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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 | 316 | unsigned long irq_flags; |
d08e4113 | 317 | unsigned long args[6]; |
11034ae9 | 318 | int pc; |
ee08c6ec | 319 | int syscall_nr; |
f431b634 | 320 | int size; |
ee08c6ec | 321 | |
f431b634 | 322 | syscall_nr = trace_get_syscall_nr(current, regs); |
086ba77a | 323 | if (syscall_nr < 0 || syscall_nr >= NR_syscalls) |
cd0980fc | 324 | return; |
d562aff9 TZ |
325 | |
326 | /* Here we're inside tp handler's rcu_read_lock_sched (__DO_TRACE) */ | |
7f1d2f82 SRRH |
327 | trace_file = rcu_dereference_sched(tr->enter_syscall_files[syscall_nr]); |
328 | if (!trace_file) | |
d562aff9 TZ |
329 | return; |
330 | ||
09a5059a | 331 | if (trace_trigger_soft_disabled(trace_file)) |
13a1e4ae | 332 | return; |
ee08c6ec | 333 | |
bed1ffca FW |
334 | sys_data = syscall_nr_to_meta(syscall_nr); |
335 | if (!sys_data) | |
336 | return; | |
337 | ||
338 | size = sizeof(*entry) + sizeof(unsigned long) * sys_data->nb_args; | |
339 | ||
11034ae9 J |
340 | local_save_flags(irq_flags); |
341 | pc = preempt_count(); | |
342 | ||
12883efb | 343 | buffer = tr->trace_buffer.buffer; |
12ab74ee | 344 | event = trace_buffer_lock_reserve(buffer, |
11034ae9 | 345 | sys_data->enter_event->event.type, size, irq_flags, pc); |
bed1ffca FW |
346 | if (!event) |
347 | return; | |
348 | ||
349 | entry = ring_buffer_event_data(event); | |
350 | entry->nr = syscall_nr; | |
b35f549d | 351 | syscall_get_arguments(current, regs, args); |
d08e4113 | 352 | memcpy(entry->args, args, sizeof(unsigned long) * sys_data->nb_args); |
bed1ffca | 353 | |
7f1d2f82 | 354 | event_trigger_unlock_commit(trace_file, buffer, event, entry, |
13a1e4ae | 355 | irq_flags, pc); |
ee08c6ec FW |
356 | } |
357 | ||
12ab74ee | 358 | static void ftrace_syscall_exit(void *data, struct pt_regs *regs, long ret) |
ee08c6ec | 359 | { |
12ab74ee | 360 | struct trace_array *tr = data; |
7f1d2f82 | 361 | struct trace_event_file *trace_file; |
bed1ffca FW |
362 | struct syscall_trace_exit *entry; |
363 | struct syscall_metadata *sys_data; | |
364 | struct ring_buffer_event *event; | |
e77405ad | 365 | struct ring_buffer *buffer; |
11034ae9 J |
366 | unsigned long irq_flags; |
367 | int pc; | |
ee08c6ec FW |
368 | int syscall_nr; |
369 | ||
f431b634 | 370 | syscall_nr = trace_get_syscall_nr(current, regs); |
086ba77a | 371 | if (syscall_nr < 0 || syscall_nr >= NR_syscalls) |
cd0980fc | 372 | return; |
d562aff9 TZ |
373 | |
374 | /* Here we're inside tp handler's rcu_read_lock_sched (__DO_TRACE()) */ | |
7f1d2f82 SRRH |
375 | trace_file = rcu_dereference_sched(tr->exit_syscall_files[syscall_nr]); |
376 | if (!trace_file) | |
d562aff9 TZ |
377 | return; |
378 | ||
09a5059a | 379 | if (trace_trigger_soft_disabled(trace_file)) |
13a1e4ae | 380 | return; |
ee08c6ec | 381 | |
bed1ffca FW |
