Merge tag 'trace-v5.6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:

 - Added new "bootconfig".

   This looks for a file appended to initrd to add boot config options,
   and has been discussed thoroughly at Linux Plumbers.

   Very useful for adding kprobes at bootup.

   Only enabled if "bootconfig" is on the real kernel command line.

 - Created dynamic event creation.

   Merges common code between creating synthetic events and kprobe
   events.

 - Rename perf "ring_buffer" structure to "perf_buffer"

 - Rename ftrace "ring_buffer" structure to "trace_buffer"

   Had to rename existing "trace_buffer" to "array_buffer"

 - Allow trace_printk() to work withing (some) tracing code.

 - Sort of tracing configs to be a little better organized

 - Fixed bug where ftrace_graph hash was not being protected properly

 - Various other small fixes and clean ups

* tag 'trace-v5.6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (88 commits)
  bootconfig: Show the number of nodes on boot message
  tools/bootconfig: Show the number of bootconfig nodes
  bootconfig: Add more parse error messages
  bootconfig: Use bootconfig instead of boot config
  ftrace: Protect ftrace_graph_hash with ftrace_sync
  ftrace: Add comment to why rcu_dereference_sched() is open coded
  tracing: Annotate ftrace_graph_notrace_hash pointer with __rcu
  tracing: Annotate ftrace_graph_hash pointer with __rcu
  bootconfig: Only load bootconfig if "bootconfig" is on the kernel cmdline
  tracing: Use seq_buf for building dynevent_cmd string
  tracing: Remove useless code in dynevent_arg_pair_add()
  tracing: Remove check_arg() callbacks from dynevent args
  tracing: Consolidate some synth_event_trace code
  tracing: Fix now invalid var_ref_vals assumption in trace action
  tracing: Change trace_boot to use synth_event interface
  tracing: Move tracing selftests to bottom of menu
  tracing: Move mmio tracer config up with the other tracers
  tracing: Move tracing test module configs together
  tracing: Move all function tracing configs together
  tracing: Documentation for in-kernel synthetic event API
  ...

1 files changed, 258 insertions, 195 deletions

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 5e02d65505c1..c797a15a1fc7 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -162,8 +162,8 @@ union trace_eval_map_item {
 static union trace_eval_map_item *trace_eval_maps;
 #endif /* CONFIG_TRACE_EVAL_MAP_FILE */
 
-static int tracing_set_tracer(struct trace_array *tr, const char *buf);
-static void ftrace_trace_userstack(struct ring_buffer *buffer,
+int tracing_set_tracer(struct trace_array *tr, const char *buf);
+static void ftrace_trace_userstack(struct trace_buffer *buffer,
 				   unsigned long flags, int pc);
 
 #define MAX_TRACER_SIZE		100
@@ -338,7 +338,7 @@ int tracing_check_open_get_tr(struct trace_array *tr)
 }
 
 int call_filter_check_discard(struct trace_event_call *call, void *rec,
-			      struct ring_buffer *buffer,
+			      struct trace_buffer *buffer,
 			      struct ring_buffer_event *event)
 {
 	if (unlikely(call->flags & TRACE_EVENT_FL_FILTERED) &&
@@ -603,7 +603,7 @@ int trace_pid_write(struct trace_pid_list *filtered_pids,
 	return read;
 }
 
-static u64 buffer_ftrace_now(struct trace_buffer *buf, int cpu)
+static u64 buffer_ftrace_now(struct array_buffer *buf, int cpu)
 {
 	u64 ts;
 
@@ -619,7 +619,7 @@ static u64 buffer_ftrace_now(struct trace_buffer *buf, int cpu)
 
 u64 ftrace_now(int cpu)
 {
-	return buffer_ftrace_now(&global_trace.trace_buffer, cpu);
+	return buffer_ftrace_now(&global_trace.array_buffer, cpu);
 }
 
 /**
@@ -747,22 +747,22 @@ static inline void trace_access_lock_init(void)
 #endif
 
 #ifdef CONFIG_STACKTRACE
-static void __ftrace_trace_stack(struct ring_buffer *buffer,
+static void __ftrace_trace_stack(struct trace_buffer *buffer,
 				 unsigned long flags,
 				 int skip, int pc, struct pt_regs *regs);
 static inline void ftrace_trace_stack(struct trace_array *tr,
-				      struct ring_buffer *buffer,
+				      struct trace_buffer *buffer,
 				      unsigned long flags,
 				      int skip, int pc, struct pt_regs *regs);
 
 #else
-static inline void __ftrace_trace_stack(struct ring_buffer *buffer,
+static inline void __ftrace_trace_stack(struct trace_buffer *buffer,
 					unsigned long flags,
 					int skip, int pc, struct pt_regs *regs)
 {
 }
 static inline void ftrace_trace_stack(struct trace_array *tr,
-				      struct ring_buffer *buffer,
+				      struct trace_buffer *buffer,
 				      unsigned long flags,
 				      int skip, int pc, struct pt_regs *regs)
 {
@@ -780,7 +780,7 @@ trace_event_setup(struct ring_buffer_event *event,
 }
 
 static __always_inline struct ring_buffer_event *
-__trace_buffer_lock_reserve(struct ring_buffer *buffer,
+__trace_buffer_lock_reserve(struct trace_buffer *buffer,
 			  int type,
 			  unsigned long len,
 			  unsigned long flags, int pc)
@@ -796,8 +796,8 @@ __trace_buffer_lock_reserve(struct ring_buffer *buffer,
 
 void tracer_tracing_on(struct trace_array *tr)
 {
-	if (tr->trace_buffer.buffer)
-		ring_buffer_record_on(tr->trace_buffer.buffer);
+	if (tr->array_buffer.buffer)
+		ring_buffer_record_on(tr->array_buffer.buffer);
 	/*
 	 * This flag is looked at when buffers haven't been allocated
 	 * yet, or by some tracers (like irqsoff), that just want to
@@ -825,7 +825,7 @@ EXPORT_SYMBOL_GPL(tracing_on);
 
 
 static __always_inline void
-__buffer_unlock_commit(struct ring_buffer *buffer, struct ring_buffer_event *event)
+__buffer_unlock_commit(struct trace_buffer *buffer, struct ring_buffer_event *event)
 {
 	__this_cpu_write(trace_taskinfo_save, true);
 
@@ -848,7 +848,7 @@ __buffer_unlock_commit(struct ring_buffer *buffer, struct ring_buffer_event *eve
 int __trace_puts(unsigned long ip, const char *str, int size)
 {
 	struct ring_buffer_event *event;
-	struct ring_buffer *buffer;
+	struct trace_buffer *buffer;
 	struct print_entry *entry;
 	unsigned long irq_flags;
 	int alloc;
@@ -865,11 +865,14 @@ int __trace_puts(unsigned long ip, const char *str, int size)
 	alloc = sizeof(*entry) + size + 2; /* possible \n added */
 
 	local_save_flags(irq_flags);
-	buffer = global_trace.trace_buffer.buffer;
+	buffer = global_trace.array_buffer.buffer;
+	ring_buffer_nest_start(buffer);
 	event = __trace_buffer_lock_reserve(buffer, TRACE_PRINT, alloc, 
 					    irq_flags, pc);
-	if (!event)
-		return 0;
+	if (!event) {
+		size = 0;
+		goto out;
+	}
 
 	entry = ring_buffer_event_data(event);
 	entry->ip = ip;
@@ -885,7 +888,8 @@ int __trace_puts(unsigned long ip, const char *str, int size)
 
 	__buffer_unlock_commit(buffer, event);
 	ftrace_trace_stack(&global_trace, buffer, irq_flags, 4, pc, NULL);
-
+ out:
+	ring_buffer_nest_end(buffer);
 	return size;
 }
 EXPORT_SYMBOL_GPL(__trace_puts);
@@ -898,10 +902,11 @@ EXPORT_SYMBOL_GPL(__trace_puts);
 int __trace_bputs(unsigned long ip, const char *str)
 {
 	struct ring_buffer_event *event;
-	struct ring_buffer *buffer;
+	struct trace_buffer *buffer;
 	struct bputs_entry *entry;
 	unsigned long irq_flags;
 	int size = sizeof(struct bputs_entry);
+	int ret = 0;
 	int pc;
 
 	if (!(global_trace.trace_flags & TRACE_ITER_PRINTK))
@@ -913,11 +918,13 @@ int __trace_bputs(unsigned long ip, const char *str)
 		return 0;
 
 	local_save_flags(irq_flags);
-	buffer = global_trace.trace_buffer.buffer;
+	buffer = global_trace.array_buffer.buffer;
+
+	ring_buffer_nest_start(buffer);
 	event = __trace_buffer_lock_reserve(buffer, TRACE_BPUTS, size,
 					    irq_flags, pc);
 	if (!event)
-		return 0;
+		goto out;
 
 	entry = ring_buffer_event_data(event);
 	entry->ip			= ip;
@@ -926,7 +933,10 @@ int __trace_bputs(unsigned long ip, const char *str)
 	__buffer_unlock_commit(buffer, event);
 	ftrace_trace_stack(&global_trace, buffer, irq_flags, 4, pc, NULL);
 
