2 * Copyright (c) 1993, David Greenman
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
30 #include "opt_ktrace.h"
33 #include <sys/param.h>
34 #include <sys/systm.h>
35 #include <sys/eventhandler.h>
37 #include <sys/mutex.h>
38 #include <sys/sysproto.h>
39 #include <sys/signalvar.h>
40 #include <sys/kernel.h>
42 #include <sys/mount.h>
43 #include <sys/filedesc.h>
44 #include <sys/fcntl.h>
47 #include <sys/imgact.h>
48 #include <sys/imgact_elf.h>
50 #include <sys/malloc.h>
52 #include <sys/pioctl.h>
53 #include <sys/namei.h>
54 #include <sys/sf_buf.h>
55 #include <sys/syscallsubr.h>
56 #include <sys/sysent.h>
58 #include <sys/sysctl.h>
60 #include <sys/vnode.h>
62 #include <sys/ktrace.h>
66 #include <vm/vm_param.h>
68 #include <vm/vm_page.h>
69 #include <vm/vm_map.h>
70 #include <vm/vm_kern.h>
71 #include <vm/vm_extern.h>
72 #include <vm/vm_object.h>
73 #include <vm/vm_pager.h>
75 #include <machine/reg.h>
77 MALLOC_DEFINE(M_PARGS, "proc-args", "Process arguments");
79 static int sysctl_kern_ps_strings(SYSCTL_HANDLER_ARGS);
80 static int sysctl_kern_usrstack(SYSCTL_HANDLER_ARGS);
81 static int sysctl_kern_stackprot(SYSCTL_HANDLER_ARGS);
82 static int do_execve(struct thread *td, char *fname, char **argv,
83 char **envv, struct mac *mac_p);
85 /* XXX This should be vm_size_t. */
86 SYSCTL_PROC(_kern, KERN_PS_STRINGS, ps_strings, CTLTYPE_ULONG|CTLFLAG_RD,
87 NULL, 0, sysctl_kern_ps_strings, "LU", "");
89 /* XXX This should be vm_size_t. */
90 SYSCTL_PROC(_kern, KERN_USRSTACK, usrstack, CTLTYPE_ULONG|CTLFLAG_RD,
91 NULL, 0, sysctl_kern_usrstack, "LU", "");
93 SYSCTL_PROC(_kern, OID_AUTO, stackprot, CTLTYPE_INT|CTLFLAG_RD,
94 NULL, 0, sysctl_kern_stackprot, "I", "");
96 u_long ps_arg_cache_limit = PAGE_SIZE / 16;
97 SYSCTL_ULONG(_kern, OID_AUTO, ps_arg_cache_limit, CTLFLAG_RW,
98 &ps_arg_cache_limit, 0, "");
101 sysctl_kern_ps_strings(SYSCTL_HANDLER_ARGS)
107 #if defined(__amd64__) || defined(__ia64__)
108 if (req->oldlen == sizeof(unsigned int)) {
110 val = (unsigned int)p->p_sysent->sv_psstrings;
111 error = SYSCTL_OUT(req, &val, sizeof(val));
114 error = SYSCTL_OUT(req, &p->p_sysent->sv_psstrings,
115 sizeof(p->p_sysent->sv_psstrings));
120 sysctl_kern_usrstack(SYSCTL_HANDLER_ARGS)
126 #if defined(__amd64__) || defined(__ia64__)
127 if (req->oldlen == sizeof(unsigned int)) {
129 val = (unsigned int)p->p_sysent->sv_usrstack;
130 error = SYSCTL_OUT(req, &val, sizeof(val));
133 error = SYSCTL_OUT(req, &p->p_sysent->sv_usrstack,
134 sizeof(p->p_sysent->sv_usrstack));
139 sysctl_kern_stackprot(SYSCTL_HANDLER_ARGS)
144 return (SYSCTL_OUT(req, &p->p_sysent->sv_stackprot,
145 sizeof(p->p_sysent->sv_stackprot)));
149 * Each of the items is a pointer to a `const struct execsw', hence the
150 * double pointer here.
