xref: /freebsd/sys/kern/kern_exec.c (revision 1616db3cf893ccad936692f1b5f07218fca82924)
126f9a767SRodney W. Grimes /*
226f9a767SRodney W. Grimes  * Copyright (c) 1993, David Greenman
326f9a767SRodney W. Grimes  * All rights reserved.
4df8bae1dSRodney W. Grimes  *
5df8bae1dSRodney W. Grimes  * Redistribution and use in source and binary forms, with or without
6df8bae1dSRodney W. Grimes  * modification, are permitted provided that the following conditions
7df8bae1dSRodney W. Grimes  * are met:
8df8bae1dSRodney W. Grimes  * 1. Redistributions of source code must retain the above copyright
9df8bae1dSRodney W. Grimes  *    notice, this list of conditions and the following disclaimer.
10df8bae1dSRodney W. Grimes  * 2. Redistributions in binary form must reproduce the above copyright
11df8bae1dSRodney W. Grimes  *    notice, this list of conditions and the following disclaimer in the
12df8bae1dSRodney W. Grimes  *    documentation and/or other materials provided with the distribution.
13df8bae1dSRodney W. Grimes  *
1426f9a767SRodney W. Grimes  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15df8bae1dSRodney W. Grimes  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16df8bae1dSRodney W. Grimes  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
1726f9a767SRodney W. Grimes  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18df8bae1dSRodney W. Grimes  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19df8bae1dSRodney W. Grimes  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20df8bae1dSRodney W. Grimes  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21df8bae1dSRodney W. Grimes  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22df8bae1dSRodney W. Grimes  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23df8bae1dSRodney W. Grimes  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24df8bae1dSRodney W. Grimes  * SUCH DAMAGE.
25df8bae1dSRodney W. Grimes  *
261616db3cSJohn Dyson  *	$Id: kern_exec.c,v 1.73 1998/01/06 05:15:34 dyson Exp $
27df8bae1dSRodney W. Grimes  */
28df8bae1dSRodney W. Grimes 
29df8bae1dSRodney W. Grimes #include <sys/param.h>
3026f9a767SRodney W. Grimes #include <sys/systm.h>
31d2d3e875SBruce Evans #include <sys/sysproto.h>
3226f9a767SRodney W. Grimes #include <sys/signalvar.h>
3326f9a767SRodney W. Grimes #include <sys/kernel.h>
3426f9a767SRodney W. Grimes #include <sys/mount.h>
35797f2d22SPoul-Henning Kamp #include <sys/filedesc.h>
36079cc25bSDavid Greenman #include <sys/fcntl.h>
3726f9a767SRodney W. Grimes #include <sys/acct.h>
3826f9a767SRodney W. Grimes #include <sys/exec.h>
3926f9a767SRodney W. Grimes #include <sys/imgact.h>
40e1743d02SSøren Schmidt #include <sys/imgact_elf.h>
4126f9a767SRodney W. Grimes #include <sys/wait.h>
42a794e791SBruce Evans #include <sys/proc.h>
432a024a2bSSean Eric Fagan #include <sys/pioctl.h>
4426f9a767SRodney W. Grimes #include <sys/malloc.h>
45a794e791SBruce Evans #include <sys/namei.h>
461e1e0b44SSøren Schmidt #include <sys/sysent.h>
47797f2d22SPoul-Henning Kamp #include <sys/shm.h>
4899ac3bc8SPeter Wemm #include <sys/sysctl.h>
49a794e791SBruce Evans #include <sys/vnode.h>
509caaadb6SDavid Greenman #include <sys/buf.h>
5126f9a767SRodney W. Grimes 
5226f9a767SRodney W. Grimes #include <vm/vm.h>
53efeaf95aSDavid Greenman #include <vm/vm_param.h>
54efeaf95aSDavid Greenman #include <vm/vm_prot.h>
55996c772fSJohn Dyson #include <sys/lock.h>
56efeaf95aSDavid Greenman #include <vm/pmap.h>
571616db3cSJohn Dyson #include <vm/vm_page.h>
58efeaf95aSDavid Greenman #include <vm/vm_map.h>
5926f9a767SRodney W. Grimes #include <vm/vm_kern.h>
60efeaf95aSDavid Greenman #include <vm/vm_extern.h>
611ebd0c59SDavid Greenman #include <vm/vm_object.h>
62675ea6f0SBruce Evans #include <vm/vm_zone.h>
631616db3cSJohn Dyson #include <vm/vm_pager.h>
641616db3cSJohn Dyson #include <vm/vm_pageout.h>
6526f9a767SRodney W. Grimes 
6626f9a767SRodney W. Grimes #include <machine/reg.h>
6726f9a767SRodney W. Grimes 
6887b6de2bSPoul-Henning Kamp static int *exec_copyout_strings __P((struct image_params *));
69df8bae1dSRodney W. Grimes 
701616db3cSJohn Dyson static int exec_check_permissions __P((struct image_params *));
711616db3cSJohn Dyson static int exec_map_first_page __P((struct image_params *));
721616db3cSJohn Dyson static void exec_unmap_first_page __P((struct image_params *));
73f23b4c91SGarrett Wollman 
74df8bae1dSRodney W. Grimes /*
7599ac3bc8SPeter Wemm  * XXX trouble here if sizeof(caddr_t) != sizeof(int), other parts
7699ac3bc8SPeter Wemm  * of the sysctl code also assumes this, and sizeof(int) == sizeof(long).
7799ac3bc8SPeter Wemm  */
786120fef1SDavid Greenman static struct ps_strings *ps_strings = PS_STRINGS;
7999ac3bc8SPeter Wemm SYSCTL_INT(_kern, KERN_PS_STRINGS, ps_strings, 0, &ps_strings, 0, "");
8099ac3bc8SPeter Wemm 
8199ac3bc8SPeter Wemm static caddr_t usrstack = (caddr_t)USRSTACK;
8299ac3bc8SPeter Wemm SYSCTL_INT(_kern, KERN_USRSTACK, usrstack, 0, &usrstack, 0, "");
8399ac3bc8SPeter Wemm 
8499ac3bc8SPeter Wemm /*
8526f9a767SRodney W. Grimes  * execsw_set is constructed for us by the linker.  Each of the items
8626f9a767SRodney W. Grimes  * is a pointer to a `const struct execsw', hence the double pointer here.
