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34 * @(#)kern_prot.c 8.6 (Berkeley) 1/21/94
35 * $FreeBSD: src/sys/kern/kern_prot.c,v 1.53.2.9 2002/03/09 05:20:26 dd Exp $
39 * System calls related to processes and protection
42 #include <sys/param.h>
44 #include <sys/systm.h>
45 #include <sys/sysproto.h>
46 #include <sys/kernel.h>
50 #include <sys/malloc.h>
51 #include <sys/pioctl.h>
52 #include <sys/resourcevar.h>
54 #include <sys/lockf.h>
55 #include <sys/spinlock.h>
57 #include <sys/spinlock2.h>
59 static MALLOC_DEFINE(M_CRED, "cred", "credentials");
62 sys_getpid(struct getpid_args *uap)
64 struct proc *p = curproc;
66 uap->sysmsg_fds[0] = p->p_pid;
71 sys_getppid(struct getppid_args *uap)
73 struct proc *p = curproc;
75 uap->sysmsg_result = p->p_ppid;
81 sys_lwp_gettid(struct lwp_gettid_args *uap)
83 struct lwp *lp = curthread->td_lwp;
84 uap->sysmsg_result = lp->lwp_tid;
89 * Get process group ID; note that POSIX getpgrp takes no parameter
92 sys_getpgrp(struct getpgrp_args *uap)
94 struct proc *p = curproc;
96 lwkt_gettoken_shared(&p->p_token);
97 uap->sysmsg_result = p->p_pgrp->pg_id;
98 lwkt_reltoken(&p->p_token);
104 * Get an arbitrary pid's process group id
107 sys_getpgid(struct getpgid_args *uap)
109 struct proc *p = curproc;
119 pt = pfind(uap->pid);
124 lwkt_gettoken_shared(&pt->p_token);
125 uap->sysmsg_result = pt->p_pgrp->pg_id;
126 lwkt_reltoken(&pt->p_token);
134 * Get an arbitrary pid's session id.
137 sys_getsid(struct getsid_args *uap)
139 struct proc *p = curproc;
149 pt = pfind(uap->pid);
154 uap->sysmsg_result = pt->p_session->s_sid;
165 sys_getuid(struct getuid_args *uap)
167 struct ucred *cred = curthread->td_ucred;
169 uap->sysmsg_fds[0] = cred->cr_ruid;
177 sys_geteuid(struct geteuid_args *uap)
179 struct ucred *cred = curthread->td_ucred;
181 uap->sysmsg_result = cred->cr_uid;
189 sys_getgid(struct getgid_args *uap)
191 struct ucred *cred = curthread->td_ucred;
193 uap->sysmsg_fds[0] = cred->cr_rgid;
198 * Get effective group ID. The "egid" is groups[0], and could be obtained
199 * via getgroups. This syscall exists because it is somewhat painful to do
200 * correctly in a library function.
