1/* $NetBSD: kern_exec.c,v 1.478 2019/07/05 17:14:48 maxv 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 1.478 2019/07/05 17:14:48 maxv 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/ptrace.h>
78#include <sys/mount.h>
79#include <sys/kmem.h>
80#include <sys/namei.h>
81#include <sys/vnode.h>
82#include <sys/file.h>
83#include <sys/filedesc.h>
84#include <sys/acct.h>
85#include <sys/atomic.h>
86#include <sys/exec.h>
87#include <sys/ktrace.h>
88#include <sys/uidinfo.h>
89#include <sys/wait.h>
90#include <sys/mman.h>
91#include <sys/ras.h>
92#include <sys/signalvar.h>
93#include <sys/stat.h>
94#include <sys/syscall.h>
95#include <sys/kauth.h>
96#include <sys/lwpctl.h>
97#include <sys/pax.h>
98#include <sys/cpu.h>
99#include <sys/module.h>
100#include <sys/syscallvar.h>
101#include <sys/syscallargs.h>
102#if NVERIEXEC > 0
103#include <sys/verified_exec.h>
104#endif /* NVERIEXEC > 0 */
105#include <sys/sdt.h>
106#include <sys/spawn.h>
107#include <sys/prot.h>
108#include <sys/cprng.h>
109
110#include <uvm/uvm_extern.h>
111
112#include <machine/reg.h>
113
114#include <compat/common/compat_util.h>
115
116#ifndef MD_TOPDOWN_INIT
117#ifdef __USE_TOPDOWN_VM
118#define MD_TOPDOWN_INIT(epp) (epp)->ep_flags |= EXEC_TOPDOWN_VM
119#else
120#define MD_TOPDOWN_INIT(epp)
121#endif
122#endif
123
124struct execve_data;
125
126extern int user_va0_disable;
127
128static size_t calcargs(struct execve_data * restrict, const size_t);
129static size_t calcstack(struct execve_data * restrict, const size_t);
130static int copyoutargs(struct execve_data * restrict, struct lwp *,
131 char * const);
132static int copyoutpsstrs(struct execve_data * restrict, struct proc *);
133static int copyinargs(struct execve_data * restrict, char * const *,
134 char * const *, execve_fetch_element_t, char **);
135static int copyinargstrs(struct execve_data * restrict, char * const *,
136 execve_fetch_element_t, char **, size_t *, void (*)(const void *, size_t));
137static int exec_sigcode_map(struct proc *, const struct emul *);
138
139#if defined(DEBUG) && !defined(DEBUG_EXEC)
140#define DEBUG_EXEC
141#endif
142#ifdef DEBUG_EXEC
143#define DPRINTF(a) printf a
144#define COPYPRINTF(s, a, b) printf("%s, %d: copyout%s @%p %zu\n", __func__, \
145 __LINE__, (s), (a), (b))
146static void dump_vmcmds(const struct exec_package * const, size_t, int);
147#define DUMPVMCMDS(p, x, e) do { dump_vmcmds((p), (x), (e)); } while (0)
148#else
149#define DPRINTF(a)
150#define COPYPRINTF(s, a, b)
151#define DUMPVMCMDS(p, x, e) do {} while (0)
152#endif /* DEBUG_EXEC */
153
154/*
155 * DTrace SDT provider definitions
156 */
157SDT_PROVIDER_DECLARE(proc);
158SDT_PROBE_DEFINE1(proc, kernel, , exec, "char *");
159SDT_PROBE_DEFINE1(proc, kernel, , exec__success, "char *");
160SDT_PROBE_DEFINE1(proc, kernel, , exec__failure, "int");
161
162/*
163 * Exec function switch:
164 *
165 * Note that each makecmds function is responsible for loading the
166 * exec package with the necessary functions for any exec-type-specific
167 * handling.
168 *
169 * Functions for specific exec types should be defined in their own
170 * header file.
171 */
172static const struct execsw **execsw = NULL;
173static int nexecs;
174
175u_int exec_maxhdrsz; /* must not be static - used by netbsd32 */
176
177/* list of dynamically loaded execsw entries */
178static LIST_HEAD(execlist_head, exec_entry) ex_head =
179 LIST_HEAD_INITIALIZER(ex_head);
180struct exec_entry {
181 LIST_ENTRY(exec_entry) ex_list;
182 SLIST_ENTRY(exec_entry) ex_slist;
183 const struct execsw *ex_sw;
184};
185
186#ifndef __HAVE_SYSCALL_INTERN
187void syscall(void);
188#endif
189
190/* NetBSD autoloadable syscalls */
191#ifdef MODULAR
192#include <kern/syscalls_autoload.c>
193#endif
194
195/* NetBSD emul struct */
196struct emul emul_netbsd = {
197 .e_name = "netbsd",
198#ifdef EMUL_NATIVEROOT
199 .e_path = EMUL_NATIVEROOT,
200#else
201 .e_path = NULL,
202#endif
203#ifndef __HAVE_MINIMAL_EMUL
204 .e_flags = EMUL_HAS_SYS___syscall,
205 .e_errno = NULL,
206 .e_nosys = SYS_syscall,
207 .e_nsysent = SYS_NSYSENT,
208#endif
209#ifdef MODULAR
210 .e_sc_autoload = netbsd_syscalls_autoload,
211#endif
212 .e_sysent = sysent,
213 .e_nomodbits = sysent_nomodbits,
214#ifdef SYSCALL_DEBUG
215 .e_syscallnames = syscallnames,
216#else
217 .e_syscallnames = NULL,
218#endif
219 .e_sendsig = sendsig,
220 .e_trapsignal = trapsignal,
221 .e_sigcode = NULL,
222 .e_esigcode = NULL,
223 .e_sigobject = NULL,
224 .e_setregs = setregs,
225 .e_proc_exec = NULL,
226 .e_proc_fork = NULL,
227 .e_proc_exit = NULL,
228 .e_lwp_fork = NULL,
229 .e_lwp_exit = NULL,
230#ifdef __HAVE_SYSCALL_INTERN
231 .e_syscall_intern = syscall_intern,
232#else
233 .e_syscall = syscall,
234#endif
235 .e_sysctlovly = NULL,
236 .e_vm_default_addr = uvm_default_mapaddr,
237 .e_usertrap = NULL,
238 .e_ucsize = sizeof(ucontext_t),
239 .e_startlwp = startlwp
240};
241
242/*
243 * Exec lock. Used to control access to execsw[] structures.
244 * This must not be static so that netbsd32 can access it, too.
245 */
246krwlock_t exec_lock;
247
248static kmutex_t sigobject_lock;
249
250/*
251 * Data used between a loadvm and execve part of an "exec" operation
252 */
253struct execve_data {
254 struct exec_package ed_pack;
255 struct pathbuf *ed_pathbuf;
256 struct vattr ed_attr;
257 struct ps_strings ed_arginfo;
258 char *ed_argp;
259 const char *ed_pathstring;
260 char *ed_resolvedpathbuf;
261 size_t ed_ps_strings_sz;
262 int ed_szsigcode;
263 size_t ed_argslen;
264 long ed_argc;
265 long ed_envc;
266};
267
268/*
269 * data passed from parent lwp to child during a posix_spawn()
270 */
271struct spawn_exec_data {
272 struct execve_data sed_exec;
273 struct posix_spawn_file_actions
274 *sed_actions;
275 struct posix_spawnattr *sed_attrs;
276 struct proc *sed_parent;
277 kcondvar_t sed_cv_child_ready;
278 kmutex_t sed_mtx_child;
279 int sed_error;
280 volatile uint32_t sed_refcnt;
281};
282
283static struct vm_map *exec_map;
284static struct pool exec_pool;
285
286static void *
287exec_pool_alloc(struct pool *pp, int flags)
288{
289
290 return (void *)uvm_km_alloc(exec_map, NCARGS, 0,
291 UVM_KMF_PAGEABLE | UVM_KMF_WAITVA);
292}
293
294static void
295exec_pool_free(struct pool *pp, void *addr)
296{
297
298 uvm_km_free(exec_map, (vaddr_t)addr, NCARGS, UVM_KMF_PAGEABLE);
299}
300
301static struct pool_allocator exec_palloc = {
302 .pa_alloc = exec_pool_alloc,
303 .pa_free = exec_pool_free,
304 .pa_pagesz = NCARGS
305};
306
307/*
308 * check exec:
309 * given an "executable" described in the exec package's namei info,
310 * see what we can do with it.
311 *
312 * ON ENTRY:
313 * exec package with appropriate namei info
314 * lwp pointer of exec'ing lwp
315 * NO SELF-LOCKED VNODES
316 *
317 * ON EXIT:
318 * error: nothing held, etc. exec header still allocated.
319 * ok: filled exec package, executable's vnode (unlocked).
320 *
321 * EXEC SWITCH ENTRY:
322 * Locked vnode to check, exec package, proc.
323 *
324 * EXEC SWITCH EXIT:
325 * ok: return 0, filled exec package, executable's vnode (unlocked).
326 * error: destructive:
327 * everything deallocated execept exec header.
328 * non-destructive:
329 * error code, executable's vnode (unlocked),
330 * exec header unmodified.
331 */
332int
333/*ARGSUSED*/
334check_exec(struct lwp *l, struct exec_package *epp, struct pathbuf *pb)
335{
336 int error, i;
337 struct vnode *vp;
338 struct nameidata nd;
339 size_t resid;
340
341#if 1
342 // grab the absolute pathbuf here before namei() trashes it.
343 pathbuf_copystring(pb, epp->ep_resolvedname, PATH_MAX);
344#endif
345 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF | TRYEMULROOT, pb);
346
347 /* first get the vnode */
348 if ((error = namei(&nd)) != 0)
349 return error;
350 epp->ep_vp = vp = nd.ni_vp;
351#if 0
352 /*
353 * XXX: can't use nd.ni_pnbuf, because although pb contains an
354 * absolute path, nd.ni_pnbuf does not if the path contains symlinks.
355 */
356 /* normally this can't fail */
357 error = copystr(nd.ni_pnbuf, epp->ep_resolvedname, PATH_MAX, NULL);
358 KASSERT(error == 0);
359#endif
360
361#ifdef DIAGNOSTIC
362 /* paranoia (take this out once namei stuff stabilizes) */
363 memset(nd.ni_pnbuf, '~', PATH_MAX);
364#endif
365
366 /* check access and type */
367 if (vp->v_type != VREG) {
368 error = EACCES;
369 goto bad1;
370 }
371 if ((error = VOP_ACCESS(vp, VEXEC, l->l_cred)) != 0)
372 goto bad1;
373
374 /* get attributes */
375 if ((error = VOP_GETATTR(vp, epp->ep_vap, l->l_cred)) != 0)
376 goto bad1;
377
378 /* Check mount point */
379 if (vp->v_mount->mnt_flag & MNT_NOEXEC) {
380 error = EACCES;
381 goto bad1;
382 }
383 if (vp->v_mount->mnt_flag & MNT_NOSUID)
384 epp->ep_vap->va_mode &= ~(S_ISUID | S_ISGID);
385
386 /* try to open it */
387 if ((error = VOP_OPEN(vp, FREAD, l->l_cred)) != 0)
388 goto bad1;
389
390 /* unlock vp, since we need it unlocked from here on out. */
391 VOP_UNLOCK(vp);
392
393#if NVERIEXEC > 0
394 error = veriexec_verify(l, vp, epp->ep_resolvedname,
395 epp->ep_flags & EXEC_INDIR ? VERIEXEC_INDIRECT : VERIEXEC_DIRECT,
396 NULL);
397 if (error)
398 goto bad2;
399#endif /* NVERIEXEC > 0 */
400
401#ifdef PAX_SEGVGUARD
402 error = pax_segvguard(l, vp, epp->ep_resolvedname, false);
403 if (error)
404 goto bad2;
405#endif /* PAX_SEGVGUARD */
406
407 /* now we have the file, get the exec header */
408 error = vn_rdwr(UIO_READ, vp, epp->ep_hdr, epp->ep_hdrlen, 0,
409 UIO_SYSSPACE, 0, l->l_cred, &resid, NULL);
410 if (error)
411 goto bad2;
412 epp->ep_hdrvalid = epp->ep_hdrlen - resid;
413
414 /*
415 * Set up default address space limits. Can be overridden
416 * by individual exec packages.
