]> git.proxmox.com Git - mirror_ubuntu-artful-kernel.git/blob - kernel/trace/trace_kprobe.c
projects / mirror_ubuntu-artful-kernel.git / blob
? search:
summary | shortlog | log | commit | commitdiff | tree
blame | history | raw | HEAD
Merge tag 'efi-urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi into...
[mirror_ubuntu-artful-kernel.git] / kernel / trace / trace_kprobe.c
1 /*
2 * Kprobes-based tracing events
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 #define pr_fmt(fmt) "trace_kprobe: " fmt
20
21 #include <linux/module.h>
22 #include <linux/uaccess.h>
23 #include <linux/rculist.h>
24
25 #include "trace_probe.h"
26
27 #define KPROBE_EVENT_SYSTEM "kprobes"
28
29 /**
30 * Kprobe event core functions
31 */
32 struct trace_kprobe {
33 struct list_head list;
34 struct kretprobe rp; /* Use rp.kp for kprobe use */
35 unsigned long __percpu *nhit;
36 const char *symbol; /* symbol name */
37 struct trace_probe tp;
38 };
39
40 #define SIZEOF_TRACE_KPROBE(n) \
41 (offsetof(struct trace_kprobe, tp.args) + \
42 (sizeof(struct probe_arg) * (n)))
43
44
45 static nokprobe_inline bool trace_kprobe_is_return(struct trace_kprobe *tk)
46 {
47 return tk->rp.handler != NULL;
48 }
49
50 static nokprobe_inline const char *trace_kprobe_symbol(struct trace_kprobe *tk)
51 {
52 return tk->symbol ? tk->symbol : "unknown";
53 }
54
55 static nokprobe_inline unsigned long trace_kprobe_offset(struct trace_kprobe *tk)
56 {
57 return tk->rp.kp.offset;
58 }
59
60 static nokprobe_inline bool trace_kprobe_has_gone(struct trace_kprobe *tk)
61 {
62 return !!(kprobe_gone(&tk->rp.kp));
63 }
64
65 static nokprobe_inline bool trace_kprobe_within_module(struct trace_kprobe *tk,
66 struct module *mod)
67 {
68 int len = strlen(mod->name);
69 const char *name = trace_kprobe_symbol(tk);
70 return strncmp(mod->name, name, len) == 0 && name[len] == ':';
71 }
72
73 static nokprobe_inline bool trace_kprobe_is_on_module(struct trace_kprobe *tk)
74 {
75 return !!strchr(trace_kprobe_symbol(tk), ':');
76 }
77
78 static nokprobe_inline unsigned long trace_kprobe_nhit(struct trace_kprobe *tk)
79 {
80 unsigned long nhit = 0;
81 int cpu;
82
83 for_each_possible_cpu(cpu)
84 nhit += *per_cpu_ptr(tk->nhit, cpu);
85
86 return nhit;
87 }
88
89 static int register_kprobe_event(struct trace_kprobe *tk);
90 static int unregister_kprobe_event(struct trace_kprobe *tk);
91
92 static DEFINE_MUTEX(probe_lock);
93 static LIST_HEAD(probe_list);
94
95 static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs);
96 static int kretprobe_dispatcher(struct kretprobe_instance *ri,
97 struct pt_regs *regs);
98
99 /* Memory fetching by symbol */
100 struct symbol_cache {
101 char *symbol;
102 long offset;
103 unsigned long addr;
104 };
105
106 unsigned long update_symbol_cache(struct symbol_cache *sc)
107 {
108 sc->addr = (unsigned long)kallsyms_lookup_name(sc->symbol);
109
110 if (sc->addr)
111 sc->addr += sc->offset;
112
113 return sc->addr;
114 }
115
116 void free_symbol_cache(struct symbol_cache *sc)
117 {
118 kfree(sc->symbol);
119 kfree(sc);
120 }
121
122 struct symbol_cache *alloc_symbol_cache(const char *sym, long offset)
123 {
124 struct symbol_cache *sc;
125
126 if (!sym || strlen(sym) == 0)
127 return NULL;
128
129 sc = kzalloc(sizeof(struct symbol_cache), GFP_KERNEL);
130 if (!sc)
131 return NULL;
132
133 sc->symbol = kstrdup(sym, GFP_KERNEL);
134 if (!sc->symbol) {
135 kfree(sc);
136 return NULL;
137 }
138 sc->offset = offset;
139 update_symbol_cache(sc);
140
141 return sc;
142 }
143
144 /*
145 * Kprobes-specific fetch functions
146 */
147 #define DEFINE_FETCH_stack(type) \
148 static void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs, \
149 void *offset, void *dest) \
150 { \
151 *(type *)dest = (type)regs_get_kernel_stack_nth(regs, \
152 (unsigned int)((unsigned long)offset)); \
153 } \
154 NOKPROBE_SYMBOL(FETCH_FUNC_NAME(stack, type));
155
156 DEFINE_BASIC_FETCH_FUNCS(stack)
157 /* No string on the stack entry */
158 #define fetch_stack_string NULL
159 #define fetch_stack_string_size NULL
160
161 #define DEFINE_FETCH_memory(type) \
162 static void FETCH_FUNC_NAME(memory, type)(struct pt_regs *regs, \
163 void *addr, void *dest) \
164 { \
165 type retval; \
166 if (probe_kernel_address(addr, retval)) \
167 *(type *)dest = 0; \
168 else \
169 *(type *)dest = retval; \
170 } \
171 NOKPROBE_SYMBOL(FETCH_FUNC_NAME(memory, type));
172
173 DEFINE_BASIC_FETCH_FUNCS(memory)
174 /*
175 * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max
176 * length and relative data location.
177 */
178 static void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs,
179 void *addr, void *dest)
180 {
181 int maxlen = get_rloc_len(*(u32 *)dest);
182 u8 *dst = get_rloc_data(dest);
183 long ret;
184
185 if (!maxlen)
186 return;
187
188 /*
189 * Try to get string again, since the string can be changed while
190 * probing.
