2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
4 * Copyright (c) 1993, David Greenman
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
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.
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
32 #include "opt_capsicum.h"
33 #include "opt_hwpmc_hooks.h"
34 #include "opt_ktrace.h"
37 #include <sys/param.h>
38 #include <sys/systm.h>
41 #include <sys/capsicum.h>
42 #include <sys/compressor.h>
43 #include <sys/eventhandler.h>
45 #include <sys/fcntl.h>
46 #include <sys/filedesc.h>
47 #include <sys/imgact.h>
48 #include <sys/imgact_elf.h>
49 #include <sys/kernel.h>
51 #include <sys/malloc.h>
53 #include <sys/mount.h>
54 #include <sys/mutex.h>
55 #include <sys/namei.h>
58 #include <sys/ptrace.h>
60 #include <sys/resourcevar.h>
61 #include <sys/rwlock.h>
62 #include <sys/sched.h>
64 #include <sys/sf_buf.h>
66 #include <sys/signalvar.h>
69 #include <sys/syscallsubr.h>
70 #include <sys/sysctl.h>
71 #include <sys/sysent.h>
72 #include <sys/sysproto.h>
73 #include <sys/timers.h>
74 #include <sys/umtxvar.h>
75 #include <sys/vnode.h>
78 #include <sys/ktrace.h>
82 #include <vm/vm_param.h>
84 #include <vm/vm_page.h>
85 #include <vm/vm_map.h>
86 #include <vm/vm_kern.h>
87 #include <vm/vm_extern.h>
88 #include <vm/vm_object.h>
89 #include <vm/vm_pager.h>
92 #include <sys/pmckern.h>
95 #include <security/audit/audit.h>
96 #include <security/mac/mac_framework.h>
99 #include <sys/dtrace_bsd.h>
100 dtrace_execexit_func_t dtrace_fasttrap_exec;
103 SDT_PROVIDER_DECLARE(proc);
104 SDT_PROBE_DEFINE1(proc, , , exec, "char *");
105 SDT_PROBE_DEFINE1(proc, , , exec__failure, "int");
106 SDT_PROBE_DEFINE1(proc, , , exec__success, "char *");
108 MALLOC_DEFINE(M_PARGS, "proc-args", "Process arguments");
110 int coredump_pack_fileinfo = 1;
111 SYSCTL_INT(_kern, OID_AUTO, coredump_pack_fileinfo, CTLFLAG_RWTUN,
112 &coredump_pack_fileinfo, 0,
113 "Enable file path packing in 'procstat -f' coredump notes");
115 int coredump_pack_vmmapinfo = 1;
116 SYSCTL_INT(_kern, OID_AUTO, coredump_pack_vmmapinfo, CTLFLAG_RWTUN,
117 &coredump_pack_vmmapinfo, 0,
118 "Enable file path packing in 'procstat -v' coredump notes");
120 static int sysctl_kern_ps_strings(SYSCTL_HANDLER_ARGS);
121 static int sysctl_kern_usrstack(SYSCTL_HANDLER_ARGS);
122 static int sysctl_kern_stackprot(SYSCTL_HANDLER_ARGS);
123 static int do_execve(struct thread *td, struct image_args *args,
124 struct mac *mac_p, struct vmspace *oldvmspace);
126 /* XXX This should be vm_size_t. */
127 SYSCTL_PROC(_kern, KERN_PS_STRINGS, ps_strings, CTLTYPE_ULONG|CTLFLAG_RD|
128 CTLFLAG_CAPRD|CTLFLAG_MPSAFE, NULL, 0, sysctl_kern_ps_strings, "LU",
129 "Location of process' ps_strings structure");
131 /* XXX This should be vm_size_t. */
132 SYSCTL_PROC(_kern, KERN_USRSTACK, usrstack, CTLTYPE_ULONG|CTLFLAG_RD|
133 CTLFLAG_CAPRD|CTLFLAG_MPSAFE, NULL, 0, sysctl_kern_usrstack, "LU",
134 "Top of process stack");
136 SYSCTL_PROC(_kern, OID_AUTO, stackprot, CTLTYPE_INT|CTLFLAG_RD|CTLFLAG_MPSAFE,
137 NULL, 0, sysctl_kern_stackprot, "I",
138 "Stack memory permissions");
140 u_long ps_arg_cache_limit = PAGE_SIZE / 16;
141 SYSCTL_ULONG(_kern, OID_AUTO, ps_arg_cache_limit, CTLFLAG_RW,
142 &ps_arg_cache_limit, 0,
143 "Process' command line characters cache limit");
145 static int disallow_high_osrel;
146 SYSCTL_INT(_kern, OID_AUTO, disallow_high_osrel, CTLFLAG_RW,
147 &disallow_high_osrel, 0,
148 "Disallow execution of binaries built for higher version of the world");
150 static int map_at_zero = 0;
151 SYSCTL_INT(_security_bsd, OID_AUTO, map_at_zero, CTLFLAG_RWTUN, &map_at_zero, 0,
152 "Permit processes to map an object at virtual address 0.");
155 sysctl_kern_ps_strings(SYSCTL_HANDLER_ARGS)
162 if (req->flags & SCTL_MASK32) {
164 val = (unsigned int)p->p_sysent->sv_psstrings;
165 error = SYSCTL_OUT(req, &val, sizeof(val));
168 error = SYSCTL_OUT(req, &p->p_sysent->sv_psstrings,
169 sizeof(p->p_sysent->sv_psstrings));
174 sysctl_kern_usrstack(SYSCTL_HANDLER_ARGS)
181 if (req->flags & SCTL_MASK32) {
183 val = (unsigned int)p->p_sysent->sv_usrstack;
184 error = SYSCTL_OUT(req, &val, sizeof(val));
187 error = SYSCTL_OUT(req, &p->p_sysent->sv_usrstack,
188 sizeof(p->p_sysent->sv_usrstack));
193 sysctl_kern_stackprot(SYSCTL_HANDLER_ARGS)
198 return (SYSCTL_OUT(req, &p->p_sysent->sv_stackprot,
199 sizeof(p->p_sysent->sv_stackprot)));
203 * Each of the items is a pointer to a `const struct execsw', hence the
204 * double pointer here.
