xref: /freebsd/sys/kern/kern_exec.c (revision b05ca4290cae1d8d2548d77385f7b15223428ac7)
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|
126*b05ca429SPawel Biernacki     CTLFLAG_CAPRD|CTLFLAG_MPSAFE, NULL, 0, sysctl_kern_ps_strings, "LU",
127*b05ca429SPawel Biernacki     "Location of process' ps_strings structure");
128486bddb0SDoug Rabson 
1299701cd40SJohn Baldwin /* XXX This should be vm_size_t. */
130ff66f6a4SRobert Watson SYSCTL_PROC(_kern, KERN_USRSTACK, usrstack, CTLTYPE_ULONG|CTLFLAG_RD|
131*b05ca429SPawel Biernacki     CTLFLAG_CAPRD|CTLFLAG_MPSAFE, NULL, 0, sysctl_kern_usrstack, "LU",
132*b05ca429SPawel Biernacki     "Top of process stack");
13399ac3bc8SPeter Wemm 
13453dc58f2SMateusz Guzik SYSCTL_PROC(_kern, OID_AUTO, stackprot, CTLTYPE_INT|CTLFLAG_RD|CTLFLAG_MPSAFE,
135*b05ca429SPawel Biernacki     NULL, 0, sysctl_kern_stackprot, "I",
136*b05ca429SPawel Biernacki     "Stack memory permissions");
1375dadd17bSJake Burkholder 
138b9df5231SPoul-Henning Kamp u_long ps_arg_cache_limit = PAGE_SIZE / 16;
139c3699b5fSPeter Wemm SYSCTL_ULONG(_kern, OID_AUTO, ps_arg_cache_limit, CTLFLAG_RW,
140*b05ca429SPawel Biernacki     &ps_arg_cache_limit, 0,
141*b05ca429SPawel Biernacki     "Process' command line characters cache limit");
142b9df5231SPoul-Henning Kamp 
143eda6009cSKonstantin Belousov static int disallow_high_osrel;
144eda6009cSKonstantin Belousov SYSCTL_INT(_kern, OID_AUTO, disallow_high_osrel, CTLFLAG_RW,
145eda6009cSKonstantin Belousov     &disallow_high_osrel, 0,
146eda6009cSKonstantin Belousov     "Disallow execution of binaries built for higher version of the world");
147eda6009cSKonstantin Belousov 
148878adb85SBjoern A. Zeeb static int map_at_zero = 0;
149af3b2549SHans Petter Selasky SYSCTL_INT(_security_bsd, OID_AUTO, map_at_zero, CTLFLAG_RWTUN, &map_at_zero, 0,
150878adb85SBjoern A. Zeeb     "Permit processes to map an object at virtual address 0.");
151878adb85SBjoern A. Zeeb 
15205ba50f5SJake Burkholder static int
15305ba50f5SJake Burkholder sysctl_kern_ps_strings(SYSCTL_HANDLER_ARGS)
15405ba50f5SJake Burkholder {
15505ba50f5SJake Burkholder 	struct proc *p;
156df7c361eSPeter Wemm 	int error;
15705ba50f5SJake Burkholder 
15805ba50f5SJake Burkholder 	p = curproc;
159a7bc3102SPeter Wemm #ifdef SCTL_MASK32
160a7bc3102SPeter Wemm 	if (req->flags & SCTL_MASK32) {
161df7c361eSPeter Wemm 		unsigned int val;
162df7c361eSPeter Wemm 		val = (unsigned int)p->p_sysent->sv_psstrings;
163df7c361eSPeter Wemm 		error = SYSCTL_OUT(req, &val, sizeof(val));
164df7c361eSPeter Wemm 	} else
165df7c361eSPeter Wemm #endif
166df7c361eSPeter Wemm 		error = SYSCTL_OUT(req, &p->p_sysent->sv_psstrings,
167df7c361eSPeter Wemm 		   sizeof(p->p_sysent->sv_psstrings));
168df7c361eSPeter Wemm 	return error;
16905ba50f5SJake Burkholder }
17005ba50f5SJake Burkholder 
17105ba50f5SJake Burkholder static int
17205ba50f5SJake Burkholder sysctl_kern_usrstack(SYSCTL_HANDLER_ARGS)
17305ba50f5SJake Burkholder {
17405ba50f5SJake Burkholder 	struct proc *p;
175df7c361eSPeter Wemm 	int error;
17605ba50f5SJake Burkholder 
17705ba50f5SJake Burkholder 	p = curproc;
178a7bc3102SPeter Wemm #ifdef SCTL_MASK32
179a7bc3102SPeter Wemm 	if (req->flags & SCTL_MASK32) {
180df7c361eSPeter Wemm 		unsigned int val;
181df7c361eSPeter Wemm 		val = (unsigned int)p->p_sysent->sv_usrstack;
182df7c361eSPeter Wemm 		error = SYSCTL_OUT(req, &val, sizeof(val));
183df7c361eSPeter Wemm 	} else
184df7c361eSPeter Wemm #endif
185df7c361eSPeter Wemm 		error = SYSCTL_OUT(req, &p->p_sysent->sv_usrstack,
186df7c361eSPeter Wemm 		    sizeof(p->p_sysent->sv_usrstack));
187df7c361eSPeter Wemm 	return error;
18805ba50f5SJake Burkholder }
18905ba50f5SJake Burkholder 
1905dadd17bSJake Burkholder static int
1915dadd17bSJake Burkholder sysctl_kern_stackprot(SYSCTL_HANDLER_ARGS)
1925dadd17bSJake Burkholder {
1935dadd17bSJake Burkholder 	struct proc *p;
1945dadd17bSJake Burkholder 
1955dadd17bSJake Burkholder 	p = curproc;
1965dadd17bSJake Burkholder 	return (SYSCTL_OUT(req, &p->p_sysent->sv_stackprot,
1975dadd17bSJake Burkholder 	    sizeof(p->p_sysent->sv_stackprot)));
1985dadd17bSJake Burkholder }
1995dadd17bSJake Burkholder 
20099ac3bc8SPeter Wemm /*
201aa855a59SPeter Wemm  * Each of the items is a pointer to a `const struct execsw', hence the
202aa855a59SPeter Wemm  * double pointer here.
203df8bae1dSRodney W. Grimes  */
204aa855a59SPeter Wemm static const struct execsw **execsw;
20526f9a767SRodney W. Grimes 
206ca46e90eSBruce Evans #ifndef _SYS_SYSPROTO_H_
207ca46e90eSBruce Evans struct execve_args {
208ca46e90eSBruce Evans 	char    *fname;
209ca46e90eSBruce Evans 	char    **argv;
210ca46e90eSBruce Evans 	char    **envv;
211ca46e90eSBruce Evans };
212ca46e90eSBruce Evans #endif
213ca46e90eSBruce Evans 
214ca46e90eSBruce Evans int
2157b445033SKonstantin Belousov sys_execve(struct thread *td, struct execve_args *uap)
216ca46e90eSBruce Evans {
217610ecfe0SMaxim Sobolev 	struct image_args args;
2187b445033SKonstantin Belousov 	struct vmspace *oldvmspace;
2197b445033SKonstantin Belousov 	int error;
220ca46e90eSBruce Evans 
2217b445033SKonstantin Belousov 	error = pre_execve(td, &oldvmspace);
2227b445033SKonstantin Belousov 	if (error != 0)
2237b445033SKonstantin Belousov 		return (error);
224610ecfe0SMaxim Sobolev 	error = exec_copyin_args(&args, uap->fname, UIO_USERSPACE,
225610ecfe0SMaxim Sobolev 	    uap->argv, uap->envv);
226610ecfe0SMaxim Sobolev 	if (error == 0)
227610ecfe0SMaxim Sobolev 		error = kern_execve(td, &args, NULL);
2287b445033SKonstantin Belousov 	post_execve(td, error, oldvmspace);
229610ecfe0SMaxim Sobolev 	return (error);
230ca46e90eSBruce Evans }
231ca46e90eSBruce Evans 
232ca46e90eSBruce Evans #ifndef _SYS_SYSPROTO_H_
233632dbc19SKonstantin Belousov struct fexecve_args {
234632dbc19SKonstantin Belousov 	int	fd;
235632dbc19SKonstantin Belousov 	char	**argv;
236632dbc19SKonstantin Belousov 	char	**envv;
237632dbc19SKonstantin Belousov }
238632dbc19SKonstantin Belousov #endif
239632dbc19SKonstantin Belousov int
2408451d0ddSKip Macy sys_fexecve(struct thread *td, struct fexecve_args *uap)
241632dbc19SKonstantin Belousov {
242632dbc19SKonstantin Belousov 	struct image_args args;
2437b445033SKonstantin Belousov 	struct vmspace *oldvmspace;
2447b445033SKonstantin Belousov 	int error;
245632dbc19SKonstantin Belousov 
2467b445033SKonstantin Belousov 	error = pre_execve(td, &oldvmspace);
2477b445033SKonstantin Belousov 	if (error != 0)
2487b445033SKonstantin Belousov 		return (error);
249632dbc19SKonstantin Belousov 	error = exec_copyin_args(&args, NULL, UIO_SYSSPACE,
250632dbc19SKonstantin Belousov 	    uap->argv, uap->envv);
251632dbc19SKonstantin Belousov 	if (error == 0) {
252632dbc19SKonstantin Belousov 		args.fd = uap->fd;
253632dbc19SKonstantin Belousov 		error = kern_execve(td, &args, NULL);
254632dbc19SKonstantin Belousov 	}
2557b445033SKonstantin Belousov 	post_execve(td, error, oldvmspace);
256632dbc19SKonstantin Belousov 	return (error);
257632dbc19SKonstantin Belousov }
258632dbc19SKonstantin Belousov 
259632dbc19SKonstantin Belousov #ifndef _SYS_SYSPROTO_H_
260ca46e90eSBruce Evans struct __mac_execve_args {
261ca46e90eSBruce Evans 	char	*fname;
262ca46e90eSBruce Evans 	char	**argv;
263ca46e90eSBruce Evans 	char	**envv;
264ca46e90eSBruce Evans 	struct mac	*mac_p;
265ca46e90eSBruce Evans };
266ca46e90eSBruce Evans #endif
267ca46e90eSBruce Evans 
268ca46e90eSBruce Evans int
2697b445033SKonstantin Belousov sys___mac_execve(struct thread *td, struct __mac_execve_args *uap)
270ca46e90eSBruce Evans {
271ca46e90eSBruce Evans #ifdef MAC
272610ecfe0SMaxim Sobolev 	struct image_args args;
2737b445033SKonstantin Belousov 	struct vmspace *oldvmspace;
2747b445033SKonstantin Belousov 	int error;
275610ecfe0SMaxim Sobolev 
2767b445033SKonstantin Belousov 	error = pre_execve(td, &oldvmspace);
2777b445033SKonstantin Belousov 	if (error != 0)
2787b445033SKonstantin Belousov 		return (error);
279610ecfe0SMaxim Sobolev 	error = exec_copyin_args(&args, uap->fname, UIO_USERSPACE,
280610ecfe0SMaxim Sobolev 	    uap->argv, uap->envv);
281610ecfe0SMaxim Sobolev 	if (error == 0)
282610ecfe0SMaxim Sobolev 		error = kern_execve(td, &args, uap->mac_p);
2837b445033SKonstantin Belousov 	post_execve(td, error, oldvmspace);
284610ecfe0SMaxim Sobolev 	return (error);
285ca46e90eSBruce Evans #else
286ca46e90eSBruce Evans 	return (ENOSYS);
287ca46e90eSBruce Evans #endif
288ca46e90eSBruce Evans }
289ca46e90eSBruce Evans 
29084e0b075SDavid Xu int
2917b445033SKonstantin Belousov pre_execve(struct thread *td, struct vmspace **oldvmspace)
292906ac69dSDavid Xu {
2937b445033SKonstantin Belousov 	struct proc *p;
294906ac69dSDavid Xu 	int error;
295906ac69dSDavid Xu 
2967b445033SKonstantin Belousov 	KASSERT(td == curthread, ("non-current thread %p", td));
2977b445033SKonstantin Belousov 	error = 0;
2987b445033SKonstantin Belousov 	p = td->td_proc;
2997b445033SKonstantin Belousov 	if ((p->p_flag & P_HADTHREADS) != 0) {
300906ac69dSDavid Xu 		PROC_LOCK(p);
3017b445033SKonstantin Belousov 		if (thread_single(p, SINGLE_BOUNDARY) != 0)
3027b445033SKonstantin Belousov 			error = ERESTART;
303906ac69dSDavid Xu 		PROC_UNLOCK(p);
304906ac69dSDavid Xu 	}
3057b445033SKonstantin Belousov 	KASSERT(error != 0 || (td->td_pflags & TDP_EXECVMSPC) == 0,
3067b445033SKonstantin Belousov 	    ("nested execve"));
3077b445033SKonstantin Belousov 	*oldvmspace = p->p_vmspace;
3087b445033SKonstantin Belousov 	return (error);
3097b445033SKonstantin Belousov }
310906ac69dSDavid Xu 
3117b445033SKonstantin Belousov void
3127b445033SKonstantin Belousov post_execve(struct thread *td, int error, struct vmspace *oldvmspace)
3137b445033SKonstantin Belousov {
3147b445033SKonstantin Belousov 	struct proc *p;
315906ac69dSDavid Xu 
3167b445033SKonstantin Belousov 	KASSERT(td == curthread, ("non-current thread %p", td));
3177b445033SKonstantin Belousov 	p = td->td_proc;
3187b445033SKonstantin Belousov 	if ((p->p_flag & P_HADTHREADS) != 0) {
319906ac69dSDavid Xu 		PROC_LOCK(p);
320906ac69dSDavid Xu 		/*
321906ac69dSDavid Xu 		 * If success, we upgrade to SINGLE_EXIT state to
322906ac69dSDavid Xu 		 * force other threads to suicide.
323906ac69dSDavid Xu 		 */
324814629ddSEd Schouten 		if (error == EJUSTRETURN)
3256ddcc233SKonstantin Belousov 			thread_single(p, SINGLE_EXIT);
326906ac69dSDavid Xu 		else
3276ddcc233SKonstantin Belousov 			thread_single_end(p, SINGLE_BOUNDARY);
328906ac69dSDavid Xu 		PROC_UNLOCK(p);
329906ac69dSDavid Xu 	}
3307032434eSKonstantin Belousov 	if ((td->td_pflags & TDP_EXECVMSPC) != 0) {
3317b445033SKonstantin Belousov 		KASSERT(p->p_vmspace != oldvmspace,
3327032434eSKonstantin Belousov 		    ("oldvmspace still used"));
3337032434eSKonstantin Belousov 		vmspace_free(oldvmspace);
3347032434eSKonstantin Belousov 		td->td_pflags &= ~TDP_EXECVMSPC;
3357032434eSKonstantin Belousov 	}
3367b445033SKonstantin Belousov }
337906ac69dSDavid Xu 
3387b445033SKonstantin Belousov /*
3397b445033SKonstantin Belousov  * XXX: kern_execve has the astonishing property of not always returning to
3407b445033SKonstantin Belousov  * the caller.  If sufficiently bad things happen during the call to
3417b445033SKonstantin Belousov  * do_execve(), it can end up calling exit1(); as a result, callers must
3427b445033SKonstantin Belousov  * avoid doing anything which they might need to undo (e.g., allocating
3437b445033SKonstantin Belousov  * memory).
