lib/libelf/gelf_sym.c

   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
  32 #include "_libelf.h"
  33
  34 LIBELF_VCSID("$Id$");
  35
  36 GElf_Sym *
  37 gelf_getsym(Elf_Data *d, int ndx, GElf_Sym *dst)
  38 {
  39         int ec;
  40         Elf *e;
  41         Elf_Scn *scn;
  42         Elf32_Sym *sym32;
  43         Elf64_Sym *sym64;
  44         size_t msz;
  45         uint32_t sh_type;
  46
  47         if (d == NULL || ndx < 0 || dst == NULL ||
  48             (scn = d->d_scn) == NULL ||
  49             (e = scn->s_elf) == NULL) {
  50                 LIBELF_SET_ERROR(ARGUMENT, 0);
  51                 return (NULL);
  52         }
  53
  54         ec = e->e_class;
  55         assert(ec == ELFCLASS32 || ec == ELFCLASS64);
  56
  57         if (ec == ELFCLASS32)
  58                 sh_type = scn->s_shdr.s_shdr32.sh_type;
  59         else
  60                 sh_type = scn->s_shdr.s_shdr64.sh_type;
  61
  62         if (_libelf_xlate_shtype(sh_type) != ELF_T_SYM) {
  63                 LIBELF_SET_ERROR(ARGUMENT, 0);
  64                 return (NULL);
  65         }
  66
  67         msz = _libelf_msize(ELF_T_SYM, ec, e->e_version);
  68
  69         assert(msz > 0);
  70
  71         if (msz * ndx >= d->d_size) {
  72                 LIBELF_SET_ERROR(ARGUMENT, 0);
  73                 return (NULL);
  74         }
  75
  76         if (ec == ELFCLASS32) {
  77
  78                 sym32 = (Elf32_Sym *) d->d_buf + ndx;
  79
  80                 dst->st_name  = sym32->st_name;
  81                 dst->st_value = (Elf64_Addr) sym32->st_value;
  82                 dst->st_size  = (Elf64_Xword) sym32->st_size;
  83                 dst->st_info  = ELF64_ST_INFO(ELF32_ST_BIND(sym32->st_info),
  84                     ELF32_ST_TYPE(sym32->st_info));
  85                 dst->st_other = sym32->st_other;
  86                 dst->st_shndx = sym32->st_shndx;
  87         } else {
  88
  89                 sym64 = (Elf64_Sym *) d->d_buf + ndx;
  90
  91                 *dst = *sym64;
  92         }
  93
  94         return (dst);
  95 }
  96
  97 int
  98 gelf_update_sym(Elf_Data *d, int ndx, GElf_Sym *gs)
  99 {
 100         int ec;
 101         Elf *e;
 102         Elf_Scn *scn;
 103         Elf32_Sym *sym32;
 104         Elf64_Sym *sym64;
 105         size_t msz;
 106         uint32_t sh_type;
 107
 108         if (d == NULL || ndx < 0 || gs == NULL ||
 109             (scn = d->d_scn) == NULL ||
 110             (e = scn->s_elf) == NULL) {
 111                 LIBELF_SET_ERROR(ARGUMENT, 0);
 112                 return (0);
 113         }
 114
 115         ec = e->e_class;
 116         assert(ec == ELFCLASS32 || ec == ELFCLASS64);
 117
 118         if (ec == ELFCLASS32)
 119                 sh_type = scn->s_shdr.s_shdr32.sh_type;
 120         else
 121                 sh_type = scn->s_shdr.s_shdr64.sh_type;
 122
 123         if (_libelf_xlate_shtype(sh_type) != ELF_T_SYM) {
 124                 LIBELF_SET_ERROR(ARGUMENT, 0);
 125                 return (0);
 126         }
 127
 128         msz = _libelf_msize(ELF_T_SYM, ec, e->e_version);
 129         assert(msz > 0);
 130
 131         if (msz * ndx >= d->d_size) {
 132                 LIBELF_SET_ERROR(ARGUMENT, 0);
 133                 return (0);
 134         }
 135
 136         if (ec == ELFCLASS32) {
 137                 sym32 = (Elf32_Sym *) d->d_buf + ndx;
 138
 139                 sym32->st_name  = gs->st_name;
 140                 sym32->st_info  = gs->st_info;
 141                 sym32->st_other = gs->st_other;
 142                 sym32->st_shndx = gs->st_shndx;
 143
 144                 LIBELF_COPY_U32(sym32, gs, st_value);
 145                 LIBELF_COPY_U32(sym32, gs, st_size);
 146         } else {
 147                 sym64 = (Elf64_Sym *) d->d_buf + ndx;
 148
 149                 *sym64 = *gs;
 150         }
 151
 152         return (1);
 153 }