206 static const struct execsw **execsw;
208 #ifndef _SYS_SYSPROTO_H_
217 sys_execve(struct thread *td, struct execve_args *uap)
219 struct image_args args;
220 struct vmspace *oldvmspace;
223 error = pre_execve(td, &oldvmspace);
226 error = exec_copyin_args(&args, uap->fname, UIO_USERSPACE,
227 uap->argv, uap->envv);
229 error = kern_execve(td, &args, NULL, oldvmspace);
230 post_execve(td, error, oldvmspace);
231 AUDIT_SYSCALL_EXIT(error == EJUSTRETURN ? 0 : error, td);
235 #ifndef _SYS_SYSPROTO_H_
236 struct fexecve_args {
243 sys_fexecve(struct thread *td, struct fexecve_args *uap)
245 struct image_args args;
246 struct vmspace *oldvmspace;
249 error = pre_execve(td, &oldvmspace);
252 error = exec_copyin_args(&args, NULL, UIO_SYSSPACE,
253 uap->argv, uap->envv);
256 error = kern_execve(td, &args, NULL, oldvmspace);
258 post_execve(td, error, oldvmspace);
259 AUDIT_SYSCALL_EXIT(error == EJUSTRETURN ? 0 : error, td);
263 #ifndef _SYS_SYSPROTO_H_
264 struct __mac_execve_args {
273 sys___mac_execve(struct thread *td, struct __mac_execve_args *uap)
276 struct image_args args;
277 struct vmspace *oldvmspace;
280 error = pre_execve(td, &oldvmspace);
283 error = exec_copyin_args(&args, uap->fname, UIO_USERSPACE,
284 uap->argv, uap->envv);
286 error = kern_execve(td, &args, uap->mac_p, oldvmspace);
287 post_execve(td, error, oldvmspace);
288 AUDIT_SYSCALL_EXIT(error == EJUSTRETURN ? 0 : error, td);
296 pre_execve(struct thread *td, struct vmspace **oldvmspace)
301 KASSERT(td == curthread, ("non-current thread %p", td));
304 if ((p->p_flag & P_HADTHREADS) != 0) {
306 if (thread_single(p, SINGLE_BOUNDARY) != 0)
310 KASSERT(error != 0 || (td->td_pflags & TDP_EXECVMSPC) == 0,
312 *oldvmspace = p->p_vmspace;
317 post_execve(struct thread *td, int error, struct vmspace *oldvmspace)
321 KASSERT(td == curthread, ("non-current thread %p", td));
323 if ((p->p_flag & P_HADTHREADS) != 0) {
326 * If success, we upgrade to SINGLE_EXIT state to
327 * force other threads to suicide.
329 if (error == EJUSTRETURN)
330 thread_single(p, SINGLE_EXIT);
332 thread_single_end(p, SINGLE_BOUNDARY);
335 exec_cleanup(td, oldvmspace);
339 * kern_execve() has the astonishing property of not always returning to
340 * the caller. If sufficiently bad things happen during the call to
341 * do_execve(), it can end up calling exit1(); as a result, callers must
342 * avoid doing anything which they might need to undo (e.g., allocating
346 kern_execve(struct thread *td, struct image_args *args, struct mac *mac_p,
347 struct vmspace *oldvmspace)
350 AUDIT_ARG_ARGV(args->begin_argv, args->argc,
351 exec_args_get_begin_envv(args) - args->begin_argv);
352 AUDIT_ARG_ENVV(exec_args_get_begin_envv(args), args->envc,
353 args->endp - exec_args_get_begin_envv(args));
354 return (do_execve(td, args, mac_p, oldvmspace));
358 execve_nosetid(struct image_params *imgp)
360 imgp->credential_setid = false;
361 if (imgp->newcred != NULL) {
362 crfree(imgp->newcred);
363 imgp->newcred = NULL;
368 * In-kernel implementation of execve(). All arguments are assumed to be
369 * userspace pointers from the passed thread.
372 do_execve(struct thread *td, struct image_args *args, struct mac *mac_p,
373 struct vmspace *oldvmspace)
375 struct proc *p = td->td_proc;
377 struct ucred *oldcred;
378 struct uidinfo *euip = NULL;
379 uintptr_t stack_base;
380 struct image_params image_params, *imgp;
382 int (*img_first)(struct image_params *);
383 struct pargs *oldargs = NULL, *newargs = NULL;
384 struct sigacts *oldsigacts = NULL, *newsigacts = NULL;
386 struct ktr_io_params *kiop;
388 struct vnode *oldtextvp = NULL, *newtextvp;
389 int credential_changing;
391 struct label *interpvplabel = NULL;
395 struct pmckern_procexec pe;
397 int error, i, orig_osrel;
399 Elf_Brandinfo *orig_brandinfo;
400 static const char fexecv_proc_title[] = "(fexecv)";
402 imgp = &image_params;
408 * Lock the process and set the P_INEXEC flag to indicate that
409 * it should be left alone until we're done here. This is
410 * necessary to avoid race conditions - e.g. in ptrace() -
411 * that might allow a local user to illicitly obtain elevated
415 KASSERT((p->p_flag & P_INEXEC) == 0,
416 ("%s(): process already has P_INEXEC flag", __func__));
417 p->p_flag |= P_INEXEC;
421 * Initialize part of the common data
423 bzero(imgp, sizeof(*imgp));
427 oldcred = p->p_ucred;
428 orig_osrel = p->p_osrel;
429 orig_fctl0 = p->p_fctl0;
430 orig_brandinfo = p->p_elf_brandinfo;
433 error = mac_execve_enter(imgp, mac_p);
439 * Translate the file name. namei() returns a vnode pointer
440 * in ni_vp among other things.
442 * XXXAUDIT: It would be desirable to also audit the name of the
443 * interpreter if this is an interpreted binary.
445 if (args->fname != NULL) {
446 NDINIT(&nd, LOOKUP, ISOPEN | LOCKLEAF | LOCKSHARED | FOLLOW |
447 SAVENAME | AUDITVNODE1, UIO_SYSSPACE, args->fname, td);
450 SDT_PROBE1(proc, , , exec, args->fname);
453 if (args->fname != NULL) {
454 #ifdef CAPABILITY_MODE
456 * While capability mode can't reach this point via direct
457 * path arguments to execve(), we also don't allow
458 * interpreters to be used in capability mode (for now).
459 * Catch indirect lookups and return a permissions error.
461 if (IN_CAPABILITY_MODE(td)) {
470 newtextvp = nd.ni_vp;
471 imgp->vp = newtextvp;
473 AUDIT_ARG_FD(args->fd);
475 * Descriptors opened only with O_EXEC or O_RDONLY are allowed.
477 error = fgetvp_exec(td, args->fd, &cap_fexecve_rights, &newtextvp);
480 vn_lock(newtextvp, LK_SHARED | LK_RETRY);
481 AUDIT_ARG_VNODE1(newtextvp);
482 imgp->vp = newtextvp;
486 * Check file permissions. Also 'opens' file and sets its vnode to
489 error = exec_check_permissions(imgp);
491 goto exec_fail_dealloc;
493 imgp->object = imgp->vp->v_object;
494 if (imgp->object != NULL)
495 vm_object_reference(imgp->object);
497 error = exec_map_first_page(imgp);
499 goto exec_fail_dealloc;
501 imgp->proc->p_osrel = 0;
502 imgp->proc->p_fctl0 = 0;
503 imgp->proc->p_elf_brandinfo = NULL;
506 * Implement image setuid/setgid.
508 * Determine new credentials before attempting image activators
509 * so that it can be used by process_exec handlers to determine
510 * credential/setid changes.
512 * Don't honor setuid/setgid if the filesystem prohibits it or if
513 * the process is being traced.
515 * We disable setuid/setgid/etc in capability mode on the basis
516 * that most setugid applications are not written with that
517 * environment in mind, and will therefore almost certainly operate
518 * incorrectly. In principle there's no reason that setugid
519 * applications might not be useful in capability mode, so we may want
520 * to reconsider this conservative design choice in the future.
