1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 2008, Juniper Networks, Inc.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the author nor the names of any co-contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
20 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
21 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
23 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
24 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
28 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 */
30
31 #include <sys/param.h>
32 #include <sys/endian.h>
33 #include <sys/kerneldump.h>
34 #include <sys/mman.h>
35
36 #include <elf.h>
37 #include <kvm.h>
38 #include <limits.h>
39 #include <stdlib.h>
40 #include <string.h>
41
42 #include "kvm_private.h"
43
44 struct vmstate {
45 void *map;
46 size_t mapsz;
47 size_t dmphdrsz;
48 Elf64_Ehdr *eh;
49 Elf64_Phdr *ph;
50 };
51
52 static int
valid_elf_header(kvm_t * kd,Elf64_Ehdr * eh)53 valid_elf_header(kvm_t *kd, Elf64_Ehdr *eh)
54 {
55
56 if (!IS_ELF(*eh))
57 return (0);
58 if (eh->e_ident[EI_CLASS] != ELFCLASS64)
59 return (0);
60 if (eh->e_ident[EI_DATA] != ELFDATA2MSB &&
61 eh->e_ident[EI_DATA] != ELFDATA2LSB)
62 return (0);
63 if (eh->e_ident[EI_VERSION] != EV_CURRENT)
64 return (0);
65 if (eh->e_ident[EI_OSABI] != ELFOSABI_STANDALONE)
66 return (0);
67 if (_kvm16toh(kd, eh->e_type) != ET_CORE)
68 return (0);
69 if (_kvm16toh(kd, eh->e_machine) != EM_PPC64)
70 return (0);
71 /* Can't think of anything else to check... */
72 return (1);
73 }
74
75 static size_t
dump_header_size(struct kerneldumpheader * dh)76 dump_header_size(struct kerneldumpheader *dh)
77 {
78
79 if (strcmp(dh->magic, KERNELDUMPMAGIC) != 0)
80 return (0);
81 if (strcmp(dh->architecture, "powerpc64") != 0 &&
82 strcmp(dh->architecture, "powerpc64le") != 0)
83 return (0);
84 /* That should do it... */
85 return (sizeof(*dh));
86 }
87
88 /*
89 * Map the ELF headers into the process' address space. We do this in two
90 * steps: first the ELF header itself and using that information the whole
91 * set of headers.
92 */
93 static int
powerpc_maphdrs(kvm_t * kd)94 powerpc_maphdrs(kvm_t *kd)
95 {
96 struct vmstate *vm;
97 size_t mapsz;
98
99 vm = kd->vmst;
100
101 vm->mapsz = sizeof(*vm->eh) + sizeof(struct kerneldumpheader);
102 vm->map = mmap(NULL, vm->mapsz, PROT_READ, MAP_PRIVATE, kd->pmfd, 0);
103 if (vm->map == MAP_FAILED) {
104 _kvm_err(kd, kd->program, "cannot map corefile");
105 return (-1);
106 }
107 vm->dmphdrsz = 0;
108 vm->eh = vm->map;
109 if (!valid_elf_header(kd, vm->eh)) {
110 /*
111 * Hmmm, no ELF header. Maybe we still have a dump header.
112 * This is normal when the core file wasn't created by
113 * savecore(8), but instead was dumped over TFTP. We can
114 * easily skip the dump header...
115 */
116 vm->dmphdrsz = dump_header_size(vm->map);
117 if (vm->dmphdrsz == 0)
118 goto inval;
119 vm->eh = (void *)((uintptr_t)vm->map + vm->dmphdrsz);
120 if (!valid_elf_header(kd, vm->eh))
121 goto inval;
122 }
123 mapsz = _kvm16toh(kd, vm->eh->e_phentsize) *
124 _kvm16toh(kd, vm->eh->e_phnum) + _kvm64toh(kd, vm->eh->e_phoff);
125 munmap(vm->map, vm->mapsz);
126
127 /* Map all headers. */
128 vm->mapsz = vm->dmphdrsz + mapsz;
129 vm->map = mmap(NULL, vm->mapsz, PROT_READ, MAP_PRIVATE, kd->pmfd, 0);
130 if (vm->map == MAP_FAILED) {
131 _kvm_err(kd, kd->program, "cannot map corefile headers");
132 return (-1);
133 }
134 vm->eh = (void *)((uintptr_t)vm->map + vm->dmphdrsz);
135 vm->ph = (void *)((uintptr_t)vm->eh +
136 (uintptr_t)_kvm64toh(kd, vm->eh->e_phoff));
137 return (0);
138
139 inval:
140 _kvm_err(kd, kd->program, "invalid corefile");
141 return (-1);
142 }
143
144 /*
145 * Determine the offset within the corefile corresponding the virtual
146 * address. Return the number of contiguous bytes in the corefile or
147 * 0 when the virtual address is invalid.