382 | sys_data = syscall_nr_to_meta(syscall_nr); |
383 | if (!sys_data) | |
384 | return; | |
385 | ||
11034ae9 J |
386 | local_save_flags(irq_flags); |
387 | pc = preempt_count(); | |
388 | ||
12883efb | 389 | buffer = tr->trace_buffer.buffer; |
12ab74ee | 390 | event = trace_buffer_lock_reserve(buffer, |
11034ae9 J |
391 | sys_data->exit_event->event.type, sizeof(*entry), |
392 | irq_flags, pc); | |
bed1ffca FW |
393 | if (!event) |
394 | return; | |
395 | ||
396 | entry = ring_buffer_event_data(event); | |
397 | entry->nr = syscall_nr; | |
398 | entry->ret = syscall_get_return_value(current, regs); | |
399 | ||
7f1d2f82 | 400 | event_trigger_unlock_commit(trace_file, buffer, event, entry, |
13a1e4ae | 401 | irq_flags, pc); |
ee08c6ec FW |
402 | } |
403 | ||
7f1d2f82 | 404 | static int reg_event_syscall_enter(struct trace_event_file *file, |
2425bcb9 | 405 | struct trace_event_call *call) |
ee08c6ec | 406 | { |
12ab74ee | 407 | struct trace_array *tr = file->tr; |
fb34a08c JB |
408 | int ret = 0; |
409 | int num; | |
fb34a08c | 410 | |
c252f657 | 411 | num = ((struct syscall_metadata *)call->data)->syscall_nr; |
3773b389 | 412 | if (WARN_ON_ONCE(num < 0 || num >= NR_syscalls)) |
fb34a08c JB |
413 | return -ENOSYS; |
414 | mutex_lock(&syscall_trace_lock); | |
12ab74ee SR |
415 | if (!tr->sys_refcount_enter) |
416 | ret = register_trace_sys_enter(ftrace_syscall_enter, tr); | |
3b8e4273 | 417 | if (!ret) { |
d562aff9 | 418 | rcu_assign_pointer(tr->enter_syscall_files[num], file); |
12ab74ee | 419 | tr->sys_refcount_enter++; |
fb34a08c JB |
420 | } |
421 | mutex_unlock(&syscall_trace_lock); | |
422 | return ret; | |
ee08c6ec FW |
423 | } |
424 | ||
7f1d2f82 | 425 | static void unreg_event_syscall_enter(struct trace_event_file *file, |
2425bcb9 | 426 | struct trace_event_call *call) |
ee08c6ec | 427 | { |
12ab74ee | 428 | struct trace_array *tr = file->tr; |
fb34a08c | 429 | int num; |
ee08c6ec | 430 | |
c252f657 | 431 | num = ((struct syscall_metadata *)call->data)->syscall_nr; |
3773b389 | 432 | if (WARN_ON_ONCE(num < 0 || num >= NR_syscalls)) |
fb34a08c JB |
433 | return; |
434 | mutex_lock(&syscall_trace_lock); | |
12ab74ee | 435 | tr->sys_refcount_enter--; |
fb5a613b | 436 | RCU_INIT_POINTER(tr->enter_syscall_files[num], NULL); |
12ab74ee SR |
437 | if (!tr->sys_refcount_enter) |
438 | unregister_trace_sys_enter(ftrace_syscall_enter, tr); | |
fb34a08c JB |
439 | mutex_unlock(&syscall_trace_lock); |
440 | } | |
ee08c6ec | 441 | |
7f1d2f82 | 442 | static int reg_event_syscall_exit(struct trace_event_file *file, |
2425bcb9 | 443 | struct trace_event_call *call) |
ee08c6ec | 444 | { |
12ab74ee | 445 | struct trace_array *tr = file->tr; |
fb34a08c JB |
446 | int ret = 0; |
447 | int num; | |
fb34a08c | 448 | |
c252f657 | 449 | num = ((struct syscall_metadata *)call->data)->syscall_nr; |
3773b389 | 450 | if (WARN_ON_ONCE(num < 0 || num >= NR_syscalls)) |
