usr/src/cmd/sgs/libelf/common/getscn.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 /*
  23  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 /*      Copyright (c) 1988 AT&T */
  28 /*        All Rights Reserved   */
  29
  30 #include "libelf.h"
  31 #include "decl.h"
  32 #include "msg.h"
  33
  34
  35 Elf_Scn *
  36 elf_getscn(Elf * elf, size_t index)
  37 {
  38         Elf_Scn *       s;
  39         Elf_Scn *       prev_s;
  40         size_t          j = index;
  41         size_t          tabsz;
  42
  43         if (elf == 0)
  44                 return (0);
  45
  46         ELFRLOCK(elf)
  47         tabsz = elf->ed_scntabsz;
  48         if (elf->ed_hdscn == 0) {
  49                 ELFUNLOCK(elf)
  50                 ELFWLOCK(elf)
  51                 if ((elf->ed_hdscn == 0) && (_elf_cook(elf) != OK_YES)) {
  52                         ELFUNLOCK(elf);
  53                         return (0);
  54                 }
  55                 ELFUNLOCK(elf);
  56                 ELFRLOCK(elf)
  57         }
  58         /*
  59          * If the section in question is part of a table allocated
  60          * from within _elf_prescn() then we can index straight
  61          * to it.
  62          */
  63         if (index < tabsz) {
  64                 s = &elf->ed_hdscn[index];
  65                 ELFUNLOCK(elf);
  66                 return (s);
  67         }
  68
  69         if (tabsz)
  70                 s = &elf->ed_hdscn[tabsz - 1];
  71         else
  72                 s = elf->ed_hdscn;
  73
  74         for (prev_s = 0; s != 0; prev_s = s, s = s->s_next) {
  75                 if (prev_s) {
  76                         SCNUNLOCK(prev_s)
  77                 }
  78                 SCNLOCK(s)
  79                 if (j == 0) {
  80                         if (s->s_index == index) {
  81                                 SCNUNLOCK(s)
  82                                 ELFUNLOCK(elf);
  83                                 return (s);
  84                         }
  85                         _elf_seterr(EBUG_SCNLIST, 0);
  86                         SCNUNLOCK(s)
  87                         ELFUNLOCK(elf)
  88                         return (0);
  89                 }
  90                 --j;
  91         }
  92         if (prev_s) {
  93                 SCNUNLOCK(prev_s)
  94         }
  95
  96         _elf_seterr(EREQ_NDX, 0);
  97         ELFUNLOCK(elf);
  98         return (0);
  99 }