[RFC PATCH 09/11] tracing: of: Add trace event settings

Masami Hiramatsu
2019-06-21T16:19:37Z

Add per-event settings, which includes filter and actions.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
---
kernel/trace/trace_events_trigger.c | 2 -
kernel/trace/trace_of.c | 81 +++++++++++++++++++++++++++++++++++
2 files changed, 82 insertions(+), 1 deletion(-)

diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c
index 2a2912cb4533..74a19c18219f 100644
--- a/kernel/trace/trace_events_trigger.c
+++ b/kernel/trace/trace_events_trigger.c
@@ -208,7 +208,7 @@ static int event_trigger_regex_open(struct inode *inode, struct file *file)
return ret;
}

-static int trigger_process_regex(struct trace_event_file *file, char *buff)
+int trigger_process_regex(struct trace_event_file *file, char *buff)
{
char *command, *next = buff;
struct event_command *p;
diff --git a/kernel/trace/trace_of.c b/kernel/trace/trace_of.c
index 5e34e2475d42..696f59234e62 100644
--- a/kernel/trace/trace_of.c
+++ b/kernel/trace/trace_of.c
@@ -22,6 +22,7 @@ extern int ftrace_set_clr_event(struct trace_array *tr, char *buf, int set);
extern void __init trace_init_tracepoint_printk(void);
extern ssize_t tracing_resize_ring_buffer(struct trace_array *tr,
unsigned long size, int cpu_id);
+extern int trigger_process_regex(struct trace_event_file *file, char *buff);

static void __init
trace_of_set_ftrace_options(struct trace_array *tr, struct device_node *node)
@@ -98,6 +99,85 @@ trace_of_enable_events(struct trace_array *tr, struct device_node *node)
}
}

+static void __init
+trace_of_init_one_event(struct trace_array *tr, struct device_node *node)
+{
+ struct trace_event_file *file;
+ struct property *prop;
+ char buf[MAX_BUF_LEN];
+ char *bufp;
+ const char *p;
+ int err;
+
+ if (!of_node_name_prefix(node, "event"))
+ return;
+
+ err = of_property_read_string(node, "event", &p);
+ if (err) {
+ pr_err("Failed to find event on %s\n", of_node_full_name(node));
+ return;
+ }
+
+ err = strlcpy(buf, p, ARRAY_SIZE(buf));
+ if (err >= ARRAY_SIZE(buf)) {
+ pr_err("Event name is too long: %s\n", p);
+ return;
+ }
+ bufp = buf;
+
+ p = strsep(&bufp, ":");
+ if (!bufp) {
+ pr_err("%s has no group name\n", buf);
+ return;
+ }
+
+ mutex_lock(&event_mutex);
+ file = find_event_file(tr, buf, bufp);
+ if (!file) {
+ pr_err("Failed to find event: %s\n", buf);
+ return;
+ }
+
+ err = of_property_read_string(node, "filter", &p);
+ if (!err) {
+ if (strlcpy(buf, p, ARRAY_SIZE(buf)) >= ARRAY_SIZE(buf)) {
+ pr_err("filter string is too long: %s\n", p);
+ return;
+ }
+
+ if (apply_event_filter(file, buf) < 0) {
+ pr_err("Failed to apply filter: %s\n", buf);
+ return;
+ }
+ }
+
+ of_property_for_each_string(node, "actions", prop, p) {
+ if (strlcpy(buf, p, ARRAY_SIZE(buf)) >= ARRAY_SIZE(buf)) {
+ pr_err("action string is too long: %s\n", p);
+ continue;
+ }
+
+ if (trigger_process_regex(file, buf) < 0)
+ pr_err("Failed to apply an action: %s\n", buf);
+ }
+
+ if (of_property_read_bool(node, "enable")) {
+ if (trace_event_enable_disable(file, 1, 0) < 0)
+ pr_err("Failed to enable event node: %s\n",
+ of_node_full_name(node));
+ }
+ mutex_unlock(&event_mutex);
+}
+
+static void __init
+trace_of_init_events(struct trace_array *tr, struct device_node *node)
+{
+ struct device_node *enode;
+
+ for_each_child_of_node(node, enode)
+ trace_of_init_one_event(tr, enode);
+}
+
static void __init
trace_of_enable_tracer(struct trace_array *tr, struct device_node *trace_node)
{
@@ -126,6 +206,7 @@ static int __init trace_of_init(void)
goto end;

trace_of_set_ftrace_options(tr, trace_node);
+ trace_of_init_events(tr, trace_node);
trace_of_enable_events(tr, trace_node);
trace_of_enable_tracer(tr, trace_node);