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
26 * $FreeBSD: src/sys/kern/kern_exec.c,v 1.107.2.15 2002/07/30 15:40:46 nectar Exp $
27 * $DragonFly: src/sys/kern/kern_exec.c,v 1.58 2007/06/29 21:54:08 dillon Exp $
30 #include <sys/param.h>
31 #include <sys/systm.h>
32 #include <sys/sysproto.h>
33 #include <sys/kernel.h>
34 #include <sys/mount.h>
35 #include <sys/filedesc.h>
36 #include <sys/fcntl.h>
39 #include <sys/imgact.h>
40 #include <sys/imgact_elf.h>
41 #include <sys/kern_syscall.h>
43 #include <sys/malloc.h>
45 #include <sys/ktrace.h>
46 #include <sys/signalvar.h>
47 #include <sys/pioctl.h>
48 #include <sys/nlookup.h>
49 #include <sys/sfbuf.h>
50 #include <sys/sysent.h>
52 #include <sys/sysctl.h>
53 #include <sys/vnode.h>
54 #include <sys/vmmeter.h>
56 #include <sys/libkern.h>
59 #include <vm/vm_param.h>
62 #include <vm/vm_page.h>
63 #include <vm/vm_map.h>
64 #include <vm/vm_kern.h>
65 #include <vm/vm_extern.h>
66 #include <vm/vm_object.h>
67 #include <vm/vm_pager.h>
72 #include <sys/thread2.h>
74 MALLOC_DEFINE(M_PARGS, "proc-args", "Process arguments");
75 MALLOC_DEFINE(M_EXECARGS, "exec-args", "Exec arguments");
77 static register_t *exec_copyout_strings (struct image_params *);
79 /* XXX This should be vm_size_t. */
80 static u_long ps_strings = PS_STRINGS;
81 SYSCTL_ULONG(_kern, KERN_PS_STRINGS, ps_strings, CTLFLAG_RD, &ps_strings, 0, "");
83 /* XXX This should be vm_size_t. */
84 static u_long usrstack = USRSTACK;
85 SYSCTL_ULONG(_kern, KERN_USRSTACK, usrstack, CTLFLAG_RD, &usrstack, 0, "");
87 u_long ps_arg_cache_limit = PAGE_SIZE / 16;
88 SYSCTL_LONG(_kern, OID_AUTO, ps_arg_cache_limit, CTLFLAG_RW,
89 &ps_arg_cache_limit, 0, "");
92 SYSCTL_INT(_kern, OID_AUTO, ps_argsopen, CTLFLAG_RW, &ps_argsopen, 0, "");
94 void print_execve_args(struct image_args *args);
95 int debug_execve_args = 0;
96 SYSCTL_INT(_kern, OID_AUTO, debug_execve_args, CTLFLAG_RW, &debug_execve_args,
100 * Exec arguments object cache
102 static struct objcache *exec_objcache;
106 exec_objcache_init(void *arg __unused)
108 exec_objcache = objcache_create_mbacked(
109 M_EXECARGS, PATH_MAX + ARG_MAX,
110 16, /* up to this many objects */
111 2, /* minimal magazine capacity */
114 SYSINIT(exec_objcache, SI_BOOT2_MACHDEP, SI_ORDER_ANY, exec_objcache_init, 0);
117 * stackgap_random specifies if the stackgap should have a random size added
118 * to it. It must be a power of 2. If non-zero, the stack gap will be
119 * calculated as: ALIGN(karc4random() & (stackgap_random - 1)).
121 static int stackgap_random = 1024;
123 sysctl_kern_stackgap(SYSCTL_HANDLER_ARGS)
126 new_val = stackgap_random;
127 error = sysctl_handle_int(oidp, &new_val, 0, req);
128 if (error != 0 || req->newptr == NULL)
130 if ((new_val < 0) || (new_val > 16 * PAGE_SIZE) || ! powerof2(new_val))
132 stackgap_random = new_val;
137 SYSCTL_PROC(_kern, OID_AUTO, stackgap_random, CTLFLAG_RW|CTLTYPE_UINT,
138 0, 0, sysctl_kern_stackgap, "IU", "Max random stack gap (power of 2)");
141 print_execve_args(struct image_args *args)
146 cp = args->begin_argv;
147 for (ndx = 0; ndx < args->argc; ndx++) {
148 kprintf("\targv[%d]: %s\n", ndx, cp);
149 while (*cp++ != '\0');
151 for (ndx = 0; ndx < args->envc; ndx++) {
152 kprintf("\tenvv[%d]: %s\n", ndx, cp);
153 while (*cp++ != '\0');
158 * Each of the items is a pointer to a `const struct execsw', hence the
159 * double pointer here.