3447b445033SKonstantin Belousov  */
3457b445033SKonstantin Belousov int
3467b445033SKonstantin Belousov kern_execve(struct thread *td, struct image_args *args, struct mac *mac_p)
3477b445033SKonstantin Belousov {
3487b445033SKonstantin Belousov 
3497b445033SKonstantin Belousov 	AUDIT_ARG_ARGV(args->begin_argv, args->argc,
350f373437aSBrooks Davis 	    exec_args_get_begin_envv(args) - args->begin_argv);
351f373437aSBrooks Davis 	AUDIT_ARG_ENVV(exec_args_get_begin_envv(args), args->envc,
352f373437aSBrooks Davis 	    args->endp - exec_args_get_begin_envv(args));
3537b445033SKonstantin Belousov 	return (do_execve(td, args, mac_p));
354906ac69dSDavid Xu }
355906ac69dSDavid Xu 
35626f9a767SRodney W. Grimes /*
357450ffb44SRobert Watson  * In-kernel implementation of execve().  All arguments are assumed to be
358450ffb44SRobert Watson  * userspace pointers from the passed thread.
35926f9a767SRodney W. Grimes  */
360450ffb44SRobert Watson static int
3613e85b721SEd Maste do_execve(struct thread *td, struct image_args *args, struct mac *mac_p)
362df8bae1dSRodney W. Grimes {
363b40ce416SJulian Elischer 	struct proc *p = td->td_proc;
36469c9eff8SEd Schouten 	struct nameidata nd;
365881010f0SBryan Drewery 	struct ucred *oldcred;
366350d5181SMateusz Guzik 	struct uidinfo *euip = NULL;
36731174518SJohn Baldwin 	uintptr_t stack_base;
368c52007c2SDavid Greenman 	struct image_params image_params, *imgp;
3699f5c1d19SDiomidis Spinellis 	struct vattr attr;
3704d77a549SAlfred Perlstein 	int (*img_first)(struct image_params *);
37169be5db9SAlfred Perlstein 	struct pargs *oldargs = NULL, *newargs = NULL;
372cda68844SMateusz Guzik 	struct sigacts *oldsigacts = NULL, *newsigacts = NULL;
3736c84de02SJohn Baldwin #ifdef KTRACE
3746c84de02SJohn Baldwin 	struct vnode *tracevp = NULL;
375a5881ea5SJohn Baldwin 	struct ucred *tracecred = NULL;
3766c84de02SJohn Baldwin #endif
37761617058SMateusz Guzik 	struct vnode *oldtextvp = NULL, *newtextvp;
378d06c0d4dSRobert Watson 	int credential_changing;
379ccafe7ebSRobert Watson #ifdef MAC
3806356dba0SRobert Watson 	struct label *interpvplabel = NULL;
381eca8a663SRobert Watson 	int will_transition;
382ccafe7ebSRobert Watson #endif
38315139246SJoseph Koshy #ifdef HWPMC_HOOKS
38415139246SJoseph Koshy 	struct pmckern_procexec pe;
38515139246SJoseph Koshy #endif
38601a2b567SKonstantin Belousov 	int error, i, orig_osrel;
38701a2b567SKonstantin Belousov 	uint32_t orig_fctl0;
388632dbc19SKonstantin Belousov 	static const char fexecv_proc_title[] = "(fexecv)";
38926f9a767SRodney W. Grimes 
390c52007c2SDavid Greenman 	imgp = &image_params;
391df8bae1dSRodney W. Grimes 
3929ca45e81SDag-Erling Smørgrav 	/*
3939ca45e81SDag-Erling Smørgrav 	 * Lock the process and set the P_INEXEC flag to indicate that
3949ca45e81SDag-Erling Smørgrav 	 * it should be left alone until we're done here.  This is
3959ca45e81SDag-Erling Smørgrav 	 * necessary to avoid race conditions - e.g. in ptrace() -
3969ca45e81SDag-Erling Smørgrav 	 * that might allow a local user to illicitly obtain elevated
3979ca45e81SDag-Erling Smørgrav 	 * privileges.
3989ca45e81SDag-Erling Smørgrav 	 */
3999ca45e81SDag-Erling Smørgrav 	PROC_LOCK(p);
4009ca45e81SDag-Erling Smørgrav 	KASSERT((p->p_flag & P_INEXEC) == 0,
40191f91617SDavid E. O'Brien 	    ("%s(): process already has P_INEXEC flag", __func__));
4029ca45e81SDag-Erling Smørgrav 	p->p_flag |= P_INEXEC;
4039ca45e81SDag-Erling Smørgrav 	PROC_UNLOCK(p);
4049ca45e81SDag-Erling Smørgrav 
405df8bae1dSRodney W. Grimes 	/*
406c52007c2SDavid Greenman 	 * Initialize part of the common data
407df8bae1dSRodney W. Grimes 	 */
4088e572983SMateusz Guzik 	bzero(imgp, sizeof(*imgp));
409c52007c2SDavid Greenman 	imgp->proc = p;
410c52007c2SDavid Greenman 	imgp->attr = &attr;
411610ecfe0SMaxim Sobolev 	imgp->args = args;
412881010f0SBryan Drewery 	oldcred = p->p_ucred;
41301a2b567SKonstantin Belousov 	orig_osrel = p->p_osrel;
41401a2b567SKonstantin Belousov 	orig_fctl0 = p->p_fctl0;
41526f9a767SRodney W. Grimes 
416670cb89bSRobert Watson #ifdef MAC
417eca8a663SRobert Watson 	error = mac_execve_enter(imgp, mac_p);
418532c491bSJeff Roberson 	if (error)
419670cb89bSRobert Watson 		goto exec_fail;
420670cb89bSRobert Watson #endif
421670cb89bSRobert Watson 
42226f9a767SRodney W. Grimes 	/*
42326f9a767SRodney W. Grimes 	 * Translate the file name. namei() returns a vnode pointer
424e3043798SPedro F. Giffuni 	 *	in ni_vp among other things.
425ae1078d6SWayne Salamon 	 *
426ae1078d6SWayne Salamon 	 * XXXAUDIT: It would be desirable to also audit the name of the
427ae1078d6SWayne Salamon 	 * interpreter if this is an interpreted binary.
42826f9a767SRodney W. Grimes 	 */
429632dbc19SKonstantin Belousov 	if (args->fname != NULL) {
43078022527SKonstantin Belousov 		NDINIT(&nd, LOOKUP, ISOPEN | LOCKLEAF | LOCKSHARED | FOLLOW |
43178022527SKonstantin Belousov 		    SAVENAME | AUDITVNODE1, UIO_SYSSPACE, args->fname, td);
432632dbc19SKonstantin Belousov 	}
43326f9a767SRodney W. Grimes 
43436160958SMark Johnston 	SDT_PROBE1(proc, , , exec, args->fname);
435e506f34bSCraig Rodrigues 
43626f9a767SRodney W. Grimes interpret:
437632dbc19SKonstantin Belousov 	if (args->fname != NULL) {
43812bc222eSJonathan Anderson #ifdef CAPABILITY_MODE
43912bc222eSJonathan Anderson 		/*
44012bc222eSJonathan Anderson 		 * While capability mode can't reach this point via direct
44112bc222eSJonathan Anderson 		 * path arguments to execve(), we also don't allow
44212bc222eSJonathan Anderson 		 * interpreters to be used in capability mode (for now).
44312bc222eSJonathan Anderson 		 * Catch indirect lookups and return a permissions error.
44412bc222eSJonathan Anderson 		 */
44512bc222eSJonathan Anderson 		if (IN_CAPABILITY_MODE(td)) {
44612bc222eSJonathan Anderson 			error = ECAPMODE;
44712bc222eSJonathan Anderson 			goto exec_fail;
44812bc222eSJonathan Anderson 		}
44912bc222eSJonathan Anderson #endif
45069c9eff8SEd Schouten 		error = namei(&nd);
451610ecfe0SMaxim Sobolev 		if (error)
45226f9a767SRodney W. Grimes 			goto exec_fail;
45326f9a767SRodney W. Grimes 
45461617058SMateusz Guzik 		newtextvp = nd.ni_vp;
45561617058SMateusz Guzik 		imgp->vp = newtextvp;
456632dbc19SKonstantin Belousov 	} else {
45714961ba7SRobert Watson 		AUDIT_ARG_FD(args->fd);
458a9d2f8d8SRobert Watson 		/*
459c8e781f6SPawel Jakub Dawidek 		 * Descriptors opened only with O_EXEC or O_RDONLY are allowed.
460a9d2f8d8SRobert Watson 		 */
461cbd92ce6SMatt Macy 		error = fgetvp_exec(td, args->fd, &cap_fexecve_rights, &newtextvp);
462632dbc19SKonstantin Belousov 		if (error)
463632dbc19SKonstantin Belousov 			goto exec_fail;
46478022527SKonstantin Belousov 		vn_lock(newtextvp, LK_SHARED | LK_RETRY);
46561617058SMateusz Guzik 		AUDIT_ARG_VNODE1(newtextvp);
46661617058SMateusz Guzik 		imgp->vp = newtextvp;
467632dbc19SKonstantin Belousov 	}
46826f9a767SRodney W. Grimes 
46926f9a767SRodney W. Grimes 	/*
47078022527SKonstantin Belousov 	 * Check file permissions.  Also 'opens' file and sets its vnode to
47178022527SKonstantin Belousov 	 * text mode.
4729022e4adSDavid Greenman 	 */
473c52007c2SDavid Greenman 	error = exec_check_permissions(imgp);
474619eb6e5SJeff Roberson 	if (error)
47526f9a767SRodney W. Grimes 		goto exec_fail_dealloc;
476619eb6e5SJeff Roberson 
4778516dd18SPoul-Henning Kamp 	imgp->object = imgp->vp->v_object;
4788516dd18SPoul-Henning Kamp 	if (imgp->object != NULL)
4790b2ed1aeSJeff Roberson 		vm_object_reference(imgp->object);
48026f9a767SRodney W. Grimes 
4811616db3cSJohn Dyson 	error = exec_map_first_page(imgp);
4826d5a0a8cSDavid Greenman 	if (error)
48326f9a767SRodney W. Grimes 		goto exec_fail_dealloc;
48426f9a767SRodney W. Grimes 
485f231de47SKonstantin Belousov 	imgp->proc->p_osrel = 0;
486f5cf7589SKonstantin Belousov 	imgp->proc->p_fctl0 = 0;
487881010f0SBryan Drewery 
488881010f0SBryan Drewery 	/*
489881010f0SBryan Drewery 	 * Implement image setuid/setgid.
490881010f0SBryan Drewery 	 *
491881010f0SBryan Drewery 	 * Determine new credentials before attempting image activators
492881010f0SBryan Drewery 	 * so that it can be used by process_exec handlers to determine
493881010f0SBryan Drewery 	 * credential/setid changes.
494881010f0SBryan Drewery 	 *
495881010f0SBryan Drewery 	 * Don't honor setuid/setgid if the filesystem prohibits it or if
496881010f0SBryan Drewery 	 * the process is being traced.
497881010f0SBryan Drewery 	 *
498881010f0SBryan Drewery 	 * We disable setuid/setgid/etc in capability mode on the basis
499881010f0SBryan Drewery 	 * that most setugid applications are not written with that
500881010f0SBryan Drewery 	 * environment in mind, and will therefore almost certainly operate
501881010f0SBryan Drewery 	 * incorrectly. In principle there's no reason that setugid
502881010f0SBryan Drewery 	 * applications might not be useful in capability mode, so we may want
503881010f0SBryan Drewery 	 * to reconsider this conservative design choice in the future.
504881010f0SBryan Drewery 	 *
505881010f0SBryan Drewery 	 * XXXMAC: For the time being, use NOSUID to also prohibit
506881010f0SBryan Drewery 	 * transitions on the file system.
507881010f0SBryan Drewery 	 */
508881010f0SBryan Drewery 	credential_changing = 0;
509881010f0SBryan Drewery 	credential_changing |= (attr.va_mode & S_ISUID) &&
510881010f0SBryan Drewery 	    oldcred->cr_uid != attr.va_uid;
511881010f0SBryan Drewery 	credential_changing |= (attr.va_mode & S_ISGID) &&
512881010f0SBryan Drewery 	    oldcred->cr_gid != attr.va_gid;
513881010f0SBryan Drewery #ifdef MAC
514881010f0SBryan Drewery 	will_transition = mac_vnode_execve_will_transition(oldcred, imgp->vp,
515881010f0SBryan Drewery 	    interpvplabel, imgp);
516881010f0SBryan Drewery 	credential_changing |= will_transition;
517881010f0SBryan Drewery #endif
518881010f0SBryan Drewery 
5191302eea7SKonstantin Belousov 	/* Don't inherit PROC_PDEATHSIG_CTL value if setuid/setgid. */
520b9408863SKonstantin Belousov 	if (credential_changing)
521b9408863SKonstantin Belousov 		imgp->proc->p_pdeathsig = 0;
522b9408863SKonstantin Belousov 
523881010f0SBryan Drewery 	if (credential_changing &&
524881010f0SBryan Drewery #ifdef CAPABILITY_MODE
525881010f0SBryan Drewery 	    ((oldcred->cr_flags & CRED_FLAG_CAPMODE) == 0) &&
526881010f0SBryan Drewery #endif
527881010f0SBryan Drewery 	    (imgp->vp->v_mount->mnt_flag & MNT_NOSUID) == 0 &&
528881010f0SBryan Drewery 	    (p->p_flag & P_TRACED) == 0) {
529881010f0SBryan Drewery 		imgp->credential_setid = true;
530b249ce48SMateusz Guzik 		VOP_UNLOCK(imgp->vp);
531881010f0SBryan Drewery 		imgp->newcred = crdup(oldcred);
532881010f0SBryan Drewery 		if (attr.va_mode & S_ISUID) {
533881010f0SBryan Drewery 			euip = uifind(attr.va_uid);
534881010f0SBryan Drewery 			change_euid(imgp->newcred, euip);
535881010f0SBryan Drewery 		}
5361040254bSKonstantin Belousov 		vn_lock(imgp->vp, LK_SHARED | LK_RETRY);
537881010f0SBryan Drewery 		if (attr.va_mode & S_ISGID)
538881010f0SBryan Drewery 			change_egid(imgp->newcred, attr.va_gid);
539881010f0SBryan Drewery 		/*
540881010f0SBryan Drewery 		 * Implement correct POSIX saved-id behavior.
541881010f0SBryan Drewery 		 *
542881010f0SBryan Drewery 		 * XXXMAC: Note that the current logic will save the
543881010f0SBryan Drewery 		 * uid and gid if a MAC domain transition occurs, even
544881010f0SBryan Drewery 		 * though maybe it shouldn't.
545881010f0SBryan Drewery 		 */
546881010f0SBryan Drewery 		change_svuid(imgp->newcred, imgp->newcred->cr_uid);
547881010f0SBryan Drewery 		change_svgid(imgp->newcred, imgp->newcred->cr_gid);
548881010f0SBryan Drewery 	} else {
549881010f0SBryan Drewery 		/*
550881010f0SBryan Drewery 		 * Implement correct POSIX saved-id behavior.
