xref: /freebsd/lib/libkvm/kvm_minidump_i386.c (revision 3fc36ee018bb836bd1796067cf4ef8683f166ebc)
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  * 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 <kvm.h>
40 
41 #include "../../sys/i386/include/minidump.h"
42 
43 #include <limits.h>
44 
45 #include "kvm_private.h"
46 #include "kvm_i386.h"
47 
48 #define	i386_round_page(x)	roundup2((kvaddr_t)(x), I386_PAGE_SIZE)
49 
50 struct vmstate {
51 	struct minidumphdr hdr;
52 	void *ptemap;
53 };
54 
55 static int
56 _i386_minidump_probe(kvm_t *kd)
57 {
58 
59 	return (_kvm_probe_elf_kernel(kd, ELFCLASS32, EM_386) &&
60 	    _kvm_is_minidump(kd));
61 }
62 
63 static void
64 _i386_minidump_freevtop(kvm_t *kd)
65 {
66 	struct vmstate *vm = kd->vmst;
67 
68 	free(vm->ptemap);
69 	free(vm);
70 	kd->vmst = NULL;
71 }
72 
73 static int
74 _i386_minidump_initvtop(kvm_t *kd)
75 {
76 	struct vmstate *vmst;
77 	off_t off, sparse_off;
78 
79 	vmst = _kvm_malloc(kd, sizeof(*vmst));
80 	if (vmst == NULL) {
81 		_kvm_err(kd, kd->program, "cannot allocate vm");
82 		return (-1);
83 	}
84 	kd->vmst = vmst;
85 	if (pread(kd->pmfd, &vmst->hdr, sizeof(vmst->hdr), 0) !=
86 	    sizeof(vmst->hdr)) {
87 		_kvm_err(kd, kd->program, "cannot read dump header");
88 		return (-1);
89 	}
90 	if (strncmp(MINIDUMP_MAGIC, vmst->hdr.magic, sizeof(vmst->hdr.magic)) != 0) {
91 		_kvm_err(kd, kd->program, "not a minidump for this platform");
92 		return (-1);
93 	}
94 	vmst->hdr.version = le32toh(vmst->hdr.version);
95 	if (vmst->hdr.version != MINIDUMP_VERSION) {
96 		_kvm_err(kd, kd->program, "wrong minidump version. expected %d got %d",
97 		    MINIDUMP_VERSION, vmst->hdr.version);
98 		return (-1);
99 	}
100 	vmst->hdr.msgbufsize = le32toh(vmst->hdr.msgbufsize);
101 	vmst->hdr.bitmapsize = le32toh(vmst->hdr.bitmapsize);
102 	vmst->hdr.ptesize = le32toh(vmst->hdr.ptesize);
103 	vmst->hdr.kernbase = le32toh(vmst->hdr.kernbase);
104 	vmst->hdr.paemode = le32toh(vmst->hdr.paemode);
105 
106 	/* Skip header and msgbuf */
107 	off = I386_PAGE_SIZE + i386_round_page(vmst->hdr.msgbufsize);
108 
109 	sparse_off = off + i386_round_page(vmst->hdr.bitmapsize) +
110 	    i386_round_page(vmst->hdr.ptesize);
111 	if (_kvm_pt_init(kd, vmst->hdr.bitmapsize, off, sparse_off,
112 	    I386_PAGE_SIZE, sizeof(uint32_t)) == -1) {
113 		_kvm_err(kd, kd->program, "cannot load core bitmap");
114 		return (-1);
115 	}
116 	off += i386_round_page(vmst->hdr.bitmapsize);
117 
118 	vmst->ptemap = _kvm_malloc(kd, vmst->hdr.ptesize);
119 	if (vmst->ptemap == NULL) {
120 		_kvm_err(kd, kd->program, "cannot allocate %d bytes for ptemap", vmst->hdr.ptesize);
121 		return (-1);
122 	}
123 	if (pread(kd->pmfd, vmst->ptemap, vmst->hdr.ptesize, off) !=
124 	    (ssize_t)vmst->hdr.ptesize) {
125 		_kvm_err(kd, kd->program, "cannot read %d bytes for ptemap", vmst->hdr.ptesize);
126 		return (-1);
127 	}
128 	off += i386_round_page(vmst->hdr.ptesize);
129 
130 	return (0);
131 }
132 
133 static int
134 _i386_minidump_vatop_pae(kvm_t *kd, kvaddr_t va, off_t *pa)
135 {
136 	struct vmstate *vm;
137 	i386_physaddr_pae_t offset;
