xref: /netbsd-src/usr.bin/pmap/main.c (revision 181254a7b1bdde6873432bffef2d2decc4b5c22f)
1 /*	$NetBSD: main.c,v 1.28 2020/03/22 14:41:32 ad Exp $ */
2 
3 /*
4  * Copyright (c) 2002, 2003, 2020 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Andrew Brown.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 #ifndef lint
34 __RCSID("$NetBSD: main.c,v 1.28 2020/03/22 14:41:32 ad Exp $");
35 #endif
36 
37 #include <sys/param.h>
38 
39 #ifndef __NetBSD_Version__
40 #error go away, you fool
41 #elif (__NetBSD_Version__ < 105000000)
42 #error only works with uvm
43 #endif
44 
45 #include <fcntl.h>
46 #include <errno.h>
47 #include <unistd.h>
48 #include <limits.h>
49 #include <string.h>
50 #include <signal.h>
51 #include <util.h>
52 
53 #include "pmap.h"
54 #include "main.h"
55 
56 struct cache_head lcache;
57 void *uvm_vnodeops, *uvm_deviceops, *aobj_pager, *ubc_pager;
58 struct vm_map *kmem_map, *phys_map, *exec_map, *pager_map;
59 struct vm_map *st_map, *pt_map, *module_map, *buf_map;
60 u_long kernel_map_addr;
61 int debug, verbose, recurse, page_size;
62 int print_all, print_map, print_maps, print_solaris, print_ddb;
63 rlim_t maxssiz;
64 
65 struct nlist ksyms[] = {
66 	{ "_maxsmap", 0, 0, 0, 0 },
67 #define NL_MAXSSIZ		0
68 	{ "_uvm_vnodeops", 0, 0, 0, 0 },
69 #define NL_UVM_VNODEOPS		1
70 	{ "_uvm_deviceops", 0, 0, 0, 0 },
71 #define NL_UVM_DEVICEOPS	2
72 	{ "_aobj_pager", 0, 0, 0, 0 },
73 #define NL_AOBJ_PAGER		3
74 	{ "_ubc_pager", 0, 0, 0, 0 },
75 #define NL_UBC_PAGER		4
76 	{ "_kernel_map", 0, 0, 0, 0 },
77 #define NL_KERNEL_MAP		5
78 	{ NULL, 0, 0, 0, 0 }
79 };
80 
81 struct nlist kmaps[] = {
82 	{ "_kmem_map", 0, 0, 0, 0 },
83 #define NL_kmem_map		0
84 	{ "_phys_map", 0, 0, 0, 0 },
85 #define NL_phys_map		1
86 	{ "_exec_map", 0, 0, 0, 0 },
87 #define NL_exec_map		2
88 	{ "_pager_map", 0, 0, 0, 0 },
89 #define NL_pager_map		3
90 	{ "_st_map", 0, 0, 0, 0 },
91 #define NL_st_map		4
92 	{ "_pt_map", 0, 0, 0, 0 },
93 #define NL_pt_map		5
94 	{ "_module_map", 0, 0, 0, 0 },
95 #define NL_module_map		6
96 	{ "_buf_map", 0, 0, 0, 0 },
97 #define NL_buf_map		7
98 	{ NULL, 0, 0, 0, 0 },
99 };
100 
101 #define VMSPACE_ADDRESS		1
102 #define VM_MAP_ADDRESS		2
103 #define VM_MAP_ENTRY_ADDRESS	3
104 #define AMAP_ADDRESS		4
105 
106 void check_fd(int);
107 void load_symbols(kvm_t *);
108 void cache_enter(u_long, struct namecache *);
109 
110 int
111 main(int argc, char *argv[])
112 {
113 	kvm_t *kd;
114 	pid_t pid;
115 	uid_t uid;
116 	int which, many, ch, rc;
117 	char errbuf[_POSIX2_LINE_MAX + 1];
118 	struct kinfo_proc2 *kproc;
119 	char *kmem, *kernel, *t;
120 	gid_t egid;
121 	struct kbit kbit, *vmspace;
122 	u_long address;
123 
124 	egid = getegid();
125 	if (setegid(getgid()) == -1)
126 		err(1, "failed to reset privileges");
127 
128 	check_fd(STDIN_FILENO);
129 	check_fd(STDOUT_FILENO);
130 	check_fd(STDERR_FILENO);
131 
132 	pid = -1;
133 	which = verbose = debug = 0;
134 	print_all = print_map = print_maps = print_solaris = print_ddb = 0;
135 	recurse = 0;
136 	kmem = kernel = NULL;
137 	address = 0;
138 	vmspace = &kbit;
139 
140 	while ((ch = getopt(argc, argv, "A:aD:dE:lM:mN:Pp:RrS:sV:vx")) != -1) {
141 		switch (ch) {
142 		case 'A':
143 		case 'E':
144 		case 'S':
145 		case 'V':
146 			if (which != 0)
147 				errx(1, "use only one of -A, -E, -S, or -V");
148 			errno = 0;
149 			address = strtoul(optarg, &t, 0);
150 			if (*t != '\0')
151 				errx(1, "%s is not a valid address", optarg);
152 			if (errno != 0)
153 				err(1, "%s is not a valid address", optarg);
154 			switch (ch) {
155 			case 'A':	which = AMAP_ADDRESS;		break;
156 			case 'E':	which = VM_MAP_ENTRY_ADDRESS;	break;
157 			case 'S':	which = VMSPACE_ADDRESS;	break;
