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
  ...

33 files changed, 3277 insertions, 682 deletions

diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index 25a0fcfa7a5d..91e885194dbc 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -141,6 +141,15 @@ menuconfig FTRACE
 
 if FTRACE
 
+config BOOTTIME_TRACING
+	bool "Boot-time Tracing support"
+	depends on BOOT_CONFIG && TRACING
+	default y
+	help
+	  Enable developer to setup ftrace subsystem via supplemental
+	  kernel cmdline at boot time for debugging (tracing) driver
+	  initialization and boot process.
+
 config FUNCTION_TRACER
 	bool "Kernel Function Tracer"
 	depends on HAVE_FUNCTION_TRACER
@@ -172,6 +181,77 @@ config FUNCTION_GRAPH_TRACER
 	  the return value. This is done by setting the current return
 	  address on the current task structure into a stack of calls.
 
+config DYNAMIC_FTRACE
+	bool "enable/disable function tracing dynamically"
+	depends on FUNCTION_TRACER
+	depends on HAVE_DYNAMIC_FTRACE
+	default y
+	help
+	  This option will modify all the calls to function tracing
+	  dynamically (will patch them out of the binary image and
+	  replace them with a No-Op instruction) on boot up. During
+	  compile time, a table is made of all the locations that ftrace
+	  can function trace, and this table is linked into the kernel
+	  image. When this is enabled, functions can be individually
+	  enabled, and the functions not enabled will not affect
+	  performance of the system.
+
+	  See the files in /sys/kernel/debug/tracing:
+	    available_filter_functions
+	    set_ftrace_filter
+	    set_ftrace_notrace
+
+	  This way a CONFIG_FUNCTION_TRACER kernel is slightly larger, but
+	  otherwise has native performance as long as no tracing is active.
+
+config DYNAMIC_FTRACE_WITH_REGS
+	def_bool y
+	depends on DYNAMIC_FTRACE
+	depends on HAVE_DYNAMIC_FTRACE_WITH_REGS
+
+config DYNAMIC_FTRACE_WITH_DIRECT_CALLS
+	def_bool y
+	depends on DYNAMIC_FTRACE
+	depends on HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
+
+config FUNCTION_PROFILER
+	bool "Kernel function profiler"
+	depends on FUNCTION_TRACER
+	default n
+	help
+	  This option enables the kernel function profiler. A file is created
+	  in debugfs called function_profile_enabled which defaults to zero.
+	  When a 1 is echoed into this file profiling begins, and when a
+	  zero is entered, profiling stops. A "functions" file is created in
+	  the trace_stat directory; this file shows the list of functions that
+	  have been hit and their counters.
+
+	  If in doubt, say N.
+
+config STACK_TRACER
+	bool "Trace max stack"
+	depends on HAVE_FUNCTION_TRACER
+	select FUNCTION_TRACER
+	select STACKTRACE
+	select KALLSYMS
+	help
+	  This special tracer records the maximum stack footprint of the
+	  kernel and displays it in /sys/kernel/debug/tracing/stack_trace.
+
+	  This tracer works by hooking into every function call that the
+	  kernel executes, and keeping a maximum stack depth value and
+	  stack-trace saved.  If this is configured with DYNAMIC_FTRACE
+	  then it will not have any overhead while the stack tracer
+	  is disabled.
+
+	  To enable the stack tracer on bootup, pass in 'stacktrace'
+	  on the kernel command line.
+
+	  The stack tracer can also be enabled or disabled via the
+	  sysctl kernel.stack_tracer_enabled
+
+	  Say N if unsure.
+
 config TRACE_PREEMPT_TOGGLE
 	bool
 	help
@@ -282,6 +362,19 @@ config HWLAT_TRACER
 	 file. Every time a latency is greater than tracing_thresh, it will
 	 be recorded into the ring buffer.
 
+config MMIOTRACE
+	bool "Memory mapped IO tracing"
+	depends on HAVE_MMIOTRACE_SUPPORT && PCI
+	select GENERIC_TRACER
+	help
+	  Mmiotrace traces Memory Mapped I/O access and is meant for
+	  debugging and reverse engineering. It is called from the ioremap
+	  implementation and works via page faults. Tracing is disabled by
+	  default and can be enabled at run-time.
+
+	  See Documentation/trace/mmiotrace.rst.
+	  If you are not helping to develop drivers, say N.
+
 config ENABLE_DEFAULT_TRACERS
 	bool "Trace process context switches and events"
 	depends on !GENERIC_TRACER
@@ -410,30 +503,6 @@ config BRANCH_TRACER
 
 	  Say N if unsure.
 
-config STACK_TRACER
-	bool "Trace max stack"
-	depends on HAVE_FUNCTION_TRACER
-	select FUNCTION_TRACER
-	select STACKTRACE
-	select KALLSYMS
-	help
-	  This special tracer records the maximum stack footprint of the
-	  kernel and displays it in /sys/kernel/debug/tracing/stack_trace.
-
-	  This tracer works by hooking into every function call that the
-	  kernel executes, and keeping a maximum stack depth value and
-	  stack-trace saved.  If this is configured with DYNAMIC_FTRACE
-	  then it will not have any overhead while the stack tracer
-	  is disabled.
-
-	  To enable the stack tracer on bootup, pass in 'stacktrace'
-	  on the kernel command line.
-
-	  The stack tracer can also be enabled or disabled via the
-	  sysctl kernel.stack_tracer_enabled
-
-	  Say N if unsure.
-
 config BLK_DEV_IO_TRACE
 	bool "Support for tracing block IO actions"
 	depends on SYSFS
@@ -531,53 +600,6 @@ config DYNAMIC_EVENTS
 config PROBE_EVENTS
 	def_bool n
 
-config DYNAMIC_FTRACE
-	bool "enable/disable function tracing dynamically"
-	depends on FUNCTION_TRACER
-	depends on HAVE_DYNAMIC_FTRACE
-	default y
-	help
-	  This option will modify all the calls to function tracing
-	  dynamically (will patch them out of the binary image and
-	  replace them with a No-Op instruction) on boot up. During
-	  compile time, a table is made of all the locations that ftrace
-	  can function trace, and this table is linked into the kernel
-	  image. When this is enabled, functions can be individually
-	  enabled, and the functions not enabled will not affect
-	  performance of the system.
-
-	  See the files in /sys/kernel/debug/tracing:
-	    available_filter_functions
-	    set_ftrace_filter
-	    set_ftrace_notrace
-
-	  This way a CONFIG_FUNCTION_TRACER kernel is slightly larger, but
-	  otherwise has native performance as long as no tracing is active.
-
-config DYNAMIC_FTRACE_WITH_REGS
-	def_bool y
-	depends on DYNAMIC_FTRACE
-	depends on HAVE_DYNAMIC_FTRACE_WITH_REGS
-
-config DYNAMIC_FTRACE_WITH_DIRECT_CALLS
-	def_bool y
-	depends on DYNAMIC_FTRACE
-	depends on HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
-
-config FUNCTION_PROFILER
-	bool "Kernel function profiler"
-	depends on FUNCTION_TRACER
-	default n
-	help
-	  This option enables the kernel function profiler. A file is created
-	  in debugfs called function_profile_enabled which defaults to zero.
-	  When a 1 is echoed into this file profiling begins, and when a
-	  zero is entered, profiling stops. A "functions" file is created in
-	  the trace_stat directory; this file shows the list of functions that
-	  have been hit and their counters.
-
-	  If in doubt, say N.
-
 config BPF_KPROBE_OVERRIDE
 	bool "Enable BPF programs to override a kprobed function"
 	depends on BPF_EVENTS
@@ -592,54 +614,6 @@ config FTRACE_MCOUNT_RECORD
 	depends on DYNAMIC_FTRACE
 	depends on HAVE_FTRACE_MCOUNT_RECORD
 
-config FTRACE_SELFTEST
-	bool
-
-config FTRACE_STARTUP_TEST
-	bool "Perform a startup test on ftrace"
-	depends on GENERIC_TRACER
-	select FTRACE_SELFTEST
-	help
-	  This option performs a series of startup tests on ftrace. On bootup
-	  a series of tests are made to verify that the tracer is
-	  functioning properly. It will do tests on all the configured
-	  tracers of ftrace.
-
-config EVENT_TRACE_STARTUP_TEST
-	bool "Run selftest on trace events"
-	depends on FTRACE_STARTUP_TEST
-	default y
-	help
-	  This option performs a test on all trace events in the system.
-	  It basically just enables each event and runs some code that
-	  will trigger events (not necessarily the event it enables)
-	  This may take some time run as there are a lot of events.
-
-config EVENT_TRACE_TEST_SYSCALLS
-	bool "Run selftest on syscall events"
-	depends on EVENT_TRACE_STARTUP_TEST
-	help
-	 This option will also enable testing every syscall event.
-	 It only enables the event and disables it and runs various loads
-	 with the event enabled. This adds a bit more time for kernel boot
-	 up since it runs this on every system call defined.
-
-	 TBD - enable a way to actually call the syscalls as we test their
-	       events
-
-config MMIOTRACE
-	bool "Memory mapped IO tracing"
-	depends on HAVE_MMIOTRACE_SUPPORT && PCI
-	select GENERIC_TRACER
-	help
-	  Mmiotrace traces Memory Mapped I/O access and is meant for
-	  debugging and reverse engineering. It is called from the ioremap
-	  implementation and works via page faults. Tracing is disabled by
-	  default and can be enabled at run-time.
-
-	  See Documentation/trace/mmiotrace.rst.
-	  If you are not helping to develop drivers, say N.
-
 config TRACING_MAP
 	bool
 	depends on ARCH_HAVE_NMI_SAFE_CMPXCHG
@@ -680,16 +654,6 @@ config TRACE_EVENT_INJECT
 
 	  If unsure, say N.
 
-config MMIOTRACE_TEST
-	tristate "Test module for mmiotrace"
-	depends on MMIOTRACE && m
-	help
-	  This is a dumb module for testing mmiotrace. It is very dangerous
-	  as it will write garbage to IO memory starting at a given address.
-	  However, it should be safe to use on e.g. unused portion of VRAM.
-
-	  Say N, unless you absolutely know what you are doing.
-
 config TRACEPOINT_BENCHMARK
 	bool "Add tracepoint that benchmarks tracepoints"
 	help
@@ -736,6 +700,81 @@ config RING_BUFFER_BENCHMARK
 
 	  If unsure, say N.
 
+config TRACE_EVAL_MAP_FILE
+       bool "Show eval mappings for trace events"
+       depends on TRACING
+       help
+	The "print fmt" of the trace events will show the enum/sizeof names
+	instead of their values. This can cause problems for user space tools
+	that use this string to parse the raw data as user space does not know
+	how to convert the string to its value.
+
+	To fix this, there's a special macro in the kernel that can be used
+	to convert an enum/sizeof into its value. If this macro is used, then
+	the print fmt strings will be converted to their values.
+
+	If something does not get converted properly, this option can be
+	used to show what enums/sizeof the kernel tried to convert.
+
+	This option is for debugging the conversions. A file is created
+	in the tracing directory called "eval_map" that will show the
+	names matched with their values and what trace event system they
+	belong too.
+
+	Normally, the mapping of the strings to values will be freed after
+	boot up or module load. With this option, they will not be freed, as
+	they are needed for the "eval_map" file. Enabling this option will
+	increase the memory footprint of the running kernel.
+
+	If unsure, say N.
+
+config GCOV_PROFILE_FTRACE
+	bool "Enable GCOV profiling on ftrace subsystem"
+	depends on GCOV_KERNEL
+	help
+	  Enable GCOV profiling on ftrace subsystem for checking
+	  which functions/lines are tested.
+
+	  If unsure, say N.
+
+	  Note that on a kernel compiled with this config, ftrace will
+	  run significantly slower.
+
+config FTRACE_SELFTEST
+	bool
+
+config FTRACE_STARTUP_TEST
+	bool "Perform a startup test on ftrace"
+	depends on GENERIC_TRACER
+	select FTRACE_SELFTEST
+	help
+	  This option performs a series of startup tests on ftrace. On bootup
+	  a series of tests are made to verify that the tracer is
+	  functioning properly. It will do tests on all the configured
+	  tracers of ftrace.
+
+config EVENT_TRACE_STARTUP_TEST
+	bool "Run selftest on trace events"
+	depends on FTRACE_STARTUP_TEST
+	default y
+	help
+	  This option performs a test on all trace events in the system.
+	  It basically just enables each event and runs some code that
+	  will trigger events (not necessarily the event it enables)
+	  This may take some time run as there are a lot of events.
+
+config EVENT_TRACE_TEST_SYSCALLS
+	bool "Run selftest on syscall events"
+	depends on EVENT_TRACE_STARTUP_TEST
+	help
+	 This option will also enable testing every syscall event.
+	 It only enables the event and disables it and runs various loads
+	 with the event enabled. This adds a bit more time for kernel boot
+	 up since it runs this on every system call defined.
+
+	 TBD - enable a way to actually call the syscalls as we test their
+	       events
+
 config RING_BUFFER_STARTUP_TEST
        bool "Ring buffer startup self test"
        depends on RING_BUFFER
@@ -759,8 +798,18 @@ config RING_BUFFER_STARTUP_TEST
 
 	 If unsure, say N
 
+config MMIOTRACE_TEST
+	tristate "Test module for mmiotrace"
+	depends on MMIOTRACE && m
+	help
+	  This is a dumb module for testing mmiotrace. It is very dangerous
+	  as it will write garbage to IO memory starting at a given address.
+	  However, it should be safe to use on e.g. unused portion of VRAM.
+
+	  Say N, unless you absolutely know what you are doing.
+
 config PREEMPTIRQ_DELAY_TEST
-	tristate "Preempt / IRQ disable delay thread to test latency tracers"
+	tristate "Test module to create a preempt / IRQ disable delay thread to test latency tracers"
 	depends on m
 	help
 	  Select this option to build a test module that can help test latency
@@ -774,45 +823,30 @@ config PREEMPTIRQ_DELAY_TEST
 
 	  If unsure, say N
 
-config TRACE_EVAL_MAP_FILE
-       bool "Show eval mappings for trace events"
-       depends on TRACING
-       help
-	The "print fmt" of the trace events will show the enum/sizeof names
-	instead of their values. This can cause problems for user space tools
-	that use this string to parse the raw data as user space does not know
-	how to convert the string to its value.
-
-	To fix this, there's a special macro in the kernel that can be used
-	to convert an enum/sizeof into its value. If this macro is used, then
-	the print fmt strings will be converted to their values.
-
-	If something does not get converted properly, this option can be
-	used to show what enums/sizeof the kernel tried to convert.
-
-	This option is for debugging the conversions. A file is created
-	in the tracing directory called "eval_map" that will show the
-	names matched with their values and what trace event system they
-	belong too.
+config SYNTH_EVENT_GEN_TEST
+	tristate "Test module for in-kernel synthetic event generation"
+	depends on HIST_TRIGGERS
+	help
+          This option creates a test module to check the base
+          functionality of in-kernel synthetic event definition and
+          generation.
 
-	Normally, the mapping of the strings to values will be freed after
-	boot up or module load. With this option, they will not be freed, as
-	they are needed for the "eval_map" file. Enabling this option will
-	increase the memory footprint of the running kernel.
+          To test, insert the module, and then check the trace buffer
+	  for the generated sample events.
 
-	If unsure, say N.
+	  If unsure, say N.
 
-config GCOV_PROFILE_FTRACE
-	bool "Enable GCOV profiling on ftrace subsystem"
-	depends on GCOV_KERNEL
+config KPROBE_EVENT_GEN_TEST
+	tristate "Test module for in-kernel kprobe event generation"
+	depends on KPROBE_EVENTS
 	help
-	  Enable GCOV profiling on ftrace subsystem for checking
-	  which functions/lines are tested.
+          This option creates a test module to check the base
+          functionality of in-kernel kprobe event definition.
 
-	  If unsure, say N.
+          To test, insert the module, and then check the trace buffer
+	  for the generated kprobe events.
 
-	  Note that on a kernel compiled with this config, ftrace will
-	  run significantly slower.
+	  If unsure, say N.
 
 endif # FTRACE
 
diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile
index 0e63db62225f..f9dcd19165fa 100644
--- a/kernel/trace/Makefile
+++ b/kernel/trace/Makefile
@@ -44,6 +44,8 @@ obj-$(CONFIG_TRACING) += trace_stat.o
 obj-$(CONFIG_TRACING) += trace_printk.o
 obj-$(CONFIG_TRACING_MAP) += tracing_map.o
 obj-$(CONFIG_PREEMPTIRQ_DELAY_TEST) += preemptirq_delay_test.o
+obj-$(CONFIG_SYNTH_EVENT_GEN_TEST) += synth_event_gen_test.o
+obj-$(CONFIG_KPROBE_EVENT_GEN_TEST) += kprobe_event_gen_test.o
 obj-$(CONFIG_CONTEXT_SWITCH_TRACER) += trace_sched_switch.o
 obj-$(CONFIG_FUNCTION_TRACER) += trace_functions.o
 obj-$(CONFIG_PREEMPTIRQ_TRACEPOINTS) += trace_preemptirq.o
@@ -83,6 +85,7 @@ endif
 obj-$(CONFIG_DYNAMIC_EVENTS) += trace_dynevent.o
 obj-$(CONFIG_PROBE_EVENTS) += trace_probe.o
 obj-$(CONFIG_UPROBE_EVENTS) += trace_uprobe.o
+obj-$(CONFIG_BOOTTIME_TRACING) += trace_boot.o
 
 obj-$(CONFIG_TRACEPOINT_BENCHMARK) += trace_benchmark.o
 
diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index 475e29498bca..0735ae8545d8 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -68,14 +68,14 @@ static void trace_note(struct blk_trace *bt, pid_t pid, int action,
 {
 	struct blk_io_trace *t;
 	struct ring_buffer_event *event = NULL;
-	struct ring_buffer *buffer = NULL;
+	struct trace_buffer *buffer = NULL;
 	int pc = 0;
 	int cpu = smp_processor_id();
 	bool blk_tracer = blk_tracer_enabled;
 	ssize_t cgid_len = cgid ? sizeof(cgid) : 0;
 
 	if (blk_tracer) {
-		buffer = blk_tr->trace_buffer.buffer;
+		buffer = blk_tr->array_buffer.buffer;
 		pc = preempt_count();
 		event = trace_buffer_lock_reserve(buffer, TRACE_BLK,
 						  sizeof(*t) + len + cgid_len,
@@ -215,7 +215,7 @@ static void __blk_add_trace(struct blk_trace *bt, sector_t sector, int bytes,
 {
 	struct task_struct *tsk = current;
 	struct ring_buffer_event *event = NULL;
-	struct ring_buffer *buffer = NULL;
+	struct trace_buffer *buffer = NULL;
 	struct blk_io_trace *t;
 	unsigned long flags = 0;
 	unsigned long *sequence;
@@ -248,7 +248,7 @@ static void __blk_add_trace(struct blk_trace *bt, sector_t sector, int bytes,
 	if (blk_tracer) {
 		tracing_record_cmdline(current);
 
-		buffer = blk_tr->trace_buffer.buffer;
+		buffer = blk_tr->array_buffer.buffer;
 		pc = preempt_count();
 		event = trace_buffer_lock_reserve(buffer, TRACE_BLK,
 						  sizeof(*t) + pdu_len + cgid_len,
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 9bf1f2cd515e..3f7ee102868a 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -62,8 +62,6 @@
 	})
 
 /* hash bits for specific function selection */
-#define FTRACE_HASH_BITS 7
-#define FTRACE_FUNC_HASHSIZE (1 << FTRACE_HASH_BITS)
 #define FTRACE_HASH_DEFAULT_BITS 10
 #define FTRACE_HASH_MAX_BITS 12
 
@@ -146,7 +144,7 @@ static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip,
 {
 	struct trace_array *tr = op->private;
 
-	if (tr && this_cpu_read(tr->trace_buffer.data->ftrace_ignore_pid))
+	if (tr && this_cpu_read(tr->array_buffer.data->ftrace_ignore_pid))
 		return;
 
 	op->saved_func(ip, parent_ip, op, regs);
@@ -1103,9 +1101,6 @@ struct ftrace_page {
 #define ENTRY_SIZE sizeof(struct dyn_ftrace)
 #define ENTRIES_PER_PAGE (PAGE_SIZE / ENTRY_SIZE)
 
-/* estimate from running different kernels */
-#define NR_TO_INIT		10000
-
 static struct ftrace_page	*ftrace_pages_start;
 static struct ftrace_page	*ftrace_pages;
 
@@ -5464,7 +5459,7 @@ static void __init set_ftrace_early_graph(char *buf, int enable)
 	struct ftrace_hash *hash;
 
 	hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS);
-	if (WARN_ON(!hash))
+	if (MEM_FAIL(!hash, "Failed to allocate hash\n"))
 		return;
 
 	while (buf) {
@@ -5596,8 +5591,8 @@ static const struct file_operations ftrace_notrace_fops = {
 
 static DEFINE_MUTEX(graph_lock);
 
-struct ftrace_hash *ftrace_graph_hash = EMPTY_HASH;
-struct ftrace_hash *ftrace_graph_notrace_hash = EMPTY_HASH;
+struct ftrace_hash __rcu *ftrace_graph_hash = EMPTY_HASH;
+struct ftrace_hash __rcu *ftrace_graph_notrace_hash = EMPTY_HASH;
 
 enum graph_filter_type {
 	GRAPH_FILTER_NOTRACE	= 0,
@@ -5872,8 +5867,15 @@ ftrace_graph_release(struct inode *inode, struct file *file)
 
 		mutex_unlock(&graph_lock);
 
-		/* Wait till all users are no longer using the old hash */
-		synchronize_rcu();
+		/*
+		 * We need to do a hard force of sched synchronization.
+		 * This is because we use preempt_disable() to do RCU, but
+		 * the function tracers can be called where RCU is not watching
+		 * (like before user_exit()). We can not rely on the RCU
+		 * infrastructure to do the synchronization, thus we must do it
+		 * ourselves.
+		 */
+		schedule_on_each_cpu(ftrace_sync);
 
 		free_ftrace_hash(old_hash);
 	}
@@ -6596,7 +6598,7 @@ static void add_to_clear_hash_list(struct list_head *clear_list,
 
 	func = kmalloc(sizeof(*func), GFP_KERNEL);
 	if (!func) {
-		WARN_ONCE(1, "alloc failure, ftrace filter could be stale\n");
+		MEM_FAIL(1, "alloc failure, ftrace filter could be stale\n");
 		return;
 	}
 
@@ -6922,7 +6924,7 @@ ftrace_filter_pid_sched_switch_probe(void *data, bool preempt,
 
 	pid_list = rcu_dereference_sched(tr->function_pids);
 
-	this_cpu_write(tr->trace_buffer.data->ftrace_ignore_pid,
+	this_cpu_write(tr->array_buffer.data->ftrace_ignore_pid,
 		       trace_ignore_this_task(pid_list, next));
 }
 
@@ -6976,7 +6978,7 @@ static void clear_ftrace_pids(struct trace_array *tr)
 	unregister_trace_sched_switch(ftrace_filter_pid_sched_switch_probe, tr);
 
 	for_each_possible_cpu(cpu)
-		per_cpu_ptr(tr->trace_buffer.data, cpu)->ftrace_ignore_pid = false;
+		per_cpu_ptr(tr->array_buffer.data, cpu)->ftrace_ignore_pid = false;
 
 	rcu_assign_pointer(tr->function_pids, NULL);
 
@@ -7031,9 +7033,10 @@ static void *fpid_next(struct seq_file *m, void *v, loff_t *pos)
 	struct trace_array *tr = m->private;
 	struct trace_pid_list *pid_list = rcu_dereference_sched(tr->function_pids);
 
-	if (v == FTRACE_NO_PIDS)
+	if (v == FTRACE_NO_PIDS) {
+		(*pos)++;
 		return NULL;
-
+	}
 	return trace_pid_next(pid_list, v, pos);
 }
 
@@ -7100,7 +7103,7 @@ static void ignore_task_cpu(void *data)
 	pid_list = rcu_dereference_protected(tr->function_pids,
 					     mutex_is_locked(&ftrace_lock));
 
