2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
4 * Copyright (c) 1993, David Greenman
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
32 #include "opt_capsicum.h"
33 #include "opt_hwpmc_hooks.h"
34 #include "opt_ktrace.h"
37 #include <sys/param.h>
38 #include <sys/systm.h>
40 #include <sys/capsicum.h>
41 #include <sys/eventhandler.h>
43 #include <sys/fcntl.h>
44 #include <sys/filedesc.h>
45 #include <sys/imgact.h>
46 #include <sys/imgact_elf.h>
47 #include <sys/kernel.h>
49 #include <sys/malloc.h>
51 #include <sys/mount.h>
52 #include <sys/mutex.h>
53 #include <sys/namei.h>
54 #include <sys/pioctl.h>
57 #include <sys/ptrace.h>
58 #include <sys/resourcevar.h>
59 #include <sys/rwlock.h>
60 #include <sys/sched.h>
62 #include <sys/sf_buf.h>
64 #include <sys/signalvar.h>
67 #include <sys/syscallsubr.h>
68 #include <sys/sysctl.h>
69 #include <sys/sysent.h>
70 #include <sys/sysproto.h>
71 #include <sys/vnode.h>
74 #include <sys/ktrace.h>
78 #include <vm/vm_param.h>
80 #include <vm/vm_page.h>
81 #include <vm/vm_map.h>
82 #include <vm/vm_kern.h>
83 #include <vm/vm_extern.h>
84 #include <vm/vm_object.h>
85 #include <vm/vm_pager.h>
88 #include <sys/pmckern.h>
91 #include <machine/reg.h>
93 #include <security/audit/audit.h>
94 #include <security/mac/mac_framework.h>
97 #include <sys/dtrace_bsd.h>
98 dtrace_execexit_func_t dtrace_fasttrap_exec;
101 SDT_PROVIDER_DECLARE(proc);
102 SDT_PROBE_DEFINE1(proc, , , exec, "char *");
103 SDT_PROBE_DEFINE1(proc, , , exec__failure, "int");
104 SDT_PROBE_DEFINE1(proc, , , exec__success, "char *");
106 MALLOC_DEFINE(M_PARGS, "proc-args", "Process arguments");
108 int coredump_pack_fileinfo = 1;
109 SYSCTL_INT(_kern, OID_AUTO, coredump_pack_fileinfo, CTLFLAG_RWTUN,
110 &coredump_pack_fileinfo, 0,
111 "Enable file path packing in 'procstat -f' coredump notes");
113 int coredump_pack_vmmapinfo = 1;
114 SYSCTL_INT(_kern, OID_AUTO, coredump_pack_vmmapinfo, CTLFLAG_RWTUN,
115 &coredump_pack_vmmapinfo, 0,
116 "Enable file path packing in 'procstat -v' coredump notes");
118 static int sysctl_kern_ps_strings(SYSCTL_HANDLER_ARGS);
119 static int sysctl_kern_usrstack(SYSCTL_HANDLER_ARGS);
120 static int sysctl_kern_stackprot(SYSCTL_HANDLER_ARGS);
121 static int do_execve(struct thread *td, struct image_args *args,
124 /* XXX This should be vm_size_t. */
125 SYSCTL_PROC(_kern, KERN_PS_STRINGS, ps_strings, CTLTYPE_ULONG|CTLFLAG_RD|
126 CTLFLAG_CAPRD|CTLFLAG_MPSAFE, NULL, 0, sysctl_kern_ps_strings, "LU", "");
128 /* XXX This should be vm_size_t. */
129 SYSCTL_PROC(_kern, KERN_USRSTACK, usrstack, CTLTYPE_ULONG|CTLFLAG_RD|
130 CTLFLAG_CAPRD|CTLFLAG_MPSAFE, NULL, 0, sysctl_kern_usrstack, "LU", "");
132 SYSCTL_PROC(_kern, OID_AUTO, stackprot, CTLTYPE_INT|CTLFLAG_RD|CTLFLAG_MPSAFE,
133 NULL, 0, sysctl_kern_stackprot, "I", "");
135 u_long ps_arg_cache_limit = PAGE_SIZE / 16;
136 SYSCTL_ULONG(_kern, OID_AUTO, ps_arg_cache_limit, CTLFLAG_RW,
137 &ps_arg_cache_limit, 0, "");
139 static int disallow_high_osrel;
140 SYSCTL_INT(_kern, OID_AUTO, disallow_high_osrel, CTLFLAG_RW,
141 &disallow_high_osrel, 0,
142 "Disallow execution of binaries built for higher version of the world");
144 static int map_at_zero = 0;
145 SYSCTL_INT(_security_bsd, OID_AUTO, map_at_zero, CTLFLAG_RWTUN, &map_at_zero, 0,
146 "Permit processes to map an object at virtual address 0.");
149 sysctl_kern_ps_strings(SYSCTL_HANDLER_ARGS)
156 if (req->flags & SCTL_MASK32) {
158 val = (unsigned int)p->p_sysent->sv_psstrings;
159 error = SYSCTL_OUT(req, &val, sizeof(val));
162 error = SYSCTL_OUT(req, &p->p_sysent->sv_psstrings,
163 sizeof(p->p_sysent->sv_psstrings));
168 sysctl_kern_usrstack(SYSCTL_HANDLER_ARGS)
175 if (req->flags & SCTL_MASK32) {
177 val = (unsigned int)p->p_sysent->sv_usrstack;
178 error = SYSCTL_OUT(req, &val, sizeof(val));
181 error = SYSCTL_OUT(req, &p->p_sysent->sv_usrstack,
182 sizeof(p->p_sysent->sv_usrstack));
187 sysctl_kern_stackprot(SYSCTL_HANDLER_ARGS)
192 return (SYSCTL_OUT(req, &p->p_sysent->sv_stackprot,
193 sizeof(p->p_sysent->sv_stackprot)));
197 * Each of the items is a pointer to a `const struct execsw', hence the
198 * double pointer here.
