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/cleanup.h>
12#include <linux/ctype.h>
13#include <linux/filter.h>
14#include <linux/module.h>
15#include <linux/namei.h>
16#include <linux/percpu.h>
17#include <linux/rculist.h>
18#include <linux/security.h>
19#include <linux/string.h>
20#include <linux/uaccess.h>
21#include <linux/uprobes.h>
22
23#include "trace.h"
24#include "trace_dynevent.h"
25#include "trace_probe.h"
26#include "trace_probe_tmpl.h"
27
28#define UPROBE_EVENT_SYSTEM "uprobes"
29
30struct uprobe_trace_entry_head {
31 struct trace_entry ent;
32 unsigned long vaddr[];
33};
34
35#define SIZEOF_TRACE_ENTRY(is_return) \
36 (sizeof(struct uprobe_trace_entry_head) + \
37 sizeof(unsigned long) * (is_return ? 2 : 1))
38
39#define DATAOF_TRACE_ENTRY(entry, is_return) \
40 ((void*)(entry) + SIZEOF_TRACE_ENTRY(is_return))
41
42static int trace_uprobe_create(const char *raw_command);
43static int trace_uprobe_show(struct seq_file *m, struct dyn_event *ev);
44static int trace_uprobe_release(struct dyn_event *ev);
45static bool trace_uprobe_is_busy(struct dyn_event *ev);
46static bool trace_uprobe_match(const char *system, const char *event,
47 int argc, const char **argv, struct dyn_event *ev);
48
49static struct dyn_event_operations trace_uprobe_ops = {
50 .create = trace_uprobe_create,
51 .show = trace_uprobe_show,
52 .is_busy = trace_uprobe_is_busy,
53 .free = trace_uprobe_release,
54 .match = trace_uprobe_match,
55};
56
57/*
58 * uprobe event core functions
59 */
60struct trace_uprobe {
61 struct dyn_event devent;
62 struct uprobe_consumer consumer;
63 struct path path;
64 char *filename;
65 struct uprobe *uprobe;
66 unsigned long offset;
67 unsigned long ref_ctr_offset;
68 unsigned long __percpu *nhits;
69 struct trace_probe tp;
70};
71
72static bool is_trace_uprobe(struct dyn_event *ev)
73{
74 return ev->ops == &trace_uprobe_ops;
75}
76
77static struct trace_uprobe *to_trace_uprobe(struct dyn_event *ev)
78{
79 return container_of(ev, struct trace_uprobe, devent);
80}
81
82/**
83 * for_each_trace_uprobe - iterate over the trace_uprobe list
84 * @pos: the struct trace_uprobe * for each entry
85 * @dpos: the struct dyn_event * to use as a loop cursor
86 */
87#define for_each_trace_uprobe(pos, dpos) \
88 for_each_dyn_event(dpos) \
89 if (is_trace_uprobe(dpos) && (pos = to_trace_uprobe(dpos)))
90
91static int register_uprobe_event(struct trace_uprobe *tu);
92static int unregister_uprobe_event(struct trace_uprobe *tu);
93
94static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs,
95 __u64 *data);
96static int uretprobe_dispatcher(struct uprobe_consumer *con,
97 unsigned long func, struct pt_regs *regs,
98 __u64 *data);
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(to: &ret, from: (void __force __user *) addr, n: 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(to: dest, from: vaddr, n: 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(dl: dest, ent: 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 = strscpy(dst, current->comm, maxlen);
160 else
161 ret = strncpy_from_user(dst, src, count: 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 } else
174 *(u32 *)dest = make_data_loc(0, (void *)dst - base);
175
176 return ret;
177}
178
179static nokprobe_inline int
180fetch_store_string_user(unsigned long addr, void *dest, void *base)
181{
182 return fetch_store_string(addr, dest, base);
183}
184
185/* Return the length of string -- including null terminal byte */
186static nokprobe_inline int
187fetch_store_strlen(unsigned long addr)
188{
189 int len;
190 void __user *vaddr = (void __force __user *) addr;
191
192 if (addr == FETCH_TOKEN_COMM)
193 len = strlen(current->comm) + 1;
194 else
195 len = strnlen_user(str: vaddr, MAX_STRING_SIZE);
196
197 return (len > MAX_STRING_SIZE) ? 0 : len;
198}
199
200static nokprobe_inline int
201fetch_store_strlen_user(unsigned long addr)
202{
203 return fetch_store_strlen(addr);
204}
205
206static unsigned long translate_user_vaddr(unsigned long file_offset)
207{
208 unsigned long base_addr;
209 struct uprobe_dispatch_data *udd;
210
211 udd = (void *) current->utask->vaddr;
212
213 base_addr = udd->bp_addr - udd->tu->offset;
214 return base_addr + file_offset;
215}
216
217/* Note that we don't verify it, since the code does not come from user space */
218static int
219process_fetch_insn(struct fetch_insn *code, void *rec, void *edata,
220 void *dest, void *base)
221{
222 struct pt_regs *regs = rec;
223 unsigned long val;
224 int ret;
225
226 /* 1st stage: get value from context */
227 switch (code->op) {
228 case FETCH_OP_REG:
229 val = regs_get_register(regs, offset: code->param);
230 break;
231 case FETCH_OP_STACK:
232 val = get_user_stack_nth(regs, n: code->param);
233 break;
234 case FETCH_OP_STACKP:
235 val = user_stack_pointer(regs);
236 break;
237 case FETCH_OP_RETVAL:
238 val = regs_return_value(regs);
239 break;
240 case FETCH_OP_COMM:
241 val = FETCH_TOKEN_COMM;
242 break;
243 case FETCH_OP_FOFFS:
244 val = translate_user_vaddr(file_offset: code->immediate);
245 break;
246 default:
247 ret = process_common_fetch_insn(code, val: &val);
248 if (ret < 0)
249 return ret;
250 }
251 code++;
252
253 return process_fetch_insn_bottom(code, val, dest, base);
254}
255NOKPROBE_SYMBOL(process_fetch_insn)
256
257static inline void init_trace_uprobe_filter(struct trace_uprobe_filter *filter)
258{
259 rwlock_init(&filter->rwlock);
260 filter->nr_systemwide = 0;
261 INIT_LIST_HEAD(list: &filter->perf_events);
262}
263
264static inline bool uprobe_filter_is_empty(struct trace_uprobe_filter *filter)
265{
266 return !filter->nr_systemwide && list_empty(head: &filter->perf_events);
267}
268
269static inline bool is_ret_probe(struct trace_uprobe *tu)
270{
271 return tu->consumer.ret_handler != NULL;
272}
273
274static bool trace_uprobe_is_busy(struct dyn_event *ev)
275{
276 struct trace_uprobe *tu = to_trace_uprobe(ev);
277
278 return trace_probe_is_enabled(tp: &tu->tp);
279}
280
281static bool trace_uprobe_match_command_head(struct trace_uprobe *tu,
282 int argc, const char **argv)
283{
284 char buf[MAX_ARGSTR_LEN + 1];
285 int len;
286
287 if (!argc)
288 return true;
289
290 len = strlen(tu->filename);
291 if (strncmp(tu->filename, argv[0], len) || argv[0][len] != ':')
292 return false;
293
294 if (tu->ref_ctr_offset == 0)
295 snprintf(buf, size: sizeof(buf), fmt: "0x%0*lx",
296 (int)(sizeof(void *) * 2), tu->offset);
297 else
298 snprintf(buf, size: sizeof(buf), fmt: "0x%0*lx(0x%lx)",
299 (int)(sizeof(void *) * 2), tu->offset,
300 tu->ref_ctr_offset);
301 if (strcmp(buf, &argv[0][len + 1]))
302 return false;
303
304 argc--; argv++;
305
306 return trace_probe_match_command_args(tp: &tu->tp, argc, argv);
307}
308
309static bool trace_uprobe_match(const char *system, const char *event,
310 int argc, const char **argv, struct dyn_event *ev)
311{
312 struct trace_uprobe *tu = to_trace_uprobe(ev);
313
314 return (event[0] == '\0' ||
315 strcmp(trace_probe_name(tp: &tu->tp), event) == 0) &&
316 (!system || strcmp(trace_probe_group_name(tp: &tu->tp), system) == 0) &&
317 trace_uprobe_match_command_head(tu, argc, argv);
318}
319
320static nokprobe_inline struct trace_uprobe *
321trace_uprobe_primary_from_call(struct trace_event_call *call)
322{
323 struct trace_probe *tp;
324
325 tp = trace_probe_primary_from_call(call);
326 if (WARN_ON_ONCE(!tp))
327 return NULL;
328
329 return container_of(tp, struct trace_uprobe, tp);
330}
331
332/*
333 * Allocate new trace_uprobe and initialize it (including uprobes).