161 static const struct execsw **execsw;
164 kern_execve(struct nlookupdata *nd, struct image_args *args)
166 struct thread *td = curthread;
167 struct lwp *lp = td->td_lwp;
168 struct proc *p = td->td_proc;
169 register_t *stack_base;
171 struct image_params image_params, *imgp;
173 int (*img_first) (struct image_params *);
175 if (p->p_nthreads != 1) {
176 kprintf("pid %d attempt to exec with multiple LWPs present\n",
181 if (debug_execve_args) {
182 kprintf("%s()\n", __func__);
183 print_execve_args(args);
187 imgp = &image_params;
190 * Lock the process and set the P_INEXEC flag to indicate that
191 * it should be left alone until we're done here. This is
192 * necessary to avoid race conditions - e.g. in ptrace() -
193 * that might allow a local user to illicitly obtain elevated
196 p->p_flag |= P_INEXEC;
199 * Initialize part of the common data
204 imgp->entry_addr = 0;
206 imgp->vmspace_destroyed = 0;
207 imgp->interpreted = 0;
208 imgp->interpreter_name[0] = 0;
209 imgp->auxargs = NULL;
211 imgp->firstpage = NULL;
212 imgp->ps_strings = 0;
213 imgp->image_header = NULL;
218 * Translate the file name to a vnode. Unlock the cache entry to
219 * improve parallelism for programs exec'd in parallel.
221 if ((error = nlookup(nd)) != 0)
223 error = cache_vget(&nd->nl_nch, nd->nl_cred, LK_EXCLUSIVE, &imgp->vp);
224 KKASSERT(nd->nl_flags & NLC_NCPISLOCKED);
225 nd->nl_flags &= ~NLC_NCPISLOCKED;
226 cache_unlock(&nd->nl_nch);
231 * Check file permissions (also 'opens' file)
233 error = exec_check_permissions(imgp);
236 goto exec_fail_dealloc;
239 error = exec_map_first_page(imgp);
242 goto exec_fail_dealloc;
244 if (debug_execve_args && imgp->interpreted) {
245 kprintf(" target is interpreted -- recursive pass\n");
246 kprintf(" interpreter: %s\n", imgp->interpreter_name);
247 print_execve_args(args);
251 * If the current process has a special image activator it
252 * wants to try first, call it. For example, emulating shell
253 * scripts differently.
256 if ((img_first = imgp->proc->p_sysent->sv_imgact_try) != NULL)
257 error = img_first(imgp);
260 * If the vnode has a registered vmspace, exec the vmspace
262 if (error == -1 && imgp->vp->v_resident) {
263 error = exec_resident_imgact(imgp);
267 * Loop through the list of image activators, calling each one.
268 * An activator returns -1 if there is no match, 0 on success,
269 * and an error otherwise.
271 for (i = 0; error == -1 && execsw[i]; ++i) {
272 if (execsw[i]->ex_imgact == NULL ||
273 execsw[i]->ex_imgact == img_first) {
276 error = (*execsw[i]->ex_imgact)(imgp);
282 goto exec_fail_dealloc;
286 * Special interpreter operation, cleanup and loop up to try to
287 * activate the interpreter.
289 if (imgp->interpreted) {
290 exec_unmap_first_page(imgp);
294 error = nlookup_init(nd, imgp->interpreter_name, UIO_SYSSPACE,
302 * Copy out strings (args and env) and initialize stack base
304 stack_base = exec_copyout_strings(imgp);
305 p->p_vmspace->vm_minsaddr = (char *)stack_base;
308 * If custom stack fixup routine present for this process
309 * let it do the stack setup. If we are running a resident
310 * image there is no auxinfo or other image activator context
311 * so don't try to add fixups to the stack.
313 * Else stuff argument count as first item on stack
315 if (p->p_sysent->sv_fixup && imgp->resident == 0)
316 (*p->p_sysent->sv_fixup)(&stack_base, imgp);
318 suword(--stack_base, imgp->args->argc);
321 * For security and other reasons, the file descriptor table cannot
322 * be shared after an exec.
