xref: /freebsd/sys/kern/kern_exec.c (revision b249ce48ea5560afdcff57e72a9880b7d3132434)
19454b2d8SWarner Losh /*-
28a36da99SPedro F. Giffuni  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
38a36da99SPedro F. Giffuni  *
426f9a767SRodney W. Grimes  * Copyright (c) 1993, David Greenman
526f9a767SRodney W. Grimes  * All rights reserved.
6df8bae1dSRodney W. Grimes  *
7df8bae1dSRodney W. Grimes  * Redistribution and use in source and binary forms, with or without
8df8bae1dSRodney W. Grimes  * modification, are permitted provided that the following conditions
9df8bae1dSRodney W. Grimes  * are met:
10df8bae1dSRodney W. Grimes  * 1. Redistributions of source code must retain the above copyright
11df8bae1dSRodney W. Grimes  *    notice, this list of conditions and the following disclaimer.
12df8bae1dSRodney W. Grimes  * 2. Redistributions in binary form must reproduce the above copyright
13df8bae1dSRodney W. Grimes  *    notice, this list of conditions and the following disclaimer in the
14df8bae1dSRodney W. Grimes  *    documentation and/or other materials provided with the distribution.
15df8bae1dSRodney W. Grimes  *
1626f9a767SRodney W. Grimes  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17df8bae1dSRodney W. Grimes  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18df8bae1dSRodney W. Grimes  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
1926f9a767SRodney W. Grimes  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20df8bae1dSRodney W. Grimes  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21df8bae1dSRodney W. Grimes  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22df8bae1dSRodney W. Grimes  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23df8bae1dSRodney W. Grimes  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24df8bae1dSRodney W. Grimes  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25df8bae1dSRodney W. Grimes  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26df8bae1dSRodney W. Grimes  * SUCH DAMAGE.
27df8bae1dSRodney W. Grimes  */
28df8bae1dSRodney W. Grimes 
29677b542eSDavid E. O'Brien #include <sys/cdefs.h>
30677b542eSDavid E. O'Brien __FBSDID("$FreeBSD$");
31677b542eSDavid E. O'Brien 
3212bc222eSJonathan Anderson #include "opt_capsicum.h"
334da0d332SPeter Wemm #include "opt_hwpmc_hooks.h"
341e9b3d91SPeter Wemm #include "opt_ktrace.h"
35f8a47341SAlan Cox #include "opt_vm.h"
361e9b3d91SPeter Wemm 
37df8bae1dSRodney W. Grimes #include <sys/param.h>
3826f9a767SRodney W. Grimes #include <sys/systm.h>
3926f9a767SRodney W. Grimes #include <sys/acct.h>
40eeeaa7baSMark Johnston #include <sys/capsicum.h>
41eeeaa7baSMark Johnston #include <sys/eventhandler.h>
4226f9a767SRodney W. Grimes #include <sys/exec.h>
43eeeaa7baSMark Johnston #include <sys/fcntl.h>
44eeeaa7baSMark Johnston #include <sys/filedesc.h>
4526f9a767SRodney W. Grimes #include <sys/imgact.h>
46e1743d02SSøren Schmidt #include <sys/imgact_elf.h>
47eeeaa7baSMark Johnston #include <sys/kernel.h>
48eeeaa7baSMark Johnston #include <sys/lock.h>
49333ea485SGuido van Rooij #include <sys/malloc.h>
50ec492b13SMark Johnston #include <sys/mman.h>
51eeeaa7baSMark Johnston #include <sys/mount.h>
52eeeaa7baSMark Johnston #include <sys/mutex.h>
53eeeaa7baSMark Johnston #include <sys/namei.h>
54eeeaa7baSMark Johnston #include <sys/pioctl.h>
55acd3428bSRobert Watson #include <sys/priv.h>
56a794e791SBruce Evans #include <sys/proc.h>
578d570f64SJohn Baldwin #include <sys/ptrace.h>
586004362eSDavid Schultz #include <sys/resourcevar.h>
5989f6b863SAttilio Rao #include <sys/rwlock.h>
6044ad5475SJohn Baldwin #include <sys/sched.h>
615d217f17SJohn Birrell #include <sys/sdt.h>
6259c8bc40SAlan Cox #include <sys/sf_buf.h>
63797f2d22SPoul-Henning Kamp #include <sys/shm.h>
64eeeaa7baSMark Johnston #include <sys/signalvar.h>
65ec492b13SMark Johnston #include <sys/smp.h>
66dfa7fd1dSEdward Tomasz Napierala #include <sys/stat.h>
67eeeaa7baSMark Johnston #include <sys/syscallsubr.h>
68eeeaa7baSMark Johnston #include <sys/sysctl.h>
69eeeaa7baSMark Johnston #include <sys/sysent.h>
70eeeaa7baSMark Johnston #include <sys/sysproto.h>
71eeeaa7baSMark Johnston #include <sys/vnode.h>
72eeeaa7baSMark Johnston #include <sys/wait.h>
73c781aea8SPeter Wemm #ifdef KTRACE
74c781aea8SPeter Wemm #include <sys/ktrace.h>
75c781aea8SPeter Wemm #endif
7626f9a767SRodney W. Grimes 
7726f9a767SRodney W. Grimes #include <vm/vm.h>
78efeaf95aSDavid Greenman #include <vm/vm_param.h>
79efeaf95aSDavid Greenman #include <vm/pmap.h>
801616db3cSJohn Dyson #include <vm/vm_page.h>
81efeaf95aSDavid Greenman #include <vm/vm_map.h>
8226f9a767SRodney W. Grimes #include <vm/vm_kern.h>
83efeaf95aSDavid Greenman #include <vm/vm_extern.h>
841ebd0c59SDavid Greenman #include <vm/vm_object.h>
851616db3cSJohn Dyson #include <vm/vm_pager.h>
8626f9a767SRodney W. Grimes 
87ebccf1e3SJoseph Koshy #ifdef	HWPMC_HOOKS
88ebccf1e3SJoseph Koshy #include <sys/pmckern.h>
89ebccf1e3SJoseph Koshy #endif
90ebccf1e3SJoseph Koshy 
9126f9a767SRodney W. Grimes #include <machine/reg.h>
9226f9a767SRodney W. Grimes 
93ae1078d6SWayne Salamon #include <security/audit/audit.h>
94aed55708SRobert Watson #include <security/mac/mac_framework.h>
95ae1078d6SWayne Salamon 
965d217f17SJohn Birrell #ifdef KDTRACE_HOOKS
975d217f17SJohn Birrell #include <sys/dtrace_bsd.h>
985d217f17SJohn Birrell dtrace_execexit_func_t	dtrace_fasttrap_exec;
995d217f17SJohn Birrell #endif
1005d217f17SJohn Birrell 
1015d217f17SJohn Birrell SDT_PROVIDER_DECLARE(proc);
10236160958SMark Johnston SDT_PROBE_DEFINE1(proc, , , exec, "char *");
10336160958SMark Johnston SDT_PROBE_DEFINE1(proc, , , exec__failure, "int");
10436160958SMark Johnston SDT_PROBE_DEFINE1(proc, , , exec__success, "char *");
1055d217f17SJohn Birrell 
106b9df5231SPoul-Henning Kamp MALLOC_DEFINE(M_PARGS, "proc-args", "Process arguments");
107b9df5231SPoul-Henning Kamp 
108bcb60d52SConrad Meyer int coredump_pack_fileinfo = 1;
109bcb60d52SConrad Meyer SYSCTL_INT(_kern, OID_AUTO, coredump_pack_fileinfo, CTLFLAG_RWTUN,
110bcb60d52SConrad Meyer     &coredump_pack_fileinfo, 0,
111bcb60d52SConrad Meyer     "Enable file path packing in 'procstat -f' coredump notes");
112bcb60d52SConrad Meyer 
113e6b95927SConrad Meyer int coredump_pack_vmmapinfo = 1;
114e6b95927SConrad Meyer SYSCTL_INT(_kern, OID_AUTO, coredump_pack_vmmapinfo, CTLFLAG_RWTUN,
115e6b95927SConrad Meyer     &coredump_pack_vmmapinfo, 0,
116e6b95927SConrad Meyer     "Enable file path packing in 'procstat -v' coredump notes");
117e6b95927SConrad Meyer 
11805ba50f5SJake Burkholder static int sysctl_kern_ps_strings(SYSCTL_HANDLER_ARGS);
11905ba50f5SJake Burkholder static int sysctl_kern_usrstack(SYSCTL_HANDLER_ARGS);
1205dadd17bSJake Burkholder static int sysctl_kern_stackprot(SYSCTL_HANDLER_ARGS);
121610ecfe0SMaxim Sobolev static int do_execve(struct thread *td, struct image_args *args,
122610ecfe0SMaxim Sobolev     struct mac *mac_p);
12305ba50f5SJake Burkholder 
1249701cd40SJohn Baldwin /* XXX This should be vm_size_t. */
12553dc58f2SMateusz Guzik SYSCTL_PROC(_kern, KERN_PS_STRINGS, ps_strings, CTLTYPE_ULONG|CTLFLAG_RD|
1262fe6aeffSMariusz Zaborski     CTLFLAG_CAPRD|CTLFLAG_MPSAFE, NULL, 0, sysctl_kern_ps_strings, "LU", "");
127486bddb0SDoug Rabson 
1289701cd40SJohn Baldwin /* XXX This should be vm_size_t. */
129ff66f6a4SRobert Watson SYSCTL_PROC(_kern, KERN_USRSTACK, usrstack, CTLTYPE_ULONG|CTLFLAG_RD|
13053dc58f2SMateusz Guzik     CTLFLAG_CAPRD|CTLFLAG_MPSAFE, NULL, 0, sysctl_kern_usrstack, "LU", "");
13199ac3bc8SPeter Wemm 
13253dc58f2SMateusz Guzik SYSCTL_PROC(_kern, OID_AUTO, stackprot, CTLTYPE_INT|CTLFLAG_RD|CTLFLAG_MPSAFE,
1335dadd17bSJake Burkholder     NULL, 0, sysctl_kern_stackprot, "I", "");
1345dadd17bSJake Burkholder 
135b9df5231SPoul-Henning Kamp u_long ps_arg_cache_limit = PAGE_SIZE / 16;
136c3699b5fSPeter Wemm SYSCTL_ULONG(_kern, OID_AUTO, ps_arg_cache_limit, CTLFLAG_RW,
1379701cd40SJohn Baldwin     &ps_arg_cache_limit, 0, "");
138b9df5231SPoul-Henning Kamp 
139eda6009cSKonstantin Belousov static int disallow_high_osrel;
140eda6009cSKonstantin Belousov SYSCTL_INT(_kern, OID_AUTO, disallow_high_osrel, CTLFLAG_RW,
141eda6009cSKonstantin Belousov     &disallow_high_osrel, 0,
142eda6009cSKonstantin Belousov     "Disallow execution of binaries built for higher version of the world");
143eda6009cSKonstantin Belousov 
144878adb85SBjoern A. Zeeb static int map_at_zero = 0;
145af3b2549SHans Petter Selasky SYSCTL_INT(_security_bsd, OID_AUTO, map_at_zero, CTLFLAG_RWTUN, &map_at_zero, 0,
146878adb85SBjoern A. Zeeb     "Permit processes to map an object at virtual address 0.");
147878adb85SBjoern A. Zeeb 
14805ba50f5SJake Burkholder static int
14905ba50f5SJake Burkholder sysctl_kern_ps_strings(SYSCTL_HANDLER_ARGS)
15005ba50f5SJake Burkholder {
15105ba50f5SJake Burkholder 	struct proc *p;
152df7c361eSPeter Wemm 	int error;
15305ba50f5SJake Burkholder 
15405ba50f5SJake Burkholder 	p = curproc;
155a7bc3102SPeter Wemm #ifdef SCTL_MASK32
156a7bc3102SPeter Wemm 	if (req->flags & SCTL_MASK32) {
157df7c361eSPeter Wemm 		unsigned int val;
158df7c361eSPeter Wemm 		val = (unsigned int)p->p_sysent->sv_psstrings;
159df7c361eSPeter Wemm 		error = SYSCTL_OUT(req, &val, sizeof(val));
160df7c361eSPeter Wemm 	} else
161df7c361eSPeter Wemm #endif
162df7c361eSPeter Wemm 		error = SYSCTL_OUT(req, &p->p_sysent->sv_psstrings,
163df7c361eSPeter Wemm 		   sizeof(p->p_sysent->sv_psstrings));
164df7c361eSPeter Wemm 	return error;
16505ba50f5SJake Burkholder }
16605ba50f5SJake Burkholder 
16705ba50f5SJake Burkholder static int
16805ba50f5SJake Burkholder sysctl_kern_usrstack(SYSCTL_HANDLER_ARGS)
16905ba50f5SJake Burkholder {
17005ba50f5SJake Burkholder 	struct proc *p;
171df7c361eSPeter Wemm 	int error;
17205ba50f5SJake Burkholder 
17305ba50f5SJake Burkholder 	p = curproc;
174a7bc3102SPeter Wemm #ifdef SCTL_MASK32
175a7bc3102SPeter Wemm 	if (req->flags & SCTL_MASK32) {
176df7c361eSPeter Wemm 		unsigned int val;
177df7c361eSPeter Wemm 		val = (unsigned int)p->p_sysent->sv_usrstack;
178df7c361eSPeter Wemm 		error = SYSCTL_OUT(req, &val, sizeof(val));
179df7c361eSPeter Wemm 	} else
180df7c361eSPeter Wemm #endif
181df7c361eSPeter Wemm 		error = SYSCTL_OUT(req, &p->p_sysent->sv_usrstack,
182df7c361eSPeter Wemm 		    sizeof(p->p_sysent->sv_usrstack));
183df7c361eSPeter Wemm 	return error;
18405ba50f5SJake Burkholder }
18505ba50f5SJake Burkholder 
1865dadd17bSJake Burkholder static int
1875dadd17bSJake Burkholder sysctl_kern_stackprot(SYSCTL_HANDLER_ARGS)
1885dadd17bSJake Burkholder {
1895dadd17bSJake Burkholder 	struct proc *p;
1905dadd17bSJake Burkholder 
1915dadd17bSJake Burkholder 	p = curproc;
1925dadd17bSJake Burkholder 	return (SYSCTL_OUT(req, &p->p_sysent->sv_stackprot,
1935dadd17bSJake Burkholder 	    sizeof(p->p_sysent->sv_stackprot)));
1945dadd17bSJake Burkholder }
1955dadd17bSJake Burkholder 
19699ac3bc8SPeter Wemm /*
197aa855a59SPeter Wemm  * Each of the items is a pointer to a `const struct execsw', hence the
198aa855a59SPeter Wemm  * double pointer here.