522 * XXXMAC: For the time being, use NOSUID to also prohibit
523 * transitions on the file system.
525 credential_changing = 0;
526 credential_changing |= (attr.va_mode & S_ISUID) &&
527 oldcred->cr_uid != attr.va_uid;
528 credential_changing |= (attr.va_mode & S_ISGID) &&
529 oldcred->cr_gid != attr.va_gid;
531 will_transition = mac_vnode_execve_will_transition(oldcred, imgp->vp,
532 interpvplabel, imgp);
533 credential_changing |= will_transition;
536 /* Don't inherit PROC_PDEATHSIG_CTL value if setuid/setgid. */
537 if (credential_changing)
538 imgp->proc->p_pdeathsig = 0;
540 if (credential_changing &&
541 #ifdef CAPABILITY_MODE
542 ((oldcred->cr_flags & CRED_FLAG_CAPMODE) == 0) &&
544 (imgp->vp->v_mount->mnt_flag & MNT_NOSUID) == 0 &&
545 (p->p_flag & P_TRACED) == 0) {
546 imgp->credential_setid = true;
547 VOP_UNLOCK(imgp->vp);
548 imgp->newcred = crdup(oldcred);
549 if (attr.va_mode & S_ISUID) {
550 euip = uifind(attr.va_uid);
551 change_euid(imgp->newcred, euip);
553 vn_lock(imgp->vp, LK_SHARED | LK_RETRY);
554 if (attr.va_mode & S_ISGID)
555 change_egid(imgp->newcred, attr.va_gid);
557 * Implement correct POSIX saved-id behavior.
559 * XXXMAC: Note that the current logic will save the
560 * uid and gid if a MAC domain transition occurs, even
561 * though maybe it shouldn't.
563 change_svuid(imgp->newcred, imgp->newcred->cr_uid);
564 change_svgid(imgp->newcred, imgp->newcred->cr_gid);
567 * Implement correct POSIX saved-id behavior.
569 * XXX: It's not clear that the existing behavior is
570 * POSIX-compliant. A number of sources indicate that the
571 * saved uid/gid should only be updated if the new ruid is
572 * not equal to the old ruid, or the new euid is not equal
573 * to the old euid and the new euid is not equal to the old
574 * ruid. The FreeBSD code always updates the saved uid/gid.
575 * Also, this code uses the new (replaced) euid and egid as
576 * the source, which may or may not be the right ones to use.
578 if (oldcred->cr_svuid != oldcred->cr_uid ||
579 oldcred->cr_svgid != oldcred->cr_gid) {
580 VOP_UNLOCK(imgp->vp);
581 imgp->newcred = crdup(oldcred);
582 vn_lock(imgp->vp, LK_SHARED | LK_RETRY);
583 change_svuid(imgp->newcred, imgp->newcred->cr_uid);
584 change_svgid(imgp->newcred, imgp->newcred->cr_gid);
587 /* The new credentials are installed into the process later. */
590 * Do the best to calculate the full path to the image file.
592 if (args->fname != NULL && args->fname[0] == '/')
593 imgp->execpath = args->fname;
595 VOP_UNLOCK(imgp->vp);
596 if (vn_fullpath(imgp->vp, &imgp->execpath, &imgp->freepath) != 0)
597 imgp->execpath = args->fname;
598 vn_lock(imgp->vp, LK_SHARED | LK_RETRY);
602 * If the current process has a special image activator it
603 * wants to try first, call it. For example, emulating shell
604 * scripts differently.
607 if ((img_first = imgp->proc->p_sysent->sv_imgact_try) != NULL)
608 error = img_first(imgp);
611 * Loop through the list of image activators, calling each one.
612 * An activator returns -1 if there is no match, 0 on success,
613 * and an error otherwise.
615 for (i = 0; error == -1 && execsw[i]; ++i) {
616 if (execsw[i]->ex_imgact == NULL ||
617 execsw[i]->ex_imgact == img_first) {
620 error = (*execsw[i]->ex_imgact)(imgp);
626 goto exec_fail_dealloc;
630 * Special interpreter operation, cleanup and loop up to try to
631 * activate the interpreter.
633 if (imgp->interpreted) {
634 exec_unmap_first_page(imgp);
636 * The text reference needs to be removed for scripts.
637 * There is a short period before we determine that
638 * something is a script where text reference is active.
639 * The vnode lock is held over this entire period
640 * so nothing should illegitimately be blocked.
642 MPASS(imgp->textset);
643 VOP_UNSET_TEXT_CHECKED(newtextvp);
644 imgp->textset = false;
645 /* free name buffer and old vnode */
646 if (args->fname != NULL)
647 NDFREE(&nd, NDF_ONLY_PNBUF);
649 mac_execve_interpreter_enter(newtextvp, &interpvplabel);
652 VOP_CLOSE(newtextvp, FREAD, td->td_ucred, td);
656 vm_object_deallocate(imgp->object);
658 execve_nosetid(imgp);
659 imgp->execpath = NULL;
660 free(imgp->freepath, M_TEMP);
661 imgp->freepath = NULL;
662 /* set new name to that of the interpreter */
663 NDINIT(&nd, LOOKUP, ISOPEN | LOCKLEAF | LOCKSHARED | FOLLOW |
664 SAVENAME, UIO_SYSSPACE, imgp->interpreter_name, td);
665 args->fname = imgp->interpreter_name;
670 * NB: We unlock the vnode here because it is believed that none
671 * of the sv_copyout_strings/sv_fixup operations require the vnode.
673 VOP_UNLOCK(imgp->vp);
675 if (disallow_high_osrel &&
676 P_OSREL_MAJOR(p->p_osrel) > P_OSREL_MAJOR(__FreeBSD_version)) {
678 uprintf("Osrel %d for image %s too high\n", p->p_osrel,
679 imgp->execpath != NULL ? imgp->execpath : "<unresolved>");
680 vn_lock(imgp->vp, LK_SHARED | LK_RETRY);
681 goto exec_fail_dealloc;
684 /* ABI enforces the use of Capsicum. Switch into capabilities mode. */
685 if (SV_PROC_FLAG(p, SV_CAPSICUM))
686 sys_cap_enter(td, NULL);
689 * Copy out strings (args and env) and initialize stack base.
691 error = (*p->p_sysent->sv_copyout_strings)(imgp, &stack_base);
693 vn_lock(imgp->vp, LK_SHARED | LK_RETRY);
694 goto exec_fail_dealloc;
700 error = (*p->p_sysent->sv_fixup)(&stack_base, imgp);
702 vn_lock(imgp->vp, LK_SHARED | LK_RETRY);
703 goto exec_fail_dealloc;
706 if (args->fdp != NULL) {
707 /* Install a brand new file descriptor table. */
708 fdinstall_remapped(td, args->fdp);
712 * Keep on using the existing file descriptor table. For
713 * security and other reasons, the file descriptor table
714 * cannot be shared after an exec.
718 /* close files on exec */
723 * Malloc things before we need locks.
