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=-0.8 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 79563C433E1 for ; Fri, 3 Jul 2020 14:55:01 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 3B9EC206BE for ; Fri, 3 Jul 2020 14:55:01 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="OC/CRBEs" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3B9EC206BE Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id C805B8D006B; Fri, 3 Jul 2020 10:55:00 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id C585F8D0067; Fri, 3 Jul 2020 10:55:00 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B47C58D006B; Fri, 3 Jul 2020 10:55:00 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0101.hostedemail.com [216.40.44.101]) by kanga.kvack.org (Postfix) with ESMTP id 9D0D28D0067 for ; Fri, 3 Jul 2020 10:55:00 -0400 (EDT) Received: from smtpin26.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 5DE44180AD801 for ; Fri, 3 Jul 2020 14:55:00 +0000 (UTC) X-FDA: 76997061960.26.match48_031702426e92 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin26.hostedemail.com (Postfix) with ESMTP id 355021804A301 for ; Fri, 3 Jul 2020 14:55:00 +0000 (UTC) X-HE-Tag: match48_031702426e92 X-Filterd-Recvd-Size: 2108 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf19.hostedemail.com (Postfix) with ESMTP for ; Fri, 3 Jul 2020 14:54:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=CvKKH16oZBhNB/eW42Qi1UVOuy1Z/Oy4YKpmWORlVSo=; b=OC/CRBEsrpuFKEbrcoPlPOG7BW ll9zEEMzc5rte9m9HmvaDfQpBGIavsHMgaAHtrSjIWV7cmXKKPTuZ2AOjXx0YOpNKW3rMlwXtQ8/l XOP5tbE0W+8A/axbVKtN7mQ0ufGvVhBH8YHcfxT08Nab1skrcbycqTmVqZ8jJDK8REcOKpiXxXnRM /7hwmjnaYrCjZxaES/Pv7wL1pnntuKWS+cIAt+Rjr29IFGbLMRDRw/O2cF4y6u7WWc3HZH7bhb/jt L2usbH/cgRWXS7YC2YEVnvSpYHKHkFlfG7IZqT1xkYtSJenXKYjfwPCPnRrgzL8u9S/dR/zFxOGQ7 GEhBtufw==; Received: from willy by casper.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1jrN5a-000827-VW; Fri, 03 Jul 2020 14:54:55 +0000 Date: Fri, 3 Jul 2020 15:54:54 +0100 From: Matthew Wilcox To: trix@redhat.com Cc: akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] mm: initialize return of vm_insert_pages Message-ID: <20200703145454.GH25523@casper.infradead.org> References: <20200703145202.10629-1-trix@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200703145202.10629-1-trix@redhat.com> X-Rspamd-Queue-Id: 355021804A301 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam04 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Fri, Jul 03, 2020 at 07:52:02AM -0700, trix@redhat.com wrote: > From: Tom Rix > > clang static analysis reports a garbage return > > In file included from mm/memory.c:84: > mm/memory.c:1612:2: warning: Undefined or garbage value returned to caller [core.uninitialized.UndefReturn] > return err; > ^~~~~~~~~~ > > The setting of err depends on a loop executing. > So initialize err. I'd argue that returning zero is wrong. If someone's asked to insert zero pages, that's a nonsense thing to do so it should return -EINVAL..