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accel/amdxdna: use modern PM helpers
[drm/drm-misc.git] / kernel / trace / trace_uprobe.c
blobfed382b7881b82ee3c334ea77860cce77581a74d
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 #include <linux/percpu.h>
21
22 #include "trace_dynevent.h"
23 #include "trace_probe.h"
24 #include "trace_probe_tmpl.h"
25
26 #define UPROBE_EVENT_SYSTEM "uprobes"
27
28 struct uprobe_trace_entry_head {
29 struct trace_entry ent;
30 unsigned long vaddr[];
31 };
32
33 #define SIZEOF_TRACE_ENTRY(is_return) \
34 (sizeof(struct uprobe_trace_entry_head) + \
35 sizeof(unsigned long) * (is_return ? 2 : 1))
36
37 #define DATAOF_TRACE_ENTRY(entry, is_return) \
38 ((void*)(entry) + SIZEOF_TRACE_ENTRY(is_return))
39
40 static int trace_uprobe_create(const char *raw_command);
41 static int trace_uprobe_show(struct seq_file *m, struct dyn_event *ev);
42 static int trace_uprobe_release(struct dyn_event *ev);
43 static bool trace_uprobe_is_busy(struct dyn_event *ev);
44 static bool trace_uprobe_match(const char *system, const char *event,
45 int argc, const char **argv, struct dyn_event *ev);
46
47 static struct dyn_event_operations trace_uprobe_ops = {
48 .create = trace_uprobe_create,
49 .show = trace_uprobe_show,
50 .is_busy = trace_uprobe_is_busy,
51 .free = trace_uprobe_release,
52 .match = trace_uprobe_match,
53 };
54
55 /*
56 * uprobe event core functions
57 */
58 struct trace_uprobe {
59 struct dyn_event devent;
60 struct uprobe_consumer consumer;
61 struct path path;
62 char *filename;
63 struct uprobe *uprobe;
64 unsigned long offset;
65 unsigned long ref_ctr_offset;
66 unsigned long __percpu *nhits;
67 struct trace_probe tp;
68 };
69
70 static bool is_trace_uprobe(struct dyn_event *ev)
71 {
72 return ev->ops == &trace_uprobe_ops;
73 }
74
75 static struct trace_uprobe *to_trace_uprobe(struct dyn_event *ev)
76 {
77 return container_of(ev, struct trace_uprobe, devent);
78 }
79
80 /**
81 * for_each_trace_uprobe - iterate over the trace_uprobe list
82 * @pos: the struct trace_uprobe * for each entry
83 * @dpos: the struct dyn_event * to use as a loop cursor
84 */
85 #define for_each_trace_uprobe(pos, dpos) \
86 for_each_dyn_event(dpos) \
87 if (is_trace_uprobe(dpos) && (pos = to_trace_uprobe(dpos)))
88
89 static int register_uprobe_event(struct trace_uprobe *tu);
90 static int unregister_uprobe_event(struct trace_uprobe *tu);
91
92 static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs,
93 __u64 *data);
94 static int uretprobe_dispatcher(struct uprobe_consumer *con,
95 unsigned long func, struct pt_regs *regs,
96 __u64 *data);
97
98 #ifdef CONFIG_STACK_GROWSUP
99 static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n)
100 {
101 return addr - (n * sizeof(long));
102 }
103 #else
104 static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n)
105 {
106 return addr + (n * sizeof(long));
107 }
108 #endif
109
110 static unsigned long get_user_stack_nth(struct pt_regs *regs, unsigned int n)
111 {
112 unsigned long ret;
113 unsigned long addr = user_stack_pointer(regs);
114
115 addr = adjust_stack_addr(addr, n);
116
117 if (copy_from_user(&ret, (void __force __user *) addr, sizeof(ret)))
118 return 0;
119
120 return ret;
121 }
122
123 /*
124 * Uprobes-specific fetch functions
125 */
126 static nokprobe_inline int
127 probe_mem_read(void *dest, void *src, size_t size)
128 {
129 void __user *vaddr = (void __force __user *)src;
130
131 return copy_from_user(dest, vaddr, size) ? -EFAULT : 0;
132 }
133
134 static nokprobe_inline int
135 probe_mem_read_user(void *dest, void *src, size_t size)
136 {
137 return probe_mem_read(dest, src, size);
138 }
139
140 /*
141 * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max
142 * length and relative data location.
143 */
144 static nokprobe_inline int
145 fetch_store_string(unsigned long addr, void *dest, void *base)
146 {
147 long ret;
148 u32 loc = *(u32 *)dest;
149 int maxlen = get_loc_len(loc);
150 u8 *dst = get_loc_data(dest, base);
151 void __user *src = (void __force __user *) addr;
152
153 if (unlikely(!maxlen))
154 return -ENOMEM;
155
156 if (addr == FETCH_TOKEN_COMM)
157 ret = strscpy(dst, current->comm, maxlen);
158 else
159 ret = strncpy_from_user(dst, src, maxlen);
160 if (ret >= 0) {
161 if (ret == maxlen)
162 dst[ret - 1] = '\0';
163 else
164 /*
165 * Include the terminating null byte. In this case it
166 * was copied by strncpy_from_user but not accounted
167 * for in ret.