725 i = exec_args_get_begin_envv(imgp->args) - imgp->args->begin_argv;
726 /* Cache arguments if they fit inside our allowance */
727 if (ps_arg_cache_limit >= i + sizeof(struct pargs)) {
728 newargs = pargs_alloc(i);
729 bcopy(imgp->args->begin_argv, newargs->ar_args, i);
733 * For security and other reasons, signal handlers cannot
734 * be shared after an exec. The new process gets a copy of the old
735 * handlers. In execsigs(), the new process will have its signals
738 if (sigacts_shared(p->p_sigacts)) {
739 oldsigacts = p->p_sigacts;
740 newsigacts = sigacts_alloc();
741 sigacts_copy(newsigacts, oldsigacts);
744 vn_lock(imgp->vp, LK_SHARED | LK_RETRY);
748 p->p_sigacts = newsigacts;
752 /* reset caught signals */
755 /* name this process - nameiexec(p, ndp) */
756 bzero(p->p_comm, sizeof(p->p_comm));
758 bcopy(nd.ni_cnd.cn_nameptr, p->p_comm,
759 min(nd.ni_cnd.cn_namelen, MAXCOMLEN));
760 else if (vn_commname(newtextvp, p->p_comm, sizeof(p->p_comm)) != 0)
761 bcopy(fexecv_proc_title, p->p_comm, sizeof(fexecv_proc_title));
762 bcopy(p->p_comm, td->td_name, sizeof(td->td_name));
764 sched_clear_tdname(td);
768 * mark as execed, wakeup the process that vforked (if any) and tell
769 * it that it now has its own resources back
772 if ((p->p_flag2 & P2_NOTRACE_EXEC) == 0)
773 p->p_flag2 &= ~P2_NOTRACE;
774 if ((p->p_flag2 & P2_STKGAP_DISABLE_EXEC) == 0)
775 p->p_flag2 &= ~P2_STKGAP_DISABLE;
776 if (p->p_flag & P_PPWAIT) {
777 p->p_flag &= ~(P_PPWAIT | P_PPTRACE);
778 cv_broadcast(&p->p_pwait);
779 /* STOPs are no longer ignored, arrange for AST */
783 if ((imgp->sysent->sv_setid_allowed != NULL &&
784 !(*imgp->sysent->sv_setid_allowed)(td, imgp)) ||
785 (p->p_flag2 & P2_NO_NEW_PRIVS) != 0)
786 execve_nosetid(imgp);
789 * Implement image setuid/setgid installation.
791 if (imgp->credential_setid) {
793 * Turn off syscall tracing for set-id programs, except for
794 * root. Record any set-id flags first to make sure that
795 * we do not regain any tracing during a possible block.
799 kiop = ktrprocexec(p);
802 * Close any file descriptors 0..2 that reference procfs,
803 * then make sure file descriptors 0..2 are in use.
805 * Both fdsetugidsafety() and fdcheckstd() may call functions
806 * taking sleepable locks, so temporarily drop our locks.
809 VOP_UNLOCK(imgp->vp);
811 error = fdcheckstd(td);
812 vn_lock(imgp->vp, LK_SHARED | LK_RETRY);
814 goto exec_fail_dealloc;
817 if (will_transition) {
818 mac_vnode_execve_transition(oldcred, imgp->newcred,
819 imgp->vp, interpvplabel, imgp);
823 if (oldcred->cr_uid == oldcred->cr_ruid &&
824 oldcred->cr_gid == oldcred->cr_rgid)
825 p->p_flag &= ~P_SUGID;
828 * Set the new credentials.
830 if (imgp->newcred != NULL) {
831 proc_set_cred(p, imgp->newcred);
837 * Store the vp for use in procfs. This vnode was referenced by namei
840 oldtextvp = p->p_textvp;
841 p->p_textvp = newtextvp;
845 * Tell the DTrace fasttrap provider about the exec if it
846 * has declared an interest.
848 if (dtrace_fasttrap_exec)
849 dtrace_fasttrap_exec(p);
853 * Notify others that we exec'd, and clear the P_INEXEC flag
854 * as we're now a bona fide freshly-execed process.
856 KNOTE_LOCKED(p->p_klist, NOTE_EXEC);
857 p->p_flag &= ~P_INEXEC;
859 /* clear "fork but no exec" flag, as we _are_ execing */
860 p->p_acflag &= ~AFORK;
863 * Free any previous argument cache and replace it with
864 * the new argument cache, if any.
874 * Check if system-wide sampling is in effect or if the
875 * current process is using PMCs. If so, do exec() time
876 * processing. This processing needs to happen AFTER the
877 * P_INEXEC flag is cleared.
879 if (PMC_SYSTEM_SAMPLING_ACTIVE() || PMC_PROC_IS_USING_PMCS(p)) {
880 VOP_UNLOCK(imgp->vp);
881 pe.pm_credentialschanged = credential_changing;
882 pe.pm_entryaddr = imgp->entry_addr;
884 PMC_CALL_HOOK_X(td, PMC_FN_PROCESS_EXEC, (void *) &pe);
885 vn_lock(imgp->vp, LK_SHARED | LK_RETRY);
889 /* Set values passed into the program in registers. */
890 (*p->p_sysent->sv_setregs)(td, imgp, stack_base);
892 VOP_MMAPPED(imgp->vp);
894 SDT_PROBE1(proc, , , exec__success, args->fname);
898 p->p_osrel = orig_osrel;
899 p->p_fctl0 = orig_fctl0;
900 p->p_elf_brandinfo = orig_brandinfo;
903 if (imgp->firstpage != NULL)
904 exec_unmap_first_page(imgp);
906 if (imgp->vp != NULL) {
908 NDFREE(&nd, NDF_ONLY_PNBUF);
910 VOP_CLOSE(imgp->vp, FREAD, td->td_ucred, td);
912 VOP_UNSET_TEXT_CHECKED(imgp->vp);
916 VOP_UNLOCK(imgp->vp);
919 if (imgp->object != NULL)
920 vm_object_deallocate(imgp->object);
922 free(imgp->freepath, M_TEMP);
925 if (p->p_ptevents & PTRACE_EXEC) {
927 if (p->p_ptevents & PTRACE_EXEC)
928 td->td_dbgflags |= TDB_EXEC;
933 /* we're done here, clear P_INEXEC */
935 p->p_flag &= ~P_INEXEC;
938 SDT_PROBE1(proc, , , exec__failure, error);
941 if (imgp->newcred != NULL && oldcred != NULL)
942 crfree(imgp->newcred);
945 mac_execve_exit(imgp);
946 mac_execve_interpreter_exit(interpvplabel);
948 exec_free_args(args);
951 * Handle deferred decrement of ref counts.
953 if (oldtextvp != NULL)
956 ktr_io_params_free(kiop);
960 if (oldsigacts != NULL)
961 sigacts_free(oldsigacts);
965 if (error && imgp->vmspace_destroyed) {
966 /* sorry, no more process anymore. exit gracefully */
967 exec_cleanup(td, oldvmspace);
968 exit1(td, 0, SIGABRT);
978 * We don't want cpu_set_syscall_retval() to overwrite any of
979 * the register values put in place by exec_setregs().
