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=-1.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS 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 46939C43381 for ; Wed, 20 Mar 2019 20:04:36 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 0795521841 for ; Wed, 20 Mar 2019 20:04:35 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lca.pw header.i=@lca.pw header.b="HPpQBz/C" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0795521841 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lca.pw Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 7D2F96B000A; Wed, 20 Mar 2019 16:04:35 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 782186B000C; Wed, 20 Mar 2019 16:04:35 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 64A4B6B000D; Wed, 20 Mar 2019 16:04:35 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from mail-qt1-f197.google.com (mail-qt1-f197.google.com [209.85.160.197]) by kanga.kvack.org (Postfix) with ESMTP id 43EE36B000A for ; Wed, 20 Mar 2019 16:04:35 -0400 (EDT) Received: by mail-qt1-f197.google.com with SMTP id x12so3722294qtk.2 for ; Wed, 20 Mar 2019 13:04:35 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:dkim-signature:message-id:subject:from:to:cc :date:in-reply-to:references:mime-version:content-transfer-encoding; bh=Vo6r5RiuoHQQbBcC9iguZtdqZ6ajLyJa96gCdeOiWbE=; b=mEKsWwP/kPKAeENRh8cPcz4fpAVW2AP9tdE/iuRJvKpn6SwJrCZ948HPL6aZ1a+qBu X67KqDnEaSmOCTBTIOUOsAvR50valxIAikxAiqAg3vJGNnEthnx9igRkxtLkyTISHxwt QwRDZgvMj3uGMsMUShWmgzYnGkYU9AlQjfo0sSwO4ouqwd4i7xOjnyorvYiQ0t+680aq Pg/CUX+Q/Aw7BC2W46ioI4WoDHdMF644yRpfUB9mX8tAqywEuybZh5O8rYyPZeJWgSxb kW4ZEdvIB9u5IiaCnCzmKwV3V/r13wpE44wgAgMDbW/KEa8xUo2UegyduNdHqKOAv6jt duvA== X-Gm-Message-State: APjAAAXv59eZpj4gA+CbQM/rAdaF+sHl/mlHsuwYkYqPo9iRB8M2fkzr FgPCAolpph8a/dUUbnC42MHfqTWvHA3eBzVbPzzKKy1Hb0JziIJg5xBCoj+GrGE8jr2L0cB2JPW yMWmoUQz4oBXOhuABgkKsX248fE3YWvcw0HjP/2fZQu0tu2FclD4j1BiDBw0+fYvjsQ== X-Received: by 2002:ac8:54c:: with SMTP id c12mr8486454qth.327.1553112275046; Wed, 20 Mar 2019 13:04:35 -0700 (PDT) X-Received: by 2002:ac8:54c:: with SMTP id c12mr8486409qth.327.1553112274405; Wed, 20 Mar 2019 13:04:34 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1553112274; cv=none; d=google.com; s=arc-20160816; b=HpdxSbikVsCi4KWQvVikdKBa2NkSmF7RMLUO0AIg66LeGYP+QRe0iP8h0tlIzIlQF8 q2g8x2QLdBTKIdseHUoH007zDgk5cYQlvxZUPR84eTiuSfKPTxXIV4JAGiusUUEAoaSB THvsI3yUJVjRlPdf9oWcqu0hv58WYOhf6bLdSoFYMdSLtfUKUi+TY7OPDvr1WcOsC1b0 8ZUfVuBHdlckTAqa0iVR+Dy5BP+jrrTOlaYFgeuYPyKz+AuKvmH5vvKBe6YQXUASN67E 8Pp8im1qTwDsEZDdy0O1JE4fsywy67XNmEj9Ld2xJAvPxt/ahzbsCQpAqhpqDCjdO/Yr HVmA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=content-transfer-encoding:mime-version:references:in-reply-to:date :cc:to:from:subject:message-id:dkim-signature; bh=Vo6r5RiuoHQQbBcC9iguZtdqZ6ajLyJa96gCdeOiWbE=; b=A+YEK+nIExZYU5z6nwhOYBZas60r6uum7nidJfUeNa3yJzaIxqwehBEtCpcVYnp34q hEO/X4i1QlFaP3mr0YV8qgL4Vvqc6znpwb46TJPl6KVpbJ9mXA7MQopwNTXUEHiyOL2a 170TBWtxx1PfKlUpojTFSLoJUV+N1nxCINwxqIeHSXJQrmXIDtbrvmzilhhPLiWNIMgX lAjLxFPZs2WtLy+DvvER8MXsoU0dnPz89FEW8TFgQqfGKvBZYA9kRXiULhQgJ36eaA3F SuYE7Fap9M1X1PVU9fTf7f85n1pomO4xWEYZ9oLqAaxUyHzWtTEEQdam5Mg1LgMST0eX