Merge tag 'trace-v7.0' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull tracing updates from Steven Rostedt:
 "User visible changes:

   - Add an entry into MAINTAINERS file for RUST versions of code

     There's now RUST code for tracing and static branches. To
     differentiate that code from the C code, add entries in for the
     RUST version (with "[RUST]" around it) so that the right
     maintainers get notified on changes.

   - New bitmask-list option added to tracefs

     When this is set, bitmasks in trace event are not displayed as hex
     numbers, but instead as lists: e.g. 0-5,7,9 instead of 0000015f

   - New show_event_filters file in tracefs

     Instead of having to search all events/*/*/filter for any active
     filters enabled in the trace instance, the file show_event_filters
     will list them so that there's only one file that needs to be
     examined to see if any filters are active.

   - New show_event_triggers file in tracefs

     Instead of having to search all events/*/*/trigger for any active
     triggers enabled in the trace instance, the file
     show_event_triggers will list them so that there's only one file
     that needs to be examined to see if any triggers are active.

   - Have traceoff_on_warning disable trace pintk buffer too

     Recently recording of trace_printk() could go to other trace
     instances instead of the top level instance. But if
     traceoff_on_warning triggers, it doesn't stop the buffer with
     trace_printk() and that data can easily be lost by being
     overwritten. Have traceoff_on_warning also disable the instance
     that has trace_printk() being written to it.

   - Update the hist_debug file to show what function the field uses

     When CONFIG_HIST_TRIGGERS_DEBUG is enabled, a hist_debug file
     exists for every event. This displays the internal data of any
     histogram enabled for that event. But it is lacking the function
     that is called to process one of its fields. This is very useful
     information that was missing when debugging histograms.

   - Up the histogram stack size from 16 to 31

     Stack traces can be used as keys for event histograms. Currently
     the size of the stack that is stored is limited to just 16 entries.
     But the storage space in the histogram is 256 bytes, meaning that
     it can store up to 31 entries (plus one for the count of entries).
     Instead of letting that space go to waste, up the limit from 16 to
     31. This makes the keys much more useful.

   - Fix permissions of per CPU file buffer_size_kb

     The per CPU file of buffer_size_kb was incorrectly set to read only
     in a previous cleanup. It should be writable.

   - Reset "last_boot_info" if the persistent buffer is cleared

     The last_boot_info shows address information of a persistent ring
     buffer if it contains data from a previous boot. It is cleared when
     recording starts again, but it is not cleared when the buffer is
     reset. The data is useless after a reset so clear it on reset too.

  Internal changes:

   - A change was made to allow tracepoint callbacks to have preemption
     enabled, and instead be protected by SRCU. This required some
     updates to the callbacks for perf and BPF.

     perf needed to disable preemption directly in its callback because
     it expects preemption disabled in the later code.

     BPF needed to disable migration, as its code expects to run
     completely on the same CPU.

   - Have irq_work wake up other CPU if current CPU is "isolated"

     When there's a waiter waiting on ring buffer data and a new event
     happens, an irq work is triggered to wake up that waiter. This is
     noisy on isolated CPUs (running NO_HZ_FULL). Trigger an IPI to a
     house keeping CPU instead.

   - Use proper free of trigger_data instead of open coding it in.

   - Remove redundant call of event_trigger_reset_filter()

     It was called immediately in a function that was called right after
     it.

   - Workqueue cleanups

   - Report errors if tracing_update_buffers() were to fail.

   - Make the enum update workqueue generic for other parts of tracing

     On boot up, a work queue is created to convert enum names into
     their numbers in the trace event format files. This work queue can
     also be used for other aspects of tracing that takes some time and
     shouldn't be called by the init call code.

     The blk_trace initialization takes a bit of time. Have the
     initialization code moved to the new tracing generic work queue
     function.

   - Skip kprobe boot event creation call if there's no kprobes defined
     on cmdline

     The kprobe initialization to set up kprobes if they are defined on
     the cmdline requires taking the event_mutex lock. This can be held
     by other tracing code doing initialization for a long time. Since
     kprobes added to the kernel command line need to be setup
     immediately, as they may be tracing early initialization code, they
     cannot be postponed in a work queue and must be setup in the
     initcall code.

     If there's no kprobe on the kernel cmdline, there's no reason to
     take the mutex and slow down the boot up code waiting to get the
     lock only to find out there's nothing to do. Simply exit out early
     if there's no kprobes on the kernel cmdline.

     If there are kprobes on the cmdline, then someone cares more about
     tracing over the speed of boot up.

   - Clean up the trigger code a bit

   - Move code out of trace.c and into their own files

     trace.c is now over 11,000 lines of code and has become more
     difficult to maintain. Start splitting it up so that related code
     is in their own files.

     Move all the trace_printk() related code into trace_printk.c.

     Move the __always_inline stack functions into trace.h.

     Move the pid filtering code into a new trace_pid.c file.

   - Better define the max latency and snapshot code

     The latency tracers have a "max latency" buffer that is a copy of
     the main buffer and gets swapped with it when a new high latency is
     detected. This keeps the trace up to the highest latency around
     where this max_latency buffer is never written to. It is only used
     to save the last max latency trace.

     A while ago a snapshot feature was added to tracefs to allow user
     space to perform the same logic. It could also enable events to
     trigger a "snapshot" if one of their fields hit a new high. This
     was built on top of the latency max_latency buffer logic.

     Because snapshots came later, they were dependent on the latency
     tracers to be enabled. In reality, the latency tracers depend on
     the snapshot code and not the other way around. It was just that
     they came first.

     Restructure the code and the kconfigs to have the latency tracers
     depend on snapshot code instead. This actually simplifies the logic
     a bit and allows to disable more when the latency tracers are not
     defined and the snapshot code is.

   - Fix a "false sharing" in the hwlat tracer code

     The loop to search for latency in hardware was using a variable
     that could be changed by user space for each sample. If the user
     change this variable, it could cause a bus contention, and reading
     that variable can show up as a large latency in the trace causing a
     false positive. Read this variable at the start of the sample with
     a READ_ONCE() into a local variable and keep the code from sharing
     cache lines with readers.

   - Fix function graph tracer static branch optimization code

     When only one tracer is defined for function graph tracing, it uses
     a static branch to call that tracer directly. When another tracer
     is added, it goes into loop logic to call all the registered
     callbacks.

     The code was incorrect when going back to one tracer and never
     re-enabled the static branch again to do the optimization code.

   - And other small fixes and cleanups"

* tag 'trace-v7.0' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (46 commits)
  function_graph: Restore direct mode when callbacks drop to one
  tracing: Fix indentation of return statement in print_trace_fmt()
  tracing: Reset last_boot_info if ring buffer is reset
  tracing: Fix to set write permission to per-cpu buffer_size_kb
  tracing: Fix false sharing in hwlat get_sample()
  tracing: Move d_max_latency out of CONFIG_FSNOTIFY protection
  tracing: Better separate SNAPSHOT and MAX_TRACE options
  tracing: Add tracer_uses_snapshot() helper to remove #ifdefs
  tracing: Rename trace_array field max_buffer to snapshot_buffer
  tracing: Move pid filtering into trace_pid.c
  tracing: Move trace_printk functions out of trace.c and into trace_printk.c
  tracing: Use system_state in trace_printk_init_buffers()
  tracing: Have trace_printk functions use flags instead of using global_trace
  tracing: Make tracing_update_buffers() take NULL for global_trace
  tracing: Make printk_trace global for tracing system
  tracing: Move ftrace_trace_stack() out of trace.c and into trace.h
  tracing: Move __trace_buffer_{un}lock_*() functions to trace.h
  tracing: Make tracing_selftest_running global to the tracing subsystem
  tracing: Make tracing_disabled global for tracing system
  tracing: Clean up use of trace_create_maxlat_file()
  ...

21 files changed, 1306 insertions, 1053 deletions

diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index d7042a09fe46..49de13cae428 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -136,6 +136,7 @@ config BUILDTIME_MCOUNT_SORT
 
 config TRACER_MAX_TRACE
 	bool
+	select TRACER_SNAPSHOT
 
 config TRACE_CLOCK
 	bool
@@ -425,7 +426,6 @@ config IRQSOFF_TRACER
 	select GENERIC_TRACER
 	select TRACER_MAX_TRACE
 	select RING_BUFFER_ALLOW_SWAP
-	select TRACER_SNAPSHOT
 	select TRACER_SNAPSHOT_PER_CPU_SWAP
 	help
 	  This option measures the time spent in irqs-off critical
@@ -448,7 +448,6 @@ config PREEMPT_TRACER
 	select GENERIC_TRACER
 	select TRACER_MAX_TRACE
 	select RING_BUFFER_ALLOW_SWAP
-	select TRACER_SNAPSHOT
 	select TRACER_SNAPSHOT_PER_CPU_SWAP
 	select TRACE_PREEMPT_TOGGLE
 	help
@@ -470,7 +469,6 @@ config SCHED_TRACER
 	select GENERIC_TRACER
 	select CONTEXT_SWITCH_TRACER
 	select TRACER_MAX_TRACE
-	select TRACER_SNAPSHOT
 	help
 	  This tracer tracks the latency of the highest priority task
 	  to be scheduled in, starting from the point it has woken up.
@@ -620,7 +618,6 @@ config TRACE_SYSCALL_BUF_SIZE_DEFAULT
 
 config TRACER_SNAPSHOT
 	bool "Create a snapshot trace buffer"
-	select TRACER_MAX_TRACE
 	help
 	  Allow tracing users to take snapshot of the current buffer using the
 	  ftrace interface, e.g.:
@@ -628,6 +625,9 @@ config TRACER_SNAPSHOT
 	      echo 1 > /sys/kernel/tracing/snapshot
 	      cat snapshot
 
+	  Note, the latency tracers select this option. To disable it,
+	  all the latency tracers need to be disabled.
+
 config TRACER_SNAPSHOT_PER_CPU_SWAP
 	bool "Allow snapshot to swap per CPU"
 	depends on TRACER_SNAPSHOT
diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile
index fc5dcc888e13..04096c21d06b 100644
--- a/kernel/trace/Makefile
+++ b/kernel/trace/Makefile
@@ -68,6 +68,7 @@ obj-$(CONFIG_TRACING) += trace_output.o
 obj-$(CONFIG_TRACING) += trace_seq.o
 obj-$(CONFIG_TRACING) += trace_stat.o
 obj-$(CONFIG_TRACING) += trace_printk.o
+obj-$(CONFIG_TRACING) += trace_pid.o
 obj-$(CONFIG_TRACING) += 	pid_list.o
 obj-$(CONFIG_TRACING_MAP) += tracing_map.o
 obj-$(CONFIG_PREEMPTIRQ_DELAY_TEST) += preemptirq_delay_test.o
diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index c4db5c2e7103..f2de9cf15d0e 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -1832,7 +1832,9 @@ static struct trace_event trace_blk_event = {
 	.funcs		= &trace_blk_event_funcs,
 };
 
-static int __init init_blk_tracer(void)
+static struct work_struct blktrace_works __initdata;
+
+static int __init __init_blk_tracer(void)
 {
 	if (!register_trace_event(&trace_blk_event)) {
 		pr_warn("Warning: could not register block events\n");
@@ -1852,6 +1854,25 @@ static int __init init_blk_tracer(void)
 	return 0;
 }
 
+static void __init blktrace_works_func(struct work_struct *work)
+{
+	__init_blk_tracer();
+}
+
+static int __init init_blk_tracer(void)
+{
+	int ret = 0;
+
+	if (trace_init_wq) {
+		INIT_WORK(&blktrace_works, blktrace_works_func);
+		queue_work(trace_init_wq, &blktrace_works);
+	} else {
+		ret = __init_blk_tracer();
+	}
+
+	return ret;
+}
+
 device_initcall(init_blk_tracer);
 
 static int blk_trace_remove_queue(struct request_queue *q)
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index f7baeb8278ca..eadaef8592a3 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -2076,7 +2076,7 @@ void __bpf_trace_run(struct bpf_raw_tp_link *link, u64 *args)
 	struct bpf_run_ctx *old_run_ctx;
 	struct bpf_trace_run_ctx run_ctx;
 
-	cant_sleep();
+	rcu_read_lock_dont_migrate();
 	if (unlikely(!bpf_prog_get_recursion_context(prog))) {
 		bpf_prog_inc_misses_counter(prog);
 		goto out;
@@ -2085,13 +2085,12 @@ void __bpf_trace_run(struct bpf_raw_tp_link *link, u64 *args)
 	run_ctx.bpf_cookie = link->cookie;
 	old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx);
 
-	rcu_read_lock();
 	(void) bpf_prog_run(prog, args);
-	rcu_read_unlock();
 
 	bpf_reset_run_ctx(old_run_ctx);
 out:
 	bpf_prog_put_recursion_context(prog);
+	rcu_read_unlock_migrate();
 }
 
 #define UNPACK(...)			__VA_ARGS__
diff --git a/kernel/trace/fgraph.c b/kernel/trace/fgraph.c
index cc48d16be43e..4df766c690f9 100644
--- a/kernel/trace/fgraph.c
+++ b/kernel/trace/fgraph.c
@@ -1303,7 +1303,7 @@ static void ftrace_graph_enable_direct(bool enable_branch, struct fgraph_ops *go
 	static_call_update(fgraph_func, func);
 	static_call_update(fgraph_retfunc, retfunc);
 	if (enable_branch)
-		static_branch_disable(&fgraph_do_direct);
+		static_branch_enable(&fgraph_do_direct);
 }
 
 static void ftrace_graph_disable_direct(bool disable_branch)
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 8fb38722fd5c..1ce17c8af409 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -1147,6 +1147,7 @@ struct ftrace_page {
 };
 
 #define ENTRY_SIZE sizeof(struct dyn_ftrace)
+#define ENTRIES_PER_PAGE_GROUP(order) ((PAGE_SIZE << (order)) / ENTRY_SIZE)
 
 static struct ftrace_page	*ftrace_pages_start;
 static struct ftrace_page	*ftrace_pages;
@@ -3873,7 +3874,7 @@ static int ftrace_allocate_records(struct ftrace_page *pg, int count,
 	*num_pages += 1 << order;
 	ftrace_number_of_groups++;
 
-	cnt = (PAGE_SIZE << order) / ENTRY_SIZE;
+	cnt = ENTRIES_PER_PAGE_GROUP(order);
 	pg->order = order;
 
 	if (cnt > count)
@@ -7668,7 +7669,7 @@ static int ftrace_process_locs(struct module *mod,
 		long skip;
 
 		/* Count the number of entries unused and compare it to skipped. */
-		pg_remaining = (PAGE_SIZE << pg->order) / ENTRY_SIZE - pg->index;
+		pg_remaining = ENTRIES_PER_PAGE_GROUP(pg->order) - pg->index;
 
 		if (!WARN(skipped < pg_remaining, "Extra allocated pages for ftrace")) {
 
@@ -7676,7 +7677,7 @@ static int ftrace_process_locs(struct module *mod,
 
 			for (pg = pg_unuse; pg && skip > 0; pg = pg->next) {
 				remaining += 1 << pg->order;
-				skip -= (PAGE_SIZE << pg->order) / ENTRY_SIZE;
+				skip -= ENTRIES_PER_PAGE_GROUP(pg->order);
 			}
 
 			pages -= remaining;
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 630221b00838..d33103408955 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -4,6 +4,7 @@
  *
  * Copyright (C) 2008 Steven Rostedt <srostedt@redhat.com>
  */
+#include <linux/sched/isolation.h>
 #include <linux/trace_recursion.h>
 #include <linux/trace_events.h>
 #include <linux/ring_buffer.h>
@@ -4013,19 +4014,36 @@ static void rb_commit(struct ring_buffer_per_cpu *cpu_buffer)
 	rb_end_commit(cpu_buffer);
 }
 
+static bool
+rb_irq_work_queue(struct rb_irq_work *irq_work)
+{
+	int cpu;
+
+	/* irq_work_queue_on() is not NMI-safe */
+	if (unlikely(in_nmi()))
+		return irq_work_queue(&irq_work->work);
+
+	/*
+	 * If CPU isolation is not active, cpu is always the current
+	 * CPU, and the following is equivallent to irq_work_queue().
+	 */
+	cpu = housekeeping_any_cpu(HK_TYPE_KERNEL_NOISE);
+	return irq_work_queue_on(&irq_work->work, cpu);
+}
+
 static __always_inline void
 rb_wakeups(struct trace_buffer *buffer, struct ring_buffer_per_cpu *cpu_buffer)
 {
 	if (buffer->irq_work.waiters_pending) {
 		buffer->irq_work.waiters_pending = false;
 		/* irq_work_queue() supplies it's own memory barriers */
-		irq_work_queue(&buffer->irq_work.work);
+		rb_irq_work_queue(&buffer->irq_work);
 	}
 
 	if (cpu_buffer->irq_work.waiters_pending) {
 		cpu_buffer->irq_work.waiters_pending = false;
 		/* irq_work_queue() supplies it's own memory barriers */
-		irq_work_queue(&cpu_buffer->irq_work.work);
+		rb_irq_work_queue(&cpu_buffer->irq_work);
 	}
 
 	if (cpu_buffer->last_pages_touch == local_read(&cpu_buffer->pages_touched))
@@ -4045,7 +4063,7 @@ rb_wakeups(struct trace_buffer *buffer, struct ring_buffer_per_cpu *cpu_buffer)
 	cpu_buffer->irq_work.wakeup_full = true;
 	cpu_buffer->irq_work.full_waiters_pending = false;
 	/* irq_work_queue() supplies it's own memory barriers */
-	irq_work_queue(&cpu_buffer->irq_work.work);
+	rb_irq_work_queue(&cpu_buffer->irq_work);
 }
 
 #ifdef CONFIG_RING_BUFFER_RECORD_RECURSION
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index b1cb30a7b83d..2f6fbf9e7caf 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -67,7 +67,7 @@
  * insertions into the ring-buffer such as trace_printk could occurred
  * at the same time, giving false positive or negative results.
  */
-static bool __read_mostly tracing_selftest_running;
+bool __read_mostly tracing_selftest_running;
 