200 static const struct execsw **execsw;
202 #ifndef _SYS_SYSPROTO_H_
211 sys_execve(struct thread *td, struct execve_args *uap)
213 struct image_args args;
214 struct vmspace *oldvmspace;
217 error = pre_execve(td, &oldvmspace);
220 error = exec_copyin_args(&args, uap->fname, UIO_USERSPACE,
221 uap->argv, uap->envv);
223 error = kern_execve(td, &args, NULL);
224 post_execve(td, error, oldvmspace);
228 #ifndef _SYS_SYSPROTO_H_
229 struct fexecve_args {
236 sys_fexecve(struct thread *td, struct fexecve_args *uap)
238 struct image_args args;
239 struct vmspace *oldvmspace;
242 error = pre_execve(td, &oldvmspace);
245 error = exec_copyin_args(&args, NULL, UIO_SYSSPACE,
246 uap->argv, uap->envv);
249 error = kern_execve(td, &args, NULL);
251 post_execve(td, error, oldvmspace);
255 #ifndef _SYS_SYSPROTO_H_
256 struct __mac_execve_args {
265 sys___mac_execve(struct thread *td, struct __mac_execve_args *uap)
268 struct image_args args;
269 struct vmspace *oldvmspace;
272 error = pre_execve(td, &oldvmspace);
275 error = exec_copyin_args(&args, uap->fname, UIO_USERSPACE,
276 uap->argv, uap->envv);
278 error = kern_execve(td, &args, uap->mac_p);
279 post_execve(td, error, oldvmspace);
287 pre_execve(struct thread *td, struct vmspace **oldvmspace)
292 KASSERT(td == curthread, ("non-current thread %p", td));
295 if ((p->p_flag & P_HADTHREADS) != 0) {
297 if (thread_single(p, SINGLE_BOUNDARY) != 0)
301 KASSERT(error != 0 || (td->td_pflags & TDP_EXECVMSPC) == 0,
303 *oldvmspace = p->p_vmspace;
308 post_execve(struct thread *td, int error, struct vmspace *oldvmspace)
312 KASSERT(td == curthread, ("non-current thread %p", td));
314 if ((p->p_flag & P_HADTHREADS) != 0) {
317 * If success, we upgrade to SINGLE_EXIT state to
318 * force other threads to suicide.
320 if (error == EJUSTRETURN)
321 thread_single(p, SINGLE_EXIT);
323 thread_single_end(p, SINGLE_BOUNDARY);
326 if ((td->td_pflags & TDP_EXECVMSPC) != 0) {
327 KASSERT(p->p_vmspace != oldvmspace,
328 ("oldvmspace still used"));
329 vmspace_free(oldvmspace);
330 td->td_pflags &= ~TDP_EXECVMSPC;
335 * XXX: kern_execve has the astonishing property of not always returning to
336 * the caller. If sufficiently bad things happen during the call to
337 * do_execve(), it can end up calling exit1(); as a result, callers must
338 * avoid doing anything which they might need to undo (e.g., allocating
342 kern_execve(struct thread *td, struct image_args *args, struct mac *mac_p)
345 AUDIT_ARG_ARGV(args->begin_argv, args->argc,
346 exec_args_get_begin_envv(args) - args->begin_argv);
347 AUDIT_ARG_ENVV(exec_args_get_begin_envv(args), args->envc,
348 args->endp - exec_args_get_begin_envv(args));
349 return (do_execve(td, args, mac_p));
353 * In-kernel implementation of execve(). All arguments are assumed to be
354 * userspace pointers from the passed thread.
357 do_execve(struct thread *td, struct image_args *args, struct mac *mac_p)
359 struct proc *p = td->td_proc;
361 struct ucred *oldcred;
362 struct uidinfo *euip = NULL;
363 register_t *stack_base;
364 struct image_params image_params, *imgp;
366 int (*img_first)(struct image_params *);
367 struct pargs *oldargs = NULL, *newargs = NULL;
368 struct sigacts *oldsigacts = NULL, *newsigacts = NULL;
370 struct vnode *tracevp = NULL;
371 struct ucred *tracecred = NULL;
373 struct vnode *oldtextvp = NULL, *newtextvp;
374 int credential_changing;
376 struct label *interpvplabel = NULL;
380 struct pmckern_procexec pe;
382 int error, i, orig_osrel;
384 static const char fexecv_proc_title[] = "(fexecv)";
386 imgp = &image_params;
389 * Lock the process and set the P_INEXEC flag to indicate that
390 * it should be left alone until we're done here. This is
391 * necessary to avoid race conditions - e.g. in ptrace() -
392 * that might allow a local user to illicitly obtain elevated
396 KASSERT((p->p_flag & P_INEXEC) == 0,
397 ("%s(): process already has P_INEXEC flag", __func__));
398 p->p_flag |= P_INEXEC;
402 * Initialize part of the common data
404 bzero(imgp, sizeof(*imgp));
408 oldcred = p->p_ucred;
409 orig_osrel = p->p_osrel;
410 orig_fctl0 = p->p_fctl0;
413 error = mac_execve_enter(imgp, mac_p);
419 * Translate the file name. namei() returns a vnode pointer
420 * in ni_vp among other things.
422 * XXXAUDIT: It would be desirable to also audit the name of the
423 * interpreter if this is an interpreted binary.
425 if (args->fname != NULL) {
426 NDINIT(&nd, LOOKUP, ISOPEN | LOCKLEAF | LOCKSHARED | FOLLOW |
427 SAVENAME | AUDITVNODE1, UIO_SYSSPACE, args->fname, td);
430 SDT_PROBE1(proc, , , exec, args->fname);
433 if (args->fname != NULL) {
434 #ifdef CAPABILITY_MODE
436 * While capability mode can't reach this point via direct
437 * path arguments to execve(), we also don't allow
438 * interpreters to be used in capability mode (for now).
439 * Catch indirect lookups and return a permissions error.
441 if (IN_CAPABILITY_MODE(td)) {
450 newtextvp = nd.ni_vp;
451 imgp->vp = newtextvp;
453 AUDIT_ARG_FD(args->fd);
455 * Descriptors opened only with O_EXEC or O_RDONLY are allowed.
457 error = fgetvp_exec(td, args->fd, &cap_fexecve_rights, &newtextvp);
460 vn_lock(newtextvp, LK_SHARED | LK_RETRY);
461 AUDIT_ARG_VNODE1(newtextvp);
462 imgp->vp = newtextvp;
466 * Check file permissions. Also 'opens' file and sets its vnode to
469 error = exec_check_permissions(imgp);
471 goto exec_fail_dealloc;
473 imgp->object = imgp->vp->v_object;
474 if (imgp->object != NULL)
475 vm_object_reference(imgp->object);
477 error = exec_map_first_page(imgp);
479 goto exec_fail_dealloc;
481 imgp->proc->p_osrel = 0;
482 imgp->proc->p_fctl0 = 0;
485 * Implement image setuid/setgid.
487 * Determine new credentials before attempting image activators
488 * so that it can be used by process_exec handlers to determine
489 * credential/setid changes.
