kern_exec.c revision 1.362 1 /* $NetBSD: kern_exec.c,v 1.362 2013/09/10 21:30:21 matt Exp $ */
2
3 /*-
4 * Copyright (c) 2008 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
17 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
18 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
19 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
20 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26 * POSSIBILITY OF SUCH DAMAGE.
27 */
28
29 /*-
30 * Copyright (C) 1993, 1994, 1996 Christopher G. Demetriou
31 * Copyright (C) 1992 Wolfgang Solfrank.
32 * Copyright (C) 1992 TooLs GmbH.
33 * All rights reserved.
34 *
35 * Redistribution and use in source and binary forms, with or without
36 * modification, are permitted provided that the following conditions
37 * are met:
38 * 1. Redistributions of source code must retain the above copyright
39 * notice, this list of conditions and the following disclaimer.
40 * 2. Redistributions in binary form must reproduce the above copyright
41 * notice, this list of conditions and the following disclaimer in the
42 * documentation and/or other materials provided with the distribution.
43 * 3. All advertising materials mentioning features or use of this software
44 * must display the following acknowledgement:
45 * This product includes software developed by TooLs GmbH.
46 * 4. The name of TooLs GmbH may not be used to endorse or promote products
47 * derived from this software without specific prior written permission.
48 *
49 * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
50 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
51 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
52 * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
53 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
54 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
55 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
56 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
57 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
58 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
59 */
60
61 #include <sys/cdefs.h>
62 __KERNEL_RCSID(0, "$NetBSD: kern_exec.c,v 1.362 2013/09/10 21:30:21 matt Exp $");
63
64 #include "opt_exec.h"
65 #include "opt_execfmt.h"
66 #include "opt_ktrace.h"
67 #include "opt_modular.h"
68 #include "opt_syscall_debug.h"
69 #include "veriexec.h"
70 #include "opt_pax.h"
71
72 #include <sys/param.h>
73 #include <sys/systm.h>
74 #include <sys/filedesc.h>
75 #include <sys/kernel.h>
76 #include <sys/proc.h>
77 #include <sys/mount.h>
78 #include <sys/malloc.h>
79 #include <sys/kmem.h>
80 #include <sys/namei.h>
81 #include <sys/vnode.h>
82 #include <sys/file.h>
83 #include <sys/acct.h>
84 #include <sys/atomic.h>
85 #include <sys/exec.h>
86 #include <sys/ktrace.h>
87 #include <sys/uidinfo.h>
88 #include <sys/wait.h>
89 #include <sys/mman.h>
90 #include <sys/ras.h>
91 #include <sys/signalvar.h>
92 #include <sys/stat.h>
93 #include <sys/syscall.h>
94 #include <sys/kauth.h>
95 #include <sys/lwpctl.h>
96 #include <sys/pax.h>
97 #include <sys/cpu.h>
98 #include <sys/module.h>
99 #include <sys/syscallvar.h>
100 #include <sys/syscallargs.h>
101 #if NVERIEXEC > 0
102 #include <sys/verified_exec.h>
103 #endif /* NVERIEXEC > 0 */
104 #include <sys/sdt.h>
105 #include <sys/spawn.h>
106 #include <sys/prot.h>
107 #include <sys/cprng.h>
108
109 #include <uvm/uvm_extern.h>
110
111 #include <machine/reg.h>
112
113 #include <compat/common/compat_util.h>
114
115 static int exec_sigcode_map(struct proc *, const struct emul *);
116
117 #ifdef DEBUG_EXEC
118 #define DPRINTF(a) printf a
119 #define COPYPRINTF(s, a, b) printf("%s, %d: copyout%s @%p %zu\n", __func__, \
120 __LINE__, (s), (a), (b))
121 #else
122 #define DPRINTF(a)
123 #define COPYPRINTF(s, a, b)
124 #endif /* DEBUG_EXEC */
125
126 /*
127 * DTrace SDT provider definitions
128 */
129 SDT_PROBE_DEFINE(proc,,,exec,exec,
130 "char *", NULL,
131 NULL, NULL, NULL, NULL,
132 NULL, NULL, NULL, NULL);
133 SDT_PROBE_DEFINE(proc,,,exec_success,exec-success,
134 "char *", NULL,
135 NULL, NULL, NULL, NULL,
136 NULL, NULL, NULL, NULL);
137 SDT_PROBE_DEFINE(proc,,,exec_failure,exec-failure,
138 "int", NULL,
139 NULL, NULL, NULL, NULL,
140 NULL, NULL, NULL, NULL);
141
142 /*
143 * Exec function switch:
144 *
145 * Note that each makecmds function is responsible for loading the
146 * exec package with the necessary functions for any exec-type-specific
147 * handling.
148 *
149 * Functions for specific exec types should be defined in their own
150 * header file.
151 */
152 static const struct execsw **execsw = NULL;
153 static int nexecs;
154
155 u_int exec_maxhdrsz; /* must not be static - used by netbsd32 */
156
157 /* list of dynamically loaded execsw entries */
158 static LIST_HEAD(execlist_head, exec_entry) ex_head =
159 LIST_HEAD_INITIALIZER(ex_head);
160 struct exec_entry {
161 LIST_ENTRY(exec_entry) ex_list;
162 SLIST_ENTRY(exec_entry) ex_slist;
163 const struct execsw *ex_sw;
164 };
165
166 #ifndef __HAVE_SYSCALL_INTERN
167 void syscall(void);
168 #endif
169
170 /* NetBSD emul struct */
171 struct emul emul_netbsd = {
172 .e_name = "netbsd",
173 .e_path = NULL,
174 #ifndef __HAVE_MINIMAL_EMUL
175 .e_flags = EMUL_HAS_SYS___syscall,
176 .e_errno = NULL,
177 .e_nosys = SYS_syscall,
178 .e_nsysent = SYS_NSYSENT,
179 #endif
180 .e_sysent = sysent,
181 #ifdef SYSCALL_DEBUG
182 .e_syscallnames = syscallnames,
183 #else
184 .e_syscallnames = NULL,
185 #endif
186 .e_sendsig = sendsig,
187 .e_trapsignal = trapsignal,
188 .e_tracesig = NULL,
189 .e_sigcode = NULL,
190 .e_esigcode = NULL,
191 .e_sigobject = NULL,
192 .e_setregs = setregs,
193 .e_proc_exec = NULL,
194 .e_proc_fork = NULL,
195 .e_proc_exit = NULL,
196 .e_lwp_fork = NULL,
197 .e_lwp_exit = NULL,
198 #ifdef __HAVE_SYSCALL_INTERN
199 .e_syscall_intern = syscall_intern,
200 #else
201 .e_syscall = syscall,
202 #endif
203 .e_sysctlovly = NULL,
204 .e_fault = NULL,
205 .e_vm_default_addr = uvm_default_mapaddr,
206 .e_usertrap = NULL,
207 .e_ucsize = sizeof(ucontext_t),
208 .e_startlwp = startlwp
209 };
210
211 /*
212 * Exec lock. Used to control access to execsw[] structures.
213 * This must not be static so that netbsd32 can access it, too.
214 */
215 krwlock_t exec_lock;
216
217 static kmutex_t sigobject_lock;
218
219 /*
220 * Data used between a loadvm and execve part of an "exec" operation
221 */
222 struct execve_data {
223 struct exec_package ed_pack;
224 struct pathbuf *ed_pathbuf;
225 struct vattr ed_attr;
226 struct ps_strings ed_arginfo;
227 char *ed_argp;
228 const char *ed_pathstring;
229 char *ed_resolvedpathbuf;
230 size_t ed_ps_strings_sz;
231 int ed_szsigcode;
232 long ed_argc;
233 long ed_envc;
234 };
235
236 /*
237 * data passed from parent lwp to child during a posix_spawn()
238 */
239 struct spawn_exec_data {
240 struct execve_data sed_exec;
241 struct posix_spawn_file_actions
242 *sed_actions;
243 struct posix_spawnattr *sed_attrs;
244 struct proc *sed_parent;
245 kcondvar_t sed_cv_child_ready;
246 kmutex_t sed_mtx_child;
247 int sed_error;
248 volatile uint32_t sed_refcnt;
249 };
250
251 static void *
252 exec_pool_alloc(struct pool *pp, int flags)
253 {
254
255 return (void *)uvm_km_alloc(kernel_map, NCARGS, 0,
256 UVM_KMF_PAGEABLE | UVM_KMF_WAITVA);
257 }
258
259 static void
260 exec_pool_free(struct pool *pp, void *addr)
261 {
262
263 uvm_km_free(kernel_map, (vaddr_t)addr, NCARGS, UVM_KMF_PAGEABLE);
264 }
265
266 static struct pool exec_pool;
267
268 static struct pool_allocator exec_palloc = {
269 .pa_alloc = exec_pool_alloc,
270 .pa_free = exec_pool_free,
271 .pa_pagesz = NCARGS
272 };
273
274 /*
275 * check exec:
276 * given an "executable" described in the exec package's namei info,
277 * see what we can do with it.
278 *
279 * ON ENTRY:
280 * exec package with appropriate namei info
281 * lwp pointer of exec'ing lwp
282 * NO SELF-LOCKED VNODES
283 *
284 * ON EXIT:
285 * error: nothing held, etc. exec header still allocated.
286 * ok: filled exec package, executable's vnode (unlocked).
287 *
288 * EXEC SWITCH ENTRY:
289 * Locked vnode to check, exec package, proc.
290 *
291 * EXEC SWITCH EXIT:
292 * ok: return 0, filled exec package, executable's vnode (unlocked).
293 * error: destructive:
294 * everything deallocated execept exec header.
295 * non-destructive:
296 * error code, executable's vnode (unlocked),
297 * exec header unmodified.
298 */
299 int
300 /*ARGSUSED*/
301 check_exec(struct lwp *l, struct exec_package *epp, struct pathbuf *pb)
302 {
303 int error, i;
304 struct vnode *vp;
305 struct nameidata nd;
306 size_t resid;
307
308 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF | TRYEMULROOT, pb);
309
310 /* first get the vnode */
311 if ((error = namei(&nd)) != 0)
312 return error;
313 epp->ep_vp = vp = nd.ni_vp;
314 /* this cannot overflow as both are size PATH_MAX */
315 strcpy(epp->ep_resolvedname, nd.ni_pnbuf);
316
317 #ifdef DIAGNOSTIC
318 /* paranoia (take this out once namei stuff stabilizes) */
319 memset(nd.ni_pnbuf, '~', PATH_MAX);
320 #endif
321
322 /* check access and type */
323 if (vp->v_type != VREG) {
324 error = EACCES;
325 goto bad1;
326 }
327 if ((error = VOP_ACCESS(vp, VEXEC, l->l_cred)) != 0)
328 goto bad1;
329
330 /* get attributes */
331 if ((error = VOP_GETATTR(vp, epp->ep_vap, l->l_cred)) != 0)
332 goto bad1;
333
334 /* Check mount point */
335 if (vp->v_mount->mnt_flag & MNT_NOEXEC) {
336 error = EACCES;
337 goto bad1;
338 }
339 if (vp->v_mount->mnt_flag & MNT_NOSUID)
340 epp->ep_vap->va_mode &= ~(S_ISUID | S_ISGID);
341
342 /* try to open it */
343 if ((error = VOP_OPEN(vp, FREAD, l->l_cred)) != 0)
344 goto bad1;
345
346 /* unlock vp, since we need it unlocked from here on out. */
347 VOP_UNLOCK(vp);
348
349 #if NVERIEXEC > 0
350 error = veriexec_verify(l, vp, epp->ep_resolvedname,
351 epp->ep_flags & EXEC_INDIR ? VERIEXEC_INDIRECT : VERIEXEC_DIRECT,
352 NULL);
353 if (error)
354 goto bad2;
355 #endif /* NVERIEXEC > 0 */
356
357 #ifdef PAX_SEGVGUARD
358 error = pax_segvguard(l, vp, epp->ep_resolvedname, false);
359 if (error)
360 goto bad2;
361 #endif /* PAX_SEGVGUARD */
362
363 /* now we have the file, get the exec header */
364 error = vn_rdwr(UIO_READ, vp, epp->ep_hdr, epp->ep_hdrlen, 0,
365 UIO_SYSSPACE, 0, l->l_cred, &resid, NULL);
366 if (error)
367 goto bad2;
368 epp->ep_hdrvalid = epp->ep_hdrlen - resid;
369
370 /*
371 * Set up default address space limits. Can be overridden
372 * by individual exec packages.
