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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 | |
8f082018 SR |
18 | struct ftrace_event_class event_class_syscalls = { |
19 | .system = "syscalls" | |
20 | }; | |
21 | ||
c44fc770 FW |
22 | extern unsigned long __start_syscalls_metadata[]; |
23 | extern unsigned long __stop_syscalls_metadata[]; | |
24 | ||
25 | static struct syscall_metadata **syscalls_metadata; | |
26 | ||
27 | static struct syscall_metadata *find_syscall_meta(unsigned long syscall) | |
28 | { | |
29 | struct syscall_metadata *start; | |
30 | struct syscall_metadata *stop; | |
31 | char str[KSYM_SYMBOL_LEN]; | |
32 | ||
33 | ||
34 | start = (struct syscall_metadata *)__start_syscalls_metadata; | |
35 | stop = (struct syscall_metadata *)__stop_syscalls_metadata; | |
36 | kallsyms_lookup(syscall, NULL, NULL, NULL, str); | |
37 | ||
38 | for ( ; start < stop; start++) { | |
39 | /* | |
40 | * Only compare after the "sys" prefix. Archs that use | |
41 | * syscall wrappers may have syscalls symbols aliases prefixed | |
42 | * with "SyS" instead of "sys", leading to an unwanted | |
43 | * mismatch. | |
44 | */ | |
45 | if (start->name && !strcmp(start->name + 3, str + 3)) | |
46 | return start; | |
47 | } | |
48 | return NULL; | |
49 | } | |
50 | ||
51 | static struct syscall_metadata *syscall_nr_to_meta(int nr) | |
52 | { | |
53 | if (!syscalls_metadata || nr >= NR_syscalls || nr < 0) | |
54 | return NULL; | |
55 | ||
56 | return syscalls_metadata[nr]; | |
57 | } | |
58 | ||
bed1ffca FW |
59 | enum print_line_t |
60 | print_syscall_enter(struct trace_iterator *iter, int flags) | |
61 | { | |
62 | struct trace_seq *s = &iter->seq; | |
63 | struct trace_entry *ent = iter->ent; | |
64 | struct syscall_trace_enter *trace; | |
65 | struct syscall_metadata *entry; | |
66 | int i, ret, syscall; | |
67 | ||
64c12e04 | 68 | trace = (typeof(trace))ent; |
bed1ffca | 69 | syscall = trace->nr; |
bed1ffca | 70 | entry = syscall_nr_to_meta(syscall); |
64c12e04 | 71 | |
bed1ffca FW |
72 | if (!entry) |
73 | goto end; | |
74 | ||
fcc19438 | 75 | if (entry->enter_event->id != ent->type) { |
64c12e04 JB |
76 | WARN_ON_ONCE(1); |
77 | goto end; | |
78 | } | |
79 | ||
bed1ffca FW |
80 | ret = trace_seq_printf(s, "%s(", entry->name); |
81 | if (!ret) | |
82 | return TRACE_TYPE_PARTIAL_LINE; | |
83 | ||
84 | for (i = 0; i < entry->nb_args; i++) { | |
85 | /* parameter types */ | |
ba8b3a40 | 86 | if (trace_flags & TRACE_ITER_VERBOSE) { |
bed1ffca FW |
87 | ret = trace_seq_printf(s, "%s ", entry->types[i]); |
88 | if (!ret) | |
89 | return TRACE_TYPE_PARTIAL_LINE; | |
90 | } | |
91 | /* parameter values */ | |
4539f077 | 92 | ret = trace_seq_printf(s, "%s: %lx%s", entry->args[i], |
bed1ffca | 93 | trace->args[i], |
4539f077 | 94 | i == entry->nb_args - 1 ? "" : ", "); |
bed1ffca FW |
95 | if (!ret) |
96 | return TRACE_TYPE_PARTIAL_LINE; | |
97 | } | |
98 | ||
4539f077 LZ |
99 | ret = trace_seq_putc(s, ')'); |
