Add userland UDF support based on mount_cd9660
[dragonfly.git] / sys / kern / kern_exec.c
CommitLineData
984263bc
MD
1/*
2 * Copyright (c) 1993, David Greenman
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
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.
13 *
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
24 * SUCH DAMAGE.
25 *
26 * $FreeBSD: src/sys/kern/kern_exec.c,v 1.107.2.15 2002/07/30 15:40:46 nectar Exp $
41a01a4d 27 * $DragonFly: src/sys/kern/kern_exec.c,v 1.20 2004/03/01 06:33:17 dillon Exp $
984263bc
MD
28 */
29
30#include <sys/param.h>
31#include <sys/systm.h>
32#include <sys/sysproto.h>
33#include <sys/kernel.h>
34#include <sys/mount.h>
35#include <sys/filedesc.h>
36#include <sys/fcntl.h>
37#include <sys/acct.h>
38#include <sys/exec.h>
39#include <sys/imgact.h>
40#include <sys/imgact_elf.h>
2bd9d75c 41#include <sys/kern_syscall.h>
984263bc
MD
42#include <sys/wait.h>
43#include <sys/malloc.h>
44#include <sys/proc.h>
45#include <sys/signalvar.h>
46#include <sys/pioctl.h>
47#include <sys/namei.h>
48#include <sys/sysent.h>
49#include <sys/shm.h>
50#include <sys/sysctl.h>
51#include <sys/vnode.h>
52#include <sys/aio.h>
53
54#include <vm/vm.h>
55#include <vm/vm_param.h>
56#include <sys/lock.h>
57#include <vm/pmap.h>
58#include <vm/vm_page.h>
59#include <vm/vm_map.h>
60#include <vm/vm_kern.h>
61#include <vm/vm_extern.h>
62#include <vm/vm_object.h>
63#include <vm/vm_pager.h>
64
65#include <sys/user.h>
66#include <machine/reg.h>
67
68MALLOC_DEFINE(M_PARGS, "proc-args", "Process arguments");
69
402ed7e1 70static register_t *exec_copyout_strings (struct image_params *);
984263bc
MD
71
72/* XXX This should be vm_size_t. */
73static u_long ps_strings = PS_STRINGS;
74SYSCTL_ULONG(_kern, KERN_PS_STRINGS, ps_strings, CTLFLAG_RD, &ps_strings, 0, "");
75
76/* XXX This should be vm_size_t. */
77static u_long usrstack = USRSTACK;
78SYSCTL_ULONG(_kern, KERN_USRSTACK, usrstack, CTLFLAG_RD, &usrstack, 0, "");
79
80u_long ps_arg_cache_limit = PAGE_SIZE / 16;
81SYSCTL_LONG(_kern, OID_AUTO, ps_arg_cache_limit, CTLFLAG_RW,
82 &ps_arg_cache_limit, 0, "");
83
84int ps_argsopen = 1;
85SYSCTL_INT(_kern, OID_AUTO, ps_argsopen, CTLFLAG_RW, &ps_argsopen, 0, "");
86
2bd9d75c
DRJ
87void print_execve_args(struct image_args *args);
88int debug_execve_args = 0;
89SYSCTL_INT(_kern, OID_AUTO, debug_execve_args, CTLFLAG_RW, &debug_execve_args,
90 0, "");
91
92void
93print_execve_args(struct image_args *args)
94{
95 char *cp;
96 int ndx;
97
98 cp = args->begin_argv;
99 for (ndx = 0; ndx < args->argc; ndx++) {
100 printf("\targv[%d]: %s\n", ndx, cp);
101 while (*cp++ != '\0');
102 }
103 for (ndx = 0; ndx < args->envc; ndx++) {
104 printf("\tenvv[%d]: %s\n", ndx, cp);
105 while (*cp++ != '\0');
106 }
107}
108
984263bc
MD
109/*
110 * Each of the items is a pointer to a `const struct execsw', hence the
111 * double pointer here.
