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 | ||
94 | static __kprobes unsigned long fetch_argument(struct pt_regs *regs, void *num) | |
95 | { | |
96 | return regs_get_argument_nth(regs, (unsigned int)((unsigned long)num)); | |
97 | } | |
98 | ||
99 | static __kprobes unsigned long fetch_retvalue(struct pt_regs *regs, | |
100 | void *dummy) | |
101 | { | |
102 | return regs_return_value(regs); | |
103 | } | |
104 | ||
413d37d1 MH |
105 | static __kprobes unsigned long fetch_stack_address(struct pt_regs *regs, |
106 | void *dummy) | |
107 | { | |
108 | return kernel_stack_pointer(regs); | |
109 | } | |
110 | ||
111 | /* Memory fetching by symbol */ | |
112 | struct symbol_cache { | |
113 | char *symbol; | |
114 | long offset; | |
115 | unsigned long addr; | |
116 | }; | |
117 | ||
118 | static unsigned long update_symbol_cache(struct symbol_cache *sc) | |
119 | { | |
120 | sc->addr = (unsigned long)kallsyms_lookup_name(sc->symbol); | |
121 | if (sc->addr) | |
122 | sc->addr += sc->offset; | |
123 | return sc->addr; | |
124 | } | |
125 | ||
126 | static void free_symbol_cache(struct symbol_cache *sc) | |
127 | { | |
128 | kfree(sc->symbol); | |
129 | kfree(sc); | |
130 | } | |
131 | ||
132 | static struct symbol_cache *alloc_symbol_cache(const char *sym, long offset) | |
133 | { | |
134 | struct symbol_cache *sc; | |
135 | ||
136 | if (!sym || strlen(sym) == 0) | |
137 | return NULL; | |
138 | sc = kzalloc(sizeof(struct symbol_cache), GFP_KERNEL); | |
139 | if (!sc) | |
140 | return NULL; | |
141 | ||
142 | sc->symbol = kstrdup(sym, GFP_KERNEL); | |
143 | if (!sc->symbol) { | |
144 | kfree(sc); | |
145 | return NULL; | |
146 | } | |
147 | sc->offset = offset; | |
148 | ||
149 | update_symbol_cache(sc); | |
150 | return sc; | |
151 | } | |
152 | ||
153 | static __kprobes unsigned long fetch_symbol(struct pt_regs *regs, void *data) | |
154 | { | |
155 | struct symbol_cache *sc = data; | |
156 | ||
157 | if (sc->addr) | |
158 | return fetch_memory(regs, (void *)sc->addr); | |
159 | else | |
160 | return 0; | |
161 | } | |
162 | ||
163 | /* Special indirect memory access interface */ | |
164 | struct indirect_fetch_data { | |
165 | struct fetch_func orig; | |
166 | long offset; | |
167 | }; | |
168 | ||
169 | static __kprobes unsigned long fetch_indirect(struct pt_regs *regs, void *data) | |
170 | { | |
171 | struct indirect_fetch_data *ind = data; | |
172 | unsigned long addr; | |
173 | ||
174 | addr = call_fetch(&ind->orig, regs); | |
175 | if (addr) { | |
176 | addr += ind->offset; | |
177 | return fetch_memory(regs, (void *)addr); | |
178 | } else | |
179 | return 0; | |
180 | } | |
181 | ||
182 | static __kprobes void free_indirect_fetch_data(struct indirect_fetch_data *data) | |
183 | { | |
184 | if (data->orig.func == fetch_indirect) | |
185 | free_indirect_fetch_data(data->orig.data); | |
186 | else if (data->orig.func == fetch_symbol) | |
187 | free_symbol_cache(data->orig.data); | |
188 | kfree(data); | |
189 | } | |
190 | ||
191 | /** | |
77b44d1b | 192 | * Kprobe event core functions |
413d37d1 MH |
193 | */ |
194 | ||
eca0d916 MH |
195 | struct probe_arg { |
196 | struct fetch_func fetch; | |
197 | const char *name; | |
198 | }; | |
199 | ||
50d78056 MH |
200 | /* Flags for trace_probe */ |
201 | #define TP_FLAG_TRACE 1 | |
202 | #define TP_FLAG_PROFILE 2 | |
203 | ||
413d37d1 MH |
204 | struct trace_probe { |
205 | struct list_head list; | |
4a846b44 | 206 | struct kretprobe rp; /* Use rp.kp for kprobe use */ |
cd7e7bd5 | 207 | unsigned long nhit; |
50d78056 | 208 | unsigned int flags; /* For TP_FLAG_* */ |
413d37d1 | 209 | const char *symbol; /* symbol name */ |
413d37d1 | 210 | struct ftrace_event_call call; |
ff50d991 | 211 | struct trace_event event; |
a82378d8 | 212 | unsigned int nr_args; |
eca0d916 | 213 | struct probe_arg args[]; |
413d37d1 MH |
214 | }; |
215 | ||
a82378d8 MH |
216 | #define SIZEOF_TRACE_PROBE(n) \ |
217 | (offsetof(struct trace_probe, args) + \ | |
eca0d916 | 218 | (sizeof(struct probe_arg) * (n))) |
a82378d8 | 219 | |
413d37d1 MH |
220 | static __kprobes int probe_is_return(struct trace_probe *tp) |
221 | { | |
4a846b44 | 222 | return tp->rp.handler != NULL; |
413d37d1 MH |
223 | } |
224 | ||
225 | static __kprobes const char *probe_symbol(struct trace_probe *tp) | |
226 | { | |
227 | return tp->symbol ? tp->symbol : "unknown"; | |
228 | } | |
229 | ||
30a7e073 | 230 | static int probe_arg_string(char *buf, size_t n, struct fetch_func *ff) |
413d37d1 MH |
231 | { |
232 | int ret = -EINVAL; | |
233 | ||
234 | if (ff->func == fetch_argument) | |
2e06ff63 | 235 | ret = snprintf(buf, n, "$arg%lu", (unsigned long)ff->data); |
413d37d1 MH |
236 | else if (ff->func == fetch_register) { |
237 | const char *name; | |
238 | name = regs_query_register_name((unsigned int)((long)ff->data)); | |
239 | ret = snprintf(buf, n, "%%%s", name); | |
240 | } else if (ff->func == fetch_stack) | |
2e06ff63 | 241 | ret = snprintf(buf, n, "$stack%lu", (unsigned long)ff->data); |
413d37d1 MH |
242 | else if (ff->func == fetch_memory) |
243 | ret = snprintf(buf, n, "@0x%p", ff->data); | |
244 | else if (ff->func == fetch_symbol) { | |
245 | struct symbol_cache *sc = ff->data; | |
246 | ret = snprintf(buf, n, "@%s%+ld", sc->symbol, sc->offset); | |
247 | } else if (ff->func == fetch_retvalue) | |
2e06ff63 | 248 | ret = snprintf(buf, n, "$retval"); |
413d37d1 | 249 | else if (ff->func == fetch_stack_address) |
2e06ff63 | 250 | ret = snprintf(buf, n, "$stack"); |
413d37d1 MH |
251 | else if (ff->func == fetch_indirect) { |
252 | struct indirect_fetch_data *id = ff->data; | |
253 | size_t l = 0; | |
254 | ret = snprintf(buf, n, "%+ld(", id->offset); | |
255 | if (ret >= n) | |
256 | goto end; | |
257 | l += ret; | |
30a7e073 | 258 | ret = probe_arg_string(buf + l, n - l, &id->orig); |
413d37d1 MH |
259 | if (ret < 0) |
260 | goto end; | |
261 | l += ret; | |
262 | ret = snprintf(buf + l, n - l, ")"); | |
263 | ret += l; | |
264 | } | |
265 | end: | |
266 | if (ret >= n) | |
267 | return -ENOSPC; | |
268 | return ret; | |
269 | } | |
270 | ||
271 | static int register_probe_event(struct trace_probe *tp); | |
272 | static void unregister_probe_event(struct trace_probe *tp); | |
273 | ||
274 | static DEFINE_MUTEX(probe_lock); | |
275 | static LIST_HEAD(probe_list); | |
