131 lines
4.2 KiB
C
131 lines
4.2 KiB
C
/* Locate the shared object symbol nearest a given address.
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Copyright (C) 1996-2003, 2004 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, write to the Free
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Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
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02111-1307 USA. */
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#include <dlfcn.h>
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#include <stddef.h>
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#include <ldsodefs.h>
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int
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internal_function
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_dl_addr (const void *address, Dl_info *info,
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struct link_map **mapp, const ElfW(Sym) **symbolp)
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{
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const ElfW(Addr) addr = DL_LOOKUP_ADDRESS (address);
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struct link_map *match;
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const ElfW(Sym) *symtab, *matchsym, *symtabend;
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const char *strtab;
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ElfW(Word) strtabsize;
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/* Protect against concurrent loads and unloads. */
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__rtld_lock_lock_recursive (GL(dl_load_lock));
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/* Find the highest-addressed object that ADDRESS is not below. */
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match = NULL;
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for (Lmid_t ns = 0; ns < DL_NNS; ++ns)
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for (struct link_map *l = GL(dl_ns)[ns]._ns_loaded; l; l = l->l_next)
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if (addr >= l->l_map_start && addr < l->l_map_end)
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{
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/* We know ADDRESS lies within L if in any shared object.
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Make sure it isn't past the end of L's segments. */
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size_t n = l->l_phnum;
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if (n > 0)
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{
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do
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--n;
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while (l->l_phdr[n].p_type != PT_LOAD);
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if (addr >= (l->l_addr +
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l->l_phdr[n].p_vaddr + l->l_phdr[n].p_memsz))
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/* Off the end of the highest-addressed shared object. */
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continue;
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}
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match = l;
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break;
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}
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int result = 0;
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if (match != NULL)
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{
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/* Now we know what object the address lies in. */
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info->dli_fname = match->l_name;
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info->dli_fbase = (void *) match->l_map_start;
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/* If this is the main program the information is incomplete. */
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if (__builtin_expect (match->l_name[0], 'a') == '\0'
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&& match->l_type == lt_executable)
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info->dli_fname = _dl_argv[0];
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symtab = (const void *) D_PTR (match, l_info[DT_SYMTAB]);
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strtab = (const void *) D_PTR (match, l_info[DT_STRTAB]);
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strtabsize = match->l_info[DT_STRSZ]->d_un.d_val;
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if (match->l_info[DT_HASH] != NULL)
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symtabend = (symtab
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+ ((Elf_Symndx *) D_PTR (match, l_info[DT_HASH]))[1]);
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else
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/* There is no direct way to determine the number of symbols in the
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dynamic symbol table and no hash table is present. The ELF
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binary is ill-formed but what shall we do? Use the beginning of
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the string table which generally follows the symbol table. */
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symtabend = (const ElfW(Sym) *) strtab;
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/* We assume that the string table follows the symbol table,
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because there is no way in ELF to know the size of the
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dynamic symbol table!! */
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for (matchsym = NULL; (void *) symtab < (void *) symtabend; ++symtab)
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if (addr >= match->l_addr + symtab->st_value
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&& ((symtab->st_size == 0
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&& addr == match->l_addr + symtab->st_value)
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|| addr < match->l_addr + symtab->st_value + symtab->st_size)
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&& symtab->st_name < strtabsize
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&& (matchsym == NULL || matchsym->st_value < symtab->st_value)
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&& (ELFW(ST_BIND) (symtab->st_info) == STB_GLOBAL
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|| ELFW(ST_BIND) (symtab->st_info) == STB_WEAK))
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matchsym = (ElfW(Sym) *) symtab;
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if (mapp)
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*mapp = match;
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if (symbolp)
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*symbolp = matchsym;
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if (matchsym)
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{
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/* We found a symbol close by. Fill in its name and exact
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address. */
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info->dli_sname = strtab + matchsym->st_name;
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info->dli_saddr = (void *) (match->l_addr + matchsym->st_value);
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}
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else
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{
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/* No symbol matches. We return only the containing object. */
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info->dli_sname = NULL;
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info->dli_saddr = NULL;
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}
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result = 1;
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}
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__rtld_lock_unlock_recursive (GL(dl_load_lock));
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return result;
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}
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libc_hidden_def (_dl_addr)
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