Last commit was completely wrong. Reverting to old revision of file.
[dragonfly.git] / sys / kern / kern_exec.c
CommitLineData
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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 $
7a44d1cb 27 * $DragonFly: src/sys/kern/kern_exec.c,v 1.18 2004/01/08 18:39:18 asmodai Exp $
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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>
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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 *);
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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
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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
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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{
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118 struct thread *td = curthread;
119 struct proc *p = td->td_proc;
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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
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DRJ
126 if (debug_execve_args) {
127 printf("%s()\n", __func__);
128 print_execve_args(args);
129 }
130
dadab5e9 131 KKASSERT(p);
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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;
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149 imgp->entry_addr = 0;
150 imgp->vmspace_destroyed = 0;
151 imgp->interpreted = 0;
2abfe22f 152 imgp->interpreter_name[0] = 0;
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153 imgp->auxargs = NULL;
154 imgp->vp = NULL;
155 imgp->firstpage = NULL;
156 imgp->ps_strings = 0;
157
158 /*
159 * Allocate temporary demand zeroed space for argument and
160 * environment strings
161 */
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DRJ
162 imgp->image_header = (char *)kmem_alloc_wait(exec_map, PAGE_SIZE);
163 if (imgp->image_header == NULL) {
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164 error = ENOMEM;
165 goto exec_fail;
166 }
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167
168interpret:
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169
170 /*
171 * Translate the file name. namei() returns a vnode pointer
172 * in ni_vp amoung other things.
173 */
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174 error = namei(ndp);
175 if (error) {
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DRJ
176 kmem_free_wakeup(exec_map, (vm_offset_t)imgp->image_header,
177 PAGE_SIZE);
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178 goto exec_fail;
179 }
180
181 imgp->vp = ndp->ni_vp;
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182
183 /*
184 * Check file permissions (also 'opens' file)
185 */
186 error = exec_check_permissions(imgp);
187 if (error) {
dadab5e9 188 VOP_UNLOCK(imgp->vp, 0, td);
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189 goto exec_fail_dealloc;
190 }
191
192 error = exec_map_first_page(imgp);
dadab5e9 193 VOP_UNLOCK(imgp->vp, 0, td);
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194 if (error)
195 goto exec_fail_dealloc;
196
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DRJ
197 if (debug_execve_args && imgp->interpreted) {
198 printf(" target is interpreted -- recursive pass\n");
199 printf(" interpreter: %s\n", imgp->interpreter_name);
200 print_execve_args(args);
201 }
202
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203 /*
204 * If the current process has a special image activator it
205 * wants to try first, call it. For example, emulating shell
206 * scripts differently.
207 */
208 error = -1;
209 if ((img_first = imgp->proc->p_sysent->sv_imgact_try) != NULL)
210 error = img_first(imgp);
211
212 /*
213 * Loop through the list of image activators, calling each one.
214 * An activator returns -1 if there is no match, 0 on success,
215 * and an error otherwise.
216 */
217 for (i = 0; error == -1 && execsw[i]; ++i) {
218 if (execsw[i]->ex_imgact == NULL ||
219 execsw[i]->ex_imgact == img_first) {
220 continue;
221 }
222 error = (*execsw[i]->ex_imgact)(imgp);
223 }
224
225 if (error) {
226 if (error == -1)
227 error = ENOEXEC;
228 goto exec_fail_dealloc;
229 }
230
231 /*
232 * Special interpreter operation, cleanup and loop up to try to
233 * activate the interpreter.
234 */
235 if (imgp->interpreted) {
236 exec_unmap_first_page(imgp);
237 /* free name buffer and old vnode */
238 NDFREE(ndp, NDF_ONLY_PNBUF);
239 vrele(ndp->ni_vp);
240 /* set new name to that of the interpreter */
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241 NDINIT(ndp, NAMEI_LOOKUP,
242 CNP_LOCKLEAF | CNP_FOLLOW | CNP_SAVENAME,
dadab5e9 243 UIO_SYSSPACE, imgp->interpreter_name, td);
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244 goto interpret;
245 }
246
247 /*
248 * Copy out strings (args and env) and initialize stack base
249 */
250 stack_base = exec_copyout_strings(imgp);
251 p->p_vmspace->vm_minsaddr = (char *)stack_base;
252
253 /*
254 * If custom stack fixup routine present for this process
255 * let it do the stack setup.