138 	i386_pte_pae_t pte;
139 	kvaddr_t pteindex;
140 	i386_physaddr_pae_t a;
141 	off_t ofs;
142 	i386_pte_pae_t *ptemap;
143 
144 	vm = kd->vmst;
145 	ptemap = vm->ptemap;
146 	offset = va & I386_PAGE_MASK;
147 
148 	if (va >= vm->hdr.kernbase) {
149 		pteindex = (va - vm->hdr.kernbase) >> I386_PAGE_SHIFT;
150 		if (pteindex >= vm->hdr.ptesize / sizeof(*ptemap))
151 			goto invalid;
152 		pte = le64toh(ptemap[pteindex]);
153 		if ((pte & I386_PG_V) == 0) {
154 			_kvm_err(kd, kd->program,
155 			    "_i386_minidump_vatop_pae: pte not valid");
156 			goto invalid;
157 		}
158 		a = pte & I386_PG_FRAME_PAE;
159 		ofs = _kvm_pt_find(kd, a);
160 		if (ofs == -1) {
161 			_kvm_err(kd, kd->program,
162 	    "_i386_minidump_vatop_pae: physical address 0x%jx not in minidump",
163 			    (uintmax_t)a);
164 			goto invalid;
165 		}
166 		*pa = ofs + offset;
167 		return (I386_PAGE_SIZE - offset);
168 	} else {
169 		_kvm_err(kd, kd->program,
170 	    "_i386_minidump_vatop_pae: virtual address 0x%jx not minidumped",
171 		    (uintmax_t)va);
172 		goto invalid;
173 	}
174 
175 invalid:
176 	_kvm_err(kd, 0, "invalid address (0x%jx)", (uintmax_t)va);
177 	return (0);
178 }
179 
180 static int
181 _i386_minidump_vatop(kvm_t *kd, kvaddr_t va, off_t *pa)
182 {
183 	struct vmstate *vm;
184 	i386_physaddr_t offset;
185 	i386_pte_t pte;
186 	kvaddr_t pteindex;
187 	i386_physaddr_t a;
188 	off_t ofs;
189 	i386_pte_t *ptemap;
190 
191 	vm = kd->vmst;
192 	ptemap = vm->ptemap;
193 	offset = va & I386_PAGE_MASK;
194 
195 	if (va >= vm->hdr.kernbase) {
196 		pteindex = (va - vm->hdr.kernbase) >> I386_PAGE_SHIFT;
197 		if (pteindex >= vm->hdr.ptesize / sizeof(*ptemap))
198 			goto invalid;
199 		pte = le32toh(ptemap[pteindex]);
200 		if ((pte & I386_PG_V) == 0) {
201 			_kvm_err(kd, kd->program,
202 			    "_i386_minidump_vatop: pte not valid");
203 			goto invalid;
204 		}
205 		a = pte & I386_PG_FRAME;
206 		ofs = _kvm_pt_find(kd, a);
207 		if (ofs == -1) {
208 			_kvm_err(kd, kd->program,
209 	    "_i386_minidump_vatop: physical address 0x%jx not in minidump",
210 			    (uintmax_t)a);
211 			goto invalid;
212 		}
213 		*pa = ofs + offset;
214 		return (I386_PAGE_SIZE - offset);
215 	} else {
216 		_kvm_err(kd, kd->program,
217 	    "_i386_minidump_vatop: virtual address 0x%jx not minidumped",
218 		    (uintmax_t)va);
219 		goto invalid;
220 	}
221 
222 invalid:
223 	_kvm_err(kd, 0, "invalid address (0x%jx)", (uintmax_t)va);
224 	return (0);
225 }
226 
227 static int
228 _i386_minidump_kvatop(kvm_t *kd, kvaddr_t va, off_t *pa)
229 {
230 
231 	if (ISALIVE(kd)) {
232 		_kvm_err(kd, 0, "_i386_minidump_kvatop called in live kernel!");
233 		return (0);
234 	}
235 	if (kd->vmst->hdr.paemode)
236 		return (_i386_minidump_vatop_pae(kd, va, pa));
237 	else
238 		return (_i386_minidump_vatop(kd, va, pa));
239 }
240 
241 struct kvm_arch kvm_i386_minidump = {
242 	.ka_probe = _i386_minidump_probe,
243 	.ka_initvtop = _i386_minidump_initvtop,
244 	.ka_freevtop = _i386_minidump_freevtop,
245 	.ka_kvatop = _i386_minidump_kvatop,
246 	.ka_native = _i386_native,
247 };
248 
249 KVM_ARCH(kvm_i386_minidump);
250