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Fix: wrapper random documentation
[lttng-modules.git] / lttng-syscalls.c
1 /* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only)
2 *
3 * lttng-syscalls.c
4 *
5 * LTTng syscall probes.
6 *
7 * Copyright (C) 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
8 */
9
10 #include <linux/module.h>
11 #include <linux/slab.h>
12 #include <linux/compat.h>
13 #include <linux/err.h>
14 #include <linux/bitmap.h>
15 #include <linux/in.h>
16 #include <linux/in6.h>
17 #include <linux/seq_file.h>
18 #include <linux/stringify.h>
19 #include <linux/file.h>
20 #include <linux/anon_inodes.h>
21 #include <linux/fcntl.h>
22 #include <asm/ptrace.h>
23 #include <asm/syscall.h>
24
25 #include <lib/bitfield.h>
26 #include <wrapper/rcu.h>
27 #include <lttng-events.h>
28 #include "lttng-tracepoint.h"
29
30 #define LTTNG_SYSCALL_NR_ARGS 6
31
32 #ifndef CONFIG_COMPAT
33 # ifndef is_compat_task
34 # define is_compat_task() (0)
35 # endif
36 #endif
37
38 /* in_compat_syscall appears in kernel 4.6. */
39 #ifndef in_compat_syscall
40 #define in_compat_syscall() is_compat_task()
41 #endif
42
43 enum sc_type {
44 SC_TYPE_ENTRY,
45 SC_TYPE_EXIT,
46 SC_TYPE_COMPAT_ENTRY,
47 SC_TYPE_COMPAT_EXIT,
48 };
49
50 #define SYSCALL_ENTRY_TOK syscall_entry_
51 #define COMPAT_SYSCALL_ENTRY_TOK compat_syscall_entry_
52 #define SYSCALL_EXIT_TOK syscall_exit_
53 #define COMPAT_SYSCALL_EXIT_TOK compat_syscall_exit_
54
55 #define SYSCALL_ENTRY_STR __stringify(SYSCALL_ENTRY_TOK)
56 #define COMPAT_SYSCALL_ENTRY_STR __stringify(COMPAT_SYSCALL_ENTRY_TOK)
57 #define SYSCALL_EXIT_STR __stringify(SYSCALL_EXIT_TOK)
58 #define COMPAT_SYSCALL_EXIT_STR __stringify(COMPAT_SYSCALL_EXIT_TOK)
59
60 static
61 void syscall_entry_probe(void *__data, struct pt_regs *regs, long id);
62 static
63 void syscall_exit_probe(void *__data, struct pt_regs *regs, long ret);
64
65 /*
66 * Forward declarations for old kernels.
67 */
68 struct mmsghdr;
69 struct rlimit64;
70 struct oldold_utsname;
71 struct old_utsname;
72 struct sel_arg_struct;
73 struct mmap_arg_struct;
74 struct file_handle;
75 struct user_msghdr;
76
77 /*
78 * Forward declaration for kernels >= 5.6
79 */
80 struct timex;
81 struct timeval;
82 struct itimerval;
83 struct itimerspec;
84
85 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(5,6,0))
86 typedef __kernel_old_time_t time_t;
87 #endif
88
89 #ifdef IA32_NR_syscalls
90 #define NR_compat_syscalls IA32_NR_syscalls
91 #else
92 #define NR_compat_syscalls NR_syscalls
93 #endif
94
95 /*
96 * Create LTTng tracepoint probes.
97 */
98 #define LTTNG_PACKAGE_BUILD
99 #define CREATE_TRACE_POINTS
100 #define TP_MODULE_NOINIT
101 #define TRACE_INCLUDE_PATH instrumentation/syscalls/headers
102
103 #define PARAMS(args...) args
104
105 /* Handle unknown syscalls */
106 #undef TRACE_SYSTEM
107 #define TRACE_SYSTEM syscalls_unknown
108 #include <instrumentation/syscalls/headers/syscalls_unknown.h>
109 #undef TRACE_SYSTEM
110
111 #define SC_ENTER
112
113 #undef sc_exit
114 #define sc_exit(...)
115 #undef sc_in
116 #define sc_in(...) __VA_ARGS__
117 #undef sc_out
118 #define sc_out(...)
119 #undef sc_inout
120 #define sc_inout(...) __VA_ARGS__
121
122 /* Hijack probe callback for system call enter */
123 #undef TP_PROBE_CB
124 #define TP_PROBE_CB(_template) &syscall_entry_probe
125 #define SC_LTTNG_TRACEPOINT_EVENT(_name, _proto, _args, _fields) \
126 LTTNG_TRACEPOINT_EVENT(syscall_entry_##_name, PARAMS(_proto), PARAMS(_args), \
127 PARAMS(_fields))
128 #define SC_LTTNG_TRACEPOINT_EVENT_CODE(_name, _proto, _args, _locvar, _code_pre, _fields, _code_post) \
129 LTTNG_TRACEPOINT_EVENT_CODE(syscall_entry_##_name, PARAMS(_proto), PARAMS(_args), \
130 PARAMS(_locvar), PARAMS(_code_pre), \
131 PARAMS(_fields), PARAMS(_code_post))
132 #define SC_LTTNG_TRACEPOINT_EVENT_CLASS_NOARGS(_name, _fields) \
133 LTTNG_TRACEPOINT_EVENT_CLASS_NOARGS(syscall_entry_##_name, PARAMS(_fields))
134 #define SC_LTTNG_TRACEPOINT_EVENT_INSTANCE_NOARGS(_template, _name) \
135 LTTNG_TRACEPOINT_EVENT_INSTANCE_NOARGS(syscall_entry_##_template, syscall_entry_##_name)
136 /* Enumerations only defined at first inclusion. */
137 #define SC_LTTNG_TRACEPOINT_ENUM(_name, _values) \
138 LTTNG_TRACEPOINT_ENUM(_name, PARAMS(_values))
139 #undef TRACE_SYSTEM
140 #define TRACE_SYSTEM syscall_entry_integers
141 #define TRACE_INCLUDE_FILE syscalls_integers
142 #include <instrumentation/syscalls/headers/syscalls_integers.h>
143 #undef TRACE_INCLUDE_FILE
144 #undef TRACE_SYSTEM
145 #define TRACE_SYSTEM syscall_entry_pointers
146 #define TRACE_INCLUDE_FILE syscalls_pointers
147 #include <instrumentation/syscalls/headers/syscalls_pointers.h>
148 #undef TRACE_INCLUDE_FILE
149 #undef TRACE_SYSTEM
150 #undef SC_LTTNG_TRACEPOINT_ENUM