brtQ== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@lca.pw header.s=google header.b="HPpQBz/C"; spf=pass (google.com: domain of cai@lca.pw designates 209.85.220.65 as permitted sender) smtp.mailfrom=cai@lca.pw Received: from mail-sor-f65.google.com (mail-sor-f65.google.com. [209.85.220.65]) by mx.google.com with SMTPS id w138sor2235485qka.131.2019.03.20.13.04.34 for (Google Transport Security); Wed, 20 Mar 2019 13:04:34 -0700 (PDT) Received-SPF: pass (google.com: domain of cai@lca.pw designates 209.85.220.65 as permitted sender) client-ip=209.85.220.65; Authentication-Results: mx.google.com; dkim=pass header.i=@lca.pw header.s=google header.b="HPpQBz/C"; spf=pass (google.com: domain of cai@lca.pw designates 209.85.220.65 as permitted sender) smtp.mailfrom=cai@lca.pw DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=lca.pw; s=google; h=message-id:subject:from:to:cc:date:in-reply-to:references :mime-version:content-transfer-encoding; bh=Vo6r5RiuoHQQbBcC9iguZtdqZ6ajLyJa96gCdeOiWbE=; b=HPpQBz/CvqsFaa0YHkIdIWC9iwfw02s4wfgNx/cLGOHj1a5FGWAnDDpEotjpjx0NSL F0gyFf/ieAD253cjGeiAI+MkOvyvKxGe61VtSSWQyyRJBaP7ihSFnE/JoVW2e+vyFmJ/ oOS7inR6aNpv0mA8RAyeReJDsdd38nUMURgiM9zWeRT4BPqOg5Djdld7zvw2Y8Eov+n7 /YZmRaOdN3FdNQJFu/QU8RFIhdswP6VC6E+Es8DpHWFEFDgpkO5rN/P+p1FBRmPnU30m WYfL0DDwwyVAavff0M6gTimy98fqUaF3Rinq/8q+m+aNdLDaewlmpV8kawsjV23Vwx7s G2Fg== X-Google-Smtp-Source: APXvYqyNcoCpTrG/QlxBIiS3xOXvYOWD0i6x08P3+8eR8pgFrkDCEqYQr79GX02pD2JjjO+rwwfWzA== X-Received: by 2002:a37:4d52:: with SMTP id a79mr8186639qkb.75.1553112274192; Wed, 20 Mar 2019 13:04:34 -0700 (PDT) Received: from dhcp-41-57.bos.redhat.com (nat-pool-bos-t.redhat.com. [66.187.233.206]) by smtp.gmail.com with ESMTPSA id h24sm2225964qte.50.2019.03.20.13.04.32 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 20 Mar 2019 13:04:33 -0700 (PDT) Message-ID: <1553112272.26196.9.camel@lca.pw> Subject: Re: [PATCH v2] kmemleak: skip scanning holes in the .bss section From: Qian Cai To: Catalin Marinas , Michael Ellerman Cc: akpm@linux-foundation.org, paulus@ozlabs.org, benh@kernel.crashing.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, kvm-ppc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Date: Wed, 20 Mar 2019 16:04:32 -0400 In-Reply-To: <20190320181656.GB38229@arrakis.emea.arm.com> References: <20190313145717.46369-1-cai@lca.pw> <20190319115747.GB59586@arrakis.emea.arm.com> <87lg19y9dp.fsf@concordia.ellerman.id.au> <20190320181656.GB38229@arrakis.emea.arm.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.22.6 (3.22.6-10.el7) Mime-Version: 1.0 Content-Transfer-Encoding: 7bit X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Wed, 2019-03-20 at 18:16 +0000, Catalin Marinas wrote: > I think I have a simpler idea. Kmemleak allows punching holes in > allocated objects, so just turn the data/bss sections into dedicated > kmemleak objects. This happens when kmemleak is initialised, before the > initcalls are invoked. The kvm_free_tmp() would just free the > corresponding part of the bss. > > Patch below, only tested briefly on arm64. Qian, could you give it a try > on powerpc? Thanks. It works great so far!