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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 | ||
12 | static DEFINE_MUTEX(syscall_trace_lock); | |
13 | static int sys_refcount_enter; | |
14 | static int sys_refcount_exit; | |
15 | static DECLARE_BITMAP(enabled_enter_syscalls, NR_syscalls); | |
16 | static DECLARE_BITMAP(enabled_exit_syscalls, NR_syscalls); | |
17 | ||
18 | static int syscall_enter_register(struct ftrace_event_call *event, | |
19 | enum trace_reg type); | |
20 | static int syscall_exit_register(struct ftrace_event_call *event, | |
21 | enum trace_reg type); | |
22 | ||
23 | static int syscall_enter_define_fields(struct ftrace_event_call *call); | |
24 | static int syscall_exit_define_fields(struct ftrace_event_call *call); | |
25 | ||
26 | /* All syscall exit events have the same fields */ | |
27 | static LIST_HEAD(syscall_exit_fields); | |
28 | ||
29 | static struct list_head * | |
30 | syscall_get_enter_fields(struct ftrace_event_call *call) | |
31 | { | |
32 | struct syscall_metadata *entry = call->data; | |
33 | ||
34 | return &entry->enter_fields; | |
35 | } | |
36 | ||
37 | static struct list_head * | |
38 | syscall_get_exit_fields(struct ftrace_event_call *call) | |
39 | { | |
40 | return &syscall_exit_fields; | |
41 | } | |
42 | ||
43 | struct trace_event_functions enter_syscall_print_funcs = { | |
44 | .trace = print_syscall_enter, | |
45 | }; | |
46 | ||
47 | struct trace_event_functions exit_syscall_print_funcs = { | |
48 | .trace = print_syscall_exit, | |
49 | }; | |
50 | ||
51 | struct ftrace_event_class event_class_syscall_enter = { | |
52 | .system = "syscalls", | |
53 | .reg = syscall_enter_register, | |
54 | .define_fields = syscall_enter_define_fields, | |
55 | .get_fields = syscall_get_enter_fields, | |
56 | .raw_init = init_syscall_trace, | |
57 | }; | |
58 | ||
59 | struct ftrace_event_class event_class_syscall_exit = { | |
60 | .system = "syscalls", | |
61 | .reg = syscall_exit_register, | |
62 | .define_fields = syscall_exit_define_fields, | |
63 | .get_fields = syscall_get_exit_fields, | |
64 | .raw_init = init_syscall_trace, | |
65 | }; | |
66 | ||
67 | extern unsigned long __start_syscalls_metadata[]; | |
68 | extern unsigned long __stop_syscalls_metadata[]; | |
69 | ||
70 | static struct syscall_metadata **syscalls_metadata; | |
71 | ||
72 | static struct syscall_metadata *find_syscall_meta(unsigned long syscall) | |
73 | { | |
74 | struct syscall_metadata *start; | |
75 | struct syscall_metadata *stop; | |
76 | char str[KSYM_SYMBOL_LEN]; | |
77 | ||
78 | ||
79 | start = (struct syscall_metadata *)__start_syscalls_metadata; | |
80 | stop = (struct syscall_metadata *)__stop_syscalls_metadata; | |
81 | kallsyms_lookup(syscall, NULL, NULL, NULL, str); | |
82 | ||
83 | for ( ; start < stop; start++) { | |
84 | /* | |
85 | * Only compare after the "sys" prefix. Archs that use | |
86 | * syscall wrappers may have syscalls symbols aliases prefixed | |
87 | * with "SyS" instead of "sys", leading to an unwanted | |
88 | * mismatch. | |
89 | */ | |
90 | if (start->name && !strcmp(start->name + 3, str + 3)) | |
91 | return start; | |
92 | } | |
93 | return NULL; | |
