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_sym.c 3732 2019-04-22 11:08:38Z jkoshy $"); 35 36 GElf_Sym * 37 gelf_getsym(Elf_Data *ed, int ndx, GElf_Sym *dst) 38 { 39 int ec; 40 Elf *e; 41 size_t msz; 42 Elf_Scn *scn; 43 uint32_t sh_type; 44 Elf32_Sym *sym32; 45 Elf64_Sym *sym64; 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_SYM) { 66 LIBELF_SET_ERROR(ARGUMENT, 0); 67 return (NULL); 68 } 69 70 if ((msz = _libelf_msize(ELF_T_SYM, 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 sym32 = (Elf32_Sym *) d->d_data.d_buf + ndx; 82 83 dst->st_name = sym32->st_name; 84 dst->st_value = (Elf64_Addr) sym32->st_value; 85 dst->st_size = (Elf64_Xword) sym32->st_size; 86 dst->st_info = sym32->st_info; 87 dst->st_other = sym32->st_other; 88 dst->st_shndx = sym32->st_shndx; 89 } else { 90 sym64 = (Elf64_Sym *) d->d_data.d_buf + ndx; 91 92 *dst = *sym64; 93 } 94 95 return (dst); 96 } 97 98 int 99 gelf_update_sym(Elf_Data *ed, int ndx, GElf_Sym *gs) 100 { 101 int ec; 102 Elf *e; 103 size_t msz; 104 Elf_Scn *scn; 105 uint32_t sh_type; 106 Elf32_Sym *sym32; 107 Elf64_Sym *sym64; 108 struct _Libelf_Data *d; 109 110 d = (struct _Libelf_Data *) ed; 111 112 if (d == NULL || ndx < 0 || gs == NULL || 113 (scn = d->d_scn) == NULL || 114 (e = scn->s_elf) == NULL) { 115 LIBELF_SET_ERROR(ARGUMENT, 0); 116 return (0); 117 } 118 119 ec = e->e_class; 120 assert(ec == ELFCLASS32 || ec == ELFCLASS64); 121 122 if (ec == ELFCLASS32) 123 sh_type = scn->s_shdr.s_shdr32.sh_type; 124 else 125 sh_type = scn->s_shdr.s_shdr64.sh_type; 126 127 if (_libelf_xlate_shtype(sh_type) != ELF_T_SYM) { 128 LIBELF_SET_ERROR(ARGUMENT, 0); 129 return (0); 130 } 131 132 if ((msz = _libelf_msize(ELF_T_SYM, ec, e->e_version)) == 0) 133 return (0); 134 135 assert(ndx >= 0); 136 137 if (msz * (size_t) ndx >= d->d_data.d_size) { 138 LIBELF_SET_ERROR(ARGUMENT, 0); 139 return (0); 140 } 141 142 if (ec == ELFCLASS32) { 143 sym32 = (Elf32_Sym *) d->d_data.d_buf + ndx; 144 145 sym32->st_name = gs->st_name; 146 sym32->st_info = gs->st_info; 147 sym32->st_other = gs->st_other; 148 sym32->st_shndx = gs->st_shndx; 149 150 LIBELF_COPY_U32(sym32, gs, st_value); 151 LIBELF_COPY_U32(sym32, gs, st_size); 152 } else { 153 sym64 = (Elf64_Sym *) d->d_data.d_buf + ndx; 154 155 *sym64 = *gs; 156 } 157 158 return (1); 159 } 160