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 X-Spam-Level: X-Spam-Status: No, score=-11.4 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_IN_DEF_DKIM_WL autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 58F36C1975A for ; Thu, 12 Mar 2020 14:06:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 269422071B for ; Thu, 12 Mar 2020 14:06:09 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="Y2GOS5ow" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727560AbgCLOGI (ORCPT ); Thu, 12 Mar 2020 10:06:08 -0400 Received: from mail-ot1-f66.google.com ([209.85.210.66]:44293 "EHLO mail-ot1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727123AbgCLOGI (ORCPT ); Thu, 12 Mar 2020 10:06:08 -0400 Received: by mail-ot1-f66.google.com with SMTP id a49so3554936otc.11 for ; Thu, 12 Mar 2020 07:06:07 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=HLTQ7SxBP998ZRyt/spl3MxmTSGFK+HueOsxsAmc57o=; b=Y2GOS5ow5Z2ATB76Xuh3T3CMKkXp5qVt41XsjiE6pQGBXTSgEBhbAcwXb717V9+AKw BElLgBjrApQXE7b61mevES4kmBQzO5+jLlw8D3cgtsqv9S+/TnzeISX8omqk9KnvdHT7 FQNz7ALIo6NSVs2E53XNeu+8zDW2lTBi3ANGUB8w3Ua9XKJ321a/ob4BOnH7KF54D1+I OQrnmWRpMI72Y9SJgafKstMXjjOlNlCQwFFLXAt/X/6HyWc3C7nilLQ/4fmdMqlR8yUw B0dSA4kWeWY8mNa1qvZjcca/CLW12Cq5iYL86BkhalfzpghJPJMt7AsEr9Ie6WzpPR2B MnQQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=HLTQ7SxBP998ZRyt/spl3MxmTSGFK+HueOsxsAmc57o=; b=nWwC/8G+UeljOeeqpXaO4ecvGE7Am6iT2hwaFLV32nhLmEBUJ3B5/UGHrvi5Nqt2ro dbzcVD+umWbOzGc7QXNL082xvA0qfruYj8oSguT2ursp44otNUhuUPznq+EqD25IaV8Q 8iYUaForUVARmH+VlJONQHvvWHxGeNzbHg4joLdbCQwz4YpvNM1HUHqiqGyuGFCoTtp3 VRdh995PKsUdiQccUNyu9O7vyaYXfHv4/xg570IEkkKXh7K+hSAPFOhfLzVKUBN6JIcn kNDmHJYWkDOVAdpfKl8/gYy237SJ47qwrfCBe3twbsxGmGyUmKARhhq4idXZA4SYqVl1 b9wQ== X-Gm-Message-State: ANhLgQ0+Y1NZ4lpbYM6rRHkq6yX30/Ub3kSQPK0sA7yEXlDSiLM9vA5t WtAySGJdB0zjiLCp6/G5Wxlnjeu7e4ULHLAILf8yDg== X-Google-Smtp-Source: ADFU+vuAeU13QzGVA33BSC1Tpqr+aYm8tNHddgFpAfKTwXQWbSyNcgyhErv8/Luep3EXUE+e7LH6oja9a0UoqI403zE= X-Received: by 2002:a9d:6c99:: with SMTP id c25mr6060360otr.124.1584021966391; Thu, 12 Mar 2020 07:06:06 -0700 (PDT) MIME-Version: 1.0 References: <20200310051606.33121-1-shakeelb@google.com> <20200310051606.33121-2-shakeelb@google.com> <1584021811.7365.180.camel@lca.pw> In-Reply-To: <1584021811.7365.180.camel@lca.pw> From: Shakeel Butt Date: Thu, 12 Mar 2020 07:05:55 -0700 Message-ID: Subject: Re: [PATCH v4 2/2] net: memcg: late association of sock to memcg To: Qian Cai Cc: Eric Dumazet , Roman Gushchin , Johannes Weiner , Michal Hocko , Greg Thelen , Andrew Morton , "David S . Miller" , Alexey Kuznetsov , Hideaki YOSHIFUJI , netdev , Linux MM , Cgroups , LKML Content-Type: text/plain; charset="UTF-8" Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Thu, Mar 12, 2020 at 7:03 AM Qian Cai wrote: > > On Mon, 2020-03-09 at 22:16 -0700, Shakeel Butt wrote: > > diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c > > index a4db79b1b643..65a3b2565102 100644 > > --- a/net/ipv4/inet_connection_sock.c > > +++ b/net/ipv4/inet_connection_sock.c > > @@ -482,6 +482,26 @@ struct sock *inet_csk_accept(struct sock *sk, int flags, int *err, bool