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 02410C433FE for ; Thu, 3 Nov 2022 05:41:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230089AbiKCFl0 (ORCPT ); Thu, 3 Nov 2022 01:41:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:32810 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229733AbiKCFlZ (ORCPT ); Thu, 3 Nov 2022 01:41:25 -0400 Received: from mail-pg1-x52c.google.com (mail-pg1-x52c.google.com [IPv6:2607:f8b0:4864:20::52c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7B0EA140FA; Wed, 2 Nov 2022 22:41:24 -0700 (PDT) Received: by mail-pg1-x52c.google.com with SMTP id v3so773595pgh.4; Wed, 02 Nov 2022 22:41:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:subject:references :in-reply-to:message-id:cc:to:from:date:from:to:cc:subject:date :message-id:reply-to; bh=Nvmd2WGiE7UyWMF/jvLSucjNrRcSgOhjrSAbsSDYxL4=; b=D5u5OZ+FQqZU3D1YeYwRPTgODYNKyCDz1ONJpJA2536owqYeZIW4jIyshyXB80Oye3 oHpQwqnEE4Eg94lrNOuFH19D/lI0D4R4l0ALeatWFby7fHwnOko96yi395CsZZo88nmB EsRVFkT8WRXpxtbezz/sn/XvJBCXVMoSPrNURsU4kL7sZR0WdoZ8aYqTNNzMiJyEYDnB kfw2hFHyy8oUacr6XxCIkos7HrwfPZHF+mwc1RhEj0Zt/uVxTwcxiYUEU8BDVr+cOUef QhYnSyoEousjgP7C0kWKgxRPNZA6ymD/JzsibjeI3IdKVsLqxusG1Xg0lRnzEy4nNEaK Sxag== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:subject:references :in-reply-to:message-id:cc:to:from:date:x-gm-message-state:from:to :cc:subject:date:message-id:reply-to; bh=Nvmd2WGiE7UyWMF/jvLSucjNrRcSgOhjrSAbsSDYxL4=; b=IGf4ORnqLUuYp3at2GLjGdSMQi3A/seZvRAKKu8rU8HvmtMr5hsLVx2AAi5dhzrXyC Jn2OnoqU6fEG55DzRH/3cya2tdWWHteFOtYOI1/JH+pwUa9cILviFRPhdcJs7uJ7Ufek 4L79q8nZ5DSDcDEaxtu6/qeBnDRPXtoKielk8yHIgPqEzyo+HgpBsMZB2qocQ+ewdnv+ wxEAAsSbnSqmaoBwO17tI0Bo03p1lfnCpVD+ima6qbUJTrhgQ5ZO+QH4/vn+z2n2sqip hYrW9AQdv5yLV5Px4JyZo3nN3DehxX929lE8Ec94phTcusM6ae74MnEoNMO9G3iQmjhJ l5+g== X-Gm-Message-State: ACrzQf3yDEriVwUv8NwvEmoCi5RBUaoKh/tkEE7ZADEgLQWwazOHG0mI wqqDP6Lz2UUCcwE/caIuw6M= X-Google-Smtp-Source: AMsMyM4Q0iqZ13zDWJF4Iz9gcY8aADEivbBaTBwy7kL3qrOSKf480wNWVVu9fmyJd9Z7+GXntbjVRg== X-Received: by 2002:a63:5341:0:b0:46f:d05d:55cf with SMTP id t1-20020a635341000000b0046fd05d55cfmr15145519pgl.356.1667454083917; Wed, 02 Nov 2022 22:41:23 -0700 (PDT) Received: from localhost ([98.97.41.13]) by smtp.gmail.com with ESMTPSA id w24-20020aa79558000000b0056e15b7138esm2328126pfq.157.2022.11.02.22.41.22 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 02 Nov 2022 22:41:23 -0700 (PDT) Date: Wed, 02 Nov 2022 22:41:21 -0700 From: John Fastabend To: Cong Wang , netdev@vger.kernel.org Cc: bpf@vger.kernel.org, Cong Wang , Stanislav Fomichev , John Fastabend , Jakub Sitnicki Message-ID: <636354819110e_a055820897@john.notmuch> In-Reply-To: <20221102043417.279409-1-xiyou.wangcong@gmail.com> References: <20221102043417.279409-1-xiyou.wangcong@gmail.com> Subject: RE: [Patch bpf v2] sock_map: move cancel_work_sync() out of sock lock Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Cong Wang wrote: > From: Cong Wang > > Stanislav reported a lockdep warning, which is caused by the > cancel_work_sync() called inside sock_map_close(), as analyzed > below by Jakub: > > psock->work.func = sk_psock_backlog() > ACQUIRE psock->work_mutex > sk_psock_handle_skb() > skb_send_sock() > __skb_send_sock() > sendpage_unlocked() > kernel_sendpage() > sock->ops->sendpage = inet_sendpage() > sk->sk_prot->sendpage = tcp_sendpage() > ACQUIRE sk->sk_lock > tcp_sendpage_locked() > RELEASE sk->sk_lock > RELEASE psock->work_mutex > > sock_map_close() > ACQUIRE sk->sk_lock > sk_psock_stop() > sk_psock_clear_state(psock, SK_PSOCK_TX_ENABLED) > cancel_work_sync() > __cancel_work_timer() > __flush_work() > // wait for psock->work to finish > RELEASE sk->sk_lock > > We can move the cancel_work_sync() out of the sock lock protection, > but still before saved_close() was called. > > Fixes: 799aa7f98d53 ("skmsg: Avoid lock_sock() in sk_psock_backlog()") > Reported-by: Stanislav Fomichev > Cc: John Fastabend > Cc: Jakub Sitnicki > Signed-off-by: Cong Wang > --- LGTM. Thanks. Acked-by: John Fastabend