2 * Copyright (c) 1993, David Greenman
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
30 #include "opt_capsicum.h"
31 #include "opt_hwpmc_hooks.h"
32 #include "opt_ktrace.h"
35 #include <sys/param.h>
36 #include <sys/capsicum.h>
37 #include <sys/systm.h>
38 #include <sys/eventhandler.h>
40 #include <sys/mutex.h>
41 #include <sys/sysproto.h>
42 #include <sys/signalvar.h>
43 #include <sys/kernel.h>
44 #include <sys/mount.h>
45 #include <sys/filedesc.h>
46 #include <sys/fcntl.h>
49 #include <sys/imgact.h>
50 #include <sys/imgact_elf.h>
52 #include <sys/malloc.h>
55 #include <sys/pioctl.h>
56 #include <sys/namei.h>
57 #include <sys/resourcevar.h>
58 #include <sys/rwlock.h>
59 #include <sys/sched.h>
61 #include <sys/sf_buf.h>
62 #include <sys/syscallsubr.h>
63 #include <sys/sysent.h>
65 #include <sys/sysctl.h>
66 #include <sys/vnode.h>
69 #include <sys/ktrace.h>
73 #include <vm/vm_param.h>
75 #include <vm/vm_page.h>
76 #include <vm/vm_map.h>
77 #include <vm/vm_kern.h>
78 #include <vm/vm_extern.h>
79 #include <vm/vm_object.h>
80 #include <vm/vm_pager.h>
83 #include <sys/pmckern.h>
86 #include <machine/reg.h>
88 #include <security/audit/audit.h>
89 #include <security/mac/mac_framework.h>
92 #include <sys/dtrace_bsd.h>
93 dtrace_execexit_func_t dtrace_fasttrap_exec;
96 SDT_PROVIDER_DECLARE(proc);
97 SDT_PROBE_DEFINE1(proc, kernel, , exec, "char *");
98 SDT_PROBE_DEFINE1(proc, kernel, , exec__failure, "int");
99 SDT_PROBE_DEFINE1(proc, kernel, , exec__success, "char *");
101 MALLOC_DEFINE(M_PARGS, "proc-args", "Process arguments");
103 static int sysctl_kern_ps_strings(SYSCTL_HANDLER_ARGS);
104 static int sysctl_kern_usrstack(SYSCTL_HANDLER_ARGS);
105 static int sysctl_kern_stackprot(SYSCTL_HANDLER_ARGS);
106 static int do_execve(struct thread *td, struct image_args *args,
109 /* XXX This should be vm_size_t. */
110 SYSCTL_PROC(_kern, KERN_PS_STRINGS, ps_strings, CTLTYPE_ULONG|CTLFLAG_RD,
111 NULL, 0, sysctl_kern_ps_strings, "LU", "");
113 /* XXX This should be vm_size_t. */
114 SYSCTL_PROC(_kern, KERN_USRSTACK, usrstack, CTLTYPE_ULONG|CTLFLAG_RD|
115 CTLFLAG_CAPRD, NULL, 0, sysctl_kern_usrstack, "LU", "");
117 SYSCTL_PROC(_kern, OID_AUTO, stackprot, CTLTYPE_INT|CTLFLAG_RD,
118 NULL, 0, sysctl_kern_stackprot, "I", "");
120 u_long ps_arg_cache_limit = PAGE_SIZE / 16;
121 SYSCTL_ULONG(_kern, OID_AUTO, ps_arg_cache_limit, CTLFLAG_RW,
122 &ps_arg_cache_limit, 0, "");
124 static int disallow_high_osrel;
125 SYSCTL_INT(_kern, OID_AUTO, disallow_high_osrel, CTLFLAG_RW,
126 &disallow_high_osrel, 0,
127 "Disallow execution of binaries built for higher version of the world");
129 static int map_at_zero = 0;
130 TUNABLE_INT("security.bsd.map_at_zero", &map_at_zero);
131 SYSCTL_INT(_security_bsd, OID_AUTO, map_at_zero, CTLFLAG_RW, &map_at_zero, 0,
132 "Permit processes to map an object at virtual address 0.");
135 sysctl_kern_ps_strings(SYSCTL_HANDLER_ARGS)
142 if (req->flags & SCTL_MASK32) {
144 val = (unsigned int)p->p_sysent->sv_psstrings;
145 error = SYSCTL_OUT(req, &val, sizeof(val));
148 error = SYSCTL_OUT(req, &p->p_sysent->sv_psstrings,
149 sizeof(p->p_sysent->sv_psstrings));
154 sysctl_kern_usrstack(SYSCTL_HANDLER_ARGS)
161 if (req->flags & SCTL_MASK32) {
163 val = (unsigned int)p->p_sysent->sv_usrstack;
164 error = SYSCTL_OUT(req, &val, sizeof(val));
167 error = SYSCTL_OUT(req, &p->p_sysent->sv_usrstack,
168 sizeof(p->p_sysent->sv_usrstack));
173 sysctl_kern_stackprot(SYSCTL_HANDLER_ARGS)
178 return (SYSCTL_OUT(req, &p->p_sysent->sv_stackprot,
179 sizeof(p->p_sysent->sv_stackprot)));
183 * Each of the items is a pointer to a `const struct execsw', hence the
184 * double pointer here.
