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Commit | Line | Data |
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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 | |
2239291a SR |
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 | struct ftrace_event_class event_class_syscall_enter = { | |
24 | .system = "syscalls", | |
25 | .reg = syscall_enter_register | |
26 | }; | |
27 | ||
28 | struct ftrace_event_class event_class_syscall_exit = { | |
29 | .system = "syscalls", | |
30 | .reg = syscall_exit_register | |
8f082018 SR |
31 | }; |
32 | ||
c44fc770 FW |
33 | extern unsigned long __start_syscalls_metadata[]; |
34 | extern unsigned long __stop_syscalls_metadata[]; | |
35 | ||
36 | static struct syscall_metadata **syscalls_metadata; | |
37 | ||
38 | static struct syscall_metadata *find_syscall_meta(unsigned long syscall) | |
39 | { | |
40 | struct syscall_metadata *start; | |
41 | struct syscall_metadata *stop; | |
42 | char str[KSYM_SYMBOL_LEN]; | |
43 | ||
44 | ||
45 | start = (struct syscall_metadata *)__start_syscalls_metadata; | |
46 | stop = (struct syscall_metadata *)__stop_syscalls_metadata; | |
47 | kallsyms_lookup(syscall, NULL, NULL, NULL, str); | |
48 | ||
49 | for ( ; start < stop; start++) { | |
50 | /* | |
51 | * Only compare after the "sys" prefix. Archs that use | |
52 | * syscall wrappers may have syscalls symbols aliases prefixed | |
53 | * with "SyS" instead of "sys", leading to an unwanted | |
54 | * mismatch. | |
55 | */ | |
56 | if (start->name && !strcmp(start->name + 3, str + 3)) | |
57 | return start; | |
58 | } | |
59 | return NULL; | |
60 | } | |
61 | ||
62 | static struct syscall_metadata *syscall_nr_to_meta(int nr) | |
63 | { | |
64 | if (!syscalls_metadata || nr >= NR_syscalls || nr < 0) | |
65 | return NULL; | |
66 | ||
67 | return syscalls_metadata[nr]; | |
68 | } | |
69 | ||
bed1ffca FW |
70 | enum print_line_t |
71 | print_syscall_enter(struct trace_iterator *iter, int flags) | |
72 | { | |
73 | struct trace_seq *s = &iter->seq; | |
74 | struct trace_entry *ent = iter->ent; | |
75 | struct syscall_trace_enter *trace; | |
76 | struct syscall_metadata *entry; | |
77 | int i, ret, syscall; | |
78 | ||
64c12e04 | 79 | trace = (typeof(trace))ent; |
bed1ffca | 80 | syscall = trace->nr; |
bed1ffca | 81 | entry = syscall_nr_to_meta(syscall); |
64c12e04 | 82 | |
bed1ffca FW |
83 | if (!entry) |
84 | goto end; | |
85 | ||
fcc19438 | 86 | if (entry->enter_event->id != ent->type) { |
64c12e04 JB |
87 | WARN_ON_ONCE(1); |
88 | goto end; | |
89 | } | |
90 | ||
bed1ffca FW |
91 | ret = trace_seq_printf(s, "%s(", entry->name); |
92 | if (!ret) | |
93 | return TRACE_TYPE_PARTIAL_LINE; | |
94 | ||
95 | for (i = 0; i < entry->nb_args; i++) { | |
96 | /* parameter types */ | |
ba8b3a40 | 97 | if (trace_flags & TRACE_ITER_VERBOSE) { |
bed1ffca FW |
98 | ret = trace_seq_printf(s, "%s ", entry->types[i]); |
99 | if (!ret) | |
100 | return TRACE_TYPE_PARTIAL_LINE; | |
101 | } | |
102 | /* parameter values */ | |
4539f077 | 103 | ret = trace_seq_printf(s, "%s: %lx%s", entry->args[i], |
bed1ffca | 104 | trace->args[i], |
4539f077 | 105 | i == entry->nb_args - 1 ? "" : ", "); |
bed1ffca FW |
106 | if (!ret) |
