Commit | Line | Data |
---|---|---|
47788c58 | 1 | #include <trace/syscall.h> |
1c569f02 | 2 | #include <trace/events/syscalls.h> |
f431b634 | 3 | #include <linux/syscalls.h> |
5a0e3ad6 | 4 | #include <linux/slab.h> |
ee08c6ec | 5 | #include <linux/kernel.h> |
56d82e00 | 6 | #include <linux/module.h> /* for MODULE_NAME_LEN via KSYM_SYMBOL_LEN */ |
fb34a08c | 7 | #include <linux/ftrace.h> |
cdd6c482 | 8 | #include <linux/perf_event.h> |
ee08c6ec FW |
9 | #include <asm/syscall.h> |
10 | ||
11 | #include "trace_output.h" | |
12 | #include "trace.h" | |
13 | ||
5be71b61 | 14 | static DEFINE_MUTEX(syscall_trace_lock); |
ee08c6ec | 15 | |
2239291a | 16 | static int syscall_enter_register(struct ftrace_event_call *event, |
ceec0b6f | 17 | enum trace_reg type, void *data); |
2239291a | 18 | static int syscall_exit_register(struct ftrace_event_call *event, |
ceec0b6f | 19 | enum trace_reg type, void *data); |
2239291a | 20 | |
2e33af02 SR |
21 | static struct list_head * |
22 | syscall_get_enter_fields(struct ftrace_event_call *call) | |
23 | { | |
24 | struct syscall_metadata *entry = call->data; | |
25 | ||
26 | return &entry->enter_fields; | |
27 | } | |
28 | ||
3d56e331 SR |
29 | extern struct syscall_metadata *__start_syscalls_metadata[]; |
30 | extern struct syscall_metadata *__stop_syscalls_metadata[]; | |
c44fc770 FW |
31 | |
32 | static struct syscall_metadata **syscalls_metadata; | |
33 | ||
b2d55496 IM |
34 | #ifndef ARCH_HAS_SYSCALL_MATCH_SYM_NAME |
35 | static inline bool arch_syscall_match_sym_name(const char *sym, const char *name) | |
36 | { | |
37 | /* | |
38 | * Only compare after the "sys" prefix. Archs that use | |
39 | * syscall wrappers may have syscalls symbols aliases prefixed | |
36a78e9e | 40 | * with ".SyS" or ".sys" instead of "sys", leading to an unwanted |
b2d55496 IM |
41 | * mismatch. |
42 | */ | |
43 | return !strcmp(sym + 3, name + 3); | |
44 | } | |
45 | #endif | |
46 | ||
f431b634 SR |
47 | #ifdef ARCH_TRACE_IGNORE_COMPAT_SYSCALLS |
48 | /* | |
49 | * Some architectures that allow for 32bit applications | |
50 | * to run on a 64bit kernel, do not map the syscalls for | |
51 | * the 32bit tasks the same as they do for 64bit tasks. | |
52 | * | |
53 | * *cough*x86*cough* | |
54 | * | |
55 | * In such a case, instead of reporting the wrong syscalls, | |
56 | * simply ignore them. | |
57 | * | |
58 | * For an arch to ignore the compat syscalls it needs to | |
59 | * define ARCH_TRACE_IGNORE_COMPAT_SYSCALLS as well as | |
60 | * define the function arch_trace_is_compat_syscall() to let | |
61 | * the tracing system know that it should ignore it. | |
62 | */ | |
63 | static int | |
64 | trace_get_syscall_nr(struct task_struct *task, struct pt_regs *regs) | |
65 | { | |
66 | if (unlikely(arch_trace_is_compat_syscall(regs))) | |
67 | return -1; | |
68 | ||
69 | return syscall_get_nr(task, regs); | |
70 | } | |
71 | #else | |
72 | static inline int | |
73 | trace_get_syscall_nr(struct task_struct *task, struct pt_regs *regs) | |
74 | { | |
75 | return syscall_get_nr(task, regs); | |
76 | } | |
77 | #endif /* ARCH_TRACE_IGNORE_COMPAT_SYSCALLS */ | |
78 | ||
3d56e331 SR |
79 | static __init struct syscall_metadata * |
80 | find_syscall_meta(unsigned long syscall) | |
c44fc770 | 81 | { |
3d56e331 SR |
82 | struct syscall_metadata **start; |
83 | struct syscall_metadata **stop; | |
c44fc770 FW |
84 | char str[KSYM_SYMBOL_LEN]; |
85 | ||
86 | ||
3d56e331 SR |
87 | start = __start_syscalls_metadata; |
88 | stop = __stop_syscalls_metadata; | |
c44fc770 FW |
89 | kallsyms_lookup(syscall, NULL, NULL, NULL, str); |
