY/knRqs1DYnet0RHTnyBM99/A5wD4tXUEuYSn6BBUp20EcIf1Iatt8DIZjP2r2wEsImhP xNWiPFYLwOBFtXyTD/sm8uGcV2ZWdOc/UnvTcftl2k4fDDoJr6QOzVuPidLj3tciGAqzIs3EYXG LuF+xleoOVCMk8LYg2O/pvonZ3kaNDOOnWRVBOdYVxJxcMSaOZeNyQD94paHJMClPZzKW2A+XsU RUqybvcSkxe2utQ== X-Developer-Key: i=leitao@debian.org; a=openpgp; fpr=AC8539A6E8F46702CA4A439B35A3939FFC78776D X-Debian-User: leitao Convert RDS socket'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 RDS_INFO_* snapshot path in rds_info_getsockopt() used to pin the userspace buffer with pin_user_pages_fast() on the raw optval address; the info producers then memcpy into those pages under a spinlock via kmap_atomic() and so must not fault. Obtain the same page array and starting offset from opt->iter_out with iov_iter_extract_pages(), which pins for write because iter_out is ITER_DEST. The page array is preallocated here (sized with iov_iter_npages()) and passed in, so iov_iter_extract_pages() fills it in place rather than allocating one for us; RDS therefore keeps ownership of the array on every return path and frees it itself. The rds_info_iterator / rds_info_copy machinery and all producer callbacks are unchanged. Kernel buffers (ITER_KVEC) are not page-backed in a way the info producers can use, so the RDS_INFO path returns -EOPNOTSUPP for them; this matches the previous behaviour, where a kernel-buffer getsockopt hit the WARN_ONCE() path in do_sock_getsockopt() and returned -EOPNOTSUPP. The simple RDS_RECVERR and SO_RDS_TRANSPORT options keep working for kernel buffers via copy_to_iter(). Signed-off-by: Breno Leitao --- net/rds/af_rds.c | 36 +++++++++++++++------------ net/rds/info.c | 76 ++++++++++++++++++++++++++++++++------------------------ net/rds/info.h | 3 +-- 3 files changed, 65 insertions(+), 50 deletions(-) diff --git a/net/rds/af_rds.c b/net/rds/af_rds.c index 6f4f9cf352bd..d5defe9172e3 100644 --- a/net/rds/af_rds.c +++ b/net/rds/af_rds.c @@ -37,6 +37,7 @@ #include #include #include +#include #include #include "rds.h" @@ -485,35 +486,36 @@ static int rds_setsockopt(struct socket *sock, int level, int optname, } static int rds_getsockopt(struct socket *sock, int level, int optname, - char __user *optval, int __user *optlen) + sockopt_t *opt) { struct rds_sock *rs = rds_sk_to_rs(sock->sk); int ret = -ENOPROTOOPT, len; int trans; + int val; if (level != SOL_RDS) goto out; - if (get_user(len, optlen)) { - ret = -EFAULT; - goto out; - } + len = opt->optlen; switch (optname) { case RDS_INFO_FIRST ... RDS_INFO_LAST: - ret = rds_info_getsockopt(sock, optname, optval, - optlen); + ret = rds_info_getsockopt(sock, optname, opt); break; case RDS_RECVERR: - if (len < sizeof(int)) + if (len < sizeof(int)) { ret = -EINVAL; - else - if (put_user(rs->rs_recverr, (int __user *) optval) || - put_user(sizeof(int), optlen)) + break; + } + val = rs->rs_recverr; + if (copy_to_iter(&val, sizeof(int), &opt->iter_out) != + sizeof(int)) { ret = -EFAULT; - else + } else { + opt->optlen = sizeof(int); ret = 0; + } break; case SO_RDS_TRANSPORT: if (len < sizeof(int)) { @@ -522,11 +524,13 @@ static int rds_getsockopt(struct socket *sock, int level, int optname, } trans = (rs->rs_transport ? rs->rs_transport->t_type : RDS_TRANS_NONE); /* unbound */ - if (put_user(trans, (int __user *)optval) || - put_user(sizeof(int), optlen)) + if (copy_to_iter(&trans, sizeof(int), &opt->iter_out) != + sizeof(int)) { ret = -EFAULT; - else + } else { + opt->optlen = sizeof(int); ret = 0; + } break; default: break; @@ -653,7 +657,7 @@ static const struct proto_ops rds_proto_ops = { .listen = sock_no_listen, .shutdown = sock_no_shutdown, .setsockopt = rds_setsockopt, - .getsockopt = rds_getsockopt, + .getsockopt_iter = rds_getsockopt, .sendmsg = rds_sendmsg, .recvmsg = rds_recvmsg, .mmap = sock_no_mmap, diff --git a/net/rds/info.c b/net/rds/info.c index 17061f6ff74e..21b32eb16559 100644 --- a/net/rds/info.c +++ b/net/rds/info.c @@ -35,6 +35,7 @@ #include #include #include +#include #include "rds.h" @@ -144,60 +145,68 @@ void rds_info_copy(struct rds_info_iterator *iter, void *data, EXPORT_SYMBOL_GPL(rds_info_copy); /* - * @optval points to the userspace buffer that the information snapshot - * will be copied into. - * - * @optlen on input is