151 #undef SC_LTTNG_TRACEPOINT_EVENT_CODE
152 #undef SC_LTTNG_TRACEPOINT_EVENT
153 #undef SC_LTTNG_TRACEPOINT_EVENT_CLASS_NOARGS
154 #undef SC_LTTNG_TRACEPOINT_EVENT_INSTANCE_NOARGS
155 #undef TP_PROBE_CB
156 #undef _TRACE_SYSCALLS_INTEGERS_H
157 #undef _TRACE_SYSCALLS_POINTERS_H
158
159 /* Hijack probe callback for compat system call enter */
160 #define TP_PROBE_CB(_template) &syscall_entry_probe
161 #define LTTNG_SC_COMPAT
162 #define SC_LTTNG_TRACEPOINT_EVENT(_name, _proto, _args, _fields) \
163 LTTNG_TRACEPOINT_EVENT(compat_syscall_entry_##_name, PARAMS(_proto), PARAMS(_args), \
164 PARAMS(_fields))
165 #define SC_LTTNG_TRACEPOINT_EVENT_CODE(_name, _proto, _args, _locvar, _code_pre, _fields, _code_post) \
166 LTTNG_TRACEPOINT_EVENT_CODE(compat_syscall_entry_##_name, PARAMS(_proto), PARAMS(_args), \
167 PARAMS(_locvar), PARAMS(_code_pre), PARAMS(_fields), PARAMS(_code_post))
168 #define SC_LTTNG_TRACEPOINT_EVENT_CLASS_NOARGS(_name, _fields) \
169 LTTNG_TRACEPOINT_EVENT_CLASS_NOARGS(compat_syscall_entry_##_name, PARAMS(_fields))
170 #define SC_LTTNG_TRACEPOINT_EVENT_INSTANCE_NOARGS(_template, _name) \
171 LTTNG_TRACEPOINT_EVENT_INSTANCE_NOARGS(compat_syscall_entry_##_template, \
172 compat_syscall_entry_##_name)
173 /* Enumerations only defined at inital inclusion (not here). */
174 #define SC_LTTNG_TRACEPOINT_ENUM(_name, _values)
175 #define TRACE_SYSTEM compat_syscall_entry_integers
176 #define TRACE_INCLUDE_FILE compat_syscalls_integers
177 #include <instrumentation/syscalls/headers/compat_syscalls_integers.h>
178 #undef TRACE_INCLUDE_FILE
179 #undef TRACE_SYSTEM
180 #define TRACE_SYSTEM compat_syscall_entry_pointers
181 #define TRACE_INCLUDE_FILE compat_syscalls_pointers
182 #include <instrumentation/syscalls/headers/compat_syscalls_pointers.h>
183 #undef TRACE_INCLUDE_FILE
184 #undef TRACE_SYSTEM
185 #undef SC_LTTNG_TRACEPOINT_ENUM
186 #undef SC_LTTNG_TRACEPOINT_EVENT_CODE
187 #undef SC_LTTNG_TRACEPOINT_EVENT
188 #undef SC_LTTNG_TRACEPOINT_EVENT_CLASS_NOARGS
189 #undef SC_LTTNG_TRACEPOINT_EVENT_INSTANCE_NOARGS
190 #undef TP_PROBE_CB
191 #undef _TRACE_SYSCALLS_INTEGERS_H
192 #undef _TRACE_SYSCALLS_POINTERS_H
193 #undef LTTNG_SC_COMPAT
194
195 #undef SC_ENTER
196
197 #define SC_EXIT
198
199 #undef sc_exit
200 #define sc_exit(...) __VA_ARGS__
201 #undef sc_in
202 #define sc_in(...)
203 #undef sc_out
204 #define sc_out(...) __VA_ARGS__
205 #undef sc_inout
206 #define sc_inout(...) __VA_ARGS__
207
208 /* Hijack probe callback for system call exit */
209 #define TP_PROBE_CB(_template) &syscall_exit_probe
210 #define SC_LTTNG_TRACEPOINT_EVENT(_name, _proto, _args, _fields) \
211 LTTNG_TRACEPOINT_EVENT(syscall_exit_##_name, PARAMS(_proto), PARAMS(_args), \
212 PARAMS(_fields))
213 #define SC_LTTNG_TRACEPOINT_EVENT_CODE(_name, _proto, _args, _locvar, _code_pre, _fields, _code_post) \
214 LTTNG_TRACEPOINT_EVENT_CODE(syscall_exit_##_name, PARAMS(_proto), PARAMS(_args), \
215 PARAMS(_locvar), PARAMS(_code_pre), PARAMS(_fields), PARAMS(_code_post))
216 #define SC_LTTNG_TRACEPOINT_EVENT_CLASS_NOARGS(_name, _fields) \
217 LTTNG_TRACEPOINT_EVENT_CLASS_NOARGS(syscall_exit_##_name, PARAMS(_fields))
218 #define SC_LTTNG_TRACEPOINT_EVENT_INSTANCE_NOARGS(_template, _name) \
219 LTTNG_TRACEPOINT_EVENT_INSTANCE_NOARGS(syscall_exit_##_template, \
220 syscall_exit_##_name)
221 /* Enumerations only defined at inital inclusion (not here). */
222 #define SC_LTTNG_TRACEPOINT_ENUM(_name, _values)
223 #define TRACE_SYSTEM syscall_exit_integers
224 #define TRACE_INCLUDE_FILE syscalls_integers
225 #include <instrumentation/syscalls/headers/syscalls_integers.h>
226 #undef TRACE_INCLUDE_FILE
227 #undef TRACE_SYSTEM
228 #define TRACE_SYSTEM syscall_exit_pointers
229 #define TRACE_INCLUDE_FILE syscalls_pointers
230 #include <instrumentation/syscalls/headers/syscalls_pointers.h>
231 #undef TRACE_INCLUDE_FILE
232 #undef TRACE_SYSTEM
233 #undef SC_LTTNG_TRACEPOINT_ENUM
234 #undef SC_LTTNG_TRACEPOINT_EVENT_CODE
235 #undef SC_LTTNG_TRACEPOINT_EVENT
236 #undef SC_LTTNG_TRACEPOINT_EVENT_CLASS_NOARGS
237 #undef SC_LTTNG_TRACEPOINT_EVENT_INSTANCE_NOARGS
238 #undef TP_PROBE_CB
239 #undef _TRACE_SYSCALLS_INTEGERS_H
240 #undef _TRACE_SYSCALLS_POINTERS_H
241
242
243 /* Hijack probe callback for compat system call exit */
244 #define TP_PROBE_CB(_template) &syscall_exit_probe
245 #define LTTNG_SC_COMPAT
246 #define SC_LTTNG_TRACEPOINT_EVENT(_name, _proto, _args, _fields) \
247 LTTNG_TRACEPOINT_EVENT(compat_syscall_exit_##_name, PARAMS(_proto), PARAMS(_args), \
248 PARAMS(_fields))
249 #define SC_LTTNG_TRACEPOINT_EVENT_CODE(_name, _proto, _args, _locvar, _code_pre, _fields, _code_post) \
250 LTTNG_TRACEPOINT_EVENT_CODE(compat_syscall_exit_##_name, PARAMS(_proto), PARAMS(_args), \
251 PARAMS(_locvar), PARAMS(_code_pre), PARAMS(_fields), PARAMS(_code_post))