-	this_cpu_write(tr->trace_buffer.data->ftrace_ignore_pid,
+	this_cpu_write(tr->array_buffer.data->ftrace_ignore_pid,
 		       trace_ignore_this_task(pid_list, current));
 }
 
diff --git a/kernel/trace/kprobe_event_gen_test.c b/kernel/trace/kprobe_event_gen_test.c
new file mode 100644
index 000000000000..18b0f1cbb947
--- /dev/null
+++ b/kernel/trace/kprobe_event_gen_test.c
@@ -0,0 +1,225 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Test module for in-kernel kprobe event creation and generation.
+ *
+ * Copyright (C) 2019 Tom Zanussi <zanussi@kernel.org>
+ */
+
+#include <linux/module.h>
+#include <linux/trace_events.h>
+
+/*
+ * This module is a simple test of basic functionality for in-kernel
+ * kprobe/kretprobe event creation.  The first test uses
+ * kprobe_event_gen_cmd_start(), kprobe_event_add_fields() and
+ * kprobe_event_gen_cmd_end() to create a kprobe event, which is then
+ * enabled in order to generate trace output.  The second creates a
+ * kretprobe event using kretprobe_event_gen_cmd_start() and
+ * kretprobe_event_gen_cmd_end(), and is also then enabled.
+ *
+ * To test, select CONFIG_KPROBE_EVENT_GEN_TEST and build the module.
+ * Then:
+ *
+ * # insmod kernel/trace/kprobe_event_gen_test.ko
+ * # cat /sys/kernel/debug/tracing/trace
+ *
+ * You should see many instances of the "gen_kprobe_test" and
+ * "gen_kretprobe_test" events in the trace buffer.
+ *
+ * To remove the events, remove the module:
+ *
+ * # rmmod kprobe_event_gen_test
+ *
+ */
+
+static struct trace_event_file *gen_kprobe_test;
+static struct trace_event_file *gen_kretprobe_test;
+
+/*
+ * Test to make sure we can create a kprobe event, then add more
+ * fields.
+ */
+static int __init test_gen_kprobe_cmd(void)
+{
+	struct dynevent_cmd cmd;
+	char *buf;
+	int ret;
+
+	/* Create a buffer to hold the generated command */
+	buf = kzalloc(MAX_DYNEVENT_CMD_LEN, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	/* Before generating the command, initialize the cmd object */
+	kprobe_event_cmd_init(&cmd, buf, MAX_DYNEVENT_CMD_LEN);
+
+	/*
+	 * Define the gen_kprobe_test event with the first 2 kprobe
+	 * fields.
+	 */
+	ret = kprobe_event_gen_cmd_start(&cmd, "gen_kprobe_test",
+					 "do_sys_open",
+					 "dfd=%ax", "filename=%dx");
+	if (ret)
+		goto free;
+
+	/* Use kprobe_event_add_fields to add the rest of the fields */
+
+	ret = kprobe_event_add_fields(&cmd, "flags=%cx", "mode=+4($stack)");
+	if (ret)
+		goto free;
+
+	/*
+	 * This actually creates the event.
+	 */
+	ret = kprobe_event_gen_cmd_end(&cmd);
+	if (ret)
+		goto free;
+
+	/*
+	 * Now get the gen_kprobe_test event file.  We need to prevent
+	 * the instance and event from disappearing from underneath
+	 * us, which trace_get_event_file() does (though in this case
+	 * we're using the top-level instance which never goes away).
+	 */
+	gen_kprobe_test = trace_get_event_file(NULL, "kprobes",
+					       "gen_kprobe_test");
+	if (IS_ERR(gen_kprobe_test)) {
+		ret = PTR_ERR(gen_kprobe_test);
+		goto delete;
+	}
+
+	/* Enable the event or you won't see anything */
+	ret = trace_array_set_clr_event(gen_kprobe_test->tr,
+					"kprobes", "gen_kprobe_test", true);
+	if (ret) {
+		trace_put_event_file(gen_kprobe_test);
+		goto delete;
+	}
+ out:
+	return ret;
+ delete:
+	/* We got an error after creating the event, delete it */
+	ret = kprobe_event_delete("gen_kprobe_test");
+ free:
+	kfree(buf);
+
+	goto out;
+}
+
+/*
+ * Test to make sure we can create a kretprobe event.
+ */
+static int __init test_gen_kretprobe_cmd(void)
+{
+	struct dynevent_cmd cmd;
+	char *buf;
+	int ret;
+
+	/* Create a buffer to hold the generated command */
+	buf = kzalloc(MAX_DYNEVENT_CMD_LEN, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	/* Before generating the command, initialize the cmd object */
+	kprobe_event_cmd_init(&cmd, buf, MAX_DYNEVENT_CMD_LEN);
+
+	/*
+	 * Define the kretprobe event.
+	 */
+	ret = kretprobe_event_gen_cmd_start(&cmd, "gen_kretprobe_test",
+					    "do_sys_open",
+					    "$retval");
+	if (ret)
+		goto free;
+
+	/*
+	 * This actually creates the event.
+	 */
+	ret = kretprobe_event_gen_cmd_end(&cmd);
+	if (ret)
+		goto free;
+
+	/*
+	 * Now get the gen_kretprobe_test event file.  We need to
+	 * prevent the instance and event from disappearing from
+	 * underneath us, which trace_get_event_file() does (though in
+	 * this case we're using the top-level instance which never
+	 * goes away).
+	 */
+	gen_kretprobe_test = trace_get_event_file(NULL, "kprobes",
+						  "gen_kretprobe_test");
+	if (IS_ERR(gen_kretprobe_test)) {
+		ret = PTR_ERR(gen_kretprobe_test);
+		goto delete;
+	}
+
+	/* Enable the event or you won't see anything */
+	ret = trace_array_set_clr_event(gen_kretprobe_test->tr,
+					"kprobes", "gen_kretprobe_test", true);
+	if (ret) {
+		trace_put_event_file(gen_kretprobe_test);
+		goto delete;
+	}
+ out:
+	return ret;
+ delete:
+	/* We got an error after creating the event, delete it */
+	ret = kprobe_event_delete("gen_kretprobe_test");
+ free:
+	kfree(buf);
+
+	goto out;
+}
+
+static int __init kprobe_event_gen_test_init(void)
+{
+	int ret;
+
+	ret = test_gen_kprobe_cmd();
+	if (ret)
+		return ret;
+
+	ret = test_gen_kretprobe_cmd();
+	if (ret) {
+		WARN_ON(trace_array_set_clr_event(gen_kretprobe_test->tr,
+						  "kprobes",
+						  "gen_kretprobe_test", false));
+		trace_put_event_file(gen_kretprobe_test);
+		WARN_ON(kprobe_event_delete("gen_kretprobe_test"));
+	}
+
+	return ret;
+}
+
+static void __exit kprobe_event_gen_test_exit(void)
+{
+	/* Disable the event or you can't remove it */
+	WARN_ON(trace_array_set_clr_event(gen_kprobe_test->tr,
+					  "kprobes",
+					  "gen_kprobe_test", false));
+
+	/* Now give the file and instance back */
+	trace_put_event_file(gen_kprobe_test);
+
+	/* Now unregister and free the event */
+	WARN_ON(kprobe_event_delete("gen_kprobe_test"));
+
+	/* Disable the event or you can't remove it */
+	WARN_ON(trace_array_set_clr_event(gen_kprobe_test->tr,
+					  "kprobes",
+					  "gen_kretprobe_test", false));
+
+	/* Now give the file and instance back */
+	trace_put_event_file(gen_kretprobe_test);
+
+	/* Now unregister and free the event */
+	WARN_ON(kprobe_event_delete("gen_kretprobe_test"));
+}
+
+module_init(kprobe_event_gen_test_init)
+module_exit(kprobe_event_gen_test_exit)
+
+MODULE_AUTHOR("Tom Zanussi");
+MODULE_DESCRIPTION("kprobe event generation test");
+MODULE_LICENSE("GPL v2");
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 3f655371eaf6..61f0e92ace99 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -300,8 +300,6 @@ u64 ring_buffer_event_time_stamp(struct ring_buffer_event *event)
 /* Missed count stored at end */
 #define RB_MISSED_STORED	(1 << 30)
 
-#define RB_MISSED_FLAGS		(RB_MISSED_EVENTS|RB_MISSED_STORED)
-
 struct buffer_data_page {
 	u64		 time_stamp;	/* page time stamp */
 	local_t		 commit;	/* write committed index */
@@ -443,7 +441,7 @@ enum {
 struct ring_buffer_per_cpu {
 	int				cpu;
 	atomic_t			record_disabled;
-	struct ring_buffer		*buffer;
+	struct trace_buffer	*buffer;
 	raw_spinlock_t			reader_lock;	/* serialize readers */
 	arch_spinlock_t			lock;
 	struct lock_class_key		lock_key;
@@ -482,7 +480,7 @@ struct ring_buffer_per_cpu {
 	struct rb_irq_work		irq_work;
 };
 
-struct ring_buffer {
+struct trace_buffer {
 	unsigned			flags;
 	int				cpus;
 	atomic_t			record_disabled;
@@ -518,7 +516,7 @@ struct ring_buffer_iter {
  *
  * Returns the number of pages used by a per_cpu buffer of the ring buffer.
  */
-size_t ring_buffer_nr_pages(struct ring_buffer *buffer, int cpu)
+size_t ring_buffer_nr_pages(struct trace_buffer *buffer, int cpu)
 {
 	return buffer->buffers[cpu]->nr_pages;
 }
@@ -530,7 +528,7 @@ size_t ring_buffer_nr_pages(struct ring_buffer *buffer, int cpu)
  *
  * Returns the number of pages that have content in the ring buffer.
  */
-size_t ring_buffer_nr_dirty_pages(struct ring_buffer *buffer, int cpu)
+size_t ring_buffer_nr_dirty_pages(struct trace_buffer *buffer, int cpu)
 {
 	size_t read;
 	size_t cnt;
@@ -573,7 +571,7 @@ static void rb_wake_up_waiters(struct irq_work *work)
  * as data is added to any of the @buffer's cpu buffers. Otherwise
  * it will wait for data to be added to a specific cpu buffer.
  */
-int ring_buffer_wait(struct ring_buffer *buffer, int cpu, int full)
+int ring_buffer_wait(struct trace_buffer *buffer, int cpu, int full)
 {
 	struct ring_buffer_per_cpu *uninitialized_var(cpu_buffer);
 	DEFINE_WAIT(wait);
@@ -684,7 +682,7 @@ int ring_buffer_wait(struct ring_buffer *buffer, int cpu, int full)
  * Returns EPOLLIN | EPOLLRDNORM if data exists in the buffers,
  * zero otherwise.
  */
-__poll_t ring_buffer_poll_wait(struct ring_buffer *buffer, int cpu,
+__poll_t ring_buffer_poll_wait(struct trace_buffer *buffer, int cpu,
 			  struct file *filp, poll_table *poll_table)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
@@ -742,13 +740,13 @@ __poll_t ring_buffer_poll_wait(struct ring_buffer *buffer, int cpu,
 /* Up this if you want to test the TIME_EXTENTS and normalization */
 #define DEBUG_SHIFT 0
 
-static inline u64 rb_time_stamp(struct ring_buffer *buffer)
+static inline u64 rb_time_stamp(struct trace_buffer *buffer)
 {
 	/* shift to debug/test normalization and TIME_EXTENTS */
 	return buffer->clock() << DEBUG_SHIFT;
 }
 
-u64 ring_buffer_time_stamp(struct ring_buffer *buffer, int cpu)
+u64 ring_buffer_time_stamp(struct trace_buffer *buffer, int cpu)
 {
 	u64 time;
 
@@ -760,7 +758,7 @@ u64 ring_buffer_time_stamp(struct ring_buffer *buffer, int cpu)
 }
 EXPORT_SYMBOL_GPL(ring_buffer_time_stamp);
 
-void ring_buffer_normalize_time_stamp(struct ring_buffer *buffer,
+void ring_buffer_normalize_time_stamp(struct trace_buffer *buffer,
 				      int cpu, u64 *ts)
 {
 	/* Just stupid testing the normalize function and deltas */
@@ -1283,7 +1281,7 @@ static int rb_allocate_pages(struct ring_buffer_per_cpu *cpu_buffer,
 }
 
 static struct ring_buffer_per_cpu *
-rb_allocate_cpu_buffer(struct ring_buffer *buffer, long nr_pages, int cpu)
+rb_allocate_cpu_buffer(struct trace_buffer *buffer, long nr_pages, int cpu)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
 	struct buffer_page *bpage;
@@ -1368,16 +1366,17 @@ static void rb_free_cpu_buffer(struct ring_buffer_per_cpu *cpu_buffer)
  * __ring_buffer_alloc - allocate a new ring_buffer
  * @size: the size in bytes per cpu that is needed.
  * @flags: attributes to set for the ring buffer.
+ * @key: ring buffer reader_lock_key.
  *
  * Currently the only flag that is available is the RB_FL_OVERWRITE
  * flag. This flag means that the buffer will overwrite old data
  * when the buffer wraps. If this flag is not set, the buffer will
  * drop data when the tail hits the head.
  */
-struct ring_buffer *__ring_buffer_alloc(unsigned long size, unsigned flags,
+struct trace_buffer *__ring_buffer_alloc(unsigned long size, unsigned flags,
 					struct lock_class_key *key)
 {
-	struct ring_buffer *buffer;
+	struct trace_buffer *buffer;
 	long nr_pages;
 	int bsize;
 	int cpu;
@@ -1447,7 +1446,7 @@ EXPORT_SYMBOL_GPL(__ring_buffer_alloc);
  * @buffer: the buffer to free.
  */
 void
-ring_buffer_free(struct ring_buffer *buffer)
+ring_buffer_free(struct trace_buffer *buffer)
 {
 	int cpu;
 
@@ -1463,18 +1462,18 @@ ring_buffer_free(struct ring_buffer *buffer)
 }
 EXPORT_SYMBOL_GPL(ring_buffer_free);
 
-void ring_buffer_set_clock(struct ring_buffer *buffer,
+void ring_buffer_set_clock(struct trace_buffer *buffer,
 			   u64 (*clock)(void))
 {
 	buffer->clock = clock;
 }
 
-void ring_buffer_set_time_stamp_abs(struct ring_buffer *buffer, bool abs)
+void ring_buffer_set_time_stamp_abs(struct trace_buffer *buffer, bool abs)
 {
 	buffer->time_stamp_abs = abs;
 }
 
-bool ring_buffer_time_stamp_abs(struct ring_buffer *buffer)
+bool ring_buffer_time_stamp_abs(struct trace_buffer *buffer)
 {
 	return buffer->time_stamp_abs;
 }
@@ -1712,7 +1711,7 @@ static void update_pages_handler(struct work_struct *work)
  *
  * Returns 0 on success and < 0 on failure.
  */
-int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size,
+int ring_buffer_resize(struct trace_buffer *buffer, unsigned long size,
 			int cpu_id)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
@@ -1891,7 +1890,7 @@ int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size,
 }
 EXPORT_SYMBOL_GPL(ring_buffer_resize);
 
-void ring_buffer_change_overwrite(struct ring_buffer *buffer, int val)
+void ring_buffer_change_overwrite(struct trace_buffer *buffer, int val)
 {
 	mutex_lock(&buffer->mutex);
 	if (val)
@@ -2206,7 +2205,7 @@ rb_move_tail(struct ring_buffer_per_cpu *cpu_buffer,
 {
 	struct buffer_page *tail_page = info->tail_page;
 	struct buffer_page *commit_page = cpu_buffer->commit_page;
-	struct ring_buffer *buffer = cpu_buffer->buffer;
+	struct trace_buffer *buffer = cpu_buffer->buffer;
 	struct buffer_page *next_page;
 	int ret;
 
@@ -2330,11 +2329,11 @@ static inline bool rb_event_is_commit(struct ring_buffer_per_cpu *cpu_buffer,
 
 /**
  * rb_update_event - update event type and data
+ * @cpu_buffer: The per cpu buffer of the @event
  * @event: the event to update
- * @type: the type of event
- * @length: the size of the event field in the ring buffer
+ * @info: The info to update the @event with (contains length and delta)
  *
- * Update the type and data fields of the event. The length
+ * Update the type and data fields of the @event. The length
  * is the actual size that is written to the ring buffer,
  * and with this, we can determine what to place into the
  * data field.
@@ -2609,7 +2608,7 @@ static void rb_commit(struct ring_buffer_per_cpu *cpu_buffer,
 }
 
 static __always_inline void
-rb_wakeups(struct ring_buffer *buffer, struct ring_buffer_per_cpu *cpu_buffer)
+rb_wakeups(struct trace_buffer *buffer, struct ring_buffer_per_cpu *cpu_buffer)
 {
 	size_t nr_pages;
 	size_t dirty;
@@ -2733,7 +2732,7 @@ trace_recursive_unlock(struct ring_buffer_per_cpu *cpu_buffer)
  * Call this function before calling another ring_buffer_lock_reserve() and
  * call ring_buffer_nest_end() after the nested ring_buffer_unlock_commit().
  */
-void ring_buffer_nest_start(struct ring_buffer *buffer)
+void ring_buffer_nest_start(struct trace_buffer *buffer)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
 	int cpu;
@@ -2753,7 +2752,7 @@ void ring_buffer_nest_start(struct ring_buffer *buffer)
  * Must be called after ring_buffer_nest_start() and after the
  * ring_buffer_unlock_commit().
  */
-void ring_buffer_nest_end(struct ring_buffer *buffer)
+void ring_buffer_nest_end(struct trace_buffer *buffer)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
 	int cpu;
@@ -2775,7 +2774,7 @@ void ring_buffer_nest_end(struct ring_buffer *buffer)
  *
  * Must be paired with ring_buffer_lock_reserve.
  */
-int ring_buffer_unlock_commit(struct ring_buffer *buffer,
+int ring_buffer_unlock_commit(struct trace_buffer *buffer,
 			      struct ring_buffer_event *event)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
@@ -2868,7 +2867,7 @@ __rb_reserve_next(struct ring_buffer_per_cpu *cpu_buffer,
 }
 
 static __always_inline struct ring_buffer_event *
-rb_reserve_next_event(struct ring_buffer *buffer,
+rb_reserve_next_event(struct trace_buffer *buffer,
 		      struct ring_buffer_per_cpu *cpu_buffer,
 		      unsigned long length)
 {
@@ -2961,7 +2960,7 @@ rb_reserve_next_event(struct ring_buffer *buffer,
  * If NULL is returned, then nothing has been allocated or locked.
  */
 struct ring_buffer_event *
-ring_buffer_lock_reserve(struct ring_buffer *buffer, unsigned long length)
+ring_buffer_lock_reserve(struct trace_buffer *buffer, unsigned long length)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
 	struct ring_buffer_event *event;
@@ -3062,7 +3061,7 @@ rb_decrement_entry(struct ring_buffer_per_cpu *cpu_buffer,
  * If this function is called, do not call ring_buffer_unlock_commit on
  * the event.
  */
-void ring_buffer_discard_commit(struct ring_buffer *buffer,
+void ring_buffer_discard_commit(struct trace_buffer *buffer,
 				struct ring_buffer_event *event)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
@@ -3113,7 +3112,7 @@ EXPORT_SYMBOL_GPL(ring_buffer_discard_commit);
  * Note, like ring_buffer_lock_reserve, the length is the length of the data
  * and not the length of the event which would hold the header.
  */
-int ring_buffer_write(struct ring_buffer *buffer,
+int ring_buffer_write(struct trace_buffer *buffer,
 		      unsigned long length,
 		      void *data)
 {
@@ -3193,7 +3192,7 @@ static bool rb_per_cpu_empty(struct ring_buffer_per_cpu *cpu_buffer)
  *
  * The caller should call synchronize_rcu() after this.
  */
-void ring_buffer_record_disable(struct ring_buffer *buffer)
+void ring_buffer_record_disable(struct trace_buffer *buffer)
 {
 	atomic_inc(&buffer->record_disabled);
 }
@@ -3206,7 +3205,7 @@ EXPORT_SYMBOL_GPL(ring_buffer_record_disable);
  * Note, multiple disables will need the same number of enables
  * to truly enable the writing (much like preempt_disable).
  */
-void ring_buffer_record_enable(struct ring_buffer *buffer)
+void ring_buffer_record_enable(struct trace_buffer *buffer)
 {
 	atomic_dec(&buffer->record_disabled);
 }
@@ -3223,7 +3222,7 @@ EXPORT_SYMBOL_GPL(ring_buffer_record_enable);
  * it works like an on/off switch, where as the disable() version
  * must be paired with a enable().
  */
-void ring_buffer_record_off(struct ring_buffer *buffer)
+void ring_buffer_record_off(struct trace_buffer *buffer)
 {
 	unsigned int rd;
 	unsigned int new_rd;
@@ -3246,7 +3245,7 @@ EXPORT_SYMBOL_GPL(ring_buffer_record_off);
  * it works like an on/off switch, where as the enable() version
  * must be paired with a disable().
  */
-void ring_buffer_record_on(struct ring_buffer *buffer)
+void ring_buffer_record_on(struct trace_buffer *buffer)
 {
 	unsigned int rd;
 	unsigned int new_rd;
@@ -3264,7 +3263,7 @@ EXPORT_SYMBOL_GPL(ring_buffer_record_on);
  *
  * Returns true if the ring buffer is in a state that it accepts writes.
  */
-bool ring_buffer_record_is_on(struct ring_buffer *buffer)
+bool ring_buffer_record_is_on(struct trace_buffer *buffer)
 {
 	return !atomic_read(&buffer->record_disabled);
 }
@@ -3280,7 +3279,7 @@ bool ring_buffer_record_is_on(struct ring_buffer *buffer)
  * ring_buffer_record_disable(), as that is a temporary disabling of
  * the ring buffer.
  */
-bool ring_buffer_record_is_set_on(struct ring_buffer *buffer)
+bool ring_buffer_record_is_set_on(struct trace_buffer *buffer)
 {
 	return !(atomic_read(&buffer->record_disabled) & RB_BUFFER_OFF);
 }
@@ -3295,7 +3294,7 @@ bool ring_buffer_record_is_set_on(struct ring_buffer *buffer)
  *
  * The caller should call synchronize_rcu() after this.
  */
-void ring_buffer_record_disable_cpu(struct ring_buffer *buffer, int cpu)
+void ring_buffer_record_disable_cpu(struct trace_buffer *buffer, int cpu)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
 
@@ -3315,7 +3314,7 @@ EXPORT_SYMBOL_GPL(ring_buffer_record_disable_cpu);
  * Note, multiple disables will need the same number of enables
  * to truly enable the writing (much like preempt_disable).
  */
-void ring_buffer_record_enable_cpu(struct ring_buffer *buffer, int cpu)
+void ring_buffer_record_enable_cpu(struct trace_buffer *buffer, int cpu)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
 
@@ -3345,7 +3344,7 @@ rb_num_of_entries(struct ring_buffer_per_cpu *cpu_buffer)
  * @buffer: The ring buffer
  * @cpu: The per CPU buffer to read from.
  */
-u64 ring_buffer_oldest_event_ts(struct ring_buffer *buffer, int cpu)
+u64 ring_buffer_oldest_event_ts(struct trace_buffer *buffer, int cpu)
 {
 	unsigned long flags;
 	struct ring_buffer_per_cpu *cpu_buffer;
@@ -3378,7 +3377,7 @@ EXPORT_SYMBOL_GPL(ring_buffer_oldest_event_ts);
  * @buffer: The ring buffer
  * @cpu: The per CPU buffer to read from.
  */
-unsigned long ring_buffer_bytes_cpu(struct ring_buffer *buffer, int cpu)
+unsigned long ring_buffer_bytes_cpu(struct trace_buffer *buffer, int cpu)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
 	unsigned long ret;
@@ -3398,7 +3397,7 @@ EXPORT_SYMBOL_GPL(ring_buffer_bytes_cpu);
  * @buffer: The ring buffer
  * @cpu: The per CPU buffer to get the entries from.
  */
-unsigned long ring_buffer_entries_cpu(struct ring_buffer *buffer, int cpu)
+unsigned long ring_buffer_entries_cpu(struct trace_buffer *buffer, int cpu)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
 
@@ -3417,7 +3416,7 @@ EXPORT_SYMBOL_GPL(ring_buffer_entries_cpu);
  * @buffer: The ring buffer
  * @cpu: The per CPU buffer to get the number of overruns from
  */
-unsigned long ring_buffer_overrun_cpu(struct ring_buffer *buffer, int cpu)
+unsigned long ring_buffer_overrun_cpu(struct trace_buffer *buffer, int cpu)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
 	unsigned long ret;
@@ -3440,7 +3439,7 @@ EXPORT_SYMBOL_GPL(ring_buffer_overrun_cpu);
  * @cpu: The per CPU buffer to get the number of overruns from
  */
 unsigned long
-ring_buffer_commit_overrun_cpu(struct ring_buffer *buffer, int cpu)
+ring_buffer_commit_overrun_cpu(struct trace_buffer *buffer, int cpu)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
 	unsigned long ret;
@@ -3462,7 +3461,7 @@ EXPORT_SYMBOL_GPL(ring_buffer_commit_overrun_cpu);
  * @cpu: The per CPU buffer to get the number of overruns from
  */
 unsigned long
-ring_buffer_dropped_events_cpu(struct ring_buffer *buffer, int cpu)
+ring_buffer_dropped_events_cpu(struct trace_buffer *buffer, int cpu)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
 	unsigned long ret;
@@ -3483,7 +3482,7 @@ EXPORT_SYMBOL_GPL(ring_buffer_dropped_events_cpu);
  * @cpu: The per CPU buffer to get the number of events read
  */
 unsigned long
-ring_buffer_read_events_cpu(struct ring_buffer *buffer, int cpu)
+ring_buffer_read_events_cpu(struct trace_buffer *buffer, int cpu)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
 
