Commit | Line | Data |
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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> |
0e242208 | 10 | #include <linux/xarray.h> |
ee08c6ec FW |
11 | #include <asm/syscall.h> |
12 | ||
13 | #include "trace_output.h" | |
14 | #include "trace.h" | |
15 | ||
5be71b61 | 16 | static DEFINE_MUTEX(syscall_trace_lock); |
ee08c6ec | 17 | |
2425bcb9 | 18 | static int syscall_enter_register(struct trace_event_call *event, |
ceec0b6f | 19 | enum trace_reg type, void *data); |
2425bcb9 | 20 | static int syscall_exit_register(struct trace_event_call *event, |
ceec0b6f | 21 | enum trace_reg type, void *data); |
2239291a | 22 | |
2e33af02 | 23 | static struct list_head * |
2425bcb9 | 24 | syscall_get_enter_fields(struct trace_event_call *call) |
2e33af02 SR |
25 | { |
26 | struct syscall_metadata *entry = call->data; | |
27 | ||
28 | return &entry->enter_fields; | |
29 | } | |
30 | ||
3d56e331 SR |
31 | extern struct syscall_metadata *__start_syscalls_metadata[]; |
32 | extern struct syscall_metadata *__stop_syscalls_metadata[]; | |
c44fc770 | 33 | |
0e242208 | 34 | static DEFINE_XARRAY(syscalls_metadata_sparse); |
c44fc770 FW |
35 | static struct syscall_metadata **syscalls_metadata; |
36 | ||
b2d55496 IM |
37 | #ifndef ARCH_HAS_SYSCALL_MATCH_SYM_NAME |
38 | static inline bool arch_syscall_match_sym_name(const char *sym, const char *name) | |
39 | { | |
40 | /* | |
41 | * Only compare after the "sys" prefix. Archs that use | |
42 | * syscall wrappers may have syscalls symbols aliases prefixed | |
36a78e9e | 43 | * with ".SyS" or ".sys" instead of "sys", leading to an unwanted |
b2d55496 IM |
44 | * mismatch. |
45 | */ | |
46 | return !strcmp(sym + 3, name + 3); | |
47 | } | |
48 | #endif | |
49 | ||
f431b634 SR |
50 | #ifdef ARCH_TRACE_IGNORE_COMPAT_SYSCALLS |
51 | /* | |
52 | * Some architectures that allow for 32bit applications | |
53 | * to run on a 64bit kernel, do not map the syscalls for | |
54 | * the 32bit tasks the same as they do for 64bit tasks. | |
55 | * | |
56 | * *cough*x86*cough* | |
57 | * | |
58 | * In such a case, instead of reporting the wrong syscalls, | |
59 | * simply ignore them. | |
60 | * | |
61 | * For an arch to ignore the compat syscalls it needs to | |
62 | * define ARCH_TRACE_IGNORE_COMPAT_SYSCALLS as well as | |
63 | * define the function arch_trace_is_compat_syscall() to let | |
64 | * the tracing system know that it should ignore it. | |
65 | */ | |
66 | static int | |
67 | trace_get_syscall_nr(struct task_struct *task, struct pt_regs *regs) | |
68 | { | |
69 | if (unlikely(arch_trace_is_compat_syscall(regs))) | |
70 | return -1; | |
71 | ||
72 | return syscall_get_nr(task, regs); | |
73 | } | |
74 | #else | |
75 | static inline int | |
76 | trace_get_syscall_nr(struct task_struct *task, struct pt_regs *regs) | |
77 | { | |
78 | return syscall_get_nr(task, regs); | |
79 | } | |
80 | #endif /* ARCH_TRACE_IGNORE_COMPAT_SYSCALLS */ | |
81 | ||
3d56e331 SR |
82 | static __init struct syscall_metadata * |
83 | find_syscall_meta(unsigned long syscall) | |
c44fc770 | 84 | { |
3d56e331 SR |
85 | struct syscall_metadata **start; |
86 | struct syscall_metadata **stop; | |
c44fc770 FW |
87 | char str[KSYM_SYMBOL_LEN]; |
88 | ||
89 | ||
3d56e331 SR |
90 | start = __start_syscalls_metadata; |
91 | stop = __stop_syscalls_metadata; | |
c44fc770 FW |
92 | kallsyms_lookup(syscall, NULL, NULL, NULL, str); |
93 | ||
ae07f551 IM |
94 | if (arch_syscall_match_sym_name(str, "sys_ni_syscall")) |
95 | return NULL; | |
96 | ||
c44fc770 | 97 | for ( ; start < stop; start++) { |
b2d55496 | 98 | if ((*start)->name && arch_syscall_match_sym_name(str, (*start)->name)) |
3d56e331 | 99 | return *start; |
c44fc770 FW |
100 | } |
101 | return NULL; | |
102 | } | |
103 | ||
104 | static struct syscall_metadata *syscall_nr_to_meta(int nr) | |
105 | { | |
0e242208 HN |
