xref: /freebsd/lib/libkvm/kvm_minidump_amd64.c (revision c99bbcab5a5c2de91b55f36834214a5ee86c50cc)
1 /*-
2  * Copyright (c) 2006 Peter Wemm
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  * 1. Redistributions of source code must retain the above copyright
8  *    notice, this list of conditions and the following disclaimer.
9  * 2. Redistributions in binary form must reproduce the above copyright
10  *    notice, this list of conditions and the following disclaimer in the
11  *    documentation and/or other materials provided with the distribution.
12  *
13  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
14  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
17  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23  * SUCH DAMAGE.
24  */
25 
26 #include <sys/cdefs.h>
27 __FBSDID("$FreeBSD$");
28 
29 /*
30  * AMD64 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 <kvm.h>
40 
41 #include "../../sys/amd64/include/minidump.h"
42 
43 #include <limits.h>
44 
45 #include "kvm_private.h"
46 #include "kvm_amd64.h"
47 
48 #define	amd64_round_page(x)	roundup2((kvaddr_t)(x), AMD64_PAGE_SIZE)
49 
50 struct vmstate {
51 	struct minidumphdr hdr;
52 	struct hpt hpt;
53 	amd64_pte_t *page_map;
54 };
55 
56 static int
57 _amd64_minidump_probe(kvm_t *kd)
58 {
59 
60 	return (_kvm_probe_elf_kernel(kd, ELFCLASS64, EM_X86_64) &&
61 	    _kvm_is_minidump(kd));
62 }
63 
64 static void
65 _amd64_minidump_freevtop(kvm_t *kd)
66 {
67 	struct vmstate *vm = kd->vmst;
68 
69 	_kvm_hpt_free(&vm->hpt);
70 	if (vm->page_map)
71 		free(vm->page_map);
72 	free(vm);
73 	kd->vmst = NULL;
74 }
75 
76 static int
77 _amd64_minidump_initvtop(kvm_t *kd)
78 {
79 	struct vmstate *vmst;
80 	uint64_t *bitmap;
81 	off_t off;
82 
83 	vmst = _kvm_malloc(kd, sizeof(*vmst));
84 	if (vmst == 0) {
85 		_kvm_err(kd, kd->program, "cannot allocate vm");
86 		return (-1);
87 	}
88 	kd->vmst = vmst;
89 	if (pread(kd->pmfd, &vmst->hdr, sizeof(vmst->hdr), 0) !=
90 	    sizeof(vmst->hdr)) {
91 		_kvm_err(kd, kd->program, "cannot read dump header");
92 		return (-1);
93 	}
94 	if (strncmp(MINIDUMP_MAGIC, vmst->hdr.magic, sizeof(vmst->hdr.magic)) != 0) {
95 		_kvm_err(kd, kd->program, "not a minidump for this platform");
96 		return (-1);
97 	}
98 
99 	/*
100 	 * NB: amd64 minidump header is binary compatible between version 1
101 	 * and version 2; this may not be the case for the future versions.
102 	 */
103 	vmst->hdr.version = le32toh(vmst->hdr.version);
104 	if (vmst->hdr.version != MINIDUMP_VERSION && vmst->hdr.version != 1) {
105 		_kvm_err(kd, kd->program, "wrong minidump version. expected %d got %d",
106 		    MINIDUMP_VERSION, vmst->hdr.version);
107 		return (-1);
108 	}
109 	vmst->hdr.msgbufsize = le32toh(vmst->hdr.msgbufsize);
110 	vmst->hdr.bitmapsize = le32toh(vmst->hdr.bitmapsize);
111 	vmst->hdr.pmapsize = le32toh(vmst->hdr.pmapsize);
112 	vmst->hdr.kernbase = le64toh(vmst->hdr.kernbase);
113 	vmst->hdr.dmapbase = le64toh(vmst->hdr.dmapbase);
114 	vmst->hdr.dmapend = le64toh(vmst->hdr.dmapend);
115 
116 	/* Skip header and msgbuf */
117 	off = AMD64_PAGE_SIZE + amd64_round_page(vmst->hdr.msgbufsize);
118 
119 	bitmap = _kvm_malloc(kd, vmst->hdr.bitmapsize);
