Commit | Line | Data |
---|---|---|
47788c58 | 1 | #include <trace/syscall.h> |
1c569f02 | 2 | #include <trace/events/syscalls.h> |
5a0e3ad6 | 3 | #include <linux/slab.h> |
ee08c6ec | 4 | #include <linux/kernel.h> |
fb34a08c | 5 | #include <linux/ftrace.h> |
cdd6c482 | 6 | #include <linux/perf_event.h> |
ee08c6ec FW |
7 | #include <asm/syscall.h> |
8 | ||
9 | #include "trace_output.h" | |
10 | #include "trace.h" | |
11 | ||
5be71b61 | 12 | static DEFINE_MUTEX(syscall_trace_lock); |
fb34a08c JB |
13 | static int sys_refcount_enter; |
14 | static int sys_refcount_exit; | |
57421dbb JB |
15 | static DECLARE_BITMAP(enabled_enter_syscalls, NR_syscalls); |
16 | static DECLARE_BITMAP(enabled_exit_syscalls, NR_syscalls); | |
ee08c6ec | 17 | |
c44fc770 FW |
18 | extern unsigned long __start_syscalls_metadata[]; |
19 | extern unsigned long __stop_syscalls_metadata[]; | |
20 | ||
21 | static struct syscall_metadata **syscalls_metadata; | |
22 | ||
23 | static struct syscall_metadata *find_syscall_meta(unsigned long syscall) | |
24 | { | |
25 | struct syscall_metadata *start; | |
26 | struct syscall_metadata *stop; | |
27 | char str[KSYM_SYMBOL_LEN]; | |
28 | ||
29 | ||
30 | start = (struct syscall_metadata *)__start_syscalls_metadata; | |
31 | stop = (struct syscall_metadata *)__stop_syscalls_metadata; | |
32 | kallsyms_lookup(syscall, NULL, NULL, NULL, str); | |
33 | ||
34 | for ( ; start < stop; start++) { | |
35 | /* | |
36 | * Only compare after the "sys" prefix. Archs that use | |
37 | * syscall wrappers may have syscalls symbols aliases prefixed | |
38 | * with "SyS" instead of "sys", leading to an unwanted | |
39 | * mismatch. | |
40 | */ | |
41 | if (start->name && !strcmp(start->name + 3, str + 3)) | |
42 | return start; | |
43 | } | |
44 | return NULL; | |
45 | } | |
46 | ||
47 | static struct syscall_metadata *syscall_nr_to_meta(int nr) | |
48 | { | |
49 | if (!syscalls_metadata || nr >= NR_syscalls || nr < 0) | |
50 | return NULL; | |
51 | ||
52 | return syscalls_metadata[nr]; | |
53 | } | |
54 | ||
bed1ffca FW |
55 | enum print_line_t |
56 | print_syscall_enter(struct trace_iterator *iter, int flags) | |
57 | { | |
58 | struct trace_seq *s = &iter->seq; | |
59 | struct trace_entry *ent = iter->ent; | |
60 | struct syscall_trace_enter *trace; | |
61 | struct syscall_metadata *entry; | |
62 | int i, ret, syscall; | |
63 | ||
64c12e04 | 64 | trace = (typeof(trace))ent; |
bed1ffca | 65 | syscall = trace->nr; |
bed1ffca | 66 | entry = syscall_nr_to_meta(syscall); |
64c12e04 | 67 | |
bed1ffca FW |
68 | if (!entry) |
69 | goto end; | |
70 | ||
fcc19438 | 71 | if (entry->enter_event->id != ent->type) { |
64c12e04 JB |
72 | WARN_ON_ONCE(1); |
73 | goto end; | |
74 | } | |
75 | ||
bed1ffca FW |
76 | ret = trace_seq_printf(s, "%s(", entry->name); |
77 | if (!ret) | |
78 | return TRACE_TYPE_PARTIAL_LINE; | |
79 | ||
80 | for (i = 0; i < entry->nb_args; i++) { | |
81 | /* parameter types */ | |
ba8b3a40 | 82 | if (trace_flags & TRACE_ITER_VERBOSE) { |
bed1ffca FW |
