Commit | Line | Data |
---|---|---|
0722db01 P |
1 | /* |
2 | * trace_ksym.c - Kernel Symbol Tracer | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or modify | |
5 | * it under the terms of the GNU General Public License as published by | |
6 | * the Free Software Foundation; either version 2 of the License, or | |
7 | * (at your option) any later version. | |
8 | * | |
9 | * This program is distributed in the hope that it will be useful, | |
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
12 | * GNU General Public License for more details. | |
13 | * | |
14 | * You should have received a copy of the GNU General Public License | |
15 | * along with this program; if not, write to the Free Software | |
16 | * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. | |
17 | * | |
18 | * Copyright (C) IBM Corporation, 2009 | |
19 | */ | |
20 | ||
21 | #include <linux/kallsyms.h> | |
22 | #include <linux/uaccess.h> | |
23 | #include <linux/debugfs.h> | |
24 | #include <linux/ftrace.h> | |
25 | #include <linux/module.h> | |
26 | #include <linux/fs.h> | |
27 | ||
28 | #include "trace_output.h" | |
29 | #include "trace_stat.h" | |
30 | #include "trace.h" | |
31 | ||
24f1e32c FW |
32 | #include <linux/hw_breakpoint.h> |
33 | #include <asm/hw_breakpoint.h> | |
34 | ||
35 | /* | |
36 | * For now, let us restrict the no. of symbols traced simultaneously to number | |
0722db01 P |
37 | * of available hardware breakpoint registers. |
38 | */ | |
39 | #define KSYM_TRACER_MAX HBP_NUM | |
40 | ||
41 | #define KSYM_TRACER_OP_LEN 3 /* rw- */ | |
0722db01 | 42 | |
db59504d | 43 | struct trace_ksym { |
24f1e32c | 44 | struct perf_event **ksym_hbp; |
db59504d | 45 | unsigned long ksym_addr; |
24f1e32c FW |
46 | int type; |
47 | int len; | |
db59504d LZ |
48 | #ifdef CONFIG_PROFILE_KSYM_TRACER |
49 | unsigned long counter; | |
50 | #endif | |
51 | struct hlist_node ksym_hlist; | |
52 | }; | |
53 | ||
0722db01 P |
54 | static struct trace_array *ksym_trace_array; |
55 | ||
56 | static unsigned int ksym_filter_entry_count; | |
57 | static unsigned int ksym_tracing_enabled; | |
58 | ||
59 | static HLIST_HEAD(ksym_filter_head); | |
60 | ||
73874005 FW |
61 | static DEFINE_MUTEX(ksym_tracer_mutex); |
62 | ||
0722db01 P |
63 | #ifdef CONFIG_PROFILE_KSYM_TRACER |
64 | ||
65 | #define MAX_UL_INT 0xffffffff | |
66 | ||
0722db01 P |
67 | void ksym_collect_stats(unsigned long hbp_hit_addr) |
68 | { | |
69 | struct hlist_node *node; | |
70 | struct trace_ksym *entry; | |
71 | ||
72 | rcu_read_lock(); | |
73 | hlist_for_each_entry_rcu(entry, node, &ksym_filter_head, ksym_hlist) { | |
74 | if ((entry->ksym_addr == hbp_hit_addr) && | |
75 | (entry->counter <= MAX_UL_INT)) { | |
76 | entry->counter++; | |
77 | break; | |
78 | } | |
79 | } | |
80 | rcu_read_unlock(); | |
81 | } | |
82 | #endif /* CONFIG_PROFILE_KSYM_TRACER */ | |
83 | ||
24f1e32c | 84 | void ksym_hbp_handler(struct perf_event *hbp, void *data) |
0722db01 P |
85 | { |
86 | struct ring_buffer_event *event; | |
db59504d | 87 | struct ksym_trace_entry *entry; |
24f1e32c | 88 | struct pt_regs *regs = data; |
d6a65dff | 89 | struct ring_buffer *buffer; |
0722db01 P |
90 | int pc; |
91 | ||