87df8bae1dSRodney W. Grimes  */
8887b6de2bSPoul-Henning Kamp static const struct execsw **execsw =
8987b6de2bSPoul-Henning Kamp 	(const struct execsw **)&execsw_set.ls_items[0];
9026f9a767SRodney W. Grimes 
91d2d3e875SBruce Evans #ifndef _SYS_SYSPROTO_H_
92ad7507e2SSteven Wallace struct execve_args {
93ad7507e2SSteven Wallace         char    *fname;
94ad7507e2SSteven Wallace         char    **argv;
95ad7507e2SSteven Wallace         char    **envv;
96ad7507e2SSteven Wallace };
97d2d3e875SBruce Evans #endif
98ad7507e2SSteven Wallace 
9926f9a767SRodney W. Grimes /*
10026f9a767SRodney W. Grimes  * execve() system call.
10126f9a767SRodney W. Grimes  */
10226f9a767SRodney W. Grimes int
103cb226aaaSPoul-Henning Kamp execve(p, uap)
10426f9a767SRodney W. Grimes 	struct proc *p;
10526f9a767SRodney W. Grimes 	register struct execve_args *uap;
106df8bae1dSRodney W. Grimes {
10726f9a767SRodney W. Grimes 	struct nameidata nd, *ndp;
10826f9a767SRodney W. Grimes 	int *stack_base;
109bb56ec4aSPoul-Henning Kamp 	int error, len, i;
110c52007c2SDavid Greenman 	struct image_params image_params, *imgp;
11126f9a767SRodney W. Grimes 	struct vattr attr;
1129caaadb6SDavid Greenman 	struct buf *bp = NULL;
11326f9a767SRodney W. Grimes 
114c52007c2SDavid Greenman 	imgp = &image_params;
115df8bae1dSRodney W. Grimes 
116df8bae1dSRodney W. Grimes 	/*
117c52007c2SDavid Greenman 	 * Initialize part of the common data
118df8bae1dSRodney W. Grimes 	 */
119c52007c2SDavid Greenman 	imgp->proc = p;
120c52007c2SDavid Greenman 	imgp->uap = uap;
121c52007c2SDavid Greenman 	imgp->attr = &attr;
122c52007c2SDavid Greenman 	imgp->argc = imgp->envc = 0;
1235cf3d12cSAndrey A. Chernov 	imgp->argv0 = NULL;
124c52007c2SDavid Greenman 	imgp->entry_addr = 0;
125c52007c2SDavid Greenman 	imgp->vmspace_destroyed = 0;
126c52007c2SDavid Greenman 	imgp->interpreted = 0;
127c52007c2SDavid Greenman 	imgp->interpreter_name[0] = '\0';
128e1743d02SSøren Schmidt 	imgp->auxargs = NULL;
1291616db3cSJohn Dyson 	imgp->vp = NULL;
1301616db3cSJohn Dyson 	imgp->firstpage = NULL;
13126f9a767SRodney W. Grimes 
13226f9a767SRodney W. Grimes 	/*
13326f9a767SRodney W. Grimes 	 * Allocate temporary demand zeroed space for argument and
13426f9a767SRodney W. Grimes 	 *	environment strings
13526f9a767SRodney W. Grimes 	 */
1361616db3cSJohn Dyson 	imgp->stringbase = (char *)kmem_alloc_wait(exec_map, ARG_MAX + PAGE_SIZE);
137c2f9f36bSDavid Greenman 	if (imgp->stringbase == NULL) {
13826f9a767SRodney W. Grimes 		error = ENOMEM;
13926f9a767SRodney W. Grimes 		goto exec_fail;
14026f9a767SRodney W. Grimes 	}
141c52007c2SDavid Greenman 	imgp->stringp = imgp->stringbase;
142c52007c2SDavid Greenman 	imgp->stringspace = ARG_MAX;
1431616db3cSJohn Dyson 	imgp->image_header = imgp->stringbase + ARG_MAX;
14426f9a767SRodney W. Grimes 
14526f9a767SRodney W. Grimes 	/*
14626f9a767SRodney W. Grimes 	 * Translate the file name. namei() returns a vnode pointer
14726f9a767SRodney W. Grimes 	 *	in ni_vp amoung other things.
14826f9a767SRodney W. Grimes 	 */
14926f9a767SRodney W. Grimes 	ndp = &nd;
150b35ba931SDavid Greenman 	NDINIT(ndp, LOOKUP, LOCKLEAF | FOLLOW | SAVENAME,
1513ed8a403SDavid Greenman 	    UIO_USERSPACE, uap->fname, p);
15226f9a767SRodney W. Grimes 
15326f9a767SRodney W. Grimes interpret:
15426f9a767SRodney W. Grimes 
15526f9a767SRodney W. Grimes 	error = namei(ndp);
15626f9a767SRodney W. Grimes 	if (error) {
1571616db3cSJohn Dyson 		kmem_free_wakeup(exec_map, (vm_offset_t)imgp->stringbase,
1581616db3cSJohn Dyson 			ARG_MAX + PAGE_SIZE);
15926f9a767SRodney W. Grimes 		goto exec_fail;
16026f9a767SRodney W. Grimes 	}
16126f9a767SRodney W. Grimes 
162c52007c2SDavid Greenman 	imgp->vp = ndp->ni_vp;
16326f9a767SRodney W. Grimes 
16426f9a767SRodney W. Grimes 	/*
1659022e4adSDavid Greenman 	 * Check file permissions (also 'opens' file)
1669022e4adSDavid Greenman 	 */
167c52007c2SDavid Greenman 	error = exec_check_permissions(imgp);
1688677f509SDavid Greenman 	if (error) {
1698677f509SDavid Greenman 		VOP_UNLOCK(imgp->vp, 0, p);
17026f9a767SRodney W. Grimes 		goto exec_fail_dealloc;
1718677f509SDavid Greenman 	}
17226f9a767SRodney W. Grimes 
1731616db3cSJohn Dyson 	error = exec_map_first_page(imgp);
1749caaadb6SDavid Greenman 	VOP_UNLOCK(imgp->vp, 0, p);
1756d5a0a8cSDavid Greenman 	if (error)
17626f9a767SRodney W. Grimes 		goto exec_fail_dealloc;
17726f9a767SRodney W. Grimes 
17826f9a767SRodney W. Grimes 	/*
17926f9a767SRodney W. Grimes 	 * Loop through list of image activators, calling each one.
