Loading...
1/*
2 * uprobes-based tracing events
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public License
14 * along with this program; if not, write to the Free Software
15 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
16 *
17 * Copyright (C) IBM Corporation, 2010-2012
18 * Author: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
19 */
20#define pr_fmt(fmt) "trace_kprobe: " fmt
21
22#include <linux/module.h>
23#include <linux/uaccess.h>
24#include <linux/uprobes.h>
25#include <linux/namei.h>
26#include <linux/string.h>
27#include <linux/rculist.h>
28
29#include "trace_probe.h"
30
31#define UPROBE_EVENT_SYSTEM "uprobes"
32
33struct uprobe_trace_entry_head {
34 struct trace_entry ent;
35 unsigned long vaddr[];
36};
37
38#define SIZEOF_TRACE_ENTRY(is_return) \
39 (sizeof(struct uprobe_trace_entry_head) + \
40 sizeof(unsigned long) * (is_return ? 2 : 1))
41
42#define DATAOF_TRACE_ENTRY(entry, is_return) \
43 ((void*)(entry) + SIZEOF_TRACE_ENTRY(is_return))
44
45struct trace_uprobe_filter {
46 rwlock_t rwlock;
47 int nr_systemwide;
48 struct list_head perf_events;
49};
50
51/*
52 * uprobe event core functions
53 */
54struct trace_uprobe {
55 struct list_head list;
56 struct trace_uprobe_filter filter;
57 struct uprobe_consumer consumer;
58 struct path path;
59 struct inode *inode;
60 char *filename;
61 unsigned long offset;
62 unsigned long nhit;
63 struct trace_probe tp;
64};
65
66#define SIZEOF_TRACE_UPROBE(n) \
67 (offsetof(struct trace_uprobe, tp.args) + \
68 (sizeof(struct probe_arg) * (n)))
69
70static int register_uprobe_event(struct trace_uprobe *tu);
71static int unregister_uprobe_event(struct trace_uprobe *tu);
72
73static DEFINE_MUTEX(uprobe_lock);
74static LIST_HEAD(uprobe_list);
75
76struct uprobe_dispatch_data {
77 struct trace_uprobe *tu;
78 unsigned long bp_addr;
79};
80
81static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs);
82static int uretprobe_dispatcher(struct uprobe_consumer *con,
83 unsigned long func, struct pt_regs *regs);
84
85#ifdef CONFIG_STACK_GROWSUP
86static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n)
87{
88 return addr - (n * sizeof(long));
89}
90#else
91static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n)
92{
93 return addr + (n * sizeof(long));
94}
95#endif
96
97static unsigned long get_user_stack_nth(struct pt_regs *regs, unsigned int n)
98{
99 unsigned long ret;
100 unsigned long addr = user_stack_pointer(regs);
101
102 addr = adjust_stack_addr(addr, n);
103
104 if (copy_from_user(&ret, (void __force __user *) addr, sizeof(ret)))
105 return 0;
106
107 return ret;
108}
109
110/*
111 * Uprobes-specific fetch functions
112 */
113#define DEFINE_FETCH_stack(type) \
114static void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs, \
115 void *offset, void *dest) \
116{ \
117 *(type *)dest = (type)get_user_stack_nth(regs, \
118 ((unsigned long)offset)); \
119}
120DEFINE_BASIC_FETCH_FUNCS(stack)
121/* No string on the stack entry */
122#define fetch_stack_string NULL
123#define fetch_stack_string_size NULL
124
125#define DEFINE_FETCH_memory(type) \
126static void FETCH_FUNC_NAME(memory, type)(struct pt_regs *regs, \
127 void *addr, void *dest) \
128{ \
129 type retval; \
130 void __user *vaddr = (void __force __user *) addr; \
131 \
132 if (copy_from_user(&retval, vaddr, sizeof(type))) \
133 *(type *)dest = 0; \
134 else \
135 *(type *) dest = retval; \
136}
137DEFINE_BASIC_FETCH_FUNCS(memory)
138/*
139 * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max
140 * length and relative data location.
141 */
142static void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs,
143 void *addr, void *dest)
144{
145 long ret;
146 u32 rloc = *(u32 *)dest;
147 int maxlen = get_rloc_len(rloc);
148 u8 *dst = get_rloc_data(dest);
149 void __user *src = (void __force __user *) addr;
150
151 if (!maxlen)
152 return;
153
154 ret = strncpy_from_user(dst, src, maxlen);
155 if (ret == maxlen)
156 dst[--ret] = '\0';
157
158 if (ret < 0) { /* Failed to fetch string */
159 ((u8 *)get_rloc_data(dest))[0] = '\0';
160 *(u32 *)dest = make_data_rloc(0, get_rloc_offs(rloc));
161 } else {
162 *(u32 *)dest = make_data_rloc(ret, get_rloc_offs(rloc));
163 }
164}
165
166static void FETCH_FUNC_NAME(memory, string_size)(struct pt_regs *regs,
167 void *addr, void *dest)
168{
169 int len;
170 void __user *vaddr = (void __force __user *) addr;
171
172 len = strnlen_user(vaddr, MAX_STRING_SIZE);
173
174 if (len == 0 || len > MAX_STRING_SIZE) /* Failed to check length */
175 *(u32 *)dest = 0;
176 else
177 *(u32 *)dest = len;
178}
179
180static unsigned long translate_user_vaddr(void *file_offset)
181{
182 unsigned long base_addr;
183 struct uprobe_dispatch_data *udd;
184
