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Fix: update writeback instrumentation for kernel 4.14
[lttng-modules.git] / lttng-syscalls.c
1 /*
2 * lttng-syscalls.c
3 *
4 * LTTng syscall probes.
5 *
6 * Copyright (C) 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
7 *
8 * This library is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; only
11 * version 2.1 of the License.
12 *
13 * This library is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Lesser General Public License for more details.
17 *
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with this library; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 */
22
23 #include <linux/module.h>
24 #include <linux/slab.h>
25 #include <linux/compat.h>
26 #include <linux/err.h>
27 #include <linux/bitmap.h>
28 #include <linux/in.h>
29 #include <linux/in6.h>
30 #include <linux/seq_file.h>
31 #include <linux/stringify.h>
32 #include <linux/file.h>
33 #include <linux/anon_inodes.h>
34 #include <asm/ptrace.h>
35 #include <asm/syscall.h>
36
37 #include <lib/bitfield.h>
38 #include <wrapper/tracepoint.h>
39 #include <wrapper/file.h>
40 #include <wrapper/rcu.h>
41 #include <lttng-events.h>
42
43 #ifndef CONFIG_COMPAT
44 # ifndef is_compat_task
45 # define is_compat_task() (0)
46 # endif
47 #endif
48
49 /* in_compat_syscall appears in kernel 4.6. */
50 #ifndef in_compat_syscall
51 #define in_compat_syscall() is_compat_task()
52 #endif
53
54 enum sc_type {
55 SC_TYPE_ENTRY,
56 SC_TYPE_EXIT,
57 SC_TYPE_COMPAT_ENTRY,
58 SC_TYPE_COMPAT_EXIT,
59 };
60
61 #define SYSCALL_ENTRY_TOK syscall_entry_
62 #define COMPAT_SYSCALL_ENTRY_TOK compat_syscall_entry_
63 #define SYSCALL_EXIT_TOK syscall_exit_
64 #define COMPAT_SYSCALL_EXIT_TOK compat_syscall_exit_
65
66 #define SYSCALL_ENTRY_STR __stringify(SYSCALL_ENTRY_TOK)
67 #define COMPAT_SYSCALL_ENTRY_STR __stringify(COMPAT_SYSCALL_ENTRY_TOK)
68 #define SYSCALL_EXIT_STR __stringify(SYSCALL_EXIT_TOK)
69 #define COMPAT_SYSCALL_EXIT_STR __stringify(COMPAT_SYSCALL_EXIT_TOK)
70
71 static
72 void syscall_entry_probe(void *__data, struct pt_regs *regs, long id);
73 static
74 void syscall_exit_probe(void *__data, struct pt_regs *regs, long ret);
75
76 /*
77 * Forward declarations for old kernels.
78 */
79 struct mmsghdr;
80 struct rlimit64;
81 struct oldold_utsname;
82 struct old_utsname;
83 struct sel_arg_struct;
84 struct mmap_arg_struct;
85 struct file_handle;
86 struct user_msghdr;
87
88 #ifdef IA32_NR_syscalls
89 #define NR_compat_syscalls IA32_NR_syscalls
90 #else
91 #define NR_compat_syscalls NR_syscalls
92 #endif
93
94 /*
95 * Create LTTng tracepoint probes.
96 */
97 #define LTTNG_PACKAGE_BUILD
98 #define CREATE_TRACE_POINTS
99 #define TP_MODULE_NOINIT
100 #define TRACE_INCLUDE_PATH instrumentation/syscalls/headers
101
102 #define PARAMS(args...) args
103
104 /* Handle unknown syscalls */
105 #undef TRACE_SYSTEM
106 #define TRACE_SYSTEM syscalls_unknown
107 #include <instrumentation/syscalls/headers/syscalls_unknown.h>
108 #undef TRACE_SYSTEM
109
110 #define SC_ENTER
111
112 #undef sc_exit
113 #define sc_exit(...)
114 #undef sc_in
115 #define sc_in(...) __VA_ARGS__
116 #undef sc_out
117 #define sc_out(...)
118 #undef sc_inout
119 #define sc_inout(...) __VA_ARGS__
120
121 /* Hijack probe callback for system call enter */
122 #undef TP_PROBE_CB
123 #define TP_PROBE_CB(_template) &syscall_entry_probe
124 #define SC_LTTNG_TRACEPOINT_EVENT(_name, _proto, _args, _fields) \
125 LTTNG_TRACEPOINT_EVENT(syscall_entry_##_name, PARAMS(_proto), PARAMS(_args), \
126 PARAMS(_fields))
127 #define SC_LTTNG_TRACEPOINT_EVENT_CODE(_name, _proto, _args, _locvar, _code_pre, _fields, _code_post) \
128 LTTNG_TRACEPOINT_EVENT_CODE(syscall_entry_##_name, PARAMS(_proto), PARAMS(_args), \
129 PARAMS(_locvar), PARAMS(_code_pre), \
130 PARAMS(_fields), PARAMS(_code_post))
131 #define SC_LTTNG_TRACEPOINT_EVENT_CLASS_NOARGS(_name, _fields) \
132 LTTNG_TRACEPOINT_EVENT_CLASS_NOARGS(syscall_entry_##_name, PARAMS(_fields))
133 #define SC_LTTNG_TRACEPOINT_EVENT_INSTANCE_NOARGS(_template, _name) \
134 LTTNG_TRACEPOINT_EVENT_INSTANCE_NOARGS(syscall_entry_##_template, syscall_entry_##_name)
135 /* Enumerations only defined at first inclusion. */
136 #define SC_LTTNG_TRACEPOINT_ENUM(_name, _values) \
137 LTTNG_TRACEPOINT_ENUM(_name, PARAMS(_values))
138 #undef TRACE_SYSTEM
139 #define TRACE_SYSTEM syscall_entry_integers
140 #define TRACE_INCLUDE_FILE syscalls_integers
141 #include <instrumentation/syscalls/headers/syscalls_integers.h>
142 #undef TRACE_INCLUDE_FILE
143 #undef TRACE_SYSTEM
144 #define TRACE_SYSTEM syscall_entry_pointers
145 #define TRACE_INCLUDE_FILE syscalls_pointers
146 #include <instrumentation/syscalls/headers/syscalls_pointers.h>
147 #undef TRACE_INCLUDE_FILE
148 #undef TRACE_SYSTEM
149 #undef SC_LTTNG_TRACEPOINT_ENUM