276 | ||
50d78056 MH |
277 | static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs); |
278 | static int kretprobe_dispatcher(struct kretprobe_instance *ri, | |
279 | struct pt_regs *regs); | |
280 | ||
4a846b44 MH |
281 | /* |
282 | * Allocate new trace_probe and initialize it (including kprobes). | |
283 | */ | |
f52487e9 MH |
284 | static struct trace_probe *alloc_trace_probe(const char *group, |
285 | const char *event, | |
4a846b44 MH |
286 | void *addr, |
287 | const char *symbol, | |
288 | unsigned long offs, | |
289 | int nargs, int is_return) | |
413d37d1 MH |
290 | { |
291 | struct trace_probe *tp; | |
292 | ||
a82378d8 | 293 | tp = kzalloc(SIZEOF_TRACE_PROBE(nargs), GFP_KERNEL); |
413d37d1 MH |
294 | if (!tp) |
295 | return ERR_PTR(-ENOMEM); | |
296 | ||
297 | if (symbol) { | |
298 | tp->symbol = kstrdup(symbol, GFP_KERNEL); | |
299 | if (!tp->symbol) | |
300 | goto error; | |
4a846b44 MH |
301 | tp->rp.kp.symbol_name = tp->symbol; |
302 | tp->rp.kp.offset = offs; | |
303 | } else | |
304 | tp->rp.kp.addr = addr; | |
305 | ||
306 | if (is_return) | |
50d78056 | 307 | tp->rp.handler = kretprobe_dispatcher; |
4a846b44 | 308 | else |
50d78056 | 309 | tp->rp.kp.pre_handler = kprobe_dispatcher; |
4a846b44 | 310 | |
4263565d MH |
311 | if (!event) |
312 | goto error; | |
313 | tp->call.name = kstrdup(event, GFP_KERNEL); | |
314 | if (!tp->call.name) | |
315 | goto error; | |
413d37d1 | 316 | |
f52487e9 MH |
317 | if (!group) |
318 | goto error; | |
319 | tp->call.system = kstrdup(group, GFP_KERNEL); | |
320 | if (!tp->call.system) | |
321 | goto error; | |
322 | ||
413d37d1 MH |
323 | INIT_LIST_HEAD(&tp->list); |
324 | return tp; | |
325 | error: | |
f52487e9 | 326 | kfree(tp->call.name); |
413d37d1 MH |
327 | kfree(tp->symbol); |
328 | kfree(tp); | |
329 | return ERR_PTR(-ENOMEM); | |
330 | } | |
331 | ||
eca0d916 MH |
332 | static void free_probe_arg(struct probe_arg *arg) |
333 | { | |
334 | if (arg->fetch.func == fetch_symbol) | |
335 | free_symbol_cache(arg->fetch.data); | |
336 | else if (arg->fetch.func == fetch_indirect) | |
337 | free_indirect_fetch_data(arg->fetch.data); | |
338 | kfree(arg->name); | |
339 | } | |
340 | ||
413d37d1 MH |
341 | static void free_trace_probe(struct trace_probe *tp) |
342 | { | |
343 | int i; | |
344 | ||
345 | for (i = 0; i < tp->nr_args; i++) | |
eca0d916 | 346 | free_probe_arg(&tp->args[i]); |
413d37d1 | 347 | |
f52487e9 | 348 | kfree(tp->call.system); |
413d37d1 MH |
349 | kfree(tp->call.name); |
350 | kfree(tp->symbol); | |
351 | kfree(tp); | |
352 | } | |
353 | ||
dd004c47 MH |
354 | static struct trace_probe *find_probe_event(const char *event, |
355 | const char *group) | |
413d37d1 MH |
356 | { |
357 | struct trace_probe *tp; | |
358 | ||
359 | list_for_each_entry(tp, &probe_list, list) | |
dd004c47 MH |
360 | if (strcmp(tp->call.name, event) == 0 && |
361 | strcmp(tp->call.system, group) == 0) | |
413d37d1 MH |
362 | return tp; |
363 | return NULL; | |
364 | } | |
365 | ||
2d5e067e MH |
366 | /* Unregister a trace_probe and probe_event: call with locking probe_lock */ |
367 | static void unregister_trace_probe(struct trace_probe *tp) | |
413d37d1 MH |
368 | { |
369 | if (probe_is_return(tp)) | |
370 | unregister_kretprobe(&tp->rp); | |
371 | else | |
4a846b44 | 372 | unregister_kprobe(&tp->rp.kp); |
413d37d1 | 373 | list_del(&tp->list); |
2d5e067e | 374 | unregister_probe_event(tp); |
413d37d1 MH |
375 | } |
376 | ||
377 | /* Register a trace_probe and probe_event */ | |
378 | static int register_trace_probe(struct trace_probe *tp) | |
379 | { | |
380 | struct trace_probe *old_tp; | |
381 | int ret; | |
382 | ||
383 | mutex_lock(&probe_lock); | |
384 | ||
2d5e067e | 385 | /* register as an event */ |
dd004c47 | 386 | old_tp = find_probe_event(tp->call.name, tp->call.system); |
2d5e067e MH |
387 | if (old_tp) { |
388 | /* delete old event */ | |
389 | unregister_trace_probe(old_tp); | |
390 | free_trace_probe(old_tp); | |
391 | } | |
392 | ret = register_probe_event(tp); | |
393 | if (ret) { | |
394 | pr_warning("Faild to register probe event(%d)\n", ret); | |
395 | goto end; | |
396 | } | |
397 | ||
5a0d9050 | 398 | tp->rp.kp.flags |= KPROBE_FLAG_DISABLED; |
413d37d1 MH |
399 | if (probe_is_return(tp)) |
400 | ret = register_kretprobe(&tp->rp); | |
401 | else | |
4a846b44 | 402 | ret = register_kprobe(&tp->rp.kp); |
413d37d1 MH |
403 | |
404 | if (ret) { | |
405 | pr_warning("Could not insert probe(%d)\n", ret); | |
406 | if (ret == -EILSEQ) { | |
407 | pr_warning("Probing address(0x%p) is not an " | |
408 | "instruction boundary.\n", | |
4a846b44 | 409 | tp->rp.kp.addr); |
413d37d1 MH |
410 | ret = -EINVAL; |
411 | } | |
2d5e067e MH |
412 | unregister_probe_event(tp); |
413 | } else | |
414 | list_add_tail(&tp->list, &probe_list); | |
413d37d1 MH |
415 | end: |
416 | mutex_unlock(&probe_lock); | |
417 | return ret; | |
418 | } | |
419 | ||
420 | /* Split symbol and offset. */ | |
2fba0c88 | 421 | static int split_symbol_offset(char *symbol, unsigned long *offset) |
413d37d1 MH |
422 | { |
423 | char *tmp; | |
424 | int ret; | |
425 | ||
426 | if (!offset) | |
427 | return -EINVAL; | |
428 | ||
429 | tmp = strchr(symbol, '+'); | |
413d37d1 MH |
430 | if (tmp) { |
431 | /* skip sign because strict_strtol doesn't accept '+' */ | |
2fba0c88 | 432 | ret = strict_strtoul(tmp + 1, 0, offset); |
413d37d1 MH |
433 | if (ret) |
434 | return ret; | |
413d37d1 MH |
435 | *tmp = '\0'; |
436 | } else | |
437 | *offset = 0; | |
438 | return 0; | |
439 | } | |
440 | ||
441 | #define PARAM_MAX_ARGS 16 | |
442 | #define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long)) | |
443 | ||
405b2651 | 444 | static int parse_probe_vars(char *arg, struct fetch_func *ff, int is_return) |
413d37d1 MH |
445 | { |
446 | int ret = 0; | |
447 | unsigned long param; | |
413d37d1 | 448 | |
2e06ff63 MH |
449 | if (strcmp(arg, "retval") == 0) { |
450 | if (is_return) { | |
413d37d1 MH |
451 | ff->func = fetch_retvalue; |
452 | ff->data = NULL; | |
413d37d1 MH |
453 | } else |
454 | ret = -EINVAL; | |
2e06ff63 MH |
455 | } else if (strncmp(arg, "stack", 5) == 0) { |
456 | if (arg[5] == '\0') { | |
413d37d1 MH |
457 | ff->func = fetch_stack_address; |
458 | ff->data = NULL; | |
2e06ff63 MH |
459 | } else if (isdigit(arg[5])) { |