191 */
192 ret = strncpy_from_unsafe(dst, addr, maxlen);
193
194 if (ret < 0) { /* Failed to fetch string */
195 dst[0] = '\0';
196 *(u32 *)dest = make_data_rloc(0, get_rloc_offs(*(u32 *)dest));
197 } else {
198 *(u32 *)dest = make_data_rloc(ret, get_rloc_offs(*(u32 *)dest));
199 }
200 }
201 NOKPROBE_SYMBOL(FETCH_FUNC_NAME(memory, string));
202
203 /* Return the length of string -- including null terminal byte */
204 static void FETCH_FUNC_NAME(memory, string_size)(struct pt_regs *regs,
205 void *addr, void *dest)
206 {
207 mm_segment_t old_fs;
208 int ret, len = 0;
209 u8 c;
210
211 old_fs = get_fs();
212 set_fs(KERNEL_DS);
213 pagefault_disable();
214
215 do {
216 ret = __copy_from_user_inatomic(&c, (u8 *)addr + len, 1);
217 len++;
218 } while (c && ret == 0 && len < MAX_STRING_SIZE);
219
220 pagefault_enable();
221 set_fs(old_fs);
222
223 if (ret < 0) /* Failed to check the length */
224 *(u32 *)dest = 0;
225 else
226 *(u32 *)dest = len;
227 }
228 NOKPROBE_SYMBOL(FETCH_FUNC_NAME(memory, string_size));
229
230 #define DEFINE_FETCH_symbol(type) \
231 void FETCH_FUNC_NAME(symbol, type)(struct pt_regs *regs, void *data, void *dest)\
232 { \
233 struct symbol_cache *sc = data; \
234 if (sc->addr) \
235 fetch_memory_##type(regs, (void *)sc->addr, dest); \
236 else \
237 *(type *)dest = 0; \
238 } \
239 NOKPROBE_SYMBOL(FETCH_FUNC_NAME(symbol, type));
240
241 DEFINE_BASIC_FETCH_FUNCS(symbol)
242 DEFINE_FETCH_symbol(string)
243 DEFINE_FETCH_symbol(string_size)
244
245 /* kprobes don't support file_offset fetch methods */
246 #define fetch_file_offset_u8 NULL
247 #define fetch_file_offset_u16 NULL
248 #define fetch_file_offset_u32 NULL
249 #define fetch_file_offset_u64 NULL
250 #define fetch_file_offset_string NULL
251 #define fetch_file_offset_string_size NULL
252
253 /* Fetch type information table */
254 static const struct fetch_type kprobes_fetch_type_table[] = {
255 /* Special types */
256 [FETCH_TYPE_STRING] = __ASSIGN_FETCH_TYPE("string", string, string,
257 sizeof(u32), 1, "__data_loc char[]"),
258 [FETCH_TYPE_STRSIZE] = __ASSIGN_FETCH_TYPE("string_size", u32,
259 string_size, sizeof(u32), 0, "u32"),
260 /* Basic types */
261 ASSIGN_FETCH_TYPE(u8, u8, 0),
262 ASSIGN_FETCH_TYPE(u16, u16, 0),
263 ASSIGN_FETCH_TYPE(u32, u32, 0),
264 ASSIGN_FETCH_TYPE(u64, u64, 0),
265 ASSIGN_FETCH_TYPE(s8, u8, 1),
266 ASSIGN_FETCH_TYPE(s16, u16, 1),
267 ASSIGN_FETCH_TYPE(s32, u32, 1),
268 ASSIGN_FETCH_TYPE(s64, u64, 1),
269 ASSIGN_FETCH_TYPE_ALIAS(x8, u8, u8, 0),
270 ASSIGN_FETCH_TYPE_ALIAS(x16, u16, u16, 0),
271 ASSIGN_FETCH_TYPE_ALIAS(x32, u32, u32, 0),
272 ASSIGN_FETCH_TYPE_ALIAS(x64, u64, u64, 0),
273
274 ASSIGN_FETCH_TYPE_END
275 };
276
277 /*
278 * Allocate new trace_probe and initialize it (including kprobes).
279 */
280 static struct trace_kprobe *alloc_trace_kprobe(const char *group,
281 const char *event,
282 void *addr,
283 const char *symbol,
284 unsigned long offs,
285 int nargs, bool is_return)
286 {
287 struct trace_kprobe *tk;
288 int ret = -ENOMEM;
289
290 tk = kzalloc(SIZEOF_TRACE_KPROBE(nargs), GFP_KERNEL);
291 if (!tk)
292 return ERR_PTR(ret);
293
294 tk->nhit = alloc_percpu(unsigned long);
295 if (!tk->nhit)
296 goto error;
297
298 if (symbol) {
299 tk->symbol = kstrdup(symbol, GFP_KERNEL);
300 if (!tk->symbol)
301 goto error;
302 tk->rp.kp.symbol_name = tk->symbol;
303 tk->rp.kp.offset = offs;
304 } else
305 tk->rp.kp.addr = addr;
306
307 if (is_return)
308 tk->rp.handler = kretprobe_dispatcher;
309 else
310 tk->rp.kp.pre_handler = kprobe_dispatcher;
311
312 if (!event || !is_good_name(event)) {
313 ret = -EINVAL;
314 goto error;
315 }
316
317 tk->tp.call.class = &tk->tp.class;
318 tk->tp.call.name = kstrdup(event, GFP_KERNEL);
319 if (!tk->tp.call.name)
320 goto error;
321
322 if (!group || !is_good_name(group)) {
323 ret = -EINVAL;
324 goto error;
325 }
326
327 tk->tp.class.system = kstrdup(group, GFP_KERNEL);
328 if (!tk->tp.class.system)
329 goto error;
330
331 INIT_LIST_HEAD(&tk->list);
332 INIT_LIST_HEAD(&tk->tp.files);
333 return tk;
334 error:
335 kfree(tk->tp.call.name);
336 kfree(tk->symbol);
337 free_percpu(tk->nhit);
338 kfree(tk);
339 return ERR_PTR(ret);
340 }
341
342 static void free_trace_kprobe(struct trace_kprobe *tk)
343 {
344 int i;
345
346 for (i = 0; i < tk->tp.nr_args; i++)
347 traceprobe_free_probe_arg(&tk->tp.args[i]);
348
349 kfree(tk->tp.call.class->system);
350 kfree(tk->tp.call.name);
351 kfree(tk->symbol);
352 free_percpu(tk->nhit);
353 kfree(tk);
354 }
355
356 static struct trace_kprobe *find_trace_kprobe(const char *event,
357 const char *group)
358 {
359 struct trace_kprobe *tk;
360
361 list_for_each_entry(tk, &probe_list, list)
362 if (strcmp(trace_event_name(&tk->tp.call), event) == 0 &&
363 strcmp(tk->tp.call.class->system, group) == 0)
364 return tk;
365 return NULL;
366 }
367
368 /*
369 * Enable trace_probe
370 * if the file is NULL, enable "perf" handler, or enable "trace" handler.
371 */
372 static int
373 enable_trace_kprobe(struct trace_kprobe *tk, struct trace_event_file *file)
374 {
375 int ret = 0;
376
377 if (file) {
378 struct event_file_link *link;
379
380 link = kmalloc(sizeof(*link), GFP_KERNEL);
381 if (!link) {
382 ret = -ENOMEM;
383 goto out;
384 }
385
386 link->file = file;
387 list_add_tail_rcu(&link->list, &tk->tp.files);
388
389 tk->tp.flags |= TP_FLAG_TRACE;
390 } else
391 tk->tp.flags |= TP_FLAG_PROFILE;
392
393 if (trace_probe_is_registered(&tk->tp) && !trace_kprobe_has_gone(tk)) {
394 if (trace_kprobe_is_return(tk))
395 ret = enable_kretprobe(&tk->rp);
396 else
397 ret = enable_kprobe(&tk->rp.kp);
398 }
399 out:
400 return ret;
401 }
402
403 /*
404 * Disable trace_probe
405 * if the file is NULL, disable "perf" handler, or disable "trace" handler.
406 */
407 static int
408 disable_trace_kprobe(struct trace_kprobe *tk, struct trace_event_file *file)
409 {
410 struct event_file_link *link = NULL;
411 int wait = 0;
412 int ret = 0;
413
414 if (file) {
415 link = find_event_file_link(&tk->tp, file);
416 if (!link) {
417 ret = -EINVAL;
418 goto out;
419 }
420
421 list_del_rcu(&link->list);
422 wait = 1;
423 if (!list_empty(&tk->tp.files))
424 goto out;
425
426 tk->tp.flags &= ~TP_FLAG_TRACE;
427 } else
428 tk->tp.flags &= ~TP_FLAG_PROFILE;
429
430 if (!trace_probe_is_enabled(&tk->tp) && trace_probe_is_registered(&tk->tp)) {
431 if (trace_kprobe_is_return(tk))
432 disable_kretprobe(&tk->rp);
433 else
434 disable_kprobe(&tk->rp.kp);
435 wait = 1;
436 }
437 out:
438 if (wait) {
439 /*
440 * Synchronize with kprobe_trace_func/kretprobe_trace_func
441 * to ensure disabled (all running handlers are finished).
442 * This is not only for kfree(), but also the caller,
443 * trace_remove_event_call() supposes it for releasing
444 * event_call related objects, which will be accessed in
445 * the kprobe_trace_func/kretprobe_trace_func.
446 */
447 synchronize_sched();
448 kfree(link); /* Ignored if link == NULL */
449 }
450
451 return ret;
452 }
453
454 /* Internal register function - just handle k*probes and flags */
455 static int __register_trace_kprobe(struct trace_kprobe *tk)
456 {
457 int i, ret;
458
459 if (trace_probe_is_registered(&tk->tp))
460 return -EINVAL;
461
462 for (i = 0; i < tk->tp.nr_args; i++)
463 traceprobe_update_arg(&tk->tp.args[i]);
464
465 /* Set/clear disabled flag according to tp->flag */
466 if (trace_probe_is_enabled(&tk->tp))
467 tk->rp.kp.flags &= ~KPROBE_FLAG_DISABLED;
468 else
469 tk->rp.kp.flags |= KPROBE_FLAG_DISABLED;
470
471 if (trace_kprobe_is_return(tk))
472 ret = register_kretprobe(&tk->rp);
473 else
474 ret = register_kprobe(&tk->rp.kp);
475
476 if (ret == 0)
477 tk->tp.flags |= TP_FLAG_REGISTERED;
478 else {
479 pr_warn("Could not insert probe at %s+%lu: %d\n",
480 trace_kprobe_symbol(tk), trace_kprobe_offset(tk), ret);
481 if (ret == -ENOENT && trace_kprobe_is_on_module(tk)) {
482 pr_warn("This probe might be able to register after target module is loaded. Continue.\n");
483 ret = 0;
484 } else if (ret == -EILSEQ) {
485 pr_warn("Probing address(0x%p) is not an instruction boundary.\n",
486 tk->rp.kp.addr);
487 ret = -EINVAL;
488 }
489 }
490
491 return ret;
492 }
493
494 /* Internal unregister function - just handle k*probes and flags */
495 static void __unregister_trace_kprobe(struct trace_kprobe *tk)
496 {
497 if (trace_probe_is_registered(&tk->tp)) {
498 if (trace_kprobe_is_return(tk))
499 unregister_kretprobe(&tk->rp);
500 else
501 unregister_kprobe(&tk->rp.kp);
502 tk->tp.flags &= ~TP_FLAG_REGISTERED;
503 /* Cleanup kprobe for reuse */
504 if (tk->rp.kp.symbol_name)
505 tk->rp.kp.addr = NULL;
506 }
507 }
508
509 /* Unregister a trace_probe and probe_event: call with locking probe_lock */
510 static int unregister_trace_kprobe(struct trace_kprobe *tk)
511 {
512 /* Enabled event can not be unregistered */
513 if (trace_probe_is_enabled(&tk->tp))
514 return -EBUSY;
515
516 /* Will fail if probe is being used by ftrace or perf */
517 if (unregister_kprobe_event(tk))
518 return -EBUSY;
519
520 __unregister_trace_kprobe(tk);
521 list_del(&tk->list);
522
523 return 0;
524 }
525
526 /* Register a trace_probe and probe_event */
527 static int register_trace_kprobe(struct trace_kprobe *tk)
528 {
529 struct trace_kprobe *old_tk;
530 int ret;
531
532 mutex_lock(&probe_lock);
533
534 /* Delete old (same name) event if exist */
535 old_tk = find_trace_kprobe(trace_event_name(&tk->tp.call),
536 tk->tp.call.class->system);
537 if (old_tk) {
538 ret = unregister_trace_kprobe(old_tk);
539 if (ret < 0)
540 goto end;
541 free_trace_kprobe(old_tk);
542 }
543
544 /* Register new event */
545 ret = register_kprobe_event(tk);
546 if (ret) {
547 pr_warn("Failed to register probe event(%d)\n", ret);
548 goto end;
549 }
550
551 /* Register k*probe */
552 ret = __register_trace_kprobe(tk);
553 if (ret < 0)
554 unregister_kprobe_event(tk);
555 else
556 list_add_tail(&tk->list, &probe_list);
557
558 end:
559 mutex_unlock(&probe_lock);
560 return ret;
561 }
562
563 /* Module notifier call back, checking event on the module */
564 static int trace_kprobe_module_callback(struct notifier_block *nb,
565 unsigned long val, void *data)
566 {
567 struct module *mod = data;
568 struct trace_kprobe *tk;
569 int ret;
570
571 if (val != MODULE_STATE_COMING)
572 return NOTIFY_DONE;
573
574 /* Update probes on coming module */
575 mutex_lock(&probe_lock);
576 list_for_each_entry(tk, &probe_list, list) {
577 if (trace_kprobe_within_module(tk, mod)) {
578 /* Don't need to check busy - this should have gone. */
579 __unregister_trace_kprobe(tk);
580 ret = __register_trace_kprobe(tk);
581 if (ret)
582 pr_warn("Failed to re-register probe %s on %s: %d\n",
583 trace_event_name(&tk->tp.call),
584 mod->name, ret);
585 }
586 }
587 mutex_unlock(&probe_lock);
588
589 return NOTIFY_DONE;
590 }
591
592 static struct notifier_block trace_kprobe_module_nb = {
593 .notifier_call = trace_kprobe_module_callback,
594 .priority = 1 /* Invoked after kprobe module callback */
595 };
596
597 static int create_trace_kprobe(int argc, char **argv)
598 {
599 /*
600 * Argument syntax:
601 * - Add kprobe: p[:[GRP/]EVENT] [MOD:]KSYM[+OFFS]|KADDR [FETCHARGS]
602 * - Add kretprobe: r[:[GRP/]EVENT] [MOD:]KSYM[+0] [FETCHARGS]
603 * Fetch args:
604 * $retval : fetch return value
605 * $stack : fetch stack address
606 * $stackN : fetch Nth of stack (N:0-)
607 * $comm : fetch current task comm
608 * @ADDR : fetch memory at ADDR (ADDR should be in kernel)
609 * @SYM[+|-offs] : fetch memory at SYM +|- offs (SYM is a data symbol)
610 * %REG : fetch register REG
611 * Dereferencing memory fetch:
612 * +|-offs(ARG) : fetch memory at ARG +|- offs address.
613 * Alias name of args:
614 * NAME=FETCHARG : set NAME as alias of FETCHARG.
615 * Type of args:
616 * FETCHARG:TYPE : use TYPE instead of unsigned long.
617 */
618 struct trace_kprobe *tk;
619 int i, ret = 0;
620 bool is_return = false, is_delete = false;
621 char *symbol = NULL, *event = NULL, *group = NULL;
622 char *arg;
623 unsigned long offset = 0;
624 void *addr = NULL;
625 char buf[MAX_EVENT_NAME_LEN];
626
627 /* argc must be >= 1 */
628 if (argv[0][0] == 'p')
629 is_return = false;
630 else if (argv[0][0] == 'r')
631 is_return = true;
632 else if (argv[0][0] == '-')
633 is_delete = true;
634 else {
635 pr_info("Probe definition must be started with 'p', 'r' or"
636 " '-'.\n");
637 return -EINVAL;
638 }
639
640 if (argv[0][1] == ':') {
641 event = &argv[0][2];
642 if (strchr(event, '/')) {
643 group = event;
644 event = strchr(group, '/') + 1;
645 event[-1] = '\0';
646 if (strlen(group) == 0) {
647 pr_info("Group name is not specified\n");
648 return -EINVAL;
649 }
650 }
651 if (strlen(event) == 0) {
652 pr_info("Event name is not specified\n");
653 return -EINVAL;
654 }
655 }
656 if (!group)
657 group = KPROBE_EVENT_SYSTEM;
658
659 if (is_delete) {
660 if (!event) {
661 pr_info("Delete command needs an event name.\n");
662 return -EINVAL;
663 }
664 mutex_lock(&probe_lock);
665 tk = find_trace_kprobe(event, group);
666 if (!tk) {
667 mutex_unlock(&probe_lock);
668 pr_info("Event %s/%s doesn't exist.\n", group, event);
669 return -ENOENT;
670 }
671 /* delete an event */
672 ret = unregister_trace_kprobe(tk);
673 if (ret == 0)
674 free_trace_kprobe(tk);
675 mutex_unlock(&probe_lock);
676 return ret;
677 }
678
679 if (argc < 2) {
680 pr_info("Probe point is not specified.\n");
681 return -EINVAL;
682 }
683 if (isdigit(argv[1][0])) {
684 if (is_return) {
685 pr_info("Return probe point must be a symbol.\n");
686 return -EINVAL;
687 }
688 /* an address specified */
689 ret = kstrtoul(&argv[1][0], 0, (unsigned long *)&addr);
690 if (ret) {
691 pr_info("Failed to parse address.\n");
692 return ret;
693 }
694 } else {
695 /* a symbol specified */
696 symbol = argv[1];
697 /* TODO: support .init module functions */
698 ret = traceprobe_split_symbol_offset(symbol, &offset);
699 if (ret) {
700 pr_info("Failed to parse symbol.\n");
701 return ret;
702 }
703 if (offset && is_return) {
704 pr_info("Return probe must be used without offset.\n");
705 return -EINVAL;
706 }
707 }
708 argc -= 2; argv += 2;
709
710 /* setup a probe */
711 if (!event) {
712 /* Make a new event name */
713 if (symbol)
714 snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_%ld",
715 is_return ? 'r' : 'p', symbol, offset);
716 else
717 snprintf(buf, MAX_EVENT_NAME_LEN, "%c_0x%p",
718 is_return ? 'r' : 'p', addr);
719 event = buf;
720 }
721 tk = alloc_trace_kprobe(group, event, addr, symbol, offset, argc,
722 is_return);
723 if (IS_ERR(tk)) {
724 pr_info("Failed to allocate trace_probe.(%d)\n",
725 (int)PTR_ERR(tk));
726 return PTR_ERR(tk);
727 }
728
729 /* parse arguments */
730 ret = 0;
731 for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) {
732 struct probe_arg *parg = &tk->tp.args[i];
733
734 /* Increment count for freeing args in error case */
735 tk->tp.nr_args++;
736
737 /* Parse argument name */
738 arg = strchr(argv[i], '=');
739 if (arg) {
740 *arg++ = '\0';
741 parg->name = kstrdup(argv[i], GFP_KERNEL);
742 } else {
743 arg = argv[i];
744 /* If argument name is omitted, set "argN" */
745 snprintf(buf, MAX_EVENT_NAME_LEN, "arg%d", i + 1);
746 parg->name = kstrdup(buf, GFP_KERNEL);
747 }
748
749 if (!parg->name) {
750 pr_info("Failed to allocate argument[%d] name.\n", i);
751 ret = -ENOMEM;
752 goto error;
753 }
754
755 if (!is_good_name(parg->name)) {
756 pr_info("Invalid argument[%d] name: %s\n",
757 i, parg->name);
758 ret = -EINVAL;
759 goto error;
760 }
761
762 if (traceprobe_conflict_field_name(parg->name,
763 tk->tp.args, i)) {
764 pr_info("Argument[%d] name '%s' conflicts with "
765 "another field.\n", i, argv[i]);
766 ret = -EINVAL;
767 goto error;
768 }
769
770 /* Parse fetch argument */
771 ret = traceprobe_parse_probe_arg(arg, &tk->tp.size, parg,
772 is_return, true,
773 kprobes_fetch_type_table);
774 if (ret) {
775 pr_info("Parse error at argument[%d]. (%d)\n", i, ret);
776 goto error;
777 }
778 }
779
780 ret = register_trace_kprobe(tk);
781 if (ret)
782 goto error;
783 return 0;
784
785 error:
786 free_trace_kprobe(tk);
787 return ret;
788 }
789
790 static int release_all_trace_kprobes(void)
791 {
792 struct trace_kprobe *tk;
793 int ret = 0;
794
795 mutex_lock(&probe_lock);
796 /* Ensure no probe is in use. */
797 list_for_each_entry(tk, &probe_list, list)
798 if (trace_probe_is_enabled(&tk->tp)) {
799 ret = -EBUSY;
800 goto end;
801 }
802 /* TODO: Use batch unregistration */
803 while (!list_empty(&probe_list)) {
804 tk = list_entry(probe_list.next, struct trace_kprobe, list);
805 ret = unregister_trace_kprobe(tk);
806 if (ret)
807 goto end;
808 free_trace_kprobe(tk);
809 }
810
811 end:
812 mutex_unlock(&probe_lock);
813
814 return ret;
815 }
816
817 /* Probes listing interfaces */
818 static void *probes_seq_start(struct seq_file *m, loff_t *pos)
819 {
820 mutex_lock(&probe_lock);
821 return seq_list_start(&probe_list, *pos);
822 }
823
824 static void *probes_seq_next(struct seq_file *m, void *v, loff_t *pos)
825 {
826 return seq_list_next(v, &probe_list, pos);
827 }
828
829 static void probes_seq_stop(struct seq_file *m, void *v)
830 {
831 mutex_unlock(&probe_lock);
