Commit | Line | Data |
---|---|---|
259b6cb3 MD |
1 | /* |
2 | * lttng-syscalls.c | |
3 | * | |
2faf7d1b | 4 | * LTTng syscall probes. |
259b6cb3 | 5 | * |
886d51a3 MD |
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 | |
259b6cb3 MD |
21 | */ |
22 | ||
23 | #include <linux/module.h> | |
24 | #include <linux/slab.h> | |
6333ace3 | 25 | #include <linux/compat.h> |
abc0446a | 26 | #include <linux/err.h> |
80f87dd2 | 27 | #include <linux/bitmap.h> |
259b6cb3 MD |
28 | #include <asm/ptrace.h> |
29 | #include <asm/syscall.h> | |
30 | ||
3a523f5b | 31 | #include "wrapper/tracepoint.h" |
a90917c3 | 32 | #include "lttng-events.h" |
259b6cb3 | 33 | |
6333ace3 | 34 | #ifndef CONFIG_COMPAT |
bfa949bf MD |
35 | # ifndef is_compat_task |
36 | # define is_compat_task() (0) | |
37 | # endif | |
6333ace3 MD |
38 | #endif |
39 | ||
a93244f8 | 40 | static |
2faf7d1b | 41 | void syscall_entry_probe(void *__data, struct pt_regs *regs, long id); |
259b6cb3 | 42 | |
3a523f5b MD |
43 | /* |
44 | * Forward declarations for old kernels. | |
45 | */ | |
46 | struct mmsghdr; | |
47 | struct rlimit64; | |
48 | struct oldold_utsname; | |
49 | struct old_utsname; | |
50 | struct sel_arg_struct; | |
51 | struct mmap_arg_struct; | |
52 | ||
80f87dd2 MD |
53 | #ifdef IA32_NR_syscalls |
54 | #define NR_compat_syscalls IA32_NR_syscalls | |
55 | #else | |
56 | #define NR_compat_syscalls NR_syscalls | |
57 | #endif | |
58 | ||
f7bdf4db MD |
59 | /* |
60 | * Take care of NOARGS not supported by mainline. | |
61 | */ | |
62 | #define DECLARE_EVENT_CLASS_NOARGS(name, tstruct, assign, print) | |
63 | #define DEFINE_EVENT_NOARGS(template, name) | |
64 | #define TRACE_EVENT_NOARGS(name, struct, assign, print) | |
65 | ||
259b6cb3 MD |
66 | /* |
67 | * Create LTTng tracepoint probes. | |
68 | */ | |
69 | #define LTTNG_PACKAGE_BUILD | |
70 | #define CREATE_TRACE_POINTS | |
2655f9ad | 71 | #define TP_MODULE_NOINIT |
2f804c0a | 72 | #define TRACE_INCLUDE_PATH ../instrumentation/syscalls/headers |
259b6cb3 | 73 | |
a93244f8 MD |
74 | #define PARAMS(args...) args |
75 | ||
259b6cb3 | 76 | /* Hijack probe callback for system calls */ |
a93244f8 | 77 | #undef TP_PROBE_CB |
259b6cb3 | 78 | #define TP_PROBE_CB(_template) &syscall_entry_probe |
a93244f8 MD |
79 | #define SC_TRACE_EVENT(_name, _proto, _args, _struct, _assign, _printk) \ |
80 | TRACE_EVENT(_name, PARAMS(_proto), PARAMS(_args),\ | |
81 | PARAMS(_struct), PARAMS(_assign), PARAMS(_printk)) | |
82 | #define SC_DECLARE_EVENT_CLASS_NOARGS(_name, _struct, _assign, _printk) \ | |
83 | DECLARE_EVENT_CLASS_NOARGS(_name, PARAMS(_struct), PARAMS(_assign),\ | |
84 | PARAMS(_printk)) | |
85 | #define SC_DEFINE_EVENT_NOARGS(_template, _name) \ | |
86 | DEFINE_EVENT_NOARGS(_template, _name) | |
87 | #undef TRACE_SYSTEM | |
88 | #define TRACE_SYSTEM syscalls_integers | |
177b3692 | 89 | #include "instrumentation/syscalls/headers/syscalls_integers.h" |
a93244f8 MD |
90 | #undef TRACE_SYSTEM |
