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=-2.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,PDS_BAD_THREAD_QP_64, 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 B4087C433DB for ; Thu, 25 Mar 2021 16:01:18 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 3442961A0E for ; Thu, 25 Mar 2021 16:01:18 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3442961A0E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=ACULAB.COM Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 9E6206B0036; Thu, 25 Mar 2021 12:01:17 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 96E406B0071; Thu, 25 Mar 2021 12:01:17 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7E8446B0072; Thu, 25 Mar 2021 12:01:17 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0026.hostedemail.com [216.40.44.26]) by kanga.kvack.org (Postfix) with ESMTP id 5F7796B0036 for ; Thu, 25 Mar 2021 12:01:17 -0400 (EDT) Received: from smtpin38.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 12DE318536160 for ; Thu, 25 Mar 2021 16:01:17 +0000 (UTC) X-FDA: 77958860994.38.956E4B2 Received: from eu-smtp-delivery-151.mimecast.com (eu-smtp-delivery-151.mimecast.com [185.58.85.151]) by imf06.hostedemail.com (Postfix) with ESMTP id 9DB75C0007FD for ; Thu, 25 Mar 2021 16:00:09 +0000 (UTC) Received: from AcuMS.aculab.com (156.67.243.126 [156.67.243.126]) (Using TLS) by relay.mimecast.com with ESMTP id uk-mta-54-d-BEr4zCNlCTYsjGhGGrMA-1; Thu, 25 Mar 2021 16:00:04 +0000 X-MC-Unique: d-BEr4zCNlCTYsjGhGGrMA-1 Received: from AcuMS.Aculab.com (fd9f:af1c:a25b:0:994c:f5c2:35d6:9b65) by AcuMS.aculab.com (fd9f:af1c:a25b:0:994c:f5c2:35d6:9b65) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Thu, 25 Mar 2021 15:59:56 +0000 Received: from AcuMS.Aculab.com ([fe80::994c:f5c2:35d6:9b65]) by AcuMS.aculab.com ([fe80::994c:f5c2:35d6:9b65%12]) with mapi id 15.00.1497.012; Thu, 25 Mar 2021 15:59:56 +0000 From: David Laight To: "'Matthew Wilcox (Oracle)'" , "linux-mm@kvack.org" CC: "linux-kernel@vger.kernel.org" , "Andrew Morton" , Christoph Lameter , "Pekka Enberg" , David Rientjes , "Joonsoo Kim" , Vlastimil Babka , "Uladzislau Rezki" , Nicholas Piggin Subject: RE: [PATCH v2 0/4] vmalloc: Improve vmalloc(4MB) performance Thread-Topic: [PATCH v2 0/4] vmalloc: Improve vmalloc(4MB) performance Thread-Index: AQHXIL93smWggbtuakOz/LFGaMnBoqqU3Ndw Date: Thu, 25 Mar 2021 15:59:56 +0000 Message-ID: <38da93959bc948c992fc7fc1efd4d25c@AcuMS.aculab.com> References: <20210324150518.2734402-1-willy@infradead.org> In-Reply-To: <20210324150518.2734402-1-willy@infradead.org> Accept-Language: en-GB, en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.202.205.107] MIME-Version: 1.0 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=C51A453 smtp.mailfrom=david.laight@aculab.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: aculab.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: 9DB75C0007FD X-Stat-Signature: s4mqr8muujhbb11wiuq3r5y1e4ep7hih Received-SPF: none (aculab.com>: No applicable sender policy available) receiver=imf06; identity=mailfrom; envelope-from=""; helo=eu-smtp-delivery-151.mimecast.com; client-ip=185.58.85.151 X-HE-DKIM-Result: none/none X-HE-Tag: 1616688009-407752 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: From: Matthew Wilcox > Sent: 24 March 2021 15:05 >=20 > I may have gone a little too far with the first patch. It turns out we > have a lot of code using the vmalloc caller functionality, and I decided > to convert it all to unsigned long instead of leaving some paths as void = * > and casting later. What is the 'address of the caller' needed for? If it gets printed anywhere it ought to be a pointer type throughout so that it will get hashed and not leak the real address. Even then it is probably better to use a typed pointer (eg to an undefined structure) than 'void *'. That might also pick up more incorrect uses. Of course things like _RET_IP_ would need changing to return the same pointer type. =09David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1= PT, UK Registration No: 1397386 (Wales)