185 udd = (void *) current->utask->vaddr;
186
187 base_addr = udd->bp_addr - udd->tu->offset;
188 return base_addr + (unsigned long)file_offset;
189}
190
191#define DEFINE_FETCH_file_offset(type) \
192static void FETCH_FUNC_NAME(file_offset, type)(struct pt_regs *regs, \
193 void *offset, void *dest)\
194{ \
195 void *vaddr = (void *)translate_user_vaddr(offset); \
196 \
197 FETCH_FUNC_NAME(memory, type)(regs, vaddr, dest); \
198}
199DEFINE_BASIC_FETCH_FUNCS(file_offset)
200DEFINE_FETCH_file_offset(string)
201DEFINE_FETCH_file_offset(string_size)
202
203/* Fetch type information table */
204static const struct fetch_type uprobes_fetch_type_table[] = {
205 /* Special types */
206 [FETCH_TYPE_STRING] = __ASSIGN_FETCH_TYPE("string", string, string,
207 sizeof(u32), 1, "__data_loc char[]"),
208 [FETCH_TYPE_STRSIZE] = __ASSIGN_FETCH_TYPE("string_size", u32,
209 string_size, sizeof(u32), 0, "u32"),
210 /* Basic types */
211 ASSIGN_FETCH_TYPE(u8, u8, 0),
212 ASSIGN_FETCH_TYPE(u16, u16, 0),
213 ASSIGN_FETCH_TYPE(u32, u32, 0),
214 ASSIGN_FETCH_TYPE(u64, u64, 0),
215 ASSIGN_FETCH_TYPE(s8, u8, 1),
216 ASSIGN_FETCH_TYPE(s16, u16, 1),
217 ASSIGN_FETCH_TYPE(s32, u32, 1),
218 ASSIGN_FETCH_TYPE(s64, u64, 1),
219 ASSIGN_FETCH_TYPE_ALIAS(x8, u8, u8, 0),
220 ASSIGN_FETCH_TYPE_ALIAS(x16, u16, u16, 0),
221 ASSIGN_FETCH_TYPE_ALIAS(x32, u32, u32, 0),
222 ASSIGN_FETCH_TYPE_ALIAS(x64, u64, u64, 0),
223
224 ASSIGN_FETCH_TYPE_END
225};
226
227static inline void init_trace_uprobe_filter(struct trace_uprobe_filter *filter)
228{
229 rwlock_init(&filter->rwlock);
230 filter->nr_systemwide = 0;
231 INIT_LIST_HEAD(&filter->perf_events);
232}
233
234static inline bool uprobe_filter_is_empty(struct trace_uprobe_filter *filter)
235{
236 return !filter->nr_systemwide && list_empty(&filter->perf_events);
237}
238
239static inline bool is_ret_probe(struct trace_uprobe *tu)
240{
241 return tu->consumer.ret_handler != NULL;
242}
243
244/*
245 * Allocate new trace_uprobe and initialize it (including uprobes).
246 */
247static struct trace_uprobe *
248alloc_trace_uprobe(const char *group, const char *event, int nargs, bool is_ret)
249{
250 struct trace_uprobe *tu;
251
252 if (!event || !is_good_name(event))
253 return ERR_PTR(-EINVAL);
254
255 if (!group || !is_good_name(group))
256 return ERR_PTR(-EINVAL);
257
258 tu = kzalloc(SIZEOF_TRACE_UPROBE(nargs), GFP_KERNEL);
259 if (!tu)
260 return ERR_PTR(-ENOMEM);
261
262 tu->tp.call.class = &tu->tp.class;
263 tu->tp.call.name = kstrdup(event, GFP_KERNEL);
264 if (!tu->tp.call.name)
265 goto error;
266
267 tu->tp.class.system = kstrdup(group, GFP_KERNEL);
268 if (!tu->tp.class.system)
269 goto error;
270
271 INIT_LIST_HEAD(&tu->list);
272 INIT_LIST_HEAD(&tu->tp.files);
273 tu->consumer.handler = uprobe_dispatcher;
274 if (is_ret)
275 tu->consumer.ret_handler = uretprobe_dispatcher;
276 init_trace_uprobe_filter(&tu->filter);
277 return tu;
278
279error:
280 kfree(tu->tp.call.name);
281 kfree(tu);
282
283 return ERR_PTR(-ENOMEM);
284}
285
286static void free_trace_uprobe(struct trace_uprobe *tu)
287{
288 int i;
289
290 for (i = 0; i < tu->tp.nr_args; i++)
291 traceprobe_free_probe_arg(&tu->tp.args[i]);
292
293 path_put(&tu->path);
294 kfree(tu->tp.call.class->system);
295 kfree(tu->tp.call.name);
296 kfree(tu->filename);
297 kfree(tu);
298}
299
300static struct trace_uprobe *find_probe_event(const char *event, const char *group)
301{
302 struct trace_uprobe *tu;
303
304 list_for_each_entry(tu, &uprobe_list, list)
305 if (strcmp(trace_event_name(&tu->tp.call), event) == 0 &&
306 strcmp(tu->tp.call.class->system, group) == 0)
307 return tu;
308
309 return NULL;
310}
311
312/* Unregister a trace_uprobe and probe_event: call with locking uprobe_lock */
313static int unregister_trace_uprobe(struct trace_uprobe *tu)
314{
315 int ret;
316
317 ret = unregister_uprobe_event(tu);
318 if (ret)
319 return ret;
320
321 list_del(&tu->list);
322 free_trace_uprobe(tu);
323 return 0;
324}
325
326/* Register a trace_uprobe and probe_event */
327static int register_trace_uprobe(struct trace_uprobe *tu)
328{
329 struct trace_uprobe *old_tu;
330 int ret;
331
332 mutex_lock(&uprobe_lock);
333
334 /* register as an event */
335 old_tu = find_probe_event(trace_event_name(&tu->tp.call),
336 tu->tp.call.class->system);
337 if (old_tu) {
338 /* delete old event */
339 ret = unregister_trace_uprobe(old_tu);
340 if (ret)
341 goto end;
342 }
343
344 ret = register_uprobe_event(tu);
345 if (ret) {
346 pr_warn("Failed to register probe event(%d)\n", ret);
347 goto end;
348 }
349
350 list_add_tail(&tu->list, &uprobe_list);
351
352end:
353 mutex_unlock(&uprobe_lock);
354
355 return ret;
356}
357
358/*
359 * Argument syntax:
