From: Steven Rostedt (VMware) <rostedt@goodmis.org>
Date: Tue, 11 Dec 2018 04:58:01 +0000 (-0500)
Subject: tracing: Fix memory leak of instance function hash filters
X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=2840f84f74035e5a535959d5f17269c69fa6edc5;p=openwrt%2Fstaging%2Fblogic.git

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 77734451cb05..e23eb9fc77aa 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -5460,6 +5460,7 @@ void ftrace_destroy_filter_files(struct ftrace_ops *ops)
 	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);
 }