186 static const struct execsw **execsw;
188 #ifndef _SYS_SYSPROTO_H_
199 struct execve_args /* {
206 struct image_args args;
208 error = exec_copyin_args(&args, uap->fname, UIO_USERSPACE,
209 uap->argv, uap->envv);
211 error = kern_execve(td, &args, NULL);
215 #ifndef _SYS_SYSPROTO_H_
216 struct fexecve_args {
223 sys_fexecve(struct thread *td, struct fexecve_args *uap)
226 struct image_args args;
228 error = exec_copyin_args(&args, NULL, UIO_SYSSPACE,
229 uap->argv, uap->envv);
232 error = kern_execve(td, &args, NULL);
237 #ifndef _SYS_SYSPROTO_H_
238 struct __mac_execve_args {
247 sys___mac_execve(td, uap)
249 struct __mac_execve_args /* {
258 struct image_args args;
260 error = exec_copyin_args(&args, uap->fname, UIO_USERSPACE,
261 uap->argv, uap->envv);
263 error = kern_execve(td, &args, uap->mac_p);
271 * XXX: kern_execve has the astonishing property of not always returning to
272 * the caller. If sufficiently bad things happen during the call to
273 * do_execve(), it can end up calling exit1(); as a result, callers must
274 * avoid doing anything which they might need to undo (e.g., allocating
278 kern_execve(td, args, mac_p)
280 struct image_args *args;
283 struct proc *p = td->td_proc;
284 struct vmspace *oldvmspace;
287 AUDIT_ARG_ARGV(args->begin_argv, args->argc,
288 args->begin_envv - args->begin_argv);
289 AUDIT_ARG_ENVV(args->begin_envv, args->envc,
290 args->endp - args->begin_envv);
291 if (p->p_flag & P_HADTHREADS) {
293 if (thread_single(SINGLE_BOUNDARY)) {
295 exec_free_args(args);
296 return (ERESTART); /* Try again later. */
301 KASSERT((td->td_pflags & TDP_EXECVMSPC) == 0, ("nested execve"));
302 oldvmspace = td->td_proc->p_vmspace;
303 error = do_execve(td, args, mac_p);
305 if (p->p_flag & P_HADTHREADS) {
308 * If success, we upgrade to SINGLE_EXIT state to
309 * force other threads to suicide.
312 thread_single(SINGLE_EXIT);
317 if ((td->td_pflags & TDP_EXECVMSPC) != 0) {
318 KASSERT(td->td_proc->p_vmspace != oldvmspace,
319 ("oldvmspace still used"));
320 vmspace_free(oldvmspace);
321 td->td_pflags &= ~TDP_EXECVMSPC;
328 * In-kernel implementation of execve(). All arguments are assumed to be
329 * userspace pointers from the passed thread.
332 do_execve(td, args, mac_p)
334 struct image_args *args;
337 struct proc *p = td->td_proc;
339 struct ucred *newcred = NULL, *oldcred;
340 struct uidinfo *euip;
341 register_t *stack_base;
343 struct image_params image_params, *imgp;
345 int (*img_first)(struct image_params *);
346 struct pargs *oldargs = NULL, *newargs = NULL;
347 struct sigacts *oldsigacts, *newsigacts;
349 struct vnode *tracevp = NULL;
350 struct ucred *tracecred = NULL;
352 struct vnode *textvp = NULL, *binvp = NULL;
354 int credential_changing;
357 struct label *interpvplabel = NULL;
361 struct pmckern_procexec pe;
363 static const char fexecv_proc_title[] = "(fexecv)";
365 imgp = &image_params;
368 * Lock the process and set the P_INEXEC flag to indicate that
369 * it should be left alone until we're done here. This is
370 * necessary to avoid race conditions - e.g. in ptrace() -
371 * that might allow a local user to illicitly obtain elevated
375 KASSERT((p->p_flag & P_INEXEC) == 0,
376 ("%s(): process already has P_INEXEC flag", __func__));
377 p->p_flag |= P_INEXEC;
381 * Initialize part of the common data
384 imgp->execlabel = NULL;
386 imgp->entry_addr = 0;
387 imgp->reloc_base = 0;
388 imgp->vmspace_destroyed = 0;
389 imgp->interpreted = 0;
391 imgp->interpreter_name = NULL;
392 imgp->auxargs = NULL;
395 imgp->firstpage = NULL;
396 imgp->ps_strings = 0;
397 imgp->auxarg_size = 0;
399 imgp->execpath = imgp->freepath = NULL;
404 imgp->pagesizeslen = 0;
405 imgp->stack_prot = 0;
408 error = mac_execve_enter(imgp, mac_p);
413 imgp->image_header = NULL;
416 * Translate the file name. namei() returns a vnode pointer
417 * in ni_vp amoung other things.