373 *
374 * XXX probably should be all done in the exec packages.
375 */
376 epp->ep_vm_minaddr = VM_MIN_ADDRESS;
377 epp->ep_vm_maxaddr = VM_MAXUSER_ADDRESS;
378 /*
379 * set up the vmcmds for creation of the process
380 * address space
381 */
382 error = ENOEXEC;
383 for (i = 0; i < nexecs; i++) {
384 int newerror;
385
386 epp->ep_esch = execsw[i];
387 newerror = (*execsw[i]->es_makecmds)(l, epp);
388
389 if (!newerror) {
390 /* Seems ok: check that entry point is not too high */
391 if (epp->ep_entry > epp->ep_vm_maxaddr) {
392 #ifdef DIAGNOSTIC
393 printf("%s: rejecting %p due to "
394 "too high entry address (> %p)\n",
395 __func__, (void *)epp->ep_entry,
396 (void *)epp->ep_vm_maxaddr);
397 #endif
398 error = ENOEXEC;
399 break;
400 }
401 /* Seems ok: check that entry point is not too low */
402 if (epp->ep_entry < epp->ep_vm_minaddr) {
403 #ifdef DIAGNOSTIC
404 printf("%s: rejecting %p due to "
405 "too low entry address (< %p)\n",
406 __func__, (void *)epp->ep_entry,
407 (void *)epp->ep_vm_minaddr);
408 #endif
409 error = ENOEXEC;
410 break;
411 }
412
413 /* check limits */
414 if ((epp->ep_tsize > MAXTSIZ) ||
415 (epp->ep_dsize > (u_quad_t)l->l_proc->p_rlimit
416 [RLIMIT_DATA].rlim_cur)) {
417 #ifdef DIAGNOSTIC
418 printf("%s: rejecting due to "
419 "limits (t=%llu > %llu || d=%llu > %llu)\n",
420 __func__,
421 (unsigned long long)epp->ep_tsize,
422 (unsigned long long)MAXTSIZ,
423 (unsigned long long)epp->ep_dsize,
424 (unsigned long long)
425 l->l_proc->p_rlimit[RLIMIT_DATA].rlim_cur);
426 #endif
427 error = ENOMEM;
428 break;
429 }
430 return 0;
431 }
432
433 if (epp->ep_emul_root != NULL) {
434 vrele(epp->ep_emul_root);
435 epp->ep_emul_root = NULL;
436 }
437 if (epp->ep_interp != NULL) {
438 vrele(epp->ep_interp);
439 epp->ep_interp = NULL;
440 }
441
442 /* make sure the first "interesting" error code is saved. */
443 if (error == ENOEXEC)
444 error = newerror;
445
446 if (epp->ep_flags & EXEC_DESTR)
447 /* Error from "#!" code, tidied up by recursive call */
448 return error;
449 }
450
451 /* not found, error */
452
453 /*
454 * free any vmspace-creation commands,
455 * and release their references
456 */
457 kill_vmcmds(&epp->ep_vmcmds);
458
459 bad2:
460 /*
461 * close and release the vnode, restore the old one, free the
462 * pathname buf, and punt.
463 */
464 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
465 VOP_CLOSE(vp, FREAD, l->l_cred);
466 vput(vp);
467 return error;
468
469 bad1:
470 /*
471 * free the namei pathname buffer, and put the vnode
472 * (which we don't yet have open).
473 */
474 vput(vp); /* was still locked */
475 return error;
476 }
477
478 #ifdef __MACHINE_STACK_GROWS_UP
479 #define STACK_PTHREADSPACE NBPG
480 #else
481 #define STACK_PTHREADSPACE 0
482 #endif
483
484 static int
485 execve_fetch_element(char * const *array, size_t index, char **value)
486 {
487 return copyin(array + index, value, sizeof(*value));
488 }
489
490 /*
491 * exec system call
492 */
493 int
494 sys_execve(struct lwp *l, const struct sys_execve_args *uap, register_t *retval)
495 {
496 /* {
497 syscallarg(const char *) path;
498 syscallarg(char * const *) argp;
499 syscallarg(char * const *) envp;
500 } */
501
502 return execve1(l, SCARG(uap, path), SCARG(uap, argp),
503 SCARG(uap, envp), execve_fetch_element);
504 }
505
506 int
507 sys_fexecve(struct lwp *l, const struct sys_fexecve_args *uap,
508 register_t *retval)
509 {
510 /* {
511 syscallarg(int) fd;
512 syscallarg(char * const *) argp;
513 syscallarg(char * const *) envp;
514 } */
515
516 return ENOSYS;
517 }
518
519 /*
520 * Load modules to try and execute an image that we do not understand.
521 * If no execsw entries are present, we load those likely to be needed
522 * in order to run native images only. Otherwise, we autoload all
523 * possible modules that could let us run the binary. XXX lame
524 */
525 static void
526 exec_autoload(void)
527 {
528 #ifdef MODULAR
529 static const char * const native[] = {
530 "exec_elf32",
531 "exec_elf64",
532 "exec_script",
533 NULL
534 };
535 static const char * const compat[] = {
536 "exec_elf32",
537 "exec_elf64",
538 "exec_script",
539 "exec_aout",
540 "exec_coff",
541 "exec_ecoff",
542 "compat_aoutm68k",
543 "compat_freebsd",
544 "compat_ibcs2",
545 "compat_linux",
546 "compat_linux32",
547 "compat_netbsd32",
548 "compat_sunos",
549 "compat_sunos32",
550 "compat_svr4",
551 "compat_svr4_32",
552 "compat_ultrix",
553 NULL
554 };
555 char const * const *list;
556 int i;
557
558 list = (nexecs == 0 ? native : compat);
559 for (i = 0; list[i] != NULL; i++) {
560 if (module_autoload(list[i], MODULE_CLASS_MISC) != 0) {
561 continue;
562 }
563 yield();
564 }
565 #endif
566 }
567
568 static int
569 execve_loadvm(struct lwp *l, const char *path, char * const *args,
570 char * const *envs, execve_fetch_element_t fetch_element,
571 struct execve_data * restrict data)
572 {
573 int error;
574 struct proc *p;
575 char *dp, *sp;
576 size_t i, len;
577 struct exec_fakearg *tmpfap;
578 u_int modgen;
579
580 KASSERT(data != NULL);
581
582 p = l->l_proc;
583 modgen = 0;
584
585 SDT_PROBE(proc,,,exec, path, 0, 0, 0, 0);
586
587 /*
588 * Check if we have exceeded our number of processes limit.
589 * This is so that we handle the case where a root daemon
590 * forked, ran setuid to become the desired user and is trying
591 * to exec. The obvious place to do the reference counting check
592 * is setuid(), but we don't do the reference counting check there
593 * like other OS's do because then all the programs that use setuid()
594 * must be modified to check the return code of setuid() and exit().
595 * It is dangerous to make setuid() fail, because it fails open and
596 * the program will continue to run as root. If we make it succeed
597 * and return an error code, again we are not enforcing the limit.
598 * The best place to enforce the limit is here, when the process tries
599 * to execute a new image, because eventually the process will need
600 * to call exec in order to do something useful.
601 */
602 retry:
603 if (p->p_flag & PK_SUGID) {
604 if (kauth_authorize_process(l->l_cred, KAUTH_PROCESS_RLIMIT,
605 p, KAUTH_ARG(KAUTH_REQ_PROCESS_RLIMIT_BYPASS),
606 &p->p_rlimit[RLIMIT_NPROC],
607 KAUTH_ARG(RLIMIT_NPROC)) != 0 &&
608 chgproccnt(kauth_cred_getuid(l->l_cred), 0) >
609 p->p_rlimit[RLIMIT_NPROC].rlim_cur)
610 return EAGAIN;
611 }
612
613 /*
614 * Drain existing references and forbid new ones. The process
615 * should be left alone until we're done here. This is necessary
616 * to avoid race conditions - e.g. in ptrace() - that might allow
617 * a local user to illicitly obtain elevated privileges.
618 */
619 rw_enter(&p->p_reflock, RW_WRITER);
620
621 /*
622 * Init the namei data to point the file user's program name.
623 * This is done here rather than in check_exec(), so that it's
624 * possible to override this settings if any of makecmd/probe
625 * functions call check_exec() recursively - for example,
626 * see exec_script_makecmds().
627 */
628 error = pathbuf_copyin(path, &data->ed_pathbuf);
629 if (error) {
630 DPRINTF(("%s: pathbuf_copyin path @%p %d\n", __func__,
631 path, error));
632 goto clrflg;
633 }
634 data->ed_pathstring = pathbuf_stringcopy_get(data->ed_pathbuf);
635
636 data->ed_resolvedpathbuf = PNBUF_GET();
637 #ifdef DIAGNOSTIC
638 strcpy(data->ed_resolvedpathbuf, "/wrong");
639 #endif
640
641 /*
642 * initialize the fields of the exec package.