18026f9a767SRodney W. Grimes 	 *	If there is no match, the activator returns -1. If there
18126f9a767SRodney W. Grimes 	 *	is a match, but there was an error during the activation,
18226f9a767SRodney W. Grimes 	 *	the error is returned. Otherwise 0 means success. If the
18326f9a767SRodney W. Grimes 	 *	image is interpreted, loop back up and try activating
18426f9a767SRodney W. Grimes 	 *	the interpreter.
18526f9a767SRodney W. Grimes 	 */
18626f9a767SRodney W. Grimes 	for (i = 0; execsw[i]; ++i) {
18726f9a767SRodney W. Grimes 		if (execsw[i]->ex_imgact)
188c52007c2SDavid Greenman 			error = (*execsw[i]->ex_imgact)(imgp);
18926f9a767SRodney W. Grimes 		else
19026f9a767SRodney W. Grimes 			continue;
19126f9a767SRodney W. Grimes 		if (error == -1)
19226f9a767SRodney W. Grimes 			continue;
19326f9a767SRodney W. Grimes 		if (error)
19426f9a767SRodney W. Grimes 			goto exec_fail_dealloc;
195c52007c2SDavid Greenman 		if (imgp->interpreted) {
1961616db3cSJohn Dyson 			exec_unmap_first_page(imgp);
19726f9a767SRodney W. Grimes 			/* free old vnode and name buffer */
198f5277ae7SDavid Greenman 			vrele(ndp->ni_vp);
19999448ed1SJohn Dyson 			zfree(namei_zone, ndp->ni_cnd.cn_pnbuf);
20026f9a767SRodney W. Grimes 			/* set new name to that of the interpreter */
201b35ba931SDavid Greenman 			NDINIT(ndp, LOOKUP, LOCKLEAF | FOLLOW | SAVENAME,
202c52007c2SDavid Greenman 			    UIO_SYSSPACE, imgp->interpreter_name, p);
20326f9a767SRodney W. Grimes 			goto interpret;
20426f9a767SRodney W. Grimes 		}
20526f9a767SRodney W. Grimes 		break;
20626f9a767SRodney W. Grimes 	}
20726f9a767SRodney W. Grimes 	/* If we made it through all the activators and none matched, exit. */
20826f9a767SRodney W. Grimes 	if (error == -1) {
20926f9a767SRodney W. Grimes 		error = ENOEXEC;
21026f9a767SRodney W. Grimes 		goto exec_fail_dealloc;
21126f9a767SRodney W. Grimes 	}
21226f9a767SRodney W. Grimes 
21326f9a767SRodney W. Grimes 	/*
21426f9a767SRodney W. Grimes 	 * Copy out strings (args and env) and initialize stack base
21526f9a767SRodney W. Grimes 	 */
216c52007c2SDavid Greenman 	stack_base = exec_copyout_strings(imgp);
21726f9a767SRodney W. Grimes 	p->p_vmspace->vm_minsaddr = (char *)stack_base;
21826f9a767SRodney W. Grimes 
21926f9a767SRodney W. Grimes 	/*
2201e1e0b44SSøren Schmidt 	 * If custom stack fixup routine present for this process
2211e1e0b44SSøren Schmidt 	 * let it do the stack setup.
2221e1e0b44SSøren Schmidt 	 * Else stuff argument count as first item on stack
22326f9a767SRodney W. Grimes 	 */
2241e1e0b44SSøren Schmidt 	if (p->p_sysent->sv_fixup)
225c52007c2SDavid Greenman 		(*p->p_sysent->sv_fixup)(&stack_base, imgp);
2261e1e0b44SSøren Schmidt 	else
227c52007c2SDavid Greenman 		suword(--stack_base, imgp->argc);
22826f9a767SRodney W. Grimes 
229a78e8d2aSDavid Greenman 	/*
230a78e8d2aSDavid Greenman 	 * For security and other reasons, the file descriptor table cannot
231a78e8d2aSDavid Greenman 	 * be shared after an exec.
232a78e8d2aSDavid Greenman 	 */
233a78e8d2aSDavid Greenman 	if (p->p_fd->fd_refcnt > 1) {
234a78e8d2aSDavid Greenman 		struct filedesc *tmp;
235a78e8d2aSDavid Greenman 
236a78e8d2aSDavid Greenman 		tmp = fdcopy(p);
237a78e8d2aSDavid Greenman 		fdfree(p);
238a78e8d2aSDavid Greenman 		p->p_fd = tmp;
239a78e8d2aSDavid Greenman 	}
240a78e8d2aSDavid Greenman 
24126f9a767SRodney W. Grimes 	/* close files on exec */
24226f9a767SRodney W. Grimes 	fdcloseexec(p);
24326f9a767SRodney W. Grimes 
24426f9a767SRodney W. Grimes 	/* reset caught signals */
24526f9a767SRodney W. Grimes 	execsigs(p);
24626f9a767SRodney W. Grimes 
24726f9a767SRodney W. Grimes 	/* name this process - nameiexec(p, ndp) */
24826f9a767SRodney W. Grimes 	len = min(ndp->ni_cnd.cn_namelen,MAXCOMLEN);
24926f9a767SRodney W. Grimes 	bcopy(ndp->ni_cnd.cn_nameptr, p->p_comm, len);
25026f9a767SRodney W. Grimes 	p->p_comm[len] = 0;
25126f9a767SRodney W. Grimes 
25226f9a767SRodney W. Grimes 	/*
25324b34f09SSujal Patel 	 * mark as execed, wakeup the process that vforked (if any) and tell
25426f9a767SRodney W. Grimes 	 * it that it now has it's own resources back
25526f9a767SRodney W. Grimes 	 */
25626f9a767SRodney W. Grimes 	p->p_flag |= P_EXEC;
25726f9a767SRodney W. Grimes 	if (p->p_pptr && (p->p_flag & P_PPWAIT)) {
25826f9a767SRodney W. Grimes 		p->p_flag &= ~P_PPWAIT;
25926f9a767SRodney W. Grimes 		wakeup((caddr_t)p->p_pptr);
26026f9a767SRodney W. Grimes 	}
26126f9a767SRodney W. Grimes 
26226f9a767SRodney W. Grimes 	/*
263a78e8d2aSDavid Greenman 	 * Implement image setuid/setgid.
