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/bpf-cgroup.h>
11 #include <linux/security.h>
12 #include <linux/ctype.h>
13 #include <linux/module.h>
14 #include <linux/uaccess.h>
15 #include <linux/uprobes.h>
16 #include <linux/namei.h>
17 #include <linux/string.h>
18 #include <linux/rculist.h>
19 #include <linux/filter.h>
20
21 #include "trace_dynevent.h"
22 #include "trace_probe.h"
23 #include "trace_probe_tmpl.h"
24
25 #define UPROBE_EVENT_SYSTEM "uprobes"
26
27 struct uprobe_trace_entry_head {
28 struct trace_entry ent;
29 unsigned long vaddr[];
30 };
31
32 #define SIZEOF_TRACE_ENTRY(is_return) \
33 (sizeof(struct uprobe_trace_entry_head) + \
34 sizeof(unsigned long) * (is_return ? 2 : 1))
35
36 #define DATAOF_TRACE_ENTRY(entry, is_return) \
37 ((void*)(entry) + SIZEOF_TRACE_ENTRY(is_return))
38
39 static int trace_uprobe_create(const char *raw_command);
40 static int trace_uprobe_show(struct seq_file *m, struct dyn_event *ev);
41 static int trace_uprobe_release(struct dyn_event *ev);
42 static bool trace_uprobe_is_busy(struct dyn_event *ev);
43 static bool trace_uprobe_match(const char *system, const char *event,
44 int argc, const char **argv, struct dyn_event *ev);
45
46 static struct dyn_event_operations trace_uprobe_ops = {
47 .create = trace_uprobe_create,
48 .show = trace_uprobe_show,
49 .is_busy = trace_uprobe_is_busy,
50 .free = trace_uprobe_release,
51 .match = trace_uprobe_match,
52 };
53
54 /*
55 * uprobe event core functions
56 */
57 struct trace_uprobe {
58 struct dyn_event devent;
59 struct uprobe_consumer consumer;
60 struct path path;
61 struct inode *inode;
62 char *filename;
63 unsigned long offset;
64 unsigned long ref_ctr_offset;
65 unsigned long nhit;
66 struct trace_probe tp;
67 };
68
69 static bool is_trace_uprobe(struct dyn_event *ev)
70 {
71 return ev->ops == &trace_uprobe_ops;
72 }
73
74 static struct trace_uprobe *to_trace_uprobe(struct dyn_event *ev)
75 {
76 return container_of(ev, struct trace_uprobe, devent);
77 }
78
79 /**
80 * for_each_trace_uprobe - iterate over the trace_uprobe list
81 * @pos: the struct trace_uprobe * for each entry
82 * @dpos: the struct dyn_event * to use as a loop cursor
83 */
84 #define for_each_trace_uprobe(pos, dpos) \
85 for_each_dyn_event(dpos) \
86 if (is_trace_uprobe(dpos) && (pos = to_trace_uprobe(dpos)))
87
88 static int register_uprobe_event(struct trace_uprobe *tu);
89 static int unregister_uprobe_event(struct trace_uprobe *tu);
90
91 static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs);
92 static int uretprobe_dispatcher(struct uprobe_consumer *con,
93 unsigned long func, struct pt_regs *regs);
94
95 #ifdef CONFIG_STACK_GROWSUP
96 static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n)
97 {
98 return addr - (n * sizeof(long));
99 }
100 #else
101 static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n)
102 {
103 return addr + (n * sizeof(long));
104 }
105 #endif
106
107 static unsigned long get_user_stack_nth(struct pt_regs *regs, unsigned int n)
108 {
109 unsigned long ret;
110 unsigned long addr = user_stack_pointer(regs);
111
112 addr = adjust_stack_addr(addr, n);
113
114 if (copy_from_user(&ret, (void __force __user *) addr, sizeof(ret)))
115 return 0;
116
117 return ret;
118 }
119
120 /*
121 * Uprobes-specific fetch functions
122 */
123 static nokprobe_inline int
124 probe_mem_read(void *dest, void *src, size_t size)
125 {
126 void __user *vaddr = (void __force __user *)src;
127
128 return copy_from_user(dest, vaddr, size) ? -EFAULT : 0;
129 }
130
131 static nokprobe_inline int
132 probe_mem_read_user(void *dest, void *src, size_t size)
133 {
134 return probe_mem_read(dest, src, size);
135 }
136
137 /*
138 * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max
139 * length and relative data location.
140 */
141 static nokprobe_inline int
142 fetch_store_string(unsigned long addr, void *dest, void *base)
143 {
144 long ret;
145 u32 loc = *(u32 *)dest;
146 int maxlen = get_loc_len(loc);
147 u8 *dst = get_loc_data(dest, base);
148 void __user *src = (void __force __user *) addr;
149
150 if (unlikely(!maxlen))
151 return -ENOMEM;
152
153 if (addr == FETCH_TOKEN_COMM)
154 ret = strscpy(dst, current->comm, maxlen);
155 else
156 ret = strncpy_from_user(dst, src, maxlen);
157 if (ret >= 0) {
158 if (ret == maxlen)
159 dst[ret - 1] = '\0';
160 else
161 /*
162 * Include the terminating null byte. In this case it
163 * was copied by strncpy_from_user but not accounted
164 * for in ret.