419 * XXXAUDIT: It would be desirable to also audit the name of the
420 * interpreter if this is an interpreted binary.
422 if (args->fname != NULL) {
423 NDINIT(&nd, LOOKUP, ISOPEN | LOCKLEAF | FOLLOW | SAVENAME
424 | AUDITVNODE1, UIO_SYSSPACE, args->fname, td);
427 SDT_PROBE(proc, kernel, , exec, args->fname, 0, 0, 0, 0 );
430 if (args->fname != NULL) {
431 #ifdef CAPABILITY_MODE
433 * While capability mode can't reach this point via direct
434 * path arguments to execve(), we also don't allow
435 * interpreters to be used in capability mode (for now).
436 * Catch indirect lookups and return a permissions error.
438 if (IN_CAPABILITY_MODE(td)) {
450 AUDIT_ARG_FD(args->fd);
452 * Descriptors opened only with O_EXEC or O_RDONLY are allowed.
454 error = fgetvp_exec(td, args->fd,
455 cap_rights_init(&rights, CAP_FEXECVE), &binvp);
458 vn_lock(binvp, LK_EXCLUSIVE | LK_RETRY);
459 AUDIT_ARG_VNODE1(binvp);
464 * Check file permissions (also 'opens' file)
466 error = exec_check_permissions(imgp);
468 goto exec_fail_dealloc;
470 imgp->object = imgp->vp->v_object;
471 if (imgp->object != NULL)
472 vm_object_reference(imgp->object);
475 * Set VV_TEXT now so no one can write to the executable while we're
478 * Remember if this was set before and unset it in case this is not
479 * actually an executable image.
481 textset = VOP_IS_TEXT(imgp->vp);
482 VOP_SET_TEXT(imgp->vp);
484 error = exec_map_first_page(imgp);
486 goto exec_fail_dealloc;
488 imgp->proc->p_osrel = 0;
490 * If the current process has a special image activator it
491 * wants to try first, call it. For example, emulating shell
492 * scripts differently.
495 if ((img_first = imgp->proc->p_sysent->sv_imgact_try) != NULL)
496 error = img_first(imgp);
499 * Loop through the list of image activators, calling each one.
500 * An activator returns -1 if there is no match, 0 on success,
501 * and an error otherwise.
503 for (i = 0; error == -1 && execsw[i]; ++i) {
504 if (execsw[i]->ex_imgact == NULL ||
505 execsw[i]->ex_imgact == img_first) {
508 error = (*execsw[i]->ex_imgact)(imgp);
514 VOP_UNSET_TEXT(imgp->vp);
517 goto exec_fail_dealloc;
521 * Special interpreter operation, cleanup and loop up to try to
522 * activate the interpreter.
524 if (imgp->interpreted) {
525 exec_unmap_first_page(imgp);
527 * VV_TEXT needs to be unset for scripts. There is a short
528 * period before we determine that something is a script where
529 * VV_TEXT will be set. The vnode lock is held over this
530 * entire period so nothing should illegitimately be blocked.
532 VOP_UNSET_TEXT(imgp->vp);
533 /* free name buffer and old vnode */
534 if (args->fname != NULL)
535 NDFREE(&nd, NDF_ONLY_PNBUF);
537 mac_execve_interpreter_enter(binvp, &interpvplabel);
540 VOP_CLOSE(binvp, FREAD, td->td_ucred, td);
544 vm_object_deallocate(imgp->object);
546 /* set new name to that of the interpreter */
547 NDINIT(&nd, LOOKUP, LOCKLEAF | FOLLOW | SAVENAME,
548 UIO_SYSSPACE, imgp->interpreter_name, td);
549 args->fname = imgp->interpreter_name;
554 * NB: We unlock the vnode here because it is believed that none
555 * of the sv_copyout_strings/sv_fixup operations require the vnode.
557 VOP_UNLOCK(imgp->vp, 0);
560 * Do the best to calculate the full path to the image file.
562 if (imgp->auxargs != NULL &&
563 ((args->fname != NULL && args->fname[0] == '/') ||
564 vn_fullpath(td, imgp->vp, &imgp->execpath, &imgp->freepath) != 0))
565 imgp->execpath = args->fname;
567 if (disallow_high_osrel &&
568 P_OSREL_MAJOR(p->p_osrel) > P_OSREL_MAJOR(__FreeBSD_version)) {
570 uprintf("Osrel %d for image %s too high\n", p->p_osrel,
571 imgp->execpath != NULL ? imgp->execpath : "<unresolved>");
572 vn_lock(imgp->vp, LK_SHARED | LK_RETRY);
573 goto exec_fail_dealloc;
577 * Copy out strings (args and env) and initialize stack base
579 if (p->p_sysent->sv_copyout_strings)
580 stack_base = (*p->p_sysent->sv_copyout_strings)(imgp);
582 stack_base = exec_copyout_strings(imgp);
585 * If custom stack fixup routine present for this process
586 * let it do the stack setup.
