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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
27struct 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
39static int trace_uprobe_create(const char *raw_command);
40static int trace_uprobe_show(struct seq_file *m, struct dyn_event *ev);
41static int trace_uprobe_release(struct dyn_event *ev);
42static bool trace_uprobe_is_busy(struct dyn_event *ev);
43static bool trace_uprobe_match(const char *system, const char *event,
44 int argc, const char **argv, struct dyn_event *ev);
45
46static 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 */
57struct 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
69static bool is_trace_uprobe(struct dyn_event *ev)
70{
71 return ev->ops == &trace_uprobe_ops;
72}
73
74static 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
88static int register_uprobe_event(struct trace_uprobe *tu);
89static int unregister_uprobe_event(struct trace_uprobe *tu);
90
91static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs);
92static int uretprobe_dispatcher(struct uprobe_consumer *con,
93 unsigned long func, struct pt_regs *regs);
94
95#ifdef CONFIG_STACK_GROWSUP
96static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n)
97{
98 return addr - (n * sizeof(long));
99}
100#else
101static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n)
102{
103 return addr + (n * sizeof(long));
104}
105#endif
106
107static 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 */
123static nokprobe_inline int
124probe_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
131static nokprobe_inline int
132probe_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 */
141static nokprobe_inline int
142fetch_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
174static nokprobe_inline int
175fetch_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 */
181static nokprobe_inline int
182fetch_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
195static nokprobe_inline int
196fetch_store_strlen_user(unsigned long addr)
197{
198 return fetch_store_strlen(addr);
199}
200
201static 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 */
213static int
214process_fetch_insn(struct fetch_insn *code, void *rec, void *dest,
215 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}
250NOKPROBE_SYMBOL(process_fetch_insn)
251
252static 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
259static inline bool uprobe_filter_is_empty(struct trace_uprobe_filter *filter)
260{
261 return !filter->nr_systemwide && list_empty(&filter->perf_events);
262}
263
264static inline bool is_ret_probe(struct trace_uprobe *tu)
265{
266 return tu->consumer.ret_handler != NULL;
267}
268
269static 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
276static 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
304static 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
315static nokprobe_inline struct trace_uprobe *
316trace_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 */
330static struct trace_uprobe *
331alloc_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);
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
351error:
352 kfree(tu);
353
354 return ERR_PTR(ret);
355}
356
357static 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
368static 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 */
382static 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
397unreg:
398 dyn_event_remove(&tu->devent);
399 trace_probe_unlink(&tu->tp);
400 free_trace_uprobe(tu);
401 return 0;
402}
403
404static 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
433static 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 */
467static 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 */
485static 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
522end:
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 */
532static 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
705error:
706 free_trace_uprobe(tu);
707out:
708 trace_probe_log_clear();
709 return ret;
710
711fail_address_parse:
712 trace_probe_log_clear();
713 path_put(&path);
714 kfree(filename);
715
716 return ret;
717}
718
719int trace_uprobe_create(const char *raw_command)
720{
721 return trace_probe_create(raw_command, __trace_uprobe_create);
722}
723
724static 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
735static 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 */
743static 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
763static 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
773static 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
780static 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
797static 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
804static 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 */
814static 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
828static 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
835static 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
846static 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
854struct uprobe_cpu_buffer {
855 struct mutex mutex;
856 void *buf;
857};
858static struct uprobe_cpu_buffer __percpu *uprobe_cpu_buffer;
859static int uprobe_buffer_refcnt;
860
861static int uprobe_buffer_init(void)
862{
863 int cpu, err_cpu;
864
865 uprobe_cpu_buffer = alloc_percpu(struct uprobe_cpu_buffer);
866 if (uprobe_cpu_buffer == NULL)
867 return -ENOMEM;
868
869 for_each_possible_cpu(cpu) {
870 struct page *p = alloc_pages_node(cpu_to_node(cpu),
871 GFP_KERNEL, 0);
872 if (p == NULL) {
873 err_cpu = cpu;
874 goto err;
875 }
876 per_cpu_ptr(uprobe_cpu_buffer, cpu)->buf = page_address(p);
877 mutex_init(&per_cpu_ptr(uprobe_cpu_buffer, cpu)->mutex);
878 }
879
880 return 0;
881
882err:
883 for_each_possible_cpu(cpu) {
884 if (cpu == err_cpu)
885 break;
886 free_page((unsigned long)per_cpu_ptr(uprobe_cpu_buffer, cpu)->buf);
887 }
888
889 free_percpu(uprobe_cpu_buffer);
890 return -ENOMEM;
891}
892
893static int uprobe_buffer_enable(void)
894{
895 int ret = 0;
896
897 BUG_ON(!mutex_is_locked(&event_mutex));
898
899 if (uprobe_buffer_refcnt++ == 0) {
900 ret = uprobe_buffer_init();
901 if (ret < 0)
902 uprobe_buffer_refcnt--;
903 }
904
905 return ret;
906}
907
908static void uprobe_buffer_disable(void)
909{
910 int cpu;
911
912 BUG_ON(!mutex_is_locked(&event_mutex));
913
914 if (--uprobe_buffer_refcnt == 0) {
915 for_each_possible_cpu(cpu)
916 free_page((unsigned long)per_cpu_ptr(uprobe_cpu_buffer,
917 cpu)->buf);
918
919 free_percpu(uprobe_cpu_buffer);
920 uprobe_cpu_buffer = NULL;
921 }
922}
923
924static struct uprobe_cpu_buffer *uprobe_buffer_get(void)
925{
926 struct uprobe_cpu_buffer *ucb;
927 int cpu;
928
929 cpu = raw_smp_processor_id();
930 ucb = per_cpu_ptr(uprobe_cpu_buffer, cpu);
931
932 /*
933 * Use per-cpu buffers for fastest access, but we might migrate
934 * so the mutex makes sure we have sole access to it.
