Update.
[glibc.git] / elf / dl-addr.c
blob14bff06f1386af76aa85fc9a86c185af616cb9c8
1 /* Locate the shared object symbol nearest a given address.
2 Copyright (C) 1996, 1997, 1998, 1999 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Library General Public License as
7 published by the Free Software Foundation; either version 2 of the
8 License, or (at your option) any later version.
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Library General Public License for more details.
15 You should have received a copy of the GNU Library General Public
16 License along with the GNU C Library; see the file COPYING.LIB. If not,
17 write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
18 Boston, MA 02111-1307, USA. */
20 #include <dlfcn.h>
21 #include <stddef.h>
22 #include <elf/ldsodefs.h>
25 int
26 internal_function
27 _dl_addr (const void *address, Dl_info *info)
29 const ElfW(Addr) addr = (ElfW(Addr)) address;
30 struct link_map *l, *match;
31 const ElfW(Sym) *symtab, *matchsym;
32 const char *strtab;
34 /* Find the highest-addressed object that ADDRESS is not below. */
35 match = NULL;
36 for (l = _dl_loaded; l; l = l->l_next)
37 if (l->l_addr != 0 /* Make sure we do not currently set this map up
38 in this moment. */
39 && addr >= l->l_addr && (!match || match->l_addr < l->l_addr))
40 match = l;
42 if (match)
44 /* We know ADDRESS lies within MATCH if in any shared object.
45 Make sure it isn't past the end of MATCH's segments. */
46 size_t n = match->l_phnum;
47 if (n > 0)
50 --n;
51 while (match->l_phdr[n].p_type != PT_LOAD);
52 if (addr >= (match->l_addr +
53 match->l_phdr[n].p_vaddr + match->l_phdr[n].p_memsz))
54 /* Off the end of the highest-addressed shared object. */
55 return 0;
58 else
59 return 0;
61 /* Now we know what object the address lies in. */
62 info->dli_fname = match->l_name;
63 info->dli_fbase = (void *) match->l_addr;
65 symtab = (const void *) match->l_info[DT_SYMTAB]->d_un.d_ptr;
66 strtab = (const void *) match->l_info[DT_STRTAB]->d_un.d_ptr;
68 /* We assume that the string table follows the symbol table, because
69 there is no way in ELF to know the size of the dynamic symbol table!! */
70 for (matchsym = NULL; (void *) symtab < (void *) strtab; ++symtab)
71 if (addr >= match->l_addr + symtab->st_value
72 && (!matchsym
73 || (matchsym->st_value < symtab->st_value
74 && (ELFW(ST_BIND) (symtab->st_info) == STB_GLOBAL
75 || ELFW(ST_BIND) (symtab->st_info) == STB_WEAK))))
76 matchsym = symtab;
78 if (matchsym)
80 /* We found a symbol close by. Fill in its name and exact address. */
81 info->dli_sname = strtab + matchsym->st_name;
82 info->dli_saddr = (void *) (match->l_addr + matchsym->st_value);
84 else
86 /* No symbol matches. We return only the containing object. */
87 info->dli_sname = NULL;
88 info->dli_saddr = NULL;
91 return 1;