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 1.28 2004/10/12 19:20:46 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/signalvar.h>
46 #include <sys/pioctl.h>
47 #include <sys/namei.h>
48 #include <sys/sfbuf.h>
49 #include <sys/sysent.h>
51 #include <sys/sysctl.h>
52 #include <sys/vnode.h>
53 #include <sys/vmmeter.h>
57 #include <vm/vm_param.h>
60 #include <vm/vm_page.h>
61 #include <vm/vm_map.h>
62 #include <vm/vm_kern.h>
63 #include <vm/vm_extern.h>
64 #include <vm/vm_object.h>
65 #include <vm/vm_pager.h>
68 #include <machine/reg.h>
70 #include <sys/thread2.h>
72 MALLOC_DEFINE(M_PARGS, "proc-args", "Process arguments");
74 static register_t *exec_copyout_strings (struct image_params *);
76 /* XXX This should be vm_size_t. */
77 static u_long ps_strings = PS_STRINGS;
78 SYSCTL_ULONG(_kern, KERN_PS_STRINGS, ps_strings, CTLFLAG_RD, &ps_strings, 0, "");
80 /* XXX This should be vm_size_t. */
81 static u_long usrstack = USRSTACK;
82 SYSCTL_ULONG(_kern, KERN_USRSTACK, usrstack, CTLFLAG_RD, &usrstack, 0, "");
84 u_long ps_arg_cache_limit = PAGE_SIZE / 16;
85 SYSCTL_LONG(_kern, OID_AUTO, ps_arg_cache_limit, CTLFLAG_RW,
86 &ps_arg_cache_limit, 0, "");
89 SYSCTL_INT(_kern, OID_AUTO, ps_argsopen, CTLFLAG_RW, &ps_argsopen, 0, "");
91 void print_execve_args(struct image_args *args);
92 int debug_execve_args = 0;
93 SYSCTL_INT(_kern, OID_AUTO, debug_execve_args, CTLFLAG_RW, &debug_execve_args,
97 print_execve_args(struct image_args *args)
102 cp = args->begin_argv;
103 for (ndx = 0; ndx < args->argc; ndx++) {
104 printf("\targv[%d]: %s\n", ndx, cp);
105 while (*cp++ != '\0');
107 for (ndx = 0; ndx < args->envc; ndx++) {
108 printf("\tenvv[%d]: %s\n", ndx, cp);
109 while (*cp++ != '\0');
114 * Each of the items is a pointer to a `const struct execsw', hence the
115 * double pointer here.
117 static const struct execsw **execsw;
120 kern_execve(struct nameidata *ndp, struct image_args *args)
122 struct thread *td = curthread;
123 struct proc *p = td->td_proc;
124 register_t *stack_base;
126 struct image_params image_params, *imgp;
128 int (*img_first) (struct image_params *);
130 if (debug_execve_args) {
131 printf("%s()\n", __func__);
132 print_execve_args(args);
136 imgp = &image_params;
139 * Lock the process and set the P_INEXEC flag to indicate that
140 * it should be left alone until we're done here. This is
141 * necessary to avoid race conditions - e.g. in ptrace() -
142 * that might allow a local user to illicitly obtain elevated
145 p->p_flag |= P_INEXEC;
148 * Initialize part of the common data
153 imgp->entry_addr = 0;
155 imgp->vmspace_destroyed = 0;
156 imgp->interpreted = 0;
157 imgp->interpreter_name[0] = 0;
158 imgp->auxargs = NULL;
160 imgp->firstpage = NULL;
161 imgp->ps_strings = 0;
162 imgp->image_header = NULL;
167 * Translate the file name. namei() returns a vnode pointer
168 * in ni_vp amoung other things.
