1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1989, 1992, 1993
5 * The Regents of the University of California. All rights reserved.
6 *
7 * This code is derived from software developed by the Computer Systems
8 * Engineering group at Lawrence Berkeley Laboratory under DARPA contract
9 * BG 91-66 and contributed to Berkeley.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 3. Neither the name of the University nor the names of its contributors
20 * may be used to endorse or promote products derived from this software
21 * without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 */
35
36
37 /*
38 * i386 machine dependent routines for kvm. Hopefully, the forthcoming
39 * vm code will one day obsolete this module.
40 */
41
42 #include <sys/param.h>
43 #include <sys/endian.h>
44 #include <stdint.h>
45 #include <stdlib.h>
46 #include <string.h>
47 #include <unistd.h>
48 #include <vm/vm.h>
49 #include <kvm.h>
50
51 #ifdef __i386__
52 #include <machine/vmparam.h> /* For KERNBASE. */
53 #endif
54
55 #include <limits.h>
56
57 #include "kvm_private.h"
58 #include "kvm_i386.h"
59
60 struct vmstate {
61 void *PTD;
62 int pae;
63 size_t phnum;
64 GElf_Phdr *phdr;
65 };
66
67 /*
68 * Translate a physical memory address to a file-offset in the crash-dump.
69 */
70 static size_t
_kvm_pa2off(kvm_t * kd,uint64_t pa,off_t * ofs)71 _kvm_pa2off(kvm_t *kd, uint64_t pa, off_t *ofs)
72 {
73 struct vmstate *vm = kd->vmst;
74 GElf_Phdr *p;
75 size_t n;
76
77 if (kd->rawdump) {
78 *ofs = pa;
79 return (I386_PAGE_SIZE - (pa & I386_PAGE_MASK));
80 }
81
82 p = vm->phdr;
83 n = vm->phnum;
84 while (n && (pa < p->p_paddr || pa >= p->p_paddr + p->p_memsz))
85 p++, n--;
86 if (n == 0)
87 return (0);
88 *ofs = (pa - p->p_paddr) + p->p_offset;
89 return (I386_PAGE_SIZE - (pa & I386_PAGE_MASK));
90 }
91
92 static void
_i386_freevtop(kvm_t * kd)93 _i386_freevtop(kvm_t *kd)
94 {
95 struct vmstate *vm = kd->vmst;
96
97 if (vm->PTD)
98 free(vm->PTD);
99 free(vm->phdr);
100 free(vm);
101 kd->vmst = NULL;
102 }
103
104 static int
_i386_probe(kvm_t * kd)105 _i386_probe(kvm_t *kd)
106 {
107
108 return (_kvm_probe_elf_kernel(kd, ELFCLASS32, EM_386) &&
109 !_kvm_is_minidump(kd));
110 }
111
112 static int
_i386_initvtop(kvm_t * kd)113 _i386_initvtop(kvm_t *kd)
114 {
115 struct kvm_nlist nl[2];
116 i386_physaddr_t pa;
117 kvaddr_t kernbase;
118 char *PTD;
119 int i;
120
121 kd->vmst = (struct vmstate *)_kvm_malloc(kd, sizeof(struct vmstate));
122 if (kd->vmst == NULL) {
123 _kvm_err(kd, kd->program, "cannot allocate vm");
124 return (-1);
125 }
126 kd->vmst->PTD = 0;
127
128 if (kd->rawdump == 0) {
129 if (_kvm_read_core_phdrs(kd, &kd->vmst->phnum,
130 &kd->vmst->phdr) == -1)
131 return (-1);
132 }
133
134 nl[0].n_name = "kernbase";
135 nl[1].n_name = 0;
136
137 if (kvm_nlist2(kd, nl) != 0) {
138 #ifdef __i386__
139 kernbase = KERNBASE; /* for old kernels */
140 #else
141 _kvm_err(kd, kd->program, "cannot resolve kernbase");
142 return (-1);
143 #endif
144 } else
145 kernbase = nl[0].n_value;
146
147 nl[0].n_name = "IdlePDPT";
148 nl[1].n_name = 0;
149
150 if (kvm_nlist2(kd, nl) == 0) {
151 i386_physaddr_pae_t pa64;
152
153 if (kvm_read2(kd, (nl[0].n_value - kernbase), &pa,
154 sizeof(pa)) != sizeof(pa)) {
155 _kvm_err(kd, kd->program, "cannot read IdlePDPT");
156 return (-1);
157 }
158 pa = le32toh(pa);
159 PTD = _kvm_malloc(kd, 4 * I386_PAGE_SIZE);
160 if (PTD == NULL) {
161 _kvm_err(kd, kd->program, "cannot allocate PTD");
162 return (-1);
163 }
164 for (i = 0; i < 4; i++) {
165 if (kvm_read2(kd, pa + (i * sizeof(pa64)), &pa64,
166 sizeof(pa64)) != sizeof(pa64)) {
167 _kvm_err(kd, kd->program, "Cannot read PDPT");
168 free(PTD);
169 return (-1);
170 }
171 pa64 = le64toh(pa64);
172 if (kvm_read2(kd, pa64 & I386_PG_FRAME_PAE,
173 PTD + (i * I386_PAGE_SIZE), I386_PAGE_SIZE) !=
174 I386_PAGE_SIZE) {
175 _kvm_err(kd, kd->program, "cannot read PDPT");
176 free(PTD);
