Remove two more files by 'make upgrade'.
[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 $
27 */
28
29#include <sys/param.h>
30#include <sys/systm.h>
31#include <sys/sysproto.h>
32#include <sys/kernel.h>
33#include <sys/mount.h>
34#include <sys/filedesc.h>
35#include <sys/fcntl.h>
36#include <sys/acct.h>
37#include <sys/exec.h>
38#include <sys/imgact.h>
39#include <sys/imgact_elf.h>
2bd9d75c 40#include <sys/kern_syscall.h>
984263bc
MD
41#include <sys/wait.h>
42#include <sys/malloc.h>
43#include <sys/proc.h>
895c1f85 44#include <sys/priv.h>
29f58392 45#include <sys/ktrace.h>
984263bc
MD
46#include <sys/signalvar.h>
47#include <sys/pioctl.h>
fad57d0e 48#include <sys/nlookup.h>
984263bc
MD
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>
17a7ca1f 54#include <sys/libkern.h>
984263bc 55
5c5185ae
SG
56#include <cpu/lwbuf.h>
57
984263bc
MD
58#include <vm/vm.h>
59#include <vm/vm_param.h>
60#include <sys/lock.h>
61#include <vm/pmap.h>
62#include <vm/vm_page.h>
63#include <vm/vm_map.h>
64#include <vm/vm_kern.h>
65#include <vm/vm_extern.h>
66#include <vm/vm_object.h>
a55afca2 67#include <vm/vnode_pager.h>
984263bc
MD
68#include <vm/vm_pager.h>
69
70#include <sys/user.h>
527fddf7 71#include <sys/reg.h>
984263bc 72
22b7a3db 73#include <sys/objcache.h>
19bfc8ab 74#include <sys/refcount.h>
5fd012e0 75#include <sys/thread2.h>
a86ce0cd 76#include <vm/vm_page2.h>
5fd012e0 77
984263bc 78MALLOC_DEFINE(M_PARGS, "proc-args", "Process arguments");
18b3f457 79MALLOC_DEFINE(M_EXECARGS, "exec-args", "Exec arguments");
984263bc 80
402ed7e1 81static register_t *exec_copyout_strings (struct image_params *);
984263bc
MD
82
83/* XXX This should be vm_size_t. */
84static u_long ps_strings = PS_STRINGS;
85SYSCTL_ULONG(_kern, KERN_PS_STRINGS, ps_strings, CTLFLAG_RD, &ps_strings, 0, "");
86
87/* XXX This should be vm_size_t. */
88static u_long usrstack = USRSTACK;
89SYSCTL_ULONG(_kern, KERN_USRSTACK, usrstack, CTLFLAG_RD, &usrstack, 0, "");
90
91u_long ps_arg_cache_limit = PAGE_SIZE / 16;
92SYSCTL_LONG(_kern, OID_AUTO, ps_arg_cache_limit, CTLFLAG_RW,
93 &ps_arg_cache_limit, 0, "");
94
95int ps_argsopen = 1;
96SYSCTL_INT(_kern, OID_AUTO, ps_argsopen, CTLFLAG_RW, &ps_argsopen, 0, "");
97
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MD
98static int ktrace_suid = 0;
99SYSCTL_INT(_kern, OID_AUTO, ktrace_suid, CTLFLAG_RW, &ktrace_suid, 0, "");
100
2bd9d75c
DRJ
101void print_execve_args(struct image_args *args);
102int debug_execve_args = 0;
103SYSCTL_INT(_kern, OID_AUTO, debug_execve_args, CTLFLAG_RW, &debug_execve_args,
104 0, "");
105
18b3f457
MD
106/*
107 * Exec arguments object cache
108 */
109static struct objcache *exec_objcache;
110
111static
112void
113exec_objcache_init(void *arg __unused)
114{
0aa16b5d 115 int cluster_limit;
1f29f2c5
MD
116 size_t limsize;
117
118 /*
119 * Maximum number of concurrent execs. This can be limiting on
120 * systems with a lot of cpu cores but it also eats a significant
121 * amount of memory.
122 */
e93da8d4 123 cluster_limit = (ncpus < 16) ? 16 : ncpus;
1f29f2c5
MD
124 limsize = kmem_lim_size();
125 if (limsize > 7 * 1024)
126 cluster_limit *= 2;
127 if (limsize > 15 * 1024)
128 cluster_limit *= 2;
0aa16b5d 129
18b3f457
MD
130 exec_objcache = objcache_create_mbacked(
131 M_EXECARGS, PATH_MAX + ARG_MAX,
2fce2579 132 cluster_limit, 8,
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MD
133 NULL, NULL, NULL);
134}
135SYSINIT(exec_objcache, SI_BOOT2_MACHDEP, SI_ORDER_ANY, exec_objcache_init, 0);
136
17a7ca1f
MD
137/*
138 * stackgap_random specifies if the stackgap should have a random size added
139 * to it. It must be a power of 2. If non-zero, the stack gap will be
0ced1954 140 * calculated as: ALIGN(karc4random() & (stackgap_random - 1)).
17a7ca1f
MD
141 */
142static int stackgap_random = 1024;
143static int
144sysctl_kern_stackgap(SYSCTL_HANDLER_ARGS)
145{
146 int error, new_val;
147 new_val = stackgap_random;
148 error = sysctl_handle_int(oidp, &new_val, 0, req);
149 if (error != 0 || req->newptr == NULL)
150 return (error);
d0e92318 151 if (new_val > 0 && ((new_val > 16 * PAGE_SIZE) || !powerof2(new_val)))
17a7ca1f
MD
152 return (EINVAL);
153 stackgap_random = new_val;
154
155 return(0);
156}
157
d0e92318 158SYSCTL_PROC(_kern, OID_AUTO, stackgap_random, CTLFLAG_RW|CTLTYPE_INT,
1237359e 159 0, 0, sysctl_kern_stackgap, "I",
d0e92318 160 "Max random stack gap (power of 2), static gap if negative");
e6141a7f 161
2bd9d75c
DRJ
162void
163print_execve_args(struct image_args *args)
164{
165 char *cp;
166 int ndx;
167
168 cp = args->begin_argv;
169 for (ndx = 0; ndx < args->argc; ndx++) {
6ea70f76 170 kprintf("\targv[%d]: %s\n", ndx, cp);
2bd9d75c
DRJ
171 while (*cp++ != '\0');
172 }
173 for (ndx = 0; ndx < args->envc; ndx++) {
6ea70f76 174 kprintf("\tenvv[%d]: %s\n", ndx, cp);
2bd9d75c
DRJ
175 while (*cp++ != '\0');
176 }
177}
178
984263bc
MD
179/*
180 * Each of the items is a pointer to a `const struct execsw', hence the
181 * double pointer here.