fb34a08c JB |
451 | return -ENOSYS; |
452 | mutex_lock(&syscall_trace_lock); | |
12ab74ee SR |
453 | if (!tr->sys_refcount_exit) |
454 | ret = register_trace_sys_exit(ftrace_syscall_exit, tr); | |
3b8e4273 | 455 | if (!ret) { |
d562aff9 | 456 | rcu_assign_pointer(tr->exit_syscall_files[num], file); |
12ab74ee | 457 | tr->sys_refcount_exit++; |
ee08c6ec | 458 | } |
fb34a08c JB |
459 | mutex_unlock(&syscall_trace_lock); |
460 | return ret; | |
461 | } | |
ee08c6ec | 462 | |
7f1d2f82 | 463 | static void unreg_event_syscall_exit(struct trace_event_file *file, |
2425bcb9 | 464 | struct trace_event_call *call) |
fb34a08c | 465 | { |
12ab74ee | 466 | struct trace_array *tr = file->tr; |
fb34a08c | 467 | int num; |
ee08c6ec | 468 | |
c252f657 | 469 | num = ((struct syscall_metadata *)call->data)->syscall_nr; |
3773b389 | 470 | if (WARN_ON_ONCE(num < 0 || num >= NR_syscalls)) |
fb34a08c JB |
471 | return; |
472 | mutex_lock(&syscall_trace_lock); | |
12ab74ee | 473 | tr->sys_refcount_exit--; |
fb5a613b | 474 | RCU_INIT_POINTER(tr->exit_syscall_files[num], NULL); |
12ab74ee SR |
475 | if (!tr->sys_refcount_exit) |
476 | unregister_trace_sys_exit(ftrace_syscall_exit, tr); | |
fb34a08c | 477 | mutex_unlock(&syscall_trace_lock); |
ee08c6ec | 478 | } |
fb34a08c | 479 | |
2425bcb9 | 480 | static int __init init_syscall_trace(struct trace_event_call *call) |
a1301da0 LJ |
481 | { |
482 | int id; | |
ba976970 IM |
483 | int num; |
484 | ||
485 | num = ((struct syscall_metadata *)call->data)->syscall_nr; | |
486 | if (num < 0 || num >= NR_syscalls) { | |
487 | pr_debug("syscall %s metadata not mapped, disabling ftrace event\n", | |
488 | ((struct syscall_metadata *)call->data)->name); | |
489 | return -ENOSYS; | |
490 | } | |
a1301da0 | 491 | |
50307a45 LJ |
492 | if (set_syscall_print_fmt(call) < 0) |
493 | return -ENOMEM; | |
494 | ||
c7ef3a90 SR |
495 | id = trace_event_raw_init(call); |
496 | ||
497 | if (id < 0) { | |
50307a45 | 498 | free_syscall_print_fmt(call); |
c7ef3a90 | 499 | return id; |
50307a45 | 500 | } |
c7ef3a90 SR |
501 | |
502 | return id; | |
a1301da0 LJ |
503 | } |
504 | ||
6f86ab9f VN |
505 | struct trace_event_functions enter_syscall_print_funcs = { |
506 | .trace = print_syscall_enter, | |
507 | }; | |
508 | ||
509 | struct trace_event_functions exit_syscall_print_funcs = { | |
510 | .trace = print_syscall_exit, | |
511 | }; | |
512 | ||
2425bcb9 | 513 | struct trace_event_class __refdata event_class_syscall_enter = { |
6f86ab9f VN |
514 | .system = "syscalls", |
515 | .reg = syscall_enter_register, | |
516 | .define_fields = syscall_enter_define_fields, | |
517 | .get_fields = syscall_get_enter_fields, | |
518 | .raw_init = init_syscall_trace, | |
519 | }; | |
520 | ||
2425bcb9 | 521 | struct trace_event_class __refdata event_class_syscall_exit = { |
6f86ab9f VN |
522 | .system = "syscalls", |
523 | .reg = syscall_exit_register, | |