168 */
169 ret++;
170 *(u32 *)dest = make_data_loc(ret, (void *)dst - base);
171 } else
172 *(u32 *)dest = make_data_loc(0, (void *)dst - base);
173
174 return ret;
175 }
176
177 static nokprobe_inline int
178 fetch_store_string_user(unsigned long addr, void *dest, void *base)
179 {
180 return fetch_store_string(addr, dest, base);
181 }
182
183 /* Return the length of string -- including null terminal byte */
184 static nokprobe_inline int
185 fetch_store_strlen(unsigned long addr)
186 {
187 int len;
188 void __user *vaddr = (void __force __user *) addr;
189
190 if (addr == FETCH_TOKEN_COMM)
191 len = strlen(current->comm) + 1;
192 else
193 len = strnlen_user(vaddr, MAX_STRING_SIZE);
194
195 return (len > MAX_STRING_SIZE) ? 0 : len;
196 }
197
198 static nokprobe_inline int
199 fetch_store_strlen_user(unsigned long addr)
200 {
201 return fetch_store_strlen(addr);
202 }
203
204 static unsigned long translate_user_vaddr(unsigned long file_offset)
205 {
206 unsigned long base_addr;
207 struct uprobe_dispatch_data *udd;
208
209 udd = (void *) current->utask->vaddr;
210
211 base_addr = udd->bp_addr - udd->tu->offset;
212 return base_addr + file_offset;
213 }
214
215 /* Note that we don't verify it, since the code does not come from user space */
216 static int
217 process_fetch_insn(struct fetch_insn *code, void *rec, void *edata,
218 void *dest, void *base)
219 {
220 struct pt_regs *regs = rec;
221 unsigned long val;
222 int ret;
223
224 /* 1st stage: get value from context */
225 switch (code->op) {
226 case FETCH_OP_REG:
227 val = regs_get_register(regs, code->param);
228 break;
229 case FETCH_OP_STACK:
230 val = get_user_stack_nth(regs, code->param);
231 break;
232 case FETCH_OP_STACKP:
233 val = user_stack_pointer(regs);
234 break;
235 case FETCH_OP_RETVAL:
236 val = regs_return_value(regs);
237 break;
238 case FETCH_OP_COMM:
239 val = FETCH_TOKEN_COMM;
240 break;
241 case FETCH_OP_FOFFS:
242 val = translate_user_vaddr(code->immediate);
243 break;
244 default:
245 ret = process_common_fetch_insn(code, &val);
246 if (ret < 0)
247 return ret;
248 }
249 code++;
250
251 return process_fetch_insn_bottom(code, val, dest, base);
252 }
253 NOKPROBE_SYMBOL(process_fetch_insn)
254
255 static inline void init_trace_uprobe_filter(struct trace_uprobe_filter *filter)
256 {
257 rwlock_init(&filter->rwlock);
258 filter->nr_systemwide = 0;
259 INIT_LIST_HEAD(&filter->perf_events);
260 }
261
262 static inline bool uprobe_filter_is_empty(struct trace_uprobe_filter *filter)
263 {
264 return !filter->nr_systemwide && list_empty(&filter->perf_events);
265 }
266
267 static inline bool is_ret_probe(struct trace_uprobe *tu)
268 {
269 return tu->consumer.ret_handler != NULL;
270 }
271
272 static bool trace_uprobe_is_busy(struct dyn_event *ev)
273 {
274 struct trace_uprobe *tu = to_trace_uprobe(ev);
275
276 return trace_probe_is_enabled(&tu->tp);
277 }
278
279 static bool trace_uprobe_match_command_head(struct trace_uprobe *tu,
280 int argc, const char **argv)
281 {
282 char buf[MAX_ARGSTR_LEN + 1];
283 int len;
284
285 if (!argc)
286 return true;
287
288 len = strlen(tu->filename);
289 if (strncmp(tu->filename, argv[0], len) || argv[0][len] != ':')
290 return false;
291
292 if (tu->ref_ctr_offset == 0)
293 snprintf(buf, sizeof(buf), "0x%0*lx",
294 (int)(sizeof(void *) * 2), tu->offset);
295 else
296 snprintf(buf, sizeof(buf), "0x%0*lx(0x%lx)",
297 (int)(sizeof(void *) * 2), tu->offset,
298 tu->ref_ctr_offset);
299 if (strcmp(buf, &argv[0][len + 1]))
300 return false;
301
302 argc--; argv++;
303
304 return trace_probe_match_command_args(&tu->tp, argc, argv);
305 }
306
307 static bool trace_uprobe_match(const char *system, const char *event,
308 int argc, const char **argv, struct dyn_event *ev)
309 {
310 struct trace_uprobe *tu = to_trace_uprobe(ev);
311
312 return (event[0] == '\0' ||
313 strcmp(trace_probe_name(&tu->tp), event) == 0) &&
314 (!system || strcmp(trace_probe_group_name(&tu->tp), system) == 0) &&
315 trace_uprobe_match_command_head(tu, argc, argv);
316 }
317
318 static nokprobe_inline struct trace_uprobe *
319 trace_uprobe_primary_from_call(struct trace_event_call *call)
320 {
321 struct trace_probe *tp;
322
323 tp = trace_probe_primary_from_call(call);
324 if (WARN_ON_ONCE(!tp))
325 return NULL;
326
327 return container_of(tp, struct trace_uprobe, tp);
328 }
329
330 /*
331 * Allocate new trace_uprobe and initialize it (including uprobes).
332 */
333 static struct trace_uprobe *
334 alloc_trace_uprobe(const char *group, const char *event, int nargs, bool is_ret)
335 {
336 struct trace_uprobe *tu;
337 int ret;
338
339 tu = kzalloc(struct_size(tu, tp.args, nargs), GFP_KERNEL);
340 if (!tu)
341 return ERR_PTR(-ENOMEM);
342
343 tu->nhits = alloc_percpu(unsigned long);
344 if (!tu->nhits) {
345 ret = -ENOMEM;
346 goto error;
347 }
348
349 ret = trace_probe_init(&tu->tp, event, group, true, nargs);
350 if (ret < 0)
351 goto error;
352
353 dyn_event_init(&tu->devent, &trace_uprobe_ops);
354 tu->consumer.handler = uprobe_dispatcher;
355 if (is_ret)
356 tu->consumer.ret_handler = uretprobe_dispatcher;
357 init_trace_uprobe_filter(tu->tp.event->filter);
358 return tu;
359
360 error:
361 free_percpu(tu->nhits);
362 kfree(tu);
363
364 return ERR_PTR(ret);
365 }
366
367 static void free_trace_uprobe(struct trace_uprobe *tu)
368 {
369 if (!tu)
370 return;
371
372 path_put(&tu->path);
373 trace_probe_cleanup(&tu->tp);
374 kfree(tu->filename);
375 free_percpu(tu->nhits);
376 kfree(tu);
377 }
378
379 static struct trace_uprobe *find_probe_event(const char *event, const char *group)
380 {
381 struct dyn_event *pos;
382 struct trace_uprobe *tu;
383
384 for_each_trace_uprobe(tu, pos)
385 if (strcmp(trace_probe_name(&tu->tp), event) == 0 &&
386 strcmp(trace_probe_group_name(&tu->tp), group) == 0)
387 return tu;
388
389 return NULL;
390 }
391
392 /* Unregister a trace_uprobe and probe_event */
393 static int unregister_trace_uprobe(struct trace_uprobe *tu)
394 {
395 int ret;
396
397 if (trace_probe_has_sibling(&tu->tp))
398 goto unreg;
399
400 /* If there's a reference to the dynamic event */
401 if (trace_event_dyn_busy(trace_probe_event_call(&tu->tp)))
402 return -EBUSY;
403
404 ret = unregister_uprobe_event(tu);
405 if (ret)
406 return ret;
407
408 unreg:
409 dyn_event_remove(&tu->devent);
410 trace_probe_unlink(&tu->tp);
411 free_trace_uprobe(tu);
412 return 0;
413 }
414
415 static bool trace_uprobe_has_same_uprobe(struct trace_uprobe *orig,
416 struct trace_uprobe *comp)
417 {
418 struct trace_probe_event *tpe = orig->tp.event;
419 struct inode *comp_inode = d_real_inode(comp->path.dentry);
420 int i;
421
422 list_for_each_entry(orig, &tpe->probes, tp.list) {
423 if (comp_inode != d_real_inode(orig->path.dentry) ||
424 comp->offset != orig->offset)
425 continue;
426
427 /*
428 * trace_probe_compare_arg_type() ensured that nr_args and
429 * each argument name and type are same. Let's compare comm.
