[PATCH 06/12] tracing/eprobe: Disallow attaching eprobes to fprobe events

[Masami Hiramatsu (Google)]

From: Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>

Event probes (eprobes) are not allowed to attach to other dynamic probe
events (kprobes, uprobes, and eprobes) to avoid recursive probe chains
and lifecycle dependencies. However, when fprobe events were introduced,
TRACE_EVENT_FL_FPROBE was omitted from the exclusion mask in
find_and_get_event(), allowing eprobes to attach to fprobe and tprobe
events.

Exclude TRACE_EVENT_FL_FPROBE events in find_and_get_event().

Fixes: 334e5519c375 ("tracing/probes: Add fprobe events for tracing function entry and exit.")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>
---
 kernel/trace/trace_eprobe.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/kernel/trace/trace_eprobe.c b/kernel/trace/trace_eprobe.c
index 9defe86f4e8f..f65393fb1c10 100644
--- a/kernel/trace/trace_eprobe.c
+++ b/kernel/trace/trace_eprobe.c
@@ -762,7 +762,8 @@ find_and_get_event(const char *system, const char *event_name)
 		    (TRACE_EVENT_FL_IGNORE_ENABLE |
 		     TRACE_EVENT_FL_KPROBE |
 		     TRACE_EVENT_FL_UPROBE |
-		     TRACE_EVENT_FL_EPROBE))
+		     TRACE_EVENT_FL_EPROBE |
+		     TRACE_EVENT_FL_FPROBE))
 			continue;
 		if (!tp_event->class->system ||
 		    strcmp(system, tp_event->class->system))