980 * Implementations of cpu_set_syscall_retval() will leave
981 * registers unmodified when returning EJUSTRETURN.
983 return (error == 0 ? EJUSTRETURN : error);
987 exec_cleanup(struct thread *td, struct vmspace *oldvmspace)
989 if ((td->td_pflags & TDP_EXECVMSPC) != 0) {
990 KASSERT(td->td_proc->p_vmspace != oldvmspace,
991 ("oldvmspace still used"));
992 vmspace_free(oldvmspace);
993 td->td_pflags &= ~TDP_EXECVMSPC;
998 exec_map_first_page(struct image_params *imgp)
1004 if (imgp->firstpage != NULL)
1005 exec_unmap_first_page(imgp);
1007 object = imgp->vp->v_object;
1010 #if VM_NRESERVLEVEL > 0
1011 if ((object->flags & OBJ_COLORED) == 0) {
1012 VM_OBJECT_WLOCK(object);
1013 vm_object_color(object, 0);
1014 VM_OBJECT_WUNLOCK(object);
1017 error = vm_page_grab_valid_unlocked(&m, object, 0,
1018 VM_ALLOC_COUNT(VM_INITIAL_PAGEIN) |
1019 VM_ALLOC_NORMAL | VM_ALLOC_NOBUSY | VM_ALLOC_WIRED);
1021 if (error != VM_PAGER_OK)
1023 imgp->firstpage = sf_buf_alloc(m, 0);
1024 imgp->image_header = (char *)sf_buf_kva(imgp->firstpage);
1030 exec_unmap_first_page(struct image_params *imgp)
1034 if (imgp->firstpage != NULL) {
1035 m = sf_buf_page(imgp->firstpage);
1036 sf_buf_free(imgp->firstpage);
1037 imgp->firstpage = NULL;
1038 vm_page_unwire(m, PQ_ACTIVE);
1043 exec_onexec_old(struct thread *td)
1045 sigfastblock_clear(td);
1046 umtx_exec(td->td_proc);
1050 * Destroy old address space, and allocate a new stack.
1051 * The new stack is only sgrowsiz large because it is grown
1052 * automatically on a page fault.
1055 exec_new_vmspace(struct image_params *imgp, struct sysentvec *sv)
1058 struct proc *p = imgp->proc;
1059 struct vmspace *vmspace = p->p_vmspace;
1060 struct thread *td = curthread;
1062 struct rlimit rlim_stack;
1063 vm_offset_t sv_minuser, stack_addr;
1065 vm_prot_t stack_prot;
1068 imgp->vmspace_destroyed = 1;
1071 if (p->p_sysent->sv_onexec_old != NULL)
1072 p->p_sysent->sv_onexec_old(td);
1075 EVENTHANDLER_DIRECT_INVOKE(process_exec, p, imgp);
1078 * Blow away entire process VM, if address space not shared,
1079 * otherwise, create a new VM space so that other threads are
1082 map = &vmspace->vm_map;
1084 sv_minuser = sv->sv_minuser;
1086 sv_minuser = MAX(sv->sv_minuser, PAGE_SIZE);
1087 if (refcount_load(&vmspace->vm_refcnt) == 1 &&
1088 vm_map_min(map) == sv_minuser &&
1089 vm_map_max(map) == sv->sv_maxuser &&
1090 cpu_exec_vmspace_reuse(p, map)) {
1092 pmap_remove_pages(vmspace_pmap(vmspace));
1093 vm_map_remove(map, vm_map_min(map), vm_map_max(map));
1095 * An exec terminates mlockall(MCL_FUTURE).
1096 * ASLR and W^X states must be re-evaluated.
1099 vm_map_modflags(map, 0, MAP_WIREFUTURE | MAP_ASLR |
1100 MAP_ASLR_IGNSTART | MAP_WXORX);
1103 error = vmspace_exec(p, sv_minuser, sv->sv_maxuser);
1106 vmspace = p->p_vmspace;
1107 map = &vmspace->vm_map;
1109 map->flags |= imgp->map_flags;
1111 /* Map a shared page */
1112 obj = sv->sv_shared_page_obj;
1114 vm_object_reference(obj);
1115 error = vm_map_fixed(map, obj, 0,
1116 sv->sv_shared_page_base, sv->sv_shared_page_len,
1117 VM_PROT_READ | VM_PROT_EXECUTE,
1118 VM_PROT_READ | VM_PROT_EXECUTE,
1119 MAP_INHERIT_SHARE | MAP_ACC_NO_CHARGE);
1120 if (error != KERN_SUCCESS) {
1121 vm_object_deallocate(obj);
1122 return (vm_mmap_to_errno(error));
1126 /* Allocate a new stack */
1127 if (imgp->stack_sz != 0) {
1128 ssiz = trunc_page(imgp->stack_sz);
1130 lim_rlimit_proc(p, RLIMIT_STACK, &rlim_stack);
1132 if (ssiz > rlim_stack.rlim_max)
1133 ssiz = rlim_stack.rlim_max;
1134 if (ssiz > rlim_stack.rlim_cur) {
1135 rlim_stack.rlim_cur = ssiz;
1136 kern_setrlimit(curthread, RLIMIT_STACK, &rlim_stack);
1138 } else if (sv->sv_maxssiz != NULL) {
1139 ssiz = *sv->sv_maxssiz;
1143 imgp->eff_stack_sz = lim_cur(curthread, RLIMIT_STACK);
1144 if (ssiz < imgp->eff_stack_sz)
1145 imgp->eff_stack_sz = ssiz;
1146 stack_addr = sv->sv_usrstack - ssiz;
1147 stack_prot = obj != NULL && imgp->stack_prot != 0 ?
1148 imgp->stack_prot : sv->sv_stackprot;
1149 error = vm_map_stack(map, stack_addr, (vm_size_t)ssiz, stack_prot,
1150 VM_PROT_ALL, MAP_STACK_GROWS_DOWN);
1151 if (error != KERN_SUCCESS) {
1152 uprintf("exec_new_vmspace: mapping stack size %#jx prot %#x "
1153 "failed mach error %d errno %d\n", (uintmax_t)ssiz,
1154 stack_prot, error, vm_mmap_to_errno(error));
1155 return (vm_mmap_to_errno(error));
1159 * vm_ssize and vm_maxsaddr are somewhat antiquated concepts, but they
1160 * are still used to enforce the stack rlimit on the process stack.
1162 vmspace->vm_ssize = sgrowsiz >> PAGE_SHIFT;
1163 vmspace->vm_maxsaddr = (char *)stack_addr;
1165 return (sv->sv_onexec != NULL ? sv->sv_onexec(p, imgp) : 0);
1169 * Copy out argument and environment strings from the old process address
1170 * space into the temporary string buffer.
1173 exec_copyin_args(struct image_args *args, const char *fname,
1174 enum uio_seg segflg, char **argv, char **envv)
1179 bzero(args, sizeof(*args));
1184 * Allocate demand-paged memory for the file name, argument, and
1185 * environment strings.
1187 error = exec_alloc_args(args);
1192 * Copy the file name.
