125b3c049e70834cf33790a28643ab058b507b35cBen Cheng/* Relocate debug information. 225b3c049e70834cf33790a28643ab058b507b35cBen Cheng Copyright (C) 2005-2010 Red Hat, Inc. 325b3c049e70834cf33790a28643ab058b507b35cBen Cheng This file is part of Red Hat elfutils. 425b3c049e70834cf33790a28643ab058b507b35cBen Cheng 525b3c049e70834cf33790a28643ab058b507b35cBen Cheng Red Hat elfutils is free software; you can redistribute it and/or modify 625b3c049e70834cf33790a28643ab058b507b35cBen Cheng it under the terms of the GNU General Public License as published by the 725b3c049e70834cf33790a28643ab058b507b35cBen Cheng Free Software Foundation; version 2 of the License. 825b3c049e70834cf33790a28643ab058b507b35cBen Cheng 925b3c049e70834cf33790a28643ab058b507b35cBen Cheng Red Hat elfutils is distributed in the hope that it will be useful, but 1025b3c049e70834cf33790a28643ab058b507b35cBen Cheng WITHOUT ANY WARRANTY; without even the implied warranty of 1125b3c049e70834cf33790a28643ab058b507b35cBen Cheng MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 1225b3c049e70834cf33790a28643ab058b507b35cBen Cheng General Public License for more details. 1325b3c049e70834cf33790a28643ab058b507b35cBen Cheng 1425b3c049e70834cf33790a28643ab058b507b35cBen Cheng You should have received a copy of the GNU General Public License along 1525b3c049e70834cf33790a28643ab058b507b35cBen Cheng with Red Hat elfutils; if not, write to the Free Software Foundation, 1625b3c049e70834cf33790a28643ab058b507b35cBen Cheng Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301 USA. 1725b3c049e70834cf33790a28643ab058b507b35cBen Cheng 1825b3c049e70834cf33790a28643ab058b507b35cBen Cheng In addition, as a special exception, Red Hat, Inc. gives You the 1925b3c049e70834cf33790a28643ab058b507b35cBen Cheng additional right to link the code of Red Hat elfutils with code licensed 2025b3c049e70834cf33790a28643ab058b507b35cBen Cheng under any Open Source Initiative certified open source license 2125b3c049e70834cf33790a28643ab058b507b35cBen Cheng (http://www.opensource.org/licenses/index.php) which requires the 2225b3c049e70834cf33790a28643ab058b507b35cBen Cheng distribution of source code with any binary distribution and to 2325b3c049e70834cf33790a28643ab058b507b35cBen Cheng distribute linked combinations of the two. Non-GPL Code permitted under 2425b3c049e70834cf33790a28643ab058b507b35cBen Cheng this exception must only link to the code of Red Hat elfutils through 2525b3c049e70834cf33790a28643ab058b507b35cBen Cheng those well defined interfaces identified in the file named EXCEPTION 2625b3c049e70834cf33790a28643ab058b507b35cBen Cheng found in the source code files (the "Approved Interfaces"). The files 2725b3c049e70834cf33790a28643ab058b507b35cBen Cheng of Non-GPL Code may instantiate templates or use macros or inline 2825b3c049e70834cf33790a28643ab058b507b35cBen Cheng functions from the Approved Interfaces without causing the resulting 2925b3c049e70834cf33790a28643ab058b507b35cBen Cheng work to be covered by the GNU General Public License. Only Red Hat, 3025b3c049e70834cf33790a28643ab058b507b35cBen Cheng Inc. may make changes or additions to the list of Approved Interfaces. 3125b3c049e70834cf33790a28643ab058b507b35cBen Cheng Red Hat's grant of this exception is conditioned upon your not adding 3225b3c049e70834cf33790a28643ab058b507b35cBen Cheng any new exceptions. If you wish to add a new Approved Interface or 3325b3c049e70834cf33790a28643ab058b507b35cBen Cheng exception, please contact Red Hat. You must obey the GNU General Public 3425b3c049e70834cf33790a28643ab058b507b35cBen Cheng License in all respects for all of the Red Hat elfutils code and other 3525b3c049e70834cf33790a28643ab058b507b35cBen Cheng code used in conjunction with Red Hat elfutils except the Non-GPL Code 3625b3c049e70834cf33790a28643ab058b507b35cBen Cheng covered by this exception. If you modify this file, you may extend this 3725b3c049e70834cf33790a28643ab058b507b35cBen Cheng exception to your version of the file, but you are not obligated to do 3825b3c049e70834cf33790a28643ab058b507b35cBen Cheng so. If you do not wish to provide this exception without modification, 3925b3c049e70834cf33790a28643ab058b507b35cBen Cheng you must delete this exception statement from your version and license 4025b3c049e70834cf33790a28643ab058b507b35cBen Cheng this file solely under the GPL without exception. 