 /*
  * If boot-time tracing including tracers/events via kernel cmdline
@@ -83,7 +83,6 @@ void __init disable_tracing_selftest(const char *reason)
 	}
 }
 #else
-#define tracing_selftest_running	0
 #define tracing_selftest_disabled	0
 #endif
 
@@ -114,7 +113,7 @@ DEFINE_PER_CPU(bool, trace_taskinfo_save);
  * of the tracer is successful. But that is the only place that sets
  * this back to zero.
  */
-static int tracing_disabled = 1;
+int tracing_disabled = 1;
 
 cpumask_var_t __read_mostly	tracing_buffer_mask;
 
@@ -535,22 +534,11 @@ static struct trace_array global_trace = {
 	.trace_flags = TRACE_DEFAULT_FLAGS,
 };
 
-static struct trace_array *printk_trace = &global_trace;
+struct trace_array *printk_trace = &global_trace;
 
 /* List of trace_arrays interested in the top level trace_marker */
 static LIST_HEAD(marker_copies);
 
-static __always_inline bool printk_binsafe(struct trace_array *tr)
-{
-	/*
-	 * The binary format of traceprintk can cause a crash if used
-	 * by a buffer from another boot. Force the use of the
-	 * non binary version of trace_printk if the trace_printk
-	 * buffer is a boot mapped ring buffer.
-	 */
-	return !(tr->flags & TRACE_ARRAY_FL_BOOT);
-}
-
 static void update_printk_trace(struct trace_array *tr)
 {
 	if (printk_trace == tr)
@@ -649,248 +637,6 @@ int tracing_check_open_get_tr(struct trace_array *tr)
 	return 0;
 }
 
-/**
- * trace_find_filtered_pid - check if a pid exists in a filtered_pid list
- * @filtered_pids: The list of pids to check
- * @search_pid: The PID to find in @filtered_pids
- *
- * Returns true if @search_pid is found in @filtered_pids, and false otherwise.
- */
-bool
-trace_find_filtered_pid(struct trace_pid_list *filtered_pids, pid_t search_pid)
-{
-	return trace_pid_list_is_set(filtered_pids, search_pid);
-}
-
-/**
- * trace_ignore_this_task - should a task be ignored for tracing
- * @filtered_pids: The list of pids to check
- * @filtered_no_pids: The list of pids not to be traced
- * @task: The task that should be ignored if not filtered
- *
- * Checks if @task should be traced or not from @filtered_pids.
- * Returns true if @task should *NOT* be traced.
- * Returns false if @task should be traced.
- */
-bool
-trace_ignore_this_task(struct trace_pid_list *filtered_pids,
-		       struct trace_pid_list *filtered_no_pids,
-		       struct task_struct *task)
-{
-	/*
-	 * If filtered_no_pids is not empty, and the task's pid is listed
-	 * in filtered_no_pids, then return true.
-	 * Otherwise, if filtered_pids is empty, that means we can
-	 * trace all tasks. If it has content, then only trace pids
-	 * within filtered_pids.
-	 */
-
-	return (filtered_pids &&
-		!trace_find_filtered_pid(filtered_pids, task->pid)) ||
-		(filtered_no_pids &&
-		 trace_find_filtered_pid(filtered_no_pids, task->pid));
-}
-
-/**
- * trace_filter_add_remove_task - Add or remove a task from a pid_list
- * @pid_list: The list to modify
- * @self: The current task for fork or NULL for exit
- * @task: The task to add or remove
- *
- * If adding a task, if @self is defined, the task is only added if @self
- * is also included in @pid_list. This happens on fork and tasks should
- * only be added when the parent is listed. If @self is NULL, then the
- * @task pid will be removed from the list, which would happen on exit
- * of a task.
- */
-void trace_filter_add_remove_task(struct trace_pid_list *pid_list,
-				  struct task_struct *self,
-				  struct task_struct *task)
-{
-	if (!pid_list)
-		return;
-
-	/* For forks, we only add if the forking task is listed */
-	if (self) {
-		if (!trace_find_filtered_pid(pid_list, self->pid))
-			return;
-	}
-
-	/* "self" is set for forks, and NULL for exits */
-	if (self)
-		trace_pid_list_set(pid_list, task->pid);
-	else
-		trace_pid_list_clear(pid_list, task->pid);
-}
-
-/**
- * trace_pid_next - Used for seq_file to get to the next pid of a pid_list
- * @pid_list: The pid list to show
- * @v: The last pid that was shown (+1 the actual pid to let zero be displayed)
- * @pos: The position of the file
- *
- * This is used by the seq_file "next" operation to iterate the pids
- * listed in a trace_pid_list structure.
- *
- * Returns the pid+1 as we want to display pid of zero, but NULL would
- * stop the iteration.
- */
-void *trace_pid_next(struct trace_pid_list *pid_list, void *v, loff_t *pos)
-{
-	long pid = (unsigned long)v;
-	unsigned int next;
-
-	(*pos)++;
-
-	/* pid already is +1 of the actual previous bit */
-	if (trace_pid_list_next(pid_list, pid, &next) < 0)
-		return NULL;
-
-	pid = next;
-
-	/* Return pid + 1 to allow zero to be represented */
-	return (void *)(pid + 1);
-}
-
-/**
- * trace_pid_start - Used for seq_file to start reading pid lists
- * @pid_list: The pid list to show
- * @pos: The position of the file
- *
- * This is used by seq_file "start" operation to start the iteration
- * of listing pids.
- *
- * Returns the pid+1 as we want to display pid of zero, but NULL would
- * stop the iteration.
- */
-void *trace_pid_start(struct trace_pid_list *pid_list, loff_t *pos)
-{
-	unsigned long pid;
-	unsigned int first;
-	loff_t l = 0;
-
-	if (trace_pid_list_first(pid_list, &first) < 0)
-		return NULL;
-
-	pid = first;
-
-	/* Return pid + 1 so that zero can be the exit value */
-	for (pid++; pid && l < *pos;
-	     pid = (unsigned long)trace_pid_next(pid_list, (void *)pid, &l))
-		;
-	return (void *)pid;
-}
-
-/**
- * trace_pid_show - show the current pid in seq_file processing
- * @m: The seq_file structure to write into
- * @v: A void pointer of the pid (+1) value to display
- *
- * Can be directly used by seq_file operations to display the current
- * pid value.
- */
-int trace_pid_show(struct seq_file *m, void *v)
-{
-	unsigned long pid = (unsigned long)v - 1;
-
-	seq_printf(m, "%lu\n", pid);
-	return 0;
-}
-
-/* 128 should be much more than enough */
-#define PID_BUF_SIZE		127
-
-int trace_pid_write(struct trace_pid_list *filtered_pids,
-		    struct trace_pid_list **new_pid_list,
-		    const char __user *ubuf, size_t cnt)
-{
-	struct trace_pid_list *pid_list;
-	struct trace_parser parser;
-	unsigned long val;
-	int nr_pids = 0;
-	ssize_t read = 0;
-	ssize_t ret;
-	loff_t pos;
-	pid_t pid;
-
-	if (trace_parser_get_init(&parser, PID_BUF_SIZE + 1))
-		return -ENOMEM;
-
-	/*
-	 * Always recreate a new array. The write is an all or nothing
-	 * operation. Always create a new array when adding new pids by
-	 * the user. If the operation fails, then the current list is
-	 * not modified.
-	 */
-	pid_list = trace_pid_list_alloc();
-	if (!pid_list) {
-		trace_parser_put(&parser);
-		return -ENOMEM;
-	}
-
-	if (filtered_pids) {
-		/* copy the current bits to the new max */
-		ret = trace_pid_list_first(filtered_pids, &pid);
-		while (!ret) {
-			ret = trace_pid_list_set(pid_list, pid);
-			if (ret < 0)
-				goto out;
-
-			ret = trace_pid_list_next(filtered_pids, pid + 1, &pid);
-			nr_pids++;
-		}
-	}
-
-	ret = 0;
-	while (cnt > 0) {
-
-		pos = 0;
-
-		ret = trace_get_user(&parser, ubuf, cnt, &pos);
-		if (ret < 0)
-			break;
-
-		read += ret;
-		ubuf += ret;
-		cnt -= ret;
-
-		if (!trace_parser_loaded(&parser))
-			break;
-
-		ret = -EINVAL;
-		if (kstrtoul(parser.buffer, 0, &val))
-			break;
-
-		pid = (pid_t)val;
-
-		if (trace_pid_list_set(pid_list, pid) < 0) {
-			ret = -1;
-			break;
-		}
-		nr_pids++;
-
-		trace_parser_clear(&parser);
-		ret = 0;
-	}
- out:
-	trace_parser_put(&parser);
-
-	if (ret < 0) {
-		trace_pid_list_free(pid_list);
-		return ret;
-	}
-
-	if (!nr_pids) {
-		/* Cleared the list of pids */
-		trace_pid_list_free(pid_list);
-		pid_list = NULL;
-	}
-
-	*new_pid_list = pid_list;
-
-	return read;
-}
-
 static u64 buffer_ftrace_now(struct array_buffer *buf, int cpu)
 {
 	u64 ts;
@@ -1033,56 +779,6 @@ static inline void trace_access_lock_init(void)
 
 #endif
 
-#ifdef CONFIG_STACKTRACE
-static void __ftrace_trace_stack(struct trace_array *tr,
-				 struct trace_buffer *buffer,
-				 unsigned int trace_ctx,
-				 int skip, struct pt_regs *regs);
-static inline void ftrace_trace_stack(struct trace_array *tr,
-				      struct trace_buffer *buffer,
-				      unsigned int trace_ctx,
-				      int skip, struct pt_regs *regs);
-
-#else
-static inline void __ftrace_trace_stack(struct trace_array *tr,
-					struct trace_buffer *buffer,
-					unsigned int trace_ctx,
-					int skip, struct pt_regs *regs)
-{
-}
-static inline void ftrace_trace_stack(struct trace_array *tr,
-				      struct trace_buffer *buffer,
-				      unsigned long trace_ctx,
-				      int skip, struct pt_regs *regs)
-{
-}
-
-#endif
-
-static __always_inline void
-trace_event_setup(struct ring_buffer_event *event,
-		  int type, unsigned int trace_ctx)
-{
-	struct trace_entry *ent = ring_buffer_event_data(event);
-
-	tracing_generic_entry_update(ent, type, trace_ctx);
-}
-
-static __always_inline struct ring_buffer_event *
-__trace_buffer_lock_reserve(struct trace_buffer *buffer,
-			  int type,
-			  unsigned long len,
-			  unsigned int trace_ctx)
-{
-	struct ring_buffer_event *event;
-
-	event = ring_buffer_lock_reserve(buffer, len);
-	if (event != NULL)
-		trace_event_setup(event, type, trace_ctx);
-
-	return event;
-}
-
 void tracer_tracing_on(struct trace_array *tr)
 {
 	if (tr->array_buffer.buffer)
@@ -1110,129 +806,10 @@ void tracing_on(void)
 }
 EXPORT_SYMBOL_GPL(tracing_on);
 
-
-static __always_inline void
-__buffer_unlock_commit(struct trace_buffer *buffer, struct ring_buffer_event *event)
-{
-	__this_cpu_write(trace_taskinfo_save, true);
-
-	/* If this is the temp buffer, we need to commit fully */
-	if (this_cpu_read(trace_buffered_event) == event) {
-		/* Length is in event->array[0] */
-		ring_buffer_write(buffer, event->array[0], &event->array[1]);
-		/* Release the temp buffer */
-		this_cpu_dec(trace_buffered_event_cnt);
-		/* ring_buffer_unlock_commit() enables preemption */
-		preempt_enable_notrace();
-	} else
-		ring_buffer_unlock_commit(buffer);
-}
-
-int __trace_array_puts(struct trace_array *tr, unsigned long ip,
-		       const char *str, int size)
-{
-	struct ring_buffer_event *event;
-	struct trace_buffer *buffer;
-	struct print_entry *entry;
-	unsigned int trace_ctx;
-	int alloc;
-
-	if (!(tr->trace_flags & TRACE_ITER(PRINTK)))
-		return 0;
-
-	if (unlikely(tracing_selftest_running && tr == &global_trace))
-		return 0;
-
-	if (unlikely(tracing_disabled))
-		return 0;
-
-	alloc = sizeof(*entry) + size + 2; /* possible \n added */
-
-	trace_ctx = tracing_gen_ctx();
-	buffer = tr->array_buffer.buffer;
-	guard(ring_buffer_nest)(buffer);
-	event = __trace_buffer_lock_reserve(buffer, TRACE_PRINT, alloc,
-					    trace_ctx);
-	if (!event)
-		return 0;
-
-	entry = ring_buffer_event_data(event);
-	entry->ip = ip;
-
-	memcpy(&entry->buf, str, size);
-
-	/* Add a newline if necessary */
-	if (entry->buf[size - 1] != '\n') {
-		entry->buf[size] = '\n';
-		entry->buf[size + 1] = '\0';
-	} else
-		entry->buf[size] = '\0';
-
-	__buffer_unlock_commit(buffer, event);
-	ftrace_trace_stack(tr, buffer, trace_ctx, 4, NULL);
-	return size;
-}
-EXPORT_SYMBOL_GPL(__trace_array_puts);
-
-/**
- * __trace_puts - write a constant string into the trace buffer.
- * @ip:	   The address of the caller
- * @str:   The constant string to write
- */
-int __trace_puts(unsigned long ip, const char *str)
-{
-	return __trace_array_puts(printk_trace, ip, str, strlen(str));
-}
-EXPORT_SYMBOL_GPL(__trace_puts);
-
-/**
- * __trace_bputs - write the pointer to a constant string into trace buffer
- * @ip:	   The address of the caller
- * @str:   The constant string to write to the buffer to
- */
-int __trace_bputs(unsigned long ip, const char *str)
-{
-	struct trace_array *tr = READ_ONCE(printk_trace);
-	struct ring_buffer_event *event;
-	struct trace_buffer *buffer;
-	struct bputs_entry *entry;
-	unsigned int trace_ctx;
-	int size = sizeof(struct bputs_entry);
-
-	if (!printk_binsafe(tr))
-		return __trace_puts(ip, str);
-
-	if (!(tr->trace_flags & TRACE_ITER(PRINTK)))
-		return 0;
-
-	if (unlikely(tracing_selftest_running || tracing_disabled))
-		return 0;
-
-	trace_ctx = tracing_gen_ctx();
-	buffer = tr->array_buffer.buffer;
-
-	guard(ring_buffer_nest)(buffer);
-	event = __trace_buffer_lock_reserve(buffer, TRACE_BPUTS, size,
-					    trace_ctx);
-	if (!event)
-		return 0;
-
-	entry = ring_buffer_event_data(event);
-	entry->ip			= ip;
-	entry->str			= str;
-
-	__buffer_unlock_commit(buffer, event);
-	ftrace_trace_stack(tr, buffer, trace_ctx, 4, NULL);
-
-	return 1;
-}
-EXPORT_SYMBOL_GPL(__trace_bputs);
-
 #ifdef CONFIG_TRACER_SNAPSHOT
 static void tracing_snapshot_instance_cond(struct trace_array *tr,
 					   void *cond_data)
 {
-	struct tracer *tracer = tr->current_trace;
 	unsigned long flags;
 
 	if (in_nmi()) {
@@ -1248,15 +825,15 @@ static void tracing_snapshot_instance_cond(struct trace_array *tr,
 		return;
 	}
 
-	/* Note, snapshot can not be used when the tracer uses it */
-	if (tracer->use_max_tr) {
-		trace_array_puts(tr, "*** LATENCY TRACER ACTIVE ***\n");
+	if (tr->mapped) {
+		trace_array_puts(tr, "*** BUFFER MEMORY MAPPED ***\n");
 		trace_array_puts(tr, "*** Can not use snapshot (sorry) ***\n");
 		return;
 	}
 
-	if (tr->mapped) {
-		trace_array_puts(tr, "*** BUFFER MEMORY MAPPED ***\n");
+	/* Note, snapshot can not be used when the tracer uses it */
+	if (tracer_uses_snapshot(tr->current_trace)) {
+		trace_array_puts(tr, "*** LATENCY TRACER ACTIVE ***\n");
 		trace_array_puts(tr, "*** Can not use snapshot (sorry) ***\n");
 		return;
 	}
@@ -1356,12 +933,12 @@ int tracing_alloc_snapshot_instance(struct trace_array *tr)
 
 		/* Make the snapshot buffer have the same order as main buffer */
 		order = ring_buffer_subbuf_order_get(tr->array_buffer.buffer);
-		ret = ring_buffer_subbuf_order_set(tr->max_buffer.buffer, order);
+		ret = ring_buffer_subbuf_order_set(tr->snapshot_buffer.buffer, order);
 		if (ret < 0)
 			return ret;
 
 		/* allocate spare buffer */
-		ret = resize_buffer_duplicate_size(&tr->max_buffer,
+		ret = resize_buffer_duplicate_size(&tr->snapshot_buffer,
 				   &tr->array_buffer, RING_BUFFER_ALL_CPUS);
 		if (ret < 0)
 			return ret;
@@ -1379,10 +956,10 @@ static void free_snapshot(struct trace_array *tr)
 	 * The max_tr ring buffer has some state (e.g. ring->clock) and
 	 * we want preserve it.
 	 */
-	ring_buffer_subbuf_order_set(tr->max_buffer.buffer, 0);
-	ring_buffer_resize(tr->max_buffer.buffer, 1, RING_BUFFER_ALL_CPUS);
-	set_buffer_entries(&tr->max_buffer, 1);
-	tracing_reset_online_cpus(&tr->max_buffer);
+	ring_buffer_subbuf_order_set(tr->snapshot_buffer.buffer, 0);
+	ring_buffer_resize(tr->snapshot_buffer.buffer, 1, RING_BUFFER_ALL_CPUS);
+	set_buffer_entries(&tr->snapshot_buffer, 1);
+	tracing_reset_online_cpus(&tr->snapshot_buffer);
 	tr->allocated_snapshot = false;
 }
 
