[PATCH v2 2/5] ftrace: Do not add duplicate entries in subops manager ops

[Steven Rostedt <rostedt@goodmis.org>]

From: Steven Rostedt <rostedt@goodmis.org>

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@vger.kernel.org
Fixes: 4f554e955614f ("ftrace: Add ftrace_set_filter_ips function")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
 kernel/trace/ftrace.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 03b35a05808c..189eb0a12f4b 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -5717,6 +5717,9 @@ __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