xref: /freebsd/sys/compat/linux/linux_util.c (revision 52f72944b8f5abb2386eae924357dee8aea17d5b)
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 "opt_compat.h"
38 
39 #include <sys/param.h>
40 #include <sys/bus.h>
41 #include <sys/fcntl.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/systm.h>
52 #include <sys/vnode.h>
53 
54 #include <machine/stdarg.h>
55 
56 #include <compat/linux/linux_util.h>
57 
58 MALLOC_DEFINE(M_LINUX, "linux", "Linux mode structures");
59 MALLOC_DEFINE(M_EPOLL, "lepoll", "Linux events structures");
60 MALLOC_DEFINE(M_FUTEX, "futex", "Linux futexes");
61 MALLOC_DEFINE(M_FUTEX_WP, "futex wp", "Linux futex waiting proc");
62 
63 const char      linux_emul_path[] = "/compat/linux";
64 
65 /*
66  * Search an alternate path before passing pathname arguments on to
67  * system calls. Useful for keeping a separate 'emulation tree'.
68  *
69  * If cflag is set, we check if an attempt can be made to create the
70  * named file, i.e. we check if the directory it should be in exists.
71  */
72 int
73 linux_emul_convpath(struct thread *td, const char *path, enum uio_seg pathseg,
74     char **pbuf, int cflag, int dfd)
75 {
76 	int retval;
77 
78 	retval = kern_alternate_path(td, linux_emul_path, path, pathseg, pbuf,
79 	    cflag, dfd);
80 
81 	return (retval);
82 }
83 
84 void
85 linux_msg(const struct thread *td, const char *fmt, ...)
86 {
87 	va_list ap;
88 	struct proc *p;
89 
90 	p = td->td_proc;
91 	printf("linux: pid %d (%s): ", (int)p->p_pid, p->p_comm);
92 	va_start(ap, fmt);
93 	vprintf(fmt, ap);
94 	va_end(ap);
95 	printf("\n");
96 }
97 
98 struct device_element
99 {
100 	TAILQ_ENTRY(device_element) list;
101 	struct linux_device_handler entry;
102 };
103 
104 static TAILQ_HEAD(, device_element) devices =
105 	TAILQ_HEAD_INITIALIZER(devices);
106 
107 static struct linux_device_handler null_handler =
108 	{ "mem", "mem", "null", "null", 1, 3, 1};
109 
110 DATA_SET(linux_device_handler_set, null_handler);
111 
112 char *
113 linux_driver_get_name_dev(device_t dev)
114 {
115 	struct device_element *de;
116 	const char *device_name = device_get_name(dev);
117 
118 	if (device_name == NULL)
119 		return (NULL);
120 	TAILQ_FOREACH(de, &devices, list) {
121 		if (strcmp(device_name, de->entry.bsd_driver_name) == 0)
122 			return (de->entry.linux_driver_name);
123 	}
124 
125 	return (NULL);
126 }
127 
128 int
129 linux_driver_get_major_minor(const char *node, int *major, int *minor)
130 {
131 	struct device_element *de;
132 	unsigned long devno;
133 	size_t sz;
134 
135 	if (node == NULL || major == NULL || minor == NULL)
136 		return (1);
137 
138 	sz = sizeof("pts/") - 1;
139 	if (strncmp(node, "pts/", sz) == 0 && node[sz] != '\0') {
140 		/*
141 		 * Linux checks major and minors of the slave device
142 		 * to make sure it's a pty device, so let's make him
143 		 * believe it is.
