]>
Commit | Line | Data |
---|---|---|
413d37d1 | 1 | /* |
77b44d1b | 2 | * Kprobes-based tracing events |
413d37d1 MH |
3 | * |
4 | * Created by Masami Hiramatsu <mhiramat@redhat.com> | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License version 2 as | |
8 | * published by the Free Software Foundation. | |
9 | * | |
10 | * This program is distributed in the hope that it will be useful, | |
11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
13 | * GNU General Public License for more details. | |
14 | * | |
15 | * You should have received a copy of the GNU General Public License | |
16 | * along with this program; if not, write to the Free Software | |
17 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
18 | */ | |
19 | ||
20 | #include <linux/module.h> | |
21 | #include <linux/uaccess.h> | |
22 | #include <linux/kprobes.h> | |
23 | #include <linux/seq_file.h> | |
24 | #include <linux/slab.h> | |
25 | #include <linux/smp.h> | |
26 | #include <linux/debugfs.h> | |
27 | #include <linux/types.h> | |
28 | #include <linux/string.h> | |
29 | #include <linux/ctype.h> | |
30 | #include <linux/ptrace.h> | |
d7a4b414 | 31 | #include <linux/perf_event.h> |
413d37d1 MH |
32 | |
33 | #include "trace.h" | |
34 | #include "trace_output.h" | |
35 | ||
a82378d8 | 36 | #define MAX_TRACE_ARGS 128 |
413d37d1 | 37 | #define MAX_ARGSTR_LEN 63 |
4263565d | 38 | #define MAX_EVENT_NAME_LEN 64 |
f52487e9 | 39 | #define KPROBE_EVENT_SYSTEM "kprobes" |
413d37d1 | 40 | |
a703d946 | 41 | /* Reserved field names */ |
e93f4d85 MH |
42 | #define FIELD_STRING_IP "__probe_ip" |
43 | #define FIELD_STRING_NARGS "__probe_nargs" | |
44 | #define FIELD_STRING_RETIP "__probe_ret_ip" | |
45 | #define FIELD_STRING_FUNC "__probe_func" | |
a703d946 MH |
46 | |
47 | const char *reserved_field_names[] = { | |
48 | "common_type", | |
49 | "common_flags", | |
50 | "common_preempt_count", | |
51 | "common_pid", | |
52 | "common_tgid", | |
53 | "common_lock_depth", | |
54 | FIELD_STRING_IP, | |
55 | FIELD_STRING_NARGS, | |
56 | FIELD_STRING_RETIP, | |
57 | FIELD_STRING_FUNC, | |
58 | }; | |
59 | ||
413d37d1 MH |
60 | struct fetch_func { |
61 | unsigned long (*func)(struct pt_regs *, void *); | |
62 | void *data; | |
63 | }; | |
64 | ||
65 | static __kprobes unsigned long call_fetch(struct fetch_func *f, | |
66 | struct pt_regs *regs) | |
67 | { | |
68 | return f->func(regs, f->data); | |
69 | } | |
70 | ||
71 | /* fetch handlers */ | |
72 | static __kprobes unsigned long fetch_register(struct pt_regs *regs, | |
73 | void *offset) | |
74 | { | |
75 | return regs_get_register(regs, (unsigned int)((unsigned long)offset)); | |
76 | } | |
77 | ||
78 | static __kprobes unsigned long fetch_stack(struct pt_regs *regs, | |
79 | void *num) | |
80 | { | |
81 | return regs_get_kernel_stack_nth(regs, | |
82 | (unsigned int)((unsigned long)num)); | |
83 | } | |
84 | ||
85 | static __kprobes unsigned long fetch_memory(struct pt_regs *regs, void *addr) | |
86 | { | |
87 | unsigned long retval; | |
88 | ||
89 | if (probe_kernel_address(addr, retval)) | |
90 | return 0; | |
91 | return retval; | |
92 | } | |
93 | ||
413d37d1 MH |
94 | static __kprobes unsigned long fetch_retvalue(struct pt_regs *regs, |
95 | void *dummy) | |
96 | { | |
97 | return regs_return_value(regs); | |
98 | } | |
99 | ||
413d37d1 MH |
100 | static __kprobes unsigned long fetch_stack_address(struct pt_regs *regs, |
101 | void *dummy) | |
102 | { | |
103 | return kernel_stack_pointer(regs); | |
104 | } | |
105 | ||
106 | /* Memory fetching by symbol */ | |
107 | struct symbol_cache { | |
108 | char *symbol; | |
109 | long offset; | |
110 | unsigned long addr; | |
111 | }; | |
112 | ||
113 | static unsigned long update_symbol_cache(struct symbol_cache *sc) | |
114 | { | |
115 | sc->addr = (unsigned long)kallsyms_lookup_name(sc->symbol); | |
116 | if (sc->addr) | |
117 | sc->addr += sc->offset; | |
118 | return sc->addr; | |
119 | } | |
120 | ||
121 | static void free_symbol_cache(struct symbol_cache *sc) | |
122 | { | |
123 | kfree(sc->symbol); | |
124 | kfree(sc); | |
125 | } | |
126 | ||
127 | static struct symbol_cache *alloc_symbol_cache(const char *sym, long offset) | |
128 | { | |
129 | struct symbol_cache *sc; | |
130 | ||
131 | if (!sym || strlen(sym) == 0) | |
132 | return NULL; | |
133 | sc = kzalloc(sizeof(struct symbol_cache), GFP_KERNEL); | |
134 | if (!sc) | |
135 | return NULL; | |
136 | ||
137 | sc->symbol = kstrdup(sym, GFP_KERNEL); | |
138 | if (!sc->symbol) { | |
139 | kfree(sc); | |
140 | return NULL; | |
141 | } | |
142 | sc->offset = offset; | |
143 | ||
144 | update_symbol_cache(sc); | |
145 | return sc; | |
146 | } | |
147 | ||
148 | static __kprobes unsigned long fetch_symbol(struct pt_regs *regs, void *data) | |
149 | { | |
150 | struct symbol_cache *sc = data; | |
151 | ||
152 | if (sc->addr) | |
153 | return fetch_memory(regs, (void *)sc->addr); | |
154 | else | |
155 | return 0; | |
156 | } | |
157 | ||
158 | /* Special indirect memory access interface */ | |
159 | struct indirect_fetch_data { | |
160 | struct fetch_func orig; | |
161 | long offset; | |
162 | }; | |
163 | ||
164 | static __kprobes unsigned long fetch_indirect(struct pt_regs *regs, void *data) | |
165 | { | |
166 | struct indirect_fetch_data *ind = data; | |
167 | unsigned long addr; | |
168 | ||
169 | addr = call_fetch(&ind->orig, regs); | |
170 | if (addr) { | |
171 | addr += ind->offset; | |
172 | return fetch_memory(regs, (void *)addr); | |
173 | } else | |
174 | return 0; | |
175 | } | |
176 | ||
177 | static __kprobes void free_indirect_fetch_data(struct indirect_fetch_data *data) | |
178 | { | |
179 | if (data->orig.func == fetch_indirect) | |
180 | free_indirect_fetch_data(data->orig.data); | |
181 | else if (data->orig.func == fetch_symbol) | |
182 | free_symbol_cache(data->orig.data); | |
183 | kfree(data); | |
184 | } | |
185 | ||
186 | /** | |
77b44d1b | 187 | * Kprobe event core functions |
413d37d1 MH |
188 | */ |
189 | ||
eca0d916 MH |
190 | struct probe_arg { |
191 | struct fetch_func fetch; | |
192 | const char *name; | |
193 | }; | |
194 | ||
50d78056 MH |
195 | /* Flags for trace_probe */ |
196 | #define TP_FLAG_TRACE 1 | |
197 | #define TP_FLAG_PROFILE 2 | |
198 | ||
413d37d1 MH |
199 | struct trace_probe { |
200 | struct list_head list; | |
4a846b44 | 201 | struct kretprobe rp; /* Use rp.kp for kprobe use */ |
cd7e7bd5 | 202 | unsigned long nhit; |
50d78056 | 203 | unsigned int flags; /* For TP_FLAG_* */ |
413d37d1 | 204 | const char *symbol; /* symbol name */ |
413d37d1 | 205 | struct ftrace_event_call call; |
