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6
7#define pr_fmt(fmt) "trace_boot: " fmt
8
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>
19
20#include "trace.h"
21
22#define MAX_BUF_LEN 256
23
24static void __init
25trace_boot_set_instance_options(struct trace_array *tr, struct xbc_node *node)
26{
27 struct xbc_node *anode;
28 const char *p;
29 char buf[MAX_BUF_LEN];
30 unsigned long v = 0;
31
32
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);
36 continue;
37 }
38
39 if (trace_set_options(tr, buf) < 0)
40 pr_err("Failed to set option: %s\n", buf);
41 }
42
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);
47 }
48
49 p = xbc_node_find_value(node, "buffer_size", NULL);
50 if (p && *p != '\0') {
51 v = memparse(p, NULL);
52 if (v < PAGE_SIZE)
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);
56 }
57
58 p = xbc_node_find_value(node, "cpumask", NULL);
59 if (p && *p != '\0') {
60 cpumask_var_t new_mask;
61
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);
67 }
68 }
69}
70
71#ifdef CONFIG_EVENT_TRACING
72static void __init
73trace_boot_enable_events(struct trace_array *tr, struct xbc_node *node)
74{
75 struct xbc_node *anode;
76 char buf[MAX_BUF_LEN];
77 const char *p;
78
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);
82 continue;
83 }
84
85 if (ftrace_set_clr_event(tr, buf, 1) < 0)
86 pr_err("Failed to enable event: %s\n", p);
87 }
88}
89
90#ifdef CONFIG_KPROBE_EVENTS
91static int __init
92trace_boot_add_kprobe_event(struct xbc_node *node, const char *event)
93{
94 struct dynevent_cmd cmd;
95 struct xbc_node *anode;
96 char buf[MAX_BUF_LEN];
97 const char *val;
98 int ret = 0;
99
100 xbc_node_for_each_array_value(node, "probes", anode, val) {
101 kprobe_event_cmd_init(&cmd, buf, MAX_BUF_LEN);
102
103 ret = kprobe_event_gen_cmd_start(&cmd, event, val);
104 if (ret) {
105 pr_err("Failed to generate probe: %s\n", buf);
106 break;
107 }
108
109 ret = kprobe_event_gen_cmd_end(&cmd);
110 if (ret) {
111 pr_err("Failed to add probe: %s\n", buf);
112 break;
113 }
114 }
115
116 return ret;
117}
118#else
119static inline int __init
120trace_boot_add_kprobe_event(struct xbc_node *node, const char *event)
121{
122 pr_err("Kprobe event is not supported.\n");
123 return -ENOTSUPP;
124}
125#endif
126
127#ifdef CONFIG_SYNTH_EVENTS
128static int __init
129trace_boot_add_synth_event(struct xbc_node *node, const char *event)
130{
131 struct dynevent_cmd cmd;
132 struct xbc_node *anode;
133 char buf[MAX_BUF_LEN];
134 const char *p;
135 int ret;
136
137 synth_event_cmd_init(&cmd, buf, MAX_BUF_LEN);
138
139 ret = synth_event_gen_cmd_start(&cmd, event, NULL);
140 if (ret)
141 return ret;
142
143 xbc_node_for_each_array_value(node, "fields", anode, p) {
144 ret = synth_event_add_field_str(&cmd, p);
145 if (ret)
146 return ret;
147 }
148
149 ret = synth_event_gen_cmd_end(&cmd);
150 if (ret < 0)
151 pr_err("Failed to add synthetic event: %s\n", buf);
152
153 return ret;
154}
155#else
156static inline int __init
157trace_boot_add_synth_event(struct xbc_node *node, const char *event)
158{
159 pr_err("Synthetic event is not supported.\n");
160 return -ENOTSUPP;
161}
162#endif
163
164static void __init
165trace_boot_init_one_event(struct trace_array *tr, struct xbc_node *gnode,
166 struct xbc_node *enode)
167{
168 struct trace_event_file *file;
169 struct xbc_node *anode;
170 char buf[MAX_BUF_LEN];
171 const char *p, *group, *event;
172
173 group = xbc_node_get_data(gnode);
174 event = xbc_node_get_data(enode);
175
176 if (!strcmp(group, "kprobes"))
177 if (trace_boot_add_kprobe_event(enode, event) < 0)
178 return;
179 if (!strcmp(group, "synthetic"))
180 if (trace_boot_add_synth_event(enode, event) < 0)
181 return;
182
183 mutex_lock(&event_mutex);
184 file = find_event_file(tr, group, event);
185 if (!file) {
186 pr_err("Failed to find event: %s:%s\n", group, event);
