Merge tag 'trace-v6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull tracing updates from Steven Rostedt:

 - Add option traceoff_after_boot

   In order to debug kernel boot, it sometimes is helpful to enable
   tracing via the kernel command line. Unfortunately, by the time the
   login prompt appears, the trace is overwritten by the init process
   and other user space start up applications.

   Adding a "traceoff_after_boot" will disable tracing when the kernel
   passes control to init which will allow developers to be able to see
   the traces that occurred during boot.

 - Clean up the mmflags macros that display the GFP flags in trace
   events

   The macros to print the GFP flags for trace events had a bit of
   duplication. The code was restructured to remove duplication and in
   the process it also adds some flags that were missed before.

 - Removed some dead code and scripts/draw_functrace.py

   draw_functrace.py hasn't worked in years and as nobody complained
   about it, remove it.

 - Constify struct event_trigger_ops

   The event_trigger_ops is just a structure that has function pointers
   that are assigned when the variables are created. These variables
   should all be constants.

 - Other minor clean ups and fixes

* tag 'trace-v6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  tracing: Replace strncpy with memcpy for fixed-length substring copy
  tracing: Fix synth event printk format for str fields
  tracing: Do not use PERF enums when perf is not defined
  tracing: Ensure module defining synth event cannot be unloaded while tracing
  tracing: fix return value in __ftrace_event_enable_disable for TRACE_REG_UNREGISTER
  tracing/osnoise: Fix possible recursive locking for cpus_read_lock()
  tracing: Align synth event print fmt
  tracing: gfp: vsprintf: Do not print "none" when using %pGg printf format
  tracepoint: Print the function symbol when tracepoint_debug is set
  tracing: Constify struct event_trigger_ops
  scripts/tracing: Remove scripts/tracing/draw_functrace.py
  tracing: Update MAINTAINERS file to include tracepoint.c
  tracing/user_events: Slightly simplify user_seq_show()
  tracing/user_events: Don't use %pK through printk
  tracing: gfp: Remove duplication of recording GFP flags
  tracing: Remove orphaned event_trace_printk
  ring-buffer: Fix typo in comment about header page pointer
  tracing: Add traceoff_after_boot option

11 files changed, 88 insertions, 47 deletions

diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index bb6089c2951e5..9d4d951090d37 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -5318,7 +5318,7 @@ rb_get_reader_page(struct ring_buffer_per_cpu *cpu_buffer)
 	 * moving it. The page before the header page has the
 	 * flag bit '1' set if it is pointing to the page we want.
 	 * but if the writer is in the process of moving it
-	 * than it will be '2' or already moved '0'.
+	 * then it will be '2' or already moved '0'.
 	 */
 
 	ret = rb_head_page_replace(reader, cpu_buffer->reader_page);
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 4f424364d1c6c..826267f5b6506 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -87,6 +87,7 @@ void __init disable_tracing_selftest(const char *reason)
 static struct trace_iterator *tracepoint_print_iter;
 int tracepoint_printk;
 static bool tracepoint_printk_stop_on_boot __initdata;
+static bool traceoff_after_boot __initdata;
 static DEFINE_STATIC_KEY_FALSE(tracepoint_printk_key);
 
 /* For tracers that don't implement custom flags */
@@ -330,6 +331,13 @@ static int __init set_tracepoint_printk_stop(char *str)
 }
 __setup("tp_printk_stop_on_boot", set_tracepoint_printk_stop);
 
+static int __init set_traceoff_after_boot(char *str)
+{
+	traceoff_after_boot = true;
+	return 1;
+}
+__setup("traceoff_after_boot", set_traceoff_after_boot);
+
 unsigned long long ns2usecs(u64 nsec)
 {
 	nsec += 500;
@@ -10709,6 +10717,9 @@ __init static int late_trace_init(void)
 		tracepoint_printk = 0;
 	}
 
