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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 <linux/xarray.h>
11#include <asm/syscall.h>
12
13#include "trace_output.h"
14#include "trace.h"
15
16static DEFINE_MUTEX(syscall_trace_lock);
17
18static int syscall_enter_register(struct trace_event_call *event,
19 enum trace_reg type, void *data);
20static int syscall_exit_register(struct trace_event_call *event,
21 enum trace_reg type, void *data);
22
23static struct list_head *
24syscall_get_enter_fields(struct trace_event_call *call)
25{
26 struct syscall_metadata *entry = call->data;
27
28 return &entry->enter_fields;
29}
30
31extern struct syscall_metadata *__start_syscalls_metadata[];
32extern struct syscall_metadata *__stop_syscalls_metadata[];
33
34static DEFINE_XARRAY(syscalls_metadata_sparse);
35static struct syscall_metadata **syscalls_metadata;
36
37#ifndef ARCH_HAS_SYSCALL_MATCH_SYM_NAME
38static inline bool arch_syscall_match_sym_name(const char *sym, const char *name)
39{
40 /*
41 * Only compare after the "sys" prefix. Archs that use
42 * syscall wrappers may have syscalls symbols aliases prefixed
43 * with ".SyS" or ".sys" instead of "sys", leading to an unwanted
44 * mismatch.
45 */
46 return !strcmp(sym + 3, name + 3);
47}
48#endif
49
50#ifdef ARCH_TRACE_IGNORE_COMPAT_SYSCALLS
51/*
52 * Some architectures that allow for 32bit applications
53 * to run on a 64bit kernel, do not map the syscalls for
54 * the 32bit tasks the same as they do for 64bit tasks.
55 *
56 * *cough*x86*cough*
57 *
58 * In such a case, instead of reporting the wrong syscalls,
59 * simply ignore them.
60 *
61 * For an arch to ignore the compat syscalls it needs to
62 * define ARCH_TRACE_IGNORE_COMPAT_SYSCALLS as well as
63 * define the function arch_trace_is_compat_syscall() to let
64 * the tracing system know that it should ignore it.
65 */
66static int
67trace_get_syscall_nr(struct task_struct *task, struct pt_regs *regs)
68{
69 if (unlikely(arch_trace_is_compat_syscall(regs)))
70 return -1;
71
72 return syscall_get_nr(task, regs);
73}
74#else
75static inline int
76trace_get_syscall_nr(struct task_struct *task, struct pt_regs *regs)
77{
78 return syscall_get_nr(task, regs);
79}
80#endif /* ARCH_TRACE_IGNORE_COMPAT_SYSCALLS */
81
82static __init struct syscall_metadata *
83find_syscall_meta(unsigned long syscall)
84{
85 struct syscall_metadata **start;
86 struct syscall_metadata **stop;
87 char str[KSYM_SYMBOL_LEN];
88
89
90 start = __start_syscalls_metadata;
91 stop = __stop_syscalls_metadata;
92 kallsyms_lookup(syscall, NULL, NULL, NULL, str);
93
94 if (arch_syscall_match_sym_name(str, "sys_ni_syscall"))
95 return NULL;
96
97 for ( ; start < stop; start++) {
98 if ((*start)->name && arch_syscall_match_sym_name(str, (*start)->name))
99 return *start;
100 }
101 return NULL;
102}
103
104static struct syscall_metadata *syscall_nr_to_meta(int nr)
105{
106 if (IS_ENABLED(CONFIG_HAVE_SPARSE_SYSCALL_NR))
107 return xa_load(&syscalls_metadata_sparse, (unsigned long)nr);
108
109 if (!syscalls_metadata || nr >= NR_syscalls || nr < 0)
110 return NULL;
111
112 return syscalls_metadata[nr];
113}
114
115const char *get_syscall_name(int syscall)
116{
117 struct syscall_metadata *entry;
118
