From patchwork Thu Sep 8 15:56:53 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pavel Begunkov X-Patchwork-Id: 12970292 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 91DE4C38145 for ; Thu, 8 Sep 2022 15:59:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229504AbiIHP7E (ORCPT ); Thu, 8 Sep 2022 11:59:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:32798 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230241AbiIHP7D (ORCPT ); Thu, 8 Sep 2022 11:59:03 -0400 Received: from mail-ed1-x52d.google.com (mail-ed1-x52d.google.com [IPv6:2a00:1450:4864:20::52d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7237C9CCCC for ; Thu, 8 Sep 2022 08:59:02 -0700 (PDT) Received: by mail-ed1-x52d.google.com with SMTP id e18so25067163edj.3 for ; Thu, 08 Sep 2022 08:59:02 -0700 (PDT) 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; bh=rNeqALpVAO/+TKzL6QzySY7His6uDpVJ/a3IOMvrhUM=; b=AyJxHXZx83BgPSTWK3GKzIaFp2W+0NGspXoBGvyw6T/q1LBFOtIaw+bdpWSjxiWjVQ UfRukVeuvSyJcFoAqkCF28mc5Aj7/E7/728L5xw7zqR1Yx2JsIX/yYG1gBAMMD3eA/y/ uNEejpOsbLnB+DikMd0hQxYm3A7bQQ5SHhvDA7tjLwXP9OMvtkUQNv0ETW1aMkvjnX3L N/O+Mv+zA2P+s+rZZxl/RUN4dRWw0CU1rrEvnNaPMc/5vZ9LoYVOyGdZV59xqS0kpEvv TIXpJCrRZxs3V2sDja0foO21DHKtiJ26NUw+S+KhjlZC9qfeac1VUMlO8KhnvrF0SWjM D2Vw== 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; bh=rNeqALpVAO/+TKzL6QzySY7His6uDpVJ/a3IOMvrhUM=; b=XyUwwdIZWRiMWlofP05eL08vG+IldzCtl0im/e4eG1LSfUP1pWTtq0VbaP6s4KxPqG m07IQYJmDz6VenB4w2MR+VxwtTrRhZABxJx9yBxmK3I4Gx/ZpzkSeXPAbueruro5ehku qx+9Hv2ouo4vbjGmZeHG08SXMehZJhnrsQb2SbeB5cMtwZJvb5sEr+RzWQ+VVn36yQuT yd4W0MBkNBcOHPYpjLp21C5vHBboJWgw6qSK+k2HqRH/X5/KtvS4Dq7GJuU57lNWnsD3 TK/+s7Z66/Ic93izWOMBLORl8maavxRokrbeJlWUjhz+PR+W5cYIJ+sw1q9argGQgzuB PonA== X-Gm-Message-State: ACgBeo0fd+qXNdBBJa/2wkPn7GgpujeXPUZA34oH2CVr44wEiXRJxY8u 5pOy007RdkIQFjW9Pq8WynB5aw6TMHQ= X-Google-Smtp-Source: AA6agR7OFURyitmmo/k6yrCq72/O4j2DtjzIaBj7k51x0Ydc3s1R0/VQUz0lAa6w3nlIr5a4BZmPVg== X-Received: by 2002:aa7:c458:0:b0:44e:9078:5712 with SMTP id n24-20020aa7c458000000b0044e90785712mr8012745edr.25.1662652740765; Thu, 08 Sep 2022 08:59:00 -0700 (PDT) Received: from 127.0.0.1localhost.com ([2620:10d:c092:600::2:cfb9]) by smtp.gmail.com with ESMTPSA id q26-20020a1709060e5a00b0073872f367cesm1392503eji.112.2022.09.08.08.59.00 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 08 Sep 2022 08:59:00 -0700 (PDT) From: Pavel Begunkov To: io-uring@vger.kernel.org Cc: Jens Axboe , asml.silence@gmail.com, Dylan Yudaken Subject: [PATCH 2/6] io_uring: disallow defer-tw run w/ no submitters Date: Thu, 8 Sep 2022 16:56:53 +0100 Message-Id: X-Mailer: git-send-email 2.37.2 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org We try to restrict CQ waiters when IORING_SETUP_DEFER_TASKRUN is set, but if nothing has been submitted yet it'll allow any waiter, which violates the contract. Fixes: dacbb30102689 ("io_uring: add IORING_SETUP_DEFER_TASKRUN") Signed-off-by: Pavel Begunkov Reviewed-by: Dylan Yudaken --- io_uring/io_uring.c | 7 +------ io_uring/io_uring.h | 9 ++------- 2 files changed, 3 insertions(+), 13 deletions(-) diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c index dc6f64ecd926..7f60d384e917 100644 --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -1169,13 +1169,8 @@ int __io_run_local_work(struct io_ring_ctx *ctx, bool locked) int ret; unsigned int loops = 1; - if (unlikely(ctx->submitter_task != current)) { - /* maybe this is before any submissions */ - if (!ctx->submitter_task) - return 0; - + if (unlikely(ctx->submitter_task != current)) return -EEXIST; - } node = io_llist_xchg(&ctx->work_llist, &fake); ret = 0; diff --git a/io_uring/io_uring.h b/io_uring/io_uring.h index 4eea0836170e..d38173b9ac19 100644 --- a/io_uring/io_uring.h +++ b/io_uring/io_uring.h @@ -331,13 +331,8 @@ static inline struct io_kiocb *io_alloc_req(struct io_ring_ctx *ctx) static inline bool io_allowed_run_tw(struct io_ring_ctx *ctx) { - if (!(ctx->flags & IORING_SETUP_DEFER_TASKRUN)) - return true; - if (unlikely(ctx->submitter_task != current)) { - /* maybe this is before any submissions */ - return !ctx->submitter_task; - } - return true; + return likely(!(ctx->flags & IORING_SETUP_DEFER_TASKRUN) || + ctx->submitter_task == current); } #endif