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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
47788c58 | 2 | #include <trace/syscall.h> |
1c569f02 | 3 | #include <trace/events/syscalls.h> |
f431b634 | 4 | #include <linux/syscalls.h> |
5a0e3ad6 | 5 | #include <linux/slab.h> |
ee08c6ec | 6 | #include <linux/kernel.h> |
56d82e00 | 7 | #include <linux/module.h> /* for MODULE_NAME_LEN via KSYM_SYMBOL_LEN */ |
fb34a08c | 8 | #include <linux/ftrace.h> |
cdd6c482 | 9 | #include <linux/perf_event.h> |
ee08c6ec FW |
10 | #include <asm/syscall.h> |
11 | ||
12 | #include "trace_output.h" | |
13 | #include "trace.h" | |
14 | ||
5be71b61 | 15 | static DEFINE_MUTEX(syscall_trace_lock); |
ee08c6ec | 16 | |
2425bcb9 | 17 | static int syscall_enter_register(struct trace_event_call *event, |
ceec0b6f | 18 | enum trace_reg type, void *data); |
2425bcb9 | 19 | static int syscall_exit_register(struct trace_event_call *event, |
ceec0b6f | 20 | enum trace_reg type, void *data); |
2239291a | 21 | |
2e33af02 | 22 | static struct list_head * |
2425bcb9 | 23 | syscall_get_enter_fields(struct trace_event_call *call) |
2e33af02 SR |
24 | { |
25 | struct syscall_metadata *entry = call->data; | |
26 | ||
27 | return &entry->enter_fields; | |
28 | } | |
29 | ||
3d56e331 SR |
30 | extern struct syscall_metadata *__start_syscalls_metadata[]; |
31 | extern struct syscall_metadata *__stop_syscalls_metadata[]; | |
c44fc770 FW |
32 | |
33 | static struct syscall_metadata **syscalls_metadata; | |
34 | ||
b2d55496 IM |
35 | #ifndef ARCH_HAS_SYSCALL_MATCH_SYM_NAME |
36 | static inline bool arch_syscall_match_sym_name(const char *sym, const char *name) | |
37 | { | |
38 | /* | |
39 | * Only compare after the "sys" prefix. Archs that use | |
40 | * syscall wrappers may have syscalls symbols aliases prefixed | |
36a78e9e | 41 | * with ".SyS" or ".sys" instead of "sys", leading to an unwanted |
b2d55496 IM |
42 | * mismatch. |
43 | */ | |
44 | return !strcmp(sym + 3, name + 3); | |
45 | } | |
46 | #endif | |
47 | ||
f431b634 SR |
48 | #ifdef ARCH_TRACE_IGNORE_COMPAT_SYSCALLS |
49 | /* | |
50 | * Some architectures that allow for 32bit applications | |
51 | * to run on a 64bit kernel, do not map the syscalls for | |
52 | * the 32bit tasks the same as they do for 64bit tasks. | |
53 | * | |
54 | * *cough*x86*cough* | |
55 | * | |
56 | * In such a case, instead of reporting the wrong syscalls, | |
57 | * simply ignore them. | |
58 | * | |
59 | * For an arch to ignore the compat syscalls it needs to | |
60 | * define ARCH_TRACE_IGNORE_COMPAT_SYSCALLS as well as | |
61 | * define the function arch_trace_is_compat_syscall() to let | |
62 | * the tracing system know that it should ignore it. | |
63 | */ | |
64 | static int | |
65 | trace_get_syscall_nr(struct task_struct *task, struct pt_regs *regs) | |
66 | { | |
67 | if (unlikely(arch_trace_is_compat_syscall(regs))) | |
68 | return -1; | |
69 | ||
70 | return syscall_get_nr(task, regs); | |
71 | } | |
72 | #else | |
73 | static inline int | |
74 | trace_get_syscall_nr(struct task_struct *task, struct pt_regs *regs) | |
75 | { | |
76 | return syscall_get_nr(task, regs); | |
77 | } | |
78 | #endif /* ARCH_TRACE_IGNORE_COMPAT_SYSCALLS */ | |
79 | ||
3d56e331 SR |
80 | static __init struct syscall_metadata * |
81 | find_syscall_meta(unsigned long syscall) | |
c44fc770 | 82 | { |
3d56e331 SR |
83 | struct syscall_metadata **start; |
84 | struct syscall_metadata **stop; | |
c44fc770 FW |
85 | char str[KSYM_SYMBOL_LEN]; |
86 | ||
87 | ||
3d56e331 SR |
88 | start = __start_syscalls_metadata; |
89 | stop = __stop_syscalls_metadata; | |
c44fc770 FW |
90 | kallsyms_lookup(syscall, NULL, NULL, NULL, str); |
91 | ||
ae07f551 IM |
92 | if (arch_syscall_match_sym_name(str, "sys_ni_syscall")) |
93 | return NULL; | |
94 | ||
c44fc770 | 95 | for ( ; start < stop; start++) { |
b2d55496 | 96 | if ((*start)->name && arch_syscall_match_sym_name(str, (*start)->name)) |