417 */
418 epp->ep_vm_minaddr = exec_vm_minaddr(VM_MIN_ADDRESS);
419 epp->ep_vm_maxaddr = VM_MAXUSER_ADDRESS;
420
421 /*
422 * set up the vmcmds for creation of the process
423 * address space
424 */
425 error = ENOEXEC;
426 for (i = 0; i < nexecs; i++) {
427 int newerror;
428
429 epp->ep_esch = execsw[i];
430 newerror = (*execsw[i]->es_makecmds)(l, epp);
431
432 if (!newerror) {
433 /* Seems ok: check that entry point is not too high */
434 if (epp->ep_entry >= epp->ep_vm_maxaddr) {
435#ifdef DIAGNOSTIC
436 printf("%s: rejecting %p due to "
437 "too high entry address (>= %p)\n",
438 __func__, (void *)epp->ep_entry,
439 (void *)epp->ep_vm_maxaddr);
440#endif
441 error = ENOEXEC;
442 break;
443 }
444 /* Seems ok: check that entry point is not too low */
445 if (epp->ep_entry < epp->ep_vm_minaddr) {
446#ifdef DIAGNOSTIC
447 printf("%s: rejecting %p due to "
448 "too low entry address (< %p)\n",
449 __func__, (void *)epp->ep_entry,
450 (void *)epp->ep_vm_minaddr);
451#endif
452 error = ENOEXEC;
453 break;
454 }
455
456 /* check limits */
457 if ((epp->ep_tsize > MAXTSIZ) ||
458 (epp->ep_dsize > (u_quad_t)l->l_proc->p_rlimit
459 [RLIMIT_DATA].rlim_cur)) {
460#ifdef DIAGNOSTIC
461 printf("%s: rejecting due to "
462 "limits (t=%llu > %llu || d=%llu > %llu)\n",
463 __func__,
464 (unsigned long long)epp->ep_tsize,
465 (unsigned long long)MAXTSIZ,
466 (unsigned long long)epp->ep_dsize,
467 (unsigned long long)
468 l->l_proc->p_rlimit[RLIMIT_DATA].rlim_cur);
469#endif
470 error = ENOMEM;
471 break;
472 }
473 return 0;
474 }
475
476 /*
477 * Reset all the fields that may have been modified by the
478 * loader.
479 */
480 KASSERT(epp->ep_emul_arg == NULL);
481 if (epp->ep_emul_root != NULL) {
482 vrele(epp->ep_emul_root);
483 epp->ep_emul_root = NULL;
484 }
485 if (epp->ep_interp != NULL) {
486 vrele(epp->ep_interp);
487 epp->ep_interp = NULL;
488 }
489 epp->ep_pax_flags = 0;
490
491 /* make sure the first "interesting" error code is saved. */
492 if (error == ENOEXEC)
493 error = newerror;
494
495 if (epp->ep_flags & EXEC_DESTR)
496 /* Error from "#!" code, tidied up by recursive call */
497 return error;
498 }
499
500 /* not found, error */
501
502 /*
503 * free any vmspace-creation commands,
504 * and release their references
505 */
506 kill_vmcmds(&epp->ep_vmcmds);
507
508bad2:
509 /*
510 * close and release the vnode, restore the old one, free the
511 * pathname buf, and punt.
512 */
513 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
514 VOP_CLOSE(vp, FREAD, l->l_cred);
515 vput(vp);
516 return error;
517
518bad1:
519 /*
520 * free the namei pathname buffer, and put the vnode
521 * (which we don't yet have open).
522 */
523 vput(vp); /* was still locked */
524 return error;
525}
526
527#ifdef __MACHINE_STACK_GROWS_UP
528#define STACK_PTHREADSPACE NBPG
529#else
530#define STACK_PTHREADSPACE 0
531#endif
532
533static int
534execve_fetch_element(char * const *array, size_t index, char **value)
535{
536 return copyin(array + index, value, sizeof(*value));
537}
538
539/*
540 * exec system call
541 */
542int
543sys_execve(struct lwp *l, const struct sys_execve_args *uap, register_t *retval)
544{
545 /* {
546 syscallarg(const char *) path;
547 syscallarg(char * const *) argp;
548 syscallarg(char * const *) envp;
549 } */
550
551 return execve1(l, SCARG(uap, path), SCARG(uap, argp),
552 SCARG(uap, envp), execve_fetch_element);
553}
554
555int
556sys_fexecve(struct lwp *l, const struct sys_fexecve_args *uap,
557 register_t *retval)
558{
559 /* {
560 syscallarg(int) fd;
561 syscallarg(char * const *) argp;
562 syscallarg(char * const *) envp;
563 } */
564
565 return ENOSYS;
566}
567
568/*
569 * Load modules to try and execute an image that we do not understand.
570 * If no execsw entries are present, we load those likely to be needed
571 * in order to run native images only. Otherwise, we autoload all
572 * possible modules that could let us run the binary. XXX lame
573 */
574static void
575exec_autoload(void)
576{
577#ifdef MODULAR
578 static const char * const native[] = {
579 "exec_elf32",
580 "exec_elf64",
581 "exec_script",
582 NULL
583 };
584 static const char * const compat[] = {
585 "exec_elf32",
586 "exec_elf64",
587 "exec_script",
588 "exec_aout",
589 "exec_coff",
590 "exec_ecoff",
591 "compat_aoutm68k",
592 "compat_netbsd32",
593 "compat_sunos",
594 "compat_sunos32",
595 "compat_ultrix",
596 NULL
597 };
598 char const * const *list;
599 int i;
600
601 list = (nexecs == 0 ? native : compat);
602 for (i = 0; list[i] != NULL; i++) {
603 if (module_autoload(list[i], MODULE_CLASS_EXEC) != 0) {
604 continue;
605 }
606 yield();
607 }
608#endif
609}
610
611/*
612 * Copy the user or kernel supplied upath to the allocated pathbuffer pbp
613 * making it absolute in the process, by prepending the current working
614 * directory if it is not. If offs is supplied it will contain the offset
615 * where the original supplied copy of upath starts.
616 */
617int
618exec_makepathbuf(struct lwp *l, const char *upath, enum uio_seg seg,
619 struct pathbuf **pbp, size_t *offs)
620{
621 char *path, *bp;
622 size_t len, tlen;
623 int error;
624 struct cwdinfo *cwdi;
625
626 path = PNBUF_GET();
627 if (seg == UIO_SYSSPACE) {
628 error = copystr(upath, path, MAXPATHLEN, &len);
629 } else {
630 error = copyinstr(upath, path, MAXPATHLEN, &len);
631 }
632 if (error)
633 goto err;
634
635 if (path[0] == '/') {
636 if (offs)
637 *offs = 0;
638 goto out;
639 }
640
641 len++;
642 if (len + 1 >= MAXPATHLEN) {
643 error = ENAMETOOLONG;
644 goto err;
645 }
646 bp = path + MAXPATHLEN - len;
647 memmove(bp, path, len);
648 *(--bp) = '/';
649
650 cwdi = l->l_proc->p_cwdi;
651 rw_enter(&cwdi->cwdi_lock, RW_READER);
652 error = getcwd_common(cwdi->cwdi_cdir, NULL, &bp, path, MAXPATHLEN / 2,
653 GETCWD_CHECK_ACCESS, l);
654 rw_exit(&cwdi->cwdi_lock);
655
656 if (error)
657 goto err;
658 tlen = path + MAXPATHLEN - bp;
659
660 memmove(path, bp, tlen);
661 path[tlen - 1] = '\0';
662 if (offs)
663 *offs = tlen - len;
664out:
665 *pbp = pathbuf_assimilate(path);
666 return 0;
667err:
668 PNBUF_PUT(path);
669 return error;
670}
671
672vaddr_t
673exec_vm_minaddr(vaddr_t va_min)
674{
675 /*
676 * Increase va_min if we don't want NULL to be mappable by the
677 * process.
678 */
679#define VM_MIN_GUARD PAGE_SIZE
680 if (user_va0_disable && (va_min < VM_MIN_GUARD))
681 return VM_MIN_GUARD;
682 return va_min;
683}
684
685static int
686execve_loadvm(struct lwp *l, const char *path, char * const *args,
687 char * const *envs, execve_fetch_element_t fetch_element,
688 struct execve_data * restrict data)
689{
690 struct exec_package * const epp = &data->ed_pack;
691 int error;
692 struct proc *p;
693 char *dp;
694 u_int modgen;
695 size_t offs;
696
697 KASSERT(data != NULL);
698
699 p = l->l_proc;
700 modgen = 0;
701
702 SDT_PROBE(proc, kernel, , exec, path, 0, 0, 0, 0);
703
704 /*
705 * Check if we have exceeded our number of processes limit.
706 * This is so that we handle the case where a root daemon
707 * forked, ran setuid to become the desired user and is trying
708 * to exec. The obvious place to do the reference counting check
709 * is setuid(), but we don't do the reference counting check there
710 * like other OS's do because then all the programs that use setuid()
711 * must be modified to check the return code of setuid() and exit().
712 * It is dangerous to make setuid() fail, because it fails open and
713 * the program will continue to run as root. If we make it succeed
714 * and return an error code, again we are not enforcing the limit.
715 * The best place to enforce the limit is here, when the process tries
716 * to execute a new image, because eventually the process will need
717 * to call exec in order to do something useful.
718 */
719 retry:
720 if (p->p_flag & PK_SUGID) {
721 if (kauth_authorize_process(l->l_cred, KAUTH_PROCESS_RLIMIT,
722 p, KAUTH_ARG(KAUTH_REQ_PROCESS_RLIMIT_BYPASS),
723 &p->p_rlimit[RLIMIT_NPROC],
724 KAUTH_ARG(RLIMIT_NPROC)) != 0 &&
725 chgproccnt(kauth_cred_getuid(l->l_cred), 0) >
726 p->p_rlimit[RLIMIT_NPROC].rlim_cur)
727 return EAGAIN;
728 }
729
730 /*
731 * Drain existing references and forbid new ones. The process
732 * should be left alone until we're done here. This is necessary
733 * to avoid race conditions - e.g. in ptrace() - that might allow
734 * a local user to illicitly obtain elevated privileges.
735 */
736 rw_enter(&p->p_reflock, RW_WRITER);
737
738 /*
739 * Init the namei data to point the file user's program name.
740 * This is done here rather than in check_exec(), so that it's
741 * possible to override this settings if any of makecmd/probe
742 * functions call check_exec() recursively - for example,
743 * see exec_script_makecmds().
744 */
745 if ((error = exec_makepathbuf(l, path, UIO_USERSPACE,
746 &data->ed_pathbuf, &offs)) != 0)
747 goto clrflg;
748 data->ed_pathstring = pathbuf_stringcopy_get(data->ed_pathbuf);
749 data->ed_resolvedpathbuf = PNBUF_GET();
750
751 /*
752 * initialize the fields of the exec package.
753 */
754 epp->ep_kname = data->ed_pathstring + offs;
755 epp->ep_resolvedname = data->ed_resolvedpathbuf;
756 epp->ep_hdr = kmem_alloc(exec_maxhdrsz, KM_SLEEP);
757 epp->ep_hdrlen = exec_maxhdrsz;
758 epp->ep_hdrvalid = 0;
759 epp->ep_emul_arg = NULL;
760 epp->ep_emul_arg_free = NULL;
761 memset(&epp->ep_vmcmds, 0, sizeof(epp->ep_vmcmds));
762 epp->ep_vap = &data->ed_attr;
763 epp->ep_flags = (p->p_flag & PK_32) ? EXEC_FROM32 : 0;
764 MD_TOPDOWN_INIT(epp);
765 epp->ep_emul_root = NULL;
766 epp->ep_interp = NULL;
767 epp->ep_esch = NULL;
768 epp->ep_pax_flags = 0;
769 memset(epp->ep_machine_arch, 0, sizeof(epp->ep_machine_arch));
770
771 rw_enter(&exec_lock, RW_READER);
772
773 /* see if we can run it. */
774 if ((error = check_exec(l, epp, data->ed_pathbuf)) != 0) {
775 if (error != ENOENT && error != EACCES && error != ENOEXEC) {
776 DPRINTF(("%s: check exec failed for %s, error %d\n",
777 __func__, epp->ep_kname, error));
778 }
779 goto freehdr;
780 }
781
782 /* allocate an argument buffer */
783 data->ed_argp = pool_get(&exec_pool, PR_WAITOK);
784 KASSERT(data->ed_argp != NULL);
785 dp = data->ed_argp;
786
787 if ((error = copyinargs(data, args, envs, fetch_element, &dp)) != 0) {
788 goto bad;
789 }
790
791 /*
792 * Calculate the new stack size.
793 */
794
795#ifdef __MACHINE_STACK_GROWS_UP
796/*
797 * copyargs() fills argc/argv/envp from the lower address even on
798 * __MACHINE_STACK_GROWS_UP machines. Reserve a few words just below the SP
799 * so that _rtld() use it.