256 * Else stuff argument count as first item on stack
257 */
258 if (p->p_sysent->sv_fixup)
259 (*p->p_sysent->sv_fixup)(&stack_base, imgp);
260 else
2bd9d75c 261 suword(--stack_base, imgp->args->argc);
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262
263 /*
264 * For security and other reasons, the file descriptor table cannot
265 * be shared after an exec.
266 */
267 if (p->p_fd->fd_refcnt > 1) {
268 struct filedesc *tmp;
269
270 tmp = fdcopy(p);
271 fdfree(p);
272 p->p_fd = tmp;
273 }
274
275 /*
276 * For security and other reasons, signal handlers cannot
277 * be shared after an exec. The new proces gets a copy of the old
278 * handlers. In execsigs(), the new process will have its signals
279 * reset.
280 */
281 if (p->p_procsig->ps_refcnt > 1) {
282 struct procsig *newprocsig;
283
284 MALLOC(newprocsig, struct procsig *, sizeof(struct procsig),
285 M_SUBPROC, M_WAITOK);
286 bcopy(p->p_procsig, newprocsig, sizeof(*newprocsig));
287 p->p_procsig->ps_refcnt--;
288 p->p_procsig = newprocsig;
289 p->p_procsig->ps_refcnt = 1;
290 if (p->p_sigacts == &p->p_addr->u_sigacts)
291 panic("shared procsig but private sigacts?");
292
293 p->p_addr->u_sigacts = *p->p_sigacts;
294 p->p_sigacts = &p->p_addr->u_sigacts;
295 }
296
297 /* Stop profiling */
298 stopprofclock(p);
299
300 /* close files on exec */
301 fdcloseexec(p);
302
303 /* reset caught signals */
304 execsigs(p);
305
306 /* name this process - nameiexec(p, ndp) */
307 len = min(ndp->ni_cnd.cn_namelen,MAXCOMLEN);
308 bcopy(ndp->ni_cnd.cn_nameptr, p->p_comm, len);
309 p->p_comm[len] = 0;
310
311 /*
312 * mark as execed, wakeup the process that vforked (if any) and tell
313 * it that it now has its own resources back
314 */
315 p->p_flag |= P_EXEC;
316 if (p->p_pptr && (p->p_flag & P_PPWAIT)) {
317 p->p_flag &= ~P_PPWAIT;
318 wakeup((caddr_t)p->p_pptr);
319 }
320
321 /*
322 * Implement image setuid/setgid.
323 *
324 * Don't honor setuid/setgid if the filesystem prohibits it or if
325 * the process is being traced.
326 */
327 if ((((attr.va_mode & VSUID) && p->p_ucred->cr_uid != attr.va_uid) ||
328 ((attr.va_mode & VSGID) && p->p_ucred->cr_gid != attr.va_gid)) &&
329 (imgp->vp->v_mount->mnt_flag & MNT_NOSUID) == 0 &&
330 (p->p_flag & P_TRACED) == 0) {
331 /*
332 * Turn off syscall tracing for set-id programs, except for
333 * root. Record any set-id flags first to make sure that
334 * we do not regain any tracing during a possible block.
335 */
41c20dac 336 setsugid();
dadab5e9 337 if (p->p_tracep && suser(td)) {
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338 struct vnode *vtmp;
339
340 if ((vtmp = p->p_tracep) != NULL) {
341 p->p_tracep = NULL;
342 p->p_traceflag = 0;
343 vrele(vtmp);
344 }
345 }
346 /* Close any file descriptors 0..2 that reference procfs */
347 setugidsafety(p);
348 /* Make sure file descriptors 0..2 are in use. */
349 error = fdcheckstd(p);
350 if (error != 0)
351 goto exec_fail_dealloc;
352 /*
353 * Set the new credentials.