935 */
936 mutex_lock(&ucb->mutex);
937
938 return ucb;
939}
940
941static void uprobe_buffer_put(struct uprobe_cpu_buffer *ucb)
942{
943 mutex_unlock(&ucb->mutex);
944}
945
946static void __uprobe_trace_func(struct trace_uprobe *tu,
947 unsigned long func, struct pt_regs *regs,
948 struct uprobe_cpu_buffer *ucb, int dsize,
949 struct trace_event_file *trace_file)
950{
951 struct uprobe_trace_entry_head *entry;
952 struct trace_event_buffer fbuffer;
953 void *data;
954 int size, esize;
955 struct trace_event_call *call = trace_probe_event_call(&tu->tp);
956
957 WARN_ON(call != trace_file->event_call);
958
959 if (WARN_ON_ONCE(tu->tp.size + dsize > PAGE_SIZE))
960 return;
961
962 if (trace_trigger_soft_disabled(trace_file))
963 return;
964
965 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
966 size = esize + tu->tp.size + dsize;
967 entry = trace_event_buffer_reserve(&fbuffer, trace_file, size);
968 if (!entry)
969 return;
970
971 if (is_ret_probe(tu)) {
972 entry->vaddr[0] = func;
973 entry->vaddr[1] = instruction_pointer(regs);
974 data = DATAOF_TRACE_ENTRY(entry, true);
975 } else {
976 entry->vaddr[0] = instruction_pointer(regs);
977 data = DATAOF_TRACE_ENTRY(entry, false);
978 }
979
980 memcpy(data, ucb->buf, tu->tp.size + dsize);
981
982 trace_event_buffer_commit(&fbuffer);
983}
984
985/* uprobe handler */
986static int uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs,
987 struct uprobe_cpu_buffer *ucb, int dsize)
988{
989 struct event_file_link *link;
990
991 if (is_ret_probe(tu))
992 return 0;
993
994 rcu_read_lock();
995 trace_probe_for_each_link_rcu(link, &tu->tp)
996 __uprobe_trace_func(tu, 0, regs, ucb, dsize, link->file);
997 rcu_read_unlock();
998
999 return 0;
1000}
1001
1002static void uretprobe_trace_func(struct trace_uprobe *tu, unsigned long func,
1003 struct pt_regs *regs,
1004 struct uprobe_cpu_buffer *ucb, int dsize)
1005{
1006 struct event_file_link *link;
1007
1008 rcu_read_lock();
1009 trace_probe_for_each_link_rcu(link, &tu->tp)
1010 __uprobe_trace_func(tu, func, regs, ucb, dsize, link->file);
1011 rcu_read_unlock();
1012}
1013
1014/* Event entry printers */
1015static enum print_line_t
1016print_uprobe_event(struct trace_iterator *iter, int flags, struct trace_event *event)
1017{
1018 struct uprobe_trace_entry_head *entry;
1019 struct trace_seq *s = &iter->seq;
1020 struct trace_uprobe *tu;
1021 u8 *data;
1022
1023 entry = (struct uprobe_trace_entry_head *)iter->ent;
1024 tu = trace_uprobe_primary_from_call(
1025 container_of(event, struct trace_event_call, event));
1026 if (unlikely(!tu))
1027 goto out;
1028
1029 if (is_ret_probe(tu)) {
1030 trace_seq_printf(s, "%s: (0x%lx <- 0x%lx)",
1031 trace_probe_name(&tu->tp),
1032 entry->vaddr[1], entry->vaddr[0]);
1033 data = DATAOF_TRACE_ENTRY(entry, true);
1034 } else {
1035 trace_seq_printf(s, "%s: (0x%lx)",
1036 trace_probe_name(&tu->tp),
1037 entry->vaddr[0]);
1038 data = DATAOF_TRACE_ENTRY(entry, false);
1039 }
1040
1041 if (trace_probe_print_args(s, tu->tp.args, tu->tp.nr_args, data, entry) < 0)
1042 goto out;
1043
1044 trace_seq_putc(s, '\n');
1045
1046 out:
1047 return trace_handle_return(s);
1048}
1049
1050typedef bool (*filter_func_t)(struct uprobe_consumer *self,
1051 enum uprobe_filter_ctx ctx,
1052 struct mm_struct *mm);
1053
1054static int trace_uprobe_enable(struct trace_uprobe *tu, filter_func_t filter)
1055{
1056 int ret;
1057
1058 tu->consumer.filter = filter;
1059 tu->inode = d_real_inode(tu->path.dentry);
1060
1061 if (tu->ref_ctr_offset)
1062 ret = uprobe_register_refctr(tu->inode, tu->offset,
1063 tu->ref_ctr_offset, &tu->consumer);
1064 else
1065 ret = uprobe_register(tu->inode, tu->offset, &tu->consumer);
1066
1067 if (ret)
1068 tu->inode = NULL;
1069
1070 return ret;
1071}
1072
1073static void __probe_event_disable(struct trace_probe *tp)
1074{
1075 struct trace_uprobe *tu;
1076
1077 tu = container_of(tp, struct trace_uprobe, tp);
1078 WARN_ON(!uprobe_filter_is_empty(tu->tp.event->filter));
1079
1080 list_for_each_entry(tu, trace_probe_probe_list(tp), tp.list) {
1081 if (!tu->inode)
1082 continue;
1083
1084 uprobe_unregister(tu->inode, tu->offset, &tu->consumer);
1085 tu->inode = NULL;
1086 }
1087}
1088
1089static int probe_event_enable(struct trace_event_call *call,