158 			case 'V':	which = VM_MAP_ADDRESS;		break;
159 			}
160 			break;
161 		case 'a':
162 			print_all = 1;
163 			break;
164 		case 'd':
165 			print_ddb = 1;
166 			break;
167 		case 'D':
168 			errno = 0;
169 			debug = strtoul(optarg, &t, 0);
170 			if (*t != '\0')
171 				errx(1, "%s is not a valid number", optarg);
172 			if (errno != 0)
173 				err(1, "%s is not a valid number", optarg);
174 			break;
175 		case 'l':
176 			print_maps = 1;
177 			break;
178 		case 'm':
179 			print_map = 1;
180 			break;
181 		case 'M':
182 			kmem = optarg;
183 			break;
184 		case 'N':
185 			kernel = optarg;
186 			break;
187 		case 'p':
188 			errno = 0;
189 			pid = strtol(optarg, &t, 0);
190 			if (pid < 0)
191 				errno = EINVAL;
192 			if (*t != '\0')
193 				errx(1, "%s is not a valid pid", optarg);
194 			if (errno != 0)
195 				err(1, "%s is not a valid pid", optarg);
196 			break;
197 		case 'P':
198 			pid = getpid();
199 			break;
200 		case 'R':
201 			recurse = 1;
202 			break;
203 		case 's':
204 			print_solaris = 1;
205 			break;
206 		case 'v':
207 			verbose++;
208 			break;
209 		case 'r':
210 		case 'x':
211 			errx(1, "-%c option not implemented, sorry", optopt);
212 			/*NOTREACHED*/
213 		case '?':
214 		default:
215 			fprintf(stderr, "usage: %s [-adlmPRsv] [-A address] "
216 				"[-D number] [-E address] [-M core]\n"
217 				"\t[-N system] [-p pid] [-S address] "
218 				"[-V address] [pid ...]\n",
219 				getprogname());
220 			exit(1);
221 		}
222 	}
223 	argc -= optind;
224 	argv += optind;
225 
226 	/* more than one "process" to dump? */
227 	many = (argc > 1 - (pid == -1 ? 0 : 1)) ? 1 : 0;
228 
229 	/* apply default */
230 	if (print_all + print_map + print_maps + print_solaris +
231 	    print_ddb == 0)
232 		print_solaris = 1;
233 
234 	/* get privs back if it appears to be safe, otherwise toss them */
235 	if (kernel == NULL && kmem == NULL && address == 0)
236 		rc = setegid(egid);
237 	else
238 		rc = setgid(getgid());
239 	if (rc == -1)
240 		err(1, "failed to reset privileges");
241 
242 	/* start by opening libkvm */
243 	kd = kvm_openfiles(kernel, kmem, NULL, O_RDONLY, errbuf);
244 
245 	/* we're completely done with privileges now */
246 	rc = setgid(getgid());
247 	if (rc == -1)
248 		err(1, "failed to reset privileges");
249 
250 	/* print the kvm_open error, if any */
251 	errbuf[_POSIX2_LINE_MAX] = '\0';
252 	if (kd == NULL)
253 		errx(1, "%s", errbuf);
254 
255 	/* get "bootstrap" addresses from kernel */
256 	load_symbols(kd);
257 
258 	if (address) {
259 		struct kbit kbit2, *at = &kbit2;
260 
261 		memset(vmspace, 0, sizeof(*vmspace));
262 		A(at) = address;
263 		S(at) = (size_t)-1;
264 
265 		switch (which) {
266 		    case VMSPACE_ADDRESS:
267 			/* (kd, kproc, vmspace, thing) */
268 			(*process_map)(kd, NULL, at, "vm_map");
269 			break;
270 		    case VM_MAP_ADDRESS:
271 			/* (kd, proc, vmspace, vm_map, thing) */
272 			(*dump_vm_map)(kd, NULL, vmspace, at, "vm_map");
273 			break;
274 		    case VM_MAP_ENTRY_ADDRESS:
275 			/* (kd, proc, vmspace, vm_map_entry, 0) */
276 			(*dump_vm_map_entry)(kd, NULL, vmspace, at, 0);
277 			break;
278 		    case AMAP_ADDRESS:
279 			/* (kd, amap) */
280 			(*dump_amap)(kd, at);
281 			break;
282 		}
283 		exit(0);
284 	}
285 
286 	uid = getuid();
287 
288 	do {
289 		if (pid == -1) {
290 			if (argc == 0)
291 				pid = getppid();
292 			else {
293 				errno = 0;
294 				pid = strtol(argv[0], &t, 0);
295 				if (pid < 0)
296 					errno = EINVAL;
297 				if (*t != '\0')
298 					errx(1, "%s is not a valid pid",
299 					    argv[0]);
300 				if (errno != 0)
301 					err(1, "%s is not a valid pid",
302 					    argv[0]);
303 				argv++;
304 				argc--;
305 			}
306 		}
