x86/PCI: Map PCI setup data with ioremap() so it can be in highmem
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>
Cc: stable@vger.kernel.org # v3.8+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 @@
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 @@
}
}
pa_data = data->next;
+ iounmap(data);
}
return 0;
}