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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#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);
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * uprobes-based tracing events
4 *
5 * Copyright (C) IBM Corporation, 2010-2012
6 * Author: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
7 */
8#define pr_fmt(fmt) "trace_uprobe: " fmt
9
10#include <linux/security.h>
11#include <linux/ctype.h>
12#include <linux/module.h>
13#include <linux/uaccess.h>
14#include <linux/uprobes.h>
15#include <linux/namei.h>
16#include <linux/string.h>
17#include <linux/rculist.h>
18
19#include "trace_dynevent.h"
20#include "trace_probe.h"
21#include "trace_probe_tmpl.h"
22
23#define UPROBE_EVENT_SYSTEM "uprobes"
24
25struct uprobe_trace_entry_head {
26 struct trace_entry ent;
27 unsigned long vaddr[];
28};
29
30#define SIZEOF_TRACE_ENTRY(is_return) \
31 (sizeof(struct uprobe_trace_entry_head) + \
32 sizeof(unsigned long) * (is_return ? 2 : 1))
33
34#define DATAOF_TRACE_ENTRY(entry, is_return) \
35 ((void*)(entry) + SIZEOF_TRACE_ENTRY(is_return))
36
37static int trace_uprobe_create(const char *raw_command);
38static int trace_uprobe_show(struct seq_file *m, struct dyn_event *ev);
39static int trace_uprobe_release(struct dyn_event *ev);
40static bool trace_uprobe_is_busy(struct dyn_event *ev);
41static bool trace_uprobe_match(const char *system, const char *event,
42 int argc, const char **argv, struct dyn_event *ev);
43
44static struct dyn_event_operations trace_uprobe_ops = {
45 .create = trace_uprobe_create,
46 .show = trace_uprobe_show,
47 .is_busy = trace_uprobe_is_busy,
48 .free = trace_uprobe_release,
49 .match = trace_uprobe_match,
50};
51
52/*
53 * uprobe event core functions
54 */
55struct trace_uprobe {
56 struct dyn_event devent;
57 struct uprobe_consumer consumer;
58 struct path path;
59 struct inode *inode;
60 char *filename;
61 unsigned long offset;
62 unsigned long ref_ctr_offset;
63 unsigned long nhit;
64 struct trace_probe tp;
65};
66
67static bool is_trace_uprobe(struct dyn_event *ev)
68{
69 return ev->ops == &trace_uprobe_ops;
70}
71
72static struct trace_uprobe *to_trace_uprobe(struct dyn_event *ev)
73{
74 return container_of(ev, struct trace_uprobe, devent);
75}
76
77/**
78 * for_each_trace_uprobe - iterate over the trace_uprobe list
79 * @pos: the struct trace_uprobe * for each entry
80 * @dpos: the struct dyn_event * to use as a loop cursor
81 */
82#define for_each_trace_uprobe(pos, dpos) \
83 for_each_dyn_event(dpos) \
84 if (is_trace_uprobe(dpos) && (pos = to_trace_uprobe(dpos)))
85
86#define SIZEOF_TRACE_UPROBE(n) \
87 (offsetof(struct trace_uprobe, tp.args) + \
88 (sizeof(struct probe_arg) * (n)))
89
90static int register_uprobe_event(struct trace_uprobe *tu);
91static int unregister_uprobe_event(struct trace_uprobe *tu);
92
93struct uprobe_dispatch_data {
94 struct trace_uprobe *tu;
95 unsigned long bp_addr;
96};
97
98static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs);
99static int uretprobe_dispatcher(struct uprobe_consumer *con,
100 unsigned long func, struct pt_regs *regs);
101
102#ifdef CONFIG_STACK_GROWSUP
103static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n)
104{
105 return addr - (n * sizeof(long));
106}
107#else
108static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n)
109{
110 return addr + (n * sizeof(long));
111}
112#endif
113
114static unsigned long get_user_stack_nth(struct pt_regs *regs, unsigned int n)
115{
116 unsigned long ret;
117 unsigned long addr = user_stack_pointer(regs);
118
119 addr = adjust_stack_addr(addr, n);
120
121 if (copy_from_user(&ret, (void __force __user *) addr, sizeof(ret)))
122 return 0;
123
124 return ret;
125}
126
127/*
128 * Uprobes-specific fetch functions
129 */
130static nokprobe_inline int
131probe_mem_read(void *dest, void *src, size_t size)
132{
133 void __user *vaddr = (void __force __user *)src;
134
135 return copy_from_user(dest, vaddr, size) ? -EFAULT : 0;
136}
137
138static nokprobe_inline int
139probe_mem_read_user(void *dest, void *src, size_t size)
140{
141 return probe_mem_read(dest, src, size);
142}
143
144/*
145 * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max
146 * length and relative data location.
147 */
148static nokprobe_inline int
149fetch_store_string(unsigned long addr, void *dest, void *base)
150{
151 long ret;
152 u32 loc = *(u32 *)dest;
153 int maxlen = get_loc_len(loc);
154 u8 *dst = get_loc_data(dest, base);
155 void __user *src = (void __force __user *) addr;
156
157 if (unlikely(!maxlen))
158 return -ENOMEM;
159
160 if (addr == FETCH_TOKEN_COMM)
161 ret = strlcpy(dst, current->comm, maxlen);
162 else
163 ret = strncpy_from_user(dst, src, maxlen);
164 if (ret >= 0) {
165 if (ret == maxlen)
166 dst[ret - 1] = '\0';
167 else
168 /*
169 * Include the terminating null byte. In this case it
170 * was copied by strncpy_from_user but not accounted
171 * for in ret.
