1 // SPDX-License-Identifier: GPL-2.0
4 * Tracing kernel boot-time
7 #define pr_fmt(fmt) "trace_boot: " fmt
9 #include <linux/bootconfig.h>
10 #include <linux/cpumask.h>
11 #include <linux/ftrace.h>
12 #include <linux/init.h>
13 #include <linux/kernel.h>
14 #include <linux/mutex.h>
15 #include <linux/string.h>
16 #include <linux/slab.h>
17 #include <linux/trace.h>
18 #include <linux/trace_events.h>
22 #define MAX_BUF_LEN 256
25 trace_boot_set_instance_options(struct trace_array *tr, struct xbc_node *node)
27 struct xbc_node *anode;
29 char buf[MAX_BUF_LEN];
32 /* Common ftrace options */
33 xbc_node_for_each_array_value(node, "options", anode, p) {
34 if (strlcpy(buf, p, ARRAY_SIZE(buf)) >= ARRAY_SIZE(buf)) {
35 pr_err("String is too long: %s\n", p);
39 if (trace_set_options(tr, buf) < 0)
40 pr_err("Failed to set option: %s\n", buf);
43 p = xbc_node_find_value(node, "trace_clock", NULL);
44 if (p && *p != '\0') {
45 if (tracing_set_clock(tr, p) < 0)
46 pr_err("Failed to set trace clock: %s\n", p);
49 p = xbc_node_find_value(node, "buffer_size", NULL);
50 if (p && *p != '\0') {
51 v = memparse(p, NULL);
53 pr_err("Buffer size is too small: %s\n", p);
54 if (tracing_resize_ring_buffer(tr, v, RING_BUFFER_ALL_CPUS) < 0)
55 pr_err("Failed to resize trace buffer to %s\n", p);
58 p = xbc_node_find_value(node, "cpumask", NULL);
59 if (p && *p != '\0') {
60 cpumask_var_t new_mask;
62 if (alloc_cpumask_var(&new_mask, GFP_KERNEL)) {
63 if (cpumask_parse(p, new_mask) < 0 ||
64 tracing_set_cpumask(tr, new_mask) < 0)
65 pr_err("Failed to set new CPU mask %s\n", p);
66 free_cpumask_var(new_mask);
71 #ifdef CONFIG_EVENT_TRACING
73 trace_boot_enable_events(struct trace_array *tr, struct xbc_node *node)
75 struct xbc_node *anode;
76 char buf[MAX_BUF_LEN];
79 xbc_node_for_each_array_value(node, "events", anode, p) {
80 if (strlcpy(buf, p, ARRAY_SIZE(buf)) >= ARRAY_SIZE(buf)) {
81 pr_err("String is too long: %s\n", p);
85 if (ftrace_set_clr_event(tr, buf, 1) < 0)
86 pr_err("Failed to enable event: %s\n", p);
90 #ifdef CONFIG_KPROBE_EVENTS
92 trace_boot_add_kprobe_event(struct xbc_node *node, const char *event)
94 struct dynevent_cmd cmd;
95 struct xbc_node *anode;
96 char buf[MAX_BUF_LEN];
100 xbc_node_for_each_array_value(node, "probes", anode, val) {
101 kprobe_event_cmd_init(&cmd, buf, MAX_BUF_LEN);
103 ret = kprobe_event_gen_cmd_start(&cmd, event, val);
107 ret = kprobe_event_gen_cmd_end(&cmd);
109 pr_err("Failed to add probe: %s\n", buf);
115 static inline int __init
116 trace_boot_add_kprobe_event(struct xbc_node *node, const char *event)
118 pr_err("Kprobe event is not supported.\n");
123 #ifdef CONFIG_HIST_TRIGGERS
125 trace_boot_add_synth_event(struct xbc_node *node, const char *event)
127 struct dynevent_cmd cmd;
128 struct xbc_node *anode;
129 char buf[MAX_BUF_LEN];
133 synth_event_cmd_init(&cmd, buf, MAX_BUF_LEN);
135 ret = synth_event_gen_cmd_start(&cmd, event, NULL);
139 xbc_node_for_each_array_value(node, "fields", anode, p) {
140 ret = synth_event_add_field_str(&cmd, p);
145 ret = synth_event_gen_cmd_end(&cmd);
147 pr_err("Failed to add synthetic event: %s\n", buf);
152 static inline int __init
153 trace_boot_add_synth_event(struct xbc_node *node, const char *event)
155 pr_err("Synthetic event is not supported.\n");
161 trace_boot_init_one_event(struct trace_array *tr, struct xbc_node *gnode,
162 struct xbc_node *enode)
164 struct trace_event_file *file;
165 struct xbc_node *anode;
166 char buf[MAX_BUF_LEN];
167 const char *p, *group, *event;
169 group = xbc_node_get_data(gnode);