-	return 1;
+	ret = 1;
+ out:
+	ring_buffer_nest_end(buffer);
+	return ret;
 }
 EXPORT_SYMBOL_GPL(__trace_bputs);
 
@@ -1036,9 +1046,9 @@ void *tracing_cond_snapshot_data(struct trace_array *tr)
 }
 EXPORT_SYMBOL_GPL(tracing_cond_snapshot_data);
 
-static int resize_buffer_duplicate_size(struct trace_buffer *trace_buf,
-					struct trace_buffer *size_buf, int cpu_id);
-static void set_buffer_entries(struct trace_buffer *buf, unsigned long val);
+static int resize_buffer_duplicate_size(struct array_buffer *trace_buf,
+					struct array_buffer *size_buf, int cpu_id);
+static void set_buffer_entries(struct array_buffer *buf, unsigned long val);
 
 int tracing_alloc_snapshot_instance(struct trace_array *tr)
 {
@@ -1048,7 +1058,7 @@ int tracing_alloc_snapshot_instance(struct trace_array *tr)
 
 		/* allocate spare buffer */
 		ret = resize_buffer_duplicate_size(&tr->max_buffer,
-				   &tr->trace_buffer, RING_BUFFER_ALL_CPUS);
+				   &tr->array_buffer, RING_BUFFER_ALL_CPUS);
 		if (ret < 0)
 			return ret;
 
@@ -1251,8 +1261,8 @@ EXPORT_SYMBOL_GPL(tracing_snapshot_cond_disable);
 
 void tracer_tracing_off(struct trace_array *tr)
 {
-	if (tr->trace_buffer.buffer)
-		ring_buffer_record_off(tr->trace_buffer.buffer);
+	if (tr->array_buffer.buffer)
+		ring_buffer_record_off(tr->array_buffer.buffer);
 	/*
 	 * This flag is looked at when buffers haven't been allocated
 	 * yet, or by some tracers (like irqsoff), that just want to
@@ -1294,8 +1304,8 @@ void disable_trace_on_warning(void)
  */
 bool tracer_tracing_is_on(struct trace_array *tr)
 {
-	if (tr->trace_buffer.buffer)
-		return ring_buffer_record_is_on(tr->trace_buffer.buffer);
+	if (tr->array_buffer.buffer)
+		return ring_buffer_record_is_on(tr->array_buffer.buffer);
 	return !tr->buffer_disabled;
 }
 
@@ -1590,8 +1600,8 @@ void latency_fsnotify(struct trace_array *tr)
 static void
 __update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu)
 {
-	struct trace_buffer *trace_buf = &tr->trace_buffer;
-	struct trace_buffer *max_buf = &tr->max_buffer;
+	struct array_buffer *trace_buf = &tr->array_buffer;
+	struct array_buffer *max_buf = &tr->max_buffer;
 	struct trace_array_cpu *data = per_cpu_ptr(trace_buf->data, cpu);
 	struct trace_array_cpu *max_data = per_cpu_ptr(max_buf->data, cpu);
 
@@ -1649,8 +1659,8 @@ update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu,
 
 	arch_spin_lock(&tr->max_lock);
 
-	/* Inherit the recordable setting from trace_buffer */
-	if (ring_buffer_record_is_set_on(tr->trace_buffer.buffer))
+	/* Inherit the recordable setting from array_buffer */
+	if (ring_buffer_record_is_set_on(tr->array_buffer.buffer))
 		ring_buffer_record_on(tr->max_buffer.buffer);
 	else
 		ring_buffer_record_off(tr->max_buffer.buffer);
@@ -1659,7 +1669,7 @@ update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu,
 	if (tr->cond_snapshot && !tr->cond_snapshot->update(tr, cond_data))
 		goto out_unlock;
 #endif
-	swap(tr->trace_buffer.buffer, tr->max_buffer.buffer);
+	swap(tr->array_buffer.buffer, tr->max_buffer.buffer);
 
 	__update_max_tr(tr, tsk, cpu);
 
@@ -1692,7 +1702,7 @@ update_max_tr_single(struct trace_array *tr, struct task_struct *tsk, int cpu)
 
 	arch_spin_lock(&tr->max_lock);
 
-	ret = ring_buffer_swap_cpu(tr->max_buffer.buffer, tr->trace_buffer.buffer, cpu);
+	ret = ring_buffer_swap_cpu(tr->max_buffer.buffer, tr->array_buffer.buffer, cpu);
 
 	if (ret == -EBUSY) {
 		/*
@@ -1718,7 +1728,7 @@ static int wait_on_pipe(struct trace_iterator *iter, int full)
 	if (trace_buffer_iter(iter, iter->cpu_file))
 		return 0;
 
-	return ring_buffer_wait(iter->trace_buffer->buffer, iter->cpu_file,
+	return ring_buffer_wait(iter->array_buffer->buffer, iter->cpu_file,
 				full);
 }
 
@@ -1769,7 +1779,7 @@ static int run_tracer_selftest(struct tracer *type)
 	 * internal tracing to verify that everything is in order.
 	 * If we fail, we do not register this tracer.
 	 */
-	tracing_reset_online_cpus(&tr->trace_buffer);
+	tracing_reset_online_cpus(&tr->array_buffer);
 
 	tr->current_trace = type;
 
@@ -1795,7 +1805,7 @@ static int run_tracer_selftest(struct tracer *type)
 		return -1;
 	}
 	/* Only reset on passing, to avoid touching corrupted buffers */
-	tracing_reset_online_cpus(&tr->trace_buffer);
+	tracing_reset_online_cpus(&tr->array_buffer);
 
 #ifdef CONFIG_TRACER_MAX_TRACE
 	if (type->use_max_tr) {
@@ -1962,9 +1972,9 @@ int __init register_tracer(struct tracer *type)
 	return ret;
 }
 
-static void tracing_reset_cpu(struct trace_buffer *buf, int cpu)
+static void tracing_reset_cpu(struct array_buffer *buf, int cpu)
 {
-	struct ring_buffer *buffer = buf->buffer;
+	struct trace_buffer *buffer = buf->buffer;
 
 	if (!buffer)
 		return;
@@ -1978,9 +1988,9 @@ static void tracing_reset_cpu(struct trace_buffer *buf, int cpu)
 	ring_buffer_record_enable(buffer);
 }
 
-void tracing_reset_online_cpus(struct trace_buffer *buf)
+void tracing_reset_online_cpus(struct array_buffer *buf)
 {
-	struct ring_buffer *buffer = buf->buffer;
+	struct trace_buffer *buffer = buf->buffer;
 	int cpu;
 
 	if (!buffer)
@@ -2008,7 +2018,7 @@ void tracing_reset_all_online_cpus(void)
 		if (!tr->clear_trace)
 			continue;
 		tr->clear_trace = false;
-		tracing_reset_online_cpus(&tr->trace_buffer);
+		tracing_reset_online_cpus(&tr->array_buffer);
 #ifdef CONFIG_TRACER_MAX_TRACE
 		tracing_reset_online_cpus(&tr->max_buffer);
 #endif
@@ -2098,7 +2108,7 @@ int is_tracing_stopped(void)
  */
 void tracing_start(void)
 {
-	struct ring_buffer *buffer;
+	struct trace_buffer *buffer;
 	unsigned long flags;
 
 	if (tracing_disabled)
@@ -2117,7 +2127,7 @@ void tracing_start(void)
 	/* Prevent the buffers from switching */
 	arch_spin_lock(&global_trace.max_lock);
 
-	buffer = global_trace.trace_buffer.buffer;
+	buffer = global_trace.array_buffer.buffer;
 	if (buffer)
 		ring_buffer_record_enable(buffer);
 
@@ -2135,7 +2145,7 @@ void tracing_start(void)
 
 static void tracing_start_tr(struct trace_array *tr)
 {
-	struct ring_buffer *buffer;
+	struct trace_buffer *buffer;
 	unsigned long flags;
 
 	if (tracing_disabled)
@@ -2156,7 +2166,7 @@ static void tracing_start_tr(struct trace_array *tr)
 		goto out;
 	}
 
-	buffer = tr->trace_buffer.buffer;
+	buffer = tr->array_buffer.buffer;
 	if (buffer)
 		ring_buffer_record_enable(buffer);
 
