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 <limits.h> 30 #include <stdint.h> 31 32 #include "_libelf.h" 33 34 ELFTC_VCSID("$Id: gelf_rel.c 3739 2019-05-06 05:18:15Z jkoshy $"); 35 36 GElf_Rel * 37 gelf_getrel(Elf_Data *ed, int ndx, GElf_Rel *dst) 38 { 39 int ec; 40 Elf *e; 41 size_t msz; 42 Elf_Scn *scn; 43 uint32_t sh_type; 44 Elf32_Rel *rel32; 45 Elf64_Rel *rel64; 46 struct _Libelf_Data *d; 47 48 d = (struct _Libelf_Data *) ed; 49 50 if (d == NULL || ndx < 0 || dst == NULL || 51 (scn = d->d_scn) == NULL || 52 (e = scn->s_elf) == NULL) { 53 LIBELF_SET_ERROR(ARGUMENT, 0); 54 return (NULL); 55 } 56 57 ec = e->e_class; 58 assert(ec == ELFCLASS32 || ec == ELFCLASS64); 59 60 if (ec == ELFCLASS32) 61 sh_type = scn->s_shdr.s_shdr32.sh_type; 62 else 63 sh_type = scn->s_shdr.s_shdr64.sh_type; 64 65 if (_libelf_xlate_shtype(sh_type) != ELF_T_REL) { 66 LIBELF_SET_ERROR(ARGUMENT, 0); 67 return (NULL); 68 } 69 70 if ((msz = _libelf_msize(ELF_T_REL, ec, e->e_version)) == 0) 71 return (NULL); 72 73 assert(ndx >= 0); 74 75 if (msz * (size_t) ndx >= d->d_data.d_size) { 76 LIBELF_SET_ERROR(ARGUMENT, 0); 77 return (NULL); 78 } 79 80 if (ec == ELFCLASS32) { 81 rel32 = (Elf32_Rel *) d->d_data.d_buf + ndx; 82 83 dst->r_offset = (Elf64_Addr) rel32->r_offset; 84 dst->r_info = ELF64_R_INFO( 85 (Elf64_Xword) ELF32_R_SYM(rel32->r_info), 86 ELF32_R_TYPE(rel32->r_info)); 87 88 } else { 89 90 rel64 = (Elf64_Rel *) d->d_data.d_buf + ndx; 91 92 *dst = *rel64; 93 94 if (_libelf_is_mips64el(e)) 95 dst->r_info = _libelf_mips64el_r_info_tom(rel64->r_info); 96 } 97 98 return (dst); 99 } 100 101 int 102 gelf_update_rel(Elf_Data *ed, int ndx, GElf_Rel *dr) 103 { 104 int ec; 105 Elf *e; 106 size_t msz; 107 Elf_Scn *scn; 108 uint32_t sh_type; 109 Elf32_Rel *rel32; 110 Elf64_Rel *rel64; 111 struct _Libelf_Data *d; 112 113 d = (struct _Libelf_Data *) ed; 114 115 if (d == NULL || ndx < 0 || dr == NULL || 116 (scn = d->d_scn) == NULL || 117 (e = scn->s_elf) == NULL) { 118 LIBELF_SET_ERROR(ARGUMENT, 0); 119 return (0); 120 } 121 122 ec = e->e_class; 123 assert(ec == ELFCLASS32 || ec == ELFCLASS64); 124 125 if (ec == ELFCLASS32) 126 sh_type = scn->s_shdr.s_shdr32.sh_type; 127 else 128 sh_type = scn->s_shdr.s_shdr64.sh_type; 129 130 if (_libelf_xlate_shtype(sh_type) != ELF_T_REL) { 131 LIBELF_SET_ERROR(ARGUMENT, 0); 132 return (0); 133 } 134 135 if ((msz = _libelf_msize(ELF_T_REL, ec, e->e_version)) == 0) 136 return (0); 137 138 assert(ndx >= 0); 139 140 if (msz * (size_t) ndx >= d->d_data.d_size) { 141 LIBELF_SET_ERROR(ARGUMENT, 0); 142 return (0); 143 } 144 145 if (ec == ELFCLASS32) { 146 rel32 = (Elf32_Rel *) d->d_data.d_buf + ndx; 147 148 LIBELF_COPY_U32(rel32, dr, r_offset); 149 150 if (ELF64_R_SYM(dr->r_info) > ELF32_R_SYM(~0U) || 151 ELF64_R_TYPE(dr->r_info) > ELF32_R_TYPE(~0U)) { 152 LIBELF_SET_ERROR(RANGE, 0); 153 return (0); 154 } 155 rel32->r_info = ELF32_R_INFO( 156 (Elf32_Word) ELF64_R_SYM(dr->r_info), 157 (Elf32_Word) ELF64_R_TYPE(dr->r_info)); 158 } else { 159 rel64 = (Elf64_Rel *) d->d_data.d_buf + ndx; 160 161 *rel64 = *dr; 162 163 if (_libelf_is_mips64el(e)) 164 rel64->r_info = _libelf_mips64el_r_info_tof(dr->r_info); 165 } 166 167 return (1); 168 } 169