92 | if (!ksym_tracing_enabled) | |
93 | return; | |
94 | ||
d6a65dff FW |
95 | buffer = ksym_trace_array->buffer; |
96 | ||
0722db01 P |
97 | pc = preempt_count(); |
98 | ||
d6a65dff | 99 | event = trace_buffer_lock_reserve(buffer, TRACE_KSYM, |
0722db01 P |
100 | sizeof(*entry), 0, pc); |
101 | if (!event) | |
102 | return; | |
103 | ||
db59504d LZ |
104 | entry = ring_buffer_event_data(event); |
105 | entry->ip = instruction_pointer(regs); | |
24f1e32c FW |
106 | entry->type = hw_breakpoint_type(hbp); |
107 | entry->addr = hw_breakpoint_addr(hbp); | |
db59504d LZ |
108 | strlcpy(entry->cmd, current->comm, TASK_COMM_LEN); |
109 | ||
0722db01 | 110 | #ifdef CONFIG_PROFILE_KSYM_TRACER |
24f1e32c | 111 | ksym_collect_stats(hw_breakpoint_addr(hbp)); |
0722db01 P |
112 | #endif /* CONFIG_PROFILE_KSYM_TRACER */ |
113 | ||
d6a65dff | 114 | trace_buffer_unlock_commit(buffer, event, 0, pc); |
0722db01 P |
115 | } |
116 | ||
117 | /* Valid access types are represented as | |
118 | * | |
119 | * rw- : Set Read/Write Access Breakpoint | |
120 | * -w- : Set Write Access Breakpoint | |
121 | * --- : Clear Breakpoints | |
122 | * --x : Set Execution Break points (Not available yet) | |
123 | * | |
124 | */ | |
f088e547 | 125 | static int ksym_trace_get_access_type(char *str) |
0722db01 | 126 | { |
f088e547 | 127 | int access = 0; |
0722db01 | 128 | |
f088e547 | 129 | if (str[0] == 'r') |
24f1e32c | 130 | access |= HW_BREAKPOINT_R; |
f088e547 LZ |
131 | |
132 | if (str[1] == 'w') | |
24f1e32c | 133 | access |= HW_BREAKPOINT_W; |
f088e547 | 134 | |
24f1e32c FW |
135 | if (str[2] == 'x') |
136 | access |= HW_BREAKPOINT_X; | |
0722db01 P |
137 | |
138 | switch (access) { | |
676c0dbe | 139 | case HW_BREAKPOINT_R: |
24f1e32c FW |
140 | case HW_BREAKPOINT_W: |
141 | case HW_BREAKPOINT_W | HW_BREAKPOINT_R: | |
142 | return access; | |
143 | default: | |
144 | return -EINVAL; | |
0722db01 | 145 | } |
0722db01 P |
146 | } |
147 | ||
148 | /* | |
149 | * There can be several possible malformed requests and we attempt to capture | |
150 | * all of them. We enumerate some of the rules | |
151 | * 1. We will not allow kernel symbols with ':' since it is used as a delimiter. | |
152 | * i.e. multiple ':' symbols disallowed. Possible uses are of the form | |
153 | * <module>:<ksym_name>:<op>. | |
154 | * 2. No delimiter symbol ':' in the input string | |
155 | * 3. Spurious operator symbols or symbols not in their respective positions | |
156 | * 4. <ksym_name>:--- i.e. clear breakpoint request when ksym_name not in file | |
157 | * 5. Kernel symbol not a part of /proc/kallsyms | |
158 | * 6. Duplicate requests | |
159 | */ | |
160 | static int parse_ksym_trace_str(char *input_string, char **ksymname, | |
161 | unsigned long *addr) | |
162 | { | |
0722db01 P |
163 | int ret; |
164 | ||
92cf9f8f | 165 | *ksymname = strsep(&input_string, ":"); |
0722db01 P |
166 | *addr = kallsyms_lookup_name(*ksymname); |
167 | ||
168 | /* Check for malformed request: (2), (1) and (5) */ | |
169 | if ((!input_string) || | |
92cf9f8f LZ |
170 | (strlen(input_string) != KSYM_TRACER_OP_LEN) || |
171 | (*addr == 0)) | |
172 | return -EINVAL;; | |
173 | ||
0722db01 P |