199df8bae1dSRodney W. Grimes  */
200aa855a59SPeter Wemm static const struct execsw **execsw;
20126f9a767SRodney W. Grimes 
202ca46e90eSBruce Evans #ifndef _SYS_SYSPROTO_H_
203ca46e90eSBruce Evans struct execve_args {
204ca46e90eSBruce Evans 	char    *fname;
205ca46e90eSBruce Evans 	char    **argv;
206ca46e90eSBruce Evans 	char    **envv;
207ca46e90eSBruce Evans };
208ca46e90eSBruce Evans #endif
209ca46e90eSBruce Evans 
210ca46e90eSBruce Evans int
2117b445033SKonstantin Belousov sys_execve(struct thread *td, struct execve_args *uap)
212ca46e90eSBruce Evans {
213610ecfe0SMaxim Sobolev 	struct image_args args;
2147b445033SKonstantin Belousov 	struct vmspace *oldvmspace;
2157b445033SKonstantin Belousov 	int error;
216ca46e90eSBruce Evans 
2177b445033SKonstantin Belousov 	error = pre_execve(td, &oldvmspace);
2187b445033SKonstantin Belousov 	if (error != 0)
2197b445033SKonstantin Belousov 		return (error);
220610ecfe0SMaxim Sobolev 	error = exec_copyin_args(&args, uap->fname, UIO_USERSPACE,
221610ecfe0SMaxim Sobolev 	    uap->argv, uap->envv);
222610ecfe0SMaxim Sobolev 	if (error == 0)
223610ecfe0SMaxim Sobolev 		error = kern_execve(td, &args, NULL);
2247b445033SKonstantin Belousov 	post_execve(td, error, oldvmspace);
225610ecfe0SMaxim Sobolev 	return (error);
226ca46e90eSBruce Evans }
227ca46e90eSBruce Evans 
228ca46e90eSBruce Evans #ifndef _SYS_SYSPROTO_H_
229632dbc19SKonstantin Belousov struct fexecve_args {
230632dbc19SKonstantin Belousov 	int	fd;
231632dbc19SKonstantin Belousov 	char	**argv;
232632dbc19SKonstantin Belousov 	char	**envv;
233632dbc19SKonstantin Belousov }
234632dbc19SKonstantin Belousov #endif
235632dbc19SKonstantin Belousov int
2368451d0ddSKip Macy sys_fexecve(struct thread *td, struct fexecve_args *uap)
237632dbc19SKonstantin Belousov {
238632dbc19SKonstantin Belousov 	struct image_args args;
2397b445033SKonstantin Belousov 	struct vmspace *oldvmspace;
2407b445033SKonstantin Belousov 	int error;
241632dbc19SKonstantin Belousov 
2427b445033SKonstantin Belousov 	error = pre_execve(td, &oldvmspace);
2437b445033SKonstantin Belousov 	if (error != 0)
2447b445033SKonstantin Belousov 		return (error);
245632dbc19SKonstantin Belousov 	error = exec_copyin_args(&args, NULL, UIO_SYSSPACE,
246632dbc19SKonstantin Belousov 	    uap->argv, uap->envv);
247632dbc19SKonstantin Belousov 	if (error == 0) {
248632dbc19SKonstantin Belousov 		args.fd = uap->fd;
249632dbc19SKonstantin Belousov 		error = kern_execve(td, &args, NULL);
250632dbc19SKonstantin Belousov 	}
2517b445033SKonstantin Belousov 	post_execve(td, error, oldvmspace);
252632dbc19SKonstantin Belousov 	return (error);
253632dbc19SKonstantin Belousov }
254632dbc19SKonstantin Belousov 
255632dbc19SKonstantin Belousov #ifndef _SYS_SYSPROTO_H_
256ca46e90eSBruce Evans struct __mac_execve_args {
257ca46e90eSBruce Evans 	char	*fname;
258ca46e90eSBruce Evans 	char	**argv;
259ca46e90eSBruce Evans 	char	**envv;
260ca46e90eSBruce Evans 	struct mac	*mac_p;
261ca46e90eSBruce Evans };
262ca46e90eSBruce Evans #endif
263ca46e90eSBruce Evans 
264ca46e90eSBruce Evans int
2657b445033SKonstantin Belousov sys___mac_execve(struct thread *td, struct __mac_execve_args *uap)
266ca46e90eSBruce Evans {
267ca46e90eSBruce Evans #ifdef MAC
268610ecfe0SMaxim Sobolev 	struct image_args args;
2697b445033SKonstantin Belousov 	struct vmspace *oldvmspace;
2707b445033SKonstantin Belousov 	int error;
271610ecfe0SMaxim Sobolev 
2727b445033SKonstantin Belousov 	error = pre_execve(td, &oldvmspace);
2737b445033SKonstantin Belousov 	if (error != 0)
2747b445033SKonstantin Belousov 		return (error);
275610ecfe0SMaxim Sobolev 	error = exec_copyin_args(&args, uap->fname, UIO_USERSPACE,
276610ecfe0SMaxim Sobolev 	    uap->argv, uap->envv);
277610ecfe0SMaxim Sobolev 	if (error == 0)
278610ecfe0SMaxim Sobolev 		error = kern_execve(td, &args, uap->mac_p);
2797b445033SKonstantin Belousov 	post_execve(td, error, oldvmspace);
280610ecfe0SMaxim Sobolev 	return (error);
281ca46e90eSBruce Evans #else
282ca46e90eSBruce Evans 	return (ENOSYS);
283ca46e90eSBruce Evans #endif
284ca46e90eSBruce Evans }
285ca46e90eSBruce Evans 
28684e0b075SDavid Xu int
2877b445033SKonstantin Belousov pre_execve(struct thread *td, struct vmspace **oldvmspace)
288906ac69dSDavid Xu {
2897b445033SKonstantin Belousov 	struct proc *p;
290906ac69dSDavid Xu 	int error;
291906ac69dSDavid Xu 
2927b445033SKonstantin Belousov 	KASSERT(td == curthread, ("non-current thread %p", td));
2937b445033SKonstantin Belousov 	error = 0;
2947b445033SKonstantin Belousov 	p = td->td_proc;
2957b445033SKonstantin Belousov 	if ((p->p_flag & P_HADTHREADS) != 0) {
296906ac69dSDavid Xu 		PROC_LOCK(p);
2977b445033SKonstantin Belousov 		if (thread_single(p, SINGLE_BOUNDARY) != 0)
2987b445033SKonstantin Belousov 			error = ERESTART;
299906ac69dSDavid Xu 		PROC_UNLOCK(p);
300906ac69dSDavid Xu 	}
3017b445033SKonstantin Belousov 	KASSERT(error != 0 || (td->td_pflags & TDP_EXECVMSPC) == 0,
3027b445033SKonstantin Belousov 	    ("nested execve"));
3037b445033SKonstantin Belousov 	*oldvmspace = p->p_vmspace;
3047b445033SKonstantin Belousov 	return (error);
3057b445033SKonstantin Belousov }
306906ac69dSDavid Xu 
3077b445033SKonstantin Belousov void
3087b445033SKonstantin Belousov post_execve(struct thread *td, int error, struct vmspace *oldvmspace)
3097b445033SKonstantin Belousov {
3107b445033SKonstantin Belousov 	struct proc *p;
311906ac69dSDavid Xu 
3127b445033SKonstantin Belousov 	KASSERT(td == curthread, ("non-current thread %p", td));
3137b445033SKonstantin Belousov 	p = td->td_proc;
3147b445033SKonstantin Belousov 	if ((p->p_flag & P_HADTHREADS) != 0) {
315906ac69dSDavid Xu 		PROC_LOCK(p);
316906ac69dSDavid Xu 		/*
317906ac69dSDavid Xu 		 * If success, we upgrade to SINGLE_EXIT state to
318906ac69dSDavid Xu 		 * force other threads to suicide.
319906ac69dSDavid Xu 		 */
320814629ddSEd Schouten 		if (error == EJUSTRETURN)
3216ddcc233SKonstantin Belousov 			thread_single(p, SINGLE_EXIT);
322906ac69dSDavid Xu 		else
3236ddcc233SKonstantin Belousov 			thread_single_end(p, SINGLE_BOUNDARY);
324906ac69dSDavid Xu 		PROC_UNLOCK(p);
325906ac69dSDavid Xu 	}
3267032434eSKonstantin Belousov 	if ((td->td_pflags & TDP_EXECVMSPC) != 0) {
3277b445033SKonstantin Belousov 		KASSERT(p->p_vmspace != oldvmspace,
3287032434eSKonstantin Belousov 		    ("oldvmspace still used"));
3297032434eSKonstantin Belousov 		vmspace_free(oldvmspace);
3307032434eSKonstantin Belousov 		td->td_pflags &= ~TDP_EXECVMSPC;
3317032434eSKonstantin Belousov 	}
3327b445033SKonstantin Belousov }
333906ac69dSDavid Xu 
3347b445033SKonstantin Belousov /*
3357b445033SKonstantin Belousov  * XXX: kern_execve has the astonishing property of not always returning to
3367b445033SKonstantin Belousov  * the caller.  If sufficiently bad things happen during the call to
3377b445033SKonstantin Belousov  * do_execve(), it can end up calling exit1(); as a result, callers must
3387b445033SKonstantin Belousov  * avoid doing anything which they might need to undo (e.g., allocating
3397b445033SKonstantin Belousov  * memory).
3407b445033SKonstantin Belousov  */
3417b445033SKonstantin Belousov int
3427b445033SKonstantin Belousov kern_execve(struct thread *td, struct image_args *args, struct mac *mac_p)
3437b445033SKonstantin Belousov {
3447b445033SKonstantin Belousov 
3457b445033SKonstantin Belousov 	AUDIT_ARG_ARGV(args->begin_argv, args->argc,
346f373437aSBrooks Davis 	    exec_args_get_begin_envv(args) - args->begin_argv);
347f373437aSBrooks Davis 	AUDIT_ARG_ENVV(exec_args_get_begin_envv(args), args->envc,
348f373437aSBrooks Davis 	    args->endp - exec_args_get_begin_envv(args));
3497b445033SKonstantin Belousov 	return (do_execve(td, args, mac_p));
350906ac69dSDavid Xu }
351906ac69dSDavid Xu 
35226f9a767SRodney W. Grimes /*
353450ffb44SRobert Watson  * In-kernel implementation of execve().  All arguments are assumed to be
354450ffb44SRobert Watson  * userspace pointers from the passed thread.
35526f9a767SRodney W. Grimes  */
356450ffb44SRobert Watson static int
3573e85b721SEd Maste do_execve(struct thread *td, struct image_args *args, struct mac *mac_p)
358df8bae1dSRodney W. Grimes {
359b40ce416SJulian Elischer 	struct proc *p = td->td_proc;
36069c9eff8SEd Schouten 	struct nameidata nd;
361881010f0SBryan Drewery 	struct ucred *oldcred;
362350d5181SMateusz Guzik 	struct uidinfo *euip = NULL;
36331174518SJohn Baldwin 	uintptr_t stack_base;
364c52007c2SDavid Greenman 	struct image_params image_params, *imgp;
3659f5c1d19SDiomidis Spinellis 	struct vattr attr;
3664d77a549SAlfred Perlstein 	int (*img_first)(struct image_params *);
36769be5db9SAlfred Perlstein 	struct pargs *oldargs = NULL, *newargs = NULL;
368cda68844SMateusz Guzik 	struct sigacts *oldsigacts = NULL, *newsigacts = NULL;
3696c84de02SJohn Baldwin #ifdef KTRACE
3706c84de02SJohn Baldwin 	struct vnode *tracevp = NULL;
371a5881ea5SJohn Baldwin 	struct ucred *tracecred = NULL;
3726c84de02SJohn Baldwin #endif
37361617058SMateusz Guzik 	struct vnode *oldtextvp = NULL, *newtextvp;
374d06c0d4dSRobert Watson 	int credential_changing;
375ccafe7ebSRobert Watson #ifdef MAC
3766356dba0SRobert Watson 	struct label *interpvplabel = NULL;
377eca8a663SRobert Watson 	int will_transition;
378ccafe7ebSRobert Watson #endif
37915139246SJoseph Koshy #ifdef HWPMC_HOOKS
38015139246SJoseph Koshy 	struct pmckern_procexec pe;
38115139246SJoseph Koshy #endif
38201a2b567SKonstantin Belousov 	int error, i, orig_osrel;
38301a2b567SKonstantin Belousov 	uint32_t orig_fctl0;
384632dbc19SKonstantin Belousov 	static const char fexecv_proc_title[] = "(fexecv)";
38526f9a767SRodney W. Grimes 
386c52007c2SDavid Greenman 	imgp = &image_params;
387df8bae1dSRodney W. Grimes 
3889ca45e81SDag-Erling Smørgrav 	/*
3899ca45e81SDag-Erling Smørgrav 	 * Lock the process and set the P_INEXEC flag to indicate that
3909ca45e81SDag-Erling Smørgrav 	 * it should be left alone until we're done here.  This is
3919ca45e81SDag-Erling Smørgrav 	 * necessary to avoid race conditions - e.g. in ptrace() -
3929ca45e81SDag-Erling Smørgrav 	 * that might allow a local user to illicitly obtain elevated
3939ca45e81SDag-Erling Smørgrav 	 * privileges.
3949ca45e81SDag-Erling Smørgrav 	 */
3959ca45e81SDag-Erling Smørgrav 	PROC_LOCK(p);
3969ca45e81SDag-Erling Smørgrav 	KASSERT((p->p_flag & P_INEXEC) == 0,
39791f91617SDavid E. O'Brien 	    ("%s(): process already has P_INEXEC flag", __func__));
3989ca45e81SDag-Erling Smørgrav 	p->p_flag |= P_INEXEC;
3999ca45e81SDag-Erling Smørgrav 	PROC_UNLOCK(p);
4009ca45e81SDag-Erling Smørgrav 
401df8bae1dSRodney W. Grimes 	/*
402c52007c2SDavid Greenman 	 * Initialize part of the common data
403df8bae1dSRodney W. Grimes 	 */
4048e572983SMateusz Guzik 	bzero(imgp, sizeof(*imgp));
405c52007c2SDavid Greenman 	imgp->proc = p;
406c52007c2SDavid Greenman 	imgp->attr = &attr;
407610ecfe0SMaxim Sobolev 	imgp->args = args;
408881010f0SBryan Drewery 	oldcred = p->p_ucred;
40901a2b567SKonstantin Belousov 	orig_osrel = p->p_osrel;
41001a2b567SKonstantin Belousov 	orig_fctl0 = p->p_fctl0;
41126f9a767SRodney W. Grimes 
412670cb89bSRobert Watson #ifdef MAC
413eca8a663SRobert Watson 	error = mac_execve_enter(imgp, mac_p);
414532c491bSJeff Roberson 	if (error)
415670cb89bSRobert Watson 		goto exec_fail;
416670cb89bSRobert Watson #endif
417670cb89bSRobert Watson 
41826f9a767SRodney W. Grimes 	/*
41926f9a767SRodney W. Grimes 	 * Translate the file name. namei() returns a vnode pointer
420e3043798SPedro F. Giffuni 	 *	in ni_vp among other things.
421ae1078d6SWayne Salamon 	 *
422ae1078d6SWayne Salamon 	 * XXXAUDIT: It would be desirable to also audit the name of the
423ae1078d6SWayne Salamon 	 * interpreter if this is an interpreted binary.
42426f9a767SRodney W. Grimes 	 */
425632dbc19SKonstantin Belousov 	if (args->fname != NULL) {
42678022527SKonstantin Belousov 		NDINIT(&nd, LOOKUP, ISOPEN | LOCKLEAF | LOCKSHARED | FOLLOW |
42778022527SKonstantin Belousov 		    SAVENAME | AUDITVNODE1, UIO_SYSSPACE, args->fname, td);
428632dbc19SKonstantin Belousov 	}
42926f9a767SRodney W. Grimes 
43036160958SMark Johnston 	SDT_PROBE1(proc, , , exec, args->fname);
431e506f34bSCraig Rodrigues 
43226f9a767SRodney W. Grimes interpret:
433632dbc19SKonstantin Belousov 	if (args->fname != NULL) {
43412bc222eSJonathan Anderson #ifdef CAPABILITY_MODE
43512bc222eSJonathan Anderson 		/*
43612bc222eSJonathan Anderson 		 * While capability mode can't reach this point via direct
43712bc222eSJonathan Anderson 		 * path arguments to execve(), we also don't allow
43812bc222eSJonathan Anderson 		 * interpreters to be used in capability mode (for now).
43912bc222eSJonathan Anderson 		 * Catch indirect lookups and return a permissions error.
44012bc222eSJonathan Anderson 		 */
44112bc222eSJonathan Anderson 		if (IN_CAPABILITY_MODE(td)) {
44212bc222eSJonathan Anderson 			error = ECAPMODE;
44312bc222eSJonathan Anderson 			goto exec_fail;
44412bc222eSJonathan Anderson 		}
44512bc222eSJonathan Anderson #endif
44669c9eff8SEd Schouten 		error = namei(&nd);
447610ecfe0SMaxim Sobolev 		if (error)
44826f9a767SRodney W. Grimes 			goto exec_fail;
44926f9a767SRodney W. Grimes 
45061617058SMateusz Guzik 		newtextvp = nd.ni_vp;
45161617058SMateusz Guzik 		imgp->vp = newtextvp;
452632dbc19SKonstantin Belousov 	} else {
45314961ba7SRobert Watson 		AUDIT_ARG_FD(args->fd);
454a9d2f8d8SRobert Watson 		/*
455c8e781f6SPawel Jakub Dawidek 		 * Descriptors opened only with O_EXEC or O_RDONLY are allowed.