@@ -3502,7 +3501,7 @@ EXPORT_SYMBOL_GPL(ring_buffer_read_events_cpu);
  * Returns the total number of entries in the ring buffer
  * (all CPU entries)
  */
-unsigned long ring_buffer_entries(struct ring_buffer *buffer)
+unsigned long ring_buffer_entries(struct trace_buffer *buffer)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
 	unsigned long entries = 0;
@@ -3525,7 +3524,7 @@ EXPORT_SYMBOL_GPL(ring_buffer_entries);
  * Returns the total number of overruns in the ring buffer
  * (all CPU entries)
  */
-unsigned long ring_buffer_overruns(struct ring_buffer *buffer)
+unsigned long ring_buffer_overruns(struct trace_buffer *buffer)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
 	unsigned long overruns = 0;
@@ -3949,7 +3948,7 @@ EXPORT_SYMBOL_GPL(ring_buffer_peek);
 static struct ring_buffer_event *
 rb_iter_peek(struct ring_buffer_iter *iter, u64 *ts)
 {
-	struct ring_buffer *buffer;
+	struct trace_buffer *buffer;
 	struct ring_buffer_per_cpu *cpu_buffer;
 	struct ring_buffer_event *event;
 	int nr_loops = 0;
@@ -4077,7 +4076,7 @@ rb_reader_unlock(struct ring_buffer_per_cpu *cpu_buffer, bool locked)
  * not consume the data.
  */
 struct ring_buffer_event *
-ring_buffer_peek(struct ring_buffer *buffer, int cpu, u64 *ts,
+ring_buffer_peek(struct trace_buffer *buffer, int cpu, u64 *ts,
 		 unsigned long *lost_events)
 {
 	struct ring_buffer_per_cpu *cpu_buffer = buffer->buffers[cpu];
@@ -4141,7 +4140,7 @@ ring_buffer_iter_peek(struct ring_buffer_iter *iter, u64 *ts)
  * and eventually empty the ring buffer if the producer is slower.
  */
 struct ring_buffer_event *
-ring_buffer_consume(struct ring_buffer *buffer, int cpu, u64 *ts,
+ring_buffer_consume(struct trace_buffer *buffer, int cpu, u64 *ts,
 		    unsigned long *lost_events)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
@@ -4201,7 +4200,7 @@ EXPORT_SYMBOL_GPL(ring_buffer_consume);
  * This overall must be paired with ring_buffer_read_finish.
  */
 struct ring_buffer_iter *
-ring_buffer_read_prepare(struct ring_buffer *buffer, int cpu, gfp_t flags)
+ring_buffer_read_prepare(struct trace_buffer *buffer, int cpu, gfp_t flags)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
 	struct ring_buffer_iter *iter;
@@ -4331,8 +4330,9 @@ EXPORT_SYMBOL_GPL(ring_buffer_read);
 /**
  * ring_buffer_size - return the size of the ring buffer (in bytes)
  * @buffer: The ring buffer.
+ * @cpu: The CPU to get ring buffer size from.
  */
-unsigned long ring_buffer_size(struct ring_buffer *buffer, int cpu)
+unsigned long ring_buffer_size(struct trace_buffer *buffer, int cpu)
 {
 	/*
 	 * Earlier, this method returned
@@ -4398,7 +4398,7 @@ rb_reset_cpu(struct ring_buffer_per_cpu *cpu_buffer)
  * @buffer: The ring buffer to reset a per cpu buffer of
  * @cpu: The CPU buffer to be reset
  */
-void ring_buffer_reset_cpu(struct ring_buffer *buffer, int cpu)
+void ring_buffer_reset_cpu(struct trace_buffer *buffer, int cpu)
 {
 	struct ring_buffer_per_cpu *cpu_buffer = buffer->buffers[cpu];
 	unsigned long flags;
@@ -4435,7 +4435,7 @@ EXPORT_SYMBOL_GPL(ring_buffer_reset_cpu);
  * ring_buffer_reset - reset a ring buffer
  * @buffer: The ring buffer to reset all cpu buffers
  */
-void ring_buffer_reset(struct ring_buffer *buffer)
+void ring_buffer_reset(struct trace_buffer *buffer)
 {
 	int cpu;
 
@@ -4448,7 +4448,7 @@ EXPORT_SYMBOL_GPL(ring_buffer_reset);
  * rind_buffer_empty - is the ring buffer empty?
  * @buffer: The ring buffer to test
  */
-bool ring_buffer_empty(struct ring_buffer *buffer)
+bool ring_buffer_empty(struct trace_buffer *buffer)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
 	unsigned long flags;
@@ -4478,7 +4478,7 @@ EXPORT_SYMBOL_GPL(ring_buffer_empty);
  * @buffer: The ring buffer
  * @cpu: The CPU buffer to test
  */
-bool ring_buffer_empty_cpu(struct ring_buffer *buffer, int cpu)
+bool ring_buffer_empty_cpu(struct trace_buffer *buffer, int cpu)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
 	unsigned long flags;
@@ -4504,14 +4504,15 @@ EXPORT_SYMBOL_GPL(ring_buffer_empty_cpu);
  * ring_buffer_swap_cpu - swap a CPU buffer between two ring buffers
  * @buffer_a: One buffer to swap with
  * @buffer_b: The other buffer to swap with
+ * @cpu: the CPU of the buffers to swap
  *
  * This function is useful for tracers that want to take a "snapshot"
  * of a CPU buffer and has another back up buffer lying around.
  * it is expected that the tracer handles the cpu buffer not being
  * used at the moment.
  */
-int ring_buffer_swap_cpu(struct ring_buffer *buffer_a,
-			 struct ring_buffer *buffer_b, int cpu)
+int ring_buffer_swap_cpu(struct trace_buffer *buffer_a,
+			 struct trace_buffer *buffer_b, int cpu)
 {
 	struct ring_buffer_per_cpu *cpu_buffer_a;
 	struct ring_buffer_per_cpu *cpu_buffer_b;
@@ -4590,7 +4591,7 @@ EXPORT_SYMBOL_GPL(ring_buffer_swap_cpu);
  * Returns:
  *  The page allocated, or ERR_PTR
  */
-void *ring_buffer_alloc_read_page(struct ring_buffer *buffer, int cpu)
+void *ring_buffer_alloc_read_page(struct trace_buffer *buffer, int cpu)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
 	struct buffer_data_page *bpage = NULL;
@@ -4637,7 +4638,7 @@ EXPORT_SYMBOL_GPL(ring_buffer_alloc_read_page);
  *
  * Free a page allocated from ring_buffer_alloc_read_page.
  */
-void ring_buffer_free_read_page(struct ring_buffer *buffer, int cpu, void *data)
+void ring_buffer_free_read_page(struct trace_buffer *buffer, int cpu, void *data)
 {
 	struct ring_buffer_per_cpu *cpu_buffer = buffer->buffers[cpu];
 	struct buffer_data_page *bpage = data;
@@ -4697,7 +4698,7 @@ EXPORT_SYMBOL_GPL(ring_buffer_free_read_page);
  *  >=0 if data has been transferred, returns the offset of consumed data.
  *  <0 if no data has been transferred.
  */
-int ring_buffer_read_page(struct ring_buffer *buffer,
+int ring_buffer_read_page(struct trace_buffer *buffer,
 			  void **data_page, size_t len, int cpu, int full)
 {
 	struct ring_buffer_per_cpu *cpu_buffer = buffer->buffers[cpu];
@@ -4868,12 +4869,12 @@ EXPORT_SYMBOL_GPL(ring_buffer_read_page);
  */
 int trace_rb_cpu_prepare(unsigned int cpu, struct hlist_node *node)
 {
-	struct ring_buffer *buffer;
+	struct trace_buffer *buffer;
 	long nr_pages_same;
 	int cpu_i;
 	unsigned long nr_pages;
 
-	buffer = container_of(node, struct ring_buffer, node);
+	buffer = container_of(node, struct trace_buffer, node);
 	if (cpumask_test_cpu(cpu, buffer->cpumask))
 		return 0;
 
@@ -4923,7 +4924,7 @@ int trace_rb_cpu_prepare(unsigned int cpu, struct hlist_node *node)
 static struct task_struct *rb_threads[NR_CPUS] __initdata;
 
 struct rb_test_data {
-	struct ring_buffer	*buffer;
+	struct trace_buffer *buffer;
 	unsigned long		events;
 	unsigned long		bytes_written;
 	unsigned long		bytes_alloc;
@@ -5065,7 +5066,7 @@ static __init int rb_hammer_test(void *arg)
 static __init int test_ringbuffer(void)
 {
 	struct task_struct *rb_hammer;
-	struct ring_buffer *buffer;
+	struct trace_buffer *buffer;
 	int cpu;
 	int ret = 0;
 
diff --git a/kernel/trace/ring_buffer_benchmark.c b/kernel/trace/ring_buffer_benchmark.c
index 32149e46551c..8df0aa810950 100644
--- a/kernel/trace/ring_buffer_benchmark.c
+++ b/kernel/trace/ring_buffer_benchmark.c
@@ -29,7 +29,7 @@ static int reader_finish;
 static DECLARE_COMPLETION(read_start);
 static DECLARE_COMPLETION(read_done);
 
-static struct ring_buffer *buffer;
+static struct trace_buffer *buffer;
 static struct task_struct *producer;
 static struct task_struct *consumer;
 static unsigned long read;
diff --git a/kernel/trace/synth_event_gen_test.c b/kernel/trace/synth_event_gen_test.c
new file mode 100644
index 000000000000..4aefe003cb7c
--- /dev/null
+++ b/kernel/trace/synth_event_gen_test.c
@@ -0,0 +1,523 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Test module for in-kernel sythetic event creation and generation.
+ *
+ * Copyright (C) 2019 Tom Zanussi <zanussi@kernel.org>
+ */
+
+#include <linux/module.h>
+#include <linux/trace_events.h>
+
+/*
+ * This module is a simple test of basic functionality for in-kernel
+ * synthetic event creation and generation, the first and second tests
+ * using synth_event_gen_cmd_start() and synth_event_add_field(), the
+ * third uses synth_event_create() to do it all at once with a static
+ * field array.
+ *
+ * Following that are a few examples using the created events to test
+ * various ways of tracing a synthetic event.
+ *
+ * To test, select CONFIG_SYNTH_EVENT_GEN_TEST and build the module.
+ * Then:
+ *
+ * # insmod kernel/trace/synth_event_gen_test.ko
+ * # cat /sys/kernel/debug/tracing/trace
+ *
+ * You should see several events in the trace buffer -
+ * "create_synth_test", "empty_synth_test", and several instances of
+ * "gen_synth_test".
+ *
+ * To remove the events, remove the module:
+ *
+ * # rmmod synth_event_gen_test
+ *
+ */
+
+static struct trace_event_file *create_synth_test;
+static struct trace_event_file *empty_synth_test;
+static struct trace_event_file *gen_synth_test;
+
+/*
+ * Test to make sure we can create a synthetic event, then add more
+ * fields.
+ */
+static int __init test_gen_synth_cmd(void)
+{
+	struct dynevent_cmd cmd;
+	u64 vals[7];
+	char *buf;
+	int ret;
+
+	/* Create a buffer to hold the generated command */
+	buf = kzalloc(MAX_DYNEVENT_CMD_LEN, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	/* Before generating the command, initialize the cmd object */
+	synth_event_cmd_init(&cmd, buf, MAX_DYNEVENT_CMD_LEN);
+
+	/*
+	 * Create the empty gen_synth_test synthetic event with the
+	 * first 4 fields.
+	 */
+	ret = synth_event_gen_cmd_start(&cmd, "gen_synth_test", THIS_MODULE,
+					"pid_t", "next_pid_field",
+					"char[16]", "next_comm_field",
+					"u64", "ts_ns",
+					"u64", "ts_ms");
+	if (ret)
+		goto free;
+
+	/* Use synth_event_add_field to add the rest of the fields */
+
+	ret = synth_event_add_field(&cmd, "unsigned int", "cpu");
+	if (ret)
+		goto free;
+
+	ret = synth_event_add_field(&cmd, "char[64]", "my_string_field");
+	if (ret)
+		goto free;
+
+	ret = synth_event_add_field(&cmd, "int", "my_int_field");
+	if (ret)
+		goto free;
+
+	ret = synth_event_gen_cmd_end(&cmd);
+	if (ret)
+		goto free;
+
+	/*
+	 * Now get the gen_synth_test event file.  We need to prevent
+	 * the instance and event from disappearing from underneath
+	 * us, which trace_get_event_file() does (though in this case
+	 * we're using the top-level instance which never goes away).
+	 */
+	gen_synth_test = trace_get_event_file(NULL, "synthetic",
+					      "gen_synth_test");
+	if (IS_ERR(gen_synth_test)) {
+		ret = PTR_ERR(gen_synth_test);
+		goto delete;
+	}
+
+	/* Enable the event or you won't see anything */
+	ret = trace_array_set_clr_event(gen_synth_test->tr,
+					"synthetic", "gen_synth_test", true);
+	if (ret) {
+		trace_put_event_file(gen_synth_test);
+		goto delete;
+	}
+
+	/* Create some bogus values just for testing */
+
+	vals[0] = 777;			/* next_pid_field */
+	vals[1] = (u64)"hula hoops";	/* next_comm_field */
+	vals[2] = 1000000;		/* ts_ns */
+	vals[3] = 1000;			/* ts_ms */
+	vals[4] = smp_processor_id();	/* cpu */
+	vals[5] = (u64)"thneed";	/* my_string_field */
+	vals[6] = 598;			/* my_int_field */
+
+	/* Now generate a gen_synth_test event */
+	ret = synth_event_trace_array(gen_synth_test, vals, ARRAY_SIZE(vals));
+ out:
+	return ret;
+ delete:
+	/* We got an error after creating the event, delete it */
+	synth_event_delete("gen_synth_test");
+ free:
+	kfree(buf);
+
+	goto out;
+}
+
+/*
+ * Test to make sure we can create an initially empty synthetic event,
+ * then add all the fields.
+ */
+static int __init test_empty_synth_event(void)
+{
+	struct dynevent_cmd cmd;
+	u64 vals[7];
+	char *buf;
+	int ret;
+
+	/* Create a buffer to hold the generated command */
+	buf = kzalloc(MAX_DYNEVENT_CMD_LEN, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	/* Before generating the command, initialize the cmd object */
+	synth_event_cmd_init(&cmd, buf, MAX_DYNEVENT_CMD_LEN);
+
+	/*
+	 * Create the empty_synth_test synthetic event with no fields.
+	 */
+	ret = synth_event_gen_cmd_start(&cmd, "empty_synth_test", THIS_MODULE);
+	if (ret)
+		goto free;
+
+	/* Use synth_event_add_field to add all of the fields */
+
+	ret = synth_event_add_field(&cmd, "pid_t", "next_pid_field");
+	if (ret)
+		goto free;
+
+	ret = synth_event_add_field(&cmd, "char[16]", "next_comm_field");
+	if (ret)
+		goto free;
+
+	ret = synth_event_add_field(&cmd, "u64", "ts_ns");
+	if (ret)
+		goto free;
+
+	ret = synth_event_add_field(&cmd, "u64", "ts_ms");
+	if (ret)
+		goto free;
+
+	ret = synth_event_add_field(&cmd, "unsigned int", "cpu");
+	if (ret)
+		goto free;
+
+	ret = synth_event_add_field(&cmd, "char[64]", "my_string_field");
+	if (ret)
+		goto free;
+
+	ret = synth_event_add_field(&cmd, "int", "my_int_field");
+	if (ret)
+		goto free;
+
+	/* All fields have been added, close and register the synth event */
+
+	ret = synth_event_gen_cmd_end(&cmd);
+	if (ret)
+		goto free;
+
+	/*
+	 * Now get the empty_synth_test event file.  We need to
+	 * prevent the instance and event from disappearing from
+	 * underneath us, which trace_get_event_file() does (though in
+	 * this case we're using the top-level instance which never
+	 * goes away).
+	 */
+	empty_synth_test = trace_get_event_file(NULL, "synthetic",
+						"empty_synth_test");
+	if (IS_ERR(empty_synth_test)) {
+		ret = PTR_ERR(empty_synth_test);
+		goto delete;
+	}
+
+	/* Enable the event or you won't see anything */
+	ret = trace_array_set_clr_event(empty_synth_test->tr,
+					"synthetic", "empty_synth_test", true);
+	if (ret) {
+		trace_put_event_file(empty_synth_test);
+		goto delete;
+	}
+
+	/* Create some bogus values just for testing */
+
+	vals[0] = 777;			/* next_pid_field */
+	vals[1] = (u64)"tiddlywinks";	/* next_comm_field */
+	vals[2] = 1000000;		/* ts_ns */
+	vals[3] = 1000;			/* ts_ms */
+	vals[4] = smp_processor_id();	/* cpu */
+	vals[5] = (u64)"thneed_2.0";	/* my_string_field */
+	vals[6] = 399;			/* my_int_field */
+
+	/* Now trace an empty_synth_test event */
+	ret = synth_event_trace_array(empty_synth_test, vals, ARRAY_SIZE(vals));
+ out:
+	return ret;
+ delete:
+	/* We got an error after creating the event, delete it */
+	synth_event_delete("empty_synth_test");
+ free:
+	kfree(buf);
+
+	goto out;
+}
+
+static struct synth_field_desc create_synth_test_fields[] = {
+	{ .type = "pid_t",		.name = "next_pid_field" },
+	{ .type = "char[16]",		.name = "next_comm_field" },
+	{ .type = "u64",		.name = "ts_ns" },
+	{ .type = "u64",		.name = "ts_ms" },
+	{ .type = "unsigned int",	.name = "cpu" },
+	{ .type = "char[64]",		.name = "my_string_field" },
+	{ .type = "int",		.name = "my_int_field" },
+};
+
+/*
+ * Test synthetic event creation all at once from array of field
+ * descriptors.
+ */
+static int __init test_create_synth_event(void)
+{
+	u64 vals[7];
+	int ret;
+
+	/* Create the create_synth_test event with the fields above */
+	ret = synth_event_create("create_synth_test",
+				 create_synth_test_fields,
+				 ARRAY_SIZE(create_synth_test_fields),
+				 THIS_MODULE);
+	if (ret)
+		goto out;
+
+	/*
+	 * Now get the create_synth_test event file.  We need to
+	 * prevent the instance and event from disappearing from
+	 * underneath us, which trace_get_event_file() does (though in
+	 * this case we're using the top-level instance which never
+	 * goes away).
+	 */
+	create_synth_test = trace_get_event_file(NULL, "synthetic",
+						 "create_synth_test");
+	if (IS_ERR(create_synth_test)) {
+		ret = PTR_ERR(create_synth_test);
+		goto delete;
+	}
+
+	/* Enable the event or you won't see anything */
+	ret = trace_array_set_clr_event(create_synth_test->tr,
+					"synthetic", "create_synth_test", true);
+	if (ret) {
+		trace_put_event_file(create_synth_test);
+		goto delete;
+	}
+
+	/* Create some bogus values just for testing */
+
+	vals[0] = 777;			/* next_pid_field */
+	vals[1] = (u64)"tiddlywinks";	/* next_comm_field */
+	vals[2] = 1000000;		/* ts_ns */
+	vals[3] = 1000;			/* ts_ms */
+	vals[4] = smp_processor_id();	/* cpu */
+	vals[5] = (u64)"thneed";	/* my_string_field */
+	vals[6] = 398;			/* my_int_field */
+
+	/* Now generate a create_synth_test event */
+	ret = synth_event_trace_array(create_synth_test, vals, ARRAY_SIZE(vals));
+ out:
+	return ret;
+ delete:
+	/* We got an error after creating the event, delete it */
+	ret = synth_event_delete("create_synth_test");
+
+	goto out;
+}
+
+/*
+ * Test tracing a synthetic event by reserving trace buffer space,
+ * then filling in fields one after another.
+ */
+static int __init test_add_next_synth_val(void)
+{
+	struct synth_event_trace_state trace_state;
+	int ret;
+
+	/* Start by reserving space in the trace buffer */
+	ret = synth_event_trace_start(gen_synth_test, &trace_state);
+	if (ret)
+		return ret;
+
+	/* Write some bogus values into the trace buffer, one after another */
+
+	/* next_pid_field */
+	ret = synth_event_add_next_val(777, &trace_state);
+	if (ret)
+		goto out;
+
+	/* next_comm_field */
+	ret = synth_event_add_next_val((u64)"slinky", &trace_state);
+	if (ret)
+		goto out;
+
+	/* ts_ns */
+	ret = synth_event_add_next_val(1000000, &trace_state);
+	if (ret)
+		goto out;
+
+	/* ts_ms */
+	ret = synth_event_add_next_val(1000, &trace_state);
+	if (ret)
+		goto out;
+
+	/* cpu */
+	ret = synth_event_add_next_val(smp_processor_id(), &trace_state);
+	if (ret)
+		goto out;
+
+	/* my_string_field */
+	ret = synth_event_add_next_val((u64)"thneed_2.01", &trace_state);
+	if (ret)
+		goto out;
+
+	/* my_int_field */
+	ret = synth_event_add_next_val(395, &trace_state);
+ out:
+	/* Finally, commit the event */
+	ret = synth_event_trace_end(&trace_state);
+
+	return ret;
+}
+
+/*
+ * Test tracing a synthetic event by reserving trace buffer space,
+ * then filling in fields using field names, which can be done in any
+ * order.
+ */
+static int __init test_add_synth_val(void)
+{
+	struct synth_event_trace_state trace_state;
+	int ret;
+
+	/* Start by reserving space in the trace buffer */
+	ret = synth_event_trace_start(gen_synth_test, &trace_state);
+	if (ret)
+		return ret;
+
+	/* Write some bogus values into the trace buffer, using field names */
+
+	ret = synth_event_add_val("ts_ns", 1000000, &trace_state);
+	if (ret)
+		goto out;
+
+	ret = synth_event_add_val("ts_ms", 1000, &trace_state);
+	if (ret)
+		goto out;
+
+	ret = synth_event_add_val("cpu", smp_processor_id(), &trace_state);
+	if (ret)
+		goto out;
+
+	ret = synth_event_add_val("next_pid_field", 777, &trace_state);
+	if (ret)
+		goto out;
+
+	ret = synth_event_add_val("next_comm_field", (u64)"silly putty",
+				  &trace_state);
+	if (ret)
+		goto out;
+
+	ret = synth_event_add_val("my_string_field", (u64)"thneed_9",
+				  &trace_state);
+	if (ret)
+		goto out;
+
+	ret = synth_event_add_val("my_int_field", 3999, &trace_state);
+ out:
+	/* Finally, commit the event */
+	ret = synth_event_trace_end(&trace_state);
+
+	return ret;
+}
+
+/*
+ * Test tracing a synthetic event all at once from array of values.
+ */
+static int __init test_trace_synth_event(void)
+{
+	int ret;
+
+	/* Trace some bogus values just for testing */
+	ret = synth_event_trace(create_synth_test, 7,	/* number of values */
+				444,			/* next_pid_field */
+				(u64)"clackers",	/* next_comm_field */
+				1000000,		/* ts_ns */
+				1000,			/* ts_ms */
+				smp_processor_id(),	/* cpu */
+				(u64)"Thneed",		/* my_string_field */
+				999);			/* my_int_field */
+	return ret;
+}
+
+static int __init synth_event_gen_test_init(void)
+{
+	int ret;
+
+	ret = test_gen_synth_cmd();
+	if (ret)
+		return ret;
+
+	ret = test_empty_synth_event();
+	if (ret) {
+		WARN_ON(trace_array_set_clr_event(gen_synth_test->tr,
+						  "synthetic",
+						  "gen_synth_test", false));
+		trace_put_event_file(gen_synth_test);
+		WARN_ON(synth_event_delete("gen_synth_test"));
+		goto out;
+	}
+
+	ret = test_create_synth_event();
+	if (ret) {
+		WARN_ON(trace_array_set_clr_event(gen_synth_test->tr,
+						  "synthetic",
+						  "gen_synth_test", false));
+		trace_put_event_file(gen_synth_test);
+		WARN_ON(synth_event_delete("gen_synth_test"));
+
+		WARN_ON(trace_array_set_clr_event(empty_synth_test->tr,
+						  "synthetic",
+						  "empty_synth_test", false));
+		trace_put_event_file(empty_synth_test);
+		WARN_ON(synth_event_delete("empty_synth_test"));
+		goto out;
+	}
+
+	ret = test_add_next_synth_val();
+	WARN_ON(ret);
+
+	ret = test_add_synth_val();
+	WARN_ON(ret);
+
+	ret = test_trace_synth_event();
+	WARN_ON(ret);
+ out:
+	return ret;
+}
+
+static void __exit synth_event_gen_test_exit(void)
+{
+	/* Disable the event or you can't remove it */
+	WARN_ON(trace_array_set_clr_event(gen_synth_test->tr,
+					  "synthetic",
+					  "gen_synth_test", false));
+
+	/* Now give the file and instance back */
+	trace_put_event_file(gen_synth_test);
+
+	/* Now unregister and free the synthetic event */
+	WARN_ON(synth_event_delete("gen_synth_test"));
+
+	/* Disable the event or you can't remove it */
+	WARN_ON(trace_array_set_clr_event(empty_synth_test->tr,
+					  "synthetic",
+					  "empty_synth_test", false));
+
+	/* Now give the file and instance back */
+	trace_put_event_file(empty_synth_test);
+
+	/* Now unregister and free the synthetic event */
+	WARN_ON(synth_event_delete("empty_synth_test"));
+
+	/* Disable the event or you can't remove it */
+	WARN_ON(trace_array_set_clr_event(create_synth_test->tr,
+					  "synthetic",
+					  "create_synth_test", false));
+
+	/* Now give the file and instance back */
+	trace_put_event_file(create_synth_test);
+
+	/* Now unregister and free the synthetic event */
+	WARN_ON(synth_event_delete("create_synth_test"));
+}
+
+module_init(synth_event_gen_test_init)
+module_exit(synth_event_gen_test_exit)
+
+MODULE_AUTHOR("Tom Zanussi");
+MODULE_DESCRIPTION("synthetic event generation test");
+MODULE_LICENSE("GPL v2");
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);
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index a98dce1b3334..99372dd7d168 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -93,6 +93,18 @@ enum trace_type {
 
 #include "trace_entries.h"
 
