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 1.35 2005/10/09 20:12:34 corecode 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/nlookup.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>
55 #include <sys/libkern.h>
58 #include <vm/vm_param.h>
61 #include <vm/vm_page.h>
62 #include <vm/vm_map.h>
63 #include <vm/vm_kern.h>
64 #include <vm/vm_extern.h>
65 #include <vm/vm_object.h>
66 #include <vm/vm_pager.h>
69 #include <machine/reg.h>
71 #include <sys/thread2.h>
73 MALLOC_DEFINE(M_PARGS
, "proc-args", "Process arguments");
75 static register_t
*exec_copyout_strings (struct image_params
*);
77 /* XXX This should be vm_size_t. */
78 static u_long ps_strings
= PS_STRINGS
;
79 SYSCTL_ULONG(_kern
, KERN_PS_STRINGS
, ps_strings
, CTLFLAG_RD
, &ps_strings
, 0, "");
81 /* XXX This should be vm_size_t. */
82 static u_long usrstack
= USRSTACK
;
83 SYSCTL_ULONG(_kern
, KERN_USRSTACK
, usrstack
, CTLFLAG_RD
, &usrstack
, 0, "");
85 u_long ps_arg_cache_limit
= PAGE_SIZE
/ 16;
86 SYSCTL_LONG(_kern
, OID_AUTO
, ps_arg_cache_limit
, CTLFLAG_RW
,
87 &ps_arg_cache_limit
, 0, "");
90 SYSCTL_INT(_kern
, OID_AUTO
, ps_argsopen
, CTLFLAG_RW
, &ps_argsopen
, 0, "");
92 void print_execve_args(struct image_args
*args
);
93 int debug_execve_args
= 0;
94 SYSCTL_INT(_kern
, OID_AUTO
, debug_execve_args
, CTLFLAG_RW
, &debug_execve_args
,
98 * stackgap_random specifies if the stackgap should have a random size added
99 * to it. It must be a power of 2. If non-zero, the stack gap will be
100 * calculated as: ALIGN(arc4random() & (stackgap_random - 1)).
102 static int stackgap_random
= 1024;
104 sysctl_kern_stackgap(SYSCTL_HANDLER_ARGS
)
107 new_val
= stackgap_random
;
108 error
= sysctl_handle_int(oidp
, &new_val
, 0, req
);
109 if (error
!= 0 || req
->newptr
== NULL
)
111 if ((new_val
< 0) || (new_val
> 16 * PAGE_SIZE
) || ! powerof2(new_val
))
113 stackgap_random
= new_val
;
118 SYSCTL_PROC(_kern
, OID_AUTO
, stackgap_random
, CTLFLAG_RW
|CTLTYPE_UINT
,
119 0, 0, sysctl_kern_stackgap
, "IU", "Max random stack gap (power of 2)");
122 print_execve_args(struct image_args
*args
)
127 cp
= args
->begin_argv
;
128 for (ndx
= 0; ndx
< args
->argc
; ndx
++) {
129 printf("\targv[%d]: %s\n", ndx
, cp
);
130 while (*cp
++ != '\0');
132 for (ndx
= 0; ndx
< args
->envc
; ndx
++) {
133 printf("\tenvv[%d]: %s\n", ndx
, cp
);
134 while (*cp
++ != '\0');
139 * Each of the items is a pointer to a `const struct execsw', hence the
140 * double pointer here.