3d56e331 | 97 | return *start; |
c44fc770 FW |
98 | } |
99 | return NULL; | |
100 | } | |
101 | ||
102 | static struct syscall_metadata *syscall_nr_to_meta(int nr) | |
103 | { | |
104 | if (!syscalls_metadata || nr >= NR_syscalls || nr < 0) | |
105 | return NULL; | |
106 | ||
107 | return syscalls_metadata[nr]; | |
108 | } | |
109 | ||
dbfeaa7a TZ |
110 | const char *get_syscall_name(int syscall) |
111 | { | |
112 | struct syscall_metadata *entry; | |
113 | ||
114 | entry = syscall_nr_to_meta(syscall); | |
115 | if (!entry) | |
116 | return NULL; | |
117 | ||
118 | return entry->name; | |
119 | } | |
120 | ||
6aea49cb | 121 | static enum print_line_t |
a9a57763 SR |
122 | print_syscall_enter(struct trace_iterator *iter, int flags, |
123 | struct trace_event *event) | |
bed1ffca | 124 | { |
983f938a | 125 | struct trace_array *tr = iter->tr; |
bed1ffca FW |
126 | struct trace_seq *s = &iter->seq; |
127 | struct trace_entry *ent = iter->ent; | |
128 | struct syscall_trace_enter *trace; | |
129 | struct syscall_metadata *entry; | |
183742f0 | 130 | int i, syscall; |
bed1ffca | 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 | goto end; | |
138 | ||
32c0edae | 139 | if (entry->enter_event->event.type != ent->type) { |
64c12e04 JB |
140 | WARN_ON_ONCE(1); |
141 | goto end; | |
142 | } | |
143 | ||
183742f0 | 144 | trace_seq_printf(s, "%s(", entry->name); |
bed1ffca FW |
145 | |
146 | for (i = 0; i < entry->nb_args; i++) { | |
183742f0 SRRH |
147 | |
148 | if (trace_seq_has_overflowed(s)) | |
149 | goto end; | |
150 | ||
bed1ffca | 151 | /* parameter types */ |
983f938a | 152 | if (tr->trace_flags & TRACE_ITER_VERBOSE) |
183742f0 SRRH |
153 | trace_seq_printf(s, "%s ", entry->types[i]); |
154 | ||
bed1ffca | 155 | /* parameter values */ |
183742f0 SRRH |
156 | trace_seq_printf(s, "%s: %lx%s", entry->args[i], |
157 | trace->args[i], | |
158 | i == entry->nb_args - 1 ? "" : ", "); | |
bed1ffca FW |
159 | } |
160 | ||
183742f0 | 161 | trace_seq_putc(s, ')'); |
bed1ffca | 162 | end: |
183742f0 | 163 | trace_seq_putc(s, '\n'); |
4539f077 | 164 | |
183742f0 | 165 | return trace_handle_return(s); |
bed1ffca FW |
166 | } |
167 | ||
6aea49cb | 168 | static enum print_line_t |
a9a57763 SR |
169 | print_syscall_exit(struct trace_iterator *iter, int flags, |
170 | struct trace_event *event) | |
bed1ffca FW |
171 | { |
172 | struct trace_seq *s = &iter->seq; | |
173 | struct trace_entry *ent = iter->ent; | |
174 | struct syscall_trace_exit *trace; | |
175 | int syscall; | |
176 | struct syscall_metadata *entry; | |
bed1ffca | 177 | |
64c12e04 | 178 | trace = (typeof(trace))ent; |
bed1ffca | 179 | syscall = trace->nr; |
bed1ffca | 180 | entry = syscall_nr_to_meta(syscall); |
64c12e04 | 181 | |
bed1ffca | 182 | if (!entry) { |
146c3442 | 183 | trace_seq_putc(s, '\n'); |
183742f0 | 184 | goto out; |
bed1ffca FW |
185 | } |
186 | ||
32c0edae | 187 | if (entry->exit_event->event.type != ent->type) { |
64c12e04 JB |
188 | WARN_ON_ONCE(1); |
189 | return TRACE_TYPE_UNHANDLED; | |
190 | } | |
191 | ||
183742f0 | 192 | trace_seq_printf(s, "%s -> 0x%lx\n", entry->name, |
bed1ffca | 193 | trace->ret); |
bed1ffca | 194 | |
183742f0 SRRH |
195 | out: |
196 | return trace_handle_return(s); | |
bed1ffca FW |
197 | } |
198 | ||
e6971969 LZ |
199 | extern char *__bad_type_size(void); |
200 | ||
026842d1 TS |
201 | #define SYSCALL_FIELD(type, field, name) \ |
202 | sizeof(type) != sizeof(trace.field) ? \ | |
e6971969 | 203 | __bad_type_size() : \ |
026842d1 TS |
204 | #type, #name, offsetof(typeof(trace), field), \ |
205 | sizeof(trace.field), is_signed_type(type) | |
e6971969 | 206 | |
3ddc77f6 LZ |
207 | static int __init |
208 | __set_enter_print_fmt(struct syscall_metadata *entry, char *buf, int len) | |
50307a45 LJ |
209 | { |
210 | int i; | |
211 | int pos = 0; | |
212 | ||
213 | /* When len=0, we just calculate the needed length */ | |