@@ -2172,7 +2182,7 @@ static void tracing_start_tr(struct trace_array *tr)
  */
 void tracing_stop(void)
 {
-	struct ring_buffer *buffer;
+	struct trace_buffer *buffer;
 	unsigned long flags;
 
 	raw_spin_lock_irqsave(&global_trace.start_lock, flags);
@@ -2182,7 +2192,7 @@ void tracing_stop(void)
 	/* Prevent the buffers from switching */
 	arch_spin_lock(&global_trace.max_lock);
 
-	buffer = global_trace.trace_buffer.buffer;
+	buffer = global_trace.array_buffer.buffer;
 	if (buffer)
 		ring_buffer_record_disable(buffer);
 
@@ -2200,7 +2210,7 @@ void tracing_stop(void)
 
 static void tracing_stop_tr(struct trace_array *tr)
 {
-	struct ring_buffer *buffer;
+	struct trace_buffer *buffer;
 	unsigned long flags;
 
 	/* If global, we need to also stop the max tracer */
@@ -2211,7 +2221,7 @@ static void tracing_stop_tr(struct trace_array *tr)
 	if (tr->stop_count++)
 		goto out;
 
-	buffer = tr->trace_buffer.buffer;
+	buffer = tr->array_buffer.buffer;
 	if (buffer)
 		ring_buffer_record_disable(buffer);
 
@@ -2442,7 +2452,7 @@ tracing_generic_entry_update(struct trace_entry *entry, unsigned short type,
 EXPORT_SYMBOL_GPL(tracing_generic_entry_update);
 
 struct ring_buffer_event *
-trace_buffer_lock_reserve(struct ring_buffer *buffer,
+trace_buffer_lock_reserve(struct trace_buffer *buffer,
 			  int type,
 			  unsigned long len,
 			  unsigned long flags, int pc)
@@ -2561,10 +2571,10 @@ void trace_buffered_event_disable(void)
 	preempt_enable();
 }
 
-static struct ring_buffer *temp_buffer;
+static struct trace_buffer *temp_buffer;
 
 struct ring_buffer_event *
-trace_event_buffer_lock_reserve(struct ring_buffer **current_rb,
+trace_event_buffer_lock_reserve(struct trace_buffer **current_rb,
 			  struct trace_event_file *trace_file,
 			  int type, unsigned long len,
 			  unsigned long flags, int pc)
@@ -2572,7 +2582,7 @@ trace_event_buffer_lock_reserve(struct ring_buffer **current_rb,
 	struct ring_buffer_event *entry;
 	int val;
 
-	*current_rb = trace_file->tr->trace_buffer.buffer;
+	*current_rb = trace_file->tr->array_buffer.buffer;
 
 	if (!ring_buffer_time_stamp_abs(*current_rb) && (trace_file->flags &
 	     (EVENT_FILE_FL_SOFT_DISABLED | EVENT_FILE_FL_FILTERED)) &&
@@ -2610,6 +2620,7 @@ static DEFINE_MUTEX(tracepoint_printk_mutex);
 static void output_printk(struct trace_event_buffer *fbuffer)
 {
 	struct trace_event_call *event_call;
+	struct trace_event_file *file;
 	struct trace_event *event;
 	unsigned long flags;
 	struct trace_iterator *iter = tracepoint_print_iter;
@@ -2623,6 +2634,12 @@ static void output_printk(struct trace_event_buffer *fbuffer)
 	    !event_call->event.funcs->trace)
 		return;
 
+	file = fbuffer->trace_file;
+	if (test_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags) ||
+	    (unlikely(file->flags & EVENT_FILE_FL_FILTERED) &&
+	     !filter_match_preds(file->filter, fbuffer->entry)))
+		return;
+
 	event = &fbuffer->trace_file->event_call->event;
 
 	spin_lock_irqsave(&tracepoint_iter_lock, flags);
@@ -2673,9 +2690,9 @@ void trace_event_buffer_commit(struct trace_event_buffer *fbuffer)
 	if (static_key_false(&tracepoint_printk_key.key))
 		output_printk(fbuffer);
 
-	event_trigger_unlock_commit(fbuffer->trace_file, fbuffer->buffer,
+	event_trigger_unlock_commit_regs(fbuffer->trace_file, fbuffer->buffer,
 				    fbuffer->event, fbuffer->entry,
-				    fbuffer->flags, fbuffer->pc);
+				    fbuffer->flags, fbuffer->pc, fbuffer->regs);
 }
 EXPORT_SYMBOL_GPL(trace_event_buffer_commit);
 
@@ -2689,7 +2706,7 @@ EXPORT_SYMBOL_GPL(trace_event_buffer_commit);
 # define STACK_SKIP 3
 
 void trace_buffer_unlock_commit_regs(struct trace_array *tr,
-				     struct ring_buffer *buffer,
+				     struct trace_buffer *buffer,
 				     struct ring_buffer_event *event,
 				     unsigned long flags, int pc,
 				     struct pt_regs *regs)
@@ -2710,7 +2727,7 @@ void trace_buffer_unlock_commit_regs(struct trace_array *tr,
  * Similar to trace_buffer_unlock_commit_regs() but do not dump stack.
  */
 void
-trace_buffer_unlock_commit_nostack(struct ring_buffer *buffer,
+trace_buffer_unlock_commit_nostack(struct trace_buffer *buffer,
 				   struct ring_buffer_event *event)
 {
 	__buffer_unlock_commit(buffer, event);
@@ -2845,7 +2862,7 @@ trace_function(struct trace_array *tr,
 	       int pc)
 {
 	struct trace_event_call *call = &event_function;
-	struct ring_buffer *buffer = tr->trace_buffer.buffer;
+	struct trace_buffer *buffer = tr->array_buffer.buffer;
 	struct ring_buffer_event *event;
 	struct ftrace_entry *entry;
 
@@ -2883,7 +2900,7 @@ struct ftrace_stacks {
 static DEFINE_PER_CPU(struct ftrace_stacks, ftrace_stacks);
 static DEFINE_PER_CPU(int, ftrace_stack_reserve);
 
-static void __ftrace_trace_stack(struct ring_buffer *buffer,
+static void __ftrace_trace_stack(struct trace_buffer *buffer,
 				 unsigned long flags,
 				 int skip, int pc, struct pt_regs *regs)
 {
@@ -2958,7 +2975,7 @@ static void __ftrace_trace_stack(struct ring_buffer *buffer,
 }
 
 static inline void ftrace_trace_stack(struct trace_array *tr,
-				      struct ring_buffer *buffer,
+				      struct trace_buffer *buffer,
 				      unsigned long flags,
 				      int skip, int pc, struct pt_regs *regs)
 {
@@ -2971,7 +2988,7 @@ static inline void ftrace_trace_stack(struct trace_array *tr,
 void __trace_stack(struct trace_array *tr, unsigned long flags, int skip,
 		   int pc)
 {
-	struct ring_buffer *buffer = tr->trace_buffer.buffer;
+	struct trace_buffer *buffer = tr->array_buffer.buffer;
 
 	if (rcu_is_watching()) {
 		__ftrace_trace_stack(buffer, flags, skip, pc, NULL);
@@ -3009,7 +3026,7 @@ void trace_dump_stack(int skip)
 	/* Skip 1 to skip this function. */
 	skip++;
 #endif
-	__ftrace_trace_stack(global_trace.trace_buffer.buffer,
+	__ftrace_trace_stack(global_trace.array_buffer.buffer,
 			     flags, skip, preempt_count(), NULL);
 }
 EXPORT_SYMBOL_GPL(trace_dump_stack);
@@ -3018,7 +3035,7 @@ EXPORT_SYMBOL_GPL(trace_dump_stack);
 static DEFINE_PER_CPU(int, user_stack_count);
 
 static void
-ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags, int pc)
+ftrace_trace_userstack(struct trace_buffer *buffer, unsigned long flags, int pc)
 {
 	struct trace_event_call *call = &event_user_stack;
 	struct ring_buffer_event *event;
@@ -3063,7 +3080,7 @@ ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags, int pc)
 	preempt_enable();
 }
 #else /* CONFIG_USER_STACKTRACE_SUPPORT */
-static void ftrace_trace_userstack(struct ring_buffer *buffer,
+static void ftrace_trace_userstack(struct trace_buffer *buffer,
 				   unsigned long flags, int pc)
 {
 }
@@ -3109,7 +3126,7 @@ static int alloc_percpu_trace_buffer(void)
 	struct trace_buffer_struct *buffers;
 
 	buffers = alloc_percpu(struct trace_buffer_struct);
-	if (WARN(!buffers, "Could not allocate percpu trace_printk buffer"))
+	if (MEM_FAIL(!buffers, "Could not allocate percpu trace_printk buffer"))
 		return -ENOMEM;
 