91 | #define TRACE_SYSTEM syscalls_pointers | |
177b3692 | 92 | #include "instrumentation/syscalls/headers/syscalls_pointers.h" |
a93244f8 MD |
93 | #undef TRACE_SYSTEM |
94 | #undef SC_TRACE_EVENT | |
95 | #undef SC_DECLARE_EVENT_CLASS_NOARGS | |
96 | #undef SC_DEFINE_EVENT_NOARGS | |
2f804c0a | 97 | |
a93244f8 | 98 | #define TRACE_SYSTEM syscalls_unknown |
63728b02 | 99 | #include "instrumentation/syscalls/headers/syscalls_unknown.h" |
a93244f8 MD |
100 | #undef TRACE_SYSTEM |
101 | ||
102 | /* For compat syscalls */ | |
103 | #undef _TRACE_SYSCALLS_integers_H | |
104 | #undef _TRACE_SYSCALLS_pointers_H | |
105 | ||
106 | /* Hijack probe callback for system calls */ | |
107 | #undef TP_PROBE_CB | |
108 | #define TP_PROBE_CB(_template) &syscall_entry_probe | |
109 | #define SC_TRACE_EVENT(_name, _proto, _args, _struct, _assign, _printk) \ | |
110 | TRACE_EVENT(compat_##_name, PARAMS(_proto), PARAMS(_args), \ | |
111 | PARAMS(_struct), PARAMS(_assign), \ | |
112 | PARAMS(_printk)) | |
113 | #define SC_DECLARE_EVENT_CLASS_NOARGS(_name, _struct, _assign, _printk) \ | |
114 | DECLARE_EVENT_CLASS_NOARGS(compat_##_name, PARAMS(_struct), \ | |
115 | PARAMS(_assign), PARAMS(_printk)) | |
116 | #define SC_DEFINE_EVENT_NOARGS(_template, _name) \ | |
117 | DEFINE_EVENT_NOARGS(compat_##_template, compat_##_name) | |
118 | #define TRACE_SYSTEM compat_syscalls_integers | |
119 | #include "instrumentation/syscalls/headers/compat_syscalls_integers.h" | |
120 | #undef TRACE_SYSTEM | |
121 | #define TRACE_SYSTEM compat_syscalls_pointers | |
122 | #include "instrumentation/syscalls/headers/compat_syscalls_pointers.h" | |
123 | #undef TRACE_SYSTEM | |
124 | #undef SC_TRACE_EVENT | |
125 | #undef SC_DECLARE_EVENT_CLASS_NOARGS | |
126 | #undef SC_DEFINE_EVENT_NOARGS | |
127 | #undef TP_PROBE_CB | |
259b6cb3 | 128 | |
2655f9ad | 129 | #undef TP_MODULE_NOINIT |
259b6cb3 MD |
130 | #undef LTTNG_PACKAGE_BUILD |
131 | #undef CREATE_TRACE_POINTS | |
132 | ||
a93244f8 MD |
133 | struct trace_syscall_entry { |
134 | void *func; | |
135 | const struct lttng_event_desc *desc; | |
136 | const struct lttng_event_field *fields; | |
137 | unsigned int nrargs; | |
138 | }; | |
139 | ||
140 | #define CREATE_SYSCALL_TABLE | |
141 | ||
259b6cb3 | 142 | #undef TRACE_SYSCALL_TABLE |
f7bdf4db | 143 | #define TRACE_SYSCALL_TABLE(_template, _name, _nr, _nrargs) \ |
259b6cb3 | 144 | [ _nr ] = { \ |
f7bdf4db | 145 | .func = __event_probe__##_template, \ |
259b6cb3 | 146 | .nrargs = (_nrargs), \ |
f7bdf4db MD |
147 | .fields = __event_fields___##_template, \ |
148 | .desc = &__event_desc___##_name, \ | |
259b6cb3 MD |
149 | }, |
150 | ||
49c50022 | 151 | static const struct trace_syscall_entry sc_table[] = { |
177b3692 MD |
152 | #include "instrumentation/syscalls/headers/syscalls_integers.h" |
153 | #include "instrumentation/syscalls/headers/syscalls_pointers.h" | |
259b6cb3 MD |
154 | }; |
155 | ||
a93244f8 MD |
156 | #undef TRACE_SYSCALL_TABLE |
