• Jiri Kosina's avatar
    livepatch: x86: make kASLR logic more accurate · 5d4351ba
    Jiri Kosina authored
    We give up old_addr hint from the coming patch module in cases when kernel load
    base has been randomized (as in such case, the coming module has no idea about
    the exact randomization offset).
    
    We are currently too pessimistic, and give up immediately as soon as
    CONFIG_RANDOMIZE_BASE is set; this doesn't however directly imply that the
    load base has actually been randomized. There are config options that
    disable kASLR (such as hibernation), user could have disabled kaslr on
    kernel command-line, etc.
    
    The loader propagates the information whether kernel has been randomized
    through bootparams. This allows us to have the condition more accurate.
    
    On top of that, it seems unnecessary to give up old_addr hints even if
    randomization is active. The relocation offset can be computed using
    kaslr_ofsset(), and therefore old_addr can be adjusted accordingly.
    Acked-by: default avatarJosh Poimboeuf <jpoimboe@redhat.com>
    Signed-off-by: default avatarJiri Kosina <jkosina@suse.cz>
    5d4351ba
livepatch.h 1.36 KB