142 static const struct execsw
**execsw
;
145 kern_execve(struct nlookupdata
*nd
, struct image_args
*args
)
147 struct thread
*td
= curthread
;
148 struct proc
*p
= td
->td_proc
;
149 register_t
*stack_base
;
151 struct image_params image_params
, *imgp
;
153 int (*img_first
) (struct image_params
*);
155 if (debug_execve_args
) {
156 printf("%s()\n", __func__
);
157 print_execve_args(args
);
161 imgp
= &image_params
;
164 * Lock the process and set the P_INEXEC flag to indicate that
165 * it should be left alone until we're done here. This is
166 * necessary to avoid race conditions - e.g. in ptrace() -
167 * that might allow a local user to illicitly obtain elevated
170 p
->p_flag
|= P_INEXEC
;
173 * Initialize part of the common data
178 imgp
->entry_addr
= 0;
180 imgp
->vmspace_destroyed
= 0;
181 imgp
->interpreted
= 0;
182 imgp
->interpreter_name
[0] = 0;
183 imgp
->auxargs
= NULL
;
185 imgp
->firstpage
= NULL
;
186 imgp
->ps_strings
= 0;
187 imgp
->image_header
= NULL
;
192 * Translate the file name to a vnode. Unlock the cache entry to
193 * improve parallelism for programs exec'd in parallel.
195 if ((error
= nlookup(nd
)) != 0)
197 error
= cache_vget(nd
->nl_ncp
, nd
->nl_cred
, LK_EXCLUSIVE
, &imgp
->vp
);
198 KKASSERT(nd
->nl_flags
& NLC_NCPISLOCKED
);
199 nd
->nl_flags
&= ~NLC_NCPISLOCKED
;
200 cache_unlock(nd
->nl_ncp
);
205 * Check file permissions (also 'opens' file)
207 error
= exec_check_permissions(imgp
);
209 VOP_UNLOCK(imgp
->vp
, 0, td
);
210 goto exec_fail_dealloc
;
213 error
= exec_map_first_page(imgp
);
214 VOP_UNLOCK(imgp
->vp
, 0, td
);
216 goto exec_fail_dealloc
;
218 if (debug_execve_args
&& imgp
->interpreted
) {
219 printf(" target is interpreted -- recursive pass\n");
220 printf(" interpreter: %s\n", imgp
->interpreter_name
);
221 print_execve_args(args
);
225 * If the current process has a special image activator it
226 * wants to try first, call it. For example, emulating shell
227 * scripts differently.
230 if ((img_first
= imgp
->proc
->p_sysent
->sv_imgact_try
) != NULL
)
231 error
= img_first(imgp
);
234 * If the vnode has a registered vmspace, exec the vmspace
236 if (error
== -1 && imgp
->vp
->v_resident
) {
237 error
= exec_resident_imgact(imgp
);
241 * Loop through the list of image activators, calling each one.
242 * An activator returns -1 if there is no match, 0 on success,
243 * and an error otherwise.
245 for (i
= 0; error
== -1 && execsw
[i
]; ++i
) {
246 if (execsw
[i
]->ex_imgact
== NULL
||
247 execsw
[i
]->ex_imgact
== img_first
) {
250 error
= (*execsw
[i
]->ex_imgact
)(imgp
);
256 goto exec_fail_dealloc
;
260 * Special interpreter operation, cleanup and loop up to try to
261 * activate the interpreter.
263 if (imgp
->interpreted
) {
264 exec_unmap_first_page(imgp
);
268 error
= nlookup_init(nd
, imgp
->interpreter_name
, UIO_SYSSPACE
,
276 * Copy out strings (args and env) and initialize stack base
278 stack_base
= exec_copyout_strings(imgp
);
279 p
->p_vmspace
->vm_minsaddr
= (char *)stack_base
;
282 * If custom stack fixup routine present for this process
283 * let it do the stack setup. If we are running a resident
284 * image there is no auxinfo or other image activator context
285 * so don't try to add fixups to the stack.
287 * Else stuff argument count as first item on stack
289 if (p
->p_sysent
->sv_fixup
&& imgp
->resident
== 0)
290 (*p
->p_sysent
->sv_fixup
)(&stack_base
, imgp
);
292 suword(--stack_base
, imgp
->args
->argc
);
295 * For security and other reasons, the file descriptor table cannot
296 * be shared after an exec.