324 if (p->p_fd->fd_refcnt > 1) {
325 struct filedesc *tmp;
333 * For security and other reasons, signal handlers cannot
334 * be shared after an exec. The new proces gets a copy of the old
335 * handlers. In execsigs(), the new process will have its signals
338 if (p->p_sigacts->ps_refcnt > 1) {
339 struct sigacts *newsigacts;
341 newsigacts = (struct sigacts *)kmalloc(sizeof(*newsigacts),
342 M_SUBPROC, M_WAITOK);
343 bcopy(p->p_sigacts, newsigacts, sizeof(*newsigacts));
344 p->p_sigacts->ps_refcnt--;
345 p->p_sigacts = newsigacts;
346 p->p_sigacts->ps_refcnt = 1;
350 * For security and other reasons virtual kernels cannot be
351 * inherited by an exec. This also allows a virtual kernel
352 * to fork/exec unrelated applications.
360 /* close files on exec */
363 /* reset caught signals */
366 /* name this process - nameiexec(p, ndp) */
367 len = min(nd->nl_nch.ncp->nc_nlen, MAXCOMLEN);
368 bcopy(nd->nl_nch.ncp->nc_name, p->p_comm, len);
370 bcopy(p->p_comm, lp->lwp_thread->td_comm, MAXCOMLEN+1);
373 * mark as execed, wakeup the process that vforked (if any) and tell
374 * it that it now has its own resources back
377 if (p->p_pptr && (p->p_flag & P_PPWAIT)) {
378 p->p_flag &= ~P_PPWAIT;
379 wakeup((caddr_t)p->p_pptr);
383 * Implement image setuid/setgid.
385 * Don't honor setuid/setgid if the filesystem prohibits it or if
386 * the process is being traced.
388 if ((((attr.va_mode & VSUID) && p->p_ucred->cr_uid != attr.va_uid) ||
389 ((attr.va_mode & VSGID) && p->p_ucred->cr_gid != attr.va_gid)) &&
390 (imgp->vp->v_mount->mnt_flag & MNT_NOSUID) == 0 &&
391 (p->p_flag & P_TRACED) == 0) {
393 * Turn off syscall tracing for set-id programs, except for
394 * root. Record any set-id flags first to make sure that
395 * we do not regain any tracing during a possible block.
398 if (p->p_tracenode && suser(td) != 0) {
399 ktrdestroy(&p->p_tracenode);
402 /* Close any file descriptors 0..2 that reference procfs */
404 /* Make sure file descriptors 0..2 are in use. */
405 error = fdcheckstd(p);
407 goto exec_fail_dealloc;
409 * Set the new credentials.
412 if (attr.va_mode & VSUID)
413 change_euid(attr.va_uid);
414 if (attr.va_mode & VSGID)
415 p->p_ucred->cr_gid = attr.va_gid;
418 * Clear local varsym variables
420 varsymset_clean(&p->p_varsymset);
422 if (p->p_ucred->cr_uid == p->p_ucred->cr_ruid &&
423 p->p_ucred->cr_gid == p->p_ucred->cr_rgid)
424 p->p_flag &= ~P_SUGID;
428 * Implement correct POSIX saved-id behavior.
430 if (p->p_ucred->cr_svuid != p->p_ucred->cr_uid ||
431 p->p_ucred->cr_svgid != p->p_ucred->cr_gid) {
433 p->p_ucred->cr_svuid = p->p_ucred->cr_uid;
434 p->p_ucred->cr_svgid = p->p_ucred->cr_gid;
438 * Store the vp for use in procfs
440 if (p->p_textvp) /* release old reference */
442 p->p_textvp = imgp->vp;
446 * Notify others that we exec'd, and clear the P_INEXEC flag
447 * as we're now a bona fide freshly-execed process.
449 KNOTE(&p->p_klist, NOTE_EXEC);
450 p->p_flag &= ~P_INEXEC;
453 * If tracing the process, trap to debugger so breakpoints
454 * can be set before the program executes.