214 | #define LEN_OR_ZERO (len ? len - pos : 0) | |
215 | ||
216 | pos += snprintf(buf + pos, LEN_OR_ZERO, "\""); | |
217 | for (i = 0; i < entry->nb_args; i++) { | |
218 | pos += snprintf(buf + pos, LEN_OR_ZERO, "%s: 0x%%0%zulx%s", | |
219 | entry->args[i], sizeof(unsigned long), | |
220 | i == entry->nb_args - 1 ? "" : ", "); | |
221 | } | |
222 | pos += snprintf(buf + pos, LEN_OR_ZERO, "\""); | |
223 | ||
224 | for (i = 0; i < entry->nb_args; i++) { | |
225 | pos += snprintf(buf + pos, LEN_OR_ZERO, | |
226 | ", ((unsigned long)(REC->%s))", entry->args[i]); | |
227 | } | |
228 | ||
229 | #undef LEN_OR_ZERO | |
230 | ||
231 | /* return the length of print_fmt */ | |
232 | return pos; | |
233 | } | |
234 | ||
2425bcb9 | 235 | static int __init set_syscall_print_fmt(struct trace_event_call *call) |
50307a45 LJ |
236 | { |
237 | char *print_fmt; | |
238 | int len; | |
239 | struct syscall_metadata *entry = call->data; | |
240 | ||
241 | if (entry->enter_event != call) { | |
242 | call->print_fmt = "\"0x%lx\", REC->ret"; | |
243 | return 0; | |
244 | } | |
245 | ||
246 | /* First: called with 0 length to calculate the needed length */ | |
247 | len = __set_enter_print_fmt(entry, NULL, 0); | |
248 | ||
249 | print_fmt = kmalloc(len + 1, GFP_KERNEL); | |
250 | if (!print_fmt) | |
251 | return -ENOMEM; | |
252 | ||
253 | /* Second: actually write the @print_fmt */ | |
254 | __set_enter_print_fmt(entry, print_fmt, len + 1); | |
255 | call->print_fmt = print_fmt; | |
256 | ||
257 | return 0; | |
258 | } | |
259 | ||
2425bcb9 | 260 | static void __init free_syscall_print_fmt(struct trace_event_call *call) |
50307a45 LJ |
261 | { |
262 | struct syscall_metadata *entry = call->data; | |
263 | ||
264 | if (entry->enter_event == call) | |
265 | kfree(call->print_fmt); | |
266 | } | |
267 | ||
2425bcb9 | 268 | static int __init syscall_enter_define_fields(struct trace_event_call *call) |
540b7b8d LZ |
269 | { |
270 | struct syscall_trace_enter trace; | |
31c16b13 | 271 | struct syscall_metadata *meta = call->data; |
540b7b8d | 272 | int ret; |
540b7b8d LZ |
273 | int i; |
274 | int offset = offsetof(typeof(trace), args); | |
275 | ||
026842d1 TS |
276 | ret = trace_define_field(call, SYSCALL_FIELD(int, nr, __syscall_nr), |
277 | FILTER_OTHER); | |
0f1ef51d LJ |
278 | if (ret) |
279 | return ret; | |
280 | ||
540b7b8d | 281 | for (i = 0; i < meta->nb_args; i++) { |
aeaeae11 FW |
282 | ret = trace_define_field(call, meta->types[i], |
283 | meta->args[i], offset, | |
43b51ead LZ |
284 | sizeof(unsigned long), 0, |
285 | FILTER_OTHER); | |
540b7b8d LZ |
286 | offset += sizeof(unsigned long); |
287 | } | |
288 | ||
289 | return ret; | |
290 | } | |
291 | ||
2425bcb9 | 292 | static int __init syscall_exit_define_fields(struct trace_event_call *call) |
540b7b8d LZ |
293 | { |
294 | struct syscall_trace_exit trace; | |
295 | int ret; | |
296 | ||
026842d1 TS |
297 | ret = trace_define_field(call, SYSCALL_FIELD(int, nr, __syscall_nr), |
298 | FILTER_OTHER); | |
0f1ef51d LJ |
299 | if (ret) |
300 | return ret; | |
301 | ||
026842d1 | 302 | ret = trace_define_field(call, SYSCALL_FIELD(long, ret, ret), |
43b51ead | 303 | FILTER_OTHER); |
540b7b8d LZ |
304 | |
305 | return ret; | |
306 | } | |
307 | ||
12ab74ee | 308 | static void ftrace_syscall_enter(void *data, struct pt_regs *regs, long id) |
ee08c6ec | 309 | { |
12ab74ee | 310 | struct trace_array *tr = data; |
7f1d2f82 | 311 | struct trace_event_file *trace_file; |
bed1ffca FW |
312 | struct syscall_trace_enter *entry; |
313 | struct syscall_metadata *sys_data; | |
314 | struct ring_buffer_event *event; | |
e77405ad | 315 | struct ring_buffer *buffer; |
11034ae9 J |
316 | unsigned long irq_flags; |
317 | int pc; | |
ee08c6ec | 318 | int syscall_nr; |
f431b634 | 319 | int size; |
ee08c6ec | 320 | |
f431b634 | 321 | syscall_nr = trace_get_syscall_nr(current, regs); |
086ba77a | 322 | if (syscall_nr < 0 || syscall_nr >= NR_syscalls) |