kern) > > } > > spin_unlock_bh(&queue->fastopenq.lock); > > } > > + > > + if (mem_cgroup_sockets_enabled) { > > + int amt; > > + > > + /* atomically get the memory usage, set and charge the > > + * sk->sk_memcg. > > + */ > > + lock_sock(newsk); > > Here we have a deadlock, It's a missing lockdep annotation. Eric already has a patch in progress to fix this and another typo in the original patch. > > [ 362.620977][ T4106] WARNING: possible recursive locking detected > [ 362.626983][ T4106] 5.6.0-rc5-next-20200312+ #5 Tainted: G L > [ 362.633941][ T4106] -------------------------------------------- > [ 362.639944][ T4106] sshd/4106 is trying to acquire lock: > [ 362.645251][ T4106] 7bff008a2eae6330 (sk_lock-AF_INET){+.+.}, at: > inet_csk_accept+0x370/0x45c > inet_csk_accept at net/ipv4/inet_connection_sock.c:497 > [ 362.653791][ T4106] > [ 362.653791][ T4106] but task is already holding lock: > [ 362.661007][ T4106] c0ff008a2eae9430 (sk_lock-AF_INET){+.+.}, at: > inet_csk_accept+0x48/0x45c > inet_csk_accept at net/ipv4/inet_connection_sock.c:451 > [ 362.669452][ T4106] > [ 362.669452][ T4106] other info that might help us debug this: > [ 362.677364][ T4106] Possible unsafe locking scenario: > [ 362.677364][ T4106] > [ 362.684666][ T4106] CPU0 > [ 362.687801][ T4106] ---- > [ 362.690937][ T4106] lock(sk_lock-AF_INET); > [ 362.695204][ T4106] lock(sk_lock-AF_INET); > [ 362.699472][ T4106] > [ 362.699472][ T4106] *** DEADLOCK *** > [ 362.699472][ T4106] > [ 362.707469][ T4106] May be due to missing lock nesting notation > [ 362.707469][ T4106] > [ 362.715643][ T4106] 1 lock held by sshd/4106: > [ 362.719993][ T4106] #0: c0ff008a2eae9430 (sk_lock-AF_INET){+.+.}, at: > inet_csk_accept+0x48/0x45c > [ 362.728874][ T4106] > [ 362.728874][ T4106] stack backtrace: > [ 362.734622][ T4106] CPU: 22 PID: 4106 Comm: sshd Tainted: > G L 5.6.0-rc5-next-20200312+ #5 > [ 362.744096][ T4106] Hardware name: HPE Apollo > 70 /C01_APACHE_MB , BIOS L50_5.13_1.11 06/18/2019 > [ 362.754525][ T4106] Call trace: > [ 362.757667][ T4106] dump_backtrace+0x0/0x2c8 > [ 362.762022][ T4106] show_stack+0x20/0x2c > [ 362.766032][ T4106] dump_stack+0xe8/0x150 > [ 362.770128][ T4106] validate_chain+0x2f08/0x35e0 > [ 362.774830][ T4106] __lock_acquire+0x868/0xc2c > [ 362.779358][ T4106] lock_acquire+0x320/0x360 > [ 362.783715][ T4106] lock_sock_nested+0x9c/0xd8 > [ 362.788243][ T4106] inet_csk_accept+0x370/0x45c > [ 362.792861][ T4106] inet_accept+0x80/0x1cc > [ 362.797045][ T4106] __sys_accept4_file+0x1b0/0x2bc > [ 362.801921][ T4106] __arm64_sys_accept+0x74/0xc8 > [ 362.806625][ T4106] do_el0_svc+0x170/0x240 > [ 362.810807][ T4106] el0_sync_handler+0x150/0x250 > [ 362.815509][ T4106] el0_sync+0x164/0x180 > > > > + > > + /* The sk has not been accepted yet, no need to look at > > + * sk->sk_wmem_queued. > > + */ > > + amt = sk_mem_pages(newsk->sk_forward_alloc + > > + atomic_read(&sk->sk_rmem_alloc)); > > + mem_cgroup_sk_alloc(newsk); > > + if (newsk->sk_memcg && amt) > > + mem_cgroup_charge_skmem(newsk->sk_memcg, amt); > > + > > + release_sock(newsk); > > + } > > out: > > release_sock(sk); > > if (req)