170 if ((error = namei(ndp)) != 0)
173 imgp->vp = ndp->ni_vp;
176 * Check file permissions (also 'opens' file)
178 error = exec_check_permissions(imgp);
180 VOP_UNLOCK(imgp->vp, 0, td);
181 goto exec_fail_dealloc;
184 error = exec_map_first_page(imgp);
185 VOP_UNLOCK(imgp->vp, 0, td);
187 goto exec_fail_dealloc;
189 if (debug_execve_args && imgp->interpreted) {
190 printf(" target is interpreted -- recursive pass\n");
191 printf(" interpreter: %s\n", imgp->interpreter_name);
192 print_execve_args(args);
196 * If the current process has a special image activator it
197 * wants to try first, call it. For example, emulating shell
198 * scripts differently.
201 if ((img_first = imgp->proc->p_sysent->sv_imgact_try) != NULL)
202 error = img_first(imgp);
205 * If the vnode has a registered vmspace, exec the vmspace
207 if (error == -1 && imgp->vp->v_resident) {
208 error = exec_resident_imgact(imgp);
212 * Loop through the list of image activators, calling each one.
213 * An activator returns -1 if there is no match, 0 on success,
214 * and an error otherwise.
216 for (i = 0; error == -1 && execsw[i]; ++i) {
217 if (execsw[i]->ex_imgact == NULL ||
218 execsw[i]->ex_imgact == img_first) {
221 error = (*execsw[i]->ex_imgact)(imgp);
227 goto exec_fail_dealloc;
231 * Special interpreter operation, cleanup and loop up to try to
232 * activate the interpreter.
234 if (imgp->interpreted) {
235 exec_unmap_first_page(imgp);
236 /* free name buffer and old vnode */
237 NDFREE(ndp, NDF_ONLY_PNBUF);
239 /* set new name to that of the interpreter */
240 NDINIT(ndp, NAMEI_LOOKUP,
241 CNP_LOCKLEAF | CNP_FOLLOW | CNP_SAVENAME,
242 UIO_SYSSPACE, imgp->interpreter_name, td);
247 * Copy out strings (args and env) and initialize stack base
249 stack_base = exec_copyout_strings(imgp);
250 p->p_vmspace->vm_minsaddr = (char *)stack_base;
253 * If custom stack fixup routine present for this process
254 * let it do the stack setup. If we are running a resident
255 * image there is no auxinfo or other image activator context
256 * so don't try to add fixups to the stack.
258 * Else stuff argument count as first item on stack
260 if (p->p_sysent->sv_fixup && imgp->resident == 0)
261 (*p->p_sysent->sv_fixup)(&stack_base, imgp);
263 suword(--stack_base, imgp->args->argc);
266 * For security and other reasons, the file descriptor table cannot
267 * be shared after an exec.
269 if (p->p_fd->fd_refcnt > 1) {
270 struct filedesc *tmp;
278 * For security and other reasons, signal handlers cannot
279 * be shared after an exec. The new proces gets a copy of the old
280 * handlers. In execsigs(), the new process will have its signals
283 if (p->p_procsig->ps_refcnt > 1) {
284 struct procsig *newprocsig;
286 MALLOC(newprocsig, struct procsig *, sizeof(struct procsig),
287 M_SUBPROC, M_WAITOK);
288 bcopy(p->p_procsig, newprocsig, sizeof(*newprocsig));
289 p->p_procsig->ps_refcnt--;
290 p->p_procsig = newprocsig;
291 p->p_procsig->ps_refcnt = 1;
292 if (p->p_sigacts == &p->p_addr->u_sigacts)
293 panic("shared procsig but private sigacts?");
295 p->p_addr->u_sigacts = *p->p_sigacts;
296 p->p_sigacts = &p->p_addr->u_sigacts;
302 /* close files on exec */
305 /* reset caught signals */
308 /* name this process - nameiexec(p, ndp) */
309 len = min(ndp->ni_cnd.cn_namelen,MAXCOMLEN);
310 bcopy(ndp->ni_cnd.cn_nameptr, p->p_comm, len);
314 * mark as execed, wakeup the process that vforked (if any) and tell
315 * it that it now has its own resources back
318 if (p->p_pptr && (p->p_flag & P_PPWAIT)) {
319 p->p_flag &= ~P_PPWAIT;
320 wakeup((caddr_t)p->p_pptr);
324 * Implement image setuid/setgid.
