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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/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(int argc, const char **argv);
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 pr_warn("Failed to register probe event(%d)\n", ret);
518 goto end;
519 }
520
521 dyn_event_add(&tu->devent);
522
523end:
524 mutex_unlock(&event_mutex);
525
526 return ret;
527}
528
529/*
530 * Argument syntax:
531 * - Add uprobe: p|r[:[GRP/]EVENT] PATH:OFFSET [FETCHARGS]
532 */
533static int trace_uprobe_create(int argc, const char **argv)
534{
535 struct trace_uprobe *tu;
536 const char *event = NULL, *group = UPROBE_EVENT_SYSTEM;
537 char *arg, *filename, *rctr, *rctr_end, *tmp;
538 char buf[MAX_EVENT_NAME_LEN];
539 struct path path;
540 unsigned long offset, ref_ctr_offset;
541 bool is_return = false;
542 int i, ret;
543
544 ret = 0;
545 ref_ctr_offset = 0;
546
547 switch (argv[0][0]) {
548 case 'r':
549 is_return = true;
550 break;
551 case 'p':
552 break;
553 default:
554 return -ECANCELED;
555 }
556
557 if (argc < 2)
558 return -ECANCELED;
559
560 if (argv[0][1] == ':')
561 event = &argv[0][2];
562
563 if (!strchr(argv[1], '/'))
564 return -ECANCELED;
565
566 filename = kstrdup(argv[1], GFP_KERNEL);
567 if (!filename)
568 return -ENOMEM;
569
570 /* Find the last occurrence, in case the path contains ':' too. */
571 arg = strrchr(filename, ':');
572 if (!arg || !isdigit(arg[1])) {
573 kfree(filename);
574 return -ECANCELED;
575 }
576
577 trace_probe_log_init("trace_uprobe", argc, argv);
578 trace_probe_log_set_index(1); /* filename is the 2nd argument */
579
580 *arg++ = '\0';
581 ret = kern_path(filename, LOOKUP_FOLLOW, &path);
582 if (ret) {
583 trace_probe_log_err(0, FILE_NOT_FOUND);
584 kfree(filename);
585 trace_probe_log_clear();
586 return ret;
587 }
588 if (!d_is_reg(path.dentry)) {
589 trace_probe_log_err(0, NO_REGULAR_FILE);
590 ret = -EINVAL;
591 goto fail_address_parse;
592 }
593
594 /* Parse reference counter offset if specified. */
595 rctr = strchr(arg, '(');
596 if (rctr) {
597 rctr_end = strchr(rctr, ')');
598 if (!rctr_end) {
599 ret = -EINVAL;
600 rctr_end = rctr + strlen(rctr);
601 trace_probe_log_err(rctr_end - filename,
602 REFCNT_OPEN_BRACE);
603 goto fail_address_parse;
604 } else if (rctr_end[1] != '\0') {
605 ret = -EINVAL;
606 trace_probe_log_err(rctr_end + 1 - filename,
607 BAD_REFCNT_SUFFIX);
608 goto fail_address_parse;
609 }
610
611 *rctr++ = '\0';
612 *rctr_end = '\0';
613 ret = kstrtoul(rctr, 0, &ref_ctr_offset);
614 if (ret) {
615 trace_probe_log_err(rctr - filename, BAD_REFCNT);
616 goto fail_address_parse;
617 }
618 }
619
620 /* Parse uprobe offset. */
621 ret = kstrtoul(arg, 0, &offset);
622 if (ret) {
623 trace_probe_log_err(arg - filename, BAD_UPROBE_OFFS);
624 goto fail_address_parse;
625 }
626
627 /* setup a probe */
628 trace_probe_log_set_index(0);
629 if (event) {
630 ret = traceprobe_parse_event_name(&event, &group, buf,
631 event - argv[0]);
632 if (ret)
633 goto fail_address_parse;
634 } else {
635 char *tail;
636 char *ptr;
637
638 tail = kstrdup(kbasename(filename), GFP_KERNEL);
639 if (!tail) {
640 ret = -ENOMEM;
641 goto fail_address_parse;
642 }
643
644 ptr = strpbrk(tail, ".-_");
645 if (ptr)
646 *ptr = '\0';
647
648 snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_0x%lx", 'p', tail, offset);
649 event = buf;
650 kfree(tail);
651 }
652
653 argc -= 2;
654 argv += 2;
655
656 tu = alloc_trace_uprobe(group, event, argc, is_return);
657 if (IS_ERR(tu)) {
658 ret = PTR_ERR(tu);
659 /* This must return -ENOMEM otherwise there is a bug */
660 WARN_ON_ONCE(ret != -ENOMEM);
661 goto fail_address_parse;
662 }
663 tu->offset = offset;