90 | ||
ae07f551 IM |
91 | if (arch_syscall_match_sym_name(str, "sys_ni_syscall")) |
92 | return NULL; | |
93 | ||
c44fc770 | 94 | for ( ; start < stop; start++) { |
b2d55496 | 95 | if ((*start)->name && arch_syscall_match_sym_name(str, (*start)->name)) |
3d56e331 | 96 | return *start; |
c44fc770 FW |
97 | } |
98 | return NULL; | |
99 | } | |
100 | ||
101 | static struct syscall_metadata *syscall_nr_to_meta(int nr) | |
102 | { | |
103 | if (!syscalls_metadata || nr >= NR_syscalls || nr < 0) | |
104 | return NULL; | |
105 | ||
106 | return syscalls_metadata[nr]; | |
107 | } | |
108 | ||
6aea49cb | 109 | static enum print_line_t |
a9a57763 SR |
110 | print_syscall_enter(struct trace_iterator *iter, int flags, |
111 | struct trace_event *event) | |
bed1ffca FW |
112 | { |
113 | struct trace_seq *s = &iter->seq; | |
114 | struct trace_entry *ent = iter->ent; | |
115 | struct syscall_trace_enter *trace; | |
116 | struct syscall_metadata *entry; | |
183742f0 | 117 | int i, syscall; |
bed1ffca | 118 | |
64c12e04 | 119 | trace = (typeof(trace))ent; |
bed1ffca | 120 | syscall = trace->nr; |
bed1ffca | 121 | entry = syscall_nr_to_meta(syscall); |
64c12e04 | 122 | |
bed1ffca FW |
123 | if (!entry) |
124 | goto end; | |
125 | ||
32c0edae | 126 | if (entry->enter_event->event.type != ent->type) { |
64c12e04 JB |
127 | WARN_ON_ONCE(1); |
128 | goto end; | |
129 | } | |
130 | ||
183742f0 | 131 | trace_seq_printf(s, "%s(", entry->name); |
bed1ffca FW |
132 | |
133 | for (i = 0; i < entry->nb_args; i++) { | |
183742f0 SRRH |
134 | |
135 | if (trace_seq_has_overflowed(s)) | |
136 | goto end; | |
137 | ||
bed1ffca | 138 | /* parameter types */ |
183742f0 SRRH |
139 | if (trace_flags & TRACE_ITER_VERBOSE) |
140 | trace_seq_printf(s, "%s ", entry->types[i]); | |
141 | ||
bed1ffca | 142 | /* parameter values */ |
183742f0 SRRH |
143 | trace_seq_printf(s, "%s: %lx%s", entry->args[i], |
144 | trace->args[i], | |
145 | i == entry->nb_args - 1 ? "" : ", "); | |
bed1ffca FW |
146 | } |
147 | ||
183742f0 | 148 | trace_seq_putc(s, ')'); |
bed1ffca | 149 | end: |
183742f0 | 150 | trace_seq_putc(s, '\n'); |
4539f077 | 151 | |
183742f0 | 152 | return trace_handle_return(s); |
bed1ffca FW |
153 | } |
154 | ||
6aea49cb | 155 | static enum print_line_t |
a9a57763 SR |
156 | print_syscall_exit(struct trace_iterator *iter, int flags, |
157 | struct trace_event *event) | |
bed1ffca FW |
158 | { |
159 | struct trace_seq *s = &iter->seq; | |
160 | struct trace_entry *ent = iter->ent; | |
161 | struct syscall_trace_exit *trace; | |
162 | int syscall; | |
163 | struct syscall_metadata *entry; | |
bed1ffca | 164 | |
64c12e04 | 165 | trace = (typeof(trace))ent; |
bed1ffca | 166 | syscall = trace->nr; |
bed1ffca | 167 | entry = syscall_nr_to_meta(syscall); |
64c12e04 | 168 | |
bed1ffca | 169 | if (!entry) { |
146c3442 | 170 | trace_seq_putc(s, '\n'); |
183742f0 | 171 | goto out; |
bed1ffca FW |
172 | } |
173 | ||
32c0edae | 174 | if (entry->exit_event->event.type != ent->type) { |
64c12e04 JB |
175 | WARN_ON_ONCE(1); |
176 | return TRACE_TYPE_UNHANDLED; | |
177 | } | |
178 | ||
183742f0 | 179 | trace_seq_printf(s, "%s -> 0x%lx\n", entry->name, |
bed1ffca | 180 | trace->ret); |
bed1ffca | 181 | |
183742f0 SRRH |
182 | out: |
183 | return trace_handle_return(s); | |
bed1ffca FW |
184 | } |
185 | ||
e6971969 LZ |
186 | extern char *__bad_type_size(void); |
187 | ||
188 | #define SYSCALL_FIELD(type, name) \ | |
189 | sizeof(type) != sizeof(trace.name) ? \ | |
190 | __bad_type_size() : \ | |
26a50744 TZ |
191 | #type, #name, offsetof(typeof(trace), name), \ |