264a78e8d2aSDavid Greenman 	 *
265a78e8d2aSDavid Greenman 	 * Don't honor setuid/setgid if the filesystem prohibits it or if
266a78e8d2aSDavid Greenman 	 * the process is being traced.
267c52007c2SDavid Greenman 	 */
268d021ae3dSGuido van Rooij 	if ((attr.va_mode & VSUID && p->p_ucred->cr_uid != attr.va_uid ||
269d021ae3dSGuido van Rooij 	     attr.va_mode & VSGID && p->p_ucred->cr_gid != attr.va_gid) &&
270a78e8d2aSDavid Greenman 	    (imgp->vp->v_mount->mnt_flag & MNT_NOSUID) == 0 &&
271c52007c2SDavid Greenman 	    (p->p_flag & P_TRACED) == 0) {
272c52007c2SDavid Greenman 		/*
273c52007c2SDavid Greenman 		 * Turn off syscall tracing for set-id programs, except for
27426f9a767SRodney W. Grimes 		 * root.
27526f9a767SRodney W. Grimes 		 */
276c52007c2SDavid Greenman 		if (p->p_tracep && suser(p->p_ucred, &p->p_acflag)) {
27726f9a767SRodney W. Grimes 			p->p_traceflag = 0;
27826f9a767SRodney W. Grimes 			vrele(p->p_tracep);
279c52007c2SDavid Greenman 			p->p_tracep = NULL;
28026f9a767SRodney W. Grimes 		}
281c52007c2SDavid Greenman 		/*
282c52007c2SDavid Greenman 		 * Set the new credentials.
283c52007c2SDavid Greenman 		 */
28426f9a767SRodney W. Grimes 		p->p_ucred = crcopy(p->p_ucred);
285c52007c2SDavid Greenman 		if (attr.va_mode & VSUID)
28626f9a767SRodney W. Grimes 			p->p_ucred->cr_uid = attr.va_uid;
287c52007c2SDavid Greenman 		if (attr.va_mode & VSGID)
288d021ae3dSGuido van Rooij 			p->p_ucred->cr_gid = attr.va_gid;
289d5f81602SSean Eric Fagan 		setsugid(p);
290c52007c2SDavid Greenman 	} else {
291e47bda07SDavid Greenman 		if (p->p_ucred->cr_uid == p->p_cred->p_ruid &&
292e47bda07SDavid Greenman 		    p->p_ucred->cr_gid == p->p_cred->p_rgid)
293c52007c2SDavid Greenman 			p->p_flag &= ~P_SUGID;
29426f9a767SRodney W. Grimes 	}
29526f9a767SRodney W. Grimes 
29626f9a767SRodney W. Grimes 	/*
297c52007c2SDavid Greenman 	 * Implement correct POSIX saved-id behavior.
29826f9a767SRodney W. Grimes 	 */
29926f9a767SRodney W. Grimes 	p->p_cred->p_svuid = p->p_ucred->cr_uid;
30026f9a767SRodney W. Grimes 	p->p_cred->p_svgid = p->p_ucred->cr_gid;
30126f9a767SRodney W. Grimes 
30226f9a767SRodney W. Grimes 	/*
3032a531c80SDavid Greenman 	 * Store the vp for use in procfs
3042a531c80SDavid Greenman 	 */
3052a531c80SDavid Greenman 	if (p->p_textvp)		/* release old reference */
3062a531c80SDavid Greenman 		vrele(p->p_textvp);
3072a531c80SDavid Greenman 	VREF(ndp->ni_vp);
3082a531c80SDavid Greenman 	p->p_textvp = ndp->ni_vp;
3092a531c80SDavid Greenman 
3102a531c80SDavid Greenman 	/*
31126f9a767SRodney W. Grimes 	 * If tracing the process, trap to debugger so breakpoints
31226f9a767SRodney W. Grimes 	 * 	can be set before the program executes.