170 event = xbc_node_get_data(enode);
172 if (!strcmp(group, "kprobes"))
173 if (trace_boot_add_kprobe_event(enode, event) < 0)
175 if (!strcmp(group, "synthetic"))
176 if (trace_boot_add_synth_event(enode, event) < 0)
179 mutex_lock(&event_mutex);
180 file = find_event_file(tr, group, event);
182 pr_err("Failed to find event: %s:%s\n", group, event);
186 p = xbc_node_find_value(enode, "filter", NULL);
187 if (p && *p != '\0') {
188 if (strlcpy(buf, p, ARRAY_SIZE(buf)) >= ARRAY_SIZE(buf))
189 pr_err("filter string is too long: %s\n", p);
190 else if (apply_event_filter(file, buf) < 0)
191 pr_err("Failed to apply filter: %s\n", buf);
194 xbc_node_for_each_array_value(enode, "actions", anode, p) {
195 if (strlcpy(buf, p, ARRAY_SIZE(buf)) >= ARRAY_SIZE(buf))
196 pr_err("action string is too long: %s\n", p);
197 else if (trigger_process_regex(file, buf) < 0)
198 pr_err("Failed to apply an action: %s\n", buf);
201 if (xbc_node_find_value(enode, "enable", NULL)) {
202 if (trace_event_enable_disable(file, 1, 0) < 0)
203 pr_err("Failed to enable event node: %s:%s\n",
207 mutex_unlock(&event_mutex);
211 trace_boot_init_events(struct trace_array *tr, struct xbc_node *node)
213 struct xbc_node *gnode, *enode;
215 node = xbc_node_find_child(node, "event");
218 /* per-event key starts with "event.GROUP.EVENT" */
219 xbc_node_for_each_child(node, gnode)
220 xbc_node_for_each_child(gnode, enode)
221 trace_boot_init_one_event(tr, gnode, enode);
224 #define trace_boot_enable_events(tr, node) do {} while (0)
225 #define trace_boot_init_events(tr, node) do {} while (0)
228 #ifdef CONFIG_DYNAMIC_FTRACE
230 trace_boot_set_ftrace_filter(struct trace_array *tr, struct xbc_node *node)
232 struct xbc_node *anode;
236 xbc_node_for_each_array_value(node, "ftrace.filters", anode, p) {
237 q = kstrdup(p, GFP_KERNEL);
240 if (ftrace_set_filter(tr->ops, q, strlen(q), 0) < 0)
241 pr_err("Failed to add %s to ftrace filter\n", p);
243 ftrace_filter_param = true;
246 xbc_node_for_each_array_value(node, "ftrace.notraces", anode, p) {
247 q = kstrdup(p, GFP_KERNEL);
250 if (ftrace_set_notrace(tr->ops, q, strlen(q), 0) < 0)
251 pr_err("Failed to add %s to ftrace filter\n", p);
253 ftrace_filter_param = true;
258 #define trace_boot_set_ftrace_filter(tr, node) do {} while (0)
262 trace_boot_enable_tracer(struct trace_array *tr, struct xbc_node *node)
266 trace_boot_set_ftrace_filter(tr, node);
268 p = xbc_node_find_value(node, "tracer", NULL);
269 if (p && *p != '\0') {
270 if (tracing_set_tracer(tr, p) < 0)
271 pr_err("Failed to set given tracer: %s\n", p);
276 trace_boot_init_one_instance(struct trace_array *tr, struct xbc_node *node)
278 trace_boot_set_instance_options(tr, node);
279 trace_boot_init_events(tr, node);
280 trace_boot_enable_events(tr, node);
281 trace_boot_enable_tracer(tr, node);
285 trace_boot_init_instances(struct xbc_node *node)
287 struct xbc_node *inode;
288 struct trace_array *tr;
291 node = xbc_node_find_child(node, "instance");
295 xbc_node_for_each_child(node, inode) {
296 p = xbc_node_get_data(inode);
297 if (!p || *p == '\0')
300 tr = trace_array_get_by_name(p);
302 pr_err("Failed to get trace instance %s\n", p);
305 trace_boot_init_one_instance(tr, inode);
310 static int __init trace_boot_init(void)
312 struct xbc_node *trace_node;
313 struct trace_array *tr;
315 trace_node = xbc_find_node("ftrace");
319 tr = top_trace_array();
323 /* Global trace array is also one instance */
324 trace_boot_init_one_instance(tr, trace_node);
325 trace_boot_init_instances(trace_node);
330 fs_initcall(trace_boot_init);