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=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,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 0AB69C47404 for ; Sat, 12 Oct 2019 02:19:10 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 8205D214AF for ; Sat, 12 Oct 2019 02:19:09 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="pTNEFnuw" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8205D214AF Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id ECF9C6B0003; Fri, 11 Oct 2019 22:19:08 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id E80B96B0005; Fri, 11 Oct 2019 22:19:08 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id D6E9B8E0001; Fri, 11 Oct 2019 22:19:08 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0132.hostedemail.com [216.40.44.132]) by kanga.kvack.org (Postfix) with ESMTP id B535B6B0003 for ; Fri, 11 Oct 2019 22:19:08 -0400 (EDT) Received: from smtpin28.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with SMTP id 55E5240DD for ; Sat, 12 Oct 2019 02:19:08 +0000 (UTC) X-FDA: 76033525176.28.shelf33_6cd894194fd2b X-HE-Tag: shelf33_6cd894194fd2b X-Filterd-Recvd-Size: 2657 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf33.hostedemail.com (Postfix) with ESMTP for ; Sat, 12 Oct 2019 02:19:07 +0000 (UTC) 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 AC7032084C; Sat, 12 Oct 2019 02:19:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570846746; bh=vIywkRF0y3e/efdQWoxPos7Bn9uRefc1J4MrajUrp2M=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=pTNEFnuwrBNfpzRaQQhgKjaQTAMa+Q2clQAAueoWlRqLhxg26/qjci1N1oHOFRekR vm5xmpGGf9jLMh6OLy9EyXaBTtcfmBmC3HodBKOq7Bszs8ooKehzG5fNjNzqrvr7Zg xiikhNu+y2LKSOE9cNYZF5x2ahkbpNqNbuzt0SUY= Date: Fri, 11 Oct 2019 19:19:06 -0700 From: Andrew Morton To: Gaowei Pu Cc: Vlastimil Babka , linux-mm@kvack.org Subject: Re: [PATCH] mm/mmap.c: use IS_ERR_VALUE to check return value of get_unmapped_area Message-Id: <20191011191906.9901e400a98f78a9b8652aeb@linux-foundation.org> In-Reply-To: <20191010033117.22294-1-pugaowei@gmail.com> References: <20191010033117.22294-1-pugaowei@gmail.com> 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 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 Thu, 10 Oct 2019 11:31:17 +0800 Gaowei Pu wrote: > get_unmapped_area already cover the offset_in_page() check and returned > with error ptr. So replace offset_in_page() with IS_ERR_VALUE(). > > --- a/mm/mmap.c > +++ b/mm/mmap.c > @@ -2997,7 +2997,7 @@ static int do_brk_flags(unsigned long addr, unsigned long len, unsigned long fla > flags |= VM_DATA_DEFAULT_FLAGS | VM_ACCOUNT | mm->def_flags; > > error = get_unmapped_area(NULL, addr, len, 0, MAP_FIXED); > - if (offset_in_page(error)) > + if (IS_ERR_VALUE(error)) > return error; > > error = mlock_future_check(mm, mm->def_flags, len); ./include/linux/err.h:22:49: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast] #define IS_ERR_VALUE(x) unlikely((unsigned long)(void *)(x) >= (unsigned long)-MAX_ERRNO) ^ ./include/linux/compiler.h:78:42: note: in definition of macro unlikely # define unlikely(x) __builtin_expect(!!(x), 0) ^ mm/mmap.c:3006:6: note: in expansion of macro IS_ERR_VALUE if (IS_ERR_VALUE(error))