460 | ret = strict_strtoul(arg + 5, 10, ¶m); | |
413d37d1 MH |
461 | if (ret || param > PARAM_MAX_STACK) |
462 | ret = -EINVAL; | |
463 | else { | |
464 | ff->func = fetch_stack; | |
465 | ff->data = (void *)param; | |
466 | } | |
2e06ff63 MH |
467 | } else |
468 | ret = -EINVAL; | |
469 | } else if (strncmp(arg, "arg", 3) == 0 && isdigit(arg[3])) { | |
470 | ret = strict_strtoul(arg + 3, 10, ¶m); | |
471 | if (ret || param > PARAM_MAX_ARGS) | |
472 | ret = -EINVAL; | |
473 | else { | |
474 | ff->func = fetch_argument; | |
475 | ff->data = (void *)param; | |
413d37d1 | 476 | } |
2e06ff63 | 477 | } else |
405b2651 | 478 | ret = -EINVAL; |
405b2651 MH |
479 | return ret; |
480 | } | |
481 | ||
482 | static int parse_probe_arg(char *arg, struct fetch_func *ff, int is_return) | |
483 | { | |
484 | int ret = 0; | |
485 | unsigned long param; | |
486 | long offset; | |
487 | char *tmp; | |
488 | ||
489 | switch (arg[0]) { | |
490 | case '$': | |
491 | ret = parse_probe_vars(arg + 1, ff, is_return); | |
492 | break; | |
493 | case '%': /* named register */ | |
494 | ret = regs_query_register_offset(arg + 1); | |
495 | if (ret >= 0) { | |
496 | ff->func = fetch_register; | |
497 | ff->data = (void *)(unsigned long)ret; | |
498 | ret = 0; | |
499 | } | |
500 | break; | |
413d37d1 MH |
501 | case '@': /* memory or symbol */ |
502 | if (isdigit(arg[1])) { | |
503 | ret = strict_strtoul(arg + 1, 0, ¶m); | |
504 | if (ret) | |
505 | break; | |
506 | ff->func = fetch_memory; | |
507 | ff->data = (void *)param; | |
508 | } else { | |
509 | ret = split_symbol_offset(arg + 1, &offset); | |
510 | if (ret) | |
511 | break; | |
405b2651 | 512 | ff->data = alloc_symbol_cache(arg + 1, offset); |
413d37d1 MH |
513 | if (ff->data) |
514 | ff->func = fetch_symbol; | |
515 | else | |
516 | ret = -EINVAL; | |
517 | } | |
518 | break; | |
519 | case '+': /* indirect memory */ | |
520 | case '-': | |
521 | tmp = strchr(arg, '('); | |
522 | if (!tmp) { | |
523 | ret = -EINVAL; | |
524 | break; | |
525 | } | |
526 | *tmp = '\0'; | |
527 | ret = strict_strtol(arg + 1, 0, &offset); | |
528 | if (ret) | |
529 | break; | |
530 | if (arg[0] == '-') | |
531 | offset = -offset; | |
532 | arg = tmp + 1; | |
533 | tmp = strrchr(arg, ')'); | |
534 | if (tmp) { | |
535 | struct indirect_fetch_data *id; | |
536 | *tmp = '\0'; | |
537 | id = kzalloc(sizeof(struct indirect_fetch_data), | |
538 | GFP_KERNEL); | |
539 | if (!id) | |
540 | return -ENOMEM; | |
541 | id->offset = offset; | |
30a7e073 | 542 | ret = parse_probe_arg(arg, &id->orig, is_return); |
413d37d1 MH |
543 | if (ret) |
544 | kfree(id); | |
545 | else { | |
546 | ff->func = fetch_indirect; | |
547 | ff->data = (void *)id; | |
548 | } | |
549 | } else | |
550 | ret = -EINVAL; | |
551 | break; | |
552 | default: | |
553 | /* TODO: support custom handler */ | |
554 | ret = -EINVAL; | |
555 | } | |
556 | return ret; | |
557 | } | |
558 | ||
a703d946 MH |
559 | /* Return 1 if name is reserved or already used by another argument */ |
560 | static int conflict_field_name(const char *name, | |
561 | struct probe_arg *args, int narg) | |
562 | { | |
563 | int i; | |
564 | for (i = 0; i < ARRAY_SIZE(reserved_field_names); i++) | |
565 | if (strcmp(reserved_field_names[i], name) == 0) | |
566 | return 1; | |
567 | for (i = 0; i < narg; i++) | |
568 | if (strcmp(args[i].name, name) == 0) | |
569 | return 1; | |
570 | return 0; | |
571 | } | |
572 | ||
413d37d1 MH |
573 | static int create_trace_probe(int argc, char **argv) |
574 | { | |
575 | /* | |
576 | * Argument syntax: | |
f52487e9 MH |
577 | * - Add kprobe: p[:[GRP/]EVENT] KSYM[+OFFS]|KADDR [FETCHARGS] |
578 | * - Add kretprobe: r[:[GRP/]EVENT] KSYM[+0] [FETCHARGS] | |
413d37d1 | 579 | * Fetch args: |
2e06ff63 MH |
580 | * $argN : fetch Nth of function argument. (N:0-) |
581 | * $retval : fetch return value | |
582 | * $stack : fetch stack address | |
583 | * $stackN : fetch Nth of stack (N:0-) | |
413d37d1 MH |
584 | * @ADDR : fetch memory at ADDR (ADDR should be in kernel) |
585 | * @SYM[+|-offs] : fetch memory at SYM +|- offs (SYM is a data symbol) | |
586 | * %REG : fetch register REG | |
587 | * Indirect memory fetch: | |
588 | * +|-offs(ARG) : fetch memory at ARG +|- offs address. | |
eca0d916 MH |
589 | * Alias name of args: |
590 | * NAME=FETCHARG : set NAME as alias of FETCHARG. | |
413d37d1 MH |
591 | */ |
592 | struct trace_probe *tp; | |
413d37d1 MH |
593 | int i, ret = 0; |
594 | int is_return = 0; | |
f52487e9 | 595 | char *symbol = NULL, *event = NULL, *arg = NULL, *group = NULL; |
2fba0c88 | 596 | unsigned long offset = 0; |
413d37d1 | 597 | void *addr = NULL; |
4a846b44 | 598 | char buf[MAX_EVENT_NAME_LEN]; |
413d37d1 | 599 | |
e63cc239 MH |
600 | if (argc < 2) { |
601 | pr_info("Probe point is not specified.\n"); | |
413d37d1 | 602 | return -EINVAL; |
e63cc239 | 603 | } |
413d37d1 MH |
604 | |
605 | if (argv[0][0] == 'p') | |
606 | is_return = 0; | |
607 | else if (argv[0][0] == 'r') | |
608 | is_return = 1; | |
e63cc239 MH |
609 | else { |
610 | pr_info("Probe definition must be started with 'p' or 'r'.\n"); | |
413d37d1 | 611 | return -EINVAL; |
e63cc239 | 612 | } |
413d37d1 MH |
613 | |
614 | if (argv[0][1] == ':') { | |
615 | event = &argv[0][2]; | |
f52487e9 MH |
616 | if (strchr(event, '/')) { |
617 | group = event; | |
618 | event = strchr(group, '/') + 1; | |
619 | event[-1] = '\0'; | |
620 | if (strlen(group) == 0) { | |
621 | pr_info("Group name is not specifiled\n"); | |
622 | return -EINVAL; | |
623 | } | |
624 | } | |
413d37d1 MH |
625 | if (strlen(event) == 0) { |
626 | pr_info("Event name is not specifiled\n"); | |
627 | return -EINVAL; | |
628 | } | |
629 | } | |
630 | ||
631 | if (isdigit(argv[1][0])) { | |
e63cc239 MH |
632 | if (is_return) { |
633 | pr_info("Return probe point must be a symbol.\n"); | |
413d37d1 | 634 | return -EINVAL; |
e63cc239 | 635 | } |
413d37d1 MH |
636 | /* an address specified */ |
637 | ret = strict_strtoul(&argv[0][2], 0, (unsigned long *)&addr); | |
e63cc239 MH |
638 | if (ret) { |
639 | pr_info("Failed to parse address.\n"); | |
413d37d1 | 640 | return ret; |
e63cc239 | 641 | } |
413d37d1 MH |
642 | } else { |
643 | /* a symbol specified */ | |
644 | symbol = argv[1]; | |
645 | /* TODO: support .init module functions */ | |
646 | ret = split_symbol_offset(symbol, &offset); | |
