tracing: Raw_init() bailout in trace event register fail case
Allow the return value of raw_init() trace event callback to bail us out
of creating a trace event file, in case we fail to register our
event.
Also, we plan to return -ENOSYS for syscall events that don't match any
syscalls listed in our arch tracing syscall table, we don't want to warn
in that case, we just want this event to be invisible in debugfs and
ignored.
Signed-off-by: Jason Baron <jbaron@redhat.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Jiaying Zhang <jiayingz@google.com>
Cc: Martin Bligh <mbligh@google.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Masami Hiramatsu <mhiramat@redhat.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index e0cbede..f95f847 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -925,15 +925,6 @@
if (strcmp(call->system, TRACE_SYSTEM) != 0)
d_events = event_subsystem_dir(call->system, d_events);
- if (call->raw_init) {
- ret = call->raw_init();
- if (ret < 0) {
- pr_warning("Could not initialize trace point"
- " events/%s\n", call->name);
- return ret;
- }
- }
-
call->dir = debugfs_create_dir(call->name, d_events);
if (!call->dir) {
pr_warning("Could not create debugfs "
@@ -1058,6 +1049,7 @@
struct ftrace_module_file_ops *file_ops = NULL;
struct ftrace_event_call *call, *start, *end;
struct dentry *d_events;
+ int ret;
start = mod->trace_events;
end = mod->trace_events + mod->num_trace_events;
@@ -1073,7 +1065,15 @@
/* The linker may leave blanks */
if (!call->name)
continue;
-
+ if (call->raw_init) {
+ ret = call->raw_init();
+ if (ret < 0) {
+ if (ret != -ENOSYS)
+ pr_warning("Could not initialize trace "
+ "point events/%s\n", call->name);
+ continue;
+ }
+ }
/*
* This module has events, create file ops for this module
* if not already done.
@@ -1225,6 +1225,15 @@
/* The linker may leave blanks */
if (!call->name)
continue;
+ if (call->raw_init) {
+ ret = call->raw_init();
+ if (ret < 0) {
+ if (ret != -ENOSYS)
+ pr_warning("Could not initialize trace "
+ "point events/%s\n", call->name);
+ continue;
+ }
+ }
list_add(&call->list, &ftrace_events);
event_create_dir(call, d_events, &ftrace_event_id_fops,
&ftrace_enable_fops, &ftrace_event_filter_fops,