Commit | Line | Data |
---|---|---|
e822f505 | 1 | /* |
c0c0989a MJ |
2 | * SPDX-License-Identifier: LGPL-2.1-only |
3 | * | |
e822f505 | 4 | * Copyright (C) 2009 Pierre-Marc Fournier |
3678c8aa | 5 | * Copyright (C) 2011-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
2d99476b PMF |
6 | */ |
7 | ||
9d315d6d MJ |
8 | /* Has to be included first to override dlfcn.h */ |
9 | #include <common/compat/dlfcn.h> | |
10 | ||
2d99476b PMF |
11 | #include <unistd.h> |
12 | #include <stdio.h> | |
df793c55 | 13 | #include <signal.h> |
616ed36a PMF |
14 | #include <sched.h> |
15 | #include <stdarg.h> | |
e2a195a6 | 16 | #include <stdlib.h> |
eb2b066f | 17 | #include <errno.h> |
2d99476b | 18 | |
d0c8f180 | 19 | #include <lttng/ust-fork.h> |
e822f505 | 20 | |
2d99476b PMF |
21 | pid_t fork(void) |
22 | { | |
23 | static pid_t (*plibc_func)(void) = NULL; | |
7f0aeeba | 24 | sigset_t sigset; |
2d99476b | 25 | pid_t retval; |
111902ab | 26 | int saved_errno; |
2d99476b | 27 | |
e822f505 | 28 | if (plibc_func == NULL) { |
2d99476b | 29 | plibc_func = dlsym(RTLD_NEXT, "fork"); |
e822f505 MD |
30 | if (plibc_func == NULL) { |
31 | fprintf(stderr, "libustfork: unable to find \"fork\" symbol\n"); | |
3678c8aa | 32 | errno = ENOSYS; |
2c10b7fd | 33 | return -1; |
2d99476b PMF |
34 | } |
35 | } | |
36 | ||
d0c8f180 | 37 | lttng_ust_before_fork(&sigset); |
df793c55 | 38 | /* Do the real fork */ |
2d99476b | 39 | retval = plibc_func(); |
111902ab | 40 | saved_errno = errno; |
e822f505 | 41 | if (retval == 0) { |
df793c55 | 42 | /* child */ |
d0c8f180 | 43 | lttng_ust_after_fork_child(&sigset); |
e822f505 | 44 | } else { |
d0c8f180 | 45 | lttng_ust_after_fork_parent(&sigset); |
df793c55 | 46 | } |
111902ab | 47 | errno = saved_errno; |
2d99476b PMF |
48 | return retval; |
49 | } | |
97b042a3 | 50 | |
2f6150e9 MD |
51 | int daemon(int nochdir, int noclose) |
52 | { | |
53 | static int (*plibc_func)(int nochdir, int noclose) = NULL; | |
54 | sigset_t sigset; | |
55 | int retval; | |
111902ab | 56 | int saved_errno; |
2f6150e9 MD |
57 | |
58 | if (plibc_func == NULL) { | |
59 | plibc_func = dlsym(RTLD_NEXT, "daemon"); | |
60 | if (plibc_func == NULL) { | |
61 | fprintf(stderr, "libustfork: unable to find \"daemon\" symbol\n"); | |
62 | errno = ENOSYS; | |
63 | return -1; | |
64 | } | |
65 | } | |
66 | ||
d0c8f180 | 67 | lttng_ust_before_fork(&sigset); |
2f6150e9 MD |
68 | /* Do the real daemon call */ |
69 | retval = plibc_func(nochdir, noclose); | |
111902ab | 70 | saved_errno = errno; |
2f6150e9 MD |
71 | if (retval == 0) { |
72 | /* child, parent called _exit() directly */ | |
d0c8f180 | 73 | lttng_ust_after_fork_child(&sigset); |
2f6150e9 MD |
74 | } else { |
75 | /* on error in the parent */ | |
d0c8f180 | 76 | lttng_ust_after_fork_parent(&sigset); |
2f6150e9 | 77 | } |
111902ab | 78 | errno = saved_errno; |
