diff options
Diffstat (limited to 'ldso/ldso/hash.c')
| -rw-r--r-- | ldso/ldso/hash.c | 82 |
1 files changed, 57 insertions, 25 deletions
diff --git a/ldso/ldso/hash.c b/ldso/ldso/hash.c index b063d0b79..5711bebaa 100644 --- a/ldso/ldso/hash.c +++ b/ldso/ldso/hash.c @@ -1,21 +1,34 @@ -/* Run an ELF binary on a linux system. - - Copyright (C) 1993-1996, Eric Youngdale. - - This program is free software; you can redistribute it and/or modify - it under the terms of the GNU General Public License as published by - the Free Software Foundation; either version 2, or (at your option) - any later version. - - This program 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 General Public License for more details. - - You should have received a copy of the GNU General Public License - along with this program; if not, write to the Free Software - Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ - +/* vi: set sw=4 ts=4: */ +/* Program to load an ELF binary on a linux system, and run it + * after resolving ELF shared library symbols + * + * Copyright (c) 1994-2000 Eric Youngdale, Peter MacDonald, + * David Engel, Hongjiu Lu and Mitch D'Souza + * Copyright (C) 2001-2002, Erik Andersen + * + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. The name of the above contributors may not be + * used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ /* Various symbol table handling functions, including symbol lookup */ @@ -150,7 +163,7 @@ struct elf_resolve *_dl_add_elf_hash_table(char *libname, */ char *_dl_find_hash(char *name, struct dyn_elf *rpnt1, - struct elf_resolve *f_tpnt, int copyrel) + struct elf_resolve *f_tpnt, enum caller_type caller_type) { struct elf_resolve *tpnt; int si; @@ -172,7 +185,7 @@ char *_dl_find_hash(char *name, struct dyn_elf *rpnt1, that any shared library data symbols referenced in the executable will be seen at the same address by the executable, shared libraries and dynamically loaded code. -Rob Ryan (robr@cmu.edu) */ - if (!copyrel && rpnt1) { + if (copyrel!=caller_type && rpnt1) { first = (*_dl_symbol_tables); first.next = rpnt1; rpnt1 = (&first); @@ -247,11 +260,12 @@ char *_dl_find_hash(char *name, struct dyn_elf *rpnt1, pnt = strtab + symtab[si].st_name; if (_dl_strcmp(pnt, name) == 0 && - (ELF32_ST_TYPE(symtab[si].st_info) == STT_FUNC || - ELF32_ST_TYPE(symtab[si].st_info) == STT_NOTYPE || - ELF32_ST_TYPE(symtab[si].st_info) == STT_OBJECT) && - symtab[si].st_value != 0 && - symtab[si].st_shndx != 0) { + symtab[si].st_value != 0) + { + if ((ELF32_ST_TYPE(symtab[si].st_info) == STT_FUNC || + ELF32_ST_TYPE(symtab[si].st_info) == STT_NOTYPE || + ELF32_ST_TYPE(symtab[si].st_info) == STT_OBJECT) && + symtab[si].st_shndx != SHN_UNDEF) { /* Here we make sure that we find a module where the symbol is * actually defined. @@ -284,6 +298,24 @@ char *_dl_find_hash(char *name, struct dyn_elf *rpnt1, default: /* Do local symbols need to be examined? */ break; } + } + /* + * References to the address of a function from an executable file and + * the shared objects associated with it might not resolve to the same + * value. To allow comparisons of function addresses we must resolve + * to the address of the plt entry of the executable instead of the + * real function address. + * see "TIS ELF Specification Version 1.2, Book 3, A-11 (Function + * Adresses) + */ + if (resolver != caller_type && + NULL==f_tpnt && /*trick: don't handle R_??_JMP_SLOT reloc type*/ + tpnt->libtype == elf_executable && + ELF32_ST_TYPE(symtab[si].st_info) == STT_FUNC && + symtab[si].st_shndx == SHN_UNDEF) + { + return (char*)symtab[si].st_value; + } } } } |