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 <sys/cdefs.h> 28 29 #include <assert.h> 30 #include <gelf.h> 31 #include <limits.h> 32 #include <stdint.h> 33 34 #include "_libelf.h" 35 36 ELFTC_VCSID("$Id: gelf_sym.c 2999 2014-03-18 17:19:06Z jkoshy $"); 37 38 GElf_Sym * 39 gelf_getsym(Elf_Data *ed, int ndx, GElf_Sym *dst) 40 { 41 int ec; 42 Elf *e; 43 size_t msz; 44 Elf_Scn *scn; 45 uint32_t sh_type; 46 Elf32_Sym *sym32; 47 Elf64_Sym *sym64; 48 struct _Libelf_Data *d; 49 50 d = (struct _Libelf_Data *) ed; 51 52 if (d == NULL || ndx < 0 || dst == NULL || 53 (scn = d->d_scn) == NULL || 54 (e = scn->s_elf) == NULL) { 55 LIBELF_SET_ERROR(ARGUMENT, 0); 56 return (NULL); 57 } 58 59 ec = e->e_class; 60 assert(ec == ELFCLASS32 || ec == ELFCLASS64); 61 62 if (ec == ELFCLASS32) 63 sh_type = scn->s_shdr.s_shdr32.sh_type; 64 else 65 sh_type = scn->s_shdr.s_shdr64.sh_type; 66 67 if (_libelf_xlate_shtype(sh_type) != ELF_T_SYM) { 68 LIBELF_SET_ERROR(ARGUMENT, 0); 69 return (NULL); 70 } 71 72 msz = _libelf_msize(ELF_T_SYM, ec, e->e_version); 73 74 assert(msz > 0); 75 assert(ndx >= 0); 76 77 if (msz * (size_t) ndx >= d->d_data.d_size) { 78 LIBELF_SET_ERROR(ARGUMENT, 0); 79 return (NULL); 80 } 81 82 if (ec == ELFCLASS32) { 83 sym32 = (Elf32_Sym *) d->d_data.d_buf + ndx; 84 85 dst->st_name = sym32->st_name; 86 dst->st_value = (Elf64_Addr) sym32->st_value; 87 dst->st_size = (Elf64_Xword) sym32->st_size; 88 dst->st_info = sym32->st_info; 89 dst->st_other = sym32->st_other; 90 dst->st_shndx = sym32->st_shndx; 91 } else { 92 sym64 = (Elf64_Sym *) d->d_data.d_buf + ndx; 93 94 *dst = *sym64; 95 } 96 97 return (dst); 98 } 99 100 int 101 gelf_update_sym(Elf_Data *ed, int ndx, GElf_Sym *gs) 102 { 103 int ec; 104 Elf *e; 105 size_t msz; 106 Elf_Scn *scn; 107 uint32_t sh_type; 108 Elf32_Sym *sym32; 109 Elf64_Sym *sym64; 110 struct _Libelf_Data *d; 111 112 d = (struct _Libelf_Data *) ed; 113 114 if (d == NULL || ndx < 0 || gs == NULL || 115 (scn = d->d_scn) == NULL || 116 (e = scn->s_elf) == NULL) { 117 LIBELF_SET_ERROR(ARGUMENT, 0); 118 return (0); 119 } 120 121 ec = e->e_class; 122 assert(ec == ELFCLASS32 || ec == ELFCLASS64); 123 124 if (ec == ELFCLASS32) 125 sh_type = scn->s_shdr.s_shdr32.sh_type; 126 else 127 sh_type = scn->s_shdr.s_shdr64.sh_type; 128 129 if (_libelf_xlate_shtype(sh_type) != ELF_T_SYM) { 130 LIBELF_SET_ERROR(ARGUMENT, 0); 131 return (0); 132 } 133 134 msz = _libelf_msize(ELF_T_SYM, ec, e->e_version); 135 136 assert(msz > 0); 137 assert(ndx >= 0); 138 139 if (msz * (size_t) ndx >= d->d_data.d_size) { 140 LIBELF_SET_ERROR(ARGUMENT, 0); 141 return (0); 142 } 143 144 if (ec == ELFCLASS32) { 145 sym32 = (Elf32_Sym *) d->d_data.d_buf + ndx; 146 147 sym32->st_name = gs->st_name; 148 sym32->st_info = gs->st_info; 149 sym32->st_other = gs->st_other; 150 sym32->st_shndx = gs->st_shndx; 151 152 LIBELF_COPY_U32(sym32, gs, st_value); 153 LIBELF_COPY_U32(sym32, gs, st_size); 154 } else { 155 sym64 = (Elf64_Sym *) d->d_data.d_buf + ndx; 156 157 *sym64 = *gs; 158 } 159 160 return (1); 161 } 162