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1// SPDX-License-Identifier: GPL-2.0
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> /* for MODULE_NAME_LEN via KSYM_SYMBOL_LEN */
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
15static DEFINE_MUTEX(syscall_trace_lock);
16
17static int syscall_enter_register(struct trace_event_call *event,
18 enum trace_reg type, void *data);
19static int syscall_exit_register(struct trace_event_call *event,
20 enum trace_reg type, void *data);
21
22static struct list_head *
23syscall_get_enter_fields(struct trace_event_call *call)
24{
25 struct syscall_metadata *entry = call->data;
26
27 return &entry->enter_fields;
28}
29
30extern struct syscall_metadata *__start_syscalls_metadata[];
31extern struct syscall_metadata *__stop_syscalls_metadata[];
32
33static struct syscall_metadata **syscalls_metadata;
34
35#ifndef ARCH_HAS_SYSCALL_MATCH_SYM_NAME
36static inline bool arch_syscall_match_sym_name(const char *sym, const char *name)
37{
38 /*
39 * Only compare after the "sys" prefix. Archs that use
40 * syscall wrappers may have syscalls symbols aliases prefixed
41 * with ".SyS" or ".sys" instead of "sys", leading to an unwanted
42 * mismatch.
43 */
44 return !strcmp(sym + 3, name + 3);
45}
46#endif
47
48#ifdef ARCH_TRACE_IGNORE_COMPAT_SYSCALLS
49/*
50 * Some architectures that allow for 32bit applications
51 * to run on a 64bit kernel, do not map the syscalls for
52 * the 32bit tasks the same as they do for 64bit tasks.
53 *
54 * *cough*x86*cough*
55 *
56 * In such a case, instead of reporting the wrong syscalls,
57 * simply ignore them.
58 *
59 * For an arch to ignore the compat syscalls it needs to
60 * define ARCH_TRACE_IGNORE_COMPAT_SYSCALLS as well as
61 * define the function arch_trace_is_compat_syscall() to let
62 * the tracing system know that it should ignore it.
63 */
64static int
65trace_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
73static inline int
74trace_get_syscall_nr(struct task_struct *task, struct pt_regs *regs)
75{
76 return syscall_get_nr(task, regs);
77}
78#endif /* ARCH_TRACE_IGNORE_COMPAT_SYSCALLS */
79
80static __init struct syscall_metadata *
81find_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
102static 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
110const 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
121static enum print_line_t
122print_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 /* parameter types */
152 if (tr->trace_flags & TRACE_ITER_VERBOSE)
153 trace_seq_printf(s, "%s ", entry->types[i]);
154
155 /* parameter values */
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, ')');
162end:
163 trace_seq_putc(s, '\n');
164
165 return trace_handle_return(s);
166}
167
168static enum print_line_t
169print_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
199extern 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
207static 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 /* When len=0, we just calculate the needed length */
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 /* return the length of print_fmt */
232 return pos;
233}
234
235static 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 /* First: called with 0 length to calculate the needed length */
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 /* Second: actually write the @print_fmt */
254 __set_enter_print_fmt(entry, print_fmt, len + 1);
255 call->print_fmt = print_fmt;
256
257 return 0;
258}
259
260static 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
268static 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
292static 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
308static 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 int pc;
318 int syscall_nr;
319 int size;
320
321 syscall_nr = trace_get_syscall_nr(current, regs);
322 if (syscall_nr < 0 || syscall_nr >= NR_syscalls)
323 return;
324
325 /* Here we're inside tp handler's rcu_read_lock_sched (__DO_TRACE) */
326 trace_file = rcu_dereference_sched(tr->enter_syscall_files[syscall_nr]);
327 if (!trace_file)
328 return;
329
330 if (trace_trigger_soft_disabled(trace_file))
331 return;
332
333 sys_data = syscall_nr_to_meta(syscall_nr);
334 if (!sys_data)
335 return;
336
337 size = sizeof(*entry) + sizeof(unsigned long) * sys_data->nb_args;
338
339 local_save_flags(irq_flags);
340 pc = preempt_count();
341
342 buffer = tr->trace_buffer.buffer;
343 event = trace_buffer_lock_reserve(buffer,
344 sys_data->enter_event->event.type, size, irq_flags, pc);
345 if (!event)
346 return;
347
348 entry = ring_buffer_event_data(event);
349 entry->nr = syscall_nr;
350 syscall_get_arguments(current, regs, 0, sys_data->nb_args, entry->args);
351
352 event_trigger_unlock_commit(trace_file, buffer, event, entry,
353 irq_flags, pc);
354}
355
356static void ftrace_syscall_exit(void *data, struct pt_regs *regs, long ret)
357{
358 struct trace_array *tr = data;
359 struct trace_event_file *trace_file;
360 struct syscall_trace_exit *entry;
