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