643 */
644 data->ed_pack.ep_name = path;
645 data->ed_pack.ep_kname = data->ed_pathstring;
646 data->ed_pack.ep_resolvedname = data->ed_resolvedpathbuf;
647 data->ed_pack.ep_hdr = kmem_alloc(exec_maxhdrsz, KM_SLEEP);
648 data->ed_pack.ep_hdrlen = exec_maxhdrsz;
649 data->ed_pack.ep_hdrvalid = 0;
650 data->ed_pack.ep_emul_arg = NULL;
651 data->ed_pack.ep_emul_arg_free = NULL;
652 data->ed_pack.ep_vmcmds.evs_cnt = 0;
653 data->ed_pack.ep_vmcmds.evs_used = 0;
654 data->ed_pack.ep_vap = &data->ed_attr;
655 data->ed_pack.ep_flags = 0;
656 data->ed_pack.ep_emul_root = NULL;
657 data->ed_pack.ep_interp = NULL;
658 data->ed_pack.ep_esch = NULL;
659 data->ed_pack.ep_pax_flags = 0;
660 memset(data->ed_pack.ep_machine_arch, 0,
661 sizeof(data->ed_pack.ep_machine_arch));
662
663 rw_enter(&exec_lock, RW_READER);
664
665 /* see if we can run it. */
666 if ((error = check_exec(l, &data->ed_pack, data->ed_pathbuf)) != 0) {
667 if (error != ENOENT) {
668 DPRINTF(("%s: check exec failed %d\n",
669 __func__, error));
670 }
671 goto freehdr;
672 }
673
674 /* XXX -- THE FOLLOWING SECTION NEEDS MAJOR CLEANUP */
675
676 /* allocate an argument buffer */
677 data->ed_argp = pool_get(&exec_pool, PR_WAITOK);
678 KASSERT(data->ed_argp != NULL);
679 dp = data->ed_argp;
680 data->ed_argc = 0;
681
682 /* copy the fake args list, if there's one, freeing it as we go */
683 if (data->ed_pack.ep_flags & EXEC_HASARGL) {
684 tmpfap = data->ed_pack.ep_fa;
685 while (tmpfap->fa_arg != NULL) {
686 const char *cp;
687
688 cp = tmpfap->fa_arg;
689 while (*cp)
690 *dp++ = *cp++;
691 *dp++ = '\0';
692 ktrexecarg(tmpfap->fa_arg, cp - tmpfap->fa_arg);
693
694 kmem_free(tmpfap->fa_arg, tmpfap->fa_len);
695 tmpfap++; data->ed_argc++;
696 }
697 kmem_free(data->ed_pack.ep_fa, data->ed_pack.ep_fa_len);
698 data->ed_pack.ep_flags &= ~EXEC_HASARGL;
699 }
700
701 /* Now get argv & environment */
702 if (args == NULL) {
703 DPRINTF(("%s: null args\n", __func__));
704 error = EINVAL;
705 goto bad;
706 }
707 /* 'i' will index the argp/envp element to be retrieved */
708 i = 0;
709 if (data->ed_pack.ep_flags & EXEC_SKIPARG)
710 i++;
711
712 while (1) {
713 len = data->ed_argp + ARG_MAX - dp;
714 if ((error = (*fetch_element)(args, i, &sp)) != 0) {
715 DPRINTF(("%s: fetch_element args %d\n",
716 __func__, error));
717 goto bad;
718 }
719 if (!sp)
720 break;
721 if ((error = copyinstr(sp, dp, len, &len)) != 0) {
722 DPRINTF(("%s: copyinstr args %d\n", __func__, error));
723 if (error == ENAMETOOLONG)
724 error = E2BIG;
725 goto bad;
726 }
727 ktrexecarg(dp, len - 1);
728 dp += len;
729 i++;
730 data->ed_argc++;
731 }
732
733 data->ed_envc = 0;
734 /* environment need not be there */
735 if (envs != NULL) {
736 i = 0;
737 while (1) {
738 len = data->ed_argp + ARG_MAX - dp;
739 if ((error = (*fetch_element)(envs, i, &sp)) != 0) {
740 DPRINTF(("%s: fetch_element env %d\n",
741 __func__, error));
742 goto bad;
743 }
744 if (!sp)
745 break;
746 if ((error = copyinstr(sp, dp, len, &len)) != 0) {
747 DPRINTF(("%s: copyinstr env %d\n",
748 __func__, error));
749 if (error == ENAMETOOLONG)
750 error = E2BIG;
751 goto bad;
752 }
753
754 ktrexecenv(dp, len - 1);
755 dp += len;
756 i++;
757 data->ed_envc++;
758 }
759 }
760
761 dp = (char *) ALIGN(dp);
762
763 data->ed_szsigcode = data->ed_pack.ep_esch->es_emul->e_esigcode -
764 data->ed_pack.ep_esch->es_emul->e_sigcode;
765
766 #ifdef __MACHINE_STACK_GROWS_UP
767 /* See big comment lower down */
768 #define RTLD_GAP 32
769 #else
770 #define RTLD_GAP 0
771 #endif
772
773 /* Now check if args & environ fit into new stack */
774 if (data->ed_pack.ep_flags & EXEC_32) {
775 data->ed_ps_strings_sz = sizeof(struct ps_strings32);
776 len = ((data->ed_argc + data->ed_envc + 2 +
777 data->ed_pack.ep_esch->es_arglen) *
778 sizeof(int) + sizeof(int) + dp + RTLD_GAP +
779 data->ed_szsigcode + data->ed_ps_strings_sz + STACK_PTHREADSPACE)
780 - data->ed_argp;
781 } else {
782 data->ed_ps_strings_sz = sizeof(struct ps_strings);
783 len = ((data->ed_argc + data->ed_envc + 2 +
784 data->ed_pack.ep_esch->es_arglen) *
785 sizeof(char *) + sizeof(int) + dp + RTLD_GAP +
786 data->ed_szsigcode + data->ed_ps_strings_sz + STACK_PTHREADSPACE)
787 - data->ed_argp;
788 }
789
790 #ifdef PAX_ASLR
791 if (pax_aslr_active(l))
792 len += (cprng_fast32() % PAGE_SIZE);
793 #endif /* PAX_ASLR */
794
795 /* make the stack "safely" aligned */
796 len = STACK_LEN_ALIGN(len, STACK_ALIGNBYTES);
797
798 if (len > data->ed_pack.ep_ssize) {
799 /* in effect, compare to initial limit */
800 DPRINTF(("%s: stack limit exceeded %zu\n", __func__, len));
801 goto bad;
802 }
803 /* adjust "active stack depth" for process VSZ */
804 data->ed_pack.ep_ssize = len;
805
806 return 0;
807
808 bad:
809 /* free the vmspace-creation commands, and release their references */
810 kill_vmcmds(&data->ed_pack.ep_vmcmds);
811 /* kill any opened file descriptor, if necessary */
812 if (data->ed_pack.ep_flags & EXEC_HASFD) {
813 data->ed_pack.ep_flags &= ~EXEC_HASFD;
814 fd_close(data->ed_pack.ep_fd);
815 }
816 /* close and put the exec'd file */
817 vn_lock(data->ed_pack.ep_vp, LK_EXCLUSIVE | LK_RETRY);
818 VOP_CLOSE(data->ed_pack.ep_vp, FREAD, l->l_cred);
819 vput(data->ed_pack.ep_vp);
820 pool_put(&exec_pool, data->ed_argp);
821
822 freehdr:
823 kmem_free(data->ed_pack.ep_hdr, data->ed_pack.ep_hdrlen);
824 if (data->ed_pack.ep_emul_root != NULL)
825 vrele(data->ed_pack.ep_emul_root);
826 if (data->ed_pack.ep_interp != NULL)
827 vrele(data->ed_pack.ep_interp);
828
829 rw_exit(&exec_lock);
830
831 pathbuf_stringcopy_put(data->ed_pathbuf, data->ed_pathstring);
832 pathbuf_destroy(data->ed_pathbuf);
833 PNBUF_PUT(data->ed_resolvedpathbuf);
834
835 clrflg:
836 rw_exit(&p->p_reflock);
837
838 if (modgen != module_gen && error == ENOEXEC) {
839 modgen = module_gen;
840 exec_autoload();
841 goto retry;
842 }
843
844 SDT_PROBE(proc,,,exec_failure, error, 0, 0, 0, 0);
845 return error;
846 }
847
848 static void
849 execve_free_data(struct execve_data *data)
850 {
851
852 /* free the vmspace-creation commands, and release their references */
853 kill_vmcmds(&data->ed_pack.ep_vmcmds);
854 /* kill any opened file descriptor, if necessary */
855 if (data->ed_pack.ep_flags & EXEC_HASFD) {
856 data->ed_pack.ep_flags &= ~EXEC_HASFD;
857 fd_close(data->ed_pack.ep_fd);
858 }
859
860 /* close and put the exec'd file */
861 vn_lock(data->ed_pack.ep_vp, LK_EXCLUSIVE | LK_RETRY);
862 VOP_CLOSE(data->ed_pack.ep_vp, FREAD, curlwp->l_cred);
863 vput(data->ed_pack.ep_vp);
864 pool_put(&exec_pool, data->ed_argp);
865
866 kmem_free(data->ed_pack.ep_hdr, data->ed_pack.ep_hdrlen);
867 if (data->ed_pack.ep_emul_root != NULL)
868 vrele(data->ed_pack.ep_emul_root);
869 if (data->ed_pack.ep_interp != NULL)
870 vrele(data->ed_pack.ep_interp);
871
872 pathbuf_stringcopy_put(data->ed_pathbuf, data->ed_pathstring);
873 pathbuf_destroy(data->ed_pathbuf);
874 PNBUF_PUT(data->ed_resolvedpathbuf);
875 }
876
877 static int
878 execve_runproc(struct lwp *l, struct execve_data * restrict data,
879 bool no_local_exec_lock, bool is_spawn)
880 {
881 int error = 0;
882 struct proc *p;
883 size_t i;
884 char *stack, *dp;
885 const char *commandname;
886 struct ps_strings32 arginfo32;
887 struct exec_vmcmd *base_vcp;
888 void *aip;
889 struct vmspace *vm;
890 ksiginfo_t ksi;
891 ksiginfoq_t kq;
892
893 /*
894 * In case of a posix_spawn operation, the child doing the exec
895 * might not hold the reader lock on exec_lock, but the parent
896 * will do this instead.
897 */
898 KASSERT(no_local_exec_lock || rw_lock_held(&exec_lock));
899 KASSERT(data != NULL);
900 if (data == NULL)
901 return (EINVAL);
902
903 p = l->l_proc;
904 if (no_local_exec_lock)
905 KASSERT(is_spawn);
906
907 base_vcp = NULL;
908
909 if (data->ed_pack.ep_flags & EXEC_32)
910 aip = &arginfo32;
911 else
912 aip = &data->ed_arginfo;
913
914 /* Get rid of other LWPs. */
915 if (p->p_nlwps > 1) {
916 mutex_enter(p->p_lock);
917 exit_lwps(l);
918 mutex_exit(p->p_lock);
919 }
920 KDASSERT(p->p_nlwps == 1);
921
922 /* Destroy any lwpctl info. */
923 if (p->p_lwpctl != NULL)
924 lwp_ctl_exit();
925
926 /* Remove POSIX timers */
927 timers_free(p, TIMERS_POSIX);
928
929 /*
930 * Do whatever is necessary to prepare the address space
931 * for remapping. Note that this might replace the current
932 * vmspace with another!
933 */
934 if (is_spawn)
935 uvmspace_spawn(l, data->ed_pack.ep_vm_minaddr,
936 data->ed_pack.ep_vm_maxaddr);
937 else
938 uvmspace_exec(l, data->ed_pack.ep_vm_minaddr,
939 data->ed_pack.ep_vm_maxaddr);
940
941 /* record proc's vnode, for use by procfs and others */
942 if (p->p_textvp)
943 vrele(p->p_textvp);
944 vref(data->ed_pack.ep_vp);
945 p->p_textvp = data->ed_pack.ep_vp;
946
947 /* Now map address space */
948 vm = p->p_vmspace;
949 vm->vm_taddr = (void *)data->ed_pack.ep_taddr;
950 vm->vm_tsize = btoc(data->ed_pack.ep_tsize);
951 vm->vm_daddr = (void*)data->ed_pack.ep_daddr;
952 vm->vm_dsize = btoc(data->ed_pack.ep_dsize);
953 vm->vm_ssize = btoc(data->ed_pack.ep_ssize);
954 vm->vm_issize = 0;
955 vm->vm_maxsaddr = (void *)data->ed_pack.ep_maxsaddr;
956 vm->vm_minsaddr = (void *)data->ed_pack.ep_minsaddr;
957
958 #ifdef PAX_ASLR
959 pax_aslr_init(l, vm);
960 #endif /* PAX_ASLR */
961
962 /* create the new process's VM space by running the vmcmds */
963 #ifdef DIAGNOSTIC
964 if (data->ed_pack.ep_vmcmds.evs_used == 0)
965 panic("%s: no vmcmds", __func__);
966 #endif
967
968 #ifdef DEBUG_EXEC
969 {
970 size_t j;
971 struct exec_vmcmd *vp = &data->ed_pack.ep_vmcmds.evs_cmds[0];
972 DPRINTF(("vmcmds %u\n", data->ed_pack.ep_vmcmds.evs_used));
973 for (j = 0; j < data->ed_pack.ep_vmcmds.evs_used; j++) {
974 DPRINTF(("vmcmd[%zu] = vmcmd_map_%s %#"
975 PRIxVADDR"/%#"PRIxVSIZE" fd@%#"
976 PRIxVSIZE" prot=0%o flags=%d\n", j,
977 vp[j].ev_proc == vmcmd_map_pagedvn ?
978 "pagedvn" :
979 vp[j].ev_proc == vmcmd_map_readvn ?
980 "readvn" :
981 vp[j].ev_proc == vmcmd_map_zero ?
982 "zero" : "*unknown*",
983 vp[j].ev_addr, vp[j].ev_len,
984 vp[j].ev_offset, vp[j].ev_prot,
985 vp[j].ev_flags));
986 }
987 }
988 #endif /* DEBUG_EXEC */
989
990 for (i = 0; i < data->ed_pack.ep_vmcmds.evs_used && !error; i++) {
991 struct exec_vmcmd *vcp;
992
993 vcp = &data->ed_pack.ep_vmcmds.evs_cmds[i];
994 if (vcp->ev_flags & VMCMD_RELATIVE) {
995 #ifdef DIAGNOSTIC
996 if (base_vcp == NULL)
997 panic("%s: relative vmcmd with no base",
998 __func__);
999 if (vcp->ev_flags & VMCMD_BASE)
1000 panic("%s: illegal base & relative vmcmd",
1001 __func__);
1002 #endif
1003 vcp->ev_addr += base_vcp->ev_addr;
1004 }
1005 error = (*vcp->ev_proc)(l, vcp);
1006 #ifdef DEBUG_EXEC
1007 if (error) {
1008 size_t j;
1009 struct exec_vmcmd *vp =
1010 &data->ed_pack.ep_vmcmds.evs_cmds[0];
1011 DPRINTF(("vmcmds %zu/%u, error %d\n", i,
1012 data->ed_pack.ep_vmcmds.evs_used, error));
1013 for (j = 0; j < data->ed_pack.ep_vmcmds.evs_used; j++) {
1014 DPRINTF(("vmcmd[%zu] = vmcmd_map_%s %#"
1015 PRIxVADDR"/%#"PRIxVSIZE" fd@%#"
1016 PRIxVSIZE" prot=0%o flags=%d\n", j,
1017 vp[j].ev_proc == vmcmd_map_pagedvn ?