150 #undef SC_LTTNG_TRACEPOINT_EVENT_CODE
151 #undef SC_LTTNG_TRACEPOINT_EVENT
152 #undef SC_LTTNG_TRACEPOINT_EVENT_CLASS_NOARGS
153 #undef SC_LTTNG_TRACEPOINT_EVENT_INSTANCE_NOARGS
154 #undef TP_PROBE_CB
155 #undef _TRACE_SYSCALLS_INTEGERS_H
156 #undef _TRACE_SYSCALLS_POINTERS_H
157
158 /* Hijack probe callback for compat system call enter */
159 #define TP_PROBE_CB(_template) &syscall_entry_probe
160 #define LTTNG_SC_COMPAT
161 #define SC_LTTNG_TRACEPOINT_EVENT(_name, _proto, _args, _fields) \
162 LTTNG_TRACEPOINT_EVENT(compat_syscall_entry_##_name, PARAMS(_proto), PARAMS(_args), \
163 PARAMS(_fields))
164 #define SC_LTTNG_TRACEPOINT_EVENT_CODE(_name, _proto, _args, _locvar, _code_pre, _fields, _code_post) \
165 LTTNG_TRACEPOINT_EVENT_CODE(compat_syscall_entry_##_name, PARAMS(_proto), PARAMS(_args), \
166 PARAMS(_locvar), PARAMS(_code_pre), PARAMS(_fields), PARAMS(_code_post))
167 #define SC_LTTNG_TRACEPOINT_EVENT_CLASS_NOARGS(_name, _fields) \
168 LTTNG_TRACEPOINT_EVENT_CLASS_NOARGS(compat_syscall_entry_##_name, PARAMS(_fields))
169 #define SC_LTTNG_TRACEPOINT_EVENT_INSTANCE_NOARGS(_template, _name) \
170 LTTNG_TRACEPOINT_EVENT_INSTANCE_NOARGS(compat_syscall_entry_##_template, \
171 compat_syscall_entry_##_name)
172 /* Enumerations only defined at inital inclusion (not here). */
173 #define SC_LTTNG_TRACEPOINT_ENUM(_name, _values)
174 #define TRACE_SYSTEM compat_syscall_entry_integers
175 #define TRACE_INCLUDE_FILE compat_syscalls_integers
176 #include <instrumentation/syscalls/headers/compat_syscalls_integers.h>
177 #undef TRACE_INCLUDE_FILE
178 #undef TRACE_SYSTEM
179 #define TRACE_SYSTEM compat_syscall_entry_pointers
180 #define TRACE_INCLUDE_FILE compat_syscalls_pointers
181 #include <instrumentation/syscalls/headers/compat_syscalls_pointers.h>
182 #undef TRACE_INCLUDE_FILE
183 #undef TRACE_SYSTEM
184 #undef SC_LTTNG_TRACEPOINT_ENUM
185 #undef SC_LTTNG_TRACEPOINT_EVENT_CODE
186 #undef SC_LTTNG_TRACEPOINT_EVENT
187 #undef SC_LTTNG_TRACEPOINT_EVENT_CLASS_NOARGS
188 #undef SC_LTTNG_TRACEPOINT_EVENT_INSTANCE_NOARGS
189 #undef TP_PROBE_CB
190 #undef _TRACE_SYSCALLS_INTEGERS_H
191 #undef _TRACE_SYSCALLS_POINTERS_H
192 #undef LTTNG_SC_COMPAT
193
194 #undef SC_ENTER
195
196 #define SC_EXIT
197
198 #undef sc_exit
199 #define sc_exit(...) __VA_ARGS__
200 #undef sc_in
201 #define sc_in(...)
202 #undef sc_out
203 #define sc_out(...) __VA_ARGS__
204 #undef sc_inout
205 #define sc_inout(...) __VA_ARGS__
206
207 /* Hijack probe callback for system call exit */
208 #define TP_PROBE_CB(_template) &syscall_exit_probe
209 #define SC_LTTNG_TRACEPOINT_EVENT(_name, _proto, _args, _fields) \
210 LTTNG_TRACEPOINT_EVENT(syscall_exit_##_name, PARAMS(_proto), PARAMS(_args), \
211 PARAMS(_fields))
212 #define SC_LTTNG_TRACEPOINT_EVENT_CODE(_name, _proto, _args, _locvar, _code_pre, _fields, _code_post) \
213 LTTNG_TRACEPOINT_EVENT_CODE(syscall_exit_##_name, PARAMS(_proto), PARAMS(_args), \
214 PARAMS(_locvar), PARAMS(_code_pre), PARAMS(_fields), PARAMS(_code_post))
215 #define SC_LTTNG_TRACEPOINT_EVENT_CLASS_NOARGS(_name, _fields) \
216 LTTNG_TRACEPOINT_EVENT_CLASS_NOARGS(syscall_exit_##_name, PARAMS(_fields))
217 #define SC_LTTNG_TRACEPOINT_EVENT_INSTANCE_NOARGS(_template, _name) \
218 LTTNG_TRACEPOINT_EVENT_INSTANCE_NOARGS(syscall_exit_##_template, \
219 syscall_exit_##_name)
220 /* Enumerations only defined at inital inclusion (not here). */
221 #define SC_LTTNG_TRACEPOINT_ENUM(_name, _values)
222 #define TRACE_SYSTEM syscall_exit_integers
223 #define TRACE_INCLUDE_FILE syscalls_integers
224 #include <instrumentation/syscalls/headers/syscalls_integers.h>
225 #undef TRACE_INCLUDE_FILE
226 #undef TRACE_SYSTEM
227 #define TRACE_SYSTEM syscall_exit_pointers
228 #define TRACE_INCLUDE_FILE syscalls_pointers
229 #include <instrumentation/syscalls/headers/syscalls_pointers.h>
230 #undef TRACE_INCLUDE_FILE
231 #undef TRACE_SYSTEM
232 #undef SC_LTTNG_TRACEPOINT_ENUM
233 #undef SC_LTTNG_TRACEPOINT_EVENT_CODE
234 #undef SC_LTTNG_TRACEPOINT_EVENT
235 #undef SC_LTTNG_TRACEPOINT_EVENT_CLASS_NOARGS
236 #undef SC_LTTNG_TRACEPOINT_EVENT_INSTANCE_NOARGS
237 #undef TP_PROBE_CB
238 #undef _TRACE_SYSCALLS_INTEGERS_H
239 #undef _TRACE_SYSCALLS_POINTERS_H
240
241
242 /* Hijack probe callback for compat system call exit */
243 #define TP_PROBE_CB(_template) &syscall_exit_probe
244 #define LTTNG_SC_COMPAT
245 #define SC_LTTNG_TRACEPOINT_EVENT(_name, _proto, _args, _fields) \
246 LTTNG_TRACEPOINT_EVENT(compat_syscall_exit_##_name, PARAMS(_proto), PARAMS(_args), \
247 PARAMS(_fields))
248 #define SC_LTTNG_TRACEPOINT_EVENT_CODE(_name, _proto, _args, _locvar, _code_pre, _fields, _code_post) \
249 LTTNG_TRACEPOINT_EVENT_CODE(compat_syscall_exit_##_name, PARAMS(_proto), PARAMS(_args), \