252 #define SC_LTTNG_TRACEPOINT_EVENT_CLASS_NOARGS(_name, _fields) \
253 LTTNG_TRACEPOINT_EVENT_CLASS_NOARGS(compat_syscall_exit_##_name, PARAMS(_fields))
254 #define SC_LTTNG_TRACEPOINT_EVENT_INSTANCE_NOARGS(_template, _name) \
255 LTTNG_TRACEPOINT_EVENT_INSTANCE_NOARGS(compat_syscall_exit_##_template, \
256 compat_syscall_exit_##_name)
257 /* Enumerations only defined at inital inclusion (not here). */
258 #define SC_LTTNG_TRACEPOINT_ENUM(_name, _values)
259 #define TRACE_SYSTEM compat_syscall_exit_integers
260 #define TRACE_INCLUDE_FILE compat_syscalls_integers
261 #include <instrumentation/syscalls/headers/compat_syscalls_integers.h>
262 #undef TRACE_INCLUDE_FILE
263 #undef TRACE_SYSTEM
264 #define TRACE_SYSTEM compat_syscall_exit_pointers
265 #define TRACE_INCLUDE_FILE compat_syscalls_pointers
266 #include <instrumentation/syscalls/headers/compat_syscalls_pointers.h>
267 #undef TRACE_INCLUDE_FILE
268 #undef TRACE_SYSTEM
269 #undef SC_LTTNG_TRACEPOINT_ENUM
270 #undef SC_LTTNG_TRACEPOINT_EVENT_CODE
271 #undef SC_LTTNG_TRACEPOINT_EVENT
272 #undef SC_LTTNG_TRACEPOINT_EVENT_CLASS_NOARGS
273 #undef SC_LTTNG_TRACEPOINT_EVENT_INSTANCE_NOARGS
274 #undef TP_PROBE_CB
275 #undef _TRACE_SYSCALLS_INTEGERS_H
276 #undef _TRACE_SYSCALLS_POINTERS_H
277 #undef LTTNG_SC_COMPAT
278
279 #undef SC_EXIT
280
281 #undef TP_MODULE_NOINIT
282 #undef LTTNG_PACKAGE_BUILD
283 #undef CREATE_TRACE_POINTS
284
285 struct trace_syscall_entry {
286 void *func;
287 const struct lttng_event_desc *desc;
288 const struct lttng_event_field *fields;
289 unsigned int nrargs;
290 };
291
292 #define CREATE_SYSCALL_TABLE
293
294 #define SC_ENTER
295
296 #undef sc_exit
297 #define sc_exit(...)
298
299 #undef TRACE_SYSCALL_TABLE
300 #define TRACE_SYSCALL_TABLE(_template, _name, _nr, _nrargs) \
301 [ _nr ] = { \
302 .func = __event_probe__syscall_entry_##_template, \
303 .nrargs = (_nrargs), \
304 .fields = __event_fields___syscall_entry_##_template, \
305 .desc = &__event_desc___syscall_entry_##_name, \
306 },
307
308 /* Syscall enter tracing table */
309 static const struct trace_syscall_entry sc_table[] = {
310 #include <instrumentation/syscalls/headers/syscalls_integers.h>
311 #include <instrumentation/syscalls/headers/syscalls_pointers.h>
312 };
313
314 #undef TRACE_SYSCALL_TABLE
315 #define TRACE_SYSCALL_TABLE(_template, _name, _nr, _nrargs) \
316 [ _nr ] = { \
317 .func = __event_probe__compat_syscall_entry_##_template, \
318 .nrargs = (_nrargs), \
319 .fields = __event_fields___compat_syscall_entry_##_template, \
320 .desc = &__event_desc___compat_syscall_entry_##_name, \
321 },
322
323 /* Compat syscall enter table */
324 const struct trace_syscall_entry compat_sc_table[] = {
325 #include <instrumentation/syscalls/headers/compat_syscalls_integers.h>
326 #include <instrumentation/syscalls/headers/compat_syscalls_pointers.h>
327 };
328
329 #undef SC_ENTER
330
331 #define SC_EXIT
332
333 #undef sc_exit
334 #define sc_exit(...) __VA_ARGS__
335
336 #undef TRACE_SYSCALL_TABLE
337 #define TRACE_SYSCALL_TABLE(_template, _name, _nr, _nrargs) \
338 [ _nr ] = { \
339 .func = __event_probe__syscall_exit_##_template, \
340 .nrargs = (_nrargs), \
341 .fields = __event_fields___syscall_exit_##_template, \
342 .desc = &__event_desc___syscall_exit_##_name, \
343 },
344
345 /* Syscall exit table */
346 static const struct trace_syscall_entry sc_exit_table[] = {
347 #include <instrumentation/syscalls/headers/syscalls_integers.h>
348 #include <instrumentation/syscalls/headers/syscalls_pointers.h>
349 };
350
351 #undef TRACE_SYSCALL_TABLE
352 #define TRACE_SYSCALL_TABLE(_template, _name, _nr, _nrargs) \
353 [ _nr ] = { \
354 .func = __event_probe__compat_syscall_exit_##_template, \
355 .nrargs = (_nrargs), \
356 .fields = __event_fields___compat_syscall_exit_##_template, \
357 .desc = &__event_desc___compat_syscall_exit_##_name, \
358 },
359
360 /* Compat syscall exit table */
361 const struct trace_syscall_entry compat_sc_exit_table[] = {
362 #include <instrumentation/syscalls/headers/compat_syscalls_integers.h>
363 #include <instrumentation/syscalls/headers/compat_syscalls_pointers.h>
364 };
365
366 #undef SC_EXIT
367
368 #undef CREATE_SYSCALL_TABLE
369
370 struct lttng_syscall_filter {
371 DECLARE_BITMAP(sc, NR_syscalls);
372 DECLARE_BITMAP(sc_compat, NR_compat_syscalls);
373 };
374
375 static void syscall_entry_unknown(struct lttng_event *event,
376 struct pt_regs *regs, unsigned int id)
377 {
378 unsigned long args[LTTNG_SYSCALL_NR_ARGS];
379
380 syscall_get_arguments(current, regs, args);
381 if (unlikely(in_compat_syscall()))
382 __event_probe__compat_syscall_entry_unknown(event, id, args);
383 else
384 __event_probe__syscall_entry_unknown(event, id, args);
385 }
386