192 | sizeof(trace.name), is_signed_type(type) | |
e6971969 | 193 | |
3ddc77f6 LZ |
194 | static int __init |
195 | __set_enter_print_fmt(struct syscall_metadata *entry, char *buf, int len) | |
50307a45 LJ |
196 | { |
197 | int i; | |
198 | int pos = 0; | |
199 | ||
200 | /* When len=0, we just calculate the needed length */ | |
201 | #define LEN_OR_ZERO (len ? len - pos : 0) | |
202 | ||
203 | pos += snprintf(buf + pos, LEN_OR_ZERO, "\""); | |
204 | for (i = 0; i < entry->nb_args; i++) { | |
205 | pos += snprintf(buf + pos, LEN_OR_ZERO, "%s: 0x%%0%zulx%s", | |
206 | entry->args[i], sizeof(unsigned long), | |
207 | i == entry->nb_args - 1 ? "" : ", "); | |
208 | } | |
209 | pos += snprintf(buf + pos, LEN_OR_ZERO, "\""); | |
210 | ||
211 | for (i = 0; i < entry->nb_args; i++) { | |
212 | pos += snprintf(buf + pos, LEN_OR_ZERO, | |
213 | ", ((unsigned long)(REC->%s))", entry->args[i]); | |
214 | } | |
215 | ||
216 | #undef LEN_OR_ZERO | |
217 | ||
218 | /* return the length of print_fmt */ | |
219 | return pos; | |
220 | } | |
221 | ||
3ddc77f6 | 222 | static int __init set_syscall_print_fmt(struct ftrace_event_call *call) |
50307a45 LJ |
223 | { |
224 | char *print_fmt; | |
225 | int len; | |
226 | struct syscall_metadata *entry = call->data; | |
227 | ||
228 | if (entry->enter_event != call) { | |
229 | call->print_fmt = "\"0x%lx\", REC->ret"; | |
230 | return 0; | |
231 | } | |
232 | ||
233 | /* First: called with 0 length to calculate the needed length */ | |
234 | len = __set_enter_print_fmt(entry, NULL, 0); | |
235 | ||
236 | print_fmt = kmalloc(len + 1, GFP_KERNEL); | |
237 | if (!print_fmt) | |
238 | return -ENOMEM; | |
239 | ||
240 | /* Second: actually write the @print_fmt */ | |
241 | __set_enter_print_fmt(entry, print_fmt, len + 1); | |
242 | call->print_fmt = print_fmt; | |
243 | ||
244 | return 0; | |
245 | } | |
246 | ||
3ddc77f6 | 247 | static void __init free_syscall_print_fmt(struct ftrace_event_call *call) |
50307a45 LJ |
248 | { |
249 | struct syscall_metadata *entry = call->data; | |
250 | ||
251 | if (entry->enter_event == call) | |
252 | kfree(call->print_fmt); | |
253 | } | |
254 | ||
b8aae39f | 255 | static int __init syscall_enter_define_fields(struct ftrace_event_call *call) |
540b7b8d LZ |
256 | { |
257 | struct syscall_trace_enter trace; | |
31c16b13 | 258 | struct syscall_metadata *meta = call->data; |
540b7b8d | 259 | int ret; |
540b7b8d LZ |
260 | int i; |
261 | int offset = offsetof(typeof(trace), args); | |
262 | ||
0f1ef51d LJ |
263 | ret = trace_define_field(call, SYSCALL_FIELD(int, nr), FILTER_OTHER); |
264 | if (ret) | |
265 | return ret; | |
266 | ||
540b7b8d | 267 | for (i = 0; i < meta->nb_args; i++) { |
aeaeae11 FW |
268 | ret = trace_define_field(call, meta->types[i], |
269 | meta->args[i], offset, | |
43b51ead LZ |
270 | sizeof(unsigned long), 0, |
271 | FILTER_OTHER); | |
540b7b8d LZ |
272 | offset += sizeof(unsigned long); |
273 | } | |
274 | ||
275 | return ret; | |
276 | } | |
277 | ||
b8aae39f | 278 | static int __init syscall_exit_define_fields(struct ftrace_event_call *call) |
540b7b8d LZ |
279 | { |
280 | struct syscall_trace_exit trace; | |
281 | int ret; | |
282 | ||
0f1ef51d LJ |
283 | ret = trace_define_field(call, SYSCALL_FIELD(int, nr), FILTER_OTHER); |
284 | if (ret) | |
285 | return ret; | |
286 | ||
26a50744 | 287 | ret = trace_define_field(call, SYSCALL_FIELD(long, ret), |
43b51ead | 288 | FILTER_OTHER); |
540b7b8d LZ |
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; |
d562aff9 | 296 | struct ftrace_event_file *ftrace_file; |
bed1ffca FW |