119 entry = syscall_nr_to_meta(syscall);
120 if (!entry)
121 return NULL;
122
123 return entry->name;
124}
125
126static enum print_line_t
127print_syscall_enter(struct trace_iterator *iter, int flags,
128 struct trace_event *event)
129{
130 struct trace_array *tr = iter->tr;
131 struct trace_seq *s = &iter->seq;
132 struct trace_entry *ent = iter->ent;
133 struct syscall_trace_enter *trace;
134 struct syscall_metadata *entry;
135 int i, syscall;
136
137 trace = (typeof(trace))ent;
138 syscall = trace->nr;
139 entry = syscall_nr_to_meta(syscall);
140
141 if (!entry)
142 goto end;
143
144 if (entry->enter_event->event.type != ent->type) {
145 WARN_ON_ONCE(1);
146 goto end;
147 }
148
149 trace_seq_printf(s, "%s(", entry->name);
150
151 for (i = 0; i < entry->nb_args; i++) {
152
153 if (trace_seq_has_overflowed(s))
154 goto end;
155
156 /* parameter types */
157 if (tr->trace_flags & TRACE_ITER_VERBOSE)
158 trace_seq_printf(s, "%s ", entry->types[i]);
159
160 /* parameter values */
161 trace_seq_printf(s, "%s: %lx%s", entry->args[i],
162 trace->args[i],
163 i == entry->nb_args - 1 ? "" : ", ");
164 }
165
166 trace_seq_putc(s, ')');
167end:
168 trace_seq_putc(s, '\n');
169
170 return trace_handle_return(s);
171}
172
173static enum print_line_t
174print_syscall_exit(struct trace_iterator *iter, int flags,
175 struct trace_event *event)
176{
177 struct trace_seq *s = &iter->seq;
178 struct trace_entry *ent = iter->ent;
179 struct syscall_trace_exit *trace;
180 int syscall;
181 struct syscall_metadata *entry;
182
183 trace = (typeof(trace))ent;
184 syscall = trace->nr;
185 entry = syscall_nr_to_meta(syscall);
186
187 if (!entry) {
188 trace_seq_putc(s, '\n');
189 goto out;
190 }
191
192 if (entry->exit_event->event.type != ent->type) {
193 WARN_ON_ONCE(1);
194 return TRACE_TYPE_UNHANDLED;
195 }
196
197 trace_seq_printf(s, "%s -> 0x%lx\n", entry->name,
198 trace->ret);
199
200 out:
201 return trace_handle_return(s);
202}
203
204extern char *__bad_type_size(void);
205
206#define SYSCALL_FIELD(_type, _name) { \
207 .type = #_type, .name = #_name, \
208 .size = sizeof(_type), .align = __alignof__(_type), \
209 .is_signed = is_signed_type(_type), .filter_type = FILTER_OTHER }
210
211static int __init
212__set_enter_print_fmt(struct syscall_metadata *entry, char *buf, int len)
213{
214 int i;
215 int pos = 0;
216
217 /* When len=0, we just calculate the needed length */
218#define LEN_OR_ZERO (len ? len - pos : 0)
219
220 pos += snprintf(buf + pos, LEN_OR_ZERO, "\"");
221 for (i = 0; i < entry->nb_args; i++) {
222 pos += snprintf(buf + pos, LEN_OR_ZERO, "%s: 0x%%0%zulx%s",
223 entry->args[i], sizeof(unsigned long),
224 i == entry->nb_args - 1 ? "" : ", ");
225 }
226 pos += snprintf(buf + pos, LEN_OR_ZERO, "\"");
227
228 for (i = 0; i < entry->nb_args; i++) {
229 pos += snprintf(buf + pos, LEN_OR_ZERO,
230 ", ((unsigned long)(REC->%s))", entry->args[i]);
231 }
232
233#undef LEN_OR_ZERO
234
235 /* return the length of print_fmt */
236 return pos;
237}
238
239static int __init set_syscall_print_fmt(struct trace_event_call *call)
240{
241 char *print_fmt;
242 int len;
243 struct syscall_metadata *entry = call->data;
244
245 if (entry->enter_event != call) {
246 call->print_fmt = "\"0x%lx\", REC->ret";