172 */
173 ret++;
174 *(u32 *)dest = make_data_loc(ret, (void *)dst - base);
175 }
176
177 return ret;
178}
179
180static nokprobe_inline int
181fetch_store_string_user(unsigned long addr, void *dest, void *base)
182{
183 return fetch_store_string(addr, dest, base);
184}
185
186/* Return the length of string -- including null terminal byte */
187static nokprobe_inline int
188fetch_store_strlen(unsigned long addr)
189{
190 int len;
191 void __user *vaddr = (void __force __user *) addr;
192
193 if (addr == FETCH_TOKEN_COMM)
194 len = strlen(current->comm) + 1;
195 else
196 len = strnlen_user(vaddr, MAX_STRING_SIZE);
197
198 return (len > MAX_STRING_SIZE) ? 0 : len;
199}
200
201static nokprobe_inline int
202fetch_store_strlen_user(unsigned long addr)
203{
204 return fetch_store_strlen(addr);
205}
206
207static unsigned long translate_user_vaddr(unsigned long file_offset)
208{
209 unsigned long base_addr;
210 struct uprobe_dispatch_data *udd;
211
212 udd = (void *) current->utask->vaddr;
213
214 base_addr = udd->bp_addr - udd->tu->offset;
215 return base_addr + file_offset;
216}
217
218/* Note that we don't verify it, since the code does not come from user space */
219static int
220process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs, void *dest,
221 void *base)
222{
223 unsigned long val;
224
225 /* 1st stage: get value from context */
226 switch (code->op) {
227 case FETCH_OP_REG:
228 val = regs_get_register(regs, code->param);
229 break;
230 case FETCH_OP_STACK:
231 val = get_user_stack_nth(regs, code->param);
232 break;
233 case FETCH_OP_STACKP:
234 val = user_stack_pointer(regs);
235 break;
236 case FETCH_OP_RETVAL:
237 val = regs_return_value(regs);
238 break;
239 case FETCH_OP_IMM:
240 val = code->immediate;
241 break;
242 case FETCH_OP_COMM:
243 val = FETCH_TOKEN_COMM;
244 break;
245 case FETCH_OP_DATA:
246 val = (unsigned long)code->data;
247 break;
248 case FETCH_OP_FOFFS:
249 val = translate_user_vaddr(code->immediate);
250 break;
251 default:
252 return -EILSEQ;
253 }
254 code++;
255
256 return process_fetch_insn_bottom(code, val, dest, base);
257}
258NOKPROBE_SYMBOL(process_fetch_insn)
259
260static inline void init_trace_uprobe_filter(struct trace_uprobe_filter *filter)
261{
262 rwlock_init(&filter->rwlock);
263 filter->nr_systemwide = 0;
264 INIT_LIST_HEAD(&filter->perf_events);
265}
266
267static inline bool uprobe_filter_is_empty(struct trace_uprobe_filter *filter)
268{
269 return !filter->nr_systemwide && list_empty(&filter->perf_events);
270}
271
272static inline bool is_ret_probe(struct trace_uprobe *tu)
273{
274 return tu->consumer.ret_handler != NULL;
275}
276
277static bool trace_uprobe_is_busy(struct dyn_event *ev)
278{
279 struct trace_uprobe *tu = to_trace_uprobe(ev);
280
281 return trace_probe_is_enabled(&tu->tp);
282}
283
284static bool trace_uprobe_match_command_head(struct trace_uprobe *tu,
285 int argc, const char **argv)
286{
287 char buf[MAX_ARGSTR_LEN + 1];
288 int len;
289
290 if (!argc)
291 return true;
292
293 len = strlen(tu->filename);
294 if (strncmp(tu->filename, argv[0], len) || argv[0][len] != ':')
295 return false;
296
297 if (tu->ref_ctr_offset == 0)
298 snprintf(buf, sizeof(buf), "0x%0*lx",
299 (int)(sizeof(void *) * 2), tu->offset);
300 else
301 snprintf(buf, sizeof(buf), "0x%0*lx(0x%lx)",
302 (int)(sizeof(void *) * 2), tu->offset,
303 tu->ref_ctr_offset);
304 if (strcmp(buf, &argv[0][len + 1]))
305 return false;
306
307 argc--; argv++;
308
309 return trace_probe_match_command_args(&tu->tp, argc, argv);
310}
311
312static bool trace_uprobe_match(const char *system, const char *event,
313 int argc, const char **argv, struct dyn_event *ev)
314{
315 struct trace_uprobe *tu = to_trace_uprobe(ev);
316
317 return strcmp(trace_probe_name(&tu->tp), event) == 0 &&
318 (!system || strcmp(trace_probe_group_name(&tu->tp), system) == 0) &&
319 trace_uprobe_match_command_head(tu, argc, argv);
320}
321
322static nokprobe_inline struct trace_uprobe *
323trace_uprobe_primary_from_call(struct trace_event_call *call)
324{
325 struct trace_probe *tp;
326
327 tp = trace_probe_primary_from_call(call);
328 if (WARN_ON_ONCE(!tp))
329 return NULL;
330
331 return container_of(tp, struct trace_uprobe, tp);
332}
333
334/*
335 * Allocate new trace_uprobe and initialize it (including uprobes).
336 */
337static struct trace_uprobe *
338alloc_trace_uprobe(const char *group, const char *event, int nargs, bool is_ret)
339{
340 struct trace_uprobe *tu;
341 int ret;
342
343 tu = kzalloc(SIZEOF_TRACE_UPROBE(nargs), GFP_KERNEL);
344 if (!tu)
345 return ERR_PTR(-ENOMEM);
346
347 ret = trace_probe_init(&tu->tp, event, group, true);
348 if (ret < 0)
349 goto error;
350
351 dyn_event_init(&tu->devent, &trace_uprobe_ops);
352 tu->consumer.handler = uprobe_dispatcher;
353 if (is_ret)
354 tu->consumer.ret_handler = uretprobe_dispatcher;
355 init_trace_uprobe_filter(tu->tp.event->filter);
356 return tu;
357
358error:
359 kfree(tu);
360
361 return ERR_PTR(ret);
362}
363
364static void free_trace_uprobe(struct trace_uprobe *tu)
365{
366 if (!tu)
367 return;
368
369 path_put(&tu->path);
370 trace_probe_cleanup(&tu->tp);
371 kfree(tu->filename);
372 kfree(tu);
373}
374
375static struct trace_uprobe *find_probe_event(const char *event, const char *group)
376{
377 struct dyn_event *pos;
378 struct trace_uprobe *tu;
379
380 for_each_trace_uprobe(tu, pos)
381 if (strcmp(trace_probe_name(&tu->tp), event) == 0 &&
382 strcmp(trace_probe_group_name(&tu->tp), group) == 0)
383 return tu;
384
385 return NULL;
386}
387
388/* Unregister a trace_uprobe and probe_event */
389static int unregister_trace_uprobe(struct trace_uprobe *tu)
390{
391 int ret;
392
393 if (trace_probe_has_sibling(&tu->tp))
394 goto unreg;
395
396 ret = unregister_uprobe_event(tu);
397 if (ret)
398 return ret;
399
400unreg:
401 dyn_event_remove(&tu->devent);
402 trace_probe_unlink(&tu->tp);
403 free_trace_uprobe(tu);
404 return 0;
405}
406
407static bool trace_uprobe_has_same_uprobe(struct trace_uprobe *orig,
408 struct trace_uprobe *comp)
409{
410 struct trace_probe_event *tpe = orig->tp.event;
411 struct trace_probe *pos;
412 struct inode *comp_inode = d_real_inode(comp->path.dentry);
413 int i;
414
415 list_for_each_entry(pos, &tpe->probes, list) {
416 orig = container_of(pos, struct trace_uprobe, tp);
417 if (comp_inode != d_real_inode(orig->path.dentry) ||
418 comp->offset != orig->offset)
419 continue;
420
421 /*
422 * trace_probe_compare_arg_type() ensured that nr_args and
423 * each argument name and type are same. Let's compare comm.