107 | return TRACE_TYPE_PARTIAL_LINE; | |
108 | } | |
109 | ||
4539f077 LZ |
110 | ret = trace_seq_putc(s, ')'); |
111 | if (!ret) | |
112 | return TRACE_TYPE_PARTIAL_LINE; | |
113 | ||
bed1ffca | 114 | end: |
4539f077 LZ |
115 | ret = trace_seq_putc(s, '\n'); |
116 | if (!ret) | |
117 | return TRACE_TYPE_PARTIAL_LINE; | |
118 | ||
bed1ffca FW |
119 | return TRACE_TYPE_HANDLED; |
120 | } | |
121 | ||
122 | enum print_line_t | |
123 | print_syscall_exit(struct trace_iterator *iter, int flags) | |
124 | { | |
125 | struct trace_seq *s = &iter->seq; | |
126 | struct trace_entry *ent = iter->ent; | |
127 | struct syscall_trace_exit *trace; | |
128 | int syscall; | |
129 | struct syscall_metadata *entry; | |
130 | int ret; | |
131 | ||
64c12e04 | 132 | trace = (typeof(trace))ent; |
bed1ffca | 133 | syscall = trace->nr; |
bed1ffca | 134 | entry = syscall_nr_to_meta(syscall); |
64c12e04 | 135 | |
bed1ffca FW |
136 | if (!entry) { |
137 | trace_seq_printf(s, "\n"); | |
138 | return TRACE_TYPE_HANDLED; | |
139 | } | |
140 | ||
fcc19438 | 141 | if (entry->exit_event->id != ent->type) { |
64c12e04 JB |
142 | WARN_ON_ONCE(1); |
143 | return TRACE_TYPE_UNHANDLED; | |
144 | } | |
145 | ||
bed1ffca FW |
146 | ret = trace_seq_printf(s, "%s -> 0x%lx\n", entry->name, |
147 | trace->ret); | |
148 | if (!ret) | |
149 | return TRACE_TYPE_PARTIAL_LINE; | |
150 | ||
151 | return TRACE_TYPE_HANDLED; | |
152 | } | |
153 | ||
e6971969 LZ |
154 | extern char *__bad_type_size(void); |
155 | ||
156 | #define SYSCALL_FIELD(type, name) \ | |
157 | sizeof(type) != sizeof(trace.name) ? \ | |
158 | __bad_type_size() : \ | |
26a50744 TZ |
159 | #type, #name, offsetof(typeof(trace), name), \ |
160 | sizeof(trace.name), is_signed_type(type) | |
e6971969 | 161 | |
50307a45 LJ |
162 | static |
163 | int __set_enter_print_fmt(struct syscall_metadata *entry, char *buf, int len) | |
164 | { | |
165 | int i; | |
166 | int pos = 0; | |
167 | ||
168 | /* When len=0, we just calculate the needed length */ | |
169 | #define LEN_OR_ZERO (len ? len - pos : 0) | |
170 | ||
171 | pos += snprintf(buf + pos, LEN_OR_ZERO, "\""); | |
172 | for (i = 0; i < entry->nb_args; i++) { | |
173 | pos += snprintf(buf + pos, LEN_OR_ZERO, "%s: 0x%%0%zulx%s", | |
174 | entry->args[i], sizeof(unsigned long), | |
175 | i == entry->nb_args - 1 ? "" : ", "); | |
176 | } | |
177 | pos += snprintf(buf + pos, LEN_OR_ZERO, "\""); | |
178 | ||
179 | for (i = 0; i < entry->nb_args; i++) { | |
180 | pos += snprintf(buf + pos, LEN_OR_ZERO, | |
181 | ", ((unsigned long)(REC->%s))", entry->args[i]); | |
182 | } | |
183 | ||
184 | #undef LEN_OR_ZERO | |
185 | ||
186 | /* return the length of print_fmt */ | |
187 | return pos; | |
188 | } | |
189 | ||
190 | static int set_syscall_print_fmt(struct ftrace_event_call *call) | |
191 | { | |
192 | char *print_fmt; | |
193 | int len; | |
194 | struct syscall_metadata *entry = call->data; | |
195 | ||
196 | if (entry->enter_event != call) { | |
197 | call->print_fmt = "\"0x%lx\", REC->ret"; | |
198 | return 0; | |
199 | } | |
200 | ||
201 | /* First: called with 0 length to calculate the needed length */ | |
202 | len = __set_enter_print_fmt(entry, NULL, 0); | |
203 | ||
204 | print_fmt = kmalloc(len + 1, GFP_KERNEL); | |