587 * Else stuff argument count as first item on stack
589 if (p->p_sysent->sv_fixup != NULL)
590 (*p->p_sysent->sv_fixup)(&stack_base, imgp);
592 suword(--stack_base, imgp->args->argc);
595 * For security and other reasons, the file descriptor table cannot
596 * be shared after an exec.
601 * Malloc things before we need locks.
604 euip = uifind(attr.va_uid);
605 i = imgp->args->begin_envv - imgp->args->begin_argv;
606 /* Cache arguments if they fit inside our allowance */
607 if (ps_arg_cache_limit >= i + sizeof(struct pargs)) {
608 newargs = pargs_alloc(i);
609 bcopy(imgp->args->begin_argv, newargs->ar_args, i);
612 /* close files on exec */
614 vn_lock(imgp->vp, LK_SHARED | LK_RETRY);
616 /* Get a reference to the vnode prior to locking the proc */
620 * For security and other reasons, signal handlers cannot
621 * be shared after an exec. The new process gets a copy of the old
622 * handlers. In execsigs(), the new process will have its signals
626 oldcred = crcopysafe(p, newcred);
627 if (sigacts_shared(p->p_sigacts)) {
628 oldsigacts = p->p_sigacts;
630 newsigacts = sigacts_alloc();
631 sigacts_copy(newsigacts, oldsigacts);
633 p->p_sigacts = newsigacts;
640 /* reset caught signals */
643 /* name this process - nameiexec(p, ndp) */
644 bzero(p->p_comm, sizeof(p->p_comm));
646 bcopy(nd.ni_cnd.cn_nameptr, p->p_comm,
647 min(nd.ni_cnd.cn_namelen, MAXCOMLEN));
648 else if (vn_commname(binvp, p->p_comm, sizeof(p->p_comm)) != 0)
649 bcopy(fexecv_proc_title, p->p_comm, sizeof(fexecv_proc_title));
650 bcopy(p->p_comm, td->td_name, sizeof(td->td_name));
652 sched_clear_tdname(td);
656 * mark as execed, wakeup the process that vforked (if any) and tell
657 * it that it now has its own resources back
660 if (p->p_pptr && (p->p_flag & P_PPWAIT)) {
661 p->p_flag &= ~(P_PPWAIT | P_PPTRACE);
662 cv_broadcast(&p->p_pwait);
666 * Implement image setuid/setgid.
668 * Don't honor setuid/setgid if the filesystem prohibits it or if
669 * the process is being traced.
671 * We disable setuid/setgid/etc in compatibility mode on the basis
672 * that most setugid applications are not written with that
673 * environment in mind, and will therefore almost certainly operate
674 * incorrectly. In principle there's no reason that setugid
675 * applications might not be useful in capability mode, so we may want
676 * to reconsider this conservative design choice in the future.
678 * XXXMAC: For the time being, use NOSUID to also prohibit
679 * transitions on the file system.
681 credential_changing = 0;
682 credential_changing |= (attr.va_mode & S_ISUID) && oldcred->cr_uid !=
684 credential_changing |= (attr.va_mode & S_ISGID) && oldcred->cr_gid !=
687 will_transition = mac_vnode_execve_will_transition(oldcred, imgp->vp,
688 interpvplabel, imgp);
689 credential_changing |= will_transition;
692 if (credential_changing &&
693 #ifdef CAPABILITY_MODE
694 ((oldcred->cr_flags & CRED_FLAG_CAPMODE) == 0) &&
696 (imgp->vp->v_mount->mnt_flag & MNT_NOSUID) == 0 &&
697 (p->p_flag & P_TRACED) == 0) {
699 * Turn off syscall tracing for set-id programs, except for
700 * root. Record any set-id flags first to make sure that
701 * we do not regain any tracing during a possible block.
706 if (p->p_tracecred != NULL &&
707 priv_check_cred(p->p_tracecred, PRIV_DEBUG_DIFFCRED, 0))
708 ktrprocexec(p, &tracecred, &tracevp);
711 * Close any file descriptors 0..2 that reference procfs,
712 * then make sure file descriptors 0..2 are in use.
714 * setugidsafety() may call closef() and then pfind()
715 * which may grab the process lock.
716 * fdcheckstd() may call falloc() which may block to
717 * allocate memory, so temporarily drop the process lock.
720 VOP_UNLOCK(imgp->vp, 0);
722 error = fdcheckstd(td);
723 vn_lock(imgp->vp, LK_SHARED | LK_RETRY);
728 * Set the new credentials.
730 if (attr.va_mode & S_ISUID)
731 change_euid(newcred, euip);
732 if (attr.va_mode & S_ISGID)
733 change_egid(newcred, attr.va_gid);
735 if (will_transition) {
736 mac_vnode_execve_transition(oldcred, newcred, imgp->vp,
737 interpvplabel, imgp);
741 * Implement correct POSIX saved-id behavior.
