1 /*-
2 * Copyright (c) 1989, 1992, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * This code is derived from software developed by the Computer Systems
6 * Engineering group at Lawrence Berkeley Laboratory under DARPA contract
7 * BG 91-66 and contributed to Berkeley.
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 * 4. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34 #include <sys/cdefs.h>
35 __FBSDID("$FreeBSD$");
36
37 #if defined(LIBC_SCCS) && !defined(lint)
38 #if 0
39 static char sccsid[] = "@(#)kvm_hp300.c 8.1 (Berkeley) 6/4/93";
40 #endif
41 #endif /* LIBC_SCCS and not lint */
42
43 /*
44 * i386 machine dependent routines for kvm. Hopefully, the forthcoming
45 * vm code will one day obsolete this module.
46 */
47
48 #include <sys/param.h>
49 #include <sys/endian.h>
50 #include <stdint.h>
51 #include <stdlib.h>
52 #include <string.h>
53 #include <unistd.h>
54 #include <kvm.h>
55
56 #ifdef __i386__
57 #include <machine/vmparam.h> /* For KERNBASE. */
58 #endif
59
60 #include <limits.h>
61
62 #include "kvm_private.h"
63 #include "kvm_i386.h"
64
65 struct vmstate {
66 void *PTD;
67 int pae;
68 size_t phnum;
69 GElf_Phdr *phdr;
70 };
71
72 /*
73 * Translate a physical memory address to a file-offset in the crash-dump.
74 */
75 static size_t
_kvm_pa2off(kvm_t * kd,uint64_t pa,off_t * ofs)76 _kvm_pa2off(kvm_t *kd, uint64_t pa, off_t *ofs)
77 {
78 struct vmstate *vm = kd->vmst;
79 GElf_Phdr *p;
80 size_t n;
81
82 if (kd->rawdump) {
83 *ofs = pa;
84 return (I386_PAGE_SIZE - (pa & I386_PAGE_MASK));
85 }
86
87 p = vm->phdr;
88 n = vm->phnum;
89 while (n && (pa < p->p_paddr || pa >= p->p_paddr + p->p_memsz))
90 p++, n--;
91 if (n == 0)
92 return (0);
93 *ofs = (pa - p->p_paddr) + p->p_offset;
94 return (I386_PAGE_SIZE - (pa & I386_PAGE_MASK));
95 }
96
97 static void
_i386_freevtop(kvm_t * kd)98 _i386_freevtop(kvm_t *kd)
99 {
100 struct vmstate *vm = kd->vmst;
101
102 if (vm->PTD)
103 free(vm->PTD);
104 free(vm->phdr);
105 free(vm);
106 kd->vmst = NULL;
107 }
108
109 static int
_i386_probe(kvm_t * kd)110 _i386_probe(kvm_t *kd)
111 {
112
113 return (_kvm_probe_elf_kernel(kd, ELFCLASS32, EM_386) &&
114 !_kvm_is_minidump(kd));
115 }
116
117 static int
_i386_initvtop(kvm_t * kd)118 _i386_initvtop(kvm_t *kd)
119 {
120 struct kvm_nlist nl[2];
121 i386_physaddr_t pa;
122 kvaddr_t kernbase;
123 char *PTD;
124 int i;
125
126 kd->vmst = (struct vmstate *)_kvm_malloc(kd, sizeof(struct vmstate));
127 if (kd->vmst == NULL) {
128 _kvm_err(kd, kd->program, "cannot allocate vm");
129 return (-1);
130 }
131 kd->vmst->PTD = 0;
132
133 if (kd->rawdump == 0) {
134 if (_kvm_read_core_phdrs(kd, &kd->vmst->phnum,
135 &kd->vmst->phdr) == -1)
136 return (-1);
137 }
138
139 nl[0].n_name = "kernbase";
140 nl[1].n_name = 0;
141
142 if (kvm_nlist2(kd, nl) != 0) {
143 #ifdef __i386__
144 kernbase = KERNBASE; /* for old kernels */
145 #else
146 _kvm_err(kd, kd->program, "cannot resolve kernbase");
147 return (-1);
148 #endif
149 } else
150 kernbase = nl[0].n_value;
151
152 nl[0].n_name = "IdlePDPT";
153 nl[1].n_name = 0;
154
155 if (kvm_nlist2(kd, nl) == 0) {
156 i386_physaddr_pae_t pa64;
157
158 if (kvm_read2(kd, (nl[0].n_value - kernbase), &pa,
159 sizeof(pa)) != sizeof(pa)) {
160 _kvm_err(kd, kd->program, "cannot read IdlePDPT");
161 return (-1);
162 }
163 pa = le32toh(pa);
164 PTD = _kvm_malloc(kd, 4 * I386_PAGE_SIZE);
165 for (i = 0; i < 4; i++) {
166 if (kvm_read2(kd, pa + (i * sizeof(pa64)), &pa64,
167 sizeof(pa64)) != sizeof(pa64)) {
168 _kvm_err(kd, kd->program, "Cannot read PDPT");
169 free(PTD);
170 return (-1);
171 }
172 pa64 = le64toh(pa64);
173 if (kvm_read2(kd, pa64 & I386_PG_FRAME_PAE,
174 PTD + (i * I386_PAGE_SIZE), I386_PAGE_SIZE) !=
175 I386_PAGE_SIZE) {
176 _kvm_err(kd, kd->program, "cannot read PDPT");
177 free(PTD);