424 */
425 for (i = 0; i < orig->tp.nr_args; i++) {
426 if (strcmp(orig->tp.args[i].comm,
427 comp->tp.args[i].comm))
428 break;
429 }
430
431 if (i == orig->tp.nr_args)
432 return true;
433 }
434
435 return false;
436}
437
438static int append_trace_uprobe(struct trace_uprobe *tu, struct trace_uprobe *to)
439{
440 int ret;
441
442 ret = trace_probe_compare_arg_type(&tu->tp, &to->tp);
443 if (ret) {
444 /* Note that argument starts index = 2 */
445 trace_probe_log_set_index(ret + 1);
446 trace_probe_log_err(0, DIFF_ARG_TYPE);
447 return -EEXIST;
448 }
449 if (trace_uprobe_has_same_uprobe(to, tu)) {
450 trace_probe_log_set_index(0);
451 trace_probe_log_err(0, SAME_PROBE);
452 return -EEXIST;
453 }
454
455 /* Append to existing event */
456 ret = trace_probe_append(&tu->tp, &to->tp);
457 if (!ret)
458 dyn_event_add(&tu->devent);
459
460 return ret;
461}
462
463/*
464 * Uprobe with multiple reference counter is not allowed. i.e.
465 * If inode and offset matches, reference counter offset *must*
466 * match as well. Though, there is one exception: If user is
467 * replacing old trace_uprobe with new one(same group/event),
468 * then we allow same uprobe with new reference counter as far
469 * as the new one does not conflict with any other existing
470 * ones.
471 */
472static int validate_ref_ctr_offset(struct trace_uprobe *new)
473{
474 struct dyn_event *pos;
475 struct trace_uprobe *tmp;
476 struct inode *new_inode = d_real_inode(new->path.dentry);
477
478 for_each_trace_uprobe(tmp, pos) {
479 if (new_inode == d_real_inode(tmp->path.dentry) &&
480 new->offset == tmp->offset &&
481 new->ref_ctr_offset != tmp->ref_ctr_offset) {
482 pr_warn("Reference counter offset mismatch.");
483 return -EINVAL;
484 }
485 }
486 return 0;
487}
488
489/* Register a trace_uprobe and probe_event */
490static int register_trace_uprobe(struct trace_uprobe *tu)
491{
492 struct trace_uprobe *old_tu;
493 int ret;
494
495 mutex_lock(&event_mutex);
496
497 ret = validate_ref_ctr_offset(tu);
498 if (ret)
499 goto end;
500
501 /* register as an event */
502 old_tu = find_probe_event(trace_probe_name(&tu->tp),
503 trace_probe_group_name(&tu->tp));
504 if (old_tu) {
505 if (is_ret_probe(tu) != is_ret_probe(old_tu)) {
506 trace_probe_log_set_index(0);
507 trace_probe_log_err(0, DIFF_PROBE_TYPE);
508 ret = -EEXIST;
509 } else {
510 ret = append_trace_uprobe(tu, old_tu);
511 }
512 goto end;
513 }
514
515 ret = register_uprobe_event(tu);
516 if (ret) {
517 if (ret == -EEXIST) {
518 trace_probe_log_set_index(0);
519 trace_probe_log_err(0, EVENT_EXIST);
520 } else
521 pr_warn("Failed to register probe event(%d)\n", ret);
522 goto end;
523 }
524
525 dyn_event_add(&tu->devent);
526
527end:
528 mutex_unlock(&event_mutex);
529
530 return ret;
531}
532
533/*
534 * Argument syntax:
535 * - Add uprobe: p|r[:[GRP/]EVENT] PATH:OFFSET[%return][(REF)] [FETCHARGS]
536 */
537static int __trace_uprobe_create(int argc, const char **argv)
538{
539 struct trace_uprobe *tu;
540 const char *event = NULL, *group = UPROBE_EVENT_SYSTEM;
541 char *arg, *filename, *rctr, *rctr_end, *tmp;
542 char buf[MAX_EVENT_NAME_LEN];
543 struct path path;
544 unsigned long offset, ref_ctr_offset;
545 bool is_return = false;
546 int i, ret;
547
548 ret = 0;
549 ref_ctr_offset = 0;
550
551 switch (argv[0][0]) {
552 case 'r':
553 is_return = true;
554 break;
555 case 'p':
556 break;
557 default:
558 return -ECANCELED;
559 }
560
561 if (argc < 2)
562 return -ECANCELED;
563
564 if (argv[0][1] == ':')
565 event = &argv[0][2];
566
567 if (!strchr(argv[1], '/'))
568 return -ECANCELED;
569
570 filename = kstrdup(argv[1], GFP_KERNEL);
571 if (!filename)
572 return -ENOMEM;
573
574 /* Find the last occurrence, in case the path contains ':' too. */
575 arg = strrchr(filename, ':');
576 if (!arg || !isdigit(arg[1])) {
577 kfree(filename);
578 return -ECANCELED;
579 }
580
581 trace_probe_log_init("trace_uprobe", argc, argv);
582 trace_probe_log_set_index(1); /* filename is the 2nd argument */
583
584 *arg++ = '\0';
585 ret = kern_path(filename, LOOKUP_FOLLOW, &path);
586 if (ret) {
587 trace_probe_log_err(0, FILE_NOT_FOUND);
588 kfree(filename);
589 trace_probe_log_clear();
590 return ret;
591 }
592 if (!d_is_reg(path.dentry)) {
593 trace_probe_log_err(0, NO_REGULAR_FILE);
594 ret = -EINVAL;
595 goto fail_address_parse;
596 }
597
598 /* Parse reference counter offset if specified. */
599 rctr = strchr(arg, '(');
600 if (rctr) {
601 rctr_end = strchr(rctr, ')');
602 if (!rctr_end) {
603 ret = -EINVAL;
604 rctr_end = rctr + strlen(rctr);
605 trace_probe_log_err(rctr_end - filename,
606 REFCNT_OPEN_BRACE);
607 goto fail_address_parse;
608 } else if (rctr_end[1] != '\0') {
609 ret = -EINVAL;
610 trace_probe_log_err(rctr_end + 1 - filename,
611 BAD_REFCNT_SUFFIX);
612 goto fail_address_parse;
613 }
614
615 *rctr++ = '\0';
616 *rctr_end = '\0';
617 ret = kstrtoul(rctr, 0, &ref_ctr_offset);
618 if (ret) {
619 trace_probe_log_err(rctr - filename, BAD_REFCNT);
620 goto fail_address_parse;
621 }
622 }
623
624 /* Check if there is %return suffix */
625 tmp = strchr(arg, '%');
626 if (tmp) {
627 if (!strcmp(tmp, "%return")) {
628 *tmp = '\0';
629 is_return = true;
630 } else {
631 trace_probe_log_err(tmp - filename, BAD_ADDR_SUFFIX);
632 ret = -EINVAL;
633 goto fail_address_parse;
634 }
635 }
636
637 /* Parse uprobe offset. */
