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/cdefs.h>
32 #include <sys/param.h>
33 #include <sys/endian.h>
34 #include <sys/kerneldump.h>
35 #include <sys/mman.h>
36
37 #include <elf.h>
38 #include <kvm.h>
39 #include <limits.h>
40 #include <stdlib.h>
41 #include <string.h>
42
43 #include "kvm_private.h"
44
45 struct vmstate {
46 void *map;
47 size_t mapsz;
48 size_t dmphdrsz;
49 Elf64_Ehdr *eh;
50 Elf64_Phdr *ph;
51 };
52
53 static int
valid_elf_header(kvm_t * kd,Elf64_Ehdr * eh)54 valid_elf_header(kvm_t *kd, Elf64_Ehdr *eh)
55 {
56
57 if (!IS_ELF(*eh))
58 return (0);
59 if (eh->e_ident[EI_CLASS] != ELFCLASS64)
60 return (0);
61 if (eh->e_ident[EI_DATA] != ELFDATA2MSB &&
62 eh->e_ident[EI_DATA] != ELFDATA2LSB)
63 return (0);
64 if (eh->e_ident[EI_VERSION] != EV_CURRENT)
65 return (0);
66 if (eh->e_ident[EI_OSABI] != ELFOSABI_STANDALONE)
67 return (0);
68 if (_kvm16toh(kd, eh->e_type) != ET_CORE)
69 return (0);
70 if (_kvm16toh(kd, eh->e_machine) != EM_PPC64)
71 return (0);
72 /* Can't think of anything else to check... */
73 return (1);
74 }
75
76 static size_t
dump_header_size(struct kerneldumpheader * dh)77 dump_header_size(struct kerneldumpheader *dh)
78 {
79
80 if (strcmp(dh->magic, KERNELDUMPMAGIC) != 0)
81 return (0);
82 if (strcmp(dh->architecture, "powerpc64") != 0 &&
83 strcmp(dh->architecture, "powerpc64le") != 0)
84 return (0);
85 /* That should do it... */
86 return (sizeof(*dh));
87 }
88
89 /*
90 * Map the ELF headers into the process' address space. We do this in two
91 * steps: first the ELF header itself and using that information the whole
92 * set of headers.
93 */
94 static int
powerpc_maphdrs(kvm_t * kd)95 powerpc_maphdrs(kvm_t *kd)
96 {
97 struct vmstate *vm;
98 size_t mapsz;
99
100 vm = kd->vmst;
101
102 vm->mapsz = sizeof(*vm->eh) + sizeof(struct kerneldumpheader);
103 vm->map = mmap(NULL, vm->mapsz, PROT_READ, MAP_PRIVATE, kd->pmfd, 0);
104 if (vm->map == MAP_FAILED) {
105 _kvm_err(kd, kd->program, "cannot map corefile");
106 return (-1);
107 }
108 vm->dmphdrsz = 0;
109 vm->eh = vm->map;
110 if (!valid_elf_header(kd, vm->eh)) {
111 /*
112 * Hmmm, no ELF header. Maybe we still have a dump header.
113 * This is normal when the core file wasn't created by
114 * savecore(8), but instead was dumped over TFTP. We can
115 * easily skip the dump header...
116 */
117 vm->dmphdrsz = dump_header_size(vm->map);
118 if (vm->dmphdrsz == 0)
119 goto inval;
120 vm->eh = (void *)((uintptr_t)vm->map + vm->dmphdrsz);
121 if (!valid_elf_header(kd, vm->eh))
122 goto inval;
123 }
124 mapsz = _kvm16toh(kd, vm->eh->e_phentsize) *
125 _kvm16toh(kd, vm->eh->e_phnum) + _kvm64toh(kd, vm->eh->e_phoff);
126 munmap(vm->map, vm->mapsz);
127
128 /* Map all headers. */
129 vm->mapsz = vm->dmphdrsz + mapsz;
130 vm->map = mmap(NULL, vm->mapsz, PROT_READ, MAP_PRIVATE, kd->pmfd, 0);
131 if (vm->map == MAP_FAILED) {
132 _kvm_err(kd, kd->program, "cannot map corefile headers");
133 return (-1);
134 }
135 vm->eh = (void *)((uintptr_t)vm->map + vm->dmphdrsz);
136 vm->ph = (void *)((uintptr_t)vm->eh +
137 (uintptr_t)_kvm64toh(kd, vm->eh->e_phoff));
138 return (0);
139
140 inval:
141 _kvm_err(kd, kd->program, "invalid corefile");
142 return (-1);
143 }
144
145 /*
146 * Determine the offset within the corefile corresponding the virtual
147 * address. Return the number of contiguous bytes in the corefile or
148 * 0 when the virtual address is invalid.