360 * - Add uprobe: p|r[:[GRP/]EVENT] PATH:OFFSET [FETCHARGS]
361 *
362 * - Remove uprobe: -:[GRP/]EVENT
363 */
364static int create_trace_uprobe(int argc, char **argv)
365{
366 struct trace_uprobe *tu;
367 char *arg, *event, *group, *filename;
368 char buf[MAX_EVENT_NAME_LEN];
369 struct path path;
370 unsigned long offset;
371 bool is_delete, is_return;
372 int i, ret;
373
374 ret = 0;
375 is_delete = false;
376 is_return = false;
377 event = NULL;
378 group = NULL;
379
380 /* argc must be >= 1 */
381 if (argv[0][0] == '-')
382 is_delete = true;
383 else if (argv[0][0] == 'r')
384 is_return = true;
385 else if (argv[0][0] != 'p') {
386 pr_info("Probe definition must be started with 'p', 'r' or '-'.\n");
387 return -EINVAL;
388 }
389
390 if (argv[0][1] == ':') {
391 event = &argv[0][2];
392 arg = strchr(event, '/');
393
394 if (arg) {
395 group = event;
396 event = arg + 1;
397 event[-1] = '\0';
398
399 if (strlen(group) == 0) {
400 pr_info("Group name is not specified\n");
401 return -EINVAL;
402 }
403 }
404 if (strlen(event) == 0) {
405 pr_info("Event name is not specified\n");
406 return -EINVAL;
407 }
408 }
409 if (!group)
410 group = UPROBE_EVENT_SYSTEM;
411
412 if (is_delete) {
413 int ret;
414
415 if (!event) {
416 pr_info("Delete command needs an event name.\n");
417 return -EINVAL;
418 }
419 mutex_lock(&uprobe_lock);
420 tu = find_probe_event(event, group);
421
422 if (!tu) {
423 mutex_unlock(&uprobe_lock);
424 pr_info("Event %s/%s doesn't exist.\n", group, event);
425 return -ENOENT;
426 }
427 /* delete an event */
428 ret = unregister_trace_uprobe(tu);
429 mutex_unlock(&uprobe_lock);
430 return ret;
431 }
432
433 if (argc < 2) {
434 pr_info("Probe point is not specified.\n");
435 return -EINVAL;
436 }
437 /* Find the last occurrence, in case the path contains ':' too. */
438 arg = strrchr(argv[1], ':');
439 if (!arg)
440 return -EINVAL;
441
442 *arg++ = '\0';
443 filename = argv[1];
444 ret = kern_path(filename, LOOKUP_FOLLOW, &path);
445 if (ret)
446 return ret;
447
448 if (!d_is_reg(path.dentry)) {
449 ret = -EINVAL;
450 goto fail_address_parse;
451 }
452
453 ret = kstrtoul(arg, 0, &offset);
454 if (ret)
455 goto fail_address_parse;
456
457 argc -= 2;
458 argv += 2;
459
460 /* setup a probe */
461 if (!event) {
462 char *tail;
463 char *ptr;
464
465 tail = kstrdup(kbasename(filename), GFP_KERNEL);
466 if (!tail) {
467 ret = -ENOMEM;
468 goto fail_address_parse;
469 }
470
471 ptr = strpbrk(tail, ".-_");
472 if (ptr)
473 *ptr = '\0';
474
475 snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_0x%lx", 'p', tail, offset);
476 event = buf;
477 kfree(tail);
478 }
479
480 tu = alloc_trace_uprobe(group, event, argc, is_return);
481 if (IS_ERR(tu)) {
482 pr_info("Failed to allocate trace_uprobe.(%d)\n", (int)PTR_ERR(tu));
483 ret = PTR_ERR(tu);
484 goto fail_address_parse;
485 }
486 tu->offset = offset;
487 tu->path = path;
488 tu->filename = kstrdup(filename, GFP_KERNEL);
489
490 if (!tu->filename) {
491 pr_info("Failed to allocate filename.\n");
492 ret = -ENOMEM;
493 goto error;
494 }
495
496 /* parse arguments */
497 ret = 0;
498 for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) {
499 struct probe_arg *parg = &tu->tp.args[i];
500
501 /* Increment count for freeing args in error case */
502 tu->tp.nr_args++;
503
504 /* Parse argument name */
505 arg = strchr(argv[i], '=');
506 if (arg) {
507 *arg++ = '\0';
508 parg->name = kstrdup(argv[i], GFP_KERNEL);
509 } else {
510 arg = argv[i];
511 /* If argument name is omitted, set "argN" */
512 snprintf(buf, MAX_EVENT_NAME_LEN, "arg%d", i + 1);
513 parg->name = kstrdup(buf, GFP_KERNEL);
514 }
515
516 if (!parg->name) {
517 pr_info("Failed to allocate argument[%d] name.\n", i);
518 ret = -ENOMEM;
519 goto error;
520 }
521
522 if (!is_good_name(parg->name)) {
523 pr_info("Invalid argument[%d] name: %s\n", i, parg->name);
524 ret = -EINVAL;
525 goto error;
526 }
527
528 if (traceprobe_conflict_field_name(parg->name, tu->tp.args, i)) {
529 pr_info("Argument[%d] name '%s' conflicts with "
530 "another field.\n", i, argv[i]);
531 ret = -EINVAL;
532 goto error;
533 }
534
535 /* Parse fetch argument */
536 ret = traceprobe_parse_probe_arg(arg, &tu->tp.size, parg,
537 is_return, false,
538 uprobes_fetch_type_table);
539 if (ret) {
540 pr_info("Parse error at argument[%d]. (%d)\n", i, ret);
541 goto error;
542 }
543 }
544
545 ret = register_trace_uprobe(tu);
546 if (ret)
547 goto error;
548 return 0;
549
550error:
551 free_trace_uprobe(tu);
552 return ret;
553
554fail_address_parse:
555 path_put(&path);
556
557 pr_info("Failed to parse address or file.\n");
558
559 return ret;
560}
561
562static int cleanup_all_probes(void)
563{
564 struct trace_uprobe *tu;
565 int ret = 0;
566