106 | if (IS_ENABLED(CONFIG_HAVE_SPARSE_SYSCALL_NR)) |
107 | return xa_load(&syscalls_metadata_sparse, (unsigned long)nr); | |
108 | ||
c44fc770 FW |
109 | if (!syscalls_metadata || nr >= NR_syscalls || nr < 0) |
110 | return NULL; | |
111 | ||
112 | return syscalls_metadata[nr]; | |
113 | } | |
114 | ||
dbfeaa7a TZ |
115 | const char *get_syscall_name(int syscall) |
116 | { | |
117 | struct syscall_metadata *entry; | |
118 | ||
119 | entry = syscall_nr_to_meta(syscall); | |
120 | if (!entry) | |
121 | return NULL; | |
122 | ||
123 | return entry->name; | |
124 | } | |
125 | ||
6aea49cb | 126 | static enum print_line_t |
a9a57763 SR |
127 | print_syscall_enter(struct trace_iterator *iter, int flags, |
128 | struct trace_event *event) | |
bed1ffca | 129 | { |
983f938a | 130 | struct trace_array *tr = iter->tr; |
bed1ffca FW |
131 | struct trace_seq *s = &iter->seq; |
132 | struct trace_entry *ent = iter->ent; | |
133 | struct syscall_trace_enter *trace; | |
134 | struct syscall_metadata *entry; | |
183742f0 | 135 | int i, syscall; |
bed1ffca | 136 | |
64c12e04 | 137 | trace = (typeof(trace))ent; |
bed1ffca | 138 | syscall = trace->nr; |
bed1ffca | 139 | entry = syscall_nr_to_meta(syscall); |
64c12e04 | 140 | |
bed1ffca FW |
141 | if (!entry) |
142 | goto end; | |
143 | ||
32c0edae | 144 | if (entry->enter_event->event.type != ent->type) { |
64c12e04 JB |
145 | WARN_ON_ONCE(1); |
146 | goto end; | |
147 | } | |
148 | ||
183742f0 | 149 | trace_seq_printf(s, "%s(", entry->name); |
bed1ffca FW |
150 | |
151 | for (i = 0; i < entry->nb_args; i++) { | |
183742f0 SRRH |
152 | |
153 | if (trace_seq_has_overflowed(s)) | |
154 | goto end; | |
155 | ||
bed1ffca | 156 | /* parameter types */ |
cb1c45fb | 157 | if (tr && tr->trace_flags & TRACE_ITER_VERBOSE) |
183742f0 SRRH |
158 | trace_seq_printf(s, "%s ", entry->types[i]); |
159 | ||
bed1ffca | 160 | /* parameter values */ |
183742f0 SRRH |
161 | trace_seq_printf(s, "%s: %lx%s", entry->args[i], |
162 | trace->args[i], | |
163 | i == entry->nb_args - 1 ? "" : ", "); | |
bed1ffca FW |
164 | } |
165 | ||
183742f0 | 166 | trace_seq_putc(s, ')'); |
bed1ffca | 167 | end: |
183742f0 | 168 | trace_seq_putc(s, '\n'); |
4539f077 | 169 | |
183742f0 | 170 | return trace_handle_return(s); |
bed1ffca FW |
171 | } |
172 | ||
6aea49cb | 173 | static enum print_line_t |
a9a57763 SR |
174 | print_syscall_exit(struct trace_iterator *iter, int flags, |
175 | struct trace_event *event) | |
bed1ffca FW |
176 | { |
177 | struct trace_seq *s = &iter->seq; | |
178 | struct trace_entry *ent = iter->ent; | |
179 | struct syscall_trace_exit *trace; | |
180 | int syscall; | |
181 | struct syscall_metadata *entry; | |
bed1ffca | 182 | |
64c12e04 | 183 | trace = (typeof(trace))ent; |
bed1ffca | 184 | syscall = trace->nr; |
bed1ffca | 185 | entry = syscall_nr_to_meta(syscall); |
64c12e04 | 186 | |
bed1ffca | 187 | if (!entry) { |
146c3442 | 188 | trace_seq_putc(s, '\n'); |
183742f0 | 189 | goto out; |
bed1ffca FW |
190 | } |
191 | ||
32c0edae | 192 | if (entry->exit_event->event.type != ent->type) { |
64c12e04 JB |
193 | WARN_ON_ONCE(1); |
194 | return TRACE_TYPE_UNHANDLED; | |
195 | } | |
196 | ||
183742f0 | 197 | trace_seq_printf(s, "%s -> 0x%lx\n", entry->name, |
bed1ffca | 198 | trace->ret); |
bed1ffca | 199 | |
183742f0 SRRH |
200 | out: |
201 | return trace_handle_return(s); | |
bed1ffca FW |
202 | } |
203 | ||
e6971969 LZ |
204 | extern char *__bad_type_size(void); |
205 | ||
04ae87a5 PZ |
206 | #define SYSCALL_FIELD(_type, _name) { \ |
207 | .type = #_type, .name = #_name, \ | |
208 | .size = sizeof(_type), .align = __alignof__(_type), \ | |
209 | .is_signed = is_signed_type(_type), .filter_type = FILTER_OTHER } | |
e6971969 | 210 | |
3ddc77f6 LZ |
211 | static int __init |
212 | __set_enter_print_fmt(struct syscall_metadata *entry, char *buf, int len) | |
50307a45 LJ |
213 | { |
214 | int i; | |