361 struct syscall_metadata *sys_data;
362 struct ring_buffer_event *event;
363 struct ring_buffer *buffer;
364 unsigned long irq_flags;
365 int pc;
366 int syscall_nr;
367
368 syscall_nr = trace_get_syscall_nr(current, regs);
369 if (syscall_nr < 0 || syscall_nr >= NR_syscalls)
370 return;
371
372 /* Here we're inside tp handler's rcu_read_lock_sched (__DO_TRACE()) */
373 trace_file = rcu_dereference_sched(tr->exit_syscall_files[syscall_nr]);
374 if (!trace_file)
375 return;
376
377 if (trace_trigger_soft_disabled(trace_file))
378 return;
379
380 sys_data = syscall_nr_to_meta(syscall_nr);
381 if (!sys_data)
382 return;
383
384 local_save_flags(irq_flags);
385 pc = preempt_count();
386
387 buffer = tr->trace_buffer.buffer;
388 event = trace_buffer_lock_reserve(buffer,
389 sys_data->exit_event->event.type, sizeof(*entry),
390 irq_flags, pc);
391 if (!event)
392 return;
393
394 entry = ring_buffer_event_data(event);
395 entry->nr = syscall_nr;
396 entry->ret = syscall_get_return_value(current, regs);
397
398 event_trigger_unlock_commit(trace_file, buffer, event, entry,
399 irq_flags, pc);
400}
401
402static int reg_event_syscall_enter(struct trace_event_file *file,
403 struct trace_event_call *call)
404{
405 struct trace_array *tr = file->tr;
406 int ret = 0;
407 int num;
408
409 num = ((struct syscall_metadata *)call->data)->syscall_nr;
410 if (WARN_ON_ONCE(num < 0 || num >= NR_syscalls))
411 return -ENOSYS;
412 mutex_lock(&syscall_trace_lock);
413 if (!tr->sys_refcount_enter)
414 ret = register_trace_sys_enter(ftrace_syscall_enter, tr);
415 if (!ret) {
416 rcu_assign_pointer(tr->enter_syscall_files[num], file);
417 tr->sys_refcount_enter++;
418 }
419 mutex_unlock(&syscall_trace_lock);
420 return ret;
421}
422
423static void unreg_event_syscall_enter(struct trace_event_file *file,
424 struct trace_event_call *call)
425{
426 struct trace_array *tr = file->tr;
427 int num;
428
429 num = ((struct syscall_metadata *)call->data)->syscall_nr;
430 if (WARN_ON_ONCE(num < 0 || num >= NR_syscalls))
431 return;
432 mutex_lock(&syscall_trace_lock);
433 tr->sys_refcount_enter--;
434 RCU_INIT_POINTER(tr->enter_syscall_files[num], NULL);
435 if (!tr->sys_refcount_enter)
436 unregister_trace_sys_enter(ftrace_syscall_enter, tr);
437 mutex_unlock(&syscall_trace_lock);
438}
439
440static int reg_event_syscall_exit(struct trace_event_file *file,
441 struct trace_event_call *call)
442{
443 struct trace_array *tr = file->tr;
444 int ret = 0;
445 int num;
446
447 num = ((struct syscall_metadata *)call->data)->syscall_nr;
448 if (WARN_ON_ONCE(num < 0 || num >= NR_syscalls))
449 return -ENOSYS;
450 mutex_lock(&syscall_trace_lock);
451 if (!tr->sys_refcount_exit)
452 ret = register_trace_sys_exit(ftrace_syscall_exit, tr);
453 if (!ret) {
454 rcu_assign_pointer(tr->exit_syscall_files[num], file);
455 tr->sys_refcount_exit++;
456 }
457 mutex_unlock(&syscall_trace_lock);
458 return ret;
459}
460
461static void unreg_event_syscall_exit(struct trace_event_file *file,
462 struct trace_event_call *call)
463{
464 struct trace_array *tr = file->tr;
465 int num;
466
467 num = ((struct syscall_metadata *)call->data)->syscall_nr;
468 if (WARN_ON_ONCE(num < 0 || num >= NR_syscalls))
469 return;
470 mutex_lock(&syscall_trace_lock);
471 tr->sys_refcount_exit--;
472 RCU_INIT_POINTER(tr->exit_syscall_files[num], NULL);
473 if (!tr->sys_refcount_exit)
474 unregister_trace_sys_exit(ftrace_syscall_exit, tr);
475 mutex_unlock(&syscall_trace_lock);
476}
477
478static int __init init_syscall_trace(struct trace_event_call *call)
479{
480 int id;
481 int num;
482
483 num = ((struct syscall_metadata *)call->data)->syscall_nr;
484 if (num < 0 || num >= NR_syscalls) {
485 pr_debug("syscall %s metadata not mapped, disabling ftrace event\n",
486 ((struct syscall_metadata *)call->data)->name);
487 return -ENOSYS;
488 }
489
490 if (set_syscall_print_fmt(call) < 0)
491 return -ENOMEM;
492
493 id = trace_event_raw_init(call);
494
495 if (id < 0) {
496 free_syscall_print_fmt(call);
497 return id;
498 }
499
500 return id;
501}
502
503struct trace_event_functions enter_syscall_print_funcs = {
504 .trace = print_syscall_enter,
505};
506
507struct trace_event_functions exit_syscall_print_funcs = {
508 .trace = print_syscall_exit,
509};
510
511struct trace_event_class __refdata event_class_syscall_enter = {
512 .system = "syscalls",
513 .reg = syscall_enter_register,
514 .define_fields = syscall_enter_define_fields,
515 .get_fields = syscall_get_enter_fields,
516 .raw_init = init_syscall_trace,
517};
518
519struct trace_event_class __refdata event_class_syscall_exit = {
520 .system = "syscalls",
521 .reg = syscall_exit_register,
522 .define_fields = syscall_exit_define_fields,
523 .fields = LIST_HEAD_INIT(event_class_syscall_exit.fields),
524 .raw_init = init_syscall_trace,
525};
526
527unsigned long __init __weak arch_syscall_addr(int nr)
528{
529 return (unsigned long)sys_call_table[nr];
530}
531
532void __init init_ftrace_syscalls(void)
533{
534 struct syscall_metadata *meta;