@@ -1498,7 +1075,7 @@ int tracing_snapshot_cond_enable(struct trace_array *tr, void *cond_data,
 
 	guard(mutex)(&trace_types_lock);
 
-	if (tr->current_trace->use_max_tr)
+	if (tracer_uses_snapshot(tr->current_trace))
 		return -EBUSY;
 
 	/*
@@ -1665,9 +1242,18 @@ EXPORT_SYMBOL_GPL(tracing_off);
 void disable_trace_on_warning(void)
 {
 	if (__disable_trace_on_warning) {
+		struct trace_array *tr = READ_ONCE(printk_trace);
+
 		trace_array_printk_buf(global_trace.array_buffer.buffer, _THIS_IP_,
 			"Disabling tracing due to warning\n");
 		tracing_off();
+
+		/* Disable trace_printk() buffer too */
+		if (tr != &global_trace) {
+			trace_array_printk_buf(tr->array_buffer.buffer, _THIS_IP_,
+					       "Disabling tracing due to warning\n");
+			tracer_tracing_off(tr);
+		}
 	}
 }
 
@@ -1902,10 +1488,7 @@ static ssize_t trace_seq_to_buffer(struct trace_seq *s, void *buf, size_t cnt)
 unsigned long __read_mostly	tracing_thresh;
 
 #ifdef CONFIG_TRACER_MAX_TRACE
-static const struct file_operations tracing_max_lat_fops;
-
 #ifdef LATENCY_FS_NOTIFY
-
 static struct workqueue_struct *fsnotify_wq;
 
 static void latency_fsnotify_workfn(struct work_struct *work)
@@ -1922,17 +1505,6 @@ static void latency_fsnotify_workfn_irq(struct irq_work *iwork)
 	queue_work(fsnotify_wq, &tr->fsnotify_work);
 }
 
-static void trace_create_maxlat_file(struct trace_array *tr,
-				     struct dentry *d_tracer)
-{
-	INIT_WORK(&tr->fsnotify_work, latency_fsnotify_workfn);
-	init_irq_work(&tr->fsnotify_irqwork, latency_fsnotify_workfn_irq);
-	tr->d_max_latency = trace_create_file("tracing_max_latency",
-					      TRACE_MODE_WRITE,
-					      d_tracer, tr,
-					      &tracing_max_lat_fops);
-}
-
 __init static int latency_fsnotify_init(void)
 {
 	fsnotify_wq = alloc_workqueue("tr_max_lat_wq",
@@ -1957,14 +1529,22 @@ void latency_fsnotify(struct trace_array *tr)
 	 */
 	irq_work_queue(&tr->fsnotify_irqwork);
 }
+#endif /* !LATENCY_FS_NOTIFY */
 
-#else /* !LATENCY_FS_NOTIFY */
-
-#define trace_create_maxlat_file(tr, d_tracer)				\
-	trace_create_file("tracing_max_latency", TRACE_MODE_WRITE,	\
-			  d_tracer, tr, &tracing_max_lat_fops)
+static const struct file_operations tracing_max_lat_fops;
 
+static void trace_create_maxlat_file(struct trace_array *tr,
+				     struct dentry *d_tracer)
+{
+#ifdef LATENCY_FS_NOTIFY
+	INIT_WORK(&tr->fsnotify_work, latency_fsnotify_workfn);
+	init_irq_work(&tr->fsnotify_irqwork, latency_fsnotify_workfn_irq);
 #endif
+	tr->d_max_latency = trace_create_file("tracing_max_latency",
+					      TRACE_MODE_WRITE,
+					      d_tracer, tr,
+					      &tracing_max_lat_fops);
+}
 
 /*
  * Copy the new maximum trace into the separate maximum-trace
@@ -1975,8 +1555,8 @@ static void
 __update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu)
 {
 	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 array_buffer *max_buf = &tr->snapshot_buffer;
 	struct trace_array_cpu *max_data = per_cpu_ptr(max_buf->data, cpu);
 
 	max_buf->cpu = cpu;
@@ -2005,7 +1585,14 @@ __update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu)
 	tracing_record_cmdline(tsk);
 	latency_fsnotify(tr);
 }
+#else
+static inline void trace_create_maxlat_file(struct trace_array *tr,
+					    struct dentry *d_tracer) { }
+static inline void __update_max_tr(struct trace_array *tr,
+				   struct task_struct *tsk, int cpu) { }
+#endif /* CONFIG_TRACER_MAX_TRACE */
 
+#ifdef CONFIG_TRACER_SNAPSHOT
 /**
  * update_max_tr - snapshot all trace buffers from global_trace to max_tr
  * @tr: tracer
@@ -2035,17 +1622,16 @@ update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu,
 
 	/* 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);
+		ring_buffer_record_on(tr->snapshot_buffer.buffer);
 	else
-		ring_buffer_record_off(tr->max_buffer.buffer);
+		ring_buffer_record_off(tr->snapshot_buffer.buffer);
 
-#ifdef CONFIG_TRACER_SNAPSHOT
 	if (tr->cond_snapshot && !tr->cond_snapshot->update(tr, cond_data)) {
 		arch_spin_unlock(&tr->max_lock);
 		return;
 	}
-#endif
-	swap(tr->array_buffer.buffer, tr->max_buffer.buffer);
+
+	swap(tr->array_buffer.buffer, tr->snapshot_buffer.buffer);
 
 	__update_max_tr(tr, tsk, cpu);
 
@@ -2080,7 +1666,7 @@ 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->array_buffer.buffer, cpu);
+	ret = ring_buffer_swap_cpu(tr->snapshot_buffer.buffer, tr->array_buffer.buffer, cpu);
 
 	if (ret == -EBUSY) {
 		/*
@@ -2090,7 +1676,7 @@ update_max_tr_single(struct trace_array *tr, struct task_struct *tsk, int cpu)
 		 * and flag that it failed.
 		 * Another reason is resize is in progress.
 		 */
-		trace_array_printk_buf(tr->max_buffer.buffer, _THIS_IP_,
+		trace_array_printk_buf(tr->snapshot_buffer.buffer, _THIS_IP_,
 			"Failed to swap buffers due to commit or resize in progress\n");
 	}
 
@@ -2099,8 +1685,7 @@ update_max_tr_single(struct trace_array *tr, struct task_struct *tsk, int cpu)
 	__update_max_tr(tr, tsk, cpu);
 	arch_spin_unlock(&tr->max_lock);
 }
-
-#endif /* CONFIG_TRACER_MAX_TRACE */
+#endif /* CONFIG_TRACER_SNAPSHOT */
 
 struct pipe_wait {
 	struct trace_iterator		*iter;
@@ -2133,13 +1718,13 @@ static int wait_on_pipe(struct trace_iterator *iter, int full)
 	ret = ring_buffer_wait(iter->array_buffer->buffer, iter->cpu_file, full,
 			       wait_pipe_cond, &pwait);
 
-#ifdef CONFIG_TRACER_MAX_TRACE
+#ifdef CONFIG_TRACER_SNAPSHOT
 	/*
 	 * Make sure this is still the snapshot buffer, as if a snapshot were
 	 * to happen, this would now be the main buffer.
 	 */
 	if (iter->snapshot)
-		iter->array_buffer = &iter->tr->max_buffer;
+		iter->array_buffer = &iter->tr->snapshot_buffer;
 #endif
 	return ret;
 }
@@ -2204,10 +1789,10 @@ static int run_tracer_selftest(struct tracer *type)
 	tr->current_trace_flags = type->flags ? : type->default_flags;
 
 #ifdef CONFIG_TRACER_MAX_TRACE
-	if (type->use_max_tr) {
+	if (tracer_uses_snapshot(type)) {
 		/* If we expanded the buffers, make sure the max is expanded too */
 		if (tr->ring_buffer_expanded)
-			ring_buffer_resize(tr->max_buffer.buffer, trace_buf_size,
+			ring_buffer_resize(tr->snapshot_buffer.buffer, trace_buf_size,
 					   RING_BUFFER_ALL_CPUS);
 		tr->allocated_snapshot = true;
 	}
@@ -2229,12 +1814,12 @@ static int run_tracer_selftest(struct tracer *type)
 	tracing_reset_online_cpus(&tr->array_buffer);
 
 #ifdef CONFIG_TRACER_MAX_TRACE
-	if (type->use_max_tr) {
+	if (tracer_uses_snapshot(type)) {
 		tr->allocated_snapshot = false;
 
 		/* Shrink the max buffer again */
 		if (tr->ring_buffer_expanded)
-			ring_buffer_resize(tr->max_buffer.buffer, 1,
+			ring_buffer_resize(tr->snapshot_buffer.buffer, 1,
 					   RING_BUFFER_ALL_CPUS);
 	}
 #endif
@@ -2476,8 +2061,8 @@ void tracing_reset_all_online_cpus_unlocked(void)
 			continue;
 		tr->clear_trace = false;
 		tracing_reset_online_cpus(&tr->array_buffer);
-#ifdef CONFIG_TRACER_MAX_TRACE
-		tracing_reset_online_cpus(&tr->max_buffer);
+#ifdef CONFIG_TRACER_SNAPSHOT
+		tracing_reset_online_cpus(&tr->snapshot_buffer);
 #endif
 	}
 }
@@ -2516,8 +2101,8 @@ static void tracing_start_tr(struct trace_array *tr)
 	if (buffer)
 		ring_buffer_record_enable(buffer);
 
-#ifdef CONFIG_TRACER_MAX_TRACE
-	buffer = tr->max_buffer.buffer;
+#ifdef CONFIG_TRACER_SNAPSHOT
+	buffer = tr->snapshot_buffer.buffer;
 	if (buffer)
 		ring_buffer_record_enable(buffer);
 #endif
@@ -2552,8 +2137,8 @@ static void tracing_stop_tr(struct trace_array *tr)
 	if (buffer)
 		ring_buffer_record_disable(buffer);
 
-#ifdef CONFIG_TRACER_MAX_TRACE
-	buffer = tr->max_buffer.buffer;
+#ifdef CONFIG_TRACER_SNAPSHOT
+	buffer = tr->snapshot_buffer.buffer;
 	if (buffer)
 		ring_buffer_record_disable(buffer);
 #endif
@@ -3001,10 +2586,10 @@ 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 trace_array *tr,
-				 struct trace_buffer *buffer,
-				 unsigned int trace_ctx,
-				 int skip, struct pt_regs *regs)
+void __ftrace_trace_stack(struct trace_array *tr,
+			  struct trace_buffer *buffer,
+			  unsigned int trace_ctx,
+			  int skip, struct pt_regs *regs)
 {
 	struct ring_buffer_event *event;
 	unsigned int size, nr_entries;
@@ -3087,17 +2672,6 @@ static void __ftrace_trace_stack(struct trace_array *tr,
 	trace_clear_recursion(bit);
 }
 
-static inline void ftrace_trace_stack(struct trace_array *tr,
-				      struct trace_buffer *buffer,
-				      unsigned int trace_ctx,
-				      int skip, struct pt_regs *regs)
-{
-	if (!(tr->trace_flags & TRACE_ITER(STACKTRACE)))
-		return;
-
-	__ftrace_trace_stack(tr, buffer, trace_ctx, skip, regs);
-}
-
 void __trace_stack(struct trace_array *tr, unsigned int trace_ctx,
 		   int skip)
 {
@@ -3232,324 +2806,6 @@ void trace_last_func_repeats(struct trace_array *tr,
 	__buffer_unlock_commit(buffer, event);
 }
 
-/* created for use with alloc_percpu */
-struct trace_buffer_struct {
-	int nesting;
-	char buffer[4][TRACE_BUF_SIZE];
-};
-
-static struct trace_buffer_struct __percpu *trace_percpu_buffer;
-
-/*
- * This allows for lockless recording.  If we're nested too deeply, then
- * this returns NULL.
- */
-static char *get_trace_buf(void)
-{
-	struct trace_buffer_struct *buffer = this_cpu_ptr(trace_percpu_buffer);
-
-	if (!trace_percpu_buffer || buffer->nesting >= 4)
-		return NULL;
-
-	buffer->nesting++;
-
-	/* Interrupts must see nesting incremented before we use the buffer */
-	barrier();
-	return &buffer->buffer[buffer->nesting - 1][0];
-}
-
-static void put_trace_buf(void)
-{
-	/* Don't let the decrement of nesting leak before this */
-	barrier();
-	this_cpu_dec(trace_percpu_buffer->nesting);
-}
-
-static int alloc_percpu_trace_buffer(void)
-{
-	struct trace_buffer_struct __percpu *buffers;
-
-	if (trace_percpu_buffer)
-		return 0;
-
-	buffers = alloc_percpu(struct trace_buffer_struct);
-	if (MEM_FAIL(!buffers, "Could not allocate percpu trace_printk buffer"))
-		return -ENOMEM;
-
-	trace_percpu_buffer = buffers;
-	return 0;
-}
-
-static int buffers_allocated;
-
-void trace_printk_init_buffers(void)
-{
-	if (buffers_allocated)
-		return;
-
-	if (alloc_percpu_trace_buffer())
-		return;
-
-	/* trace_printk() is for debug use only. Don't use it in production. */
-
-	pr_warn("\n");
-	pr_warn("**********************************************************\n");
-	pr_warn("**   NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE   **\n");
-	pr_warn("**                                                      **\n");
-	pr_warn("** trace_printk() being used. Allocating extra memory.  **\n");
-	pr_warn("**                                                      **\n");
-	pr_warn("** This means that this is a DEBUG kernel and it is     **\n");
-	pr_warn("** unsafe for production use.                           **\n");
-	pr_warn("**                                                      **\n");
-	pr_warn("** If you see this message and you are not debugging    **\n");
-	pr_warn("** the kernel, report this immediately to your vendor!  **\n");
-	pr_warn("**                                                      **\n");
-	pr_warn("**   NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE   **\n");
-	pr_warn("**********************************************************\n");
-
-	/* Expand the buffers to set size */
-	tracing_update_buffers(&global_trace);
-
-	buffers_allocated = 1;
-
-	/*
-	 * trace_printk_init_buffers() can be called by modules.
-	 * If that happens, then we need to start cmdline recording
-	 * directly here. If the global_trace.buffer is already
-	 * allocated here, then this was called by module code.
-	 */
-	if (global_trace.array_buffer.buffer)
-		tracing_start_cmdline_record();
-}
-EXPORT_SYMBOL_GPL(trace_printk_init_buffers);
-
-void trace_printk_start_comm(void)
-{
-	/* Start tracing comms if trace printk is set */
-	if (!buffers_allocated)
-		return;
-	tracing_start_cmdline_record();
-}
-
-static void trace_printk_start_stop_comm(int enabled)
-{
-	if (!buffers_allocated)
-		return;
-
-	if (enabled)
-		tracing_start_cmdline_record();
-	else
-		tracing_stop_cmdline_record();
-}
-
-/**
- * trace_vbprintk - write binary msg to tracing buffer
- * @ip:    The address of the caller
- * @fmt:   The string format to write to the buffer
- * @args:  Arguments for @fmt
- */
-int trace_vbprintk(unsigned long ip, const char *fmt, va_list args)
-{
-	struct ring_buffer_event *event;
-	struct trace_buffer *buffer;
-	struct trace_array *tr = READ_ONCE(printk_trace);
-	struct bprint_entry *entry;
-	unsigned int trace_ctx;
-	char *tbuffer;
-	int len = 0, size;
-
-	if (!printk_binsafe(tr))
-		return trace_vprintk(ip, fmt, args);
-
-	if (unlikely(tracing_selftest_running || tracing_disabled))
-		return 0;
-
-	/* Don't pollute graph traces with trace_vprintk internals */
-	pause_graph_tracing();
-
-	trace_ctx = tracing_gen_ctx();
-	guard(preempt_notrace)();
-
-	tbuffer = get_trace_buf();
-	if (!tbuffer) {
-		len = 0;
-		goto out_nobuffer;
-	}
-
-	len = vbin_printf((u32 *)tbuffer, TRACE_BUF_SIZE/sizeof(int), fmt, args);
-
-	if (len > TRACE_BUF_SIZE/sizeof(int) || len < 0)
-		goto out_put;
-
-	size = sizeof(*entry) + sizeof(u32) * len;
-	buffer = tr->array_buffer.buffer;
-	scoped_guard(ring_buffer_nest, buffer) {
-		event = __trace_buffer_lock_reserve(buffer, TRACE_BPRINT, size,
-						    trace_ctx);
-		if (!event)
-			goto out_put;
-		entry = ring_buffer_event_data(event);
-		entry->ip			= ip;
-		entry->fmt			= fmt;
-
-		memcpy(entry->buf, tbuffer, sizeof(u32) * len);
-		__buffer_unlock_commit(buffer, event);
-		ftrace_trace_stack(tr, buffer, trace_ctx, 6, NULL);
-	}
-out_put:
-	put_trace_buf();
-
-out_nobuffer:
-	unpause_graph_tracing();
-
-	return len;
-}
-EXPORT_SYMBOL_GPL(trace_vbprintk);
-
-static __printf(3, 0)
-int __trace_array_vprintk(struct trace_buffer *buffer,
-			  unsigned long ip, const char *fmt, va_list args)
-{
-	struct ring_buffer_event *event;
-	int len = 0, size;
-	struct print_entry *entry;
-	unsigned int trace_ctx;
-	char *tbuffer;
-
-	if (tracing_disabled)
-		return 0;
-
-	/* Don't pollute graph traces with trace_vprintk internals */
-	pause_graph_tracing();
-
-	trace_ctx = tracing_gen_ctx();
-	guard(preempt_notrace)();
-
-
-	tbuffer = get_trace_buf();
-	if (!tbuffer) {
-		len = 0;
-		goto out_nobuffer;
-	}
-
-	len = vscnprintf(tbuffer, TRACE_BUF_SIZE, fmt, args);
-
-	size = sizeof(*entry) + len + 1;
-	scoped_guard(ring_buffer_nest, buffer) {
-		event = __trace_buffer_lock_reserve(buffer, TRACE_PRINT, size,
-						    trace_ctx);
-		if (!event)
-			goto out;
-		entry = ring_buffer_event_data(event);
-		entry->ip = ip;
-
-		memcpy(&entry->buf, tbuffer, len + 1);
-		__buffer_unlock_commit(buffer, event);
-		ftrace_trace_stack(printk_trace, buffer, trace_ctx, 6, NULL);
-	}
-out:
-	put_trace_buf();
-
-out_nobuffer:
-	unpause_graph_tracing();
-
-	return len;
-}
-
-int trace_array_vprintk(struct trace_array *tr,
-			unsigned long ip, const char *fmt, va_list args)
-{
-	if (tracing_selftest_running && tr == &global_trace)
-		return 0;
-
-	return __trace_array_vprintk(tr->array_buffer.buffer, ip, fmt, args);
-}
-
-/**
- * trace_array_printk - Print a message to a specific instance
- * @tr: The instance trace_array descriptor
- * @ip: The instruction pointer that this is called from.
- * @fmt: The format to print (printf format)
- *
- * If a subsystem sets up its own instance, they have the right to
- * printk strings into their tracing instance buffer using this
- * function. Note, this function will not write into the top level
- * buffer (use trace_printk() for that), as writing into the top level
- * buffer should only have events that can be individually disabled.
- * trace_printk() is only used for debugging a kernel, and should not
- * be ever incorporated in normal use.
- *
- * trace_array_printk() can be used, as it will not add noise to the
- * top level tracing buffer.
- *
- * Note, trace_array_init_printk() must be called on @tr before this
- * can be used.
- */
-int trace_array_printk(struct trace_array *tr,
-		       unsigned long ip, const char *fmt, ...)
-{
-	int ret;
-	va_list ap;
-
-	if (!tr)
-		return -ENOENT;
-
-	/* This is only allowed for created instances */
-	if (tr == &global_trace)
-		return 0;
-
-	if (!(tr->trace_flags & TRACE_ITER(PRINTK)))
-		return 0;
-
-	va_start(ap, fmt);
-	ret = trace_array_vprintk(tr, ip, fmt, ap);
-	va_end(ap);
-	return ret;
-}
-EXPORT_SYMBOL_GPL(trace_array_printk);
-
-/**
- * trace_array_init_printk - Initialize buffers for trace_array_printk()
- * @tr: The trace array to initialize the buffers for
- *
- * As trace_array_printk() only writes into instances, they are OK to
- * have in the kernel (unlike trace_printk()). This needs to be called
- * before trace_array_printk() can be used on a trace_array.
- */
-int trace_array_init_printk(struct trace_array *tr)
-{
-	if (!tr)
-		return -ENOENT;
-
-	/* This is only allowed for created instances */
-	if (tr == &global_trace)
-		return -EINVAL;
-
-	return alloc_percpu_trace_buffer();
-}
-EXPORT_SYMBOL_GPL(trace_array_init_printk);
-
-int trace_array_printk_buf(struct trace_buffer *buffer,
-			   unsigned long ip, const char *fmt, ...)
-{
-	int ret;
-	va_list ap;
-
-	if (!(printk_trace->trace_flags & TRACE_ITER(PRINTK)))
-		return 0;
-
-	va_start(ap, fmt);
-	ret = __trace_array_vprintk(buffer, ip, fmt, ap);
-	va_end(ap);
-	return ret;
-}
-
-int trace_vprintk(unsigned long ip, const char *fmt, va_list args)
-{
-	return trace_array_vprintk(printk_trace, ip, fmt, args);
-}
-EXPORT_SYMBOL_GPL(trace_vprintk);
-
 static void trace_iterator_increment(struct trace_iterator *iter)
 {
 	struct ring_buffer_iter *buf_iter = trace_buffer_iter(iter, iter->cpu);
@@ -3986,10 +3242,8 @@ static void *s_start(struct seq_file *m, loff_t *pos)
 	}
 	mutex_unlock(&trace_types_lock);
 