456a9d2f8d8SRobert Watson 		 */
457cbd92ce6SMatt Macy 		error = fgetvp_exec(td, args->fd, &cap_fexecve_rights, &newtextvp);
458632dbc19SKonstantin Belousov 		if (error)
459632dbc19SKonstantin Belousov 			goto exec_fail;
46078022527SKonstantin Belousov 		vn_lock(newtextvp, LK_SHARED | LK_RETRY);
46161617058SMateusz Guzik 		AUDIT_ARG_VNODE1(newtextvp);
46261617058SMateusz Guzik 		imgp->vp = newtextvp;
463632dbc19SKonstantin Belousov 	}
46426f9a767SRodney W. Grimes 
46526f9a767SRodney W. Grimes 	/*
46678022527SKonstantin Belousov 	 * Check file permissions.  Also 'opens' file and sets its vnode to
46778022527SKonstantin Belousov 	 * text mode.
4689022e4adSDavid Greenman 	 */
469c52007c2SDavid Greenman 	error = exec_check_permissions(imgp);
470619eb6e5SJeff Roberson 	if (error)
47126f9a767SRodney W. Grimes 		goto exec_fail_dealloc;
472619eb6e5SJeff Roberson 
4738516dd18SPoul-Henning Kamp 	imgp->object = imgp->vp->v_object;
4748516dd18SPoul-Henning Kamp 	if (imgp->object != NULL)
4750b2ed1aeSJeff Roberson 		vm_object_reference(imgp->object);
47626f9a767SRodney W. Grimes 
4771616db3cSJohn Dyson 	error = exec_map_first_page(imgp);
4786d5a0a8cSDavid Greenman 	if (error)
47926f9a767SRodney W. Grimes 		goto exec_fail_dealloc;
48026f9a767SRodney W. Grimes 
481f231de47SKonstantin Belousov 	imgp->proc->p_osrel = 0;
482f5cf7589SKonstantin Belousov 	imgp->proc->p_fctl0 = 0;
483881010f0SBryan Drewery 
484881010f0SBryan Drewery 	/*
485881010f0SBryan Drewery 	 * Implement image setuid/setgid.
486881010f0SBryan Drewery 	 *
487881010f0SBryan Drewery 	 * Determine new credentials before attempting image activators
488881010f0SBryan Drewery 	 * so that it can be used by process_exec handlers to determine
489881010f0SBryan Drewery 	 * credential/setid changes.
490881010f0SBryan Drewery 	 *
491881010f0SBryan Drewery 	 * Don't honor setuid/setgid if the filesystem prohibits it or if
492881010f0SBryan Drewery 	 * the process is being traced.
493881010f0SBryan Drewery 	 *
494881010f0SBryan Drewery 	 * We disable setuid/setgid/etc in capability mode on the basis
495881010f0SBryan Drewery 	 * that most setugid applications are not written with that
496881010f0SBryan Drewery 	 * environment in mind, and will therefore almost certainly operate
497881010f0SBryan Drewery 	 * incorrectly. In principle there's no reason that setugid
498881010f0SBryan Drewery 	 * applications might not be useful in capability mode, so we may want
499881010f0SBryan Drewery 	 * to reconsider this conservative design choice in the future.
500881010f0SBryan Drewery 	 *
501881010f0SBryan Drewery 	 * XXXMAC: For the time being, use NOSUID to also prohibit
502881010f0SBryan Drewery 	 * transitions on the file system.
503881010f0SBryan Drewery 	 */
504881010f0SBryan Drewery 	credential_changing = 0;
505881010f0SBryan Drewery 	credential_changing |= (attr.va_mode & S_ISUID) &&
506881010f0SBryan Drewery 	    oldcred->cr_uid != attr.va_uid;
507881010f0SBryan Drewery 	credential_changing |= (attr.va_mode & S_ISGID) &&
508881010f0SBryan Drewery 	    oldcred->cr_gid != attr.va_gid;
509881010f0SBryan Drewery #ifdef MAC
510881010f0SBryan Drewery 	will_transition = mac_vnode_execve_will_transition(oldcred, imgp->vp,
511881010f0SBryan Drewery 	    interpvplabel, imgp);
512881010f0SBryan Drewery 	credential_changing |= will_transition;
513881010f0SBryan Drewery #endif
514881010f0SBryan Drewery 
5151302eea7SKonstantin Belousov 	/* Don't inherit PROC_PDEATHSIG_CTL value if setuid/setgid. */
516b9408863SKonstantin Belousov 	if (credential_changing)
517b9408863SKonstantin Belousov 		imgp->proc->p_pdeathsig = 0;
518b9408863SKonstantin Belousov 
519881010f0SBryan Drewery 	if (credential_changing &&
520881010f0SBryan Drewery #ifdef CAPABILITY_MODE
521881010f0SBryan Drewery 	    ((oldcred->cr_flags & CRED_FLAG_CAPMODE) == 0) &&
522881010f0SBryan Drewery #endif
523881010f0SBryan Drewery 	    (imgp->vp->v_mount->mnt_flag & MNT_NOSUID) == 0 &&
524881010f0SBryan Drewery 	    (p->p_flag & P_TRACED) == 0) {
525881010f0SBryan Drewery 		imgp->credential_setid = true;
526*b249ce48SMateusz Guzik 		VOP_UNLOCK(imgp->vp);
527881010f0SBryan Drewery 		imgp->newcred = crdup(oldcred);
528881010f0SBryan Drewery 		if (attr.va_mode & S_ISUID) {
529881010f0SBryan Drewery 			euip = uifind(attr.va_uid);
530881010f0SBryan Drewery 			change_euid(imgp->newcred, euip);
531881010f0SBryan Drewery 		}
5321040254bSKonstantin Belousov 		vn_lock(imgp->vp, LK_SHARED | LK_RETRY);
533881010f0SBryan Drewery 		if (attr.va_mode & S_ISGID)
534881010f0SBryan Drewery 			change_egid(imgp->newcred, attr.va_gid);
535881010f0SBryan Drewery 		/*
536881010f0SBryan Drewery 		 * Implement correct POSIX saved-id behavior.
537881010f0SBryan Drewery 		 *
538881010f0SBryan Drewery 		 * XXXMAC: Note that the current logic will save the
539881010f0SBryan Drewery 		 * uid and gid if a MAC domain transition occurs, even
540881010f0SBryan Drewery 		 * though maybe it shouldn't.
541881010f0SBryan Drewery 		 */
542881010f0SBryan Drewery 		change_svuid(imgp->newcred, imgp->newcred->cr_uid);
543881010f0SBryan Drewery 		change_svgid(imgp->newcred, imgp->newcred->cr_gid);
544881010f0SBryan Drewery 	} else {
545881010f0SBryan Drewery 		/*
546881010f0SBryan Drewery 		 * Implement correct POSIX saved-id behavior.
547881010f0SBryan Drewery 		 *
548881010f0SBryan Drewery 		 * XXX: It's not clear that the existing behavior is
549881010f0SBryan Drewery 		 * POSIX-compliant.  A number of sources indicate that the
550881010f0SBryan Drewery 		 * saved uid/gid should only be updated if the new ruid is
551881010f0SBryan Drewery 		 * not equal to the old ruid, or the new euid is not equal
552881010f0SBryan Drewery 		 * to the old euid and the new euid is not equal to the old
553881010f0SBryan Drewery 		 * ruid.  The FreeBSD code always updates the saved uid/gid.
554881010f0SBryan Drewery 		 * Also, this code uses the new (replaced) euid and egid as
555881010f0SBryan Drewery 		 * the source, which may or may not be the right ones to use.
556881010f0SBryan Drewery 		 */
557881010f0SBryan Drewery 		if (oldcred->cr_svuid != oldcred->cr_uid ||
558881010f0SBryan Drewery 		    oldcred->cr_svgid != oldcred->cr_gid) {
559*b249ce48SMateusz Guzik 			VOP_UNLOCK(imgp->vp);
560881010f0SBryan Drewery 			imgp->newcred = crdup(oldcred);
5611040254bSKonstantin Belousov 			vn_lock(imgp->vp, LK_SHARED | LK_RETRY);
562881010f0SBryan Drewery 			change_svuid(imgp->newcred, imgp->newcred->cr_uid);
563881010f0SBryan Drewery 			change_svgid(imgp->newcred, imgp->newcred->cr_gid);
564881010f0SBryan Drewery 		}
565881010f0SBryan Drewery 	}
566881010f0SBryan Drewery 	/* The new credentials are installed into the process later. */
567881010f0SBryan Drewery 
56826f9a767SRodney W. Grimes 	/*
5691afd78b3SBryan Drewery 	 * Do the best to calculate the full path to the image file.
5701afd78b3SBryan Drewery 	 */
5711afd78b3SBryan Drewery 	if (args->fname != NULL && args->fname[0] == '/')
5721afd78b3SBryan Drewery 		imgp->execpath = args->fname;
5731afd78b3SBryan Drewery 	else {
574*b249ce48SMateusz Guzik 		VOP_UNLOCK(imgp->vp);
5751afd78b3SBryan Drewery 		if (vn_fullpath(td, imgp->vp, &imgp->execpath,
5761afd78b3SBryan Drewery 		    &imgp->freepath) != 0)
5771afd78b3SBryan Drewery 			imgp->execpath = args->fname;
5781040254bSKonstantin Belousov 		vn_lock(imgp->vp, LK_SHARED | LK_RETRY);
5791afd78b3SBryan Drewery 	}
5801afd78b3SBryan Drewery 
5811afd78b3SBryan Drewery 	/*
582d323ddf3SMatthew Dillon 	 *	If the current process has a special image activator it
583d323ddf3SMatthew Dillon 	 *	wants to try first, call it.   For example, emulating shell
584d323ddf3SMatthew Dillon 	 *	scripts differently.
58526f9a767SRodney W. Grimes 	 */
586d323ddf3SMatthew Dillon 	error = -1;
587d323ddf3SMatthew Dillon 	if ((img_first = imgp->proc->p_sysent->sv_imgact_try) != NULL)
588d323ddf3SMatthew Dillon 		error = img_first(imgp);
589d323ddf3SMatthew Dillon 
590d323ddf3SMatthew Dillon 	/*
591d323ddf3SMatthew Dillon 	 *	Loop through the list of image activators, calling each one.
592d323ddf3SMatthew Dillon 	 *	An activator returns -1 if there is no match, 0 on success,
593d323ddf3SMatthew Dillon 	 *	and an error otherwise.
594d323ddf3SMatthew Dillon 	 */
595d323ddf3SMatthew Dillon 	for (i = 0; error == -1 && execsw[i]; ++i) {
596d323ddf3SMatthew Dillon 		if (execsw[i]->ex_imgact == NULL ||
597d323ddf3SMatthew Dillon 		    execsw[i]->ex_imgact == img_first) {
598d323ddf3SMatthew Dillon 			continue;
599d323ddf3SMatthew Dillon 		}
600c52007c2SDavid Greenman 		error = (*execsw[i]->ex_imgact)(imgp);
601d323ddf3SMatthew Dillon 	}
602d323ddf3SMatthew Dillon 
603d323ddf3SMatthew Dillon 	if (error) {
60478022527SKonstantin Belousov 		if (error == -1)
605d323ddf3SMatthew Dillon 			error = ENOEXEC;
60626f9a767SRodney W. Grimes 		goto exec_fail_dealloc;
607d323ddf3SMatthew Dillon 	}
608d323ddf3SMatthew Dillon 
609d323ddf3SMatthew Dillon 	/*
610d323ddf3SMatthew Dillon 	 * Special interpreter operation, cleanup and loop up to try to
611d323ddf3SMatthew Dillon 	 * activate the interpreter.
612d323ddf3SMatthew Dillon 	 */
613c52007c2SDavid Greenman 	if (imgp->interpreted) {
6141616db3cSJohn Dyson 		exec_unmap_first_page(imgp);
615619eb6e5SJeff Roberson 		/*
61678022527SKonstantin Belousov 		 * The text reference needs to be removed for scripts.
61778022527SKonstantin Belousov 		 * There is a short period before we determine that
61878022527SKonstantin Belousov 		 * something is a script where text reference is active.
61978022527SKonstantin Belousov 		 * The vnode lock is held over this entire period
62078022527SKonstantin Belousov 		 * so nothing should illegitimately be blocked.
621619eb6e5SJeff Roberson 		 */
6221c36b728SKonstantin Belousov 		MPASS(imgp->textset);
6231c36b728SKonstantin Belousov 		VOP_UNSET_TEXT_CHECKED(newtextvp);
6241c36b728SKonstantin Belousov 		imgp->textset = false;
625762e6b85SEivind Eklund 		/* free name buffer and old vnode */
626632dbc19SKonstantin Belousov 		if (args->fname != NULL)
62769c9eff8SEd Schouten 			NDFREE(&nd, NDF_ONLY_PNBUF);
628670cb89bSRobert Watson #ifdef MAC
62961617058SMateusz Guzik 		mac_execve_interpreter_enter(newtextvp, &interpvplabel);
630670cb89bSRobert Watson #endif
6319a75ea23SKonstantin Belousov 		if (imgp->opened) {
63261617058SMateusz Guzik 			VOP_CLOSE(newtextvp, FREAD, td->td_ucred, td);
6339a75ea23SKonstantin Belousov 			imgp->opened = 0;
6349a75ea23SKonstantin Belousov 		}
63561617058SMateusz Guzik 		vput(newtextvp);
6360b2ed1aeSJeff Roberson 		vm_object_deallocate(imgp->object);
6370b2ed1aeSJeff Roberson 		imgp->object = NULL;
638881010f0SBryan Drewery 		imgp->credential_setid = false;
639881010f0SBryan Drewery 		if (imgp->newcred != NULL) {
640881010f0SBryan Drewery 			crfree(imgp->newcred);
641881010f0SBryan Drewery 			imgp->newcred = NULL;
642881010f0SBryan Drewery 		}
6431afd78b3SBryan Drewery 		imgp->execpath = NULL;
6441afd78b3SBryan Drewery 		free(imgp->freepath, M_TEMP);
6451afd78b3SBryan Drewery 		imgp->freepath = NULL;
64626f9a767SRodney W. Grimes 		/* set new name to that of the interpreter */
647f422bc30SJohn Baldwin 		NDINIT(&nd, LOOKUP, ISOPEN | LOCKLEAF | FOLLOW | SAVENAME,
648b40ce416SJulian Elischer 		    UIO_SYSSPACE, imgp->interpreter_name, td);
649632dbc19SKonstantin Belousov 		args->fname = imgp->interpreter_name;
65026f9a767SRodney W. Grimes 		goto interpret;
65126f9a767SRodney W. Grimes 	}
65226f9a767SRodney W. Grimes 
65326f9a767SRodney W. Grimes 	/*
654ded7d39cSChristian S.J. Peron 	 * NB: We unlock the vnode here because it is believed that none
655ded7d39cSChristian S.J. Peron 	 * of the sv_copyout_strings/sv_fixup operations require the vnode.
656ded7d39cSChristian S.J. Peron 	 */
657*b249ce48SMateusz Guzik 	VOP_UNLOCK(imgp->vp);
6583ff06357SKonstantin Belousov 
659eda6009cSKonstantin Belousov 	if (disallow_high_osrel &&
660eda6009cSKonstantin Belousov 	    P_OSREL_MAJOR(p->p_osrel) > P_OSREL_MAJOR(__FreeBSD_version)) {
661eda6009cSKonstantin Belousov 		error = ENOEXEC;
662eda6009cSKonstantin Belousov 		uprintf("Osrel %d for image %s too high\n", p->p_osrel,
663eda6009cSKonstantin Belousov 		    imgp->execpath != NULL ? imgp->execpath : "<unresolved>");
664eda6009cSKonstantin Belousov 		vn_lock(imgp->vp, LK_SHARED | LK_RETRY);
665eda6009cSKonstantin Belousov 		goto exec_fail_dealloc;
666eda6009cSKonstantin Belousov 	}
667eda6009cSKonstantin Belousov 
66839f5ebb7SEd Schouten 	/* ABI enforces the use of Capsicum. Switch into capabilities mode. */
66939f5ebb7SEd Schouten 	if (SV_PROC_FLAG(p, SV_CAPSICUM))
67039f5ebb7SEd Schouten 		sys_cap_enter(td, NULL);
67139f5ebb7SEd Schouten 
672ded7d39cSChristian S.J. Peron 	/*
67391ff2d48SEdward Tomasz Napierala 	 * Copy out strings (args and env) and initialize stack base.
