1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2006 Peter Wemm
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 */
27
28 #include <sys/cdefs.h>
29 /*
30 * i386 machine dependent routines for kvm and minidumps.
31 */
32
33 #include <sys/param.h>
34 #include <sys/endian.h>
35 #include <stdint.h>
36 #include <stdlib.h>
37 #include <string.h>
38 #include <unistd.h>
39 #include <vm/vm.h>
40 #include <kvm.h>
41
42 #include "../../sys/i386/include/minidump.h"
43
44 #include <limits.h>
45
46 #include "kvm_private.h"
47 #include "kvm_i386.h"
48
49 #define i386_round_page(x) roundup2((kvaddr_t)(x), I386_PAGE_SIZE)
50
51 struct vmstate {
52 struct minidumphdr hdr;
53 };
54
55 static i386_pte_pae_t
_i386_pte_pae_get(kvm_t * kd,u_long pteindex)56 _i386_pte_pae_get(kvm_t *kd, u_long pteindex)
57 {
58 i386_pte_pae_t *pte = _kvm_pmap_get(kd, pteindex, sizeof(*pte));
59
60 return le64toh(*pte);
61 }
62
63 static i386_pte_t
_i386_pte_get(kvm_t * kd,u_long pteindex)64 _i386_pte_get(kvm_t *kd, u_long pteindex)
65 {
66 i386_pte_t *pte = _kvm_pmap_get(kd, pteindex, sizeof(*pte));
67
68 return le32toh(*pte);
69 }
70
71 static int
_i386_minidump_probe(kvm_t * kd)72 _i386_minidump_probe(kvm_t *kd)
73 {
74
75 return (_kvm_probe_elf_kernel(kd, ELFCLASS32, EM_386) &&
76 _kvm_is_minidump(kd));
77 }
78
79 static void
_i386_minidump_freevtop(kvm_t * kd)80 _i386_minidump_freevtop(kvm_t *kd)
81 {
82 struct vmstate *vm = kd->vmst;
83
84 free(vm);
85 kd->vmst = NULL;
86 }
87
88 static int
_i386_minidump_initvtop(kvm_t * kd)89 _i386_minidump_initvtop(kvm_t *kd)
90 {
91 struct vmstate *vmst;
92 off_t off, dump_avail_off, sparse_off;
93
94 vmst = _kvm_malloc(kd, sizeof(*vmst));
95 if (vmst == NULL) {
96 _kvm_err(kd, kd->program, "cannot allocate vm");
97 return (-1);
98 }
99 kd->vmst = vmst;
100 if (pread(kd->pmfd, &vmst->hdr, sizeof(vmst->hdr), 0) !=
101 sizeof(vmst->hdr)) {
102 _kvm_err(kd, kd->program, "cannot read dump header");
103 return (-1);
104 }
105 if (strncmp(MINIDUMP_MAGIC, vmst->hdr.magic, sizeof(vmst->hdr.magic)) != 0) {
106 _kvm_err(kd, kd->program, "not a minidump for this platform");
107 return (-1);
108 }
109 vmst->hdr.version = le32toh(vmst->hdr.version);
110 if (vmst->hdr.version != MINIDUMP_VERSION && vmst->hdr.version != 1) {
111 _kvm_err(kd, kd->program, "wrong minidump version. expected %d got %d",
112 MINIDUMP_VERSION, vmst->hdr.version);
113 return (-1);
114 }
115 vmst->hdr.msgbufsize = le32toh(vmst->hdr.msgbufsize);
116 vmst->hdr.bitmapsize = le32toh(vmst->hdr.bitmapsize);
117 vmst->hdr.ptesize = le32toh(vmst->hdr.ptesize);
118 vmst->hdr.kernbase = le32toh(vmst->hdr.kernbase);
119 vmst->hdr.paemode = le32toh(vmst->hdr.paemode);
120 vmst->hdr.dumpavailsize = vmst->hdr.version == MINIDUMP_VERSION ?