-#ifdef CONFIG_TRACER_MAX_TRACE
-	if (iter->snapshot && iter->trace->use_max_tr)
+	if (iter->snapshot && tracer_uses_snapshot(iter->trace))
 		return ERR_PTR(-EBUSY);
-#endif
 
 	if (*pos != iter->pos) {
 		iter->ent = NULL;
@@ -4028,10 +3282,8 @@ static void s_stop(struct seq_file *m, void *p)
 {
 	struct trace_iterator *iter = m->private;
 
-#ifdef CONFIG_TRACER_MAX_TRACE
-	if (iter->snapshot && iter->trace->use_max_tr)
+	if (iter->snapshot && tracer_uses_snapshot(iter->trace))
 		return;
-#endif
 
 	trace_access_unlock(iter->cpu_file);
 	trace_event_read_unlock();
@@ -4285,7 +3537,7 @@ static enum print_line_t print_trace_fmt(struct trace_iterator *iter)
 			/* ftrace and system call events are still OK */
 			if ((event->type > __TRACE_LAST_TYPE) &&
 			    !is_syscall_event(event))
-			return print_event_fields(iter, event);
+				return print_event_fields(iter, event);
 		}
 		return event->funcs->trace(iter, sym_flags, event);
 	}
@@ -4508,7 +3760,7 @@ static void test_ftrace_alive(struct seq_file *m)
 		    "#          MAY BE MISSING FUNCTION EVENTS\n");
 }
 
-#ifdef CONFIG_TRACER_MAX_TRACE
+#ifdef CONFIG_TRACER_SNAPSHOT
 static void show_snapshot_main_help(struct seq_file *m)
 {
 	seq_puts(m, "# echo 0 > snapshot : Clears and frees snapshot buffer\n"
@@ -4686,10 +3938,10 @@ __tracing_open(struct inode *inode, struct file *file, bool snapshot)
 
 	iter->tr = tr;
 
-#ifdef CONFIG_TRACER_MAX_TRACE
+#ifdef CONFIG_TRACER_SNAPSHOT
 	/* Currently only the top directory has a snapshot */
 	if (tr->current_trace->print_max || snapshot)
-		iter->array_buffer = &tr->max_buffer;
+		iter->array_buffer = &tr->snapshot_buffer;
 	else
 #endif
 		iter->array_buffer = &tr->array_buffer;
@@ -4758,11 +4010,6 @@ int tracing_open_generic(struct inode *inode, struct file *filp)
 	return 0;
 }
 
-bool tracing_is_disabled(void)
-{
-	return (tracing_disabled) ? true: false;
-}
-
 /*
  * Open and update trace_array ref count.
  * Must have the current trace_array passed to it.
@@ -4880,6 +4127,8 @@ static int tracing_single_release_tr(struct inode *inode, struct file *file)
 	return single_release(inode, file);
 }
 
+static bool update_last_data_if_empty(struct trace_array *tr);
+
 static int tracing_open(struct inode *inode, struct file *file)
 {
 	struct trace_array *tr = inode->i_private;
@@ -4897,13 +4146,15 @@ static int tracing_open(struct inode *inode, struct file *file)
 
 #ifdef CONFIG_TRACER_MAX_TRACE
 		if (tr->current_trace->print_max)
-			trace_buf = &tr->max_buffer;
+			trace_buf = &tr->snapshot_buffer;
 #endif
 
 		if (cpu == RING_BUFFER_ALL_CPUS)
 			tracing_reset_online_cpus(trace_buf);
 		else
 			tracing_reset_cpu(trace_buf, cpu);
+
+		update_last_data_if_empty(tr);
 	}
 
 	if (file->f_mode & FMODE_READ) {
@@ -4928,11 +4179,9 @@ static int tracing_open(struct inode *inode, struct file *file)
 static bool
 trace_ok_for_array(struct tracer *t, struct trace_array *tr)
 {
-#ifdef CONFIG_TRACER_SNAPSHOT
 	/* arrays with mapped buffer range do not have snapshots */
-	if (tr->range_addr_start && t->use_max_tr)
+	if (tr->range_addr_start && tracer_uses_snapshot(t))
 		return false;
-#endif
 	return (tr->flags & TRACE_ARRAY_FL_GLOBAL) || t->allow_instances;
 }
 
@@ -5109,15 +4358,15 @@ int tracing_set_cpumask(struct trace_array *tr,
 		if (cpumask_test_cpu(cpu, tr->tracing_cpumask) &&
 				!cpumask_test_cpu(cpu, tracing_cpumask_new)) {
 			ring_buffer_record_disable_cpu(tr->array_buffer.buffer, cpu);
-#ifdef CONFIG_TRACER_MAX_TRACE
-			ring_buffer_record_disable_cpu(tr->max_buffer.buffer, cpu);
+#ifdef CONFIG_TRACER_SNAPSHOT
+			ring_buffer_record_disable_cpu(tr->snapshot_buffer.buffer, cpu);
 #endif
 		}
 		if (!cpumask_test_cpu(cpu, tr->tracing_cpumask) &&
 				cpumask_test_cpu(cpu, tracing_cpumask_new)) {
 			ring_buffer_record_enable_cpu(tr->array_buffer.buffer, cpu);
-#ifdef CONFIG_TRACER_MAX_TRACE
-			ring_buffer_record_enable_cpu(tr->max_buffer.buffer, cpu);
+#ifdef CONFIG_TRACER_SNAPSHOT
+			ring_buffer_record_enable_cpu(tr->snapshot_buffer.buffer, cpu);
 #endif
 		}
 	}
@@ -5326,8 +4575,8 @@ int set_tracer_flag(struct trace_array *tr, u64 mask, int enabled)
 
 	case TRACE_ITER(OVERWRITE):
 		ring_buffer_change_overwrite(tr->array_buffer.buffer, enabled);
-#ifdef CONFIG_TRACER_MAX_TRACE
-		ring_buffer_change_overwrite(tr->max_buffer.buffer, enabled);
+#ifdef CONFIG_TRACER_SNAPSHOT
+		ring_buffer_change_overwrite(tr->snapshot_buffer.buffer, enabled);
 #endif
 		break;
 
@@ -5970,6 +5219,7 @@ 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->array_buffer);
+	update_last_data_if_empty(tr);
 	return t->init(tr);
 }
 
@@ -5990,7 +5240,7 @@ static void update_buffer_entries(struct array_buffer *buf, int cpu)
 	}
 }
 
-#ifdef CONFIG_TRACER_MAX_TRACE
+#ifdef CONFIG_TRACER_SNAPSHOT
 /* resize @tr's buffer to the size of @size_tr's entries */
 static int resize_buffer_duplicate_size(struct array_buffer *trace_buf,
 					struct array_buffer *size_buf, int cpu_id)
@@ -6016,7 +5266,7 @@ static int resize_buffer_duplicate_size(struct array_buffer *trace_buf,
 
 	return ret;
 }
-#endif /* CONFIG_TRACER_MAX_TRACE */
+#endif /* CONFIG_TRACER_SNAPSHOT */
 
 static int __tracing_resize_ring_buffer(struct trace_array *tr,
 					unsigned long size, int cpu)
@@ -6041,11 +5291,11 @@ static int __tracing_resize_ring_buffer(struct trace_array *tr,
 	if (ret < 0)
 		goto out_start;
 
-#ifdef CONFIG_TRACER_MAX_TRACE
+#ifdef CONFIG_TRACER_SNAPSHOT
 	if (!tr->allocated_snapshot)
 		goto out;
 
-	ret = ring_buffer_resize(tr->max_buffer.buffer, size, cpu);
+	ret = ring_buffer_resize(tr->snapshot_buffer.buffer, size, cpu);
 	if (ret < 0) {
 		int r = resize_buffer_duplicate_size(&tr->array_buffer,
 						     &tr->array_buffer, cpu);
@@ -6070,10 +5320,10 @@ static int __tracing_resize_ring_buffer(struct trace_array *tr,
 		goto out_start;
 	}
 
-	update_buffer_entries(&tr->max_buffer, cpu);
+	update_buffer_entries(&tr->snapshot_buffer, cpu);
 
  out:
-#endif /* CONFIG_TRACER_MAX_TRACE */
+#endif /* CONFIG_TRACER_SNAPSHOT */
 
 	update_buffer_entries(&tr->array_buffer, cpu);
  out_start:
@@ -6264,6 +5514,9 @@ int tracing_update_buffers(struct trace_array *tr)
 {
 	int ret = 0;
 
+	if (!tr)
+		tr = &global_trace;
+
 	guard(mutex)(&trace_types_lock);
 
 	update_last_data(tr);
@@ -6298,9 +5551,7 @@ int tracing_set_tracer(struct trace_array *tr, const char *buf)
 {
 	struct tracer *trace = NULL;
 	struct tracers *t;
-#ifdef CONFIG_TRACER_MAX_TRACE
 	bool had_max_tr;
-#endif
 	int ret;
 
 	guard(mutex)(&trace_types_lock);
@@ -6328,7 +5579,7 @@ int tracing_set_tracer(struct trace_array *tr, const char *buf)
 		return 0;
 
 #ifdef CONFIG_TRACER_SNAPSHOT
-	if (trace->use_max_tr) {
+	if (tracer_uses_snapshot(trace)) {
 		local_irq_disable();
 		arch_spin_lock(&tr->max_lock);
 		ret = tr->cond_snapshot ? -EBUSY : 0;
@@ -6360,14 +5611,13 @@ int tracing_set_tracer(struct trace_array *tr, const char *buf)
 	if (tr->current_trace->reset)
 		tr->current_trace->reset(tr);
 
-#ifdef CONFIG_TRACER_MAX_TRACE
-	had_max_tr = tr->current_trace->use_max_tr;
+	had_max_tr = tracer_uses_snapshot(tr->current_trace);
 
 	/* Current trace needs to be nop_trace before synchronize_rcu */
 	tr->current_trace = &nop_trace;
 	tr->current_trace_flags = nop_trace.flags;
 
-	if (had_max_tr && !trace->use_max_tr) {
+	if (had_max_tr && !tracer_uses_snapshot(trace)) {
 		/*
 		 * We need to make sure that the update_max_tr sees that
 		 * current_trace changed to nop_trace to keep it from
@@ -6380,24 +5630,19 @@ int tracing_set_tracer(struct trace_array *tr, const char *buf)
 		tracing_disarm_snapshot(tr);
 	}
 
-	if (!had_max_tr && trace->use_max_tr) {
+	if (!had_max_tr && tracer_uses_snapshot(trace)) {
 		ret = tracing_arm_snapshot_locked(tr);
 		if (ret)
 			return ret;
 	}
-#else
-	tr->current_trace = &nop_trace;
-#endif
 
 	tr->current_trace_flags = t->flags ? : t->tracer->flags;
 
 	if (trace->init) {
 		ret = tracer_init(trace, tr);
 		if (ret) {
-#ifdef CONFIG_TRACER_MAX_TRACE
-			if (trace->use_max_tr)
+			if (tracer_uses_snapshot(trace))
 				tracing_disarm_snapshot(tr);
-#endif
 			tr->current_trace_flags = nop_trace.flags;
 			return ret;
 		}
@@ -7602,7 +6847,7 @@ tracing_mark_write(struct file *filp, const char __user *ubuf,
 	unsigned long ip;
 	char *buf;
 
-	if (tracing_disabled)
+	if (unlikely(tracing_disabled))
 		return -EINVAL;
 
 	if (!(tr->trace_flags & TRACE_ITER(MARKERS)))
@@ -7682,7 +6927,7 @@ tracing_mark_raw_write(struct file *filp, const char __user *ubuf,
 	ssize_t written = -ENODEV;
 	char *buf;
 
-	if (tracing_disabled)
+	if (unlikely(tracing_disabled))
 		return -EINVAL;
 
 	if (!(tr->trace_flags & TRACE_ITER(MARKERS)))
@@ -7783,11 +7028,12 @@ int tracing_set_clock(struct trace_array *tr, const char *clockstr)
 	 */
 	tracing_reset_online_cpus(&tr->array_buffer);
 
-#ifdef CONFIG_TRACER_MAX_TRACE
-	if (tr->max_buffer.buffer)
-		ring_buffer_set_clock(tr->max_buffer.buffer, trace_clocks[i].func);
-	tracing_reset_online_cpus(&tr->max_buffer);
+#ifdef CONFIG_TRACER_SNAPSHOT
+	if (tr->snapshot_buffer.buffer)
+		ring_buffer_set_clock(tr->snapshot_buffer.buffer, trace_clocks[i].func);
+	tracing_reset_online_cpus(&tr->snapshot_buffer);
 #endif
+	update_last_data_if_empty(tr);
 
 	if (tr->scratch && !(tr->flags & TRACE_ARRAY_FL_LAST_BOOT)) {
 		struct trace_scratch *tscratch = tr->scratch;
@@ -7880,26 +7126,6 @@ u64 tracing_event_time_stamp(struct trace_buffer *buffer, struct ring_buffer_eve
 	return ring_buffer_event_time_stamp(buffer, rbe);
 }
 
-/*
- * Set or disable using the per CPU trace_buffer_event when possible.
- */
-int tracing_set_filter_buffering(struct trace_array *tr, bool set)
-{
-	guard(mutex)(&trace_types_lock);
-
-	if (set && tr->no_filter_buffering_ref++)
-		return 0;
-
-	if (!set) {
-		if (WARN_ON_ONCE(!tr->no_filter_buffering_ref))
-			return -EINVAL;
-
-		--tr->no_filter_buffering_ref;
-	}
-
-	return 0;
-}
-
 struct ftrace_buffer_info {
 	struct trace_iterator	iter;
 	void			*spare;
@@ -7938,7 +7164,7 @@ static int tracing_snapshot_open(struct inode *inode, struct file *file)
 		ret = 0;
 
 		iter->tr = tr;
-		iter->array_buffer = &tr->max_buffer;
+		iter->array_buffer = &tr->snapshot_buffer;
 		iter->cpu_file = tracing_get_cpu(inode);
 		m->private = iter;
 		file->private_data = m;
@@ -7975,7 +7201,7 @@ tracing_snapshot_write(struct file *filp, const char __user *ubuf, size_t cnt,
 
 	guard(mutex)(&trace_types_lock);
 
