contrib/elftoolchain/libelf/libelf_phdr.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 <assert.h>
  28 #include <gelf.h>
  29 #include <libelf.h>
  30 #include <stdlib.h>
  31
  32 #include "_libelf.h"
  33
  34 ELFTC_VCSID("$Id: libelf_phdr.c 3174 2015-03-27 17:13:41Z emaste $");
  35
  36 void *
  37 _libelf_getphdr(Elf *e, int ec)
  38 {
  39         size_t phnum;
  40         size_t fsz, msz;
  41         uint64_t phoff;
  42         Elf32_Ehdr *eh32;
  43         Elf64_Ehdr *eh64;
  44         void *ehdr, *phdr;
  45         int (*xlator)(unsigned char *_d, size_t _dsz, unsigned char *_s,
  46             size_t _c, int _swap);
  47
  48         assert(ec == ELFCLASS32 || ec == ELFCLASS64);
  49
  50         if (e == NULL) {
  51                 LIBELF_SET_ERROR(ARGUMENT, 0);
  52                 return (NULL);
  53         }
  54
  55         if ((phdr = (ec == ELFCLASS32 ?
  56                  (void *) e->e_u.e_elf.e_phdr.e_phdr32 :
  57                  (void *) e->e_u.e_elf.e_phdr.e_phdr64)) != NULL)
  58                 return (phdr);
  59
  60         /*
  61          * Check the PHDR related fields in the EHDR for sanity.
  62          */
  63
  64         if ((ehdr = _libelf_ehdr(e, ec, 0)) == NULL)
  65                 return (NULL);
  66
  67         phnum = e->e_u.e_elf.e_nphdr;
  68
  69         if (ec == ELFCLASS32) {
  70                 eh32      = (Elf32_Ehdr *) ehdr;
  71                 phoff     = (uint64_t) eh32->e_phoff;
  72         } else {
  73                 eh64      = (Elf64_Ehdr *) ehdr;
  74                 phoff     = (uint64_t) eh64->e_phoff;
  75         }
  76
  77         fsz = gelf_fsize(e, ELF_T_PHDR, phnum, e->e_version);
  78
  79         assert(fsz > 0);
  80
  81         if ((uint64_t) e->e_rawsize < (phoff + fsz)) {
  82                 LIBELF_SET_ERROR(HEADER, 0);
  83                 return (NULL);
  84         }
  85
  86         msz = _libelf_msize(ELF_T_PHDR, ec, EV_CURRENT);
  87
  88         assert(msz > 0);
  89
  90         if ((phdr = calloc(phnum, msz)) == NULL) {
  91                 LIBELF_SET_ERROR(RESOURCE, 0);
  92                 return (NULL);
  93         }
  94
  95         if (ec == ELFCLASS32)
  96                 e->e_u.e_elf.e_phdr.e_phdr32 = phdr;
  97         else
  98                 e->e_u.e_elf.e_phdr.e_phdr64 = phdr;
  99
 100
 101         xlator = _libelf_get_translator(ELF_T_PHDR, ELF_TOMEMORY, ec);
 102         (*xlator)(phdr, phnum * msz, e->e_rawfile + phoff, phnum,
 103             e->e_byteorder != LIBELF_PRIVATE(byteorder));
 104
 105         return (phdr);
 106 }
 107
 108 void *
 109 _libelf_newphdr(Elf *e, int ec, size_t count)
 110 {
 111         void *ehdr, *newphdr, *oldphdr;
 112         size_t msz;
 113
 114         if (e == NULL) {
 115                 LIBELF_SET_ERROR(ARGUMENT, 0);
 116                 return (NULL);
 117         }
 118
 119         if ((ehdr = _libelf_ehdr(e, ec, 0)) == NULL) {
 120                 LIBELF_SET_ERROR(SEQUENCE, 0);
 121                 return (NULL);
 122         }
 123
 124         assert(e->e_class == ec);
 125         assert(ec == ELFCLASS32 || ec == ELFCLASS64);
 126         assert(e->e_version == EV_CURRENT);
 127
 128         msz = _libelf_msize(ELF_T_PHDR, ec, e->e_version);
 129
 130         assert(msz > 0);
 131
 132         newphdr = NULL;
 133         if (count > 0 && (newphdr = calloc(count, msz)) == NULL) {
 134                 LIBELF_SET_ERROR(RESOURCE, 0);
 135                 return (NULL);
 136         }
 137
 138         if (ec == ELFCLASS32) {
 139                 if ((oldphdr = (void *) e->e_u.e_elf.e_phdr.e_phdr32) != NULL)
 140                         free(oldphdr);
 141                 e->e_u.e_elf.e_phdr.e_phdr32 = (Elf32_Phdr *) newphdr;
 142         } else {
 143                 if ((oldphdr = (void *) e->e_u.e_elf.e_phdr.e_phdr64) != NULL)
 144                         free(oldphdr);
 145                 e->e_u.e_elf.e_phdr.e_phdr64 = (Elf64_Phdr *) newphdr;
 146         }
 147
 148         e->e_u.e_elf.e_nphdr = count;
 149
 150         elf_flagphdr(e, ELF_C_SET, ELF_F_DIRTY);
 151
 152         return (newphdr);
 153 }