165 */
166 ret++;
167 *(u32 *)dest = make_data_loc(ret, (void *)dst - base);
168 } else
169 *(u32 *)dest = make_data_loc(0, (void *)dst - base);
170
171 return ret;
172 }
173
174 static nokprobe_inline int
175 fetch_store_string_user(unsigned long addr, void *dest, void *base)
176 {
177 return fetch_store_string(addr, dest, base);
178 }
179
180 /* Return the length of string -- including null terminal byte */
181 static nokprobe_inline int
182 fetch_store_strlen(unsigned long addr)
183 {
184 int len;
185 void __user *vaddr = (void __force __user *) addr;
186
187 if (addr == FETCH_TOKEN_COMM)
188 len = strlen(current->comm) + 1;
189 else
190 len = strnlen_user(vaddr, MAX_STRING_SIZE);
191
192 return (len > MAX_STRING_SIZE) ? 0 : len;
193 }
194
195 static nokprobe_inline int
196 fetch_store_strlen_user(unsigned long addr)
197 {
198 return fetch_store_strlen(addr);
199 }
200
201 static unsigned long translate_user_vaddr(unsigned long file_offset)
202 {
203 unsigned long base_addr;
204 struct uprobe_dispatch_data *udd;
205
206 udd = (void *) current->utask->vaddr;
207
208 base_addr = udd->bp_addr - udd->tu->offset;
209 return base_addr + file_offset;
210 }
211
212 /* Note that we don't verify it, since the code does not come from user space */
213 static int
214 process_fetch_insn(struct fetch_insn *code, void *rec, void *edata,
215 void *dest, void *base)
216 {
217 struct pt_regs *regs = rec;
218 unsigned long val;
219 int ret;
220
221 /* 1st stage: get value from context */
222 switch (code->op) {
223 case FETCH_OP_REG:
224 val = regs_get_register(regs, code->param);
225 break;
226 case FETCH_OP_STACK:
227 val = get_user_stack_nth(regs, code->param);
228 break;
229 case FETCH_OP_STACKP:
230 val = user_stack_pointer(regs);
231 break;
232 case FETCH_OP_RETVAL:
233 val = regs_return_value(regs);
234 break;
235 case FETCH_OP_COMM:
236 val = FETCH_TOKEN_COMM;
237 break;
238 case FETCH_OP_FOFFS:
239 val = translate_user_vaddr(code->immediate);
240 break;
241 default:
242 ret = process_common_fetch_insn(code, &val);
243 if (ret < 0)
244 return ret;
245 }
246 code++;
247
248 return process_fetch_insn_bottom(code, val, dest, base);
249 }
250 NOKPROBE_SYMBOL(process_fetch_insn)
251
252 static inline void init_trace_uprobe_filter(struct trace_uprobe_filter *filter)
253 {
254 rwlock_init(&filter->rwlock);
255 filter->nr_systemwide = 0;
256 INIT_LIST_HEAD(&filter->perf_events);
257 }
258
259 static inline bool uprobe_filter_is_empty(struct trace_uprobe_filter *filter)
260 {
261 return !filter->nr_systemwide && list_empty(&filter->perf_events);
262 }
263
264 static inline bool is_ret_probe(struct trace_uprobe *tu)
265 {
266 return tu->consumer.ret_handler != NULL;
267 }
268
269 static bool trace_uprobe_is_busy(struct dyn_event *ev)
270 {
271 struct trace_uprobe *tu = to_trace_uprobe(ev);
272
273 return trace_probe_is_enabled(&tu->tp);
274 }
275
276 static bool trace_uprobe_match_command_head(struct trace_uprobe *tu,
277 int argc, const char **argv)
278 {
279 char buf[MAX_ARGSTR_LEN + 1];
280 int len;
281
282 if (!argc)
283 return true;
284
285 len = strlen(tu->filename);
286 if (strncmp(tu->filename, argv[0], len) || argv[0][len] != ':')
287 return false;
288
289 if (tu->ref_ctr_offset == 0)
290 snprintf(buf, sizeof(buf), "0x%0*lx",
291 (int)(sizeof(void *) * 2), tu->offset);
292 else
293 snprintf(buf, sizeof(buf), "0x%0*lx(0x%lx)",
294 (int)(sizeof(void *) * 2), tu->offset,
295 tu->ref_ctr_offset);
296 if (strcmp(buf, &argv[0][len + 1]))
297 return false;
298
299 argc--; argv++;
300
301 return trace_probe_match_command_args(&tu->tp, argc, argv);
302 }
303
304 static bool trace_uprobe_match(const char *system, const char *event,
305 int argc, const char **argv, struct dyn_event *ev)
306 {
307 struct trace_uprobe *tu = to_trace_uprobe(ev);
308
309 return (event[0] == '\0' ||
310 strcmp(trace_probe_name(&tu->tp), event) == 0) &&
311 (!system || strcmp(trace_probe_group_name(&tu->tp), system) == 0) &&
312 trace_uprobe_match_command_head(tu, argc, argv);
313 }
314
315 static nokprobe_inline struct trace_uprobe *
316 trace_uprobe_primary_from_call(struct trace_event_call *call)
317 {
318 struct trace_probe *tp;
319
320 tp = trace_probe_primary_from_call(call);
321 if (WARN_ON_ONCE(!tp))
322 return NULL;
323
324 return container_of(tp, struct trace_uprobe, tp);
325 }
326
327 /*
328 * Allocate new trace_uprobe and initialize it (including uprobes).
329 */
330 static struct trace_uprobe *
331 alloc_trace_uprobe(const char *group, const char *event, int nargs, bool is_ret)
332 {
333 struct trace_uprobe *tu;
334 int ret;
335
336 tu = kzalloc(struct_size(tu, tp.args, nargs), GFP_KERNEL);
337 if (!tu)
338 return ERR_PTR(-ENOMEM);
339
340 ret = trace_probe_init(&tu->tp, event, group, true, nargs);
341 if (ret < 0)
342 goto error;
343
344 dyn_event_init(&tu->devent, &trace_uprobe_ops);
345 tu->consumer.handler = uprobe_dispatcher;
346 if (is_ret)
347 tu->consumer.ret_handler = uretprobe_dispatcher;
348 init_trace_uprobe_filter(tu->tp.event->filter);
349 return tu;
350
351 error:
352 kfree(tu);
353
354 return ERR_PTR(ret);
355 }
356
357 static void free_trace_uprobe(struct trace_uprobe *tu)
358 {
359 if (!tu)
360 return;
361
362 path_put(&tu->path);
363 trace_probe_cleanup(&tu->tp);
364 kfree(tu->filename);
365 kfree(tu);
366 }
367
368 static struct trace_uprobe *find_probe_event(const char *event, const char *group)
369 {
370 struct dyn_event *pos;
371 struct trace_uprobe *tu;
372
373 for_each_trace_uprobe(tu, pos)
374 if (strcmp(trace_probe_name(&tu->tp), event) == 0 &&
375 strcmp(trace_probe_group_name(&tu->tp), group) == 0)
376 return tu;
377
378 return NULL;
379 }
380
381 /* Unregister a trace_uprobe and probe_event */
382 static int unregister_trace_uprobe(struct trace_uprobe *tu)
383 {
384 int ret;
385
386 if (trace_probe_has_sibling(&tu->tp))
387 goto unreg;
388
389 /* If there's a reference to the dynamic event */
390 if (trace_event_dyn_busy(trace_probe_event_call(&tu->tp)))
391 return -EBUSY;
392
393 ret = unregister_uprobe_event(tu);
394 if (ret)
395 return ret;
396
397 unreg:
398 dyn_event_remove(&tu->devent);
399 trace_probe_unlink(&tu->tp);
400 free_trace_uprobe(tu);
401 return 0;
402 }
403
404 static bool trace_uprobe_has_same_uprobe(struct trace_uprobe *orig,
405 struct trace_uprobe *comp)
406 {
407 struct trace_probe_event *tpe = orig->tp.event;
408 struct inode *comp_inode = d_real_inode(comp->path.dentry);
409 int i;
410
411 list_for_each_entry(orig, &tpe->probes, tp.list) {
412 if (comp_inode != d_real_inode(orig->path.dentry) ||
413 comp->offset != orig->offset)
414 continue;
415
416 /*
417 * trace_probe_compare_arg_type() ensured that nr_args and
418 * each argument name and type are same. Let's compare comm.