664 tu->ref_ctr_offset = ref_ctr_offset;
665 tu->path = path;
666 tu->filename = filename;
667
668 /* parse arguments */
669 for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) {
670 tmp = kstrdup(argv[i], GFP_KERNEL);
671 if (!tmp) {
672 ret = -ENOMEM;
673 goto error;
674 }
675
676 trace_probe_log_set_index(i + 2);
677 ret = traceprobe_parse_probe_arg(&tu->tp, i, tmp,
678 is_return ? TPARG_FL_RETURN : 0);
679 kfree(tmp);
680 if (ret)
681 goto error;
682 }
683
684 ret = traceprobe_set_print_fmt(&tu->tp, is_ret_probe(tu));
685 if (ret < 0)
686 goto error;
687
688 ret = register_trace_uprobe(tu);
689 if (!ret)
690 goto out;
691
692error:
693 free_trace_uprobe(tu);
694out:
695 trace_probe_log_clear();
696 return ret;
697
698fail_address_parse:
699 trace_probe_log_clear();
700 path_put(&path);
701 kfree(filename);
702
703 return ret;
704}
705
706static int create_or_delete_trace_uprobe(int argc, char **argv)
707{
708 int ret;
709
710 if (argv[0][0] == '-')
711 return dyn_event_release(argc, argv, &trace_uprobe_ops);
712
713 ret = trace_uprobe_create(argc, (const char **)argv);
714 return ret == -ECANCELED ? -EINVAL : ret;
715}
716
717static int trace_uprobe_release(struct dyn_event *ev)
718{
719 struct trace_uprobe *tu = to_trace_uprobe(ev);
720
721 return unregister_trace_uprobe(tu);
722}
723
724/* Probes listing interfaces */
725static int trace_uprobe_show(struct seq_file *m, struct dyn_event *ev)
726{
727 struct trace_uprobe *tu = to_trace_uprobe(ev);
728 char c = is_ret_probe(tu) ? 'r' : 'p';
729 int i;
730
731 seq_printf(m, "%c:%s/%s %s:0x%0*lx", c, trace_probe_group_name(&tu->tp),
732 trace_probe_name(&tu->tp), tu->filename,
733 (int)(sizeof(void *) * 2), tu->offset);
734
735 if (tu->ref_ctr_offset)
736 seq_printf(m, "(0x%lx)", tu->ref_ctr_offset);
737
738 for (i = 0; i < tu->tp.nr_args; i++)
739 seq_printf(m, " %s=%s", tu->tp.args[i].name, tu->tp.args[i].comm);
740
741 seq_putc(m, '\n');
742 return 0;
743}
744
745static int probes_seq_show(struct seq_file *m, void *v)
746{
747 struct dyn_event *ev = v;
748
749 if (!is_trace_uprobe(ev))
750 return 0;
751
752 return trace_uprobe_show(m, ev);
753}
754
755static const struct seq_operations probes_seq_op = {
756 .start = dyn_event_seq_start,
757 .next = dyn_event_seq_next,
758 .stop = dyn_event_seq_stop,
759 .show = probes_seq_show
760};
761
762static int probes_open(struct inode *inode, struct file *file)
763{
764 int ret;
765
766 ret = security_locked_down(LOCKDOWN_TRACEFS);
767 if (ret)
768 return ret;
769
770 if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
771 ret = dyn_events_release_all(&trace_uprobe_ops);
772 if (ret)
773 return ret;
774 }
775
776 return seq_open(file, &probes_seq_op);
777}
778
779static ssize_t probes_write(struct file *file, const char __user *buffer,
780 size_t count, loff_t *ppos)
781{
782 return trace_parse_run_command(file, buffer, count, ppos,
783 create_or_delete_trace_uprobe);
784}
785
786static const struct file_operations uprobe_events_ops = {
787 .owner = THIS_MODULE,
788 .open = probes_open,
789 .read = seq_read,
790 .llseek = seq_lseek,
791 .release = seq_release,
792 .write = probes_write,
793};
794
795/* Probes profiling interfaces */
796static int probes_profile_seq_show(struct seq_file *m, void *v)
797{
798 struct dyn_event *ev = v;
799 struct trace_uprobe *tu;
800
801 if (!is_trace_uprobe(ev))
802 return 0;
803
804 tu = to_trace_uprobe(ev);
805 seq_printf(m, " %s %-44s %15lu\n", tu->filename,
806 trace_probe_name(&tu->tp), tu->nhit);
807 return 0;
808}
809
810static const struct seq_operations profile_seq_op = {
811 .start = dyn_event_seq_start,
812 .next = dyn_event_seq_next,
813 .stop = dyn_event_seq_stop,
814 .show = probes_profile_seq_show