 	trace_percpu_buffer = buffers;
@@ -3154,7 +3171,7 @@ void trace_printk_init_buffers(void)
 	 * directly here. If the global_trace.buffer is already
 	 * allocated here, then this was called by module code.
 	 */
-	if (global_trace.trace_buffer.buffer)
+	if (global_trace.array_buffer.buffer)
 		tracing_start_cmdline_record();
 }
 EXPORT_SYMBOL_GPL(trace_printk_init_buffers);
@@ -3188,7 +3205,7 @@ int trace_vbprintk(unsigned long ip, const char *fmt, va_list args)
 {
 	struct trace_event_call *call = &event_bprint;
 	struct ring_buffer_event *event;
-	struct ring_buffer *buffer;
+	struct trace_buffer *buffer;
 	struct trace_array *tr = &global_trace;
 	struct bprint_entry *entry;
 	unsigned long flags;
@@ -3213,11 +3230,12 @@ int trace_vbprintk(unsigned long ip, const char *fmt, va_list args)
 	len = vbin_printf((u32 *)tbuffer, TRACE_BUF_SIZE/sizeof(int), fmt, args);
 
 	if (len > TRACE_BUF_SIZE/sizeof(int) || len < 0)
-		goto out;
+		goto out_put;
 
 	local_save_flags(flags);
 	size = sizeof(*entry) + sizeof(u32) * len;
-	buffer = tr->trace_buffer.buffer;
+	buffer = tr->array_buffer.buffer;
+	ring_buffer_nest_start(buffer);
 	event = __trace_buffer_lock_reserve(buffer, TRACE_BPRINT, size,
 					    flags, pc);
 	if (!event)
@@ -3233,6 +3251,8 @@ int trace_vbprintk(unsigned long ip, const char *fmt, va_list args)
 	}
 
 out:
+	ring_buffer_nest_end(buffer);
+out_put:
 	put_trace_buf();
 
 out_nobuffer:
@@ -3245,7 +3265,7 @@ EXPORT_SYMBOL_GPL(trace_vbprintk);
 
 __printf(3, 0)
 static int
-__trace_array_vprintk(struct ring_buffer *buffer,
+__trace_array_vprintk(struct trace_buffer *buffer,
 		      unsigned long ip, const char *fmt, va_list args)
 {
 	struct trace_event_call *call = &event_print;
@@ -3275,6 +3295,7 @@ __trace_array_vprintk(struct ring_buffer *buffer,
 
 	local_save_flags(flags);
 	size = sizeof(*entry) + len + 1;
+	ring_buffer_nest_start(buffer);
 	event = __trace_buffer_lock_reserve(buffer, TRACE_PRINT, size,
 					    flags, pc);
 	if (!event)
@@ -3289,6 +3310,7 @@ __trace_array_vprintk(struct ring_buffer *buffer,
 	}
 
 out:
+	ring_buffer_nest_end(buffer);
 	put_trace_buf();
 
 out_nobuffer:
@@ -3302,7 +3324,7 @@ __printf(3, 0)
 int trace_array_vprintk(struct trace_array *tr,
 			unsigned long ip, const char *fmt, va_list args)
 {
-	return __trace_array_vprintk(tr->trace_buffer.buffer, ip, fmt, args);
+	return __trace_array_vprintk(tr->array_buffer.buffer, ip, fmt, args);
 }
 
 __printf(3, 0)
@@ -3326,7 +3348,7 @@ int trace_array_printk(struct trace_array *tr,
 EXPORT_SYMBOL_GPL(trace_array_printk);
 
 __printf(3, 4)
-int trace_array_printk_buf(struct ring_buffer *buffer,
+int trace_array_printk_buf(struct trace_buffer *buffer,
 			   unsigned long ip, const char *fmt, ...)
 {
 	int ret;
@@ -3367,7 +3389,7 @@ peek_next_entry(struct trace_iterator *iter, int cpu, u64 *ts,
 	if (buf_iter)
 		event = ring_buffer_iter_peek(buf_iter, ts);
 	else
-		event = ring_buffer_peek(iter->trace_buffer->buffer, cpu, ts,
+		event = ring_buffer_peek(iter->array_buffer->buffer, cpu, ts,
 					 lost_events);
 
 	if (event) {
@@ -3382,7 +3404,7 @@ static struct trace_entry *
 __find_next_entry(struct trace_iterator *iter, int *ent_cpu,
 		  unsigned long *missing_events, u64 *ent_ts)
 {
-	struct ring_buffer *buffer = iter->trace_buffer->buffer;
+	struct trace_buffer *buffer = iter->array_buffer->buffer;
 	struct trace_entry *ent, *next = NULL;
 	unsigned long lost_events = 0, next_lost = 0;
 	int cpu_file = iter->cpu_file;
@@ -3459,7 +3481,7 @@ void *trace_find_next_entry_inc(struct trace_iterator *iter)
 
 static void trace_consume(struct trace_iterator *iter)
 {
-	ring_buffer_consume(iter->trace_buffer->buffer, iter->cpu, &iter->ts,
+	ring_buffer_consume(iter->array_buffer->buffer, iter->cpu, &iter->ts,
 			    &iter->lost_events);
 }
 
@@ -3497,7 +3519,7 @@ void tracing_iter_reset(struct trace_iterator *iter, int cpu)
 	unsigned long entries = 0;
 	u64 ts;
 
-	per_cpu_ptr(iter->trace_buffer->data, cpu)->skipped_entries = 0;
+	per_cpu_ptr(iter->array_buffer->data, cpu)->skipped_entries = 0;
 
 	buf_iter = trace_buffer_iter(iter, cpu);
 	if (!buf_iter)
@@ -3511,13 +3533,13 @@ void tracing_iter_reset(struct trace_iterator *iter, int cpu)
 	 * by the timestamp being before the start of the buffer.
 	 */
 	while ((event = ring_buffer_iter_peek(buf_iter, &ts))) {
-		if (ts >= iter->trace_buffer->time_start)
+		if (ts >= iter->array_buffer->time_start)
 			break;
 		entries++;
 		ring_buffer_read(buf_iter, NULL);
 	}
 
-	per_cpu_ptr(iter->trace_buffer->data, cpu)->skipped_entries = entries;
+	per_cpu_ptr(iter->array_buffer->data, cpu)->skipped_entries = entries;
 }
 
 /*
@@ -3602,7 +3624,7 @@ static void s_stop(struct seq_file *m, void *p)
 }
 
 static void
-get_total_entries_cpu(struct trace_buffer *buf, unsigned long *total,
+get_total_entries_cpu(struct array_buffer *buf, unsigned long *total,
 		      unsigned long *entries, int cpu)
 {
 	unsigned long count;
@@ -3624,7 +3646,7 @@ get_total_entries_cpu(struct trace_buffer *buf, unsigned long *total,
 }
 
 static void
-get_total_entries(struct trace_buffer *buf,
+get_total_entries(struct array_buffer *buf,
 		  unsigned long *total, unsigned long *entries)
 {
 	unsigned long t, e;
@@ -3647,7 +3669,7 @@ unsigned long trace_total_entries_cpu(struct trace_array *tr, int cpu)
 	if (!tr)
 		tr = &global_trace;
 
-	get_total_entries_cpu(&tr->trace_buffer, &total, &entries, cpu);
+	get_total_entries_cpu(&tr->array_buffer, &total, &entries, cpu);
 
 	return entries;
 }
@@ -3659,7 +3681,7 @@ unsigned long trace_total_entries(struct trace_array *tr)
 	if (!tr)
 		tr = &global_trace;
 
-	get_total_entries(&tr->trace_buffer, &total, &entries);
+	get_total_entries(&tr->array_buffer, &total, &entries);
 
 	return entries;
 }
@@ -3676,7 +3698,7 @@ static void print_lat_help_header(struct seq_file *m)
 		    "#     \\   /      |||||  \\    |   /         \n");
 }
 
-static void print_event_info(struct trace_buffer *buf, struct seq_file *m)
+static void print_event_info(struct array_buffer *buf, struct seq_file *m)
 {
 	unsigned long total;
 	unsigned long entries;
@@ -3687,7 +3709,7 @@ static void print_event_info(struct trace_buffer *buf, struct seq_file *m)
 	seq_puts(m, "#\n");
 }
 
-static void print_func_help_header(struct trace_buffer *buf, struct seq_file *m,
+static void print_func_help_header(struct array_buffer *buf, struct seq_file *m,
 				   unsigned int flags)
 {
 	bool tgid = flags & TRACE_ITER_RECORD_TGID;
@@ -3698,7 +3720,7 @@ static void print_func_help_header(struct trace_buffer *buf, struct seq_file *m,
 	seq_printf(m, "#              | |     %s    |       |         |\n",	 tgid ? "  |      " : "");
 }
 
