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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
91struct uprobe_dispatch_data {
92 struct trace_uprobe *tu;
93 unsigned long bp_addr;
94};
95
96static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs);
97static int uretprobe_dispatcher(struct uprobe_consumer *con,
98 unsigned long func, struct pt_regs *regs);
99
100#ifdef CONFIG_STACK_GROWSUP
101static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n)
102{
103 return addr - (n * sizeof(long));
104}
105#else
106static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n)
107{
108 return addr + (n * sizeof(long));
109}
110#endif
111
112static unsigned long get_user_stack_nth(struct pt_regs *regs, unsigned int n)
113{
114 unsigned long ret;
115 unsigned long addr = user_stack_pointer(regs);
116
117 addr = adjust_stack_addr(addr, n);
118
119 if (copy_from_user(&ret, (void __force __user *) addr, sizeof(ret)))
120 return 0;
121
122 return ret;
123}
124
125/*
126 * Uprobes-specific fetch functions
127 */
128static nokprobe_inline int
129probe_mem_read(void *dest, void *src, size_t size)
130{
131 void __user *vaddr = (void __force __user *)src;
132
133 return copy_from_user(dest, vaddr, size) ? -EFAULT : 0;
134}
135
136static nokprobe_inline int
137probe_mem_read_user(void *dest, void *src, size_t size)
138{
139 return probe_mem_read(dest, src, size);
140}
141
142/*
143 * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max
144 * length and relative data location.
145 */
146static nokprobe_inline int
147fetch_store_string(unsigned long addr, void *dest, void *base)
148{
149 long ret;
150 u32 loc = *(u32 *)dest;
151 int maxlen = get_loc_len(loc);
152 u8 *dst = get_loc_data(dest, base);
153 void __user *src = (void __force __user *) addr;
154
155 if (unlikely(!maxlen))
156 return -ENOMEM;
157
158 if (addr == FETCH_TOKEN_COMM)
159 ret = strlcpy(dst, current->comm, maxlen);
160 else
161 ret = strncpy_from_user(dst, src, maxlen);
162 if (ret >= 0) {
163 if (ret == maxlen)
164 dst[ret - 1] = '\0';
165 else
166 /*
167 * Include the terminating null byte. In this case it
168 * was copied by strncpy_from_user but not accounted
169 * for in ret.
170 */
171 ret++;
172 *(u32 *)dest = make_data_loc(ret, (void *)dst - base);
173 }
174
175 return ret;
176}
177
178static nokprobe_inline int
179fetch_store_string_user(unsigned long addr, void *dest, void *base)
180{
181 return fetch_store_string(addr, dest, base);
182}
183
184/* Return the length of string -- including null terminal byte */
185static nokprobe_inline int
186fetch_store_strlen(unsigned long addr)
187{
188 int len;
189 void __user *vaddr = (void __force __user *) addr;
190
191 if (addr == FETCH_TOKEN_COMM)
192 len = strlen(current->comm) + 1;
193 else
194 len = strnlen_user(vaddr, MAX_STRING_SIZE);
195
196 return (len > MAX_STRING_SIZE) ? 0 : len;
197}
198
199static nokprobe_inline int
200fetch_store_strlen_user(unsigned long addr)
201{
202 return fetch_store_strlen(addr);
203}
204
205static unsigned long translate_user_vaddr(unsigned long file_offset)
206{
207 unsigned long base_addr;
208 struct uprobe_dispatch_data *udd;
209
210 udd = (void *) current->utask->vaddr;
211
212 base_addr = udd->bp_addr - udd->tu->offset;
213 return base_addr + file_offset;
214}
215
216/* Note that we don't verify it, since the code does not come from user space */
217static int
218process_fetch_insn(struct fetch_insn *code, void *rec, void *dest,
219 void *base)
220{
221 struct pt_regs *regs = rec;
222 unsigned long val;
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_IMM:
239 val = code->immediate;
240 break;
241 case FETCH_OP_COMM:
242 val = FETCH_TOKEN_COMM;
243 break;
244 case FETCH_OP_DATA:
245 val = (unsigned long)code->data;
246 break;
247 case FETCH_OP_FOFFS:
248 val = translate_user_vaddr(code->immediate);
249 break;
250 default:
251 return -EILSEQ;
252 }
253 code++;
254
255 return process_fetch_insn_bottom(code, val, dest, base);
256}