307 
308 		errno = 0;
309 		/* find the process id */
310 		if (pid == 0) {
311 			kproc = NULL;
312 			if (uid != 0) {
313 				/* only root can print kernel mappings */
314 				errno = EPERM;
315 			}
316 		} else {
317 			kproc = kvm_getproc2(kd, KERN_PROC_PID, pid,
318 			    sizeof(struct kinfo_proc2), &rc);
319 			if (kproc == NULL || rc == 0) {
320 				errno = ESRCH;
321 			} else if (uid != 0 && uid != kproc->p_uid) {
322 				/*
323 				 * only the real owner of the process and
324 				 * root can print process mappings
325 				 */
326 				errno = EPERM;
327 			}
328 		}
329 
330 		if (errno != 0) {
331 			warn("%d", pid);
332 			pid = -1;
333 			continue;
334 		}
335 
336 		/* dump it */
337 		if (many) {
338 			if (kproc != NULL)
339 				printf("process %d:\n", kproc->p_pid);
340 			else
341 				printf("kernel:\n");
342 		}
343 
344 		(*process_map)(kd, kproc, vmspace, NULL);
345 		pid = -1;
346 	} while (argc > 0);
347 
348 	/* done.  go away. */
349 	rc = kvm_close(kd);
350 	if (rc == -1)
351 		err(1, "kvm_close");
352 
353 	return (0);
354 }
355 
356 void
357 check_fd(int fd)
358 {
359 	struct stat st;
360 	int n;
361 
362 	if (fstat(fd, &st) == -1) {
363 		(void)close(fd);
364 		n = open("/dev/null", O_RDWR);
365 		if (n == fd || n == -1)
366 			/* we're either done or we can do no more */
367 			return;
368 		/* if either of these fail, there's not much we can do */
369 		(void)dup2(n, fd);
370 		(void)close(n);
371 		/* XXX should we exit if it fails? */
372 	}
373 }
374 
375 void
376 load_symbols(kvm_t *kd)
377 {
378 	int rc, i, mib[2];
379 	size_t sz;
380 
381 	rc = kvm_nlist(kd, &ksyms[0]);
382 	if (rc != 0) {
383 		for (i = 0; ksyms[i].n_name != NULL; i++)
384 			if (ksyms[i].n_value == 0)
385 				warnx("symbol %s: not found", ksyms[i].n_name);
386 		exit(1);
387 	}
388 
389 	uvm_vnodeops =	(void*)ksyms[NL_UVM_VNODEOPS].n_value;
390 	uvm_deviceops =	(void*)ksyms[NL_UVM_DEVICEOPS].n_value;
391 	aobj_pager =	(void*)ksyms[NL_AOBJ_PAGER].n_value;
392 	ubc_pager =	(void*)ksyms[NL_UBC_PAGER].n_value;
393 
394 	_KDEREF(kd, ksyms[NL_MAXSSIZ].n_value, &maxssiz,
395 		sizeof(maxssiz));
396 	_KDEREF(kd, ksyms[NL_KERNEL_MAP].n_value, &kernel_map_addr,
397 		sizeof(kernel_map_addr));
398 
399 	/*
400 	 * Some of these may be missing from some platforms, for
401 	 * example sparc, sh3, and most powerpc platforms don't
402 	 * have a "phys_map", etc.
403 	 */
404 	(void)kvm_nlist(kd, &kmaps[0]);
405 
406 #define get_map_address(m) do {\
407 	if (kmaps[__CONCAT(NL_,m)].n_value != 0) \
408 		_KDEREF(kd, kmaps[__CONCAT(NL_,m)].n_value, &m, sizeof(m)); \
409 	} while (0/*CONSTCOND*/)
410 
411 	get_map_address(kmem_map);
412 	get_map_address(phys_map);
413 	get_map_address(exec_map);
414 	get_map_address(pager_map);
415 	get_map_address(st_map);
416 	get_map_address(pt_map);
417 	get_map_address(module_map);
418 	get_map_address(buf_map);
419 
420 	mib[0] = CTL_HW;
421 	mib[1] = HW_PAGESIZE;
422 	sz = sizeof(page_size);
423 	if (sysctl(&mib[0], 2, &page_size, &sz, NULL, 0) == -1)
424 		err(1, "sysctl: hw.pagesize");
425 }
426 
427 const char *
428 mapname(void *addr)
429 {
430 
431 	if (addr == (void*)kernel_map_addr)
432 		return ("kernel_map");
433 	else if (addr == kmem_map)
434 		return ("kmem_map");
435 	else if (addr == phys_map)
436 		return ("phys_map");
437 	else if (addr == exec_map)
438 		return ("exec_map");
439 	else if (addr == pager_map)
440 		return ("pager_map");
441 	else if (addr == st_map)
442 		return ("st_map");
443 	else if (addr == pt_map)
444 		return ("pt_map");
445 	else if (addr == module_map)
446 		return ("module_map");
447 	else if (addr == buf_map)
448 		return ("buf_map");
449 	else
450 		return (NULL);
451 }
452