A single fix for a EFI boot regression on X86 which was caused by the
recent rework of the EFI memory map parsing. On systems with invalid memmap
entries the cleanup function uses an value which cannot be relied on in
this stage. Use the actual EFI memmap entry instead.
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efi/x86: Fix boot regression on systems with invalid memmap entries

In efi_clean_memmap(), we do a pass over the EFI memory map to remove
bogus entries that may be returned on certain systems.

This recent commit:

  1db91035d01aa8bf ("efi: Add tracking for dynamically allocated memmaps")

refactored this code to pass the input to efi_memmap_install() via a
temporary struct on the stack, which is populated using an initializer
which inadvertently defines the value of its size field in terms of its
desc_size field, which value cannot be relied upon yet in the initializer
itself.

Fix this by using efi.memmap.desc_size instead, which is where we get
the value for desc_size from in the first place.

Reported-by: Jörg Otte <jrg.otte@gmail.com>
Tested-by: Jörg Otte <jrg.otte@gmail.com>
Tested-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: linux-efi@vger.kernel.org
Cc: jrg.otte@gmail.com
Cc: torvalds@linux-foundation.org
Cc: mingo@kernel.org
Link: https://lore.kernel.org/r/20200201233304.18322-1-ardb@kernel.org
1 file changed