tracing/kprobes: Increment probe hit-count even if it is used by perf
[linux-3.10.git] / kernel / trace / trace_functions.c
index a88a3e0..c4d6d71 100644 (file)
@@ -228,7 +228,7 @@ static int update_count(void **data)
 }
 
 static void
-ftrace_traceon(unsigned long ip, unsigned long parent_ip, void **data)
+ftrace_traceon_count(unsigned long ip, unsigned long parent_ip, void **data)
 {
        if (tracing_is_on())
                return;
@@ -238,7 +238,7 @@ ftrace_traceon(unsigned long ip, unsigned long parent_ip, void **data)
 }
 
 static void
-ftrace_traceoff(unsigned long ip, unsigned long parent_ip, void **data)
+ftrace_traceoff_count(unsigned long ip, unsigned long parent_ip, void **data)
 {
        if (!tracing_is_on())
                return;
@@ -247,32 +247,56 @@ ftrace_traceoff(unsigned long ip, unsigned long parent_ip, void **data)
                tracing_off();
 }
 
-static int
-ftrace_trace_onoff_print(struct seq_file *m, unsigned long ip,
-                        struct ftrace_probe_ops *ops, void *data);
+static void
+ftrace_traceon(unsigned long ip, unsigned long parent_ip, void **data)
+{
+       if (tracing_is_on())
+               return;
 
-static struct ftrace_probe_ops traceon_probe_ops = {
-       .func                   = ftrace_traceon,
-       .print                  = ftrace_trace_onoff_print,
-};
+       tracing_on();
+}
 
-static struct ftrace_probe_ops traceoff_probe_ops = {
-       .func                   = ftrace_traceoff,
-       .print                  = ftrace_trace_onoff_print,
-};
+static void
+ftrace_traceoff(unsigned long ip, unsigned long parent_ip, void **data)
+{
+       if (!tracing_is_on())
+               return;
+
+       tracing_off();
+}
+
+/*
+ * Skip 4:
+ *   ftrace_stacktrace()
+ *   function_trace_probe_call()
+ *   ftrace_ops_list_func()
+ *   ftrace_call()
+ */
+#define STACK_SKIP 4
+
+static void
+ftrace_stacktrace(unsigned long ip, unsigned long parent_ip, void **data)
+{
+       trace_dump_stack(STACK_SKIP);
+}
+
+static void
+ftrace_stacktrace_count(unsigned long ip, unsigned long parent_ip, void **data)
+{
+       if (!tracing_is_on())
+               return;
+
+       if (update_count(data))
+               trace_dump_stack(STACK_SKIP);
+}
 
 static int
-ftrace_trace_onoff_print(struct seq_file *m, unsigned long ip,
-                        struct ftrace_probe_ops *ops, void *data)
+ftrace_probe_print(const char *name, struct seq_file *m,
+                  unsigned long ip, void *data)
 {
        long count = (long)data;
 
-       seq_printf(m, "%ps:", (void *)ip);
-
-       if (ops == &traceon_probe_ops)
-               seq_printf(m, "traceon");
-       else
-               seq_printf(m, "traceoff");
+       seq_printf(m, "%ps:%s", (void *)ip, name);
 
        if (count == -1)
                seq_printf(m, ":unlimited\n");
@@ -283,10 +307,61 @@ ftrace_trace_onoff_print(struct seq_file *m, unsigned long ip,
 }
 