205 | if (!print_fmt) | |
206 | return -ENOMEM; | |
207 | ||
208 | /* Second: actually write the @print_fmt */ | |
209 | __set_enter_print_fmt(entry, print_fmt, len + 1); | |
210 | call->print_fmt = print_fmt; | |
211 | ||
212 | return 0; | |
213 | } | |
214 | ||
215 | static void free_syscall_print_fmt(struct ftrace_event_call *call) | |
216 | { | |
217 | struct syscall_metadata *entry = call->data; | |
218 | ||
219 | if (entry->enter_event == call) | |
220 | kfree(call->print_fmt); | |
221 | } | |
222 | ||
540b7b8d LZ |
223 | int syscall_enter_define_fields(struct ftrace_event_call *call) |
224 | { | |
225 | struct syscall_trace_enter trace; | |
31c16b13 | 226 | struct syscall_metadata *meta = call->data; |
540b7b8d | 227 | int ret; |
540b7b8d LZ |
228 | int i; |
229 | int offset = offsetof(typeof(trace), args); | |
230 | ||
0f1ef51d LJ |
231 | ret = trace_define_field(call, SYSCALL_FIELD(int, nr), FILTER_OTHER); |
232 | if (ret) | |
233 | return ret; | |
234 | ||
540b7b8d | 235 | for (i = 0; i < meta->nb_args; i++) { |
aeaeae11 FW |
236 | ret = trace_define_field(call, meta->types[i], |
237 | meta->args[i], offset, | |
43b51ead LZ |
238 | sizeof(unsigned long), 0, |
239 | FILTER_OTHER); | |
540b7b8d LZ |
240 | offset += sizeof(unsigned long); |
241 | } | |
242 | ||
243 | return ret; | |
244 | } | |
245 | ||
246 | int syscall_exit_define_fields(struct ftrace_event_call *call) | |
247 | { | |
248 | struct syscall_trace_exit trace; | |
249 | int ret; | |
250 | ||
0f1ef51d LJ |
251 | ret = trace_define_field(call, SYSCALL_FIELD(int, nr), FILTER_OTHER); |
252 | if (ret) | |
253 | return ret; | |
254 | ||
26a50744 | 255 | ret = trace_define_field(call, SYSCALL_FIELD(long, ret), |
43b51ead | 256 | FILTER_OTHER); |
540b7b8d LZ |
257 | |
258 | return ret; | |
259 | } | |
260 | ||
38516ab5 | 261 | void ftrace_syscall_enter(void *ignore, struct pt_regs *regs, long id) |
ee08c6ec | 262 | { |
bed1ffca FW |
263 | struct syscall_trace_enter *entry; |
264 | struct syscall_metadata *sys_data; | |
265 | struct ring_buffer_event *event; | |
e77405ad | 266 | struct ring_buffer *buffer; |
bed1ffca | 267 | int size; |
ee08c6ec FW |
268 | int syscall_nr; |
269 | ||
270 | syscall_nr = syscall_get_nr(current, regs); | |
cd0980fc HB |
271 | if (syscall_nr < 0) |
272 | return; | |
fb34a08c JB |
273 | if (!test_bit(syscall_nr, enabled_enter_syscalls)) |
274 | return; | |
ee08c6ec | 275 | |
bed1ffca FW |
276 | sys_data = syscall_nr_to_meta(syscall_nr); |
277 | if (!sys_data) | |
278 | return; | |
279 | ||
280 | size = sizeof(*entry) + sizeof(unsigned long) * sys_data->nb_args; | |
281 | ||
fcc19438 LJ |
282 | event = trace_current_buffer_lock_reserve(&buffer, |
283 | sys_data->enter_event->id, size, 0, 0); | |
bed1ffca FW |
284 | if (!event) |
285 | return; | |
286 | ||
287 | entry = ring_buffer_event_data(event); | |
288 | entry->nr = syscall_nr; | |
289 | syscall_get_arguments(current, regs, 0, sys_data->nb_args, entry->args); | |
290 | ||
e77405ad SR |
291 | if (!filter_current_check_discard(buffer, sys_data->enter_event, |
292 | entry, event)) | |
293 | trace_current_buffer_unlock_commit(buffer, event, 0, 0); | |
ee08c6ec FW |
294 | } |
295 | ||