203 sys_getegid(struct getegid_args *uap)
205 struct ucred *cred = curthread->td_ucred;
207 uap->sysmsg_result = cred->cr_groups[0];
212 sys_getgroups(struct getgroups_args *uap)
218 cr = curthread->td_ucred;
219 if ((ngrp = uap->gidsetsize) == 0) {
220 uap->sysmsg_result = cr->cr_ngroups;
223 if (ngrp < cr->cr_ngroups)
225 ngrp = cr->cr_ngroups;
226 error = copyout((caddr_t)cr->cr_groups,
227 (caddr_t)uap->gidset, ngrp * sizeof(gid_t));
229 uap->sysmsg_result = ngrp;
234 sys_lwp_setname(struct lwp_setname_args *uap)
236 struct proc *p = curproc;
238 char buf[LPMAP_MAXTHREADTITLE];
242 if (uap->name != NULL) {
243 error = copyinstr(uap->name, buf, sizeof(buf), &len);
245 if (error != ENAMETOOLONG)
247 buf[sizeof(buf)-1] = 0;
248 len = sizeof(buf) - 1;
255 lwkt_gettoken(&p->p_token);
257 lp = lwpfind(p, uap->tid);
259 lwkt_gettoken(&lp->lwp_token);
260 if (lp->lwp_lpmap == NULL)
263 bcopy(buf, lp->lwp_lpmap->thread_title, len);
264 lwkt_reltoken(&lp->lwp_token);
271 lwkt_reltoken(&p->p_token);
277 sys_setsid(struct setsid_args *uap)
279 struct proc *p = curproc;
280 struct pgrp *pg = NULL;
283 lwkt_gettoken(&p->p_token);
284 if (p->p_pgid == p->p_pid || (pg = pgfind(p->p_pid)) != NULL) {
289 enterpgrp(p, p->p_pid, 1);
290 uap->sysmsg_result = p->p_pid;
293 lwkt_reltoken(&p->p_token);
298 * set process group (setpgid/old setpgrp)
300 * caller does setpgid(targpid, targpgid)
302 * pid must be caller or child of caller (ESRCH)
304 * pid must be in same session (EPERM)
305 * pid can't have done an exec (EACCES)
307 * there must exist some pid in same session having pgid (EPERM)
308 * pid must not be session leader (EPERM)
311 sys_setpgid(struct setpgid_args *uap)
313 struct proc *curp = curproc;
314 struct proc *targp; /* target process */
315 struct pgrp *pgrp = NULL; /* target pgrp */
321 if (uap->pid != 0 && uap->pid != curp->p_pid) {
322 if ((targp = pfind(uap->pid)) == NULL || !inferior(targp)) {
329 lwkt_gettoken(&targp->p_token);
330 /* targp now referenced and its token is held */
332 if (targp->p_pgrp == NULL ||
333 targp->p_session != curp->p_session) {
337 if (targp->p_flags & P_EXEC) {
344 lwkt_gettoken(&targp->p_token);
346 if (SESS_LEADER(targp)) {
350 if (uap->pgid == 0) {
351 uap->pgid = targp->p_pid;
352 } else if (uap->pgid != targp->p_pid) {
353 if ((pgrp = pgfind(uap->pgid)) == NULL ||
354 pgrp->pg_session != curp->p_session) {
359 error = enterpgrp(targp, uap->pgid, 0);
364 lwkt_reltoken(&targp->p_token);
371 * Use the clause in B.4.2.2 that allows setuid/setgid to be 4.2/4.3BSD
372 * compatible. It says that setting the uid/gid to euid/egid is a special
373 * case of "appropriate privilege". Once the rules are expanded out, this
374 * basically means that setuid(nnn) sets all three id's, in all permitted
375 * cases unless _POSIX_SAVED_IDS is enabled. In that case, setuid(getuid())
376 * does not set the saved id - this is dangerous for traditional BSD
377 * programs. For this reason, we *really* do not want to set
378 * _POSIX_SAVED_IDS and do not want to clear POSIX_APPENDIX_B_4_2_2.
380 #define POSIX_APPENDIX_B_4_2_2
383 sys_setuid(struct setuid_args *uap)
385 struct proc *p = curproc;
390 lwkt_gettoken(&p->p_token);
394 * See if we have "permission" by POSIX 1003.1 rules.
396 * Note that setuid(geteuid()) is a special case of
397 * "appropriate privileges" in appendix B.4.2.2. We need
398 * to use this clause to be compatible with traditional BSD
399 * semantics. Basically, it means that "setuid(xx)" sets all
400 * three id's (assuming you have privs).
402 * Notes on the logic. We do things in three steps.
403 * 1: We determine if the euid is going to change, and do EPERM
404 * right away. We unconditionally change the euid later if this
405 * test is satisfied, simplifying that part of the logic.
406 * 2: We determine if the real and/or saved uid's are going to
407 * change. Determined by compile options.
