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 1.33 2005/06/22 19:40:35 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/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
);
343 * mark as execed, wakeup the process that vforked (if any) and tell
344 * it that it now has its own resources back
347 if (p
->p_pptr
&& (p
->p_flag
& P_PPWAIT
)) {
348 p
->p_flag
&= ~P_PPWAIT
;
349 wakeup((caddr_t
)p
->p_pptr
);
353 * Implement image setuid/setgid.
355 * Don't honor setuid/setgid if the filesystem prohibits it or if
356 * the process is being traced.
358 if ((((attr
.va_mode
& VSUID
) && p
->p_ucred
->cr_uid
!= attr
.va_uid
) ||
359 ((attr
.va_mode
& VSGID
) && p
->p_ucred
->cr_gid
!= attr
.va_gid
)) &&
360 (imgp
->vp
->v_mount
->mnt_flag
& MNT_NOSUID
) == 0 &&
361 (p
->p_flag
& P_TRACED
) == 0) {
363 * Turn off syscall tracing for set-id programs, except for
364 * root. Record any set-id flags first to make sure that
365 * we do not regain any tracing during a possible block.
368 if (p
->p_tracep
&& suser(td
)) {
371 if ((vtmp
= p
->p_tracep
) != NULL
) {
377 /* Close any file descriptors 0..2 that reference procfs */
379 /* Make sure file descriptors 0..2 are in use. */
380 error
= fdcheckstd(p
);
382 goto exec_fail_dealloc
;
384 * Set the new credentials.
387 if (attr
.va_mode
& VSUID
)
388 change_euid(attr
.va_uid
);
389 if (attr
.va_mode
& VSGID
)
390 p
->p_ucred
->cr_gid
= attr
.va_gid
;
393 * Clear local varsym variables
395 varsymset_clean(&p
->p_varsymset
);
397 if (p
->p_ucred
->cr_uid
== p
->p_ucred
->cr_ruid
&&
398 p
->p_ucred
->cr_gid
== p
->p_ucred
->cr_rgid
)
399 p
->p_flag
&= ~P_SUGID
;
403 * Implement correct POSIX saved-id behavior.
405 if (p
->p_ucred
->cr_svuid
!= p
->p_ucred
->cr_uid
||
406 p
->p_ucred
->cr_svgid
!= p
->p_ucred
->cr_gid
) {
408 p
->p_ucred
->cr_svuid
= p
->p_ucred
->cr_uid
;
409 p
->p_ucred
->cr_svgid
= p
->p_ucred
->cr_gid
;
413 * Store the vp for use in procfs
415 if (p
->p_textvp
) /* release old reference */
417 p
->p_textvp
= imgp
->vp
;
421 * Notify others that we exec'd, and clear the P_INEXEC flag
422 * as we're now a bona fide freshly-execed process.
424 KNOTE(&p
->p_klist
, NOTE_EXEC
);
425 p
->p_flag
&= ~P_INEXEC
;
428 * If tracing the process, trap to debugger so breakpoints
429 * can be set before the program executes.
431 STOPEVENT(p
, S_EXEC
, 0);
433 if (p
->p_flag
& P_TRACED
)
436 /* clear "fork but no exec" flag, as we _are_ execing */
437 p
->p_acflag
&= ~AFORK
;
439 /* Set values passed into the program in registers. */
440 setregs(p
, imgp
->entry_addr
, (u_long
)(uintptr_t)stack_base
,
443 /* Free any previous argument cache */
444 if (p
->p_args
&& --p
->p_args
->ar_ref
== 0)
445 FREE(p
->p_args
, M_PARGS
);
448 /* Cache arguments if they fit inside our allowance */
449 i
= imgp
->args
->begin_envv
- imgp
->args
->begin_argv
;
450 if (ps_arg_cache_limit
>= i
+ sizeof(struct pargs
)) {
451 MALLOC(p
->p_args
, struct pargs
*, sizeof(struct pargs
) + i
,
453 p
->p_args
->ar_ref
= 1;
454 p
->p_args
->ar_length
= i
;
455 bcopy(imgp
->args
->begin_argv
, p
->p_args
->ar_args
, i
);
461 * free various allocated resources
464 exec_unmap_first_page(imgp
);
472 ++mycpu
->gd_cnt
.v_exec
;
477 /* we're done here, clear P_INEXEC */
478 p
->p_flag
&= ~P_INEXEC
;
479 if (imgp
->vmspace_destroyed
) {
480 /* sorry, no more process anymore. exit gracefully */
481 exit1(W_EXITCODE(0, SIGABRT
));
490 * execve() system call.
