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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id DB0F7C433EF for ; Wed, 24 Nov 2021 02:01:23 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 554916B0075; Tue, 23 Nov 2021 21:01:08 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 504D96B0078; Tue, 23 Nov 2021 21:01:08 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 3CC2E6B007B; Tue, 23 Nov 2021 21:01:08 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0006.hostedemail.com [216.40.44.6]) by kanga.kvack.org (Postfix) with ESMTP id 2DD366B0075 for ; Tue, 23 Nov 2021 21:01:08 -0500 (EST) Received: from smtpin28.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id E5857184B3563 for ; Wed, 24 Nov 2021 02:00:57 +0000 (UTC) X-FDA: 78842170554.28.A4C288D Received: from mailgw02.mediatek.com (mailgw02.mediatek.com [216.200.240.185]) by imf31.hostedemail.com (Postfix) with ESMTP id 1715D10529AC for ; Wed, 24 Nov 2021 02:00:49 +0000 (UTC) X-UUID: f90d725ff22f4a46a7527295f8d9f89c-20211123 X-UUID: f90d725ff22f4a46a7527295f8d9f89c-20211123 Received: from mtkcas68.mediatek.inc [(172.29.94.19)] by mailgw02.mediatek.com (envelope-from ) (musrelay.mediatek.com ESMTP with TLSv1.2 ECDHE-RSA-AES256-SHA384 256/256) with ESMTP id 351253479; Tue, 23 Nov 2021 19:00:48 -0700 Received: from MTKMBS07N2.mediatek.inc (172.21.101.141) by MTKMBS62N1.mediatek.inc (172.29.193.41) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Tue, 23 Nov 2021 18:00:46 -0800 Received: from mtkcas11.mediatek.inc (172.21.101.40) by mtkmbs07n2.mediatek.inc (172.21.101.141) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Wed, 24 Nov 2021 10:00:45 +0800 Received: from mtksdccf07 (172.21.84.99) by mtkcas11.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.0.1497.2 via Frontend Transport; Wed, 24 Nov 2021 10:00:45 +0800 Message-ID: <3de431c5711c0f6475f54e89c3de601e1279752a.camel@mediatek.com> Subject: Re: [PATCH] kmemleak: fix kmemleak false positive report with HW tag-based kasan enable From: Kuan-Ying Lee To: Andrew Morton CC: Andrey Konovalov , Catalin Marinas , Matthias Brugger , "Chinwen Chang =?UTF-8?Q?=28=E5=BC=B5=E9=8C=A6=E6=96=87=29?=" , Nicholas Tang =?UTF-8?Q?=28=E9=84=AD=E7=A7=A6=E8=BC=9D=29?= , Yee Lee =?UTF-8?Q?=28=E6=9D=8E=E5=BB=BA=E8=AA=BC=29?= , "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "linux-mediatek@lists.infradead.org" , kasan-dev , , Date: Wed, 24 Nov 2021 10:00:45 +0800 In-Reply-To: <20211119144359.b70d2fde7631bd14cd9652e3@linux-foundation.org> References: <20211118054426.4123-1-Kuan-Ying.Lee@mediatek.com> <754511d9a0368065768cc3ad8037184d62c3fbd1.camel@mediatek.com> <20211119144359.b70d2fde7631bd14cd9652e3@linux-foundation.org> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.28.5-0ubuntu0.18.04.2 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-MTK: N X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: 1715D10529AC X-Stat-Signature: cay8a9fkmeiru8dpwintco8kzpwz1xun Authentication-Results: imf31.hostedemail.com; dkim=none; spf=pass (imf31.hostedemail.com: domain of kuan-ying.lee@mediatek.com designates 216.200.240.185 as permitted sender) smtp.mailfrom=kuan-ying.lee@mediatek.com; dmarc=pass (policy=none) header.from=mediatek.com X-HE-Tag: 1637719249-490363 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 Sat, 2021-11-20 at 06:43 +0800, Andrew Morton wrote: > On Fri, 19 Nov 2021 23:12:55 +0800 Kuan-Ying Lee < > Kuan-Ying.Lee@mediatek.com> wrote: > > > > > > Call sequence: > > > > > ptr = kmalloc(size, GFP_KERNEL); > > > > > page = virt_to_page(ptr); > > > > > kfree(page_address(page)); > > > > > ptr = kmalloc(size, GFP_KERNEL); > > > > > > How is this call sequence valid? page_address returns the address > > > of > > > the start of the page, while kmalloced object could have been > > > located > > > in the middle of it. > > > > Thanks for pointing out. I miss the offset. > > > > It should be listed as below. > > > > ptr = kmalloc(size, GFP_KERNEL); > > page = virt_to_page(ptr); > > offset = offset_in_page(ptr); > > kfree(page_address(page) + offset); > > ptr = kmalloc(size, GFP_KERNEL); > > I updated the changelog to reflect this. Thanks for updating changelog. :)