-	if (tr->current_trace->use_max_tr)
+	if (tracer_uses_snapshot(tr->current_trace))
 		return -EBUSY;
 
 	local_irq_disable();
@@ -8001,7 +7227,7 @@ tracing_snapshot_write(struct file *filp, const char __user *ubuf, size_t cnt,
 			return -EINVAL;
 #endif
 		if (tr->allocated_snapshot)
-			ret = resize_buffer_duplicate_size(&tr->max_buffer,
+			ret = resize_buffer_duplicate_size(&tr->snapshot_buffer,
 					&tr->array_buffer, iter->cpu_file);
 
 		ret = tracing_arm_snapshot_locked(tr);
@@ -8022,9 +7248,9 @@ tracing_snapshot_write(struct file *filp, const char __user *ubuf, size_t cnt,
 	default:
 		if (tr->allocated_snapshot) {
 			if (iter->cpu_file == RING_BUFFER_ALL_CPUS)
-				tracing_reset_online_cpus(&tr->max_buffer);
+				tracing_reset_online_cpus(&tr->snapshot_buffer);
 			else
-				tracing_reset_cpu(&tr->max_buffer, iter->cpu_file);
+				tracing_reset_cpu(&tr->snapshot_buffer, iter->cpu_file);
 		}
 		break;
 	}
@@ -8074,13 +7300,13 @@ static int snapshot_raw_open(struct inode *inode, struct file *filp)
 
 	info = filp->private_data;
 
-	if (info->iter.trace->use_max_tr) {
+	if (tracer_uses_snapshot(info->iter.trace)) {
 		tracing_buffers_release(inode, filp);
 		return -EBUSY;
 	}
 
 	info->iter.snapshot = true;
-	info->iter.array_buffer = &info->iter.tr->max_buffer;
+	info->iter.array_buffer = &info->iter.tr->snapshot_buffer;
 
 	return ret;
 }
@@ -8630,10 +7856,8 @@ tracing_buffers_read(struct file *filp, char __user *ubuf,
 	if (!count)
 		return 0;
 
-#ifdef CONFIG_TRACER_MAX_TRACE
-	if (iter->snapshot && iter->tr->current_trace->use_max_tr)
+	if (iter->snapshot && tracer_uses_snapshot(iter->tr->current_trace))
 		return -EBUSY;
-#endif
 
 	page_size = ring_buffer_subbuf_size_get(iter->array_buffer->buffer);
 
@@ -8817,10 +8041,8 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos,
 	int entries, i;
 	ssize_t ret = 0;
 
-#ifdef CONFIG_TRACER_MAX_TRACE
-	if (iter->snapshot && iter->tr->current_trace->use_max_tr)
+	if (iter->snapshot && tracer_uses_snapshot(iter->tr->current_trace))
 		return -EBUSY;
-#endif
 
 	page_size = ring_buffer_subbuf_size_get(iter->array_buffer->buffer);
 	if (*ppos & (page_size - 1))
@@ -8954,7 +8176,7 @@ static long tracing_buffers_ioctl(struct file *file, unsigned int cmd, unsigned
 	return 0;
 }
 
-#ifdef CONFIG_TRACER_MAX_TRACE
+#ifdef CONFIG_TRACER_SNAPSHOT
 static int get_snapshot_map(struct trace_array *tr)
 {
 	int err = 0;
@@ -9397,7 +8619,7 @@ tracing_init_tracefs_percpu(struct trace_array *tr, long cpu)
 	trace_create_cpu_file("stats", TRACE_MODE_READ, d_cpu,
 				tr, cpu, &tracing_stats_fops);
 
-	trace_create_cpu_file("buffer_size_kb", TRACE_MODE_READ, d_cpu,
+	trace_create_cpu_file("buffer_size_kb", TRACE_MODE_WRITE, d_cpu,
 				tr, cpu, &tracing_entries_fops);
 
 	if (tr->range_addr_start)
@@ -9958,12 +9180,12 @@ buffer_subbuf_size_write(struct file *filp, const char __user *ubuf,
 	if (ret)
 		goto out;
 
-#ifdef CONFIG_TRACER_MAX_TRACE
+#ifdef CONFIG_TRACER_SNAPSHOT
 
 	if (!tr->allocated_snapshot)
 		goto out_max;
 
-	ret = ring_buffer_subbuf_order_set(tr->max_buffer.buffer, order);
+	ret = ring_buffer_subbuf_order_set(tr->snapshot_buffer.buffer, order);
 	if (ret) {
 		/* Put back the old order */
 		cnt = ring_buffer_subbuf_order_set(tr->array_buffer.buffer, old_order);
@@ -10179,12 +9401,12 @@ static int allocate_trace_buffers(struct trace_array *tr, int size)
 	if (ret)
 		return ret;
 
-#ifdef CONFIG_TRACER_MAX_TRACE
+#ifdef CONFIG_TRACER_SNAPSHOT
 	/* Fix mapped buffer trace arrays do not have snapshot buffers */
 	if (tr->range_addr_start)
 		return 0;
 
-	ret = allocate_trace_buffer(tr, &tr->max_buffer,
+	ret = allocate_trace_buffer(tr, &tr->snapshot_buffer,
 				    allocate_snapshot ? size : 1);
 	if (MEM_FAIL(ret, "Failed to allocate trace buffer\n")) {
 		free_trace_buffer(&tr->array_buffer);
@@ -10206,8 +9428,8 @@ static void free_trace_buffers(struct trace_array *tr)
 	free_trace_buffer(&tr->array_buffer);
 	kfree(tr->module_delta);
 
-#ifdef CONFIG_TRACER_MAX_TRACE
-	free_trace_buffer(&tr->max_buffer);
+#ifdef CONFIG_TRACER_SNAPSHOT
+	free_trace_buffer(&tr->snapshot_buffer);
 #endif
 }
 
@@ -10348,7 +9570,7 @@ trace_array_create_systems(const char *name, const char *systems,
 	tr->syscall_buf_sz = global_trace.syscall_buf_sz;
 
 	tr->max_lock = (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED;
-#ifdef CONFIG_TRACER_MAX_TRACE
+#ifdef CONFIG_TRACER_SNAPSHOT
 	spin_lock_init(&tr->snapshot_trigger_lock);
 #endif
 	tr->current_trace = &nop_trace;
@@ -10673,9 +9895,7 @@ init_tracer_tracefs(struct trace_array *tr, struct dentry *d_tracer)
 
 	create_trace_options_dir(tr);
 
-#ifdef CONFIG_TRACER_MAX_TRACE
 	trace_create_maxlat_file(tr, d_tracer);
-#endif
 
 	if (ftrace_create_function_files(tr, d_tracer))
 		MEM_FAIL(1, "Could not allocate function filter files");
@@ -10774,7 +9994,7 @@ int tracing_init_dentry(void)
 extern struct trace_eval_map *__start_ftrace_eval_maps[];
 extern struct trace_eval_map *__stop_ftrace_eval_maps[];
 
-static struct workqueue_struct *eval_map_wq __initdata;
+struct workqueue_struct *trace_init_wq __initdata;
 static struct work_struct eval_map_work __initdata;
 static struct work_struct tracerfs_init_work __initdata;
 
@@ -10790,15 +10010,15 @@ static int __init trace_eval_init(void)
 {
 	INIT_WORK(&eval_map_work, eval_map_work_func);
 
-	eval_map_wq = alloc_workqueue("eval_map_wq", WQ_UNBOUND, 0);
-	if (!eval_map_wq) {
-		pr_err("Unable to allocate eval_map_wq\n");
+	trace_init_wq = alloc_workqueue("trace_init_wq", WQ_UNBOUND, 0);
+	if (!trace_init_wq) {
+		pr_err("Unable to allocate trace_init_wq\n");
 		/* Do work here */
 		eval_map_work_func(&eval_map_work);
 		return -ENOMEM;
 	}
 
-	queue_work(eval_map_wq, &eval_map_work);
+	queue_work(trace_init_wq, &eval_map_work);
 	return 0;
 }
 
@@ -10807,8 +10027,8 @@ subsys_initcall(trace_eval_init);
 static int __init trace_eval_sync(void)
 {
 	/* Make sure the eval map updates are finished */
-	if (eval_map_wq)
-		destroy_workqueue(eval_map_wq);
+	if (trace_init_wq)
+		destroy_workqueue(trace_init_wq);
 	return 0;
 }
 
@@ -10969,9 +10189,9 @@ static __init int tracer_init_tracefs(void)
 	if (ret)
 		return 0;
 
-	if (eval_map_wq) {
+	if (trace_init_wq) {
 		INIT_WORK(&tracerfs_init_work, tracer_init_tracefs_work_func);
-		queue_work(eval_map_wq, &tracerfs_init_work);
+		queue_work(trace_init_wq, &tracerfs_init_work);
 	} else {
 		tracer_init_tracefs_work_func(NULL);
 	}
@@ -11304,7 +10524,7 @@ ssize_t trace_parse_run_command(struct file *file, const char __user *buffer,
 	return done;
 }
 
-#ifdef CONFIG_TRACER_MAX_TRACE
+#ifdef CONFIG_TRACER_SNAPSHOT
 __init static bool tr_needs_alloc_snapshot(const char *name)
 {
 	char *test;
@@ -11494,7 +10714,7 @@ __init static void enable_instances(void)
 			}
 		} else {
 			/* Only non mapped buffers have snapshot buffers */
-			if (IS_ENABLED(CONFIG_TRACER_MAX_TRACE))
+			if (IS_ENABLED(CONFIG_TRACER_SNAPSHOT))
 				do_allocate_snapshot(name);
 		}
 
@@ -11621,7 +10841,7 @@ __init static int tracer_alloc_buffers(void)
 	global_trace.current_trace_flags = nop_trace.flags;
 
 	global_trace.max_lock = (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED;
-#ifdef CONFIG_TRACER_MAX_TRACE
+#ifdef CONFIG_TRACER_SNAPSHOT
 	spin_lock_init(&global_trace.snapshot_trigger_lock);
 #endif
 	ftrace_init_global_array_ops(&global_trace);
@@ -11689,7 +10909,7 @@ struct trace_array *trace_get_global_array(void)
 
 void __init ftrace_boot_snapshot(void)
 {
-#ifdef CONFIG_TRACER_MAX_TRACE
+#ifdef CONFIG_TRACER_SNAPSHOT
 	struct trace_array *tr;
 
 	if (!snapshot_at_boot)
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 8428c437cb9d..b8f3804586a0 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -131,7 +131,7 @@ enum trace_type {
 
 #define FAULT_STRING "(fault)"
 
-#define HIST_STACKTRACE_DEPTH	16
+#define HIST_STACKTRACE_DEPTH	31
 #define HIST_STACKTRACE_SIZE	(HIST_STACKTRACE_DEPTH * sizeof(unsigned long))
 #define HIST_STACKTRACE_SKIP	5
 
@@ -332,29 +332,33 @@ struct trace_array {
 	struct list_head	list;
 	char			*name;
 	struct array_buffer	array_buffer;
-#ifdef CONFIG_TRACER_MAX_TRACE
+#ifdef CONFIG_TRACER_SNAPSHOT
 	/*
-	 * The max_buffer is used to snapshot the trace when a maximum
+	 * The snapshot_buffer is used to snapshot the trace when a maximum
 	 * latency is reached, or when the user initiates a snapshot.
 	 * 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 array_buffer
-	 * When a snapshot is taken, the buffer of the max_buffer is swapped
-	 * with the buffer of the array_buffer and the buffers are reset for
-	 * the array_buffer so the tracing can continue.
+	 * The buffers for the snapshot_buffer are set up the same as the
+	 * array_buffer. When a snapshot is taken, the buffer of the
+	 * snapshot_buffer is swapped with the buffer of the array_buffer
+	 * and the buffers are reset for the array_buffer so the tracing can
+	 * continue.
 	 */
-	struct array_buffer	max_buffer;
+	struct array_buffer	snapshot_buffer;
 	bool			allocated_snapshot;
 	spinlock_t		snapshot_trigger_lock;
 	unsigned int		snapshot;
+#ifdef CONFIG_TRACER_MAX_TRACE
 	unsigned long		max_latency;
-#ifdef CONFIG_FSNOTIFY
 	struct dentry		*d_max_latency;
+#ifdef CONFIG_FSNOTIFY
 	struct work_struct	fsnotify_work;
 	struct irq_work		fsnotify_irqwork;
-#endif
-#endif
+#endif /* CONFIG_FSNOTIFY */
+#endif /* CONFIG_TRACER_MAX_TRACE */
+#endif /* CONFIG_TRACER_SNAPSHOT */
+
 	/* The below is for memory mapped ring buffer */
 	unsigned int		mapped;
 	unsigned long		range_addr_start;
@@ -380,7 +384,7 @@ struct trace_array {
 	 *
 	 * It is also used in other places outside the update_max_tr
 	 * so it needs to be defined outside of the
-	 * CONFIG_TRACER_MAX_TRACE.
+	 * CONFIG_TRACER_SNAPSHOT.
 	 */
 	arch_spinlock_t		max_lock;
 #ifdef CONFIG_FTRACE_SYSCALLS
@@ -479,13 +483,14 @@ extern struct trace_array *trace_array_find(const char *instance);
 extern struct trace_array *trace_array_find_get(const char *instance);
 
 extern u64 tracing_event_time_stamp(struct trace_buffer *buffer, struct ring_buffer_event *rbe);
-extern int tracing_set_filter_buffering(struct trace_array *tr, bool set);
 extern int tracing_set_clock(struct trace_array *tr, const char *clockstr);
 
 extern bool trace_clock_in_ns(struct trace_array *tr);
 
 extern unsigned long trace_adjust_address(struct trace_array *tr, unsigned long addr);
 
+extern struct trace_array *printk_trace;
+
 /*
  * The global tracer (top) should be the first trace array added,
  * but we check the flag anyway.
@@ -661,6 +666,8 @@ trace_buffer_iter(struct trace_iterator *iter, int cpu)
 	return iter->buffer_iter ? iter->buffer_iter[cpu] : NULL;
 }
 
+extern int tracing_disabled;
+
 int tracer_init(struct tracer *t, struct trace_array *tr);
 int tracing_is_enabled(void);
 void tracing_reset_online_cpus(struct array_buffer *buf);
@@ -672,7 +679,6 @@ int tracing_release_generic_tr(struct inode *inode, struct file *file);
 int tracing_open_file_tr(struct inode *inode, struct file *filp);
 int tracing_release_file_tr(struct inode *inode, struct file *filp);
 int tracing_single_release_file_tr(struct inode *inode, struct file *filp);
-bool tracing_is_disabled(void);
 bool tracer_tracing_is_on(struct trace_array *tr);
 void tracer_tracing_on(struct trace_array *tr);
 void tracer_tracing_off(struct trace_array *tr);
@@ -772,6 +778,7 @@ extern cpumask_var_t __read_mostly tracing_buffer_mask;
 extern unsigned long nsecs_to_usecs(unsigned long nsecs);
 
 extern unsigned long tracing_thresh;
+extern struct workqueue_struct *trace_init_wq __initdata;
 
 /* PID filtering */
 
@@ -790,22 +797,22 @@ int trace_pid_write(struct trace_pid_list *filtered_pids,
 		    struct trace_pid_list **new_pid_list,
 		    const char __user *ubuf, size_t cnt);
 
-#ifdef CONFIG_TRACER_MAX_TRACE
+#ifdef CONFIG_TRACER_SNAPSHOT
 void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu,
 		   void *cond_data);
 void update_max_tr_single(struct trace_array *tr,
 			  struct task_struct *tsk, int cpu);
 
-#ifdef CONFIG_FSNOTIFY
-#define LATENCY_FS_NOTIFY
+#if defined(CONFIG_TRACER_MAX_TRACE) && defined(CONFIG_FSNOTIFY)
+# define LATENCY_FS_NOTIFY
 #endif
-#endif /* CONFIG_TRACER_MAX_TRACE */
 
 #ifdef LATENCY_FS_NOTIFY
 void latency_fsnotify(struct trace_array *tr);
 #else
 static inline void latency_fsnotify(struct trace_array *tr) { }
 #endif
+#endif /* CONFIG_TRACER_SNAPSHOT */
 
 #ifdef CONFIG_STACKTRACE
 void __trace_stack(struct trace_array *tr, unsigned int trace_ctx, int skip);
@@ -816,6 +823,18 @@ static inline void __trace_stack(struct trace_array *tr, unsigned int trace_ctx,
 }
 #endif /* CONFIG_STACKTRACE */
 
+#ifdef CONFIG_TRACER_MAX_TRACE
+static inline bool tracer_uses_snapshot(struct tracer *tracer)
+{
+	return tracer->use_max_tr;
+}
+#else
+static inline bool tracer_uses_snapshot(struct tracer *tracer)
+{
+	return false;
+}
+#endif
+
 void trace_last_func_repeats(struct trace_array *tr,
 			     struct trace_func_repeats *last_info,
 			     unsigned int trace_ctx);
@@ -865,6 +884,7 @@ extern int trace_selftest_startup_nop(struct tracer *trace,
 					 struct trace_array *tr);
 extern int trace_selftest_startup_branch(struct tracer *trace,
 					 struct trace_array *tr);
+extern bool __read_mostly tracing_selftest_running;
 /*
  * Tracer data references selftest functions that only occur
  * on boot up. These can be __init functions. Thus, when selftests
@@ -877,6 +897,7 @@ static inline void __init disable_tracing_selftest(const char *reason)
 }
 /* Tracers are seldom changed. Optimize when selftests are disabled. */
 #define __tracer_data		__read_mostly
+#define tracing_selftest_running	0
 #endif /* CONFIG_FTRACE_STARTUP_TEST */
 
 extern void *head_page(struct trace_array_cpu *data);
@@ -1414,6 +1435,7 @@ extern int trace_get_user(struct trace_parser *parser, const char __user *ubuf,
 		C(COPY_MARKER,		"copy_trace_marker"),	\
 		C(PAUSE_ON_TRACE,	"pause-on-trace"),	\
 		C(HASH_PTR,		"hash-ptr"),	/* Print hashed pointer */ \
+		C(BITMASK_LIST,		"bitmask-list"),	\
 		FUNCTION_FLAGS					\
 		FGRAPH_FLAGS					\
 		STACK_FLAGS					\
@@ -1567,6 +1589,47 @@ char *trace_user_fault_read(struct trace_user_buf_info *tinfo,
 			    const char __user *ptr, size_t size,
 			    trace_user_buf_copy copy_func, void *data);
 
