This source file includes following definitions.
- syscall_get_enter_fields
- arch_syscall_match_sym_name
- trace_get_syscall_nr
- trace_get_syscall_nr
- find_syscall_meta
- syscall_nr_to_meta
- get_syscall_name
- print_syscall_enter
- print_syscall_exit
- __set_enter_print_fmt
- set_syscall_print_fmt
- free_syscall_print_fmt
- syscall_enter_define_fields
- syscall_exit_define_fields
- ftrace_syscall_enter
- ftrace_syscall_exit
- reg_event_syscall_enter
- unreg_event_syscall_enter
- reg_event_syscall_exit
- unreg_event_syscall_exit
- init_syscall_trace
- arch_syscall_addr
- init_ftrace_syscalls
- perf_call_bpf_enter
- perf_syscall_enter
- perf_sysenter_enable
- perf_sysenter_disable
- perf_call_bpf_exit
- perf_syscall_exit
- perf_sysexit_enable
- perf_sysexit_disable
- syscall_enter_register
- syscall_exit_register
1
2 #include <trace/syscall.h>
3 #include <trace/events/syscalls.h>
4 #include <linux/syscalls.h>
5 #include <linux/slab.h>
6 #include <linux/kernel.h>
7 #include <linux/module.h>
8 #include <linux/ftrace.h>
9 #include <linux/perf_event.h>
10 #include <asm/syscall.h>
11
12 #include "trace_output.h"
13 #include "trace.h"
14
15 static DEFINE_MUTEX(syscall_trace_lock);
16
17 static int syscall_enter_register(struct trace_event_call *event,
18 enum trace_reg type, void *data);
19 static int syscall_exit_register(struct trace_event_call *event,
20 enum trace_reg type, void *data);
21
22 static struct list_head *
23 syscall_get_enter_fields(struct trace_event_call *call)
24 {
25 struct syscall_metadata *entry = call->data;
26
27 return &entry->enter_fields;
28 }
29
30 extern struct syscall_metadata *__start_syscalls_metadata[];
31 extern struct syscall_metadata *__stop_syscalls_metadata[];
32
33 static struct syscall_metadata **syscalls_metadata;
34
35 #ifndef ARCH_HAS_SYSCALL_MATCH_SYM_NAME
36 static inline bool arch_syscall_match_sym_name(const char *sym, const char *name)
37 {
38
39
40
41
42
43
44 return !strcmp(sym + 3, name + 3);
45 }
46 #endif
47
48 #ifdef ARCH_TRACE_IGNORE_COMPAT_SYSCALLS
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64 static int
65 trace_get_syscall_nr(struct task_struct *task, struct pt_regs *regs)
66 {
67 if (unlikely(arch_trace_is_compat_syscall(regs)))
68 return -1;
69
70 return syscall_get_nr(task, regs);
71 }
72 #else
73 static inline int
74 trace_get_syscall_nr(struct task_struct *task, struct pt_regs *regs)
75 {
76 return syscall_get_nr(task, regs);
77 }
78 #endif
79
80 static __init struct syscall_metadata *
81 find_syscall_meta(unsigned long syscall)
82 {
83 struct syscall_metadata **start;
84 struct syscall_metadata **stop;
85 char str[KSYM_SYMBOL_LEN];
86
87
88 start = __start_syscalls_metadata;
89 stop = __stop_syscalls_metadata;
90 kallsyms_lookup(syscall, NULL, NULL, NULL, str);
91
92 if (arch_syscall_match_sym_name(str, "sys_ni_syscall"))
93 return NULL;
94
95 for ( ; start < stop; start++) {
96 if ((*start)->name && arch_syscall_match_sym_name(str, (*start)->name))
97 return *start;
98 }
99 return NULL;
100 }
101
102 static struct syscall_metadata *syscall_nr_to_meta(int nr)
103 {
104 if (!syscalls_metadata || nr >= NR_syscalls || nr < 0)
105 return NULL;
106