419 */
420 for (i = 0; i < orig->tp.nr_args; i++) {
421 if (strcmp(orig->tp.args[i].comm,
422 comp->tp.args[i].comm))
423 break;
424 }
425
426 if (i == orig->tp.nr_args)
427 return true;
428 }
429
430 return false;
431 }
432
433 static int append_trace_uprobe(struct trace_uprobe *tu, struct trace_uprobe *to)
434 {
435 int ret;
436
437 ret = trace_probe_compare_arg_type(&tu->tp, &to->tp);
438 if (ret) {
439 /* Note that argument starts index = 2 */
440 trace_probe_log_set_index(ret + 1);
441 trace_probe_log_err(0, DIFF_ARG_TYPE);
442 return -EEXIST;
443 }
444 if (trace_uprobe_has_same_uprobe(to, tu)) {
445 trace_probe_log_set_index(0);
446 trace_probe_log_err(0, SAME_PROBE);
447 return -EEXIST;
448 }
449
450 /* Append to existing event */
451 ret = trace_probe_append(&tu->tp, &to->tp);
452 if (!ret)
453 dyn_event_add(&tu->devent, trace_probe_event_call(&tu->tp));
454
455 return ret;
456 }
457
458 /*
459 * Uprobe with multiple reference counter is not allowed. i.e.
460 * If inode and offset matches, reference counter offset *must*
461 * match as well. Though, there is one exception: If user is
462 * replacing old trace_uprobe with new one(same group/event),
463 * then we allow same uprobe with new reference counter as far
464 * as the new one does not conflict with any other existing
465 * ones.
466 */
467 static int validate_ref_ctr_offset(struct trace_uprobe *new)
468 {
469 struct dyn_event *pos;
470 struct trace_uprobe *tmp;
471 struct inode *new_inode = d_real_inode(new->path.dentry);
472
473 for_each_trace_uprobe(tmp, pos) {
474 if (new_inode == d_real_inode(tmp->path.dentry) &&
475 new->offset == tmp->offset &&
476 new->ref_ctr_offset != tmp->ref_ctr_offset) {
477 pr_warn("Reference counter offset mismatch.");
478 return -EINVAL;
479 }
480 }
481 return 0;
482 }
483
484 /* Register a trace_uprobe and probe_event */
485 static int register_trace_uprobe(struct trace_uprobe *tu)
486 {
487 struct trace_uprobe *old_tu;
488 int ret;
489
490 mutex_lock(&event_mutex);
491
492 ret = validate_ref_ctr_offset(tu);
493 if (ret)
494 goto end;
495
496 /* register as an event */
497 old_tu = find_probe_event(trace_probe_name(&tu->tp),
498 trace_probe_group_name(&tu->tp));
499 if (old_tu) {
500 if (is_ret_probe(tu) != is_ret_probe(old_tu)) {
501 trace_probe_log_set_index(0);
502 trace_probe_log_err(0, DIFF_PROBE_TYPE);
503 ret = -EEXIST;
504 } else {
505 ret = append_trace_uprobe(tu, old_tu);
506 }
507 goto end;
508 }
509
510 ret = register_uprobe_event(tu);
511 if (ret) {
512 if (ret == -EEXIST) {
513 trace_probe_log_set_index(0);
514 trace_probe_log_err(0, EVENT_EXIST);
515 } else
516 pr_warn("Failed to register probe event(%d)\n", ret);
517 goto end;
518 }
519
520 dyn_event_add(&tu->devent, trace_probe_event_call(&tu->tp));
521
522 end:
523 mutex_unlock(&event_mutex);
524
525 return ret;
526 }
527
528 /*
529 * Argument syntax:
530 * - Add uprobe: p|r[:[GRP/][EVENT]] PATH:OFFSET[%return][(REF)] [FETCHARGS]
531 */
532 static int __trace_uprobe_create(int argc, const char **argv)
533 {
534 struct trace_uprobe *tu;
535 const char *event = NULL, *group = UPROBE_EVENT_SYSTEM;
536 char *arg, *filename, *rctr, *rctr_end, *tmp;
537 char buf[MAX_EVENT_NAME_LEN];
538 char gbuf[MAX_EVENT_NAME_LEN];
539 enum probe_print_type ptype;
540 struct path path;
541 unsigned long offset, ref_ctr_offset;
542 bool is_return = false;
543 int i, ret;
544
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 /* Check if there is %return suffix */
621 tmp = strchr(arg, '%');
622 if (tmp) {
623 if (!strcmp(tmp, "%return")) {
624 *tmp = '\0';
625 is_return = true;
626 } else {
627 trace_probe_log_err(tmp - filename, BAD_ADDR_SUFFIX);
628 ret = -EINVAL;
629 goto fail_address_parse;
630 }
631 }
632
633 /* Parse uprobe offset. */
634 ret = kstrtoul(arg, 0, &offset);
635 if (ret) {
636 trace_probe_log_err(arg - filename, BAD_UPROBE_OFFS);
637 goto fail_address_parse;
638 }
639
640 /* setup a probe */
641 trace_probe_log_set_index(0);
642 if (event) {
643 ret = traceprobe_parse_event_name(&event, &group, gbuf,
644 event - argv[0]);
645 if (ret)
646 goto fail_address_parse;
647 }
648
649 if (!event) {
650 char *tail;
651 char *ptr;
652
653 tail = kstrdup(kbasename(filename), GFP_KERNEL);
654 if (!tail) {
655 ret = -ENOMEM;
656 goto fail_address_parse;
657 }
658
659 ptr = strpbrk(tail, ".-_");
660 if (ptr)
661 *ptr = '\0';
662
663 snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_0x%lx", 'p', tail, offset);
664 event = buf;
665 kfree(tail);
666 }
667
668 argc -= 2;
669 argv += 2;
670
671 tu = alloc_trace_uprobe(group, event, argc, is_return);
672 if (IS_ERR(tu)) {
673 ret = PTR_ERR(tu);
674 /* This must return -ENOMEM otherwise there is a bug */
675 WARN_ON_ONCE(ret != -ENOMEM);
676 goto fail_address_parse;
677 }
678 tu->offset = offset;
679 tu->ref_ctr_offset = ref_ctr_offset;
680 tu->path = path;
681 tu->filename = filename;
682
683 /* parse arguments */
684 for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) {
685 struct traceprobe_parse_context ctx = {
686 .flags = (is_return ? TPARG_FL_RETURN : 0) | TPARG_FL_USER,
687 };
688
689 trace_probe_log_set_index(i + 2);
690 ret = traceprobe_parse_probe_arg(&tu->tp, i, argv[i], &ctx);
691 traceprobe_finish_parse(&ctx);
692 if (ret)
693 goto error;
694 }
695
696 ptype = is_ret_probe(tu) ? PROBE_PRINT_RETURN : PROBE_PRINT_NORMAL;
697 ret = traceprobe_set_print_fmt(&tu->tp, ptype);
698 if (ret < 0)
699 goto error;
700
701 ret = register_trace_uprobe(tu);
