xref: /netbsd-src/sys/compat/netbsd32/netbsd32_execve.c (revision 181254a7b1bdde6873432bffef2d2decc4b5c22f)
1 /*	$NetBSD: netbsd32_execve.c,v 1.42 2020/04/19 20:31:59 thorpej Exp $	*/
2 
3 /*
4  * Copyright (c) 1998, 2001 Matthew R. Green
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
22  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
30 
31 __KERNEL_RCSID(0, "$NetBSD: netbsd32_execve.c,v 1.42 2020/04/19 20:31:59 thorpej Exp $");
32 
33 #include <sys/param.h>
34 #include <sys/systm.h>
35 #include <sys/atomic.h>
36 #include <sys/mount.h>
37 #include <sys/namei.h>
38 #include <sys/stat.h>
39 #include <sys/spawn.h>
40 #include <sys/uidinfo.h>
41 #include <sys/vnode.h>
42 #include <sys/file.h>
43 #include <sys/filedesc.h>
44 #include <sys/syscallargs.h>
45 #include <sys/proc.h>
46 #include <sys/exec.h>
47 
48 #include <compat/netbsd32/netbsd32.h>
49 #include <compat/netbsd32/netbsd32_syscall.h>
50 #include <compat/netbsd32/netbsd32_syscallargs.h>
51 
52 static int
53 netbsd32_execve_fetch_element(char * const *array, size_t index, char **value)
54 {
55 	int error;
56 	netbsd32_charp const *a32 = (void const *)array;
57 	netbsd32_charp e;
58 
59 	error = copyin(a32 + index, &e, sizeof(e));
60 	if (error)
61 		return error;
62 	*value = (char *)NETBSD32PTR64(e);
63 	return 0;
64 }
65 
66 int
67 netbsd32_execve(struct lwp *l, const struct netbsd32_execve_args *uap, register_t *retval)
68 {
69 	/* {
70 		syscallarg(const netbsd32_charp) path;
71 		syscallarg(netbsd32_charpp) argp;
72 		syscallarg(netbsd32_charpp) envp;
73 	} */
74 
75 	return execve1(l, true, SCARG_P32(uap, path), -1, SCARG_P32(uap, argp),
76 	    SCARG_P32(uap, envp), netbsd32_execve_fetch_element);
77 }
78 
79 int
80 netbsd32_fexecve(struct lwp *l, const struct netbsd32_fexecve_args *uap,
81 		 register_t *retval)
82 {
83 	/* {
84 		syscallarg(int) fd;
85 		syscallarg(netbsd32_charpp) argp;
86 		syscallarg(netbsd32_charpp) envp;
87 	} */
88 
89 	return execve1(l, false, NULL, SCARG(uap, fd), SCARG_P32(uap, argp),
90 	    SCARG_P32(uap, envp), netbsd32_execve_fetch_element);
91 }
92 
93 static int
94 netbsd32_posix_spawn_fa_alloc(struct posix_spawn_file_actions **fap,
95     const struct netbsd32_posix_spawn_file_actions *ufa, rlim_t lim)
96 {
97 	struct posix_spawn_file_actions *fa;
98 	struct netbsd32_posix_spawn_file_actions fa32;
99 	struct netbsd32_posix_spawn_file_actions_entry *fae32 = NULL, *f32 = NULL;
100 	struct posix_spawn_file_actions_entry *fae;
101 	char *pbuf = NULL;
102 	int error;
103 	size_t fal, fal32, slen, i = 0;
104 
105 	error = copyin(ufa, &fa32, sizeof(fa32));
106 	if (error)
107 		return error;
108 
109 	if (fa32.len == 0)
110 		return 0;
111 
112 	fa = kmem_alloc(sizeof(*fa), KM_SLEEP);
113 	fa->len = fa->size = fa32.len;
114 
115 	if (fa->len > lim) {
116 		kmem_free(fa, sizeof(*fa));
117 		return EINVAL;
118 	}
119 
120 	fal = fa->len * sizeof(*fae);
121 	fal32 = fa->len * sizeof(*fae32);
122 
123 	fa->fae = kmem_alloc(fal, KM_SLEEP);
124 	fae32 = kmem_alloc(fal32, KM_SLEEP);
125 	error = copyin(NETBSD32PTR64(fa32.fae), fae32, fal32);