ff50d991 | 206 | struct trace_event event; |
a82378d8 | 207 | unsigned int nr_args; |
eca0d916 | 208 | struct probe_arg args[]; |
413d37d1 MH |
209 | }; |
210 | ||
a82378d8 MH |
211 | #define SIZEOF_TRACE_PROBE(n) \ |
212 | (offsetof(struct trace_probe, args) + \ | |
eca0d916 | 213 | (sizeof(struct probe_arg) * (n))) |
a82378d8 | 214 | |
413d37d1 MH |
215 | static __kprobes int probe_is_return(struct trace_probe *tp) |
216 | { | |
4a846b44 | 217 | return tp->rp.handler != NULL; |
413d37d1 MH |
218 | } |
219 | ||
220 | static __kprobes const char *probe_symbol(struct trace_probe *tp) | |
221 | { | |
222 | return tp->symbol ? tp->symbol : "unknown"; | |
223 | } | |
224 | ||
30a7e073 | 225 | static int probe_arg_string(char *buf, size_t n, struct fetch_func *ff) |
413d37d1 MH |
226 | { |
227 | int ret = -EINVAL; | |
228 | ||
14640106 | 229 | if (ff->func == fetch_register) { |
413d37d1 MH |
230 | const char *name; |
231 | name = regs_query_register_name((unsigned int)((long)ff->data)); | |
232 | ret = snprintf(buf, n, "%%%s", name); | |
233 | } else if (ff->func == fetch_stack) | |
2e06ff63 | 234 | ret = snprintf(buf, n, "$stack%lu", (unsigned long)ff->data); |
413d37d1 MH |
235 | else if (ff->func == fetch_memory) |
236 | ret = snprintf(buf, n, "@0x%p", ff->data); | |
237 | else if (ff->func == fetch_symbol) { | |
238 | struct symbol_cache *sc = ff->data; | |
52a11f35 LJ |
239 | if (sc->offset) |
240 | ret = snprintf(buf, n, "@%s%+ld", sc->symbol, | |
241 | sc->offset); | |
242 | else | |
243 | ret = snprintf(buf, n, "@%s", sc->symbol); | |
413d37d1 | 244 | } else if (ff->func == fetch_retvalue) |
2e06ff63 | 245 | ret = snprintf(buf, n, "$retval"); |
413d37d1 | 246 | else if (ff->func == fetch_stack_address) |
2e06ff63 | 247 | ret = snprintf(buf, n, "$stack"); |
413d37d1 MH |
248 | else if (ff->func == fetch_indirect) { |
249 | struct indirect_fetch_data *id = ff->data; | |
250 | size_t l = 0; | |
251 | ret = snprintf(buf, n, "%+ld(", id->offset); | |
252 | if (ret >= n) | |
253 | goto end; | |
254 | l += ret; | |
30a7e073 | 255 | ret = probe_arg_string(buf + l, n - l, &id->orig); |
413d37d1 MH |
256 | if (ret < 0) |
257 | goto end; | |
258 | l += ret; | |
259 | ret = snprintf(buf + l, n - l, ")"); | |
260 | ret += l; | |
261 | } | |
262 | end: | |
263 | if (ret >= n) | |
264 | return -ENOSPC; | |
265 | return ret; | |
266 | } | |
267 | ||
268 | static int register_probe_event(struct trace_probe *tp); | |
269 | static void unregister_probe_event(struct trace_probe *tp); | |
270 | ||
271 | static DEFINE_MUTEX(probe_lock); | |
272 | static LIST_HEAD(probe_list); | |
273 | ||
50d78056 MH |
274 | static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs); |
275 | static int kretprobe_dispatcher(struct kretprobe_instance *ri, | |
276 | struct pt_regs *regs); | |
277 | ||
6f3cf440 MH |
278 | /* Check the name is good for event/group */ |
279 | static int check_event_name(const char *name) | |
280 | { | |
281 | if (!isalpha(*name) && *name != '_') | |
282 | return 0; | |
283 | while (*++name != '\0') { | |
284 | if (!isalpha(*name) && !isdigit(*name) && *name != '_') | |
285 | return 0; | |
286 | } | |
287 | return 1; | |
288 | } | |
289 | ||
4a846b44 MH |
290 | /* |
291 | * Allocate new trace_probe and initialize it (including kprobes). | |
292 | */ | |
f52487e9 MH |
293 | static struct trace_probe *alloc_trace_probe(const char *group, |
294 | const char *event, | |
4a846b44 MH |
295 | void *addr, |
296 | const char *symbol, | |
297 | unsigned long offs, | |
298 | int nargs, int is_return) | |
413d37d1 MH |
299 | { |
300 | struct trace_probe *tp; | |
6f3cf440 | 301 | int ret = -ENOMEM; |
413d37d1 | 302 | |
a82378d8 | 303 | tp = kzalloc(SIZEOF_TRACE_PROBE(nargs), GFP_KERNEL); |
413d37d1 | 304 | if (!tp) |
6f3cf440 | 305 | return ERR_PTR(ret); |
413d37d1 MH |
306 | |
307 | if (symbol) { | |
308 | tp->symbol = kstrdup(symbol, GFP_KERNEL); | |
309 | if (!tp->symbol) | |
310 | goto error; | |
4a846b44 MH |
311 | tp->rp.kp.symbol_name = tp->symbol; |
312 | tp->rp.kp.offset = offs; | |
313 | } else | |
314 | tp->rp.kp.addr = addr; | |
315 | ||
316 | if (is_return) | |
50d78056 | 317 | tp->rp.handler = kretprobe_dispatcher; |
4a846b44 | 318 | else |
50d78056 | 319 | tp->rp.kp.pre_handler = kprobe_dispatcher; |
4a846b44 | 320 | |
6f3cf440 MH |
321 | if (!event || !check_event_name(event)) { |
322 | ret = -EINVAL; | |
4263565d | 323 | goto error; |
6f3cf440 MH |
324 | } |
325 | ||
4263565d MH |
326 | tp->call.name = kstrdup(event, GFP_KERNEL); |
327 | if (!tp->call.name) | |
328 | goto error; | |
413d37d1 | 329 | |
6f3cf440 MH |
330 | if (!group || !check_event_name(group)) { |
331 | ret = -EINVAL; | |
f52487e9 | 332 | goto error; |
6f3cf440 MH |
333 | } |
334 | ||
f52487e9 MH |
335 | tp->call.system = kstrdup(group, GFP_KERNEL); |
336 | if (!tp->call.system) | |
337 | goto error; | |
338 | ||
413d37d1 MH |
339 | INIT_LIST_HEAD(&tp->list); |
340 | return tp; | |
341 | error: | |
f52487e9 | 342 | kfree(tp->call.name); |
413d37d1 MH |
343 | kfree(tp->symbol); |
344 | kfree(tp); | |
6f3cf440 | 345 | return ERR_PTR(ret); |
413d37d1 MH |
346 | } |
347 | ||
eca0d916 MH |
348 | static void free_probe_arg(struct probe_arg *arg) |
349 | { | |
350 | if (arg->fetch.func == fetch_symbol) | |
351 | free_symbol_cache(arg->fetch.data); | |
352 | else if (arg->fetch.func == fetch_indirect) | |
353 | free_indirect_fetch_data(arg->fetch.data); | |
354 | kfree(arg->name); | |
355 | } | |
356 | ||
413d37d1 MH |
357 | static void free_trace_probe(struct trace_probe *tp) |
358 | { | |
359 | int i; | |
360 | ||
361 | for (i = 0; i < tp->nr_args; i++) | |
eca0d916 | 362 | free_probe_arg(&tp->args[i]); |
413d37d1 | 363 | |
f52487e9 | 364 | kfree(tp->call.system); |
413d37d1 MH |
365 | kfree(tp->call.name); |
366 | kfree(tp->symbol); | |
367 | kfree(tp); | |
368 | } | |
369 | ||
dd004c47 MH |
370 | static struct trace_probe *find_probe_event(const char *event, |
371 | const char *group) | |
413d37d1 MH |
372 | { |
373 | struct trace_probe *tp; | |
374 | ||
375 | list_for_each_entry(tp, &probe_list, list) | |
dd004c47 MH |
376 | if (strcmp(tp->call.name, event) == 0 && |
377 | strcmp(tp->call.system, group) == 0) | |
413d37d1 MH |
378 | return tp; |
379 | return NULL; | |
380 | } | |
381 | ||
2d5e067e MH |
382 | /* Unregister a trace_probe and probe_event: call with locking probe_lock */ |
383 | static void unregister_trace_probe(struct trace_probe *tp) | |
413d37d1 MH |
384 | { |
385 | if (probe_is_return(tp)) | |
386 | unregister_kretprobe(&tp->rp); | |
387 | else | |
4a846b44 | 388 | unregister_kprobe(&tp->rp.kp); |