+/* Use this for memory failure errors */
+#define MEM_FAIL(condition, fmt, ...) ({			\
+	static bool __section(.data.once) __warned;		\
+	int __ret_warn_once = !!(condition);			\
+								\
+	if (unlikely(__ret_warn_once && !__warned)) {		\
+		__warned = true;				\
+		pr_err("ERROR: " fmt, ##__VA_ARGS__);		\
+	}							\
+	unlikely(__ret_warn_once);				\
+})
+
 /*
  * syscalls are special, and need special handling, this is why
  * they are not included in trace_entries.h
@@ -175,9 +187,9 @@ struct trace_array_cpu {
 struct tracer;
 struct trace_option_dentry;
 
-struct trace_buffer {
+struct array_buffer {
 	struct trace_array		*tr;
-	struct ring_buffer		*buffer;
+	struct trace_buffer		*buffer;
 	struct trace_array_cpu __percpu	*data;
 	u64				time_start;
 	int				cpu;
@@ -248,7 +260,7 @@ struct cond_snapshot {
 struct trace_array {
 	struct list_head	list;
 	char			*name;
-	struct trace_buffer	trace_buffer;
+	struct array_buffer	array_buffer;
 #ifdef CONFIG_TRACER_MAX_TRACE
 	/*
 	 * The max_buffer is used to snapshot the trace when a maximum
@@ -256,12 +268,12 @@ struct trace_array {
 	 * Some tracers will use this to store a maximum trace while
 	 * it continues examining live traces.
 	 *
-	 * The buffers for the max_buffer are set up the same as the trace_buffer
+	 * The buffers for the max_buffer are set up the same as the array_buffer
 	 * When a snapshot is taken, the buffer of the max_buffer is swapped
-	 * with the buffer of the trace_buffer and the buffers are reset for
-	 * the trace_buffer so the tracing can continue.
+	 * with the buffer of the array_buffer and the buffers are reset for
+	 * the array_buffer so the tracing can continue.
 	 */
-	struct trace_buffer	max_buffer;
+	struct array_buffer	max_buffer;
 	bool			allocated_snapshot;
 #endif
 #if defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER)
@@ -345,6 +357,8 @@ extern struct mutex trace_types_lock;
 
 extern int trace_array_get(struct trace_array *tr);
 extern int tracing_check_open_get_tr(struct trace_array *tr);
+extern struct trace_array *trace_array_find(const char *instance);
+extern struct trace_array *trace_array_find_get(const char *instance);
 
 extern int tracing_set_time_stamp_abs(struct trace_array *tr, bool abs);
 extern int tracing_set_clock(struct trace_array *tr, const char *clockstr);
@@ -684,7 +698,7 @@ trace_buffer_iter(struct trace_iterator *iter, int cpu)
 
 int tracer_init(struct tracer *t, struct trace_array *tr);
 int tracing_is_enabled(void);
-void tracing_reset_online_cpus(struct trace_buffer *buf);
+void tracing_reset_online_cpus(struct array_buffer *buf);
 void tracing_reset_current(int cpu);
 void tracing_reset_all_online_cpus(void);
 int tracing_open_generic(struct inode *inode, struct file *filp);
@@ -704,7 +718,7 @@ struct dentry *tracing_init_dentry(void);
 struct ring_buffer_event;
 
 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,
@@ -716,7 +730,7 @@ struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
 struct trace_entry *trace_find_next_entry(struct trace_iterator *iter,
 					  int *ent_cpu, u64 *ent_ts);
 
-void trace_buffer_unlock_commit_nostack(struct ring_buffer *buffer,
+void trace_buffer_unlock_commit_nostack(struct trace_buffer *buffer,
 					struct ring_buffer_event *event);
 
 int trace_empty(struct trace_iterator *iter);
@@ -872,7 +886,7 @@ trace_vprintk(unsigned long ip, const char *fmt, va_list args);
 extern int
 trace_array_vprintk(struct trace_array *tr,
 		    unsigned long ip, const char *fmt, va_list args);
-int trace_array_printk_buf(struct ring_buffer *buffer,
+int trace_array_printk_buf(struct trace_buffer *buffer,
 			   unsigned long ip, const char *fmt, ...);
 void trace_printk_seq(struct trace_seq *s);
 enum print_line_t print_trace_line(struct trace_iterator *iter);
@@ -949,22 +963,31 @@ extern void __trace_graph_return(struct trace_array *tr,
 				 unsigned long flags, int pc);
 
 #ifdef CONFIG_DYNAMIC_FTRACE
-extern struct ftrace_hash *ftrace_graph_hash;
-extern struct ftrace_hash *ftrace_graph_notrace_hash;
+extern struct ftrace_hash __rcu *ftrace_graph_hash;
+extern struct ftrace_hash __rcu *ftrace_graph_notrace_hash;
 
 static inline int ftrace_graph_addr(struct ftrace_graph_ent *trace)
 {
 	unsigned long addr = trace->func;
 	int ret = 0;
+	struct ftrace_hash *hash;
 
 	preempt_disable_notrace();
 
-	if (ftrace_hash_empty(ftrace_graph_hash)) {
+	/*
+	 * Have to open code "rcu_dereference_sched()" because the
+	 * function graph tracer can be called when RCU is not
+	 * "watching".
+	 * Protected with schedule_on_each_cpu(ftrace_sync)
+	 */
+	hash = rcu_dereference_protected(ftrace_graph_hash, !preemptible());
+
+	if (ftrace_hash_empty(hash)) {
 		ret = 1;
 		goto out;
 	}
 
-	if (ftrace_lookup_ip(ftrace_graph_hash, addr)) {
+	if (ftrace_lookup_ip(hash, addr)) {
 
 		/*
 		 * This needs to be cleared on the return functions
@@ -1000,10 +1023,20 @@ static inline void ftrace_graph_addr_finish(struct ftrace_graph_ret *trace)
 static inline int ftrace_graph_notrace_addr(unsigned long addr)
 {
 	int ret = 0;
+	struct ftrace_hash *notrace_hash;
 
 	preempt_disable_notrace();
 
-	if (ftrace_lookup_ip(ftrace_graph_notrace_hash, addr))
+	/*
+	 * Have to open code "rcu_dereference_sched()" because the
+	 * function graph tracer can be called when RCU is not
+	 * "watching".
+	 * Protected with schedule_on_each_cpu(ftrace_sync)
+	 */
+	notrace_hash = rcu_dereference_protected(ftrace_graph_notrace_hash,
+						 !preemptible());
+
+	if (ftrace_lookup_ip(notrace_hash, addr))
 		ret = 1;
 
 	preempt_enable_notrace();
@@ -1056,7 +1089,7 @@ struct ftrace_func_command {
 extern bool ftrace_filter_param __initdata;
 static inline int ftrace_trace_task(struct trace_array *tr)
 {
-	return !this_cpu_read(tr->trace_buffer.data->ftrace_ignore_pid);
+	return !this_cpu_read(tr->array_buffer.data->ftrace_ignore_pid);
 }
 extern int ftrace_is_dead(void);
 int ftrace_create_function_files(struct trace_array *tr,
@@ -1144,6 +1177,11 @@ int unregister_ftrace_command(struct ftrace_func_command *cmd);
 void ftrace_create_filter_files(struct ftrace_ops *ops,
 				struct dentry *parent);
 void ftrace_destroy_filter_files(struct ftrace_ops *ops);
+
+extern int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
+			     int len, int reset);
+extern int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
+			      int len, int reset);
 #else
 struct ftrace_func_command;
 
@@ -1366,17 +1404,17 @@ struct trace_subsystem_dir {
 };
 
 extern 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);
 
 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);
 
 static inline void trace_buffer_unlock_commit(struct trace_array *tr,
-					      struct ring_buffer *buffer,
+					      struct trace_buffer *buffer,
 					      struct ring_buffer_event *event,
 					      unsigned long flags, int pc)
 {
@@ -1389,7 +1427,7 @@ void trace_buffered_event_disable(void);
 void trace_buffered_event_enable(void);
 
 static inline void
-__trace_event_discard_commit(struct ring_buffer *buffer,
+__trace_event_discard_commit(struct trace_buffer *buffer,
 			     struct ring_buffer_event *event)
 {
 	if (this_cpu_read(trace_buffered_event) == event) {
@@ -1415,7 +1453,7 @@ __trace_event_discard_commit(struct ring_buffer *buffer,
  */
 static inline bool
 __event_trigger_test_discard(struct trace_event_file *file,
-			     struct ring_buffer *buffer,
+			     struct trace_buffer *buffer,
 			     struct ring_buffer_event *event,
 			     void *entry,
 			     enum event_trigger_type *tt)
@@ -1450,7 +1488,7 @@ __event_trigger_test_discard(struct trace_event_file *file,
  */
 static inline void
 event_trigger_unlock_commit(struct trace_event_file *file,
-			    struct ring_buffer *buffer,
+			    struct trace_buffer *buffer,
 			    struct ring_buffer_event *event,
 			    void *entry, unsigned long irq_flags, int pc)
 {
@@ -1481,7 +1519,7 @@ event_trigger_unlock_commit(struct trace_event_file *file,
  */
 static inline void
 event_trigger_unlock_commit_regs(struct trace_event_file *file,
-				 struct ring_buffer *buffer,
+				 struct trace_buffer *buffer,
 				 struct ring_buffer_event *event,
 				 void *entry, unsigned long irq_flags, int pc,
 				 struct pt_regs *regs)
@@ -1892,6 +1930,15 @@ void trace_printk_start_comm(void);
 int trace_keep_overwrite(struct tracer *tracer, u32 mask, int set);
 int set_tracer_flag(struct trace_array *tr, unsigned int mask, int enabled);
 
+/* Used from boot time tracer */
+extern int trace_set_options(struct trace_array *tr, char *option);
+extern int tracing_set_tracer(struct trace_array *tr, const char *buf);
+extern ssize_t tracing_resize_ring_buffer(struct trace_array *tr,
+					  unsigned long size, int cpu_id);
+extern int tracing_set_cpumask(struct trace_array *tr,
+				cpumask_var_t tracing_cpumask_new);
+
+
 #define MAX_EVENT_NAME_LEN	64
 
 extern int trace_run_command(const char *buf, int (*createfn)(int, char**));
@@ -1949,6 +1996,9 @@ static inline const char *get_syscall_name(int syscall)
 #ifdef CONFIG_EVENT_TRACING
 void trace_event_init(void);
 void trace_event_eval_update(struct trace_eval_map **map, int len);
+/* Used from boot time tracer */
+extern int ftrace_set_clr_event(struct trace_array *tr, char *buf, int set);
+extern int trigger_process_regex(struct trace_event_file *file, char *buff);
 #else
 static inline void __init trace_event_init(void) { }
 static inline void trace_event_eval_update(struct trace_eval_map **map, int len) { }
diff --git a/kernel/trace/trace_boot.c b/kernel/trace/trace_boot.c
new file mode 100644
index 000000000000..06d7feb5255f
--- /dev/null
+++ b/kernel/trace/trace_boot.c
@@ -0,0 +1,334 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * trace_boot.c
+ * Tracing kernel boot-time
+ */
+
+#define pr_fmt(fmt)	"trace_boot: " fmt
+
+#include <linux/bootconfig.h>
+#include <linux/cpumask.h>
+#include <linux/ftrace.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/mutex.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <linux/trace.h>
+#include <linux/trace_events.h>
+
+#include "trace.h"
+
+#define MAX_BUF_LEN 256
+
+static void __init
+trace_boot_set_instance_options(struct trace_array *tr, struct xbc_node *node)
+{
+	struct xbc_node *anode;
+	const char *p;
+	char buf[MAX_BUF_LEN];
+	unsigned long v = 0;
+
+	/* Common ftrace options */
+	xbc_node_for_each_array_value(node, "options", anode, p) {
+		if (strlcpy(buf, p, ARRAY_SIZE(buf)) >= ARRAY_SIZE(buf)) {
+			pr_err("String is too long: %s\n", p);
+			continue;
+		}
+
+		if (trace_set_options(tr, buf) < 0)
+			pr_err("Failed to set option: %s\n", buf);
+	}
+
+	p = xbc_node_find_value(node, "trace_clock", NULL);
+	if (p && *p != '\0') {
+		if (tracing_set_clock(tr, p) < 0)
+			pr_err("Failed to set trace clock: %s\n", p);
+	}
+
+	p = xbc_node_find_value(node, "buffer_size", NULL);
+	if (p && *p != '\0') {
+		v = memparse(p, NULL);
+		if (v < PAGE_SIZE)
+			pr_err("Buffer size is too small: %s\n", p);
+		if (tracing_resize_ring_buffer(tr, v, RING_BUFFER_ALL_CPUS) < 0)
+			pr_err("Failed to resize trace buffer to %s\n", p);
+	}
+
+	p = xbc_node_find_value(node, "cpumask", NULL);
+	if (p && *p != '\0') {
+		cpumask_var_t new_mask;
+
+		if (alloc_cpumask_var(&new_mask, GFP_KERNEL)) {
+			if (cpumask_parse(p, new_mask) < 0 ||
+			    tracing_set_cpumask(tr, new_mask) < 0)
+				pr_err("Failed to set new CPU mask %s\n", p);
+			free_cpumask_var(new_mask);
+		}
+	}
+}
+
+#ifdef CONFIG_EVENT_TRACING
+static void __init
+trace_boot_enable_events(struct trace_array *tr, struct xbc_node *node)
+{
+	struct xbc_node *anode;
+	char buf[MAX_BUF_LEN];
+	const char *p;
+
+	xbc_node_for_each_array_value(node, "events", anode, p) {
+		if (strlcpy(buf, p, ARRAY_SIZE(buf)) >= ARRAY_SIZE(buf)) {
+			pr_err("String is too long: %s\n", p);
+			continue;
+		}
+
+		if (ftrace_set_clr_event(tr, buf, 1) < 0)
+			pr_err("Failed to enable event: %s\n", p);
+	}
+}
+
+#ifdef CONFIG_KPROBE_EVENTS
+static int __init
+trace_boot_add_kprobe_event(struct xbc_node *node, const char *event)
+{
+	struct dynevent_cmd cmd;
+	struct xbc_node *anode;
+	char buf[MAX_BUF_LEN];
+	const char *val;
+	int ret;
+
+	kprobe_event_cmd_init(&cmd, buf, MAX_BUF_LEN);
+
+	ret = kprobe_event_gen_cmd_start(&cmd, event, NULL);
+	if (ret)
+		return ret;
+
+	xbc_node_for_each_array_value(node, "probes", anode, val) {
+		ret = kprobe_event_add_field(&cmd, val);
+		if (ret)
+			return ret;
+	}
+
+	ret = kprobe_event_gen_cmd_end(&cmd);
+	if (ret)
+		pr_err("Failed to add probe: %s\n", buf);
+
+	return ret;
+}
+#else
+static inline int __init
+trace_boot_add_kprobe_event(struct xbc_node *node, const char *event)
+{
+	pr_err("Kprobe event is not supported.\n");
+	return -ENOTSUPP;
+}
+#endif
+
+#ifdef CONFIG_HIST_TRIGGERS
+static int __init
+trace_boot_add_synth_event(struct xbc_node *node, const char *event)
+{
+	struct dynevent_cmd cmd;
+	struct xbc_node *anode;
+	char buf[MAX_BUF_LEN];
+	const char *p;
+	int ret;
+
+	synth_event_cmd_init(&cmd, buf, MAX_BUF_LEN);
+
+	ret = synth_event_gen_cmd_start(&cmd, event, NULL);
+	if (ret)
+		return ret;
+
+	xbc_node_for_each_array_value(node, "fields", anode, p) {
+		ret = synth_event_add_field_str(&cmd, p);
+		if (ret)
+			return ret;
+	}
+
+	ret = synth_event_gen_cmd_end(&cmd);
+	if (ret < 0)
+		pr_err("Failed to add synthetic event: %s\n", buf);
+
+	return ret;
+}
+#else
+static inline int __init
+trace_boot_add_synth_event(struct xbc_node *node, const char *event)
+{
+	pr_err("Synthetic event is not supported.\n");
+	return -ENOTSUPP;
+}
+#endif
+
+static void __init
+trace_boot_init_one_event(struct trace_array *tr, struct xbc_node *gnode,
+			  struct xbc_node *enode)
+{
+	struct trace_event_file *file;
+	struct xbc_node *anode;
+	char buf[MAX_BUF_LEN];
+	const char *p, *group, *event;
+
+	group = xbc_node_get_data(gnode);
+	event = xbc_node_get_data(enode);
+
+	if (!strcmp(group, "kprobes"))
+		if (trace_boot_add_kprobe_event(enode, event) < 0)
+			return;
+	if (!strcmp(group, "synthetic"))
+		if (trace_boot_add_synth_event(enode, event) < 0)
+			return;
+
+	mutex_lock(&event_mutex);
+	file = find_event_file(tr, group, event);
+	if (!file) {
+		pr_err("Failed to find event: %s:%s\n", group, event);
+		goto out;
+	}
+
+	p = xbc_node_find_value(enode, "filter", NULL);
+	if (p && *p != '\0') {
+		if (strlcpy(buf, p, ARRAY_SIZE(buf)) >= ARRAY_SIZE(buf))
+			pr_err("filter string is too long: %s\n", p);
+		else if (apply_event_filter(file, buf) < 0)
+			pr_err("Failed to apply filter: %s\n", buf);
+	}
+
+	xbc_node_for_each_array_value(enode, "actions", anode, p) {
+		if (strlcpy(buf, p, ARRAY_SIZE(buf)) >= ARRAY_SIZE(buf))
+			pr_err("action string is too long: %s\n", p);
+		else if (trigger_process_regex(file, buf) < 0)
+			pr_err("Failed to apply an action: %s\n", buf);
+	}
+
+	if (xbc_node_find_value(enode, "enable", NULL)) {
+		if (trace_event_enable_disable(file, 1, 0) < 0)
+			pr_err("Failed to enable event node: %s:%s\n",
+				group, event);
+	}
+out:
+	mutex_unlock(&event_mutex);
+}
+
+static void __init
+trace_boot_init_events(struct trace_array *tr, struct xbc_node *node)
+{
+	struct xbc_node *gnode, *enode;
+
+	node = xbc_node_find_child(node, "event");
+	if (!node)
+		return;
+	/* per-event key starts with "event.GROUP.EVENT" */
+	xbc_node_for_each_child(node, gnode)
+		xbc_node_for_each_child(gnode, enode)
+			trace_boot_init_one_event(tr, gnode, enode);
+}
+#else
+#define trace_boot_enable_events(tr, node) do {} while (0)
+#define trace_boot_init_events(tr, node) do {} while (0)
+#endif
+
+#ifdef CONFIG_DYNAMIC_FTRACE
+static void __init
+trace_boot_set_ftrace_filter(struct trace_array *tr, struct xbc_node *node)
+{
+	struct xbc_node *anode;
+	const char *p;
+	char *q;
+
+	xbc_node_for_each_array_value(node, "ftrace.filters", anode, p) {
+		q = kstrdup(p, GFP_KERNEL);
+		if (!q)
+			return;
+		if (ftrace_set_filter(tr->ops, q, strlen(q), 0) < 0)
+			pr_err("Failed to add %s to ftrace filter\n", p);
+		else
+			ftrace_filter_param = true;
+		kfree(q);
+	}
+	xbc_node_for_each_array_value(node, "ftrace.notraces", anode, p) {
+		q = kstrdup(p, GFP_KERNEL);
+		if (!q)
+			return;
+		if (ftrace_set_notrace(tr->ops, q, strlen(q), 0) < 0)
+			pr_err("Failed to add %s to ftrace filter\n", p);
+		else
+			ftrace_filter_param = true;
+		kfree(q);
+	}
+}
+#else
+#define trace_boot_set_ftrace_filter(tr, node) do {} while (0)
+#endif
+
+static void __init
+trace_boot_enable_tracer(struct trace_array *tr, struct xbc_node *node)
+{
+	const char *p;
+
+	trace_boot_set_ftrace_filter(tr, node);
+
+	p = xbc_node_find_value(node, "tracer", NULL);
+	if (p && *p != '\0') {
+		if (tracing_set_tracer(tr, p) < 0)
+			pr_err("Failed to set given tracer: %s\n", p);
+	}
+}
+
+static void __init
+trace_boot_init_one_instance(struct trace_array *tr, struct xbc_node *node)
+{
+	trace_boot_set_instance_options(tr, node);
+	trace_boot_init_events(tr, node);
+	trace_boot_enable_events(tr, node);
+	trace_boot_enable_tracer(tr, node);
+}
+
+static void __init
+trace_boot_init_instances(struct xbc_node *node)
+{
+	struct xbc_node *inode;
+	struct trace_array *tr;
+	const char *p;
+
+	node = xbc_node_find_child(node, "instance");
+	if (!node)
+		return;
+
+	xbc_node_for_each_child(node, inode) {
+		p = xbc_node_get_data(inode);
+		if (!p || *p == '\0')
+			continue;
+
+		tr = trace_array_get_by_name(p);
+		if (!tr) {
+			pr_err("Failed to get trace instance %s\n", p);
+			continue;
+		}
+		trace_boot_init_one_instance(tr, inode);
+		trace_array_put(tr);
+	}
+}
+
+static int __init trace_boot_init(void)
+{
+	struct xbc_node *trace_node;
+	struct trace_array *tr;
+
+	trace_node = xbc_find_node("ftrace");
+	if (!trace_node)
+		return 0;
+
+	tr = top_trace_array();
+	if (!tr)
+		return 0;
+
+	/* Global trace array is also one instance */
+	trace_boot_init_one_instance(tr, trace_node);
+	trace_boot_init_instances(trace_node);
+
+	return 0;
+}
+
+fs_initcall(trace_boot_init);
diff --git a/kernel/trace/trace_branch.c b/kernel/trace/trace_branch.c
index 88e158d27965..eff099123aa2 100644
--- a/kernel/trace/trace_branch.c
+++ b/kernel/trace/trace_branch.c
@@ -32,10 +32,10 @@ probe_likely_condition(struct ftrace_likely_data *f, int val, int expect)
 {
 	struct trace_event_call *call = &event_branch;
 	struct trace_array *tr = branch_tracer;
+	struct trace_buffer *buffer;
 	struct trace_array_cpu *data;
 	struct ring_buffer_event *event;
 	struct trace_branch *entry;
-	struct ring_buffer *buffer;
 	unsigned long flags;
 	int pc;
 	const char *p;
@@ -55,12 +55,12 @@ probe_likely_condition(struct ftrace_likely_data *f, int val, int expect)
 
 	raw_local_irq_save(flags);
 	current->trace_recursion |= TRACE_BRANCH_BIT;
-	data = this_cpu_ptr(tr->trace_buffer.data);
+	data = this_cpu_ptr(tr->array_buffer.data);
 	if (atomic_read(&data->disabled))
 		goto out;
 