387 void syscall_entry_probe(void *__data, struct pt_regs *regs, long id)
388 {
389 struct lttng_channel *chan = __data;
390 struct lttng_event *event, *unknown_event;
391 const struct trace_syscall_entry *table, *entry;
392 size_t table_len;
393
394 if (unlikely(in_compat_syscall())) {
395 struct lttng_syscall_filter *filter;
396
397 filter = lttng_rcu_dereference(chan->sc_filter);
398 if (filter) {
399 if (id < 0 || id >= NR_compat_syscalls
400 || !test_bit(id, filter->sc_compat)) {
401 /* System call filtered out. */
402 return;
403 }
404 }
405 table = compat_sc_table;
406 table_len = ARRAY_SIZE(compat_sc_table);
407 unknown_event = chan->sc_compat_unknown;
408 } else {
409 struct lttng_syscall_filter *filter;
410
411 filter = lttng_rcu_dereference(chan->sc_filter);
412 if (filter) {
413 if (id < 0 || id >= NR_syscalls
414 || !test_bit(id, filter->sc)) {
415 /* System call filtered out. */
416 return;
417 }
418 }
419 table = sc_table;
420 table_len = ARRAY_SIZE(sc_table);
421 unknown_event = chan->sc_unknown;
422 }
423 if (unlikely(id < 0 || id >= table_len)) {
424 syscall_entry_unknown(unknown_event, regs, id);
425 return;
426 }
427 if (unlikely(in_compat_syscall()))
428 event = chan->compat_sc_table[id];
429 else
430 event = chan->sc_table[id];
431 if (unlikely(!event)) {
432 syscall_entry_unknown(unknown_event, regs, id);
433 return;
434 }
435 entry = &table[id];
436 WARN_ON_ONCE(!entry);
437
438 switch (entry->nrargs) {
439 case 0:
440 {
441 void (*fptr)(void *__data) = entry->func;
442
443 fptr(event);
444 break;
445 }
446 case 1:
447 {
448 void (*fptr)(void *__data, unsigned long arg0) = entry->func;
449 unsigned long args[LTTNG_SYSCALL_NR_ARGS];
450
451 syscall_get_arguments(current, regs, args);
452 fptr(event, args[0]);
453 break;
454 }
455 case 2:
456 {
457 void (*fptr)(void *__data,
458 unsigned long arg0,
459 unsigned long arg1) = entry->func;
460 unsigned long args[LTTNG_SYSCALL_NR_ARGS];
461
462 syscall_get_arguments(current, regs, args);
463 fptr(event, args[0], args[1]);
464 break;
465 }
466 case 3:
467 {
468 void (*fptr)(void *__data,
469 unsigned long arg0,
470 unsigned long arg1,
471 unsigned long arg2) = entry->func;
472 unsigned long args[LTTNG_SYSCALL_NR_ARGS];
473
474 syscall_get_arguments(current, regs, args);
475 fptr(event, args[0], args[1], args[2]);
476 break;
477 }
478 case 4:
479 {
480 void (*fptr)(void *__data,
481 unsigned long arg0,
482 unsigned long arg1,
483 unsigned long arg2,
484 unsigned long arg3) = entry->func;
485 unsigned long args[LTTNG_SYSCALL_NR_ARGS];
486
487 syscall_get_arguments(current, regs, args);
488 fptr(event, args[0], args[1], args[2], args[3]);
489 break;
490 }
491 case 5:
492 {
493 void (*fptr)(void *__data,
494 unsigned long arg0,
495 unsigned long arg1,
496 unsigned long arg2,
497 unsigned long arg3,
498 unsigned long arg4) = entry->func;
499 unsigned long args[LTTNG_SYSCALL_NR_ARGS];
500
501 syscall_get_arguments(current, regs, args);
502 fptr(event, args[0], args[1], args[2], args[3], args[4]);
503 break;
504 }
505 case 6:
506 {
507 void (*fptr)(void *__data,
508 unsigned long arg0,
509 unsigned long arg1,
510 unsigned long arg2,
511 unsigned long arg3,
512 unsigned long arg4,
513 unsigned long arg5) = entry->func;
514 unsigned long args[LTTNG_SYSCALL_NR_ARGS];
515
516 syscall_get_arguments(current, regs, args);
517 fptr(event, args[0], args[1], args[2],
518 args[3], args[4], args[5]);
519 break;
520 }
521 default:
522 break;
523 }
524 }
525
526 static void syscall_exit_unknown(struct lttng_event *event,
527 struct pt_regs *regs, int id, long ret)
528 {
529 unsigned long args[LTTNG_SYSCALL_NR_ARGS];
530
531 syscall_get_arguments(current, regs, args);
532 if (unlikely(in_compat_syscall()))
533 __event_probe__compat_syscall_exit_unknown(event, id, ret,
534 args);
535 else
536 __event_probe__syscall_exit_unknown(event, id, ret, args);
537 }
538
539 void syscall_exit_probe(void *__data, struct pt_regs *regs, long ret)
540 {
541 struct lttng_channel *chan = __data;
542 struct lttng_event *event, *unknown_event;
543 const struct trace_syscall_entry *table, *entry;
544 size_t table_len;
545 long id;
546
547 id = syscall_get_nr(current, regs);
548 if (unlikely(in_compat_syscall())) {
549 struct lttng_syscall_filter *filter;
550
551 filter = lttng_rcu_dereference(chan->sc_filter);
552 if (filter) {
553 if (id < 0 || id >= NR_compat_syscalls
554 || !test_bit(id, filter->sc_compat)) {
555 /* System call filtered out. */
556 return;
557 }
558 }
559 table = compat_sc_exit_table;
560 table_len = ARRAY_SIZE(compat_sc_exit_table);
561 unknown_event = chan->compat_sc_exit_unknown;
562 } else {
563 struct lttng_syscall_filter *filter;
564
565 filter = lttng_rcu_dereference(chan->sc_filter);
566 if (filter) {
567 if (id < 0 || id >= NR_syscalls