250 PARAMS(_locvar), PARAMS(_code_pre), PARAMS(_fields), PARAMS(_code_post))
251 #define SC_LTTNG_TRACEPOINT_EVENT_CLASS_NOARGS(_name, _fields) \
252 LTTNG_TRACEPOINT_EVENT_CLASS_NOARGS(compat_syscall_exit_##_name, PARAMS(_fields))
253 #define SC_LTTNG_TRACEPOINT_EVENT_INSTANCE_NOARGS(_template, _name) \
254 LTTNG_TRACEPOINT_EVENT_INSTANCE_NOARGS(compat_syscall_exit_##_template, \
255 compat_syscall_exit_##_name)
256 /* Enumerations only defined at inital inclusion (not here). */
257 #define SC_LTTNG_TRACEPOINT_ENUM(_name, _values)
258 #define TRACE_SYSTEM compat_syscall_exit_integers
259 #define TRACE_INCLUDE_FILE compat_syscalls_integers
260 #include <instrumentation/syscalls/headers/compat_syscalls_integers.h>
261 #undef TRACE_INCLUDE_FILE
262 #undef TRACE_SYSTEM
263 #define TRACE_SYSTEM compat_syscall_exit_pointers
264 #define TRACE_INCLUDE_FILE compat_syscalls_pointers
265 #include <instrumentation/syscalls/headers/compat_syscalls_pointers.h>
266 #undef TRACE_INCLUDE_FILE
267 #undef TRACE_SYSTEM
268 #undef SC_LTTNG_TRACEPOINT_ENUM
269 #undef SC_LTTNG_TRACEPOINT_EVENT_CODE
270 #undef SC_LTTNG_TRACEPOINT_EVENT
271 #undef SC_LTTNG_TRACEPOINT_EVENT_CLASS_NOARGS
272 #undef SC_LTTNG_TRACEPOINT_EVENT_INSTANCE_NOARGS
273 #undef TP_PROBE_CB
274 #undef _TRACE_SYSCALLS_INTEGERS_H
275 #undef _TRACE_SYSCALLS_POINTERS_H
276 #undef LTTNG_SC_COMPAT
277
278 #undef SC_EXIT
279
280 #undef TP_MODULE_NOINIT
281 #undef LTTNG_PACKAGE_BUILD
282 #undef CREATE_TRACE_POINTS
283
284 struct trace_syscall_entry {
285 void *func;
286 const struct lttng_event_desc *desc;
287 const struct lttng_event_field *fields;
288 unsigned int nrargs;
289 };
290
291 #define CREATE_SYSCALL_TABLE
292
293 #define SC_ENTER
294
295 #undef sc_exit
296 #define sc_exit(...)
297
298 #undef TRACE_SYSCALL_TABLE
299 #define TRACE_SYSCALL_TABLE(_template, _name, _nr, _nrargs) \
300 [ _nr ] = { \
301 .func = __event_probe__syscall_entry_##_template, \
302 .nrargs = (_nrargs), \
303 .fields = __event_fields___syscall_entry_##_template, \
304 .desc = &__event_desc___syscall_entry_##_name, \
305 },
306
307 /* Syscall enter tracing table */
308 static const struct trace_syscall_entry sc_table[] = {
309 #include <instrumentation/syscalls/headers/syscalls_integers.h>
310 #include <instrumentation/syscalls/headers/syscalls_pointers.h>
311 };
312
313 #undef TRACE_SYSCALL_TABLE
314 #define TRACE_SYSCALL_TABLE(_template, _name, _nr, _nrargs) \
315 [ _nr ] = { \
316 .func = __event_probe__compat_syscall_entry_##_template, \
317 .nrargs = (_nrargs), \
318 .fields = __event_fields___compat_syscall_entry_##_template, \
319 .desc = &__event_desc___compat_syscall_entry_##_name, \
320 },
321
322 /* Compat syscall enter table */
323 const struct trace_syscall_entry compat_sc_table[] = {
324 #include <instrumentation/syscalls/headers/compat_syscalls_integers.h>
325 #include <instrumentation/syscalls/headers/compat_syscalls_pointers.h>
326 };
327
328 #undef SC_ENTER
329
330 #define SC_EXIT
331
332 #undef sc_exit
333 #define sc_exit(...) __VA_ARGS__
334
335 #undef TRACE_SYSCALL_TABLE
336 #define TRACE_SYSCALL_TABLE(_template, _name, _nr, _nrargs) \
337 [ _nr ] = { \
338 .func = __event_probe__syscall_exit_##_template, \
339 .nrargs = (_nrargs), \
340 .fields = __event_fields___syscall_exit_##_template, \
341 .desc = &__event_desc___syscall_exit_##_name, \
342 },
343
344 /* Syscall exit table */
345 static const struct trace_syscall_entry sc_exit_table[] = {
346 #include <instrumentation/syscalls/headers/syscalls_integers.h>
347 #include <instrumentation/syscalls/headers/syscalls_pointers.h>
348 };
349
350 #undef TRACE_SYSCALL_TABLE
351 #define TRACE_SYSCALL_TABLE(_template, _name, _nr, _nrargs) \
352 [ _nr ] = { \
353 .func = __event_probe__compat_syscall_exit_##_template, \
354 .nrargs = (_nrargs), \
355 .fields = __event_fields___compat_syscall_exit_##_template, \
356 .desc = &__event_desc___compat_syscall_exit_##_name, \
357 },
358
359 /* Compat syscall exit table */
360 const struct trace_syscall_entry compat_sc_exit_table[] = {
361 #include <instrumentation/syscalls/headers/compat_syscalls_integers.h>
362 #include <instrumentation/syscalls/headers/compat_syscalls_pointers.h>
363 };
364
365 #undef SC_EXIT
366
367 #undef CREATE_SYSCALL_TABLE
368
369 struct lttng_syscall_filter {
370 DECLARE_BITMAP(sc, NR_syscalls);
371 DECLARE_BITMAP(sc_compat, NR_compat_syscalls);
372 };
373
374 static void syscall_entry_unknown(struct lttng_event *event,
375 struct pt_regs *regs, unsigned int id)
376 {
377 unsigned long args[UNKNOWN_SYSCALL_NRARGS];
378
379 syscall_get_arguments(current, regs, 0, UNKNOWN_SYSCALL_NRARGS, args);
380 if (unlikely(in_compat_syscall()))
381 __event_probe__compat_syscall_entry_unknown(event, id, args);
382 else
383 __event_probe__syscall_entry_unknown(event, id, args);
384 }
385