178 return (-1);
179 }
180 }
181 kd->vmst->PTD = PTD;
182 kd->vmst->pae = 1;
183 } else {
184 nl[0].n_name = "IdlePTD";
185 nl[1].n_name = 0;
186
187 if (kvm_nlist2(kd, nl) != 0) {
188 _kvm_err(kd, kd->program, "bad namelist");
189 return (-1);
190 }
191 if (kvm_read2(kd, (nl[0].n_value - kernbase), &pa,
192 sizeof(pa)) != sizeof(pa)) {
193 _kvm_err(kd, kd->program, "cannot read IdlePTD");
194 return (-1);
195 }
196 pa = le32toh(pa);
197 PTD = _kvm_malloc(kd, I386_PAGE_SIZE);
198 if (kvm_read2(kd, pa, PTD, I386_PAGE_SIZE) != I386_PAGE_SIZE) {
199 _kvm_err(kd, kd->program, "cannot read PTD");
200 return (-1);
201 }
202 kd->vmst->PTD = PTD;
203 kd->vmst->pae = 0;
204 }
205 return (0);
206 }
207
208 static int
_i386_vatop(kvm_t * kd,kvaddr_t va,off_t * pa)209 _i386_vatop(kvm_t *kd, kvaddr_t va, off_t *pa)
210 {
211 struct vmstate *vm;
212 i386_physaddr_t offset;
213 i386_physaddr_t pte_pa;
214 i386_pde_t pde;
215 i386_pte_t pte;
216 kvaddr_t pdeindex;
217 kvaddr_t pteindex;
218 size_t s;
219 i386_physaddr_t a;
220 off_t ofs;
221 i386_pde_t *PTD;
222
223 vm = kd->vmst;
224 PTD = (i386_pde_t *)vm->PTD;
225 offset = va & I386_PAGE_MASK;
226
227 /*
228 * If we are initializing (kernel page table descriptor pointer
229 * not yet set) then return pa == va to avoid infinite recursion.
230 */
231 if (PTD == 0) {
232 s = _kvm_pa2off(kd, va, pa);
233 if (s == 0) {
234 _kvm_err(kd, kd->program,
235 "_i386_vatop: bootstrap data not in dump");
236 goto invalid;
237 } else
238 return (I386_PAGE_SIZE - offset);
239 }
240
241 pdeindex = va >> I386_PDRSHIFT;
242 pde = le32toh(PTD[pdeindex]);
243 if ((pde & I386_PG_V) == 0) {
244 _kvm_err(kd, kd->program, "_i386_vatop: pde not valid");
245 goto invalid;
246 }
247
248 if (pde & I386_PG_PS) {
249 /*
250 * No second-level page table; ptd describes one 4MB
251 * page. (We assume that the kernel wouldn't set
252 * PG_PS without enabling it cr0).
253 */
254 offset = va & I386_PAGE_PS_MASK;
255 a = (pde & I386_PG_PS_FRAME) + offset;
256 s = _kvm_pa2off(kd, a, pa);
257 if (s == 0) {
258 _kvm_err(kd, kd->program,
259 "_i386_vatop: 4MB page address not in dump");
260 goto invalid;
261 }
262 return (I386_NBPDR - offset);
263 }
264
265 pteindex = (va >> I386_PAGE_SHIFT) & (I386_NPTEPG - 1);
266 pte_pa = (pde & I386_PG_FRAME) + (pteindex * sizeof(pte));
267
268 s = _kvm_pa2off(kd, pte_pa, &ofs);
269 if (s < sizeof(pte)) {
270 _kvm_err(kd, kd->program, "_i386_vatop: pte_pa not found");
271 goto invalid;
272 }
273
274 /* XXX This has to be a physical address read, kvm_read is virtual */
275 if (pread(kd->pmfd, &pte, sizeof(pte), ofs) != sizeof(pte)) {
276 _kvm_syserr(kd, kd->program, "_i386_vatop: pread");
277 goto invalid;
278 }
279 pte = le32toh(pte);
280 if ((pte & I386_PG_V) == 0) {
281 _kvm_err(kd, kd->program, "_kvm_kvatop: pte not valid");
282 goto invalid;
283 }
284
285 a = (pte & I386_PG_FRAME) + offset;
286 s = _kvm_pa2off(kd, a, pa);
287 if (s == 0) {
288 _kvm_err(kd, kd->program, "_i386_vatop: address not in dump");
289 goto invalid;
290 } else
291 return (I386_PAGE_SIZE - offset);
292
293 invalid:
294 _kvm_err(kd, 0, "invalid address (0x%jx)", (uintmax_t)va);
295 return (0);
296 }
297
298 static int
_i386_vatop_pae(kvm_t * kd,kvaddr_t va,off_t * pa)299 _i386_vatop_pae(kvm_t *kd, kvaddr_t va, off_t *pa)
300 {
301 struct vmstate *vm;
302 i386_physaddr_pae_t offset;
303 i386_physaddr_pae_t pte_pa;
304 i386_pde_pae_t pde;
305 i386_pte_pae_t pte;
306 kvaddr_t pdeindex;
307 kvaddr_t pteindex;
308 size_t s;
309 i386_physaddr_pae_t a;
310 off_t ofs;
311 i386_pde_pae_t *PTD;
312
313 vm = kd->vmst;
314 PTD = (i386_pde_pae_t *)vm->PTD;
315 offset = va & I386_PAGE_MASK;
316
317 /*
318 * If we are initializing (kernel page table descriptor pointer
319 * not yet set) then return pa == va to avoid infinite recursion.