the size of the buffer in userspace. @optlen - * on output is the size of the requested snapshot in bytes. + * @opt->iter_out describes the buffer that the information snapshot will be + * copied into, and @opt->optlen is the size of that buffer on input. On + * output @opt->optlen is set to the size of the requested snapshot in bytes. * * This function returns -errno if there is a failure, particularly -ENOSPC - * if the given userspace buffer was not large enough to fit the snapshot. - * On success it returns the positive number of bytes of each array element - * in the snapshot. + * if the given buffer was not large enough to fit the snapshot. On success + * it returns the positive number of bytes of each array element in the + * snapshot. */ -int rds_info_getsockopt(struct socket *sock, int optname, char __user *optval, - int __user *optlen) +int rds_info_getsockopt(struct socket *sock, int optname, sockopt_t *opt) { struct rds_info_iterator iter; struct rds_info_lengths lens; unsigned long nr_pages = 0; - unsigned long start; rds_info_func func; struct page **pages = NULL; + size_t offset0 = 0; + int npages = 0; int ret; int len; int total; - if (get_user(len, optlen)) { - ret = -EFAULT; - goto out; - } + len = opt->optlen; /* check for all kinds of wrapping and the like */ - start = (unsigned long)optval; - if (len < 0 || len > INT_MAX - PAGE_SIZE + 1 || start + len < start) { + if (len < 0 || len > INT_MAX - PAGE_SIZE + 1) { ret = -EINVAL; goto out; } + /* The info producers write into the pages with kmap_atomic() while + * holding a spinlock, so they need a genuine page-backed user buffer. + */ + if (!user_backed_iter(&opt->iter_out)) { + ret = -EOPNOTSUPP; + goto out; + } + /* a 0 len call is just trying to probe its length */ if (len == 0) goto call_func; - nr_pages = (PAGE_ALIGN(start + len) - (start & PAGE_MASK)) - >> PAGE_SHIFT; - - pages = kmalloc_objs(struct page *, nr_pages); + /* + * Preallocate the page array and pass it in so that + * iov_iter_extract_pages() fills it in place rather than allocating + * one for us. Handing it a non-NULL array keeps ownership of the + * array with us on every return path, instead of depending on the + * iterator code to allocate and hand it back. + */ + npages = iov_iter_npages(&opt->iter_out, INT_MAX); + pages = kvmalloc_array(npages, sizeof(*pages), GFP_KERNEL); if (!pages) { ret = -ENOMEM; goto out; } - ret = pin_user_pages_fast(start, nr_pages, FOLL_WRITE, pages); - if (ret != nr_pages) { - if (ret > 0) - nr_pages = ret; - else - nr_pages = 0; + + ret = iov_iter_extract_pages(&opt->iter_out, &pages, len, npages, + 0, &offset0); + if (ret < 0) + goto out; + nr_pages = DIV_ROUND_UP(offset0 + ret, PAGE_SIZE); + if (ret != len) { ret = -EAGAIN; /* XXX ? */ goto out; } @@ -213,7 +222,7 @@ int rds_info_getsockopt(struct socket *sock, int optname, char __user *optval, iter.pages = pages; iter.addr = NULL; - iter.offset = start & (PAGE_SIZE - 1); + iter.offset = offset0; func(sock, len, &iter, &lens); BUG_ON(lens.each == 0); @@ -230,13 +239,16 @@ int rds_info_getsockopt(struct socket *sock, int optname, char __user *optval, ret = lens.each; } - if (put_user(len, optlen)) - ret = -EFAULT; + opt->optlen = len; out: - if (pages) + /* + * iov_iter_extract_pages() pins only user-backed (ubuf) iters; + * iov_iter_extract_will_pin() reports whether an unpin is owed here. + */ + if (pages && iov_iter_extract_will_pin(&opt->iter_out)) unpin_user_pages_dirty_lock(pages, nr_pages, true); - kfree(pages); + kvfree(pages); return ret; } diff --git a/net/rds/info.h b/net/rds/info.h index a069b51c4679..1aab62ab6d00 100644 --- a/net/rds/info.h +++ b/net/rds/info.h @@ -21,8 +21,7 @@ typedef void (*rds_info_func)(struct socket *sock, unsigned int len, void rds_info_register_func(int optname, rds_info_func func); void rds_info_deregister_func(int optname, rds_info_func func); -int rds_info_getsockopt(struct socket *sock, int optname, char __user *optval, - int __user *optlen); +int rds_info_getsockopt(struct socket *sock, int optname, sockopt_t *opt); void rds_info_copy(struct rds_info_iterator *iter, void *data, unsigned long bytes); void rds_info_iter_unmap(struct rds_info_iterator *iter); -- 2.53.0-Meta