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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
53
54struct trace_uprobe {
55 struct list_head list;
56 struct trace_uprobe_filter filter;
57 struct uprobe_consumer consumer;
58 struct inode *inode;
59 char *filename;
60 unsigned long offset;
61 unsigned long nhit;
62 struct trace_probe tp;
63};
64
65#define SIZEOF_TRACE_UPROBE(n) \
66 (offsetof(struct trace_uprobe, tp.args) + \
67 (sizeof(struct probe_arg) * (n)))
68
69static int register_uprobe_event(struct trace_uprobe *tu);
70static int unregister_uprobe_event(struct trace_uprobe *tu);
71
72static DEFINE_MUTEX(uprobe_lock);
73static LIST_HEAD(uprobe_list);
74
75struct uprobe_dispatch_data {
76 struct trace_uprobe *tu;
77 unsigned long bp_addr;
78};
79
80static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs);
81static int uretprobe_dispatcher(struct uprobe_consumer *con,
82 unsigned long func, struct pt_regs *regs);
83
84#ifdef CONFIG_STACK_GROWSUP
85static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n)
86{
87 return addr - (n * sizeof(long));
88}
89#else
90static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n)
91{
92 return addr + (n * sizeof(long));
93}
94#endif
95
96static unsigned long get_user_stack_nth(struct pt_regs *regs, unsigned int n)
97{
98 unsigned long ret;
99 unsigned long addr = user_stack_pointer(regs);
100
101 addr = adjust_stack_addr(addr, n);
102
103 if (copy_from_user(&ret, (void __force __user *) addr, sizeof(ret)))
104 return 0;
105
106 return ret;
107}
108
109
110
111
112#define DEFINE_FETCH_stack(type) \
113static void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs, \
114 void *offset, void *dest) \
115{ \
116 *(type *)dest = (type)get_user_stack_nth(regs, \
117 ((unsigned long)offset)); \
118}
119DEFINE_BASIC_FETCH_FUNCS(stack)
120
121#define fetch_stack_string NULL
122#define fetch_stack_string_size NULL
123
124#define DEFINE_FETCH_memory(type) \
125static void FETCH_FUNC_NAME(memory, type)(struct pt_regs *regs, \
126 void *addr, void *dest) \
127{ \
128 type retval; \
129 void __user *vaddr = (void __force __user *) addr; \
130 \
131 if (copy_from_user(&retval, vaddr, sizeof(type))) \
132 *(type *)dest = 0; \
133 else \
134 *(type *) dest = retval; \
135}
136DEFINE_BASIC_FETCH_FUNCS(memory)
137
138
139
140
141static void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs,
142 void *addr, void *dest)
143{
144 long ret;
145 u32 rloc = *(u32 *)dest;
146 int maxlen = get_rloc_len(rloc);
147 u8 *dst = get_rloc_data(dest);
148 void __user *src = (void __force __user *) addr;
149
150 if (!maxlen)
151 return;
152
153 ret = strncpy_from_user(dst, src, maxlen);
154
155 if (ret < 0) {
156 ((u8 *)get_rloc_data(dest))[0] = '\0';
157 *(u32 *)dest = make_data_rloc(0, get_rloc_offs(rloc));
158 } else {
159 *(u32 *)dest = make_data_rloc(ret, get_rloc_offs(rloc));
160 }
161}
162
163static void FETCH_FUNC_NAME(memory, string_size)(struct pt_regs *regs,
164 void *addr, void *dest)
165{
166 int len;
167 void __user *vaddr = (void __force __user *) addr;
168
169 len = strnlen_user(vaddr, MAX_STRING_SIZE);
170
171 if (len == 0 || len > MAX_STRING_SIZE)
172 *(u32 *)dest = 0;
173 else
174 *(u32 *)dest = len;
175}
176
177static unsigned long translate_user_vaddr(void *file_offset)
178{
179 unsigned long base_addr;
180 struct uprobe_dispatch_data *udd;
181
182 udd = (void *) current->utask->vaddr;
183
184 base_addr = udd->bp_addr - udd->tu->offset;
185 return base_addr + (unsigned long)file_offset;
186}
187
188#define DEFINE_FETCH_file_offset(type) \
189static void FETCH_FUNC_NAME(file_offset, type)(struct pt_regs *regs, \
190 void *offset, void *dest)\
191{ \
192 void *vaddr = (void *)translate_user_vaddr(offset); \
193 \
194 FETCH_FUNC_NAME(memory, type)(regs, vaddr, dest); \
195}
196DEFINE_BASIC_FETCH_FUNCS(file_offset)
197DEFINE_FETCH_file_offset(string)
198DEFINE_FETCH_file_offset(string_size)
199
200
201static const struct fetch_type uprobes_fetch_type_table[] = {