152 static const struct execsw **execsw;
154 #ifndef _SYS_SYSPROTO_H_
168 struct execve_args /* {
175 return (kern_execve(td, uap->fname, uap->argv, uap->envv, NULL));
178 #ifndef _SYS_SYSPROTO_H_
179 struct __mac_execve_args {
191 __mac_execve(td, uap)
193 struct __mac_execve_args /* {
202 return (kern_execve(td, uap->fname, uap->argv, uap->envv,
210 kern_execve(td, fname, argv, envv, mac_p)
217 struct proc *p = td->td_proc;
220 if (p->p_flag & P_HADTHREADS) {
222 if (thread_single(SINGLE_BOUNDARY)) {
224 return (ERESTART); /* Try again later. */
229 error = do_execve(td, fname, argv, envv, mac_p);
231 if (p->p_flag & P_HADTHREADS) {
234 * If success, we upgrade to SINGLE_EXIT state to
235 * force other threads to suicide.
238 thread_single(SINGLE_EXIT);
248 * In-kernel implementation of execve(). All arguments are assumed to be
249 * userspace pointers from the passed thread.
254 do_execve(td, fname, argv, envv, mac_p)
261 struct proc *p = td->td_proc;
262 struct nameidata nd, *ndp;
263 struct ucred *newcred = NULL, *oldcred;
264 struct uidinfo *euip;
265 register_t *stack_base;
267 struct image_params image_params, *imgp;
269 int (*img_first)(struct image_params *);
270 struct pargs *oldargs = NULL, *newargs = NULL;
271 struct sigacts *oldsigacts, *newsigacts;
273 struct vnode *tracevp = NULL;
274 struct ucred *tracecred = NULL;
276 struct vnode *textvp = NULL;
277 int credential_changing;
280 struct label *interplabel = NULL;
284 imgp = &image_params;
287 * Lock the process and set the P_INEXEC flag to indicate that
288 * it should be left alone until we're done here. This is
289 * necessary to avoid race conditions - e.g. in ptrace() -
290 * that might allow a local user to illicitly obtain elevated
294 KASSERT((p->p_flag & P_INEXEC) == 0,
295 ("%s(): process already has P_INEXEC flag", __func__));
296 p->p_flag |= P_INEXEC;
300 * Initialize part of the common data
303 imgp->userspace_argv = argv;
304 imgp->userspace_envv = envv;
305 imgp->execlabel = NULL;
307 imgp->argc = imgp->envc = 0;
309 imgp->entry_addr = 0;
310 imgp->vmspace_destroyed = 0;
311 imgp->interpreted = 0;
312 imgp->interpreter_name[0] = '\0';
313 imgp->auxargs = NULL;
316 imgp->firstpage = NULL;
317 imgp->ps_strings = 0;
318 imgp->auxarg_size = 0;
321 error = mac_execve_enter(imgp, mac_p);
329 * Allocate temporary demand zeroed space for argument and
330 * environment strings
332 imgp->stringbase = (char *)kmem_alloc_wait(exec_map, ARG_MAX);
333 if (imgp->stringbase == NULL) {
338 imgp->stringp = imgp->stringbase;
339 imgp->stringspace = ARG_MAX;
340 imgp->image_header = NULL;
343 * Translate the file name. namei() returns a vnode pointer
344 * in ni_vp amoung other things.
347 NDINIT(ndp, LOOKUP, LOCKLEAF | FOLLOW | SAVENAME,
348 UIO_USERSPACE, fname, td);
355 kmem_free_wakeup(exec_map, (vm_offset_t)imgp->stringbase,
360 imgp->vp = ndp->ni_vp;
364 * Check file permissions (also 'opens' file)
366 error = exec_check_permissions(imgp);
368 goto exec_fail_dealloc;
370 if (VOP_GETVOBJECT(imgp->vp, &imgp->object) == 0)
371 vm_object_reference(imgp->object);
374 * Set VV_TEXT now so no one can write to the executable while we're
377 * Remember if this was set before and unset it in case this is not
378 * actually an executable image.
380 textset = imgp->vp->v_vflag & VV_TEXT;
381 imgp->vp->v_vflag |= VV_TEXT;
383 error = exec_map_first_page(imgp);
385 goto exec_fail_dealloc;
388 * If the current process has a special image activator it
389 * wants to try first, call it. For example, emulating shell
390 * scripts differently.
393 if ((img_first = imgp->proc->p_sysent->sv_imgact_try) != NULL)
394 error = img_first(imgp);
397 * Loop through the list of image activators, calling each one.
398 * An activator returns -1 if there is no match, 0 on success,
399 * and an error otherwise.