334 */
335static struct trace_uprobe *
336alloc_trace_uprobe(const char *group, const char *event, int nargs, bool is_ret)
337{
338 struct trace_uprobe *tu;
339 int ret;
340
341 tu = kzalloc(struct_size(tu, tp.args, nargs), GFP_KERNEL);
342 if (!tu)
343 return ERR_PTR(error: -ENOMEM);
344
345 tu->nhits = alloc_percpu(unsigned long);
346 if (!tu->nhits) {
347 ret = -ENOMEM;
348 goto error;
349 }
350
351 ret = trace_probe_init(tp: &tu->tp, event, group, alloc_filter: true, nargs);
352 if (ret < 0)
353 goto error;
354
355 dyn_event_init(ev: &tu->devent, ops: &trace_uprobe_ops);
356 tu->consumer.handler = uprobe_dispatcher;
357 if (is_ret)
358 tu->consumer.ret_handler = uretprobe_dispatcher;
359 init_trace_uprobe_filter(filter: tu->tp.event->filter);
360 return tu;
361
362error:
363 free_percpu(pdata: tu->nhits);
364 kfree(objp: tu);
365
366 return ERR_PTR(error: ret);
367}
368
369static void free_trace_uprobe(struct trace_uprobe *tu)
370{
371 if (!tu)
372 return;
373
374 path_put(&tu->path);
375 trace_probe_cleanup(tp: &tu->tp);
376 kfree(objp: tu->filename);
377 free_percpu(pdata: tu->nhits);
378 kfree(objp: tu);
379}
380
381static struct trace_uprobe *find_probe_event(const char *event, const char *group)
382{
383 struct dyn_event *pos;
384 struct trace_uprobe *tu;
385
386 for_each_trace_uprobe(tu, pos)
387 if (strcmp(trace_probe_name(tp: &tu->tp), event) == 0 &&
388 strcmp(trace_probe_group_name(tp: &tu->tp), group) == 0)
389 return tu;
390
391 return NULL;
392}
393
394/* Unregister a trace_uprobe and probe_event */
395static int unregister_trace_uprobe(struct trace_uprobe *tu)
396{
397 int ret;
398
399 if (trace_probe_has_sibling(tp: &tu->tp))
400 goto unreg;
401
402 /* If there's a reference to the dynamic event */
403 if (trace_event_dyn_busy(call: trace_probe_event_call(tp: &tu->tp)))
404 return -EBUSY;
405
406 ret = unregister_uprobe_event(tu);
407 if (ret)
408 return ret;
409
410unreg:
411 dyn_event_remove(ev: &tu->devent);
412 trace_probe_unlink(tp: &tu->tp);
413 free_trace_uprobe(tu);
414 return 0;
415}
416
417static bool trace_uprobe_has_same_uprobe(struct trace_uprobe *orig,
418 struct trace_uprobe *comp)
419{
420 struct trace_probe_event *tpe = orig->tp.event;
421 struct inode *comp_inode = d_real_inode(dentry: comp->path.dentry);
422 int i;
423
424 list_for_each_entry(orig, &tpe->probes, tp.list) {
425 if (comp_inode != d_real_inode(dentry: orig->path.dentry) ||
426 comp->offset != orig->offset)
427 continue;
428
429 /*
430 * trace_probe_compare_arg_type() ensured that nr_args and
431 * each argument name and type are same. Let's compare comm.
432 */
433 for (i = 0; i < orig->tp.nr_args; i++) {
434 if (strcmp(orig->tp.args[i].comm,
435 comp->tp.args[i].comm))
436 break;
437 }
438
439 if (i == orig->tp.nr_args)
440 return true;
441 }
442
443 return false;
444}
445
446static int append_trace_uprobe(struct trace_uprobe *tu, struct trace_uprobe *to)
447{
448 int ret;
449
450 ret = trace_probe_compare_arg_type(a: &tu->tp, b: &to->tp);
451 if (ret) {
452 /* Note that argument starts index = 2 */
453 trace_probe_log_set_index(index: ret + 1);
454 trace_probe_log_err(0, DIFF_ARG_TYPE);
455 return -EEXIST;
456 }
457 if (trace_uprobe_has_same_uprobe(orig: to, comp: tu)) {
458 trace_probe_log_set_index(index: 0);
459 trace_probe_log_err(0, SAME_PROBE);
460 return -EEXIST;
461 }
462
463 /* Append to existing event */
464 ret = trace_probe_append(tp: &tu->tp, to: &to->tp);
465 if (!ret)
466 dyn_event_add(ev: &tu->devent, call: trace_probe_event_call(tp: &tu->tp));
467
468 return ret;
469}
470
471/*
472 * Uprobe with multiple reference counter is not allowed. i.e.
473 * If inode and offset matches, reference counter offset *must*
474 * match as well. Though, there is one exception: If user is
475 * replacing old trace_uprobe with new one(same group/event),
476 * then we allow same uprobe with new reference counter as far
477 * as the new one does not conflict with any other existing
478 * ones.