567 mutex_lock(&uprobe_lock);
568 while (!list_empty(&uprobe_list)) {
569 tu = list_entry(uprobe_list.next, struct trace_uprobe, list);
570 ret = unregister_trace_uprobe(tu);
571 if (ret)
572 break;
573 }
574 mutex_unlock(&uprobe_lock);
575 return ret;
576}
577
578/* Probes listing interfaces */
579static void *probes_seq_start(struct seq_file *m, loff_t *pos)
580{
581 mutex_lock(&uprobe_lock);
582 return seq_list_start(&uprobe_list, *pos);
583}
584
585static void *probes_seq_next(struct seq_file *m, void *v, loff_t *pos)
586{
587 return seq_list_next(v, &uprobe_list, pos);
588}
589
590static void probes_seq_stop(struct seq_file *m, void *v)
591{
592 mutex_unlock(&uprobe_lock);
593}
594
595static int probes_seq_show(struct seq_file *m, void *v)
596{
597 struct trace_uprobe *tu = v;
598 char c = is_ret_probe(tu) ? 'r' : 'p';
599 int i;
600
601 seq_printf(m, "%c:%s/%s %s:0x%0*lx", c, tu->tp.call.class->system,
602 trace_event_name(&tu->tp.call), tu->filename,
603 (int)(sizeof(void *) * 2), tu->offset);
604
605 for (i = 0; i < tu->tp.nr_args; i++)
606 seq_printf(m, " %s=%s", tu->tp.args[i].name, tu->tp.args[i].comm);
607
608 seq_putc(m, '\n');
609 return 0;
610}
611
612static const struct seq_operations probes_seq_op = {
613 .start = probes_seq_start,
614 .next = probes_seq_next,
615 .stop = probes_seq_stop,
616 .show = probes_seq_show
617};
618
619static int probes_open(struct inode *inode, struct file *file)
620{
621 int ret;
622
623 if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
624 ret = cleanup_all_probes();
625 if (ret)
626 return ret;
627 }
628
629 return seq_open(file, &probes_seq_op);
630}
631
632static ssize_t probes_write(struct file *file, const char __user *buffer,
633 size_t count, loff_t *ppos)
634{
635 return trace_parse_run_command(file, buffer, count, ppos, create_trace_uprobe);
636}
637
638static const struct file_operations uprobe_events_ops = {
639 .owner = THIS_MODULE,
640 .open = probes_open,
641 .read = seq_read,
642 .llseek = seq_lseek,
643 .release = seq_release,
644 .write = probes_write,
645};
646
647/* Probes profiling interfaces */
648static int probes_profile_seq_show(struct seq_file *m, void *v)
649{
650 struct trace_uprobe *tu = v;
651
652 seq_printf(m, " %s %-44s %15lu\n", tu->filename,
653 trace_event_name(&tu->tp.call), tu->nhit);
654 return 0;
655}
656
657static const struct seq_operations profile_seq_op = {
658 .start = probes_seq_start,
659 .next = probes_seq_next,
660 .stop = probes_seq_stop,
661 .show = probes_profile_seq_show
662};
663
664static int profile_open(struct inode *inode, struct file *file)
665{
666 return seq_open(file, &profile_seq_op);
667}
668
669static const struct file_operations uprobe_profile_ops = {
670 .owner = THIS_MODULE,
671 .open = profile_open,
672 .read = seq_read,
673 .llseek = seq_lseek,
674 .release = seq_release,
675};
676
677struct uprobe_cpu_buffer {
678 struct mutex mutex;
679 void *buf;
680};
681static struct uprobe_cpu_buffer __percpu *uprobe_cpu_buffer;
682static int uprobe_buffer_refcnt;
683
684static int uprobe_buffer_init(void)
685{
686 int cpu, err_cpu;
687
688 uprobe_cpu_buffer = alloc_percpu(struct uprobe_cpu_buffer);
689 if (uprobe_cpu_buffer == NULL)
690 return -ENOMEM;
691
692 for_each_possible_cpu(cpu) {
693 struct page *p = alloc_pages_node(cpu_to_node(cpu),
694 GFP_KERNEL, 0);
695 if (p == NULL) {
696 err_cpu = cpu;
697 goto err;
698 }
699 per_cpu_ptr(uprobe_cpu_buffer, cpu)->buf = page_address(p);
700 mutex_init(&per_cpu_ptr(uprobe_cpu_buffer, cpu)->mutex);
701 }
702
703 return 0;
704
705err:
706 for_each_possible_cpu(cpu) {
707 if (cpu == err_cpu)
708 break;
709 free_page((unsigned long)per_cpu_ptr(uprobe_cpu_buffer, cpu)->buf);
710 }
711
712 free_percpu(uprobe_cpu_buffer);
713 return -ENOMEM;
714}
715
716static int uprobe_buffer_enable(void)
717{
718 int ret = 0;
719
720 BUG_ON(!mutex_is_locked(&event_mutex));
721
722 if (uprobe_buffer_refcnt++ == 0) {
723 ret = uprobe_buffer_init();
724 if (ret < 0)
725 uprobe_buffer_refcnt--;
726 }
727
728 return ret;
729}
730
731static void uprobe_buffer_disable(void)
732{
733 int cpu;
734
735 BUG_ON(!mutex_is_locked(&event_mutex));
736
737 if (--uprobe_buffer_refcnt == 0) {
738 for_each_possible_cpu(cpu)
739 free_page((unsigned long)per_cpu_ptr(uprobe_cpu_buffer,
740 cpu)->buf);
741
742 free_percpu(uprobe_cpu_buffer);
743 uprobe_cpu_buffer = NULL;
744 }
745}
746
747static struct uprobe_cpu_buffer *uprobe_buffer_get(void)
748{
749 struct uprobe_cpu_buffer *ucb;
750 int cpu;
751
752 cpu = raw_smp_processor_id();
753 ucb = per_cpu_ptr(uprobe_cpu_buffer, cpu);
754
755 /*
756 * Use per-cpu buffers for fastest access, but we might migrate
757 * so the mutex makes sure we have sole access to it.