177 return (-1);
178 }
179 }
180 kd->vmst->PTD = PTD;
181 kd->vmst->pae = 1;
182 } else {
183 nl[0].n_name = "IdlePTD";
184 nl[1].n_name = 0;
185
186 if (kvm_nlist2(kd, nl) != 0) {
187 _kvm_err(kd, kd->program, "bad namelist");
188 return (-1);
189 }
190 if (kvm_read2(kd, (nl[0].n_value - kernbase), &pa,
191 sizeof(pa)) != sizeof(pa)) {
192 _kvm_err(kd, kd->program, "cannot read IdlePTD");
193 return (-1);
194 }
195 pa = le32toh(pa);
196 PTD = _kvm_malloc(kd, I386_PAGE_SIZE);
197 if (PTD == NULL) {
198 _kvm_err(kd, kd->program, "cannot allocate PTD");
199 return (-1);
200 }
201 if (kvm_read2(kd, pa, PTD, I386_PAGE_SIZE) != I386_PAGE_SIZE) {
202 _kvm_err(kd, kd->program, "cannot read PTD");
203 return (-1);
204 }
205 kd->vmst->PTD = PTD;
206 kd->vmst->pae = 0;
207 }
208 return (0);
209 }
210
211 static int
_i386_vatop(kvm_t * kd,kvaddr_t va,off_t * pa)212 _i386_vatop(kvm_t *kd, kvaddr_t va, off_t *pa)
213 {
214 struct vmstate *vm;
215 i386_physaddr_t offset;
216 i386_physaddr_t pte_pa;
217 i386_pde_t pde;
218 i386_pte_t pte;
219 kvaddr_t pdeindex;
220 kvaddr_t pteindex;
221 size_t s;
222 i386_physaddr_t a;
223 off_t ofs;
224 i386_pde_t *PTD;
225
226 vm = kd->vmst;
227 PTD = (i386_pde_t *)vm->PTD;
228 offset = va & I386_PAGE_MASK;
229
230 /*
231 * If we are initializing (kernel page table descriptor pointer
232 * not yet set) then return pa == va to avoid infinite recursion.
233 */
234 if (PTD == NULL) {
235 s = _kvm_pa2off(kd, va, pa);
236 if (s == 0) {
237 _kvm_err(kd, kd->program,
238 "_i386_vatop: bootstrap data not in dump");
239 goto invalid;
240 } else
241 return (I386_PAGE_SIZE - offset);
242 }
243
244 pdeindex = va >> I386_PDRSHIFT;
245 pde = le32toh(PTD[pdeindex]);
246 if ((pde & I386_PG_V) == 0) {
247 _kvm_err(kd, kd->program, "_i386_vatop: pde not valid");
248 goto invalid;
249 }
250
251 if (pde & I386_PG_PS) {
252 /*
253 * No second-level page table; ptd describes one 4MB
254 * page. (We assume that the kernel wouldn't set
255 * PG_PS without enabling it cr0).
256 */
257 offset = va & I386_PAGE_PS_MASK;
258 a = (pde & I386_PG_PS_FRAME) + offset;
259 s = _kvm_pa2off(kd, a, pa);
260 if (s == 0) {
261 _kvm_err(kd, kd->program,
262 "_i386_vatop: 4MB page address not in dump");
263 goto invalid;
264 }
265 return (I386_NBPDR - offset);
266 }
267
268 pteindex = (va >> I386_PAGE_SHIFT) & (I386_NPTEPG - 1);
269 pte_pa = (pde & I386_PG_FRAME) + (pteindex * sizeof(pte));
270
271 s = _kvm_pa2off(kd, pte_pa, &ofs);
272 if (s < sizeof(pte)) {
273 _kvm_err(kd, kd->program, "_i386_vatop: pte_pa not found");
274 goto invalid;
275 }
276
277 /* XXX This has to be a physical address read, kvm_read is virtual */
278 if (pread(kd->pmfd, &pte, sizeof(pte), ofs) != sizeof(pte)) {
279 _kvm_syserr(kd, kd->program, "_i386_vatop: pread");
280 goto invalid;
281 }
282 pte = le32toh(pte);
283 if ((pte & I386_PG_V) == 0) {
284 _kvm_err(kd, kd->program, "_kvm_kvatop: pte not valid");
285 goto invalid;
286 }
287
288 a = (pte & I386_PG_FRAME) + offset;
289 s = _kvm_pa2off(kd, a, pa);
290 if (s == 0) {
291 _kvm_err(kd, kd->program, "_i386_vatop: address not in dump");
292 goto invalid;
293 } else
294 return (I386_PAGE_SIZE - offset);
295
296 invalid:
297 _kvm_err(kd, 0, "invalid address (0x%jx)", (uintmax_t)va);
298 return (0);
299 }
300
301 static int
_i386_vatop_pae(kvm_t * kd,kvaddr_t va,off_t * pa)302 _i386_vatop_pae(kvm_t *kd, kvaddr_t va, off_t *pa)
303 {
304 struct vmstate *vm;
305 i386_physaddr_pae_t offset;
306 i386_physaddr_pae_t pte_pa;
307 i386_pde_pae_t pde;
308 i386_pte_pae_t pte;
309 kvaddr_t pdeindex;
310 kvaddr_t pteindex;
311 size_t s;
312 i386_physaddr_pae_t a;
313 off_t ofs;
314 i386_pde_pae_t *PTD;
315
316 vm = kd->vmst;
317 PTD = (i386_pde_pae_t *)vm->PTD;
318 offset = va & I386_PAGE_MASK;
319
320 /*
321 * If we are initializing (kernel page table descriptor pointer
322 * not yet set) then return pa == va to avoid infinite recursion.