297 | struct syscall_trace_enter *entry; |
298 | struct syscall_metadata *sys_data; | |
299 | struct ring_buffer_event *event; | |
e77405ad | 300 | struct ring_buffer *buffer; |
11034ae9 J |
301 | unsigned long irq_flags; |
302 | int pc; | |
ee08c6ec | 303 | int syscall_nr; |
f431b634 | 304 | int size; |
ee08c6ec | 305 | |
f431b634 | 306 | syscall_nr = trace_get_syscall_nr(current, regs); |
086ba77a | 307 | if (syscall_nr < 0 || syscall_nr >= NR_syscalls) |
cd0980fc | 308 | return; |
d562aff9 TZ |
309 | |
310 | /* Here we're inside tp handler's rcu_read_lock_sched (__DO_TRACE) */ | |
311 | ftrace_file = rcu_dereference_sched(tr->enter_syscall_files[syscall_nr]); | |
312 | if (!ftrace_file) | |
313 | return; | |
314 | ||
13a1e4ae SRRH |
315 | if (ftrace_trigger_soft_disabled(ftrace_file)) |
316 | return; | |
ee08c6ec | 317 | |
bed1ffca FW |
318 | sys_data = syscall_nr_to_meta(syscall_nr); |
319 | if (!sys_data) | |
320 | return; | |
321 | ||
322 | size = sizeof(*entry) + sizeof(unsigned long) * sys_data->nb_args; | |
323 | ||
11034ae9 J |
324 | local_save_flags(irq_flags); |
325 | pc = preempt_count(); | |
326 | ||
12883efb | 327 | buffer = tr->trace_buffer.buffer; |
12ab74ee | 328 | event = trace_buffer_lock_reserve(buffer, |
11034ae9 | 329 | sys_data->enter_event->event.type, size, irq_flags, pc); |
bed1ffca FW |
330 | if (!event) |
331 | return; | |
332 | ||
333 | entry = ring_buffer_event_data(event); | |
334 | entry->nr = syscall_nr; | |
335 | syscall_get_arguments(current, regs, 0, sys_data->nb_args, entry->args); | |
336 | ||
13a1e4ae SRRH |
337 | event_trigger_unlock_commit(ftrace_file, buffer, event, entry, |
338 | irq_flags, pc); | |
ee08c6ec FW |
339 | } |
340 | ||
12ab74ee | 341 | static void ftrace_syscall_exit(void *data, struct pt_regs *regs, long ret) |
ee08c6ec | 342 | { |
12ab74ee | 343 | struct trace_array *tr = data; |
d562aff9 | 344 | struct ftrace_event_file *ftrace_file; |
bed1ffca FW |
345 | struct syscall_trace_exit *entry; |
346 | struct syscall_metadata *sys_data; | |
347 | struct ring_buffer_event *event; | |
e77405ad | 348 | struct ring_buffer *buffer; |
11034ae9 J |
349 | unsigned long irq_flags; |
350 | int pc; | |
ee08c6ec FW |
351 | int syscall_nr; |
352 | ||
f431b634 | 353 | syscall_nr = trace_get_syscall_nr(current, regs); |
086ba77a | 354 | if (syscall_nr < 0 || syscall_nr >= NR_syscalls) |
cd0980fc | 355 | return; |
d562aff9 TZ |
356 | |
357 | /* Here we're inside tp handler's rcu_read_lock_sched (__DO_TRACE()) */ | |
358 | ftrace_file = rcu_dereference_sched(tr->exit_syscall_files[syscall_nr]); | |
359 | if (!ftrace_file) | |
360 | return; | |
361 | ||
13a1e4ae SRRH |
362 | if (ftrace_trigger_soft_disabled(ftrace_file)) |
363 | return; | |
ee08c6ec | 364 | |
bed1ffca FW |
365 | sys_data = syscall_nr_to_meta(syscall_nr); |
366 | if (!sys_data) | |
367 | return; | |
368 | ||
11034ae9 J |
369 | local_save_flags(irq_flags); |
370 | pc = preempt_count(); | |
371 | ||
12883efb | 372 | buffer = tr->trace_buffer.buffer; |
12ab74ee | 373 | event = trace_buffer_lock_reserve(buffer, |
11034ae9 J |
374 | sys_data->exit_event->event.type, sizeof(*entry), |
375 | irq_flags, pc); | |
bed1ffca FW |
376 | if (!event) |
377 | return; | |
378 | ||
379 | entry = ring_buffer_event_data(event); | |
380 | entry->nr = syscall_nr; | |
381 | entry->ret = syscall_get_return_value(current, regs); | |
382 | ||
13a1e4ae SRRH |
383 | event_trigger_unlock_commit(ftrace_file, buffer, event, entry, |
384 | irq_flags, pc); | |
ee08c6ec FW |
385 | } |
386 | ||
12ab74ee SR |
387 | static int reg_event_syscall_enter(struct ftrace_event_file *file, |