743 * XXXMAC: Note that the current logic will save the
744 * uid and gid if a MAC domain transition occurs, even
745 * though maybe it shouldn't.
747 change_svuid(newcred, newcred->cr_uid);
748 change_svgid(newcred, newcred->cr_gid);
749 p->p_ucred = newcred;
752 if (oldcred->cr_uid == oldcred->cr_ruid &&
753 oldcred->cr_gid == oldcred->cr_rgid)
754 p->p_flag &= ~P_SUGID;
756 * Implement correct POSIX saved-id behavior.
758 * XXX: It's not clear that the existing behavior is
759 * POSIX-compliant. A number of sources indicate that the
760 * saved uid/gid should only be updated if the new ruid is
761 * not equal to the old ruid, or the new euid is not equal
762 * to the old euid and the new euid is not equal to the old
763 * ruid. The FreeBSD code always updates the saved uid/gid.
764 * Also, this code uses the new (replaced) euid and egid as
765 * the source, which may or may not be the right ones to use.
767 if (oldcred->cr_svuid != oldcred->cr_uid ||
768 oldcred->cr_svgid != oldcred->cr_gid) {
769 change_svuid(newcred, newcred->cr_uid);
770 change_svgid(newcred, newcred->cr_gid);
771 p->p_ucred = newcred;
777 * Store the vp for use in procfs. This vnode was referenced prior
778 * to locking the proc lock.
780 textvp = p->p_textvp;
785 * Tell the DTrace fasttrap provider about the exec if it
786 * has declared an interest.
788 if (dtrace_fasttrap_exec)
789 dtrace_fasttrap_exec(p);
793 * Notify others that we exec'd, and clear the P_INEXEC flag
794 * as we're now a bona fide freshly-execed process.
796 KNOTE_LOCKED(&p->p_klist, NOTE_EXEC);
797 p->p_flag &= ~P_INEXEC;
799 /* clear "fork but no exec" flag, as we _are_ execing */
800 p->p_acflag &= ~AFORK;
803 * Free any previous argument cache and replace it with
804 * the new argument cache, if any.
812 * Check if system-wide sampling is in effect or if the
813 * current process is using PMCs. If so, do exec() time
814 * processing. This processing needs to happen AFTER the
815 * P_INEXEC flag is cleared.
817 * The proc lock needs to be released before taking the PMC
820 if (PMC_SYSTEM_SAMPLING_ACTIVE() || PMC_PROC_IS_USING_PMCS(p)) {
822 VOP_UNLOCK(imgp->vp, 0);
823 pe.pm_credentialschanged = credential_changing;
824 pe.pm_entryaddr = imgp->entry_addr;
826 PMC_CALL_HOOK_X(td, PMC_FN_PROCESS_EXEC, (void *) &pe);
827 vn_lock(imgp->vp, LK_SHARED | LK_RETRY);
830 #else /* !HWPMC_HOOKS */
834 /* Set values passed into the program in registers. */
835 if (p->p_sysent->sv_setregs)
836 (*p->p_sysent->sv_setregs)(td, imgp,
837 (u_long)(uintptr_t)stack_base);
839 exec_setregs(td, imgp, (u_long)(uintptr_t)stack_base);
841 vfs_mark_atime(imgp->vp, td->td_ucred);
843 SDT_PROBE(proc, kernel, , exec__success, args->fname, 0, 0, 0, 0);
847 * Free any resources malloc'd earlier that we didn't use.
854 VOP_UNLOCK(imgp->vp, 0);
857 * Handle deferred decrement of ref counts.
861 if (binvp && error != 0)
866 if (tracecred != NULL)
869 vn_lock(imgp->vp, LK_SHARED | LK_RETRY);
872 if (oldsigacts != NULL)
873 sigacts_free(oldsigacts);
878 * free various allocated resources
880 if (imgp->firstpage != NULL)
881 exec_unmap_first_page(imgp);
883 if (imgp->vp != NULL) {
885 NDFREE(&nd, NDF_ONLY_PNBUF);
887 VOP_CLOSE(imgp->vp, FREAD, td->td_ucred, td);
891 if (imgp->object != NULL)
892 vm_object_deallocate(imgp->object);
894 free(imgp->freepath, M_TEMP);
898 td->td_dbgflags |= TDB_EXEC;
902 * Stop the process here if its stop event mask has
903 * the S_EXEC bit set.