408 * 3: Change euid last. (after tests in #2 for "appropriate privs")
411 if (uid != cr->cr_ruid && /* allow setuid(getuid()) */
412 #ifdef _POSIX_SAVED_IDS
413 uid != crc->cr_svuid && /* allow setuid(saved gid) */
415 #ifdef POSIX_APPENDIX_B_4_2_2 /* Use BSD-compat clause from B.4.2.2 */
416 uid != cr->cr_uid && /* allow setuid(geteuid()) */
418 (error = priv_check_cred(cr, PRIV_CRED_SETUID, 0)))
421 #ifdef _POSIX_SAVED_IDS
423 * Do we have "appropriate privileges" (are we root or uid == euid)
424 * If so, we are changing the real uid and/or saved uid.
427 #ifdef POSIX_APPENDIX_B_4_2_2 /* Use the clause from B.4.2.2 */
430 priv_check_cred(cr, PRIV_CRED_SETUID, 0) == 0) /* we are using privs */
434 * Set the real uid and transfer proc count to new user.
436 if (uid != cr->cr_ruid) {
437 cr = change_ruid(uid);
443 * XXX always set saved uid even if not _POSIX_SAVED_IDS, as
444 * the security of seteuid() depends on it. B.4.2.2 says it
445 * is important that we should do this.
447 if (cr->cr_svuid != uid) {
455 * In all permitted cases, we are changing the euid.
456 * Copy credentials so other references do not see our changes.
458 if (cr->cr_uid != uid) {
464 lwkt_reltoken(&p->p_token);
469 sys_seteuid(struct seteuid_args *uap)
471 struct proc *p = curproc;
476 lwkt_gettoken(&p->p_token);
479 if (euid != cr->cr_ruid && /* allow seteuid(getuid()) */
480 euid != cr->cr_svuid && /* allow seteuid(saved uid) */
481 (error = priv_check_cred(cr, PRIV_CRED_SETEUID, 0))) {
482 lwkt_reltoken(&p->p_token);
487 * Everything's okay, do it. Copy credentials so other references do
488 * not see our changes.
490 if (cr->cr_uid != euid) {
494 lwkt_reltoken(&p->p_token);
499 sys_setgid(struct setgid_args *uap)
501 struct proc *p = curproc;
506 lwkt_gettoken(&p->p_token);
510 * See if we have "permission" by POSIX 1003.1 rules.
512 * Note that setgid(getegid()) is a special case of
513 * "appropriate privileges" in appendix B.4.2.2. We need
514 * to use this clause to be compatible with traditional BSD
515 * semantics. Basically, it means that "setgid(xx)" sets all
516 * three id's (assuming you have privs).
518 * For notes on the logic here, see setuid() above.
521 if (gid != cr->cr_rgid && /* allow setgid(getgid()) */
522 #ifdef _POSIX_SAVED_IDS
523 gid != cr->cr_svgid && /* allow setgid(saved gid) */
525 #ifdef POSIX_APPENDIX_B_4_2_2 /* Use BSD-compat clause from B.4.2.2 */
526 gid != cr->cr_groups[0] && /* allow setgid(getegid()) */
528 (error = priv_check_cred(cr, PRIV_CRED_SETGID, 0))) {
532 #ifdef _POSIX_SAVED_IDS
534 * Do we have "appropriate privileges" (are we root or gid == egid)
535 * If so, we are changing the real uid and saved gid.
538 #ifdef POSIX_APPENDIX_B_4_2_2 /* use the clause from B.4.2.2 */
539 gid == cr->cr_groups[0] ||
541 priv_check_cred(cr, PRIV_CRED_SETGID, 0) == 0) /* we are using privs */
547 if (cr->cr_rgid != gid) {
555 * XXX always set saved gid even if not _POSIX_SAVED_IDS, as
556 * the security of setegid() depends on it. B.4.2.2 says it
557 * is important that we should do this.
559 if (cr->cr_svgid != gid) {
566 * In all cases permitted cases, we are changing the egid.
567 * Copy credentials so other references do not see our changes.