257NOKPROBE_SYMBOL(process_fetch_insn)
258
259static inline void init_trace_uprobe_filter(struct trace_uprobe_filter *filter)
260{
261 rwlock_init(&filter->rwlock);
262 filter->nr_systemwide = 0;
263 INIT_LIST_HEAD(&filter->perf_events);
264}
265
266static inline bool uprobe_filter_is_empty(struct trace_uprobe_filter *filter)
267{
268 return !filter->nr_systemwide && list_empty(&filter->perf_events);
269}
270
271static inline bool is_ret_probe(struct trace_uprobe *tu)
272{
273 return tu->consumer.ret_handler != NULL;
274}
275
276static bool trace_uprobe_is_busy(struct dyn_event *ev)
277{
278 struct trace_uprobe *tu = to_trace_uprobe(ev);
279
280 return trace_probe_is_enabled(&tu->tp);
281}
282
283static bool trace_uprobe_match_command_head(struct trace_uprobe *tu,
284 int argc, const char **argv)
285{
286 char buf[MAX_ARGSTR_LEN + 1];
287 int len;
288
289 if (!argc)
290 return true;
291
292 len = strlen(tu->filename);
293 if (strncmp(tu->filename, argv[0], len) || argv[0][len] != ':')
294 return false;
295
296 if (tu->ref_ctr_offset == 0)
297 snprintf(buf, sizeof(buf), "0x%0*lx",
298 (int)(sizeof(void *) * 2), tu->offset);
299 else
300 snprintf(buf, sizeof(buf), "0x%0*lx(0x%lx)",
301 (int)(sizeof(void *) * 2), tu->offset,
302 tu->ref_ctr_offset);
303 if (strcmp(buf, &argv[0][len + 1]))
304 return false;
305
306 argc--; argv++;
307
308 return trace_probe_match_command_args(&tu->tp, argc, argv);
309}
310
311static bool trace_uprobe_match(const char *system, const char *event,
312 int argc, const char **argv, struct dyn_event *ev)
313{
314 struct trace_uprobe *tu = to_trace_uprobe(ev);
315
316 return (event[0] == '\0' ||
317 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(struct_size(tu, tp.args, 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 /* If there's a reference to the dynamic event */
397 if (trace_event_dyn_busy(trace_probe_event_call(&tu->tp)))
398 return -EBUSY;
399
400 ret = unregister_uprobe_event(tu);
401 if (ret)
402 return ret;
403
404unreg:
405 dyn_event_remove(&tu->devent);
406 trace_probe_unlink(&tu->tp);
407 free_trace_uprobe(tu);
408 return 0;
409}
410
411static bool trace_uprobe_has_same_uprobe(struct trace_uprobe *orig,
412 struct trace_uprobe *comp)
413{
414 struct trace_probe_event *tpe = orig->tp.event;
415 struct inode *comp_inode = d_real_inode(comp->path.dentry);
416 int i;
417
418 list_for_each_entry(orig, &tpe->probes, tp.list) {
419 if (comp_inode != d_real_inode(orig->path.dentry) ||
420 comp->offset != orig->offset)
421 continue;
422
423 /*
424 * trace_probe_compare_arg_type() ensured that nr_args and
425 * each argument name and type are same. Let's compare comm.
426 */
427 for (i = 0; i < orig->tp.nr_args; i++) {
428 if (strcmp(orig->tp.args[i].comm,
429 comp->tp.args[i].comm))
430 break;
431 }
432
433 if (i == orig->tp.nr_args)
434 return true;
435 }
436
437 return false;
438}
439
440static int append_trace_uprobe(struct trace_uprobe *tu, struct trace_uprobe *to)
441{
442 int ret;
443
444 ret = trace_probe_compare_arg_type(&tu->tp, &to->tp);
445 if (ret) {
446 /* Note that argument starts index = 2 */
447 trace_probe_log_set_index(ret + 1);
448 trace_probe_log_err(0, DIFF_ARG_TYPE);
449 return -EEXIST;
450 }
451 if (trace_uprobe_has_same_uprobe(to, tu)) {
452 trace_probe_log_set_index(0);
453 trace_probe_log_err(0, SAME_PROBE);
454 return -EEXIST;
455 }
456
457 /* Append to existing event */
458 ret = trace_probe_append(&tu->tp, &to->tp);
459 if (!ret)
460 dyn_event_add(&tu->devent, trace_probe_event_call(&tu->tp));
461
462 return ret;
463}
464
465/*
466 * Uprobe with multiple reference counter is not allowed. i.e.
467 * If inode and offset matches, reference counter offset *must*
468 * match as well. Though, there is one exception: If user is
469 * replacing old trace_uprobe with new one(same group/event),
470 * then we allow same uprobe with new reference counter as far
471 * as the new one does not conflict with any other existing
472 * ones.
