Received: by 2002:a05:6902:102b:0:0:0:0 with SMTP id x11csp2574243ybt; Mon, 22 Jun 2020 01:41:18 -0700 (PDT) X-Google-Smtp-Source: ABdhPJyRP4wr18KNrd77MMVoz68sQYYfbDl3Qei4hB3saCfKZNGPbnMz8Pz/2j4yIHW78jwe3yvq X-Received: by 2002:a17:906:2c10:: with SMTP id e16mr8229593ejh.189.1592815277832; Mon, 22 Jun 2020 01:41:17 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1592815277; cv=none; d=google.com; s=arc-20160816; b=c+t26L4IInhlRoPKKF042A3e6YZh9exPVom7b9BwGzEapP7clUSoT9xA64BkqSiP5j YswAw/QrzeK/dHW1gU6awwwNi+fW6LHR/u0+6UTbExwsrpjywKAxgx78N8KpRIIaoJD6 UZnhS6gOGH8yx86HWvntV3dpo1qGoOq+X8X6gEHjhTKqqD2y+ghp0Z5O4h8+soIyiNiO 6tKoLAMOZH0D9wt9wYVKz6lcq/gV7BDeuiogpRe5koJfI2xnoquKxHW4EdRPSFqQtc1V toMatWxs3hixsAaG54cahiO/pF97fzJRzMJDBXsdLMaYT7gzoN7Dwy98u1YlHTmbFtYr Gxlw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:in-reply-to:content-disposition :mime-version:references:message-id:subject:cc:to:from:date; bh=LWYkeFI8FYQwqhCkHdutOCNZfdmc5ocUfVUdMOiQi00=; b=cUaXp+zISh6vZNKNeh4WRVzfvNlpsMs4kwFVBVx3pdc1wnfgvfiF3Enn455W6CbJ0V G9sXc5rKS2sxcA4BEVasq0jbSUnMXFxKUxI72GnTSkbvjFhbUBQbB2pEvtKoYKnYuo3d 7ow4nA64StdlKE2scjAuk1RnxvWJ0tJLAI+0mwwQLZbpRs89AYzOttJp9L0SkCWOCCe8 I7BlTTJA/vRNxIkWz7VkYZYzKOOTeEG8mqhfiAP1mDniscPiDrKC4PssZFc+BER2A9jV FzkuIFLW9Lp1yUMNmALmZ70FvX3rICLVo77Hrofjbittii0MZFmbfhtzyWL3h79Z/p9d U/ng== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id op23si585511ejb.694.2020.06.22.01.40.55; Mon, 22 Jun 2020 01:41:17 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726079AbgFVIjL (ORCPT + 99 others); Mon, 22 Jun 2020 04:39:11 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:59250 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725883AbgFVIjL (ORCPT ); Mon, 22 Jun 2020 04:39:11 -0400 Received: from ip5f5af08c.dynamic.kabel-deutschland.de ([95.90.240.140] helo=wittgenstein) by youngberry.canonical.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1jnHys-0005eB-CX; Mon, 22 Jun 2020 08:39:06 +0000 Date: Mon, 22 Jun 2020 10:39:05 +0200 From: Christian Brauner To: Oleg Nesterov Cc: Alexander Kapshuk , linux-kernel@vger.kernel.org, ebiederm@xmission.com, akpm@linux-foundation.org, liuzhiqiang26@huawei.com, joel@joelfernandes.org, paulmck@linux.vnet.ibm.com, asmadeus@codewreck.org, kernel test robot Subject: Re: [PATCH] kernel/signal.c: Export symbol __lock_task_sighand Message-ID: <20200622083905.c3nurmkbo5yhd6lj@wittgenstein> References: <20200621133704.77896-1-alexander.kapshuk@gmail.com> <20200622062527.GA6516@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20200622062527.GA6516@redhat.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jun 22, 2020 at 08:25:28AM +0200, Oleg Nesterov wrote: > On 06/21, Alexander Kapshuk wrote: > > > > Export symbol __lock_task_sighand, so it is accessible from code compiled > > as modules. > > This fixes the following modpost error: > > ERROR: modpost: "__lock_task_sighand" [net/9p/9pnet.ko] undefined! > > > > Where __lock_task_sighand is called via lock_task_sighand in net/9p/client.c > > See https://lore.kernel.org/lkml/20200620201456.14304-1-alexander.kapshuk@gmail.com/. > > Why? > > current->sighand is stable and can't go away. Unless "current" is exiting and > has already passed exit_notify(). So I don't think net/9p needs this helper. From what I can gather from the thread (cf. [1]) that is linked in the commit message the main motivation for all of this is sparse not being happy and not some bug. (Maybe I'm not seeing something though.) The patch itself linked here doesn't seem to buy anything. I agree with Oleg. Afaict, lock_task_sighand() would only be needed here if the task wouldn't be current. So maybe it should just be dropped from the series. [1]: https://lore.kernel.org/lkml/20200620201456.14304-1-alexander.kapshuk@gmail.com/ Christian