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Commit | Line | Data |
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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> | |
5a0e3ad6 | 26 | #include <linux/slab.h> |
0722db01 P |
27 | #include <linux/fs.h> |
28 | ||
29 | #include "trace_output.h" | |
0722db01 P |
30 | #include "trace.h" |
31 | ||
24f1e32c FW |
32 | #include <linux/hw_breakpoint.h> |
33 | #include <asm/hw_breakpoint.h> | |
34 | ||
e6d9491b LZ |
35 | #include <asm/atomic.h> |
36 | ||
24f1e32c FW |
37 | /* |
38 | * For now, let us restrict the no. of symbols traced simultaneously to number | |
0722db01 P |
39 | * of available hardware breakpoint registers. |
40 | */ | |
41 | #define KSYM_TRACER_MAX HBP_NUM | |
42 | ||
43 | #define KSYM_TRACER_OP_LEN 3 /* rw- */ | |
0722db01 | 44 | |
db59504d | 45 | struct trace_ksym { |
24f1e32c | 46 | struct perf_event **ksym_hbp; |
dd1853c3 | 47 | struct perf_event_attr attr; |
db59504d | 48 | #ifdef CONFIG_PROFILE_KSYM_TRACER |
e6d9491b | 49 | atomic64_t counter; |
db59504d LZ |
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) { | |
e6d9491b LZ |
74 | if (entry->attr.bp_addr == hbp_hit_addr) { |
75 | atomic64_inc(&entry->counter); | |
0722db01 P |
76 | break; |
77 | } | |
78 | } | |
79 | rcu_read_unlock(); | |
80 | } | |
81 | #endif /* CONFIG_PROFILE_KSYM_TRACER */ | |
82 | ||
b326e956 FW |
83 | void ksym_hbp_handler(struct perf_event *hbp, int nmi, |
84 | struct perf_sample_data *data, | |
85 | struct pt_regs *regs) | |
0722db01 P |
86 | { |
87 | struct ring_buffer_event *event; | |
db59504d | 88 | struct ksym_trace_entry *entry; |
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 | ||
dd1853c3 FW |
195 | hw_breakpoint_init(&entry->attr); |
196 | ||
197 | entry->attr.bp_type = op; | |
198 | entry->attr.bp_addr = addr; | |
199 | entry->attr.bp_len = HW_BREAKPOINT_LEN_4; | |
24f1e32c | 200 | |
dd1853c3 FW |
201 | entry->ksym_hbp = register_wide_hw_breakpoint(&entry->attr, |
202 | ksym_hbp_handler); | |
605bfaee | 203 | |
24f1e32c | 204 | if (IS_ERR(entry->ksym_hbp)) { |
24f1e32c | 205 | ret = PTR_ERR(entry->ksym_hbp); |
0722db01 P |
206 | printk(KERN_INFO "ksym_tracer request failed. Try again" |
207 | " later!!\n"); | |
558df6c8 | 208 | goto err; |
0722db01 | 209 | } |
24f1e32c | 210 | |
0722db01 P |
211 | hlist_add_head_rcu(&(entry->ksym_hlist), &ksym_filter_head); |
212 | ksym_filter_entry_count++; | |
24f1e32c | 213 | |
0722db01 | 214 | return 0; |
24f1e32c | 215 | |
558df6c8 | 216 | err: |
558df6c8 | 217 | kfree(entry); |
24f1e32c | 218 | |
558df6c8 | 219 | return ret; |
0722db01 P |
220 | } |
221 | ||
222 | static ssize_t ksym_trace_filter_read(struct file *filp, char __user *ubuf, | |
223 | size_t count, loff_t *ppos) | |
224 | { | |
225 | struct trace_ksym *entry; | |
226 | struct hlist_node *node; | |
be9742e6 LZ |
227 | struct trace_seq *s; |
228 | ssize_t cnt = 0; | |
229 | int ret; | |
230 | ||
231 | s = kmalloc(sizeof(*s), GFP_KERNEL); | |
232 | if (!s) | |
233 | return -ENOMEM; | |
234 | trace_seq_init(s); | |
0722db01 P |
235 | |
236 | mutex_lock(&ksym_tracer_mutex); | |
237 | ||
238 | hlist_for_each_entry(entry, node, &ksym_filter_head, ksym_hlist) { | |
16620e0f LZ |
239 | ret = trace_seq_printf(s, "%pS:", |