479 */
480static int validate_ref_ctr_offset(struct trace_uprobe *new)
481{
482 struct dyn_event *pos;
483 struct trace_uprobe *tmp;
484 struct inode *new_inode = d_real_inode(dentry: new->path.dentry);
485
486 for_each_trace_uprobe(tmp, pos) {
487 if (new_inode == d_real_inode(dentry: tmp->path.dentry) &&
488 new->offset == tmp->offset &&
489 new->ref_ctr_offset != tmp->ref_ctr_offset) {
490 pr_warn("Reference counter offset mismatch.");
491 return -EINVAL;
492 }
493 }
494 return 0;
495}
496
497/* Register a trace_uprobe and probe_event */
498static int register_trace_uprobe(struct trace_uprobe *tu)
499{
500 struct trace_uprobe *old_tu;
501 int ret;
502
503 guard(mutex)(T: &event_mutex);
504
505 ret = validate_ref_ctr_offset(new: tu);
506 if (ret)
507 return ret;
508
509 /* register as an event */
510 old_tu = find_probe_event(event: trace_probe_name(tp: &tu->tp),
511 group: trace_probe_group_name(tp: &tu->tp));
512 if (old_tu) {
513 if (is_ret_probe(tu) != is_ret_probe(tu: old_tu)) {
514 trace_probe_log_set_index(index: 0);
515 trace_probe_log_err(0, DIFF_PROBE_TYPE);
516 return -EEXIST;
517 }
518 return append_trace_uprobe(tu, to: old_tu);
519 }
520
521 ret = register_uprobe_event(tu);
522 if (ret) {
523 if (ret == -EEXIST) {
524 trace_probe_log_set_index(index: 0);
525 trace_probe_log_err(0, EVENT_EXIST);
526 } else
527 pr_warn("Failed to register probe event(%d)\n", ret);
528 return ret;
529 }
530
531 dyn_event_add(ev: &tu->devent, call: trace_probe_event_call(tp: &tu->tp));
532
533 return ret;
534}
535
536/*
537 * Argument syntax:
538 * - Add uprobe: p|r[:[GRP/][EVENT]] PATH:OFFSET[%return][(REF)] [FETCHARGS]
539 */
540static int __trace_uprobe_create(int argc, const char **argv)
541{
542 const char *event = NULL, *group = UPROBE_EVENT_SYSTEM;
543 char *arg, *filename, *rctr, *rctr_end, *tmp;
544 unsigned long offset, ref_ctr_offset;
545 char *gbuf __free(kfree) = NULL;
546 char *buf __free(kfree) = NULL;
547 enum probe_print_type ptype;
548 struct trace_uprobe *tu;
549 bool is_return = false;
550 struct path path;
551 int i, ret;
552
553 ref_ctr_offset = 0;
554
555 switch (argv[0][0]) {
556 case 'r':
557 is_return = true;
558 break;
559 case 'p':
560 break;
561 default:
562 return -ECANCELED;
563 }
564
565 if (argc < 2)
566 return -ECANCELED;
567
568 trace_probe_log_init(subsystem: "trace_uprobe", argc, argv);
569
570 if (argc - 2 > MAX_TRACE_ARGS) {
571 trace_probe_log_set_index(index: 2);
572 trace_probe_log_err(0, TOO_MANY_ARGS);
573 return -E2BIG;
574 }
575
576 if (argv[0][1] == ':')
577 event = &argv[0][2];
578
579 if (!strchr(argv[1], '/'))
580 return -ECANCELED;
581
582 filename = kstrdup(s: argv[1], GFP_KERNEL);
583 if (!filename)
584 return -ENOMEM;
585
586 /* Find the last occurrence, in case the path contains ':' too. */
587 arg = strrchr(filename, ':');
588 if (!arg || !isdigit(c: arg[1])) {
589 kfree(objp: filename);
590 return -ECANCELED;
591 }
592
593 trace_probe_log_set_index(index: 1); /* filename is the 2nd argument */
594
595 *arg++ = '\0';
596 ret = kern_path(filename, LOOKUP_FOLLOW, &path);
597 if (ret) {
598 trace_probe_log_err(0, FILE_NOT_FOUND);
599 kfree(objp: filename);
600 trace_probe_log_clear();
601 return ret;
602 }
603 if (!d_is_reg(dentry: path.dentry)) {
604 trace_probe_log_err(0, NO_REGULAR_FILE);
605 ret = -EINVAL;
606 goto fail_address_parse;
607 }
608
609 /* Parse reference counter offset if specified. */
610 rctr = strchr(arg, '(');
611 if (rctr) {
612 rctr_end = strchr(rctr, ')');
613 if (!rctr_end) {
614 ret = -EINVAL;
615 rctr_end = rctr + strlen(rctr);
616 trace_probe_log_err(rctr_end - filename,
617 REFCNT_OPEN_BRACE);
618 goto fail_address_parse;
619 } else if (rctr_end[1] != '\0') {
620 ret = -EINVAL;
621 trace_probe_log_err(rctr_end + 1 - filename,
622 BAD_REFCNT_SUFFIX);
623 goto fail_address_parse;
624 }
625
626 *rctr++ = '\0';
627 *rctr_end = '\0';
628 ret = kstrtoul(s: rctr, base: 0, res: &ref_ctr_offset);
629 if (ret) {
630 trace_probe_log_err(rctr - filename, BAD_REFCNT);
631 goto fail_address_parse;
632 }
633 }
634
635 /* Check if there is %return suffix */
636 tmp = strchr(arg, '%');
637 if (tmp) {
638 if (!strcmp(tmp, "%return")) {
639 *tmp = '\0';
640 is_return = true;
641 } else {
642 trace_probe_log_err(tmp - filename, BAD_ADDR_SUFFIX);
643 ret = -EINVAL;
644 goto fail_address_parse;
645 }
646 }
647
648 /* Parse uprobe offset. */
649 ret = kstrtoul(s: arg, base: 0, res: &offset);
650 if (ret) {
651 trace_probe_log_err(arg - filename, BAD_UPROBE_OFFS);
652 goto fail_address_parse;
653 }
654
655 /* setup a probe */
656 trace_probe_log_set_index(index: 0);
657 if (event) {
658 gbuf = kmalloc(MAX_EVENT_NAME_LEN, GFP_KERNEL);
659 if (!gbuf)
660 goto fail_mem;
661
662 ret = traceprobe_parse_event_name(pevent: &event, pgroup: &group, buf: gbuf,
663 offset: event - argv[0]);
664 if (ret)
665 goto fail_address_parse;
666 }
667
668 if (!event) {
669 char *tail;
670 char *ptr;
671
672 tail = kstrdup(s: kbasename(path: filename), GFP_KERNEL);
673 if (!tail)
674 goto fail_mem;
675
676 ptr = strpbrk(tail, ".-_");
677 if (ptr)
678 *ptr = '\0';
679
680 buf = kmalloc(MAX_EVENT_NAME_LEN, GFP_KERNEL);
681 if (!buf)
682 goto fail_mem;
683 snprintf(buf, MAX_EVENT_NAME_LEN, fmt: "%c_%s_0x%lx", 'p', tail, offset);
684 event = buf;
685 kfree(objp: tail);
686 }
687
688 argc -= 2;
689 argv += 2;
690
691 tu = alloc_trace_uprobe(group, event, nargs: argc, is_ret: is_return);
692 if (IS_ERR(ptr: tu)) {
693 ret = PTR_ERR(ptr: tu);
694 /* This must return -ENOMEM otherwise there is a bug */
695 WARN_ON_ONCE(ret != -ENOMEM);
696 goto fail_address_parse;
697 }
698 tu->offset = offset;
699 tu->ref_ctr_offset = ref_ctr_offset;
700 tu->path = path;
701 tu->filename = filename;
702
703 /* parse arguments */
704 for (i = 0; i < argc; i++) {
705 struct traceprobe_parse_context *ctx __free(traceprobe_parse_context)
706 = kzalloc(sizeof(*ctx), GFP_KERNEL);
707
708 if (!ctx) {
709 ret = -ENOMEM;
710 goto error;
711 }
712 ctx->flags = (is_return ? TPARG_FL_RETURN : 0) | TPARG_FL_USER;
713 trace_probe_log_set_index(index: i + 2);
714 ret = traceprobe_parse_probe_arg(tp: &tu->tp, i, argv: argv[i], ctx);