247 return 0;
248 }
249
250 /* First: called with 0 length to calculate the needed length */
251 len = __set_enter_print_fmt(entry, NULL, 0);
252
253 print_fmt = kmalloc(len + 1, GFP_KERNEL);
254 if (!print_fmt)
255 return -ENOMEM;
256
257 /* Second: actually write the @print_fmt */
258 __set_enter_print_fmt(entry, print_fmt, len + 1);
259 call->print_fmt = print_fmt;
260
261 return 0;
262}
263
264static void __init free_syscall_print_fmt(struct trace_event_call *call)
265{
266 struct syscall_metadata *entry = call->data;
267
268 if (entry->enter_event == call)
269 kfree(call->print_fmt);
270}
271
272static int __init syscall_enter_define_fields(struct trace_event_call *call)
273{
274 struct syscall_trace_enter trace;
275 struct syscall_metadata *meta = call->data;
276 int offset = offsetof(typeof(trace), args);
277 int ret = 0;
278 int i;
279
280 for (i = 0; i < meta->nb_args; i++) {
281 ret = trace_define_field(call, meta->types[i],
282 meta->args[i], offset,
283 sizeof(unsigned long), 0,
284 FILTER_OTHER);
285 if (ret)
286 break;
287 offset += sizeof(unsigned long);
288 }
289
290 return ret;
291}
292
293static void ftrace_syscall_enter(void *data, struct pt_regs *regs, long id)
294{
295 struct trace_array *tr = data;
296 struct trace_event_file *trace_file;
297 struct syscall_trace_enter *entry;
298 struct syscall_metadata *sys_data;
299 struct ring_buffer_event *event;
300 struct trace_buffer *buffer;
301 unsigned int trace_ctx;
302 unsigned long args[6];
303 int syscall_nr;
304 int size;
305
306 syscall_nr = trace_get_syscall_nr(current, regs);
307 if (syscall_nr < 0 || syscall_nr >= NR_syscalls)
308 return;
309
310 /* Here we're inside tp handler's rcu_read_lock_sched (__DO_TRACE) */
311 trace_file = rcu_dereference_sched(tr->enter_syscall_files[syscall_nr]);
312 if (!trace_file)
313 return;
314
315 if (trace_trigger_soft_disabled(trace_file))
316 return;
317
318 sys_data = syscall_nr_to_meta(syscall_nr);
319 if (!sys_data)
320 return;
321
322 size = sizeof(*entry) + sizeof(unsigned long) * sys_data->nb_args;
323
324 trace_ctx = tracing_gen_ctx();
325
326 buffer = tr->array_buffer.buffer;
327 event = trace_buffer_lock_reserve(buffer,
328 sys_data->enter_event->event.type, size, trace_ctx);
329 if (!event)
330 return;
331
332 entry = ring_buffer_event_data(event);
333 entry->nr = syscall_nr;
334 syscall_get_arguments(current, regs, args);
335 memcpy(entry->args, args, sizeof(unsigned long) * sys_data->nb_args);
336
337 event_trigger_unlock_commit(trace_file, buffer, event, entry,
338 trace_ctx);
339}
340
341static void ftrace_syscall_exit(void *data, struct pt_regs *regs, long ret)
342{
343 struct trace_array *tr = data;
344 struct trace_event_file *trace_file;
345 struct syscall_trace_exit *entry;
346 struct syscall_metadata *sys_data;
347 struct ring_buffer_event *event;
348 struct trace_buffer *buffer;
349 unsigned int trace_ctx;
350 int syscall_nr;
351
352 syscall_nr = trace_get_syscall_nr(current, regs);
353 if (syscall_nr < 0 || syscall_nr >= NR_syscalls)
354 return;
355
356 /* Here we're inside tp handler's rcu_read_lock_sched (__DO_TRACE()) */
357 trace_file = rcu_dereference_sched(tr->exit_syscall_files[syscall_nr]);
358 if (!trace_file)
359 return;
360