215 | int pos = 0; | |
216 | ||
217 | /* When len=0, we just calculate the needed length */ | |
218 | #define LEN_OR_ZERO (len ? len - pos : 0) | |
219 | ||
220 | pos += snprintf(buf + pos, LEN_OR_ZERO, "\""); | |
221 | for (i = 0; i < entry->nb_args; i++) { | |
222 | pos += snprintf(buf + pos, LEN_OR_ZERO, "%s: 0x%%0%zulx%s", | |
223 | entry->args[i], sizeof(unsigned long), | |
224 | i == entry->nb_args - 1 ? "" : ", "); | |
225 | } | |
226 | pos += snprintf(buf + pos, LEN_OR_ZERO, "\""); | |
227 | ||
228 | for (i = 0; i < entry->nb_args; i++) { | |
229 | pos += snprintf(buf + pos, LEN_OR_ZERO, | |
230 | ", ((unsigned long)(REC->%s))", entry->args[i]); | |
231 | } | |
232 | ||
233 | #undef LEN_OR_ZERO | |
234 | ||
235 | /* return the length of print_fmt */ | |
236 | return pos; | |
237 | } | |
238 | ||
2425bcb9 | 239 | static int __init set_syscall_print_fmt(struct trace_event_call *call) |
50307a45 LJ |
240 | { |
241 | char *print_fmt; | |
242 | int len; | |
243 | struct syscall_metadata *entry = call->data; | |
244 | ||
245 | if (entry->enter_event != call) { | |
246 | call->print_fmt = "\"0x%lx\", REC->ret"; | |
247 | return 0; | |
248 | } | |
249 | ||
250 | /* First: called with 0 length to calculate the needed length */ | |
251 | len = __set_enter_print_fmt(entry, NULL, 0); | |
252 | ||
253 | print_fmt = kmalloc(len + 1, GFP_KERNEL); | |
254 | if (!print_fmt) | |
255 | return -ENOMEM; | |
256 | ||
257 | /* Second: actually write the @print_fmt */ | |
258 | __set_enter_print_fmt(entry, print_fmt, len + 1); | |
259 | call->print_fmt = print_fmt; | |
260 | ||
261 | return 0; | |
262 | } | |
263 | ||
2425bcb9 | 264 | static void __init free_syscall_print_fmt(struct trace_event_call *call) |
50307a45 LJ |
265 | { |
266 | struct syscall_metadata *entry = call->data; | |
267 | ||
268 | if (entry->enter_event == call) | |
269 | kfree(call->print_fmt); | |
270 | } | |
271 | ||
2425bcb9 | 272 | static int __init syscall_enter_define_fields(struct trace_event_call *call) |
540b7b8d LZ |
273 | { |
274 | struct syscall_trace_enter trace; | |
31c16b13 | 275 | struct syscall_metadata *meta = call->data; |
540b7b8d | 276 | int offset = offsetof(typeof(trace), args); |
31537cf8 SRV |
277 | int ret = 0; |
278 | int i; | |
0f1ef51d | 279 | |
540b7b8d | 280 | for (i = 0; i < meta->nb_args; i++) { |
aeaeae11 FW |
281 | ret = trace_define_field(call, meta->types[i], |
282 | meta->args[i], offset, | |
43b51ead LZ |
283 | sizeof(unsigned long), 0, |
284 | FILTER_OTHER); | |
04ae87a5 PZ |
285 | if (ret) |
286 | break; | |
540b7b8d LZ |
287 | offset += sizeof(unsigned long); |
288 | } | |
289 | ||
290 | return ret; | |
291 | } | |
292 | ||
12ab74ee | 293 | static void ftrace_syscall_enter(void *data, struct pt_regs *regs, long id) |
ee08c6ec | 294 | { |
12ab74ee | 295 | struct trace_array *tr = data; |
7f1d2f82 | 296 | struct trace_event_file *trace_file; |
bed1ffca FW |
297 | struct syscall_trace_enter *entry; |
298 | struct syscall_metadata *sys_data; | |
cb1c45fb | 299 | struct trace_event_buffer fbuffer; |
d08e4113 | 300 | unsigned long args[6]; |
ee08c6ec | 301 | int syscall_nr; |
f431b634 | 302 | int size; |
ee08c6ec | 303 | |
f431b634 | 304 | syscall_nr = trace_get_syscall_nr(current, regs); |
086ba77a | 305 | if (syscall_nr < 0 || syscall_nr >= NR_syscalls) |
cd0980fc | 306 | return; |
d562aff9 TZ |
307 | |
308 | /* Here we're inside tp handler's rcu_read_lock_sched (__DO_TRACE) */ | |
7f1d2f82 SRRH |
309 | trace_file = rcu_dereference_sched(tr->enter_syscall_files[syscall_nr]); |
310 | if (!trace_file) | |
d562aff9 TZ |
311 | return; |
312 | ||
09a5059a | 313 | if (trace_trigger_soft_disabled(trace_file)) |
13a1e4ae | 314 | return; |
ee08c6ec | 315 | |
bed1ffca FW |
316 | sys_data = syscall_nr_to_meta(syscall_nr); |
317 | if (!sys_data) | |
318 | return; | |
319 | ||
320 | size = sizeof(*entry) + sizeof(unsigned long) * sys_data->nb_args; | |