569 if (cr->cr_groups[0] != gid) {
571 cr->cr_groups[0] = gid;
576 lwkt_reltoken(&p->p_token);
581 sys_setegid(struct setegid_args *uap)
583 struct proc *p = curproc;
588 lwkt_gettoken(&p->p_token);
591 if (egid != cr->cr_rgid && /* allow setegid(getgid()) */
592 egid != cr->cr_svgid && /* allow setegid(saved gid) */
593 (error = priv_check_cred(cr, PRIV_CRED_SETEGID, 0))) {
596 if (cr->cr_groups[0] != egid) {
598 cr->cr_groups[0] = egid;
603 lwkt_reltoken(&p->p_token);
608 sys_setgroups(struct setgroups_args *uap)
610 struct proc *p = curproc;
615 lwkt_gettoken(&p->p_token);
618 if ((error = priv_check_cred(cr, PRIV_CRED_SETGROUPS, 0)))
620 ngrp = uap->gidsetsize;
621 if (ngrp > NGROUPS) {
626 * XXX A little bit lazy here. We could test if anything has
627 * changed before cratom() and setting P_SUGID.
632 * setgroups(0, NULL) is a legitimate way of clearing the
633 * groups vector on non-BSD systems (which generally do not
634 * have the egid in the groups[0]). We risk security holes
635 * when running non-BSD software if we do not do the same.
639 error = copyin(uap->gidset, cr->cr_groups,
640 ngrp * sizeof(gid_t));
643 cr->cr_ngroups = ngrp;
648 lwkt_reltoken(&p->p_token);
653 sys_setreuid(struct setreuid_args *uap)
655 struct proc *p = curproc;
660 lwkt_gettoken(&p->p_token);
665 if (((ruid != (uid_t)-1 && ruid != cr->cr_ruid &&
666 ruid != cr->cr_svuid) ||
667 (euid != (uid_t)-1 && euid != cr->cr_uid &&
668 euid != cr->cr_ruid && euid != cr->cr_svuid)) &&
669 (error = priv_check_cred(cr, PRIV_CRED_SETREUID, 0)) != 0) {
673 if (euid != (uid_t)-1 && cr->cr_uid != euid) {
674 cr = change_euid(euid);
677 if (ruid != (uid_t)-1 && cr->cr_ruid != ruid) {
678 cr = change_ruid(ruid);
681 if ((ruid != (uid_t)-1 || cr->cr_uid != cr->cr_ruid) &&
682 cr->cr_svuid != cr->cr_uid) {
684 cr->cr_svuid = cr->cr_uid;
689 lwkt_reltoken(&p->p_token);
694 sys_setregid(struct setregid_args *uap)
696 struct proc *p = curproc;
701 lwkt_gettoken(&p->p_token);
706 if (((rgid != (gid_t)-1 && rgid != cr->cr_rgid &&
707 rgid != cr->cr_svgid) ||
708 (egid != (gid_t)-1 && egid != cr->cr_groups[0] &&
709 egid != cr->cr_rgid && egid != cr->cr_svgid)) &&
710 (error = priv_check_cred(cr, PRIV_CRED_SETREGID, 0)) != 0) {
714 if (egid != (gid_t)-1 && cr->cr_groups[0] != egid) {
716 cr->cr_groups[0] = egid;
719 if (rgid != (gid_t)-1 && cr->cr_rgid != rgid) {
724 if ((rgid != (gid_t)-1 || cr->cr_groups[0] != cr->cr_rgid) &&
725 cr->cr_svgid != cr->cr_groups[0]) {
727 cr->cr_svgid = cr->cr_groups[0];
732 lwkt_reltoken(&p->p_token);
737 * setresuid(ruid, euid, suid) is like setreuid except control over the
738 * saved uid is explicit.
