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

1 files changed, 36 insertions, 4 deletions

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;