715 if (ret)
716 goto error;
717 }
718
719 ptype = is_ret_probe(tu) ? PROBE_PRINT_RETURN : PROBE_PRINT_NORMAL;
720 ret = traceprobe_set_print_fmt(tp: &tu->tp, ptype);
721 if (ret < 0)
722 goto error;
723
724 ret = register_trace_uprobe(tu);
725 if (!ret)
726 goto out;
727
728error:
729 free_trace_uprobe(tu);
730out:
731 trace_probe_log_clear();
732 return ret;
733
734fail_mem:
735 ret = -ENOMEM;
736
737fail_address_parse:
738 trace_probe_log_clear();
739 path_put(&path);
740 kfree(objp: filename);
741
742 return ret;
743}
744
745int trace_uprobe_create(const char *raw_command)
746{
747 return trace_probe_create(raw_command, createfn: __trace_uprobe_create);
748}
749
750static int create_or_delete_trace_uprobe(const char *raw_command)
751{
752 int ret;
753
754 if (raw_command[0] == '-')
755 return dyn_event_release(raw_command, type: &trace_uprobe_ops);
756
757 ret = dyn_event_create(raw_command, type: &trace_uprobe_ops);
758 return ret == -ECANCELED ? -EINVAL : ret;
759}
760
761static int trace_uprobe_release(struct dyn_event *ev)
762{
763 struct trace_uprobe *tu = to_trace_uprobe(ev);
764
765 return unregister_trace_uprobe(tu);
766}
767
768/* Probes listing interfaces */
769static int trace_uprobe_show(struct seq_file *m, struct dyn_event *ev)
770{
771 struct trace_uprobe *tu = to_trace_uprobe(ev);
772 char c = is_ret_probe(tu) ? 'r' : 'p';
773 int i;
774
775 seq_printf(m, fmt: "%c:%s/%s %s:0x%0*lx", c, trace_probe_group_name(tp: &tu->tp),
776 trace_probe_name(tp: &tu->tp), tu->filename,
777 (int)(sizeof(void *) * 2), tu->offset);
778
779 if (tu->ref_ctr_offset)
780 seq_printf(m, fmt: "(0x%lx)", tu->ref_ctr_offset);
781
782 for (i = 0; i < tu->tp.nr_args; i++)
783 seq_printf(m, fmt: " %s=%s", tu->tp.args[i].name, tu->tp.args[i].comm);
784
785 seq_putc(m, c: '\n');
786 return 0;
787}
788
789static int probes_seq_show(struct seq_file *m, void *v)
790{
791 struct dyn_event *ev = v;
792
793 if (!is_trace_uprobe(ev))
794 return 0;
795
796 return trace_uprobe_show(m, ev);
797}
798
799static const struct seq_operations probes_seq_op = {
800 .start = dyn_event_seq_start,
801 .next = dyn_event_seq_next,
802 .stop = dyn_event_seq_stop,
803 .show = probes_seq_show
804};
805
806static int probes_open(struct inode *inode, struct file *file)
807{
808 int ret;
809
810 ret = security_locked_down(what: LOCKDOWN_TRACEFS);
811 if (ret)
812 return ret;
813
814 if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
815 ret = dyn_events_release_all(type: &trace_uprobe_ops);
816 if (ret)
817 return ret;
818 }
819
820 return seq_open(file, &probes_seq_op);
821}
822
823static ssize_t probes_write(struct file *file, const char __user *buffer,
824 size_t count, loff_t *ppos)
825{
826 return trace_parse_run_command(file, buffer, count, ppos,
827 createfn: create_or_delete_trace_uprobe);
828}
829
830static const struct file_operations uprobe_events_ops = {
831 .owner = THIS_MODULE,
832 .open = probes_open,
833 .read = seq_read,
834 .llseek = seq_lseek,
835 .release = seq_release,
836 .write = probes_write,
837};
838
839/* Probes profiling interfaces */
840static int probes_profile_seq_show(struct seq_file *m, void *v)
841{
842 struct dyn_event *ev = v;
843 struct trace_uprobe *tu;
844 unsigned long nhits;
845 int cpu;
846
847 if (!is_trace_uprobe(ev))
848 return 0;
849
850 tu = to_trace_uprobe(ev);
851
852 nhits = 0;
853 for_each_possible_cpu(cpu) {
854 nhits += per_cpu(*tu->nhits, cpu);
855 }
856
857 seq_printf(m, fmt: " %s %-44s %15lu\n", tu->filename,
858 trace_probe_name(tp: &tu->tp), nhits);
859 return 0;
860}
861
862static const struct seq_operations profile_seq_op = {
863 .start = dyn_event_seq_start,
864 .next = dyn_event_seq_next,
865 .stop = dyn_event_seq_stop,
866 .show = probes_profile_seq_show
867};
868
869static int profile_open(struct inode *inode, struct file *file)
870{
871 int ret;
872
873 ret = security_locked_down(what: LOCKDOWN_TRACEFS);
874 if (ret)
875 return ret;
876
877 return seq_open(file, &profile_seq_op);
878}
879
880static const struct file_operations uprobe_profile_ops = {
881 .owner = THIS_MODULE,
882 .open = profile_open,
883 .read = seq_read,
884 .llseek = seq_lseek,
885 .release = seq_release,
886};
887
888struct uprobe_cpu_buffer {
889 struct mutex mutex;
890 void *buf;
891 int dsize;
892};
893static struct uprobe_cpu_buffer __percpu *uprobe_cpu_buffer;
894static int uprobe_buffer_refcnt;
895#define MAX_UCB_BUFFER_SIZE PAGE_SIZE
896
897static int uprobe_buffer_init(void)
898{
899 int cpu, err_cpu;
900
901 uprobe_cpu_buffer = alloc_percpu(struct uprobe_cpu_buffer);
902 if (uprobe_cpu_buffer == NULL)
903 return -ENOMEM;
904
905 for_each_possible_cpu(cpu) {
906 struct page *p = alloc_pages_node(cpu_to_node(cpu),
907 GFP_KERNEL, 0);
908 if (p == NULL) {
909 err_cpu = cpu;
910 goto err;
911 }
912 per_cpu_ptr(uprobe_cpu_buffer, cpu)->buf = page_address(p);
913 mutex_init(&per_cpu_ptr(uprobe_cpu_buffer, cpu)->mutex);
914 }
915
916 return 0;
917
918err:
919 for_each_possible_cpu(cpu) {
920 if (cpu == err_cpu)
921 break;
922 free_page((unsigned long)per_cpu_ptr(uprobe_cpu_buffer, cpu)->buf);
923 }
924
925 free_percpu(pdata: uprobe_cpu_buffer);
926 return -ENOMEM;
927}
928
929static int uprobe_buffer_enable(void)
930{
931 int ret = 0;
932
933 BUG_ON(!mutex_is_locked(&event_mutex));
934
935 if (uprobe_buffer_refcnt++ == 0) {
936 ret = uprobe_buffer_init();
937 if (ret < 0)
938 uprobe_buffer_refcnt--;
939 }
940
941 return ret;
942}
943
944static void uprobe_buffer_disable(void)
945{
946 int cpu;
947
948 BUG_ON(!mutex_is_locked(&event_mutex));
949
950 if (--uprobe_buffer_refcnt == 0) {
951 for_each_possible_cpu(cpu)
952 free_page((unsigned long)per_cpu_ptr(uprobe_cpu_buffer,
953 cpu)->buf);
954
955 free_percpu(pdata: uprobe_cpu_buffer);
956 uprobe_cpu_buffer = NULL;
957 }
958}
959
960static struct uprobe_cpu_buffer *uprobe_buffer_get(void)
961{
962 struct uprobe_cpu_buffer *ucb;
963 int cpu;
964
965 cpu = raw_smp_processor_id();
966 ucb = per_cpu_ptr(uprobe_cpu_buffer, cpu);
967
968 /*
969 * Use per-cpu buffers for fastest access, but we might migrate
970 * so the mutex makes sure we have sole access to it.
