usr/src/cmd/mdb/tools/findfp/common/findsym.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, Version 1.0 only
   6  * (the "License").  You may not use this file except in compliance
   7  * with the License.
   8  *
   9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  10  * or http://www.opensolaris.org/os/licensing.
  11  * See the License for the specific language governing permissions
  12  * and limitations under the License.
  13  *
  14  * When distributing Covered Code, include this CDDL HEADER in each
  15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  16  * If applicable, add the following below this CDDL HEADER, with the
  17  * fields enclosed by brackets "[]" replaced with your own identifying
  18  * information: Portions Copyright [yyyy] [name of copyright owner]
  19  *
  20  * CDDL HEADER END
  21  */
  22 /*
  23  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 #pragma ident   "%Z%%M% %I%     %E% SMI"
  28
  29 #include <stdio.h>
  30 #include <string.h>
  31 #include <libelf.h>
  32 #include <gelf.h>
  33
  34 #include <findfp.h>
  35 #include <util.h>
  36
  37 int
  38 findelfsym(Elf *elf, uintptr_t addr, char **symnamep, offset_t *offp)
  39 {
  40         Elf_Data *symtab;
  41         GElf_Shdr shdr;
  42         Elf_Scn *scn;
  43         int symtabidx, nent, i;
  44
  45         if ((symtabidx = findelfsecidx(elf, ".symtab")) < 0)
  46                 elfdie("failed to find .symtab\n");
  47
  48         if ((scn = elf_getscn(elf, symtabidx)) == NULL ||
  49             gelf_getshdr(scn, &shdr) == NULL ||
  50             (symtab = elf_getdata(scn, NULL)) == NULL)
  51                 elfdie("failed to read .symtab");
  52
  53         nent = shdr.sh_size / shdr.sh_entsize;
  54
  55         for (i = 0; i < nent; i++) {
  56                 GElf_Sym sym;
  57
  58                 if (gelf_getsym(symtab, i, &sym) == NULL)
  59                         elfdie("failed to get symbol at idx %d", i);
  60
  61                 if ((GELF_ST_TYPE(sym.st_info) != STT_FUNC &&
  62                     GELF_ST_TYPE(sym.st_info) != STT_OBJECT) ||
  63                     sym.st_shndx == SHN_UNDEF)
  64                         continue;
  65
  66                 if (addr - sym.st_value < sym.st_size) {
  67                         /* matched */
  68                         if ((*symnamep = elf_strptr(elf, shdr.sh_link,
  69                             sym.st_name)) == NULL)
  70                                 elfdie("failed to get name for sym %d", i);
  71                         *offp = addr - sym.st_value;
  72                         return (1);
  73                 }
  74         }
  75
  76         return (0);
  77 }