174 | ret = ksym_trace_get_access_type(input_string); |
175 | ||
0722db01 P |
176 | return ret; |
177 | } | |
178 | ||
179 | int process_new_ksym_entry(char *ksymname, int op, unsigned long addr) | |
180 | { | |
181 | struct trace_ksym *entry; | |
558df6c8 | 182 | int ret = -ENOMEM; |
0722db01 P |
183 | |
184 | if (ksym_filter_entry_count >= KSYM_TRACER_MAX) { | |
185 | printk(KERN_ERR "ksym_tracer: Maximum limit:(%d) reached. No" | |
186 | " new requests for tracing can be accepted now.\n", | |
187 | KSYM_TRACER_MAX); | |
188 | return -ENOSPC; | |
189 | } | |
190 | ||
191 | entry = kzalloc(sizeof(struct trace_ksym), GFP_KERNEL); | |
192 | if (!entry) | |
193 | return -ENOMEM; | |
194 | ||
24f1e32c FW |
195 | entry->type = op; |
196 | entry->ksym_addr = addr; | |
197 | entry->len = HW_BREAKPOINT_LEN_4; | |
198 | ||
199 | ret = -EAGAIN; | |
200 | entry->ksym_hbp = register_wide_hw_breakpoint(entry->ksym_addr, | |
201 | entry->len, entry->type, | |
202 | ksym_hbp_handler, true); | |
203 | if (IS_ERR(entry->ksym_hbp)) { | |
204 | entry->ksym_hbp = NULL; | |
205 | ret = PTR_ERR(entry->ksym_hbp); | |
206 | } | |
0722db01 | 207 | |
24f1e32c | 208 | if (!entry->ksym_hbp) { |
0722db01 P |
209 | printk(KERN_INFO "ksym_tracer request failed. Try again" |
210 | " later!!\n"); | |
558df6c8 | 211 | goto err; |
0722db01 | 212 | } |
24f1e32c | 213 | |
0722db01 P |
214 | hlist_add_head_rcu(&(entry->ksym_hlist), &ksym_filter_head); |
215 | ksym_filter_entry_count++; | |
24f1e32c | 216 | |
0722db01 | 217 | return 0; |
24f1e32c | 218 | |
558df6c8 | 219 | err: |
558df6c8 | 220 | kfree(entry); |
24f1e32c | 221 | |
558df6c8 | 222 | return ret; |
0722db01 P |
223 | } |
224 | ||
225 | static ssize_t ksym_trace_filter_read(struct file *filp, char __user *ubuf, | |
226 | size_t count, loff_t *ppos) | |
227 | { | |
228 | struct trace_ksym *entry; | |
229 | struct hlist_node *node; | |
be9742e6 LZ |
230 | struct trace_seq *s; |
231 | ssize_t cnt = 0; | |
232 | int ret; | |
233 | ||
234 | s = kmalloc(sizeof(*s), GFP_KERNEL); | |
235 | if (!s) | |
236 | return -ENOMEM; | |
237 | trace_seq_init(s); | |
0722db01 P |
238 | |
239 | mutex_lock(&ksym_tracer_mutex); | |
240 | ||
241 | hlist_for_each_entry(entry, node, &ksym_filter_head, ksym_hlist) { | |
24f1e32c | 242 | ret = trace_seq_printf(s, "%pS:", (void *)entry->ksym_addr); |
676c0dbe PM |
243 | if (entry->type == HW_BREAKPOINT_R) |
244 | ret = trace_seq_puts(s, "r--\n"); | |
245 | else if (entry->type == HW_BREAKPOINT_W) | |
be9742e6 | 246 | ret = trace_seq_puts(s, "-w-\n"); |
24f1e32c | 247 | else if (entry->type == (HW_BREAKPOINT_W | HW_BREAKPOINT_R)) |
be9742e6 LZ |
248 | ret = trace_seq_puts(s, "rw-\n"); |
249 | WARN_ON_ONCE(!ret); | |
0722db01 | 250 | } |
be9742e6 LZ |
251 | |
252 | cnt = simple_read_from_buffer(ubuf, count, ppos, s->buffer, s->len); | |
253 | ||
0722db01 P |
254 | mutex_unlock(&ksym_tracer_mutex); |
255 | ||
be9742e6 LZ |
256 | kfree(s); |
257 | ||
258 | return cnt; | |
0722db01 P |
259 | } |
260 | ||
75e33751 XG |
261 | static void __ksym_trace_reset(void) |
262 | { | |
263 | struct trace_ksym *entry; | |
264 | struct hlist_node *node, *node1; | |
265 | ||
266 | mutex_lock(&ksym_tracer_mutex); | |