1018 "pagedvn" :
1019 vp[j].ev_proc == vmcmd_map_readvn ?
1020 "readvn" :
1021 vp[j].ev_proc == vmcmd_map_zero ?
1022 "zero" : "*unknown*",
1023 vp[j].ev_addr, vp[j].ev_len,
1024 vp[j].ev_offset, vp[j].ev_prot,
1025 vp[j].ev_flags));
1026 if (j == i)
1027 DPRINTF((" ^--- failed\n"));
1028 }
1029 }
1030 #endif /* DEBUG_EXEC */
1031 if (vcp->ev_flags & VMCMD_BASE)
1032 base_vcp = vcp;
1033 }
1034
1035 /* free the vmspace-creation commands, and release their references */
1036 kill_vmcmds(&data->ed_pack.ep_vmcmds);
1037
1038 vn_lock(data->ed_pack.ep_vp, LK_EXCLUSIVE | LK_RETRY);
1039 VOP_CLOSE(data->ed_pack.ep_vp, FREAD, l->l_cred);
1040 vput(data->ed_pack.ep_vp);
1041
1042 /* if an error happened, deallocate and punt */
1043 if (error) {
1044 DPRINTF(("%s: vmcmd %zu failed: %d\n", __func__, i - 1, error));
1045 goto exec_abort;
1046 }
1047
1048 /* remember information about the process */
1049 data->ed_arginfo.ps_nargvstr = data->ed_argc;
1050 data->ed_arginfo.ps_nenvstr = data->ed_envc;
1051
1052 /* set command name & other accounting info */
1053 commandname = strrchr(data->ed_pack.ep_resolvedname, '/');
1054 if (commandname != NULL) {
1055 commandname++;
1056 } else {
1057 commandname = data->ed_pack.ep_resolvedname;
1058 }
1059 i = min(strlen(commandname), MAXCOMLEN);
1060 (void)memcpy(p->p_comm, commandname, i);
1061 p->p_comm[i] = '\0';
1062
1063 dp = PNBUF_GET();
1064 /*
1065 * If the path starts with /, we don't need to do any work.
1066 * This handles the majority of the cases.
1067 * In the future perhaps we could canonicalize it?
1068 */
1069 if (data->ed_pathstring[0] == '/')
1070 (void)strlcpy(data->ed_pack.ep_path = dp, data->ed_pathstring,
1071 MAXPATHLEN);
1072 #ifdef notyet
1073 /*
1074 * Although this works most of the time [since the entry was just
1075 * entered in the cache] we don't use it because it theoretically
1076 * can fail and it is not the cleanest interface, because there
1077 * could be races. When the namei cache is re-written, this can
1078 * be changed to use the appropriate function.
1079 */
1080 else if (!(error = vnode_to_path(dp, MAXPATHLEN, p->p_textvp, l, p)))
1081 data->ed_pack.ep_path = dp;
1082 #endif
1083 else {
1084 #ifdef notyet
1085 printf("Cannot get path for pid %d [%s] (error %d)\n",
1086 (int)p->p_pid, p->p_comm, error);
1087 #endif
1088 data->ed_pack.ep_path = NULL;
1089 PNBUF_PUT(dp);
1090 }
1091
1092 stack = (char *)STACK_ALLOC(STACK_GROW(vm->vm_minsaddr,
1093 STACK_PTHREADSPACE + data->ed_ps_strings_sz + data->ed_szsigcode),
1094 data->ed_pack.ep_ssize - (data->ed_ps_strings_sz + data->ed_szsigcode));
1095
1096 #ifdef __MACHINE_STACK_GROWS_UP
1097 /*
1098 * The copyargs call always copies into lower addresses
1099 * first, moving towards higher addresses, starting with
1100 * the stack pointer that we give. When the stack grows
1101 * down, this puts argc/argv/envp very shallow on the
1102 * stack, right at the first user stack pointer.
1103 * When the stack grows up, the situation is reversed.
1104 *
1105 * Normally, this is no big deal. But the ld_elf.so _rtld()
1106 * function expects to be called with a single pointer to
1107 * a region that has a few words it can stash values into,
1108 * followed by argc/argv/envp. When the stack grows down,
1109 * it's easy to decrement the stack pointer a little bit to
1110 * allocate the space for these few words and pass the new
1111 * stack pointer to _rtld. When the stack grows up, however,
1112 * a few words before argc is part of the signal trampoline, XXX
1113 * so we have a problem.
1114 *
1115 * Instead of changing how _rtld works, we take the easy way
1116 * out and steal 32 bytes before we call copyargs.
1117 * This extra space was allowed for when 'pack.ep_ssize' was calculated.
1118 */
1119 stack += RTLD_GAP;
1120 #endif /* __MACHINE_STACK_GROWS_UP */
1121
1122 /* Now copy argc, args & environ to new stack */
1123 error = (*data->ed_pack.ep_esch->es_copyargs)(l, &data->ed_pack,
1124 &data->ed_arginfo, &stack, data->ed_argp);
1125
1126 if (data->ed_pack.ep_path) {
1127 PNBUF_PUT(data->ed_pack.ep_path);
1128 data->ed_pack.ep_path = NULL;
1129 }
1130 if (error) {
1131 DPRINTF(("%s: copyargs failed %d\n", __func__, error));
1132 goto exec_abort;
1133 }
1134 /* Move the stack back to original point */
1135 stack = (char *)STACK_GROW(vm->vm_minsaddr, data->ed_pack.ep_ssize);
1136
1137 /* fill process ps_strings info */
1138 p->p_psstrp = (vaddr_t)STACK_ALLOC(STACK_GROW(vm->vm_minsaddr,
1139 STACK_PTHREADSPACE), data->ed_ps_strings_sz);
1140
1141 if (data->ed_pack.ep_flags & EXEC_32) {
1142 arginfo32.ps_argvstr = (vaddr_t)data->ed_arginfo.ps_argvstr;
1143 arginfo32.ps_nargvstr = data->ed_arginfo.ps_nargvstr;
1144 arginfo32.ps_envstr = (vaddr_t)data->ed_arginfo.ps_envstr;
1145 arginfo32.ps_nenvstr = data->ed_arginfo.ps_nenvstr;
1146 }
1147
1148 /* copy out the process's ps_strings structure */
1149 if ((error = copyout(aip, (void *)p->p_psstrp, data->ed_ps_strings_sz))
1150 != 0) {
1151 DPRINTF(("%s: ps_strings copyout %p->%p size %zu failed\n",
1152 __func__, aip, (void *)p->p_psstrp, data->ed_ps_strings_sz));
1153 goto exec_abort;
1154 }
1155
1156 cwdexec(p);
1157 fd_closeexec(); /* handle close on exec */
1158
1159 if (__predict_false(ktrace_on))
1160 fd_ktrexecfd();
1161
1162 execsigs(p); /* reset catched signals */
1163
1164 l->l_ctxlink = NULL; /* reset ucontext link */
1165
1166
1167 p->p_acflag &= ~AFORK;
1168 mutex_enter(p->p_lock);
1169 p->p_flag |= PK_EXEC;
1170 mutex_exit(p->p_lock);
1171
1172 /*
1173 * Stop profiling.
1174 */
1175 if ((p->p_stflag & PST_PROFIL) != 0) {
1176 mutex_spin_enter(&p->p_stmutex);
1177 stopprofclock(p);
1178 mutex_spin_exit(&p->p_stmutex);
1179 }
1180
1181 /*
1182 * It's OK to test PL_PPWAIT unlocked here, as other LWPs have
1183 * exited and exec()/exit() are the only places it will be cleared.
1184 */
1185 if ((p->p_lflag & PL_PPWAIT) != 0) {
1186 #if 0
1187 lwp_t *lp;
1188
1189 mutex_enter(proc_lock);
1190 lp = p->p_vforklwp;
1191 p->p_vforklwp = NULL;
1192
1193 l->l_lwpctl = NULL; /* was on loan from blocked parent */
1194 p->p_lflag &= ~PL_PPWAIT;
1195
1196 lp->l_pflag &= ~LP_VFORKWAIT; /* XXX */
1197 cv_broadcast(&lp->l_waitcv);
1198 mutex_exit(proc_lock);
1199 #else
1200 mutex_enter(proc_lock);
1201 l->l_lwpctl = NULL; /* was on loan from blocked parent */
1202 p->p_lflag &= ~PL_PPWAIT;
1203 cv_broadcast(&p->p_pptr->p_waitcv);
1204 mutex_exit(proc_lock);
1205 #endif
1206 }
1207
1208 /*
1209 * Deal with set[ug]id. MNT_NOSUID has already been used to disable
1210 * s[ug]id. It's OK to check for PSL_TRACED here as we have blocked
1211 * out additional references on the process for the moment.
1212 */
1213 if ((p->p_slflag & PSL_TRACED) == 0 &&
1214
1215 (((data->ed_attr.va_mode & S_ISUID) != 0 &&
1216 kauth_cred_geteuid(l->l_cred) != data->ed_attr.va_uid) ||
1217
1218 ((data->ed_attr.va_mode & S_ISGID) != 0 &&
1219 kauth_cred_getegid(l->l_cred) != data->ed_attr.va_gid))) {
1220 /*
1221 * Mark the process as SUGID before we do
1222 * anything that might block.
1223 */
1224 proc_crmod_enter();
1225 proc_crmod_leave(NULL, NULL, true);
1226
1227 /* Make sure file descriptors 0..2 are in use. */
1228 if ((error = fd_checkstd()) != 0) {
1229 DPRINTF(("%s: fdcheckstd failed %d\n",
1230 __func__, error));
1231 goto exec_abort;
1232 }
1233
1234 /*
1235 * Copy the credential so other references don't see our
1236 * changes.
1237 */
1238 l->l_cred = kauth_cred_copy(l->l_cred);
1239 #ifdef KTRACE
1240 /*
1241 * If the persistent trace flag isn't set, turn off.
1242 */
1243 if (p->p_tracep) {
1244 mutex_enter(&ktrace_lock);
1245 if (!(p->p_traceflag & KTRFAC_PERSISTENT))
1246 ktrderef(p);
1247 mutex_exit(&ktrace_lock);
1248 }
1249 #endif
1250 if (data->ed_attr.va_mode & S_ISUID)
1251 kauth_cred_seteuid(l->l_cred, data->ed_attr.va_uid);
1252 if (data->ed_attr.va_mode & S_ISGID)
1253 kauth_cred_setegid(l->l_cred, data->ed_attr.va_gid);
1254 } else {
1255 if (kauth_cred_geteuid(l->l_cred) ==
1256 kauth_cred_getuid(l->l_cred) &&
1257 kauth_cred_getegid(l->l_cred) ==
1258 kauth_cred_getgid(l->l_cred))
1259 p->p_flag &= ~PK_SUGID;
1260 }
1261
1262 /*
1263 * Copy the credential so other references don't see our changes.
1264 * Test to see if this is necessary first, since in the common case
1265 * we won't need a private reference.