473 */
474static int validate_ref_ctr_offset(struct trace_uprobe *new)
475{
476 struct dyn_event *pos;
477 struct trace_uprobe *tmp;
478 struct inode *new_inode = d_real_inode(new->path.dentry);
479
480 for_each_trace_uprobe(tmp, pos) {
481 if (new_inode == d_real_inode(tmp->path.dentry) &&
482 new->offset == tmp->offset &&
483 new->ref_ctr_offset != tmp->ref_ctr_offset) {
484 pr_warn("Reference counter offset mismatch.");
485 return -EINVAL;
486 }
487 }
488 return 0;
489}
490
491/* Register a trace_uprobe and probe_event */
492static int register_trace_uprobe(struct trace_uprobe *tu)
493{
494 struct trace_uprobe *old_tu;
495 int ret;
496
497 mutex_lock(&event_mutex);
498
499 ret = validate_ref_ctr_offset(tu);
500 if (ret)
501 goto end;
502
503 /* register as an event */
504 old_tu = find_probe_event(trace_probe_name(&tu->tp),
505 trace_probe_group_name(&tu->tp));
506 if (old_tu) {
507 if (is_ret_probe(tu) != is_ret_probe(old_tu)) {
508 trace_probe_log_set_index(0);
509 trace_probe_log_err(0, DIFF_PROBE_TYPE);
510 ret = -EEXIST;
511 } else {
512 ret = append_trace_uprobe(tu, old_tu);
513 }
514 goto end;
515 }
516
517 ret = register_uprobe_event(tu);
518 if (ret) {
519 if (ret == -EEXIST) {
520 trace_probe_log_set_index(0);
521 trace_probe_log_err(0, EVENT_EXIST);
522 } else
523 pr_warn("Failed to register probe event(%d)\n", ret);
524 goto end;
525 }
526
527 dyn_event_add(&tu->devent, trace_probe_event_call(&tu->tp));
528
529end:
530 mutex_unlock(&event_mutex);
531
532 return ret;
533}
534
535/*
536 * Argument syntax:
537 * - Add uprobe: p|r[:[GRP/][EVENT]] PATH:OFFSET[%return][(REF)] [FETCHARGS]
538 */
539static int __trace_uprobe_create(int argc, const char **argv)
540{
541 struct trace_uprobe *tu;
542 const char *event = NULL, *group = UPROBE_EVENT_SYSTEM;
543 char *arg, *filename, *rctr, *rctr_end, *tmp;
544 char buf[MAX_EVENT_NAME_LEN];
545 char gbuf[MAX_EVENT_NAME_LEN];
546 enum probe_print_type ptype;
547 struct path path;
548 unsigned long offset, ref_ctr_offset;
549 bool is_return = false;
550 int i, ret;
551
552 ref_ctr_offset = 0;
553
554 switch (argv[0][0]) {
555 case 'r':
556 is_return = true;
557 break;
558 case 'p':
559 break;
560 default:
561 return -ECANCELED;
562 }
563
564 if (argc < 2)
565 return -ECANCELED;
566
567 if (argv[0][1] == ':')
568 event = &argv[0][2];
569
570 if (!strchr(argv[1], '/'))
571 return -ECANCELED;
572
573 filename = kstrdup(argv[1], GFP_KERNEL);
574 if (!filename)
575 return -ENOMEM;
576
577 /* Find the last occurrence, in case the path contains ':' too. */
578 arg = strrchr(filename, ':');
579 if (!arg || !isdigit(arg[1])) {
580 kfree(filename);
581 return -ECANCELED;
582 }
583
584 trace_probe_log_init("trace_uprobe", argc, argv);
585 trace_probe_log_set_index(1); /* filename is the 2nd argument */
586
587 *arg++ = '\0';
588 ret = kern_path(filename, LOOKUP_FOLLOW, &path);
589 if (ret) {
590 trace_probe_log_err(0, FILE_NOT_FOUND);
591 kfree(filename);
592 trace_probe_log_clear();
593 return ret;
594 }
595 if (!d_is_reg(path.dentry)) {
596 trace_probe_log_err(0, NO_REGULAR_FILE);
597 ret = -EINVAL;
598 goto fail_address_parse;
599 }
600
601 /* Parse reference counter offset if specified. */
602 rctr = strchr(arg, '(');
603 if (rctr) {
604 rctr_end = strchr(rctr, ')');
605 if (!rctr_end) {
606 ret = -EINVAL;
607 rctr_end = rctr + strlen(rctr);
608 trace_probe_log_err(rctr_end - filename,
609 REFCNT_OPEN_BRACE);
610 goto fail_address_parse;
611 } else if (rctr_end[1] != '\0') {
612 ret = -EINVAL;
613 trace_probe_log_err(rctr_end + 1 - filename,
614 BAD_REFCNT_SUFFIX);
615 goto fail_address_parse;
616 }
617
618 *rctr++ = '\0';
619 *rctr_end = '\0';
620 ret = kstrtoul(rctr, 0, &ref_ctr_offset);
621 if (ret) {
622 trace_probe_log_err(rctr - filename, BAD_REFCNT);
623 goto fail_address_parse;
624 }
625 }
626
627 /* Check if there is %return suffix */
628 tmp = strchr(arg, '%');
629 if (tmp) {
630 if (!strcmp(tmp, "%return")) {
631 *tmp = '\0';
632 is_return = true;
633 } else {
634 trace_probe_log_err(tmp - filename, BAD_ADDR_SUFFIX);
635 ret = -EINVAL;
636 goto fail_address_parse;
637 }
638 }
639
640 /* Parse uprobe offset. */
641 ret = kstrtoul(arg, 0, &offset);
642 if (ret) {
643 trace_probe_log_err(arg - filename, BAD_UPROBE_OFFS);
644 goto fail_address_parse;
645 }
646
647 /* setup a probe */
648 trace_probe_log_set_index(0);
649 if (event) {
650 ret = traceprobe_parse_event_name(&event, &group, gbuf,
651 event - argv[0]);
652 if (ret)
653 goto fail_address_parse;
654 }
655
656 if (!event) {
657 char *tail;
658 char *ptr;
659
660 tail = kstrdup(kbasename(filename), GFP_KERNEL);
