xref: /freebsd/lib/libkvm/kvm_amd64.c (revision 5f4c09dd85bff675e0ca63c55ea3c517e0fddfcc)
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 #include <sys/cdefs.h>
37 __SCCSID("@(#)kvm_hp300.c	8.1 (Berkeley) 6/4/93");
38 
39 /*
40  * AMD64 machine dependent routines for kvm.  Hopefully, the forthcoming
41  * vm code will one day obsolete this module.
42  */
43 
44 #include <sys/param.h>
45 #include <sys/endian.h>
46 #include <stdint.h>
47 #include <stdlib.h>
48 #include <string.h>
49 #include <unistd.h>
50 #include <vm/vm.h>
51 #include <kvm.h>
52 
53 #include <limits.h>
54 
55 #include "kvm_private.h"
56 #include "kvm_amd64.h"
57 
58 struct vmstate {
59 	size_t		phnum;
60 	GElf_Phdr	*phdr;
61 	amd64_pml4e_t	*PML4;
62 };
63 
64 /*
65  * Translate a physical memory address to a file-offset in the crash-dump.
66  */
67 static size_t
68 _kvm_pa2off(kvm_t *kd, uint64_t pa, off_t *ofs)
69 {
70 	struct vmstate *vm = kd->vmst;
71 	GElf_Phdr *p;
72 	size_t n;
73 
74 	if (kd->rawdump) {
75 		*ofs = pa;
76 		return (AMD64_PAGE_SIZE - (pa & AMD64_PAGE_MASK));
77 	}
78 
79 	p = vm->phdr;
80 	n = vm->phnum;
81 	while (n && (pa < p->p_paddr || pa >= p->p_paddr + p->p_memsz))
82 		p++, n--;
83 	if (n == 0)
84 		return (0);
85 	*ofs = (pa - p->p_paddr) + p->p_offset;
86 	return (AMD64_PAGE_SIZE - (pa & AMD64_PAGE_MASK));
87 }
88 
89 static void
90 _amd64_freevtop(kvm_t *kd)
91 {
92 	struct vmstate *vm = kd->vmst;
93 
94 	if (vm->PML4)
95 		free(vm->PML4);
96 	free(vm->phdr);
97 	free(vm);
98 	kd->vmst = NULL;
99 }
100 
101 static int
102 _amd64_probe(kvm_t *kd)
103 {
104 
105 	return (_kvm_probe_elf_kernel(kd, ELFCLASS64, EM_X86_64) &&
106 	    !_kvm_is_minidump(kd));
107 }
108 
109 static int
110 _amd64_initvtop(kvm_t *kd)
111 {
112 	struct kvm_nlist nl[2];
113 	amd64_physaddr_t pa;
114 	kvaddr_t kernbase;
115 	amd64_pml4e_t *PML4;
116 
117 	kd->vmst = (struct vmstate *)_kvm_malloc(kd, sizeof(*kd->vmst));
118 	if (kd->vmst == NULL) {
119 		_kvm_err(kd, kd->program, "cannot allocate vm");
120 		return (-1);
121 	}
122 	kd->vmst->PML4 = 0;
123 
124 	if (kd->rawdump == 0) {
125 		if (_kvm_read_core_phdrs(kd, &kd->vmst->phnum,
126 		    &kd->vmst->phdr) == -1)
127 			return (-1);
128 	}
129 
130 	nl[0].n_name = "kernbase";
131 	nl[1].n_name = 0;
132 
133 	if (kvm_nlist2(kd, nl) != 0) {
134 		_kvm_err(kd, kd->program, "bad namelist - no kernbase");
135 		return (-1);
136 	}
137 	kernbase = nl[0].n_value;
138 
139 	nl[0].n_name = "KPML4phys";
140 	nl[1].n_name = 0;
141 
142 	if (kvm_nlist2(kd, nl) != 0) {
143 		_kvm_err(kd, kd->program, "bad namelist - no KPML4phys");