112 */
113static const struct execsw **execsw;
114
984263bc 115int
2bd9d75c 116kern_execve(struct nameidata *ndp, struct image_args *args)
984263bc 117{
dadab5e9
MD
118 struct thread *td = curthread;
119 struct proc *p = td->td_proc;
984263bc
MD
120 register_t *stack_base;
121 int error, len, i;
122 struct image_params image_params, *imgp;
123 struct vattr attr;
402ed7e1 124 int (*img_first) (struct image_params *);
984263bc 125
2bd9d75c
DRJ
126 if (debug_execve_args) {
127 printf("%s()\n", __func__);
128 print_execve_args(args);
129 }
130
dadab5e9 131 KKASSERT(p);
984263bc
MD
132 imgp = &image_params;
133
134 /*
135 * Lock the process and set the P_INEXEC flag to indicate that
136 * it should be left alone until we're done here. This is
137 * necessary to avoid race conditions - e.g. in ptrace() -
138 * that might allow a local user to illicitly obtain elevated
139 * privileges.
140 */
141 p->p_flag |= P_INEXEC;
142
143 /*
144 * Initialize part of the common data
145 */
146 imgp->proc = p;
2bd9d75c 147 imgp->args = args;
984263bc 148 imgp->attr = &attr;
984263bc 149 imgp->entry_addr = 0;
29802dbb 150 imgp->resident = 0;
984263bc
MD
151 imgp->vmspace_destroyed = 0;
152 imgp->interpreted = 0;
2abfe22f 153 imgp->interpreter_name[0] = 0;
984263bc
MD
154 imgp->auxargs = NULL;
155 imgp->vp = NULL;
156 imgp->firstpage = NULL;
157 imgp->ps_strings = 0;
158
159 /*
160 * Allocate temporary demand zeroed space for argument and
161 * environment strings
162 */
2bd9d75c
DRJ
163 imgp->image_header = (char *)kmem_alloc_wait(exec_map, PAGE_SIZE);
164 if (imgp->image_header == NULL) {
984263bc
MD
165 error = ENOMEM;
166 goto exec_fail;
167 }
2bd9d75c
DRJ
168
169interpret:
984263bc
MD
170
171 /*
172 * Translate the file name. namei() returns a vnode pointer
173 * in ni_vp amoung other things.
174 */
984263bc
MD
175 error = namei(ndp);
176 if (error) {
2bd9d75c
DRJ
177 kmem_free_wakeup(exec_map, (vm_offset_t)imgp->image_header,
178 PAGE_SIZE);
984263bc
MD
179 goto exec_fail;
180 }
181
182 imgp->vp = ndp->ni_vp;
984263bc
MD
183
184 /*
185 * Check file permissions (also 'opens' file)
186 */
187 error = exec_check_permissions(imgp);
188 if (error) {
41a01a4d 189 VOP_UNLOCK(imgp->vp, NULL, 0, td);
984263bc
MD
190 goto exec_fail_dealloc;
191 }
192
193 error = exec_map_first_page(imgp);
41a01a4d 194 VOP_UNLOCK(imgp->vp, NULL, 0, td);
984263bc
MD
195 if (error)
196 goto exec_fail_dealloc;
197
2bd9d75c
DRJ
198 if (debug_execve_args && imgp->interpreted) {
199 printf(" target is interpreted -- recursive pass\n");
200 printf(" interpreter: %s\n", imgp->interpreter_name);
201 print_execve_args(args);
202 }
203
984263bc
MD
204 /*
205 * If the current process has a special image activator it
206 * wants to try first, call it. For example, emulating shell
207 * scripts differently.
208 */
209 error = -1;
210 if ((img_first = imgp->proc->p_sysent->sv_imgact_try) != NULL)
211 error = img_first(imgp);
212
29802dbb
MD
213 /*
214 * If the vnode has a registered vmspace, exec the vmspace
215 */
216 if (error == -1 && imgp->vp->v_resident) {
217 error = exec_resident_imgact(imgp);
218 }
219
984263bc
MD
220 /*
221 * Loop through the list of image activators, calling each one.
222 * An activator returns -1 if there is no match, 0 on success,
223 * and an error otherwise.
224 */
225 for (i = 0; error == -1 && execsw[i]; ++i) {
226 if (execsw[i]->ex_imgact == NULL ||
227 execsw[i]->ex_imgact == img_first) {
228 continue;
229 }
230 error = (*execsw[i]->ex_imgact)(imgp);
231 }
232
233 if (error) {
234 if (error == -1)
235 error = ENOEXEC;
236 goto exec_fail_dealloc;
237 }
238
239 /*
240 * Special interpreter operation, cleanup and loop up to try to
241 * activate the interpreter.