388 | struct ftrace_event_call *call) | |
ee08c6ec | 389 | { |
12ab74ee | 390 | struct trace_array *tr = file->tr; |
fb34a08c JB |
391 | int ret = 0; |
392 | int num; | |
fb34a08c | 393 | |
c252f657 | 394 | num = ((struct syscall_metadata *)call->data)->syscall_nr; |
3773b389 | 395 | if (WARN_ON_ONCE(num < 0 || num >= NR_syscalls)) |
fb34a08c JB |
396 | return -ENOSYS; |
397 | mutex_lock(&syscall_trace_lock); | |
12ab74ee SR |
398 | if (!tr->sys_refcount_enter) |
399 | ret = register_trace_sys_enter(ftrace_syscall_enter, tr); | |
3b8e4273 | 400 | if (!ret) { |
d562aff9 | 401 | rcu_assign_pointer(tr->enter_syscall_files[num], file); |
12ab74ee | 402 | tr->sys_refcount_enter++; |
fb34a08c JB |
403 | } |
404 | mutex_unlock(&syscall_trace_lock); | |
405 | return ret; | |
ee08c6ec FW |
406 | } |
407 | ||
12ab74ee SR |
408 | static void unreg_event_syscall_enter(struct ftrace_event_file *file, |
409 | struct ftrace_event_call *call) | |
ee08c6ec | 410 | { |
12ab74ee | 411 | struct trace_array *tr = file->tr; |
fb34a08c | 412 | int num; |
ee08c6ec | 413 | |
c252f657 | 414 | num = ((struct syscall_metadata *)call->data)->syscall_nr; |
3773b389 | 415 | if (WARN_ON_ONCE(num < 0 || num >= NR_syscalls)) |
fb34a08c JB |
416 | return; |
417 | mutex_lock(&syscall_trace_lock); | |
12ab74ee | 418 | tr->sys_refcount_enter--; |
fb5a613b | 419 | RCU_INIT_POINTER(tr->enter_syscall_files[num], NULL); |
12ab74ee SR |
420 | if (!tr->sys_refcount_enter) |
421 | unregister_trace_sys_enter(ftrace_syscall_enter, tr); | |
fb34a08c JB |
422 | mutex_unlock(&syscall_trace_lock); |
423 | } | |
ee08c6ec | 424 | |
12ab74ee SR |
425 | static int reg_event_syscall_exit(struct ftrace_event_file *file, |
426 | struct ftrace_event_call *call) | |
ee08c6ec | 427 | { |
12ab74ee | 428 | struct trace_array *tr = file->tr; |
fb34a08c JB |
429 | int ret = 0; |
430 | int num; | |
fb34a08c | 431 | |
c252f657 | 432 | num = ((struct syscall_metadata *)call->data)->syscall_nr; |
3773b389 | 433 | if (WARN_ON_ONCE(num < 0 || num >= NR_syscalls)) |
fb34a08c JB |
434 | return -ENOSYS; |
435 | mutex_lock(&syscall_trace_lock); | |
12ab74ee SR |
436 | if (!tr->sys_refcount_exit) |
437 | ret = register_trace_sys_exit(ftrace_syscall_exit, tr); | |
3b8e4273 | 438 | if (!ret) { |
d562aff9 | 439 | rcu_assign_pointer(tr->exit_syscall_files[num], file); |
12ab74ee | 440 | tr->sys_refcount_exit++; |
ee08c6ec | 441 | } |
fb34a08c JB |
442 | mutex_unlock(&syscall_trace_lock); |
443 | return ret; | |
444 | } | |
ee08c6ec | 445 | |
12ab74ee SR |
446 | static void unreg_event_syscall_exit(struct ftrace_event_file *file, |
447 | struct ftrace_event_call *call) | |
fb34a08c | 448 | { |
12ab74ee | 449 | struct trace_array *tr = file->tr; |
fb34a08c | 450 | int num; |
ee08c6ec | 451 | |
c252f657 | 452 | num = ((struct syscall_metadata *)call->data)->syscall_nr; |
3773b389 | 453 | if (WARN_ON_ONCE(num < 0 || num >= NR_syscalls)) |
fb34a08c JB |
454 | return; |
455 | mutex_lock(&syscall_trace_lock); | |
12ab74ee | 456 | tr->sys_refcount_exit--; |
fb5a613b | 457 | RCU_INIT_POINTER(tr->exit_syscall_files[num], NULL); |
12ab74ee SR |
458 | if (!tr->sys_refcount_exit) |
459 | unregister_trace_sys_exit(ftrace_syscall_exit, tr); | |
fb34a08c | 460 | mutex_unlock(&syscall_trace_lock); |
ee08c6ec | 461 | } |
fb34a08c | 462 | |
3ddc77f6 | 463 | static int __init init_syscall_trace(struct ftrace_event_call *call) |
a1301da0 LJ |
464 | { |
465 | int id; | |
ba976970 IM |
466 | int num; |
467 | ||
468 | num = ((struct syscall_metadata *)call->data)->syscall_nr; | |
