xref: /freebsd/sys/compat/linux/linux_util.c (revision 36d6566e5985030fd2f1100bd9c1387bbe0bd290)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1994 Christos Zoulas
5  * Copyright (c) 1995 Frank van der Linden
6  * Copyright (c) 1995 Scott Bartram
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. The name of the author may not be used to endorse or promote products
18  *    derived from this software without specific prior written permission
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
21  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
22  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
23  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
24  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
25  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
26  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
27  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
28  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
29  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30  *
31  *	from: svr4_util.c,v 1.5 1995/01/22 23:44:50 christos Exp
32  */
33 
34 #include <sys/cdefs.h>
35 __FBSDID("$FreeBSD$");
36 
37 #include <sys/param.h>
38 #include <sys/bus.h>
39 #include <sys/conf.h>
40 #include <sys/fcntl.h>
41 #include <sys/jail.h>
42 #include <sys/lock.h>
43 #include <sys/malloc.h>
44 #include <sys/kernel.h>
45 #include <sys/linker_set.h>
46 #include <sys/mutex.h>
47 #include <sys/namei.h>
48 #include <sys/proc.h>
49 #include <sys/sdt.h>
50 #include <sys/syscallsubr.h>
51 #include <sys/sysctl.h>
52 #include <sys/systm.h>
53 #include <sys/vnode.h>
54 
55 #include <machine/stdarg.h>
56 
57 #include <compat/linux/linux_mib.h>
58 #include <compat/linux/linux_util.h>
59 
60 MALLOC_DEFINE(M_LINUX, "linux", "Linux mode structures");
61 MALLOC_DEFINE(M_EPOLL, "lepoll", "Linux events structures");
62 MALLOC_DEFINE(M_FUTEX, "futex", "Linux futexes");
63 MALLOC_DEFINE(M_FUTEX_WP, "futex wp", "Linux futex waiting proc");
64 
65 char linux_emul_path[MAXPATHLEN] = "/compat/linux";
66 
67 SYSCTL_STRING(_compat_linux, OID_AUTO, emul_path, CTLFLAG_RWTUN,
68     linux_emul_path, sizeof(linux_emul_path),
69     "Linux runtime environment path");
70 
71 /*
72  * Search an alternate path before passing pathname arguments on to
73  * system calls. Useful for keeping a separate 'emulation tree'.
74  *
75  * If cflag is set, we check if an attempt can be made to create the
76  * named file, i.e. we check if the directory it should be in exists.
77  */
78 int
79 linux_emul_convpath(struct thread *td, const char *path, enum uio_seg pathseg,
80     char **pbuf, int cflag, int dfd)
81 {
82 	int retval;
83 
84 	retval = kern_alternate_path(td, linux_emul_path, path, pathseg, pbuf,
85 	    cflag, dfd);
86 
87 	return (retval);
88 }
89 
90 void
91 linux_msg(const struct thread *td, const char *fmt, ...)
92 {
93 	va_list ap;
94 	struct proc *p;
95 
96 	if (linux_debug == 0)
97 		return;
98 
99 	p = td->td_proc;
100 	printf("linux: jid %d pid %d (%s): ", p->p_ucred->cr_prison->pr_id,
101 	    (int)p->p_pid, p->p_comm);
102 	va_start(ap, fmt);
103 	vprintf(fmt, ap);
104 	va_end(ap);
105 	printf("\n");
106 }
107 
108 struct device_element
109 {
110 	TAILQ_ENTRY(device_element) list;
111 	struct linux_device_handler entry;
112 };
113 
114 static TAILQ_HEAD(, device_element) devices =
115 	TAILQ_HEAD_INITIALIZER(devices);
116 
117 static struct linux_device_handler null_handler =
118 	{ "mem", "mem", "null", "null", 1, 3, 1};
119 
120 DATA_SET(linux_device_handler_set, null_handler);
121 
122 char *
123 linux_driver_get_name_dev(device_t dev)
124 {
125 	struct device_element *de;
126 	const char *device_name = device_get_name(dev);
127 
128 	if (device_name == NULL)
129 		return (NULL);
130 	TAILQ_FOREACH(de, &devices, list) {
131 		if (strcmp(device_name, de->entry.bsd_driver_name) == 0)
132 			return (de->entry.linux_driver_name);
133 	}
134 
135 	return (NULL);
136 }
137 
138 int
139 linux_driver_get_major_minor(const char *node, int *major, int *minor)
140 {
141 	struct device_element *de;
142 	unsigned long devno;
143 	size_t sz;
144 
145 	if (node == NULL || major == NULL || minor == NULL)
146 		return (1);
147 
148 	sz = sizeof("pts/") - 1;
149 	if (strncmp(node, "pts/", sz) == 0 && node[sz] != '\0') {
150 		/*
151 		 * Linux checks major and minors of the slave device
152 		 * to make sure it's a pty device, so let's make him
153 		 * believe it is.