83 | ret = trace_seq_printf(s, "%s ", entry->types[i]); |
84 | if (!ret) | |
85 | return TRACE_TYPE_PARTIAL_LINE; | |
86 | } | |
87 | /* parameter values */ | |
4539f077 | 88 | ret = trace_seq_printf(s, "%s: %lx%s", entry->args[i], |
bed1ffca | 89 | trace->args[i], |
4539f077 | 90 | i == entry->nb_args - 1 ? "" : ", "); |
bed1ffca FW |
91 | if (!ret) |
92 | return TRACE_TYPE_PARTIAL_LINE; | |
93 | } | |
94 | ||
4539f077 LZ |
95 | ret = trace_seq_putc(s, ')'); |
96 | if (!ret) | |
97 | return TRACE_TYPE_PARTIAL_LINE; | |
98 | ||
bed1ffca | 99 | end: |
4539f077 LZ |
100 | ret = trace_seq_putc(s, '\n'); |
101 | if (!ret) | |
102 | return TRACE_TYPE_PARTIAL_LINE; | |
103 | ||
bed1ffca FW |
104 | return TRACE_TYPE_HANDLED; |
105 | } | |
106 | ||
107 | enum print_line_t | |
108 | print_syscall_exit(struct trace_iterator *iter, int flags) | |
109 | { | |
110 | struct trace_seq *s = &iter->seq; | |
111 | struct trace_entry *ent = iter->ent; | |
112 | struct syscall_trace_exit *trace; | |
113 | int syscall; | |
114 | struct syscall_metadata *entry; | |
115 | int ret; | |
116 | ||
64c12e04 | 117 | trace = (typeof(trace))ent; |
bed1ffca | 118 | syscall = trace->nr; |
bed1ffca | 119 | entry = syscall_nr_to_meta(syscall); |
64c12e04 | 120 | |
bed1ffca FW |
121 | if (!entry) { |
122 | trace_seq_printf(s, "\n"); | |
123 | return TRACE_TYPE_HANDLED; | |
124 | } | |
125 | ||
fcc19438 | 126 | if (entry->exit_event->id != ent->type) { |
64c12e04 JB |
127 | WARN_ON_ONCE(1); |
128 | return TRACE_TYPE_UNHANDLED; | |
129 | } | |
130 | ||
bed1ffca FW |
131 | ret = trace_seq_printf(s, "%s -> 0x%lx\n", entry->name, |
132 | trace->ret); | |
133 | if (!ret) | |
134 | return TRACE_TYPE_PARTIAL_LINE; | |
135 | ||
136 | return TRACE_TYPE_HANDLED; | |
137 | } | |
138 | ||
e6971969 LZ |
139 | extern char *__bad_type_size(void); |
140 | ||
141 | #define SYSCALL_FIELD(type, name) \ | |
142 | sizeof(type) != sizeof(trace.name) ? \ | |
143 | __bad_type_size() : \ | |
26a50744 TZ |
144 | #type, #name, offsetof(typeof(trace), name), \ |
145 | sizeof(trace.name), is_signed_type(type) | |
e6971969 | 146 | |
50307a45 LJ |
147 | static |
148 | int __set_enter_print_fmt(struct syscall_metadata *entry, char *buf, int len) | |
149 | { | |
150 | int i; | |
151 | int pos = 0; | |
152 | ||
153 | /* When len=0, we just calculate the needed length */ | |
154 | #define LEN_OR_ZERO (len ? len - pos : 0) | |
155 | ||
156 | pos += snprintf(buf + pos, LEN_OR_ZERO, "\""); | |
157 | for (i = 0; i < entry->nb_args; i++) { | |
158 | pos += snprintf(buf + pos, LEN_OR_ZERO, "%s: 0x%%0%zulx%s", | |
159 | entry->args[i], sizeof(unsigned long), | |
160 | i == entry->nb_args - 1 ? "" : ", "); | |
161 | } | |
162 | pos += snprintf(buf + pos, LEN_OR_ZERO, "\""); | |
163 | ||
164 | for (i = 0; i < entry->nb_args; i++) { | |
165 | pos += snprintf(buf + pos, LEN_OR_ZERO, | |
166 | ", ((unsigned long)(REC->%s))", entry->args[i]); | |
167 | } | |
168 | ||
169 | #undef LEN_OR_ZERO | |
170 | ||
171 | /* return the length of print_fmt */ | |
172 | return pos; | |
173 | } | |