638 ret = kstrtoul(arg, 0, &offset);
639 if (ret) {
640 trace_probe_log_err(arg - filename, BAD_UPROBE_OFFS);
641 goto fail_address_parse;
642 }
643
644 /* setup a probe */
645 trace_probe_log_set_index(0);
646 if (event) {
647 ret = traceprobe_parse_event_name(&event, &group, buf,
648 event - argv[0]);
649 if (ret)
650 goto fail_address_parse;
651 } else {
652 char *tail;
653 char *ptr;
654
655 tail = kstrdup(kbasename(filename), GFP_KERNEL);
656 if (!tail) {
657 ret = -ENOMEM;
658 goto fail_address_parse;
659 }
660
661 ptr = strpbrk(tail, ".-_");
662 if (ptr)
663 *ptr = '\0';
664
665 snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_0x%lx", 'p', tail, offset);
666 event = buf;
667 kfree(tail);
668 }
669
670 argc -= 2;
671 argv += 2;
672
673 tu = alloc_trace_uprobe(group, event, argc, is_return);
674 if (IS_ERR(tu)) {
675 ret = PTR_ERR(tu);
676 /* This must return -ENOMEM otherwise there is a bug */
677 WARN_ON_ONCE(ret != -ENOMEM);
678 goto fail_address_parse;
679 }
680 tu->offset = offset;
681 tu->ref_ctr_offset = ref_ctr_offset;
682 tu->path = path;
683 tu->filename = filename;
684
685 /* parse arguments */
686 for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) {
687 tmp = kstrdup(argv[i], GFP_KERNEL);
688 if (!tmp) {
689 ret = -ENOMEM;
690 goto error;
691 }
692
693 trace_probe_log_set_index(i + 2);
694 ret = traceprobe_parse_probe_arg(&tu->tp, i, tmp,
695 is_return ? TPARG_FL_RETURN : 0);
696 kfree(tmp);
697 if (ret)
698 goto error;
699 }
700
701 ret = traceprobe_set_print_fmt(&tu->tp, is_ret_probe(tu));
702 if (ret < 0)
703 goto error;
704
705 ret = register_trace_uprobe(tu);
706 if (!ret)
707 goto out;
708
709error:
710 free_trace_uprobe(tu);
711out:
712 trace_probe_log_clear();
713 return ret;
714
715fail_address_parse:
716 trace_probe_log_clear();
717 path_put(&path);
718 kfree(filename);
719
720 return ret;
721}
722
723int trace_uprobe_create(const char *raw_command)
724{
725 return trace_probe_create(raw_command, __trace_uprobe_create);
726}
727
728static int create_or_delete_trace_uprobe(const char *raw_command)
729{
730 int ret;
731
732 if (raw_command[0] == '-')
733 return dyn_event_release(raw_command, &trace_uprobe_ops);
734
735 ret = trace_uprobe_create(raw_command);
736 return ret == -ECANCELED ? -EINVAL : ret;
737}
738
739static int trace_uprobe_release(struct dyn_event *ev)
740{
741 struct trace_uprobe *tu = to_trace_uprobe(ev);
742
743 return unregister_trace_uprobe(tu);
744}
745
746/* Probes listing interfaces */
747static int trace_uprobe_show(struct seq_file *m, struct dyn_event *ev)
748{
749 struct trace_uprobe *tu = to_trace_uprobe(ev);
750 char c = is_ret_probe(tu) ? 'r' : 'p';
751 int i;
752
753 seq_printf(m, "%c:%s/%s %s:0x%0*lx", c, trace_probe_group_name(&tu->tp),
754 trace_probe_name(&tu->tp), tu->filename,
755 (int)(sizeof(void *) * 2), tu->offset);
756
757 if (tu->ref_ctr_offset)
758 seq_printf(m, "(0x%lx)", tu->ref_ctr_offset);
759
760 for (i = 0; i < tu->tp.nr_args; i++)
761 seq_printf(m, " %s=%s", tu->tp.args[i].name, tu->tp.args[i].comm);
762
763 seq_putc(m, '\n');
764 return 0;
765}
766
767static int probes_seq_show(struct seq_file *m, void *v)
768{
769 struct dyn_event *ev = v;
770
771 if (!is_trace_uprobe(ev))
772 return 0;
773
774 return trace_uprobe_show(m, ev);
775}
776
777static const struct seq_operations probes_seq_op = {
778 .start = dyn_event_seq_start,
779 .next = dyn_event_seq_next,
780 .stop = dyn_event_seq_stop,
781 .show = probes_seq_show
782};
783
784static int probes_open(struct inode *inode, struct file *file)
785{
786 int ret;
787
788 ret = security_locked_down(LOCKDOWN_TRACEFS);
789 if (ret)
790 return ret;
791
792 if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
793 ret = dyn_events_release_all(&trace_uprobe_ops);
794 if (ret)
795 return ret;
796 }
797
798 return seq_open(file, &probes_seq_op);
799}
800
801static ssize_t probes_write(struct file *file, const char __user *buffer,
802 size_t count, loff_t *ppos)
803{
804 return trace_parse_run_command(file, buffer, count, ppos,
805 create_or_delete_trace_uprobe);
806}
807
808static const struct file_operations uprobe_events_ops = {
809 .owner = THIS_MODULE,
810 .open = probes_open,
811 .read = seq_read,
812 .llseek = seq_lseek,
813 .release = seq_release,
814 .write = probes_write,
815};
816
817/* Probes profiling interfaces */
818static int probes_profile_seq_show(struct seq_file *m, void *v)
819{
820 struct dyn_event *ev = v;
821 struct trace_uprobe *tu;
822
823 if (!is_trace_uprobe(ev))
824 return 0;
825
826 tu = to_trace_uprobe(ev);
827 seq_printf(m, " %s %-44s %15lu\n", tu->filename,
828 trace_probe_name(&tu->tp), tu->nhit);
829 return 0;
830}
831
832static const struct seq_operations profile_seq_op = {
833 .start = dyn_event_seq_start,
834 .next = dyn_event_seq_next,
835 .stop = dyn_event_seq_stop,
836 .show = probes_profile_seq_show
837};
838
839static int profile_open(struct inode *inode, struct file *file)
840{
841 int ret;
842
843 ret = security_locked_down(LOCKDOWN_TRACEFS);
844 if (ret)
845 return ret;
846
847 return seq_open(file, &profile_seq_op);
848}
849
850static const struct file_operations uprobe_profile_ops = {
851 .owner = THIS_MODULE,
852 .open = profile_open,
853 .read = seq_read,
854 .llseek = seq_lseek,
855 .release = seq_release,
856};
857
858struct uprobe_cpu_buffer {
