tracing: Fix memory leak of instance function hash filters
The following commands will cause a memory leak:
# cd /sys/kernel/tracing
# mkdir instances/foo
# echo schedule > instance/foo/set_ftrace_filter
# rmdir instances/foo
The reason is that the hashes that hold the filters to set_ftrace_filter and
set_ftrace_notrace are not freed if they contain any data on the instance
and the instance is removed.
Found by kmemleak detector.
Cc: stable@vger.kernel.org
Fixes: 591dffdade9f ("ftrace: Allow for function tracing instance to filter functions")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 7773445..e23eb9f 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -5460,6 +5460,7 @@
if (ops->flags & FTRACE_OPS_FL_ENABLED)
ftrace_shutdown(ops, 0);
ops->flags |= FTRACE_OPS_FL_DELETED;
+ ftrace_free_filter(ops);
mutex_unlock(&ftrace_lock);
}