354 */
e9a372eb 355 cratom(&p->p_ucred);
984263bc 356 if (attr.va_mode & VSUID)
41c20dac 357 change_euid(attr.va_uid);
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358 if (attr.va_mode & VSGID)
359 p->p_ucred->cr_gid = attr.va_gid;
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360
361 /*
362 * Clear local varsym variables
363 */
364 varsymset_clean(&p->p_varsymset);
984263bc 365 } else {
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MD
366 if (p->p_ucred->cr_uid == p->p_ucred->cr_ruid &&
367 p->p_ucred->cr_gid == p->p_ucred->cr_rgid)
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368 p->p_flag &= ~P_SUGID;
369 }
370
371 /*
372 * Implement correct POSIX saved-id behavior.
373 */
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374 if (p->p_ucred->cr_svuid != p->p_ucred->cr_uid ||
375 p->p_ucred->cr_svgid != p->p_ucred->cr_gid) {
376 cratom(&p->p_ucred);
377 p->p_ucred->cr_svuid = p->p_ucred->cr_uid;
378 p->p_ucred->cr_svgid = p->p_ucred->cr_gid;
379 }
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380
381 /*
382 * Store the vp for use in procfs
383 */
384 if (p->p_textvp) /* release old reference */
385 vrele(p->p_textvp);
386 VREF(ndp->ni_vp);
387 p->p_textvp = ndp->ni_vp;
388
389 /*
390 * Notify others that we exec'd, and clear the P_INEXEC flag
391 * as we're now a bona fide freshly-execed process.
392 */
393 KNOTE(&p->p_klist, NOTE_EXEC);
394 p->p_flag &= ~P_INEXEC;
395
396 /*
397 * If tracing the process, trap to debugger so breakpoints
398 * can be set before the program executes.
399 */
400 STOPEVENT(p, S_EXEC, 0);
401
402 if (p->p_flag & P_TRACED)
403 psignal(p, SIGTRAP);
404
405 /* clear "fork but no exec" flag, as we _are_ execing */
406 p->p_acflag &= ~AFORK;
407
408 /* Set values passed into the program in registers. */
409 setregs(p, imgp->entry_addr, (u_long)(uintptr_t)stack_base,
410 imgp->ps_strings);
411
412 /* Free any previous argument cache */
413 if (p->p_args && --p->p_args->ar_ref == 0)
414 FREE(p->p_args, M_PARGS);
415 p->p_args = NULL;
416
417 /* Cache arguments if they fit inside our allowance */
2bd9d75c 418 i = imgp->args->begin_envv - imgp->args->begin_argv;
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MD
419 if (ps_arg_cache_limit >= i + sizeof(struct pargs)) {
420 MALLOC(p->p_args, struct pargs *, sizeof(struct pargs) + i,
421 M_PARGS, M_WAITOK);
422 p->p_args->ar_ref = 1;
423 p->p_args->ar_length = i;
2bd9d75c 424 bcopy(imgp->args->begin_argv, p->p_args->ar_args, i);
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MD
425 }
426
427exec_fail_dealloc:
428
429 /*
430 * free various allocated resources
431 */
432 if (imgp->firstpage)
433 exec_unmap_first_page(imgp);
434
2bd9d75c
DRJ
435 if (imgp->image_header != NULL)
436 kmem_free_wakeup(exec_map, (vm_offset_t)imgp->image_header,
437 PAGE_SIZE);
984263bc
MD
438
439 if (imgp->vp) {
440 NDFREE(ndp, NDF_ONLY_PNBUF);
441 vrele(imgp->vp);
442 }
443
444 if (error == 0)
445 return (0);
446
447exec_fail:
448 /* we're done here, clear P_INEXEC */
449 p->p_flag &= ~P_INEXEC;
450 if (imgp->vmspace_destroyed) {
451 /* sorry, no more process anymore. exit gracefully */
41c20dac 452 exit1(W_EXITCODE(0, SIGABRT));
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453 /* NOT REACHED */
454 return(0);
455 } else {
456 return(error);
457 }
458}
459
2bd9d75c
DRJ
460/*
461 * execve() system call.
