Use localhost instead of 127.0.0.1, since IPv6 should work as well.
[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 $
87de5057 27 * $DragonFly: src/sys/kern/kern_exec.c,v 1.38 2006/05/06 02:43:12 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>
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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>
fad57d0e 47#include <sys/nlookup.h>
18f40545 48#include <sys/sfbuf.h>
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49#include <sys/sysent.h>
50#include <sys/shm.h>
51#include <sys/sysctl.h>
52#include <sys/vnode.h>
a6f89c72 53#include <sys/vmmeter.h>
984263bc 54#include <sys/aio.h>
17a7ca1f 55#include <sys/libkern.h>
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56
57#include <vm/vm.h>
58#include <vm/vm_param.h>
59#include <sys/lock.h>
60#include <vm/pmap.h>
61#include <vm/vm_page.h>
62#include <vm/vm_map.h>
63#include <vm/vm_kern.h>
64#include <vm/vm_extern.h>
65#include <vm/vm_object.h>
66#include <vm/vm_pager.h>
67
68#include <sys/user.h>
69#include <machine/reg.h>
70
5fd012e0
MD
71#include <sys/thread2.h>
72
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73MALLOC_DEFINE(M_PARGS, "proc-args", "Process arguments");
74
402ed7e1 75static register_t *exec_copyout_strings (struct image_params *);
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76
77/* XXX This should be vm_size_t. */
78static u_long ps_strings = PS_STRINGS;
79SYSCTL_ULONG(_kern, KERN_PS_STRINGS, ps_strings, CTLFLAG_RD, &ps_strings, 0, "");
80
81/* XXX This should be vm_size_t. */
82static u_long usrstack = USRSTACK;
83SYSCTL_ULONG(_kern, KERN_USRSTACK, usrstack, CTLFLAG_RD, &usrstack, 0, "");
84
85u_long ps_arg_cache_limit = PAGE_SIZE / 16;
86SYSCTL_LONG(_kern, OID_AUTO, ps_arg_cache_limit, CTLFLAG_RW,
87 &ps_arg_cache_limit, 0, "");
88
89int ps_argsopen = 1;
90SYSCTL_INT(_kern, OID_AUTO, ps_argsopen, CTLFLAG_RW, &ps_argsopen, 0, "");
91
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92void print_execve_args(struct image_args *args);
93int debug_execve_args = 0;
94SYSCTL_INT(_kern, OID_AUTO, debug_execve_args, CTLFLAG_RW, &debug_execve_args,
95 0, "");
96
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MD
97/*
98 * stackgap_random specifies if the stackgap should have a random size added
99 * to it. It must be a power of 2. If non-zero, the stack gap will be
100 * calculated as: ALIGN(arc4random() & (stackgap_random - 1)).
101 */
102static int stackgap_random = 1024;
103static int
104sysctl_kern_stackgap(SYSCTL_HANDLER_ARGS)
105{
106 int error, new_val;
107 new_val = stackgap_random;
108 error = sysctl_handle_int(oidp, &new_val, 0, req);
109 if (error != 0 || req->newptr == NULL)
110 return (error);
111 if ((new_val < 0) || (new_val > 16 * PAGE_SIZE) || ! powerof2(new_val))
112 return (EINVAL);
113 stackgap_random = new_val;
114
115 return(0);
116}
117
118SYSCTL_PROC(_kern, OID_AUTO, stackgap_random, CTLFLAG_RW|CTLTYPE_UINT,
119 0, 0, sysctl_kern_stackgap, "IU", "Max random stack gap (power of 2)");
120
2bd9d75c
DRJ
121void
122print_execve_args(struct image_args *args)
123{
124 char *cp;
125 int ndx;
126
127 cp = args->begin_argv;
128 for (ndx = 0; ndx < args->argc; ndx++) {
129 printf("\targv[%d]: %s\n", ndx, cp);
130 while (*cp++ != '\0');
131 }
132 for (ndx = 0; ndx < args->envc; ndx++) {
133 printf("\tenvv[%d]: %s\n", ndx, cp);
134 while (*cp++ != '\0');
135 }
136}
137
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138/*
139 * Each of the items is a pointer to a `const struct execsw', hence the
140 * double pointer here.
141 */
142static const struct execsw **execsw;
143
984263bc 144int
fad57d0e 145kern_execve(struct nlookupdata *nd, struct image_args *args)
984263bc 146{
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147 struct thread *td = curthread;
148 struct proc *p = td->td_proc;
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149 register_t *stack_base;
150 int error, len, i;
151 struct image_params image_params, *imgp;
152 struct vattr attr;
402ed7e1 153 int (*img_first) (struct image_params *);
984263bc 154
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DRJ
155 if (debug_execve_args) {
156 printf("%s()\n", __func__);
157 print_execve_args(args);
158 }
159
dadab5e9 160 KKASSERT(p);
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161 imgp = &image_params;
162
163 /*
164 * Lock the process and set the P_INEXEC flag to indicate that
165 * it should be left alone until we're done here. This is
166 * necessary to avoid race conditions - e.g. in ptrace() -
167 * that might allow a local user to illicitly obtain elevated
168 * privileges.