107 return syscalls_metadata[nr];
108 }
109
110 const char *get_syscall_name(int syscall)
111 {
112 struct syscall_metadata *entry;
113
114 entry = syscall_nr_to_meta(syscall);
115 if (!entry)
116 return NULL;
117
118 return entry->name;
119 }
120
121 static enum print_line_t
122 print_syscall_enter(struct trace_iterator *iter, int flags,
123 struct trace_event *event)
124 {
125 struct trace_array *tr = iter->tr;
126 struct trace_seq *s = &iter->seq;
127 struct trace_entry *ent = iter->ent;
128 struct syscall_trace_enter *trace;
129 struct syscall_metadata *entry;
130 int i, syscall;
131
132 trace = (typeof(trace))ent;
133 syscall = trace->nr;
134 entry = syscall_nr_to_meta(syscall);
135
136 if (!entry)
137 goto end;
138
139 if (entry->enter_event->event.type != ent->type) {
140 WARN_ON_ONCE(1);
141 goto end;
142 }
143
144 trace_seq_printf(s, "%s(", entry->name);
145
146 for (i = 0; i < entry->nb_args; i++) {
147
148 if (trace_seq_has_overflowed(s))
149 goto end;
150
151
152 if (tr->trace_flags & TRACE_ITER_VERBOSE)
153 trace_seq_printf(s, "%s ", entry->types[i]);
154
155
156 trace_seq_printf(s, "%s: %lx%s", entry->args[i],
157 trace->args[i],
158 i == entry->nb_args - 1 ? "" : ", ");
159 }
160
161 trace_seq_putc(s, ')');
162 end:
163 trace_seq_putc(s, '\n');
164
165 return trace_handle_return(s);
166 }
167
168 static enum print_line_t
169 print_syscall_exit(struct trace_iterator *iter, int flags,
170 struct trace_event *event)
171 {
172 struct trace_seq *s = &iter->seq;
173 struct trace_entry *ent = iter->ent;
174 struct syscall_trace_exit *trace;
175 int syscall;
176 struct syscall_metadata *entry;
177
178 trace = (typeof(trace))ent;
179 syscall = trace->nr;
180 entry = syscall_nr_to_meta(syscall);
181
182 if (!entry) {
183 trace_seq_putc(s, '\n');
184 goto out;
185 }
186
187 if (entry->exit_event->event.type != ent->type) {
188 WARN_ON_ONCE(1);
189 return TRACE_TYPE_UNHANDLED;
190 }
191
192 trace_seq_printf(s, "%s -> 0x%lx\n", entry->name,
193 trace->ret);
194
195 out:
196 return trace_handle_return(s);
197 }
198
199 extern char *__bad_type_size(void);
200
201 #define SYSCALL_FIELD(type, field, name) \
202 sizeof(type) != sizeof(trace.field) ? \
203 __bad_type_size() : \
204 #type, #name, offsetof(typeof(trace), field), \
205 sizeof(trace.field), is_signed_type(type)
206
207 static int __init
208 __set_enter_print_fmt(struct syscall_metadata *entry, char *buf, int len)
209 {
210 int i;
211 int pos = 0;
212
213
214 #define LEN_OR_ZERO (len ? len - pos : 0)
215
216 pos += snprintf(buf + pos, LEN_OR_ZERO, "\"");
217 for (i = 0; i < entry->nb_args; i++) {
218 pos += snprintf(buf + pos, LEN_OR_ZERO, "%s: 0x%%0%zulx%s",
219 entry->args[i], sizeof(unsigned long),
220 i == entry->nb_args - 1 ? "" : ", ");
221 }
222 pos += snprintf(buf + pos, LEN_OR_ZERO, "\"");
223
224 for (i = 0; i < entry->nb_args; i++) {
225 pos += snprintf(buf + pos, LEN_OR_ZERO,
226 ", ((unsigned long)(REC->%s))", entry->args[i]);
227 }
228
229 #undef LEN_OR_ZERO
230
231
232 return pos;
233 }
234
235 static int __init set_syscall_print_fmt(struct trace_event_call *call)
236 {
237 char *print_fmt;
238 int len;
239 struct syscall_metadata *entry = call->data;