462 */
463int
464execve(struct execve_args *uap)
465{
466 struct thread *td = curthread;
467 struct nameidata nd;
468 struct image_args args;
469 int error;
470
471 NDINIT(&nd, NAMEI_LOOKUP, CNP_LOCKLEAF | CNP_FOLLOW | CNP_SAVENAME,
472 UIO_USERSPACE, uap->fname, td);
473
474 error = exec_copyin_args(&args, uap->fname, PATH_USERSPACE,
2abfe22f
MD
475 uap->argv, uap->envv);
476 if (error == 0)
477 error = kern_execve(&nd, &args);
2bd9d75c
DRJ
478
479 exec_free_args(&args);
480
481 /*
482 * The syscall result is returned in registers to the new program.
483 * Linux will register %edx as an atexit function and we must be
484 * sure to set it to 0. XXX
485 */
486 if (error == 0)
487 uap->sysmsg_result64 = 0;
488
489 return (error);
490}
491
984263bc 492int
41c20dac 493exec_map_first_page(struct image_params *imgp)
984263bc
MD
494{
495 int s, rv, i;
496 int initial_pagein;
497 vm_page_t ma[VM_INITIAL_PAGEIN];
498 vm_object_t object;
499
500
501 if (imgp->firstpage) {
502 exec_unmap_first_page(imgp);
503 }
504
505 VOP_GETVOBJECT(imgp->vp, &object);
506 s = splvm();
507
508 ma[0] = vm_page_grab(object, 0, VM_ALLOC_NORMAL | VM_ALLOC_RETRY);
509
510 if ((ma[0]->valid & VM_PAGE_BITS_ALL) != VM_PAGE_BITS_ALL) {
511 initial_pagein = VM_INITIAL_PAGEIN;
512 if (initial_pagein > object->size)
513 initial_pagein = object->size;
514 for (i = 1; i < initial_pagein; i++) {
515 if ((ma[i] = vm_page_lookup(object, i)) != NULL) {
516 if ((ma[i]->flags & PG_BUSY) || ma[i]->busy)
517 break;
518 if (ma[i]->valid)
519 break;
520 vm_page_busy(ma[i]);
521 } else {
522 ma[i] = vm_page_alloc(object, i, VM_ALLOC_NORMAL);
523 if (ma[i] == NULL)
524 break;
525 }
526 }
527 initial_pagein = i;
528
529 rv = vm_pager_get_pages(object, ma, initial_pagein, 0);
530 ma[0] = vm_page_lookup(object, 0);
531
532 if ((rv != VM_PAGER_OK) || (ma[0] == NULL) || (ma[0]->valid == 0)) {
533 if (ma[0]) {
534 vm_page_protect(ma[0], VM_PROT_NONE);
535 vm_page_free(ma[0]);
536 }
537 splx(s);
538 return EIO;
539 }
540 }
541
542 vm_page_wire(ma[0]);
543 vm_page_wakeup(ma[0]);
544 splx(s);
545
546 pmap_kenter((vm_offset_t) imgp->image_header, VM_PAGE_TO_PHYS(ma[0]));
547 imgp->firstpage = ma[0];
548
549 return 0;
550}
551
552void
553exec_unmap_first_page(imgp)
554 struct image_params *imgp;
555{
556 if (imgp->firstpage) {
557 pmap_kremove((vm_offset_t) imgp->image_header);
558 vm_page_unwire(imgp->firstpage, 1);
559 imgp->firstpage = NULL;
560 }
561}
562
563/*
564 * Destroy old address space, and allocate a new stack
565 * The new stack is only SGROWSIZ large because it is grown
566 * automatically in trap.c.
567 */
568int
569exec_new_vmspace(imgp)
570 struct image_params *imgp;
571{
572 int error;
573 struct vmspace *vmspace = imgp->proc->p_vmspace;
574 vm_offset_t stack_addr = USRSTACK - maxssiz;
575 vm_map_t map = &vmspace->vm_map;
576
577 imgp->vmspace_destroyed = 1;
578
579 /*
580 * Prevent a pending AIO from modifying the new address space.