905 STOPEVENT(p, S_EXEC, 0);
910 /* we're done here, clear P_INEXEC */
912 p->p_flag &= ~P_INEXEC;
915 SDT_PROBE(proc, kernel, , exec__failure, error, 0, 0, 0, 0);
919 mac_execve_exit(imgp);
920 mac_execve_interpreter_exit(interpvplabel);
922 exec_free_args(args);
924 if (error && imgp->vmspace_destroyed) {
925 /* sorry, no more process anymore. exit gracefully */
926 exit1(td, W_EXITCODE(0, SIGABRT));
939 exec_map_first_page(imgp)
940 struct image_params *imgp;
944 vm_page_t ma[VM_INITIAL_PAGEIN];
947 if (imgp->firstpage != NULL)
948 exec_unmap_first_page(imgp);
950 object = imgp->vp->v_object;
953 VM_OBJECT_WLOCK(object);
954 #if VM_NRESERVLEVEL > 0
955 if ((object->flags & OBJ_COLORED) == 0) {
956 object->flags |= OBJ_COLORED;
957 object->pg_color = 0;
960 ma[0] = vm_page_grab(object, 0, VM_ALLOC_NORMAL);
961 if (ma[0]->valid != VM_PAGE_BITS_ALL) {
962 initial_pagein = VM_INITIAL_PAGEIN;
963 if (initial_pagein > object->size)
964 initial_pagein = object->size;
965 for (i = 1; i < initial_pagein; i++) {
966 if ((ma[i] = vm_page_next(ma[i - 1])) != NULL) {
969 if (vm_page_tryxbusy(ma[i]))
972 ma[i] = vm_page_alloc(object, i,
973 VM_ALLOC_NORMAL | VM_ALLOC_IFNOTCACHED);
979 rv = vm_pager_get_pages(object, ma, initial_pagein, 0);
980 ma[0] = vm_page_lookup(object, 0);
981 if ((rv != VM_PAGER_OK) || (ma[0] == NULL)) {
985 vm_page_unlock(ma[0]);
987 VM_OBJECT_WUNLOCK(object);
991 vm_page_xunbusy(ma[0]);
994 vm_page_unlock(ma[0]);
995 VM_OBJECT_WUNLOCK(object);
997 imgp->firstpage = sf_buf_alloc(ma[0], 0);
998 imgp->image_header = (char *)sf_buf_kva(imgp->firstpage);
1004 exec_unmap_first_page(imgp)
1005 struct image_params *imgp;
1009 if (imgp->firstpage != NULL) {
1010 m = sf_buf_page(imgp->firstpage);
1011 sf_buf_free(imgp->firstpage);
1012 imgp->firstpage = NULL;
1020 * Destroy old address space, and allocate a new stack
1021 * The new stack is only SGROWSIZ large because it is grown
1022 * automatically in trap.c.
1025 exec_new_vmspace(imgp, sv)
1026 struct image_params *imgp;
1027 struct sysentvec *sv;
1030 struct proc *p = imgp->proc;
1031 struct vmspace *vmspace = p->p_vmspace;
1033 vm_offset_t sv_minuser, stack_addr;
1037 imgp->vmspace_destroyed = 1;
1040 /* May be called with Giant held */
1041 EVENTHANDLER_INVOKE(process_exec, p, imgp);
1044 * Blow away entire process VM, if address space not shared,
1045 * otherwise, create a new VM space so that other threads are
1048 map = &vmspace->vm_map;
1050 sv_minuser = sv->sv_minuser;
1052 sv_minuser = MAX(sv->sv_minuser, PAGE_SIZE);
1053 if (vmspace->vm_refcnt == 1 && vm_map_min(map) == sv_minuser &&
1054 vm_map_max(map) == sv->sv_maxuser) {
1056 pmap_remove_pages(vmspace_pmap(vmspace));
1057 vm_map_remove(map, vm_map_min(map), vm_map_max(map));
1059 error = vmspace_exec(p, sv_minuser, sv->sv_maxuser);
1062 vmspace = p->p_vmspace;
1063 map = &vmspace->vm_map;
1066 /* Map a shared page */
1067 obj = sv->sv_shared_page_obj;
1069 vm_object_reference(obj);
1070 error = vm_map_fixed(map, obj, 0,
1071 sv->sv_shared_page_base, sv->sv_shared_page_len,
1072 VM_PROT_READ | VM_PROT_EXECUTE,
1073 VM_PROT_READ | VM_PROT_EXECUTE,
1074 MAP_INHERIT_SHARE | MAP_ACC_NO_CHARGE);
1076 vm_object_deallocate(obj);
1081 /* Allocate a new stack */
1082 if (sv->sv_maxssiz != NULL)
1083 ssiz = *sv->sv_maxssiz;
1086 stack_addr = sv->sv_usrstack - ssiz;
1087 error = vm_map_stack(map, stack_addr, (vm_size_t)ssiz,
1088 obj != NULL && imgp->stack_prot != 0 ? imgp->stack_prot :
1090 VM_PROT_ALL, MAP_STACK_GROWS_DOWN);
1095 /* Allocate a new register stack */
1096 stack_addr = IA64_BACKINGSTORE;
1097 error = vm_map_stack(map, stack_addr, (vm_size_t)ssiz,
1098 sv->sv_stackprot, VM_PROT_ALL, MAP_STACK_GROWS_UP);
1104 * vm_ssize and vm_maxsaddr are somewhat antiquated concepts, but they
1105 * are still used to enforce the stack rlimit on the process stack.
