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=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 92B76C18E00 for ; Wed, 19 Feb 2020 19:50:46 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 4F2FC24654 for ; Wed, 19 Feb 2020 19:50:45 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="j0Q2SNNJ" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4F2FC24654 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 175026B0003; Wed, 19 Feb 2020 14:50:45 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 0FF4D6B0006; Wed, 19 Feb 2020 14:50:45 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id F08436B0007; Wed, 19 Feb 2020 14:50:44 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id D23A36B0003 for ; Wed, 19 Feb 2020 14:50:44 -0500 (EST) Received: from smtpin06.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id A205E824999B for ; Wed, 19 Feb 2020 19:50:44 +0000 (UTC) X-FDA: 76507919208.06.bed20_7ad564b95f721 X-HE-Tag: bed20_7ad564b95f721 X-Filterd-Recvd-Size: 5085 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf32.hostedemail.com (Postfix) with ESMTP for ; Wed, 19 Feb 2020 19:50:43 +0000 (UTC) Received: from X1 (nat-ab2241.sltdut.senawave.net [162.218.216.4]) (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 15A98207FD; Wed, 19 Feb 2020 19:50:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582141843; bh=eiT46h6cjs5cGRD8Py4ELAq6/mSDHNGSWtuhwdPFC68=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=j0Q2SNNJu/5La8erWI6ydWvVV+EQ2a5xDQQhRl6IGSx6/S4BBCC7/lnXBc6gAkn15 TlW1RyJOGfEytCYaWwF2apo+9I4u9DMgUsLN6C/j0xC+K4O87bjU9Cu9gX5DhuF3Ix KFA0A53ZRcG/hTnqnfzya0RQF+eDqvR2SRhoFiXc= Date: Wed, 19 Feb 2020 11:50:42 -0800 From: Andrew Morton To: Baoquan He Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, richardw.yang@linux.intel.com, david@redhat.com, osalvador@suse.de, dan.j.williams@intel.com, mhocko@suse.com Subject: Re: [PATCH v2 RESEND] mm/sparsemem: pfn_to_page is not valid yet on SPARSEMEM Message-Id: <20200219115042.e8738272455292d3a6a6e498@linux-foundation.org> In-Reply-To: <20200219030454.4844-1-bhe@redhat.com> References: <20200219030454.4844-1-bhe@redhat.com> X-Mailer: Sylpheed 3.5.1 (GTK+ 2.24.32; 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 Wed, 19 Feb 2020 11:04:54 +0800 Baoquan He wrote: > From: Wei Yang > > When we use SPARSEMEM instead of SPARSEMEM_VMEMMAP, pfn_to_page() > doesn't work before sparse_init_one_section() is called. This leads to a > crash when hotplug memory: > > [ 41.839170] BUG: unable to handle page fault for address: 0000000006400000 > [ 41.840663] #PF: supervisor write access in kernel mode > [ 41.841822] #PF: error_code(0x0002) - not-present page > [ 41.842970] PGD 0 P4D 0 > [ 41.843538] Oops: 0002 [#1] SMP PTI > [ 41.844125] CPU: 3 PID: 221 Comm: kworker/u16:1 Tainted: G W 5.5.0-next-20200205+ #343 > [ 41.845659] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 0.0.0 02/06/2015 > [ 41.846977] Workqueue: kacpi_hotplug acpi_hotplug_work_fn > [ 41.847904] RIP: 0010:__memset+0x24/0x30 > [ 41.848660] Code: cc cc cc cc cc cc 0f 1f 44 00 00 49 89 f9 48 89 d1 83 e2 07 48 c1 e9 03 40 0f b6 f6 48 b8 01 01 01 01 01 01 01 01 48 0f af c6 48 ab 89 d1 f3 aa 4c 89 c8 c3 90 49 89 f9 40 88 f0 48 89 d1 f3 > [ 41.851836] RSP: 0018:ffffb43ac0373c80 EFLAGS: 00010a87 > [ 41.852686] RAX: ffffffffffffffff RBX: ffff8a1518800000 RCX: 0000000000050000 > [ 41.853824] RDX: 0000000000000000 RSI: 00000000000000ff RDI: 0000000006400000 > [ 41.854967] RBP: 0000000000140000 R08: 0000000000100000 R09: 0000000006400000 > [ 41.856107] R10: 0000000000000000 R11: 0000000000000002 R12: 0000000000000000 > [ 41.857255] R13: 0000000000000028 R14: 0000000000000000 R15: ffff8a153ffd9280 > [ 41.858414] FS: 0000000000000000(0000) GS:ffff8a153ab00000(0000) knlGS:0000000000000000 > [ 41.859703] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [ 41.860627] CR2: 0000000006400000 CR3: 0000000136fca000 CR4: 00000000000006e0 > [ 41.861716] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > [ 41.862680] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > [ 41.863628] Call Trace: > [ 41.863983] sparse_add_section+0x1c9/0x26a > [ 41.864570] __add_pages+0xbf/0x150 > [ 41.865057] add_pages+0x12/0x60 > [ 41.865489] add_memory_resource+0xc8/0x210 > [ 41.866017] ? wake_up_q+0xa0/0xa0 > [ 41.866416] __add_memory+0x62/0xb0 > [ 41.866825] acpi_memory_device_add+0x13f/0x300 > [ 41.867410] acpi_bus_attach+0xf6/0x200 > [ 41.867890] acpi_bus_scan+0x43/0x90 > [ 41.868448] acpi_device_hotplug+0x275/0x3d0 > [ 41.868972] acpi_hotplug_work_fn+0x1a/0x30 > [ 41.869473] process_one_work+0x1a7/0x370 > [ 41.869953] worker_thread+0x30/0x380 > [ 41.870396] ? flush_rcu_work+0x30/0x30 > [ 41.870846] kthread+0x112/0x130 > [ 41.871236] ? kthread_create_on_node+0x60/0x60 > [ 41.871770] ret_from_fork+0x35/0x40 > > We should use memmap as it did. > > Fixes: ba72b4c8cf60 ("mm/sparsemem: support sub-section hotplug") > Signed-off-by: Wei Yang > Acked-by: David Hildenbrand > Reviewed-by: Baoquan He > CC: Dan Williams This should have included your signed-off-by, as you were on the patch delivery path. I have made that change to my copy of the patch - is that OK? I also added a cc:stable. Do we agree this is appropriate? I added Dan's "On x86 the impact is limited to x86_32 builds, or x86_64 configurations that override the default setting for SPARSEMEM_VMEMMAP." to the changelog.