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 Elf32_Ehdr *eh; 50 Elf32_Phdr *ph; 51 }; 52 53 static int 54 valid_elf_header(Elf32_Ehdr *eh) 55 { 56 57 if (!IS_ELF(*eh)) 58 return (0); 59 if (eh->e_ident[EI_CLASS] != ELFCLASS32) 60 return (0); 61 if (eh->e_ident[EI_DATA] != ELFDATA2MSB) 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 (be16toh(eh->e_type) != ET_CORE) 68 return (0); 69 if (be16toh(eh->e_machine) != EM_PPC) 70 return (0); 71 /* Can't think of anything else to check... */ 72 return (1); 73 } 74 75 static size_t 76 dump_header_size(struct kerneldumpheader *dh) 77 { 78 79 if (strcmp(dh->magic, KERNELDUMPMAGIC) != 0) 80 return (0); 81 if (strcmp(dh->architecture, "powerpc") != 0) 82 return (0); 83 /* That should do it... */ 84 return (sizeof(*dh)); 85 } 86 87 /* 88 * Map the ELF headers into the process' address space. We do this in two 89 * steps: first the ELF header itself and using that information the whole 90 * set of headers. 91 */ 92 static int 93 powerpc_maphdrs(kvm_t *kd) 94 { 95 struct vmstate *vm; 96 size_t mapsz; 97 98 vm = kd->vmst; 99 100 vm->mapsz = sizeof(*vm->eh) + sizeof(struct kerneldumpheader); 101 vm->map = mmap(NULL, vm->mapsz, PROT_READ, MAP_PRIVATE, kd->pmfd, 0); 102 if (vm->map == MAP_FAILED) { 103 _kvm_err(kd, kd->program, "cannot map corefile"); 104 return (-1); 105 } 106 vm->dmphdrsz = 0; 107 vm->eh = vm->map; 108 if (!valid_elf_header(vm->eh)) { 109 /* 110 * Hmmm, no ELF header. Maybe we still have a dump header. 111 * This is normal when the core file wasn't created by 112 * savecore(8), but instead was dumped over TFTP. We can 113 * easily skip the dump header... 114 */ 115 vm->dmphdrsz = dump_header_size(vm->map); 116 if (vm->dmphdrsz == 0) 117 goto inval; 118 vm->eh = (void *)((uintptr_t)vm->map + vm->dmphdrsz); 119 if (!valid_elf_header(vm->eh)) 120 goto inval; 121 } 122 mapsz = be16toh(vm->eh->e_phentsize) * be16toh(vm->eh->e_phnum) + 123 be32toh(vm->eh->e_phoff); 124 munmap(vm->map, vm->mapsz); 125 126 /* Map all headers. */ 127 vm->mapsz = vm->dmphdrsz + mapsz; 128 vm->map = mmap(NULL, vm->mapsz, PROT_READ, MAP_PRIVATE, kd->pmfd, 0); 129 if (vm->map == MAP_FAILED) { 130 _kvm_err(kd, kd->program, "cannot map corefile headers"); 131 return (-1); 132 } 133 vm->eh = (void *)((uintptr_t)vm->map + vm->dmphdrsz); 134 vm->ph = (void *)((uintptr_t)vm->eh + be32toh(vm->eh->e_phoff)); 135 return (0); 136 137 inval: 138 _kvm_err(kd, kd->program, "invalid corefile"); 139 return (-1); 140 } 141 142 /* 143 * Determine the offset within the corefile corresponding the virtual 144 * address. Return the number of contiguous bytes in the corefile or 145 * 0 when the virtual address is invalid. 146 */ 147 static size_t 148 powerpc_va2off(kvm_t *kd, kvaddr_t va, off_t *ofs) 149 { 150 struct vmstate *vm = kd->vmst; 151 Elf32_Phdr *ph; 152 int nph; 153 154 ph = vm->ph; 155 nph = be16toh(vm->eh->e_phnum); 156 while (nph && (va < be32toh(ph->p_vaddr) || 157 va >= be32toh(ph->p_vaddr) + be32toh(ph->p_memsz))) { 158 nph--; 159 ph = (void *)((uintptr_t)ph + be16toh(vm->eh->e_phentsize)); 160 } 161 if (nph == 0) 162 return (0); 163 164 /* Segment found. Return file offset and range. */ 165 *ofs = vm->dmphdrsz + be32toh(ph->p_offset) + 166 (va - be32toh(ph->p_vaddr)); 167 return (be32toh(ph->p_memsz) - (va - be32toh(ph->p_vaddr))); 168 } 169 170 static void 171 _powerpc_freevtop(kvm_t *kd) 172 { 173 struct vmstate *vm = kd->vmst; 174 175 if (vm->eh != MAP_FAILED) 176 munmap(vm->eh, vm->mapsz); 177 free(vm); 178 kd->vmst = NULL; 179 } 180 181 static int 182 _powerpc_probe(kvm_t *kd) 183 { 184 185 return (_kvm_probe_elf_kernel(kd, ELFCLASS32, EM_PPC) && 186 kd->nlehdr.e_ident[EI_DATA] == ELFDATA2MSB); 187 } 188 189 static int 190 _powerpc_initvtop(kvm_t *kd) 191 { 192 193 kd->vmst = (struct vmstate *)_kvm_malloc(kd, sizeof(*kd->vmst)); 194 if (kd->vmst == NULL) 195 return (-1); 196 197 if (powerpc_maphdrs(kd) == -1) 198 return (-1); 199 200 return (0); 201 } 202 203 static int 204 _powerpc_kvatop(kvm_t *kd, kvaddr_t va, off_t *ofs) 205 { 206 struct vmstate *vm; 207 208 vm = kd->vmst; 209 if (be32toh(vm->ph->p_paddr) == 0xffffffff) 210 return ((int)powerpc_va2off(kd, va, ofs)); 211 212 _kvm_err(kd, kd->program, "Raw corefile not supported"); 213 return (0); 214 } 215 216 static int 217 _powerpc_native(kvm_t *kd __unused) 218 { 219 220 #if defined(__powerpc__) && !defined(__powerpc64__) 221 return (1); 222 #else 223 return (0); 224 #endif 225 } 226 227 static struct kvm_arch kvm_powerpc = { 228 .ka_probe = _powerpc_probe, 229 .ka_initvtop = _powerpc_initvtop, 230 .ka_freevtop = _powerpc_freevtop, 231 .ka_kvatop = _powerpc_kvatop, 232 .ka_native = _powerpc_native, 233 }; 234 235 KVM_ARCH(kvm_powerpc); 236