240
241 if (entry->enter_event != call) {
242 call->print_fmt = "\"0x%lx\", REC->ret";
243 return 0;
244 }
245
246
247 len = __set_enter_print_fmt(entry, NULL, 0);
248
249 print_fmt = kmalloc(len + 1, GFP_KERNEL);
250 if (!print_fmt)
251 return -ENOMEM;
252
253
254 __set_enter_print_fmt(entry, print_fmt, len + 1);
255 call->print_fmt = print_fmt;
256
257 return 0;
258 }
259
260 static void __init free_syscall_print_fmt(struct trace_event_call *call)
261 {
262 struct syscall_metadata *entry = call->data;
263
264 if (entry->enter_event == call)
265 kfree(call->print_fmt);
266 }
267
268 static int __init syscall_enter_define_fields(struct trace_event_call *call)
269 {
270 struct syscall_trace_enter trace;
271 struct syscall_metadata *meta = call->data;
272 int ret;
273 int i;
274 int offset = offsetof(typeof(trace), args);
275
276 ret = trace_define_field(call, SYSCALL_FIELD(int, nr, __syscall_nr),
277 FILTER_OTHER);
278 if (ret)
279 return ret;
280
281 for (i = 0; i < meta->nb_args; i++) {
282 ret = trace_define_field(call, meta->types[i],
283 meta->args[i], offset,
284 sizeof(unsigned long), 0,
285 FILTER_OTHER);
286 offset += sizeof(unsigned long);
287 }
288
289 return ret;
290 }
291
292 static int __init syscall_exit_define_fields(struct trace_event_call *call)
293 {
294 struct syscall_trace_exit trace;
295 int ret;
296
297 ret = trace_define_field(call, SYSCALL_FIELD(int, nr, __syscall_nr),
298 FILTER_OTHER);
299 if (ret)
300 return ret;
301
302 ret = trace_define_field(call, SYSCALL_FIELD(long, ret, ret),
303 FILTER_OTHER);
304
305 return ret;
306 }
307
308 static void ftrace_syscall_enter(void *data, struct pt_regs *regs, long id)
309 {
310 struct trace_array *tr = data;
311 struct trace_event_file *trace_file;
312 struct syscall_trace_enter *entry;
313 struct syscall_metadata *sys_data;
314 struct ring_buffer_event *event;
315 struct ring_buffer *buffer;
316 unsigned long irq_flags;
317 unsigned long args[6];
318 int pc;
319 int syscall_nr;
320 int size;
321
322 syscall_nr = trace_get_syscall_nr(current, regs);
323 if (syscall_nr < 0 || syscall_nr >= NR_syscalls)
324 return;
325
326
327 trace_file = rcu_dereference_sched(tr->enter_syscall_files[syscall_nr]);
328 if (!trace_file)
329 return;
330
331 if (trace_trigger_soft_disabled(trace_file))
332 return;
333
334 sys_data = syscall_nr_to_meta(syscall_nr);
335 if (!sys_data)
336 return;
337
338 size = sizeof(*entry) + sizeof(unsigned long) * sys_data->nb_args;
339
340 local_save_flags(irq_flags);
341 pc = preempt_count();
342
343 buffer = tr->trace_buffer.buffer;
344 event = trace_buffer_lock_reserve(buffer,
345 sys_data->enter_event->event.type, size, irq_flags, pc);
346 if (!event)
347 return;
348
349 entry = ring_buffer_event_data(event);
350 entry->nr = syscall_nr;
351 syscall_get_arguments(current, regs, args);
352 memcpy(entry->args, args, sizeof(unsigned long) * sys_data->nb_args);
353
354 event_trigger_unlock_commit(trace_file, buffer, event, entry,
355 irq_flags, pc);
356 }
357
358 static void ftrace_syscall_exit(void *data, struct pt_regs *regs, long ret)
359 {
360 struct trace_array *tr = data;
361 struct trace_event_file *trace_file;