551881010f0SBryan Drewery 		 *
552881010f0SBryan Drewery 		 * XXX: It's not clear that the existing behavior is
553881010f0SBryan Drewery 		 * POSIX-compliant.  A number of sources indicate that the
554881010f0SBryan Drewery 		 * saved uid/gid should only be updated if the new ruid is
555881010f0SBryan Drewery 		 * not equal to the old ruid, or the new euid is not equal
556881010f0SBryan Drewery 		 * to the old euid and the new euid is not equal to the old
557881010f0SBryan Drewery 		 * ruid.  The FreeBSD code always updates the saved uid/gid.
558881010f0SBryan Drewery 		 * Also, this code uses the new (replaced) euid and egid as
559881010f0SBryan Drewery 		 * the source, which may or may not be the right ones to use.
560881010f0SBryan Drewery 		 */
561881010f0SBryan Drewery 		if (oldcred->cr_svuid != oldcred->cr_uid ||
562881010f0SBryan Drewery 		    oldcred->cr_svgid != oldcred->cr_gid) {
563b249ce48SMateusz Guzik 			VOP_UNLOCK(imgp->vp);
564881010f0SBryan Drewery 			imgp->newcred = crdup(oldcred);
5651040254bSKonstantin Belousov 			vn_lock(imgp->vp, LK_SHARED | LK_RETRY);
566881010f0SBryan Drewery 			change_svuid(imgp->newcred, imgp->newcred->cr_uid);
567881010f0SBryan Drewery 			change_svgid(imgp->newcred, imgp->newcred->cr_gid);
568881010f0SBryan Drewery 		}
569881010f0SBryan Drewery 	}
570881010f0SBryan Drewery 	/* The new credentials are installed into the process later. */
571881010f0SBryan Drewery 
57226f9a767SRodney W. Grimes 	/*
5731afd78b3SBryan Drewery 	 * Do the best to calculate the full path to the image file.
5741afd78b3SBryan Drewery 	 */
5751afd78b3SBryan Drewery 	if (args->fname != NULL && args->fname[0] == '/')
5761afd78b3SBryan Drewery 		imgp->execpath = args->fname;
5771afd78b3SBryan Drewery 	else {
578b249ce48SMateusz Guzik 		VOP_UNLOCK(imgp->vp);
5791afd78b3SBryan Drewery 		if (vn_fullpath(td, imgp->vp, &imgp->execpath,
5801afd78b3SBryan Drewery 		    &imgp->freepath) != 0)
5811afd78b3SBryan Drewery 			imgp->execpath = args->fname;
5821040254bSKonstantin Belousov 		vn_lock(imgp->vp, LK_SHARED | LK_RETRY);
5831afd78b3SBryan Drewery 	}
5841afd78b3SBryan Drewery 
5851afd78b3SBryan Drewery 	/*
586d323ddf3SMatthew Dillon 	 *	If the current process has a special image activator it
587d323ddf3SMatthew Dillon 	 *	wants to try first, call it.   For example, emulating shell
588d323ddf3SMatthew Dillon 	 *	scripts differently.
58926f9a767SRodney W. Grimes 	 */
590d323ddf3SMatthew Dillon 	error = -1;
591d323ddf3SMatthew Dillon 	if ((img_first = imgp->proc->p_sysent->sv_imgact_try) != NULL)
592d323ddf3SMatthew Dillon 		error = img_first(imgp);
593d323ddf3SMatthew Dillon 
594d323ddf3SMatthew Dillon 	/*
595d323ddf3SMatthew Dillon 	 *	Loop through the list of image activators, calling each one.
596d323ddf3SMatthew Dillon 	 *	An activator returns -1 if there is no match, 0 on success,
597d323ddf3SMatthew Dillon 	 *	and an error otherwise.
598d323ddf3SMatthew Dillon 	 */
599d323ddf3SMatthew Dillon 	for (i = 0; error == -1 && execsw[i]; ++i) {
600d323ddf3SMatthew Dillon 		if (execsw[i]->ex_imgact == NULL ||
601d323ddf3SMatthew Dillon 		    execsw[i]->ex_imgact == img_first) {
602d323ddf3SMatthew Dillon 			continue;
603d323ddf3SMatthew Dillon 		}
604c52007c2SDavid Greenman 		error = (*execsw[i]->ex_imgact)(imgp);
605d323ddf3SMatthew Dillon 	}
606d323ddf3SMatthew Dillon 
607d323ddf3SMatthew Dillon 	if (error) {
60878022527SKonstantin Belousov 		if (error == -1)
609d323ddf3SMatthew Dillon 			error = ENOEXEC;
61026f9a767SRodney W. Grimes 		goto exec_fail_dealloc;
611d323ddf3SMatthew Dillon 	}
612d323ddf3SMatthew Dillon 
613d323ddf3SMatthew Dillon 	/*
614d323ddf3SMatthew Dillon 	 * Special interpreter operation, cleanup and loop up to try to
615d323ddf3SMatthew Dillon 	 * activate the interpreter.
616d323ddf3SMatthew Dillon 	 */
617c52007c2SDavid Greenman 	if (imgp->interpreted) {
6181616db3cSJohn Dyson 		exec_unmap_first_page(imgp);
619619eb6e5SJeff Roberson 		/*
62078022527SKonstantin Belousov 		 * The text reference needs to be removed for scripts.
62178022527SKonstantin Belousov 		 * There is a short period before we determine that
62278022527SKonstantin Belousov 		 * something is a script where text reference is active.
62378022527SKonstantin Belousov 		 * The vnode lock is held over this entire period
62478022527SKonstantin Belousov 		 * so nothing should illegitimately be blocked.
625619eb6e5SJeff Roberson 		 */
6261c36b728SKonstantin Belousov 		MPASS(imgp->textset);
6271c36b728SKonstantin Belousov 		VOP_UNSET_TEXT_CHECKED(newtextvp);
6281c36b728SKonstantin Belousov 		imgp->textset = false;
629762e6b85SEivind Eklund 		/* free name buffer and old vnode */
630632dbc19SKonstantin Belousov 		if (args->fname != NULL)
63169c9eff8SEd Schouten 			NDFREE(&nd, NDF_ONLY_PNBUF);
632670cb89bSRobert Watson #ifdef MAC
63361617058SMateusz Guzik 		mac_execve_interpreter_enter(newtextvp, &interpvplabel);
634670cb89bSRobert Watson #endif
6359a75ea23SKonstantin Belousov 		if (imgp->opened) {
63661617058SMateusz Guzik 			VOP_CLOSE(newtextvp, FREAD, td->td_ucred, td);
6379a75ea23SKonstantin Belousov 			imgp->opened = 0;
6389a75ea23SKonstantin Belousov 		}
63961617058SMateusz Guzik 		vput(newtextvp);
6400b2ed1aeSJeff Roberson 		vm_object_deallocate(imgp->object);
6410b2ed1aeSJeff Roberson 		imgp->object = NULL;
642881010f0SBryan Drewery 		imgp->credential_setid = false;
643881010f0SBryan Drewery 		if (imgp->newcred != NULL) {
644881010f0SBryan Drewery 			crfree(imgp->newcred);
645881010f0SBryan Drewery 			imgp->newcred = NULL;
646881010f0SBryan Drewery 		}
6471afd78b3SBryan Drewery 		imgp->execpath = NULL;
6481afd78b3SBryan Drewery 		free(imgp->freepath, M_TEMP);
6491afd78b3SBryan Drewery 		imgp->freepath = NULL;
65026f9a767SRodney W. Grimes 		/* set new name to that of the interpreter */
651f422bc30SJohn Baldwin 		NDINIT(&nd, LOOKUP, ISOPEN | LOCKLEAF | FOLLOW | SAVENAME,
652b40ce416SJulian Elischer 		    UIO_SYSSPACE, imgp->interpreter_name, td);
653632dbc19SKonstantin Belousov 		args->fname = imgp->interpreter_name;
65426f9a767SRodney W. Grimes 		goto interpret;
65526f9a767SRodney W. Grimes 	}
65626f9a767SRodney W. Grimes 
65726f9a767SRodney W. Grimes 	/*
658ded7d39cSChristian S.J. Peron 	 * NB: We unlock the vnode here because it is believed that none
659ded7d39cSChristian S.J. Peron 	 * of the sv_copyout_strings/sv_fixup operations require the vnode.
660ded7d39cSChristian S.J. Peron 	 */
661b249ce48SMateusz Guzik 	VOP_UNLOCK(imgp->vp);
6623ff06357SKonstantin Belousov 
663eda6009cSKonstantin Belousov 	if (disallow_high_osrel &&
664eda6009cSKonstantin Belousov 	    P_OSREL_MAJOR(p->p_osrel) > P_OSREL_MAJOR(__FreeBSD_version)) {
665eda6009cSKonstantin Belousov 		error = ENOEXEC;
666eda6009cSKonstantin Belousov 		uprintf("Osrel %d for image %s too high\n", p->p_osrel,
667eda6009cSKonstantin Belousov 		    imgp->execpath != NULL ? imgp->execpath : "<unresolved>");
668eda6009cSKonstantin Belousov 		vn_lock(imgp->vp, LK_SHARED | LK_RETRY);
669eda6009cSKonstantin Belousov 		goto exec_fail_dealloc;
670eda6009cSKonstantin Belousov 	}
671eda6009cSKonstantin Belousov 
67239f5ebb7SEd Schouten 	/* ABI enforces the use of Capsicum. Switch into capabilities mode. */
67339f5ebb7SEd Schouten 	if (SV_PROC_FLAG(p, SV_CAPSICUM))
67439f5ebb7SEd Schouten 		sys_cap_enter(td, NULL);
67539f5ebb7SEd Schouten 
676ded7d39cSChristian S.J. Peron 	/*
67791ff2d48SEdward Tomasz Napierala 	 * Copy out strings (args and env) and initialize stack base.
67826f9a767SRodney W. Grimes 	 */
67903b0d68cSJohn Baldwin 	error = (*p->p_sysent->sv_copyout_strings)(imgp, &stack_base);
68003b0d68cSJohn Baldwin 	if (error != 0) {
68103b0d68cSJohn Baldwin 		vn_lock(imgp->vp, LK_SHARED | LK_RETRY);
68203b0d68cSJohn Baldwin 		goto exec_fail_dealloc;
68303b0d68cSJohn Baldwin 	}
68426f9a767SRodney W. Grimes 
68526f9a767SRodney W. Grimes 	/*
68691ff2d48SEdward Tomasz Napierala 	 * Stack setup.
68726f9a767SRodney W. Grimes 	 */
6885f77b8a8SBrooks Davis 	error = (*p->p_sysent->sv_fixup)(&stack_base, imgp);
6896f26dd50SKonstantin Belousov 	if (error != 0) {
6906f26dd50SKonstantin Belousov 		vn_lock(imgp->vp, LK_SHARED | LK_RETRY);
6915f77b8a8SBrooks Davis 		goto exec_fail_dealloc;
6926f26dd50SKonstantin Belousov 	}
69326f9a767SRodney W. Grimes 
694457f7e23SEd Schouten 	if (args->fdp != NULL) {
695457f7e23SEd Schouten 		/* Install a brand new file descriptor table. */
696457f7e23SEd Schouten 		fdinstall_remapped(td, args->fdp);
697457f7e23SEd Schouten 		args->fdp = NULL;
698457f7e23SEd Schouten 	} else {
699a78e8d2aSDavid Greenman 		/*
700457f7e23SEd Schouten 		 * Keep on using the existing file descriptor table. For
701457f7e23SEd Schouten 		 * security and other reasons, the file descriptor table
702457f7e23SEd Schouten 		 * cannot be shared after an exec.
703a78e8d2aSDavid Greenman 		 */
704b9d32c36SMateusz Guzik 		fdunshare(td);
705b0bc0cadSMateusz Guzik 		/* close files on exec */
706b0bc0cadSMateusz Guzik 		fdcloseexec(td);
707457f7e23SEd Schouten 	}
708a78e8d2aSDavid Greenman 
709333ea485SGuido van Rooij 	/*
7109b3b1c5fSJohn Baldwin 	 * Malloc things before we need locks.
7119b3b1c5fSJohn Baldwin 	 */
712f373437aSBrooks Davis 	i = exec_args_get_begin_envv(imgp->args) - imgp->args->begin_argv;
7135997cae9SDon Lewis 	/* Cache arguments if they fit inside our allowance */
7145997cae9SDon Lewis 	if (ps_arg_cache_limit >= i + sizeof(struct pargs)) {
7159b3b1c5fSJohn Baldwin 		newargs = pargs_alloc(i);
7165997cae9SDon Lewis 		bcopy(imgp->args->begin_argv, newargs->ar_args, i);
7175997cae9SDon Lewis 	}
7189b3b1c5fSJohn Baldwin 
7199b3b1c5fSJohn Baldwin 	/*
720333ea485SGuido van Rooij 	 * For security and other reasons, signal handlers cannot
7218688bb93SJohn Baldwin 	 * be shared after an exec. The new process gets a copy of the old
722b2c3fa70SDima Dorfman 	 * handlers. In execsigs(), the new process will have its signals
723333ea485SGuido van Rooij 	 * reset.
724333ea485SGuido van Rooij 	 */
72590af4afaSJohn Baldwin 	if (sigacts_shared(p->p_sigacts)) {
72690af4afaSJohn Baldwin 		oldsigacts = p->p_sigacts;
72790af4afaSJohn Baldwin 		newsigacts = sigacts_alloc();
72890af4afaSJohn Baldwin 		sigacts_copy(newsigacts, oldsigacts);
729a6bad85eSMateusz Guzik 	}
730333ea485SGuido van Rooij 
731cda68844SMateusz Guzik 	vn_lock(imgp->vp, LK_SHARED | LK_RETRY);
732cda68844SMateusz Guzik 
733d00c8ea4SMateusz Guzik 	PROC_LOCK(p);
734d00c8ea4SMateusz Guzik 	if (oldsigacts)
735d00c8ea4SMateusz Guzik 		p->p_sigacts = newsigacts;
736fdf4e8b3SWarner Losh 	/* Stop profiling */
737fdf4e8b3SWarner Losh 	stopprofclock(p);
738fdf4e8b3SWarner Losh 
73926f9a767SRodney W. Grimes 	/* reset caught signals */
74026f9a767SRodney W. Grimes 	execsigs(p);
74126f9a767SRodney W. Grimes 
74226f9a767SRodney W. Grimes 	/* name this process - nameiexec(p, ndp) */
7435ca4819dSJohn Baldwin 	bzero(p->p_comm, sizeof(p->p_comm));
7445ca4819dSJohn Baldwin 	if (args->fname)
7455ca4819dSJohn Baldwin 		bcopy(nd.ni_cnd.cn_nameptr, p->p_comm,
7465ca4819dSJohn Baldwin 		    min(nd.ni_cnd.cn_namelen, MAXCOMLEN));
74761617058SMateusz Guzik 	else if (vn_commname(newtextvp, p->p_comm, sizeof(p->p_comm)) != 0)
7485ca4819dSJohn Baldwin 		bcopy(fexecv_proc_title, p->p_comm, sizeof(fexecv_proc_title));
749ca081fdbSJulian Elischer 	bcopy(p->p_comm, td->td_name, sizeof(td->td_name));
75044ad5475SJohn Baldwin #ifdef KTR
75144ad5475SJohn Baldwin 	sched_clear_tdname(td);
75244ad5475SJohn Baldwin #endif
75326f9a767SRodney W. Grimes 
75426f9a767SRodney W. Grimes 	/*
75524b34f09SSujal Patel 	 * mark as execed, wakeup the process that vforked (if any) and tell
756dc733423SDag-Erling Smørgrav 	 * it that it now has its own resources back
75726f9a767SRodney W. Grimes 	 */
75826f9a767SRodney W. Grimes 	p->p_flag |= P_EXEC;
759677258f7SKonstantin Belousov 	if ((p->p_flag2 & P2_NOTRACE_EXEC) == 0)
760677258f7SKonstantin Belousov 		p->p_flag2 &= ~P2_NOTRACE;
761fe69291fSKonstantin Belousov 	if ((p->p_flag2 & P2_STKGAP_DISABLE_EXEC) == 0)
762fe69291fSKonstantin Belousov 		p->p_flag2 &= ~P2_STKGAP_DISABLE;
763965d0860SMateusz Guzik 	if (p->p_flag & P_PPWAIT) {
764888d4d4fSKonstantin Belousov 		p->p_flag &= ~(P_PPWAIT | P_PPTRACE);
765aeb32571SKonstantin Belousov 		cv_broadcast(&p->p_pwait);
76677d68094SKonstantin Belousov 		/* STOPs are no longer ignored, arrange for AST */
76777d68094SKonstantin Belousov 		signotify(td);
76826f9a767SRodney W. Grimes 	}
76926f9a767SRodney W. Grimes 
77026f9a767SRodney W. Grimes 	/*
771881010f0SBryan Drewery 	 * Implement image setuid/setgid installation.