971 */
972 mutex_lock(lock: &ucb->mutex);
973
974 return ucb;
975}
976
977static void uprobe_buffer_put(struct uprobe_cpu_buffer *ucb)
978{
979 if (!ucb)
980 return;
981 mutex_unlock(lock: &ucb->mutex);
982}
983
984static struct uprobe_cpu_buffer *prepare_uprobe_buffer(struct trace_uprobe *tu,
985 struct pt_regs *regs,
986 struct uprobe_cpu_buffer **ucbp)
987{
988 struct uprobe_cpu_buffer *ucb;
989 int dsize, esize;
990
991 if (*ucbp)
992 return *ucbp;
993
994 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
995 dsize = __get_data_size(tp: &tu->tp, regs, NULL);
996
997 ucb = uprobe_buffer_get();
998 ucb->dsize = tu->tp.size + dsize;
999
1000 if (WARN_ON_ONCE(ucb->dsize > MAX_UCB_BUFFER_SIZE)) {
1001 ucb->dsize = MAX_UCB_BUFFER_SIZE;
1002 dsize = MAX_UCB_BUFFER_SIZE - tu->tp.size;
1003 }
1004
1005 store_trace_args(data: ucb->buf, tp: &tu->tp, rec: regs, NULL, header_size: esize, maxlen: dsize);
1006
1007 *ucbp = ucb;
1008 return ucb;
1009}
1010
1011static void __uprobe_trace_func(struct trace_uprobe *tu,
1012 unsigned long func, struct pt_regs *regs,
1013 struct uprobe_cpu_buffer *ucb,
1014 struct trace_event_file *trace_file)
1015{
1016 struct uprobe_trace_entry_head *entry;
1017 struct trace_event_buffer fbuffer;
1018 void *data;
1019 int size, esize;
1020 struct trace_event_call *call = trace_probe_event_call(tp: &tu->tp);
1021
1022 WARN_ON(call != trace_file->event_call);
1023
1024 if (trace_trigger_soft_disabled(file: trace_file))
1025 return;
1026
1027 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
1028 size = esize + ucb->dsize;
1029 entry = trace_event_buffer_reserve(fbuffer: &fbuffer, trace_file, len: size);
1030 if (!entry)
1031 return;
1032
1033 if (is_ret_probe(tu)) {
1034 entry->vaddr[0] = func;
1035 entry->vaddr[1] = instruction_pointer(regs);
1036 data = DATAOF_TRACE_ENTRY(entry, true);
1037 } else {
1038 entry->vaddr[0] = instruction_pointer(regs);
1039 data = DATAOF_TRACE_ENTRY(entry, false);
1040 }
1041
1042 memcpy(to: data, from: ucb->buf, len: ucb->dsize);
1043
1044 trace_event_buffer_commit(fbuffer: &fbuffer);
1045}
1046
1047/* uprobe handler */
1048static int uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs,
1049 struct uprobe_cpu_buffer **ucbp)
1050{
1051 struct event_file_link *link;
1052 struct uprobe_cpu_buffer *ucb;
1053
1054 if (is_ret_probe(tu))
1055 return 0;
1056
1057 ucb = prepare_uprobe_buffer(tu, regs, ucbp);
1058
1059 rcu_read_lock();
1060 trace_probe_for_each_link_rcu(link, &tu->tp)
1061 __uprobe_trace_func(tu, func: 0, regs, ucb, trace_file: link->file);
1062 rcu_read_unlock();
1063
1064 return 0;
1065}
1066
1067static void uretprobe_trace_func(struct trace_uprobe *tu, unsigned long func,
1068 struct pt_regs *regs,
1069 struct uprobe_cpu_buffer **ucbp)
1070{
1071 struct event_file_link *link;
1072 struct uprobe_cpu_buffer *ucb;
1073
1074 ucb = prepare_uprobe_buffer(tu, regs, ucbp);
1075
1076 rcu_read_lock();
1077 trace_probe_for_each_link_rcu(link, &tu->tp)
1078 __uprobe_trace_func(tu, func, regs, ucb, trace_file: link->file);
1079 rcu_read_unlock();
1080}
1081
1082/* Event entry printers */
1083static enum print_line_t
1084print_uprobe_event(struct trace_iterator *iter, int flags, struct trace_event *event)
1085{
1086 struct uprobe_trace_entry_head *entry;
1087 struct trace_seq *s = &iter->seq;
1088 struct trace_uprobe *tu;
1089 u8 *data;
1090
1091 entry = (struct uprobe_trace_entry_head *)iter->ent;
1092 tu = trace_uprobe_primary_from_call(
1093 container_of(event, struct trace_event_call, event));
1094 if (unlikely(!tu))
1095 goto out;
1096
1097 if (is_ret_probe(tu)) {
1098 trace_seq_printf(s, fmt: "%s: (0x%lx <- 0x%lx)",
1099 trace_probe_name(tp: &tu->tp),
1100 entry->vaddr[1], entry->vaddr[0]);
1101 data = DATAOF_TRACE_ENTRY(entry, true);
1102 } else {
1103 trace_seq_printf(s, fmt: "%s: (0x%lx)",
1104 trace_probe_name(tp: &tu->tp),
1105 entry->vaddr[0]);
1106 data = DATAOF_TRACE_ENTRY(entry, false);
1107 }
1108
1109 if (trace_probe_print_args(s, args: tu->tp.args, nr_args: tu->tp.nr_args, data, field: entry) < 0)
1110 goto out;
1111
1112 trace_seq_putc(s, c: '\n');
1113
1114 out:
1115 return trace_handle_return(s);
1116}
1117
1118typedef bool (*filter_func_t)(struct uprobe_consumer *self, struct mm_struct *mm);
1119
1120static int trace_uprobe_enable(struct trace_uprobe *tu, filter_func_t filter)
1121{
1122 struct inode *inode = d_real_inode(dentry: tu->path.dentry);
1123 struct uprobe *uprobe;
1124
1125 tu->consumer.filter = filter;
1126 uprobe = uprobe_register(inode, offset: tu->offset, ref_ctr_offset: tu->ref_ctr_offset, uc: &tu->consumer);
1127 if (IS_ERR(ptr: uprobe))
1128 return PTR_ERR(ptr: uprobe);
1129
1130 tu->uprobe = uprobe;
1131 return 0;
1132}
1133
1134static void __probe_event_disable(struct trace_probe *tp)
1135{
