usr/src/cmd/sgs/libelf/common/getshnum.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 /*
  22  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
  23  * Use is subject to license terms.
  24  */
  25
  26 #include <string.h>
  27 #include <gelf.h>
  28 #include <decl.h>
  29 #include <msg.h>
  30
  31
  32 /*
  33  * Return number of entries in the section header array, taking
  34  * extended headers into account.
  35  *
  36  * elf_getshnum() and elf_getshstrndx() were defined during the 2002 gABI
  37  * meetings. They were supposed to return -1 for failure, and 0 for success.
  38  * Our manpage documented them as such, but we then implemented them to
  39  * return 0 for failure and 1 for success. This makes elf_getshnum() and
  40  * elf_getshstrnum() non-portable to systems that implement the 2002 gABI
  41  * definition.
  42  *
  43  * In 2005, the manpage was modified to match the code.
  44  * In 2009, the discrepency was identified. elf_getshdrnum() and
  45  * elf_getshdrstrndx() were created to provide a portable implementation.
  46  * The older two functions are considered to be obsolete, and are retained
  47  * for backward compatability.
  48  */
  49
  50 int
  51 elf_getshdrnum(Elf *elf, size_t *shnum)
  52 {
  53         GElf_Ehdr       ehdr;
  54         Elf_Scn         *scn;
  55         GElf_Shdr       shdr0;
  56
  57         if (gelf_getehdr(elf, &ehdr) == 0)
  58                 return (-1);
  59         if (ehdr.e_shnum > 0) {
  60                 *shnum = ehdr.e_shnum;
  61                 return (0);
  62         }
  63         if ((ehdr.e_shnum == 0) && (ehdr.e_shoff == 0)) {
  64                 *shnum = 0;
  65                 return (0);
  66         }
  67         if ((scn = elf_getscn(elf, 0)) == 0)
  68                 return (-1);
  69         if (gelf_getshdr(scn, &shdr0) == 0)
  70                 return (-1);
  71         *shnum = shdr0.sh_size;
  72         return (0);
  73 }
  74
  75 int
  76 elf_getshnum(Elf *elf, size_t *shnum)
  77 {
  78         return (elf_getshdrnum(elf, shnum) == 0);
  79 }