581 */
582 aio_proc_rundown(imgp->proc);
583
584 /*
585 * Blow away entire process VM, if address space not shared,
586 * otherwise, create a new VM space so that other threads are
587 * not disrupted
588 */
589 if (vmspace->vm_refcnt == 1) {
fef0fdf2 590 shmexit(vmspace);
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591 pmap_remove_pages(vmspace_pmap(vmspace), 0, VM_MAXUSER_ADDRESS);
592 vm_map_remove(map, 0, VM_MAXUSER_ADDRESS);
593 } else {
594 vmspace_exec(imgp->proc);
595 vmspace = imgp->proc->p_vmspace;
596 map = &vmspace->vm_map;
597 }
598
599 /* Allocate a new stack */
600 error = vm_map_stack(&vmspace->vm_map, stack_addr, (vm_size_t)maxssiz,
601 VM_PROT_ALL, VM_PROT_ALL, 0);
602 if (error)
603 return (error);
604
605 /* vm_ssize and vm_maxsaddr are somewhat antiquated concepts in the
606 * VM_STACK case, but they are still used to monitor the size of the
607 * process stack so we can check the stack rlimit.
608 */
609 vmspace->vm_ssize = sgrowsiz >> PAGE_SHIFT;
610 vmspace->vm_maxsaddr = (char *)USRSTACK - maxssiz;
611
612 return(0);
613}
614
615/*
616 * Copy out argument and environment strings from the old process
617 * address space into the temporary string buffer.
618 */
619int
2bd9d75c 620exec_copyin_args(struct image_args *args, char *fname,
2abfe22f 621 enum exec_path_segflg segflg, char **argv, char **envv)
984263bc 622{
984263bc 623 char *argp, *envp;
2bd9d75c 624 int error = 0;
984263bc
MD
625 size_t length;
626
2abfe22f 627 bzero(args, sizeof(*args));
2bd9d75c
DRJ
628 args->buf = (char *) kmem_alloc_wait(exec_map, PATH_MAX + ARG_MAX);
629 if (args->buf == NULL)
630 return (ENOMEM);
631 args->begin_argv = args->buf;
632 args->endp = args->begin_argv;
633 args->space = ARG_MAX;
2bd9d75c
DRJ
634
635 args->fname = args->buf + ARG_MAX;
636
984263bc 637 /*
2bd9d75c 638 * Copy the file name.
984263bc 639 */
2bd9d75c
DRJ
640 if (segflg == PATH_SYSSPACE) {
641 error = copystr(fname, args->fname, PATH_MAX, &length);
642 } else if (segflg == PATH_USERSPACE) {
643 error = copyinstr(fname, args->fname, PATH_MAX, &length);
644 }
984263bc 645
2bd9d75c
DRJ
646 /*
647 * extract argument strings
648 */
984263bc 649
2abfe22f 650 if (argv && error == 0) {
2bd9d75c 651 /*
2abfe22f
MD
652 * The argv0 argument for execv() is allowed to be NULL,
653 * in which case we use our filename as argv[0].
654 * This guarantees that
2bd9d75c
DRJ
655 * the interpreter knows what file to open in the case
656 * that we exec an interpreted file.
657 */
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658 argp = (caddr_t) (intptr_t) fuword(argv);
659 if (argp == NULL) {
660 length = strlen(args->fname) + 1;
661 KKASSERT(length <= args->space);
662 bcopy(args->fname, args->endp, length);
663 args->space -= length;
664 args->endp += length;
665 args->argc++;
666 argv++;
667 }
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DRJ
668 while ((argp = (caddr_t) (intptr_t) fuword(argv++))) {
669 if (argp == (caddr_t) -1) {
670 error = EFAULT;
671 goto cleanup;
672 }
673 error = copyinstr(argp, args->endp,
2abfe22f 674 args->space, &length);
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DRJ
675 if (error == ENAMETOOLONG)
676 error = E2BIG;
677 if (error)
678 goto cleanup;
679 args->space -= length;
680 args->endp += length;
681 args->argc++;
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MD
682 }
683 }
684
2bd9d75c 685 args->begin_envv = args->endp;
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686
687 /*
688 * extract environment strings
689 */
2abfe22f 690 if (envv && error == 0) {
984263bc 691 while ((envp = (caddr_t) (intptr_t) fuword(envv++))) {
2bd9d75c
DRJ
692 if (envp == (caddr_t) -1) {
693 error = EFAULT;
694 goto cleanup;
984263bc 695 }
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DRJ
696 error = copyinstr(envp, args->endp, args->space,
697 &length);
698 if (error == ENAMETOOLONG)
699 error = E2BIG;
700 if (error)
701 goto cleanup;
702 args->space -= length;
703 args->endp += length;
704 args->envc++;
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MD
705 }
706 }
707
2bd9d75c 708cleanup:
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DRJ
709 return (error);
710}
711
712void
713exec_free_args(struct image_args *args)
714{
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MD
715 if (args->buf) {
716 kmem_free_wakeup(exec_map,
717 (vm_offset_t)args->buf, PATH_MAX + ARG_MAX);
718 args->buf = NULL;
719 }
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MD
720}
721
722/*
723 * Copy strings out to the new process address space, constructing
724 * new arg and env vector tables. Return a pointer to the base
725 * so that it can be used as the initial stack pointer.