772c52007c2SDavid Greenman 	 */
773881010f0SBryan Drewery 	if (imgp->credential_setid) {
774c52007c2SDavid Greenman 		/*
775c52007c2SDavid Greenman 		 * Turn off syscall tracing for set-id programs, except for
776b85db196SPeter Wemm 		 * root.  Record any set-id flags first to make sure that
777b85db196SPeter Wemm 		 * we do not regain any tracing during a possible block.
77826f9a767SRodney W. Grimes 		 */
779b85db196SPeter Wemm 		setsugid(p);
780acd3428bSRobert Watson 
7816c84de02SJohn Baldwin #ifdef KTRACE
782c331c970SAndriy Gapon 		if (p->p_tracecred != NULL &&
783cc426dd3SMateusz Guzik 		    priv_check_cred(p->p_tracecred, PRIV_DEBUG_DIFFCRED))
784d680caabSJohn Baldwin 			ktrprocexec(p, &tracecred, &tracevp);
7856c84de02SJohn Baldwin #endif
78628b325aaSDon Lewis 		/*
787c1e2d386SNate Lawson 		 * Close any file descriptors 0..2 that reference procfs,
788c1e2d386SNate Lawson 		 * then make sure file descriptors 0..2 are in use.
78928b325aaSDon Lewis 		 *
7908a5177ccSMateusz Guzik 		 * Both fdsetugidsafety() and fdcheckstd() may call functions
7918a5177ccSMateusz Guzik 		 * taking sleepable locks, so temporarily drop our locks.
79228b325aaSDon Lewis 		 */
79328b325aaSDon Lewis 		PROC_UNLOCK(p);
794b249ce48SMateusz Guzik 		VOP_UNLOCK(imgp->vp);
79511888da8SMateusz Guzik 		fdsetugidsafety(td);
796e983a376SJacques Vidrine 		error = fdcheckstd(td);
7975e2554b7SMateusz Guzik 		vn_lock(imgp->vp, LK_SHARED | LK_RETRY);
798cda68844SMateusz Guzik 		if (error != 0)
799cda68844SMateusz Guzik 			goto exec_fail_dealloc;
800e1b1aa3bSJohn Baldwin 		PROC_LOCK(p);
801ccafe7ebSRobert Watson #ifdef MAC
802670cb89bSRobert Watson 		if (will_transition) {
803881010f0SBryan Drewery 			mac_vnode_execve_transition(oldcred, imgp->newcred,
804881010f0SBryan Drewery 			    imgp->vp, interpvplabel, imgp);
805670cb89bSRobert Watson 		}
806ccafe7ebSRobert Watson #endif
807c52007c2SDavid Greenman 	} else {
808b1fc0ec1SRobert Watson 		if (oldcred->cr_uid == oldcred->cr_ruid &&
809b1fc0ec1SRobert Watson 		    oldcred->cr_gid == oldcred->cr_rgid)
810c52007c2SDavid Greenman 			p->p_flag &= ~P_SUGID;
811881010f0SBryan Drewery 	}
81226f9a767SRodney W. Grimes 	/*
813881010f0SBryan Drewery 	 * Set the new credentials.
81426f9a767SRodney W. Grimes 	 */
8153fc292d5SKonstantin Belousov 	if (imgp->newcred != NULL) {
816881010f0SBryan Drewery 		proc_set_cred(p, imgp->newcred);
8173fc292d5SKonstantin Belousov 		crfree(oldcred);
8183fc292d5SKonstantin Belousov 		oldcred = NULL;
8193fc292d5SKonstantin Belousov 	}
82026f9a767SRodney W. Grimes 
82126f9a767SRodney W. Grimes 	/*
822853be5ffSMateusz Guzik 	 * Store the vp for use in procfs.  This vnode was referenced by namei
823853be5ffSMateusz Guzik 	 * or fgetvp_exec.
8242a531c80SDavid Greenman 	 */
82561617058SMateusz Guzik 	oldtextvp = p->p_textvp;
82661617058SMateusz Guzik 	p->p_textvp = newtextvp;
8272a531c80SDavid Greenman 
8285d217f17SJohn Birrell #ifdef KDTRACE_HOOKS
8295d217f17SJohn Birrell 	/*
8305d217f17SJohn Birrell 	 * Tell the DTrace fasttrap provider about the exec if it
8315d217f17SJohn Birrell 	 * has declared an interest.
8325d217f17SJohn Birrell 	 */
8335d217f17SJohn Birrell 	if (dtrace_fasttrap_exec)
8345d217f17SJohn Birrell 		dtrace_fasttrap_exec(p);
8355d217f17SJohn Birrell #endif
8365d217f17SJohn Birrell 
8372a531c80SDavid Greenman 	/*
8389ca45e81SDag-Erling Smørgrav 	 * Notify others that we exec'd, and clear the P_INEXEC flag
8399ca45e81SDag-Erling Smørgrav 	 * as we're now a bona fide freshly-execed process.
840cb679c38SJonathan Lemon 	 */
8419e590ff0SKonstantin Belousov 	KNOTE_LOCKED(p->p_klist, NOTE_EXEC);
8429ca45e81SDag-Erling Smørgrav 	p->p_flag &= ~P_INEXEC;
843cb679c38SJonathan Lemon 
84426f9a767SRodney W. Grimes 	/* clear "fork but no exec" flag, as we _are_ execing */
84526f9a767SRodney W. Grimes 	p->p_acflag &= ~AFORK;
84626f9a767SRodney W. Grimes 
8475997cae9SDon Lewis 	/*
84834ea500bSDon Lewis 	 * Free any previous argument cache and replace it with
8495997cae9SDon Lewis 	 * the new argument cache, if any.
8505997cae9SDon Lewis 	 */
8519b3b1c5fSJohn Baldwin 	oldargs = p->p_args;
852e1b1aa3bSJohn Baldwin 	p->p_args = newargs;
853e1b1aa3bSJohn Baldwin 	newargs = NULL;
854ebccf1e3SJoseph Koshy 
85580a2397aSMateusz Guzik 	PROC_UNLOCK(p);
85680a2397aSMateusz Guzik 
857ebccf1e3SJoseph Koshy #ifdef	HWPMC_HOOKS
858ebccf1e3SJoseph Koshy 	/*
859f263522aSJoseph Koshy 	 * Check if system-wide sampling is in effect or if the
860f263522aSJoseph Koshy 	 * current process is using PMCs.  If so, do exec() time
861ebccf1e3SJoseph Koshy 	 * processing.  This processing needs to happen AFTER the
862ebccf1e3SJoseph Koshy 	 * P_INEXEC flag is cleared.
863ebccf1e3SJoseph Koshy 	 */
864f263522aSJoseph Koshy 	if (PMC_SYSTEM_SAMPLING_ACTIVE() || PMC_PROC_IS_USING_PMCS(p)) {
865b249ce48SMateusz Guzik 		VOP_UNLOCK(imgp->vp);
86615139246SJoseph Koshy 		pe.pm_credentialschanged = credential_changing;
86715139246SJoseph Koshy 		pe.pm_entryaddr = imgp->entry_addr;
86815139246SJoseph Koshy 
86915139246SJoseph Koshy 		PMC_CALL_HOOK_X(td, PMC_FN_PROCESS_EXEC, (void *) &pe);
8702974cc36SKonstantin Belousov 		vn_lock(imgp->vp, LK_SHARED | LK_RETRY);
87180a2397aSMateusz Guzik 	}
872ebccf1e3SJoseph Koshy #endif
873e1b1aa3bSJohn Baldwin 
874e913ca22SDoug Rabson 	/* Set values passed into the program in registers. */
87531174518SJohn Baldwin 	(*p->p_sysent->sv_setregs)(td, imgp, stack_base);
876e913ca22SDoug Rabson 
877643656cfSMateusz Guzik 	VOP_MMAPPED(imgp->vp);
8786341095eSKen Smith 
87936160958SMark Johnston 	SDT_PROBE1(proc, , , exec__success, args->fname);
8805d217f17SJohn Birrell 
8811616db3cSJohn Dyson exec_fail_dealloc:
88201a2b567SKonstantin Belousov 	if (error != 0) {
88301a2b567SKonstantin Belousov 		p->p_osrel = orig_osrel;
88401a2b567SKonstantin Belousov 		p->p_fctl0 = orig_fctl0;
88501a2b567SKonstantin Belousov 	}
88601a2b567SKonstantin Belousov 
887d6c847f3SBruce Evans 	if (imgp->firstpage != NULL)
8881616db3cSJohn Dyson 		exec_unmap_first_page(imgp);
88926f9a767SRodney W. Grimes 
890d6c847f3SBruce Evans 	if (imgp->vp != NULL) {
891632dbc19SKonstantin Belousov 		if (args->fname)
89269c9eff8SEd Schouten 			NDFREE(&nd, NDF_ONLY_PNBUF);
8939a75ea23SKonstantin Belousov 		if (imgp->opened)
8949a75ea23SKonstantin Belousov 			VOP_CLOSE(imgp->vp, FREAD, td->td_ucred, td);
89578022527SKonstantin Belousov 		if (imgp->textset)
89678022527SKonstantin Belousov 			VOP_UNSET_TEXT_CHECKED(imgp->vp);
897853be5ffSMateusz Guzik 		if (error != 0)
898619eb6e5SJeff Roberson 			vput(imgp->vp);
899853be5ffSMateusz Guzik 		else
900b249ce48SMateusz Guzik 			VOP_UNLOCK(imgp->vp);
901a3cf6ebaSDavid Greenman 	}
90226f9a767SRodney W. Grimes 
903d6c847f3SBruce Evans 	if (imgp->object != NULL)
9040b2ed1aeSJeff Roberson 		vm_object_deallocate(imgp->object);
9050b2ed1aeSJeff Roberson 
9063ff06357SKonstantin Belousov 	free(imgp->freepath, M_TEMP);
9073ff06357SKonstantin Belousov 
908d1989db5SRobert Drehmel 	if (error == 0) {
909e6b645aeSMateusz Guzik 		if (p->p_ptevents & PTRACE_EXEC) {
910afe1a688SKonstantin Belousov 			PROC_LOCK(p);
9118d570f64SJohn Baldwin 			if (p->p_ptevents & PTRACE_EXEC)
912afe1a688SKonstantin Belousov 				td->td_dbgflags |= TDB_EXEC;
913afe1a688SKonstantin Belousov 			PROC_UNLOCK(p);
914e6b645aeSMateusz Guzik 		}
915afe1a688SKonstantin Belousov 
916d1989db5SRobert Drehmel 		/*
917d1989db5SRobert Drehmel 		 * Stop the process here if its stop event mask has
918d1989db5SRobert Drehmel 		 * the S_EXEC bit set.
919d1989db5SRobert Drehmel 		 */
920d1989db5SRobert Drehmel 		STOPEVENT(p, S_EXEC, 0);
921cda68844SMateusz Guzik 	} else {
92226f9a767SRodney W. Grimes exec_fail:
9239ca45e81SDag-Erling Smørgrav 		/* we're done here, clear P_INEXEC */
9249ca45e81SDag-Erling Smørgrav 		PROC_LOCK(p);
9259ca45e81SDag-Erling Smørgrav 		p->p_flag &= ~P_INEXEC;
9269ca45e81SDag-Erling Smørgrav 		PROC_UNLOCK(p);
9279ca45e81SDag-Erling Smørgrav 
92836160958SMark Johnston 		SDT_PROBE1(proc, , , exec__failure, error);
929cda68844SMateusz Guzik 	}
9305d217f17SJohn Birrell 
9313fc292d5SKonstantin Belousov 	if (imgp->newcred != NULL && oldcred != NULL)
9323fc292d5SKonstantin Belousov 		crfree(imgp->newcred);
9333fc292d5SKonstantin Belousov 
934670cb89bSRobert Watson #ifdef MAC
935670cb89bSRobert Watson 	mac_execve_exit(imgp);
9366356dba0SRobert Watson 	mac_execve_interpreter_exit(interpvplabel);
937670cb89bSRobert Watson #endif
9388917b8d2SJohn Baldwin 	exec_free_args(args);
9398917b8d2SJohn Baldwin 
940cda68844SMateusz Guzik 	/*
941cda68844SMateusz Guzik 	 * Handle deferred decrement of ref counts.
942cda68844SMateusz Guzik 	 */
943cda68844SMateusz Guzik 	if (oldtextvp != NULL)
944cda68844SMateusz Guzik 		vrele(oldtextvp);
945cda68844SMateusz Guzik #ifdef KTRACE
946cda68844SMateusz Guzik 	if (tracevp != NULL)
947cda68844SMateusz Guzik 		vrele(tracevp);
948cda68844SMateusz Guzik 	if (tracecred != NULL)
949cda68844SMateusz Guzik 		crfree(tracecred);
950cda68844SMateusz Guzik #endif
951cda68844SMateusz Guzik 	pargs_drop(oldargs);
952cda68844SMateusz Guzik 	pargs_drop(newargs);
953cda68844SMateusz Guzik 	if (oldsigacts != NULL)
954cda68844SMateusz Guzik 		sigacts_free(oldsigacts);
955cda68844SMateusz Guzik 	if (euip != NULL)
956cda68844SMateusz Guzik 		uifree(euip);
957cda68844SMateusz Guzik 
9588917b8d2SJohn Baldwin 	if (error && imgp->vmspace_destroyed) {
9598917b8d2SJohn Baldwin 		/* sorry, no more process anymore. exit gracefully */
960b4490c6eSKonstantin Belousov 		exit1(td, 0, SIGABRT);
9618917b8d2SJohn Baldwin 		/* NOT REACHED */
9628917b8d2SJohn Baldwin 	}
9637705d4b2SDmitry Chagin 
9647705d4b2SDmitry Chagin #ifdef KTRACE
9657705d4b2SDmitry Chagin 	if (error == 0)
9667705d4b2SDmitry Chagin 		ktrprocctor(p);
9677705d4b2SDmitry Chagin #endif
9687705d4b2SDmitry Chagin 
969814629ddSEd Schouten 	/*
970814629ddSEd Schouten 	 * We don't want cpu_set_syscall_retval() to overwrite any of
971814629ddSEd Schouten 	 * the register values put in place by exec_setregs().
