From a2b934be254cad6c725baf738f0d97df985522c6 Mon Sep 17 00:00:00 2001 From: Roland McGrath Date: Tue, 4 Jun 1996 09:29:39 +0000 Subject: * stdio-common/vfprintf.c [USE_IN_LIBIO] (size_t): Don't define as macro. _IO_size_t is just an alias for the real size_t anyway. * elf/Makefile (libdl-routines): Add dladdr. * elf/dladdr.c: New file. * elf/dlfcn.h (Dl_info): New typedef. (dladdr): Declare it. --- elf/dladdr.c | 88 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 88 insertions(+) create mode 100644 elf/dladdr.c (limited to 'elf/dladdr.c') diff --git a/elf/dladdr.c b/elf/dladdr.c new file mode 100644 index 0000000000..166952ac46 --- /dev/null +++ b/elf/dladdr.c @@ -0,0 +1,88 @@ +/* dladdr -- Locate the shared object symbol nearest a given address. +Copyright (C) 1996 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 Library General Public License as +published by the Free Software Foundation; either version 2 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 +Library General Public License for more details. + +You should have received a copy of the GNU Library General Public +License along with the GNU C Library; see the file COPYING.LIB. If +not, write to the Free Software Foundation, Inc., 675 Mass Ave, +Cambridge, MA 02139, USA. */ + +#include +#include +#include +#include + + +int +dladdr (void *address, Dl_info *info) +{ + const Elf32_Addr addr = (Elf32_Addr) address; + struct link_map *l, *match; + const Elf32_Sym *symtab, *matchsym; + const char *strtab; + Elf32_Word symidx; + + /* Find the highest-addressed object that ADDRESS is not below. */ + match = NULL; + for (l = _dl_loaded; l; l = l->l_next) + if (addr >= l->l_addr && !match || match->l_addr < l->l_addr) + match = l; + + if (match) + { + /* We know ADDRESS lies within MATCH if in any shared object. + Make sure it isn't past the end of MATCH's segments. */ + size_t n = match->l_phnum; + do + --n; + while (match->l_phdr[n].p_type != PT_LOAD); + if (addr >= (match->l_addr + + match->l_phdr[n].p_vaddr + match->l_phdr[n].p_memsz)) + /* Off the end of the highest-addressed shared object. */ + return 0; + } + else + return 0; + + /* Now we know what object the address lies in. */ + info->dli_fname = match->l_name; + info->dli_fbase = (void *) match->l_addr; + + symtab = ((void *) match->l_addr + match->l_info[DT_SYMTAB]->d_un.d_ptr); + strtab = ((void *) match->l_addr + match->l_info[DT_STRTAB]->d_un.d_ptr); + + /* 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 *) strtab; ++symtab) + if (addr >= match->l_addr + symtab->st_value && !matchsym || + matchsym->st_value < symtab->st_value && + ELF32_ST_BIND (symtab->st_info) == STB_GLOBAL || + ELF32_ST_BIND (symtab->st_info) == STB_WEAK) + matchsym = 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; +} + -- cgit v1.2.3