1107 vmspace->vm_ssize = sgrowsiz >> PAGE_SHIFT;
1108 vmspace->vm_maxsaddr = (char *)sv->sv_usrstack - ssiz;
1114 * Copy out argument and environment strings from the old process address
1115 * space into the temporary string buffer.
1118 exec_copyin_args(struct image_args *args, char *fname,
1119 enum uio_seg segflg, char **argv, char **envv)
1125 bzero(args, sizeof(*args));
1130 * Allocate demand-paged memory for the file name, argument, and
1131 * environment strings.
1133 error = exec_alloc_args(args);
1138 * Copy the file name.
1140 if (fname != NULL) {
1141 args->fname = args->buf;
1142 error = (segflg == UIO_SYSSPACE) ?
1143 copystr(fname, args->fname, PATH_MAX, &length) :
1144 copyinstr(fname, args->fname, PATH_MAX, &length);
1150 args->begin_argv = args->buf + length;
1151 args->endp = args->begin_argv;
1152 args->stringspace = ARG_MAX;
1155 * extract arguments first
1157 while ((argp = (caddr_t) (intptr_t) fuword(argv++))) {
1158 if (argp == (caddr_t) -1) {
1162 if ((error = copyinstr(argp, args->endp,
1163 args->stringspace, &length))) {
1164 if (error == ENAMETOOLONG)
1168 args->stringspace -= length;
1169 args->endp += length;
1173 args->begin_envv = args->endp;
1176 * extract environment strings
1179 while ((envp = (caddr_t)(intptr_t)fuword(envv++))) {
1180 if (envp == (caddr_t)-1) {
1184 if ((error = copyinstr(envp, args->endp,
1185 args->stringspace, &length))) {
1186 if (error == ENAMETOOLONG)
1190 args->stringspace -= length;
1191 args->endp += length;
1199 exec_free_args(args);
1204 * Allocate temporary demand-paged, zero-filled memory for the file name,
1205 * argument, and environment strings. Returns zero if the allocation succeeds
1206 * and ENOMEM otherwise.
1209 exec_alloc_args(struct image_args *args)
1212 args->buf = (char *)kmap_alloc_wait(exec_map, PATH_MAX + ARG_MAX);
1213 return (args->buf != NULL ? 0 : ENOMEM);
1217 exec_free_args(struct image_args *args)
1220 if (args->buf != NULL) {
1221 kmap_free_wakeup(exec_map, (vm_offset_t)args->buf,
1222 PATH_MAX + ARG_MAX);
1225 if (args->fname_buf != NULL) {
1226 free(args->fname_buf, M_TEMP);
1227 args->fname_buf = NULL;
1232 * Copy strings out to the new process address space, constructing new arg
1233 * and env vector tables. Return a pointer to the base so that it can be used
1234 * as the initial stack pointer.
1237 exec_copyout_strings(imgp)
1238 struct image_params *imgp;
1244 register_t *stack_base;
1245 struct ps_strings *arginfo;
1247 size_t execpath_len;
1248 int szsigcode, szps;
1249 char canary[sizeof(long) * 8];
1251 szps = sizeof(pagesizes[0]) * MAXPAGESIZES;
1253 * Calculate string base and vector table pointers.
1254 * Also deal with signal trampoline code for this exec type.
1256 if (imgp->execpath != NULL && imgp->auxargs != NULL)
1257 execpath_len = strlen(imgp->execpath) + 1;
1262 arginfo = (struct ps_strings *)p->p_sysent->sv_psstrings;
1263 if (p->p_sysent->sv_sigcode_base == 0) {
1264 if (p->p_sysent->sv_szsigcode != NULL)
1265 szsigcode = *(p->p_sysent->sv_szsigcode);
1267 destp = (uintptr_t)arginfo;
1272 if (szsigcode != 0) {
1274 destp = rounddown2(destp, sizeof(void *));
1275 copyout(p->p_sysent->sv_sigcode, (void *)destp, szsigcode);
1279 * Copy the image path for the rtld.
1281 if (execpath_len != 0) {
1282 destp -= execpath_len;
1283 imgp->execpathp = destp;
1284 copyout(imgp->execpath, (void *)destp, execpath_len);
1288 * Prepare the canary for SSP.
1290 arc4rand(canary, sizeof(canary), 0);
1291 destp -= sizeof(canary);
1292 imgp->canary = destp;
1293 copyout(canary, (void *)destp, sizeof(canary));
1294 imgp->canarylen = sizeof(canary);
1297 * Prepare the pagesizes array.