182 */
183static const struct execsw **execsw;
184
5417cd57
SS
185/*
186 * Replace current vmspace with a new binary.
187 * Returns 0 on success, > 0 on recoverable error (use as errno).
90947cb1 188 * Returns -1 on lethal error which demands killing of the current
5417cd57
SS
189 * process!
190 */
984263bc 191int
fad57d0e 192kern_execve(struct nlookupdata *nd, struct image_args *args)
984263bc 193{
dadab5e9 194 struct thread *td = curthread;
08f2f1bb 195 struct lwp *lp = td->td_lwp;
dadab5e9 196 struct proc *p = td->td_proc;
a2ee730d 197 struct vnode *ovp;
984263bc 198 register_t *stack_base;
19bfc8ab 199 struct pargs *pa;
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MD
200 struct sigacts *ops;
201 struct sigacts *nps;
984263bc
MD
202 int error, len, i;
203 struct image_params image_params, *imgp;
204 struct vattr attr;
402ed7e1 205 int (*img_first) (struct image_params *);
984263bc 206
2bd9d75c 207 if (debug_execve_args) {
6ea70f76 208 kprintf("%s()\n", __func__);
2bd9d75c
DRJ
209 print_execve_args(args);
210 }
211
dadab5e9 212 KKASSERT(p);
19bfc8ab 213 lwkt_gettoken(&p->p_token);
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MD
214 imgp = &image_params;
215
216 /*
dc52e1cc
MD
217 * NOTE: P_INEXEC is handled by exec_new_vmspace() now. We make
218 * no modifications to the process at all until we get there.
219 *
220 * Note that multiple threads may be trying to exec at the same
221 * time. exec_new_vmspace() handles that too.
984263bc 222 */
984263bc
MD
223
224 /*
225 * Initialize part of the common data
226 */
227 imgp->proc = p;
2bd9d75c 228 imgp->args = args;
984263bc 229 imgp->attr = &attr;
984263bc 230 imgp->entry_addr = 0;
29802dbb 231 imgp->resident = 0;
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MD
232 imgp->vmspace_destroyed = 0;
233 imgp->interpreted = 0;
2abfe22f 234 imgp->interpreter_name[0] = 0;
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MD
235 imgp->auxargs = NULL;
236 imgp->vp = NULL;
237 imgp->firstpage = NULL;
238 imgp->ps_strings = 0;
adc42cf3
JM
239 imgp->execpath = imgp->freepath = NULL;
240 imgp->execpathp = 0;
18f40545 241 imgp->image_header = NULL;
2bd9d75c
DRJ
242
243interpret:
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MD
244
245 /*
fad57d0e
MD
246 * Translate the file name to a vnode. Unlock the cache entry to
247 * improve parallelism for programs exec'd in parallel.
984263bc 248 */
12cdc371 249 nd->nl_flags |= NLC_SHAREDLOCK;
fad57d0e
MD
250 if ((error = nlookup(nd)) != 0)
251 goto exec_fail;
12cdc371 252 error = cache_vget(&nd->nl_nch, nd->nl_cred, LK_SHARED, &imgp->vp);
fad57d0e
MD
253 KKASSERT(nd->nl_flags & NLC_NCPISLOCKED);
254 nd->nl_flags &= ~NLC_NCPISLOCKED;
28623bf9 255 cache_unlock(&nd->nl_nch);
fad57d0e 256 if (error)
984263bc 257 goto exec_fail;
984263bc
MD
258
259 /*
246693ac
AHJ
260 * Check file permissions (also 'opens' file).
261 * Include also the top level mount in the check.
984263bc 262 */
246693ac 263 error = exec_check_permissions(imgp, nd->nl_nch.mount);
984263bc 264 if (error) {
a11aaa81 265 vn_unlock(imgp->vp);
984263bc
MD
266 goto exec_fail_dealloc;
267 }
268
269 error = exec_map_first_page(imgp);
a11aaa81 270 vn_unlock(imgp->vp);
984263bc
MD
271 if (error)
272 goto exec_fail_dealloc;
273
315b8b8b
JM
274 imgp->proc->p_osrel = 0;
275
2bd9d75c 276 if (debug_execve_args && imgp->interpreted) {
6ea70f76
SW
277 kprintf(" target is interpreted -- recursive pass\n");
278 kprintf(" interpreter: %s\n", imgp->interpreter_name);
2bd9d75c
DRJ
279 print_execve_args(args);
280 }
281
984263bc
MD
282 /*
283 * If the current process has a special image activator it
284 * wants to try first, call it. For example, emulating shell
285 * scripts differently.
286 */
287 error = -1;
288 if ((img_first = imgp->proc->p_sysent->sv_imgact_try) != NULL)
289 error = img_first(imgp);
290
29802dbb
MD
291 /*
292 * If the vnode has a registered vmspace, exec the vmspace
293 */
294 if (error == -1 && imgp->vp->v_resident) {
295 error = exec_resident_imgact(imgp);
296 }
297
984263bc
MD
298 /*
299 * Loop through the list of image activators, calling each one.
300 * An activator returns -1 if there is no match, 0 on success,
301 * and an error otherwise.
302 */
303 for (i = 0; error == -1 && execsw[i]; ++i) {
304 if (execsw[i]->ex_imgact == NULL ||
305 execsw[i]->ex_imgact == img_first) {
306 continue;
307 }
308 error = (*execsw[i]->ex_imgact)(imgp);
309 }
310
311 if (error) {
312 if (error == -1)
313 error = ENOEXEC;
314 goto exec_fail_dealloc;
315 }
316
317 /*
318 * Special interpreter operation, cleanup and loop up to try to
319 * activate the interpreter.