38516ab5 | 296 | void ftrace_syscall_exit(void *ignore, struct pt_regs *regs, long ret) |
ee08c6ec | 297 | { |
bed1ffca FW |
298 | struct syscall_trace_exit *entry; |
299 | struct syscall_metadata *sys_data; | |
300 | struct ring_buffer_event *event; | |
e77405ad | 301 | struct ring_buffer *buffer; |
ee08c6ec FW |
302 | int syscall_nr; |
303 | ||
304 | syscall_nr = syscall_get_nr(current, regs); | |
cd0980fc HB |
305 | if (syscall_nr < 0) |
306 | return; | |
fb34a08c JB |
307 | if (!test_bit(syscall_nr, enabled_exit_syscalls)) |
308 | return; | |
ee08c6ec | 309 | |
bed1ffca FW |
310 | sys_data = syscall_nr_to_meta(syscall_nr); |
311 | if (!sys_data) | |
312 | return; | |
313 | ||
fcc19438 LJ |
314 | event = trace_current_buffer_lock_reserve(&buffer, |
315 | sys_data->exit_event->id, sizeof(*entry), 0, 0); | |
bed1ffca FW |
316 | if (!event) |
317 | return; | |
318 | ||
319 | entry = ring_buffer_event_data(event); | |
320 | entry->nr = syscall_nr; | |
321 | entry->ret = syscall_get_return_value(current, regs); | |
322 | ||
e77405ad SR |
323 | if (!filter_current_check_discard(buffer, sys_data->exit_event, |
324 | entry, event)) | |
325 | trace_current_buffer_unlock_commit(buffer, event, 0, 0); | |
ee08c6ec FW |
326 | } |
327 | ||
bd1a5c84 | 328 | int reg_event_syscall_enter(struct ftrace_event_call *call) |
ee08c6ec | 329 | { |
fb34a08c JB |
330 | int ret = 0; |
331 | int num; | |
fb34a08c | 332 | |
c252f657 | 333 | num = ((struct syscall_metadata *)call->data)->syscall_nr; |
57421dbb | 334 | if (num < 0 || num >= NR_syscalls) |
fb34a08c JB |
335 | return -ENOSYS; |
336 | mutex_lock(&syscall_trace_lock); | |
337 | if (!sys_refcount_enter) | |
38516ab5 | 338 | ret = register_trace_sys_enter(ftrace_syscall_enter, NULL); |
3b8e4273 | 339 | if (!ret) { |
fb34a08c JB |
340 | set_bit(num, enabled_enter_syscalls); |
341 | sys_refcount_enter++; | |
342 | } | |
343 | mutex_unlock(&syscall_trace_lock); | |
344 | return ret; | |
ee08c6ec FW |
345 | } |
346 | ||
bd1a5c84 | 347 | void unreg_event_syscall_enter(struct ftrace_event_call *call) |
ee08c6ec | 348 | { |
fb34a08c | 349 | int num; |
ee08c6ec | 350 | |
c252f657 | 351 | num = ((struct syscall_metadata *)call->data)->syscall_nr; |
57421dbb | 352 | if (num < 0 || num >= NR_syscalls) |
fb34a08c JB |
353 | return; |
354 | mutex_lock(&syscall_trace_lock); | |
355 | sys_refcount_enter--; | |
356 | clear_bit(num, enabled_enter_syscalls); | |
357 | if (!sys_refcount_enter) | |
38516ab5 | 358 | unregister_trace_sys_enter(ftrace_syscall_enter, NULL); |
fb34a08c JB |
359 | mutex_unlock(&syscall_trace_lock); |
360 | } | |
ee08c6ec | 361 | |
bd1a5c84 | 362 | int reg_event_syscall_exit(struct ftrace_event_call *call) |
ee08c6ec | 363 | { |
fb34a08c JB |
364 | int ret = 0; |
365 | int num; | |
fb34a08c | 366 | |
c252f657 | 367 | num = ((struct syscall_metadata *)call->data)->syscall_nr; |
57421dbb | 368 | if (num < 0 || num >= NR_syscalls) |
fb34a08c JB |
369 | return -ENOSYS; |
370 | mutex_lock(&syscall_trace_lock); | |
371 | if (!sys_refcount_exit) | |
38516ab5 | 372 | ret = register_trace_sys_exit(ftrace_syscall_exit, NULL); |
3b8e4273 | 373 | if (!ret) { |
fb34a08c JB |
374 | set_bit(num, enabled_exit_syscalls); |
