tracepoint: Allow livepatch module add trace event

In the case of keeping the system running, the preferred method for
tracing the kernel is dynamic tracing (kprobe), but the drawback of
this method is that events are lost, especially when tracing packages
in the network stack.

Livepatching provides a potential solution, which is to reimplement the
function you want to replace and insert a static tracepoint.
In such a way, custom stable static tracepoints can be expanded without
rebooting the system.

Link: https://lkml.kernel.org/r/[email protected]

Signed-off-by: Jianlin Lv <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>

Author: iecedge

kernel/tracepoint.c

@@ -571,8 +571,8 @@ static void for_each_tracepoint_range(
 bool trace_module_has_bad_taint(struct module *mod)
 {
 	return mod->taints & ~((1 << TAINT_OOT_MODULE) | (1 << TAINT_CRAP) |
-			       (1 << TAINT_UNSIGNED_MODULE) |
-			       (1 << TAINT_TEST));
+				(1 << TAINT_UNSIGNED_MODULE) | (1 << TAINT_TEST) |
+				(1 << TAINT_LIVEPATCH));
 }
 
 static BLOCKING_NOTIFIER_HEAD(tracepoint_notify_list);