169 */
170 p->p_flag |= P_INEXEC;
171
172 /*
173 * Initialize part of the common data
174 */
175 imgp->proc = p;
2bd9d75c 176 imgp->args = args;
984263bc 177 imgp->attr = &attr;
984263bc 178 imgp->entry_addr = 0;
29802dbb 179 imgp->resident = 0;
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180 imgp->vmspace_destroyed = 0;
181 imgp->interpreted = 0;
2abfe22f 182 imgp->interpreter_name[0] = 0;
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183 imgp->auxargs = NULL;
184 imgp->vp = NULL;
185 imgp->firstpage = NULL;
186 imgp->ps_strings = 0;
18f40545 187 imgp->image_header = NULL;
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DRJ
188
189interpret:
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190
191 /*
fad57d0e
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192 * Translate the file name to a vnode. Unlock the cache entry to
193 * improve parallelism for programs exec'd in parallel.
984263bc 194 */
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195 if ((error = nlookup(nd)) != 0)
196 goto exec_fail;
197 error = cache_vget(nd->nl_ncp, nd->nl_cred, LK_EXCLUSIVE, &imgp->vp);
198 KKASSERT(nd->nl_flags & NLC_NCPISLOCKED);
199 nd->nl_flags &= ~NLC_NCPISLOCKED;
200 cache_unlock(nd->nl_ncp);
201 if (error)
984263bc 202 goto exec_fail;
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203
204 /*
205 * Check file permissions (also 'opens' file)
206 */
207 error = exec_check_permissions(imgp);
208 if (error) {
ca466bae 209 VOP_UNLOCK(imgp->vp, 0);
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210 goto exec_fail_dealloc;
211 }
212
213 error = exec_map_first_page(imgp);
ca466bae 214 VOP_UNLOCK(imgp->vp, 0);
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215 if (error)
216 goto exec_fail_dealloc;
217
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DRJ
218 if (debug_execve_args && imgp->interpreted) {
219 printf(" target is interpreted -- recursive pass\n");
220 printf(" interpreter: %s\n", imgp->interpreter_name);
221 print_execve_args(args);
222 }
223
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224 /*
225 * If the current process has a special image activator it
226 * wants to try first, call it. For example, emulating shell
227 * scripts differently.
228 */
229 error = -1;
230 if ((img_first = imgp->proc->p_sysent->sv_imgact_try) != NULL)
231 error = img_first(imgp);
232
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MD
233 /*
234 * If the vnode has a registered vmspace, exec the vmspace
235 */
236 if (error == -1 && imgp->vp->v_resident) {
237 error = exec_resident_imgact(imgp);
238 }
239
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240 /*
241 * Loop through the list of image activators, calling each one.
242 * An activator returns -1 if there is no match, 0 on success,
243 * and an error otherwise.
244 */
245 for (i = 0; error == -1 && execsw[i]; ++i) {
246 if (execsw[i]->ex_imgact == NULL ||
247 execsw[i]->ex_imgact == img_first) {
248 continue;
249 }
250 error = (*execsw[i]->ex_imgact)(imgp);
251 }
252
253 if (error) {
254 if (error == -1)
255 error = ENOEXEC;
256 goto exec_fail_dealloc;
257 }
258
259 /*
260 * Special interpreter operation, cleanup and loop up to try to
261 * activate the interpreter.
262 */
263 if (imgp->interpreted) {
264 exec_unmap_first_page(imgp);
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265 nlookup_done(nd);
266 vrele(imgp->vp);
267 imgp->vp = NULL;
268 error = nlookup_init(nd, imgp->interpreter_name, UIO_SYSSPACE,
269 NLC_FOLLOW);
270 if (error)
271 goto exec_fail;
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272 goto interpret;
273 }
274
275 /*
276 * Copy out strings (args and env) and initialize stack base
277 */
278 stack_base = exec_copyout_strings(imgp);
279 p->p_vmspace->vm_minsaddr = (char *)stack_base;
280
281 /*
282 * If custom stack fixup routine present for this process
29802dbb
MD
283 * let it do the stack setup. If we are running a resident
284 * image there is no auxinfo or other image activator context
285 * so don't try to add fixups to the stack.