1090 struct trace_event_file *file, filter_func_t filter)
1091{
1092 struct trace_probe *tp;
1093 struct trace_uprobe *tu;
1094 bool enabled;
1095 int ret;
1096
1097 tp = trace_probe_primary_from_call(call);
1098 if (WARN_ON_ONCE(!tp))
1099 return -ENODEV;
1100 enabled = trace_probe_is_enabled(tp);
1101
1102 /* This may also change "enabled" state */
1103 if (file) {
1104 if (trace_probe_test_flag(tp, TP_FLAG_PROFILE))
1105 return -EINTR;
1106
1107 ret = trace_probe_add_file(tp, file);
1108 if (ret < 0)
1109 return ret;
1110 } else {
1111 if (trace_probe_test_flag(tp, TP_FLAG_TRACE))
1112 return -EINTR;
1113
1114 trace_probe_set_flag(tp, TP_FLAG_PROFILE);
1115 }
1116
1117 tu = container_of(tp, struct trace_uprobe, tp);
1118 WARN_ON(!uprobe_filter_is_empty(tu->tp.event->filter));
1119
1120 if (enabled)
1121 return 0;
1122
1123 ret = uprobe_buffer_enable();
1124 if (ret)
1125 goto err_flags;
1126
1127 list_for_each_entry(tu, trace_probe_probe_list(tp), tp.list) {
1128 ret = trace_uprobe_enable(tu, filter);
1129 if (ret) {
1130 __probe_event_disable(tp);
1131 goto err_buffer;
1132 }
1133 }
1134
1135 return 0;
1136
1137 err_buffer:
1138 uprobe_buffer_disable();
1139
1140 err_flags:
1141 if (file)
1142 trace_probe_remove_file(tp, file);
1143 else
1144 trace_probe_clear_flag(tp, TP_FLAG_PROFILE);
1145
1146 return ret;
1147}
1148
1149static void probe_event_disable(struct trace_event_call *call,
1150 struct trace_event_file *file)
1151{
1152 struct trace_probe *tp;
1153
1154 tp = trace_probe_primary_from_call(call);
1155 if (WARN_ON_ONCE(!tp))
1156 return;
1157
1158 if (!trace_probe_is_enabled(tp))
1159 return;
1160
1161 if (file) {
1162 if (trace_probe_remove_file(tp, file) < 0)
1163 return;
1164
1165 if (trace_probe_is_enabled(tp))
1166 return;
1167 } else
1168 trace_probe_clear_flag(tp, TP_FLAG_PROFILE);
1169
1170 __probe_event_disable(tp);
1171 uprobe_buffer_disable();
1172}
1173
1174static int uprobe_event_define_fields(struct trace_event_call *event_call)
1175{
1176 int ret, size;
1177 struct uprobe_trace_entry_head field;
1178 struct trace_uprobe *tu;
1179
1180 tu = trace_uprobe_primary_from_call(event_call);
1181 if (unlikely(!tu))
1182 return -ENODEV;
1183
1184 if (is_ret_probe(tu)) {
1185 DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_FUNC, 0);
1186 DEFINE_FIELD(unsigned long, vaddr[1], FIELD_STRING_RETIP, 0);
1187 size = SIZEOF_TRACE_ENTRY(true);
1188 } else {
1189 DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_IP, 0);
1190 size = SIZEOF_TRACE_ENTRY(false);
1191 }
1192
1193 return traceprobe_define_arg_fields(event_call, size, &tu->tp);
1194}
1195
1196#ifdef CONFIG_PERF_EVENTS
1197static bool
1198__uprobe_perf_filter(struct trace_uprobe_filter *filter, struct mm_struct *mm)
1199{
1200 struct perf_event *event;
1201
1202 if (filter->nr_systemwide)
1203 return true;
1204
1205 list_for_each_entry(event, &filter->perf_events, hw.tp_list) {
1206 if (event->hw.target->mm == mm)
1207 return true;
1208 }
1209
1210 return false;
1211}
1212
1213static inline bool
1214trace_uprobe_filter_event(struct trace_uprobe_filter *filter,
1215 struct perf_event *event)
1216{
1217 return __uprobe_perf_filter(filter, event->hw.target->mm);
1218}
1219
1220static bool trace_uprobe_filter_remove(struct trace_uprobe_filter *filter,
1221 struct perf_event *event)
1222{
1223 bool done;
1224
1225 write_lock(&filter->rwlock);
1226 if (event->hw.target) {
1227 list_del(&event->hw.tp_list);
1228 done = filter->nr_systemwide ||
1229 (event->hw.target->flags & PF_EXITING) ||
1230 trace_uprobe_filter_event(filter, event);
1231 } else {
1232 filter->nr_systemwide--;
1233 done = filter->nr_systemwide;
1234 }
1235 write_unlock(&filter->rwlock);
1236
1237 return done;
1238}
1239
1240/* This returns true if the filter always covers target mm */
1241static bool trace_uprobe_filter_add(struct trace_uprobe_filter *filter,
1242 struct perf_event *event)
1243{
1244 bool done;
1245
1246 write_lock(&filter->rwlock);
1247 if (event->hw.target) {
1248 /*
1249 * event->parent != NULL means copy_process(), we can avoid
1250 * uprobe_apply(). current->mm must be probed and we can rely
1251 * on dup_mmap() which preserves the already installed bp's.
1252 *
1253 * attr.enable_on_exec means that exec/mmap will install the
1254 * breakpoints we need.
