1 /*- 2 * Copyright (c) 2006,2008 Joseph Koshy 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 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 */ 26 27 #include <assert.h> 28 #include <gelf.h> 29 #include <libelf.h> 30 #include <stdlib.h> 31 32 #include "_libelf.h" 33 34 ELFTC_VCSID("$Id: libelf_phdr.c 3732 2019-04-22 11:08:38Z jkoshy $"); 35 36 void * 37 _libelf_getphdr(Elf *e, int ec) 38 { 39 size_t phnum; 40 size_t fsz, msz; 41 uint64_t phoff; 42 Elf32_Ehdr *eh32; 43 Elf64_Ehdr *eh64; 44 void *ehdr, *phdr; 45 _libelf_translator_function *xlator; 46 47 assert(ec == ELFCLASS32 || ec == ELFCLASS64); 48 49 if (e == NULL) { 50 LIBELF_SET_ERROR(ARGUMENT, 0); 51 return (NULL); 52 } 53 54 if ((phdr = (ec == ELFCLASS32 ? 55 (void *) e->e_u.e_elf.e_phdr.e_phdr32 : 56 (void *) e->e_u.e_elf.e_phdr.e_phdr64)) != NULL) 57 return (phdr); 58 59 /* 60 * Check the PHDR related fields in the EHDR for sanity. 61 */ 62 63 if ((ehdr = _libelf_ehdr(e, ec, 0)) == NULL) 64 return (NULL); 65 66 phnum = e->e_u.e_elf.e_nphdr; 67 68 if (ec == ELFCLASS32) { 69 eh32 = (Elf32_Ehdr *) ehdr; 70 phoff = (uint64_t) eh32->e_phoff; 71 } else { 72 eh64 = (Elf64_Ehdr *) ehdr; 73 phoff = (uint64_t) eh64->e_phoff; 74 } 75 76 fsz = gelf_fsize(e, ELF_T_PHDR, phnum, e->e_version); 77 78 assert(fsz > 0); 79 80 if (phoff + fsz < phoff) { /* Numeric overflow. */ 81 LIBELF_SET_ERROR(HEADER, 0); 82 return (NULL); 83 } 84 85 if ((uint64_t) e->e_rawsize < (phoff + fsz)) { 86 LIBELF_SET_ERROR(HEADER, 0); 87 return (NULL); 88 } 89 90 if ((msz = _libelf_msize(ELF_T_PHDR, ec, EV_CURRENT)) == 0) 91 return (NULL); 92 93 if ((phdr = calloc(phnum, msz)) == NULL) { 94 LIBELF_SET_ERROR(RESOURCE, 0); 95 return (NULL); 96 } 97 98 if (ec == ELFCLASS32) 99 e->e_u.e_elf.e_phdr.e_phdr32 = phdr; 100 else 101 e->e_u.e_elf.e_phdr.e_phdr64 = phdr; 102 103 104 xlator = _libelf_get_translator(ELF_T_PHDR, ELF_TOMEMORY, ec, 105 _libelf_elfmachine(e)); 106 (*xlator)(phdr, phnum * msz, e->e_rawfile + phoff, phnum, 107 e->e_byteorder != LIBELF_PRIVATE(byteorder)); 108 109 return (phdr); 110 } 111 112 void * 113 _libelf_newphdr(Elf *e, int ec, size_t count) 114 { 115 void *ehdr, *newphdr, *oldphdr; 116 size_t msz; 117 118 if (e == NULL) { 119 LIBELF_SET_ERROR(ARGUMENT, 0); 120 return (NULL); 121 } 122 123 if ((ehdr = _libelf_ehdr(e, ec, 0)) == NULL) { 124 LIBELF_SET_ERROR(SEQUENCE, 0); 125 return (NULL); 126 } 127 128 assert(e->e_class == ec); 129 assert(ec == ELFCLASS32 || ec == ELFCLASS64); 130 assert(e->e_version == EV_CURRENT); 131 132 if ((msz = _libelf_msize(ELF_T_PHDR, ec, e->e_version)) == 0) 133 return (NULL); 134 135 newphdr = NULL; 136 if (count > 0 && (newphdr = calloc(count, msz)) == NULL) { 137 LIBELF_SET_ERROR(RESOURCE, 0); 138 return (NULL); 139 } 140 141 if (ec == ELFCLASS32) { 142 if ((oldphdr = (void *) e->e_u.e_elf.e_phdr.e_phdr32) != NULL) 143 free(oldphdr); 144 e->e_u.e_elf.e_phdr.e_phdr32 = (Elf32_Phdr *) newphdr; 145 } else { 146 if ((oldphdr = (void *) e->e_u.e_elf.e_phdr.e_phdr64) != NULL) 147 free(oldphdr); 148 e->e_u.e_elf.e_phdr.e_phdr64 = (Elf64_Phdr *) newphdr; 149 } 150 151 e->e_u.e_elf.e_nphdr = count; 152 153 elf_flagphdr(e, ELF_C_SET, ELF_F_DIRTY); 154 155 return (newphdr); 156 } 157