126 	if (error)
127 		goto out;
128 
129 	pbuf = PNBUF_GET();
130 	for (; i < fa->len; i++) {
131 		fae = &fa->fae[i];
132 		f32 = &fae32[i];
133 		fae->fae_action = f32->fae_action;
134 		fae->fae_fildes = f32->fae_fildes;
135 		if (fae->fae_action == FAE_DUP2)
136 			fae->fae_data.dup2.newfildes =
137 			    f32->fae_data.dup2.newfildes;
138 		if (fae->fae_action != FAE_OPEN)
139 			continue;
140 		error = copyinstr(NETBSD32PTR64(f32->fae_path), pbuf,
141 		    MAXPATHLEN, &slen);
142 		if (error)
143 			goto out;
144 		fae->fae_path = kmem_alloc(slen, KM_SLEEP);
145 		memcpy(fae->fae_path, pbuf, slen);
146 		fae->fae_oflag = f32->fae_oflag;
147 		fae->fae_mode = f32->fae_mode;
148 	}
149 	PNBUF_PUT(pbuf);
150 	if (fae32)
151 		kmem_free(fae32, fal32);
152 	*fap = fa;
153 	return 0;
154 
155 out:
156 	if (fae32)
157 		kmem_free(fae32, fal32);
158 	if (pbuf)
159 		PNBUF_PUT(pbuf);
160 	posix_spawn_fa_free(fa, i);
161 	return error;
162 }
163 
164 int
165 netbsd32_posix_spawn(struct lwp *l,
166 	const struct netbsd32_posix_spawn_args *uap, register_t *retval)
167 {
168 	/* {
169 	syscallarg(netbsd32_pid_tp) pid;
170 	syscallarg(const netbsd32_charp) path;
171 	syscallarg(const netbsd32_posix_spawn_file_actionsp) file_actions;
172 	syscallarg(const netbsd32_posix_spawnattrp) attrp;
173 	syscallarg(netbsd32_charpp) argv;
174 	syscallarg(netbsd32_charpp) envp;
175 	} */
176 
177 	int error;
178 	struct posix_spawn_file_actions *fa = NULL;
179 	struct posix_spawnattr *sa = NULL;
180 	pid_t pid;
181 	bool child_ok = false;
182 	rlim_t max_fileactions;
183 	proc_t *p = l->l_proc;
184 
185 	/* check_posix_spawn() increments nprocs for us. */
186 	error = check_posix_spawn(l);
187 	if (error) {
188 		*retval = error;
189 		return 0;
190 	}
191 
192 	/* copy in file_actions struct */
193 	if (SCARG_P32(uap, file_actions) != NULL) {
194 		max_fileactions = 2 * uimin(p->p_rlimit[RLIMIT_NOFILE].rlim_cur,
195 		    maxfiles);
196 		error = netbsd32_posix_spawn_fa_alloc(&fa,
197 		    SCARG_P32(uap, file_actions), max_fileactions);
198 		if (error)
199 			goto error_exit;
200 	}
201 
202 	/* copyin posix_spawnattr struct */
203 	if (SCARG_P32(uap, attrp) != NULL) {
204 		sa = kmem_alloc(sizeof(*sa), KM_SLEEP);
205 		error = copyin(SCARG_P32(uap, attrp), sa, sizeof(*sa));
206 		if (error)
207 			goto error_exit;
208 	}
209 
210 	/*
211 	 * Do the spawn
212 	 */
213 	error = do_posix_spawn(l, &pid, &child_ok, SCARG_P32(uap, path), fa,
214 	    sa, SCARG_P32(uap, argv), SCARG_P32(uap, envp),
215 	    netbsd32_execve_fetch_element);
216 	if (error)
217 		goto error_exit;
218 
219 	if (error == 0 && SCARG_P32(uap, pid) != NULL)
220 		error = copyout(&pid, SCARG_P32(uap, pid), sizeof(pid));
221 
222 	*retval = error;
223 	return 0;
224 
225  error_exit:
226  	if (!child_ok) {
227 		(void)chgproccnt(kauth_cred_getuid(l->l_cred), -1);
228 		atomic_dec_uint(&nprocs);
229 
230 		if (sa)
231 			kmem_free(sa, sizeof(*sa));
232 		if (fa)
233 			posix_spawn_fa_free(fa, fa->len);
234 	}
235 
236 	*retval = error;
237 	return 0;
238 }
239