800 */
801#define RTLD_GAP 32
802#else
803#define RTLD_GAP 0
804#endif
805
806 const size_t argenvstrlen = (char *)ALIGN(dp) - data->ed_argp;
807
808 data->ed_argslen = calcargs(data, argenvstrlen);
809
810 const size_t len = calcstack(data, pax_aslr_stack_gap(epp) + RTLD_GAP);
811
812 if (len > epp->ep_ssize) {
813 /* in effect, compare to initial limit */
814 DPRINTF(("%s: stack limit exceeded %zu\n", __func__, len));
815 error = ENOMEM;
816 goto bad;
817 }
818 /* adjust "active stack depth" for process VSZ */
819 epp->ep_ssize = len;
820
821 return 0;
822
823 bad:
824 /* free the vmspace-creation commands, and release their references */
825 kill_vmcmds(&epp->ep_vmcmds);
826 /* kill any opened file descriptor, if necessary */
827 if (epp->ep_flags & EXEC_HASFD) {
828 epp->ep_flags &= ~EXEC_HASFD;
829 fd_close(epp->ep_fd);
830 }
831 /* close and put the exec'd file */
832 vn_lock(epp->ep_vp, LK_EXCLUSIVE | LK_RETRY);
833 VOP_CLOSE(epp->ep_vp, FREAD, l->l_cred);
834 vput(epp->ep_vp);
835 pool_put(&exec_pool, data->ed_argp);
836
837 freehdr:
838 kmem_free(epp->ep_hdr, epp->ep_hdrlen);
839 if (epp->ep_emul_root != NULL)
840 vrele(epp->ep_emul_root);
841 if (epp->ep_interp != NULL)
842 vrele(epp->ep_interp);
843
844 rw_exit(&exec_lock);
845
846 pathbuf_stringcopy_put(data->ed_pathbuf, data->ed_pathstring);
847 pathbuf_destroy(data->ed_pathbuf);
848 PNBUF_PUT(data->ed_resolvedpathbuf);
849
850 clrflg:
851 rw_exit(&p->p_reflock);
852
853 if (modgen != module_gen && error == ENOEXEC) {
854 modgen = module_gen;
855 exec_autoload();
856 goto retry;
857 }
858
859 SDT_PROBE(proc, kernel, , exec__failure, error, 0, 0, 0, 0);
860 return error;
861}
862
863static int
864execve_dovmcmds(struct lwp *l, struct execve_data * restrict data)
865{
866 struct exec_package * const epp = &data->ed_pack;
867 struct proc *p = l->l_proc;
868 struct exec_vmcmd *base_vcp;
869 int error = 0;
870 size_t i;
871
872 /* record proc's vnode, for use by procfs and others */
873 if (p->p_textvp)
874 vrele(p->p_textvp);
875 vref(epp->ep_vp);
876 p->p_textvp = epp->ep_vp;
877
878 /* create the new process's VM space by running the vmcmds */
879 KASSERTMSG(epp->ep_vmcmds.evs_used != 0, "%s: no vmcmds", __func__);
880
881#ifdef TRACE_EXEC
882 DUMPVMCMDS(epp, 0, 0);
883#endif
884
885 base_vcp = NULL;
886
887 for (i = 0; i < epp->ep_vmcmds.evs_used && !error; i++) {
888 struct exec_vmcmd *vcp;
889
890 vcp = &epp->ep_vmcmds.evs_cmds[i];
891 if (vcp->ev_flags & VMCMD_RELATIVE) {
892 KASSERTMSG(base_vcp != NULL,
893 "%s: relative vmcmd with no base", __func__);
894 KASSERTMSG((vcp->ev_flags & VMCMD_BASE) == 0,
895 "%s: illegal base & relative vmcmd", __func__);
896 vcp->ev_addr += base_vcp->ev_addr;
897 }
898 error = (*vcp->ev_proc)(l, vcp);
899 if (error)
900 DUMPVMCMDS(epp, i, error);
901 if (vcp->ev_flags & VMCMD_BASE)
902 base_vcp = vcp;
903 }
904
905 /* free the vmspace-creation commands, and release their references */
906 kill_vmcmds(&epp->ep_vmcmds);
907
908 vn_lock(epp->ep_vp, LK_EXCLUSIVE | LK_RETRY);
909 VOP_CLOSE(epp->ep_vp, FREAD, l->l_cred);
910 vput(epp->ep_vp);
911
912 /* if an error happened, deallocate and punt */
913 if (error != 0) {
914 DPRINTF(("%s: vmcmd %zu failed: %d\n", __func__, i - 1, error));
915 }
916 return error;
917}
918
919static void
920execve_free_data(struct execve_data *data)
921{
922 struct exec_package * const epp = &data->ed_pack;
923
924 /* free the vmspace-creation commands, and release their references */
925 kill_vmcmds(&epp->ep_vmcmds);
926 /* kill any opened file descriptor, if necessary */
927 if (epp->ep_flags & EXEC_HASFD) {
928 epp->ep_flags &= ~EXEC_HASFD;
929 fd_close(epp->ep_fd);
930 }
931
932 /* close and put the exec'd file */
933 vn_lock(epp->ep_vp, LK_EXCLUSIVE | LK_RETRY);
934 VOP_CLOSE(epp->ep_vp, FREAD, curlwp->l_cred);
935 vput(epp->ep_vp);
936 pool_put(&exec_pool, data->ed_argp);
937
938 kmem_free(epp->ep_hdr, epp->ep_hdrlen);
939 if (epp->ep_emul_root != NULL)
940 vrele(epp->ep_emul_root);
941 if (epp->ep_interp != NULL)
942 vrele(epp->ep_interp);
943
944 pathbuf_stringcopy_put(data->ed_pathbuf, data->ed_pathstring);
945 pathbuf_destroy(data->ed_pathbuf);
946 PNBUF_PUT(data->ed_resolvedpathbuf);
947}
948
949static void
950pathexec(struct proc *p, const char *resolvedname)
951{
952 KASSERT(resolvedname[0] == '/');
953
954 /* set command name & other accounting info */
955 strlcpy(p->p_comm, strrchr(resolvedname, '/') + 1, sizeof(p->p_comm));
956
957 kmem_strfree(p->p_path);
958 p->p_path = kmem_strdupsize(resolvedname, NULL, KM_SLEEP);
959}
960
961/* XXX elsewhere */
962static int
963credexec(struct lwp *l, struct vattr *attr)
964{
965 struct proc *p = l->l_proc;
966 int error;
967
968 /*
969 * Deal with set[ug]id. MNT_NOSUID has already been used to disable
970 * s[ug]id. It's OK to check for PSL_TRACED here as we have blocked
971 * out additional references on the process for the moment.
972 */
973 if ((p->p_slflag & PSL_TRACED) == 0 &&
974
975 (((attr->va_mode & S_ISUID) != 0 &&
976 kauth_cred_geteuid(l->l_cred) != attr->va_uid) ||
977
978 ((attr->va_mode & S_ISGID) != 0 &&
979 kauth_cred_getegid(l->l_cred) != attr->va_gid))) {
980 /*
981 * Mark the process as SUGID before we do
982 * anything that might block.
983 */
984 proc_crmod_enter();
985 proc_crmod_leave(NULL, NULL, true);
986
987 /* Make sure file descriptors 0..2 are in use. */
988 if ((error = fd_checkstd()) != 0) {
989 DPRINTF(("%s: fdcheckstd failed %d\n",
990 __func__, error));
991 return error;
992 }
993
994 /*
995 * Copy the credential so other references don't see our
996 * changes.
997 */
998 l->l_cred = kauth_cred_copy(l->l_cred);
999#ifdef KTRACE
1000 /*
1001 * If the persistent trace flag isn't set, turn off.
1002 */
1003 if (p->p_tracep) {
1004 mutex_enter(&ktrace_lock);
1005 if (!(p->p_traceflag & KTRFAC_PERSISTENT))
1006 ktrderef(p);
1007 mutex_exit(&ktrace_lock);
1008 }
1009#endif
1010 if (attr->va_mode & S_ISUID)
1011 kauth_cred_seteuid(l->l_cred, attr->va_uid);
1012 if (attr->va_mode & S_ISGID)
1013 kauth_cred_setegid(l->l_cred, attr->va_gid);
1014 } else {
1015 if (kauth_cred_geteuid(l->l_cred) ==
1016 kauth_cred_getuid(l->l_cred) &&
1017 kauth_cred_getegid(l->l_cred) ==
1018 kauth_cred_getgid(l->l_cred))
1019 p->p_flag &= ~PK_SUGID;
1020 }
1021
1022 /*
1023 * Copy the credential so other references don't see our changes.
1024 * Test to see if this is necessary first, since in the common case
1025 * we won't need a private reference.
1026 */
1027 if (kauth_cred_geteuid(l->l_cred) != kauth_cred_getsvuid(l->l_cred) ||
1028 kauth_cred_getegid(l->l_cred) != kauth_cred_getsvgid(l->l_cred)) {
1029 l->l_cred = kauth_cred_copy(l->l_cred);
1030 kauth_cred_setsvuid(l->l_cred, kauth_cred_geteuid(l->l_cred));
1031 kauth_cred_setsvgid(l->l_cred, kauth_cred_getegid(l->l_cred));
1032 }
1033
1034 /* Update the master credentials. */
1035 if (l->l_cred != p->p_cred) {
1036 kauth_cred_t ocred;
1037
1038 kauth_cred_hold(l->l_cred);
1039 mutex_enter(p->p_lock);
1040 ocred = p->p_cred;
1041 p->p_cred = l->l_cred;
1042 mutex_exit(p->p_lock);
1043 kauth_cred_free(ocred);
1044 }
1045
1046 return 0;
1047}
1048
1049static void
1050emulexec(struct lwp *l, struct exec_package *epp)
1051{
1052 struct proc *p = l->l_proc;
1053
1054 /* The emulation root will usually have been found when we looked
1055 * for the elf interpreter (or similar), if not look now. */
1056 if (epp->ep_esch->es_emul->e_path != NULL &&
1057 epp->ep_emul_root == NULL)
1058 emul_find_root(l, epp);
1059
1060 /* Any old emulation root got removed by fdcloseexec */
1061 rw_enter(&p->p_cwdi->cwdi_lock, RW_WRITER);
1062 p->p_cwdi->cwdi_edir = epp->ep_emul_root;
1063 rw_exit(&p->p_cwdi->cwdi_lock);
1064 epp->ep_emul_root = NULL;
1065 if (epp->ep_interp != NULL)
1066 vrele(epp->ep_interp);
1067
1068 /*
1069 * Call emulation specific exec hook. This can setup per-process
1070 * p->p_emuldata or do any other per-process stuff an emulation needs.
1071 *
1072 * If we are executing process of different emulation than the
1073 * original forked process, call e_proc_exit() of the old emulation
1074 * first, then e_proc_exec() of new emulation. If the emulation is
1075 * same, the exec hook code should deallocate any old emulation
1076 * resources held previously by this process.
1077 */
1078 if (p->p_emul && p->p_emul->e_proc_exit
1079 && p->p_emul != epp->ep_esch->es_emul)
1080 (*p->p_emul->e_proc_exit)(p);
1081
1082 /*
1083 * This is now LWP 1.
1084 */
1085 /* XXX elsewhere */
1086 mutex_enter(p->p_lock);
1087 p->p_nlwpid = 1;
1088 l->l_lid = 1;
1089 mutex_exit(p->p_lock);
1090
1091 /*
1092 * Call exec hook. Emulation code may NOT store reference to anything
1093 * from &pack.
1094 */
1095 if (epp->ep_esch->es_emul->e_proc_exec)
1096 (*epp->ep_esch->es_emul->e_proc_exec)(p, epp);
1097
1098 /* update p_emul, the old value is no longer needed */
1099 p->p_emul = epp->ep_esch->es_emul;
1100
1101 /* ...and the same for p_execsw */
1102 p->p_execsw = epp->ep_esch;
1103
1104#ifdef __HAVE_SYSCALL_INTERN
1105 (*p->p_emul->e_syscall_intern)(p);
1106#endif
1107 ktremul();
1108}
1109
1110static int
1111execve_runproc(struct lwp *l, struct execve_data * restrict data,
1112 bool no_local_exec_lock, bool is_spawn)
1113{
1114 struct exec_package * const epp = &data->ed_pack;
1115 int error = 0;
1116 struct proc *p;
1117
1118 /*
1119 * In case of a posix_spawn operation, the child doing the exec
1120 * might not hold the reader lock on exec_lock, but the parent
1121 * will do this instead.
