1 files changed, 70 insertions, 31 deletions

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index b4f20fba09fc..4f2ab9352a68 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -64,12 +64,19 @@
 
 #define FL_GLOBAL_CONTROL_MASK (FTRACE_OPS_FL_GLOBAL | FTRACE_OPS_FL_CONTROL)
 
+static struct ftrace_ops ftrace_list_end __read_mostly = {
+        .func           = ftrace_stub,
+};
+
 /* ftrace_enabled is a method to turn ftrace on or off */
 int ftrace_enabled __read_mostly;
 static int last_ftrace_enabled;
 
 /* Quick disabling of function tracer. */
-int function_trace_stop;
+int function_trace_stop __read_mostly;
+
+/* Current function tracing op */
+struct ftrace_ops *function_trace_op __read_mostly = &ftrace_list_end;
 
 /* List for set_ftrace_pid's pids. */
 LIST_HEAD(ftrace_pids);
@@ -86,10 +93,6 @@ static int ftrace_disabled __read_mostly;
 
 static DEFINE_MUTEX(ftrace_lock);
 
-static struct ftrace_ops ftrace_list_end __read_mostly = {
-        .func           = ftrace_stub,
-};
-
 static struct ftrace_ops *ftrace_global_list __read_mostly = &ftrace_list_end;
 static struct ftrace_ops *ftrace_control_list __read_mostly = &ftrace_list_end;
 static struct ftrace_ops *ftrace_ops_list __read_mostly = &ftrace_list_end;
@@ -100,8 +103,14 @@ ftrace_func_t ftrace_pid_function __read_mostly = ftrace_stub;
 static struct ftrace_ops global_ops;
 static struct ftrace_ops control_ops;
 
-static void
-ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip);
+#if ARCH_SUPPORTS_FTRACE_OPS
+static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
+                                 struct ftrace_ops *op);
+#else
+/* See comment below, where ftrace_ops_list_func is defined */
+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
 
 /*
  * Traverse the ftrace_global_list, invoking all entries.  The reason that we
@@ -112,29 +121,29 @@ ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip);
  *
  * Silly Alpha and silly pointer-speculation compiler optimizations!
  */
-static void ftrace_global_list_func(unsigned long ip,
-                                    unsigned long parent_ip)
+static void
+ftrace_global_list_func(unsigned long ip, unsigned long parent_ip,
+                        struct ftrace_ops *op)
 {
-        struct ftrace_ops *op;
-
         if (unlikely(trace_recursion_test(TRACE_GLOBAL_BIT)))
                 return;
 
         trace_recursion_set(TRACE_GLOBAL_BIT);
         op = rcu_dereference_raw(ftrace_global_list); /*see above*/
         while (op != &ftrace_list_end) {
-                op->func(ip, parent_ip);
+                op->func(ip, parent_ip, op);
                 op = rcu_dereference_raw(op->next); /*see above*/
         };
         trace_recursion_clear(TRACE_GLOBAL_BIT);
 }
 
-static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip)
+static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip,
+                            struct ftrace_ops *op)
 {
         if (!test_tsk_trace_trace(current))
                 return;
 
-        ftrace_pid_function(ip, parent_ip);
+        ftrace_pid_function(ip, parent_ip, op);
 }
 
 static void set_ftrace_pid_function(ftrace_func_t func)
@@ -163,12 +172,13 @@ void clear_ftrace_function(void)
  * For those archs that do not test ftrace_trace_stop in their
  * mcount call site, we need to do it from C.
  */
-static void ftrace_test_stop_func(unsigned long ip, unsigned long parent_ip)
+static void ftrace_test_stop_func(unsigned long ip, unsigned long parent_ip,
+                                  struct ftrace_ops *op)
 {
         if (function_trace_stop)
                 return;
 
-        __ftrace_trace_function(ip, parent_ip);
+        __ftrace_trace_function(ip, parent_ip, op);
 }
 #endif
 
@@ -230,15 +240,24 @@ static void update_ftrace_function(void)
 
