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 __FBSDID("$FreeBSD$"); 33 34 #include <sys/param.h> 35 #include <sys/endian.h> 36 #include <sys/kerneldump.h> 37 #include <sys/mman.h> 38 39 #include <elf.h> 40 #include <kvm.h> 41 #include <limits.h> 42 #include <stdlib.h> 43 #include <string.h> 44 45 #include "kvm_private.h" 46 47 struct vmstate { 48 void *map; 49 size_t mapsz; 50 size_t dmphdrsz; 51 Elf32_Ehdr *eh; 52 Elf32_Phdr *ph; 53 }; 54 55 static int 56 valid_elf_header(Elf32_Ehdr *eh) 57 { 58 59 if (!IS_ELF(*eh)) 60 return (0); 61 if (eh->e_ident[EI_CLASS] != ELFCLASS32) 62 return (0); 63 if (eh->e_ident[EI_DATA] != ELFDATA2MSB) 64 return (0); 65 if (eh->e_ident[EI_VERSION] != EV_CURRENT) 66 return (0); 67 if (eh->e_ident[EI_OSABI] != ELFOSABI_STANDALONE) 68 return (0); 69 if (be16toh(eh->e_type) != ET_CORE) 70 return (0); 71 if (be16toh(eh->e_machine) != EM_PPC) 72 return (0); 73 /* Can't think of anything else to check... */ 74 return (1); 75 } 76 77 static size_t 78 dump_header_size(struct kerneldumpheader *dh) 79 { 80 81 if (strcmp(dh->magic, KERNELDUMPMAGIC) != 0) 82 return (0); 83 if (strcmp(dh->architecture, "powerpc") != 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 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(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(vm->eh)) 122 goto inval; 123 } 124 mapsz = be16toh(vm->eh->e_phentsize) * be16toh(vm->eh->e_phnum) + 125 be32toh(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 + be32toh(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 150 powerpc_va2off(kvm_t *kd, kvaddr_t va, off_t *ofs) 151 { 152 struct vmstate *vm = kd->vmst; 153 Elf32_Phdr *ph; 154 int nph; 155 156 ph = vm->ph; 157 nph = be16toh(vm->eh->e_phnum); 158 while (nph && (va < be32toh(ph->p_vaddr) || 159 va >= be32toh(ph->p_vaddr) + be32toh(ph->p_memsz))) { 160 nph--; 161 ph = (void *)((uintptr_t)ph + be16toh(vm->eh->e_phentsize)); 162 } 163 if (nph == 0) 164 return (0); 165 166 /* Segment found. Return file offset and range. */ 167 *ofs = vm->dmphdrsz + be32toh(ph->p_offset) + 168 (va - be32toh(ph->p_vaddr)); 169 return (be32toh(ph->p_memsz) - (va - be32toh(ph->p_vaddr))); 170 } 171 172 static void 173 _powerpc_freevtop(kvm_t *kd) 174 { 175 struct vmstate *vm = kd->vmst; 176 177 if (vm->eh != MAP_FAILED) 178 munmap(vm->eh, vm->mapsz); 179 free(vm); 180 kd->vmst = NULL; 181 } 182 183 static int 184 _powerpc_probe(kvm_t *kd) 185 { 186 187 return (_kvm_probe_elf_kernel(kd, ELFCLASS32, EM_PPC) && 188 kd->nlehdr.e_ident[EI_DATA] == ELFDATA2MSB); 189 } 190 191 static int 192 _powerpc_initvtop(kvm_t *kd) 193 { 194 195 kd->vmst = (struct vmstate *)_kvm_malloc(kd, sizeof(*kd->vmst)); 196 if (kd->vmst == NULL) 197 return (-1); 198 199 if (powerpc_maphdrs(kd) == -1) 200 return (-1); 201 202 return (0); 203 } 204 205 static int 206 _powerpc_kvatop(kvm_t *kd, kvaddr_t va, off_t *ofs) 207 { 208 struct vmstate *vm; 209 210 vm = kd->vmst; 211 if (be32toh(vm->ph->p_paddr) == 0xffffffff) 212 return ((int)powerpc_va2off(kd, va, ofs)); 213 214 _kvm_err(kd, kd->program, "Raw corefile not supported"); 215 return (0); 216 } 217 218 static int 219 _powerpc_native(kvm_t *kd __unused) 220 { 221 222 #if defined(__powerpc__) && !defined(__powerpc64__) 223 return (1); 224 #else 225 return (0); 226 #endif 227 } 228 229 static struct kvm_arch kvm_powerpc = { 230 .ka_probe = _powerpc_probe, 231 .ka_initvtop = _powerpc_initvtop, 232 .ka_freevtop = _powerpc_freevtop, 233 .ka_kvatop = _powerpc_kvatop, 234 .ka_native = _powerpc_native, 235 }; 236 237 KVM_ARCH(kvm_powerpc); 238