524 | .define_fields = syscall_exit_define_fields, | |
525 | .fields = LIST_HEAD_INIT(event_class_syscall_exit.fields), | |
526 | .raw_init = init_syscall_trace, | |
527 | }; | |
528 | ||
c763ba06 | 529 | unsigned long __init __weak arch_syscall_addr(int nr) |
e7b8e675 MF |
530 | { |
531 | return (unsigned long)sys_call_table[nr]; | |
532 | } | |
533 | ||
5f893b26 | 534 | void __init init_ftrace_syscalls(void) |
c44fc770 FW |
535 | { |
536 | struct syscall_metadata *meta; | |
537 | unsigned long addr; | |
538 | int i; | |
539 | ||
47b0edcb TM |
540 | syscalls_metadata = kcalloc(NR_syscalls, sizeof(*syscalls_metadata), |
541 | GFP_KERNEL); | |
c44fc770 FW |
542 | if (!syscalls_metadata) { |
543 | WARN_ON(1); | |
5f893b26 | 544 | return; |
c44fc770 FW |
545 | } |
546 | ||
547 | for (i = 0; i < NR_syscalls; i++) { | |
548 | addr = arch_syscall_addr(i); | |
549 | meta = find_syscall_meta(addr); | |
c252f657 LJ |
550 | if (!meta) |
551 | continue; | |
552 | ||
553 | meta->syscall_nr = i; | |
c44fc770 FW |
554 | syscalls_metadata[i] = meta; |
555 | } | |
c44fc770 | 556 | } |
c44fc770 | 557 | |
07b139c8 | 558 | #ifdef CONFIG_PERF_EVENTS |
19007a67 | 559 | |
97d5a220 FW |
560 | static DECLARE_BITMAP(enabled_perf_enter_syscalls, NR_syscalls); |
561 | static DECLARE_BITMAP(enabled_perf_exit_syscalls, NR_syscalls); | |
562 | static int sys_perf_refcount_enter; | |
563 | static int sys_perf_refcount_exit; | |
f4b5ffcc | 564 | |
e87c6bc3 YS |
565 | static int perf_call_bpf_enter(struct trace_event_call *call, struct pt_regs *regs, |
566 | struct syscall_metadata *sys_data, | |
567 | struct syscall_trace_enter *rec) | |
568 | { | |
cf5f5cea YS |
569 | struct syscall_tp_t { |
570 | unsigned long long regs; | |
571 | unsigned long syscall_nr; | |
609320c8 | 572 | unsigned long args[SYSCALL_DEFINE_MAXARGS]; |
cf5f5cea YS |
573 | } param; |
574 | int i; | |
575 | ||
576 | *(struct pt_regs **)¶m = regs; | |
577 | param.syscall_nr = rec->nr; | |
578 | for (i = 0; i < sys_data->nb_args; i++) | |
579 | param.args[i] = rec->args[i]; | |
e87c6bc3 | 580 | return trace_call_bpf(call, ¶m); |
cf5f5cea YS |
581 | } |
582 | ||
38516ab5 | 583 | static void perf_syscall_enter(void *ignore, struct pt_regs *regs, long id) |
f4b5ffcc JB |
584 | { |
585 | struct syscall_metadata *sys_data; | |
20ab4425 | 586 | struct syscall_trace_enter *rec; |
1c024eca | 587 | struct hlist_head *head; |
d08e4113 | 588 | unsigned long args[6]; |
e87c6bc3 | 589 | bool valid_prog_array; |
f4b5ffcc | 590 | int syscall_nr; |
4ed7c92d | 591 | int rctx; |
19007a67 | 592 | int size; |
f4b5ffcc | 593 | |
f431b634 | 594 | syscall_nr = trace_get_syscall_nr(current, regs); |
086ba77a | 595 | if (syscall_nr < 0 || syscall_nr >= NR_syscalls) |
60916a93 | 596 | return; |
97d5a220 | 597 | if (!test_bit(syscall_nr, enabled_perf_enter_syscalls)) |
f4b5ffcc JB |
598 | return; |
599 | ||
