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=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,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 E634DC43381 for ; Tue, 19 Mar 2019 11:57:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AAA3E2146E for ; Tue, 19 Mar 2019 11:57:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727415AbfCSL5w (ORCPT ); Tue, 19 Mar 2019 07:57:52 -0400 Received: from foss.arm.com ([217.140.101.70]:50178 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727113AbfCSL5w (ORCPT ); Tue, 19 Mar 2019 07:57:52 -0400 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 C1E1D1596; Tue, 19 Mar 2019 04:57:51 -0700 (PDT) Received: from arrakis.emea.arm.com (arrakis.cambridge.arm.com [10.1.196.78]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 00CD03F614; Tue, 19 Mar 2019 04:57:49 -0700 (PDT) Date: Tue, 19 Mar 2019 11:57:47 +0000 From: Catalin Marinas To: Qian Cai Cc: akpm@linux-foundation.org, paulus@ozlabs.org, benh@kernel.crashing.org, mpe@ellerman.id.au, linux-mm@kvack.org, linux-kernel@vger.kernel.org, kvm-ppc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Subject: Re: [PATCH v2] kmemleak: skip scanning holes in the .bss section Message-ID: <20190319115747.GB59586@arrakis.emea.arm.com> References: <20190313145717.46369-1-cai@lca.pw> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190313145717.46369-1-cai@lca.pw> 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 Hi Qian, On Wed, Mar 13, 2019 at 10:57:17AM -0400, Qian Cai wrote: > @@ -1531,7 +1547,14 @@ static void kmemleak_scan(void) > > /* data/bss scanning */ > scan_large_block(_sdata, _edata); > - scan_large_block(__bss_start, __bss_stop); > + > + if (bss_hole_start) { > + scan_large_block(__bss_start, bss_hole_start); > + scan_large_block(bss_hole_stop, __bss_stop); > + } else { > + scan_large_block(__bss_start, __bss_stop); > + } > + > scan_large_block(__start_ro_after_init, __end_ro_after_init); I'm not a fan of this approach but I couldn't come up with anything better. I was hoping we could check for PageReserved() in scan_block() but on arm64 it ends up not scanning the .bss at all. Until another user appears, I'm ok with this patch. Acked-by: Catalin Marinas