1266 */
1267 if (kauth_cred_geteuid(l->l_cred) != kauth_cred_getsvuid(l->l_cred) ||
1268 kauth_cred_getegid(l->l_cred) != kauth_cred_getsvgid(l->l_cred)) {
1269 l->l_cred = kauth_cred_copy(l->l_cred);
1270 kauth_cred_setsvuid(l->l_cred, kauth_cred_geteuid(l->l_cred));
1271 kauth_cred_setsvgid(l->l_cred, kauth_cred_getegid(l->l_cred));
1272 }
1273
1274 /* Update the master credentials. */
1275 if (l->l_cred != p->p_cred) {
1276 kauth_cred_t ocred;
1277
1278 kauth_cred_hold(l->l_cred);
1279 mutex_enter(p->p_lock);
1280 ocred = p->p_cred;
1281 p->p_cred = l->l_cred;
1282 mutex_exit(p->p_lock);
1283 kauth_cred_free(ocred);
1284 }
1285
1286 #if defined(__HAVE_RAS)
1287 /*
1288 * Remove all RASs from the address space.
1289 */
1290 ras_purgeall();
1291 #endif
1292
1293 doexechooks(p);
1294
1295 /* setup new registers and do misc. setup. */
1296 (*data->ed_pack.ep_esch->es_emul->e_setregs)(l, &data->ed_pack,
1297 (vaddr_t)stack);
1298 if (data->ed_pack.ep_esch->es_setregs)
1299 (*data->ed_pack.ep_esch->es_setregs)(l, &data->ed_pack,
1300 (vaddr_t)stack);
1301
1302 /* Provide a consistent LWP private setting */
1303 (void)lwp_setprivate(l, NULL);
1304
1305 /* Discard all PCU state; need to start fresh */
1306 pcu_discard_all(l);
1307
1308 /* map the process's signal trampoline code */
1309 if ((error = exec_sigcode_map(p, data->ed_pack.ep_esch->es_emul)) != 0) {
1310 DPRINTF(("%s: map sigcode failed %d\n", __func__, error));
1311 goto exec_abort;
1312 }
1313
1314 pool_put(&exec_pool, data->ed_argp);
1315
1316 /* notify others that we exec'd */
1317 KNOTE(&p->p_klist, NOTE_EXEC);
1318
1319 kmem_free(data->ed_pack.ep_hdr, data->ed_pack.ep_hdrlen);
1320
1321 SDT_PROBE(proc,,,exec_success, data->ed_pack.ep_name, 0, 0, 0, 0);
1322
1323 /* The emulation root will usually have been found when we looked
1324 * for the elf interpreter (or similar), if not look now. */
1325 if (data->ed_pack.ep_esch->es_emul->e_path != NULL &&
1326 data->ed_pack.ep_emul_root == NULL)
1327 emul_find_root(l, &data->ed_pack);
1328
1329 /* Any old emulation root got removed by fdcloseexec */
1330 rw_enter(&p->p_cwdi->cwdi_lock, RW_WRITER);
1331 p->p_cwdi->cwdi_edir = data->ed_pack.ep_emul_root;
1332 rw_exit(&p->p_cwdi->cwdi_lock);
1333 data->ed_pack.ep_emul_root = NULL;
1334 if (data->ed_pack.ep_interp != NULL)
1335 vrele(data->ed_pack.ep_interp);
1336
1337 /*
1338 * Call emulation specific exec hook. This can setup per-process
1339 * p->p_emuldata or do any other per-process stuff an emulation needs.
1340 *
1341 * If we are executing process of different emulation than the
1342 * original forked process, call e_proc_exit() of the old emulation
1343 * first, then e_proc_exec() of new emulation. If the emulation is
1344 * same, the exec hook code should deallocate any old emulation
1345 * resources held previously by this process.
1346 */
1347 if (p->p_emul && p->p_emul->e_proc_exit
1348 && p->p_emul != data->ed_pack.ep_esch->es_emul)
1349 (*p->p_emul->e_proc_exit)(p);
1350
1351 /*
1352 * This is now LWP 1.
1353 */
1354 mutex_enter(p->p_lock);
1355 p->p_nlwpid = 1;
1356 l->l_lid = 1;
1357 mutex_exit(p->p_lock);
1358
1359 /*
1360 * Call exec hook. Emulation code may NOT store reference to anything
1361 * from &pack.
1362 */
1363 if (data->ed_pack.ep_esch->es_emul->e_proc_exec)
1364 (*data->ed_pack.ep_esch->es_emul->e_proc_exec)(p, &data->ed_pack);
1365
1366 /* update p_emul, the old value is no longer needed */
1367 p->p_emul = data->ed_pack.ep_esch->es_emul;
1368
1369 /* ...and the same for p_execsw */
1370 p->p_execsw = data->ed_pack.ep_esch;
1371
1372 #ifdef __HAVE_SYSCALL_INTERN
1373 (*p->p_emul->e_syscall_intern)(p);
1374 #endif
1375 ktremul();
1376
1377 /* Allow new references from the debugger/procfs. */
1378 rw_exit(&p->p_reflock);
1379 if (!no_local_exec_lock)
1380 rw_exit(&exec_lock);
1381
1382 mutex_enter(proc_lock);
1383
1384 if ((p->p_slflag & (PSL_TRACED|PSL_SYSCALL)) == PSL_TRACED) {
1385 KSI_INIT_EMPTY(&ksi);
1386 ksi.ksi_signo = SIGTRAP;
1387 ksi.ksi_lid = l->l_lid;
1388 kpsignal(p, &ksi, NULL);
1389 }
1390
1391 if (p->p_sflag & PS_STOPEXEC) {
1392 KERNEL_UNLOCK_ALL(l, &l->l_biglocks);
1393 p->p_pptr->p_nstopchild++;
1394 p->p_pptr->p_waited = 0;
1395 mutex_enter(p->p_lock);
1396 ksiginfo_queue_init(&kq);
1397 sigclearall(p, &contsigmask, &kq);
1398 lwp_lock(l);
1399 l->l_stat = LSSTOP;
1400 p->p_stat = SSTOP;
1401 p->p_nrlwps--;
1402 lwp_unlock(l);
1403 mutex_exit(p->p_lock);
1404 mutex_exit(proc_lock);
1405 lwp_lock(l);
1406 mi_switch(l);
1407 ksiginfo_queue_drain(&kq);
1408 KERNEL_LOCK(l->l_biglocks, l);
1409 } else {
1410 mutex_exit(proc_lock);
1411 }
1412
1413 pathbuf_stringcopy_put(data->ed_pathbuf, data->ed_pathstring);
1414 pathbuf_destroy(data->ed_pathbuf);
1415 PNBUF_PUT(data->ed_resolvedpathbuf);
1416 DPRINTF(("%s finished\n", __func__));
1417 return (EJUSTRETURN);
1418
1419 exec_abort:
1420 SDT_PROBE(proc,,,exec_failure, error, 0, 0, 0, 0);
1421 rw_exit(&p->p_reflock);
1422 if (!no_local_exec_lock)
1423 rw_exit(&exec_lock);
1424
1425 pathbuf_stringcopy_put(data->ed_pathbuf, data->ed_pathstring);
1426 pathbuf_destroy(data->ed_pathbuf);
1427 PNBUF_PUT(data->ed_resolvedpathbuf);
1428
1429 /*
1430 * the old process doesn't exist anymore. exit gracefully.
1431 * get rid of the (new) address space we have created, if any, get rid
1432 * of our namei data and vnode, and exit noting failure
1433 */
1434 uvm_deallocate(&vm->vm_map, VM_MIN_ADDRESS,
1435 VM_MAXUSER_ADDRESS - VM_MIN_ADDRESS);
1436
1437 exec_free_emul_arg(&data->ed_pack);
1438 pool_put(&exec_pool, data->ed_argp);
1439 kmem_free(data->ed_pack.ep_hdr, data->ed_pack.ep_hdrlen);
1440 if (data->ed_pack.ep_emul_root != NULL)
1441 vrele(data->ed_pack.ep_emul_root);
1442 if (data->ed_pack.ep_interp != NULL)
1443 vrele(data->ed_pack.ep_interp);
1444
1445 /* Acquire the sched-state mutex (exit1() will release it). */
1446 if (!is_spawn) {
1447 mutex_enter(p->p_lock);
1448 exit1(l, W_EXITCODE(error, SIGABRT));
1449 }
1450
1451 return error;
1452 }
1453
1454 int
1455 execve1(struct lwp *l, const char *path, char * const *args,
1456 char * const *envs, execve_fetch_element_t fetch_element)
1457 {
1458 struct execve_data data;
1459 int error;
1460
1461 error = execve_loadvm(l, path, args, envs, fetch_element, &data);
1462 if (error)
1463 return error;
1464 error = execve_runproc(l, &data, false, false);
1465 return error;
1466 }
1467
1468 int
1469 copyargs(struct lwp *l, struct exec_package *pack, struct ps_strings *arginfo,
1470 char **stackp, void *argp)
1471 {
1472 char **cpp, *dp, *sp;
1473 size_t len;
1474 void *nullp;
1475 long argc, envc;
1476 int error;
1477
1478 cpp = (char **)*stackp;
1479 nullp = NULL;
1480 argc = arginfo->ps_nargvstr;
1481 envc = arginfo->ps_nenvstr;
1482 if ((error = copyout(&argc, cpp++, sizeof(argc))) != 0) {
1483 COPYPRINTF("", cpp - 1, sizeof(argc));
1484 return error;
1485 }
1486
1487 dp = (char *) (cpp + argc + envc + 2 + pack->ep_esch->es_arglen);
1488 sp = argp;
1489
1490 /* XXX don't copy them out, remap them! */
1491 arginfo->ps_argvstr = cpp; /* remember location of argv for later */
1492
1493 for (; --argc >= 0; sp += len, dp += len) {
1494 if ((error = copyout(&dp, cpp++, sizeof(dp))) != 0) {
1495 COPYPRINTF("", cpp - 1, sizeof(dp));
1496 return error;
1497 }
1498 if ((error = copyoutstr(sp, dp, ARG_MAX, &len)) != 0) {
1499 COPYPRINTF("str", dp, (size_t)ARG_MAX);
1500 return error;
1501 }
1502 }
1503
1504 if ((error = copyout(&nullp, cpp++, sizeof(nullp))) != 0) {
1505 COPYPRINTF("", cpp - 1, sizeof(nullp));
1506 return error;
1507 }
1508
1509 arginfo->ps_envstr = cpp; /* remember location of envp for later */
1510
1511 for (; --envc >= 0; sp += len, dp += len) {
1512 if ((error = copyout(&dp, cpp++, sizeof(dp))) != 0) {
1513 COPYPRINTF("", cpp - 1, sizeof(dp));
1514 return error;
1515 }
1516 if ((error = copyoutstr(sp, dp, ARG_MAX, &len)) != 0) {
1517 COPYPRINTF("str", dp, (size_t)ARG_MAX);
1518 return error;
1519 }
1520
1521 }
1522
1523 if ((error = copyout(&nullp, cpp++, sizeof(nullp))) != 0) {
1524 COPYPRINTF("", cpp - 1, sizeof(nullp));
1525 return error;
1526 }
1527
1528 *stackp = (char *)cpp;
1529 return 0;
1530 }
1531
1532
1533 /*
1534 * Add execsw[] entries.
1535 */
1536 int
1537 exec_add(struct execsw *esp, int count)
1538 {
1539 struct exec_entry *it;
1540 int i;
1541
1542 if (count == 0) {
1543 return 0;
1544 }
1545
1546 /* Check for duplicates. */
1547 rw_enter(&exec_lock, RW_WRITER);
1548 for (i = 0; i < count; i++) {
1549 LIST_FOREACH(it, &ex_head, ex_list) {
1550 /* assume unique (makecmds, probe_func, emulation) */
1551 if (it->ex_sw->es_makecmds == esp[i].es_makecmds &&
1552 it->ex_sw->u.elf_probe_func ==
1553 esp[i].u.elf_probe_func &&
1554 it->ex_sw->es_emul == esp[i].es_emul) {
1555 rw_exit(&exec_lock);
1556 return EEXIST;
1557 }
1558 }
1559 }
1560
1561 /* Allocate new entries. */
1562 for (i = 0; i < count; i++) {
1563 it = kmem_alloc(sizeof(*it), KM_SLEEP);
1564 it->ex_sw = &esp[i];
1565 LIST_INSERT_HEAD(&ex_head, it, ex_list);
1566 }
1567
1568 /* update execsw[] */
1569 exec_init(0);
1570 rw_exit(&exec_lock);
1571 return 0;
1572 }
1573
1574 /*
1575 * Remove execsw[] entry.