202
203 [FETCH_TYPE_STRING] = __ASSIGN_FETCH_TYPE("string", string, string,
204 sizeof(u32), 1, "__data_loc char[]"),
205 [FETCH_TYPE_STRSIZE] = __ASSIGN_FETCH_TYPE("string_size", u32,
206 string_size, sizeof(u32), 0, "u32"),
207
208 ASSIGN_FETCH_TYPE(u8, u8, 0),
209 ASSIGN_FETCH_TYPE(u16, u16, 0),
210 ASSIGN_FETCH_TYPE(u32, u32, 0),
211 ASSIGN_FETCH_TYPE(u64, u64, 0),
212 ASSIGN_FETCH_TYPE(s8, u8, 1),
213 ASSIGN_FETCH_TYPE(s16, u16, 1),
214 ASSIGN_FETCH_TYPE(s32, u32, 1),
215 ASSIGN_FETCH_TYPE(s64, u64, 1),
216 ASSIGN_FETCH_TYPE_ALIAS(x8, u8, u8, 0),
217 ASSIGN_FETCH_TYPE_ALIAS(x16, u16, u16, 0),
218 ASSIGN_FETCH_TYPE_ALIAS(x32, u32, u32, 0),
219 ASSIGN_FETCH_TYPE_ALIAS(x64, u64, u64, 0),
220
221 ASSIGN_FETCH_TYPE_END
222};
223
224static inline void init_trace_uprobe_filter(struct trace_uprobe_filter *filter)
225{
226 rwlock_init(&filter->rwlock);
227 filter->nr_systemwide = 0;
228 INIT_LIST_HEAD(&filter->perf_events);
229}
230
231static inline bool uprobe_filter_is_empty(struct trace_uprobe_filter *filter)
232{
233 return !filter->nr_systemwide && list_empty(&filter->perf_events);
234}
235
236static inline bool is_ret_probe(struct trace_uprobe *tu)
237{
238 return tu->consumer.ret_handler != NULL;
239}
240
241
242
243
244static struct trace_uprobe *
245alloc_trace_uprobe(const char *group, const char *event, int nargs, bool is_ret)
246{
247 struct trace_uprobe *tu;
248
249 if (!event || !is_good_name(event))
250 return ERR_PTR(-EINVAL);
251
252 if (!group || !is_good_name(group))
253 return ERR_PTR(-EINVAL);
254
255 tu = kzalloc(SIZEOF_TRACE_UPROBE(nargs), GFP_KERNEL);
256 if (!tu)
257 return ERR_PTR(-ENOMEM);
258
259 tu->tp.call.class = &tu->tp.class;
260 tu->tp.call.name = kstrdup(event, GFP_KERNEL);
261 if (!tu->tp.call.name)
262 goto error;
263
264 tu->tp.class.system = kstrdup(group, GFP_KERNEL);
265 if (!tu->tp.class.system)
266 goto error;
267
268 INIT_LIST_HEAD(&tu->list);
269 INIT_LIST_HEAD(&tu->tp.files);
270 tu->consumer.handler = uprobe_dispatcher;
271 if (is_ret)
272 tu->consumer.ret_handler = uretprobe_dispatcher;
273 init_trace_uprobe_filter(&tu->filter);
274 return tu;
275
276error:
277 kfree(tu->tp.call.name);
278 kfree(tu);
279
280 return ERR_PTR(-ENOMEM);
281}
282
283static void free_trace_uprobe(struct trace_uprobe *tu)
284{
285 int i;
286
287 for (i = 0; i < tu->tp.nr_args; i++)
288 traceprobe_free_probe_arg(&tu->tp.args[i]);
289
290 iput(tu->inode);
291 kfree(tu->tp.call.class->system);
292 kfree(tu->tp.call.name);
293 kfree(tu->filename);
294 kfree(tu);
295}
296
297static struct trace_uprobe *find_probe_event(const char *event, const char *group)
298{
299 struct trace_uprobe *tu;
300
301 list_for_each_entry(tu, &uprobe_list, list)
302 if (strcmp(trace_event_name(&tu->tp.call), event) == 0 &&
303 strcmp(tu->tp.call.class->system, group) == 0)
304 return tu;
305
306 return NULL;
307}
308
309
310static int unregister_trace_uprobe(struct trace_uprobe *tu)
311{
312 int ret;
313
314 ret = unregister_uprobe_event(tu);
315 if (ret)
316 return ret;
317
318 list_del(&tu->list);
319 free_trace_uprobe(tu);
320 return 0;
321}
322
323
324static int register_trace_uprobe(struct trace_uprobe *tu)
325{
326 struct trace_uprobe *old_tu;
327 int ret;
328
329 mutex_lock(&uprobe_lock);
330
331
332 old_tu = find_probe_event(trace_event_name(&tu->tp.call),
333 tu->tp.call.class->system);
334 if (old_tu) {
335
336 ret = unregister_trace_uprobe(old_tu);
337 if (ret)
338 goto end;
339 }
340
341 ret = register_uprobe_event(tu);
342 if (ret) {
343 pr_warn("Failed to register probe event(%d)\n", ret);
344 goto end;
345 }
346
347 list_add_tail(&tu->list, &uprobe_list);
348
349end:
350 mutex_unlock(&uprobe_lock);
351
352 return ret;
353}
354
355
356
357
358
359
360
361static int create_trace_uprobe(int argc, char **argv)
362{
363 struct trace_uprobe *tu;
364 struct inode *inode;
365 char *arg, *event, *group, *filename;
366 char buf[MAX_EVENT_NAME_LEN];
367 struct path path;
368 unsigned long offset;
369 bool is_delete, is_return;