+static __always_inline void
+trace_event_setup(struct ring_buffer_event *event,
+		  int type, unsigned int trace_ctx)
+{
+	struct trace_entry *ent = ring_buffer_event_data(event);
+
+	tracing_generic_entry_update(ent, type, trace_ctx);
+}
+
+static __always_inline struct ring_buffer_event *
+__trace_buffer_lock_reserve(struct trace_buffer *buffer,
+			  int type,
+			  unsigned long len,
+			  unsigned int trace_ctx)
+{
+	struct ring_buffer_event *event;
+
+	event = ring_buffer_lock_reserve(buffer, len);
+	if (event != NULL)
+		trace_event_setup(event, type, trace_ctx);
+
+	return event;
+}
+
+static __always_inline void
+__buffer_unlock_commit(struct trace_buffer *buffer, struct ring_buffer_event *event)
+{
+	__this_cpu_write(trace_taskinfo_save, true);
+
+	/* If this is the temp buffer, we need to commit fully */
+	if (this_cpu_read(trace_buffered_event) == event) {
+		/* Length is in event->array[0] */
+		ring_buffer_write(buffer, event->array[0], &event->array[1]);
+		/* Release the temp buffer */
+		this_cpu_dec(trace_buffered_event_cnt);
+		/* ring_buffer_unlock_commit() enables preemption */
+		preempt_enable_notrace();
+	} else
+		ring_buffer_unlock_commit(buffer);
+}
+
 static inline void
 __trace_event_discard_commit(struct trace_buffer *buffer,
 			     struct ring_buffer_event *event)
@@ -2087,6 +2150,7 @@ extern const char *__stop___tracepoint_str[];
 
 void trace_printk_control(bool enabled);
 void trace_printk_start_comm(void);
+void trace_printk_start_stop_comm(int enabled);
 int trace_keep_overwrite(struct tracer *tracer, u64 mask, int set);
 int set_tracer_flag(struct trace_array *tr, u64 mask, int enabled);
 
@@ -2237,6 +2301,37 @@ static inline void sanitize_event_name(char *name)
 			*name = '_';
 }
 
+#ifdef CONFIG_STACKTRACE
+void __ftrace_trace_stack(struct trace_array *tr,
+			  struct trace_buffer *buffer,
+			  unsigned int trace_ctx,
+			  int skip, struct pt_regs *regs);
+
+static __always_inline void ftrace_trace_stack(struct trace_array *tr,
+					       struct trace_buffer *buffer,
+					       unsigned int trace_ctx,
+					       int skip, struct pt_regs *regs)
+{
+	if (!(tr->trace_flags & TRACE_ITER(STACKTRACE)))
+		return;
+
+	__ftrace_trace_stack(tr, buffer, trace_ctx, skip, regs);
+}
+#else
+static inline void __ftrace_trace_stack(struct trace_array *tr,
+					struct trace_buffer *buffer,
+					unsigned int trace_ctx,
+					int skip, struct pt_regs *regs)
+{
+}
+static inline void ftrace_trace_stack(struct trace_array *tr,
+				      struct trace_buffer *buffer,
+				      unsigned long trace_ctx,
+				      int skip, struct pt_regs *regs)
+{
+}
+#endif
+
 /*
  * This is a generic way to read and write a u64 value from a file in tracefs.
  *
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 137b4d9bb116..61fe01dce7a6 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -649,6 +649,22 @@ bool trace_event_ignore_this_pid(struct trace_event_file *trace_file)
 }
 EXPORT_SYMBOL_GPL(trace_event_ignore_this_pid);
 
+/**
+ * trace_event_buffer_reserve - reserve space on the ring buffer for an event
+ * @fbuffer: information about how to save the event
+ * @trace_file: the instance file descriptor for the event
+ * @len: The length of the event
+ *
+ * The @fbuffer has information about the ring buffer and data will
+ * be added to it to be used by the call to trace_event_buffer_commit().
+ * The @trace_file is the desrciptor with information about the status
+ * of the given event for a specific trace_array instance.
+ * The @len is the length of data to save for the event.
+ *
+ * Returns a pointer to the data on the ring buffer or NULL if the
+ *   event was not reserved (event was filtered, too big, or the buffer
+ *   simply was disabled for write).
+ */
 void *trace_event_buffer_reserve(struct trace_event_buffer *fbuffer,
 				 struct trace_event_file *trace_file,
 				 unsigned long len)
@@ -1662,6 +1678,82 @@ static void t_stop(struct seq_file *m, void *p)
 	mutex_unlock(&event_mutex);
 }
 
+static int get_call_len(struct trace_event_call *call)
+{
+	int len;
+
+	/* Get the length of "<system>:<event>" */
+	len = strlen(call->class->system) + 1;
+	len += strlen(trace_event_name(call));
+
+	/* Set the index to 32 bytes to separate event from data */
+	return len >= 32 ? 1 : 32 - len;
+}
+
+/**
+ * t_show_filters - seq_file callback to display active event filters
+ * @m: The seq_file interface for formatted output
+ * @v: The current trace_event_file being iterated
+ *
+ * Identifies and prints active filters for the current event file in the
+ * iteration. If a filter is applied to the current event and, if so,
+ * prints the system name, event name, and the filter string.
+ */
+static int t_show_filters(struct seq_file *m, void *v)
+{
+	struct trace_event_file *file = v;
+	struct trace_event_call *call = file->event_call;
+	struct event_filter *filter;
+	int len;
+
+	guard(rcu)();
+	filter = rcu_dereference(file->filter);
+	if (!filter || !filter->filter_string)
+		return 0;
+
+	len = get_call_len(call);
+
+	seq_printf(m, "%s:%s%*.s%s\n", call->class->system,
+		   trace_event_name(call), len, "", filter->filter_string);
+
+	return 0;
+}
+
+/**
+ * t_show_triggers - seq_file callback to display active event triggers
+ * @m: The seq_file interface for formatted output
+ * @v: The current trace_event_file being iterated
+ *
+ * Iterates through the trigger list of the current event file and prints
+ * each active trigger's configuration using its associated print
+ * operation.
+ */
+static int t_show_triggers(struct seq_file *m, void *v)
+{
+	struct trace_event_file *file = v;
+	struct trace_event_call *call = file->event_call;
+	struct event_trigger_data *data;
+	int len;
+
+	/*
+	 * The event_mutex is held by t_start(), protecting the
+	 * file->triggers list traversal.
+	 */
+	if (list_empty(&file->triggers))
+		return 0;
+
+	len = get_call_len(call);
+
+	list_for_each_entry_rcu(data, &file->triggers, list) {
+		seq_printf(m, "%s:%s%*.s", call->class->system,
+			   trace_event_name(call), len, "");
+
+		data->cmd_ops->print(m, data);
+	}
+
+	return 0;
+}
+
 #ifdef CONFIG_MODULES
 static int s_show(struct seq_file *m, void *v)
 {
@@ -2176,7 +2268,7 @@ static int subsystem_open(struct inode *inode, struct file *filp)
 	struct event_subsystem *system = NULL;
 	int ret;
 
-	if (tracing_is_disabled())
+	if (unlikely(tracing_disabled))
 		return -ENODEV;
 
 	/* Make sure the system still exists */
@@ -2489,6 +2581,8 @@ ftrace_event_npid_write(struct file *filp, const char __user *ubuf,
 
 static int ftrace_event_avail_open(struct inode *inode, struct file *file);
 static int ftrace_event_set_open(struct inode *inode, struct file *file);
+static int ftrace_event_show_filters_open(struct inode *inode, struct file *file);
+static int ftrace_event_show_triggers_open(struct inode *inode, struct file *file);
 static int ftrace_event_set_pid_open(struct inode *inode, struct file *file);
 static int ftrace_event_set_npid_open(struct inode *inode, struct file *file);
 static int ftrace_event_release(struct inode *inode, struct file *file);
@@ -2507,6 +2601,20 @@ static const struct seq_operations show_set_event_seq_ops = {
 	.stop = s_stop,
 };
 
+static const struct seq_operations show_show_event_filters_seq_ops = {
+	.start = t_start,
+	.next = t_next,
+	.show = t_show_filters,
+	.stop = t_stop,
+};
+
+static const struct seq_operations show_show_event_triggers_seq_ops = {
+	.start = t_start,
+	.next = t_next,
+	.show = t_show_triggers,
+	.stop = t_stop,
+};
+
 static const struct seq_operations show_set_pid_seq_ops = {
 	.start = p_start,
 	.next = p_next,
@@ -2536,6 +2644,20 @@ static const struct file_operations ftrace_set_event_fops = {
 	.release = ftrace_event_release,
 };
 
+static const struct file_operations ftrace_show_event_filters_fops = {
+	.open = ftrace_event_show_filters_open,
+	.read = seq_read,
+	.llseek = seq_lseek,
+	.release = seq_release,
+};
+
+static const struct file_operations ftrace_show_event_triggers_fops = {
+	.open = ftrace_event_show_triggers_open,
+	.read = seq_read,
+	.llseek = seq_lseek,
+	.release = seq_release,
+};
+
 static const struct file_operations ftrace_set_event_pid_fops = {
 	.open = ftrace_event_set_pid_open,
 	.read = seq_read,
@@ -2680,6 +2802,34 @@ ftrace_event_set_open(struct inode *inode, struct file *file)
 	return ret;
 }
 
+/**
+ * ftrace_event_show_filters_open - open interface for set_event_filters
+ * @inode: The inode of the file
+ * @file: The file being opened
+ *
+ * Connects the set_event_filters file to the sequence operations
+ * required to iterate over and display active event filters.
+ */
+static int
+ftrace_event_show_filters_open(struct inode *inode, struct file *file)
+{
+	return ftrace_event_open(inode, file, &show_show_event_filters_seq_ops);
+}
+
+/**
+ * ftrace_event_show_triggers_open - open interface for show_event_triggers
+ * @inode: The inode of the file
+ * @file: The file being opened
+ *
+ * Connects the show_event_triggers file to the sequence operations
+ * required to iterate over and display active event triggers.
+ */
+static int
+ftrace_event_show_triggers_open(struct inode *inode, struct file *file)
+{
+	return ftrace_event_open(inode, file, &show_show_event_triggers_seq_ops);
+}
+
 static int
 ftrace_event_set_pid_open(struct inode *inode, struct file *file)
 {
@@ -3963,11 +4113,6 @@ void trace_put_event_file(struct trace_event_file *file)
 EXPORT_SYMBOL_GPL(trace_put_event_file);
 
 #ifdef CONFIG_DYNAMIC_FTRACE
-
-/* Avoid typos */
-#define ENABLE_EVENT_STR	"enable_event"
-#define DISABLE_EVENT_STR	"disable_event"
-
 struct event_probe_data {
 	struct trace_event_file	*file;
 	unsigned long			count;
@@ -4400,6 +4545,12 @@ create_event_toplevel_files(struct dentry *parent, struct trace_array *tr)
 	if (!entry)
 		return -ENOMEM;
 
+	trace_create_file("show_event_filters", TRACE_MODE_READ, parent, tr,
+			  &ftrace_show_event_filters_fops);
+
+	trace_create_file("show_event_triggers", TRACE_MODE_READ, parent, tr,
+			  &ftrace_show_event_triggers_fops);
+
 	nr_entries = ARRAY_SIZE(events_entries);
 
 	e_events = eventfs_create_events_dir("events", parent, events_entries,
diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index 385af8405392..7001e34476ee 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -1375,7 +1375,7 @@ static void free_filter_list_tasks(struct rcu_head *rhp)
 	struct filter_head *filter_list = container_of(rhp, struct filter_head, rcu);
 
 	INIT_RCU_WORK(&filter_list->rwork, free_filter_list_work);
-	queue_rcu_work(system_wq, &filter_list->rwork);
+	queue_rcu_work(system_dfl_wq, &filter_list->rwork);
 }
 
 /*
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index c97bb2fda5c0..e6f449f53afc 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -105,38 +105,44 @@ enum field_op_id {
 	FIELD_OP_MULT,
 };
 
+#define FIELD_FUNCS					\
+	C(NOP,			"nop"),			\
+	C(VAR_REF,		"var_ref"),		\
+	C(COUNTER,		"counter"),		\
+	C(CONST,		"const"),		\
+	C(LOG2,			"log2"),		\
+	C(BUCKET,		"bucket"),		\
+	C(TIMESTAMP,		"timestamp"),		\
+	C(CPU,			"cpu"),			\
+	C(COMM,			"comm"),		\
+	C(STRING,		"string"),		\
+	C(DYNSTRING,		"dynstring"),		\
+	C(RELDYNSTRING,		"reldynstring"),	\
+	C(PSTRING,		"pstring"),		\
+	C(S64,			"s64"),			\
+	C(U64,			"u64"),			\
+	C(S32,			"s32"),			\
+	C(U32,			"u32"),			\
+	C(S16,			"s16"),			\
+	C(U16,			"u16"),			\
+	C(S8,			"s8"),			\
+	C(U8,			"u8"),			\
+	C(UMINUS,		"uminus"),		\
+	C(MINUS,		"minus"),		\
+	C(PLUS,			"plus"),		\
+	C(DIV,			"div"),			\
+	C(MULT,			"mult"),		\
+	C(DIV_POWER2,		"div_power2"),		\
+	C(DIV_NOT_POWER2,	"div_not_power2"),	\
+	C(DIV_MULT_SHIFT,	"div_mult_shift"),	\
+	C(EXECNAME,		"execname"),		\
+	C(STACK,		"stack"),
+
+#undef C
+#define C(a, b)		HIST_FIELD_FN_##a
+
 enum hist_field_fn {
-	HIST_FIELD_FN_NOP,
-	HIST_FIELD_FN_VAR_REF,
-	HIST_FIELD_FN_COUNTER,
-	HIST_FIELD_FN_CONST,
-	HIST_FIELD_FN_LOG2,
-	HIST_FIELD_FN_BUCKET,
-	HIST_FIELD_FN_TIMESTAMP,
-	HIST_FIELD_FN_CPU,
-	HIST_FIELD_FN_COMM,
-	HIST_FIELD_FN_STRING,
-	HIST_FIELD_FN_DYNSTRING,
-	HIST_FIELD_FN_RELDYNSTRING,
-	HIST_FIELD_FN_PSTRING,
-	HIST_FIELD_FN_S64,
-	HIST_FIELD_FN_U64,
-	HIST_FIELD_FN_S32,
-	HIST_FIELD_FN_U32,
-	HIST_FIELD_FN_S16,
-	HIST_FIELD_FN_U16,
-	HIST_FIELD_FN_S8,
-	HIST_FIELD_FN_U8,
-	HIST_FIELD_FN_UMINUS,
-	HIST_FIELD_FN_MINUS,
-	HIST_FIELD_FN_PLUS,
-	HIST_FIELD_FN_DIV,
-	HIST_FIELD_FN_MULT,
-	HIST_FIELD_FN_DIV_POWER2,
-	HIST_FIELD_FN_DIV_NOT_POWER2,
-	HIST_FIELD_FN_DIV_MULT_SHIFT,
-	HIST_FIELD_FN_EXECNAME,
-	HIST_FIELD_FN_STACK,
+	FIELD_FUNCS
 };
 
 /*
@@ -3157,7 +3163,7 @@ static inline void __update_field_vars(struct tracing_map_elt *elt,
 	u64 var_val;
 
 	/* Make sure stacktrace can fit in the string variable length */
-	BUILD_BUG_ON((HIST_STACKTRACE_DEPTH + 1) * sizeof(long) >= STR_VAR_LEN_MAX);
+	BUILD_BUG_ON((HIST_STACKTRACE_DEPTH + 1) * sizeof(long) > STR_VAR_LEN_MAX);
 
 	for (i = 0, j = field_var_str_start; i < n_field_vars; i++) {
 		struct field_var *field_var = field_vars[i];
@@ -5854,6 +5860,12 @@ const struct file_operations event_hist_fops = {
 };
 
 #ifdef CONFIG_HIST_TRIGGERS_DEBUG
+
+#undef C
+#define C(a, b)		b
+
+static const char * const field_funcs[] = { FIELD_FUNCS };
+
 static void hist_field_debug_show_flags(struct seq_file *m,
 					unsigned long flags)
 {
@@ -5918,6 +5930,7 @@ static int hist_field_debug_show(struct seq_file *m,
 	seq_printf(m, "      type: %s\n", field->type);
 	seq_printf(m, "      size: %u\n", field->size);
 	seq_printf(m, "      is_signed: %u\n", field->is_signed);
+	seq_printf(m, "      function: hist_field_%s()\n", field_funcs[field->fn_num]);
 
 	return 0;
 }
@@ -6518,6 +6531,26 @@ static bool existing_hist_update_only(char *glob,
 	return updated;
 }
 
+/*
+ * Set or disable using the per CPU trace_buffer_event when possible.
+ */
+static int tracing_set_filter_buffering(struct trace_array *tr, bool set)
+{
+	guard(mutex)(&trace_types_lock);
+
+	if (set && tr->no_filter_buffering_ref++)
+		return 0;
+
+	if (!set) {
+		if (WARN_ON_ONCE(!tr->no_filter_buffering_ref))
+			return -EINVAL;
+
+		--tr->no_filter_buffering_ref;
+	}
+
+	return 0;
+}
+
 static int hist_register_trigger(char *glob,
 				 struct event_trigger_data *data,
 				 struct trace_event_file *file)
@@ -6907,11 +6940,9 @@ static int event_hist_trigger_parse(struct event_command *cmd_ops,
  out_unreg:
 	event_trigger_unregister(cmd_ops, file, glob+1, trigger_data);
  out_free:
-	event_trigger_reset_filter(cmd_ops, trigger_data);
-
 	remove_hist_vars(hist_data);
 