157 | #define TRACE_SYSCALL_TABLE(_template, _name, _nr, _nrargs) \ | |
158 | [ _nr ] = { \ | |
159 | .func = __event_probe__##compat_##_template, \ | |
160 | .nrargs = (_nrargs), \ | |
161 | .fields = __event_fields___##compat_##_template,\ | |
162 | .desc = &__event_desc___##compat_##_name, \ | |
163 | }, | |
164 | ||
165 | /* Create compatibility syscall table */ | |
166 | const struct trace_syscall_entry compat_sc_table[] = { | |
167 | #include "instrumentation/syscalls/headers/compat_syscalls_integers.h" | |
168 | #include "instrumentation/syscalls/headers/compat_syscalls_pointers.h" | |
169 | }; | |
259b6cb3 | 170 | |
a93244f8 | 171 | #undef CREATE_SYSCALL_TABLE |
2faf7d1b | 172 | |
80f87dd2 MD |
173 | struct lttng_syscall_filter { |
174 | DECLARE_BITMAP(sc, NR_syscalls); | |
175 | DECLARE_BITMAP(sc_compat, NR_compat_syscalls); | |
176 | }; | |
177 | ||
a90917c3 | 178 | static void syscall_entry_unknown(struct lttng_event *event, |
f405cfce MD |
179 | struct pt_regs *regs, unsigned int id) |
180 | { | |
181 | unsigned long args[UNKNOWN_SYSCALL_NRARGS]; | |
f405cfce | 182 | |
f405cfce | 183 | syscall_get_arguments(current, regs, 0, UNKNOWN_SYSCALL_NRARGS, args); |
a93244f8 MD |
184 | if (unlikely(is_compat_task())) |
185 | __event_probe__compat_sys_unknown(event, id, args); | |
186 | else | |
187 | __event_probe__sys_unknown(event, id, args); | |
f405cfce MD |
188 | } |
189 | ||
2faf7d1b | 190 | void syscall_entry_probe(void *__data, struct pt_regs *regs, long id) |
259b6cb3 | 191 | { |
a90917c3 MD |
192 | struct lttng_channel *chan = __data; |
193 | struct lttng_event *event, *unknown_event; | |
49c50022 MD |
194 | const struct trace_syscall_entry *table, *entry; |
195 | size_t table_len; | |
259b6cb3 | 196 | |
b76dc1a0 | 197 | if (unlikely(is_compat_task())) { |
80f87dd2 MD |
198 | struct lttng_syscall_filter *filter; |
199 | ||
200 | filter = rcu_dereference(chan->sc_filter); | |
201 | if (filter) { | |
202 | if (id >= NR_compat_syscalls | |
203 | || !test_bit(id, filter->sc_compat)) { | |
204 | /* System call filtered out. */ | |
205 | return; | |
206 | } | |
207 | } | |
49c50022 | 208 | table = compat_sc_table; |
a93244f8 | 209 | table_len = ARRAY_SIZE(compat_sc_table); |
49c50022 MD |
210 | unknown_event = chan->sc_compat_unknown; |
211 | } else { | |
80f87dd2 MD |
212 | struct lttng_syscall_filter *filter; |
213 | ||
214 | filter = rcu_dereference(chan->sc_filter); | |
215 | if (filter) { | |
216 | if (id >= NR_syscalls | |
217 | || !test_bit(id, filter->sc)) { | |
218 | /* System call filtered out. */ | |
219 | return; | |
220 | } | |
221 | } | |
49c50022 MD |
222 | table = sc_table; |
223 | table_len = ARRAY_SIZE(sc_table); | |
224 | unknown_event = chan->sc_unknown; | |
b76dc1a0 | 225 | } |
49c50022 MD |
226 | if (unlikely(id >= table_len)) { |
227 | syscall_entry_unknown(unknown_event, regs, id); | |
259b6cb3 | 228 | return; |
f405cfce | 229 | } |
49c50022 MD |