702 if (!ret)
703 goto out;
704
705 error:
706 free_trace_uprobe(tu);
707 out:
708 trace_probe_log_clear();
709 return ret;
710
711 fail_address_parse:
712 trace_probe_log_clear();
713 path_put(&path);
714 kfree(filename);
715
716 return ret;
717 }
718
719 int trace_uprobe_create(const char *raw_command)
720 {
721 return trace_probe_create(raw_command, __trace_uprobe_create);
722 }
723
724 static int create_or_delete_trace_uprobe(const char *raw_command)
725 {
726 int ret;
727
728 if (raw_command[0] == '-')
729 return dyn_event_release(raw_command, &trace_uprobe_ops);
730
731 ret = trace_uprobe_create(raw_command);
732 return ret == -ECANCELED ? -EINVAL : ret;
733 }
734
735 static int trace_uprobe_release(struct dyn_event *ev)
736 {
737 struct trace_uprobe *tu = to_trace_uprobe(ev);
738
739 return unregister_trace_uprobe(tu);
740 }
741
742 /* Probes listing interfaces */
743 static int trace_uprobe_show(struct seq_file *m, struct dyn_event *ev)
744 {
745 struct trace_uprobe *tu = to_trace_uprobe(ev);
746 char c = is_ret_probe(tu) ? 'r' : 'p';
747 int i;
748
749 seq_printf(m, "%c:%s/%s %s:0x%0*lx", c, trace_probe_group_name(&tu->tp),
750 trace_probe_name(&tu->tp), tu->filename,
751 (int)(sizeof(void *) * 2), tu->offset);
752
753 if (tu->ref_ctr_offset)
754 seq_printf(m, "(0x%lx)", tu->ref_ctr_offset);
755
756 for (i = 0; i < tu->tp.nr_args; i++)
757 seq_printf(m, " %s=%s", tu->tp.args[i].name, tu->tp.args[i].comm);
758
759 seq_putc(m, '\n');
760 return 0;
761 }
762
763 static int probes_seq_show(struct seq_file *m, void *v)
764 {
765 struct dyn_event *ev = v;
766
767 if (!is_trace_uprobe(ev))
768 return 0;
769
770 return trace_uprobe_show(m, ev);
771 }
772
773 static const struct seq_operations probes_seq_op = {
774 .start = dyn_event_seq_start,
775 .next = dyn_event_seq_next,
776 .stop = dyn_event_seq_stop,
777 .show = probes_seq_show
778 };
779
780 static int probes_open(struct inode *inode, struct file *file)
781 {
782 int ret;
783
784 ret = security_locked_down(LOCKDOWN_TRACEFS);
785 if (ret)
786 return ret;
787
788 if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
789 ret = dyn_events_release_all(&trace_uprobe_ops);
790 if (ret)
791 return ret;
792 }
793
794 return seq_open(file, &probes_seq_op);
795 }
796
797 static ssize_t probes_write(struct file *file, const char __user *buffer,
798 size_t count, loff_t *ppos)
799 {
800 return trace_parse_run_command(file, buffer, count, ppos,
801 create_or_delete_trace_uprobe);
802 }
803
804 static const struct file_operations uprobe_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
813 /* Probes profiling interfaces */
814 static int probes_profile_seq_show(struct seq_file *m, void *v)
815 {
816 struct dyn_event *ev = v;
817 struct trace_uprobe *tu;
818
819 if (!is_trace_uprobe(ev))
820 return 0;
821
822 tu = to_trace_uprobe(ev);
823 seq_printf(m, " %s %-44s %15lu\n", tu->filename,
824 trace_probe_name(&tu->tp), tu->nhit);
825 return 0;
826 }
827
828 static const struct seq_operations profile_seq_op = {
829 .start = dyn_event_seq_start,
830 .next = dyn_event_seq_next,
831 .stop = dyn_event_seq_stop,
832 .show = probes_profile_seq_show
833 };
834
835 static int profile_open(struct inode *inode, struct file *file)
836 {
837 int ret;
838
839 ret = security_locked_down(LOCKDOWN_TRACEFS);
840 if (ret)
841 return ret;
842
843 return seq_open(file, &profile_seq_op);
844 }
845
846 static const struct file_operations uprobe_profile_ops = {
847 .owner = THIS_MODULE,
848 .open = profile_open,
849 .read = seq_read,
850 .llseek = seq_lseek,
851 .release = seq_release,
852 };
853
854 struct uprobe_cpu_buffer {
855 struct mutex mutex;
856 void *buf;
857 int dsize;
858 };
859 static struct uprobe_cpu_buffer __percpu *uprobe_cpu_buffer;
860 static int uprobe_buffer_refcnt;
861
862 static int uprobe_buffer_init(void)
863 {
864 int cpu, err_cpu;
865
866 uprobe_cpu_buffer = alloc_percpu(struct uprobe_cpu_buffer);
867 if (uprobe_cpu_buffer == NULL)
868 return -ENOMEM;
869
870 for_each_possible_cpu(cpu) {
871 struct page *p = alloc_pages_node(cpu_to_node(cpu),
872 GFP_KERNEL, 0);
873 if (p == NULL) {
874 err_cpu = cpu;
875 goto err;
876 }
877 per_cpu_ptr(uprobe_cpu_buffer, cpu)->buf = page_address(p);
878 mutex_init(&per_cpu_ptr(uprobe_cpu_buffer, cpu)->mutex);
879 }
880
881 return 0;
882
883 err:
884 for_each_possible_cpu(cpu) {
885 if (cpu == err_cpu)
886 break;
887 free_page((unsigned long)per_cpu_ptr(uprobe_cpu_buffer, cpu)->buf);
888 }
889
890 free_percpu(uprobe_cpu_buffer);
891 return -ENOMEM;
892 }
893
894 static int uprobe_buffer_enable(void)
895 {
896 int ret = 0;
897
898 BUG_ON(!mutex_is_locked(&event_mutex));
899
900 if (uprobe_buffer_refcnt++ == 0) {
901 ret = uprobe_buffer_init();
902 if (ret < 0)
903 uprobe_buffer_refcnt--;
904 }
905
906 return ret;
907 }
908
909 static void uprobe_buffer_disable(void)
910 {
911 int cpu;
912
913 BUG_ON(!mutex_is_locked(&event_mutex));
914
915 if (--uprobe_buffer_refcnt == 0) {
916 for_each_possible_cpu(cpu)
917 free_page((unsigned long)per_cpu_ptr(uprobe_cpu_buffer,
918 cpu)->buf);
919
920 free_percpu(uprobe_cpu_buffer);
921 uprobe_cpu_buffer = NULL;
922 }
923 }
924
925 static struct uprobe_cpu_buffer *uprobe_buffer_get(void)
926 {
927 struct uprobe_cpu_buffer *ucb;
928 int cpu;
929
930 cpu = raw_smp_processor_id();
931 ucb = per_cpu_ptr(uprobe_cpu_buffer, cpu);
932
933 /*
934 * Use per-cpu buffers for fastest access, but we might migrate
935 * so the mutex makes sure we have sole access to it.