-static void print_func_help_header_irq(struct trace_buffer *buf, struct seq_file *m,
+static void print_func_help_header_irq(struct array_buffer *buf, struct seq_file *m,
 				       unsigned int flags)
 {
 	bool tgid = flags & TRACE_ITER_RECORD_TGID;
@@ -3720,7 +3742,7 @@ void
 print_trace_header(struct seq_file *m, struct trace_iterator *iter)
 {
 	unsigned long sym_flags = (global_trace.trace_flags & TRACE_ITER_SYM_MASK);
-	struct trace_buffer *buf = iter->trace_buffer;
+	struct array_buffer *buf = iter->array_buffer;
 	struct trace_array_cpu *data = per_cpu_ptr(buf->data, buf->cpu);
 	struct tracer *type = iter->trace;
 	unsigned long entries;
@@ -3795,7 +3817,7 @@ static void test_cpu_buff_start(struct trace_iterator *iter)
 	    cpumask_test_cpu(iter->cpu, iter->started))
 		return;
 
-	if (per_cpu_ptr(iter->trace_buffer->data, iter->cpu)->skipped_entries)
+	if (per_cpu_ptr(iter->array_buffer->data, iter->cpu)->skipped_entries)
 		return;
 
 	if (cpumask_available(iter->started))
@@ -3929,7 +3951,7 @@ int trace_empty(struct trace_iterator *iter)
 			if (!ring_buffer_iter_empty(buf_iter))
 				return 0;
 		} else {
-			if (!ring_buffer_empty_cpu(iter->trace_buffer->buffer, cpu))
+			if (!ring_buffer_empty_cpu(iter->array_buffer->buffer, cpu))
 				return 0;
 		}
 		return 1;
@@ -3941,7 +3963,7 @@ int trace_empty(struct trace_iterator *iter)
 			if (!ring_buffer_iter_empty(buf_iter))
 				return 0;
 		} else {
-			if (!ring_buffer_empty_cpu(iter->trace_buffer->buffer, cpu))
+			if (!ring_buffer_empty_cpu(iter->array_buffer->buffer, cpu))
 				return 0;
 		}
 	}
@@ -4031,10 +4053,10 @@ void trace_default_header(struct seq_file *m)
 	} else {
 		if (!(trace_flags & TRACE_ITER_VERBOSE)) {
 			if (trace_flags & TRACE_ITER_IRQ_INFO)
-				print_func_help_header_irq(iter->trace_buffer,
+				print_func_help_header_irq(iter->array_buffer,
 							   m, trace_flags);
 			else
-				print_func_help_header(iter->trace_buffer, m,
+				print_func_help_header(iter->array_buffer, m,
 						       trace_flags);
 		}
 	}
@@ -4192,21 +4214,21 @@ __tracing_open(struct inode *inode, struct file *file, bool snapshot)
 #ifdef CONFIG_TRACER_MAX_TRACE
 	/* Currently only the top directory has a snapshot */
 	if (tr->current_trace->print_max || snapshot)
-		iter->trace_buffer = &tr->max_buffer;
+		iter->array_buffer = &tr->max_buffer;
 	else
 #endif
-		iter->trace_buffer = &tr->trace_buffer;
+		iter->array_buffer = &tr->array_buffer;
 	iter->snapshot = snapshot;
 	iter->pos = -1;
 	iter->cpu_file = tracing_get_cpu(inode);
 	mutex_init(&iter->mutex);
 
 	/* Notify the tracer early; before we stop tracing. */
-	if (iter->trace && iter->trace->open)
+	if (iter->trace->open)
 		iter->trace->open(iter);
 
 	/* Annotate start of buffers if we had overruns */
-	if (ring_buffer_overruns(iter->trace_buffer->buffer))
+	if (ring_buffer_overruns(iter->array_buffer->buffer))
 		iter->iter_flags |= TRACE_FILE_ANNOTATE;
 
 	/* Output in nanoseconds only if we are using a clock in nanoseconds. */
@@ -4220,7 +4242,7 @@ __tracing_open(struct inode *inode, struct file *file, bool snapshot)
 	if (iter->cpu_file == RING_BUFFER_ALL_CPUS) {
 		for_each_tracing_cpu(cpu) {
 			iter->buffer_iter[cpu] =
-				ring_buffer_read_prepare(iter->trace_buffer->buffer,
+				ring_buffer_read_prepare(iter->array_buffer->buffer,
 							 cpu, GFP_KERNEL);
 		}
 		ring_buffer_read_prepare_sync();
@@ -4231,7 +4253,7 @@ __tracing_open(struct inode *inode, struct file *file, bool snapshot)
 	} else {
 		cpu = iter->cpu_file;
 		iter->buffer_iter[cpu] =
-			ring_buffer_read_prepare(iter->trace_buffer->buffer,
+			ring_buffer_read_prepare(iter->array_buffer->buffer,
 						 cpu, GFP_KERNEL);
 		ring_buffer_read_prepare_sync();
 		ring_buffer_read_start(iter->buffer_iter[cpu]);
@@ -4357,7 +4379,7 @@ static int tracing_open(struct inode *inode, struct file *file)
 	/* If this file was open for write, then erase contents */
 	if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
 		int cpu = tracing_get_cpu(inode);
-		struct trace_buffer *trace_buf = &tr->trace_buffer;
+		struct array_buffer *trace_buf = &tr->array_buffer;
 
 #ifdef CONFIG_TRACER_MAX_TRACE
 		if (tr->current_trace->print_max)
@@ -4554,20 +4576,13 @@ out_err:
 	return count;
 }
 
-static ssize_t
-tracing_cpumask_write(struct file *filp, const char __user *ubuf,
-		      size_t count, loff_t *ppos)
+int tracing_set_cpumask(struct trace_array *tr,
+			cpumask_var_t tracing_cpumask_new)
 {
-	struct trace_array *tr = file_inode(filp)->i_private;
-	cpumask_var_t tracing_cpumask_new;
-	int err, cpu;
-
-	if (!alloc_cpumask_var(&tracing_cpumask_new, GFP_KERNEL))
-		return -ENOMEM;
+	int cpu;
 
-	err = cpumask_parse_user(ubuf, count, tracing_cpumask_new);
-	if (err)
-		goto err_unlock;
+	if (!tr)
+		return -EINVAL;
 
 	local_irq_disable();
 	arch_spin_lock(&tr->max_lock);
@@ -4578,24 +4593,47 @@ tracing_cpumask_write(struct file *filp, const char __user *ubuf,
 		 */
 		if (cpumask_test_cpu(cpu, tr->tracing_cpumask) &&
 				!cpumask_test_cpu(cpu, tracing_cpumask_new)) {
-			atomic_inc(&per_cpu_ptr(tr->trace_buffer.data, cpu)->disabled);
-			ring_buffer_record_disable_cpu(tr->trace_buffer.buffer, cpu);
+			atomic_inc(&per_cpu_ptr(tr->array_buffer.data, cpu)->disabled);
+			ring_buffer_record_disable_cpu(tr->array_buffer.buffer, cpu);
 		}
 		if (!cpumask_test_cpu(cpu, tr->tracing_cpumask) &&
 				cpumask_test_cpu(cpu, tracing_cpumask_new)) {
-			atomic_dec(&per_cpu_ptr(tr->trace_buffer.data, cpu)->disabled);
-			ring_buffer_record_enable_cpu(tr->trace_buffer.buffer, cpu);
+			atomic_dec(&per_cpu_ptr(tr->array_buffer.data, cpu)->disabled);
+			ring_buffer_record_enable_cpu(tr->array_buffer.buffer, cpu);
 		}
 	}
 	arch_spin_unlock(&tr->max_lock);
 	local_irq_enable();
 
 	cpumask_copy(tr->tracing_cpumask, tracing_cpumask_new);
+
+	return 0;
+}
+
+static ssize_t
+tracing_cpumask_write(struct file *filp, const char __user *ubuf,
+		      size_t count, loff_t *ppos)
+{
+	struct trace_array *tr = file_inode(filp)->i_private;
+	cpumask_var_t tracing_cpumask_new;
+	int err;
+
+	if (!alloc_cpumask_var(&tracing_cpumask_new, GFP_KERNEL))
+		return -ENOMEM;
+
+	err = cpumask_parse_user(ubuf, count, tracing_cpumask_new);
+	if (err)
+		goto err_free;
+
+	err = tracing_set_cpumask(tr, tracing_cpumask_new);
+	if (err)
+		goto err_free;
+
 	free_cpumask_var(tracing_cpumask_new);
 
 	return count;
 