491 * Don't honor setuid/setgid if the filesystem prohibits it or if
492 * the process is being traced.
494 * We disable setuid/setgid/etc in capability mode on the basis
495 * that most setugid applications are not written with that
496 * environment in mind, and will therefore almost certainly operate
497 * incorrectly. In principle there's no reason that setugid
498 * applications might not be useful in capability mode, so we may want
499 * to reconsider this conservative design choice in the future.
501 * XXXMAC: For the time being, use NOSUID to also prohibit
502 * transitions on the file system.
504 credential_changing = 0;
505 credential_changing |= (attr.va_mode & S_ISUID) &&
506 oldcred->cr_uid != attr.va_uid;
507 credential_changing |= (attr.va_mode & S_ISGID) &&
508 oldcred->cr_gid != attr.va_gid;
510 will_transition = mac_vnode_execve_will_transition(oldcred, imgp->vp,
511 interpvplabel, imgp);
512 credential_changing |= will_transition;
515 /* Don't inherit PROC_PDEATHSIG_CTL value if setuid/setgid. */
516 if (credential_changing)
517 imgp->proc->p_pdeathsig = 0;
519 if (credential_changing &&
520 #ifdef CAPABILITY_MODE
521 ((oldcred->cr_flags & CRED_FLAG_CAPMODE) == 0) &&
523 (imgp->vp->v_mount->mnt_flag & MNT_NOSUID) == 0 &&
524 (p->p_flag & P_TRACED) == 0) {
525 imgp->credential_setid = true;
526 VOP_UNLOCK(imgp->vp, 0);
527 imgp->newcred = crdup(oldcred);
528 if (attr.va_mode & S_ISUID) {
529 euip = uifind(attr.va_uid);
530 change_euid(imgp->newcred, euip);
532 vn_lock(imgp->vp, LK_SHARED | LK_RETRY);
533 if (attr.va_mode & S_ISGID)
534 change_egid(imgp->newcred, attr.va_gid);
536 * Implement correct POSIX saved-id behavior.
538 * XXXMAC: Note that the current logic will save the
539 * uid and gid if a MAC domain transition occurs, even
540 * though maybe it shouldn't.
542 change_svuid(imgp->newcred, imgp->newcred->cr_uid);
543 change_svgid(imgp->newcred, imgp->newcred->cr_gid);
546 * Implement correct POSIX saved-id behavior.
548 * XXX: It's not clear that the existing behavior is
549 * POSIX-compliant. A number of sources indicate that the
550 * saved uid/gid should only be updated if the new ruid is
551 * not equal to the old ruid, or the new euid is not equal
552 * to the old euid and the new euid is not equal to the old
553 * ruid. The FreeBSD code always updates the saved uid/gid.
554 * Also, this code uses the new (replaced) euid and egid as
555 * the source, which may or may not be the right ones to use.
557 if (oldcred->cr_svuid != oldcred->cr_uid ||
558 oldcred->cr_svgid != oldcred->cr_gid) {
559 VOP_UNLOCK(imgp->vp, 0);
560 imgp->newcred = crdup(oldcred);
561 vn_lock(imgp->vp, LK_SHARED | LK_RETRY);
562 change_svuid(imgp->newcred, imgp->newcred->cr_uid);
563 change_svgid(imgp->newcred, imgp->newcred->cr_gid);
566 /* The new credentials are installed into the process later. */
569 * Do the best to calculate the full path to the image file.
571 if (args->fname != NULL && args->fname[0] == '/')
572 imgp->execpath = args->fname;
574 VOP_UNLOCK(imgp->vp, 0);
575 if (vn_fullpath(td, imgp->vp, &imgp->execpath,
576 &imgp->freepath) != 0)
577 imgp->execpath = args->fname;
578 vn_lock(imgp->vp, LK_SHARED | LK_RETRY);
582 * If the current process has a special image activator it
583 * wants to try first, call it. For example, emulating shell
584 * scripts differently.
587 if ((img_first = imgp->proc->p_sysent->sv_imgact_try) != NULL)
588 error = img_first(imgp);
591 * Loop through the list of image activators, calling each one.
592 * An activator returns -1 if there is no match, 0 on success,
593 * and an error otherwise.
595 for (i = 0; error == -1 && execsw[i]; ++i) {
596 if (execsw[i]->ex_imgact == NULL ||
597 execsw[i]->ex_imgact == img_first) {
600 error = (*execsw[i]->ex_imgact)(imgp);
606 goto exec_fail_dealloc;
610 * Special interpreter operation, cleanup and loop up to try to
611 * activate the interpreter.
613 if (imgp->interpreted) {
614 exec_unmap_first_page(imgp);
616 * The text reference needs to be removed for scripts.
617 * There is a short period before we determine that
618 * something is a script where text reference is active.
619 * The vnode lock is held over this entire period
620 * so nothing should illegitimately be blocked.
622 MPASS(imgp->textset);
623 VOP_UNSET_TEXT_CHECKED(newtextvp);
624 imgp->textset = false;
625 /* free name buffer and old vnode */
626 if (args->fname != NULL)
627 NDFREE(&nd, NDF_ONLY_PNBUF);
629 mac_execve_interpreter_enter(newtextvp, &interpvplabel);
632 VOP_CLOSE(newtextvp, FREAD, td->td_ucred, td);
636 vm_object_deallocate(imgp->object);
638 imgp->credential_setid = false;
639 if (imgp->newcred != NULL) {
640 crfree(imgp->newcred);
641 imgp->newcred = NULL;
643 imgp->execpath = NULL;
644 free(imgp->freepath, M_TEMP);
645 imgp->freepath = NULL;
646 /* set new name to that of the interpreter */
647 NDINIT(&nd, LOOKUP, ISOPEN | LOCKLEAF | FOLLOW | SAVENAME,
648 UIO_SYSSPACE, imgp->interpreter_name, td);
649 args->fname = imgp->interpreter_name;
654 * NB: We unlock the vnode here because it is believed that none
655 * of the sv_copyout_strings/sv_fixup operations require the vnode.
657 VOP_UNLOCK(imgp->vp, 0);
659 if (disallow_high_osrel &&
660 P_OSREL_MAJOR(p->p_osrel) > P_OSREL_MAJOR(__FreeBSD_version)) {
662 uprintf("Osrel %d for image %s too high\n", p->p_osrel,
663 imgp->execpath != NULL ? imgp->execpath : "<unresolved>");
664 vn_lock(imgp->vp, LK_SHARED | LK_RETRY);
665 goto exec_fail_dealloc;
668 /* ABI enforces the use of Capsicum. Switch into capabilities mode. */
669 if (SV_PROC_FLAG(p, SV_CAPSICUM))
670 sys_cap_enter(td, NULL);
673 * Copy out strings (args and env) and initialize stack base.