e63cc239 MH |
647 | if (ret) { |
648 | pr_info("Failed to parse symbol.\n"); | |
413d37d1 | 649 | return ret; |
e63cc239 MH |
650 | } |
651 | if (offset && is_return) { | |
652 | pr_info("Return probe must be used without offset.\n"); | |
413d37d1 | 653 | return -EINVAL; |
e63cc239 | 654 | } |
413d37d1 | 655 | } |
a82378d8 | 656 | argc -= 2; argv += 2; |
413d37d1 MH |
657 | |
658 | /* setup a probe */ | |
f52487e9 MH |
659 | if (!group) |
660 | group = KPROBE_EVENT_SYSTEM; | |
4263565d MH |
661 | if (!event) { |
662 | /* Make a new event name */ | |
4263565d MH |
663 | if (symbol) |
664 | snprintf(buf, MAX_EVENT_NAME_LEN, "%c@%s%+ld", | |
665 | is_return ? 'r' : 'p', symbol, offset); | |
666 | else | |
667 | snprintf(buf, MAX_EVENT_NAME_LEN, "%c@0x%p", | |
668 | is_return ? 'r' : 'p', addr); | |
4a846b44 MH |
669 | event = buf; |
670 | } | |
f52487e9 MH |
671 | tp = alloc_trace_probe(group, event, addr, symbol, offset, argc, |
672 | is_return); | |
e63cc239 MH |
673 | if (IS_ERR(tp)) { |
674 | pr_info("Failed to allocate trace_probe.(%d)\n", | |
675 | (int)PTR_ERR(tp)); | |
413d37d1 | 676 | return PTR_ERR(tp); |
e63cc239 | 677 | } |
413d37d1 | 678 | |
413d37d1 | 679 | /* parse arguments */ |
a82378d8 MH |
680 | ret = 0; |
681 | for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) { | |
eca0d916 MH |
682 | /* Parse argument name */ |
683 | arg = strchr(argv[i], '='); | |
684 | if (arg) | |
685 | *arg++ = '\0'; | |
686 | else | |
687 | arg = argv[i]; | |
a703d946 MH |
688 | |
689 | if (conflict_field_name(argv[i], tp->args, i)) { | |
e63cc239 MH |
690 | pr_info("Argument%d name '%s' conflicts with " |
691 | "another field.\n", i, argv[i]); | |
a703d946 MH |
692 | ret = -EINVAL; |
693 | goto error; | |
694 | } | |
695 | ||
eca0d916 MH |
696 | tp->args[i].name = kstrdup(argv[i], GFP_KERNEL); |
697 | ||
698 | /* Parse fetch argument */ | |
699 | if (strlen(arg) > MAX_ARGSTR_LEN) { | |
700 | pr_info("Argument%d(%s) is too long.\n", i, arg); | |
413d37d1 MH |
701 | ret = -ENOSPC; |
702 | goto error; | |
703 | } | |
eca0d916 | 704 | ret = parse_probe_arg(arg, &tp->args[i].fetch, is_return); |
e63cc239 MH |
705 | if (ret) { |
706 | pr_info("Parse error at argument%d. (%d)\n", i, ret); | |
abab9d37 | 707 | kfree(tp->args[i].name); |
413d37d1 | 708 | goto error; |
e63cc239 | 709 | } |
abab9d37 LJ |
710 | |
711 | tp->nr_args++; | |
413d37d1 | 712 | } |
413d37d1 MH |
713 | |
714 | ret = register_trace_probe(tp); | |
715 | if (ret) | |
716 | goto error; | |
717 | return 0; | |
718 | ||
719 | error: | |
720 | free_trace_probe(tp); | |
721 | return ret; | |
722 | } | |
723 | ||
724 | static void cleanup_all_probes(void) | |
725 | { | |
726 | struct trace_probe *tp; | |
727 | ||
728 | mutex_lock(&probe_lock); | |
729 | /* TODO: Use batch unregistration */ | |
730 | while (!list_empty(&probe_list)) { | |
731 | tp = list_entry(probe_list.next, struct trace_probe, list); | |
732 | unregister_trace_probe(tp); | |
733 | free_trace_probe(tp); | |
734 | } | |
735 | mutex_unlock(&probe_lock); | |
736 | } | |
737 | ||
738 | ||
739 | /* Probes listing interfaces */ | |
740 | static void *probes_seq_start(struct seq_file *m, loff_t *pos) | |
741 | { | |
742 | mutex_lock(&probe_lock); | |
743 | return seq_list_start(&probe_list, *pos); | |
744 | } | |
745 | ||
746 | static void *probes_seq_next(struct seq_file *m, void *v, loff_t *pos) | |
747 | { | |
748 | return seq_list_next(v, &probe_list, pos); | |
749 | } | |
750 | ||
751 | static void probes_seq_stop(struct seq_file *m, void *v) | |
752 | { | |
753 | mutex_unlock(&probe_lock); | |
754 | } | |
755 | ||
756 | static int probes_seq_show(struct seq_file *m, void *v) | |
757 | { | |
758 | struct trace_probe *tp = v; | |
759 | int i, ret; | |
760 | char buf[MAX_ARGSTR_LEN + 1]; | |
761 | ||
762 | seq_printf(m, "%c", probe_is_return(tp) ? 'r' : 'p'); | |
3d9b2e1d | 763 | seq_printf(m, ":%s/%s", tp->call.system, tp->call.name); |
413d37d1 MH |
764 | |
765 | if (tp->symbol) | |
4a846b44 | 766 | seq_printf(m, " %s+%u", probe_symbol(tp), tp->rp.kp.offset); |
413d37d1 | 767 | else |
4a846b44 | 768 | seq_printf(m, " 0x%p", tp->rp.kp.addr); |
413d37d1 MH |
769 | |
770 | for (i = 0; i < tp->nr_args; i++) { | |
eca0d916 | 771 | ret = probe_arg_string(buf, MAX_ARGSTR_LEN, &tp->args[i].fetch); |
413d37d1 MH |
772 | if (ret < 0) { |
773 | pr_warning("Argument%d decoding error(%d).\n", i, ret); | |
774 | return ret; | |
775 | } | |
eca0d916 | 776 | seq_printf(m, " %s=%s", tp->args[i].name, buf); |
413d37d1 MH |
777 | } |
778 | seq_printf(m, "\n"); | |
779 | return 0; | |
780 | } | |
781 | ||
782 | static const struct seq_operations probes_seq_op = { | |
783 | .start = probes_seq_start, | |
784 | .next = probes_seq_next, | |
785 | .stop = probes_seq_stop, | |
786 | .show = probes_seq_show | |
787 | }; | |
788 | ||
789 | static int probes_open(struct inode *inode, struct file *file) | |
790 | { | |
791 | if ((file->f_mode & FMODE_WRITE) && | |
792 | (file->f_flags & O_TRUNC)) | |
793 | cleanup_all_probes(); | |
794 | ||
795 | return seq_open(file, &probes_seq_op); | |
796 | } | |
797 | ||
798 | static int command_trace_probe(const char *buf) | |
799 | { | |
800 | char **argv; | |
801 | int argc = 0, ret = 0; | |
802 | ||
803 | argv = argv_split(GFP_KERNEL, buf, &argc); | |
804 | if (!argv) | |
805 | return -ENOMEM; | |
806 | ||
807 | if (argc) | |
808 | ret = create_trace_probe(argc, argv); | |
809 | ||
810 | argv_free(argv); | |
811 | return ret; | |
812 | } | |
813 | ||
814 | #define WRITE_BUFSIZE 128 | |
815 | ||
816 | static ssize_t probes_write(struct file *file, const char __user *buffer, | |
817 | size_t count, loff_t *ppos) | |
818 | { | |
819 | char *kbuf, *tmp; | |
820 | int ret; | |
821 | size_t done; | |
822 | size_t size; | |
823 | ||
824 | kbuf = kmalloc(WRITE_BUFSIZE, GFP_KERNEL); | |
825 | if (!kbuf) | |
826 | return -ENOMEM; | |
827 | ||
828 | ret = done = 0; | |
829 | while (done < count) { | |
830 | size = count - done; | |
831 | if (size >= WRITE_BUFSIZE) | |
832 | size = WRITE_BUFSIZE - 1; | |
833 | if (copy_from_user(kbuf, buffer + done, size)) { | |
834 | ret = -EFAULT; | |
835 | goto out; | |
836 | } | |
837 | kbuf[size] = '\0'; | |
838 | tmp = strchr(kbuf, '\n'); | |
839 | if (tmp) { | |
840 | *tmp = '\0'; | |
841 | size = tmp - kbuf + 1; | |