600 | sys_data = syscall_nr_to_meta(syscall_nr); | |
601 | if (!sys_data) | |
602 | return; | |
603 | ||
421c7860 | 604 | head = this_cpu_ptr(sys_data->enter_event->perf_events); |
e87c6bc3 YS |
605 | valid_prog_array = bpf_prog_array_valid(sys_data->enter_event); |
606 | if (!valid_prog_array && hlist_empty(head)) | |
421c7860 ON |
607 | return; |
608 | ||
19007a67 FW |
609 | /* get the size after alignment with the u32 buffer size field */ |
610 | size = sizeof(unsigned long) * sys_data->nb_args + sizeof(*rec); | |
611 | size = ALIGN(size + sizeof(u32), sizeof(u64)); | |
612 | size -= sizeof(u32); | |
613 | ||
1e1dcd93 | 614 | rec = perf_trace_buf_alloc(size, NULL, &rctx); |
430ad5a6 XG |
615 | if (!rec) |
616 | return; | |
20ab4425 | 617 | |
20ab4425 | 618 | rec->nr = syscall_nr; |
b35f549d | 619 | syscall_get_arguments(current, regs, args); |
d08e4113 | 620 | memcpy(&rec->args, args, sizeof(unsigned long) * sys_data->nb_args); |
cf5f5cea | 621 | |
e87c6bc3 YS |
622 | if ((valid_prog_array && |
623 | !perf_call_bpf_enter(sys_data->enter_event, regs, sys_data, rec)) || | |
cf5f5cea YS |
624 | hlist_empty(head)) { |
625 | perf_swevent_put_recursion_context(rctx); | |
626 | return; | |
627 | } | |
628 | ||
1e1dcd93 AS |
629 | perf_trace_buf_submit(rec, size, rctx, |
630 | sys_data->enter_event->event.type, 1, regs, | |
8fd0fbbe | 631 | head, NULL); |
f4b5ffcc JB |
632 | } |
633 | ||
2425bcb9 | 634 | static int perf_sysenter_enable(struct trace_event_call *call) |
f4b5ffcc JB |
635 | { |
636 | int ret = 0; | |
637 | int num; | |
638 | ||
3bbe84e9 | 639 | num = ((struct syscall_metadata *)call->data)->syscall_nr; |
f4b5ffcc JB |
640 | |
641 | mutex_lock(&syscall_trace_lock); | |
97d5a220 | 642 | if (!sys_perf_refcount_enter) |
38516ab5 | 643 | ret = register_trace_sys_enter(perf_syscall_enter, NULL); |
f4b5ffcc | 644 | if (ret) { |
d282b9c0 | 645 | pr_info("event trace: Could not activate syscall entry trace point"); |
f4b5ffcc | 646 | } else { |
97d5a220 FW |
647 | set_bit(num, enabled_perf_enter_syscalls); |
648 | sys_perf_refcount_enter++; | |
f4b5ffcc JB |
649 | } |
650 | mutex_unlock(&syscall_trace_lock); | |
651 | return ret; | |
652 | } | |
653 | ||
2425bcb9 | 654 | static void perf_sysenter_disable(struct trace_event_call *call) |
f4b5ffcc JB |
655 | { |
656 | int num; | |
657 | ||
3bbe84e9 | 658 | num = ((struct syscall_metadata *)call->data)->syscall_nr; |
f4b5ffcc JB |
659 | |
660 | mutex_lock(&syscall_trace_lock); | |
97d5a220 FW |
661 | sys_perf_refcount_enter--; |
662 | clear_bit(num, enabled_perf_enter_syscalls); | |
663 | if (!sys_perf_refcount_enter) | |
38516ab5 | 664 | unregister_trace_sys_enter(perf_syscall_enter, NULL); |
f4b5ffcc JB |
665 | mutex_unlock(&syscall_trace_lock); |
666 | } | |
667 | ||
e87c6bc3 YS |
668 | static int perf_call_bpf_exit(struct trace_event_call *call, struct pt_regs *regs, |