535 unsigned long addr;
536 int i;
537
538 syscalls_metadata = kcalloc(NR_syscalls, sizeof(*syscalls_metadata),
539 GFP_KERNEL);
540 if (!syscalls_metadata) {
541 WARN_ON(1);
542 return;
543 }
544
545 for (i = 0; i < NR_syscalls; i++) {
546 addr = arch_syscall_addr(i);
547 meta = find_syscall_meta(addr);
548 if (!meta)
549 continue;
550
551 meta->syscall_nr = i;
552 syscalls_metadata[i] = meta;
553 }
554}
555
556#ifdef CONFIG_PERF_EVENTS
557
558static DECLARE_BITMAP(enabled_perf_enter_syscalls, NR_syscalls);
559static DECLARE_BITMAP(enabled_perf_exit_syscalls, NR_syscalls);
560static int sys_perf_refcount_enter;
561static int sys_perf_refcount_exit;
562
563static int perf_call_bpf_enter(struct trace_event_call *call, struct pt_regs *regs,
564 struct syscall_metadata *sys_data,
565 struct syscall_trace_enter *rec)
566{
567 struct syscall_tp_t {
568 unsigned long long regs;
569 unsigned long syscall_nr;
570 unsigned long args[SYSCALL_DEFINE_MAXARGS];
571 } param;
572 int i;
573
574 *(struct pt_regs **)¶m = regs;
575 param.syscall_nr = rec->nr;
576 for (i = 0; i < sys_data->nb_args; i++)
577 param.args[i] = rec->args[i];
578 return trace_call_bpf(call, ¶m);
579}
580
581static void perf_syscall_enter(void *ignore, struct pt_regs *regs, long id)
582{
583 struct syscall_metadata *sys_data;
584 struct syscall_trace_enter *rec;
585 struct hlist_head *head;
586 bool valid_prog_array;
587 int syscall_nr;
588 int rctx;
589 int size;
590
591 syscall_nr = trace_get_syscall_nr(current, regs);
592 if (syscall_nr < 0 || syscall_nr >= NR_syscalls)
593 return;
594 if (!test_bit(syscall_nr, enabled_perf_enter_syscalls))
595 return;
596
597 sys_data = syscall_nr_to_meta(syscall_nr);
598 if (!sys_data)
599 return;
600
601 head = this_cpu_ptr(sys_data->enter_event->perf_events);
602 valid_prog_array = bpf_prog_array_valid(sys_data->enter_event);
603 if (!valid_prog_array && hlist_empty(head))
604 return;
605
606 /* get the size after alignment with the u32 buffer size field */
607 size = sizeof(unsigned long) * sys_data->nb_args + sizeof(*rec);
608 size = ALIGN(size + sizeof(u32), sizeof(u64));
609 size -= sizeof(u32);
610
611 rec = perf_trace_buf_alloc(size, NULL, &rctx);
612 if (!rec)
613 return;
614
615 rec->nr = syscall_nr;
616 syscall_get_arguments(current, regs, 0, sys_data->nb_args,
617 (unsigned long *)&rec->args);
618
619 if ((valid_prog_array &&
620 !perf_call_bpf_enter(sys_data->enter_event, regs, sys_data, rec)) ||
621 hlist_empty(head)) {
622 perf_swevent_put_recursion_context(rctx);
623 return;
624 }
625
626 perf_trace_buf_submit(rec, size, rctx,
627 sys_data->enter_event->event.type, 1, regs,
628 head, NULL);
629}
630
631static int perf_sysenter_enable(struct trace_event_call *call)
632{
633 int ret = 0;
634 int num;
635
636 num = ((struct syscall_metadata *)call->data)->syscall_nr;
637
638 mutex_lock(&syscall_trace_lock);
639 if (!sys_perf_refcount_enter)
640 ret = register_trace_sys_enter(perf_syscall_enter, NULL);
641 if (ret) {
642 pr_info("event trace: Could not activate syscall entry trace point");
643 } else {
644 set_bit(num, enabled_perf_enter_syscalls);
645 sys_perf_refcount_enter++;
646 }
647 mutex_unlock(&syscall_trace_lock);
648 return ret;
649}
650
651static void perf_sysenter_disable(struct trace_event_call *call)
652{
653 int num;
654
655 num = ((struct syscall_metadata *)call->data)->syscall_nr;
656
657 mutex_lock(&syscall_trace_lock);
658 sys_perf_refcount_enter--;
659 clear_bit(num, enabled_perf_enter_syscalls);
660 if (!sys_perf_refcount_enter)
661 unregister_trace_sys_enter(perf_syscall_enter, NULL);
662 mutex_unlock(&syscall_trace_lock);
663}
664
665static int perf_call_bpf_exit(struct trace_event_call *call, struct pt_regs *regs,
666 struct syscall_trace_exit *rec)
667{
668 struct syscall_tp_t {
669 unsigned long long regs;
670 unsigned long syscall_nr;
671 unsigned long ret;
672 } param;
673
674 *(struct pt_regs **)¶m = regs;
675 param.syscall_nr = rec->nr;
676 param.ret = rec->ret;
677 return trace_call_bpf(call, ¶m);
678}
679
680static void perf_syscall_exit(void *ignore, struct pt_regs *regs, long ret)
681{
682 struct syscall_metadata *sys_data;
683 struct syscall_trace_exit *rec;
684 struct hlist_head *head;
685 bool valid_prog_array;
686 int syscall_nr;
687 int rctx;
688 int size;
689
690 syscall_nr = trace_get_syscall_nr(current, regs);
691 if (syscall_nr < 0 || syscall_nr >= NR_syscalls)
692 return;
693 if (!test_bit(syscall_nr, enabled_perf_exit_syscalls))
694 return;
695
696 sys_data = syscall_nr_to_meta(syscall_nr);
697 if (!sys_data)
698 return;
699
700 head = this_cpu_ptr(sys_data->exit_event->perf_events);
701 valid_prog_array = bpf_prog_array_valid(sys_data->exit_event);
702 if (!valid_prog_array && hlist_empty(head))
703 return;
704
705 /* We can probably do that at build time */
706 size = ALIGN(sizeof(*rec) + sizeof(u32), sizeof(u64));
707 size -= sizeof(u32);
708
709 rec = perf_trace_buf_alloc(size, NULL, &rctx);
710 if (!rec)
711 return;
712
713 rec->nr = syscall_nr;
