On Tue, 18 Dec 2018 17:46:36 +0100
Daniel Bristot de Oliveira <bris...@redhat.com> wrote:
> +void text_poke_bp_batch(struct text_to_poke *tp, unsigned int nr_entries)
> +{
> + unsigned int i;
> + unsigned char int3 = 0xcc;
> + int patched_all_but_first = 0;
> +
> + bp_int3_tpv = tp;
> + bp_int3_tpv_nr = nr_entries;
> + bp_patching_in_progress = true;
> + /*
> + * Corresponding read barrier in int3 notifier for making sure the
> + * in_progress and handler are correctly ordered wrt. patching.
> + */
> + smp_wmb();
> +
> + for (i = 0; i < nr_entries; i++)
> + text_poke_bp_set_handler(tp[i].addr, tp[i].handler, int3);
> +
> + on_each_cpu(do_sync_core, NULL, 1);
> +
> + for (i = 0; i < nr_entries; i++) {
> + if (tp->len - sizeof(int3) > 0) {
Should this be:
if (tp[i].len - sizeof(int3) > 0) {
?
-- Steve
> + patch_all_but_first_byte(tp[i].addr, tp[i].opcode,
> + tp[i].len, int3);
> + patched_all_but_first++;
> + }
> + }
> +
> + if (patched_all_but_first) {
> + /*
> + * According to Intel, this core syncing is very likely
> + * not necessary and we'd be safe even without it. But
> + * better safe than sorry (plus there's not only Intel).
> + */
> + on_each_cpu(do_sync_core, NULL, 1);
> + }
> +
> + for (i = 0; i < nr_entries; i++)
> + patch_first_byte(tp[i].addr, tp[i].opcode, int3);
> +
> + on_each_cpu(do_sync_core, NULL, 1);
> + /*
> + * sync_core() implies an smp_mb() and orders this store against
> + * the writing of the new instruction.
> + */
> + bp_int3_tpv_nr = 0;
> + bp_int3_tpv = NULL;
> + bp_patching_in_progress = false;
> +}
