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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2017-02-02 13:20:23 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-02-02 13:20:23 -0800 |
| commit | c67b42f3a3f03e68bf915f32c8f7be0b726fec1a (patch) | |
| tree | 9abf8c8a276cd5e8119e5c50f53afc220648008e /arch | |
| parent | 027eb72cbcf81561867a764074964e2ce9828398 (diff) | |
| parent | c8f325a59cfc718d13a50fbc746ed9b415c25e92 (diff) | |
| download | linux-c67b42f3a3f03e68bf915f32c8f7be0b726fec1a.tar.bz2 | |
Merge branch 'efi-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull EFI fixes from Ingo Molnar:
"Two EFI boot fixes, one for arm64 and one for x86 systems with certain
firmware versions"
* 'efi-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
efi/fdt: Avoid FDT manipulation after ExitBootServices()
x86/efi: Always map the first physical page into the EFI pagetables
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/platform/efi/efi_64.c | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/arch/x86/platform/efi/efi_64.c b/arch/x86/platform/efi/efi_64.c index 319148bd4b05..2f25a363068c 100644 --- a/arch/x86/platform/efi/efi_64.c +++ b/arch/x86/platform/efi/efi_64.c @@ -269,6 +269,22 @@ int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages) efi_scratch.use_pgd = true; /* + * Certain firmware versions are way too sentimential and still believe + * they are exclusive and unquestionable owners of the first physical page, + * even though they explicitly mark it as EFI_CONVENTIONAL_MEMORY + * (but then write-access it later during SetVirtualAddressMap()). + * + * Create a 1:1 mapping for this page, to avoid triple faults during early + * boot with such firmware. We are free to hand this page to the BIOS, + * as trim_bios_range() will reserve the first page and isolate it away + * from memory allocators anyway. + */ + if (kernel_map_pages_in_pgd(pgd, 0x0, 0x0, 1, _PAGE_RW)) { + pr_err("Failed to create 1:1 mapping for the first page!\n"); + return 1; + } + + /* * When making calls to the firmware everything needs to be 1:1 * mapped and addressable with 32-bit pointers. Map the kernel * text and allocate a new stack because we can't rely on the |