]>
Commit | Line | Data |
---|---|---|
413d37d1 MH |
1 | /* |
2 | * kprobe based kernel tracer | |
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> | |
e08d1c65 | 31 | #include <linux/perf_counter.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 MH |
40 | |
41 | /* currently, trace_kprobe only supports X86. */ | |
42 | ||
43 | struct fetch_func { | |
44 | unsigned long (*func)(struct pt_regs *, void *); | |
45 | void *data; | |
46 | }; | |
47 | ||
48 | static __kprobes unsigned long call_fetch(struct fetch_func *f, | |
49 | struct pt_regs *regs) | |
50 | { | |
51 | return f->func(regs, f->data); | |
52 | } | |
53 | ||
54 | /* fetch handlers */ | |
55 | static __kprobes unsigned long fetch_register(struct pt_regs *regs, | |
56 | void *offset) | |
57 | { | |
58 | return regs_get_register(regs, (unsigned int)((unsigned long)offset)); | |
59 | } | |
60 | ||
61 | static __kprobes unsigned long fetch_stack(struct pt_regs *regs, | |
62 | void *num) | |
63 | { | |
64 | return regs_get_kernel_stack_nth(regs, | |
65 | (unsigned int)((unsigned long)num)); | |
66 | } | |
67 | ||
68 | static __kprobes unsigned long fetch_memory(struct pt_regs *regs, void *addr) | |
69 | { | |
70 | unsigned long retval; | |
71 | ||
72 | if (probe_kernel_address(addr, retval)) | |
73 | return 0; | |
74 | return retval; | |
75 | } | |
76 | ||
77 | static __kprobes unsigned long fetch_argument(struct pt_regs *regs, void *num) | |
78 | { | |
79 | return regs_get_argument_nth(regs, (unsigned int)((unsigned long)num)); | |
80 | } | |
81 | ||
82 | static __kprobes unsigned long fetch_retvalue(struct pt_regs *regs, | |
83 | void *dummy) | |
84 | { | |
85 | return regs_return_value(regs); | |
86 | } | |
87 | ||
88 | static __kprobes unsigned long fetch_ip(struct pt_regs *regs, void *dummy) | |
89 | { | |
90 | return instruction_pointer(regs); | |
91 | } | |
92 | ||
93 | static __kprobes unsigned long fetch_stack_address(struct pt_regs *regs, | |
94 | void *dummy) | |
95 | { | |
96 | return kernel_stack_pointer(regs); | |
97 | } | |
98 | ||
99 | /* Memory fetching by symbol */ | |
100 | struct symbol_cache { | |
101 | char *symbol; | |
102 | long offset; | |
103 | unsigned long addr; | |
104 | }; | |
105 | ||
106 | static unsigned long update_symbol_cache(struct symbol_cache *sc) | |
107 | { | |
108 | sc->addr = (unsigned long)kallsyms_lookup_name(sc->symbol); | |
109 | if (sc->addr) | |
110 | sc->addr += sc->offset; | |
111 | return sc->addr; | |
112 | } | |
113 | ||
114 | static void free_symbol_cache(struct symbol_cache *sc) | |
115 | { | |
116 | kfree(sc->symbol); | |
117 | kfree(sc); | |
118 | } | |
119 | ||
120 | static struct symbol_cache *alloc_symbol_cache(const char *sym, long offset) | |
121 | { | |
122 | struct symbol_cache *sc; | |
123 | ||
124 | if (!sym || strlen(sym) == 0) | |
125 | return NULL; | |
126 | sc = kzalloc(sizeof(struct symbol_cache), GFP_KERNEL); | |
127 | if (!sc) | |
128 | return NULL; | |
129 | ||
130 | sc->symbol = kstrdup(sym, GFP_KERNEL); | |
131 | if (!sc->symbol) { | |
132 | kfree(sc); | |
133 | return NULL; | |
134 | } | |
135 | sc->offset = offset; | |
136 | ||
137 | update_symbol_cache(sc); | |
138 | return sc; | |
139 | } | |
140 | ||
141 | static __kprobes unsigned long fetch_symbol(struct pt_regs *regs, void *data) | |
142 | { | |
143 | struct symbol_cache *sc = data; | |
144 | ||
145 | if (sc->addr) | |
146 | return fetch_memory(regs, (void *)sc->addr); | |
147 | else | |
148 | return 0; | |
149 | } | |
150 | ||
151 | /* Special indirect memory access interface */ | |
152 | struct indirect_fetch_data { | |
153 | struct fetch_func orig; | |
154 | long offset; | |
155 | }; | |
156 | ||
157 | static __kprobes unsigned long fetch_indirect(struct pt_regs *regs, void *data) | |
158 | { | |
159 | struct indirect_fetch_data *ind = data; | |
160 | unsigned long addr; | |
161 | ||
162 | addr = call_fetch(&ind->orig, regs); | |
163 | if (addr) { | |
164 | addr += ind->offset; | |
165 | return fetch_memory(regs, (void *)addr); | |
166 | } else | |
167 | return 0; | |
168 | } | |
169 | ||
170 | static __kprobes void free_indirect_fetch_data(struct indirect_fetch_data *data) | |
171 | { | |
172 | if (data->orig.func == fetch_indirect) | |
173 | free_indirect_fetch_data(data->orig.data); | |
174 | else if (data->orig.func == fetch_symbol) | |
175 | free_symbol_cache(data->orig.data); | |
176 | kfree(data); | |
177 | } | |
178 | ||
179 | /** | |
eca0d916 | 180 | * Kprobe tracer core functions |
413d37d1 MH |
181 | */ |
182 | ||
eca0d916 MH |
183 | struct probe_arg { |
184 | struct fetch_func fetch; | |
185 | const char *name; | |
186 | }; | |
187 | ||
413d37d1 MH |
188 | struct trace_probe { |
189 | struct list_head list; | |
4a846b44 | 190 | struct kretprobe rp; /* Use rp.kp for kprobe use */ |
cd7e7bd5 | 191 | unsigned long nhit; |
413d37d1 | 192 | const char *symbol; /* symbol name */ |
413d37d1 | 193 | struct ftrace_event_call call; |
ff50d991 | 194 | struct trace_event event; |
a82378d8 | 195 | unsigned int nr_args; |
eca0d916 | 196 | struct probe_arg args[]; |
413d37d1 MH |
197 | }; |
198 | ||
a82378d8 MH |
199 | #define SIZEOF_TRACE_PROBE(n) \ |
200 | (offsetof(struct trace_probe, args) + \ | |
eca0d916 | 201 | (sizeof(struct probe_arg) * (n))) |
a82378d8 | 202 | |
413d37d1 MH |
203 | static int kprobe_trace_func(struct kprobe *kp, struct pt_regs *regs); |
204 | static int kretprobe_trace_func(struct kretprobe_instance *ri, | |
205 | struct pt_regs *regs); | |
206 | ||
207 | static __kprobes int probe_is_return(struct trace_probe *tp) | |
208 | { | |
4a846b44 | 209 | return tp->rp.handler != NULL; |