386 void syscall_entry_probe(void *__data, struct pt_regs *regs, long id)
387 {
388 struct lttng_channel *chan = __data;
389 struct lttng_event *event, *unknown_event;
390 const struct trace_syscall_entry *table, *entry;
391 size_t table_len;
392
393 if (unlikely(in_compat_syscall())) {
394 struct lttng_syscall_filter *filter;
395
396 filter = lttng_rcu_dereference(chan->sc_filter);
397 if (filter) {
398 if (id < 0 || id >= NR_compat_syscalls
399 || !test_bit(id, filter->sc_compat)) {
400 /* System call filtered out. */
401 return;
402 }
403 }
404 table = compat_sc_table;
405 table_len = ARRAY_SIZE(compat_sc_table);
406 unknown_event = chan->sc_compat_unknown;
407 } else {
408 struct lttng_syscall_filter *filter;
409
410 filter = lttng_rcu_dereference(chan->sc_filter);
411 if (filter) {
412 if (id < 0 || id >= NR_syscalls
413 || !test_bit(id, filter->sc)) {
414 /* System call filtered out. */
415 return;
416 }
417 }
418 table = sc_table;
419 table_len = ARRAY_SIZE(sc_table);
420 unknown_event = chan->sc_unknown;
421 }
422 if (unlikely(id < 0 || id >= table_len)) {
423 syscall_entry_unknown(unknown_event, regs, id);
424 return;
425 }
426 if (unlikely(in_compat_syscall()))
427 event = chan->compat_sc_table[id];
428 else
429 event = chan->sc_table[id];
430 if (unlikely(!event)) {
431 syscall_entry_unknown(unknown_event, regs, id);
432 return;
433 }
434 entry = &table[id];
435 WARN_ON_ONCE(!entry);
436
437 switch (entry->nrargs) {
438 case 0:
439 {
440 void (*fptr)(void *__data) = entry->func;
441
442 fptr(event);
443 break;
444 }
445 case 1:
446 {
447 void (*fptr)(void *__data, unsigned long arg0) = entry->func;
448 unsigned long args[1];
449
450 syscall_get_arguments(current, regs, 0, entry->nrargs, args);
451 fptr(event, args[0]);
452 break;
453 }
454 case 2:
455 {
456 void (*fptr)(void *__data,
457 unsigned long arg0,
458 unsigned long arg1) = entry->func;
459 unsigned long args[2];
460
461 syscall_get_arguments(current, regs, 0, entry->nrargs, args);
462 fptr(event, args[0], args[1]);
463 break;
464 }
465 case 3:
466 {
467 void (*fptr)(void *__data,
468 unsigned long arg0,
469 unsigned long arg1,
470 unsigned long arg2) = entry->func;
471 unsigned long args[3];
472
473 syscall_get_arguments(current, regs, 0, entry->nrargs, args);
474 fptr(event, args[0], args[1], args[2]);
475 break;
476 }
477 case 4:
478 {
479 void (*fptr)(void *__data,
480 unsigned long arg0,
481 unsigned long arg1,
482 unsigned long arg2,
483 unsigned long arg3) = entry->func;
484 unsigned long args[4];
485
486 syscall_get_arguments(current, regs, 0, entry->nrargs, args);
487 fptr(event, args[0], args[1], args[2], args[3]);
488 break;
489 }
490 case 5:
491 {
492 void (*fptr)(void *__data,
493 unsigned long arg0,
494 unsigned long arg1,
495 unsigned long arg2,
496 unsigned long arg3,
497 unsigned long arg4) = entry->func;
498 unsigned long args[5];
499
500 syscall_get_arguments(current, regs, 0, entry->nrargs, args);
501 fptr(event, args[0], args[1], args[2], args[3], args[4]);
502 break;
503 }
504 case 6:
505 {
506 void (*fptr)(void *__data,
507 unsigned long arg0,
508 unsigned long arg1,
509 unsigned long arg2,
510 unsigned long arg3,
511 unsigned long arg4,
512 unsigned long arg5) = entry->func;
513 unsigned long args[6];
514
515 syscall_get_arguments(current, regs, 0, entry->nrargs, args);
516 fptr(event, args[0], args[1], args[2],
517 args[3], args[4], args[5]);
518 break;
519 }
520 default:
521 break;
522 }
523 }
524
525 static void syscall_exit_unknown(struct lttng_event *event,
526 struct pt_regs *regs, int id, long ret)
527 {
528 unsigned long args[UNKNOWN_SYSCALL_NRARGS];
529
530 syscall_get_arguments(current, regs, 0, UNKNOWN_SYSCALL_NRARGS, args);
531 if (unlikely(in_compat_syscall()))
532 __event_probe__compat_syscall_exit_unknown(event, id, ret,
533 args);
534 else
535 __event_probe__syscall_exit_unknown(event, id, ret, args);
536 }
537
538 void syscall_exit_probe(void *__data, struct pt_regs *regs, long ret)
539 {
540 struct lttng_channel *chan = __data;
541 struct lttng_event *event, *unknown_event;
542 const struct trace_syscall_entry *table, *entry;
543 size_t table_len;
544 long id;
545
546 id = syscall_get_nr(current, regs);
547 if (unlikely(in_compat_syscall())) {
548 struct lttng_syscall_filter *filter;
549
550 filter = lttng_rcu_dereference(chan->sc_filter);
551 if (filter) {
552 if (id < 0 || id >= NR_compat_syscalls
553 || !test_bit(id, filter->sc_compat)) {
554 /* System call filtered out. */
555 return;
556 }
557 }
558 table = compat_sc_exit_table;
559 table_len = ARRAY_SIZE(compat_sc_exit_table);
560 unknown_event = chan->compat_sc_exit_unknown;
561 } else {
562 struct lttng_syscall_filter *filter;
563
564 filter = lttng_rcu_dereference(chan->sc_filter);
565 if (filter) {
