From: Matt Fleming <matt.fleming@xxxxxxxxx> free_bootmem_late() expects to only be passed RAM regions that the kernel can access, and that have a corresponding 'struct page'. It's possible for regions in the EFI memory map to reside in address ranges for which pfn_to_page() doesn't work, for instance when running on an i386 system with CONFIG_HIGHMEM=n. This is in fact the case for one of Alan's machines where some of the EFI boot services pages live in highmem, and running a kernel without CONFIG_HIGHMEM enabled results in the following oops, BUG: unable to handle kernel paging request at f7f1f080 IP: [<c17fba96>] __free_pages_bootmem+0x5a/0xb8 *pdpt = 0000000001887001 *pde = 0000000001984067 *pte = 000000000 0000000 Oops: 0002 [#1] SMP [...] Call Trace: [<c17feacc>] free_bootmem_late+0x2d/0x3d [<c17f1013>] efi_free_boot_services+0x48/0x5b [<c17ddc12>] start_kernel+0x3ad/0x3cf [<c17dd654>] ? set_init_arg+0x49/0x49 [<c17dd380>] i386_start_kernel+0x12e/0x131 Reported-by: Alan Cox <alan@xxxxxxxxxxxxxxxxxxx> Cc: Matthew Garrett <mjg59@xxxxxxxxxxxxx> Cc: Dave Hansen <dave.hansen@xxxxxxxxx> Cc: Borislav Petkov <bp@xxxxxxx> Signed-off-by: Matt Fleming <matt.fleming@xxxxxxxxx> --- Alan, could you double check that this patch also fixes the oops on your CONFIG_HIGHMEM=n machine? arch/x86/platform/efi/efi.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c index 3781dd39e8bd..893d183ee98f 100644 --- a/arch/x86/platform/efi/efi.c +++ b/arch/x86/platform/efi/efi.c @@ -451,6 +451,9 @@ void __init efi_free_boot_services(void) if (!size) continue; + if (!e820_all_mapped(start, start + size, E820_RAM)) + continue; + free_bootmem_late(start, size); } -- 1.9.0 -- To unsubscribe from this list: send the line "unsubscribe linux-efi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