361 if (trace_trigger_soft_disabled(trace_file))
362 return;
363
364 sys_data = syscall_nr_to_meta(syscall_nr);
365 if (!sys_data)
366 return;
367
368 trace_ctx = tracing_gen_ctx();
369
370 buffer = tr->array_buffer.buffer;
371 event = trace_buffer_lock_reserve(buffer,
372 sys_data->exit_event->event.type, sizeof(*entry),
373 trace_ctx);
374 if (!event)
375 return;
376
377 entry = ring_buffer_event_data(event);
378 entry->nr = syscall_nr;
379 entry->ret = syscall_get_return_value(current, regs);
380
381 event_trigger_unlock_commit(trace_file, buffer, event, entry,
382 trace_ctx);
383}
384
385static int reg_event_syscall_enter(struct trace_event_file *file,
386 struct trace_event_call *call)
387{
388 struct trace_array *tr = file->tr;
389 int ret = 0;
390 int num;
391
392 num = ((struct syscall_metadata *)call->data)->syscall_nr;
393 if (WARN_ON_ONCE(num < 0 || num >= NR_syscalls))
394 return -ENOSYS;
395 mutex_lock(&syscall_trace_lock);
396 if (!tr->sys_refcount_enter)
397 ret = register_trace_sys_enter(ftrace_syscall_enter, tr);
398 if (!ret) {
399 rcu_assign_pointer(tr->enter_syscall_files[num], file);
400 tr->sys_refcount_enter++;
401 }
402 mutex_unlock(&syscall_trace_lock);
403 return ret;
404}
405
406static void unreg_event_syscall_enter(struct trace_event_file *file,
407 struct trace_event_call *call)
408{
409 struct trace_array *tr = file->tr;
410 int num;
411
412 num = ((struct syscall_metadata *)call->data)->syscall_nr;
413 if (WARN_ON_ONCE(num < 0 || num >= NR_syscalls))
414 return;
415 mutex_lock(&syscall_trace_lock);
416 tr->sys_refcount_enter--;
417 RCU_INIT_POINTER(tr->enter_syscall_files[num], NULL);
418 if (!tr->sys_refcount_enter)
419 unregister_trace_sys_enter(ftrace_syscall_enter, tr);
420 mutex_unlock(&syscall_trace_lock);
421}
422
423static int reg_event_syscall_exit(struct trace_event_file *file,
424 struct trace_event_call *call)
425{
426 struct trace_array *tr = file->tr;
427 int ret = 0;
428 int num;
429
430 num = ((struct syscall_metadata *)call->data)->syscall_nr;
431 if (WARN_ON_ONCE(num < 0 || num >= NR_syscalls))
432 return -ENOSYS;
433 mutex_lock(&syscall_trace_lock);
434 if (!tr->sys_refcount_exit)
435 ret = register_trace_sys_exit(ftrace_syscall_exit, tr);
436 if (!ret) {
437 rcu_assign_pointer(tr->exit_syscall_files[num], file);
438 tr->sys_refcount_exit++;
439 }
440 mutex_unlock(&syscall_trace_lock);
441 return ret;
442}
443
444static void unreg_event_syscall_exit(struct trace_event_file *file,
445 struct trace_event_call *call)
446{
447 struct trace_array *tr = file->tr;
448 int num;
449
450 num = ((struct syscall_metadata *)call->data)->syscall_nr;
451 if (WARN_ON_ONCE(num < 0 || num >= NR_syscalls))
452 return;
453 mutex_lock(&syscall_trace_lock);
454 tr->sys_refcount_exit--;
455 RCU_INIT_POINTER(tr->exit_syscall_files[num], NULL);
456 if (!tr->sys_refcount_exit)
457 unregister_trace_sys_exit(ftrace_syscall_exit, tr);
458 mutex_unlock(&syscall_trace_lock);
459}
460
461static int __init init_syscall_trace(struct trace_event_call *call)
462{
463 int id;
464 int num;
465
466 num = ((struct syscall_metadata *)call->data)->syscall_nr;
467 if (num < 0 || num >= NR_syscalls) {
468 pr_debug("syscall %s metadata not mapped, disabling ftrace event\n",