286 *
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287 * Else stuff argument count as first item on stack
288 */
29802dbb 289 if (p->p_sysent->sv_fixup && imgp->resident == 0)
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290 (*p->p_sysent->sv_fixup)(&stack_base, imgp);
291 else
2bd9d75c 292 suword(--stack_base, imgp->args->argc);
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293
294 /*
295 * For security and other reasons, the file descriptor table cannot
296 * be shared after an exec.
297 */
298 if (p->p_fd->fd_refcnt > 1) {
299 struct filedesc *tmp;
300
301 tmp = fdcopy(p);
302 fdfree(p);
303 p->p_fd = tmp;
304 }
305
306 /*
307 * For security and other reasons, signal handlers cannot
308 * be shared after an exec. The new proces gets a copy of the old
309 * handlers. In execsigs(), the new process will have its signals
310 * reset.
311 */
312 if (p->p_procsig->ps_refcnt > 1) {
313 struct procsig *newprocsig;
314
315 MALLOC(newprocsig, struct procsig *, sizeof(struct procsig),
316 M_SUBPROC, M_WAITOK);
317 bcopy(p->p_procsig, newprocsig, sizeof(*newprocsig));
318 p->p_procsig->ps_refcnt--;
319 p->p_procsig = newprocsig;
320 p->p_procsig->ps_refcnt = 1;
321 if (p->p_sigacts == &p->p_addr->u_sigacts)
322 panic("shared procsig but private sigacts?");
323
324 p->p_addr->u_sigacts = *p->p_sigacts;
325 p->p_sigacts = &p->p_addr->u_sigacts;
326 }
327
328 /* Stop profiling */
329 stopprofclock(p);
330
331 /* close files on exec */
332 fdcloseexec(p);
333
334 /* reset caught signals */
335 execsigs(p);
336
337 /* name this process - nameiexec(p, ndp) */
fad57d0e
MD
338 len = min(nd->nl_ncp->nc_nlen, MAXCOMLEN);
339 bcopy(nd->nl_ncp->nc_name, p->p_comm, len);
984263bc 340 p->p_comm[len] = 0;
2966ed3e 341 bcopy(p->p_comm, p->p_lwp.lwp_thread->td_comm, MAXCOMLEN+1);
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MD
342
343 /*
344 * mark as execed, wakeup the process that vforked (if any) and tell
345 * it that it now has its own resources back
346 */
347 p->p_flag |= P_EXEC;
348 if (p->p_pptr && (p->p_flag & P_PPWAIT)) {
349 p->p_flag &= ~P_PPWAIT;
350 wakeup((caddr_t)p->p_pptr);
351 }
352
353 /*
354 * Implement image setuid/setgid.
355 *
356 * Don't honor setuid/setgid if the filesystem prohibits it or if
357 * the process is being traced.
358 */
359 if ((((attr.va_mode & VSUID) && p->p_ucred->cr_uid != attr.va_uid) ||
360 ((attr.va_mode & VSGID) && p->p_ucred->cr_gid != attr.va_gid)) &&
361 (imgp->vp->v_mount->mnt_flag & MNT_NOSUID) == 0 &&
362 (p->p_flag & P_TRACED) == 0) {
363 /*
364 * Turn off syscall tracing for set-id programs, except for
365 * root. Record any set-id flags first to make sure that
366 * we do not regain any tracing during a possible block.
367 */
41c20dac 368 setsugid();
dadab5e9 369 if (p->p_tracep && suser(td)) {
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MD
370 struct vnode *vtmp;
371
372 if ((vtmp = p->p_tracep) != NULL) {
373 p->p_tracep = NULL;
374 p->p_traceflag = 0;
375 vrele(vtmp);
376 }
377 }
378 /* Close any file descriptors 0..2 that reference procfs */
379 setugidsafety(p);
380 /* Make sure file descriptors 0..2 are in use. */
381 error = fdcheckstd(p);
382 if (error != 0)
383 goto exec_fail_dealloc;
384 /*
385 * Set the new credentials.
386 */
e9a372eb 387 cratom(&p->p_ucred);
984263bc 388 if (attr.va_mode & VSUID)
41c20dac 389 change_euid(attr.va_uid);
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MD
390 if (attr.va_mode & VSGID)
391 p->p_ucred->cr_gid = attr.va_gid;
98a7f915
MD
392
393 /*
394 * Clear local varsym variables
395 */
396 varsymset_clean(&p->p_varsymset);
984263bc 397 } else {
41c20dac
MD
398 if (p->p_ucred->cr_uid == p->p_ucred->cr_ruid &&
399 p->p_ucred->cr_gid == p->p_ucred->cr_rgid)
984263bc
MD
400 p->p_flag &= ~P_SUGID;
401 }
402
403 /*
404 * Implement correct POSIX saved-id behavior.