370 int i, ret;
371
372 inode = NULL;
373 ret = 0;
374 is_delete = false;
375 is_return = false;
376 event = NULL;
377 group = NULL;
378
379
380 if (argv[0][0] == '-')
381 is_delete = true;
382 else if (argv[0][0] == 'r')
383 is_return = true;
384 else if (argv[0][0] != 'p') {
385 pr_info("Probe definition must be started with 'p', 'r' or '-'.\n");
386 return -EINVAL;
387 }
388
389 if (argv[0][1] == ':') {
390 event = &argv[0][2];
391 arg = strchr(event, '/');
392
393 if (arg) {
394 group = event;
395 event = arg + 1;
396 event[-1] = '\0';
397
398 if (strlen(group) == 0) {
399 pr_info("Group name is not specified\n");
400 return -EINVAL;
401 }
402 }
403 if (strlen(event) == 0) {
404 pr_info("Event name is not specified\n");
405 return -EINVAL;
406 }
407 }
408 if (!group)
409 group = UPROBE_EVENT_SYSTEM;
410
411 if (is_delete) {
412 int ret;
413
414 if (!event) {
415 pr_info("Delete command needs an event name.\n");
416 return -EINVAL;
417 }
418 mutex_lock(&uprobe_lock);
419 tu = find_probe_event(event, group);
420
421 if (!tu) {
422 mutex_unlock(&uprobe_lock);
423 pr_info("Event %s/%s doesn't exist.\n", group, event);
424 return -ENOENT;
425 }
426
427 ret = unregister_trace_uprobe(tu);
428 mutex_unlock(&uprobe_lock);
429 return ret;
430 }
431
432 if (argc < 2) {
433 pr_info("Probe point is not specified.\n");
434 return -EINVAL;
435 }
436
437 arg = strrchr(argv[1], ':');
438 if (!arg) {
439 ret = -EINVAL;
440 goto fail_address_parse;
441 }
442
443 *arg++ = '\0';
444 filename = argv[1];
445 ret = kern_path(filename, LOOKUP_FOLLOW, &path);
446 if (ret)
447 goto fail_address_parse;
448
449 inode = igrab(d_inode(path.dentry));
450 path_put(&path);
451
452 if (!inode || !S_ISREG(inode->i_mode)) {
453 ret = -EINVAL;
454 goto fail_address_parse;
455 }
456
457 ret = kstrtoul(arg, 0, &offset);
458 if (ret)
459 goto fail_address_parse;
460
461 argc -= 2;
462 argv += 2;
463
464
465 if (!event) {
466 char *tail;
467 char *ptr;
468
469 tail = kstrdup(kbasename(filename), GFP_KERNEL);
470 if (!tail) {
471 ret = -ENOMEM;
472 goto fail_address_parse;
473 }
474
475 ptr = strpbrk(tail, ".-_");
476 if (ptr)
477 *ptr = '\0';
478
479 snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_0x%lx", 'p', tail, offset);
480 event = buf;
481 kfree(tail);
482 }
483
484 tu = alloc_trace_uprobe(group, event, argc, is_return);
485 if (IS_ERR(tu)) {
486 pr_info("Failed to allocate trace_uprobe.(%d)\n", (int)PTR_ERR(tu));
487 ret = PTR_ERR(tu);
488 goto fail_address_parse;
489 }
490 tu->offset = offset;
491 tu->inode = inode;
492 tu->filename = kstrdup(filename, GFP_KERNEL);
493
494 if (!tu->filename) {
495 pr_info("Failed to allocate filename.\n");
496 ret = -ENOMEM;
497 goto error;
498 }
499
500
501 ret = 0;
502 for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) {
503 struct probe_arg *parg = &tu->tp.args[i];
504
505
506 tu->tp.nr_args++;
507
508
509 arg = strchr(argv[i], '=');
510 if (arg) {
511 *arg++ = '\0';
512 parg->name = kstrdup(argv[i], GFP_KERNEL);
513 } else {
514 arg = argv[i];
515
516 snprintf(buf, MAX_EVENT_NAME_LEN, "arg%d", i + 1);
517 parg->name = kstrdup(buf, GFP_KERNEL);
518 }
519
520 if (!parg->name) {
521 pr_info("Failed to allocate argument[%d] name.\n", i);
522 ret = -ENOMEM;
523 goto error;
524 }
525
526 if (!is_good_name(parg->name)) {
527 pr_info("Invalid argument[%d] name: %s\n", i, parg->name);
528 ret = -EINVAL;
529 goto error;
530 }
531
532 if (traceprobe_conflict_field_name(parg->name, tu->tp.args, i)) {
533 pr_info("Argument[%d] name '%s' conflicts with "
534 "another field.\n", i, argv[i]);
535 ret = -EINVAL;
536 goto error;
537 }
538
539
540 ret = traceprobe_parse_probe_arg(arg, &tu->tp.size, parg,
541 is_return, false,
542 uprobes_fetch_type_table);
543 if (ret) {
544 pr_info("Parse error at argument[%d]. (%d)\n", i, ret);
545 goto error;
546 }
547 }
548
549 ret = register_trace_uprobe(tu);
550 if (ret)
551 goto error;
552 return 0;
553
554error:
555 free_trace_uprobe(tu);
556 return ret;
557