67426f9a767SRodney W. Grimes 	 */
67503b0d68cSJohn Baldwin 	error = (*p->p_sysent->sv_copyout_strings)(imgp, &stack_base);
67603b0d68cSJohn Baldwin 	if (error != 0) {
67703b0d68cSJohn Baldwin 		vn_lock(imgp->vp, LK_SHARED | LK_RETRY);
67803b0d68cSJohn Baldwin 		goto exec_fail_dealloc;
67903b0d68cSJohn Baldwin 	}
68026f9a767SRodney W. Grimes 
68126f9a767SRodney W. Grimes 	/*
68291ff2d48SEdward Tomasz Napierala 	 * Stack setup.
68326f9a767SRodney W. Grimes 	 */
6845f77b8a8SBrooks Davis 	error = (*p->p_sysent->sv_fixup)(&stack_base, imgp);
6856f26dd50SKonstantin Belousov 	if (error != 0) {
6866f26dd50SKonstantin Belousov 		vn_lock(imgp->vp, LK_SHARED | LK_RETRY);
6875f77b8a8SBrooks Davis 		goto exec_fail_dealloc;
6886f26dd50SKonstantin Belousov 	}
68926f9a767SRodney W. Grimes 
690457f7e23SEd Schouten 	if (args->fdp != NULL) {
691457f7e23SEd Schouten 		/* Install a brand new file descriptor table. */
692457f7e23SEd Schouten 		fdinstall_remapped(td, args->fdp);
693457f7e23SEd Schouten 		args->fdp = NULL;
694457f7e23SEd Schouten 	} else {
695a78e8d2aSDavid Greenman 		/*
696457f7e23SEd Schouten 		 * Keep on using the existing file descriptor table. For
697457f7e23SEd Schouten 		 * security and other reasons, the file descriptor table
698457f7e23SEd Schouten 		 * cannot be shared after an exec.
699a78e8d2aSDavid Greenman 		 */
700b9d32c36SMateusz Guzik 		fdunshare(td);
701b0bc0cadSMateusz Guzik 		/* close files on exec */
702b0bc0cadSMateusz Guzik 		fdcloseexec(td);
703457f7e23SEd Schouten 	}
704a78e8d2aSDavid Greenman 
705333ea485SGuido van Rooij 	/*
7069b3b1c5fSJohn Baldwin 	 * Malloc things before we need locks.
7079b3b1c5fSJohn Baldwin 	 */
708f373437aSBrooks Davis 	i = exec_args_get_begin_envv(imgp->args) - imgp->args->begin_argv;
7095997cae9SDon Lewis 	/* Cache arguments if they fit inside our allowance */
7105997cae9SDon Lewis 	if (ps_arg_cache_limit >= i + sizeof(struct pargs)) {
7119b3b1c5fSJohn Baldwin 		newargs = pargs_alloc(i);
7125997cae9SDon Lewis 		bcopy(imgp->args->begin_argv, newargs->ar_args, i);
7135997cae9SDon Lewis 	}
7149b3b1c5fSJohn Baldwin 
7159b3b1c5fSJohn Baldwin 	/*
716333ea485SGuido van Rooij 	 * For security and other reasons, signal handlers cannot
7178688bb93SJohn Baldwin 	 * be shared after an exec. The new process gets a copy of the old
718b2c3fa70SDima Dorfman 	 * handlers. In execsigs(), the new process will have its signals
719333ea485SGuido van Rooij 	 * reset.
720333ea485SGuido van Rooij 	 */
72190af4afaSJohn Baldwin 	if (sigacts_shared(p->p_sigacts)) {
72290af4afaSJohn Baldwin 		oldsigacts = p->p_sigacts;
72390af4afaSJohn Baldwin 		newsigacts = sigacts_alloc();
72490af4afaSJohn Baldwin 		sigacts_copy(newsigacts, oldsigacts);
725a6bad85eSMateusz Guzik 	}
726333ea485SGuido van Rooij 
727cda68844SMateusz Guzik 	vn_lock(imgp->vp, LK_SHARED | LK_RETRY);
728cda68844SMateusz Guzik 
729d00c8ea4SMateusz Guzik 	PROC_LOCK(p);
730d00c8ea4SMateusz Guzik 	if (oldsigacts)
731d00c8ea4SMateusz Guzik 		p->p_sigacts = newsigacts;
732fdf4e8b3SWarner Losh 	/* Stop profiling */
733fdf4e8b3SWarner Losh 	stopprofclock(p);
734fdf4e8b3SWarner Losh 
73526f9a767SRodney W. Grimes 	/* reset caught signals */
73626f9a767SRodney W. Grimes 	execsigs(p);
73726f9a767SRodney W. Grimes 
73826f9a767SRodney W. Grimes 	/* name this process - nameiexec(p, ndp) */
7395ca4819dSJohn Baldwin 	bzero(p->p_comm, sizeof(p->p_comm));
7405ca4819dSJohn Baldwin 	if (args->fname)
7415ca4819dSJohn Baldwin 		bcopy(nd.ni_cnd.cn_nameptr, p->p_comm,
7425ca4819dSJohn Baldwin 		    min(nd.ni_cnd.cn_namelen, MAXCOMLEN));
74361617058SMateusz Guzik 	else if (vn_commname(newtextvp, p->p_comm, sizeof(p->p_comm)) != 0)
7445ca4819dSJohn Baldwin 		bcopy(fexecv_proc_title, p->p_comm, sizeof(fexecv_proc_title));
745ca081fdbSJulian Elischer 	bcopy(p->p_comm, td->td_name, sizeof(td->td_name));
74644ad5475SJohn Baldwin #ifdef KTR
74744ad5475SJohn Baldwin 	sched_clear_tdname(td);
74844ad5475SJohn Baldwin #endif
74926f9a767SRodney W. Grimes 
75026f9a767SRodney W. Grimes 	/*
75124b34f09SSujal Patel 	 * mark as execed, wakeup the process that vforked (if any) and tell
752dc733423SDag-Erling Smørgrav 	 * it that it now has its own resources back
75326f9a767SRodney W. Grimes 	 */
75426f9a767SRodney W. Grimes 	p->p_flag |= P_EXEC;
755677258f7SKonstantin Belousov 	if ((p->p_flag2 & P2_NOTRACE_EXEC) == 0)
756677258f7SKonstantin Belousov 		p->p_flag2 &= ~P2_NOTRACE;
757fe69291fSKonstantin Belousov 	if ((p->p_flag2 & P2_STKGAP_DISABLE_EXEC) == 0)
758fe69291fSKonstantin Belousov 		p->p_flag2 &= ~P2_STKGAP_DISABLE;
759965d0860SMateusz Guzik 	if (p->p_flag & P_PPWAIT) {
760888d4d4fSKonstantin Belousov 		p->p_flag &= ~(P_PPWAIT | P_PPTRACE);
761aeb32571SKonstantin Belousov 		cv_broadcast(&p->p_pwait);
76277d68094SKonstantin Belousov 		/* STOPs are no longer ignored, arrange for AST */
76377d68094SKonstantin Belousov 		signotify(td);
76426f9a767SRodney W. Grimes 	}
76526f9a767SRodney W. Grimes 
76626f9a767SRodney W. Grimes 	/*
767881010f0SBryan Drewery 	 * Implement image setuid/setgid installation.
768c52007c2SDavid Greenman 	 */
769881010f0SBryan Drewery 	if (imgp->credential_setid) {
770c52007c2SDavid Greenman 		/*
771c52007c2SDavid Greenman 		 * Turn off syscall tracing for set-id programs, except for
772b85db196SPeter Wemm 		 * root.  Record any set-id flags first to make sure that
773b85db196SPeter Wemm 		 * we do not regain any tracing during a possible block.
77426f9a767SRodney W. Grimes 		 */
775b85db196SPeter Wemm 		setsugid(p);
776acd3428bSRobert Watson 
7776c84de02SJohn Baldwin #ifdef KTRACE
778c331c970SAndriy Gapon 		if (p->p_tracecred != NULL &&
779cc426dd3SMateusz Guzik 		    priv_check_cred(p->p_tracecred, PRIV_DEBUG_DIFFCRED))
780d680caabSJohn Baldwin 			ktrprocexec(p, &tracecred, &tracevp);
7816c84de02SJohn Baldwin #endif
78228b325aaSDon Lewis 		/*
783c1e2d386SNate Lawson 		 * Close any file descriptors 0..2 that reference procfs,
784c1e2d386SNate Lawson 		 * then make sure file descriptors 0..2 are in use.
78528b325aaSDon Lewis 		 *
7868a5177ccSMateusz Guzik 		 * Both fdsetugidsafety() and fdcheckstd() may call functions
7878a5177ccSMateusz Guzik 		 * taking sleepable locks, so temporarily drop our locks.
78828b325aaSDon Lewis 		 */
78928b325aaSDon Lewis 		PROC_UNLOCK(p);
790*b249ce48SMateusz Guzik 		VOP_UNLOCK(imgp->vp);
79111888da8SMateusz Guzik 		fdsetugidsafety(td);
792e983a376SJacques Vidrine 		error = fdcheckstd(td);
7935e2554b7SMateusz Guzik 		vn_lock(imgp->vp, LK_SHARED | LK_RETRY);
794cda68844SMateusz Guzik 		if (error != 0)
795cda68844SMateusz Guzik 			goto exec_fail_dealloc;
796e1b1aa3bSJohn Baldwin 		PROC_LOCK(p);
797ccafe7ebSRobert Watson #ifdef MAC
798670cb89bSRobert Watson 		if (will_transition) {
799881010f0SBryan Drewery 			mac_vnode_execve_transition(oldcred, imgp->newcred,
800881010f0SBryan Drewery 			    imgp->vp, interpvplabel, imgp);
801670cb89bSRobert Watson 		}
802ccafe7ebSRobert Watson #endif
803c52007c2SDavid Greenman 	} else {
804b1fc0ec1SRobert Watson 		if (oldcred->cr_uid == oldcred->cr_ruid &&
805b1fc0ec1SRobert Watson 		    oldcred->cr_gid == oldcred->cr_rgid)
806c52007c2SDavid Greenman 			p->p_flag &= ~P_SUGID;
807881010f0SBryan Drewery 	}
80826f9a767SRodney W. Grimes 	/*
809881010f0SBryan Drewery 	 * Set the new credentials.
81026f9a767SRodney W. Grimes 	 */
8113fc292d5SKonstantin Belousov 	if (imgp->newcred != NULL) {
812881010f0SBryan Drewery 		proc_set_cred(p, imgp->newcred);
8133fc292d5SKonstantin Belousov 		crfree(oldcred);
8143fc292d5SKonstantin Belousov 		oldcred = NULL;
8153fc292d5SKonstantin Belousov 	}
81626f9a767SRodney W. Grimes 
81726f9a767SRodney W. Grimes 	/*
818853be5ffSMateusz Guzik 	 * Store the vp for use in procfs.  This vnode was referenced by namei
819853be5ffSMateusz Guzik 	 * or fgetvp_exec.
8202a531c80SDavid Greenman 	 */
82161617058SMateusz Guzik 	oldtextvp = p->p_textvp;
82261617058SMateusz Guzik 	p->p_textvp = newtextvp;
8232a531c80SDavid Greenman 
8245d217f17SJohn Birrell #ifdef KDTRACE_HOOKS
8255d217f17SJohn Birrell 	/*
8265d217f17SJohn Birrell 	 * Tell the DTrace fasttrap provider about the exec if it
8275d217f17SJohn Birrell 	 * has declared an interest.
8285d217f17SJohn Birrell 	 */
8295d217f17SJohn Birrell 	if (dtrace_fasttrap_exec)
8305d217f17SJohn Birrell 		dtrace_fasttrap_exec(p);
8315d217f17SJohn Birrell #endif
8325d217f17SJohn Birrell 
8332a531c80SDavid Greenman 	/*
8349ca45e81SDag-Erling Smørgrav 	 * Notify others that we exec'd, and clear the P_INEXEC flag
8359ca45e81SDag-Erling Smørgrav 	 * as we're now a bona fide freshly-execed process.
836cb679c38SJonathan Lemon 	 */
8379e590ff0SKonstantin Belousov 	KNOTE_LOCKED(p->p_klist, NOTE_EXEC);
8389ca45e81SDag-Erling Smørgrav 	p->p_flag &= ~P_INEXEC;
839cb679c38SJonathan Lemon 
84026f9a767SRodney W. Grimes 	/* clear "fork but no exec" flag, as we _are_ execing */
84126f9a767SRodney W. Grimes 	p->p_acflag &= ~AFORK;
84226f9a767SRodney W. Grimes 
8435997cae9SDon Lewis 	/*
84434ea500bSDon Lewis 	 * Free any previous argument cache and replace it with
8455997cae9SDon Lewis 	 * the new argument cache, if any.
8465997cae9SDon Lewis 	 */
8479b3b1c5fSJohn Baldwin 	oldargs = p->p_args;
848e1b1aa3bSJohn Baldwin 	p->p_args = newargs;
849e1b1aa3bSJohn Baldwin 	newargs = NULL;
850ebccf1e3SJoseph Koshy 
85180a2397aSMateusz Guzik 	PROC_UNLOCK(p);
85280a2397aSMateusz Guzik 
853ebccf1e3SJoseph Koshy #ifdef	HWPMC_HOOKS
854ebccf1e3SJoseph Koshy 	/*
855f263522aSJoseph Koshy 	 * Check if system-wide sampling is in effect or if the
856f263522aSJoseph Koshy 	 * current process is using PMCs.  If so, do exec() time
857ebccf1e3SJoseph Koshy 	 * processing.  This processing needs to happen AFTER the
858ebccf1e3SJoseph Koshy 	 * P_INEXEC flag is cleared.
859ebccf1e3SJoseph Koshy 	 */
860f263522aSJoseph Koshy 	if (PMC_SYSTEM_SAMPLING_ACTIVE() || PMC_PROC_IS_USING_PMCS(p)) {
861*b249ce48SMateusz Guzik 		VOP_UNLOCK(imgp->vp);
86215139246SJoseph Koshy 		pe.pm_credentialschanged = credential_changing;
86315139246SJoseph Koshy 		pe.pm_entryaddr = imgp->entry_addr;
86415139246SJoseph Koshy 
86515139246SJoseph Koshy 		PMC_CALL_HOOK_X(td, PMC_FN_PROCESS_EXEC, (void *) &pe);
8662974cc36SKonstantin Belousov 		vn_lock(imgp->vp, LK_SHARED | LK_RETRY);
86780a2397aSMateusz Guzik 	}
868ebccf1e3SJoseph Koshy #endif
869e1b1aa3bSJohn Baldwin 
870e913ca22SDoug Rabson 	/* Set values passed into the program in registers. */
87131174518SJohn Baldwin 	(*p->p_sysent->sv_setregs)(td, imgp, stack_base);
872e913ca22SDoug Rabson 
8730359a12eSAttilio Rao 	vfs_mark_atime(imgp->vp, td->td_ucred);
8746341095eSKen Smith 
87536160958SMark Johnston 	SDT_PROBE1(proc, , , exec__success, args->fname);
8765d217f17SJohn Birrell 
8771616db3cSJohn Dyson exec_fail_dealloc:
87801a2b567SKonstantin Belousov 	if (error != 0) {
87901a2b567SKonstantin Belousov 		p->p_osrel = orig_osrel;
88001a2b567SKonstantin Belousov 		p->p_fctl0 = orig_fctl0;
88101a2b567SKonstantin Belousov 	}
88201a2b567SKonstantin Belousov 
883d6c847f3SBruce Evans 	if (imgp->firstpage != NULL)
8841616db3cSJohn Dyson 		exec_unmap_first_page(imgp);
88526f9a767SRodney W. Grimes 
886d6c847f3SBruce Evans 	if (imgp->vp != NULL) {
887632dbc19SKonstantin Belousov 		if (args->fname)
88869c9eff8SEd Schouten 			NDFREE(&nd, NDF_ONLY_PNBUF);
8899a75ea23SKonstantin Belousov 		if (imgp->opened)
8909a75ea23SKonstantin Belousov 			VOP_CLOSE(imgp->vp, FREAD, td->td_ucred, td);
89178022527SKonstantin Belousov 		if (imgp->textset)
89278022527SKonstantin Belousov 			VOP_UNSET_TEXT_CHECKED(imgp->vp);
893853be5ffSMateusz Guzik 		if (error != 0)
894619eb6e5SJeff Roberson 			vput(imgp->vp);
895853be5ffSMateusz Guzik 		else
896*b249ce48SMateusz Guzik 			VOP_UNLOCK(imgp->vp);
897a3cf6ebaSDavid Greenman 	}
89826f9a767SRodney W. Grimes 
899d6c847f3SBruce Evans 	if (imgp->object != NULL)
9000b2ed1aeSJeff Roberson 		vm_object_deallocate(imgp->object);
9010b2ed1aeSJeff Roberson 
9023ff06357SKonstantin Belousov 	free(imgp->freepath, M_TEMP);
9033ff06357SKonstantin Belousov 
904d1989db5SRobert Drehmel 	if (error == 0) {
905e6b645aeSMateusz Guzik 		if (p->p_ptevents & PTRACE_EXEC) {
906afe1a688SKonstantin Belousov 			PROC_LOCK(p);
9078d570f64SJohn Baldwin 			if (p->p_ptevents & PTRACE_EXEC)
908afe1a688SKonstantin Belousov 				td->td_dbgflags |= TDB_EXEC;
909afe1a688SKonstantin Belousov 			PROC_UNLOCK(p);
910e6b645aeSMateusz Guzik 		}
911afe1a688SKonstantin Belousov 
912d1989db5SRobert Drehmel 		/*
913d1989db5SRobert Drehmel 		 * Stop the process here if its stop event mask has
914d1989db5SRobert Drehmel 		 * the S_EXEC bit set.