758 */
759 mutex_lock(&ucb->mutex);
760
761 return ucb;
762}
763
764static void uprobe_buffer_put(struct uprobe_cpu_buffer *ucb)
765{
766 mutex_unlock(&ucb->mutex);
767}
768
769static void __uprobe_trace_func(struct trace_uprobe *tu,
770 unsigned long func, struct pt_regs *regs,
771 struct uprobe_cpu_buffer *ucb, int dsize,
772 struct trace_event_file *trace_file)
773{
774 struct uprobe_trace_entry_head *entry;
775 struct ring_buffer_event *event;
776 struct ring_buffer *buffer;
777 void *data;
778 int size, esize;
779 struct trace_event_call *call = &tu->tp.call;
780
781 WARN_ON(call != trace_file->event_call);
782
783 if (WARN_ON_ONCE(tu->tp.size + dsize > PAGE_SIZE))
784 return;
785
786 if (trace_trigger_soft_disabled(trace_file))
787 return;
788
789 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
790 size = esize + tu->tp.size + dsize;
791 event = trace_event_buffer_lock_reserve(&buffer, trace_file,
792 call->event.type, size, 0, 0);
793 if (!event)
794 return;
795
796 entry = ring_buffer_event_data(event);
797 if (is_ret_probe(tu)) {
798 entry->vaddr[0] = func;
799 entry->vaddr[1] = instruction_pointer(regs);
800 data = DATAOF_TRACE_ENTRY(entry, true);
801 } else {
802 entry->vaddr[0] = instruction_pointer(regs);
803 data = DATAOF_TRACE_ENTRY(entry, false);
804 }
805
806 memcpy(data, ucb->buf, tu->tp.size + dsize);
807
808 event_trigger_unlock_commit(trace_file, buffer, event, entry, 0, 0);
809}
810
811/* uprobe handler */
812static int uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs,
813 struct uprobe_cpu_buffer *ucb, int dsize)
814{
815 struct event_file_link *link;
816
817 if (is_ret_probe(tu))
818 return 0;
819
820 rcu_read_lock();
821 list_for_each_entry_rcu(link, &tu->tp.files, list)
822 __uprobe_trace_func(tu, 0, regs, ucb, dsize, link->file);
823 rcu_read_unlock();
824
825 return 0;
826}
827
828static void uretprobe_trace_func(struct trace_uprobe *tu, unsigned long func,
829 struct pt_regs *regs,
830 struct uprobe_cpu_buffer *ucb, int dsize)
831{
832 struct event_file_link *link;
833
834 rcu_read_lock();
835 list_for_each_entry_rcu(link, &tu->tp.files, list)
836 __uprobe_trace_func(tu, func, regs, ucb, dsize, link->file);
837 rcu_read_unlock();
838}
839
840/* Event entry printers */
841static enum print_line_t
842print_uprobe_event(struct trace_iterator *iter, int flags, struct trace_event *event)
843{
844 struct uprobe_trace_entry_head *entry;
845 struct trace_seq *s = &iter->seq;
846 struct trace_uprobe *tu;
847 u8 *data;
848 int i;
849
850 entry = (struct uprobe_trace_entry_head *)iter->ent;
851 tu = container_of(event, struct trace_uprobe, tp.call.event);
852
853 if (is_ret_probe(tu)) {
854 trace_seq_printf(s, "%s: (0x%lx <- 0x%lx)",
855 trace_event_name(&tu->tp.call),
856 entry->vaddr[1], entry->vaddr[0]);
857 data = DATAOF_TRACE_ENTRY(entry, true);
858 } else {
859 trace_seq_printf(s, "%s: (0x%lx)",
860 trace_event_name(&tu->tp.call),
861 entry->vaddr[0]);
862 data = DATAOF_TRACE_ENTRY(entry, false);
863 }
864
865 for (i = 0; i < tu->tp.nr_args; i++) {
866 struct probe_arg *parg = &tu->tp.args[i];
867
868 if (!parg->type->print(s, parg->name, data + parg->offset, entry))
869 goto out;
870 }
871
872 trace_seq_putc(s, '\n');
873
874 out:
875 return trace_handle_return(s);
876}
877
878typedef bool (*filter_func_t)(struct uprobe_consumer *self,
879 enum uprobe_filter_ctx ctx,
880 struct mm_struct *mm);
881
882static int
883probe_event_enable(struct trace_uprobe *tu, struct trace_event_file *file,
884 filter_func_t filter)
885{
886 bool enabled = trace_probe_is_enabled(&tu->tp);
887 struct event_file_link *link = NULL;
888 int ret;
889
890 if (file) {
891 if (tu->tp.flags & TP_FLAG_PROFILE)
892 return -EINTR;
893
894 link = kmalloc(sizeof(*link), GFP_KERNEL);
895 if (!link)
896 return -ENOMEM;
897
898 link->file = file;
899 list_add_tail_rcu(&link->list, &tu->tp.files);
900
901 tu->tp.flags |= TP_FLAG_TRACE;
902 } else {
903 if (tu->tp.flags & TP_FLAG_TRACE)