1136 struct trace_uprobe *tu;
1137 bool sync = false;
1138
1139 tu = container_of(tp, struct trace_uprobe, tp);
1140 WARN_ON(!uprobe_filter_is_empty(tu->tp.event->filter));
1141
1142 list_for_each_entry(tu, trace_probe_probe_list(tp), tp.list) {
1143 if (!tu->uprobe)
1144 continue;
1145
1146 uprobe_unregister_nosync(uprobe: tu->uprobe, uc: &tu->consumer);
1147 sync = true;
1148 tu->uprobe = NULL;
1149 }
1150 if (sync)
1151 uprobe_unregister_sync();
1152}
1153
1154static int probe_event_enable(struct trace_event_call *call,
1155 struct trace_event_file *file, filter_func_t filter)
1156{
1157 struct trace_probe *tp;
1158 struct trace_uprobe *tu;
1159 bool enabled;
1160 int ret;
1161
1162 tp = trace_probe_primary_from_call(call);
1163 if (WARN_ON_ONCE(!tp))
1164 return -ENODEV;
1165 enabled = trace_probe_is_enabled(tp);
1166
1167 /* This may also change "enabled" state */
1168 if (file) {
1169 if (trace_probe_test_flag(tp, TP_FLAG_PROFILE))
1170 return -EINTR;
1171
1172 ret = trace_probe_add_file(tp, file);
1173 if (ret < 0)
1174 return ret;
1175 } else {
1176 if (trace_probe_test_flag(tp, TP_FLAG_TRACE))
1177 return -EINTR;
1178
1179 trace_probe_set_flag(tp, TP_FLAG_PROFILE);
1180 }
1181
1182 tu = container_of(tp, struct trace_uprobe, tp);
1183 WARN_ON(!uprobe_filter_is_empty(tu->tp.event->filter));
1184
1185 if (enabled)
1186 return 0;
1187
1188 ret = uprobe_buffer_enable();
1189 if (ret)
1190 goto err_flags;
1191
1192 list_for_each_entry(tu, trace_probe_probe_list(tp), tp.list) {
1193 ret = trace_uprobe_enable(tu, filter);
1194 if (ret) {
1195 __probe_event_disable(tp);
1196 goto err_buffer;
1197 }
1198 }
1199
1200 return 0;
1201
1202 err_buffer:
1203 uprobe_buffer_disable();
1204
1205 err_flags:
1206 if (file)
1207 trace_probe_remove_file(tp, file);
1208 else
1209 trace_probe_clear_flag(tp, TP_FLAG_PROFILE);
1210
1211 return ret;
1212}
1213
1214static void probe_event_disable(struct trace_event_call *call,
1215 struct trace_event_file *file)
1216{
1217 struct trace_probe *tp;
1218
1219 tp = trace_probe_primary_from_call(call);
1220 if (WARN_ON_ONCE(!tp))
1221 return;
1222
1223 if (!trace_probe_is_enabled(tp))
1224 return;
1225
1226 if (file) {
1227 if (trace_probe_remove_file(tp, file) < 0)
1228 return;
1229
1230 if (trace_probe_is_enabled(tp))
1231 return;
1232 } else
1233 trace_probe_clear_flag(tp, TP_FLAG_PROFILE);
1234
1235 __probe_event_disable(tp);
1236 uprobe_buffer_disable();
1237}
1238
1239static int uprobe_event_define_fields(struct trace_event_call *event_call)
1240{
1241 int ret, size;
1242 struct uprobe_trace_entry_head field;
1243 struct trace_uprobe *tu;
1244
1245 tu = trace_uprobe_primary_from_call(call: event_call);
1246 if (unlikely(!tu))
1247 return -ENODEV;
1248
1249 if (is_ret_probe(tu)) {
1250 DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_FUNC, 0);
1251 DEFINE_FIELD(unsigned long, vaddr[1], FIELD_STRING_RETIP, 0);
1252 size = SIZEOF_TRACE_ENTRY(true);
1253 } else {
1254 DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_IP, 0);
1255 size = SIZEOF_TRACE_ENTRY(false);
1256 }
1257
1258 return traceprobe_define_arg_fields(event_call, offset: size, tp: &tu->tp);
1259}
1260
1261#ifdef CONFIG_PERF_EVENTS
1262static bool
1263__uprobe_perf_filter(struct trace_uprobe_filter *filter, struct mm_struct *mm)
1264{
1265 struct perf_event *event;
1266
1267 list_for_each_entry(event, &filter->perf_events, hw.tp_list) {
1268 if (event->hw.target->mm == mm)
1269 return true;
1270 }
1271
1272 return false;
1273}
1274
1275static inline bool
1276trace_uprobe_filter_event(struct trace_uprobe_filter *filter,
1277 struct perf_event *event)
1278{
1279 return __uprobe_perf_filter(filter, mm: event->hw.target->mm);
1280}
1281
1282static bool trace_uprobe_filter_remove(struct trace_uprobe_filter *filter,
1283 struct perf_event *event)
1284{
1285 bool done;
1286
1287 write_lock(&filter->rwlock);
1288 if (event->hw.target) {
1289 list_del(entry: &event->hw.tp_list);
1290 done = filter->nr_systemwide ||
1291 (event->hw.target->flags & PF_EXITING) ||
1292 trace_uprobe_filter_event(filter, event);
1293 } else {
1294 filter->nr_systemwide--;
1295 done = filter->nr_systemwide;
1296 }
1297 write_unlock(&filter->rwlock);
1298
1299 return done;
1300}
1301
1302/* This returns true if the filter always covers target mm */
1303static bool trace_uprobe_filter_add(struct trace_uprobe_filter *filter,
1304 struct perf_event *event)
1305{
1306 bool done;
1307
1308 write_lock(&filter->rwlock);
1309 if (event->hw.target) {
1310 /*
1311 * event->parent != NULL means copy_process(), we can avoid
1312 * uprobe_apply(). current->mm must be probed and we can rely
1313 * on dup_mmap() which preserves the already installed bp's.
1314 *
1315 * attr.enable_on_exec means that exec/mmap will install the
1316 * breakpoints we need.