320 */
321 if (imgp->interpreted) {
322 exec_unmap_first_page(imgp);
fad57d0e
MD
323 nlookup_done(nd);
324 vrele(imgp->vp);
325 imgp->vp = NULL;
326 error = nlookup_init(nd, imgp->interpreter_name, UIO_SYSSPACE,
327 NLC_FOLLOW);
328 if (error)
329 goto exec_fail;
984263bc
MD
330 goto interpret;
331 }
332
adc42cf3
JM
333 /*
334 * Do the best to calculate the full path to the image file
335 */
336 if (imgp->auxargs != NULL &&
337 ((args->fname != NULL && args->fname[0] == '/') ||
338 vn_fullpath(imgp->proc,
339 imgp->vp,
340 &imgp->execpath,
341 &imgp->freepath,
342 0) != 0))
343 imgp->execpath = args->fname;
344
984263bc
MD
345 /*
346 * Copy out strings (args and env) and initialize stack base
347 */
348 stack_base = exec_copyout_strings(imgp);
349 p->p_vmspace->vm_minsaddr = (char *)stack_base;
350
351 /*
352 * If custom stack fixup routine present for this process
29802dbb
MD
353 * let it do the stack setup. If we are running a resident
354 * image there is no auxinfo or other image activator context
355 * so don't try to add fixups to the stack.
356 *
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MD
357 * Else stuff argument count as first item on stack
358 */
29802dbb 359 if (p->p_sysent->sv_fixup && imgp->resident == 0)
984263bc
MD
360 (*p->p_sysent->sv_fixup)(&stack_base, imgp);
361 else
5947157e 362 suword64(--stack_base, imgp->args->argc);
984263bc
MD
363
364 /*
365 * For security and other reasons, the file descriptor table cannot
366 * be shared after an exec.
367 */
368 if (p->p_fd->fd_refcnt > 1) {
369 struct filedesc *tmp;
370
2994659f
VS
371 error = fdcopy(p, &tmp);
372 if (error != 0)
373 goto exec_fail;
0a4a9c77 374 fdfree(p, tmp);
984263bc
MD
375 }
376
377 /*
378 * For security and other reasons, signal handlers cannot
379 * be shared after an exec. The new proces gets a copy of the old
380 * handlers. In execsigs(), the new process will have its signals
381 * reset.
382 */
6fa9e71a
MD
383 ops = p->p_sigacts;
384 if (ops->ps_refcnt > 1) {
385 nps = kmalloc(sizeof(*nps), M_SUBPROC, M_WAITOK);
386 bcopy(ops, nps, sizeof(*nps));
387 refcount_init(&nps->ps_refcnt, 1);
388 p->p_sigacts = nps;
389 if (refcount_release(&ops->ps_refcnt)) {
390 kfree(ops, M_SUBPROC);
391 ops = NULL;
392 }
984263bc
MD
393 }
394
0daa37a5
MD
395 /*
396 * For security and other reasons virtual kernels cannot be
397 * inherited by an exec. This also allows a virtual kernel
398 * to fork/exec unrelated applications.
399 */
4a22e893
MD
400 if (p->p_vkernel)
401 vkernel_exit(p);
0daa37a5 402
984263bc
MD
403 /* Stop profiling */
404 stopprofclock(p);
405
406 /* close files on exec */
407 fdcloseexec(p);
408
409 /* reset caught signals */
410 execsigs(p);
411
412 /* name this process - nameiexec(p, ndp) */
28623bf9
MD
413 len = min(nd->nl_nch.ncp->nc_nlen, MAXCOMLEN);
414 bcopy(nd->nl_nch.ncp->nc_name, p->p_comm, len);
984263bc 415 p->p_comm[len] = 0;
08f2f1bb 416 bcopy(p->p_comm, lp->lwp_thread->td_comm, MAXCOMLEN+1);
984263bc
MD
417
418 /*
419 * mark as execed, wakeup the process that vforked (if any) and tell
420 * it that it now has its own resources back
51818c08
MD
421 *
422 * We are using the P_PPWAIT as an interlock so an atomic op is
423 * necessary to synchronize with the parent's cpu.
984263bc 424 */
4643740a
MD
425 p->p_flags |= P_EXEC;
426 if (p->p_pptr && (p->p_flags & P_PPWAIT)) {
87116512 427 if (p->p_pptr->p_upmap)
2eca01a4 428 atomic_add_int(&p->p_pptr->p_upmap->invfork, -1);
51818c08
MD
429 atomic_clear_int(&p->p_flags, P_PPWAIT);
430 wakeup(p->p_pptr);
984263bc
MD
431 }
432
433 /*
434 * Implement image setuid/setgid.
435 *
436 * Don't honor setuid/setgid if the filesystem prohibits it or if
437 * the process is being traced.
438 */
439 if ((((attr.va_mode & VSUID) && p->p_ucred->cr_uid != attr.va_uid) ||
440 ((attr.va_mode & VSGID) && p->p_ucred->cr_gid != attr.va_gid)) &&
441 (imgp->vp->v_mount->mnt_flag & MNT_NOSUID) == 0 &&
4643740a 442 (p->p_flags & P_TRACED) == 0) {
984263bc
MD
443 /*
444 * Turn off syscall tracing for set-id programs, except for
445 * root. Record any set-id flags first to make sure that
446 * we do not regain any tracing during a possible block.
447 */
41c20dac 448 setsugid();
5c627295
MD
449 if (p->p_tracenode && ktrace_suid == 0 &&
450 priv_check(td, PRIV_ROOT) != 0) {
29f58392
MD
451 ktrdestroy(&p->p_tracenode);
452 p->p_traceflag = 0;
984263bc
MD
453 }
454 /* Close any file descriptors 0..2 that reference procfs */
455 setugidsafety(p);
456 /* Make sure file descriptors 0..2 are in use. */
f3a2d8c4 457 error = fdcheckstd(lp);
984263bc
MD
458 if (error != 0)
459 goto exec_fail_dealloc;
460 /*
461 * Set the new credentials.