149 */
150 static size_t
powerpc64_va2off(kvm_t * kd,kvaddr_t va,off_t * ofs)151 powerpc64_va2off(kvm_t *kd, kvaddr_t va, off_t *ofs)
152 {
153 struct vmstate *vm = kd->vmst;
154 Elf64_Phdr *ph;
155 int nph;
156
157 ph = vm->ph;
158 nph = _kvm16toh(kd, vm->eh->e_phnum);
159 while (nph && (va < _kvm64toh(kd, ph->p_vaddr) ||
160 va >= _kvm64toh(kd, ph->p_vaddr) + _kvm64toh(kd, ph->p_memsz))) {
161 nph--;
162 ph = (void *)((uintptr_t)ph +
163 _kvm16toh(kd, vm->eh->e_phentsize));
164 }
165 if (nph == 0)
166 return (0);
167
168 /* Segment found. Return file offset and range. */
169 *ofs = vm->dmphdrsz + _kvm64toh(kd, ph->p_offset) +
170 (va - _kvm64toh(kd, ph->p_vaddr));
171 return (_kvm64toh(kd, ph->p_memsz) -
172 (va - _kvm64toh(kd, ph->p_vaddr)));
173 }
174
175 static void
_powerpc64_freevtop(kvm_t * kd)176 _powerpc64_freevtop(kvm_t *kd)
177 {
178 struct vmstate *vm = kd->vmst;
179
180 if (vm->eh != MAP_FAILED)
181 munmap(vm->eh, vm->mapsz);
182 free(vm);
183 kd->vmst = NULL;
184 }
185
186 static int
_powerpc64_probe(kvm_t * kd)187 _powerpc64_probe(kvm_t *kd)
188 {
189
190 return (_kvm_probe_elf_kernel(kd, ELFCLASS64, EM_PPC64) &&
191 kd->nlehdr.e_ident[EI_DATA] == ELFDATA2MSB);
192 }
193
194 static int
_powerpc64le_probe(kvm_t * kd)195 _powerpc64le_probe(kvm_t *kd)
196 {
197
198 return (_kvm_probe_elf_kernel(kd, ELFCLASS64, EM_PPC64) &&
199 kd->nlehdr.e_ident[EI_DATA] == ELFDATA2LSB);
200 }
201
202 static int
_powerpc64_initvtop(kvm_t * kd)203 _powerpc64_initvtop(kvm_t *kd)
204 {
205
206 kd->vmst = (struct vmstate *)_kvm_malloc(kd, sizeof(*kd->vmst));
207 if (kd->vmst == NULL)
208 return (-1);
209
210 if (powerpc_maphdrs(kd) == -1)
211 return (-1);
212
213 return (0);
214 }
215
216 static int
_powerpc64_kvatop(kvm_t * kd,kvaddr_t va,off_t * ofs)217 _powerpc64_kvatop(kvm_t *kd, kvaddr_t va, off_t *ofs)
218 {
219 struct vmstate *vm;
220
221 vm = kd->vmst;
222 if (_kvm64toh(kd, vm->ph->p_paddr) == 0xffffffffffffffff)
223 return ((int)powerpc64_va2off(kd, va, ofs));
224
225 _kvm_err(kd, kd->program, "Raw corefile not supported");
226 return (0);
227 }
228
229 static int
_powerpc64_native(kvm_t * kd __unused)230 _powerpc64_native(kvm_t *kd __unused)
231 {
232
233 #if defined(__powerpc64__) && BYTE_ORDER == BIG_ENDIAN
234 return (1);
235 #else
236 return (0);
237 #endif
238 }
239
240 static int
_powerpc64le_native(kvm_t * kd __unused)241 _powerpc64le_native(kvm_t *kd __unused)
242 {
243
244 #if defined(__powerpc64__) && BYTE_ORDER == LITTLE_ENDIAN
245 return (1);
246 #else
247 return (0);
248 #endif
249 }
250
251 static struct kvm_arch kvm_powerpc64 = {
252 .ka_probe = _powerpc64_probe,
253 .ka_initvtop = _powerpc64_initvtop,
254 .ka_freevtop = _powerpc64_freevtop,
255 .ka_kvatop = _powerpc64_kvatop,
256 .ka_native = _powerpc64_native,
257 };
258
259 static struct kvm_arch kvm_powerpc64le = {
260 .ka_probe = _powerpc64le_probe,
261 .ka_initvtop = _powerpc64_initvtop,
262 .ka_freevtop = _powerpc64_freevtop,
263 .ka_kvatop = _powerpc64_kvatop,
264 .ka_native = _powerpc64le_native,
265 };
266
267 KVM_ARCH(kvm_powerpc64);
268 KVM_ARCH(kvm_powerpc64le);
269