375 | sys_refcount_exit++; | |
ee08c6ec | 376 | } |
fb34a08c JB |
377 | mutex_unlock(&syscall_trace_lock); |
378 | return ret; | |
379 | } | |
ee08c6ec | 380 | |
bd1a5c84 | 381 | void unreg_event_syscall_exit(struct ftrace_event_call *call) |
fb34a08c JB |
382 | { |
383 | int num; | |
ee08c6ec | 384 | |
c252f657 | 385 | num = ((struct syscall_metadata *)call->data)->syscall_nr; |
57421dbb | 386 | if (num < 0 || num >= NR_syscalls) |
fb34a08c JB |
387 | return; |
388 | mutex_lock(&syscall_trace_lock); | |
389 | sys_refcount_exit--; | |
390 | clear_bit(num, enabled_exit_syscalls); | |
391 | if (!sys_refcount_exit) | |
38516ab5 | 392 | unregister_trace_sys_exit(ftrace_syscall_exit, NULL); |
fb34a08c | 393 | mutex_unlock(&syscall_trace_lock); |
ee08c6ec | 394 | } |
fb34a08c | 395 | |
a1301da0 LJ |
396 | int init_syscall_trace(struct ftrace_event_call *call) |
397 | { | |
398 | int id; | |
399 | ||
50307a45 LJ |
400 | if (set_syscall_print_fmt(call) < 0) |
401 | return -ENOMEM; | |
402 | ||
c7ef3a90 SR |
403 | id = trace_event_raw_init(call); |
404 | ||
405 | if (id < 0) { | |
50307a45 | 406 | free_syscall_print_fmt(call); |
c7ef3a90 | 407 | return id; |
50307a45 | 408 | } |
c7ef3a90 SR |
409 | |
410 | return id; | |
a1301da0 LJ |
411 | } |
412 | ||
e7b8e675 MF |
413 | unsigned long __init arch_syscall_addr(int nr) |
414 | { | |
415 | return (unsigned long)sys_call_table[nr]; | |
416 | } | |
417 | ||
c44fc770 FW |
418 | int __init init_ftrace_syscalls(void) |
419 | { | |
420 | struct syscall_metadata *meta; | |
421 | unsigned long addr; | |
422 | int i; | |
423 | ||
424 | syscalls_metadata = kzalloc(sizeof(*syscalls_metadata) * | |
425 | NR_syscalls, GFP_KERNEL); | |
426 | if (!syscalls_metadata) { | |
427 | WARN_ON(1); | |
428 | return -ENOMEM; | |
429 | } | |
430 | ||
431 | for (i = 0; i < NR_syscalls; i++) { | |
432 | addr = arch_syscall_addr(i); | |
433 | meta = find_syscall_meta(addr); | |
c252f657 LJ |
434 | if (!meta) |
435 | continue; | |
436 | ||
437 | meta->syscall_nr = i; | |
c44fc770 FW |
438 | syscalls_metadata[i] = meta; |
439 | } | |
440 | ||
441 | return 0; | |
442 | } | |
443 | core_initcall(init_ftrace_syscalls); | |
444 | ||
07b139c8 | 445 | #ifdef CONFIG_PERF_EVENTS |
19007a67 | 446 | |
97d5a220 FW |
447 | static DECLARE_BITMAP(enabled_perf_enter_syscalls, NR_syscalls); |
448 | static DECLARE_BITMAP(enabled_perf_exit_syscalls, NR_syscalls); | |
449 | static int sys_perf_refcount_enter; | |
450 | static int sys_perf_refcount_exit; | |
f4b5ffcc | 451 | |
38516ab5 | 452 | static void perf_syscall_enter(void *ignore, struct pt_regs *regs, long id) |
f4b5ffcc JB |
453 | { |
454 | struct syscall_metadata *sys_data; | |
20ab4425 FW |
455 | struct syscall_trace_enter *rec; |
456 | unsigned long flags; | |
f4b5ffcc | 457 | int syscall_nr; |
4ed7c92d | 458 | int rctx; |
19007a67 | 459 | int size; |
f4b5ffcc JB |
460 | |
461 | syscall_nr = syscall_get_nr(current, regs); | |
97d5a220 | 462 | if (!test_bit(syscall_nr, enabled_perf_enter_syscalls)) |
f4b5ffcc JB |
463 | return; |
464 | ||
465 | sys_data = syscall_nr_to_meta(syscall_nr); | |
466 | if (!sys_data) | |
467 | return; | |
468 | ||
19007a67 FW |
469 | /* get the size after alignment with the u32 buffer size field */ |