842 | } else if (done + size < count) { | |
843 | pr_warning("Line length is too long: " | |
844 | "Should be less than %d.", WRITE_BUFSIZE); | |
845 | ret = -EINVAL; | |
846 | goto out; | |
847 | } | |
848 | done += size; | |
849 | /* Remove comments */ | |
850 | tmp = strchr(kbuf, '#'); | |
851 | if (tmp) | |
852 | *tmp = '\0'; | |
853 | ||
854 | ret = command_trace_probe(kbuf); | |
855 | if (ret) | |
856 | goto out; | |
857 | } | |
858 | ret = done; | |
859 | out: | |
860 | kfree(kbuf); | |
861 | return ret; | |
862 | } | |
863 | ||
864 | static const struct file_operations kprobe_events_ops = { | |
865 | .owner = THIS_MODULE, | |
866 | .open = probes_open, | |
867 | .read = seq_read, | |
868 | .llseek = seq_lseek, | |
869 | .release = seq_release, | |
870 | .write = probes_write, | |
871 | }; | |
872 | ||
cd7e7bd5 MH |
873 | /* Probes profiling interfaces */ |
874 | static int probes_profile_seq_show(struct seq_file *m, void *v) | |
875 | { | |
876 | struct trace_probe *tp = v; | |
877 | ||
878 | seq_printf(m, " %-44s %15lu %15lu\n", tp->call.name, tp->nhit, | |
4a846b44 | 879 | tp->rp.kp.nmissed); |
cd7e7bd5 MH |
880 | |
881 | return 0; | |
882 | } | |
883 | ||
884 | static const struct seq_operations profile_seq_op = { | |
885 | .start = probes_seq_start, | |
886 | .next = probes_seq_next, | |
887 | .stop = probes_seq_stop, | |
888 | .show = probes_profile_seq_show | |
889 | }; | |
890 | ||
891 | static int profile_open(struct inode *inode, struct file *file) | |
892 | { | |
893 | return seq_open(file, &profile_seq_op); | |
894 | } | |
895 | ||
896 | static const struct file_operations kprobe_profile_ops = { | |
897 | .owner = THIS_MODULE, | |
898 | .open = profile_open, | |
899 | .read = seq_read, | |
900 | .llseek = seq_lseek, | |
901 | .release = seq_release, | |
902 | }; | |
903 | ||
413d37d1 MH |
904 | /* Kprobe handler */ |
905 | static __kprobes int kprobe_trace_func(struct kprobe *kp, struct pt_regs *regs) | |
906 | { | |
4a846b44 | 907 | struct trace_probe *tp = container_of(kp, struct trace_probe, rp.kp); |
413d37d1 MH |
908 | struct kprobe_trace_entry *entry; |
909 | struct ring_buffer_event *event; | |
8f8ffe24 | 910 | struct ring_buffer *buffer; |
413d37d1 MH |
911 | int size, i, pc; |
912 | unsigned long irq_flags; | |
4263565d | 913 | struct ftrace_event_call *call = &tp->call; |
413d37d1 | 914 | |
cd7e7bd5 MH |
915 | tp->nhit++; |
916 | ||
413d37d1 MH |
917 | local_save_flags(irq_flags); |
918 | pc = preempt_count(); | |
919 | ||
920 | size = SIZEOF_KPROBE_TRACE_ENTRY(tp->nr_args); | |
921 | ||
8f8ffe24 | 922 | event = trace_current_buffer_lock_reserve(&buffer, call->id, size, |
413d37d1 MH |
923 | irq_flags, pc); |
924 | if (!event) | |
925 | return 0; | |
926 | ||
927 | entry = ring_buffer_event_data(event); | |
928 | entry->nargs = tp->nr_args; | |
929 | entry->ip = (unsigned long)kp->addr; | |
930 | for (i = 0; i < tp->nr_args; i++) | |
eca0d916 | 931 | entry->args[i] = call_fetch(&tp->args[i].fetch, regs); |
413d37d1 | 932 | |
8f8ffe24 FW |
933 | if (!filter_current_check_discard(buffer, call, entry, event)) |
934 | trace_nowake_buffer_unlock_commit(buffer, event, irq_flags, pc); | |
413d37d1 MH |
935 | return 0; |
936 | } | |
937 | ||
938 | /* Kretprobe handler */ | |
939 | static __kprobes int kretprobe_trace_func(struct kretprobe_instance *ri, | |
940 | struct pt_regs *regs) | |
941 | { | |
942 | struct trace_probe *tp = container_of(ri->rp, struct trace_probe, rp); | |
943 | struct kretprobe_trace_entry *entry; | |
944 | struct ring_buffer_event *event; | |
8f8ffe24 | 945 | struct ring_buffer *buffer; |
413d37d1 MH |
946 | int size, i, pc; |
947 | unsigned long irq_flags; | |
4263565d | 948 | struct ftrace_event_call *call = &tp->call; |
413d37d1 MH |
949 | |
950 | local_save_flags(irq_flags); | |
951 | pc = preempt_count(); | |
952 | ||
953 | size = SIZEOF_KRETPROBE_TRACE_ENTRY(tp->nr_args); | |
954 | ||
8f8ffe24 | 955 | event = trace_current_buffer_lock_reserve(&buffer, call->id, size, |
413d37d1 MH |
956 | irq_flags, pc); |
957 | if (!event) | |
958 | return 0; | |
959 | ||
960 | entry = ring_buffer_event_data(event); | |
961 | entry->nargs = tp->nr_args; | |
4a846b44 | 962 | entry->func = (unsigned long)tp->rp.kp.addr; |
413d37d1 MH |
963 | entry->ret_ip = (unsigned long)ri->ret_addr; |
964 | for (i = 0; i < tp->nr_args; i++) | |
eca0d916 | 965 | entry->args[i] = call_fetch(&tp->args[i].fetch, regs); |
413d37d1 | 966 | |
8f8ffe24 FW |
967 | if (!filter_current_check_discard(buffer, call, entry, event)) |
968 | trace_nowake_buffer_unlock_commit(buffer, event, irq_flags, pc); | |
413d37d1 MH |
969 | |
970 | return 0; | |
971 | } | |
972 | ||
973 | /* Event entry printers */ | |
974 | enum print_line_t | |
975 | print_kprobe_event(struct trace_iterator *iter, int flags) | |
976 | { | |
977 | struct kprobe_trace_entry *field; | |
978 | struct trace_seq *s = &iter->seq; | |
eca0d916 MH |
979 | struct trace_event *event; |
980 | struct trace_probe *tp; | |
413d37d1 MH |
981 | int i; |
982 | ||
ff50d991 | 983 | field = (struct kprobe_trace_entry *)iter->ent; |
eca0d916 MH |
984 | event = ftrace_find_event(field->ent.type); |
985 | tp = container_of(event, struct trace_probe, event); | |
413d37d1 | 986 | |
6e9f23d1 MH |
987 | if (!trace_seq_printf(s, "%s: (", tp->call.name)) |
988 | goto partial; | |
989 | ||
413d37d1 MH |
990 | if (!seq_print_ip_sym(s, field->ip, flags | TRACE_ITER_SYM_OFFSET)) |
991 | goto partial; | |
992 | ||
6e9f23d1 | 993 | if (!trace_seq_puts(s, ")")) |
413d37d1 MH |
994 | goto partial; |
995 | ||
996 | for (i = 0; i < field->nargs; i++) | |
eca0d916 MH |
997 | if (!trace_seq_printf(s, " %s=%lx", |
998 | tp->args[i].name, field->args[i])) | |
413d37d1 MH |
999 | goto partial; |
1000 | ||
1001 | if (!trace_seq_puts(s, "\n")) | |
1002 | goto partial; | |
1003 | ||
1004 | return TRACE_TYPE_HANDLED; | |
1005 | partial: | |
1006 | return TRACE_TYPE_PARTIAL_LINE; | |
1007 | } | |
1008 | ||
1009 | enum print_line_t | |
1010 | print_kretprobe_event(struct trace_iterator *iter, int flags) | |
1011 | { | |
1012 | struct kretprobe_trace_entry *field; | |
1013 | struct trace_seq *s = &iter->seq; | |
eca0d916 MH |
1014 | struct trace_event *event; |
1015 | struct trace_probe *tp; | |
413d37d1 MH |
1016 | int i; |
1017 | ||