 	pc = preempt_count();
-	buffer = tr->trace_buffer.buffer;
+	buffer = tr->array_buffer.buffer;
 	event = trace_buffer_lock_reserve(buffer, TRACE_BRANCH,
 					  sizeof(*entry), flags, pc);
 	if (!event)
diff --git a/kernel/trace/trace_dynevent.c b/kernel/trace/trace_dynevent.c
index 89779eb84a07..9f2e8520b748 100644
--- a/kernel/trace/trace_dynevent.c
+++ b/kernel/trace/trace_dynevent.c
@@ -223,3 +223,215 @@ static __init int init_dynamic_event(void)
 	return 0;
 }
 fs_initcall(init_dynamic_event);
+
+/**
+ * dynevent_arg_add - Add an arg to a dynevent_cmd
+ * @cmd: A pointer to the dynevent_cmd struct representing the new event cmd
+ * @arg: The argument to append to the current cmd
+ * @check_arg: An (optional) pointer to a function checking arg sanity
+ *
+ * Append an argument to a dynevent_cmd.  The argument string will be
+ * appended to the current cmd string, followed by a separator, if
+ * applicable.  Before the argument is added, the @check_arg function,
+ * if present, will be used to check the sanity of the current arg
+ * string.
+ *
+ * The cmd string and separator should be set using the
+ * dynevent_arg_init() before any arguments are added using this
+ * function.
+ *
+ * Return: 0 if successful, error otherwise.
+ */
+int dynevent_arg_add(struct dynevent_cmd *cmd,
+		     struct dynevent_arg *arg,
+		     dynevent_check_arg_fn_t check_arg)
+{
+	int ret = 0;
+
+	if (check_arg) {
+		ret = check_arg(arg);
+		if (ret)
+			return ret;
+	}
+
+	ret = seq_buf_printf(&cmd->seq, " %s%c", arg->str, arg->separator);
+	if (ret) {
+		pr_err("String is too long: %s%c\n", arg->str, arg->separator);
+		return -E2BIG;
+	}
+
+	return ret;
+}
+
+/**
+ * dynevent_arg_pair_add - Add an arg pair to a dynevent_cmd
+ * @cmd: A pointer to the dynevent_cmd struct representing the new event cmd
+ * @arg_pair: The argument pair to append to the current cmd
+ * @check_arg: An (optional) pointer to a function checking arg sanity
+ *
+ * Append an argument pair to a dynevent_cmd.  An argument pair
+ * consists of a left-hand-side argument and a right-hand-side
+ * argument separated by an operator, which can be whitespace, all
+ * followed by a separator, if applicable.  This can be used to add
+ * arguments of the form 'type variable_name;' or 'x+y'.
+ *
+ * The lhs argument string will be appended to the current cmd string,
+ * followed by an operator, if applicable, followd by the rhs string,
+ * followed finally by a separator, if applicable.  Before the
+ * argument is added, the @check_arg function, if present, will be
+ * used to check the sanity of the current arg strings.
+ *
+ * The cmd strings, operator, and separator should be set using the
+ * dynevent_arg_pair_init() before any arguments are added using this
+ * function.
+ *
+ * Return: 0 if successful, error otherwise.
+ */
+int dynevent_arg_pair_add(struct dynevent_cmd *cmd,
+			  struct dynevent_arg_pair *arg_pair,
+			  dynevent_check_arg_fn_t check_arg)
+{
+	int ret = 0;
+
+	if (check_arg) {
+		ret = check_arg(arg_pair);
+		if (ret)
+			return ret;
+	}
+
+	ret = seq_buf_printf(&cmd->seq, " %s%c%s%c", arg_pair->lhs,
+			     arg_pair->operator, arg_pair->rhs,
+			     arg_pair->separator);
+	if (ret) {
+		pr_err("field string is too long: %s%c%s%c\n", arg_pair->lhs,
+		       arg_pair->operator, arg_pair->rhs,
+		       arg_pair->separator);
+		return -E2BIG;
+	}
+
+	return ret;
+}
+
+/**
+ * dynevent_str_add - Add a string to a dynevent_cmd
+ * @cmd: A pointer to the dynevent_cmd struct representing the new event cmd
+ * @str: The string to append to the current cmd
+ *
+ * Append a string to a dynevent_cmd.  The string will be appended to
+ * the current cmd string as-is, with nothing prepended or appended.
+ *
+ * Return: 0 if successful, error otherwise.
+ */
+int dynevent_str_add(struct dynevent_cmd *cmd, const char *str)
+{
+	int ret = 0;
+
+	ret = seq_buf_puts(&cmd->seq, str);
+	if (ret) {
+		pr_err("String is too long: %s\n", str);
+		return -E2BIG;
+	}
+
+	return ret;
+}
+
+/**
+ * dynevent_cmd_init - Initialize a dynevent_cmd object
+ * @cmd: A pointer to the dynevent_cmd struct representing the cmd
+ * @buf: A pointer to the buffer to generate the command into
+ * @maxlen: The length of the buffer the command will be generated into
+ * @type: The type of the cmd, checked against further operations
+ * @run_command: The type-specific function that will actually run the command
+ *
+ * Initialize a dynevent_cmd.  A dynevent_cmd is used to build up and
+ * run dynamic event creation commands, such as commands for creating
+ * synthetic and kprobe events.  Before calling any of the functions
+ * used to build the command, a dynevent_cmd object should be
+ * instantiated and initialized using this function.
+ *
+ * The initialization sets things up by saving a pointer to the
+ * user-supplied buffer and its length via the @buf and @maxlen
+ * params, and by saving the cmd-specific @type and @run_command
+ * params which are used to check subsequent dynevent_cmd operations
+ * and actually run the command when complete.
+ */
+void dynevent_cmd_init(struct dynevent_cmd *cmd, char *buf, int maxlen,
+		       enum dynevent_type type,
+		       dynevent_create_fn_t run_command)
+{
+	memset(cmd, '\0', sizeof(*cmd));
+
+	seq_buf_init(&cmd->seq, buf, maxlen);
+	cmd->type = type;
+	cmd->run_command = run_command;
+}
+
+/**
+ * dynevent_arg_init - Initialize a dynevent_arg object
+ * @arg: A pointer to the dynevent_arg struct representing the arg
+ * @separator: An (optional) separator, appended after adding the arg
+ *
+ * Initialize a dynevent_arg object.  A dynevent_arg represents an
+ * object used to append single arguments to the current command
+ * string.  After the arg string is successfully appended to the
+ * command string, the optional @separator is appended.  If no
+ * separator was specified when initializing the arg, a space will be
+ * appended.
+ */
+void dynevent_arg_init(struct dynevent_arg *arg,
+		       char separator)
+{
+	memset(arg, '\0', sizeof(*arg));
+
+	if (!separator)
+		separator = ' ';
+	arg->separator = separator;
+}
+
+/**
+ * dynevent_arg_pair_init - Initialize a dynevent_arg_pair object
+ * @arg_pair: A pointer to the dynevent_arg_pair struct representing the arg
+ * @operator: An (optional) operator, appended after adding the first arg
+ * @separator: An (optional) separator, appended after adding the second arg
+ *
+ * Initialize a dynevent_arg_pair object.  A dynevent_arg_pair
+ * represents an object used to append argument pairs such as 'type
+ * variable_name;' or 'x+y' to the current command string.  An
+ * argument pair consists of a left-hand-side argument and a
+ * right-hand-side argument separated by an operator, which can be
+ * whitespace, all followed by a separator, if applicable.  After the
+ * first arg string is successfully appended to the command string,
+ * the optional @operator is appended, followed by the second arg and
+ * and optional @separator.  If no separator was specified when
+ * initializing the arg, a space will be appended.
+ */
+void dynevent_arg_pair_init(struct dynevent_arg_pair *arg_pair,
+			    char operator, char separator)
+{
+	memset(arg_pair, '\0', sizeof(*arg_pair));
+
+	if (!operator)
+		operator = ' ';
+	arg_pair->operator = operator;
+
+	if (!separator)
+		separator = ' ';
+	arg_pair->separator = separator;
+}
+
+/**
+ * dynevent_create - Create the dynamic event contained in dynevent_cmd
+ * @cmd: The dynevent_cmd object containing the dynamic event creation command
+ *
+ * Once a dynevent_cmd object has been successfully built up via the
+ * dynevent_cmd_init(), dynevent_arg_add() and dynevent_arg_pair_add()
+ * functions, this function runs the final command to actually create
+ * the event.
+ *
+ * Return: 0 if the event was successfully created, error otherwise.
+ */
+int dynevent_create(struct dynevent_cmd *cmd)
+{
+	return cmd->run_command(cmd);
+}
+EXPORT_SYMBOL_GPL(dynevent_create);
diff --git a/kernel/trace/trace_dynevent.h b/kernel/trace/trace_dynevent.h
index 46898138d2df..d6857a254ede 100644
--- a/kernel/trace/trace_dynevent.h
+++ b/kernel/trace/trace_dynevent.h
@@ -117,4 +117,36 @@ int dyn_event_release(int argc, char **argv, struct dyn_event_operations *type);
 #define for_each_dyn_event_safe(pos, n)	\
 	list_for_each_entry_safe(pos, n, &dyn_event_list, list)
 
+extern void dynevent_cmd_init(struct dynevent_cmd *cmd, char *buf, int maxlen,
+			      enum dynevent_type type,
+			      dynevent_create_fn_t run_command);
+
+typedef int (*dynevent_check_arg_fn_t)(void *data);
+
+struct dynevent_arg {
+	const char		*str;
+	char			separator; /* e.g. ';', ',', or nothing */
+};
+
+extern void dynevent_arg_init(struct dynevent_arg *arg,
+			      char separator);
+extern int dynevent_arg_add(struct dynevent_cmd *cmd,
+			    struct dynevent_arg *arg,
+			    dynevent_check_arg_fn_t check_arg);
+
+struct dynevent_arg_pair {
+	const char		*lhs;
+	const char		*rhs;
+	char			operator; /* e.g. '=' or nothing */
+	char			separator; /* e.g. ';', ',', or nothing */
+};
+
+extern void dynevent_arg_pair_init(struct dynevent_arg_pair *arg_pair,
+				   char operator, char separator);
+
+extern int dynevent_arg_pair_add(struct dynevent_cmd *cmd,
+				 struct dynevent_arg_pair *arg_pair,
+				 dynevent_check_arg_fn_t check_arg);
+extern int dynevent_str_add(struct dynevent_cmd *cmd, const char *str);
+
 #endif
diff --git a/kernel/trace/trace_entries.h b/kernel/trace/trace_entries.h
index 3e9d81608284..f22746f3c132 100644
--- a/kernel/trace/trace_entries.h
+++ b/kernel/trace/trace_entries.h
@@ -164,7 +164,7 @@ FTRACE_ENTRY(kernel_stack, stack_entry,
 
 	F_STRUCT(
 		__field(	int,		size	)
-		__dynamic_array(unsigned long,	caller	)
+		__array(	unsigned long,	caller,	FTRACE_STACK_ENTRIES	)
 	),
 
 	F_printk("\t=> %ps\n\t=> %ps\n\t=> %ps\n"
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index fcd3975a88d1..f38234ecea18 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -238,7 +238,7 @@ bool trace_event_ignore_this_pid(struct trace_event_file *trace_file)
 	if (!pid_list)
 		return false;
 
-	data = this_cpu_ptr(tr->trace_buffer.data);
+	data = this_cpu_ptr(tr->array_buffer.data);
 
 	return data->ignore_pid;
 }
@@ -273,6 +273,7 @@ void *trace_event_buffer_reserve(struct trace_event_buffer *fbuffer,
 	if (!fbuffer->event)
 		return NULL;
 
+	fbuffer->regs = NULL;
 	fbuffer->entry = ring_buffer_event_data(fbuffer->event);
 	return fbuffer->entry;
 }
@@ -547,7 +548,7 @@ event_filter_pid_sched_switch_probe_pre(void *data, bool preempt,
 
 	pid_list = rcu_dereference_sched(tr->filtered_pids);
 
-	this_cpu_write(tr->trace_buffer.data->ignore_pid,
+	this_cpu_write(tr->array_buffer.data->ignore_pid,
 		       trace_ignore_this_task(pid_list, prev) &&
 		       trace_ignore_this_task(pid_list, next));
 }
@@ -561,7 +562,7 @@ event_filter_pid_sched_switch_probe_post(void *data, bool preempt,
 
 	pid_list = rcu_dereference_sched(tr->filtered_pids);
 
-	this_cpu_write(tr->trace_buffer.data->ignore_pid,
+	this_cpu_write(tr->array_buffer.data->ignore_pid,
 		       trace_ignore_this_task(pid_list, next));
 }
 
@@ -572,12 +573,12 @@ event_filter_pid_sched_wakeup_probe_pre(void *data, struct task_struct *task)
 	struct trace_pid_list *pid_list;
 
 	/* Nothing to do if we are already tracing */
-	if (!this_cpu_read(tr->trace_buffer.data->ignore_pid))
+	if (!this_cpu_read(tr->array_buffer.data->ignore_pid))
 		return;
 
 	pid_list = rcu_dereference_sched(tr->filtered_pids);
 
-	this_cpu_write(tr->trace_buffer.data->ignore_pid,
+	this_cpu_write(tr->array_buffer.data->ignore_pid,
 		       trace_ignore_this_task(pid_list, task));
 }
 
@@ -588,13 +589,13 @@ event_filter_pid_sched_wakeup_probe_post(void *data, struct task_struct *task)
 	struct trace_pid_list *pid_list;
 
 	/* Nothing to do if we are not tracing */
-	if (this_cpu_read(tr->trace_buffer.data->ignore_pid))
+	if (this_cpu_read(tr->array_buffer.data->ignore_pid))
 		return;
 
 	pid_list = rcu_dereference_sched(tr->filtered_pids);
 
 	/* Set tracing if current is enabled */
-	this_cpu_write(tr->trace_buffer.data->ignore_pid,
+	this_cpu_write(tr->array_buffer.data->ignore_pid,
 		       trace_ignore_this_task(pid_list, current));
 }
 
@@ -626,7 +627,7 @@ static void __ftrace_clear_event_pids(struct trace_array *tr)
 	}
 
 	for_each_possible_cpu(cpu)
-		per_cpu_ptr(tr->trace_buffer.data, cpu)->ignore_pid = false;
+		per_cpu_ptr(tr->array_buffer.data, cpu)->ignore_pid = false;
 
 	rcu_assign_pointer(tr->filtered_pids, NULL);
 
@@ -1595,7 +1596,7 @@ static void ignore_task_cpu(void *data)
 	pid_list = rcu_dereference_protected(tr->filtered_pids,
 					     mutex_is_locked(&event_mutex));
 
-	this_cpu_write(tr->trace_buffer.data->ignore_pid,
+	this_cpu_write(tr->array_buffer.data->ignore_pid,
 		       trace_ignore_this_task(pid_list, current));
 }
 
@@ -2553,6 +2554,91 @@ find_event_file(struct trace_array *tr, const char *system, const char *event)
 	return file;
 }
 
+/**
+ * trace_get_event_file - Find and return a trace event file
+ * @instance: The name of the trace instance containing the event
+ * @system: The name of the system containing the event
+ * @event: The name of the event
+ *
+ * Return a trace event file given the trace instance name, trace
+ * system, and trace event name.  If the instance name is NULL, it
+ * refers to the top-level trace array.
+ *
+ * This function will look it up and return it if found, after calling
+ * trace_array_get() to prevent the instance from going away, and
+ * increment the event's module refcount to prevent it from being
+ * removed.
+ *
+ * To release the file, call trace_put_event_file(), which will call
+ * trace_array_put() and decrement the event's module refcount.
+ *
+ * Return: The trace event on success, ERR_PTR otherwise.
+ */
+struct trace_event_file *trace_get_event_file(const char *instance,
+					      const char *system,
+					      const char *event)
+{
+	struct trace_array *tr = top_trace_array();
+	struct trace_event_file *file = NULL;
+	int ret = -EINVAL;
+
+	if (instance) {
+		tr = trace_array_find_get(instance);
+		if (!tr)
+			return ERR_PTR(-ENOENT);
+	} else {
+		ret = trace_array_get(tr);
+		if (ret)
+			return ERR_PTR(ret);
+	}
+
+	mutex_lock(&event_mutex);
+
+	file = find_event_file(tr, system, event);
+	if (!file) {
+		trace_array_put(tr);
+		ret = -EINVAL;
+		goto out;
+	}
+
+	/* Don't let event modules unload while in use */
+	ret = try_module_get(file->event_call->mod);
+	if (!ret) {
+		trace_array_put(tr);
+		ret = -EBUSY;
+		goto out;
+	}
+
+	ret = 0;
+ out:
+	mutex_unlock(&event_mutex);
+
+	if (ret)
+		file = ERR_PTR(ret);
+
+	return file;
+}
+EXPORT_SYMBOL_GPL(trace_get_event_file);
+
+/**
+ * trace_put_event_file - Release a file from trace_get_event_file()
+ * @file: The trace event file
+ *
+ * If a file was retrieved using trace_get_event_file(), this should
+ * be called when it's no longer needed.  It will cancel the previous
+ * trace_array_get() called by that function, and decrement the
+ * event's module refcount.
+ */
+void trace_put_event_file(struct trace_event_file *file)
+{
+	mutex_lock(&event_mutex);
+	module_put(file->event_call->mod);
+	mutex_unlock(&event_mutex);
+
+	trace_array_put(file->tr);
+}
+EXPORT_SYMBOL_GPL(trace_put_event_file);
+
 #ifdef CONFIG_DYNAMIC_FTRACE
 
 /* Avoid typos */
@@ -3409,8 +3495,8 @@ static void __init
 function_test_events_call(unsigned long ip, unsigned long parent_ip,
 			  struct ftrace_ops *op, struct pt_regs *pt_regs)
 {
+	struct trace_buffer *buffer;
 	struct ring_buffer_event *event;
-	struct ring_buffer *buffer;
 	struct ftrace_entry *entry;
 	unsigned long flags;
 	long disabled;
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index f2896d13001b..e7ce7cdac62f 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -66,7 +66,12 @@
 	C(INVALID_SUBSYS_EVENT,	"Invalid subsystem or event name"),	\
 	C(INVALID_REF_KEY,	"Using variable references in keys not supported"), \
 	C(VAR_NOT_FOUND,	"Couldn't find variable"),		\
-	C(FIELD_NOT_FOUND,	"Couldn't find field"),
+	C(FIELD_NOT_FOUND,	"Couldn't find field"),			\
+	C(EMPTY_ASSIGNMENT,	"Empty assignment"),			\
+	C(INVALID_SORT_MODIFIER,"Invalid sort modifier"),		\
+	C(EMPTY_SORT_FIELD,	"Empty sort field"),			\
+	C(TOO_MANY_SORT_FIELDS,	"Too many sort fields (Max = 2)"),	\
+	C(INVALID_SORT_FIELD,	"Sort field must be a key or a val"),
 
 #undef C
 #define C(a, b)		HIST_ERR_##a
@@ -375,7 +380,7 @@ struct hist_trigger_data {
 	unsigned int			n_save_var_str;
 };
 
-static int synth_event_create(int argc, const char **argv);
+static int create_synth_event(int argc, const char **argv);
 static int synth_event_show(struct seq_file *m, struct dyn_event *ev);
 static int synth_event_release(struct dyn_event *ev);
 static bool synth_event_is_busy(struct dyn_event *ev);
@@ -383,7 +388,7 @@ static bool synth_event_match(const char *system, const char *event,
 			int argc, const char **argv, struct dyn_event *ev);
 
 static struct dyn_event_operations synth_event_ops = {
-	.create = synth_event_create,
+	.create = create_synth_event,
 	.show = synth_event_show,
 	.is_busy = synth_event_is_busy,
 	.free = synth_event_release,
@@ -394,6 +399,7 @@ struct synth_field {
 	char *type;
 	char *name;
 	size_t size;
+	unsigned int offset;
 	bool is_signed;
 	bool is_string;
 };
@@ -408,6 +414,7 @@ struct synth_event {
 	struct trace_event_class		class;
 	struct trace_event_call			call;
 	struct tracepoint			*tp;
+	struct module				*mod;
 };
 
 static bool is_synth_event(struct dyn_event *ev)
@@ -470,11 +477,12 @@ struct action_data {
 	 * When a histogram trigger is hit, the values of any
 	 * references to variables, including variables being passed
 	 * as parameters to synthetic events, are collected into a
-	 * var_ref_vals array.  This var_ref_idx is the index of the
-	 * first param in the array to be passed to the synthetic
-	 * event invocation.
+	 * var_ref_vals array.  This var_ref_idx array is an array of
+	 * indices into the var_ref_vals array, one for each synthetic
+	 * event param, and is passed to the synthetic event
+	 * invocation.
 	 */
-	unsigned int		var_ref_idx;
+	unsigned int		var_ref_idx[TRACING_MAP_VARS_MAX];
 	struct synth_event	*synth_event;
 	bool			use_trace_keyword;
 	char			*synth_event_name;
@@ -608,7 +616,8 @@ static void last_cmd_set(struct trace_event_file *file, char *str)
 	if (!str)
 		return;
 
-	strncpy(last_cmd, str, MAX_FILTER_STR_VAL - 1);
+	strcpy(last_cmd, "hist:");
+	strncat(last_cmd, str, MAX_FILTER_STR_VAL - 1 - sizeof("hist:"));
 
 	if (file) {
 		call = file->event_call;
@@ -662,6 +671,8 @@ static int synth_event_define_fields(struct trace_event_call *call)
 		if (ret)
 			break;
 
+		event->fields[i]->offset = n_u64;
+
 		if (event->fields[i]->is_string) {
 			offset += STR_VAR_LEN_MAX;
 			n_u64 += STR_VAR_LEN_MAX / sizeof(u64);
@@ -834,7 +845,7 @@ static enum print_line_t print_synth_event(struct trace_iterator *iter,
 		fmt = synth_field_fmt(se->fields[i]->type);
 
 		/* parameter types */
-		if (tr->trace_flags & TRACE_ITER_VERBOSE)
+		if (tr && tr->trace_flags & TRACE_ITER_VERBOSE)
 			trace_seq_printf(s, "%s ", fmt);
 
 		snprintf(print_fmt, sizeof(print_fmt), "%%s=%s%%s", fmt);
@@ -875,14 +886,14 @@ static struct trace_event_functions synth_event_funcs = {
 
 static notrace void trace_event_raw_event_synth(void *__data,
 						u64 *var_ref_vals,
-						unsigned int var_ref_idx)
+						unsigned int *var_ref_idx)
 {
 	struct trace_event_file *trace_file = __data;
 	struct synth_trace_event *entry;
 	struct trace_event_buffer fbuffer;
-	struct ring_buffer *buffer;
+	struct trace_buffer *buffer;
 	struct synth_event *event;
-	unsigned int i, n_u64;
+	unsigned int i, n_u64, val_idx;
 	int fields_size = 0;
 
 	event = trace_file->event_call->data;
@@ -896,7 +907,7 @@ static notrace void trace_event_raw_event_synth(void *__data,
 	 * Avoid ring buffer recursion detection, as this event
 	 * is being performed within another event.
 	 */
-	buffer = trace_file->tr->trace_buffer.buffer;
+	buffer = trace_file->tr->array_buffer.buffer;
 	ring_buffer_nest_start(buffer);
 
 	entry = trace_event_buffer_reserve(&fbuffer, trace_file,
@@ -905,15 +916,16 @@ static notrace void trace_event_raw_event_synth(void *__data,
 		goto out;
 
 	for (i = 0, n_u64 = 0; i < event->n_fields; i++) {
+		val_idx = var_ref_idx[i];
 		if (event->fields[i]->is_string) {
-			char *str_val = (char *)(long)var_ref_vals[var_ref_idx + i];
+			char *str_val = (char *)(long)var_ref_vals[val_idx];
 			char *str_field = (char *)&entry->fields[n_u64];
 
 			strscpy(str_field, str_val, STR_VAR_LEN_MAX);
 			n_u64 += STR_VAR_LEN_MAX / sizeof(u64);
 		} else {
 			struct synth_field *field = event->fields[i];
-			u64 val = var_ref_vals[var_ref_idx + i];
+			u64 val = var_ref_vals[val_idx];
 
 			switch (field->size) {
 			case 1:
@@ -1113,10 +1125,10 @@ static struct tracepoint *alloc_synth_tracepoint(char *name)
 }
 
 typedef void (*synth_probe_func_t) (void *__data, u64 *var_ref_vals,
-				    unsigned int var_ref_idx);
+				    unsigned int *var_ref_idx);
 
 static inline void trace_synth(struct synth_event *event, u64 *var_ref_vals,
-			       unsigned int var_ref_idx)
+			       unsigned int *var_ref_idx)
 {
 	struct tracepoint *tp = event->tp;
 
@@ -1293,6 +1305,273 @@ struct hist_var_data {
 	struct hist_trigger_data *hist_data;
 };
 
