arm64: efi: increase EFI PE/COFF header padding to 64 KB

Commit 76085aff29f5 ("efi/libstub/arm64: align PE/COFF sections to segment
alignment") increased the PE/COFF section alignment to match the minimum
segment alignment of the kernel image, which ensures that the kernel does
not need to be moved around in memory by the EFI stub if it was built as
relocatable.

However, the first PE/COFF section starts at _stext, which is only 4 KB
aligned, and so the section layout is inconsistent. Existing EFI loaders
seem to care little about this, but it is better to clean this up.

So let's pad the header to 64 KB to match the PE/COFF section alignment.

Fixes: 76085aff29f5 ("efi/libstub/arm64: align PE/COFF sections to segment alignment")
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20201027073209.2897-2-ardb@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>

diff --git a/arch/arm64/kernel/efi-header.S b/arch/arm64/kernel/efi-header.S
index df67c0f2a077efef312cb6ae53ff542b91f2e83f..a71844fb923eef9669bd23b087b752c214b8a763 100644 (file)
--- a/arch/arm64/kernel/efi-header.S
+++ b/arch/arm64/kernel/efi-header.S
@@ -147,6 +147,6 @@ efi_debug_entry:
         * correctly at this alignment, we must ensure that .text is
         * placed at a 4k boundary in the Image to begin with.
         */
-       .align 12
+       .balign SEGMENT_ALIGN
 efi_header_end:
        .endm