456 STOPEVENT(p, S_EXEC, 0);
458 if (p->p_flag & P_TRACED)
461 /* clear "fork but no exec" flag, as we _are_ execing */
462 p->p_acflag &= ~AFORK;
464 /* Set values passed into the program in registers. */
465 exec_setregs(imgp->entry_addr, (u_long)(uintptr_t)stack_base,
468 /* Free any previous argument cache */
469 if (p->p_args && --p->p_args->ar_ref == 0)
470 FREE(p->p_args, M_PARGS);
473 /* Cache arguments if they fit inside our allowance */
474 i = imgp->args->begin_envv - imgp->args->begin_argv;
475 if (ps_arg_cache_limit >= i + sizeof(struct pargs)) {
476 MALLOC(p->p_args, struct pargs *, sizeof(struct pargs) + i,
478 p->p_args->ar_ref = 1;
479 p->p_args->ar_length = i;
480 bcopy(imgp->args->begin_argv, p->p_args->ar_args, i);
486 * free various allocated resources
489 exec_unmap_first_page(imgp);
497 ++mycpu->gd_cnt.v_exec;
502 /* we're done here, clear P_INEXEC */
503 p->p_flag &= ~P_INEXEC;
504 if (imgp->vmspace_destroyed) {
505 /* sorry, no more process anymore. exit gracefully */
506 exit1(W_EXITCODE(0, SIGABRT));
515 * execve() system call.
518 sys_execve(struct execve_args *uap)
520 struct nlookupdata nd;
521 struct image_args args;
524 error = nlookup_init(&nd, uap->fname, UIO_USERSPACE, NLC_FOLLOW);
526 error = exec_copyin_args(&args, uap->fname, PATH_USERSPACE,
527 uap->argv, uap->envv);
530 error = kern_execve(&nd, &args);
532 exec_free_args(&args);
535 * The syscall result is returned in registers to the new program.
536 * Linux will register %edx as an atexit function and we must be
537 * sure to set it to 0. XXX
540 uap->sysmsg_result64 = 0;
546 exec_map_first_page(struct image_params *imgp)
550 vm_page_t ma[VM_INITIAL_PAGEIN];
555 exec_unmap_first_page(imgp);
558 * The file has to be mappable.
560 if ((object = imgp->vp->v_object) == NULL)
564 * We shouldn't need protection for vm_page_grab() but we certainly
565 * need it for the lookup loop below (lookup/busy race), since
566 * an interrupt can unbusy and free the page before our busy check.
569 m = vm_page_grab(object, 0, VM_ALLOC_NORMAL | VM_ALLOC_RETRY);
571 if ((m->valid & VM_PAGE_BITS_ALL) != VM_PAGE_BITS_ALL) {
573 initial_pagein = VM_INITIAL_PAGEIN;
574 if (initial_pagein > object->size)
575 initial_pagein = object->size;
576 for (i = 1; i < initial_pagein; i++) {
577 if ((m = vm_page_lookup(object, i)) != NULL) {
578 if ((m->flags & PG_BUSY) || m->busy)
584 m = vm_page_alloc(object, i, VM_ALLOC_NORMAL);
593 * get_pages unbusies all the requested pages except the
594 * primary page (at index 0 in this case).
596 rv = vm_pager_get_pages(object, ma, initial_pagein, 0);
597 m = vm_page_lookup(object, 0);
599 if (rv != VM_PAGER_OK || m == NULL || m->valid == 0) {
601 vm_page_protect(m, VM_PROT_NONE);
609 vm_page_wakeup(m); /* unbusy the page */
612 imgp->firstpage = sf_buf_alloc(m, SFB_CPUPRIVATE);
613 imgp->image_header = (void *)sf_buf_kva(imgp->firstpage);
619 exec_unmap_first_page(struct image_params *imgp)
624 if (imgp->firstpage != NULL) {
625 m = sf_buf_page(imgp->firstpage);
626 sf_buf_free(imgp->firstpage);
627 imgp->firstpage = NULL;
628 imgp->image_header = NULL;
635 * Destroy old address space, and allocate a new stack
636 * The new stack is only SGROWSIZ large because it is grown
637 * automatically in trap.c.
640 exec_new_vmspace(struct image_params *imgp, struct vmspace *vmcopy)
643 struct vmspace *vmspace = imgp->proc->p_vmspace;
644 vm_offset_t stack_addr = USRSTACK - maxssiz;
647 imgp->vmspace_destroyed = 1;
649 if (curthread->td_proc->p_nthreads > 1)
650 killlwps(curthread->td_lwp);
653 * Prevent a pending AIO from modifying the new address space.
655 aio_proc_rundown(imgp->proc);
658 * Blow away entire process VM, if address space not shared,
659 * otherwise, create a new VM space so that other threads are
660 * not disrupted. If we are execing a resident vmspace we
661 * create a duplicate of it and remap the stack.
663 * The exitingcnt test is not strictly necessary but has been
664 * included for code sanity (to make the code more deterministic).