936 */
937 mutex_lock(&ucb->mutex);
938
939 return ucb;
940 }
941
942 static void uprobe_buffer_put(struct uprobe_cpu_buffer *ucb)
943 {
944 if (!ucb)
945 return;
946 mutex_unlock(&ucb->mutex);
947 }
948
949 static struct uprobe_cpu_buffer *prepare_uprobe_buffer(struct trace_uprobe *tu,
950 struct pt_regs *regs,
951 struct uprobe_cpu_buffer **ucbp)
952 {
953 struct uprobe_cpu_buffer *ucb;
954 int dsize, esize;
955
956 if (*ucbp)
957 return *ucbp;
958
959 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
960 dsize = __get_data_size(&tu->tp, regs, NULL);
961
962 ucb = uprobe_buffer_get();
963 ucb->dsize = tu->tp.size + dsize;
964
965 store_trace_args(ucb->buf, &tu->tp, regs, NULL, esize, dsize);
966
967 *ucbp = ucb;
968 return ucb;
969 }
970
971 static void __uprobe_trace_func(struct trace_uprobe *tu,
972 unsigned long func, struct pt_regs *regs,
973 struct uprobe_cpu_buffer *ucb,
974 struct trace_event_file *trace_file)
975 {
976 struct uprobe_trace_entry_head *entry;
977 struct trace_event_buffer fbuffer;
978 void *data;
979 int size, esize;
980 struct trace_event_call *call = trace_probe_event_call(&tu->tp);
981
982 WARN_ON(call != trace_file->event_call);
983
984 if (WARN_ON_ONCE(ucb->dsize > PAGE_SIZE))
985 return;
986
987 if (trace_trigger_soft_disabled(trace_file))
988 return;
989
990 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
991 size = esize + ucb->dsize;
992 entry = trace_event_buffer_reserve(&fbuffer, trace_file, size);
993 if (!entry)
994 return;
995
996 if (is_ret_probe(tu)) {
997 entry->vaddr[0] = func;
998 entry->vaddr[1] = instruction_pointer(regs);
999 data = DATAOF_TRACE_ENTRY(entry, true);
1000 } else {
1001 entry->vaddr[0] = instruction_pointer(regs);
1002 data = DATAOF_TRACE_ENTRY(entry, false);
1003 }
1004
1005 memcpy(data, ucb->buf, ucb->dsize);
1006
1007 trace_event_buffer_commit(&fbuffer);
1008 }
1009
1010 /* uprobe handler */
1011 static int uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs,
1012 struct uprobe_cpu_buffer **ucbp)
1013 {
1014 struct event_file_link *link;
1015 struct uprobe_cpu_buffer *ucb;
1016
1017 if (is_ret_probe(tu))
1018 return 0;
1019
1020 ucb = prepare_uprobe_buffer(tu, regs, ucbp);
1021
1022 rcu_read_lock();
1023 trace_probe_for_each_link_rcu(link, &tu->tp)
1024 __uprobe_trace_func(tu, 0, regs, ucb, link->file);
1025 rcu_read_unlock();
1026
1027 return 0;
1028 }
1029
1030 static void uretprobe_trace_func(struct trace_uprobe *tu, unsigned long func,
1031 struct pt_regs *regs,
1032 struct uprobe_cpu_buffer **ucbp)
1033 {
1034 struct event_file_link *link;
1035 struct uprobe_cpu_buffer *ucb;
1036
1037 ucb = prepare_uprobe_buffer(tu, regs, ucbp);
1038
1039 rcu_read_lock();
1040 trace_probe_for_each_link_rcu(link, &tu->tp)
1041 __uprobe_trace_func(tu, func, regs, ucb, link->file);
1042 rcu_read_unlock();
1043 }
1044
1045 /* Event entry printers */
1046 static enum print_line_t
1047 print_uprobe_event(struct trace_iterator *iter, int flags, struct trace_event *event)
1048 {
1049 struct uprobe_trace_entry_head *entry;
1050 struct trace_seq *s = &iter->seq;
1051 struct trace_uprobe *tu;
1052 u8 *data;
1053
1054 entry = (struct uprobe_trace_entry_head *)iter->ent;
1055 tu = trace_uprobe_primary_from_call(
1056 container_of(event, struct trace_event_call, event));
1057 if (unlikely(!tu))
1058 goto out;
1059
1060 if (is_ret_probe(tu)) {
1061 trace_seq_printf(s, "%s: (0x%lx <- 0x%lx)",
1062 trace_probe_name(&tu->tp),
1063 entry->vaddr[1], entry->vaddr[0]);
1064 data = DATAOF_TRACE_ENTRY(entry, true);
1065 } else {
1066 trace_seq_printf(s, "%s: (0x%lx)",
1067 trace_probe_name(&tu->tp),
1068 entry->vaddr[0]);
1069 data = DATAOF_TRACE_ENTRY(entry, false);
1070 }
1071
1072 if (trace_probe_print_args(s, tu->tp.args, tu->tp.nr_args, data, entry) < 0)
1073 goto out;
1074
1075 trace_seq_putc(s, '\n');
1076
1077 out:
1078 return trace_handle_return(s);
1079 }
1080
1081 typedef bool (*filter_func_t)(struct uprobe_consumer *self,
1082 enum uprobe_filter_ctx ctx,
1083 struct mm_struct *mm);
1084
1085 static int trace_uprobe_enable(struct trace_uprobe *tu, filter_func_t filter)
1086 {
1087 int ret;
1088
1089 tu->consumer.filter = filter;
1090 tu->inode = d_real_inode(tu->path.dentry);
1091
1092 if (tu->ref_ctr_offset)
1093 ret = uprobe_register_refctr(tu->inode, tu->offset,
1094 tu->ref_ctr_offset, &tu->consumer);
1095 else
1096 ret = uprobe_register(tu->inode, tu->offset, &tu->consumer);
1097
1098 if (ret)
1099 tu->inode = NULL;
1100
1101 return ret;
1102 }
1103
1104 static void __probe_event_disable(struct trace_probe *tp)
1105 {
1106 struct trace_uprobe *tu;
1107
1108 tu = container_of(tp, struct trace_uprobe, tp);