242 */
243 if (imgp->interpreted) {
244 exec_unmap_first_page(imgp);
245 /* free name buffer and old vnode */
246 NDFREE(ndp, NDF_ONLY_PNBUF);
247 vrele(ndp->ni_vp);
248 /* set new name to that of the interpreter */
2b69e610
MD
249 NDINIT(ndp, NAMEI_LOOKUP,
250 CNP_LOCKLEAF | CNP_FOLLOW | CNP_SAVENAME,
dadab5e9 251 UIO_SYSSPACE, imgp->interpreter_name, td);
984263bc
MD
252 goto interpret;
253 }
254
255 /*
256 * Copy out strings (args and env) and initialize stack base
257 */
258 stack_base = exec_copyout_strings(imgp);
259 p->p_vmspace->vm_minsaddr = (char *)stack_base;
260
261 /*
262 * If custom stack fixup routine present for this process
29802dbb
MD
263 * let it do the stack setup. If we are running a resident
264 * image there is no auxinfo or other image activator context
265 * so don't try to add fixups to the stack.
266 *
984263bc
MD
267 * Else stuff argument count as first item on stack
268 */
29802dbb 269 if (p->p_sysent->sv_fixup && imgp->resident == 0)
984263bc
MD
270 (*p->p_sysent->sv_fixup)(&stack_base, imgp);
271 else
2bd9d75c 272 suword(--stack_base, imgp->args->argc);
984263bc
MD
273
274 /*
275 * For security and other reasons, the file descriptor table cannot
276 * be shared after an exec.
277 */
278 if (p->p_fd->fd_refcnt > 1) {
279 struct filedesc *tmp;
280
281 tmp = fdcopy(p);
282 fdfree(p);
283 p->p_fd = tmp;
284 }
285
286 /*
287 * For security and other reasons, signal handlers cannot
288 * be shared after an exec. The new proces gets a copy of the old
289 * handlers. In execsigs(), the new process will have its signals
290 * reset.
291 */
292 if (p->p_procsig->ps_refcnt > 1) {
293 struct procsig *newprocsig;
294
295 MALLOC(newprocsig, struct procsig *, sizeof(struct procsig),
296 M_SUBPROC, M_WAITOK);
297 bcopy(p->p_procsig, newprocsig, sizeof(*newprocsig));
298 p->p_procsig->ps_refcnt--;
299 p->p_procsig = newprocsig;
300 p->p_procsig->ps_refcnt = 1;
301 if (p->p_sigacts == &p->p_addr->u_sigacts)
302 panic("shared procsig but private sigacts?");
303
304 p->p_addr->u_sigacts = *p->p_sigacts;
305 p->p_sigacts = &p->p_addr->u_sigacts;
306 }
307
308 /* Stop profiling */
309 stopprofclock(p);
310
311 /* close files on exec */
312 fdcloseexec(p);
313
314 /* reset caught signals */
315 execsigs(p);
316
317 /* name this process - nameiexec(p, ndp) */
318 len = min(ndp->ni_cnd.cn_namelen,MAXCOMLEN);
319 bcopy(ndp->ni_cnd.cn_nameptr, p->p_comm, len);
320 p->p_comm[len] = 0;
321
322 /*
323 * mark as execed, wakeup the process that vforked (if any) and tell
324 * it that it now has its own resources back
325 */
326 p->p_flag |= P_EXEC;
327 if (p->p_pptr && (p->p_flag & P_PPWAIT)) {
328 p->p_flag &= ~P_PPWAIT;
329 wakeup((caddr_t)p->p_pptr);
330 }
331
332 /*
333 * Implement image setuid/setgid.
334 *
335 * Don't honor setuid/setgid if the filesystem prohibits it or if
336 * the process is being traced.
337 */
338 if ((((attr.va_mode & VSUID) && p->p_ucred->cr_uid != attr.va_uid) ||
339 ((attr.va_mode & VSGID) && p->p_ucred->cr_gid != attr.va_gid)) &&
340 (imgp->vp->v_mount->mnt_flag & MNT_NOSUID) == 0 &&
341 (p->p_flag & P_TRACED) == 0) {
342 /*
343 * Turn off syscall tracing for set-id programs, except for
344 * root. Record any set-id flags first to make sure that
345 * we do not regain any tracing during a possible block.
346 */
41c20dac 347 setsugid();
dadab5e9 348 if (p->p_tracep && suser(td)) {
984263bc
MD
349 struct vnode *vtmp;
350
351 if ((vtmp = p->p_tracep) != NULL) {
352 p->p_tracep = NULL;
353 p->p_traceflag = 0;
354 vrele(vtmp);
355 }
356 }
357 /* Close any file descriptors 0..2 that reference procfs */
358 setugidsafety(p);
359 /* Make sure file descriptors 0..2 are in use. */
360 error = fdcheckstd(p);
361 if (error != 0)
362 goto exec_fail_dealloc;
363 /*
364 * Set the new credentials.