323 */
324 if (PTD == NULL) {
325 s = _kvm_pa2off(kd, va, pa);
326 if (s == 0) {
327 _kvm_err(kd, kd->program,
328 "_i386_vatop_pae: bootstrap data not in dump");
329 goto invalid;
330 } else
331 return (I386_PAGE_SIZE - offset);
332 }
333
334 pdeindex = va >> I386_PDRSHIFT_PAE;
335 pde = le64toh(PTD[pdeindex]);
336 if ((pde & I386_PG_V) == 0) {
337 _kvm_err(kd, kd->program, "_kvm_kvatop_pae: pde not valid");
338 goto invalid;
339 }
340
341 if (pde & I386_PG_PS) {
342 /*
343 * No second-level page table; ptd describes one 2MB
344 * page. (We assume that the kernel wouldn't set
345 * PG_PS without enabling it cr0).
346 */
347 offset = va & I386_PAGE_PS_MASK_PAE;
348 a = (pde & I386_PG_PS_FRAME_PAE) + offset;
349 s = _kvm_pa2off(kd, a, pa);
350 if (s == 0) {
351 _kvm_err(kd, kd->program,
352 "_i386_vatop: 2MB page address not in dump");
353 goto invalid;
354 }
355 return (I386_NBPDR_PAE - offset);
356 }
357
358 pteindex = (va >> I386_PAGE_SHIFT) & (I386_NPTEPG_PAE - 1);
359 pte_pa = (pde & I386_PG_FRAME_PAE) + (pteindex * sizeof(pde));
360
361 s = _kvm_pa2off(kd, pte_pa, &ofs);
362 if (s < sizeof(pte)) {
363 _kvm_err(kd, kd->program, "_i386_vatop_pae: pdpe_pa not found");
364 goto invalid;
365 }
366
367 /* XXX This has to be a physical address read, kvm_read is virtual */
368 if (pread(kd->pmfd, &pte, sizeof(pte), ofs) != sizeof(pte)) {
369 _kvm_syserr(kd, kd->program, "_i386_vatop_pae: read");
370 goto invalid;
371 }
372 pte = le64toh(pte);
373 if ((pte & I386_PG_V) == 0) {
374 _kvm_err(kd, kd->program, "_i386_vatop_pae: pte not valid");
375 goto invalid;
376 }
377
378 a = (pte & I386_PG_FRAME_PAE) + offset;
379 s = _kvm_pa2off(kd, a, pa);
380 if (s == 0) {
381 _kvm_err(kd, kd->program,
382 "_i386_vatop_pae: address not in dump");
383 goto invalid;
384 } else
385 return (I386_PAGE_SIZE - offset);
386
387 invalid:
388 _kvm_err(kd, 0, "invalid address (0x%jx)", (uintmax_t)va);
389 return (0);
390 }
391
392 static int
_i386_kvatop(kvm_t * kd,kvaddr_t va,off_t * pa)393 _i386_kvatop(kvm_t *kd, kvaddr_t va, off_t *pa)
394 {
395
396 if (ISALIVE(kd)) {
397 _kvm_err(kd, 0, "vatop called in live kernel!");
398 return (0);
399 }
400 if (kd->vmst->pae)
401 return (_i386_vatop_pae(kd, va, pa));
402 else
403 return (_i386_vatop(kd, va, pa));
404 }
405
406 int
_i386_native(kvm_t * kd __unused)407 _i386_native(kvm_t *kd __unused)
408 {
409
410 #ifdef __i386__
411 return (1);
412 #else
413 return (0);
414 #endif
415 }
416
417 static struct kvm_arch kvm_i386 = {
418 .ka_probe = _i386_probe,
419 .ka_initvtop = _i386_initvtop,
420 .ka_freevtop = _i386_freevtop,
421 .ka_kvatop = _i386_kvatop,
422 .ka_native = _i386_native,
423 };
424
425 KVM_ARCH(kvm_i386);
426