xref: /freebsd/sys/compat/linux/linux_util.c (revision d4ae33f0721c1b170fe37d97e395228ffcfb3f80)
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 #ifdef COMPAT_LINUX32
56 #include <machine/../linux32/linux.h>
57 #else
58 #include <machine/../linux/linux.h>
59 #endif
60 
61 #include <compat/linux/linux_dtrace.h>
62 
63 const char      linux_emul_path[] = "/compat/linux";
64 
65 /* DTrace init */
66 LIN_SDT_PROVIDER_DECLARE(LINUX_DTRACE);
67 
68 /**
69  * DTrace probes in this module.
70  */
71 LIN_SDT_PROBE_DEFINE5(util, linux_emul_convpath, entry, "const char *",
72     "enum uio_seg", "char **", "int", "int");
73 LIN_SDT_PROBE_DEFINE1(util, linux_emul_convpath, return, "int");
74 LIN_SDT_PROBE_DEFINE1(util, linux_msg, entry, "const char *");
75 LIN_SDT_PROBE_DEFINE0(util, linux_msg, return);
76 LIN_SDT_PROBE_DEFINE2(util, linux_driver_get_name_dev, entry, "device_t",
77     "const char *");
78 LIN_SDT_PROBE_DEFINE0(util, linux_driver_get_name_dev, nullcall);
79 LIN_SDT_PROBE_DEFINE1(util, linux_driver_get_name_dev, return, "char *");
80 LIN_SDT_PROBE_DEFINE3(util, linux_driver_get_major_minor, entry, "char *",
81     "int *", "int *");
82 LIN_SDT_PROBE_DEFINE0(util, linux_driver_get_major_minor, nullcall);
83 LIN_SDT_PROBE_DEFINE1(util, linux_driver_get_major_minor, notfound, "char *");
84 LIN_SDT_PROBE_DEFINE3(util, linux_driver_get_major_minor, return, "int",
85     "int", "int");
86 LIN_SDT_PROBE_DEFINE0(util, linux_get_char_devices, entry);
87 LIN_SDT_PROBE_DEFINE1(util, linux_get_char_devices, return, "char *");
88 LIN_SDT_PROBE_DEFINE1(util, linux_free_get_char_devices, entry, "char *");
89 LIN_SDT_PROBE_DEFINE0(util, linux_free_get_char_devices, return);
90 LIN_SDT_PROBE_DEFINE1(util, linux_device_register_handler, entry,
91     "struct linux_device_handler *");
92 LIN_SDT_PROBE_DEFINE1(util, linux_device_register_handler, return, "int");
93 LIN_SDT_PROBE_DEFINE1(util, linux_device_unregister_handler, entry,
94     "struct linux_device_handler *");
95 LIN_SDT_PROBE_DEFINE1(util, linux_device_unregister_handler, return, "int");
96 
97 /*
98  * Search an alternate path before passing pathname arguments on to
99  * system calls. Useful for keeping a separate 'emulation tree'.
100  *
101  * If cflag is set, we check if an attempt can be made to create the
102  * named file, i.e. we check if the directory it should be in exists.
103  */
104 int
105 linux_emul_convpath(struct thread *td, const char *path, enum uio_seg pathseg,
106     char **pbuf, int cflag, int dfd)
107 {
108 	int retval;
109 
110 	LIN_SDT_PROBE5(util, linux_emul_convpath, entry, path, pathseg, pbuf,
111 	    cflag, dfd);
112 
113 	retval = kern_alternate_path(td, linux_emul_path, path, pathseg, pbuf,
114 	    cflag, dfd);
115 
116 	LIN_SDT_PROBE1(util, linux_emul_convpath, return, retval);
117 	return (retval);
118 }
119 
120 void
121 linux_msg(const struct thread *td, const char *fmt, ...)
122 {
123 	va_list ap;
124 	struct proc *p;
125 
126 	LIN_SDT_PROBE1(util, linux_msg, entry, fmt);
127 
128 	p = td->td_proc;
129 	printf("linux: pid %d (%s): ", (int)p->p_pid, p->p_comm);
130 	va_start(ap, fmt);
131 	vprintf(fmt, ap);
132 	va_end(ap);
133 	printf("\n");
134 
135 	LIN_SDT_PROBE0(util, linux_msg, return);
136 }
137 
138 struct device_element
139 {
140 	TAILQ_ENTRY(device_element) list;
141 	struct linux_device_handler entry;
142 };
143 
144 static TAILQ_HEAD(, device_element) devices =
145 	TAILQ_HEAD_INITIALIZER(devices);
146 
147 static struct linux_device_handler null_handler =
148 	{ "mem", "mem", "null", "null", 1, 3, 1};
149 
150 DATA_SET(linux_device_handler_set, null_handler);
151 
152 char *
153 linux_driver_get_name_dev(device_t dev)
154 {
155 	struct device_element *de;
156 	const char *device_name = device_get_name(dev);
157 
158 	LIN_SDT_PROBE2(util, linux_driver_get_name_dev, entry, dev,
159 	    device_name);
160 
161 	if (device_name == NULL) {
162 		LIN_SDT_PROBE0(util, linux_driver_get_name_dev, nullcall);
163 		LIN_SDT_PROBE1(util, linux_driver_get_name_dev, return, NULL);
164 		return NULL;
165 	}
166 	TAILQ_FOREACH(de, &devices, list) {
167 		if (strcmp(device_name, de->entry.bsd_driver_name) == 0) {
168 			LIN_SDT_PROBE1(util, linux_driver_get_name_dev, return,
169 			    de->entry.linux_driver_name);
170 			return (de->entry.linux_driver_name);
171 		}
172 	}
173 
174 	LIN_SDT_PROBE1(util, linux_driver_get_name_dev, return, NULL);
175 	return NULL;
176 }
177 
178 int
179 linux_driver_get_major_minor(const char *node, int *major, int *minor)
180 {
181 	struct device_element *de;
182 
183 	LIN_SDT_PROBE3(util, linux_driver_get_major_minor, entry, node, major,
184 	    minor);
185 
186 	if (node == NULL || major == NULL || minor == NULL) {
187 		LIN_SDT_PROBE0(util, linux_driver_get_major_minor, nullcall);
188 		LIN_SDT_PROBE3(util, linux_driver_get_major_minor, return, 1,
189 		   0, 0);
190 		return 1;
191 	}
192 
193 	if (strlen(node) > strlen("pts/") &&
194 	    strncmp(node, "pts/", strlen("pts/")) == 0) {
195 		unsigned long devno;
196 
197 		/*
198 		 * Linux checks major and minors of the slave device
199 		 * to make sure it's a pty device, so let's make him
200 		 * believe it is.
