IABSD.fr/src/lib/libelf/libelf_phdr.c

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• Author : jsg
  Date : 2020-05-18 06:46:23
  Hash : 63b93652
  Message : update libelf from elftoolchain r3717 to r3833 ok deraadt@

• lib/libelf/libelf_phdr.c

• /*-
   * Copyright (c) 2006,2008 Joseph Koshy
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in the
   *    documentation and/or other materials provided with the distribution.
   *
   * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
   * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
   * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   * SUCH DAMAGE.
   */
  
  #include <assert.h>
  #include <gelf.h>
  #include <libelf.h>
  #include <stdlib.h>
  
  #include "_libelf.h"
  
  ELFTC_VCSID("$Id: libelf_phdr.c,v 1.3 2020/05/18 06:46:23 jsg Exp $");
  
  void *
  _libelf_getphdr(Elf *e, int ec)
  {
  	size_t phnum;
  	size_t fsz, msz;
  	uint64_t phoff;
  	Elf32_Ehdr *eh32;
  	Elf64_Ehdr *eh64;
  	void *ehdr, *phdr;
  	_libelf_translator_function *xlator;
  
  	assert(ec == ELFCLASS32 || ec == ELFCLASS64);
  
  	if (e == NULL) {
  		LIBELF_SET_ERROR(ARGUMENT, 0);
  		return (NULL);
  	}
  
  	if ((phdr = (ec == ELFCLASS32 ?
  		 (void *) e->e_u.e_elf.e_phdr.e_phdr32 :
  		 (void *) e->e_u.e_elf.e_phdr.e_phdr64)) != NULL)
  		return (phdr);
  
  	/*
  	 * Check the PHDR related fields in the EHDR for sanity.
  	 */
  
  	if ((ehdr = _libelf_ehdr(e, ec, 0)) == NULL)
  		return (NULL);
  
  	phnum = e->e_u.e_elf.e_nphdr;
  
  	if (ec == ELFCLASS32) {
  		eh32      = (Elf32_Ehdr *) ehdr;
  		phoff     = (uint64_t) eh32->e_phoff;
  	} else {
  		eh64      = (Elf64_Ehdr *) ehdr;
  		phoff     = (uint64_t) eh64->e_phoff;
  	}
  
  	fsz = gelf_fsize(e, ELF_T_PHDR, phnum, e->e_version);
  
  	assert(fsz > 0);
  
  	if (phoff + fsz < phoff) {	/* Numeric overflow. */
  		LIBELF_SET_ERROR(HEADER, 0);
  		return (NULL);
  	}
  
  	if ((uint64_t) e->e_rawsize < (phoff + fsz)) {
  		LIBELF_SET_ERROR(HEADER, 0);
  		return (NULL);
  	}
  
  	if ((msz = _libelf_msize(ELF_T_PHDR, ec, EV_CURRENT)) == 0)
  		return (NULL);
  
  	if ((phdr = calloc(phnum, msz)) == NULL) {
  		LIBELF_SET_ERROR(RESOURCE, 0);
  		return (NULL);
  	}
  
  	if (ec == ELFCLASS32)
  		e->e_u.e_elf.e_phdr.e_phdr32 = phdr;
  	else
  		e->e_u.e_elf.e_phdr.e_phdr64 = phdr;
  
  
  	xlator = _libelf_get_translator(ELF_T_PHDR, ELF_TOMEMORY, ec,
  	    _libelf_elfmachine(e));
  	(*xlator)(phdr, phnum * msz, e->e_rawfile + phoff, phnum,
  	    e->e_byteorder != LIBELF_PRIVATE(byteorder));
  
  	return (phdr);
  }
  
  void *
  _libelf_newphdr(Elf *e, int ec, size_t count)
  {
  	void *ehdr, *newphdr, *oldphdr;
  	size_t msz;
  
  	if (e == NULL) {
  		LIBELF_SET_ERROR(ARGUMENT, 0);
  		return (NULL);
  	}
  
  	if ((ehdr = _libelf_ehdr(e, ec, 0)) == NULL) {
  		LIBELF_SET_ERROR(SEQUENCE, 0);
  		return (NULL);
  	}
  
  	assert(e->e_class == ec);
  	assert(ec == ELFCLASS32 || ec == ELFCLASS64);
  	assert(e->e_version == EV_CURRENT);
  
  	if ((msz = _libelf_msize(ELF_T_PHDR, ec, e->e_version)) == 0)
  		return (NULL);
  
  	newphdr = NULL;
  	if (count > 0 && (newphdr = calloc(count, msz)) == NULL) {
  		LIBELF_SET_ERROR(RESOURCE, 0);
  		return (NULL);
  	}
  
  	if (ec == ELFCLASS32) {
  		if ((oldphdr = (void *) e->e_u.e_elf.e_phdr.e_phdr32) != NULL)
  			free(oldphdr);
  		e->e_u.e_elf.e_phdr.e_phdr32 = (Elf32_Phdr *) newphdr;
  	} else {
  		if ((oldphdr = (void *) e->e_u.e_elf.e_phdr.e_phdr64) != NULL)
  			free(oldphdr);
  		e->e_u.e_elf.e_phdr.e_phdr64 = (Elf64_Phdr *) newphdr;
  	}
  
  	e->e_u.e_elf.e_nphdr = count;
  
  	elf_flagphdr(e, ELF_C_SET, ELF_F_DIRTY);
  
  	return (newphdr);
  }