cd0980fc | 323 | return; |
d562aff9 TZ |
324 | |
325 | /* Here we're inside tp handler's rcu_read_lock_sched (__DO_TRACE) */ | |
7f1d2f82 SRRH |
326 | trace_file = rcu_dereference_sched(tr->enter_syscall_files[syscall_nr]); |
327 | if (!trace_file) | |
d562aff9 TZ |
328 | return; |
329 | ||
09a5059a | 330 | if (trace_trigger_soft_disabled(trace_file)) |
13a1e4ae | 331 | return; |
ee08c6ec | 332 | |
bed1ffca FW |
333 | sys_data = syscall_nr_to_meta(syscall_nr); |
334 | if (!sys_data) | |
335 | return; | |
336 | ||
337 | size = sizeof(*entry) + sizeof(unsigned long) * sys_data->nb_args; | |
338 | ||
11034ae9 J |
339 | local_save_flags(irq_flags); |
340 | pc = preempt_count(); | |
341 | ||
12883efb | 342 | buffer = tr->trace_buffer.buffer; |
12ab74ee | 343 | event = trace_buffer_lock_reserve(buffer, |
11034ae9 | 344 | sys_data->enter_event->event.type, size, irq_flags, pc); |
bed1ffca FW |
345 | if (!event) |
346 | return; | |
347 | ||
348 | entry = ring_buffer_event_data(event); | |
349 | entry->nr = syscall_nr; | |
350 | syscall_get_arguments(current, regs, 0, sys_data->nb_args, entry->args); | |
351 | ||
7f1d2f82 | 352 | event_trigger_unlock_commit(trace_file, buffer, event, entry, |
13a1e4ae | 353 | irq_flags, pc); |
ee08c6ec FW |
354 | } |
355 | ||
12ab74ee | 356 | static void ftrace_syscall_exit(void *data, struct pt_regs *regs, long ret) |
ee08c6ec | 357 | { |
12ab74ee | 358 | struct trace_array *tr = data; |
7f1d2f82 | 359 | struct trace_event_file *trace_file; |
bed1ffca FW |
360 | struct syscall_trace_exit *entry; |
361 | struct syscall_metadata *sys_data; | |
362 | struct ring_buffer_event *event; | |
e77405ad | 363 | struct ring_buffer *buffer; |
11034ae9 J |
364 | unsigned long irq_flags; |
365 | int pc; | |
ee08c6ec FW |
366 | int syscall_nr; |
367 | ||
f431b634 | 368 | syscall_nr = trace_get_syscall_nr(current, regs); |
086ba77a | 369 | if (syscall_nr < 0 || syscall_nr >= NR_syscalls) |
cd0980fc | 370 | return; |
d562aff9 TZ |
371 | |
372 | /* Here we're inside tp handler's rcu_read_lock_sched (__DO_TRACE()) */ | |
7f1d2f82 SRRH |
373 | trace_file = rcu_dereference_sched(tr->exit_syscall_files[syscall_nr]); |
374 | if (!trace_file) | |
d562aff9 TZ |
375 | return; |
376 | ||
09a5059a | 377 | if (trace_trigger_soft_disabled(trace_file)) |
13a1e4ae | 378 | return; |
ee08c6ec | 379 | |
bed1ffca FW |
380 | sys_data = syscall_nr_to_meta(syscall_nr); |
381 | if (!sys_data) | |
382 | return; | |
383 | ||
11034ae9 J |
384 | local_save_flags(irq_flags); |
385 | pc = preempt_count(); | |
386 | ||
12883efb | 387 | buffer = tr->trace_buffer.buffer; |
12ab74ee | 388 | event = trace_buffer_lock_reserve(buffer, |
11034ae9 J |
389 | sys_data->exit_event->event.type, sizeof(*entry), |
390 | irq_flags, pc); | |
bed1ffca FW |
391 | if (!event) |
392 | return; | |
393 | ||
394 | entry = ring_buffer_event_data(event); | |
395 | entry->nr = syscall_nr; | |
396 | entry->ret = syscall_get_return_value(current, regs); | |
397 | ||
7f1d2f82 | 398 | event_trigger_unlock_commit(trace_file, buffer, event, entry, |
13a1e4ae | 399 | irq_flags, pc); |
ee08c6ec FW |
400 | } |
401 | ||
7f1d2f82 | 402 | static int reg_event_syscall_enter(struct trace_event_file *file, |
2425bcb9 | 403 | struct trace_event_call *call) |
ee08c6ec | 404 | { |
12ab74ee | 405 | struct trace_array *tr = file->tr; |
fb34a08c JB |
406 | int ret = 0; |
407 | int num; | |
fb34a08c | 408 | |
c252f657 | 409 | num = ((struct syscall_metadata *)call->data)->syscall_nr; |
3773b389 | 410 | if (WARN_ON_ONCE(num < 0 || num >= NR_syscalls)) |
fb34a08c JB |
411 | return -ENOSYS; |
412 | mutex_lock(&syscall_trace_lock); | |
12ab74ee SR |
413 | if (!tr->sys_refcount_enter) |
414 | ret = register_trace_sys_enter(ftrace_syscall_enter, tr); | |
3b8e4273 | 415 | if (!ret) { |
d562aff9 | 416 | rcu_assign_pointer(tr->enter_syscall_files[num], file); |
12ab74ee | 417 | tr->sys_refcount_enter++; |
fb34a08c JB |
