[PATCH v5 3/3] use fdt_kaslrseed function to de-duplicate code

[Simon Glass]

On Thu, 30 May 2024 at 16:06, Tim Harvey <tharvey at gateworks.com> wrote:
>
> Use the fdt_kaslrseed function to deduplicate code doing the same thing.
>
> Note that the kalsrseed command (CMD_KASLRSEED) is likely pointless now
> but left in place in case boot scripts exist that rely on this command
> existing and returning success. An informational message is printed to
> alert users of this command that it is likely no longer needed.
>
> Note that the Kernel's EFI STUB only relies on EFI_RNG_PROTOCOL for
> randomization and completely ignores the kaslr-seed for its own
> randomness needs (i.e the randomization of the physical placement of
> the kernel). It gets weeded out from the DTB that gets handed over via
> efi_install_fdt() as it would also mess up the measured boot DTB TPM
> measurements as well.
>
> Signed-off-by: Tim Harvey <tharvey at gateworks.com>
> Cc: Michal Simek <michal.simek at amd.com>
> Cc: Andy Yan <andy.yan at rock-chips.com>
> Cc: Akash Gajjar <gajjar04akash at gmail.com>
> Cc: Ilias Apalodimas <ilias.apalodimas at linaro.org>
> Cc: Simon Glass <sjg at chromium.org>
> Cc: Patrick Delaunay <patrick.delaunay at foss.st.com>
> Cc: Patrice Chotard <patrice.chotard at foss.st.com>
> Cc: Devarsh Thakkar <devarsht at ti.com>
> Cc: Heinrich Schuchardt <xypron.glpk at gmx.de>
> Cc: Hugo Villeneuve <hvilleneuve at dimonoff.com>
> Cc: Marek Vasut <marex at denx.de>
> Cc: Tom Rini <trini at konsulko.com>
> Cc: Chris Morgan <macromorgan at hotmail.com>
> ---
> v5:
>  - fixed typo in commit message s/it's/its/
>  - use cmd_process_error per Michal's suggestion
> v4:
>  - add missing /n to notice in kaslrseed cmd
>  - combine ints in declaration
>  - remove unused vars from board/xilinx/common/board.c ft_board_setup
> v3:
>  - skip if CONFIG_MEASURED_BOOT
>  - fix skip for CONFIG_ARMV8_SEC_FIRMWARE_SUPPORT
>  - pass in rng index and bool to specify overwrite
>  - remove duplicate error strings printed outside of fdt_kaslrseed
>  - added note to commit log about how EFI STUB weeds out kalsr-seed
> v2:
>  - fix typo in commit msg
>  - use stack for seed to avoid unecessary malloc/free
>  - move to a library function and deduplicate code by using it
>    elsewhere
> ---
>  board/xilinx/common/board.c | 40 ------------------------------
>  boot/pxe_utils.c            | 34 +------------------------
>  cmd/kaslrseed.c             | 49 ++++++-------------------------------
>  3 files changed, 8 insertions(+), 115 deletions(-)
>

Reviewed-by: Simon Glass <sjg at chromium.org>