144 		return (-1);
145 	}
146 	if (kvm_read2(kd, (nl[0].n_value - kernbase), &pa, sizeof(pa)) !=
147 	    sizeof(pa)) {
148 		_kvm_err(kd, kd->program, "cannot read KPML4phys");
149 		return (-1);
150 	}
151 	pa = le64toh(pa);
152 	PML4 = _kvm_malloc(kd, AMD64_PAGE_SIZE);
153 	if (PML4 == NULL) {
154 		_kvm_err(kd, kd->program, "cannot allocate PML4");
155 		return (-1);
156 	}
157 	if (kvm_read2(kd, pa, PML4, AMD64_PAGE_SIZE) != AMD64_PAGE_SIZE) {
158 		_kvm_err(kd, kd->program, "cannot read KPML4phys");
159 		free(PML4);
160 		return (-1);
161 	}
162 	kd->vmst->PML4 = PML4;
163 	return (0);
164 }
165 
166 static int
167 _amd64_vatop(kvm_t *kd, kvaddr_t va, off_t *pa)
168 {
169 	struct vmstate *vm;
170 	amd64_physaddr_t offset;
171 	amd64_physaddr_t pdpe_pa;
172 	amd64_physaddr_t pde_pa;
173 	amd64_physaddr_t pte_pa;
174 	amd64_pml4e_t pml4e;
175 	amd64_pdpe_t pdpe;
176 	amd64_pde_t pde;
177 	amd64_pte_t pte;
178 	kvaddr_t pml4eindex;
179 	kvaddr_t pdpeindex;
180 	kvaddr_t pdeindex;
181 	kvaddr_t pteindex;
182 	amd64_physaddr_t a;
183 	off_t ofs;
184 	size_t s;
185 
186 	vm = kd->vmst;
187 	offset = va & AMD64_PAGE_MASK;
188 
189 	/*
190 	 * If we are initializing (kernel page table descriptor pointer
191 	 * not yet set) then return pa == va to avoid infinite recursion.
192 	 */
193 	if (vm->PML4 == NULL) {
194 		s = _kvm_pa2off(kd, va, pa);
195 		if (s == 0) {
196 			_kvm_err(kd, kd->program,
197 			    "_amd64_vatop: bootstrap data not in dump");
198 			goto invalid;
199 		} else
200 			return (AMD64_PAGE_SIZE - offset);
201 	}
202 
203 	pml4eindex = (va >> AMD64_PML4SHIFT) & (AMD64_NPML4EPG - 1);
204 	pml4e = le64toh(vm->PML4[pml4eindex]);
205 	if ((pml4e & AMD64_PG_V) == 0) {
206 		_kvm_err(kd, kd->program, "_amd64_vatop: pml4e not valid");
207 		goto invalid;
208 	}
209 
210 	pdpeindex = (va >> AMD64_PDPSHIFT) & (AMD64_NPDPEPG - 1);
211 	pdpe_pa = (pml4e & AMD64_PG_FRAME) + (pdpeindex * sizeof(amd64_pdpe_t));
212 
213 	s = _kvm_pa2off(kd, pdpe_pa, &ofs);
214 	if (s < sizeof(pdpe)) {
215 		_kvm_err(kd, kd->program, "_amd64_vatop: pdpe_pa not found");
216 		goto invalid;
217 	}
218 	if (pread(kd->pmfd, &pdpe, sizeof(pdpe), ofs) != sizeof(pdpe)) {
219 		_kvm_syserr(kd, kd->program, "_amd64_vatop: read pdpe");
220 		goto invalid;
221 	}
222 	pdpe = le64toh(pdpe);
223 	if ((pdpe & AMD64_PG_V) == 0) {
224 		_kvm_err(kd, kd->program, "_amd64_vatop: pdpe not valid");
225 		goto invalid;
226 	}
227 
228 	if (pdpe & AMD64_PG_PS) {
229 		/*
230 		 * No next-level page table; pdpe describes one 1GB page.