413d37d1 | 389 | list_del(&tp->list); |
2d5e067e | 390 | unregister_probe_event(tp); |
413d37d1 MH |
391 | } |
392 | ||
393 | /* Register a trace_probe and probe_event */ | |
394 | static int register_trace_probe(struct trace_probe *tp) | |
395 | { | |
396 | struct trace_probe *old_tp; | |
397 | int ret; | |
398 | ||
399 | mutex_lock(&probe_lock); | |
400 | ||
2d5e067e | 401 | /* register as an event */ |
dd004c47 | 402 | old_tp = find_probe_event(tp->call.name, tp->call.system); |
2d5e067e MH |
403 | if (old_tp) { |
404 | /* delete old event */ | |
405 | unregister_trace_probe(old_tp); | |
406 | free_trace_probe(old_tp); | |
407 | } | |
408 | ret = register_probe_event(tp); | |
409 | if (ret) { | |
410 | pr_warning("Faild to register probe event(%d)\n", ret); | |
411 | goto end; | |
412 | } | |
413 | ||
5a0d9050 | 414 | tp->rp.kp.flags |= KPROBE_FLAG_DISABLED; |
413d37d1 MH |
415 | if (probe_is_return(tp)) |
416 | ret = register_kretprobe(&tp->rp); | |
417 | else | |
4a846b44 | 418 | ret = register_kprobe(&tp->rp.kp); |
413d37d1 MH |
419 | |
420 | if (ret) { | |
421 | pr_warning("Could not insert probe(%d)\n", ret); | |
422 | if (ret == -EILSEQ) { | |
423 | pr_warning("Probing address(0x%p) is not an " | |
424 | "instruction boundary.\n", | |
4a846b44 | 425 | tp->rp.kp.addr); |
413d37d1 MH |
426 | ret = -EINVAL; |
427 | } | |
2d5e067e MH |
428 | unregister_probe_event(tp); |
429 | } else | |
430 | list_add_tail(&tp->list, &probe_list); | |
413d37d1 MH |
431 | end: |
432 | mutex_unlock(&probe_lock); | |
433 | return ret; | |
434 | } | |
435 | ||
436 | /* Split symbol and offset. */ | |
2fba0c88 | 437 | static int split_symbol_offset(char *symbol, unsigned long *offset) |
413d37d1 MH |
438 | { |
439 | char *tmp; | |
440 | int ret; | |
441 | ||
442 | if (!offset) | |
443 | return -EINVAL; | |
444 | ||
445 | tmp = strchr(symbol, '+'); | |
413d37d1 MH |
446 | if (tmp) { |
447 | /* skip sign because strict_strtol doesn't accept '+' */ | |
2fba0c88 | 448 | ret = strict_strtoul(tmp + 1, 0, offset); |
413d37d1 MH |
449 | if (ret) |
450 | return ret; | |
413d37d1 MH |
451 | *tmp = '\0'; |
452 | } else | |
453 | *offset = 0; | |
454 | return 0; | |
455 | } | |
456 | ||
457 | #define PARAM_MAX_ARGS 16 | |
458 | #define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long)) | |
459 | ||
405b2651 | 460 | static int parse_probe_vars(char *arg, struct fetch_func *ff, int is_return) |
413d37d1 MH |
461 | { |
462 | int ret = 0; | |
463 | unsigned long param; | |
413d37d1 | 464 | |
2e06ff63 MH |
465 | if (strcmp(arg, "retval") == 0) { |
466 | if (is_return) { | |
413d37d1 MH |
467 | ff->func = fetch_retvalue; |
468 | ff->data = NULL; | |
413d37d1 MH |
469 | } else |
470 | ret = -EINVAL; | |
2e06ff63 MH |
471 | } else if (strncmp(arg, "stack", 5) == 0) { |
472 | if (arg[5] == '\0') { | |
413d37d1 MH |
473 | ff->func = fetch_stack_address; |
474 | ff->data = NULL; | |
2e06ff63 MH |
475 | } else if (isdigit(arg[5])) { |
476 | ret = strict_strtoul(arg + 5, 10, ¶m); | |
413d37d1 MH |
477 | if (ret || param > PARAM_MAX_STACK) |
478 | ret = -EINVAL; | |
479 | else { | |
480 | ff->func = fetch_stack; | |
481 | ff->data = (void *)param; | |
482 | } | |
2e06ff63 MH |
483 | } else |
484 | ret = -EINVAL; | |
2e06ff63 | 485 | } else |
405b2651 | 486 | ret = -EINVAL; |
405b2651 MH |
487 | return ret; |
488 | } | |
489 | ||
ba8665d7 MH |
490 | /* Recursive argument parser */ |
491 | static int __parse_probe_arg(char *arg, struct fetch_func *ff, int is_return) | |
405b2651 MH |
492 | { |
493 | int ret = 0; | |
494 | unsigned long param; | |
495 | long offset; | |
496 | char *tmp; | |
497 | ||
498 | switch (arg[0]) { | |
499 | case '$': | |
500 | ret = parse_probe_vars(arg + 1, ff, is_return); | |
501 | break; | |
502 | case '%': /* named register */ | |
503 | ret = regs_query_register_offset(arg + 1); | |
504 | if (ret >= 0) { | |
505 | ff->func = fetch_register; | |
506 | ff->data = (void *)(unsigned long)ret; | |
507 | ret = 0; | |
508 | } | |
509 | break; | |
413d37d1 MH |
510 | case '@': /* memory or symbol */ |
511 | if (isdigit(arg[1])) { | |
512 | ret = strict_strtoul(arg + 1, 0, ¶m); | |
513 | if (ret) | |
514 | break; | |
515 | ff->func = fetch_memory; | |
516 | ff->data = (void *)param; | |
517 | } else { | |
518 | ret = split_symbol_offset(arg + 1, &offset); | |
519 | if (ret) | |
520 | break; | |
405b2651 | 521 | ff->data = alloc_symbol_cache(arg + 1, offset); |
413d37d1 MH |
522 | if (ff->data) |
523 | ff->func = fetch_symbol; | |
524 | else | |
525 | ret = -EINVAL; | |
526 | } | |
527 | break; | |
528 | case '+': /* indirect memory */ | |
529 | case '-': | |
530 | tmp = strchr(arg, '('); | |
531 | if (!tmp) { | |
532 | ret = -EINVAL; | |
533 | break; | |
534 | } | |
535 | *tmp = '\0'; | |
536 | ret = strict_strtol(arg + 1, 0, &offset); | |
537 | if (ret) | |
538 | break; | |
539 | if (arg[0] == '-') | |
540 | offset = -offset; | |
541 | arg = tmp + 1; | |
542 | tmp = strrchr(arg, ')'); | |
543 | if (tmp) { | |
544 | struct indirect_fetch_data *id; | |
545 | *tmp = '\0'; | |
546 | id = kzalloc(sizeof(struct indirect_fetch_data), | |
547 | GFP_KERNEL); | |
548 | if (!id) | |
549 | return -ENOMEM; | |
550 | id->offset = offset; | |
ba8665d7 | 551 | ret = __parse_probe_arg(arg, &id->orig, is_return); |
413d37d1 MH |
552 | if (ret) |
553 | kfree(id); | |
554 | else { | |
555 | ff->func = fetch_indirect; | |
556 | ff->data = (void *)id; | |
557 | } | |
558 | } else | |
559 | ret = -EINVAL; | |
560 | break; | |
561 | default: | |
562 | /* TODO: support custom handler */ | |
563 | ret = -EINVAL; | |
564 | } | |
565 | return ret; | |
566 | } | |
567 | ||
ba8665d7 MH |
568 | /* String length checking wrapper */ |
569 | static int parse_probe_arg(char *arg, struct fetch_func *ff, int is_return) | |
570 | { | |
571 | if (strlen(arg) > MAX_ARGSTR_LEN) { | |
572 | pr_info("Argument is too long.: %s\n", arg); | |
573 | return -ENOSPC; | |
574 | } | |
575 | return __parse_probe_arg(arg, ff, is_return); | |
576 | } | |
577 | ||
a703d946 MH |
578 | /* Return 1 if name is reserved or already used by another argument */ |
579 | static int conflict_field_name(const char *name, | |
580 | struct probe_arg *args, int narg) | |
581 | { | |
582 | int i; | |
583 | for (i = 0; i < ARRAY_SIZE(reserved_field_names); i++) | |
584 | if (strcmp(reserved_field_names[i], name) == 0) | |
585 | return 1; | |
586 | for (i = 0; i < narg; i++) | |
587 | if (strcmp(args[i].name, name) == 0) | |
588 | return 1; | |
589 | return 0; | |
590 | } | |
591 | ||
413d37d1 MH |