174 | ||
175 | static int set_syscall_print_fmt(struct ftrace_event_call *call) | |
176 | { | |
177 | char *print_fmt; | |
178 | int len; | |
179 | struct syscall_metadata *entry = call->data; | |
180 | ||
181 | if (entry->enter_event != call) { | |
182 | call->print_fmt = "\"0x%lx\", REC->ret"; | |
183 | return 0; | |
184 | } | |
185 | ||
186 | /* First: called with 0 length to calculate the needed length */ | |
187 | len = __set_enter_print_fmt(entry, NULL, 0); | |
188 | ||
189 | print_fmt = kmalloc(len + 1, GFP_KERNEL); | |
190 | if (!print_fmt) | |
191 | return -ENOMEM; | |
192 | ||
193 | /* Second: actually write the @print_fmt */ | |
194 | __set_enter_print_fmt(entry, print_fmt, len + 1); | |
195 | call->print_fmt = print_fmt; | |
196 | ||
197 | return 0; | |
198 | } | |
199 | ||
200 | static void free_syscall_print_fmt(struct ftrace_event_call *call) | |
201 | { | |
202 | struct syscall_metadata *entry = call->data; | |
203 | ||
204 | if (entry->enter_event == call) | |
205 | kfree(call->print_fmt); | |
206 | } | |
207 | ||
540b7b8d LZ |
208 | int syscall_enter_define_fields(struct ftrace_event_call *call) |
209 | { | |
210 | struct syscall_trace_enter trace; | |
31c16b13 | 211 | struct syscall_metadata *meta = call->data; |
540b7b8d | 212 | int ret; |
540b7b8d LZ |
213 | int i; |
214 | int offset = offsetof(typeof(trace), args); | |
215 | ||
0f1ef51d LJ |
216 | ret = trace_define_field(call, SYSCALL_FIELD(int, nr), FILTER_OTHER); |
217 | if (ret) | |
218 | return ret; | |
219 | ||
540b7b8d | 220 | for (i = 0; i < meta->nb_args; i++) { |
aeaeae11 FW |
221 | ret = trace_define_field(call, meta->types[i], |
222 | meta->args[i], offset, | |
43b51ead LZ |
223 | sizeof(unsigned long), 0, |
224 | FILTER_OTHER); | |
540b7b8d LZ |
225 | offset += sizeof(unsigned long); |
226 | } | |
227 | ||
228 | return ret; | |
229 | } | |
230 | ||
231 | int syscall_exit_define_fields(struct ftrace_event_call *call) | |
232 | { | |
233 | struct syscall_trace_exit trace; | |
234 | int ret; | |
235 | ||
0f1ef51d LJ |
236 | ret = trace_define_field(call, SYSCALL_FIELD(int, nr), FILTER_OTHER); |
237 | if (ret) | |
238 | return ret; | |
239 | ||
26a50744 | 240 | ret = trace_define_field(call, SYSCALL_FIELD(long, ret), |
43b51ead | 241 | FILTER_OTHER); |
540b7b8d LZ |
242 | |
243 | return ret; | |
244 | } | |
245 | ||
fb34a08c | 246 | void ftrace_syscall_enter(struct pt_regs *regs, long id) |
ee08c6ec | 247 | { |
bed1ffca FW |
248 | struct syscall_trace_enter *entry; |
249 | struct syscall_metadata *sys_data; | |
250 | struct ring_buffer_event *event; | |
e77405ad | 251 | struct ring_buffer *buffer; |
bed1ffca | 252 | int size; |
ee08c6ec FW |
253 | int syscall_nr; |
254 | ||
255 | syscall_nr = syscall_get_nr(current, regs); | |
cd0980fc HB |
256 | if (syscall_nr < 0) |
257 | return; | |
fb34a08c JB |
258 | if (!test_bit(syscall_nr, enabled_enter_syscalls)) |
259 | return; | |
ee08c6ec | 260 | |
bed1ffca FW |
261 | sys_data = syscall_nr_to_meta(syscall_nr); |
262 | if (!sys_data) | |
263 | return; | |