413d37d1 MH |
210 | } |
211 | ||
212 | static __kprobes const char *probe_symbol(struct trace_probe *tp) | |
213 | { | |
214 | return tp->symbol ? tp->symbol : "unknown"; | |
215 | } | |
216 | ||
30a7e073 | 217 | static int probe_arg_string(char *buf, size_t n, struct fetch_func *ff) |
413d37d1 MH |
218 | { |
219 | int ret = -EINVAL; | |
220 | ||
221 | if (ff->func == fetch_argument) | |
222 | ret = snprintf(buf, n, "a%lu", (unsigned long)ff->data); | |
223 | else if (ff->func == fetch_register) { | |
224 | const char *name; | |
225 | name = regs_query_register_name((unsigned int)((long)ff->data)); | |
226 | ret = snprintf(buf, n, "%%%s", name); | |
227 | } else if (ff->func == fetch_stack) | |
228 | ret = snprintf(buf, n, "s%lu", (unsigned long)ff->data); | |
229 | else if (ff->func == fetch_memory) | |
230 | ret = snprintf(buf, n, "@0x%p", ff->data); | |
231 | else if (ff->func == fetch_symbol) { | |
232 | struct symbol_cache *sc = ff->data; | |
233 | ret = snprintf(buf, n, "@%s%+ld", sc->symbol, sc->offset); | |
234 | } else if (ff->func == fetch_retvalue) | |
235 | ret = snprintf(buf, n, "rv"); | |
236 | else if (ff->func == fetch_ip) | |
237 | ret = snprintf(buf, n, "ra"); | |
238 | else if (ff->func == fetch_stack_address) | |
239 | ret = snprintf(buf, n, "sa"); | |
240 | else if (ff->func == fetch_indirect) { | |
241 | struct indirect_fetch_data *id = ff->data; | |
242 | size_t l = 0; | |
243 | ret = snprintf(buf, n, "%+ld(", id->offset); | |
244 | if (ret >= n) | |
245 | goto end; | |
246 | l += ret; | |
30a7e073 | 247 | ret = probe_arg_string(buf + l, n - l, &id->orig); |
413d37d1 MH |
248 | if (ret < 0) |
249 | goto end; | |
250 | l += ret; | |
251 | ret = snprintf(buf + l, n - l, ")"); | |
252 | ret += l; | |
253 | } | |
254 | end: | |
255 | if (ret >= n) | |
256 | return -ENOSPC; | |
257 | return ret; | |
258 | } | |
259 | ||
260 | static int register_probe_event(struct trace_probe *tp); | |
261 | static void unregister_probe_event(struct trace_probe *tp); | |
262 | ||
263 | static DEFINE_MUTEX(probe_lock); | |
264 | static LIST_HEAD(probe_list); | |
265 | ||
4a846b44 MH |
266 | /* |
267 | * Allocate new trace_probe and initialize it (including kprobes). | |
268 | */ | |
f52487e9 MH |
269 | static struct trace_probe *alloc_trace_probe(const char *group, |
270 | const char *event, | |
4a846b44 MH |
271 | void *addr, |
272 | const char *symbol, | |
273 | unsigned long offs, | |
274 | int nargs, int is_return) | |
413d37d1 MH |
275 | { |
276 | struct trace_probe *tp; | |
277 | ||
a82378d8 | 278 | tp = kzalloc(SIZEOF_TRACE_PROBE(nargs), GFP_KERNEL); |
413d37d1 MH |
279 | if (!tp) |
280 | return ERR_PTR(-ENOMEM); | |
281 | ||
282 | if (symbol) { | |
283 | tp->symbol = kstrdup(symbol, GFP_KERNEL); | |
284 | if (!tp->symbol) | |
285 | goto error; | |
4a846b44 MH |
286 | tp->rp.kp.symbol_name = tp->symbol; |
287 | tp->rp.kp.offset = offs; | |
288 | } else | |
289 | tp->rp.kp.addr = addr; | |
290 | ||
e08d1c65 | 291 | /* Set handler here for checking whether this probe is return or not. */ |
4a846b44 MH |
292 | if (is_return) |
293 | tp->rp.handler = kretprobe_trace_func; | |
294 | else | |
295 | tp->rp.kp.pre_handler = kprobe_trace_func; | |
296 | ||
4263565d MH |
297 | if (!event) |
298 | goto error; | |
299 | tp->call.name = kstrdup(event, GFP_KERNEL); | |
300 | if (!tp->call.name) | |
301 | goto error; | |
413d37d1 | 302 | |
f52487e9 MH |
303 | if (!group) |
304 | goto error; | |
305 | tp->call.system = kstrdup(group, GFP_KERNEL); | |
306 | if (!tp->call.system) | |
307 | goto error; | |
308 | ||
413d37d1 MH |
309 | INIT_LIST_HEAD(&tp->list); |
310 | return tp; | |
311 | error: | |
f52487e9 | 312 | kfree(tp->call.name); |
413d37d1 MH |
313 | kfree(tp->symbol); |
314 | kfree(tp); | |
315 | return ERR_PTR(-ENOMEM); | |
316 | } | |
317 | ||
eca0d916 MH |
318 | static void free_probe_arg(struct probe_arg *arg) |
319 | { | |
320 | if (arg->fetch.func == fetch_symbol) | |
321 | free_symbol_cache(arg->fetch.data); | |
322 | else if (arg->fetch.func == fetch_indirect) | |
323 | free_indirect_fetch_data(arg->fetch.data); | |
324 | kfree(arg->name); | |
325 | } | |
326 | ||
413d37d1 MH |
327 | static void free_trace_probe(struct trace_probe *tp) |
328 | { | |
329 | int i; | |
330 | ||
331 | for (i = 0; i < tp->nr_args; i++) | |
eca0d916 | 332 | free_probe_arg(&tp->args[i]); |
413d37d1 | 333 | |
f52487e9 | 334 | kfree(tp->call.system); |
413d37d1 MH |
335 | kfree(tp->call.name); |
336 | kfree(tp->symbol); | |
337 | kfree(tp); | |
338 | } | |
339 | ||
340 | static struct trace_probe *find_probe_event(const char *event) | |
341 | { | |
342 | struct trace_probe *tp; | |
343 | ||
344 | list_for_each_entry(tp, &probe_list, list) | |
4263565d | 345 | if (!strcmp(tp->call.name, event)) |
413d37d1 MH |
346 | return tp; |
347 | return NULL; | |
348 | } | |
349 | ||
350 | static void __unregister_trace_probe(struct trace_probe *tp) | |
351 | { | |
352 | if (probe_is_return(tp)) | |
353 | unregister_kretprobe(&tp->rp); | |
354 | else | |
4a846b44 | 355 | unregister_kprobe(&tp->rp.kp); |
413d37d1 MH |
356 | } |
357 | ||
358 | /* Unregister a trace_probe and probe_event: call with locking probe_lock */ | |
359 | static void unregister_trace_probe(struct trace_probe *tp) | |
360 | { | |
4263565d | 361 | unregister_probe_event(tp); |
413d37d1 MH |
362 | __unregister_trace_probe(tp); |
363 | list_del(&tp->list); | |
364 | } | |
365 | ||
366 | /* Register a trace_probe and probe_event */ | |
367 | static int register_trace_probe(struct trace_probe *tp) | |
368 | { | |
369 | struct trace_probe *old_tp; | |
370 | int ret; | |
