On Fri, 18 Sep 2026, Miroslav Benes wrote:
> Could we also check prev_func/func->nop in the check in
> klp_init_object_loaded() and have a pass if true?
Thanks for the suggestion.
Yes, I've updated the check to skip the pair when both klp_funcs are
nops. Two nops added by klp_add_nops() for replaced aliases are
interchangeable, so an atomic replace patch that inherits nops for
__do_sys_fork and __x64_sys_fork from two previous patches now loads
fine. A non-nop func colliding with a nop (or another non-nop func)
is still rejected, since the nop would land on top of the real
replacement on ops->func_stack and silently disable it.
The incremental change on top of v4 1/5 is:
--- a/kernel/livepatch/core.c
+++ b/kernel/livepatch/core.c
@@ -894,6 +894,8 @@ static int klp_init_object_loaded(struct klp_patch *patch,
if (prev_func == func)
break;
if (prev_func->old_func == func->old_func) {
+ if (prev_func->nop && func->nop)
+ continue;
pr_err("'%s' and '%s' resolve to the same
address, aliased symbols are not supported\n",
prev_func->old_name, func->old_name);
return -EINVAL;
If this direction looks good, I'll resend the series. Petr, should I
just bundle everything into a v5, or do you have changes on your side
that I should wait for?
P.S. Sorry for the second mail. I forgot to quote the message I was
replying to in my first one.
Harry