469 ((struct syscall_metadata *)call->data)->name);
470 return -ENOSYS;
471 }
472
473 if (set_syscall_print_fmt(call) < 0)
474 return -ENOMEM;
475
476 id = trace_event_raw_init(call);
477
478 if (id < 0) {
479 free_syscall_print_fmt(call);
480 return id;
481 }
482
483 return id;
484}
485
486static struct trace_event_fields __refdata syscall_enter_fields_array[] = {
487 SYSCALL_FIELD(int, __syscall_nr),
488 { .type = TRACE_FUNCTION_TYPE,
489 .define_fields = syscall_enter_define_fields },
490 {}
491};
492
493struct trace_event_functions enter_syscall_print_funcs = {
494 .trace = print_syscall_enter,
495};
496
497struct trace_event_functions exit_syscall_print_funcs = {
498 .trace = print_syscall_exit,
499};
500
501struct trace_event_class __refdata event_class_syscall_enter = {
502 .system = "syscalls",
503 .reg = syscall_enter_register,
504 .fields_array = syscall_enter_fields_array,
505 .get_fields = syscall_get_enter_fields,
506 .raw_init = init_syscall_trace,
507};
508
509struct trace_event_class __refdata event_class_syscall_exit = {
510 .system = "syscalls",
511 .reg = syscall_exit_register,
512 .fields_array = (struct trace_event_fields[]){
513 SYSCALL_FIELD(int, __syscall_nr),
514 SYSCALL_FIELD(long, ret),
515 {}
516 },
517 .fields = LIST_HEAD_INIT(event_class_syscall_exit.fields),
518 .raw_init = init_syscall_trace,
519};
520
521unsigned long __init __weak arch_syscall_addr(int nr)
522{
523 return (unsigned long)sys_call_table[nr];
524}
525
526void __init init_ftrace_syscalls(void)
527{
528 struct syscall_metadata *meta;
529 unsigned long addr;
530 int i;
531 void *ret;
532
533 if (!IS_ENABLED(CONFIG_HAVE_SPARSE_SYSCALL_NR)) {
534 syscalls_metadata = kcalloc(NR_syscalls,
535 sizeof(*syscalls_metadata),
536 GFP_KERNEL);
537 if (!syscalls_metadata) {
538 WARN_ON(1);
539 return;
540 }
541 }
542
543 for (i = 0; i < NR_syscalls; i++) {
544 addr = arch_syscall_addr(i);
545 meta = find_syscall_meta(addr);
546 if (!meta)
547 continue;
548
549 meta->syscall_nr = i;
550
551 if (!IS_ENABLED(CONFIG_HAVE_SPARSE_SYSCALL_NR)) {
552 syscalls_metadata[i] = meta;
553 } else {
554 ret = xa_store(&syscalls_metadata_sparse, i, meta,
555 GFP_KERNEL);
556 WARN(xa_is_err(ret),
557 "Syscall memory allocation failed\n");
558 }
559
560 }
561}
562
563#ifdef CONFIG_PERF_EVENTS
564
565static DECLARE_BITMAP(enabled_perf_enter_syscalls, NR_syscalls);
566static DECLARE_BITMAP(enabled_perf_exit_syscalls, NR_syscalls);
567static int sys_perf_refcount_enter;
568static int sys_perf_refcount_exit;
569
570static int perf_call_bpf_enter(struct trace_event_call *call, struct pt_regs *regs,
571 struct syscall_metadata *sys_data,
572 struct syscall_trace_enter *rec)
573{
574 struct syscall_tp_t {
575 unsigned long long regs;
576 unsigned long syscall_nr;
577 unsigned long args[SYSCALL_DEFINE_MAXARGS];
578 } param;
579 int i;
580
581 *(struct pt_regs **)¶m = regs;
582 param.syscall_nr = rec->nr;
583 for (i = 0; i < sys_data->nb_args; i++)
584 param.args[i] = rec->args[i];
585 return trace_call_bpf(call, ¶m);
586}
587
588static void perf_syscall_enter(void *ignore, struct pt_regs *regs, long id)
589{
590 struct syscall_metadata *sys_data;
591 struct syscall_trace_enter *rec;
592 struct hlist_head *head;
593 unsigned long args[6];
