• Guilherme G. Piccoli's avatar
    arm64: Unhash early pointer print plus improve comment · 31e833b2
    Guilherme G. Piccoli authored
    When facing a really early issue on DT parsing we have currently
    a message that shows both the physical and virtual address of the FDT.
    The printk pointer modifier for the virtual address shows a hashed
    address there unless the user provides "no_hash_pointers" parameter in
    the command-line. The situation in which this message shows-up is a bit
    more serious though: the boot process is broken, nothing can be done
    (even an oops is too much for this early stage) so we have this message
    as a last resort in order to help debug bootloader issues, for example.
    Hence, we hereby change that to "%px" in order to make debugging easy,
    there's not much information leak risk in such early boot failure.
    
    Also, we tried to improve a bit the commenting on that function, given
    that if kernel fails there, it just hangs forever in a cpu_relax() loop.
    The reason we cannot BUG/panic is that is too early to do so; thanks to
    Mark Brown for pointing that on IRC and thanks Robin Murphy for the good
    pointer hash discussion in the mailing-list.
    
    Cc: Mark Brown <broonie@kernel.org>
    Cc: Robin Murphy <robin.murphy@arm.com>
    Signed-off-by: default avatarGuilherme G. Piccoli <gpiccoli@igalia.com>
    Reviewed-by: default avatarRobin Murphy <robin.murphy@arm.com>
    Acked-by: default avatarUwe Kleine-König <u.kleine-koenig@pengutronix.de>
    Link: https://lore.kernel.org/r/20211221155230.1532850-1-gpiccoli@igalia.comSigned-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
    31e833b2
setup.c 11.5 KB