121 le32toh(vmst->hdr.dumpavailsize) : 0;
122
123 /* Skip header and msgbuf */
124 dump_avail_off = I386_PAGE_SIZE + i386_round_page(vmst->hdr.msgbufsize);
125
126 /* Skip dump_avail */
127 off = dump_avail_off + i386_round_page(vmst->hdr.dumpavailsize);
128
129 sparse_off = off + i386_round_page(vmst->hdr.bitmapsize) +
130 i386_round_page(vmst->hdr.ptesize);
131 if (_kvm_pt_init(kd, vmst->hdr.dumpavailsize, dump_avail_off,
132 vmst->hdr.bitmapsize, off, sparse_off, I386_PAGE_SIZE) == -1) {
133 return (-1);
134 }
135 off += i386_round_page(vmst->hdr.bitmapsize);
136
137 if (_kvm_pmap_init(kd, vmst->hdr.ptesize, off) == -1) {
138 return (-1);
139 }
140 off += i386_round_page(vmst->hdr.ptesize);
141
142 return (0);
143 }
144
145 static int
_i386_minidump_vatop_pae(kvm_t * kd,kvaddr_t va,off_t * pa)146 _i386_minidump_vatop_pae(kvm_t *kd, kvaddr_t va, off_t *pa)
147 {
148 struct vmstate *vm;
149 i386_physaddr_pae_t offset;
150 i386_pte_pae_t pte;
151 kvaddr_t pteindex;
152 i386_physaddr_pae_t a;
153 off_t ofs;
154
155 vm = kd->vmst;
156 offset = va & I386_PAGE_MASK;
157
158 if (va >= vm->hdr.kernbase) {
159 pteindex = (va - vm->hdr.kernbase) >> I386_PAGE_SHIFT;
160 if (pteindex >= vm->hdr.ptesize / sizeof(pte))
161 goto invalid;
162 pte = _i386_pte_pae_get(kd, pteindex);
163 if ((pte & I386_PG_V) == 0) {
164 _kvm_err(kd, kd->program,
165 "_i386_minidump_vatop_pae: pte not valid");
166 goto invalid;
167 }
168 a = pte & I386_PG_FRAME_PAE;
169 ofs = _kvm_pt_find(kd, a, I386_PAGE_SIZE);
170 if (ofs == -1) {
171 _kvm_err(kd, kd->program,
172 "_i386_minidump_vatop_pae: physical address 0x%jx not in minidump",
173 (uintmax_t)a);
174 goto invalid;
175 }
176 *pa = ofs + offset;
177 return (I386_PAGE_SIZE - offset);
178 } else {
179 _kvm_err(kd, kd->program,
180 "_i386_minidump_vatop_pae: virtual address 0x%jx not minidumped",
181 (uintmax_t)va);
182 goto invalid;
183 }
184
185 invalid:
186 _kvm_err(kd, 0, "invalid address (0x%jx)", (uintmax_t)va);
187 return (0);
188 }
189
190 static int
_i386_minidump_vatop(kvm_t * kd,kvaddr_t va,off_t * pa)191 _i386_minidump_vatop(kvm_t *kd, kvaddr_t va, off_t *pa)
192 {
193 struct vmstate *vm;
194 i386_physaddr_t offset;
195 i386_pte_t pte;
196 kvaddr_t pteindex;
197 i386_physaddr_t a;
198 off_t ofs;
199
200 vm = kd->vmst;
201 offset = va & I386_PAGE_MASK;
202
203 if (va >= vm->hdr.kernbase) {
204 pteindex = (va - vm->hdr.kernbase) >> I386_PAGE_SHIFT;
205 if (pteindex >= vm->hdr.ptesize / sizeof(pte))
206 goto invalid;
207 pte = _i386_pte_get(kd, pteindex);
208 if ((pte & I386_PG_V) == 0) {
209 _kvm_err(kd, kd->program,
210 "_i386_minidump_vatop: pte not valid");
211 goto invalid;
212 }
213 a = pte & I386_PG_FRAME;
214 ofs = _kvm_pt_find(kd, a, I386_PAGE_SIZE);
215 if (ofs == -1) {
216 _kvm_err(kd, kd->program,
217 "_i386_minidump_vatop: physical address 0x%jx not in minidump",
218 (uintmax_t)a);
219 goto invalid;
220 }
221 *pa = ofs + offset;
222 return (I386_PAGE_SIZE - offset);
223 } else {
224 _kvm_err(kd, kd->program,
225 "_i386_minidump_vatop: virtual address 0x%jx not minidumped",
226 (uintmax_t)va);
227 goto invalid;
228 }