815};
816
817static int profile_open(struct inode *inode, struct file *file)
818{
819 int ret;
820
821 ret = security_locked_down(LOCKDOWN_TRACEFS);
822 if (ret)
823 return ret;
824
825 return seq_open(file, &profile_seq_op);
826}
827
828static const struct file_operations uprobe_profile_ops = {
829 .owner = THIS_MODULE,
830 .open = profile_open,
831 .read = seq_read,
832 .llseek = seq_lseek,
833 .release = seq_release,
834};
835
836struct uprobe_cpu_buffer {
837 struct mutex mutex;
838 void *buf;
839};
840static struct uprobe_cpu_buffer __percpu *uprobe_cpu_buffer;
841static int uprobe_buffer_refcnt;
842
843static int uprobe_buffer_init(void)
844{
845 int cpu, err_cpu;
846
847 uprobe_cpu_buffer = alloc_percpu(struct uprobe_cpu_buffer);
848 if (uprobe_cpu_buffer == NULL)
849 return -ENOMEM;
850
851 for_each_possible_cpu(cpu) {
852 struct page *p = alloc_pages_node(cpu_to_node(cpu),
853 GFP_KERNEL, 0);
854 if (p == NULL) {
855 err_cpu = cpu;
856 goto err;
857 }
858 per_cpu_ptr(uprobe_cpu_buffer, cpu)->buf = page_address(p);
859 mutex_init(&per_cpu_ptr(uprobe_cpu_buffer, cpu)->mutex);
860 }
861
862 return 0;
863
864err:
865 for_each_possible_cpu(cpu) {
866 if (cpu == err_cpu)
867 break;
868 free_page((unsigned long)per_cpu_ptr(uprobe_cpu_buffer, cpu)->buf);
869 }
870
871 free_percpu(uprobe_cpu_buffer);
872 return -ENOMEM;
873}
874
875static int uprobe_buffer_enable(void)
876{
877 int ret = 0;
878
879 BUG_ON(!mutex_is_locked(&event_mutex));
880
881 if (uprobe_buffer_refcnt++ == 0) {
882 ret = uprobe_buffer_init();
883 if (ret < 0)
884 uprobe_buffer_refcnt--;
885 }
886
887 return ret;
888}
889
890static void uprobe_buffer_disable(void)
891{
892 int cpu;
893
894 BUG_ON(!mutex_is_locked(&event_mutex));
895
896 if (--uprobe_buffer_refcnt == 0) {
897 for_each_possible_cpu(cpu)
898 free_page((unsigned long)per_cpu_ptr(uprobe_cpu_buffer,
899 cpu)->buf);
900
901 free_percpu(uprobe_cpu_buffer);
902 uprobe_cpu_buffer = NULL;
903 }
904}
905
906static struct uprobe_cpu_buffer *uprobe_buffer_get(void)
907{
908 struct uprobe_cpu_buffer *ucb;
909 int cpu;
910
911 cpu = raw_smp_processor_id();
912 ucb = per_cpu_ptr(uprobe_cpu_buffer, cpu);
913
914 /*
915 * Use per-cpu buffers for fastest access, but we might migrate
916 * so the mutex makes sure we have sole access to it.
917 */
918 mutex_lock(&ucb->mutex);
919
920 return ucb;
921}
922
923static void uprobe_buffer_put(struct uprobe_cpu_buffer *ucb)
924{
925 mutex_unlock(&ucb->mutex);
926}
927
928static void __uprobe_trace_func(struct trace_uprobe *tu,
929 unsigned long func, struct pt_regs *regs,
930 struct uprobe_cpu_buffer *ucb, int dsize,
931 struct trace_event_file *trace_file)
932{
933 struct uprobe_trace_entry_head *entry;
934 struct trace_buffer *buffer;
935 struct ring_buffer_event *event;
936 void *data;
937 int size, esize;
938 struct trace_event_call *call = trace_probe_event_call(&tu->tp);
939
940 WARN_ON(call != trace_file->event_call);
941
942 if (WARN_ON_ONCE(tu->tp.size + dsize > PAGE_SIZE))
943 return;
944
945 if (trace_trigger_soft_disabled(trace_file))
946 return;
947
948 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
949 size = esize + tu->tp.size + dsize;
950 event = trace_event_buffer_lock_reserve(&buffer, trace_file,
951 call->event.type, size, 0, 0);
952 if (!event)
953 return;
954
955 entry = ring_buffer_event_data(event);
956 if (is_ret_probe(tu)) {
957 entry->vaddr[0] = func;
958 entry->vaddr[1] = instruction_pointer(regs);
959 data = DATAOF_TRACE_ENTRY(entry, true);
960 } else {
961 entry->vaddr[0] = instruction_pointer(regs);
962 data = DATAOF_TRACE_ENTRY(entry, false);
963 }
964
965 memcpy(data, ucb->buf, tu->tp.size + dsize);
966
