1 /* Get ELF program header table. 2 Copyright (C) 1998-2010, 2014, 2015 Red Hat, Inc. 3 This file is part of elfutils. 4 Written by Ulrich Drepper <drepper (at) redhat.com>, 1998. 5 6 This file is free software; you can redistribute it and/or modify 7 it under the terms of either 8 9 * the GNU Lesser General Public License as published by the Free 10 Software Foundation; either version 3 of the License, or (at 11 your option) any later version 12 13 or 14 15 * the GNU General Public License as published by the Free 16 Software Foundation; either version 2 of the License, or (at 17 your option) any later version 18 19 or both in parallel, as here. 20 21 elfutils is distributed in the hope that it will be useful, but 22 WITHOUT ANY WARRANTY; without even the implied warranty of 23 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 24 General Public License for more details. 25 26 You should have received copies of the GNU General Public License and 27 the GNU Lesser General Public License along with this program. If 28 not, see <http://www.gnu.org/licenses/>. */ 29 30 #ifdef HAVE_CONFIG_H 31 # include <config.h> 32 #endif 33 34 #include <errno.h> 35 #include <stdbool.h> 36 #include <stdlib.h> 37 #include <unistd.h> 38 #include <assert.h> 39 40 #include <system.h> 41 #include "libelfP.h" 42 #include "common.h" 43 44 #ifndef LIBELFBITS 45 # define LIBELFBITS 32 46 #endif 47 48 ElfW2(LIBELFBITS,Phdr) * 49 __elfw2(LIBELFBITS,getphdr_wrlock) (Elf *elf) 50 { 51 ElfW2(LIBELFBITS,Phdr) *result; 52 53 /* If the program header entry has already been filled in the code 54 below must already have been run. So the class is set, too. No 55 need to waste any more time here. */ 56 result = elf->state.ELFW(elf,LIBELFBITS).phdr; 57 if (likely (result != NULL)) 58 return result; 59 60 if (elf->class == 0) 61 elf->class = ELFW(ELFCLASS,LIBELFBITS); 62 else if (elf->class != ELFW(ELFCLASS,LIBELFBITS)) 63 { 64 __libelf_seterrno (ELF_E_INVALID_CLASS); 65 result = NULL; 66 goto out; 67 } 68 69 if (likely (result == NULL)) 70 { 71 /* Read the section header table. */ 72 ElfW2(LIBELFBITS,Ehdr) *ehdr = elf->state.ELFW(elf,LIBELFBITS).ehdr; 73 74 /* If no program header exists return NULL. */ 75 size_t phnum; 76 if (__elf_getphdrnum_rdlock (elf, &phnum) != 0) 77 goto out; 78 if (phnum == 0 || ehdr->e_phoff == 0) 79 { 80 __libelf_seterrno (ELF_E_NO_PHDR); 81 goto out; 82 } 83 84 /* Check this doesn't overflow. */ 85 size_t size = phnum * sizeof (ElfW2(LIBELFBITS,Phdr)); 86 87 if (phnum > SIZE_MAX / sizeof (ElfW2(LIBELFBITS,Phdr)) 88 || ehdr->e_phoff > elf->maximum_size 89 || elf->maximum_size - ehdr->e_phoff < size) 90 { 91 __libelf_seterrno (ELF_E_INVALID_DATA); 92 goto out; 93 } 94 95 if (elf->map_address != NULL) 96 { 97 /* First see whether the information in the ELF header is 98 valid and it does not ask for too much. */ 99 if (unlikely (ehdr->e_phoff >= elf->maximum_size) 100 || unlikely (elf->maximum_size - ehdr->e_phoff < size)) 101 { 102 /* Something is wrong. */ 103 __libelf_seterrno (ELF_E_INVALID_PHDR); 104 goto out; 105 } 106 107 /* All the data is already mapped. Use it. */ 108 void *file_phdr = ((char *) elf->map_address 109 + elf->start_offset + ehdr->e_phoff); 110 if (ehdr->e_ident[EI_DATA] == MY_ELFDATA 111 && (ALLOW_UNALIGNED 112 || ((uintptr_t) file_phdr 113 & (__alignof__ (ElfW2(LIBELFBITS,Phdr)) - 1)) == 0)) 114 /* Simply use the mapped data. */ 115 elf->state.ELFW(elf,LIBELFBITS).phdr = file_phdr; 116 else 117 { 118 ElfW2(LIBELFBITS,Phdr) *notcvt; 119 ElfW2(LIBELFBITS,Phdr) *phdr; 120 121 /* Allocate memory for the program headers. We know the number 122 of entries from the ELF header. */ 123 phdr = elf->state.ELFW(elf,LIBELFBITS).phdr = 124 (ElfW2(LIBELFBITS,Phdr) *) malloc (size); 125 if (elf->state.ELFW(elf,LIBELFBITS).phdr == NULL) 126 { 127 __libelf_seterrno (ELF_E_NOMEM); 128 goto out; 129 } 130 elf->state.ELFW(elf,LIBELFBITS).phdr_flags |= 131 ELF_F_MALLOCED | ELF_F_DIRTY; 132 133 /* Now copy the data and at the same time convert the 134 byte order. */ 135 136 if (ehdr->e_ident[EI_DATA] == MY_ELFDATA) 137 { 138 assert (! ALLOW_UNALIGNED); 139 memcpy (phdr, file_phdr, size); 140 } 141 else 142 { 143 bool copy = ! (ALLOW_UNALIGNED 144 || ((uintptr_t) file_phdr 145 & (__alignof__ (ElfW2(LIBELFBITS,Phdr)) 146 - 1)) == 0); 147 if (! copy) 148 notcvt = file_phdr; 149 else 150 { 151 notcvt = (ElfW2(LIBELFBITS,Phdr) *) malloc (size); 152 if (unlikely (notcvt == NULL)) 153 { 154 __libelf_seterrno (ELF_E_NOMEM); 155 goto out; 156 } 157 memcpy (notcvt, file_phdr, size); 158 } 159 160 for (size_t cnt = 0; cnt < phnum; ++cnt) 161 { 162 CONVERT_TO (phdr[cnt].p_type, notcvt[cnt].p_type); 163 CONVERT_TO (phdr[cnt].p_offset, notcvt[cnt].p_offset); 164 CONVERT_TO (phdr[cnt].p_vaddr, notcvt[cnt].p_vaddr); 165 CONVERT_TO (phdr[cnt].p_paddr, notcvt[cnt].p_paddr); 166 CONVERT_TO (phdr[cnt].p_filesz, notcvt[cnt].p_filesz); 167 CONVERT_TO (phdr[cnt].p_memsz, notcvt[cnt].p_memsz); 168 CONVERT_TO (phdr[cnt].p_flags, notcvt[cnt].p_flags); 169 CONVERT_TO (phdr[cnt].p_align, notcvt[cnt].p_align); 170 } 171 172 if (copy) 173 free (notcvt); 174 } 175 } 176 } 177 else if (likely (elf->fildes != -1)) 178 { 179 /* Allocate memory for the program headers. We know the number 180 of entries from the ELF header. */ 181 elf->state.ELFW(elf,LIBELFBITS).phdr = 182 (ElfW2(LIBELFBITS,Phdr) *) malloc (size); 183 if (elf->state.ELFW(elf,LIBELFBITS).phdr == NULL) 184 { 185 __libelf_seterrno (ELF_E_NOMEM); 186 goto out; 187 } 188 elf->state.ELFW(elf,LIBELFBITS).phdr_flags |= ELF_F_MALLOCED; 189 190 /* Read the header. */ 191 ssize_t n = pread_retry (elf->fildes, 192 elf->state.ELFW(elf,LIBELFBITS).phdr, size, 193 elf->start_offset + ehdr->e_phoff); 194 if (unlikely ((size_t) n != size)) 195 { 196 /* Severe problems. We cannot read the data. */ 197 __libelf_seterrno (ELF_E_READ_ERROR); 198 free (elf->state.ELFW(elf,LIBELFBITS).phdr); 199 elf->state.ELFW(elf,LIBELFBITS).phdr = NULL; 200 goto out; 201 } 202 203 /* If the byte order of the file is not the same as the one 204 of the host convert the data now. */ 205 if (ehdr->e_ident[EI_DATA] != MY_ELFDATA) 206 { 207 ElfW2(LIBELFBITS,Phdr) *phdr 208 = elf->state.ELFW(elf,LIBELFBITS).phdr; 209 210 for (size_t cnt = 0; cnt < phnum; ++cnt) 211 { 212 CONVERT (phdr[cnt].p_type); 213 CONVERT (phdr[cnt].p_offset); 214 CONVERT (phdr[cnt].p_vaddr); 215 CONVERT (phdr[cnt].p_paddr); 216 CONVERT (phdr[cnt].p_filesz); 217 CONVERT (phdr[cnt].p_memsz); 218 CONVERT (phdr[cnt].p_flags); 219 CONVERT (phdr[cnt].p_align); 220 } 221 } 222 } 223 else 224 { 225 /* The file descriptor was already enabled and not all data was 226 read. */ 227 __libelf_seterrno (ELF_E_FD_DISABLED); 228 goto out; 229 } 230 231 result = elf->state.ELFW(elf,LIBELFBITS).phdr; 232 } 233 234 out: 235 return result; 236 } 237 238 ElfW2(LIBELFBITS,Phdr) * 239 elfw2(LIBELFBITS,getphdr) (Elf *elf) 240 { 241 ElfW2(LIBELFBITS,Phdr) *result; 242 243 if (elf == NULL) 244 return NULL; 245 246 if (unlikely (elf->kind != ELF_K_ELF)) 247 { 248 __libelf_seterrno (ELF_E_INVALID_HANDLE); 249 return NULL; 250 } 251 252 /* If the program header entry has already been filled in the code 253 * in getphdr_wrlock must already have been run. So the class is 254 * set, too. No need to waste any more time here. */ 255 result = elf->state.ELFW(elf,LIBELFBITS).phdr; 256 if (likely (result != NULL)) 257 return result; 258 259 rwlock_wrlock (elf->lock); 260 result = __elfw2(LIBELFBITS,getphdr_wrlock) (elf); 261 rwlock_unlock (elf->lock); 262 263 return result; 264 } 265 INTDEF(elfw2(LIBELFBITS,getphdr)) 266