493 execve(struct execve_args
*uap
)
495 struct nlookupdata nd
;
496 struct image_args args
;
499 error
= nlookup_init(&nd
, uap
->fname
, UIO_USERSPACE
, NLC_FOLLOW
);
501 error
= exec_copyin_args(&args
, uap
->fname
, PATH_USERSPACE
,
502 uap
->argv
, uap
->envv
);
505 error
= kern_execve(&nd
, &args
);
507 exec_free_args(&args
);
510 * The syscall result is returned in registers to the new program.
511 * Linux will register %edx as an atexit function and we must be
512 * sure to set it to 0. XXX
515 uap
->sysmsg_result64
= 0;
521 exec_map_first_page(struct image_params
*imgp
)
525 vm_page_t ma
[VM_INITIAL_PAGEIN
];
531 exec_unmap_first_page(imgp
);
534 * XXX the callers should really use vn_open so we don't have to
537 if ((error
= VOP_GETVOBJECT(imgp
->vp
, &object
)) != 0) {
538 if (vn_canvmio(imgp
->vp
) == TRUE
) {
539 error
= vfs_object_create(imgp
->vp
, curthread
);
541 error
= VOP_GETVOBJECT(imgp
->vp
, &object
);
548 * We shouldn't need protection for vm_page_grab() but we certainly
549 * need it for the lookup loop below (lookup/busy race), since
550 * an interrupt can unbusy and free the page before our busy check.
553 m
= vm_page_grab(object
, 0, VM_ALLOC_NORMAL
| VM_ALLOC_RETRY
);
555 if ((m
->valid
& VM_PAGE_BITS_ALL
) != VM_PAGE_BITS_ALL
) {
557 initial_pagein
= VM_INITIAL_PAGEIN
;
558 if (initial_pagein
> object
->size
)
559 initial_pagein
= object
->size
;
560 for (i
= 1; i
< initial_pagein
; i
++) {
561 if ((m
= vm_page_lookup(object
, i
)) != NULL
) {
562 if ((m
->flags
& PG_BUSY
) || m
->busy
)
568 m
= vm_page_alloc(object
, i
, VM_ALLOC_NORMAL
);
577 * get_pages unbusies all the requested pages except the
578 * primary page (at index 0 in this case).
580 rv
= vm_pager_get_pages(object
, ma
, initial_pagein
, 0);
581 m
= vm_page_lookup(object
, 0);
583 if (rv
!= VM_PAGER_OK
|| m
== NULL
|| m
->valid
== 0) {
585 vm_page_protect(m
, VM_PROT_NONE
);
593 vm_page_wakeup(m
); /* unbusy the page */
596 imgp
->firstpage
= sf_buf_alloc(m
, SFB_CPUPRIVATE
);
597 imgp
->image_header
= (void *)sf_buf_kva(imgp
->firstpage
);
603 exec_unmap_first_page(struct image_params
*imgp
)
608 if (imgp
->firstpage
!= NULL
) {
609 m
= sf_buf_page(imgp
->firstpage
);
610 sf_buf_free(imgp
->firstpage
);
611 imgp
->firstpage
= NULL
;
612 imgp
->image_header
= NULL
;
619 * Destroy old address space, and allocate a new stack
620 * The new stack is only SGROWSIZ large because it is grown
621 * automatically in trap.c.
624 exec_new_vmspace(struct image_params
*imgp
, struct vmspace
*vmcopy
)
627 struct vmspace
*vmspace
= imgp
->proc
->p_vmspace
;
628 vm_offset_t stack_addr
= USRSTACK
- maxssiz
;
631 imgp
->vmspace_destroyed
= 1;
634 * Prevent a pending AIO from modifying the new address space.
636 aio_proc_rundown(imgp
->proc
);
639 * Blow away entire process VM, if address space not shared,
640 * otherwise, create a new VM space so that other threads are
641 * not disrupted. If we are execing a resident vmspace we
642 * create a duplicate of it and remap the stack.
644 * The exitingcnt test is not strictly necessary but has been
645 * included for code sanity (to make the code more deterministic).