726 */
727register_t *
2bd9d75c 728exec_copyout_strings(struct image_params *imgp)
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MD
729{
730 int argc, envc;
731 char **vectp;
732 char *stringp, *destp;
733 register_t *stack_base;
734 struct ps_strings *arginfo;
735 int szsigcode;
736
737 /*
738 * Calculate string base and vector table pointers.
739 * Also deal with signal trampoline code for this exec type.
740 */
741 arginfo = (struct ps_strings *)PS_STRINGS;
742 szsigcode = *(imgp->proc->p_sysent->sv_szsigcode);
743 destp = (caddr_t)arginfo - szsigcode - SPARE_USRSPACE -
2bd9d75c 744 roundup((ARG_MAX - imgp->args->space), sizeof(char *));
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MD
745
746 /*
747 * install sigcode
748 */
749 if (szsigcode)
750 copyout(imgp->proc->p_sysent->sv_sigcode,
2bd9d75c 751 ((caddr_t)arginfo - szsigcode), szsigcode);
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MD
752
753 /*
754 * If we have a valid auxargs ptr, prepare some room
755 * on the stack.
7ec1918b 756 *
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MD
757 * The '+ 2' is for the null pointers at the end of each of the
758 * arg and env vector sets, and 'AT_COUNT*2' is room for the
759 * ELF Auxargs data.
760 */
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MD
761 if (imgp->auxargs) {
762 vectp = (char **)(destp - (imgp->args->argc +
763 imgp->args->envc + 2 + AT_COUNT * 2) * sizeof(char*));
764 } else {
2bd9d75c 765 vectp = (char **)(destp - (imgp->args->argc +
7ec1918b
MD
766 imgp->args->envc + 2) * sizeof(char*));
767 }
768
984263bc 769 /*
31bc42c8
MD
770 * NOTE: don't bother aligning the stack here for GCC 2.x, it will
771 * be done in crt1.o. Note that GCC 3.x aligns the stack in main.
984263bc 772 */
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MD
773
774 /*
775 * vectp also becomes our initial stack base
776 */
777 stack_base = (register_t *)vectp;
778
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DRJ
779 stringp = imgp->args->begin_argv;
780 argc = imgp->args->argc;
781 envc = imgp->args->envc;
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MD
782
783 /*
784 * Copy out strings - arguments and environment.
785 */
2bd9d75c 786 copyout(stringp, destp, ARG_MAX - imgp->args->space);
984263bc
MD
787
788 /*
789 * Fill in "ps_strings" struct for ps, w, etc.
790 */
791 suword(&arginfo->ps_argvstr, (long)(intptr_t)vectp);
792 suword(&arginfo->ps_nargvstr, argc);
793
794 /*
795 * Fill in argument portion of vector table.
796 */
797 for (; argc > 0; --argc) {
798 suword(vectp++, (long)(intptr_t)destp);
799 while (*stringp++ != 0)
800 destp++;
801 destp++;
802 }
803
7a44d1cb 804 /* a null vector table pointer separates the argp's from the envp's */
984263bc
MD
805 suword(vectp++, 0);
806
807 suword(&arginfo->ps_envstr, (long)(intptr_t)vectp);
808 suword(&arginfo->ps_nenvstr, envc);
809
810 /*
811 * Fill in environment portion of vector table.