230 | if (unlikely(is_compat_task())) |
231 | event = chan->compat_sc_table[id]; | |
232 | else | |
233 | event = chan->sc_table[id]; | |
f405cfce | 234 | if (unlikely(!event)) { |
49c50022 | 235 | syscall_entry_unknown(unknown_event, regs, id); |
f405cfce MD |
236 | return; |
237 | } | |
49c50022 | 238 | entry = &table[id]; |
f405cfce | 239 | WARN_ON_ONCE(!entry); |
259b6cb3 MD |
240 | |
241 | switch (entry->nrargs) { | |
242 | case 0: | |
243 | { | |
244 | void (*fptr)(void *__data) = entry->func; | |
245 | ||
246 | fptr(event); | |
247 | break; | |
248 | } | |
249 | case 1: | |
250 | { | |
251 | void (*fptr)(void *__data, unsigned long arg0) = entry->func; | |
252 | unsigned long args[1]; | |
253 | ||
254 | syscall_get_arguments(current, regs, 0, entry->nrargs, args); | |
255 | fptr(event, args[0]); | |
256 | break; | |
257 | } | |
258 | case 2: | |
259 | { | |
260 | void (*fptr)(void *__data, | |
261 | unsigned long arg0, | |
262 | unsigned long arg1) = entry->func; | |
263 | unsigned long args[2]; | |
264 | ||
265 | syscall_get_arguments(current, regs, 0, entry->nrargs, args); | |
266 | fptr(event, args[0], args[1]); | |
267 | break; | |
268 | } | |
269 | case 3: | |
270 | { | |
271 | void (*fptr)(void *__data, | |
272 | unsigned long arg0, | |
273 | unsigned long arg1, | |
274 | unsigned long arg2) = entry->func; | |
275 | unsigned long args[3]; | |
276 | ||
277 | syscall_get_arguments(current, regs, 0, entry->nrargs, args); | |
278 | fptr(event, args[0], args[1], args[2]); | |
279 | break; | |
280 | } | |
281 | case 4: | |
282 | { | |
283 | void (*fptr)(void *__data, | |
284 | unsigned long arg0, | |
285 | unsigned long arg1, | |
286 | unsigned long arg2, | |
287 | unsigned long arg3) = entry->func; | |
288 | unsigned long args[4]; | |
289 | ||
290 | syscall_get_arguments(current, regs, 0, entry->nrargs, args); | |
291 | fptr(event, args[0], args[1], args[2], args[3]); | |
292 | break; | |
293 | } | |
294 | case 5: | |
295 | { | |
296 | void (*fptr)(void *__data, | |
297 | unsigned long arg0, | |
298 | unsigned long arg1, | |
299 | unsigned long arg2, | |
300 | unsigned long arg3, | |
301 | unsigned long arg4) = entry->func; | |
302 | unsigned long args[5]; | |
303 | ||
304 | syscall_get_arguments(current, regs, 0, entry->nrargs, args); | |
305 | fptr(event, args[0], args[1], args[2], args[3], args[4]); | |
306 | break; | |
307 | } | |
308 | case 6: | |
309 | { | |
310 | void (*fptr)(void *__data, | |
311 | unsigned long arg0, | |
312 | unsigned long arg1, | |
313 | unsigned long arg2, | |
314 | unsigned long arg3, | |
315 | unsigned long arg4, | |
316 | unsigned long arg5) = entry->func; | |
317 | unsigned long args[6]; | |
318 | ||
319 | syscall_get_arguments(current, regs, 0, entry->nrargs, args); | |
320 | fptr(event, args[0], args[1], args[2], | |
321 | args[3], args[4], args[5]); | |
322 | break; | |
323 | } | |
324 | default: | |
325 | break; | |
326 | } | |
327 | } | |
328 | ||