462 */
24207b1e 463 cratom_proc(p);
984263bc 464 if (attr.va_mode & VSUID)
41c20dac 465 change_euid(attr.va_uid);
984263bc
MD
466 if (attr.va_mode & VSGID)
467 p->p_ucred->cr_gid = attr.va_gid;
98a7f915
MD
468
469 /*
470 * Clear local varsym variables
471 */
472 varsymset_clean(&p->p_varsymset);
984263bc 473 } else {
41c20dac
MD
474 if (p->p_ucred->cr_uid == p->p_ucred->cr_ruid &&
475 p->p_ucred->cr_gid == p->p_ucred->cr_rgid)
4643740a 476 p->p_flags &= ~P_SUGID;
984263bc
MD
477 }
478
479 /*
480 * Implement correct POSIX saved-id behavior.
481 */
115ccd83
MD
482 if (p->p_ucred->cr_svuid != p->p_ucred->cr_uid ||
483 p->p_ucred->cr_svgid != p->p_ucred->cr_gid) {
24207b1e 484 cratom_proc(p);
115ccd83
MD
485 p->p_ucred->cr_svuid = p->p_ucred->cr_uid;
486 p->p_ucred->cr_svgid = p->p_ucred->cr_gid;
487 }
984263bc
MD
488
489 /*
a2ee730d
MD
490 * Store the vp for use in procfs. Be sure to keep p_textvp
491 * consistent if we block during the switch-over.
984263bc 492 */
a2ee730d
MD
493 ovp = p->p_textvp;
494 vref(imgp->vp); /* ref new vp */
fad57d0e 495 p->p_textvp = imgp->vp;
a2ee730d
MD
496 if (ovp) /* release old vp */
497 vrele(ovp);
984263bc 498
8ba5f7ef
AH
499 /* Release old namecache handle to text file */
500 if (p->p_textnch.ncp)
501 cache_drop(&p->p_textnch);
502
503 if (nd->nl_nch.mount)
504 cache_copy(&nd->nl_nch, &p->p_textnch);
505
984263bc
MD
506 /*
507 * Notify others that we exec'd, and clear the P_INEXEC flag
508 * as we're now a bona fide freshly-execed process.
509 */
510 KNOTE(&p->p_klist, NOTE_EXEC);
4643740a 511 p->p_flags &= ~P_INEXEC;
b2a6ad87
MD
512 if (p->p_stops)
513 wakeup(&p->p_stype);
984263bc
MD
514
515 /*
516 * If tracing the process, trap to debugger so breakpoints
517 * can be set before the program executes.
518 */
519 STOPEVENT(p, S_EXEC, 0);
520
4643740a 521 if (p->p_flags & P_TRACED)
84204577 522 ksignal(p, SIGTRAP);
984263bc
MD
523
524 /* clear "fork but no exec" flag, as we _are_ execing */
525 p->p_acflag &= ~AFORK;
526
527 /* Set values passed into the program in registers. */
08f2f1bb 528 exec_setregs(imgp->entry_addr, (u_long)(uintptr_t)stack_base,
a2ee730d 529 imgp->ps_strings);
984263bc 530
349433c9
MD
531 /* Set the access time on the vnode */
532 vn_mark_atime(imgp->vp, td);
533
19bfc8ab
MD
534 /*
535 * Free any previous argument cache
536 */
537 pa = p->p_args;
984263bc 538 p->p_args = NULL;
19bfc8ab
MD
539 if (pa && refcount_release(&pa->ar_ref)) {
540 kfree(pa, M_PARGS);
541 pa = NULL;
542 }
984263bc 543
19bfc8ab
MD
544 /*
545 * Cache arguments if they fit inside our allowance
546 */
2bd9d75c 547 i = imgp->args->begin_envv - imgp->args->begin_argv;
19bfc8ab
MD
548 if (sizeof(struct pargs) + i <= ps_arg_cache_limit) {
549 pa = kmalloc(sizeof(struct pargs) + i, M_PARGS, M_WAITOK);
550 refcount_init(&pa->ar_ref, 1);
551 pa->ar_length = i;
552 bcopy(imgp->args->begin_argv, pa->ar_args, i);
553 KKASSERT(p->p_args == NULL);
554 p->p_args = pa;
984263bc
MD
555 }
556
557exec_fail_dealloc:
558
559 /*
560 * free various allocated resources
561 */
562 if (imgp->firstpage)
563 exec_unmap_first_page(imgp);
564
984263bc 565 if (imgp->vp) {
984263bc 566 vrele(imgp->vp);
fad57d0e 567 imgp->vp = NULL;
984263bc
MD
568 }
569
bf52a6ac
MD
570 if (imgp->freepath)
571 kfree(imgp->freepath, M_TEMP);
572
a6f89c72
DR
573 if (error == 0) {
574 ++mycpu->gd_cnt.v_exec;
19bfc8ab 575 lwkt_reltoken(&p->p_token);
984263bc 576 return (0);
a6f89c72 577 }
984263bc
MD
578
579exec_fail:
dc52e1cc
MD
580 /*
581 * we're done here, clear P_INEXEC if we were the ones that
582 * set it. Otherwise if vmspace_destroyed is still set we
583 * raced another thread and that thread is responsible for
584 * clearing it.
585 */
b2a6ad87 586 if (imgp->vmspace_destroyed & 2) {
4643740a 587 p->p_flags &= ~P_INEXEC;
b2a6ad87
MD
588 if (p->p_stops)
589 wakeup(&p->p_stype);
590 }
19bfc8ab 591 lwkt_reltoken(&p->p_token);
984263bc 592 if (imgp->vmspace_destroyed) {
5417cd57
SS
593 /*
594 * Sorry, no more process anymore. exit gracefully.
595 * However we can't die right here, because our
596 * caller might have to clean up, so indicate a
90947cb1 597 * lethal error by returning -1.
5417cd57
SS
598 */
599 return(-1);
984263bc
MD
600 } else {
601 return(error);
602 }
603}
604
2bd9d75c
DRJ
605/*
606 * execve() system call.