915d1989db5SRobert Drehmel 		 */
916d1989db5SRobert Drehmel 		STOPEVENT(p, S_EXEC, 0);
917cda68844SMateusz Guzik 	} else {
91826f9a767SRodney W. Grimes exec_fail:
9199ca45e81SDag-Erling Smørgrav 		/* we're done here, clear P_INEXEC */
9209ca45e81SDag-Erling Smørgrav 		PROC_LOCK(p);
9219ca45e81SDag-Erling Smørgrav 		p->p_flag &= ~P_INEXEC;
9229ca45e81SDag-Erling Smørgrav 		PROC_UNLOCK(p);
9239ca45e81SDag-Erling Smørgrav 
92436160958SMark Johnston 		SDT_PROBE1(proc, , , exec__failure, error);
925cda68844SMateusz Guzik 	}
9265d217f17SJohn Birrell 
9273fc292d5SKonstantin Belousov 	if (imgp->newcred != NULL && oldcred != NULL)
9283fc292d5SKonstantin Belousov 		crfree(imgp->newcred);
9293fc292d5SKonstantin Belousov 
930670cb89bSRobert Watson #ifdef MAC
931670cb89bSRobert Watson 	mac_execve_exit(imgp);
9326356dba0SRobert Watson 	mac_execve_interpreter_exit(interpvplabel);
933670cb89bSRobert Watson #endif
9348917b8d2SJohn Baldwin 	exec_free_args(args);
9358917b8d2SJohn Baldwin 
936cda68844SMateusz Guzik 	/*
937cda68844SMateusz Guzik 	 * Handle deferred decrement of ref counts.
938cda68844SMateusz Guzik 	 */
939cda68844SMateusz Guzik 	if (oldtextvp != NULL)
940cda68844SMateusz Guzik 		vrele(oldtextvp);
941cda68844SMateusz Guzik #ifdef KTRACE
942cda68844SMateusz Guzik 	if (tracevp != NULL)
943cda68844SMateusz Guzik 		vrele(tracevp);
944cda68844SMateusz Guzik 	if (tracecred != NULL)
945cda68844SMateusz Guzik 		crfree(tracecred);
946cda68844SMateusz Guzik #endif
947cda68844SMateusz Guzik 	pargs_drop(oldargs);
948cda68844SMateusz Guzik 	pargs_drop(newargs);
949cda68844SMateusz Guzik 	if (oldsigacts != NULL)
950cda68844SMateusz Guzik 		sigacts_free(oldsigacts);
951cda68844SMateusz Guzik 	if (euip != NULL)
952cda68844SMateusz Guzik 		uifree(euip);
953cda68844SMateusz Guzik 
9548917b8d2SJohn Baldwin 	if (error && imgp->vmspace_destroyed) {
9558917b8d2SJohn Baldwin 		/* sorry, no more process anymore. exit gracefully */
956b4490c6eSKonstantin Belousov 		exit1(td, 0, SIGABRT);
9578917b8d2SJohn Baldwin 		/* NOT REACHED */
9588917b8d2SJohn Baldwin 	}
9597705d4b2SDmitry Chagin 
9607705d4b2SDmitry Chagin #ifdef KTRACE
9617705d4b2SDmitry Chagin 	if (error == 0)
9627705d4b2SDmitry Chagin 		ktrprocctor(p);
9637705d4b2SDmitry Chagin #endif
9647705d4b2SDmitry Chagin 
965814629ddSEd Schouten 	/*
966814629ddSEd Schouten 	 * We don't want cpu_set_syscall_retval() to overwrite any of
967814629ddSEd Schouten 	 * the register values put in place by exec_setregs().
968814629ddSEd Schouten 	 * Implementations of cpu_set_syscall_retval() will leave
969814629ddSEd Schouten 	 * registers unmodified when returning EJUSTRETURN.
970814629ddSEd Schouten 	 */
971814629ddSEd Schouten 	return (error == 0 ? EJUSTRETURN : error);
97226f9a767SRodney W. Grimes }
97326f9a767SRodney W. Grimes 
9741616db3cSJohn Dyson int
975b8d908b7SEd Maste exec_map_first_page(struct image_params *imgp)
9761616db3cSJohn Dyson {
9771616db3cSJohn Dyson 	vm_object_t object;
978af009714SJeff Roberson 	vm_page_t m;
979af009714SJeff Roberson 	int error;
9801616db3cSJohn Dyson 
981d6c847f3SBruce Evans 	if (imgp->firstpage != NULL)
9821616db3cSJohn Dyson 		exec_unmap_first_page(imgp);
9831616db3cSJohn Dyson 
9848516dd18SPoul-Henning Kamp 	object = imgp->vp->v_object;
9854d7d2993SJeff Roberson 	if (object == NULL)
9864d7d2993SJeff Roberson 		return (EACCES);
98789f6b863SAttilio Rao 	VM_OBJECT_WLOCK(object);
988f8a47341SAlan Cox #if VM_NRESERVLEVEL > 0
9893d653db0SAlan Cox 	vm_object_color(object, 0);
990f8a47341SAlan Cox #endif
991af009714SJeff Roberson 	error = vm_page_grab_valid(&m, object, 0,
992af009714SJeff Roberson 	    VM_ALLOC_COUNT(VM_INITIAL_PAGEIN) |
993af009714SJeff Roberson             VM_ALLOC_NORMAL | VM_ALLOC_NOBUSY | VM_ALLOC_WIRED);
99489f6b863SAttilio Rao 	VM_OBJECT_WUNLOCK(object);
9951616db3cSJohn Dyson 
996af009714SJeff Roberson 	if (error != VM_PAGER_OK)
997af009714SJeff Roberson 		return (EIO);
998af009714SJeff Roberson 	imgp->firstpage = sf_buf_alloc(m, 0);
99959c8bc40SAlan Cox 	imgp->image_header = (char *)sf_buf_kva(imgp->firstpage);
10001616db3cSJohn Dyson 
1001a7cddfedSJake Burkholder 	return (0);
10021616db3cSJohn Dyson }
10031616db3cSJohn Dyson 
10041616db3cSJohn Dyson void
10053e85b721SEd Maste exec_unmap_first_page(struct image_params *imgp)
10061616db3cSJohn Dyson {
100759c8bc40SAlan Cox 	vm_page_t m;
100823955314SAlfred Perlstein 
1009d6c847f3SBruce Evans 	if (imgp->firstpage != NULL) {
101059c8bc40SAlan Cox 		m = sf_buf_page(imgp->firstpage);
101159c8bc40SAlan Cox 		sf_buf_free(imgp->firstpage);
10121616db3cSJohn Dyson 		imgp->firstpage = NULL;
1013eeacb3b0SMark Johnston 		vm_page_unwire(m, PQ_ACTIVE);
10141616db3cSJohn Dyson 	}
10151616db3cSJohn Dyson }
10161616db3cSJohn Dyson 
101726f9a767SRodney W. Grimes /*
1018467b3975SKonstantin Belousov  * Destroy old address space, and allocate a new stack.
1019467b3975SKonstantin Belousov  *	The new stack is only sgrowsiz large because it is grown
1020467b3975SKonstantin Belousov  *	automatically on a page fault.
102126f9a767SRodney W. Grimes  */
102226f9a767SRodney W. Grimes int
10233e85b721SEd Maste exec_new_vmspace(struct image_params *imgp, struct sysentvec *sv)
102426f9a767SRodney W. Grimes {
102526f9a767SRodney W. Grimes 	int error;
10265e20c11fSAlan Cox 	struct proc *p = imgp->proc;
10275e20c11fSAlan Cox 	struct vmspace *vmspace = p->p_vmspace;
10286297a3d8SKonstantin Belousov 	vm_object_t obj;
1029316b3843SKonstantin Belousov 	struct rlimit rlim_stack;
1030878adb85SBjoern A. Zeeb 	vm_offset_t sv_minuser, stack_addr;
103105ba50f5SJake Burkholder 	vm_map_t map;
103259d8f3ffSJohn Baldwin 	u_long ssiz;
103326f9a767SRodney W. Grimes 
1034c52007c2SDavid Greenman 	imgp->vmspace_destroyed = 1;
1035993182e5SAlexander Leidinger 	imgp->sysent = sv;
103626f9a767SRodney W. Grimes 
1037bd37fd72SKris Kennaway 	/* May be called with Giant held */
10382ca45184SMatt Joras 	EVENTHANDLER_DIRECT_INVOKE(process_exec, p, imgp);
10396f5dafeaSAlan Cox 
10406f5dafeaSAlan Cox 	/*
1041af9ec885SJohn Dyson 	 * Blow away entire process VM, if address space not shared,
1042af9ec885SJohn Dyson 	 * otherwise, create a new VM space so that other threads are
1043af9ec885SJohn Dyson 	 * not disrupted
1044af9ec885SJohn Dyson 	 */
104505ba50f5SJake Burkholder 	map = &vmspace->vm_map;
1046878adb85SBjoern A. Zeeb 	if (map_at_zero)
1047878adb85SBjoern A. Zeeb 		sv_minuser = sv->sv_minuser;
1048878adb85SBjoern A. Zeeb 	else
1049878adb85SBjoern A. Zeeb 		sv_minuser = MAX(sv->sv_minuser, PAGE_SIZE);
1050878adb85SBjoern A. Zeeb 	if (vmspace->vm_refcnt == 1 && vm_map_min(map) == sv_minuser &&
10516f1fe330SKonstantin Belousov 	    vm_map_max(map) == sv->sv_maxuser &&
10526f1fe330SKonstantin Belousov 	    cpu_exec_vmspace_reuse(p, map)) {
10533db161e0SMatthew Dillon 		shmexit(vmspace);
1054b9eee07eSPeter Wemm 		pmap_remove_pages(vmspace_pmap(vmspace));
105505ba50f5SJake Burkholder 		vm_map_remove(map, vm_map_min(map), vm_map_max(map));
1056fa50a355SKonstantin Belousov 		/*
1057fa50a355SKonstantin Belousov 		 * An exec terminates mlockall(MCL_FUTURE), ASLR state
1058fa50a355SKonstantin Belousov 		 * must be re-evaluated.
1059fa50a355SKonstantin Belousov 		 */
10608056df6eSAlan Cox 		vm_map_lock(map);
1061fa50a355SKonstantin Belousov 		vm_map_modflags(map, 0, MAP_WIREFUTURE | MAP_ASLR |
1062fa50a355SKonstantin Belousov 		    MAP_ASLR_IGNSTART);
10638056df6eSAlan Cox 		vm_map_unlock(map);
1064af9ec885SJohn Dyson 	} else {
1065878adb85SBjoern A. Zeeb 		error = vmspace_exec(p, sv_minuser, sv->sv_maxuser);
106689b57fcfSKonstantin Belousov 		if (error)
106789b57fcfSKonstantin Belousov 			return (error);
10685e20c11fSAlan Cox 		vmspace = p->p_vmspace;
106905ba50f5SJake Burkholder 		map = &vmspace->vm_map;
1070af9ec885SJohn Dyson 	}
1071fa50a355SKonstantin Belousov 	map->flags |= imgp->map_flags;
107226f9a767SRodney W. Grimes 
10736297a3d8SKonstantin Belousov 	/* Map a shared page */
10746297a3d8SKonstantin Belousov 	obj = sv->sv_shared_page_obj;
10756297a3d8SKonstantin Belousov 	if (obj != NULL) {
10766297a3d8SKonstantin Belousov 		vm_object_reference(obj);
10776297a3d8SKonstantin Belousov 		error = vm_map_fixed(map, obj, 0,
10786297a3d8SKonstantin Belousov 		    sv->sv_shared_page_base, sv->sv_shared_page_len,
10791e65d73cSKonstantin Belousov 		    VM_PROT_READ | VM_PROT_EXECUTE,
10801e65d73cSKonstantin Belousov 		    VM_PROT_READ | VM_PROT_EXECUTE,
10811e65d73cSKonstantin Belousov 		    MAP_INHERIT_SHARE | MAP_ACC_NO_CHARGE);
1082467b3975SKonstantin Belousov 		if (error != KERN_SUCCESS) {
10836297a3d8SKonstantin Belousov 			vm_object_deallocate(obj);
1084467b3975SKonstantin Belousov 			return (vm_mmap_to_errno(error));
10856297a3d8SKonstantin Belousov 		}
10866297a3d8SKonstantin Belousov 	}
10876297a3d8SKonstantin Belousov 
108826f9a767SRodney W. Grimes 	/* Allocate a new stack */
1089316b3843SKonstantin Belousov 	if (imgp->stack_sz != 0) {
1090fe8a824cSKonstantin Belousov 		ssiz = trunc_page(imgp->stack_sz);
1091316b3843SKonstantin Belousov 		PROC_LOCK(p);
1092f6f6d240SMateusz Guzik 		lim_rlimit_proc(p, RLIMIT_STACK, &rlim_stack);
1093316b3843SKonstantin Belousov 		PROC_UNLOCK(p);
1094316b3843SKonstantin Belousov 		if (ssiz > rlim_stack.rlim_max)
1095316b3843SKonstantin Belousov 			ssiz = rlim_stack.rlim_max;
1096316b3843SKonstantin Belousov 		if (ssiz > rlim_stack.rlim_cur) {
1097316b3843SKonstantin Belousov 			rlim_stack.rlim_cur = ssiz;
1098316b3843SKonstantin Belousov 			kern_setrlimit(curthread, RLIMIT_STACK, &rlim_stack);
1099316b3843SKonstantin Belousov 		}
1100316b3843SKonstantin Belousov 	} else if (sv->sv_maxssiz != NULL) {
110159d8f3ffSJohn Baldwin 		ssiz = *sv->sv_maxssiz;
1102316b3843SKonstantin Belousov 	} else {
110359d8f3ffSJohn Baldwin 		ssiz = maxssiz;
1104316b3843SKonstantin Belousov 	}
110501c3ba97SKonstantin Belousov 	imgp->eff_stack_sz = lim_cur(curthread, RLIMIT_STACK);
110601c3ba97SKonstantin Belousov 	if (ssiz < imgp->eff_stack_sz)
1107fc83c5a7SKonstantin Belousov 		imgp->eff_stack_sz = ssiz;
110859d8f3ffSJohn Baldwin 	stack_addr = sv->sv_usrstack - ssiz;
110959d8f3ffSJohn Baldwin 	error = vm_map_stack(map, stack_addr, (vm_size_t)ssiz,
11106297a3d8SKonstantin Belousov 	    obj != NULL && imgp->stack_prot != 0 ? imgp->stack_prot :
1111467b3975SKonstantin Belousov 	    sv->sv_stackprot, VM_PROT_ALL, MAP_STACK_GROWS_DOWN);
1112467b3975SKonstantin Belousov 	if (error != KERN_SUCCESS)
1113467b3975SKonstantin Belousov 		return (vm_mmap_to_errno(error));
11142267af78SJulian Elischer 
111578960940SAlan Cox 	/*
111678960940SAlan Cox 	 * vm_ssize and vm_maxsaddr are somewhat antiquated concepts, but they
111778960940SAlan Cox 	 * are still used to enforce the stack rlimit on the process stack.