2a0c4816 | 329 | /* noinline to diminish caller stack size */ |
49c50022 MD |
330 | static |
331 | int fill_table(const struct trace_syscall_entry *table, size_t table_len, | |
a90917c3 | 332 | struct lttng_event **chan_table, struct lttng_channel *chan, void *filter) |
259b6cb3 | 333 | { |
2a0c4816 | 334 | const struct lttng_event_desc *desc; |
259b6cb3 | 335 | unsigned int i; |
49c50022 MD |
336 | |
337 | /* Allocate events for each syscall, insert into table */ | |
338 | for (i = 0; i < table_len; i++) { | |
339 | struct lttng_kernel_event ev; | |
2a0c4816 | 340 | desc = table[i].desc; |
49c50022 MD |
341 | |
342 | if (!desc) { | |
343 | /* Unknown syscall */ | |
344 | continue; | |
345 | } | |
346 | /* | |
347 | * Skip those already populated by previous failed | |
348 | * register for this channel. | |
349 | */ | |
350 | if (chan_table[i]) | |
351 | continue; | |
352 | memset(&ev, 0, sizeof(ev)); | |
f8695253 MD |
353 | strncpy(ev.name, desc->name, LTTNG_KERNEL_SYM_NAME_LEN); |
354 | ev.name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0'; | |
49c50022 | 355 | ev.instrumentation = LTTNG_KERNEL_NOOP; |
a90917c3 | 356 | chan_table[i] = lttng_event_create(chan, &ev, filter, |
49c50022 | 357 | desc); |
abc0446a MD |
358 | WARN_ON_ONCE(!chan_table[i]); |
359 | if (IS_ERR(chan_table[i])) { | |
49c50022 MD |
360 | /* |
361 | * If something goes wrong in event registration | |
362 | * after the first one, we have no choice but to | |
363 | * leave the previous events in there, until | |
364 | * deleted by session teardown. | |
365 | */ | |
abc0446a | 366 | return PTR_ERR(chan_table[i]); |
49c50022 MD |
367 | } |
368 | } | |
369 | return 0; | |
370 | } | |
371 | ||
a90917c3 | 372 | int lttng_syscalls_register(struct lttng_channel *chan, void *filter) |
49c50022 | 373 | { |
2a0c4816 | 374 | struct lttng_kernel_event ev; |
259b6cb3 MD |
375 | int ret; |
376 | ||
377 | wrapper_vmalloc_sync_all(); | |
259b6cb3 MD |
378 | |
379 | if (!chan->sc_table) { | |
380 | /* create syscall table mapping syscall to events */ | |
a90917c3 | 381 | chan->sc_table = kzalloc(sizeof(struct lttng_event *) |
259b6cb3 MD |
382 | * ARRAY_SIZE(sc_table), GFP_KERNEL); |
383 | if (!chan->sc_table) | |
384 | return -ENOMEM; | |
385 | } | |
386 | ||
49c50022 MD |
387 | #ifdef CONFIG_COMPAT |
388 | if (!chan->compat_sc_table) { | |
389 | /* create syscall table mapping compat syscall to events */ | |
a90917c3 | 390 | chan->compat_sc_table = kzalloc(sizeof(struct lttng_event *) |
a93244f8 | 391 | * ARRAY_SIZE(compat_sc_table), GFP_KERNEL); |
49c50022 MD |
392 | if (!chan->compat_sc_table) |
393 | return -ENOMEM; | |
394 | } | |
395 | #endif | |
f405cfce | 396 | if (!chan->sc_unknown) { |
f405cfce MD |
397 | const struct lttng_event_desc *desc = |
398 | &__event_desc___sys_unknown; | |
2f804c0a | 399 | |
f405cfce | 400 | memset(&ev, 0, sizeof(ev)); |
f8695253 MD |
401 | strncpy(ev.name, desc->name, LTTNG_KERNEL_SYM_NAME_LEN); |