430 */
431 for (i = 0; i < orig->tp.nr_args; i++) {
432 if (strcmp(orig->tp.args[i].comm,
433 comp->tp.args[i].comm))
434 break;
435 }
436
437 if (i == orig->tp.nr_args)
438 return true;
439 }
440
441 return false;
442 }
443
444 static int append_trace_uprobe(struct trace_uprobe *tu, struct trace_uprobe *to)
445 {
446 int ret;
447
448 ret = trace_probe_compare_arg_type(&tu->tp, &to->tp);
449 if (ret) {
450 /* Note that argument starts index = 2 */
451 trace_probe_log_set_index(ret + 1);
452 trace_probe_log_err(0, DIFF_ARG_TYPE);
453 return -EEXIST;
454 }
455 if (trace_uprobe_has_same_uprobe(to, tu)) {
456 trace_probe_log_set_index(0);
457 trace_probe_log_err(0, SAME_PROBE);
458 return -EEXIST;
459 }
460
461 /* Append to existing event */
462 ret = trace_probe_append(&tu->tp, &to->tp);
463 if (!ret)
464 dyn_event_add(&tu->devent, trace_probe_event_call(&tu->tp));
465
466 return ret;
467 }
468
469 /*
470 * Uprobe with multiple reference counter is not allowed. i.e.
471 * If inode and offset matches, reference counter offset *must*
472 * match as well. Though, there is one exception: If user is
473 * replacing old trace_uprobe with new one(same group/event),
474 * then we allow same uprobe with new reference counter as far
475 * as the new one does not conflict with any other existing
476 * ones.
477 */
478 static int validate_ref_ctr_offset(struct trace_uprobe *new)
479 {
480 struct dyn_event *pos;
481 struct trace_uprobe *tmp;
482 struct inode *new_inode = d_real_inode(new->path.dentry);
483
484 for_each_trace_uprobe(tmp, pos) {
485 if (new_inode == d_real_inode(tmp->path.dentry) &&
486 new->offset == tmp->offset &&
487 new->ref_ctr_offset != tmp->ref_ctr_offset) {
488 pr_warn("Reference counter offset mismatch.");
489 return -EINVAL;
490 }
491 }
492 return 0;
493 }
494
495 /* Register a trace_uprobe and probe_event */
496 static int register_trace_uprobe(struct trace_uprobe *tu)
497 {
498 struct trace_uprobe *old_tu;
499 int ret;
500
501 mutex_lock(&event_mutex);
502
503 ret = validate_ref_ctr_offset(tu);
504 if (ret)
505 goto end;
506
507 /* register as an event */
508 old_tu = find_probe_event(trace_probe_name(&tu->tp),
509 trace_probe_group_name(&tu->tp));
510 if (old_tu) {
511 if (is_ret_probe(tu) != is_ret_probe(old_tu)) {
512 trace_probe_log_set_index(0);
513 trace_probe_log_err(0, DIFF_PROBE_TYPE);
514 ret = -EEXIST;
515 } else {
516 ret = append_trace_uprobe(tu, old_tu);
517 }
518 goto end;
519 }
520
521 ret = register_uprobe_event(tu);
522 if (ret) {
523 if (ret == -EEXIST) {
524 trace_probe_log_set_index(0);
525 trace_probe_log_err(0, EVENT_EXIST);
526 } else
527 pr_warn("Failed to register probe event(%d)\n", ret);
528 goto end;
529 }
530
531 dyn_event_add(&tu->devent, trace_probe_event_call(&tu->tp));
532
533 end:
534 mutex_unlock(&event_mutex);
535
536 return ret;
537 }
538
539 /*
540 * Argument syntax:
541 * - Add uprobe: p|r[:[GRP/][EVENT]] PATH:OFFSET[%return][(REF)] [FETCHARGS]
542 */
543 static int __trace_uprobe_create(int argc, const char **argv)
544 {
545 struct trace_uprobe *tu;
546 const char *event = NULL, *group = UPROBE_EVENT_SYSTEM;
547 char *arg, *filename, *rctr, *rctr_end, *tmp;
548 char buf[MAX_EVENT_NAME_LEN];
549 char gbuf[MAX_EVENT_NAME_LEN];
550 enum probe_print_type ptype;
551 struct path path;
552 unsigned long offset, ref_ctr_offset;
553 bool is_return = false;
554 int i, ret;
555
556 ref_ctr_offset = 0;
557
558 switch (argv[0][0]) {
559 case 'r':
560 is_return = true;
561 break;
562 case 'p':
563 break;
564 default:
565 return -ECANCELED;
566 }
567
568 if (argc < 2)
569 return -ECANCELED;
570 if (argc - 2 > MAX_TRACE_ARGS)
571 return -E2BIG;
572
573 if (argv[0][1] == ':')
574 event = &argv[0][2];
575
576 if (!strchr(argv[1], '/'))
577 return -ECANCELED;
578
579 filename = kstrdup(argv[1], GFP_KERNEL);
580 if (!filename)
581 return -ENOMEM;
582
583 /* Find the last occurrence, in case the path contains ':' too. */
584 arg = strrchr(filename, ':');
585 if (!arg || !isdigit(arg[1])) {
586 kfree(filename);
587 return -ECANCELED;
588 }
589
590 trace_probe_log_init("trace_uprobe", argc, argv);
591 trace_probe_log_set_index(1); /* filename is the 2nd argument */
592
593 *arg++ = '\0';
594 ret = kern_path(filename, LOOKUP_FOLLOW, &path);
595 if (ret) {
596 trace_probe_log_err(0, FILE_NOT_FOUND);
597 kfree(filename);
598 trace_probe_log_clear();
599 return ret;
600 }
601 if (!d_is_reg(path.dentry)) {
602 trace_probe_log_err(0, NO_REGULAR_FILE);
603 ret = -EINVAL;
604 goto fail_address_parse;
605 }
606
607 /* Parse reference counter offset if specified. */
608 rctr = strchr(arg, '(');
609 if (rctr) {
610 rctr_end = strchr(rctr, ')');
611 if (!rctr_end) {
612 ret = -EINVAL;
613 rctr_end = rctr + strlen(rctr);
614 trace_probe_log_err(rctr_end - filename,
615 REFCNT_OPEN_BRACE);
616 goto fail_address_parse;
617 } else if (rctr_end[1] != '\0') {
618 ret = -EINVAL;
619 trace_probe_log_err(rctr_end + 1 - filename,
620 BAD_REFCNT_SUFFIX);
621 goto fail_address_parse;
622 }
623
624 *rctr++ = '\0';
625 *rctr_end = '\0';
626 ret = kstrtoul(rctr, 0, &ref_ctr_offset);
627 if (ret) {
628 trace_probe_log_err(rctr - filename, BAD_REFCNT);
629 goto fail_address_parse;
630 }
631 }
632
633 /* Check if there is %return suffix */
634 tmp = strchr(arg, '%');
635 if (tmp) {
636 if (!strcmp(tmp, "%return")) {
637 *tmp = '\0';
638 is_return = true;
639 } else {
640 trace_probe_log_err(tmp - filename, BAD_ADDR_SUFFIX);
641 ret = -EINVAL;
642 goto fail_address_parse;
643 }
644 }
645
646 /* Parse uprobe offset. */
647 ret = kstrtoul(arg, 0, &offset);
648 if (ret) {
649 trace_probe_log_err(arg - filename, BAD_UPROBE_OFFS);
650 goto fail_address_parse;
651 }
652
653 /* setup a probe */
654 trace_probe_log_set_index(0);
655 if (event) {
656 ret = traceprobe_parse_event_name(&event, &group, gbuf,
657 event - argv[0]);
658 if (ret)
659 goto fail_address_parse;
660 }
661
662 if (!event) {
663 char *tail;
664 char *ptr;
665
666 tail = kstrdup(kbasename(filename), GFP_KERNEL);
667 if (!tail) {
668 ret = -ENOMEM;
669 goto fail_address_parse;
670 }
671
672 ptr = strpbrk(tail, ".-_");
673 if (ptr)
674 *ptr = '\0';
675
676 snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_0x%lx", 'p', tail, offset);
677 event = buf;
678 kfree(tail);
679 }
680
681 argc -= 2;
682 argv += 2;
683
684 tu = alloc_trace_uprobe(group, event, argc, is_return);
685 if (IS_ERR(tu)) {
686 ret = PTR_ERR(tu);
687 /* This must return -ENOMEM otherwise there is a bug */
688 WARN_ON_ONCE(ret != -ENOMEM);