714 rec->ret = syscall_get_return_value(current, regs);
715
716 if ((valid_prog_array &&
717 !perf_call_bpf_exit(sys_data->exit_event, regs, rec)) ||
718 hlist_empty(head)) {
719 perf_swevent_put_recursion_context(rctx);
720 return;
721 }
722
723 perf_trace_buf_submit(rec, size, rctx, sys_data->exit_event->event.type,
724 1, regs, head, NULL);
725}
726
727static int perf_sysexit_enable(struct trace_event_call *call)
728{
729 int ret = 0;
730 int num;
731
732 num = ((struct syscall_metadata *)call->data)->syscall_nr;
733
734 mutex_lock(&syscall_trace_lock);
735 if (!sys_perf_refcount_exit)
736 ret = register_trace_sys_exit(perf_syscall_exit, NULL);
737 if (ret) {
738 pr_info("event trace: Could not activate syscall exit trace point");
739 } else {
740 set_bit(num, enabled_perf_exit_syscalls);
741 sys_perf_refcount_exit++;
742 }
743 mutex_unlock(&syscall_trace_lock);
744 return ret;
745}
746
747static void perf_sysexit_disable(struct trace_event_call *call)
748{
749 int num;
750
751 num = ((struct syscall_metadata *)call->data)->syscall_nr;
752
753 mutex_lock(&syscall_trace_lock);
754 sys_perf_refcount_exit--;
755 clear_bit(num, enabled_perf_exit_syscalls);
756 if (!sys_perf_refcount_exit)
757 unregister_trace_sys_exit(perf_syscall_exit, NULL);
758 mutex_unlock(&syscall_trace_lock);
759}
760
761#endif /* CONFIG_PERF_EVENTS */
762
763static int syscall_enter_register(struct trace_event_call *event,
764 enum trace_reg type, void *data)
765{
766 struct trace_event_file *file = data;
767
768 switch (type) {
769 case TRACE_REG_REGISTER:
770 return reg_event_syscall_enter(file, event);
771 case TRACE_REG_UNREGISTER:
772 unreg_event_syscall_enter(file, event);
773 return 0;
774
775#ifdef CONFIG_PERF_EVENTS
776 case TRACE_REG_PERF_REGISTER:
777 return perf_sysenter_enable(event);
778 case TRACE_REG_PERF_UNREGISTER:
779 perf_sysenter_disable(event);
780 return 0;
781 case TRACE_REG_PERF_OPEN:
782 case TRACE_REG_PERF_CLOSE:
783 case TRACE_REG_PERF_ADD:
784 case TRACE_REG_PERF_DEL:
785 return 0;
786#endif
787 }
788 return 0;
789}
790
791static int syscall_exit_register(struct trace_event_call *event,
792 enum trace_reg type, void *data)
793{
794 struct trace_event_file *file = data;
795
796 switch (type) {
797 case TRACE_REG_REGISTER:
798 return reg_event_syscall_exit(file, event);
799 case TRACE_REG_UNREGISTER:
800 unreg_event_syscall_exit(file, event);
801 return 0;
802
803#ifdef CONFIG_PERF_EVENTS
804 case TRACE_REG_PERF_REGISTER:
805 return perf_sysexit_enable(event);
806 case TRACE_REG_PERF_UNREGISTER:
807 perf_sysexit_disable(event);
808 return 0;
809 case TRACE_REG_PERF_OPEN:
810 case TRACE_REG_PERF_CLOSE:
811 case TRACE_REG_PERF_ADD:
812 case TRACE_REG_PERF_DEL:
813 return 0;
814#endif
815 }
816 return 0;
817}
1#include <trace/syscall.h>
2#include <trace/events/syscalls.h>
3#include <linux/slab.h>
4#include <linux/kernel.h>
5#include <linux/ftrace.h>
6#include <linux/perf_event.h>
7#include <asm/syscall.h>
8
9#include "trace_output.h"
10#include "trace.h"
11
12static DEFINE_MUTEX(syscall_trace_lock);
13static int sys_refcount_enter;
14static int sys_refcount_exit;
15static DECLARE_BITMAP(enabled_enter_syscalls, NR_syscalls);
16static DECLARE_BITMAP(enabled_exit_syscalls, NR_syscalls);
17
18static int syscall_enter_register(struct ftrace_event_call *event,
19 enum trace_reg type);
20static int syscall_exit_register(struct ftrace_event_call *event,
21 enum trace_reg type);
22
23static int syscall_enter_define_fields(struct ftrace_event_call *call);
24static int syscall_exit_define_fields(struct ftrace_event_call *call);
25
26static struct list_head *
27syscall_get_enter_fields(struct ftrace_event_call *call)
28{
29 struct syscall_metadata *entry = call->data;
30
31 return &entry->enter_fields;
32}
33
34struct trace_event_functions enter_syscall_print_funcs = {
35 .trace = print_syscall_enter,
36};
37
38struct trace_event_functions exit_syscall_print_funcs = {
39 .trace = print_syscall_exit,
40};
41
42struct ftrace_event_class event_class_syscall_enter = {
43 .system = "syscalls",
44 .reg = syscall_enter_register,
45 .define_fields = syscall_enter_define_fields,
46 .get_fields = syscall_get_enter_fields,
47 .raw_init = init_syscall_trace,
48};
49
50struct ftrace_event_class event_class_syscall_exit = {
51 .system = "syscalls",
52 .reg = syscall_exit_register,
53 .define_fields = syscall_exit_define_fields,
54 .fields = LIST_HEAD_INIT(event_class_syscall_exit.fields),
55 .raw_init = init_syscall_trace,
56};
57
58extern struct syscall_metadata *__start_syscalls_metadata[];
59extern struct syscall_metadata *__stop_syscalls_metadata[];
60
61static struct syscall_metadata **syscalls_metadata;
62
63#ifndef ARCH_HAS_SYSCALL_MATCH_SYM_NAME
64static inline bool arch_syscall_match_sym_name(const char *sym, const char *name)
65{
66 /*
67 * Only compare after the "sys" prefix. Archs that use
68 * syscall wrappers may have syscalls symbols aliases prefixed
69 * with "SyS" instead of "sys", leading to an unwanted
70 * mismatch.
