Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wirel...

[linux-drm-fsl-dcu.git] / kernel / trace / ftrace.c

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 22fa556967609465a0dbd98e238ee1d14b52e328..0e9f9eaade2f6a2dd0e729cd2d3bb38b4f6f8ec0 100644 (file)
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -367,9 +367,6 @@ static int remove_ftrace_list_ops(struct ftrace_ops **list,
 
 static int __register_ftrace_function(struct ftrace_ops *ops)
 {
-       if (unlikely(ftrace_disabled))
-               return -ENODEV;
-
        if (FTRACE_WARN_ON(ops == &global_ops))
                return -EINVAL;
 
@@ -428,9 +425,6 @@ static int __unregister_ftrace_function(struct ftrace_ops *ops)
 {
        int ret;
 
-       if (ftrace_disabled)
-               return -ENODEV;
-
        if (WARN_ON(!(ops->flags & FTRACE_OPS_FL_ENABLED)))
                return -EBUSY;
 
@@ -2088,10 +2082,15 @@ static void ftrace_startup_enable(int command)
 static int ftrace_startup(struct ftrace_ops *ops, int command)
 {
        bool hash_enable = true;
+       int ret;
 
        if (unlikely(ftrace_disabled))
                return -ENODEV;
 
+       ret = __register_ftrace_function(ops);
+       if (ret)
+               return ret;
+
        ftrace_start_up++;
        command |= FTRACE_UPDATE_CALLS;
 
@@ -2113,12 +2112,17 @@ static int ftrace_startup(struct ftrace_ops *ops, int command)
        return 0;
 }
 
-static void ftrace_shutdown(struct ftrace_ops *ops, int command)
+static int ftrace_shutdown(struct ftrace_ops *ops, int command)
 {
        bool hash_disable = true;
+       int ret;
 
        if (unlikely(ftrace_disabled))
-               return;
+               return -ENODEV;
+
+       ret = __unregister_ftrace_function(ops);
+       if (ret)
+               return ret;
 
        ftrace_start_up--;
        /*
@@ -2153,9 +2157,10 @@ static void ftrace_shutdown(struct ftrace_ops *ops, int command)
        }
 
        if (!command || !ftrace_enabled)
-               return;
+               return 0;
 
        ftrace_run_update_code(command);
+       return 0;
 }
 
 static void ftrace_startup_sysctl(void)
@@ -3060,16 +3065,13 @@ static void __enable_ftrace_function_probe(void)
        if (i == FTRACE_FUNC_HASHSIZE)
                return;
 
-       ret = __register_ftrace_function(&trace_probe_ops);
-       if (!ret)
-               ret = ftrace_startup(&trace_probe_ops, 0);
+       ret = ftrace_startup(&trace_probe_ops, 0);
 
        ftrace_probe_registered = 1;
 }
 
 static void __disable_ftrace_function_probe(void)
 {
-       int ret;
        int i;
 
        if (!ftrace_probe_registered)
@@ -3082,9 +3084,7 @@ static void __disable_ftrace_function_probe(void)
        }
 
        /* no more funcs left */
-       ret = __unregister_ftrace_function(&trace_probe_ops);
-       if (!ret)
-               ftrace_shutdown(&trace_probe_ops, 0);
+       ftrace_shutdown(&trace_probe_ops, 0);
 
        ftrace_probe_registered = 0;
 }
@@ -4366,12 +4366,15 @@ core_initcall(ftrace_nodyn_init);
 static inline int ftrace_init_dyn_debugfs(struct dentry *d_tracer) { return 0; }
 static inline void ftrace_startup_enable(int command) { }
 /* Keep as macros so we do not need to define the commands */
-# define ftrace_startup(ops, command)                  \
-       ({                                              \
-               (ops)->flags |= FTRACE_OPS_FL_ENABLED;  \
-               0;                                      \
+# define ftrace_startup(ops, command)                                  \
+       ({                                                              \
+               int ___ret = __register_ftrace_function(ops);           \
+               if (!___ret)                                            \
+                       (ops)->flags |= FTRACE_OPS_FL_ENABLED;          \
+               ___ret;                                                 \
        })
-# define ftrace_shutdown(ops, command) do { } while (0)
+# define ftrace_shutdown(ops, command) __unregister_ftrace_function(ops)
+
 # define ftrace_startup_sysctl()       do { } while (0)
 # define ftrace_shutdown_sysctl()      do { } while (0)
 
@@ -4780,9 +4783,7 @@ int register_ftrace_function(struct ftrace_ops *ops)
 
        mutex_lock(&ftrace_lock);
 
-       ret = __register_ftrace_function(ops);
-       if (!ret)
-               ret = ftrace_startup(ops, 0);
+       ret = ftrace_startup(ops, 0);
 
        mutex_unlock(&ftrace_lock);
 
@@ -4801,9 +4802,7 @@ int unregister_ftrace_function(struct ftrace_ops *ops)
        int ret;
 
        mutex_lock(&ftrace_lock);
-       ret = __unregister_ftrace_function(ops);
-       if (!ret)
-               ftrace_shutdown(ops, 0);
+       ret = ftrace_shutdown(ops, 0);
        mutex_unlock(&ftrace_lock);
 
        return ret;
@@ -4997,6 +4996,13 @@ ftrace_suspend_notifier_call(struct notifier_block *bl, unsigned long state,
        return NOTIFY_DONE;
 }
 
+/* Just a place holder for function graph */
+static struct ftrace_ops fgraph_ops __read_mostly = {
+       .func           = ftrace_stub,
+       .flags          = FTRACE_OPS_FL_STUB | FTRACE_OPS_FL_GLOBAL |
+                               FTRACE_OPS_FL_RECURSION_SAFE,
+};
+
 int register_ftrace_graph(trace_func_graph_ret_t retfunc,
                        trace_func_graph_ent_t entryfunc)
 {
@@ -5023,7 +5029,7 @@ int register_ftrace_graph(trace_func_graph_ret_t retfunc,
        ftrace_graph_return = retfunc;
        ftrace_graph_entry = entryfunc;
 
-       ret = ftrace_startup(&global_ops, FTRACE_START_FUNC_RET);
+       ret = ftrace_startup(&fgraph_ops, FTRACE_START_FUNC_RET);
 
 out:
        mutex_unlock(&ftrace_lock);
@@ -5040,7 +5046,7 @@ void unregister_ftrace_graph(void)
        ftrace_graph_active--;
        ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub;
        ftrace_graph_entry = ftrace_graph_entry_stub;
-       ftrace_shutdown(&global_ops, FTRACE_STOP_FUNC_RET);
+       ftrace_shutdown(&fgraph_ops, FTRACE_STOP_FUNC_RET);
        unregister_pm_notifier(&ftrace_suspend_notifier);
        unregister_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL);