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dt-bindings: pinctrl: add bindings for MediaTek MT6779 SoC
[linux/fpc-iii.git] / kernel / trace / trace_uprobe.c
blobfdd47f99b18fdb640346dcdaf0a76f1e1d15d116
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * uprobes-based tracing events
4 *
5 * Copyright (C) IBM Corporation, 2010-2012
6 * Author: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
7 */
8 #define pr_fmt(fmt) "trace_uprobe: " fmt
9
10 #include <linux/security.h>
11 #include <linux/ctype.h>
12 #include <linux/module.h>
13 #include <linux/uaccess.h>
14 #include <linux/uprobes.h>
15 #include <linux/namei.h>
16 #include <linux/string.h>
17 #include <linux/rculist.h>
18
19 #include "trace_dynevent.h"
20 #include "trace_probe.h"
21 #include "trace_probe_tmpl.h"
22
23 #define UPROBE_EVENT_SYSTEM "uprobes"
24
25 struct uprobe_trace_entry_head {
26 struct trace_entry ent;
27 unsigned long vaddr[];
28 };
29
30 #define SIZEOF_TRACE_ENTRY(is_return) \
31 (sizeof(struct uprobe_trace_entry_head) + \
32 sizeof(unsigned long) * (is_return ? 2 : 1))
33
34 #define DATAOF_TRACE_ENTRY(entry, is_return) \
35 ((void*)(entry) + SIZEOF_TRACE_ENTRY(is_return))
36
37 static int trace_uprobe_create(int argc, const char **argv);
38 static int trace_uprobe_show(struct seq_file *m, struct dyn_event *ev);
39 static int trace_uprobe_release(struct dyn_event *ev);
40 static bool trace_uprobe_is_busy(struct dyn_event *ev);
41 static bool trace_uprobe_match(const char *system, const char *event,
42 int argc, const char **argv, struct dyn_event *ev);
43
44 static struct dyn_event_operations trace_uprobe_ops = {
45 .create = trace_uprobe_create,
46 .show = trace_uprobe_show,
47 .is_busy = trace_uprobe_is_busy,
48 .free = trace_uprobe_release,
49 .match = trace_uprobe_match,
50 };
51
52 /*
53 * uprobe event core functions
54 */
55 struct trace_uprobe {
56 struct dyn_event devent;
57 struct uprobe_consumer consumer;
58 struct path path;
59 struct inode *inode;
60 char *filename;
61 unsigned long offset;
62 unsigned long ref_ctr_offset;
63 unsigned long nhit;
64 struct trace_probe tp;
65 };
66
67 static bool is_trace_uprobe(struct dyn_event *ev)
68 {
69 return ev->ops == &trace_uprobe_ops;
70 }
71
72 static struct trace_uprobe *to_trace_uprobe(struct dyn_event *ev)
73 {
74 return container_of(ev, struct trace_uprobe, devent);
75 }
76
77 /**
78 * for_each_trace_uprobe - iterate over the trace_uprobe list
79 * @pos: the struct trace_uprobe * for each entry
80 * @dpos: the struct dyn_event * to use as a loop cursor
81 */
82 #define for_each_trace_uprobe(pos, dpos) \
83 for_each_dyn_event(dpos) \
84 if (is_trace_uprobe(dpos) && (pos = to_trace_uprobe(dpos)))
85
86 #define SIZEOF_TRACE_UPROBE(n) \
87 (offsetof(struct trace_uprobe, tp.args) + \
88 (sizeof(struct probe_arg) * (n)))
89
90 static int register_uprobe_event(struct trace_uprobe *tu);
91 static int unregister_uprobe_event(struct trace_uprobe *tu);
92
93 struct uprobe_dispatch_data {
94 struct trace_uprobe *tu;
95 unsigned long bp_addr;
96 };
97
98 static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs);
99 static int uretprobe_dispatcher(struct uprobe_consumer *con,
100 unsigned long func, struct pt_regs *regs);
101
102 #ifdef CONFIG_STACK_GROWSUP
103 static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n)
104 {
105 return addr - (n * sizeof(long));
106 }
107 #else
108 static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n)
109 {
110 return addr + (n * sizeof(long));
111 }
112 #endif
113
114 static unsigned long get_user_stack_nth(struct pt_regs *regs, unsigned int n)
115 {
116 unsigned long ret;
117 unsigned long addr = user_stack_pointer(regs);
118
119 addr = adjust_stack_addr(addr, n);
120
121 if (copy_from_user(&ret, (void __force __user *) addr, sizeof(ret)))
122 return 0;
123
124 return ret;
125 }
126
127 /*
128 * Uprobes-specific fetch functions
129 */
130 static nokprobe_inline int
131 probe_mem_read(void *dest, void *src, size_t size)
132 {
133 void __user *vaddr = (void __force __user *)src;
134
135 return copy_from_user(dest, vaddr, size) ? -EFAULT : 0;
136 }
137
138 static nokprobe_inline int
139 probe_mem_read_user(void *dest, void *src, size_t size)
140 {
141 return probe_mem_read(dest, src, size);
142 }
143
144 /*
145 * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max
146 * length and relative data location.
147 */
148 static nokprobe_inline int
149 fetch_store_string(unsigned long addr, void *dest, void *base)
150 {
151 long ret;
152 u32 loc = *(u32 *)dest;
153 int maxlen = get_loc_len(loc);
154 u8 *dst = get_loc_data(dest, base);
155 void __user *src = (void __force __user *) addr;
156
157 if (unlikely(!maxlen))
158 return -ENOMEM;
159
160 if (addr == FETCH_TOKEN_COMM)
161 ret = strlcpy(dst, current->comm, maxlen);
162 else
163 ret = strncpy_from_user(dst, src, maxlen);
164 if (ret >= 0) {
165 if (ret == maxlen)
166 dst[ret - 1] = '\0';
167 else
168 /*
169 * Include the terminating null byte. In this case it
170 * was copied by strncpy_from_user but not accounted
171 * for in ret.
172 */
173 ret++;
174 *(u32 *)dest = make_data_loc(ret, (void *)dst - base);
175 }
176
177 return ret;
178 }
179
180 static nokprobe_inline int
181 fetch_store_string_user(unsigned long addr, void *dest, void *base)
182 {
183 return fetch_store_string(addr, dest, base);
184 }
185
186 /* Return the length of string -- including null terminal byte */
187 static nokprobe_inline int
188 fetch_store_strlen(unsigned long addr)
189 {
190 int len;
191 void __user *vaddr = (void __force __user *) addr;
192
193 if (addr == FETCH_TOKEN_COMM)
194 len = strlen(current->comm) + 1;
195 else
196 len = strnlen_user(vaddr, MAX_STRING_SIZE);
197
198 return (len > MAX_STRING_SIZE) ? 0 : len;
199 }
200
201 static nokprobe_inline int
202 fetch_store_strlen_user(unsigned long addr)
203 {
204 return fetch_store_strlen(addr);
205 }
206
207 static unsigned long translate_user_vaddr(unsigned long file_offset)
208 {
209 unsigned long base_addr;
210 struct uprobe_dispatch_data *udd;
211
212 udd = (void *) current->utask->vaddr;
213
214 base_addr = udd->bp_addr - udd->tu->offset;
215 return base_addr + file_offset;
216 }
217
218 /* Note that we don't verify it, since the code does not come from user space */
219 static int
220 process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs, void *dest,
221 void *base)
222 {
223 unsigned long val;
224
225 /* 1st stage: get value from context */
226 switch (code->op) {
227 case FETCH_OP_REG:
228 val = regs_get_register(regs, code->param);
229 break;
230 case FETCH_OP_STACK:
231 val = get_user_stack_nth(regs, code->param);
232 break;
233 case FETCH_OP_STACKP:
234 val = user_stack_pointer(regs);
235 break;
236 case FETCH_OP_RETVAL:
237 val = regs_return_value(regs);
238 break;
239 case FETCH_OP_IMM:
240 val = code->immediate;
241 break;
242 case FETCH_OP_COMM:
243 val = FETCH_TOKEN_COMM;
244 break;
245 case FETCH_OP_DATA:
246 val = (unsigned long)code->data;
247 break;
248 case FETCH_OP_FOFFS:
249 val = translate_user_vaddr(code->immediate);
250 break;
251 default:
252 return -EILSEQ;
253 }
254 code++;
255
256 return process_fetch_insn_bottom(code, val, dest, base);
257 }
258 NOKPROBE_SYMBOL(process_fetch_insn)
259
260 static inline void init_trace_uprobe_filter(struct trace_uprobe_filter *filter)
261 {
262 rwlock_init(&filter->rwlock);
263 filter->nr_systemwide = 0;
264 INIT_LIST_HEAD(&filter->perf_events);
265 }
266
267 static inline bool uprobe_filter_is_empty(struct trace_uprobe_filter *filter)
268 {
269 return !filter->nr_systemwide && list_empty(&filter->perf_events);
270 }
271
272 static inline bool is_ret_probe(struct trace_uprobe *tu)
273 {
274 return tu->consumer.ret_handler != NULL;
275 }
276
277 static bool trace_uprobe_is_busy(struct dyn_event *ev)
278 {
279 struct trace_uprobe *tu = to_trace_uprobe(ev);
280
281 return trace_probe_is_enabled(&tu->tp);
282 }
283
284 static bool trace_uprobe_match_command_head(struct trace_uprobe *tu,
285 int argc, const char **argv)
286 {
287 char buf[MAX_ARGSTR_LEN + 1];
288 int len;
289
290 if (!argc)
291 return true;
292
293 len = strlen(tu->filename);
294 if (strncmp(tu->filename, argv[0], len) || argv[0][len] != ':')
295 return false;
296
297 if (tu->ref_ctr_offset == 0)
298 snprintf(buf, sizeof(buf), "0x%0*lx",
299 (int)(sizeof(void *) * 2), tu->offset);
300 else
301 snprintf(buf, sizeof(buf), "0x%0*lx(0x%lx)",
302 (int)(sizeof(void *) * 2), tu->offset,
303 tu->ref_ctr_offset);
304 if (strcmp(buf, &argv[0][len + 1]))
305 return false;
306
307 argc--; argv++;
308
309 return trace_probe_match_command_args(&tu->tp, argc, argv);
310 }
311
312 static bool trace_uprobe_match(const char *system, const char *event,
313 int argc, const char **argv, struct dyn_event *ev)
314 {
315 struct trace_uprobe *tu = to_trace_uprobe(ev);
316
317 return strcmp(trace_probe_name(&tu->tp), event) == 0 &&
318 (!system || strcmp(trace_probe_group_name(&tu->tp), system) == 0) &&
319 trace_uprobe_match_command_head(tu, argc, argv);
320 }
321
322 static nokprobe_inline struct trace_uprobe *
323 trace_uprobe_primary_from_call(struct trace_event_call *call)
324 {
325 struct trace_probe *tp;
326
327 tp = trace_probe_primary_from_call(call);
328 if (WARN_ON_ONCE(!tp))
329 return NULL;
330
331 return container_of(tp, struct trace_uprobe, tp);
332 }
333
334 /*
335 * Allocate new trace_uprobe and initialize it (including uprobes).
336 */
337 static struct trace_uprobe *
338 alloc_trace_uprobe(const char *group, const char *event, int nargs, bool is_ret)
339 {
340 struct trace_uprobe *tu;
341 int ret;
342
343 tu = kzalloc(SIZEOF_TRACE_UPROBE(nargs), GFP_KERNEL);
344 if (!tu)
345 return ERR_PTR(-ENOMEM);
346
347 ret = trace_probe_init(&tu->tp, event, group, true);
348 if (ret < 0)
349 goto error;
350
351 dyn_event_init(&tu->devent, &trace_uprobe_ops);
352 tu->consumer.handler = uprobe_dispatcher;
353 if (is_ret)
354 tu->consumer.ret_handler = uretprobe_dispatcher;
355 init_trace_uprobe_filter(tu->tp.event->filter);
356 return tu;
357
358 error:
359 kfree(tu);
360
361 return ERR_PTR(ret);
362 }
363
364 static void free_trace_uprobe(struct trace_uprobe *tu)
365 {
366 if (!tu)
367 return;
368
369 path_put(&tu->path);
370 trace_probe_cleanup(&tu->tp);
371 kfree(tu->filename);
372 kfree(tu);
373 }
374
375 static struct trace_uprobe *find_probe_event(const char *event, const char *group)
376 {
377 struct dyn_event *pos;
378 struct trace_uprobe *tu;
379
380 for_each_trace_uprobe(tu, pos)
381 if (strcmp(trace_probe_name(&tu->tp), event) == 0 &&
382 strcmp(trace_probe_group_name(&tu->tp), group) == 0)
383 return tu;
384
385 return NULL;
386 }
387
388 /* Unregister a trace_uprobe and probe_event */
389 static int unregister_trace_uprobe(struct trace_uprobe *tu)
390 {
391 int ret;
392
393 if (trace_probe_has_sibling(&tu->tp))
394 goto unreg;
395
396 ret = unregister_uprobe_event(tu);
397 if (ret)
398 return ret;
399
400 unreg:
401 dyn_event_remove(&tu->devent);
402 trace_probe_unlink(&tu->tp);
403 free_trace_uprobe(tu);
404 return 0;
405 }
406
407 static bool trace_uprobe_has_same_uprobe(struct trace_uprobe *orig,
408 struct trace_uprobe *comp)
409 {
410 struct trace_probe_event *tpe = orig->tp.event;
411 struct trace_probe *pos;
412 struct inode *comp_inode = d_real_inode(comp->path.dentry);
413 int i;
414
415 list_for_each_entry(pos, &tpe->probes, list) {
416 orig = container_of(pos, struct trace_uprobe, tp);
417 if (comp_inode != d_real_inode(orig->path.dentry) ||
418 comp->offset != orig->offset)
419 continue;
420
421 /*
422 * trace_probe_compare_arg_type() ensured that nr_args and
423 * each argument name and type are same. Let's compare comm.