298 if (p
->p_fd
->fd_refcnt
> 1) {
299 struct filedesc
*tmp
;
307 * For security and other reasons, signal handlers cannot
308 * be shared after an exec. The new proces gets a copy of the old
309 * handlers. In execsigs(), the new process will have its signals
312 if (p
->p_procsig
->ps_refcnt
> 1) {
313 struct procsig
*newprocsig
;
315 MALLOC(newprocsig
, struct procsig
*, sizeof(struct procsig
),
316 M_SUBPROC
, M_WAITOK
);
317 bcopy(p
->p_procsig
, newprocsig
, sizeof(*newprocsig
));
318 p
->p_procsig
->ps_refcnt
--;
319 p
->p_procsig
= newprocsig
;
320 p
->p_procsig
->ps_refcnt
= 1;
321 if (p
->p_sigacts
== &p
->p_addr
->u_sigacts
)
322 panic("shared procsig but private sigacts?");
324 p
->p_addr
->u_sigacts
= *p
->p_sigacts
;
325 p
->p_sigacts
= &p
->p_addr
->u_sigacts
;
331 /* close files on exec */
334 /* reset caught signals */
337 /* name this process - nameiexec(p, ndp) */
338 len
= min(nd
->nl_ncp
->nc_nlen
, MAXCOMLEN
);
339 bcopy(nd
->nl_ncp
->nc_name
, p
->p_comm
, len
);
341 bcopy(p
->p_comm
, p
->p_lwp
.lwp_thread
->td_comm
, MAXCOMLEN
+1);
344 * mark as execed, wakeup the process that vforked (if any) and tell
345 * it that it now has its own resources back
348 if (p
->p_pptr
&& (p
->p_flag
& P_PPWAIT
)) {
349 p
->p_flag
&= ~P_PPWAIT
;
350 wakeup((caddr_t
)p
->p_pptr
);
354 * Implement image setuid/setgid.
356 * Don't honor setuid/setgid if the filesystem prohibits it or if
357 * the process is being traced.
359 if ((((attr
.va_mode
& VSUID
) && p
->p_ucred
->cr_uid
!= attr
.va_uid
) ||
360 ((attr
.va_mode
& VSGID
) && p
->p_ucred
->cr_gid
!= attr
.va_gid
)) &&
361 (imgp
->vp
->v_mount
->mnt_flag
& MNT_NOSUID
) == 0 &&
362 (p
->p_flag
& P_TRACED
) == 0) {
364 * Turn off syscall tracing for set-id programs, except for
365 * root. Record any set-id flags first to make sure that
366 * we do not regain any tracing during a possible block.
369 if (p
->p_tracep
&& suser(td
)) {
372 if ((vtmp
= p
->p_tracep
) != NULL
) {
378 /* Close any file descriptors 0..2 that reference procfs */
380 /* Make sure file descriptors 0..2 are in use. */
381 error
= fdcheckstd(p
);
383 goto exec_fail_dealloc
;
385 * Set the new credentials.
388 if (attr
.va_mode
& VSUID
)
389 change_euid(attr
.va_uid
);
390 if (attr
.va_mode
& VSGID
)
391 p
->p_ucred
->cr_gid
= attr
.va_gid
;
394 * Clear local varsym variables
396 varsymset_clean(&p
->p_varsymset
);
398 if (p
->p_ucred
->cr_uid
== p
->p_ucred
->cr_ruid
&&
399 p
->p_ucred
->cr_gid
== p
->p_ucred
->cr_rgid
)
400 p
->p_flag
&= ~P_SUGID
;
404 * Implement correct POSIX saved-id behavior.
406 if (p
->p_ucred
->cr_svuid
!= p
->p_ucred
->cr_uid
||
407 p
->p_ucred
->cr_svgid
!= p
->p_ucred
->cr_gid
) {
409 p
->p_ucred
->cr_svuid
= p
->p_ucred
->cr_uid
;
410 p
->p_ucred
->cr_svgid
= p
->p_ucred
->cr_gid
;
414 * Store the vp for use in procfs
416 if (p
->p_textvp
) /* release old reference */
418 p
->p_textvp
= imgp
->vp
;
422 * Notify others that we exec'd, and clear the P_INEXEC flag
423 * as we're now a bona fide freshly-execed process.