365 */
e9a372eb 366 cratom(&p->p_ucred);
984263bc 367 if (attr.va_mode & VSUID)
41c20dac 368 change_euid(attr.va_uid);
984263bc
MD
369 if (attr.va_mode & VSGID)
370 p->p_ucred->cr_gid = attr.va_gid;
98a7f915
MD
371
372 /*
373 * Clear local varsym variables
374 */
375 varsymset_clean(&p->p_varsymset);
984263bc 376 } else {
41c20dac
MD
377 if (p->p_ucred->cr_uid == p->p_ucred->cr_ruid &&
378 p->p_ucred->cr_gid == p->p_ucred->cr_rgid)
984263bc
MD
379 p->p_flag &= ~P_SUGID;
380 }
381
382 /*
383 * Implement correct POSIX saved-id behavior.
384 */
115ccd83
MD
385 if (p->p_ucred->cr_svuid != p->p_ucred->cr_uid ||
386 p->p_ucred->cr_svgid != p->p_ucred->cr_gid) {
387 cratom(&p->p_ucred);
388 p->p_ucred->cr_svuid = p->p_ucred->cr_uid;
389 p->p_ucred->cr_svgid = p->p_ucred->cr_gid;
390 }
984263bc
MD
391
392 /*
393 * Store the vp for use in procfs
394 */
395 if (p->p_textvp) /* release old reference */
396 vrele(p->p_textvp);
397 VREF(ndp->ni_vp);
398 p->p_textvp = ndp->ni_vp;
399
400 /*
401 * Notify others that we exec'd, and clear the P_INEXEC flag
402 * as we're now a bona fide freshly-execed process.
403 */
404 KNOTE(&p->p_klist, NOTE_EXEC);
405 p->p_flag &= ~P_INEXEC;
406
407 /*
408 * If tracing the process, trap to debugger so breakpoints
409 * can be set before the program executes.
410 */
411 STOPEVENT(p, S_EXEC, 0);
412
413 if (p->p_flag & P_TRACED)
414 psignal(p, SIGTRAP);
415
416 /* clear "fork but no exec" flag, as we _are_ execing */
417 p->p_acflag &= ~AFORK;
418
419 /* Set values passed into the program in registers. */
420 setregs(p, imgp->entry_addr, (u_long)(uintptr_t)stack_base,
421 imgp->ps_strings);
422
423 /* Free any previous argument cache */
424 if (p->p_args && --p->p_args->ar_ref == 0)
425 FREE(p->p_args, M_PARGS);
426 p->p_args = NULL;
427
428 /* Cache arguments if they fit inside our allowance */
2bd9d75c 429 i = imgp->args->begin_envv - imgp->args->begin_argv;
984263bc
MD
430 if (ps_arg_cache_limit >= i + sizeof(struct pargs)) {
431 MALLOC(p->p_args, struct pargs *, sizeof(struct pargs) + i,
432 M_PARGS, M_WAITOK);
433 p->p_args->ar_ref = 1;
434 p->p_args->ar_length = i;
2bd9d75c 435 bcopy(imgp->args->begin_argv, p->p_args->ar_args, i);
984263bc
MD
436 }
437
438exec_fail_dealloc:
439
440 /*
441 * free various allocated resources
442 */
443 if (imgp->firstpage)
444 exec_unmap_first_page(imgp);
445
2bd9d75c
DRJ
446 if (imgp->image_header != NULL)
447 kmem_free_wakeup(exec_map, (vm_offset_t)imgp->image_header,
448 PAGE_SIZE);
984263bc
MD
449
450 if (imgp->vp) {
451 NDFREE(ndp, NDF_ONLY_PNBUF);
452 vrele(imgp->vp);
453 }
454
455 if (error == 0)
456 return (0);
457
458exec_fail:
459 /* we're done here, clear P_INEXEC */
460 p->p_flag &= ~P_INEXEC;
461 if (imgp->vmspace_destroyed) {
462 /* sorry, no more process anymore. exit gracefully */
41c20dac 463 exit1(W_EXITCODE(0, SIGABRT));
984263bc
MD
464 /* NOT REACHED */
465 return(0);
466 } else {
467 return(error);
468 }
469}
470
2bd9d75c
DRJ
471/*
472 * execve() system call.