94 | } | |
95 | ||
96 | static struct syscall_metadata *syscall_nr_to_meta(int nr) | |
97 | { | |
98 | if (!syscalls_metadata || nr >= NR_syscalls || nr < 0) | |
99 | return NULL; | |
100 | ||
101 | return syscalls_metadata[nr]; | |
102 | } | |
103 | ||
104 | enum print_line_t | |
105 | print_syscall_enter(struct trace_iterator *iter, int flags, | |
106 | struct trace_event *event) | |
107 | { | |
108 | struct trace_seq *s = &iter->seq; | |
109 | struct trace_entry *ent = iter->ent; | |
110 | struct syscall_trace_enter *trace; | |
111 | struct syscall_metadata *entry; | |
112 | int i, ret, syscall; | |
113 | ||
114 | trace = (typeof(trace))ent; | |
115 | syscall = trace->nr; | |
116 | entry = syscall_nr_to_meta(syscall); | |
117 | ||
118 | if (!entry) | |
119 | goto end; | |
120 | ||
121 | if (entry->enter_event->event.type != ent->type) { | |
122 | WARN_ON_ONCE(1); | |
123 | goto end; | |
124 | } | |
125 | ||
126 | ret = trace_seq_printf(s, "%s(", entry->name); | |
127 | if (!ret) | |
128 | return TRACE_TYPE_PARTIAL_LINE; | |
129 | ||
130 | for (i = 0; i < entry->nb_args; i++) { | |
131 | /* parameter types */ | |
132 | if (trace_flags & TRACE_ITER_VERBOSE) { | |
133 | ret = trace_seq_printf(s, "%s ", entry->types[i]); | |
134 | if (!ret) | |
135 | return TRACE_TYPE_PARTIAL_LINE; | |
136 | } | |
137 | /* parameter values */ | |
138 | ret = trace_seq_printf(s, "%s: %lx%s", entry->args[i], | |
139 | trace->args[i], | |
140 | i == entry->nb_args - 1 ? "" : ", "); | |
141 | if (!ret) | |
142 | return TRACE_TYPE_PARTIAL_LINE; | |
143 | } | |
144 | ||
145 | ret = trace_seq_putc(s, ')'); | |
146 | if (!ret) | |
147 | return TRACE_TYPE_PARTIAL_LINE; | |
148 | ||
149 | end: | |
150 | ret = trace_seq_putc(s, '\n'); | |
151 | if (!ret) | |
152 | return TRACE_TYPE_PARTIAL_LINE; | |
153 | ||
154 | return TRACE_TYPE_HANDLED; | |
155 | } | |
156 | ||
157 | enum print_line_t | |
158 | print_syscall_exit(struct trace_iterator *iter, int flags, | |
159 | struct trace_event *event) | |
160 | { | |
161 | struct trace_seq *s = &iter->seq; | |
162 | struct trace_entry *ent = iter->ent; | |
163 | struct syscall_trace_exit *trace; | |
164 | int syscall; | |
165 | struct syscall_metadata *entry; | |
166 | int ret; | |
167 | ||
168 | trace = (typeof(trace))ent; | |
169 | syscall = trace->nr; | |
170 | entry = syscall_nr_to_meta(syscall); | |
171 | ||
172 | if (!entry) { | |
173 | trace_seq_printf(s, "\n"); | |
174 | return TRACE_TYPE_HANDLED; | |
175 | } | |
176 | ||
177 | if (entry->exit_event->event.type != ent->type) { | |
178 | WARN_ON_ONCE(1); | |
179 | return TRACE_TYPE_UNHANDLED; | |
180 | } | |
181 | ||
182 | ret = trace_seq_printf(s, "%s -> 0x%lx\n", entry->name, | |
183 | trace->ret); | |
184 | if (!ret) | |
185 | return TRACE_TYPE_PARTIAL_LINE; | |
186 | ||
187 | return TRACE_TYPE_HANDLED; | |
188 | } | |
189 | ||
190 | extern char *__bad_type_size(void); | |
191 | ||
192 | #define SYSCALL_FIELD(type, name) \ | |
193 | sizeof(type) != sizeof(trace.name) ? \ | |
194 | __bad_type_size() : \ | |
195 | #type, #name, offsetof(typeof(trace), name), \ | |
196 | sizeof(trace.name), is_signed_type(type) | |
197 | ||