972814629ddSEd Schouten 	 * Implementations of cpu_set_syscall_retval() will leave
973814629ddSEd Schouten 	 * registers unmodified when returning EJUSTRETURN.
974814629ddSEd Schouten 	 */
975814629ddSEd Schouten 	return (error == 0 ? EJUSTRETURN : error);
97626f9a767SRodney W. Grimes }
97726f9a767SRodney W. Grimes 
9781616db3cSJohn Dyson int
979b8d908b7SEd Maste exec_map_first_page(struct image_params *imgp)
9801616db3cSJohn Dyson {
9811616db3cSJohn Dyson 	vm_object_t object;
982af009714SJeff Roberson 	vm_page_t m;
983af009714SJeff Roberson 	int error;
9841616db3cSJohn Dyson 
985d6c847f3SBruce Evans 	if (imgp->firstpage != NULL)
9861616db3cSJohn Dyson 		exec_unmap_first_page(imgp);
9871616db3cSJohn Dyson 
9888516dd18SPoul-Henning Kamp 	object = imgp->vp->v_object;
9894d7d2993SJeff Roberson 	if (object == NULL)
9904d7d2993SJeff Roberson 		return (EACCES);
991f8a47341SAlan Cox #if VM_NRESERVLEVEL > 0
9927aaf252cSJeff Roberson 	if ((object->flags & OBJ_COLORED) == 0) {
9937aaf252cSJeff Roberson 		VM_OBJECT_WLOCK(object);
9943d653db0SAlan Cox 		vm_object_color(object, 0);
9957aaf252cSJeff Roberson 		VM_OBJECT_WUNLOCK(object);
9967aaf252cSJeff Roberson 	}
997f8a47341SAlan Cox #endif
9987aaf252cSJeff Roberson 	error = vm_page_grab_valid_unlocked(&m, object, 0,
999af009714SJeff Roberson 	    VM_ALLOC_COUNT(VM_INITIAL_PAGEIN) |
1000af009714SJeff Roberson             VM_ALLOC_NORMAL | VM_ALLOC_NOBUSY | VM_ALLOC_WIRED);
10011616db3cSJohn Dyson 
1002af009714SJeff Roberson 	if (error != VM_PAGER_OK)
1003af009714SJeff Roberson 		return (EIO);
1004af009714SJeff Roberson 	imgp->firstpage = sf_buf_alloc(m, 0);
100559c8bc40SAlan Cox 	imgp->image_header = (char *)sf_buf_kva(imgp->firstpage);
10061616db3cSJohn Dyson 
1007a7cddfedSJake Burkholder 	return (0);
10081616db3cSJohn Dyson }
10091616db3cSJohn Dyson 
10101616db3cSJohn Dyson void
10113e85b721SEd Maste exec_unmap_first_page(struct image_params *imgp)
10121616db3cSJohn Dyson {
101359c8bc40SAlan Cox 	vm_page_t m;
101423955314SAlfred Perlstein 
1015d6c847f3SBruce Evans 	if (imgp->firstpage != NULL) {
101659c8bc40SAlan Cox 		m = sf_buf_page(imgp->firstpage);
101759c8bc40SAlan Cox 		sf_buf_free(imgp->firstpage);
10181616db3cSJohn Dyson 		imgp->firstpage = NULL;
1019eeacb3b0SMark Johnston 		vm_page_unwire(m, PQ_ACTIVE);
10201616db3cSJohn Dyson 	}
10211616db3cSJohn Dyson }
10221616db3cSJohn Dyson 
102326f9a767SRodney W. Grimes /*
1024467b3975SKonstantin Belousov  * Destroy old address space, and allocate a new stack.
1025467b3975SKonstantin Belousov  *	The new stack is only sgrowsiz large because it is grown
1026467b3975SKonstantin Belousov  *	automatically on a page fault.
102726f9a767SRodney W. Grimes  */
102826f9a767SRodney W. Grimes int
10293e85b721SEd Maste exec_new_vmspace(struct image_params *imgp, struct sysentvec *sv)
103026f9a767SRodney W. Grimes {
103126f9a767SRodney W. Grimes 	int error;
10325e20c11fSAlan Cox 	struct proc *p = imgp->proc;
10335e20c11fSAlan Cox 	struct vmspace *vmspace = p->p_vmspace;
1034146fc63fSKonstantin Belousov 	struct thread *td = curthread;
10356297a3d8SKonstantin Belousov 	vm_object_t obj;
1036316b3843SKonstantin Belousov 	struct rlimit rlim_stack;
1037878adb85SBjoern A. Zeeb 	vm_offset_t sv_minuser, stack_addr;
103805ba50f5SJake Burkholder 	vm_map_t map;
103959d8f3ffSJohn Baldwin 	u_long ssiz;
104026f9a767SRodney W. Grimes 
1041c52007c2SDavid Greenman 	imgp->vmspace_destroyed = 1;
1042993182e5SAlexander Leidinger 	imgp->sysent = sv;
104326f9a767SRodney W. Grimes 
1044a113b17fSKonstantin Belousov 	sigfastblock_clear(td);
1045146fc63fSKonstantin Belousov 
1046bd37fd72SKris Kennaway 	/* May be called with Giant held */
10472ca45184SMatt Joras 	EVENTHANDLER_DIRECT_INVOKE(process_exec, p, imgp);
10486f5dafeaSAlan Cox 
10496f5dafeaSAlan Cox 	/*
1050af9ec885SJohn Dyson 	 * Blow away entire process VM, if address space not shared,
1051af9ec885SJohn Dyson 	 * otherwise, create a new VM space so that other threads are
1052af9ec885SJohn Dyson 	 * not disrupted
1053af9ec885SJohn Dyson 	 */
105405ba50f5SJake Burkholder 	map = &vmspace->vm_map;
1055878adb85SBjoern A. Zeeb 	if (map_at_zero)
1056878adb85SBjoern A. Zeeb 		sv_minuser = sv->sv_minuser;
1057878adb85SBjoern A. Zeeb 	else
1058878adb85SBjoern A. Zeeb 		sv_minuser = MAX(sv->sv_minuser, PAGE_SIZE);
1059878adb85SBjoern A. Zeeb 	if (vmspace->vm_refcnt == 1 && vm_map_min(map) == sv_minuser &&
10606f1fe330SKonstantin Belousov 	    vm_map_max(map) == sv->sv_maxuser &&
10616f1fe330SKonstantin Belousov 	    cpu_exec_vmspace_reuse(p, map)) {
10623db161e0SMatthew Dillon 		shmexit(vmspace);
1063b9eee07eSPeter Wemm 		pmap_remove_pages(vmspace_pmap(vmspace));
106405ba50f5SJake Burkholder 		vm_map_remove(map, vm_map_min(map), vm_map_max(map));
1065fa50a355SKonstantin Belousov 		/*
1066fa50a355SKonstantin Belousov 		 * An exec terminates mlockall(MCL_FUTURE), ASLR state
1067fa50a355SKonstantin Belousov 		 * must be re-evaluated.
1068fa50a355SKonstantin Belousov 		 */
10698056df6eSAlan Cox 		vm_map_lock(map);
1070fa50a355SKonstantin Belousov 		vm_map_modflags(map, 0, MAP_WIREFUTURE | MAP_ASLR |
1071fa50a355SKonstantin Belousov 		    MAP_ASLR_IGNSTART);
10728056df6eSAlan Cox 		vm_map_unlock(map);
1073af9ec885SJohn Dyson 	} else {
1074878adb85SBjoern A. Zeeb 		error = vmspace_exec(p, sv_minuser, sv->sv_maxuser);
107589b57fcfSKonstantin Belousov 		if (error)
107689b57fcfSKonstantin Belousov 			return (error);
10775e20c11fSAlan Cox 		vmspace = p->p_vmspace;
107805ba50f5SJake Burkholder 		map = &vmspace->vm_map;
1079af9ec885SJohn Dyson 	}
1080fa50a355SKonstantin Belousov 	map->flags |= imgp->map_flags;
108126f9a767SRodney W. Grimes 
10826297a3d8SKonstantin Belousov 	/* Map a shared page */
10836297a3d8SKonstantin Belousov 	obj = sv->sv_shared_page_obj;
10846297a3d8SKonstantin Belousov 	if (obj != NULL) {
10856297a3d8SKonstantin Belousov 		vm_object_reference(obj);
10866297a3d8SKonstantin Belousov 		error = vm_map_fixed(map, obj, 0,
10876297a3d8SKonstantin Belousov 		    sv->sv_shared_page_base, sv->sv_shared_page_len,
10881e65d73cSKonstantin Belousov 		    VM_PROT_READ | VM_PROT_EXECUTE,
10891e65d73cSKonstantin Belousov 		    VM_PROT_READ | VM_PROT_EXECUTE,
10901e65d73cSKonstantin Belousov 		    MAP_INHERIT_SHARE | MAP_ACC_NO_CHARGE);
1091467b3975SKonstantin Belousov 		if (error != KERN_SUCCESS) {
10926297a3d8SKonstantin Belousov 			vm_object_deallocate(obj);
1093467b3975SKonstantin Belousov 			return (vm_mmap_to_errno(error));
10946297a3d8SKonstantin Belousov 		}
10956297a3d8SKonstantin Belousov 	}
10966297a3d8SKonstantin Belousov 
109726f9a767SRodney W. Grimes 	/* Allocate a new stack */
1098316b3843SKonstantin Belousov 	if (imgp->stack_sz != 0) {
1099fe8a824cSKonstantin Belousov 		ssiz = trunc_page(imgp->stack_sz);
1100316b3843SKonstantin Belousov 		PROC_LOCK(p);
1101f6f6d240SMateusz Guzik 		lim_rlimit_proc(p, RLIMIT_STACK, &rlim_stack);
1102316b3843SKonstantin Belousov 		PROC_UNLOCK(p);
1103316b3843SKonstantin Belousov 		if (ssiz > rlim_stack.rlim_max)
1104316b3843SKonstantin Belousov 			ssiz = rlim_stack.rlim_max;
1105316b3843SKonstantin Belousov 		if (ssiz > rlim_stack.rlim_cur) {
1106316b3843SKonstantin Belousov 			rlim_stack.rlim_cur = ssiz;
1107316b3843SKonstantin Belousov 			kern_setrlimit(curthread, RLIMIT_STACK, &rlim_stack);
1108316b3843SKonstantin Belousov 		}
1109316b3843SKonstantin Belousov 	} else if (sv->sv_maxssiz != NULL) {
111059d8f3ffSJohn Baldwin 		ssiz = *sv->sv_maxssiz;
1111316b3843SKonstantin Belousov 	} else {
111259d8f3ffSJohn Baldwin 		ssiz = maxssiz;
1113316b3843SKonstantin Belousov 	}
111401c3ba97SKonstantin Belousov 	imgp->eff_stack_sz = lim_cur(curthread, RLIMIT_STACK);
111501c3ba97SKonstantin Belousov 	if (ssiz < imgp->eff_stack_sz)
1116fc83c5a7SKonstantin Belousov 		imgp->eff_stack_sz = ssiz;
111759d8f3ffSJohn Baldwin 	stack_addr = sv->sv_usrstack - ssiz;
111859d8f3ffSJohn Baldwin 	error = vm_map_stack(map, stack_addr, (vm_size_t)ssiz,
11196297a3d8SKonstantin Belousov 	    obj != NULL && imgp->stack_prot != 0 ? imgp->stack_prot :
1120467b3975SKonstantin Belousov 	    sv->sv_stackprot, VM_PROT_ALL, MAP_STACK_GROWS_DOWN);
1121467b3975SKonstantin Belousov 	if (error != KERN_SUCCESS)
1122467b3975SKonstantin Belousov 		return (vm_mmap_to_errno(error));
11232267af78SJulian Elischer 
112478960940SAlan Cox 	/*
112578960940SAlan Cox 	 * vm_ssize and vm_maxsaddr are somewhat antiquated concepts, but they
112678960940SAlan Cox 	 * are still used to enforce the stack rlimit on the process stack.
11272267af78SJulian Elischer 	 */
1128cbc89bfbSPaul Saab 	vmspace->vm_ssize = sgrowsiz >> PAGE_SHIFT;
11296ef12002SKonstantin Belousov 	vmspace->vm_maxsaddr = (char *)stack_addr;
113026f9a767SRodney W. Grimes 
113126f9a767SRodney W. Grimes 	return (0);
113226f9a767SRodney W. Grimes }
113326f9a767SRodney W. Grimes 
113426f9a767SRodney W. Grimes /*
1135873fbcd7SRobert Watson  * Copy out argument and environment strings from the old process address
1136873fbcd7SRobert Watson  * space into the temporary string buffer.
113726f9a767SRodney W. Grimes  */
113826f9a767SRodney W. Grimes int
113912e69f96SBrooks Davis exec_copyin_args(struct image_args *args, const char *fname,
1140610ecfe0SMaxim Sobolev     enum uio_seg segflg, char **argv, char **envv)
114126f9a767SRodney W. Grimes {
1142f373437aSBrooks Davis 	u_long arg, env;
1143ecbb00a2SDoug Rabson 	int error;
114426f9a767SRodney W. Grimes 
1145610ecfe0SMaxim Sobolev 	bzero(args, sizeof(*args));
1146610ecfe0SMaxim Sobolev 	if (argv == NULL)
1147610ecfe0SMaxim Sobolev 		return (EFAULT);
11482af6e14dSAlan Cox 
114926f9a767SRodney W. Grimes 	/*
11502af6e14dSAlan Cox 	 * Allocate demand-paged memory for the file name, argument, and
11512af6e14dSAlan Cox 	 * environment strings.
115226f9a767SRodney W. Grimes 	 */
11532af6e14dSAlan Cox 	error = exec_alloc_args(args);
11542af6e14dSAlan Cox 	if (error != 0)
11552af6e14dSAlan Cox 		return (error);
11569e4e5114SAlan Cox 
1157610ecfe0SMaxim Sobolev 	/*
1158610ecfe0SMaxim Sobolev 	 * Copy the file name.