418 | } |
419 | mutex_unlock(&syscall_trace_lock); | |
420 | return ret; | |
ee08c6ec FW |
421 | } |
422 | ||
7f1d2f82 | 423 | static void unreg_event_syscall_enter(struct trace_event_file *file, |
2425bcb9 | 424 | struct trace_event_call *call) |
ee08c6ec | 425 | { |
12ab74ee | 426 | struct trace_array *tr = file->tr; |
fb34a08c | 427 | int num; |
ee08c6ec | 428 | |
c252f657 | 429 | num = ((struct syscall_metadata *)call->data)->syscall_nr; |
3773b389 | 430 | if (WARN_ON_ONCE(num < 0 || num >= NR_syscalls)) |
fb34a08c JB |
431 | return; |
432 | mutex_lock(&syscall_trace_lock); | |
12ab74ee | 433 | tr->sys_refcount_enter--; |
fb5a613b | 434 | RCU_INIT_POINTER(tr->enter_syscall_files[num], NULL); |
12ab74ee SR |
435 | if (!tr->sys_refcount_enter) |
436 | unregister_trace_sys_enter(ftrace_syscall_enter, tr); | |
fb34a08c JB |
437 | mutex_unlock(&syscall_trace_lock); |
438 | } | |
ee08c6ec | 439 | |
7f1d2f82 | 440 | static int reg_event_syscall_exit(struct trace_event_file *file, |
2425bcb9 | 441 | struct trace_event_call *call) |
ee08c6ec | 442 | { |
12ab74ee | 443 | struct trace_array *tr = file->tr; |
fb34a08c JB |
444 | int ret = 0; |
445 | int num; | |
fb34a08c | 446 | |
c252f657 | 447 | num = ((struct syscall_metadata *)call->data)->syscall_nr; |
3773b389 | 448 | if (WARN_ON_ONCE(num < 0 || num >= NR_syscalls)) |
fb34a08c JB |
449 | return -ENOSYS; |
450 | mutex_lock(&syscall_trace_lock); | |
12ab74ee SR |
451 | if (!tr->sys_refcount_exit) |
452 | ret = register_trace_sys_exit(ftrace_syscall_exit, tr); | |
3b8e4273 | 453 | if (!ret) { |
d562aff9 | 454 | rcu_assign_pointer(tr->exit_syscall_files[num], file); |
12ab74ee | 455 | tr->sys_refcount_exit++; |
ee08c6ec | 456 | } |
fb34a08c JB |
457 | mutex_unlock(&syscall_trace_lock); |
458 | return ret; | |
459 | } | |
ee08c6ec | 460 | |
7f1d2f82 | 461 | static void unreg_event_syscall_exit(struct trace_event_file *file, |
2425bcb9 | 462 | struct trace_event_call *call) |
fb34a08c | 463 | { |
12ab74ee | 464 | struct trace_array *tr = file->tr; |
fb34a08c | 465 | int num; |
ee08c6ec | 466 | |
c252f657 | 467 | num = ((struct syscall_metadata *)call->data)->syscall_nr; |
3773b389 | 468 | if (WARN_ON_ONCE(num < 0 || num >= NR_syscalls)) |
fb34a08c JB |
469 | return; |
470 | mutex_lock(&syscall_trace_lock); | |
12ab74ee | 471 | tr->sys_refcount_exit--; |
fb5a613b | 472 | RCU_INIT_POINTER(tr->exit_syscall_files[num], NULL); |
12ab74ee SR |
473 | if (!tr->sys_refcount_exit) |
474 | unregister_trace_sys_exit(ftrace_syscall_exit, tr); | |
fb34a08c | 475 | mutex_unlock(&syscall_trace_lock); |
ee08c6ec | 476 | } |
fb34a08c | 477 | |
2425bcb9 | 478 | static int __init init_syscall_trace(struct trace_event_call *call) |
a1301da0 LJ |
479 | { |
480 | int id; | |
ba976970 IM |
481 | int num; |
482 | ||
483 | num = ((struct syscall_metadata *)call->data)->syscall_nr; | |
484 | if (num < 0 || num >= NR_syscalls) { | |
485 | pr_debug("syscall %s metadata not mapped, disabling ftrace event\n", | |
486 | ((struct syscall_metadata *)call->data)->name); | |
487 | return -ENOSYS; | |
488 | } | |
a1301da0 | 489 | |
50307a45 LJ |
490 | if (set_syscall_print_fmt(call) < 0) |
491 | return -ENOMEM; | |
492 | ||
c7ef3a90 SR |
493 | id = trace_event_raw_init(call); |
494 | ||
495 | if (id < 0) { | |
50307a45 | 496 | free_syscall_print_fmt(call); |
c7ef3a90 | 497 | return id; |
50307a45 | 498 | } |
c7ef3a90 SR |
499 | |
500 | return id; | |
a1301da0 LJ |
501 | } |
502 | ||
6f86ab9f VN |
503 | struct trace_event_functions enter_syscall_print_funcs = { |
504 | .trace = print_syscall_enter, | |
505 | }; | |
506 | ||
507 | struct trace_event_functions exit_syscall_print_funcs = { | |
508 | .trace = print_syscall_exit, | |
509 | }; | |
510 | ||
2425bcb9 | 511 | struct trace_event_class __refdata event_class_syscall_enter = { |
6f86ab9f VN |
512 | .system = "syscalls", |
513 | .reg = syscall_enter_register, | |