148 */
149 static size_t
powerpc64_va2off(kvm_t * kd,kvaddr_t va,off_t * ofs)150 powerpc64_va2off(kvm_t *kd, kvaddr_t va, off_t *ofs)
151 {
152 struct vmstate *vm = kd->vmst;
153 Elf64_Phdr *ph;
154 int nph;
155
156 ph = vm->ph;
157 nph = _kvm16toh(kd, vm->eh->e_phnum);
158 while (nph && (va < _kvm64toh(kd, ph->p_vaddr) ||
159 va >= _kvm64toh(kd, ph->p_vaddr) + _kvm64toh(kd, ph->p_memsz))) {
160 nph--;
161 ph = (void *)((uintptr_t)ph +
162 _kvm16toh(kd, vm->eh->e_phentsize));
163 }
164 if (nph == 0)
165 return (0);
166
167 /* Segment found. Return file offset and range. */
168 *ofs = vm->dmphdrsz + _kvm64toh(kd, ph->p_offset) +
169 (va - _kvm64toh(kd, ph->p_vaddr));
170 return (_kvm64toh(kd, ph->p_memsz) -
171 (va - _kvm64toh(kd, ph->p_vaddr)));
172 }
173
174 static void
_powerpc64_freevtop(kvm_t * kd)175 _powerpc64_freevtop(kvm_t *kd)
176 {
177 struct vmstate *vm = kd->vmst;
178
179 if (vm->eh != MAP_FAILED)
180 munmap(vm->eh, vm->mapsz);
181 free(vm);
182 kd->vmst = NULL;
183 }
184
185 static int
_powerpc64_probe(kvm_t * kd)186 _powerpc64_probe(kvm_t *kd)
187 {
188
189 return (_kvm_probe_elf_kernel(kd, ELFCLASS64, EM_PPC64) &&
190 kd->nlehdr.e_ident[EI_DATA] == ELFDATA2MSB);
191 }
192
193 static int
_powerpc64le_probe(kvm_t * kd)194 _powerpc64le_probe(kvm_t *kd)
195 {
196
197 return (_kvm_probe_elf_kernel(kd, ELFCLASS64, EM_PPC64) &&
198 kd->nlehdr.e_ident[EI_DATA] == ELFDATA2LSB);
199 }
200
201 static int
_powerpc64_initvtop(kvm_t * kd)202 _powerpc64_initvtop(kvm_t *kd)
203 {
204
205 kd->vmst = (struct vmstate *)_kvm_malloc(kd, sizeof(*kd->vmst));
206 if (kd->vmst == NULL)
207 return (-1);
208
209 if (powerpc_maphdrs(kd) == -1)
210 return (-1);
211
212 return (0);
213 }
214
215 static int
_powerpc64_kvatop(kvm_t * kd,kvaddr_t va,off_t * ofs)216 _powerpc64_kvatop(kvm_t *kd, kvaddr_t va, off_t *ofs)
217 {
218 struct vmstate *vm;
219
220 vm = kd->vmst;
221 if (_kvm64toh(kd, vm->ph->p_paddr) == 0xffffffffffffffff)
222 return ((int)powerpc64_va2off(kd, va, ofs));
223
224 _kvm_err(kd, kd->program, "Raw corefile not supported");
225 return (0);
226 }
227
228 static int
_powerpc64_native(kvm_t * kd __unused)229 _powerpc64_native(kvm_t *kd __unused)
230 {
231
232 #if defined(__powerpc64__) && BYTE_ORDER == BIG_ENDIAN
233 return (1);
234 #else
235 return (0);
236 #endif
237 }
238
239 static int
_powerpc64le_native(kvm_t * kd __unused)240 _powerpc64le_native(kvm_t *kd __unused)
241 {
242
243 #if defined(__powerpc64__) && BYTE_ORDER == LITTLE_ENDIAN
244 return (1);
245 #else
246 return (0);
247 #endif
248 }
249
250 static struct kvm_arch kvm_powerpc64 = {
251 .ka_probe = _powerpc64_probe,
252 .ka_initvtop = _powerpc64_initvtop,
253 .ka_freevtop = _powerpc64_freevtop,
254 .ka_kvatop = _powerpc64_kvatop,
255 .ka_native = _powerpc64_native,
256 };
257
258 static struct kvm_arch kvm_powerpc64le = {
259 .ka_probe = _powerpc64le_probe,
260 .ka_initvtop = _powerpc64_initvtop,
261 .ka_freevtop = _powerpc64_freevtop,
262 .ka_kvatop = _powerpc64_kvatop,
263 .ka_native = _powerpc64le_native,
264 };
265
266 KVM_ARCH(kvm_powerpc64);
267 KVM_ARCH(kvm_powerpc64le);
268