100 | if (!ret) | |
101 | return TRACE_TYPE_PARTIAL_LINE; | |
102 | ||
bed1ffca | 103 | end: |
4539f077 LZ |
104 | ret = trace_seq_putc(s, '\n'); |
105 | if (!ret) | |
106 | return TRACE_TYPE_PARTIAL_LINE; | |
107 | ||
bed1ffca FW |
108 | return TRACE_TYPE_HANDLED; |
109 | } | |
110 | ||
111 | enum print_line_t | |
112 | print_syscall_exit(struct trace_iterator *iter, int flags) | |
113 | { | |
114 | struct trace_seq *s = &iter->seq; | |
115 | struct trace_entry *ent = iter->ent; | |
116 | struct syscall_trace_exit *trace; | |
117 | int syscall; | |
118 | struct syscall_metadata *entry; | |
119 | int ret; | |
120 | ||
64c12e04 | 121 | trace = (typeof(trace))ent; |
bed1ffca | 122 | syscall = trace->nr; |
bed1ffca | 123 | entry = syscall_nr_to_meta(syscall); |
64c12e04 | 124 | |
bed1ffca FW |
125 | if (!entry) { |
126 | trace_seq_printf(s, "\n"); | |
127 | return TRACE_TYPE_HANDLED; | |
128 | } | |
129 | ||
fcc19438 | 130 | if (entry->exit_event->id != ent->type) { |
64c12e04 JB |
131 | WARN_ON_ONCE(1); |
132 | return TRACE_TYPE_UNHANDLED; | |
133 | } | |
134 | ||
bed1ffca FW |
135 | ret = trace_seq_printf(s, "%s -> 0x%lx\n", entry->name, |
136 | trace->ret); | |
137 | if (!ret) | |
138 | return TRACE_TYPE_PARTIAL_LINE; | |
139 | ||
140 | return TRACE_TYPE_HANDLED; | |
141 | } | |
142 | ||
e6971969 LZ |
143 | extern char *__bad_type_size(void); |
144 | ||
145 | #define SYSCALL_FIELD(type, name) \ | |
146 | sizeof(type) != sizeof(trace.name) ? \ | |
147 | __bad_type_size() : \ | |
26a50744 TZ |
148 | #type, #name, offsetof(typeof(trace), name), \ |
149 | sizeof(trace.name), is_signed_type(type) | |
e6971969 | 150 | |
50307a45 LJ |
151 | static |
152 | int __set_enter_print_fmt(struct syscall_metadata *entry, char *buf, int len) | |
153 | { | |
154 | int i; | |
155 | int pos = 0; | |
156 | ||
157 | /* When len=0, we just calculate the needed length */ | |
158 | #define LEN_OR_ZERO (len ? len - pos : 0) | |
159 | ||
160 | pos += snprintf(buf + pos, LEN_OR_ZERO, "\""); | |
161 | for (i = 0; i < entry->nb_args; i++) { | |
162 | pos += snprintf(buf + pos, LEN_OR_ZERO, "%s: 0x%%0%zulx%s", | |
163 | entry->args[i], sizeof(unsigned long), | |
164 | i == entry->nb_args - 1 ? "" : ", "); | |
165 | } | |
166 | pos += snprintf(buf + pos, LEN_OR_ZERO, "\""); | |
167 | ||
168 | for (i = 0; i < entry->nb_args; i++) { | |
169 | pos += snprintf(buf + pos, LEN_OR_ZERO, | |
170 | ", ((unsigned long)(REC->%s))", entry->args[i]); | |
171 | } | |
172 | ||
173 | #undef LEN_OR_ZERO | |
174 | ||
175 | /* return the length of print_fmt */ | |
176 | return pos; | |
177 | } | |
178 | ||
179 | static int set_syscall_print_fmt(struct ftrace_event_call *call) | |
180 | { | |
181 | char *print_fmt; | |
182 | int len; | |
183 | struct syscall_metadata *entry = call->data; | |
184 | ||
185 | if (entry->enter_event != call) { | |
186 | call->print_fmt = "\"0x%lx\", REC->ret"; | |
187 | return 0; | |
188 | } | |
189 | ||