198 | static | |
199 | int __set_enter_print_fmt(struct syscall_metadata *entry, char *buf, int len) | |
200 | { | |
201 | int i; | |
202 | int pos = 0; | |
203 | ||
204 | /* When len=0, we just calculate the needed length */ | |
205 | #define LEN_OR_ZERO (len ? len - pos : 0) | |
206 | ||
207 | pos += snprintf(buf + pos, LEN_OR_ZERO, "\""); | |
208 | for (i = 0; i < entry->nb_args; i++) { | |
209 | pos += snprintf(buf + pos, LEN_OR_ZERO, "%s: 0x%%0%zulx%s", | |
210 | entry->args[i], sizeof(unsigned long), | |
211 | i == entry->nb_args - 1 ? "" : ", "); | |
212 | } | |
213 | pos += snprintf(buf + pos, LEN_OR_ZERO, "\""); | |
214 | ||
215 | for (i = 0; i < entry->nb_args; i++) { | |
216 | pos += snprintf(buf + pos, LEN_OR_ZERO, | |
217 | ", ((unsigned long)(REC->%s))", entry->args[i]); | |
218 | } | |
219 | ||
220 | #undef LEN_OR_ZERO | |
221 | ||
222 | /* return the length of print_fmt */ | |
223 | return pos; | |
224 | } | |
225 | ||
226 | static int set_syscall_print_fmt(struct ftrace_event_call *call) | |
227 | { | |
228 | char *print_fmt; | |
229 | int len; | |
230 | struct syscall_metadata *entry = call->data; | |
231 | ||
232 | if (entry->enter_event != call) { | |
233 | call->print_fmt = "\"0x%lx\", REC->ret"; | |
234 | return 0; | |
235 | } | |
236 | ||
237 | /* First: called with 0 length to calculate the needed length */ | |
238 | len = __set_enter_print_fmt(entry, NULL, 0); | |
239 | ||
240 | print_fmt = kmalloc(len + 1, GFP_KERNEL); | |
241 | if (!print_fmt) | |
242 | return -ENOMEM; | |
243 | ||
244 | /* Second: actually write the @print_fmt */ | |
245 | __set_enter_print_fmt(entry, print_fmt, len + 1); | |
246 | call->print_fmt = print_fmt; | |
247 | ||
248 | return 0; | |
249 | } | |
250 | ||
251 | static void free_syscall_print_fmt(struct ftrace_event_call *call) | |
252 | { | |
253 | struct syscall_metadata *entry = call->data; | |
254 | ||
255 | if (entry->enter_event == call) | |
256 | kfree(call->print_fmt); | |
257 | } | |
258 | ||
259 | static int syscall_enter_define_fields(struct ftrace_event_call *call) | |
260 | { | |
261 | struct syscall_trace_enter trace; | |
262 | struct syscall_metadata *meta = call->data; | |
263 | int ret; | |
264 | int i; | |
265 | int offset = offsetof(typeof(trace), args); | |
266 | ||
267 | ret = trace_define_field(call, SYSCALL_FIELD(int, nr), FILTER_OTHER); | |
268 | if (ret) | |
269 | return ret; | |
270 | ||
271 | for (i = 0; i < meta->nb_args; i++) { | |
272 | ret = trace_define_field(call, meta->types[i], | |
273 | meta->args[i], offset, | |
274 | sizeof(unsigned long), 0, | |
275 | FILTER_OTHER); | |
276 | offset += sizeof(unsigned long); | |
277 | } | |
278 | ||
279 | return ret; | |
280 | } | |
281 | ||
282 | static int syscall_exit_define_fields(struct ftrace_event_call *call) | |
283 | { | |
284 | struct syscall_trace_exit trace; | |
285 | int ret; | |
286 | ||
287 | ret = trace_define_field(call, SYSCALL_FIELD(int, nr), FILTER_OTHER); | |
288 | if (ret) | |
289 | return ret; | |
290 | ||
291 | ret = trace_define_field(call, SYSCALL_FIELD(long, ret), | |
292 | FILTER_OTHER); | |
293 | ||
294 | return ret; | |
295 | } | |
296 | ||