859 struct mutex mutex;
860 void *buf;
861};
862static struct uprobe_cpu_buffer __percpu *uprobe_cpu_buffer;
863static int uprobe_buffer_refcnt;
864
865static int uprobe_buffer_init(void)
866{
867 int cpu, err_cpu;
868
869 uprobe_cpu_buffer = alloc_percpu(struct uprobe_cpu_buffer);
870 if (uprobe_cpu_buffer == NULL)
871 return -ENOMEM;
872
873 for_each_possible_cpu(cpu) {
874 struct page *p = alloc_pages_node(cpu_to_node(cpu),
875 GFP_KERNEL, 0);
876 if (p == NULL) {
877 err_cpu = cpu;
878 goto err;
879 }
880 per_cpu_ptr(uprobe_cpu_buffer, cpu)->buf = page_address(p);
881 mutex_init(&per_cpu_ptr(uprobe_cpu_buffer, cpu)->mutex);
882 }
883
884 return 0;
885
886err:
887 for_each_possible_cpu(cpu) {
888 if (cpu == err_cpu)
889 break;
890 free_page((unsigned long)per_cpu_ptr(uprobe_cpu_buffer, cpu)->buf);
891 }
892
893 free_percpu(uprobe_cpu_buffer);
894 return -ENOMEM;
895}
896
897static int uprobe_buffer_enable(void)
898{
899 int ret = 0;
900
901 BUG_ON(!mutex_is_locked(&event_mutex));
902
903 if (uprobe_buffer_refcnt++ == 0) {
904 ret = uprobe_buffer_init();
905 if (ret < 0)
906 uprobe_buffer_refcnt--;
907 }
908
909 return ret;
910}
911
912static void uprobe_buffer_disable(void)
913{
914 int cpu;
915
916 BUG_ON(!mutex_is_locked(&event_mutex));
917
918 if (--uprobe_buffer_refcnt == 0) {
919 for_each_possible_cpu(cpu)
920 free_page((unsigned long)per_cpu_ptr(uprobe_cpu_buffer,
921 cpu)->buf);
922
923 free_percpu(uprobe_cpu_buffer);
924 uprobe_cpu_buffer = NULL;
925 }
926}
927
928static struct uprobe_cpu_buffer *uprobe_buffer_get(void)
929{
930 struct uprobe_cpu_buffer *ucb;
931 int cpu;
932
933 cpu = raw_smp_processor_id();
934 ucb = per_cpu_ptr(uprobe_cpu_buffer, cpu);
935
936 /*
937 * Use per-cpu buffers for fastest access, but we might migrate
938 * so the mutex makes sure we have sole access to it.
939 */
940 mutex_lock(&ucb->mutex);
941
942 return ucb;
943}
944
945static void uprobe_buffer_put(struct uprobe_cpu_buffer *ucb)
946{
947 mutex_unlock(&ucb->mutex);
948}
949
950static void __uprobe_trace_func(struct trace_uprobe *tu,
951 unsigned long func, struct pt_regs *regs,
952 struct uprobe_cpu_buffer *ucb, int dsize,
953 struct trace_event_file *trace_file)
954{
955 struct uprobe_trace_entry_head *entry;
956 struct trace_buffer *buffer;
957 struct ring_buffer_event *event;
958 void *data;
959 int size, esize;
960 struct trace_event_call *call = trace_probe_event_call(&tu->tp);
961
962 WARN_ON(call != trace_file->event_call);
963
964 if (WARN_ON_ONCE(tu->tp.size + dsize > PAGE_SIZE))
965 return;
966
967 if (trace_trigger_soft_disabled(trace_file))
968 return;
969
970 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
971 size = esize + tu->tp.size + dsize;
972 event = trace_event_buffer_lock_reserve(&buffer, trace_file,
973 call->event.type, size, 0);
974 if (!event)
975 return;
976
977 entry = ring_buffer_event_data(event);
978 if (is_ret_probe(tu)) {
979 entry->vaddr[0] = func;
980 entry->vaddr[1] = instruction_pointer(regs);
981 data = DATAOF_TRACE_ENTRY(entry, true);
982 } else {
983 entry->vaddr[0] = instruction_pointer(regs);
984 data = DATAOF_TRACE_ENTRY(entry, false);
985 }
986
987 memcpy(data, ucb->buf, tu->tp.size + dsize);
988
989 event_trigger_unlock_commit(trace_file, buffer, event, entry, 0);
990}
991
992/* uprobe handler */
993static int uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs,
994 struct uprobe_cpu_buffer *ucb, int dsize)
995{
996 struct event_file_link *link;
997
998 if (is_ret_probe(tu))
999 return 0;
1000
1001 rcu_read_lock();
1002 trace_probe_for_each_link_rcu(link, &tu->tp)
1003 __uprobe_trace_func(tu, 0, regs, ucb, dsize, link->file);
1004 rcu_read_unlock();
1005
1006 return 0;
1007}
1008
1009static void uretprobe_trace_func(struct trace_uprobe *tu, unsigned long func,
1010 struct pt_regs *regs,
1011 struct uprobe_cpu_buffer *ucb, int dsize)
1012{
1013 struct event_file_link *link;
1014
1015 rcu_read_lock();
1016 trace_probe_for_each_link_rcu(link, &tu->tp)
1017 __uprobe_trace_func(tu, func, regs, ucb, dsize, link->file);
1018 rcu_read_unlock();
1019}
1020
1021/* Event entry printers */
1022static enum print_line_t
1023print_uprobe_event(struct trace_iterator *iter, int flags, struct trace_event *event)
1024{
1025 struct uprobe_trace_entry_head *entry;
1026 struct trace_seq *s = &iter->seq;
1027 struct trace_uprobe *tu;
1028 u8 *data;
1029
1030 entry = (struct uprobe_trace_entry_head *)iter->ent;
1031 tu = trace_uprobe_primary_from_call(
1032 container_of(event, struct trace_event_call, event));
1033 if (unlikely(!tu))
1034 goto out;
1035
1036 if (is_ret_probe(tu)) {
1037 trace_seq_printf(s, "%s: (0x%lx <- 0x%lx)",
1038 trace_probe_name(&tu->tp),
1039 entry->vaddr[1], entry->vaddr[0]);
1040 data = DATAOF_TRACE_ENTRY(entry, true);
1041 } else {
1042 trace_seq_printf(s, "%s: (0x%lx)",
1043 trace_probe_name(&tu->tp),
1044 entry->vaddr[0]);
1045 data = DATAOF_TRACE_ENTRY(entry, false);
1046 }
1047
1048 if (print_probe_args(s, tu->tp.args, tu->tp.nr_args, data, entry) < 0)
1049 goto out;
1050
1051 trace_seq_putc(s, '\n');
1052
1053 out:
1054 return trace_handle_return(s);
1055}
1056
1057typedef bool (*filter_func_t)(struct uprobe_consumer *self,
1058 enum uprobe_filter_ctx ctx,
1059 struct mm_struct *mm);
1060
1061static int trace_uprobe_enable(struct trace_uprobe *tu, filter_func_t filter)