558fail_address_parse:
559 iput(inode);
560
561 pr_info("Failed to parse address or file.\n");
562
563 return ret;
564}
565
566static int cleanup_all_probes(void)
567{
568 struct trace_uprobe *tu;
569 int ret = 0;
570
571 mutex_lock(&uprobe_lock);
572 while (!list_empty(&uprobe_list)) {
573 tu = list_entry(uprobe_list.next, struct trace_uprobe, list);
574 ret = unregister_trace_uprobe(tu);
575 if (ret)
576 break;
577 }
578 mutex_unlock(&uprobe_lock);
579 return ret;
580}
581
582
583static void *probes_seq_start(struct seq_file *m, loff_t *pos)
584{
585 mutex_lock(&uprobe_lock);
586 return seq_list_start(&uprobe_list, *pos);
587}
588
589static void *probes_seq_next(struct seq_file *m, void *v, loff_t *pos)
590{
591 return seq_list_next(v, &uprobe_list, pos);
592}
593
594static void probes_seq_stop(struct seq_file *m, void *v)
595{
596 mutex_unlock(&uprobe_lock);
597}
598
599static int probes_seq_show(struct seq_file *m, void *v)
600{
601 struct trace_uprobe *tu = v;
602 char c = is_ret_probe(tu) ? 'r' : 'p';
603 int i;
604
605 seq_printf(m, "%c:%s/%s", c, tu->tp.call.class->system,
606 trace_event_name(&tu->tp.call));
607 seq_printf(m, " %s:", tu->filename);
608
609
610 if (tu->offset) {
611 seq_printf(m, "0x%p", (void *)tu->offset);
612 } else {
613 switch (sizeof(void *)) {
614 case 4:
615 seq_printf(m, "0x00000000");
616 break;
617 case 8:
618 default:
619 seq_printf(m, "0x0000000000000000");
620 break;
621 }
622 }
623
624 for (i = 0; i < tu->tp.nr_args; i++)
625 seq_printf(m, " %s=%s", tu->tp.args[i].name, tu->tp.args[i].comm);
626
627 seq_putc(m, '\n');
628 return 0;
629}
630
631static const struct seq_operations probes_seq_op = {
632 .start = probes_seq_start,
633 .next = probes_seq_next,
634 .stop = probes_seq_stop,
635 .show = probes_seq_show
636};
637
638static int probes_open(struct inode *inode, struct file *file)
639{
640 int ret;
641
642 if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
643 ret = cleanup_all_probes();
644 if (ret)
645 return ret;
646 }
647
648 return seq_open(file, &probes_seq_op);
649}
650
651static ssize_t probes_write(struct file *file, const char __user *buffer,
652 size_t count, loff_t *ppos)
653{
654 return traceprobe_probes_write(file, buffer, count, ppos, create_trace_uprobe);
655}
656
657static const struct file_operations uprobe_events_ops = {
658 .owner = THIS_MODULE,
659 .open = probes_open,
660 .read = seq_read,
661 .llseek = seq_lseek,
662 .release = seq_release,
663 .write = probes_write,
664};
665
666
667static int probes_profile_seq_show(struct seq_file *m, void *v)
668{
669 struct trace_uprobe *tu = v;
670
671 seq_printf(m, " %s %-44s %15lu\n", tu->filename,
672 trace_event_name(&tu->tp.call), tu->nhit);
673 return 0;
674}
675
676static const struct seq_operations profile_seq_op = {
677 .start = probes_seq_start,
678 .next = probes_seq_next,
679 .stop = probes_seq_stop,
680 .show = probes_profile_seq_show
681};
682
683static int profile_open(struct inode *inode, struct file *file)
684{
685 return seq_open(file, &profile_seq_op);
686}
687
688static const struct file_operations uprobe_profile_ops = {
689 .owner = THIS_MODULE,
690 .open = profile_open,
691 .read = seq_read,
692 .llseek = seq_lseek,
693 .release = seq_release,
694};
695
696struct uprobe_cpu_buffer {
697 struct mutex mutex;
698 void *buf;
699};
700static struct uprobe_cpu_buffer __percpu *uprobe_cpu_buffer;
701static int uprobe_buffer_refcnt;
702
703static int uprobe_buffer_init(void)
704{
705 int cpu, err_cpu;
706
707 uprobe_cpu_buffer = alloc_percpu(struct uprobe_cpu_buffer);
708 if (uprobe_cpu_buffer == NULL)
709 return -ENOMEM;
710
711 for_each_possible_cpu(cpu) {
712 struct page *p = alloc_pages_node(cpu_to_node(cpu),
713 GFP_KERNEL, 0);
714 if (p == NULL) {
715 err_cpu = cpu;
716 goto err;
717 }
718 per_cpu_ptr(uprobe_cpu_buffer, cpu)->buf = page_address(p);
719 mutex_init(&per_cpu_ptr(uprobe_cpu_buffer, cpu)->mutex);
720 }
721
722 return 0;
723
724err:
725 for_each_possible_cpu(cpu) {
726 if (cpu == err_cpu)