607 */
608int
753fd850 609sys_execve(struct execve_args *uap)
2bd9d75c 610{
fad57d0e 611 struct nlookupdata nd;
2bd9d75c
DRJ
612 struct image_args args;
613 int error;
614
118cec38 615 bzero(&args, sizeof(args));
3919ced0 616
3919ced0 617 error = nlookup_init(&nd, uap->fname, UIO_USERSPACE, NLC_FOLLOW);
fad57d0e
MD
618 if (error == 0) {
619 error = exec_copyin_args(&args, uap->fname, PATH_USERSPACE,
620 uap->argv, uap->envv);
621 }
2abfe22f
MD
622 if (error == 0)
623 error = kern_execve(&nd, &args);
fad57d0e 624 nlookup_done(&nd);
2bd9d75c
DRJ
625 exec_free_args(&args);
626
5417cd57 627 if (error < 0) {
90947cb1 628 /* We hit a lethal error condition. Let's die now. */
5417cd57
SS
629 exit1(W_EXITCODE(0, SIGABRT));
630 /* NOTREACHED */
631 }
632
2bd9d75c
DRJ
633 /*
634 * The syscall result is returned in registers to the new program.
635 * Linux will register %edx as an atexit function and we must be
636 * sure to set it to 0. XXX
637 */
638 if (error == 0)
639 uap->sysmsg_result64 = 0;
640
641 return (error);
642}
643
984263bc 644int
7c34d798 645exec_map_page(struct image_params *imgp, vm_pindex_t pageno,
5c5185ae 646 struct lwbuf **plwb, const char **pdata)
984263bc 647{
1b9d3514
MD
648 int rv;
649 vm_page_t ma;
06ecca5a 650 vm_page_t m;
984263bc
MD
651 vm_object_t object;
652
fad57d0e 653 /*
7540ab49 654 * The file has to be mappable.
fad57d0e 655 */
7540ab49 656 if ((object = imgp->vp->v_object) == NULL)
fad57d0e 657 return (EIO);
984263bc 658
7c34d798
SS
659 if (pageno >= object->size)
660 return (EIO);
661
501747bf
MD
662 /*
663 * Shortcut using shared locks, improve concurrent execs.
664 */
665 vm_object_hold_shared(object);
666 m = vm_page_lookup(object, pageno);
667 if (m) {
668 if ((m->valid & VM_PAGE_BITS_ALL) == VM_PAGE_BITS_ALL) {
669 vm_page_hold(m);
670 vm_page_sleep_busy(m, FALSE, "execpg");
95d468db
MD
671 if ((m->valid & VM_PAGE_BITS_ALL) == VM_PAGE_BITS_ALL &&
672 m->object == object && m->pindex == pageno) {
501747bf
MD
673 vm_object_drop(object);
674 goto done;
675 }
95d468db 676 vm_page_unhold(m);
501747bf 677 }
501747bf
MD
678 }
679 vm_object_drop(object);
680
681 /*
682 * Do it the hard way
683 */
b12defdc 684 vm_object_hold(object);
7c34d798 685 m = vm_page_grab(object, pageno, VM_ALLOC_NORMAL | VM_ALLOC_RETRY);
1b9d3514
MD
686 while ((m->valid & VM_PAGE_BITS_ALL) != VM_PAGE_BITS_ALL) {
687 ma = m;
984263bc 688
06ecca5a
MD
689 /*
690 * get_pages unbusies all the requested pages except the
a55afca2
MD
691 * primary page (at index 0 in this case). The primary
692 * page may have been wired during the pagein (e.g. by
693 * the buffer cache) so vnode_pager_freepage() must be
694 * used to properly release it.
06ecca5a 695 */
1b9d3514 696 rv = vm_pager_get_page(object, &ma, 1);
7c34d798 697 m = vm_page_lookup(object, pageno);
984263bc 698
06ecca5a
MD
699 if (rv != VM_PAGER_OK || m == NULL || m->valid == 0) {
700 if (m) {
701 vm_page_protect(m, VM_PROT_NONE);
a55afca2 702 vnode_pager_freepage(m);
984263bc 703 }
471bd290 704 vm_object_drop(object);
984263bc
MD
705 return EIO;
706 }
707 }
b12defdc 708 vm_page_hold(m);
06ecca5a 709 vm_page_wakeup(m); /* unbusy the page */
b12defdc 710 vm_object_drop(object);
984263bc 711
501747bf 712done:
7a683a24 713 *plwb = lwbuf_alloc(m, *plwb);
5c5185ae 714 *pdata = (void *)lwbuf_kva(*plwb);
7c34d798
SS
715
716 return (0);
717}
718
7484bdd2
MD
719/*
720 * Map the first page of an executable image.
721 *
722 * NOTE: If the mapping fails we have to NULL-out firstpage which may
723 * still be pointing to our supplied lwp structure.
724 */
7c34d798
SS
725int
726exec_map_first_page(struct image_params *imgp)
727{
728 int err;
729
730 if (imgp->firstpage)
731 exec_unmap_first_page(imgp);
732
7a683a24 733 imgp->firstpage = &imgp->firstpage_cache;
7c34d798
SS
734 err = exec_map_page(imgp, 0, &imgp->firstpage, &imgp->image_header);
735
7484bdd2
MD
736 if (err) {
737 imgp->firstpage = NULL;
7c34d798 738 return err;
7484bdd2 739 }
984263bc
MD
740
741 return 0;
742}
743
744void
5c5185ae 745exec_unmap_page(struct lwbuf *lwb)
984263bc 746{
18f40545
MD
747 vm_page_t m;
748
5fd012e0 749 crit_enter();
5c5185ae
SG
750 if (lwb != NULL) {
751 m = lwbuf_page(lwb);
752 lwbuf_free(lwb);
e4ba7818 753 vm_page_unhold(m);
984263bc 754 }
5fd012e0 755 crit_exit();
984263bc
MD
756}
757
7c34d798
SS
758void
759exec_unmap_first_page(struct image_params *imgp)
760{
761 exec_unmap_page(imgp->firstpage);
762 imgp->firstpage = NULL;
763 imgp->image_header = NULL;
764}
765
984263bc
MD
766/*
767 * Destroy old address space, and allocate a new stack
768 * The new stack is only SGROWSIZ large because it is grown
769 * automatically in trap.c.
dc52e1cc
MD
770 *
771 * This is the point of no return.