1122 */
1123 KASSERT(no_local_exec_lock || rw_lock_held(&exec_lock));
1124 KASSERT(!no_local_exec_lock || is_spawn);
1125 KASSERT(data != NULL);
1126
1127 p = l->l_proc;
1128
1129 /* Get rid of other LWPs. */
1130 if (p->p_nlwps > 1) {
1131 mutex_enter(p->p_lock);
1132 exit_lwps(l);
1133 mutex_exit(p->p_lock);
1134 }
1135 KDASSERT(p->p_nlwps == 1);
1136
1137 /* Destroy any lwpctl info. */
1138 if (p->p_lwpctl != NULL)
1139 lwp_ctl_exit();
1140
1141 /* Remove POSIX timers */
1142 timers_free(p, TIMERS_POSIX);
1143
1144 /* Set the PaX flags. */
1145 pax_set_flags(epp, p);
1146
1147 /*
1148 * Do whatever is necessary to prepare the address space
1149 * for remapping. Note that this might replace the current
1150 * vmspace with another!
1151 */
1152 if (is_spawn)
1153 uvmspace_spawn(l, epp->ep_vm_minaddr,
1154 epp->ep_vm_maxaddr,
1155 epp->ep_flags & EXEC_TOPDOWN_VM);
1156 else
1157 uvmspace_exec(l, epp->ep_vm_minaddr,
1158 epp->ep_vm_maxaddr,
1159 epp->ep_flags & EXEC_TOPDOWN_VM);
1160
1161 struct vmspace *vm;
1162 vm = p->p_vmspace;
1163 vm->vm_taddr = (void *)epp->ep_taddr;
1164 vm->vm_tsize = btoc(epp->ep_tsize);
1165 vm->vm_daddr = (void*)epp->ep_daddr;
1166 vm->vm_dsize = btoc(epp->ep_dsize);
1167 vm->vm_ssize = btoc(epp->ep_ssize);
1168 vm->vm_issize = 0;
1169 vm->vm_maxsaddr = (void *)epp->ep_maxsaddr;
1170 vm->vm_minsaddr = (void *)epp->ep_minsaddr;
1171
1172 pax_aslr_init_vm(l, vm, epp);
1173
1174 /* Now map address space. */
1175 error = execve_dovmcmds(l, data);
1176 if (error != 0)
1177 goto exec_abort;
1178
1179 pathexec(p, epp->ep_resolvedname);
1180
1181 char * const newstack = STACK_GROW(vm->vm_minsaddr, epp->ep_ssize);
1182
1183 error = copyoutargs(data, l, newstack);
1184 if (error != 0)
1185 goto exec_abort;
1186
1187 cwdexec(p);
1188 fd_closeexec(); /* handle close on exec */
1189
1190 if (__predict_false(ktrace_on))
1191 fd_ktrexecfd();
1192
1193 execsigs(p); /* reset caught signals */
1194
1195 mutex_enter(p->p_lock);
1196 l->l_ctxlink = NULL; /* reset ucontext link */
1197 p->p_acflag &= ~AFORK;
1198 p->p_flag |= PK_EXEC;
1199 mutex_exit(p->p_lock);
1200
1201 /*
1202 * Stop profiling.
1203 */
1204 if ((p->p_stflag & PST_PROFIL) != 0) {
1205 mutex_spin_enter(&p->p_stmutex);
1206 stopprofclock(p);
1207 mutex_spin_exit(&p->p_stmutex);
1208 }
1209
1210 /*
1211 * It's OK to test PL_PPWAIT unlocked here, as other LWPs have
1212 * exited and exec()/exit() are the only places it will be cleared.
1213 */
1214 if ((p->p_lflag & PL_PPWAIT) != 0) {
1215 lwp_t *lp;
1216
1217 mutex_enter(proc_lock);
1218 lp = p->p_vforklwp;
1219 p->p_vforklwp = NULL;
1220
1221 l->l_lwpctl = NULL; /* was on loan from blocked parent */
1222 p->p_lflag &= ~PL_PPWAIT;
1223 lp->l_vforkwaiting = false;
1224
1225 cv_broadcast(&lp->l_waitcv);
1226 mutex_exit(proc_lock);
1227 }
1228
1229 error = credexec(l, &data->ed_attr);
1230 if (error)
1231 goto exec_abort;
1232
1233#if defined(__HAVE_RAS)
1234 /*
1235 * Remove all RASs from the address space.
1236 */
1237 ras_purgeall();
1238#endif
1239
1240 doexechooks(p);
1241
1242 /*
1243 * Set initial SP at the top of the stack.
1244 *
1245 * Note that on machines where stack grows up (e.g. hppa), SP points to
1246 * the end of arg/env strings. Userland guesses the address of argc
1247 * via ps_strings::ps_argvstr.
1248 */
1249
1250 /* Setup new registers and do misc. setup. */
1251 (*epp->ep_esch->es_emul->e_setregs)(l, epp, (vaddr_t)newstack);
1252 if (epp->ep_esch->es_setregs)
1253 (*epp->ep_esch->es_setregs)(l, epp, (vaddr_t)newstack);
1254
1255 /* Provide a consistent LWP private setting */
1256 (void)lwp_setprivate(l, NULL);
1257
1258 /* Discard all PCU state; need to start fresh */
1259 pcu_discard_all(l);
1260
1261 /* map the process's signal trampoline code */
1262 if ((error = exec_sigcode_map(p, epp->ep_esch->es_emul)) != 0) {
1263 DPRINTF(("%s: map sigcode failed %d\n", __func__, error));
1264 goto exec_abort;
1265 }
1266
1267 pool_put(&exec_pool, data->ed_argp);
1268
1269 /* notify others that we exec'd */
1270 KNOTE(&p->p_klist, NOTE_EXEC);
1271
1272 kmem_free(epp->ep_hdr, epp->ep_hdrlen);
1273
1274 SDT_PROBE(proc, kernel, , exec__success, epp->ep_kname, 0, 0, 0, 0);
1275
1276 emulexec(l, epp);
1277
1278 /* Allow new references from the debugger/procfs. */
1279 rw_exit(&p->p_reflock);
1280 if (!no_local_exec_lock)
1281 rw_exit(&exec_lock);
1282
1283 mutex_enter(proc_lock);
1284
1285 /* posix_spawn(3) reports a single event with implied exec(3) */
1286 if ((p->p_slflag & PSL_TRACED) && !is_spawn) {
1287 mutex_enter(p->p_lock);
1288 eventswitch(TRAP_EXEC);
1289 mutex_enter(proc_lock);
1290 }
1291
1292 if (p->p_sflag & PS_STOPEXEC) {
1293 ksiginfoq_t kq;
1294
1295 KERNEL_UNLOCK_ALL(l, &l->l_biglocks);
1296 p->p_pptr->p_nstopchild++;
1297 p->p_waited = 0;
1298 mutex_enter(p->p_lock);
1299 ksiginfo_queue_init(&kq);
1300 sigclearall(p, &contsigmask, &kq);
1301 lwp_lock(l);
1302 l->l_stat = LSSTOP;
1303 p->p_stat = SSTOP;
1304 p->p_nrlwps--;
1305 lwp_unlock(l);
1306 mutex_exit(p->p_lock);
1307 mutex_exit(proc_lock);
1308 lwp_lock(l);
1309 mi_switch(l);
1310 ksiginfo_queue_drain(&kq);
1311 KERNEL_LOCK(l->l_biglocks, l);
1312 } else {
1313 mutex_exit(proc_lock);
1314 }
1315
1316 pathbuf_stringcopy_put(data->ed_pathbuf, data->ed_pathstring);
1317 pathbuf_destroy(data->ed_pathbuf);
1318 PNBUF_PUT(data->ed_resolvedpathbuf);
1319#ifdef TRACE_EXEC
1320 DPRINTF(("%s finished\n", __func__));
1321#endif
1322 return EJUSTRETURN;
1323
1324 exec_abort:
1325 SDT_PROBE(proc, kernel, , exec__failure, error, 0, 0, 0, 0);
1326 rw_exit(&p->p_reflock);
1327 if (!no_local_exec_lock)
1328 rw_exit(&exec_lock);
1329
1330 pathbuf_stringcopy_put(data->ed_pathbuf, data->ed_pathstring);
1331 pathbuf_destroy(data->ed_pathbuf);
1332 PNBUF_PUT(data->ed_resolvedpathbuf);
1333
1334 /*
1335 * the old process doesn't exist anymore. exit gracefully.
1336 * get rid of the (new) address space we have created, if any, get rid
1337 * of our namei data and vnode, and exit noting failure
1338 */
1339 uvm_deallocate(&vm->vm_map, VM_MIN_ADDRESS,
1340 VM_MAXUSER_ADDRESS - VM_MIN_ADDRESS);
1341
1342 exec_free_emul_arg(epp);
1343 pool_put(&exec_pool, data->ed_argp);
1344 kmem_free(epp->ep_hdr, epp->ep_hdrlen);
1345 if (epp->ep_emul_root != NULL)
1346 vrele(epp->ep_emul_root);
1347 if (epp->ep_interp != NULL)
1348 vrele(epp->ep_interp);
1349
1350 /* Acquire the sched-state mutex (exit1() will release it). */
1351 if (!is_spawn) {
1352 mutex_enter(p->p_lock);
1353 exit1(l, error, SIGABRT);
1354 }
1355
1356 return error;
1357}
1358
1359int
1360execve1(struct lwp *l, const char *path, char * const *args,
1361 char * const *envs, execve_fetch_element_t fetch_element)
1362{
1363 struct execve_data data;
1364 int error;
1365
1366 error = execve_loadvm(l, path, args, envs, fetch_element, &data);
1367 if (error)
1368 return error;
1369 error = execve_runproc(l, &data, false, false);
1370 return error;
1371}
1372
1373static size_t
1374fromptrsz(const struct exec_package *epp)
1375{
1376 return (epp->ep_flags & EXEC_FROM32) ? sizeof(int) : sizeof(char *);
1377}
1378
1379static size_t
1380ptrsz(const struct exec_package *epp)
1381{
1382 return (epp->ep_flags & EXEC_32) ? sizeof(int) : sizeof(char *);
1383}
1384
1385static size_t
1386calcargs(struct execve_data * restrict data, const size_t argenvstrlen)
1387{
1388 struct exec_package * const epp = &data->ed_pack;
1389
1390 const size_t nargenvptrs =
1391 1 + /* long argc */
1392 data->ed_argc + /* char *argv[] */
1393 1 + /* \0 */
1394 data->ed_envc + /* char *env[] */
1395 1; /* \0 */
1396
1397 return (nargenvptrs * ptrsz(epp)) /* pointers */
1398 + argenvstrlen /* strings */
1399 + epp->ep_esch->es_arglen; /* auxinfo */
1400}
1401
1402static size_t
1403calcstack(struct execve_data * restrict data, const size_t gaplen)
1404{
1405 struct exec_package * const epp = &data->ed_pack;
1406
1407 data->ed_szsigcode = epp->ep_esch->es_emul->e_esigcode -
1408 epp->ep_esch->es_emul->e_sigcode;
1409
1410 data->ed_ps_strings_sz = (epp->ep_flags & EXEC_32) ?
1411 sizeof(struct ps_strings32) : sizeof(struct ps_strings);
1412
1413 const size_t sigcode_psstr_sz =
1414 data->ed_szsigcode + /* sigcode */
1415 data->ed_ps_strings_sz + /* ps_strings */
1416 STACK_PTHREADSPACE; /* pthread space */
1417
1418 const size_t stacklen =
1419 data->ed_argslen +
1420 gaplen +
1421 sigcode_psstr_sz;
1422
1423 /* make the stack "safely" aligned */
1424 return STACK_LEN_ALIGN(stacklen, STACK_ALIGNBYTES);
1425}
1426
1427static int
1428copyoutargs(struct execve_data * restrict data, struct lwp *l,
1429 char * const newstack)
1430{
1431 struct exec_package * const epp = &data->ed_pack;
1432 struct proc *p = l->l_proc;
1433 int error;
1434
1435 memset(&data->ed_arginfo, 0, sizeof(data->ed_arginfo));
1436
1437 /* remember information about the process */
1438 data->ed_arginfo.ps_nargvstr = data->ed_argc;
1439 data->ed_arginfo.ps_nenvstr = data->ed_envc;
1440
1441 /*
1442 * Allocate the stack address passed to the newly execve()'ed process.
1443 *
1444 * The new stack address will be set to the SP (stack pointer) register
1445 * in setregs().
