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=-8.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, USER_AGENT_MUTT autolearn=ham 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 37643C43441 for ; Wed, 28 Nov 2018 18:18:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0C49D206B2 for ; Wed, 28 Nov 2018 18:18:22 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0C49D206B2 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729164AbeK2FUv (ORCPT ); Thu, 29 Nov 2018 00:20:51 -0500 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:48134 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726283AbeK2FUv (ORCPT ); Thu, 29 Nov 2018 00:20:51 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 0EC5A80D; Wed, 28 Nov 2018 10:18:20 -0800 (PST) Received: from arrakis.emea.arm.com (arrakis.cambridge.arm.com [10.1.196.113]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 3FE7F3F59C; Wed, 28 Nov 2018 10:18:18 -0800 (PST) Date: Wed, 28 Nov 2018 18:18:15 +0000 From: Catalin Marinas To: Qian Cai Cc: akpm@linux-foundation.org, mhocko@suse.com, rppt@linux.vnet.ibm.com, aryabinin@virtuozzo.com, glider@google.com, dvyukov@google.com, kasan-dev@googlegroups.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] mm/memblock: skip kmemleak for kasan_init() Message-ID: <20181128181815.GN3563@arrakis.emea.arm.com> References: <1543426833-24378-1-git-send-email-cai@gmx.us> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1543426833-24378-1-git-send-email-cai@gmx.us> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Nov 28, 2018 at 12:40:33PM -0500, Qian Cai wrote: > Kmemleak does not play well with KASAN (tested on both HPE Apollo 70 and > Huawei TaiShan 2280 aarch64 servers). > > After calling start_kernel()->setup_arch()->kasan_init(), kmemleak early > log buffer went from something like 280 to 260000 which caused kmemleak > disabled and crash dump memory reservation failed. The multitude of > kmemleak_alloc() calls is from, > > for_each_memblock(memory, reg) x \ > while (pgdp++, addr = next, addr != end) x \ > while (pudp++, addr = next, addr != end && pud_none(READ_ONCE(*pudp))) \ > while (pmdp++, addr = next, addr != end && pmd_none(READ_ONCE(*pmdp))) \ > while (ptep++, addr = next, addr != end && pte_none(READ_ONCE(*ptep))) > > Signed-off-by: Qian Cai Sorry, I didn't get the chance to investigate this further. Hopefully early next week. > diff --git a/mm/memblock.c b/mm/memblock.c > index 9a2d5ae..fd78e39 100644 > --- a/mm/memblock.c > +++ b/mm/memblock.c > @@ -1412,6 +1412,8 @@ static void * __init memblock_alloc_internal( > done: > ptr = phys_to_virt(alloc); > > +/* Skip kmemleak for kasan_init() due to high volume. */ > +#ifndef CONFIG_KASAN > /* > * The min_count is set to 0 so that bootmem allocated blocks > * are never reported as leaks. This is because many of these blocks > @@ -1419,6 +1421,7 @@ static void * __init memblock_alloc_internal( > * looked up by kmemleak. > */ > kmemleak_alloc(ptr, size, 0, 0); > +#endif This may render kmemleak unusable since it is not aware of the memblock allocations and it would trigger lots of false positives. -- Catalin