689 goto fail_address_parse;
690 }
691 tu->offset = offset;
692 tu->ref_ctr_offset = ref_ctr_offset;
693 tu->path = path;
694 tu->filename = filename;
695
696 /* parse arguments */
697 for (i = 0; i < argc; i++) {
698 struct traceprobe_parse_context ctx = {
699 .flags = (is_return ? TPARG_FL_RETURN : 0) | TPARG_FL_USER,
700 };
701
702 trace_probe_log_set_index(i + 2);
703 ret = traceprobe_parse_probe_arg(&tu->tp, i, argv[i], &ctx);
704 traceprobe_finish_parse(&ctx);
705 if (ret)
706 goto error;
707 }
708
709 ptype = is_ret_probe(tu) ? PROBE_PRINT_RETURN : PROBE_PRINT_NORMAL;
710 ret = traceprobe_set_print_fmt(&tu->tp, ptype);
711 if (ret < 0)
712 goto error;
713
714 ret = register_trace_uprobe(tu);
715 if (!ret)
716 goto out;
717
718 error:
719 free_trace_uprobe(tu);
720 out:
721 trace_probe_log_clear();
722 return ret;
723
724 fail_address_parse:
725 trace_probe_log_clear();
726 path_put(&path);
727 kfree(filename);
728
729 return ret;
730 }
731
732 int trace_uprobe_create(const char *raw_command)
733 {
734 return trace_probe_create(raw_command, __trace_uprobe_create);
735 }
736
737 static int create_or_delete_trace_uprobe(const char *raw_command)
738 {
739 int ret;
740
741 if (raw_command[0] == '-')
742 return dyn_event_release(raw_command, &trace_uprobe_ops);
743
744 ret = trace_uprobe_create(raw_command);
745 return ret == -ECANCELED ? -EINVAL : ret;
746 }
747
748 static int trace_uprobe_release(struct dyn_event *ev)
749 {
750 struct trace_uprobe *tu = to_trace_uprobe(ev);
751
752 return unregister_trace_uprobe(tu);
753 }
754
755 /* Probes listing interfaces */
756 static int trace_uprobe_show(struct seq_file *m, struct dyn_event *ev)
757 {
758 struct trace_uprobe *tu = to_trace_uprobe(ev);
759 char c = is_ret_probe(tu) ? 'r' : 'p';
760 int i;
761
762 seq_printf(m, "%c:%s/%s %s:0x%0*lx", c, trace_probe_group_name(&tu->tp),
763 trace_probe_name(&tu->tp), tu->filename,
764 (int)(sizeof(void *) * 2), tu->offset);
765
766 if (tu->ref_ctr_offset)
767 seq_printf(m, "(0x%lx)", tu->ref_ctr_offset);
768
769 for (i = 0; i < tu->tp.nr_args; i++)
770 seq_printf(m, " %s=%s", tu->tp.args[i].name, tu->tp.args[i].comm);
771
772 seq_putc(m, '\n');
773 return 0;
774 }
775
776 static int probes_seq_show(struct seq_file *m, void *v)
777 {
778 struct dyn_event *ev = v;
779
780 if (!is_trace_uprobe(ev))
781 return 0;
782
783 return trace_uprobe_show(m, ev);
784 }
785
786 static const struct seq_operations probes_seq_op = {
787 .start = dyn_event_seq_start,
788 .next = dyn_event_seq_next,
789 .stop = dyn_event_seq_stop,
790 .show = probes_seq_show
791 };
792
793 static int probes_open(struct inode *inode, struct file *file)
794 {
795 int ret;
796
797 ret = security_locked_down(LOCKDOWN_TRACEFS);
798 if (ret)
799 return ret;
800
801 if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
802 ret = dyn_events_release_all(&trace_uprobe_ops);
803 if (ret)
804 return ret;
805 }
806
807 return seq_open(file, &probes_seq_op);
808 }
809
810 static ssize_t probes_write(struct file *file, const char __user *buffer,
811 size_t count, loff_t *ppos)
812 {
813 return trace_parse_run_command(file, buffer, count, ppos,
814 create_or_delete_trace_uprobe);
815 }
816
817 static const struct file_operations uprobe_events_ops = {
818 .owner = THIS_MODULE,
819 .open = probes_open,
820 .read = seq_read,
821 .llseek = seq_lseek,
822 .release = seq_release,
823 .write = probes_write,
824 };
825
826 /* Probes profiling interfaces */
827 static int probes_profile_seq_show(struct seq_file *m, void *v)
828 {
829 struct dyn_event *ev = v;
830 struct trace_uprobe *tu;
831 unsigned long nhits;
832 int cpu;
833
834 if (!is_trace_uprobe(ev))
835 return 0;
836
837 tu = to_trace_uprobe(ev);
838
839 nhits = 0;
840 for_each_possible_cpu(cpu) {
841 nhits += per_cpu(*tu->nhits, cpu);
842 }
843
844 seq_printf(m, " %s %-44s %15lu\n", tu->filename,
845 trace_probe_name(&tu->tp), nhits);
846 return 0;
847 }
848
849 static const struct seq_operations profile_seq_op = {
850 .start = dyn_event_seq_start,
851 .next = dyn_event_seq_next,
852 .stop = dyn_event_seq_stop,
853 .show = probes_profile_seq_show
854 };
855
856 static int profile_open(struct inode *inode, struct file *file)
857 {
858 int ret;
859
860 ret = security_locked_down(LOCKDOWN_TRACEFS);
861 if (ret)
862 return ret;
863
864 return seq_open(file, &profile_seq_op);
865 }
866
867 static const struct file_operations uprobe_profile_ops = {
868 .owner = THIS_MODULE,
869 .open = profile_open,
870 .read = seq_read,
871 .llseek = seq_lseek,
872 .release = seq_release,
873 };
874
875 struct uprobe_cpu_buffer {
876 struct mutex mutex;
877 void *buf;
878 int dsize;
879 };
880 static struct uprobe_cpu_buffer __percpu *uprobe_cpu_buffer;
881 static int uprobe_buffer_refcnt;
882 #define MAX_UCB_BUFFER_SIZE PAGE_SIZE
883
884 static int uprobe_buffer_init(void)
885 {
886 int cpu, err_cpu;
887
888 uprobe_cpu_buffer = alloc_percpu(struct uprobe_cpu_buffer);
889 if (uprobe_cpu_buffer == NULL)
890 return -ENOMEM;
891
892 for_each_possible_cpu(cpu) {
893 struct page *p = alloc_pages_node(cpu_to_node(cpu),
894 GFP_KERNEL, 0);
895 if (p == NULL) {
896 err_cpu = cpu;
897 goto err;
898 }
899 per_cpu_ptr(uprobe_cpu_buffer, cpu)->buf = page_address(p);
900 mutex_init(&per_cpu_ptr(uprobe_cpu_buffer, cpu)->mutex);
901 }
902
903 return 0;
904
905 err:
906 for_each_possible_cpu(cpu) {
907 if (cpu == err_cpu)
908 break;
909 free_page((unsigned long)per_cpu_ptr(uprobe_cpu_buffer, cpu)->buf);
910 }
911
912 free_percpu(uprobe_cpu_buffer);
913 return -ENOMEM;
914 }
915
916 static int uprobe_buffer_enable(void)
917 {
918 int ret = 0;
919
920 BUG_ON(!mutex_is_locked(&event_mutex));
921
922 if (uprobe_buffer_refcnt++ == 0) {
923 ret = uprobe_buffer_init();
924 if (ret < 0)
925 uprobe_buffer_refcnt--;
926 }
927
928 return ret;
929 }
930
931 static void uprobe_buffer_disable(void)
932 {
933 int cpu;
934
935 BUG_ON(!mutex_is_locked(&event_mutex));
936
937 if (--uprobe_buffer_refcnt == 0) {
938 for_each_possible_cpu(cpu)
939 free_page((unsigned long)per_cpu_ptr(uprobe_cpu_buffer,
940 cpu)->buf);
941
942 free_percpu(uprobe_cpu_buffer);
943 uprobe_cpu_buffer = NULL;
944 }
945 }
946
947 static struct uprobe_cpu_buffer *uprobe_buffer_get(void)
948 {
949 struct uprobe_cpu_buffer *ucb;
950 int cpu;
951
952 cpu = raw_smp_processor_id();
953 ucb = per_cpu_ptr(uprobe_cpu_buffer, cpu);
954
955 /*
956 * Use per-cpu buffers for fastest access, but we might migrate
957 * so the mutex makes sure we have sole access to it.