264 | ||
265 | size = sizeof(*entry) + sizeof(unsigned long) * sys_data->nb_args; | |
266 | ||
fcc19438 LJ |
267 | event = trace_current_buffer_lock_reserve(&buffer, |
268 | sys_data->enter_event->id, size, 0, 0); | |
bed1ffca FW |
269 | if (!event) |
270 | return; | |
271 | ||
272 | entry = ring_buffer_event_data(event); | |
273 | entry->nr = syscall_nr; | |
274 | syscall_get_arguments(current, regs, 0, sys_data->nb_args, entry->args); | |
275 | ||
e77405ad SR |
276 | if (!filter_current_check_discard(buffer, sys_data->enter_event, |
277 | entry, event)) | |
278 | trace_current_buffer_unlock_commit(buffer, event, 0, 0); | |
ee08c6ec FW |
279 | } |
280 | ||
fb34a08c | 281 | void ftrace_syscall_exit(struct pt_regs *regs, long ret) |
ee08c6ec | 282 | { |
bed1ffca FW |
283 | struct syscall_trace_exit *entry; |
284 | struct syscall_metadata *sys_data; | |
285 | struct ring_buffer_event *event; | |
e77405ad | 286 | struct ring_buffer *buffer; |
ee08c6ec FW |
287 | int syscall_nr; |
288 | ||
289 | syscall_nr = syscall_get_nr(current, regs); | |
cd0980fc HB |
290 | if (syscall_nr < 0) |
291 | return; | |
fb34a08c JB |
292 | if (!test_bit(syscall_nr, enabled_exit_syscalls)) |
293 | return; | |
ee08c6ec | 294 | |
bed1ffca FW |
295 | sys_data = syscall_nr_to_meta(syscall_nr); |
296 | if (!sys_data) | |
297 | return; | |
298 | ||
fcc19438 LJ |
299 | event = trace_current_buffer_lock_reserve(&buffer, |
300 | sys_data->exit_event->id, sizeof(*entry), 0, 0); | |
bed1ffca FW |
301 | if (!event) |
302 | return; | |
303 | ||
304 | entry = ring_buffer_event_data(event); | |
305 | entry->nr = syscall_nr; | |
306 | entry->ret = syscall_get_return_value(current, regs); | |
307 | ||
e77405ad SR |
308 | if (!filter_current_check_discard(buffer, sys_data->exit_event, |
309 | entry, event)) | |
310 | trace_current_buffer_unlock_commit(buffer, event, 0, 0); | |
ee08c6ec FW |
311 | } |
312 | ||
bd1a5c84 | 313 | int reg_event_syscall_enter(struct ftrace_event_call *call) |
ee08c6ec | 314 | { |
fb34a08c JB |
315 | int ret = 0; |
316 | int num; | |
fb34a08c | 317 | |
c252f657 | 318 | num = ((struct syscall_metadata *)call->data)->syscall_nr; |
57421dbb | 319 | if (num < 0 || num >= NR_syscalls) |
fb34a08c JB |
320 | return -ENOSYS; |
321 | mutex_lock(&syscall_trace_lock); | |
322 | if (!sys_refcount_enter) | |
1c569f02 | 323 | ret = register_trace_sys_enter(ftrace_syscall_enter); |
3b8e4273 | 324 | if (!ret) { |
fb34a08c JB |
325 | set_bit(num, enabled_enter_syscalls); |
326 | sys_refcount_enter++; | |
327 | } | |
328 | mutex_unlock(&syscall_trace_lock); | |
329 | return ret; | |
ee08c6ec FW |
330 | } |
331 | ||
bd1a5c84 | 332 | void unreg_event_syscall_enter(struct ftrace_event_call *call) |
ee08c6ec | 333 | { |
fb34a08c | 334 | int num; |
ee08c6ec | 335 | |
c252f657 | 336 | num = ((struct syscall_metadata *)call->data)->syscall_nr; |
57421dbb | 337 | if (num < 0 || num >= NR_syscalls) |
fb34a08c JB |
338 | return; |
339 | mutex_lock(&syscall_trace_lock); | |
340 | sys_refcount_enter--; | |