470 | size = sizeof(unsigned long) * sys_data->nb_args + sizeof(*rec); | |
471 | size = ALIGN(size + sizeof(u32), sizeof(u64)); | |
472 | size -= sizeof(u32); | |
473 | ||
97d5a220 FW |
474 | if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, |
475 | "perf buffer not large enough")) | |
20ab4425 FW |
476 | return; |
477 | ||
97d5a220 | 478 | rec = (struct syscall_trace_enter *)perf_trace_buf_prepare(size, |
430ad5a6 XG |
479 | sys_data->enter_event->id, &rctx, &flags); |
480 | if (!rec) | |
481 | return; | |
20ab4425 | 482 | |
20ab4425 FW |
483 | rec->nr = syscall_nr; |
484 | syscall_get_arguments(current, regs, 0, sys_data->nb_args, | |
485 | (unsigned long *)&rec->args); | |
97d5a220 | 486 | perf_trace_buf_submit(rec, size, rctx, 0, 1, flags, regs); |
f4b5ffcc JB |
487 | } |
488 | ||
97d5a220 | 489 | int perf_sysenter_enable(struct ftrace_event_call *call) |
f4b5ffcc JB |
490 | { |
491 | int ret = 0; | |
492 | int num; | |
493 | ||
3bbe84e9 | 494 | num = ((struct syscall_metadata *)call->data)->syscall_nr; |
f4b5ffcc JB |
495 | |
496 | mutex_lock(&syscall_trace_lock); | |
97d5a220 | 497 | if (!sys_perf_refcount_enter) |
38516ab5 | 498 | ret = register_trace_sys_enter(perf_syscall_enter, NULL); |
f4b5ffcc JB |
499 | if (ret) { |
500 | pr_info("event trace: Could not activate" | |
501 | "syscall entry trace point"); | |
502 | } else { | |
97d5a220 FW |
503 | set_bit(num, enabled_perf_enter_syscalls); |
504 | sys_perf_refcount_enter++; | |
f4b5ffcc JB |
505 | } |
506 | mutex_unlock(&syscall_trace_lock); | |
507 | return ret; | |
508 | } | |
509 | ||
97d5a220 | 510 | void perf_sysenter_disable(struct ftrace_event_call *call) |
f4b5ffcc JB |
511 | { |
512 | int num; | |
513 | ||
3bbe84e9 | 514 | num = ((struct syscall_metadata *)call->data)->syscall_nr; |
f4b5ffcc JB |
515 | |
516 | mutex_lock(&syscall_trace_lock); | |
97d5a220 FW |
517 | sys_perf_refcount_enter--; |
518 | clear_bit(num, enabled_perf_enter_syscalls); | |
519 | if (!sys_perf_refcount_enter) | |
38516ab5 | 520 | unregister_trace_sys_enter(perf_syscall_enter, NULL); |
f4b5ffcc JB |
521 | mutex_unlock(&syscall_trace_lock); |
522 | } | |
523 | ||
38516ab5 | 524 | static void perf_syscall_exit(void *ignore, struct pt_regs *regs, long ret) |
f4b5ffcc JB |
525 | { |
526 | struct syscall_metadata *sys_data; | |
20ab4425 FW |
527 | struct syscall_trace_exit *rec; |
528 | unsigned long flags; | |
f4b5ffcc | 529 | int syscall_nr; |
4ed7c92d | 530 | int rctx; |
20ab4425 | 531 | int size; |
f4b5ffcc JB |
532 | |
533 | syscall_nr = syscall_get_nr(current, regs); | |
97d5a220 | 534 | if (!test_bit(syscall_nr, enabled_perf_exit_syscalls)) |
f4b5ffcc JB |
535 | return; |
536 | ||
537 | sys_data = syscall_nr_to_meta(syscall_nr); | |
538 | if (!sys_data) | |
539 | return; | |
540 | ||
20ab4425 FW |
541 | /* We can probably do that at build time */ |
542 | size = ALIGN(sizeof(*rec) + sizeof(u32), sizeof(u64)); | |
543 | size -= sizeof(u32); | |
19007a67 | 544 | |
20ab4425 FW |
545 | /* |
546 | * Impossible, but be paranoid with the future | |
547 | * How to put this check outside runtime? | |
548 | */ | |
97d5a220 FW |
549 | if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, |
