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/* Locate the shared object symbol nearest a given address.
Copyright (C) 1996-2000, 2001, 2002 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#include <dlfcn.h>
#include <stddef.h>
#include <ldsodefs.h>
int
internal_function
_dl_addr (const void *address, Dl_info *info)
{
const ElfW(Addr) addr = DL_LOOKUP_ADDRESS (address);
struct link_map *l, *match;
const ElfW(Sym) *symtab, *matchsym, *symtabend;
const char *strtab;
ElfW(Word) strtabsize;
/* Find the highest-addressed object that ADDRESS is not below. */
match = NULL;
for (l = GL(dl_loaded); l; l = l->l_next)
if (addr >= l->l_map_start && addr < l->l_map_end)
{
/* We know ADDRESS lies within L if in any shared object.
Make sure it isn't past the end of L's segments. */
size_t n = l->l_phnum;
if (n > 0)
{
do
--n;
while (l->l_phdr[n].p_type != PT_LOAD);
if (addr >= (l->l_addr +
l->l_phdr[n].p_vaddr + l->l_phdr[n].p_memsz))
/* Off the end of the highest-addressed shared object. */
continue;
}
match = l;
break;
}
if (match == NULL)
return 0;
/* Now we know what object the address lies in. */
info->dli_fname = match->l_name;
info->dli_fbase = (void *) match->l_map_start;
/* If this is the main program the information is incomplete. */
if (__builtin_expect (l->l_name[0], 'a') == '\0'
&& l->l_type == lt_executable)
info->dli_fname = _dl_argv[0];
symtab = (const void *) D_PTR (match, l_info[DT_SYMTAB]);
strtab = (const void *) D_PTR (match, l_info[DT_STRTAB]);
strtabsize = match->l_info[DT_STRSZ]->d_un.d_val;
if (match->l_info[DT_HASH] != NULL)
symtabend = symtab + ((Elf_Symndx *) D_PTR (match, l_info[DT_HASH]))[1];
else
/* There is no direct way to determine the number of symbols in the
dynamic symbol table and no hash table is present. The ELF
binary is ill-formed but what shall we do? Use the beginning of
the string table which generally follows the symbol table. */
symtabend = (const ElfW(Sym) *) strtab;
/* We assume that the string table follows the symbol table, because
there is no way in ELF to know the size of the dynamic symbol table!! */
for (matchsym = NULL; (void *) symtab < (void *) symtabend; ++symtab)
if (addr >= match->l_addr + symtab->st_value
&& ((symtab->st_size == 0 && addr == match->l_addr + symtab->st_value)
|| addr < match->l_addr + symtab->st_value + symtab->st_size)
&& symtab->st_name < strtabsize
&& (matchsym == NULL || matchsym->st_value < symtab->st_value)
&& (ELFW(ST_BIND) (symtab->st_info) == STB_GLOBAL
|| ELFW(ST_BIND) (symtab->st_info) == STB_WEAK))
matchsym = (ElfW(Sym) *) symtab;
if (matchsym)
{
/* We found a symbol close by. Fill in its name and exact address. */
info->dli_sname = strtab + matchsym->st_name;
info->dli_saddr = (void *) (match->l_addr + matchsym->st_value);
}
else
{
/* No symbol matches. We return only the containing object. */
info->dli_sname = NULL;
info->dli_saddr = NULL;
}
return 1;
}
libc_hidden_def (_dl_addr)
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