1062{
1063 int ret;
1064
1065 tu->consumer.filter = filter;
1066 tu->inode = d_real_inode(tu->path.dentry);
1067
1068 if (tu->ref_ctr_offset)
1069 ret = uprobe_register_refctr(tu->inode, tu->offset,
1070 tu->ref_ctr_offset, &tu->consumer);
1071 else
1072 ret = uprobe_register(tu->inode, tu->offset, &tu->consumer);
1073
1074 if (ret)
1075 tu->inode = NULL;
1076
1077 return ret;
1078}
1079
1080static void __probe_event_disable(struct trace_probe *tp)
1081{
1082 struct trace_probe *pos;
1083 struct trace_uprobe *tu;
1084
1085 tu = container_of(tp, struct trace_uprobe, tp);
1086 WARN_ON(!uprobe_filter_is_empty(tu->tp.event->filter));
1087
1088 list_for_each_entry(pos, trace_probe_probe_list(tp), list) {
1089 tu = container_of(pos, struct trace_uprobe, tp);
1090 if (!tu->inode)
1091 continue;
1092
1093 uprobe_unregister(tu->inode, tu->offset, &tu->consumer);
1094 tu->inode = NULL;
1095 }
1096}
1097
1098static int probe_event_enable(struct trace_event_call *call,
1099 struct trace_event_file *file, filter_func_t filter)
1100{
1101 struct trace_probe *pos, *tp;
1102 struct trace_uprobe *tu;
1103 bool enabled;
1104 int ret;
1105
1106 tp = trace_probe_primary_from_call(call);
1107 if (WARN_ON_ONCE(!tp))
1108 return -ENODEV;
1109 enabled = trace_probe_is_enabled(tp);
1110
1111 /* This may also change "enabled" state */
1112 if (file) {
1113 if (trace_probe_test_flag(tp, TP_FLAG_PROFILE))
1114 return -EINTR;
1115
1116 ret = trace_probe_add_file(tp, file);
1117 if (ret < 0)
1118 return ret;
1119 } else {
1120 if (trace_probe_test_flag(tp, TP_FLAG_TRACE))
1121 return -EINTR;
1122
1123 trace_probe_set_flag(tp, TP_FLAG_PROFILE);
1124 }
1125
1126 tu = container_of(tp, struct trace_uprobe, tp);
1127 WARN_ON(!uprobe_filter_is_empty(tu->tp.event->filter));
1128
1129 if (enabled)
1130 return 0;
1131
1132 ret = uprobe_buffer_enable();
1133 if (ret)
1134 goto err_flags;
1135
1136 list_for_each_entry(pos, trace_probe_probe_list(tp), list) {
1137 tu = container_of(pos, struct trace_uprobe, tp);
1138 ret = trace_uprobe_enable(tu, filter);
1139 if (ret) {
1140 __probe_event_disable(tp);
1141 goto err_buffer;
1142 }
1143 }
1144
1145 return 0;
1146
1147 err_buffer:
1148 uprobe_buffer_disable();
1149
1150 err_flags:
1151 if (file)
1152 trace_probe_remove_file(tp, file);
1153 else
1154 trace_probe_clear_flag(tp, TP_FLAG_PROFILE);
1155
1156 return ret;
1157}
1158
1159static void probe_event_disable(struct trace_event_call *call,
1160 struct trace_event_file *file)
1161{
1162 struct trace_probe *tp;
1163
1164 tp = trace_probe_primary_from_call(call);
1165 if (WARN_ON_ONCE(!tp))
1166 return;
1167
1168 if (!trace_probe_is_enabled(tp))
1169 return;
1170
1171 if (file) {
1172 if (trace_probe_remove_file(tp, file) < 0)
1173 return;
1174
1175 if (trace_probe_is_enabled(tp))
1176 return;
1177 } else
1178 trace_probe_clear_flag(tp, TP_FLAG_PROFILE);
1179
1180 __probe_event_disable(tp);
1181 uprobe_buffer_disable();
1182}
1183
1184static int uprobe_event_define_fields(struct trace_event_call *event_call)
1185{
1186 int ret, size;
1187 struct uprobe_trace_entry_head field;
1188 struct trace_uprobe *tu;
1189
1190 tu = trace_uprobe_primary_from_call(event_call);
1191 if (unlikely(!tu))
1192 return -ENODEV;
1193
1194 if (is_ret_probe(tu)) {
1195 DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_FUNC, 0);
1196 DEFINE_FIELD(unsigned long, vaddr[1], FIELD_STRING_RETIP, 0);
1197 size = SIZEOF_TRACE_ENTRY(true);
1198 } else {
1199 DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_IP, 0);
1200 size = SIZEOF_TRACE_ENTRY(false);
1201 }
1202
1203 return traceprobe_define_arg_fields(event_call, size, &tu->tp);
1204}
1205
1206#ifdef CONFIG_PERF_EVENTS
1207static bool
1208__uprobe_perf_filter(struct trace_uprobe_filter *filter, struct mm_struct *mm)
1209{
1210 struct perf_event *event;
1211
1212 if (filter->nr_systemwide)
1213 return true;
1214
1215 list_for_each_entry(event, &filter->perf_events, hw.tp_list) {
1216 if (event->hw.target->mm == mm)
1217 return true;
1218 }
1219
1220 return false;
1221}
1222
1223static inline bool
1224trace_uprobe_filter_event(struct trace_uprobe_filter *filter,
1225 struct perf_event *event)
1226{
1227 return __uprobe_perf_filter(filter, event->hw.target->mm);
1228}
1229
1230static bool trace_uprobe_filter_remove(struct trace_uprobe_filter *filter,
1231 struct perf_event *event)
1232{
1233 bool done;
1234
1235 write_lock(&filter->rwlock);
1236 if (event->hw.target) {
1237 list_del(&event->hw.tp_list);
1238 done = filter->nr_systemwide ||
1239 (event->hw.target->flags & PF_EXITING) ||
1240 trace_uprobe_filter_event(filter, event);
1241 } else {
1242 filter->nr_systemwide--;
1243 done = filter->nr_systemwide;
1244 }
1245 write_unlock(&filter->rwlock);
1246
1247 return done;
1248}
1249
1250/* This returns true if the filter always covers target mm */
1251static bool trace_uprobe_filter_add(struct trace_uprobe_filter *filter,
1252 struct perf_event *event)
1253{
1254 bool done;
1255
1256 write_lock(&filter->rwlock);
1257 if (event->hw.target) {
1258 /*
1259 * event->parent != NULL means copy_process(), we can avoid
1260 * uprobe_apply(). current->mm must be probed and we can rely
1261 * on dup_mmap() which preserves the already installed bp's.
1262 *
1263 * attr.enable_on_exec means that exec/mmap will install the
1264 * breakpoints we need.
