ftrace: Fix regression of :mod:module function enabling
[linux-2.6.git] / kernel / trace / trace_functions.c
index 36bf956..c7b0c6a 100644 (file)
@@ -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>
@@ -53,14 +54,14 @@ function_trace_call_preempt_only(unsigned long ip, unsigned long parent_ip)
        struct trace_array_cpu *data;
        unsigned long flags;
        long disabled;
-       int cpu, resched;
+       int cpu;
        int pc;
 
        if (unlikely(!ftrace_function_enabled))
                return;
 
        pc = preempt_count();
-       resched = ftrace_preempt_disable();
+       preempt_disable_notrace();
        local_save_flags(flags);
        cpu = raw_smp_processor_id();
        data = tr->data[cpu];
@@ -70,7 +71,7 @@ function_trace_call_preempt_only(unsigned long ip, unsigned long parent_ip)
                trace_function(tr, ip, parent_ip, flags, pc);
 
        atomic_dec(&data->disabled);
-       ftrace_preempt_enable(resched);
+       preempt_enable_notrace();
 }
 
 static void
@@ -148,11 +149,13 @@ function_stack_trace_call(unsigned long ip, unsigned long parent_ip)
 static struct ftrace_ops trace_ops __read_mostly =
 {
        .func = function_trace_call,
+       .flags = FTRACE_OPS_FL_GLOBAL,
 };
 
 static struct ftrace_ops trace_stack_ops __read_mostly =
 {
        .func = function_stack_trace_call,
+       .flags = FTRACE_OPS_FL_GLOBAL,
 };
 
 /* Our two options */
@@ -192,9 +195,11 @@ static void tracing_start_function_trace(void)
 static void tracing_stop_function_trace(void)
 {
        ftrace_function_enabled = 0;
-       /* OK if they are not registered */
-       unregister_ftrace_function(&trace_stack_ops);
-       unregister_ftrace_function(&trace_ops);
+
+       if (func_flags.val & TRACE_FUNC_OPT_STACK)
+               unregister_ftrace_function(&trace_stack_ops);
+       else
+               unregister_ftrace_function(&trace_ops);
 }
 
 static int func_set_flag(u32 old_flags, u32 bit, int set)
@@ -224,6 +229,7 @@ static struct tracer function_trace __read_mostly =
        .init           = function_trace_init,
        .reset          = function_trace_reset,
        .start          = function_trace_start,
+       .wait_pipe      = poll_wait_pipe,
        .flags          = &func_flags,
        .set_flag       = func_set_flag,
 #ifdef CONFIG_FTRACE_SELFTEST
@@ -231,9 +237,170 @@ 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_probe_ops *ops, void *data);
+
+static struct ftrace_probe_ops traceon_probe_ops = {
+       .func                   = ftrace_traceon,
+       .print                  = ftrace_trace_onoff_print,
+};
+
+static struct ftrace_probe_ops traceoff_probe_ops = {
+       .func                   = ftrace_traceoff,
+       .print                  = ftrace_trace_onoff_print,
+};
+
+static int
+ftrace_trace_onoff_print(struct seq_file *m, unsigned long ip,
+                        struct ftrace_probe_ops *ops, 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");
+
+       if (count == -1)
+               seq_printf(m, ":unlimited\n");
+       else
+               seq_printf(m, ":count=%ld\n", count);
+
+       return 0;
+}
+
+static int
+ftrace_trace_onoff_unreg(char *glob, char *cmd, char *param)
+{
+       struct ftrace_probe_ops *ops;
+
+       /* we register both traceon and traceoff to this callback */
+       if (strcmp(cmd, "traceon") == 0)
+               ops = &traceon_probe_ops;
+       else
+               ops = &traceoff_probe_ops;
+
+       unregister_ftrace_function_probe_func(glob, ops);
+
+       return 0;
+}
+
+static int
+ftrace_trace_onoff_callback(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;
+
+       /* 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_probe_ops;
+       else
+               ops = &traceoff_probe_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_probe(glob, ops, count);
+
+       return ret < 0 ? ret : 0;
+}
+
+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);
+