-	kfree(trigger_data);
+	trigger_data_free(trigger_data);
 
 	destroy_hist_data(hist_data);
 	goto out;
diff --git a/kernel/trace/trace_events_synth.c b/kernel/trace/trace_events_synth.c
index 45c187e77e21..ce42fbf16f4a 100644
--- a/kernel/trace/trace_events_synth.c
+++ b/kernel/trace/trace_events_synth.c
@@ -499,9 +499,9 @@ static unsigned int trace_stack(struct synth_trace_event *entry,
 	return len;
 }
 
-static notrace void trace_event_raw_event_synth(void *__data,
-						u64 *var_ref_vals,
-						unsigned int *var_ref_idx)
+static void trace_event_raw_event_synth(void *__data,
+					u64 *var_ref_vals,
+					unsigned int *var_ref_idx)
 {
 	unsigned int i, n_u64, val_idx, len, data_size = 0;
 	struct trace_event_file *trace_file = __data;
diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c
index 06b75bcfc7b8..7fa26327c9c7 100644
--- a/kernel/trace/trace_events_trigger.c
+++ b/kernel/trace/trace_events_trigger.c
@@ -1347,18 +1347,13 @@ traceon_trigger(struct event_trigger_data *data,
 {
 	struct trace_event_file *file = data->private_data;
 
-	if (file) {
-		if (tracer_tracing_is_on(file->tr))
-			return;
-
-		tracer_tracing_on(file->tr);
+	if (WARN_ON_ONCE(!file))
 		return;
-	}
 
-	if (tracing_is_on())
+	if (tracer_tracing_is_on(file->tr))
 		return;
 
-	tracing_on();
+	tracer_tracing_on(file->tr);
 }
 
 static bool
@@ -1368,13 +1363,11 @@ traceon_count_func(struct event_trigger_data *data,
 {
 	struct trace_event_file *file = data->private_data;
 
-	if (file) {
-		if (tracer_tracing_is_on(file->tr))
-			return false;
-	} else {
-		if (tracing_is_on())
-			return false;
-	}
+	if (WARN_ON_ONCE(!file))
+		return false;
+
+	if (tracer_tracing_is_on(file->tr))
+		return false;
 
 	if (!data->count)
 		return false;
@@ -1392,18 +1385,13 @@ traceoff_trigger(struct event_trigger_data *data,
 {
 	struct trace_event_file *file = data->private_data;
 
-	if (file) {
-		if (!tracer_tracing_is_on(file->tr))
-			return;
-
-		tracer_tracing_off(file->tr);
+	if (WARN_ON_ONCE(!file))
 		return;
-	}
 
-	if (!tracing_is_on())
+	if (!tracer_tracing_is_on(file->tr))
 		return;
 
-	tracing_off();
+	tracer_tracing_off(file->tr);
 }
 
 static bool
@@ -1413,13 +1401,11 @@ traceoff_count_func(struct event_trigger_data *data,
 {
 	struct trace_event_file *file = data->private_data;
 
-	if (file) {
-		if (!tracer_tracing_is_on(file->tr))
-			return false;
-	} else {
-		if (!tracing_is_on())
-			return false;
-	}
+	if (WARN_ON_ONCE(!file))
+		return false;
+
+	if (!tracer_tracing_is_on(file->tr))
+		return false;
 
 	if (!data->count)
 		return false;
@@ -1481,10 +1467,10 @@ snapshot_trigger(struct event_trigger_data *data,
 {
 	struct trace_event_file *file = data->private_data;
 
-	if (file)
-		tracing_snapshot_instance(file->tr);
-	else
-		tracing_snapshot();
+	if (WARN_ON_ONCE(!file))
+		return;
+
+	tracing_snapshot_instance(file->tr);
 }
 
 static int
@@ -1570,10 +1556,10 @@ stacktrace_trigger(struct event_trigger_data *data,
 {
 	struct trace_event_file *file = data->private_data;
 
-	if (file)
-		__trace_stack(file->tr, tracing_gen_ctx_dec(), STACK_SKIP);
-	else
-		trace_dump_stack(STACK_SKIP);
+	if (WARN_ON_ONCE(!file))
+		return;
+
+	__trace_stack(file->tr, tracing_gen_ctx_dec(), STACK_SKIP);
 }
 
 static int
diff --git a/kernel/trace/trace_hwlat.c b/kernel/trace/trace_hwlat.c
index 2f7b94e98317..3fe274b84f1c 100644
--- a/kernel/trace/trace_hwlat.c
+++ b/kernel/trace/trace_hwlat.c
@@ -102,9 +102,9 @@ struct hwlat_sample {
 /* keep the global state somewhere. */
 static struct hwlat_data {
 
-	struct mutex lock;		/* protect changes */
+	struct mutex	lock;		/* protect changes */
 
-	u64	count;			/* total since reset */
+	atomic64_t	count;		/* total since reset */
 
 	u64	sample_window;		/* total sampling window (on+off) */
 	u64	sample_width;		/* active sampling portion of window */
@@ -193,8 +193,7 @@ void trace_hwlat_callback(bool enter)
  * get_sample - sample the CPU TSC and look for likely hardware latencies
  *
  * Used to repeatedly capture the CPU TSC (or similar), looking for potential
- * hardware-induced latency. Called with interrupts disabled and with
- * hwlat_data.lock held.
+ * hardware-induced latency. Called with interrupts disabled.
  */
 static int get_sample(void)
 {
@@ -204,6 +203,7 @@ static int get_sample(void)
 	time_type start, t1, t2, last_t2;
 	s64 diff, outer_diff, total, last_total = 0;
 	u64 sample = 0;
+	u64 sample_width = READ_ONCE(hwlat_data.sample_width);
 	u64 thresh = tracing_thresh;
 	u64 outer_sample = 0;
 	int ret = -1;
@@ -267,7 +267,7 @@ static int get_sample(void)
 		if (diff > sample)
 			sample = diff; /* only want highest value */
 
-	} while (total <= hwlat_data.sample_width);
+	} while (total <= sample_width);
 
 	barrier(); /* finish the above in the view for NMIs */
 	trace_hwlat_callback_enabled = false;
@@ -285,8 +285,7 @@ static int get_sample(void)
 		if (kdata->nmi_total_ts)
 			do_div(kdata->nmi_total_ts, NSEC_PER_USEC);
 
-		hwlat_data.count++;
-		s.seqnum = hwlat_data.count;
+		s.seqnum = atomic64_inc_return(&hwlat_data.count);
 		s.duration = sample;
 		s.outer_duration = outer_sample;
 		s.nmi_total_ts = kdata->nmi_total_ts;
@@ -832,7 +831,7 @@ static int hwlat_tracer_init(struct trace_array *tr)
 
 	hwlat_trace = tr;
 
-	hwlat_data.count = 0;
+	atomic64_set(&hwlat_data.count, 0);
 	tr->max_latency = 0;
 	save_tracing_thresh = tracing_thresh;
 
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 9953506370a5..061658518605 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -2048,6 +2048,10 @@ static __init int init_kprobe_trace(void)
 	trace_create_file("kprobe_profile", TRACE_MODE_READ,
 			  NULL, NULL, &kprobe_profile_ops);
 
+	/* If no 'kprobe_event=' cmd is provided, return directly. */
+	if (kprobe_boot_events_buf[0] == '\0')
+		return 0;
+
 	setup_boot_kprobe_events();
 
 	return 0;
@@ -2079,7 +2083,7 @@ static __init int kprobe_trace_self_tests_init(void)
 	struct trace_kprobe *tk;
 	struct trace_event_file *file;
 
-	if (tracing_is_disabled())
+	if (unlikely(tracing_disabled))
 		return -ENODEV;
 
 	if (tracing_selftest_disabled)
diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index cc2d3306bb60..1996d7aba038 100644
--- a/kernel/trace/trace_output.c
+++ b/kernel/trace/trace_output.c
@@ -194,13 +194,37 @@ trace_print_symbols_seq_u64(struct trace_seq *p, unsigned long long val,
 EXPORT_SYMBOL(trace_print_symbols_seq_u64);
 #endif
 
+/**
+ * trace_print_bitmask_seq - print a bitmask to a sequence buffer
+ * @iter: The trace iterator for the current event instance
+ * @bitmask_ptr: The pointer to the bitmask data
+ * @bitmask_size: The size of the bitmask in bytes
+ *
+ * Prints a bitmask into a sequence buffer as either a hex string or a
+ * human-readable range list, depending on the instance's "bitmask-list"
+ * trace option. The bitmask is formatted into the iterator's temporary
+ * scratchpad rather than the primary sequence buffer. This avoids
+ * duplication and pointer-collision issues when the returned string is
+ * processed by a "%s" specifier in a TP_printk() macro.
+ *
+ * Returns a pointer to the formatted string within the temporary buffer.
+ */
 const char *
-trace_print_bitmask_seq(struct trace_seq *p, void *bitmask_ptr,
+trace_print_bitmask_seq(struct trace_iterator *iter, void *bitmask_ptr,
 			unsigned int bitmask_size)
 {
-	const char *ret = trace_seq_buffer_ptr(p);
+	struct trace_seq *p = &iter->tmp_seq;
+	const struct trace_array *tr = iter->tr;
+	const char *ret;
+
+	trace_seq_init(p);
+	ret = trace_seq_buffer_ptr(p);
+
+	if (tr->trace_flags & TRACE_ITER(BITMASK_LIST))
+		trace_seq_bitmask_list(p, bitmask_ptr, bitmask_size * 8);
+	else
+		trace_seq_bitmask(p, bitmask_ptr, bitmask_size * 8);
 
-	trace_seq_bitmask(p, bitmask_ptr, bitmask_size * 8);
 	trace_seq_putc(p, 0);
 
 	return ret;
diff --git a/kernel/trace/trace_pid.c b/kernel/trace/trace_pid.c
new file mode 100644
index 000000000000..7127c8de4174
--- /dev/null
+++ b/kernel/trace/trace_pid.c
@@ -0,0 +1,246 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include "trace.h"
+
+/**
+ * trace_find_filtered_pid - check if a pid exists in a filtered_pid list
+ * @filtered_pids: The list of pids to check
+ * @search_pid: The PID to find in @filtered_pids
+ *
+ * Returns true if @search_pid is found in @filtered_pids, and false otherwise.
+ */
+bool
+trace_find_filtered_pid(struct trace_pid_list *filtered_pids, pid_t search_pid)
+{
+	return trace_pid_list_is_set(filtered_pids, search_pid);
+}
+
+/**
+ * trace_ignore_this_task - should a task be ignored for tracing
+ * @filtered_pids: The list of pids to check
+ * @filtered_no_pids: The list of pids not to be traced
+ * @task: The task that should be ignored if not filtered
+ *
+ * Checks if @task should be traced or not from @filtered_pids.
+ * Returns true if @task should *NOT* be traced.
+ * Returns false if @task should be traced.
+ */
+bool
+trace_ignore_this_task(struct trace_pid_list *filtered_pids,
+		       struct trace_pid_list *filtered_no_pids,
+		       struct task_struct *task)
+{
+	/*
+	 * If filtered_no_pids is not empty, and the task's pid is listed
+	 * in filtered_no_pids, then return true.
+	 * Otherwise, if filtered_pids is empty, that means we can
+	 * trace all tasks. If it has content, then only trace pids
+	 * within filtered_pids.
+	 */
+
+	return (filtered_pids &&
+		!trace_find_filtered_pid(filtered_pids, task->pid)) ||
+		(filtered_no_pids &&
+		 trace_find_filtered_pid(filtered_no_pids, task->pid));
+}
+
+/**
+ * trace_filter_add_remove_task - Add or remove a task from a pid_list
+ * @pid_list: The list to modify
+ * @self: The current task for fork or NULL for exit
+ * @task: The task to add or remove
+ *
+ * If adding a task, if @self is defined, the task is only added if @self
+ * is also included in @pid_list. This happens on fork and tasks should
+ * only be added when the parent is listed. If @self is NULL, then the
+ * @task pid will be removed from the list, which would happen on exit
+ * of a task.
+ */
+void trace_filter_add_remove_task(struct trace_pid_list *pid_list,
+				  struct task_struct *self,
+				  struct task_struct *task)
+{
+	if (!pid_list)
+		return;
+
+	/* For forks, we only add if the forking task is listed */
+	if (self) {
+		if (!trace_find_filtered_pid(pid_list, self->pid))
+			return;
+	}
+
+	/* "self" is set for forks, and NULL for exits */
+	if (self)
+		trace_pid_list_set(pid_list, task->pid);
+	else
+		trace_pid_list_clear(pid_list, task->pid);
+}
+
+/**
+ * trace_pid_next - Used for seq_file to get to the next pid of a pid_list
+ * @pid_list: The pid list to show
+ * @v: The last pid that was shown (+1 the actual pid to let zero be displayed)
+ * @pos: The position of the file
+ *
+ * This is used by the seq_file "next" operation to iterate the pids
+ * listed in a trace_pid_list structure.
+ *
+ * Returns the pid+1 as we want to display pid of zero, but NULL would
+ * stop the iteration.
+ */
+void *trace_pid_next(struct trace_pid_list *pid_list, void *v, loff_t *pos)
+{
+	long pid = (unsigned long)v;
+	unsigned int next;
+
+	(*pos)++;
+
+	/* pid already is +1 of the actual previous bit */
+	if (trace_pid_list_next(pid_list, pid, &next) < 0)
+		return NULL;
+
+	pid = next;
+
+	/* Return pid + 1 to allow zero to be represented */
+	return (void *)(pid + 1);
+}
+
+/**
+ * trace_pid_start - Used for seq_file to start reading pid lists
+ * @pid_list: The pid list to show
+ * @pos: The position of the file
+ *
+ * This is used by seq_file "start" operation to start the iteration
+ * of listing pids.
+ *
+ * Returns the pid+1 as we want to display pid of zero, but NULL would
+ * stop the iteration.
+ */
+void *trace_pid_start(struct trace_pid_list *pid_list, loff_t *pos)
+{
+	unsigned long pid;
+	unsigned int first;
+	loff_t l = 0;
+
+	if (trace_pid_list_first(pid_list, &first) < 0)
+		return NULL;
+
+	pid = first;
+
+	/* Return pid + 1 so that zero can be the exit value */
+	for (pid++; pid && l < *pos;
+	     pid = (unsigned long)trace_pid_next(pid_list, (void *)pid, &l))
+		;
+	return (void *)pid;
+}
+
+/**
+ * trace_pid_show - show the current pid in seq_file processing
+ * @m: The seq_file structure to write into
+ * @v: A void pointer of the pid (+1) value to display
+ *
+ * Can be directly used by seq_file operations to display the current
+ * pid value.
+ */
+int trace_pid_show(struct seq_file *m, void *v)
+{
+	unsigned long pid = (unsigned long)v - 1;
+
+	seq_printf(m, "%lu\n", pid);
+	return 0;
+}
+
+/* 128 should be much more than enough */
+#define PID_BUF_SIZE		127
+
+int trace_pid_write(struct trace_pid_list *filtered_pids,
+		    struct trace_pid_list **new_pid_list,
+		    const char __user *ubuf, size_t cnt)
+{
+	struct trace_pid_list *pid_list;
+	struct trace_parser parser;
+	unsigned long val;
+	int nr_pids = 0;
+	ssize_t read = 0;
+	ssize_t ret;
+	loff_t pos;
+	pid_t pid;
+
+	if (trace_parser_get_init(&parser, PID_BUF_SIZE + 1))
+		return -ENOMEM;
+
+	/*
+	 * Always recreate a new array. The write is an all or nothing
+	 * operation. Always create a new array when adding new pids by
+	 * the user. If the operation fails, then the current list is
+	 * not modified.
+	 */
+	pid_list = trace_pid_list_alloc();
+	if (!pid_list) {
+		trace_parser_put(&parser);
+		return -ENOMEM;
+	}
+
+	if (filtered_pids) {
+		/* copy the current bits to the new max */
+		ret = trace_pid_list_first(filtered_pids, &pid);
+		while (!ret) {
+			ret = trace_pid_list_set(pid_list, pid);
+			if (ret < 0)
+				goto out;
+
+			ret = trace_pid_list_next(filtered_pids, pid + 1, &pid);
+			nr_pids++;
+		}
+	}
+
+	ret = 0;
+	while (cnt > 0) {
+
+		pos = 0;
+
+		ret = trace_get_user(&parser, ubuf, cnt, &pos);
+		if (ret < 0)
+			break;
+
+		read += ret;
+		ubuf += ret;
+		cnt -= ret;
+
+		if (!trace_parser_loaded(&parser))
+			break;
+
+		ret = -EINVAL;
+		if (kstrtoul(parser.buffer, 0, &val))
+			break;
+
+		pid = (pid_t)val;
+
+		if (trace_pid_list_set(pid_list, pid) < 0) {
+			ret = -1;
+			break;
+		}
+		nr_pids++;
+
+		trace_parser_clear(&parser);
+		ret = 0;
+	}
+ out:
+	trace_parser_put(&parser);
+
+	if (ret < 0) {
+		trace_pid_list_free(pid_list);
+		return ret;
+	}
+
+	if (!nr_pids) {
+		/* Cleared the list of pids */
+		trace_pid_list_free(pid_list);
+		pid_list = NULL;
+	}
+
+	*new_pid_list = pid_list;
+
+	return read;
+}
+
diff --git a/kernel/trace/trace_printk.c b/kernel/trace/trace_printk.c
index 29f6e95439b6..6a29e4350b55 100644
--- a/kernel/trace/trace_printk.c
+++ b/kernel/trace/trace_printk.c
@@ -376,6 +376,436 @@ static const struct file_operations ftrace_formats_fops = {
 	.release = seq_release,
 };
 
