From mboxrd@z Thu Jan 1 00:00:00 1970 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 04A122F19AE; Thu, 3 Jul 2025 15:10:09 +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=1751555409; cv=none; b=Gxp6HulyjinPRDpuhotiUqqwkvbtM6MW2NZWcT5/n9fGc5NzOHr2+DKOOF18Q1bv9NeePIzoIRUaJomDvKEbQWHUviyJUPhuvfTbv3Ya1P/OpUnB+jyn7F3jpfgvHnubTggizRl+p4YZ3C1EPl6GjOMV4qiB7On49S9IlcnBUxg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751555409; c=relaxed/simple; bh=XIVHsuoes5Gf0juoYdFciX8hGrAAcA740uQ2Cpw5z+E=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=j/kh2xeOwUdDtZPn9XoS85RuzmA8ejdLJvlyy4GVA6dBxI5EACuWPQqOxsb2RGjDUTa4Bd7/JDds9sClOVO7TJaCgpKv8WxEtFzgxJqCxm4Z4otsgm6liq8ZWNSr3EOFEs8P8PtzuoOcJ0coYEI2IaUGwxdMf4/G5unSSoh4Ly8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=qNqzDPLB; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="qNqzDPLB" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8ECA1C4CEE3; Thu, 3 Jul 2025 15:10:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1751555408; bh=XIVHsuoes5Gf0juoYdFciX8hGrAAcA740uQ2Cpw5z+E=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qNqzDPLBTenXt94GKK1RnHrfWEcve1ZxpE110tGoHKlXYqLl2Wmg2KZxZmH73yVfc 4QDRu8JAWncSYbheDmkZEDI0y5aqDYzTqHsI7ZeQUqzoQZwkgyf2wTFksToki30T7A OPEkNJ/3IBAygrvfMYGPQv6Q37kkT3JrI4eds7uA= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Jens Axboe Subject: [PATCH 6.15 261/263] io_uring/kbuf: flag partial buffer mappings Date: Thu, 3 Jul 2025 16:43:01 +0200 Message-ID: <20250703144014.879353678@linuxfoundation.org> X-Mailer: git-send-email 2.50.0 In-Reply-To: <20250703144004.276210867@linuxfoundation.org> References: <20250703144004.276210867@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jens Axboe Commit 178b8ff66ff827c41b4fa105e9aabb99a0b5c537 upstream. A previous commit aborted mapping more for a non-incremental ring for bundle peeking, but depending on where in the process this peeking happened, it would not necessarily prevent a retry by the user. That can create gaps in the received/read data. Add struct buf_sel_arg->partial_map, which can pass this information back. The networking side can then map that to internal state and use it to gate retry as well. Since this necessitates a new flag, change io_sr_msg->retry to a retry_flags member, and store both the retry and partial map condition in there. Cc: stable@vger.kernel.org Fixes: 26ec15e4b0c1 ("io_uring/kbuf: don't truncate end buffer for multiple buffer peeks") Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman --- io_uring/kbuf.c | 1 + io_uring/kbuf.h | 1 + io_uring/net.c | 23 +++++++++++++++-------- 3 files changed, 17 insertions(+), 8 deletions(-) --- a/io_uring/kbuf.c +++ b/io_uring/kbuf.c @@ -271,6 +271,7 @@ static int io_ring_buffers_peek(struct i if (len > arg->max_len) { len = arg->max_len; if (!(bl->flags & IOBL_INC)) { + arg->partial_map = 1; if (iov != arg->iovs) break; buf->len = len; --- a/io_uring/kbuf.h +++ b/io_uring/kbuf.h @@ -55,6 +55,7 @@ struct buf_sel_arg { size_t max_len; unsigned short nr_iovs; unsigned short mode; + unsigned short partial_map; }; void __user *io_buffer_select(struct io_kiocb *req, size_t *len, --- a/io_uring/net.c +++ b/io_uring/net.c @@ -76,12 +76,17 @@ struct io_sr_msg { u16 flags; /* initialised and used only by !msg send variants */ u16 buf_group; - bool retry; + unsigned short retry_flags; void __user *msg_control; /* used only for send zerocopy */ struct io_kiocb *notif; }; +enum sr_retry_flags { + IO_SR_MSG_RETRY = 1, + IO_SR_MSG_PARTIAL_MAP = 2, +}; + /* * Number of times we'll try and do receives if there's more data. If we * exceed this limit, then add us to the back of the queue and retry from @@ -188,7 +193,7 @@ static inline void io_mshot_prep_retry(s req->flags &= ~REQ_F_BL_EMPTY; sr->done_io = 0; - sr->retry = false; + sr->retry_flags = 0; sr->len = 0; /* get from the provided buffer */ req->buf_index = sr->buf_group; } @@ -401,7 +406,7 @@ int io_sendmsg_prep(struct io_kiocb *req struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg); sr->done_io = 0; - sr->retry = false; + sr->retry_flags = 0; sr->len = READ_ONCE(sqe->len); sr->flags = READ_ONCE(sqe->ioprio); if (sr->flags & ~SENDMSG_FLAGS) @@ -759,7 +764,7 @@ int io_recvmsg_prep(struct io_kiocb *req struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg); sr->done_io = 0; - sr->retry = false; + sr->retry_flags = 0; if (unlikely(sqe->file_index || sqe->addr2)) return -EINVAL; @@ -831,7 +836,7 @@ static inline bool io_recv_finish(struct cflags |= io_put_kbufs(req, this_ret, io_bundle_nbufs(kmsg, this_ret), issue_flags); - if (sr->retry) + if (sr->retry_flags & IO_SR_MSG_RETRY) cflags = req->cqe.flags | (cflags & CQE_F_MASK); /* bundle with no more immediate buffers, we're done */ if (req->flags & REQ_F_BL_EMPTY) @@ -840,12 +845,12 @@ static inline bool io_recv_finish(struct * If more is available AND it was a full transfer, retry and * append to this one */ - if (!sr->retry && kmsg->msg.msg_inq > 1 && this_ret > 0 && + if (!sr->retry_flags && kmsg->msg.msg_inq > 1 && this_ret > 0 && !iov_iter_count(&kmsg->msg.msg_iter)) { req->cqe.flags = cflags & ~CQE_F_MASK; sr->len = kmsg->msg.msg_inq; sr->done_io += this_ret; - sr->retry = true; + sr->retry_flags |= IO_SR_MSG_RETRY; return false; } } else { @@ -1089,6 +1094,8 @@ static int io_recv_buf_select(struct io_ kmsg->vec.iovec = arg.iovs; req->flags |= REQ_F_NEED_CLEANUP; } + if (arg.partial_map) + sr->retry_flags |= IO_SR_MSG_PARTIAL_MAP; /* special case 1 vec, can be a fast path */ if (ret == 1) { @@ -1285,7 +1292,7 @@ int io_send_zc_prep(struct io_kiocb *req int ret; zc->done_io = 0; - zc->retry = false; + zc->retry_flags = 0; if (unlikely(READ_ONCE(sqe->__pad2[0]) || READ_ONCE(sqe->addr3))) return -EINVAL;