326 * Don't honor setuid/setgid if the filesystem prohibits it or if
327 * the process is being traced.
329 if ((((attr.va_mode & VSUID) && p->p_ucred->cr_uid != attr.va_uid) ||
330 ((attr.va_mode & VSGID) && p->p_ucred->cr_gid != attr.va_gid)) &&
331 (imgp->vp->v_mount->mnt_flag & MNT_NOSUID) == 0 &&
332 (p->p_flag & P_TRACED) == 0) {
334 * Turn off syscall tracing for set-id programs, except for
335 * root. Record any set-id flags first to make sure that
336 * we do not regain any tracing during a possible block.
339 if (p->p_tracep && suser(td)) {
342 if ((vtmp = p->p_tracep) != NULL) {
348 /* Close any file descriptors 0..2 that reference procfs */
350 /* Make sure file descriptors 0..2 are in use. */
351 error = fdcheckstd(p);
353 goto exec_fail_dealloc;
355 * Set the new credentials.
358 if (attr.va_mode & VSUID)
359 change_euid(attr.va_uid);
360 if (attr.va_mode & VSGID)
361 p->p_ucred->cr_gid = attr.va_gid;
364 * Clear local varsym variables
366 varsymset_clean(&p->p_varsymset);
368 if (p->p_ucred->cr_uid == p->p_ucred->cr_ruid &&
369 p->p_ucred->cr_gid == p->p_ucred->cr_rgid)
370 p->p_flag &= ~P_SUGID;
374 * Implement correct POSIX saved-id behavior.
376 if (p->p_ucred->cr_svuid != p->p_ucred->cr_uid ||
377 p->p_ucred->cr_svgid != p->p_ucred->cr_gid) {
379 p->p_ucred->cr_svuid = p->p_ucred->cr_uid;
380 p->p_ucred->cr_svgid = p->p_ucred->cr_gid;
384 * Store the vp for use in procfs
386 if (p->p_textvp) /* release old reference */
389 p->p_textvp = ndp->ni_vp;
392 * Notify others that we exec'd, and clear the P_INEXEC flag
393 * as we're now a bona fide freshly-execed process.
395 KNOTE(&p->p_klist, NOTE_EXEC);
396 p->p_flag &= ~P_INEXEC;
399 * If tracing the process, trap to debugger so breakpoints
400 * can be set before the program executes.
402 STOPEVENT(p, S_EXEC, 0);
404 if (p->p_flag & P_TRACED)
407 /* clear "fork but no exec" flag, as we _are_ execing */
408 p->p_acflag &= ~AFORK;
410 /* Set values passed into the program in registers. */
411 setregs(p, imgp->entry_addr, (u_long)(uintptr_t)stack_base,
414 /* Free any previous argument cache */
415 if (p->p_args && --p->p_args->ar_ref == 0)
416 FREE(p->p_args, M_PARGS);
419 /* Cache arguments if they fit inside our allowance */
420 i = imgp->args->begin_envv - imgp->args->begin_argv;
421 if (ps_arg_cache_limit >= i + sizeof(struct pargs)) {
422 MALLOC(p->p_args, struct pargs *, sizeof(struct pargs) + i,
424 p->p_args->ar_ref = 1;
425 p->p_args->ar_length = i;
426 bcopy(imgp->args->begin_argv, p->p_args->ar_args, i);
432 * free various allocated resources
435 exec_unmap_first_page(imgp);
438 NDFREE(ndp, NDF_ONLY_PNBUF);
443 ++mycpu->gd_cnt.v_exec;
448 /* we're done here, clear P_INEXEC */
449 p->p_flag &= ~P_INEXEC;
450 if (imgp->vmspace_destroyed) {
451 /* sorry, no more process anymore. exit gracefully */
452 exit1(W_EXITCODE(0, SIGABRT));
461 * execve() system call.