229
230 invalid:
231 _kvm_err(kd, 0, "invalid address (0x%jx)", (uintmax_t)va);
232 return (0);
233 }
234
235 static int
_i386_minidump_kvatop(kvm_t * kd,kvaddr_t va,off_t * pa)236 _i386_minidump_kvatop(kvm_t *kd, kvaddr_t va, off_t *pa)
237 {
238
239 if (ISALIVE(kd)) {
240 _kvm_err(kd, 0, "_i386_minidump_kvatop called in live kernel!");
241 return (0);
242 }
243 if (kd->vmst->hdr.paemode)
244 return (_i386_minidump_vatop_pae(kd, va, pa));
245 else
246 return (_i386_minidump_vatop(kd, va, pa));
247 }
248
249 static vm_prot_t
_i386_entry_to_prot(uint64_t pte)250 _i386_entry_to_prot(uint64_t pte)
251 {
252 vm_prot_t prot = VM_PROT_READ;
253
254 /* Source: i386/pmap.c:pmap_protect() */
255 if (pte & I386_PG_RW)
256 prot |= VM_PROT_WRITE;
257 if ((pte & I386_PG_NX) == 0)
258 prot |= VM_PROT_EXECUTE;
259
260 return prot;
261 }
262
263 struct i386_iter {
264 kvm_t *kd;
265 u_long nptes;
266 u_long pteindex;
267 };
268
269 static void
_i386_iterator_init(struct i386_iter * it,kvm_t * kd)270 _i386_iterator_init(struct i386_iter *it, kvm_t *kd)
271 {
272 struct vmstate *vm = kd->vmst;
273
274 it->kd = kd;
275 it->pteindex = 0;
276 if (vm->hdr.paemode) {
277 it->nptes = vm->hdr.ptesize / sizeof(i386_pte_pae_t);
278 } else {
279 it->nptes = vm->hdr.ptesize / sizeof(i386_pte_t);
280 }
281 return;
282 }
283
284 static int
_i386_iterator_next(struct i386_iter * it,u_long * pa,u_long * va,u_long * dva,vm_prot_t * prot)285 _i386_iterator_next(struct i386_iter *it, u_long *pa, u_long *va, u_long *dva,
286 vm_prot_t *prot)
287 {
288 struct vmstate *vm = it->kd->vmst;
289 i386_pte_t pte32;
290 i386_pte_pae_t pte64;
291 int found = 0;
292
293 *dva = 0;
294 *pa = 0;
295 *va = 0;
296 *dva = 0;
297 *prot = 0;
298 for (; it->pteindex < it->nptes && found == 0; it->pteindex++) {
299 if (vm->hdr.paemode) {
300 pte64 = _i386_pte_pae_get(it->kd, it->pteindex);
301 if ((pte64 & I386_PG_V) == 0)
302 continue;
303 *prot = _i386_entry_to_prot(pte64);
304 *pa = pte64 & I386_PG_FRAME_PAE;
305 } else {
306 pte32 = _i386_pte_get(it->kd, it->pteindex);
307 if ((pte32 & I386_PG_V) == 0)
308 continue;
309 *prot = _i386_entry_to_prot(pte32);
310 *pa = pte32 & I386_PG_FRAME;
311 }
312 *va = vm->hdr.kernbase + (it->pteindex << I386_PAGE_SHIFT);
313 found = 1;
314 }
315 return found;
316 }
317
318 static int
_i386_minidump_walk_pages(kvm_t * kd,kvm_walk_pages_cb_t * cb,void * arg)319 _i386_minidump_walk_pages(kvm_t *kd, kvm_walk_pages_cb_t *cb, void *arg)
320 {
321 struct i386_iter it;
322 u_long dva, pa, va;
323 vm_prot_t prot;
324
325 _i386_iterator_init(&it, kd);
326 while (_i386_iterator_next(&it, &pa, &va, &dva, &prot)) {
327 if (!_kvm_visit_cb(kd, cb, arg, pa, va, dva,
328 prot, I386_PAGE_SIZE, 0)) {
329 return (0);
330 }
331 }
332 return (1);
333 }
334
335 static struct kvm_arch kvm_i386_minidump = {
336 .ka_probe = _i386_minidump_probe,
337 .ka_initvtop = _i386_minidump_initvtop,
338 .ka_freevtop = _i386_minidump_freevtop,
339 .ka_kvatop = _i386_minidump_kvatop,
340 .ka_native = _i386_native,
341 .ka_walk_pages = _i386_minidump_walk_pages,
342 };
343
344 KVM_ARCH(kvm_i386_minidump);
345