568 || !test_bit(id, filter->sc)) {
569 /* System call filtered out. */
570 return;
571 }
572 }
573 table = sc_exit_table;
574 table_len = ARRAY_SIZE(sc_exit_table);
575 unknown_event = chan->sc_exit_unknown;
576 }
577 if (unlikely(id < 0 || id >= table_len)) {
578 syscall_exit_unknown(unknown_event, regs, id, ret);
579 return;
580 }
581 if (unlikely(in_compat_syscall()))
582 event = chan->compat_sc_exit_table[id];
583 else
584 event = chan->sc_exit_table[id];
585 if (unlikely(!event)) {
586 syscall_exit_unknown(unknown_event, regs, id, ret);
587 return;
588 }
589 entry = &table[id];
590 WARN_ON_ONCE(!entry);
591
592 switch (entry->nrargs) {
593 case 0:
594 {
595 void (*fptr)(void *__data, long ret) = entry->func;
596
597 fptr(event, ret);
598 break;
599 }
600 case 1:
601 {
602 void (*fptr)(void *__data,
603 long ret,
604 unsigned long arg0) = entry->func;
605 unsigned long args[LTTNG_SYSCALL_NR_ARGS];
606
607 syscall_get_arguments(current, regs, args);
608 fptr(event, ret, args[0]);
609 break;
610 }
611 case 2:
612 {
613 void (*fptr)(void *__data,
614 long ret,
615 unsigned long arg0,
616 unsigned long arg1) = entry->func;
617 unsigned long args[LTTNG_SYSCALL_NR_ARGS];
618
619 syscall_get_arguments(current, regs, args);
620 fptr(event, ret, args[0], args[1]);
621 break;
622 }
623 case 3:
624 {
625 void (*fptr)(void *__data,
626 long ret,
627 unsigned long arg0,
628 unsigned long arg1,
629 unsigned long arg2) = entry->func;
630 unsigned long args[LTTNG_SYSCALL_NR_ARGS];
631
632 syscall_get_arguments(current, regs, args);
633 fptr(event, ret, args[0], args[1], args[2]);
634 break;
635 }
636 case 4:
637 {
638 void (*fptr)(void *__data,
639 long ret,
640 unsigned long arg0,
641 unsigned long arg1,
642 unsigned long arg2,
643 unsigned long arg3) = entry->func;
644 unsigned long args[LTTNG_SYSCALL_NR_ARGS];
645
646 syscall_get_arguments(current, regs, args);
647 fptr(event, ret, args[0], args[1], args[2], args[3]);
648 break;
649 }
650 case 5:
651 {
652 void (*fptr)(void *__data,
653 long ret,
654 unsigned long arg0,
655 unsigned long arg1,
656 unsigned long arg2,
657 unsigned long arg3,
658 unsigned long arg4) = entry->func;
659 unsigned long args[LTTNG_SYSCALL_NR_ARGS];
660
661 syscall_get_arguments(current, regs, args);
662 fptr(event, ret, args[0], args[1], args[2], args[3], args[4]);
663 break;
664 }
665 case 6:
666 {
667 void (*fptr)(void *__data,
668 long ret,
669 unsigned long arg0,
670 unsigned long arg1,
671 unsigned long arg2,
672 unsigned long arg3,
673 unsigned long arg4,
674 unsigned long arg5) = entry->func;
675 unsigned long args[LTTNG_SYSCALL_NR_ARGS];
676
677 syscall_get_arguments(current, regs, args);
678 fptr(event, ret, args[0], args[1], args[2],
679 args[3], args[4], args[5]);
680 break;
681 }
682 default:
683 break;
684 }
685 }
686
687 /*
688 * noinline to diminish caller stack size.
689 * Should be called with sessions lock held.
690 */
691 static
692 int fill_table(const struct trace_syscall_entry *table, size_t table_len,
693 struct lttng_event **chan_table, struct lttng_channel *chan,
694 void *filter, enum sc_type type)
695 {
696 const struct lttng_event_desc *desc;
697 unsigned int i;
698
699 /* Allocate events for each syscall, insert into table */
700 for (i = 0; i < table_len; i++) {
701 struct lttng_kernel_event ev;
702 desc = table[i].desc;
703
704 if (!desc) {
705 /* Unknown syscall */
706 continue;
707 }
708 /*
709 * Skip those already populated by previous failed
710 * register for this channel.
711 */
712 if (chan_table[i])
713 continue;
714 memset(&ev, 0, sizeof(ev));
715 switch (type) {
716 case SC_TYPE_ENTRY:
717 strncpy(ev.name, SYSCALL_ENTRY_STR,
718 LTTNG_KERNEL_SYM_NAME_LEN);
719 break;
720 case SC_TYPE_EXIT:
721 strncpy(ev.name, SYSCALL_EXIT_STR,
722 LTTNG_KERNEL_SYM_NAME_LEN);
723 break;
724 case SC_TYPE_COMPAT_ENTRY:
725 strncpy(ev.name, COMPAT_SYSCALL_ENTRY_STR,
726 LTTNG_KERNEL_SYM_NAME_LEN);
727 break;
728 case SC_TYPE_COMPAT_EXIT:
729 strncpy(ev.name, COMPAT_SYSCALL_EXIT_STR,
730 LTTNG_KERNEL_SYM_NAME_LEN);
731 break;
732 default:
733 BUG_ON(1);
734 break;
735 }
736 strncat(ev.name, desc->name,
737 LTTNG_KERNEL_SYM_NAME_LEN - strlen(ev.name) - 1);
738 ev.name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
739 ev.instrumentation = LTTNG_KERNEL_SYSCALL;
740 chan_table[i] = _lttng_event_create(chan, &ev, filter,
741 desc, ev.instrumentation);
742 WARN_ON_ONCE(!chan_table[i]);
743 if (IS_ERR(chan_table[i])) {
744 /*
745 * If something goes wrong in event registration
746 * after the first one, we have no choice but to
747 * leave the previous events in there, until
748 * deleted by session teardown.
749 */
750 return PTR_ERR(chan_table[i]);
751 }
752 }
753 return 0;
754 }
755
756 /*
757 * Should be called with sessions lock held.