1194 error = exec_args_add_fname(args, fname, segflg);
1199 * extract arguments first
1202 error = fueword(argv++, &arg);
1209 error = exec_args_add_arg(args, (char *)(uintptr_t)arg,
1216 * extract environment strings
1220 error = fueword(envv++, &env);
1227 error = exec_args_add_env(args,
1228 (char *)(uintptr_t)env, UIO_USERSPACE);
1237 exec_free_args(args);
1242 exec_copyin_data_fds(struct thread *td, struct image_args *args,
1243 const void *data, size_t datalen, const int *fds, size_t fdslen)
1245 struct filedesc *ofdp;
1250 memset(args, '\0', sizeof(*args));
1251 ofdp = td->td_proc->p_fd;
1252 if (datalen >= ARG_MAX || fdslen >= ofdp->fd_nfiles)
1254 error = exec_alloc_args(args);
1258 args->begin_argv = args->buf;
1259 args->stringspace = ARG_MAX;
1263 * Argument buffer has been provided. Copy it into the
1264 * kernel as a single string and add a terminating null
1267 error = copyin(data, args->begin_argv, datalen);
1270 args->begin_argv[datalen] = '\0';
1271 args->endp = args->begin_argv + datalen + 1;
1272 args->stringspace -= datalen + 1;
1275 * Traditional argument counting. Count the number of
1278 for (p = args->begin_argv; p < args->endp; ++p)
1282 /* No argument buffer provided. */
1283 args->endp = args->begin_argv;
1286 /* Create new file descriptor table. */
1287 kfds = malloc(fdslen * sizeof(int), M_TEMP, M_WAITOK);
1288 error = copyin(fds, kfds, fdslen * sizeof(int));
1293 error = fdcopy_remapped(ofdp, kfds, fdslen, &args->fdp);
1300 exec_free_args(args);
1304 struct exec_args_kva {
1307 SLIST_ENTRY(exec_args_kva) next;
1310 DPCPU_DEFINE_STATIC(struct exec_args_kva *, exec_args_kva);
1312 static SLIST_HEAD(, exec_args_kva) exec_args_kva_freelist;
1313 static struct mtx exec_args_kva_mtx;
1314 static u_int exec_args_gen;
1317 exec_prealloc_args_kva(void *arg __unused)
1319 struct exec_args_kva *argkva;
1322 SLIST_INIT(&exec_args_kva_freelist);
1323 mtx_init(&exec_args_kva_mtx, "exec args kva", NULL, MTX_DEF);
1324 for (i = 0; i < exec_map_entries; i++) {
1325 argkva = malloc(sizeof(*argkva), M_PARGS, M_WAITOK);
1326 argkva->addr = kmap_alloc_wait(exec_map, exec_map_entry_size);
1327 argkva->gen = exec_args_gen;
1328 SLIST_INSERT_HEAD(&exec_args_kva_freelist, argkva, next);
1331 SYSINIT(exec_args_kva, SI_SUB_EXEC, SI_ORDER_ANY, exec_prealloc_args_kva, NULL);
1334 exec_alloc_args_kva(void **cookie)
1336 struct exec_args_kva *argkva;
1338 argkva = (void *)atomic_readandclear_ptr(
1339 (uintptr_t *)DPCPU_PTR(exec_args_kva));
1340 if (argkva == NULL) {
1341 mtx_lock(&exec_args_kva_mtx);
1342 while ((argkva = SLIST_FIRST(&exec_args_kva_freelist)) == NULL)
1343 (void)mtx_sleep(&exec_args_kva_freelist,
1344 &exec_args_kva_mtx, 0, "execkva", 0);
1345 SLIST_REMOVE_HEAD(&exec_args_kva_freelist, next);
1346 mtx_unlock(&exec_args_kva_mtx);
1348 kasan_mark((void *)argkva->addr, exec_map_entry_size,
1349 exec_map_entry_size, 0);
1350 *(struct exec_args_kva **)cookie = argkva;
1351 return (argkva->addr);
1355 exec_release_args_kva(struct exec_args_kva *argkva, u_int gen)
1359 base = argkva->addr;
1360 kasan_mark((void *)argkva->addr, 0, exec_map_entry_size,
1361 KASAN_EXEC_ARGS_FREED);
1362 if (argkva->gen != gen) {
1363 (void)vm_map_madvise(exec_map, base, base + exec_map_entry_size,
1367 if (!atomic_cmpset_ptr((uintptr_t *)DPCPU_PTR(exec_args_kva),
1368 (uintptr_t)NULL, (uintptr_t)argkva)) {
1369 mtx_lock(&exec_args_kva_mtx);
1370 SLIST_INSERT_HEAD(&exec_args_kva_freelist, argkva, next);
1371 wakeup_one(&exec_args_kva_freelist);
1372 mtx_unlock(&exec_args_kva_mtx);
1377 exec_free_args_kva(void *cookie)
1380 exec_release_args_kva(cookie, exec_args_gen);
1384 exec_args_kva_lowmem(void *arg __unused)
1386 SLIST_HEAD(, exec_args_kva) head;
1387 struct exec_args_kva *argkva;
1391 gen = atomic_fetchadd_int(&exec_args_gen, 1) + 1;
1394 * Force an madvise of each KVA range. Any currently allocated ranges
1395 * will have MADV_FREE applied once they are freed.
1398 mtx_lock(&exec_args_kva_mtx);
1399 SLIST_SWAP(&head, &exec_args_kva_freelist, exec_args_kva);
1400 mtx_unlock(&exec_args_kva_mtx);
1401 while ((argkva = SLIST_FIRST(&head)) != NULL) {
1402 SLIST_REMOVE_HEAD(&head, next);
1403 exec_release_args_kva(argkva, gen);
1407 argkva = (void *)atomic_readandclear_ptr(
1408 (uintptr_t *)DPCPU_ID_PTR(i, exec_args_kva));
1410 exec_release_args_kva(argkva, gen);
1413 EVENTHANDLER_DEFINE(vm_lowmem, exec_args_kva_lowmem, NULL,
1414 EVENTHANDLER_PRI_ANY);
1417 * Allocate temporary demand-paged, zero-filled memory for the file name,
1418 * argument, and environment strings.
1421 exec_alloc_args(struct image_args *args)
1424 args->buf = (char *)exec_alloc_args_kva(&args->bufkva);
1429 exec_free_args(struct image_args *args)
1432 if (args->buf != NULL) {
1433 exec_free_args_kva(args->bufkva);
1436 if (args->fname_buf != NULL) {
1437 free(args->fname_buf, M_TEMP);
1438 args->fname_buf = NULL;
1440 if (args->fdp != NULL)
1441 fdescfree_remapped(args->fdp);
1445 * A set to functions to fill struct image args.
1447 * NOTE: exec_args_add_fname() must be called (possibly with a NULL
1448 * fname) before the other functions. All exec_args_add_arg() calls must
1449 * be made before any exec_args_add_env() calls. exec_args_adjust_args()
1450 * may be called any time after exec_args_add_fname().