566 if (id < 0 || id >= NR_syscalls
567 || !test_bit(id, filter->sc)) {
568 /* System call filtered out. */
569 return;
570 }
571 }
572 table = sc_exit_table;
573 table_len = ARRAY_SIZE(sc_exit_table);
574 unknown_event = chan->sc_exit_unknown;
575 }
576 if (unlikely(id < 0 || id >= table_len)) {
577 syscall_exit_unknown(unknown_event, regs, id, ret);
578 return;
579 }
580 if (unlikely(in_compat_syscall()))
581 event = chan->compat_sc_exit_table[id];
582 else
583 event = chan->sc_exit_table[id];
584 if (unlikely(!event)) {
585 syscall_exit_unknown(unknown_event, regs, id, ret);
586 return;
587 }
588 entry = &table[id];
589 WARN_ON_ONCE(!entry);
590
591 switch (entry->nrargs) {
592 case 0:
593 {
594 void (*fptr)(void *__data, long ret) = entry->func;
595
596 fptr(event, ret);
597 break;
598 }
599 case 1:
600 {
601 void (*fptr)(void *__data,
602 long ret,
603 unsigned long arg0) = entry->func;
604 unsigned long args[1];
605
606 syscall_get_arguments(current, regs, 0, entry->nrargs, args);
607 fptr(event, ret, args[0]);
608 break;
609 }
610 case 2:
611 {
612 void (*fptr)(void *__data,
613 long ret,
614 unsigned long arg0,
615 unsigned long arg1) = entry->func;
616 unsigned long args[2];
617
618 syscall_get_arguments(current, regs, 0, entry->nrargs, args);
619 fptr(event, ret, args[0], args[1]);
620 break;
621 }
622 case 3:
623 {
624 void (*fptr)(void *__data,
625 long ret,
626 unsigned long arg0,
627 unsigned long arg1,
628 unsigned long arg2) = entry->func;
629 unsigned long args[3];
630
631 syscall_get_arguments(current, regs, 0, entry->nrargs, args);
632 fptr(event, ret, args[0], args[1], args[2]);
633 break;
634 }
635 case 4:
636 {
637 void (*fptr)(void *__data,
638 long ret,
639 unsigned long arg0,
640 unsigned long arg1,
641 unsigned long arg2,
642 unsigned long arg3) = entry->func;
643 unsigned long args[4];
644
645 syscall_get_arguments(current, regs, 0, entry->nrargs, args);
646 fptr(event, ret, args[0], args[1], args[2], args[3]);
647 break;
648 }
649 case 5:
650 {
651 void (*fptr)(void *__data,
652 long ret,
653 unsigned long arg0,
654 unsigned long arg1,
655 unsigned long arg2,
656 unsigned long arg3,
657 unsigned long arg4) = entry->func;
658 unsigned long args[5];
659
660 syscall_get_arguments(current, regs, 0, entry->nrargs, args);
661 fptr(event, ret, args[0], args[1], args[2], args[3], args[4]);
662 break;
663 }
664 case 6:
665 {
666 void (*fptr)(void *__data,
667 long ret,
668 unsigned long arg0,
669 unsigned long arg1,
670 unsigned long arg2,
671 unsigned long arg3,
672 unsigned long arg4,
673 unsigned long arg5) = entry->func;
674 unsigned long args[6];
675
676 syscall_get_arguments(current, regs, 0, entry->nrargs, args);
677 fptr(event, ret, args[0], args[1], args[2],
678 args[3], args[4], args[5]);
679 break;
680 }
681 default:
682 break;
683 }
684 }
685
686 /*
687 * noinline to diminish caller stack size.
688 * Should be called with sessions lock held.
689 */
690 static
691 int fill_table(const struct trace_syscall_entry *table, size_t table_len,
692 struct lttng_event **chan_table, struct lttng_channel *chan,
693 void *filter, enum sc_type type)
694 {
695 const struct lttng_event_desc *desc;
696 unsigned int i;
697
698 /* Allocate events for each syscall, insert into table */
699 for (i = 0; i < table_len; i++) {
700 struct lttng_kernel_event ev;
701 desc = table[i].desc;
702
703 if (!desc) {
704 /* Unknown syscall */
705 continue;
706 }
707 /*
708 * Skip those already populated by previous failed
709 * register for this channel.
710 */
711 if (chan_table[i])
712 continue;
713 memset(&ev, 0, sizeof(ev));
714 switch (type) {
715 case SC_TYPE_ENTRY:
716 strncpy(ev.name, SYSCALL_ENTRY_STR,
717 LTTNG_KERNEL_SYM_NAME_LEN);
718 break;
719 case SC_TYPE_EXIT:
720 strncpy(ev.name, SYSCALL_EXIT_STR,
721 LTTNG_KERNEL_SYM_NAME_LEN);
722 break;
723 case SC_TYPE_COMPAT_ENTRY:
724 strncpy(ev.name, COMPAT_SYSCALL_ENTRY_STR,
725 LTTNG_KERNEL_SYM_NAME_LEN);
726 break;
727 case SC_TYPE_COMPAT_EXIT:
728 strncpy(ev.name, COMPAT_SYSCALL_EXIT_STR,
729 LTTNG_KERNEL_SYM_NAME_LEN);
730 break;
731 default:
732 BUG_ON(1);
733 break;
734 }
735 strncat(ev.name, desc->name,
736 LTTNG_KERNEL_SYM_NAME_LEN - strlen(ev.name) - 1);
737 ev.name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
738 ev.instrumentation = LTTNG_KERNEL_SYSCALL;
739 chan_table[i] = _lttng_event_create(chan, &ev, filter,
740 desc, ev.instrumentation);
741 WARN_ON_ONCE(!chan_table[i]);
742 if (IS_ERR(chan_table[i])) {
743 /*
744 * If something goes wrong in event registration
745 * after the first one, we have no choice but to
746 * leave the previous events in there, until
747 * deleted by session teardown.
748 */
749 return PTR_ERR(chan_table[i]);
750 }
751 }
752 return 0;
753 }
754
755 /*
756 * Should be called with sessions lock held.