371 | ||
372 | mutex_lock(&probe_lock); | |
373 | ||
374 | if (probe_is_return(tp)) | |
375 | ret = register_kretprobe(&tp->rp); | |
376 | else | |
4a846b44 | 377 | ret = register_kprobe(&tp->rp.kp); |
413d37d1 MH |
378 | |
379 | if (ret) { | |
380 | pr_warning("Could not insert probe(%d)\n", ret); | |
381 | if (ret == -EILSEQ) { | |
382 | pr_warning("Probing address(0x%p) is not an " | |
383 | "instruction boundary.\n", | |
4a846b44 | 384 | tp->rp.kp.addr); |
413d37d1 MH |
385 | ret = -EINVAL; |
386 | } | |
387 | goto end; | |
388 | } | |
389 | /* register as an event */ | |
4263565d MH |
390 | old_tp = find_probe_event(tp->call.name); |
391 | if (old_tp) { | |
392 | /* delete old event */ | |
393 | unregister_trace_probe(old_tp); | |
394 | free_trace_probe(old_tp); | |
395 | } | |
396 | ret = register_probe_event(tp); | |
397 | if (ret) { | |
398 | pr_warning("Faild to register probe event(%d)\n", ret); | |
399 | __unregister_trace_probe(tp); | |
413d37d1 MH |
400 | } |
401 | list_add_tail(&tp->list, &probe_list); | |
402 | end: | |
403 | mutex_unlock(&probe_lock); | |
404 | return ret; | |
405 | } | |
406 | ||
407 | /* Split symbol and offset. */ | |
2fba0c88 | 408 | static int split_symbol_offset(char *symbol, unsigned long *offset) |
413d37d1 MH |
409 | { |
410 | char *tmp; | |
411 | int ret; | |
412 | ||
413 | if (!offset) | |
414 | return -EINVAL; | |
415 | ||
416 | tmp = strchr(symbol, '+'); | |
413d37d1 MH |
417 | if (tmp) { |
418 | /* skip sign because strict_strtol doesn't accept '+' */ | |
2fba0c88 | 419 | ret = strict_strtoul(tmp + 1, 0, offset); |
413d37d1 MH |
420 | if (ret) |
421 | return ret; | |
413d37d1 MH |
422 | *tmp = '\0'; |
423 | } else | |
424 | *offset = 0; | |
425 | return 0; | |
426 | } | |
427 | ||
428 | #define PARAM_MAX_ARGS 16 | |
429 | #define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long)) | |
430 | ||
30a7e073 | 431 | static int parse_probe_arg(char *arg, struct fetch_func *ff, int is_return) |
413d37d1 MH |
432 | { |
433 | int ret = 0; | |
434 | unsigned long param; | |
435 | long offset; | |
436 | char *tmp; | |
437 | ||
438 | switch (arg[0]) { | |
439 | case 'a': /* argument */ | |
440 | ret = strict_strtoul(arg + 1, 10, ¶m); | |
441 | if (ret || param > PARAM_MAX_ARGS) | |
442 | ret = -EINVAL; | |
443 | else { | |
444 | ff->func = fetch_argument; | |
445 | ff->data = (void *)param; | |
446 | } | |
447 | break; | |
448 | case 'r': /* retval or retaddr */ | |
449 | if (is_return && arg[1] == 'v') { | |
450 | ff->func = fetch_retvalue; | |
451 | ff->data = NULL; | |
452 | } else if (is_return && arg[1] == 'a') { | |
453 | ff->func = fetch_ip; | |
454 | ff->data = NULL; | |
455 | } else | |
456 | ret = -EINVAL; | |
457 | break; | |
458 | case '%': /* named register */ | |
459 | ret = regs_query_register_offset(arg + 1); | |
460 | if (ret >= 0) { | |
461 | ff->func = fetch_register; | |
462 | ff->data = (void *)(unsigned long)ret; | |
463 | ret = 0; | |
464 | } | |
465 | break; | |
466 | case 's': /* stack */ | |
467 | if (arg[1] == 'a') { | |
468 | ff->func = fetch_stack_address; | |
469 | ff->data = NULL; | |
470 | } else { | |
471 | ret = strict_strtoul(arg + 1, 10, ¶m); | |
472 | if (ret || param > PARAM_MAX_STACK) | |
473 | ret = -EINVAL; | |
474 | else { | |
475 | ff->func = fetch_stack; | |
476 | ff->data = (void *)param; | |
477 | } | |
478 | } | |
479 | break; | |
480 | case '@': /* memory or symbol */ | |
481 | if (isdigit(arg[1])) { | |
482 | ret = strict_strtoul(arg + 1, 0, ¶m); | |
483 | if (ret) | |
484 | break; | |
485 | ff->func = fetch_memory; | |
486 | ff->data = (void *)param; | |
487 | } else { | |
488 | ret = split_symbol_offset(arg + 1, &offset); | |
489 | if (ret) | |
490 | break; | |
491 | ff->data = alloc_symbol_cache(arg + 1, | |
492 | offset); | |
493 | if (ff->data) | |
494 | ff->func = fetch_symbol; | |
495 | else | |
496 | ret = -EINVAL; | |
497 | } | |
498 | break; | |
499 | case '+': /* indirect memory */ | |
500 | case '-': | |
501 | tmp = strchr(arg, '('); | |
502 | if (!tmp) { | |
503 | ret = -EINVAL; | |
504 | break; | |
505 | } | |
506 | *tmp = '\0'; | |
507 | ret = strict_strtol(arg + 1, 0, &offset); | |
508 | if (ret) | |
509 | break; | |
510 | if (arg[0] == '-') | |
511 | offset = -offset; | |
512 | arg = tmp + 1; | |
513 | tmp = strrchr(arg, ')'); | |
514 | if (tmp) { | |
515 | struct indirect_fetch_data *id; | |
516 | *tmp = '\0'; | |
517 | id = kzalloc(sizeof(struct indirect_fetch_data), | |
518 | GFP_KERNEL); | |
519 | if (!id) | |
520 | return -ENOMEM; | |
521 | id->offset = offset; | |
30a7e073 | 522 | ret = parse_probe_arg(arg, &id->orig, is_return); |
413d37d1 MH |
523 | if (ret) |
524 | kfree(id); | |
525 | else { | |
526 | ff->func = fetch_indirect; | |
527 | ff->data = (void *)id; | |
528 | } | |
529 | } else | |
530 | ret = -EINVAL; | |
531 | break; | |
532 | default: | |
533 | /* TODO: support custom handler */ | |
534 | ret = -EINVAL; | |
535 | } | |
536 | return ret; | |
537 | } | |
538 | ||
539 | static int create_trace_probe(int argc, char **argv) | |
540 | { | |
541 | /* | |
542 | * Argument syntax: | |
f52487e9 MH |
543 | * - Add kprobe: p[:[GRP/]EVENT] KSYM[+OFFS]|KADDR [FETCHARGS] |
544 | * - Add kretprobe: r[:[GRP/]EVENT] KSYM[+0] [FETCHARGS] | |
413d37d1 MH |
545 | * Fetch args: |
546 | * aN : fetch Nth of function argument. (N:0-) | |
547 | * rv : fetch return value | |
548 | * ra : fetch return address | |
549 | * sa : fetch stack address | |
550 | * sN : fetch Nth of stack (N:0-) | |
551 | * @ADDR : fetch memory at ADDR (ADDR should be in kernel) | |