592 | static int create_trace_probe(int argc, char **argv) |
593 | { | |
594 | /* | |
595 | * Argument syntax: | |
f52487e9 MH |
596 | * - Add kprobe: p[:[GRP/]EVENT] KSYM[+OFFS]|KADDR [FETCHARGS] |
597 | * - Add kretprobe: r[:[GRP/]EVENT] KSYM[+0] [FETCHARGS] | |
413d37d1 | 598 | * Fetch args: |
2e06ff63 MH |
599 | * $retval : fetch return value |
600 | * $stack : fetch stack address | |
601 | * $stackN : fetch Nth of stack (N:0-) | |
413d37d1 MH |
602 | * @ADDR : fetch memory at ADDR (ADDR should be in kernel) |
603 | * @SYM[+|-offs] : fetch memory at SYM +|- offs (SYM is a data symbol) | |
604 | * %REG : fetch register REG | |
605 | * Indirect memory fetch: | |
606 | * +|-offs(ARG) : fetch memory at ARG +|- offs address. | |
eca0d916 MH |
607 | * Alias name of args: |
608 | * NAME=FETCHARG : set NAME as alias of FETCHARG. | |
413d37d1 MH |
609 | */ |
610 | struct trace_probe *tp; | |
413d37d1 | 611 | int i, ret = 0; |
a7c312be | 612 | int is_return = 0, is_delete = 0; |
f52487e9 | 613 | char *symbol = NULL, *event = NULL, *arg = NULL, *group = NULL; |
2fba0c88 | 614 | unsigned long offset = 0; |
413d37d1 | 615 | void *addr = NULL; |
4a846b44 | 616 | char buf[MAX_EVENT_NAME_LEN]; |
413d37d1 | 617 | |
a7c312be | 618 | /* argc must be >= 1 */ |
413d37d1 MH |
619 | if (argv[0][0] == 'p') |
620 | is_return = 0; | |
621 | else if (argv[0][0] == 'r') | |
622 | is_return = 1; | |
a7c312be MH |
623 | else if (argv[0][0] == '-') |
624 | is_delete = 1; | |
e63cc239 | 625 | else { |
a7c312be MH |
626 | pr_info("Probe definition must be started with 'p', 'r' or" |
627 | " '-'.\n"); | |
413d37d1 | 628 | return -EINVAL; |
e63cc239 | 629 | } |
413d37d1 MH |
630 | |
631 | if (argv[0][1] == ':') { | |
632 | event = &argv[0][2]; | |
f52487e9 MH |
633 | if (strchr(event, '/')) { |
634 | group = event; | |
635 | event = strchr(group, '/') + 1; | |
636 | event[-1] = '\0'; | |
637 | if (strlen(group) == 0) { | |
a5efd925 | 638 | pr_info("Group name is not specified\n"); |
f52487e9 MH |
639 | return -EINVAL; |
640 | } | |
641 | } | |
413d37d1 | 642 | if (strlen(event) == 0) { |
a5efd925 | 643 | pr_info("Event name is not specified\n"); |
413d37d1 MH |
644 | return -EINVAL; |
645 | } | |
646 | } | |
a7c312be MH |
647 | if (!group) |
648 | group = KPROBE_EVENT_SYSTEM; | |
413d37d1 | 649 | |
a7c312be MH |
650 | if (is_delete) { |
651 | if (!event) { | |
652 | pr_info("Delete command needs an event name.\n"); | |
653 | return -EINVAL; | |
654 | } | |
655 | tp = find_probe_event(event, group); | |
656 | if (!tp) { | |
657 | pr_info("Event %s/%s doesn't exist.\n", group, event); | |
658 | return -ENOENT; | |
659 | } | |
660 | /* delete an event */ | |
661 | unregister_trace_probe(tp); | |
662 | free_trace_probe(tp); | |
663 | return 0; | |
664 | } | |
665 | ||
666 | if (argc < 2) { | |
667 | pr_info("Probe point is not specified.\n"); | |
668 | return -EINVAL; | |
669 | } | |
413d37d1 | 670 | if (isdigit(argv[1][0])) { |
e63cc239 MH |
671 | if (is_return) { |
672 | pr_info("Return probe point must be a symbol.\n"); | |
413d37d1 | 673 | return -EINVAL; |
e63cc239 | 674 | } |
413d37d1 | 675 | /* an address specified */ |
a9bb18f3 | 676 | ret = strict_strtoul(&argv[1][0], 0, (unsigned long *)&addr); |
e63cc239 MH |
677 | if (ret) { |
678 | pr_info("Failed to parse address.\n"); | |
413d37d1 | 679 | return ret; |
e63cc239 | 680 | } |
413d37d1 MH |
681 | } else { |
682 | /* a symbol specified */ | |
683 | symbol = argv[1]; | |
684 | /* TODO: support .init module functions */ | |
685 | ret = split_symbol_offset(symbol, &offset); | |
e63cc239 MH |
686 | if (ret) { |
687 | pr_info("Failed to parse symbol.\n"); | |
413d37d1 | 688 | return ret; |
e63cc239 MH |
689 | } |
690 | if (offset && is_return) { | |
691 | pr_info("Return probe must be used without offset.\n"); | |
413d37d1 | 692 | return -EINVAL; |
e63cc239 | 693 | } |
413d37d1 | 694 | } |
a82378d8 | 695 | argc -= 2; argv += 2; |
413d37d1 MH |
696 | |
697 | /* setup a probe */ | |
4263565d MH |
698 | if (!event) { |
699 | /* Make a new event name */ | |
4263565d | 700 | if (symbol) |
6f3cf440 | 701 | snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_%ld", |
4263565d MH |
702 | is_return ? 'r' : 'p', symbol, offset); |
703 | else | |
6f3cf440 | 704 | snprintf(buf, MAX_EVENT_NAME_LEN, "%c_0x%p", |
4263565d | 705 | is_return ? 'r' : 'p', addr); |
4a846b44 MH |
706 | event = buf; |
707 | } | |
f52487e9 MH |
708 | tp = alloc_trace_probe(group, event, addr, symbol, offset, argc, |
709 | is_return); | |
e63cc239 MH |
710 | if (IS_ERR(tp)) { |
711 | pr_info("Failed to allocate trace_probe.(%d)\n", | |
712 | (int)PTR_ERR(tp)); | |
413d37d1 | 713 | return PTR_ERR(tp); |
e63cc239 | 714 | } |
413d37d1 | 715 | |
413d37d1 | 716 | /* parse arguments */ |
a82378d8 MH |
717 | ret = 0; |
718 | for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) { | |
eca0d916 MH |
719 | /* Parse argument name */ |
720 | arg = strchr(argv[i], '='); | |
721 | if (arg) | |
722 | *arg++ = '\0'; | |
723 | else | |
724 | arg = argv[i]; | |
a703d946 MH |
725 | |
726 | if (conflict_field_name(argv[i], tp->args, i)) { | |
e63cc239 MH |
727 | pr_info("Argument%d name '%s' conflicts with " |
728 | "another field.\n", i, argv[i]); | |
a703d946 MH |
729 | ret = -EINVAL; |
730 | goto error; | |
731 | } | |
732 | ||
eca0d916 | 733 | tp->args[i].name = kstrdup(argv[i], GFP_KERNEL); |
ba8665d7 MH |
734 | if (!tp->args[i].name) { |
735 | pr_info("Failed to allocate argument%d name '%s'.\n", | |
736 | i, argv[i]); | |
737 | ret = -ENOMEM; | |
413d37d1 MH |
738 | goto error; |
739 | } | |
ba8665d7 MH |
740 | |
741 | /* Parse fetch argument */ | |
eca0d916 | 742 | ret = parse_probe_arg(arg, &tp->args[i].fetch, is_return); |
e63cc239 MH |
743 | if (ret) { |
744 | pr_info("Parse error at argument%d. (%d)\n", i, ret); | |
abab9d37 | 745 | kfree(tp->args[i].name); |
413d37d1 | 746 | goto error; |
e63cc239 | 747 | } |
abab9d37 LJ |
748 | |
749 | tp->nr_args++; | |
413d37d1 | 750 | } |
413d37d1 MH |
751 | |
752 | ret = register_trace_probe(tp); | |
753 | if (ret) | |
754 | goto error; | |
755 | return 0; | |
756 | ||
757 | error: | |
758 | free_trace_probe(tp); | |
759 | return ret; | |
760 | } | |
761 | ||
762 | static void cleanup_all_probes(void) | |
763 | { | |
764 | struct trace_probe *tp; | |
765 | ||
766 | mutex_lock(&probe_lock); | |
767 | /* TODO: Use batch unregistration */ | |
768 | while (!list_empty(&probe_list)) { | |
769 | tp = list_entry(probe_list.next, struct trace_probe, list); | |
770 | unregister_trace_probe(tp); | |
771 | free_trace_probe(tp); | |
772 | } | |
