• Ard Biesheuvel's avatar
    efi/arm/libstub: Pack FDT after populating it · 72a58a63
    Ard Biesheuvel authored
    Commit:
    
      24d7c494
    
     ("efi/arm-stub: Round up FDT allocation to mapping size")
    
    increased the allocation size for the FDT image created by the stub to a
    fixed value of 2 MB, to simplify the former code that made several
    attempts with increasing values for the size. This is reasonable
    given that the allocation is of type EFI_LOADER_DATA, which is released
    to the kernel unless it is explicitly memblock_reserve()d by the early
    boot code.
    
    However, this allocation size leaked into the 'size' field of the FDT
    header metadata, and so the entire allocation remains occupied by the
    device tree binary, even if most of it is not used to store device tree
    information.
    
    So call fdt_pack() to shrink the FDT data structure to its minimum size
    after populating all the fields, so that the remaining memory is no
    longer wasted.
    Signed-off-by: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
    Cc: <stable@vger.kernel.org> # v4.12+
    Cc: Linus Torvalds <torvalds@linux-foundation.org>
    Cc: Peter Zijlstra <peterz@infradead.org>
    Cc: Thomas Gleixner <tglx@linutronix.de>
    Cc: linux-efi@vger.kernel.org
    Fixes: 24d7c494 ("efi/arm-stub: Round up FDT allocation to mapping size")
    Link: http://lkml.kernel.org/r/20181114175544.12860-4-ard.biesheuvel@linaro.org
    
    Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
    72a58a63
fdt.c 10.6 KB