424 */
425 for (i = 0; i < orig->tp.nr_args; i++) {
426 if (strcmp(orig->tp.args[i].comm,
427 comp->tp.args[i].comm))
428 break;
429 }
430
431 if (i == orig->tp.nr_args)
432 return true;
433 }
434
435 return false;
436 }
437
438 static int append_trace_uprobe(struct trace_uprobe *tu, struct trace_uprobe *to)
439 {
440 int ret;
441
442 ret = trace_probe_compare_arg_type(&tu->tp, &to->tp);
443 if (ret) {
444 /* Note that argument starts index = 2 */
445 trace_probe_log_set_index(ret + 1);
446 trace_probe_log_err(0, DIFF_ARG_TYPE);
447 return -EEXIST;
448 }
449 if (trace_uprobe_has_same_uprobe(to, tu)) {
450 trace_probe_log_set_index(0);
451 trace_probe_log_err(0, SAME_PROBE);
452 return -EEXIST;
453 }
454
455 /* Append to existing event */
456 ret = trace_probe_append(&tu->tp, &to->tp);
457 if (!ret)
458 dyn_event_add(&tu->devent);
459
460 return ret;
461 }
462
463 /*
464 * Uprobe with multiple reference counter is not allowed. i.e.
465 * If inode and offset matches, reference counter offset *must*
466 * match as well. Though, there is one exception: If user is
467 * replacing old trace_uprobe with new one(same group/event),
468 * then we allow same uprobe with new reference counter as far
469 * as the new one does not conflict with any other existing
470 * ones.
471 */
472 static int validate_ref_ctr_offset(struct trace_uprobe *new)
473 {
474 struct dyn_event *pos;
475 struct trace_uprobe *tmp;
476 struct inode *new_inode = d_real_inode(new->path.dentry);
477
478 for_each_trace_uprobe(tmp, pos) {
479 if (new_inode == d_real_inode(tmp->path.dentry) &&
480 new->offset == tmp->offset &&
481 new->ref_ctr_offset != tmp->ref_ctr_offset) {
482 pr_warn("Reference counter offset mismatch.");
483 return -EINVAL;
484 }
485 }
486 return 0;
487 }
488
489 /* Register a trace_uprobe and probe_event */
490 static int register_trace_uprobe(struct trace_uprobe *tu)
491 {
492 struct trace_uprobe *old_tu;
493 int ret;
494
495 mutex_lock(&event_mutex);
496
497 ret = validate_ref_ctr_offset(tu);
498 if (ret)
499 goto end;
500
501 /* register as an event */
502 old_tu = find_probe_event(trace_probe_name(&tu->tp),
503 trace_probe_group_name(&tu->tp));
504 if (old_tu) {
505 if (is_ret_probe(tu) != is_ret_probe(old_tu)) {
506 trace_probe_log_set_index(0);
507 trace_probe_log_err(0, DIFF_PROBE_TYPE);
508 ret = -EEXIST;
509 } else {
510 ret = append_trace_uprobe(tu, old_tu);
511 }
512 goto end;
513 }
514
515 ret = register_uprobe_event(tu);
516 if (ret) {
517 pr_warn("Failed to register probe event(%d)\n", ret);
518 goto end;
519 }
520
521 dyn_event_add(&tu->devent);
522
523 end:
524 mutex_unlock(&event_mutex);
525
526 return ret;
527 }
528
529 /*
530 * Argument syntax:
531 * - Add uprobe: p|r[:[GRP/]EVENT] PATH:OFFSET [FETCHARGS]
532 */
533 static int trace_uprobe_create(int argc, const char **argv)
534 {
535 struct trace_uprobe *tu;
536 const char *event = NULL, *group = UPROBE_EVENT_SYSTEM;
537 char *arg, *filename, *rctr, *rctr_end, *tmp;
538 char buf[MAX_EVENT_NAME_LEN];
539 struct path path;
540 unsigned long offset, ref_ctr_offset;
541 bool is_return = false;
542 int i, ret;
543
544 ret = 0;
545 ref_ctr_offset = 0;
546
547 switch (argv[0][0]) {
548 case 'r':
549 is_return = true;
550 break;
551 case 'p':
552 break;
553 default:
554 return -ECANCELED;
555 }
556
557 if (argc < 2)
558 return -ECANCELED;
559
560 if (argv[0][1] == ':')
561 event = &argv[0][2];
562
563 if (!strchr(argv[1], '/'))
564 return -ECANCELED;
565
566 filename = kstrdup(argv[1], GFP_KERNEL);
567 if (!filename)
568 return -ENOMEM;
569
570 /* Find the last occurrence, in case the path contains ':' too. */
571 arg = strrchr(filename, ':');
572 if (!arg || !isdigit(arg[1])) {
573 kfree(filename);
574 return -ECANCELED;
575 }
576
577 trace_probe_log_init("trace_uprobe", argc, argv);
578 trace_probe_log_set_index(1); /* filename is the 2nd argument */
579
580 *arg++ = '\0';
581 ret = kern_path(filename, LOOKUP_FOLLOW, &path);
582 if (ret) {
583 trace_probe_log_err(0, FILE_NOT_FOUND);
584 kfree(filename);
585 trace_probe_log_clear();
586 return ret;
587 }
588 if (!d_is_reg(path.dentry)) {
589 trace_probe_log_err(0, NO_REGULAR_FILE);
590 ret = -EINVAL;
591 goto fail_address_parse;
592 }
593
594 /* Parse reference counter offset if specified. */
595 rctr = strchr(arg, '(');
596 if (rctr) {
597 rctr_end = strchr(rctr, ')');
598 if (!rctr_end) {
599 ret = -EINVAL;
600 rctr_end = rctr + strlen(rctr);
601 trace_probe_log_err(rctr_end - filename,
602 REFCNT_OPEN_BRACE);
603 goto fail_address_parse;
604 } else if (rctr_end[1] != '\0') {
605 ret = -EINVAL;
606 trace_probe_log_err(rctr_end + 1 - filename,
607 BAD_REFCNT_SUFFIX);
608 goto fail_address_parse;
609 }
610
611 *rctr++ = '\0';
612 *rctr_end = '\0';
613 ret = kstrtoul(rctr, 0, &ref_ctr_offset);
614 if (ret) {
615 trace_probe_log_err(rctr - filename, BAD_REFCNT);
616 goto fail_address_parse;
617 }
618 }
619
620 /* Parse uprobe offset. */
621 ret = kstrtoul(arg, 0, &offset);
622 if (ret) {
623 trace_probe_log_err(arg - filename, BAD_UPROBE_OFFS);
624 goto fail_address_parse;
625 }
626
627 /* setup a probe */
628 trace_probe_log_set_index(0);
629 if (event) {
630 ret = traceprobe_parse_event_name(&event, &group, buf,
631 event - argv[0]);
632 if (ret)
633 goto fail_address_parse;
634 } else {
635 char *tail;
636 char *ptr;
637
638 tail = kstrdup(kbasename(filename), GFP_KERNEL);
639 if (!tail) {
640 ret = -ENOMEM;
641 goto fail_address_parse;
642 }
643
644 ptr = strpbrk(tail, ".-_");
645 if (ptr)
646 *ptr = '\0';
647
648 snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_0x%lx", 'p', tail, offset);
649 event = buf;
650 kfree(tail);
651 }
652
653 argc -= 2;
654 argv += 2;
655
656 tu = alloc_trace_uprobe(group, event, argc, is_return);
657 if (IS_ERR(tu)) {
658 ret = PTR_ERR(tu);
659 /* This must return -ENOMEM otherwise there is a bug */
660 WARN_ON_ONCE(ret != -ENOMEM);
661 goto fail_address_parse;
662 }
663 tu->offset = offset;
664 tu->ref_ctr_offset = ref_ctr_offset;
665 tu->path = path;
