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authorSteven Rostedt <srostedt@redhat.com>2012-07-20 13:08:05 -0400
committerSteven Rostedt <rostedt@goodmis.org>2012-07-31 10:29:54 -0400
commitea701f11da44b44907af226fe5a5f57d2f26eeb2 (patch)
treebed777e80fb81b28903fe4a64cb90164e499a178 /kernel/trace/ftrace.c
parent47239c4d8d6a24796039cada69d477a2b8cac9d6 (diff)
downloadlinux-ea701f11da44b44907af226fe5a5f57d2f26eeb2.tar.bz2
ftrace: Add selftest to test function trace recursion protection
Add selftests to test the function tracing recursion protection actually does work. It also tests if a ftrace_ops states it will perform its own protection. Although, even if the ftrace_ops states it will protect itself, the ftrace infrastructure may still provide protection if the arch does not support all features or another ftrace_ops is registered. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace/ftrace.c')
-rw-r--r--kernel/trace/ftrace.c21
1 files changed, 21 insertions, 0 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index ad765b4ba426..528d997c7f99 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -111,6 +111,27 @@ static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip);
#define ftrace_ops_list_func ((ftrace_func_t)ftrace_ops_no_ops)
#endif
+/**
+ * ftrace_nr_registered_ops - return number of ops registered
+ *
+ * Returns the number of ftrace_ops registered and tracing functions
+ */
+int ftrace_nr_registered_ops(void)
+{
+ struct ftrace_ops *ops;
+ int cnt = 0;
+
+ mutex_lock(&ftrace_lock);
+
+ for (ops = ftrace_ops_list;
+ ops != &ftrace_list_end; ops = ops->next)
+ cnt++;
+
+ mutex_unlock(&ftrace_lock);
+
+ return cnt;
+}
+
/*
* Traverse the ftrace_global_list, invoking all entries. The reason that we
* can use rcu_dereference_raw() is that elements removed from this list