321 | ||
cb1c45fb JX |
322 | entry = trace_event_buffer_reserve(&fbuffer, trace_file, size); |
323 | if (!entry) | |
bed1ffca FW |
324 | return; |
325 | ||
cb1c45fb | 326 | entry = ring_buffer_event_data(fbuffer.event); |
bed1ffca | 327 | entry->nr = syscall_nr; |
b35f549d | 328 | syscall_get_arguments(current, regs, args); |
d08e4113 | 329 | memcpy(entry->args, args, sizeof(unsigned long) * sys_data->nb_args); |
bed1ffca | 330 | |
cb1c45fb | 331 | trace_event_buffer_commit(&fbuffer); |
ee08c6ec FW |
332 | } |
333 | ||
12ab74ee | 334 | static void ftrace_syscall_exit(void *data, struct pt_regs *regs, long ret) |
ee08c6ec | 335 | { |
12ab74ee | 336 | struct trace_array *tr = data; |
7f1d2f82 | 337 | struct trace_event_file *trace_file; |
bed1ffca FW |
338 | struct syscall_trace_exit *entry; |
339 | struct syscall_metadata *sys_data; | |
cb1c45fb | 340 | struct trace_event_buffer fbuffer; |
ee08c6ec FW |
341 | int syscall_nr; |
342 | ||
f431b634 | 343 | syscall_nr = trace_get_syscall_nr(current, regs); |
086ba77a | 344 | if (syscall_nr < 0 || syscall_nr >= NR_syscalls) |
cd0980fc | 345 | return; |
d562aff9 TZ |
346 | |
347 | /* Here we're inside tp handler's rcu_read_lock_sched (__DO_TRACE()) */ | |
7f1d2f82 SRRH |
348 | trace_file = rcu_dereference_sched(tr->exit_syscall_files[syscall_nr]); |
349 | if (!trace_file) | |
d562aff9 TZ |
350 | return; |
351 | ||
09a5059a | 352 | if (trace_trigger_soft_disabled(trace_file)) |
13a1e4ae | 353 | return; |
ee08c6ec | 354 | |
bed1ffca FW |
355 | sys_data = syscall_nr_to_meta(syscall_nr); |
356 | if (!sys_data) | |
357 | return; | |
358 | ||
cb1c45fb JX |
359 | entry = trace_event_buffer_reserve(&fbuffer, trace_file, sizeof(*entry)); |
360 | if (!entry) | |
bed1ffca FW |
361 | return; |
362 | ||
cb1c45fb | 363 | entry = ring_buffer_event_data(fbuffer.event); |
bed1ffca FW |
364 | entry->nr = syscall_nr; |
365 | entry->ret = syscall_get_return_value(current, regs); | |
366 | ||
cb1c45fb | 367 | trace_event_buffer_commit(&fbuffer); |
ee08c6ec FW |
368 | } |
369 | ||
7f1d2f82 | 370 | static int reg_event_syscall_enter(struct trace_event_file *file, |
2425bcb9 | 371 | struct trace_event_call *call) |
ee08c6ec | 372 | { |
12ab74ee | 373 | struct trace_array *tr = file->tr; |
fb34a08c JB |
374 | int ret = 0; |
375 | int num; | |
fb34a08c | 376 | |
c252f657 | 377 | num = ((struct syscall_metadata *)call->data)->syscall_nr; |
3773b389 | 378 | if (WARN_ON_ONCE(num < 0 || num >= NR_syscalls)) |
fb34a08c JB |
379 | return -ENOSYS; |
380 | mutex_lock(&syscall_trace_lock); | |
12ab74ee SR |
381 | if (!tr->sys_refcount_enter) |
382 | ret = register_trace_sys_enter(ftrace_syscall_enter, tr); | |
3b8e4273 | 383 | if (!ret) { |
d562aff9 | 384 | rcu_assign_pointer(tr->enter_syscall_files[num], file); |
12ab74ee | 385 | tr->sys_refcount_enter++; |
fb34a08c JB |
386 | } |
387 | mutex_unlock(&syscall_trace_lock); | |
388 | return ret; | |
ee08c6ec FW |
389 | } |
390 | ||
7f1d2f82 | 391 | static void unreg_event_syscall_enter(struct trace_event_file *file, |
2425bcb9 | 392 | struct trace_event_call *call) |
ee08c6ec | 393 | { |
12ab74ee | 394 | struct trace_array *tr = file->tr; |
fb34a08c | 395 | int num; |
ee08c6ec | 396 | |
c252f657 | 397 | num = ((struct syscall_metadata *)call->data)->syscall_nr; |
3773b389 | 398 | if (WARN_ON_ONCE(num < 0 || num >= NR_syscalls)) |
fb34a08c JB |
399 | return; |
400 | mutex_lock(&syscall_trace_lock); | |
12ab74ee | 401 | tr->sys_refcount_enter--; |
fb5a613b | 402 | RCU_INIT_POINTER(tr->enter_syscall_files[num], NULL); |
12ab74ee SR |
403 | if (!tr->sys_refcount_enter) |
404 | unregister_trace_sys_enter(ftrace_syscall_enter, tr); | |
fb34a08c JB |
405 | mutex_unlock(&syscall_trace_lock); |
406 | } | |
ee08c6ec | 407 | |
7f1d2f82 | 408 | static int reg_event_syscall_exit(struct trace_event_file *file, |
2425bcb9 | 409 | struct trace_event_call *call) |