773 | mutex_unlock(&probe_lock); | |
774 | } | |
775 | ||
776 | ||
777 | /* Probes listing interfaces */ | |
778 | static void *probes_seq_start(struct seq_file *m, loff_t *pos) | |
779 | { | |
780 | mutex_lock(&probe_lock); | |
781 | return seq_list_start(&probe_list, *pos); | |
782 | } | |
783 | ||
784 | static void *probes_seq_next(struct seq_file *m, void *v, loff_t *pos) | |
785 | { | |
786 | return seq_list_next(v, &probe_list, pos); | |
787 | } | |
788 | ||
789 | static void probes_seq_stop(struct seq_file *m, void *v) | |
790 | { | |
791 | mutex_unlock(&probe_lock); | |
792 | } | |
793 | ||
794 | static int probes_seq_show(struct seq_file *m, void *v) | |
795 | { | |
796 | struct trace_probe *tp = v; | |
797 | int i, ret; | |
798 | char buf[MAX_ARGSTR_LEN + 1]; | |
799 | ||
800 | seq_printf(m, "%c", probe_is_return(tp) ? 'r' : 'p'); | |
3d9b2e1d | 801 | seq_printf(m, ":%s/%s", tp->call.system, tp->call.name); |
413d37d1 | 802 | |
52a11f35 LJ |
803 | if (!tp->symbol) |
804 | seq_printf(m, " 0x%p", tp->rp.kp.addr); | |
805 | else if (tp->rp.kp.offset) | |
4a846b44 | 806 | seq_printf(m, " %s+%u", probe_symbol(tp), tp->rp.kp.offset); |
413d37d1 | 807 | else |
52a11f35 | 808 | seq_printf(m, " %s", probe_symbol(tp)); |
413d37d1 MH |
809 | |
810 | for (i = 0; i < tp->nr_args; i++) { | |
eca0d916 | 811 | ret = probe_arg_string(buf, MAX_ARGSTR_LEN, &tp->args[i].fetch); |
413d37d1 MH |
812 | if (ret < 0) { |
813 | pr_warning("Argument%d decoding error(%d).\n", i, ret); | |
814 | return ret; | |
815 | } | |
eca0d916 | 816 | seq_printf(m, " %s=%s", tp->args[i].name, buf); |
413d37d1 MH |
817 | } |
818 | seq_printf(m, "\n"); | |
819 | return 0; | |
820 | } | |
821 | ||
822 | static const struct seq_operations probes_seq_op = { | |
823 | .start = probes_seq_start, | |
824 | .next = probes_seq_next, | |
825 | .stop = probes_seq_stop, | |
826 | .show = probes_seq_show | |
827 | }; | |
828 | ||
829 | static int probes_open(struct inode *inode, struct file *file) | |
830 | { | |
831 | if ((file->f_mode & FMODE_WRITE) && | |
832 | (file->f_flags & O_TRUNC)) | |
833 | cleanup_all_probes(); | |
834 | ||
835 | return seq_open(file, &probes_seq_op); | |
836 | } | |
837 | ||
838 | static int command_trace_probe(const char *buf) | |
839 | { | |
840 | char **argv; | |
841 | int argc = 0, ret = 0; | |
842 | ||
843 | argv = argv_split(GFP_KERNEL, buf, &argc); | |
844 | if (!argv) | |
845 | return -ENOMEM; | |
846 | ||
847 | if (argc) | |
848 | ret = create_trace_probe(argc, argv); | |
849 | ||
850 | argv_free(argv); | |
851 | return ret; | |
852 | } | |
853 | ||
854 | #define WRITE_BUFSIZE 128 | |
855 | ||
856 | static ssize_t probes_write(struct file *file, const char __user *buffer, | |
857 | size_t count, loff_t *ppos) | |
858 | { | |
859 | char *kbuf, *tmp; | |
860 | int ret; | |
861 | size_t done; | |
862 | size_t size; | |
863 | ||
864 | kbuf = kmalloc(WRITE_BUFSIZE, GFP_KERNEL); | |
865 | if (!kbuf) | |
866 | return -ENOMEM; | |
867 | ||
868 | ret = done = 0; | |
869 | while (done < count) { | |
870 | size = count - done; | |
871 | if (size >= WRITE_BUFSIZE) | |
872 | size = WRITE_BUFSIZE - 1; | |
873 | if (copy_from_user(kbuf, buffer + done, size)) { | |
874 | ret = -EFAULT; | |
875 | goto out; | |
876 | } | |
877 | kbuf[size] = '\0'; | |
878 | tmp = strchr(kbuf, '\n'); | |
879 | if (tmp) { | |
880 | *tmp = '\0'; | |
881 | size = tmp - kbuf + 1; | |
882 | } else if (done + size < count) { | |
883 | pr_warning("Line length is too long: " | |
884 | "Should be less than %d.", WRITE_BUFSIZE); | |
885 | ret = -EINVAL; | |
886 | goto out; | |
887 | } | |
888 | done += size; | |
889 | /* Remove comments */ | |
890 | tmp = strchr(kbuf, '#'); | |
891 | if (tmp) | |
892 | *tmp = '\0'; | |
893 | ||
894 | ret = command_trace_probe(kbuf); | |
895 | if (ret) | |
896 | goto out; | |
897 | } | |
898 | ret = done; | |
899 | out: | |
900 | kfree(kbuf); | |
901 | return ret; | |
902 | } | |
903 | ||
904 | static const struct file_operations kprobe_events_ops = { | |
905 | .owner = THIS_MODULE, | |
906 | .open = probes_open, | |
907 | .read = seq_read, | |
908 | .llseek = seq_lseek, | |
909 | .release = seq_release, | |
910 | .write = probes_write, | |
911 | }; | |
912 | ||
cd7e7bd5 MH |
913 | /* Probes profiling interfaces */ |
914 | static int probes_profile_seq_show(struct seq_file *m, void *v) | |
915 | { | |
916 | struct trace_probe *tp = v; | |
917 | ||
918 | seq_printf(m, " %-44s %15lu %15lu\n", tp->call.name, tp->nhit, | |
4a846b44 | 919 | tp->rp.kp.nmissed); |
cd7e7bd5 MH |
920 | |
921 | return 0; | |
922 | } | |
923 | ||
924 | static const struct seq_operations profile_seq_op = { | |
925 | .start = probes_seq_start, | |
926 | .next = probes_seq_next, | |
927 | .stop = probes_seq_stop, | |
928 | .show = probes_profile_seq_show | |
929 | }; | |
930 | ||
931 | static int profile_open(struct inode *inode, struct file *file) | |
932 | { | |
933 | return seq_open(file, &profile_seq_op); | |
934 | } | |
935 | ||
936 | static const struct file_operations kprobe_profile_ops = { | |
937 | .owner = THIS_MODULE, | |
938 | .open = profile_open, | |
939 | .read = seq_read, | |
940 | .llseek = seq_lseek, | |
941 | .release = seq_release, | |
942 | }; | |
943 | ||
413d37d1 | 944 | /* Kprobe handler */ |
1e12a4a7 | 945 | static __kprobes void kprobe_trace_func(struct kprobe *kp, struct pt_regs *regs) |
413d37d1 | 946 | { |
4a846b44 | 947 | struct trace_probe *tp = container_of(kp, struct trace_probe, rp.kp); |
413d37d1 MH |
948 | struct kprobe_trace_entry *entry; |
949 | struct ring_buffer_event *event; | |
8f8ffe24 | 950 | struct ring_buffer *buffer; |
413d37d1 MH |
951 | int size, i, pc; |
952 | unsigned long irq_flags; | |
4263565d | 953 | struct ftrace_event_call *call = &tp->call; |
413d37d1 | 954 | |
cd7e7bd5 MH |
955 | tp->nhit++; |
956 | ||
413d37d1 MH |
957 | local_save_flags(irq_flags); |
958 | pc = preempt_count(); | |
959 | ||
960 | size = SIZEOF_KPROBE_TRACE_ENTRY(tp->nr_args); | |
961 | ||
8f8ffe24 | 962 | event = trace_current_buffer_lock_reserve(&buffer, call->id, size, |
413d37d1 MH |
963 | irq_flags, pc); |
964 | if (!event) | |
1e12a4a7 | 965 | return; |
413d37d1 MH |
966 | |
967 | entry = ring_buffer_event_data(event); | |
968 | entry->nargs = tp->nr_args; | |
969 | entry->ip = (unsigned long)kp->addr; | |
970 | for (i = 0; i < tp->nr_args; i++) | |
eca0d916 | 971 | entry->args[i] = call_fetch(&tp->args[i].fetch, regs); |
413d37d1 | 972 | |
8f8ffe24 FW |
973 | if (!filter_current_check_discard(buffer, call, entry, event)) |
974 | trace_nowake_buffer_unlock_commit(buffer, event, irq_flags, pc); | |