31326f9a767SRodney W. Grimes 	 */
3142a024a2bSSean Eric Fagan 	STOPEVENT(p, S_EXEC, 0);
3152a024a2bSSean Eric Fagan 
31626f9a767SRodney W. Grimes 	if (p->p_flag & P_TRACED)
31726f9a767SRodney W. Grimes 		psignal(p, SIGTRAP);
31826f9a767SRodney W. Grimes 
31926f9a767SRodney W. Grimes 	/* clear "fork but no exec" flag, as we _are_ execing */
32026f9a767SRodney W. Grimes 	p->p_acflag &= ~AFORK;
32126f9a767SRodney W. Grimes 
32226f9a767SRodney W. Grimes 	/* Set entry address */
323c52007c2SDavid Greenman 	setregs(p, imgp->entry_addr, (u_long)stack_base);
32426f9a767SRodney W. Grimes 
3251616db3cSJohn Dyson exec_fail_dealloc:
3261616db3cSJohn Dyson 
32726f9a767SRodney W. Grimes 	/*
32826f9a767SRodney W. Grimes 	 * free various allocated resources
32926f9a767SRodney W. Grimes 	 */
3301616db3cSJohn Dyson 	if (imgp->firstpage)
3311616db3cSJohn Dyson 		exec_unmap_first_page(imgp);
33226f9a767SRodney W. Grimes 
333c2f9f36bSDavid Greenman 	if (imgp->stringbase != NULL)
3341616db3cSJohn Dyson 		kmem_free_wakeup(exec_map, (vm_offset_t)imgp->stringbase,
3351616db3cSJohn Dyson 			ARG_MAX + PAGE_SIZE);
3361616db3cSJohn Dyson 
337a3cf6ebaSDavid Greenman 	if (ndp->ni_vp) {
338f5277ae7SDavid Greenman 		vrele(ndp->ni_vp);
33999448ed1SJohn Dyson 		zfree(namei_zone, ndp->ni_cnd.cn_pnbuf);
340a3cf6ebaSDavid Greenman 	}
34126f9a767SRodney W. Grimes 
3421616db3cSJohn Dyson 	if (error == 0)
3431616db3cSJohn Dyson 		return (0);
3441616db3cSJohn Dyson 
34526f9a767SRodney W. Grimes exec_fail:
346c52007c2SDavid Greenman 	if (imgp->vmspace_destroyed) {
34726f9a767SRodney W. Grimes 		/* sorry, no more process anymore. exit gracefully */
34826f9a767SRodney W. Grimes 		exit1(p, W_EXITCODE(0, SIGABRT));
34926f9a767SRodney W. Grimes 		/* NOT REACHED */
35026f9a767SRodney W. Grimes 		return(0);
35126f9a767SRodney W. Grimes 	} else {
35226f9a767SRodney W. Grimes 		return(error);
35326f9a767SRodney W. Grimes 	}
35426f9a767SRodney W. Grimes }
35526f9a767SRodney W. Grimes 
3561616db3cSJohn Dyson int
3571616db3cSJohn Dyson exec_map_first_page(imgp)
3581616db3cSJohn Dyson 	struct image_params *imgp;
3591616db3cSJohn Dyson {
3601616db3cSJohn Dyson 	int s;
3611616db3cSJohn Dyson 	vm_page_t m;
3621616db3cSJohn Dyson 	vm_object_t object;
3631616db3cSJohn Dyson 
3641616db3cSJohn Dyson 
3651616db3cSJohn Dyson 	if (imgp->firstpage) {
3661616db3cSJohn Dyson 		exec_unmap_first_page(imgp);
3671616db3cSJohn Dyson 	}
3681616db3cSJohn Dyson 
3691616db3cSJohn Dyson 	object = imgp->vp->v_object;
3701616db3cSJohn Dyson 	s = splvm();
3711616db3cSJohn Dyson 
3721616db3cSJohn Dyson retry:
3731616db3cSJohn Dyson 	m = vm_page_lookup(object, 0);
3741616db3cSJohn Dyson 	if (m == NULL) {
3751616db3cSJohn Dyson 		m = vm_page_alloc(object, 0, VM_ALLOC_NORMAL);
3761616db3cSJohn Dyson 		if (m == NULL) {
3771616db3cSJohn Dyson 			VM_WAIT;
3781616db3cSJohn Dyson 			goto retry;
3791616db3cSJohn Dyson 		}
3801616db3cSJohn Dyson 	} else if ((m->flags & PG_BUSY) || m->busy) {
3811616db3cSJohn Dyson 		m->flags |= PG_WANTED;
3821616db3cSJohn Dyson 		tsleep(m, PVM, "execpw", 0);
3831616db3cSJohn Dyson 		goto retry;
3841616db3cSJohn Dyson 	}
3851616db3cSJohn Dyson 
3861616db3cSJohn Dyson 	m->flags |= PG_BUSY;
3871616db3cSJohn Dyson 
3881616db3cSJohn Dyson 	if ((m->valid & VM_PAGE_BITS_ALL) != VM_PAGE_BITS_ALL) {
3891616db3cSJohn Dyson 		int rv;
3901616db3cSJohn Dyson 		rv = vm_pager_get_pages(object, &m, 1, 0);
3911616db3cSJohn Dyson 		if (rv != VM_PAGER_OK) {
3921616db3cSJohn Dyson 			vm_page_protect(m, VM_PROT_NONE);
3931616db3cSJohn Dyson 			vm_page_deactivate(m);
3941616db3cSJohn Dyson 			PAGE_WAKEUP(m);
3951616db3cSJohn Dyson 			splx(s);
3961616db3cSJohn Dyson 			return EIO;
3971616db3cSJohn Dyson 		}
3981616db3cSJohn Dyson 	}
3991616db3cSJohn Dyson 
4001616db3cSJohn Dyson 	vm_page_wire(m);
4011616db3cSJohn Dyson 	PAGE_WAKEUP(m);
4021616db3cSJohn Dyson 	splx(s);
4031616db3cSJohn Dyson 
4041616db3cSJohn Dyson 	pmap_kenter((vm_offset_t) imgp->image_header, VM_PAGE_TO_PHYS(m));
4051616db3cSJohn Dyson 	imgp->firstpage = m;
4061616db3cSJohn Dyson 
4071616db3cSJohn Dyson 	return 0;
4081616db3cSJohn Dyson }
4091616db3cSJohn Dyson 
4101616db3cSJohn Dyson void
4111616db3cSJohn Dyson exec_unmap_first_page(imgp)
4121616db3cSJohn Dyson 	struct image_params *imgp;
4131616db3cSJohn Dyson {
4141616db3cSJohn Dyson 	if (imgp->firstpage) {
4151616db3cSJohn Dyson 		pmap_kremove((vm_offset_t) imgp->image_header);
4161616db3cSJohn Dyson 		vm_page_unwire(imgp->firstpage);
4171616db3cSJohn Dyson 		imgp->firstpage = NULL;
4181616db3cSJohn Dyson 	}
4191616db3cSJohn Dyson }
4201616db3cSJohn Dyson 
42126f9a767SRodney W. Grimes /*
42226f9a767SRodney W. Grimes  * Destroy old address space, and allocate a new stack
42326f9a767SRodney W. Grimes  *	The new stack is only SGROWSIZ large because it is grown
42426f9a767SRodney W. Grimes  *	automatically in trap.c.