758 */
759 int lttng_syscalls_register(struct lttng_channel *chan, void *filter)
760 {
761 struct lttng_kernel_event ev;
762 int ret;
763
764 if (!chan->sc_table) {
765 /* create syscall table mapping syscall to events */
766 chan->sc_table = kzalloc(sizeof(struct lttng_event *)
767 * ARRAY_SIZE(sc_table), GFP_KERNEL);
768 if (!chan->sc_table)
769 return -ENOMEM;
770 }
771 if (!chan->sc_exit_table) {
772 /* create syscall table mapping syscall to events */
773 chan->sc_exit_table = kzalloc(sizeof(struct lttng_event *)
774 * ARRAY_SIZE(sc_exit_table), GFP_KERNEL);
775 if (!chan->sc_exit_table)
776 return -ENOMEM;
777 }
778
779
780 #ifdef CONFIG_COMPAT
781 if (!chan->compat_sc_table) {
782 /* create syscall table mapping compat syscall to events */
783 chan->compat_sc_table = kzalloc(sizeof(struct lttng_event *)
784 * ARRAY_SIZE(compat_sc_table), GFP_KERNEL);
785 if (!chan->compat_sc_table)
786 return -ENOMEM;
787 }
788
789 if (!chan->compat_sc_exit_table) {
790 /* create syscall table mapping compat syscall to events */
791 chan->compat_sc_exit_table = kzalloc(sizeof(struct lttng_event *)
792 * ARRAY_SIZE(compat_sc_exit_table), GFP_KERNEL);
793 if (!chan->compat_sc_exit_table)
794 return -ENOMEM;
795 }
796 #endif
797 if (!chan->sc_unknown) {
798 const struct lttng_event_desc *desc =
799 &__event_desc___syscall_entry_unknown;
800
801 memset(&ev, 0, sizeof(ev));
802 strncpy(ev.name, desc->name, LTTNG_KERNEL_SYM_NAME_LEN);
803 ev.name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
804 ev.instrumentation = LTTNG_KERNEL_SYSCALL;
805 chan->sc_unknown = _lttng_event_create(chan, &ev, filter,
806 desc,
807 ev.instrumentation);
808 WARN_ON_ONCE(!chan->sc_unknown);
809 if (IS_ERR(chan->sc_unknown)) {
810 return PTR_ERR(chan->sc_unknown);
811 }
812 }
813
814 if (!chan->sc_compat_unknown) {
815 const struct lttng_event_desc *desc =
816 &__event_desc___compat_syscall_entry_unknown;
817
818 memset(&ev, 0, sizeof(ev));
819 strncpy(ev.name, desc->name, LTTNG_KERNEL_SYM_NAME_LEN);
820 ev.name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
821 ev.instrumentation = LTTNG_KERNEL_SYSCALL;
822 chan->sc_compat_unknown = _lttng_event_create(chan, &ev, filter,
823 desc,
824 ev.instrumentation);
825 WARN_ON_ONCE(!chan->sc_unknown);
826 if (IS_ERR(chan->sc_compat_unknown)) {
827 return PTR_ERR(chan->sc_compat_unknown);
828 }
829 }
830
831 if (!chan->compat_sc_exit_unknown) {
832 const struct lttng_event_desc *desc =
833 &__event_desc___compat_syscall_exit_unknown;
834
835 memset(&ev, 0, sizeof(ev));
836 strncpy(ev.name, desc->name, LTTNG_KERNEL_SYM_NAME_LEN);
837 ev.name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
838 ev.instrumentation = LTTNG_KERNEL_SYSCALL;
839 chan->compat_sc_exit_unknown = _lttng_event_create(chan, &ev,
840 filter, desc,
841 ev.instrumentation);
842 WARN_ON_ONCE(!chan->compat_sc_exit_unknown);
843 if (IS_ERR(chan->compat_sc_exit_unknown)) {
844 return PTR_ERR(chan->compat_sc_exit_unknown);
845 }
846 }
847
848 if (!chan->sc_exit_unknown) {
849 const struct lttng_event_desc *desc =
850 &__event_desc___syscall_exit_unknown;
851
852 memset(&ev, 0, sizeof(ev));
853 strncpy(ev.name, desc->name, LTTNG_KERNEL_SYM_NAME_LEN);
854 ev.name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
855 ev.instrumentation = LTTNG_KERNEL_SYSCALL;
856 chan->sc_exit_unknown = _lttng_event_create(chan, &ev, filter,
857 desc, ev.instrumentation);
858 WARN_ON_ONCE(!chan->sc_exit_unknown);
859 if (IS_ERR(chan->sc_exit_unknown)) {
860 return PTR_ERR(chan->sc_exit_unknown);
861 }
862 }
863
864 ret = fill_table(sc_table, ARRAY_SIZE(sc_table),
865 chan->sc_table, chan, filter, SC_TYPE_ENTRY);
866 if (ret)
867 return ret;
868 ret = fill_table(sc_exit_table, ARRAY_SIZE(sc_exit_table),
869 chan->sc_exit_table, chan, filter, SC_TYPE_EXIT);
870 if (ret)
871 return ret;
872
873 #ifdef CONFIG_COMPAT
874 ret = fill_table(compat_sc_table, ARRAY_SIZE(compat_sc_table),
875 chan->compat_sc_table, chan, filter,
876 SC_TYPE_COMPAT_ENTRY);
877 if (ret)
878 return ret;
879 ret = fill_table(compat_sc_exit_table, ARRAY_SIZE(compat_sc_exit_table),
880 chan->compat_sc_exit_table, chan, filter,
881 SC_TYPE_COMPAT_EXIT);
882 if (ret)
883 return ret;
884 #endif
885 if (!chan->sys_enter_registered) {
886 ret = lttng_tracepoint_probe_register("sys_enter",
887 (void *) syscall_entry_probe, chan);
888 if (ret)
889 return ret;
890 chan->sys_enter_registered = 1;
891 }
892 /*
893 * We change the name of sys_exit tracepoint due to namespace
894 * conflict with sys_exit syscall entry.
895 */
896 if (!chan->sys_exit_registered) {
897 ret = lttng_tracepoint_probe_register("sys_exit",
898 (void *) syscall_exit_probe, chan);
899 if (ret) {
900 WARN_ON_ONCE(lttng_tracepoint_probe_unregister("sys_enter",
901 (void *) syscall_entry_probe, chan));
902 return ret;
903 }
904 chan->sys_exit_registered = 1;
905 }
906 return ret;
907 }
908
909 /*
910 * Only called at session destruction.