757 */
758 int lttng_syscalls_register(struct lttng_channel *chan, void *filter)
759 {
760 struct lttng_kernel_event ev;
761 int ret;
762
763 wrapper_vmalloc_sync_all();
764
765 if (!chan->sc_table) {
766 /* create syscall table mapping syscall to events */
767 chan->sc_table = kzalloc(sizeof(struct lttng_event *)
768 * ARRAY_SIZE(sc_table), GFP_KERNEL);
769 if (!chan->sc_table)
770 return -ENOMEM;
771 }
772 if (!chan->sc_exit_table) {
773 /* create syscall table mapping syscall to events */
774 chan->sc_exit_table = kzalloc(sizeof(struct lttng_event *)
775 * ARRAY_SIZE(sc_exit_table), GFP_KERNEL);
776 if (!chan->sc_exit_table)
777 return -ENOMEM;
778 }
779
780
781 #ifdef CONFIG_COMPAT
782 if (!chan->compat_sc_table) {
783 /* create syscall table mapping compat syscall to events */
784 chan->compat_sc_table = kzalloc(sizeof(struct lttng_event *)
785 * ARRAY_SIZE(compat_sc_table), GFP_KERNEL);
786 if (!chan->compat_sc_table)
787 return -ENOMEM;
788 }
789
790 if (!chan->compat_sc_exit_table) {
791 /* create syscall table mapping compat syscall to events */
792 chan->compat_sc_exit_table = kzalloc(sizeof(struct lttng_event *)
793 * ARRAY_SIZE(compat_sc_exit_table), GFP_KERNEL);
794 if (!chan->compat_sc_exit_table)
795 return -ENOMEM;
796 }
797 #endif
798 if (!chan->sc_unknown) {
799 const struct lttng_event_desc *desc =
800 &__event_desc___syscall_entry_unknown;
801
802 memset(&ev, 0, sizeof(ev));
803 strncpy(ev.name, desc->name, LTTNG_KERNEL_SYM_NAME_LEN);
804 ev.name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
805 ev.instrumentation = LTTNG_KERNEL_SYSCALL;
806 chan->sc_unknown = _lttng_event_create(chan, &ev, filter,
807 desc,
808 ev.instrumentation);
809 WARN_ON_ONCE(!chan->sc_unknown);
810 if (IS_ERR(chan->sc_unknown)) {
811 return PTR_ERR(chan->sc_unknown);
812 }
813 }
814
815 if (!chan->sc_compat_unknown) {
816 const struct lttng_event_desc *desc =
817 &__event_desc___compat_syscall_entry_unknown;
818
819 memset(&ev, 0, sizeof(ev));
820 strncpy(ev.name, desc->name, LTTNG_KERNEL_SYM_NAME_LEN);
821 ev.name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
822 ev.instrumentation = LTTNG_KERNEL_SYSCALL;
823 chan->sc_compat_unknown = _lttng_event_create(chan, &ev, filter,
824 desc,
825 ev.instrumentation);
826 WARN_ON_ONCE(!chan->sc_unknown);
827 if (IS_ERR(chan->sc_compat_unknown)) {
828 return PTR_ERR(chan->sc_compat_unknown);
829 }
830 }
831
832 if (!chan->compat_sc_exit_unknown) {
833 const struct lttng_event_desc *desc =
834 &__event_desc___compat_syscall_exit_unknown;
835
836 memset(&ev, 0, sizeof(ev));
837 strncpy(ev.name, desc->name, LTTNG_KERNEL_SYM_NAME_LEN);
838 ev.name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
839 ev.instrumentation = LTTNG_KERNEL_SYSCALL;
840 chan->compat_sc_exit_unknown = _lttng_event_create(chan, &ev,
841 filter, desc,
842 ev.instrumentation);
843 WARN_ON_ONCE(!chan->compat_sc_exit_unknown);
844 if (IS_ERR(chan->compat_sc_exit_unknown)) {
845 return PTR_ERR(chan->compat_sc_exit_unknown);
846 }
847 }
848
849 if (!chan->sc_exit_unknown) {
850 const struct lttng_event_desc *desc =
851 &__event_desc___syscall_exit_unknown;
852
853 memset(&ev, 0, sizeof(ev));
854 strncpy(ev.name, desc->name, LTTNG_KERNEL_SYM_NAME_LEN);
855 ev.name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
856 ev.instrumentation = LTTNG_KERNEL_SYSCALL;
857 chan->sc_exit_unknown = _lttng_event_create(chan, &ev, filter,
858 desc, ev.instrumentation);
859 WARN_ON_ONCE(!chan->sc_exit_unknown);
860 if (IS_ERR(chan->sc_exit_unknown)) {
861 return PTR_ERR(chan->sc_exit_unknown);
862 }
863 }
864
865 ret = fill_table(sc_table, ARRAY_SIZE(sc_table),
866 chan->sc_table, chan, filter, SC_TYPE_ENTRY);
867 if (ret)
868 return ret;
869 ret = fill_table(sc_exit_table, ARRAY_SIZE(sc_exit_table),
870 chan->sc_exit_table, chan, filter, SC_TYPE_EXIT);
871 if (ret)
872 return ret;
873
874 #ifdef CONFIG_COMPAT
875 ret = fill_table(compat_sc_table, ARRAY_SIZE(compat_sc_table),
876 chan->compat_sc_table, chan, filter,
877 SC_TYPE_COMPAT_ENTRY);
878 if (ret)
879 return ret;
880 ret = fill_table(compat_sc_exit_table, ARRAY_SIZE(compat_sc_exit_table),
881 chan->compat_sc_exit_table, chan, filter,
882 SC_TYPE_COMPAT_EXIT);
883 if (ret)
884 return ret;
885 #endif
886 if (!chan->sys_enter_registered) {
887 ret = lttng_wrapper_tracepoint_probe_register("sys_enter",
888 (void *) syscall_entry_probe, chan);
889 if (ret)
890 return ret;
891 chan->sys_enter_registered = 1;
892 }
893 /*
894 * We change the name of sys_exit tracepoint due to namespace
895 * conflict with sys_exit syscall entry.
896 */
897 if (!chan->sys_exit_registered) {
898 ret = lttng_wrapper_tracepoint_probe_register("sys_exit",
899 (void *) syscall_exit_probe, chan);
900 if (ret) {
901 WARN_ON_ONCE(lttng_wrapper_tracepoint_probe_unregister("sys_enter",
902 (void *) syscall_entry_probe, chan));
903 return ret;
904 }
905 chan->sys_exit_registered = 1;
906 }
907 return ret;
908 }
909
910 /*
911 * Only called at session destruction.