42526f9a767SRodney W. Grimes  */
42626f9a767SRodney W. Grimes int
427c52007c2SDavid Greenman exec_new_vmspace(imgp)
428c52007c2SDavid Greenman 	struct image_params *imgp;
42926f9a767SRodney W. Grimes {
43026f9a767SRodney W. Grimes 	int error;
431c52007c2SDavid Greenman 	struct vmspace *vmspace = imgp->proc->p_vmspace;
43226f9a767SRodney W. Grimes 	caddr_t	stack_addr = (caddr_t) (USRSTACK - SGROWSIZ);
433af9ec885SJohn Dyson 	vm_map_t map = &vmspace->vm_map;
43426f9a767SRodney W. Grimes 
435c52007c2SDavid Greenman 	imgp->vmspace_destroyed = 1;
43626f9a767SRodney W. Grimes 
437af9ec885SJohn Dyson 	/*
438af9ec885SJohn Dyson 	 * Blow away entire process VM, if address space not shared,
439af9ec885SJohn Dyson 	 * otherwise, create a new VM space so that other threads are
440af9ec885SJohn Dyson 	 * not disrupted
441af9ec885SJohn Dyson 	 */
442af9ec885SJohn Dyson 	if (vmspace->vm_refcnt == 1) {
4433d903220SDoug Rabson 		if (vmspace->vm_shm)
444c52007c2SDavid Greenman 			shmexit(imgp->proc);
4459d3fbbb5SJohn Dyson 		pmap_remove_pages(&vmspace->vm_pmap, 0, USRSTACK);
446af9ec885SJohn Dyson 		vm_map_remove(map, 0, USRSTACK);
447af9ec885SJohn Dyson 	} else {
448492da96cSJohn Dyson 		vmspace_exec(imgp->proc);
449492da96cSJohn Dyson 		vmspace = imgp->proc->p_vmspace;
450af9ec885SJohn Dyson 		map = &vmspace->vm_map;
451af9ec885SJohn Dyson 	}
45226f9a767SRodney W. Grimes 
45326f9a767SRodney W. Grimes 	/* Allocate a new stack */
4541616db3cSJohn Dyson 	error = vm_map_insert(&vmspace->vm_map, NULL, 0,
4551616db3cSJohn Dyson 		(vm_offset_t) stack_addr, (vm_offset_t) USRSTACK,
4561616db3cSJohn Dyson 		VM_PROT_ALL, VM_PROT_ALL, 0);
45726f9a767SRodney W. Grimes 	if (error)
45826f9a767SRodney W. Grimes 		return (error);
45926f9a767SRodney W. Grimes 
46026f9a767SRodney W. Grimes 	vmspace->vm_ssize = SGROWSIZ >> PAGE_SHIFT;
46126f9a767SRodney W. Grimes 
46226f9a767SRodney W. Grimes 	/* Initialize maximum stack address */
46326f9a767SRodney W. Grimes 	vmspace->vm_maxsaddr = (char *)USRSTACK - MAXSSIZ;
46426f9a767SRodney W. Grimes 
46526f9a767SRodney W. Grimes 	return(0);
46626f9a767SRodney W. Grimes }
46726f9a767SRodney W. Grimes 
46826f9a767SRodney W. Grimes /*
46926f9a767SRodney W. Grimes  * Copy out argument and environment strings from the old process
47026f9a767SRodney W. Grimes  *	address space into the temporary string buffer.
47126f9a767SRodney W. Grimes  */
47226f9a767SRodney W. Grimes int
473c52007c2SDavid Greenman exec_extract_strings(imgp)
474c52007c2SDavid Greenman 	struct image_params *imgp;
47526f9a767SRodney W. Grimes {
47626f9a767SRodney W. Grimes 	char	**argv, **envv;
47726f9a767SRodney W. Grimes 	char	*argp, *envp;
4780fd1a014SDavid Greenman 	int	error, length;
47926f9a767SRodney W. Grimes 
48026f9a767SRodney W. Grimes 	/*
48126f9a767SRodney W. Grimes 	 * extract arguments first
48226f9a767SRodney W. Grimes 	 */
48326f9a767SRodney W. Grimes 
484c52007c2SDavid Greenman 	argv = imgp->uap->argv;
48526f9a767SRodney W. Grimes 
4860fd1a014SDavid Greenman 	if (argv) {
4875cf3d12cSAndrey A. Chernov 		argp = (caddr_t) fuword(argv);
4885cf3d12cSAndrey A. Chernov 		if (argp == (caddr_t) -1)
4895cf3d12cSAndrey A. Chernov 			return (EFAULT);
4905cf3d12cSAndrey A. Chernov 		if (argp)
4915cf3d12cSAndrey A. Chernov 			argv++;
4925cf3d12cSAndrey A. Chernov 		if (imgp->argv0)
4935cf3d12cSAndrey A. Chernov 			argp = imgp->argv0;
4945cf3d12cSAndrey A. Chernov 		if (argp) {
4955cf3d12cSAndrey A. Chernov 			do {
49626f9a767SRodney W. Grimes 				if (argp == (caddr_t) -1)
49726f9a767SRodney W. Grimes 					return (EFAULT);
498c52007c2SDavid Greenman 				if ((error = copyinstr(argp, imgp->stringp,
499c52007c2SDavid Greenman 				    imgp->stringspace, &length))) {
5000fd1a014SDavid Greenman 					if (error == ENAMETOOLONG)
50126f9a767SRodney W. Grimes 						return(E2BIG);
5020fd1a014SDavid Greenman 					return (error);
5030fd1a014SDavid Greenman 				}
504c52007c2SDavid Greenman 				imgp->stringspace -= length;
505c52007c2SDavid Greenman 				imgp->stringp += length;
506c52007c2SDavid Greenman 				imgp->argc++;
5075cf3d12cSAndrey A. Chernov 			} while ((argp = (caddr_t) fuword(argv++)));
50826f9a767SRodney W. Grimes 		}
5090fd1a014SDavid Greenman 	}
51026f9a767SRodney W. Grimes 
51126f9a767SRodney W. Grimes 	/*
51226f9a767SRodney W. Grimes 	 * extract environment strings
51326f9a767SRodney W. Grimes 	 */
51426f9a767SRodney W. Grimes 
515c52007c2SDavid Greenman 	envv = imgp->uap->envv;
51626f9a767SRodney W. Grimes 
5170fd1a014SDavid Greenman 	if (envv) {
518bb56ec4aSPoul-Henning Kamp 		while ((envp = (caddr_t) fuword(envv++))) {
51926f9a767SRodney W. Grimes 			if (envp == (caddr_t) -1)
52026f9a767SRodney W. Grimes 				return (EFAULT);
521c52007c2SDavid Greenman 			if ((error = copyinstr(envp, imgp->stringp,
522c52007c2SDavid Greenman 			    imgp->stringspace, &length))) {
5230fd1a014SDavid Greenman 				if (error == ENAMETOOLONG)
52426f9a767SRodney W. Grimes 					return(E2BIG);
5250fd1a014SDavid Greenman 				return (error);
5260fd1a014SDavid Greenman 			}
527c52007c2SDavid Greenman 			imgp->stringspace -= length;
528c52007c2SDavid Greenman 			imgp->stringp += length;
529c52007c2SDavid Greenman 			imgp->envc++;
53026f9a767SRodney W. Grimes 		}
5310fd1a014SDavid Greenman 	}
53226f9a767SRodney W. Grimes 
53326f9a767SRodney W. Grimes 	return (0);
53426f9a767SRodney W. Grimes }
53526f9a767SRodney W. Grimes 
53626f9a767SRodney W. Grimes /*
53726f9a767SRodney W. Grimes  * Copy strings out to the new process address space, constructing
53826f9a767SRodney W. Grimes  *	new arg and env vector tables. Return a pointer to the base
53926f9a767SRodney W. Grimes  *	so that it can be used as the initial stack pointer.
