Instead of checking if the emitted (default) NOP is the ideal NOP, and conditionally rewrite the NOP, just rewrite the NOP.
This shouldn't be a problem because init / module_load uses text_poke_early() which is cheap and this saves us from having to go figure out which NOP to compare against when we go variable size. Signed-off-by: Peter Zijlstra (Intel) <[email protected]> --- arch/x86/kernel/jump_label.c | 19 ++++--------------- 1 file changed, 4 insertions(+), 15 deletions(-) --- a/arch/x86/kernel/jump_label.c +++ b/arch/x86/kernel/jump_label.c @@ -137,21 +137,10 @@ __init_or_module void arch_jump_label_tr enum jump_label_type type) { /* - * This function is called at boot up and when modules are - * first loaded. Check if the default nop, the one that is - * inserted at compile time, is the ideal nop. If it is, then - * we do not need to update the nop, and we can leave it as is. - * If it is not, then we need to update the nop to the ideal nop. + * Rewrite the NOP on init / module-load to ensure we got the ideal + * nop. Don't bother with trying to figure out what size and what nop + * it should be for now, simply do an unconditional rewrite. */ - if (jlstate == JL_STATE_START) { - const unsigned char default_nop[] = { STATIC_KEY_INIT_NOP }; - const unsigned char *ideal_nop = ideal_nops[NOP_ATOMIC5]; - - if (memcmp(ideal_nop, default_nop, 5) != 0) - jlstate = JL_STATE_UPDATE; - else - jlstate = JL_STATE_NO_UPDATE; - } - if (jlstate == JL_STATE_UPDATE) + if (jlstate == JL_STATE_UPDATE || jlstate == JL_STATE_START) jump_label_transform(entry, type, 1); }
