external/bsd/libelf/dist/libelf_phdr.c

   1 /*      $NetBSD: libelf_phdr.c,v 1.2 2009/12/20 23:23:46 thorpej Exp $  */
   2
   3 /*-
   4  * Copyright (c) 2006 Joseph Koshy
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  26  * SUCH DAMAGE.
  27  *
  28  * $FreeBSD: src/lib/libelf/libelf_phdr.c,v 1.2.10.1.2.1 2009/10/25 01:10:29 kensmith Exp $
  29  */
  30
  31 #include <sys/cdefs.h>
  32 /* __FBSDID("$FreeBSD: src/lib/libelf/libelf_phdr.c,v 1.2.10.1.2.1 2009/10/25 01:10:29 kensmith Exp $"); */
  33
  34 #include <assert.h>
  35 #include <gelf.h>
  36 #include <libelf.h>
  37 #include <stdlib.h>
  38
  39 #include "_libelf.h"
  40
  41 void *
  42 _libelf_getphdr(Elf *e, int ec)
  43 {
  44         size_t phnum, phentsize;
  45         size_t fsz, msz;
  46         uint64_t phoff;
  47         Elf32_Ehdr *eh32;
  48         Elf64_Ehdr *eh64;
  49         void *ehdr, *phdr;
  50         void (*xlator)(char *_d, char *_s, size_t _c, int _swap);
  51
  52         assert(ec == ELFCLASS32 || ec == ELFCLASS64);
  53
  54         if (e == NULL) {
  55                 LIBELF_SET_ERROR(ARGUMENT, 0);
  56                 return (NULL);
  57         }
  58
  59         if ((phdr = (ec == ELFCLASS32 ?
  60                  (void *) e->e_u.e_elf.e_phdr.e_phdr32 :
  61                  (void *) e->e_u.e_elf.e_phdr.e_phdr64)) != NULL)
  62                 return (phdr);
  63
  64         /*
  65          * Check the PHDR related fields in the EHDR for sanity.
  66          */
  67
  68         if ((ehdr = _libelf_ehdr(e, ec, 0)) == NULL)
  69                 return (NULL);
  70
  71         phnum = e->e_u.e_elf.e_nphdr;
  72
  73         if (ec == ELFCLASS32) {
  74                 eh32      = (Elf32_Ehdr *) ehdr;
  75                 phentsize = eh32->e_phentsize;
  76                 phoff     = (uint64_t) eh32->e_phoff;
  77         } else {
  78                 eh64      = (Elf64_Ehdr *) ehdr;
  79                 phentsize = eh64->e_phentsize;
  80                 phoff     = (uint64_t) eh64->e_phoff;
  81         }
  82
  83         fsz = gelf_fsize(e, ELF_T_PHDR, phnum, e->e_version);
  84
  85         assert(fsz > 0);
  86
  87         if ((uint64_t) e->e_rawsize < (phoff + fsz)) {
  88                 LIBELF_SET_ERROR(HEADER, 0);
  89                 return (NULL);
  90         }
  91
  92         msz = _libelf_msize(ELF_T_PHDR, ec, EV_CURRENT);
  93
  94         assert(msz > 0);
  95
  96         if ((phdr = calloc(phnum, msz)) == NULL) {
  97                 LIBELF_SET_ERROR(RESOURCE, 0);
  98                 return (NULL);
  99         }
 100
 101         if (ec == ELFCLASS32)
 102                 e->e_u.e_elf.e_phdr.e_phdr32 = phdr;
 103         else
 104                 e->e_u.e_elf.e_phdr.e_phdr64 = phdr;
 105
 106
 107         xlator = _libelf_get_translator(ELF_T_PHDR, ELF_TOMEMORY, ec);
 108         (*xlator)(phdr, e->e_rawfile + phoff, phnum,
 109             e->e_byteorder != _libelf_host_byteorder());
 110
 111         return (phdr);
 112 }
 113
 114 void *
 115 _libelf_newphdr(Elf *e, int ec, size_t count)
 116 {
 117         void *ehdr, *newphdr, *oldphdr;
 118         size_t msz;
 119
 120         if (e == NULL) {
 121                 LIBELF_SET_ERROR(ARGUMENT, 0);
 122                 return (NULL);
 123         }
 124
 125         if ((ehdr = _libelf_ehdr(e, ec, 0)) == NULL) {
 126                 LIBELF_SET_ERROR(SEQUENCE, 0);
 127                 return (NULL);
 128         }
 129
 130         assert(e->e_class == ec);
 131         assert(ec == ELFCLASS32 || ec == ELFCLASS64);
 132         assert(e->e_version == EV_CURRENT);
 133
 134         msz = _libelf_msize(ELF_T_PHDR, ec, e->e_version);
 135
 136         assert(msz > 0);
 137
 138         newphdr = NULL;
 139         if (count > 0 && (newphdr = calloc(count, msz)) == NULL) {
 140                 LIBELF_SET_ERROR(RESOURCE, 0);
 141                 return (NULL);
 142         }
 143
 144         if (ec == ELFCLASS32) {
 145                 if ((oldphdr = (void *) e->e_u.e_elf.e_phdr.e_phdr32) != NULL)
 146                         free(oldphdr);
 147                 e->e_u.e_elf.e_phdr.e_phdr32 = (Elf32_Phdr *) newphdr;
 148         } else {
 149                 if ((oldphdr = (void *) e->e_u.e_elf.e_phdr.e_phdr64) != NULL)
 150                         free(oldphdr);
 151                 e->e_u.e_elf.e_phdr.e_phdr64 = (Elf64_Phdr *) newphdr;
 152         }
 153
 154         e->e_u.e_elf.e_nphdr = count;
 155
 156         elf_flagphdr(e, ELF_C_SET, ELF_F_DIRTY);
 157
 158         return (newphdr);
 159 }