402 | ev.name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0'; | |
f405cfce | 403 | ev.instrumentation = LTTNG_KERNEL_NOOP; |
a90917c3 | 404 | chan->sc_unknown = lttng_event_create(chan, &ev, filter, |
f405cfce | 405 | desc); |
abc0446a MD |
406 | WARN_ON_ONCE(!chan->sc_unknown); |
407 | if (IS_ERR(chan->sc_unknown)) { | |
408 | return PTR_ERR(chan->sc_unknown); | |
f405cfce MD |
409 | } |
410 | } | |
411 | ||
b76dc1a0 | 412 | if (!chan->sc_compat_unknown) { |
b76dc1a0 MD |
413 | const struct lttng_event_desc *desc = |
414 | &__event_desc___compat_sys_unknown; | |
415 | ||
416 | memset(&ev, 0, sizeof(ev)); | |
f8695253 MD |
417 | strncpy(ev.name, desc->name, LTTNG_KERNEL_SYM_NAME_LEN); |
418 | ev.name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0'; | |
b76dc1a0 | 419 | ev.instrumentation = LTTNG_KERNEL_NOOP; |
a90917c3 | 420 | chan->sc_compat_unknown = lttng_event_create(chan, &ev, filter, |
b76dc1a0 | 421 | desc); |
abc0446a MD |
422 | WARN_ON_ONCE(!chan->sc_unknown); |
423 | if (IS_ERR(chan->sc_compat_unknown)) { | |
424 | return PTR_ERR(chan->sc_compat_unknown); | |
b76dc1a0 MD |
425 | } |
426 | } | |
427 | ||
2f804c0a | 428 | if (!chan->sc_exit) { |
2f804c0a MD |
429 | const struct lttng_event_desc *desc = |
430 | &__event_desc___exit_syscall; | |
431 | ||
432 | memset(&ev, 0, sizeof(ev)); | |
f8695253 MD |
433 | strncpy(ev.name, desc->name, LTTNG_KERNEL_SYM_NAME_LEN); |
434 | ev.name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0'; | |
2f804c0a | 435 | ev.instrumentation = LTTNG_KERNEL_NOOP; |
a90917c3 | 436 | chan->sc_exit = lttng_event_create(chan, &ev, filter, |
2f804c0a | 437 | desc); |
abc0446a MD |
438 | WARN_ON_ONCE(!chan->sc_exit); |
439 | if (IS_ERR(chan->sc_exit)) { | |
440 | return PTR_ERR(chan->sc_exit); | |
2f804c0a MD |
441 | } |
442 | } | |
443 | ||
49c50022 MD |
444 | ret = fill_table(sc_table, ARRAY_SIZE(sc_table), |
445 | chan->sc_table, chan, filter); | |
446 | if (ret) | |
447 | return ret; | |
448 | #ifdef CONFIG_COMPAT | |
a93244f8 | 449 | ret = fill_table(compat_sc_table, ARRAY_SIZE(compat_sc_table), |
49c50022 MD |
450 | chan->compat_sc_table, chan, filter); |
451 | if (ret) | |
452 | return ret; | |
453 | #endif | |
80f87dd2 MD |
454 | if (!chan->sys_enter_registered) { |
455 | ret = lttng_wrapper_tracepoint_probe_register("sys_enter", | |
456 | (void *) syscall_entry_probe, chan); | |
457 | if (ret) | |
458 | return ret; | |
459 | chan->sys_enter_registered = 1; | |
460 | } | |
63728b02 MD |
461 | /* |
462 | * We change the name of sys_exit tracepoint due to namespace | |
463 | * conflict with sys_exit syscall entry. | |
464 | */ | |
80f87dd2 MD |
465 | if (!chan->sys_exit_registered) { |
466 | ret = lttng_wrapper_tracepoint_probe_register("sys_exit", | |
467 | (void *) __event_probe__exit_syscall, | |
468 | chan->sc_exit); | |
469 | if (ret) { | |
470 | WARN_ON_ONCE(lttng_wrapper_tracepoint_probe_unregister("sys_enter", | |
471 | (void *) syscall_entry_probe, chan)); | |