71 */
72 return !strcmp(sym + 3, name + 3);
73}
74#endif
75
76static __init struct syscall_metadata *
77find_syscall_meta(unsigned long syscall)
78{
79 struct syscall_metadata **start;
80 struct syscall_metadata **stop;
81 char str[KSYM_SYMBOL_LEN];
82
83
84 start = __start_syscalls_metadata;
85 stop = __stop_syscalls_metadata;
86 kallsyms_lookup(syscall, NULL, NULL, NULL, str);
87
88 if (arch_syscall_match_sym_name(str, "sys_ni_syscall"))
89 return NULL;
90
91 for ( ; start < stop; start++) {
92 if ((*start)->name && arch_syscall_match_sym_name(str, (*start)->name))
93 return *start;
94 }
95 return NULL;
96}
97
98static struct syscall_metadata *syscall_nr_to_meta(int nr)
99{
100 if (!syscalls_metadata || nr >= NR_syscalls || nr < 0)
101 return NULL;
102
103 return syscalls_metadata[nr];
104}
105
106enum print_line_t
107print_syscall_enter(struct trace_iterator *iter, int flags,
108 struct trace_event *event)
109{
110 struct trace_seq *s = &iter->seq;
111 struct trace_entry *ent = iter->ent;
112 struct syscall_trace_enter *trace;
113 struct syscall_metadata *entry;
114 int i, ret, syscall;
115
116 trace = (typeof(trace))ent;
117 syscall = trace->nr;
118 entry = syscall_nr_to_meta(syscall);
119
120 if (!entry)
121 goto end;
122
123 if (entry->enter_event->event.type != ent->type) {
124 WARN_ON_ONCE(1);
125 goto end;
126 }
127
128 ret = trace_seq_printf(s, "%s(", entry->name);
129 if (!ret)
130 return TRACE_TYPE_PARTIAL_LINE;
131
132 for (i = 0; i < entry->nb_args; i++) {
133 /* parameter types */
134 if (trace_flags & TRACE_ITER_VERBOSE) {
135 ret = trace_seq_printf(s, "%s ", entry->types[i]);
136 if (!ret)
137 return TRACE_TYPE_PARTIAL_LINE;
138 }
139 /* parameter values */
140 ret = trace_seq_printf(s, "%s: %lx%s", entry->args[i],
141 trace->args[i],
142 i == entry->nb_args - 1 ? "" : ", ");
143 if (!ret)
144 return TRACE_TYPE_PARTIAL_LINE;
145 }
146
147 ret = trace_seq_putc(s, ')');
148 if (!ret)
149 return TRACE_TYPE_PARTIAL_LINE;
150
151end:
152 ret = trace_seq_putc(s, '\n');
153 if (!ret)
154 return TRACE_TYPE_PARTIAL_LINE;
155
156 return TRACE_TYPE_HANDLED;
157}
158
159enum print_line_t
160print_syscall_exit(struct trace_iterator *iter, int flags,
161 struct trace_event *event)
162{
163 struct trace_seq *s = &iter->seq;
164 struct trace_entry *ent = iter->ent;
165 struct syscall_trace_exit *trace;
166 int syscall;
167 struct syscall_metadata *entry;
168 int ret;
169
170 trace = (typeof(trace))ent;
171 syscall = trace->nr;
172 entry = syscall_nr_to_meta(syscall);
173
174 if (!entry) {
175 trace_seq_printf(s, "\n");
176 return TRACE_TYPE_HANDLED;
177 }
178
179 if (entry->exit_event->event.type != ent->type) {
180 WARN_ON_ONCE(1);
181 return TRACE_TYPE_UNHANDLED;
182 }
183
184 ret = trace_seq_printf(s, "%s -> 0x%lx\n", entry->name,
185 trace->ret);
186 if (!ret)
187 return TRACE_TYPE_PARTIAL_LINE;
188
189 return TRACE_TYPE_HANDLED;
190}
191
192extern char *__bad_type_size(void);
193
194#define SYSCALL_FIELD(type, name) \
195 sizeof(type) != sizeof(trace.name) ? \
196 __bad_type_size() : \
197 #type, #name, offsetof(typeof(trace), name), \
198 sizeof(trace.name), is_signed_type(type)
199
200static
201int __set_enter_print_fmt(struct syscall_metadata *entry, char *buf, int len)
202{
203 int i;
204 int pos = 0;
205
206 /* When len=0, we just calculate the needed length */
207#define LEN_OR_ZERO (len ? len - pos : 0)
208
209 pos += snprintf(buf + pos, LEN_OR_ZERO, "\"");
210 for (i = 0; i < entry->nb_args; i++) {
211 pos += snprintf(buf + pos, LEN_OR_ZERO, "%s: 0x%%0%zulx%s",
212 entry->args[i], sizeof(unsigned long),
213 i == entry->nb_args - 1 ? "" : ", ");
214 }
215 pos += snprintf(buf + pos, LEN_OR_ZERO, "\"");
216
217 for (i = 0; i < entry->nb_args; i++) {
218 pos += snprintf(buf + pos, LEN_OR_ZERO,
219 ", ((unsigned long)(REC->%s))", entry->args[i]);
220 }
221
222#undef LEN_OR_ZERO
223
224 /* return the length of print_fmt */
225 return pos;
226}
227
228static int set_syscall_print_fmt(struct ftrace_event_call *call)
229{
230 char *print_fmt;
231 int len;
232 struct syscall_metadata *entry = call->data;
233