1159610ecfe0SMaxim Sobolev 	 */
1160f373437aSBrooks Davis 	error = exec_args_add_fname(args, fname, segflg);
1161c30af532SMaxim Sobolev 	if (error != 0)
116268ff3c24SStephan Uphoff 		goto err_exit;
116326f9a767SRodney W. Grimes 
1164610ecfe0SMaxim Sobolev 	/*
1165610ecfe0SMaxim Sobolev 	 * extract arguments first
1166610ecfe0SMaxim Sobolev 	 */
11670a2c94b8SKonstantin Belousov 	for (;;) {
1168f373437aSBrooks Davis 		error = fueword(argv++, &arg);
11690a2c94b8SKonstantin Belousov 		if (error == -1) {
117068ff3c24SStephan Uphoff 			error = EFAULT;
117168ff3c24SStephan Uphoff 			goto err_exit;
117268ff3c24SStephan Uphoff 		}
1173f373437aSBrooks Davis 		if (arg == 0)
11740a2c94b8SKonstantin Belousov 			break;
1175f373437aSBrooks Davis 		error = exec_args_add_arg(args, (char *)(uintptr_t)arg,
1176f373437aSBrooks Davis 		    UIO_USERSPACE);
1177f373437aSBrooks Davis 		if (error != 0)
117868ff3c24SStephan Uphoff 			goto err_exit;
1179610ecfe0SMaxim Sobolev 	}
1180b9df5231SPoul-Henning Kamp 
118126f9a767SRodney W. Grimes 	/*
118226f9a767SRodney W. Grimes 	 * extract environment strings
118326f9a767SRodney W. Grimes 	 */
11840fd1a014SDavid Greenman 	if (envv) {
11850a2c94b8SKonstantin Belousov 		for (;;) {
1186f373437aSBrooks Davis 			error = fueword(envv++, &env);
11870a2c94b8SKonstantin Belousov 			if (error == -1) {
118868ff3c24SStephan Uphoff 				error = EFAULT;
118968ff3c24SStephan Uphoff 				goto err_exit;
119068ff3c24SStephan Uphoff 			}
1191f373437aSBrooks Davis 			if (env == 0)
11920a2c94b8SKonstantin Belousov 				break;
1193f373437aSBrooks Davis 			error = exec_args_add_env(args,
1194f373437aSBrooks Davis 			    (char *)(uintptr_t)env, UIO_USERSPACE);
1195f373437aSBrooks Davis 			if (error != 0)
119668ff3c24SStephan Uphoff 				goto err_exit;
11970fd1a014SDavid Greenman 		}
11980fd1a014SDavid Greenman 	}
119926f9a767SRodney W. Grimes 
120026f9a767SRodney W. Grimes 	return (0);
120168ff3c24SStephan Uphoff 
120268ff3c24SStephan Uphoff err_exit:
120368ff3c24SStephan Uphoff 	exec_free_args(args);
120468ff3c24SStephan Uphoff 	return (error);
120526f9a767SRodney W. Grimes }
120626f9a767SRodney W. Grimes 
1207457f7e23SEd Schouten int
1208457f7e23SEd Schouten exec_copyin_data_fds(struct thread *td, struct image_args *args,
1209457f7e23SEd Schouten     const void *data, size_t datalen, const int *fds, size_t fdslen)
1210457f7e23SEd Schouten {
1211457f7e23SEd Schouten 	struct filedesc *ofdp;
1212457f7e23SEd Schouten 	const char *p;
1213457f7e23SEd Schouten 	int *kfds;
1214457f7e23SEd Schouten 	int error;
1215457f7e23SEd Schouten 
1216457f7e23SEd Schouten 	memset(args, '\0', sizeof(*args));
1217457f7e23SEd Schouten 	ofdp = td->td_proc->p_fd;
1218457f7e23SEd Schouten 	if (datalen >= ARG_MAX || fdslen > ofdp->fd_lastfile + 1)
1219457f7e23SEd Schouten 		return (E2BIG);
1220457f7e23SEd Schouten 	error = exec_alloc_args(args);
1221457f7e23SEd Schouten 	if (error != 0)
1222457f7e23SEd Schouten 		return (error);
1223457f7e23SEd Schouten 
1224457f7e23SEd Schouten 	args->begin_argv = args->buf;
1225457f7e23SEd Schouten 	args->stringspace = ARG_MAX;
1226457f7e23SEd Schouten 
1227457f7e23SEd Schouten 	if (datalen > 0) {
1228457f7e23SEd Schouten 		/*
1229457f7e23SEd Schouten 		 * Argument buffer has been provided. Copy it into the
1230457f7e23SEd Schouten 		 * kernel as a single string and add a terminating null
1231457f7e23SEd Schouten 		 * byte.
1232457f7e23SEd Schouten 		 */
1233457f7e23SEd Schouten 		error = copyin(data, args->begin_argv, datalen);
1234457f7e23SEd Schouten 		if (error != 0)
1235457f7e23SEd Schouten 			goto err_exit;
1236457f7e23SEd Schouten 		args->begin_argv[datalen] = '\0';
1237457f7e23SEd Schouten 		args->endp = args->begin_argv + datalen + 1;
1238457f7e23SEd Schouten 		args->stringspace -= datalen + 1;
1239457f7e23SEd Schouten 
1240457f7e23SEd Schouten 		/*
1241457f7e23SEd Schouten 		 * Traditional argument counting. Count the number of
1242457f7e23SEd Schouten 		 * null bytes.
1243457f7e23SEd Schouten 		 */
1244457f7e23SEd Schouten 		for (p = args->begin_argv; p < args->endp; ++p)
1245457f7e23SEd Schouten 			if (*p == '\0')
1246457f7e23SEd Schouten 				++args->argc;
1247457f7e23SEd Schouten 	} else {
1248457f7e23SEd Schouten 		/* No argument buffer provided. */
1249457f7e23SEd Schouten 		args->endp = args->begin_argv;
1250457f7e23SEd Schouten 	}
1251457f7e23SEd Schouten 
1252457f7e23SEd Schouten 	/* Create new file descriptor table. */
1253457f7e23SEd Schouten 	kfds = malloc(fdslen * sizeof(int), M_TEMP, M_WAITOK);
1254457f7e23SEd Schouten 	error = copyin(fds, kfds, fdslen * sizeof(int));
1255457f7e23SEd Schouten 	if (error != 0) {
1256457f7e23SEd Schouten 		free(kfds, M_TEMP);
1257457f7e23SEd Schouten 		goto err_exit;
1258457f7e23SEd Schouten 	}
1259457f7e23SEd Schouten 	error = fdcopy_remapped(ofdp, kfds, fdslen, &args->fdp);
1260457f7e23SEd Schouten 	free(kfds, M_TEMP);
1261457f7e23SEd Schouten 	if (error != 0)
1262457f7e23SEd Schouten 		goto err_exit;
1263457f7e23SEd Schouten 
1264457f7e23SEd Schouten 	return (0);
1265457f7e23SEd Schouten err_exit:
1266457f7e23SEd Schouten 	exec_free_args(args);
1267457f7e23SEd Schouten 	return (error);
1268457f7e23SEd Schouten }
1269457f7e23SEd Schouten 
1270ec492b13SMark Johnston struct exec_args_kva {
1271ec492b13SMark Johnston 	vm_offset_t addr;
1272c6a4ba5aSMark Johnston 	u_int gen;
1273ec492b13SMark Johnston 	SLIST_ENTRY(exec_args_kva) next;
1274ec492b13SMark Johnston };
1275ec492b13SMark Johnston 
12762bf95012SAndrew Turner DPCPU_DEFINE_STATIC(struct exec_args_kva *, exec_args_kva);
1277ec492b13SMark Johnston 
1278ec492b13SMark Johnston static SLIST_HEAD(, exec_args_kva) exec_args_kva_freelist;
1279ec492b13SMark Johnston static struct mtx exec_args_kva_mtx;
1280c6a4ba5aSMark Johnston static u_int exec_args_gen;
1281ec492b13SMark Johnston 
1282ec492b13SMark Johnston static void
1283ec492b13SMark Johnston exec_prealloc_args_kva(void *arg __unused)
1284ec492b13SMark Johnston {
1285ec492b13SMark Johnston 	struct exec_args_kva *argkva;
1286ec492b13SMark Johnston 	u_int i;
1287ec492b13SMark Johnston 
1288ec492b13SMark Johnston 	SLIST_INIT(&exec_args_kva_freelist);
1289ec492b13SMark Johnston 	mtx_init(&exec_args_kva_mtx, "exec args kva", NULL, MTX_DEF);
1290ec492b13SMark Johnston 	for (i = 0; i < exec_map_entries; i++) {
1291ec492b13SMark Johnston 		argkva = malloc(sizeof(*argkva), M_PARGS, M_WAITOK);
1292ec492b13SMark Johnston 		argkva->addr = kmap_alloc_wait(exec_map, exec_map_entry_size);
1293c6a4ba5aSMark Johnston 		argkva->gen = exec_args_gen;
1294ec492b13SMark Johnston 		SLIST_INSERT_HEAD(&exec_args_kva_freelist, argkva, next);
1295ec492b13SMark Johnston 	}
1296ec492b13SMark Johnston }
1297ec492b13SMark Johnston SYSINIT(exec_args_kva, SI_SUB_EXEC, SI_ORDER_ANY, exec_prealloc_args_kva, NULL);
1298ec492b13SMark Johnston 
1299ec492b13SMark Johnston static vm_offset_t
1300ec492b13SMark Johnston exec_alloc_args_kva(void **cookie)
1301ec492b13SMark Johnston {
1302ec492b13SMark Johnston 	struct exec_args_kva *argkva;
1303ec492b13SMark Johnston 
1304ec492b13SMark Johnston 	argkva = (void *)atomic_readandclear_ptr(
1305ec492b13SMark Johnston 	    (uintptr_t *)DPCPU_PTR(exec_args_kva));
1306ec492b13SMark Johnston 	if (argkva == NULL) {
1307ec492b13SMark Johnston 		mtx_lock(&exec_args_kva_mtx);
1308ec492b13SMark Johnston 		while ((argkva = SLIST_FIRST(&exec_args_kva_freelist)) == NULL)
1309ec492b13SMark Johnston 			(void)mtx_sleep(&exec_args_kva_freelist,
1310ec492b13SMark Johnston 			    &exec_args_kva_mtx, 0, "execkva", 0);
1311ec492b13SMark Johnston 		SLIST_REMOVE_HEAD(&exec_args_kva_freelist, next);
1312ec492b13SMark Johnston 		mtx_unlock(&exec_args_kva_mtx);
1313ec492b13SMark Johnston 	}
1314ec492b13SMark Johnston 	*(struct exec_args_kva **)cookie = argkva;
1315ec492b13SMark Johnston 	return (argkva->addr);
1316ec492b13SMark Johnston }
1317ec492b13SMark Johnston 
1318ec492b13SMark Johnston static void
1319c6a4ba5aSMark Johnston exec_release_args_kva(struct exec_args_kva *argkva, u_int gen)
1320ec492b13SMark Johnston {
1321ec492b13SMark Johnston 	vm_offset_t base;
1322ec492b13SMark Johnston 
1323ec492b13SMark Johnston 	base = argkva->addr;
1324c6a4ba5aSMark Johnston 	if (argkva->gen != gen) {
13253e7cb27cSAlan Cox 		(void)vm_map_madvise(exec_map, base, base + exec_map_entry_size,
1326c6a4ba5aSMark Johnston 		    MADV_FREE);
1327c6a4ba5aSMark Johnston 		argkva->gen = gen;
1328c6a4ba5aSMark Johnston 	}
1329ec492b13SMark Johnston 	if (!atomic_cmpset_ptr((uintptr_t *)DPCPU_PTR(exec_args_kva),
1330ec492b13SMark Johnston 	    (uintptr_t)NULL, (uintptr_t)argkva)) {
1331ec492b13SMark Johnston 		mtx_lock(&exec_args_kva_mtx);
1332ec492b13SMark Johnston 		SLIST_INSERT_HEAD(&exec_args_kva_freelist, argkva, next);
1333ec492b13SMark Johnston 		wakeup_one(&exec_args_kva_freelist);
1334ec492b13SMark Johnston 		mtx_unlock(&exec_args_kva_mtx);
1335ec492b13SMark Johnston 	}
1336ec492b13SMark Johnston }
1337ec492b13SMark Johnston 
1338c6a4ba5aSMark Johnston static void
1339c6a4ba5aSMark Johnston exec_free_args_kva(void *cookie)
1340c6a4ba5aSMark Johnston {
1341c6a4ba5aSMark Johnston 
1342c6a4ba5aSMark Johnston 	exec_release_args_kva(cookie, exec_args_gen);
1343c6a4ba5aSMark Johnston }
1344c6a4ba5aSMark Johnston 
1345c6a4ba5aSMark Johnston static void
1346c6a4ba5aSMark Johnston exec_args_kva_lowmem(void *arg __unused)
1347c6a4ba5aSMark Johnston {
1348c6a4ba5aSMark Johnston 	SLIST_HEAD(, exec_args_kva) head;
1349c6a4ba5aSMark Johnston 	struct exec_args_kva *argkva;
1350c6a4ba5aSMark Johnston 	u_int gen;
1351c6a4ba5aSMark Johnston 	int i;
1352c6a4ba5aSMark Johnston 
1353c6a4ba5aSMark Johnston 	gen = atomic_fetchadd_int(&exec_args_gen, 1) + 1;
1354c6a4ba5aSMark Johnston 
1355c6a4ba5aSMark Johnston 	/*
1356c6a4ba5aSMark Johnston 	 * Force an madvise of each KVA range. Any currently allocated ranges
1357c6a4ba5aSMark Johnston 	 * will have MADV_FREE applied once they are freed.
1358c6a4ba5aSMark Johnston 	 */
1359c6a4ba5aSMark Johnston 	SLIST_INIT(&head);
1360c6a4ba5aSMark Johnston 	mtx_lock(&exec_args_kva_mtx);
1361c6a4ba5aSMark Johnston 	SLIST_SWAP(&head, &exec_args_kva_freelist, exec_args_kva);
1362c6a4ba5aSMark Johnston 	mtx_unlock(&exec_args_kva_mtx);
1363c6a4ba5aSMark Johnston 	while ((argkva = SLIST_FIRST(&head)) != NULL) {
1364c6a4ba5aSMark Johnston 		SLIST_REMOVE_HEAD(&head, next);
1365c6a4ba5aSMark Johnston 		exec_release_args_kva(argkva, gen);
1366c6a4ba5aSMark Johnston 	}
1367c6a4ba5aSMark Johnston 
1368c6a4ba5aSMark Johnston 	CPU_FOREACH(i) {
1369c6a4ba5aSMark Johnston 		argkva = (void *)atomic_readandclear_ptr(
1370c6a4ba5aSMark Johnston 		    (uintptr_t *)DPCPU_ID_PTR(i, exec_args_kva));
1371c6a4ba5aSMark Johnston 		if (argkva != NULL)
1372c6a4ba5aSMark Johnston 			exec_release_args_kva(argkva, gen);
1373c6a4ba5aSMark Johnston 	}
1374c6a4ba5aSMark Johnston }
1375c6a4ba5aSMark Johnston EVENTHANDLER_DEFINE(vm_lowmem, exec_args_kva_lowmem, NULL,
1376c6a4ba5aSMark Johnston     EVENTHANDLER_PRI_ANY);
1377c6a4ba5aSMark Johnston 
13782af6e14dSAlan Cox /*
13792af6e14dSAlan Cox  * Allocate temporary demand-paged, zero-filled memory for the file name,
1380ec492b13SMark Johnston  * argument, and environment strings.