647 map
= &vmspace
->vm_map
;
649 vmspace_exec(imgp
->proc
, vmcopy
);
650 vmspace
= imgp
->proc
->p_vmspace
;
651 pmap_remove_pages(vmspace_pmap(vmspace
), stack_addr
, USRSTACK
);
652 map
= &vmspace
->vm_map
;
653 } else if (vmspace
->vm_refcnt
== 1 && vmspace
->vm_exitingcnt
== 0) {
655 if (vmspace
->vm_upcalls
)
656 upc_release(vmspace
, imgp
->proc
);
657 pmap_remove_pages(vmspace_pmap(vmspace
), 0, VM_MAXUSER_ADDRESS
);
658 vm_map_remove(map
, 0, VM_MAXUSER_ADDRESS
);
660 vmspace_exec(imgp
->proc
, NULL
);
661 vmspace
= imgp
->proc
->p_vmspace
;
662 map
= &vmspace
->vm_map
;
665 /* Allocate a new stack */
666 error
= vm_map_stack(&vmspace
->vm_map
, stack_addr
, (vm_size_t
)maxssiz
,
667 VM_PROT_ALL
, VM_PROT_ALL
, 0);
671 /* vm_ssize and vm_maxsaddr are somewhat antiquated concepts in the
672 * VM_STACK case, but they are still used to monitor the size of the
673 * process stack so we can check the stack rlimit.
675 vmspace
->vm_ssize
= sgrowsiz
>> PAGE_SHIFT
;
676 vmspace
->vm_maxsaddr
= (char *)USRSTACK
- maxssiz
;
682 * Copy out argument and environment strings from the old process
683 * address space into the temporary string buffer.
686 exec_copyin_args(struct image_args
*args
, char *fname
,
687 enum exec_path_segflg segflg
, char **argv
, char **envv
)
693 bzero(args
, sizeof(*args
));
694 args
->buf
= (char *) kmem_alloc_wait(exec_map
, PATH_MAX
+ ARG_MAX
);
695 if (args
->buf
== NULL
)
697 args
->begin_argv
= args
->buf
;
698 args
->endp
= args
->begin_argv
;
699 args
->space
= ARG_MAX
;
701 args
->fname
= args
->buf
+ ARG_MAX
;
704 * Copy the file name.
706 if (segflg
== PATH_SYSSPACE
) {
707 error
= copystr(fname
, args
->fname
, PATH_MAX
, &length
);
708 } else if (segflg
== PATH_USERSPACE
) {
709 error
= copyinstr(fname
, args
->fname
, PATH_MAX
, &length
);
713 * Extract argument strings. argv may not be NULL. The argv
714 * array is terminated by a NULL entry. We special-case the
715 * situation where argv[0] is NULL by passing { filename, NULL }
716 * to the new program to guarentee that the interpreter knows what
717 * file to open in case we exec an interpreted file. Note that
718 * a NULL argv[0] terminates the argv[] array.
720 * XXX the special-casing of argv[0] is historical and needs to be
726 while ((argp
= (caddr_t
)(intptr_t)fuword(argv
++)) != NULL
) {
727 if (argp
== (caddr_t
)-1) {
731 error
= copyinstr(argp
, args
->endp
,
732 args
->space
, &length
);
734 if (error
== ENAMETOOLONG
)
738 args
->space
-= length
;
739 args
->endp
+= length
;
742 if (args
->argc
== 0 && error
== 0) {
743 length
= strlen(args
->fname
) + 1;
744 if (length
> args
->space
) {
747 bcopy(args
->fname
, args
->endp
, length
);
748 args
->space
-= length
;
749 args
->endp
+= length
;
755 args
->begin_envv
= args
->endp
;
758 * extract environment strings. envv may be NULL.
760 if (envv
&& error
== 0) {
761 while ((envp
= (caddr_t
) (intptr_t) fuword(envv
++))) {
762 if (envp
== (caddr_t
) -1) {
766 error
= copyinstr(envp
, args
->endp
, args
->space
,
769 if (error
== ENAMETOOLONG
)
773 args
->space
-= length
;
774 args
->endp
+= length
;
782 exec_free_args(struct image_args
*args
)
785 kmem_free_wakeup(exec_map
,
786 (vm_offset_t
)args
->buf
, PATH_MAX
+ ARG_MAX
);
792 * Copy strings out to the new process address space, constructing
793 * new arg and env vector tables. Return a pointer to the base
794 * so that it can be used as the initial stack pointer.
797 exec_copyout_strings(struct image_params
*imgp
)
799 int argc
, envc
, sgap
;
801 char *stringp
, *destp
;
802 register_t
*stack_base
;
803 struct ps_strings
*arginfo
;
807 * Calculate string base and vector table pointers.
808 * Also deal with signal trampoline code for this exec type.