ee08c6ec | 410 | { |
12ab74ee | 411 | struct trace_array *tr = file->tr; |
fb34a08c JB |
412 | int ret = 0; |
413 | int num; | |
fb34a08c | 414 | |
c252f657 | 415 | num = ((struct syscall_metadata *)call->data)->syscall_nr; |
3773b389 | 416 | if (WARN_ON_ONCE(num < 0 || num >= NR_syscalls)) |
fb34a08c JB |
417 | return -ENOSYS; |
418 | mutex_lock(&syscall_trace_lock); | |
12ab74ee SR |
419 | if (!tr->sys_refcount_exit) |
420 | ret = register_trace_sys_exit(ftrace_syscall_exit, tr); | |
3b8e4273 | 421 | if (!ret) { |
d562aff9 | 422 | rcu_assign_pointer(tr->exit_syscall_files[num], file); |
12ab74ee | 423 | tr->sys_refcount_exit++; |
ee08c6ec | 424 | } |
fb34a08c JB |
425 | mutex_unlock(&syscall_trace_lock); |
426 | return ret; | |
427 | } | |
ee08c6ec | 428 | |
7f1d2f82 | 429 | static void unreg_event_syscall_exit(struct trace_event_file *file, |
2425bcb9 | 430 | struct trace_event_call *call) |
fb34a08c | 431 | { |
12ab74ee | 432 | struct trace_array *tr = file->tr; |
fb34a08c | 433 | int num; |
ee08c6ec | 434 | |
c252f657 | 435 | num = ((struct syscall_metadata *)call->data)->syscall_nr; |
3773b389 | 436 | if (WARN_ON_ONCE(num < 0 || num >= NR_syscalls)) |
fb34a08c JB |
437 | return; |
438 | mutex_lock(&syscall_trace_lock); | |
12ab74ee | 439 | tr->sys_refcount_exit--; |
fb5a613b | 440 | RCU_INIT_POINTER(tr->exit_syscall_files[num], NULL); |
12ab74ee SR |
441 | if (!tr->sys_refcount_exit) |
442 | unregister_trace_sys_exit(ftrace_syscall_exit, tr); | |
fb34a08c | 443 | mutex_unlock(&syscall_trace_lock); |
ee08c6ec | 444 | } |
fb34a08c | 445 | |
2425bcb9 | 446 | static int __init init_syscall_trace(struct trace_event_call *call) |
a1301da0 LJ |
447 | { |
448 | int id; | |
ba976970 IM |
449 | int num; |
450 | ||
451 | num = ((struct syscall_metadata *)call->data)->syscall_nr; | |
452 | if (num < 0 || num >= NR_syscalls) { | |
453 | pr_debug("syscall %s metadata not mapped, disabling ftrace event\n", | |
454 | ((struct syscall_metadata *)call->data)->name); | |
455 | return -ENOSYS; | |
456 | } | |
a1301da0 | 457 | |
50307a45 LJ |
458 | if (set_syscall_print_fmt(call) < 0) |
459 | return -ENOMEM; | |
460 | ||
c7ef3a90 SR |
461 | id = trace_event_raw_init(call); |
462 | ||
463 | if (id < 0) { | |
50307a45 | 464 | free_syscall_print_fmt(call); |
c7ef3a90 | 465 | return id; |
50307a45 | 466 | } |
c7ef3a90 SR |
467 | |
468 | return id; | |
a1301da0 LJ |
469 | } |
470 | ||
04ae87a5 PZ |
471 | static struct trace_event_fields __refdata syscall_enter_fields_array[] = { |
472 | SYSCALL_FIELD(int, __syscall_nr), | |
473 | { .type = TRACE_FUNCTION_TYPE, | |
474 | .define_fields = syscall_enter_define_fields }, | |
475 | {} | |
476 | }; | |
477 | ||
6f86ab9f VN |
478 | struct trace_event_functions enter_syscall_print_funcs = { |
479 | .trace = print_syscall_enter, | |
480 | }; | |
481 | ||
482 | struct trace_event_functions exit_syscall_print_funcs = { | |
483 | .trace = print_syscall_exit, | |
484 | }; | |
485 | ||
2425bcb9 | 486 | struct trace_event_class __refdata event_class_syscall_enter = { |
6f86ab9f VN |
487 | .system = "syscalls", |
488 | .reg = syscall_enter_register, | |
04ae87a5 | 489 | .fields_array = syscall_enter_fields_array, |
6f86ab9f VN |
490 | .get_fields = syscall_get_enter_fields, |
491 | .raw_init = init_syscall_trace, | |
492 | }; | |
493 | ||
2425bcb9 | 494 | struct trace_event_class __refdata event_class_syscall_exit = { |
6f86ab9f VN |
495 | .system = "syscalls", |
496 | .reg = syscall_exit_register, | |
04ae87a5 PZ |
497 | .fields_array = (struct trace_event_fields[]){ |
498 | SYSCALL_FIELD(int, __syscall_nr), | |
499 | SYSCALL_FIELD(long, ret), | |
500 | {} | |
501 | }, | |
6f86ab9f VN |
502 | .fields = LIST_HEAD_INIT(event_class_syscall_exit.fields), |
503 | .raw_init = init_syscall_trace, | |
504 | }; | |
505 | ||
c763ba06 | 506 | unsigned long __init __weak arch_syscall_addr(int nr) |