675 error = (*p->p_sysent->sv_copyout_strings)(imgp, &stack_base);
677 vn_lock(imgp->vp, LK_SHARED | LK_RETRY);
678 goto exec_fail_dealloc;
684 error = (*p->p_sysent->sv_fixup)(&stack_base, imgp);
686 vn_lock(imgp->vp, LK_SHARED | LK_RETRY);
687 goto exec_fail_dealloc;
690 if (args->fdp != NULL) {
691 /* Install a brand new file descriptor table. */
692 fdinstall_remapped(td, args->fdp);
696 * Keep on using the existing file descriptor table. For
697 * security and other reasons, the file descriptor table
698 * cannot be shared after an exec.
701 /* close files on exec */
706 * Malloc things before we need locks.
708 i = exec_args_get_begin_envv(imgp->args) - imgp->args->begin_argv;
709 /* Cache arguments if they fit inside our allowance */
710 if (ps_arg_cache_limit >= i + sizeof(struct pargs)) {
711 newargs = pargs_alloc(i);
712 bcopy(imgp->args->begin_argv, newargs->ar_args, i);
716 * For security and other reasons, signal handlers cannot
717 * be shared after an exec. The new process gets a copy of the old
718 * handlers. In execsigs(), the new process will have its signals
721 if (sigacts_shared(p->p_sigacts)) {
722 oldsigacts = p->p_sigacts;
723 newsigacts = sigacts_alloc();
724 sigacts_copy(newsigacts, oldsigacts);
727 vn_lock(imgp->vp, LK_SHARED | LK_RETRY);
731 p->p_sigacts = newsigacts;
735 /* reset caught signals */
738 /* name this process - nameiexec(p, ndp) */
739 bzero(p->p_comm, sizeof(p->p_comm));
741 bcopy(nd.ni_cnd.cn_nameptr, p->p_comm,
742 min(nd.ni_cnd.cn_namelen, MAXCOMLEN));
743 else if (vn_commname(newtextvp, p->p_comm, sizeof(p->p_comm)) != 0)
744 bcopy(fexecv_proc_title, p->p_comm, sizeof(fexecv_proc_title));
745 bcopy(p->p_comm, td->td_name, sizeof(td->td_name));
747 sched_clear_tdname(td);
751 * mark as execed, wakeup the process that vforked (if any) and tell
752 * it that it now has its own resources back
755 if ((p->p_flag2 & P2_NOTRACE_EXEC) == 0)
756 p->p_flag2 &= ~P2_NOTRACE;
757 if ((p->p_flag2 & P2_STKGAP_DISABLE_EXEC) == 0)
758 p->p_flag2 &= ~P2_STKGAP_DISABLE;
759 if (p->p_flag & P_PPWAIT) {
760 p->p_flag &= ~(P_PPWAIT | P_PPTRACE);
761 cv_broadcast(&p->p_pwait);
762 /* STOPs are no longer ignored, arrange for AST */
767 * Implement image setuid/setgid installation.
769 if (imgp->credential_setid) {
771 * Turn off syscall tracing for set-id programs, except for
772 * root. Record any set-id flags first to make sure that
773 * we do not regain any tracing during a possible block.
778 if (p->p_tracecred != NULL &&
779 priv_check_cred(p->p_tracecred, PRIV_DEBUG_DIFFCRED))
780 ktrprocexec(p, &tracecred, &tracevp);
783 * Close any file descriptors 0..2 that reference procfs,
784 * then make sure file descriptors 0..2 are in use.
786 * Both fdsetugidsafety() and fdcheckstd() may call functions
787 * taking sleepable locks, so temporarily drop our locks.
790 VOP_UNLOCK(imgp->vp, 0);
792 error = fdcheckstd(td);
793 vn_lock(imgp->vp, LK_SHARED | LK_RETRY);
795 goto exec_fail_dealloc;
798 if (will_transition) {
799 mac_vnode_execve_transition(oldcred, imgp->newcred,
800 imgp->vp, interpvplabel, imgp);
804 if (oldcred->cr_uid == oldcred->cr_ruid &&
805 oldcred->cr_gid == oldcred->cr_rgid)
806 p->p_flag &= ~P_SUGID;
809 * Set the new credentials.
811 if (imgp->newcred != NULL) {
812 proc_set_cred(p, imgp->newcred);
818 * Store the vp for use in procfs. This vnode was referenced by namei
821 oldtextvp = p->p_textvp;
822 p->p_textvp = newtextvp;
826 * Tell the DTrace fasttrap provider about the exec if it
827 * has declared an interest.
829 if (dtrace_fasttrap_exec)
830 dtrace_fasttrap_exec(p);
834 * Notify others that we exec'd, and clear the P_INEXEC flag
835 * as we're now a bona fide freshly-execed process.
837 KNOTE_LOCKED(p->p_klist, NOTE_EXEC);
838 p->p_flag &= ~P_INEXEC;
840 /* clear "fork but no exec" flag, as we _are_ execing */
841 p->p_acflag &= ~AFORK;
844 * Free any previous argument cache and replace it with
845 * the new argument cache, if any.
855 * Check if system-wide sampling is in effect or if the
856 * current process is using PMCs. If so, do exec() time
857 * processing. This processing needs to happen AFTER the
858 * P_INEXEC flag is cleared.
860 if (PMC_SYSTEM_SAMPLING_ACTIVE() || PMC_PROC_IS_USING_PMCS(p)) {
861 VOP_UNLOCK(imgp->vp, 0);
862 pe.pm_credentialschanged = credential_changing;
863 pe.pm_entryaddr = imgp->entry_addr;
865 PMC_CALL_HOOK_X(td, PMC_FN_PROCESS_EXEC, (void *) &pe);
866 vn_lock(imgp->vp, LK_SHARED | LK_RETRY);
870 /* Set values passed into the program in registers. */
871 (*p->p_sysent->sv_setregs)(td, imgp, (u_long)(uintptr_t)stack_base);
873 vfs_mark_atime(imgp->vp, td->td_ucred);
875 SDT_PROBE1(proc, , , exec__success, args->fname);
879 p->p_osrel = orig_osrel;
880 p->p_fctl0 = orig_fctl0;
883 if (imgp->firstpage != NULL)
884 exec_unmap_first_page(imgp);
886 if (imgp->vp != NULL) {
888 NDFREE(&nd, NDF_ONLY_PNBUF);
890 VOP_CLOSE(imgp->vp, FREAD, td->td_ucred, td);
892 VOP_UNSET_TEXT_CHECKED(imgp->vp);
896 VOP_UNLOCK(imgp->vp, 0);
899 if (imgp->object != NULL)
900 vm_object_deallocate(imgp->object);
902 free(imgp->freepath, M_TEMP);
905 if (p->p_ptevents & PTRACE_EXEC) {
907 if (p->p_ptevents & PTRACE_EXEC)
908 td->td_dbgflags |= TDB_EXEC;
913 * Stop the process here if its stop event mask has
914 * the S_EXEC bit set.