473 */
474int
475execve(struct execve_args *uap)
476{
477 struct thread *td = curthread;
478 struct nameidata nd;
479 struct image_args args;
480 int error;
481
482 NDINIT(&nd, NAMEI_LOOKUP, CNP_LOCKLEAF | CNP_FOLLOW | CNP_SAVENAME,
483 UIO_USERSPACE, uap->fname, td);
484
485 error = exec_copyin_args(&args, uap->fname, PATH_USERSPACE,
2abfe22f
MD
486 uap->argv, uap->envv);
487 if (error == 0)
488 error = kern_execve(&nd, &args);
2bd9d75c
DRJ
489
490 exec_free_args(&args);
491
492 /*
493 * The syscall result is returned in registers to the new program.
494 * Linux will register %edx as an atexit function and we must be
495 * sure to set it to 0. XXX
496 */
497 if (error == 0)
498 uap->sysmsg_result64 = 0;
499
500 return (error);
501}
502
984263bc 503int
41c20dac 504exec_map_first_page(struct image_params *imgp)
984263bc
MD
505{
506 int s, rv, i;
507 int initial_pagein;
508 vm_page_t ma[VM_INITIAL_PAGEIN];
509 vm_object_t object;
510
511
512 if (imgp->firstpage) {
513 exec_unmap_first_page(imgp);
514 }
515
516 VOP_GETVOBJECT(imgp->vp, &object);
517 s = splvm();
518
519 ma[0] = vm_page_grab(object, 0, VM_ALLOC_NORMAL | VM_ALLOC_RETRY);
520
521 if ((ma[0]->valid & VM_PAGE_BITS_ALL) != VM_PAGE_BITS_ALL) {
522 initial_pagein = VM_INITIAL_PAGEIN;
523 if (initial_pagein > object->size)
524 initial_pagein = object->size;
525 for (i = 1; i < initial_pagein; i++) {
526 if ((ma[i] = vm_page_lookup(object, i)) != NULL) {
527 if ((ma[i]->flags & PG_BUSY) || ma[i]->busy)
528 break;
529 if (ma[i]->valid)
530 break;
531 vm_page_busy(ma[i]);
532 } else {
533 ma[i] = vm_page_alloc(object, i, VM_ALLOC_NORMAL);
534 if (ma[i] == NULL)
535 break;
536 }
537 }
538 initial_pagein = i;
539
540 rv = vm_pager_get_pages(object, ma, initial_pagein, 0);
541 ma[0] = vm_page_lookup(object, 0);
542
543 if ((rv != VM_PAGER_OK) || (ma[0] == NULL) || (ma[0]->valid == 0)) {
544 if (ma[0]) {
545 vm_page_protect(ma[0], VM_PROT_NONE);
546 vm_page_free(ma[0]);
547 }
548 splx(s);
549 return EIO;
550 }
551 }
552
553 vm_page_wire(ma[0]);
554 vm_page_wakeup(ma[0]);
555 splx(s);
556
557 pmap_kenter((vm_offset_t) imgp->image_header, VM_PAGE_TO_PHYS(ma[0]));
558 imgp->firstpage = ma[0];
559
560 return 0;
561}
562
563void
564exec_unmap_first_page(imgp)
565 struct image_params *imgp;
566{
567 if (imgp->firstpage) {
568 pmap_kremove((vm_offset_t) imgp->image_header);
569 vm_page_unwire(imgp->firstpage, 1);
570 imgp->firstpage = NULL;
571 }
572}
573
574/*
575 * Destroy old address space, and allocate a new stack
576 * The new stack is only SGROWSIZ large because it is grown
577 * automatically in trap.c.
578 */
579int
29802dbb 580exec_new_vmspace(struct image_params *imgp, struct vmspace *vmcopy)
984263bc
MD
581{
582 int error;
583 struct vmspace *vmspace = imgp->proc->p_vmspace;
584 vm_offset_t stack_addr = USRSTACK - maxssiz;
29802dbb 585 vm_map_t map;
984263bc
MD
586
587 imgp->vmspace_destroyed = 1;
588
589 /*
590 * Prevent a pending AIO from modifying the new address space.
591 */
592 aio_proc_rundown(imgp->proc);
593
594 /*
595 * Blow away entire process VM, if address space not shared,
596 * otherwise, create a new VM space so that other threads are
29802dbb
MD
597 * not disrupted. If we are execing a resident vmspace we
598 * create a duplicate of it and remap the stack.