911 */
912 int lttng_syscalls_unregister(struct lttng_channel *chan)
913 {
914 int ret;
915
916 if (!chan->sc_table)
917 return 0;
918 if (chan->sys_enter_registered) {
919 ret = lttng_tracepoint_probe_unregister("sys_enter",
920 (void *) syscall_entry_probe, chan);
921 if (ret)
922 return ret;
923 chan->sys_enter_registered = 0;
924 }
925 if (chan->sys_exit_registered) {
926 ret = lttng_tracepoint_probe_unregister("sys_exit",
927 (void *) syscall_exit_probe, chan);
928 if (ret)
929 return ret;
930 chan->sys_exit_registered = 0;
931 }
932 /* lttng_event destroy will be performed by lttng_session_destroy() */
933 kfree(chan->sc_table);
934 kfree(chan->sc_exit_table);
935 #ifdef CONFIG_COMPAT
936 kfree(chan->compat_sc_table);
937 kfree(chan->compat_sc_exit_table);
938 #endif
939 kfree(chan->sc_filter);
940 return 0;
941 }
942
943 static
944 int get_syscall_nr(const char *syscall_name)
945 {
946 int syscall_nr = -1;
947 int i;
948
949 for (i = 0; i < ARRAY_SIZE(sc_table); i++) {
950 const struct trace_syscall_entry *entry;
951 const char *it_name;
952
953 entry = &sc_table[i];
954 if (!entry->desc)
955 continue;
956 it_name = entry->desc->name;
957 it_name += strlen(SYSCALL_ENTRY_STR);
958 if (!strcmp(syscall_name, it_name)) {
959 syscall_nr = i;
960 break;
961 }
962 }
963 return syscall_nr;
964 }
965
966 static
967 int get_compat_syscall_nr(const char *syscall_name)
968 {
969 int syscall_nr = -1;
970 int i;
971
972 for (i = 0; i < ARRAY_SIZE(compat_sc_table); i++) {
973 const struct trace_syscall_entry *entry;
974 const char *it_name;
975
976 entry = &compat_sc_table[i];
977 if (!entry->desc)
978 continue;
979 it_name = entry->desc->name;
980 it_name += strlen(COMPAT_SYSCALL_ENTRY_STR);
981 if (!strcmp(syscall_name, it_name)) {
982 syscall_nr = i;
983 break;
984 }
985 }
986 return syscall_nr;
987 }
988
989 static
990 uint32_t get_sc_tables_len(void)
991 {
992 return ARRAY_SIZE(sc_table) + ARRAY_SIZE(compat_sc_table);
993 }
994
995 int lttng_syscall_filter_enable(struct lttng_channel *chan,
996 const char *name)
997 {
998 int syscall_nr, compat_syscall_nr, ret;
999 struct lttng_syscall_filter *filter;
1000
1001 WARN_ON_ONCE(!chan->sc_table);
1002
1003 if (!name) {
1004 /* Enable all system calls by removing filter */
1005 if (chan->sc_filter) {
1006 filter = chan->sc_filter;
1007 rcu_assign_pointer(chan->sc_filter, NULL);
1008 synchronize_trace();
1009 kfree(filter);
1010 }
1011 chan->syscall_all = 1;
1012 return 0;
1013 }
1014
1015 if (!chan->sc_filter) {
1016 if (chan->syscall_all) {
1017 /*
1018 * All syscalls are already enabled.
1019 */
1020 return -EEXIST;
1021 }
1022 filter = kzalloc(sizeof(struct lttng_syscall_filter),
1023 GFP_KERNEL);
1024 if (!filter)
1025 return -ENOMEM;
1026 } else {
1027 filter = chan->sc_filter;
1028 }
1029 syscall_nr = get_syscall_nr(name);
1030 compat_syscall_nr = get_compat_syscall_nr(name);
1031 if (syscall_nr < 0 && compat_syscall_nr < 0) {
1032 ret = -ENOENT;
1033 goto error;
1034 }
1035 if (syscall_nr >= 0) {
1036 if (test_bit(syscall_nr, filter->sc)) {
1037 ret = -EEXIST;
1038 goto error;
1039 }
1040 bitmap_set(filter->sc, syscall_nr, 1);
1041 }
1042 if (compat_syscall_nr >= 0) {
1043 if (test_bit(compat_syscall_nr, filter->sc_compat)) {
1044 ret = -EEXIST;
1045 goto error;
1046 }
1047 bitmap_set(filter->sc_compat, compat_syscall_nr, 1);
1048 }
1049 if (!chan->sc_filter)
1050 rcu_assign_pointer(chan->sc_filter, filter);
1051 return 0;
1052
1053 error:
1054 if (!chan->sc_filter)
1055 kfree(filter);
1056 return ret;
1057 }
1058
1059 int lttng_syscall_filter_disable(struct lttng_channel *chan,
1060 const char *name)
1061 {
1062 int syscall_nr, compat_syscall_nr, ret;
1063 struct lttng_syscall_filter *filter;
1064
1065 WARN_ON_ONCE(!chan->sc_table);
1066
1067 if (!chan->sc_filter) {
1068 if (!chan->syscall_all)
1069 return -EEXIST;
1070 filter = kzalloc(sizeof(struct lttng_syscall_filter),
1071 GFP_KERNEL);
1072 if (!filter)
1073 return -ENOMEM;
1074 /* Trace all system calls, then apply disable. */
1075 bitmap_set(filter->sc, 0, NR_syscalls);
1076 bitmap_set(filter->sc_compat, 0, NR_compat_syscalls);
1077 } else {
1078 filter = chan->sc_filter;
1079 }
1080
1081 if (!name) {
1082 /* Fail if all syscalls are already disabled. */
1083 if (bitmap_empty(filter->sc, NR_syscalls)
1084 && bitmap_empty(filter->sc_compat,
1085 NR_compat_syscalls)) {
1086 ret = -EEXIST;
1087 goto error;
1088 }
1089
1090 /* Disable all system calls */
1091 bitmap_clear(filter->sc, 0, NR_syscalls);
1092 bitmap_clear(filter->sc_compat, 0, NR_compat_syscalls);
1093 goto apply_filter;
1094 }
1095 syscall_nr = get_syscall_nr(name);
1096 compat_syscall_nr = get_compat_syscall_nr(name);
1097 if (syscall_nr < 0 && compat_syscall_nr < 0) {
1098 ret = -ENOENT;
1099 goto error;
1100 }
1101 if (syscall_nr >= 0) {
1102 if (!test_bit(syscall_nr, filter->sc)) {
1103 ret = -EEXIST;
1104 goto error;
1105 }
1106 bitmap_clear(filter->sc, syscall_nr, 1);
1107 }
1108 if (compat_syscall_nr >= 0) {
1109 if (!test_bit(compat_syscall_nr, filter->sc_compat)) {
1110 ret = -EEXIST;
1111 goto error;
1112 }
1113 bitmap_clear(filter->sc_compat, compat_syscall_nr, 1);
1114 }
1115 apply_filter:
1116 if (!chan->sc_filter)
1117 rcu_assign_pointer(chan->sc_filter, filter);
1118 chan->syscall_all = 0;
