[lttng-ust.git] / src / lib / lttng-ust-fork / ustfork.c

/*
 * SPDX-License-Identifier: LGPL-2.1-only
 *
 * Copyright (C) 2009  Pierre-Marc Fournier
 * Copyright (C) 2011-2012  Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 */

/* Has to be included first to override dlfcn.h */
#include <common/compat/dlfcn.h>

#include <unistd.h>
#include <stdio.h>
#include <signal.h>
#include <sched.h>
#include <stdarg.h>
#include <stdlib.h>
#include <errno.h>

#include <lttng/ust-fork.h>

pid_t fork(void)
{
	static pid_t (*plibc_func)(void) = NULL;
	sigset_t sigset;
	pid_t retval;
	int saved_errno;

	if (plibc_func == NULL) {
		plibc_func = dlsym(RTLD_NEXT, "fork");
		if (plibc_func == NULL) {
			fprintf(stderr, "libustfork: unable to find \"fork\" symbol\n");
			errno = ENOSYS;
			return -1;
		}
	}

	lttng_ust_before_fork(&sigset);
	/* Do the real fork */
	retval = plibc_func();
	saved_errno = errno;
	if (retval == 0) {
		/* child */
		lttng_ust_after_fork_child(&sigset);
	} else {
		lttng_ust_after_fork_parent(&sigset);
	}
	errno = saved_errno;
	return retval;
}

int daemon(int nochdir, int noclose)
{
	static int (*plibc_func)(int nochdir, int noclose) = NULL;
	sigset_t sigset;
	int retval;
	int saved_errno;

	if (plibc_func == NULL) {
		plibc_func = dlsym(RTLD_NEXT, "daemon");
		if (plibc_func == NULL) {
			fprintf(stderr, "libustfork: unable to find \"daemon\" symbol\n");
			errno = ENOSYS;
			return -1;
		}
	}

	lttng_ust_before_fork(&sigset);
	/* Do the real daemon call */
	retval = plibc_func(nochdir, noclose);
	saved_errno = errno;
	if (retval == 0) {
		/* child, parent called _exit() directly */
		lttng_ust_after_fork_child(&sigset);
	} else {
		/* on error in the parent */
		lttng_ust_after_fork_parent(&sigset);
	}
	errno = saved_errno;
	return retval;
}

int setuid(uid_t uid)
{
	static int (*plibc_func)(uid_t uid) = NULL;
	int retval;
	int saved_errno;

	if (plibc_func == NULL) {
		plibc_func = dlsym(RTLD_NEXT, "setuid");
		if (plibc_func == NULL) {
			fprintf(stderr, "libustfork: unable to find \"setuid\" symbol\n");
			errno = ENOSYS;
			return -1;
		}
	}

	/* Do the real setuid */
	retval = plibc_func(uid);
	saved_errno = errno;

	lttng_ust_after_setuid();

	errno = saved_errno;
	return retval;
}

int setgid(gid_t gid)
{
	static int (*plibc_func)(gid_t gid) = NULL;
	int retval;
	int saved_errno;

	if (plibc_func == NULL) {
		plibc_func = dlsym(RTLD_NEXT, "setgid");
		if (plibc_func == NULL) {
			fprintf(stderr, "libustfork: unable to find \"setgid\" symbol\n");
			errno = ENOSYS;
			return -1;
		}
	}

	/* Do the real setgid */
	retval = plibc_func(gid);
	saved_errno = errno;

	lttng_ust_after_setgid();

	errno = saved_errno;
	return retval;
}

int seteuid(uid_t euid)
{
	static int (*plibc_func)(uid_t euid) = NULL;
	int retval;
	int saved_errno;

	if (plibc_func == NULL) {
		plibc_func = dlsym(RTLD_NEXT, "seteuid");
		if (plibc_func == NULL) {
			fprintf(stderr, "libustfork: unable to find \"seteuid\" symbol\n");
			errno = ENOSYS;
			return -1;
		}
	}

	/* Do the real seteuid */
	retval = plibc_func(euid);
	saved_errno = errno;

	lttng_ust_after_seteuid();

	errno = saved_errno;
	return retval;
}

int setegid(gid_t egid)
{
	static int (*plibc_func)(gid_t egid) = NULL;
	int retval;
	int saved_errno;

	if (plibc_func == NULL) {
		plibc_func = dlsym(RTLD_NEXT, "setegid");
		if (plibc_func == NULL) {
			fprintf(stderr, "libustfork: unable to find \"setegid\" symbol\n");
			errno = ENOSYS;
			return -1;
		}
	}

