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=-3.8 required=3.0 tests=BAYES_00, 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 F2066C433E1 for ; Thu, 25 Mar 2021 16:00:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AD2FC61A1A for ; Thu, 25 Mar 2021 16:00:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229624AbhCYQAN convert rfc822-to-8bit (ORCPT ); Thu, 25 Mar 2021 12:00:13 -0400 Received: from eu-smtp-delivery-151.mimecast.com ([185.58.85.151]:31746 "EHLO eu-smtp-delivery-151.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229592AbhCYQAI (ORCPT ); Thu, 25 Mar 2021 12:00:08 -0400 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: 8BIT Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Matthew Wilcox > Sent: 24 March 2021 15:05 > > 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. David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)