1255 */
1256 done = filter->nr_systemwide ||
1257 event->parent || event->attr.enable_on_exec ||
1258 trace_uprobe_filter_event(filter, event);
1259 list_add(&event->hw.tp_list, &filter->perf_events);
1260 } else {
1261 done = filter->nr_systemwide;
1262 filter->nr_systemwide++;
1263 }
1264 write_unlock(&filter->rwlock);
1265
1266 return done;
1267}
1268
1269static int uprobe_perf_close(struct trace_event_call *call,
1270 struct perf_event *event)
1271{
1272 struct trace_probe *tp;
1273 struct trace_uprobe *tu;
1274 int ret = 0;
1275
1276 tp = trace_probe_primary_from_call(call);
1277 if (WARN_ON_ONCE(!tp))
1278 return -ENODEV;
1279
1280 tu = container_of(tp, struct trace_uprobe, tp);
1281 if (trace_uprobe_filter_remove(tu->tp.event->filter, event))
1282 return 0;
1283
1284 list_for_each_entry(tu, trace_probe_probe_list(tp), tp.list) {
1285 ret = uprobe_apply(tu->inode, tu->offset, &tu->consumer, false);
1286 if (ret)
1287 break;
1288 }
1289
1290 return ret;
1291}
1292
1293static int uprobe_perf_open(struct trace_event_call *call,
1294 struct perf_event *event)
1295{
1296 struct trace_probe *tp;
1297 struct trace_uprobe *tu;
1298 int err = 0;
1299
1300 tp = trace_probe_primary_from_call(call);
1301 if (WARN_ON_ONCE(!tp))
1302 return -ENODEV;
1303
1304 tu = container_of(tp, struct trace_uprobe, tp);
1305 if (trace_uprobe_filter_add(tu->tp.event->filter, event))
1306 return 0;
1307
1308 list_for_each_entry(tu, trace_probe_probe_list(tp), tp.list) {
1309 err = uprobe_apply(tu->inode, tu->offset, &tu->consumer, true);
1310 if (err) {
1311 uprobe_perf_close(call, event);
1312 break;
1313 }
1314 }
1315
1316 return err;
1317}
1318
1319static bool uprobe_perf_filter(struct uprobe_consumer *uc,
1320 enum uprobe_filter_ctx ctx, struct mm_struct *mm)
1321{
1322 struct trace_uprobe_filter *filter;
1323 struct trace_uprobe *tu;
1324 int ret;
1325
1326 tu = container_of(uc, struct trace_uprobe, consumer);
1327 filter = tu->tp.event->filter;
1328
1329 read_lock(&filter->rwlock);
1330 ret = __uprobe_perf_filter(filter, mm);
1331 read_unlock(&filter->rwlock);
1332
1333 return ret;
1334}
1335
1336static void __uprobe_perf_func(struct trace_uprobe *tu,
1337 unsigned long func, struct pt_regs *regs,
1338 struct uprobe_cpu_buffer *ucb, int dsize)
1339{
1340 struct trace_event_call *call = trace_probe_event_call(&tu->tp);
1341 struct uprobe_trace_entry_head *entry;
1342 struct hlist_head *head;
1343 void *data;
1344 int size, esize;
1345 int rctx;
1346
1347#ifdef CONFIG_BPF_EVENTS
1348 if (bpf_prog_array_valid(call)) {
1349 u32 ret;
1350
1351 ret = bpf_prog_run_array_uprobe(call->prog_array, regs, bpf_prog_run);
1352 if (!ret)
1353 return;
1354 }
1355#endif /* CONFIG_BPF_EVENTS */
1356
1357 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
1358
1359 size = esize + tu->tp.size + dsize;
1360 size = ALIGN(size + sizeof(u32), sizeof(u64)) - sizeof(u32);
1361 if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, "profile buffer not large enough"))
1362 return;
1363
1364 preempt_disable();
1365 head = this_cpu_ptr(call->perf_events);
1366 if (hlist_empty(head))
1367 goto out;
1368
1369 entry = perf_trace_buf_alloc(size, NULL, &rctx);
1370 if (!entry)
1371 goto out;
1372
1373 if (is_ret_probe(tu)) {
1374 entry->vaddr[0] = func;
1375 entry->vaddr[1] = instruction_pointer(regs);
1376 data = DATAOF_TRACE_ENTRY(entry, true);
1377 } else {
1378 entry->vaddr[0] = instruction_pointer(regs);
1379 data = DATAOF_TRACE_ENTRY(entry, false);
1380 }
1381
1382 memcpy(data, ucb->buf, tu->tp.size + dsize);
1383
1384 if (size - esize > tu->tp.size + dsize) {
1385 int len = tu->tp.size + dsize;
1386
1387 memset(data + len, 0, size - esize - len);
1388 }
1389
1390 perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs,
1391 head, NULL);
1392 out:
1393 preempt_enable();
1394}
1395
1396/* uprobe profile handler */
1397static int uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs,
1398 struct uprobe_cpu_buffer *ucb, int dsize)
1399{
1400 if (!uprobe_perf_filter(&tu->consumer, 0, current->mm))
1401 return UPROBE_HANDLER_REMOVE;
1402
1403 if (!is_ret_probe(tu))
1404 __uprobe_perf_func(tu, 0, regs, ucb, dsize);
1405 return 0;
1406}
1407
1408static void uretprobe_perf_func(struct trace_uprobe *tu, unsigned long func,
1409 struct pt_regs *regs,
1410 struct uprobe_cpu_buffer *ucb, int dsize)
1411{
1412 __uprobe_perf_func(tu, func, regs, ucb, dsize);
1413}
1414
1415int bpf_get_uprobe_info(const struct perf_event *event, u32 *fd_type,
1416 const char **filename, u64 *probe_offset,
1417 u64 *probe_addr, bool perf_type_tracepoint)
1418{
1419 const char *pevent = trace_event_name(event->tp_event);
1420 const char *group = event->tp_event->class->system;
1421 struct trace_uprobe *tu;
1422
1423 if (perf_type_tracepoint)
1424 tu = find_probe_event(pevent, group);
1425 else