240 | (void *)(unsigned long)entry->attr.bp_addr); | |
dd1853c3 | 241 | if (entry->attr.bp_type == HW_BREAKPOINT_R) |
676c0dbe | 242 | ret = trace_seq_puts(s, "r--\n"); |
dd1853c3 | 243 | else if (entry->attr.bp_type == HW_BREAKPOINT_W) |
be9742e6 | 244 | ret = trace_seq_puts(s, "-w-\n"); |
dd1853c3 | 245 | else if (entry->attr.bp_type == (HW_BREAKPOINT_W | HW_BREAKPOINT_R)) |
be9742e6 LZ |
246 | ret = trace_seq_puts(s, "rw-\n"); |
247 | WARN_ON_ONCE(!ret); | |
0722db01 | 248 | } |
be9742e6 LZ |
249 | |
250 | cnt = simple_read_from_buffer(ubuf, count, ppos, s->buffer, s->len); | |
251 | ||
0722db01 P |
252 | mutex_unlock(&ksym_tracer_mutex); |
253 | ||
be9742e6 LZ |
254 | kfree(s); |
255 | ||
256 | return cnt; | |
0722db01 P |
257 | } |
258 | ||
75e33751 XG |
259 | static void __ksym_trace_reset(void) |
260 | { | |
261 | struct trace_ksym *entry; | |
262 | struct hlist_node *node, *node1; | |
263 | ||
264 | mutex_lock(&ksym_tracer_mutex); | |
265 | hlist_for_each_entry_safe(entry, node, node1, &ksym_filter_head, | |
266 | ksym_hlist) { | |
24f1e32c | 267 | unregister_wide_hw_breakpoint(entry->ksym_hbp); |
75e33751 XG |
268 | ksym_filter_entry_count--; |
269 | hlist_del_rcu(&(entry->ksym_hlist)); | |
270 | synchronize_rcu(); | |
75e33751 XG |
271 | kfree(entry); |
272 | } | |
273 | mutex_unlock(&ksym_tracer_mutex); | |
274 | } | |
275 | ||
0722db01 P |
276 | static ssize_t ksym_trace_filter_write(struct file *file, |
277 | const char __user *buffer, | |
278 | size_t count, loff_t *ppos) | |
279 | { | |
280 | struct trace_ksym *entry; | |
281 | struct hlist_node *node; | |
d954fbf0 | 282 | char *buf, *input_string, *ksymname = NULL; |
0722db01 P |
283 | unsigned long ksym_addr = 0; |
284 | int ret, op, changed = 0; | |
285 | ||
d954fbf0 TG |
286 | buf = kzalloc(count + 1, GFP_KERNEL); |
287 | if (!buf) | |
0722db01 P |
288 | return -ENOMEM; |
289 | ||
d954fbf0 TG |
290 | ret = -EFAULT; |
291 | if (copy_from_user(buf, buffer, count)) | |
292 | goto out; | |
0722db01 | 293 | |
d954fbf0 TG |
294 | buf[count] = '\0'; |
295 | input_string = strstrip(buf); | |
75e33751 XG |
296 | |
297 | /* | |
298 | * Clear all breakpoints if: | |
299 | * 1: echo > ksym_trace_filter | |
300 | * 2: echo 0 > ksym_trace_filter | |
301 | * 3: echo "*:---" > ksym_trace_filter | |
302 | */ | |
3d13ec2e LZ |
303 | if (!input_string[0] || !strcmp(input_string, "0") || |
304 | !strcmp(input_string, "*:---")) { | |
75e33751 | 305 | __ksym_trace_reset(); |
d954fbf0 TG |
306 | ret = 0; |
307 | goto out; | |
75e33751 XG |
308 | } |
309 | ||
0722db01 | 310 | ret = op = parse_ksym_trace_str(input_string, &ksymname, &ksym_addr); |
d954fbf0 TG |
311 | if (ret < 0) |
312 | goto out; | |
0722db01 P |
313 | |
314 | mutex_lock(&ksym_tracer_mutex); | |
315 | ||
316 | ret = -EINVAL; | |
317 | hlist_for_each_entry(entry, node, &ksym_filter_head, ksym_hlist) { | |
dd1853c3 | 318 | if (entry->attr.bp_addr == ksym_addr) { |
0722db01 | 319 | /* Check for malformed request: (6) */ |
dd1853c3 | 320 | if (entry->attr.bp_type != op) |
0722db01 P |
321 | changed = 1; |
322 | else | |
d954fbf0 | 323 | goto out_unlock; |
0722db01 P |
324 | break; |
325 | } | |
326 | } | |
327 | if (changed) { | |
24f1e32c | 328 | unregister_wide_hw_breakpoint(entry->ksym_hbp); |
dd1853c3 | 329 | entry->attr.bp_type = op; |
