[PATCH v4 01/10] tracing/boot: Fix a hist trigger dependency for boot time tracing

[Masami Hiramatsu <mhiramat@kernel.org>]

Fixes a build error when CONFIG_HIST_TRIGGERS=n with boot-time
tracing. Since the trigger_process_regex() is defined only
when CONFIG_HIST_TRIGGERS=y, if it is disabled, the 'actions'
event option also must be disabled.

Fixes: 81a59555ff15 ("tracing/boot: Add per-event settings")
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
---
 Changes in v3:
  - Use IS_ENABLED() instead of #ifdef and show an error if
    CONFIG_HIST_TRIGGERS is not set but per-event actions
    specified.
---
 kernel/trace/trace_boot.c |   15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/kernel/trace/trace_boot.c b/kernel/trace/trace_boot.c
index 94ef2d099e32..d713714cba67 100644
--- a/kernel/trace/trace_boot.c
+++ b/kernel/trace/trace_boot.c
@@ -205,12 +205,15 @@ trace_boot_init_one_event(struct trace_array *tr, struct xbc_node *gnode,
 			pr_err("Failed to apply filter: %s\n", buf);
 	}
 
-	xbc_node_for_each_array_value(enode, "actions", anode, p) {
-		if (strlcpy(buf, p, ARRAY_SIZE(buf)) >= ARRAY_SIZE(buf))
-			pr_err("action string is too long: %s\n", p);
-		else if (trigger_process_regex(file, buf) < 0)
-			pr_err("Failed to apply an action: %s\n", buf);
-	}
+	if (IS_ENABLED(CONFIG_HIST_TRIGGERS)) {
+		xbc_node_for_each_array_value(enode, "actions", anode, p) {
+			if (strlcpy(buf, p, ARRAY_SIZE(buf)) >= ARRAY_SIZE(buf))
+				pr_err("action string is too long: %s\n", p);
+			else if (trigger_process_regex(file, buf) < 0)
+				pr_err("Failed to apply an action: %s\n", buf);
+		}
+	} else if (xbc_node_find_value(enode, "actions", NULL))
+		pr_err("Failed to apply event actions because CONFIG_HIST_TRIGGERS is not set.\n");
 
 	if (xbc_node_find_value(enode, "enable", NULL)) {
 		if (trace_event_enable_disable(file, 1, 0) < 0)