469 | if (num < 0 || num >= NR_syscalls) { | |
470 | pr_debug("syscall %s metadata not mapped, disabling ftrace event\n", | |
471 | ((struct syscall_metadata *)call->data)->name); | |
472 | return -ENOSYS; | |
473 | } | |
a1301da0 | 474 | |
50307a45 LJ |
475 | if (set_syscall_print_fmt(call) < 0) |
476 | return -ENOMEM; | |
477 | ||
c7ef3a90 SR |
478 | id = trace_event_raw_init(call); |
479 | ||
480 | if (id < 0) { | |
50307a45 | 481 | free_syscall_print_fmt(call); |
c7ef3a90 | 482 | return id; |
50307a45 | 483 | } |
c7ef3a90 SR |
484 | |
485 | return id; | |
a1301da0 LJ |
486 | } |
487 | ||
6f86ab9f VN |
488 | struct trace_event_functions enter_syscall_print_funcs = { |
489 | .trace = print_syscall_enter, | |
490 | }; | |
491 | ||
492 | struct trace_event_functions exit_syscall_print_funcs = { | |
493 | .trace = print_syscall_exit, | |
494 | }; | |
495 | ||
523c8113 | 496 | struct ftrace_event_class __refdata event_class_syscall_enter = { |
6f86ab9f VN |
497 | .system = "syscalls", |
498 | .reg = syscall_enter_register, | |
499 | .define_fields = syscall_enter_define_fields, | |
500 | .get_fields = syscall_get_enter_fields, | |
501 | .raw_init = init_syscall_trace, | |
502 | }; | |
503 | ||
523c8113 | 504 | struct ftrace_event_class __refdata event_class_syscall_exit = { |
6f86ab9f VN |
505 | .system = "syscalls", |
506 | .reg = syscall_exit_register, | |
507 | .define_fields = syscall_exit_define_fields, | |
508 | .fields = LIST_HEAD_INIT(event_class_syscall_exit.fields), | |
509 | .raw_init = init_syscall_trace, | |
510 | }; | |
511 | ||
c763ba06 | 512 | unsigned long __init __weak arch_syscall_addr(int nr) |
e7b8e675 MF |
513 | { |
514 | return (unsigned long)sys_call_table[nr]; | |
515 | } | |
516 | ||
5f893b26 | 517 | void __init init_ftrace_syscalls(void) |
c44fc770 FW |
518 | { |
519 | struct syscall_metadata *meta; | |
520 | unsigned long addr; | |
521 | int i; | |
522 | ||
47b0edcb TM |
523 | syscalls_metadata = kcalloc(NR_syscalls, sizeof(*syscalls_metadata), |
524 | GFP_KERNEL); | |
c44fc770 FW |
525 | if (!syscalls_metadata) { |
526 | WARN_ON(1); | |
5f893b26 | 527 | return; |
c44fc770 FW |
528 | } |
529 | ||
530 | for (i = 0; i < NR_syscalls; i++) { | |
531 | addr = arch_syscall_addr(i); | |
532 | meta = find_syscall_meta(addr); | |
c252f657 LJ |
533 | if (!meta) |
534 | continue; | |
535 | ||
536 | meta->syscall_nr = i; | |
c44fc770 FW |
537 | syscalls_metadata[i] = meta; |
538 | } | |
c44fc770 | 539 | } |
c44fc770 | 540 | |
07b139c8 | 541 | #ifdef CONFIG_PERF_EVENTS |
19007a67 | 542 | |
97d5a220 FW |
543 | static DECLARE_BITMAP(enabled_perf_enter_syscalls, NR_syscalls); |
544 | static DECLARE_BITMAP(enabled_perf_exit_syscalls, NR_syscalls); | |
545 | static int sys_perf_refcount_enter; | |
546 | static int sys_perf_refcount_exit; | |
f4b5ffcc | 547 | |
38516ab5 | 548 | static void perf_syscall_enter(void *ignore, struct pt_regs *regs, long id) |
f4b5ffcc JB |
549 | { |
550 | struct syscall_metadata *sys_data; | |
20ab4425 | 551 | struct syscall_trace_enter *rec; |
1c024eca | 552 | struct hlist_head *head; |
f4b5ffcc | 553 | int syscall_nr; |
4ed7c92d | 554 | int rctx; |
19007a67 | 555 | int size; |
f4b5ffcc | 556 | |
f431b634 | 557 | syscall_nr = trace_get_syscall_nr(current, regs); |
086ba77a | 558 | if (syscall_nr < 0 || syscall_nr >= NR_syscalls) |
60916a93 | 559 | return; |
97d5a220 | 560 | if (!test_bit(syscall_nr, enabled_perf_enter_syscalls)) |
f4b5ffcc JB |
561 | return; |
562 | ||
563 | sys_data = syscall_nr_to_meta(syscall_nr); | |
564 | if (!sys_data) | |
565 | return; | |
566 | ||
421c7860 ON |