1426 tu = trace_uprobe_primary_from_call(event->tp_event);
1427 if (!tu)
1428 return -EINVAL;
1429
1430 *fd_type = is_ret_probe(tu) ? BPF_FD_TYPE_URETPROBE
1431 : BPF_FD_TYPE_UPROBE;
1432 *filename = tu->filename;
1433 *probe_offset = tu->offset;
1434 *probe_addr = 0;
1435 return 0;
1436}
1437#endif /* CONFIG_PERF_EVENTS */
1438
1439static int
1440trace_uprobe_register(struct trace_event_call *event, enum trace_reg type,
1441 void *data)
1442{
1443 struct trace_event_file *file = data;
1444
1445 switch (type) {
1446 case TRACE_REG_REGISTER:
1447 return probe_event_enable(event, file, NULL);
1448
1449 case TRACE_REG_UNREGISTER:
1450 probe_event_disable(event, file);
1451 return 0;
1452
1453#ifdef CONFIG_PERF_EVENTS
1454 case TRACE_REG_PERF_REGISTER:
1455 return probe_event_enable(event, NULL, uprobe_perf_filter);
1456
1457 case TRACE_REG_PERF_UNREGISTER:
1458 probe_event_disable(event, NULL);
1459 return 0;
1460
1461 case TRACE_REG_PERF_OPEN:
1462 return uprobe_perf_open(event, data);
1463
1464 case TRACE_REG_PERF_CLOSE:
1465 return uprobe_perf_close(event, data);
1466
1467#endif
1468 default:
1469 return 0;
1470 }
1471}
1472
1473static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs)
1474{
1475 struct trace_uprobe *tu;
1476 struct uprobe_dispatch_data udd;
1477 struct uprobe_cpu_buffer *ucb;
1478 int dsize, esize;
1479 int ret = 0;
1480
1481
1482 tu = container_of(con, struct trace_uprobe, consumer);
1483 tu->nhit++;
1484
1485 udd.tu = tu;
1486 udd.bp_addr = instruction_pointer(regs);
1487
1488 current->utask->vaddr = (unsigned long) &udd;
1489
1490 if (WARN_ON_ONCE(!uprobe_cpu_buffer))
1491 return 0;
1492
1493 dsize = __get_data_size(&tu->tp, regs);
1494 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
1495
1496 ucb = uprobe_buffer_get();
1497 store_trace_args(ucb->buf, &tu->tp, regs, esize, dsize);
1498
1499 if (trace_probe_test_flag(&tu->tp, TP_FLAG_TRACE))
1500 ret |= uprobe_trace_func(tu, regs, ucb, dsize);
1501
1502#ifdef CONFIG_PERF_EVENTS
1503 if (trace_probe_test_flag(&tu->tp, TP_FLAG_PROFILE))
1504 ret |= uprobe_perf_func(tu, regs, ucb, dsize);
1505#endif
1506 uprobe_buffer_put(ucb);
1507 return ret;
1508}
1509
1510static int uretprobe_dispatcher(struct uprobe_consumer *con,
1511 unsigned long func, struct pt_regs *regs)
1512{
1513 struct trace_uprobe *tu;
1514 struct uprobe_dispatch_data udd;
1515 struct uprobe_cpu_buffer *ucb;
1516 int dsize, esize;
1517
1518 tu = container_of(con, struct trace_uprobe, consumer);
1519
1520 udd.tu = tu;
1521 udd.bp_addr = func;
1522
1523 current->utask->vaddr = (unsigned long) &udd;
1524
1525 if (WARN_ON_ONCE(!uprobe_cpu_buffer))
1526 return 0;
1527
1528 dsize = __get_data_size(&tu->tp, regs);
1529 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
1530
1531 ucb = uprobe_buffer_get();
1532 store_trace_args(ucb->buf, &tu->tp, regs, esize, dsize);
1533
1534 if (trace_probe_test_flag(&tu->tp, TP_FLAG_TRACE))
1535 uretprobe_trace_func(tu, func, regs, ucb, dsize);
1536
1537#ifdef CONFIG_PERF_EVENTS
1538 if (trace_probe_test_flag(&tu->tp, TP_FLAG_PROFILE))
1539 uretprobe_perf_func(tu, func, regs, ucb, dsize);
1540#endif
1541 uprobe_buffer_put(ucb);
1542 return 0;
1543}
1544
1545static struct trace_event_functions uprobe_funcs = {
1546 .trace = print_uprobe_event
1547};
1548
1549static struct trace_event_fields uprobe_fields_array[] = {
1550 { .type = TRACE_FUNCTION_TYPE,
1551 .define_fields = uprobe_event_define_fields },
1552 {}
1553};
1554
1555static inline void init_trace_event_call(struct trace_uprobe *tu)
1556{
1557 struct trace_event_call *call = trace_probe_event_call(&tu->tp);
1558 call->event.funcs = &uprobe_funcs;
1559 call->class->fields_array = uprobe_fields_array;
1560
1561 call->flags = TRACE_EVENT_FL_UPROBE | TRACE_EVENT_FL_CAP_ANY;
1562 call->class->reg = trace_uprobe_register;
1563}
1564
1565static int register_uprobe_event(struct trace_uprobe *tu)
1566{
1567 init_trace_event_call(tu);
1568
1569 return trace_probe_register_event_call(&tu->tp);
1570}
1571
1572static int unregister_uprobe_event(struct trace_uprobe *tu)
1573{
1574 return trace_probe_unregister_event_call(&tu->tp);
1575}
1576
1577#ifdef CONFIG_PERF_EVENTS
1578struct trace_event_call *
1579create_local_trace_uprobe(char *name, unsigned long offs,
1580 unsigned long ref_ctr_offset, bool is_return)
1581{
1582 enum probe_print_type ptype;
1583 struct trace_uprobe *tu;
1584 struct path path;
1585 int ret;
1586
1587 ret = kern_path(name, LOOKUP_FOLLOW, &path);
1588 if (ret)
1589 return ERR_PTR(ret);
1590
1591 if (!d_is_reg(path.dentry)) {
1592 path_put(&path);
1593 return ERR_PTR(-EINVAL);
1594 }
1595
1596 /*
1597 * local trace_kprobes are not added to dyn_event, so they are never
1598 * searched in find_trace_kprobe(). Therefore, there is no concern of
1599 * duplicated name "DUMMY_EVENT" here.