231 		 */
232 		a = (pdpe & AMD64_PG_1GB_FRAME) + (va & AMD64_PDPMASK);
233 		s = _kvm_pa2off(kd, a, pa);
234 		if (s == 0) {
235 			_kvm_err(kd, kd->program,
236 			    "_amd64_vatop: 1GB page address not in dump");
237 			goto invalid;
238 		} else
239 			return (AMD64_NBPDP - (va & AMD64_PDPMASK));
240 	}
241 
242 	pdeindex = (va >> AMD64_PDRSHIFT) & (AMD64_NPDEPG - 1);
243 	pde_pa = (pdpe & AMD64_PG_FRAME) + (pdeindex * sizeof(amd64_pde_t));
244 
245 	s = _kvm_pa2off(kd, pde_pa, &ofs);
246 	if (s < sizeof(pde)) {
247 		_kvm_syserr(kd, kd->program, "_amd64_vatop: pde_pa not found");
248 		goto invalid;
249 	}
250 	if (pread(kd->pmfd, &pde, sizeof(pde), ofs) != sizeof(pde)) {
251 		_kvm_syserr(kd, kd->program, "_amd64_vatop: read pde");
252 		goto invalid;
253 	}
254 	pde = le64toh(pde);
255 	if ((pde & AMD64_PG_V) == 0) {
256 		_kvm_err(kd, kd->program, "_amd64_vatop: pde not valid");
257 		goto invalid;
258 	}
259 
260 	if (pde & AMD64_PG_PS) {
261 		/*
262 		 * No final-level page table; pde describes one 2MB page.
263 		 */
264 		a = (pde & AMD64_PG_PS_FRAME) + (va & AMD64_PDRMASK);
265 		s = _kvm_pa2off(kd, a, pa);
266 		if (s == 0) {
267 			_kvm_err(kd, kd->program,
268 			    "_amd64_vatop: 2MB page address not in dump");
269 			goto invalid;
270 		} else
271 			return (AMD64_NBPDR - (va & AMD64_PDRMASK));
272 	}
273 
274 	pteindex = (va >> AMD64_PAGE_SHIFT) & (AMD64_NPTEPG - 1);
275 	pte_pa = (pde & AMD64_PG_FRAME) + (pteindex * sizeof(amd64_pte_t));
276 
277 	s = _kvm_pa2off(kd, pte_pa, &ofs);
278 	if (s < sizeof(pte)) {
279 		_kvm_err(kd, kd->program, "_amd64_vatop: pte_pa not found");
280 		goto invalid;
281 	}
282 	if (pread(kd->pmfd, &pte, sizeof(pte), ofs) != sizeof(pte)) {
283 		_kvm_syserr(kd, kd->program, "_amd64_vatop: read");
284 		goto invalid;
285 	}
286 	if ((pte & AMD64_PG_V) == 0) {
287 		_kvm_err(kd, kd->program, "_amd64_vatop: pte not valid");
288 		goto invalid;
289 	}
290 
291 	a = (pte & AMD64_PG_FRAME) + offset;
292 	s = _kvm_pa2off(kd, a, pa);
293 	if (s == 0) {
294 		_kvm_err(kd, kd->program, "_amd64_vatop: address not in dump");
295 		goto invalid;
296 	} else
297 		return (AMD64_PAGE_SIZE - offset);
298 
299 invalid:
300 	_kvm_err(kd, 0, "invalid address (0x%jx)", (uintmax_t)va);
301 	return (0);
302 }
303 
304 static int
305 _amd64_kvatop(kvm_t *kd, kvaddr_t va, off_t *pa)
306 {
307 
308 	if (ISALIVE(kd)) {
309 		_kvm_err(kd, 0, "kvm_kvatop called in live kernel!");
310 		return (0);
311 	}
312 	return (_amd64_vatop(kd, va, pa));
313 }
314 
315 int
316 _amd64_native(kvm_t *kd __unused)
317 {
318 
319 #ifdef __amd64__
320 	return (1);
321 #else
322 	return (0);
323 #endif
324 }
325 
326 static struct kvm_arch kvm_amd64 = {
327 	.ka_probe = _amd64_probe,
328 	.ka_initvtop = _amd64_initvtop,
329 	.ka_freevtop = _amd64_freevtop,
330 	.ka_kvatop = _amd64_kvatop,
331 	.ka_native = _amd64_native,
332 };
333 
334 KVM_ARCH(kvm_amd64);
335