297 | void ftrace_syscall_enter(void *ignore, struct pt_regs *regs, long id) | |
298 | { | |
299 | struct syscall_trace_enter *entry; | |
300 | struct syscall_metadata *sys_data; | |
301 | struct ring_buffer_event *event; | |
302 | struct ring_buffer *buffer; | |
303 | int size; | |
304 | int syscall_nr; | |
305 | ||
306 | syscall_nr = syscall_get_nr(current, regs); | |
307 | if (syscall_nr < 0) | |
308 | return; | |
309 | if (!test_bit(syscall_nr, enabled_enter_syscalls)) | |
310 | return; | |
311 | ||
312 | sys_data = syscall_nr_to_meta(syscall_nr); | |
313 | if (!sys_data) | |
314 | return; | |
315 | ||
316 | size = sizeof(*entry) + sizeof(unsigned long) * sys_data->nb_args; | |
317 | ||
318 | event = trace_current_buffer_lock_reserve(&buffer, | |
319 | sys_data->enter_event->event.type, size, 0, 0); | |
320 | if (!event) | |
321 | return; | |
322 | ||
323 | entry = ring_buffer_event_data(event); | |
324 | entry->nr = syscall_nr; | |
325 | syscall_get_arguments(current, regs, 0, sys_data->nb_args, entry->args); | |
326 | ||
327 | if (!filter_current_check_discard(buffer, sys_data->enter_event, | |
328 | entry, event)) | |
329 | trace_current_buffer_unlock_commit(buffer, event, 0, 0); | |
330 | } | |
331 | ||
332 | void ftrace_syscall_exit(void *ignore, struct pt_regs *regs, long ret) | |
333 | { | |
334 | struct syscall_trace_exit *entry; | |
335 | struct syscall_metadata *sys_data; | |
336 | struct ring_buffer_event *event; | |
337 | struct ring_buffer *buffer; | |
338 | int syscall_nr; | |
339 | ||
340 | syscall_nr = syscall_get_nr(current, regs); | |
341 | if (syscall_nr < 0) | |
342 | return; | |
343 | if (!test_bit(syscall_nr, enabled_exit_syscalls)) | |
344 | return; | |
345 | ||
346 | sys_data = syscall_nr_to_meta(syscall_nr); | |
347 | if (!sys_data) | |
348 | return; | |
349 | ||
350 | event = trace_current_buffer_lock_reserve(&buffer, | |
351 | sys_data->exit_event->event.type, sizeof(*entry), 0, 0); | |
352 | if (!event) | |
353 | return; | |
354 | ||
355 | entry = ring_buffer_event_data(event); | |
356 | entry->nr = syscall_nr; | |
357 | entry->ret = syscall_get_return_value(current, regs); | |
358 | ||
359 | if (!filter_current_check_discard(buffer, sys_data->exit_event, | |
360 | entry, event)) | |
361 | trace_current_buffer_unlock_commit(buffer, event, 0, 0); | |
362 | } | |
363 | ||
364 | int reg_event_syscall_enter(struct ftrace_event_call *call) | |
365 | { | |
366 | int ret = 0; | |
367 | int num; | |
368 | ||
369 | num = ((struct syscall_metadata *)call->data)->syscall_nr; | |
370 | if (num < 0 || num >= NR_syscalls) | |
371 | return -ENOSYS; | |
372 | mutex_lock(&syscall_trace_lock); | |
373 | if (!sys_refcount_enter) | |
374 | ret = register_trace_sys_enter(ftrace_syscall_enter, NULL); | |
375 | if (!ret) { | |
376 | set_bit(num, enabled_enter_syscalls); | |
377 | sys_refcount_enter++; | |
378 | } | |
379 | mutex_unlock(&syscall_trace_lock); | |
380 | return ret; | |
381 | } | |
382 | ||
383 | void unreg_event_syscall_enter(struct ftrace_event_call *call) | |
384 | { | |
385 | int num; | |
386 | ||
387 | num = ((struct syscall_metadata *)call->data)->syscall_nr; | |
388 | if (num < 0 || num >= NR_syscalls) | |