464 execve(struct execve_args *uap)
466 struct thread *td = curthread;
468 struct image_args args;
471 NDINIT(&nd, NAMEI_LOOKUP, CNP_LOCKLEAF | CNP_FOLLOW | CNP_SAVENAME,
472 UIO_USERSPACE, uap->fname, td);
474 error = exec_copyin_args(&args, uap->fname, PATH_USERSPACE,
475 uap->argv, uap->envv);
477 error = kern_execve(&nd, &args);
479 exec_free_args(&args);
482 * The syscall result is returned in registers to the new program.
483 * Linux will register %edx as an atexit function and we must be
484 * sure to set it to 0. XXX
487 uap->sysmsg_result64 = 0;
493 exec_map_first_page(struct image_params *imgp)
497 vm_page_t ma[VM_INITIAL_PAGEIN];
502 exec_unmap_first_page(imgp);
504 VOP_GETVOBJECT(imgp->vp, &object);
507 * We shouldn't need protection for vm_page_grab() but we certainly
508 * need it for the lookup loop below (lookup/busy race), since
509 * an interrupt can unbusy and free the page before our busy check.
512 m = vm_page_grab(object, 0, VM_ALLOC_NORMAL | VM_ALLOC_RETRY);
514 if ((m->valid & VM_PAGE_BITS_ALL) != VM_PAGE_BITS_ALL) {
516 initial_pagein = VM_INITIAL_PAGEIN;
517 if (initial_pagein > object->size)
518 initial_pagein = object->size;
519 for (i = 1; i < initial_pagein; i++) {
520 if ((m = vm_page_lookup(object, i)) != NULL) {
521 if ((m->flags & PG_BUSY) || m->busy)
527 m = vm_page_alloc(object, i, VM_ALLOC_NORMAL);
536 * get_pages unbusies all the requested pages except the
537 * primary page (at index 0 in this case).
539 rv = vm_pager_get_pages(object, ma, initial_pagein, 0);
540 m = vm_page_lookup(object, 0);
542 if (rv != VM_PAGER_OK || m == NULL || m->valid == 0) {
544 vm_page_protect(m, VM_PROT_NONE);
552 vm_page_wakeup(m); /* unbusy the page */
555 imgp->firstpage = sf_buf_alloc(m, SFBA_QUICK);
556 imgp->image_header = (void *)sf_buf_kva(imgp->firstpage);
562 exec_unmap_first_page(imgp)
563 struct image_params *imgp;
568 if (imgp->firstpage != NULL) {
569 m = sf_buf_page(imgp->firstpage);
570 sf_buf_free(imgp->firstpage);
571 imgp->firstpage = NULL;
572 imgp->image_header = NULL;
579 * Destroy old address space, and allocate a new stack
580 * The new stack is only SGROWSIZ large because it is grown
581 * automatically in trap.c.
584 exec_new_vmspace(struct image_params *imgp, struct vmspace *vmcopy)
587 struct vmspace *vmspace = imgp->proc->p_vmspace;
588 vm_offset_t stack_addr = USRSTACK - maxssiz;
591 imgp->vmspace_destroyed = 1;
594 * Prevent a pending AIO from modifying the new address space.
596 aio_proc_rundown(imgp->proc);
599 * Blow away entire process VM, if address space not shared,
600 * otherwise, create a new VM space so that other threads are
601 * not disrupted. If we are execing a resident vmspace we
602 * create a duplicate of it and remap the stack.
604 * The exitingcnt test is not strictly necessary but has been
605 * included for code sanity (to make the code more deterministic).
607 map = &vmspace->vm_map;
609 vmspace_exec(imgp->proc, vmcopy);
610 vmspace = imgp->proc->p_vmspace;
611 pmap_remove_pages(vmspace_pmap(vmspace), stack_addr, USRSTACK);
612 map = &vmspace->vm_map;
613 } else if (vmspace->vm_refcnt == 1 && vmspace->vm_exitingcnt == 0) {
615 if (vmspace->vm_upcalls)
616 upc_release(vmspace, imgp->proc);
617 pmap_remove_pages(vmspace_pmap(vmspace), 0, VM_MAXUSER_ADDRESS);
618 vm_map_remove(map, 0, VM_MAXUSER_ADDRESS);
620 vmspace_exec(imgp->proc, NULL);
621 vmspace = imgp->proc->p_vmspace;
622 map = &vmspace->vm_map;
625 /* Allocate a new stack */
626 error = vm_map_stack(&vmspace->vm_map, stack_addr, (vm_size_t)maxssiz,
627 VM_PROT_ALL, VM_PROT_ALL, 0);
631 /* vm_ssize and vm_maxsaddr are somewhat antiquated concepts in the
632 * VM_STACK case, but they are still used to monitor the size of the
633 * process stack so we can check the stack rlimit.