967 event_trigger_unlock_commit(trace_file, buffer, event, entry, 0, 0);
968}
969
970/* uprobe handler */
971static int uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs,
972 struct uprobe_cpu_buffer *ucb, int dsize)
973{
974 struct event_file_link *link;
975
976 if (is_ret_probe(tu))
977 return 0;
978
979 rcu_read_lock();
980 trace_probe_for_each_link_rcu(link, &tu->tp)
981 __uprobe_trace_func(tu, 0, regs, ucb, dsize, link->file);
982 rcu_read_unlock();
983
984 return 0;
985}
986
987static void uretprobe_trace_func(struct trace_uprobe *tu, unsigned long func,
988 struct pt_regs *regs,
989 struct uprobe_cpu_buffer *ucb, int dsize)
990{
991 struct event_file_link *link;
992
993 rcu_read_lock();
994 trace_probe_for_each_link_rcu(link, &tu->tp)
995 __uprobe_trace_func(tu, func, regs, ucb, dsize, link->file);
996 rcu_read_unlock();
997}
998
999/* Event entry printers */
1000static enum print_line_t
1001print_uprobe_event(struct trace_iterator *iter, int flags, struct trace_event *event)
1002{
1003 struct uprobe_trace_entry_head *entry;
1004 struct trace_seq *s = &iter->seq;
1005 struct trace_uprobe *tu;
1006 u8 *data;
1007
1008 entry = (struct uprobe_trace_entry_head *)iter->ent;
1009 tu = trace_uprobe_primary_from_call(
1010 container_of(event, struct trace_event_call, event));
1011 if (unlikely(!tu))
1012 goto out;
1013
1014 if (is_ret_probe(tu)) {
1015 trace_seq_printf(s, "%s: (0x%lx <- 0x%lx)",
1016 trace_probe_name(&tu->tp),
1017 entry->vaddr[1], entry->vaddr[0]);
1018 data = DATAOF_TRACE_ENTRY(entry, true);
1019 } else {
1020 trace_seq_printf(s, "%s: (0x%lx)",
1021 trace_probe_name(&tu->tp),
1022 entry->vaddr[0]);
1023 data = DATAOF_TRACE_ENTRY(entry, false);
1024 }
1025
1026 if (print_probe_args(s, tu->tp.args, tu->tp.nr_args, data, entry) < 0)
1027 goto out;
1028
1029 trace_seq_putc(s, '\n');
1030
1031 out:
1032 return trace_handle_return(s);
1033}
1034
1035typedef bool (*filter_func_t)(struct uprobe_consumer *self,
1036 enum uprobe_filter_ctx ctx,
1037 struct mm_struct *mm);
1038
1039static int trace_uprobe_enable(struct trace_uprobe *tu, filter_func_t filter)
1040{
1041 int ret;
1042
1043 tu->consumer.filter = filter;
1044 tu->inode = d_real_inode(tu->path.dentry);
1045
1046 if (tu->ref_ctr_offset)
1047 ret = uprobe_register_refctr(tu->inode, tu->offset,
1048 tu->ref_ctr_offset, &tu->consumer);
1049 else
1050 ret = uprobe_register(tu->inode, tu->offset, &tu->consumer);
1051
1052 if (ret)
1053 tu->inode = NULL;
1054
1055 return ret;
1056}
1057
1058static void __probe_event_disable(struct trace_probe *tp)
1059{
1060 struct trace_probe *pos;
1061 struct trace_uprobe *tu;
1062
1063 tu = container_of(tp, struct trace_uprobe, tp);
1064 WARN_ON(!uprobe_filter_is_empty(tu->tp.event->filter));
1065
1066 list_for_each_entry(pos, trace_probe_probe_list(tp), list) {
1067 tu = container_of(pos, struct trace_uprobe, tp);
1068 if (!tu->inode)
1069 continue;
1070
1071 uprobe_unregister(tu->inode, tu->offset, &tu->consumer);
1072 tu->inode = NULL;
1073 }
1074}
1075
1076static int probe_event_enable(struct trace_event_call *call,
1077 struct trace_event_file *file, filter_func_t filter)
1078{
1079 struct trace_probe *pos, *tp;
1080 struct trace_uprobe *tu;
1081 bool enabled;
1082 int ret;
1083
1084 tp = trace_probe_primary_from_call(call);
1085 if (WARN_ON_ONCE(!tp))
1086 return -ENODEV;
1087 enabled = trace_probe_is_enabled(tp);
1088
1089 /* This may also change "enabled" state */
1090 if (file) {
1091 if (trace_probe_test_flag(tp, TP_FLAG_PROFILE))
1092 return -EINTR;
1093
1094 ret = trace_probe_add_file(tp, file);
1095 if (ret < 0)
1096 return ret;
1097 } else {
1098 if (trace_probe_test_flag(tp, TP_FLAG_TRACE))
1099 return -EINTR;
1100
1101 trace_probe_set_flag(tp, TP_FLAG_PROFILE);
