From: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
Fix to allow user to enable probe events on unloaded modules.
This operations was allowed before commit 60d53e2c3b75 ("tracing/probe:
Split trace_event related data from trace_probe"), because if users
need to probe module init functions, they have to enable those probe
events before loading module.
Link: http://lkml.kernel.org/r/156879693733.31056.9331322616994665167.stgit@devnote2
Cc: stable@xxxxxxxxxxxxxxx
Fixes: 60d53e2c3b75 ("tracing/probe: Split trace_event related data from trace_probe")
Signed-off-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
---
kernel/trace/trace_kprobe.c | 17 +++++------------
1 file changed, 5 insertions(+), 12 deletions(-)
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 7579c53bb053..0ba3239c0270 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -371,31 +371,24 @@ static int enable_trace_kprobe(struct trace_event_call *call,
if (enabled)
return 0;
- enabled = false;
list_for_each_entry(pos, trace_probe_probe_list(tp), list) {
tk = container_of(pos, struct trace_kprobe, tp);
if (trace_kprobe_has_gone(tk))
continue;
ret = __enable_trace_kprobe(tk);
- if (ret) {
- if (enabled) {
- __disable_trace_kprobe(tp);
- enabled = false;
- }
+ if (ret)
break;
- }
enabled = true;
}
- if (!enabled) {
- /* No probe is enabled. Roll back */
+ if (ret) {
+ /* Failed to enable one of them. Roll back all */
+ if (enabled)
+ __disable_trace_kprobe(tp);
if (file)
trace_probe_remove_file(tp, file);
else
trace_probe_clear_flag(tp, TP_FLAG_PROFILE);
- if (!ret)
- /* Since all probes are gone, this is not available */
- ret = -EADDRNOTAVAIL;
}
return ret;
--
2.20.1
