xref: /freebsd/sys/compat/linux/linux_util.c (revision 25fb30bd9abc492359ad1f66901a06cb8cd08370)
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/lock.h>
42 #include <sys/malloc.h>
43 #include <sys/kernel.h>
44 #include <sys/linker_set.h>
45 #include <sys/mutex.h>
46 #include <sys/namei.h>
47 #include <sys/proc.h>
48 #include <sys/sdt.h>
49 #include <sys/syscallsubr.h>
50 #include <sys/sysctl.h>
51 #include <sys/systm.h>
52 #include <sys/vnode.h>
53 
54 #include <machine/stdarg.h>
55 
56 #include <compat/linux/linux_mib.h>
57 #include <compat/linux/linux_util.h>
58 
59 MALLOC_DEFINE(M_LINUX, "linux", "Linux mode structures");
60 MALLOC_DEFINE(M_EPOLL, "lepoll", "Linux events structures");
61 MALLOC_DEFINE(M_FUTEX, "futex", "Linux futexes");
62 MALLOC_DEFINE(M_FUTEX_WP, "futex wp", "Linux futex waiting proc");
63 
64 char linux_emul_path[MAXPATHLEN] = "/compat/linux";
65 
66 SYSCTL_STRING(_compat_linux, OID_AUTO, emul_path, CTLFLAG_RWTUN,
67     linux_emul_path, sizeof(linux_emul_path),
68     "Linux runtime environment path");
69 
70 /*
71  * Search an alternate path before passing pathname arguments on to
72  * system calls. Useful for keeping a separate 'emulation tree'.
73  *
74  * If cflag is set, we check if an attempt can be made to create the
75  * named file, i.e. we check if the directory it should be in exists.
76  */
77 int
78 linux_emul_convpath(struct thread *td, const char *path, enum uio_seg pathseg,
79     char **pbuf, int cflag, int dfd)
80 {
81 	int retval;
82 
83 	retval = kern_alternate_path(td, linux_emul_path, path, pathseg, pbuf,
84 	    cflag, dfd);
85 
86 	return (retval);
87 }
88 
89 void
90 linux_msg(const struct thread *td, const char *fmt, ...)
91 {
92 	va_list ap;
93 	struct proc *p;
94 
95 	if (linux_debug == 0)
96 		return;
97 
98 	p = td->td_proc;
99 	printf("linux: pid %d (%s): ", (int)p->p_pid, p->p_comm);
100 	va_start(ap, fmt);
101 	vprintf(fmt, ap);
102 	va_end(ap);
103 	printf("\n");
104 }
105 
106 struct device_element
107 {
108 	TAILQ_ENTRY(device_element) list;
109 	struct linux_device_handler entry;
110 };
111 
112 static TAILQ_HEAD(, device_element) devices =
113 	TAILQ_HEAD_INITIALIZER(devices);
114 
115 static struct linux_device_handler null_handler =
116 	{ "mem", "mem", "null", "null", 1, 3, 1};
117 
118 DATA_SET(linux_device_handler_set, null_handler);
119 
120 char *
121 linux_driver_get_name_dev(device_t dev)
122 {
123 	struct device_element *de;
124 	const char *device_name = device_get_name(dev);
125 
126 	if (device_name == NULL)
127 		return (NULL);
128 	TAILQ_FOREACH(de, &devices, list) {
129 		if (strcmp(device_name, de->entry.bsd_driver_name) == 0)
130 			return (de->entry.linux_driver_name);
131 	}
132 
133 	return (NULL);
134 }
135 
136 int
137 linux_driver_get_major_minor(const char *node, int *major, int *minor)
138 {
139 	struct device_element *de;
140 	unsigned long devno;
141 	size_t sz;
142 
143 	if (node == NULL || major == NULL || minor == NULL)
144 		return (1);
145 
146 	sz = sizeof("pts/") - 1;
147 	if (strncmp(node, "pts/", sz) == 0 && node[sz] != '\0') {
148 		/*
149 		 * Linux checks major and minors of the slave device
150 		 * to make sure it's a pty device, so let's make him
151 		 * believe it is.
