linux

iv/linux

History

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

atom

x86/cpu: Drop pointless static qualifier in punit_dev_state_show()

2018-10-12 12:48:44 +02:00

ce4100

x86/init: Remove i8042_detect() from platform ops

2016-12-19 11:34:15 +01:00

efi

x86/efi: Unmap EFI boot services code/data regions from efi_pgd

2018-11-30 09:10:30 +01:00

geode

x86/platform: Make platform/geode/net5501.c explicitly non-modular