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=-5.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, 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 0F034C43441 for ; Thu, 29 Nov 2018 17:00:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D5A662146D for ; Thu, 29 Nov 2018 17:00:22 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D5A662146D 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 S1730275AbeK3EGX (ORCPT ); Thu, 29 Nov 2018 23:06:23 -0500 Received: from foss.arm.com ([217.140.101.70]:39488 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729519AbeK3EGW (ORCPT ); Thu, 29 Nov 2018 23:06:22 -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 3321BA78; Thu, 29 Nov 2018 09:00:21 -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 661513F59C; Thu, 29 Nov 2018 09:00:19 -0800 (PST) Date: Thu, 29 Nov 2018 17:00:16 +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 v2] mm/memblock: skip kmemleak for kasan_init() Message-ID: <20181129170016.GD22027@arrakis.emea.arm.com> References: <1543442925-17794-1-git-send-email-cai@gmx.us> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1543442925-17794-1-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 05:08:45PM -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 nested loops while KASAN is setting up > full memory mappings, so let early kmemleak allocations skip those > memblock_alloc_internal() calls came from kasan_init() given that those > early KASAN memory mappings should not reference to other memory. > Hence, no kmemleak false positives. > > kasan_init > kasan_map_populate [1] > kasan_pgd_populate [2] > kasan_pud_populate [3] > kasan_pmd_populate [4] > kasan_pte_populate [5] > kasan_alloc_zeroed_page > memblock_alloc_try_nid > memblock_alloc_internal > kmemleak_alloc > > [1] for_each_memblock(memory, reg) > [2] while (pgdp++, addr = next, addr != end) > [3] while (pudp++, addr = next, addr != end && pud_none(READ_ONCE(*pudp))) > [4] while (pmdp++, addr = next, addr != end && pmd_none(READ_ONCE(*pmdp))) > [5] while (ptep++, addr = next, addr != end && pte_none(READ_ONCE(*ptep))) > > Signed-off-by: Qian Cai Acked-by: Catalin Marinas (for both the kmemleak and arm64 changes)