	/* Do the real setegid */
	retval = plibc_func(egid);
	saved_errno = errno;

	lttng_ust_after_setegid();

	errno = saved_errno;
	return retval;
}

int setreuid(uid_t ruid, uid_t euid)
{
	static int (*plibc_func)(uid_t ruid, uid_t euid) = NULL;
	int retval;
	int saved_errno;

	if (plibc_func == NULL) {
		plibc_func = dlsym(RTLD_NEXT, "setreuid");
		if (plibc_func == NULL) {
			fprintf(stderr, "libustfork: unable to find \"setreuid\" symbol\n");
			errno = ENOSYS;
			return -1;
		}
	}

	/* Do the real setreuid */
	retval = plibc_func(ruid, euid);
	saved_errno = errno;

	lttng_ust_after_setreuid();

	errno = saved_errno;
	return retval;
}

int setregid(gid_t rgid, gid_t egid)
{
	static int (*plibc_func)(gid_t rgid, gid_t egid) = NULL;
	int retval;
	int saved_errno;

	if (plibc_func == NULL) {
		plibc_func = dlsym(RTLD_NEXT, "setregid");
		if (plibc_func == NULL) {
			fprintf(stderr, "libustfork: unable to find \"setregid\" symbol\n");
			errno = ENOSYS;
			return -1;
		}
	}

	/* Do the real setregid */
	retval = plibc_func(rgid, egid);
	saved_errno = errno;

	lttng_ust_after_setregid();

	errno = saved_errno;
	return retval;
}

#ifdef __linux__

struct user_desc;

struct ustfork_clone_info {
	int (*fn)(void *);
	void *arg;
	sigset_t sigset;
};

static int clone_fn(void *arg)
{
	struct ustfork_clone_info *info = (struct ustfork_clone_info *) arg;

	/* clone is now done and we are in child */
	lttng_ust_after_fork_child(&info->sigset);
	return info->fn(info->arg);
}

int clone(int (*fn)(void *), void *child_stack, int flags, void *arg, ...)
{
	static int (*plibc_func)(int (*fn)(void *), void *child_stack,
			int flags, void *arg, pid_t *ptid,
			struct user_desc *tls, pid_t *ctid) = NULL;
	/* var args */
	pid_t *ptid;
	struct user_desc *tls;
	pid_t *ctid;
	/* end of var args */
	va_list ap;
	int retval;
	int saved_errno;

	va_start(ap, arg);
	ptid = va_arg(ap, pid_t *);
	tls = va_arg(ap, struct user_desc *);
	ctid = va_arg(ap, pid_t *);
	va_end(ap);

	if (plibc_func == NULL) {
		plibc_func = dlsym(RTLD_NEXT, "clone");
		if (plibc_func == NULL) {
			fprintf(stderr, "libustfork: unable to find \"clone\" symbol.\n");
			errno = ENOSYS;
			return -1;
		}
	}

	if (flags & CLONE_VM) {
		/*
		 * Creating a thread, no need to intervene, just pass on
		 * the arguments.
		 */
		retval = plibc_func(fn, child_stack, flags, arg, ptid,
				tls, ctid);
		saved_errno = errno;
	} else {
		/* Creating a real process, we need to intervene. */
		struct ustfork_clone_info info = { .fn = fn, .arg = arg };

		lttng_ust_before_fork(&info.sigset);
		retval = plibc_func(clone_fn, child_stack, flags, &info,
				ptid, tls, ctid);
		saved_errno = errno;
		/* The child doesn't get here. */
		lttng_ust_after_fork_parent(&info.sigset);
	}
	errno = saved_errno;
	return retval;
}

int setns(int fd, int nstype)
{
	static int (*plibc_func)(int fd, int nstype) = NULL;
	int retval;
	int saved_errno;

	if (plibc_func == NULL) {
		plibc_func = dlsym(RTLD_NEXT, "setns");
		if (plibc_func == NULL) {
			fprintf(stderr, "libustfork: unable to find \"setns\" symbol\n");
			errno = ENOSYS;
			return -1;
		}
	}