405 */
115ccd83
MD
406 if (p->p_ucred->cr_svuid != p->p_ucred->cr_uid ||
407 p->p_ucred->cr_svgid != p->p_ucred->cr_gid) {
408 cratom(&p->p_ucred);
409 p->p_ucred->cr_svuid = p->p_ucred->cr_uid;
410 p->p_ucred->cr_svgid = p->p_ucred->cr_gid;
411 }
984263bc
MD
412
413 /*
414 * Store the vp for use in procfs
415 */
416 if (p->p_textvp) /* release old reference */
417 vrele(p->p_textvp);
fad57d0e
MD
418 p->p_textvp = imgp->vp;
419 vref(p->p_textvp);
984263bc
MD
420
421 /*
422 * Notify others that we exec'd, and clear the P_INEXEC flag
423 * as we're now a bona fide freshly-execed process.
424 */
425 KNOTE(&p->p_klist, NOTE_EXEC);
426 p->p_flag &= ~P_INEXEC;
427
428 /*
429 * If tracing the process, trap to debugger so breakpoints
430 * can be set before the program executes.
431 */
432 STOPEVENT(p, S_EXEC, 0);
433
434 if (p->p_flag & P_TRACED)
435 psignal(p, SIGTRAP);
436
437 /* clear "fork but no exec" flag, as we _are_ execing */
438 p->p_acflag &= ~AFORK;
439
440 /* Set values passed into the program in registers. */
441 setregs(p, imgp->entry_addr, (u_long)(uintptr_t)stack_base,
442 imgp->ps_strings);
443
444 /* Free any previous argument cache */
445 if (p->p_args && --p->p_args->ar_ref == 0)
446 FREE(p->p_args, M_PARGS);
447 p->p_args = NULL;
448
449 /* Cache arguments if they fit inside our allowance */
2bd9d75c 450 i = imgp->args->begin_envv - imgp->args->begin_argv;
984263bc
MD
451 if (ps_arg_cache_limit >= i + sizeof(struct pargs)) {
452 MALLOC(p->p_args, struct pargs *, sizeof(struct pargs) + i,
453 M_PARGS, M_WAITOK);
454 p->p_args->ar_ref = 1;
455 p->p_args->ar_length = i;
2bd9d75c 456 bcopy(imgp->args->begin_argv, p->p_args->ar_args, i);
984263bc
MD
457 }
458
459exec_fail_dealloc:
460
461 /*
462 * free various allocated resources
463 */
464 if (imgp->firstpage)
465 exec_unmap_first_page(imgp);
466
984263bc 467 if (imgp->vp) {
984263bc 468 vrele(imgp->vp);
fad57d0e 469 imgp->vp = NULL;
984263bc
MD
470 }
471
a6f89c72
DR
472 if (error == 0) {
473 ++mycpu->gd_cnt.v_exec;
984263bc 474 return (0);
a6f89c72 475 }
984263bc
MD
476
477exec_fail:
478 /* we're done here, clear P_INEXEC */
479 p->p_flag &= ~P_INEXEC;
480 if (imgp->vmspace_destroyed) {
481 /* sorry, no more process anymore. exit gracefully */
41c20dac 482 exit1(W_EXITCODE(0, SIGABRT));
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MD
483 /* NOT REACHED */
484 return(0);
485 } else {
486 return(error);
487 }
488}
489
2bd9d75c
DRJ
490/*
491 * execve() system call.
492 */
493int
494execve(struct execve_args *uap)
495{
fad57d0e 496 struct nlookupdata nd;
2bd9d75c
DRJ
497 struct image_args args;
498 int error;
499
fad57d0e
MD
500 error = nlookup_init(&nd, uap->fname, UIO_USERSPACE, NLC_FOLLOW);
501 if (error == 0) {
502 error = exec_copyin_args(&args, uap->fname, PATH_USERSPACE,
503 uap->argv, uap->envv);
504 }
2abfe22f
MD
505 if (error == 0)
506 error = kern_execve(&nd, &args);
fad57d0e 507 nlookup_done(&nd);
2bd9d75c
DRJ
508 exec_free_args(&args);
509
510 /*
511 * The syscall result is returned in registers to the new program.