362 struct syscall_trace_exit *entry;
363 struct syscall_metadata *sys_data;
364 struct ring_buffer_event *event;
365 struct ring_buffer *buffer;
366 unsigned long irq_flags;
367 int pc;
368 int syscall_nr;
369
370 syscall_nr = trace_get_syscall_nr(current, regs);
371 if (syscall_nr < 0 || syscall_nr >= NR_syscalls)
372 return;
373
374
375 trace_file = rcu_dereference_sched(tr->exit_syscall_files[syscall_nr]);
376 if (!trace_file)
377 return;
378
379 if (trace_trigger_soft_disabled(trace_file))
380 return;
381
382 sys_data = syscall_nr_to_meta(syscall_nr);
383 if (!sys_data)
384 return;
385
386 local_save_flags(irq_flags);
387 pc = preempt_count();
388
389 buffer = tr->trace_buffer.buffer;
390 event = trace_buffer_lock_reserve(buffer,
391 sys_data->exit_event->event.type, sizeof(*entry),
392 irq_flags, pc);
393 if (!event)
394 return;
395
396 entry = ring_buffer_event_data(event);
397 entry->nr = syscall_nr;
398 entry->ret = syscall_get_return_value(current, regs);
399
400 event_trigger_unlock_commit(trace_file, buffer, event, entry,
401 irq_flags, pc);
402 }
403
404 static int reg_event_syscall_enter(struct trace_event_file *file,
405 struct trace_event_call *call)
406 {
407 struct trace_array *tr = file->tr;
408 int ret = 0;
409 int num;
410
411 num = ((struct syscall_metadata *)call->data)->syscall_nr;
412 if (WARN_ON_ONCE(num < 0 || num >= NR_syscalls))
413 return -ENOSYS;
414 mutex_lock(&syscall_trace_lock);
415 if (!tr->sys_refcount_enter)
416 ret = register_trace_sys_enter(ftrace_syscall_enter, tr);
417 if (!ret) {
418 rcu_assign_pointer(tr->enter_syscall_files[num], file);
419 tr->sys_refcount_enter++;
420 }
421 mutex_unlock(&syscall_trace_lock);
422 return ret;
423 }
424
425 static void unreg_event_syscall_enter(struct trace_event_file *file,
426 struct trace_event_call *call)
427 {
428 struct trace_array *tr = file->tr;
429 int num;
430
431 num = ((struct syscall_metadata *)call->data)->syscall_nr;
432 if (WARN_ON_ONCE(num < 0 || num >= NR_syscalls))
433 return;
434 mutex_lock(&syscall_trace_lock);
435 tr->sys_refcount_enter--;
436 RCU_INIT_POINTER(tr->enter_syscall_files[num], NULL);
437 if (!tr->sys_refcount_enter)
438 unregister_trace_sys_enter(ftrace_syscall_enter, tr);
439 mutex_unlock(&syscall_trace_lock);
440 }
441
442 static int reg_event_syscall_exit(struct trace_event_file *file,
443 struct trace_event_call *call)
444 {
445 struct trace_array *tr = file->tr;
446 int ret = 0;
447 int num;
448
449 num = ((struct syscall_metadata *)call->data)->syscall_nr;
450 if (WARN_ON_ONCE(num < 0 || num >= NR_syscalls))
451 return -ENOSYS;
452 mutex_lock(&syscall_trace_lock);
453 if (!tr->sys_refcount_exit)
454 ret = register_trace_sys_exit(ftrace_syscall_exit, tr);
455 if (!ret) {
456 rcu_assign_pointer(tr->exit_syscall_files[num], file);
457 tr->sys_refcount_exit++;
458 }
459 mutex_unlock(&syscall_trace_lock);
460 return ret;
461 }
462
463 static void unreg_event_syscall_exit(struct trace_event_file *file,
464 struct trace_event_call *call)
465 {
466 struct trace_array *tr = file->tr;
467 int num;
468
469 num = ((struct syscall_metadata *)call->data)->syscall_nr;
470 if (WARN_ON_ONCE(num < 0 || num >= NR_syscalls))
471 return;
