[PATCH v3 2/5] ftrace: Do not add duplicate entries in subops manager ops
From: Steven Rostedt
Date: Thu Feb 20 2025 - 15:20:47 EST
From: Steven Rostedt <rostedt@xxxxxxxxxxx>
Check if a function is already in the manager ops of a subops. A manager
ops contains multiple subops, and if two or more subops are tracing the
same function, the manager ops only needs a single entry in its hash.
Cc: stable@xxxxxxxxxxxxxxx
Fixes: 4f554e955614f ("ftrace: Add ftrace_set_filter_ips function")
Tested-by: Heiko Carstens <hca@xxxxxxxxxxxxx>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>
Signed-off-by: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx>
---
kernel/trace/ftrace.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index bec54dc27204..6b0c25761ccb 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -5718,6 +5718,9 @@ __ftrace_match_addr(struct ftrace_hash *hash, unsigned long ip, int remove)
return -ENOENT;
free_hash_entry(hash, entry);
return 0;
+ } else if (__ftrace_lookup_ip(hash, ip) != NULL) {
+ /* Already exists */
+ return 0;
}
entry = add_hash_entry(hash, ip);
--
2.47.2