810 arginfo
= (struct ps_strings
*)PS_STRINGS
;
811 szsigcode
= *(imgp
->proc
->p_sysent
->sv_szsigcode
);
812 if (stackgap_random
!= 0)
813 sgap
= ALIGN(arc4random() & (stackgap_random
- 1));
816 destp
= (caddr_t
)arginfo
- szsigcode
- SPARE_USRSPACE
- sgap
-
817 roundup((ARG_MAX
- imgp
->args
->space
), sizeof(char *));
823 copyout(imgp
->proc
->p_sysent
->sv_sigcode
,
824 ((caddr_t
)arginfo
- szsigcode
), szsigcode
);
827 * If we have a valid auxargs ptr, prepare some room
830 * The '+ 2' is for the null pointers at the end of each of the
831 * arg and env vector sets, and 'AT_COUNT*2' is room for the
835 vectp
= (char **)(destp
- (imgp
->args
->argc
+
836 imgp
->args
->envc
+ 2 + AT_COUNT
* 2) * sizeof(char*));
838 vectp
= (char **)(destp
- (imgp
->args
->argc
+
839 imgp
->args
->envc
+ 2) * sizeof(char*));
843 * NOTE: don't bother aligning the stack here for GCC 2.x, it will
844 * be done in crt1.o. Note that GCC 3.x aligns the stack in main.
848 * vectp also becomes our initial stack base
850 stack_base
= (register_t
*)vectp
;
852 stringp
= imgp
->args
->begin_argv
;
853 argc
= imgp
->args
->argc
;
854 envc
= imgp
->args
->envc
;
857 * Copy out strings - arguments and environment.
859 copyout(stringp
, destp
, ARG_MAX
- imgp
->args
->space
);
862 * Fill in "ps_strings" struct for ps, w, etc.
864 suword(&arginfo
->ps_argvstr
, (long)(intptr_t)vectp
);
865 suword(&arginfo
->ps_nargvstr
, argc
);
868 * Fill in argument portion of vector table.
870 for (; argc
> 0; --argc
) {
871 suword(vectp
++, (long)(intptr_t)destp
);
872 while (*stringp
++ != 0)
877 /* a null vector table pointer separates the argp's from the envp's */
880 suword(&arginfo
->ps_envstr
, (long)(intptr_t)vectp
);
881 suword(&arginfo
->ps_nenvstr
, envc
);
884 * Fill in environment portion of vector table.
886 for (; envc
> 0; --envc
) {
887 suword(vectp
++, (long)(intptr_t)destp
);
888 while (*stringp
++ != 0)
893 /* end of vector table is a null pointer */
900 * Check permissions of file to execute.
901 * Return 0 for success or error code on failure.
904 exec_check_permissions(struct image_params
*imgp
)
906 struct proc
*p
= imgp
->proc
;
907 struct vnode
*vp
= imgp
->vp
;
908 struct vattr
*attr
= imgp
->attr
;
909 struct thread
*td
= p
->p_thread
;
912 /* Get file attributes */
913 error
= VOP_GETATTR(vp
, attr
, td
);
918 * 1) Check if file execution is disabled for the filesystem that this
920 * 2) Insure that at least one execute bit is on - otherwise root
921 * will always succeed, and we don't want to happen unless the
922 * file really is executable.
923 * 3) Insure that the file is a regular file.
925 if ((vp
->v_mount
->mnt_flag
& MNT_NOEXEC
) ||
926 ((attr
->va_mode
& 0111) == 0) ||
927 (attr
->va_type
!= VREG
)) {
932 * Zero length files can't be exec'd
934 if (attr
->va_size
== 0)
938 * Check for execute permission to file based on current credentials.
940 error
= VOP_ACCESS(vp
, VEXEC
, p
->p_ucred
, td
);
945 * Check number of open-for-writes on the file and deny execution
948 if (vp
->v_writecount
)
952 * Call filesystem specific open routine (which does nothing in the
955 error
= VOP_OPEN(vp
, FREAD
, p
->p_ucred
, NULL
, td
);
963 * Exec handler registration
966 exec_register(const struct execsw
*execsw_arg
)
968 const struct execsw
**es
, **xs
, **newexecsw
;
969 int count
= 2; /* New slot and trailing NULL */
972 for (es
= execsw
; *es
; es
++)
974 newexecsw
= malloc(count
* sizeof(*es
), M_TEMP
, M_WAITOK
);
975 if (newexecsw
== NULL
)
979 for (es
= execsw
; *es
; es
++)
984 free(execsw
, M_TEMP
);
990 exec_unregister(const struct execsw
*execsw_arg
)
992 const struct execsw
**es
, **xs
, **newexecsw
;
996 panic("unregister with no handlers left?");
998 for (es
= execsw
; *es
; es
++) {
999 if (*es
== execsw_arg
)
1004 for (es
= execsw
; *es
; es
++)
1005 if (*es
!= execsw_arg
)
1007 newexecsw
= malloc(count
* sizeof(*es
), M_TEMP
, M_WAITOK
);
1008 if (newexecsw
== NULL
)
1011 for (es
= execsw
; *es
; es
++)
1012 if (*es
!= execsw_arg
)
1016 free(execsw
, M_TEMP
);