958 */
959 mutex_lock(&ucb->mutex);
960
961 return ucb;
962 }
963
964 static void uprobe_buffer_put(struct uprobe_cpu_buffer *ucb)
965 {
966 if (!ucb)
967 return;
968 mutex_unlock(&ucb->mutex);
969 }
970
971 static struct uprobe_cpu_buffer *prepare_uprobe_buffer(struct trace_uprobe *tu,
972 struct pt_regs *regs,
973 struct uprobe_cpu_buffer **ucbp)
974 {
975 struct uprobe_cpu_buffer *ucb;
976 int dsize, esize;
977
978 if (*ucbp)
979 return *ucbp;
980
981 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
982 dsize = __get_data_size(&tu->tp, regs, NULL);
983
984 ucb = uprobe_buffer_get();
985 ucb->dsize = tu->tp.size + dsize;
986
987 if (WARN_ON_ONCE(ucb->dsize > MAX_UCB_BUFFER_SIZE)) {
988 ucb->dsize = MAX_UCB_BUFFER_SIZE;
989 dsize = MAX_UCB_BUFFER_SIZE - tu->tp.size;
990 }
991
992 store_trace_args(ucb->buf, &tu->tp, regs, NULL, esize, dsize);
993
994 *ucbp = ucb;
995 return ucb;
996 }
997
998 static void __uprobe_trace_func(struct trace_uprobe *tu,
999 unsigned long func, struct pt_regs *regs,
1000 struct uprobe_cpu_buffer *ucb,
1001 struct trace_event_file *trace_file)
1002 {
1003 struct uprobe_trace_entry_head *entry;
1004 struct trace_event_buffer fbuffer;
1005 void *data;
1006 int size, esize;
1007 struct trace_event_call *call = trace_probe_event_call(&tu->tp);
1008
1009 WARN_ON(call != trace_file->event_call);
1010
1011 if (trace_trigger_soft_disabled(trace_file))
1012 return;
1013
1014 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
1015 size = esize + ucb->dsize;
1016 entry = trace_event_buffer_reserve(&fbuffer, trace_file, size);
1017 if (!entry)
1018 return;
1019
1020 if (is_ret_probe(tu)) {
1021 entry->vaddr[0] = func;
1022 entry->vaddr[1] = instruction_pointer(regs);
1023 data = DATAOF_TRACE_ENTRY(entry, true);
1024 } else {
1025 entry->vaddr[0] = instruction_pointer(regs);
1026 data = DATAOF_TRACE_ENTRY(entry, false);
1027 }
1028
1029 memcpy(data, ucb->buf, ucb->dsize);
1030
1031 trace_event_buffer_commit(&fbuffer);
1032 }
1033
1034 /* uprobe handler */
1035 static int uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs,
1036 struct uprobe_cpu_buffer **ucbp)
1037 {
1038 struct event_file_link *link;
1039 struct uprobe_cpu_buffer *ucb;
1040
1041 if (is_ret_probe(tu))
1042 return 0;
1043
1044 ucb = prepare_uprobe_buffer(tu, regs, ucbp);
1045
1046 rcu_read_lock();
1047 trace_probe_for_each_link_rcu(link, &tu->tp)
1048 __uprobe_trace_func(tu, 0, regs, ucb, link->file);
1049 rcu_read_unlock();
1050
1051 return 0;
1052 }
1053
1054 static void uretprobe_trace_func(struct trace_uprobe *tu, unsigned long func,
1055 struct pt_regs *regs,
1056 struct uprobe_cpu_buffer **ucbp)
1057 {
1058 struct event_file_link *link;
1059 struct uprobe_cpu_buffer *ucb;
1060
1061 ucb = prepare_uprobe_buffer(tu, regs, ucbp);
1062
1063 rcu_read_lock();
1064 trace_probe_for_each_link_rcu(link, &tu->tp)
1065 __uprobe_trace_func(tu, func, regs, ucb, link->file);
1066 rcu_read_unlock();
1067 }
1068
1069 /* Event entry printers */
1070 static enum print_line_t
1071 print_uprobe_event(struct trace_iterator *iter, int flags, struct trace_event *event)
1072 {
1073 struct uprobe_trace_entry_head *entry;
1074 struct trace_seq *s = &iter->seq;
1075 struct trace_uprobe *tu;
1076 u8 *data;
1077
1078 entry = (struct uprobe_trace_entry_head *)iter->ent;
1079 tu = trace_uprobe_primary_from_call(
1080 container_of(event, struct trace_event_call, event));
1081 if (unlikely(!tu))
1082 goto out;
1083
1084 if (is_ret_probe(tu)) {
1085 trace_seq_printf(s, "%s: (0x%lx <- 0x%lx)",
1086 trace_probe_name(&tu->tp),
1087 entry->vaddr[1], entry->vaddr[0]);
1088 data = DATAOF_TRACE_ENTRY(entry, true);
1089 } else {
1090 trace_seq_printf(s, "%s: (0x%lx)",
1091 trace_probe_name(&tu->tp),
1092 entry->vaddr[0]);
1093 data = DATAOF_TRACE_ENTRY(entry, false);
1094 }
1095
1096 if (trace_probe_print_args(s, tu->tp.args, tu->tp.nr_args, data, entry) < 0)
1097 goto out;
1098
1099 trace_seq_putc(s, '\n');
1100
1101 out:
1102 return trace_handle_return(s);
1103 }
1104
1105 typedef bool (*filter_func_t)(struct uprobe_consumer *self, struct mm_struct *mm);
1106
1107 static int trace_uprobe_enable(struct trace_uprobe *tu, filter_func_t filter)
1108 {
1109 struct inode *inode = d_real_inode(tu->path.dentry);
1110 struct uprobe *uprobe;
1111
1112 tu->consumer.filter = filter;
1113 uprobe = uprobe_register(inode, tu->offset, tu->ref_ctr_offset, &tu->consumer);
1114 if (IS_ERR(uprobe))
1115 return PTR_ERR(uprobe);
1116
1117 tu->uprobe = uprobe;
1118 return 0;
1119 }
1120
1121 static void __probe_event_disable(struct trace_probe *tp)
1122 {
1123 struct trace_uprobe *tu;
1124 bool sync = false;