605bfaee | 330 | ret = 0; |
0722db01 | 331 | if (op > 0) { |
24f1e32c | 332 | entry->ksym_hbp = |
dd1853c3 FW |
333 | register_wide_hw_breakpoint(&entry->attr, |
334 | ksym_hbp_handler); | |
24f1e32c | 335 | if (IS_ERR(entry->ksym_hbp)) |
605bfaee FW |
336 | ret = PTR_ERR(entry->ksym_hbp); |
337 | else | |
d954fbf0 | 338 | goto out_unlock; |
558df6c8 | 339 | } |
d99be40a | 340 | /* Error or "symbol:---" case: drop it */ |
0722db01 P |
341 | ksym_filter_entry_count--; |
342 | hlist_del_rcu(&(entry->ksym_hlist)); | |
343 | synchronize_rcu(); | |
0722db01 | 344 | kfree(entry); |
d954fbf0 | 345 | goto out_unlock; |
0722db01 P |
346 | } else { |
347 | /* Check for malformed request: (4) */ | |
d954fbf0 TG |
348 | if (op) |
349 | ret = process_new_ksym_entry(ksymname, op, ksym_addr); | |
0722db01 | 350 | } |
d954fbf0 | 351 | out_unlock: |
558df6c8 | 352 | mutex_unlock(&ksym_tracer_mutex); |
d954fbf0 TG |
353 | out: |
354 | kfree(buf); | |
355 | return !ret ? count : ret; | |
0722db01 P |
356 | } |
357 | ||
358 | static const struct file_operations ksym_tracing_fops = { | |
359 | .open = tracing_open_generic, | |
360 | .read = ksym_trace_filter_read, | |
361 | .write = ksym_trace_filter_write, | |
362 | }; | |
363 | ||
364 | static void ksym_trace_reset(struct trace_array *tr) | |
365 | { | |
0722db01 | 366 | ksym_tracing_enabled = 0; |
75e33751 | 367 | __ksym_trace_reset(); |
0722db01 P |
368 | } |
369 | ||
370 | static int ksym_trace_init(struct trace_array *tr) | |
371 | { | |
372 | int cpu, ret = 0; | |
373 | ||
374 | for_each_online_cpu(cpu) | |
375 | tracing_reset(tr, cpu); | |
376 | ksym_tracing_enabled = 1; | |
377 | ksym_trace_array = tr; | |
378 | ||
379 | return ret; | |
380 | } | |
381 | ||
382 | static void ksym_trace_print_header(struct seq_file *m) | |
383 | { | |
0722db01 | 384 | seq_puts(m, |
d857ace1 XG |
385 | "# TASK-PID CPU# Symbol " |
386 | "Type Function\n"); | |
0722db01 | 387 | seq_puts(m, |
d857ace1 XG |
388 | "# | | | " |
389 | " | |\n"); | |
0722db01 P |
390 | } |
391 | ||
392 | static enum print_line_t ksym_trace_output(struct trace_iterator *iter) | |
393 | { | |
394 | struct trace_entry *entry = iter->ent; | |
395 | struct trace_seq *s = &iter->seq; | |
db59504d | 396 | struct ksym_trace_entry *field; |
0722db01 P |
397 | char str[KSYM_SYMBOL_LEN]; |
398 | int ret; | |
399 | ||
400 | if (entry->type != TRACE_KSYM) | |
401 | return TRACE_TYPE_UNHANDLED; | |
402 | ||
403 | trace_assign_type(field, entry); | |
404 | ||
24f1e32c FW |
405 | ret = trace_seq_printf(s, "%11s-%-5d [%03d] %pS", field->cmd, |
406 | entry->pid, iter->cpu, (char *)field->addr); | |
0722db01 P |
407 | if (!ret) |
408 | return TRACE_TYPE_PARTIAL_LINE; | |
409 | ||
db59504d | 410 | switch (field->type) { |
676c0dbe PM |
411 | case HW_BREAKPOINT_R: |
412 | ret = trace_seq_printf(s, " R "); | |
413 | break; | |
24f1e32c | 414 | case HW_BREAKPOINT_W: |
0722db01 P |
415 | ret = trace_seq_printf(s, " W "); |
416 | break; | |
24f1e32c | 417 | case HW_BREAKPOINT_R | HW_BREAKPOINT_W: |
0722db01 P |
418 | ret = trace_seq_printf(s, " RW "); |
419 | break; | |
420 | default: | |
421 | return TRACE_TYPE_PARTIAL_LINE; | |
422 | } | |
423 | ||
424 | if (!ret) | |
425 | return TRACE_TYPE_PARTIAL_LINE; | |
426 | ||
427 | sprint_symbol(str, field->ip); | |