916 STOPEVENT(p, S_EXEC, 0);
919 /* we're done here, clear P_INEXEC */
921 p->p_flag &= ~P_INEXEC;
924 SDT_PROBE1(proc, , , exec__failure, error);
927 if (imgp->newcred != NULL && oldcred != NULL)
928 crfree(imgp->newcred);
931 mac_execve_exit(imgp);
932 mac_execve_interpreter_exit(interpvplabel);
934 exec_free_args(args);
937 * Handle deferred decrement of ref counts.
939 if (oldtextvp != NULL)
944 if (tracecred != NULL)
949 if (oldsigacts != NULL)
950 sigacts_free(oldsigacts);
954 if (error && imgp->vmspace_destroyed) {
955 /* sorry, no more process anymore. exit gracefully */
956 exit1(td, 0, SIGABRT);
966 * We don't want cpu_set_syscall_retval() to overwrite any of
967 * the register values put in place by exec_setregs().
968 * Implementations of cpu_set_syscall_retval() will leave
969 * registers unmodified when returning EJUSTRETURN.
971 return (error == 0 ? EJUSTRETURN : error);
975 exec_map_first_page(struct image_params *imgp)
977 int rv, i, after, initial_pagein;
978 vm_page_t ma[VM_INITIAL_PAGEIN];
981 if (imgp->firstpage != NULL)
982 exec_unmap_first_page(imgp);
984 object = imgp->vp->v_object;
987 VM_OBJECT_WLOCK(object);
988 #if VM_NRESERVLEVEL > 0
989 vm_object_color(object, 0);
992 ma[0] = vm_page_grab(object, 0, VM_ALLOC_NORMAL | VM_ALLOC_NOBUSY |
994 if (!vm_page_all_valid(ma[0])) {
995 if (vm_page_busy_acquire(ma[0], VM_ALLOC_WAITFAIL) == 0) {
996 vm_page_unwire_noq(ma[0]);
999 if (vm_page_all_valid(ma[0])) {
1000 vm_page_xunbusy(ma[0]);
1003 if (!vm_pager_has_page(object, 0, NULL, &after)) {
1004 if (vm_page_unwire_noq(ma[0]))
1005 vm_page_free(ma[0]);
1007 vm_page_xunbusy(ma[0]);
1008 VM_OBJECT_WUNLOCK(object);
1011 initial_pagein = min(after, VM_INITIAL_PAGEIN);
1012 KASSERT(initial_pagein <= object->size,
1013 ("%s: initial_pagein %d object->size %ju",
1014 __func__, initial_pagein, (uintmax_t )object->size));
1015 for (i = 1; i < initial_pagein; i++) {
1016 if ((ma[i] = vm_page_next(ma[i - 1])) != NULL) {
1019 if (!vm_page_tryxbusy(ma[i]))
1022 ma[i] = vm_page_alloc(object, i,
1029 rv = vm_pager_get_pages(object, ma, initial_pagein, NULL, NULL);
1030 if (rv != VM_PAGER_OK) {
1031 if (vm_page_unwire_noq(ma[0]))
1032 vm_page_free(ma[0]);
1034 vm_page_xunbusy(ma[0]);
1035 for (i = 1; i < initial_pagein; i++) {
1036 if (!vm_page_wired(ma[i]))
1037 vm_page_free(ma[i]);
1039 vm_page_xunbusy(ma[i]);
1041 VM_OBJECT_WUNLOCK(object);
1044 vm_page_xunbusy(ma[0]);
1045 for (i = 1; i < initial_pagein; i++)
1046 vm_page_readahead_finish(ma[i]);
1050 VM_OBJECT_WUNLOCK(object);
1052 imgp->firstpage = sf_buf_alloc(ma[0], 0);
1053 imgp->image_header = (char *)sf_buf_kva(imgp->firstpage);
1059 exec_unmap_first_page(struct image_params *imgp)
1063 if (imgp->firstpage != NULL) {
1064 m = sf_buf_page(imgp->firstpage);
1065 sf_buf_free(imgp->firstpage);
1066 imgp->firstpage = NULL;
1067 vm_page_unwire(m, PQ_ACTIVE);
1072 * Destroy old address space, and allocate a new stack.
1073 * The new stack is only sgrowsiz large because it is grown
1074 * automatically on a page fault.
1077 exec_new_vmspace(struct image_params *imgp, struct sysentvec *sv)
1080 struct proc *p = imgp->proc;
1081 struct vmspace *vmspace = p->p_vmspace;
1083 struct rlimit rlim_stack;
1084 vm_offset_t sv_minuser, stack_addr;
1088 imgp->vmspace_destroyed = 1;
1091 /* May be called with Giant held */
1092 EVENTHANDLER_DIRECT_INVOKE(process_exec, p, imgp);
1095 * Blow away entire process VM, if address space not shared,
1096 * otherwise, create a new VM space so that other threads are
1099 map = &vmspace->vm_map;
1101 sv_minuser = sv->sv_minuser;
1103 sv_minuser = MAX(sv->sv_minuser, PAGE_SIZE);
1104 if (vmspace->vm_refcnt == 1 && vm_map_min(map) == sv_minuser &&
1105 vm_map_max(map) == sv->sv_maxuser &&
1106 cpu_exec_vmspace_reuse(p, map)) {
1108 pmap_remove_pages(vmspace_pmap(vmspace));
1109 vm_map_remove(map, vm_map_min(map), vm_map_max(map));
1111 * An exec terminates mlockall(MCL_FUTURE), ASLR state
1112 * must be re-evaluated.