1102 }
1103
1104 tu = container_of(tp, struct trace_uprobe, tp);
1105 WARN_ON(!uprobe_filter_is_empty(tu->tp.event->filter));
1106
1107 if (enabled)
1108 return 0;
1109
1110 ret = uprobe_buffer_enable();
1111 if (ret)
1112 goto err_flags;
1113
1114 list_for_each_entry(pos, trace_probe_probe_list(tp), list) {
1115 tu = container_of(pos, struct trace_uprobe, tp);
1116 ret = trace_uprobe_enable(tu, filter);
1117 if (ret) {
1118 __probe_event_disable(tp);
1119 goto err_buffer;
1120 }
1121 }
1122
1123 return 0;
1124
1125 err_buffer:
1126 uprobe_buffer_disable();
1127
1128 err_flags:
1129 if (file)
1130 trace_probe_remove_file(tp, file);
1131 else
1132 trace_probe_clear_flag(tp, TP_FLAG_PROFILE);
1133
1134 return ret;
1135}
1136
1137static void probe_event_disable(struct trace_event_call *call,
1138 struct trace_event_file *file)
1139{
1140 struct trace_probe *tp;
1141
1142 tp = trace_probe_primary_from_call(call);
1143 if (WARN_ON_ONCE(!tp))
1144 return;
1145
1146 if (!trace_probe_is_enabled(tp))
1147 return;
1148
1149 if (file) {
1150 if (trace_probe_remove_file(tp, file) < 0)
1151 return;
1152
1153 if (trace_probe_is_enabled(tp))
1154 return;
1155 } else
1156 trace_probe_clear_flag(tp, TP_FLAG_PROFILE);
1157
1158 __probe_event_disable(tp);
1159 uprobe_buffer_disable();
1160}
1161
1162static int uprobe_event_define_fields(struct trace_event_call *event_call)
1163{
1164 int ret, size;
1165 struct uprobe_trace_entry_head field;
1166 struct trace_uprobe *tu;
1167
1168 tu = trace_uprobe_primary_from_call(event_call);
1169 if (unlikely(!tu))
1170 return -ENODEV;
1171
1172 if (is_ret_probe(tu)) {
1173 DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_FUNC, 0);
1174 DEFINE_FIELD(unsigned long, vaddr[1], FIELD_STRING_RETIP, 0);
1175 size = SIZEOF_TRACE_ENTRY(true);
1176 } else {
1177 DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_IP, 0);
1178 size = SIZEOF_TRACE_ENTRY(false);
1179 }
1180
1181 return traceprobe_define_arg_fields(event_call, size, &tu->tp);
1182}
1183
1184#ifdef CONFIG_PERF_EVENTS
1185static bool
1186__uprobe_perf_filter(struct trace_uprobe_filter *filter, struct mm_struct *mm)
1187{
1188 struct perf_event *event;
1189
1190 if (filter->nr_systemwide)
1191 return true;
1192
1193 list_for_each_entry(event, &filter->perf_events, hw.tp_list) {
1194 if (event->hw.target->mm == mm)
1195 return true;
1196 }
1197
1198 return false;
1199}
1200
1201static inline bool
1202trace_uprobe_filter_event(struct trace_uprobe_filter *filter,
1203 struct perf_event *event)
1204{
1205 return __uprobe_perf_filter(filter, event->hw.target->mm);
1206}
1207
1208static bool trace_uprobe_filter_remove(struct trace_uprobe_filter *filter,
1209 struct perf_event *event)
1210{
1211 bool done;
1212
1213 write_lock(&filter->rwlock);
1214 if (event->hw.target) {
1215 list_del(&event->hw.tp_list);
1216 done = filter->nr_systemwide ||
1217 (event->hw.target->flags & PF_EXITING) ||
1218 trace_uprobe_filter_event(filter, event);
1219 } else {
1220 filter->nr_systemwide--;
1221 done = filter->nr_systemwide;
1222 }
1223 write_unlock(&filter->rwlock);
1224
1225 return done;
1226}
1227
1228/* This returns true if the filter always covers target mm */
1229static bool trace_uprobe_filter_add(struct trace_uprobe_filter *filter,
1230 struct perf_event *event)
1231{
1232 bool done;
1233
1234 write_lock(&filter->rwlock);
1235 if (event->hw.target) {
1236 /*
1237 * event->parent != NULL means copy_process(), we can avoid
1238 * uprobe_apply(). current->mm must be probed and we can rely
1239 * on dup_mmap() which preserves the already installed bp's.
1240 *
1241 * attr.enable_on_exec means that exec/mmap will install the
1242 * breakpoints we need.