904 return -EINTR;
905
906 tu->tp.flags |= TP_FLAG_PROFILE;
907 }
908
909 WARN_ON(!uprobe_filter_is_empty(&tu->filter));
910
911 if (enabled)
912 return 0;
913
914 ret = uprobe_buffer_enable();
915 if (ret)
916 goto err_flags;
917
918 tu->consumer.filter = filter;
919 tu->inode = d_real_inode(tu->path.dentry);
920 ret = uprobe_register(tu->inode, tu->offset, &tu->consumer);
921 if (ret)
922 goto err_buffer;
923
924 return 0;
925
926 err_buffer:
927 uprobe_buffer_disable();
928
929 err_flags:
930 if (file) {
931 list_del(&link->list);
932 kfree(link);
933 tu->tp.flags &= ~TP_FLAG_TRACE;
934 } else {
935 tu->tp.flags &= ~TP_FLAG_PROFILE;
936 }
937 return ret;
938}
939
940static void
941probe_event_disable(struct trace_uprobe *tu, struct trace_event_file *file)
942{
943 if (!trace_probe_is_enabled(&tu->tp))
944 return;
945
946 if (file) {
947 struct event_file_link *link;
948
949 link = find_event_file_link(&tu->tp, file);
950 if (!link)
951 return;
952
953 list_del_rcu(&link->list);
954 /* synchronize with u{,ret}probe_trace_func */
955 synchronize_sched();
956 kfree(link);
957
958 if (!list_empty(&tu->tp.files))
959 return;
960 }
961
962 WARN_ON(!uprobe_filter_is_empty(&tu->filter));
963
964 uprobe_unregister(tu->inode, tu->offset, &tu->consumer);
965 tu->inode = NULL;
966 tu->tp.flags &= file ? ~TP_FLAG_TRACE : ~TP_FLAG_PROFILE;
967
968 uprobe_buffer_disable();
969}
970
971static int uprobe_event_define_fields(struct trace_event_call *event_call)
972{
973 int ret, i, size;
974 struct uprobe_trace_entry_head field;
975 struct trace_uprobe *tu = event_call->data;
976
977 if (is_ret_probe(tu)) {
978 DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_FUNC, 0);
979 DEFINE_FIELD(unsigned long, vaddr[1], FIELD_STRING_RETIP, 0);
980 size = SIZEOF_TRACE_ENTRY(true);
981 } else {
982 DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_IP, 0);
983 size = SIZEOF_TRACE_ENTRY(false);
984 }
985 /* Set argument names as fields */
986 for (i = 0; i < tu->tp.nr_args; i++) {
987 struct probe_arg *parg = &tu->tp.args[i];
988
989 ret = trace_define_field(event_call, parg->type->fmttype,
990 parg->name, size + parg->offset,
991 parg->type->size, parg->type->is_signed,
992 FILTER_OTHER);
993
994 if (ret)
995 return ret;
996 }
997 return 0;
998}
999
1000#ifdef CONFIG_PERF_EVENTS
1001static bool
1002__uprobe_perf_filter(struct trace_uprobe_filter *filter, struct mm_struct *mm)
1003{
1004 struct perf_event *event;
1005
1006 if (filter->nr_systemwide)
1007 return true;
1008
1009 list_for_each_entry(event, &filter->perf_events, hw.tp_list) {
1010 if (event->hw.target->mm == mm)
1011 return true;
1012 }
1013
1014 return false;
1015}
1016
1017static inline bool
1018uprobe_filter_event(struct trace_uprobe *tu, struct perf_event *event)
1019{
1020 return __uprobe_perf_filter(&tu->filter, event->hw.target->mm);
1021}
1022
1023static int uprobe_perf_close(struct trace_uprobe *tu, struct perf_event *event)
1024{
1025 bool done;
1026
1027 write_lock(&tu->filter.rwlock);
1028 if (event->hw.target) {
1029 list_del(&event->hw.tp_list);
1030 done = tu->filter.nr_systemwide ||
1031 (event->hw.target->flags & PF_EXITING) ||
1032 uprobe_filter_event(tu, event);
1033 } else {
1034 tu->filter.nr_systemwide--;
1035 done = tu->filter.nr_systemwide;
1036 }
1037 write_unlock(&tu->filter.rwlock);
1038
1039 if (!done)
1040 return uprobe_apply(tu->inode, tu->offset, &tu->consumer, false);
1041
1042 return 0;
1043}
1044
1045static int uprobe_perf_open(struct trace_uprobe *tu, struct perf_event *event)
1046{
1047 bool done;
1048 int err;
1049
1050 write_lock(&tu->filter.rwlock);
1051 if (event->hw.target) {
1052 /*
1053 * event->parent != NULL means copy_process(), we can avoid
1054 * uprobe_apply(). current->mm must be probed and we can rely
1055 * on dup_mmap() which preserves the already installed bp's.
1056 *
1057 * attr.enable_on_exec means that exec/mmap will install the
1058 * breakpoints we need.
