tracing: Four small fixes

- Fixed a ringbuffer bug for nested events having time go backwards
  - Fix a config dependency for boot time tracing to depend on synthetic
    events instead of histograms.
  - Fix trigger format parsing to handle multiple spaces
  - Fix bootconfig to handle failures in multiple events
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Merge tag 'trace-v5.8-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixes from Steven Rostedt:
 "Four small fixes:

   - Fix a ringbuffer bug for nested events having time go backwards

   - Fix a config dependency for boot time tracing to depend on
     synthetic events instead of histograms.

   - Fix trigger format parsing to handle multiple spaces

   - Fix bootconfig to handle failures in multiple events"

* tag 'trace-v5.8-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing/boottime: Fix kprobe multiple events
  tracing: Fix event trigger to accept redundant spaces
  tracing/boot: Fix config dependency for synthedic event
  ring-buffer: Zero out time extend if it is nested and not absolute

kernel/trace/ring_buffer.c

@@ -2427,7 +2427,7 @@ rb_update_event(struct ring_buffer_per_cpu *cpu_buffer,
 	if (unlikely(info->add_timestamp)) {
 		bool abs = ring_buffer_time_stamp_abs(cpu_buffer->buffer);
 
-		event = rb_add_time_stamp(event, info->delta, abs);
+		event = rb_add_time_stamp(event, abs ? info->delta : delta, abs);
 		length -= RB_LEN_TIME_EXTEND;
 		delta = 0;
 	}

kernel/trace/trace_boot.c

@@ -101,12 +101,16 @@ trace_boot_add_kprobe_event(struct xbc_node *node, const char *event)
 		kprobe_event_cmd_init(&cmd, buf, MAX_BUF_LEN);
 
 		ret = kprobe_event_gen_cmd_start(&cmd, event, val);
-		if (ret)
+		if (ret) {
+			pr_err("Failed to generate probe: %s\n", buf);
 			break;
+		}
 
 		ret = kprobe_event_gen_cmd_end(&cmd);
-		if (ret)
+		if (ret) {
 			pr_err("Failed to add probe: %s\n", buf);
+			break;
+		}
 	}
 
 	return ret;
@@ -120,7 +124,7 @@ trace_boot_add_kprobe_event(struct xbc_node *node, const char *event)
 }
 #endif
 
-#ifdef CONFIG_HIST_TRIGGERS
+#ifdef CONFIG_SYNTH_EVENTS
 static int __init
 trace_boot_add_synth_event(struct xbc_node *node, const char *event)
 {

kernel/trace/trace_events_trigger.c

@@ -216,11 +216,17 @@ static int event_trigger_regex_open(struct inode *inode, struct file *file)
 
 int trigger_process_regex(struct trace_event_file *file, char *buff)
 {
-	char *command, *next = buff;
+	char *command, *next;
 	struct event_command *p;
 	int ret = -EINVAL;
 
+	next = buff = skip_spaces(buff);
 	command = strsep(&next, ": \t");
+	if (next) {
+		next = skip_spaces(next);
+		if (!*next)
+			next = NULL;
+	}
 	command = (command[0] != '!') ? command : command + 1;
 
 	mutex_lock(&trigger_cmd_mutex);
@@ -630,8 +636,14 @@ event_trigger_callback(struct event_command *cmd_ops,
 	int ret;
 
 	/* separate the trigger from the filter (t:n [if filter]) */
-	if (param && isdigit(param[0]))
+	if (param && isdigit(param[0])) {
 		trigger = strsep(&param, " \t");
+		if (param) {
+			param = skip_spaces(param);
+			if (!*param)
+				param = NULL;
+		}
+	}
 
 	trigger_ops = cmd_ops->get_trigger_ops(cmd, trigger);
 
@@ -1368,6 +1380,11 @@ int event_enable_trigger_func(struct event_command *cmd_ops,
 	trigger = strsep(&param, " \t");
 	if (!trigger)
 		return -EINVAL;
+	if (param) {
+		param = skip_spaces(param);
+		if (!*param)
+			param = NULL;
+	}
 
 	system = strsep(&trigger, ":");
 	if (!trigger)