-err_unlock:
+err_free:
 	free_cpumask_var(tracing_cpumask_new);
 
 	return err;
@@ -4726,7 +4764,7 @@ int set_tracer_flag(struct trace_array *tr, unsigned int mask, int enabled)
 		ftrace_pid_follow_fork(tr, enabled);
 
 	if (mask == TRACE_ITER_OVERWRITE) {
-		ring_buffer_change_overwrite(tr->trace_buffer.buffer, enabled);
+		ring_buffer_change_overwrite(tr->array_buffer.buffer, enabled);
 #ifdef CONFIG_TRACER_MAX_TRACE
 		ring_buffer_change_overwrite(tr->max_buffer.buffer, enabled);
 #endif
@@ -4740,7 +4778,7 @@ int set_tracer_flag(struct trace_array *tr, unsigned int mask, int enabled)
 	return 0;
 }
 
-static int trace_set_options(struct trace_array *tr, char *option)
+int trace_set_options(struct trace_array *tr, char *option)
 {
 	char *cmp;
 	int neg = 0;
@@ -5361,14 +5399,12 @@ static void *eval_map_next(struct seq_file *m, void *v, loff_t *pos)
 	 * Paranoid! If ptr points to end, we don't want to increment past it.
 	 * This really should never happen.
 	 */
+	(*pos)++;
 	ptr = update_eval_map(ptr);
 	if (WARN_ON_ONCE(!ptr))
 		return NULL;
 
 	ptr++;
-
-	(*pos)++;
-
 	ptr = update_eval_map(ptr);
 
 	return ptr;
@@ -5534,11 +5570,11 @@ tracing_set_trace_read(struct file *filp, char __user *ubuf,
 
 int tracer_init(struct tracer *t, struct trace_array *tr)
 {
-	tracing_reset_online_cpus(&tr->trace_buffer);
+	tracing_reset_online_cpus(&tr->array_buffer);
 	return t->init(tr);
 }
 
-static void set_buffer_entries(struct trace_buffer *buf, unsigned long val)
+static void set_buffer_entries(struct array_buffer *buf, unsigned long val)
 {
 	int cpu;
 
@@ -5548,8 +5584,8 @@ static void set_buffer_entries(struct trace_buffer *buf, unsigned long val)
 
 #ifdef CONFIG_TRACER_MAX_TRACE
 /* resize @tr's buffer to the size of @size_tr's entries */
-static int resize_buffer_duplicate_size(struct trace_buffer *trace_buf,
-					struct trace_buffer *size_buf, int cpu_id)
+static int resize_buffer_duplicate_size(struct array_buffer *trace_buf,
+					struct array_buffer *size_buf, int cpu_id)
 {
 	int cpu, ret = 0;
 
@@ -5587,10 +5623,10 @@ static int __tracing_resize_ring_buffer(struct trace_array *tr,
 	ring_buffer_expanded = true;
 
 	/* May be called before buffers are initialized */
-	if (!tr->trace_buffer.buffer)
+	if (!tr->array_buffer.buffer)
 		return 0;
 
-	ret = ring_buffer_resize(tr->trace_buffer.buffer, size, cpu);
+	ret = ring_buffer_resize(tr->array_buffer.buffer, size, cpu);
 	if (ret < 0)
 		return ret;
 
@@ -5601,8 +5637,8 @@ static int __tracing_resize_ring_buffer(struct trace_array *tr,
 
 	ret = ring_buffer_resize(tr->max_buffer.buffer, size, cpu);
 	if (ret < 0) {
-		int r = resize_buffer_duplicate_size(&tr->trace_buffer,
-						     &tr->trace_buffer, cpu);
+		int r = resize_buffer_duplicate_size(&tr->array_buffer,
+						     &tr->array_buffer, cpu);
 		if (r < 0) {
 			/*
 			 * AARGH! We are left with different
@@ -5633,15 +5669,15 @@ static int __tracing_resize_ring_buffer(struct trace_array *tr,
 #endif /* CONFIG_TRACER_MAX_TRACE */
 
 	if (cpu == RING_BUFFER_ALL_CPUS)
-		set_buffer_entries(&tr->trace_buffer, size);
+		set_buffer_entries(&tr->array_buffer, size);
 	else
-		per_cpu_ptr(tr->trace_buffer.data, cpu)->entries = size;
+		per_cpu_ptr(tr->array_buffer.data, cpu)->entries = size;
 
 	return ret;
 }
 
-static ssize_t tracing_resize_ring_buffer(struct trace_array *tr,
-					  unsigned long size, int cpu_id)
+ssize_t tracing_resize_ring_buffer(struct trace_array *tr,
+				  unsigned long size, int cpu_id)
 {
 	int ret = size;
 
@@ -5720,7 +5756,7 @@ static void add_tracer_options(struct trace_array *tr, struct tracer *t)
 	create_trace_option_files(tr, t);
 }
 
-static int tracing_set_tracer(struct trace_array *tr, const char *buf)
+int tracing_set_tracer(struct trace_array *tr, const char *buf)
 {
 	struct tracer *t;
 #ifdef CONFIG_TRACER_MAX_TRACE
@@ -5979,7 +6015,7 @@ static int tracing_open_pipe(struct inode *inode, struct file *filp)
 		iter->iter_flags |= TRACE_FILE_TIME_IN_NS;
 
 	iter->tr = tr;
-	iter->trace_buffer = &tr->trace_buffer;
+	iter->array_buffer = &tr->array_buffer;
 	iter->cpu_file = tracing_get_cpu(inode);
 	mutex_init(&iter->mutex);
 	filp->private_data = iter;
@@ -6039,7 +6075,7 @@ trace_poll(struct trace_iterator *iter, struct file *filp, poll_table *poll_tabl
 		 */
 		return EPOLLIN | EPOLLRDNORM;
 	else
-		return ring_buffer_poll_wait(iter->trace_buffer->buffer, iter->cpu_file,
+		return ring_buffer_poll_wait(iter->array_buffer->buffer, iter->cpu_file,
 					     filp, poll_table);
 }
 
@@ -6356,8 +6392,8 @@ tracing_entries_read(struct file *filp, char __user *ubuf,
 		for_each_tracing_cpu(cpu) {
 			/* fill in the size from first enabled cpu */
 			if (size == 0)
-				size = per_cpu_ptr(tr->trace_buffer.data, cpu)->entries;
-			if (size != per_cpu_ptr(tr->trace_buffer.data, cpu)->entries) {
+				size = per_cpu_ptr(tr->array_buffer.data, cpu)->entries;
+			if (size != per_cpu_ptr(tr->array_buffer.data, cpu)->entries) {
 				buf_size_same = 0;
 				break;
 			}
@@ -6373,7 +6409,7 @@ tracing_entries_read(struct file *filp, char __user *ubuf,
 		} else
 			r = sprintf(buf, "X\n");
 	} else
-		r = sprintf(buf, "%lu\n", per_cpu_ptr(tr->trace_buffer.data, cpu)->entries >> 10);
+		r = sprintf(buf, "%lu\n", per_cpu_ptr(tr->array_buffer.data, cpu)->entries >> 10);
 
 	mutex_unlock(&trace_types_lock);
 
@@ -6420,7 +6456,7 @@ tracing_total_entries_read(struct file *filp, char __user *ubuf,
 
 	mutex_lock(&trace_types_lock);
 	for_each_tracing_cpu(cpu) {
-		size += per_cpu_ptr(tr->trace_buffer.data, cpu)->entries >> 10;
+		size += per_cpu_ptr(tr->array_buffer.data, cpu)->entries >> 10;
 		if (!ring_buffer_expanded)
 			expanded_size += trace_buf_size >> 10;
 	}
@@ -6470,7 +6506,7 @@ tracing_mark_write(struct file *filp, const char __user *ubuf,
 	struct trace_array *tr = filp->private_data;
 	struct ring_buffer_event *event;
 	enum event_trigger_type tt = ETT_NONE;
-	struct ring_buffer *buffer;
+	struct trace_buffer *buffer;
 	struct print_entry *entry;
 	unsigned long irq_flags;
 	ssize_t written;
@@ -6499,7 +6535,7 @@ tracing_mark_write(struct file *filp, const char __user *ubuf,
 	if (cnt < FAULTED_SIZE)
 		size += FAULTED_SIZE - cnt;
 
-	buffer = tr->trace_buffer.buffer;
+	buffer = tr->array_buffer.buffer;
 	event = __trace_buffer_lock_reserve(buffer, TRACE_PRINT, size,
 					    irq_flags, preempt_count());
 	if (unlikely(!event))
@@ -6550,7 +6586,7 @@ tracing_mark_raw_write(struct file *filp, const char __user *ubuf,
 {
 	struct trace_array *tr = filp->private_data;
 	struct ring_buffer_event *event;
-	struct ring_buffer *buffer;
+	struct trace_buffer *buffer;
 	struct raw_data_entry *entry;
 	unsigned long irq_flags;
 	ssize_t written;
@@ -6579,7 +6615,7 @@ tracing_mark_raw_write(struct file *filp, const char __user *ubuf,
 	if (cnt < FAULT_SIZE_ID)
 		size += FAULT_SIZE_ID - cnt;
 