+static __always_inline bool printk_binsafe(struct trace_array *tr)
+{
+	/*
+	 * The binary format of traceprintk can cause a crash if used
+	 * by a buffer from another boot. Force the use of the
+	 * non binary version of trace_printk if the trace_printk
+	 * buffer is a boot mapped ring buffer.
+	 */
+	return !(tr->flags & TRACE_ARRAY_FL_BOOT);
+}
+
+int __trace_array_puts(struct trace_array *tr, unsigned long ip,
+		       const char *str, int size)
+{
+	struct ring_buffer_event *event;
+	struct trace_buffer *buffer;
+	struct print_entry *entry;
+	unsigned int trace_ctx;
+	int alloc;
+
+	if (!(tr->trace_flags & TRACE_ITER(PRINTK)))
+		return 0;
+
+	if (unlikely(tracing_selftest_running &&
+		     (tr->flags & TRACE_ARRAY_FL_GLOBAL)))
+		return 0;
+
+	if (unlikely(tracing_disabled))
+		return 0;
+
+	alloc = sizeof(*entry) + size + 2; /* possible \n added */
+
+	trace_ctx = tracing_gen_ctx();
+	buffer = tr->array_buffer.buffer;
+	guard(ring_buffer_nest)(buffer);
+	event = __trace_buffer_lock_reserve(buffer, TRACE_PRINT, alloc,
+					    trace_ctx);
+	if (!event)
+		return 0;
+
+	entry = ring_buffer_event_data(event);
+	entry->ip = ip;
+
+	memcpy(&entry->buf, str, size);
+
+	/* Add a newline if necessary */
+	if (entry->buf[size - 1] != '\n') {
+		entry->buf[size] = '\n';
+		entry->buf[size + 1] = '\0';
+	} else
+		entry->buf[size] = '\0';
+
+	__buffer_unlock_commit(buffer, event);
+	ftrace_trace_stack(tr, buffer, trace_ctx, 4, NULL);
+	return size;
+}
+EXPORT_SYMBOL_GPL(__trace_array_puts);
+
+/**
+ * __trace_puts - write a constant string into the trace buffer.
+ * @ip:	   The address of the caller
+ * @str:   The constant string to write
+ */
+int __trace_puts(unsigned long ip, const char *str)
+{
+	return __trace_array_puts(printk_trace, ip, str, strlen(str));
+}
+EXPORT_SYMBOL_GPL(__trace_puts);
+
+/**
+ * __trace_bputs - write the pointer to a constant string into trace buffer
+ * @ip:	   The address of the caller
+ * @str:   The constant string to write to the buffer to
+ */
+int __trace_bputs(unsigned long ip, const char *str)
+{
+	struct trace_array *tr = READ_ONCE(printk_trace);
+	struct ring_buffer_event *event;
+	struct trace_buffer *buffer;
+	struct bputs_entry *entry;
+	unsigned int trace_ctx;
+	int size = sizeof(struct bputs_entry);
+
+	if (!printk_binsafe(tr))
+		return __trace_puts(ip, str);
+
+	if (!(tr->trace_flags & TRACE_ITER(PRINTK)))
+		return 0;
+
+	if (unlikely(tracing_selftest_running || tracing_disabled))
+		return 0;
+
+	trace_ctx = tracing_gen_ctx();
+	buffer = tr->array_buffer.buffer;
+
+	guard(ring_buffer_nest)(buffer);
+	event = __trace_buffer_lock_reserve(buffer, TRACE_BPUTS, size,
+					    trace_ctx);
+	if (!event)
+		return 0;
+
+	entry = ring_buffer_event_data(event);
+	entry->ip			= ip;
+	entry->str			= str;
+
+	__buffer_unlock_commit(buffer, event);
+	ftrace_trace_stack(tr, buffer, trace_ctx, 4, NULL);
+
+	return 1;
+}
+EXPORT_SYMBOL_GPL(__trace_bputs);
+
+/* created for use with alloc_percpu */
+struct trace_buffer_struct {
+	int nesting;
+	char buffer[4][TRACE_BUF_SIZE];
+};
+
+static struct trace_buffer_struct __percpu *trace_percpu_buffer;
+
+/*
+ * This allows for lockless recording.  If we're nested too deeply, then
+ * this returns NULL.
+ */
+static char *get_trace_buf(void)
+{
+	struct trace_buffer_struct *buffer = this_cpu_ptr(trace_percpu_buffer);
+
+	if (!trace_percpu_buffer || buffer->nesting >= 4)
+		return NULL;
+
+	buffer->nesting++;
+
+	/* Interrupts must see nesting incremented before we use the buffer */
+	barrier();
+	return &buffer->buffer[buffer->nesting - 1][0];
+}
+
+static void put_trace_buf(void)
+{
+	/* Don't let the decrement of nesting leak before this */
+	barrier();
+	this_cpu_dec(trace_percpu_buffer->nesting);
+}
+
+static int alloc_percpu_trace_buffer(void)
+{
+	struct trace_buffer_struct __percpu *buffers;
+
+	if (trace_percpu_buffer)
+		return 0;
+
+	buffers = alloc_percpu(struct trace_buffer_struct);
+	if (MEM_FAIL(!buffers, "Could not allocate percpu trace_printk buffer"))
+		return -ENOMEM;
+
+	trace_percpu_buffer = buffers;
+	return 0;
+}
+
+static int buffers_allocated;
+
+void trace_printk_init_buffers(void)
+{
+	if (buffers_allocated)
+		return;
+
+	if (alloc_percpu_trace_buffer())
+		return;
+
+	/* trace_printk() is for debug use only. Don't use it in production. */
+
+	pr_warn("\n");
+	pr_warn("**********************************************************\n");
+	pr_warn("**   NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE   **\n");
+	pr_warn("**                                                      **\n");
+	pr_warn("** trace_printk() being used. Allocating extra memory.  **\n");
+	pr_warn("**                                                      **\n");
+	pr_warn("** This means that this is a DEBUG kernel and it is     **\n");
+	pr_warn("** unsafe for production use.                           **\n");
+	pr_warn("**                                                      **\n");
+	pr_warn("** If you see this message and you are not debugging    **\n");
+	pr_warn("** the kernel, report this immediately to your vendor!  **\n");
+	pr_warn("**                                                      **\n");
+	pr_warn("**   NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE   **\n");
+	pr_warn("**********************************************************\n");
+
+	/* Expand the buffers to set size */
+	if (tracing_update_buffers(NULL) < 0)
+		pr_err("Failed to expand tracing buffers for trace_printk() calls\n");
+	else
+		buffers_allocated = 1;
+
+	/*
+	 * trace_printk_init_buffers() can be called by modules.
+	 * If that happens, then we need to start cmdline recording
+	 * directly here.
+	 */
+	if (system_state == SYSTEM_RUNNING)
+		tracing_start_cmdline_record();
+}
+EXPORT_SYMBOL_GPL(trace_printk_init_buffers);
+
+void trace_printk_start_comm(void)
+{
+	/* Start tracing comms if trace printk is set */
+	if (!buffers_allocated)
+		return;
+	tracing_start_cmdline_record();
+}
+
+void trace_printk_start_stop_comm(int enabled)
+{
+	if (!buffers_allocated)
+		return;
+
+	if (enabled)
+		tracing_start_cmdline_record();
+	else
+		tracing_stop_cmdline_record();
+}
+
+/**
+ * trace_vbprintk - write binary msg to tracing buffer
+ * @ip:    The address of the caller
+ * @fmt:   The string format to write to the buffer
+ * @args:  Arguments for @fmt
+ */
+int trace_vbprintk(unsigned long ip, const char *fmt, va_list args)
+{
+	struct ring_buffer_event *event;
+	struct trace_buffer *buffer;
+	struct trace_array *tr = READ_ONCE(printk_trace);
+	struct bprint_entry *entry;
+	unsigned int trace_ctx;
+	char *tbuffer;
+	int len = 0, size;
+
+	if (!printk_binsafe(tr))
+		return trace_vprintk(ip, fmt, args);
+
+	if (unlikely(tracing_selftest_running || tracing_disabled))
+		return 0;
+
+	/* Don't pollute graph traces with trace_vprintk internals */
+	pause_graph_tracing();
+
+	trace_ctx = tracing_gen_ctx();
+	guard(preempt_notrace)();
+
+	tbuffer = get_trace_buf();
+	if (!tbuffer) {
+		len = 0;
+		goto out_nobuffer;
+	}
+
+	len = vbin_printf((u32 *)tbuffer, TRACE_BUF_SIZE/sizeof(int), fmt, args);
+
+	if (len > TRACE_BUF_SIZE/sizeof(int) || len < 0)
+		goto out_put;
+
+	size = sizeof(*entry) + sizeof(u32) * len;
+	buffer = tr->array_buffer.buffer;
+	scoped_guard(ring_buffer_nest, buffer) {
+		event = __trace_buffer_lock_reserve(buffer, TRACE_BPRINT, size,
+						    trace_ctx);
+		if (!event)
+			goto out_put;
+		entry = ring_buffer_event_data(event);
+		entry->ip			= ip;
+		entry->fmt			= fmt;
+
+		memcpy(entry->buf, tbuffer, sizeof(u32) * len);
+		__buffer_unlock_commit(buffer, event);
+		ftrace_trace_stack(tr, buffer, trace_ctx, 6, NULL);
+	}
+out_put:
+	put_trace_buf();
+
+out_nobuffer:
+	unpause_graph_tracing();
+
+	return len;
+}
+EXPORT_SYMBOL_GPL(trace_vbprintk);
+
+static __printf(3, 0)
+int __trace_array_vprintk(struct trace_buffer *buffer,
+			  unsigned long ip, const char *fmt, va_list args)
+{
+	struct ring_buffer_event *event;
+	int len = 0, size;
+	struct print_entry *entry;
+	unsigned int trace_ctx;
+	char *tbuffer;
+
+	if (unlikely(tracing_disabled))
+		return 0;
+
+	/* Don't pollute graph traces with trace_vprintk internals */
+	pause_graph_tracing();
+
+	trace_ctx = tracing_gen_ctx();
+	guard(preempt_notrace)();
+
+
+	tbuffer = get_trace_buf();
+	if (!tbuffer) {
+		len = 0;
+		goto out_nobuffer;
+	}
+
+	len = vscnprintf(tbuffer, TRACE_BUF_SIZE, fmt, args);
+
+	size = sizeof(*entry) + len + 1;
+	scoped_guard(ring_buffer_nest, buffer) {
+		event = __trace_buffer_lock_reserve(buffer, TRACE_PRINT, size,
+						    trace_ctx);
+		if (!event)
+			goto out;
+		entry = ring_buffer_event_data(event);
+		entry->ip = ip;
+
+		memcpy(&entry->buf, tbuffer, len + 1);
+		__buffer_unlock_commit(buffer, event);
+		ftrace_trace_stack(printk_trace, buffer, trace_ctx, 6, NULL);
+	}
+out:
+	put_trace_buf();
+
+out_nobuffer:
+	unpause_graph_tracing();
+
+	return len;
+}
+
+int trace_array_vprintk(struct trace_array *tr,
+			unsigned long ip, const char *fmt, va_list args)
+{
+	if (tracing_selftest_running && (tr->flags & TRACE_ARRAY_FL_GLOBAL))
+		return 0;
+
+	return __trace_array_vprintk(tr->array_buffer.buffer, ip, fmt, args);
+}
+
+/**
+ * trace_array_printk - Print a message to a specific instance
+ * @tr: The instance trace_array descriptor
+ * @ip: The instruction pointer that this is called from.
+ * @fmt: The format to print (printf format)
+ *
+ * If a subsystem sets up its own instance, they have the right to
+ * printk strings into their tracing instance buffer using this
+ * function. Note, this function will not write into the top level
+ * buffer (use trace_printk() for that), as writing into the top level
+ * buffer should only have events that can be individually disabled.
+ * trace_printk() is only used for debugging a kernel, and should not
+ * be ever incorporated in normal use.
+ *
+ * trace_array_printk() can be used, as it will not add noise to the
+ * top level tracing buffer.
+ *
+ * Note, trace_array_init_printk() must be called on @tr before this
+ * can be used.
+ */
+int trace_array_printk(struct trace_array *tr,
+		       unsigned long ip, const char *fmt, ...)
+{
+	int ret;
+	va_list ap;
+
+	if (!tr)
+		return -ENOENT;
+
+	/* This is only allowed for created instances */
+	if (tr->flags & TRACE_ARRAY_FL_GLOBAL)
+		return 0;
+
+	if (!(tr->trace_flags & TRACE_ITER(PRINTK)))
+		return 0;
+
+	va_start(ap, fmt);
+	ret = trace_array_vprintk(tr, ip, fmt, ap);
+	va_end(ap);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(trace_array_printk);
+
+/**
+ * trace_array_init_printk - Initialize buffers for trace_array_printk()
+ * @tr: The trace array to initialize the buffers for
+ *
+ * As trace_array_printk() only writes into instances, they are OK to
+ * have in the kernel (unlike trace_printk()). This needs to be called
+ * before trace_array_printk() can be used on a trace_array.
+ */
+int trace_array_init_printk(struct trace_array *tr)
+{
+	if (!tr)
+		return -ENOENT;
+
+	/* This is only allowed for created instances */
+	if (tr->flags & TRACE_ARRAY_FL_GLOBAL)
+		return -EINVAL;
+
+	return alloc_percpu_trace_buffer();
+}
+EXPORT_SYMBOL_GPL(trace_array_init_printk);
+
+int trace_array_printk_buf(struct trace_buffer *buffer,
+			   unsigned long ip, const char *fmt, ...)
+{
+	int ret;
+	va_list ap;
+
+	if (!(printk_trace->trace_flags & TRACE_ITER(PRINTK)))
+		return 0;
+
+	va_start(ap, fmt);
+	ret = __trace_array_vprintk(buffer, ip, fmt, ap);
+	va_end(ap);
+	return ret;
+}
+
+int trace_vprintk(unsigned long ip, const char *fmt, va_list args)
+{
+	return trace_array_vprintk(printk_trace, ip, fmt, args);
+}
+EXPORT_SYMBOL_GPL(trace_vprintk);
+
 static __init int init_trace_printk_function_export(void)
 {
 	int ret;
diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c
index d88c44f1dfa5..be53fe6fee6a 100644
--- a/kernel/trace/trace_selftest.c
+++ b/kernel/trace/trace_selftest.c
@@ -1225,7 +1225,7 @@ trace_selftest_startup_irqsoff(struct tracer *trace, struct trace_array *tr)
 	/* check both trace buffers */
 	ret = trace_test_buffer(&tr->array_buffer, NULL);
 	if (!ret)
-		ret = trace_test_buffer(&tr->max_buffer, &count);
+		ret = trace_test_buffer(&tr->snapshot_buffer, &count);
 	trace->reset(tr);
 	tracing_start();
 
@@ -1287,7 +1287,7 @@ trace_selftest_startup_preemptoff(struct tracer *trace, struct trace_array *tr)
 	/* check both trace buffers */
 	ret = trace_test_buffer(&tr->array_buffer, NULL);
 	if (!ret)
-		ret = trace_test_buffer(&tr->max_buffer, &count);
+		ret = trace_test_buffer(&tr->snapshot_buffer, &count);
 	trace->reset(tr);
 	tracing_start();
 
@@ -1355,7 +1355,7 @@ trace_selftest_startup_preemptirqsoff(struct tracer *trace, struct trace_array *
 	if (ret)
 		goto out;
 
-	ret = trace_test_buffer(&tr->max_buffer, &count);
+	ret = trace_test_buffer(&tr->snapshot_buffer, &count);
 	if (ret)
 		goto out;
 
@@ -1385,7 +1385,7 @@ trace_selftest_startup_preemptirqsoff(struct tracer *trace, struct trace_array *
 	if (ret)
 		goto out;
 
-	ret = trace_test_buffer(&tr->max_buffer, &count);
+	ret = trace_test_buffer(&tr->snapshot_buffer, &count);
 
 	if (!ret && !count) {
 		printk(KERN_CONT ".. no entries found ..");
@@ -1513,7 +1513,7 @@ trace_selftest_startup_wakeup(struct tracer *trace, struct trace_array *tr)
 	/* check both trace buffers */
 	ret = trace_test_buffer(&tr->array_buffer, NULL);
 	if (!ret)
-		ret = trace_test_buffer(&tr->max_buffer, &count);
+		ret = trace_test_buffer(&tr->snapshot_buffer, &count);
 
 
 	trace->reset(tr);
diff --git a/kernel/trace/trace_seq.c b/kernel/trace/trace_seq.c
index 32684ef4fb9d..85f6f10d107f 100644
--- a/kernel/trace/trace_seq.c
+++ b/kernel/trace/trace_seq.c
@@ -106,7 +106,7 @@ EXPORT_SYMBOL_GPL(trace_seq_printf);
  * Writes a ASCII representation of a bitmask string into @s.
  */
 void trace_seq_bitmask(struct trace_seq *s, const unsigned long *maskp,
-		      int nmaskbits)
+		       int nmaskbits)
 {
 	unsigned int save_len = s->seq.len;
 
@@ -125,6 +125,33 @@ void trace_seq_bitmask(struct trace_seq *s, const unsigned long *maskp,
 EXPORT_SYMBOL_GPL(trace_seq_bitmask);
 
 /**
+ * trace_seq_bitmask_list - write a bitmask array in its list representation
+ * @s:		trace sequence descriptor
+ * @maskp:	points to an array of unsigned longs that represent a bitmask
+ * @nmaskbits:	The number of bits that are valid in @maskp
+ *
+ * Writes a list representation (e.g., 0-3,5-7) of a bitmask string into @s.
+ */
+void trace_seq_bitmask_list(struct trace_seq *s, const unsigned long *maskp,
+		       int nmaskbits)
+{
+	unsigned int save_len = s->seq.len;
+
+	if (s->full)
+		return;
+
+	__trace_seq_init(s);
+
+	seq_buf_printf(&s->seq, "%*pbl", nmaskbits, maskp);
+
+	if (unlikely(seq_buf_has_overflowed(&s->seq))) {
+		s->seq.len = save_len;
+		s->full = 1;
+	}
+}
+EXPORT_SYMBOL_GPL(trace_seq_bitmask_list);
+
+/**
  * trace_seq_vprintf - sequence printing of trace information
  * @s: trace sequence descriptor
  * @fmt: printf format string