234 if (entry->enter_event != call) {
235 call->print_fmt = "\"0x%lx\", REC->ret";
236 return 0;
237 }
238
239 /* First: called with 0 length to calculate the needed length */
240 len = __set_enter_print_fmt(entry, NULL, 0);
241
242 print_fmt = kmalloc(len + 1, GFP_KERNEL);
243 if (!print_fmt)
244 return -ENOMEM;
245
246 /* Second: actually write the @print_fmt */
247 __set_enter_print_fmt(entry, print_fmt, len + 1);
248 call->print_fmt = print_fmt;
249
250 return 0;
251}
252
253static void free_syscall_print_fmt(struct ftrace_event_call *call)
254{
255 struct syscall_metadata *entry = call->data;
256
257 if (entry->enter_event == call)
258 kfree(call->print_fmt);
259}
260
261static int syscall_enter_define_fields(struct ftrace_event_call *call)
262{
263 struct syscall_trace_enter trace;
264 struct syscall_metadata *meta = call->data;
265 int ret;
266 int i;
267 int offset = offsetof(typeof(trace), args);
268
269 ret = trace_define_field(call, SYSCALL_FIELD(int, nr), FILTER_OTHER);
270 if (ret)
271 return ret;
272
273 for (i = 0; i < meta->nb_args; i++) {
274 ret = trace_define_field(call, meta->types[i],
275 meta->args[i], offset,
276 sizeof(unsigned long), 0,
277 FILTER_OTHER);
278 offset += sizeof(unsigned long);
279 }
280
281 return ret;
282}
283
284static int syscall_exit_define_fields(struct ftrace_event_call *call)
285{
286 struct syscall_trace_exit trace;
287 int ret;
288
289 ret = trace_define_field(call, SYSCALL_FIELD(int, nr), FILTER_OTHER);
290 if (ret)
291 return ret;
292
293 ret = trace_define_field(call, SYSCALL_FIELD(long, ret),
294 FILTER_OTHER);
295
296 return ret;
297}
298
299void ftrace_syscall_enter(void *ignore, struct pt_regs *regs, long id)
300{
301 struct syscall_trace_enter *entry;
302 struct syscall_metadata *sys_data;
303 struct ring_buffer_event *event;
304 struct ring_buffer *buffer;
305 int size;
306 int syscall_nr;
307
308 syscall_nr = syscall_get_nr(current, regs);
309 if (syscall_nr < 0)
310 return;
311 if (!test_bit(syscall_nr, enabled_enter_syscalls))
312 return;
313
314 sys_data = syscall_nr_to_meta(syscall_nr);
315 if (!sys_data)
316 return;
317
318 size = sizeof(*entry) + sizeof(unsigned long) * sys_data->nb_args;
319
320 event = trace_current_buffer_lock_reserve(&buffer,
321 sys_data->enter_event->event.type, size, 0, 0);
322 if (!event)
323 return;
324
325 entry = ring_buffer_event_data(event);
326 entry->nr = syscall_nr;
327 syscall_get_arguments(current, regs, 0, sys_data->nb_args, entry->args);
328
329 if (!filter_current_check_discard(buffer, sys_data->enter_event,
330 entry, event))
331 trace_current_buffer_unlock_commit(buffer, event, 0, 0);
332}
333
334void ftrace_syscall_exit(void *ignore, struct pt_regs *regs, long ret)
335{
336 struct syscall_trace_exit *entry;
337 struct syscall_metadata *sys_data;
338 struct ring_buffer_event *event;
339 struct ring_buffer *buffer;
340 int syscall_nr;
341
342 syscall_nr = syscall_get_nr(current, regs);
343 if (syscall_nr < 0)
344 return;
345 if (!test_bit(syscall_nr, enabled_exit_syscalls))
346 return;
347
348 sys_data = syscall_nr_to_meta(syscall_nr);
349 if (!sys_data)
350 return;
351
352 event = trace_current_buffer_lock_reserve(&buffer,
353 sys_data->exit_event->event.type, sizeof(*entry), 0, 0);
354 if (!event)
355 return;
356
357 entry = ring_buffer_event_data(event);
358 entry->nr = syscall_nr;
359 entry->ret = syscall_get_return_value(current, regs);
360
361 if (!filter_current_check_discard(buffer, sys_data->exit_event,
362 entry, event))
363 trace_current_buffer_unlock_commit(buffer, event, 0, 0);
364}
365
366int reg_event_syscall_enter(struct ftrace_event_call *call)
367{
368 int ret = 0;
369 int num;
370
371 num = ((struct syscall_metadata *)call->data)->syscall_nr;
372 if (WARN_ON_ONCE(num < 0 || num >= NR_syscalls))
373 return -ENOSYS;
374 mutex_lock(&syscall_trace_lock);
375 if (!sys_refcount_enter)
376 ret = register_trace_sys_enter(ftrace_syscall_enter, NULL);
377 if (!ret) {
378 set_bit(num, enabled_enter_syscalls);
379 sys_refcount_enter++;
380 }
381 mutex_unlock(&syscall_trace_lock);
382 return ret;
383}
384
385void unreg_event_syscall_enter(struct ftrace_event_call *call)
