From mboxrd@z Thu Jan 1 00:00:00 1970 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 09D19C3527C for ; Mon, 7 Feb 2022 13:52:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1389208AbiBGNvW (ORCPT ); Mon, 7 Feb 2022 08:51:22 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41506 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1388363AbiBGNqu (ORCPT ); Mon, 7 Feb 2022 08:46:50 -0500 Received: from mail-pl1-x62b.google.com (mail-pl1-x62b.google.com [IPv6:2607:f8b0:4864:20::62b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D00E7C043181 for ; Mon, 7 Feb 2022 05:46:49 -0800 (PST) Received: by mail-pl1-x62b.google.com with SMTP id x4so3566277plb.4 for ; Mon, 07 Feb 2022 05:46:49 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20210112.gappssmtp.com; s=20210112; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=8ug9KpH6bIvmPFydrBBlGOiV1ojuh4o4EvlAVOtW+r8=; b=Ucb6NZccAO1goAXBmte2XO3+lvr0ZtNlsCU1niaB4QeCGfuaC+ZZ34xsjuiUZ34J8P /PnDKyDwwKZuyRevYLH0cVu+uCxqEht+7er+qya2op6bjdApe9jED//PHeQR5KhnvRSi o4CuIM7pIIeu74ADGEG1vVJsUXTxHgkEvPzxtrhogxoQg5Pgb1QV4Ds6kJhzGHEfj/Js X18y8WlvaeZpnMJicsHItS4pA/ToBOt7PEBsnu43DqRWFYqgaSwsjHYfF7nC2ZYrqTz+ K3FGWynLI1LQBD2ydHoPIv4f5Q2OU5bpE28FB9kpldJ0ng8rn0wtSRR/4J+59QLHhwRw 8fKQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=8ug9KpH6bIvmPFydrBBlGOiV1ojuh4o4EvlAVOtW+r8=; b=LsGTOx2ekGcWpy8owWOSivSypBUmNRlzG1WrIXyoDi3J8HtRYfaYaVB0xOUH4xOCea 8/sRfQL9CDYPzHTRKiRxPC4PIKTVzQewj2uIXlyO9WaFMy/oMIT4t8cAuyKlBpGaLtt0 1g24UPS0b+9A24fmBX2pTm7IPzhPXsi9HjthWislQpe94tetN0OSSKtvhznu/O055km5 AKD6xQ8blKVflKeYFUarIw+PW0UbK+niv13MsOW4k8AsQuW9V1T99Fzvo3cfobqCx5r1 cPmZIe0dTrlkdEE9ju7RmfyT85v5Nog6G6U5iad7nwpZN+dTsRjsjiXpcuqrnB6gr2iS Gq9g== X-Gm-Message-State: AOAM530DrFs4mVdhYcGYjypmzg/FMSHMgfRKnmpa5WP3z4u/anVVX6h1 HT8+c3yqKrNYCSH58jLHCQipFA== X-Google-Smtp-Source: ABdhPJy9dgozjBf35cBNjjoa6rNFAeIyMjWTFI96ymPkw8SlosV4+0d7/rydA66/7FD2PEhtZhWwFA== X-Received: by 2002:a17:90a:f414:: with SMTP id ch20mr8409368pjb.146.1644241609260; Mon, 07 Feb 2022 05:46:49 -0800 (PST) Received: from [192.168.1.116] ([66.219.217.159]) by smtp.gmail.com with ESMTPSA id 198sm8378636pgg.4.2022.02.07.05.46.48 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 07 Feb 2022 05:46:48 -0800 (PST) Subject: Re: [PATCH] io_uring: unregister eventfd while holding lock when freeing ring ctx To: Usama Arif , io-uring@vger.kernel.org, asml.silence@gmail.com, linux-kernel@vger.kernel.org Cc: fam.zheng@bytedance.com, lkp@lists.01.org, lkp@intel.com, kernel test robot References: <20220207105040.2662467-1-usama.arif@bytedance.com> From: Jens Axboe Message-ID: <696e49fe-3d2e-da6c-2fc6-5d69bc7a60f9@kernel.dk> Date: Mon, 7 Feb 2022 06:46:46 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20220207105040.2662467-1-usama.arif@bytedance.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2/7/22 3:50 AM, Usama Arif wrote: > This is because ctx->io_ev_fd is rcu_dereference_protected using > ctx->uring_lock in io_eventfd_unregister. Not locking the function > resulted in suspicious RCU usage reported by kernel test robot. I'll fold this in with the change, thanks. -- Jens Axboe