1576 */
1577 int
1578 exec_remove(struct execsw *esp, int count)
1579 {
1580 struct exec_entry *it, *next;
1581 int i;
1582 const struct proclist_desc *pd;
1583 proc_t *p;
1584
1585 if (count == 0) {
1586 return 0;
1587 }
1588
1589 /* Abort if any are busy. */
1590 rw_enter(&exec_lock, RW_WRITER);
1591 for (i = 0; i < count; i++) {
1592 mutex_enter(proc_lock);
1593 for (pd = proclists; pd->pd_list != NULL; pd++) {
1594 PROCLIST_FOREACH(p, pd->pd_list) {
1595 if (p->p_execsw == &esp[i]) {
1596 mutex_exit(proc_lock);
1597 rw_exit(&exec_lock);
1598 return EBUSY;
1599 }
1600 }
1601 }
1602 mutex_exit(proc_lock);
1603 }
1604
1605 /* None are busy, so remove them all. */
1606 for (i = 0; i < count; i++) {
1607 for (it = LIST_FIRST(&ex_head); it != NULL; it = next) {
1608 next = LIST_NEXT(it, ex_list);
1609 if (it->ex_sw == &esp[i]) {
1610 LIST_REMOVE(it, ex_list);
1611 kmem_free(it, sizeof(*it));
1612 break;
1613 }
1614 }
1615 }
1616
1617 /* update execsw[] */
1618 exec_init(0);
1619 rw_exit(&exec_lock);
1620 return 0;
1621 }
1622
1623 /*
1624 * Initialize exec structures. If init_boot is true, also does necessary
1625 * one-time initialization (it's called from main() that way).
1626 * Once system is multiuser, this should be called with exec_lock held,
1627 * i.e. via exec_{add|remove}().
1628 */
1629 int
1630 exec_init(int init_boot)
1631 {
1632 const struct execsw **sw;
1633 struct exec_entry *ex;
1634 SLIST_HEAD(,exec_entry) first;
1635 SLIST_HEAD(,exec_entry) any;
1636 SLIST_HEAD(,exec_entry) last;
1637 int i, sz;
1638
1639 if (init_boot) {
1640 /* do one-time initializations */
1641 rw_init(&exec_lock);
1642 mutex_init(&sigobject_lock, MUTEX_DEFAULT, IPL_NONE);
1643 pool_init(&exec_pool, NCARGS, 0, 0, PR_NOALIGN|PR_NOTOUCH,
1644 "execargs", &exec_palloc, IPL_NONE);
1645 pool_sethardlimit(&exec_pool, maxexec, "should not happen", 0);
1646 } else {
1647 KASSERT(rw_write_held(&exec_lock));
1648 }
1649
1650 /* Sort each entry onto the appropriate queue. */
1651 SLIST_INIT(&first);
1652 SLIST_INIT(&any);
1653 SLIST_INIT(&last);
1654 sz = 0;
1655 LIST_FOREACH(ex, &ex_head, ex_list) {
1656 switch(ex->ex_sw->es_prio) {
1657 case EXECSW_PRIO_FIRST:
1658 SLIST_INSERT_HEAD(&first, ex, ex_slist);
1659 break;
1660 case EXECSW_PRIO_ANY:
1661 SLIST_INSERT_HEAD(&any, ex, ex_slist);
1662 break;
1663 case EXECSW_PRIO_LAST:
1664 SLIST_INSERT_HEAD(&last, ex, ex_slist);
1665 break;
1666 default:
1667 panic("%s", __func__);
1668 break;
1669 }
1670 sz++;
1671 }
1672
1673 /*
1674 * Create new execsw[]. Ensure we do not try a zero-sized
1675 * allocation.
1676 */
1677 sw = kmem_alloc(sz * sizeof(struct execsw *) + 1, KM_SLEEP);
1678 i = 0;
1679 SLIST_FOREACH(ex, &first, ex_slist) {
1680 sw[i++] = ex->ex_sw;
1681 }
1682 SLIST_FOREACH(ex, &any, ex_slist) {
1683 sw[i++] = ex->ex_sw;
1684 }
1685 SLIST_FOREACH(ex, &last, ex_slist) {
1686 sw[i++] = ex->ex_sw;
1687 }
1688
1689 /* Replace old execsw[] and free used memory. */
1690 if (execsw != NULL) {
1691 kmem_free(__UNCONST(execsw),
1692 nexecs * sizeof(struct execsw *) + 1);
1693 }
1694 execsw = sw;
1695 nexecs = sz;
1696
1697 /* Figure out the maximum size of an exec header. */
1698 exec_maxhdrsz = sizeof(int);
1699 for (i = 0; i < nexecs; i++) {
1700 if (execsw[i]->es_hdrsz > exec_maxhdrsz)
1701 exec_maxhdrsz = execsw[i]->es_hdrsz;
1702 }
1703
1704 return 0;
1705 }
1706
1707 static int
1708 exec_sigcode_map(struct proc *p, const struct emul *e)
1709 {
1710 vaddr_t va;
1711 vsize_t sz;
1712 int error;
1713 struct uvm_object *uobj;
1714
1715 sz = (vaddr_t)e->e_esigcode - (vaddr_t)e->e_sigcode;
1716
1717 if (e->e_sigobject == NULL || sz == 0) {
1718 return 0;
1719 }
1720
1721 /*
1722 * If we don't have a sigobject for this emulation, create one.
1723 *
1724 * sigobject is an anonymous memory object (just like SYSV shared
1725 * memory) that we keep a permanent reference to and that we map
1726 * in all processes that need this sigcode. The creation is simple,
1727 * we create an object, add a permanent reference to it, map it in
1728 * kernel space, copy out the sigcode to it and unmap it.
1729 * We map it with PROT_READ|PROT_EXEC into the process just
1730 * the way sys_mmap() would map it.
1731 */
1732
1733 uobj = *e->e_sigobject;
1734 if (uobj == NULL) {
1735 mutex_enter(&sigobject_lock);
1736 if ((uobj = *e->e_sigobject) == NULL) {
1737 uobj = uao_create(sz, 0);
1738 (*uobj->pgops->pgo_reference)(uobj);
1739 va = vm_map_min(kernel_map);
1740 if ((error = uvm_map(kernel_map, &va, round_page(sz),
1741 uobj, 0, 0,
1742 UVM_MAPFLAG(UVM_PROT_RW, UVM_PROT_RW,
1743 UVM_INH_SHARE, UVM_ADV_RANDOM, 0)))) {
1744 printf("kernel mapping failed %d\n", error);
1745 (*uobj->pgops->pgo_detach)(uobj);
1746 mutex_exit(&sigobject_lock);
1747 return (error);
1748 }
1749 memcpy((void *)va, e->e_sigcode, sz);
1750 #ifdef PMAP_NEED_PROCWR
1751 pmap_procwr(&proc0, va, sz);
1752 #endif
1753 uvm_unmap(kernel_map, va, va + round_page(sz));
1754 *e->e_sigobject = uobj;
1755 }
1756 mutex_exit(&sigobject_lock);
1757 }
1758
1759 /* Just a hint to uvm_map where to put it. */
1760 va = e->e_vm_default_addr(p, (vaddr_t)p->p_vmspace->vm_daddr,
1761 round_page(sz));
1762
1763 #ifdef __alpha__
1764 /*
1765 * Tru64 puts /sbin/loader at the end of user virtual memory,
1766 * which causes the above calculation to put the sigcode at
1767 * an invalid address. Put it just below the text instead.
1768 */
1769 if (va == (vaddr_t)vm_map_max(&p->p_vmspace->vm_map)) {
1770 va = (vaddr_t)p->p_vmspace->vm_taddr - round_page(sz);
1771 }
1772 #endif
1773
1774 (*uobj->pgops->pgo_reference)(uobj);
1775 error = uvm_map(&p->p_vmspace->vm_map, &va, round_page(sz),
1776 uobj, 0, 0,
1777 UVM_MAPFLAG(UVM_PROT_RX, UVM_PROT_RX, UVM_INH_SHARE,
1778 UVM_ADV_RANDOM, 0));
1779 if (error) {
1780 DPRINTF(("%s, %d: map %p "
1781 "uvm_map %#"PRIxVSIZE"@%#"PRIxVADDR" failed %d\n",
1782 __func__, __LINE__, &p->p_vmspace->vm_map, round_page(sz),
1783 va, error));
1784 (*uobj->pgops->pgo_detach)(uobj);
1785 return (error);
1786 }
1787 p->p_sigctx.ps_sigcode = (void *)va;
1788 return (0);
1789 }
1790
1791 /*
1792 * Release a refcount on spawn_exec_data and destroy memory, if this
1793 * was the last one.
1794 */
1795 static void
1796 spawn_exec_data_release(struct spawn_exec_data *data)
1797 {
1798 if (atomic_dec_32_nv(&data->sed_refcnt) != 0)
1799 return;
1800
1801 cv_destroy(&data->sed_cv_child_ready);
1802 mutex_destroy(&data->sed_mtx_child);
1803
1804 if (data->sed_actions)
1805 posix_spawn_fa_free(data->sed_actions,
1806 data->sed_actions->len);
1807 if (data->sed_attrs)
1808 kmem_free(data->sed_attrs,
1809 sizeof(*data->sed_attrs));
1810 kmem_free(data, sizeof(*data));
1811 }
1812
1813 /*
1814 * A child lwp of a posix_spawn operation starts here and ends up in
1815 * cpu_spawn_return, dealing with all filedescriptor and scheduler
1816 * manipulations in between.
1817 * The parent waits for the child, as it is not clear wether the child
1818 * will be able to aquire its own exec_lock. If it can, the parent can
1819 * be released early and continue running in parallel. If not (or if the
1820 * magic debug flag is passed in the scheduler attribute struct), the
1821 * child rides on the parent's exec lock untill it is ready to return to
1822 * to userland - and only then releases the parent. This method loses
1823 * concurrency, but improves error reporting.
1824 */
1825 static void
1826 spawn_return(void *arg)
1827 {
1828 struct spawn_exec_data *spawn_data = arg;
1829 struct lwp *l = curlwp;
1830 int error, newfd;
1831 size_t i;
1832 const struct posix_spawn_file_actions_entry *fae;
1833 pid_t ppid;
1834 register_t retval;
1835 bool have_reflock;
1836 bool parent_is_waiting = true;
1837
1838 /*
1839 * Check if we can release parent early.
1840 * We either need to have no sed_attrs, or sed_attrs does not
1841 * have POSIX_SPAWN_RETURNERROR or one of the flags, that require
1842 * safe access to the parent proc (passed in sed_parent).
1843 * We then try to get the exec_lock, and only if that works, we can
1844 * release the parent here already.
