usr/src/cmd/sgs/librtld/common/syms.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 2006 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  *
  26  * Update the symbol table entries:
  27  *
  28  *  o   If addr is non-zero then every symbol entry is updated to indicate the
  29  *      new location to which the object will be mapped.
  30  *
  31  *  o   The address of the `_edata' and `_end' symbols, and their associated
  32  *      section, is updated to reflect any new heap addition.
  33  */
  34 #pragma ident   "%Z%%M% %I%     %E% SMI"
  35
  36 #include        <libelf.h>
  37 #include        <string.h>
  38 #include        "sgs.h"
  39 #include        "machdep.h"
  40 #include        "msg.h"
  41 #include        "_librtld.h"
  42
  43 void
  44 update_sym(Cache *cache, Cache *_cache, Addr edata, Half endx, Addr addr)
  45 {
  46         char    *strs;
  47         Sym     *syms;
  48         Shdr    *shdr;
  49         Xword   symn, cnt;
  50
  51         /*
  52          * Set up to read the symbol table and its associated string table.
  53          */
  54         shdr = _cache->c_shdr;
  55         syms = (Sym *)_cache->c_data->d_buf;
  56         symn = shdr->sh_size / shdr->sh_entsize;
  57
  58         strs = (char *)cache[shdr->sh_link].c_data->d_buf;
  59
  60         /*
  61          * Loop through the symbol table looking for `_end' and `_edata'.
  62          */
  63         for (cnt = 0; cnt < symn; cnt++, syms++) {
  64                 char    *name = strs + syms->st_name;
  65
  66                 if (addr) {
  67                         if (syms->st_value)
  68                                 syms->st_value += addr;
  69                 }
  70
  71                 if ((name[0] != '_') || (name[1] != 'e'))
  72                         continue;
  73                 if (strcmp(name, MSG_ORIG(MSG_SYM_END)) &&
  74                     strcmp(name, MSG_ORIG(MSG_SYM_EDATA)))
  75                         continue;
  76
  77                 syms->st_value = edata + addr;
  78                 if (endx)
  79                         syms->st_shndx = endx;
  80         }
  81 }
  82
  83 int
  84 syminfo(Cache *_cache, Alist **nodirect)
  85 {
  86         Syminfo *info;
  87         Shdr    *shdr;
  88         Word    num, ndx;
  89
  90         shdr = _cache->c_shdr;
  91         info = (Syminfo *)_cache->c_data->d_buf;
  92         num = (Word)(shdr->sh_size / shdr->sh_entsize);
  93
  94         /*
  95          * Traverse the syminfo section recording the index of all nodirect
  96          * symbols.
  97          */
  98         for (ndx = 1, info++; ndx < num; ndx++, info++) {
  99                 if ((info->si_flags & SYMINFO_FLG_NOEXTDIRECT) == 0)
 100                         continue;
 101
 102                 if (alist_append(nodirect, &ndx, sizeof (Word), 20) == 0)
 103                         return (1);
 104         }
 105         return (0);
 106 }