267 | hlist_for_each_entry_safe(entry, node, node1, &ksym_filter_head, | |
268 | ksym_hlist) { | |
24f1e32c | 269 | unregister_wide_hw_breakpoint(entry->ksym_hbp); |
75e33751 XG |
270 | ksym_filter_entry_count--; |
271 | hlist_del_rcu(&(entry->ksym_hlist)); | |
272 | synchronize_rcu(); | |
75e33751 XG |
273 | kfree(entry); |
274 | } | |
275 | mutex_unlock(&ksym_tracer_mutex); | |
276 | } | |
277 | ||
0722db01 P |
278 | static ssize_t ksym_trace_filter_write(struct file *file, |
279 | const char __user *buffer, | |
280 | size_t count, loff_t *ppos) | |
281 | { | |
282 | struct trace_ksym *entry; | |
283 | struct hlist_node *node; | |
284 | char *input_string, *ksymname = NULL; | |
285 | unsigned long ksym_addr = 0; | |
286 | int ret, op, changed = 0; | |
287 | ||
011ed568 | 288 | input_string = kzalloc(count + 1, GFP_KERNEL); |
0722db01 P |
289 | if (!input_string) |
290 | return -ENOMEM; | |
291 | ||
292 | if (copy_from_user(input_string, buffer, count)) { | |
293 | kfree(input_string); | |
294 | return -EFAULT; | |
295 | } | |
011ed568 | 296 | input_string[count] = '\0'; |
0722db01 | 297 | |
75e33751 XG |
298 | strstrip(input_string); |
299 | ||
300 | /* | |
301 | * Clear all breakpoints if: | |
302 | * 1: echo > ksym_trace_filter | |
303 | * 2: echo 0 > ksym_trace_filter | |
304 | * 3: echo "*:---" > ksym_trace_filter | |
305 | */ | |
306 | if (!input_string[0] || !strcmp(input_string, "0") || | |
307 | !strcmp(input_string, "*:---")) { | |
308 | __ksym_trace_reset(); | |
309 | kfree(input_string); | |
310 | return count; | |
311 | } | |
312 | ||
0722db01 P |
313 | ret = op = parse_ksym_trace_str(input_string, &ksymname, &ksym_addr); |
314 | if (ret < 0) { | |
315 | kfree(input_string); | |
316 | return ret; | |
317 | } | |
318 | ||
319 | mutex_lock(&ksym_tracer_mutex); | |
320 | ||
321 | ret = -EINVAL; | |
322 | hlist_for_each_entry(entry, node, &ksym_filter_head, ksym_hlist) { | |
323 | if (entry->ksym_addr == ksym_addr) { | |
324 | /* Check for malformed request: (6) */ | |
24f1e32c | 325 | if (entry->type != op) |
0722db01 P |
326 | changed = 1; |
327 | else | |
558df6c8 | 328 | goto out; |
0722db01 P |
329 | break; |
330 | } | |
331 | } | |
332 | if (changed) { | |
24f1e32c FW |
333 | unregister_wide_hw_breakpoint(entry->ksym_hbp); |
334 | entry->type = op; | |
0722db01 | 335 | if (op > 0) { |
24f1e32c FW |
336 | entry->ksym_hbp = |
337 | register_wide_hw_breakpoint(entry->ksym_addr, | |
338 | entry->len, entry->type, | |
339 | ksym_hbp_handler, true); | |
340 | if (IS_ERR(entry->ksym_hbp)) | |
341 | entry->ksym_hbp = NULL; | |
d99be40a FW |
342 | |
343 | /* modified without problem */ | |
344 | if (entry->ksym_hbp) { | |
345 | ret = 0; | |
558df6c8 | 346 | goto out; |
d99be40a FW |
347 | } |
348 | } else { | |
349 | ret = 0; | |
558df6c8 | 350 | } |
d99be40a | 351 | /* Error or "symbol:---" case: drop it */ |
0722db01 P |
352 | ksym_filter_entry_count--; |
353 | hlist_del_rcu(&(entry->ksym_hlist)); | |
354 | synchronize_rcu(); | |
0722db01 | 355 | kfree(entry); |
558df6c8 | 356 | goto out; |
0722db01 P |
357 | } else { |
358 | /* Check for malformed request: (4) */ | |
359 | if (op == 0) | |
558df6c8 | 360 | goto out; |