1317 */
1318 done = filter->nr_systemwide ||
1319 event->parent || event->attr.enable_on_exec ||
1320 trace_uprobe_filter_event(filter, event);
1321 list_add(new: &event->hw.tp_list, head: &filter->perf_events);
1322 } else {
1323 done = filter->nr_systemwide;
1324 filter->nr_systemwide++;
1325 }
1326 write_unlock(&filter->rwlock);
1327
1328 return done;
1329}
1330
1331static int uprobe_perf_close(struct trace_event_call *call,
1332 struct perf_event *event)
1333{
1334 struct trace_probe *tp;
1335 struct trace_uprobe *tu;
1336 int ret = 0;
1337
1338 tp = trace_probe_primary_from_call(call);
1339 if (WARN_ON_ONCE(!tp))
1340 return -ENODEV;
1341
1342 tu = container_of(tp, struct trace_uprobe, tp);
1343 if (trace_uprobe_filter_remove(filter: tu->tp.event->filter, event))
1344 return 0;
1345
1346 list_for_each_entry(tu, trace_probe_probe_list(tp), tp.list) {
1347 ret = uprobe_apply(uprobe: tu->uprobe, uc: &tu->consumer, false);
1348 if (ret)
1349 break;
1350 }
1351
1352 return ret;
1353}
1354
1355static int uprobe_perf_open(struct trace_event_call *call,
1356 struct perf_event *event)
1357{
1358 struct trace_probe *tp;
1359 struct trace_uprobe *tu;
1360 int err = 0;
1361
1362 tp = trace_probe_primary_from_call(call);
1363 if (WARN_ON_ONCE(!tp))
1364 return -ENODEV;
1365
1366 tu = container_of(tp, struct trace_uprobe, tp);
1367 if (trace_uprobe_filter_add(filter: tu->tp.event->filter, event))
1368 return 0;
1369
1370 list_for_each_entry(tu, trace_probe_probe_list(tp), tp.list) {
1371 err = uprobe_apply(uprobe: tu->uprobe, uc: &tu->consumer, true);
1372 if (err) {
1373 uprobe_perf_close(call, event);
1374 break;
1375 }
1376 }
1377
1378 return err;
1379}
1380
1381static bool uprobe_perf_filter(struct uprobe_consumer *uc, struct mm_struct *mm)
1382{
1383 struct trace_uprobe_filter *filter;
1384 struct trace_uprobe *tu;
1385 int ret;
1386
1387 tu = container_of(uc, struct trace_uprobe, consumer);
1388 filter = tu->tp.event->filter;
1389
1390 /*
1391 * speculative short-circuiting check to avoid unnecessarily taking
1392 * filter->rwlock below, if the uprobe has system-wide consumer
1393 */
1394 if (READ_ONCE(filter->nr_systemwide))
1395 return true;
1396
1397 read_lock(&filter->rwlock);
1398 ret = __uprobe_perf_filter(filter, mm);
1399 read_unlock(&filter->rwlock);
1400
1401 return ret;
1402}
1403
1404static void __uprobe_perf_func(struct trace_uprobe *tu,
1405 unsigned long func, struct pt_regs *regs,
1406 struct uprobe_cpu_buffer **ucbp)
1407{
1408 struct trace_event_call *call = trace_probe_event_call(tp: &tu->tp);
1409 struct uprobe_trace_entry_head *entry;
1410 struct uprobe_cpu_buffer *ucb;
1411 struct hlist_head *head;
1412 void *data;
1413 int size, esize;
1414 int rctx;
1415
1416#ifdef CONFIG_BPF_EVENTS
1417 if (bpf_prog_array_valid(call)) {
1418 const struct bpf_prog_array *array;
1419 u32 ret;
1420
1421 rcu_read_lock_trace();
1422 array = rcu_dereference_check(call->prog_array, rcu_read_lock_trace_held());
1423 ret = bpf_prog_run_array_uprobe(array, regs, bpf_prog_run);
1424 rcu_read_unlock_trace();
1425 if (!ret)
1426 return;
1427 }
1428#endif /* CONFIG_BPF_EVENTS */
1429
1430 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
1431
1432 ucb = prepare_uprobe_buffer(tu, regs, ucbp);
1433 size = esize + ucb->dsize;
1434 size = ALIGN(size + sizeof(u32), sizeof(u64)) - sizeof(u32);
1435 if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, "profile buffer not large enough"))
1436 return;
1437
1438 preempt_disable();
1439 head = this_cpu_ptr(call->perf_events);
1440 if (hlist_empty(h: head))
1441 goto out;
1442
1443 entry = perf_trace_buf_alloc(size, NULL, rctxp: &rctx);
1444 if (!entry)
1445 goto out;
1446
1447 if (is_ret_probe(tu)) {
1448 entry->vaddr[0] = func;
1449 entry->vaddr[1] = instruction_pointer(regs);
1450 data = DATAOF_TRACE_ENTRY(entry, true);
1451 } else {
1452 entry->vaddr[0] = instruction_pointer(regs);
1453 data = DATAOF_TRACE_ENTRY(entry, false);
1454 }
1455
1456 memcpy(to: data, from: ucb->buf, len: ucb->dsize);
1457
1458 if (size - esize > ucb->dsize)
1459 memset(s: data + ucb->dsize, c: 0, n: size - esize - ucb->dsize);
1460
1461 perf_trace_buf_submit(raw_data: entry, size, rctx, type: call->event.type, count: 1, regs,
1462 head, NULL);
1463 out:
1464 preempt_enable();
1465}
1466
1467/* uprobe profile handler */
1468static int uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs,
1469 struct uprobe_cpu_buffer **ucbp)
1470{
1471 if (!uprobe_perf_filter(uc: &tu->consumer, current->mm))
1472 return UPROBE_HANDLER_REMOVE;
1473
1474 if (!is_ret_probe(tu))
1475 __uprobe_perf_func(tu, func: 0, regs, ucbp);
1476 return 0;
1477}
1478
1479static void uretprobe_perf_func(struct trace_uprobe *tu, unsigned long func,
1480 struct pt_regs *regs,
1481 struct uprobe_cpu_buffer **ucbp)
1482{
1483 __uprobe_perf_func(tu, func, regs, ucbp);
1484}
1485
1486int bpf_get_uprobe_info(const struct perf_event *event, u32 *fd_type,
1487 const char **filename, u64 *probe_offset,
1488 u64 *probe_addr, bool perf_type_tracepoint)
1489{
1490 const char *pevent = trace_event_name(call: event->tp_event);
1491 const char *group = event->tp_event->class->system;
1492 struct trace_uprobe *tu;
1493
1494 if (perf_type_tracepoint)
1495 tu = find_probe_event(event: pevent, group);
1496 else
1497 tu = trace_uprobe_primary_from_call(call: event->tp_event);
1498 if (!tu)
1499 return -EINVAL;
1500
1501 *fd_type = is_ret_probe(tu) ? BPF_FD_TYPE_URETPROBE
1502 : BPF_FD_TYPE_UPROBE;
1503 *filename = tu->filename;
1504 *probe_offset = tu->offset;
1505 *probe_addr = tu->ref_ctr_offset;
1506 return 0;
1507}
1508#endif /* CONFIG_PERF_EVENTS */
1509
1510static int
1511trace_uprobe_register(struct trace_event_call *event, enum trace_reg type,
1512 void *data)
1513{
1514 struct trace_event_file *file = data;