401 for (i = 0; error == -1 && execsw[i]; ++i) {
402 if (execsw[i]->ex_imgact == NULL ||
403 execsw[i]->ex_imgact == img_first) {
406 error = (*execsw[i]->ex_imgact)(imgp);
412 imgp->vp->v_vflag &= ~VV_TEXT;
415 goto exec_fail_dealloc;
419 * Special interpreter operation, cleanup and loop up to try to
420 * activate the interpreter.
422 if (imgp->interpreted) {
423 exec_unmap_first_page(imgp);
425 * VV_TEXT needs to be unset for scripts. There is a short
426 * period before we determine that something is a script where
427 * VV_TEXT will be set. The vnode lock is held over this
428 * entire period so nothing should illegitimately be blocked.
430 imgp->vp->v_vflag &= ~VV_TEXT;
431 /* free name buffer and old vnode */
432 NDFREE(ndp, NDF_ONLY_PNBUF);
434 interplabel = mac_vnode_label_alloc();
435 mac_copy_vnode_label(ndp->ni_vp->v_label, interplabel);
438 vm_object_deallocate(imgp->object);
440 /* set new name to that of the interpreter */
441 NDINIT(ndp, LOOKUP, LOCKLEAF | FOLLOW | SAVENAME,
442 UIO_SYSSPACE, imgp->interpreter_name, td);
447 * Copy out strings (args and env) and initialize stack base
449 if (p->p_sysent->sv_copyout_strings)
450 stack_base = (*p->p_sysent->sv_copyout_strings)(imgp);
452 stack_base = exec_copyout_strings(imgp);
455 * If custom stack fixup routine present for this process
456 * let it do the stack setup.
457 * Else stuff argument count as first item on stack
459 if (p->p_sysent->sv_fixup != NULL)
460 (*p->p_sysent->sv_fixup)(&stack_base, imgp);
462 suword(--stack_base, imgp->argc);
465 * For security and other reasons, the file descriptor table cannot
466 * be shared after an exec.
468 FILEDESC_LOCK(p->p_fd);
469 if (p->p_fd->fd_refcnt > 1) {
470 struct filedesc *tmp;
472 tmp = fdcopy(td->td_proc->p_fd);
473 FILEDESC_UNLOCK(p->p_fd);
477 FILEDESC_UNLOCK(p->p_fd);
480 * Malloc things before we need locks.
483 euip = uifind(attr.va_uid);
484 i = imgp->endargs - imgp->stringbase;
485 if (ps_arg_cache_limit >= i + sizeof(struct pargs))
486 newargs = pargs_alloc(i);
488 /* close files on exec */
491 /* Get a reference to the vnode prior to locking the proc */
495 * For security and other reasons, signal handlers cannot
496 * be shared after an exec. The new process gets a copy of the old
497 * handlers. In execsigs(), the new process will have its signals
501 if (sigacts_shared(p->p_sigacts)) {
502 oldsigacts = p->p_sigacts;
504 newsigacts = sigacts_alloc();
505 sigacts_copy(newsigacts, oldsigacts);
507 p->p_sigacts = newsigacts;
514 /* reset caught signals */
517 /* name this process - nameiexec(p, ndp) */
518 len = min(ndp->ni_cnd.cn_namelen,MAXCOMLEN);
519 bcopy(ndp->ni_cnd.cn_nameptr, p->p_comm, len);
523 * mark as execed, wakeup the process that vforked (if any) and tell
524 * it that it now has its own resources back
527 if (p->p_pptr && (p->p_flag & P_PPWAIT)) {
528 p->p_flag &= ~P_PPWAIT;
533 * Implement image setuid/setgid.
535 * Don't honor setuid/setgid if the filesystem prohibits it or if
536 * the process is being traced.
538 * XXXMAC: For the time being, use NOSUID to also prohibit
539 * transitions on the file system.
541 oldcred = p->p_ucred;
542 credential_changing = 0;
543 credential_changing |= (attr.va_mode & VSUID) && oldcred->cr_uid !=
545 credential_changing |= (attr.va_mode & VSGID) && oldcred->cr_gid !=
548 will_transition = mac_execve_will_transition(oldcred, imgp->vp,
550 credential_changing |= will_transition;
553 if (credential_changing &&
554 (imgp->vp->v_mount->mnt_flag & MNT_NOSUID) == 0 &&
555 (p->p_flag & P_TRACED) == 0) {
557 * Turn off syscall tracing for set-id programs, except for
558 * root. Record any set-id flags first to make sure that
559 * we do not regain any tracing during a possible block.