594 bool valid_prog_array;
595 int syscall_nr;
596 int rctx;
597 int size;
598
599 syscall_nr = trace_get_syscall_nr(current, regs);
600 if (syscall_nr < 0 || syscall_nr >= NR_syscalls)
601 return;
602 if (!test_bit(syscall_nr, enabled_perf_enter_syscalls))
603 return;
604
605 sys_data = syscall_nr_to_meta(syscall_nr);
606 if (!sys_data)
607 return;
608
609 head = this_cpu_ptr(sys_data->enter_event->perf_events);
610 valid_prog_array = bpf_prog_array_valid(sys_data->enter_event);
611 if (!valid_prog_array && hlist_empty(head))
612 return;
613
614 /* get the size after alignment with the u32 buffer size field */
615 size = sizeof(unsigned long) * sys_data->nb_args + sizeof(*rec);
616 size = ALIGN(size + sizeof(u32), sizeof(u64));
617 size -= sizeof(u32);
618
619 rec = perf_trace_buf_alloc(size, NULL, &rctx);
620 if (!rec)
621 return;
622
623 rec->nr = syscall_nr;
624 syscall_get_arguments(current, regs, args);
625 memcpy(&rec->args, args, sizeof(unsigned long) * sys_data->nb_args);
626
627 if ((valid_prog_array &&
628 !perf_call_bpf_enter(sys_data->enter_event, regs, sys_data, rec)) ||
629 hlist_empty(head)) {
630 perf_swevent_put_recursion_context(rctx);
631 return;
632 }
633
634 perf_trace_buf_submit(rec, size, rctx,
635 sys_data->enter_event->event.type, 1, regs,
636 head, NULL);
637}
638
639static int perf_sysenter_enable(struct trace_event_call *call)
640{
641 int ret = 0;
642 int num;
643
644 num = ((struct syscall_metadata *)call->data)->syscall_nr;
645
646 mutex_lock(&syscall_trace_lock);
647 if (!sys_perf_refcount_enter)
648 ret = register_trace_sys_enter(perf_syscall_enter, NULL);
649 if (ret) {
650 pr_info("event trace: Could not activate syscall entry trace point");
651 } else {
652 set_bit(num, enabled_perf_enter_syscalls);
653 sys_perf_refcount_enter++;
654 }
655 mutex_unlock(&syscall_trace_lock);
656 return ret;
657}
658
659static void perf_sysenter_disable(struct trace_event_call *call)
660{
661 int num;
662
663 num = ((struct syscall_metadata *)call->data)->syscall_nr;
664
665 mutex_lock(&syscall_trace_lock);
666 sys_perf_refcount_enter--;
667 clear_bit(num, enabled_perf_enter_syscalls);
668 if (!sys_perf_refcount_enter)
669 unregister_trace_sys_enter(perf_syscall_enter, NULL);
670 mutex_unlock(&syscall_trace_lock);
671}
672
673static int perf_call_bpf_exit(struct trace_event_call *call, struct pt_regs *regs,
674 struct syscall_trace_exit *rec)
675{
676 struct syscall_tp_t {
677 unsigned long long regs;
678 unsigned long syscall_nr;
679 unsigned long ret;
680 } param;
681
682 *(struct pt_regs **)¶m = regs;
683 param.syscall_nr = rec->nr;
684 param.ret = rec->ret;
685 return trace_call_bpf(call, ¶m);
686}
687
688static void perf_syscall_exit(void *ignore, struct pt_regs *regs, long ret)
689{
690 struct syscall_metadata *sys_data;
691 struct syscall_trace_exit *rec;
692 struct hlist_head *head;
693 bool valid_prog_array;
694 int syscall_nr;
695 int rctx;
696 int size;
697
698 syscall_nr = trace_get_syscall_nr(current, regs);
699 if (syscall_nr < 0 || syscall_nr >= NR_syscalls)
700 return;
701 if (!test_bit(syscall_nr, enabled_perf_exit_syscalls))
702 return;
703
704 sys_data = syscall_nr_to_meta(syscall_nr);
705 if (!sys_data)
706 return;
707