1059 */
1060 done = tu->filter.nr_systemwide ||
1061 event->parent || event->attr.enable_on_exec ||
1062 uprobe_filter_event(tu, event);
1063 list_add(&event->hw.tp_list, &tu->filter.perf_events);
1064 } else {
1065 done = tu->filter.nr_systemwide;
1066 tu->filter.nr_systemwide++;
1067 }
1068 write_unlock(&tu->filter.rwlock);
1069
1070 err = 0;
1071 if (!done) {
1072 err = uprobe_apply(tu->inode, tu->offset, &tu->consumer, true);
1073 if (err)
1074 uprobe_perf_close(tu, event);
1075 }
1076 return err;
1077}
1078
1079static bool uprobe_perf_filter(struct uprobe_consumer *uc,
1080 enum uprobe_filter_ctx ctx, struct mm_struct *mm)
1081{
1082 struct trace_uprobe *tu;
1083 int ret;
1084
1085 tu = container_of(uc, struct trace_uprobe, consumer);
1086 read_lock(&tu->filter.rwlock);
1087 ret = __uprobe_perf_filter(&tu->filter, mm);
1088 read_unlock(&tu->filter.rwlock);
1089
1090 return ret;
1091}
1092
1093static void __uprobe_perf_func(struct trace_uprobe *tu,
1094 unsigned long func, struct pt_regs *regs,
1095 struct uprobe_cpu_buffer *ucb, int dsize)
1096{
1097 struct trace_event_call *call = &tu->tp.call;
1098 struct uprobe_trace_entry_head *entry;
1099 struct hlist_head *head;
1100 void *data;
1101 int size, esize;
1102 int rctx;
1103
1104 if (bpf_prog_array_valid(call) && !trace_call_bpf(call, regs))
1105 return;
1106
1107 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
1108
1109 size = esize + tu->tp.size + dsize;
1110 size = ALIGN(size + sizeof(u32), sizeof(u64)) - sizeof(u32);
1111 if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, "profile buffer not large enough"))
1112 return;
1113
1114 preempt_disable();
1115 head = this_cpu_ptr(call->perf_events);
1116 if (hlist_empty(head))
1117 goto out;
1118
1119 entry = perf_trace_buf_alloc(size, NULL, &rctx);
1120 if (!entry)
1121 goto out;
1122
1123 if (is_ret_probe(tu)) {
1124 entry->vaddr[0] = func;
1125 entry->vaddr[1] = instruction_pointer(regs);
1126 data = DATAOF_TRACE_ENTRY(entry, true);
1127 } else {
1128 entry->vaddr[0] = instruction_pointer(regs);
1129 data = DATAOF_TRACE_ENTRY(entry, false);
1130 }
1131
1132 memcpy(data, ucb->buf, tu->tp.size + dsize);
1133
1134 if (size - esize > tu->tp.size + dsize) {
1135 int len = tu->tp.size + dsize;
1136
1137 memset(data + len, 0, size - esize - len);
1138 }
1139
1140 perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs,
1141 head, NULL);
1142 out:
1143 preempt_enable();
1144}
1145
1146/* uprobe profile handler */
1147static int uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs,
1148 struct uprobe_cpu_buffer *ucb, int dsize)
1149{
1150 if (!uprobe_perf_filter(&tu->consumer, 0, current->mm))
1151 return UPROBE_HANDLER_REMOVE;
1152
1153 if (!is_ret_probe(tu))
1154 __uprobe_perf_func(tu, 0, regs, ucb, dsize);
1155 return 0;
1156}
1157
1158static void uretprobe_perf_func(struct trace_uprobe *tu, unsigned long func,
1159 struct pt_regs *regs,
1160 struct uprobe_cpu_buffer *ucb, int dsize)
1161{
1162 __uprobe_perf_func(tu, func, regs, ucb, dsize);
1163}
1164#endif /* CONFIG_PERF_EVENTS */
1165
1166static int
1167trace_uprobe_register(struct trace_event_call *event, enum trace_reg type,
1168 void *data)
1169{
1170 struct trace_uprobe *tu = event->data;
1171 struct trace_event_file *file = data;
1172
1173 switch (type) {
1174 case TRACE_REG_REGISTER:
1175 return probe_event_enable(tu, file, NULL);
1176
1177 case TRACE_REG_UNREGISTER:
1178 probe_event_disable(tu, file);
1179 return 0;
1180
1181#ifdef CONFIG_PERF_EVENTS
1182 case TRACE_REG_PERF_REGISTER:
1183 return probe_event_enable(tu, NULL, uprobe_perf_filter);
1184
1185 case TRACE_REG_PERF_UNREGISTER:
1186 probe_event_disable(tu, NULL);
1187 return 0;
1188
1189 case TRACE_REG_PERF_OPEN:
1190 return uprobe_perf_open(tu, data);
1191
1192 case TRACE_REG_PERF_CLOSE:
1193 return uprobe_perf_close(tu, data);
1194
1195#endif
1196 default:
1197 return 0;
1198 }
1199 return 0;
1200}
1201
1202static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs)
1203{
1204 struct trace_uprobe *tu;
1205 struct uprobe_dispatch_data udd;
1206 struct uprobe_cpu_buffer *ucb;
1207 int dsize, esize;
1208 int ret = 0;
1209
1210
1211 tu = container_of(con, struct trace_uprobe, consumer);
1212 tu->nhit++;
1213
1214 udd.tu = tu;
1215 udd.bp_addr = instruction_pointer(regs);
1216
1217 current->utask->vaddr = (unsigned long) &udd;
1218
1219 if (WARN_ON_ONCE(!uprobe_cpu_buffer))
1220 return 0;
1221
1222 dsize = __get_data_size(&tu->tp, regs);
1223 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
1224
1225 ucb = uprobe_buffer_get();
1226 store_trace_args(esize, &tu->tp, regs, ucb->buf, dsize);
1227
1228 if (tu->tp.flags & TP_FLAG_TRACE)
1229 ret |= uprobe_trace_func(tu, regs, ucb, dsize);
1230