425 KNOTE(&p
->p_klist
, NOTE_EXEC
);
426 p
->p_flag
&= ~P_INEXEC
;
429 * If tracing the process, trap to debugger so breakpoints
430 * can be set before the program executes.
432 STOPEVENT(p
, S_EXEC
, 0);
434 if (p
->p_flag
& P_TRACED
)
437 /* clear "fork but no exec" flag, as we _are_ execing */
438 p
->p_acflag
&= ~AFORK
;
440 /* Set values passed into the program in registers. */
441 setregs(p
, imgp
->entry_addr
, (u_long
)(uintptr_t)stack_base
,
444 /* Free any previous argument cache */
445 if (p
->p_args
&& --p
->p_args
->ar_ref
== 0)
446 FREE(p
->p_args
, M_PARGS
);
449 /* Cache arguments if they fit inside our allowance */
450 i
= imgp
->args
->begin_envv
- imgp
->args
->begin_argv
;
451 if (ps_arg_cache_limit
>= i
+ sizeof(struct pargs
)) {
452 MALLOC(p
->p_args
, struct pargs
*, sizeof(struct pargs
) + i
,
454 p
->p_args
->ar_ref
= 1;
455 p
->p_args
->ar_length
= i
;
456 bcopy(imgp
->args
->begin_argv
, p
->p_args
->ar_args
, i
);
462 * free various allocated resources
465 exec_unmap_first_page(imgp
);
473 ++mycpu
->gd_cnt
.v_exec
;
478 /* we're done here, clear P_INEXEC */
479 p
->p_flag
&= ~P_INEXEC
;
480 if (imgp
->vmspace_destroyed
) {
481 /* sorry, no more process anymore. exit gracefully */
482 exit1(W_EXITCODE(0, SIGABRT
));
491 * execve() system call.
494 execve(struct execve_args
*uap
)
496 struct nlookupdata nd
;
497 struct image_args args
;
500 error
= nlookup_init(&nd
, uap
->fname
, UIO_USERSPACE
, NLC_FOLLOW
);
502 error
= exec_copyin_args(&args
, uap
->fname
, PATH_USERSPACE
,
503 uap
->argv
, uap
->envv
);
506 error
= kern_execve(&nd
, &args
);
508 exec_free_args(&args
);
511 * The syscall result is returned in registers to the new program.
512 * Linux will register %edx as an atexit function and we must be
513 * sure to set it to 0. XXX
516 uap
->sysmsg_result64
= 0;
522 exec_map_first_page(struct image_params
*imgp
)
526 vm_page_t ma
[VM_INITIAL_PAGEIN
];
532 exec_unmap_first_page(imgp
);
535 * XXX the callers should really use vn_open so we don't have to
538 if ((error
= VOP_GETVOBJECT(imgp
->vp
, &object
)) != 0) {
539 if (vn_canvmio(imgp
->vp
) == TRUE
) {
540 error
= vfs_object_create(imgp
->vp
, curthread
);
542 error
= VOP_GETVOBJECT(imgp
->vp
, &object
);
549 * We shouldn't need protection for vm_page_grab() but we certainly
550 * need it for the lookup loop below (lookup/busy race), since
551 * an interrupt can unbusy and free the page before our busy check.
554 m
= vm_page_grab(object
, 0, VM_ALLOC_NORMAL
| VM_ALLOC_RETRY
);
556 if ((m
->valid
& VM_PAGE_BITS_ALL
) != VM_PAGE_BITS_ALL
) {
558 initial_pagein
= VM_INITIAL_PAGEIN
;
559 if (initial_pagein
> object
->size
)
560 initial_pagein
= object
->size
;
561 for (i
= 1; i
< initial_pagein
; i
++) {
562 if ((m
= vm_page_lookup(object
, i
)) != NULL
) {
563 if ((m
->flags
& PG_BUSY
) || m
->busy
)
569 m
= vm_page_alloc(object
, i
, VM_ALLOC_NORMAL
);
578 * get_pages unbusies all the requested pages except the
579 * primary page (at index 0 in this case).