2f6150e9 MD |
79 | return retval; |
80 | } | |
81 | ||
fca2f191 MJ |
82 | int setuid(uid_t uid) |
83 | { | |
84 | static int (*plibc_func)(uid_t uid) = NULL; | |
85 | int retval; | |
86 | int saved_errno; | |
87 | ||
88 | if (plibc_func == NULL) { | |
89 | plibc_func = dlsym(RTLD_NEXT, "setuid"); | |
90 | if (plibc_func == NULL) { | |
91 | fprintf(stderr, "libustfork: unable to find \"setuid\" symbol\n"); | |
92 | errno = ENOSYS; | |
93 | return -1; | |
94 | } | |
95 | } | |
96 | ||
97 | /* Do the real setuid */ | |
98 | retval = plibc_func(uid); | |
99 | saved_errno = errno; | |
100 | ||
d0c8f180 | 101 | lttng_ust_after_setuid(); |
fca2f191 MJ |
102 | |
103 | errno = saved_errno; | |
104 | return retval; | |
105 | } | |
106 | ||
107 | int setgid(gid_t gid) | |
108 | { | |
109 | static int (*plibc_func)(gid_t gid) = NULL; | |
110 | int retval; | |
111 | int saved_errno; | |
112 | ||
113 | if (plibc_func == NULL) { | |
114 | plibc_func = dlsym(RTLD_NEXT, "setgid"); | |
115 | if (plibc_func == NULL) { | |
116 | fprintf(stderr, "libustfork: unable to find \"setgid\" symbol\n"); | |
117 | errno = ENOSYS; | |
118 | return -1; | |
119 | } | |
120 | } | |
121 | ||
122 | /* Do the real setgid */ | |
123 | retval = plibc_func(gid); | |
124 | saved_errno = errno; | |
125 | ||
d0c8f180 | 126 | lttng_ust_after_setgid(); |
fca2f191 MJ |
127 | |
128 | errno = saved_errno; | |
129 | return retval; | |
130 | } | |
131 | ||
132 | int seteuid(uid_t euid) | |
133 | { | |
134 | static int (*plibc_func)(uid_t euid) = NULL; | |
135 | int retval; | |
136 | int saved_errno; | |
137 | ||
138 | if (plibc_func == NULL) { | |
139 | plibc_func = dlsym(RTLD_NEXT, "seteuid"); | |
140 | if (plibc_func == NULL) { | |
141 | fprintf(stderr, "libustfork: unable to find \"seteuid\" symbol\n"); | |
142 | errno = ENOSYS; | |
143 | return -1; | |
144 | } | |
145 | } | |
146 | ||
147 | /* Do the real seteuid */ | |
148 | retval = plibc_func(euid); | |
149 | saved_errno = errno; | |
150 | ||
d0c8f180 | 151 | lttng_ust_after_seteuid(); |
fca2f191 MJ |
152 | |
153 | errno = saved_errno; | |
154 | return retval; | |
155 | } | |
156 | ||
157 | int setegid(gid_t egid) | |
158 | { | |
159 | static int (*plibc_func)(gid_t egid) = NULL; | |
160 | int retval; | |
161 | int saved_errno; | |
162 | ||
163 | if (plibc_func == NULL) { | |
164 | plibc_func = dlsym(RTLD_NEXT, "setegid"); | |
165 | if (plibc_func == NULL) { | |
166 | fprintf(stderr, "libustfork: unable to find \"setegid\" symbol\n"); | |
167 | errno = ENOSYS; | |
168 | return -1; | |
169 | } | |
170 | } | |
171 | ||
172 | /* Do the real setegid */ | |
173 | retval = plibc_func(egid); | |
174 | saved_errno = errno; | |
175 | ||
d0c8f180 | 176 | lttng_ust_after_setegid(); |
fca2f191 MJ |
177 | |
178 | errno = saved_errno; | |
179 | return retval; | |
180 | } | |
181 | ||