1231#ifdef CONFIG_PERF_EVENTS
1232 if (tu->tp.flags & TP_FLAG_PROFILE)
1233 ret |= uprobe_perf_func(tu, regs, ucb, dsize);
1234#endif
1235 uprobe_buffer_put(ucb);
1236 return ret;
1237}
1238
1239static int uretprobe_dispatcher(struct uprobe_consumer *con,
1240 unsigned long func, struct pt_regs *regs)
1241{
1242 struct trace_uprobe *tu;
1243 struct uprobe_dispatch_data udd;
1244 struct uprobe_cpu_buffer *ucb;
1245 int dsize, esize;
1246
1247 tu = container_of(con, struct trace_uprobe, consumer);
1248
1249 udd.tu = tu;
1250 udd.bp_addr = func;
1251
1252 current->utask->vaddr = (unsigned long) &udd;
1253
1254 if (WARN_ON_ONCE(!uprobe_cpu_buffer))
1255 return 0;
1256
1257 dsize = __get_data_size(&tu->tp, regs);
1258 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
1259
1260 ucb = uprobe_buffer_get();
1261 store_trace_args(esize, &tu->tp, regs, ucb->buf, dsize);
1262
1263 if (tu->tp.flags & TP_FLAG_TRACE)
1264 uretprobe_trace_func(tu, func, regs, ucb, dsize);
1265
1266#ifdef CONFIG_PERF_EVENTS
1267 if (tu->tp.flags & TP_FLAG_PROFILE)
1268 uretprobe_perf_func(tu, func, regs, ucb, dsize);
1269#endif
1270 uprobe_buffer_put(ucb);
1271 return 0;
1272}
1273
1274static struct trace_event_functions uprobe_funcs = {
1275 .trace = print_uprobe_event
1276};
1277
1278static inline void init_trace_event_call(struct trace_uprobe *tu,
1279 struct trace_event_call *call)
1280{
1281 INIT_LIST_HEAD(&call->class->fields);
1282 call->event.funcs = &uprobe_funcs;
1283 call->class->define_fields = uprobe_event_define_fields;
1284
1285 call->flags = TRACE_EVENT_FL_UPROBE;
1286 call->class->reg = trace_uprobe_register;
1287 call->data = tu;
1288}
1289
1290static int register_uprobe_event(struct trace_uprobe *tu)
1291{
1292 struct trace_event_call *call = &tu->tp.call;
1293 int ret = 0;
1294
1295 init_trace_event_call(tu, call);
1296
1297 if (set_print_fmt(&tu->tp, is_ret_probe(tu)) < 0)
1298 return -ENOMEM;
1299
1300 ret = register_trace_event(&call->event);
1301 if (!ret) {
1302 kfree(call->print_fmt);
1303 return -ENODEV;
1304 }
1305
1306 ret = trace_add_event_call(call);
1307
1308 if (ret) {
1309 pr_info("Failed to register uprobe event: %s\n",
1310 trace_event_name(call));
1311 kfree(call->print_fmt);
1312 unregister_trace_event(&call->event);
1313 }
1314
1315 return ret;
1316}
1317
1318static int unregister_uprobe_event(struct trace_uprobe *tu)
1319{
1320 int ret;
1321
1322 /* tu->event is unregistered in trace_remove_event_call() */
1323 ret = trace_remove_event_call(&tu->tp.call);
1324 if (ret)
1325 return ret;
1326 kfree(tu->tp.call.print_fmt);
1327 tu->tp.call.print_fmt = NULL;
1328 return 0;
1329}
1330
1331#ifdef CONFIG_PERF_EVENTS
1332struct trace_event_call *
1333create_local_trace_uprobe(char *name, unsigned long offs, bool is_return)
1334{
1335 struct trace_uprobe *tu;
1336 struct path path;
1337 int ret;
1338
1339 ret = kern_path(name, LOOKUP_FOLLOW, &path);
1340 if (ret)
1341 return ERR_PTR(ret);
1342
1343 if (!d_is_reg(path.dentry)) {
1344 path_put(&path);
1345 return ERR_PTR(-EINVAL);
1346 }
1347
1348 /*
1349 * local trace_kprobes are not added to probe_list, so they are never
1350 * searched in find_trace_kprobe(). Therefore, there is no concern of
1351 * duplicated name "DUMMY_EVENT" here.
1352 */
1353 tu = alloc_trace_uprobe(UPROBE_EVENT_SYSTEM, "DUMMY_EVENT", 0,
1354 is_return);
1355
1356 if (IS_ERR(tu)) {
1357 pr_info("Failed to allocate trace_uprobe.(%d)\n",
1358 (int)PTR_ERR(tu));
1359 path_put(&path);
1360 return ERR_CAST(tu);
1361 }
1362
1363 tu->offset = offs;
1364 tu->path = path;
1365 tu->filename = kstrdup(name, GFP_KERNEL);
1366 init_trace_event_call(tu, &tu->tp.call);
1367
1368 if (set_print_fmt(&tu->tp, is_ret_probe(tu)) < 0) {
1369 ret = -ENOMEM;
1370 goto error;
1371 }
1372
1373 return &tu->tp.call;
1374error:
1375 free_trace_uprobe(tu);
1376 return ERR_PTR(ret);
1377}
1378
1379void destroy_local_trace_uprobe(struct trace_event_call *event_call)
1380{
1381 struct trace_uprobe *tu;
1382
1383 tu = container_of(event_call, struct trace_uprobe, tp.call);
1384
1385 kfree(tu->tp.call.print_fmt);
1386 tu->tp.call.print_fmt = NULL;
1387
1388 free_trace_uprobe(tu);
1389}
1390#endif /* CONFIG_PERF_EVENTS */
1391
1392/* Make a trace interface for controling probe points */
1393static __init int init_uprobe_trace(void)
1394{
1395 struct dentry *d_tracer;
1396
1397 d_tracer = tracing_init_dentry();
1398 if (IS_ERR(d_tracer))
1399 return 0;
1400
1401 trace_create_file("uprobe_events", 0644, d_tracer,
1402 NULL, &uprobe_events_ops);
1403 /* Profile interface */
1404 trace_create_file("uprobe_profile", 0444, d_tracer,
1405 NULL, &uprobe_profile_ops);
1406 return 0;
1407}
1408
1409fs_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);