552 | * @SYM[+|-offs] : fetch memory at SYM +|- offs (SYM is a data symbol) | |
553 | * %REG : fetch register REG | |
554 | * Indirect memory fetch: | |
555 | * +|-offs(ARG) : fetch memory at ARG +|- offs address. | |
eca0d916 MH |
556 | * Alias name of args: |
557 | * NAME=FETCHARG : set NAME as alias of FETCHARG. | |
413d37d1 MH |
558 | */ |
559 | struct trace_probe *tp; | |
413d37d1 MH |
560 | int i, ret = 0; |
561 | int is_return = 0; | |
f52487e9 | 562 | char *symbol = NULL, *event = NULL, *arg = NULL, *group = NULL; |
2fba0c88 | 563 | unsigned long offset = 0; |
413d37d1 | 564 | void *addr = NULL; |
4a846b44 | 565 | char buf[MAX_EVENT_NAME_LEN]; |
413d37d1 MH |
566 | |
567 | if (argc < 2) | |
568 | return -EINVAL; | |
569 | ||
570 | if (argv[0][0] == 'p') | |
571 | is_return = 0; | |
572 | else if (argv[0][0] == 'r') | |
573 | is_return = 1; | |
574 | else | |
575 | return -EINVAL; | |
576 | ||
577 | if (argv[0][1] == ':') { | |
578 | event = &argv[0][2]; | |
f52487e9 MH |
579 | if (strchr(event, '/')) { |
580 | group = event; | |
581 | event = strchr(group, '/') + 1; | |
582 | event[-1] = '\0'; | |
583 | if (strlen(group) == 0) { | |
584 | pr_info("Group name is not specifiled\n"); | |
585 | return -EINVAL; | |
586 | } | |
587 | } | |
413d37d1 MH |
588 | if (strlen(event) == 0) { |
589 | pr_info("Event name is not specifiled\n"); | |
590 | return -EINVAL; | |
591 | } | |
592 | } | |
593 | ||
594 | if (isdigit(argv[1][0])) { | |
595 | if (is_return) | |
596 | return -EINVAL; | |
597 | /* an address specified */ | |
598 | ret = strict_strtoul(&argv[0][2], 0, (unsigned long *)&addr); | |
599 | if (ret) | |
600 | return ret; | |
601 | } else { | |
602 | /* a symbol specified */ | |
603 | symbol = argv[1]; | |
604 | /* TODO: support .init module functions */ | |
605 | ret = split_symbol_offset(symbol, &offset); | |
606 | if (ret) | |
607 | return ret; | |
608 | if (offset && is_return) | |
609 | return -EINVAL; | |
610 | } | |
a82378d8 | 611 | argc -= 2; argv += 2; |
413d37d1 MH |
612 | |
613 | /* setup a probe */ | |
f52487e9 MH |
614 | if (!group) |
615 | group = KPROBE_EVENT_SYSTEM; | |
4263565d MH |
616 | if (!event) { |
617 | /* Make a new event name */ | |
4263565d MH |
618 | if (symbol) |
619 | snprintf(buf, MAX_EVENT_NAME_LEN, "%c@%s%+ld", | |
620 | is_return ? 'r' : 'p', symbol, offset); | |
621 | else | |
622 | snprintf(buf, MAX_EVENT_NAME_LEN, "%c@0x%p", | |
623 | is_return ? 'r' : 'p', addr); | |
4a846b44 MH |
624 | event = buf; |
625 | } | |
f52487e9 MH |
626 | tp = alloc_trace_probe(group, event, addr, symbol, offset, argc, |
627 | is_return); | |
413d37d1 MH |
628 | if (IS_ERR(tp)) |
629 | return PTR_ERR(tp); | |
630 | ||
413d37d1 | 631 | /* parse arguments */ |
a82378d8 MH |
632 | ret = 0; |
633 | for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) { | |
eca0d916 MH |
634 | /* Parse argument name */ |
635 | arg = strchr(argv[i], '='); | |
636 | if (arg) | |
637 | *arg++ = '\0'; | |
638 | else | |
639 | arg = argv[i]; | |
640 | tp->args[i].name = kstrdup(argv[i], GFP_KERNEL); | |
641 | ||
642 | /* Parse fetch argument */ | |
643 | if (strlen(arg) > MAX_ARGSTR_LEN) { | |
644 | pr_info("Argument%d(%s) is too long.\n", i, arg); | |
413d37d1 MH |
645 | ret = -ENOSPC; |
646 | goto error; | |
647 | } | |
eca0d916 | 648 | ret = parse_probe_arg(arg, &tp->args[i].fetch, is_return); |
413d37d1 MH |
649 | if (ret) |
650 | goto error; | |
651 | } | |
652 | tp->nr_args = i; | |
653 | ||
654 | ret = register_trace_probe(tp); | |
655 | if (ret) | |
656 | goto error; | |
657 | return 0; | |
658 | ||
659 | error: | |
660 | free_trace_probe(tp); | |
661 | return ret; | |
662 | } | |
663 | ||
664 | static void cleanup_all_probes(void) | |
665 | { | |
666 | struct trace_probe *tp; | |
667 | ||
668 | mutex_lock(&probe_lock); | |
669 | /* TODO: Use batch unregistration */ | |
670 | while (!list_empty(&probe_list)) { | |
671 | tp = list_entry(probe_list.next, struct trace_probe, list); | |
672 | unregister_trace_probe(tp); | |
673 | free_trace_probe(tp); | |
674 | } | |
675 | mutex_unlock(&probe_lock); | |
676 | } | |
677 | ||
678 | ||
679 | /* Probes listing interfaces */ | |
680 | static void *probes_seq_start(struct seq_file *m, loff_t *pos) | |
681 | { | |
682 | mutex_lock(&probe_lock); | |
683 | return seq_list_start(&probe_list, *pos); | |
684 | } | |
685 | ||
686 | static void *probes_seq_next(struct seq_file *m, void *v, loff_t *pos) | |
687 | { | |
688 | return seq_list_next(v, &probe_list, pos); | |
689 | } | |
690 | ||
691 | static void probes_seq_stop(struct seq_file *m, void *v) | |
692 | { | |
693 | mutex_unlock(&probe_lock); | |
694 | } | |
695 | ||
696 | static int probes_seq_show(struct seq_file *m, void *v) | |
697 | { | |
698 | struct trace_probe *tp = v; | |
699 | int i, ret; | |
700 | char buf[MAX_ARGSTR_LEN + 1]; | |
701 | ||
702 | seq_printf(m, "%c", probe_is_return(tp) ? 'r' : 'p'); | |
4263565d | 703 | seq_printf(m, ":%s", tp->call.name); |
413d37d1 MH |
704 | |
705 | if (tp->symbol) | |
4a846b44 | 706 | seq_printf(m, " %s+%u", probe_symbol(tp), tp->rp.kp.offset); |
413d37d1 | 707 | else |
4a846b44 | 708 | seq_printf(m, " 0x%p", tp->rp.kp.addr); |
413d37d1 MH |
709 | |
710 | for (i = 0; i < tp->nr_args; i++) { | |
eca0d916 | 711 | ret = probe_arg_string(buf, MAX_ARGSTR_LEN, &tp->args[i].fetch); |
413d37d1 MH |
712 | if (ret < 0) { |
713 | pr_warning("Argument%d decoding error(%d).\n", i, ret); | |
714 | return ret; | |
715 | } | |
eca0d916 | 716 | seq_printf(m, " %s=%s", tp->args[i].name, buf); |
413d37d1 MH |
717 | } |
718 | seq_printf(m, "\n"); | |
719 | return 0; | |
720 | } | |
721 | ||
