Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756000Ab3FEOPw (ORCPT ); Wed, 5 Jun 2013 10:15:52 -0400 Received: from arkanian.console-pimps.org ([212.110.184.194]:46120 "EHLO arkanian.console-pimps.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755767Ab3FEOPs (ORCPT ); Wed, 5 Jun 2013 10:15:48 -0400 Date: Wed, 5 Jun 2013 15:15:41 +0100 From: Matt Fleming To: Bjorn Helgaas Cc: Matthew Garrett , "linux-pci@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "x86@kernel.org" , Matt Fleming , Seth Forshee , Jesse Barnes , stable@vger.kernel.org Subject: Re: [PATCH] x86/PCI: setup data may be in highmem Message-ID: <20130605141541.GB30420@console-pimps.org> References: <1369215782-32697-1-git-send-email-matt@console-pimps.org> <20130528113617.GR14575@console-pimps.org> <20130528164801.GA2345@srcf.ucam.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4452 Lines: 118 On Tue, 28 May, at 11:28:54AM, Bjorn Helgaas wrote: > OK, hopefully somebody will do the analysis to verify that ioremap() > is appropriate in both cases. It seems likely, but I haven't looked > in detail. Switching from early_ioremap() to ioremap() seems to work fine from the testing I've seen. I've included the new patch below. Would you prefer a proper submission? --- >From 7a82fbe1d0c74533162487fa1e4bc23877a8a502 Mon Sep 17 00:00:00 2001 From: Matt Fleming Date: Wed, 22 May 2013 09:56:23 +0100 Subject: [PATCH] x86/PCI: setup data may be in highmem pcibios_add_device() assumes that the physical addresses stored in setup_data are accessible via the direct kernel mapping, and that calling phys_to_virt() is valid. This isn't guaranteed to be true on x86 where the direct mapping range is much smaller than on x86-64. Calling phys_to_virt() on a highmem address results in the following, BUG: unable to handle kernel paging request at 39a3c198 IP: [] pcibios_add_device+0x2f/0x90 *pde = 00000000 Oops: 0000 [#1] SMP Modules linked in: Pid: 1, comm: swapper/0 Tainted: G W I 3.9.0-rc2+ #280 EIP: 0060:[] EFLAGS: 00010206 CPU: 1 EIP is at pcibios_add_device+0x2f/0x90 EAX: f6258800 EBX: f6258800 ECX: 79a3c190 EDX: 39a3c190 ESI: f62d9814 EDI: f6258864 EBP: f60add38 ESP: f60add2c DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068 CR0: 8005003b CR2: 39a3c198 CR3: 02b91000 CR4: 001007d0 DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000 DR6: ffff0ff0 DR7: 00000400 Process swapper/0 (pid: 1, ti=f60ac000 task=f60b0000 task.ti=f60ac000) Stack: f6258800 f62d9814 f6258864 f60add4c c2370c73 00000000 f62d9800 00000000 f60add6c c274640b 0000ea60 f6258800 0f008086 f62d9800 f62d9800 00000000 f60add84 c2370d08 00000000 00000008 f62d9800 00000000 f60adda4 c2371904 Call Trace: [] pci_device_add+0xe3/0x130 [] pci_scan_single_device+0x8b/0xb0 [] pci_scan_slot+0x48/0x100 [] pci_scan_child_bus+0x24/0xc0 [] pci_acpi_scan_root+0x2c0/0x490 [] acpi_pci_root_add+0x312/0x42f [] ? acpi_device_notify_fixed+0x1d/0x1d [] acpi_bus_device_attach+0x77/0xdd [] acpi_ns_walk_namespace+0xb1/0x163 [] ? acpi_bus_type_and_status+0x82/0x82 [] acpi_walk_namespace+0x7e/0xa8 [] ? acpi_bus_type_and_status+0x82/0x82 [] acpi_bus_scan+0x9a/0xa6 [] ? acpi_bus_type_and_status+0x82/0x82 [] acpi_scan_init+0x51/0x144 [] ? pci_mmcfg_late_init+0x49/0x4b [] acpi_init+0x224/0x28c [] do_one_initcall+0x34/0x170 [] ? acpi_sleep_proc_init+0x2e/0x2e [] kernel_init_freeable+0x119/0x1b6 [] ? do_early_param+0x74/0x74 [] kernel_init+0x10/0xd0 [] ret_from_kernel_thread+0x1b/0x28 [] ? rest_init+0x60/0x60 The most reliable way to trigger this crash seems to be booting a 32-bit kernel via the EFI boot stub. The solution is to use ioremap() instead of phys_to_virt() to map the setup data into the kernel address space. Tested-by: Jani Nikula Cc: Matthew Garrett Cc: Bjorn Helgaas Cc: Seth Forshee Cc: Jesse Barnes Cc: Signed-off-by: Matt Fleming --- arch/x86/pci/common.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/arch/x86/pci/common.c b/arch/x86/pci/common.c index 305c68b..981c2db 100644 --- a/arch/x86/pci/common.c +++ b/arch/x86/pci/common.c @@ -628,7 +628,9 @@ int pcibios_add_device(struct pci_dev *dev) pa_data = boot_params.hdr.setup_data; while (pa_data) { - data = phys_to_virt(pa_data); + data = ioremap(pa_data, sizeof(*rom)); + if (!data) + return -ENOMEM; if (data->type == SETUP_PCI) { rom = (struct pci_setup_rom *)data; @@ -645,6 +647,7 @@ int pcibios_add_device(struct pci_dev *dev) } } pa_data = data->next; + iounmap(data); } return 0; } -- 1.8.1.4 -- Matt Fleming, Intel Open Source Technology Center -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/