11182267af78SJulian Elischer 	 */
1119cbc89bfbSPaul Saab 	vmspace->vm_ssize = sgrowsiz >> PAGE_SHIFT;
11206ef12002SKonstantin Belousov 	vmspace->vm_maxsaddr = (char *)stack_addr;
112126f9a767SRodney W. Grimes 
112226f9a767SRodney W. Grimes 	return (0);
112326f9a767SRodney W. Grimes }
112426f9a767SRodney W. Grimes 
112526f9a767SRodney W. Grimes /*
1126873fbcd7SRobert Watson  * Copy out argument and environment strings from the old process address
1127873fbcd7SRobert Watson  * space into the temporary string buffer.
112826f9a767SRodney W. Grimes  */
112926f9a767SRodney W. Grimes int
113012e69f96SBrooks Davis exec_copyin_args(struct image_args *args, const char *fname,
1131610ecfe0SMaxim Sobolev     enum uio_seg segflg, char **argv, char **envv)
113226f9a767SRodney W. Grimes {
1133f373437aSBrooks Davis 	u_long arg, env;
1134ecbb00a2SDoug Rabson 	int error;
113526f9a767SRodney W. Grimes 
1136610ecfe0SMaxim Sobolev 	bzero(args, sizeof(*args));
1137610ecfe0SMaxim Sobolev 	if (argv == NULL)
1138610ecfe0SMaxim Sobolev 		return (EFAULT);
11392af6e14dSAlan Cox 
114026f9a767SRodney W. Grimes 	/*
11412af6e14dSAlan Cox 	 * Allocate demand-paged memory for the file name, argument, and
11422af6e14dSAlan Cox 	 * environment strings.
114326f9a767SRodney W. Grimes 	 */
11442af6e14dSAlan Cox 	error = exec_alloc_args(args);
11452af6e14dSAlan Cox 	if (error != 0)
11462af6e14dSAlan Cox 		return (error);
11479e4e5114SAlan Cox 
1148610ecfe0SMaxim Sobolev 	/*
1149610ecfe0SMaxim Sobolev 	 * Copy the file name.
1150610ecfe0SMaxim Sobolev 	 */
1151f373437aSBrooks Davis 	error = exec_args_add_fname(args, fname, segflg);
1152c30af532SMaxim Sobolev 	if (error != 0)
115368ff3c24SStephan Uphoff 		goto err_exit;
115426f9a767SRodney W. Grimes 
1155610ecfe0SMaxim Sobolev 	/*
1156610ecfe0SMaxim Sobolev 	 * extract arguments first
1157610ecfe0SMaxim Sobolev 	 */
11580a2c94b8SKonstantin Belousov 	for (;;) {
1159f373437aSBrooks Davis 		error = fueword(argv++, &arg);
11600a2c94b8SKonstantin Belousov 		if (error == -1) {
116168ff3c24SStephan Uphoff 			error = EFAULT;
116268ff3c24SStephan Uphoff 			goto err_exit;
116368ff3c24SStephan Uphoff 		}
1164f373437aSBrooks Davis 		if (arg == 0)
11650a2c94b8SKonstantin Belousov 			break;
1166f373437aSBrooks Davis 		error = exec_args_add_arg(args, (char *)(uintptr_t)arg,
1167f373437aSBrooks Davis 		    UIO_USERSPACE);
1168f373437aSBrooks Davis 		if (error != 0)
116968ff3c24SStephan Uphoff 			goto err_exit;
1170610ecfe0SMaxim Sobolev 	}
1171b9df5231SPoul-Henning Kamp 
117226f9a767SRodney W. Grimes 	/*
117326f9a767SRodney W. Grimes 	 * extract environment strings
117426f9a767SRodney W. Grimes 	 */
11750fd1a014SDavid Greenman 	if (envv) {
11760a2c94b8SKonstantin Belousov 		for (;;) {
1177f373437aSBrooks Davis 			error = fueword(envv++, &env);
11780a2c94b8SKonstantin Belousov 			if (error == -1) {
117968ff3c24SStephan Uphoff 				error = EFAULT;
118068ff3c24SStephan Uphoff 				goto err_exit;
118168ff3c24SStephan Uphoff 			}
1182f373437aSBrooks Davis 			if (env == 0)
11830a2c94b8SKonstantin Belousov 				break;
1184f373437aSBrooks Davis 			error = exec_args_add_env(args,
1185f373437aSBrooks Davis 			    (char *)(uintptr_t)env, UIO_USERSPACE);
1186f373437aSBrooks Davis 			if (error != 0)
118768ff3c24SStephan Uphoff 				goto err_exit;
11880fd1a014SDavid Greenman 		}
11890fd1a014SDavid Greenman 	}
119026f9a767SRodney W. Grimes 
119126f9a767SRodney W. Grimes 	return (0);
119268ff3c24SStephan Uphoff 
119368ff3c24SStephan Uphoff err_exit:
119468ff3c24SStephan Uphoff 	exec_free_args(args);
119568ff3c24SStephan Uphoff 	return (error);
119626f9a767SRodney W. Grimes }
119726f9a767SRodney W. Grimes 
1198457f7e23SEd Schouten int
1199457f7e23SEd Schouten exec_copyin_data_fds(struct thread *td, struct image_args *args,
1200457f7e23SEd Schouten     const void *data, size_t datalen, const int *fds, size_t fdslen)
1201457f7e23SEd Schouten {
1202457f7e23SEd Schouten 	struct filedesc *ofdp;
1203457f7e23SEd Schouten 	const char *p;
1204457f7e23SEd Schouten 	int *kfds;
1205457f7e23SEd Schouten 	int error;
1206457f7e23SEd Schouten 
1207457f7e23SEd Schouten 	memset(args, '\0', sizeof(*args));
1208457f7e23SEd Schouten 	ofdp = td->td_proc->p_fd;
1209457f7e23SEd Schouten 	if (datalen >= ARG_MAX || fdslen > ofdp->fd_lastfile + 1)
1210457f7e23SEd Schouten 		return (E2BIG);
1211457f7e23SEd Schouten 	error = exec_alloc_args(args);
1212457f7e23SEd Schouten 	if (error != 0)
1213457f7e23SEd Schouten 		return (error);
1214457f7e23SEd Schouten 
1215457f7e23SEd Schouten 	args->begin_argv = args->buf;
1216457f7e23SEd Schouten 	args->stringspace = ARG_MAX;
1217457f7e23SEd Schouten 
1218457f7e23SEd Schouten 	if (datalen > 0) {
1219457f7e23SEd Schouten 		/*
1220457f7e23SEd Schouten 		 * Argument buffer has been provided. Copy it into the
1221457f7e23SEd Schouten 		 * kernel as a single string and add a terminating null
1222457f7e23SEd Schouten 		 * byte.
1223457f7e23SEd Schouten 		 */
1224457f7e23SEd Schouten 		error = copyin(data, args->begin_argv, datalen);
1225457f7e23SEd Schouten 		if (error != 0)
1226457f7e23SEd Schouten 			goto err_exit;
1227457f7e23SEd Schouten 		args->begin_argv[datalen] = '\0';
1228457f7e23SEd Schouten 		args->endp = args->begin_argv + datalen + 1;
1229457f7e23SEd Schouten 		args->stringspace -= datalen + 1;
1230457f7e23SEd Schouten 
1231457f7e23SEd Schouten 		/*
1232457f7e23SEd Schouten 		 * Traditional argument counting. Count the number of
1233457f7e23SEd Schouten 		 * null bytes.
1234457f7e23SEd Schouten 		 */
1235457f7e23SEd Schouten 		for (p = args->begin_argv; p < args->endp; ++p)
1236457f7e23SEd Schouten 			if (*p == '\0')
1237457f7e23SEd Schouten 				++args->argc;
1238457f7e23SEd Schouten 	} else {
1239457f7e23SEd Schouten 		/* No argument buffer provided. */
1240457f7e23SEd Schouten 		args->endp = args->begin_argv;
1241457f7e23SEd Schouten 	}
1242457f7e23SEd Schouten 
1243457f7e23SEd Schouten 	/* Create new file descriptor table. */
1244457f7e23SEd Schouten 	kfds = malloc(fdslen * sizeof(int), M_TEMP, M_WAITOK);
1245457f7e23SEd Schouten 	error = copyin(fds, kfds, fdslen * sizeof(int));
1246457f7e23SEd Schouten 	if (error != 0) {
1247457f7e23SEd Schouten 		free(kfds, M_TEMP);
1248457f7e23SEd Schouten 		goto err_exit;
1249457f7e23SEd Schouten 	}
1250457f7e23SEd Schouten 	error = fdcopy_remapped(ofdp, kfds, fdslen, &args->fdp);
1251457f7e23SEd Schouten 	free(kfds, M_TEMP);
1252457f7e23SEd Schouten 	if (error != 0)
1253457f7e23SEd Schouten 		goto err_exit;
1254457f7e23SEd Schouten 
1255457f7e23SEd Schouten 	return (0);
1256457f7e23SEd Schouten err_exit:
1257457f7e23SEd Schouten 	exec_free_args(args);
1258457f7e23SEd Schouten 	return (error);
1259457f7e23SEd Schouten }
1260457f7e23SEd Schouten 
1261ec492b13SMark Johnston struct exec_args_kva {
1262ec492b13SMark Johnston 	vm_offset_t addr;
1263c6a4ba5aSMark Johnston 	u_int gen;
1264ec492b13SMark Johnston 	SLIST_ENTRY(exec_args_kva) next;
1265ec492b13SMark Johnston };
1266ec492b13SMark Johnston 
12672bf95012SAndrew Turner DPCPU_DEFINE_STATIC(struct exec_args_kva *, exec_args_kva);
1268ec492b13SMark Johnston 
1269ec492b13SMark Johnston static SLIST_HEAD(, exec_args_kva) exec_args_kva_freelist;
1270ec492b13SMark Johnston static struct mtx exec_args_kva_mtx;
1271c6a4ba5aSMark Johnston static u_int exec_args_gen;
1272ec492b13SMark Johnston 
1273ec492b13SMark Johnston static void
1274ec492b13SMark Johnston exec_prealloc_args_kva(void *arg __unused)
1275ec492b13SMark Johnston {
1276ec492b13SMark Johnston 	struct exec_args_kva *argkva;
1277ec492b13SMark Johnston 	u_int i;
1278ec492b13SMark Johnston 
1279ec492b13SMark Johnston 	SLIST_INIT(&exec_args_kva_freelist);
1280ec492b13SMark Johnston 	mtx_init(&exec_args_kva_mtx, "exec args kva", NULL, MTX_DEF);
1281ec492b13SMark Johnston 	for (i = 0; i < exec_map_entries; i++) {
1282ec492b13SMark Johnston 		argkva = malloc(sizeof(*argkva), M_PARGS, M_WAITOK);
1283ec492b13SMark Johnston 		argkva->addr = kmap_alloc_wait(exec_map, exec_map_entry_size);
1284c6a4ba5aSMark Johnston 		argkva->gen = exec_args_gen;
1285ec492b13SMark Johnston 		SLIST_INSERT_HEAD(&exec_args_kva_freelist, argkva, next);
1286ec492b13SMark Johnston 	}
1287ec492b13SMark Johnston }
1288ec492b13SMark Johnston SYSINIT(exec_args_kva, SI_SUB_EXEC, SI_ORDER_ANY, exec_prealloc_args_kva, NULL);
1289ec492b13SMark Johnston 
1290ec492b13SMark Johnston static vm_offset_t
1291ec492b13SMark Johnston exec_alloc_args_kva(void **cookie)
1292ec492b13SMark Johnston {
1293ec492b13SMark Johnston 	struct exec_args_kva *argkva;
1294ec492b13SMark Johnston 
1295ec492b13SMark Johnston 	argkva = (void *)atomic_readandclear_ptr(
1296ec492b13SMark Johnston 	    (uintptr_t *)DPCPU_PTR(exec_args_kva));
1297ec492b13SMark Johnston 	if (argkva == NULL) {
1298ec492b13SMark Johnston 		mtx_lock(&exec_args_kva_mtx);
1299ec492b13SMark Johnston 		while ((argkva = SLIST_FIRST(&exec_args_kva_freelist)) == NULL)
1300ec492b13SMark Johnston 			(void)mtx_sleep(&exec_args_kva_freelist,
1301ec492b13SMark Johnston 			    &exec_args_kva_mtx, 0, "execkva", 0);
1302ec492b13SMark Johnston 		SLIST_REMOVE_HEAD(&exec_args_kva_freelist, next);
1303ec492b13SMark Johnston 		mtx_unlock(&exec_args_kva_mtx);
1304ec492b13SMark Johnston 	}
1305ec492b13SMark Johnston 	*(struct exec_args_kva **)cookie = argkva;
1306ec492b13SMark Johnston 	return (argkva->addr);
1307ec492b13SMark Johnston }
1308ec492b13SMark Johnston 
1309ec492b13SMark Johnston static void
1310c6a4ba5aSMark Johnston exec_release_args_kva(struct exec_args_kva *argkva, u_int gen)
1311ec492b13SMark Johnston {
1312ec492b13SMark Johnston 	vm_offset_t base;
1313ec492b13SMark Johnston 
1314ec492b13SMark Johnston 	base = argkva->addr;
1315c6a4ba5aSMark Johnston 	if (argkva->gen != gen) {
13163e7cb27cSAlan Cox 		(void)vm_map_madvise(exec_map, base, base + exec_map_entry_size,
1317c6a4ba5aSMark Johnston 		    MADV_FREE);
1318c6a4ba5aSMark Johnston 		argkva->gen = gen;
1319c6a4ba5aSMark Johnston 	}
1320ec492b13SMark Johnston 	if (!atomic_cmpset_ptr((uintptr_t *)DPCPU_PTR(exec_args_kva),
1321ec492b13SMark Johnston 	    (uintptr_t)NULL, (uintptr_t)argkva)) {
1322ec492b13SMark Johnston 		mtx_lock(&exec_args_kva_mtx);
1323ec492b13SMark Johnston 		SLIST_INSERT_HEAD(&exec_args_kva_freelist, argkva, next);
1324ec492b13SMark Johnston 		wakeup_one(&exec_args_kva_freelist);
1325ec492b13SMark Johnston 		mtx_unlock(&exec_args_kva_mtx);
1326ec492b13SMark Johnston 	}
1327ec492b13SMark Johnston }
1328ec492b13SMark Johnston 
1329c6a4ba5aSMark Johnston static void
1330c6a4ba5aSMark Johnston exec_free_args_kva(void *cookie)
1331c6a4ba5aSMark Johnston {
1332c6a4ba5aSMark Johnston 
1333c6a4ba5aSMark Johnston 	exec_release_args_kva(cookie, exec_args_gen);
1334c6a4ba5aSMark Johnston }
1335c6a4ba5aSMark Johnston 
1336c6a4ba5aSMark Johnston static void
1337c6a4ba5aSMark Johnston exec_args_kva_lowmem(void *arg __unused)
1338c6a4ba5aSMark Johnston {
1339c6a4ba5aSMark Johnston 	SLIST_HEAD(, exec_args_kva) head;
1340c6a4ba5aSMark Johnston 	struct exec_args_kva *argkva;
1341c6a4ba5aSMark Johnston 	u_int gen;
1342c6a4ba5aSMark Johnston 	int i;
1343c6a4ba5aSMark Johnston 
1344c6a4ba5aSMark Johnston 	gen = atomic_fetchadd_int(&exec_args_gen, 1) + 1;
1345c6a4ba5aSMark Johnston 
1346c6a4ba5aSMark Johnston 	/*
1347c6a4ba5aSMark Johnston 	 * Force an madvise of each KVA range. Any currently allocated ranges
1348c6a4ba5aSMark Johnston 	 * will have MADV_FREE applied once they are freed.