120 	if (bitmap == NULL) {
121 		_kvm_err(kd, kd->program, "cannot allocate %d bytes for bitmap", vmst->hdr.bitmapsize);
122 		return (-1);
123 	}
124 	if (pread(kd->pmfd, bitmap, vmst->hdr.bitmapsize, off) !=
125 	    (ssize_t)vmst->hdr.bitmapsize) {
126 		_kvm_err(kd, kd->program, "cannot read %d bytes for page bitmap", vmst->hdr.bitmapsize);
127 		free(bitmap);
128 		return (-1);
129 	}
130 	off += amd64_round_page(vmst->hdr.bitmapsize);
131 
132 	vmst->page_map = _kvm_malloc(kd, vmst->hdr.pmapsize);
133 	if (vmst->page_map == NULL) {
134 		_kvm_err(kd, kd->program, "cannot allocate %d bytes for page_map", vmst->hdr.pmapsize);
135 		free(bitmap);
136 		return (-1);
137 	}
138 	if (pread(kd->pmfd, vmst->page_map, vmst->hdr.pmapsize, off) !=
139 	    (ssize_t)vmst->hdr.pmapsize) {
140 		_kvm_err(kd, kd->program, "cannot read %d bytes for page_map", vmst->hdr.pmapsize);
141 		free(bitmap);
142 		return (-1);
143 	}
144 	off += vmst->hdr.pmapsize;
145 
146 	/* build physical address hash table for sparse pages */
147 	_kvm_hpt_init(kd, &vmst->hpt, bitmap, vmst->hdr.bitmapsize, off,
148 	    AMD64_PAGE_SIZE, sizeof(*bitmap));
149 	free(bitmap);
150 
151 	return (0);
152 }
153 
154 static int
155 _amd64_minidump_vatop_v1(kvm_t *kd, kvaddr_t va, off_t *pa)
156 {
157 	struct vmstate *vm;
158 	amd64_physaddr_t offset;
159 	amd64_pte_t pte;
160 	kvaddr_t pteindex;
161 	amd64_physaddr_t a;
162 	off_t ofs;
163 
164 	vm = kd->vmst;
165 	offset = va & AMD64_PAGE_MASK;
166 
167 	if (va >= vm->hdr.kernbase) {
168 		pteindex = (va - vm->hdr.kernbase) >> AMD64_PAGE_SHIFT;
169 		if (pteindex >= vm->hdr.pmapsize / sizeof(*vm->page_map))
170 			goto invalid;
171 		pte = le64toh(vm->page_map[pteindex]);
172 		if ((pte & AMD64_PG_V) == 0) {
173 			_kvm_err(kd, kd->program,
174 			    "_amd64_minidump_vatop_v1: pte not valid");
175 			goto invalid;
176 		}
177 		a = pte & AMD64_PG_FRAME;
178 		ofs = _kvm_hpt_find(&vm->hpt, a);
179 		if (ofs == -1) {
180 			_kvm_err(kd, kd->program,
181 	    "_amd64_minidump_vatop_v1: physical address 0x%jx not in minidump",
182 			    (uintmax_t)a);
183 			goto invalid;
184 		}
185 		*pa = ofs + offset;
186 		return (AMD64_PAGE_SIZE - offset);
187 	} else if (va >= vm->hdr.dmapbase && va < vm->hdr.dmapend) {
188 		a = (va - vm->hdr.dmapbase) & ~AMD64_PAGE_MASK;
189 		ofs = _kvm_hpt_find(&vm->hpt, a);
190 		if (ofs == -1) {
191 			_kvm_err(kd, kd->program,
192     "_amd64_minidump_vatop_v1: direct map address 0x%jx not in minidump",
193 			    (uintmax_t)va);
194 			goto invalid;
195 		}
196 		*pa = ofs + offset;
197 		return (AMD64_PAGE_SIZE - offset);
198 	} else {
199 		_kvm_err(kd, kd->program,
200 	    "_amd64_minidump_vatop_v1: virtual address 0x%jx not minidumped",
201 		    (uintmax_t)va);
202 		goto invalid;
203 	}
204 
205 invalid:
206 	_kvm_err(kd, 0, "invalid address (0x%jx)", (uintmax_t)va);
207 	return (0);
208 }
209 
210 static int
211 _amd64_minidump_vatop(kvm_t *kd, kvaddr_t va, off_t *pa)
212 {
213 	amd64_pte_t pt[AMD64_NPTEPG];
214 	struct vmstate *vm;
215 	amd64_physaddr_t offset;
216 	amd64_pde_t pde;
217 	amd64_pte_t pte;
218 	kvaddr_t pteindex;