201 		 */
202 		devno = strtoul(node + strlen("pts/"), NULL, 10);
203 		*major = 136 + (devno / 256);
204 		*minor = devno % 256;
205 
206 		LIN_SDT_PROBE3(util, linux_driver_get_major_minor, return, 0,
207 		    *major, *minor);
208 		return 0;
209 	}
210 
211 	TAILQ_FOREACH(de, &devices, list) {
212 		if (strcmp(node, de->entry.bsd_device_name) == 0) {
213 			*major = de->entry.linux_major;
214 			*minor = de->entry.linux_minor;
215 
216 			LIN_SDT_PROBE3(util, linux_driver_get_major_minor,
217 			    return, 0, *major, *minor);
218 			return 0;
219 		}
220 	}
221 
222 	LIN_SDT_PROBE1(util, linux_driver_get_major_minor, notfound, node);
223 	LIN_SDT_PROBE3(util, linux_driver_get_major_minor, return, 1, 0, 0);
224 	return 1;
225 }
226 
227 char *
228 linux_get_char_devices()
229 {
230 	struct device_element *de;
231 	char *temp, *string, *last;
232 	char formated[256];
233 	int current_size = 0, string_size = 1024;
234 
235 	LIN_SDT_PROBE0(util, linux_get_char_devices, entry);
236 
237 	string = malloc(string_size, M_LINUX, M_WAITOK);
238 	string[0] = '\000';
239 	last = "";
240 	TAILQ_FOREACH(de, &devices, list) {
241 		if (!de->entry.linux_char_device)
242 			continue;
243 		temp = string;
244 		if (strcmp(last, de->entry.bsd_driver_name) != 0) {
245 			last = de->entry.bsd_driver_name;
246 
247 			snprintf(formated, sizeof(formated), "%3d %s\n",
248 				 de->entry.linux_major,
249 				 de->entry.linux_device_name);
250 			if (strlen(formated) + current_size
251 			    >= string_size) {
252 				string_size *= 2;
253 				string = malloc(string_size,
254 				    M_LINUX, M_WAITOK);
255 				bcopy(temp, string, current_size);
256 				free(temp, M_LINUX);
257 			}
258 			strcat(string, formated);
259 			current_size = strlen(string);
260 		}
261 	}
262 
263 	LIN_SDT_PROBE1(util, linux_get_char_devices, return, string);
264 	return string;
265 }
266 
267 void
268 linux_free_get_char_devices(char *string)
269 {
270 
271 	LIN_SDT_PROBE1(util, linux_get_char_devices, entry, string);
272 
273 	free(string, M_LINUX);
274 
275 	LIN_SDT_PROBE0(util, linux_get_char_devices, return);
276 }
277 
278 static int linux_major_starting = 200;
279 
280 int
281 linux_device_register_handler(struct linux_device_handler *d)
282 {
283 	struct device_element *de;
284 
285 	LIN_SDT_PROBE1(util, linux_device_register_handler, entry, d);
286 
287 	if (d == NULL) {
288 		LIN_SDT_PROBE1(util, linux_device_register_handler, return,
289 		    EINVAL);
290 		return (EINVAL);
291 	}
292 
293 	de = malloc(sizeof(*de), M_LINUX, M_WAITOK);
294 	if (d->linux_major < 0) {
295 		d->linux_major = linux_major_starting++;
296 	}
297 	bcopy(d, &de->entry, sizeof(*d));
298 
299 	/* Add the element to the list, sorted on span. */
300 	TAILQ_INSERT_TAIL(&devices, de, list);
301 
302 	LIN_SDT_PROBE1(util, linux_device_register_handler, return, 0);
303 	return (0);
304 }
305 
306 int
307 linux_device_unregister_handler(struct linux_device_handler *d)
308 {
309 	struct device_element *de;
310 
311 	LIN_SDT_PROBE1(util, linux_device_unregister_handler, entry, d);
312 
313 	if (d == NULL) {
314 		LIN_SDT_PROBE1(util, linux_device_unregister_handler, return,
315 		    EINVAL);
316 		return (EINVAL);
317 	}
318 
319 	TAILQ_FOREACH(de, &devices, list) {
320 		if (bcmp(d, &de->entry, sizeof(*d)) == 0) {
321 			TAILQ_REMOVE(&devices, de, list);
322 			free(de, M_LINUX);
323 
324 			LIN_SDT_PROBE1(util, linux_device_unregister_handler,
325 			    return, 0);
326 			return (0);
327 		}
328 	}
329 
330 	LIN_SDT_PROBE1(util, linux_device_unregister_handler, return, EINVAL);
331 	return (EINVAL);
332 }
333