635 vmspace->vm_ssize = sgrowsiz >> PAGE_SHIFT;
636 vmspace->vm_maxsaddr = (char *)USRSTACK - maxssiz;
642 * Copy out argument and environment strings from the old process
643 * address space into the temporary string buffer.
646 exec_copyin_args(struct image_args *args, char *fname,
647 enum exec_path_segflg segflg, char **argv, char **envv)
653 bzero(args, sizeof(*args));
654 args->buf = (char *) kmem_alloc_wait(exec_map, PATH_MAX + ARG_MAX);
655 if (args->buf == NULL)
657 args->begin_argv = args->buf;
658 args->endp = args->begin_argv;
659 args->space = ARG_MAX;
661 args->fname = args->buf + ARG_MAX;
664 * Copy the file name.
666 if (segflg == PATH_SYSSPACE) {
667 error = copystr(fname, args->fname, PATH_MAX, &length);
668 } else if (segflg == PATH_USERSPACE) {
669 error = copyinstr(fname, args->fname, PATH_MAX, &length);
673 * extract argument strings
676 if (argv && error == 0) {
678 * The argv0 argument for execv() is allowed to be NULL,
679 * in which case we use our filename as argv[0].
680 * This guarantees that
681 * the interpreter knows what file to open in the case
682 * that we exec an interpreted file.
684 argp = (caddr_t) (intptr_t) fuword(argv);
686 length = strlen(args->fname) + 1;
687 KKASSERT(length <= args->space);
688 bcopy(args->fname, args->endp, length);
689 args->space -= length;
690 args->endp += length;
694 while ((argp = (caddr_t) (intptr_t) fuword(argv++))) {
695 if (argp == (caddr_t) -1) {
699 error = copyinstr(argp, args->endp,
700 args->space, &length);
701 if (error == ENAMETOOLONG)
705 args->space -= length;
706 args->endp += length;
711 args->begin_envv = args->endp;
714 * extract environment strings
716 if (envv && error == 0) {
717 while ((envp = (caddr_t) (intptr_t) fuword(envv++))) {
718 if (envp == (caddr_t) -1) {
722 error = copyinstr(envp, args->endp, args->space,
724 if (error == ENAMETOOLONG)
728 args->space -= length;
729 args->endp += length;
739 exec_free_args(struct image_args *args)
742 kmem_free_wakeup(exec_map,
743 (vm_offset_t)args->buf, PATH_MAX + ARG_MAX);
749 * Copy strings out to the new process address space, constructing
750 * new arg and env vector tables. Return a pointer to the base
751 * so that it can be used as the initial stack pointer.
754 exec_copyout_strings(struct image_params *imgp)
758 char *stringp, *destp;
759 register_t *stack_base;
760 struct ps_strings *arginfo;
764 * Calculate string base and vector table pointers.
765 * Also deal with signal trampoline code for this exec type.
767 arginfo = (struct ps_strings *)PS_STRINGS;
768 szsigcode = *(imgp->proc->p_sysent->sv_szsigcode);
769 destp = (caddr_t)arginfo - szsigcode - SPARE_USRSPACE -
770 roundup((ARG_MAX - imgp->args->space), sizeof(char *));
776 copyout(imgp->proc->p_sysent->sv_sigcode,
777 ((caddr_t)arginfo - szsigcode), szsigcode);
780 * If we have a valid auxargs ptr, prepare some room
783 * The '+ 2' is for the null pointers at the end of each of the
784 * arg and env vector sets, and 'AT_COUNT*2' is room for the
788 vectp = (char **)(destp - (imgp->args->argc +
789 imgp->args->envc + 2 + AT_COUNT * 2) * sizeof(char*));
791 vectp = (char **)(destp - (imgp->args->argc +
792 imgp->args->envc + 2) * sizeof(char*));
796 * NOTE: don't bother aligning the stack here for GCC 2.x, it will
797 * be done in crt1.o. Note that GCC 3.x aligns the stack in main.