1845 */
1846 ppid = spawn_data->sed_parent->p_pid;
1847 if ((!spawn_data->sed_attrs
1848 || (spawn_data->sed_attrs->sa_flags
1849 & (POSIX_SPAWN_RETURNERROR|POSIX_SPAWN_SETPGROUP)) == 0)
1850 && rw_tryenter(&exec_lock, RW_READER)) {
1851 parent_is_waiting = false;
1852 mutex_enter(&spawn_data->sed_mtx_child);
1853 cv_signal(&spawn_data->sed_cv_child_ready);
1854 mutex_exit(&spawn_data->sed_mtx_child);
1855 }
1856
1857 /* don't allow debugger access yet */
1858 rw_enter(&l->l_proc->p_reflock, RW_WRITER);
1859 have_reflock = true;
1860
1861 error = 0;
1862 /* handle posix_spawn_file_actions */
1863 if (spawn_data->sed_actions != NULL) {
1864 for (i = 0; i < spawn_data->sed_actions->len; i++) {
1865 fae = &spawn_data->sed_actions->fae[i];
1866 switch (fae->fae_action) {
1867 case FAE_OPEN:
1868 if (fd_getfile(fae->fae_fildes) != NULL) {
1869 error = fd_close(fae->fae_fildes);
1870 if (error)
1871 break;
1872 }
1873 error = fd_open(fae->fae_path, fae->fae_oflag,
1874 fae->fae_mode, &newfd);
1875 if (error)
1876 break;
1877 if (newfd != fae->fae_fildes) {
1878 error = dodup(l, newfd,
1879 fae->fae_fildes, 0, &retval);
1880 if (fd_getfile(newfd) != NULL)
1881 fd_close(newfd);
1882 }
1883 break;
1884 case FAE_DUP2:
1885 error = dodup(l, fae->fae_fildes,
1886 fae->fae_newfildes, 0, &retval);
1887 break;
1888 case FAE_CLOSE:
1889 if (fd_getfile(fae->fae_fildes) == NULL) {
1890 error = EBADF;
1891 break;
1892 }
1893 error = fd_close(fae->fae_fildes);
1894 break;
1895 }
1896 if (error)
1897 goto report_error;
1898 }
1899 }
1900
1901 /* handle posix_spawnattr */
1902 if (spawn_data->sed_attrs != NULL) {
1903 int ostat;
1904 struct sigaction sigact;
1905 sigact._sa_u._sa_handler = SIG_DFL;
1906 sigact.sa_flags = 0;
1907
1908 /*
1909 * set state to SSTOP so that this proc can be found by pid.
1910 * see proc_enterprp, do_sched_setparam below
1911 */
1912 ostat = l->l_proc->p_stat;
1913 l->l_proc->p_stat = SSTOP;
1914
1915 /* Set process group */
1916 if (spawn_data->sed_attrs->sa_flags & POSIX_SPAWN_SETPGROUP) {
1917 pid_t mypid = l->l_proc->p_pid,
1918 pgrp = spawn_data->sed_attrs->sa_pgroup;
1919
1920 if (pgrp == 0)
1921 pgrp = mypid;
1922
1923 error = proc_enterpgrp(spawn_data->sed_parent,
1924 mypid, pgrp, false);
1925 if (error)
1926 goto report_error;
1927 }
1928
1929 /* Set scheduler policy */
1930 if (spawn_data->sed_attrs->sa_flags & POSIX_SPAWN_SETSCHEDULER)
1931 error = do_sched_setparam(l->l_proc->p_pid, 0,
1932 spawn_data->sed_attrs->sa_schedpolicy,
1933 &spawn_data->sed_attrs->sa_schedparam);
1934 else if (spawn_data->sed_attrs->sa_flags
1935 & POSIX_SPAWN_SETSCHEDPARAM) {
1936 error = do_sched_setparam(ppid, 0,
1937 SCHED_NONE, &spawn_data->sed_attrs->sa_schedparam);
1938 }
1939 if (error)
1940 goto report_error;
1941
1942 /* Reset user ID's */
1943 if (spawn_data->sed_attrs->sa_flags & POSIX_SPAWN_RESETIDS) {
1944 error = do_setresuid(l, -1,
1945 kauth_cred_getgid(l->l_cred), -1,
1946 ID_E_EQ_R | ID_E_EQ_S);
1947 if (error)
1948 goto report_error;
1949 error = do_setresuid(l, -1,
1950 kauth_cred_getuid(l->l_cred), -1,
1951 ID_E_EQ_R | ID_E_EQ_S);
1952 if (error)
1953 goto report_error;
1954 }
1955
1956 /* Set signal masks/defaults */
1957 if (spawn_data->sed_attrs->sa_flags & POSIX_SPAWN_SETSIGMASK) {
1958 mutex_enter(l->l_proc->p_lock);
1959 error = sigprocmask1(l, SIG_SETMASK,
1960 &spawn_data->sed_attrs->sa_sigmask, NULL);
1961 mutex_exit(l->l_proc->p_lock);
1962 if (error)
1963 goto report_error;
1964 }
1965
1966 if (spawn_data->sed_attrs->sa_flags & POSIX_SPAWN_SETSIGDEF) {
1967 for (i = 1; i <= NSIG; i++) {
1968 if (sigismember(
1969 &spawn_data->sed_attrs->sa_sigdefault, i))
1970 sigaction1(l, i, &sigact, NULL, NULL,
1971 0);
1972 }
1973 }
1974 l->l_proc->p_stat = ostat;
1975 }
1976
1977 /* now do the real exec */
1978 error = execve_runproc(l, &spawn_data->sed_exec, parent_is_waiting,
1979 true);
1980 have_reflock = false;
1981 if (error == EJUSTRETURN)
1982 error = 0;
1983 else if (error)
1984 goto report_error;
1985
1986 if (parent_is_waiting) {
1987 mutex_enter(&spawn_data->sed_mtx_child);
1988 cv_signal(&spawn_data->sed_cv_child_ready);
1989 mutex_exit(&spawn_data->sed_mtx_child);
1990 }
1991
1992 /* release our refcount on the data */
1993 spawn_exec_data_release(spawn_data);
1994
1995 /* and finaly: leave to userland for the first time */
1996 cpu_spawn_return(l);
1997
1998 /* NOTREACHED */
1999 return;
2000
2001 report_error:
2002 if (have_reflock) {
2003 /*
2004 * We have not passed through execve_runproc(),
2005 * which would have released the p_reflock and also
2006 * taken ownership of the sed_exec part of spawn_data,
2007 * so release/free both here.
2008 */
2009 rw_exit(&l->l_proc->p_reflock);
2010 execve_free_data(&spawn_data->sed_exec);
2011 }
2012
2013 if (parent_is_waiting) {
2014 /* pass error to parent */
2015 mutex_enter(&spawn_data->sed_mtx_child);
2016 spawn_data->sed_error = error;
2017 cv_signal(&spawn_data->sed_cv_child_ready);
2018 mutex_exit(&spawn_data->sed_mtx_child);
2019 } else {
2020 rw_exit(&exec_lock);
2021 }
2022
2023 /* release our refcount on the data */
2024 spawn_exec_data_release(spawn_data);
2025
2026 /* done, exit */
2027 mutex_enter(l->l_proc->p_lock);
2028 /*
2029 * Posix explicitly asks for an exit code of 127 if we report
2030 * errors from the child process - so, unfortunately, there
2031 * is no way to report a more exact error code.
2032 * A NetBSD specific workaround is POSIX_SPAWN_RETURNERROR as
2033 * flag bit in the attrp argument to posix_spawn(2), see above.
2034 */
2035 exit1(l, W_EXITCODE(127, 0));
2036 }
2037
2038 void
2039 posix_spawn_fa_free(struct posix_spawn_file_actions *fa, size_t len)
2040 {
2041
2042 for (size_t i = 0; i < len; i++) {
2043 struct posix_spawn_file_actions_entry *fae = &fa->fae[i];
2044 if (fae->fae_action != FAE_OPEN)
2045 continue;
2046 kmem_free(fae->fae_path, strlen(fae->fae_path) + 1);
2047 }
2048 if (fa->len > 0)
2049 kmem_free(fa->fae, sizeof(*fa->fae) * fa->len);
2050 kmem_free(fa, sizeof(*fa));
2051 }
2052
2053 static int
2054 posix_spawn_fa_alloc(struct posix_spawn_file_actions **fap,
2055 const struct posix_spawn_file_actions *ufa)
2056 {
2057 struct posix_spawn_file_actions *fa;
2058 struct posix_spawn_file_actions_entry *fae;
2059 char *pbuf = NULL;
2060 int error;
2061 size_t i = 0;
2062
2063 fa = kmem_alloc(sizeof(*fa), KM_SLEEP);
2064 error = copyin(ufa, fa, sizeof(*fa));
2065 if (error) {
2066 fa->fae = NULL;
2067 fa->len = 0;
2068 goto out;
2069 }
2070
2071 if (fa->len == 0) {
2072 kmem_free(fa, sizeof(*fa));
2073 return 0;
2074 }
2075
2076 fa->size = fa->len;
2077 size_t fal = fa->len * sizeof(*fae);
2078 fae = fa->fae;
2079 fa->fae = kmem_alloc(fal, KM_SLEEP);
2080 error = copyin(fae, fa->fae, fal);
2081 if (error)
2082 goto out;
2083
2084 pbuf = PNBUF_GET();
2085 for (; i < fa->len; i++) {
2086 fae = &fa->fae[i];
2087 if (fae->fae_action != FAE_OPEN)
2088 continue;
2089 error = copyinstr(fae->fae_path, pbuf, MAXPATHLEN, &fal);
2090 if (error)
2091 goto out;
2092 fae->fae_path = kmem_alloc(fal, KM_SLEEP);
2093 memcpy(fae->fae_path, pbuf, fal);
2094 }
2095 PNBUF_PUT(pbuf);
2096
2097 *fap = fa;
2098 return 0;
2099 out:
2100 if (pbuf)
2101 PNBUF_PUT(pbuf);
2102 posix_spawn_fa_free(fa, i);
2103 return error;
2104 }
2105
2106 int
2107 check_posix_spawn(struct lwp *l1)
2108 {
2109 int error, tnprocs, count;
2110 uid_t uid;
2111 struct proc *p1;
2112
2113 p1 = l1->l_proc;
2114 uid = kauth_cred_getuid(l1->l_cred);
2115 tnprocs = atomic_inc_uint_nv(&nprocs);
2116
2117 /*
2118 * Although process entries are dynamically created, we still keep
2119 * a global limit on the maximum number we will create.
2120 */
2121 if (__predict_false(tnprocs >= maxproc))
2122 error = -1;
2123 else
2124 error = kauth_authorize_process(l1->l_cred,
2125 KAUTH_PROCESS_FORK, p1, KAUTH_ARG(tnprocs), NULL, NULL);
2126
2127 if (error) {
2128 atomic_dec_uint(&nprocs);
2129 return EAGAIN;
2130 }
2131
2132 /*
2133 * Enforce limits.
2134 */
2135 count = chgproccnt(uid, 1);
2136 if (kauth_authorize_process(l1->l_cred, KAUTH_PROCESS_RLIMIT,
2137 p1, KAUTH_ARG(KAUTH_REQ_PROCESS_RLIMIT_BYPASS),
2138 &p1->p_rlimit[RLIMIT_NPROC], KAUTH_ARG(RLIMIT_NPROC)) != 0 &&
2139 __predict_false(count > p1->p_rlimit[RLIMIT_NPROC].rlim_cur)) {
2140 (void)chgproccnt(uid, -1);
2141 atomic_dec_uint(&nprocs);
2142 return EAGAIN;
2143 }
2144
2145 return 0;
2146 }
2147
2148 int
2149 do_posix_spawn(struct lwp *l1, pid_t *pid_res, bool *child_ok, const char *path,
2150 struct posix_spawn_file_actions *fa,
2151 struct posix_spawnattr *sa,
2152 char *const *argv, char *const *envp,
2153 execve_fetch_element_t fetch)
2154 {
2155
2156 struct proc *p1, *p2;
2157 struct lwp *l2;
2158 int error;
2159 struct spawn_exec_data *spawn_data;
2160 vaddr_t uaddr;
2161 pid_t pid;
2162 bool have_exec_lock = false;
2163
2164 p1 = l1->l_proc;
2165
2166 /* Allocate and init spawn_data */
2167 spawn_data = kmem_zalloc(sizeof(*spawn_data), KM_SLEEP);
2168 spawn_data->sed_refcnt = 1; /* only parent so far */
2169 cv_init(&spawn_data->sed_cv_child_ready, "pspawn");
2170 mutex_init(&spawn_data->sed_mtx_child, MUTEX_DEFAULT, IPL_NONE);
2171 mutex_enter(&spawn_data->sed_mtx_child);
2172
2173 /*
2174 * Do the first part of the exec now, collect state
2175 * in spawn_data.
2176 */
2177 error = execve_loadvm(l1, path, argv,
2178 envp, fetch, &spawn_data->sed_exec);
2179 if (error == EJUSTRETURN)
2180 error = 0;
2181 else if (error)
2182 goto error_exit;
2183
2184 have_exec_lock = true;
2185
2186 /*
2187 * Allocate virtual address space for the U-area now, while it
2188 * is still easy to abort the fork operation if we're out of
2189 * kernel virtual address space.