563 if (p->p_tracevp != NULL && suser_cred(oldcred, SUSER_ALLOWJAIL)) {
564 mtx_lock(&ktrace_mtx);
566 tracevp = p->p_tracevp;
568 tracecred = p->p_tracecred;
569 p->p_tracecred = NULL;
570 mtx_unlock(&ktrace_mtx);
574 * Close any file descriptors 0..2 that reference procfs,
575 * then make sure file descriptors 0..2 are in use.
577 * setugidsafety() may call closef() and then pfind()
578 * which may grab the process lock.
579 * fdcheckstd() may call falloc() which may block to
580 * allocate memory, so temporarily drop the process lock.
584 error = fdcheckstd(td);
589 * Set the new credentials.
591 crcopy(newcred, oldcred);
592 if (attr.va_mode & VSUID)
593 change_euid(newcred, euip);
594 if (attr.va_mode & VSGID)
595 change_egid(newcred, attr.va_gid);
597 if (will_transition) {
598 mac_execve_transition(oldcred, newcred, imgp->vp,
603 * Implement correct POSIX saved-id behavior.
605 * XXXMAC: Note that the current logic will save the
606 * uid and gid if a MAC domain transition occurs, even
607 * though maybe it shouldn't.
609 change_svuid(newcred, newcred->cr_uid);
610 change_svgid(newcred, newcred->cr_gid);
611 p->p_ucred = newcred;
614 if (oldcred->cr_uid == oldcred->cr_ruid &&
615 oldcred->cr_gid == oldcred->cr_rgid)
616 p->p_flag &= ~P_SUGID;
618 * Implement correct POSIX saved-id behavior.
620 * XXX: It's not clear that the existing behavior is
621 * POSIX-compliant. A number of sources indicate that the
622 * saved uid/gid should only be updated if the new ruid is
623 * not equal to the old ruid, or the new euid is not equal
624 * to the old euid and the new euid is not equal to the old
625 * ruid. The FreeBSD code always updates the saved uid/gid.
626 * Also, this code uses the new (replaced) euid and egid as
627 * the source, which may or may not be the right ones to use.
629 if (oldcred->cr_svuid != oldcred->cr_uid ||
630 oldcred->cr_svgid != oldcred->cr_gid) {
631 crcopy(newcred, oldcred);
632 change_svuid(newcred, newcred->cr_uid);
633 change_svgid(newcred, newcred->cr_gid);
634 p->p_ucred = newcred;
640 * Store the vp for use in procfs. This vnode was referenced prior
641 * to locking the proc lock.
643 textvp = p->p_textvp;
644 p->p_textvp = ndp->ni_vp;
647 * Notify others that we exec'd, and clear the P_INEXEC flag
648 * as we're now a bona fide freshly-execed process.
650 KNOTE_LOCKED(&p->p_klist, NOTE_EXEC);
651 p->p_flag &= ~P_INEXEC;
654 * If tracing the process, trap to debugger so breakpoints
655 * can be set before the program executes.
656 * Use tdsignal to deliver signal to current thread, use
657 * psignal may cause the signal to be delivered to wrong thread
658 * because that thread will exit, remember we are going to enter
659 * single thread mode.
661 if (p->p_flag & P_TRACED)
662 tdsignal(td, SIGTRAP, SIGTARGET_TD);
664 /* clear "fork but no exec" flag, as we _are_ execing */
665 p->p_acflag &= ~AFORK;
667 /* Free any previous argument cache */
671 /* Cache arguments if they fit inside our allowance */
672 if (ps_arg_cache_limit >= i + sizeof(struct pargs)) {
673 bcopy(imgp->stringbase, newargs->ar_args, i);
679 /* Set values passed into the program in registers. */
680 if (p->p_sysent->sv_setregs)
681 (*p->p_sysent->sv_setregs)(td, imgp->entry_addr,
682 (u_long)(uintptr_t)stack_base, imgp->ps_strings);
684 exec_setregs(td, imgp->entry_addr,
685 (u_long)(uintptr_t)stack_base, imgp->ps_strings);
689 * Free any resources malloc'd earlier that we didn't use.