1452 * exec_args_add_fname() - install path to be executed
1453 * exec_args_add_arg() - append an argument string
1454 * exec_args_add_env() - append an env string
1455 * exec_args_adjust_args() - adjust location of the argument list to
1456 * allow new arguments to be prepended
1459 exec_args_add_fname(struct image_args *args, const char *fname,
1460 enum uio_seg segflg)
1465 KASSERT(args->fname == NULL, ("fname already appended"));
1466 KASSERT(args->endp == NULL, ("already appending to args"));
1468 if (fname != NULL) {
1469 args->fname = args->buf;
1470 error = segflg == UIO_SYSSPACE ?
1471 copystr(fname, args->fname, PATH_MAX, &length) :
1472 copyinstr(fname, args->fname, PATH_MAX, &length);
1474 return (error == ENAMETOOLONG ? E2BIG : error);
1478 /* Set up for _arg_*()/_env_*() */
1479 args->endp = args->buf + length;
1480 /* begin_argv must be set and kept updated */
1481 args->begin_argv = args->endp;
1482 KASSERT(exec_map_entry_size - length >= ARG_MAX,
1483 ("too little space remaining for arguments %zu < %zu",
1484 exec_map_entry_size - length, (size_t)ARG_MAX));
1485 args->stringspace = ARG_MAX;
1491 exec_args_add_str(struct image_args *args, const char *str,
1492 enum uio_seg segflg, int *countp)
1497 KASSERT(args->endp != NULL, ("endp not initialized"));
1498 KASSERT(args->begin_argv != NULL, ("begin_argp not initialized"));
1500 error = (segflg == UIO_SYSSPACE) ?
1501 copystr(str, args->endp, args->stringspace, &length) :
1502 copyinstr(str, args->endp, args->stringspace, &length);
1504 return (error == ENAMETOOLONG ? E2BIG : error);
1505 args->stringspace -= length;
1506 args->endp += length;
1513 exec_args_add_arg(struct image_args *args, const char *argp,
1514 enum uio_seg segflg)
1517 KASSERT(args->envc == 0, ("appending args after env"));
1519 return (exec_args_add_str(args, argp, segflg, &args->argc));
1523 exec_args_add_env(struct image_args *args, const char *envp,
1524 enum uio_seg segflg)
1527 if (args->envc == 0)
1528 args->begin_envv = args->endp;
1530 return (exec_args_add_str(args, envp, segflg, &args->envc));
1534 exec_args_adjust_args(struct image_args *args, size_t consume, ssize_t extend)
1538 KASSERT(args->endp != NULL, ("endp not initialized"));
1539 KASSERT(args->begin_argv != NULL, ("begin_argp not initialized"));
1541 offset = extend - consume;
1542 if (args->stringspace < offset)
1544 memmove(args->begin_argv + extend, args->begin_argv + consume,
1545 args->endp - args->begin_argv + consume);
1547 args->begin_envv += offset;
1548 args->endp += offset;
1549 args->stringspace -= offset;
1554 exec_args_get_begin_envv(struct image_args *args)
1557 KASSERT(args->endp != NULL, ("endp not initialized"));
1560 return (args->begin_envv);
1561 return (args->endp);
1565 exec_stackgap(struct image_params *imgp, uintptr_t *dp)
1567 if (imgp->sysent->sv_stackgap == NULL ||
1568 (imgp->proc->p_fctl0 & (NT_FREEBSD_FCTL_ASLR_DISABLE |
1569 NT_FREEBSD_FCTL_ASG_DISABLE)) != 0 ||
1570 (imgp->map_flags & MAP_ASLR) == 0)
1572 imgp->sysent->sv_stackgap(imgp, dp);
1576 * Copy strings out to the new process address space, constructing new arg
1577 * and env vector tables. Return a pointer to the base so that it can be used
1578 * as the initial stack pointer.
1581 exec_copyout_strings(struct image_params *imgp, uintptr_t *stack_base)
1586 uintptr_t destp, ustringp;
1587 struct ps_strings *arginfo;
1589 size_t execpath_len;
1590 int error, szsigcode, szps;
1591 char canary[sizeof(long) * 8];
1593 szps = sizeof(pagesizes[0]) * MAXPAGESIZES;
1595 * Calculate string base and vector table pointers.
1596 * Also deal with signal trampoline code for this exec type.
1598 if (imgp->execpath != NULL && imgp->auxargs != NULL)
1599 execpath_len = strlen(imgp->execpath) + 1;
1604 arginfo = (struct ps_strings *)p->p_sysent->sv_psstrings;
1605 imgp->ps_strings = arginfo;
1606 if (p->p_sysent->sv_sigcode_base == 0) {
1607 if (p->p_sysent->sv_szsigcode != NULL)
1608 szsigcode = *(p->p_sysent->sv_szsigcode);
1610 destp = (uintptr_t)arginfo;
1615 if (szsigcode != 0) {
1617 destp = rounddown2(destp, sizeof(void *));
1618 error = copyout(p->p_sysent->sv_sigcode, (void *)destp,
1625 * Copy the image path for the rtld.
1627 if (execpath_len != 0) {
1628 destp -= execpath_len;
1629 destp = rounddown2(destp, sizeof(void *));
1630 imgp->execpathp = (void *)destp;
1631 error = copyout(imgp->execpath, imgp->execpathp, execpath_len);
1637 * Prepare the canary for SSP.
1639 arc4rand(canary, sizeof(canary), 0);
1640 destp -= sizeof(canary);
1641 imgp->canary = (void *)destp;
1642 error = copyout(canary, imgp->canary, sizeof(canary));
1645 imgp->canarylen = sizeof(canary);
1648 * Prepare the pagesizes array.
1651 destp = rounddown2(destp, sizeof(void *));
1652 imgp->pagesizes = (void *)destp;
1653 error = copyout(pagesizes, imgp->pagesizes, szps);
1656 imgp->pagesizeslen = szps;
1659 * Allocate room for the argument and environment strings.
1661 destp -= ARG_MAX - imgp->args->stringspace;
1662 destp = rounddown2(destp, sizeof(void *));
1665 exec_stackgap(imgp, &destp);
1667 if (imgp->auxargs) {
1669 * Allocate room on the stack for the ELF auxargs
1670 * array. It has up to AT_COUNT entries.
1672 destp -= AT_COUNT * sizeof(Elf_Auxinfo);
1673 destp = rounddown2(destp, sizeof(void *));
1676 vectp = (char **)destp;
1679 * Allocate room for the argv[] and env vectors including the
1680 * terminating NULL pointers.
1682 vectp -= imgp->args->argc + 1 + imgp->args->envc + 1;
1685 * vectp also becomes our initial stack base
1687 *stack_base = (uintptr_t)vectp;
1689 stringp = imgp->args->begin_argv;
1690 argc = imgp->args->argc;
1691 envc = imgp->args->envc;
1694 * Copy out strings - arguments and environment.
1696 error = copyout(stringp, (void *)ustringp,
1697 ARG_MAX - imgp->args->stringspace);
1702 * Fill in "ps_strings" struct for ps, w, etc.