+static int synth_event_check_arg_fn(void *data)
+{
+	struct dynevent_arg_pair *arg_pair = data;
+	int size;
+
+	size = synth_field_size((char *)arg_pair->lhs);
+
+	return size ? 0 : -EINVAL;
+}
+
+/**
+ * synth_event_add_field - Add a new field to a synthetic event cmd
+ * @cmd: A pointer to the dynevent_cmd struct representing the new event
+ * @type: The type of the new field to add
+ * @name: The name of the new field to add
+ *
+ * Add a new field to a synthetic event cmd object.  Field ordering is in
+ * the same order the fields are added.
+ *
+ * See synth_field_size() for available types. If field_name contains
+ * [n] the field is considered to be an array.
+ *
+ * Return: 0 if successful, error otherwise.
+ */
+int synth_event_add_field(struct dynevent_cmd *cmd, const char *type,
+			  const char *name)
+{
+	struct dynevent_arg_pair arg_pair;
+	int ret;
+
+	if (cmd->type != DYNEVENT_TYPE_SYNTH)
+		return -EINVAL;
+
+	if (!type || !name)
+		return -EINVAL;
+
+	dynevent_arg_pair_init(&arg_pair, 0, ';');
+
+	arg_pair.lhs = type;
+	arg_pair.rhs = name;
+
+	ret = dynevent_arg_pair_add(cmd, &arg_pair, synth_event_check_arg_fn);
+	if (ret)
+		return ret;
+
+	if (++cmd->n_fields > SYNTH_FIELDS_MAX)
+		ret = -EINVAL;
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(synth_event_add_field);
+
+/**
+ * synth_event_add_field_str - Add a new field to a synthetic event cmd
+ * @cmd: A pointer to the dynevent_cmd struct representing the new event
+ * @type_name: The type and name of the new field to add, as a single string
+ *
+ * Add a new field to a synthetic event cmd object, as a single
+ * string.  The @type_name string is expected to be of the form 'type
+ * name', which will be appended by ';'.  No sanity checking is done -
+ * what's passed in is assumed to already be well-formed.  Field
+ * ordering is in the same order the fields are added.
+ *
+ * See synth_field_size() for available types. If field_name contains
+ * [n] the field is considered to be an array.
+ *
+ * Return: 0 if successful, error otherwise.
+ */
+int synth_event_add_field_str(struct dynevent_cmd *cmd, const char *type_name)
+{
+	struct dynevent_arg arg;
+	int ret;
+
+	if (cmd->type != DYNEVENT_TYPE_SYNTH)
+		return -EINVAL;
+
+	if (!type_name)
+		return -EINVAL;
+
+	dynevent_arg_init(&arg, ';');
+
+	arg.str = type_name;
+
+	ret = dynevent_arg_add(cmd, &arg, NULL);
+	if (ret)
+		return ret;
+
+	if (++cmd->n_fields > SYNTH_FIELDS_MAX)
+		ret = -EINVAL;
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(synth_event_add_field_str);
+
+/**
+ * synth_event_add_fields - Add multiple fields to a synthetic event cmd
+ * @cmd: A pointer to the dynevent_cmd struct representing the new event
+ * @fields: An array of type/name field descriptions
+ * @n_fields: The number of field descriptions contained in the fields array
+ *
+ * Add a new set of fields to a synthetic event cmd object.  The event
+ * fields that will be defined for the event should be passed in as an
+ * array of struct synth_field_desc, and the number of elements in the
+ * array passed in as n_fields.  Field ordering will retain the
+ * ordering given in the fields array.
+ *
+ * See synth_field_size() for available types. If field_name contains
+ * [n] the field is considered to be an array.
+ *
+ * Return: 0 if successful, error otherwise.
+ */
+int synth_event_add_fields(struct dynevent_cmd *cmd,
+			   struct synth_field_desc *fields,
+			   unsigned int n_fields)
+{
+	unsigned int i;
+	int ret = 0;
+
+	for (i = 0; i < n_fields; i++) {
+		if (fields[i].type == NULL || fields[i].name == NULL) {
+			ret = -EINVAL;
+			break;
+		}
+
+		ret = synth_event_add_field(cmd, fields[i].type, fields[i].name);
+		if (ret)
+			break;
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(synth_event_add_fields);
+
+/**
+ * __synth_event_gen_cmd_start - Start a synthetic event command from arg list
+ * @cmd: A pointer to the dynevent_cmd struct representing the new event
+ * @name: The name of the synthetic event
+ * @mod: The module creating the event, NULL if not created from a module
+ * @args: Variable number of arg (pairs), one pair for each field
+ *
+ * NOTE: Users normally won't want to call this function directly, but
+ * rather use the synth_event_gen_cmd_start() wrapper, which
+ * automatically adds a NULL to the end of the arg list.  If this
+ * function is used directly, make sure the last arg in the variable
+ * arg list is NULL.
+ *
+ * Generate a synthetic event command to be executed by
+ * synth_event_gen_cmd_end().  This function can be used to generate
+ * the complete command or only the first part of it; in the latter
+ * case, synth_event_add_field(), synth_event_add_field_str(), or
+ * synth_event_add_fields() can be used to add more fields following
+ * this.
+ *
+ * There should be an even number variable args, each pair consisting
+ * of a type followed by a field name.
+ *
+ * See synth_field_size() for available types. If field_name contains
+ * [n] the field is considered to be an array.
+ *
+ * Return: 0 if successful, error otherwise.
+ */
+int __synth_event_gen_cmd_start(struct dynevent_cmd *cmd, const char *name,
+				struct module *mod, ...)
+{
+	struct dynevent_arg arg;
+	va_list args;
+	int ret;
+
+	cmd->event_name = name;
+	cmd->private_data = mod;
+
+	if (cmd->type != DYNEVENT_TYPE_SYNTH)
+		return -EINVAL;
+
+	dynevent_arg_init(&arg, 0);
+	arg.str = name;
+	ret = dynevent_arg_add(cmd, &arg, NULL);
+	if (ret)
+		return ret;
+
+	va_start(args, mod);
+	for (;;) {
+		const char *type, *name;
+
+		type = va_arg(args, const char *);
+		if (!type)
+			break;
+		name = va_arg(args, const char *);
+		if (!name)
+			break;
+
+		if (++cmd->n_fields > SYNTH_FIELDS_MAX) {
+			ret = -EINVAL;
+			break;
+		}
+
+		ret = synth_event_add_field(cmd, type, name);
+		if (ret)
+			break;
+	}
+	va_end(args);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(__synth_event_gen_cmd_start);
+
+/**
+ * synth_event_gen_cmd_array_start - Start synthetic event command from an array
+ * @cmd: A pointer to the dynevent_cmd struct representing the new event
+ * @name: The name of the synthetic event
+ * @fields: An array of type/name field descriptions
+ * @n_fields: The number of field descriptions contained in the fields array
+ *
+ * Generate a synthetic event command to be executed by
+ * synth_event_gen_cmd_end().  This function can be used to generate
+ * the complete command or only the first part of it; in the latter
+ * case, synth_event_add_field(), synth_event_add_field_str(), or
+ * synth_event_add_fields() can be used to add more fields following
+ * this.
+ *
+ * The event fields that will be defined for the event should be
+ * passed in as an array of struct synth_field_desc, and the number of
+ * elements in the array passed in as n_fields.  Field ordering will
+ * retain the ordering given in the fields array.
+ *
+ * See synth_field_size() for available types. If field_name contains
+ * [n] the field is considered to be an array.
+ *
+ * Return: 0 if successful, error otherwise.
+ */
+int synth_event_gen_cmd_array_start(struct dynevent_cmd *cmd, const char *name,
+				    struct module *mod,
+				    struct synth_field_desc *fields,
+				    unsigned int n_fields)
+{
+	struct dynevent_arg arg;
+	unsigned int i;
+	int ret = 0;
+
+	cmd->event_name = name;
+	cmd->private_data = mod;
+
+	if (cmd->type != DYNEVENT_TYPE_SYNTH)
+		return -EINVAL;
+
+	if (n_fields > SYNTH_FIELDS_MAX)
+		return -EINVAL;
+
+	dynevent_arg_init(&arg, 0);
+	arg.str = name;
+	ret = dynevent_arg_add(cmd, &arg, NULL);
+	if (ret)
+		return ret;
+
+	for (i = 0; i < n_fields; i++) {
+		if (fields[i].type == NULL || fields[i].name == NULL)
+			return -EINVAL;
+
+		ret = synth_event_add_field(cmd, fields[i].type, fields[i].name);
+		if (ret)
+			break;
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(synth_event_gen_cmd_array_start);
+
 static int __create_synth_event(int argc, const char *name, const char **argv)
 {
 	struct synth_field *field, *fields[SYNTH_FIELDS_MAX];
@@ -1361,29 +1640,123 @@ static int __create_synth_event(int argc, const char *name, const char **argv)
 	goto out;
 }
 
+/**
+ * synth_event_create - Create a new synthetic event
+ * @name: The name of the new sythetic event
+ * @fields: An array of type/name field descriptions
+ * @n_fields: The number of field descriptions contained in the fields array
+ * @mod: The module creating the event, NULL if not created from a module
+ *
+ * Create a new synthetic event with the given name under the
+ * trace/events/synthetic/ directory.  The event fields that will be
+ * defined for the event should be passed in as an array of struct
+ * synth_field_desc, and the number elements in the array passed in as
+ * n_fields. Field ordering will retain the ordering given in the
+ * fields array.
+ *
+ * If the new synthetic event is being created from a module, the mod
+ * param must be non-NULL.  This will ensure that the trace buffer
+ * won't contain unreadable events.
+ *
+ * The new synth event should be deleted using synth_event_delete()
+ * function.  The new synthetic event can be generated from modules or
+ * other kernel code using trace_synth_event() and related functions.
+ *
+ * Return: 0 if successful, error otherwise.
+ */
+int synth_event_create(const char *name, struct synth_field_desc *fields,
+		       unsigned int n_fields, struct module *mod)
+{
+	struct dynevent_cmd cmd;
+	char *buf;
+	int ret;
+
+	buf = kzalloc(MAX_DYNEVENT_CMD_LEN, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	synth_event_cmd_init(&cmd, buf, MAX_DYNEVENT_CMD_LEN);
+
+	ret = synth_event_gen_cmd_array_start(&cmd, name, mod,
+					      fields, n_fields);
+	if (ret)
+		goto out;
+
+	ret = synth_event_gen_cmd_end(&cmd);
+ out:
+	kfree(buf);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(synth_event_create);
+
+static int destroy_synth_event(struct synth_event *se)
+{
+	int ret;
+
+	if (se->ref)
+		ret = -EBUSY;
+	else {
+		ret = unregister_synth_event(se);
+		if (!ret) {
+			dyn_event_remove(&se->devent);
+			free_synth_event(se);
+		}
+	}
+
+	return ret;
+}
+
+/**
+ * synth_event_delete - Delete a synthetic event
+ * @event_name: The name of the new sythetic event
+ *
+ * Delete a synthetic event that was created with synth_event_create().
+ *
+ * Return: 0 if successful, error otherwise.
+ */
+int synth_event_delete(const char *event_name)
+{
+	struct synth_event *se = NULL;
+	struct module *mod = NULL;
+	int ret = -ENOENT;
+
+	mutex_lock(&event_mutex);
+	se = find_synth_event(event_name);
+	if (se) {
+		mod = se->mod;
+		ret = destroy_synth_event(se);
+	}
+	mutex_unlock(&event_mutex);
+
+	if (mod) {
+		mutex_lock(&trace_types_lock);
+		/*
+		 * It is safest to reset the ring buffer if the module
+		 * being unloaded registered any events that were
+		 * used. The only worry is if a new module gets
+		 * loaded, and takes on the same id as the events of
+		 * this module. When printing out the buffer, traced
+		 * events left over from this module may be passed to
+		 * the new module events and unexpected results may
+		 * occur.
+		 */
+		tracing_reset_all_online_cpus();
+		mutex_unlock(&trace_types_lock);
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(synth_event_delete);
+
 static int create_or_delete_synth_event(int argc, char **argv)
 {
 	const char *name = argv[0];
-	struct synth_event *event = NULL;
 	int ret;
 
 	/* trace_run_command() ensures argc != 0 */
 	if (name[0] == '!') {
-		mutex_lock(&event_mutex);
-		event = find_synth_event(name + 1);
-		if (event) {
-			if (event->ref)
-				ret = -EBUSY;
-			else {
-				ret = unregister_synth_event(event);
-				if (!ret) {
-					dyn_event_remove(&event->devent);
-					free_synth_event(event);
-				}
-			}
-		} else
-			ret = -ENOENT;
-		mutex_unlock(&event_mutex);
+		ret = synth_event_delete(name + 1);
 		return ret;
 	}
 
@@ -1391,7 +1764,474 @@ static int create_or_delete_synth_event(int argc, char **argv)
 	return ret == -ECANCELED ? -EINVAL : ret;
 }
 
-static int synth_event_create(int argc, const char **argv)
+static int synth_event_run_command(struct dynevent_cmd *cmd)
+{
+	struct synth_event *se;
+	int ret;
+
+	ret = trace_run_command(cmd->seq.buffer, create_or_delete_synth_event);
+	if (ret)
+		return ret;
+
+	se = find_synth_event(cmd->event_name);
+	if (WARN_ON(!se))
+		return -ENOENT;
+
+	se->mod = cmd->private_data;
+
+	return ret;
+}
+
+/**
+ * synth_event_cmd_init - Initialize a synthetic event command object
+ * @cmd: A pointer to the dynevent_cmd struct representing the new event
+ * @buf: A pointer to the buffer used to build the command
+ * @maxlen: The length of the buffer passed in @buf
+ *
+ * Initialize a synthetic event command object.  Use this before
+ * calling any of the other dyenvent_cmd functions.
+ */
+void synth_event_cmd_init(struct dynevent_cmd *cmd, char *buf, int maxlen)
+{
+	dynevent_cmd_init(cmd, buf, maxlen, DYNEVENT_TYPE_SYNTH,
+			  synth_event_run_command);
+}
+EXPORT_SYMBOL_GPL(synth_event_cmd_init);
+
+/**
+ * synth_event_trace - Trace a synthetic event
+ * @file: The trace_event_file representing the synthetic event
+ * @n_vals: The number of values in vals
+ * @args: Variable number of args containing the event values
+ *
+ * Trace a synthetic event using the values passed in the variable
+ * argument list.
+ *
+ * The argument list should be a list 'n_vals' u64 values.  The number
+ * of vals must match the number of field in the synthetic event, and
+ * must be in the same order as the synthetic event fields.
+ *
+ * All vals should be cast to u64, and string vals are just pointers
+ * to strings, cast to u64.  Strings will be copied into space
+ * reserved in the event for the string, using these pointers.
+ *
+ * Return: 0 on success, err otherwise.
+ */
+int synth_event_trace(struct trace_event_file *file, unsigned int n_vals, ...)
+{
+	struct trace_event_buffer fbuffer;
+	struct synth_trace_event *entry;
+	struct trace_buffer *buffer;
+	struct synth_event *event;
+	unsigned int i, n_u64;
+	int fields_size = 0;
+	va_list args;
+	int ret = 0;
+
+	/*
+	 * Normal event generation doesn't get called at all unless
+	 * the ENABLED bit is set (which attaches the probe thus
+	 * allowing this code to be called, etc).  Because this is
+	 * called directly by the user, we don't have that but we
+	 * still need to honor not logging when disabled.
+	 */
+	if (!(file->flags & EVENT_FILE_FL_ENABLED))
+		return 0;
+
+	event = file->event_call->data;
+
+	if (n_vals != event->n_fields)
+		return -EINVAL;
+
+	if (trace_trigger_soft_disabled(file))
+		return -EINVAL;
+
+	fields_size = event->n_u64 * sizeof(u64);
+
+	/*
+	 * Avoid ring buffer recursion detection, as this event
+	 * is being performed within another event.
+	 */
+	buffer = file->tr->array_buffer.buffer;
+	ring_buffer_nest_start(buffer);
+
+	entry = trace_event_buffer_reserve(&fbuffer, file,
+					   sizeof(*entry) + fields_size);
+	if (!entry) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	va_start(args, n_vals);
+	for (i = 0, n_u64 = 0; i < event->n_fields; i++) {
+		u64 val;
+
+		val = va_arg(args, u64);
+
+		if (event->fields[i]->is_string) {
+			char *str_val = (char *)(long)val;
+			char *str_field = (char *)&entry->fields[n_u64];
+
+			strscpy(str_field, str_val, STR_VAR_LEN_MAX);
+			n_u64 += STR_VAR_LEN_MAX / sizeof(u64);
+		} else {
+			entry->fields[n_u64] = val;
+			n_u64++;
+		}
+	}
+	va_end(args);
+
+	trace_event_buffer_commit(&fbuffer);
+out:
+	ring_buffer_nest_end(buffer);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(synth_event_trace);
+
+/**
+ * synth_event_trace_array - Trace a synthetic event from an array
+ * @file: The trace_event_file representing the synthetic event
+ * @vals: Array of values
+ * @n_vals: The number of values in vals
+ *
+ * Trace a synthetic event using the values passed in as 'vals'.
+ *
+ * The 'vals' array is just an array of 'n_vals' u64.  The number of
+ * vals must match the number of field in the synthetic event, and
+ * must be in the same order as the synthetic event fields.
+ *
+ * All vals should be cast to u64, and string vals are just pointers
+ * to strings, cast to u64.  Strings will be copied into space
+ * reserved in the event for the string, using these pointers.
+ *
+ * Return: 0 on success, err otherwise.
+ */
+int synth_event_trace_array(struct trace_event_file *file, u64 *vals,
+			    unsigned int n_vals)
+{
+	struct trace_event_buffer fbuffer;
+	struct synth_trace_event *entry;
+	struct trace_buffer *buffer;
+	struct synth_event *event;
+	unsigned int i, n_u64;
+	int fields_size = 0;
+	int ret = 0;
+
+	/*
+	 * Normal event generation doesn't get called at all unless
+	 * the ENABLED bit is set (which attaches the probe thus
+	 * allowing this code to be called, etc).  Because this is
+	 * called directly by the user, we don't have that but we
+	 * still need to honor not logging when disabled.
+	 */
+	if (!(file->flags & EVENT_FILE_FL_ENABLED))
+		return 0;
+
+	event = file->event_call->data;
+
+	if (n_vals != event->n_fields)
+		return -EINVAL;
+
+	if (trace_trigger_soft_disabled(file))
+		return -EINVAL;
+
+	fields_size = event->n_u64 * sizeof(u64);
+
+	/*
+	 * Avoid ring buffer recursion detection, as this event
+	 * is being performed within another event.
+	 */
+	buffer = file->tr->array_buffer.buffer;
+	ring_buffer_nest_start(buffer);
+
+	entry = trace_event_buffer_reserve(&fbuffer, file,
+					   sizeof(*entry) + fields_size);
+	if (!entry) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	for (i = 0, n_u64 = 0; i < event->n_fields; i++) {
+		if (event->fields[i]->is_string) {
+			char *str_val = (char *)(long)vals[i];
+			char *str_field = (char *)&entry->fields[n_u64];
+
+			strscpy(str_field, str_val, STR_VAR_LEN_MAX);
+			n_u64 += STR_VAR_LEN_MAX / sizeof(u64);
+		} else {
+			entry->fields[n_u64] = vals[i];
+			n_u64++;
+		}
+	}
+
+	trace_event_buffer_commit(&fbuffer);
+out:
+	ring_buffer_nest_end(buffer);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(synth_event_trace_array);
+
+/**
+ * synth_event_trace_start - Start piecewise synthetic event trace
+ * @file: The trace_event_file representing the synthetic event
+ * @trace_state: A pointer to object tracking the piecewise trace state
+ *
+ * Start the trace of a synthetic event field-by-field rather than all
+ * at once.
+ *
+ * This function 'opens' an event trace, which means space is reserved
+ * for the event in the trace buffer, after which the event's
+ * individual field values can be set through either
+ * synth_event_add_next_val() or synth_event_add_val().
+ *
+ * A pointer to a trace_state object is passed in, which will keep
+ * track of the current event trace state until the event trace is
+ * closed (and the event finally traced) using
+ * synth_event_trace_end().
+ *
+ * Note that synth_event_trace_end() must be called after all values
+ * have been added for each event trace, regardless of whether adding
+ * all field values succeeded or not.
+ *
+ * Note also that for a given event trace, all fields must be added
+ * using either synth_event_add_next_val() or synth_event_add_val()
+ * but not both together or interleaved.
+ *
+ * Return: 0 on success, err otherwise.
+ */
+int synth_event_trace_start(struct trace_event_file *file,
+			    struct synth_event_trace_state *trace_state)
+{
+	struct synth_trace_event *entry;
+	int fields_size = 0;
+	int ret = 0;
+
+	if (!trace_state) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	memset(trace_state, '\0', sizeof(*trace_state));
+
+	/*
+	 * Normal event tracing doesn't get called at all unless the
+	 * ENABLED bit is set (which attaches the probe thus allowing
+	 * this code to be called, etc).  Because this is called
+	 * directly by the user, we don't have that but we still need
+	 * to honor not logging when disabled.  For the the iterated
+	 * trace case, we save the enabed state upon start and just
+	 * ignore the following data calls.
+	 */
+	if (!(file->flags & EVENT_FILE_FL_ENABLED)) {
+		trace_state->enabled = false;
+		goto out;
+	}
+
+	trace_state->enabled = true;
+
+	trace_state->event = file->event_call->data;
+
+	if (trace_trigger_soft_disabled(file)) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	fields_size = trace_state->event->n_u64 * sizeof(u64);
+
+	/*
+	 * Avoid ring buffer recursion detection, as this event
+	 * is being performed within another event.
+	 */
+	trace_state->buffer = file->tr->array_buffer.buffer;
+	ring_buffer_nest_start(trace_state->buffer);
+
+	entry = trace_event_buffer_reserve(&trace_state->fbuffer, file,
+					   sizeof(*entry) + fields_size);
+	if (!entry) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	trace_state->entry = entry;
+out:
+	return ret;
+}
+EXPORT_SYMBOL_GPL(synth_event_trace_start);
+
+static int __synth_event_add_val(const char *field_name, u64 val,
+				 struct synth_event_trace_state *trace_state)
+{
+	struct synth_field *field = NULL;
+	struct synth_trace_event *entry;
+	struct synth_event *event;
+	int i, ret = 0;
+
+	if (!trace_state) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	/* can't mix add_next_synth_val() with add_synth_val() */
+	if (field_name) {
+		if (trace_state->add_next) {
+			ret = -EINVAL;
+			goto out;
+		}
+		trace_state->add_name = true;
+	} else {
+		if (trace_state->add_name) {
+			ret = -EINVAL;
+			goto out;
+		}
+		trace_state->add_next = true;
+	}
+
+	if (!trace_state->enabled)
+		goto out;
+
+	event = trace_state->event;
+	if (trace_state->add_name) {
+		for (i = 0; i < event->n_fields; i++) {
+			field = event->fields[i];
+			if (strcmp(field->name, field_name) == 0)
+				break;
+		}
+		if (!field) {
+			ret = -EINVAL;
+			goto out;
+		}
+	} else {
+		if (trace_state->cur_field >= event->n_fields) {
+			ret = -EINVAL;
+			goto out;
+		}
+		field = event->fields[trace_state->cur_field++];
+	}
+
+	entry = trace_state->entry;
+	if (field->is_string) {
+		char *str_val = (char *)(long)val;
+		char *str_field;
+
+		if (!str_val) {
+			ret = -EINVAL;
+			goto out;
+		}
+
+		str_field = (char *)&entry->fields[field->offset];
+		strscpy(str_field, str_val, STR_VAR_LEN_MAX);
+	} else
+		entry->fields[field->offset] = val;
+ out:
+	return ret;
+}
+
+/**
+ * synth_event_add_next_val - Add the next field's value to an open synth trace
+ * @val: The value to set the next field to
+ * @trace_state: A pointer to object tracking the piecewise trace state
+ *
+ * Set the value of the next field in an event that's been opened by
+ * synth_event_trace_start().
+ *
+ * The val param should be the value cast to u64.  If the value points
+ * to a string, the val param should be a char * cast to u64.
+ *
+ * This function assumes all the fields in an event are to be set one
+ * after another - successive calls to this function are made, one for
+ * each field, in the order of the fields in the event, until all
+ * fields have been set.  If you'd rather set each field individually
+ * without regard to ordering, synth_event_add_val() can be used
+ * instead.
+ *
+ * Note however that synth_event_add_next_val() and
+ * synth_event_add_val() can't be intermixed for a given event trace -
+ * one or the other but not both can be used at the same time.
+ *
+ * Note also that synth_event_trace_end() must be called after all
+ * values have been added for each event trace, regardless of whether
+ * adding all field values succeeded or not.
+ *
+ * Return: 0 on success, err otherwise.
+ */
+int synth_event_add_next_val(u64 val,
+			     struct synth_event_trace_state *trace_state)
+{
+	return __synth_event_add_val(NULL, val, trace_state);
+}
+EXPORT_SYMBOL_GPL(synth_event_add_next_val);
+
+/**
+ * synth_event_add_val - Add a named field's value to an open synth trace
+ * @field_name: The name of the synthetic event field value to set
+ * @val: The value to set the next field to
+ * @trace_state: A pointer to object tracking the piecewise trace state
+ *
+ * Set the value of the named field in an event that's been opened by
+ * synth_event_trace_start().
+ *
+ * The val param should be the value cast to u64.  If the value points
+ * to a string, the val param should be a char * cast to u64.
+ *
+ * This function looks up the field name, and if found, sets the field
+ * to the specified value.  This lookup makes this function more
+ * expensive than synth_event_add_next_val(), so use that or the
+ * none-piecewise synth_event_trace() instead if efficiency is more
+ * important.
+ *
+ * Note however that synth_event_add_next_val() and
+ * synth_event_add_val() can't be intermixed for a given event trace -
+ * one or the other but not both can be used at the same time.
+ *
+ * Note also that synth_event_trace_end() must be called after all
+ * values have been added for each event trace, regardless of whether
+ * adding all field values succeeded or not.
+ *
+ * Return: 0 on success, err otherwise.
+ */
+int synth_event_add_val(const char *field_name, u64 val,
+			struct synth_event_trace_state *trace_state)
+{
+	return __synth_event_add_val(field_name, val, trace_state);
+}
+EXPORT_SYMBOL_GPL(synth_event_add_val);
+
+/**
+ * synth_event_trace_end - End piecewise synthetic event trace
+ * @trace_state: A pointer to object tracking the piecewise trace state
+ *
+ * End the trace of a synthetic event opened by
+ * synth_event_trace__start().
+ *
+ * This function 'closes' an event trace, which basically means that
+ * it commits the reserved event and cleans up other loose ends.
+ *
+ * A pointer to a trace_state object is passed in, which will keep
+ * track of the current event trace state opened with
+ * synth_event_trace_start().
+ *
+ * Note that this function must be called after all values have been
+ * added for each event trace, regardless of whether adding all field
+ * values succeeded or not.
+ *
+ * Return: 0 on success, err otherwise.
+ */
+int synth_event_trace_end(struct synth_event_trace_state *trace_state)
+{
+	if (!trace_state)
+		return -EINVAL;
+
+	trace_event_buffer_commit(&trace_state->fbuffer);
+
+	ring_buffer_nest_end(trace_state->buffer);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(synth_event_trace_end);
+
+static int create_synth_event(int argc, const char **argv)
 {
 	const char *name = argv[0];
 	int len;
@@ -2041,12 +2881,6 @@ static int parse_map_size(char *str)
 	unsigned long size, map_bits;
 	int ret;
 
-	strsep(&str, "=");
-	if (!str) {
-		ret = -EINVAL;
-		goto out;
-	}
-
 	ret = kstrtoul(str, 0, &size);
 	if (ret)
 		goto out;
@@ -2106,25 +2940,25 @@ static int parse_action(char *str, struct hist_trigger_attrs *attrs)
 static int parse_assignment(struct trace_array *tr,
 			    char *str, struct hist_trigger_attrs *attrs)
 {
-	int ret = 0;
+	int len, ret = 0;
 