697 * Handle deferred decrement of ref counts.
701 if (ndp->ni_vp && error != 0)
706 if (tracecred != NULL)
713 if (oldsigacts != NULL)
714 sigacts_free(oldsigacts);
719 * free various allocated resources
721 if (imgp->firstpage != NULL)
722 exec_unmap_first_page(imgp);
724 if (imgp->vp != NULL) {
725 NDFREE(ndp, NDF_ONLY_PNBUF);
729 if (imgp->stringbase != NULL)
730 kmem_free_wakeup(exec_map, (vm_offset_t)imgp->stringbase,
733 if (imgp->object != NULL)
734 vm_object_deallocate(imgp->object);
738 * Stop the process here if its stop event mask has
739 * the S_EXEC bit set.
741 STOPEVENT(p, S_EXEC, 0);
746 /* we're done here, clear P_INEXEC */
748 p->p_flag &= ~P_INEXEC;
751 if (imgp->vmspace_destroyed) {
752 /* sorry, no more process anymore. exit gracefully */
754 mac_execve_exit(imgp);
755 if (interplabel != NULL)
756 mac_vnode_label_free(interplabel);
759 exit1(td, W_EXITCODE(0, SIGABRT));
765 mac_execve_exit(imgp);
766 if (interplabel != NULL)
767 mac_vnode_label_free(interplabel);
774 exec_map_first_page(imgp)
775 struct image_params *imgp;
779 vm_page_t ma[VM_INITIAL_PAGEIN];
784 if (imgp->firstpage != NULL)
785 exec_unmap_first_page(imgp);
787 VOP_GETVOBJECT(imgp->vp, &object);
788 VM_OBJECT_LOCK(object);
789 ma[0] = vm_page_grab(object, 0, VM_ALLOC_NORMAL | VM_ALLOC_RETRY);
790 if ((ma[0]->valid & VM_PAGE_BITS_ALL) != VM_PAGE_BITS_ALL) {
791 initial_pagein = VM_INITIAL_PAGEIN;
792 if (initial_pagein > object->size)
793 initial_pagein = object->size;
794 for (i = 1; i < initial_pagein; i++) {
795 if ((ma[i] = vm_page_lookup(object, i)) != NULL) {
798 vm_page_lock_queues();
799 if ((ma[i]->flags & PG_BUSY) || ma[i]->busy) {
800 vm_page_unlock_queues();
804 vm_page_unlock_queues();
806 ma[i] = vm_page_alloc(object, i,
813 rv = vm_pager_get_pages(object, ma, initial_pagein, 0);
814 ma[0] = vm_page_lookup(object, 0);
815 if ((rv != VM_PAGER_OK) || (ma[0] == NULL) ||
816 (ma[0]->valid == 0)) {
818 vm_page_lock_queues();
819 pmap_remove_all(ma[0]);
821 vm_page_unlock_queues();
823 VM_OBJECT_UNLOCK(object);
827 vm_page_lock_queues();
829 vm_page_wakeup(ma[0]);
830 vm_page_unlock_queues();
831 VM_OBJECT_UNLOCK(object);
833 imgp->firstpage = sf_buf_alloc(ma[0], 0);
834 imgp->image_header = (char *)sf_buf_kva(imgp->firstpage);
840 exec_unmap_first_page(imgp)
841 struct image_params *imgp;
845 if (imgp->firstpage != NULL) {
846 m = sf_buf_page(imgp->firstpage);
847 sf_buf_free(imgp->firstpage);
848 imgp->firstpage = NULL;
849 vm_page_lock_queues();
851 vm_page_unlock_queues();
856 * Destroy old address space, and allocate a new stack
857 * The new stack is only SGROWSIZ large because it is grown
858 * automatically in trap.c.
861 exec_new_vmspace(imgp, sv)
862 struct image_params *imgp;
863 struct sysentvec *sv;
866 struct proc *p = imgp->proc;
867 struct vmspace *vmspace = p->p_vmspace;
868 vm_offset_t stack_addr;
873 imgp->vmspace_destroyed = 1;
875 /* Called with Giant held, do not depend on it! */
876 EVENTHANDLER_INVOKE(process_exec, p);
879 * Here is as good a place as any to do any resource limit cleanups.