1705 if (suword(&arginfo->ps_argvstr, (long)(intptr_t)vectp) != 0 ||
1706 suword32(&arginfo->ps_nargvstr, argc) != 0)
1710 * Fill in argument portion of vector table.
1712 for (; argc > 0; --argc) {
1713 if (suword(vectp++, ustringp) != 0)
1715 while (*stringp++ != 0)
1720 /* a null vector table pointer separates the argp's from the envp's */
1721 if (suword(vectp++, 0) != 0)
1725 if (suword(&arginfo->ps_envstr, (long)(intptr_t)vectp) != 0 ||
1726 suword32(&arginfo->ps_nenvstr, envc) != 0)
1730 * Fill in environment portion of vector table.
1732 for (; envc > 0; --envc) {
1733 if (suword(vectp++, ustringp) != 0)
1735 while (*stringp++ != 0)
1740 /* end of vector table is a null pointer */
1741 if (suword(vectp, 0) != 0)
1744 if (imgp->auxargs) {
1746 error = imgp->sysent->sv_copyout_auxargs(imgp,
1756 * Check permissions of file to execute.
1757 * Called with imgp->vp locked.
1758 * Return 0 for success or error code on failure.
1761 exec_check_permissions(struct image_params *imgp)
1763 struct vnode *vp = imgp->vp;
1764 struct vattr *attr = imgp->attr;
1770 /* Get file attributes */
1771 error = VOP_GETATTR(vp, attr, td->td_ucred);
1776 error = mac_vnode_check_exec(td->td_ucred, imgp->vp, imgp);
1782 * 1) Check if file execution is disabled for the filesystem that
1783 * this file resides on.
1784 * 2) Ensure that at least one execute bit is on. Otherwise, a
1785 * privileged user will always succeed, and we don't want this
1786 * to happen unless the file really is executable.
1787 * 3) Ensure that the file is a regular file.
1789 if ((vp->v_mount->mnt_flag & MNT_NOEXEC) ||
1790 (attr->va_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) == 0 ||
1791 (attr->va_type != VREG))
1795 * Zero length files can't be exec'd
1797 if (attr->va_size == 0)
1801 * Check for execute permission to file based on current credentials.
1803 error = VOP_ACCESS(vp, VEXEC, td->td_ucred, td);
1808 * Check number of open-for-writes on the file and deny execution
1811 * Add a text reference now so no one can write to the
1812 * executable while we're activating it.
1814 * Remember if this was set before and unset it in case this is not
1815 * actually an executable image.
1817 error = VOP_SET_TEXT(vp);
1820 imgp->textset = true;
1823 * Call filesystem specific open routine (which does nothing in the
1826 error = VOP_OPEN(vp, FREAD, td->td_ucred, td, NULL);
1833 * Exec handler registration
1836 exec_register(const struct execsw *execsw_arg)
1838 const struct execsw **es, **xs, **newexecsw;
1839 u_int count = 2; /* New slot and trailing NULL */
1842 for (es = execsw; *es; es++)
1844 newexecsw = malloc(count * sizeof(*es), M_TEMP, M_WAITOK);
1847 for (es = execsw; *es; es++)
1852 free(execsw, M_TEMP);
1858 exec_unregister(const struct execsw *execsw_arg)
1860 const struct execsw **es, **xs, **newexecsw;
1864 panic("unregister with no handlers left?\n");
1866 for (es = execsw; *es; es++) {
1867 if (*es == execsw_arg)
1872 for (es = execsw; *es; es++)
1873 if (*es != execsw_arg)
1875 newexecsw = malloc(count * sizeof(*es), M_TEMP, M_WAITOK);
1877 for (es = execsw; *es; es++)
1878 if (*es != execsw_arg)
1882 free(execsw, M_TEMP);
1888 * Write out a core segment to the compression stream.
1891 compress_chunk(struct coredump_params *cp, char *base, char *buf, u_int len)
1897 chunk_len = MIN(len, CORE_BUF_SIZE);
1900 * We can get EFAULT error here.
1901 * In that case zero out the current chunk of the segment.
1903 error = copyin(base, buf, chunk_len);
1905 bzero(buf, chunk_len);
1906 error = compressor_write(cp->comp, buf, chunk_len);
1916 core_write(struct coredump_params *cp, const void *base, size_t len,
1917 off_t offset, enum uio_seg seg, size_t *resid)
1920 return (vn_rdwr_inchunks(UIO_WRITE, cp->vp, __DECONST(void *, base),
1921 len, offset, seg, IO_UNIT | IO_DIRECT | IO_RANGELOCKED,
1922 cp->active_cred, cp->file_cred, resid, cp->td));
1926 core_output(char *base, size_t len, off_t offset, struct coredump_params *cp,
1931 size_t resid, runlen;
1935 KASSERT((uintptr_t)base % PAGE_SIZE == 0,
1936 ("%s: user address %p is not page-aligned", __func__, base));
1938 if (cp->comp != NULL)
1939 return (compress_chunk(cp, base, tmpbuf, len));
1941 map = &cp->td->td_proc->p_vmspace->vm_map;
1942 for (; len > 0; base += runlen, offset += runlen, len -= runlen) {
1944 * Attempt to page in all virtual pages in the range. If a
1945 * virtual page is not backed by the pager, it is represented as
1946 * a hole in the file. This can occur with zero-filled
1947 * anonymous memory or truncated files, for example.
1949 for (runlen = 0; runlen < len; runlen += PAGE_SIZE) {
1950 error = vm_fault(map, (uintptr_t)base + runlen,
1951 VM_PROT_READ, VM_FAULT_NOFILL, NULL);
1953 success = error == KERN_SUCCESS;
1954 else if ((error == KERN_SUCCESS) != success)
1959 error = core_write(cp, base, runlen, offset,
1960 UIO_USERSPACE, &resid);
1962 if (error != EFAULT)
1966 * EFAULT may be returned if the user mapping
1967 * could not be accessed, e.g., because a mapped
1968 * file has been truncated. Skip the page if no
1969 * progress was made, to protect against a
1970 * hypothetical scenario where vm_fault() was
1971 * successful but core_write() returns EFAULT
1982 error = vn_start_write(cp->vp, &mp, V_WAIT);
1985 vn_lock(cp->vp, LK_EXCLUSIVE | LK_RETRY);
1986 error = vn_truncate_locked(cp->vp, offset + runlen,
1987 false, cp->td->td_ucred);
1989 vn_finished_write(mp);
1998 * Drain into a core file.
2001 sbuf_drain_core_output(void *arg, const char *data, int len)
2003 struct coredump_params *cp;
2008 p = cp->td->td_proc;
2011 * Some kern_proc out routines that print to this sbuf may
2012 * call us with the process lock held. Draining with the
2013 * non-sleepable lock held is unsafe. The lock is needed for
2014 * those routines when dumping a live process. In our case we
2015 * can safely release the lock before draining and acquire
2018 locked = PROC_LOCKED(p);
2021 if (cp->comp != NULL)
2022 error = compressor_write(cp->comp, __DECONST(char *, data), len);
2024 error = core_write(cp, __DECONST(void *, data), len, cp->offset,
2025 UIO_SYSSPACE, NULL);