389 | return; | |
390 | mutex_lock(&syscall_trace_lock); | |
391 | sys_refcount_enter--; | |
392 | clear_bit(num, enabled_enter_syscalls); | |
393 | if (!sys_refcount_enter) | |
394 | unregister_trace_sys_enter(ftrace_syscall_enter, NULL); | |
395 | mutex_unlock(&syscall_trace_lock); | |
396 | } | |
397 | ||
398 | int reg_event_syscall_exit(struct ftrace_event_call *call) | |
399 | { | |
400 | int ret = 0; | |
401 | int num; | |
402 | ||
403 | num = ((struct syscall_metadata *)call->data)->syscall_nr; | |
404 | if (num < 0 || num >= NR_syscalls) | |
405 | return -ENOSYS; | |
406 | mutex_lock(&syscall_trace_lock); | |
407 | if (!sys_refcount_exit) | |
408 | ret = register_trace_sys_exit(ftrace_syscall_exit, NULL); | |
409 | if (!ret) { | |
410 | set_bit(num, enabled_exit_syscalls); | |
411 | sys_refcount_exit++; | |
412 | } | |
413 | mutex_unlock(&syscall_trace_lock); | |
414 | return ret; | |
415 | } | |
416 | ||
417 | void unreg_event_syscall_exit(struct ftrace_event_call *call) | |
418 | { | |
419 | int num; | |
420 | ||
421 | num = ((struct syscall_metadata *)call->data)->syscall_nr; | |
422 | if (num < 0 || num >= NR_syscalls) | |
423 | return; | |
424 | mutex_lock(&syscall_trace_lock); | |
425 | sys_refcount_exit--; | |
426 | clear_bit(num, enabled_exit_syscalls); | |
427 | if (!sys_refcount_exit) | |
428 | unregister_trace_sys_exit(ftrace_syscall_exit, NULL); | |
429 | mutex_unlock(&syscall_trace_lock); | |
430 | } | |
431 | ||
432 | int init_syscall_trace(struct ftrace_event_call *call) | |
433 | { | |
434 | int id; | |
435 | ||
436 | if (set_syscall_print_fmt(call) < 0) | |
437 | return -ENOMEM; | |
438 | ||
439 | id = trace_event_raw_init(call); | |
440 | ||
441 | if (id < 0) { | |
442 | free_syscall_print_fmt(call); | |
443 | return id; | |
444 | } | |
445 | ||
446 | return id; | |
447 | } | |
448 | ||
449 | unsigned long __init arch_syscall_addr(int nr) | |
450 | { | |
451 | return (unsigned long)sys_call_table[nr]; | |
452 | } | |
453 | ||
454 | int __init init_ftrace_syscalls(void) | |
455 | { | |
456 | struct syscall_metadata *meta; | |
457 | unsigned long addr; | |
458 | int i; | |
459 | ||
460 | syscalls_metadata = kzalloc(sizeof(*syscalls_metadata) * | |
461 | NR_syscalls, GFP_KERNEL); | |
462 | if (!syscalls_metadata) { | |
463 | WARN_ON(1); | |
464 | return -ENOMEM; | |
465 | } | |
466 | ||
467 | for (i = 0; i < NR_syscalls; i++) { | |
468 | addr = arch_syscall_addr(i); | |
469 | meta = find_syscall_meta(addr); | |
470 | if (!meta) | |
471 | continue; | |
472 | ||
473 | meta->syscall_nr = i; | |
474 | syscalls_metadata[i] = meta; | |
475 | } | |
476 | ||
477 | return 0; | |
478 | } | |
479 | core_initcall(init_ftrace_syscalls); | |
480 | ||
481 | #ifdef CONFIG_PERF_EVENTS | |
482 | ||
483 | static DECLARE_BITMAP(enabled_perf_enter_syscalls, NR_syscalls); | |
484 | static DECLARE_BITMAP(enabled_perf_exit_syscalls, NR_syscalls); | |
485 | static int sys_perf_refcount_enter; | |
486 | static int sys_perf_refcount_exit; | |
487 | ||
488 | static void perf_syscall_enter(void *ignore, struct pt_regs *regs, long id) | |
489 | { | |
490 | struct syscall_metadata *sys_data; | |
