ftrace: Properly merge notrace hashes

commit 04a80a3 upstream.

The global notrace hash should be jointly decided by the intersection of
each subops's notrace hash, but not the filter hash.

Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/20250408160258.48563-1-andybnac@gmail.com
Fixes: 5fccc75 ("ftrace: Add subops logic to allow one ops to manage many")
Signed-off-by: Andy Chiu <andybnac@gmail.com>
[ fixed removing of freeing of filter_hash ]
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

kernel/trace/ftrace.c

@@ -3542,16 +3542,16 @@ int ftrace_startup_subops(struct ftrace_ops *ops, struct ftrace_ops *subops, int
 	    ftrace_hash_empty(subops->func_hash->notrace_hash)) {
 		notrace_hash = EMPTY_HASH;
 	} else {
-		size_bits = max(ops->func_hash->filter_hash->size_bits,
-				subops->func_hash->filter_hash->size_bits);
+		size_bits = max(ops->func_hash->notrace_hash->size_bits,
+				subops->func_hash->notrace_hash->size_bits);
 		notrace_hash = alloc_ftrace_hash(size_bits);
 		if (!notrace_hash) {
 			free_ftrace_hash(filter_hash);
 			return -ENOMEM;
 		}
 
-		ret = intersect_hash(&notrace_hash, ops->func_hash->filter_hash,
-				     subops->func_hash->filter_hash);
+		ret = intersect_hash(&notrace_hash, ops->func_hash->notrace_hash,
+				     subops->func_hash->notrace_hash);
 		if (ret < 0) {
 			free_ftrace_hash(filter_hash);
 			free_ftrace_hash(notrace_hash);