	/* Do the real setns */
	retval = plibc_func(fd, nstype);
	saved_errno = errno;

	lttng_ust_after_setns();

	errno = saved_errno;
	return retval;
}

int unshare(int flags)
{
	static int (*plibc_func)(int flags) = NULL;
	int retval;
	int saved_errno;

	if (plibc_func == NULL) {
		plibc_func = dlsym(RTLD_NEXT, "unshare");
		if (plibc_func == NULL) {
			fprintf(stderr, "libustfork: unable to find \"unshare\" symbol\n");
			errno = ENOSYS;
			return -1;
		}
	}

	/* Do the real setns */
	retval = plibc_func(flags);
	saved_errno = errno;

	lttng_ust_after_unshare();

	errno = saved_errno;
	return retval;
}

int setresuid(uid_t ruid, uid_t euid, uid_t suid)
{
	static int (*plibc_func)(uid_t ruid, uid_t euid, uid_t suid) = NULL;
	int retval;
	int saved_errno;

	if (plibc_func == NULL) {
		plibc_func = dlsym(RTLD_NEXT, "setresuid");
		if (plibc_func == NULL) {
			fprintf(stderr, "libustfork: unable to find \"setresuid\" symbol\n");
			errno = ENOSYS;
			return -1;
		}
	}

	/* Do the real setresuid */
	retval = plibc_func(ruid, euid, suid);
	saved_errno = errno;

	lttng_ust_after_setresuid();

	errno = saved_errno;
	return retval;
}

int setresgid(gid_t rgid, gid_t egid, gid_t sgid)
{
	static int (*plibc_func)(gid_t rgid, gid_t egid, gid_t sgid) = NULL;
	int retval;
	int saved_errno;

	if (plibc_func == NULL) {
		plibc_func = dlsym(RTLD_NEXT, "setresgid");
		if (plibc_func == NULL) {
			fprintf(stderr, "libustfork: unable to find \"setresgid\" symbol\n");
			errno = ENOSYS;
			return -1;
		}
	}

	/* Do the real setresgid */
	retval = plibc_func(rgid, egid, sgid);
	saved_errno = errno;

	lttng_ust_after_setresgid();

	errno = saved_errno;
	return retval;
}

#elif defined (__FreeBSD__)

pid_t rfork(int flags)
{
	static pid_t (*plibc_func)(int flags) = NULL;
	sigset_t sigset;
	pid_t retval;
	int saved_errno;

	if (plibc_func == NULL) {
		plibc_func = dlsym(RTLD_NEXT, "rfork");
		if (plibc_func == NULL) {
			fprintf(stderr, "libustfork: unable to find \"rfork\" symbol\n");
			errno = ENOSYS;
			return -1;
		}
	}

	lttng_ust_before_fork(&sigset);
	/* Do the real rfork */
	retval = plibc_func(flags);
	saved_errno = errno;
	if (retval == 0) {
		/* child */
		lttng_ust_after_fork_child(&sigset);
	} else {
		lttng_ust_after_fork_parent(&sigset);
	}
	errno = saved_errno;
	return retval;
}

/*
 * On BSD, no need to override vfork, because it runs in the context of
 * the parent, with parent waiting until execve or exit is executed in
 * the child.
 */

#else
#warning "Unknown OS. You might want to ensure that fork/clone/vfork/fork handling is complete."
#endif
Commit	Line	Data
e822f505	1	/*
c0c0989a MJ	2	* SPDX-License-Identifier: LGPL-2.1-only
c0c0989a MJ	3	*
e822f505	4	* Copyright (C) 2009 Pierre-Marc Fournier
3678c8aa	5	* Copyright (C) 2011-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
2d99476b PMF	6	*/
2d99476b PMF	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>
2d99476b PMF	12	#include <stdio.h>
df793c55	13	#include <signal.h>
616ed36a PMF	14	#include <sched.h>
616ed36a PMF	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) {
e822f505 MD	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;
2d99476b PMF	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 */
2f6150e9 MD	69	retval = plibc_func(nochdir, noclose);
111902ab	70	saved_errno = errno;
2f6150e9 MD	71	if (retval == 0) {
2f6150e9 MD	72	/* child, parent called _exit() directly */
d0c8f180	73	lttng_ust_after_fork_child(&sigset);
2f6150e9 MD	74	} else {
2f6150e9 MD	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 );
616ed36a PMF	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
616ed36a PMF	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) {
e822f505 MD	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 {
e822f505 MD	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,
e822f505 MD	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;
616ed36a PMF	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;
939c89cb MD	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) {
939c89cb MD	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