386{
387 int num;
388
389 num = ((struct syscall_metadata *)call->data)->syscall_nr;
390 if (WARN_ON_ONCE(num < 0 || num >= NR_syscalls))
391 return;
392 mutex_lock(&syscall_trace_lock);
393 sys_refcount_enter--;
394 clear_bit(num, enabled_enter_syscalls);
395 if (!sys_refcount_enter)
396 unregister_trace_sys_enter(ftrace_syscall_enter, NULL);
397 mutex_unlock(&syscall_trace_lock);
398}
399
400int reg_event_syscall_exit(struct ftrace_event_call *call)
401{
402 int ret = 0;
403 int num;
404
405 num = ((struct syscall_metadata *)call->data)->syscall_nr;
406 if (WARN_ON_ONCE(num < 0 || num >= NR_syscalls))
407 return -ENOSYS;
408 mutex_lock(&syscall_trace_lock);
409 if (!sys_refcount_exit)
410 ret = register_trace_sys_exit(ftrace_syscall_exit, NULL);
411 if (!ret) {
412 set_bit(num, enabled_exit_syscalls);
413 sys_refcount_exit++;
414 }
415 mutex_unlock(&syscall_trace_lock);
416 return ret;
417}
418
419void unreg_event_syscall_exit(struct ftrace_event_call *call)
420{
421 int num;
422
423 num = ((struct syscall_metadata *)call->data)->syscall_nr;
424 if (WARN_ON_ONCE(num < 0 || num >= NR_syscalls))
425 return;
426 mutex_lock(&syscall_trace_lock);
427 sys_refcount_exit--;
428 clear_bit(num, enabled_exit_syscalls);
429 if (!sys_refcount_exit)
430 unregister_trace_sys_exit(ftrace_syscall_exit, NULL);
431 mutex_unlock(&syscall_trace_lock);
432}
433
434int init_syscall_trace(struct ftrace_event_call *call)
435{
436 int id;
437 int num;
438
439 num = ((struct syscall_metadata *)call->data)->syscall_nr;
440 if (num < 0 || num >= NR_syscalls) {
441 pr_debug("syscall %s metadata not mapped, disabling ftrace event\n",
442 ((struct syscall_metadata *)call->data)->name);
443 return -ENOSYS;
444 }
445
446 if (set_syscall_print_fmt(call) < 0)
447 return -ENOMEM;
448
449 id = trace_event_raw_init(call);
450
451 if (id < 0) {
452 free_syscall_print_fmt(call);
453 return id;
454 }
455
456 return id;
457}
458
459unsigned long __init __weak arch_syscall_addr(int nr)
460{
461 return (unsigned long)sys_call_table[nr];
462}
463
464int __init init_ftrace_syscalls(void)
465{
466 struct syscall_metadata *meta;
467 unsigned long addr;
468 int i;
469
470 syscalls_metadata = kzalloc(sizeof(*syscalls_metadata) *
471 NR_syscalls, GFP_KERNEL);
472 if (!syscalls_metadata) {
473 WARN_ON(1);
474 return -ENOMEM;
475 }
476
477 for (i = 0; i < NR_syscalls; i++) {
478 addr = arch_syscall_addr(i);
479 meta = find_syscall_meta(addr);
480 if (!meta)
481 continue;
482
483 meta->syscall_nr = i;
484 syscalls_metadata[i] = meta;
485 }
486
487 return 0;
488}
489core_initcall(init_ftrace_syscalls);
490
491#ifdef CONFIG_PERF_EVENTS
492
493static DECLARE_BITMAP(enabled_perf_enter_syscalls, NR_syscalls);
494static DECLARE_BITMAP(enabled_perf_exit_syscalls, NR_syscalls);
495static int sys_perf_refcount_enter;
496static int sys_perf_refcount_exit;
497
498static void perf_syscall_enter(void *ignore, struct pt_regs *regs, long id)
499{
500 struct syscall_metadata *sys_data;
501 struct syscall_trace_enter *rec;
502 struct hlist_head *head;
503 int syscall_nr;
504 int rctx;
505 int size;
506
507 syscall_nr = syscall_get_nr(current, regs);
508 if (!test_bit(syscall_nr, enabled_perf_enter_syscalls))
509 return;
510
511 sys_data = syscall_nr_to_meta(syscall_nr);
512 if (!sys_data)
513 return;
514
515 /* get the size after alignment with the u32 buffer size field */
516 size = sizeof(unsigned long) * sys_data->nb_args + sizeof(*rec);
517 size = ALIGN(size + sizeof(u32), sizeof(u64));
518 size -= sizeof(u32);
519
520 if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE,
521 "perf buffer not large enough"))
522 return;
523
524 rec = (struct syscall_trace_enter *)perf_trace_buf_prepare(size,
525 sys_data->enter_event->event.type, regs, &rctx);
526 if (!rec)
527 return;
528
529 rec->nr = syscall_nr;
530 syscall_get_arguments(current, regs, 0, sys_data->nb_args,
531 (unsigned long *)&rec->args);
532
533 head = this_cpu_ptr(sys_data->enter_event->perf_events);
534 perf_trace_buf_submit(rec, size, rctx, 0, 1, regs, head);
535}
536
537int perf_sysenter_enable(struct ftrace_event_call *call)