581 rv
= vm_pager_get_pages(object
, ma
, initial_pagein
, 0);
582 m
= vm_page_lookup(object
, 0);
584 if (rv
!= VM_PAGER_OK
|| m
== NULL
|| m
->valid
== 0) {
586 vm_page_protect(m
, VM_PROT_NONE
);
594 vm_page_wakeup(m
); /* unbusy the page */
597 imgp
->firstpage
= sf_buf_alloc(m
, SFB_CPUPRIVATE
);
598 imgp
->image_header
= (void *)sf_buf_kva(imgp
->firstpage
);
604 exec_unmap_first_page(struct image_params
*imgp
)
609 if (imgp
->firstpage
!= NULL
) {
610 m
= sf_buf_page(imgp
->firstpage
);
611 sf_buf_free(imgp
->firstpage
);
612 imgp
->firstpage
= NULL
;
613 imgp
->image_header
= NULL
;
620 * Destroy old address space, and allocate a new stack
621 * The new stack is only SGROWSIZ large because it is grown
622 * automatically in trap.c.
625 exec_new_vmspace(struct image_params
*imgp
, struct vmspace
*vmcopy
)
628 struct vmspace
*vmspace
= imgp
->proc
->p_vmspace
;
629 vm_offset_t stack_addr
= USRSTACK
- maxssiz
;
632 imgp
->vmspace_destroyed
= 1;
635 * Prevent a pending AIO from modifying the new address space.
637 aio_proc_rundown(imgp
->proc
);
640 * Blow away entire process VM, if address space not shared,
641 * otherwise, create a new VM space so that other threads are
642 * not disrupted. If we are execing a resident vmspace we
643 * create a duplicate of it and remap the stack.
645 * The exitingcnt test is not strictly necessary but has been
646 * included for code sanity (to make the code more deterministic).
648 map
= &vmspace
->vm_map
;
650 vmspace_exec(imgp
->proc
, vmcopy
);
651 vmspace
= imgp
->proc
->p_vmspace
;
652 pmap_remove_pages(vmspace_pmap(vmspace
), stack_addr
, USRSTACK
);
653 map
= &vmspace
->vm_map
;
654 } else if (vmspace
->vm_refcnt
== 1 && vmspace
->vm_exitingcnt
== 0) {
656 if (vmspace
->vm_upcalls
)
657 upc_release(vmspace
, &imgp
->proc
->p_lwp
);
658 pmap_remove_pages(vmspace_pmap(vmspace
), 0, VM_MAXUSER_ADDRESS
);
659 vm_map_remove(map
, 0, VM_MAXUSER_ADDRESS
);
661 vmspace_exec(imgp
->proc
, NULL
);
662 vmspace
= imgp
->proc
->p_vmspace
;
663 map
= &vmspace
->vm_map
;
666 /* Allocate a new stack */
667 error
= vm_map_stack(&vmspace
->vm_map
, stack_addr
, (vm_size_t
)maxssiz
,
668 VM_PROT_ALL
, VM_PROT_ALL
, 0);
672 /* vm_ssize and vm_maxsaddr are somewhat antiquated concepts in the
673 * VM_STACK case, but they are still used to monitor the size of the
674 * process stack so we can check the stack rlimit.
676 vmspace
->vm_ssize
= sgrowsiz
>> PAGE_SHIFT
;
677 vmspace
->vm_maxsaddr
= (char *)USRSTACK
- maxssiz
;
683 * Copy out argument and environment strings from the old process
684 * address space into the temporary string buffer.
687 exec_copyin_args(struct image_args
*args
, char *fname
,
688 enum exec_path_segflg segflg
, char **argv
, char **envv
)
694 bzero(args
, sizeof(*args
));
695 args
->buf
= (char *) kmem_alloc_wait(exec_map
, PATH_MAX
+ ARG_MAX
);
696 if (args
->buf
== NULL
)
698 args
->begin_argv
= args
->buf
;
699 args
->endp
= args
->begin_argv
;
700 args
->space
= ARG_MAX
;
702 args
->fname
= args
->buf
+ ARG_MAX
;
705 * Copy the file name.