722 | static const struct seq_operations probes_seq_op = { | |
723 | .start = probes_seq_start, | |
724 | .next = probes_seq_next, | |
725 | .stop = probes_seq_stop, | |
726 | .show = probes_seq_show | |
727 | }; | |
728 | ||
729 | static int probes_open(struct inode *inode, struct file *file) | |
730 | { | |
731 | if ((file->f_mode & FMODE_WRITE) && | |
732 | (file->f_flags & O_TRUNC)) | |
733 | cleanup_all_probes(); | |
734 | ||
735 | return seq_open(file, &probes_seq_op); | |
736 | } | |
737 | ||
738 | static int command_trace_probe(const char *buf) | |
739 | { | |
740 | char **argv; | |
741 | int argc = 0, ret = 0; | |
742 | ||
743 | argv = argv_split(GFP_KERNEL, buf, &argc); | |
744 | if (!argv) | |
745 | return -ENOMEM; | |
746 | ||
747 | if (argc) | |
748 | ret = create_trace_probe(argc, argv); | |
749 | ||
750 | argv_free(argv); | |
751 | return ret; | |
752 | } | |
753 | ||
754 | #define WRITE_BUFSIZE 128 | |
755 | ||
756 | static ssize_t probes_write(struct file *file, const char __user *buffer, | |
757 | size_t count, loff_t *ppos) | |
758 | { | |
759 | char *kbuf, *tmp; | |
760 | int ret; | |
761 | size_t done; | |
762 | size_t size; | |
763 | ||
764 | kbuf = kmalloc(WRITE_BUFSIZE, GFP_KERNEL); | |
765 | if (!kbuf) | |
766 | return -ENOMEM; | |
767 | ||
768 | ret = done = 0; | |
769 | while (done < count) { | |
770 | size = count - done; | |
771 | if (size >= WRITE_BUFSIZE) | |
772 | size = WRITE_BUFSIZE - 1; | |
773 | if (copy_from_user(kbuf, buffer + done, size)) { | |
774 | ret = -EFAULT; | |
775 | goto out; | |
776 | } | |
777 | kbuf[size] = '\0'; | |
778 | tmp = strchr(kbuf, '\n'); | |
779 | if (tmp) { | |
780 | *tmp = '\0'; | |
781 | size = tmp - kbuf + 1; | |
782 | } else if (done + size < count) { | |
783 | pr_warning("Line length is too long: " | |
784 | "Should be less than %d.", WRITE_BUFSIZE); | |
785 | ret = -EINVAL; | |
786 | goto out; | |
787 | } | |
788 | done += size; | |
789 | /* Remove comments */ | |
790 | tmp = strchr(kbuf, '#'); | |
791 | if (tmp) | |
792 | *tmp = '\0'; | |
793 | ||
794 | ret = command_trace_probe(kbuf); | |
795 | if (ret) | |
796 | goto out; | |
797 | } | |
798 | ret = done; | |
799 | out: | |
800 | kfree(kbuf); | |
801 | return ret; | |
802 | } | |
803 | ||
804 | static const struct file_operations kprobe_events_ops = { | |
805 | .owner = THIS_MODULE, | |
806 | .open = probes_open, | |
807 | .read = seq_read, | |
808 | .llseek = seq_lseek, | |
809 | .release = seq_release, | |
810 | .write = probes_write, | |
811 | }; | |
812 | ||
cd7e7bd5 MH |
813 | /* Probes profiling interfaces */ |
814 | static int probes_profile_seq_show(struct seq_file *m, void *v) | |
815 | { | |
816 | struct trace_probe *tp = v; | |
817 | ||
818 | seq_printf(m, " %-44s %15lu %15lu\n", tp->call.name, tp->nhit, | |
4a846b44 | 819 | tp->rp.kp.nmissed); |
cd7e7bd5 MH |
820 | |
821 | return 0; | |
822 | } | |
823 | ||
824 | static const struct seq_operations profile_seq_op = { | |
825 | .start = probes_seq_start, | |
826 | .next = probes_seq_next, | |
827 | .stop = probes_seq_stop, | |
828 | .show = probes_profile_seq_show | |
829 | }; | |
830 | ||
831 | static int profile_open(struct inode *inode, struct file *file) | |
832 | { | |
833 | return seq_open(file, &profile_seq_op); | |
834 | } | |
835 | ||
836 | static const struct file_operations kprobe_profile_ops = { | |
837 | .owner = THIS_MODULE, | |
838 | .open = profile_open, | |
839 | .read = seq_read, | |
840 | .llseek = seq_lseek, | |
841 | .release = seq_release, | |
842 | }; | |
843 | ||
413d37d1 MH |
844 | /* Kprobe handler */ |
845 | static __kprobes int kprobe_trace_func(struct kprobe *kp, struct pt_regs *regs) | |
846 | { | |
4a846b44 | 847 | struct trace_probe *tp = container_of(kp, struct trace_probe, rp.kp); |
413d37d1 MH |
848 | struct kprobe_trace_entry *entry; |
849 | struct ring_buffer_event *event; | |
8f8ffe24 | 850 | struct ring_buffer *buffer; |
413d37d1 MH |
851 | int size, i, pc; |
852 | unsigned long irq_flags; | |
4263565d | 853 | struct ftrace_event_call *call = &tp->call; |
413d37d1 | 854 | |
cd7e7bd5 MH |
855 | tp->nhit++; |
856 | ||
413d37d1 MH |
857 | local_save_flags(irq_flags); |
858 | pc = preempt_count(); | |
859 | ||
860 | size = SIZEOF_KPROBE_TRACE_ENTRY(tp->nr_args); | |
861 | ||
8f8ffe24 | 862 | event = trace_current_buffer_lock_reserve(&buffer, call->id, size, |
413d37d1 MH |
863 | irq_flags, pc); |
864 | if (!event) | |
865 | return 0; | |
866 | ||
867 | entry = ring_buffer_event_data(event); | |
868 | entry->nargs = tp->nr_args; | |
869 | entry->ip = (unsigned long)kp->addr; | |
870 | for (i = 0; i < tp->nr_args; i++) | |
eca0d916 | 871 | entry->args[i] = call_fetch(&tp->args[i].fetch, regs); |
413d37d1 | 872 | |
8f8ffe24 FW |
873 | if (!filter_current_check_discard(buffer, call, entry, event)) |
874 | trace_nowake_buffer_unlock_commit(buffer, event, irq_flags, pc); | |
413d37d1 MH |
875 | return 0; |
876 | } | |
877 | ||
878 | /* Kretprobe handler */ | |
879 | static __kprobes int kretprobe_trace_func(struct kretprobe_instance *ri, | |
880 | struct pt_regs *regs) | |
881 | { | |
882 | struct trace_probe *tp = container_of(ri->rp, struct trace_probe, rp); | |
883 | struct kretprobe_trace_entry *entry; | |
884 | struct ring_buffer_event *event; | |
8f8ffe24 | 885 | struct ring_buffer *buffer; |
413d37d1 MH |
886 | int size, i, pc; |
887 | unsigned long irq_flags; | |
4263565d | 888 | struct ftrace_event_call *call = &tp->call; |
413d37d1 MH |
889 | |
890 | local_save_flags(irq_flags); | |
891 | pc = preempt_count(); | |
892 | ||
893 | size = SIZEOF_KRETPROBE_TRACE_ENTRY(tp->nr_args); | |
894 | ||