54026f9a767SRodney W. Grimes  */
54126f9a767SRodney W. Grimes int *
542c52007c2SDavid Greenman exec_copyout_strings(imgp)
543c52007c2SDavid Greenman 	struct image_params *imgp;
54426f9a767SRodney W. Grimes {
54526f9a767SRodney W. Grimes 	int argc, envc;
54626f9a767SRodney W. Grimes 	char **vectp;
54726f9a767SRodney W. Grimes 	char *stringp, *destp;
54826f9a767SRodney W. Grimes 	int *stack_base;
54993f6448cSDavid Greenman 	struct ps_strings *arginfo;
550d66a5066SPeter Wemm 	int szsigcode;
55126f9a767SRodney W. Grimes 
55226f9a767SRodney W. Grimes 	/*
55326f9a767SRodney W. Grimes 	 * Calculate string base and vector table pointers.
554d66a5066SPeter Wemm 	 * Also deal with signal trampoline code for this exec type.
55526f9a767SRodney W. Grimes 	 */
55693f6448cSDavid Greenman 	arginfo = PS_STRINGS;
557d66a5066SPeter Wemm 	szsigcode = *(imgp->proc->p_sysent->sv_szsigcode);
558d66a5066SPeter Wemm 	destp =	(caddr_t)arginfo - szsigcode - SPARE_USRSPACE -
5591ed012f9SPeter Wemm 		roundup((ARG_MAX - imgp->stringspace), sizeof(char *));
5601ed012f9SPeter Wemm 
56126f9a767SRodney W. Grimes 	/*
562d66a5066SPeter Wemm 	 * install sigcode
563d66a5066SPeter Wemm 	 */
564d66a5066SPeter Wemm 	if (szsigcode)
565d66a5066SPeter Wemm 		copyout(imgp->proc->p_sysent->sv_sigcode,
566d66a5066SPeter Wemm 			((caddr_t)arginfo - szsigcode), szsigcode);
567d66a5066SPeter Wemm 
568d66a5066SPeter Wemm 	/*
569e1743d02SSøren Schmidt 	 * If we have a valid auxargs ptr, prepare some room
570e1743d02SSøren Schmidt 	 * on the stack.
571e1743d02SSøren Schmidt 	 */
572e1743d02SSøren Schmidt 	if (imgp->auxargs)
573e1743d02SSøren Schmidt 	/*
574e1743d02SSøren Schmidt 	 * The '+ 2' is for the null pointers at the end of each of the
575e1743d02SSøren Schmidt 	 * arg and env vector sets, and 'AT_COUNT*2' is room for the
576e1743d02SSøren Schmidt 	 * ELF Auxargs data.
577e1743d02SSøren Schmidt 	 */
578e1743d02SSøren Schmidt 		vectp = (char **)(destp - (imgp->argc + imgp->envc + 2 +
579e1743d02SSøren Schmidt 				  AT_COUNT*2) * sizeof(char*));
580e1743d02SSøren Schmidt 	else
581e1743d02SSøren Schmidt 	/*
58226f9a767SRodney W. Grimes 	 * The '+ 2' is for the null pointers at the end of each of the
58326f9a767SRodney W. Grimes 	 * arg and env vector sets
58426f9a767SRodney W. Grimes 	 */
585e1743d02SSøren Schmidt 		vectp = (char **)
586e1743d02SSøren Schmidt 			(destp - (imgp->argc + imgp->envc + 2) * sizeof(char*));
58726f9a767SRodney W. Grimes 
58826f9a767SRodney W. Grimes 	/*
58926f9a767SRodney W. Grimes 	 * vectp also becomes our initial stack base
59026f9a767SRodney W. Grimes 	 */
59126f9a767SRodney W. Grimes 	stack_base = (int *)vectp;
59226f9a767SRodney W. Grimes 
593c52007c2SDavid Greenman 	stringp = imgp->stringbase;
594c52007c2SDavid Greenman 	argc = imgp->argc;
595c52007c2SDavid Greenman 	envc = imgp->envc;
59626f9a767SRodney W. Grimes 
59793f6448cSDavid Greenman 	/*
5983aed948bSDavid Greenman 	 * Copy out strings - arguments and environment.
59993f6448cSDavid Greenman 	 */
600c52007c2SDavid Greenman 	copyout(stringp, destp, ARG_MAX - imgp->stringspace);
60193f6448cSDavid Greenman 
60293f6448cSDavid Greenman 	/*
6033aed948bSDavid Greenman 	 * Fill in "ps_strings" struct for ps, w, etc.
6043aed948bSDavid Greenman 	 */
6051ed012f9SPeter Wemm 	suword(&arginfo->ps_argvstr, (int)vectp);
6063aed948bSDavid Greenman 	suword(&arginfo->ps_nargvstr, argc);
6073aed948bSDavid Greenman 
6083aed948bSDavid Greenman 	/*
6093aed948bSDavid Greenman 	 * Fill in argument portion of vector table.