669 | struct syscall_trace_exit *rec) | |
670 | { | |
cf5f5cea YS |
671 | struct syscall_tp_t { |
672 | unsigned long long regs; | |
673 | unsigned long syscall_nr; | |
674 | unsigned long ret; | |
675 | } param; | |
676 | ||
677 | *(struct pt_regs **)¶m = regs; | |
678 | param.syscall_nr = rec->nr; | |
679 | param.ret = rec->ret; | |
e87c6bc3 | 680 | return trace_call_bpf(call, ¶m); |
cf5f5cea YS |
681 | } |
682 | ||
38516ab5 | 683 | static void perf_syscall_exit(void *ignore, struct pt_regs *regs, long ret) |
f4b5ffcc JB |
684 | { |
685 | struct syscall_metadata *sys_data; | |
20ab4425 | 686 | struct syscall_trace_exit *rec; |
1c024eca | 687 | struct hlist_head *head; |
e87c6bc3 | 688 | bool valid_prog_array; |
f4b5ffcc | 689 | int syscall_nr; |
4ed7c92d | 690 | int rctx; |
20ab4425 | 691 | int size; |
f4b5ffcc | 692 | |
f431b634 | 693 | syscall_nr = trace_get_syscall_nr(current, regs); |
086ba77a | 694 | if (syscall_nr < 0 || syscall_nr >= NR_syscalls) |
60916a93 | 695 | return; |
97d5a220 | 696 | if (!test_bit(syscall_nr, enabled_perf_exit_syscalls)) |
f4b5ffcc JB |
697 | return; |
698 | ||
699 | sys_data = syscall_nr_to_meta(syscall_nr); | |
700 | if (!sys_data) | |
701 | return; | |
702 | ||
421c7860 | 703 | head = this_cpu_ptr(sys_data->exit_event->perf_events); |
e87c6bc3 YS |
704 | valid_prog_array = bpf_prog_array_valid(sys_data->exit_event); |
705 | if (!valid_prog_array && hlist_empty(head)) | |
421c7860 ON |
706 | return; |
707 | ||
20ab4425 FW |
708 | /* We can probably do that at build time */ |
709 | size = ALIGN(sizeof(*rec) + sizeof(u32), sizeof(u64)); | |
710 | size -= sizeof(u32); | |
19007a67 | 711 | |
1e1dcd93 | 712 | rec = perf_trace_buf_alloc(size, NULL, &rctx); |
430ad5a6 XG |
713 | if (!rec) |
714 | return; | |
20ab4425 | 715 | |
20ab4425 FW |
716 | rec->nr = syscall_nr; |
717 | rec->ret = syscall_get_return_value(current, regs); | |
cf5f5cea | 718 | |
e87c6bc3 YS |
719 | if ((valid_prog_array && |
720 | !perf_call_bpf_exit(sys_data->exit_event, regs, rec)) || | |
cf5f5cea YS |
721 | hlist_empty(head)) { |
722 | perf_swevent_put_recursion_context(rctx); | |
723 | return; | |
724 | } | |
725 | ||
1e1dcd93 | 726 | perf_trace_buf_submit(rec, size, rctx, sys_data->exit_event->event.type, |
8fd0fbbe | 727 | 1, regs, head, NULL); |
f4b5ffcc JB |
728 | } |
729 | ||
2425bcb9 | 730 | static int perf_sysexit_enable(struct trace_event_call *call) |
f4b5ffcc JB |
731 | { |
732 | int ret = 0; | |
733 | int num; | |
734 | ||
3bbe84e9 | 735 | num = ((struct syscall_metadata *)call->data)->syscall_nr; |
f4b5ffcc JB |
736 | |
737 | mutex_lock(&syscall_trace_lock); | |
97d5a220 | 738 | if (!sys_perf_refcount_exit) |
38516ab5 | 739 | ret = register_trace_sys_exit(perf_syscall_exit, NULL); |
f4b5ffcc | 740 | if (ret) { |
d282b9c0 | 741 | pr_info("event trace: Could not activate syscall exit trace point"); |
f4b5ffcc | 742 | } else { |
