Merge branch 'tip/tracing/ftrace' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into tracing/ftrace

1 files changed, 163 insertions, 0 deletions

diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c
index 36bf9568ccd..f520aa419df 100644
--- a/kernel/trace/trace_functions.c
+++ b/kernel/trace/trace_functions.c
@@ -9,6 +9,7 @@
  *  Copyright (C) 2004-2006 Ingo Molnar
  *  Copyright (C) 2004 William Lee Irwin III
  */
+#include <linux/ring_buffer.h>
 #include <linux/debugfs.h>
 #include <linux/uaccess.h>
 #include <linux/ftrace.h>
@@ -231,9 +232,171 @@ static struct tracer function_trace __read_mostly =
 #endif
 };
 
+#ifdef CONFIG_DYNAMIC_FTRACE
+static void
+ftrace_traceon(unsigned long ip, unsigned long parent_ip, void **data)
+{
+	long *count = (long *)data;
+
+	if (tracing_is_on())
+		return;
+
+	if (!*count)
+		return;
+
+	if (*count != -1)
+		(*count)--;
+
+	tracing_on();
+}
+
+static void
+ftrace_traceoff(unsigned long ip, unsigned long parent_ip, void **data)
+{
+	long *count = (long *)data;
+
+	if (!tracing_is_on())
+		return;
+
+	if (!*count)
+		return;
+
+	if (*count != -1)
+		(*count)--;
+
+	tracing_off();
+}
+
+static int
+ftrace_trace_onoff_print(struct seq_file *m, unsigned long ip,
+			 struct ftrace_hook_ops *ops, void *data);
+
+static struct ftrace_hook_ops traceon_hook_ops = {
+	.func			= ftrace_traceon,
+	.print			= ftrace_trace_onoff_print,
+};
+
+static struct ftrace_hook_ops traceoff_hook_ops = {
+	.func			= ftrace_traceoff,
+	.print			= ftrace_trace_onoff_print,
+};
+
+static int
+ftrace_trace_onoff_print(struct seq_file *m, unsigned long ip,
+			 struct ftrace_hook_ops *ops, void *data)
+{
+	char str[KSYM_SYMBOL_LEN];
+	long count = (long)data;
+
+	kallsyms_lookup(ip, NULL, NULL, NULL, str);
+	seq_printf(m, "%s:", str);
+
+	if (ops == &traceon_hook_ops)
+		seq_printf(m, "traceon");
+	else
+		seq_printf(m, "traceoff");
+
+	if (count != -1)
+		seq_printf(m, ":count=%ld", count);
+	seq_putc(m, '\n');
+
+	return 0;
+}
+
+static int
+ftrace_trace_onoff_unreg(char *glob, char *cmd, char *param)
+{
+	struct ftrace_hook_ops *ops;
+
+	/* we register both traceon and traceoff to this callback */
+	if (strcmp(cmd, "traceon") == 0)
+		ops = &traceon_hook_ops;
+	else
+		ops = &traceoff_hook_ops;
+
+	unregister_ftrace_function_hook_func(glob, ops);
+
+	return 0;
+}
+
+static int
+ftrace_trace_onoff_callback(char *glob, char *cmd, char *param, int enable)
+{
+	struct ftrace_hook_ops *ops;
+	void *count = (void *)-1;
+	char *number;
+	int ret;
+
+	/* hash funcs only work with set_ftrace_filter */
+	if (!enable)
+		return -EINVAL;
+
+	if (glob[0] == '!')
+		return ftrace_trace_onoff_unreg(glob+1, cmd, param);
+
+	/* we register both traceon and traceoff to this callback */
+	if (strcmp(cmd, "traceon") == 0)
+		ops = &traceon_hook_ops;
+	else
+		ops = &traceoff_hook_ops;
+
+	if (!param)
+		goto out_reg;
+
+	number = strsep(&param, ":");
+
+	if (!strlen(number))
+		goto out_reg;
+
+	/*
+	 * We use the callback data field (which is a pointer)
+	 * as our counter.
+	 */
+	ret = strict_strtoul(number, 0, (unsigned long *)&count);
+	if (ret)
+		return ret;
+
+ out_reg:
+	ret = register_ftrace_function_hook(glob, ops, count);
+
+	return ret;
+}
+
+static struct ftrace_func_command ftrace_traceon_cmd = {
+	.name			= "traceon",
+	.func			= ftrace_trace_onoff_callback,
+};
+
+static struct ftrace_func_command ftrace_traceoff_cmd = {
+	.name			= "traceoff",
+	.func			= ftrace_trace_onoff_callback,
+};
+
+static int __init init_func_cmd_traceon(void)
+{
+	int ret;
+
+	ret = register_ftrace_command(&ftrace_traceoff_cmd);
+	if (ret)
+		return ret;
+
+	ret = register_ftrace_command(&ftrace_traceon_cmd);
+	if (ret)
+		unregister_ftrace_command(&ftrace_traceoff_cmd);
+	return ret;
+}
+#else
+static inline int init_func_cmd_traceon(void)
+{
+	return 0;
+}
+#endif /* CONFIG_DYNAMIC_FTRACE */
+
 static __init int init_function_trace(void)
 {
+	init_func_cmd_traceon();
 	return register_tracer(&function_trace);
 }
 
 device_initcall(init_function_trace);
+