144 		 */
145 		devno = strtoul(node + sz, NULL, 10);
146 		*major = 136 + (devno / 256);
147 		*minor = devno % 256;
148 		return (0);
149 	}
150 
151 	sz = sizeof("dri/card") - 1;
152 	if (strncmp(node, "dri/card", sz) == 0 && node[sz] != '\0') {
153 		devno = strtoul(node + sz, NULL, 10);
154 		*major = 226 + (devno / 256);
155 		*minor = devno % 256;
156 		return (0);
157 	}
158 	sz = sizeof("dri/controlD") - 1;
159 	if (strncmp(node, "dri/controlD", sz) == 0 && node[sz] != '\0') {
160 		devno = strtoul(node + sz, NULL, 10);
161 		*major = 226 + (devno / 256);
162 		*minor = devno % 256;
163 		return (0);
164 	}
165 	sz = sizeof("dri/renderD") - 1;
166 	if (strncmp(node, "dri/renderD", sz) == 0 && node[sz] != '\0') {
167 		devno = strtoul(node + sz, NULL, 10);
168 		*major = 226 + (devno / 256);
169 		*minor = devno % 256;
170 		return (0);
171 	}
172 	sz = sizeof("drm/") - 1;
173 	if (strncmp(node, "drm/", sz) == 0 && node[sz] != '\0') {
174 		devno = strtoul(node + sz, NULL, 10);
175 		*major = 226 + (devno / 256);
176 		*minor = devno % 256;
177 		return (0);
178 	}
179 
180 	TAILQ_FOREACH(de, &devices, list) {
181 		if (strcmp(node, de->entry.bsd_device_name) == 0) {
182 			*major = de->entry.linux_major;
183 			*minor = de->entry.linux_minor;
184 			return (0);
185 		}
186 	}
187 
188 	return (1);
189 }
190 
191 char *
192 linux_get_char_devices()
193 {
194 	struct device_element *de;
195 	char *temp, *string, *last;
196 	char formated[256];
197 	int current_size = 0, string_size = 1024;
198 
199 	string = malloc(string_size, M_LINUX, M_WAITOK);
200 	string[0] = '\000';
201 	last = "";
202 	TAILQ_FOREACH(de, &devices, list) {
203 		if (!de->entry.linux_char_device)
204 			continue;
205 		temp = string;
206 		if (strcmp(last, de->entry.bsd_driver_name) != 0) {
207 			last = de->entry.bsd_driver_name;
208 
209 			snprintf(formated, sizeof(formated), "%3d %s\n",
210 				 de->entry.linux_major,
211 				 de->entry.linux_device_name);
212 			if (strlen(formated) + current_size
213 			    >= string_size) {
214 				string_size *= 2;
215 				string = malloc(string_size,
216 				    M_LINUX, M_WAITOK);
217 				bcopy(temp, string, current_size);
218 				free(temp, M_LINUX);
219 			}
220 			strcat(string, formated);
221 			current_size = strlen(string);
222 		}
223 	}
224 
225 	return (string);
226 }
227 
228 void
229 linux_free_get_char_devices(char *string)
230 {
231 
232 	free(string, M_LINUX);
233 }
234 
235 static int linux_major_starting = 200;
236 
237 int
238 linux_device_register_handler(struct linux_device_handler *d)
239 {
240 	struct device_element *de;
241 
242 	if (d == NULL)
243 		return (EINVAL);
244 
245 	de = malloc(sizeof(*de), M_LINUX, M_WAITOK);
246 	if (d->linux_major < 0) {
247 		d->linux_major = linux_major_starting++;
248 	}
249 	bcopy(d, &de->entry, sizeof(*d));
250 
251 	/* Add the element to the list, sorted on span. */
252 	TAILQ_INSERT_TAIL(&devices, de, list);
253 
254 	return (0);
255 }
256 
257 int
258 linux_device_unregister_handler(struct linux_device_handler *d)
259 {
260 	struct device_element *de;
261 
262 	if (d == NULL)
263 		return (EINVAL);
264 
265 	TAILQ_FOREACH(de, &devices, list) {
266 		if (bcmp(d, &de->entry, sizeof(*d)) == 0) {
267 			TAILQ_REMOVE(&devices, de, list);
268 			free(de, M_LINUX);
269 
270 			return (0);
271 		}
272 	}
273 
274 	return (EINVAL);
275 }
276