741 sys_setresuid(struct setresuid_args *uap)
743 struct proc *p = curproc;
745 uid_t ruid, euid, suid;
748 lwkt_gettoken(&p->p_token);
754 if (((ruid != (uid_t)-1 && ruid != cr->cr_ruid &&
755 ruid != cr->cr_svuid && ruid != cr->cr_uid) ||
756 (euid != (uid_t)-1 && euid != cr->cr_ruid &&
757 euid != cr->cr_svuid && euid != cr->cr_uid) ||
758 (suid != (uid_t)-1 && suid != cr->cr_ruid &&
759 suid != cr->cr_svuid && suid != cr->cr_uid)) &&
760 (error = priv_check_cred(cr, PRIV_CRED_SETRESUID, 0)) != 0) {
763 if (euid != (uid_t)-1 && cr->cr_uid != euid) {
764 cr = change_euid(euid);
767 if (ruid != (uid_t)-1 && cr->cr_ruid != ruid) {
768 cr = change_ruid(ruid);
771 if (suid != (uid_t)-1 && cr->cr_svuid != suid) {
778 lwkt_reltoken(&p->p_token);
783 * setresgid(rgid, egid, sgid) is like setregid except control over the
784 * saved gid is explicit.
787 sys_setresgid(struct setresgid_args *uap)
789 struct proc *p = curproc;
791 gid_t rgid, egid, sgid;
794 lwkt_gettoken(&p->p_token);
799 if (((rgid != (gid_t)-1 && rgid != cr->cr_rgid &&
800 rgid != cr->cr_svgid && rgid != cr->cr_groups[0]) ||
801 (egid != (gid_t)-1 && egid != cr->cr_rgid &&
802 egid != cr->cr_svgid && egid != cr->cr_groups[0]) ||
803 (sgid != (gid_t)-1 && sgid != cr->cr_rgid &&
804 sgid != cr->cr_svgid && sgid != cr->cr_groups[0])) &&
805 (error = priv_check_cred(cr, PRIV_CRED_SETRESGID, 0)) != 0) {
809 if (egid != (gid_t)-1 && cr->cr_groups[0] != egid) {
811 cr->cr_groups[0] = egid;
814 if (rgid != (gid_t)-1 && cr->cr_rgid != rgid) {
819 if (sgid != (gid_t)-1 && cr->cr_svgid != sgid) {
826 lwkt_reltoken(&p->p_token);
831 sys_getresuid(struct getresuid_args *uap)
834 int error1 = 0, error2 = 0, error3 = 0;
837 * copyout's can fault synchronously so we cannot use a shared
840 cr = curthread->td_ucred;
842 error1 = copyout((caddr_t)&cr->cr_ruid,
843 (caddr_t)uap->ruid, sizeof(cr->cr_ruid));
845 error2 = copyout((caddr_t)&cr->cr_uid,
846 (caddr_t)uap->euid, sizeof(cr->cr_uid));
848 error3 = copyout((caddr_t)&cr->cr_svuid,
849 (caddr_t)uap->suid, sizeof(cr->cr_svuid));
850 return error1 ? error1 : (error2 ? error2 : error3);
854 sys_getresgid(struct getresgid_args *uap)
857 int error1 = 0, error2 = 0, error3 = 0;
859 cr = curthread->td_ucred;
861 error1 = copyout(&cr->cr_rgid, uap->rgid,
862 sizeof(cr->cr_rgid));
864 error2 = copyout(&cr->cr_groups[0], uap->egid,
865 sizeof(cr->cr_groups[0]));
867 error3 = copyout(&cr->cr_svgid, uap->sgid,
868 sizeof(cr->cr_svgid));
869 return error1 ? error1 : (error2 ? error2 : error3);
874 * NOTE: OpenBSD sets a P_SUGIDEXEC flag set at execve() time,
875 * we use P_SUGID because we consider changing the owners as
876 * "tainting" as well.
877 * This is significant for procs that start as root and "become"
878 * a user without an exec - programs cannot know *everything*
879 * that libc *might* have put in their data segment.
882 sys_issetugid(struct issetugid_args *uap)
884 uap->sysmsg_result = (curproc->p_flags & P_SUGID) ? 1 : 0;
889 * Check if gid is a member of the group set.
892 groupmember(gid_t gid, struct ucred *cred)
897 egp = &(cred->cr_groups[cred->cr_ngroups]);
898 for (gp = cred->cr_groups; gp < egp; gp++) {
906 * Test whether the specified credentials have the privilege
909 * A kernel thread without a process context is assumed to have
910 * the privilege in question. In situations where the caller always
911 * expect a cred to exist, the cred should be passed separately and
912 * priv_check_cred() should be used instead of priv_check().