4125b3c049e70834cf33790a28643ab058b507b35cBen Cheng 4225b3c049e70834cf33790a28643ab058b507b35cBen Cheng Red Hat elfutils is an included package of the Open Invention Network. 4325b3c049e70834cf33790a28643ab058b507b35cBen Cheng An included package of the Open Invention Network is a package for which 4425b3c049e70834cf33790a28643ab058b507b35cBen Cheng Open Invention Network licensees cross-license their patents. No patent 4525b3c049e70834cf33790a28643ab058b507b35cBen Cheng license is granted, either expressly or impliedly, by designation as an 4625b3c049e70834cf33790a28643ab058b507b35cBen Cheng included package. Should you wish to participate in the Open Invention 4725b3c049e70834cf33790a28643ab058b507b35cBen Cheng Network licensing program, please visit www.openinventionnetwork.com 4825b3c049e70834cf33790a28643ab058b507b35cBen Cheng <http://www.openinventionnetwork.com>. */ 4925b3c049e70834cf33790a28643ab058b507b35cBen Cheng 5025b3c049e70834cf33790a28643ab058b507b35cBen Cheng#include "libdwflP.h" 5125b3c049e70834cf33790a28643ab058b507b35cBen Cheng 5225b3c049e70834cf33790a28643ab058b507b35cBen Chengtypedef uint8_t GElf_Byte; 5325b3c049e70834cf33790a28643ab058b507b35cBen Cheng 5425b3c049e70834cf33790a28643ab058b507b35cBen Cheng/* Adjust *VALUE to add the load address of the SHNDX section. 5525b3c049e70834cf33790a28643ab058b507b35cBen Cheng We update the section header in place to cache the result. */ 5625b3c049e70834cf33790a28643ab058b507b35cBen Cheng 5725b3c049e70834cf33790a28643ab058b507b35cBen ChengDwfl_Error 5825b3c049e70834cf33790a28643ab058b507b35cBen Chenginternal_function 5925b3c049e70834cf33790a28643ab058b507b35cBen Cheng__libdwfl_relocate_value (Dwfl_Module *mod, Elf *elf, size_t *shstrndx, 6025b3c049e70834cf33790a28643ab058b507b35cBen Cheng Elf32_Word shndx, GElf_Addr *value) 6125b3c049e70834cf33790a28643ab058b507b35cBen Cheng{ 6225b3c049e70834cf33790a28643ab058b507b35cBen Cheng assert (mod->e_type == ET_REL); 6325b3c049e70834cf33790a28643ab058b507b35cBen Cheng 6425b3c049e70834cf33790a28643ab058b507b35cBen Cheng Elf_Scn *refscn = elf_getscn (elf, shndx); 6525b3c049e70834cf33790a28643ab058b507b35cBen Cheng GElf_Shdr refshdr_mem, *refshdr = gelf_getshdr (refscn, &refshdr_mem); 6625b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (refshdr == NULL) 6725b3c049e70834cf33790a28643ab058b507b35cBen Cheng return DWFL_E_LIBELF; 6825b3c049e70834cf33790a28643ab058b507b35cBen Cheng 6925b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (refshdr->sh_addr == 0 && (refshdr->sh_flags & SHF_ALLOC)) 7025b3c049e70834cf33790a28643ab058b507b35cBen Cheng { 7125b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* This is a loaded section. Find its actual 7225b3c049e70834cf33790a28643ab058b507b35cBen Cheng address and update the section header. */ 7325b3c049e70834cf33790a28643ab058b507b35cBen Cheng 7425b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (*shstrndx == SHN_UNDEF 7525b3c049e70834cf33790a28643ab058b507b35cBen Cheng && unlikely (elf_getshdrstrndx (elf, shstrndx) < 0)) 7625b3c049e70834cf33790a28643ab058b507b35cBen Cheng return DWFL_E_LIBELF; 7725b3c049e70834cf33790a28643ab058b507b35cBen Cheng 7825b3c049e70834cf33790a28643ab058b507b35cBen Cheng const char *name = elf_strptr (elf, *shstrndx, refshdr->sh_name); 7925b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (unlikely (name == NULL)) 8025b3c049e70834cf33790a28643ab058b507b35cBen Cheng return DWFL_E_LIBELF; 8125b3c049e70834cf33790a28643ab058b507b35cBen Cheng 8225b3c049e70834cf33790a28643ab058b507b35cBen Cheng if ((*mod->dwfl->callbacks->section_address) (MODCB_ARGS (mod), 8325b3c049e70834cf33790a28643ab058b507b35cBen Cheng name, shndx, refshdr, 8425b3c049e70834cf33790a28643ab058b507b35cBen Cheng &refshdr->sh_addr)) 8525b3c049e70834cf33790a28643ab058b507b35cBen Cheng return CBFAIL; 8625b3c049e70834cf33790a28643ab058b507b35cBen Cheng 8725b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (refshdr->sh_addr == (Dwarf_Addr) -1l) 8825b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* The callback indicated this section wasn't really loaded but we 8925b3c049e70834cf33790a28643ab058b507b35cBen Cheng don't really care. */ 