1446 */
1447
1448 char *newargs = STACK_ALLOC(
1449 STACK_SHRINK(newstack, data->ed_argslen), data->ed_argslen);
1450
1451 error = (*epp->ep_esch->es_copyargs)(l, epp,
1452 &data->ed_arginfo, &newargs, data->ed_argp);
1453
1454 if (error) {
1455 DPRINTF(("%s: copyargs failed %d\n", __func__, error));
1456 return error;
1457 }
1458
1459 error = copyoutpsstrs(data, p);
1460 if (error != 0)
1461 return error;
1462
1463 return 0;
1464}
1465
1466static int
1467copyoutpsstrs(struct execve_data * restrict data, struct proc *p)
1468{
1469 struct exec_package * const epp = &data->ed_pack;
1470 struct ps_strings32 arginfo32;
1471 void *aip;
1472 int error;
1473
1474 /* fill process ps_strings info */
1475 p->p_psstrp = (vaddr_t)STACK_ALLOC(STACK_GROW(epp->ep_minsaddr,
1476 STACK_PTHREADSPACE), data->ed_ps_strings_sz);
1477
1478 if (epp->ep_flags & EXEC_32) {
1479 aip = &arginfo32;
1480 arginfo32.ps_argvstr = (vaddr_t)data->ed_arginfo.ps_argvstr;
1481 arginfo32.ps_nargvstr = data->ed_arginfo.ps_nargvstr;
1482 arginfo32.ps_envstr = (vaddr_t)data->ed_arginfo.ps_envstr;
1483 arginfo32.ps_nenvstr = data->ed_arginfo.ps_nenvstr;
1484 } else
1485 aip = &data->ed_arginfo;
1486
1487 /* copy out the process's ps_strings structure */
1488 if ((error = copyout(aip, (void *)p->p_psstrp, data->ed_ps_strings_sz))
1489 != 0) {
1490 DPRINTF(("%s: ps_strings copyout %p->%p size %zu failed\n",
1491 __func__, aip, (void *)p->p_psstrp, data->ed_ps_strings_sz));
1492 return error;
1493 }
1494
1495 return 0;
1496}
1497
1498static int
1499copyinargs(struct execve_data * restrict data, char * const *args,
1500 char * const *envs, execve_fetch_element_t fetch_element, char **dpp)
1501{
1502 struct exec_package * const epp = &data->ed_pack;
1503 char *dp;
1504 size_t i;
1505 int error;
1506
1507 dp = *dpp;
1508
1509 data->ed_argc = 0;
1510
1511 /* copy the fake args list, if there's one, freeing it as we go */
1512 if (epp->ep_flags & EXEC_HASARGL) {
1513 struct exec_fakearg *fa = epp->ep_fa;
1514
1515 while (fa->fa_arg != NULL) {
1516 const size_t maxlen = ARG_MAX - (dp - data->ed_argp);
1517 size_t len;
1518
1519 len = strlcpy(dp, fa->fa_arg, maxlen);
1520 /* Count NUL into len. */
1521 if (len < maxlen)
1522 len++;
1523 else {
1524 while (fa->fa_arg != NULL) {
1525 kmem_free(fa->fa_arg, fa->fa_len);
1526 fa++;
1527 }
1528 kmem_free(epp->ep_fa, epp->ep_fa_len);
1529 epp->ep_flags &= ~EXEC_HASARGL;
1530 return E2BIG;
1531 }
1532 ktrexecarg(fa->fa_arg, len - 1);
1533 dp += len;
1534
1535 kmem_free(fa->fa_arg, fa->fa_len);
1536 fa++;
1537 data->ed_argc++;
1538 }
1539 kmem_free(epp->ep_fa, epp->ep_fa_len);
1540 epp->ep_flags &= ~EXEC_HASARGL;
1541 }
1542
1543 /*
1544 * Read and count argument strings from user.
1545 */
1546
1547 if (args == NULL) {
1548 DPRINTF(("%s: null args\n", __func__));
1549 return EINVAL;
1550 }
1551 if (epp->ep_flags & EXEC_SKIPARG)
1552 args = (const void *)((const char *)args + fromptrsz(epp));
1553 i = 0;
1554 error = copyinargstrs(data, args, fetch_element, &dp, &i, ktr_execarg);
1555 if (error != 0) {
1556 DPRINTF(("%s: copyin arg %d\n", __func__, error));
1557 return error;
1558 }
1559 data->ed_argc += i;
1560
1561 /*
1562 * Read and count environment strings from user.
1563 */
1564
1565 data->ed_envc = 0;
1566 /* environment need not be there */
1567 if (envs == NULL)
1568 goto done;
1569 i = 0;
1570 error = copyinargstrs(data, envs, fetch_element, &dp, &i, ktr_execenv);
1571 if (error != 0) {
1572 DPRINTF(("%s: copyin env %d\n", __func__, error));
1573 return error;
1574 }
1575 data->ed_envc += i;
1576
1577done:
1578 *dpp = dp;
1579
1580 return 0;
1581}
1582
1583static int
1584copyinargstrs(struct execve_data * restrict data, char * const *strs,
1585 execve_fetch_element_t fetch_element, char **dpp, size_t *ip,
1586 void (*ktr)(const void *, size_t))
1587{
1588 char *dp, *sp;
1589 size_t i;
1590 int error;
1591
1592 dp = *dpp;
1593
1594 i = 0;
1595 while (1) {
1596 const size_t maxlen = ARG_MAX - (dp - data->ed_argp);
1597 size_t len;
1598
1599 if ((error = (*fetch_element)(strs, i, &sp)) != 0) {
1600 return error;
1601 }
1602 if (!sp)
1603 break;
1604 if ((error = copyinstr(sp, dp, maxlen, &len)) != 0) {
1605 if (error == ENAMETOOLONG)
1606 error = E2BIG;
1607 return error;
1608 }
1609 if (__predict_false(ktrace_on))
1610 (*ktr)(dp, len - 1);
1611 dp += len;
1612 i++;
1613 }
1614
1615 *dpp = dp;
1616 *ip = i;
1617
1618 return 0;
1619}
1620
1621/*
1622 * Copy argv and env strings from kernel buffer (argp) to the new stack.
1623 * Those strings are located just after auxinfo.
1624 */
1625int
1626copyargs(struct lwp *l, struct exec_package *pack, struct ps_strings *arginfo,
1627 char **stackp, void *argp)
1628{
1629 char **cpp, *dp, *sp;
1630 size_t len;
1631 void *nullp;
1632 long argc, envc;
1633 int error;
1634
1635 cpp = (char **)*stackp;
1636 nullp = NULL;
1637 argc = arginfo->ps_nargvstr;
1638 envc = arginfo->ps_nenvstr;
1639
1640 /* argc on stack is long */
1641 CTASSERT(sizeof(*cpp) == sizeof(argc));
1642
1643 dp = (char *)(cpp +
1644 1 + /* long argc */
1645 argc + /* char *argv[] */
1646 1 + /* \0 */
1647 envc + /* char *env[] */
1648 1) + /* \0 */
1649 pack->ep_esch->es_arglen; /* auxinfo */
1650 sp = argp;
1651
1652 if ((error = copyout(&argc, cpp++, sizeof(argc))) != 0) {
1653 COPYPRINTF("", cpp - 1, sizeof(argc));
1654 return error;
1655 }
1656
1657 /* XXX don't copy them out, remap them! */
1658 arginfo->ps_argvstr = cpp; /* remember location of argv for later */
1659
1660 for (; --argc >= 0; sp += len, dp += len) {
1661 if ((error = copyout(&dp, cpp++, sizeof(dp))) != 0) {
1662 COPYPRINTF("", cpp - 1, sizeof(dp));
1663 return error;
1664 }
1665 if ((error = copyoutstr(sp, dp, ARG_MAX, &len)) != 0) {
1666 COPYPRINTF("str", dp, (size_t)ARG_MAX);
1667 return error;
1668 }
1669 }
1670
1671 if ((error = copyout(&nullp, cpp++, sizeof(nullp))) != 0) {
1672 COPYPRINTF("", cpp - 1, sizeof(nullp));
1673 return error;
1674 }
1675
1676 arginfo->ps_envstr = cpp; /* remember location of envp for later */
1677
1678 for (; --envc >= 0; sp += len, dp += len) {
1679 if ((error = copyout(&dp, cpp++, sizeof(dp))) != 0) {
1680 COPYPRINTF("", cpp - 1, sizeof(dp));
1681 return error;
1682 }
1683 if ((error = copyoutstr(sp, dp, ARG_MAX, &len)) != 0) {
1684 COPYPRINTF("str", dp, (size_t)ARG_MAX);
1685 return error;
1686 }
1687
1688 }
1689
1690 if ((error = copyout(&nullp, cpp++, sizeof(nullp))) != 0) {
1691 COPYPRINTF("", cpp - 1, sizeof(nullp));
1692 return error;
1693 }
1694
1695 *stackp = (char *)cpp;
1696 return 0;
1697}
1698
1699
1700/*
1701 * Add execsw[] entries.
1702 */
1703int
1704exec_add(struct execsw *esp, int count)
1705{
1706 struct exec_entry *it;
1707 int i;
1708
1709 if (count == 0) {
1710 return 0;
1711 }
1712
1713 /* Check for duplicates. */
1714 rw_enter(&exec_lock, RW_WRITER);
1715 for (i = 0; i < count; i++) {
1716 LIST_FOREACH(it, &ex_head, ex_list) {
1717 /* assume unique (makecmds, probe_func, emulation) */
1718 if (it->ex_sw->es_makecmds == esp[i].es_makecmds &&
1719 it->ex_sw->u.elf_probe_func ==
1720 esp[i].u.elf_probe_func &&
1721 it->ex_sw->es_emul == esp[i].es_emul) {
1722 rw_exit(&exec_lock);
1723 return EEXIST;
1724 }
1725 }
1726 }
1727
1728 /* Allocate new entries. */
1729 for (i = 0; i < count; i++) {
1730 it = kmem_alloc(sizeof(*it), KM_SLEEP);
1731 it->ex_sw = &esp[i];
1732 LIST_INSERT_HEAD(&ex_head, it, ex_list);
1733 }
1734
1735 /* update execsw[] */
1736 exec_init(0);
1737 rw_exit(&exec_lock);
1738 return 0;
1739}
1740
1741/*
1742 * Remove execsw[] entry.
1743 */
1744int
1745exec_remove(struct execsw *esp, int count)
1746{
1747 struct exec_entry *it, *next;
1748 int i;
1749 const struct proclist_desc *pd;
1750 proc_t *p;
1751
1752 if (count == 0) {
1753 return 0;
1754 }
1755
1756 /* Abort if any are busy. */
1757 rw_enter(&exec_lock, RW_WRITER);
1758 for (i = 0; i < count; i++) {
1759 mutex_enter(proc_lock);
1760 for (pd = proclists; pd->pd_list != NULL; pd++) {
1761 PROCLIST_FOREACH(p, pd->pd_list) {
1762 if (p->p_execsw == &esp[i]) {
1763 mutex_exit(proc_lock);
1764 rw_exit(&exec_lock);
1765 return EBUSY;
1766 }
1767 }
1768 }
1769 mutex_exit(proc_lock);
1770 }
1771
1772 /* None are busy, so remove them all. */
1773 for (i = 0; i < count; i++) {
1774 for (it = LIST_FIRST(&ex_head); it != NULL; it = next) {
1775 next = LIST_NEXT(it, ex_list);
1776 if (it->ex_sw == &esp[i]) {
1777 LIST_REMOVE(it, ex_list);
1778 kmem_free(it, sizeof(*it));
1779 break;
1780 }
1781 }
1782 }
1783
1784 /* update execsw[] */
1785 exec_init(0);
1786 rw_exit(&exec_lock);
1787 return 0;
1788}
1789
1790/*
1791 * Initialize exec structures. If init_boot is true, also does necessary
1792 * one-time initialization (it's called from main() that way).
1793 * Once system is multiuser, this should be called with exec_lock held,
1794 * i.e. via exec_{add|remove}().