1109 WARN_ON(!uprobe_filter_is_empty(tu->tp.event->filter));
1110
1111 list_for_each_entry(tu, trace_probe_probe_list(tp), tp.list) {
1112 if (!tu->inode)
1113 continue;
1114
1115 uprobe_unregister(tu->inode, tu->offset, &tu->consumer);
1116 tu->inode = NULL;
1117 }
1118 }
1119
1120 static int probe_event_enable(struct trace_event_call *call,
1121 struct trace_event_file *file, filter_func_t filter)
1122 {
1123 struct trace_probe *tp;
1124 struct trace_uprobe *tu;
1125 bool enabled;
1126 int ret;
1127
1128 tp = trace_probe_primary_from_call(call);
1129 if (WARN_ON_ONCE(!tp))
1130 return -ENODEV;
1131 enabled = trace_probe_is_enabled(tp);
1132
1133 /* This may also change "enabled" state */
1134 if (file) {
1135 if (trace_probe_test_flag(tp, TP_FLAG_PROFILE))
1136 return -EINTR;
1137
1138 ret = trace_probe_add_file(tp, file);
1139 if (ret < 0)
1140 return ret;
1141 } else {
1142 if (trace_probe_test_flag(tp, TP_FLAG_TRACE))
1143 return -EINTR;
1144
1145 trace_probe_set_flag(tp, TP_FLAG_PROFILE);
1146 }
1147
1148 tu = container_of(tp, struct trace_uprobe, tp);
1149 WARN_ON(!uprobe_filter_is_empty(tu->tp.event->filter));
1150
1151 if (enabled)
1152 return 0;
1153
1154 ret = uprobe_buffer_enable();
1155 if (ret)
1156 goto err_flags;
1157
1158 list_for_each_entry(tu, trace_probe_probe_list(tp), tp.list) {
1159 ret = trace_uprobe_enable(tu, filter);
1160 if (ret) {
1161 __probe_event_disable(tp);
1162 goto err_buffer;
1163 }
1164 }
1165
1166 return 0;
1167
1168 err_buffer:
1169 uprobe_buffer_disable();
1170
1171 err_flags:
1172 if (file)
1173 trace_probe_remove_file(tp, file);
1174 else
1175 trace_probe_clear_flag(tp, TP_FLAG_PROFILE);
1176
1177 return ret;
1178 }
1179
1180 static void probe_event_disable(struct trace_event_call *call,
1181 struct trace_event_file *file)
1182 {
1183 struct trace_probe *tp;
1184
1185 tp = trace_probe_primary_from_call(call);
1186 if (WARN_ON_ONCE(!tp))
1187 return;
1188
1189 if (!trace_probe_is_enabled(tp))
1190 return;
1191
1192 if (file) {
1193 if (trace_probe_remove_file(tp, file) < 0)
1194 return;
1195
1196 if (trace_probe_is_enabled(tp))
1197 return;
1198 } else
1199 trace_probe_clear_flag(tp, TP_FLAG_PROFILE);
1200
1201 __probe_event_disable(tp);
1202 uprobe_buffer_disable();
1203 }
1204
1205 static int uprobe_event_define_fields(struct trace_event_call *event_call)
1206 {
1207 int ret, size;
1208 struct uprobe_trace_entry_head field;
1209 struct trace_uprobe *tu;
1210
1211 tu = trace_uprobe_primary_from_call(event_call);
1212 if (unlikely(!tu))
1213 return -ENODEV;
1214
1215 if (is_ret_probe(tu)) {
1216 DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_FUNC, 0);
1217 DEFINE_FIELD(unsigned long, vaddr[1], FIELD_STRING_RETIP, 0);
1218 size = SIZEOF_TRACE_ENTRY(true);
1219 } else {
1220 DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_IP, 0);
1221 size = SIZEOF_TRACE_ENTRY(false);
1222 }
1223
1224 return traceprobe_define_arg_fields(event_call, size, &tu->tp);
1225 }
1226
1227 #ifdef CONFIG_PERF_EVENTS
1228 static bool
1229 __uprobe_perf_filter(struct trace_uprobe_filter *filter, struct mm_struct *mm)
1230 {
1231 struct perf_event *event;
1232
1233 list_for_each_entry(event, &filter->perf_events, hw.tp_list) {
1234 if (event->hw.target->mm == mm)
1235 return true;
1236 }
1237
1238 return false;
1239 }
1240
1241 static inline bool
1242 trace_uprobe_filter_event(struct trace_uprobe_filter *filter,
1243 struct perf_event *event)
1244 {
1245 return __uprobe_perf_filter(filter, event->hw.target->mm);
1246 }
1247
1248 static bool trace_uprobe_filter_remove(struct trace_uprobe_filter *filter,
1249 struct perf_event *event)
1250 {
1251 bool done;
1252
1253 write_lock(&filter->rwlock);
1254 if (event->hw.target) {
1255 list_del(&event->hw.tp_list);
1256 done = filter->nr_systemwide ||
1257 (event->hw.target->flags & PF_EXITING) ||
1258 trace_uprobe_filter_event(filter, event);
1259 } else {
1260 filter->nr_systemwide--;
1261 done = filter->nr_systemwide;
1262 }
1263 write_unlock(&filter->rwlock);
1264
1265 return done;
1266 }
1267
1268 /* This returns true if the filter always covers target mm */
1269 static bool trace_uprobe_filter_add(struct trace_uprobe_filter *filter,
1270 struct perf_event *event)
1271 {
1272 bool done;
1273
1274 write_lock(&filter->rwlock);
1275 if (event->hw.target) {
1276 /*
1277 * event->parent != NULL means copy_process(), we can avoid
1278 * uprobe_apply(). current->mm must be probed and we can rely
1279 * on dup_mmap() which preserves the already installed bp's.
1280 *
1281 * attr.enable_on_exec means that exec/mmap will install the
1282 * breakpoints we need.