666 tu->filename = filename;
667
668 /* parse arguments */
669 for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) {
670 tmp = kstrdup(argv[i], GFP_KERNEL);
671 if (!tmp) {
672 ret = -ENOMEM;
673 goto error;
674 }
675
676 trace_probe_log_set_index(i + 2);
677 ret = traceprobe_parse_probe_arg(&tu->tp, i, tmp,
678 is_return ? TPARG_FL_RETURN : 0);
679 kfree(tmp);
680 if (ret)
681 goto error;
682 }
683
684 ret = traceprobe_set_print_fmt(&tu->tp, is_ret_probe(tu));
685 if (ret < 0)
686 goto error;
687
688 ret = register_trace_uprobe(tu);
689 if (!ret)
690 goto out;
691
692 error:
693 free_trace_uprobe(tu);
694 out:
695 trace_probe_log_clear();
696 return ret;
697
698 fail_address_parse:
699 trace_probe_log_clear();
700 path_put(&path);
701 kfree(filename);
702
703 return ret;
704 }
705
706 static int create_or_delete_trace_uprobe(int argc, char **argv)
707 {
708 int ret;
709
710 if (argv[0][0] == '-')
711 return dyn_event_release(argc, argv, &trace_uprobe_ops);
712
713 ret = trace_uprobe_create(argc, (const char **)argv);
714 return ret == -ECANCELED ? -EINVAL : ret;
715 }
716
717 static int trace_uprobe_release(struct dyn_event *ev)
718 {
719 struct trace_uprobe *tu = to_trace_uprobe(ev);
720
721 return unregister_trace_uprobe(tu);
722 }
723
724 /* Probes listing interfaces */
725 static int trace_uprobe_show(struct seq_file *m, struct dyn_event *ev)
726 {
727 struct trace_uprobe *tu = to_trace_uprobe(ev);
728 char c = is_ret_probe(tu) ? 'r' : 'p';
729 int i;
730
731 seq_printf(m, "%c:%s/%s %s:0x%0*lx", c, trace_probe_group_name(&tu->tp),
732 trace_probe_name(&tu->tp), tu->filename,
733 (int)(sizeof(void *) * 2), tu->offset);
734
735 if (tu->ref_ctr_offset)
736 seq_printf(m, "(0x%lx)", tu->ref_ctr_offset);
737
738 for (i = 0; i < tu->tp.nr_args; i++)
739 seq_printf(m, " %s=%s", tu->tp.args[i].name, tu->tp.args[i].comm);
740
741 seq_putc(m, '\n');
742 return 0;
743 }
744
745 static int probes_seq_show(struct seq_file *m, void *v)
746 {
747 struct dyn_event *ev = v;
748
749 if (!is_trace_uprobe(ev))
750 return 0;
751
752 return trace_uprobe_show(m, ev);
753 }
754
755 static const struct seq_operations probes_seq_op = {
756 .start = dyn_event_seq_start,
757 .next = dyn_event_seq_next,
758 .stop = dyn_event_seq_stop,
759 .show = probes_seq_show
760 };
761
762 static int probes_open(struct inode *inode, struct file *file)
763 {
764 int ret;
765
766 ret = security_locked_down(LOCKDOWN_TRACEFS);
767 if (ret)
768 return ret;
769
770 if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
771 ret = dyn_events_release_all(&trace_uprobe_ops);
772 if (ret)
773 return ret;
774 }
775
776 return seq_open(file, &probes_seq_op);
777 }
778
779 static ssize_t probes_write(struct file *file, const char __user *buffer,
780 size_t count, loff_t *ppos)
781 {
782 return trace_parse_run_command(file, buffer, count, ppos,
783 create_or_delete_trace_uprobe);
784 }
785
786 static const struct file_operations uprobe_events_ops = {
787 .owner = THIS_MODULE,
788 .open = probes_open,
789 .read = seq_read,
790 .llseek = seq_lseek,
791 .release = seq_release,
792 .write = probes_write,
793 };
794
795 /* Probes profiling interfaces */
796 static int probes_profile_seq_show(struct seq_file *m, void *v)
797 {
798 struct dyn_event *ev = v;
799 struct trace_uprobe *tu;
800
801 if (!is_trace_uprobe(ev))
802 return 0;
803
804 tu = to_trace_uprobe(ev);
805 seq_printf(m, " %s %-44s %15lu\n", tu->filename,
806 trace_probe_name(&tu->tp), tu->nhit);
807 return 0;
808 }
809
810 static const struct seq_operations profile_seq_op = {
811 .start = dyn_event_seq_start,
812 .next = dyn_event_seq_next,
813 .stop = dyn_event_seq_stop,
814 .show = probes_profile_seq_show
815 };
816
817 static int profile_open(struct inode *inode, struct file *file)
818 {
819 int ret;
820
821 ret = security_locked_down(LOCKDOWN_TRACEFS);
822 if (ret)
823 return ret;
824
825 return seq_open(file, &profile_seq_op);
826 }
827
828 static const struct file_operations uprobe_profile_ops = {
829 .owner = THIS_MODULE,
830 .open = profile_open,
831 .read = seq_read,
832 .llseek = seq_lseek,
833 .release = seq_release,
834 };
835
836 struct uprobe_cpu_buffer {
837 struct mutex mutex;
838 void *buf;
839 };
840 static struct uprobe_cpu_buffer __percpu *uprobe_cpu_buffer;
841 static int uprobe_buffer_refcnt;
842
843 static int uprobe_buffer_init(void)
844 {
845 int cpu, err_cpu;
846
847 uprobe_cpu_buffer = alloc_percpu(struct uprobe_cpu_buffer);
848 if (uprobe_cpu_buffer == NULL)
849 return -ENOMEM;
850
851 for_each_possible_cpu(cpu) {
852 struct page *p = alloc_pages_node(cpu_to_node(cpu),
853 GFP_KERNEL, 0);
854 if (p == NULL) {
855 err_cpu = cpu;
856 goto err;
857 }
858 per_cpu_ptr(uprobe_cpu_buffer, cpu)->buf = page_address(p);
859 mutex_init(&per_cpu_ptr(uprobe_cpu_buffer, cpu)->mutex);
860 }
861
862 return 0;
863
864 err:
865 for_each_possible_cpu(cpu) {
866 if (cpu == err_cpu)
867 break;
868 free_page((unsigned long)per_cpu_ptr(uprobe_cpu_buffer, cpu)->buf);
869 }
870
871 free_percpu(uprobe_cpu_buffer);
872 return -ENOMEM;
873 }
874
875 static int uprobe_buffer_enable(void)
876 {
877 int ret = 0;
878
879 BUG_ON(!mutex_is_locked(&event_mutex));
880
881 if (uprobe_buffer_refcnt++ == 0) {
882 ret = uprobe_buffer_init();
883 if (ret < 0)
884 uprobe_buffer_refcnt--;
885 }
886
887 return ret;
888 }
889
890 static void uprobe_buffer_disable(void)
891 {
892 int cpu;
893
894 BUG_ON(!mutex_is_locked(&event_mutex));
895
896 if (--uprobe_buffer_refcnt == 0) {
897 for_each_possible_cpu(cpu)
898 free_page((unsigned long)per_cpu_ptr(uprobe_cpu_buffer,
899 cpu)->buf);
900
901 free_percpu(uprobe_cpu_buffer);
902 uprobe_cpu_buffer = NULL;
903 }
904 }
905
906 static struct uprobe_cpu_buffer *uprobe_buffer_get(void)
907 {
908 struct uprobe_cpu_buffer *ucb;
909 int cpu;
910
911 cpu = raw_smp_processor_id();
912 ucb = per_cpu_ptr(uprobe_cpu_buffer, cpu);
913
914 /*
915 * Use per-cpu buffers for fastest access, but we might migrate
916 * so the mutex makes sure we have sole access to it.