0722db01 | 361 | ret = process_new_ksym_entry(ksymname, op, ksym_addr); |
0722db01 | 362 | } |
558df6c8 LZ |
363 | out: |
364 | mutex_unlock(&ksym_tracer_mutex); | |
0722db01 | 365 | |
0722db01 P |
366 | kfree(input_string); |
367 | ||
558df6c8 LZ |
368 | if (!ret) |
369 | ret = count; | |
0722db01 P |
370 | return ret; |
371 | } | |
372 | ||
373 | static const struct file_operations ksym_tracing_fops = { | |
374 | .open = tracing_open_generic, | |
375 | .read = ksym_trace_filter_read, | |
376 | .write = ksym_trace_filter_write, | |
377 | }; | |
378 | ||
379 | static void ksym_trace_reset(struct trace_array *tr) | |
380 | { | |
0722db01 | 381 | ksym_tracing_enabled = 0; |
75e33751 | 382 | __ksym_trace_reset(); |
0722db01 P |
383 | } |
384 | ||
385 | static int ksym_trace_init(struct trace_array *tr) | |
386 | { | |
387 | int cpu, ret = 0; | |
388 | ||
389 | for_each_online_cpu(cpu) | |
390 | tracing_reset(tr, cpu); | |
391 | ksym_tracing_enabled = 1; | |
392 | ksym_trace_array = tr; | |
393 | ||
394 | return ret; | |
395 | } | |
396 | ||
397 | static void ksym_trace_print_header(struct seq_file *m) | |
398 | { | |
0722db01 | 399 | seq_puts(m, |
d857ace1 XG |
400 | "# TASK-PID CPU# Symbol " |
401 | "Type Function\n"); | |
0722db01 | 402 | seq_puts(m, |
d857ace1 XG |
403 | "# | | | " |
404 | " | |\n"); | |
0722db01 P |
405 | } |
406 | ||
407 | static enum print_line_t ksym_trace_output(struct trace_iterator *iter) | |
408 | { | |
409 | struct trace_entry *entry = iter->ent; | |
410 | struct trace_seq *s = &iter->seq; | |
db59504d | 411 | struct ksym_trace_entry *field; |
0722db01 P |
412 | char str[KSYM_SYMBOL_LEN]; |
413 | int ret; | |
414 | ||
415 | if (entry->type != TRACE_KSYM) | |
416 | return TRACE_TYPE_UNHANDLED; | |
417 | ||
418 | trace_assign_type(field, entry); | |
419 | ||
24f1e32c FW |
420 | ret = trace_seq_printf(s, "%11s-%-5d [%03d] %pS", field->cmd, |
421 | entry->pid, iter->cpu, (char *)field->addr); | |
0722db01 P |
422 | if (!ret) |
423 | return TRACE_TYPE_PARTIAL_LINE; | |
424 | ||
db59504d | 425 | switch (field->type) { |
676c0dbe PM |
426 | case HW_BREAKPOINT_R: |
427 | ret = trace_seq_printf(s, " R "); | |
428 | break; | |
24f1e32c | 429 | case HW_BREAKPOINT_W: |
0722db01 P |
430 | ret = trace_seq_printf(s, " W "); |
431 | break; | |
24f1e32c | 432 | case HW_BREAKPOINT_R | HW_BREAKPOINT_W: |
0722db01 P |
433 | ret = trace_seq_printf(s, " RW "); |
434 | break; | |
435 | default: | |
436 | return TRACE_TYPE_PARTIAL_LINE; | |
437 | } | |
438 | ||
439 | if (!ret) | |
440 | return TRACE_TYPE_PARTIAL_LINE; | |
441 | ||
442 | sprint_symbol(str, field->ip); | |
d857ace1 | 443 | ret = trace_seq_printf(s, "%s\n", str); |
0722db01 P |
444 | if (!ret) |
445 | return TRACE_TYPE_PARTIAL_LINE; | |
446 | ||
447 | return TRACE_TYPE_HANDLED; | |
448 | } | |
449 | ||
450 | struct tracer ksym_tracer __read_mostly = | |
451 | { | |
452 | .name = "ksym_tracer", | |
453 | .init = ksym_trace_init, | |
454 | .reset = ksym_trace_reset, | |
455 | #ifdef CONFIG_FTRACE_SELFTEST | |
456 | .selftest = trace_selftest_startup_ksym, | |
457 | #endif | |
458 | .print_header = ksym_trace_print_header, | |
459 | .print_line = ksym_trace_output | |
460 | }; | |