182 | int setreuid(uid_t ruid, uid_t euid) | |
183 | { | |
184 | static int (*plibc_func)(uid_t ruid, uid_t euid) = NULL; | |
185 | int retval; | |
186 | int saved_errno; | |
187 | ||
188 | if (plibc_func == NULL) { | |
189 | plibc_func = dlsym(RTLD_NEXT, "setreuid"); | |
190 | if (plibc_func == NULL) { | |
191 | fprintf(stderr, "libustfork: unable to find \"setreuid\" symbol\n"); | |
192 | errno = ENOSYS; | |
193 | return -1; | |
194 | } | |
195 | } | |
196 | ||
197 | /* Do the real setreuid */ | |
198 | retval = plibc_func(ruid, euid); | |
199 | saved_errno = errno; | |
200 | ||
d0c8f180 | 201 | lttng_ust_after_setreuid(); |
fca2f191 MJ |
202 | |
203 | errno = saved_errno; | |
204 | return retval; | |
205 | } | |
206 | ||
207 | int setregid(gid_t rgid, gid_t egid) | |
208 | { | |
209 | static int (*plibc_func)(gid_t rgid, gid_t egid) = NULL; | |
210 | int retval; | |
211 | int saved_errno; | |
212 | ||
213 | if (plibc_func == NULL) { | |
214 | plibc_func = dlsym(RTLD_NEXT, "setregid"); | |
215 | if (plibc_func == NULL) { | |
216 | fprintf(stderr, "libustfork: unable to find \"setregid\" symbol\n"); | |
217 | errno = ENOSYS; | |
218 | return -1; | |
219 | } | |
220 | } | |
221 | ||
222 | /* Do the real setregid */ | |
223 | retval = plibc_func(rgid, egid); | |
224 | saved_errno = errno; | |
225 | ||
d0c8f180 | 226 | lttng_ust_after_setregid(); |
fca2f191 MJ |
227 | |
228 | errno = saved_errno; | |
229 | return retval; | |
230 | } | |
231 | ||
939c89cb MD |
232 | #ifdef __linux__ |
233 | ||
234 | struct user_desc; | |
235 | ||
e822f505 | 236 | struct ustfork_clone_info { |
616ed36a PMF |
237 | int (*fn)(void *); |
238 | void *arg; | |
7f0aeeba | 239 | sigset_t sigset; |
616ed36a PMF |
240 | }; |
241 | ||
242 | static int clone_fn(void *arg) | |
243 | { | |
e822f505 | 244 | struct ustfork_clone_info *info = (struct ustfork_clone_info *) arg; |
616ed36a PMF |
245 | |
246 | /* clone is now done and we are in child */ | |
d0c8f180 | 247 | lttng_ust_after_fork_child(&info->sigset); |
616ed36a PMF |
248 | return info->fn(info->arg); |
249 | } | |
250 | ||
251 | int clone(int (*fn)(void *), void *child_stack, int flags, void *arg, ...) | |
252 | { | |
e822f505 MD |
253 | static int (*plibc_func)(int (*fn)(void *), void *child_stack, |
254 | int flags, void *arg, pid_t *ptid, | |
255 | struct user_desc *tls, pid_t *ctid) = NULL; | |
256 | /* var args */ | |
616ed36a PMF |
257 | pid_t *ptid; |
258 | struct user_desc *tls; | |
259 | pid_t *ctid; | |
e822f505 | 260 | /* end of var args */ |
616ed36a | 261 | va_list ap; |
e822f505 | 262 | int retval; |
111902ab | 263 | int saved_errno; |
616ed36a PMF |
264 | |
265 | va_start(ap, arg); | |
266 | ptid = va_arg(ap, pid_t *); | |
267 | tls = va_arg(ap, struct user_desc *); | |
268 | ctid = va_arg(ap, pid_t *); | |
269 | va_end(ap); | |
270 | ||