984263bc 599 */
29802dbb
MD
600 map = &vmspace->vm_map;
601 if (vmcopy) {
602 vmspace_exec(imgp->proc, vmcopy);
603 vmspace = imgp->proc->p_vmspace;
604 pmap_remove_pages(vmspace_pmap(vmspace), stack_addr, USRSTACK);
605 map = &vmspace->vm_map;
606 } else if (vmspace->vm_refcnt == 1) {
fef0fdf2 607 shmexit(vmspace);
984263bc
MD
608 pmap_remove_pages(vmspace_pmap(vmspace), 0, VM_MAXUSER_ADDRESS);
609 vm_map_remove(map, 0, VM_MAXUSER_ADDRESS);
610 } else {
29802dbb 611 vmspace_exec(imgp->proc, NULL);
984263bc
MD
612 vmspace = imgp->proc->p_vmspace;
613 map = &vmspace->vm_map;
614 }
615
616 /* Allocate a new stack */
617 error = vm_map_stack(&vmspace->vm_map, stack_addr, (vm_size_t)maxssiz,
618 VM_PROT_ALL, VM_PROT_ALL, 0);
619 if (error)
620 return (error);
621
622 /* vm_ssize and vm_maxsaddr are somewhat antiquated concepts in the
623 * VM_STACK case, but they are still used to monitor the size of the
624 * process stack so we can check the stack rlimit.
625 */
626 vmspace->vm_ssize = sgrowsiz >> PAGE_SHIFT;
627 vmspace->vm_maxsaddr = (char *)USRSTACK - maxssiz;
628
629 return(0);
630}
631
632/*
633 * Copy out argument and environment strings from the old process
634 * address space into the temporary string buffer.
635 */
636int
2bd9d75c 637exec_copyin_args(struct image_args *args, char *fname,
2abfe22f 638 enum exec_path_segflg segflg, char **argv, char **envv)
984263bc 639{
984263bc 640 char *argp, *envp;
2bd9d75c 641 int error = 0;
984263bc
MD
642 size_t length;
643
2abfe22f 644 bzero(args, sizeof(*args));
2bd9d75c
DRJ
645 args->buf = (char *) kmem_alloc_wait(exec_map, PATH_MAX + ARG_MAX);
646 if (args->buf == NULL)
647 return (ENOMEM);
648 args->begin_argv = args->buf;
649 args->endp = args->begin_argv;
650 args->space = ARG_MAX;
2bd9d75c
DRJ
651
652 args->fname = args->buf + ARG_MAX;
653
984263bc 654 /*
2bd9d75c 655 * Copy the file name.
984263bc 656 */
2bd9d75c
DRJ
657 if (segflg == PATH_SYSSPACE) {
658 error = copystr(fname, args->fname, PATH_MAX, &length);
659 } else if (segflg == PATH_USERSPACE) {
660 error = copyinstr(fname, args->fname, PATH_MAX, &length);
661 }
984263bc 662
2bd9d75c
DRJ
663 /*
664 * extract argument strings
665 */
984263bc 666
2abfe22f 667 if (argv && error == 0) {
2bd9d75c 668 /*
2abfe22f
MD
669 * The argv0 argument for execv() is allowed to be NULL,
670 * in which case we use our filename as argv[0].
671 * This guarantees that
2bd9d75c
DRJ
672 * the interpreter knows what file to open in the case
673 * that we exec an interpreted file.