413d37d1 MH |
975 | } |
976 | ||
977 | /* Kretprobe handler */ | |
1e12a4a7 | 978 | static __kprobes void kretprobe_trace_func(struct kretprobe_instance *ri, |
413d37d1 MH |
979 | struct pt_regs *regs) |
980 | { | |
981 | struct trace_probe *tp = container_of(ri->rp, struct trace_probe, rp); | |
982 | struct kretprobe_trace_entry *entry; | |
983 | struct ring_buffer_event *event; | |
8f8ffe24 | 984 | struct ring_buffer *buffer; |
413d37d1 MH |
985 | int size, i, pc; |
986 | unsigned long irq_flags; | |
4263565d | 987 | struct ftrace_event_call *call = &tp->call; |
413d37d1 MH |
988 | |
989 | local_save_flags(irq_flags); | |
990 | pc = preempt_count(); | |
991 | ||
992 | size = SIZEOF_KRETPROBE_TRACE_ENTRY(tp->nr_args); | |
993 | ||
8f8ffe24 | 994 | event = trace_current_buffer_lock_reserve(&buffer, call->id, size, |
413d37d1 MH |
995 | irq_flags, pc); |
996 | if (!event) | |
1e12a4a7 | 997 | return; |
413d37d1 MH |
998 | |
999 | entry = ring_buffer_event_data(event); | |
1000 | entry->nargs = tp->nr_args; | |
4a846b44 | 1001 | entry->func = (unsigned long)tp->rp.kp.addr; |
413d37d1 MH |
1002 | entry->ret_ip = (unsigned long)ri->ret_addr; |
1003 | for (i = 0; i < tp->nr_args; i++) | |
eca0d916 | 1004 | entry->args[i] = call_fetch(&tp->args[i].fetch, regs); |
413d37d1 | 1005 | |
8f8ffe24 FW |
1006 | if (!filter_current_check_discard(buffer, call, entry, event)) |
1007 | trace_nowake_buffer_unlock_commit(buffer, event, irq_flags, pc); | |
413d37d1 MH |
1008 | } |
1009 | ||
1010 | /* Event entry printers */ | |
1011 | enum print_line_t | |
1012 | print_kprobe_event(struct trace_iterator *iter, int flags) | |
1013 | { | |
1014 | struct kprobe_trace_entry *field; | |
1015 | struct trace_seq *s = &iter->seq; | |
eca0d916 MH |
1016 | struct trace_event *event; |
1017 | struct trace_probe *tp; | |
413d37d1 MH |
1018 | int i; |
1019 | ||
ff50d991 | 1020 | field = (struct kprobe_trace_entry *)iter->ent; |
eca0d916 MH |
1021 | event = ftrace_find_event(field->ent.type); |
1022 | tp = container_of(event, struct trace_probe, event); | |
413d37d1 | 1023 | |
6e9f23d1 MH |
1024 | if (!trace_seq_printf(s, "%s: (", tp->call.name)) |
1025 | goto partial; | |
1026 | ||
413d37d1 MH |
1027 | if (!seq_print_ip_sym(s, field->ip, flags | TRACE_ITER_SYM_OFFSET)) |
1028 | goto partial; | |
1029 | ||
6e9f23d1 | 1030 | if (!trace_seq_puts(s, ")")) |
413d37d1 MH |
1031 | goto partial; |
1032 | ||
1033 | for (i = 0; i < field->nargs; i++) | |
eca0d916 MH |
1034 | if (!trace_seq_printf(s, " %s=%lx", |
1035 | tp->args[i].name, field->args[i])) | |
413d37d1 MH |
1036 | goto partial; |
1037 | ||
1038 | if (!trace_seq_puts(s, "\n")) | |
1039 | goto partial; | |
1040 | ||
1041 | return TRACE_TYPE_HANDLED; | |
1042 | partial: | |
1043 | return TRACE_TYPE_PARTIAL_LINE; | |
1044 | } | |
1045 | ||
1046 | enum print_line_t | |
1047 | print_kretprobe_event(struct trace_iterator *iter, int flags) | |
1048 | { | |
1049 | struct kretprobe_trace_entry *field; | |
1050 | struct trace_seq *s = &iter->seq; | |
eca0d916 MH |
1051 | struct trace_event *event; |
1052 | struct trace_probe *tp; | |
413d37d1 MH |
1053 | int i; |
1054 | ||
ff50d991 | 1055 | field = (struct kretprobe_trace_entry *)iter->ent; |
eca0d916 MH |
1056 | event = ftrace_find_event(field->ent.type); |
1057 | tp = container_of(event, struct trace_probe, event); | |
413d37d1 | 1058 | |
6e9f23d1 MH |
1059 | if (!trace_seq_printf(s, "%s: (", tp->call.name)) |
1060 | goto partial; | |
1061 | ||
413d37d1 MH |
1062 | if (!seq_print_ip_sym(s, field->ret_ip, flags | TRACE_ITER_SYM_OFFSET)) |
1063 | goto partial; | |
1064 | ||
1065 | if (!trace_seq_puts(s, " <- ")) | |
1066 | goto partial; | |
1067 | ||
1068 | if (!seq_print_ip_sym(s, field->func, flags & ~TRACE_ITER_SYM_OFFSET)) | |
1069 | goto partial; | |
1070 | ||
6e9f23d1 | 1071 | if (!trace_seq_puts(s, ")")) |
413d37d1 MH |
1072 | goto partial; |
1073 | ||
1074 | for (i = 0; i < field->nargs; i++) | |
eca0d916 MH |
1075 | if (!trace_seq_printf(s, " %s=%lx", |
1076 | tp->args[i].name, field->args[i])) | |
413d37d1 MH |
1077 | goto partial; |
1078 | ||
1079 | if (!trace_seq_puts(s, "\n")) | |
1080 | goto partial; | |
1081 | ||
1082 | return TRACE_TYPE_HANDLED; | |
1083 | partial: | |
1084 | return TRACE_TYPE_PARTIAL_LINE; | |
1085 | } | |
1086 | ||
413d37d1 MH |
1087 | static int probe_event_enable(struct ftrace_event_call *call) |
1088 | { | |
1089 | struct trace_probe *tp = (struct trace_probe *)call->data; | |
1090 | ||
50d78056 MH |
1091 | tp->flags |= TP_FLAG_TRACE; |
1092 | if (probe_is_return(tp)) | |
413d37d1 | 1093 | return enable_kretprobe(&tp->rp); |
50d78056 | 1094 | else |
4a846b44 | 1095 | return enable_kprobe(&tp->rp.kp); |
413d37d1 MH |
1096 | } |
1097 | ||
1098 | static void probe_event_disable(struct ftrace_event_call *call) | |
1099 | { | |
1100 | struct trace_probe *tp = (struct trace_probe *)call->data; | |
1101 | ||
50d78056 MH |
1102 | tp->flags &= ~TP_FLAG_TRACE; |
1103 | if (!(tp->flags & (TP_FLAG_TRACE | TP_FLAG_PROFILE))) { | |
1104 | if (probe_is_return(tp)) | |
1105 | disable_kretprobe(&tp->rp); | |
1106 | else | |
1107 | disable_kprobe(&tp->rp.kp); | |
1108 | } | |
413d37d1 MH |
1109 | } |
1110 | ||
1111 | static int probe_event_raw_init(struct ftrace_event_call *event_call) | |
1112 | { | |
1113 | INIT_LIST_HEAD(&event_call->fields); | |
8f8ffe24 | 1114 | |
413d37d1 MH |
1115 | return 0; |
1116 | } | |
1117 | ||
1118 | #undef DEFINE_FIELD | |
1119 | #define DEFINE_FIELD(type, item, name, is_signed) \ | |
1120 | do { \ | |
1121 | ret = trace_define_field(event_call, #type, name, \ | |
1122 | offsetof(typeof(field), item), \ | |
1123 | sizeof(field.item), is_signed, \ | |
1124 | FILTER_OTHER); \ | |
1125 | if (ret) \ | |
1126 | return ret; \ | |
1127 | } while (0) | |
1128 | ||
1129 | static int kprobe_event_define_fields(struct ftrace_event_call *event_call) | |
1130 | { | |
1131 | int ret, i; | |
1132 | struct kprobe_trace_entry field; | |
413d37d1 MH |
1133 | struct trace_probe *tp = (struct trace_probe *)event_call->data; |
1134 | ||
a703d946 MH |
1135 | DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0); |
1136 | DEFINE_FIELD(int, nargs, FIELD_STRING_NARGS, 1); | |
eca0d916 MH |
1137 | /* Set argument names as fields */ |
1138 | for (i = 0; i < tp->nr_args; i++) | |
1139 | DEFINE_FIELD(unsigned long, args[i], tp->args[i].name, 0); | |
413d37d1 MH |
1140 | return 0; |
1141 | } | |
1142 | ||
1143 | static int kretprobe_event_define_fields(struct ftrace_event_call *event_call) | |
1144 | { | |
1145 | int ret, i; | |
1146 | struct kretprobe_trace_entry field; | |