e822f505 | 271 | if (plibc_func == NULL) { |
616ed36a | 272 | plibc_func = dlsym(RTLD_NEXT, "clone"); |
e822f505 MD |
273 | if (plibc_func == NULL) { |
274 | fprintf(stderr, "libustfork: unable to find \"clone\" symbol.\n"); | |
3678c8aa | 275 | errno = ENOSYS; |
616ed36a PMF |
276 | return -1; |
277 | } | |
278 | } | |
279 | ||
e822f505 MD |
280 | if (flags & CLONE_VM) { |
281 | /* | |
282 | * Creating a thread, no need to intervene, just pass on | |
283 | * the arguments. | |
284 | */ | |
285 | retval = plibc_func(fn, child_stack, flags, arg, ptid, | |
286 | tls, ctid); | |
111902ab | 287 | saved_errno = errno; |
e822f505 MD |
288 | } else { |
289 | /* Creating a real process, we need to intervene. */ | |
3fd2b913 | 290 | struct ustfork_clone_info info = { .fn = fn, .arg = arg }; |
616ed36a | 291 | |
d0c8f180 | 292 | lttng_ust_before_fork(&info.sigset); |
e822f505 MD |
293 | retval = plibc_func(clone_fn, child_stack, flags, &info, |
294 | ptid, tls, ctid); | |
111902ab | 295 | saved_errno = errno; |
e822f505 | 296 | /* The child doesn't get here. */ |
d0c8f180 | 297 | lttng_ust_after_fork_parent(&info.sigset); |
616ed36a | 298 | } |
111902ab | 299 | errno = saved_errno; |
616ed36a PMF |
300 | return retval; |
301 | } | |
939c89cb | 302 | |
735bef47 MJ |
303 | int setns(int fd, int nstype) |
304 | { | |
305 | static int (*plibc_func)(int fd, int nstype) = NULL; | |
306 | int retval; | |
307 | int saved_errno; | |
308 | ||
309 | if (plibc_func == NULL) { | |
310 | plibc_func = dlsym(RTLD_NEXT, "setns"); | |
311 | if (plibc_func == NULL) { | |
312 | fprintf(stderr, "libustfork: unable to find \"setns\" symbol\n"); | |
313 | errno = ENOSYS; | |
314 | return -1; | |
315 | } | |
316 | } | |
317 | ||
318 | /* Do the real setns */ | |
319 | retval = plibc_func(fd, nstype); | |
320 | saved_errno = errno; | |
321 | ||
d0c8f180 | 322 | lttng_ust_after_setns(); |
735bef47 MJ |
323 | |
324 | errno = saved_errno; | |
325 | return retval; | |
326 | } | |
327 | ||
328 | int unshare(int flags) | |
329 | { | |
330 | static int (*plibc_func)(int flags) = NULL; | |
331 | int retval; | |
332 | int saved_errno; | |
333 | ||
334 | if (plibc_func == NULL) { | |
335 | plibc_func = dlsym(RTLD_NEXT, "unshare"); | |
336 | if (plibc_func == NULL) { | |
337 | fprintf(stderr, "libustfork: unable to find \"unshare\" symbol\n"); | |
338 | errno = ENOSYS; | |
339 | return -1; | |
340 | } | |
341 | } | |
342 | ||
343 | /* Do the real setns */ | |
344 | retval = plibc_func(flags); | |
345 | saved_errno = errno; | |
346 | ||
d0c8f180 | 347 | lttng_ust_after_unshare(); |
735bef47 MJ |
348 | |
349 | errno = saved_errno; | |
350 | return retval; | |
351 | } | |
352 | ||
fca2f191 MJ |
353 | int setresuid(uid_t ruid, uid_t euid, uid_t suid) |
354 | { | |
355 | static int (*plibc_func)(uid_t ruid, uid_t euid, uid_t suid) = NULL; | |
