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=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 B6A85C433E2 for ; Fri, 19 Jun 2020 21:17:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9542221556 for ; Fri, 19 Jun 2020 21:17:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592601429; bh=WgPtfgMjjtFmet4xi5SWvdFv7XIRzwyM6syM2L1nqZQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=jIV1W9G/LO8+MOLYqnwckRNjUPkCgMT803uHF4CwN2Oc6FLb+f5QSrjYCFSN6ZHCZ RqULcvw6SMl9AEvTJrmhl0JqLLREPW6fZyzomnjCErMhGypGRRJxkN3w+ZaI/gSckY aOF9SuW+AwmF/x1NP0tuW/EaD68XQMN1gHVVoFeA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726966AbgFSVRF (ORCPT ); Fri, 19 Jun 2020 17:17:05 -0400 Received: from mail-pj1-f68.google.com ([209.85.216.68]:38222 "EHLO mail-pj1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726313AbgFSVRF (ORCPT ); Fri, 19 Jun 2020 17:17:05 -0400 Received: by mail-pj1-f68.google.com with SMTP id d6so4814960pjs.3; Fri, 19 Jun 2020 14:17:03 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=7hNihcV3mvm2VbgzMCb3VuZiHFSALZHgtjxranVJTmE=; b=dFoRRUIOPhGwq71xQ3P5RaSFVt3bmwjhvl5AdFG+meSI/NEIzNPMMe/xEPhAxzdJ2r d50+IrkTF9f1gGmcHySTy01RmU8QPumj3DOkYArg6zbHLPBcw8QAg2cFZul0l3Sfs5Ob NVZGBZgPzPK/dF4mW9jtu+ycQkiChDdC242EIgLwTR5vM4A45huK/cVwNkPc7kfAs1FK m7UJxPpQrCKNg5x8vWei+3cZ5f2S2K93IBHb8+03qBUtQ3soUjocdfODW8pK0tITf5Vj D4165oNfL+4ZtFffGDbWOQc0n+3yUNv/uGpxRsf6guBFMPf8m7zetLKit9qzowIDS4L/ BPFw== X-Gm-Message-State: AOAM53268EVEXHpnR3d9xMFMIGRV9mClDCGDRBXanluYcF3KQrPbMdqW AL+PA3LJMsLIrsDQrzB1QNQ= X-Google-Smtp-Source: ABdhPJzVFn2+ANNt35xVqck48K2jzOLKssbmFAqliq16/KCjcWBHQm/+K7WAIhdQVl6WxrZdgzhwhg== X-Received: by 2002:a17:90a:7a8f:: with SMTP id q15mr4751132pjf.116.1592601423167; Fri, 19 Jun 2020 14:17:03 -0700 (PDT) Received: from 42.do-not-panic.com (42.do-not-panic.com. [157.230.128.187]) by smtp.gmail.com with ESMTPSA id s188sm6551320pfb.118.2020.06.19.14.17.01 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 19 Jun 2020 14:17:01 -0700 (PDT) Received: by 42.do-not-panic.com (Postfix, from userid 1000) id 0E5884063E; Fri, 19 Jun 2020 21:17:00 +0000 (UTC) Date: Fri, 19 Jun 2020 21:17:00 +0000 From: Luis Chamberlain To: Christoph Hellwig , Andrew Morton , Greg Kroah-Hartman Cc: Al Viro , Arnd Bergmann , Brian Gerst , linux-arm-kernel@lists.infradead.org, x86@kernel.org, linux-mips@vger.kernel.org, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, sparclinux@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 6/6] kernel: add a kernel_wait helper Message-ID: <20200619211700.GS11244@42.do-not-panic.com> References: <20200618144627.114057-1-hch@lst.de> <20200618144627.114057-7-hch@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200618144627.114057-7-hch@lst.de> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Thu, Jun 18, 2020 at 04:46:27PM +0200, Christoph Hellwig wrote: > --- a/kernel/exit.c > +++ b/kernel/exit.c > @@ -1626,6 +1626,22 @@ long kernel_wait4(pid_t upid, int __user *stat_addr, int options, > return ret; > } > > +int kernel_wait(pid_t pid, int *stat) > +{ > + struct wait_opts wo = { > + .wo_type = PIDTYPE_PID, > + .wo_pid = find_get_pid(pid), > + .wo_flags = WEXITED, > + }; > + int ret; > + > + ret = do_wait(&wo); > + if (ret > 0 && wo.wo_stat) > + *stat = wo.wo_stat; Since all we care about is WEXITED, that could be simplified to something like this: if (ret > 0 && KWIFEXITED(wo.wo_stat) *stat = KWEXITSTATUS(wo.wo_stat) Otherwise callers have to use W*() wrappers. > + put_pid(wo.wo_pid); > + return ret; > +} Then we don't get *any* in-kernel code dealing with the W*() crap. I just unwrapped this for the umh [0], given that otherwise we'd have to use KW*() callers elsewhere. Doing it upshot one level further would be even better. [0] https://lkml.kernel.org/r/20200610154923.27510-1-mcgrof@kernel.org Luis