1119 return 0;
1120
1121 error:
1122 if (!chan->sc_filter)
1123 kfree(filter);
1124 return ret;
1125 }
1126
1127 static
1128 const struct trace_syscall_entry *syscall_list_get_entry(loff_t *pos)
1129 {
1130 const struct trace_syscall_entry *entry;
1131 int iter = 0;
1132
1133 for (entry = sc_table;
1134 entry < sc_table + ARRAY_SIZE(sc_table);
1135 entry++) {
1136 if (iter++ >= *pos)
1137 return entry;
1138 }
1139 for (entry = compat_sc_table;
1140 entry < compat_sc_table + ARRAY_SIZE(compat_sc_table);
1141 entry++) {
1142 if (iter++ >= *pos)
1143 return entry;
1144 }
1145 /* End of list */
1146 return NULL;
1147 }
1148
1149 static
1150 void *syscall_list_start(struct seq_file *m, loff_t *pos)
1151 {
1152 return (void *) syscall_list_get_entry(pos);
1153 }
1154
1155 static
1156 void *syscall_list_next(struct seq_file *m, void *p, loff_t *ppos)
1157 {
1158 (*ppos)++;
1159 return (void *) syscall_list_get_entry(ppos);
1160 }
1161
1162 static
1163 void syscall_list_stop(struct seq_file *m, void *p)
1164 {
1165 }
1166
1167 static
1168 int get_sc_table(const struct trace_syscall_entry *entry,
1169 const struct trace_syscall_entry **table,
1170 unsigned int *bitness)
1171 {
1172 if (entry >= sc_table && entry < sc_table + ARRAY_SIZE(sc_table)) {
1173 if (bitness)
1174 *bitness = BITS_PER_LONG;
1175 if (table)
1176 *table = sc_table;
1177 return 0;
1178 }
1179 if (!(entry >= compat_sc_table
1180 && entry < compat_sc_table + ARRAY_SIZE(compat_sc_table))) {
1181 return -EINVAL;
1182 }
1183 if (bitness)
1184 *bitness = 32;
1185 if (table)
1186 *table = compat_sc_table;
1187 return 0;
1188 }
1189
1190 static
1191 int syscall_list_show(struct seq_file *m, void *p)
1192 {
1193 const struct trace_syscall_entry *table, *entry = p;
1194 unsigned int bitness;
1195 unsigned long index;
1196 int ret;
1197 const char *name;
1198
1199 ret = get_sc_table(entry, &table, &bitness);
1200 if (ret)
1201 return ret;
1202 if (!entry->desc)
1203 return 0;
1204 if (table == sc_table) {
1205 index = entry - table;
1206 name = &entry->desc->name[strlen(SYSCALL_ENTRY_STR)];
1207 } else {
1208 index = (entry - table) + ARRAY_SIZE(sc_table);
1209 name = &entry->desc->name[strlen(COMPAT_SYSCALL_ENTRY_STR)];
1210 }
1211 seq_printf(m, "syscall { index = %lu; name = %s; bitness = %u; };\n",
1212 index, name, bitness);
1213 return 0;
1214 }
1215
1216 static
1217 const struct seq_operations lttng_syscall_list_seq_ops = {
1218 .start = syscall_list_start,
1219 .next = syscall_list_next,
1220 .stop = syscall_list_stop,
1221 .show = syscall_list_show,
1222 };
1223
1224 static
1225 int lttng_syscall_list_open(struct inode *inode, struct file *file)
1226 {
1227 return seq_open(file, &lttng_syscall_list_seq_ops);
1228 }
1229
1230 const struct file_operations lttng_syscall_list_fops = {
1231 .owner = THIS_MODULE,
1232 .open = lttng_syscall_list_open,
1233 .read = seq_read,
1234 .llseek = seq_lseek,
1235 .release = seq_release,
1236 };
1237
1238 long lttng_channel_syscall_mask(struct lttng_channel *channel,
1239 struct lttng_kernel_syscall_mask __user *usyscall_mask)
1240 {
1241 uint32_t len, sc_tables_len, bitmask_len;
1242 int ret = 0, bit;
1243 char *tmp_mask;
1244 struct lttng_syscall_filter *filter;
1245
1246 ret = get_user(len, &usyscall_mask->len);
1247 if (ret)
1248 return ret;
1249 sc_tables_len = get_sc_tables_len();
1250 bitmask_len = ALIGN(sc_tables_len, 8) >> 3;
1251 if (len < sc_tables_len) {
1252 return put_user(sc_tables_len, &usyscall_mask->len);
1253 }
1254 /* Array is large enough, we can copy array to user-space. */
1255 tmp_mask = kzalloc(bitmask_len, GFP_KERNEL);
1256 if (!tmp_mask)
1257 return -ENOMEM;
1258 filter = channel->sc_filter;
1259
1260 for (bit = 0; bit < ARRAY_SIZE(sc_table); bit++) {
1261 char state;
1262
1263 if (channel->sc_table) {
1264 if (filter)
1265 state = test_bit(bit, filter->sc);
1266 else
1267 state = 1;
1268 } else {
1269 state = 0;
1270 }
1271 bt_bitfield_write_be(tmp_mask, char, bit, 1, state);
1272 }
1273 for (; bit < sc_tables_len; bit++) {
1274 char state;
1275
1276 if (channel->compat_sc_table) {
1277 if (filter)
1278 state = test_bit(bit - ARRAY_SIZE(sc_table),
1279 filter->sc_compat);
1280 else
1281 state = 1;
1282 } else {
1283 state = 0;
1284 }
1285 bt_bitfield_write_be(tmp_mask, char, bit, 1, state);
1286 }
1287 if (copy_to_user(usyscall_mask->mask, tmp_mask, bitmask_len))
1288 ret = -EFAULT;
1289 kfree(tmp_mask);
1290 return ret;
1291 }
1292
1293 int lttng_abi_syscall_list(void)
1294 {
1295 struct file *syscall_list_file;
1296 int file_fd, ret;
1297
1298 file_fd = get_unused_fd_flags(0);
1299 if (file_fd < 0) {
1300 ret = file_fd;
1301 goto fd_error;
1302 }
1303
1304 syscall_list_file = anon_inode_getfile("[lttng_syscall_list]",
1305 &lttng_syscall_list_fops,
1306 NULL, O_RDWR);
1307 if (IS_ERR(syscall_list_file)) {
1308 ret = PTR_ERR(syscall_list_file);
1309 goto file_error;
1310 }
1311 ret = lttng_syscall_list_fops.open(NULL, syscall_list_file);
1312 if (ret < 0)
1313 goto open_error;
1314 fd_install(file_fd, syscall_list_file);
1315 return file_fd;
1316
1317 open_error:
1318 fput(syscall_list_file);
1319 file_error:
1320 put_unused_fd(file_fd);
1321 fd_error:
1322 return ret;
1323 }
LTTng 2.0/0.x modules
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