 static int
-ftrace_trace_onoff_callback(struct ftrace_hash *hash,
-                           char *glob, char *cmd, char *param, int enable)
+ftrace_traceon_print(struct seq_file *m, unsigned long ip,
+                        struct ftrace_probe_ops *ops, void *data)
+{
+       return ftrace_probe_print("traceon", m, ip, data);
+}
+
+static int
+ftrace_traceoff_print(struct seq_file *m, unsigned long ip,
+                        struct ftrace_probe_ops *ops, void *data)
+{
+       return ftrace_probe_print("traceoff", m, ip, data);
+}
+
+static int
+ftrace_stacktrace_print(struct seq_file *m, unsigned long ip,
+                       struct ftrace_probe_ops *ops, void *data)
+{
+       return ftrace_probe_print("stacktrace", m, ip, data);
+}
+
+static struct ftrace_probe_ops traceon_count_probe_ops = {
+       .func                   = ftrace_traceon_count,
+       .print                  = ftrace_traceon_print,
+};
+
+static struct ftrace_probe_ops traceoff_count_probe_ops = {
+       .func                   = ftrace_traceoff_count,
+       .print                  = ftrace_traceoff_print,
+};
+
+static struct ftrace_probe_ops stacktrace_count_probe_ops = {
+       .func                   = ftrace_stacktrace_count,
+       .print                  = ftrace_stacktrace_print,
+};
+
+static struct ftrace_probe_ops traceon_probe_ops = {
+       .func                   = ftrace_traceon,
+       .print                  = ftrace_traceon_print,
+};
+
+static struct ftrace_probe_ops traceoff_probe_ops = {
+       .func                   = ftrace_traceoff,
+       .print                  = ftrace_traceoff_print,
+};
+
+static struct ftrace_probe_ops stacktrace_probe_ops = {
+       .func                   = ftrace_stacktrace,
+       .print                  = ftrace_stacktrace_print,
+};
+
+static int
+ftrace_trace_probe_callback(struct ftrace_probe_ops *ops,
+                           struct ftrace_hash *hash, char *glob,
+                           char *cmd, char *param, int enable)
 {
-       struct ftrace_probe_ops *ops;
        void *count = (void *)-1;
        char *number;
        int ret;
@@ -295,12 +370,6 @@ ftrace_trace_onoff_callback(struct ftrace_hash *hash,
        if (!enable)
                return -EINVAL;
 
-       /* we register both traceon and traceoff to this callback */
-       if (strcmp(cmd, "traceon") == 0)
-               ops = &traceon_probe_ops;
-       else
-               ops = &traceoff_probe_ops;
-
        if (glob[0] == '!') {
                unregister_ftrace_function_probe_func(glob+1, ops);
                return 0;
@@ -328,6 +397,34 @@ ftrace_trace_onoff_callback(struct ftrace_hash *hash,
        return ret < 0 ? ret : 0;
 }
 
+static int
+ftrace_trace_onoff_callback(struct ftrace_hash *hash,
+                           char *glob, char *cmd, char *param, int enable)
+{
+       struct ftrace_probe_ops *ops;
+
+       /* we register both traceon and traceoff to this callback */
+       if (strcmp(cmd, "traceon") == 0)
+               ops = param ? &traceon_count_probe_ops : &traceon_probe_ops;
+       else
+               ops = param ? &traceoff_count_probe_ops : &traceoff_probe_ops;
+
+       return ftrace_trace_probe_callback(ops, hash, glob, cmd,
+                                          param, enable);
+}
+
+static int
+ftrace_stacktrace_callback(struct ftrace_hash *hash,
+                          char *glob, char *cmd, char *param, int enable)
+{
+       struct ftrace_probe_ops *ops;
+
+       ops = param ? &stacktrace_count_probe_ops : &stacktrace_probe_ops;
+
+       return ftrace_trace_probe_callback(ops, hash, glob, cmd,
+                                          param, enable);
+}
+
 static struct ftrace_func_command ftrace_traceon_cmd = {
        .name                   = "traceon",
        .func                   = ftrace_trace_onoff_callback,
@@ -338,6 +435,11 @@ static struct ftrace_func_command ftrace_traceoff_cmd = {
        .func                   = ftrace_trace_onoff_callback,
 };
 
+static struct ftrace_func_command ftrace_stacktrace_cmd = {
+       .name                   = "stacktrace",
+       .func                   = ftrace_stacktrace_callback,
+};
+
 static int __init init_func_cmd_traceon(void)
 {
        int ret;
@@ -349,6 +451,12 @@ static int __init init_func_cmd_traceon(void)
        ret = register_ftrace_command(&ftrace_traceon_cmd);
        if (ret)
                unregister_ftrace_command(&ftrace_traceoff_cmd);
+
+       ret = register_ftrace_command(&ftrace_stacktrace_cmd);
+       if (ret) {
+               unregister_ftrace_command(&ftrace_traceoff_cmd);
+               unregister_ftrace_command(&ftrace_traceon_cmd);
+       }
        return ret;
 }
 #else