514 | .define_fields = syscall_enter_define_fields, | |
515 | .get_fields = syscall_get_enter_fields, | |
516 | .raw_init = init_syscall_trace, | |
517 | }; | |
518 | ||
2425bcb9 | 519 | struct trace_event_class __refdata event_class_syscall_exit = { |
6f86ab9f VN |
520 | .system = "syscalls", |
521 | .reg = syscall_exit_register, | |
522 | .define_fields = syscall_exit_define_fields, | |
523 | .fields = LIST_HEAD_INIT(event_class_syscall_exit.fields), | |
524 | .raw_init = init_syscall_trace, | |
525 | }; | |
526 | ||
c763ba06 | 527 | unsigned long __init __weak arch_syscall_addr(int nr) |
e7b8e675 MF |
528 | { |
529 | return (unsigned long)sys_call_table[nr]; | |
530 | } | |
531 | ||
5f893b26 | 532 | void __init init_ftrace_syscalls(void) |
c44fc770 FW |
533 | { |
534 | struct syscall_metadata *meta; | |
535 | unsigned long addr; | |
536 | int i; | |
537 | ||
47b0edcb TM |
538 | syscalls_metadata = kcalloc(NR_syscalls, sizeof(*syscalls_metadata), |
539 | GFP_KERNEL); | |
c44fc770 FW |
540 | if (!syscalls_metadata) { |
541 | WARN_ON(1); | |
5f893b26 | 542 | return; |
c44fc770 FW |
543 | } |
544 | ||
545 | for (i = 0; i < NR_syscalls; i++) { | |
546 | addr = arch_syscall_addr(i); | |
547 | meta = find_syscall_meta(addr); | |
c252f657 LJ |
548 | if (!meta) |
549 | continue; | |
550 | ||
551 | meta->syscall_nr = i; | |
c44fc770 FW |
552 | syscalls_metadata[i] = meta; |
553 | } | |
c44fc770 | 554 | } |
c44fc770 | 555 | |
07b139c8 | 556 | #ifdef CONFIG_PERF_EVENTS |
19007a67 | 557 | |
97d5a220 FW |
558 | static DECLARE_BITMAP(enabled_perf_enter_syscalls, NR_syscalls); |
559 | static DECLARE_BITMAP(enabled_perf_exit_syscalls, NR_syscalls); | |
560 | static int sys_perf_refcount_enter; | |
561 | static int sys_perf_refcount_exit; | |
f4b5ffcc | 562 | |
e87c6bc3 YS |
563 | static int perf_call_bpf_enter(struct trace_event_call *call, struct pt_regs *regs, |
564 | struct syscall_metadata *sys_data, | |
565 | struct syscall_trace_enter *rec) | |
566 | { | |
cf5f5cea YS |
567 | struct syscall_tp_t { |
568 | unsigned long long regs; | |
569 | unsigned long syscall_nr; | |
609320c8 | 570 | unsigned long args[SYSCALL_DEFINE_MAXARGS]; |
cf5f5cea YS |
571 | } param; |
572 | int i; | |
573 | ||
574 | *(struct pt_regs **)¶m = regs; | |
575 | param.syscall_nr = rec->nr; | |
576 | for (i = 0; i < sys_data->nb_args; i++) | |
577 | param.args[i] = rec->args[i]; | |
e87c6bc3 | 578 | return trace_call_bpf(call, ¶m); |
cf5f5cea YS |
579 | } |
580 | ||
38516ab5 | 581 | static void perf_syscall_enter(void *ignore, struct pt_regs *regs, long id) |
f4b5ffcc JB |
582 | { |
583 | struct syscall_metadata *sys_data; | |
20ab4425 | 584 | struct syscall_trace_enter *rec; |
1c024eca | 585 | struct hlist_head *head; |
e87c6bc3 | 586 | bool valid_prog_array; |
f4b5ffcc | 587 | int syscall_nr; |
4ed7c92d | 588 | int rctx; |
19007a67 | 589 | int size; |
f4b5ffcc | 590 | |
f431b634 | 591 | syscall_nr = trace_get_syscall_nr(current, regs); |
086ba77a | 592 | if (syscall_nr < 0 || syscall_nr >= NR_syscalls) |
60916a93 | 593 | return; |
97d5a220 | 594 | if (!test_bit(syscall_nr, enabled_perf_enter_syscalls)) |
f4b5ffcc JB |
595 | return; |
596 | ||
597 | sys_data = syscall_nr_to_meta(syscall_nr); | |
598 | if (!sys_data) | |
599 | return; | |
600 | ||
421c7860 | 601 | head = this_cpu_ptr(sys_data->enter_event->perf_events); |
e87c6bc3 YS |
602 | valid_prog_array = bpf_prog_array_valid(sys_data->enter_event); |
603 | if (!valid_prog_array && hlist_empty(head)) | |
421c7860 ON |
604 | return; |
605 | ||
19007a67 FW |
606 | /* get the size after alignment with the u32 buffer size field */ |
607 | size = sizeof(unsigned long) * sys_data->nb_args + sizeof(*rec); | |
608 | size = ALIGN(size + sizeof(u32), sizeof(u64)); | |
609 | size -= sizeof(u32); | |
610 | ||
1e1dcd93 | 611 | rec = perf_trace_buf_alloc(size, NULL, &rctx); |
430ad5a6 XG |
612 | if (!rec) |
613 | return; | |
20ab4425 | 614 | |
20ab4425 FW |