8f8ffe24 | 895 | event = trace_current_buffer_lock_reserve(&buffer, call->id, size, |
413d37d1 MH |
896 | irq_flags, pc); |
897 | if (!event) | |
898 | return 0; | |
899 | ||
900 | entry = ring_buffer_event_data(event); | |
901 | entry->nargs = tp->nr_args; | |
4a846b44 | 902 | entry->func = (unsigned long)tp->rp.kp.addr; |
413d37d1 MH |
903 | entry->ret_ip = (unsigned long)ri->ret_addr; |
904 | for (i = 0; i < tp->nr_args; i++) | |
eca0d916 | 905 | entry->args[i] = call_fetch(&tp->args[i].fetch, regs); |
413d37d1 | 906 | |
8f8ffe24 FW |
907 | if (!filter_current_check_discard(buffer, call, entry, event)) |
908 | trace_nowake_buffer_unlock_commit(buffer, event, irq_flags, pc); | |
413d37d1 MH |
909 | |
910 | return 0; | |
911 | } | |
912 | ||
913 | /* Event entry printers */ | |
914 | enum print_line_t | |
915 | print_kprobe_event(struct trace_iterator *iter, int flags) | |
916 | { | |
917 | struct kprobe_trace_entry *field; | |
918 | struct trace_seq *s = &iter->seq; | |
eca0d916 MH |
919 | struct trace_event *event; |
920 | struct trace_probe *tp; | |
413d37d1 MH |
921 | int i; |
922 | ||
ff50d991 | 923 | field = (struct kprobe_trace_entry *)iter->ent; |
eca0d916 MH |
924 | event = ftrace_find_event(field->ent.type); |
925 | tp = container_of(event, struct trace_probe, event); | |
413d37d1 | 926 | |
6e9f23d1 MH |
927 | if (!trace_seq_printf(s, "%s: (", tp->call.name)) |
928 | goto partial; | |
929 | ||
413d37d1 MH |
930 | if (!seq_print_ip_sym(s, field->ip, flags | TRACE_ITER_SYM_OFFSET)) |
931 | goto partial; | |
932 | ||
6e9f23d1 | 933 | if (!trace_seq_puts(s, ")")) |
413d37d1 MH |
934 | goto partial; |
935 | ||
936 | for (i = 0; i < field->nargs; i++) | |
eca0d916 MH |
937 | if (!trace_seq_printf(s, " %s=%lx", |
938 | tp->args[i].name, field->args[i])) | |
413d37d1 MH |
939 | goto partial; |
940 | ||
941 | if (!trace_seq_puts(s, "\n")) | |
942 | goto partial; | |
943 | ||
944 | return TRACE_TYPE_HANDLED; | |
945 | partial: | |
946 | return TRACE_TYPE_PARTIAL_LINE; | |
947 | } | |
948 | ||
949 | enum print_line_t | |
950 | print_kretprobe_event(struct trace_iterator *iter, int flags) | |
951 | { | |
952 | struct kretprobe_trace_entry *field; | |
953 | struct trace_seq *s = &iter->seq; | |
eca0d916 MH |
954 | struct trace_event *event; |
955 | struct trace_probe *tp; | |
413d37d1 MH |
956 | int i; |
957 | ||
ff50d991 | 958 | field = (struct kretprobe_trace_entry *)iter->ent; |
eca0d916 MH |
959 | event = ftrace_find_event(field->ent.type); |
960 | tp = container_of(event, struct trace_probe, event); | |
413d37d1 | 961 | |
6e9f23d1 MH |
962 | if (!trace_seq_printf(s, "%s: (", tp->call.name)) |
963 | goto partial; | |
964 | ||
413d37d1 MH |
965 | if (!seq_print_ip_sym(s, field->ret_ip, flags | TRACE_ITER_SYM_OFFSET)) |
966 | goto partial; | |
967 | ||
968 | if (!trace_seq_puts(s, " <- ")) | |
969 | goto partial; | |
970 | ||
971 | if (!seq_print_ip_sym(s, field->func, flags & ~TRACE_ITER_SYM_OFFSET)) | |
972 | goto partial; | |
973 | ||
6e9f23d1 | 974 | if (!trace_seq_puts(s, ")")) |
413d37d1 MH |
975 | goto partial; |
976 | ||
977 | for (i = 0; i < field->nargs; i++) | |
eca0d916 MH |
978 | if (!trace_seq_printf(s, " %s=%lx", |
979 | tp->args[i].name, field->args[i])) | |
413d37d1 MH |
980 | goto partial; |
981 | ||
982 | if (!trace_seq_puts(s, "\n")) | |
983 | goto partial; | |
984 | ||
985 | return TRACE_TYPE_HANDLED; | |
986 | partial: | |
987 | return TRACE_TYPE_PARTIAL_LINE; | |
988 | } | |
989 | ||
413d37d1 MH |
990 | static int probe_event_enable(struct ftrace_event_call *call) |
991 | { | |
992 | struct trace_probe *tp = (struct trace_probe *)call->data; | |
993 | ||
e08d1c65 MH |
994 | if (probe_is_return(tp)) { |
995 | tp->rp.handler = kretprobe_trace_func; | |
413d37d1 | 996 | return enable_kretprobe(&tp->rp); |
e08d1c65 MH |
997 | } else { |
998 | tp->rp.kp.pre_handler = kprobe_trace_func; | |
4a846b44 | 999 | return enable_kprobe(&tp->rp.kp); |
e08d1c65 | 1000 | } |
413d37d1 MH |
1001 | } |
1002 | ||
1003 | static void probe_event_disable(struct ftrace_event_call *call) | |
1004 | { | |
1005 | struct trace_probe *tp = (struct trace_probe *)call->data; | |
1006 | ||
1007 | if (probe_is_return(tp)) | |
1008 | disable_kretprobe(&tp->rp); | |
1009 | else | |
4a846b44 | 1010 | disable_kprobe(&tp->rp.kp); |
413d37d1 MH |
1011 | } |
1012 | ||
1013 | static int probe_event_raw_init(struct ftrace_event_call *event_call) | |
1014 | { | |
1015 | INIT_LIST_HEAD(&event_call->fields); | |
8f8ffe24 | 1016 | |
413d37d1 MH |
1017 | return 0; |
1018 | } | |
1019 | ||
1020 | #undef DEFINE_FIELD | |
1021 | #define DEFINE_FIELD(type, item, name, is_signed) \ | |
1022 | do { \ | |
1023 | ret = trace_define_field(event_call, #type, name, \ | |
1024 | offsetof(typeof(field), item), \ | |
1025 | sizeof(field.item), is_signed, \ | |
1026 | FILTER_OTHER); \ | |
1027 | if (ret) \ | |
1028 | return ret; \ | |
1029 | } while (0) | |
1030 | ||
1031 | static int kprobe_event_define_fields(struct ftrace_event_call *event_call) | |
1032 | { | |
1033 | int ret, i; | |
1034 | struct kprobe_trace_entry field; | |
413d37d1 MH |
1035 | struct trace_probe *tp = (struct trace_probe *)event_call->data; |
1036 | ||
1037 | ret = trace_define_common_fields(event_call); | |
1038 | if (!ret) | |
1039 | return ret; | |
1040 | ||
1041 | DEFINE_FIELD(unsigned long, ip, "ip", 0); | |
1042 | DEFINE_FIELD(int, nargs, "nargs", 1); | |
eca0d916 MH |
1043 | /* Set argument names as fields */ |
1044 | for (i = 0; i < tp->nr_args; i++) | |
1045 | DEFINE_FIELD(unsigned long, args[i], tp->args[i].name, 0); | |
413d37d1 MH |
1046 | return 0; |
1047 | } | |