97d5a220 FW |
743 | set_bit(num, enabled_perf_exit_syscalls); |
744 | sys_perf_refcount_exit++; | |
f4b5ffcc JB |
745 | } |
746 | mutex_unlock(&syscall_trace_lock); | |
747 | return ret; | |
748 | } | |
749 | ||
2425bcb9 | 750 | static void perf_sysexit_disable(struct trace_event_call *call) |
f4b5ffcc JB |
751 | { |
752 | int num; | |
753 | ||
3bbe84e9 | 754 | num = ((struct syscall_metadata *)call->data)->syscall_nr; |
f4b5ffcc JB |
755 | |
756 | mutex_lock(&syscall_trace_lock); | |
97d5a220 FW |
757 | sys_perf_refcount_exit--; |
758 | clear_bit(num, enabled_perf_exit_syscalls); | |
759 | if (!sys_perf_refcount_exit) | |
38516ab5 | 760 | unregister_trace_sys_exit(perf_syscall_exit, NULL); |
f4b5ffcc JB |
761 | mutex_unlock(&syscall_trace_lock); |
762 | } | |
763 | ||
07b139c8 | 764 | #endif /* CONFIG_PERF_EVENTS */ |
f4b5ffcc | 765 | |
2425bcb9 | 766 | static int syscall_enter_register(struct trace_event_call *event, |
ceec0b6f | 767 | enum trace_reg type, void *data) |
2239291a | 768 | { |
7f1d2f82 | 769 | struct trace_event_file *file = data; |
12ab74ee | 770 | |
2239291a SR |
771 | switch (type) { |
772 | case TRACE_REG_REGISTER: | |
12ab74ee | 773 | return reg_event_syscall_enter(file, event); |
2239291a | 774 | case TRACE_REG_UNREGISTER: |
12ab74ee | 775 | unreg_event_syscall_enter(file, event); |
2239291a SR |
776 | return 0; |
777 | ||
778 | #ifdef CONFIG_PERF_EVENTS | |
779 | case TRACE_REG_PERF_REGISTER: | |
780 | return perf_sysenter_enable(event); | |
781 | case TRACE_REG_PERF_UNREGISTER: | |
782 | perf_sysenter_disable(event); | |
783 | return 0; | |
ceec0b6f JO |
784 | case TRACE_REG_PERF_OPEN: |
785 | case TRACE_REG_PERF_CLOSE: | |
489c75c3 JO |
786 | case TRACE_REG_PERF_ADD: |
787 | case TRACE_REG_PERF_DEL: | |
ceec0b6f | 788 | return 0; |
2239291a SR |
789 | #endif |
790 | } | |
791 | return 0; | |
792 | } | |
793 | ||
2425bcb9 | 794 | static int syscall_exit_register(struct trace_event_call *event, |
ceec0b6f | 795 | enum trace_reg type, void *data) |
2239291a | 796 | { |
7f1d2f82 | 797 | struct trace_event_file *file = data; |
12ab74ee | 798 | |
2239291a SR |
799 | switch (type) { |
800 | case TRACE_REG_REGISTER: | |
12ab74ee | 801 | return reg_event_syscall_exit(file, event); |
2239291a | 802 | case TRACE_REG_UNREGISTER: |
12ab74ee | 803 | unreg_event_syscall_exit(file, event); |
2239291a SR |
804 | return 0; |
805 | ||
806 | #ifdef CONFIG_PERF_EVENTS | |
807 | case TRACE_REG_PERF_REGISTER: | |
808 | return perf_sysexit_enable(event); | |
809 | case TRACE_REG_PERF_UNREGISTER: | |
810 | perf_sysexit_disable(event); | |
811 | return 0; | |
ceec0b6f JO |
812 | case TRACE_REG_PERF_OPEN: |
813 | case TRACE_REG_PERF_CLOSE: | |
489c75c3 JO |
814 | case TRACE_REG_PERF_ADD: |
815 | case TRACE_REG_PERF_DEL: | |
ceec0b6f | 816 | return 0; |
2239291a SR |
817 | #endif |
818 | } | |
819 | return 0; | |
820 | } |