661 if (!tail) {
662 ret = -ENOMEM;
663 goto fail_address_parse;
664 }
665
666 ptr = strpbrk(tail, ".-_");
667 if (ptr)
668 *ptr = '\0';
669
670 snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_0x%lx", 'p', tail, offset);
671 event = buf;
672 kfree(tail);
673 }
674
675 argc -= 2;
676 argv += 2;
677
678 tu = alloc_trace_uprobe(group, event, argc, is_return);
679 if (IS_ERR(tu)) {
680 ret = PTR_ERR(tu);
681 /* This must return -ENOMEM otherwise there is a bug */
682 WARN_ON_ONCE(ret != -ENOMEM);
683 goto fail_address_parse;
684 }
685 tu->offset = offset;
686 tu->ref_ctr_offset = ref_ctr_offset;
687 tu->path = path;
688 tu->filename = filename;
689
690 /* parse arguments */
691 for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) {
692 trace_probe_log_set_index(i + 2);
693 ret = traceprobe_parse_probe_arg(&tu->tp, i, argv[i],
694 (is_return ? TPARG_FL_RETURN : 0) |
695 TPARG_FL_USER);
696 if (ret)
697 goto error;
698 }
699
700 ptype = is_ret_probe(tu) ? PROBE_PRINT_RETURN : PROBE_PRINT_NORMAL;
701 ret = traceprobe_set_print_fmt(&tu->tp, ptype);
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_event_buffer fbuffer;
957 void *data;
958 int size, esize;
959 struct trace_event_call *call = trace_probe_event_call(&tu->tp);
960
961 WARN_ON(call != trace_file->event_call);
962
963 if (WARN_ON_ONCE(tu->tp.size + dsize > PAGE_SIZE))
964 return;
965
966 if (trace_trigger_soft_disabled(trace_file))
967 return;
968
969 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
970 size = esize + tu->tp.size + dsize;
971 entry = trace_event_buffer_reserve(&fbuffer, trace_file, size);
972 if (!entry)
973 return;
974
975 if (is_ret_probe(tu)) {
976 entry->vaddr[0] = func;
977 entry->vaddr[1] = instruction_pointer(regs);
978 data = DATAOF_TRACE_ENTRY(entry, true);
979 } else {
980 entry->vaddr[0] = instruction_pointer(regs);
981 data = DATAOF_TRACE_ENTRY(entry, false);
982 }
983
984 memcpy(data, ucb->buf, tu->tp.size + dsize);
985
986 trace_event_buffer_commit(&fbuffer);
987}
988
989/* uprobe handler */
990static int uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs,
991 struct uprobe_cpu_buffer *ucb, int dsize)
992{
993 struct event_file_link *link;
994
995 if (is_ret_probe(tu))
996 return 0;
997
998 rcu_read_lock();
999 trace_probe_for_each_link_rcu(link, &tu->tp)
1000 __uprobe_trace_func(tu, 0, regs, ucb, dsize, link->file);
1001 rcu_read_unlock();
1002
1003 return 0;
1004}
1005
1006static void uretprobe_trace_func(struct trace_uprobe *tu, unsigned long func,
1007 struct pt_regs *regs,
1008 struct uprobe_cpu_buffer *ucb, int dsize)
1009{
1010 struct event_file_link *link;
1011
1012 rcu_read_lock();
1013 trace_probe_for_each_link_rcu(link, &tu->tp)
1014 __uprobe_trace_func(tu, func, regs, ucb, dsize, link->file);
1015 rcu_read_unlock();
1016}
1017
1018/* Event entry printers */
1019static enum print_line_t
1020print_uprobe_event(struct trace_iterator *iter, int flags, struct trace_event *event)
1021{
1022 struct uprobe_trace_entry_head *entry;
1023 struct trace_seq *s = &iter->seq;
1024 struct trace_uprobe *tu;
1025 u8 *data;
1026
1027 entry = (struct uprobe_trace_entry_head *)iter->ent;
1028 tu = trace_uprobe_primary_from_call(
1029 container_of(event, struct trace_event_call, event));
1030 if (unlikely(!tu))
1031 goto out;
1032
1033 if (is_ret_probe(tu)) {
1034 trace_seq_printf(s, "%s: (0x%lx <- 0x%lx)",
1035 trace_probe_name(&tu->tp),
1036 entry->vaddr[1], entry->vaddr[0]);
1037 data = DATAOF_TRACE_ENTRY(entry, true);
1038 } else {
1039 trace_seq_printf(s, "%s: (0x%lx)",
1040 trace_probe_name(&tu->tp),
1041 entry->vaddr[0]);
1042 data = DATAOF_TRACE_ENTRY(entry, false);
1043 }
1044
1045 if (print_probe_args(s, tu->tp.args, tu->tp.nr_args, data, entry) < 0)
1046 goto out;
1047
1048 trace_seq_putc(s, '\n');
1049
1050 out:
1051 return trace_handle_return(s);
1052}
1053
1054typedef bool (*filter_func_t)(struct uprobe_consumer *self,
1055 enum uprobe_filter_ctx ctx,
1056 struct mm_struct *mm);
1057
1058static int trace_uprobe_enable(struct trace_uprobe *tu, filter_func_t filter)
1059{
1060 int ret;
1061
1062 tu->consumer.filter = filter;
1063 tu->inode = d_real_inode(tu->path.dentry);
1064
1065 if (tu->ref_ctr_offset)
1066 ret = uprobe_register_refctr(tu->inode, tu->offset,
1067 tu->ref_ctr_offset, &tu->consumer);
1068 else
1069 ret = uprobe_register(tu->inode, tu->offset, &tu->consumer);
1070
1071 if (ret)
1072 tu->inode = NULL;
1073
1074 return ret;
1075}
1076
1077static void __probe_event_disable(struct trace_probe *tp)
1078{
1079 struct trace_uprobe *tu;
1080