1115 vm_map_modflags(map, 0, MAP_WIREFUTURE | MAP_ASLR |
1119 error = vmspace_exec(p, sv_minuser, sv->sv_maxuser);
1122 vmspace = p->p_vmspace;
1123 map = &vmspace->vm_map;
1125 map->flags |= imgp->map_flags;
1127 /* Map a shared page */
1128 obj = sv->sv_shared_page_obj;
1130 vm_object_reference(obj);
1131 error = vm_map_fixed(map, obj, 0,
1132 sv->sv_shared_page_base, sv->sv_shared_page_len,
1133 VM_PROT_READ | VM_PROT_EXECUTE,
1134 VM_PROT_READ | VM_PROT_EXECUTE,
1135 MAP_INHERIT_SHARE | MAP_ACC_NO_CHARGE);
1136 if (error != KERN_SUCCESS) {
1137 vm_object_deallocate(obj);
1138 return (vm_mmap_to_errno(error));
1142 /* Allocate a new stack */
1143 if (imgp->stack_sz != 0) {
1144 ssiz = trunc_page(imgp->stack_sz);
1146 lim_rlimit_proc(p, RLIMIT_STACK, &rlim_stack);
1148 if (ssiz > rlim_stack.rlim_max)
1149 ssiz = rlim_stack.rlim_max;
1150 if (ssiz > rlim_stack.rlim_cur) {
1151 rlim_stack.rlim_cur = ssiz;
1152 kern_setrlimit(curthread, RLIMIT_STACK, &rlim_stack);
1154 } else if (sv->sv_maxssiz != NULL) {
1155 ssiz = *sv->sv_maxssiz;
1159 imgp->eff_stack_sz = lim_cur(curthread, RLIMIT_STACK);
1160 if (ssiz < imgp->eff_stack_sz)
1161 imgp->eff_stack_sz = ssiz;
1162 stack_addr = sv->sv_usrstack - ssiz;
1163 error = vm_map_stack(map, stack_addr, (vm_size_t)ssiz,
1164 obj != NULL && imgp->stack_prot != 0 ? imgp->stack_prot :
1165 sv->sv_stackprot, VM_PROT_ALL, MAP_STACK_GROWS_DOWN);
1166 if (error != KERN_SUCCESS)
1167 return (vm_mmap_to_errno(error));
1170 * vm_ssize and vm_maxsaddr are somewhat antiquated concepts, but they
1171 * are still used to enforce the stack rlimit on the process stack.
1173 vmspace->vm_ssize = sgrowsiz >> PAGE_SHIFT;
1174 vmspace->vm_maxsaddr = (char *)stack_addr;
1180 * Copy out argument and environment strings from the old process address
1181 * space into the temporary string buffer.
1184 exec_copyin_args(struct image_args *args, const char *fname,
1185 enum uio_seg segflg, char **argv, char **envv)
1190 bzero(args, sizeof(*args));
1195 * Allocate demand-paged memory for the file name, argument, and
1196 * environment strings.
1198 error = exec_alloc_args(args);
1203 * Copy the file name.
1205 error = exec_args_add_fname(args, fname, segflg);
1210 * extract arguments first
1213 error = fueword(argv++, &arg);
1220 error = exec_args_add_arg(args, (char *)(uintptr_t)arg,
1227 * extract environment strings
1231 error = fueword(envv++, &env);
1238 error = exec_args_add_env(args,
1239 (char *)(uintptr_t)env, UIO_USERSPACE);
1248 exec_free_args(args);
1253 exec_copyin_data_fds(struct thread *td, struct image_args *args,
1254 const void *data, size_t datalen, const int *fds, size_t fdslen)
1256 struct filedesc *ofdp;
1261 memset(args, '\0', sizeof(*args));
1262 ofdp = td->td_proc->p_fd;
1263 if (datalen >= ARG_MAX || fdslen > ofdp->fd_lastfile + 1)
1265 error = exec_alloc_args(args);
1269 args->begin_argv = args->buf;
1270 args->stringspace = ARG_MAX;
1274 * Argument buffer has been provided. Copy it into the
1275 * kernel as a single string and add a terminating null
1278 error = copyin(data, args->begin_argv, datalen);
1281 args->begin_argv[datalen] = '\0';
1282 args->endp = args->begin_argv + datalen + 1;
1283 args->stringspace -= datalen + 1;
1286 * Traditional argument counting. Count the number of
1289 for (p = args->begin_argv; p < args->endp; ++p)
1293 /* No argument buffer provided. */
1294 args->endp = args->begin_argv;
1297 /* Create new file descriptor table. */
1298 kfds = malloc(fdslen * sizeof(int), M_TEMP, M_WAITOK);
1299 error = copyin(fds, kfds, fdslen * sizeof(int));
1304 error = fdcopy_remapped(ofdp, kfds, fdslen, &args->fdp);
1311 exec_free_args(args);
1315 struct exec_args_kva {
1318 SLIST_ENTRY(exec_args_kva) next;
1321 DPCPU_DEFINE_STATIC(struct exec_args_kva *, exec_args_kva);
1323 static SLIST_HEAD(, exec_args_kva) exec_args_kva_freelist;
1324 static struct mtx exec_args_kva_mtx;
1325 static u_int exec_args_gen;
1328 exec_prealloc_args_kva(void *arg __unused)
1330 struct exec_args_kva *argkva;
1333 SLIST_INIT(&exec_args_kva_freelist);
1334 mtx_init(&exec_args_kva_mtx, "exec args kva", NULL, MTX_DEF);
1335 for (i = 0; i < exec_map_entries; i++) {
1336 argkva = malloc(sizeof(*argkva), M_PARGS, M_WAITOK);
1337 argkva->addr = kmap_alloc_wait(exec_map, exec_map_entry_size);
1338 argkva->gen = exec_args_gen;
1339 SLIST_INSERT_HEAD(&exec_args_kva_freelist, argkva, next);
1342 SYSINIT(exec_args_kva, SI_SUB_EXEC, SI_ORDER_ANY, exec_prealloc_args_kva, NULL);
1345 exec_alloc_args_kva(void **cookie)
1347 struct exec_args_kva *argkva;
1349 argkva = (void *)atomic_readandclear_ptr(
1350 (uintptr_t *)DPCPU_PTR(exec_args_kva));
1351 if (argkva == NULL) {
1352 mtx_lock(&exec_args_kva_mtx);
1353 while ((argkva = SLIST_FIRST(&exec_args_kva_freelist)) == NULL)
1354 (void)mtx_sleep(&exec_args_kva_freelist,
1355 &exec_args_kva_mtx, 0, "execkva", 0);
1356 SLIST_REMOVE_HEAD(&exec_args_kva_freelist, next);
1357 mtx_unlock(&exec_args_kva_mtx);
1359 *(struct exec_args_kva **)cookie = argkva;
1360 return (argkva->addr);
1364 exec_release_args_kva(struct exec_args_kva *argkva, u_int gen)
1368 base = argkva->addr;
1369 if (argkva->gen != gen) {
1370 (void)vm_map_madvise(exec_map, base, base + exec_map_entry_size,
1374 if (!atomic_cmpset_ptr((uintptr_t *)DPCPU_PTR(exec_args_kva),
1375 (uintptr_t)NULL, (uintptr_t)argkva)) {
1376 mtx_lock(&exec_args_kva_mtx);
1377 SLIST_INSERT_HEAD(&exec_args_kva_freelist, argkva, next);
1378 wakeup_one(&exec_args_kva_freelist);
1379 mtx_unlock(&exec_args_kva_mtx);
1384 exec_free_args_kva(void *cookie)
1387 exec_release_args_kva(cookie, exec_args_gen);
1391 exec_args_kva_lowmem(void *arg __unused)
1393 SLIST_HEAD(, exec_args_kva) head;
1394 struct exec_args_kva *argkva;
1398 gen = atomic_fetchadd_int(&exec_args_gen, 1) + 1;
1401 * Force an madvise of each KVA range. Any currently allocated ranges
1402 * will have MADV_FREE applied once they are freed.