1283 */
1284 done = filter->nr_systemwide ||
1285 event->parent || event->attr.enable_on_exec ||
1286 trace_uprobe_filter_event(filter, event);
1287 list_add(&event->hw.tp_list, &filter->perf_events);
1288 } else {
1289 done = filter->nr_systemwide;
1290 filter->nr_systemwide++;
1291 }
1292 write_unlock(&filter->rwlock);
1293
1294 return done;
1295 }
1296
1297 static int uprobe_perf_close(struct trace_event_call *call,
1298 struct perf_event *event)
1299 {
1300 struct trace_probe *tp;
1301 struct trace_uprobe *tu;
1302 int ret = 0;
1303
1304 tp = trace_probe_primary_from_call(call);
1305 if (WARN_ON_ONCE(!tp))
1306 return -ENODEV;
1307
1308 tu = container_of(tp, struct trace_uprobe, tp);
1309 if (trace_uprobe_filter_remove(tu->tp.event->filter, event))
1310 return 0;
1311
1312 list_for_each_entry(tu, trace_probe_probe_list(tp), tp.list) {
1313 ret = uprobe_apply(tu->inode, tu->offset, &tu->consumer, false);
1314 if (ret)
1315 break;
1316 }
1317
1318 return ret;
1319 }
1320
1321 static int uprobe_perf_open(struct trace_event_call *call,
1322 struct perf_event *event)
1323 {
1324 struct trace_probe *tp;
1325 struct trace_uprobe *tu;
1326 int err = 0;
1327
1328 tp = trace_probe_primary_from_call(call);
1329 if (WARN_ON_ONCE(!tp))
1330 return -ENODEV;
1331
1332 tu = container_of(tp, struct trace_uprobe, tp);
1333 if (trace_uprobe_filter_add(tu->tp.event->filter, event))
1334 return 0;
1335
1336 list_for_each_entry(tu, trace_probe_probe_list(tp), tp.list) {
1337 err = uprobe_apply(tu->inode, tu->offset, &tu->consumer, true);
1338 if (err) {
1339 uprobe_perf_close(call, event);
1340 break;
1341 }
1342 }
1343
1344 return err;
1345 }
1346
1347 static bool uprobe_perf_filter(struct uprobe_consumer *uc,
1348 enum uprobe_filter_ctx ctx, struct mm_struct *mm)
1349 {
1350 struct trace_uprobe_filter *filter;
1351 struct trace_uprobe *tu;
1352 int ret;
1353
1354 tu = container_of(uc, struct trace_uprobe, consumer);
1355 filter = tu->tp.event->filter;
1356
1357 /*
1358 * speculative short-circuiting check to avoid unnecessarily taking
1359 * filter->rwlock below, if the uprobe has system-wide consumer
1360 */
1361 if (READ_ONCE(filter->nr_systemwide))
1362 return true;
1363
1364 read_lock(&filter->rwlock);
1365 ret = __uprobe_perf_filter(filter, mm);
1366 read_unlock(&filter->rwlock);
1367
1368 return ret;
1369 }
1370
1371 static void __uprobe_perf_func(struct trace_uprobe *tu,
1372 unsigned long func, struct pt_regs *regs,
1373 struct uprobe_cpu_buffer **ucbp)
1374 {
1375 struct trace_event_call *call = trace_probe_event_call(&tu->tp);
1376 struct uprobe_trace_entry_head *entry;
1377 struct uprobe_cpu_buffer *ucb;
1378 struct hlist_head *head;
1379 void *data;
1380 int size, esize;
1381 int rctx;
1382
1383 #ifdef CONFIG_BPF_EVENTS
1384 if (bpf_prog_array_valid(call)) {
1385 u32 ret;
1386
1387 ret = bpf_prog_run_array_uprobe(call->prog_array, regs, bpf_prog_run);
1388 if (!ret)
1389 return;
1390 }
1391 #endif /* CONFIG_BPF_EVENTS */
1392
1393 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
1394
1395 ucb = prepare_uprobe_buffer(tu, regs, ucbp);
1396 size = esize + ucb->dsize;
1397 size = ALIGN(size + sizeof(u32), sizeof(u64)) - sizeof(u32);
1398 if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, "profile buffer not large enough"))
1399 return;
1400
1401 preempt_disable();
1402 head = this_cpu_ptr(call->perf_events);
1403 if (hlist_empty(head))
1404 goto out;
1405
1406 entry = perf_trace_buf_alloc(size, NULL, &rctx);
1407 if (!entry)
1408 goto out;
1409
1410 if (is_ret_probe(tu)) {
1411 entry->vaddr[0] = func;
1412 entry->vaddr[1] = instruction_pointer(regs);
1413 data = DATAOF_TRACE_ENTRY(entry, true);
1414 } else {
1415 entry->vaddr[0] = instruction_pointer(regs);
1416 data = DATAOF_TRACE_ENTRY(entry, false);
1417 }
1418
1419 memcpy(data, ucb->buf, ucb->dsize);
1420
1421 if (size - esize > ucb->dsize)
1422 memset(data + ucb->dsize, 0, size - esize - ucb->dsize);
1423
1424 perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs,
1425 head, NULL);
1426 out:
1427 preempt_enable();
1428 }
1429
1430 /* uprobe profile handler */
1431 static int uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs,
1432 struct uprobe_cpu_buffer **ucbp)
1433 {
1434 if (!uprobe_perf_filter(&tu->consumer, 0, current->mm))
1435 return UPROBE_HANDLER_REMOVE;
1436
1437 if (!is_ret_probe(tu))
1438 __uprobe_perf_func(tu, 0, regs, ucbp);
1439 return 0;
1440 }
1441
1442 static void uretprobe_perf_func(struct trace_uprobe *tu, unsigned long func,
1443 struct pt_regs *regs,
1444 struct uprobe_cpu_buffer **ucbp)
1445 {
1446 __uprobe_perf_func(tu, func, regs, ucbp);
1447 }
1448
1449 int bpf_get_uprobe_info(const struct perf_event *event, u32 *fd_type,
1450 const char **filename, u64 *probe_offset,
1451 u64 *probe_addr, bool perf_type_tracepoint)
1452 {
1453 const char *pevent = trace_event_name(event->tp_event);
1454 const char *group = event->tp_event->class->system;
1455 struct trace_uprobe *tu;
1456
1457 if (perf_type_tracepoint)
1458 tu = find_probe_event(pevent, group);
1459 else
1460 tu = trace_uprobe_primary_from_call(event->tp_event);
1461 if (!tu)
1462 return -EINVAL;
1463
1464 *fd_type = is_ret_probe(tu) ? BPF_FD_TYPE_URETPROBE
1465 : BPF_FD_TYPE_UPROBE;
1466 *filename = tu->filename;
1467 *probe_offset = tu->offset;
1468 *probe_addr = 0;
1469 return 0;
1470 }
1471 #endif /* CONFIG_PERF_EVENTS */
1472
1473 static int
1474 trace_uprobe_register(struct trace_event_call *event, enum trace_reg type,
1475 void *data)
1476 {
1477 struct trace_event_file *file = data;
1478