e7b8e675 MF |
507 | { |
508 | return (unsigned long)sys_call_table[nr]; | |
509 | } | |
510 | ||
5f893b26 | 511 | void __init init_ftrace_syscalls(void) |
c44fc770 FW |
512 | { |
513 | struct syscall_metadata *meta; | |
514 | unsigned long addr; | |
515 | int i; | |
0e242208 HN |
516 | void *ret; |
517 | ||
518 | if (!IS_ENABLED(CONFIG_HAVE_SPARSE_SYSCALL_NR)) { | |
519 | syscalls_metadata = kcalloc(NR_syscalls, | |
520 | sizeof(*syscalls_metadata), | |
521 | GFP_KERNEL); | |
522 | if (!syscalls_metadata) { | |
523 | WARN_ON(1); | |
524 | return; | |
525 | } | |
c44fc770 FW |
526 | } |
527 | ||
528 | for (i = 0; i < NR_syscalls; i++) { | |
529 | addr = arch_syscall_addr(i); | |
530 | meta = find_syscall_meta(addr); | |
c252f657 LJ |
531 | if (!meta) |
532 | continue; | |
533 | ||
534 | meta->syscall_nr = i; | |
0e242208 HN |
535 | |
536 | if (!IS_ENABLED(CONFIG_HAVE_SPARSE_SYSCALL_NR)) { | |
537 | syscalls_metadata[i] = meta; | |
538 | } else { | |
539 | ret = xa_store(&syscalls_metadata_sparse, i, meta, | |
540 | GFP_KERNEL); | |
541 | WARN(xa_is_err(ret), | |
542 | "Syscall memory allocation failed\n"); | |
543 | } | |
544 | ||
c44fc770 | 545 | } |
c44fc770 | 546 | } |
c44fc770 | 547 | |
07b139c8 | 548 | #ifdef CONFIG_PERF_EVENTS |
19007a67 | 549 | |
97d5a220 FW |
550 | static DECLARE_BITMAP(enabled_perf_enter_syscalls, NR_syscalls); |
551 | static DECLARE_BITMAP(enabled_perf_exit_syscalls, NR_syscalls); | |
552 | static int sys_perf_refcount_enter; | |
553 | static int sys_perf_refcount_exit; | |
f4b5ffcc | 554 | |
e87c6bc3 YS |
555 | static int perf_call_bpf_enter(struct trace_event_call *call, struct pt_regs *regs, |
556 | struct syscall_metadata *sys_data, | |
557 | struct syscall_trace_enter *rec) | |
558 | { | |
cf5f5cea YS |
559 | struct syscall_tp_t { |
560 | unsigned long long regs; | |
561 | unsigned long syscall_nr; | |
609320c8 | 562 | unsigned long args[SYSCALL_DEFINE_MAXARGS]; |
cf5f5cea YS |
563 | } param; |
564 | int i; | |
565 | ||
566 | *(struct pt_regs **)¶m = regs; | |
567 | param.syscall_nr = rec->nr; | |
568 | for (i = 0; i < sys_data->nb_args; i++) | |
569 | param.args[i] = rec->args[i]; | |
e87c6bc3 | 570 | return trace_call_bpf(call, ¶m); |
cf5f5cea YS |
571 | } |
572 | ||
38516ab5 | 573 | static void perf_syscall_enter(void *ignore, struct pt_regs *regs, long id) |
f4b5ffcc JB |
574 | { |
575 | struct syscall_metadata *sys_data; | |
20ab4425 | 576 | struct syscall_trace_enter *rec; |
1c024eca | 577 | struct hlist_head *head; |
d08e4113 | 578 | unsigned long args[6]; |
e87c6bc3 | 579 | bool valid_prog_array; |
f4b5ffcc | 580 | int syscall_nr; |
4ed7c92d | 581 | int rctx; |
19007a67 | 582 | int size; |
f4b5ffcc | 583 | |
f431b634 | 584 | syscall_nr = trace_get_syscall_nr(current, regs); |
086ba77a | 585 | if (syscall_nr < 0 || syscall_nr >= NR_syscalls) |
60916a93 | 586 | return; |
97d5a220 | 587 | if (!test_bit(syscall_nr, enabled_perf_enter_syscalls)) |
f4b5ffcc JB |
588 | return; |
589 | ||
590 | sys_data = syscall_nr_to_meta(syscall_nr); | |
591 | if (!sys_data) | |
592 | return; | |
593 | ||
421c7860 | 594 | head = this_cpu_ptr(sys_data->enter_event->perf_events); |
e87c6bc3 YS |
595 | valid_prog_array = bpf_prog_array_valid(sys_data->enter_event); |
596 | if (!valid_prog_array && hlist_empty(head)) | |
421c7860 ON |
597 | return; |
598 | ||
19007a67 FW |
599 | /* get the size after alignment with the u32 buffer size field */ |
600 | size = sizeof(unsigned long) * sys_data->nb_args + sizeof(*rec); | |
601 | size = ALIGN(size + sizeof(u32), sizeof(u64)); | |
602 | size -= sizeof(u32); | |
603 | ||
1e1dcd93 | 604 | rec = perf_trace_buf_alloc(size, NULL, &rctx); |
430ad5a6 XG |
605 | if (!rec) |
606 | return; | |
20ab4425 | 607 | |
20ab4425 | 608 | rec->nr = syscall_nr; |
b35f549d | 609 | syscall_get_arguments(current, regs, args); |