512 * Linux will register %edx as an atexit function and we must be
513 * sure to set it to 0. XXX
514 */
515 if (error == 0)
516 uap->sysmsg_result64 = 0;
517
518 return (error);
519}
520
984263bc 521int
41c20dac 522exec_map_first_page(struct image_params *imgp)
984263bc 523{
5fd012e0 524 int rv, i;
984263bc
MD
525 int initial_pagein;
526 vm_page_t ma[VM_INITIAL_PAGEIN];
06ecca5a 527 vm_page_t m;
984263bc
MD
528 vm_object_t object;
529
18f40545 530 if (imgp->firstpage)
984263bc 531 exec_unmap_first_page(imgp);
984263bc 532
fad57d0e 533 /*
7540ab49 534 * The file has to be mappable.
fad57d0e 535 */
7540ab49 536 if ((object = imgp->vp->v_object) == NULL)
fad57d0e 537 return (EIO);
984263bc 538
06ecca5a
MD
539 /*
540 * We shouldn't need protection for vm_page_grab() but we certainly
541 * need it for the lookup loop below (lookup/busy race), since
542 * an interrupt can unbusy and free the page before our busy check.
543 */
5fd012e0 544 crit_enter();
06ecca5a 545 m = vm_page_grab(object, 0, VM_ALLOC_NORMAL | VM_ALLOC_RETRY);
984263bc 546
06ecca5a
MD
547 if ((m->valid & VM_PAGE_BITS_ALL) != VM_PAGE_BITS_ALL) {
548 ma[0] = m;
984263bc
MD
549 initial_pagein = VM_INITIAL_PAGEIN;
550 if (initial_pagein > object->size)
551 initial_pagein = object->size;
552 for (i = 1; i < initial_pagein; i++) {
06ecca5a
MD
553 if ((m = vm_page_lookup(object, i)) != NULL) {
554 if ((m->flags & PG_BUSY) || m->busy)
984263bc 555 break;
06ecca5a 556 if (m->valid)
984263bc 557 break;
06ecca5a 558 vm_page_busy(m);
984263bc 559 } else {
06ecca5a
MD
560 m = vm_page_alloc(object, i, VM_ALLOC_NORMAL);
561 if (m == NULL)
984263bc
MD
562 break;
563 }
06ecca5a 564 ma[i] = m;
984263bc
MD
565 }
566 initial_pagein = i;
567
06ecca5a
MD
568 /*
569 * get_pages unbusies all the requested pages except the
570 * primary page (at index 0 in this case).
571 */
984263bc 572 rv = vm_pager_get_pages(object, ma, initial_pagein, 0);
06ecca5a 573 m = vm_page_lookup(object, 0);
984263bc 574
06ecca5a
MD
575 if (rv != VM_PAGER_OK || m == NULL || m->valid == 0) {
576 if (m) {
577 vm_page_protect(m, VM_PROT_NONE);
578 vm_page_free(m);
984263bc 579 }
5fd012e0 580 crit_exit();
984263bc
MD
581 return EIO;
582 }
583 }
06ecca5a
MD
584 vm_page_hold(m);
585 vm_page_wakeup(m); /* unbusy the page */
5fd012e0 586 crit_exit();
984263bc 587
4f1640d6 588 imgp->firstpage = sf_buf_alloc(m, SFB_CPUPRIVATE);
18f40545 589 imgp->image_header = (void *)sf_buf_kva(imgp->firstpage);
984263bc
MD
590
591 return 0;
592}
593
594void
77153250 595exec_unmap_first_page(struct image_params *imgp)
984263bc 596{
18f40545
MD
597 vm_page_t m;
598
5fd012e0 599 crit_enter();
18f40545
MD
600 if (imgp->firstpage != NULL) {
601 m = sf_buf_page(imgp->firstpage);
602 sf_buf_free(imgp->firstpage);
984263bc 603 imgp->firstpage = NULL;
18f40545 604 imgp->image_header = NULL;
e4ba7818 605 vm_page_unhold(m);
984263bc 606 }
5fd012e0 607 crit_exit();
984263bc
MD
608}
609
610/*
611 * Destroy old address space, and allocate a new stack
612 * The new stack is only SGROWSIZ large because it is grown
613 * automatically in trap.c.
614 */
615int
29802dbb 616exec_new_vmspace(struct image_params *imgp, struct vmspace *vmcopy)
984263bc
MD
617{
618 int error;
619 struct vmspace *vmspace = imgp->proc->p_vmspace;
620 vm_offset_t stack_addr = USRSTACK - maxssiz;
29802dbb 621 vm_map_t map;
984263bc
MD
622
623 imgp->vmspace_destroyed = 1;
624
625 /*
626 * Prevent a pending AIO from modifying the new address space.
627 */
628 aio_proc_rundown(imgp->proc);
629
630 /*
631 * Blow away entire process VM, if address space not shared,
632 * otherwise, create a new VM space so that other threads are
29802dbb
MD
633 * not disrupted. If we are execing a resident vmspace we
634 * create a duplicate of it and remap the stack.