1405 mtx_lock(&exec_args_kva_mtx);
1406 SLIST_SWAP(&head, &exec_args_kva_freelist, exec_args_kva);
1407 mtx_unlock(&exec_args_kva_mtx);
1408 while ((argkva = SLIST_FIRST(&head)) != NULL) {
1409 SLIST_REMOVE_HEAD(&head, next);
1410 exec_release_args_kva(argkva, gen);
1414 argkva = (void *)atomic_readandclear_ptr(
1415 (uintptr_t *)DPCPU_ID_PTR(i, exec_args_kva));
1417 exec_release_args_kva(argkva, gen);
1420 EVENTHANDLER_DEFINE(vm_lowmem, exec_args_kva_lowmem, NULL,
1421 EVENTHANDLER_PRI_ANY);
1424 * Allocate temporary demand-paged, zero-filled memory for the file name,
1425 * argument, and environment strings.
1428 exec_alloc_args(struct image_args *args)
1431 args->buf = (char *)exec_alloc_args_kva(&args->bufkva);
1436 exec_free_args(struct image_args *args)
1439 if (args->buf != NULL) {
1440 exec_free_args_kva(args->bufkva);
1443 if (args->fname_buf != NULL) {
1444 free(args->fname_buf, M_TEMP);
1445 args->fname_buf = NULL;
1447 if (args->fdp != NULL)
1448 fdescfree_remapped(args->fdp);
1452 * A set to functions to fill struct image args.
1454 * NOTE: exec_args_add_fname() must be called (possibly with a NULL
1455 * fname) before the other functions. All exec_args_add_arg() calls must
1456 * be made before any exec_args_add_env() calls. exec_args_adjust_args()
1457 * may be called any time after exec_args_add_fname().
1459 * exec_args_add_fname() - install path to be executed
1460 * exec_args_add_arg() - append an argument string
1461 * exec_args_add_env() - append an env string
1462 * exec_args_adjust_args() - adjust location of the argument list to
1463 * allow new arguments to be prepended
1466 exec_args_add_fname(struct image_args *args, const char *fname,
1467 enum uio_seg segflg)
1472 KASSERT(args->fname == NULL, ("fname already appended"));
1473 KASSERT(args->endp == NULL, ("already appending to args"));
1475 if (fname != NULL) {
1476 args->fname = args->buf;
1477 error = segflg == UIO_SYSSPACE ?
1478 copystr(fname, args->fname, PATH_MAX, &length) :
1479 copyinstr(fname, args->fname, PATH_MAX, &length);
1481 return (error == ENAMETOOLONG ? E2BIG : error);
1485 /* Set up for _arg_*()/_env_*() */
1486 args->endp = args->buf + length;
1487 /* begin_argv must be set and kept updated */
1488 args->begin_argv = args->endp;
1489 KASSERT(exec_map_entry_size - length >= ARG_MAX,
1490 ("too little space remaining for arguments %zu < %zu",
1491 exec_map_entry_size - length, (size_t)ARG_MAX));
1492 args->stringspace = ARG_MAX;
1498 exec_args_add_str(struct image_args *args, const char *str,
1499 enum uio_seg segflg, int *countp)
1504 KASSERT(args->endp != NULL, ("endp not initialized"));
1505 KASSERT(args->begin_argv != NULL, ("begin_argp not initialized"));
1507 error = (segflg == UIO_SYSSPACE) ?
1508 copystr(str, args->endp, args->stringspace, &length) :
1509 copyinstr(str, args->endp, args->stringspace, &length);
1511 return (error == ENAMETOOLONG ? E2BIG : error);
1512 args->stringspace -= length;
1513 args->endp += length;
1520 exec_args_add_arg(struct image_args *args, const char *argp,
1521 enum uio_seg segflg)
1524 KASSERT(args->envc == 0, ("appending args after env"));
1526 return (exec_args_add_str(args, argp, segflg, &args->argc));
1530 exec_args_add_env(struct image_args *args, const char *envp,
1531 enum uio_seg segflg)
1534 if (args->envc == 0)
1535 args->begin_envv = args->endp;
1537 return (exec_args_add_str(args, envp, segflg, &args->envc));
1541 exec_args_adjust_args(struct image_args *args, size_t consume, ssize_t extend)
1545 KASSERT(args->endp != NULL, ("endp not initialized"));
1546 KASSERT(args->begin_argv != NULL, ("begin_argp not initialized"));
1548 offset = extend - consume;
1549 if (args->stringspace < offset)
1551 memmove(args->begin_argv + extend, args->begin_argv + consume,
1552 args->endp - args->begin_argv + consume);
1554 args->begin_envv += offset;
1555 args->endp += offset;
1556 args->stringspace -= offset;
1561 exec_args_get_begin_envv(struct image_args *args)
1564 KASSERT(args->endp != NULL, ("endp not initialized"));
1567 return (args->begin_envv);
1568 return (args->endp);
1572 * Copy strings out to the new process address space, constructing new arg
1573 * and env vector tables. Return a pointer to the base so that it can be used
1574 * as the initial stack pointer.