1265 */
1266 done = filter->nr_systemwide ||
1267 event->parent || event->attr.enable_on_exec ||
1268 trace_uprobe_filter_event(filter, event);
1269 list_add(&event->hw.tp_list, &filter->perf_events);
1270 } else {
1271 done = filter->nr_systemwide;
1272 filter->nr_systemwide++;
1273 }
1274 write_unlock(&filter->rwlock);
1275
1276 return done;
1277}
1278
1279static int uprobe_perf_close(struct trace_event_call *call,
1280 struct perf_event *event)
1281{
1282 struct trace_probe *pos, *tp;
1283 struct trace_uprobe *tu;
1284 int ret = 0;
1285
1286 tp = trace_probe_primary_from_call(call);
1287 if (WARN_ON_ONCE(!tp))
1288 return -ENODEV;
1289
1290 tu = container_of(tp, struct trace_uprobe, tp);
1291 if (trace_uprobe_filter_remove(tu->tp.event->filter, event))
1292 return 0;
1293
1294 list_for_each_entry(pos, trace_probe_probe_list(tp), list) {
1295 tu = container_of(pos, struct trace_uprobe, tp);
1296 ret = uprobe_apply(tu->inode, tu->offset, &tu->consumer, false);
1297 if (ret)
1298 break;
1299 }
1300
1301 return ret;
1302}
1303
1304static int uprobe_perf_open(struct trace_event_call *call,
1305 struct perf_event *event)
1306{
1307 struct trace_probe *pos, *tp;
1308 struct trace_uprobe *tu;
1309 int err = 0;
1310
1311 tp = trace_probe_primary_from_call(call);
1312 if (WARN_ON_ONCE(!tp))
1313 return -ENODEV;
1314
1315 tu = container_of(tp, struct trace_uprobe, tp);
1316 if (trace_uprobe_filter_add(tu->tp.event->filter, event))
1317 return 0;
1318
1319 list_for_each_entry(pos, trace_probe_probe_list(tp), list) {
1320 err = uprobe_apply(tu->inode, tu->offset, &tu->consumer, true);
1321 if (err) {
1322 uprobe_perf_close(call, event);
1323 break;
1324 }
1325 }
1326
1327 return err;
1328}
1329
1330static bool uprobe_perf_filter(struct uprobe_consumer *uc,
1331 enum uprobe_filter_ctx ctx, struct mm_struct *mm)
1332{
1333 struct trace_uprobe_filter *filter;
1334 struct trace_uprobe *tu;
1335 int ret;
1336
1337 tu = container_of(uc, struct trace_uprobe, consumer);
1338 filter = tu->tp.event->filter;
1339
1340 read_lock(&filter->rwlock);
1341 ret = __uprobe_perf_filter(filter, mm);
1342 read_unlock(&filter->rwlock);
1343
1344 return ret;
1345}
1346
1347static void __uprobe_perf_func(struct trace_uprobe *tu,
1348 unsigned long func, struct pt_regs *regs,
1349 struct uprobe_cpu_buffer *ucb, int dsize)
1350{
1351 struct trace_event_call *call = trace_probe_event_call(&tu->tp);
1352 struct uprobe_trace_entry_head *entry;
1353 struct hlist_head *head;
1354 void *data;
1355 int size, esize;
1356 int rctx;
1357
1358 if (bpf_prog_array_valid(call)) {
1359 u32 ret;
1360
1361 preempt_disable();
1362 ret = trace_call_bpf(call, regs);
1363 preempt_enable();
1364 if (!ret)
1365 return;
1366 }
1367
1368 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
1369
1370 size = esize + tu->tp.size + dsize;
1371 size = ALIGN(size + sizeof(u32), sizeof(u64)) - sizeof(u32);
1372 if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, "profile buffer not large enough"))
1373 return;
1374
1375 preempt_disable();
1376 head = this_cpu_ptr(call->perf_events);
1377 if (hlist_empty(head))
1378 goto out;
1379
1380 entry = perf_trace_buf_alloc(size, NULL, &rctx);
1381 if (!entry)
1382 goto out;
1383
1384 if (is_ret_probe(tu)) {
1385 entry->vaddr[0] = func;
1386 entry->vaddr[1] = instruction_pointer(regs);
1387 data = DATAOF_TRACE_ENTRY(entry, true);
1388 } else {
1389 entry->vaddr[0] = instruction_pointer(regs);
1390 data = DATAOF_TRACE_ENTRY(entry, false);
1391 }
1392
1393 memcpy(data, ucb->buf, tu->tp.size + dsize);
1394
1395 if (size - esize > tu->tp.size + dsize) {
1396 int len = tu->tp.size + dsize;
1397
1398 memset(data + len, 0, size - esize - len);
1399 }
1400
1401 perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs,
1402 head, NULL);
1403 out:
1404 preempt_enable();
1405}
1406
1407/* uprobe profile handler */
1408static int uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs,
1409 struct uprobe_cpu_buffer *ucb, int dsize)
1410{
1411 if (!uprobe_perf_filter(&tu->consumer, 0, current->mm))
1412 return UPROBE_HANDLER_REMOVE;
1413
1414 if (!is_ret_probe(tu))
1415 __uprobe_perf_func(tu, 0, regs, ucb, dsize);
1416 return 0;
1417}
1418
1419static void uretprobe_perf_func(struct trace_uprobe *tu, unsigned long func,
1420 struct pt_regs *regs,
1421 struct uprobe_cpu_buffer *ucb, int dsize)
1422{
1423 __uprobe_perf_func(tu, func, regs, ucb, dsize);
1424}
1425
1426int bpf_get_uprobe_info(const struct perf_event *event, u32 *fd_type,
1427 const char **filename, u64 *probe_offset,
1428 bool perf_type_tracepoint)
1429{
1430 const char *pevent = trace_event_name(event->tp_event);
1431 const char *group = event->tp_event->class->system;
1432 struct trace_uprobe *tu;
1433
1434 if (perf_type_tracepoint)
1435 tu = find_probe_event(pevent, group);
1436 else
1437 tu = trace_uprobe_primary_from_call(event->tp_event);
1438 if (!tu)
1439 return -EINVAL;
1440
1441 *fd_type = is_ret_probe(tu) ? BPF_FD_TYPE_URETPROBE
1442 : BPF_FD_TYPE_UPROBE;
1443 *filename = tu->filename;
1444 *probe_offset = tu->offset;
1445 return 0;
1446}
1447#endif /* CONFIG_PERF_EVENTS */
1448
1449static int
1450trace_uprobe_register(struct trace_event_call *event, enum trace_reg type,
1451 void *data)
1452{
1453 struct trace_event_file *file = data;
1454
1455 switch (type) {
1456 case TRACE_REG_REGISTER:
1457 return probe_event_enable(event, file, NULL);
1458
1459 case TRACE_REG_UNREGISTER:
1460 probe_event_disable(event, file);
1461 return 0;
1462
1463#ifdef CONFIG_PERF_EVENTS