472 mutex_lock(&syscall_trace_lock);
473 tr->sys_refcount_exit--;
474 RCU_INIT_POINTER(tr->exit_syscall_files[num], NULL);
475 if (!tr->sys_refcount_exit)
476 unregister_trace_sys_exit(ftrace_syscall_exit, tr);
477 mutex_unlock(&syscall_trace_lock);
478 }
479
480 static int __init init_syscall_trace(struct trace_event_call *call)
481 {
482 int id;
483 int num;
484
485 num = ((struct syscall_metadata *)call->data)->syscall_nr;
486 if (num < 0 || num >= NR_syscalls) {
487 pr_debug("syscall %s metadata not mapped, disabling ftrace event\n",
488 ((struct syscall_metadata *)call->data)->name);
489 return -ENOSYS;
490 }
491
492 if (set_syscall_print_fmt(call) < 0)
493 return -ENOMEM;
494
495 id = trace_event_raw_init(call);
496
497 if (id < 0) {
498 free_syscall_print_fmt(call);
499 return id;
500 }
501
502 return id;
503 }
504
505 struct trace_event_functions enter_syscall_print_funcs = {
506 .trace = print_syscall_enter,
507 };
508
509 struct trace_event_functions exit_syscall_print_funcs = {
510 .trace = print_syscall_exit,
511 };
512
513 struct trace_event_class __refdata event_class_syscall_enter = {
514 .system = "syscalls",
515 .reg = syscall_enter_register,
516 .define_fields = syscall_enter_define_fields,
517 .get_fields = syscall_get_enter_fields,
518 .raw_init = init_syscall_trace,
519 };
520
521 struct trace_event_class __refdata event_class_syscall_exit = {
522 .system = "syscalls",
523 .reg = syscall_exit_register,
524 .define_fields = syscall_exit_define_fields,
525 .fields = LIST_HEAD_INIT(event_class_syscall_exit.fields),
526 .raw_init = init_syscall_trace,
527 };
528
529 unsigned long __init __weak arch_syscall_addr(int nr)
530 {
531 return (unsigned long)sys_call_table[nr];
532 }
533
534 void __init init_ftrace_syscalls(void)
535 {
536 struct syscall_metadata *meta;
537 unsigned long addr;
538 int i;
539
540 syscalls_metadata = kcalloc(NR_syscalls, sizeof(*syscalls_metadata),
541 GFP_KERNEL);
542 if (!syscalls_metadata) {
543 WARN_ON(1);
544 return;
545 }
546
547 for (i = 0; i < NR_syscalls; i++) {
548 addr = arch_syscall_addr(i);
549 meta = find_syscall_meta(addr);
550 if (!meta)
551 continue;
552
553 meta->syscall_nr = i;
554 syscalls_metadata[i] = meta;
555 }
556 }
557
558 #ifdef CONFIG_PERF_EVENTS
559
560 static DECLARE_BITMAP(enabled_perf_enter_syscalls, NR_syscalls);
561 static DECLARE_BITMAP(enabled_perf_exit_syscalls, NR_syscalls);
562 static int sys_perf_refcount_enter;
563 static int sys_perf_refcount_exit;
564
565 static int perf_call_bpf_enter(struct trace_event_call *call, struct pt_regs *regs,
566 struct syscall_metadata *sys_data,
567 struct syscall_trace_enter *rec)
568 {
569 struct syscall_tp_t {
570 unsigned long long regs;
571 unsigned long syscall_nr;
572 unsigned long args[SYSCALL_DEFINE_MAXARGS];
573 } param;
574 int i;
575
576 *(struct pt_regs **)¶m = regs;
577 param.syscall_nr = rec->nr;
578 for (i = 0; i < sys_data->nb_args; i++)
579 param.args[i] = rec->args[i];
580 return trace_call_bpf(call, ¶m);
581 }
582
583 static void perf_syscall_enter(void *ignore, struct pt_regs *regs, long id)
584 {
585 struct syscall_metadata *sys_data;
586 struct syscall_trace_enter *rec;