1243 */
1244 done = filter->nr_systemwide ||
1245 event->parent || event->attr.enable_on_exec ||
1246 trace_uprobe_filter_event(filter, event);
1247 list_add(&event->hw.tp_list, &filter->perf_events);
1248 } else {
1249 done = filter->nr_systemwide;
1250 filter->nr_systemwide++;
1251 }
1252 write_unlock(&filter->rwlock);
1253
1254 return done;
1255}
1256
1257static int uprobe_perf_close(struct trace_event_call *call,
1258 struct perf_event *event)
1259{
1260 struct trace_probe *pos, *tp;
1261 struct trace_uprobe *tu;
1262 int ret = 0;
1263
1264 tp = trace_probe_primary_from_call(call);
1265 if (WARN_ON_ONCE(!tp))
1266 return -ENODEV;
1267
1268 tu = container_of(tp, struct trace_uprobe, tp);
1269 if (trace_uprobe_filter_remove(tu->tp.event->filter, event))
1270 return 0;
1271
1272 list_for_each_entry(pos, trace_probe_probe_list(tp), list) {
1273 tu = container_of(pos, struct trace_uprobe, tp);
1274 ret = uprobe_apply(tu->inode, tu->offset, &tu->consumer, false);
1275 if (ret)
1276 break;
1277 }
1278
1279 return ret;
1280}
1281
1282static int uprobe_perf_open(struct trace_event_call *call,
1283 struct perf_event *event)
1284{
1285 struct trace_probe *pos, *tp;
1286 struct trace_uprobe *tu;
1287 int err = 0;
1288
1289 tp = trace_probe_primary_from_call(call);
1290 if (WARN_ON_ONCE(!tp))
1291 return -ENODEV;
1292
1293 tu = container_of(tp, struct trace_uprobe, tp);
1294 if (trace_uprobe_filter_add(tu->tp.event->filter, event))
1295 return 0;
1296
1297 list_for_each_entry(pos, trace_probe_probe_list(tp), list) {
1298 err = uprobe_apply(tu->inode, tu->offset, &tu->consumer, true);
1299 if (err) {
1300 uprobe_perf_close(call, event);
1301 break;
1302 }
1303 }
1304
1305 return err;
1306}
1307
1308static bool uprobe_perf_filter(struct uprobe_consumer *uc,
1309 enum uprobe_filter_ctx ctx, struct mm_struct *mm)
1310{
1311 struct trace_uprobe_filter *filter;
1312 struct trace_uprobe *tu;
1313 int ret;
1314
1315 tu = container_of(uc, struct trace_uprobe, consumer);
1316 filter = tu->tp.event->filter;
1317
1318 read_lock(&filter->rwlock);
1319 ret = __uprobe_perf_filter(filter, mm);
1320 read_unlock(&filter->rwlock);
1321
1322 return ret;
1323}
1324
1325static void __uprobe_perf_func(struct trace_uprobe *tu,
1326 unsigned long func, struct pt_regs *regs,
1327 struct uprobe_cpu_buffer *ucb, int dsize)
1328{
1329 struct trace_event_call *call = trace_probe_event_call(&tu->tp);
1330 struct uprobe_trace_entry_head *entry;
1331 struct hlist_head *head;
1332 void *data;
1333 int size, esize;
1334 int rctx;
1335
1336 if (bpf_prog_array_valid(call)) {
1337 u32 ret;
1338
1339 preempt_disable();
1340 ret = trace_call_bpf(call, regs);
1341 preempt_enable();
1342 if (!ret)
1343 return;
1344 }
1345
1346 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
1347
1348 size = esize + tu->tp.size + dsize;
1349 size = ALIGN(size + sizeof(u32), sizeof(u64)) - sizeof(u32);
1350 if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, "profile buffer not large enough"))
1351 return;
1352
1353 preempt_disable();
1354 head = this_cpu_ptr(call->perf_events);
1355 if (hlist_empty(head))
1356 goto out;
1357
1358 entry = perf_trace_buf_alloc(size, NULL, &rctx);
1359 if (!entry)
1360 goto out;
1361
1362 if (is_ret_probe(tu)) {
1363 entry->vaddr[0] = func;
1364 entry->vaddr[1] = instruction_pointer(regs);
1365 data = DATAOF_TRACE_ENTRY(entry, true);
1366 } else {
1367 entry->vaddr[0] = instruction_pointer(regs);
1368 data = DATAOF_TRACE_ENTRY(entry, false);
1369 }
1370
1371 memcpy(data, ucb->buf, tu->tp.size + dsize);
1372
1373 if (size - esize > tu->tp.size + dsize) {
1374 int len = tu->tp.size + dsize;
1375
1376 memset(data + len, 0, size - esize - len);
1377 }
1378