239b4df9
MD
635 *
636 * The exitingcnt test is not strictly necessary but has been
637 * included for code sanity (to make the code more deterministic).
984263bc 638 */
29802dbb
MD
639 map = &vmspace->vm_map;
640 if (vmcopy) {
641 vmspace_exec(imgp->proc, vmcopy);
642 vmspace = imgp->proc->p_vmspace;
643 pmap_remove_pages(vmspace_pmap(vmspace), stack_addr, USRSTACK);
644 map = &vmspace->vm_map;
239b4df9 645 } else if (vmspace->vm_refcnt == 1 && vmspace->vm_exitingcnt == 0) {
fef0fdf2 646 shmexit(vmspace);
239b4df9 647 if (vmspace->vm_upcalls)
4170cc8b 648 upc_release(vmspace, &imgp->proc->p_lwp);
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MD
649 pmap_remove_pages(vmspace_pmap(vmspace), 0, VM_MAXUSER_ADDRESS);
650 vm_map_remove(map, 0, VM_MAXUSER_ADDRESS);
651 } else {
29802dbb 652 vmspace_exec(imgp->proc, NULL);
984263bc
MD
653 vmspace = imgp->proc->p_vmspace;
654 map = &vmspace->vm_map;
655 }
656
657 /* Allocate a new stack */
658 error = vm_map_stack(&vmspace->vm_map, stack_addr, (vm_size_t)maxssiz,
659 VM_PROT_ALL, VM_PROT_ALL, 0);
660 if (error)
661 return (error);
662
663 /* vm_ssize and vm_maxsaddr are somewhat antiquated concepts in the
664 * VM_STACK case, but they are still used to monitor the size of the
665 * process stack so we can check the stack rlimit.
666 */
667 vmspace->vm_ssize = sgrowsiz >> PAGE_SHIFT;
668 vmspace->vm_maxsaddr = (char *)USRSTACK - maxssiz;
669
670 return(0);
671}
672
673/*
674 * Copy out argument and environment strings from the old process
675 * address space into the temporary string buffer.
676 */
677int
2bd9d75c 678exec_copyin_args(struct image_args *args, char *fname,
2abfe22f 679 enum exec_path_segflg segflg, char **argv, char **envv)
984263bc 680{
984263bc 681 char *argp, *envp;
2bd9d75c 682 int error = 0;
984263bc
MD
683 size_t length;
684
2abfe22f 685 bzero(args, sizeof(*args));
2bd9d75c
DRJ
686 args->buf = (char *) kmem_alloc_wait(exec_map, PATH_MAX + ARG_MAX);
687 if (args->buf == NULL)
688 return (ENOMEM);
689 args->begin_argv = args->buf;
690 args->endp = args->begin_argv;
691 args->space = ARG_MAX;
2bd9d75c
DRJ
692
693 args->fname = args->buf + ARG_MAX;
694
984263bc 695 /*
2bd9d75c 696 * Copy the file name.
984263bc 697 */
2bd9d75c
DRJ
698 if (segflg == PATH_SYSSPACE) {
699 error = copystr(fname, args->fname, PATH_MAX, &length);
700 } else if (segflg == PATH_USERSPACE) {
701 error = copyinstr(fname, args->fname, PATH_MAX, &length);
702 }
984263bc 703
2bd9d75c 704 /*
66be6566
MD
705 * Extract argument strings. argv may not be NULL. The argv
706 * array is terminated by a NULL entry. We special-case the
707 * situation where argv[0] is NULL by passing { filename, NULL }
708 * to the new program to guarentee that the interpreter knows what
709 * file to open in case we exec an interpreted file. Note that
710 * a NULL argv[0] terminates the argv[] array.
711 *
712 * XXX the special-casing of argv[0] is historical and needs to be
713 * revisited.
2bd9d75c 714 */
66be6566
MD
715 if (argv == NULL)
716 error = EFAULT;
717 if (error == 0) {
718 while ((argp = (caddr_t)(intptr_t)fuword(argv++)) != NULL) {
719 if (argp == (caddr_t)-1) {
2bd9d75c 720 error = EFAULT;
66be6566 721 break;
2bd9d75c
DRJ
722 }
723 error = copyinstr(argp, args->endp,
2abfe22f 724 args->space, &length);
66be6566
MD
725 if (error) {
726 if (error == ENAMETOOLONG)
727 error = E2BIG;
728 break;
729 }
2bd9d75c
DRJ
730 args->space -= length;
731 args->endp += length;
732 args->argc++;
984263bc 733 }
66be6566
MD
734 if (args->argc == 0 && error == 0) {
735 length = strlen(args->fname) + 1;
736 if (length > args->space) {
737 error = E2BIG;
738 } else {
739 bcopy(args->fname, args->endp, length);
740 args->space -= length;
741 args->endp += length;
742 args->argc++;
743 }
744 }
984263bc
MD
745 }
746
2bd9d75c 747 args->begin_envv = args->endp;
984263bc
MD
748
749 /*
66be6566 750 * extract environment strings. envv may be NULL.
