Merge tag 'trace-3.15' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:
 "Most of the changes were largely clean ups, and some documentation.
  But there were a few features that were added:

  Uprobes now work with event triggers and multi buffers and have
  support under ftrace and perf.

  The big feature is that the function tracer can now be used within the
  multi buffer instances.  That is, you can now trace some functions in
  one buffer, others in another buffer, all functions in a third buffer
  and so on.  They are basically agnostic from each other.  This only
  works for the function tracer and not for the function graph trace,
  although you can have the function graph tracer running in the top
  level buffer (or any tracer for that matter) and have different
  function tracing going on in the sub buffers"

* tag 'trace-3.15' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (45 commits)
  tracing: Add BUG_ON when stack end location is over written
  tracepoint: Remove unused API functions
  Revert "tracing: Move event storage for array from macro to standalone function"
  ftrace: Constify ftrace_text_reserved
  tracepoints: API doc update to tracepoint_probe_register() return value
  tracepoints: API doc update to data argument
  ftrace: Fix compilation warning about control_ops_free
  ftrace/x86: BUG when ftrace recovery fails
  ftrace: Warn on error when modifying ftrace function
  ftrace: Remove freelist from struct dyn_ftrace
  ftrace: Do not pass data to ftrace_dyn_arch_init
  ftrace: Pass retval through return in ftrace_dyn_arch_init()
  ftrace: Inline the code from ftrace_dyn_table_alloc()
  ftrace: Cleanup of global variables ftrace_new_pgs and ftrace_update_cnt
  tracing: Evaluate len expression only once in __dynamic_array macro
  tracing: Correctly expand len expressions from __dynamic_array macro
  tracing/module: Replace include of tracepoint.h with jump_label.h in module.h
  tracing: Fix event header migrate.h to include tracepoint.h
  tracing: Fix event header writeback.h to include tracepoint.h
  tracing: Warn if a tracepoint is not set via debugfs
  ...

1 files changed, 142 insertions, 45 deletions

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 24c1f238255..9be67c5e5b0 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -73,7 +73,8 @@ static struct tracer_flags dummy_tracer_flags = {
 	.opts = dummy_tracer_opt
 };
 
-static int dummy_set_flag(u32 old_flags, u32 bit, int set)
+static int
+dummy_set_flag(struct trace_array *tr, u32 old_flags, u32 bit, int set)
 {
 	return 0;
 }
@@ -118,7 +119,7 @@ enum ftrace_dump_mode ftrace_dump_on_oops;
 /* When set, tracing will stop when a WARN*() is hit */
 int __disable_trace_on_warning;
 
-static int tracing_set_tracer(const char *buf);
+static int tracing_set_tracer(struct trace_array *tr, const char *buf);
 
 #define MAX_TRACER_SIZE		100
 static char bootup_tracer_buf[MAX_TRACER_SIZE] __initdata;
@@ -180,6 +181,17 @@ static int __init set_trace_boot_options(char *str)
 }
 __setup("trace_options=", set_trace_boot_options);
 
+static char trace_boot_clock_buf[MAX_TRACER_SIZE] __initdata;
+static char *trace_boot_clock __initdata;
+
+static int __init set_trace_boot_clock(char *str)
+{
+	strlcpy(trace_boot_clock_buf, str, MAX_TRACER_SIZE);
+	trace_boot_clock = trace_boot_clock_buf;
+	return 0;
+}
+__setup("trace_clock=", set_trace_boot_clock);
+
 
 unsigned long long ns2usecs(cycle_t nsec)
 {
@@ -1230,7 +1242,7 @@ int register_tracer(struct tracer *type)
 
 	printk(KERN_INFO "Starting tracer '%s'\n", type->name);
 	/* Do we want this tracer to start on bootup? */
-	tracing_set_tracer(type->name);
+	tracing_set_tracer(&global_trace, type->name);
 	default_bootup_tracer = NULL;
 	/* disable other selftests, since this will break it. */
 	tracing_selftest_disabled = true;
@@ -3137,27 +3149,52 @@ static int tracing_open(struct inode *inode, struct file *file)
 	return ret;
 }
 