1577 exec_copyout_strings(struct image_params *imgp, register_t **stack_base)
1583 struct ps_strings *arginfo;
1585 size_t execpath_len;
1586 int error, szsigcode, szps;
1587 char canary[sizeof(long) * 8];
1589 szps = sizeof(pagesizes[0]) * MAXPAGESIZES;
1591 * Calculate string base and vector table pointers.
1592 * Also deal with signal trampoline code for this exec type.
1594 if (imgp->execpath != NULL && imgp->auxargs != NULL)
1595 execpath_len = strlen(imgp->execpath) + 1;
1600 arginfo = (struct ps_strings *)p->p_sysent->sv_psstrings;
1601 if (p->p_sysent->sv_sigcode_base == 0) {
1602 if (p->p_sysent->sv_szsigcode != NULL)
1603 szsigcode = *(p->p_sysent->sv_szsigcode);
1605 destp = (uintptr_t)arginfo;
1610 if (szsigcode != 0) {
1612 destp = rounddown2(destp, sizeof(void *));
1613 error = copyout(p->p_sysent->sv_sigcode, (void *)destp,
1620 * Copy the image path for the rtld.
1622 if (execpath_len != 0) {
1623 destp -= execpath_len;
1624 destp = rounddown2(destp, sizeof(void *));
1625 imgp->execpathp = destp;
1626 error = copyout(imgp->execpath, (void *)destp, execpath_len);
1632 * Prepare the canary for SSP.
1634 arc4rand(canary, sizeof(canary), 0);
1635 destp -= sizeof(canary);
1636 imgp->canary = destp;
1637 error = copyout(canary, (void *)destp, sizeof(canary));
1640 imgp->canarylen = sizeof(canary);
1643 * Prepare the pagesizes array.
1646 destp = rounddown2(destp, sizeof(void *));
1647 imgp->pagesizes = destp;
1648 error = copyout(pagesizes, (void *)destp, szps);
1651 imgp->pagesizeslen = szps;
1653 destp -= ARG_MAX - imgp->args->stringspace;
1654 destp = rounddown2(destp, sizeof(void *));
1656 vectp = (char **)destp;
1657 if (imgp->sysent->sv_stackgap != NULL)
1658 imgp->sysent->sv_stackgap(imgp, (u_long *)&vectp);
1660 if (imgp->auxargs) {
1661 error = imgp->sysent->sv_copyout_auxargs(imgp,
1668 * Allocate room for the argv[] and env vectors including the
1669 * terminating NULL pointers.
1671 vectp -= imgp->args->argc + 1 + imgp->args->envc + 1;
1674 * vectp also becomes our initial stack base
1676 *stack_base = (register_t *)vectp;
1678 stringp = imgp->args->begin_argv;
1679 argc = imgp->args->argc;
1680 envc = imgp->args->envc;
1683 * Copy out strings - arguments and environment.
1685 error = copyout(stringp, (void *)destp,
1686 ARG_MAX - imgp->args->stringspace);
1691 * Fill in "ps_strings" struct for ps, w, etc.
1693 if (suword(&arginfo->ps_argvstr, (long)(intptr_t)vectp) != 0 ||
1694 suword32(&arginfo->ps_nargvstr, argc) != 0)
1698 * Fill in argument portion of vector table.
1700 for (; argc > 0; --argc) {
1701 if (suword(vectp++, (long)(intptr_t)destp) != 0)
1703 while (*stringp++ != 0)
1708 /* a null vector table pointer separates the argp's from the envp's */
1709 if (suword(vectp++, 0) != 0)
1712 if (suword(&arginfo->ps_envstr, (long)(intptr_t)vectp) != 0 ||
1713 suword32(&arginfo->ps_nenvstr, envc) != 0)
1717 * Fill in environment portion of vector table.
1719 for (; envc > 0; --envc) {
1720 if (suword(vectp++, (long)(intptr_t)destp) != 0)
1722 while (*stringp++ != 0)
1727 /* end of vector table is a null pointer */
1728 if (suword(vectp, 0) != 0)
1735 * Check permissions of file to execute.
1736 * Called with imgp->vp locked.
1737 * Return 0 for success or error code on failure.
1740 exec_check_permissions(struct image_params *imgp)
1742 struct vnode *vp = imgp->vp;
1743 struct vattr *attr = imgp->attr;
1749 /* Get file attributes */
1750 error = VOP_GETATTR(vp, attr, td->td_ucred);
1755 error = mac_vnode_check_exec(td->td_ucred, imgp->vp, imgp);
1761 * 1) Check if file execution is disabled for the filesystem that
1762 * this file resides on.
1763 * 2) Ensure that at least one execute bit is on. Otherwise, a
1764 * privileged user will always succeed, and we don't want this
1765 * to happen unless the file really is executable.
1766 * 3) Ensure that the file is a regular file.
1768 if ((vp->v_mount->mnt_flag & MNT_NOEXEC) ||
1769 (attr->va_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) == 0 ||
1770 (attr->va_type != VREG))
1774 * Zero length files can't be exec'd
1776 if (attr->va_size == 0)
1780 * Check for execute permission to file based on current credentials.
1782 error = VOP_ACCESS(vp, VEXEC, td->td_ucred, td);
1787 * Check number of open-for-writes on the file and deny execution
1790 * Add a text reference now so no one can write to the
1791 * executable while we're activating it.
1793 * Remember if this was set before and unset it in case this is not
1794 * actually an executable image.
1796 error = VOP_SET_TEXT(vp);
1799 imgp->textset = true;
1802 * Call filesystem specific open routine (which does nothing in the
1805 error = VOP_OPEN(vp, FREAD, td->td_ucred, td, NULL);
1812 * Exec handler registration
1815 exec_register(const struct execsw *execsw_arg)
1817 const struct execsw **es, **xs, **newexecsw;
1818 u_int count = 2; /* New slot and trailing NULL */
1821 for (es = execsw; *es; es++)
1823 newexecsw = malloc(count * sizeof(*es), M_TEMP, M_WAITOK);
1826 for (es = execsw; *es; es++)
1831 free(execsw, M_TEMP);
1837 exec_unregister(const struct execsw *execsw_arg)
1839 const struct execsw **es, **xs, **newexecsw;
1843 panic("unregister with no handlers left?\n");
1845 for (es = execsw; *es; es++) {
1846 if (*es == execsw_arg)
1851 for (es = execsw; *es; es++)
1852 if (*es != execsw_arg)
1854 newexecsw = malloc(count * sizeof(*es), M_TEMP, M_WAITOK);
1856 for (es = execsw; *es; es++)
1857 if (*es != execsw_arg)
1861 free(execsw, M_TEMP);