801 * vectp also becomes our initial stack base
803 stack_base = (register_t *)vectp;
805 stringp = imgp->args->begin_argv;
806 argc = imgp->args->argc;
807 envc = imgp->args->envc;
810 * Copy out strings - arguments and environment.
812 copyout(stringp, destp, ARG_MAX - imgp->args->space);
815 * Fill in "ps_strings" struct for ps, w, etc.
817 suword(&arginfo->ps_argvstr, (long)(intptr_t)vectp);
818 suword(&arginfo->ps_nargvstr, argc);
821 * Fill in argument portion of vector table.
823 for (; argc > 0; --argc) {
824 suword(vectp++, (long)(intptr_t)destp);
825 while (*stringp++ != 0)
830 /* a null vector table pointer separates the argp's from the envp's */
833 suword(&arginfo->ps_envstr, (long)(intptr_t)vectp);
834 suword(&arginfo->ps_nenvstr, envc);
837 * Fill in environment portion of vector table.
839 for (; envc > 0; --envc) {
840 suword(vectp++, (long)(intptr_t)destp);
841 while (*stringp++ != 0)
846 /* end of vector table is a null pointer */
853 * Check permissions of file to execute.
854 * Return 0 for success or error code on failure.
857 exec_check_permissions(imgp)
858 struct image_params *imgp;
860 struct proc *p = imgp->proc;
861 struct vnode *vp = imgp->vp;
862 struct vattr *attr = imgp->attr;
863 struct thread *td = p->p_thread;
866 /* Get file attributes */
867 error = VOP_GETATTR(vp, attr, td);
872 * 1) Check if file execution is disabled for the filesystem that this
874 * 2) Insure that at least one execute bit is on - otherwise root
875 * will always succeed, and we don't want to happen unless the
876 * file really is executable.
877 * 3) Insure that the file is a regular file.
879 if ((vp->v_mount->mnt_flag & MNT_NOEXEC) ||
880 ((attr->va_mode & 0111) == 0) ||
881 (attr->va_type != VREG)) {
886 * Zero length files can't be exec'd
888 if (attr->va_size == 0)
892 * Check for execute permission to file based on current credentials.
894 error = VOP_ACCESS(vp, VEXEC, p->p_ucred, td);
899 * Check number of open-for-writes on the file and deny execution
902 if (vp->v_writecount)
906 * Call filesystem specific open routine (which does nothing in the
909 error = VOP_OPEN(vp, FREAD, p->p_ucred, td);
917 * Exec handler registration
920 exec_register(execsw_arg)
921 const struct execsw *execsw_arg;
923 const struct execsw **es, **xs, **newexecsw;
924 int count = 2; /* New slot and trailing NULL */
927 for (es = execsw; *es; es++)
929 newexecsw = malloc(count * sizeof(*es), M_TEMP, M_WAITOK);
930 if (newexecsw == NULL)
934 for (es = execsw; *es; es++)
939 free(execsw, M_TEMP);
945 exec_unregister(execsw_arg)
946 const struct execsw *execsw_arg;
948 const struct execsw **es, **xs, **newexecsw;
952 panic("unregister with no handlers left?");
954 for (es = execsw; *es; es++) {
955 if (*es == execsw_arg)
960 for (es = execsw; *es; es++)
961 if (*es != execsw_arg)
963 newexecsw = malloc(count * sizeof(*es), M_TEMP, M_WAITOK);
964 if (newexecsw == NULL)
967 for (es = execsw; *es; es++)
968 if (*es != execsw_arg)
972 free(execsw, M_TEMP);