912 */
913 int lttng_syscalls_unregister(struct lttng_channel *chan)
914 {
915 int ret;
916
917 if (!chan->sc_table)
918 return 0;
919 if (chan->sys_enter_registered) {
920 ret = lttng_wrapper_tracepoint_probe_unregister("sys_exit",
921 (void *) syscall_exit_probe, chan);
922 if (ret)
923 return ret;
924 chan->sys_enter_registered = 0;
925 }
926 if (chan->sys_exit_registered) {
927 ret = lttng_wrapper_tracepoint_probe_unregister("sys_enter",
928 (void *) syscall_entry_probe, chan);
929 if (ret)
930 return ret;
931 chan->sys_exit_registered = 0;
932 }
933 /* lttng_event destroy will be performed by lttng_session_destroy() */
934 kfree(chan->sc_table);
935 kfree(chan->sc_exit_table);
936 #ifdef CONFIG_COMPAT
937 kfree(chan->compat_sc_table);
938 kfree(chan->compat_sc_exit_table);
939 #endif
940 kfree(chan->sc_filter);
941 return 0;
942 }
943
944 static
945 int get_syscall_nr(const char *syscall_name)
946 {
947 int syscall_nr = -1;
948 int i;
949
950 for (i = 0; i < ARRAY_SIZE(sc_table); i++) {
951 const struct trace_syscall_entry *entry;
952 const char *it_name;
953
954 entry = &sc_table[i];
955 if (!entry->desc)
956 continue;
957 it_name = entry->desc->name;
958 it_name += strlen(SYSCALL_ENTRY_STR);
959 if (!strcmp(syscall_name, it_name)) {
960 syscall_nr = i;
961 break;
962 }
963 }
964 return syscall_nr;
965 }
966
967 static
968 int get_compat_syscall_nr(const char *syscall_name)
969 {
970 int syscall_nr = -1;
971 int i;
972
973 for (i = 0; i < ARRAY_SIZE(compat_sc_table); i++) {
974 const struct trace_syscall_entry *entry;
975 const char *it_name;
976
977 entry = &compat_sc_table[i];
978 if (!entry->desc)
979 continue;
980 it_name = entry->desc->name;
981 it_name += strlen(COMPAT_SYSCALL_ENTRY_STR);
982 if (!strcmp(syscall_name, it_name)) {
983 syscall_nr = i;
984 break;
985 }
986 }
987 return syscall_nr;
988 }
989
990 static
991 uint32_t get_sc_tables_len(void)
992 {
993 return ARRAY_SIZE(sc_table) + ARRAY_SIZE(compat_sc_table);
994 }
995
996 int lttng_syscall_filter_enable(struct lttng_channel *chan,
997 const char *name)
998 {
999 int syscall_nr, compat_syscall_nr, ret;
1000 struct lttng_syscall_filter *filter;
1001
1002 WARN_ON_ONCE(!chan->sc_table);
1003
1004 if (!name) {
1005 /* Enable all system calls by removing filter */
1006 if (chan->sc_filter) {
1007 filter = chan->sc_filter;
1008 rcu_assign_pointer(chan->sc_filter, NULL);
1009 synchronize_trace();
1010 kfree(filter);
1011 }
1012 chan->syscall_all = 1;
1013 return 0;
1014 }
1015
1016 if (!chan->sc_filter) {
1017 if (chan->syscall_all) {
1018 /*
1019 * All syscalls are already enabled.
1020 */
1021 return -EEXIST;
1022 }
1023 filter = kzalloc(sizeof(struct lttng_syscall_filter),
1024 GFP_KERNEL);
1025 if (!filter)
1026 return -ENOMEM;
1027 } else {
1028 filter = chan->sc_filter;
1029 }
1030 syscall_nr = get_syscall_nr(name);
1031 compat_syscall_nr = get_compat_syscall_nr(name);
1032 if (syscall_nr < 0 && compat_syscall_nr < 0) {
1033 ret = -ENOENT;
1034 goto error;
1035 }
1036 if (syscall_nr >= 0) {
1037 if (test_bit(syscall_nr, filter->sc)) {
1038 ret = -EEXIST;
1039 goto error;
1040 }
1041 bitmap_set(filter->sc, syscall_nr, 1);
1042 }
1043 if (compat_syscall_nr >= 0) {
1044 if (test_bit(compat_syscall_nr, filter->sc_compat)) {
1045 ret = -EEXIST;
1046 goto error;
1047 }
1048 bitmap_set(filter->sc_compat, compat_syscall_nr, 1);
1049 }
1050 if (!chan->sc_filter)
1051 rcu_assign_pointer(chan->sc_filter, filter);
1052 return 0;
1053
1054 error:
1055 if (!chan->sc_filter)
1056 kfree(filter);
1057 return ret;
1058 }
1059
1060 int lttng_syscall_filter_disable(struct lttng_channel *chan,
1061 const char *name)
1062 {
1063 int syscall_nr, compat_syscall_nr, ret;
1064 struct lttng_syscall_filter *filter;
1065
1066 WARN_ON_ONCE(!chan->sc_table);
1067
1068 if (!chan->sc_filter) {
1069 if (!chan->syscall_all)
1070 return -EEXIST;
1071 filter = kzalloc(sizeof(struct lttng_syscall_filter),
1072 GFP_KERNEL);
1073 if (!filter)
1074 return -ENOMEM;
1075 /* Trace all system calls, then apply disable. */
1076 bitmap_set(filter->sc, 0, NR_syscalls);
1077 bitmap_set(filter->sc_compat, 0, NR_compat_syscalls);
1078 } else {
1079 filter = chan->sc_filter;
1080 }
1081
1082 if (!name) {
1083 /* Fail if all syscalls are already disabled. */
1084 if (bitmap_empty(filter->sc, NR_syscalls)
1085 && bitmap_empty(filter->sc_compat,
1086 NR_compat_syscalls)) {
1087 ret = -EEXIST;
1088 goto error;
1089 }
1090
1091 /* Disable all system calls */
1092 bitmap_clear(filter->sc, 0, NR_syscalls);
1093 bitmap_clear(filter->sc_compat, 0, NR_compat_syscalls);
1094 goto apply_filter;
1095 }
1096 syscall_nr = get_syscall_nr(name);
1097 compat_syscall_nr = get_compat_syscall_nr(name);
1098 if (syscall_nr < 0 && compat_syscall_nr < 0) {
1099 ret = -ENOENT;
1100 goto error;
1101 }
1102 if (syscall_nr >= 0) {
1103 if (!test_bit(syscall_nr, filter->sc)) {
1104 ret = -EEXIST;
1105 goto error;
1106 }
1107 bitmap_clear(filter->sc, syscall_nr, 1);
1108 }
1109 if (compat_syscall_nr >= 0) {
1110 if (!test_bit(compat_syscall_nr, filter->sc_compat)) {
1111 ret = -EEXIST;
1112 goto error;
1113 }
1114 bitmap_clear(filter->sc_compat, compat_syscall_nr, 1);
1115 }
1116 apply_filter:
1117 if (!chan->sc_filter)
1118 rcu_assign_pointer(chan->sc_filter, filter);
1119 chan->syscall_all = 0;