727 break;
728 free_page((unsigned long)per_cpu_ptr(uprobe_cpu_buffer, cpu)->buf);
729 }
730
731 free_percpu(uprobe_cpu_buffer);
732 return -ENOMEM;
733}
734
735static int uprobe_buffer_enable(void)
736{
737 int ret = 0;
738
739 BUG_ON(!mutex_is_locked(&event_mutex));
740
741 if (uprobe_buffer_refcnt++ == 0) {
742 ret = uprobe_buffer_init();
743 if (ret < 0)
744 uprobe_buffer_refcnt--;
745 }
746
747 return ret;
748}
749
750static void uprobe_buffer_disable(void)
751{
752 int cpu;
753
754 BUG_ON(!mutex_is_locked(&event_mutex));
755
756 if (--uprobe_buffer_refcnt == 0) {
757 for_each_possible_cpu(cpu)
758 free_page((unsigned long)per_cpu_ptr(uprobe_cpu_buffer,
759 cpu)->buf);
760
761 free_percpu(uprobe_cpu_buffer);
762 uprobe_cpu_buffer = NULL;
763 }
764}
765
766static struct uprobe_cpu_buffer *uprobe_buffer_get(void)
767{
768 struct uprobe_cpu_buffer *ucb;
769 int cpu;
770
771 cpu = raw_smp_processor_id();
772 ucb = per_cpu_ptr(uprobe_cpu_buffer, cpu);
773
774
775
776
777
778 mutex_lock(&ucb->mutex);
779
780 return ucb;
781}
782
783static void uprobe_buffer_put(struct uprobe_cpu_buffer *ucb)
784{
785 mutex_unlock(&ucb->mutex);
786}
787
788static void __uprobe_trace_func(struct trace_uprobe *tu,
789 unsigned long func, struct pt_regs *regs,
790 struct uprobe_cpu_buffer *ucb, int dsize,
791 struct trace_event_file *trace_file)
792{
793 struct uprobe_trace_entry_head *entry;
794 struct ring_buffer_event *event;
795 struct ring_buffer *buffer;
796 void *data;
797 int size, esize;
798 struct trace_event_call *call = &tu->tp.call;
799
800 WARN_ON(call != trace_file->event_call);
801
802 if (WARN_ON_ONCE(tu->tp.size + dsize > PAGE_SIZE))
803 return;
804
805 if (trace_trigger_soft_disabled(trace_file))
806 return;
807
808 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
809 size = esize + tu->tp.size + dsize;
810 event = trace_event_buffer_lock_reserve(&buffer, trace_file,
811 call->event.type, size, 0, 0);
812 if (!event)
813 return;
814
815 entry = ring_buffer_event_data(event);
816 if (is_ret_probe(tu)) {
817 entry->vaddr[0] = func;
818 entry->vaddr[1] = instruction_pointer(regs);
819 data = DATAOF_TRACE_ENTRY(entry, true);
820 } else {
821 entry->vaddr[0] = instruction_pointer(regs);
822 data = DATAOF_TRACE_ENTRY(entry, false);
823 }
824
825 memcpy(data, ucb->buf, tu->tp.size + dsize);
826
827 event_trigger_unlock_commit(trace_file, buffer, event, entry, 0, 0);
828}
829
830
831static int uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs,
832 struct uprobe_cpu_buffer *ucb, int dsize)
833{
834 struct event_file_link *link;
835
836 if (is_ret_probe(tu))
837 return 0;
838
839 rcu_read_lock();
840 list_for_each_entry_rcu(link, &tu->tp.files, list)
841 __uprobe_trace_func(tu, 0, regs, ucb, dsize, link->file);
842 rcu_read_unlock();
843
844 return 0;
845}
846
847static void uretprobe_trace_func(struct trace_uprobe *tu, unsigned long func,
848 struct pt_regs *regs,
849 struct uprobe_cpu_buffer *ucb, int dsize)
850{
851 struct event_file_link *link;
852
853 rcu_read_lock();
854 list_for_each_entry_rcu(link, &tu->tp.files, list)
855 __uprobe_trace_func(tu, func, regs, ucb, dsize, link->file);
856 rcu_read_unlock();
857}
858
859
860static enum print_line_t
861print_uprobe_event(struct trace_iterator *iter, int flags, struct trace_event *event)
862{
863 struct uprobe_trace_entry_head *entry;
864 struct trace_seq *s = &iter->seq;
865 struct trace_uprobe *tu;
866 u8 *data;
867 int i;
868
869 entry = (struct uprobe_trace_entry_head *)iter->ent;
870 tu = container_of(event, struct trace_uprobe, tp.call.event);
871
872 if (is_ret_probe(tu)) {
873 trace_seq_printf(s, "%s: (0x%lx <- 0x%lx)",
874 trace_event_name(&tu->tp.call),
875 entry->vaddr[1], entry->vaddr[0]);
876 data = DATAOF_TRACE_ENTRY(entry, true);
877 } else {
878 trace_seq_printf(s, "%s: (0x%lx)",
879 trace_event_name(&tu->tp.call),
880 entry->vaddr[0]);
881 data = DATAOF_TRACE_ENTRY(entry, false);
882 }
883
884 for (i = 0; i < tu->tp.nr_args; i++) {