61093f6448cSDavid Greenman 	 */
61126f9a767SRodney W. Grimes 	for (; argc > 0; --argc) {
6123aed948bSDavid Greenman 		suword(vectp++, (int)destp);
6133aed948bSDavid Greenman 		while (*stringp++ != 0)
6143aed948bSDavid Greenman 			destp++;
6153aed948bSDavid Greenman 		destp++;
61626f9a767SRodney W. Grimes 	}
61726f9a767SRodney W. Grimes 
61826f9a767SRodney W. Grimes 	/* a null vector table pointer seperates the argp's from the envp's */
6196ab46d52SBruce Evans 	suword(vectp++, 0);
62026f9a767SRodney W. Grimes 
6211ed012f9SPeter Wemm 	suword(&arginfo->ps_envstr, (int)vectp);
6223aed948bSDavid Greenman 	suword(&arginfo->ps_nenvstr, envc);
62393f6448cSDavid Greenman 
62493f6448cSDavid Greenman 	/*
6253aed948bSDavid Greenman 	 * Fill in environment portion of vector table.
62693f6448cSDavid Greenman 	 */
62726f9a767SRodney W. Grimes 	for (; envc > 0; --envc) {
6283aed948bSDavid Greenman 		suword(vectp++, (int)destp);
6293aed948bSDavid Greenman 		while (*stringp++ != 0)
6303aed948bSDavid Greenman 			destp++;
6313aed948bSDavid Greenman 		destp++;
63226f9a767SRodney W. Grimes 	}
63326f9a767SRodney W. Grimes 
63426f9a767SRodney W. Grimes 	/* end of vector table is a null pointer */
6356ab46d52SBruce Evans 	suword(vectp, 0);
63626f9a767SRodney W. Grimes 
63726f9a767SRodney W. Grimes 	return (stack_base);
63826f9a767SRodney W. Grimes }
63926f9a767SRodney W. Grimes 
64026f9a767SRodney W. Grimes /*
64126f9a767SRodney W. Grimes  * Check permissions of file to execute.
64226f9a767SRodney W. Grimes  *	Return 0 for success or error code on failure.
64326f9a767SRodney W. Grimes  */
644f23b4c91SGarrett Wollman static int
645c52007c2SDavid Greenman exec_check_permissions(imgp)
646c52007c2SDavid Greenman 	struct image_params *imgp;
64726f9a767SRodney W. Grimes {
648c52007c2SDavid Greenman 	struct proc *p = imgp->proc;
649c52007c2SDavid Greenman 	struct vnode *vp = imgp->vp;
650c52007c2SDavid Greenman 	struct vattr *attr = imgp->attr;
65126f9a767SRodney W. Grimes 	int error;
65226f9a767SRodney W. Grimes 
65326f9a767SRodney W. Grimes 	/* Get file attributes */
654c52007c2SDavid Greenman 	error = VOP_GETATTR(vp, attr, p->p_ucred, p);
65526f9a767SRodney W. Grimes 	if (error)
65626f9a767SRodney W. Grimes 		return (error);
65726f9a767SRodney W. Grimes 
65826f9a767SRodney W. Grimes 	/*
65926f9a767SRodney W. Grimes 	 * 1) Check if file execution is disabled for the filesystem that this
66026f9a767SRodney W. Grimes 	 *	file resides on.
66126f9a767SRodney W. Grimes 	 * 2) Insure that at least one execute bit is on - otherwise root
66226f9a767SRodney W. Grimes 	 *	will always succeed, and we don't want to happen unless the
66326f9a767SRodney W. Grimes 	 *	file really is executable.
66426f9a767SRodney W. Grimes 	 * 3) Insure that the file is a regular file.
66526f9a767SRodney W. Grimes 	 */
666c52007c2SDavid Greenman 	if ((vp->v_mount->mnt_flag & MNT_NOEXEC) ||
66726f9a767SRodney W. Grimes 	    ((attr->va_mode & 0111) == 0) ||
66826f9a767SRodney W. Grimes 	    (attr->va_type != VREG)) {
66926f9a767SRodney W. Grimes 		return (EACCES);
67026f9a767SRodney W. Grimes 	}
67126f9a767SRodney W. Grimes 
67226f9a767SRodney W. Grimes 	/*
67326f9a767SRodney W. Grimes 	 * Zero length files can't be exec'd
67426f9a767SRodney W. Grimes 	 */
67526f9a767SRodney W. Grimes 	if (attr->va_size == 0)
67626f9a767SRodney W. Grimes 		return (ENOEXEC);
67726f9a767SRodney W. Grimes 
67826f9a767SRodney W. Grimes 	/*
67926f9a767SRodney W. Grimes 	 *  Check for execute permission to file based on current credentials.
68026f9a767SRodney W. Grimes 	 */
681c52007c2SDavid Greenman 	error = VOP_ACCESS(vp, VEXEC, p->p_ucred, p);
68226f9a767SRodney W. Grimes 	if (error)
68326f9a767SRodney W. Grimes 		return (error);
68426f9a767SRodney W. Grimes 
6856d5a0a8cSDavid Greenman 	/*
6866d5a0a8cSDavid Greenman 	 * Check number of open-for-writes on the file and deny execution
6876d5a0a8cSDavid Greenman 	 * if there are any.
6886d5a0a8cSDavid Greenman 	 */
6896d5a0a8cSDavid Greenman 	if (vp->v_writecount)
6906d5a0a8cSDavid Greenman 		return (ETXTBSY);
6916d5a0a8cSDavid Greenman 
6926d5a0a8cSDavid Greenman 	/*
6936d5a0a8cSDavid Greenman 	 * Call filesystem specific open routine (which does nothing in the
6946d5a0a8cSDavid Greenman 	 * general case).
6956d5a0a8cSDavid Greenman 	 */
696c52007c2SDavid Greenman 	error = VOP_OPEN(vp, FREAD, p->p_ucred, p);
69726f9a767SRodney W. Grimes 	if (error)
69826f9a767SRodney W. Grimes 		return (error);
69926f9a767SRodney W. Grimes 
70026f9a767SRodney W. Grimes 	return (0);
701df8bae1dSRodney W. Grimes }
702