1120 return 0;
1121
1122 error:
1123 if (!chan->sc_filter)
1124 kfree(filter);
1125 return ret;
1126 }
1127
1128 static
1129 const struct trace_syscall_entry *syscall_list_get_entry(loff_t *pos)
1130 {
1131 const struct trace_syscall_entry *entry;
1132 int iter = 0;
1133
1134 for (entry = sc_table;
1135 entry < sc_table + ARRAY_SIZE(sc_table);
1136 entry++) {
1137 if (iter++ >= *pos)
1138 return entry;
1139 }
1140 for (entry = compat_sc_table;
1141 entry < compat_sc_table + ARRAY_SIZE(compat_sc_table);
1142 entry++) {
1143 if (iter++ >= *pos)
1144 return entry;
1145 }
1146 /* End of list */
1147 return NULL;
1148 }
1149
1150 static
1151 void *syscall_list_start(struct seq_file *m, loff_t *pos)
1152 {
1153 return (void *) syscall_list_get_entry(pos);
1154 }
1155
1156 static
1157 void *syscall_list_next(struct seq_file *m, void *p, loff_t *ppos)
1158 {
1159 (*ppos)++;
1160 return (void *) syscall_list_get_entry(ppos);
1161 }
1162
1163 static
1164 void syscall_list_stop(struct seq_file *m, void *p)
1165 {
1166 }
1167
1168 static
1169 int get_sc_table(const struct trace_syscall_entry *entry,
1170 const struct trace_syscall_entry **table,
1171 unsigned int *bitness)
1172 {
1173 if (entry >= sc_table && entry < sc_table + ARRAY_SIZE(sc_table)) {
1174 if (bitness)
1175 *bitness = BITS_PER_LONG;
1176 if (table)
1177 *table = sc_table;
1178 return 0;
1179 }
1180 if (!(entry >= compat_sc_table
1181 && entry < compat_sc_table + ARRAY_SIZE(compat_sc_table))) {
1182 return -EINVAL;
1183 }
1184 if (bitness)
1185 *bitness = 32;
1186 if (table)
1187 *table = compat_sc_table;
1188 return 0;
1189 }
1190
1191 static
1192 int syscall_list_show(struct seq_file *m, void *p)
1193 {
1194 const struct trace_syscall_entry *table, *entry = p;
1195 unsigned int bitness;
1196 unsigned long index;
1197 int ret;
1198 const char *name;
1199
1200 ret = get_sc_table(entry, &table, &bitness);
1201 if (ret)
1202 return ret;
1203 if (!entry->desc)
1204 return 0;
1205 if (table == sc_table) {
1206 index = entry - table;
1207 name = &entry->desc->name[strlen(SYSCALL_ENTRY_STR)];
1208 } else {
1209 index = (entry - table) + ARRAY_SIZE(sc_table);
1210 name = &entry->desc->name[strlen(COMPAT_SYSCALL_ENTRY_STR)];
1211 }
1212 seq_printf(m, "syscall { index = %lu; name = %s; bitness = %u; };\n",
1213 index, name, bitness);
1214 return 0;
1215 }
1216
1217 static
1218 const struct seq_operations lttng_syscall_list_seq_ops = {
1219 .start = syscall_list_start,
1220 .next = syscall_list_next,
1221 .stop = syscall_list_stop,
1222 .show = syscall_list_show,
1223 };
1224
1225 static
1226 int lttng_syscall_list_open(struct inode *inode, struct file *file)
1227 {
1228 return seq_open(file, &lttng_syscall_list_seq_ops);
1229 }
1230
1231 const struct file_operations lttng_syscall_list_fops = {
1232 .owner = THIS_MODULE,
1233 .open = lttng_syscall_list_open,
1234 .read = seq_read,
1235 .llseek = seq_lseek,
1236 .release = seq_release,
1237 };
1238
1239 long lttng_channel_syscall_mask(struct lttng_channel *channel,
1240 struct lttng_kernel_syscall_mask __user *usyscall_mask)
1241 {
1242 uint32_t len, sc_tables_len, bitmask_len;
1243 int ret = 0, bit;
1244 char *tmp_mask;
1245 struct lttng_syscall_filter *filter;
1246
1247 ret = get_user(len, &usyscall_mask->len);
1248 if (ret)
1249 return ret;
1250 sc_tables_len = get_sc_tables_len();
1251 bitmask_len = ALIGN(sc_tables_len, 8) >> 3;
1252 if (len < sc_tables_len) {
1253 return put_user(sc_tables_len, &usyscall_mask->len);
1254 }
1255 /* Array is large enough, we can copy array to user-space. */
1256 tmp_mask = kzalloc(bitmask_len, GFP_KERNEL);
1257 if (!tmp_mask)
1258 return -ENOMEM;
1259 filter = channel->sc_filter;
1260
1261 for (bit = 0; bit < ARRAY_SIZE(sc_table); bit++) {
1262 bool state;
1263
1264 if (channel->sc_table) {
1265 if (filter)
1266 state = test_bit(bit, filter->sc);
1267 else
1268 state = 1;
1269 } else {
1270 state = 0;
1271 }
1272 bt_bitfield_write_be(tmp_mask, char, bit, 1, state);
1273 }
1274 for (; bit < sc_tables_len; bit++) {
1275 bool state;
1276
1277 if (channel->compat_sc_table) {
1278 if (filter)
1279 state = test_bit(bit - ARRAY_SIZE(sc_table),
1280 filter->sc_compat);
1281 else
1282 state = 1;
1283 } else {
1284 state = 0;
1285 }
1286 bt_bitfield_write_be(tmp_mask, char, bit, 1, state);
1287 }
1288 if (copy_to_user(usyscall_mask->mask, tmp_mask, bitmask_len))
1289 ret = -EFAULT;
1290 kfree(tmp_mask);
1291 return ret;
1292 }
1293
1294 int lttng_abi_syscall_list(void)
1295 {
1296 struct file *syscall_list_file;
1297 int file_fd, ret;
1298
1299 file_fd = lttng_get_unused_fd();
1300 if (file_fd < 0) {
1301 ret = file_fd;
1302 goto fd_error;
1303 }
1304
1305 syscall_list_file = anon_inode_getfile("[lttng_syscall_list]",
1306 &lttng_syscall_list_fops,
1307 NULL, O_RDWR);
1308 if (IS_ERR(syscall_list_file)) {
1309 ret = PTR_ERR(syscall_list_file);
1310 goto file_error;
1311 }
1312 ret = lttng_syscall_list_fops.open(NULL, syscall_list_file);
1313 if (ret < 0)
1314 goto open_error;
1315 fd_install(file_fd, syscall_list_file);
1316 return file_fd;
1317
1318 open_error:
1319 fput(syscall_list_file);
1320 file_error:
1321 put_unused_fd(file_fd);
1322 fd_error:
1323 return ret;
1324 }
LTTng 2.0/0.x modules
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