984263bc 751 */
2abfe22f 752 if (envv && error == 0) {
984263bc 753 while ((envp = (caddr_t) (intptr_t) fuword(envv++))) {
2bd9d75c
DRJ
754 if (envp == (caddr_t) -1) {
755 error = EFAULT;
66be6566 756 break;
984263bc 757 }
2bd9d75c
DRJ
758 error = copyinstr(envp, args->endp, args->space,
759 &length);
66be6566
MD
760 if (error) {
761 if (error == ENAMETOOLONG)
762 error = E2BIG;
763 break;
764 }
2bd9d75c
DRJ
765 args->space -= length;
766 args->endp += length;
767 args->envc++;
984263bc
MD
768 }
769 }
2bd9d75c
DRJ
770 return (error);
771}
772
773void
774exec_free_args(struct image_args *args)
775{
2abfe22f
MD
776 if (args->buf) {
777 kmem_free_wakeup(exec_map,
778 (vm_offset_t)args->buf, PATH_MAX + ARG_MAX);
779 args->buf = NULL;
780 }
984263bc
MD
781}
782
783/*
784 * Copy strings out to the new process address space, constructing
785 * new arg and env vector tables. Return a pointer to the base
786 * so that it can be used as the initial stack pointer.
787 */
788register_t *
2bd9d75c 789exec_copyout_strings(struct image_params *imgp)
984263bc 790{
17a7ca1f 791 int argc, envc, sgap;
984263bc
MD
792 char **vectp;
793 char *stringp, *destp;
794 register_t *stack_base;
795 struct ps_strings *arginfo;
796 int szsigcode;
797
798 /*
799 * Calculate string base and vector table pointers.
800 * Also deal with signal trampoline code for this exec type.
801 */
802 arginfo = (struct ps_strings *)PS_STRINGS;
803 szsigcode = *(imgp->proc->p_sysent->sv_szsigcode);
17a7ca1f
MD
804 if (stackgap_random != 0)
805 sgap = ALIGN(arc4random() & (stackgap_random - 1));
806 else
807 sgap = 0;
808 destp = (caddr_t)arginfo - szsigcode - SPARE_USRSPACE - sgap -
2bd9d75c 809 roundup((ARG_MAX - imgp->args->space), sizeof(char *));
984263bc
MD
810
811 /*
812 * install sigcode
813 */
814 if (szsigcode)
815 copyout(imgp->proc->p_sysent->sv_sigcode,
2bd9d75c 816 ((caddr_t)arginfo - szsigcode), szsigcode);
984263bc
MD
817
818 /*
819 * If we have a valid auxargs ptr, prepare some room
820 * on the stack.
7ec1918b 821 *
984263bc
MD
822 * The '+ 2' is for the null pointers at the end of each of the
823 * arg and env vector sets, and 'AT_COUNT*2' is room for the
824 * ELF Auxargs data.
825 */
7ec1918b
MD
826 if (imgp->auxargs) {
827 vectp = (char **)(destp - (imgp->args->argc +
828 imgp->args->envc + 2 + AT_COUNT * 2) * sizeof(char*));
829 } else {
2bd9d75c 830 vectp = (char **)(destp - (imgp->args->argc +
7ec1918b
MD
831 imgp->args->envc + 2) * sizeof(char*));
832 }
833
984263bc 834 /*
31bc42c8
MD
835 * NOTE: don't bother aligning the stack here for GCC 2.x, it will
836 * be done in crt1.o. Note that GCC 3.x aligns the stack in main.
984263bc 837 */
984263bc
MD
838
839 /*
840 * vectp also becomes our initial stack base
841 */
842 stack_base = (register_t *)vectp;
843
2bd9d75c
DRJ
844 stringp = imgp->args->begin_argv;
845 argc = imgp->args->argc;
846 envc = imgp->args->envc;
984263bc
MD
847
848 /*
849 * Copy out strings - arguments and environment.
850 */
2bd9d75c 851 copyout(stringp, destp, ARG_MAX - imgp->args->space);
984263bc
MD
852
853 /*
854 * Fill in "ps_strings" struct for ps, w, etc.
855 */
856 suword(&arginfo->ps_argvstr, (long)(intptr_t)vectp);
857 suword(&arginfo->ps_nargvstr, argc);
858
859 /*
860 * Fill in argument portion of vector table.