ff50d991 | 1018 | field = (struct kretprobe_trace_entry *)iter->ent; |
eca0d916 MH |
1019 | event = ftrace_find_event(field->ent.type); |
1020 | tp = container_of(event, struct trace_probe, event); | |
413d37d1 | 1021 | |
6e9f23d1 MH |
1022 | if (!trace_seq_printf(s, "%s: (", tp->call.name)) |
1023 | goto partial; | |
1024 | ||
413d37d1 MH |
1025 | if (!seq_print_ip_sym(s, field->ret_ip, flags | TRACE_ITER_SYM_OFFSET)) |
1026 | goto partial; | |
1027 | ||
1028 | if (!trace_seq_puts(s, " <- ")) | |
1029 | goto partial; | |
1030 | ||
1031 | if (!seq_print_ip_sym(s, field->func, flags & ~TRACE_ITER_SYM_OFFSET)) | |
1032 | goto partial; | |
1033 | ||
6e9f23d1 | 1034 | if (!trace_seq_puts(s, ")")) |
413d37d1 MH |
1035 | goto partial; |
1036 | ||
1037 | for (i = 0; i < field->nargs; i++) | |
eca0d916 MH |
1038 | if (!trace_seq_printf(s, " %s=%lx", |
1039 | tp->args[i].name, field->args[i])) | |
413d37d1 MH |
1040 | goto partial; |
1041 | ||
1042 | if (!trace_seq_puts(s, "\n")) | |
1043 | goto partial; | |
1044 | ||
1045 | return TRACE_TYPE_HANDLED; | |
1046 | partial: | |
1047 | return TRACE_TYPE_PARTIAL_LINE; | |
1048 | } | |
1049 | ||
413d37d1 MH |
1050 | static int probe_event_enable(struct ftrace_event_call *call) |
1051 | { | |
1052 | struct trace_probe *tp = (struct trace_probe *)call->data; | |
1053 | ||
50d78056 MH |
1054 | tp->flags |= TP_FLAG_TRACE; |
1055 | if (probe_is_return(tp)) | |
413d37d1 | 1056 | return enable_kretprobe(&tp->rp); |
50d78056 | 1057 | else |
4a846b44 | 1058 | return enable_kprobe(&tp->rp.kp); |
413d37d1 MH |
1059 | } |
1060 | ||
1061 | static void probe_event_disable(struct ftrace_event_call *call) | |
1062 | { | |
1063 | struct trace_probe *tp = (struct trace_probe *)call->data; | |
1064 | ||
50d78056 MH |
1065 | tp->flags &= ~TP_FLAG_TRACE; |
1066 | if (!(tp->flags & (TP_FLAG_TRACE | TP_FLAG_PROFILE))) { | |
1067 | if (probe_is_return(tp)) | |
1068 | disable_kretprobe(&tp->rp); | |
1069 | else | |
1070 | disable_kprobe(&tp->rp.kp); | |
1071 | } | |
413d37d1 MH |
1072 | } |
1073 | ||
1074 | static int probe_event_raw_init(struct ftrace_event_call *event_call) | |
1075 | { | |
1076 | INIT_LIST_HEAD(&event_call->fields); | |
8f8ffe24 | 1077 | |
413d37d1 MH |
1078 | return 0; |
1079 | } | |
1080 | ||
1081 | #undef DEFINE_FIELD | |
1082 | #define DEFINE_FIELD(type, item, name, is_signed) \ | |
1083 | do { \ | |
1084 | ret = trace_define_field(event_call, #type, name, \ | |
1085 | offsetof(typeof(field), item), \ | |
1086 | sizeof(field.item), is_signed, \ | |
1087 | FILTER_OTHER); \ | |
1088 | if (ret) \ | |
1089 | return ret; \ | |
1090 | } while (0) | |
1091 | ||
1092 | static int kprobe_event_define_fields(struct ftrace_event_call *event_call) | |
1093 | { | |
1094 | int ret, i; | |
1095 | struct kprobe_trace_entry field; | |
413d37d1 MH |
1096 | struct trace_probe *tp = (struct trace_probe *)event_call->data; |
1097 | ||
1098 | ret = trace_define_common_fields(event_call); | |
1099 | if (!ret) | |
1100 | return ret; | |
1101 | ||
a703d946 MH |
1102 | DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0); |
1103 | DEFINE_FIELD(int, nargs, FIELD_STRING_NARGS, 1); | |
eca0d916 MH |
1104 | /* Set argument names as fields */ |
1105 | for (i = 0; i < tp->nr_args; i++) | |
1106 | DEFINE_FIELD(unsigned long, args[i], tp->args[i].name, 0); | |
413d37d1 MH |
1107 | return 0; |
1108 | } | |
1109 | ||
1110 | static int kretprobe_event_define_fields(struct ftrace_event_call *event_call) | |
1111 | { | |
1112 | int ret, i; | |
1113 | struct kretprobe_trace_entry field; | |
413d37d1 MH |
1114 | struct trace_probe *tp = (struct trace_probe *)event_call->data; |
1115 | ||
1116 | ret = trace_define_common_fields(event_call); | |
1117 | if (!ret) | |
1118 | return ret; | |
1119 | ||
a703d946 MH |
1120 | DEFINE_FIELD(unsigned long, func, FIELD_STRING_FUNC, 0); |
1121 | DEFINE_FIELD(unsigned long, ret_ip, FIELD_STRING_RETIP, 0); | |
1122 | DEFINE_FIELD(int, nargs, FIELD_STRING_NARGS, 1); | |
eca0d916 MH |
1123 | /* Set argument names as fields */ |
1124 | for (i = 0; i < tp->nr_args; i++) | |
1125 | DEFINE_FIELD(unsigned long, args[i], tp->args[i].name, 0); | |
413d37d1 MH |
1126 | return 0; |
1127 | } | |
1128 | ||
1129 | static int __probe_event_show_format(struct trace_seq *s, | |
1130 | struct trace_probe *tp, const char *fmt, | |
1131 | const char *arg) | |
1132 | { | |
eca0d916 | 1133 | int i; |
413d37d1 | 1134 | |
413d37d1 MH |
1135 | /* Show format */ |
1136 | if (!trace_seq_printf(s, "\nprint fmt: \"%s", fmt)) | |
1137 | return 0; | |
1138 | ||
1139 | for (i = 0; i < tp->nr_args; i++) | |
eca0d916 | 1140 | if (!trace_seq_printf(s, " %s=%%lx", tp->args[i].name)) |
413d37d1 MH |
1141 | return 0; |
1142 | ||
1143 | if (!trace_seq_printf(s, "\", %s", arg)) | |
1144 | return 0; | |
1145 | ||
1146 | for (i = 0; i < tp->nr_args; i++) | |
eca0d916 | 1147 | if (!trace_seq_printf(s, ", REC->%s", tp->args[i].name)) |
413d37d1 MH |
1148 | return 0; |
1149 | ||
1150 | return trace_seq_puts(s, "\n"); | |
1151 | } | |
1152 | ||
1153 | #undef SHOW_FIELD | |
1154 | #define SHOW_FIELD(type, item, name) \ | |
1155 | do { \ | |
1156 | ret = trace_seq_printf(s, "\tfield: " #type " %s;\t" \ | |
38a47497 | 1157 | "offset:%u;\tsize:%u;\n", name, \ |
413d37d1 MH |
1158 | (unsigned int)offsetof(typeof(field), item),\ |
1159 | (unsigned int)sizeof(type)); \ | |
1160 | if (!ret) \ | |
1161 | return 0; \ | |
1162 | } while (0) | |
1163 | ||
1164 | static int kprobe_event_show_format(struct ftrace_event_call *call, | |
1165 | struct trace_seq *s) | |
1166 | { | |
1167 | struct kprobe_trace_entry field __attribute__((unused)); | |
1168 | int ret, i; | |
413d37d1 MH |
1169 | struct trace_probe *tp = (struct trace_probe *)call->data; |
1170 | ||
a703d946 MH |
1171 | SHOW_FIELD(unsigned long, ip, FIELD_STRING_IP); |
1172 | SHOW_FIELD(int, nargs, FIELD_STRING_NARGS); | |
413d37d1 MH |
1173 | |
1174 | /* Show fields */ | |
eca0d916 MH |
1175 | for (i = 0; i < tp->nr_args; i++) |
1176 | SHOW_FIELD(unsigned long, args[i], tp->args[i].name); | |
413d37d1 MH |
1177 | trace_seq_puts(s, "\n"); |
1178 | ||
a703d946 MH |
1179 | return __probe_event_show_format(s, tp, "(%lx)", |
1180 | "REC->" FIELD_STRING_IP); | |
413d37d1 MH |
1181 | } |
1182 | ||
1183 | static int kretprobe_event_show_format(struct ftrace_event_call *call, | |