-	if ((str_has_prefix(str, "key=")) ||
-	    (str_has_prefix(str, "keys="))) {
-		attrs->keys_str = kstrdup(str, GFP_KERNEL);
+	if ((len = str_has_prefix(str, "key=")) ||
+	    (len = str_has_prefix(str, "keys="))) {
+		attrs->keys_str = kstrdup(str + len, GFP_KERNEL);
 		if (!attrs->keys_str) {
 			ret = -ENOMEM;
 			goto out;
 		}
-	} else if ((str_has_prefix(str, "val=")) ||
-		   (str_has_prefix(str, "vals=")) ||
-		   (str_has_prefix(str, "values="))) {
-		attrs->vals_str = kstrdup(str, GFP_KERNEL);
+	} else if ((len = str_has_prefix(str, "val=")) ||
+		   (len = str_has_prefix(str, "vals=")) ||
+		   (len = str_has_prefix(str, "values="))) {
+		attrs->vals_str = kstrdup(str + len, GFP_KERNEL);
 		if (!attrs->vals_str) {
 			ret = -ENOMEM;
 			goto out;
 		}
-	} else if (str_has_prefix(str, "sort=")) {
-		attrs->sort_key_str = kstrdup(str, GFP_KERNEL);
+	} else if ((len = str_has_prefix(str, "sort="))) {
+		attrs->sort_key_str = kstrdup(str + len, GFP_KERNEL);
 		if (!attrs->sort_key_str) {
 			ret = -ENOMEM;
 			goto out;
@@ -2135,12 +2969,8 @@ static int parse_assignment(struct trace_array *tr,
 			ret = -ENOMEM;
 			goto out;
 		}
-	} else if (str_has_prefix(str, "clock=")) {
-		strsep(&str, "=");
-		if (!str) {
-			ret = -EINVAL;
-			goto out;
-		}
+	} else if ((len = str_has_prefix(str, "clock="))) {
+		str += len;
 
 		str = strstrip(str);
 		attrs->clock = kstrdup(str, GFP_KERNEL);
@@ -2148,8 +2978,8 @@ static int parse_assignment(struct trace_array *tr,
 			ret = -ENOMEM;
 			goto out;
 		}
-	} else if (str_has_prefix(str, "size=")) {
-		int map_bits = parse_map_size(str);
+	} else if ((len = str_has_prefix(str, "size="))) {
+		int map_bits = parse_map_size(str + len);
 
 		if (map_bits < 0) {
 			ret = map_bits;
@@ -2189,8 +3019,15 @@ parse_hist_trigger_attrs(struct trace_array *tr, char *trigger_str)
 
 	while (trigger_str) {
 		char *str = strsep(&trigger_str, ":");
+		char *rhs;
 
-		if (strchr(str, '=')) {
+		rhs = strchr(str, '=');
+		if (rhs) {
+			if (!strlen(++rhs)) {
+				ret = -EINVAL;
+				hist_err(tr, HIST_ERR_EMPTY_ASSIGNMENT, errpos(str));
+				goto free;
+			}
 			ret = parse_assignment(tr, str, attrs);
 			if (ret)
 				goto free;
@@ -2661,6 +3498,22 @@ static int init_var_ref(struct hist_field *ref_field,
 	goto out;
 }
 
+static int find_var_ref_idx(struct hist_trigger_data *hist_data,
+			    struct hist_field *var_field)
+{
+	struct hist_field *ref_field;
+	int i;
+
+	for (i = 0; i < hist_data->n_var_refs; i++) {
+		ref_field = hist_data->var_refs[i];
+		if (ref_field->var.idx == var_field->var.idx &&
+		    ref_field->var.hist_data == var_field->hist_data)
+			return i;
+	}
+
+	return -ENOENT;
+}
+
 /**
  * create_var_ref - Create a variable reference and attach it to trigger
  * @hist_data: The trigger that will be referencing the variable
@@ -4146,8 +4999,11 @@ static int check_synth_field(struct synth_event *event,
 
 	field = event->fields[field_pos];
 
-	if (strcmp(field->type, hist_field->type) != 0)
-		return -EINVAL;
+	if (strcmp(field->type, hist_field->type) != 0) {
+		if (field->size != hist_field->size ||
+		    field->is_signed != hist_field->is_signed)
+			return -EINVAL;
+	}
 
 	return 0;
 }
@@ -4234,11 +5090,11 @@ static int trace_action_create(struct hist_trigger_data *hist_data,
 	struct trace_array *tr = hist_data->event_file->tr;
 	char *event_name, *param, *system = NULL;
 	struct hist_field *hist_field, *var_ref;
-	unsigned int i, var_ref_idx;
+	unsigned int i;
 	unsigned int field_pos = 0;
 	struct synth_event *event;
 	char *synth_event_name;
-	int ret = 0;
+	int var_ref_idx, ret = 0;
 
 	lockdep_assert_held(&event_mutex);
 
@@ -4255,8 +5111,6 @@ static int trace_action_create(struct hist_trigger_data *hist_data,
 
 	event->ref++;
 
-	var_ref_idx = hist_data->n_var_refs;
-
 	for (i = 0; i < data->n_params; i++) {
 		char *p;
 
@@ -4305,6 +5159,14 @@ static int trace_action_create(struct hist_trigger_data *hist_data,
 				goto err;
 			}
 
+			var_ref_idx = find_var_ref_idx(hist_data, var_ref);
+			if (WARN_ON(var_ref_idx < 0)) {
+				ret = var_ref_idx;
+				goto err;
+			}
+
+			data->var_ref_idx[i] = var_ref_idx;
+
 			field_pos++;
 			kfree(p);
 			continue;
@@ -4323,7 +5185,6 @@ static int trace_action_create(struct hist_trigger_data *hist_data,
 	}
 
 	data->synth_event = event;
-	data->var_ref_idx = var_ref_idx;
  out:
 	return ret;
  err:
@@ -4542,10 +5403,6 @@ static int create_val_fields(struct hist_trigger_data *hist_data,
 	if (!fields_str)
 		goto out;
 
-	strsep(&fields_str, "=");
-	if (!fields_str)
-		goto out;
-
 	for (i = 0, j = 1; i < TRACING_MAP_VALS_MAX &&
 		     j < TRACING_MAP_VALS_MAX; i++) {
 		field_str = strsep(&fields_str, ",");
@@ -4640,10 +5497,6 @@ static int create_key_fields(struct hist_trigger_data *hist_data,
 	if (!fields_str)
 		goto out;
 
-	strsep(&fields_str, "=");
-	if (!fields_str)
-		goto out;
-
 	for (i = n_vals; i < n_vals + TRACING_MAP_KEYS_MAX; i++) {
 		field_str = strsep(&fields_str, ",");
 		if (!field_str)
@@ -4775,7 +5628,7 @@ static int create_hist_fields(struct hist_trigger_data *hist_data,
 	return ret;
 }
 
-static int is_descending(const char *str)
+static int is_descending(struct trace_array *tr, const char *str)
 {
 	if (!str)
 		return 0;
@@ -4786,11 +5639,14 @@ static int is_descending(const char *str)
 	if (strcmp(str, "ascending") == 0)
 		return 0;
 
+	hist_err(tr, HIST_ERR_INVALID_SORT_MODIFIER, errpos((char *)str));
+
 	return -EINVAL;
 }
 
 static int create_sort_keys(struct hist_trigger_data *hist_data)
 {
+	struct trace_array *tr = hist_data->event_file->tr;
 	char *fields_str = hist_data->attrs->sort_key_str;
 	struct tracing_map_sort_key *sort_key;
 	int descending, ret = 0;
@@ -4801,12 +5657,6 @@ static int create_sort_keys(struct hist_trigger_data *hist_data)
 	if (!fields_str)
 		goto out;
 
-	strsep(&fields_str, "=");
-	if (!fields_str) {
-		ret = -EINVAL;
-		goto out;
-	}
-
 	for (i = 0; i < TRACING_MAP_SORT_KEYS_MAX; i++) {
 		struct hist_field *hist_field;
 		char *field_str, *field_name;
@@ -4815,25 +5665,30 @@ static int create_sort_keys(struct hist_trigger_data *hist_data)
 		sort_key = &hist_data->sort_keys[i];
 
 		field_str = strsep(&fields_str, ",");
-		if (!field_str) {
-			if (i == 0)
-				ret = -EINVAL;
+		if (!field_str)
+			break;
+
+		if (!*field_str) {
+			ret = -EINVAL;
+			hist_err(tr, HIST_ERR_EMPTY_SORT_FIELD, errpos("sort="));
 			break;
 		}
 
 		if ((i == TRACING_MAP_SORT_KEYS_MAX - 1) && fields_str) {
+			hist_err(tr, HIST_ERR_TOO_MANY_SORT_FIELDS, errpos("sort="));
 			ret = -EINVAL;
 			break;
 		}
 
 		field_name = strsep(&field_str, ".");
-		if (!field_name) {
+		if (!field_name || !*field_name) {
 			ret = -EINVAL;
+			hist_err(tr, HIST_ERR_EMPTY_SORT_FIELD, errpos("sort="));
 			break;
 		}
 
 		if (strcmp(field_name, "hitcount") == 0) {
-			descending = is_descending(field_str);
+			descending = is_descending(tr, field_str);
 			if (descending < 0) {
 				ret = descending;
 				break;
@@ -4855,7 +5710,7 @@ static int create_sort_keys(struct hist_trigger_data *hist_data)
 
 			if (strcmp(field_name, test_name) == 0) {
 				sort_key->field_idx = idx;
-				descending = is_descending(field_str);
+				descending = is_descending(tr, field_str);
 				if (descending < 0) {
 					ret = descending;
 					goto out;
@@ -4866,6 +5721,7 @@ static int create_sort_keys(struct hist_trigger_data *hist_data)
 		}
 		if (j == hist_data->n_fields) {
 			ret = -EINVAL;
+			hist_err(tr, HIST_ERR_INVALID_SORT_FIELD, errpos(field_name));
 			break;
 		}
 	}
diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c
index 40106fff06a4..dd34a1b46a86 100644
--- a/kernel/trace/trace_events_trigger.c
+++ b/kernel/trace/trace_events_trigger.c
@@ -116,9 +116,10 @@ static void *trigger_next(struct seq_file *m, void *t, loff_t *pos)
 {
 	struct trace_event_file *event_file = event_file_data(m->private);
 
-	if (t == SHOW_AVAILABLE_TRIGGERS)
+	if (t == SHOW_AVAILABLE_TRIGGERS) {
+		(*pos)++;
 		return NULL;
-
+	}
 	return seq_list_next(t, &event_file->triggers, pos);
 }
 
@@ -213,7 +214,7 @@ static int event_trigger_regex_open(struct inode *inode, struct file *file)
 	return ret;
 }
 
-static int trigger_process_regex(struct trace_event_file *file, char *buff)
+int trigger_process_regex(struct trace_event_file *file, char *buff)
 {
 	char *command, *next = buff;
 	struct event_command *p;
diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c
index b611cd36e22d..8a4c8d5c2c98 100644
--- a/kernel/trace/trace_functions.c
+++ b/kernel/trace/trace_functions.c
@@ -101,7 +101,7 @@ static int function_trace_init(struct trace_array *tr)
 
 	ftrace_init_array_ops(tr, func);
 
-	tr->trace_buffer.cpu = get_cpu();
+	tr->array_buffer.cpu = get_cpu();
 	put_cpu();
 
 	tracing_start_cmdline_record();
@@ -118,7 +118,7 @@ static void function_trace_reset(struct trace_array *tr)
 
 static void function_trace_start(struct trace_array *tr)
 {
-	tracing_reset_online_cpus(&tr->trace_buffer);
+	tracing_reset_online_cpus(&tr->array_buffer);
 }
 
 static void
@@ -143,7 +143,7 @@ function_trace_call(unsigned long ip, unsigned long parent_ip,
 		goto out;
 
 	cpu = smp_processor_id();
-	data = per_cpu_ptr(tr->trace_buffer.data, cpu);
+	data = per_cpu_ptr(tr->array_buffer.data, cpu);
 	if (!atomic_read(&data->disabled)) {
 		local_save_flags(flags);
 		trace_function(tr, ip, parent_ip, flags, pc);
@@ -192,7 +192,7 @@ function_stack_trace_call(unsigned long ip, unsigned long parent_ip,
 	 */
 	local_irq_save(flags);
 	cpu = raw_smp_processor_id();
-	data = per_cpu_ptr(tr->trace_buffer.data, cpu);
+	data = per_cpu_ptr(tr->array_buffer.data, cpu);
 	disabled = atomic_inc_return(&data->disabled);
 
 	if (likely(disabled == 1)) {
diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
index 78af97163147..7d71546ba00a 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -101,7 +101,7 @@ int __trace_graph_entry(struct trace_array *tr,
 {
 	struct trace_event_call *call = &event_funcgraph_entry;
 	struct ring_buffer_event *event;
-	struct ring_buffer *buffer = tr->trace_buffer.buffer;
+	struct trace_buffer *buffer = tr->array_buffer.buffer;
 	struct ftrace_graph_ent_entry *entry;
 
 	event = trace_buffer_lock_reserve(buffer, TRACE_GRAPH_ENT,
@@ -171,7 +171,7 @@ int trace_graph_entry(struct ftrace_graph_ent *trace)
 
 	local_irq_save(flags);
 	cpu = raw_smp_processor_id();
-	data = per_cpu_ptr(tr->trace_buffer.data, cpu);
+	data = per_cpu_ptr(tr->array_buffer.data, cpu);
 	disabled = atomic_inc_return(&data->disabled);
 	if (likely(disabled == 1)) {
 		pc = preempt_count();
@@ -221,7 +221,7 @@ void __trace_graph_return(struct trace_array *tr,
 {
 	struct trace_event_call *call = &event_funcgraph_exit;
 	struct ring_buffer_event *event;
-	struct ring_buffer *buffer = tr->trace_buffer.buffer;
+	struct trace_buffer *buffer = tr->array_buffer.buffer;
 	struct ftrace_graph_ret_entry *entry;
 
 	event = trace_buffer_lock_reserve(buffer, TRACE_GRAPH_RET,
@@ -252,7 +252,7 @@ void trace_graph_return(struct ftrace_graph_ret *trace)
 
 	local_irq_save(flags);
 	cpu = raw_smp_processor_id();
-	data = per_cpu_ptr(tr->trace_buffer.data, cpu);
+	data = per_cpu_ptr(tr->array_buffer.data, cpu);
 	disabled = atomic_inc_return(&data->disabled);
 	if (likely(disabled == 1)) {
 		pc = preempt_count();
@@ -444,9 +444,9 @@ get_return_for_leaf(struct trace_iterator *iter,
 			 * We need to consume the current entry to see
 			 * the next one.
 			 */
-			ring_buffer_consume(iter->trace_buffer->buffer, iter->cpu,
+			ring_buffer_consume(iter->array_buffer->buffer, iter->cpu,
 					    NULL, NULL);
-			event = ring_buffer_peek(iter->trace_buffer->buffer, iter->cpu,
+			event = ring_buffer_peek(iter->array_buffer->buffer, iter->cpu,
 						 NULL, NULL);
 		}
 
@@ -503,7 +503,7 @@ print_graph_rel_time(struct trace_iterator *iter, struct trace_seq *s)
 {
 	unsigned long long usecs;
 
-	usecs = iter->ts - iter->trace_buffer->time_start;
+	usecs = iter->ts - iter->array_buffer->time_start;
 	do_div(usecs, NSEC_PER_USEC);
 
 	trace_seq_printf(s, "%9llu us |  ", usecs);
diff --git a/kernel/trace/trace_hwlat.c b/kernel/trace/trace_hwlat.c
index 402d022d0229..a48808c43249 100644
--- a/kernel/trace/trace_hwlat.c
+++ b/kernel/trace/trace_hwlat.c
@@ -104,7 +104,7 @@ static void trace_hwlat_sample(struct hwlat_sample *sample)
 {
 	struct trace_array *tr = hwlat_trace;
 	struct trace_event_call *call = &event_hwlat;
-	struct ring_buffer *buffer = tr->trace_buffer.buffer;
+	struct trace_buffer *buffer = tr->array_buffer.buffer;
 	struct ring_buffer_event *event;
 	struct hwlat_entry *entry;
 	unsigned long flags;
diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c
index a745b0cee5d3..10bbb0f381d5 100644
--- a/kernel/trace/trace_irqsoff.c
+++ b/kernel/trace/trace_irqsoff.c
@@ -122,7 +122,7 @@ static int func_prolog_dec(struct trace_array *tr,
 	if (!irqs_disabled_flags(*flags) && !preempt_count())
 		return 0;
 
-	*data = per_cpu_ptr(tr->trace_buffer.data, cpu);
+	*data = per_cpu_ptr(tr->array_buffer.data, cpu);
 	disabled = atomic_inc_return(&(*data)->disabled);
 
 	if (likely(disabled == 1))
@@ -167,7 +167,7 @@ static int irqsoff_display_graph(struct trace_array *tr, int set)
 		per_cpu(tracing_cpu, cpu) = 0;
 
 	tr->max_latency = 0;
-	tracing_reset_online_cpus(&irqsoff_trace->trace_buffer);
+	tracing_reset_online_cpus(&irqsoff_trace->array_buffer);
 
 	return start_irqsoff_tracer(irqsoff_trace, set);
 }
@@ -382,7 +382,7 @@ start_critical_timing(unsigned long ip, unsigned long parent_ip, int pc)
 	if (per_cpu(tracing_cpu, cpu))
 		return;
 
-	data = per_cpu_ptr(tr->trace_buffer.data, cpu);
+	data = per_cpu_ptr(tr->array_buffer.data, cpu);
 
 	if (unlikely(!data) || atomic_read(&data->disabled))
 		return;
@@ -420,7 +420,7 @@ stop_critical_timing(unsigned long ip, unsigned long parent_ip, int pc)
 	if (!tracer_enabled || !tracing_is_enabled())
 		return;
 
-	data = per_cpu_ptr(tr->trace_buffer.data, cpu);
+	data = per_cpu_ptr(tr->array_buffer.data, cpu);
 
 	if (unlikely(!data) ||
 	    !data->critical_start || atomic_read(&data->disabled))
diff --git a/kernel/trace/trace_kdb.c b/kernel/trace/trace_kdb.c
index cca65044c14c..9da76104f7a2 100644
--- a/kernel/trace/trace_kdb.c
+++ b/kernel/trace/trace_kdb.c
@@ -43,7 +43,7 @@ static void ftrace_dump_buf(int skip_entries, long cpu_file)
 	if (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_ATOMIC);
 			ring_buffer_read_start(iter.buffer_iter[cpu]);
 			tracing_iter_reset(&iter, cpu);
@@ -51,7 +51,7 @@ static void ftrace_dump_buf(int skip_entries, long cpu_file)
 	} else {
 		iter.cpu_file = cpu_file;
 		iter.buffer_iter[cpu_file] =
-			ring_buffer_read_prepare(iter.trace_buffer->buffer,
+			ring_buffer_read_prepare(iter.array_buffer->buffer,
 						 cpu_file, GFP_ATOMIC);
 		ring_buffer_read_start(iter.buffer_iter[cpu_file]);
 		tracing_iter_reset(&iter, cpu_file);
@@ -124,7 +124,7 @@ static int kdb_ftdump(int argc, const char **argv)
 	iter.buffer_iter = buffer_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);
 	}
 
 	/* A negative skip_entries means skip all but the last entries */
@@ -139,7 +139,7 @@ static int kdb_ftdump(int argc, const char **argv)
 	ftrace_dump_buf(skip_entries, cpu_file);
 
 	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);
 	}
 
 	kdb_trap_printk--;
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index aa515d578c5b..d8264ebb9581 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -22,7 +22,6 @@
 
 #define KPROBE_EVENT_SYSTEM "kprobes"
 #define KRETPROBE_MAXACTIVE_MAX 4096
-#define MAX_KPROBE_CMDLINE_SIZE 1024
 
 /* Kprobe early definition from command line */
 static char kprobe_boot_events_buf[COMMAND_LINE_SIZE] __initdata;
@@ -902,6 +901,167 @@ static int create_or_delete_trace_kprobe(int argc, char **argv)
 	return ret == -ECANCELED ? -EINVAL : ret;
 }
 
+static int trace_kprobe_run_command(struct dynevent_cmd *cmd)
+{
+	return trace_run_command(cmd->seq.buffer, create_or_delete_trace_kprobe);
+}
+
+/**
+ * kprobe_event_cmd_init - Initialize a kprobe event command object
+ * @cmd: A pointer to the dynevent_cmd struct representing the new event
+ * @buf: A pointer to the buffer used to build the command
+ * @maxlen: The length of the buffer passed in @buf
+ *
+ * Initialize a synthetic event command object.  Use this before
+ * calling any of the other kprobe_event functions.
+ */
+void kprobe_event_cmd_init(struct dynevent_cmd *cmd, char *buf, int maxlen)
+{
+	dynevent_cmd_init(cmd, buf, maxlen, DYNEVENT_TYPE_KPROBE,
+			  trace_kprobe_run_command);
+}
+EXPORT_SYMBOL_GPL(kprobe_event_cmd_init);
+
+/**
+ * __kprobe_event_gen_cmd_start - Generate a kprobe event command from arg list
+ * @cmd: A pointer to the dynevent_cmd struct representing the new event
+ * @name: The name of the kprobe event
+ * @loc: The location of the kprobe event
+ * @kretprobe: Is this a return probe?
+ * @args: Variable number of arg (pairs), one pair for each field
+ *
+ * NOTE: Users normally won't want to call this function directly, but
+ * rather use the kprobe_event_gen_cmd_start() wrapper, which automatically
+ * adds a NULL to the end of the arg list.  If this function is used
+ * directly, make sure the last arg in the variable arg list is NULL.
+ *
+ * Generate a kprobe event command to be executed by
+ * kprobe_event_gen_cmd_end().  This function can be used to generate the
+ * complete command or only the first part of it; in the latter case,
+ * kprobe_event_add_fields() can be used to add more fields following this.
+ *
+ * Return: 0 if successful, error otherwise.
+ */
+int __kprobe_event_gen_cmd_start(struct dynevent_cmd *cmd, bool kretprobe,
+				 const char *name, const char *loc, ...)
+{
+	char buf[MAX_EVENT_NAME_LEN];
+	struct dynevent_arg arg;
+	va_list args;
+	int ret;
+
+	if (cmd->type != DYNEVENT_TYPE_KPROBE)
+		return -EINVAL;
+
+	if (kretprobe)
+		snprintf(buf, MAX_EVENT_NAME_LEN, "r:kprobes/%s", name);
+	else
+		snprintf(buf, MAX_EVENT_NAME_LEN, "p:kprobes/%s", name);
+
+	ret = dynevent_str_add(cmd, buf);
+	if (ret)
+		return ret;
+
+	dynevent_arg_init(&arg, 0);
+	arg.str = loc;
+	ret = dynevent_arg_add(cmd, &arg, NULL);
+	if (ret)
+		return ret;
+
+	va_start(args, loc);
+	for (;;) {
+		const char *field;
+
+		field = va_arg(args, const char *);
+		if (!field)
+			break;
+
+		if (++cmd->n_fields > MAX_TRACE_ARGS) {
+			ret = -EINVAL;
+			break;
+		}
+
+		arg.str = field;
+		ret = dynevent_arg_add(cmd, &arg, NULL);
+		if (ret)
+			break;
+	}
+	va_end(args);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(__kprobe_event_gen_cmd_start);
+
+/**
+ * __kprobe_event_add_fields - Add probe fields to a kprobe command from arg list
+ * @cmd: A pointer to the dynevent_cmd struct representing the new event
+ * @args: Variable number of arg (pairs), one pair for each field
+ *
+ * NOTE: Users normally won't want to call this function directly, but
+ * rather use the kprobe_event_add_fields() wrapper, which
+ * automatically adds a NULL to the end of the arg list.  If this
+ * function is used directly, make sure the last arg in the variable
+ * arg list is NULL.
+ *
+ * Add probe fields to an existing kprobe command using a variable
+ * list of args.  Fields are added in the same order they're listed.
+ *
+ * Return: 0 if successful, error otherwise.
+ */
+int __kprobe_event_add_fields(struct dynevent_cmd *cmd, ...)
+{
+	struct dynevent_arg arg;
+	va_list args;
+	int ret;
+
+	if (cmd->type != DYNEVENT_TYPE_KPROBE)
+		return -EINVAL;
+
+	dynevent_arg_init(&arg, 0);
+
+	va_start(args, cmd);
+	for (;;) {
+		const char *field;
+
+		field = va_arg(args, const char *);
+		if (!field)
+			break;
+
+		if (++cmd->n_fields > MAX_TRACE_ARGS) {
+			ret = -EINVAL;
+			break;
+		}
+
+		arg.str = field;
+		ret = dynevent_arg_add(cmd, &arg, NULL);
+		if (ret)
+			break;
+	}
+	va_end(args);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(__kprobe_event_add_fields);
+
+/**
+ * kprobe_event_delete - Delete a kprobe event
+ * @name: The name of the kprobe event to delete
+ *
+ * Delete a kprobe event with the give @name from kernel code rather
+ * than directly from the command line.
+ *
+ * Return: 0 if successful, error otherwise.
+ */
+int kprobe_event_delete(const char *name)
+{
+	char buf[MAX_EVENT_NAME_LEN];
+
+	snprintf(buf, MAX_EVENT_NAME_LEN, "-:%s", name);
+
+	return trace_run_command(buf, create_or_delete_trace_kprobe);
+}
+EXPORT_SYMBOL_GPL(kprobe_event_delete);
+
 static int trace_kprobe_release(struct dyn_event *ev)
 {
 	struct trace_kprobe *tk = to_trace_kprobe(ev);
@@ -1175,35 +1335,35 @@ __kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs,
 		    struct trace_event_file *trace_file)
 {
 	struct kprobe_trace_entry_head *entry;
-	struct ring_buffer_event *event;
-	struct ring_buffer *buffer;
-	int size, dsize, pc;
-	unsigned long irq_flags;
 	struct trace_event_call *call = trace_probe_event_call(&tk->tp);
+	struct trace_event_buffer fbuffer;
+	int dsize;
 