1379 perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs,
1380 head, NULL);
1381 out:
1382 preempt_enable();
1383}
1384
1385/* uprobe profile handler */
1386static int uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs,
1387 struct uprobe_cpu_buffer *ucb, int dsize)
1388{
1389 if (!uprobe_perf_filter(&tu->consumer, 0, current->mm))
1390 return UPROBE_HANDLER_REMOVE;
1391
1392 if (!is_ret_probe(tu))
1393 __uprobe_perf_func(tu, 0, regs, ucb, dsize);
1394 return 0;
1395}
1396
1397static void uretprobe_perf_func(struct trace_uprobe *tu, unsigned long func,
1398 struct pt_regs *regs,
1399 struct uprobe_cpu_buffer *ucb, int dsize)
1400{
1401 __uprobe_perf_func(tu, func, regs, ucb, dsize);
1402}
1403
1404int bpf_get_uprobe_info(const struct perf_event *event, u32 *fd_type,
1405 const char **filename, u64 *probe_offset,
1406 bool perf_type_tracepoint)
1407{
1408 const char *pevent = trace_event_name(event->tp_event);
1409 const char *group = event->tp_event->class->system;
1410 struct trace_uprobe *tu;
1411
1412 if (perf_type_tracepoint)
1413 tu = find_probe_event(pevent, group);
1414 else
1415 tu = trace_uprobe_primary_from_call(event->tp_event);
1416 if (!tu)
1417 return -EINVAL;
1418
1419 *fd_type = is_ret_probe(tu) ? BPF_FD_TYPE_URETPROBE
1420 : BPF_FD_TYPE_UPROBE;
1421 *filename = tu->filename;
1422 *probe_offset = tu->offset;
1423 return 0;
1424}
1425#endif /* CONFIG_PERF_EVENTS */
1426
1427static int
1428trace_uprobe_register(struct trace_event_call *event, enum trace_reg type,
1429 void *data)
1430{
1431 struct trace_event_file *file = data;
1432
1433 switch (type) {
1434 case TRACE_REG_REGISTER:
1435 return probe_event_enable(event, file, NULL);
1436
1437 case TRACE_REG_UNREGISTER:
1438 probe_event_disable(event, file);
1439 return 0;
1440
1441#ifdef CONFIG_PERF_EVENTS
1442 case TRACE_REG_PERF_REGISTER:
1443 return probe_event_enable(event, NULL, uprobe_perf_filter);
1444
1445 case TRACE_REG_PERF_UNREGISTER:
1446 probe_event_disable(event, NULL);
1447 return 0;
1448
1449 case TRACE_REG_PERF_OPEN:
1450 return uprobe_perf_open(event, data);
1451
1452 case TRACE_REG_PERF_CLOSE:
1453 return uprobe_perf_close(event, data);
1454
1455#endif
1456 default:
1457 return 0;
1458 }
1459}
1460
1461static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs)
1462{
1463 struct trace_uprobe *tu;
1464 struct uprobe_dispatch_data udd;
1465 struct uprobe_cpu_buffer *ucb;
1466 int dsize, esize;
1467 int ret = 0;
1468
1469
1470 tu = container_of(con, struct trace_uprobe, consumer);
1471 tu->nhit++;
1472
1473 udd.tu = tu;
1474 udd.bp_addr = instruction_pointer(regs);
1475
1476 current->utask->vaddr = (unsigned long) &udd;
1477
1478 if (WARN_ON_ONCE(!uprobe_cpu_buffer))
1479 return 0;
1480
1481 dsize = __get_data_size(&tu->tp, regs);
1482 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
1483
1484 ucb = uprobe_buffer_get();
1485 store_trace_args(ucb->buf, &tu->tp, regs, esize, dsize);
1486
1487 if (trace_probe_test_flag(&tu->tp, TP_FLAG_TRACE))
1488 ret |= uprobe_trace_func(tu, regs, ucb, dsize);
1489
1490#ifdef CONFIG_PERF_EVENTS
1491 if (trace_probe_test_flag(&tu->tp, TP_FLAG_PROFILE))
1492 ret |= uprobe_perf_func(tu, regs, ucb, dsize);
1493#endif
1494 uprobe_buffer_put(ucb);
1495 return ret;
1496}
1497
1498static int uretprobe_dispatcher(struct uprobe_consumer *con,
1499 unsigned long func, struct pt_regs *regs)
1500{
1501 struct trace_uprobe *tu;
1502 struct uprobe_dispatch_data udd;
1503 struct uprobe_cpu_buffer *ucb;
1504 int dsize, esize;
1505
1506 tu = container_of(con, struct trace_uprobe, consumer);
1507
1508 udd.tu = tu;
1509 udd.bp_addr = func;
1510
1511 current->utask->vaddr = (unsigned long) &udd;
1512
