From patchwork Fri Jan 20 16:38:05 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pavel Begunkov X-Patchwork-Id: 13110208 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A8BADC27C7C for ; Fri, 20 Jan 2023 16:39:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229459AbjATQjG (ORCPT ); Fri, 20 Jan 2023 11:39:06 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49086 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229495AbjATQjG (ORCPT ); Fri, 20 Jan 2023 11:39:06 -0500 Received: from mail-ej1-x631.google.com (mail-ej1-x631.google.com [IPv6:2a00:1450:4864:20::631]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F1CEB6580 for ; Fri, 20 Jan 2023 08:39:02 -0800 (PST) Received: by mail-ej1-x631.google.com with SMTP id az20so15417340ejc.1 for ; Fri, 20 Jan 2023 08:39:02 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=kNXtuGs/ChtdEeAKTWqgirpCrA/uohpZGq3JkDE5JVo=; b=QwaOFeHQRLJYVwVgP2Q4/ZaFlTczZHXPK40kI2LmnWox2UuFIoc/PX+sXWh6PA6sIL TLiTPVWo6VBwW2oi9dmo2zIlZb25fg7iD4ZeiN2+H9hV6De+WJ/Lh1a58GWNUQqfm+cW 2OKosn74L+tiMJjROUmSctWENKeGRFNzq2T7OHPARvoAKZ3iQmjLcB/d77/3QWbBDE3M cRNKmX6uBFjaqQwUD6mAvuVtnOjsmUcY9SLMTBilBia/vTRJmqY+DvLBZ6+jtams6bbj 8Bf4QGhyF8GKS/kIZIe3xA9KutEW7KxmcfHfMaJLSHYAwSDlkqa9UdJyql7yvPQcszwO 7h0A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=kNXtuGs/ChtdEeAKTWqgirpCrA/uohpZGq3JkDE5JVo=; b=sTOiqwtdZI/MpMH07udsm6O1MHBwMx+pPLDv5feYw7NN++jQDxqvr6DM4Vhd3yMpSB BiGYD7STpuB5KmqxbH7HBoTx77PUXeLxNuSF3TYxmAAv1XMSOgbn+fnLcESbC7JpRKTn mAmoX5zJbCiupxUweIk6jUtQcm+xfqTuvLNoPZafOP5snZ1UkaaP3anClHFkaxu+igx/ xduXY1kEQAPy0ltMbA7ghG0nIGqp4kMRDPYL5BfXO4pc1KuVKNAyQpPRRhLjU9VUfMZl JK2x/WE4PD4sZHDJrVOWvBT0JOMxIVTexC32TjnCk7NqKCITLyGrnJHboAOQ6rsDgXMw 3lxw== X-Gm-Message-State: AFqh2kpoJDEEkTz5RPnCdadmi26BH3yFQ68jIAe8IGcJxzOBfGnaIdBi 7SgwaefnejctvMMKko8ZlpthKgR/5MY= X-Google-Smtp-Source: AMrXdXsfipxzwCIgIxJEqEH8FYEbqzCX/Ekj1LVyuT7cykB1ICM1Vki7r2a1FxlV48shdvKU8Ezp4A== X-Received: by 2002:a17:906:6b8f:b0:877:74e6:67a4 with SMTP id l15-20020a1709066b8f00b0087774e667a4mr6320336ejr.47.1674232740645; Fri, 20 Jan 2023 08:39:00 -0800 (PST) Received: from 127.com ([2620:10d:c092:600::2:4670]) by smtp.gmail.com with ESMTPSA id t27-20020a170906179b00b008762e2b7004sm4702124eje.208.2023.01.20.08.39.00 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 20 Jan 2023 08:39:00 -0800 (PST) From: Pavel Begunkov To: io-uring@vger.kernel.org Cc: Jens Axboe , asml.silence@gmail.com Subject: [PATCH for-6.2 v2 1/3] io_uring/msg_ring: fix flagging remote execution Date: Fri, 20 Jan 2023 16:38:05 +0000 Message-Id: X-Mailer: git-send-email 2.38.1 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org There is a couple of problems with queueing a tw in io_msg_ring_data() for remote execution. First, once we queue it the target ring can go away and so setting IORING_SQ_TASKRUN there is not safe. Secondly, the userspace might not expect IORING_SQ_TASKRUN. Extract a helper and uniformly use TWA_SIGNAL without TWA_SIGNAL_NO_IPI tricks for now, just as it was done in the original patch. Fixes: 6d043ee1164ca ("io_uring: do msg_ring in target task via tw") Signed-off-by: Pavel Begunkov --- io_uring/msg_ring.c | 40 +++++++++++++++++++++++----------------- 1 file changed, 23 insertions(+), 17 deletions(-) diff --git a/io_uring/msg_ring.c b/io_uring/msg_ring.c index a333781565d3..bb868447dcdf 100644 --- a/io_uring/msg_ring.c +++ b/io_uring/msg_ring.c @@ -58,6 +58,25 @@ void io_msg_ring_cleanup(struct io_kiocb *req) msg->src_file = NULL; } +static inline bool io_msg_need_remote(struct io_ring_ctx *target_ctx) +{ + if (!target_ctx->task_complete) + return false; + return current != target_ctx->submitter_task; +} + +static int io_msg_exec_remote(struct io_kiocb *req, task_work_func_t func) +{ + struct io_ring_ctx *ctx = req->file->private_data; + struct io_msg *msg = io_kiocb_to_cmd(req, struct io_msg); + + init_task_work(&msg->tw, func); + if (task_work_add(ctx->submitter_task, &msg->tw, TWA_SIGNAL)) + return -EOWNERDEAD; + + return IOU_ISSUE_SKIP_COMPLETE; +} + static void io_msg_tw_complete(struct callback_head *head) { struct io_msg *msg = container_of(head, struct io_msg, tw); @@ -96,15 +115,8 @@ static int io_msg_ring_data(struct io_kiocb *req, unsigned int issue_flags) if (msg->src_fd || msg->dst_fd || msg->flags) return -EINVAL; - if (target_ctx->task_complete && current != target_ctx->submitter_task) { - init_task_work(&msg->tw, io_msg_tw_complete); - if (task_work_add(target_ctx->submitter_task, &msg->tw, - TWA_SIGNAL_NO_IPI)) - return -EOWNERDEAD; - - atomic_or(IORING_SQ_TASKRUN, &target_ctx->rings->sq_flags); - return IOU_ISSUE_SKIP_COMPLETE; - } + if (io_msg_need_remote(target_ctx)) + return io_msg_exec_remote(req, io_msg_tw_complete); ret = -EOVERFLOW; if (target_ctx->flags & IORING_SETUP_IOPOLL) { @@ -202,14 +214,8 @@ static int io_msg_send_fd(struct io_kiocb *req, unsigned int issue_flags) req->flags |= REQ_F_NEED_CLEANUP; } - if (target_ctx->task_complete && current != target_ctx->submitter_task) { - init_task_work(&msg->tw, io_msg_tw_fd_complete); - if (task_work_add(target_ctx->submitter_task, &msg->tw, - TWA_SIGNAL)) - return -EOWNERDEAD; - - return IOU_ISSUE_SKIP_COMPLETE; - } + if (io_msg_need_remote(target_ctx)) + return io_msg_exec_remote(req, io_msg_tw_fd_complete); return io_msg_install_complete(req, issue_flags); }