885 struct probe_arg *parg = &tu->tp.args[i];
886
887 if (!parg->type->print(s, parg->name, data + parg->offset, entry))
888 goto out;
889 }
890
891 trace_seq_putc(s, '\n');
892
893 out:
894 return trace_handle_return(s);
895}
896
897typedef bool (*filter_func_t)(struct uprobe_consumer *self,
898 enum uprobe_filter_ctx ctx,
899 struct mm_struct *mm);
900
901static int
902probe_event_enable(struct trace_uprobe *tu, struct trace_event_file *file,
903 filter_func_t filter)
904{
905 bool enabled = trace_probe_is_enabled(&tu->tp);
906 struct event_file_link *link = NULL;
907 int ret;
908
909 if (file) {
910 if (tu->tp.flags & TP_FLAG_PROFILE)
911 return -EINTR;
912
913 link = kmalloc(sizeof(*link), GFP_KERNEL);
914 if (!link)
915 return -ENOMEM;
916
917 link->file = file;
918 list_add_tail_rcu(&link->list, &tu->tp.files);
919
920 tu->tp.flags |= TP_FLAG_TRACE;
921 } else {
922 if (tu->tp.flags & TP_FLAG_TRACE)
923 return -EINTR;
924
925 tu->tp.flags |= TP_FLAG_PROFILE;
926 }
927
928 WARN_ON(!uprobe_filter_is_empty(&tu->filter));
929
930 if (enabled)
931 return 0;
932
933 ret = uprobe_buffer_enable();
934 if (ret)
935 goto err_flags;
936
937 tu->consumer.filter = filter;
938 ret = uprobe_register(tu->inode, tu->offset, &tu->consumer);
939 if (ret)
940 goto err_buffer;
941
942 return 0;
943
944 err_buffer:
945 uprobe_buffer_disable();
946
947 err_flags:
948 if (file) {
949 list_del(&link->list);
950 kfree(link);
951 tu->tp.flags &= ~TP_FLAG_TRACE;
952 } else {
953 tu->tp.flags &= ~TP_FLAG_PROFILE;
954 }
955 return ret;
956}
957
958static void
959probe_event_disable(struct trace_uprobe *tu, struct trace_event_file *file)
960{
961 if (!trace_probe_is_enabled(&tu->tp))
962 return;
963
964 if (file) {
965 struct event_file_link *link;
966
967 link = find_event_file_link(&tu->tp, file);
968 if (!link)
969 return;
970
971 list_del_rcu(&link->list);
972
973 synchronize_sched();
974 kfree(link);
975
976 if (!list_empty(&tu->tp.files))
977 return;
978 }
979
980 WARN_ON(!uprobe_filter_is_empty(&tu->filter));
981
982 uprobe_unregister(tu->inode, tu->offset, &tu->consumer);
983 tu->tp.flags &= file ? ~TP_FLAG_TRACE : ~TP_FLAG_PROFILE;
984
985 uprobe_buffer_disable();
986}
987
988static int uprobe_event_define_fields(struct trace_event_call *event_call)
989{
990 int ret, i, size;
991 struct uprobe_trace_entry_head field;
992 struct trace_uprobe *tu = event_call->data;
993
994 if (is_ret_probe(tu)) {
995 DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_FUNC, 0);
996 DEFINE_FIELD(unsigned long, vaddr[1], FIELD_STRING_RETIP, 0);
997 size = SIZEOF_TRACE_ENTRY(true);
998 } else {
999 DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_IP, 0);
1000 size = SIZEOF_TRACE_ENTRY(false);
1001 }
1002
1003 for (i = 0; i < tu->tp.nr_args; i++) {
1004 struct probe_arg *parg = &tu->tp.args[i];
1005
1006 ret = trace_define_field(event_call, parg->type->fmttype,
1007 parg->name, size + parg->offset,
1008 parg->type->size, parg->type->is_signed,
1009 FILTER_OTHER);
1010
1011 if (ret)
1012 return ret;
1013 }
1014 return 0;
1015}
1016
1017#ifdef CONFIG_PERF_EVENTS
1018static bool
1019__uprobe_perf_filter(struct trace_uprobe_filter *filter, struct mm_struct *mm)
1020{
1021 struct perf_event *event;
1022
1023 if (filter->nr_systemwide)
1024 return true;
1025
1026 list_for_each_entry(event, &filter->perf_events, hw.tp_list) {
1027 if (event->hw.target->mm == mm)
1028 return true;
1029 }
1030
1031 return false;
1032}
1033
1034static inline bool
1035uprobe_filter_event(struct trace_uprobe *tu, struct perf_event *event)
1036{
1037 return __uprobe_perf_filter(&tu->filter, event->hw.target->mm);
1038}
1039
1040static int uprobe_perf_close(struct trace_uprobe *tu, struct perf_event *event)
1041{
1042 bool done;
1043
1044 write_lock(&tu->filter.rwlock);
1045 if (event->hw.target) {
1046 list_del(&event->hw.tp_list);
1047 done = tu->filter.nr_systemwide ||
1048 (event->hw.target->flags & PF_EXITING) ||
1049 uprobe_filter_event(tu, event);
1050 } else {