13812af6e14dSAlan Cox  */
13822af6e14dSAlan Cox int
13832af6e14dSAlan Cox exec_alloc_args(struct image_args *args)
13842af6e14dSAlan Cox {
13852af6e14dSAlan Cox 
1386ec492b13SMark Johnston 	args->buf = (char *)exec_alloc_args_kva(&args->bufkva);
1387ec492b13SMark Johnston 	return (0);
13882af6e14dSAlan Cox }
13892af6e14dSAlan Cox 
139069a8f9e3SAlan Cox void
1391610ecfe0SMaxim Sobolev exec_free_args(struct image_args *args)
1392610ecfe0SMaxim Sobolev {
1393610ecfe0SMaxim Sobolev 
139469a8f9e3SAlan Cox 	if (args->buf != NULL) {
1395ec492b13SMark Johnston 		exec_free_args_kva(args->bufkva);
1396610ecfe0SMaxim Sobolev 		args->buf = NULL;
1397610ecfe0SMaxim Sobolev 	}
1398a14a9498SAlan Cox 	if (args->fname_buf != NULL) {
1399a14a9498SAlan Cox 		free(args->fname_buf, M_TEMP);
1400a14a9498SAlan Cox 		args->fname_buf = NULL;
1401a14a9498SAlan Cox 	}
1402457f7e23SEd Schouten 	if (args->fdp != NULL)
1403457f7e23SEd Schouten 		fdescfree_remapped(args->fdp);
1404610ecfe0SMaxim Sobolev }
1405610ecfe0SMaxim Sobolev 
140626f9a767SRodney W. Grimes /*
1407f373437aSBrooks Davis  * A set to functions to fill struct image args.
1408f373437aSBrooks Davis  *
1409f373437aSBrooks Davis  * NOTE: exec_args_add_fname() must be called (possibly with a NULL
1410f373437aSBrooks Davis  * fname) before the other functions.  All exec_args_add_arg() calls must
1411f373437aSBrooks Davis  * be made before any exec_args_add_env() calls.  exec_args_adjust_args()
1412f373437aSBrooks Davis  * may be called any time after exec_args_add_fname().
1413f373437aSBrooks Davis  *
1414f373437aSBrooks Davis  * exec_args_add_fname() - install path to be executed
1415f373437aSBrooks Davis  * exec_args_add_arg() - append an argument string
1416f373437aSBrooks Davis  * exec_args_add_env() - append an env string
1417f373437aSBrooks Davis  * exec_args_adjust_args() - adjust location of the argument list to
1418f373437aSBrooks Davis  *                           allow new arguments to be prepended
1419f373437aSBrooks Davis  */
1420f373437aSBrooks Davis int
1421f373437aSBrooks Davis exec_args_add_fname(struct image_args *args, const char *fname,
1422f373437aSBrooks Davis     enum uio_seg segflg)
1423f373437aSBrooks Davis {
1424f373437aSBrooks Davis 	int error;
1425f373437aSBrooks Davis 	size_t length;
1426f373437aSBrooks Davis 
1427f373437aSBrooks Davis 	KASSERT(args->fname == NULL, ("fname already appended"));
1428f373437aSBrooks Davis 	KASSERT(args->endp == NULL, ("already appending to args"));
1429f373437aSBrooks Davis 
1430f373437aSBrooks Davis 	if (fname != NULL) {
1431f373437aSBrooks Davis 		args->fname = args->buf;
1432f373437aSBrooks Davis 		error = segflg == UIO_SYSSPACE ?
1433f373437aSBrooks Davis 		    copystr(fname, args->fname, PATH_MAX, &length) :
1434f373437aSBrooks Davis 		    copyinstr(fname, args->fname, PATH_MAX, &length);
1435f373437aSBrooks Davis 		if (error != 0)
1436f373437aSBrooks Davis 			return (error == ENAMETOOLONG ? E2BIG : error);
1437f373437aSBrooks Davis 	} else
1438f373437aSBrooks Davis 		length = 0;
1439f373437aSBrooks Davis 
1440f373437aSBrooks Davis 	/* Set up for _arg_*()/_env_*() */
1441f373437aSBrooks Davis 	args->endp = args->buf + length;
1442f373437aSBrooks Davis 	/* begin_argv must be set and kept updated */
1443f373437aSBrooks Davis 	args->begin_argv = args->endp;
1444f373437aSBrooks Davis 	KASSERT(exec_map_entry_size - length >= ARG_MAX,
1445f373437aSBrooks Davis 	    ("too little space remaining for arguments %zu < %zu",
1446f373437aSBrooks Davis 	    exec_map_entry_size - length, (size_t)ARG_MAX));
1447f373437aSBrooks Davis 	args->stringspace = ARG_MAX;
1448f373437aSBrooks Davis 
1449f373437aSBrooks Davis 	return (0);
1450f373437aSBrooks Davis }
1451f373437aSBrooks Davis 
1452f373437aSBrooks Davis static int
1453f373437aSBrooks Davis exec_args_add_str(struct image_args *args, const char *str,
1454f373437aSBrooks Davis     enum uio_seg segflg, int *countp)
1455f373437aSBrooks Davis {
1456f373437aSBrooks Davis 	int error;
1457f373437aSBrooks Davis 	size_t length;
1458f373437aSBrooks Davis 
1459f373437aSBrooks Davis 	KASSERT(args->endp != NULL, ("endp not initialized"));
1460f373437aSBrooks Davis 	KASSERT(args->begin_argv != NULL, ("begin_argp not initialized"));
1461f373437aSBrooks Davis 
1462f373437aSBrooks Davis 	error = (segflg == UIO_SYSSPACE) ?
1463f373437aSBrooks Davis 	    copystr(str, args->endp, args->stringspace, &length) :
1464f373437aSBrooks Davis 	    copyinstr(str, args->endp, args->stringspace, &length);
1465f373437aSBrooks Davis 	if (error != 0)
1466f373437aSBrooks Davis 		return (error == ENAMETOOLONG ? E2BIG : error);
1467f373437aSBrooks Davis 	args->stringspace -= length;
1468f373437aSBrooks Davis 	args->endp += length;
1469f373437aSBrooks Davis 	(*countp)++;
1470f373437aSBrooks Davis 
1471f373437aSBrooks Davis 	return (0);
1472f373437aSBrooks Davis }
1473f373437aSBrooks Davis 
1474f373437aSBrooks Davis int
1475f373437aSBrooks Davis exec_args_add_arg(struct image_args *args, const char *argp,
1476f373437aSBrooks Davis     enum uio_seg segflg)
1477f373437aSBrooks Davis {
1478f373437aSBrooks Davis 
1479f373437aSBrooks Davis 	KASSERT(args->envc == 0, ("appending args after env"));
1480f373437aSBrooks Davis 
1481f373437aSBrooks Davis 	return (exec_args_add_str(args, argp, segflg, &args->argc));
1482f373437aSBrooks Davis }
1483f373437aSBrooks Davis 
1484f373437aSBrooks Davis int
1485f373437aSBrooks Davis exec_args_add_env(struct image_args *args, const char *envp,
1486f373437aSBrooks Davis     enum uio_seg segflg)
1487f373437aSBrooks Davis {
1488f373437aSBrooks Davis 
1489f373437aSBrooks Davis 	if (args->envc == 0)
1490f373437aSBrooks Davis 		args->begin_envv = args->endp;
1491f373437aSBrooks Davis 
1492f373437aSBrooks Davis 	return (exec_args_add_str(args, envp, segflg, &args->envc));
1493f373437aSBrooks Davis }
1494f373437aSBrooks Davis 
1495f373437aSBrooks Davis int
1496f373437aSBrooks Davis exec_args_adjust_args(struct image_args *args, size_t consume, ssize_t extend)
1497f373437aSBrooks Davis {
1498f373437aSBrooks Davis 	ssize_t offset;
1499f373437aSBrooks Davis 
1500f373437aSBrooks Davis 	KASSERT(args->endp != NULL, ("endp not initialized"));
1501f373437aSBrooks Davis 	KASSERT(args->begin_argv != NULL, ("begin_argp not initialized"));
1502f373437aSBrooks Davis 
1503f373437aSBrooks Davis 	offset = extend - consume;
1504f373437aSBrooks Davis 	if (args->stringspace < offset)
1505f373437aSBrooks Davis 		return (E2BIG);
1506f373437aSBrooks Davis 	memmove(args->begin_argv + extend, args->begin_argv + consume,
1507f373437aSBrooks Davis 	    args->endp - args->begin_argv + consume);
1508f373437aSBrooks Davis 	if (args->envc > 0)
1509f373437aSBrooks Davis 		args->begin_envv += offset;
1510f373437aSBrooks Davis 	args->endp += offset;
1511f373437aSBrooks Davis 	args->stringspace -= offset;
1512f373437aSBrooks Davis 	return (0);
1513f373437aSBrooks Davis }
1514f373437aSBrooks Davis 
1515f373437aSBrooks Davis char *
1516f373437aSBrooks Davis exec_args_get_begin_envv(struct image_args *args)
1517f373437aSBrooks Davis {
1518f373437aSBrooks Davis 
1519f373437aSBrooks Davis 	KASSERT(args->endp != NULL, ("endp not initialized"));
1520f373437aSBrooks Davis 
1521f373437aSBrooks Davis 	if (args->envc > 0)
1522f373437aSBrooks Davis 		return (args->begin_envv);
1523f373437aSBrooks Davis 	return (args->endp);
1524f373437aSBrooks Davis }
1525f373437aSBrooks Davis 
1526f373437aSBrooks Davis /*
1527873fbcd7SRobert Watson  * Copy strings out to the new process address space, constructing new arg
1528873fbcd7SRobert Watson  * and env vector tables. Return a pointer to the base so that it can be used
1529873fbcd7SRobert Watson  * as the initial stack pointer.
153026f9a767SRodney W. Grimes  */
153103b0d68cSJohn Baldwin int
153231174518SJohn Baldwin exec_copyout_strings(struct image_params *imgp, uintptr_t *stack_base)
153326f9a767SRodney W. Grimes {
153426f9a767SRodney W. Grimes 	int argc, envc;
153526f9a767SRodney W. Grimes 	char **vectp;
153688b124ceSKonstantin Belousov 	char *stringp;
153731174518SJohn Baldwin 	uintptr_t destp, ustringp;
153893f6448cSDavid Greenman 	struct ps_strings *arginfo;
1539f3bec5d7SJake Burkholder 	struct proc *p;
15403ff06357SKonstantin Belousov 	size_t execpath_len;
154103b0d68cSJohn Baldwin 	int error, szsigcode, szps;
1542ee235befSKonstantin Belousov 	char canary[sizeof(long) * 8];
154326f9a767SRodney W. Grimes 
1544ee235befSKonstantin Belousov 	szps = sizeof(pagesizes[0]) * MAXPAGESIZES;
154526f9a767SRodney W. Grimes 	/*
154626f9a767SRodney W. Grimes 	 * Calculate string base and vector table pointers.
1547d66a5066SPeter Wemm 	 * Also deal with signal trampoline code for this exec type.
154826f9a767SRodney W. Grimes 	 */
15493ff06357SKonstantin Belousov 	if (imgp->execpath != NULL && imgp->auxargs != NULL)
15503ff06357SKonstantin Belousov 		execpath_len = strlen(imgp->execpath) + 1;
15513ff06357SKonstantin Belousov 	else
15523ff06357SKonstantin Belousov 		execpath_len = 0;
1553f3bec5d7SJake Burkholder 	p = imgp->proc;
1554f3bec5d7SJake Burkholder 	szsigcode = 0;
155505ba50f5SJake Burkholder 	arginfo = (struct ps_strings *)p->p_sysent->sv_psstrings;
15566297a3d8SKonstantin Belousov 	if (p->p_sysent->sv_sigcode_base == 0) {
1557f3bec5d7SJake Burkholder 		if (p->p_sysent->sv_szsigcode != NULL)
1558f3bec5d7SJake Burkholder 			szsigcode = *(p->p_sysent->sv_szsigcode);
15596297a3d8SKonstantin Belousov 	}
156088b124ceSKonstantin Belousov 	destp =	(uintptr_t)arginfo;
15611ed012f9SPeter Wemm 
156226f9a767SRodney W. Grimes 	/*
1563d66a5066SPeter Wemm 	 * install sigcode
1564d66a5066SPeter Wemm 	 */
156588b124ceSKonstantin Belousov 	if (szsigcode != 0) {
156688b124ceSKonstantin Belousov 		destp -= szsigcode;
156788b124ceSKonstantin Belousov 		destp = rounddown2(destp, sizeof(void *));
156803b0d68cSJohn Baldwin 		error = copyout(p->p_sysent->sv_sigcode, (void *)destp,
156903b0d68cSJohn Baldwin 		    szsigcode);
157003b0d68cSJohn Baldwin 		if (error != 0)
157103b0d68cSJohn Baldwin 			return (error);
157288b124ceSKonstantin Belousov 	}
1573d66a5066SPeter Wemm 
1574d66a5066SPeter Wemm 	/*
15753ff06357SKonstantin Belousov 	 * Copy the image path for the rtld.
15763ff06357SKonstantin Belousov 	 */
15773ff06357SKonstantin Belousov 	if (execpath_len != 0) {
157888b124ceSKonstantin Belousov 		destp -= execpath_len;
1579d92da759SBrooks Davis 		destp = rounddown2(destp, sizeof(void *));
158088b124ceSKonstantin Belousov 		imgp->execpathp = destp;
158103b0d68cSJohn Baldwin 		error = copyout(imgp->execpath, (void *)destp, execpath_len);
158203b0d68cSJohn Baldwin 		if (error != 0)
158303b0d68cSJohn Baldwin 			return (error);
15843ff06357SKonstantin Belousov 	}
15853ff06357SKonstantin Belousov 
15863ff06357SKonstantin Belousov 	/*
1587ee235befSKonstantin Belousov 	 * Prepare the canary for SSP.
1588ee235befSKonstantin Belousov 	 */
1589ee235befSKonstantin Belousov 	arc4rand(canary, sizeof(canary), 0);
159088b124ceSKonstantin Belousov 	destp -= sizeof(canary);
159188b124ceSKonstantin Belousov 	imgp->canary = destp;
159203b0d68cSJohn Baldwin 	error = copyout(canary, (void *)destp, sizeof(canary));
159303b0d68cSJohn Baldwin 	if (error != 0)
159403b0d68cSJohn Baldwin 		return (error);
1595ee235befSKonstantin Belousov 	imgp->canarylen = sizeof(canary);
1596ee235befSKonstantin Belousov 
1597ee235befSKonstantin Belousov 	/*
1598ee235befSKonstantin Belousov 	 * Prepare the pagesizes array.
1599ee235befSKonstantin Belousov 	 */
160088b124ceSKonstantin Belousov 	destp -= szps;
160188b124ceSKonstantin Belousov 	destp = rounddown2(destp, sizeof(void *));
160288b124ceSKonstantin Belousov 	imgp->pagesizes = destp;
160303b0d68cSJohn Baldwin 	error = copyout(pagesizes, (void *)destp, szps);
160403b0d68cSJohn Baldwin 	if (error != 0)
160503b0d68cSJohn Baldwin 		return (error);
1606ee235befSKonstantin Belousov 	imgp->pagesizeslen = szps;
1607ee235befSKonstantin Belousov 
160831174518SJohn Baldwin 	/*
160931174518SJohn Baldwin 	 * Allocate room for the argument and environment strings.