984263bc
MD
772 */
773int
29802dbb 774exec_new_vmspace(struct image_params *imgp, struct vmspace *vmcopy)
984263bc 775{
984263bc
MD
776 struct vmspace *vmspace = imgp->proc->p_vmspace;
777 vm_offset_t stack_addr = USRSTACK - maxssiz;
dc52e1cc 778 struct proc *p;
29802dbb 779 vm_map_t map;
dc52e1cc 780 int error;
984263bc 781
dc52e1cc
MD
782 /*
783 * Indicate that we cannot gracefully error out any more, kill
784 * any other threads present, and set P_INEXEC to indicate that
785 * we are now messing with the process structure proper.
786 *
787 * If killalllwps() races return an error which coupled with
788 * vmspace_destroyed will cause us to exit. This is what we
789 * want since another thread is patiently waiting for us to exit
790 * in that case.
791 */
792 p = curproc;
984263bc
MD
793 imgp->vmspace_destroyed = 1;
794
dc52e1cc
MD
795 if (curthread->td_proc->p_nthreads > 1) {
796 error = killalllwps(1);
797 if (error)
798 return (error);
799 }
800 imgp->vmspace_destroyed |= 2; /* we are responsible for P_INEXEC */
4643740a 801 p->p_flags |= P_INEXEC;
08f2f1bb 802
b2a6ad87
MD
803 /*
804 * Tell procfs to release its hold on the process. It
805 * will return EAGAIN.
806 */
807 if (p->p_stops)
808 wakeup(&p->p_stype);
809
82354ad8
MD
810 /*
811 * After setting P_INEXEC wait for any remaining references to
812 * the process (p) to go away.
813 *
814 * In particular, a vfork/exec sequence will replace p->p_vmspace
815 * and we must interlock anyone trying to access the space (aka
816 * procfs or sys_process.c calling procfs_domem()).
817 *
818 * If P_PPWAIT is set the parent vfork()'d and has a PHOLD() on us.
819 */
820 PSTALL(p, "exec1", ((p->p_flags & P_PPWAIT) ? 1 : 0));
821
984263bc
MD
822 /*
823 * Blow away entire process VM, if address space not shared,
824 * otherwise, create a new VM space so that other threads are
29802dbb
MD
825 * not disrupted. If we are execing a resident vmspace we
826 * create a duplicate of it and remap the stack.
984263bc 827 */
29802dbb
MD
828 map = &vmspace->vm_map;
829 if (vmcopy) {
830 vmspace_exec(imgp->proc, vmcopy);
831 vmspace = imgp->proc->p_vmspace;
832 pmap_remove_pages(vmspace_pmap(vmspace), stack_addr, USRSTACK);
833 map = &vmspace->vm_map;
93f86408 834 } else if (vmspace_getrefs(vmspace) == 1) {
fef0fdf2 835 shmexit(vmspace);
88181b08 836 pmap_remove_pages(vmspace_pmap(vmspace),
b0c15cdf 837 0, VM_MAX_USER_ADDRESS);
88181b08 838 vm_map_remove(map, 0, VM_MAX_USER_ADDRESS);
984263bc 839 } else {
29802dbb 840 vmspace_exec(imgp->proc, NULL);
984263bc
MD
841 vmspace = imgp->proc->p_vmspace;
842 map = &vmspace->vm_map;
843 }
844
3e925ec2
MD
845 /*
846 * Allocate a new stack, generally make the stack non-executable
847 * but allow the program to adjust that (the program may desire to
848 * use areas of the stack for executable code).
849 */
984263bc 850 error = vm_map_stack(&vmspace->vm_map, stack_addr, (vm_size_t)maxssiz,
3e925ec2
MD
851 0,
852 VM_PROT_READ|VM_PROT_WRITE,
853 VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE,
854 0);
984263bc
MD
855 if (error)
856 return (error);
857
4b566556
MD
858 /*
859 * vm_ssize and vm_maxsaddr are somewhat antiquated concepts in the
984263bc
MD
860 * VM_STACK case, but they are still used to monitor the size of the
861 * process stack so we can check the stack rlimit.
862 */
4b566556 863 vmspace->vm_ssize = sgrowsiz; /* in bytes */
984263bc
MD
864 vmspace->vm_maxsaddr = (char *)USRSTACK - maxssiz;
865
866 return(0);
867}
868
869/*
870 * Copy out argument and environment strings from the old process
871 * address space into the temporary string buffer.
872 */
873int
2bd9d75c 874exec_copyin_args(struct image_args *args, char *fname,
2abfe22f 875 enum exec_path_segflg segflg, char **argv, char **envv)
984263bc 876{
984263bc 877 char *argp, *envp;
2bd9d75c 878 int error = 0;
984263bc
MD
879 size_t length;
880
18b3f457 881 args->buf = objcache_get(exec_objcache, M_WAITOK);
2bd9d75c
DRJ
882 if (args->buf == NULL)
883 return (ENOMEM);
884 args->begin_argv = args->buf;
885 args->endp = args->begin_argv;
886 args->space = ARG_MAX;
2bd9d75c
DRJ
887
888 args->fname = args->buf + ARG_MAX;
889
984263bc 890 /*
2bd9d75c 891 * Copy the file name.
984263bc 892 */
2bd9d75c
DRJ
893 if (segflg == PATH_SYSSPACE) {
894 error = copystr(fname, args->fname, PATH_MAX, &length);
895 } else if (segflg == PATH_USERSPACE) {
896 error = copyinstr(fname, args->fname, PATH_MAX, &length);
897 }
984263bc 898
2bd9d75c 899 /*
66be6566
MD
900 * Extract argument strings. argv may not be NULL. The argv
901 * array is terminated by a NULL entry. We special-case the
902 * situation where argv[0] is NULL by passing { filename, NULL }
903 * to the new program to guarentee that the interpreter knows what
904 * file to open in case we exec an interpreted file. Note that
905 * a NULL argv[0] terminates the argv[] array.
906 *
907 * XXX the special-casing of argv[0] is historical and needs to be
908 * revisited.