320 */
321 if (PTD == 0) {
322 s = _kvm_pa2off(kd, va, pa);
323 if (s == 0) {
324 _kvm_err(kd, kd->program,
325 "_i386_vatop_pae: bootstrap data not in dump");
326 goto invalid;
327 } else
328 return (I386_PAGE_SIZE - offset);
329 }
330
331 pdeindex = va >> I386_PDRSHIFT_PAE;
332 pde = le64toh(PTD[pdeindex]);
333 if ((pde & I386_PG_V) == 0) {
334 _kvm_err(kd, kd->program, "_kvm_kvatop_pae: pde not valid");
335 goto invalid;
336 }
337
338 if (pde & I386_PG_PS) {
339 /*
340 * No second-level page table; ptd describes one 2MB
341 * page. (We assume that the kernel wouldn't set
342 * PG_PS without enabling it cr0).
343 */
344 offset = va & I386_PAGE_PS_MASK_PAE;
345 a = (pde & I386_PG_PS_FRAME_PAE) + offset;
346 s = _kvm_pa2off(kd, a, pa);
347 if (s == 0) {
348 _kvm_err(kd, kd->program,
349 "_i386_vatop: 2MB page address not in dump");
350 goto invalid;
351 }
352 return (I386_NBPDR_PAE - offset);
353 }
354
355 pteindex = (va >> I386_PAGE_SHIFT) & (I386_NPTEPG_PAE - 1);
356 pte_pa = (pde & I386_PG_FRAME_PAE) + (pteindex * sizeof(pde));
357
358 s = _kvm_pa2off(kd, pte_pa, &ofs);
359 if (s < sizeof(pte)) {
360 _kvm_err(kd, kd->program, "_i386_vatop_pae: pdpe_pa not found");
361 goto invalid;
362 }
363
364 /* XXX This has to be a physical address read, kvm_read is virtual */
365 if (pread(kd->pmfd, &pte, sizeof(pte), ofs) != sizeof(pte)) {
366 _kvm_syserr(kd, kd->program, "_i386_vatop_pae: read");
367 goto invalid;
368 }
369 pte = le64toh(pte);
370 if ((pte & I386_PG_V) == 0) {
371 _kvm_err(kd, kd->program, "_i386_vatop_pae: pte not valid");
372 goto invalid;
373 }
374
375 a = (pte & I386_PG_FRAME_PAE) + offset;
376 s = _kvm_pa2off(kd, a, pa);
377 if (s == 0) {
378 _kvm_err(kd, kd->program,
379 "_i386_vatop_pae: address not in dump");
380 goto invalid;
381 } else
382 return (I386_PAGE_SIZE - offset);
383
384 invalid:
385 _kvm_err(kd, 0, "invalid address (0x%jx)", (uintmax_t)va);
386 return (0);
387 }
388
389 static int
_i386_kvatop(kvm_t * kd,kvaddr_t va,off_t * pa)390 _i386_kvatop(kvm_t *kd, kvaddr_t va, off_t *pa)
391 {
392
393 if (ISALIVE(kd)) {
394 _kvm_err(kd, 0, "vatop called in live kernel!");
395 return (0);
396 }
397 if (kd->vmst->pae)
398 return (_i386_vatop_pae(kd, va, pa));
399 else
400 return (_i386_vatop(kd, va, pa));
401 }
402
403 int
_i386_native(kvm_t * kd)404 _i386_native(kvm_t *kd)
405 {
406
407 #ifdef __i386__
408 return (1);
409 #else
410 return (0);
411 #endif
412 }
413
414 struct kvm_arch kvm_i386 = {
415 .ka_probe = _i386_probe,
416 .ka_initvtop = _i386_initvtop,
417 .ka_freevtop = _i386_freevtop,
418 .ka_kvatop = _i386_kvatop,
419 .ka_native = _i386_native,
420 };
421
422 KVM_ARCH(kvm_i386);
423