4 files changed, 43 insertions, 6 deletions

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 6fa7292947e..1dc4b9cc20e 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -778,6 +778,13 @@ and is between 256 and 4096 characters. It is defined in the file
                         by the set_ftrace_notrace file in the debugfs
                         tracing directory.
 
+        ftrace_graph_filter=[function-list]
+                        [FTRACE] Limit the top level callers functions traced
+                        by the function graph tracer at boot up.
+                        function-list is a comma separated list of functions
+                        that can be changed at run time by the
+                        set_graph_function file in the debugfs tracing directory.
+
         gamecon.map[2|3]=
                         [HW,JOY] Multisystem joystick and NES/SNES/PSX pad
                         support via parallel port (up to 5 devices per port)
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 1a7f6abd06b..45c965919cf 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -78,6 +78,10 @@ ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub;
 ftrace_func_t __ftrace_trace_function __read_mostly = ftrace_stub;
 ftrace_func_t ftrace_pid_function __read_mostly = ftrace_stub;
 
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+static int ftrace_set_func(unsigned long *array, int *idx, char *buffer);
+#endif
+
 static void ftrace_list_func(unsigned long ip, unsigned long parent_ip)
 {
         struct ftrace_ops *op = ftrace_list;
@@ -2243,6 +2247,7 @@ void ftrace_set_notrace(unsigned char *buf, int len, int reset)
 #define FTRACE_FILTER_SIZE              COMMAND_LINE_SIZE
 static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata;
 static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata;
+static char ftrace_graph_buf[FTRACE_FILTER_SIZE] __initdata;
 
 static int __init set_ftrace_notrace(char *str)
 {
@@ -2258,6 +2263,31 @@ static int __init set_ftrace_filter(char *str)
 }
 __setup("ftrace_filter=", set_ftrace_filter);
 
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+static int __init set_graph_function(char *str)
+{
+        strncpy(ftrace_graph_buf, str, FTRACE_FILTER_SIZE);
+        return 1;
+}
+__setup("ftrace_graph_filter=", set_graph_function);
+
+static void __init set_ftrace_early_graph(char *buf)
+{
+        int ret;
+        char *func;
+
+        while (buf) {
+                func = strsep(&buf, ",");
+                /* we allow only one expression at a time */
+                ret = ftrace_set_func(ftrace_graph_funcs, &ftrace_graph_count,
+                                      func);
+                if (ret)
+                        printk(KERN_DEBUG "ftrace: function %s not "
+                                          "traceable\n", func);
+        }
+}
+#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
+
 static void __init set_ftrace_early_filter(char *buf, int enable)
 {
         char *func;
@@ -2274,6 +2304,10 @@ static void __init set_ftrace_early_filters(void)
                 set_ftrace_early_filter(ftrace_filter_buf, 1);
         if (ftrace_notrace_buf[0])
                 set_ftrace_early_filter(ftrace_notrace_buf, 0);
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+        if (ftrace_graph_buf[0])
+                set_ftrace_early_graph(ftrace_graph_buf);
+#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
 }
 
 static int
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index c820b0310a1..4311ec3062f 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -129,7 +129,7 @@ static int tracing_set_tracer(const char *buf);
 static char bootup_tracer_buf[MAX_TRACER_SIZE] __initdata;
 static char *default_bootup_tracer;
 
-static int __init set_ftrace(char *str)
+static int __init set_bootup_ftrace(char *str)
 {
         strncpy(bootup_tracer_buf, str, MAX_TRACER_SIZE);
         default_bootup_tracer = bootup_tracer_buf;
@@ -137,7 +137,7 @@ static int __init set_ftrace(char *str)
         ring_buffer_expanded = 1;
         return 1;
 }
-__setup("ftrace=", set_ftrace);
+__setup("ftrace=", set_bootup_ftrace);
 
 static int __init set_ftrace_dump_on_oops(char *str)
 {
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 365fb19d9e1..f22a7ac3238 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -483,10 +483,6 @@ static inline int ftrace_graph_addr(unsigned long addr)
         return 0;
 }
 #else
-static inline int ftrace_trace_addr(unsigned long addr)
-{
-        return 1;
-}
 static inline int ftrace_graph_addr(unsigned long addr)
 {
         return 1;