190 | /* First: called with 0 length to calculate the needed length */ | |
191 | len = __set_enter_print_fmt(entry, NULL, 0); | |
192 | ||
193 | print_fmt = kmalloc(len + 1, GFP_KERNEL); | |
194 | if (!print_fmt) | |
195 | return -ENOMEM; | |
196 | ||
197 | /* Second: actually write the @print_fmt */ | |
198 | __set_enter_print_fmt(entry, print_fmt, len + 1); | |
199 | call->print_fmt = print_fmt; | |
200 | ||
201 | return 0; | |
202 | } | |
203 | ||
204 | static void free_syscall_print_fmt(struct ftrace_event_call *call) | |
205 | { | |
206 | struct syscall_metadata *entry = call->data; | |
207 | ||
208 | if (entry->enter_event == call) | |
209 | kfree(call->print_fmt); | |
210 | } | |
211 | ||
540b7b8d LZ |
212 | int syscall_enter_define_fields(struct ftrace_event_call *call) |
213 | { | |
214 | struct syscall_trace_enter trace; | |
31c16b13 | 215 | struct syscall_metadata *meta = call->data; |
540b7b8d | 216 | int ret; |
540b7b8d LZ |
217 | int i; |
218 | int offset = offsetof(typeof(trace), args); | |
219 | ||
0f1ef51d LJ |
220 | ret = trace_define_field(call, SYSCALL_FIELD(int, nr), FILTER_OTHER); |
221 | if (ret) | |
222 | return ret; | |
223 | ||
540b7b8d | 224 | for (i = 0; i < meta->nb_args; i++) { |
aeaeae11 FW |
225 | ret = trace_define_field(call, meta->types[i], |
226 | meta->args[i], offset, | |
43b51ead LZ |
227 | sizeof(unsigned long), 0, |
228 | FILTER_OTHER); | |
540b7b8d LZ |
229 | offset += sizeof(unsigned long); |
230 | } | |
231 | ||
232 | return ret; | |
233 | } | |
234 | ||
235 | int syscall_exit_define_fields(struct ftrace_event_call *call) | |
236 | { | |
237 | struct syscall_trace_exit trace; | |
238 | int ret; | |
239 | ||
0f1ef51d LJ |
240 | ret = trace_define_field(call, SYSCALL_FIELD(int, nr), FILTER_OTHER); |
241 | if (ret) | |
242 | return ret; | |
243 | ||
26a50744 | 244 | ret = trace_define_field(call, SYSCALL_FIELD(long, ret), |
43b51ead | 245 | FILTER_OTHER); |
540b7b8d LZ |
246 | |
247 | return ret; | |
248 | } | |
249 | ||
fb34a08c | 250 | void ftrace_syscall_enter(struct pt_regs *regs, long id) |
ee08c6ec | 251 | { |
bed1ffca FW |
252 | struct syscall_trace_enter *entry; |
253 | struct syscall_metadata *sys_data; | |
254 | struct ring_buffer_event *event; | |
e77405ad | 255 | struct ring_buffer *buffer; |
bed1ffca | 256 | int size; |
ee08c6ec FW |
257 | int syscall_nr; |
258 | ||
259 | syscall_nr = syscall_get_nr(current, regs); | |
cd0980fc HB |
260 | if (syscall_nr < 0) |
261 | return; | |
fb34a08c JB |
262 | if (!test_bit(syscall_nr, enabled_enter_syscalls)) |
263 | return; | |
ee08c6ec | 264 | |
bed1ffca FW |
265 | sys_data = syscall_nr_to_meta(syscall_nr); |
266 | if (!sys_data) | |
267 | return; | |
268 | ||
269 | size = sizeof(*entry) + sizeof(unsigned long) * sys_data->nb_args; | |
270 | ||
fcc19438 LJ |
271 | event = trace_current_buffer_lock_reserve(&buffer, |
272 | sys_data->enter_event->id, size, 0, 0); | |
bed1ffca FW |
273 | if (!event) |
274 | return; | |
275 | ||