         /*
          * If we are at the end of the list and this ops is
-         * not dynamic, then have the mcount trampoline call
-         * the function directly
+         * not dynamic and the arch supports passing ops, then have the
+         * mcount trampoline call the function directly.
          */
         if (ftrace_ops_list == &ftrace_list_end ||
             (ftrace_ops_list->next == &ftrace_list_end &&
-             !(ftrace_ops_list->flags & FTRACE_OPS_FL_DYNAMIC)))
+             !(ftrace_ops_list->flags & FTRACE_OPS_FL_DYNAMIC) &&
+             ARCH_SUPPORTS_FTRACE_OPS)) {
+                /* Set the ftrace_ops that the arch callback uses */
+                if (ftrace_ops_list == &global_ops)
+                        function_trace_op = ftrace_global_list;
+                else
+                        function_trace_op = ftrace_ops_list;
                 func = ftrace_ops_list->func;
-        else
+        } else {
+                /* Just use the default ftrace_ops */
+                function_trace_op = &ftrace_list_end;
                 func = ftrace_ops_list_func;
+        }
 
 #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
         ftrace_trace_function = func;
@@ -773,7 +792,8 @@ ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip)
 }
 
 static void
-function_profile_call(unsigned long ip, unsigned long parent_ip)
+function_profile_call(unsigned long ip, unsigned long parent_ip,
+                      struct ftrace_ops *ops)
 {
         struct ftrace_profile_stat *stat;
         struct ftrace_profile *rec;
@@ -803,7 +823,7 @@ function_profile_call(unsigned long ip, unsigned long parent_ip)
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 static int profile_graph_entry(struct ftrace_graph_ent *trace)
 {
-        function_profile_call(trace->func, 0);
+        function_profile_call(trace->func, 0, NULL);
         return 1;
 }
 
@@ -2790,8 +2810,8 @@ static int __init ftrace_mod_cmd_init(void)
 }
 device_initcall(ftrace_mod_cmd_init);
 
-static void
-function_trace_probe_call(unsigned long ip, unsigned long parent_ip)
+static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip,
+                                      struct ftrace_ops *op)
 {
         struct ftrace_func_probe *entry;
         struct hlist_head *hhd;
@@ -3942,10 +3962,9 @@ ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip)
 #endif /* CONFIG_DYNAMIC_FTRACE */
 
 static void
-ftrace_ops_control_func(unsigned long ip, unsigned long parent_ip)
+ftrace_ops_control_func(unsigned long ip, unsigned long parent_ip,
+                        struct ftrace_ops *op)
 {
-        struct ftrace_ops *op;
-
         if (unlikely(trace_recursion_test(TRACE_CONTROL_BIT)))
                 return;
 
@@ -3959,7 +3978,7 @@ ftrace_ops_control_func(unsigned long ip, unsigned long parent_ip)
         while (op != &ftrace_list_end) {
                 if (!ftrace_function_local_disabled(op) &&
                     ftrace_ops_test(op, ip))
-                        op->func(ip, parent_ip);
+                        op->func(ip, parent_ip, op);
 
                 op = rcu_dereference_raw(op->next);
         };
@@ -3971,8 +3990,9 @@ static struct ftrace_ops control_ops = {
         .func = ftrace_ops_control_func,
 };
 
-static void
-ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip)
+static inline void
+__ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
+                       struct ftrace_ops *ignored)
 {
         struct ftrace_ops *op;
 
@@ -3988,13 +4008,32 @@ ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip)
         op = rcu_dereference_raw(ftrace_ops_list);
         while (op != &ftrace_list_end) {
                 if (ftrace_ops_test(op, ip))
-                        op->func(ip, parent_ip);
+                        op->func(ip, parent_ip, op);
                 op = rcu_dereference_raw(op->next);
         };
         preempt_enable_notrace();
         trace_recursion_clear(TRACE_INTERNAL_BIT);
 }
 
+/*
+ * Some archs only support passing ip and parent_ip. Even though
+ * the list function ignores the op parameter, we do not want any
+ * C side effects, where a function is called without the caller
+ * sending a third parameter.
+ */
+#if ARCH_SUPPORTS_FTRACE_OPS
+static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
+                                 struct ftrace_ops *op)
+{
+        __ftrace_ops_list_func(ip, parent_ip, NULL);
+}
+#else
+static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip)
+{
+        __ftrace_ops_list_func(ip, parent_ip, NULL);
+}
+#endif
+
 static void clear_ftrace_swapper(void)
 {
         struct task_struct *p;