914 * Returns 0 or error.
917 priv_check(struct thread *td, int priv)
919 if (td->td_lwp != NULL)
920 return priv_check_cred(td->td_ucred, priv, 0);
925 * Check a credential for privilege.
927 * A non-null credential is expected unless NULL_CRED_OKAY is set.
930 priv_check_cred(struct ucred *cred, int priv, int flags)
934 KASSERT(PRIV_VALID(priv), ("priv_check_cred: invalid privilege"));
936 KASSERT(cred != NULL || (flags & NULL_CRED_OKAY),
937 ("priv_check_cred: NULL cred!"));
940 if (flags & NULL_CRED_OKAY)
945 if (cred->cr_uid != 0)
948 error = prison_priv_check(cred, priv);
952 /* NOTE: accounting for suser access (p_acflag/ASU) removed */
957 * Return zero if p1 can fondle p2, return errno (EPERM/ESRCH) otherwise.
960 p_trespass(struct ucred *cr1, struct ucred *cr2)
964 if (!PRISON_CHECK(cr1, cr2))
966 if (cr1->cr_ruid == cr2->cr_ruid)
968 if (cr1->cr_uid == cr2->cr_ruid)
970 if (cr1->cr_ruid == cr2->cr_uid)
972 if (cr1->cr_uid == cr2->cr_uid)
974 if (priv_check_cred(cr1, PRIV_PROC_TRESPASS, 0) == 0)
980 _crinit(struct ucred *cr)
986 crinit(struct ucred *cr)
988 bzero(cr, sizeof(*cr));
993 * Allocate a zeroed cred structure.
1000 cr = kmalloc(sizeof(*cr), M_CRED, M_WAITOK|M_ZERO);
1006 * Claim another reference to a ucred structure. Can be used with special
1009 * It must be possible to call this routine with spinlocks held, meaning
1010 * that this routine itself cannot obtain a spinlock.
1013 crhold(struct ucred *cr)
1015 if (cr != NOCRED && cr != FSCRED)
1016 atomic_add_long(&cr->cr_ref, 1);
1021 * Drop a reference from the cred structure, free it if the reference count
1024 * NOTE: because we used atomic_add_int() above, without a spinlock, we
1025 * must also use atomic_subtract_int() below. A spinlock is required
1026 * in crfree() to handle multiple callers racing the refcount to 0.
1029 crfree(struct ucred *cr)
1031 if (cr->cr_ref <= 0)
1032 panic("Freeing already free credential! %p", cr);
1033 if (atomic_fetchadd_long(&cr->cr_ref, -1) == 1) {
1035 * Some callers of crget(), such as nfs_statfs(),
1036 * allocate a temporary credential, but don't
1037 * allocate a uidinfo structure.
1039 if (cr->cr_uidinfo != NULL) {
1040 uidrop(cr->cr_uidinfo);
1041 cr->cr_uidinfo = NULL;
1043 if (cr->cr_ruidinfo != NULL) {
1044 uidrop(cr->cr_ruidinfo);
1045 cr->cr_ruidinfo = NULL;
1049 * Destroy empty prisons
1052 prison_free(cr->cr_prison);
1053 cr->cr_prison = NULL; /* safety */
1055 kfree((caddr_t)cr, M_CRED);
1060 * Atomize a cred structure so it can be modified without polluting
1061 * other references to it.
1063 * MPSAFE (however, *pcr must be stable)
1066 cratom(struct ucred **pcr)
1068 struct ucred *oldcr;
1069 struct ucred *newcr;
1072 if (oldcr->cr_ref == 1)
1074 newcr = crget(); /* this might block */
1075 oldcr = *pcr; /* re-cache after potentially blocking */
1077 uihold(newcr->cr_uidinfo);
1078 uihold(newcr->cr_ruidinfo);
1080 prison_hold(newcr->cr_prison);
1089 * Called with a modifying token held, but must still obtain p_spin to
1090 * actually replace p_ucred to handle races against syscall entry from
1091 * other threads which cache p_ucred->td_ucred.