276 | entry = ring_buffer_event_data(event); | |
277 | entry->nr = syscall_nr; | |
278 | syscall_get_arguments(current, regs, 0, sys_data->nb_args, entry->args); | |
279 | ||
e77405ad SR |
280 | if (!filter_current_check_discard(buffer, sys_data->enter_event, |
281 | entry, event)) | |
282 | trace_current_buffer_unlock_commit(buffer, event, 0, 0); | |
ee08c6ec FW |
283 | } |
284 | ||
fb34a08c | 285 | void ftrace_syscall_exit(struct pt_regs *regs, long ret) |
ee08c6ec | 286 | { |
bed1ffca FW |
287 | struct syscall_trace_exit *entry; |
288 | struct syscall_metadata *sys_data; | |
289 | struct ring_buffer_event *event; | |
e77405ad | 290 | struct ring_buffer *buffer; |
ee08c6ec FW |
291 | int syscall_nr; |
292 | ||
293 | syscall_nr = syscall_get_nr(current, regs); | |
cd0980fc HB |
294 | if (syscall_nr < 0) |
295 | return; | |
fb34a08c JB |
296 | if (!test_bit(syscall_nr, enabled_exit_syscalls)) |
297 | return; | |
ee08c6ec | 298 | |
bed1ffca FW |
299 | sys_data = syscall_nr_to_meta(syscall_nr); |
300 | if (!sys_data) | |
301 | return; | |
302 | ||
fcc19438 LJ |
303 | event = trace_current_buffer_lock_reserve(&buffer, |
304 | sys_data->exit_event->id, sizeof(*entry), 0, 0); | |
bed1ffca FW |
305 | if (!event) |
306 | return; | |
307 | ||
308 | entry = ring_buffer_event_data(event); | |
309 | entry->nr = syscall_nr; | |
310 | entry->ret = syscall_get_return_value(current, regs); | |
311 | ||
e77405ad SR |
312 | if (!filter_current_check_discard(buffer, sys_data->exit_event, |
313 | entry, event)) | |
314 | trace_current_buffer_unlock_commit(buffer, event, 0, 0); | |
ee08c6ec FW |
315 | } |
316 | ||
bd1a5c84 | 317 | int reg_event_syscall_enter(struct ftrace_event_call *call) |
ee08c6ec | 318 | { |
fb34a08c JB |
319 | int ret = 0; |
320 | int num; | |
fb34a08c | 321 | |
c252f657 | 322 | num = ((struct syscall_metadata *)call->data)->syscall_nr; |
57421dbb | 323 | if (num < 0 || num >= NR_syscalls) |
fb34a08c JB |
324 | return -ENOSYS; |
325 | mutex_lock(&syscall_trace_lock); | |
326 | if (!sys_refcount_enter) | |
1c569f02 | 327 | ret = register_trace_sys_enter(ftrace_syscall_enter); |
3b8e4273 | 328 | if (!ret) { |
fb34a08c JB |
329 | set_bit(num, enabled_enter_syscalls); |
330 | sys_refcount_enter++; | |
331 | } | |
332 | mutex_unlock(&syscall_trace_lock); | |
333 | return ret; | |
ee08c6ec FW |
334 | } |
335 | ||
bd1a5c84 | 336 | void unreg_event_syscall_enter(struct ftrace_event_call *call) |
ee08c6ec | 337 | { |
fb34a08c | 338 | int num; |
ee08c6ec | 339 | |
c252f657 | 340 | num = ((struct syscall_metadata *)call->data)->syscall_nr; |
57421dbb | 341 | if (num < 0 || num >= NR_syscalls) |
fb34a08c JB |
342 | return; |
343 | mutex_lock(&syscall_trace_lock); | |
344 | sys_refcount_enter--; | |
345 | clear_bit(num, enabled_enter_syscalls); | |
346 | if (!sys_refcount_enter) | |
1c569f02 | 347 | unregister_trace_sys_enter(ftrace_syscall_enter); |
fb34a08c JB |
348 | mutex_unlock(&syscall_trace_lock); |
349 | } | |