 	WARN_ON(call != trace_file->event_call);
 
 	if (trace_trigger_soft_disabled(trace_file))
 		return;
 
-	local_save_flags(irq_flags);
-	pc = preempt_count();
+	local_save_flags(fbuffer.flags);
+	fbuffer.pc = preempt_count();
+	fbuffer.trace_file = trace_file;
 
 	dsize = __get_data_size(&tk->tp, regs);
-	size = sizeof(*entry) + tk->tp.size + dsize;
 
-	event = trace_event_buffer_lock_reserve(&buffer, trace_file,
-						call->event.type,
-						size, irq_flags, pc);
-	if (!event)
+	fbuffer.event =
+		trace_event_buffer_lock_reserve(&fbuffer.buffer, trace_file,
+					call->event.type,
+					sizeof(*entry) + tk->tp.size + dsize,
+					fbuffer.flags, fbuffer.pc);
+	if (!fbuffer.event)
 		return;
 
-	entry = ring_buffer_event_data(event);
+	fbuffer.regs = regs;
+	entry = fbuffer.entry = ring_buffer_event_data(fbuffer.event);
 	entry->ip = (unsigned long)tk->rp.kp.addr;
 	store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);
 
-	event_trigger_unlock_commit_regs(trace_file, buffer, event,
-					 entry, irq_flags, pc, regs);
+	trace_event_buffer_commit(&fbuffer);
 }
 
 static void
@@ -1223,36 +1383,35 @@ __kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
 		       struct trace_event_file *trace_file)
 {
 	struct kretprobe_trace_entry_head *entry;
-	struct ring_buffer_event *event;
-	struct ring_buffer *buffer;
-	int size, pc, dsize;
-	unsigned long irq_flags;
+	struct trace_event_buffer fbuffer;
 	struct trace_event_call *call = trace_probe_event_call(&tk->tp);
+	int dsize;
 
 	WARN_ON(call != trace_file->event_call);
 
 	if (trace_trigger_soft_disabled(trace_file))
 		return;
 
-	local_save_flags(irq_flags);
-	pc = preempt_count();
+	local_save_flags(fbuffer.flags);
+	fbuffer.pc = preempt_count();
+	fbuffer.trace_file = trace_file;
 
 	dsize = __get_data_size(&tk->tp, regs);
-	size = sizeof(*entry) + tk->tp.size + dsize;
-
-	event = trace_event_buffer_lock_reserve(&buffer, trace_file,
-						call->event.type,
-						size, irq_flags, pc);
-	if (!event)
+	fbuffer.event =
+		trace_event_buffer_lock_reserve(&fbuffer.buffer, trace_file,
+					call->event.type,
+					sizeof(*entry) + tk->tp.size + dsize,
+					fbuffer.flags, fbuffer.pc);
+	if (!fbuffer.event)
 		return;
 
-	entry = ring_buffer_event_data(event);
+	fbuffer.regs = regs;
+	entry = fbuffer.entry = ring_buffer_event_data(fbuffer.event);
 	entry->func = (unsigned long)tk->rp.kp.addr;
 	entry->ret_ip = (unsigned long)ri->ret_addr;
 	store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);
 
-	event_trigger_unlock_commit_regs(trace_file, buffer, event,
-					 entry, irq_flags, pc, regs);
+	trace_event_buffer_commit(&fbuffer);
 }
 
 static void
@@ -1698,11 +1857,12 @@ static __init void setup_boot_kprobe_events(void)
 	enable_boot_kprobe_events();
 }
 
-/* Make a tracefs interface for controlling probe points */
-static __init int init_kprobe_trace(void)
+/*
+ * Register dynevent at subsys_initcall. This allows kernel to setup kprobe
+ * events in fs_initcall without tracefs.
+ */
+static __init int init_kprobe_trace_early(void)
 {
-	struct dentry *d_tracer;
-	struct dentry *entry;
 	int ret;
 
 	ret = dyn_event_register(&trace_kprobe_ops);
@@ -1712,6 +1872,16 @@ static __init int init_kprobe_trace(void)
 	if (register_module_notifier(&trace_kprobe_module_nb))
 		return -EINVAL;
 
+	return 0;
+}
+subsys_initcall(init_kprobe_trace_early);
+
+/* Make a tracefs interface for controlling probe points */
+static __init int init_kprobe_trace(void)
+{
+	struct dentry *d_tracer;
+	struct dentry *entry;
+
 	d_tracer = tracing_init_dentry();
 	if (IS_ERR(d_tracer))
 		return 0;
diff --git a/kernel/trace/trace_mmiotrace.c b/kernel/trace/trace_mmiotrace.c
index b0388016b687..84582bf1ed5f 100644
--- a/kernel/trace/trace_mmiotrace.c
+++ b/kernel/trace/trace_mmiotrace.c
@@ -32,7 +32,7 @@ static void mmio_reset_data(struct trace_array *tr)
 	overrun_detected = false;
 	prev_overruns = 0;
 
-	tracing_reset_online_cpus(&tr->trace_buffer);
+	tracing_reset_online_cpus(&tr->array_buffer);
 }
 
 static int mmio_trace_init(struct trace_array *tr)
@@ -122,7 +122,7 @@ static void mmio_close(struct trace_iterator *iter)
 static unsigned long count_overruns(struct trace_iterator *iter)
 {
 	unsigned long cnt = atomic_xchg(&dropped_count, 0);
-	unsigned long over = ring_buffer_overruns(iter->trace_buffer->buffer);
+	unsigned long over = ring_buffer_overruns(iter->array_buffer->buffer);
 
 	if (over > prev_overruns)
 		cnt += over - prev_overruns;
@@ -297,7 +297,7 @@ static void __trace_mmiotrace_rw(struct trace_array *tr,
 				struct mmiotrace_rw *rw)
 {
 	struct trace_event_call *call = &event_mmiotrace_rw;
-	struct ring_buffer *buffer = tr->trace_buffer.buffer;
+	struct trace_buffer *buffer = tr->array_buffer.buffer;
 	struct ring_buffer_event *event;
 	struct trace_mmiotrace_rw *entry;
 	int pc = preempt_count();
@@ -318,7 +318,7 @@ static void __trace_mmiotrace_rw(struct trace_array *tr,
 void mmio_trace_rw(struct mmiotrace_rw *rw)
 {
 	struct trace_array *tr = mmio_trace_array;
-	struct trace_array_cpu *data = per_cpu_ptr(tr->trace_buffer.data, smp_processor_id());
+	struct trace_array_cpu *data = per_cpu_ptr(tr->array_buffer.data, smp_processor_id());
 	__trace_mmiotrace_rw(tr, data, rw);
 }
 
@@ -327,7 +327,7 @@ static void __trace_mmiotrace_map(struct trace_array *tr,
 				struct mmiotrace_map *map)
 {
 	struct trace_event_call *call = &event_mmiotrace_map;
-	struct ring_buffer *buffer = tr->trace_buffer.buffer;
+	struct trace_buffer *buffer = tr->array_buffer.buffer;
 	struct ring_buffer_event *event;
 	struct trace_mmiotrace_map *entry;
 	int pc = preempt_count();
@@ -351,7 +351,7 @@ void mmio_trace_mapping(struct mmiotrace_map *map)
 	struct trace_array_cpu *data;
 
 	preempt_disable();
-	data = per_cpu_ptr(tr->trace_buffer.data, smp_processor_id());
+	data = per_cpu_ptr(tr->array_buffer.data, smp_processor_id());
 	__trace_mmiotrace_map(tr, data, map);
 	preempt_enable();
 }
diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index d9b4b7c22db4..b4909082f6a4 100644
--- a/kernel/trace/trace_output.c
+++ b/kernel/trace/trace_output.c
@@ -538,7 +538,7 @@ lat_print_timestamp(struct trace_iterator *iter, u64 next_ts)
 	struct trace_array *tr = iter->tr;
 	unsigned long verbose = tr->trace_flags & TRACE_ITER_VERBOSE;
 	unsigned long in_ns = iter->iter_flags & TRACE_FILE_TIME_IN_NS;
-	unsigned long long abs_ts = iter->ts - iter->trace_buffer->time_start;
+	unsigned long long abs_ts = iter->ts - iter->array_buffer->time_start;
 	unsigned long long rel_ts = next_ts - iter->ts;
 	struct trace_seq *s = &iter->seq;
 
diff --git a/kernel/trace/trace_sched_switch.c b/kernel/trace/trace_sched_switch.c
index e288168661e1..e304196d7c28 100644
--- a/kernel/trace/trace_sched_switch.c
+++ b/kernel/trace/trace_sched_switch.c
@@ -89,8 +89,10 @@ static void tracing_sched_unregister(void)
 
 static void tracing_start_sched_switch(int ops)
 {
-	bool sched_register = (!sched_cmdline_ref && !sched_tgid_ref);
+	bool sched_register;
+
 	mutex_lock(&sched_register_mutex);
+	sched_register = (!sched_cmdline_ref && !sched_tgid_ref);
 
 	switch (ops) {
 	case RECORD_CMDLINE:
diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c
index 617e297f46dc..97b10bb31a1f 100644
--- a/kernel/trace/trace_sched_wakeup.c
+++ b/kernel/trace/trace_sched_wakeup.c
@@ -82,7 +82,7 @@ func_prolog_preempt_disable(struct trace_array *tr,
 	if (cpu != wakeup_current_cpu)
 		goto out_enable;
 
-	*data = per_cpu_ptr(tr->trace_buffer.data, cpu);
+	*data = per_cpu_ptr(tr->array_buffer.data, cpu);
 	disabled = atomic_inc_return(&(*data)->disabled);
 	if (unlikely(disabled != 1))
 		goto out;
@@ -378,7 +378,7 @@ tracing_sched_switch_trace(struct trace_array *tr,
 			   unsigned long flags, int pc)
 {
 	struct trace_event_call *call = &event_context_switch;
-	struct ring_buffer *buffer = tr->trace_buffer.buffer;
+	struct trace_buffer *buffer = tr->array_buffer.buffer;
 	struct ring_buffer_event *event;
 	struct ctx_switch_entry *entry;
 
@@ -408,7 +408,7 @@ tracing_sched_wakeup_trace(struct trace_array *tr,
 	struct trace_event_call *call = &event_wakeup;
 	struct ring_buffer_event *event;
 	struct ctx_switch_entry *entry;
-	struct ring_buffer *buffer = tr->trace_buffer.buffer;
+	struct trace_buffer *buffer = tr->array_buffer.buffer;
 
 	event = trace_buffer_lock_reserve(buffer, TRACE_WAKE,
 					  sizeof(*entry), flags, pc);
@@ -459,7 +459,7 @@ probe_wakeup_sched_switch(void *ignore, bool preempt,
 
 	/* disable local data, not wakeup_cpu data */
 	cpu = raw_smp_processor_id();
-	disabled = atomic_inc_return(&per_cpu_ptr(wakeup_trace->trace_buffer.data, cpu)->disabled);
+	disabled = atomic_inc_return(&per_cpu_ptr(wakeup_trace->array_buffer.data, cpu)->disabled);
 	if (likely(disabled != 1))
 		goto out;
 
@@ -471,7 +471,7 @@ probe_wakeup_sched_switch(void *ignore, bool preempt,
 		goto out_unlock;
 
 	/* The task we are waiting for is waking up */
-	data = per_cpu_ptr(wakeup_trace->trace_buffer.data, wakeup_cpu);
+	data = per_cpu_ptr(wakeup_trace->array_buffer.data, wakeup_cpu);
 
 	__trace_function(wakeup_trace, CALLER_ADDR0, CALLER_ADDR1, flags, pc);
 	tracing_sched_switch_trace(wakeup_trace, prev, next, flags, pc);
@@ -494,7 +494,7 @@ out_unlock:
 	arch_spin_unlock(&wakeup_lock);
 	local_irq_restore(flags);
 out:
-	atomic_dec(&per_cpu_ptr(wakeup_trace->trace_buffer.data, cpu)->disabled);
+	atomic_dec(&per_cpu_ptr(wakeup_trace->array_buffer.data, cpu)->disabled);
 }
 
 static void __wakeup_reset(struct trace_array *tr)
@@ -513,7 +513,7 @@ static void wakeup_reset(struct trace_array *tr)
 {
 	unsigned long flags;
 
-	tracing_reset_online_cpus(&tr->trace_buffer);
+	tracing_reset_online_cpus(&tr->array_buffer);
 
 	local_irq_save(flags);
 	arch_spin_lock(&wakeup_lock);
@@ -551,7 +551,7 @@ probe_wakeup(void *ignore, struct task_struct *p)
 		return;
 
 	pc = preempt_count();
-	disabled = atomic_inc_return(&per_cpu_ptr(wakeup_trace->trace_buffer.data, cpu)->disabled);
+	disabled = atomic_inc_return(&per_cpu_ptr(wakeup_trace->array_buffer.data, cpu)->disabled);
 	if (unlikely(disabled != 1))
 		goto out;
 
@@ -583,7 +583,7 @@ probe_wakeup(void *ignore, struct task_struct *p)
 
 	local_save_flags(flags);
 
-	data = per_cpu_ptr(wakeup_trace->trace_buffer.data, wakeup_cpu);
+	data = per_cpu_ptr(wakeup_trace->array_buffer.data, wakeup_cpu);
 	data->preempt_timestamp = ftrace_now(cpu);
 	tracing_sched_wakeup_trace(wakeup_trace, p, current, flags, pc);
 	__trace_stack(wakeup_trace, flags, 0, pc);
@@ -598,7 +598,7 @@ probe_wakeup(void *ignore, struct task_struct *p)
 out_locked:
 	arch_spin_unlock(&wakeup_lock);
 out:
-	atomic_dec(&per_cpu_ptr(wakeup_trace->trace_buffer.data, cpu)->disabled);
+	atomic_dec(&per_cpu_ptr(wakeup_trace->array_buffer.data, cpu)->disabled);
 }
 
 static void start_wakeup_tracer(struct trace_array *tr)
diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c
index 69ee8ef12cee..b5e3496cf803 100644
--- a/kernel/trace/trace_selftest.c
+++ b/kernel/trace/trace_selftest.c
@@ -23,7 +23,7 @@ static inline int trace_valid_entry(struct trace_entry *entry)
 	return 0;
 }
 
-static int trace_test_buffer_cpu(struct trace_buffer *buf, int cpu)
+static int trace_test_buffer_cpu(struct array_buffer *buf, int cpu)
 {
 	struct ring_buffer_event *event;
 	struct trace_entry *entry;
@@ -60,7 +60,7 @@ static int trace_test_buffer_cpu(struct trace_buffer *buf, int cpu)
  * Test the trace buffer to see if all the elements
  * are still sane.
  */
-static int __maybe_unused trace_test_buffer(struct trace_buffer *buf, unsigned long *count)
+static int __maybe_unused trace_test_buffer(struct array_buffer *buf, unsigned long *count)
 {
 	unsigned long flags, cnt = 0;
 	int cpu, ret = 0;
@@ -362,7 +362,7 @@ static int trace_selftest_startup_dynamic_tracing(struct tracer *trace,
 	msleep(100);
 
 	/* we should have nothing in the buffer */
-	ret = trace_test_buffer(&tr->trace_buffer, &count);
+	ret = trace_test_buffer(&tr->array_buffer, &count);
 	if (ret)
 		goto out;
 
@@ -383,7 +383,7 @@ static int trace_selftest_startup_dynamic_tracing(struct tracer *trace,
 	ftrace_enabled = 0;
 
 	/* check the trace buffer */
-	ret = trace_test_buffer(&tr->trace_buffer, &count);
+	ret = trace_test_buffer(&tr->array_buffer, &count);
 
 	ftrace_enabled = 1;
 	tracing_start();
@@ -682,7 +682,7 @@ trace_selftest_startup_function(struct tracer *trace, struct trace_array *tr)
 	ftrace_enabled = 0;
 
 	/* check the trace buffer */
-	ret = trace_test_buffer(&tr->trace_buffer, &count);
+	ret = trace_test_buffer(&tr->array_buffer, &count);
 
 	ftrace_enabled = 1;
 	trace->reset(tr);
@@ -768,7 +768,7 @@ trace_selftest_startup_function_graph(struct tracer *trace,
 	 * Simulate the init() callback but we attach a watchdog callback
 	 * to detect and recover from possible hangs
 	 */
-	tracing_reset_online_cpus(&tr->trace_buffer);
+	tracing_reset_online_cpus(&tr->array_buffer);
 	set_graph_array(tr);
 	ret = register_ftrace_graph(&fgraph_ops);
 	if (ret) {
@@ -790,7 +790,7 @@ trace_selftest_startup_function_graph(struct tracer *trace,
 	tracing_stop();
 
 	/* check the trace buffer */
-	ret = trace_test_buffer(&tr->trace_buffer, &count);
+	ret = trace_test_buffer(&tr->array_buffer, &count);
 
 	/* Need to also simulate the tr->reset to remove this fgraph_ops */
 	tracing_stop_cmdline_record();
@@ -848,7 +848,7 @@ trace_selftest_startup_irqsoff(struct tracer *trace, struct trace_array *tr)
 	/* stop the tracing. */
 	tracing_stop();
 	/* check both trace buffers */
-	ret = trace_test_buffer(&tr->trace_buffer, NULL);
+	ret = trace_test_buffer(&tr->array_buffer, NULL);
 	if (!ret)
 		ret = trace_test_buffer(&tr->max_buffer, &count);
 	trace->reset(tr);
@@ -910,7 +910,7 @@ trace_selftest_startup_preemptoff(struct tracer *trace, struct trace_array *tr)
 	/* stop the tracing. */
 	tracing_stop();
 	/* check both trace buffers */
-	ret = trace_test_buffer(&tr->trace_buffer, NULL);
+	ret = trace_test_buffer(&tr->array_buffer, NULL);
 	if (!ret)
 		ret = trace_test_buffer(&tr->max_buffer, &count);
 	trace->reset(tr);
@@ -976,7 +976,7 @@ trace_selftest_startup_preemptirqsoff(struct tracer *trace, struct trace_array *
 	/* stop the tracing. */
 	tracing_stop();
 	/* check both trace buffers */
-	ret = trace_test_buffer(&tr->trace_buffer, NULL);
+	ret = trace_test_buffer(&tr->array_buffer, NULL);
 	if (ret)
 		goto out;
 
@@ -1006,7 +1006,7 @@ trace_selftest_startup_preemptirqsoff(struct tracer *trace, struct trace_array *
 	/* stop the tracing. */
 	tracing_stop();
 	/* check both trace buffers */
-	ret = trace_test_buffer(&tr->trace_buffer, NULL);
+	ret = trace_test_buffer(&tr->array_buffer, NULL);
 	if (ret)
 		goto out;
 
@@ -1136,7 +1136,7 @@ trace_selftest_startup_wakeup(struct tracer *trace, struct trace_array *tr)
 	/* stop the tracing. */
 	tracing_stop();
 	/* check both trace buffers */
-	ret = trace_test_buffer(&tr->trace_buffer, NULL);
+	ret = trace_test_buffer(&tr->array_buffer, NULL);
 	if (!ret)
 		ret = trace_test_buffer(&tr->max_buffer, &count);
 
@@ -1177,7 +1177,7 @@ trace_selftest_startup_branch(struct tracer *trace, struct trace_array *tr)
 	/* stop the tracing. */
 	tracing_stop();
 	/* check the trace buffer */
-	ret = trace_test_buffer(&tr->trace_buffer, &count);
+	ret = trace_test_buffer(&tr->array_buffer, &count);
 	trace->reset(tr);
 	tracing_start();
 
diff --git a/kernel/trace/trace_seq.c b/kernel/trace/trace_seq.c
index 87de6edafd14..1d84fcc78e3e 100644
--- a/kernel/trace/trace_seq.c
+++ b/kernel/trace/trace_seq.c
@@ -30,9 +30,6 @@
 /* How much buffer is left on the trace_seq? */
 #define TRACE_SEQ_BUF_LEFT(s) seq_buf_buffer_left(&(s)->seq)
 
-/* How much buffer is written? */
-#define TRACE_SEQ_BUF_USED(s) seq_buf_used(&(s)->seq)
-
 /*
  * trace_seq should work with being initialized with 0s.
  */
diff --git a/kernel/trace/trace_stat.c b/kernel/trace/trace_stat.c
index 874f1274cf99..d1fa19773cc8 100644
--- a/kernel/trace/trace_stat.c
+++ b/kernel/trace/trace_stat.c
@@ -280,18 +280,22 @@ static int tracing_stat_init(void)
 
 	d_tracing = tracing_init_dentry();
 	if (IS_ERR(d_tracing))
-		return 0;
+		return -ENODEV;
 
 	stat_dir = tracefs_create_dir("trace_stat", d_tracing);
-	if (!stat_dir)
+	if (!stat_dir) {
 		pr_warn("Could not create tracefs 'trace_stat' entry\n");
+		return -ENOMEM;
+	}
 	return 0;
 }
 
 static int init_stat_file(struct stat_session *session)
 {
-	if (!stat_dir && tracing_stat_init())
-		return -ENODEV;
+	int ret;
+
+	if (!stat_dir && (ret = tracing_stat_init()))
+		return ret;
 
 	session->file = tracefs_create_file(session->ts->name, 0644,
 					    stat_dir,
@@ -304,7 +308,7 @@ static int init_stat_file(struct stat_session *session)
 int register_stat_tracer(struct tracer_stat *trace)
 {
 	struct stat_session *session, *node;
-	int ret;
+	int ret = -EINVAL;
 
 	if (!trace)
 		return -EINVAL;
@@ -315,17 +319,15 @@ int register_stat_tracer(struct tracer_stat *trace)
 	/* Already registered? */
 	mutex_lock(&all_stat_sessions_mutex);
 	list_for_each_entry(node, &all_stat_sessions, session_list) {
-		if (node->ts == trace) {
-			mutex_unlock(&all_stat_sessions_mutex);
-			return -EINVAL;
-		}
+		if (node->ts == trace)
+			goto out;
 	}
-	mutex_unlock(&all_stat_sessions_mutex);
 
+	ret = -ENOMEM;
 	/* Init the session */
 	session = kzalloc(sizeof(*session), GFP_KERNEL);
 	if (!session)
-		return -ENOMEM;
+		goto out;
 
 	session->ts = trace;
 	INIT_LIST_HEAD(&session->session_list);
@@ -334,15 +336,16 @@ int register_stat_tracer(struct tracer_stat *trace)
 	ret = init_stat_file(session);
 	if (ret) {
 		destroy_session(session);
-		return ret;
+		goto out;
 	}
 
+	ret = 0;
 	/* Register */
-	mutex_lock(&all_stat_sessions_mutex);
 	list_add_tail(&session->session_list, &all_stat_sessions);
+ out:
 	mutex_unlock(&all_stat_sessions_mutex);
 
-	return 0;
+	return ret;
 }
 
 void unregister_stat_tracer(struct tracer_stat *trace)
diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c
index 2978c29d87d4..d85a2f0f316b 100644
--- a/kernel/trace/trace_syscalls.c
+++ b/kernel/trace/trace_syscalls.c
@@ -297,7 +297,7 @@ static void ftrace_syscall_enter(void *data, struct pt_regs *regs, long id)
 	struct syscall_trace_enter *entry;
 	struct syscall_metadata *sys_data;
 	struct ring_buffer_event *event;
-	struct ring_buffer *buffer;
+	struct trace_buffer *buffer;
 	unsigned long irq_flags;
 	unsigned long args[6];
 	int pc;
@@ -325,7 +325,7 @@ static void ftrace_syscall_enter(void *data, struct pt_regs *regs, long id)
 	local_save_flags(irq_flags);
 	pc = preempt_count();
 
-	buffer = tr->trace_buffer.buffer;
+	buffer = tr->array_buffer.buffer;
 	event = trace_buffer_lock_reserve(buffer,
 			sys_data->enter_event->event.type, size, irq_flags, pc);
 	if (!event)
@@ -347,7 +347,7 @@ static void ftrace_syscall_exit(void *data, struct pt_regs *regs, long ret)
 	struct syscall_trace_exit *entry;
 	struct syscall_metadata *sys_data;
 	struct ring_buffer_event *event;
-	struct ring_buffer *buffer;
+	struct trace_buffer *buffer;
 	unsigned long irq_flags;
 	int pc;
 	int syscall_nr;
@@ -371,7 +371,7 @@ static void ftrace_syscall_exit(void *data, struct pt_regs *regs, long ret)
 	local_save_flags(irq_flags);
 	pc = preempt_count();
 
-	buffer = tr->trace_buffer.buffer;
+	buffer = tr->array_buffer.buffer;
 	event = trace_buffer_lock_reserve(buffer,
 			sys_data->exit_event->event.type, sizeof(*entry),
 			irq_flags, pc);
diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index 7885ebd23d0c..18d16f3ef980 100644
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -931,8 +931,8 @@ static void __uprobe_trace_func(struct trace_uprobe *tu,
 				struct trace_event_file *trace_file)
 {
 	struct uprobe_trace_entry_head *entry;
+	struct trace_buffer *buffer;
 	struct ring_buffer_event *event;
-	struct ring_buffer *buffer;
 	void *data;
 	int size, esize;
 	struct trace_event_call *call = trace_probe_event_call(&tu->tp);