812 */
813 for (; envc > 0; --envc) {
814 suword(vectp++, (long)(intptr_t)destp);
815 while (*stringp++ != 0)
816 destp++;
817 destp++;
818 }
819
820 /* end of vector table is a null pointer */
821 suword(vectp, 0);
822
823 return (stack_base);
824}
825
826/*
827 * Check permissions of file to execute.
828 * Return 0 for success or error code on failure.
829 */
830int
831exec_check_permissions(imgp)
832 struct image_params *imgp;
833{
834 struct proc *p = imgp->proc;
835 struct vnode *vp = imgp->vp;
836 struct vattr *attr = imgp->attr;
dadab5e9 837 struct thread *td = p->p_thread;
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MD
838 int error;
839
840 /* Get file attributes */
3b568787 841 error = VOP_GETATTR(vp, attr, td);
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MD
842 if (error)
843 return (error);
844
845 /*
846 * 1) Check if file execution is disabled for the filesystem that this
847 * file resides on.
848 * 2) Insure that at least one execute bit is on - otherwise root
849 * will always succeed, and we don't want to happen unless the
850 * file really is executable.
851 * 3) Insure that the file is a regular file.
852 */
853 if ((vp->v_mount->mnt_flag & MNT_NOEXEC) ||
854 ((attr->va_mode & 0111) == 0) ||
855 (attr->va_type != VREG)) {
856 return (EACCES);
857 }
858
859 /*
860 * Zero length files can't be exec'd
861 */
862 if (attr->va_size == 0)
863 return (ENOEXEC);
864
865 /*
866 * Check for execute permission to file based on current credentials.
867 */
dadab5e9 868 error = VOP_ACCESS(vp, VEXEC, p->p_ucred, td);
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MD
869 if (error)
870 return (error);
871
872 /*
873 * Check number of open-for-writes on the file and deny execution
874 * if there are any.
875 */
876 if (vp->v_writecount)
877 return (ETXTBSY);
878
879 /*
880 * Call filesystem specific open routine (which does nothing in the
881 * general case).
882 */
dadab5e9 883 error = VOP_OPEN(vp, FREAD, p->p_ucred, td);
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MD
884 if (error)
885 return (error);
886
887 return (0);
888}
889
890/*
891 * Exec handler registration
892 */
893int
894exec_register(execsw_arg)
895 const struct execsw *execsw_arg;
896{
897 const struct execsw **es, **xs, **newexecsw;
898 int count = 2; /* New slot and trailing NULL */
899
900 if (execsw)
901 for (es = execsw; *es; es++)
902 count++;
903 newexecsw = malloc(count * sizeof(*es), M_TEMP, M_WAITOK);
904 if (newexecsw == NULL)
905 return ENOMEM;
906 xs = newexecsw;
907 if (execsw)
908 for (es = execsw; *es; es++)
909 *xs++ = *es;
910 *xs++ = execsw_arg;
911 *xs = NULL;
912 if (execsw)
913 free(execsw, M_TEMP);
914 execsw = newexecsw;
915 return 0;
916}
917
918int
919exec_unregister(execsw_arg)
920 const struct execsw *execsw_arg;
921{
922 const struct execsw **es, **xs, **newexecsw;
923 int count = 1;
924
925 if (execsw == NULL)
926 panic("unregister with no handlers left?\n");
927
928 for (es = execsw; *es; es++) {
929 if (*es == execsw_arg)
930 break;
931 }
932 if (*es == NULL)
933 return ENOENT;
934 for (es = execsw; *es; es++)
935 if (*es != execsw_arg)
936 count++;
937 newexecsw = malloc(count * sizeof(*es), M_TEMP, M_WAITOK);
938 if (newexecsw == NULL)
939 return ENOMEM;
940 xs = newexecsw;
941 for (es = execsw; *es; es++)
942 if (*es != execsw_arg)
943 *xs++ = *es;
944 *xs = NULL;
945 if (execsw)
946 free(execsw, M_TEMP);
947 execsw = newexecsw;
948 return 0;
949}