1464 case TRACE_REG_PERF_REGISTER:
1465 return probe_event_enable(event, NULL, uprobe_perf_filter);
1466
1467 case TRACE_REG_PERF_UNREGISTER:
1468 probe_event_disable(event, NULL);
1469 return 0;
1470
1471 case TRACE_REG_PERF_OPEN:
1472 return uprobe_perf_open(event, data);
1473
1474 case TRACE_REG_PERF_CLOSE:
1475 return uprobe_perf_close(event, data);
1476
1477#endif
1478 default:
1479 return 0;
1480 }
1481}
1482
1483static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs)
1484{
1485 struct trace_uprobe *tu;
1486 struct uprobe_dispatch_data udd;
1487 struct uprobe_cpu_buffer *ucb;
1488 int dsize, esize;
1489 int ret = 0;
1490
1491
1492 tu = container_of(con, struct trace_uprobe, consumer);
1493 tu->nhit++;
1494
1495 udd.tu = tu;
1496 udd.bp_addr = instruction_pointer(regs);
1497
1498 current->utask->vaddr = (unsigned long) &udd;
1499
1500 if (WARN_ON_ONCE(!uprobe_cpu_buffer))
1501 return 0;
1502
1503 dsize = __get_data_size(&tu->tp, regs);
1504 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
1505
1506 ucb = uprobe_buffer_get();
1507 store_trace_args(ucb->buf, &tu->tp, regs, esize, dsize);
1508
1509 if (trace_probe_test_flag(&tu->tp, TP_FLAG_TRACE))
1510 ret |= uprobe_trace_func(tu, regs, ucb, dsize);
1511
1512#ifdef CONFIG_PERF_EVENTS
1513 if (trace_probe_test_flag(&tu->tp, TP_FLAG_PROFILE))
1514 ret |= uprobe_perf_func(tu, regs, ucb, dsize);
1515#endif
1516 uprobe_buffer_put(ucb);
1517 return ret;
1518}
1519
1520static int uretprobe_dispatcher(struct uprobe_consumer *con,
1521 unsigned long func, struct pt_regs *regs)
1522{
1523 struct trace_uprobe *tu;
1524 struct uprobe_dispatch_data udd;
1525 struct uprobe_cpu_buffer *ucb;
1526 int dsize, esize;
1527
1528 tu = container_of(con, struct trace_uprobe, consumer);
1529
1530 udd.tu = tu;
1531 udd.bp_addr = func;
1532
1533 current->utask->vaddr = (unsigned long) &udd;
1534
1535 if (WARN_ON_ONCE(!uprobe_cpu_buffer))
1536 return 0;
1537
1538 dsize = __get_data_size(&tu->tp, regs);
1539 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
1540
1541 ucb = uprobe_buffer_get();
1542 store_trace_args(ucb->buf, &tu->tp, regs, esize, dsize);
1543
1544 if (trace_probe_test_flag(&tu->tp, TP_FLAG_TRACE))
1545 uretprobe_trace_func(tu, func, regs, ucb, dsize);
1546
1547#ifdef CONFIG_PERF_EVENTS
1548 if (trace_probe_test_flag(&tu->tp, TP_FLAG_PROFILE))
1549 uretprobe_perf_func(tu, func, regs, ucb, dsize);
1550#endif
1551 uprobe_buffer_put(ucb);
1552 return 0;
1553}
1554
1555static struct trace_event_functions uprobe_funcs = {
1556 .trace = print_uprobe_event
1557};
1558
1559static struct trace_event_fields uprobe_fields_array[] = {
1560 { .type = TRACE_FUNCTION_TYPE,
1561 .define_fields = uprobe_event_define_fields },
1562 {}
1563};
1564
1565static inline void init_trace_event_call(struct trace_uprobe *tu)
1566{
1567 struct trace_event_call *call = trace_probe_event_call(&tu->tp);
1568 call->event.funcs = &uprobe_funcs;
1569 call->class->fields_array = uprobe_fields_array;
1570
1571 call->flags = TRACE_EVENT_FL_UPROBE | TRACE_EVENT_FL_CAP_ANY;
1572 call->class->reg = trace_uprobe_register;
1573}
1574
1575static int register_uprobe_event(struct trace_uprobe *tu)
1576{
1577 init_trace_event_call(tu);
1578
1579 return trace_probe_register_event_call(&tu->tp);
1580}
1581
1582static int unregister_uprobe_event(struct trace_uprobe *tu)
1583{
1584 return trace_probe_unregister_event_call(&tu->tp);
1585}
1586
1587#ifdef CONFIG_PERF_EVENTS
1588struct trace_event_call *
1589create_local_trace_uprobe(char *name, unsigned long offs,
1590 unsigned long ref_ctr_offset, bool is_return)
1591{
1592 struct trace_uprobe *tu;
1593 struct path path;
1594 int ret;
1595
1596 ret = kern_path(name, LOOKUP_FOLLOW, &path);
1597 if (ret)
1598 return ERR_PTR(ret);
1599
1600 if (!d_is_reg(path.dentry)) {
1601 path_put(&path);
1602 return ERR_PTR(-EINVAL);
1603 }
1604
1605 /*
1606 * local trace_kprobes are not added to dyn_event, so they are never
1607 * searched in find_trace_kprobe(). Therefore, there is no concern of
1608 * duplicated name "DUMMY_EVENT" here.
1609 */
1610 tu = alloc_trace_uprobe(UPROBE_EVENT_SYSTEM, "DUMMY_EVENT", 0,
1611 is_return);
1612
1613 if (IS_ERR(tu)) {
1614 pr_info("Failed to allocate trace_uprobe.(%d)\n",
1615 (int)PTR_ERR(tu));
1616 path_put(&path);
1617 return ERR_CAST(tu);
1618 }
1619
1620 tu->offset = offs;
1621 tu->path = path;
1622 tu->ref_ctr_offset = ref_ctr_offset;
1623 tu->filename = kstrdup(name, GFP_KERNEL);
1624 init_trace_event_call(tu);
1625
1626 if (traceprobe_set_print_fmt(&tu->tp, is_ret_probe(tu)) < 0) {
1627 ret = -ENOMEM;
1628 goto error;
1629 }
1630
1631 return trace_probe_event_call(&tu->tp);
1632error:
1633 free_trace_uprobe(tu);
1634 return ERR_PTR(ret);
1635}
1636
1637void destroy_local_trace_uprobe(struct trace_event_call *event_call)
1638{
1639 struct trace_uprobe *tu;
1640
1641 tu = trace_uprobe_primary_from_call(event_call);
1642
1643 free_trace_uprobe(tu);
1644}
1645#endif /* CONFIG_PERF_EVENTS */
1646
1647/* Make a trace interface for controlling probe points */
1648static __init int init_uprobe_trace(void)
1649{
1650 int ret;
1651
1652 ret = dyn_event_register(&trace_uprobe_ops);
1653 if (ret)
1654 return ret;
1655
1656 ret = tracing_init_dentry();
1657 if (ret)
1658 return 0;
1659
1660 trace_create_file("uprobe_events", 0644, NULL,
1661 NULL, &uprobe_events_ops);
1662 /* Profile interface */
1663 trace_create_file("uprobe_profile", 0444, NULL,
1664 NULL, &uprobe_profile_ops);
1665 return 0;
1666}
1667
1668fs_initcall(init_uprobe_trace);