674 */
2abfe22f
MD
675 argp = (caddr_t) (intptr_t) fuword(argv);
676 if (argp == NULL) {
677 length = strlen(args->fname) + 1;
678 KKASSERT(length <= args->space);
679 bcopy(args->fname, args->endp, length);
680 args->space -= length;
681 args->endp += length;
682 args->argc++;
683 argv++;
684 }
2bd9d75c
DRJ
685 while ((argp = (caddr_t) (intptr_t) fuword(argv++))) {
686 if (argp == (caddr_t) -1) {
687 error = EFAULT;
688 goto cleanup;
689 }
690 error = copyinstr(argp, args->endp,
2abfe22f 691 args->space, &length);
2bd9d75c
DRJ
692 if (error == ENAMETOOLONG)
693 error = E2BIG;
694 if (error)
695 goto cleanup;
696 args->space -= length;
697 args->endp += length;
698 args->argc++;
984263bc
MD
699 }
700 }
701
2bd9d75c 702 args->begin_envv = args->endp;
984263bc
MD
703
704 /*
705 * extract environment strings
706 */
2abfe22f 707 if (envv && error == 0) {
984263bc 708 while ((envp = (caddr_t) (intptr_t) fuword(envv++))) {
2bd9d75c
DRJ
709 if (envp == (caddr_t) -1) {
710 error = EFAULT;
711 goto cleanup;
984263bc 712 }
2bd9d75c
DRJ
713 error = copyinstr(envp, args->endp, args->space,
714 &length);
715 if (error == ENAMETOOLONG)
716 error = E2BIG;
717 if (error)
718 goto cleanup;
719 args->space -= length;
720 args->endp += length;
721 args->envc++;
984263bc
MD
722 }
723 }
724
2bd9d75c 725cleanup:
2bd9d75c
DRJ
726 return (error);
727}
728
729void
730exec_free_args(struct image_args *args)
731{
2abfe22f
MD
732 if (args->buf) {
733 kmem_free_wakeup(exec_map,
734 (vm_offset_t)args->buf, PATH_MAX + ARG_MAX);
735 args->buf = NULL;
736 }
984263bc
MD
737}
738
739/*
740 * Copy strings out to the new process address space, constructing
741 * new arg and env vector tables. Return a pointer to the base
742 * so that it can be used as the initial stack pointer.
743 */
744register_t *
2bd9d75c 745exec_copyout_strings(struct image_params *imgp)
984263bc
MD
746{
747 int argc, envc;
748 char **vectp;
749 char *stringp, *destp;
750 register_t *stack_base;
751 struct ps_strings *arginfo;
752 int szsigcode;
753
754 /*
755 * Calculate string base and vector table pointers.
756 * Also deal with signal trampoline code for this exec type.
757 */
758 arginfo = (struct ps_strings *)PS_STRINGS;
759 szsigcode = *(imgp->proc->p_sysent->sv_szsigcode);
760 destp = (caddr_t)arginfo - szsigcode - SPARE_USRSPACE -
2bd9d75c 761 roundup((ARG_MAX - imgp->args->space), sizeof(char *));
984263bc
MD
762
763 /*
764 * install sigcode
765 */
766 if (szsigcode)
767 copyout(imgp->proc->p_sysent->sv_sigcode,
2bd9d75c 768 ((caddr_t)arginfo - szsigcode), szsigcode);
984263bc
MD
769
770 /*
771 * If we have a valid auxargs ptr, prepare some room
772 * on the stack.
7ec1918b 773 *
984263bc
MD
774 * The '+ 2' is for the null pointers at the end of each of the
775 * arg and env vector sets, and 'AT_COUNT*2' is room for the
776 * ELF Auxargs data.
777 */
7ec1918b
MD
778 if (imgp->auxargs) {
779 vectp = (char **)(destp - (imgp->args->argc +
780 imgp->args->envc + 2 + AT_COUNT * 2) * sizeof(char*));
781 } else {
2bd9d75c 782 vectp = (char **)(destp - (imgp->args->argc +
7ec1918b
MD
783 imgp->args->envc + 2) * sizeof(char*));
784 }
785
984263bc 786 /*
31bc42c8
MD
787 * NOTE: don't bother aligning the stack here for GCC 2.x, it will
788 * be done in crt1.o. Note that GCC 3.x aligns the stack in main.
984263bc 789 */
984263bc
MD
790
791 /*
792 * vectp also becomes our initial stack base
793 */
794 stack_base = (register_t *)vectp;
795
2bd9d75c
DRJ
796 stringp = imgp->args->begin_argv;
797 argc = imgp->args->argc;
798 envc = imgp->args->envc;
984263bc
MD
799
800 /*
801 * Copy out strings - arguments and environment.
802 */
2bd9d75c 803 copyout(stringp, destp, ARG_MAX - imgp->args->space);
984263bc
MD
804
805 /*
806 * Fill in "ps_strings" struct for ps, w, etc.
807 */
808 suword(&arginfo->ps_argvstr, (long)(intptr_t)vectp);
809 suword(&arginfo->ps_nargvstr, argc);
810
811 /*
812 * Fill in argument portion of vector table.