880 * This is needed if a 64 bit binary exec's a 32 bit binary - the
881 * data size limit may need to be changed to a value that makes
882 * sense for the 32 bit binary.
884 if (sv->sv_fixlimits != NULL)
885 sv->sv_fixlimits(imgp);
888 * Blow away entire process VM, if address space not shared,
889 * otherwise, create a new VM space so that other threads are
892 map = &vmspace->vm_map;
893 if (vmspace->vm_refcnt == 1 && vm_map_min(map) == sv->sv_minuser &&
894 vm_map_max(map) == sv->sv_maxuser) {
896 pmap_remove_pages(vmspace_pmap(vmspace), vm_map_min(map),
898 vm_map_remove(map, vm_map_min(map), vm_map_max(map));
900 vmspace_exec(p, sv->sv_minuser, sv->sv_maxuser);
901 vmspace = p->p_vmspace;
902 map = &vmspace->vm_map;
905 /* Allocate a new stack */
906 stack_addr = sv->sv_usrstack - maxssiz;
907 error = vm_map_stack(map, stack_addr, (vm_size_t)maxssiz,
908 sv->sv_stackprot, VM_PROT_ALL, MAP_STACK_GROWS_DOWN);
913 /* Allocate a new register stack */
914 stack_addr = IA64_BACKINGSTORE;
915 error = vm_map_stack(map, stack_addr, (vm_size_t)maxssiz,
916 sv->sv_stackprot, VM_PROT_ALL, MAP_STACK_GROWS_UP);
921 /* vm_ssize and vm_maxsaddr are somewhat antiquated concepts in the
922 * VM_STACK case, but they are still used to monitor the size of the
923 * process stack so we can check the stack rlimit.
925 vmspace->vm_ssize = sgrowsiz >> PAGE_SHIFT;
926 vmspace->vm_maxsaddr = (char *)sv->sv_usrstack - maxssiz;
932 * Copy out argument and environment strings from the old process
933 * address space into the temporary string buffer.
936 exec_extract_strings(imgp)
937 struct image_params *imgp;
945 * extract arguments first
948 argv = imgp->userspace_argv;
951 argp = (caddr_t)(intptr_t)fuword(argv);
952 if (argp == (caddr_t)-1)
960 if (argp == (caddr_t)-1)
962 if ((error = copyinstr(argp, imgp->stringp,
963 imgp->stringspace, &length))) {
964 if (error == ENAMETOOLONG)
968 imgp->stringspace -= length;
969 imgp->stringp += length;
971 } while ((argp = (caddr_t)(intptr_t)fuword(argv++)));
976 imgp->endargs = imgp->stringp;
979 * extract environment strings
982 envv = imgp->userspace_envv;
985 while ((envp = (caddr_t)(intptr_t)fuword(envv++))) {
986 if (envp == (caddr_t)-1)
988 if ((error = copyinstr(envp, imgp->stringp,
989 imgp->stringspace, &length))) {
990 if (error == ENAMETOOLONG)
994 imgp->stringspace -= length;
995 imgp->stringp += length;
1004 * Copy strings out to the new process address space, constructing
1005 * new arg and env vector tables. Return a pointer to the base
1006 * so that it can be used as the initial stack pointer.
1009 exec_copyout_strings(imgp)
1010 struct image_params *imgp;
1014 char *stringp, *destp;
1015 register_t *stack_base;
1016 struct ps_strings *arginfo;
1021 * Calculate string base and vector table pointers.
1022 * Also deal with signal trampoline code for this exec type.
1026 arginfo = (struct ps_strings *)p->p_sysent->sv_psstrings;
1027 if (p->p_sysent->sv_szsigcode != NULL)
1028 szsigcode = *(p->p_sysent->sv_szsigcode);
1029 destp = (caddr_t)arginfo - szsigcode - SPARE_USRSPACE -
1030 roundup((ARG_MAX - imgp->stringspace), sizeof(char *));
1036 copyout(p->p_sysent->sv_sigcode, ((caddr_t)arginfo -
1037 szsigcode), szsigcode);
1040 * If we have a valid auxargs ptr, prepare some room
1043 if (imgp->auxargs) {
1045 * 'AT_COUNT*2' is size for the ELF Auxargs data. This is for
1046 * lower compatibility.