413d37d1 MH |
1147 | struct trace_probe *tp = (struct trace_probe *)event_call->data; |
1148 | ||
a703d946 MH |
1149 | DEFINE_FIELD(unsigned long, func, FIELD_STRING_FUNC, 0); |
1150 | DEFINE_FIELD(unsigned long, ret_ip, FIELD_STRING_RETIP, 0); | |
1151 | DEFINE_FIELD(int, nargs, FIELD_STRING_NARGS, 1); | |
eca0d916 MH |
1152 | /* Set argument names as fields */ |
1153 | for (i = 0; i < tp->nr_args; i++) | |
1154 | DEFINE_FIELD(unsigned long, args[i], tp->args[i].name, 0); | |
413d37d1 MH |
1155 | return 0; |
1156 | } | |
1157 | ||
a342a028 LJ |
1158 | static int __set_print_fmt(struct trace_probe *tp, char *buf, int len) |
1159 | { | |
1160 | int i; | |
1161 | int pos = 0; | |
1162 | ||
1163 | const char *fmt, *arg; | |
1164 | ||
1165 | if (!probe_is_return(tp)) { | |
1166 | fmt = "(%lx)"; | |
1167 | arg = "REC->" FIELD_STRING_IP; | |
1168 | } else { | |
1169 | fmt = "(%lx <- %lx)"; | |
1170 | arg = "REC->" FIELD_STRING_FUNC ", REC->" FIELD_STRING_RETIP; | |
1171 | } | |
1172 | ||
1173 | /* When len=0, we just calculate the needed length */ | |
1174 | #define LEN_OR_ZERO (len ? len - pos : 0) | |
1175 | ||
1176 | pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", fmt); | |
1177 | ||
1178 | for (i = 0; i < tp->nr_args; i++) { | |
1179 | pos += snprintf(buf + pos, LEN_OR_ZERO, " %s=%%lx", | |
1180 | tp->args[i].name); | |
1181 | } | |
1182 | ||
1183 | pos += snprintf(buf + pos, LEN_OR_ZERO, "\", %s", arg); | |
1184 | ||
1185 | for (i = 0; i < tp->nr_args; i++) { | |
1186 | pos += snprintf(buf + pos, LEN_OR_ZERO, ", REC->%s", | |
1187 | tp->args[i].name); | |
1188 | } | |
1189 | ||
1190 | #undef LEN_OR_ZERO | |
1191 | ||
1192 | /* return the length of print_fmt */ | |
1193 | return pos; | |
1194 | } | |
1195 | ||
1196 | static int set_print_fmt(struct trace_probe *tp) | |
1197 | { | |
1198 | int len; | |
1199 | char *print_fmt; | |
1200 | ||
1201 | /* First: called with 0 length to calculate the needed length */ | |
1202 | len = __set_print_fmt(tp, NULL, 0); | |
1203 | print_fmt = kmalloc(len + 1, GFP_KERNEL); | |
1204 | if (!print_fmt) | |
1205 | return -ENOMEM; | |
1206 | ||
1207 | /* Second: actually write the @print_fmt */ | |
1208 | __set_print_fmt(tp, print_fmt, len + 1); | |
1209 | tp->call.print_fmt = print_fmt; | |
1210 | ||
1211 | return 0; | |
1212 | } | |
1213 | ||
07b139c8 | 1214 | #ifdef CONFIG_PERF_EVENTS |
e08d1c65 MH |
1215 | |
1216 | /* Kprobe profile handler */ | |
97d5a220 | 1217 | static __kprobes void kprobe_perf_func(struct kprobe *kp, |
e08d1c65 MH |
1218 | struct pt_regs *regs) |
1219 | { | |
1220 | struct trace_probe *tp = container_of(kp, struct trace_probe, rp.kp); | |
1221 | struct ftrace_event_call *call = &tp->call; | |
1222 | struct kprobe_trace_entry *entry; | |
430ad5a6 | 1223 | int size, __size, i; |
e08d1c65 | 1224 | unsigned long irq_flags; |
4ed7c92d | 1225 | int rctx; |
e08d1c65 | 1226 | |
74ebb63e MH |
1227 | __size = SIZEOF_KPROBE_TRACE_ENTRY(tp->nr_args); |
1228 | size = ALIGN(__size + sizeof(u32), sizeof(u64)); | |
1229 | size -= sizeof(u32); | |
97d5a220 | 1230 | if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, |
a1a138d0 | 1231 | "profile buffer not large enough")) |
1e12a4a7 | 1232 | return; |
ce71b9df | 1233 | |
97d5a220 | 1234 | entry = perf_trace_buf_prepare(size, call->id, &rctx, &irq_flags); |
430ad5a6 | 1235 | if (!entry) |
1e12a4a7 | 1236 | return; |
a1a138d0 | 1237 | |
a1a138d0 MH |
1238 | entry->nargs = tp->nr_args; |
1239 | entry->ip = (unsigned long)kp->addr; | |
1240 | for (i = 0; i < tp->nr_args; i++) | |
1241 | entry->args[i] = call_fetch(&tp->args[i].fetch, regs); | |
444a2a3b | 1242 | |
97d5a220 | 1243 | perf_trace_buf_submit(entry, size, rctx, entry->ip, 1, irq_flags, regs); |
e08d1c65 MH |
1244 | } |
1245 | ||
1246 | /* Kretprobe profile handler */ | |
97d5a220 | 1247 | static __kprobes void kretprobe_perf_func(struct kretprobe_instance *ri, |
e08d1c65 MH |
1248 | struct pt_regs *regs) |
1249 | { | |
1250 | struct trace_probe *tp = container_of(ri->rp, struct trace_probe, rp); | |
1251 | struct ftrace_event_call *call = &tp->call; | |
1252 | struct kretprobe_trace_entry *entry; | |
430ad5a6 | 1253 | int size, __size, i; |
e08d1c65 | 1254 | unsigned long irq_flags; |
4ed7c92d | 1255 | int rctx; |
e08d1c65 | 1256 | |
74ebb63e MH |
1257 | __size = SIZEOF_KRETPROBE_TRACE_ENTRY(tp->nr_args); |
1258 | size = ALIGN(__size + sizeof(u32), sizeof(u64)); | |
1259 | size -= sizeof(u32); | |
97d5a220 | 1260 | if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, |
a1a138d0 | 1261 | "profile buffer not large enough")) |
1e12a4a7 | 1262 | return; |
444a2a3b | 1263 | |
97d5a220 | 1264 | entry = perf_trace_buf_prepare(size, call->id, &rctx, &irq_flags); |
430ad5a6 | 1265 | if (!entry) |
1e12a4a7 | 1266 | return; |
e08d1c65 | 1267 | |
a1a138d0 MH |
1268 | entry->nargs = tp->nr_args; |
1269 | entry->func = (unsigned long)tp->rp.kp.addr; | |
1270 | entry->ret_ip = (unsigned long)ri->ret_addr; | |
1271 | for (i = 0; i < tp->nr_args; i++) | |
1272 | entry->args[i] = call_fetch(&tp->args[i].fetch, regs); | |
444a2a3b | 1273 | |
97d5a220 | 1274 | perf_trace_buf_submit(entry, size, rctx, entry->ret_ip, 1, |
c530665c | 1275 | irq_flags, regs); |
e08d1c65 MH |
1276 | } |
1277 | ||
97d5a220 | 1278 | static int probe_perf_enable(struct ftrace_event_call *call) |
e08d1c65 MH |
1279 | { |
1280 | struct trace_probe *tp = (struct trace_probe *)call->data; | |
1281 | ||
50d78056 | 1282 | tp->flags |= TP_FLAG_PROFILE; |
d7a4b414 | 1283 | |
50d78056 | 1284 | if (probe_is_return(tp)) |
e08d1c65 | 1285 | return enable_kretprobe(&tp->rp); |
50d78056 | 1286 | else |
e08d1c65 | 1287 | return enable_kprobe(&tp->rp.kp); |
e08d1c65 MH |
1288 | } |
1289 | ||
97d5a220 | 1290 | static void probe_perf_disable(struct ftrace_event_call *call) |
e08d1c65 | 1291 | { |
50d78056 MH |
1292 | struct trace_probe *tp = (struct trace_probe *)call->data; |
1293 | ||
d7a4b414 | 1294 | tp->flags &= ~TP_FLAG_PROFILE; |
50d78056 | 1295 | |
d7a4b414 | 1296 | if (!(tp->flags & TP_FLAG_TRACE)) { |
50d78056 MH |
1297 | if (probe_is_return(tp)) |
1298 | disable_kretprobe(&tp->rp); | |
1299 | else | |
1300 | disable_kprobe(&tp->rp.kp); | |
1301 | } | |
e08d1c65 | 1302 | } |
07b139c8 | 1303 | #endif /* CONFIG_PERF_EVENTS */ |
50d78056 MH |
1304 | |
1305 | ||
1306 | static __kprobes | |
1307 | int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs) | |
1308 | { | |
1309 | struct trace_probe *tp = container_of(kp, struct trace_probe, rp.kp); | |
e08d1c65 | 1310 | |
50d78056 MH |
1311 | if (tp->flags & TP_FLAG_TRACE) |