1513 if (WARN_ON_ONCE(!uprobe_cpu_buffer))
1514 return 0;
1515
1516 dsize = __get_data_size(&tu->tp, regs);
1517 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
1518
1519 ucb = uprobe_buffer_get();
1520 store_trace_args(ucb->buf, &tu->tp, regs, esize, dsize);
1521
1522 if (trace_probe_test_flag(&tu->tp, TP_FLAG_TRACE))
1523 uretprobe_trace_func(tu, func, regs, ucb, dsize);
1524
1525#ifdef CONFIG_PERF_EVENTS
1526 if (trace_probe_test_flag(&tu->tp, TP_FLAG_PROFILE))
1527 uretprobe_perf_func(tu, func, regs, ucb, dsize);
1528#endif
1529 uprobe_buffer_put(ucb);
1530 return 0;
1531}
1532
1533static struct trace_event_functions uprobe_funcs = {
1534 .trace = print_uprobe_event
1535};
1536
1537static struct trace_event_fields uprobe_fields_array[] = {
1538 { .type = TRACE_FUNCTION_TYPE,
1539 .define_fields = uprobe_event_define_fields },
1540 {}
1541};
1542
1543static inline void init_trace_event_call(struct trace_uprobe *tu)
1544{
1545 struct trace_event_call *call = trace_probe_event_call(&tu->tp);
1546 call->event.funcs = &uprobe_funcs;
1547 call->class->fields_array = uprobe_fields_array;
1548
1549 call->flags = TRACE_EVENT_FL_UPROBE | TRACE_EVENT_FL_CAP_ANY;
1550 call->class->reg = trace_uprobe_register;
1551}
1552
1553static int register_uprobe_event(struct trace_uprobe *tu)
1554{
1555 init_trace_event_call(tu);
1556
1557 return trace_probe_register_event_call(&tu->tp);
1558}
1559
1560static int unregister_uprobe_event(struct trace_uprobe *tu)
1561{
1562 return trace_probe_unregister_event_call(&tu->tp);
1563}
1564
1565#ifdef CONFIG_PERF_EVENTS
1566struct trace_event_call *
1567create_local_trace_uprobe(char *name, unsigned long offs,
1568 unsigned long ref_ctr_offset, bool is_return)
1569{
1570 struct trace_uprobe *tu;
1571 struct path path;
1572 int ret;
1573
1574 ret = kern_path(name, LOOKUP_FOLLOW, &path);
1575 if (ret)
1576 return ERR_PTR(ret);
1577
1578 if (!d_is_reg(path.dentry)) {
1579 path_put(&path);
1580 return ERR_PTR(-EINVAL);
1581 }
1582
1583 /*
1584 * local trace_kprobes are not added to dyn_event, so they are never
1585 * searched in find_trace_kprobe(). Therefore, there is no concern of
1586 * duplicated name "DUMMY_EVENT" here.
1587 */
1588 tu = alloc_trace_uprobe(UPROBE_EVENT_SYSTEM, "DUMMY_EVENT", 0,
1589 is_return);
1590
1591 if (IS_ERR(tu)) {
1592 pr_info("Failed to allocate trace_uprobe.(%d)\n",
1593 (int)PTR_ERR(tu));
1594 path_put(&path);
1595 return ERR_CAST(tu);
1596 }
1597
1598 tu->offset = offs;
1599 tu->path = path;
1600 tu->ref_ctr_offset = ref_ctr_offset;
1601 tu->filename = kstrdup(name, GFP_KERNEL);
1602 init_trace_event_call(tu);
1603
1604 if (traceprobe_set_print_fmt(&tu->tp, is_ret_probe(tu)) < 0) {
1605 ret = -ENOMEM;
1606 goto error;
1607 }
1608
1609 return trace_probe_event_call(&tu->tp);
1610error:
1611 free_trace_uprobe(tu);
1612 return ERR_PTR(ret);
1613}
1614
1615void destroy_local_trace_uprobe(struct trace_event_call *event_call)
1616{
1617 struct trace_uprobe *tu;
1618
1619 tu = trace_uprobe_primary_from_call(event_call);
1620
1621 free_trace_uprobe(tu);
1622}
1623#endif /* CONFIG_PERF_EVENTS */
1624
1625/* Make a trace interface for controling probe points */
1626static __init int init_uprobe_trace(void)
1627{
1628 struct dentry *d_tracer;
1629 int ret;
1630
1631 ret = dyn_event_register(&trace_uprobe_ops);
1632 if (ret)
1633 return ret;
1634
1635 d_tracer = tracing_init_dentry();
1636 if (IS_ERR(d_tracer))
1637 return 0;
1638
1639 trace_create_file("uprobe_events", 0644, d_tracer,
1640 NULL, &uprobe_events_ops);
1641 /* Profile interface */
1642 trace_create_file("uprobe_profile", 0444, d_tracer,
1643 NULL, &uprobe_profile_ops);
1644 return 0;
1645}
1646
1647fs_initcall(init_uprobe_trace);