1051 tu->filter.nr_systemwide--;
1052 done = tu->filter.nr_systemwide;
1053 }
1054 write_unlock(&tu->filter.rwlock);
1055
1056 if (!done)
1057 return uprobe_apply(tu->inode, tu->offset, &tu->consumer, false);
1058
1059 return 0;
1060}
1061
1062static int uprobe_perf_open(struct trace_uprobe *tu, struct perf_event *event)
1063{
1064 bool done;
1065 int err;
1066
1067 write_lock(&tu->filter.rwlock);
1068 if (event->hw.target) {
1069
1070
1071
1072
1073
1074
1075
1076
1077 done = tu->filter.nr_systemwide ||
1078 event->parent || event->attr.enable_on_exec ||
1079 uprobe_filter_event(tu, event);
1080 list_add(&event->hw.tp_list, &tu->filter.perf_events);
1081 } else {
1082 done = tu->filter.nr_systemwide;
1083 tu->filter.nr_systemwide++;
1084 }
1085 write_unlock(&tu->filter.rwlock);
1086
1087 err = 0;
1088 if (!done) {
1089 err = uprobe_apply(tu->inode, tu->offset, &tu->consumer, true);
1090 if (err)
1091 uprobe_perf_close(tu, event);
1092 }
1093 return err;
1094}
1095
1096static bool uprobe_perf_filter(struct uprobe_consumer *uc,
1097 enum uprobe_filter_ctx ctx, struct mm_struct *mm)
1098{
1099 struct trace_uprobe *tu;
1100 int ret;
1101
1102 tu = container_of(uc, struct trace_uprobe, consumer);
1103 read_lock(&tu->filter.rwlock);
1104 ret = __uprobe_perf_filter(&tu->filter, mm);
1105 read_unlock(&tu->filter.rwlock);
1106
1107 return ret;
1108}
1109
1110static void __uprobe_perf_func(struct trace_uprobe *tu,
1111 unsigned long func, struct pt_regs *regs,
1112 struct uprobe_cpu_buffer *ucb, int dsize)
1113{
1114 struct trace_event_call *call = &tu->tp.call;
1115 struct uprobe_trace_entry_head *entry;
1116 struct bpf_prog *prog = call->prog;
1117 struct hlist_head *head;
1118 void *data;
1119 int size, esize;
1120 int rctx;
1121
1122 if (prog && !trace_call_bpf(prog, regs))
1123 return;
1124
1125 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
1126
1127 size = esize + tu->tp.size + dsize;
1128 size = ALIGN(size + sizeof(u32), sizeof(u64)) - sizeof(u32);
1129 if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, "profile buffer not large enough"))
1130 return;
1131
1132 preempt_disable();
1133 head = this_cpu_ptr(call->perf_events);
1134 if (hlist_empty(head))
1135 goto out;
1136
1137 entry = perf_trace_buf_alloc(size, NULL, &rctx);
1138 if (!entry)
1139 goto out;
1140
1141 if (is_ret_probe(tu)) {
1142 entry->vaddr[0] = func;
1143 entry->vaddr[1] = instruction_pointer(regs);
1144 data = DATAOF_TRACE_ENTRY(entry, true);
1145 } else {
1146 entry->vaddr[0] = instruction_pointer(regs);
1147 data = DATAOF_TRACE_ENTRY(entry, false);
1148 }
1149
1150 memcpy(data, ucb->buf, tu->tp.size + dsize);
1151
1152 if (size - esize > tu->tp.size + dsize) {
1153 int len = tu->tp.size + dsize;
1154
1155 memset(data + len, 0, size - esize - len);
1156 }
1157
1158 perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs,
1159 head, NULL, NULL);
1160 out:
1161 preempt_enable();
1162}
1163
1164
1165static int uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs,
1166 struct uprobe_cpu_buffer *ucb, int dsize)
1167{
1168 if (!uprobe_perf_filter(&tu->consumer, 0, current->mm))
1169 return UPROBE_HANDLER_REMOVE;
1170
1171 if (!is_ret_probe(tu))
1172 __uprobe_perf_func(tu, 0, regs, ucb, dsize);
1173 return 0;
1174}
1175
1176static void uretprobe_perf_func(struct trace_uprobe *tu, unsigned long func,
1177 struct pt_regs *regs,
1178 struct uprobe_cpu_buffer *ucb, int dsize)
1179{
1180 __uprobe_perf_func(tu, func, regs, ucb, dsize);
1181}
1182#endif
1183
1184static int
1185trace_uprobe_register(struct trace_event_call *event, enum trace_reg type,
1186 void *data)
1187{
1188 struct trace_uprobe *tu = event->data;
1189 struct trace_event_file *file = data;
1190
1191 switch (type) {
1192 case TRACE_REG_REGISTER:
1193 return probe_event_enable(tu, file, NULL);
1194
1195 case TRACE_REG_UNREGISTER:
1196 probe_event_disable(tu, file);
1197 return 0;
1198
1199#ifdef CONFIG_PERF_EVENTS
1200 case TRACE_REG_PERF_REGISTER:
1201 return probe_event_enable(tu, NULL, uprobe_perf_filter);