2190 */
2191 uaddr = uvm_uarea_alloc();
2192 if (__predict_false(uaddr == 0)) {
2193 error = ENOMEM;
2194 goto error_exit;
2195 }
2196
2197 /*
2198 * Allocate new proc. Borrow proc0 vmspace for it, we will
2199 * replace it with its own before returning to userland
2200 * in the child.
2201 * This is a point of no return, we will have to go through
2202 * the child proc to properly clean it up past this point.
2203 */
2204 p2 = proc_alloc();
2205 pid = p2->p_pid;
2206
2207 /*
2208 * Make a proc table entry for the new process.
2209 * Start by zeroing the section of proc that is zero-initialized,
2210 * then copy the section that is copied directly from the parent.
2211 */
2212 memset(&p2->p_startzero, 0,
2213 (unsigned) ((char *)&p2->p_endzero - (char *)&p2->p_startzero));
2214 memcpy(&p2->p_startcopy, &p1->p_startcopy,
2215 (unsigned) ((char *)&p2->p_endcopy - (char *)&p2->p_startcopy));
2216 p2->p_vmspace = proc0.p_vmspace;
2217
2218 CIRCLEQ_INIT(&p2->p_sigpend.sp_info);
2219
2220 LIST_INIT(&p2->p_lwps);
2221 LIST_INIT(&p2->p_sigwaiters);
2222
2223 /*
2224 * Duplicate sub-structures as needed.
2225 * Increase reference counts on shared objects.
2226 * Inherit flags we want to keep. The flags related to SIGCHLD
2227 * handling are important in order to keep a consistent behaviour
2228 * for the child after the fork. If we are a 32-bit process, the
2229 * child will be too.
2230 */
2231 p2->p_flag =
2232 p1->p_flag & (PK_SUGID | PK_NOCLDWAIT | PK_CLDSIGIGN | PK_32);
2233 p2->p_emul = p1->p_emul;
2234 p2->p_execsw = p1->p_execsw;
2235
2236 mutex_init(&p2->p_stmutex, MUTEX_DEFAULT, IPL_HIGH);
2237 mutex_init(&p2->p_auxlock, MUTEX_DEFAULT, IPL_NONE);
2238 rw_init(&p2->p_reflock);
2239 cv_init(&p2->p_waitcv, "wait");
2240 cv_init(&p2->p_lwpcv, "lwpwait");
2241
2242 p2->p_lock = mutex_obj_alloc(MUTEX_DEFAULT, IPL_NONE);
2243
2244 kauth_proc_fork(p1, p2);
2245
2246 p2->p_raslist = NULL;
2247 p2->p_fd = fd_copy();
2248
2249 /* XXX racy */
2250 p2->p_mqueue_cnt = p1->p_mqueue_cnt;
2251
2252 p2->p_cwdi = cwdinit();
2253
2254 /*
2255 * Note: p_limit (rlimit stuff) is copy-on-write, so normally
2256 * we just need increase pl_refcnt.
2257 */
2258 if (!p1->p_limit->pl_writeable) {
2259 lim_addref(p1->p_limit);
2260 p2->p_limit = p1->p_limit;
2261 } else {
2262 p2->p_limit = lim_copy(p1->p_limit);
2263 }
2264
2265 p2->p_lflag = 0;
2266 p2->p_sflag = 0;
2267 p2->p_slflag = 0;
2268 p2->p_pptr = p1;
2269 p2->p_ppid = p1->p_pid;
2270 LIST_INIT(&p2->p_children);
2271
2272 p2->p_aio = NULL;
2273
2274 #ifdef KTRACE
2275 /*
2276 * Copy traceflag and tracefile if enabled.
2277 * If not inherited, these were zeroed above.
2278 */
2279 if (p1->p_traceflag & KTRFAC_INHERIT) {
2280 mutex_enter(&ktrace_lock);
2281 p2->p_traceflag = p1->p_traceflag;
2282 if ((p2->p_tracep = p1->p_tracep) != NULL)
2283 ktradref(p2);
2284 mutex_exit(&ktrace_lock);
2285 }
2286 #endif
2287
2288 /*
2289 * Create signal actions for the child process.
2290 */
2291 p2->p_sigacts = sigactsinit(p1, 0);
2292 mutex_enter(p1->p_lock);
2293 p2->p_sflag |=
2294 (p1->p_sflag & (PS_STOPFORK | PS_STOPEXEC | PS_NOCLDSTOP));
2295 sched_proc_fork(p1, p2);
2296 mutex_exit(p1->p_lock);
2297
2298 p2->p_stflag = p1->p_stflag;
2299
2300 /*
2301 * p_stats.
2302 * Copy parts of p_stats, and zero out the rest.
2303 */
2304 p2->p_stats = pstatscopy(p1->p_stats);
2305
2306 /* copy over machdep flags to the new proc */
2307 cpu_proc_fork(p1, p2);
2308
2309 /*
2310 * Prepare remaining parts of spawn data
2311 */
2312 spawn_data->sed_actions = fa;
2313 spawn_data->sed_attrs = sa;
2314
2315 spawn_data->sed_parent = p1;
2316
2317 /* create LWP */
2318 lwp_create(l1, p2, uaddr, 0, NULL, 0, spawn_return, spawn_data,
2319 &l2, l1->l_class);
2320 l2->l_ctxlink = NULL; /* reset ucontext link */
2321
2322 /*
2323 * Copy the credential so other references don't see our changes.
2324 * Test to see if this is necessary first, since in the common case
2325 * we won't need a private reference.
2326 */
2327 if (kauth_cred_geteuid(l2->l_cred) != kauth_cred_getsvuid(l2->l_cred) ||
2328 kauth_cred_getegid(l2->l_cred) != kauth_cred_getsvgid(l2->l_cred)) {
2329 l2->l_cred = kauth_cred_copy(l2->l_cred);
2330 kauth_cred_setsvuid(l2->l_cred, kauth_cred_geteuid(l2->l_cred));
2331 kauth_cred_setsvgid(l2->l_cred, kauth_cred_getegid(l2->l_cred));
2332 }
2333
2334 /* Update the master credentials. */
2335 if (l2->l_cred != p2->p_cred) {
2336 kauth_cred_t ocred;
2337
2338 kauth_cred_hold(l2->l_cred);
2339 mutex_enter(p2->p_lock);
2340 ocred = p2->p_cred;
2341 p2->p_cred = l2->l_cred;
2342 mutex_exit(p2->p_lock);
2343 kauth_cred_free(ocred);
2344 }
2345
2346 *child_ok = true;
2347 spawn_data->sed_refcnt = 2; /* child gets it as well */
2348 #if 0
2349 l2->l_nopreempt = 1; /* start it non-preemptable */
2350 #endif
2351
2352 /*
2353 * It's now safe for the scheduler and other processes to see the
2354 * child process.
2355 */
2356 mutex_enter(proc_lock);
2357
2358 if (p1->p_session->s_ttyvp != NULL && p1->p_lflag & PL_CONTROLT)
2359 p2->p_lflag |= PL_CONTROLT;
2360
2361 LIST_INSERT_HEAD(&p1->p_children, p2, p_sibling);
2362 p2->p_exitsig = SIGCHLD; /* signal for parent on exit */
2363
2364 LIST_INSERT_AFTER(p1, p2, p_pglist);
2365 LIST_INSERT_HEAD(&allproc, p2, p_list);
2366
2367 p2->p_trace_enabled = trace_is_enabled(p2);
2368 #ifdef __HAVE_SYSCALL_INTERN
2369 (*p2->p_emul->e_syscall_intern)(p2);
2370 #endif
2371
2372 /*
2373 * Make child runnable, set start time, and add to run queue except
2374 * if the parent requested the child to start in SSTOP state.
2375 */
2376 mutex_enter(p2->p_lock);
2377
2378 getmicrotime(&p2->p_stats->p_start);
2379
2380 lwp_lock(l2);
2381 KASSERT(p2->p_nrlwps == 1);
2382 p2->p_nrlwps = 1;
2383 p2->p_stat = SACTIVE;
2384 l2->l_stat = LSRUN;
2385 sched_enqueue(l2, false);
2386 lwp_unlock(l2);
2387
2388 mutex_exit(p2->p_lock);
2389 mutex_exit(proc_lock);
2390
2391 cv_wait(&spawn_data->sed_cv_child_ready, &spawn_data->sed_mtx_child);
2392 error = spawn_data->sed_error;
2393 mutex_exit(&spawn_data->sed_mtx_child);
2394 spawn_exec_data_release(spawn_data);
2395
2396 rw_exit(&p1->p_reflock);
2397 rw_exit(&exec_lock);
2398 have_exec_lock = false;
2399
2400 *pid_res = pid;
2401 return error;
2402
2403 error_exit:
2404 if (have_exec_lock) {
2405 execve_free_data(&spawn_data->sed_exec);
2406 rw_exit(&p1->p_reflock);
2407 rw_exit(&exec_lock);
2408 }
2409 mutex_exit(&spawn_data->sed_mtx_child);
2410 spawn_exec_data_release(spawn_data);
2411
2412 return error;
2413 }
2414
2415 int
2416 sys_posix_spawn(struct lwp *l1, const struct sys_posix_spawn_args *uap,
2417 register_t *retval)
2418 {
2419 /* {
2420 syscallarg(pid_t *) pid;
2421 syscallarg(const char *) path;
2422 syscallarg(const struct posix_spawn_file_actions *) file_actions;
2423 syscallarg(const struct posix_spawnattr *) attrp;
2424 syscallarg(char *const *) argv;
2425 syscallarg(char *const *) envp;
2426 } */
2427
2428 int error;
2429 struct posix_spawn_file_actions *fa = NULL;
2430 struct posix_spawnattr *sa = NULL;
2431 pid_t pid;
2432 bool child_ok = false;
2433
2434 error = check_posix_spawn(l1);
2435 if (error) {
2436 *retval = error;
2437 return 0;
2438 }
2439
2440 /* copy in file_actions struct */
2441 if (SCARG(uap, file_actions) != NULL) {
2442 error = posix_spawn_fa_alloc(&fa, SCARG(uap, file_actions));
2443 if (error)
2444 goto error_exit;
2445 }
2446
2447 /* copyin posix_spawnattr struct */
2448 if (SCARG(uap, attrp) != NULL) {
2449 sa = kmem_alloc(sizeof(*sa), KM_SLEEP);
2450 error = copyin(SCARG(uap, attrp), sa, sizeof(*sa));
2451 if (error)
2452 goto error_exit;
2453 }
2454
2455 /*
2456 * Do the spawn
2457 */
2458 error = do_posix_spawn(l1, &pid, &child_ok, SCARG(uap, path), fa, sa,
2459 SCARG(uap, argv), SCARG(uap, envp), execve_fetch_element);
2460 if (error)
2461 goto error_exit;
2462
2463 if (error == 0 && SCARG(uap, pid) != NULL)
2464 error = copyout(&pid, SCARG(uap, pid), sizeof(pid));
2465
2466 *retval = error;
2467 return 0;
2468
2469 error_exit:
2470 if (!child_ok) {
2471 (void)chgproccnt(kauth_cred_getuid(l1->l_cred), -1);
2472 atomic_dec_uint(&nprocs);
2473
2474 if (sa)
2475 kmem_free(sa, sizeof(*sa));
2476 if (fa)
2477 posix_spawn_fa_free(fa, fa->len);
2478 }
2479
2480 *retval = error;
2481 return 0;
2482 }
2483
2484 void
2485 exec_free_emul_arg(struct exec_package *epp)
2486 {
2487 if (epp->ep_emul_arg_free != NULL) {
2488 KASSERT(epp->ep_emul_arg != NULL);
2489 (*epp->ep_emul_arg_free)(epp->ep_emul_arg);
2490 epp->ep_emul_arg_free = NULL;
2491 epp->ep_emul_arg = NULL;
2492 } else {
2493 KASSERT(epp->ep_emul_arg == NULL);
2494 }
2495 }
2496