356 | int retval; | |
357 | int saved_errno; | |
358 | ||
359 | if (plibc_func == NULL) { | |
360 | plibc_func = dlsym(RTLD_NEXT, "setresuid"); | |
361 | if (plibc_func == NULL) { | |
362 | fprintf(stderr, "libustfork: unable to find \"setresuid\" symbol\n"); | |
363 | errno = ENOSYS; | |
364 | return -1; | |
365 | } | |
366 | } | |
367 | ||
368 | /* Do the real setresuid */ | |
369 | retval = plibc_func(ruid, euid, suid); | |
370 | saved_errno = errno; | |
371 | ||
d0c8f180 | 372 | lttng_ust_after_setresuid(); |
fca2f191 MJ |
373 | |
374 | errno = saved_errno; | |
375 | return retval; | |
376 | } | |
377 | ||
378 | int setresgid(gid_t rgid, gid_t egid, gid_t sgid) | |
379 | { | |
380 | static int (*plibc_func)(gid_t rgid, gid_t egid, gid_t sgid) = NULL; | |
381 | int retval; | |
382 | int saved_errno; | |
383 | ||
384 | if (plibc_func == NULL) { | |
385 | plibc_func = dlsym(RTLD_NEXT, "setresgid"); | |
386 | if (plibc_func == NULL) { | |
387 | fprintf(stderr, "libustfork: unable to find \"setresgid\" symbol\n"); | |
388 | errno = ENOSYS; | |
389 | return -1; | |
390 | } | |
391 | } | |
392 | ||
393 | /* Do the real setresgid */ | |
394 | retval = plibc_func(rgid, egid, sgid); | |
395 | saved_errno = errno; | |
396 | ||
d0c8f180 | 397 | lttng_ust_after_setresgid(); |
fca2f191 MJ |
398 | |
399 | errno = saved_errno; | |
400 | return retval; | |
401 | } | |
402 | ||
939c89cb MD |
403 | #elif defined (__FreeBSD__) |
404 | ||
405 | pid_t rfork(int flags) | |
406 | { | |
e2a195a6 | 407 | static pid_t (*plibc_func)(int flags) = NULL; |
939c89cb MD |
408 | sigset_t sigset; |
409 | pid_t retval; | |
111902ab | 410 | int saved_errno; |
939c89cb MD |
411 | |
412 | if (plibc_func == NULL) { | |
413 | plibc_func = dlsym(RTLD_NEXT, "rfork"); | |
414 | if (plibc_func == NULL) { | |
415 | fprintf(stderr, "libustfork: unable to find \"rfork\" symbol\n"); | |
3678c8aa | 416 | errno = ENOSYS; |
939c89cb MD |
417 | return -1; |
418 | } | |
419 | } | |
420 | ||
d0c8f180 | 421 | lttng_ust_before_fork(&sigset); |
939c89cb | 422 | /* Do the real rfork */ |
e2a195a6 | 423 | retval = plibc_func(flags); |
111902ab | 424 | saved_errno = errno; |
939c89cb MD |
425 | if (retval == 0) { |
426 | /* child */ | |
d0c8f180 | 427 | lttng_ust_after_fork_child(&sigset); |
939c89cb | 428 | } else { |
d0c8f180 | 429 | lttng_ust_after_fork_parent(&sigset); |
939c89cb | 430 | } |
111902ab | 431 | errno = saved_errno; |
939c89cb MD |
432 | return retval; |
433 | } | |
434 | ||
435 | /* | |
436 | * On BSD, no need to override vfork, because it runs in the context of | |
437 | * the parent, with parent waiting until execve or exit is executed in | |
438 | * the child. | |
439 | */ | |
440 | ||
441 | #else | |
442 | #warning "Unknown OS. You might want to ensure that fork/clone/vfork/fork handling is complete." | |
443 | #endif |