707 if (segflg
== PATH_SYSSPACE
) {
708 error
= copystr(fname
, args
->fname
, PATH_MAX
, &length
);
709 } else if (segflg
== PATH_USERSPACE
) {
710 error
= copyinstr(fname
, args
->fname
, PATH_MAX
, &length
);
714 * Extract argument strings. argv may not be NULL. The argv
715 * array is terminated by a NULL entry. We special-case the
716 * situation where argv[0] is NULL by passing { filename, NULL }
717 * to the new program to guarentee that the interpreter knows what
718 * file to open in case we exec an interpreted file. Note that
719 * a NULL argv[0] terminates the argv[] array.
721 * XXX the special-casing of argv[0] is historical and needs to be
727 while ((argp
= (caddr_t
)(intptr_t)fuword(argv
++)) != NULL
) {
728 if (argp
== (caddr_t
)-1) {
732 error
= copyinstr(argp
, args
->endp
,
733 args
->space
, &length
);
735 if (error
== ENAMETOOLONG
)
739 args
->space
-= length
;
740 args
->endp
+= length
;
743 if (args
->argc
== 0 && error
== 0) {
744 length
= strlen(args
->fname
) + 1;
745 if (length
> args
->space
) {
748 bcopy(args
->fname
, args
->endp
, length
);
749 args
->space
-= length
;
750 args
->endp
+= length
;
756 args
->begin_envv
= args
->endp
;
759 * extract environment strings. envv may be NULL.
761 if (envv
&& error
== 0) {
762 while ((envp
= (caddr_t
) (intptr_t) fuword(envv
++))) {
763 if (envp
== (caddr_t
) -1) {
767 error
= copyinstr(envp
, args
->endp
, args
->space
,
770 if (error
== ENAMETOOLONG
)
774 args
->space
-= length
;
775 args
->endp
+= length
;
783 exec_free_args(struct image_args
*args
)
786 kmem_free_wakeup(exec_map
,
787 (vm_offset_t
)args
->buf
, PATH_MAX
+ ARG_MAX
);
793 * Copy strings out to the new process address space, constructing
794 * new arg and env vector tables. Return a pointer to the base
795 * so that it can be used as the initial stack pointer.
798 exec_copyout_strings(struct image_params
*imgp
)
800 int argc
, envc
, sgap
;
802 char *stringp
, *destp
;
803 register_t
*stack_base
;
804 struct ps_strings
*arginfo
;
808 * Calculate string base and vector table pointers.
809 * Also deal with signal trampoline code for this exec type.
811 arginfo
= (struct ps_strings
*)PS_STRINGS
;
812 szsigcode
= *(imgp
->proc
->p_sysent
->sv_szsigcode
);
813 if (stackgap_random
!= 0)
814 sgap
= ALIGN(arc4random() & (stackgap_random
- 1));
817 destp
= (caddr_t
)arginfo
- szsigcode
- SPARE_USRSPACE
- sgap
-
818 roundup((ARG_MAX
- imgp
->args
->space
), sizeof(char *));
824 copyout(imgp
->proc
->p_sysent
->sv_sigcode
,
825 ((caddr_t
)arginfo
- szsigcode
), szsigcode
);
828 * If we have a valid auxargs ptr, prepare some room
831 * The '+ 2' is for the null pointers at the end of each of the
832 * arg and env vector sets, and 'AT_COUNT*2' is room for the
836 vectp
= (char **)(destp
- (imgp
->args
->argc
+
837 imgp
->args
->envc
+ 2 + AT_COUNT
* 2) * sizeof(char*));
839 vectp
= (char **)(destp
- (imgp
->args
->argc
+
840 imgp
->args
->envc
+ 2) * sizeof(char*));
844 * NOTE: don't bother aligning the stack here for GCC 2.x, it will
845 * be done in crt1.o. Note that GCC 3.x aligns the stack in main.