+	if (traceoff_after_boot)
+		tracing_off();
+
 	tracing_set_default_clock();
 	clear_boot_tracer();
 	return 0;
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 32da87f45010b..4a6621e2a0fa7 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -1717,7 +1717,7 @@ struct event_trigger_data {
 	unsigned long			count;
 	int				ref;
 	int				flags;
-	struct event_trigger_ops	*ops;
+	const struct event_trigger_ops	*ops;
 	struct event_command		*cmd_ops;
 	struct event_filter __rcu	*filter;
 	char				*filter_str;
@@ -1962,7 +1962,7 @@ struct event_command {
 	int			(*set_filter)(char *filter_str,
 					      struct event_trigger_data *data,
 					      struct trace_event_file *file);
-	struct event_trigger_ops *(*get_trigger_ops)(char *cmd, char *param);
+	const struct event_trigger_ops *(*get_trigger_ops)(char *cmd, char *param);
 };
 
 /**
diff --git a/kernel/trace/trace_eprobe.c b/kernel/trace/trace_eprobe.c
index 82fd637cfc19e..c1cc2fe548879 100644
--- a/kernel/trace/trace_eprobe.c
+++ b/kernel/trace/trace_eprobe.c
@@ -478,7 +478,7 @@ static void eprobe_trigger_func(struct event_trigger_data *data,
 	__eprobe_trace_func(edata, rec);
 }
 
-static struct event_trigger_ops eprobe_trigger_ops = {
+static const struct event_trigger_ops eprobe_trigger_ops = {
 	.trigger		= eprobe_trigger_func,
 	.print			= eprobe_trigger_print,
 	.init			= eprobe_trigger_init,
@@ -507,8 +507,8 @@ static void eprobe_trigger_unreg_func(char *glob,
 
 }
 
-static struct event_trigger_ops *eprobe_trigger_get_ops(char *cmd,
-							char *param)
+static const struct event_trigger_ops *eprobe_trigger_get_ops(char *cmd,
+							      char *param)
 {
 	return &eprobe_trigger_ops;
 }
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 513de9ceb80ef..8e7603acca210 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -790,7 +790,9 @@ static int __ftrace_event_enable_disable(struct trace_event_file *file,
 				clear_bit(EVENT_FILE_FL_RECORDED_TGID_BIT, &file->flags);
 			}
 
-			call->class->reg(call, TRACE_REG_UNREGISTER, file);
+			ret = call->class->reg(call, TRACE_REG_UNREGISTER, file);
+
+			WARN_ON_ONCE(ret);
 		}
 		/* If in SOFT_MODE, just set the SOFT_DISABLE_BIT, else clear it */
 		if (file->flags & EVENT_FILE_FL_SOFT_MODE)
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 53dc6719181e5..1260c23cfa5fc 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -6203,7 +6203,7 @@ static void event_hist_trigger_free(struct event_trigger_data *data)
 	}
 }
 
-static struct event_trigger_ops event_hist_trigger_ops = {
+static const struct event_trigger_ops event_hist_trigger_ops = {
 	.trigger		= event_hist_trigger,
 	.print			= event_hist_trigger_print,
 	.init			= event_hist_trigger_init,
@@ -6235,15 +6235,15 @@ static void event_hist_trigger_named_free(struct event_trigger_data *data)
 	}
 }
 
-static struct event_trigger_ops event_hist_trigger_named_ops = {
+static const struct event_trigger_ops event_hist_trigger_named_ops = {
 	.trigger		= event_hist_trigger,
 	.print			= event_hist_trigger_print,
 	.init			= event_hist_trigger_named_init,
 	.free			= event_hist_trigger_named_free,
 };
 
-static struct event_trigger_ops *event_hist_get_trigger_ops(char *cmd,
-							    char *param)
+static const struct event_trigger_ops *event_hist_get_trigger_ops(char *cmd,
+								  char *param)
 {
 	return &event_hist_trigger_ops;
 }
@@ -6838,38 +6838,38 @@ hist_enable_count_trigger(struct event_trigger_data *data,
 	hist_enable_trigger(data, buffer, rec, event);
 }
 
-static struct event_trigger_ops hist_enable_trigger_ops = {
+static const struct event_trigger_ops hist_enable_trigger_ops = {
 	.trigger		= hist_enable_trigger,
 	.print			= event_enable_trigger_print,
 	.init			= event_trigger_init,
 	.free			= event_enable_trigger_free,
 };
 
-static struct event_trigger_ops hist_enable_count_trigger_ops = {
+static const struct event_trigger_ops hist_enable_count_trigger_ops = {
 	.trigger		= hist_enable_count_trigger,
 	.print			= event_enable_trigger_print,
 	.init			= event_trigger_init,
 	.free			= event_enable_trigger_free,
 };
 