1048 imgp->auxarg_size = (imgp->auxarg_size) ? imgp->auxarg_size :
1051 * The '+ 2' is for the null pointers at the end of each of
1052 * the arg and env vector sets,and imgp->auxarg_size is room
1053 * for argument of Runtime loader.
1055 vectp = (char **)(destp - (imgp->argc + imgp->envc + 2 +
1056 imgp->auxarg_size) * sizeof(char *));
1060 * The '+ 2' is for the null pointers at the end of each of
1061 * the arg and env vector sets
1063 vectp = (char **)(destp - (imgp->argc + imgp->envc + 2) *
1067 * vectp also becomes our initial stack base
1069 stack_base = (register_t *)vectp;
1071 stringp = imgp->stringbase;
1076 * Copy out strings - arguments and environment.
1078 copyout(stringp, destp, ARG_MAX - imgp->stringspace);
1081 * Fill in "ps_strings" struct for ps, w, etc.
1083 suword(&arginfo->ps_argvstr, (long)(intptr_t)vectp);
1084 suword(&arginfo->ps_nargvstr, argc);
1087 * Fill in argument portion of vector table.
1089 for (; argc > 0; --argc) {
1090 suword(vectp++, (long)(intptr_t)destp);
1091 while (*stringp++ != 0)
1096 /* a null vector table pointer separates the argp's from the envp's */
1099 suword(&arginfo->ps_envstr, (long)(intptr_t)vectp);
1100 suword(&arginfo->ps_nenvstr, envc);
1103 * Fill in environment portion of vector table.
1105 for (; envc > 0; --envc) {
1106 suword(vectp++, (long)(intptr_t)destp);
1107 while (*stringp++ != 0)
1112 /* end of vector table is a null pointer */
1115 return (stack_base);
1119 * Check permissions of file to execute.
1120 * Called with imgp->vp locked.
1121 * Return 0 for success or error code on failure.
1124 exec_check_permissions(imgp)
1125 struct image_params *imgp;
1127 struct vnode *vp = imgp->vp;
1128 struct vattr *attr = imgp->attr;
1132 td = curthread; /* XXXKSE */
1134 /* Get file attributes */
1135 error = VOP_GETATTR(vp, attr, td->td_ucred, td);
1140 error = mac_check_vnode_exec(td->td_ucred, imgp->vp, imgp);
1146 * 1) Check if file execution is disabled for the filesystem that this
1148 * 2) Insure that at least one execute bit is on - otherwise root
1149 * will always succeed, and we don't want to happen unless the
1150 * file really is executable.
1151 * 3) Insure that the file is a regular file.
1153 if ((vp->v_mount->mnt_flag & MNT_NOEXEC) ||
1154 ((attr->va_mode & 0111) == 0) ||
1155 (attr->va_type != VREG))
1159 * Zero length files can't be exec'd
1161 if (attr->va_size == 0)
1165 * Check for execute permission to file based on current credentials.
1167 error = VOP_ACCESS(vp, VEXEC, td->td_ucred, td);
1172 * Check number of open-for-writes on the file and deny execution
1175 if (vp->v_writecount)
1179 * Call filesystem specific open routine (which does nothing in the
1182 error = VOP_OPEN(vp, FREAD, td->td_ucred, td, -1);
1187 * Exec handler registration
1190 exec_register(execsw_arg)
1191 const struct execsw *execsw_arg;
1193 const struct execsw **es, **xs, **newexecsw;
1194 int count = 2; /* New slot and trailing NULL */
1197 for (es = execsw; *es; es++)
1199 newexecsw = malloc(count * sizeof(*es), M_TEMP, M_WAITOK);
1200 if (newexecsw == NULL)
1204 for (es = execsw; *es; es++)
1209 free(execsw, M_TEMP);
1215 exec_unregister(execsw_arg)
1216 const struct execsw *execsw_arg;
1218 const struct execsw **es, **xs, **newexecsw;
1222 panic("unregister with no handlers left?\n");
1224 for (es = execsw; *es; es++) {
1225 if (*es == execsw_arg)
1230 for (es = execsw; *es; es++)
1231 if (*es != execsw_arg)
1233 newexecsw = malloc(count * sizeof(*es), M_TEMP, M_WAITOK);
1234 if (newexecsw == NULL)
1237 for (es = execsw; *es; es++)
1238 if (*es != execsw_arg)
1242 free(execsw, M_TEMP);