341 | clear_bit(num, enabled_enter_syscalls); | |
342 | if (!sys_refcount_enter) | |
1c569f02 | 343 | unregister_trace_sys_enter(ftrace_syscall_enter); |
fb34a08c JB |
344 | mutex_unlock(&syscall_trace_lock); |
345 | } | |
ee08c6ec | 346 | |
bd1a5c84 | 347 | int reg_event_syscall_exit(struct ftrace_event_call *call) |
ee08c6ec | 348 | { |
fb34a08c JB |
349 | int ret = 0; |
350 | int num; | |
fb34a08c | 351 | |
c252f657 | 352 | num = ((struct syscall_metadata *)call->data)->syscall_nr; |
57421dbb | 353 | if (num < 0 || num >= NR_syscalls) |
fb34a08c JB |
354 | return -ENOSYS; |
355 | mutex_lock(&syscall_trace_lock); | |
356 | if (!sys_refcount_exit) | |
1c569f02 | 357 | ret = register_trace_sys_exit(ftrace_syscall_exit); |
3b8e4273 | 358 | if (!ret) { |
fb34a08c JB |
359 | set_bit(num, enabled_exit_syscalls); |
360 | sys_refcount_exit++; | |
ee08c6ec | 361 | } |
fb34a08c JB |
362 | mutex_unlock(&syscall_trace_lock); |
363 | return ret; | |
364 | } | |
ee08c6ec | 365 | |
bd1a5c84 | 366 | void unreg_event_syscall_exit(struct ftrace_event_call *call) |
fb34a08c JB |
367 | { |
368 | int num; | |
ee08c6ec | 369 | |
c252f657 | 370 | num = ((struct syscall_metadata *)call->data)->syscall_nr; |
57421dbb | 371 | if (num < 0 || num >= NR_syscalls) |
fb34a08c JB |
372 | return; |
373 | mutex_lock(&syscall_trace_lock); | |
374 | sys_refcount_exit--; | |
375 | clear_bit(num, enabled_exit_syscalls); | |
376 | if (!sys_refcount_exit) | |
1c569f02 | 377 | unregister_trace_sys_exit(ftrace_syscall_exit); |
fb34a08c | 378 | mutex_unlock(&syscall_trace_lock); |
ee08c6ec | 379 | } |
fb34a08c | 380 | |
a1301da0 LJ |
381 | int init_syscall_trace(struct ftrace_event_call *call) |
382 | { | |
383 | int id; | |
384 | ||
50307a45 LJ |
385 | if (set_syscall_print_fmt(call) < 0) |
386 | return -ENOMEM; | |
387 | ||
c7ef3a90 SR |
388 | id = trace_event_raw_init(call); |
389 | ||
390 | if (id < 0) { | |
50307a45 | 391 | free_syscall_print_fmt(call); |
c7ef3a90 | 392 | return id; |
50307a45 | 393 | } |
c7ef3a90 SR |
394 | |
395 | return id; | |
a1301da0 LJ |
396 | } |
397 | ||
e7b8e675 MF |
398 | unsigned long __init arch_syscall_addr(int nr) |
399 | { | |
400 | return (unsigned long)sys_call_table[nr]; | |
401 | } | |
402 | ||
c44fc770 FW |
403 | int __init init_ftrace_syscalls(void) |
404 | { | |
405 | struct syscall_metadata *meta; | |
406 | unsigned long addr; | |
407 | int i; | |
408 | ||
409 | syscalls_metadata = kzalloc(sizeof(*syscalls_metadata) * | |
410 | NR_syscalls, GFP_KERNEL); | |
411 | if (!syscalls_metadata) { | |
412 | WARN_ON(1); | |
413 | return -ENOMEM; | |
414 | } | |
415 | ||
416 | for (i = 0; i < NR_syscalls; i++) { | |
417 | addr = arch_syscall_addr(i); | |
418 | meta = find_syscall_meta(addr); | |
c252f657 LJ |
419 | if (!meta) |
420 | continue; | |
421 | ||
422 | meta->syscall_nr = i; | |
c44fc770 FW |
423 | syscalls_metadata[i] = meta; |
424 | } | |
425 | ||
426 | return 0; | |
427 | } | |
428 | core_initcall(init_ftrace_syscalls); | |
429 | ||
07b139c8 | 430 | #ifdef CONFIG_PERF_EVENTS |