1795 */
1796int
1797exec_init(int init_boot)
1798{
1799 const struct execsw **sw;
1800 struct exec_entry *ex;
1801 SLIST_HEAD(,exec_entry) first;
1802 SLIST_HEAD(,exec_entry) any;
1803 SLIST_HEAD(,exec_entry) last;
1804 int i, sz;
1805
1806 if (init_boot) {
1807 /* do one-time initializations */
1808 vaddr_t vmin = 0, vmax;
1809
1810 rw_init(&exec_lock);
1811 mutex_init(&sigobject_lock, MUTEX_DEFAULT, IPL_NONE);
1812 exec_map = uvm_km_suballoc(kernel_map, &vmin, &vmax,
1813 maxexec*NCARGS, VM_MAP_PAGEABLE, false, NULL);
1814 pool_init(&exec_pool, NCARGS, 0, 0, PR_NOALIGN|PR_NOTOUCH,
1815 "execargs", &exec_palloc, IPL_NONE);
1816 pool_sethardlimit(&exec_pool, maxexec, "should not happen", 0);
1817 } else {
1818 KASSERT(rw_write_held(&exec_lock));
1819 }
1820
1821 /* Sort each entry onto the appropriate queue. */
1822 SLIST_INIT(&first);
1823 SLIST_INIT(&any);
1824 SLIST_INIT(&last);
1825 sz = 0;
1826 LIST_FOREACH(ex, &ex_head, ex_list) {
1827 switch(ex->ex_sw->es_prio) {
1828 case EXECSW_PRIO_FIRST:
1829 SLIST_INSERT_HEAD(&first, ex, ex_slist);
1830 break;
1831 case EXECSW_PRIO_ANY:
1832 SLIST_INSERT_HEAD(&any, ex, ex_slist);
1833 break;
1834 case EXECSW_PRIO_LAST:
1835 SLIST_INSERT_HEAD(&last, ex, ex_slist);
1836 break;
1837 default:
1838 panic("%s", __func__);
1839 break;
1840 }
1841 sz++;
1842 }
1843
1844 /*
1845 * Create new execsw[]. Ensure we do not try a zero-sized
1846 * allocation.
1847 */
1848 sw = kmem_alloc(sz * sizeof(struct execsw *) + 1, KM_SLEEP);
1849 i = 0;
1850 SLIST_FOREACH(ex, &first, ex_slist) {
1851 sw[i++] = ex->ex_sw;
1852 }
1853 SLIST_FOREACH(ex, &any, ex_slist) {
1854 sw[i++] = ex->ex_sw;
1855 }
1856 SLIST_FOREACH(ex, &last, ex_slist) {
1857 sw[i++] = ex->ex_sw;
1858 }
1859
1860 /* Replace old execsw[] and free used memory. */
1861 if (execsw != NULL) {
1862 kmem_free(__UNCONST(execsw),
1863 nexecs * sizeof(struct execsw *) + 1);
1864 }
1865 execsw = sw;
1866 nexecs = sz;
1867
1868 /* Figure out the maximum size of an exec header. */
1869 exec_maxhdrsz = sizeof(int);
1870 for (i = 0; i < nexecs; i++) {
1871 if (execsw[i]->es_hdrsz > exec_maxhdrsz)
1872 exec_maxhdrsz = execsw[i]->es_hdrsz;
1873 }
1874
1875 return 0;
1876}
1877
1878static int
1879exec_sigcode_map(struct proc *p, const struct emul *e)
1880{
1881 vaddr_t va;
1882 vsize_t sz;
1883 int error;
1884 struct uvm_object *uobj;
1885
1886 sz = (vaddr_t)e->e_esigcode - (vaddr_t)e->e_sigcode;
1887
1888 if (e->e_sigobject == NULL || sz == 0) {
1889 return 0;
1890 }
1891
1892 /*
1893 * If we don't have a sigobject for this emulation, create one.
1894 *
1895 * sigobject is an anonymous memory object (just like SYSV shared
1896 * memory) that we keep a permanent reference to and that we map
1897 * in all processes that need this sigcode. The creation is simple,
1898 * we create an object, add a permanent reference to it, map it in
1899 * kernel space, copy out the sigcode to it and unmap it.
1900 * We map it with PROT_READ|PROT_EXEC into the process just
1901 * the way sys_mmap() would map it.
1902 */
1903
1904 uobj = *e->e_sigobject;
1905 if (uobj == NULL) {
1906 mutex_enter(&sigobject_lock);
1907 if ((uobj = *e->e_sigobject) == NULL) {
1908 uobj = uao_create(sz, 0);
1909 (*uobj->pgops->pgo_reference)(uobj);
1910 va = vm_map_min(kernel_map);
1911 if ((error = uvm_map(kernel_map, &va, round_page(sz),
1912 uobj, 0, 0,
1913 UVM_MAPFLAG(UVM_PROT_RW, UVM_PROT_RW,
1914 UVM_INH_SHARE, UVM_ADV_RANDOM, 0)))) {
1915 printf("kernel mapping failed %d\n", error);
1916 (*uobj->pgops->pgo_detach)(uobj);
1917 mutex_exit(&sigobject_lock);
1918 return error;
1919 }
1920 memcpy((void *)va, e->e_sigcode, sz);
1921#ifdef PMAP_NEED_PROCWR
1922 pmap_procwr(&proc0, va, sz);
1923#endif
1924 uvm_unmap(kernel_map, va, va + round_page(sz));
1925 *e->e_sigobject = uobj;
1926 }
1927 mutex_exit(&sigobject_lock);
1928 }
1929
1930 /* Just a hint to uvm_map where to put it. */
1931 va = e->e_vm_default_addr(p, (vaddr_t)p->p_vmspace->vm_daddr,
1932 round_page(sz), p->p_vmspace->vm_map.flags & VM_MAP_TOPDOWN);
1933
1934#ifdef __alpha__
1935 /*
1936 * Tru64 puts /sbin/loader at the end of user virtual memory,
1937 * which causes the above calculation to put the sigcode at
1938 * an invalid address. Put it just below the text instead.
1939 */
1940 if (va == (vaddr_t)vm_map_max(&p->p_vmspace->vm_map)) {
1941 va = (vaddr_t)p->p_vmspace->vm_taddr - round_page(sz);
1942 }
1943#endif
1944
1945 (*uobj->pgops->pgo_reference)(uobj);
1946 error = uvm_map(&p->p_vmspace->vm_map, &va, round_page(sz),
1947 uobj, 0, 0,
1948 UVM_MAPFLAG(UVM_PROT_RX, UVM_PROT_RX, UVM_INH_SHARE,
1949 UVM_ADV_RANDOM, 0));
1950 if (error) {
1951 DPRINTF(("%s, %d: map %p "
1952 "uvm_map %#"PRIxVSIZE"@%#"PRIxVADDR" failed %d\n",
1953 __func__, __LINE__, &p->p_vmspace->vm_map, round_page(sz),
1954 va, error));
1955 (*uobj->pgops->pgo_detach)(uobj);
1956 return error;
1957 }
1958 p->p_sigctx.ps_sigcode = (void *)va;
1959 return 0;
1960}
1961
1962/*
1963 * Release a refcount on spawn_exec_data and destroy memory, if this
1964 * was the last one.
1965 */
1966static void
1967spawn_exec_data_release(struct spawn_exec_data *data)
1968{
1969 if (atomic_dec_32_nv(&data->sed_refcnt) != 0)
1970 return;
1971
1972 cv_destroy(&data->sed_cv_child_ready);
1973 mutex_destroy(&data->sed_mtx_child);
1974
1975 if (data->sed_actions)
1976 posix_spawn_fa_free(data->sed_actions,
1977 data->sed_actions->len);
1978 if (data->sed_attrs)
1979 kmem_free(data->sed_attrs,
1980 sizeof(*data->sed_attrs));
1981 kmem_free(data, sizeof(*data));
1982}
1983
1984/*
1985 * A child lwp of a posix_spawn operation starts here and ends up in
1986 * cpu_spawn_return, dealing with all filedescriptor and scheduler
1987 * manipulations in between.
1988 * The parent waits for the child, as it is not clear whether the child
1989 * will be able to acquire its own exec_lock. If it can, the parent can
1990 * be released early and continue running in parallel. If not (or if the
1991 * magic debug flag is passed in the scheduler attribute struct), the
1992 * child rides on the parent's exec lock until it is ready to return to
1993 * to userland - and only then releases the parent. This method loses
1994 * concurrency, but improves error reporting.
1995 */
1996static void
1997spawn_return(void *arg)
1998{
1999 struct spawn_exec_data *spawn_data = arg;
2000 struct lwp *l = curlwp;
2001 struct proc *p = l->l_proc;
2002 int error, newfd;
2003 int ostat;
2004 size_t i;
2005 const struct posix_spawn_file_actions_entry *fae;
2006 pid_t ppid;
2007 register_t retval;
2008 bool have_reflock;
2009 bool parent_is_waiting = true;
2010
2011 /*
2012 * Check if we can release parent early.
2013 * We either need to have no sed_attrs, or sed_attrs does not
2014 * have POSIX_SPAWN_RETURNERROR or one of the flags, that require
2015 * safe access to the parent proc (passed in sed_parent).
2016 * We then try to get the exec_lock, and only if that works, we can
2017 * release the parent here already.
2018 */
2019 ppid = spawn_data->sed_parent->p_pid;
2020 if ((!spawn_data->sed_attrs
2021 || (spawn_data->sed_attrs->sa_flags
2022 & (POSIX_SPAWN_RETURNERROR|POSIX_SPAWN_SETPGROUP)) == 0)
2023 && rw_tryenter(&exec_lock, RW_READER)) {
2024 parent_is_waiting = false;
2025 mutex_enter(&spawn_data->sed_mtx_child);
2026 cv_signal(&spawn_data->sed_cv_child_ready);
2027 mutex_exit(&spawn_data->sed_mtx_child);
2028 }
2029
2030 /* don't allow debugger access yet */
2031 rw_enter(&p->p_reflock, RW_WRITER);
2032 have_reflock = true;
2033
2034 error = 0;
2035 /* handle posix_spawn_file_actions */
2036 if (spawn_data->sed_actions != NULL) {
2037 for (i = 0; i < spawn_data->sed_actions->len; i++) {
2038 fae = &spawn_data->sed_actions->fae[i];
2039 switch (fae->fae_action) {
2040 case FAE_OPEN:
2041 if (fd_getfile(fae->fae_fildes) != NULL) {
2042 error = fd_close(fae->fae_fildes);
2043 if (error)
2044 break;
2045 }
2046 error = fd_open(fae->fae_path, fae->fae_oflag,
2047 fae->fae_mode, &newfd);
2048 if (error)
2049 break;
2050 if (newfd != fae->fae_fildes) {
2051 error = dodup(l, newfd,
2052 fae->fae_fildes, 0, &retval);
2053 if (fd_getfile(newfd) != NULL)
2054 fd_close(newfd);
2055 }
2056 break;
2057 case FAE_DUP2:
2058 error = dodup(l, fae->fae_fildes,
2059 fae->fae_newfildes, 0, &retval);
2060 break;
2061 case FAE_CLOSE:
2062 if (fd_getfile(fae->fae_fildes) == NULL) {
2063 error = EBADF;
2064 break;
2065 }
2066 error = fd_close(fae->fae_fildes);
2067 break;
2068 }
2069 if (error)
2070 goto report_error;
2071 }
2072 }
2073
2074 /* handle posix_spawnattr */
2075 if (spawn_data->sed_attrs != NULL) {
2076 struct sigaction sigact;
2077 memset(&sigact, 0, sizeof(sigact));
2078 sigact._sa_u._sa_handler = SIG_DFL;
2079 sigact.sa_flags = 0;
2080
2081 /*
2082 * set state to SSTOP so that this proc can be found by pid.
2083 * see proc_enterprp, do_sched_setparam below
2084 */
2085 mutex_enter(proc_lock);
2086 /*
2087 * p_stat should be SACTIVE, so we need to adjust the
2088 * parent's p_nstopchild here. For safety, just make
2089 * we're on the good side of SDEAD before we adjust.
