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=-4.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 16EAFC433F7 for ; Tue, 21 Jul 2020 21:18:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E7AB020729 for ; Tue, 21 Jul 2020 21:18:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1595366322; bh=/nYarywAX7UNUN/53DtQdNHz6+8zh3ZomBd6Fnp5oAE=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=FZ38xKkTTTJsndGsO9CZe8ZxRwS4D+p5N+d8Gk5FK1quQ+noWkj0ZqmdRzQEk5miR D3NFyoh8lTpsQ8VXAq4ALbxS1SBsu5ds6xlKXeNEGIvIjrRDed9YoMcv/GfZNg0yu/ 74/p0A2srscR6N6hdfihDa7sgVUdkstkVRnkoGv8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731510AbgGUVSl (ORCPT ); Tue, 21 Jul 2020 17:18:41 -0400 Received: from mail.kernel.org ([198.145.29.99]:36360 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731204AbgGUVSj (ORCPT ); Tue, 21 Jul 2020 17:18:39 -0400 Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id F394220720; Tue, 21 Jul 2020 21:18:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1595366319; bh=/nYarywAX7UNUN/53DtQdNHz6+8zh3ZomBd6Fnp5oAE=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=mFEJTUe5xMfOSl50caGaOu0RXYLcHaSqYBOZTcdVVaD7VEAd9UP0LO25pyQJFrQa+ JD1tz/c15PTmELr/co+JVxtFuKuEZgr2MZON7CuwUdJdg2ln5oKpGhspdciYX1SzeJ /zdayu98AGVgNG89ff3ttjLIFL8dk9xIWKuoZBSw= Date: Tue, 21 Jul 2020 14:18:38 -0700 From: Andrew Morton To: Christoph Hellwig Cc: mcgrof@kernel.org, linux-kernel@vger.kernel.org, "Eric W. Biederman" Subject: Re: [PATCH] kernel: add a kernel_wait helper Message-Id: <20200721141838.12d19fce025c842138140324@linux-foundation.org> In-Reply-To: <20200721130449.5008-1-hch@lst.de> References: <20200721130449.5008-1-hch@lst.de> X-Mailer: Sylpheed 3.5.1 (GTK+ 2.24.31; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 21 Jul 2020 15:04:49 +0200 Christoph Hellwig wrote: > Add a helper that waits for a pid and stores the status in the passed > in kernel pointer. Use it to fix the usage of kernel_wait4 in > call_usermodehelper_exec_sync that only happens to work due to the > implicit set_fs(KERNEL_DS) for kernel threads. I guess it's cleaner, although it's a bit sad to be adding code to address a non-problem. Did you consider a simpler kernel_wait() which just wraps a set_fs(KERNEL_DS) around a call to kernel_wait4()?