461 | ||
462 | __init static int init_ksym_trace(void) | |
463 | { | |
464 | struct dentry *d_tracer; | |
465 | struct dentry *entry; | |
466 | ||
467 | d_tracer = tracing_init_dentry(); | |
468 | ksym_filter_entry_count = 0; | |
469 | ||
470 | entry = debugfs_create_file("ksym_trace_filter", 0644, d_tracer, | |
471 | NULL, &ksym_tracing_fops); | |
472 | if (!entry) | |
473 | pr_warning("Could not create debugfs " | |
474 | "'ksym_trace_filter' file\n"); | |
475 | ||
476 | return register_tracer(&ksym_tracer); | |
477 | } | |
478 | device_initcall(init_ksym_trace); | |
479 | ||
480 | ||
481 | #ifdef CONFIG_PROFILE_KSYM_TRACER | |
482 | static int ksym_tracer_stat_headers(struct seq_file *m) | |
483 | { | |
9d7e9344 LZ |
484 | seq_puts(m, " Access Type "); |
485 | seq_puts(m, " Symbol Counter\n"); | |
486 | seq_puts(m, " ----------- "); | |
487 | seq_puts(m, " ------ -------\n"); | |
0722db01 P |
488 | return 0; |
489 | } | |
490 | ||
491 | static int ksym_tracer_stat_show(struct seq_file *m, void *v) | |
492 | { | |
493 | struct hlist_node *stat = v; | |
494 | struct trace_ksym *entry; | |
495 | int access_type = 0; | |
496 | char fn_name[KSYM_NAME_LEN]; | |
497 | ||
498 | entry = hlist_entry(stat, struct trace_ksym, ksym_hlist); | |
499 | ||
24f1e32c | 500 | access_type = entry->type; |
0722db01 P |
501 | |
502 | switch (access_type) { | |
676c0dbe PM |
503 | case HW_BREAKPOINT_R: |
504 | seq_puts(m, " R "); | |
505 | break; | |
24f1e32c | 506 | case HW_BREAKPOINT_W: |
9d7e9344 | 507 | seq_puts(m, " W "); |
0722db01 | 508 | break; |
24f1e32c | 509 | case HW_BREAKPOINT_R | HW_BREAKPOINT_W: |
9d7e9344 | 510 | seq_puts(m, " RW "); |
0722db01 P |
511 | break; |
512 | default: | |
9d7e9344 | 513 | seq_puts(m, " NA "); |
0722db01 P |
514 | } |
515 | ||
516 | if (lookup_symbol_name(entry->ksym_addr, fn_name) >= 0) | |
9d7e9344 | 517 | seq_printf(m, " %-36s", fn_name); |
0722db01 | 518 | else |
9d7e9344 LZ |
519 | seq_printf(m, " %-36s", "<NA>"); |
520 | seq_printf(m, " %15lu\n", entry->counter); | |
0722db01 | 521 | |
0722db01 P |
522 | return 0; |
523 | } | |
524 | ||
525 | static void *ksym_tracer_stat_start(struct tracer_stat *trace) | |
526 | { | |
9d7e9344 | 527 | return ksym_filter_head.first; |
0722db01 P |
528 | } |
529 | ||
530 | static void * | |
531 | ksym_tracer_stat_next(void *v, int idx) | |
532 | { | |
533 | struct hlist_node *stat = v; | |
534 | ||
535 | return stat->next; | |
536 | } | |
537 | ||
538 | static struct tracer_stat ksym_tracer_stats = { | |
539 | .name = "ksym_tracer", | |
540 | .stat_start = ksym_tracer_stat_start, | |
541 | .stat_next = ksym_tracer_stat_next, | |
542 | .stat_headers = ksym_tracer_stat_headers, | |
543 | .stat_show = ksym_tracer_stat_show | |
544 | }; | |
545 | ||
546 | __init static int ksym_tracer_stat_init(void) | |
547 | { | |
548 | int ret; | |
549 | ||
550 | ret = register_stat_tracer(&ksym_tracer_stats); | |
551 | if (ret) { | |
552 | printk(KERN_WARNING "Warning: could not register " | |
553 | "ksym tracer stats\n"); | |
554 | return 1; | |
555 | } | |
556 | ||
557 | return 0; | |
558 | } | |
559 | fs_initcall(ksym_tracer_stat_init); | |
560 | #endif /* CONFIG_PROFILE_KSYM_TRACER */ |