666 map = &vmspace->vm_map;
668 vmspace_exec(imgp->proc, vmcopy);
669 vmspace = imgp->proc->p_vmspace;
670 pmap_remove_pages(vmspace_pmap(vmspace), stack_addr, USRSTACK);
671 map = &vmspace->vm_map;
672 } else if (vmspace->vm_sysref.refcnt == 1 &&
673 vmspace->vm_exitingcnt == 0) {
675 if (vmspace->vm_upcalls)
676 upc_release(vmspace, ONLY_LWP_IN_PROC(imgp->proc));
677 pmap_remove_pages(vmspace_pmap(vmspace),
678 0, VM_MAX_USER_ADDRESS);
679 vm_map_remove(map, 0, VM_MAX_USER_ADDRESS);
681 vmspace_exec(imgp->proc, NULL);
682 vmspace = imgp->proc->p_vmspace;
683 map = &vmspace->vm_map;
686 /* Allocate a new stack */
687 error = vm_map_stack(&vmspace->vm_map, stack_addr, (vm_size_t)maxssiz,
688 VM_PROT_ALL, VM_PROT_ALL, 0);
692 /* vm_ssize and vm_maxsaddr are somewhat antiquated concepts in the
693 * VM_STACK case, but they are still used to monitor the size of the
694 * process stack so we can check the stack rlimit.
696 vmspace->vm_ssize = sgrowsiz >> PAGE_SHIFT;
697 vmspace->vm_maxsaddr = (char *)USRSTACK - maxssiz;
703 * Copy out argument and environment strings from the old process
704 * address space into the temporary string buffer.
707 exec_copyin_args(struct image_args *args, char *fname,
708 enum exec_path_segflg segflg, char **argv, char **envv)
714 bzero(args, sizeof(*args));
716 args->buf = objcache_get(exec_objcache, M_WAITOK);
717 if (args->buf == NULL)
719 args->begin_argv = args->buf;
720 args->endp = args->begin_argv;
721 args->space = ARG_MAX;
723 args->fname = args->buf + ARG_MAX;
726 * Copy the file name.
728 if (segflg == PATH_SYSSPACE) {
729 error = copystr(fname, args->fname, PATH_MAX, &length);
730 } else if (segflg == PATH_USERSPACE) {
731 error = copyinstr(fname, args->fname, PATH_MAX, &length);
735 * Extract argument strings. argv may not be NULL. The argv
736 * array is terminated by a NULL entry. We special-case the
737 * situation where argv[0] is NULL by passing { filename, NULL }
738 * to the new program to guarentee that the interpreter knows what
739 * file to open in case we exec an interpreted file. Note that
740 * a NULL argv[0] terminates the argv[] array.
742 * XXX the special-casing of argv[0] is historical and needs to be
748 while ((argp = (caddr_t)(intptr_t)fuword(argv++)) != NULL) {
749 if (argp == (caddr_t)-1) {
753 error = copyinstr(argp, args->endp,
754 args->space, &length);
756 if (error == ENAMETOOLONG)
760 args->space -= length;
761 args->endp += length;
764 if (args->argc == 0 && error == 0) {
765 length = strlen(args->fname) + 1;
766 if (length > args->space) {
769 bcopy(args->fname, args->endp, length);
770 args->space -= length;
771 args->endp += length;
777 args->begin_envv = args->endp;
780 * extract environment strings. envv may be NULL.
782 if (envv && error == 0) {
783 while ((envp = (caddr_t) (intptr_t) fuword(envv++))) {
784 if (envp == (caddr_t) -1) {
788 error = copyinstr(envp, args->endp, args->space,
791 if (error == ENAMETOOLONG)
795 args->space -= length;
796 args->endp += length;
804 exec_free_args(struct image_args *args)
807 objcache_put(exec_objcache, args->buf);
813 * Copy strings out to the new process address space, constructing
814 * new arg and env vector tables. Return a pointer to the base
815 * so that it can be used as the initial stack pointer.
818 exec_copyout_strings(struct image_params *imgp)
820 int argc, envc, sgap;
822 char *stringp, *destp;
823 register_t *stack_base;
824 struct ps_strings *arginfo;
828 * Calculate string base and vector table pointers.
829 * Also deal with signal trampoline code for this exec type.