615 | rec->nr = syscall_nr; |
616 | syscall_get_arguments(current, regs, 0, sys_data->nb_args, | |
617 | (unsigned long *)&rec->args); | |
cf5f5cea | 618 | |
e87c6bc3 YS |
619 | if ((valid_prog_array && |
620 | !perf_call_bpf_enter(sys_data->enter_event, regs, sys_data, rec)) || | |
cf5f5cea YS |
621 | hlist_empty(head)) { |
622 | perf_swevent_put_recursion_context(rctx); | |
623 | return; | |
624 | } | |
625 | ||
1e1dcd93 AS |
626 | perf_trace_buf_submit(rec, size, rctx, |
627 | sys_data->enter_event->event.type, 1, regs, | |
8fd0fbbe | 628 | head, NULL); |
f4b5ffcc JB |
629 | } |
630 | ||
2425bcb9 | 631 | static int perf_sysenter_enable(struct trace_event_call *call) |
f4b5ffcc JB |
632 | { |
633 | int ret = 0; | |
634 | int num; | |
635 | ||
3bbe84e9 | 636 | num = ((struct syscall_metadata *)call->data)->syscall_nr; |
f4b5ffcc JB |
637 | |
638 | mutex_lock(&syscall_trace_lock); | |
97d5a220 | 639 | if (!sys_perf_refcount_enter) |
38516ab5 | 640 | ret = register_trace_sys_enter(perf_syscall_enter, NULL); |
f4b5ffcc | 641 | if (ret) { |
d282b9c0 | 642 | pr_info("event trace: Could not activate syscall entry trace point"); |
f4b5ffcc | 643 | } else { |
97d5a220 FW |
644 | set_bit(num, enabled_perf_enter_syscalls); |
645 | sys_perf_refcount_enter++; | |
f4b5ffcc JB |
646 | } |
647 | mutex_unlock(&syscall_trace_lock); | |
648 | return ret; | |
649 | } | |
650 | ||
2425bcb9 | 651 | static void perf_sysenter_disable(struct trace_event_call *call) |
f4b5ffcc JB |
652 | { |
653 | int num; | |
654 | ||
3bbe84e9 | 655 | num = ((struct syscall_metadata *)call->data)->syscall_nr; |
f4b5ffcc JB |
656 | |
657 | mutex_lock(&syscall_trace_lock); | |
97d5a220 FW |
658 | sys_perf_refcount_enter--; |
659 | clear_bit(num, enabled_perf_enter_syscalls); | |
660 | if (!sys_perf_refcount_enter) | |
38516ab5 | 661 | unregister_trace_sys_enter(perf_syscall_enter, NULL); |
f4b5ffcc JB |
662 | mutex_unlock(&syscall_trace_lock); |
663 | } | |
664 | ||
e87c6bc3 YS |
665 | static int perf_call_bpf_exit(struct trace_event_call *call, struct pt_regs *regs, |
666 | struct syscall_trace_exit *rec) | |
667 | { | |
cf5f5cea YS |
668 | struct syscall_tp_t { |
669 | unsigned long long regs; | |
670 | unsigned long syscall_nr; | |
671 | unsigned long ret; | |
672 | } param; | |
673 | ||
674 | *(struct pt_regs **)¶m = regs; | |
675 | param.syscall_nr = rec->nr; | |
676 | param.ret = rec->ret; | |
e87c6bc3 | 677 | return trace_call_bpf(call, ¶m); |
cf5f5cea YS |
678 | } |
679 | ||
38516ab5 | 680 | static void perf_syscall_exit(void *ignore, struct pt_regs *regs, long ret) |
f4b5ffcc JB |
681 | { |
682 | struct syscall_metadata *sys_data; | |
20ab4425 | 683 | struct syscall_trace_exit *rec; |
1c024eca | 684 | struct hlist_head *head; |
e87c6bc3 | 685 | bool valid_prog_array; |
f4b5ffcc | 686 | int syscall_nr; |
4ed7c92d | 687 | int rctx; |
20ab4425 | 688 | int size; |
f4b5ffcc | 689 | |
f431b634 | 690 | syscall_nr = trace_get_syscall_nr(current, regs); |
086ba77a | 691 | if (syscall_nr < 0 || syscall_nr >= NR_syscalls) |
60916a93 | 692 | return; |
97d5a220 | 693 | if (!test_bit(syscall_nr, enabled_perf_exit_syscalls)) |
f4b5ffcc JB |
694 | return; |
695 | ||
696 | sys_data = syscall_nr_to_meta(syscall_nr); | |
697 | if (!sys_data) | |
698 | return; | |
699 | ||
421c7860 | 700 | head = this_cpu_ptr(sys_data->exit_event->perf_events); |
e87c6bc3 YS |
701 | valid_prog_array = bpf_prog_array_valid(sys_data->exit_event); |
702 | if (!valid_prog_array && hlist_empty(head)) | |
421c7860 ON |
703 | return; |
704 | ||
20ab4425 FW |
705 | /* We can probably do that at build time */ |
706 | size = ALIGN(sizeof(*rec) + sizeof(u32), sizeof(u64)); | |
707 | size -= sizeof(u32); | |
19007a67 | 708 | |
1e1dcd93 | 709 | rec = perf_trace_buf_alloc(size, NULL, &rctx); |
430ad5a6 XG |
710 | if (!rec) |
711 | return; | |
20ab4425 | 712 | |
20ab4425 FW |
713 | rec->nr = syscall_nr; |