ee08c6ec | 350 | |
bd1a5c84 | 351 | int reg_event_syscall_exit(struct ftrace_event_call *call) |
ee08c6ec | 352 | { |
fb34a08c JB |
353 | int ret = 0; |
354 | int num; | |
fb34a08c | 355 | |
c252f657 | 356 | num = ((struct syscall_metadata *)call->data)->syscall_nr; |
57421dbb | 357 | if (num < 0 || num >= NR_syscalls) |
fb34a08c JB |
358 | return -ENOSYS; |
359 | mutex_lock(&syscall_trace_lock); | |
360 | if (!sys_refcount_exit) | |
1c569f02 | 361 | ret = register_trace_sys_exit(ftrace_syscall_exit); |
3b8e4273 | 362 | if (!ret) { |
fb34a08c JB |
363 | set_bit(num, enabled_exit_syscalls); |
364 | sys_refcount_exit++; | |
ee08c6ec | 365 | } |
fb34a08c JB |
366 | mutex_unlock(&syscall_trace_lock); |
367 | return ret; | |
368 | } | |
ee08c6ec | 369 | |
bd1a5c84 | 370 | void unreg_event_syscall_exit(struct ftrace_event_call *call) |
fb34a08c JB |
371 | { |
372 | int num; | |
ee08c6ec | 373 | |
c252f657 | 374 | num = ((struct syscall_metadata *)call->data)->syscall_nr; |
57421dbb | 375 | if (num < 0 || num >= NR_syscalls) |
fb34a08c JB |
376 | return; |
377 | mutex_lock(&syscall_trace_lock); | |
378 | sys_refcount_exit--; | |
379 | clear_bit(num, enabled_exit_syscalls); | |
380 | if (!sys_refcount_exit) | |
1c569f02 | 381 | unregister_trace_sys_exit(ftrace_syscall_exit); |
fb34a08c | 382 | mutex_unlock(&syscall_trace_lock); |
ee08c6ec | 383 | } |
fb34a08c | 384 | |
a1301da0 LJ |
385 | int init_syscall_trace(struct ftrace_event_call *call) |
386 | { | |
387 | int id; | |
388 | ||
50307a45 LJ |
389 | if (set_syscall_print_fmt(call) < 0) |
390 | return -ENOMEM; | |
391 | ||
c7ef3a90 SR |
392 | id = trace_event_raw_init(call); |
393 | ||
394 | if (id < 0) { | |
50307a45 | 395 | free_syscall_print_fmt(call); |
c7ef3a90 | 396 | return id; |
50307a45 | 397 | } |
c7ef3a90 SR |
398 | |
399 | return id; | |
a1301da0 LJ |
400 | } |
401 | ||
e7b8e675 MF |
402 | unsigned long __init arch_syscall_addr(int nr) |
403 | { | |
404 | return (unsigned long)sys_call_table[nr]; | |
405 | } | |
406 | ||
c44fc770 FW |
407 | int __init init_ftrace_syscalls(void) |
408 | { | |
409 | struct syscall_metadata *meta; | |
410 | unsigned long addr; | |
411 | int i; | |
412 | ||
413 | syscalls_metadata = kzalloc(sizeof(*syscalls_metadata) * | |
414 | NR_syscalls, GFP_KERNEL); | |
415 | if (!syscalls_metadata) { | |
416 | WARN_ON(1); | |
417 | return -ENOMEM; | |
418 | } | |
419 | ||
420 | for (i = 0; i < NR_syscalls; i++) { | |
421 | addr = arch_syscall_addr(i); | |
422 | meta = find_syscall_meta(addr); | |
c252f657 LJ |
423 | if (!meta) |
424 | continue; | |
425 | ||
426 | meta->syscall_nr = i; | |
c44fc770 FW |
427 | syscalls_metadata[i] = meta; |
428 | } | |
429 | ||
430 | return 0; | |
431 | } | |
432 | core_initcall(init_ftrace_syscalls); | |
433 | ||
07b139c8 | 434 | #ifdef CONFIG_PERF_EVENTS |
19007a67 | 435 | |
97d5a220 FW |
436 | static DECLARE_BITMAP(enabled_perf_enter_syscalls, NR_syscalls); |
437 | static DECLARE_BITMAP(enabled_perf_exit_syscalls, NR_syscalls); | |
