lib/libelf/libelf_extended.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 <libelf.h>
  31
  32 #include "_libelf.h"
  33
  34 LIBELF_VCSID("$Id$");
  35
  36 /*
  37  * Retrieve section #0, allocating a new section if needed.
  38  */
  39 static Elf_Scn *
  40 _libelf_getscn0(Elf *e)
  41 {
  42         Elf_Scn *s;
  43
  44         if ((s = STAILQ_FIRST(&e->e_u.e_elf.e_scn)) != NULL)
  45                 return (s);
  46
  47         return (_libelf_allocate_scn(e, (size_t) SHN_UNDEF));
  48 }
  49
  50 int
  51 _libelf_setshnum(Elf *e, void *eh, int ec, size_t shnum)
  52 {
  53         Elf_Scn *scn;
  54
  55         if (shnum >= SHN_LORESERVE) {
  56                 if ((scn = _libelf_getscn0(e)) == NULL)
  57                         return (0);
  58
  59                 assert(scn->s_ndx == SHN_UNDEF);
  60
  61                 if (ec == ELFCLASS32)
  62                         scn->s_shdr.s_shdr32.sh_size = shnum;
  63                 else
  64                         scn->s_shdr.s_shdr64.sh_size = shnum;
  65
  66                 (void) elf_flagshdr(scn, ELF_C_SET, ELF_F_DIRTY);
  67
  68                 shnum = 0;
  69         }
  70
  71         if (ec == ELFCLASS32)
  72                 ((Elf32_Ehdr *) eh)->e_shnum = shnum;
  73         else
  74                 ((Elf64_Ehdr *) eh)->e_shnum = shnum;
  75
  76
  77         return (1);
  78 }
  79
  80 int
  81 _libelf_setshstrndx(Elf *e, void *eh, int ec, size_t shstrndx)
  82 {
  83         Elf_Scn *scn;
  84
  85         if (shstrndx >= SHN_LORESERVE) {
  86                 if ((scn = _libelf_getscn0(e)) == NULL)
  87                         return (0);
  88
  89                 assert(scn->s_ndx == SHN_UNDEF);
  90
  91                 if (ec == ELFCLASS32)
  92                         scn->s_shdr.s_shdr32.sh_link = shstrndx;
  93                 else
  94                         scn->s_shdr.s_shdr64.sh_link = shstrndx;
  95
  96                 (void) elf_flagshdr(scn, ELF_C_SET, ELF_F_DIRTY);
  97
  98                 shstrndx = SHN_XINDEX;
  99         }
 100
 101         if (ec == ELFCLASS32)
 102                 ((Elf32_Ehdr *) eh)->e_shstrndx = shstrndx;
 103         else
 104                 ((Elf64_Ehdr *) eh)->e_shstrndx = shstrndx;
 105
 106         return (1);
 107 }
 108
 109 int
 110 _libelf_setphnum(Elf *e, void *eh, int ec, size_t phnum)
 111 {
 112         Elf_Scn *scn;
 113
 114         if (phnum >= PN_XNUM) {
 115                 if ((scn = _libelf_getscn0(e)) == NULL)
 116                         return (0);
 117
 118                 assert(scn->s_ndx == SHN_UNDEF);
 119
 120                 if (ec == ELFCLASS32)
 121                         scn->s_shdr.s_shdr32.sh_info = phnum;
 122                 else
 123                         scn->s_shdr.s_shdr64.sh_info = phnum;
 124
 125                 (void) elf_flagshdr(scn, ELF_C_SET, ELF_F_DIRTY);
 126
 127                 phnum = PN_XNUM;
 128         }
 129
 130         if (ec == ELFCLASS32)
 131                 ((Elf32_Ehdr *) eh)->e_phnum = phnum;
 132         else
 133                 ((Elf64_Ehdr *) eh)->e_phnum = phnum;
 134
 135         return (1);
 136 }