+/*
+ * Some tracers are not suitable for instance buffers.
+ * A tracer is always available for the global array (toplevel)
+ * or if it explicitly states that it is.
+ */
+static bool
+trace_ok_for_array(struct tracer *t, struct trace_array *tr)
+{
+	return (tr->flags & TRACE_ARRAY_FL_GLOBAL) || t->allow_instances;
+}
+
+/* Find the next tracer that this trace array may use */
+static struct tracer *
+get_tracer_for_array(struct trace_array *tr, struct tracer *t)
+{
+	while (t && !trace_ok_for_array(t, tr))
+		t = t->next;
+
+	return t;
+}
+
 static void *
 t_next(struct seq_file *m, void *v, loff_t *pos)
 {
+	struct trace_array *tr = m->private;
 	struct tracer *t = v;
 
 	(*pos)++;
 
 	if (t)
-		t = t->next;
+		t = get_tracer_for_array(tr, t->next);
 
 	return t;
 }
 
 static void *t_start(struct seq_file *m, loff_t *pos)
 {
+	struct trace_array *tr = m->private;
 	struct tracer *t;
 	loff_t l = 0;
 
 	mutex_lock(&trace_types_lock);
-	for (t = trace_types; t && l < *pos; t = t_next(m, t, &l))
-		;
+
+	t = get_tracer_for_array(tr, trace_types);
+	for (; t && l < *pos; t = t_next(m, t, &l))
+			;
 
 	return t;
 }
@@ -3192,10 +3229,21 @@ static const struct seq_operations show_traces_seq_ops = {
 
 static int show_traces_open(struct inode *inode, struct file *file)
 {
+	struct trace_array *tr = inode->i_private;
+	struct seq_file *m;
+	int ret;
+
 	if (tracing_disabled)
 		return -ENODEV;
 
-	return seq_open(file, &show_traces_seq_ops);
+	ret = seq_open(file, &show_traces_seq_ops);
+	if (ret)
+		return ret;
+
+	m = file->private_data;
+	m->private = tr;
+
+	return 0;
 }
 
 static ssize_t
@@ -3355,13 +3403,14 @@ static int tracing_trace_options_show(struct seq_file *m, void *v)
 	return 0;
 }
 
-static int __set_tracer_option(struct tracer *trace,
+static int __set_tracer_option(struct trace_array *tr,
 			       struct tracer_flags *tracer_flags,
 			       struct tracer_opt *opts, int neg)
 {
+	struct tracer *trace = tr->current_trace;
 	int ret;
 
-	ret = trace->set_flag(tracer_flags->val, opts->bit, !neg);
+	ret = trace->set_flag(tr, tracer_flags->val, opts->bit, !neg);
 	if (ret)
 		return ret;
 
@@ -3373,8 +3422,9 @@ static int __set_tracer_option(struct tracer *trace,
 }
 
 /* Try to assign a tracer specific option */
-static int set_tracer_option(struct tracer *trace, char *cmp, int neg)
+static int set_tracer_option(struct trace_array *tr, char *cmp, int neg)
 {
+	struct tracer *trace = tr->current_trace;
 	struct tracer_flags *tracer_flags = trace->flags;
 	struct tracer_opt *opts = NULL;
 	int i;
@@ -3383,8 +3433,7 @@ static int set_tracer_option(struct tracer *trace, char *cmp, int neg)
 		opts = &tracer_flags->opts[i];
 
 		if (strcmp(cmp, opts->name) == 0)
-			return __set_tracer_option(trace, trace->flags,
-						   opts, neg);
+			return __set_tracer_option(tr, trace->flags, opts, neg);
 	}
 
 	return -EINVAL;
@@ -3407,7 +3456,7 @@ int set_tracer_flag(struct trace_array *tr, unsigned int mask, int enabled)
 
 	/* Give the tracer a chance to approve the change */
 	if (tr->current_trace->flag_changed)
-		if (tr->current_trace->flag_changed(tr->current_trace, mask, !!enabled))
+		if (tr->current_trace->flag_changed(tr, mask, !!enabled))
 			return -EINVAL;
 
 	if (enabled)
@@ -3456,7 +3505,7 @@ static int trace_set_options(struct trace_array *tr, char *option)
 