19007a67 | 431 | |
97d5a220 FW |
432 | static DECLARE_BITMAP(enabled_perf_enter_syscalls, NR_syscalls); |
433 | static DECLARE_BITMAP(enabled_perf_exit_syscalls, NR_syscalls); | |
434 | static int sys_perf_refcount_enter; | |
435 | static int sys_perf_refcount_exit; | |
f4b5ffcc | 436 | |
97d5a220 | 437 | static void perf_syscall_enter(struct pt_regs *regs, long id) |
f4b5ffcc JB |
438 | { |
439 | struct syscall_metadata *sys_data; | |
20ab4425 FW |
440 | struct syscall_trace_enter *rec; |
441 | unsigned long flags; | |
f4b5ffcc | 442 | int syscall_nr; |
4ed7c92d | 443 | int rctx; |
19007a67 | 444 | int size; |
f4b5ffcc JB |
445 | |
446 | syscall_nr = syscall_get_nr(current, regs); | |
97d5a220 | 447 | if (!test_bit(syscall_nr, enabled_perf_enter_syscalls)) |
f4b5ffcc JB |
448 | return; |
449 | ||
450 | sys_data = syscall_nr_to_meta(syscall_nr); | |
451 | if (!sys_data) | |
452 | return; | |
453 | ||
19007a67 FW |
454 | /* get the size after alignment with the u32 buffer size field */ |
455 | size = sizeof(unsigned long) * sys_data->nb_args + sizeof(*rec); | |
456 | size = ALIGN(size + sizeof(u32), sizeof(u64)); | |
457 | size -= sizeof(u32); | |
458 | ||
97d5a220 FW |
459 | if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, |
460 | "perf buffer not large enough")) | |
20ab4425 FW |
461 | return; |
462 | ||
97d5a220 | 463 | rec = (struct syscall_trace_enter *)perf_trace_buf_prepare(size, |
430ad5a6 XG |
464 | sys_data->enter_event->id, &rctx, &flags); |
465 | if (!rec) | |
466 | return; | |
20ab4425 | 467 | |
20ab4425 FW |
468 | rec->nr = syscall_nr; |
469 | syscall_get_arguments(current, regs, 0, sys_data->nb_args, | |
470 | (unsigned long *)&rec->args); | |
97d5a220 | 471 | perf_trace_buf_submit(rec, size, rctx, 0, 1, flags, regs); |
f4b5ffcc JB |
472 | } |
473 | ||
97d5a220 | 474 | int perf_sysenter_enable(struct ftrace_event_call *call) |
f4b5ffcc JB |
475 | { |
476 | int ret = 0; | |
477 | int num; | |
478 | ||
3bbe84e9 | 479 | num = ((struct syscall_metadata *)call->data)->syscall_nr; |
f4b5ffcc JB |
480 | |
481 | mutex_lock(&syscall_trace_lock); | |
97d5a220 FW |
482 | if (!sys_perf_refcount_enter) |
483 | ret = register_trace_sys_enter(perf_syscall_enter); | |
f4b5ffcc JB |
484 | if (ret) { |
485 | pr_info("event trace: Could not activate" | |
486 | "syscall entry trace point"); | |
487 | } else { | |
97d5a220 FW |
488 | set_bit(num, enabled_perf_enter_syscalls); |
489 | sys_perf_refcount_enter++; | |
f4b5ffcc JB |
490 | } |
491 | mutex_unlock(&syscall_trace_lock); | |
492 | return ret; | |
493 | } | |
494 | ||
97d5a220 | 495 | void perf_sysenter_disable(struct ftrace_event_call *call) |
f4b5ffcc JB |
496 | { |
497 | int num; | |
498 | ||
3bbe84e9 | 499 | num = ((struct syscall_metadata *)call->data)->syscall_nr; |
f4b5ffcc JB |
500 | |
501 | mutex_lock(&syscall_trace_lock); | |
97d5a220 FW |
502 | sys_perf_refcount_enter--; |
503 | clear_bit(num, enabled_perf_enter_syscalls); | |
504 | if (!sys_perf_refcount_enter) | |
505 | unregister_trace_sys_enter(perf_syscall_enter); | |