1349c6a4ba5aSMark Johnston 	 */
1350c6a4ba5aSMark Johnston 	SLIST_INIT(&head);
1351c6a4ba5aSMark Johnston 	mtx_lock(&exec_args_kva_mtx);
1352c6a4ba5aSMark Johnston 	SLIST_SWAP(&head, &exec_args_kva_freelist, exec_args_kva);
1353c6a4ba5aSMark Johnston 	mtx_unlock(&exec_args_kva_mtx);
1354c6a4ba5aSMark Johnston 	while ((argkva = SLIST_FIRST(&head)) != NULL) {
1355c6a4ba5aSMark Johnston 		SLIST_REMOVE_HEAD(&head, next);
1356c6a4ba5aSMark Johnston 		exec_release_args_kva(argkva, gen);
1357c6a4ba5aSMark Johnston 	}
1358c6a4ba5aSMark Johnston 
1359c6a4ba5aSMark Johnston 	CPU_FOREACH(i) {
1360c6a4ba5aSMark Johnston 		argkva = (void *)atomic_readandclear_ptr(
1361c6a4ba5aSMark Johnston 		    (uintptr_t *)DPCPU_ID_PTR(i, exec_args_kva));
1362c6a4ba5aSMark Johnston 		if (argkva != NULL)
1363c6a4ba5aSMark Johnston 			exec_release_args_kva(argkva, gen);
1364c6a4ba5aSMark Johnston 	}
1365c6a4ba5aSMark Johnston }
1366c6a4ba5aSMark Johnston EVENTHANDLER_DEFINE(vm_lowmem, exec_args_kva_lowmem, NULL,
1367c6a4ba5aSMark Johnston     EVENTHANDLER_PRI_ANY);
1368c6a4ba5aSMark Johnston 
13692af6e14dSAlan Cox /*
13702af6e14dSAlan Cox  * Allocate temporary demand-paged, zero-filled memory for the file name,
1371ec492b13SMark Johnston  * argument, and environment strings.
13722af6e14dSAlan Cox  */
13732af6e14dSAlan Cox int
13742af6e14dSAlan Cox exec_alloc_args(struct image_args *args)
13752af6e14dSAlan Cox {
13762af6e14dSAlan Cox 
1377ec492b13SMark Johnston 	args->buf = (char *)exec_alloc_args_kva(&args->bufkva);
1378ec492b13SMark Johnston 	return (0);
13792af6e14dSAlan Cox }
13802af6e14dSAlan Cox 
138169a8f9e3SAlan Cox void
1382610ecfe0SMaxim Sobolev exec_free_args(struct image_args *args)
1383610ecfe0SMaxim Sobolev {
1384610ecfe0SMaxim Sobolev 
138569a8f9e3SAlan Cox 	if (args->buf != NULL) {
1386ec492b13SMark Johnston 		exec_free_args_kva(args->bufkva);
1387610ecfe0SMaxim Sobolev 		args->buf = NULL;
1388610ecfe0SMaxim Sobolev 	}
1389a14a9498SAlan Cox 	if (args->fname_buf != NULL) {
1390a14a9498SAlan Cox 		free(args->fname_buf, M_TEMP);
1391a14a9498SAlan Cox 		args->fname_buf = NULL;
1392a14a9498SAlan Cox 	}
1393457f7e23SEd Schouten 	if (args->fdp != NULL)
1394457f7e23SEd Schouten 		fdescfree_remapped(args->fdp);
1395610ecfe0SMaxim Sobolev }
1396610ecfe0SMaxim Sobolev 
139726f9a767SRodney W. Grimes /*
1398f373437aSBrooks Davis  * A set to functions to fill struct image args.
1399f373437aSBrooks Davis  *
1400f373437aSBrooks Davis  * NOTE: exec_args_add_fname() must be called (possibly with a NULL
1401f373437aSBrooks Davis  * fname) before the other functions.  All exec_args_add_arg() calls must
1402f373437aSBrooks Davis  * be made before any exec_args_add_env() calls.  exec_args_adjust_args()
1403f373437aSBrooks Davis  * may be called any time after exec_args_add_fname().
1404f373437aSBrooks Davis  *
1405f373437aSBrooks Davis  * exec_args_add_fname() - install path to be executed
1406f373437aSBrooks Davis  * exec_args_add_arg() - append an argument string
1407f373437aSBrooks Davis  * exec_args_add_env() - append an env string
1408f373437aSBrooks Davis  * exec_args_adjust_args() - adjust location of the argument list to
1409f373437aSBrooks Davis  *                           allow new arguments to be prepended
1410f373437aSBrooks Davis  */
1411f373437aSBrooks Davis int
1412f373437aSBrooks Davis exec_args_add_fname(struct image_args *args, const char *fname,
1413f373437aSBrooks Davis     enum uio_seg segflg)
1414f373437aSBrooks Davis {
1415f373437aSBrooks Davis 	int error;
1416f373437aSBrooks Davis 	size_t length;
1417f373437aSBrooks Davis 
1418f373437aSBrooks Davis 	KASSERT(args->fname == NULL, ("fname already appended"));
1419f373437aSBrooks Davis 	KASSERT(args->endp == NULL, ("already appending to args"));
1420f373437aSBrooks Davis 
1421f373437aSBrooks Davis 	if (fname != NULL) {
1422f373437aSBrooks Davis 		args->fname = args->buf;
1423f373437aSBrooks Davis 		error = segflg == UIO_SYSSPACE ?
1424f373437aSBrooks Davis 		    copystr(fname, args->fname, PATH_MAX, &length) :
1425f373437aSBrooks Davis 		    copyinstr(fname, args->fname, PATH_MAX, &length);
1426f373437aSBrooks Davis 		if (error != 0)
1427f373437aSBrooks Davis 			return (error == ENAMETOOLONG ? E2BIG : error);
1428f373437aSBrooks Davis 	} else
1429f373437aSBrooks Davis 		length = 0;
1430f373437aSBrooks Davis 
1431f373437aSBrooks Davis 	/* Set up for _arg_*()/_env_*() */
1432f373437aSBrooks Davis 	args->endp = args->buf + length;
1433f373437aSBrooks Davis 	/* begin_argv must be set and kept updated */
1434f373437aSBrooks Davis 	args->begin_argv = args->endp;
1435f373437aSBrooks Davis 	KASSERT(exec_map_entry_size - length >= ARG_MAX,
1436f373437aSBrooks Davis 	    ("too little space remaining for arguments %zu < %zu",
1437f373437aSBrooks Davis 	    exec_map_entry_size - length, (size_t)ARG_MAX));
1438f373437aSBrooks Davis 	args->stringspace = ARG_MAX;
1439f373437aSBrooks Davis 
1440f373437aSBrooks Davis 	return (0);
1441f373437aSBrooks Davis }
1442f373437aSBrooks Davis 
1443f373437aSBrooks Davis static int
1444f373437aSBrooks Davis exec_args_add_str(struct image_args *args, const char *str,
1445f373437aSBrooks Davis     enum uio_seg segflg, int *countp)
1446f373437aSBrooks Davis {
1447f373437aSBrooks Davis 	int error;
1448f373437aSBrooks Davis 	size_t length;
1449f373437aSBrooks Davis 
1450f373437aSBrooks Davis 	KASSERT(args->endp != NULL, ("endp not initialized"));
1451f373437aSBrooks Davis 	KASSERT(args->begin_argv != NULL, ("begin_argp not initialized"));
1452f373437aSBrooks Davis 
1453f373437aSBrooks Davis 	error = (segflg == UIO_SYSSPACE) ?
1454f373437aSBrooks Davis 	    copystr(str, args->endp, args->stringspace, &length) :
1455f373437aSBrooks Davis 	    copyinstr(str, args->endp, args->stringspace, &length);
1456f373437aSBrooks Davis 	if (error != 0)
1457f373437aSBrooks Davis 		return (error == ENAMETOOLONG ? E2BIG : error);
1458f373437aSBrooks Davis 	args->stringspace -= length;
1459f373437aSBrooks Davis 	args->endp += length;
1460f373437aSBrooks Davis 	(*countp)++;
1461f373437aSBrooks Davis 
1462f373437aSBrooks Davis 	return (0);
1463f373437aSBrooks Davis }
1464f373437aSBrooks Davis 
1465f373437aSBrooks Davis int
1466f373437aSBrooks Davis exec_args_add_arg(struct image_args *args, const char *argp,
1467f373437aSBrooks Davis     enum uio_seg segflg)
1468f373437aSBrooks Davis {
1469f373437aSBrooks Davis 
1470f373437aSBrooks Davis 	KASSERT(args->envc == 0, ("appending args after env"));
1471f373437aSBrooks Davis 
1472f373437aSBrooks Davis 	return (exec_args_add_str(args, argp, segflg, &args->argc));
1473f373437aSBrooks Davis }
1474f373437aSBrooks Davis 
1475f373437aSBrooks Davis int
1476f373437aSBrooks Davis exec_args_add_env(struct image_args *args, const char *envp,
1477f373437aSBrooks Davis     enum uio_seg segflg)
1478f373437aSBrooks Davis {
1479f373437aSBrooks Davis 
1480f373437aSBrooks Davis 	if (args->envc == 0)
1481f373437aSBrooks Davis 		args->begin_envv = args->endp;
1482f373437aSBrooks Davis 
1483f373437aSBrooks Davis 	return (exec_args_add_str(args, envp, segflg, &args->envc));
1484f373437aSBrooks Davis }
1485f373437aSBrooks Davis 
1486f373437aSBrooks Davis int
1487f373437aSBrooks Davis exec_args_adjust_args(struct image_args *args, size_t consume, ssize_t extend)
1488f373437aSBrooks Davis {
1489f373437aSBrooks Davis 	ssize_t offset;
1490f373437aSBrooks Davis 
1491f373437aSBrooks Davis 	KASSERT(args->endp != NULL, ("endp not initialized"));
1492f373437aSBrooks Davis 	KASSERT(args->begin_argv != NULL, ("begin_argp not initialized"));
1493f373437aSBrooks Davis 
1494f373437aSBrooks Davis 	offset = extend - consume;
1495f373437aSBrooks Davis 	if (args->stringspace < offset)
1496f373437aSBrooks Davis 		return (E2BIG);
1497f373437aSBrooks Davis 	memmove(args->begin_argv + extend, args->begin_argv + consume,
1498f373437aSBrooks Davis 	    args->endp - args->begin_argv + consume);
1499f373437aSBrooks Davis 	if (args->envc > 0)
1500f373437aSBrooks Davis 		args->begin_envv += offset;
1501f373437aSBrooks Davis 	args->endp += offset;
1502f373437aSBrooks Davis 	args->stringspace -= offset;
1503f373437aSBrooks Davis 	return (0);
1504f373437aSBrooks Davis }
1505f373437aSBrooks Davis 
1506f373437aSBrooks Davis char *
1507f373437aSBrooks Davis exec_args_get_begin_envv(struct image_args *args)
1508f373437aSBrooks Davis {
1509f373437aSBrooks Davis 
1510f373437aSBrooks Davis 	KASSERT(args->endp != NULL, ("endp not initialized"));
1511f373437aSBrooks Davis 
1512f373437aSBrooks Davis 	if (args->envc > 0)
1513f373437aSBrooks Davis 		return (args->begin_envv);
1514f373437aSBrooks Davis 	return (args->endp);
1515f373437aSBrooks Davis }
1516f373437aSBrooks Davis 
1517f373437aSBrooks Davis /*
1518873fbcd7SRobert Watson  * Copy strings out to the new process address space, constructing new arg
1519873fbcd7SRobert Watson  * and env vector tables. Return a pointer to the base so that it can be used
1520873fbcd7SRobert Watson  * as the initial stack pointer.
152126f9a767SRodney W. Grimes  */
152203b0d68cSJohn Baldwin int
152331174518SJohn Baldwin exec_copyout_strings(struct image_params *imgp, uintptr_t *stack_base)
152426f9a767SRodney W. Grimes {
152526f9a767SRodney W. Grimes 	int argc, envc;
152626f9a767SRodney W. Grimes 	char **vectp;
152788b124ceSKonstantin Belousov 	char *stringp;
152831174518SJohn Baldwin 	uintptr_t destp, ustringp;
152993f6448cSDavid Greenman 	struct ps_strings *arginfo;
1530f3bec5d7SJake Burkholder 	struct proc *p;
15313ff06357SKonstantin Belousov 	size_t execpath_len;
153203b0d68cSJohn Baldwin 	int error, szsigcode, szps;
1533ee235befSKonstantin Belousov 	char canary[sizeof(long) * 8];
153426f9a767SRodney W. Grimes 
1535ee235befSKonstantin Belousov 	szps = sizeof(pagesizes[0]) * MAXPAGESIZES;
153626f9a767SRodney W. Grimes 	/*
153726f9a767SRodney W. Grimes 	 * Calculate string base and vector table pointers.
1538d66a5066SPeter Wemm 	 * Also deal with signal trampoline code for this exec type.
153926f9a767SRodney W. Grimes 	 */
15403ff06357SKonstantin Belousov 	if (imgp->execpath != NULL && imgp->auxargs != NULL)
15413ff06357SKonstantin Belousov 		execpath_len = strlen(imgp->execpath) + 1;
15423ff06357SKonstantin Belousov 	else
15433ff06357SKonstantin Belousov 		execpath_len = 0;
1544f3bec5d7SJake Burkholder 	p = imgp->proc;
1545f3bec5d7SJake Burkholder 	szsigcode = 0;
154605ba50f5SJake Burkholder 	arginfo = (struct ps_strings *)p->p_sysent->sv_psstrings;
15476297a3d8SKonstantin Belousov 	if (p->p_sysent->sv_sigcode_base == 0) {
1548f3bec5d7SJake Burkholder 		if (p->p_sysent->sv_szsigcode != NULL)
1549f3bec5d7SJake Burkholder 			szsigcode = *(p->p_sysent->sv_szsigcode);
15506297a3d8SKonstantin Belousov 	}
155188b124ceSKonstantin Belousov 	destp =	(uintptr_t)arginfo;
15521ed012f9SPeter Wemm 
155326f9a767SRodney W. Grimes 	/*
1554d66a5066SPeter Wemm 	 * install sigcode
1555d66a5066SPeter Wemm 	 */
155688b124ceSKonstantin Belousov 	if (szsigcode != 0) {
155788b124ceSKonstantin Belousov 		destp -= szsigcode;
155888b124ceSKonstantin Belousov 		destp = rounddown2(destp, sizeof(void *));
155903b0d68cSJohn Baldwin 		error = copyout(p->p_sysent->sv_sigcode, (void *)destp,
156003b0d68cSJohn Baldwin 		    szsigcode);
156103b0d68cSJohn Baldwin 		if (error != 0)
156203b0d68cSJohn Baldwin 			return (error);
156388b124ceSKonstantin Belousov 	}
1564d66a5066SPeter Wemm 
1565d66a5066SPeter Wemm 	/*
15663ff06357SKonstantin Belousov 	 * Copy the image path for the rtld.
15673ff06357SKonstantin Belousov 	 */
15683ff06357SKonstantin Belousov 	if (execpath_len != 0) {
156988b124ceSKonstantin Belousov 		destp -= execpath_len;
1570d92da759SBrooks Davis 		destp = rounddown2(destp, sizeof(void *));
157188b124ceSKonstantin Belousov 		imgp->execpathp = destp;
157203b0d68cSJohn Baldwin 		error = copyout(imgp->execpath, (void *)destp, execpath_len);
157303b0d68cSJohn Baldwin 		if (error != 0)
157403b0d68cSJohn Baldwin 			return (error);
15753ff06357SKonstantin Belousov 	}
15763ff06357SKonstantin Belousov 
15773ff06357SKonstantin Belousov 	/*
1578ee235befSKonstantin Belousov 	 * Prepare the canary for SSP.
1579ee235befSKonstantin Belousov 	 */
1580ee235befSKonstantin Belousov 	arc4rand(canary, sizeof(canary), 0);
158188b124ceSKonstantin Belousov 	destp -= sizeof(canary);
158288b124ceSKonstantin Belousov 	imgp->canary = destp;
158303b0d68cSJohn Baldwin 	error = copyout(canary, (void *)destp, sizeof(canary));
158403b0d68cSJohn Baldwin 	if (error != 0)
158503b0d68cSJohn Baldwin 		return (error);
1586ee235befSKonstantin Belousov 	imgp->canarylen = sizeof(canary);
1587ee235befSKonstantin Belousov 
1588ee235befSKonstantin Belousov 	/*
1589ee235befSKonstantin Belousov 	 * Prepare the pagesizes array.