438 | static int sys_perf_refcount_enter; | |
439 | static int sys_perf_refcount_exit; | |
f4b5ffcc | 440 | |
97d5a220 | 441 | static void perf_syscall_enter(struct pt_regs *regs, long id) |
f4b5ffcc JB |
442 | { |
443 | struct syscall_metadata *sys_data; | |
20ab4425 FW |
444 | struct syscall_trace_enter *rec; |
445 | unsigned long flags; | |
f4b5ffcc | 446 | int syscall_nr; |
4ed7c92d | 447 | int rctx; |
19007a67 | 448 | int size; |
f4b5ffcc JB |
449 | |
450 | syscall_nr = syscall_get_nr(current, regs); | |
97d5a220 | 451 | if (!test_bit(syscall_nr, enabled_perf_enter_syscalls)) |
f4b5ffcc JB |
452 | return; |
453 | ||
454 | sys_data = syscall_nr_to_meta(syscall_nr); | |
455 | if (!sys_data) | |
456 | return; | |
457 | ||
19007a67 FW |
458 | /* get the size after alignment with the u32 buffer size field */ |
459 | size = sizeof(unsigned long) * sys_data->nb_args + sizeof(*rec); | |
460 | size = ALIGN(size + sizeof(u32), sizeof(u64)); | |
461 | size -= sizeof(u32); | |
462 | ||
97d5a220 FW |
463 | if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, |
464 | "perf buffer not large enough")) | |
20ab4425 FW |
465 | return; |
466 | ||
97d5a220 | 467 | rec = (struct syscall_trace_enter *)perf_trace_buf_prepare(size, |
430ad5a6 XG |
468 | sys_data->enter_event->id, &rctx, &flags); |
469 | if (!rec) | |
470 | return; | |
20ab4425 | 471 | |
20ab4425 FW |
472 | rec->nr = syscall_nr; |
473 | syscall_get_arguments(current, regs, 0, sys_data->nb_args, | |
474 | (unsigned long *)&rec->args); | |
97d5a220 | 475 | perf_trace_buf_submit(rec, size, rctx, 0, 1, flags, regs); |
f4b5ffcc JB |
476 | } |
477 | ||
97d5a220 | 478 | int perf_sysenter_enable(struct ftrace_event_call *call) |
f4b5ffcc JB |
479 | { |
480 | int ret = 0; | |
481 | int num; | |
482 | ||
3bbe84e9 | 483 | num = ((struct syscall_metadata *)call->data)->syscall_nr; |
f4b5ffcc JB |
484 | |
485 | mutex_lock(&syscall_trace_lock); | |
97d5a220 FW |
486 | if (!sys_perf_refcount_enter) |
487 | ret = register_trace_sys_enter(perf_syscall_enter); | |
f4b5ffcc JB |
488 | if (ret) { |
489 | pr_info("event trace: Could not activate" | |
490 | "syscall entry trace point"); | |
491 | } else { | |
97d5a220 FW |
492 | set_bit(num, enabled_perf_enter_syscalls); |
493 | sys_perf_refcount_enter++; | |
f4b5ffcc JB |
494 | } |
495 | mutex_unlock(&syscall_trace_lock); | |
496 | return ret; | |
497 | } | |
498 | ||
97d5a220 | 499 | void perf_sysenter_disable(struct ftrace_event_call *call) |
f4b5ffcc JB |
500 | { |
501 | int num; | |
502 | ||
3bbe84e9 | 503 | num = ((struct syscall_metadata *)call->data)->syscall_nr; |
f4b5ffcc JB |
504 | |
505 | mutex_lock(&syscall_trace_lock); | |
97d5a220 FW |
506 | sys_perf_refcount_enter--; |
507 | clear_bit(num, enabled_perf_enter_syscalls); | |
508 | if (!sys_perf_refcount_enter) | |
509 | unregister_trace_sys_enter(perf_syscall_enter); | |
f4b5ffcc JB |
510 | mutex_unlock(&syscall_trace_lock); |
511 | } | |