 	/* If no option could be set, test the specific tracer options */
 	if (!trace_options[i])
-		ret = set_tracer_option(tr->current_trace, cmp, neg);
+		ret = set_tracer_option(tr, cmp, neg);
 
 	mutex_unlock(&trace_types_lock);
 
@@ -3885,10 +3934,26 @@ create_trace_option_files(struct trace_array *tr, struct tracer *tracer);
 static void
 destroy_trace_option_files(struct trace_option_dentry *topts);
 
-static int tracing_set_tracer(const char *buf)
+/*
+ * Used to clear out the tracer before deletion of an instance.
+ * Must have trace_types_lock held.
+ */
+static void tracing_set_nop(struct trace_array *tr)
+{
+	if (tr->current_trace == &nop_trace)
+		return;
+	
+	tr->current_trace->enabled--;
+
+	if (tr->current_trace->reset)
+		tr->current_trace->reset(tr);
+
+	tr->current_trace = &nop_trace;
+}
+
+static int tracing_set_tracer(struct trace_array *tr, const char *buf)
 {
 	static struct trace_option_dentry *topts;
-	struct trace_array *tr = &global_trace;
 	struct tracer *t;
 #ifdef CONFIG_TRACER_MAX_TRACE
 	bool had_max_tr;
@@ -3916,9 +3981,15 @@ static int tracing_set_tracer(const char *buf)
 	if (t == tr->current_trace)
 		goto out;
 
+	/* Some tracers are only allowed for the top level buffer */
+	if (!trace_ok_for_array(t, tr)) {
+		ret = -EINVAL;
+		goto out;
+	}
+
 	trace_branch_disable();
 
-	tr->current_trace->enabled = false;
+	tr->current_trace->enabled--;
 
 	if (tr->current_trace->reset)
 		tr->current_trace->reset(tr);
@@ -3941,9 +4012,11 @@ static int tracing_set_tracer(const char *buf)
 		free_snapshot(tr);
 	}
 #endif
-	destroy_trace_option_files(topts);
-
-	topts = create_trace_option_files(tr, t);
+	/* Currently, only the top instance has options */
+	if (tr->flags & TRACE_ARRAY_FL_GLOBAL) {
+		destroy_trace_option_files(topts);
+		topts = create_trace_option_files(tr, t);
+	}
 
 #ifdef CONFIG_TRACER_MAX_TRACE
 	if (t->use_max_tr && !had_max_tr) {
@@ -3960,7 +4033,7 @@ static int tracing_set_tracer(const char *buf)
 	}
 
 	tr->current_trace = t;
-	tr->current_trace->enabled = true;
+	tr->current_trace->enabled++;
 	trace_branch_enable(tr);
  out:
 	mutex_unlock(&trace_types_lock);
@@ -3972,6 +4045,7 @@ static ssize_t
 tracing_set_trace_write(struct file *filp, const char __user *ubuf,
 			size_t cnt, loff_t *ppos)
 {
+	struct trace_array *tr = filp->private_data;
 	char buf[MAX_TRACER_SIZE+1];
 	int i;
 	size_t ret;
@@ -3991,7 +4065,7 @@ tracing_set_trace_write(struct file *filp, const char __user *ubuf,
 	for (i = cnt - 1; i > 0 && isspace(buf[i]); i--)
 		buf[i] = 0;
 
-	err = tracing_set_tracer(buf);
+	err = tracing_set_tracer(tr, buf);
 	if (err)
 		return err;
 
@@ -4699,25 +4773,10 @@ static int tracing_clock_show(struct seq_file *m, void *v)
 	return 0;
 }
 
-static ssize_t tracing_clock_write(struct file *filp, const char __user *ubuf,
-				   size_t cnt, loff_t *fpos)
+static int tracing_set_clock(struct trace_array *tr, const char *clockstr)
 {
-	struct seq_file *m = filp->private_data;
-	struct trace_array *tr = m->private;
-	char buf[64];
-	const char *clockstr;
 	int i;
 