1093 * (the threads will only get the spin-lock, and they only need to in
1094 * the case where td_ucred != p_ucred so this is optimal).
1097 cratom_proc(struct proc *p)
1099 struct ucred *oldcr;
1100 struct ucred *newcr;
1103 if (oldcr->cr_ref == 1)
1106 newcr = crget(); /* this might block */
1107 oldcr = p->p_ucred; /* so re-cache oldcr (do not re-test) */
1109 uihold(newcr->cr_uidinfo);
1110 uihold(newcr->cr_ruidinfo);
1112 prison_hold(newcr->cr_prison);
1115 spin_lock(&p->p_spin);
1117 spin_unlock(&p->p_spin);
1124 * Dup cred struct to a new held one.
1127 crdup(struct ucred *cr)
1129 struct ucred *newcr;
1133 uihold(newcr->cr_uidinfo);
1134 uihold(newcr->cr_ruidinfo);
1136 prison_hold(newcr->cr_prison);
1142 * Fill in a struct xucred based on a struct ucred.
1145 cru2x(struct ucred *cr, struct xucred *xcr)
1148 bzero(xcr, sizeof(*xcr));
1149 xcr->cr_version = XUCRED_VERSION;
1150 xcr->cr_uid = cr->cr_uid;
1151 xcr->cr_ngroups = cr->cr_ngroups;
1152 bcopy(cr->cr_groups, xcr->cr_groups, sizeof(cr->cr_groups));
1156 * Get login name, if available.
1159 sys_getlogin(struct getlogin_args *uap)
1161 struct proc *p = curproc;
1162 char buf[MAXLOGNAME];
1165 if (uap->namelen > MAXLOGNAME) /* namelen is unsigned */
1166 uap->namelen = MAXLOGNAME;
1167 bzero(buf, sizeof(buf));
1168 lwkt_gettoken_shared(&p->p_token);
1169 bcopy(p->p_pgrp->pg_session->s_login, buf, uap->namelen);
1170 lwkt_reltoken(&p->p_token);
1172 error = copyout(buf, uap->namebuf, uap->namelen);
1180 sys_setlogin(struct setlogin_args *uap)
1182 struct thread *td = curthread;
1185 char buf[MAXLOGNAME];
1188 cred = td->td_ucred;
1191 if ((error = priv_check_cred(cred, PRIV_PROC_SETLOGIN, 0)))
1193 bzero(buf, sizeof(buf));
1194 error = copyinstr(uap->namebuf, buf, sizeof(buf), NULL);
1195 if (error == ENAMETOOLONG)
1198 lwkt_gettoken_shared(&p->p_token);
1199 memcpy(p->p_pgrp->pg_session->s_login, buf, sizeof(buf));
1200 lwkt_reltoken(&p->p_token);
1208 struct proc *p = curproc;
1210 KKASSERT(p != NULL);
1211 lwkt_gettoken(&p->p_token);
1212 p->p_flags |= P_SUGID;
1213 if (!(p->p_pfsflags & PF_ISUGID))
1215 lwkt_reltoken(&p->p_token);
1219 * Helper function to change the effective uid of a process
1222 change_euid(uid_t euid)
1224 struct proc *p = curproc;
1227 KKASSERT(p != NULL);
1228 lf_count_adjust(p, 0);
1229 cr = cratom_proc(p);
1231 uireplace(&cr->cr_uidinfo, uifind(euid));
1232 lf_count_adjust(p, 1);
1237 * Helper function to change the real uid of a process
1239 * The per-uid process count for this process is transfered from
1240 * the old uid to the new uid.
1243 change_ruid(uid_t ruid)
1245 struct proc *p = curproc;
1248 KKASSERT(p != NULL);
1250 cr = cratom_proc(p);
1251 chgproccnt(cr->cr_ruidinfo, -1, 0);
1253 uireplace(&cr->cr_ruidinfo, uifind(ruid));
1254 chgproccnt(cr->cr_ruidinfo, 1, 0);