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linux-next/arch/x86/platform/efi
Sai Praneeth Prakhya 08cfb38f3e x86/efi: Unmap EFI boot services code/data regions from efi_pgd
efi_free_boot_services(), as the name suggests, frees EFI boot services
code/data regions but forgets to unmap these regions from efi_pgd. This
means that any code that's running in efi_pgd address space (e.g:
any EFI runtime service) would still be able to access these regions but
the contents of these regions would have long been over written by
someone else. So, it's important to unmap these regions. Hence,
introduce efi_unmap_pages() to unmap these regions from efi_pgd.

After unmapping EFI boot services code/data regions, any illegal access
by buggy firmware to these regions would result in page fault which will
be handled by EFI specific fault handler.

Signed-off-by: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arend van Spriel <arend.vanspriel@broadcom.com>
Cc: Bhupesh Sharma <bhsharma@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Eric Snowberg <eric.snowberg@oracle.com>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Joe Perches <joe@perches.com>
Cc: Jon Hunter <jonathanh@nvidia.com>
Cc: Julien Thierry <julien.thierry@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Nathan Chancellor <natechancellor@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sedat Dilek <sedat.dilek@gmail.com>
Cc: YiFei Zhu <zhuyifei1999@gmail.com>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/20181129171230.18699-6-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-11-30 09:10:30 +01:00
..
early_printk.c x86/earlyprintk/efi: Fix infinite loop on some screen widths 2018-11-30 09:05:13 +01:00
efi_32.c x86/efi: Load fixmap GDT in efi_call_phys_epilog() before setting %cr3 2018-09-12 21:53:34 +02:00
efi_64.c mm: remove include/linux/bootmem.h 2018-10-31 08:54:16 -07:00
efi_stub_32.S License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
efi_stub_64.S License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
efi_thunk_64.S x86/efi: Use efi_switch_mm() rather than manually twiddling with %cr3 2018-03-12 11:05:05 +01:00
efi.c mm: remove include/linux/bootmem.h 2018-10-31 08:54:16 -07:00
Makefile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
quirks.c x86/efi: Unmap EFI boot services code/data regions from efi_pgd 2018-11-30 09:10:30 +01:00