161031174518SJohn Baldwin 	 */
161188b124ceSKonstantin Belousov 	destp -= ARG_MAX - imgp->args->stringspace;
161288b124ceSKonstantin Belousov 	destp = rounddown2(destp, sizeof(void *));
161331174518SJohn Baldwin 	ustringp = destp;
161488b124ceSKonstantin Belousov 
1615fc83c5a7SKonstantin Belousov 	if (imgp->sysent->sv_stackgap != NULL)
161631174518SJohn Baldwin 		imgp->sysent->sv_stackgap(imgp, &destp);
1617fc83c5a7SKonstantin Belousov 
161803b0d68cSJohn Baldwin 	if (imgp->auxargs) {
1619d8010b11SJohn Baldwin 		/*
1620d8010b11SJohn Baldwin 		 * Allocate room on the stack for the ELF auxargs
1621d8010b11SJohn Baldwin 		 * array.  It has up to AT_COUNT entries.
1622d8010b11SJohn Baldwin 		 */
1623d8010b11SJohn Baldwin 		destp -= AT_COUNT * sizeof(Elf_Auxinfo);
1624d8010b11SJohn Baldwin 		destp = rounddown2(destp, sizeof(void *));
162503b0d68cSJohn Baldwin 	}
162626f9a767SRodney W. Grimes 
162731174518SJohn Baldwin 	vectp = (char **)destp;
162831174518SJohn Baldwin 
162926f9a767SRodney W. Grimes 	/*
163073c8686eSJohn Baldwin 	 * Allocate room for the argv[] and env vectors including the
163173c8686eSJohn Baldwin 	 * terminating NULL pointers.
163273c8686eSJohn Baldwin 	 */
163373c8686eSJohn Baldwin 	vectp -= imgp->args->argc + 1 + imgp->args->envc + 1;
163473c8686eSJohn Baldwin 
163573c8686eSJohn Baldwin 	/*
163626f9a767SRodney W. Grimes 	 * vectp also becomes our initial stack base
163726f9a767SRodney W. Grimes 	 */
163831174518SJohn Baldwin 	*stack_base = (uintptr_t)vectp;
163926f9a767SRodney W. Grimes 
1640610ecfe0SMaxim Sobolev 	stringp = imgp->args->begin_argv;
1641610ecfe0SMaxim Sobolev 	argc = imgp->args->argc;
1642610ecfe0SMaxim Sobolev 	envc = imgp->args->envc;
164326f9a767SRodney W. Grimes 
164493f6448cSDavid Greenman 	/*
16453aed948bSDavid Greenman 	 * Copy out strings - arguments and environment.
164693f6448cSDavid Greenman 	 */
164731174518SJohn Baldwin 	error = copyout(stringp, (void *)ustringp,
164803b0d68cSJohn Baldwin 	    ARG_MAX - imgp->args->stringspace);
164903b0d68cSJohn Baldwin 	if (error != 0)
165003b0d68cSJohn Baldwin 		return (error);
165193f6448cSDavid Greenman 
165293f6448cSDavid Greenman 	/*
16533aed948bSDavid Greenman 	 * Fill in "ps_strings" struct for ps, w, etc.
16543aed948bSDavid Greenman 	 */
165503b0d68cSJohn Baldwin 	if (suword(&arginfo->ps_argvstr, (long)(intptr_t)vectp) != 0 ||
165603b0d68cSJohn Baldwin 	    suword32(&arginfo->ps_nargvstr, argc) != 0)
165703b0d68cSJohn Baldwin 		return (EFAULT);
16583aed948bSDavid Greenman 
16593aed948bSDavid Greenman 	/*
16603aed948bSDavid Greenman 	 * Fill in argument portion of vector table.
166193f6448cSDavid Greenman 	 */
166226f9a767SRodney W. Grimes 	for (; argc > 0; --argc) {
166331174518SJohn Baldwin 		if (suword(vectp++, ustringp) != 0)
166403b0d68cSJohn Baldwin 			return (EFAULT);
16653aed948bSDavid Greenman 		while (*stringp++ != 0)
166631174518SJohn Baldwin 			ustringp++;
166731174518SJohn Baldwin 		ustringp++;
166826f9a767SRodney W. Grimes 	}
166926f9a767SRodney W. Grimes 
16701a6e52d0SJeroen Ruigrok van der Werven 	/* a null vector table pointer separates the argp's from the envp's */
167103b0d68cSJohn Baldwin 	if (suword(vectp++, 0) != 0)
167203b0d68cSJohn Baldwin 		return (EFAULT);
167326f9a767SRodney W. Grimes 
167403b0d68cSJohn Baldwin 	if (suword(&arginfo->ps_envstr, (long)(intptr_t)vectp) != 0 ||
167503b0d68cSJohn Baldwin 	    suword32(&arginfo->ps_nenvstr, envc) != 0)
167603b0d68cSJohn Baldwin 		return (EFAULT);
167793f6448cSDavid Greenman 
167893f6448cSDavid Greenman 	/*
16793aed948bSDavid Greenman 	 * Fill in environment portion of vector table.
168093f6448cSDavid Greenman 	 */
168126f9a767SRodney W. Grimes 	for (; envc > 0; --envc) {
168231174518SJohn Baldwin 		if (suword(vectp++, ustringp) != 0)
168303b0d68cSJohn Baldwin 			return (EFAULT);
16843aed948bSDavid Greenman 		while (*stringp++ != 0)
168531174518SJohn Baldwin 			ustringp++;
168631174518SJohn Baldwin 		ustringp++;
168726f9a767SRodney W. Grimes 	}
168826f9a767SRodney W. Grimes 
168926f9a767SRodney W. Grimes 	/* end of vector table is a null pointer */
169003b0d68cSJohn Baldwin 	if (suword(vectp, 0) != 0)
169103b0d68cSJohn Baldwin 		return (EFAULT);
169226f9a767SRodney W. Grimes 
1693d8010b11SJohn Baldwin 	if (imgp->auxargs) {
1694d8010b11SJohn Baldwin 		vectp++;
1695d8010b11SJohn Baldwin 		error = imgp->sysent->sv_copyout_auxargs(imgp,
1696d8010b11SJohn Baldwin 		    (uintptr_t)vectp);
1697d8010b11SJohn Baldwin 		if (error != 0)
1698d8010b11SJohn Baldwin 			return (error);
1699d8010b11SJohn Baldwin 	}
1700d8010b11SJohn Baldwin 
170103b0d68cSJohn Baldwin 	return (0);
170226f9a767SRodney W. Grimes }
170326f9a767SRodney W. Grimes 
170426f9a767SRodney W. Grimes /*
170526f9a767SRodney W. Grimes  * Check permissions of file to execute.
1706cf64863aSRobert Watson  *	Called with imgp->vp locked.
170726f9a767SRodney W. Grimes  *	Return 0 for success or error code on failure.
170826f9a767SRodney W. Grimes  */
1709c8a79999SPeter Wemm int
17103e85b721SEd Maste exec_check_permissions(struct image_params *imgp)
171126f9a767SRodney W. Grimes {
1712c52007c2SDavid Greenman 	struct vnode *vp = imgp->vp;
1713c52007c2SDavid Greenman 	struct vattr *attr = imgp->attr;
1714a854ed98SJohn Baldwin 	struct thread *td;
171578022527SKonstantin Belousov 	int error;
171626f9a767SRodney W. Grimes 
17176617724cSJeff Roberson 	td = curthread;
1718339b79b9SRobert Watson 
1719ec35c2afSRobert Watson 	/* Get file attributes */
17200359a12eSAttilio Rao 	error = VOP_GETATTR(vp, attr, td->td_ucred);
1721ec35c2afSRobert Watson 	if (error)
1722ec35c2afSRobert Watson 		return (error);
1723ec35c2afSRobert Watson 
1724339b79b9SRobert Watson #ifdef MAC
172530d239bcSRobert Watson 	error = mac_vnode_check_exec(td->td_ucred, imgp->vp, imgp);
1726339b79b9SRobert Watson 	if (error)
1727339b79b9SRobert Watson 		return (error);
1728339b79b9SRobert Watson #endif
1729339b79b9SRobert Watson 
173026f9a767SRodney W. Grimes 	/*
1731de478dd4SJaakko Heinonen 	 * 1) Check if file execution is disabled for the filesystem that
1732de478dd4SJaakko Heinonen 	 *    this file resides on.
1733de478dd4SJaakko Heinonen 	 * 2) Ensure that at least one execute bit is on. Otherwise, a
1734de478dd4SJaakko Heinonen 	 *    privileged user will always succeed, and we don't want this
1735de478dd4SJaakko Heinonen 	 *    to happen unless the file really is executable.
1736de478dd4SJaakko Heinonen 	 * 3) Ensure that the file is a regular file.
173726f9a767SRodney W. Grimes 	 */
1738c52007c2SDavid Greenman 	if ((vp->v_mount->mnt_flag & MNT_NOEXEC) ||
1739de478dd4SJaakko Heinonen 	    (attr->va_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) == 0 ||
1740a854ed98SJohn Baldwin 	    (attr->va_type != VREG))
174126f9a767SRodney W. Grimes 		return (EACCES);
174226f9a767SRodney W. Grimes 
174326f9a767SRodney W. Grimes 	/*
174426f9a767SRodney W. Grimes 	 * Zero length files can't be exec'd
174526f9a767SRodney W. Grimes 	 */
174626f9a767SRodney W. Grimes 	if (attr->va_size == 0)
174726f9a767SRodney W. Grimes 		return (ENOEXEC);
174826f9a767SRodney W. Grimes 
174926f9a767SRodney W. Grimes 	/*
175026f9a767SRodney W. Grimes 	 *  Check for execute permission to file based on current credentials.
175126f9a767SRodney W. Grimes 	 */
1752a854ed98SJohn Baldwin 	error = VOP_ACCESS(vp, VEXEC, td->td_ucred, td);
175326f9a767SRodney W. Grimes 	if (error)
175426f9a767SRodney W. Grimes 		return (error);
175526f9a767SRodney W. Grimes 
17566d5a0a8cSDavid Greenman 	/*
17576d5a0a8cSDavid Greenman 	 * Check number of open-for-writes on the file and deny execution
17586d5a0a8cSDavid Greenman 	 * if there are any.
175978022527SKonstantin Belousov 	 *
176078022527SKonstantin Belousov 	 * Add a text reference now so no one can write to the
176178022527SKonstantin Belousov 	 * executable while we're activating it.
176278022527SKonstantin Belousov 	 *
176378022527SKonstantin Belousov 	 * Remember if this was set before and unset it in case this is not
176478022527SKonstantin Belousov 	 * actually an executable image.
17656d5a0a8cSDavid Greenman 	 */
176678022527SKonstantin Belousov 	error = VOP_SET_TEXT(vp);
1767140dedb8SKonstantin Belousov 	if (error != 0)
1768140dedb8SKonstantin Belousov 		return (error);
176978022527SKonstantin Belousov 	imgp->textset = true;
17706d5a0a8cSDavid Greenman 
17716d5a0a8cSDavid Greenman 	/*
17726d5a0a8cSDavid Greenman 	 * Call filesystem specific open routine (which does nothing in the
17736d5a0a8cSDavid Greenman 	 * general case).
17746d5a0a8cSDavid Greenman 	 */
17759e223287SKonstantin Belousov 	error = VOP_OPEN(vp, FREAD, td->td_ucred, td, NULL);
17769a75ea23SKonstantin Belousov 	if (error == 0)
17779a75ea23SKonstantin Belousov 		imgp->opened = 1;
177826f9a767SRodney W. Grimes 	return (error);
1779df8bae1dSRodney W. Grimes }
1780aa855a59SPeter Wemm 
1781aa855a59SPeter Wemm /*
1782aa855a59SPeter Wemm  * Exec handler registration
1783aa855a59SPeter Wemm  */
1784aa855a59SPeter Wemm int
17853e85b721SEd Maste exec_register(const struct execsw *execsw_arg)
1786aa855a59SPeter Wemm {
1787aa855a59SPeter Wemm 	const struct execsw **es, **xs, **newexecsw;
1788d821d364SPedro F. Giffuni 	u_int count = 2;	/* New slot and trailing NULL */
1789aa855a59SPeter Wemm 
1790aa855a59SPeter Wemm 	if (execsw)
1791aa855a59SPeter Wemm 		for (es = execsw; *es; es++)
1792aa855a59SPeter Wemm 			count++;
1793a163d034SWarner Losh 	newexecsw = malloc(count * sizeof(*es), M_TEMP, M_WAITOK);
1794aa855a59SPeter Wemm 	xs = newexecsw;
1795aa855a59SPeter Wemm 	if (execsw)
1796aa855a59SPeter Wemm 		for (es = execsw; *es; es++)
1797aa855a59SPeter Wemm 			*xs++ = *es;
1798aa855a59SPeter Wemm 	*xs++ = execsw_arg;
1799aa855a59SPeter Wemm 	*xs = NULL;
1800aa855a59SPeter Wemm 	if (execsw)
1801aa855a59SPeter Wemm 		free(execsw, M_TEMP);
1802aa855a59SPeter Wemm 	execsw = newexecsw;
1803a7cddfedSJake Burkholder 	return (0);
1804aa855a59SPeter Wemm }
1805aa855a59SPeter Wemm 
1806aa855a59SPeter Wemm int
18073e85b721SEd Maste exec_unregister(const struct execsw *execsw_arg)
1808aa855a59SPeter Wemm {
1809aa855a59SPeter Wemm 	const struct execsw **es, **xs, **newexecsw;
1810aa855a59SPeter Wemm 	int count = 1;
1811aa855a59SPeter Wemm 
1812aa855a59SPeter Wemm 	if (execsw == NULL)
1813aa855a59SPeter Wemm 		panic("unregister with no handlers left?\n");
1814aa855a59SPeter Wemm 
1815aa855a59SPeter Wemm 	for (es = execsw; *es; es++) {
1816aa855a59SPeter Wemm 		if (*es == execsw_arg)
1817aa855a59SPeter Wemm 			break;
1818aa855a59SPeter Wemm 	}
1819aa855a59SPeter Wemm 	if (*es == NULL)
1820a7cddfedSJake Burkholder 		return (ENOENT);
1821aa855a59SPeter Wemm 	for (es = execsw; *es; es++)
1822aa855a59SPeter Wemm 		if (*es != execsw_arg)
1823aa855a59SPeter Wemm 			count++;
1824a163d034SWarner Losh 	newexecsw = malloc(count * sizeof(*es), M_TEMP, M_WAITOK);
1825aa855a59SPeter Wemm 	xs = newexecsw;
1826aa855a59SPeter Wemm 	for (es = execsw; *es; es++)
1827aa855a59SPeter Wemm 		if (*es != execsw_arg)
1828aa855a59SPeter Wemm 			*xs++ = *es;
1829aa855a59SPeter Wemm 	*xs = NULL;
1830aa855a59SPeter Wemm 	if (execsw)
1831aa855a59SPeter Wemm 		free(execsw, M_TEMP);
1832aa855a59SPeter Wemm 	execsw = newexecsw;
1833a7cddfedSJake Burkholder 	return (0);
1834aa855a59SPeter Wemm }
1835