1300 destp = rounddown2(destp, sizeof(void *));
1301 imgp->pagesizes = destp;
1302 copyout(pagesizes, (void *)destp, szps);
1303 imgp->pagesizeslen = szps;
1305 destp -= ARG_MAX - imgp->args->stringspace;
1306 destp = rounddown2(destp, sizeof(void *));
1309 * If we have a valid auxargs ptr, prepare some room
1312 if (imgp->auxargs) {
1314 * 'AT_COUNT*2' is size for the ELF Auxargs data. This is for
1315 * lower compatibility.
1317 imgp->auxarg_size = (imgp->auxarg_size) ? imgp->auxarg_size :
1320 * The '+ 2' is for the null pointers at the end of each of
1321 * the arg and env vector sets,and imgp->auxarg_size is room
1322 * for argument of Runtime loader.
1324 vectp = (char **)(destp - (imgp->args->argc +
1325 imgp->args->envc + 2 + imgp->auxarg_size)
1329 * The '+ 2' is for the null pointers at the end of each of
1330 * the arg and env vector sets
1332 vectp = (char **)(destp - (imgp->args->argc + imgp->args->envc
1333 + 2) * sizeof(char *));
1337 * vectp also becomes our initial stack base
1339 stack_base = (register_t *)vectp;
1341 stringp = imgp->args->begin_argv;
1342 argc = imgp->args->argc;
1343 envc = imgp->args->envc;
1346 * Copy out strings - arguments and environment.
1348 copyout(stringp, (void *)destp, ARG_MAX - imgp->args->stringspace);
1351 * Fill in "ps_strings" struct for ps, w, etc.
1353 suword(&arginfo->ps_argvstr, (long)(intptr_t)vectp);
1354 suword32(&arginfo->ps_nargvstr, argc);
1357 * Fill in argument portion of vector table.
1359 for (; argc > 0; --argc) {
1360 suword(vectp++, (long)(intptr_t)destp);
1361 while (*stringp++ != 0)
1366 /* a null vector table pointer separates the argp's from the envp's */
1369 suword(&arginfo->ps_envstr, (long)(intptr_t)vectp);
1370 suword32(&arginfo->ps_nenvstr, envc);
1373 * Fill in environment portion of vector table.
1375 for (; envc > 0; --envc) {
1376 suword(vectp++, (long)(intptr_t)destp);
1377 while (*stringp++ != 0)
1382 /* end of vector table is a null pointer */
1385 return (stack_base);
1389 * Check permissions of file to execute.
1390 * Called with imgp->vp locked.
1391 * Return 0 for success or error code on failure.
1394 exec_check_permissions(imgp)
1395 struct image_params *imgp;
1397 struct vnode *vp = imgp->vp;
1398 struct vattr *attr = imgp->attr;
1400 int error, writecount;
1404 /* Get file attributes */
1405 error = VOP_GETATTR(vp, attr, td->td_ucred);
1410 error = mac_vnode_check_exec(td->td_ucred, imgp->vp, imgp);
1416 * 1) Check if file execution is disabled for the filesystem that
1417 * this file resides on.
1418 * 2) Ensure that at least one execute bit is on. Otherwise, a
1419 * privileged user will always succeed, and we don't want this
1420 * to happen unless the file really is executable.
1421 * 3) Ensure that the file is a regular file.
1423 if ((vp->v_mount->mnt_flag & MNT_NOEXEC) ||
1424 (attr->va_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) == 0 ||
1425 (attr->va_type != VREG))
1429 * Zero length files can't be exec'd
1431 if (attr->va_size == 0)
1435 * Check for execute permission to file based on current credentials.
1437 error = VOP_ACCESS(vp, VEXEC, td->td_ucred, td);
1442 * Check number of open-for-writes on the file and deny execution
1445 error = VOP_GET_WRITECOUNT(vp, &writecount);
1448 if (writecount != 0)
1452 * Call filesystem specific open routine (which does nothing in the
1455 error = VOP_OPEN(vp, FREAD, td->td_ucred, td, NULL);
1462 * Exec handler registration
1465 exec_register(execsw_arg)
1466 const struct execsw *execsw_arg;
1468 const struct execsw **es, **xs, **newexecsw;
1469 int count = 2; /* New slot and trailing NULL */
1472 for (es = execsw; *es; es++)
1474 newexecsw = malloc(count * sizeof(*es), M_TEMP, M_WAITOK);
1475 if (newexecsw == NULL)
1479 for (es = execsw; *es; es++)
1484 free(execsw, M_TEMP);
1490 exec_unregister(execsw_arg)
1491 const struct execsw *execsw_arg;
1493 const struct execsw **es, **xs, **newexecsw;
1497 panic("unregister with no handlers left?\n");
1499 for (es = execsw; *es; es++) {
1500 if (*es == execsw_arg)
1505 for (es = execsw; *es; es++)
1506 if (*es != execsw_arg)
1508 newexecsw = malloc(count * sizeof(*es), M_TEMP, M_WAITOK);
1509 if (newexecsw == NULL)
1512 for (es = execsw; *es; es++)
1513 if (*es != execsw_arg)
1517 free(execsw, M_TEMP);