708 head = this_cpu_ptr(sys_data->exit_event->perf_events);
709 valid_prog_array = bpf_prog_array_valid(sys_data->exit_event);
710 if (!valid_prog_array && hlist_empty(head))
711 return;
712
713 /* We can probably do that at build time */
714 size = ALIGN(sizeof(*rec) + sizeof(u32), sizeof(u64));
715 size -= sizeof(u32);
716
717 rec = perf_trace_buf_alloc(size, NULL, &rctx);
718 if (!rec)
719 return;
720
721 rec->nr = syscall_nr;
722 rec->ret = syscall_get_return_value(current, regs);
723
724 if ((valid_prog_array &&
725 !perf_call_bpf_exit(sys_data->exit_event, regs, rec)) ||
726 hlist_empty(head)) {
727 perf_swevent_put_recursion_context(rctx);
728 return;
729 }
730
731 perf_trace_buf_submit(rec, size, rctx, sys_data->exit_event->event.type,
732 1, regs, head, NULL);
733}
734
735static int perf_sysexit_enable(struct trace_event_call *call)
736{
737 int ret = 0;
738 int num;
739
740 num = ((struct syscall_metadata *)call->data)->syscall_nr;
741
742 mutex_lock(&syscall_trace_lock);
743 if (!sys_perf_refcount_exit)
744 ret = register_trace_sys_exit(perf_syscall_exit, NULL);
745 if (ret) {
746 pr_info("event trace: Could not activate syscall exit trace point");
747 } else {
748 set_bit(num, enabled_perf_exit_syscalls);
749 sys_perf_refcount_exit++;
750 }
751 mutex_unlock(&syscall_trace_lock);
752 return ret;
753}
754
755static void perf_sysexit_disable(struct trace_event_call *call)
756{
757 int num;
758
759 num = ((struct syscall_metadata *)call->data)->syscall_nr;
760
761 mutex_lock(&syscall_trace_lock);
762 sys_perf_refcount_exit--;
763 clear_bit(num, enabled_perf_exit_syscalls);
764 if (!sys_perf_refcount_exit)
765 unregister_trace_sys_exit(perf_syscall_exit, NULL);
766 mutex_unlock(&syscall_trace_lock);
767}
768
769#endif /* CONFIG_PERF_EVENTS */
770
771static int syscall_enter_register(struct trace_event_call *event,
772 enum trace_reg type, void *data)
773{
774 struct trace_event_file *file = data;
775
776 switch (type) {
777 case TRACE_REG_REGISTER:
778 return reg_event_syscall_enter(file, event);
779 case TRACE_REG_UNREGISTER:
780 unreg_event_syscall_enter(file, event);
781 return 0;
782
783#ifdef CONFIG_PERF_EVENTS
784 case TRACE_REG_PERF_REGISTER:
785 return perf_sysenter_enable(event);
786 case TRACE_REG_PERF_UNREGISTER:
787 perf_sysenter_disable(event);
788 return 0;
789 case TRACE_REG_PERF_OPEN:
790 case TRACE_REG_PERF_CLOSE:
791 case TRACE_REG_PERF_ADD:
792 case TRACE_REG_PERF_DEL:
793 return 0;
794#endif
795 }
796 return 0;
797}
798
799static int syscall_exit_register(struct trace_event_call *event,
800 enum trace_reg type, void *data)
801{
802 struct trace_event_file *file = data;
803
804 switch (type) {
805 case TRACE_REG_REGISTER:
806 return reg_event_syscall_exit(file, event);
807 case TRACE_REG_UNREGISTER:
808 unreg_event_syscall_exit(file, event);
809 return 0;
810
811#ifdef CONFIG_PERF_EVENTS
812 case TRACE_REG_PERF_REGISTER:
813 return perf_sysexit_enable(event);
814 case TRACE_REG_PERF_UNREGISTER:
815 perf_sysexit_disable(event);
816 return 0;
817 case TRACE_REG_PERF_OPEN:
818 case TRACE_REG_PERF_CLOSE:
819 case TRACE_REG_PERF_ADD:
820 case TRACE_REG_PERF_DEL:
821 return 0;
822#endif
823 }
824 return 0;
825}
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}