472 | return ret; | |
473 | } | |
474 | chan->sys_exit_registered = 1; | |
63728b02 | 475 | } |
259b6cb3 MD |
476 | return ret; |
477 | } | |
478 | ||
479 | /* | |
480 | * Only called at session destruction. | |
481 | */ | |
a90917c3 | 482 | int lttng_syscalls_unregister(struct lttng_channel *chan) |
259b6cb3 MD |
483 | { |
484 | int ret; | |
485 | ||
486 | if (!chan->sc_table) | |
487 | return 0; | |
80f87dd2 MD |
488 | if (chan->sys_enter_registered) { |
489 | ret = lttng_wrapper_tracepoint_probe_unregister("sys_exit", | |
490 | (void *) __event_probe__exit_syscall, | |
491 | chan->sc_exit); | |
492 | if (ret) | |
493 | return ret; | |
494 | chan->sys_enter_registered = 0; | |
495 | } | |
496 | if (chan->sys_exit_registered) { | |
497 | ret = lttng_wrapper_tracepoint_probe_unregister("sys_enter", | |
498 | (void *) syscall_entry_probe, chan); | |
499 | if (ret) | |
500 | return ret; | |
501 | chan->sys_exit_registered = 0; | |
502 | } | |
a90917c3 | 503 | /* lttng_event destroy will be performed by lttng_session_destroy() */ |
259b6cb3 | 504 | kfree(chan->sc_table); |
49c50022 MD |
505 | #ifdef CONFIG_COMPAT |
506 | kfree(chan->compat_sc_table); | |
507 | #endif | |
80f87dd2 MD |
508 | kfree(chan->sc_filter); |
509 | return 0; | |
510 | } | |
511 | ||
512 | static | |
513 | int get_syscall_nr(const char *syscall_name) | |
514 | { | |
515 | int syscall_nr = -1; | |
516 | int i; | |
517 | ||
518 | for (i = 0; i < ARRAY_SIZE(sc_table); i++) { | |
519 | const struct trace_syscall_entry *entry; | |
520 | ||
521 | entry = &sc_table[i]; | |
522 | if (!entry->desc) | |
523 | continue; | |
524 | if (!strcmp(syscall_name, entry->desc->name)) { | |
525 | syscall_nr = i; | |
526 | break; | |
527 | } | |
528 | } | |
529 | return syscall_nr; | |
530 | } | |
531 | ||
532 | static | |
533 | int get_compat_syscall_nr(const char *syscall_name) | |
534 | { | |
535 | int syscall_nr = -1; | |
536 | int i; | |
537 | ||
538 | for (i = 0; i < ARRAY_SIZE(compat_sc_table); i++) { | |
539 | const struct trace_syscall_entry *entry; | |
540 | ||
541 | entry = &compat_sc_table[i]; | |
542 | if (!entry->desc) | |
543 | continue; | |
544 | if (!strcmp(syscall_name, entry->desc->name)) { | |
545 | syscall_nr = i; | |
546 | break; | |
547 | } | |
548 | } | |
549 | return syscall_nr; | |
550 | } | |
551 | ||
552 | int lttng_syscall_filter_enable(struct lttng_channel *chan, | |
553 | const char *name) | |
554 | { | |
555 | int syscall_nr, compat_syscall_nr, ret; | |
556 | struct lttng_syscall_filter *filter; | |
557 | ||
558 | WARN_ON_ONCE(!chan->sc_table); | |
559 | ||
560 | if (!name) { | |
561 | /* Enable all system calls by removing filter */ | |
562 | if (chan->sc_filter) { | |
563 | filter = chan->sc_filter; | |
564 | rcu_assign_pointer(chan->sc_filter, NULL); | |
565 | synchronize_trace(); | |
566 | kfree(filter); | |
567 | } | |
568 | chan->syscall_all = 1; | |
569 | return 0; | |
570 | } | |
571 | ||