d857ace1 | 428 | ret = trace_seq_printf(s, "%s\n", str); |
0722db01 P |
429 | if (!ret) |
430 | return TRACE_TYPE_PARTIAL_LINE; | |
431 | ||
432 | return TRACE_TYPE_HANDLED; | |
433 | } | |
434 | ||
435 | struct tracer ksym_tracer __read_mostly = | |
436 | { | |
437 | .name = "ksym_tracer", | |
438 | .init = ksym_trace_init, | |
439 | .reset = ksym_trace_reset, | |
440 | #ifdef CONFIG_FTRACE_SELFTEST | |
441 | .selftest = trace_selftest_startup_ksym, | |
442 | #endif | |
443 | .print_header = ksym_trace_print_header, | |
444 | .print_line = ksym_trace_output | |
445 | }; | |
446 | ||
0722db01 | 447 | #ifdef CONFIG_PROFILE_KSYM_TRACER |
53ab6680 | 448 | static int ksym_profile_show(struct seq_file *m, void *v) |
0722db01 | 449 | { |
53ab6680 LZ |
450 | struct hlist_node *node; |
451 | struct trace_ksym *entry; | |
452 | int access_type = 0; | |
453 | char fn_name[KSYM_NAME_LEN]; | |
454 | ||
9d7e9344 LZ |
455 | seq_puts(m, " Access Type "); |
456 | seq_puts(m, " Symbol Counter\n"); | |
457 | seq_puts(m, " ----------- "); | |
458 | seq_puts(m, " ------ -------\n"); | |
0722db01 | 459 | |
53ab6680 LZ |
460 | rcu_read_lock(); |
461 | hlist_for_each_entry_rcu(entry, node, &ksym_filter_head, ksym_hlist) { | |
0722db01 | 462 | |
53ab6680 | 463 | access_type = entry->attr.bp_type; |
0722db01 | 464 | |
53ab6680 LZ |
465 | switch (access_type) { |
466 | case HW_BREAKPOINT_R: | |
467 | seq_puts(m, " R "); | |
468 | break; | |
469 | case HW_BREAKPOINT_W: | |
470 | seq_puts(m, " W "); | |
471 | break; | |
472 | case HW_BREAKPOINT_R | HW_BREAKPOINT_W: | |
473 | seq_puts(m, " RW "); | |
474 | break; | |
475 | default: | |
476 | seq_puts(m, " NA "); | |
477 | } | |
0722db01 | 478 | |
53ab6680 LZ |
479 | if (lookup_symbol_name(entry->attr.bp_addr, fn_name) >= 0) |
480 | seq_printf(m, " %-36s", fn_name); | |
481 | else | |
482 | seq_printf(m, " %-36s", "<NA>"); | |
483 | seq_printf(m, " %15llu\n", | |
484 | (unsigned long long)atomic64_read(&entry->counter)); | |
0722db01 | 485 | } |
53ab6680 | 486 | rcu_read_unlock(); |
0722db01 | 487 | |
0722db01 P |
488 | return 0; |
489 | } | |
490 | ||
53ab6680 | 491 | static int ksym_profile_open(struct inode *node, struct file *file) |
0722db01 | 492 | { |
53ab6680 | 493 | return single_open(file, ksym_profile_show, NULL); |
0722db01 P |
494 | } |
495 | ||
53ab6680 LZ |
496 | static const struct file_operations ksym_profile_fops = { |
497 | .open = ksym_profile_open, | |
498 | .read = seq_read, | |
499 | .llseek = seq_lseek, | |
500 | .release = single_release, | |
0722db01 | 501 | }; |
53ab6680 | 502 | #endif /* CONFIG_PROFILE_KSYM_TRACER */ |
0722db01 | 503 | |
53ab6680 | 504 | __init static int init_ksym_trace(void) |
0722db01 | 505 | { |
53ab6680 | 506 | struct dentry *d_tracer; |
0722db01 | 507 | |
53ab6680 | 508 | d_tracer = tracing_init_dentry(); |
0722db01 | 509 | |
53ab6680 LZ |
510 | trace_create_file("ksym_trace_filter", 0644, d_tracer, |
511 | NULL, &ksym_tracing_fops); | |
512 | ||
513 | #ifdef CONFIG_PROFILE_KSYM_TRACER | |
514 | trace_create_file("ksym_profile", 0444, d_tracer, | |
515 | NULL, &ksym_profile_fops); | |
516 | #endif | |
517 | ||
518 | return register_tracer(&ksym_tracer); | |
0722db01 | 519 | } |
53ab6680 | 520 | device_initcall(init_ksym_trace); |