1600 */
1601 tu = alloc_trace_uprobe(UPROBE_EVENT_SYSTEM, "DUMMY_EVENT", 0,
1602 is_return);
1603
1604 if (IS_ERR(tu)) {
1605 pr_info("Failed to allocate trace_uprobe.(%d)\n",
1606 (int)PTR_ERR(tu));
1607 path_put(&path);
1608 return ERR_CAST(tu);
1609 }
1610
1611 tu->offset = offs;
1612 tu->path = path;
1613 tu->ref_ctr_offset = ref_ctr_offset;
1614 tu->filename = kstrdup(name, GFP_KERNEL);
1615 if (!tu->filename) {
1616 ret = -ENOMEM;
1617 goto error;
1618 }
1619
1620 init_trace_event_call(tu);
1621
1622 ptype = is_ret_probe(tu) ? PROBE_PRINT_RETURN : PROBE_PRINT_NORMAL;
1623 if (traceprobe_set_print_fmt(&tu->tp, ptype) < 0) {
1624 ret = -ENOMEM;
1625 goto error;
1626 }
1627
1628 return trace_probe_event_call(&tu->tp);
1629error:
1630 free_trace_uprobe(tu);
1631 return ERR_PTR(ret);
1632}
1633
1634void destroy_local_trace_uprobe(struct trace_event_call *event_call)
1635{
1636 struct trace_uprobe *tu;
1637
1638 tu = trace_uprobe_primary_from_call(event_call);
1639
1640 free_trace_uprobe(tu);
1641}
1642#endif /* CONFIG_PERF_EVENTS */
1643
1644/* Make a trace interface for controlling probe points */
1645static __init int init_uprobe_trace(void)
1646{
1647 int ret;
1648
1649 ret = dyn_event_register(&trace_uprobe_ops);
1650 if (ret)
1651 return ret;
1652
1653 ret = tracing_init_dentry();
1654 if (ret)
1655 return 0;
1656
1657 trace_create_file("uprobe_events", TRACE_MODE_WRITE, NULL,
1658 NULL, &uprobe_events_ops);
1659 /* Profile interface */
1660 trace_create_file("uprobe_profile", TRACE_MODE_READ, NULL,
1661 NULL, &uprobe_profile_ops);
1662 return 0;
1663}
1664
1665fs_initcall(init_uprobe_trace);
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
28struct 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
40static int trace_uprobe_create(const char *raw_command);
41static int trace_uprobe_show(struct seq_file *m, struct dyn_event *ev);
42static int trace_uprobe_release(struct dyn_event *ev);
43static bool trace_uprobe_is_busy(struct dyn_event *ev);
44static bool trace_uprobe_match(const char *system, const char *event,
45 int argc, const char **argv, struct dyn_event *ev);
46
47static 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 */
58struct 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
70static bool is_trace_uprobe(struct dyn_event *ev)
71{
72 return ev->ops == &trace_uprobe_ops;
73}
74
75static 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
89static int register_uprobe_event(struct trace_uprobe *tu);
90static int unregister_uprobe_event(struct trace_uprobe *tu);
91
92static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs,
93 __u64 *data);
94static int uretprobe_dispatcher(struct uprobe_consumer *con,
95 unsigned long func, struct pt_regs *regs,
96 __u64 *data);
97
98#ifdef CONFIG_STACK_GROWSUP
99static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n)
100{
101 return addr - (n * sizeof(long));
102}
103#else
104static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n)
105{
106 return addr + (n * sizeof(long));
107}
108#endif
109
110static 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 */
126static nokprobe_inline int
127probe_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
134static nokprobe_inline int
135probe_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 */
144static nokprobe_inline int
145fetch_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
177static nokprobe_inline int
178fetch_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 */
184static nokprobe_inline int
185fetch_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
198static nokprobe_inline int
199fetch_store_strlen_user(unsigned long addr)
200{
201 return fetch_store_strlen(addr);
202}
203
204static 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 */
216static int
217process_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}
253NOKPROBE_SYMBOL(process_fetch_insn)
254
255static 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
262static inline bool uprobe_filter_is_empty(struct trace_uprobe_filter *filter)
263{
264 return !filter->nr_systemwide && list_empty(&filter->perf_events);
265}
266
267static inline bool is_ret_probe(struct trace_uprobe *tu)
268{
269 return tu->consumer.ret_handler != NULL;
270}
271
272static 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
279static 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
307static 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
318static nokprobe_inline struct trace_uprobe *
319trace_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 */
333static struct trace_uprobe *
334alloc_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
360error:
361 free_percpu(tu->nhits);
362 kfree(tu);
363
364 return ERR_PTR(ret);
365}
366
367static 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
379static 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 */
393static 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
408unreg:
409 dyn_event_remove(&tu->devent);
410 trace_probe_unlink(&tu->tp);
411 free_trace_uprobe(tu);
412 return 0;
413}
414
415static 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
444static 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 */
478static 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 */
496static 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
533end:
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 */
543static 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
718error:
719 free_trace_uprobe(tu);
720out:
721 trace_probe_log_clear();
722 return ret;
723
724fail_address_parse:
725 trace_probe_log_clear();
726 path_put(&path);
727 kfree(filename);
728
729 return ret;
730}
731