1125
1126 tu = container_of(tp, struct trace_uprobe, tp);
1127 WARN_ON(!uprobe_filter_is_empty(tu->tp.event->filter));
1128
1129 list_for_each_entry(tu, trace_probe_probe_list(tp), tp.list) {
1130 if (!tu->uprobe)
1131 continue;
1132
1133 uprobe_unregister_nosync(tu->uprobe, &tu->consumer);
1134 sync = true;
1135 tu->uprobe = NULL;
1136 }
1137 if (sync)
1138 uprobe_unregister_sync();
1139 }
1140
1141 static int probe_event_enable(struct trace_event_call *call,
1142 struct trace_event_file *file, filter_func_t filter)
1143 {
1144 struct trace_probe *tp;
1145 struct trace_uprobe *tu;
1146 bool enabled;
1147 int ret;
1148
1149 tp = trace_probe_primary_from_call(call);
1150 if (WARN_ON_ONCE(!tp))
1151 return -ENODEV;
1152 enabled = trace_probe_is_enabled(tp);
1153
1154 /* This may also change "enabled" state */
1155 if (file) {
1156 if (trace_probe_test_flag(tp, TP_FLAG_PROFILE))
1157 return -EINTR;
1158
1159 ret = trace_probe_add_file(tp, file);
1160 if (ret < 0)
1161 return ret;
1162 } else {
1163 if (trace_probe_test_flag(tp, TP_FLAG_TRACE))
1164 return -EINTR;
1165
1166 trace_probe_set_flag(tp, TP_FLAG_PROFILE);
1167 }
1168
1169 tu = container_of(tp, struct trace_uprobe, tp);
1170 WARN_ON(!uprobe_filter_is_empty(tu->tp.event->filter));
1171
1172 if (enabled)
1173 return 0;
1174
1175 ret = uprobe_buffer_enable();
1176 if (ret)
1177 goto err_flags;
1178
1179 list_for_each_entry(tu, trace_probe_probe_list(tp), tp.list) {
1180 ret = trace_uprobe_enable(tu, filter);
1181 if (ret) {
1182 __probe_event_disable(tp);
1183 goto err_buffer;
1184 }
1185 }
1186
1187 return 0;
1188
1189 err_buffer:
1190 uprobe_buffer_disable();
1191
1192 err_flags:
1193 if (file)
1194 trace_probe_remove_file(tp, file);
1195 else
1196 trace_probe_clear_flag(tp, TP_FLAG_PROFILE);
1197
1198 return ret;
1199 }
1200
1201 static void probe_event_disable(struct trace_event_call *call,
1202 struct trace_event_file *file)
1203 {
1204 struct trace_probe *tp;
1205
1206 tp = trace_probe_primary_from_call(call);
1207 if (WARN_ON_ONCE(!tp))
1208 return;
1209
1210 if (!trace_probe_is_enabled(tp))
1211 return;
1212
1213 if (file) {
1214 if (trace_probe_remove_file(tp, file) < 0)
1215 return;
1216
1217 if (trace_probe_is_enabled(tp))
1218 return;
1219 } else
1220 trace_probe_clear_flag(tp, TP_FLAG_PROFILE);
1221
1222 __probe_event_disable(tp);
1223 uprobe_buffer_disable();
1224 }
1225
1226 static int uprobe_event_define_fields(struct trace_event_call *event_call)
1227 {
1228 int ret, size;
1229 struct uprobe_trace_entry_head field;
1230 struct trace_uprobe *tu;
1231
1232 tu = trace_uprobe_primary_from_call(event_call);
1233 if (unlikely(!tu))
1234 return -ENODEV;
1235
1236 if (is_ret_probe(tu)) {
1237 DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_FUNC, 0);
1238 DEFINE_FIELD(unsigned long, vaddr[1], FIELD_STRING_RETIP, 0);
1239 size = SIZEOF_TRACE_ENTRY(true);
1240 } else {
1241 DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_IP, 0);
1242 size = SIZEOF_TRACE_ENTRY(false);
1243 }
1244
1245 return traceprobe_define_arg_fields(event_call, size, &tu->tp);
1246 }
1247
1248 #ifdef CONFIG_PERF_EVENTS
1249 static bool
1250 __uprobe_perf_filter(struct trace_uprobe_filter *filter, struct mm_struct *mm)
1251 {
1252 struct perf_event *event;
1253
1254 list_for_each_entry(event, &filter->perf_events, hw.tp_list) {
1255 if (event->hw.target->mm == mm)
1256 return true;
1257 }
1258
1259 return false;
1260 }
1261
1262 static inline bool
1263 trace_uprobe_filter_event(struct trace_uprobe_filter *filter,
1264 struct perf_event *event)
1265 {
1266 return __uprobe_perf_filter(filter, event->hw.target->mm);
1267 }
1268
1269 static bool trace_uprobe_filter_remove(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 list_del(&event->hw.tp_list);
1277 done = filter->nr_systemwide ||
1278 (event->hw.target->flags & PF_EXITING) ||
1279 trace_uprobe_filter_event(filter, event);
1280 } else {
1281 filter->nr_systemwide--;
1282 done = filter->nr_systemwide;
1283 }
1284 write_unlock(&filter->rwlock);
1285
1286 return done;
1287 }
1288
1289 /* This returns true if the filter always covers target mm */
1290 static bool trace_uprobe_filter_add(struct trace_uprobe_filter *filter,
1291 struct perf_event *event)
1292 {
1293 bool done;
1294
1295 write_lock(&filter->rwlock);
1296 if (event->hw.target) {
1297 /*
1298 * event->parent != NULL means copy_process(), we can avoid
1299 * uprobe_apply(). current->mm must be probed and we can rely
1300 * on dup_mmap() which preserves the already installed bp's.
1301 *
1302 * attr.enable_on_exec means that exec/mmap will install the
1303 * breakpoints we need.