219 	kvaddr_t pdeindex;
220 	amd64_physaddr_t a;
221 	off_t ofs;
222 
223 	vm = kd->vmst;
224 	offset = va & AMD64_PAGE_MASK;
225 
226 	if (va >= vm->hdr.kernbase) {
227 		pdeindex = (va - vm->hdr.kernbase) >> AMD64_PDRSHIFT;
228 		if (pdeindex >= vm->hdr.pmapsize / sizeof(*vm->page_map))
229 			goto invalid;
230 		pde = le64toh(vm->page_map[pdeindex]);
231 		if ((pde & AMD64_PG_V) == 0) {
232 			_kvm_err(kd, kd->program,
233 			    "_amd64_minidump_vatop: pde not valid");
234 			goto invalid;
235 		}
236 		if ((pde & AMD64_PG_PS) == 0) {
237 			a = pde & AMD64_PG_FRAME;
238 			ofs = _kvm_hpt_find(&vm->hpt, a);
239 			if (ofs == -1) {
240 				_kvm_err(kd, kd->program,
241 	    "_amd64_minidump_vatop: pt physical address 0x%jx not in minidump",
242 				    (uintmax_t)a);
243 				goto invalid;
244 			}
245 			/* TODO: Just read the single PTE */
246 			if (pread(kd->pmfd, &pt, AMD64_PAGE_SIZE, ofs) !=
247 			    AMD64_PAGE_SIZE) {
248 				_kvm_err(kd, kd->program,
249 				    "cannot read %d bytes for page table",
250 				    AMD64_PAGE_SIZE);
251 				return (-1);
252 			}
253 			pteindex = (va >> AMD64_PAGE_SHIFT) &
254 			    (AMD64_NPTEPG - 1);
255 			pte = le64toh(pt[pteindex]);
256 			if ((pte & AMD64_PG_V) == 0) {
257 				_kvm_err(kd, kd->program,
258 				    "_amd64_minidump_vatop: pte not valid");
259 				goto invalid;
260 			}
261 			a = pte & AMD64_PG_FRAME;
262 		} else {
263 			a = pde & AMD64_PG_PS_FRAME;
264 			a += (va & AMD64_PDRMASK) ^ offset;
265 		}
266 		ofs = _kvm_hpt_find(&vm->hpt, a);
267 		if (ofs == -1) {
268 			_kvm_err(kd, kd->program,
269 	    "_amd64_minidump_vatop: physical address 0x%jx not in minidump",
270 			    (uintmax_t)a);
271 			goto invalid;
272 		}
273 		*pa = ofs + offset;
274 		return (AMD64_PAGE_SIZE - offset);
275 	} else if (va >= vm->hdr.dmapbase && va < vm->hdr.dmapend) {
276 		a = (va - vm->hdr.dmapbase) & ~AMD64_PAGE_MASK;
277 		ofs = _kvm_hpt_find(&vm->hpt, a);
278 		if (ofs == -1) {
279 			_kvm_err(kd, kd->program,
280 	    "_amd64_minidump_vatop: direct map address 0x%jx not in minidump",
281 			    (uintmax_t)va);
282 			goto invalid;
283 		}
284 		*pa = ofs + offset;
285 		return (AMD64_PAGE_SIZE - offset);
286 	} else {
287 		_kvm_err(kd, kd->program,
288 	    "_amd64_minidump_vatop: virtual address 0x%jx not minidumped",
289 		    (uintmax_t)va);
290 		goto invalid;
291 	}
292 
293 invalid:
294 	_kvm_err(kd, 0, "invalid address (0x%jx)", (uintmax_t)va);
295 	return (0);
296 }
297 
298 static int
299 _amd64_minidump_kvatop(kvm_t *kd, kvaddr_t va, off_t *pa)
300 {
301 
302 	if (ISALIVE(kd)) {
303 		_kvm_err(kd, 0,
304 		    "_amd64_minidump_kvatop called in live kernel!");
305 		return (0);
306 	}
307 	if (((struct vmstate *)kd->vmst)->hdr.version == 1)
308 		return (_amd64_minidump_vatop_v1(kd, va, pa));
309 	else
310 		return (_amd64_minidump_vatop(kd, va, pa));
311 }
312 
313 struct kvm_arch kvm_amd64_minidump = {
314 	.ka_probe = _amd64_minidump_probe,
315 	.ka_initvtop = _amd64_minidump_initvtop,
316 	.ka_freevtop = _amd64_minidump_freevtop,
317 	.ka_kvatop = _amd64_minidump_kvatop,
318 	.ka_native = _amd64_native,
319 };
320 
321 KVM_ARCH(kvm_amd64_minidump);
322