831 arginfo = (struct ps_strings *)PS_STRINGS;
832 szsigcode = *(imgp->proc->p_sysent->sv_szsigcode);
833 if (stackgap_random != 0)
834 sgap = ALIGN(karc4random() & (stackgap_random - 1));
837 destp = (caddr_t)arginfo - szsigcode - SPARE_USRSPACE - sgap -
838 roundup((ARG_MAX - imgp->args->space), sizeof(char *));
844 copyout(imgp->proc->p_sysent->sv_sigcode,
845 ((caddr_t)arginfo - szsigcode), szsigcode);
848 * If we have a valid auxargs ptr, prepare some room
851 * The '+ 2' is for the null pointers at the end of each of the
852 * arg and env vector sets, and 'AT_COUNT*2' is room for the
856 vectp = (char **)(destp - (imgp->args->argc +
857 imgp->args->envc + 2 + AT_COUNT * 2) * sizeof(char*));
859 vectp = (char **)(destp - (imgp->args->argc +
860 imgp->args->envc + 2) * sizeof(char*));
864 * NOTE: don't bother aligning the stack here for GCC 2.x, it will
865 * be done in crt1.o. Note that GCC 3.x aligns the stack in main.
869 * vectp also becomes our initial stack base
871 stack_base = (register_t *)vectp;
873 stringp = imgp->args->begin_argv;
874 argc = imgp->args->argc;
875 envc = imgp->args->envc;
878 * Copy out strings - arguments and environment.
880 copyout(stringp, destp, ARG_MAX - imgp->args->space);
883 * Fill in "ps_strings" struct for ps, w, etc.
885 suword(&arginfo->ps_argvstr, (long)(intptr_t)vectp);
886 suword(&arginfo->ps_nargvstr, argc);
889 * Fill in argument portion of vector table.
891 for (; argc > 0; --argc) {
892 suword(vectp++, (long)(intptr_t)destp);
893 while (*stringp++ != 0)
898 /* a null vector table pointer separates the argp's from the envp's */
901 suword(&arginfo->ps_envstr, (long)(intptr_t)vectp);
902 suword(&arginfo->ps_nenvstr, envc);
905 * Fill in environment portion of vector table.
907 for (; envc > 0; --envc) {
908 suword(vectp++, (long)(intptr_t)destp);
909 while (*stringp++ != 0)
914 /* end of vector table is a null pointer */
921 * Check permissions of file to execute.
922 * Return 0 for success or error code on failure.
925 exec_check_permissions(struct image_params *imgp)
927 struct proc *p = imgp->proc;
928 struct vnode *vp = imgp->vp;
929 struct vattr *attr = imgp->attr;
932 /* Get file attributes */
933 error = VOP_GETATTR(vp, attr);
938 * 1) Check if file execution is disabled for the filesystem that this
940 * 2) Insure that at least one execute bit is on - otherwise root
941 * will always succeed, and we don't want to happen unless the
942 * file really is executable.
943 * 3) Insure that the file is a regular file.
945 if ((vp->v_mount->mnt_flag & MNT_NOEXEC) ||
946 ((attr->va_mode & 0111) == 0) ||
947 (attr->va_type != VREG)) {
952 * Zero length files can't be exec'd
954 if (attr->va_size == 0)
958 * Check for execute permission to file based on current credentials.
960 error = VOP_ACCESS(vp, VEXEC, p->p_ucred);
965 * Check number of open-for-writes on the file and deny execution
968 if (vp->v_writecount)
972 * Call filesystem specific open routine, which allows us to read,
973 * write, and mmap the file. Without the VOP_OPEN we can only
976 error = VOP_OPEN(vp, FREAD, p->p_ucred, NULL);
984 * Exec handler registration
987 exec_register(const struct execsw *execsw_arg)
989 const struct execsw **es, **xs, **newexecsw;
990 int count = 2; /* New slot and trailing NULL */
993 for (es = execsw; *es; es++)
995 newexecsw = kmalloc(count * sizeof(*es), M_TEMP, M_WAITOK);
996 if (newexecsw == NULL)
1000 for (es = execsw; *es; es++)
1005 kfree(execsw, M_TEMP);
1011 exec_unregister(const struct execsw *execsw_arg)
1013 const struct execsw **es, **xs, **newexecsw;
1017 panic("unregister with no handlers left?");
1019 for (es = execsw; *es; es++) {
1020 if (*es == execsw_arg)
1025 for (es = execsw; *es; es++)
1026 if (*es != execsw_arg)
1028 newexecsw = kmalloc(count * sizeof(*es), M_TEMP, M_WAITOK);
1029 if (newexecsw == NULL)
1032 for (es = execsw; *es; es++)
1033 if (*es != execsw_arg)
1037 kfree(execsw, M_TEMP);