1048 | ||
1049 | static int kretprobe_event_define_fields(struct ftrace_event_call *event_call) | |
1050 | { | |
1051 | int ret, i; | |
1052 | struct kretprobe_trace_entry field; | |
413d37d1 MH |
1053 | struct trace_probe *tp = (struct trace_probe *)event_call->data; |
1054 | ||
1055 | ret = trace_define_common_fields(event_call); | |
1056 | if (!ret) | |
1057 | return ret; | |
1058 | ||
1059 | DEFINE_FIELD(unsigned long, func, "func", 0); | |
1060 | DEFINE_FIELD(unsigned long, ret_ip, "ret_ip", 0); | |
1061 | DEFINE_FIELD(int, nargs, "nargs", 1); | |
eca0d916 MH |
1062 | /* Set argument names as fields */ |
1063 | for (i = 0; i < tp->nr_args; i++) | |
1064 | DEFINE_FIELD(unsigned long, args[i], tp->args[i].name, 0); | |
413d37d1 MH |
1065 | return 0; |
1066 | } | |
1067 | ||
1068 | static int __probe_event_show_format(struct trace_seq *s, | |
1069 | struct trace_probe *tp, const char *fmt, | |
1070 | const char *arg) | |
1071 | { | |
eca0d916 | 1072 | int i; |
413d37d1 | 1073 | |
413d37d1 MH |
1074 | /* Show format */ |
1075 | if (!trace_seq_printf(s, "\nprint fmt: \"%s", fmt)) | |
1076 | return 0; | |
1077 | ||
1078 | for (i = 0; i < tp->nr_args; i++) | |
eca0d916 | 1079 | if (!trace_seq_printf(s, " %s=%%lx", tp->args[i].name)) |
413d37d1 MH |
1080 | return 0; |
1081 | ||
1082 | if (!trace_seq_printf(s, "\", %s", arg)) | |
1083 | return 0; | |
1084 | ||
1085 | for (i = 0; i < tp->nr_args; i++) | |
eca0d916 | 1086 | if (!trace_seq_printf(s, ", REC->%s", tp->args[i].name)) |
413d37d1 MH |
1087 | return 0; |
1088 | ||
1089 | return trace_seq_puts(s, "\n"); | |
1090 | } | |
1091 | ||
1092 | #undef SHOW_FIELD | |
1093 | #define SHOW_FIELD(type, item, name) \ | |
1094 | do { \ | |
1095 | ret = trace_seq_printf(s, "\tfield: " #type " %s;\t" \ | |
38a47497 | 1096 | "offset:%u;\tsize:%u;\n", name, \ |
413d37d1 MH |
1097 | (unsigned int)offsetof(typeof(field), item),\ |
1098 | (unsigned int)sizeof(type)); \ | |
1099 | if (!ret) \ | |
1100 | return 0; \ | |
1101 | } while (0) | |
1102 | ||
1103 | static int kprobe_event_show_format(struct ftrace_event_call *call, | |
1104 | struct trace_seq *s) | |
1105 | { | |
1106 | struct kprobe_trace_entry field __attribute__((unused)); | |
1107 | int ret, i; | |
413d37d1 MH |
1108 | struct trace_probe *tp = (struct trace_probe *)call->data; |
1109 | ||
1110 | SHOW_FIELD(unsigned long, ip, "ip"); | |
1111 | SHOW_FIELD(int, nargs, "nargs"); | |
1112 | ||
1113 | /* Show fields */ | |
eca0d916 MH |
1114 | for (i = 0; i < tp->nr_args; i++) |
1115 | SHOW_FIELD(unsigned long, args[i], tp->args[i].name); | |
413d37d1 MH |
1116 | trace_seq_puts(s, "\n"); |
1117 | ||
6e9f23d1 | 1118 | return __probe_event_show_format(s, tp, "(%lx)", "REC->ip"); |
413d37d1 MH |
1119 | } |
1120 | ||
1121 | static int kretprobe_event_show_format(struct ftrace_event_call *call, | |
1122 | struct trace_seq *s) | |
1123 | { | |
1124 | struct kretprobe_trace_entry field __attribute__((unused)); | |
1125 | int ret, i; | |
413d37d1 MH |
1126 | struct trace_probe *tp = (struct trace_probe *)call->data; |
1127 | ||
1128 | SHOW_FIELD(unsigned long, func, "func"); | |
1129 | SHOW_FIELD(unsigned long, ret_ip, "ret_ip"); | |
1130 | SHOW_FIELD(int, nargs, "nargs"); | |
1131 | ||
1132 | /* Show fields */ | |
eca0d916 MH |
1133 | for (i = 0; i < tp->nr_args; i++) |
1134 | SHOW_FIELD(unsigned long, args[i], tp->args[i].name); | |
413d37d1 MH |
1135 | trace_seq_puts(s, "\n"); |
1136 | ||
6e9f23d1 MH |
1137 | return __probe_event_show_format(s, tp, "(%lx <- %lx)", |
1138 | "REC->func, REC->ret_ip"); | |
413d37d1 MH |
1139 | } |
1140 | ||
e08d1c65 MH |
1141 | #ifdef CONFIG_EVENT_PROFILE |
1142 | ||
1143 | /* Kprobe profile handler */ | |
1144 | static __kprobes int kprobe_profile_func(struct kprobe *kp, | |
1145 | struct pt_regs *regs) | |
1146 | { | |
1147 | struct trace_probe *tp = container_of(kp, struct trace_probe, rp.kp); | |
1148 | struct ftrace_event_call *call = &tp->call; | |
1149 | struct kprobe_trace_entry *entry; | |
1150 | int size, i, pc; | |
1151 | unsigned long irq_flags; | |
1152 | ||
1153 | local_save_flags(irq_flags); | |
1154 | pc = preempt_count(); | |
1155 | ||
1156 | size = SIZEOF_KPROBE_TRACE_ENTRY(tp->nr_args); | |
1157 | ||
1158 | do { | |
1159 | char raw_data[size]; | |
1160 | struct trace_entry *ent; | |
1161 | ||
1162 | *(u64 *)(&raw_data[size - sizeof(u64)]) = 0ULL; | |
1163 | entry = (struct kprobe_trace_entry *)raw_data; | |
1164 | ent = &entry->ent; | |
1165 | ||
1166 | tracing_generic_entry_update(ent, irq_flags, pc); | |
1167 | ent->type = call->id; | |
1168 | entry->nargs = tp->nr_args; | |
1169 | entry->ip = (unsigned long)kp->addr; | |
1170 | for (i = 0; i < tp->nr_args; i++) | |
eca0d916 | 1171 | entry->args[i] = call_fetch(&tp->args[i].fetch, regs); |
e08d1c65 MH |
1172 | perf_tpcounter_event(call->id, entry->ip, 1, entry, size); |
1173 | } while (0); | |
1174 | return 0; | |
1175 | } | |
1176 | ||
1177 | /* Kretprobe profile handler */ | |
1178 | static __kprobes int kretprobe_profile_func(struct kretprobe_instance *ri, | |
1179 | struct pt_regs *regs) | |
1180 | { | |
1181 | struct trace_probe *tp = container_of(ri->rp, struct trace_probe, rp); | |
1182 | struct ftrace_event_call *call = &tp->call; | |
1183 | struct kretprobe_trace_entry *entry; | |
1184 | int size, i, pc; | |
1185 | unsigned long irq_flags; | |
1186 | ||
1187 | local_save_flags(irq_flags); | |
1188 | pc = preempt_count(); | |
1189 | ||
1190 | size = SIZEOF_KRETPROBE_TRACE_ENTRY(tp->nr_args); | |
1191 | ||
1192 | do { | |
1193 | char raw_data[size]; | |
1194 | struct trace_entry *ent; | |
1195 | ||