2090 */
2091 ostat = p->p_stat;
2092 KASSERT(ostat < SSTOP);
2093 p->p_stat = SSTOP;
2094 p->p_waited = 0;
2095 p->p_pptr->p_nstopchild++;
2096 mutex_exit(proc_lock);
2097
2098 /* Set process group */
2099 if (spawn_data->sed_attrs->sa_flags & POSIX_SPAWN_SETPGROUP) {
2100 pid_t mypid = p->p_pid,
2101 pgrp = spawn_data->sed_attrs->sa_pgroup;
2102
2103 if (pgrp == 0)
2104 pgrp = mypid;
2105
2106 error = proc_enterpgrp(spawn_data->sed_parent,
2107 mypid, pgrp, false);
2108 if (error)
2109 goto report_error_stopped;
2110 }
2111
2112 /* Set scheduler policy */
2113 if (spawn_data->sed_attrs->sa_flags & POSIX_SPAWN_SETSCHEDULER)
2114 error = do_sched_setparam(p->p_pid, 0,
2115 spawn_data->sed_attrs->sa_schedpolicy,
2116 &spawn_data->sed_attrs->sa_schedparam);
2117 else if (spawn_data->sed_attrs->sa_flags
2118 & POSIX_SPAWN_SETSCHEDPARAM) {
2119 error = do_sched_setparam(ppid, 0,
2120 SCHED_NONE, &spawn_data->sed_attrs->sa_schedparam);
2121 }
2122 if (error)
2123 goto report_error_stopped;
2124
2125 /* Reset user ID's */
2126 if (spawn_data->sed_attrs->sa_flags & POSIX_SPAWN_RESETIDS) {
2127 error = do_setresuid(l, -1,
2128 kauth_cred_getgid(l->l_cred), -1,
2129 ID_E_EQ_R | ID_E_EQ_S);
2130 if (error)
2131 goto report_error_stopped;
2132 error = do_setresuid(l, -1,
2133 kauth_cred_getuid(l->l_cred), -1,
2134 ID_E_EQ_R | ID_E_EQ_S);
2135 if (error)
2136 goto report_error_stopped;
2137 }
2138
2139 /* Set signal masks/defaults */
2140 if (spawn_data->sed_attrs->sa_flags & POSIX_SPAWN_SETSIGMASK) {
2141 mutex_enter(p->p_lock);
2142 error = sigprocmask1(l, SIG_SETMASK,
2143 &spawn_data->sed_attrs->sa_sigmask, NULL);
2144 mutex_exit(p->p_lock);
2145 if (error)
2146 goto report_error_stopped;
2147 }
2148
2149 if (spawn_data->sed_attrs->sa_flags & POSIX_SPAWN_SETSIGDEF) {
2150 /*
2151 * The following sigaction call is using a sigaction
2152 * version 0 trampoline which is in the compatibility
2153 * code only. This is not a problem because for SIG_DFL
2154 * and SIG_IGN, the trampolines are now ignored. If they
2155 * were not, this would be a problem because we are
2156 * holding the exec_lock, and the compat code needs
2157 * to do the same in order to replace the trampoline
2158 * code of the process.
2159 */
2160 for (i = 1; i <= NSIG; i++) {
2161 if (sigismember(
2162 &spawn_data->sed_attrs->sa_sigdefault, i))
2163 sigaction1(l, i, &sigact, NULL, NULL,
2164 0);
2165 }
2166 }
2167 mutex_enter(proc_lock);
2168 p->p_stat = ostat;
2169 p->p_pptr->p_nstopchild--;
2170 mutex_exit(proc_lock);
2171 }
2172
2173 /* now do the real exec */
2174 error = execve_runproc(l, &spawn_data->sed_exec, parent_is_waiting,
2175 true);
2176 have_reflock = false;
2177 if (error == EJUSTRETURN)
2178 error = 0;
2179 else if (error)
2180 goto report_error;
2181
2182 if (parent_is_waiting) {
2183 mutex_enter(&spawn_data->sed_mtx_child);
2184 cv_signal(&spawn_data->sed_cv_child_ready);
2185 mutex_exit(&spawn_data->sed_mtx_child);
2186 }
2187
2188 /* release our refcount on the data */
2189 spawn_exec_data_release(spawn_data);
2190
2191 if (p->p_slflag & PSL_TRACED) {
2192 /* Paranoid check */
2193 mutex_enter(proc_lock);
2194 if (!(p->p_slflag & PSL_TRACED)) {
2195 mutex_exit(proc_lock);
2196 goto cpu_return;
2197 }
2198
2199 mutex_enter(p->p_lock);
2200 eventswitch(TRAP_CHLD);
2201 }
2202
2203 cpu_return:
2204 /* and finally: leave to userland for the first time */
2205 cpu_spawn_return(l);
2206
2207 /* NOTREACHED */
2208 return;
2209
2210 report_error_stopped:
2211 mutex_enter(proc_lock);
2212 p->p_stat = ostat;
2213 p->p_pptr->p_nstopchild--;
2214 mutex_exit(proc_lock);
2215 report_error:
2216 if (have_reflock) {
2217 /*
2218 * We have not passed through execve_runproc(),
2219 * which would have released the p_reflock and also
2220 * taken ownership of the sed_exec part of spawn_data,
2221 * so release/free both here.
2222 */
2223 rw_exit(&p->p_reflock);
2224 execve_free_data(&spawn_data->sed_exec);
2225 }
2226
2227 if (parent_is_waiting) {
2228 /* pass error to parent */
2229 mutex_enter(&spawn_data->sed_mtx_child);
2230 spawn_data->sed_error = error;
2231 cv_signal(&spawn_data->sed_cv_child_ready);
2232 mutex_exit(&spawn_data->sed_mtx_child);
2233 } else {
2234 rw_exit(&exec_lock);
2235 }
2236
2237 /* release our refcount on the data */
2238 spawn_exec_data_release(spawn_data);
2239
2240 /* done, exit */
2241 mutex_enter(p->p_lock);
2242 /*
2243 * Posix explicitly asks for an exit code of 127 if we report
2244 * errors from the child process - so, unfortunately, there
2245 * is no way to report a more exact error code.
2246 * A NetBSD specific workaround is POSIX_SPAWN_RETURNERROR as
2247 * flag bit in the attrp argument to posix_spawn(2), see above.
2248 */
2249 exit1(l, 127, 0);
2250}
2251
2252void
2253posix_spawn_fa_free(struct posix_spawn_file_actions *fa, size_t len)
2254{
2255
2256 for (size_t i = 0; i < len; i++) {
2257 struct posix_spawn_file_actions_entry *fae = &fa->fae[i];
2258 if (fae->fae_action != FAE_OPEN)
2259 continue;
2260 kmem_strfree(fae->fae_path);
2261 }
2262 if (fa->len > 0)
2263 kmem_free(fa->fae, sizeof(*fa->fae) * fa->len);
2264 kmem_free(fa, sizeof(*fa));
2265}
2266
2267static int
2268posix_spawn_fa_alloc(struct posix_spawn_file_actions **fap,
2269 const struct posix_spawn_file_actions *ufa, rlim_t lim)
2270{
2271 struct posix_spawn_file_actions *fa;
2272 struct posix_spawn_file_actions_entry *fae;
2273 char *pbuf = NULL;
2274 int error;
2275 size_t i = 0;
2276
2277 fa = kmem_alloc(sizeof(*fa), KM_SLEEP);
2278 error = copyin(ufa, fa, sizeof(*fa));
2279 if (error || fa->len == 0) {
2280 kmem_free(fa, sizeof(*fa));
2281 return error; /* 0 if not an error, and len == 0 */
2282 }
2283
2284 if (fa->len > lim) {
2285 kmem_free(fa, sizeof(*fa));
2286 return EINVAL;
2287 }
2288
2289 fa->size = fa->len;
2290 size_t fal = fa->len * sizeof(*fae);
2291 fae = fa->fae;
2292 fa->fae = kmem_alloc(fal, KM_SLEEP);
2293 error = copyin(fae, fa->fae, fal);
2294 if (error)
2295 goto out;
2296
2297 pbuf = PNBUF_GET();
2298 for (; i < fa->len; i++) {
2299 fae = &fa->fae[i];
2300 if (fae->fae_action != FAE_OPEN)
2301 continue;
2302 error = copyinstr(fae->fae_path, pbuf, MAXPATHLEN, &fal);
2303 if (error)
2304 goto out;
2305 fae->fae_path = kmem_alloc(fal, KM_SLEEP);
2306 memcpy(fae->fae_path, pbuf, fal);
2307 }
2308 PNBUF_PUT(pbuf);
2309
2310 *fap = fa;
2311 return 0;
2312out:
2313 if (pbuf)
2314 PNBUF_PUT(pbuf);
2315 posix_spawn_fa_free(fa, i);
2316 return error;
2317}
2318
2319int
2320check_posix_spawn(struct lwp *l1)
2321{
2322 int error, tnprocs, count;
2323 uid_t uid;
2324 struct proc *p1;
2325
2326 p1 = l1->l_proc;
2327 uid = kauth_cred_getuid(l1->l_cred);
2328 tnprocs = atomic_inc_uint_nv(&nprocs);
2329
2330 /*
2331 * Although process entries are dynamically created, we still keep
2332 * a global limit on the maximum number we will create.
2333 */
2334 if (__predict_false(tnprocs >= maxproc))
2335 error = -1;
2336 else
2337 error = kauth_authorize_process(l1->l_cred,
2338 KAUTH_PROCESS_FORK, p1, KAUTH_ARG(tnprocs), NULL, NULL);
2339
2340 if (error) {
2341 atomic_dec_uint(&nprocs);
2342 return EAGAIN;
2343 }
2344
2345 /*
2346 * Enforce limits.
2347 */
2348 count = chgproccnt(uid, 1);
2349 if (kauth_authorize_process(l1->l_cred, KAUTH_PROCESS_RLIMIT,
2350 p1, KAUTH_ARG(KAUTH_REQ_PROCESS_RLIMIT_BYPASS),
2351 &p1->p_rlimit[RLIMIT_NPROC], KAUTH_ARG(RLIMIT_NPROC)) != 0 &&
2352 __predict_false(count > p1->p_rlimit[RLIMIT_NPROC].rlim_cur)) {
2353 (void)chgproccnt(uid, -1);
2354 atomic_dec_uint(&nprocs);
2355 return EAGAIN;
2356 }
2357
2358 return 0;
2359}
2360
2361int
2362do_posix_spawn(struct lwp *l1, pid_t *pid_res, bool *child_ok, const char *path,
2363 struct posix_spawn_file_actions *fa,
2364 struct posix_spawnattr *sa,
2365 char *const *argv, char *const *envp,
2366 execve_fetch_element_t fetch)
2367{
2368
2369 struct proc *p1, *p2;
2370 struct lwp *l2;
2371 int error;
2372 struct spawn_exec_data *spawn_data;
2373 vaddr_t uaddr;
2374 pid_t pid;
2375 bool have_exec_lock = false;
2376
2377 p1 = l1->l_proc;
2378
2379 /* Allocate and init spawn_data */
2380 spawn_data = kmem_zalloc(sizeof(*spawn_data), KM_SLEEP);
2381 spawn_data->sed_refcnt = 1; /* only parent so far */
2382 cv_init(&spawn_data->sed_cv_child_ready, "pspawn");
2383 mutex_init(&spawn_data->sed_mtx_child, MUTEX_DEFAULT, IPL_NONE);
2384 mutex_enter(&spawn_data->sed_mtx_child);
2385
2386 /*
2387 * Do the first part of the exec now, collect state
2388 * in spawn_data.
2389 */
2390 error = execve_loadvm(l1, path, argv,
2391 envp, fetch, &spawn_data->sed_exec);
2392 if (error == EJUSTRETURN)
2393 error = 0;
2394 else if (error)
2395 goto error_exit;
2396
2397 have_exec_lock = true;
2398
2399 /*
2400 * Allocate virtual address space for the U-area now, while it
2401 * is still easy to abort the fork operation if we're out of
2402 * kernel virtual address space.
2403 */
2404 uaddr = uvm_uarea_alloc();
2405 if (__predict_false(uaddr == 0)) {
2406 error = ENOMEM;
2407 goto error_exit;
2408 }
2409
2410 /*
2411 * Allocate new proc. Borrow proc0 vmspace for it, we will
2412 * replace it with its own before returning to userland
2413 * in the child.
2414 * This is a point of no return, we will have to go through
2415 * the child proc to properly clean it up past this point.
2416 */
2417 p2 = proc_alloc();
2418 pid = p2->p_pid;
2419
2420 /*
2421 * Make a proc table entry for the new process.
2422 * Start by zeroing the section of proc that is zero-initialized,
2423 * then copy the section that is copied directly from the parent.
2424 */
2425 memset(&p2->p_startzero, 0,
2426 (unsigned) ((char *)&p2->p_endzero - (char *)&p2->p_startzero));
2427 memcpy(&p2->p_startcopy, &p1->p_startcopy,
2428 (unsigned) ((char *)&p2->p_endcopy - (char *)&p2->p_startcopy));
2429 p2->p_vmspace = proc0.p_vmspace;
2430
2431 TAILQ_INIT(&p2->p_sigpend.sp_info);
2432
2433 LIST_INIT(&p2->p_lwps);
2434 LIST_INIT(&p2->p_sigwaiters);
2435
2436 /*
2437 * Duplicate sub-structures as needed.
2438 * Increase reference counts on shared objects.
2439 * Inherit flags we want to keep. The flags related to SIGCHLD
2440 * handling are important in order to keep a consistent behaviour
2441 * for the child after the fork. If we are a 32-bit process, the
2442 * child will be too.