849 * vectp also becomes our initial stack base
851 stack_base
= (register_t
*)vectp
;
853 stringp
= imgp
->args
->begin_argv
;
854 argc
= imgp
->args
->argc
;
855 envc
= imgp
->args
->envc
;
858 * Copy out strings - arguments and environment.
860 copyout(stringp
, destp
, ARG_MAX
- imgp
->args
->space
);
863 * Fill in "ps_strings" struct for ps, w, etc.
865 suword(&arginfo
->ps_argvstr
, (long)(intptr_t)vectp
);
866 suword(&arginfo
->ps_nargvstr
, argc
);
869 * Fill in argument portion of vector table.
871 for (; argc
> 0; --argc
) {
872 suword(vectp
++, (long)(intptr_t)destp
);
873 while (*stringp
++ != 0)
878 /* a null vector table pointer separates the argp's from the envp's */
881 suword(&arginfo
->ps_envstr
, (long)(intptr_t)vectp
);
882 suword(&arginfo
->ps_nenvstr
, envc
);
885 * Fill in environment portion of vector table.
887 for (; envc
> 0; --envc
) {
888 suword(vectp
++, (long)(intptr_t)destp
);
889 while (*stringp
++ != 0)
894 /* end of vector table is a null pointer */
901 * Check permissions of file to execute.
902 * Return 0 for success or error code on failure.
905 exec_check_permissions(struct image_params
*imgp
)
907 struct proc
*p
= imgp
->proc
;
908 struct vnode
*vp
= imgp
->vp
;
909 struct vattr
*attr
= imgp
->attr
;
910 struct thread
*td
= p
->p_thread
;
913 /* Get file attributes */
914 error
= VOP_GETATTR(vp
, attr
, td
);
919 * 1) Check if file execution is disabled for the filesystem that this
921 * 2) Insure that at least one execute bit is on - otherwise root
922 * will always succeed, and we don't want to happen unless the
923 * file really is executable.
924 * 3) Insure that the file is a regular file.
926 if ((vp
->v_mount
->mnt_flag
& MNT_NOEXEC
) ||
927 ((attr
->va_mode
& 0111) == 0) ||
928 (attr
->va_type
!= VREG
)) {
933 * Zero length files can't be exec'd
935 if (attr
->va_size
== 0)
939 * Check for execute permission to file based on current credentials.
941 error
= VOP_ACCESS(vp
, VEXEC
, p
->p_ucred
, td
);
946 * Check number of open-for-writes on the file and deny execution
949 if (vp
->v_writecount
)
953 * Call filesystem specific open routine (which does nothing in the
956 error
= VOP_OPEN(vp
, FREAD
, p
->p_ucred
, NULL
, td
);
964 * Exec handler registration
967 exec_register(const struct execsw
*execsw_arg
)
969 const struct execsw
**es
, **xs
, **newexecsw
;
970 int count
= 2; /* New slot and trailing NULL */
973 for (es
= execsw
; *es
; es
++)
975 newexecsw
= malloc(count
* sizeof(*es
), M_TEMP
, M_WAITOK
);
976 if (newexecsw
== NULL
)
980 for (es
= execsw
; *es
; es
++)
985 free(execsw
, M_TEMP
);
991 exec_unregister(const struct execsw
*execsw_arg
)
993 const struct execsw
**es
, **xs
, **newexecsw
;
997 panic("unregister with no handlers left?");
999 for (es
= execsw
; *es
; es
++) {
1000 if (*es
== execsw_arg
)
1005 for (es
= execsw
; *es
; es
++)
1006 if (*es
!= execsw_arg
)
1008 newexecsw
= malloc(count
* sizeof(*es
), M_TEMP
, M_WAITOK
);
1009 if (newexecsw
== NULL
)
1012 for (es
= execsw
; *es
; es
++)
1013 if (*es
!= execsw_arg
)
1017 free(execsw
, M_TEMP
);