732int trace_uprobe_create(const char *raw_command)
733{
734 return trace_probe_create(raw_command, __trace_uprobe_create);
735}
736
737static 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
748static 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 */
756static 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
776static 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
786static 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
793static 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
810static 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
817static 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 */
827static 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
849static 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
856static 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
867static 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
875struct uprobe_cpu_buffer {
876 struct mutex mutex;
877 void *buf;
878 int dsize;
879};
880static struct uprobe_cpu_buffer __percpu *uprobe_cpu_buffer;
881static int uprobe_buffer_refcnt;
882#define MAX_UCB_BUFFER_SIZE PAGE_SIZE
883
884static 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
905err:
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
916static 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
931static 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
947static 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
964static void uprobe_buffer_put(struct uprobe_cpu_buffer *ucb)
965{
966 if (!ucb)
967 return;
968 mutex_unlock(&ucb->mutex);
969}
970
971static 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
998static 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 */
1035static 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
1054static 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 */
1070static enum print_line_t
1071print_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
1105typedef bool (*filter_func_t)(struct uprobe_consumer *self, struct mm_struct *mm);
1106
1107static 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
1121static 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
1141static 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
1201static 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
1226static 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
1249static 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
1262static inline bool
1263trace_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
1269static 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 */
1290static 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
1318static 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
1342static 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
1368static 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
1391static 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 const struct bpf_prog_array *array;
1406 u32 ret;
1407
1408 rcu_read_lock_trace();
1409 array = rcu_dereference_check(call->prog_array, rcu_read_lock_trace_held());
1410 ret = bpf_prog_run_array_uprobe(array, regs, bpf_prog_run);
1411 rcu_read_unlock_trace();
1412 if (!ret)
1413 return;
1414 }
1415#endif /* CONFIG_BPF_EVENTS */
1416
1417 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
1418
1419 ucb = prepare_uprobe_buffer(tu, regs, ucbp);
1420 size = esize + ucb->dsize;
1421 size = ALIGN(size + sizeof(u32), sizeof(u64)) - sizeof(u32);
1422 if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, "profile buffer not large enough"))
1423 return;
1424
1425 preempt_disable();
1426 head = this_cpu_ptr(call->perf_events);
1427 if (hlist_empty(head))
1428 goto out;
1429
1430 entry = perf_trace_buf_alloc(size, NULL, &rctx);
1431 if (!entry)
1432 goto out;
1433
1434 if (is_ret_probe(tu)) {
1435 entry->vaddr[0] = func;
1436 entry->vaddr[1] = instruction_pointer(regs);
1437 data = DATAOF_TRACE_ENTRY(entry, true);
1438 } else {
1439 entry->vaddr[0] = instruction_pointer(regs);
1440 data = DATAOF_TRACE_ENTRY(entry, false);
1441 }
1442
1443 memcpy(data, ucb->buf, ucb->dsize);
1444
1445 if (size - esize > ucb->dsize)
1446 memset(data + ucb->dsize, 0, size - esize - ucb->dsize);
1447
1448 perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs,
1449 head, NULL);
1450 out:
1451 preempt_enable();
1452}
1453
1454/* uprobe profile handler */
1455static int uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs,
1456 struct uprobe_cpu_buffer **ucbp)
1457{
1458 if (!uprobe_perf_filter(&tu->consumer, current->mm))
1459 return UPROBE_HANDLER_REMOVE;
1460
1461 if (!is_ret_probe(tu))
1462 __uprobe_perf_func(tu, 0, regs, ucbp);
1463 return 0;
1464}
1465
1466static void uretprobe_perf_func(struct trace_uprobe *tu, unsigned long func,
1467 struct pt_regs *regs,
1468 struct uprobe_cpu_buffer **ucbp)
1469{
1470 __uprobe_perf_func(tu, func, regs, ucbp);
1471}
1472
1473int bpf_get_uprobe_info(const struct perf_event *event, u32 *fd_type,
1474 const char **filename, u64 *probe_offset,
1475 u64 *probe_addr, bool perf_type_tracepoint)
1476{
1477 const char *pevent = trace_event_name(event->tp_event);
1478 const char *group = event->tp_event->class->system;
1479 struct trace_uprobe *tu;
1480
1481 if (perf_type_tracepoint)
1482 tu = find_probe_event(pevent, group);
1483 else
1484 tu = trace_uprobe_primary_from_call(event->tp_event);
1485 if (!tu)
1486 return -EINVAL;
1487
1488 *fd_type = is_ret_probe(tu) ? BPF_FD_TYPE_URETPROBE
1489 : BPF_FD_TYPE_UPROBE;
1490 *filename = tu->filename;
1491 *probe_offset = tu->offset;
1492 *probe_addr = 0;
1493 return 0;
1494}
1495#endif /* CONFIG_PERF_EVENTS */
1496
1497static int