1081 tu = container_of(tp, struct trace_uprobe, tp);
1082 WARN_ON(!uprobe_filter_is_empty(tu->tp.event->filter));
1083
1084 list_for_each_entry(tu, trace_probe_probe_list(tp), tp.list) {
1085 if (!tu->inode)
1086 continue;
1087
1088 uprobe_unregister(tu->inode, tu->offset, &tu->consumer);
1089 tu->inode = NULL;
1090 }
1091}
1092
1093static int probe_event_enable(struct trace_event_call *call,
1094 struct trace_event_file *file, filter_func_t filter)
1095{
1096 struct trace_probe *tp;
1097 struct trace_uprobe *tu;
1098 bool enabled;
1099 int ret;
1100
1101 tp = trace_probe_primary_from_call(call);
1102 if (WARN_ON_ONCE(!tp))
1103 return -ENODEV;
1104 enabled = trace_probe_is_enabled(tp);
1105
1106 /* This may also change "enabled" state */
1107 if (file) {
1108 if (trace_probe_test_flag(tp, TP_FLAG_PROFILE))
1109 return -EINTR;
1110
1111 ret = trace_probe_add_file(tp, file);
1112 if (ret < 0)
1113 return ret;
1114 } else {
1115 if (trace_probe_test_flag(tp, TP_FLAG_TRACE))
1116 return -EINTR;
1117
1118 trace_probe_set_flag(tp, TP_FLAG_PROFILE);
1119 }
1120
1121 tu = container_of(tp, struct trace_uprobe, tp);
1122 WARN_ON(!uprobe_filter_is_empty(tu->tp.event->filter));
1123
1124 if (enabled)
1125 return 0;
1126
1127 ret = uprobe_buffer_enable();
1128 if (ret)
1129 goto err_flags;
1130
1131 list_for_each_entry(tu, trace_probe_probe_list(tp), tp.list) {
1132 ret = trace_uprobe_enable(tu, filter);
1133 if (ret) {
1134 __probe_event_disable(tp);
1135 goto err_buffer;
1136 }
1137 }
1138
1139 return 0;
1140
1141 err_buffer:
1142 uprobe_buffer_disable();
1143
1144 err_flags:
1145 if (file)
1146 trace_probe_remove_file(tp, file);
1147 else
1148 trace_probe_clear_flag(tp, TP_FLAG_PROFILE);
1149
1150 return ret;
1151}
1152
1153static void probe_event_disable(struct trace_event_call *call,
1154 struct trace_event_file *file)
1155{
1156 struct trace_probe *tp;
1157
1158 tp = trace_probe_primary_from_call(call);
1159 if (WARN_ON_ONCE(!tp))
1160 return;
1161
1162 if (!trace_probe_is_enabled(tp))
1163 return;
1164
1165 if (file) {
1166 if (trace_probe_remove_file(tp, file) < 0)
1167 return;
1168
1169 if (trace_probe_is_enabled(tp))
1170 return;
1171 } else
1172 trace_probe_clear_flag(tp, TP_FLAG_PROFILE);
1173
1174 __probe_event_disable(tp);
1175 uprobe_buffer_disable();
1176}
1177
1178static int uprobe_event_define_fields(struct trace_event_call *event_call)
1179{
1180 int ret, size;
1181 struct uprobe_trace_entry_head field;
1182 struct trace_uprobe *tu;
1183
1184 tu = trace_uprobe_primary_from_call(event_call);
1185 if (unlikely(!tu))
1186 return -ENODEV;
1187
1188 if (is_ret_probe(tu)) {
1189 DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_FUNC, 0);
1190 DEFINE_FIELD(unsigned long, vaddr[1], FIELD_STRING_RETIP, 0);
1191 size = SIZEOF_TRACE_ENTRY(true);
1192 } else {
1193 DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_IP, 0);
1194 size = SIZEOF_TRACE_ENTRY(false);
1195 }
1196
1197 return traceprobe_define_arg_fields(event_call, size, &tu->tp);
1198}
1199
1200#ifdef CONFIG_PERF_EVENTS
1201static bool
1202__uprobe_perf_filter(struct trace_uprobe_filter *filter, struct mm_struct *mm)
1203{
1204 struct perf_event *event;
1205
1206 if (filter->nr_systemwide)
1207 return true;
1208
1209 list_for_each_entry(event, &filter->perf_events, hw.tp_list) {
1210 if (event->hw.target->mm == mm)
1211 return true;
1212 }
1213
1214 return false;
1215}
1216
1217static inline bool
1218trace_uprobe_filter_event(struct trace_uprobe_filter *filter,
1219 struct perf_event *event)
1220{
1221 return __uprobe_perf_filter(filter, event->hw.target->mm);
1222}
1223
1224static bool trace_uprobe_filter_remove(struct trace_uprobe_filter *filter,
1225 struct perf_event *event)
1226{
1227 bool done;
1228
1229 write_lock(&filter->rwlock);
1230 if (event->hw.target) {
1231 list_del(&event->hw.tp_list);
1232 done = filter->nr_systemwide ||
1233 (event->hw.target->flags & PF_EXITING) ||
1234 trace_uprobe_filter_event(filter, event);
1235 } else {
1236 filter->nr_systemwide--;
1237 done = filter->nr_systemwide;
1238 }
1239 write_unlock(&filter->rwlock);
1240
1241 return done;
1242}
1243
1244/* This returns true if the filter always covers target mm */
1245static bool trace_uprobe_filter_add(struct trace_uprobe_filter *filter,
1246 struct perf_event *event)
1247{
1248 bool done;
1249
1250 write_lock(&filter->rwlock);
1251 if (event->hw.target) {
1252 /*
1253 * event->parent != NULL means copy_process(), we can avoid
1254 * uprobe_apply(). current->mm must be probed and we can rely
1255 * on dup_mmap() which preserves the already installed bp's.