587 struct hlist_head *head;
588 unsigned long args[6];
589 bool valid_prog_array;
590 int syscall_nr;
591 int rctx;
592 int size;
593
594 syscall_nr = trace_get_syscall_nr(current, regs);
595 if (syscall_nr < 0 || syscall_nr >= NR_syscalls)
596 return;
597 if (!test_bit(syscall_nr, enabled_perf_enter_syscalls))
598 return;
599
600 sys_data = syscall_nr_to_meta(syscall_nr);
601 if (!sys_data)
602 return;
603
604 head = this_cpu_ptr(sys_data->enter_event->perf_events);
605 valid_prog_array = bpf_prog_array_valid(sys_data->enter_event);
606 if (!valid_prog_array && hlist_empty(head))
607 return;
608
609
610 size = sizeof(unsigned long) * sys_data->nb_args + sizeof(*rec);
611 size = ALIGN(size + sizeof(u32), sizeof(u64));
612 size -= sizeof(u32);
613
614 rec = perf_trace_buf_alloc(size, NULL, &rctx);
615 if (!rec)
616 return;
617
618 rec->nr = syscall_nr;
619 syscall_get_arguments(current, regs, args);
620 memcpy(&rec->args, args, sizeof(unsigned long) * sys_data->nb_args);
621
622 if ((valid_prog_array &&
623 !perf_call_bpf_enter(sys_data->enter_event, regs, sys_data, rec)) ||
624 hlist_empty(head)) {
625 perf_swevent_put_recursion_context(rctx);
626 return;
627 }
628
629 perf_trace_buf_submit(rec, size, rctx,
630 sys_data->enter_event->event.type, 1, regs,
631 head, NULL);
632 }
633
634 static int perf_sysenter_enable(struct trace_event_call *call)
635 {
636 int ret = 0;
637 int num;
638
639 num = ((struct syscall_metadata *)call->data)->syscall_nr;
640
641 mutex_lock(&syscall_trace_lock);
642 if (!sys_perf_refcount_enter)
643 ret = register_trace_sys_enter(perf_syscall_enter, NULL);
644 if (ret) {
645 pr_info("event trace: Could not activate syscall entry trace point");
646 } else {
647 set_bit(num, enabled_perf_enter_syscalls);
648 sys_perf_refcount_enter++;
649 }
650 mutex_unlock(&syscall_trace_lock);
651 return ret;
652 }
653
654 static void perf_sysenter_disable(struct trace_event_call *call)
655 {
656 int num;
657
658 num = ((struct syscall_metadata *)call->data)->syscall_nr;
659
660 mutex_lock(&syscall_trace_lock);
661 sys_perf_refcount_enter--;
662 clear_bit(num, enabled_perf_enter_syscalls);
663 if (!sys_perf_refcount_enter)
664 unregister_trace_sys_enter(perf_syscall_enter, NULL);
665 mutex_unlock(&syscall_trace_lock);
666 }
667
668 static int perf_call_bpf_exit(struct trace_event_call *call, struct pt_regs *regs,
669 struct syscall_trace_exit *rec)
670 {
671 struct syscall_tp_t {
672 unsigned long long regs;
673 unsigned long syscall_nr;
674 unsigned long ret;
675 } param;
676
677 *(struct pt_regs **)¶m = regs;
678 param.syscall_nr = rec->nr;
679 param.ret = rec->ret;
680 return trace_call_bpf(call, ¶m);
681 }
682
683 static void perf_syscall_exit(void *ignore, struct pt_regs *regs, long ret)
684 {
685 struct syscall_metadata *sys_data;
686 struct syscall_trace_exit *rec;
687 struct hlist_head *head;
688 bool valid_prog_array;
689 int syscall_nr;
690 int rctx;
691 int size;
692
693 syscall_nr = trace_get_syscall_nr(current, regs);
694 if (syscall_nr < 0 || syscall_nr >= NR_syscalls)
695 return;
696 if (!test_bit(syscall_nr, enabled_perf_exit_syscalls))
697 return;
698
699 sys_data = syscall_nr_to_meta(syscall_nr);