550 | "exit event has grown above perf buffer size")) | |
20ab4425 FW |
551 | return; |
552 | ||
97d5a220 | 553 | rec = (struct syscall_trace_exit *)perf_trace_buf_prepare(size, |
430ad5a6 XG |
554 | sys_data->exit_event->id, &rctx, &flags); |
555 | if (!rec) | |
556 | return; | |
20ab4425 | 557 | |
20ab4425 FW |
558 | rec->nr = syscall_nr; |
559 | rec->ret = syscall_get_return_value(current, regs); | |
560 | ||
97d5a220 | 561 | perf_trace_buf_submit(rec, size, rctx, 0, 1, flags, regs); |
f4b5ffcc JB |
562 | } |
563 | ||
97d5a220 | 564 | int perf_sysexit_enable(struct ftrace_event_call *call) |
f4b5ffcc JB |
565 | { |
566 | int ret = 0; | |
567 | int num; | |
568 | ||
3bbe84e9 | 569 | num = ((struct syscall_metadata *)call->data)->syscall_nr; |
f4b5ffcc JB |
570 | |
571 | mutex_lock(&syscall_trace_lock); | |
97d5a220 | 572 | if (!sys_perf_refcount_exit) |
38516ab5 | 573 | ret = register_trace_sys_exit(perf_syscall_exit, NULL); |
f4b5ffcc JB |
574 | if (ret) { |
575 | pr_info("event trace: Could not activate" | |
6574658b | 576 | "syscall exit trace point"); |
f4b5ffcc | 577 | } else { |
97d5a220 FW |
578 | set_bit(num, enabled_perf_exit_syscalls); |
579 | sys_perf_refcount_exit++; | |
f4b5ffcc JB |
580 | } |
581 | mutex_unlock(&syscall_trace_lock); | |
582 | return ret; | |
583 | } | |
584 | ||
97d5a220 | 585 | void perf_sysexit_disable(struct ftrace_event_call *call) |
f4b5ffcc JB |
586 | { |
587 | int num; | |
588 | ||
3bbe84e9 | 589 | num = ((struct syscall_metadata *)call->data)->syscall_nr; |
f4b5ffcc JB |
590 | |
591 | mutex_lock(&syscall_trace_lock); | |
97d5a220 FW |
592 | sys_perf_refcount_exit--; |
593 | clear_bit(num, enabled_perf_exit_syscalls); | |
594 | if (!sys_perf_refcount_exit) | |
38516ab5 | 595 | unregister_trace_sys_exit(perf_syscall_exit, NULL); |
f4b5ffcc JB |
596 | mutex_unlock(&syscall_trace_lock); |
597 | } | |
598 | ||
07b139c8 | 599 | #endif /* CONFIG_PERF_EVENTS */ |
f4b5ffcc | 600 | |
2239291a SR |
601 | static int syscall_enter_register(struct ftrace_event_call *event, |
602 | enum trace_reg type) | |
603 | { | |
604 | switch (type) { | |
605 | case TRACE_REG_REGISTER: | |
606 | return reg_event_syscall_enter(event); | |
607 | case TRACE_REG_UNREGISTER: | |
608 | unreg_event_syscall_enter(event); | |
609 | return 0; | |
610 | ||
611 | #ifdef CONFIG_PERF_EVENTS | |
612 | case TRACE_REG_PERF_REGISTER: | |
613 | return perf_sysenter_enable(event); | |
614 | case TRACE_REG_PERF_UNREGISTER: | |
615 | perf_sysenter_disable(event); | |
616 | return 0; | |
617 | #endif | |
618 | } | |
619 | return 0; | |
620 | } | |
621 | ||
622 | static int syscall_exit_register(struct ftrace_event_call *event, | |
623 | enum trace_reg type) | |
624 | { | |
625 | switch (type) { | |
626 | case TRACE_REG_REGISTER: | |
627 | return reg_event_syscall_exit(event); | |
628 | case TRACE_REG_UNREGISTER: | |
629 | unreg_event_syscall_exit(event); | |
630 | return 0; | |
631 | ||
632 | #ifdef CONFIG_PERF_EVENTS | |
633 | case TRACE_REG_PERF_REGISTER: | |
634 | return perf_sysexit_enable(event); | |
635 | case TRACE_REG_PERF_UNREGISTER: | |
636 | perf_sysexit_disable(event); | |
637 | return 0; | |
638 | #endif | |
639 | } | |
640 | return 0; | |
641 | } |