538{
539 int ret = 0;
540 int num;
541
542 num = ((struct syscall_metadata *)call->data)->syscall_nr;
543
544 mutex_lock(&syscall_trace_lock);
545 if (!sys_perf_refcount_enter)
546 ret = register_trace_sys_enter(perf_syscall_enter, NULL);
547 if (ret) {
548 pr_info("event trace: Could not activate"
549 "syscall entry trace point");
550 } else {
551 set_bit(num, enabled_perf_enter_syscalls);
552 sys_perf_refcount_enter++;
553 }
554 mutex_unlock(&syscall_trace_lock);
555 return ret;
556}
557
558void perf_sysenter_disable(struct ftrace_event_call *call)
559{
560 int num;
561
562 num = ((struct syscall_metadata *)call->data)->syscall_nr;
563
564 mutex_lock(&syscall_trace_lock);
565 sys_perf_refcount_enter--;
566 clear_bit(num, enabled_perf_enter_syscalls);
567 if (!sys_perf_refcount_enter)
568 unregister_trace_sys_enter(perf_syscall_enter, NULL);
569 mutex_unlock(&syscall_trace_lock);
570}
571
572static void perf_syscall_exit(void *ignore, struct pt_regs *regs, long ret)
573{
574 struct syscall_metadata *sys_data;
575 struct syscall_trace_exit *rec;
576 struct hlist_head *head;
577 int syscall_nr;
578 int rctx;
579 int size;
580
581 syscall_nr = syscall_get_nr(current, regs);
582 if (!test_bit(syscall_nr, enabled_perf_exit_syscalls))
583 return;
584
585 sys_data = syscall_nr_to_meta(syscall_nr);
586 if (!sys_data)
587 return;
588
589 /* We can probably do that at build time */
590 size = ALIGN(sizeof(*rec) + sizeof(u32), sizeof(u64));
591 size -= sizeof(u32);
592
593 /*
594 * Impossible, but be paranoid with the future
595 * How to put this check outside runtime?
596 */
597 if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE,
598 "exit event has grown above perf buffer size"))
599 return;
600
601 rec = (struct syscall_trace_exit *)perf_trace_buf_prepare(size,
602 sys_data->exit_event->event.type, regs, &rctx);
603 if (!rec)
604 return;
605
606 rec->nr = syscall_nr;
607 rec->ret = syscall_get_return_value(current, regs);
608
609 head = this_cpu_ptr(sys_data->exit_event->perf_events);
610 perf_trace_buf_submit(rec, size, rctx, 0, 1, regs, head);
611}
612
613int perf_sysexit_enable(struct ftrace_event_call *call)
614{
615 int ret = 0;
616 int num;
617
618 num = ((struct syscall_metadata *)call->data)->syscall_nr;
619
620 mutex_lock(&syscall_trace_lock);
621 if (!sys_perf_refcount_exit)
622 ret = register_trace_sys_exit(perf_syscall_exit, NULL);
623 if (ret) {
624 pr_info("event trace: Could not activate"
625 "syscall exit trace point");
626 } else {
627 set_bit(num, enabled_perf_exit_syscalls);
628 sys_perf_refcount_exit++;
629 }
630 mutex_unlock(&syscall_trace_lock);
631 return ret;
632}
633
634void perf_sysexit_disable(struct ftrace_event_call *call)
635{
636 int num;
637
638 num = ((struct syscall_metadata *)call->data)->syscall_nr;
639
640 mutex_lock(&syscall_trace_lock);
641 sys_perf_refcount_exit--;
642 clear_bit(num, enabled_perf_exit_syscalls);
643 if (!sys_perf_refcount_exit)
644 unregister_trace_sys_exit(perf_syscall_exit, NULL);
645 mutex_unlock(&syscall_trace_lock);
646}
647
648#endif /* CONFIG_PERF_EVENTS */
649
650static int syscall_enter_register(struct ftrace_event_call *event,
651 enum trace_reg type)
652{
653 switch (type) {
654 case TRACE_REG_REGISTER:
655 return reg_event_syscall_enter(event);
656 case TRACE_REG_UNREGISTER:
657 unreg_event_syscall_enter(event);
658 return 0;
659
660#ifdef CONFIG_PERF_EVENTS
661 case TRACE_REG_PERF_REGISTER:
662 return perf_sysenter_enable(event);
663 case TRACE_REG_PERF_UNREGISTER:
664 perf_sysenter_disable(event);
665 return 0;
666#endif
667 }
668 return 0;
669}
670
671static int syscall_exit_register(struct ftrace_event_call *event,
672 enum trace_reg type)
673{
674 switch (type) {
675 case TRACE_REG_REGISTER:
676 return reg_event_syscall_exit(event);
677 case TRACE_REG_UNREGISTER:
678 unreg_event_syscall_exit(event);
679 return 0;
680
681#ifdef CONFIG_PERF_EVENTS
682 case TRACE_REG_PERF_REGISTER:
683 return perf_sysexit_enable(event);
684 case TRACE_REG_PERF_UNREGISTER:
685 perf_sysexit_disable(event);
686 return 0;
687#endif
688 }
689 return 0;
690}