1184 | struct trace_seq *s) | |
1185 | { | |
1186 | struct kretprobe_trace_entry field __attribute__((unused)); | |
1187 | int ret, i; | |
413d37d1 MH |
1188 | struct trace_probe *tp = (struct trace_probe *)call->data; |
1189 | ||
a703d946 MH |
1190 | SHOW_FIELD(unsigned long, func, FIELD_STRING_FUNC); |
1191 | SHOW_FIELD(unsigned long, ret_ip, FIELD_STRING_RETIP); | |
1192 | SHOW_FIELD(int, nargs, FIELD_STRING_NARGS); | |
413d37d1 MH |
1193 | |
1194 | /* Show fields */ | |
eca0d916 MH |
1195 | for (i = 0; i < tp->nr_args; i++) |
1196 | SHOW_FIELD(unsigned long, args[i], tp->args[i].name); | |
413d37d1 MH |
1197 | trace_seq_puts(s, "\n"); |
1198 | ||
6e9f23d1 | 1199 | return __probe_event_show_format(s, tp, "(%lx <- %lx)", |
a703d946 MH |
1200 | "REC->" FIELD_STRING_FUNC |
1201 | ", REC->" FIELD_STRING_RETIP); | |
413d37d1 MH |
1202 | } |
1203 | ||
e08d1c65 MH |
1204 | #ifdef CONFIG_EVENT_PROFILE |
1205 | ||
1206 | /* Kprobe profile handler */ | |
1207 | static __kprobes int kprobe_profile_func(struct kprobe *kp, | |
1208 | struct pt_regs *regs) | |
1209 | { | |
1210 | struct trace_probe *tp = container_of(kp, struct trace_probe, rp.kp); | |
1211 | struct ftrace_event_call *call = &tp->call; | |
1212 | struct kprobe_trace_entry *entry; | |
a1a138d0 MH |
1213 | struct trace_entry *ent; |
1214 | int size, __size, i, pc, __cpu; | |
e08d1c65 | 1215 | unsigned long irq_flags; |
ce71b9df | 1216 | char *trace_buf; |
a1a138d0 | 1217 | char *raw_data; |
4ed7c92d | 1218 | int rctx; |
e08d1c65 | 1219 | |
e08d1c65 | 1220 | pc = preempt_count(); |
74ebb63e MH |
1221 | __size = SIZEOF_KPROBE_TRACE_ENTRY(tp->nr_args); |
1222 | size = ALIGN(__size + sizeof(u32), sizeof(u64)); | |
1223 | size -= sizeof(u32); | |
a1a138d0 MH |
1224 | if (WARN_ONCE(size > FTRACE_MAX_PROFILE_SIZE, |
1225 | "profile buffer not large enough")) | |
1226 | return 0; | |
e08d1c65 | 1227 | |
a1a138d0 MH |
1228 | /* |
1229 | * Protect the non nmi buffer | |
1230 | * This also protects the rcu read side | |
1231 | */ | |
1232 | local_irq_save(irq_flags); | |
ce71b9df | 1233 | |
4ed7c92d PZ |
1234 | rctx = perf_swevent_get_recursion_context(); |
1235 | if (rctx < 0) | |
ce71b9df FW |
1236 | goto end_recursion; |
1237 | ||
a1a138d0 MH |
1238 | __cpu = smp_processor_id(); |
1239 | ||
1240 | if (in_nmi()) | |
444a2a3b | 1241 | trace_buf = rcu_dereference(perf_trace_buf_nmi); |
a1a138d0 | 1242 | else |
444a2a3b | 1243 | trace_buf = rcu_dereference(perf_trace_buf); |
a1a138d0 | 1244 | |
444a2a3b | 1245 | if (!trace_buf) |
a1a138d0 MH |
1246 | goto end; |
1247 | ||
ce71b9df | 1248 | raw_data = per_cpu_ptr(trace_buf, __cpu); |
444a2a3b | 1249 | |
a1a138d0 MH |
1250 | /* Zero dead bytes from alignment to avoid buffer leak to userspace */ |
1251 | *(u64 *)(&raw_data[size - sizeof(u64)]) = 0ULL; | |
1252 | entry = (struct kprobe_trace_entry *)raw_data; | |
1253 | ent = &entry->ent; | |
1254 | ||
1255 | tracing_generic_entry_update(ent, irq_flags, pc); | |
1256 | ent->type = call->id; | |
1257 | entry->nargs = tp->nr_args; | |
1258 | entry->ip = (unsigned long)kp->addr; | |
1259 | for (i = 0; i < tp->nr_args; i++) | |
1260 | entry->args[i] = call_fetch(&tp->args[i].fetch, regs); | |
1261 | perf_tp_event(call->id, entry->ip, 1, entry, size); | |
444a2a3b | 1262 | |
a1a138d0 | 1263 | end: |
4ed7c92d | 1264 | perf_swevent_put_recursion_context(rctx); |
ce71b9df | 1265 | end_recursion: |
a1a138d0 | 1266 | local_irq_restore(irq_flags); |
444a2a3b | 1267 | |
e08d1c65 MH |
1268 | return 0; |
1269 | } | |
1270 | ||
1271 | /* Kretprobe profile handler */ | |
1272 | static __kprobes int kretprobe_profile_func(struct kretprobe_instance *ri, | |
1273 | struct pt_regs *regs) | |
1274 | { | |
1275 | struct trace_probe *tp = container_of(ri->rp, struct trace_probe, rp); | |
1276 | struct ftrace_event_call *call = &tp->call; | |
1277 | struct kretprobe_trace_entry *entry; | |
a1a138d0 MH |
1278 | struct trace_entry *ent; |
1279 | int size, __size, i, pc, __cpu; | |
e08d1c65 | 1280 | unsigned long irq_flags; |
ce71b9df | 1281 | char *trace_buf; |
a1a138d0 | 1282 | char *raw_data; |
4ed7c92d | 1283 | int rctx; |
e08d1c65 | 1284 | |
e08d1c65 | 1285 | pc = preempt_count(); |
74ebb63e MH |
1286 | __size = SIZEOF_KRETPROBE_TRACE_ENTRY(tp->nr_args); |
1287 | size = ALIGN(__size + sizeof(u32), sizeof(u64)); | |
1288 | size -= sizeof(u32); | |
a1a138d0 MH |
1289 | if (WARN_ONCE(size > FTRACE_MAX_PROFILE_SIZE, |
1290 | "profile buffer not large enough")) | |
1291 | return 0; | |
1292 | ||
1293 | /* | |
1294 | * Protect the non nmi buffer | |
1295 | * This also protects the rcu read side | |
1296 | */ | |
1297 | local_irq_save(irq_flags); | |
ce71b9df | 1298 | |
4ed7c92d PZ |
1299 | rctx = perf_swevent_get_recursion_context(); |
1300 | if (rctx < 0) | |
ce71b9df FW |
1301 | goto end_recursion; |
1302 | ||
a1a138d0 MH |
1303 | __cpu = smp_processor_id(); |
1304 | ||
1305 | if (in_nmi()) | |
444a2a3b | 1306 | trace_buf = rcu_dereference(perf_trace_buf_nmi); |
a1a138d0 | 1307 | else |
444a2a3b | 1308 | trace_buf = rcu_dereference(perf_trace_buf); |
a1a138d0 | 1309 | |
444a2a3b | 1310 | if (!trace_buf) |
a1a138d0 MH |
1311 | goto end; |
1312 | ||
ce71b9df | 1313 | raw_data = per_cpu_ptr(trace_buf, __cpu); |
444a2a3b | 1314 | |
a1a138d0 MH |
1315 | /* Zero dead bytes from alignment to avoid buffer leak to userspace */ |
1316 | *(u64 *)(&raw_data[size - sizeof(u64)]) = 0ULL; | |
1317 | entry = (struct kretprobe_trace_entry *)raw_data; | |
1318 | ent = &entry->ent; | |
e08d1c65 | 1319 | |
a1a138d0 MH |
1320 | tracing_generic_entry_update(ent, irq_flags, pc); |
1321 | ent->type = call->id; | |
1322 | entry->nargs = tp->nr_args; | |
1323 | entry->func = (unsigned long)tp->rp.kp.addr; | |
1324 | entry->ret_ip = (unsigned long)ri->ret_addr; | |
1325 | for (i = 0; i < tp->nr_args; i++) | |
1326 | entry->args[i] = call_fetch(&tp->args[i].fetch, regs); | |
1327 | perf_tp_event(call->id, entry->ret_ip, 1, entry, size); | |
444a2a3b | 1328 | |
a1a138d0 | 1329 | end: |
4ed7c92d | 1330 | perf_swevent_put_recursion_context(rctx); |
ce71b9df | 1331 | end_recursion: |
a1a138d0 | 1332 | local_irq_restore(irq_flags); |
444a2a3b | 1333 | |
e08d1c65 MH |
1334 | return 0; |
1335 | } | |
1336 | ||
1337 | static int probe_profile_enable(struct ftrace_event_call *call) | |
