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=-3.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS autolearn=no 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 3CBCAC55178 for ; Sun, 8 Nov 2020 00:56:50 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id B719F20B1F for ; Sun, 8 Nov 2020 00:56:49 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="xwxjPDl+" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B719F20B1F Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id C6E7A6B0036; Sat, 7 Nov 2020 19:56:48 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id C1E606B005D; Sat, 7 Nov 2020 19:56:48 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B0DD16B0068; Sat, 7 Nov 2020 19:56:48 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0130.hostedemail.com [216.40.44.130]) by kanga.kvack.org (Postfix) with ESMTP id 85FA46B0036 for ; Sat, 7 Nov 2020 19:56:48 -0500 (EST) Received: from smtpin24.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 27362180AD806 for ; Sun, 8 Nov 2020 00:56:48 +0000 (UTC) X-FDA: 77459436096.24.shoes37_4016b3a272df Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin24.hostedemail.com (Postfix) with ESMTP id 089D11A4A0 for ; Sun, 8 Nov 2020 00:56:48 +0000 (UTC) X-HE-Tag: shoes37_4016b3a272df X-Filterd-Recvd-Size: 2364 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf32.hostedemail.com (Postfix) with ESMTP for ; Sun, 8 Nov 2020 00:56:47 +0000 (UTC) Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 2727520885; Sun, 8 Nov 2020 00:56:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604797006; bh=/261giqM3SGf4BphJk8rBUodxqpoAGphORKU+/3G2W0=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=xwxjPDl+XMKb88dppa9KT+Klv8aXbRwQ9UGlyqntIQflE109bvZuC45A7d+VPQSkP HlaRq/4a0y7UT/eq66pLNjY31kTs3c/Oe55Q7eIP0wyTXMGzGwyVV++cJEmvTutyvv hDDjFCRLopKIALYmz5iaDG/uEfbBN4f5SlzK+O/U= Date: Sat, 7 Nov 2020 16:56:45 -0800 From: Andrew Morton To: Stefan Agner Cc: minchan@kernel.org, ngupta@vflare.org, sergey.senozhatsky.work@gmail.com, sjenning@linux.vnet.ibm.com, gregkh@linuxfoundation.org, arnd@arndb.de, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] mm/zsmalloc: include sparsemem.h for MAX_PHYSMEM_BITS Message-Id: <20201107165645.1b139b595b6b64feaca61bcb@linux-foundation.org> In-Reply-To: References: X-Mailer: Sylpheed 3.5.1 (GTK+ 2.24.31; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII 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 Sat, 7 Nov 2020 16:22:06 +0100 Stefan Agner wrote: > Most architectures define MAX_PHYSMEM_BITS in asm/sparsemem.h and don't > include it in asm/pgtable.h. Include asm/sparsemem.h directly to get > the MAX_PHYSMEM_BITS define on all architectures. > > This fixes a crash when accessing zram on 32-bit ARM platform with LPAE and > more than 4GB of memory: > Unable to handle kernel NULL pointer dereference at virtual address 00000000 Mysterious. Presumably without this include, some compilation unit is picking up the wrong value of MAX_PHYSMEM_BITS? But I couldn't actually see where/how this occurs. Can you please explain further?