813 */
814 for (; argc > 0; --argc) {
815 suword(vectp++, (long)(intptr_t)destp);
816 while (*stringp++ != 0)
817 destp++;
818 destp++;
819 }
820
7a44d1cb 821 /* a null vector table pointer separates the argp's from the envp's */
984263bc
MD
822 suword(vectp++, 0);
823
824 suword(&arginfo->ps_envstr, (long)(intptr_t)vectp);
825 suword(&arginfo->ps_nenvstr, envc);
826
827 /*
828 * Fill in environment portion of vector table.
829 */
830 for (; envc > 0; --envc) {
831 suword(vectp++, (long)(intptr_t)destp);
832 while (*stringp++ != 0)
833 destp++;
834 destp++;
835 }
836
837 /* end of vector table is a null pointer */
838 suword(vectp, 0);
839
840 return (stack_base);
841}
842
843/*
844 * Check permissions of file to execute.
845 * Return 0 for success or error code on failure.
846 */
847int
848exec_check_permissions(imgp)
849 struct image_params *imgp;
850{
851 struct proc *p = imgp->proc;
852 struct vnode *vp = imgp->vp;
853 struct vattr *attr = imgp->attr;
dadab5e9 854 struct thread *td = p->p_thread;
984263bc
MD
855 int error;
856
857 /* Get file attributes */
3b568787 858 error = VOP_GETATTR(vp, attr, td);
984263bc
MD
859 if (error)
860 return (error);
861
862 /*
863 * 1) Check if file execution is disabled for the filesystem that this
864 * file resides on.
865 * 2) Insure that at least one execute bit is on - otherwise root
866 * will always succeed, and we don't want to happen unless the
867 * file really is executable.
868 * 3) Insure that the file is a regular file.
869 */
870 if ((vp->v_mount->mnt_flag & MNT_NOEXEC) ||
871 ((attr->va_mode & 0111) == 0) ||
872 (attr->va_type != VREG)) {
873 return (EACCES);
874 }
875
876 /*
877 * Zero length files can't be exec'd
878 */
879 if (attr->va_size == 0)
880 return (ENOEXEC);
881
882 /*
883 * Check for execute permission to file based on current credentials.
884 */
dadab5e9 885 error = VOP_ACCESS(vp, VEXEC, p->p_ucred, td);
984263bc
MD
886 if (error)
887 return (error);
888
889 /*
890 * Check number of open-for-writes on the file and deny execution
891 * if there are any.
892 */
893 if (vp->v_writecount)
894 return (ETXTBSY);
895
896 /*
897 * Call filesystem specific open routine (which does nothing in the
898 * general case).
899 */
dadab5e9 900 error = VOP_OPEN(vp, FREAD, p->p_ucred, td);
984263bc
MD
901 if (error)
902 return (error);
903
904 return (0);
905}
906
907/*
908 * Exec handler registration
909 */
910int
911exec_register(execsw_arg)
912 const struct execsw *execsw_arg;
913{
914 const struct execsw **es, **xs, **newexecsw;
915 int count = 2; /* New slot and trailing NULL */
916
917 if (execsw)
918 for (es = execsw; *es; es++)
919 count++;
920 newexecsw = malloc(count * sizeof(*es), M_TEMP, M_WAITOK);
921 if (newexecsw == NULL)
922 return ENOMEM;
923 xs = newexecsw;
924 if (execsw)
925 for (es = execsw; *es; es++)
926 *xs++ = *es;
927 *xs++ = execsw_arg;
928 *xs = NULL;
929 if (execsw)
930 free(execsw, M_TEMP);
931 execsw = newexecsw;
932 return 0;
933}
934
935int
936exec_unregister(execsw_arg)
937 const struct execsw *execsw_arg;
938{
939 const struct execsw **es, **xs, **newexecsw;
940 int count = 1;
941
942 if (execsw == NULL)
943 panic("unregister with no handlers left?\n");
944
945 for (es = execsw; *es; es++) {
946 if (*es == execsw_arg)
947 break;
948 }
949 if (*es == NULL)
950 return ENOENT;
951 for (es = execsw; *es; es++)
952 if (*es != execsw_arg)
953 count++;
954 newexecsw = malloc(count * sizeof(*es), M_TEMP, M_WAITOK);
955 if (newexecsw == NULL)
956 return ENOMEM;
957 xs = newexecsw;
958 for (es = execsw; *es; es++)
959 if (*es != execsw_arg)
960 *xs++ = *es;
961 *xs = NULL;
962 if (execsw)
963 free(execsw, M_TEMP);
964 execsw = newexecsw;
965 return 0;
966}