491 | struct syscall_trace_enter *rec; | |
492 | struct hlist_head *head; | |
493 | int syscall_nr; | |
494 | int rctx; | |
495 | int size; | |
496 | ||
497 | syscall_nr = syscall_get_nr(current, regs); | |
498 | if (!test_bit(syscall_nr, enabled_perf_enter_syscalls)) | |
499 | return; | |
500 | ||
501 | sys_data = syscall_nr_to_meta(syscall_nr); | |
502 | if (!sys_data) | |
503 | return; | |
504 | ||
505 | /* get the size after alignment with the u32 buffer size field */ | |
506 | size = sizeof(unsigned long) * sys_data->nb_args + sizeof(*rec); | |
507 | size = ALIGN(size + sizeof(u32), sizeof(u64)); | |
508 | size -= sizeof(u32); | |
509 | ||
510 | if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, | |
511 | "perf buffer not large enough")) | |
512 | return; | |
513 | ||
514 | rec = (struct syscall_trace_enter *)perf_trace_buf_prepare(size, | |
515 | sys_data->enter_event->event.type, regs, &rctx); | |
516 | if (!rec) | |
517 | return; | |
518 | ||
519 | rec->nr = syscall_nr; | |
520 | syscall_get_arguments(current, regs, 0, sys_data->nb_args, | |
521 | (unsigned long *)&rec->args); | |
522 | ||
523 | head = this_cpu_ptr(sys_data->enter_event->perf_events); | |
524 | perf_trace_buf_submit(rec, size, rctx, 0, 1, regs, head); | |
525 | } | |
526 | ||
527 | int perf_sysenter_enable(struct ftrace_event_call *call) | |
528 | { | |
529 | int ret = 0; | |
530 | int num; | |
531 | ||
532 | num = ((struct syscall_metadata *)call->data)->syscall_nr; | |
533 | ||
534 | mutex_lock(&syscall_trace_lock); | |
535 | if (!sys_perf_refcount_enter) | |
536 | ret = register_trace_sys_enter(perf_syscall_enter, NULL); | |
537 | if (ret) { | |
538 | pr_info("event trace: Could not activate" | |
539 | "syscall entry trace point"); | |
540 | } else { | |
541 | set_bit(num, enabled_perf_enter_syscalls); | |
542 | sys_perf_refcount_enter++; | |
543 | } | |
544 | mutex_unlock(&syscall_trace_lock); | |
545 | return ret; | |
546 | } | |
547 | ||
548 | void perf_sysenter_disable(struct ftrace_event_call *call) | |
549 | { | |
550 | int num; | |
551 | ||
552 | num = ((struct syscall_metadata *)call->data)->syscall_nr; | |
553 | ||
554 | mutex_lock(&syscall_trace_lock); | |
555 | sys_perf_refcount_enter--; | |
556 | clear_bit(num, enabled_perf_enter_syscalls); | |
557 | if (!sys_perf_refcount_enter) | |
558 | unregister_trace_sys_enter(perf_syscall_enter, NULL); | |
559 | mutex_unlock(&syscall_trace_lock); | |
560 | } | |
561 | ||
562 | static void perf_syscall_exit(void *ignore, struct pt_regs *regs, long ret) | |
563 | { | |
564 | struct syscall_metadata *sys_data; | |
565 | struct syscall_trace_exit *rec; | |
566 | struct hlist_head *head; | |
567 | int syscall_nr; | |
568 | int rctx; | |
569 | int size; | |
570 | ||
571 | syscall_nr = syscall_get_nr(current, regs); | |
572 | if (!test_bit(syscall_nr, enabled_perf_exit_syscalls)) | |
573 | return; | |
574 | ||
575 | sys_data = syscall_nr_to_meta(syscall_nr); | |
576 | if (!sys_data) | |
577 | return; | |
578 | ||
579 | /* We can probably do that at build time */ | |
580 | size = ALIGN(sizeof(*rec) + sizeof(u32), sizeof(u64)); | |
581 | size -= sizeof(u32); | |
582 | ||
583 | /* | |
584 | * Impossible, but be paranoid with the future | |
585 | * How to put this check outside runtime? | |
586 | */ | |
587 | if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, | |
588 | "exit event has grown above perf buffer size")) | |
589 | return; | |
590 | ||
591 | rec = (struct syscall_trace_exit *)perf_trace_buf_prepare(size, | |
592 | sys_data->exit_event->event.type, regs, &rctx); | |
593 | if (!rec) | |
594 | return; | |
595 | ||
596 | rec->nr = syscall_nr; | |
597 | rec->ret = syscall_get_return_value(current, regs); | |
598 | ||
599 | head = this_cpu_ptr(sys_data->exit_event->perf_events); | |
600 | perf_trace_buf_submit(rec, size, rctx, 0, 1, regs, head); | |
601 | } | |
602 | ||
603 | int perf_sysexit_enable(struct ftrace_event_call *call) | |
604 | { | |
605 | int ret = 0; | |
606 | int num; | |
607 | ||
608 | num = ((struct syscall_metadata *)call->data)->syscall_nr; | |
609 | ||
610 | mutex_lock(&syscall_trace_lock); | |
611 | if (!sys_perf_refcount_exit) | |
612 | ret = register_trace_sys_exit(perf_syscall_exit, NULL); | |
613 | if (ret) { | |
614 | pr_info("event trace: Could not activate" | |
615 | "syscall exit trace point"); | |
616 | } else { | |
617 | set_bit(num, enabled_perf_exit_syscalls); | |
618 | sys_perf_refcount_exit++; | |
619 | } | |
620 | mutex_unlock(&syscall_trace_lock); | |
621 | return ret; | |
622 | } | |
623 | ||
624 | void perf_sysexit_disable(struct ftrace_event_call *call) | |
625 | { | |
626 | int num; | |
627 | ||
628 | num = ((struct syscall_metadata *)call->data)->syscall_nr; | |
629 | ||
630 | mutex_lock(&syscall_trace_lock); | |
631 | sys_perf_refcount_exit--; | |
632 | clear_bit(num, enabled_perf_exit_syscalls); | |
633 | if (!sys_perf_refcount_exit) | |
634 | unregister_trace_sys_exit(perf_syscall_exit, NULL); | |
635 | mutex_unlock(&syscall_trace_lock); | |
636 | } | |
637 | ||
638 | #endif /* CONFIG_PERF_EVENTS */ | |
639 | ||
640 | static int syscall_enter_register(struct ftrace_event_call *event, | |
641 | enum trace_reg type) | |
642 | { | |
643 | switch (type) { | |
644 | case TRACE_REG_REGISTER: | |
645 | return reg_event_syscall_enter(event); | |
646 | case TRACE_REG_UNREGISTER: | |
647 | unreg_event_syscall_enter(event); | |
648 | return 0; | |
649 | ||
650 | #ifdef CONFIG_PERF_EVENTS | |
651 | case TRACE_REG_PERF_REGISTER: | |
652 | return perf_sysenter_enable(event); | |
653 | case TRACE_REG_PERF_UNREGISTER: | |
654 | perf_sysenter_disable(event); | |
655 | return 0; | |
656 | #endif | |
657 | } | |
658 | return 0; | |
659 | } | |
660 | ||
661 | static int syscall_exit_register(struct ftrace_event_call *event, | |
662 | enum trace_reg type) | |
663 | { | |
664 | switch (type) { | |
665 | case TRACE_REG_REGISTER: | |
666 | return reg_event_syscall_exit(event); | |
667 | case TRACE_REG_UNREGISTER: | |
668 | unreg_event_syscall_exit(event); | |
669 | return 0; | |
670 | ||
671 | #ifdef CONFIG_PERF_EVENTS | |
672 | case TRACE_REG_PERF_REGISTER: | |
673 | return perf_sysexit_enable(event); | |
674 | case TRACE_REG_PERF_UNREGISTER: | |
675 | perf_sysexit_disable(event); | |
676 | return 0; | |
677 | #endif | |
678 | } | |
679 | return 0; | |
680 | } |