1479 switch (type) {
1480 case TRACE_REG_REGISTER:
1481 return probe_event_enable(event, file, NULL);
1482
1483 case TRACE_REG_UNREGISTER:
1484 probe_event_disable(event, file);
1485 return 0;
1486
1487 #ifdef CONFIG_PERF_EVENTS
1488 case TRACE_REG_PERF_REGISTER:
1489 return probe_event_enable(event, NULL, uprobe_perf_filter);
1490
1491 case TRACE_REG_PERF_UNREGISTER:
1492 probe_event_disable(event, NULL);
1493 return 0;
1494
1495 case TRACE_REG_PERF_OPEN:
1496 return uprobe_perf_open(event, data);
1497
1498 case TRACE_REG_PERF_CLOSE:
1499 return uprobe_perf_close(event, data);
1500
1501 #endif
1502 default:
1503 return 0;
1504 }
1505 }
1506
1507 static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs)
1508 {
1509 struct trace_uprobe *tu;
1510 struct uprobe_dispatch_data udd;
1511 struct uprobe_cpu_buffer *ucb = NULL;
1512 int ret = 0;
1513
1514 tu = container_of(con, struct trace_uprobe, consumer);
1515 tu->nhit++;
1516
1517 udd.tu = tu;
1518 udd.bp_addr = instruction_pointer(regs);
1519
1520 current->utask->vaddr = (unsigned long) &udd;
1521
1522 if (WARN_ON_ONCE(!uprobe_cpu_buffer))
1523 return 0;
1524
1525 if (trace_probe_test_flag(&tu->tp, TP_FLAG_TRACE))
1526 ret |= uprobe_trace_func(tu, regs, &ucb);
1527
1528 #ifdef CONFIG_PERF_EVENTS
1529 if (trace_probe_test_flag(&tu->tp, TP_FLAG_PROFILE))
1530 ret |= uprobe_perf_func(tu, regs, &ucb);
1531 #endif
1532 uprobe_buffer_put(ucb);
1533 return ret;
1534 }
1535
1536 static int uretprobe_dispatcher(struct uprobe_consumer *con,
1537 unsigned long func, struct pt_regs *regs)
1538 {
1539 struct trace_uprobe *tu;
1540 struct uprobe_dispatch_data udd;
1541 struct uprobe_cpu_buffer *ucb = NULL;
1542
1543 tu = container_of(con, struct trace_uprobe, consumer);
1544
1545 udd.tu = tu;
1546 udd.bp_addr = func;
1547
1548 current->utask->vaddr = (unsigned long) &udd;
1549
1550 if (WARN_ON_ONCE(!uprobe_cpu_buffer))
1551 return 0;
1552
1553 if (trace_probe_test_flag(&tu->tp, TP_FLAG_TRACE))
1554 uretprobe_trace_func(tu, func, regs, &ucb);
1555
1556 #ifdef CONFIG_PERF_EVENTS
1557 if (trace_probe_test_flag(&tu->tp, TP_FLAG_PROFILE))
1558 uretprobe_perf_func(tu, func, regs, &ucb);
1559 #endif
1560 uprobe_buffer_put(ucb);
1561 return 0;
1562 }
1563
1564 static struct trace_event_functions uprobe_funcs = {
1565 .trace = print_uprobe_event
1566 };
1567
1568 static struct trace_event_fields uprobe_fields_array[] = {
1569 { .type = TRACE_FUNCTION_TYPE,
1570 .define_fields = uprobe_event_define_fields },
1571 {}
1572 };
1573
1574 static inline void init_trace_event_call(struct trace_uprobe *tu)
1575 {
1576 struct trace_event_call *call = trace_probe_event_call(&tu->tp);
1577 call->event.funcs = &uprobe_funcs;
1578 call->class->fields_array = uprobe_fields_array;
1579
1580 call->flags = TRACE_EVENT_FL_UPROBE | TRACE_EVENT_FL_CAP_ANY;
1581 call->class->reg = trace_uprobe_register;
1582 }
1583
1584 static int register_uprobe_event(struct trace_uprobe *tu)
1585 {
1586 init_trace_event_call(tu);
1587
1588 return trace_probe_register_event_call(&tu->tp);
1589 }
1590
1591 static int unregister_uprobe_event(struct trace_uprobe *tu)
1592 {
1593 return trace_probe_unregister_event_call(&tu->tp);
1594 }
1595
1596 #ifdef CONFIG_PERF_EVENTS
1597 struct trace_event_call *
1598 create_local_trace_uprobe(char *name, unsigned long offs,
1599 unsigned long ref_ctr_offset, bool is_return)
1600 {
1601 enum probe_print_type ptype;
1602 struct trace_uprobe *tu;
1603 struct path path;
1604 int ret;
1605
1606 ret = kern_path(name, LOOKUP_FOLLOW, &path);
1607 if (ret)
1608 return ERR_PTR(ret);
1609
1610 if (!d_is_reg(path.dentry)) {
1611 path_put(&path);
1612 return ERR_PTR(-EINVAL);
1613 }
1614
1615 /*
1616 * local trace_kprobes are not added to dyn_event, so they are never
1617 * searched in find_trace_kprobe(). Therefore, there is no concern of
1618 * duplicated name "DUMMY_EVENT" here.
1619 */
1620 tu = alloc_trace_uprobe(UPROBE_EVENT_SYSTEM, "DUMMY_EVENT", 0,
1621 is_return);
1622
1623 if (IS_ERR(tu)) {
1624 pr_info("Failed to allocate trace_uprobe.(%d)\n",
1625 (int)PTR_ERR(tu));
1626 path_put(&path);
1627 return ERR_CAST(tu);
1628 }
1629
1630 tu->offset = offs;
1631 tu->path = path;
1632 tu->ref_ctr_offset = ref_ctr_offset;
1633 tu->filename = kstrdup(name, GFP_KERNEL);
1634 if (!tu->filename) {
1635 ret = -ENOMEM;
1636 goto error;
1637 }
1638
1639 init_trace_event_call(tu);
1640
1641 ptype = is_ret_probe(tu) ? PROBE_PRINT_RETURN : PROBE_PRINT_NORMAL;
1642 if (traceprobe_set_print_fmt(&tu->tp, ptype) < 0) {
1643 ret = -ENOMEM;
1644 goto error;
1645 }
1646
1647 return trace_probe_event_call(&tu->tp);
1648 error:
1649 free_trace_uprobe(tu);
1650 return ERR_PTR(ret);
1651 }
1652
1653 void destroy_local_trace_uprobe(struct trace_event_call *event_call)
1654 {
1655 struct trace_uprobe *tu;
1656
1657 tu = trace_uprobe_primary_from_call(event_call);
1658
1659 free_trace_uprobe(tu);
1660 }
1661 #endif /* CONFIG_PERF_EVENTS */
1662
1663 /* Make a trace interface for controlling probe points */
1664 static __init int init_uprobe_trace(void)
1665 {
1666 int ret;
1667
1668 ret = dyn_event_register(&trace_uprobe_ops);
1669 if (ret)
1670 return ret;
1671
1672 ret = tracing_init_dentry();
1673 if (ret)
1674 return 0;
1675
1676 trace_create_file("uprobe_events", TRACE_MODE_WRITE, NULL,
1677 NULL, &uprobe_events_ops);
1678 /* Profile interface */
1679 trace_create_file("uprobe_profile", TRACE_MODE_READ, NULL,
1680 NULL, &uprobe_profile_ops);
1681 return 0;
1682 }
1683
1684 fs_initcall(init_uprobe_trace);
1685
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