-	buffer = tr->trace_buffer.buffer;
+	buffer = tr->array_buffer.buffer;
 	event = __trace_buffer_lock_reserve(buffer, TRACE_RAW_DATA, size,
 					    irq_flags, preempt_count());
 	if (!event)
@@ -6634,13 +6670,13 @@ int tracing_set_clock(struct trace_array *tr, const char *clockstr)
 
 	tr->clock_id = i;
 
-	ring_buffer_set_clock(tr->trace_buffer.buffer, trace_clocks[i].func);
+	ring_buffer_set_clock(tr->array_buffer.buffer, trace_clocks[i].func);
 
 	/*
 	 * New clock may not be consistent with the previous clock.
 	 * Reset the buffer so that it doesn't have incomparable timestamps.
 	 */
-	tracing_reset_online_cpus(&tr->trace_buffer);
+	tracing_reset_online_cpus(&tr->array_buffer);
 
 #ifdef CONFIG_TRACER_MAX_TRACE
 	if (tr->max_buffer.buffer)
@@ -6703,7 +6739,7 @@ static int tracing_time_stamp_mode_show(struct seq_file *m, void *v)
 
 	mutex_lock(&trace_types_lock);
 
-	if (ring_buffer_time_stamp_abs(tr->trace_buffer.buffer))
+	if (ring_buffer_time_stamp_abs(tr->array_buffer.buffer))
 		seq_puts(m, "delta [absolute]\n");
 	else
 		seq_puts(m, "[delta] absolute\n");
@@ -6748,7 +6784,7 @@ int tracing_set_time_stamp_abs(struct trace_array *tr, bool abs)
 			goto out;
 	}
 
-	ring_buffer_set_time_stamp_abs(tr->trace_buffer.buffer, abs);
+	ring_buffer_set_time_stamp_abs(tr->array_buffer.buffer, abs);
 
 #ifdef CONFIG_TRACER_MAX_TRACE
 	if (tr->max_buffer.buffer)
@@ -6797,7 +6833,7 @@ static int tracing_snapshot_open(struct inode *inode, struct file *file)
 		ret = 0;
 
 		iter->tr = tr;
-		iter->trace_buffer = &tr->max_buffer;
+		iter->array_buffer = &tr->max_buffer;
 		iter->cpu_file = tracing_get_cpu(inode);
 		m->private = iter;
 		file->private_data = m;
@@ -6860,7 +6896,7 @@ tracing_snapshot_write(struct file *filp, const char __user *ubuf, size_t cnt,
 #endif
 		if (tr->allocated_snapshot)
 			ret = resize_buffer_duplicate_size(&tr->max_buffer,
-					&tr->trace_buffer, iter->cpu_file);
+					&tr->array_buffer, iter->cpu_file);
 		else
 			ret = tracing_alloc_snapshot_instance(tr);
 		if (ret < 0)
@@ -6935,7 +6971,7 @@ static int snapshot_raw_open(struct inode *inode, struct file *filp)
 	}
 
 	info->iter.snapshot = true;
-	info->iter.trace_buffer = &info->iter.tr->max_buffer;
+	info->iter.array_buffer = &info->iter.tr->max_buffer;
 
 	return ret;
 }
@@ -7310,7 +7346,7 @@ static int tracing_buffers_open(struct inode *inode, struct file *filp)
 	info->iter.tr		= tr;
 	info->iter.cpu_file	= tracing_get_cpu(inode);
 	info->iter.trace	= tr->current_trace;
-	info->iter.trace_buffer = &tr->trace_buffer;
+	info->iter.array_buffer = &tr->array_buffer;
 	info->spare		= NULL;
 	/* Force reading ring buffer for first read */
 	info->read		= (unsigned int)-1;
@@ -7355,7 +7391,7 @@ tracing_buffers_read(struct file *filp, char __user *ubuf,
 #endif
 
 	if (!info->spare) {
-		info->spare = ring_buffer_alloc_read_page(iter->trace_buffer->buffer,
+		info->spare = ring_buffer_alloc_read_page(iter->array_buffer->buffer,
 							  iter->cpu_file);
 		if (IS_ERR(info->spare)) {
 			ret = PTR_ERR(info->spare);
@@ -7373,7 +7409,7 @@ tracing_buffers_read(struct file *filp, char __user *ubuf,
 
  again:
 	trace_access_lock(iter->cpu_file);
-	ret = ring_buffer_read_page(iter->trace_buffer->buffer,
+	ret = ring_buffer_read_page(iter->array_buffer->buffer,
 				    &info->spare,
 				    count,
 				    iter->cpu_file, 0);
@@ -7423,7 +7459,7 @@ static int tracing_buffers_release(struct inode *inode, struct file *file)
 	__trace_array_put(iter->tr);
 
 	if (info->spare)
-		ring_buffer_free_read_page(iter->trace_buffer->buffer,
+		ring_buffer_free_read_page(iter->array_buffer->buffer,
 					   info->spare_cpu, info->spare);
 	kfree(info);
 
@@ -7433,7 +7469,7 @@ static int tracing_buffers_release(struct inode *inode, struct file *file)
 }
 
 struct buffer_ref {
-	struct ring_buffer	*buffer;
+	struct trace_buffer	*buffer;
 	void			*page;
 	int			cpu;
 	refcount_t		refcount;
@@ -7528,7 +7564,7 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos,
 
  again:
 	trace_access_lock(iter->cpu_file);
-	entries = ring_buffer_entries_cpu(iter->trace_buffer->buffer, iter->cpu_file);
+	entries = ring_buffer_entries_cpu(iter->array_buffer->buffer, iter->cpu_file);
 
 	for (i = 0; i < spd.nr_pages_max && len && entries; i++, len -= PAGE_SIZE) {
 		struct page *page;
@@ -7541,7 +7577,7 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos,
 		}
 
 		refcount_set(&ref->refcount, 1);
-		ref->buffer = iter->trace_buffer->buffer;
+		ref->buffer = iter->array_buffer->buffer;
 		ref->page = ring_buffer_alloc_read_page(ref->buffer, iter->cpu_file);
 		if (IS_ERR(ref->page)) {
 			ret = PTR_ERR(ref->page);
@@ -7569,7 +7605,7 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos,
 		spd.nr_pages++;
 		*ppos += PAGE_SIZE;
 
-		entries = ring_buffer_entries_cpu(iter->trace_buffer->buffer, iter->cpu_file);
+		entries = ring_buffer_entries_cpu(iter->array_buffer->buffer, iter->cpu_file);
 	}
 
 	trace_access_unlock(iter->cpu_file);
@@ -7613,7 +7649,7 @@ tracing_stats_read(struct file *filp, char __user *ubuf,
 {
 	struct inode *inode = file_inode(filp);
 	struct trace_array *tr = inode->i_private;
-	struct trace_buffer *trace_buf = &tr->trace_buffer;
+	struct array_buffer *trace_buf = &tr->array_buffer;
 	int cpu = tracing_get_cpu(inode);
 	struct trace_seq *s;
 	unsigned long cnt;
@@ -7894,7 +7930,7 @@ static struct dentry *tracing_dentry_percpu(struct trace_array *tr, int cpu)
 
 	tr->percpu_dir = tracefs_create_dir("per_cpu", d_tracer);
 
-	WARN_ONCE(!tr->percpu_dir,
+	MEM_FAIL(!tr->percpu_dir,
 		  "Could not create tracefs directory 'per_cpu/%d'\n", cpu);
 
 	return tr->percpu_dir;
@@ -8215,7 +8251,7 @@ create_trace_option_files(struct trace_array *tr, struct tracer *tracer)
 	for (cnt = 0; opts[cnt].name; cnt++) {
 		create_trace_option_file(tr, &topts[cnt], flags,
 					 &opts[cnt]);
-		WARN_ONCE(topts[cnt].entry == NULL,
+		MEM_FAIL(topts[cnt].entry == NULL,
 			  "Failed to create trace option: %s",
 			  opts[cnt].name);
 	}
@@ -8272,7 +8308,7 @@ rb_simple_write(struct file *filp, const char __user *ubuf,
 		size_t cnt, loff_t *ppos)
 {
 	struct trace_array *tr = filp->private_data;
-	struct ring_buffer *buffer = tr->trace_buffer.buffer;
+	struct trace_buffer *buffer = tr->array_buffer.buffer;
 	unsigned long val;
 	int ret;
 
@@ -8362,7 +8398,7 @@ static void
 init_tracer_tracefs(struct trace_array *tr, struct dentry *d_tracer);
 
 static int
-allocate_trace_buffer(struct trace_array *tr, struct trace_buffer *buf, int size)
+allocate_trace_buffer(struct trace_array *tr, struct array_buffer *buf, int size)
 {
 	enum ring_buffer_flags rb_flags;
 