567 | head = this_cpu_ptr(sys_data->enter_event->perf_events); |
568 | if (hlist_empty(head)) | |
569 | return; | |
570 | ||
19007a67 FW |
571 | /* get the size after alignment with the u32 buffer size field */ |
572 | size = sizeof(unsigned long) * sys_data->nb_args + sizeof(*rec); | |
573 | size = ALIGN(size + sizeof(u32), sizeof(u64)); | |
574 | size -= sizeof(u32); | |
575 | ||
97d5a220 | 576 | rec = (struct syscall_trace_enter *)perf_trace_buf_prepare(size, |
ff5f149b | 577 | sys_data->enter_event->event.type, regs, &rctx); |
430ad5a6 XG |
578 | if (!rec) |
579 | return; | |
20ab4425 | 580 | |
20ab4425 FW |
581 | rec->nr = syscall_nr; |
582 | syscall_get_arguments(current, regs, 0, sys_data->nb_args, | |
583 | (unsigned long *)&rec->args); | |
e6dab5ff | 584 | perf_trace_buf_submit(rec, size, rctx, 0, 1, regs, head, NULL); |
f4b5ffcc JB |
585 | } |
586 | ||
6f86ab9f | 587 | static int perf_sysenter_enable(struct ftrace_event_call *call) |
f4b5ffcc JB |
588 | { |
589 | int ret = 0; | |
590 | int num; | |
591 | ||
3bbe84e9 | 592 | num = ((struct syscall_metadata *)call->data)->syscall_nr; |
f4b5ffcc JB |
593 | |
594 | mutex_lock(&syscall_trace_lock); | |
97d5a220 | 595 | if (!sys_perf_refcount_enter) |
38516ab5 | 596 | ret = register_trace_sys_enter(perf_syscall_enter, NULL); |
f4b5ffcc JB |
597 | if (ret) { |
598 | pr_info("event trace: Could not activate" | |
599 | "syscall entry trace point"); | |
600 | } else { | |
97d5a220 FW |
601 | set_bit(num, enabled_perf_enter_syscalls); |
602 | sys_perf_refcount_enter++; | |
f4b5ffcc JB |
603 | } |
604 | mutex_unlock(&syscall_trace_lock); | |
605 | return ret; | |
606 | } | |
607 | ||
6f86ab9f | 608 | static void perf_sysenter_disable(struct ftrace_event_call *call) |
f4b5ffcc JB |
609 | { |
610 | int num; | |
611 | ||
3bbe84e9 | 612 | num = ((struct syscall_metadata *)call->data)->syscall_nr; |
f4b5ffcc JB |
613 | |
614 | mutex_lock(&syscall_trace_lock); | |
97d5a220 FW |
615 | sys_perf_refcount_enter--; |
616 | clear_bit(num, enabled_perf_enter_syscalls); | |
617 | if (!sys_perf_refcount_enter) | |
38516ab5 | 618 | unregister_trace_sys_enter(perf_syscall_enter, NULL); |
f4b5ffcc JB |
619 | mutex_unlock(&syscall_trace_lock); |
620 | } | |
621 | ||
38516ab5 | 622 | static void perf_syscall_exit(void *ignore, struct pt_regs *regs, long ret) |
f4b5ffcc JB |
623 | { |
624 | struct syscall_metadata *sys_data; | |
20ab4425 | 625 | struct syscall_trace_exit *rec; |
1c024eca | 626 | struct hlist_head *head; |
f4b5ffcc | 627 | int syscall_nr; |
4ed7c92d | 628 | int rctx; |
20ab4425 | 629 | int size; |
f4b5ffcc | 630 | |
f431b634 | 631 | syscall_nr = trace_get_syscall_nr(current, regs); |
086ba77a | 632 | if (syscall_nr < 0 || syscall_nr >= NR_syscalls) |
60916a93 | 633 | return; |
97d5a220 | 634 | if (!test_bit(syscall_nr, enabled_perf_exit_syscalls)) |
f4b5ffcc JB |
635 | return; |
636 | ||
637 | sys_data = syscall_nr_to_meta(syscall_nr); | |
638 | if (!sys_data) | |
639 | return; | |
640 | ||
421c7860 ON |
641 | head = this_cpu_ptr(sys_data->exit_event->perf_events); |
642 | if (hlist_empty(head)) | |
643 | return; | |
644 | ||
20ab4425 FW |
645 | /* We can probably do that at build time */ |
646 | size = ALIGN(sizeof(*rec) + sizeof(u32), sizeof(u64)); | |
647 | size -= sizeof(u32); | |
19007a67 | 648 | |
97d5a220 | 649 | rec = (struct syscall_trace_exit *)perf_trace_buf_prepare(size, |
ff5f149b | 650 | sys_data->exit_event->event.type, regs, &rctx); |
430ad5a6 XG |
651 | if (!rec) |
652 | return; | |
20ab4425 | 653 | |
20ab4425 FW |
654 | rec->nr = syscall_nr; |
655 | rec->ret = syscall_get_return_value(current, regs); | |