1338 | { | |
1339 | struct trace_probe *tp = (struct trace_probe *)call->data; | |
1340 | ||
50d78056 | 1341 | tp->flags |= TP_FLAG_PROFILE; |
d7a4b414 | 1342 | |
50d78056 | 1343 | if (probe_is_return(tp)) |
e08d1c65 | 1344 | return enable_kretprobe(&tp->rp); |
50d78056 | 1345 | else |
e08d1c65 | 1346 | return enable_kprobe(&tp->rp.kp); |
e08d1c65 MH |
1347 | } |
1348 | ||
1349 | static void probe_profile_disable(struct ftrace_event_call *call) | |
1350 | { | |
50d78056 MH |
1351 | struct trace_probe *tp = (struct trace_probe *)call->data; |
1352 | ||
d7a4b414 | 1353 | tp->flags &= ~TP_FLAG_PROFILE; |
50d78056 | 1354 | |
d7a4b414 | 1355 | if (!(tp->flags & TP_FLAG_TRACE)) { |
50d78056 MH |
1356 | if (probe_is_return(tp)) |
1357 | disable_kretprobe(&tp->rp); | |
1358 | else | |
1359 | disable_kprobe(&tp->rp.kp); | |
1360 | } | |
e08d1c65 | 1361 | } |
50d78056 MH |
1362 | #endif /* CONFIG_EVENT_PROFILE */ |
1363 | ||
1364 | ||
1365 | static __kprobes | |
1366 | int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs) | |
1367 | { | |
1368 | struct trace_probe *tp = container_of(kp, struct trace_probe, rp.kp); | |
e08d1c65 | 1369 | |
50d78056 MH |
1370 | if (tp->flags & TP_FLAG_TRACE) |
1371 | kprobe_trace_func(kp, regs); | |
1372 | #ifdef CONFIG_EVENT_PROFILE | |
1373 | if (tp->flags & TP_FLAG_PROFILE) | |
1374 | kprobe_profile_func(kp, regs); | |
e08d1c65 | 1375 | #endif /* CONFIG_EVENT_PROFILE */ |
50d78056 MH |
1376 | return 0; /* We don't tweek kernel, so just return 0 */ |
1377 | } | |
1378 | ||
1379 | static __kprobes | |
1380 | int kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs) | |
1381 | { | |
1382 | struct trace_probe *tp = container_of(ri->rp, struct trace_probe, rp); | |
1383 | ||
1384 | if (tp->flags & TP_FLAG_TRACE) | |
1385 | kretprobe_trace_func(ri, regs); | |
1386 | #ifdef CONFIG_EVENT_PROFILE | |
1387 | if (tp->flags & TP_FLAG_PROFILE) | |
1388 | kretprobe_profile_func(ri, regs); | |
1389 | #endif /* CONFIG_EVENT_PROFILE */ | |
1390 | return 0; /* We don't tweek kernel, so just return 0 */ | |
1391 | } | |
e08d1c65 | 1392 | |
413d37d1 MH |
1393 | static int register_probe_event(struct trace_probe *tp) |
1394 | { | |
1395 | struct ftrace_event_call *call = &tp->call; | |
1396 | int ret; | |
1397 | ||
1398 | /* Initialize ftrace_event_call */ | |
413d37d1 | 1399 | if (probe_is_return(tp)) { |
ff50d991 | 1400 | tp->event.trace = print_kretprobe_event; |
413d37d1 MH |
1401 | call->raw_init = probe_event_raw_init; |
1402 | call->show_format = kretprobe_event_show_format; | |
1403 | call->define_fields = kretprobe_event_define_fields; | |
1404 | } else { | |
ff50d991 | 1405 | tp->event.trace = print_kprobe_event; |
413d37d1 MH |
1406 | call->raw_init = probe_event_raw_init; |
1407 | call->show_format = kprobe_event_show_format; | |
1408 | call->define_fields = kprobe_event_define_fields; | |
1409 | } | |
ff50d991 MH |
1410 | call->event = &tp->event; |
1411 | call->id = register_ftrace_event(&tp->event); | |
1412 | if (!call->id) | |
1413 | return -ENODEV; | |
5a0d9050 | 1414 | call->enabled = 0; |
413d37d1 MH |
1415 | call->regfunc = probe_event_enable; |
1416 | call->unregfunc = probe_event_disable; | |
e08d1c65 MH |
1417 | |
1418 | #ifdef CONFIG_EVENT_PROFILE | |
1419 | atomic_set(&call->profile_count, -1); | |
1420 | call->profile_enable = probe_profile_enable; | |
1421 | call->profile_disable = probe_profile_disable; | |
1422 | #endif | |
413d37d1 MH |
1423 | call->data = tp; |
1424 | ret = trace_add_event_call(call); | |
ff50d991 | 1425 | if (ret) { |
413d37d1 | 1426 | pr_info("Failed to register kprobe event: %s\n", call->name); |
ff50d991 MH |
1427 | unregister_ftrace_event(&tp->event); |
1428 | } | |
413d37d1 MH |
1429 | return ret; |
1430 | } | |
1431 | ||
1432 | static void unregister_probe_event(struct trace_probe *tp) | |
1433 | { | |
ff50d991 | 1434 | /* tp->event is unregistered in trace_remove_event_call() */ |
413d37d1 MH |
1435 | trace_remove_event_call(&tp->call); |
1436 | } | |
1437 | ||
1438 | /* Make a debugfs interface for controling probe points */ | |
1439 | static __init int init_kprobe_trace(void) | |
1440 | { | |
1441 | struct dentry *d_tracer; | |
1442 | struct dentry *entry; | |
413d37d1 MH |
1443 | |
1444 | d_tracer = tracing_init_dentry(); | |
1445 | if (!d_tracer) | |
1446 | return 0; | |
1447 | ||
1448 | entry = debugfs_create_file("kprobe_events", 0644, d_tracer, | |
1449 | NULL, &kprobe_events_ops); | |
1450 | ||
cd7e7bd5 | 1451 | /* Event list interface */ |
413d37d1 MH |
1452 | if (!entry) |
1453 | pr_warning("Could not create debugfs " | |
1454 | "'kprobe_events' entry\n"); | |
cd7e7bd5 MH |
1455 | |
1456 | /* Profile interface */ | |
1457 | entry = debugfs_create_file("kprobe_profile", 0444, d_tracer, | |
1458 | NULL, &kprobe_profile_ops); | |
1459 | ||
1460 | if (!entry) | |
1461 | pr_warning("Could not create debugfs " | |
1462 | "'kprobe_profile' entry\n"); | |
413d37d1 MH |
1463 | return 0; |
1464 | } | |
1465 | fs_initcall(init_kprobe_trace); | |
1466 | ||
1467 | ||
1468 | #ifdef CONFIG_FTRACE_STARTUP_TEST | |
1469 | ||
1470 | static int kprobe_trace_selftest_target(int a1, int a2, int a3, | |
1471 | int a4, int a5, int a6) | |
1472 | { | |
1473 | return a1 + a2 + a3 + a4 + a5 + a6; | |
1474 | } | |
1475 | ||
1476 | static __init int kprobe_trace_self_tests_init(void) | |
1477 | { | |
1478 | int ret; | |
1479 | int (*target)(int, int, int, int, int, int); | |
1480 | ||
1481 | target = kprobe_trace_selftest_target; | |
1482 | ||
1483 | pr_info("Testing kprobe tracing: "); | |
1484 | ||
1485 | ret = command_trace_probe("p:testprobe kprobe_trace_selftest_target " | |
f397af06 | 1486 | "$arg1 $arg2 $arg3 $arg4 $stack $stack0"); |
413d37d1 MH |
1487 | if (WARN_ON_ONCE(ret)) |
1488 | pr_warning("error enabling function entry\n"); | |
1489 | ||
1490 | ret = command_trace_probe("r:testprobe2 kprobe_trace_selftest_target " | |
f397af06 | 1491 | "$retval"); |
413d37d1 MH |
1492 | if (WARN_ON_ONCE(ret)) |
1493 | pr_warning("error enabling function return\n"); | |
1494 | ||
1495 | ret = target(1, 2, 3, 4, 5, 6); | |
1496 | ||
1497 | cleanup_all_probes(); | |
1498 | ||
1499 | pr_cont("OK\n"); | |
1500 | return 0; | |
1501 | } | |
1502 | ||
1503 | late_initcall(kprobe_trace_self_tests_init); | |
1504 | ||
1505 | #endif |