2bd9d75c 909 */
66be6566
MD
910 if (argv == NULL)
911 error = EFAULT;
912 if (error == 0) {
5947157e
MD
913 while ((argp = (caddr_t)(intptr_t)
914 fuword64((uintptr_t *)argv++)) != NULL) {
66be6566 915 if (argp == (caddr_t)-1) {
2bd9d75c 916 error = EFAULT;
66be6566 917 break;
2bd9d75c
DRJ
918 }
919 error = copyinstr(argp, args->endp,
d0e92318 920 args->space, &length);
66be6566
MD
921 if (error) {
922 if (error == ENAMETOOLONG)
923 error = E2BIG;
924 break;
925 }
2bd9d75c
DRJ
926 args->space -= length;
927 args->endp += length;
928 args->argc++;
984263bc 929 }
66be6566
MD
930 if (args->argc == 0 && error == 0) {
931 length = strlen(args->fname) + 1;
932 if (length > args->space) {
933 error = E2BIG;
934 } else {
935 bcopy(args->fname, args->endp, length);
936 args->space -= length;
937 args->endp += length;
938 args->argc++;
939 }
940 }
984263bc
MD
941 }
942
2bd9d75c 943 args->begin_envv = args->endp;
984263bc
MD
944
945 /*
66be6566 946 * extract environment strings. envv may be NULL.
984263bc 947 */
2abfe22f 948 if (envv && error == 0) {
5947157e
MD
949 while ((envp = (caddr_t)(intptr_t)
950 fuword64((uintptr_t *)envv++))) {
2bd9d75c
DRJ
951 if (envp == (caddr_t) -1) {
952 error = EFAULT;
66be6566 953 break;
984263bc 954 }
d0e92318
MD
955 error = copyinstr(envp, args->endp,
956 args->space, &length);
66be6566
MD
957 if (error) {
958 if (error == ENAMETOOLONG)
959 error = E2BIG;
960 break;
961 }
2bd9d75c
DRJ
962 args->space -= length;
963 args->endp += length;
964 args->envc++;
984263bc
MD
965 }
966 }
2bd9d75c
DRJ
967 return (error);
968}
969
970void
971exec_free_args(struct image_args *args)
972{
2abfe22f 973 if (args->buf) {
18b3f457 974 objcache_put(exec_objcache, args->buf);
2abfe22f
MD
975 args->buf = NULL;
976 }
984263bc
MD
977}
978
979/*
980 * Copy strings out to the new process address space, constructing
d0e92318
MD
981 * new arg and env vector tables. Return a pointer to the base
982 * so that it can be used as the initial stack pointer.
983 *
984 * The format is, roughly:
985 *
986 * [argv[]] <-- vectp
987 * [envp[]]
988 * [ELF_Auxargs]
989 *
990 * [args & env] <-- destp
991 * [sgap]
992 * [SPARE_USRSPACE]
993 * [execpath]
3e925ec2
MD
994 * [szsigcode] RO|NX
995 * [ps_strings] RO|NX Top of user stack
d0e92318 996 *
984263bc 997 */
59b728a7 998static register_t *
2bd9d75c 999exec_copyout_strings(struct image_params *imgp)
984263bc 1000{
17a7ca1f 1001 int argc, envc, sgap;
d0e92318
MD
1002 int gap;
1003 int argsenvspace;
984263bc 1004 char **vectp;
3e925ec2 1005 char *stringp, *destp, *szsigbase;
984263bc
MD
1006 register_t *stack_base;
1007 struct ps_strings *arginfo;
adc42cf3 1008 size_t execpath_len;
984263bc
MD
1009 int szsigcode;
1010
1011 /*
1012 * Calculate string base and vector table pointers.
1013 * Also deal with signal trampoline code for this exec type.
1014 */
adc42cf3
JM
1015 if (imgp->execpath != NULL && imgp->auxargs != NULL)
1016 execpath_len = strlen(imgp->execpath) + 1;
1017 else
1018 execpath_len = 0;
984263bc
MD
1019 arginfo = (struct ps_strings *)PS_STRINGS;
1020 szsigcode = *(imgp->proc->p_sysent->sv_szsigcode);
d0e92318
MD
1021
1022 argsenvspace = roundup((ARG_MAX - imgp->args->space), sizeof(char *));
1023 gap = stackgap_random;
1024 cpu_ccfence();
1025 if (gap != 0) {
1026 if (gap < 0)
1027 sgap = ALIGN(-gap);
1028 else
1bd7d69f 1029 sgap = ALIGN(karc4random() & (gap - 1));
d0e92318
MD
1030 } else {
1031 sgap = 0;
1032 }
1033
d0e92318
MD
1034 /*
1035 * Calculate destp, which points to [args & env] and above.
1036 */
da1e1cb6
MD
1037 szsigbase = (char *)(intptr_t)
1038 trunc_page64((intptr_t)arginfo - szsigcode);
1039 szsigbase -= SZSIGCODE_EXTRA_BYTES;
3e925ec2 1040 destp = szsigbase -
d0e92318
MD
1041 roundup(execpath_len, sizeof(char *)) -
1042 SPARE_USRSPACE -
1043 sgap -
1044 argsenvspace;
984263bc
MD
1045
1046 /*
1047 * install sigcode
1048 */
3e925ec2
MD
1049 if (szsigcode)
1050 copyout(imgp->proc->p_sysent->sv_sigcode, szsigbase, szsigcode);
984263bc 1051
adc42cf3
JM
1052 /*
1053 * Copy the image path for the rtld
1054 */
d0e92318 1055 if (execpath_len) {
3e925ec2
MD
1056 imgp->execpathp = (uintptr_t)szsigbase -
1057 roundup(execpath_len, sizeof(char *));
adc42cf3
JM
1058 copyout(imgp->execpath, (void *)imgp->execpathp, execpath_len);
1059 }
1060
984263bc 1061 /*
d0e92318 1062 * Calculate base for argv[], envp[], and ELF_Auxargs.
984263bc 1063 */
d0e92318
MD
1064 vectp = (char **)destp - (AT_COUNT * 2);
1065 vectp -= imgp->args->argc + imgp->args->envc + 2;
984263bc 1066
984263bc
MD
1067 stack_base = (register_t *)vectp;
1068
2bd9d75c
DRJ
1069 stringp = imgp->args->begin_argv;
1070 argc = imgp->args->argc;
1071 envc = imgp->args->envc;
984263bc
MD
1072
1073 /*
d0e92318 1074 * Copy out strings - arguments and environment (at destp)
984263bc 1075 */
2bd9d75c 1076 copyout(stringp, destp, ARG_MAX - imgp->args->space);
984263bc
MD
1077
1078 /*
1079 * Fill in "ps_strings" struct for ps, w, etc.