d08e4113 | 610 | memcpy(&rec->args, args, sizeof(unsigned long) * sys_data->nb_args); |
cf5f5cea | 611 | |
e87c6bc3 YS |
612 | if ((valid_prog_array && |
613 | !perf_call_bpf_enter(sys_data->enter_event, regs, sys_data, rec)) || | |
cf5f5cea YS |
614 | hlist_empty(head)) { |
615 | perf_swevent_put_recursion_context(rctx); | |
616 | return; | |
617 | } | |
618 | ||
1e1dcd93 AS |
619 | perf_trace_buf_submit(rec, size, rctx, |
620 | sys_data->enter_event->event.type, 1, regs, | |
8fd0fbbe | 621 | head, NULL); |
f4b5ffcc JB |
622 | } |
623 | ||
2425bcb9 | 624 | static int perf_sysenter_enable(struct trace_event_call *call) |
f4b5ffcc JB |
625 | { |
626 | int ret = 0; | |
627 | int num; | |
628 | ||
3bbe84e9 | 629 | num = ((struct syscall_metadata *)call->data)->syscall_nr; |
f4b5ffcc JB |
630 | |
631 | mutex_lock(&syscall_trace_lock); | |
97d5a220 | 632 | if (!sys_perf_refcount_enter) |
38516ab5 | 633 | ret = register_trace_sys_enter(perf_syscall_enter, NULL); |
f4b5ffcc | 634 | if (ret) { |
d282b9c0 | 635 | pr_info("event trace: Could not activate syscall entry trace point"); |
f4b5ffcc | 636 | } else { |
97d5a220 FW |
637 | set_bit(num, enabled_perf_enter_syscalls); |
638 | sys_perf_refcount_enter++; | |
f4b5ffcc JB |
639 | } |
640 | mutex_unlock(&syscall_trace_lock); | |
641 | return ret; | |
642 | } | |
643 | ||
2425bcb9 | 644 | static void perf_sysenter_disable(struct trace_event_call *call) |
f4b5ffcc JB |
645 | { |
646 | int num; | |
647 | ||
3bbe84e9 | 648 | num = ((struct syscall_metadata *)call->data)->syscall_nr; |
f4b5ffcc JB |
649 | |
650 | mutex_lock(&syscall_trace_lock); | |
97d5a220 FW |
651 | sys_perf_refcount_enter--; |
652 | clear_bit(num, enabled_perf_enter_syscalls); | |
653 | if (!sys_perf_refcount_enter) | |
38516ab5 | 654 | unregister_trace_sys_enter(perf_syscall_enter, NULL); |
f4b5ffcc JB |
655 | mutex_unlock(&syscall_trace_lock); |
656 | } | |
657 | ||
e87c6bc3 YS |
658 | static int perf_call_bpf_exit(struct trace_event_call *call, struct pt_regs *regs, |
659 | struct syscall_trace_exit *rec) | |
660 | { | |
cf5f5cea YS |
661 | struct syscall_tp_t { |
662 | unsigned long long regs; | |
663 | unsigned long syscall_nr; | |
664 | unsigned long ret; | |
665 | } param; | |
666 | ||
667 | *(struct pt_regs **)¶m = regs; | |
668 | param.syscall_nr = rec->nr; | |
669 | param.ret = rec->ret; | |
e87c6bc3 | 670 | return trace_call_bpf(call, ¶m); |
cf5f5cea YS |
671 | } |
672 | ||
38516ab5 | 673 | static void perf_syscall_exit(void *ignore, struct pt_regs *regs, long ret) |
f4b5ffcc JB |
674 | { |
675 | struct syscall_metadata *sys_data; | |
20ab4425 | 676 | struct syscall_trace_exit *rec; |
1c024eca | 677 | struct hlist_head *head; |
e87c6bc3 | 678 | bool valid_prog_array; |
f4b5ffcc | 679 | int syscall_nr; |
4ed7c92d | 680 | int rctx; |
20ab4425 | 681 | int size; |
f4b5ffcc | 682 | |
f431b634 | 683 | syscall_nr = trace_get_syscall_nr(current, regs); |
086ba77a | 684 | if (syscall_nr < 0 || syscall_nr >= NR_syscalls) |
60916a93 | 685 | return; |
97d5a220 | 686 | if (!test_bit(syscall_nr, enabled_perf_exit_syscalls)) |
f4b5ffcc JB |
687 | return; |
688 | ||
689 | sys_data = syscall_nr_to_meta(syscall_nr); | |
690 | if (!sys_data) | |
691 | return; | |
692 | ||
421c7860 | 693 | head = this_cpu_ptr(sys_data->exit_event->perf_events); |
e87c6bc3 YS |
694 | valid_prog_array = bpf_prog_array_valid(sys_data->exit_event); |
695 | if (!valid_prog_array && hlist_empty(head)) | |
421c7860 ON |
696 | return; |
697 | ||
20ab4425 FW |
698 | /* We can probably do that at build time */ |
699 | size = ALIGN(sizeof(*rec) + sizeof(u32), sizeof(u64)); | |
700 | size -= sizeof(u32); | |
19007a67 | 701 | |
1e1dcd93 | 702 | rec = perf_trace_buf_alloc(size, NULL, &rctx); |
430ad5a6 XG |
703 | if (!rec) |
704 | return; | |
20ab4425 | 705 | |
20ab4425 FW |
706 | rec->nr = syscall_nr; |
707 | rec->ret = syscall_get_return_value(current, regs); | |