861 */
862 for (; argc > 0; --argc) {
863 suword(vectp++, (long)(intptr_t)destp);
864 while (*stringp++ != 0)
865 destp++;
866 destp++;
867 }
868
7a44d1cb 869 /* a null vector table pointer separates the argp's from the envp's */
984263bc
MD
870 suword(vectp++, 0);
871
872 suword(&arginfo->ps_envstr, (long)(intptr_t)vectp);
873 suword(&arginfo->ps_nenvstr, envc);
874
875 /*
876 * Fill in environment portion of vector table.
877 */
878 for (; envc > 0; --envc) {
879 suword(vectp++, (long)(intptr_t)destp);
880 while (*stringp++ != 0)
881 destp++;
882 destp++;
883 }
884
885 /* end of vector table is a null pointer */
886 suword(vectp, 0);
887
888 return (stack_base);
889}
890
891/*
892 * Check permissions of file to execute.
893 * Return 0 for success or error code on failure.
894 */
895int
77153250 896exec_check_permissions(struct image_params *imgp)
984263bc
MD
897{
898 struct proc *p = imgp->proc;
899 struct vnode *vp = imgp->vp;
900 struct vattr *attr = imgp->attr;
901 int error;
902
903 /* Get file attributes */
87de5057 904 error = VOP_GETATTR(vp, attr);
984263bc
MD
905 if (error)
906 return (error);
907
908 /*
909 * 1) Check if file execution is disabled for the filesystem that this
910 * file resides on.
911 * 2) Insure that at least one execute bit is on - otherwise root
912 * will always succeed, and we don't want to happen unless the
913 * file really is executable.
914 * 3) Insure that the file is a regular file.
915 */
916 if ((vp->v_mount->mnt_flag & MNT_NOEXEC) ||
917 ((attr->va_mode & 0111) == 0) ||
918 (attr->va_type != VREG)) {
919 return (EACCES);
920 }
921
922 /*
923 * Zero length files can't be exec'd
924 */
925 if (attr->va_size == 0)
926 return (ENOEXEC);
927
928 /*
929 * Check for execute permission to file based on current credentials.
930 */
87de5057 931 error = VOP_ACCESS(vp, VEXEC, p->p_ucred);
984263bc
MD
932 if (error)
933 return (error);
934
935 /*
936 * Check number of open-for-writes on the file and deny execution
937 * if there are any.
938 */
939 if (vp->v_writecount)
940 return (ETXTBSY);
941
942 /*
7540ab49
MD
943 * Call filesystem specific open routine, which allows us to read,
944 * write, and mmap the file. Without the VOP_OPEN we can only
945 * stat the file.
984263bc 946 */
87de5057 947 error = VOP_OPEN(vp, FREAD, p->p_ucred, NULL);
984263bc
MD
948 if (error)
949 return (error);
950
951 return (0);
952}
953
954/*
955 * Exec handler registration
956 */
957int
77153250 958exec_register(const struct execsw *execsw_arg)
984263bc
MD
959{
960 const struct execsw **es, **xs, **newexecsw;
961 int count = 2; /* New slot and trailing NULL */
962
963 if (execsw)
964 for (es = execsw; *es; es++)
965 count++;
966 newexecsw = malloc(count * sizeof(*es), M_TEMP, M_WAITOK);
967 if (newexecsw == NULL)
968 return ENOMEM;
969 xs = newexecsw;
970 if (execsw)
971 for (es = execsw; *es; es++)
972 *xs++ = *es;
973 *xs++ = execsw_arg;
974 *xs = NULL;
975 if (execsw)
976 free(execsw, M_TEMP);
977 execsw = newexecsw;
978 return 0;
979}
980
981int
77153250 982exec_unregister(const struct execsw *execsw_arg)
984263bc
MD
983{
984 const struct execsw **es, **xs, **newexecsw;
985 int count = 1;
986
987 if (execsw == NULL)
ae7e74d4 988 panic("unregister with no handlers left?");
984263bc
MD
989
990 for (es = execsw; *es; es++) {
991 if (*es == execsw_arg)
992 break;
993 }
994 if (*es == NULL)
995 return ENOENT;
996 for (es = execsw; *es; es++)
997 if (*es != execsw_arg)
998 count++;
999 newexecsw = malloc(count * sizeof(*es), M_TEMP, M_WAITOK);
1000 if (newexecsw == NULL)
1001 return ENOMEM;
1002 xs = newexecsw;
1003 for (es = execsw; *es; es++)
1004 if (*es != execsw_arg)
1005 *xs++ = *es;
1006 *xs = NULL;
1007 if (execsw)
1008 free(execsw, M_TEMP);
1009 execsw = newexecsw;
1010 return 0;
1011}