832 }
833
834 static int probes_seq_show(struct seq_file *m, void *v)
835 {
836 struct trace_kprobe *tk = v;
837 int i;
838
839 seq_putc(m, trace_kprobe_is_return(tk) ? 'r' : 'p');
840 seq_printf(m, ":%s/%s", tk->tp.call.class->system,
841 trace_event_name(&tk->tp.call));
842
843 if (!tk->symbol)
844 seq_printf(m, " 0x%p", tk->rp.kp.addr);
845 else if (tk->rp.kp.offset)
846 seq_printf(m, " %s+%u", trace_kprobe_symbol(tk),
847 tk->rp.kp.offset);
848 else
849 seq_printf(m, " %s", trace_kprobe_symbol(tk));
850
851 for (i = 0; i < tk->tp.nr_args; i++)
852 seq_printf(m, " %s=%s", tk->tp.args[i].name, tk->tp.args[i].comm);
853 seq_putc(m, '\n');
854
855 return 0;
856 }
857
858 static const struct seq_operations probes_seq_op = {
859 .start = probes_seq_start,
860 .next = probes_seq_next,
861 .stop = probes_seq_stop,
862 .show = probes_seq_show
863 };
864
865 static int probes_open(struct inode *inode, struct file *file)
866 {
867 int ret;
868
869 if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
870 ret = release_all_trace_kprobes();
871 if (ret < 0)
872 return ret;
873 }
874
875 return seq_open(file, &probes_seq_op);
876 }
877
878 static ssize_t probes_write(struct file *file, const char __user *buffer,
879 size_t count, loff_t *ppos)
880 {
881 return traceprobe_probes_write(file, buffer, count, ppos,
882 create_trace_kprobe);
883 }
884
885 static const struct file_operations kprobe_events_ops = {
886 .owner = THIS_MODULE,
887 .open = probes_open,
888 .read = seq_read,
889 .llseek = seq_lseek,
890 .release = seq_release,
891 .write = probes_write,
892 };
893
894 /* Probes profiling interfaces */
895 static int probes_profile_seq_show(struct seq_file *m, void *v)
896 {
897 struct trace_kprobe *tk = v;
898
899 seq_printf(m, " %-44s %15lu %15lu\n",
900 trace_event_name(&tk->tp.call),
901 trace_kprobe_nhit(tk),
902 tk->rp.kp.nmissed);
903
904 return 0;
905 }
906
907 static const struct seq_operations profile_seq_op = {
908 .start = probes_seq_start,
909 .next = probes_seq_next,
910 .stop = probes_seq_stop,
911 .show = probes_profile_seq_show
912 };
913
914 static int profile_open(struct inode *inode, struct file *file)
915 {
916 return seq_open(file, &profile_seq_op);
917 }
918
919 static const struct file_operations kprobe_profile_ops = {
920 .owner = THIS_MODULE,
921 .open = profile_open,
922 .read = seq_read,
923 .llseek = seq_lseek,
924 .release = seq_release,
925 };
926
927 /* Kprobe handler */
928 static nokprobe_inline void
929 __kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs,
930 struct trace_event_file *trace_file)
931 {
932 struct kprobe_trace_entry_head *entry;
933 struct ring_buffer_event *event;
934 struct ring_buffer *buffer;
935 int size, dsize, pc;
936 unsigned long irq_flags;
937 struct trace_event_call *call = &tk->tp.call;
938
939 WARN_ON(call != trace_file->event_call);
940
941 if (trace_trigger_soft_disabled(trace_file))
942 return;
943
944 local_save_flags(irq_flags);
945 pc = preempt_count();
946
947 dsize = __get_data_size(&tk->tp, regs);
948 size = sizeof(*entry) + tk->tp.size + dsize;
949
950 event = trace_event_buffer_lock_reserve(&buffer, trace_file,
951 call->event.type,
952 size, irq_flags, pc);
953 if (!event)
954 return;
955
956 entry = ring_buffer_event_data(event);
957 entry->ip = (unsigned long)tk->rp.kp.addr;
958 store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize);
959
960 event_trigger_unlock_commit_regs(trace_file, buffer, event,
961 entry, irq_flags, pc, regs);
962 }
963
964 static void
965 kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs)
966 {
967 struct event_file_link *link;
968
969 list_for_each_entry_rcu(link, &tk->tp.files, list)
970 __kprobe_trace_func(tk, regs, link->file);
971 }
972 NOKPROBE_SYMBOL(kprobe_trace_func);
973
974 /* Kretprobe handler */
975 static nokprobe_inline void
976 __kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
977 struct pt_regs *regs,
978 struct trace_event_file *trace_file)
979 {
980 struct kretprobe_trace_entry_head *entry;
981 struct ring_buffer_event *event;
982 struct ring_buffer *buffer;
983 int size, pc, dsize;
984 unsigned long irq_flags;
985 struct trace_event_call *call = &tk->tp.call;
986
987 WARN_ON(call != trace_file->event_call);
988
989 if (trace_trigger_soft_disabled(trace_file))
990 return;
991
992 local_save_flags(irq_flags);
993 pc = preempt_count();
994
995 dsize = __get_data_size(&tk->tp, regs);
996 size = sizeof(*entry) + tk->tp.size + dsize;
997
998 event = trace_event_buffer_lock_reserve(&buffer, trace_file,
999 call->event.type,
1000 size, irq_flags, pc);
1001 if (!event)
1002 return;
1003
1004 entry = ring_buffer_event_data(event);
1005 entry->func = (unsigned long)tk->rp.kp.addr;
1006 entry->ret_ip = (unsigned long)ri->ret_addr;
1007 store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize);
1008
1009 event_trigger_unlock_commit_regs(trace_file, buffer, event,
1010 entry, irq_flags, pc, regs);
1011 }
1012
1013 static void
1014 kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
1015 struct pt_regs *regs)
1016 {
1017 struct event_file_link *link;
1018
1019 list_for_each_entry_rcu(link, &tk->tp.files, list)
1020 __kretprobe_trace_func(tk, ri, regs, link->file);
1021 }
1022 NOKPROBE_SYMBOL(kretprobe_trace_func);
1023
1024 /* Event entry printers */
1025 static enum print_line_t
1026 print_kprobe_event(struct trace_iterator *iter, int flags,
1027 struct trace_event *event)
1028 {
1029 struct kprobe_trace_entry_head *field;
