xref: /freebsd/sys/compat/linux/linux_util.c (revision 86c9d9918f1db7cdd968b60f8902466887bcd9e9)
1 /*-
2  * Copyright (c) 1994 Christos Zoulas
3  * Copyright (c) 1995 Frank van der Linden
4  * Copyright (c) 1995 Scott Bartram
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  * 3. The name of the author may not be used to endorse or promote products
16  *    derived from this software without specific prior written permission
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28  *
29  *	from: svr4_util.c,v 1.5 1995/01/22 23:44:50 christos Exp
30  */
31 
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD$");
34 
35 #include "opt_compat.h"
36 
37 #include <sys/param.h>
38 #include <sys/bus.h>
39 #include <sys/fcntl.h>
40 #include <sys/lock.h>
41 #include <sys/malloc.h>
42 #include <sys/kernel.h>
43 #include <sys/linker_set.h>
44 #include <sys/mutex.h>
45 #include <sys/namei.h>
46 #include <sys/proc.h>
47 #include <sys/sdt.h>
48 #include <sys/syscallsubr.h>
49 #include <sys/systm.h>
50 #include <sys/vnode.h>
51 
52 #include <machine/stdarg.h>
53 
54 #include <compat/linux/linux_util.h>
55 
56 MALLOC_DEFINE(M_LINUX, "linux", "Linux mode structures");
57 MALLOC_DEFINE(M_EPOLL, "lepoll", "Linux events structures");
58 MALLOC_DEFINE(M_FUTEX, "futex", "Linux futexes");
59 MALLOC_DEFINE(M_FUTEX_WP, "futex wp", "Linux futex waiting proc");
60 
61 const char      linux_emul_path[] = "/compat/linux";
62 
63 /*
64  * Search an alternate path before passing pathname arguments on to
65  * system calls. Useful for keeping a separate 'emulation tree'.
66  *
67  * If cflag is set, we check if an attempt can be made to create the
68  * named file, i.e. we check if the directory it should be in exists.
69  */
70 int
71 linux_emul_convpath(struct thread *td, const char *path, enum uio_seg pathseg,
72     char **pbuf, int cflag, int dfd)
73 {
74 	int retval;
75 
76 	retval = kern_alternate_path(td, linux_emul_path, path, pathseg, pbuf,
77 	    cflag, dfd);
78 
79 	return (retval);
80 }
81 
82 void
83 linux_msg(const struct thread *td, const char *fmt, ...)
84 {
85 	va_list ap;
86 	struct proc *p;
87 
88 	p = td->td_proc;
89 	printf("linux: pid %d (%s): ", (int)p->p_pid, p->p_comm);
90 	va_start(ap, fmt);
91 	vprintf(fmt, ap);
92 	va_end(ap);
93 	printf("\n");
94 }
95 
96 struct device_element
97 {
98 	TAILQ_ENTRY(device_element) list;
99 	struct linux_device_handler entry;
100 };
101 
102 static TAILQ_HEAD(, device_element) devices =
103 	TAILQ_HEAD_INITIALIZER(devices);
104 
105 static struct linux_device_handler null_handler =
106 	{ "mem", "mem", "null", "null", 1, 3, 1};
107 
108 DATA_SET(linux_device_handler_set, null_handler);
109 
110 char *
111 linux_driver_get_name_dev(device_t dev)
112 {
113 	struct device_element *de;
114 	const char *device_name = device_get_name(dev);
115 
116 	if (device_name == NULL)
117 		return NULL;
118 	TAILQ_FOREACH(de, &devices, list) {
119 		if (strcmp(device_name, de->entry.bsd_driver_name) == 0)
120 			return (de->entry.linux_driver_name);
121 	}
122 
123 	return (NULL);
124 }
125 
126 int
127 linux_driver_get_major_minor(const char *node, int *major, int *minor)
128 {
129 	struct device_element *de;
130 
131 	if (node == NULL || major == NULL || minor == NULL)
132 		return 1;
133 
134 	if (strlen(node) > strlen("pts/") &&
135 	    strncmp(node, "pts/", strlen("pts/")) == 0) {
136 		unsigned long devno;
137 
138 		/*
139 		 * Linux checks major and minors of the slave device
140 		 * to make sure it's a pty device, so let's make him
141 		 * believe it is.
142 		 */
143 		devno = strtoul(node + strlen("pts/"), NULL, 10);
144 		*major = 136 + (devno / 256);
145 		*minor = devno % 256;
146 
147 		return (0);
148 	}
149 
150 	TAILQ_FOREACH(de, &devices, list) {
151 		if (strcmp(node, de->entry.bsd_device_name) == 0) {
152 			*major = de->entry.linux_major;
153 			*minor = de->entry.linux_minor;
154 			return (0);
155 		}
156 	}
157 
158 	return (1);
159 }
160 
161 char *
162 linux_get_char_devices()
163 {
164 	struct device_element *de;
165 	char *temp, *string, *last;
166 	char formated[256];
167 	int current_size = 0, string_size = 1024;
168 
169 	string = malloc(string_size, M_LINUX, M_WAITOK);
170 	string[0] = '\000';
171 	last = "";
172 	TAILQ_FOREACH(de, &devices, list) {
173 		if (!de->entry.linux_char_device)
174 			continue;
175 		temp = string;
176 		if (strcmp(last, de->entry.bsd_driver_name) != 0) {
177 			last = de->entry.bsd_driver_name;
178 
179 			snprintf(formated, sizeof(formated), "%3d %s\n",
180 				 de->entry.linux_major,
181 				 de->entry.linux_device_name);
182 			if (strlen(formated) + current_size
183 			    >= string_size) {
184 				string_size *= 2;
185 				string = malloc(string_size,
186 				    M_LINUX, M_WAITOK);
187 				bcopy(temp, string, current_size);
188 				free(temp, M_LINUX);
189 			}
190 			strcat(string, formated);
191 			current_size = strlen(string);
192 		}
193 	}
194 
195 	return (string);
196 }
197 
198 void
199 linux_free_get_char_devices(char *string)
200 {
201 
202 	free(string, M_LINUX);
203 }
204 
205 static int linux_major_starting = 200;
206 
207 int
208 linux_device_register_handler(struct linux_device_handler *d)
209 {
210 	struct device_element *de;
211 
212 	if (d == NULL)
213 		return (EINVAL);
214 
215 	de = malloc(sizeof(*de), M_LINUX, M_WAITOK);
216 	if (d->linux_major < 0) {
217 		d->linux_major = linux_major_starting++;
218 	}
219 	bcopy(d, &de->entry, sizeof(*d));
220 
221 	/* Add the element to the list, sorted on span. */
222 	TAILQ_INSERT_TAIL(&devices, de, list);
223 
224 	return (0);
225 }
226 
227 int
228 linux_device_unregister_handler(struct linux_device_handler *d)
229 {
230 	struct device_element *de;
231 
232 	if (d == NULL)
233 		return (EINVAL);
234 
235 	TAILQ_FOREACH(de, &devices, list) {
236 		if (bcmp(d, &de->entry, sizeof(*d)) == 0) {
237 			TAILQ_REMOVE(&devices, de, list);
238 			free(de, M_LINUX);
239 
240 			return (0);
241 		}
242 	}
243 
244 	return (EINVAL);
245 }
246