Re: [PATCH v2] firmware_loader: Align .builtin_fw to 8

From: Doug Anderson
Date: Tue Jan 05 2021 - 12:45:46 EST


On Mon, Dec 7, 2020 at 9:49 PM Fangrui Song <maskray@xxxxxxxxxx> wrote:
> arm64 references the start address of .builtin_fw (__start_builtin_fw)
> with a pair of R_AARCH64_ADR_PREL_PG_HI21/R_AARCH64_LDST64_ABS_LO12_NC
> relocations. The compiler is allowed to emit the
> R_AARCH64_LDST64_ABS_LO12_NC relocation because struct builtin_fw in
> include/linux/firmware.h is 8-byte aligned.
> The R_AARCH64_LDST64_ABS_LO12_NC relocation requires the address to be a
> multiple of 8, which may not be the case if .builtin_fw is empty.
> Unconditionally align .builtin_fw to fix the linker error. 32-bit
> architectures could use ALIGN(4) but that would add unnecessary
> complexity, so just use ALIGN(8).
> Fixes: 5658c76 ("firmware: allow firmware files to be built into kernel image")
> Link:
> Reported-by: kernel test robot <lkp@xxxxxxxxx>
> Signed-off-by: Fangrui Song <maskray@xxxxxxxxxx>
> Acked-by: Arnd Bergmann <arnd@xxxxxxxx>
> ---
> Change in v2:
> * Use output section alignment instead of inappropriate ALIGN_FUNCTION()
> ---
> include/asm-generic/ | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)

Tested-by: Douglas Anderson <dianders@xxxxxxxxxxxx>

For whatever reason this is hitting developers on Chrome OS a whole
lot suddenly. Any chance it could be landed? Which tree should it go