-	if (cnt >= sizeof(buf))
-		return -EINVAL;
-
-	if (copy_from_user(&buf, ubuf, cnt))
-		return -EFAULT;
-
-	buf[cnt] = 0;
-
-	clockstr = strstrip(buf);
-
 	for (i = 0; i < ARRAY_SIZE(trace_clocks); i++) {
 		if (strcmp(trace_clocks[i].name, clockstr) == 0)
 			break;
@@ -4745,6 +4804,32 @@ static ssize_t tracing_clock_write(struct file *filp, const char __user *ubuf,
 
 	mutex_unlock(&trace_types_lock);
 
+	return 0;
+}
+
+static ssize_t tracing_clock_write(struct file *filp, const char __user *ubuf,
+				   size_t cnt, loff_t *fpos)
+{
+	struct seq_file *m = filp->private_data;
+	struct trace_array *tr = m->private;
+	char buf[64];
+	const char *clockstr;
+	int ret;
+
+	if (cnt >= sizeof(buf))
+		return -EINVAL;
+
+	if (copy_from_user(&buf, ubuf, cnt))
+		return -EFAULT;
+
+	buf[cnt] = 0;
+
+	clockstr = strstrip(buf);
+
+	ret = tracing_set_clock(tr, clockstr);
+	if (ret)
+		return ret;
+
 	*fpos += cnt;
 
 	return cnt;
@@ -5705,7 +5790,7 @@ trace_options_write(struct file *filp, const char __user *ubuf, size_t cnt,
 
 	if (!!(topt->flags->val & topt->opt->bit) != val) {
 		mutex_lock(&trace_types_lock);
-		ret = __set_tracer_option(topt->tr->current_trace, topt->flags,
+		ret = __set_tracer_option(topt->tr, topt->flags,
 					  topt->opt, !val);
 		mutex_unlock(&trace_types_lock);
 		if (ret)
@@ -6112,7 +6197,9 @@ static int instance_delete(const char *name)
 
 	list_del(&tr->list);
 
+	tracing_set_nop(tr);
 	event_trace_del_tracer(tr);
+	ftrace_destroy_function_files(tr);
 	debugfs_remove_recursive(tr->dir);
 	free_percpu(tr->trace_buffer.data);
 	ring_buffer_free(tr->trace_buffer.buffer);
@@ -6207,6 +6294,12 @@ init_tracer_debugfs(struct trace_array *tr, struct dentry *d_tracer)
 {
 	int cpu;
 
+	trace_create_file("available_tracers", 0444, d_tracer,
+			tr, &show_traces_fops);
+
+	trace_create_file("current_tracer", 0644, d_tracer,
+			tr, &set_tracer_fops);
+
 	trace_create_file("tracing_cpumask", 0644, d_tracer,
 			  tr, &tracing_cpumask_fops);
 
@@ -6237,6 +6330,9 @@ init_tracer_debugfs(struct trace_array *tr, struct dentry *d_tracer)
 	trace_create_file("tracing_on", 0644, d_tracer,
 			  tr, &rb_simple_fops);
 
+	if (ftrace_create_function_files(tr, d_tracer))
+		WARN(1, "Could not allocate function filter files");
+
 #ifdef CONFIG_TRACER_SNAPSHOT
 	trace_create_file("snapshot", 0644, d_tracer,
 			  tr, &snapshot_fops);
@@ -6259,12 +6355,6 @@ static __init int tracer_init_debugfs(void)
 
 	init_tracer_debugfs(&global_trace, d_tracer);
 
-	trace_create_file("available_tracers", 0444, d_tracer,
-			&global_trace, &show_traces_fops);
-
-	trace_create_file("current_tracer", 0644, d_tracer,
-			&global_trace, &set_tracer_fops);
-
 #ifdef CONFIG_TRACER_MAX_TRACE
 	trace_create_file("tracing_max_latency", 0644, d_tracer,
 			&tracing_max_latency, &tracing_max_lat_fops);
@@ -6527,6 +6617,13 @@ __init static int tracer_alloc_buffers(void)
 
 	trace_init_cmdlines();
 
+	if (trace_boot_clock) {
+		ret = tracing_set_clock(&global_trace, trace_boot_clock);
+		if (ret < 0)
+			pr_warning("Trace clock %s not defined, going back to default\n",
+				   trace_boot_clock);
+	}
+
 	/*
 	 * register_tracer() might reference current_trace, so it
 	 * needs to be set before we register anything. This is