1030 struct trace_seq *s = &iter->seq;
1031 struct trace_probe *tp;
1032 u8 *data;
1033 int i;
1034
1035 field = (struct kprobe_trace_entry_head *)iter->ent;
1036 tp = container_of(event, struct trace_probe, call.event);
1037
1038 trace_seq_printf(s, "%s: (", trace_event_name(&tp->call));
1039
1040 if (!seq_print_ip_sym(s, field->ip, flags | TRACE_ITER_SYM_OFFSET))
1041 goto out;
1042
1043 trace_seq_putc(s, ')');
1044
1045 data = (u8 *)&field[1];
1046 for (i = 0; i < tp->nr_args; i++)
1047 if (!tp->args[i].type->print(s, tp->args[i].name,
1048 data + tp->args[i].offset, field))
1049 goto out;
1050
1051 trace_seq_putc(s, '\n');
1052 out:
1053 return trace_handle_return(s);
1054 }
1055
1056 static enum print_line_t
1057 print_kretprobe_event(struct trace_iterator *iter, int flags,
1058 struct trace_event *event)
1059 {
1060 struct kretprobe_trace_entry_head *field;
1061 struct trace_seq *s = &iter->seq;
1062 struct trace_probe *tp;
1063 u8 *data;
1064 int i;
1065
1066 field = (struct kretprobe_trace_entry_head *)iter->ent;
1067 tp = container_of(event, struct trace_probe, call.event);
1068
1069 trace_seq_printf(s, "%s: (", trace_event_name(&tp->call));
1070
1071 if (!seq_print_ip_sym(s, field->ret_ip, flags | TRACE_ITER_SYM_OFFSET))
1072 goto out;
1073
1074 trace_seq_puts(s, " <- ");
1075
1076 if (!seq_print_ip_sym(s, field->func, flags & ~TRACE_ITER_SYM_OFFSET))
1077 goto out;
1078
1079 trace_seq_putc(s, ')');
1080
1081 data = (u8 *)&field[1];
1082 for (i = 0; i < tp->nr_args; i++)
1083 if (!tp->args[i].type->print(s, tp->args[i].name,
1084 data + tp->args[i].offset, field))
1085 goto out;
1086
1087 trace_seq_putc(s, '\n');
1088
1089 out:
1090 return trace_handle_return(s);
1091 }
1092
1093
1094 static int kprobe_event_define_fields(struct trace_event_call *event_call)
1095 {
1096 int ret, i;
1097 struct kprobe_trace_entry_head field;
1098 struct trace_kprobe *tk = (struct trace_kprobe *)event_call->data;
1099
1100 DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0);
1101 /* Set argument names as fields */
1102 for (i = 0; i < tk->tp.nr_args; i++) {
1103 struct probe_arg *parg = &tk->tp.args[i];
1104
1105 ret = trace_define_field(event_call, parg->type->fmttype,
1106 parg->name,
1107 sizeof(field) + parg->offset,
1108 parg->type->size,
1109 parg->type->is_signed,
1110 FILTER_OTHER);
1111 if (ret)
1112 return ret;
1113 }
1114 return 0;
1115 }
1116
1117 static int kretprobe_event_define_fields(struct trace_event_call *event_call)
1118 {
1119 int ret, i;
1120 struct kretprobe_trace_entry_head field;
1121 struct trace_kprobe *tk = (struct trace_kprobe *)event_call->data;
1122
1123 DEFINE_FIELD(unsigned long, func, FIELD_STRING_FUNC, 0);
1124 DEFINE_FIELD(unsigned long, ret_ip, FIELD_STRING_RETIP, 0);
1125 /* Set argument names as fields */
1126 for (i = 0; i < tk->tp.nr_args; i++) {
1127 struct probe_arg *parg = &tk->tp.args[i];
1128
1129 ret = trace_define_field(event_call, parg->type->fmttype,
1130 parg->name,
1131 sizeof(field) + parg->offset,
1132 parg->type->size,
1133 parg->type->is_signed,
1134 FILTER_OTHER);
1135 if (ret)
1136 return ret;
1137 }
1138 return 0;
1139 }
1140
1141 #ifdef CONFIG_PERF_EVENTS
1142
1143 /* Kprobe profile handler */
1144 static void
1145 kprobe_perf_func(struct trace_kprobe *tk, struct pt_regs *regs)
1146 {
1147 struct trace_event_call *call = &tk->tp.call;
1148 struct bpf_prog *prog = call->prog;
1149 struct kprobe_trace_entry_head *entry;
1150 struct hlist_head *head;
1151 int size, __size, dsize;
1152 int rctx;
1153
1154 if (prog && !trace_call_bpf(prog, regs))
1155 return;
1156
1157 head = this_cpu_ptr(call->perf_events);
1158 if (hlist_empty(head))
1159 return;
1160
1161 dsize = __get_data_size(&tk->tp, regs);
1162 __size = sizeof(*entry) + tk->tp.size + dsize;
1163 size = ALIGN(__size + sizeof(u32), sizeof(u64));
1164 size -= sizeof(u32);
1165
1166 entry = perf_trace_buf_alloc(size, NULL, &rctx);
1167 if (!entry)
1168 return;
1169
1170 entry->ip = (unsigned long)tk->rp.kp.addr;
1171 memset(&entry[1], 0, dsize);
1172 store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize);
1173 perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs,
1174 head, NULL);
1175 }
1176 NOKPROBE_SYMBOL(kprobe_perf_func);
1177
1178 /* Kretprobe profile handler */
1179 static void
1180 kretprobe_perf_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
1181 struct pt_regs *regs)
1182 {
1183 struct trace_event_call *call = &tk->tp.call;
1184 struct bpf_prog *prog = call->prog;
1185 struct kretprobe_trace_entry_head *entry;
1186 struct hlist_head *head;
1187 int size, __size, dsize;
1188 int rctx;
1189
1190 if (prog && !trace_call_bpf(prog, regs))
1191 return;
1192
1193 head = this_cpu_ptr(call->perf_events);
1194 if (hlist_empty(head))
1195 return;
1196
1197 dsize = __get_data_size(&tk->tp, regs);
1198 __size = sizeof(*entry) + tk->tp.size + dsize;
1199 size = ALIGN(__size + sizeof(u32), sizeof(u64));
1200 size -= sizeof(u32);
1201
1202 entry = perf_trace_buf_alloc(size, NULL, &rctx);
1203 if (!entry)
1204 return;
1205
1206 entry->func = (unsigned long)tk->rp.kp.addr;
1207 entry->ret_ip = (unsigned long)ri->ret_addr;
1208 store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize);
1209 perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs,
1210 head, NULL);
1211 }
1212 NOKPROBE_SYMBOL(kretprobe_perf_func);
1213 #endif /* CONFIG_PERF_EVENTS */
1214
1215 /*
1216 * called by perf_trace_init() or __ftrace_set_clr_event() under event_mutex.