714 | rec->ret = syscall_get_return_value(current, regs); | |
cf5f5cea | 715 | |
e87c6bc3 YS |
716 | if ((valid_prog_array && |
717 | !perf_call_bpf_exit(sys_data->exit_event, regs, rec)) || | |
cf5f5cea YS |
718 | hlist_empty(head)) { |
719 | perf_swevent_put_recursion_context(rctx); | |
720 | return; | |
721 | } | |
722 | ||
1e1dcd93 | 723 | perf_trace_buf_submit(rec, size, rctx, sys_data->exit_event->event.type, |
8fd0fbbe | 724 | 1, regs, head, NULL); |
f4b5ffcc JB |
725 | } |
726 | ||
2425bcb9 | 727 | static int perf_sysexit_enable(struct trace_event_call *call) |
f4b5ffcc JB |
728 | { |
729 | int ret = 0; | |
730 | int num; | |
731 | ||
3bbe84e9 | 732 | num = ((struct syscall_metadata *)call->data)->syscall_nr; |
f4b5ffcc JB |
733 | |
734 | mutex_lock(&syscall_trace_lock); | |
97d5a220 | 735 | if (!sys_perf_refcount_exit) |
38516ab5 | 736 | ret = register_trace_sys_exit(perf_syscall_exit, NULL); |
f4b5ffcc | 737 | if (ret) { |
d282b9c0 | 738 | pr_info("event trace: Could not activate syscall exit trace point"); |
f4b5ffcc | 739 | } else { |
97d5a220 FW |
740 | set_bit(num, enabled_perf_exit_syscalls); |
741 | sys_perf_refcount_exit++; | |
f4b5ffcc JB |
742 | } |
743 | mutex_unlock(&syscall_trace_lock); | |
744 | return ret; | |
745 | } | |
746 | ||
2425bcb9 | 747 | static void perf_sysexit_disable(struct trace_event_call *call) |
f4b5ffcc JB |
748 | { |
749 | int num; | |
750 | ||
3bbe84e9 | 751 | num = ((struct syscall_metadata *)call->data)->syscall_nr; |
f4b5ffcc JB |
752 | |
753 | mutex_lock(&syscall_trace_lock); | |
97d5a220 FW |
754 | sys_perf_refcount_exit--; |
755 | clear_bit(num, enabled_perf_exit_syscalls); | |
756 | if (!sys_perf_refcount_exit) | |
38516ab5 | 757 | unregister_trace_sys_exit(perf_syscall_exit, NULL); |
f4b5ffcc JB |
758 | mutex_unlock(&syscall_trace_lock); |
759 | } | |
760 | ||
07b139c8 | 761 | #endif /* CONFIG_PERF_EVENTS */ |
f4b5ffcc | 762 | |
2425bcb9 | 763 | static int syscall_enter_register(struct trace_event_call *event, |
ceec0b6f | 764 | enum trace_reg type, void *data) |
2239291a | 765 | { |
7f1d2f82 | 766 | struct trace_event_file *file = data; |
12ab74ee | 767 | |
2239291a SR |
768 | switch (type) { |
769 | case TRACE_REG_REGISTER: | |
12ab74ee | 770 | return reg_event_syscall_enter(file, event); |
2239291a | 771 | case TRACE_REG_UNREGISTER: |
12ab74ee | 772 | unreg_event_syscall_enter(file, event); |
2239291a SR |
773 | return 0; |
774 | ||
775 | #ifdef CONFIG_PERF_EVENTS | |
776 | case TRACE_REG_PERF_REGISTER: | |
777 | return perf_sysenter_enable(event); | |
778 | case TRACE_REG_PERF_UNREGISTER: | |
779 | perf_sysenter_disable(event); | |
780 | return 0; | |
ceec0b6f JO |
781 | case TRACE_REG_PERF_OPEN: |
782 | case TRACE_REG_PERF_CLOSE: | |
489c75c3 JO |
783 | case TRACE_REG_PERF_ADD: |
784 | case TRACE_REG_PERF_DEL: | |
ceec0b6f | 785 | return 0; |
2239291a SR |
786 | #endif |
787 | } | |
788 | return 0; | |
789 | } | |
790 | ||
2425bcb9 | 791 | static int syscall_exit_register(struct trace_event_call *event, |
ceec0b6f | 792 | enum trace_reg type, void *data) |
2239291a | 793 | { |
7f1d2f82 | 794 | struct trace_event_file *file = data; |
12ab74ee | 795 | |
2239291a SR |
796 | switch (type) { |
797 | case TRACE_REG_REGISTER: | |
12ab74ee | 798 | return reg_event_syscall_exit(file, event); |
2239291a | 799 | case TRACE_REG_UNREGISTER: |
12ab74ee | 800 | unreg_event_syscall_exit(file, event); |
2239291a SR |
801 | return 0; |
802 | ||
803 | #ifdef CONFIG_PERF_EVENTS | |
804 | case TRACE_REG_PERF_REGISTER: | |
805 | return perf_sysexit_enable(event); | |
806 | case TRACE_REG_PERF_UNREGISTER: | |
807 | perf_sysexit_disable(event); | |
808 | return 0; | |
ceec0b6f JO |
809 | case TRACE_REG_PERF_OPEN: |
810 | case TRACE_REG_PERF_CLOSE: | |
489c75c3 JO |
811 | case TRACE_REG_PERF_ADD: |
812 | case TRACE_REG_PERF_DEL: | |
ceec0b6f | 813 | return 0; |
2239291a SR |
814 | #endif |
815 | } | |
816 | return 0; | |
817 | } |