f4b5ffcc JB |
506 | mutex_unlock(&syscall_trace_lock); |
507 | } | |
508 | ||
97d5a220 | 509 | static void perf_syscall_exit(struct pt_regs *regs, long ret) |
f4b5ffcc JB |
510 | { |
511 | struct syscall_metadata *sys_data; | |
20ab4425 FW |
512 | struct syscall_trace_exit *rec; |
513 | unsigned long flags; | |
f4b5ffcc | 514 | int syscall_nr; |
4ed7c92d | 515 | int rctx; |
20ab4425 | 516 | int size; |
f4b5ffcc JB |
517 | |
518 | syscall_nr = syscall_get_nr(current, regs); | |
97d5a220 | 519 | if (!test_bit(syscall_nr, enabled_perf_exit_syscalls)) |
f4b5ffcc JB |
520 | return; |
521 | ||
522 | sys_data = syscall_nr_to_meta(syscall_nr); | |
523 | if (!sys_data) | |
524 | return; | |
525 | ||
20ab4425 FW |
526 | /* We can probably do that at build time */ |
527 | size = ALIGN(sizeof(*rec) + sizeof(u32), sizeof(u64)); | |
528 | size -= sizeof(u32); | |
19007a67 | 529 | |
20ab4425 FW |
530 | /* |
531 | * Impossible, but be paranoid with the future | |
532 | * How to put this check outside runtime? | |
533 | */ | |
97d5a220 FW |
534 | if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, |
535 | "exit event has grown above perf buffer size")) | |
20ab4425 FW |
536 | return; |
537 | ||
97d5a220 | 538 | rec = (struct syscall_trace_exit *)perf_trace_buf_prepare(size, |
430ad5a6 XG |
539 | sys_data->exit_event->id, &rctx, &flags); |
540 | if (!rec) | |
541 | return; | |
20ab4425 | 542 | |
20ab4425 FW |
543 | rec->nr = syscall_nr; |
544 | rec->ret = syscall_get_return_value(current, regs); | |
545 | ||
97d5a220 | 546 | perf_trace_buf_submit(rec, size, rctx, 0, 1, flags, regs); |
f4b5ffcc JB |
547 | } |
548 | ||
97d5a220 | 549 | int perf_sysexit_enable(struct ftrace_event_call *call) |
f4b5ffcc JB |
550 | { |
551 | int ret = 0; | |
552 | int num; | |
553 | ||
3bbe84e9 | 554 | num = ((struct syscall_metadata *)call->data)->syscall_nr; |
f4b5ffcc JB |
555 | |
556 | mutex_lock(&syscall_trace_lock); | |
97d5a220 FW |
557 | if (!sys_perf_refcount_exit) |
558 | ret = register_trace_sys_exit(perf_syscall_exit); | |
f4b5ffcc JB |
559 | if (ret) { |
560 | pr_info("event trace: Could not activate" | |
6574658b | 561 | "syscall exit trace point"); |
f4b5ffcc | 562 | } else { |
97d5a220 FW |
563 | set_bit(num, enabled_perf_exit_syscalls); |
564 | sys_perf_refcount_exit++; | |
f4b5ffcc JB |
565 | } |
566 | mutex_unlock(&syscall_trace_lock); | |
567 | return ret; | |
568 | } | |
569 | ||
97d5a220 | 570 | void perf_sysexit_disable(struct ftrace_event_call *call) |
f4b5ffcc JB |
571 | { |
572 | int num; | |
573 | ||
3bbe84e9 | 574 | num = ((struct syscall_metadata *)call->data)->syscall_nr; |
f4b5ffcc JB |
575 | |
576 | mutex_lock(&syscall_trace_lock); | |
97d5a220 FW |
577 | sys_perf_refcount_exit--; |
578 | clear_bit(num, enabled_perf_exit_syscalls); | |
579 | if (!sys_perf_refcount_exit) | |
580 | unregister_trace_sys_exit(perf_syscall_exit); | |
f4b5ffcc JB |
581 | mutex_unlock(&syscall_trace_lock); |
582 | } | |
583 | ||
07b139c8 | 584 | #endif /* CONFIG_PERF_EVENTS */ |
f4b5ffcc | 585 |