cf5f5cea | 708 | |
e87c6bc3 YS |
709 | if ((valid_prog_array && |
710 | !perf_call_bpf_exit(sys_data->exit_event, regs, rec)) || | |
cf5f5cea YS |
711 | hlist_empty(head)) { |
712 | perf_swevent_put_recursion_context(rctx); | |
713 | return; | |
714 | } | |
715 | ||
1e1dcd93 | 716 | perf_trace_buf_submit(rec, size, rctx, sys_data->exit_event->event.type, |
8fd0fbbe | 717 | 1, regs, head, NULL); |
f4b5ffcc JB |
718 | } |
719 | ||
2425bcb9 | 720 | static int perf_sysexit_enable(struct trace_event_call *call) |
f4b5ffcc JB |
721 | { |
722 | int ret = 0; | |
723 | int num; | |
724 | ||
3bbe84e9 | 725 | num = ((struct syscall_metadata *)call->data)->syscall_nr; |
f4b5ffcc JB |
726 | |
727 | mutex_lock(&syscall_trace_lock); | |
97d5a220 | 728 | if (!sys_perf_refcount_exit) |
38516ab5 | 729 | ret = register_trace_sys_exit(perf_syscall_exit, NULL); |
f4b5ffcc | 730 | if (ret) { |
d282b9c0 | 731 | pr_info("event trace: Could not activate syscall exit trace point"); |
f4b5ffcc | 732 | } else { |
97d5a220 FW |
733 | set_bit(num, enabled_perf_exit_syscalls); |
734 | sys_perf_refcount_exit++; | |
f4b5ffcc JB |
735 | } |
736 | mutex_unlock(&syscall_trace_lock); | |
737 | return ret; | |
738 | } | |
739 | ||
2425bcb9 | 740 | static void perf_sysexit_disable(struct trace_event_call *call) |
f4b5ffcc JB |
741 | { |
742 | int num; | |
743 | ||
3bbe84e9 | 744 | num = ((struct syscall_metadata *)call->data)->syscall_nr; |
f4b5ffcc JB |
745 | |
746 | mutex_lock(&syscall_trace_lock); | |
97d5a220 FW |
747 | sys_perf_refcount_exit--; |
748 | clear_bit(num, enabled_perf_exit_syscalls); | |
749 | if (!sys_perf_refcount_exit) | |
38516ab5 | 750 | unregister_trace_sys_exit(perf_syscall_exit, NULL); |
f4b5ffcc JB |
751 | mutex_unlock(&syscall_trace_lock); |
752 | } | |
753 | ||
07b139c8 | 754 | #endif /* CONFIG_PERF_EVENTS */ |
f4b5ffcc | 755 | |
2425bcb9 | 756 | static int syscall_enter_register(struct trace_event_call *event, |
ceec0b6f | 757 | enum trace_reg type, void *data) |
2239291a | 758 | { |
7f1d2f82 | 759 | struct trace_event_file *file = data; |
12ab74ee | 760 | |
2239291a SR |
761 | switch (type) { |
762 | case TRACE_REG_REGISTER: | |
12ab74ee | 763 | return reg_event_syscall_enter(file, event); |
2239291a | 764 | case TRACE_REG_UNREGISTER: |
12ab74ee | 765 | unreg_event_syscall_enter(file, event); |
2239291a SR |
766 | return 0; |
767 | ||
768 | #ifdef CONFIG_PERF_EVENTS | |
769 | case TRACE_REG_PERF_REGISTER: | |
770 | return perf_sysenter_enable(event); | |
771 | case TRACE_REG_PERF_UNREGISTER: | |
772 | perf_sysenter_disable(event); | |
773 | return 0; | |
ceec0b6f JO |
774 | case TRACE_REG_PERF_OPEN: |
775 | case TRACE_REG_PERF_CLOSE: | |
489c75c3 JO |
776 | case TRACE_REG_PERF_ADD: |
777 | case TRACE_REG_PERF_DEL: | |
ceec0b6f | 778 | return 0; |
2239291a SR |
779 | #endif |
780 | } | |
781 | return 0; | |
782 | } | |
783 | ||
2425bcb9 | 784 | static int syscall_exit_register(struct trace_event_call *event, |
ceec0b6f | 785 | enum trace_reg type, void *data) |
2239291a | 786 | { |
7f1d2f82 | 787 | struct trace_event_file *file = data; |
12ab74ee | 788 | |
2239291a SR |
789 | switch (type) { |
790 | case TRACE_REG_REGISTER: | |
12ab74ee | 791 | return reg_event_syscall_exit(file, event); |
2239291a | 792 | case TRACE_REG_UNREGISTER: |
12ab74ee | 793 | unreg_event_syscall_exit(file, event); |
2239291a SR |
794 | return 0; |
795 | ||
796 | #ifdef CONFIG_PERF_EVENTS | |
797 | case TRACE_REG_PERF_REGISTER: | |
798 | return perf_sysexit_enable(event); | |
799 | case TRACE_REG_PERF_UNREGISTER: | |
800 | perf_sysexit_disable(event); | |
801 | return 0; | |
ceec0b6f JO |
802 | case TRACE_REG_PERF_OPEN: |
803 | case TRACE_REG_PERF_CLOSE: | |
489c75c3 JO |
804 | case TRACE_REG_PERF_ADD: |
805 | case TRACE_REG_PERF_DEL: | |
ceec0b6f | 806 | return 0; |
2239291a SR |
807 | #endif |
808 | } | |
809 | return 0; | |
810 | } |