1590ee235befSKonstantin Belousov 	 */
159188b124ceSKonstantin Belousov 	destp -= szps;
159288b124ceSKonstantin Belousov 	destp = rounddown2(destp, sizeof(void *));
159388b124ceSKonstantin Belousov 	imgp->pagesizes = destp;
159403b0d68cSJohn Baldwin 	error = copyout(pagesizes, (void *)destp, szps);
159503b0d68cSJohn Baldwin 	if (error != 0)
159603b0d68cSJohn Baldwin 		return (error);
1597ee235befSKonstantin Belousov 	imgp->pagesizeslen = szps;
1598ee235befSKonstantin Belousov 
159931174518SJohn Baldwin 	/*
160031174518SJohn Baldwin 	 * Allocate room for the argument and environment strings.
160131174518SJohn Baldwin 	 */
160288b124ceSKonstantin Belousov 	destp -= ARG_MAX - imgp->args->stringspace;
160388b124ceSKonstantin Belousov 	destp = rounddown2(destp, sizeof(void *));
160431174518SJohn Baldwin 	ustringp = destp;
160588b124ceSKonstantin Belousov 
1606fc83c5a7SKonstantin Belousov 	if (imgp->sysent->sv_stackgap != NULL)
160731174518SJohn Baldwin 		imgp->sysent->sv_stackgap(imgp, &destp);
1608fc83c5a7SKonstantin Belousov 
160903b0d68cSJohn Baldwin 	if (imgp->auxargs) {
1610d8010b11SJohn Baldwin 		/*
1611d8010b11SJohn Baldwin 		 * Allocate room on the stack for the ELF auxargs
1612d8010b11SJohn Baldwin 		 * array.  It has up to AT_COUNT entries.
1613d8010b11SJohn Baldwin 		 */
1614d8010b11SJohn Baldwin 		destp -= AT_COUNT * sizeof(Elf_Auxinfo);
1615d8010b11SJohn Baldwin 		destp = rounddown2(destp, sizeof(void *));
161603b0d68cSJohn Baldwin 	}
161726f9a767SRodney W. Grimes 
161831174518SJohn Baldwin 	vectp = (char **)destp;
161931174518SJohn Baldwin 
162026f9a767SRodney W. Grimes 	/*
162173c8686eSJohn Baldwin 	 * Allocate room for the argv[] and env vectors including the
162273c8686eSJohn Baldwin 	 * terminating NULL pointers.
162373c8686eSJohn Baldwin 	 */
162473c8686eSJohn Baldwin 	vectp -= imgp->args->argc + 1 + imgp->args->envc + 1;
162573c8686eSJohn Baldwin 
162673c8686eSJohn Baldwin 	/*
162726f9a767SRodney W. Grimes 	 * vectp also becomes our initial stack base
162826f9a767SRodney W. Grimes 	 */
162931174518SJohn Baldwin 	*stack_base = (uintptr_t)vectp;
163026f9a767SRodney W. Grimes 
1631610ecfe0SMaxim Sobolev 	stringp = imgp->args->begin_argv;
1632610ecfe0SMaxim Sobolev 	argc = imgp->args->argc;
1633610ecfe0SMaxim Sobolev 	envc = imgp->args->envc;
163426f9a767SRodney W. Grimes 
163593f6448cSDavid Greenman 	/*
16363aed948bSDavid Greenman 	 * Copy out strings - arguments and environment.
163793f6448cSDavid Greenman 	 */
163831174518SJohn Baldwin 	error = copyout(stringp, (void *)ustringp,
163903b0d68cSJohn Baldwin 	    ARG_MAX - imgp->args->stringspace);
164003b0d68cSJohn Baldwin 	if (error != 0)
164103b0d68cSJohn Baldwin 		return (error);
164293f6448cSDavid Greenman 
164393f6448cSDavid Greenman 	/*
16443aed948bSDavid Greenman 	 * Fill in "ps_strings" struct for ps, w, etc.
16453aed948bSDavid Greenman 	 */
164603b0d68cSJohn Baldwin 	if (suword(&arginfo->ps_argvstr, (long)(intptr_t)vectp) != 0 ||
164703b0d68cSJohn Baldwin 	    suword32(&arginfo->ps_nargvstr, argc) != 0)
164803b0d68cSJohn Baldwin 		return (EFAULT);
16493aed948bSDavid Greenman 
16503aed948bSDavid Greenman 	/*
16513aed948bSDavid Greenman 	 * Fill in argument portion of vector table.
165293f6448cSDavid Greenman 	 */
165326f9a767SRodney W. Grimes 	for (; argc > 0; --argc) {
165431174518SJohn Baldwin 		if (suword(vectp++, ustringp) != 0)
165503b0d68cSJohn Baldwin 			return (EFAULT);
16563aed948bSDavid Greenman 		while (*stringp++ != 0)
165731174518SJohn Baldwin 			ustringp++;
165831174518SJohn Baldwin 		ustringp++;
165926f9a767SRodney W. Grimes 	}
166026f9a767SRodney W. Grimes 
16611a6e52d0SJeroen Ruigrok van der Werven 	/* a null vector table pointer separates the argp's from the envp's */
166203b0d68cSJohn Baldwin 	if (suword(vectp++, 0) != 0)
166303b0d68cSJohn Baldwin 		return (EFAULT);
166426f9a767SRodney W. Grimes 
166503b0d68cSJohn Baldwin 	if (suword(&arginfo->ps_envstr, (long)(intptr_t)vectp) != 0 ||
166603b0d68cSJohn Baldwin 	    suword32(&arginfo->ps_nenvstr, envc) != 0)
166703b0d68cSJohn Baldwin 		return (EFAULT);
166893f6448cSDavid Greenman 
166993f6448cSDavid Greenman 	/*
16703aed948bSDavid Greenman 	 * Fill in environment portion of vector table.
167193f6448cSDavid Greenman 	 */
167226f9a767SRodney W. Grimes 	for (; envc > 0; --envc) {
167331174518SJohn Baldwin 		if (suword(vectp++, ustringp) != 0)
167403b0d68cSJohn Baldwin 			return (EFAULT);
16753aed948bSDavid Greenman 		while (*stringp++ != 0)
167631174518SJohn Baldwin 			ustringp++;
167731174518SJohn Baldwin 		ustringp++;
167826f9a767SRodney W. Grimes 	}
167926f9a767SRodney W. Grimes 
168026f9a767SRodney W. Grimes 	/* end of vector table is a null pointer */
168103b0d68cSJohn Baldwin 	if (suword(vectp, 0) != 0)
168203b0d68cSJohn Baldwin 		return (EFAULT);
168326f9a767SRodney W. Grimes 
1684d8010b11SJohn Baldwin 	if (imgp->auxargs) {
1685d8010b11SJohn Baldwin 		vectp++;
1686d8010b11SJohn Baldwin 		error = imgp->sysent->sv_copyout_auxargs(imgp,
1687d8010b11SJohn Baldwin 		    (uintptr_t)vectp);
1688d8010b11SJohn Baldwin 		if (error != 0)
1689d8010b11SJohn Baldwin 			return (error);
1690d8010b11SJohn Baldwin 	}
1691d8010b11SJohn Baldwin 
169203b0d68cSJohn Baldwin 	return (0);
169326f9a767SRodney W. Grimes }
169426f9a767SRodney W. Grimes 
169526f9a767SRodney W. Grimes /*
169626f9a767SRodney W. Grimes  * Check permissions of file to execute.
1697cf64863aSRobert Watson  *	Called with imgp->vp locked.
169826f9a767SRodney W. Grimes  *	Return 0 for success or error code on failure.
169926f9a767SRodney W. Grimes  */
1700c8a79999SPeter Wemm int
17013e85b721SEd Maste exec_check_permissions(struct image_params *imgp)
170226f9a767SRodney W. Grimes {
1703c52007c2SDavid Greenman 	struct vnode *vp = imgp->vp;
1704c52007c2SDavid Greenman 	struct vattr *attr = imgp->attr;
1705a854ed98SJohn Baldwin 	struct thread *td;
170678022527SKonstantin Belousov 	int error;
170726f9a767SRodney W. Grimes 
17086617724cSJeff Roberson 	td = curthread;
1709339b79b9SRobert Watson 
1710ec35c2afSRobert Watson 	/* Get file attributes */
17110359a12eSAttilio Rao 	error = VOP_GETATTR(vp, attr, td->td_ucred);
1712ec35c2afSRobert Watson 	if (error)
1713ec35c2afSRobert Watson 		return (error);
1714ec35c2afSRobert Watson 
1715339b79b9SRobert Watson #ifdef MAC
171630d239bcSRobert Watson 	error = mac_vnode_check_exec(td->td_ucred, imgp->vp, imgp);
1717339b79b9SRobert Watson 	if (error)
1718339b79b9SRobert Watson 		return (error);
1719339b79b9SRobert Watson #endif
1720339b79b9SRobert Watson 
172126f9a767SRodney W. Grimes 	/*
1722de478dd4SJaakko Heinonen 	 * 1) Check if file execution is disabled for the filesystem that
1723de478dd4SJaakko Heinonen 	 *    this file resides on.
1724de478dd4SJaakko Heinonen 	 * 2) Ensure that at least one execute bit is on. Otherwise, a
1725de478dd4SJaakko Heinonen 	 *    privileged user will always succeed, and we don't want this
1726de478dd4SJaakko Heinonen 	 *    to happen unless the file really is executable.
1727de478dd4SJaakko Heinonen 	 * 3) Ensure that the file is a regular file.
172826f9a767SRodney W. Grimes 	 */
1729c52007c2SDavid Greenman 	if ((vp->v_mount->mnt_flag & MNT_NOEXEC) ||
1730de478dd4SJaakko Heinonen 	    (attr->va_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) == 0 ||
1731a854ed98SJohn Baldwin 	    (attr->va_type != VREG))
173226f9a767SRodney W. Grimes 		return (EACCES);
173326f9a767SRodney W. Grimes 
173426f9a767SRodney W. Grimes 	/*
173526f9a767SRodney W. Grimes 	 * Zero length files can't be exec'd
173626f9a767SRodney W. Grimes 	 */
173726f9a767SRodney W. Grimes 	if (attr->va_size == 0)
173826f9a767SRodney W. Grimes 		return (ENOEXEC);
173926f9a767SRodney W. Grimes 
174026f9a767SRodney W. Grimes 	/*
174126f9a767SRodney W. Grimes 	 *  Check for execute permission to file based on current credentials.
174226f9a767SRodney W. Grimes 	 */
1743a854ed98SJohn Baldwin 	error = VOP_ACCESS(vp, VEXEC, td->td_ucred, td);
174426f9a767SRodney W. Grimes 	if (error)
174526f9a767SRodney W. Grimes 		return (error);
174626f9a767SRodney W. Grimes 
17476d5a0a8cSDavid Greenman 	/*
17486d5a0a8cSDavid Greenman 	 * Check number of open-for-writes on the file and deny execution
17496d5a0a8cSDavid Greenman 	 * if there are any.
175078022527SKonstantin Belousov 	 *
175178022527SKonstantin Belousov 	 * Add a text reference now so no one can write to the
175278022527SKonstantin Belousov 	 * executable while we're activating it.
175378022527SKonstantin Belousov 	 *
175478022527SKonstantin Belousov 	 * Remember if this was set before and unset it in case this is not
175578022527SKonstantin Belousov 	 * actually an executable image.
17566d5a0a8cSDavid Greenman 	 */
175778022527SKonstantin Belousov 	error = VOP_SET_TEXT(vp);
1758140dedb8SKonstantin Belousov 	if (error != 0)
1759140dedb8SKonstantin Belousov 		return (error);
176078022527SKonstantin Belousov 	imgp->textset = true;
17616d5a0a8cSDavid Greenman 
17626d5a0a8cSDavid Greenman 	/*
17636d5a0a8cSDavid Greenman 	 * Call filesystem specific open routine (which does nothing in the
17646d5a0a8cSDavid Greenman 	 * general case).
17656d5a0a8cSDavid Greenman 	 */
17669e223287SKonstantin Belousov 	error = VOP_OPEN(vp, FREAD, td->td_ucred, td, NULL);
17679a75ea23SKonstantin Belousov 	if (error == 0)
17689a75ea23SKonstantin Belousov 		imgp->opened = 1;
176926f9a767SRodney W. Grimes 	return (error);
1770df8bae1dSRodney W. Grimes }
1771aa855a59SPeter Wemm 
1772aa855a59SPeter Wemm /*
1773aa855a59SPeter Wemm  * Exec handler registration
1774aa855a59SPeter Wemm  */
1775aa855a59SPeter Wemm int
17763e85b721SEd Maste exec_register(const struct execsw *execsw_arg)
1777aa855a59SPeter Wemm {
1778aa855a59SPeter Wemm 	const struct execsw **es, **xs, **newexecsw;
1779d821d364SPedro F. Giffuni 	u_int count = 2;	/* New slot and trailing NULL */
1780aa855a59SPeter Wemm 
1781aa855a59SPeter Wemm 	if (execsw)
1782aa855a59SPeter Wemm 		for (es = execsw; *es; es++)
1783aa855a59SPeter Wemm 			count++;
1784a163d034SWarner Losh 	newexecsw = malloc(count * sizeof(*es), M_TEMP, M_WAITOK);
1785aa855a59SPeter Wemm 	xs = newexecsw;
1786aa855a59SPeter Wemm 	if (execsw)
1787aa855a59SPeter Wemm 		for (es = execsw; *es; es++)
1788aa855a59SPeter Wemm 			*xs++ = *es;
1789aa855a59SPeter Wemm 	*xs++ = execsw_arg;
1790aa855a59SPeter Wemm 	*xs = NULL;
1791aa855a59SPeter Wemm 	if (execsw)
1792aa855a59SPeter Wemm 		free(execsw, M_TEMP);
1793aa855a59SPeter Wemm 	execsw = newexecsw;
1794a7cddfedSJake Burkholder 	return (0);
1795aa855a59SPeter Wemm }
1796aa855a59SPeter Wemm 
1797aa855a59SPeter Wemm int
17983e85b721SEd Maste exec_unregister(const struct execsw *execsw_arg)
1799aa855a59SPeter Wemm {
1800aa855a59SPeter Wemm 	const struct execsw **es, **xs, **newexecsw;
1801aa855a59SPeter Wemm 	int count = 1;
1802aa855a59SPeter Wemm 
1803aa855a59SPeter Wemm 	if (execsw == NULL)
1804aa855a59SPeter Wemm 		panic("unregister with no handlers left?\n");
1805aa855a59SPeter Wemm 
1806aa855a59SPeter Wemm 	for (es = execsw; *es; es++) {
1807aa855a59SPeter Wemm 		if (*es == execsw_arg)
1808aa855a59SPeter Wemm 			break;
1809aa855a59SPeter Wemm 	}
1810aa855a59SPeter Wemm 	if (*es == NULL)
1811a7cddfedSJake Burkholder 		return (ENOENT);
1812aa855a59SPeter Wemm 	for (es = execsw; *es; es++)
1813aa855a59SPeter Wemm 		if (*es != execsw_arg)
1814aa855a59SPeter Wemm 			count++;
1815a163d034SWarner Losh 	newexecsw = malloc(count * sizeof(*es), M_TEMP, M_WAITOK);
1816aa855a59SPeter Wemm 	xs = newexecsw;
1817aa855a59SPeter Wemm 	for (es = execsw; *es; es++)
1818aa855a59SPeter Wemm 		if (*es != execsw_arg)
1819aa855a59SPeter Wemm 			*xs++ = *es;
1820aa855a59SPeter Wemm 	*xs = NULL;
1821aa855a59SPeter Wemm 	if (execsw)
1822aa855a59SPeter Wemm 		free(execsw, M_TEMP);
1823aa855a59SPeter Wemm 	execsw = newexecsw;
1824a7cddfedSJake Burkholder 	return (0);
1825aa855a59SPeter Wemm }
1826