1217 *
1218 * kprobe_trace_self_tests_init() does enable_trace_probe/disable_trace_probe
1219 * lockless, but we can't race with this __init function.
1220 */
1221 static int kprobe_register(struct trace_event_call *event,
1222 enum trace_reg type, void *data)
1223 {
1224 struct trace_kprobe *tk = (struct trace_kprobe *)event->data;
1225 struct trace_event_file *file = data;
1226
1227 switch (type) {
1228 case TRACE_REG_REGISTER:
1229 return enable_trace_kprobe(tk, file);
1230 case TRACE_REG_UNREGISTER:
1231 return disable_trace_kprobe(tk, file);
1232
1233 #ifdef CONFIG_PERF_EVENTS
1234 case TRACE_REG_PERF_REGISTER:
1235 return enable_trace_kprobe(tk, NULL);
1236 case TRACE_REG_PERF_UNREGISTER:
1237 return disable_trace_kprobe(tk, NULL);
1238 case TRACE_REG_PERF_OPEN:
1239 case TRACE_REG_PERF_CLOSE:
1240 case TRACE_REG_PERF_ADD:
1241 case TRACE_REG_PERF_DEL:
1242 return 0;
1243 #endif
1244 }
1245 return 0;
1246 }
1247
1248 static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs)
1249 {
1250 struct trace_kprobe *tk = container_of(kp, struct trace_kprobe, rp.kp);
1251
1252 raw_cpu_inc(*tk->nhit);
1253
1254 if (tk->tp.flags & TP_FLAG_TRACE)
1255 kprobe_trace_func(tk, regs);
1256 #ifdef CONFIG_PERF_EVENTS
1257 if (tk->tp.flags & TP_FLAG_PROFILE)
1258 kprobe_perf_func(tk, regs);
1259 #endif
1260 return 0; /* We don't tweek kernel, so just return 0 */
1261 }
1262 NOKPROBE_SYMBOL(kprobe_dispatcher);
1263
1264 static int
1265 kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs)
1266 {
1267 struct trace_kprobe *tk = container_of(ri->rp, struct trace_kprobe, rp);
1268
1269 raw_cpu_inc(*tk->nhit);
1270
1271 if (tk->tp.flags & TP_FLAG_TRACE)
1272 kretprobe_trace_func(tk, ri, regs);
1273 #ifdef CONFIG_PERF_EVENTS
1274 if (tk->tp.flags & TP_FLAG_PROFILE)
1275 kretprobe_perf_func(tk, ri, regs);
1276 #endif
1277 return 0; /* We don't tweek kernel, so just return 0 */
1278 }
1279 NOKPROBE_SYMBOL(kretprobe_dispatcher);
1280
1281 static struct trace_event_functions kretprobe_funcs = {
1282 .trace = print_kretprobe_event
1283 };
1284
1285 static struct trace_event_functions kprobe_funcs = {
1286 .trace = print_kprobe_event
1287 };
1288
1289 static int register_kprobe_event(struct trace_kprobe *tk)
1290 {
1291 struct trace_event_call *call = &tk->tp.call;
1292 int ret;
1293
1294 /* Initialize trace_event_call */
1295 INIT_LIST_HEAD(&call->class->fields);
1296 if (trace_kprobe_is_return(tk)) {
1297 call->event.funcs = &kretprobe_funcs;
1298 call->class->define_fields = kretprobe_event_define_fields;
1299 } else {
1300 call->event.funcs = &kprobe_funcs;
1301 call->class->define_fields = kprobe_event_define_fields;
1302 }
1303 if (set_print_fmt(&tk->tp, trace_kprobe_is_return(tk)) < 0)
1304 return -ENOMEM;
1305 ret = register_trace_event(&call->event);
1306 if (!ret) {
1307 kfree(call->print_fmt);
1308 return -ENODEV;
1309 }
1310 call->flags = TRACE_EVENT_FL_KPROBE;
1311 call->class->reg = kprobe_register;
1312 call->data = tk;
1313 ret = trace_add_event_call(call);
1314 if (ret) {
1315 pr_info("Failed to register kprobe event: %s\n",
1316 trace_event_name(call));
1317 kfree(call->print_fmt);
1318 unregister_trace_event(&call->event);
1319 }
1320 return ret;
1321 }
1322
1323 static int unregister_kprobe_event(struct trace_kprobe *tk)
1324 {
1325 int ret;
1326
1327 /* tp->event is unregistered in trace_remove_event_call() */
1328 ret = trace_remove_event_call(&tk->tp.call);
1329 if (!ret)
1330 kfree(tk->tp.call.print_fmt);
1331 return ret;
1332 }
1333
1334 /* Make a tracefs interface for controlling probe points */
1335 static __init int init_kprobe_trace(void)
1336 {
1337 struct dentry *d_tracer;
1338 struct dentry *entry;
1339
1340 if (register_module_notifier(&trace_kprobe_module_nb))
1341 return -EINVAL;
1342
1343 d_tracer = tracing_init_dentry();
1344 if (IS_ERR(d_tracer))
1345 return 0;
1346
1347 entry = tracefs_create_file("kprobe_events", 0644, d_tracer,
1348 NULL, &kprobe_events_ops);
1349
1350 /* Event list interface */
1351 if (!entry)
1352 pr_warn("Could not create tracefs 'kprobe_events' entry\n");
1353
1354 /* Profile interface */
1355 entry = tracefs_create_file("kprobe_profile", 0444, d_tracer,
1356 NULL, &kprobe_profile_ops);
1357
1358 if (!entry)
1359 pr_warn("Could not create tracefs 'kprobe_profile' entry\n");
1360 return 0;
1361 }
1362 fs_initcall(init_kprobe_trace);
1363
1364
1365 #ifdef CONFIG_FTRACE_STARTUP_TEST
1366 /*
1367 * The "__used" keeps gcc from removing the function symbol
1368 * from the kallsyms table. 'noinline' makes sure that there
1369 * isn't an inlined version used by the test method below
1370 */
1371 static __used __init noinline int
1372 kprobe_trace_selftest_target(int a1, int a2, int a3, int a4, int a5, int a6)
1373 {
1374 return a1 + a2 + a3 + a4 + a5 + a6;
1375 }
1376
1377 static __init struct trace_event_file *
1378 find_trace_probe_file(struct trace_kprobe *tk, struct trace_array *tr)
1379 {
1380 struct trace_event_file *file;
1381
1382 list_for_each_entry(file, &tr->events, list)
1383 if (file->event_call == &tk->tp.call)
1384 return file;
1385
1386 return NULL;
1387 }
1388
1389 /*
1390 * Nobody but us can call enable_trace_kprobe/disable_trace_kprobe at this
1391 * stage, we can do this lockless.
1392 */
1393 static __init int kprobe_trace_self_tests_init(void)
1394 {
1395 int ret, warn = 0;
1396 int (*target)(int, int, int, int, int, int);
1397 struct trace_kprobe *tk;
1398 struct trace_event_file *file;
1399
1400 if (tracing_is_disabled())
1401 return -ENODEV;
1402
1403 target = kprobe_trace_selftest_target;
1404
1405 pr_info("Testing kprobe tracing: ");
1406
1407 ret = traceprobe_command("p:testprobe kprobe_trace_selftest_target "
1408 "$stack $stack0 +0($stack)",
1409 create_trace_kprobe);
1410 if (WARN_ON_ONCE(ret)) {
1411 pr_warn("error on probing function entry.\n");
1412 warn++;
1413 } else {
1414 /* Enable trace point */
1415 tk = find_trace_kprobe("testprobe", KPROBE_EVENT_SYSTEM);
1416 if (WARN_ON_ONCE(tk == NULL)) {
1417 pr_warn("error on getting new probe.\n");
1418 warn++;
1419 } else {
1420 file = find_trace_probe_file(tk, top_trace_array());
1421 if (WARN_ON_ONCE(file == NULL)) {
1422 pr_warn("error on getting probe file.\n");
1423 warn++;
1424 } else
1425 enable_trace_kprobe(tk, file);
1426 }
1427 }
1428
1429 ret = traceprobe_command("r:testprobe2 kprobe_trace_selftest_target "
1430 "$retval", create_trace_kprobe);
1431 if (WARN_ON_ONCE(ret)) {
1432 pr_warn("error on probing function return.\n");
1433 warn++;
1434 } else {
1435 /* Enable trace point */
1436 tk = find_trace_kprobe("testprobe2", KPROBE_EVENT_SYSTEM);
1437 if (WARN_ON_ONCE(tk == NULL)) {
1438 pr_warn("error on getting 2nd new probe.\n");
1439 warn++;
1440 } else {
1441 file = find_trace_probe_file(tk, top_trace_array());
1442 if (WARN_ON_ONCE(file == NULL)) {
1443 pr_warn("error on getting probe file.\n");
1444 warn++;
1445 } else
1446 enable_trace_kprobe(tk, file);
1447 }
1448 }
1449
1450 if (warn)
1451 goto end;
1452
1453 ret = target(1, 2, 3, 4, 5, 6);
1454
1455 /*
1456 * Not expecting an error here, the check is only to prevent the
1457 * optimizer from removing the call to target() as otherwise there
1458 * are no side-effects and the call is never performed.
1459 */
1460 if (ret != 21)
1461 warn++;
1462
1463 /* Disable trace points before removing it */
1464 tk = find_trace_kprobe("testprobe", KPROBE_EVENT_SYSTEM);
1465 if (WARN_ON_ONCE(tk == NULL)) {
1466 pr_warn("error on getting test probe.\n");
1467 warn++;
1468 } else {
1469 if (trace_kprobe_nhit(tk) != 1) {
1470 pr_warn("incorrect number of testprobe hits\n");
1471 warn++;
1472 }
1473
1474 file = find_trace_probe_file(tk, top_trace_array());
1475 if (WARN_ON_ONCE(file == NULL)) {
1476 pr_warn("error on getting probe file.\n");
1477 warn++;
1478 } else
1479 disable_trace_kprobe(tk, file);
1480 }
1481
1482 tk = find_trace_kprobe("testprobe2", KPROBE_EVENT_SYSTEM);
1483 if (WARN_ON_ONCE(tk == NULL)) {
1484 pr_warn("error on getting 2nd test probe.\n");
1485 warn++;
1486 } else {
1487 if (trace_kprobe_nhit(tk) != 1) {
1488 pr_warn("incorrect number of testprobe2 hits\n");
1489 warn++;
1490 }
1491
1492 file = find_trace_probe_file(tk, top_trace_array());
1493 if (WARN_ON_ONCE(file == NULL)) {
1494 pr_warn("error on getting probe file.\n");
1495 warn++;
1496 } else
1497 disable_trace_kprobe(tk, file);
1498 }
1499
1500 ret = traceprobe_command("-:testprobe", create_trace_kprobe);
1501 if (WARN_ON_ONCE(ret)) {
1502 pr_warn("error on deleting a probe.\n");
1503 warn++;
1504 }
1505
1506 ret = traceprobe_command("-:testprobe2", create_trace_kprobe);
1507 if (WARN_ON_ONCE(ret)) {
1508 pr_warn("error on deleting a probe.\n");
1509 warn++;
1510 }
1511
1512 end:
1513 release_all_trace_kprobes();
1514 if (warn)
1515 pr_cont("NG: Some tests are failed. Please check them.\n");
1516 else
1517 pr_cont("OK\n");
1518 return 0;
1519 }
1520
1521 late_initcall(kprobe_trace_self_tests_init);
1522
1523 #endif
Ubuntu Artful kernel mirror