enable_trace_fprobe() sets the file link or the TP_FLAG_PROFILE flag and
then registers each trace_fprobe in the probe list. If
__register_trace_fprobe() fails partway through, the function returns
immediately without unregistering the trace_fprobes it already registered
or undoing the file link / flag it set, leaving the event half-enabled and
leaking the registered fprobe(s).
enable_trace_kprobe() already handles this with a rollback path. Do the
same for fprobe: on failure, unregister all probes and clear the file link
or profile flag.
Fixes: 334e5519c375 ("tracing/probes: Add fprobe events for tracing function
entry and exit.")
Cc: [email protected]
Signed-off-by: Raushan Patel <[email protected]>
---
kernel/trace/trace_fprobe.c | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)
diff --git a/kernel/trace/trace_fprobe.c b/kernel/trace/trace_fprobe.c
index 9f5f08c0e7c2..3120403a5b60 100644
--- a/kernel/trace/trace_fprobe.c
+++ b/kernel/trace/trace_fprobe.c
@@ -1481,11 +1481,21 @@ static int enable_trace_fprobe(struct trace_event_call
*call,
list_for_each_entry(tf, trace_probe_probe_list(tp), tp.list) {
ret = __register_trace_fprobe(tf);
if (ret < 0)
- return ret;
+ goto err;
}
}
return 0;
+
+err:
+ /* Failed to enable one of them. Roll back all */
+ list_for_each_entry(tf, trace_probe_probe_list(tp), tp.list)
+ __unregister_trace_fprobe(tf);
+ if (file)
+ trace_probe_remove_file(tp, file);
+ else
+ trace_probe_clear_flag(tp, TP_FLAG_PROFILE);
+ return ret;
}
/*
--
2.53.0