572 | if (!chan->sc_filter) { | |
573 | if (chan->syscall_all) { | |
574 | /* | |
575 | * All syscalls are already enabled. | |
576 | */ | |
577 | return -EEXIST; | |
578 | } | |
579 | filter = kzalloc(sizeof(struct lttng_syscall_filter), | |
580 | GFP_KERNEL); | |
581 | if (!filter) | |
582 | return -ENOMEM; | |
583 | } else { | |
584 | filter = chan->sc_filter; | |
585 | } | |
586 | syscall_nr = get_syscall_nr(name); | |
587 | compat_syscall_nr = get_compat_syscall_nr(name); | |
588 | if (syscall_nr < 0 && compat_syscall_nr < 0) { | |
589 | ret = -ENOENT; | |
590 | goto error; | |
591 | } | |
592 | if (syscall_nr >= 0) { | |
593 | if (test_bit(syscall_nr, filter->sc)) { | |
594 | ret = -EEXIST; | |
595 | goto error; | |
596 | } | |
597 | bitmap_set(filter->sc, syscall_nr, 1); | |
598 | } | |
599 | if (compat_syscall_nr >= 0) { | |
600 | if (test_bit(compat_syscall_nr, filter->sc_compat)) { | |
601 | ret = -EEXIST; | |
602 | goto error; | |
603 | } | |
604 | bitmap_set(filter->sc_compat, compat_syscall_nr, 1); | |
605 | } | |
606 | if (!chan->sc_filter) | |
607 | rcu_assign_pointer(chan->sc_filter, filter); | |
608 | return 0; | |
609 | ||
610 | error: | |
611 | if (!chan->sc_filter) | |
612 | kfree(filter); | |
613 | return ret; | |
614 | } | |
615 | ||
616 | int lttng_syscall_filter_disable(struct lttng_channel *chan, | |
617 | const char *name) | |
618 | { | |
619 | int syscall_nr, compat_syscall_nr, ret; | |
620 | struct lttng_syscall_filter *filter; | |
621 | ||
622 | WARN_ON_ONCE(!chan->sc_table); | |
623 | ||
624 | if (!chan->sc_filter) { | |
625 | filter = kzalloc(sizeof(struct lttng_syscall_filter), | |
626 | GFP_KERNEL); | |
627 | if (!filter) | |
628 | return -ENOMEM; | |
629 | /* Trace all system calls, then apply disable. */ | |
630 | bitmap_set(filter->sc, 0, NR_syscalls); | |
631 | bitmap_set(filter->sc_compat, 0, NR_compat_syscalls); | |
632 | } else { | |
633 | filter = chan->sc_filter; | |
634 | } | |
635 | ||
636 | syscall_nr = get_syscall_nr(name); | |
637 | compat_syscall_nr = get_compat_syscall_nr(name); | |
638 | if (syscall_nr < 0 && compat_syscall_nr < 0) { | |
639 | ret = -ENOENT; | |
640 | goto error; | |
641 | } | |
642 | if (syscall_nr >= 0) { | |
643 | if (!test_bit(syscall_nr, chan->sc_filter->sc)) { | |
644 | ret = -EEXIST; | |
645 | goto error; | |
646 | } | |
647 | bitmap_clear(chan->sc_filter->sc, syscall_nr, 1); | |
648 | } | |
649 | if (compat_syscall_nr >= 0) { | |
650 | if (!test_bit(compat_syscall_nr, chan->sc_filter->sc_compat)) { | |
651 | ret = -EEXIST; | |
652 | goto error; | |
653 | } | |
654 | bitmap_clear(chan->sc_filter->sc_compat, compat_syscall_nr, 1); | |
655 | } | |
656 | if (!chan->sc_filter) | |
657 | rcu_assign_pointer(chan->sc_filter, filter); | |
658 | chan->syscall_all = 0; | |
259b6cb3 | 659 | return 0; |
80f87dd2 MD |
660 | |
661 | error: | |
662 | if (!chan->sc_filter) | |
663 | kfree(filter); | |
664 | return ret; | |
259b6cb3 | 665 | } |