1256 *
1257 * attr.enable_on_exec means that exec/mmap will install the
1258 * breakpoints we need.
1259 */
1260 done = filter->nr_systemwide ||
1261 event->parent || event->attr.enable_on_exec ||
1262 trace_uprobe_filter_event(filter, event);
1263 list_add(&event->hw.tp_list, &filter->perf_events);
1264 } else {
1265 done = filter->nr_systemwide;
1266 filter->nr_systemwide++;
1267 }
1268 write_unlock(&filter->rwlock);
1269
1270 return done;
1271}
1272
1273static int uprobe_perf_close(struct trace_event_call *call,
1274 struct perf_event *event)
1275{
1276 struct trace_probe *tp;
1277 struct trace_uprobe *tu;
1278 int ret = 0;
1279
1280 tp = trace_probe_primary_from_call(call);
1281 if (WARN_ON_ONCE(!tp))
1282 return -ENODEV;
1283
1284 tu = container_of(tp, struct trace_uprobe, tp);
1285 if (trace_uprobe_filter_remove(tu->tp.event->filter, event))
1286 return 0;
1287
1288 list_for_each_entry(tu, trace_probe_probe_list(tp), tp.list) {
1289 ret = uprobe_apply(tu->inode, tu->offset, &tu->consumer, false);
1290 if (ret)
1291 break;
1292 }
1293
1294 return ret;
1295}
1296
1297static int uprobe_perf_open(struct trace_event_call *call,
1298 struct perf_event *event)
1299{
1300 struct trace_probe *tp;
1301 struct trace_uprobe *tu;
1302 int err = 0;
1303
1304 tp = trace_probe_primary_from_call(call);
1305 if (WARN_ON_ONCE(!tp))
1306 return -ENODEV;
1307
1308 tu = container_of(tp, struct trace_uprobe, tp);
1309 if (trace_uprobe_filter_add(tu->tp.event->filter, event))
1310 return 0;
1311
1312 list_for_each_entry(tu, trace_probe_probe_list(tp), tp.list) {
1313 err = uprobe_apply(tu->inode, tu->offset, &tu->consumer, true);
1314 if (err) {
1315 uprobe_perf_close(call, event);
1316 break;
1317 }
1318 }
1319
1320 return err;
1321}
1322
1323static bool uprobe_perf_filter(struct uprobe_consumer *uc,
1324 enum uprobe_filter_ctx ctx, struct mm_struct *mm)
1325{
1326 struct trace_uprobe_filter *filter;
1327 struct trace_uprobe *tu;
1328 int ret;
1329
1330 tu = container_of(uc, struct trace_uprobe, consumer);
1331 filter = tu->tp.event->filter;
1332
1333 read_lock(&filter->rwlock);
1334 ret = __uprobe_perf_filter(filter, mm);
1335 read_unlock(&filter->rwlock);
1336
1337 return ret;
1338}
1339
1340static void __uprobe_perf_func(struct trace_uprobe *tu,
1341 unsigned long func, struct pt_regs *regs,
1342 struct uprobe_cpu_buffer *ucb, int dsize)
1343{
1344 struct trace_event_call *call = trace_probe_event_call(&tu->tp);
1345 struct uprobe_trace_entry_head *entry;
1346 struct hlist_head *head;
1347 void *data;
1348 int size, esize;
1349 int rctx;
1350
1351#ifdef CONFIG_BPF_EVENTS
1352 if (bpf_prog_array_valid(call)) {
1353 u32 ret;
1354
1355 ret = bpf_prog_run_array_sleepable(call->prog_array, regs, bpf_prog_run);
1356 if (!ret)
1357 return;
1358 }
1359#endif /* CONFIG_BPF_EVENTS */
1360
1361 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
1362
1363 size = esize + tu->tp.size + dsize;
1364 size = ALIGN(size + sizeof(u32), sizeof(u64)) - sizeof(u32);
1365 if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, "profile buffer not large enough"))
1366 return;
1367
1368 preempt_disable();
1369 head = this_cpu_ptr(call->perf_events);
1370 if (hlist_empty(head))
1371 goto out;
1372
1373 entry = perf_trace_buf_alloc(size, NULL, &rctx);
1374 if (!entry)
1375 goto out;
1376
1377 if (is_ret_probe(tu)) {
1378 entry->vaddr[0] = func;
1379 entry->vaddr[1] = instruction_pointer(regs);
1380 data = DATAOF_TRACE_ENTRY(entry, true);
1381 } else {
1382 entry->vaddr[0] = instruction_pointer(regs);