1080 */
5947157e
MD
1081 suword64((void *)&arginfo->ps_argvstr, (uint64_t)(intptr_t)vectp);
1082 suword32((void *)&arginfo->ps_nargvstr, argc);
984263bc
MD
1083
1084 /*
1085 * Fill in argument portion of vector table.
1086 */
1087 for (; argc > 0; --argc) {
5947157e 1088 suword64((void *)vectp++, (uintptr_t)destp);
984263bc
MD
1089 while (*stringp++ != 0)
1090 destp++;
1091 destp++;
1092 }
1093
7a44d1cb 1094 /* a null vector table pointer separates the argp's from the envp's */
5947157e 1095 suword64((void *)vectp++, 0);
984263bc 1096
5947157e
MD
1097 suword64((void *)&arginfo->ps_envstr, (uintptr_t)vectp);
1098 suword32((void *)&arginfo->ps_nenvstr, envc);
984263bc
MD
1099
1100 /*
1101 * Fill in environment portion of vector table.
1102 */
1103 for (; envc > 0; --envc) {
5947157e 1104 suword64((void *)vectp++, (uintptr_t)destp);
984263bc
MD
1105 while (*stringp++ != 0)
1106 destp++;
1107 destp++;
1108 }
1109
1110 /* end of vector table is a null pointer */
5947157e 1111 suword64((void *)vectp, 0);
984263bc 1112
3e925ec2 1113 /*
11ba7f73 1114 * Make the signal trampoline executable and read-only.
3e925ec2
MD
1115 */
1116 vm_map_protect(&imgp->proc->p_vmspace->vm_map,
1117 (vm_offset_t)szsigbase,
1118 (vm_offset_t)szsigbase + PAGE_SIZE,
11ba7f73 1119 VM_PROT_READ|VM_PROT_EXECUTE, FALSE);
3e925ec2 1120
984263bc
MD
1121 return (stack_base);
1122}
1123
1124/*
1125 * Check permissions of file to execute.
1126 * Return 0 for success or error code on failure.
1127 */
1128int
246693ac 1129exec_check_permissions(struct image_params *imgp, struct mount *topmnt)
984263bc
MD
1130{
1131 struct proc *p = imgp->proc;
1132 struct vnode *vp = imgp->vp;
1133 struct vattr *attr = imgp->attr;
1134 int error;
1135
1136 /* Get file attributes */
87de5057 1137 error = VOP_GETATTR(vp, attr);
984263bc
MD
1138 if (error)
1139 return (error);
1140
1141 /*
1142 * 1) Check if file execution is disabled for the filesystem that this
1143 * file resides on.
1144 * 2) Insure that at least one execute bit is on - otherwise root
1145 * will always succeed, and we don't want to happen unless the
1146 * file really is executable.
1147 * 3) Insure that the file is a regular file.
1148 */
1149 if ((vp->v_mount->mnt_flag & MNT_NOEXEC) ||
246693ac 1150 ((topmnt != NULL) && (topmnt->mnt_flag & MNT_NOEXEC)) ||
984263bc
MD
1151 ((attr->va_mode & 0111) == 0) ||
1152 (attr->va_type != VREG)) {
1153 return (EACCES);
1154 }
1155
1156 /*
1157 * Zero length files can't be exec'd
1158 */
1159 if (attr->va_size == 0)
1160 return (ENOEXEC);
1161
1162 /*
1163 * Check for execute permission to file based on current credentials.
1164 */
90a83564 1165 error = VOP_EACCESS(vp, VEXEC, p->p_ucred);
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1166 if (error)
1167 return (error);
1168
1169 /*
1170 * Check number of open-for-writes on the file and deny execution
1171 * if there are any.
1172 */
1173 if (vp->v_writecount)
1174 return (ETXTBSY);
1175
1176 /*
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1177 * Call filesystem specific open routine, which allows us to read,
1178 * write, and mmap the file. Without the VOP_OPEN we can only
1179 * stat the file.
984263bc 1180 */
87de5057 1181 error = VOP_OPEN(vp, FREAD, p->p_ucred, NULL);
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1182 if (error)
1183 return (error);
1184
1185 return (0);
1186}
1187
1188/*
1189 * Exec handler registration
1190 */
1191int
77153250 1192exec_register(const struct execsw *execsw_arg)
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1193{
1194 const struct execsw **es, **xs, **newexecsw;
1195 int count = 2; /* New slot and trailing NULL */
1196
1197 if (execsw)
1198 for (es = execsw; *es; es++)
1199 count++;
efda3bd0 1200 newexecsw = kmalloc(count * sizeof(*es), M_TEMP, M_WAITOK);
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1201 xs = newexecsw;
1202 if (execsw)
1203 for (es = execsw; *es; es++)
1204 *xs++ = *es;
1205 *xs++ = execsw_arg;
1206 *xs = NULL;
1207 if (execsw)
efda3bd0 1208 kfree(execsw, M_TEMP);
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1209 execsw = newexecsw;
1210 return 0;
1211}
1212
1213int
77153250 1214exec_unregister(const struct execsw *execsw_arg)
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1215{
1216 const struct execsw **es, **xs, **newexecsw;
1217 int count = 1;
1218
1219 if (execsw == NULL)
ae7e74d4 1220 panic("unregister with no handlers left?");
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1221
1222 for (es = execsw; *es; es++) {
1223 if (*es == execsw_arg)
1224 break;
1225 }
1226 if (*es == NULL)
1227 return ENOENT;
1228 for (es = execsw; *es; es++)
1229 if (*es != execsw_arg)
1230 count++;
efda3bd0 1231 newexecsw = kmalloc(count * sizeof(*es), M_TEMP, M_WAITOK);
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1232 xs = newexecsw;
1233 for (es = execsw; *es; es++)
1234 if (*es != execsw_arg)
1235 *xs++ = *es;
1236 *xs = NULL;
1237 if (execsw)
efda3bd0 1238 kfree(execsw, M_TEMP);
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1239 execsw = newexecsw;
1240 return 0;
1241}