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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 51177C433EF for ; Tue, 19 Oct 2021 11:37:18 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id D401761373 for ; Tue, 19 Oct 2021 11:37:17 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org D401761373 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id 453A96B006C; Tue, 19 Oct 2021 07:37:17 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 402B66B0071; Tue, 19 Oct 2021 07:37:17 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 3196B900002; Tue, 19 Oct 2021 07:37:17 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0169.hostedemail.com [216.40.44.169]) by kanga.kvack.org (Postfix) with ESMTP id 2141E6B006C for ; Tue, 19 Oct 2021 07:37:17 -0400 (EDT) Received: from smtpin39.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id CF0443C7C2 for ; Tue, 19 Oct 2021 11:37:16 +0000 (UTC) X-FDA: 78712986072.39.53B1E0A Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf20.hostedemail.com (Postfix) with ESMTP id 88AB2D0000A2 for ; Tue, 19 Oct 2021 11:37:13 +0000 (UTC) Received: by mail.kernel.org (Postfix) with ESMTPSA id 25ED0610A1; Tue, 19 Oct 2021 11:37:13 +0000 (UTC) Date: Tue, 19 Oct 2021 12:37:10 +0100 From: Catalin Marinas To: Mike Rapoport Cc: Qian Cai , linux-mm@kvack.org, Andrew Morton , Mike Rapoport , Vladimir Zapolskiy , linux-kernel@vger.kernel.org, Linus Torvalds Subject: Re: [PATCH] memblock: exclude NOMAP regions from kmemleak Message-ID: References: <20211013054756.12177-1-rppt@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: 88AB2D0000A2 X-Stat-Signature: tjm4h9zazkafsam3i3chehnoka9r3phz Authentication-Results: imf20.hostedemail.com; dkim=none; dmarc=fail reason="SPF not aligned (relaxed), No valid DKIM" header.from=arm.com (policy=none); spf=pass (imf20.hostedemail.com: domain of cmarinas@kernel.org designates 198.145.29.99 as permitted sender) smtp.mailfrom=cmarinas@kernel.org X-HE-Tag: 1634643433-121165 Content-Transfer-Encoding: quoted-printable 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 Tue, Oct 19, 2021 at 08:45:49AM +0300, Mike Rapoport wrote: > On Mon, Oct 18, 2021 at 11:55:40PM -0400, Qian Cai wrote: > > On 10/13/2021 1:47 AM, Mike Rapoport wrote: > > > From: Mike Rapoport > > >=20 > > > Vladimir Zapolskiy reports: > > >=20 > > > commit a7259df76702 ("memblock: make memblock_find_in_range method = private") > > > invokes a kernel panic while running kmemleak on OF platforms with = nomaped > > > regions: > > >=20 > > > Unable to handle kernel paging request at virtual address fff0000= 21e00000 > > > [...] > > > scan_block+0x64/0x170 > > > scan_gray_list+0xe8/0x17c > > > kmemleak_scan+0x270/0x514 > > > kmemleak_write+0x34c/0x4ac > > >=20 > > > Indeed, NOMAP regions don't have linear map entries so an attempt t= o scan > > > these areas would fault. > > >=20 > > > Prevent such faults by excluding NOMAP regions from kmemleak. > > >=20 > > > Link: https://lore.kernel.org/all/8ade5174-b143-d621-8c8e-dc6a1898c= 6fb@linaro.org > > > Fixes: a7259df76702 ("memblock: make memblock_find_in_range method = private") > > > Signed-off-by: Mike Rapoport > > > Tested-by: Vladimir Zapolskiy > >=20 > > Mike, reverting this commit on the top of today's linux-next fixed th= e early booting hang > > on an arm64 server with kmemleak. Even with "earlycon", it could only= print out those > > lines. > >=20 > > EFI stub: Booting Linux Kernel... > > EFI stub: EFI_RNG_PROTOCOL unavailable > > EFI stub: ERROR: FIRMWARE BUG: kernel image not aligned on 128k bound= ary > > EFI stub: ERROR: FIRMWARE BUG: Image BSS overlaps adjacent EFI memory= region > > EFI stub: Using DTB from configuration table > > EFI stub: Exiting boot services=E2=80=A6 > >=20 > > I could help to confirm if it hangs right in the early boot somewhere= if needed. >=20 > The kernel config and a log of working kernel would help to start with. I don't think there's much in the log other than the EFI stub above. > > start_kernel() > > setup_arch() > > paging_init() > > map_mem() > > memblock_mark_nomap( Is this actual trace? It would be good to know where exactly it got stuck. > So we have kmemleak_free_part_phys() here. I wonder whether the memblock_mark_nomap() here is too early for kmemleak. We don't have the linear map created, though it shouldn't be an issue as the kernel sections are mapped. Also I think delete_object_part() in kmemleak.c would bail out early as there shouldn't be any prior memblock_alloc for this range. --=20 Catalin