1515
1516 switch (type) {
1517 case TRACE_REG_REGISTER:
1518 return probe_event_enable(call: event, file, NULL);
1519
1520 case TRACE_REG_UNREGISTER:
1521 probe_event_disable(call: event, file);
1522 return 0;
1523
1524#ifdef CONFIG_PERF_EVENTS
1525 case TRACE_REG_PERF_REGISTER:
1526 return probe_event_enable(call: event, NULL, filter: uprobe_perf_filter);
1527
1528 case TRACE_REG_PERF_UNREGISTER:
1529 probe_event_disable(call: event, NULL);
1530 return 0;
1531
1532 case TRACE_REG_PERF_OPEN:
1533 return uprobe_perf_open(call: event, event: data);
1534
1535 case TRACE_REG_PERF_CLOSE:
1536 return uprobe_perf_close(call: event, event: data);
1537
1538#endif
1539 default:
1540 return 0;
1541 }
1542}
1543
1544static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs,
1545 __u64 *data)
1546{
1547 struct trace_uprobe *tu;
1548 struct uprobe_dispatch_data udd;
1549 struct uprobe_cpu_buffer *ucb = NULL;
1550 unsigned int flags;
1551 int ret = 0;
1552
1553 tu = container_of(con, struct trace_uprobe, consumer);
1554
1555 this_cpu_inc(*tu->nhits);
1556
1557 udd.tu = tu;
1558 udd.bp_addr = instruction_pointer(regs);
1559
1560 current->utask->vaddr = (unsigned long) &udd;
1561
1562 if (WARN_ON_ONCE(!uprobe_cpu_buffer))
1563 return 0;
1564
1565 flags = trace_probe_load_flag(tp: &tu->tp);
1566 if (flags & TP_FLAG_TRACE)
1567 ret |= uprobe_trace_func(tu, regs, ucbp: &ucb);
1568
1569#ifdef CONFIG_PERF_EVENTS
1570 if (flags & TP_FLAG_PROFILE)
1571 ret |= uprobe_perf_func(tu, regs, ucbp: &ucb);
1572#endif
1573 uprobe_buffer_put(ucb);
1574 return ret;
1575}
1576
1577static int uretprobe_dispatcher(struct uprobe_consumer *con,
1578 unsigned long func, struct pt_regs *regs,
1579 __u64 *data)
1580{
1581 struct trace_uprobe *tu;
1582 struct uprobe_dispatch_data udd;
1583 struct uprobe_cpu_buffer *ucb = NULL;
1584 unsigned int flags;
1585
1586 tu = container_of(con, struct trace_uprobe, consumer);
1587
1588 udd.tu = tu;
1589 udd.bp_addr = func;
1590
1591 current->utask->vaddr = (unsigned long) &udd;
1592
1593 if (WARN_ON_ONCE(!uprobe_cpu_buffer))
1594 return 0;
1595
1596 flags = trace_probe_load_flag(tp: &tu->tp);
1597 if (flags & TP_FLAG_TRACE)
1598 uretprobe_trace_func(tu, func, regs, ucbp: &ucb);
1599
1600#ifdef CONFIG_PERF_EVENTS
1601 if (flags & TP_FLAG_PROFILE)
1602 uretprobe_perf_func(tu, func, regs, ucbp: &ucb);
1603#endif
1604 uprobe_buffer_put(ucb);
1605 return 0;
1606}
1607
1608static struct trace_event_functions uprobe_funcs = {
1609 .trace = print_uprobe_event
1610};
1611
1612static struct trace_event_fields uprobe_fields_array[] = {
1613 { .type = TRACE_FUNCTION_TYPE,
1614 .define_fields = uprobe_event_define_fields },
1615 {}
1616};
1617
1618static inline void init_trace_event_call(struct trace_uprobe *tu)
1619{
1620 struct trace_event_call *call = trace_probe_event_call(tp: &tu->tp);
1621 call->event.funcs = &uprobe_funcs;
1622 call->class->fields_array = uprobe_fields_array;
1623
1624 call->flags = TRACE_EVENT_FL_UPROBE | TRACE_EVENT_FL_CAP_ANY;
1625 call->class->reg = trace_uprobe_register;
1626}
1627
1628static int register_uprobe_event(struct trace_uprobe *tu)
1629{
1630 init_trace_event_call(tu);
1631
1632 return trace_probe_register_event_call(tp: &tu->tp);
1633}
1634
1635static int unregister_uprobe_event(struct trace_uprobe *tu)
1636{
1637 return trace_probe_unregister_event_call(tp: &tu->tp);
1638}
1639
1640#ifdef CONFIG_PERF_EVENTS
1641struct trace_event_call *
1642create_local_trace_uprobe(char *name, unsigned long offs,
1643 unsigned long ref_ctr_offset, bool is_return)
1644{
1645 enum probe_print_type ptype;
1646 struct trace_uprobe *tu;
1647 struct path path;
1648 int ret;
1649
1650 ret = kern_path(name, LOOKUP_FOLLOW, &path);
1651 if (ret)
1652 return ERR_PTR(error: ret);
1653
1654 if (!d_is_reg(dentry: path.dentry)) {
1655 path_put(&path);
1656 return ERR_PTR(error: -EINVAL);
1657 }
1658
1659 /*
1660 * local trace_kprobes are not added to dyn_event, so they are never
1661 * searched in find_trace_kprobe(). Therefore, there is no concern of
1662 * duplicated name "DUMMY_EVENT" here.
1663 */
1664 tu = alloc_trace_uprobe(UPROBE_EVENT_SYSTEM, event: "DUMMY_EVENT", nargs: 0,
1665 is_ret: is_return);
1666
1667 if (IS_ERR(ptr: tu)) {
1668 pr_info("Failed to allocate trace_uprobe.(%d)\n",
1669 (int)PTR_ERR(tu));
1670 path_put(&path);
1671 return ERR_CAST(ptr: tu);
1672 }
1673
1674 tu->offset = offs;
1675 tu->path = path;
1676 tu->ref_ctr_offset = ref_ctr_offset;
1677 tu->filename = kstrdup(s: name, GFP_KERNEL);
1678 if (!tu->filename) {
1679 ret = -ENOMEM;
1680 goto error;
1681 }
1682
1683 init_trace_event_call(tu);
1684
1685 ptype = is_ret_probe(tu) ? PROBE_PRINT_RETURN : PROBE_PRINT_NORMAL;
1686 if (traceprobe_set_print_fmt(tp: &tu->tp, ptype) < 0) {
1687 ret = -ENOMEM;
1688 goto error;
1689 }
1690
1691 return trace_probe_event_call(tp: &tu->tp);
1692error:
1693 free_trace_uprobe(tu);
1694 return ERR_PTR(error: ret);
1695}
1696
1697void destroy_local_trace_uprobe(struct trace_event_call *event_call)
1698{
1699 struct trace_uprobe *tu;
1700
1701 tu = trace_uprobe_primary_from_call(call: event_call);
1702
1703 free_trace_uprobe(tu);
1704}
1705#endif /* CONFIG_PERF_EVENTS */
1706
1707/* Make a trace interface for controlling probe points */
1708static __init int init_uprobe_trace(void)
1709{
1710 int ret;
1711
1712 ret = dyn_event_register(ops: &trace_uprobe_ops);
1713 if (ret)
1714 return ret;
1715
1716 ret = tracing_init_dentry();
1717 if (ret)
1718 return 0;
1719
1720 trace_create_file(name: "uprobe_events", TRACE_MODE_WRITE, NULL,
1721 NULL, fops: &uprobe_events_ops);
1722 /* Profile interface */
1723 trace_create_file(name: "uprobe_profile", TRACE_MODE_READ, NULL,
1724 NULL, fops: &uprobe_profile_ops);
1725 return 0;
1726}
1727
1728fs_initcall(init_uprobe_trace);
1729