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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3EDA3CDB482 for ; Tue, 17 Oct 2023 07:14:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234704AbjJQHOD (ORCPT ); Tue, 17 Oct 2023 03:14:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42160 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234403AbjJQHOB (ORCPT ); Tue, 17 Oct 2023 03:14:01 -0400 Received: from bmailout2.hostsharing.net (bmailout2.hostsharing.net [83.223.78.240]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7B6D295; Tue, 17 Oct 2023 00:13:59 -0700 (PDT) Received: from h08.hostsharing.net (h08.hostsharing.net [83.223.95.28]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "*.hostsharing.net", Issuer "RapidSSL Global TLS RSA4096 SHA256 2022 CA1" (verified OK)) by bmailout2.hostsharing.net (Postfix) with ESMTPS id 1B1E72800B758; Tue, 17 Oct 2023 09:13:57 +0200 (CEST) Received: by h08.hostsharing.net (Postfix, from userid 100393) id 0DB1F1D3C4; Tue, 17 Oct 2023 09:13:57 +0200 (CEST) Date: Tue, 17 Oct 2023 09:13:57 +0200 From: Lukas Wunner To: Kai-Heng Feng Cc: bhelgaas@google.com, linux-pm@vger.kernel.org, linux-mmc@vger.kernel.org, Ricky Wu , Kees Cook , Tony Luck , "Guilherme G. Piccoli" , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] PCI: pciehp: Prevent child devices from doing RPM on PCIe Link Down Message-ID: <20231017071357.GB4592@wunner.de> References: <20231016040132.23824-1-kai.heng.feng@canonical.com> <20231016093210.GA22952@wunner.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org [cc -= unrelated mailing lists bpf, kernel-hardening] On Tue, Oct 17, 2023 at 12:35:18PM +0800, Kai-Heng Feng wrote: > On Mon, Oct 16, 2023 at 5:32???PM Lukas Wunner wrote: > > On Mon, Oct 16, 2023 at 12:01:31PM +0800, Kai-Heng Feng wrote: > > > [ 63.898861] pcieport 0000:00:1c.0: pciehp: Slot(8): Link Down > > > [ 63.912118] BUG: unable to handle page fault for address: ffffb24d403e5010 > > [...] > > > [ 63.912198] ? asm_exc_page_fault+0x27/0x30 > > > [ 63.912203] ? ioread32+0x2e/0x70 > > > [ 63.912206] ? rtsx_pci_write_register+0x5b/0x90 [rtsx_pci] > > > [ 63.912217] rtsx_set_l1off_sub+0x1c/0x30 [rtsx_pci] > > > [ 63.912226] rts5261_set_l1off_cfg_sub_d0+0x36/0x40 [rtsx_pci] > > > [ 63.912234] rtsx_pci_runtime_idle+0xc7/0x160 [rtsx_pci] > > > [ 63.912243] ? __pfx_pci_pm_runtime_idle+0x10/0x10 > > > [ 63.912246] pci_pm_runtime_idle+0x34/0x70 > > > [ 63.912248] rpm_idle+0xc4/0x2b0 > > > [ 63.912251] pm_runtime_work+0x93/0xc0 > > > [ 63.912254] process_one_work+0x21a/0x430 > > > [ 63.912258] worker_thread+0x4a/0x3c0 > > > > This looks like pcr->remap_addr is accessed after it has been iounmap'ed > > in rtsx_pci_remove() or before it has been iomap'ed in rtsx_pci_probe(). > > > > Is the card reader itself located below a hotplug port and unplugged here? > > Or is this about the card being removed from the card reader? > > > > Having full dmesg output and lspci -vvv output attached to a bugzilla > > would help to understand what is going on. > > I don't have the hardware so we need Ricky to provide more information here. > > Regardless of the cardreader issue, do you have any concern on the patch > itself? Yes, my concern is that this might be the wrong approach. I would like to understand what is going on, hence my questions above. Thanks, Lukas