e6dab5ff | 656 | perf_trace_buf_submit(rec, size, rctx, 0, 1, regs, head, NULL); |
f4b5ffcc JB |
657 | } |
658 | ||
6f86ab9f | 659 | static int perf_sysexit_enable(struct ftrace_event_call *call) |
f4b5ffcc JB |
660 | { |
661 | int ret = 0; | |
662 | int num; | |
663 | ||
3bbe84e9 | 664 | num = ((struct syscall_metadata *)call->data)->syscall_nr; |
f4b5ffcc JB |
665 | |
666 | mutex_lock(&syscall_trace_lock); | |
97d5a220 | 667 | if (!sys_perf_refcount_exit) |
38516ab5 | 668 | ret = register_trace_sys_exit(perf_syscall_exit, NULL); |
f4b5ffcc JB |
669 | if (ret) { |
670 | pr_info("event trace: Could not activate" | |
6574658b | 671 | "syscall exit trace point"); |
f4b5ffcc | 672 | } else { |
97d5a220 FW |
673 | set_bit(num, enabled_perf_exit_syscalls); |
674 | sys_perf_refcount_exit++; | |
f4b5ffcc JB |
675 | } |
676 | mutex_unlock(&syscall_trace_lock); | |
677 | return ret; | |
678 | } | |
679 | ||
6f86ab9f | 680 | static void perf_sysexit_disable(struct ftrace_event_call *call) |
f4b5ffcc JB |
681 | { |
682 | int num; | |
683 | ||
3bbe84e9 | 684 | num = ((struct syscall_metadata *)call->data)->syscall_nr; |
f4b5ffcc JB |
685 | |
686 | mutex_lock(&syscall_trace_lock); | |
97d5a220 FW |
687 | sys_perf_refcount_exit--; |
688 | clear_bit(num, enabled_perf_exit_syscalls); | |
689 | if (!sys_perf_refcount_exit) | |
38516ab5 | 690 | unregister_trace_sys_exit(perf_syscall_exit, NULL); |
f4b5ffcc JB |
691 | mutex_unlock(&syscall_trace_lock); |
692 | } | |
693 | ||
07b139c8 | 694 | #endif /* CONFIG_PERF_EVENTS */ |
f4b5ffcc | 695 | |
2239291a | 696 | static int syscall_enter_register(struct ftrace_event_call *event, |
ceec0b6f | 697 | enum trace_reg type, void *data) |
2239291a | 698 | { |
12ab74ee SR |
699 | struct ftrace_event_file *file = data; |
700 | ||
2239291a SR |
701 | switch (type) { |
702 | case TRACE_REG_REGISTER: | |
12ab74ee | 703 | return reg_event_syscall_enter(file, event); |
2239291a | 704 | case TRACE_REG_UNREGISTER: |
12ab74ee | 705 | unreg_event_syscall_enter(file, event); |
2239291a SR |
706 | return 0; |
707 | ||
708 | #ifdef CONFIG_PERF_EVENTS | |
709 | case TRACE_REG_PERF_REGISTER: | |
710 | return perf_sysenter_enable(event); | |
711 | case TRACE_REG_PERF_UNREGISTER: | |
712 | perf_sysenter_disable(event); | |
713 | return 0; | |
ceec0b6f JO |
714 | case TRACE_REG_PERF_OPEN: |
715 | case TRACE_REG_PERF_CLOSE: | |
489c75c3 JO |
716 | case TRACE_REG_PERF_ADD: |
717 | case TRACE_REG_PERF_DEL: | |
ceec0b6f | 718 | return 0; |
2239291a SR |
719 | #endif |
720 | } | |
721 | return 0; | |
722 | } | |
723 | ||
724 | static int syscall_exit_register(struct ftrace_event_call *event, | |
ceec0b6f | 725 | enum trace_reg type, void *data) |
2239291a | 726 | { |
12ab74ee SR |
727 | struct ftrace_event_file *file = data; |
728 | ||
2239291a SR |
729 | switch (type) { |
730 | case TRACE_REG_REGISTER: | |
12ab74ee | 731 | return reg_event_syscall_exit(file, event); |
2239291a | 732 | case TRACE_REG_UNREGISTER: |
12ab74ee | 733 | unreg_event_syscall_exit(file, event); |
2239291a SR |
734 | return 0; |
735 | ||
736 | #ifdef CONFIG_PERF_EVENTS | |
737 | case TRACE_REG_PERF_REGISTER: | |
738 | return perf_sysexit_enable(event); | |
739 | case TRACE_REG_PERF_UNREGISTER: | |
740 | perf_sysexit_disable(event); | |
741 | return 0; | |
ceec0b6f JO |
742 | case TRACE_REG_PERF_OPEN: |
743 | case TRACE_REG_PERF_CLOSE: | |
489c75c3 JO |
744 | case TRACE_REG_PERF_ADD: |
745 | case TRACE_REG_PERF_DEL: | |
ceec0b6f | 746 | return 0; |
2239291a SR |
747 | #endif |
748 | } | |
749 | return 0; | |
750 | } |