917 */
918 mutex_lock(&ucb->mutex);
919
920 return ucb;
921 }
922
923 static void uprobe_buffer_put(struct uprobe_cpu_buffer *ucb)
924 {
925 mutex_unlock(&ucb->mutex);
926 }
927
928 static void __uprobe_trace_func(struct trace_uprobe *tu,
929 unsigned long func, struct pt_regs *regs,
930 struct uprobe_cpu_buffer *ucb, int dsize,
931 struct trace_event_file *trace_file)
932 {
933 struct uprobe_trace_entry_head *entry;
934 struct trace_buffer *buffer;
935 struct ring_buffer_event *event;
936 void *data;
937 int size, esize;
938 struct trace_event_call *call = trace_probe_event_call(&tu->tp);
939
940 WARN_ON(call != trace_file->event_call);
941
942 if (WARN_ON_ONCE(tu->tp.size + dsize > PAGE_SIZE))
943 return;
944
945 if (trace_trigger_soft_disabled(trace_file))
946 return;
947
948 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
949 size = esize + tu->tp.size + dsize;
950 event = trace_event_buffer_lock_reserve(&buffer, trace_file,
951 call->event.type, size, 0, 0);
952 if (!event)
953 return;
954
955 entry = ring_buffer_event_data(event);
956 if (is_ret_probe(tu)) {
957 entry->vaddr[0] = func;
958 entry->vaddr[1] = instruction_pointer(regs);
959 data = DATAOF_TRACE_ENTRY(entry, true);
960 } else {
961 entry->vaddr[0] = instruction_pointer(regs);
962 data = DATAOF_TRACE_ENTRY(entry, false);
963 }
964
965 memcpy(data, ucb->buf, tu->tp.size + dsize);
966
967 event_trigger_unlock_commit(trace_file, buffer, event, entry, 0, 0);
968 }
969
970 /* uprobe handler */
971 static int uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs,
972 struct uprobe_cpu_buffer *ucb, int dsize)
973 {
974 struct event_file_link *link;
975
976 if (is_ret_probe(tu))
977 return 0;
978
979 rcu_read_lock();
980 trace_probe_for_each_link_rcu(link, &tu->tp)
981 __uprobe_trace_func(tu, 0, regs, ucb, dsize, link->file);
982 rcu_read_unlock();
983
984 return 0;
985 }
986
987 static void uretprobe_trace_func(struct trace_uprobe *tu, unsigned long func,
988 struct pt_regs *regs,
989 struct uprobe_cpu_buffer *ucb, int dsize)
990 {
991 struct event_file_link *link;
992
993 rcu_read_lock();
994 trace_probe_for_each_link_rcu(link, &tu->tp)
995 __uprobe_trace_func(tu, func, regs, ucb, dsize, link->file);
996 rcu_read_unlock();
997 }
998
999 /* Event entry printers */
1000 static enum print_line_t
1001 print_uprobe_event(struct trace_iterator *iter, int flags, struct trace_event *event)
1002 {
1003 struct uprobe_trace_entry_head *entry;
1004 struct trace_seq *s = &iter->seq;
1005 struct trace_uprobe *tu;
1006 u8 *data;
1007
1008 entry = (struct uprobe_trace_entry_head *)iter->ent;
1009 tu = trace_uprobe_primary_from_call(
1010 container_of(event, struct trace_event_call, event));
1011 if (unlikely(!tu))
1012 goto out;
1013
1014 if (is_ret_probe(tu)) {
1015 trace_seq_printf(s, "%s: (0x%lx <- 0x%lx)",
1016 trace_probe_name(&tu->tp),
1017 entry->vaddr[1], entry->vaddr[0]);
1018 data = DATAOF_TRACE_ENTRY(entry, true);
1019 } else {
1020 trace_seq_printf(s, "%s: (0x%lx)",
1021 trace_probe_name(&tu->tp),
1022 entry->vaddr[0]);
1023 data = DATAOF_TRACE_ENTRY(entry, false);
1024 }
1025
1026 if (print_probe_args(s, tu->tp.args, tu->tp.nr_args, data, entry) < 0)
1027 goto out;
1028
1029 trace_seq_putc(s, '\n');
1030
1031 out:
1032 return trace_handle_return(s);
1033 }
1034
1035 typedef bool (*filter_func_t)(struct uprobe_consumer *self,
1036 enum uprobe_filter_ctx ctx,
1037 struct mm_struct *mm);
1038
1039 static int trace_uprobe_enable(struct trace_uprobe *tu, filter_func_t filter)
1040 {
1041 int ret;
1042
1043 tu->consumer.filter = filter;
1044 tu->inode = d_real_inode(tu->path.dentry);
1045
1046 if (tu->ref_ctr_offset)
1047 ret = uprobe_register_refctr(tu->inode, tu->offset,
1048 tu->ref_ctr_offset, &tu->consumer);
1049 else
1050 ret = uprobe_register(tu->inode, tu->offset, &tu->consumer);
1051
1052 if (ret)
1053 tu->inode = NULL;
1054
1055 return ret;
1056 }
1057
1058 static void __probe_event_disable(struct trace_probe *tp)
1059 {
1060 struct trace_probe *pos;
1061 struct trace_uprobe *tu;
1062
1063 tu = container_of(tp, struct trace_uprobe, tp);
1064 WARN_ON(!uprobe_filter_is_empty(tu->tp.event->filter));
1065
1066 list_for_each_entry(pos, trace_probe_probe_list(tp), list) {
1067 tu = container_of(pos, struct trace_uprobe, tp);
1068 if (!tu->inode)
1069 continue;
1070
1071 uprobe_unregister(tu->inode, tu->offset, &tu->consumer);
1072 tu->inode = NULL;
1073 }
1074 }
1075
1076 static int probe_event_enable(struct trace_event_call *call,
1077 struct trace_event_file *file, filter_func_t filter)
1078 {
1079 struct trace_probe *pos, *tp;
1080 struct trace_uprobe *tu;
1081 bool enabled;
1082 int ret;
1083
1084 tp = trace_probe_primary_from_call(call);
1085 if (WARN_ON_ONCE(!tp))
1086 return -ENODEV;
1087 enabled = trace_probe_is_enabled(tp);
1088
1089 /* This may also change "enabled" state */
1090 if (file) {
1091 if (trace_probe_test_flag(tp, TP_FLAG_PROFILE))
1092 return -EINTR;
1093
1094 ret = trace_probe_add_file(tp, file);
1095 if (ret < 0)
1096 return ret;
1097 } else {
1098 if (trace_probe_test_flag(tp, TP_FLAG_TRACE))
1099 return -EINTR;
1100
1101 trace_probe_set_flag(tp, TP_FLAG_PROFILE);
1102 }
1103
1104 tu = container_of(tp, struct trace_uprobe, tp);
1105 WARN_ON(!uprobe_filter_is_empty(tu->tp.event->filter));
1106
1107 if (enabled)
1108 return 0;
1109
1110 ret = uprobe_buffer_enable();
1111 if (ret)
1112 goto err_flags;
1113
1114 list_for_each_entry(pos, trace_probe_probe_list(tp), list) {
1115 tu = container_of(pos, struct trace_uprobe, tp);
1116 ret = trace_uprobe_enable(tu, filter);
1117 if (ret) {
1118 __probe_event_disable(tp);
1119 goto err_buffer;
1120 }
1121 }
1122
1123 return 0;
1124
1125 err_buffer:
1126 uprobe_buffer_disable();
1127
1128 err_flags:
1129 if (file)
1130 trace_probe_remove_file(tp, file);
1131 else
1132 trace_probe_clear_flag(tp, TP_FLAG_PROFILE);
1133
1134 return ret;
1135 }
1136
1137 static void probe_event_disable(struct trace_event_call *call,
1138 struct trace_event_file *file)
1139 {
1140 struct trace_probe *tp;
1141
1142 tp = trace_probe_primary_from_call(call);
1143 if (WARN_ON_ONCE(!tp))
1144 return;
1145
1146 if (!trace_probe_is_enabled(tp))
1147 return;
1148
1149 if (file) {
1150 if (trace_probe_remove_file(tp, file) < 0)
1151 return;
1152
1153 if (trace_probe_is_enabled(tp))
1154 return;
1155 } else
1156 trace_probe_clear_flag(tp, TP_FLAG_PROFILE);
1157
1158 __probe_event_disable(tp);
1159 uprobe_buffer_disable();
1160 }
1161
1162 static int uprobe_event_define_fields(struct trace_event_call *event_call)
1163 {
1164 int ret, size;
1165 struct uprobe_trace_entry_head field;
1166 struct trace_uprobe *tu;
1167
1168 tu = trace_uprobe_primary_from_call(event_call);
1169 if (unlikely(!tu))
1170 return -ENODEV;
1171
1172 if (is_ret_probe(tu)) {
1173 DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_FUNC, 0);
1174 DEFINE_FIELD(unsigned long, vaddr[1], FIELD_STRING_RETIP, 0);
1175 size = SIZEOF_TRACE_ENTRY(true);
1176 } else {
1177 DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_IP, 0);
1178 size = SIZEOF_TRACE_ENTRY(false);
1179 }
1180
1181 return traceprobe_define_arg_fields(event_call, size, &tu->tp);
1182 }
1183
1184 #ifdef CONFIG_PERF_EVENTS
1185 static bool
1186 __uprobe_perf_filter(struct trace_uprobe_filter *filter, struct mm_struct *mm)
1187 {
1188 struct perf_event *event;
1189
1190 if (filter->nr_systemwide)
1191 return true;
1192
1193 list_for_each_entry(event, &filter->perf_events, hw.tp_list) {
1194 if (event->hw.target->mm == mm)
1195 return true;
1196 }
1197
1198 return false;
1199 }
1200
1201 static inline bool
1202 trace_uprobe_filter_event(struct trace_uprobe_filter *filter,
1203 struct perf_event *event)
1204 {
1205 return __uprobe_perf_filter(filter, event->hw.target->mm);
1206 }
1207
1208 static bool trace_uprobe_filter_remove(struct trace_uprobe_filter *filter,
1209 struct perf_event *event)
1210 {
1211 bool done;
1212
1213 write_lock(&filter->rwlock);
1214 if (event->hw.target) {
1215 list_del(&event->hw.tp_list);
1216 done = filter->nr_systemwide ||
1217 (event->hw.target->flags & PF_EXITING) ||
1218 trace_uprobe_filter_event(filter, event);
1219 } else {
1220 filter->nr_systemwide--;
1221 done = filter->nr_systemwide;
1222 }
1223 write_unlock(&filter->rwlock);
1224
1225 return done;
1226 }
1227
1228 /* This returns true if the filter always covers target mm */
1229 static bool trace_uprobe_filter_add(struct trace_uprobe_filter *filter,
1230 struct perf_event *event)
1231 {
1232 bool done;
1233
1234 write_lock(&filter->rwlock);
1235 if (event->hw.target) {
1236 /*
1237 * event->parent != NULL means copy_process(), we can avoid
1238 * uprobe_apply(). current->mm must be probed and we can rely
1239 * on dup_mmap() which preserves the already installed bp's.
1240 *
1241 * attr.enable_on_exec means that exec/mmap will install the
1242 * breakpoints we need.
1243 */
1244 done = filter->nr_systemwide ||
1245 event->parent || event->attr.enable_on_exec ||
1246 trace_uprobe_filter_event(filter, event);
1247 list_add(&event->hw.tp_list, &filter->perf_events);
1248 } else {
1249 done = filter->nr_systemwide;
1250 filter->nr_systemwide++;
1251 }
1252 write_unlock(&filter->rwlock);
1253
1254 return done;
1255 }
1256
1257 static int uprobe_perf_close(struct trace_event_call *call,
1258 struct perf_event *event)
1259 {
1260 struct trace_probe *pos, *tp;
1261 struct trace_uprobe *tu;
1262 int ret = 0;
1263
1264 tp = trace_probe_primary_from_call(call);
1265 if (WARN_ON_ONCE(!tp))
1266 return -ENODEV;
1267
1268 tu = container_of(tp, struct trace_uprobe, tp);
1269 if (trace_uprobe_filter_remove(tu->tp.event->filter, event))
1270 return 0;
1271
1272 list_for_each_entry(pos, trace_probe_probe_list(tp), list) {
1273 tu = container_of(pos, struct trace_uprobe, tp);
1274 ret = uprobe_apply(tu->inode, tu->offset, &tu->consumer, false);
1275 if (ret)
1276 break;
1277 }
1278
1279 return ret;
1280 }
1281
1282 static int uprobe_perf_open(struct trace_event_call *call,
1283 struct perf_event *event)
1284 {
1285 struct trace_probe *pos, *tp;
1286 struct trace_uprobe *tu;
1287 int err = 0;
1288
1289 tp = trace_probe_primary_from_call(call);
1290 if (WARN_ON_ONCE(!tp))
1291 return -ENODEV;
1292
1293 tu = container_of(tp, struct trace_uprobe, tp);
1294 if (trace_uprobe_filter_add(tu->tp.event->filter, event))
1295 return 0;
1296
1297 list_for_each_entry(pos, trace_probe_probe_list(tp), list) {
1298 err = uprobe_apply(tu->inode, tu->offset, &tu->consumer, true);
1299 if (err) {
1300 uprobe_perf_close(call, event);
1301 break;
1302 }
1303 }
1304
1305 return err;
1306 }
1307
1308 static bool uprobe_perf_filter(struct uprobe_consumer *uc,
1309 enum uprobe_filter_ctx ctx, struct mm_struct *mm)
1310 {
1311 struct trace_uprobe_filter *filter;
1312 struct trace_uprobe *tu;
1313 int ret;
1314
1315 tu = container_of(uc, struct trace_uprobe, consumer);
1316 filter = tu->tp.event->filter;
1317
1318 read_lock(&filter->rwlock);
1319 ret = __uprobe_perf_filter(filter, mm);
1320 read_unlock(&filter->rwlock);
1321
1322 return ret;
1323 }
1324
1325 static void __uprobe_perf_func(struct trace_uprobe *tu,
1326 unsigned long func, struct pt_regs *regs,
1327 struct uprobe_cpu_buffer *ucb, int dsize)
1328 {
1329 struct trace_event_call *call = trace_probe_event_call(&tu->tp);
1330 struct uprobe_trace_entry_head *entry;
1331 struct hlist_head *head;
1332 void *data;
1333 int size, esize;
1334 int rctx;
1335
1336 if (bpf_prog_array_valid(call)) {
1337 u32 ret;
1338
1339 preempt_disable();
1340 ret = trace_call_bpf(call, regs);
1341 preempt_enable();
1342 if (!ret)
1343 return;
1344 }
1345
1346 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
1347
1348 size = esize + tu->tp.size + dsize;
1349 size = ALIGN(size + sizeof(u32), sizeof(u64)) - sizeof(u32);
1350 if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, "profile buffer not large enough"))
1351 return;
1352
1353 preempt_disable();
1354 head = this_cpu_ptr(call->perf_events);
1355 if (hlist_empty(head))
1356 goto out;
1357
1358 entry = perf_trace_buf_alloc(size, NULL, &rctx);
1359 if (!entry)
1360 goto out;
1361
1362 if (is_ret_probe(tu)) {
1363 entry->vaddr[0] = func;
1364 entry->vaddr[1] = instruction_pointer(regs);
1365 data = DATAOF_TRACE_ENTRY(entry, true);
1366 } else {
1367 entry->vaddr[0] = instruction_pointer(regs);
1368 data = DATAOF_TRACE_ENTRY(entry, false);
1369 }
1370
1371 memcpy(data, ucb->buf, tu->tp.size + dsize);
1372
1373 if (size - esize > tu->tp.size + dsize) {
1374 int len = tu->tp.size + dsize;
1375
1376 memset(data + len, 0, size - esize - len);
1377 }
1378
1379 perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs,
1380 head, NULL);
1381 out:
1382 preempt_enable();
1383 }
1384
1385 /* uprobe profile handler */
1386 static int uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs,
1387 struct uprobe_cpu_buffer *ucb, int dsize)
1388 {
1389 if (!uprobe_perf_filter(&tu->consumer, 0, current->mm))
1390 return UPROBE_HANDLER_REMOVE;
1391
1392 if (!is_ret_probe(tu))
1393 __uprobe_perf_func(tu, 0, regs, ucb, dsize);
1394 return 0;
1395 }
1396
1397 static void uretprobe_perf_func(struct trace_uprobe *tu, unsigned long func,
1398 struct pt_regs *regs,
1399 struct uprobe_cpu_buffer *ucb, int dsize)
1400 {
1401 __uprobe_perf_func(tu, func, regs, ucb, dsize);
1402 }
1403
1404 int bpf_get_uprobe_info(const struct perf_event *event, u32 *fd_type,
1405 const char **filename, u64 *probe_offset,
1406 bool perf_type_tracepoint)
1407 {
1408 const char *pevent = trace_event_name(event->tp_event);
1409 const char *group = event->tp_event->class->system;
1410 struct trace_uprobe *tu;
1411
1412 if (perf_type_tracepoint)
1413 tu = find_probe_event(pevent, group);
1414 else
1415 tu = trace_uprobe_primary_from_call(event->tp_event);
1416 if (!tu)
1417 return -EINVAL;
1418
1419 *fd_type = is_ret_probe(tu) ? BPF_FD_TYPE_URETPROBE
1420 : BPF_FD_TYPE_UPROBE;
1421 *filename = tu->filename;
1422 *probe_offset = tu->offset;
1423 return 0;
1424 }
1425 #endif /* CONFIG_PERF_EVENTS */
1426
1427 static int
1428 trace_uprobe_register(struct trace_event_call *event, enum trace_reg type,
1429 void *data)
1430 {
1431 struct trace_event_file *file = data;
1432
1433 switch (type) {
1434 case TRACE_REG_REGISTER:
1435 return probe_event_enable(event, file, NULL);
1436
1437 case TRACE_REG_UNREGISTER:
1438 probe_event_disable(event, file);
1439 return 0;
1440
1441 #ifdef CONFIG_PERF_EVENTS
1442 case TRACE_REG_PERF_REGISTER:
1443 return probe_event_enable(event, NULL, uprobe_perf_filter);
1444
1445 case TRACE_REG_PERF_UNREGISTER:
1446 probe_event_disable(event, NULL);
1447 return 0;
1448
1449 case TRACE_REG_PERF_OPEN:
1450 return uprobe_perf_open(event, data);
1451
1452 case TRACE_REG_PERF_CLOSE:
1453 return uprobe_perf_close(event, data);
1454
1455 #endif
1456 default:
1457 return 0;
1458 }
1459 return 0;
1460 }
1461
1462 static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs)
1463 {
1464 struct trace_uprobe *tu;
1465 struct uprobe_dispatch_data udd;
1466 struct uprobe_cpu_buffer *ucb;
1467 int dsize, esize;
1468 int ret = 0;
1469
1470
1471 tu = container_of(con, struct trace_uprobe, consumer);
1472 tu->nhit++;
1473
1474 udd.tu = tu;
1475 udd.bp_addr = instruction_pointer(regs);
1476
1477 current->utask->vaddr = (unsigned long) &udd;
1478
1479 if (WARN_ON_ONCE(!uprobe_cpu_buffer))
1480 return 0;
1481
1482 dsize = __get_data_size(&tu->tp, regs);
1483 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
1484
1485 ucb = uprobe_buffer_get();
1486 store_trace_args(ucb->buf, &tu->tp, regs, esize, dsize);
1487
1488 if (trace_probe_test_flag(&tu->tp, TP_FLAG_TRACE))
1489 ret |= uprobe_trace_func(tu, regs, ucb, dsize);
1490
1491 #ifdef CONFIG_PERF_EVENTS
1492 if (trace_probe_test_flag(&tu->tp, TP_FLAG_PROFILE))
1493 ret |= uprobe_perf_func(tu, regs, ucb, dsize);
1494 #endif
1495 uprobe_buffer_put(ucb);
1496 return ret;
1497 }
1498
1499 static int uretprobe_dispatcher(struct uprobe_consumer *con,
1500 unsigned long func, struct pt_regs *regs)
1501 {
1502 struct trace_uprobe *tu;
1503 struct uprobe_dispatch_data udd;
1504 struct uprobe_cpu_buffer *ucb;
1505 int dsize, esize;
1506
1507 tu = container_of(con, struct trace_uprobe, consumer);
1508
1509 udd.tu = tu;
1510 udd.bp_addr = func;
1511
1512 current->utask->vaddr = (unsigned long) &udd;
1513
1514 if (WARN_ON_ONCE(!uprobe_cpu_buffer))
1515 return 0;
1516
1517 dsize = __get_data_size(&tu->tp, regs);
1518 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
1519
1520 ucb = uprobe_buffer_get();
1521 store_trace_args(ucb->buf, &tu->tp, regs, esize, dsize);
1522
1523 if (trace_probe_test_flag(&tu->tp, TP_FLAG_TRACE))
1524 uretprobe_trace_func(tu, func, regs, ucb, dsize);
1525
1526 #ifdef CONFIG_PERF_EVENTS
1527 if (trace_probe_test_flag(&tu->tp, TP_FLAG_PROFILE))
1528 uretprobe_perf_func(tu, func, regs, ucb, dsize);
1529 #endif
1530 uprobe_buffer_put(ucb);
1531 return 0;
1532 }
1533
1534 static struct trace_event_functions uprobe_funcs = {
1535 .trace = print_uprobe_event
1536 };
1537
1538 static struct trace_event_fields uprobe_fields_array[] = {
1539 { .type = TRACE_FUNCTION_TYPE,
1540 .define_fields = uprobe_event_define_fields },
1541 {}
1542 };
1543
1544 static inline void init_trace_event_call(struct trace_uprobe *tu)
1545 {
1546 struct trace_event_call *call = trace_probe_event_call(&tu->tp);
1547 call->event.funcs = &uprobe_funcs;
1548 call->class->fields_array = uprobe_fields_array;
1549
1550 call->flags = TRACE_EVENT_FL_UPROBE | TRACE_EVENT_FL_CAP_ANY;
1551 call->class->reg = trace_uprobe_register;
1552 }
1553
1554 static int register_uprobe_event(struct trace_uprobe *tu)
1555 {
1556 init_trace_event_call(tu);
1557
1558 return trace_probe_register_event_call(&tu->tp);
1559 }
1560
1561 static int unregister_uprobe_event(struct trace_uprobe *tu)
1562 {
1563 return trace_probe_unregister_event_call(&tu->tp);
1564 }
1565
1566 #ifdef CONFIG_PERF_EVENTS
1567 struct trace_event_call *
1568 create_local_trace_uprobe(char *name, unsigned long offs,
1569 unsigned long ref_ctr_offset, bool is_return)
1570 {
1571 struct trace_uprobe *tu;
1572 struct path path;
1573 int ret;
1574
1575 ret = kern_path(name, LOOKUP_FOLLOW, &path);
1576 if (ret)
1577 return ERR_PTR(ret);
1578
1579 if (!d_is_reg(path.dentry)) {
1580 path_put(&path);
1581 return ERR_PTR(-EINVAL);
1582 }
1583
1584 /*
1585 * local trace_kprobes are not added to dyn_event, so they are never
1586 * searched in find_trace_kprobe(). Therefore, there is no concern of
1587 * duplicated name "DUMMY_EVENT" here.
1588 */
1589 tu = alloc_trace_uprobe(UPROBE_EVENT_SYSTEM, "DUMMY_EVENT", 0,
1590 is_return);
1591
1592 if (IS_ERR(tu)) {
1593 pr_info("Failed to allocate trace_uprobe.(%d)\n",
1594 (int)PTR_ERR(tu));
1595 path_put(&path);
1596 return ERR_CAST(tu);
1597 }
1598
1599 tu->offset = offs;
1600 tu->path = path;
1601 tu->ref_ctr_offset = ref_ctr_offset;
1602 tu->filename = kstrdup(name, GFP_KERNEL);
1603 init_trace_event_call(tu);
1604
1605 if (traceprobe_set_print_fmt(&tu->tp, is_ret_probe(tu)) < 0) {
1606 ret = -ENOMEM;
1607 goto error;
1608 }
1609
1610 return trace_probe_event_call(&tu->tp);
1611 error:
1612 free_trace_uprobe(tu);
1613 return ERR_PTR(ret);
1614 }
1615
1616 void destroy_local_trace_uprobe(struct trace_event_call *event_call)
1617 {
1618 struct trace_uprobe *tu;
1619
1620 tu = trace_uprobe_primary_from_call(event_call);
1621
1622 free_trace_uprobe(tu);
1623 }
1624 #endif /* CONFIG_PERF_EVENTS */
1625
1626 /* Make a trace interface for controling probe points */
1627 static __init int init_uprobe_trace(void)
1628 {
1629 struct dentry *d_tracer;
1630 int ret;
1631
1632 ret = dyn_event_register(&trace_uprobe_ops);
1633 if (ret)
1634 return ret;
1635
1636 d_tracer = tracing_init_dentry();
1637 if (IS_ERR(d_tracer))
1638 return 0;
1639
1640 trace_create_file("uprobe_events", 0644, d_tracer,
1641 NULL, &uprobe_events_ops);
1642 /* Profile interface */
1643 trace_create_file("uprobe_profile", 0444, d_tracer,
1644 NULL, &uprobe_profile_ops);
1645 return 0;
1646 }
1647
1648 fs_initcall(init_uprobe_trace);
Linux with added FPC-III support