Messages in this thread Patch in this message | | | From | Kamal Mostafa <> | Subject | [PATCH 29/84] x86/PCI: Map PCI setup data with ioremap() so it can be in highmem | Date | Mon, 17 Jun 2013 10:30:33 -0700 |
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3.8.13.3 -stable review patch. If anyone has any objections, please let me know.
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From: Matt Fleming <matt.fleming@intel.com>
commit 65694c5aaddfedd9da082e4e150cafc6b3fc8a6a upstream.
f9a37be0f0 ("x86: Use PCI setup data") added support for using PCI ROM images from setup_data. This used phys_to_virt(), which is not valid for highmem addresses, and can cause a crash when booting a 32-bit kernel via the EFI boot stub.
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: [<c262be0f>] pcibios_add_device+0x2f/0x90 ... Call Trace: [<c2370c73>] pci_device_add+0xe3/0x130 [<c274640b>] pci_scan_single_device+0x8b/0xb0 [<c2370d08>] pci_scan_slot+0x48/0x100 [<c2371904>] pci_scan_child_bus+0x24/0xc0 [<c262a7b0>] pci_acpi_scan_root+0x2c0/0x490 [<c23b7203>] acpi_pci_root_add+0x312/0x42f ...
The solution is to use ioremap() instead of phys_to_virt() to map the setup data into the kernel address space.
[bhelgaas: changelog] Tested-by: Jani Nikula <jani.nikula@intel.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Cc: Seth Forshee <seth.forshee@canonical.com> Cc: Jesse Barnes <jbarnes@virtuousgeek.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> --- 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 ccd0ab3..f24ba14 100644 --- a/arch/x86/pci/common.c +++ b/arch/x86/pci/common.c @@ -618,7 +618,9 @@ 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; @@ -635,6 +637,7 @@ int pcibios_add_device(struct pci_dev *dev) } } pa_data = data->next; + iounmap(data); } return 0; } -- 1.8.1.2
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