@@ -8382,8 +8418,8 @@ allocate_trace_buffer(struct trace_array *tr, struct trace_buffer *buf, int size
 	}
 
 	/* Allocate the first page for all buffers */
-	set_buffer_entries(&tr->trace_buffer,
-			   ring_buffer_size(tr->trace_buffer.buffer, 0));
+	set_buffer_entries(&tr->array_buffer,
+			   ring_buffer_size(tr->array_buffer.buffer, 0));
 
 	return 0;
 }
@@ -8392,18 +8428,18 @@ static int allocate_trace_buffers(struct trace_array *tr, int size)
 {
 	int ret;
 
-	ret = allocate_trace_buffer(tr, &tr->trace_buffer, size);
+	ret = allocate_trace_buffer(tr, &tr->array_buffer, size);
 	if (ret)
 		return ret;
 
 #ifdef CONFIG_TRACER_MAX_TRACE
 	ret = allocate_trace_buffer(tr, &tr->max_buffer,
 				    allocate_snapshot ? size : 1);
-	if (WARN_ON(ret)) {
-		ring_buffer_free(tr->trace_buffer.buffer);
-		tr->trace_buffer.buffer = NULL;
-		free_percpu(tr->trace_buffer.data);
-		tr->trace_buffer.data = NULL;
+	if (MEM_FAIL(ret, "Failed to allocate trace buffer\n")) {
+		ring_buffer_free(tr->array_buffer.buffer);
+		tr->array_buffer.buffer = NULL;
+		free_percpu(tr->array_buffer.data);
+		tr->array_buffer.data = NULL;
 		return -ENOMEM;
 	}
 	tr->allocated_snapshot = allocate_snapshot;
@@ -8417,7 +8453,7 @@ static int allocate_trace_buffers(struct trace_array *tr, int size)
 	return 0;
 }
 
-static void free_trace_buffer(struct trace_buffer *buf)
+static void free_trace_buffer(struct array_buffer *buf)
 {
 	if (buf->buffer) {
 		ring_buffer_free(buf->buffer);
@@ -8432,7 +8468,7 @@ static void free_trace_buffers(struct trace_array *tr)
 	if (!tr)
 		return;
 
-	free_trace_buffer(&tr->trace_buffer);
+	free_trace_buffer(&tr->array_buffer);
 
 #ifdef CONFIG_TRACER_MAX_TRACE
 	free_trace_buffer(&tr->max_buffer);
@@ -8463,6 +8499,34 @@ static void update_tracer_options(struct trace_array *tr)
 	mutex_unlock(&trace_types_lock);
 }
 
+/* Must have trace_types_lock held */
+struct trace_array *trace_array_find(const char *instance)
+{
+	struct trace_array *tr, *found = NULL;
+
+	list_for_each_entry(tr, &ftrace_trace_arrays, list) {
+		if (tr->name && strcmp(tr->name, instance) == 0) {
+			found = tr;
+			break;
+		}
+	}
+
+	return found;
+}
+
+struct trace_array *trace_array_find_get(const char *instance)
+{
+	struct trace_array *tr;
+
+	mutex_lock(&trace_types_lock);
+	tr = trace_array_find(instance);
+	if (tr)
+		tr->ref++;
+	mutex_unlock(&trace_types_lock);
+
+	return tr;
+}
+
 static struct trace_array *trace_array_create(const char *name)
 {
 	struct trace_array *tr;
@@ -8539,10 +8603,8 @@ static int instance_mkdir(const char *name)
 	mutex_lock(&trace_types_lock);
 
 	ret = -EEXIST;
-	list_for_each_entry(tr, &ftrace_trace_arrays, list) {
-		if (tr->name && strcmp(tr->name, name) == 0)
-			goto out_unlock;
-	}
+	if (trace_array_find(name))
+		goto out_unlock;
 
 	tr = trace_array_create(name);
 
@@ -8564,6 +8626,10 @@ out_unlock:
  * NOTE: This function increments the reference counter associated with the
  * trace array returned. This makes sure it cannot be freed while in use.
  * Use trace_array_put() once the trace array is no longer needed.
+ * If the trace_array is to be freed, trace_array_destroy() needs to
+ * be called after the trace_array_put(), or simply let user space delete
+ * it from the tracefs instances directory. But until the
+ * trace_array_put() is called, user space can not delete it.
  *
  */
 struct trace_array *trace_array_get_by_name(const char *name)
@@ -8666,12 +8732,9 @@ static int instance_rmdir(const char *name)
 	mutex_lock(&trace_types_lock);
 
 	ret = -ENODEV;
-	list_for_each_entry(tr, &ftrace_trace_arrays, list) {
-		if (tr->name && strcmp(tr->name, name) == 0) {
-			ret = __remove_instance(tr);
-			break;
-		}
-	}
+	tr = trace_array_find(name);
+	if (tr)
+		ret = __remove_instance(tr);
 
 	mutex_unlock(&trace_types_lock);
 	mutex_unlock(&event_mutex);
@@ -8684,7 +8747,7 @@ static __init void create_trace_instances(struct dentry *d_tracer)
 	trace_instance_dir = tracefs_create_instance_dir("instances", d_tracer,
 							 instance_mkdir,
 							 instance_rmdir);
-	if (WARN_ON(!trace_instance_dir))
+	if (MEM_FAIL(!trace_instance_dir, "Failed to create instances directory\n"))
 		return;
 }
 
@@ -8754,7 +8817,7 @@ init_tracer_tracefs(struct trace_array *tr, struct dentry *d_tracer)
 #endif
 
 	if (ftrace_create_function_files(tr, d_tracer))
-		WARN(1, "Could not allocate function filter files");
+		MEM_FAIL(1, "Could not allocate function filter files");
 
 #ifdef CONFIG_TRACER_SNAPSHOT
 	trace_create_file("snapshot", 0644, d_tracer,
@@ -9036,13 +9099,13 @@ void trace_init_global_iter(struct trace_iterator *iter)
 	iter->tr = &global_trace;
 	iter->trace = iter->tr->current_trace;
 	iter->cpu_file = RING_BUFFER_ALL_CPUS;
-	iter->trace_buffer = &global_trace.trace_buffer;
+	iter->array_buffer = &global_trace.array_buffer;
 
 	if (iter->trace && iter->trace->open)
 		iter->trace->open(iter);
 
 	/* Annotate start of buffers if we had overruns */
-	if (ring_buffer_overruns(iter->trace_buffer->buffer))
+	if (ring_buffer_overruns(iter->array_buffer->buffer))
 		iter->iter_flags |= TRACE_FILE_ANNOTATE;
 
 	/* Output in nanoseconds only if we are using a clock in nanoseconds. */
@@ -9083,7 +9146,7 @@ void ftrace_dump(enum ftrace_dump_mode oops_dump_mode)
 	trace_init_global_iter(&iter);
 
 	for_each_tracing_cpu(cpu) {
-		atomic_inc(&per_cpu_ptr(iter.trace_buffer->data, cpu)->disabled);
+		atomic_inc(&per_cpu_ptr(iter.array_buffer->data, cpu)->disabled);
 	}
 
 	old_userobj = tr->trace_flags & TRACE_ITER_SYM_USEROBJ;
@@ -9151,7 +9214,7 @@ void ftrace_dump(enum ftrace_dump_mode oops_dump_mode)
 	tr->trace_flags |= old_userobj;
 
 	for_each_tracing_cpu(cpu) {
-		atomic_dec(&per_cpu_ptr(iter.trace_buffer->data, cpu)->disabled);
+		atomic_dec(&per_cpu_ptr(iter.array_buffer->data, cpu)->disabled);
 	}
 	atomic_dec(&dump_running);
 	printk_nmi_direct_exit();
@@ -9306,8 +9369,7 @@ __init static int tracer_alloc_buffers(void)
 
 	/* TODO: make the number of buffers hot pluggable with CPUS */
 	if (allocate_trace_buffers(&global_trace, ring_buf_size) < 0) {
-		printk(KERN_ERR "tracer: failed to allocate ring buffer!\n");
-		WARN_ON(1);
+		MEM_FAIL(1, "tracer: failed to allocate ring buffer!\n");
 		goto out_free_savedcmd;
 	}
 
@@ -9380,7 +9442,8 @@ void __init early_trace_init(void)
 	if (tracepoint_printk) {
 		tracepoint_print_iter =
 			kmalloc(sizeof(*tracepoint_print_iter), GFP_KERNEL);
-		if (WARN_ON(!tracepoint_print_iter))
+		if (MEM_FAIL(!tracepoint_print_iter,
+			     "Failed to allocate trace iterator\n"))
 			tracepoint_printk = 0;
 		else
 			static_key_enable(&tracepoint_printk_key.key);