154 		 */
155 		devno = strtoul(node + sz, NULL, 10);
156 		*major = 136 + (devno / 256);
157 		*minor = devno % 256;
158 		return (0);
159 	}
160 
161 	sz = sizeof("dri/card") - 1;
162 	if (strncmp(node, "dri/card", sz) == 0 && node[sz] != '\0') {
163 		devno = strtoul(node + sz, NULL, 10);
164 		*major = 226 + (devno / 256);
165 		*minor = devno % 256;
166 		return (0);
167 	}
168 	sz = sizeof("dri/controlD") - 1;
169 	if (strncmp(node, "dri/controlD", sz) == 0 && node[sz] != '\0') {
170 		devno = strtoul(node + sz, NULL, 10);
171 		*major = 226 + (devno / 256);
172 		*minor = devno % 256;
173 		return (0);
174 	}
175 	sz = sizeof("dri/renderD") - 1;
176 	if (strncmp(node, "dri/renderD", sz) == 0 && node[sz] != '\0') {
177 		devno = strtoul(node + sz, NULL, 10);
178 		*major = 226 + (devno / 256);
179 		*minor = devno % 256;
180 		return (0);
181 	}
182 	sz = sizeof("drm/") - 1;
183 	if (strncmp(node, "drm/", sz) == 0 && node[sz] != '\0') {
184 		devno = strtoul(node + sz, NULL, 10);
185 		*major = 226 + (devno / 256);
186 		*minor = devno % 256;
187 		return (0);
188 	}
189 
190 	TAILQ_FOREACH(de, &devices, list) {
191 		if (strcmp(node, de->entry.bsd_device_name) == 0) {
192 			*major = de->entry.linux_major;
193 			*minor = de->entry.linux_minor;
194 			return (0);
195 		}
196 	}
197 
198 	return (1);
199 }
200 
201 int
202 linux_vn_get_major_minor(const struct vnode *vp, int *major, int *minor)
203 {
204 	int error;
205 
206 	if (vp->v_type != VCHR)
207 		return (ENOTBLK);
208 	dev_lock();
209 	if (vp->v_rdev == NULL) {
210 		dev_unlock();
211 		return (ENXIO);
212 	}
213 	error = linux_driver_get_major_minor(devtoname(vp->v_rdev),
214 	    major, minor);
215 	dev_unlock();
216 	return (error);
217 }
218 
219 char *
220 linux_get_char_devices()
221 {
222 	struct device_element *de;
223 	char *temp, *string, *last;
224 	char formated[256];
225 	int current_size = 0, string_size = 1024;
226 
227 	string = malloc(string_size, M_LINUX, M_WAITOK);
228 	string[0] = '\000';
229 	last = "";
230 	TAILQ_FOREACH(de, &devices, list) {
231 		if (!de->entry.linux_char_device)
232 			continue;
233 		temp = string;
234 		if (strcmp(last, de->entry.bsd_driver_name) != 0) {
235 			last = de->entry.bsd_driver_name;
236 
237 			snprintf(formated, sizeof(formated), "%3d %s\n",
238 				 de->entry.linux_major,
239 				 de->entry.linux_device_name);
240 			if (strlen(formated) + current_size
241 			    >= string_size) {
242 				string_size *= 2;
243 				string = malloc(string_size,
244 				    M_LINUX, M_WAITOK);
245 				bcopy(temp, string, current_size);
246 				free(temp, M_LINUX);
247 			}
248 			strcat(string, formated);
249 			current_size = strlen(string);
250 		}
251 	}
252 
253 	return (string);
254 }
255 
256 void
257 linux_free_get_char_devices(char *string)
258 {
259 
260 	free(string, M_LINUX);
261 }
262 
263 static int linux_major_starting = 200;
264 
265 int
266 linux_device_register_handler(struct linux_device_handler *d)
267 {
268 	struct device_element *de;
269 
270 	if (d == NULL)
271 		return (EINVAL);
272 
273 	de = malloc(sizeof(*de), M_LINUX, M_WAITOK);
274 	if (d->linux_major < 0) {
275 		d->linux_major = linux_major_starting++;
276 	}
277 	bcopy(d, &de->entry, sizeof(*d));
278 
279 	/* Add the element to the list, sorted on span. */
280 	TAILQ_INSERT_TAIL(&devices, de, list);
281 
282 	return (0);
283 }
284 
285 int
286 linux_device_unregister_handler(struct linux_device_handler *d)
287 {
288 	struct device_element *de;
289 
290 	if (d == NULL)
291 		return (EINVAL);
292 
293 	TAILQ_FOREACH(de, &devices, list) {
294 		if (bcmp(d, &de->entry, sizeof(*d)) == 0) {
295 			TAILQ_REMOVE(&devices, de, list);
296 			free(de, M_LINUX);
297 
298 			return (0);
299 		}
300 	}
301 
302 	return (EINVAL);
303 }
304