1312 | kprobe_trace_func(kp, regs); | |
07b139c8 | 1313 | #ifdef CONFIG_PERF_EVENTS |
50d78056 | 1314 | if (tp->flags & TP_FLAG_PROFILE) |
97d5a220 | 1315 | kprobe_perf_func(kp, regs); |
07b139c8 | 1316 | #endif |
50d78056 MH |
1317 | return 0; /* We don't tweek kernel, so just return 0 */ |
1318 | } | |
1319 | ||
1320 | static __kprobes | |
1321 | int kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs) | |
1322 | { | |
1323 | struct trace_probe *tp = container_of(ri->rp, struct trace_probe, rp); | |
1324 | ||
1325 | if (tp->flags & TP_FLAG_TRACE) | |
1326 | kretprobe_trace_func(ri, regs); | |
07b139c8 | 1327 | #ifdef CONFIG_PERF_EVENTS |
50d78056 | 1328 | if (tp->flags & TP_FLAG_PROFILE) |
97d5a220 | 1329 | kretprobe_perf_func(ri, regs); |
07b139c8 | 1330 | #endif |
50d78056 MH |
1331 | return 0; /* We don't tweek kernel, so just return 0 */ |
1332 | } | |
e08d1c65 | 1333 | |
413d37d1 MH |
1334 | static int register_probe_event(struct trace_probe *tp) |
1335 | { | |
1336 | struct ftrace_event_call *call = &tp->call; | |
1337 | int ret; | |
1338 | ||
1339 | /* Initialize ftrace_event_call */ | |
413d37d1 | 1340 | if (probe_is_return(tp)) { |
ff50d991 | 1341 | tp->event.trace = print_kretprobe_event; |
413d37d1 | 1342 | call->raw_init = probe_event_raw_init; |
413d37d1 MH |
1343 | call->define_fields = kretprobe_event_define_fields; |
1344 | } else { | |
ff50d991 | 1345 | tp->event.trace = print_kprobe_event; |
413d37d1 | 1346 | call->raw_init = probe_event_raw_init; |
413d37d1 MH |
1347 | call->define_fields = kprobe_event_define_fields; |
1348 | } | |
a342a028 LJ |
1349 | if (set_print_fmt(tp) < 0) |
1350 | return -ENOMEM; | |
ff50d991 MH |
1351 | call->event = &tp->event; |
1352 | call->id = register_ftrace_event(&tp->event); | |
a342a028 LJ |
1353 | if (!call->id) { |
1354 | kfree(call->print_fmt); | |
ff50d991 | 1355 | return -ENODEV; |
a342a028 | 1356 | } |
5a0d9050 | 1357 | call->enabled = 0; |
413d37d1 MH |
1358 | call->regfunc = probe_event_enable; |
1359 | call->unregfunc = probe_event_disable; | |
e08d1c65 | 1360 | |
07b139c8 | 1361 | #ifdef CONFIG_PERF_EVENTS |
97d5a220 FW |
1362 | call->perf_event_enable = probe_perf_enable; |
1363 | call->perf_event_disable = probe_perf_disable; | |
e08d1c65 | 1364 | #endif |
413d37d1 MH |
1365 | call->data = tp; |
1366 | ret = trace_add_event_call(call); | |
ff50d991 | 1367 | if (ret) { |
413d37d1 | 1368 | pr_info("Failed to register kprobe event: %s\n", call->name); |
a342a028 | 1369 | kfree(call->print_fmt); |
ff50d991 MH |
1370 | unregister_ftrace_event(&tp->event); |
1371 | } | |
413d37d1 MH |
1372 | return ret; |
1373 | } | |
1374 | ||
1375 | static void unregister_probe_event(struct trace_probe *tp) | |
1376 | { | |
ff50d991 | 1377 | /* tp->event is unregistered in trace_remove_event_call() */ |
413d37d1 | 1378 | trace_remove_event_call(&tp->call); |
a342a028 | 1379 | kfree(tp->call.print_fmt); |
413d37d1 MH |
1380 | } |
1381 | ||
1382 | /* Make a debugfs interface for controling probe points */ | |
1383 | static __init int init_kprobe_trace(void) | |
1384 | { | |
1385 | struct dentry *d_tracer; | |
1386 | struct dentry *entry; | |
413d37d1 MH |
1387 | |
1388 | d_tracer = tracing_init_dentry(); | |
1389 | if (!d_tracer) | |
1390 | return 0; | |
1391 | ||
1392 | entry = debugfs_create_file("kprobe_events", 0644, d_tracer, | |
1393 | NULL, &kprobe_events_ops); | |
1394 | ||
cd7e7bd5 | 1395 | /* Event list interface */ |
413d37d1 MH |
1396 | if (!entry) |
1397 | pr_warning("Could not create debugfs " | |
1398 | "'kprobe_events' entry\n"); | |
cd7e7bd5 MH |
1399 | |
1400 | /* Profile interface */ | |
1401 | entry = debugfs_create_file("kprobe_profile", 0444, d_tracer, | |
1402 | NULL, &kprobe_profile_ops); | |
1403 | ||
1404 | if (!entry) | |
1405 | pr_warning("Could not create debugfs " | |
1406 | "'kprobe_profile' entry\n"); | |
413d37d1 MH |
1407 | return 0; |
1408 | } | |
1409 | fs_initcall(init_kprobe_trace); | |
1410 | ||
1411 | ||
1412 | #ifdef CONFIG_FTRACE_STARTUP_TEST | |
1413 | ||
1414 | static int kprobe_trace_selftest_target(int a1, int a2, int a3, | |
1415 | int a4, int a5, int a6) | |
1416 | { | |
1417 | return a1 + a2 + a3 + a4 + a5 + a6; | |
1418 | } | |
1419 | ||
1420 | static __init int kprobe_trace_self_tests_init(void) | |
1421 | { | |
231e36f4 | 1422 | int ret, warn = 0; |
413d37d1 | 1423 | int (*target)(int, int, int, int, int, int); |
231e36f4 | 1424 | struct trace_probe *tp; |
413d37d1 MH |
1425 | |
1426 | target = kprobe_trace_selftest_target; | |
1427 | ||
1428 | pr_info("Testing kprobe tracing: "); | |
1429 | ||
1430 | ret = command_trace_probe("p:testprobe kprobe_trace_selftest_target " | |
231e36f4 MH |
1431 | "$stack $stack0 +0($stack)"); |
1432 | if (WARN_ON_ONCE(ret)) { | |
1433 | pr_warning("error on probing function entry.\n"); | |
1434 | warn++; | |
1435 | } else { | |
1436 | /* Enable trace point */ | |
1437 | tp = find_probe_event("testprobe", KPROBE_EVENT_SYSTEM); | |
1438 | if (WARN_ON_ONCE(tp == NULL)) { | |
1439 | pr_warning("error on getting new probe.\n"); | |
1440 | warn++; | |
1441 | } else | |
1442 | probe_event_enable(&tp->call); | |
1443 | } | |
413d37d1 MH |
1444 | |
1445 | ret = command_trace_probe("r:testprobe2 kprobe_trace_selftest_target " | |
f397af06 | 1446 | "$retval"); |
231e36f4 MH |
1447 | if (WARN_ON_ONCE(ret)) { |
1448 | pr_warning("error on probing function return.\n"); | |
1449 | warn++; | |
1450 | } else { | |
1451 | /* Enable trace point */ | |
1452 | tp = find_probe_event("testprobe2", KPROBE_EVENT_SYSTEM); | |
1453 | if (WARN_ON_ONCE(tp == NULL)) { | |
1454 | pr_warning("error on getting new probe.\n"); | |
1455 | warn++; | |
1456 | } else | |
1457 | probe_event_enable(&tp->call); | |
1458 | } | |
1459 | ||
1460 | if (warn) | |
1461 | goto end; | |
413d37d1 MH |
1462 | |
1463 | ret = target(1, 2, 3, 4, 5, 6); | |
1464 | ||
231e36f4 MH |
1465 | ret = command_trace_probe("-:testprobe"); |
1466 | if (WARN_ON_ONCE(ret)) { | |
1467 | pr_warning("error on deleting a probe.\n"); | |
1468 | warn++; | |
1469 | } | |
1470 | ||
1471 | ret = command_trace_probe("-:testprobe2"); | |
1472 | if (WARN_ON_ONCE(ret)) { | |
1473 | pr_warning("error on deleting a probe.\n"); | |
1474 | warn++; | |
1475 | } | |
413d37d1 | 1476 | |
231e36f4 MH |
1477 | end: |
1478 | cleanup_all_probes(); | |
1479 | if (warn) | |
1480 | pr_cont("NG: Some tests are failed. Please check them.\n"); | |
1481 | else | |
1482 | pr_cont("OK\n"); | |
413d37d1 MH |
1483 | return 0; |
1484 | } | |
1485 | ||
1486 | late_initcall(kprobe_trace_self_tests_init); | |
1487 | ||
1488 | #endif |