1383 data = DATAOF_TRACE_ENTRY(entry, false);
1384 }
1385
1386 memcpy(data, ucb->buf, tu->tp.size + dsize);
1387
1388 if (size - esize > tu->tp.size + dsize) {
1389 int len = tu->tp.size + dsize;
1390
1391 memset(data + len, 0, size - esize - len);
1392 }
1393
1394 perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs,
1395 head, NULL);
1396 out:
1397 preempt_enable();
1398}
1399
1400/* uprobe profile handler */
1401static int uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs,
1402 struct uprobe_cpu_buffer *ucb, int dsize)
1403{
1404 if (!uprobe_perf_filter(&tu->consumer, 0, current->mm))
1405 return UPROBE_HANDLER_REMOVE;
1406
1407 if (!is_ret_probe(tu))
1408 __uprobe_perf_func(tu, 0, regs, ucb, dsize);
1409 return 0;
1410}
1411
1412static void uretprobe_perf_func(struct trace_uprobe *tu, unsigned long func,
1413 struct pt_regs *regs,
1414 struct uprobe_cpu_buffer *ucb, int dsize)
1415{
1416 __uprobe_perf_func(tu, func, regs, ucb, dsize);
1417}
1418
1419int bpf_get_uprobe_info(const struct perf_event *event, u32 *fd_type,
1420 const char **filename, u64 *probe_offset,
1421 bool perf_type_tracepoint)
1422{
1423 const char *pevent = trace_event_name(event->tp_event);
1424 const char *group = event->tp_event->class->system;
1425 struct trace_uprobe *tu;
1426
1427 if (perf_type_tracepoint)
1428 tu = find_probe_event(pevent, group);
1429 else
1430 tu = trace_uprobe_primary_from_call(event->tp_event);
1431 if (!tu)
1432 return -EINVAL;
1433
1434 *fd_type = is_ret_probe(tu) ? BPF_FD_TYPE_URETPROBE
1435 : BPF_FD_TYPE_UPROBE;
1436 *filename = tu->filename;
1437 *probe_offset = tu->offset;
1438 return 0;
1439}
1440#endif /* CONFIG_PERF_EVENTS */
1441
1442static int
1443trace_uprobe_register(struct trace_event_call *event, enum trace_reg type,
1444 void *data)
1445{
1446 struct trace_event_file *file = data;
1447
1448 switch (type) {
1449 case TRACE_REG_REGISTER:
1450 return probe_event_enable(event, file, NULL);
1451
1452 case TRACE_REG_UNREGISTER:
1453 probe_event_disable(event, file);
1454 return 0;
1455
1456#ifdef CONFIG_PERF_EVENTS
1457 case TRACE_REG_PERF_REGISTER:
1458 return probe_event_enable(event, NULL, uprobe_perf_filter);
1459
1460 case TRACE_REG_PERF_UNREGISTER:
1461 probe_event_disable(event, NULL);
1462 return 0;
1463
1464 case TRACE_REG_PERF_OPEN:
1465 return uprobe_perf_open(event, data);
1466
1467 case TRACE_REG_PERF_CLOSE:
1468 return uprobe_perf_close(event, data);
1469
1470#endif
1471 default:
1472 return 0;
1473 }
1474}
1475
1476static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs)
1477{
1478 struct trace_uprobe *tu;
1479 struct uprobe_dispatch_data udd;
1480 struct uprobe_cpu_buffer *ucb;
1481 int dsize, esize;
1482 int ret = 0;
1483
1484
1485 tu = container_of(con, struct trace_uprobe, consumer);
1486 tu->nhit++;
1487
1488 udd.tu = tu;
1489 udd.bp_addr = instruction_pointer(regs);
1490
1491 current->utask->vaddr = (unsigned long) &udd;
1492
1493 if (WARN_ON_ONCE(!uprobe_cpu_buffer))
1494 return 0;
1495
1496 dsize = __get_data_size(&tu->tp, regs);
1497 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
1498
1499 ucb = uprobe_buffer_get();
1500 store_trace_args(ucb->buf, &tu->tp, regs, esize, dsize);
1501
1502 if (trace_probe_test_flag(&tu->tp, TP_FLAG_TRACE))
1503 ret |= uprobe_trace_func(tu, regs, ucb, dsize);
1504
1505#ifdef CONFIG_PERF_EVENTS
1506 if (trace_probe_test_flag(&tu->tp, TP_FLAG_PROFILE))
1507 ret |= uprobe_perf_func(tu, regs, ucb, dsize);
1508#endif
1509 uprobe_buffer_put(ucb);
1510 return ret;
1511}
1512
