2 files changed, 5 insertions, 86 deletions

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index d1d8039578a..3c9b96aee51 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -205,20 +205,9 @@ static struct trace_array	max_tr;
 
 static DEFINE_PER_CPU(struct trace_array_cpu, max_tr_data);
 
-/* tracer_enabled is used to toggle activation of a tracer */
-static int                      tracer_enabled = 1;
-
-/**
- * tracing_is_enabled - return tracer_enabled status
- *
- * This function is used by other tracers to know the status
- * of the tracer_enabled flag.  Tracers may use this function
- * to know if it should enable their features when starting
- * up. See irqsoff tracer for an example (start_irqsoff_tracer).
- */
 int tracing_is_enabled(void)
 {
-        return tracer_enabled;
+        return tracing_is_on();
 }
 
 /*
@@ -1112,8 +1101,7 @@ void trace_find_cmdline(int pid, char comm[])
 
 void tracing_record_cmdline(struct task_struct *tsk)
 {
-        if (atomic_read(&trace_record_cmdline_disabled) || !tracer_enabled ||
-            !tracing_is_on())
+        if (atomic_read(&trace_record_cmdline_disabled) || !tracing_is_on())
                 return;
 
         if (!__this_cpu_read(trace_cmdline_save))
@@ -2967,56 +2955,6 @@ static const struct file_operations tracing_saved_cmdlines_fops = {
 };
 
 static ssize_t
-tracing_ctrl_read(struct file *filp, char __user *ubuf,
-                  size_t cnt, loff_t *ppos)
-{
-        char buf[64];
-        int r;
-
-        r = sprintf(buf, "%u\n", tracer_enabled);
-        return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
-}
-
-static ssize_t
-tracing_ctrl_write(struct file *filp, const char __user *ubuf,
-                   size_t cnt, loff_t *ppos)
-{
-        struct trace_array *tr = filp->private_data;
-        unsigned long val;
-        int ret;
-
-        ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
-        if (ret)
-                return ret;
-
-        val = !!val;
-
-        mutex_lock(&trace_types_lock);
-        if (tracer_enabled ^ val) {
-
-                /* Only need to warn if this is used to change the state */
-                WARN_ONCE(1, "tracing_enabled is deprecated. Use tracing_on");
-
-                if (val) {
-                        tracer_enabled = 1;
-                        if (current_trace->start)
-                                current_trace->start(tr);
-                        tracing_start();
-                } else {
-                        tracer_enabled = 0;
-                        tracing_stop();
-                        if (current_trace->stop)
-                                current_trace->stop(tr);
-                }
-        }
-        mutex_unlock(&trace_types_lock);
-
-        *ppos += cnt;
-
-        return cnt;
-}
-
-static ssize_t
 tracing_set_trace_read(struct file *filp, char __user *ubuf,
                        size_t cnt, loff_t *ppos)
 {
@@ -3469,7 +3407,7 @@ static int tracing_wait_pipe(struct file *filp)
                         return -EINTR;
 
                 /*
-                 * We block until we read something and tracing is disabled.
+                 * We block until we read something and tracing is enabled.
                  * We still block if tracing is disabled, but we have never
                  * read anything. This allows a user to cat this file, and
                  * then enable tracing. But after we have read something,
@@ -3477,7 +3415,7 @@ static int tracing_wait_pipe(struct file *filp)
                  *
                  * iter->pos will be 0 if we haven't read anything.
                  */
-                if (!tracer_enabled && iter->pos)
+                if (tracing_is_enabled() && iter->pos)
                         break;
         }
 
@@ -4076,13 +4014,6 @@ static const struct file_operations tracing_max_lat_fops = {
         .llseek         = generic_file_llseek,
 };
 
