1 /*- 2 * Copyright (c) 2008, Juniper Networks, Inc. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the author nor the names of any co-contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29 #include <sys/cdefs.h> 30 __FBSDID("$FreeBSD$"); 31 32 #include <sys/param.h> 33 #include <sys/endian.h> 34 #include <sys/kerneldump.h> 35 #include <sys/mman.h> 36 37 #include <vm/vm.h> 38 39 #include <db.h> 40 #include <elf.h> 41 #include <limits.h> 42 #include <kvm.h> 43 #include <stdlib.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 = PAGE_SIZE; 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 corefle 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 munmap(vm->map, vm->mapsz); 141 vm->map = MAP_FAILED; 142 _kvm_err(kd, kd->program, "invalid corefile"); 143 return (-1); 144 } 145 146 /* 147 * Determine the offset within the corefile corresponding the virtual 148 * address. Return the number of contiguous bytes in the corefile or 149 * 0 when the virtual address is invalid. 150 */ 151 static size_t 152 powerpc_va2off(kvm_t *kd, u_long va, off_t *ofs) 153 { 154 struct vmstate *vm = kd->vmst; 155 Elf32_Phdr *ph; 156 int nph; 157 158 ph = vm->ph; 159 nph = be16toh(vm->eh->e_phnum); 160 while (nph && (va < be32toh(ph->p_vaddr) || 161 va >= be32toh(ph->p_vaddr) + be32toh(ph->p_memsz))) { 162 nph--; 163 ph = (void *)((uintptr_t)ph + be16toh(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 + be32toh(ph->p_offset) + 170 (va - be32toh(ph->p_vaddr)); 171 return (be32toh(ph->p_memsz) - (va - be32toh(ph->p_vaddr))); 172 } 173 174 void 175 _kvm_freevtop(kvm_t *kd) 176 { 177 struct vmstate *vm = kd->vmst; 178 179 if (vm == NULL) 180 return; 181 182 if (vm->eh != MAP_FAILED) { 183 munmap(vm->eh, vm->mapsz); 184 vm->eh = MAP_FAILED; 185 } 186 free(vm); 187 kd->vmst = NULL; 188 } 189 190 int 191 _kvm_initvtop(kvm_t *kd) 192 { 193 194 kd->vmst = (struct vmstate *)_kvm_malloc(kd, sizeof(*kd->vmst)); 195 if (kd->vmst == NULL) { 196 _kvm_err(kd, kd->program, "out of virtual memory"); 197 return (-1); 198 } 199 if (powerpc_maphdrs(kd) == -1) { 200 free(kd->vmst); 201 kd->vmst = NULL; 202 return (-1); 203 } 204 return (0); 205 } 206 207 int 208 _kvm_kvatop(kvm_t *kd, u_long va, off_t *ofs) 209 { 210 struct vmstate *vm; 211 212 vm = kd->vmst; 213 if (vm->ph->p_paddr == ~0U) 214 return ((int)powerpc_va2off(kd, va, ofs)); 215 216 _kvm_err(kd, kd->program, "Raw corefile not supported"); 217 return (0); 218 } 219