2443 */
2444 p2->p_flag =
2445 p1->p_flag & (PK_SUGID | PK_NOCLDWAIT | PK_CLDSIGIGN | PK_32);
2446 p2->p_emul = p1->p_emul;
2447 p2->p_execsw = p1->p_execsw;
2448
2449 mutex_init(&p2->p_stmutex, MUTEX_DEFAULT, IPL_HIGH);
2450 mutex_init(&p2->p_auxlock, MUTEX_DEFAULT, IPL_NONE);
2451 rw_init(&p2->p_reflock);
2452 cv_init(&p2->p_waitcv, "wait");
2453 cv_init(&p2->p_lwpcv, "lwpwait");
2454
2455 p2->p_lock = mutex_obj_alloc(MUTEX_DEFAULT, IPL_NONE);
2456
2457 kauth_proc_fork(p1, p2);
2458
2459 p2->p_raslist = NULL;
2460 p2->p_fd = fd_copy();
2461
2462 /* XXX racy */
2463 p2->p_mqueue_cnt = p1->p_mqueue_cnt;
2464
2465 p2->p_cwdi = cwdinit();
2466
2467 /*
2468 * Note: p_limit (rlimit stuff) is copy-on-write, so normally
2469 * we just need increase pl_refcnt.
2470 */
2471 if (!p1->p_limit->pl_writeable) {
2472 lim_addref(p1->p_limit);
2473 p2->p_limit = p1->p_limit;
2474 } else {
2475 p2->p_limit = lim_copy(p1->p_limit);
2476 }
2477
2478 p2->p_lflag = 0;
2479 l1->l_vforkwaiting = false;
2480 p2->p_sflag = 0;
2481 p2->p_slflag = 0;
2482 p2->p_pptr = p1;
2483 p2->p_ppid = p1->p_pid;
2484 LIST_INIT(&p2->p_children);
2485
2486 p2->p_aio = NULL;
2487
2488#ifdef KTRACE
2489 /*
2490 * Copy traceflag and tracefile if enabled.
2491 * If not inherited, these were zeroed above.
2492 */
2493 if (p1->p_traceflag & KTRFAC_INHERIT) {
2494 mutex_enter(&ktrace_lock);
2495 p2->p_traceflag = p1->p_traceflag;
2496 if ((p2->p_tracep = p1->p_tracep) != NULL)
2497 ktradref(p2);
2498 mutex_exit(&ktrace_lock);
2499 }
2500#endif
2501
2502 /*
2503 * Create signal actions for the child process.
2504 */
2505 p2->p_sigacts = sigactsinit(p1, 0);
2506 mutex_enter(p1->p_lock);
2507 p2->p_sflag |=
2508 (p1->p_sflag & (PS_STOPFORK | PS_STOPEXEC | PS_NOCLDSTOP));
2509 sched_proc_fork(p1, p2);
2510 mutex_exit(p1->p_lock);
2511
2512 p2->p_stflag = p1->p_stflag;
2513
2514 /*
2515 * p_stats.
2516 * Copy parts of p_stats, and zero out the rest.
2517 */
2518 p2->p_stats = pstatscopy(p1->p_stats);
2519
2520 /* copy over machdep flags to the new proc */
2521 cpu_proc_fork(p1, p2);
2522
2523 /*
2524 * Prepare remaining parts of spawn data
2525 */
2526 spawn_data->sed_actions = fa;
2527 spawn_data->sed_attrs = sa;
2528
2529 spawn_data->sed_parent = p1;
2530
2531 /* create LWP */
2532 lwp_create(l1, p2, uaddr, 0, NULL, 0, spawn_return, spawn_data,
2533 &l2, l1->l_class, &l1->l_sigmask, &l1->l_sigstk);
2534 l2->l_ctxlink = NULL; /* reset ucontext link */
2535
2536 /*
2537 * Copy the credential so other references don't see our changes.
2538 * Test to see if this is necessary first, since in the common case
2539 * we won't need a private reference.
2540 */
2541 if (kauth_cred_geteuid(l2->l_cred) != kauth_cred_getsvuid(l2->l_cred) ||
2542 kauth_cred_getegid(l2->l_cred) != kauth_cred_getsvgid(l2->l_cred)) {
2543 l2->l_cred = kauth_cred_copy(l2->l_cred);
2544 kauth_cred_setsvuid(l2->l_cred, kauth_cred_geteuid(l2->l_cred));
2545 kauth_cred_setsvgid(l2->l_cred, kauth_cred_getegid(l2->l_cred));
2546 }
2547
2548 /* Update the master credentials. */
2549 if (l2->l_cred != p2->p_cred) {
2550 kauth_cred_t ocred;
2551
2552 kauth_cred_hold(l2->l_cred);
2553 mutex_enter(p2->p_lock);
2554 ocred = p2->p_cred;
2555 p2->p_cred = l2->l_cred;
2556 mutex_exit(p2->p_lock);
2557 kauth_cred_free(ocred);
2558 }
2559
2560 *child_ok = true;
2561 spawn_data->sed_refcnt = 2; /* child gets it as well */
2562#if 0
2563 l2->l_nopreempt = 1; /* start it non-preemptable */
2564#endif
2565
2566 /*
2567 * It's now safe for the scheduler and other processes to see the
2568 * child process.
2569 */
2570 mutex_enter(proc_lock);
2571
2572 if (p1->p_session->s_ttyvp != NULL && p1->p_lflag & PL_CONTROLT)
2573 p2->p_lflag |= PL_CONTROLT;
2574
2575 LIST_INSERT_HEAD(&p1->p_children, p2, p_sibling);
2576 p2->p_exitsig = SIGCHLD; /* signal for parent on exit */
2577
2578 if ((p1->p_slflag & (PSL_TRACEPOSIX_SPAWN|PSL_TRACED)) ==
2579 (PSL_TRACEPOSIX_SPAWN|PSL_TRACED)) {
2580 proc_changeparent(p2, p1->p_pptr);
2581 p1->p_pspid = p2->p_pid;
2582 p2->p_pspid = p1->p_pid;
2583 }
2584
2585 LIST_INSERT_AFTER(p1, p2, p_pglist);
2586 LIST_INSERT_HEAD(&allproc, p2, p_list);
2587
2588 p2->p_trace_enabled = trace_is_enabled(p2);
2589#ifdef __HAVE_SYSCALL_INTERN
2590 (*p2->p_emul->e_syscall_intern)(p2);
2591#endif
2592
2593 /*
2594 * Make child runnable, set start time, and add to run queue except
2595 * if the parent requested the child to start in SSTOP state.
2596 */
2597 mutex_enter(p2->p_lock);
2598
2599 getmicrotime(&p2->p_stats->p_start);
2600
2601 lwp_lock(l2);
2602 KASSERT(p2->p_nrlwps == 1);
2603 p2->p_nrlwps = 1;
2604 p2->p_stat = SACTIVE;
2605 l2->l_stat = LSRUN;
2606 sched_enqueue(l2, false);
2607 lwp_unlock(l2);
2608
2609 mutex_exit(p2->p_lock);
2610 mutex_exit(proc_lock);
2611
2612 cv_wait(&spawn_data->sed_cv_child_ready, &spawn_data->sed_mtx_child);
2613 error = spawn_data->sed_error;
2614 mutex_exit(&spawn_data->sed_mtx_child);
2615 spawn_exec_data_release(spawn_data);
2616
2617 rw_exit(&p1->p_reflock);
2618 rw_exit(&exec_lock);
2619 have_exec_lock = false;
2620
2621 *pid_res = pid;
2622
2623 if (error)
2624 return error;
2625
2626 if (p1->p_slflag & PSL_TRACED) {
2627 /* Paranoid check */
2628 mutex_enter(proc_lock);
2629 if ((p1->p_slflag & (PSL_TRACEPOSIX_SPAWN|PSL_TRACED)) !=
2630 (PSL_TRACEPOSIX_SPAWN|PSL_TRACED)) {
2631 mutex_exit(proc_lock);
2632 return 0;
2633 }
2634
2635 mutex_enter(p1->p_lock);
2636 eventswitch(TRAP_CHLD);
2637 }
2638 return 0;
2639
2640 error_exit:
2641 if (have_exec_lock) {
2642 execve_free_data(&spawn_data->sed_exec);
2643 rw_exit(&p1->p_reflock);
2644 rw_exit(&exec_lock);
2645 }
2646 mutex_exit(&spawn_data->sed_mtx_child);
2647 spawn_exec_data_release(spawn_data);
2648
2649 return error;
2650}
2651
2652int
2653sys_posix_spawn(struct lwp *l1, const struct sys_posix_spawn_args *uap,
2654 register_t *retval)
2655{
2656 /* {
2657 syscallarg(pid_t *) pid;
2658 syscallarg(const char *) path;
2659 syscallarg(const struct posix_spawn_file_actions *) file_actions;
2660 syscallarg(const struct posix_spawnattr *) attrp;
2661 syscallarg(char *const *) argv;
2662 syscallarg(char *const *) envp;
2663 } */
2664
2665 int error;
2666 struct posix_spawn_file_actions *fa = NULL;
2667 struct posix_spawnattr *sa = NULL;
2668 pid_t pid;
2669 bool child_ok = false;
2670 rlim_t max_fileactions;
2671 proc_t *p = l1->l_proc;
2672
2673 error = check_posix_spawn(l1);
2674 if (error) {
2675 *retval = error;
2676 return 0;
2677 }
2678
2679 /* copy in file_actions struct */
2680 if (SCARG(uap, file_actions) != NULL) {
2681 max_fileactions = 2 * uimin(p->p_rlimit[RLIMIT_NOFILE].rlim_cur,
2682 maxfiles);
2683 error = posix_spawn_fa_alloc(&fa, SCARG(uap, file_actions),
2684 max_fileactions);
2685 if (error)
2686 goto error_exit;
2687 }
2688
2689 /* copyin posix_spawnattr struct */
2690 if (SCARG(uap, attrp) != NULL) {
2691 sa = kmem_alloc(sizeof(*sa), KM_SLEEP);
2692 error = copyin(SCARG(uap, attrp), sa, sizeof(*sa));
2693 if (error)
2694 goto error_exit;
2695 }
2696
2697 /*
2698 * Do the spawn
2699 */
2700 error = do_posix_spawn(l1, &pid, &child_ok, SCARG(uap, path), fa, sa,
2701 SCARG(uap, argv), SCARG(uap, envp), execve_fetch_element);
2702 if (error)
2703 goto error_exit;
2704
2705 if (error == 0 && SCARG(uap, pid) != NULL)
2706 error = copyout(&pid, SCARG(uap, pid), sizeof(pid));
2707
2708 *retval = error;
2709 return 0;
2710
2711 error_exit:
2712 if (!child_ok) {
2713 (void)chgproccnt(kauth_cred_getuid(l1->l_cred), -1);
2714 atomic_dec_uint(&nprocs);
2715
2716 if (sa)
2717 kmem_free(sa, sizeof(*sa));
2718 if (fa)
2719 posix_spawn_fa_free(fa, fa->len);
2720 }
2721
2722 *retval = error;
2723 return 0;
2724}
2725
2726void
2727exec_free_emul_arg(struct exec_package *epp)
2728{
2729 if (epp->ep_emul_arg_free != NULL) {
2730 KASSERT(epp->ep_emul_arg != NULL);
2731 (*epp->ep_emul_arg_free)(epp->ep_emul_arg);
2732 epp->ep_emul_arg_free = NULL;
2733 epp->ep_emul_arg = NULL;
2734 } else {
2735 KASSERT(epp->ep_emul_arg == NULL);
2736 }
2737}
2738
2739#ifdef DEBUG_EXEC
2740static void
2741dump_vmcmds(const struct exec_package * const epp, size_t x, int error)
2742{
2743 struct exec_vmcmd *vp = &epp->ep_vmcmds.evs_cmds[0];
2744 size_t j;
2745
2746 if (error == 0)
2747 DPRINTF(("vmcmds %u\n", epp->ep_vmcmds.evs_used));
2748 else
2749 DPRINTF(("vmcmds %zu/%u, error %d\n", x,
2750 epp->ep_vmcmds.evs_used, error));
2751
2752 for (j = 0; j < epp->ep_vmcmds.evs_used; j++) {
2753 DPRINTF(("vmcmd[%zu] = vmcmd_map_%s %#"
2754 PRIxVADDR"/%#"PRIxVSIZE" fd@%#"
2755 PRIxVSIZE" prot=0%o flags=%d\n", j,
2756 vp[j].ev_proc == vmcmd_map_pagedvn ?
2757 "pagedvn" :
2758 vp[j].ev_proc == vmcmd_map_readvn ?
2759 "readvn" :
2760 vp[j].ev_proc == vmcmd_map_zero ?
2761 "zero" : "*unknown*",
2762 vp[j].ev_addr, vp[j].ev_len,
2763 vp[j].ev_offset, vp[j].ev_prot,
2764 vp[j].ev_flags));
2765 if (error != 0 && j == x)
2766 DPRINTF((" ^--- failed\n"));
2767 }
2768}
2769#endif
2770