512 | ||
97d5a220 | 513 | static void perf_syscall_exit(struct pt_regs *regs, long ret) |
f4b5ffcc JB |
514 | { |
515 | struct syscall_metadata *sys_data; | |
20ab4425 FW |
516 | struct syscall_trace_exit *rec; |
517 | unsigned long flags; | |
f4b5ffcc | 518 | int syscall_nr; |
4ed7c92d | 519 | int rctx; |
20ab4425 | 520 | int size; |
f4b5ffcc JB |
521 | |
522 | syscall_nr = syscall_get_nr(current, regs); | |
97d5a220 | 523 | if (!test_bit(syscall_nr, enabled_perf_exit_syscalls)) |
f4b5ffcc JB |
524 | return; |
525 | ||
526 | sys_data = syscall_nr_to_meta(syscall_nr); | |
527 | if (!sys_data) | |
528 | return; | |
529 | ||
20ab4425 FW |
530 | /* We can probably do that at build time */ |
531 | size = ALIGN(sizeof(*rec) + sizeof(u32), sizeof(u64)); | |
532 | size -= sizeof(u32); | |
19007a67 | 533 | |
20ab4425 FW |
534 | /* |
535 | * Impossible, but be paranoid with the future | |
536 | * How to put this check outside runtime? | |
537 | */ | |
97d5a220 FW |
538 | if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, |
539 | "exit event has grown above perf buffer size")) | |
20ab4425 FW |
540 | return; |
541 | ||
97d5a220 | 542 | rec = (struct syscall_trace_exit *)perf_trace_buf_prepare(size, |
430ad5a6 XG |
543 | sys_data->exit_event->id, &rctx, &flags); |
544 | if (!rec) | |
545 | return; | |
20ab4425 | 546 | |
20ab4425 FW |
547 | rec->nr = syscall_nr; |
548 | rec->ret = syscall_get_return_value(current, regs); | |
549 | ||
97d5a220 | 550 | perf_trace_buf_submit(rec, size, rctx, 0, 1, flags, regs); |
f4b5ffcc JB |
551 | } |
552 | ||
97d5a220 | 553 | int perf_sysexit_enable(struct ftrace_event_call *call) |
f4b5ffcc JB |
554 | { |
555 | int ret = 0; | |
556 | int num; | |
557 | ||
3bbe84e9 | 558 | num = ((struct syscall_metadata *)call->data)->syscall_nr; |
f4b5ffcc JB |
559 | |
560 | mutex_lock(&syscall_trace_lock); | |
97d5a220 FW |
561 | if (!sys_perf_refcount_exit) |
562 | ret = register_trace_sys_exit(perf_syscall_exit); | |
f4b5ffcc JB |
563 | if (ret) { |
564 | pr_info("event trace: Could not activate" | |
6574658b | 565 | "syscall exit trace point"); |
f4b5ffcc | 566 | } else { |
97d5a220 FW |
567 | set_bit(num, enabled_perf_exit_syscalls); |
568 | sys_perf_refcount_exit++; | |
f4b5ffcc JB |
569 | } |
570 | mutex_unlock(&syscall_trace_lock); | |
571 | return ret; | |
572 | } | |
573 | ||
97d5a220 | 574 | void perf_sysexit_disable(struct ftrace_event_call *call) |
f4b5ffcc JB |
575 | { |
576 | int num; | |
577 | ||
3bbe84e9 | 578 | num = ((struct syscall_metadata *)call->data)->syscall_nr; |
f4b5ffcc JB |
579 | |
580 | mutex_lock(&syscall_trace_lock); | |
97d5a220 FW |
581 | sys_perf_refcount_exit--; |
582 | clear_bit(num, enabled_perf_exit_syscalls); | |
583 | if (!sys_perf_refcount_exit) | |
584 | unregister_trace_sys_exit(perf_syscall_exit); | |
f4b5ffcc JB |
585 | mutex_unlock(&syscall_trace_lock); |
586 | } | |
587 | ||
07b139c8 | 588 | #endif /* CONFIG_PERF_EVENTS */ |
f4b5ffcc | 589 |