1513static int uretprobe_dispatcher(struct uprobe_consumer *con,
1514 unsigned long func, struct pt_regs *regs)
1515{
1516 struct trace_uprobe *tu;
1517 struct uprobe_dispatch_data udd;
1518 struct uprobe_cpu_buffer *ucb;
1519 int dsize, esize;
1520
1521 tu = container_of(con, struct trace_uprobe, consumer);
1522
1523 udd.tu = tu;
1524 udd.bp_addr = func;
1525
1526 current->utask->vaddr = (unsigned long) &udd;
1527
1528 if (WARN_ON_ONCE(!uprobe_cpu_buffer))
1529 return 0;
1530
1531 dsize = __get_data_size(&tu->tp, regs);
1532 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
1533
1534 ucb = uprobe_buffer_get();
1535 store_trace_args(ucb->buf, &tu->tp, regs, esize, dsize);
1536
1537 if (trace_probe_test_flag(&tu->tp, TP_FLAG_TRACE))
1538 uretprobe_trace_func(tu, func, regs, ucb, dsize);
1539
1540#ifdef CONFIG_PERF_EVENTS
1541 if (trace_probe_test_flag(&tu->tp, TP_FLAG_PROFILE))
1542 uretprobe_perf_func(tu, func, regs, ucb, dsize);
1543#endif
1544 uprobe_buffer_put(ucb);
1545 return 0;
1546}
1547
1548static struct trace_event_functions uprobe_funcs = {
1549 .trace = print_uprobe_event
1550};
1551
1552static struct trace_event_fields uprobe_fields_array[] = {
1553 { .type = TRACE_FUNCTION_TYPE,
1554 .define_fields = uprobe_event_define_fields },
1555 {}
1556};
1557
1558static inline void init_trace_event_call(struct trace_uprobe *tu)
1559{
1560 struct trace_event_call *call = trace_probe_event_call(&tu->tp);
1561 call->event.funcs = &uprobe_funcs;
1562 call->class->fields_array = uprobe_fields_array;
1563
1564 call->flags = TRACE_EVENT_FL_UPROBE | TRACE_EVENT_FL_CAP_ANY;
1565 call->class->reg = trace_uprobe_register;
1566}
1567
1568static int register_uprobe_event(struct trace_uprobe *tu)
1569{
1570 init_trace_event_call(tu);
1571
1572 return trace_probe_register_event_call(&tu->tp);
1573}
1574
1575static int unregister_uprobe_event(struct trace_uprobe *tu)
1576{
1577 return trace_probe_unregister_event_call(&tu->tp);
1578}
1579
1580#ifdef CONFIG_PERF_EVENTS
1581struct trace_event_call *
1582create_local_trace_uprobe(char *name, unsigned long offs,
1583 unsigned long ref_ctr_offset, bool is_return)
1584{
1585 enum probe_print_type ptype;
1586 struct trace_uprobe *tu;
1587 struct path path;
1588 int ret;
1589
1590 ret = kern_path(name, LOOKUP_FOLLOW, &path);
1591 if (ret)
1592 return ERR_PTR(ret);
1593
1594 if (!d_is_reg(path.dentry)) {
1595 path_put(&path);
1596 return ERR_PTR(-EINVAL);
1597 }
1598
1599 /*
1600 * local trace_kprobes are not added to dyn_event, so they are never
1601 * searched in find_trace_kprobe(). Therefore, there is no concern of
1602 * duplicated name "DUMMY_EVENT" here.
1603 */
1604 tu = alloc_trace_uprobe(UPROBE_EVENT_SYSTEM, "DUMMY_EVENT", 0,
1605 is_return);
1606
1607 if (IS_ERR(tu)) {
1608 pr_info("Failed to allocate trace_uprobe.(%d)\n",
1609 (int)PTR_ERR(tu));
1610 path_put(&path);
1611 return ERR_CAST(tu);
1612 }
1613
1614 tu->offset = offs;
1615 tu->path = path;
1616 tu->ref_ctr_offset = ref_ctr_offset;
1617 tu->filename = kstrdup(name, GFP_KERNEL);
1618 if (!tu->filename) {
1619 ret = -ENOMEM;
1620 goto error;
1621 }
1622
1623 init_trace_event_call(tu);
1624
1625 ptype = is_ret_probe(tu) ? PROBE_PRINT_RETURN : PROBE_PRINT_NORMAL;
1626 if (traceprobe_set_print_fmt(&tu->tp, ptype) < 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", TRACE_MODE_WRITE, NULL,
1661 NULL, &uprobe_events_ops);
1662 /* Profile interface */
1663 trace_create_file("uprobe_profile", TRACE_MODE_READ, NULL,
1664 NULL, &uprobe_profile_ops);
1665 return 0;
1666}
1667
1668fs_initcall(init_uprobe_trace);