152 		 */
153 		devno = strtoul(node + sz, NULL, 10);
154 		*major = 136 + (devno / 256);
155 		*minor = devno % 256;
156 		return (0);
157 	}
158 
159 	sz = sizeof("dri/card") - 1;
160 	if (strncmp(node, "dri/card", sz) == 0 && node[sz] != '\0') {
161 		devno = strtoul(node + sz, NULL, 10);
162 		*major = 226 + (devno / 256);
163 		*minor = devno % 256;
164 		return (0);
165 	}
166 	sz = sizeof("dri/controlD") - 1;
167 	if (strncmp(node, "dri/controlD", sz) == 0 && node[sz] != '\0') {
168 		devno = strtoul(node + sz, NULL, 10);
169 		*major = 226 + (devno / 256);
170 		*minor = devno % 256;
171 		return (0);
172 	}
173 	sz = sizeof("dri/renderD") - 1;
174 	if (strncmp(node, "dri/renderD", sz) == 0 && node[sz] != '\0') {
175 		devno = strtoul(node + sz, NULL, 10);
176 		*major = 226 + (devno / 256);
177 		*minor = devno % 256;
178 		return (0);
179 	}
180 	sz = sizeof("drm/") - 1;
181 	if (strncmp(node, "drm/", sz) == 0 && node[sz] != '\0') {
182 		devno = strtoul(node + sz, NULL, 10);
183 		*major = 226 + (devno / 256);
184 		*minor = devno % 256;
185 		return (0);
186 	}
187 
188 	TAILQ_FOREACH(de, &devices, list) {
189 		if (strcmp(node, de->entry.bsd_device_name) == 0) {
190 			*major = de->entry.linux_major;
191 			*minor = de->entry.linux_minor;
192 			return (0);
193 		}
194 	}
195 
196 	return (1);
197 }
198 
199 int
200 linux_vn_get_major_minor(const struct vnode *vp, int *major, int *minor)
201 {
202 	int error;
203 
204 	if (vp->v_type != VCHR)
205 		return (ENOTBLK);
206 	dev_lock();
207 	if (vp->v_rdev == NULL) {
208 		dev_unlock();
209 		return (ENXIO);
210 	}
211 	error = linux_driver_get_major_minor(devtoname(vp->v_rdev),
212 	    major, minor);
213 	dev_unlock();
214 	return (error);
215 }
216 
217 char *
218 linux_get_char_devices()
219 {
220 	struct device_element *de;
221 	char *temp, *string, *last;
222 	char formated[256];
223 	int current_size = 0, string_size = 1024;
224 
225 	string = malloc(string_size, M_LINUX, M_WAITOK);
226 	string[0] = '\000';
227 	last = "";
228 	TAILQ_FOREACH(de, &devices, list) {
229 		if (!de->entry.linux_char_device)
230 			continue;
231 		temp = string;
232 		if (strcmp(last, de->entry.bsd_driver_name) != 0) {
233 			last = de->entry.bsd_driver_name;
234 
235 			snprintf(formated, sizeof(formated), "%3d %s\n",
236 				 de->entry.linux_major,
237 				 de->entry.linux_device_name);
238 			if (strlen(formated) + current_size
239 			    >= string_size) {
240 				string_size *= 2;
241 				string = malloc(string_size,
242 				    M_LINUX, M_WAITOK);
243 				bcopy(temp, string, current_size);
244 				free(temp, M_LINUX);
245 			}
246 			strcat(string, formated);
247 			current_size = strlen(string);
248 		}
249 	}
250 
251 	return (string);
252 }
253 
254 void
255 linux_free_get_char_devices(char *string)
256 {
257 
258 	free(string, M_LINUX);
259 }
260 
261 static int linux_major_starting = 200;
262 
263 int
264 linux_device_register_handler(struct linux_device_handler *d)
265 {
266 	struct device_element *de;
267 
268 	if (d == NULL)
269 		return (EINVAL);
270 
271 	de = malloc(sizeof(*de), M_LINUX, M_WAITOK);
272 	if (d->linux_major < 0) {
273 		d->linux_major = linux_major_starting++;
274 	}
275 	bcopy(d, &de->entry, sizeof(*d));
276 
277 	/* Add the element to the list, sorted on span. */
278 	TAILQ_INSERT_TAIL(&devices, de, list);
279 
280 	return (0);
281 }
282 
283 int
284 linux_device_unregister_handler(struct linux_device_handler *d)
285 {
286 	struct device_element *de;
287 
288 	if (d == NULL)
289 		return (EINVAL);
290 
291 	TAILQ_FOREACH(de, &devices, list) {
292 		if (bcmp(d, &de->entry, sizeof(*d)) == 0) {
293 			TAILQ_REMOVE(&devices, de, list);
294 			free(de, M_LINUX);
295 
296 			return (0);
297 		}
298 	}
299 
300 	return (EINVAL);
301 }
302