1202
1203 case TRACE_REG_PERF_UNREGISTER:
1204 probe_event_disable(tu, NULL);
1205 return 0;
1206
1207 case TRACE_REG_PERF_OPEN:
1208 return uprobe_perf_open(tu, data);
1209
1210 case TRACE_REG_PERF_CLOSE:
1211 return uprobe_perf_close(tu, data);
1212
1213#endif
1214 default:
1215 return 0;
1216 }
1217 return 0;
1218}
1219
1220static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs)
1221{
1222 struct trace_uprobe *tu;
1223 struct uprobe_dispatch_data udd;
1224 struct uprobe_cpu_buffer *ucb;
1225 int dsize, esize;
1226 int ret = 0;
1227
1228
1229 tu = container_of(con, struct trace_uprobe, consumer);
1230 tu->nhit++;
1231
1232 udd.tu = tu;
1233 udd.bp_addr = instruction_pointer(regs);
1234
1235 current->utask->vaddr = (unsigned long) &udd;
1236
1237 if (WARN_ON_ONCE(!uprobe_cpu_buffer))
1238 return 0;
1239
1240 dsize = __get_data_size(&tu->tp, regs);
1241 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
1242
1243 ucb = uprobe_buffer_get();
1244 store_trace_args(esize, &tu->tp, regs, ucb->buf, dsize);
1245
1246 if (tu->tp.flags & TP_FLAG_TRACE)
1247 ret |= uprobe_trace_func(tu, regs, ucb, dsize);
1248
1249#ifdef CONFIG_PERF_EVENTS
1250 if (tu->tp.flags & TP_FLAG_PROFILE)
1251 ret |= uprobe_perf_func(tu, regs, ucb, dsize);
1252#endif
1253 uprobe_buffer_put(ucb);
1254 return ret;
1255}
1256
1257static int uretprobe_dispatcher(struct uprobe_consumer *con,
1258 unsigned long func, struct pt_regs *regs)
1259{
1260 struct trace_uprobe *tu;
1261 struct uprobe_dispatch_data udd;
1262 struct uprobe_cpu_buffer *ucb;
1263 int dsize, esize;
1264
1265 tu = container_of(con, struct trace_uprobe, consumer);
1266
1267 udd.tu = tu;
1268 udd.bp_addr = func;
1269
1270 current->utask->vaddr = (unsigned long) &udd;
1271
1272 if (WARN_ON_ONCE(!uprobe_cpu_buffer))
1273 return 0;
1274
1275 dsize = __get_data_size(&tu->tp, regs);
1276 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
1277
1278 ucb = uprobe_buffer_get();
1279 store_trace_args(esize, &tu->tp, regs, ucb->buf, dsize);
1280
1281 if (tu->tp.flags & TP_FLAG_TRACE)
1282 uretprobe_trace_func(tu, func, regs, ucb, dsize);
1283
1284#ifdef CONFIG_PERF_EVENTS
1285 if (tu->tp.flags & TP_FLAG_PROFILE)
1286 uretprobe_perf_func(tu, func, regs, ucb, dsize);
1287#endif
1288 uprobe_buffer_put(ucb);
1289 return 0;
1290}
1291
1292static struct trace_event_functions uprobe_funcs = {
1293 .trace = print_uprobe_event
1294};
1295
1296static int register_uprobe_event(struct trace_uprobe *tu)
1297{
1298 struct trace_event_call *call = &tu->tp.call;
1299 int ret;
1300
1301
1302 INIT_LIST_HEAD(&call->class->fields);
1303 call->event.funcs = &uprobe_funcs;
1304 call->class->define_fields = uprobe_event_define_fields;
1305
1306 if (set_print_fmt(&tu->tp, is_ret_probe(tu)) < 0)
1307 return -ENOMEM;
1308
1309 ret = register_trace_event(&call->event);
1310 if (!ret) {
1311 kfree(call->print_fmt);
1312 return -ENODEV;
1313 }
1314
1315 call->flags = TRACE_EVENT_FL_UPROBE;
1316 call->class->reg = trace_uprobe_register;
1317 call->data = tu;
1318 ret = trace_add_event_call(call);
1319
1320 if (ret) {
1321 pr_info("Failed to register uprobe event: %s\n",
1322 trace_event_name(call));
1323 kfree(call->print_fmt);
1324 unregister_trace_event(&call->event);
1325 }
1326
1327 return ret;
1328}
1329
1330static int unregister_uprobe_event(struct trace_uprobe *tu)
1331{
1332 int ret;
1333
1334
1335 ret = trace_remove_event_call(&tu->tp.call);
1336 if (ret)
1337 return ret;
1338 kfree(tu->tp.call.print_fmt);
1339 tu->tp.call.print_fmt = NULL;
1340 return 0;
1341}
1342
1343
1344static __init int init_uprobe_trace(void)
1345{
1346 struct dentry *d_tracer;
1347
1348 d_tracer = tracing_init_dentry();
1349 if (IS_ERR(d_tracer))
1350 return 0;
1351
1352 trace_create_file("uprobe_events", 0644, d_tracer,
1353 NULL, &uprobe_events_ops);
1354
1355 trace_create_file("uprobe_profile", 0444, d_tracer,
1356 NULL, &uprobe_profile_ops);
1357 return 0;
1358}
1359
1360fs_initcall(init_uprobe_trace);
1361