-static struct event_trigger_ops hist_disable_trigger_ops = {
+static const struct event_trigger_ops hist_disable_trigger_ops = {
 	.trigger		= hist_enable_trigger,
 	.print			= event_enable_trigger_print,
 	.init			= event_trigger_init,
 	.free			= event_enable_trigger_free,
 };
 
-static struct event_trigger_ops hist_disable_count_trigger_ops = {
+static const struct event_trigger_ops hist_disable_count_trigger_ops = {
 	.trigger		= hist_enable_count_trigger,
 	.print			= event_enable_trigger_print,
 	.init			= event_trigger_init,
 	.free			= event_enable_trigger_free,
 };
 
-static struct event_trigger_ops *
+static const struct event_trigger_ops *
 hist_enable_get_trigger_ops(char *cmd, char *param)
 {
-	struct event_trigger_ops *ops;
+	const struct event_trigger_ops *ops;
 	bool enable;
 
 	enable = (strcmp(cmd, ENABLE_HIST_STR) == 0);
diff --git a/kernel/trace/trace_events_synth.c b/kernel/trace/trace_events_synth.c
index e3f7d09e55120..969f48742d72c 100644
--- a/kernel/trace/trace_events_synth.c
+++ b/kernel/trace/trace_events_synth.c
@@ -207,7 +207,7 @@ static int synth_field_string_size(char *type)
 	if (len == 0)
 		return 0; /* variable-length string */
 
-	strncpy(buf, start, len);
+	memcpy(buf, start, len);
 	buf[len] = '\0';
 
 	err = kstrtouint(buf, 0, &size);
@@ -305,7 +305,7 @@ static const char *synth_field_fmt(char *type)
 	else if (strcmp(type, "gfp_t") == 0)
 		fmt = "%x";
 	else if (synth_field_is_string(type))
-		fmt = "%.*s";
+		fmt = "%s";
 	else if (synth_field_is_stack(type))
 		fmt = "%s";
 
@@ -612,7 +612,7 @@ static int __set_synth_event_print_fmt(struct synth_event *event,
 		fmt = synth_field_fmt(event->fields[i]->type);
 		pos += snprintf(buf + pos, LEN_OR_ZERO, "%s=%s%s",
 				event->fields[i]->name, fmt,
-				i == event->n_fields - 1 ? "" : ", ");
+				i == event->n_fields - 1 ? "" : " ");
 	}
 	pos += snprintf(buf + pos, LEN_OR_ZERO, "\"");
 
@@ -852,6 +852,38 @@ static struct trace_event_fields synth_event_fields_array[] = {
 	{}
 };
 
+static int synth_event_reg(struct trace_event_call *call,
+		    enum trace_reg type, void *data)
+{
+	struct synth_event *event = container_of(call, struct synth_event, call);
+
+	switch (type) {
+#ifdef CONFIG_PERF_EVENTS
+	case TRACE_REG_PERF_REGISTER:
+#endif
+	case TRACE_REG_REGISTER:
+		if (!try_module_get(event->mod))
+			return -EBUSY;
+		break;
+	default:
+		break;
+	}
+
+	int ret = trace_event_reg(call, type, data);
+
+	switch (type) {
+#ifdef CONFIG_PERF_EVENTS
+	case TRACE_REG_PERF_UNREGISTER:
+#endif
+	case TRACE_REG_UNREGISTER:
+		module_put(event->mod);
+		break;
+	default:
+		break;
+	}
+	return ret;
+}
+
 static int register_synth_event(struct synth_event *event)
 {
 	struct trace_event_call *call = &event->call;
@@ -881,7 +913,7 @@ static int register_synth_event(struct synth_event *event)
 		goto out;
 	}
 	call->flags = TRACE_EVENT_FL_TRACEPOINT;
-	call->class->reg = trace_event_reg;
+	call->class->reg = synth_event_reg;
 	call->class->probe = trace_event_raw_event_synth;
 	call->data = event;
 	call->tp = event->tp;
diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c
index d454489470946..b66b6d235d913 100644
--- a/kernel/trace/trace_events_trigger.c
+++ b/kernel/trace/trace_events_trigger.c
@@ -825,7 +825,7 @@ struct event_trigger_data *event_trigger_alloc(struct event_command *cmd_ops,
 					       void *private_data)
 {
 	struct event_trigger_data *trigger_data;
-	struct event_trigger_ops *trigger_ops;
+	const struct event_trigger_ops *trigger_ops;
 
 	trigger_ops = cmd_ops->get_trigger_ops(cmd, param);
 