-static const struct file_operations tracing_ctrl_fops = {
-        .open           = tracing_open_generic,
-        .read           = tracing_ctrl_read,
-        .write          = tracing_ctrl_write,
-        .llseek         = generic_file_llseek,
-};
-
 static const struct file_operations set_tracer_fops = {
         .open           = tracing_open_generic,
         .read           = tracing_set_trace_read,
@@ -4858,7 +4789,7 @@ static __init int tracer_init_debugfs(void)
         d_tracer = tracing_init_dentry();
 
         trace_create_file("tracing_enabled", 0644, d_tracer,
-                        &global_trace, &tracing_ctrl_fops);
+                          &global_trace, &rb_simple_fops);
 
         trace_create_file("trace_options", 0644, d_tracer,
                         NULL, &tracing_iter_fops);
diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c
index 2c00a691a54..091b815f7b0 100644
--- a/kernel/trace/trace_selftest.c
+++ b/kernel/trace/trace_selftest.c
@@ -320,7 +320,6 @@ int trace_selftest_startup_dynamic_tracing(struct tracer *trace,
                                            int (*func)(void))
 {
         int save_ftrace_enabled = ftrace_enabled;
-        int save_tracer_enabled = tracer_enabled;
         unsigned long count;
         char *func_name;
         int ret;
@@ -331,7 +330,6 @@ int trace_selftest_startup_dynamic_tracing(struct tracer *trace,
 
         /* enable tracing, and record the filter function */
         ftrace_enabled = 1;
-        tracer_enabled = 1;
 
         /* passed in by parameter to fool gcc from optimizing */
         func();
@@ -395,7 +393,6 @@ int trace_selftest_startup_dynamic_tracing(struct tracer *trace,
 
  out:
         ftrace_enabled = save_ftrace_enabled;
-        tracer_enabled = save_tracer_enabled;
 
         /* Enable tracing on all functions again */
         ftrace_set_global_filter(NULL, 0, 1);
@@ -452,7 +449,6 @@ static int
 trace_selftest_function_recursion(void)
 {
         int save_ftrace_enabled = ftrace_enabled;
-        int save_tracer_enabled = tracer_enabled;
         char *func_name;
         int len;
         int ret;
@@ -465,7 +461,6 @@ trace_selftest_function_recursion(void)
 
         /* enable tracing, and record the filter function */
         ftrace_enabled = 1;
-        tracer_enabled = 1;
 
         /* Handle PPC64 '.' name */
         func_name = "*" __stringify(DYN_FTRACE_TEST_NAME);
@@ -534,7 +529,6 @@ trace_selftest_function_recursion(void)
         ret = 0;
 out:
         ftrace_enabled = save_ftrace_enabled;
-        tracer_enabled = save_tracer_enabled;
 
         return ret;
 }
@@ -569,7 +563,6 @@ static int
 trace_selftest_function_regs(void)
 {
         int save_ftrace_enabled = ftrace_enabled;
-        int save_tracer_enabled = tracer_enabled;
         char *func_name;
         int len;
         int ret;
@@ -586,7 +579,6 @@ trace_selftest_function_regs(void)
 
         /* enable tracing, and record the filter function */
         ftrace_enabled = 1;
-        tracer_enabled = 1;
 
         /* Handle PPC64 '.' name */
         func_name = "*" __stringify(DYN_FTRACE_TEST_NAME);
@@ -648,7 +640,6 @@ trace_selftest_function_regs(void)
         ret = 0;
 out:
         ftrace_enabled = save_ftrace_enabled;
-        tracer_enabled = save_tracer_enabled;
 
         return ret;
 }
@@ -662,7 +653,6 @@ int
 trace_selftest_startup_function(struct tracer *trace, struct trace_array *tr)
 {
         int save_ftrace_enabled = ftrace_enabled;
-        int save_tracer_enabled = tracer_enabled;
         unsigned long count;
         int ret;
 
@@ -671,7 +661,6 @@ trace_selftest_startup_function(struct tracer *trace, struct trace_array *tr)
 
         /* start the tracing */
         ftrace_enabled = 1;
-        tracer_enabled = 1;
 
         ret = tracer_init(trace, tr);
         if (ret) {
@@ -708,7 +697,6 @@ trace_selftest_startup_function(struct tracer *trace, struct trace_array *tr)
         ret = trace_selftest_function_regs();
  out:
         ftrace_enabled = save_ftrace_enabled;
-        tracer_enabled = save_tracer_enabled;
 
         /* kill ftrace totally if we failed */
         if (ret)