1304 */
1305 done = filter->nr_systemwide ||
1306 event->parent || event->attr.enable_on_exec ||
1307 trace_uprobe_filter_event(filter, event);
1308 list_add(&event->hw.tp_list, &filter->perf_events);
1309 } else {
1310 done = filter->nr_systemwide;
1311 filter->nr_systemwide++;
1312 }
1313 write_unlock(&filter->rwlock);
1314
1315 return done;
1316 }
1317
1318 static int uprobe_perf_close(struct trace_event_call *call,
1319 struct perf_event *event)
1320 {
1321 struct trace_probe *tp;
1322 struct trace_uprobe *tu;
1323 int ret = 0;
1324
1325 tp = trace_probe_primary_from_call(call);
1326 if (WARN_ON_ONCE(!tp))
1327 return -ENODEV;
1328
1329 tu = container_of(tp, struct trace_uprobe, tp);
1330 if (trace_uprobe_filter_remove(tu->tp.event->filter, event))
1331 return 0;
1332
1333 list_for_each_entry(tu, trace_probe_probe_list(tp), tp.list) {
1334 ret = uprobe_apply(tu->uprobe, &tu->consumer, false);
1335 if (ret)
1336 break;
1337 }
1338
1339 return ret;
1340 }
1341
1342 static int uprobe_perf_open(struct trace_event_call *call,
1343 struct perf_event *event)
1344 {
1345 struct trace_probe *tp;
1346 struct trace_uprobe *tu;
1347 int err = 0;
1348
1349 tp = trace_probe_primary_from_call(call);
1350 if (WARN_ON_ONCE(!tp))
1351 return -ENODEV;
1352
1353 tu = container_of(tp, struct trace_uprobe, tp);
1354 if (trace_uprobe_filter_add(tu->tp.event->filter, event))
1355 return 0;
1356
1357 list_for_each_entry(tu, trace_probe_probe_list(tp), tp.list) {
1358 err = uprobe_apply(tu->uprobe, &tu->consumer, true);
1359 if (err) {
1360 uprobe_perf_close(call, event);
1361 break;
1362 }
1363 }
1364
1365 return err;
1366 }
1367
1368 static bool uprobe_perf_filter(struct uprobe_consumer *uc, struct mm_struct *mm)
1369 {
1370 struct trace_uprobe_filter *filter;
1371 struct trace_uprobe *tu;
1372 int ret;
1373
1374 tu = container_of(uc, struct trace_uprobe, consumer);
1375 filter = tu->tp.event->filter;
1376
1377 /*
1378 * speculative short-circuiting check to avoid unnecessarily taking
1379 * filter->rwlock below, if the uprobe has system-wide consumer
1380 */
1381 if (READ_ONCE(filter->nr_systemwide))
1382 return true;
1383
1384 read_lock(&filter->rwlock);
1385 ret = __uprobe_perf_filter(filter, mm);
1386 read_unlock(&filter->rwlock);
1387
1388 return ret;
1389 }
1390
1391 static void __uprobe_perf_func(struct trace_uprobe *tu,
1392 unsigned long func, struct pt_regs *regs,
1393 struct uprobe_cpu_buffer **ucbp)
1394 {
1395 struct trace_event_call *call = trace_probe_event_call(&tu->tp);
1396 struct uprobe_trace_entry_head *entry;
1397 struct uprobe_cpu_buffer *ucb;
1398 struct hlist_head *head;
1399 void *data;
1400 int size, esize;
1401 int rctx;
1402
1403 #ifdef CONFIG_BPF_EVENTS
1404 if (bpf_prog_array_valid(call)) {
1405 u32 ret;
1406
1407 ret = bpf_prog_run_array_uprobe(call->prog_array, regs, bpf_prog_run);
1408 if (!ret)
1409 return;
1410 }
1411 #endif /* CONFIG_BPF_EVENTS */
1412
1413 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
1414
1415 ucb = prepare_uprobe_buffer(tu, regs, ucbp);
1416 size = esize + ucb->dsize;
1417 size = ALIGN(size + sizeof(u32), sizeof(u64)) - sizeof(u32);
1418 if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, "profile buffer not large enough"))
1419 return;
1420
1421 preempt_disable();
1422 head = this_cpu_ptr(call->perf_events);
1423 if (hlist_empty(head))
1424 goto out;
1425
1426 entry = perf_trace_buf_alloc(size, NULL, &rctx);
1427 if (!entry)
1428 goto out;
1429
1430 if (is_ret_probe(tu)) {
1431 entry->vaddr[0] = func;
1432 entry->vaddr[1] = instruction_pointer(regs);
1433 data = DATAOF_TRACE_ENTRY(entry, true);
1434 } else {
1435 entry->vaddr[0] = instruction_pointer(regs);
1436 data = DATAOF_TRACE_ENTRY(entry, false);
1437 }
1438
1439 memcpy(data, ucb->buf, ucb->dsize);
1440
1441 if (size - esize > ucb->dsize)
1442 memset(data + ucb->dsize, 0, size - esize - ucb->dsize);
1443
1444 perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs,
1445 head, NULL);
1446 out:
1447 preempt_enable();
1448 }
1449
1450 /* uprobe profile handler */
1451 static int uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs,
1452 struct uprobe_cpu_buffer **ucbp)
1453 {
1454 if (!uprobe_perf_filter(&tu->consumer, current->mm))
1455 return UPROBE_HANDLER_REMOVE;
1456
1457 if (!is_ret_probe(tu))
1458 __uprobe_perf_func(tu, 0, regs, ucbp);
1459 return 0;
1460 }
1461
1462 static void uretprobe_perf_func(struct trace_uprobe *tu, unsigned long func,
1463 struct pt_regs *regs,
1464 struct uprobe_cpu_buffer **ucbp)
1465 {
1466 __uprobe_perf_func(tu, func, regs, ucbp);
1467 }
1468
1469 int bpf_get_uprobe_info(const struct perf_event *event, u32 *fd_type,
1470 const char **filename, u64 *probe_offset,
1471 u64 *probe_addr, bool perf_type_tracepoint)
1472 {
1473 const char *pevent = trace_event_name(event->tp_event);
1474 const char *group = event->tp_event->class->system;
1475 struct trace_uprobe *tu;
1476
1477 if (perf_type_tracepoint)
1478 tu = find_probe_event(pevent, group);
1479 else
1480 tu = trace_uprobe_primary_from_call(event->tp_event);
1481 if (!tu)
1482 return -EINVAL;
1483
1484 *fd_type = is_ret_probe(tu) ? BPF_FD_TYPE_URETPROBE
1485 : BPF_FD_TYPE_UPROBE;
1486 *filename = tu->filename;
1487 *probe_offset = tu->offset;
1488 *probe_addr = 0;
1489 return 0;
1490 }
1491 #endif /* CONFIG_PERF_EVENTS */
1492
1493 static int
1494 trace_uprobe_register(struct trace_event_call *event, enum trace_reg type,
1495 void *data)
1496 {
1497 struct trace_event_file *file = data;
1498
1499 switch (type) {
1500 case TRACE_REG_REGISTER:
1501 return probe_event_enable(event, file, NULL);
1502
1503 case TRACE_REG_UNREGISTER:
1504 probe_event_disable(event, file);
1505 return 0;
1506
1507 #ifdef CONFIG_PERF_EVENTS
1508 case TRACE_REG_PERF_REGISTER:
1509 return probe_event_enable(event, NULL, uprobe_perf_filter);
1510
1511 case TRACE_REG_PERF_UNREGISTER:
1512 probe_event_disable(event, NULL);
1513 return 0;
1514
1515 case TRACE_REG_PERF_OPEN:
1516 return uprobe_perf_open(event, data);
1517
1518 case TRACE_REG_PERF_CLOSE:
1519 return uprobe_perf_close(event, data);
1520
1521 #endif
1522 default:
1523 return 0;
1524 }
1525 }
1526
1527 static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs,
1528 __u64 *data)
1529 {
1530 struct trace_uprobe *tu;
1531 struct uprobe_dispatch_data udd;
1532 struct uprobe_cpu_buffer *ucb = NULL;
1533 int ret = 0;
1534
1535 tu = container_of(con, struct trace_uprobe, consumer);
1536
1537 this_cpu_inc(*tu->nhits);
1538
1539 udd.tu = tu;
1540 udd.bp_addr = instruction_pointer(regs);
1541
1542 current->utask->vaddr = (unsigned long) &udd;
1543
1544 if (WARN_ON_ONCE(!uprobe_cpu_buffer))
1545 return 0;
1546
1547 if (trace_probe_test_flag(&tu->tp, TP_FLAG_TRACE))
1548 ret |= uprobe_trace_func(tu, regs, &ucb);
1549
1550 #ifdef CONFIG_PERF_EVENTS
1551 if (trace_probe_test_flag(&tu->tp, TP_FLAG_PROFILE))
1552 ret |= uprobe_perf_func(tu, regs, &ucb);
1553 #endif
1554 uprobe_buffer_put(ucb);
1555 return ret;
1556 }
1557
1558 static int uretprobe_dispatcher(struct uprobe_consumer *con,
1559 unsigned long func, struct pt_regs *regs,
1560 __u64 *data)
1561 {
1562 struct trace_uprobe *tu;
1563 struct uprobe_dispatch_data udd;
1564 struct uprobe_cpu_buffer *ucb = NULL;
1565
1566 tu = container_of(con, struct trace_uprobe, consumer);
1567
1568 udd.tu = tu;
1569 udd.bp_addr = func;
1570
1571 current->utask->vaddr = (unsigned long) &udd;
1572
1573 if (WARN_ON_ONCE(!uprobe_cpu_buffer))
1574 return 0;
1575
1576 if (trace_probe_test_flag(&tu->tp, TP_FLAG_TRACE))
1577 uretprobe_trace_func(tu, func, regs, &ucb);
1578
1579 #ifdef CONFIG_PERF_EVENTS
1580 if (trace_probe_test_flag(&tu->tp, TP_FLAG_PROFILE))
1581 uretprobe_perf_func(tu, func, regs, &ucb);
1582 #endif
1583 uprobe_buffer_put(ucb);
1584 return 0;
1585 }
1586
1587 static struct trace_event_functions uprobe_funcs = {
1588 .trace = print_uprobe_event
1589 };
1590
1591 static struct trace_event_fields uprobe_fields_array[] = {
1592 { .type = TRACE_FUNCTION_TYPE,
1593 .define_fields = uprobe_event_define_fields },
1594 {}
1595 };
1596
1597 static inline void init_trace_event_call(struct trace_uprobe *tu)
1598 {
1599 struct trace_event_call *call = trace_probe_event_call(&tu->tp);
1600 call->event.funcs = &uprobe_funcs;
1601 call->class->fields_array = uprobe_fields_array;
1602
1603 call->flags = TRACE_EVENT_FL_UPROBE | TRACE_EVENT_FL_CAP_ANY;
1604 call->class->reg = trace_uprobe_register;
1605 }
1606
1607 static int register_uprobe_event(struct trace_uprobe *tu)
1608 {
1609 init_trace_event_call(tu);
1610
1611 return trace_probe_register_event_call(&tu->tp);
1612 }
1613
1614 static int unregister_uprobe_event(struct trace_uprobe *tu)
1615 {
1616 return trace_probe_unregister_event_call(&tu->tp);
1617 }
1618
1619 #ifdef CONFIG_PERF_EVENTS
1620 struct trace_event_call *
1621 create_local_trace_uprobe(char *name, unsigned long offs,
1622 unsigned long ref_ctr_offset, bool is_return)
1623 {
1624 enum probe_print_type ptype;
1625 struct trace_uprobe *tu;
1626 struct path path;
1627 int ret;
1628
1629 ret = kern_path(name, LOOKUP_FOLLOW, &path);
1630 if (ret)
1631 return ERR_PTR(ret);
1632
1633 if (!d_is_reg(path.dentry)) {
1634 path_put(&path);
1635 return ERR_PTR(-EINVAL);
1636 }
1637
1638 /*
1639 * local trace_kprobes are not added to dyn_event, so they are never
1640 * searched in find_trace_kprobe(). Therefore, there is no concern of
1641 * duplicated name "DUMMY_EVENT" here.
1642 */
1643 tu = alloc_trace_uprobe(UPROBE_EVENT_SYSTEM, "DUMMY_EVENT", 0,
1644 is_return);
1645
1646 if (IS_ERR(tu)) {
1647 pr_info("Failed to allocate trace_uprobe.(%d)\n",
1648 (int)PTR_ERR(tu));
1649 path_put(&path);
1650 return ERR_CAST(tu);
1651 }
1652
1653 tu->offset = offs;
1654 tu->path = path;
1655 tu->ref_ctr_offset = ref_ctr_offset;
1656 tu->filename = kstrdup(name, GFP_KERNEL);
1657 if (!tu->filename) {
1658 ret = -ENOMEM;
1659 goto error;
1660 }
1661
1662 init_trace_event_call(tu);
1663
1664 ptype = is_ret_probe(tu) ? PROBE_PRINT_RETURN : PROBE_PRINT_NORMAL;
1665 if (traceprobe_set_print_fmt(&tu->tp, ptype) < 0) {
1666 ret = -ENOMEM;
1667 goto error;
1668 }
1669
1670 return trace_probe_event_call(&tu->tp);
1671 error:
1672 free_trace_uprobe(tu);
1673 return ERR_PTR(ret);
1674 }
1675
1676 void destroy_local_trace_uprobe(struct trace_event_call *event_call)
1677 {
1678 struct trace_uprobe *tu;
1679
1680 tu = trace_uprobe_primary_from_call(event_call);
1681
1682 free_trace_uprobe(tu);
1683 }
1684 #endif /* CONFIG_PERF_EVENTS */
1685
1686 /* Make a trace interface for controlling probe points */
1687 static __init int init_uprobe_trace(void)
1688 {
1689 int ret;
1690
1691 ret = dyn_event_register(&trace_uprobe_ops);
1692 if (ret)
1693 return ret;
1694
1695 ret = tracing_init_dentry();
1696 if (ret)
1697 return 0;
1698
1699 trace_create_file("uprobe_events", TRACE_MODE_WRITE, NULL,
1700 NULL, &uprobe_events_ops);
1701 /* Profile interface */
1702 trace_create_file("uprobe_profile", TRACE_MODE_READ, NULL,
1703 NULL, &uprobe_profile_ops);
1704 return 0;
1705 }
1706
1707 fs_initcall(init_uprobe_trace);
Kernel DRM miscellaneous fixes and cross-tree changes