1498trace_uprobe_register(struct trace_event_call *event, enum trace_reg type,
1499 void *data)
1500{
1501 struct trace_event_file *file = data;
1502
1503 switch (type) {
1504 case TRACE_REG_REGISTER:
1505 return probe_event_enable(event, file, NULL);
1506
1507 case TRACE_REG_UNREGISTER:
1508 probe_event_disable(event, file);
1509 return 0;
1510
1511#ifdef CONFIG_PERF_EVENTS
1512 case TRACE_REG_PERF_REGISTER:
1513 return probe_event_enable(event, NULL, uprobe_perf_filter);
1514
1515 case TRACE_REG_PERF_UNREGISTER:
1516 probe_event_disable(event, NULL);
1517 return 0;
1518
1519 case TRACE_REG_PERF_OPEN:
1520 return uprobe_perf_open(event, data);
1521
1522 case TRACE_REG_PERF_CLOSE:
1523 return uprobe_perf_close(event, data);
1524
1525#endif
1526 default:
1527 return 0;
1528 }
1529}
1530
1531static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs,
1532 __u64 *data)
1533{
1534 struct trace_uprobe *tu;
1535 struct uprobe_dispatch_data udd;
1536 struct uprobe_cpu_buffer *ucb = NULL;
1537 int ret = 0;
1538
1539 tu = container_of(con, struct trace_uprobe, consumer);
1540
1541 this_cpu_inc(*tu->nhits);
1542
1543 udd.tu = tu;
1544 udd.bp_addr = instruction_pointer(regs);
1545
1546 current->utask->vaddr = (unsigned long) &udd;
1547
1548 if (WARN_ON_ONCE(!uprobe_cpu_buffer))
1549 return 0;
1550
1551 if (trace_probe_test_flag(&tu->tp, TP_FLAG_TRACE))
1552 ret |= uprobe_trace_func(tu, regs, &ucb);
1553
1554#ifdef CONFIG_PERF_EVENTS
1555 if (trace_probe_test_flag(&tu->tp, TP_FLAG_PROFILE))
1556 ret |= uprobe_perf_func(tu, regs, &ucb);
1557#endif
1558 uprobe_buffer_put(ucb);
1559 return ret;
1560}
1561
1562static int uretprobe_dispatcher(struct uprobe_consumer *con,
1563 unsigned long func, struct pt_regs *regs,
1564 __u64 *data)
1565{
1566 struct trace_uprobe *tu;
1567 struct uprobe_dispatch_data udd;
1568 struct uprobe_cpu_buffer *ucb = NULL;
1569
1570 tu = container_of(con, struct trace_uprobe, consumer);
1571
1572 udd.tu = tu;
1573 udd.bp_addr = func;
1574
1575 current->utask->vaddr = (unsigned long) &udd;
1576
1577 if (WARN_ON_ONCE(!uprobe_cpu_buffer))
1578 return 0;
1579
1580 if (trace_probe_test_flag(&tu->tp, TP_FLAG_TRACE))
1581 uretprobe_trace_func(tu, func, regs, &ucb);
1582
1583#ifdef CONFIG_PERF_EVENTS
1584 if (trace_probe_test_flag(&tu->tp, TP_FLAG_PROFILE))
1585 uretprobe_perf_func(tu, func, regs, &ucb);
1586#endif
1587 uprobe_buffer_put(ucb);
1588 return 0;
1589}
1590
1591static struct trace_event_functions uprobe_funcs = {
1592 .trace = print_uprobe_event
1593};
1594
1595static struct trace_event_fields uprobe_fields_array[] = {
1596 { .type = TRACE_FUNCTION_TYPE,
1597 .define_fields = uprobe_event_define_fields },
1598 {}
1599};
1600
1601static inline void init_trace_event_call(struct trace_uprobe *tu)
1602{
1603 struct trace_event_call *call = trace_probe_event_call(&tu->tp);
1604 call->event.funcs = &uprobe_funcs;
1605 call->class->fields_array = uprobe_fields_array;
1606
1607 call->flags = TRACE_EVENT_FL_UPROBE | TRACE_EVENT_FL_CAP_ANY;
1608 call->class->reg = trace_uprobe_register;
1609}
1610
1611static int register_uprobe_event(struct trace_uprobe *tu)
1612{
1613 init_trace_event_call(tu);
1614
1615 return trace_probe_register_event_call(&tu->tp);
1616}
1617
1618static int unregister_uprobe_event(struct trace_uprobe *tu)
1619{
1620 return trace_probe_unregister_event_call(&tu->tp);
1621}
1622
1623#ifdef CONFIG_PERF_EVENTS
1624struct trace_event_call *
1625create_local_trace_uprobe(char *name, unsigned long offs,
1626 unsigned long ref_ctr_offset, bool is_return)
1627{
1628 enum probe_print_type ptype;
1629 struct trace_uprobe *tu;
1630 struct path path;
1631 int ret;
1632
1633 ret = kern_path(name, LOOKUP_FOLLOW, &path);
1634 if (ret)
1635 return ERR_PTR(ret);
1636
1637 if (!d_is_reg(path.dentry)) {
1638 path_put(&path);
1639 return ERR_PTR(-EINVAL);
1640 }
1641
1642 /*
1643 * local trace_kprobes are not added to dyn_event, so they are never
1644 * searched in find_trace_kprobe(). Therefore, there is no concern of
1645 * duplicated name "DUMMY_EVENT" here.
1646 */
1647 tu = alloc_trace_uprobe(UPROBE_EVENT_SYSTEM, "DUMMY_EVENT", 0,
1648 is_return);
1649
1650 if (IS_ERR(tu)) {
1651 pr_info("Failed to allocate trace_uprobe.(%d)\n",
1652 (int)PTR_ERR(tu));
1653 path_put(&path);
1654 return ERR_CAST(tu);
1655 }
1656
1657 tu->offset = offs;
1658 tu->path = path;
1659 tu->ref_ctr_offset = ref_ctr_offset;
1660 tu->filename = kstrdup(name, GFP_KERNEL);
1661 if (!tu->filename) {
1662 ret = -ENOMEM;
1663 goto error;
1664 }
1665
1666 init_trace_event_call(tu);
1667
1668 ptype = is_ret_probe(tu) ? PROBE_PRINT_RETURN : PROBE_PRINT_NORMAL;
1669 if (traceprobe_set_print_fmt(&tu->tp, ptype) < 0) {
1670 ret = -ENOMEM;
1671 goto error;
1672 }
1673
1674 return trace_probe_event_call(&tu->tp);
1675error:
1676 free_trace_uprobe(tu);
1677 return ERR_PTR(ret);
1678}
1679
1680void destroy_local_trace_uprobe(struct trace_event_call *event_call)
1681{
1682 struct trace_uprobe *tu;
1683
1684 tu = trace_uprobe_primary_from_call(event_call);
1685
1686 free_trace_uprobe(tu);
1687}
1688#endif /* CONFIG_PERF_EVENTS */
1689
1690/* Make a trace interface for controlling probe points */
1691static __init int init_uprobe_trace(void)
1692{
1693 int ret;
1694
1695 ret = dyn_event_register(&trace_uprobe_ops);
1696 if (ret)
1697 return ret;
1698
1699 ret = tracing_init_dentry();
1700 if (ret)
1701 return 0;
1702
1703 trace_create_file("uprobe_events", TRACE_MODE_WRITE, NULL,
1704 NULL, &uprobe_events_ops);
1705 /* Profile interface */
1706 trace_create_file("uprobe_profile", TRACE_MODE_READ, NULL,
1707 NULL, &uprobe_profile_ops);
1708 return 0;
1709}
1710
1711fs_initcall(init_uprobe_trace);