@@ -1367,38 +1367,38 @@ traceoff_trigger_print(struct seq_file *m, struct event_trigger_data *data)
 				   data->filter_str);
 }
 
-static struct event_trigger_ops traceon_trigger_ops = {
+static const struct event_trigger_ops traceon_trigger_ops = {
 	.trigger		= traceon_trigger,
 	.print			= traceon_trigger_print,
 	.init			= event_trigger_init,
 	.free			= event_trigger_free,
 };
 
-static struct event_trigger_ops traceon_count_trigger_ops = {
+static const struct event_trigger_ops traceon_count_trigger_ops = {
 	.trigger		= traceon_count_trigger,
 	.print			= traceon_trigger_print,
 	.init			= event_trigger_init,
 	.free			= event_trigger_free,
 };
 
-static struct event_trigger_ops traceoff_trigger_ops = {
+static const struct event_trigger_ops traceoff_trigger_ops = {
 	.trigger		= traceoff_trigger,
 	.print			= traceoff_trigger_print,
 	.init			= event_trigger_init,
 	.free			= event_trigger_free,
 };
 
-static struct event_trigger_ops traceoff_count_trigger_ops = {
+static const struct event_trigger_ops traceoff_count_trigger_ops = {
 	.trigger		= traceoff_count_trigger,
 	.print			= traceoff_trigger_print,
 	.init			= event_trigger_init,
 	.free			= event_trigger_free,
 };
 
-static struct event_trigger_ops *
+static const struct event_trigger_ops *
 onoff_get_trigger_ops(char *cmd, char *param)
 {
-	struct event_trigger_ops *ops;
+	const struct event_trigger_ops *ops;
 
 	/* we register both traceon and traceoff to this callback */
 	if (strcmp(cmd, "traceon") == 0)
@@ -1491,21 +1491,21 @@ snapshot_trigger_print(struct seq_file *m, struct event_trigger_data *data)
 				   data->filter_str);
 }
 
-static struct event_trigger_ops snapshot_trigger_ops = {
+static const struct event_trigger_ops snapshot_trigger_ops = {
 	.trigger		= snapshot_trigger,
 	.print			= snapshot_trigger_print,
 	.init			= event_trigger_init,
 	.free			= event_trigger_free,
 };
 
-static struct event_trigger_ops snapshot_count_trigger_ops = {
+static const struct event_trigger_ops snapshot_count_trigger_ops = {
 	.trigger		= snapshot_count_trigger,
 	.print			= snapshot_trigger_print,
 	.init			= event_trigger_init,
 	.free			= event_trigger_free,
 };
 
-static struct event_trigger_ops *
+static const struct event_trigger_ops *
 snapshot_get_trigger_ops(char *cmd, char *param)
 {
 	return param ? &snapshot_count_trigger_ops : &snapshot_trigger_ops;
@@ -1586,21 +1586,21 @@ stacktrace_trigger_print(struct seq_file *m, struct event_trigger_data *data)
 				   data->filter_str);
 }
 
-static struct event_trigger_ops stacktrace_trigger_ops = {
+static const struct event_trigger_ops stacktrace_trigger_ops = {
 	.trigger		= stacktrace_trigger,
 	.print			= stacktrace_trigger_print,
 	.init			= event_trigger_init,
 	.free			= event_trigger_free,
 };
 
-static struct event_trigger_ops stacktrace_count_trigger_ops = {
+static const struct event_trigger_ops stacktrace_count_trigger_ops = {
 	.trigger		= stacktrace_count_trigger,
 	.print			= stacktrace_trigger_print,
 	.init			= event_trigger_init,
 	.free			= event_trigger_free,
 };
 
-static struct event_trigger_ops *
+static const struct event_trigger_ops *
 stacktrace_get_trigger_ops(char *cmd, char *param)
 {
 	return param ? &stacktrace_count_trigger_ops : &stacktrace_trigger_ops;
@@ -1711,28 +1711,28 @@ void event_enable_trigger_free(struct event_trigger_data *data)
 	}
 }
 