700 if (!sys_data)
701 return;
702
703 head = this_cpu_ptr(sys_data->exit_event->perf_events);
704 valid_prog_array = bpf_prog_array_valid(sys_data->exit_event);
705 if (!valid_prog_array && hlist_empty(head))
706 return;
707
708
709 size = ALIGN(sizeof(*rec) + sizeof(u32), sizeof(u64));
710 size -= sizeof(u32);
711
712 rec = perf_trace_buf_alloc(size, NULL, &rctx);
713 if (!rec)
714 return;
715
716 rec->nr = syscall_nr;
717 rec->ret = syscall_get_return_value(current, regs);
718
719 if ((valid_prog_array &&
720 !perf_call_bpf_exit(sys_data->exit_event, regs, rec)) ||
721 hlist_empty(head)) {
722 perf_swevent_put_recursion_context(rctx);
723 return;
724 }
725
726 perf_trace_buf_submit(rec, size, rctx, sys_data->exit_event->event.type,
727 1, regs, head, NULL);
728 }
729
730 static int perf_sysexit_enable(struct trace_event_call *call)
731 {
732 int ret = 0;
733 int num;
734
735 num = ((struct syscall_metadata *)call->data)->syscall_nr;
736
737 mutex_lock(&syscall_trace_lock);
738 if (!sys_perf_refcount_exit)
739 ret = register_trace_sys_exit(perf_syscall_exit, NULL);
740 if (ret) {
741 pr_info("event trace: Could not activate syscall exit trace point");
742 } else {
743 set_bit(num, enabled_perf_exit_syscalls);
744 sys_perf_refcount_exit++;
745 }
746 mutex_unlock(&syscall_trace_lock);
747 return ret;
748 }
749
750 static void perf_sysexit_disable(struct trace_event_call *call)
751 {
752 int num;
753
754 num = ((struct syscall_metadata *)call->data)->syscall_nr;
755
756 mutex_lock(&syscall_trace_lock);
757 sys_perf_refcount_exit--;
758 clear_bit(num, enabled_perf_exit_syscalls);
759 if (!sys_perf_refcount_exit)
760 unregister_trace_sys_exit(perf_syscall_exit, NULL);
761 mutex_unlock(&syscall_trace_lock);
762 }
763
764 #endif
765
766 static int syscall_enter_register(struct trace_event_call *event,
767 enum trace_reg type, void *data)
768 {
769 struct trace_event_file *file = data;
770
771 switch (type) {
772 case TRACE_REG_REGISTER:
773 return reg_event_syscall_enter(file, event);
774 case TRACE_REG_UNREGISTER:
775 unreg_event_syscall_enter(file, event);
776 return 0;
777
778 #ifdef CONFIG_PERF_EVENTS
779 case TRACE_REG_PERF_REGISTER:
780 return perf_sysenter_enable(event);
781 case TRACE_REG_PERF_UNREGISTER:
782 perf_sysenter_disable(event);
783 return 0;
784 case TRACE_REG_PERF_OPEN:
785 case TRACE_REG_PERF_CLOSE:
786 case TRACE_REG_PERF_ADD:
787 case TRACE_REG_PERF_DEL:
788 return 0;
789 #endif
790 }
791 return 0;
792 }
793
794 static int syscall_exit_register(struct trace_event_call *event,
795 enum trace_reg type, void *data)
796 {
797 struct trace_event_file *file = data;
798
799 switch (type) {
800 case TRACE_REG_REGISTER:
801 return reg_event_syscall_exit(file, event);
802 case TRACE_REG_UNREGISTER:
803 unreg_event_syscall_exit(file, event);
804 return 0;
805
806 #ifdef CONFIG_PERF_EVENTS
807 case TRACE_REG_PERF_REGISTER:
808 return perf_sysexit_enable(event);
809 case TRACE_REG_PERF_UNREGISTER:
810 perf_sysexit_disable(event);
811 return 0;
812 case TRACE_REG_PERF_OPEN:
813 case TRACE_REG_PERF_CLOSE:
814 case TRACE_REG_PERF_ADD:
815 case TRACE_REG_PERF_DEL:
816 return 0;
817 #endif
818 }
819 return 0;
820 }