From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qk0-f198.google.com (mail-qk0-f198.google.com [209.85.220.198]) by kanga.kvack.org (Postfix) with ESMTP id 3E5C16B025E for ; Thu, 1 Dec 2016 14:10:43 -0500 (EST) Received: by mail-qk0-f198.google.com with SMTP id m67so187272603qkf.0 for ; Thu, 01 Dec 2016 11:10:43 -0800 (PST) Received: from mail-qt0-f178.google.com (mail-qt0-f178.google.com. [209.85.216.178]) by mx.google.com with ESMTPS id d13si867561qte.229.2016.12.01.11.10.42 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 01 Dec 2016 11:10:42 -0800 (PST) Received: by mail-qt0-f178.google.com with SMTP id n6so230629450qtd.1 for ; Thu, 01 Dec 2016 11:10:42 -0800 (PST) Subject: Re: [PATCHv4 08/10] mm/kasan: Switch to using __pa_symbol and lm_alias References: <1480445729-27130-1-git-send-email-labbott@redhat.com> <1480445729-27130-9-git-send-email-labbott@redhat.com> <2f3ac043-c4cc-5c5a-8ac7-1396b6bb193f@virtuozzo.com> From: Laura Abbott Message-ID: <9dc192b3-a3bd-303a-1b65-00a735a38c74@redhat.com> Date: Thu, 1 Dec 2016 11:10:35 -0800 MIME-Version: 1.0 In-Reply-To: <2f3ac043-c4cc-5c5a-8ac7-1396b6bb193f@virtuozzo.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 8bit Sender: owner-linux-mm@kvack.org List-ID: To: Andrey Ryabinin , Mark Rutland , Ard Biesheuvel , Will Deacon , Catalin Marinas Cc: Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , x86@kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Andrew Morton , Marek Szyprowski , Joonsoo Kim , linux-arm-kernel@lists.infradead.org, Alexander Potapenko , Dmitry Vyukov , kasan-dev@googlegroups.com On 12/01/2016 03:36 AM, Andrey Ryabinin wrote: > On 11/29/2016 09:55 PM, Laura Abbott wrote: >> __pa_symbol is the correct API to find the physical address of symbols. >> Switch to it to allow for debugging APIs to work correctly. > > But __pa() is correct for symbols. I see how __pa_symbol() might be a little > faster than __pa(), but there is nothing wrong in using __pa() on symbols. > >> Other >> functions such as p*d_populate may call __pa internally. Ensure that the >> address passed is in the linear region by calling lm_alias. > > Why it should be linear mapping address? __pa() translates kernel image address just fine. > This lm_alias() only obfuscates source code. Generated code is probably worse too. > > This is part of adding CONFIG_DEBUG_VIRTUAL for arm64. We want to differentiate between __pa and __pa_symbol to enforce stronger virtual checks and have __pa only be for linear map addresses. Thanks, Laura -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org