1196 | *(u64 *)(&raw_data[size - sizeof(u64)]) = 0ULL; | |
1197 | entry = (struct kretprobe_trace_entry *)raw_data; | |
1198 | ent = &entry->ent; | |
1199 | ||
1200 | tracing_generic_entry_update(ent, irq_flags, pc); | |
1201 | ent->type = call->id; | |
1202 | entry->nargs = tp->nr_args; | |
1203 | entry->func = (unsigned long)tp->rp.kp.addr; | |
1204 | entry->ret_ip = (unsigned long)ri->ret_addr; | |
1205 | for (i = 0; i < tp->nr_args; i++) | |
eca0d916 | 1206 | entry->args[i] = call_fetch(&tp->args[i].fetch, regs); |
e08d1c65 MH |
1207 | perf_tpcounter_event(call->id, entry->ret_ip, 1, entry, size); |
1208 | } while (0); | |
1209 | return 0; | |
1210 | } | |
1211 | ||
1212 | static int probe_profile_enable(struct ftrace_event_call *call) | |
1213 | { | |
1214 | struct trace_probe *tp = (struct trace_probe *)call->data; | |
1215 | ||
1216 | if (atomic_inc_return(&call->profile_count)) | |
1217 | return 0; | |
1218 | ||
1219 | if (probe_is_return(tp)) { | |
1220 | tp->rp.handler = kretprobe_profile_func; | |
1221 | return enable_kretprobe(&tp->rp); | |
1222 | } else { | |
1223 | tp->rp.kp.pre_handler = kprobe_profile_func; | |
1224 | return enable_kprobe(&tp->rp.kp); | |
1225 | } | |
1226 | } | |
1227 | ||
1228 | static void probe_profile_disable(struct ftrace_event_call *call) | |
1229 | { | |
1230 | if (atomic_add_negative(-1, &call->profile_count)) | |
1231 | probe_event_disable(call); | |
1232 | } | |
1233 | ||
1234 | #endif /* CONFIG_EVENT_PROFILE */ | |
1235 | ||
413d37d1 MH |
1236 | static int register_probe_event(struct trace_probe *tp) |
1237 | { | |
1238 | struct ftrace_event_call *call = &tp->call; | |
1239 | int ret; | |
1240 | ||
1241 | /* Initialize ftrace_event_call */ | |
413d37d1 | 1242 | if (probe_is_return(tp)) { |
ff50d991 | 1243 | tp->event.trace = print_kretprobe_event; |
413d37d1 MH |
1244 | call->raw_init = probe_event_raw_init; |
1245 | call->show_format = kretprobe_event_show_format; | |
1246 | call->define_fields = kretprobe_event_define_fields; | |
1247 | } else { | |
ff50d991 | 1248 | tp->event.trace = print_kprobe_event; |
413d37d1 MH |
1249 | call->raw_init = probe_event_raw_init; |
1250 | call->show_format = kprobe_event_show_format; | |
1251 | call->define_fields = kprobe_event_define_fields; | |
1252 | } | |
ff50d991 MH |
1253 | call->event = &tp->event; |
1254 | call->id = register_ftrace_event(&tp->event); | |
1255 | if (!call->id) | |
1256 | return -ENODEV; | |
413d37d1 MH |
1257 | call->enabled = 1; |
1258 | call->regfunc = probe_event_enable; | |
1259 | call->unregfunc = probe_event_disable; | |
e08d1c65 MH |
1260 | |
1261 | #ifdef CONFIG_EVENT_PROFILE | |
1262 | atomic_set(&call->profile_count, -1); | |
1263 | call->profile_enable = probe_profile_enable; | |
1264 | call->profile_disable = probe_profile_disable; | |
1265 | #endif | |
413d37d1 MH |
1266 | call->data = tp; |
1267 | ret = trace_add_event_call(call); | |
ff50d991 | 1268 | if (ret) { |
413d37d1 | 1269 | pr_info("Failed to register kprobe event: %s\n", call->name); |
ff50d991 MH |
1270 | unregister_ftrace_event(&tp->event); |
1271 | } | |
413d37d1 MH |
1272 | return ret; |
1273 | } | |
1274 | ||
1275 | static void unregister_probe_event(struct trace_probe *tp) | |
1276 | { | |
ff50d991 | 1277 | /* tp->event is unregistered in trace_remove_event_call() */ |
413d37d1 MH |
1278 | trace_remove_event_call(&tp->call); |
1279 | } | |
1280 | ||
1281 | /* Make a debugfs interface for controling probe points */ | |
1282 | static __init int init_kprobe_trace(void) | |
1283 | { | |
1284 | struct dentry *d_tracer; | |
1285 | struct dentry *entry; | |
413d37d1 MH |
1286 | |
1287 | d_tracer = tracing_init_dentry(); | |
1288 | if (!d_tracer) | |
1289 | return 0; | |
1290 | ||
1291 | entry = debugfs_create_file("kprobe_events", 0644, d_tracer, | |
1292 | NULL, &kprobe_events_ops); | |
1293 | ||
cd7e7bd5 | 1294 | /* Event list interface */ |
413d37d1 MH |
1295 | if (!entry) |
1296 | pr_warning("Could not create debugfs " | |
1297 | "'kprobe_events' entry\n"); | |
cd7e7bd5 MH |
1298 | |
1299 | /* Profile interface */ | |
1300 | entry = debugfs_create_file("kprobe_profile", 0444, d_tracer, | |
1301 | NULL, &kprobe_profile_ops); | |
1302 | ||
1303 | if (!entry) | |
1304 | pr_warning("Could not create debugfs " | |
1305 | "'kprobe_profile' entry\n"); | |
413d37d1 MH |
1306 | return 0; |
1307 | } | |
1308 | fs_initcall(init_kprobe_trace); | |
1309 | ||
1310 | ||
1311 | #ifdef CONFIG_FTRACE_STARTUP_TEST | |
1312 | ||
1313 | static int kprobe_trace_selftest_target(int a1, int a2, int a3, | |
1314 | int a4, int a5, int a6) | |
1315 | { | |
1316 | return a1 + a2 + a3 + a4 + a5 + a6; | |
1317 | } | |
1318 | ||
1319 | static __init int kprobe_trace_self_tests_init(void) | |
1320 | { | |
1321 | int ret; | |
1322 | int (*target)(int, int, int, int, int, int); | |
1323 | ||
1324 | target = kprobe_trace_selftest_target; | |
1325 | ||
1326 | pr_info("Testing kprobe tracing: "); | |
1327 | ||
1328 | ret = command_trace_probe("p:testprobe kprobe_trace_selftest_target " | |
1329 | "a1 a2 a3 a4 a5 a6"); | |
1330 | if (WARN_ON_ONCE(ret)) | |
1331 | pr_warning("error enabling function entry\n"); | |
1332 | ||
1333 | ret = command_trace_probe("r:testprobe2 kprobe_trace_selftest_target " | |
1334 | "ra rv"); | |
1335 | if (WARN_ON_ONCE(ret)) | |
1336 | pr_warning("error enabling function return\n"); | |
1337 | ||
1338 | ret = target(1, 2, 3, 4, 5, 6); | |
1339 | ||
1340 | cleanup_all_probes(); | |
1341 | ||
1342 | pr_cont("OK\n"); | |
1343 | return 0; | |
1344 | } | |
1345 | ||
1346 | late_initcall(kprobe_trace_self_tests_init); | |
1347 | ||
1348 | #endif |