187 goto out;
188 }
189
190 p = xbc_node_find_value(enode, "filter", NULL);
191 if (p && *p != '\0') {
192 if (strlcpy(buf, p, ARRAY_SIZE(buf)) >= ARRAY_SIZE(buf))
193 pr_err("filter string is too long: %s\n", p);
194 else if (apply_event_filter(file, buf) < 0)
195 pr_err("Failed to apply filter: %s\n", buf);
196 }
197
198 xbc_node_for_each_array_value(enode, "actions", anode, p) {
199 if (strlcpy(buf, p, ARRAY_SIZE(buf)) >= ARRAY_SIZE(buf))
200 pr_err("action string is too long: %s\n", p);
201 else if (trigger_process_regex(file, buf) < 0)
202 pr_err("Failed to apply an action: %s\n", buf);
203 }
204
205 if (xbc_node_find_value(enode, "enable", NULL)) {
206 if (trace_event_enable_disable(file, 1, 0) < 0)
207 pr_err("Failed to enable event node: %s:%s\n",
208 group, event);
209 }
210out:
211 mutex_unlock(&event_mutex);
212}
213
214static void __init
215trace_boot_init_events(struct trace_array *tr, struct xbc_node *node)
216{
217 struct xbc_node *gnode, *enode;
218
219 node = xbc_node_find_child(node, "event");
220 if (!node)
221 return;
222
223 xbc_node_for_each_child(node, gnode)
224 xbc_node_for_each_child(gnode, enode)
225 trace_boot_init_one_event(tr, gnode, enode);
226}
227#else
228#define trace_boot_enable_events(tr, node) do {} while (0)
229#define trace_boot_init_events(tr, node) do {} while (0)
230#endif
231
232#ifdef CONFIG_DYNAMIC_FTRACE
233static void __init
234trace_boot_set_ftrace_filter(struct trace_array *tr, struct xbc_node *node)
235{
236 struct xbc_node *anode;
237 const char *p;
238 char *q;
239
240 xbc_node_for_each_array_value(node, "ftrace.filters", anode, p) {
241 q = kstrdup(p, GFP_KERNEL);
242 if (!q)
243 return;
244 if (ftrace_set_filter(tr->ops, q, strlen(q), 0) < 0)
245 pr_err("Failed to add %s to ftrace filter\n", p);
246 else
247 ftrace_filter_param = true;
248 kfree(q);
249 }
250 xbc_node_for_each_array_value(node, "ftrace.notraces", anode, p) {
251 q = kstrdup(p, GFP_KERNEL);
252 if (!q)
253 return;
254 if (ftrace_set_notrace(tr->ops, q, strlen(q), 0) < 0)
255 pr_err("Failed to add %s to ftrace filter\n", p);
256 else
257 ftrace_filter_param = true;
258 kfree(q);
259 }
260}
261#else
262#define trace_boot_set_ftrace_filter(tr, node) do {} while (0)
263#endif
264
265static void __init
266trace_boot_enable_tracer(struct trace_array *tr, struct xbc_node *node)
267{
268 const char *p;
269
270 trace_boot_set_ftrace_filter(tr, node);
271
272 p = xbc_node_find_value(node, "tracer", NULL);
273 if (p && *p != '\0') {
274 if (tracing_set_tracer(tr, p) < 0)
275 pr_err("Failed to set given tracer: %s\n", p);
276 }
277}
278
279static void __init
280trace_boot_init_one_instance(struct trace_array *tr, struct xbc_node *node)
281{
282 trace_boot_set_instance_options(tr, node);
283 trace_boot_init_events(tr, node);
284 trace_boot_enable_events(tr, node);
285 trace_boot_enable_tracer(tr, node);
286}
287
288static void __init
289trace_boot_init_instances(struct xbc_node *node)
290{
291 struct xbc_node *inode;
292 struct trace_array *tr;
293 const char *p;
294
295 node = xbc_node_find_child(node, "instance");
296 if (!node)
297 return;
298
299 xbc_node_for_each_child(node, inode) {
300 p = xbc_node_get_data(inode);
301 if (!p || *p == '\0')
302 continue;
303
304 tr = trace_array_get_by_name(p);
305 if (!tr) {
306 pr_err("Failed to get trace instance %s\n", p);
307 continue;
308 }
309 trace_boot_init_one_instance(tr, inode);
310 trace_array_put(tr);
311 }
312}
313
314static int __init trace_boot_init(void)
315{
316 struct xbc_node *trace_node;
317 struct trace_array *tr;
318
319 trace_node = xbc_find_node("ftrace");
320 if (!trace_node)
321 return 0;
322
323 tr = top_trace_array();
324 if (!tr)
325 return 0;
326
327
328 trace_boot_init_one_instance(tr, trace_node);
329 trace_boot_init_instances(trace_node);
330
331 return 0;
332}
333
334fs_initcall(trace_boot_init);
335