-static struct event_trigger_ops event_enable_trigger_ops = {
+static const struct event_trigger_ops event_enable_trigger_ops = {
 	.trigger		= event_enable_trigger,
 	.print			= event_enable_trigger_print,
 	.init			= event_trigger_init,
 	.free			= event_enable_trigger_free,
 };
 
-static struct event_trigger_ops event_enable_count_trigger_ops = {
+static const struct event_trigger_ops event_enable_count_trigger_ops = {
 	.trigger		= event_enable_count_trigger,
 	.print			= event_enable_trigger_print,
 	.init			= event_trigger_init,
 	.free			= event_enable_trigger_free,
 };
 
-static struct event_trigger_ops event_disable_trigger_ops = {
+static const struct event_trigger_ops event_disable_trigger_ops = {
 	.trigger		= event_enable_trigger,
 	.print			= event_enable_trigger_print,
 	.init			= event_trigger_init,
 	.free			= event_enable_trigger_free,
 };
 
-static struct event_trigger_ops event_disable_count_trigger_ops = {
+static const struct event_trigger_ops event_disable_count_trigger_ops = {
 	.trigger		= event_enable_count_trigger,
 	.print			= event_enable_trigger_print,
 	.init			= event_trigger_init,
@@ -1916,10 +1916,10 @@ void event_enable_unregister_trigger(char *glob,
 		data->ops->free(data);
 }
 
-static struct event_trigger_ops *
+static const struct event_trigger_ops *
 event_enable_get_trigger_ops(char *cmd, char *param)
 {
-	struct event_trigger_ops *ops;
+	const struct event_trigger_ops *ops;
 	bool enable;
 
 #ifdef CONFIG_HIST_TRIGGERS
diff --git a/kernel/trace/trace_events_user.c b/kernel/trace/trace_events_user.c
index 97325fbd62836..af42aaa3d172c 100644
--- a/kernel/trace/trace_events_user.c
+++ b/kernel/trace/trace_events_user.c
@@ -455,7 +455,7 @@ static void user_event_enabler_fault_fixup(struct work_struct *work)
 	if (ret && ret != -ENOENT) {
 		struct user_event *user = enabler->event;
 
-		pr_warn("user_events: Fault for mm: 0x%pK @ 0x%llx event: %s\n",
+		pr_warn("user_events: Fault for mm: 0x%p @ 0x%llx event: %s\n",
 			mm->mm, (unsigned long long)uaddr, EVENT_NAME(user));
 	}
 
@@ -2793,11 +2793,8 @@ static int user_seq_show(struct seq_file *m, void *p)
 
 		seq_printf(m, "%s", EVENT_TP_NAME(user));
 
-		if (status != 0)
-			seq_puts(m, " #");
-
 		if (status != 0) {
-			seq_puts(m, " Used by");
+			seq_puts(m, " # Used by");
 			if (status & EVENT_STATUS_FTRACE)
 				seq_puts(m, " ftrace");
 			if (status & EVENT_STATUS_PERF)
diff --git a/kernel/trace/trace_osnoise.c b/kernel/trace/trace_osnoise.c
index 647516a73fa28..e732c9e37e142 100644
--- a/kernel/trace/trace_osnoise.c
+++ b/kernel/trace/trace_osnoise.c
@@ -2006,7 +2006,6 @@ static int start_kthread(unsigned int cpu)
 
 	if (IS_ERR(kthread)) {
 		pr_err(BANNER "could not start sampling thread\n");
-		stop_per_cpu_kthreads();
 		return -ENOMEM;
 	}
 
diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c
index 1848ce7e2976f..62719d2941c90 100644
--- a/kernel/tracepoint.c
+++ b/kernel/tracepoint.c
@@ -127,7 +127,7 @@ static void debug_print_probes(struct tracepoint_func *funcs)
 		return;
 
 	for (i = 0; funcs[i].func; i++)
-		printk(KERN_DEBUG "Probe %d : %p\n", i, funcs[i].func);
+		printk(KERN_DEBUG "Probe %d : %pSb\n", i, funcs[i].func);
 }
 
 static struct tracepoint_func *