9025b3c049e70834cf33790a28643ab058b507b35cBen Cheng refshdr->sh_addr = 0; /* Make no adjustment below. */ 9125b3c049e70834cf33790a28643ab058b507b35cBen Cheng 9225b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* Update the in-core file's section header to show the final 9325b3c049e70834cf33790a28643ab058b507b35cBen Cheng load address (or unloadedness). This serves as a cache, 9425b3c049e70834cf33790a28643ab058b507b35cBen Cheng so we won't get here again for the same section. */ 9525b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (likely (refshdr->sh_addr != 0) 9625b3c049e70834cf33790a28643ab058b507b35cBen Cheng && unlikely (! gelf_update_shdr (refscn, refshdr))) 9725b3c049e70834cf33790a28643ab058b507b35cBen Cheng return DWFL_E_LIBELF; 9825b3c049e70834cf33790a28643ab058b507b35cBen Cheng } 9925b3c049e70834cf33790a28643ab058b507b35cBen Cheng 10025b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (refshdr->sh_flags & SHF_ALLOC) 10125b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* Apply the adjustment. */ 10225b3c049e70834cf33790a28643ab058b507b35cBen Cheng *value += dwfl_adjusted_address (mod, refshdr->sh_addr); 10325b3c049e70834cf33790a28643ab058b507b35cBen Cheng 10425b3c049e70834cf33790a28643ab058b507b35cBen Cheng return DWFL_E_NOERROR; 10525b3c049e70834cf33790a28643ab058b507b35cBen Cheng} 10625b3c049e70834cf33790a28643ab058b507b35cBen Cheng 10725b3c049e70834cf33790a28643ab058b507b35cBen Cheng 10825b3c049e70834cf33790a28643ab058b507b35cBen Cheng/* Cache used by relocate_getsym. */ 10925b3c049e70834cf33790a28643ab058b507b35cBen Chengstruct reloc_symtab_cache 11025b3c049e70834cf33790a28643ab058b507b35cBen Cheng{ 11125b3c049e70834cf33790a28643ab058b507b35cBen Cheng Elf *symelf; 11225b3c049e70834cf33790a28643ab058b507b35cBen Cheng Elf_Data *symdata; 11325b3c049e70834cf33790a28643ab058b507b35cBen Cheng Elf_Data *symxndxdata; 11425b3c049e70834cf33790a28643ab058b507b35cBen Cheng Elf_Data *symstrdata; 11525b3c049e70834cf33790a28643ab058b507b35cBen Cheng size_t symshstrndx; 11625b3c049e70834cf33790a28643ab058b507b35cBen Cheng size_t strtabndx; 11725b3c049e70834cf33790a28643ab058b507b35cBen Cheng}; 11825b3c049e70834cf33790a28643ab058b507b35cBen Cheng#define RELOC_SYMTAB_CACHE(cache) \ 11925b3c049e70834cf33790a28643ab058b507b35cBen Cheng struct reloc_symtab_cache cache = \ 12025b3c049e70834cf33790a28643ab058b507b35cBen Cheng { NULL, NULL, NULL, NULL, SHN_UNDEF, SHN_UNDEF } 12125b3c049e70834cf33790a28643ab058b507b35cBen Cheng 12225b3c049e70834cf33790a28643ab058b507b35cBen Cheng/* This is just doing dwfl_module_getsym, except that we must always use 12325b3c049e70834cf33790a28643ab058b507b35cBen Cheng the symbol table in RELOCATED itself when it has one, not MOD->symfile. */ 12425b3c049e70834cf33790a28643ab058b507b35cBen Chengstatic Dwfl_Error 12525b3c049e70834cf33790a28643ab058b507b35cBen Chengrelocate_getsym (Dwfl_Module *mod, 12625b3c049e70834cf33790a28643ab058b507b35cBen Cheng Elf *relocated, struct reloc_symtab_cache *cache, 12725b3c049e70834cf33790a28643ab058b507b35cBen Cheng int symndx, GElf_Sym *sym, GElf_Word *shndx) 12825b3c049e70834cf33790a28643ab058b507b35cBen Cheng{ 12925b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (cache->symdata == NULL) 13025b3c049e70834cf33790a28643ab058b507b35cBen Cheng { 13125b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (mod->symfile == NULL || mod->symfile->elf != relocated) 13225b3c049e70834cf33790a28643ab058b507b35cBen Cheng { 13325b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* We have to look up the symbol table in the file we are 13425b3c049e70834cf33790a28643ab058b507b35cBen Cheng relocating, if it has its own. These reloc sections refer to 13525b3c049e70834cf33790a28643ab058b507b35cBen Cheng the symbol table in this file, and a symbol table in the main 13625b3c049e70834cf33790a28643ab058b507b35cBen Cheng file might not match. However, some tools did produce ET_REL 13725b3c049e70834cf33790a28643ab058b507b35cBen Cheng .debug files with relocs but no symtab of their own. */ 13825b3c049e70834cf33790a28643ab058b507b35cBen Cheng Elf_Scn *scn = NULL; 13925b3c049e70834cf33790a28643ab058b507b35cBen Cheng while ((scn = elf_nextscn (relocated, scn)) != NULL) 14025b3c049e70834cf33790a28643ab058b507b35cBen Cheng { 14125b3c049e70834cf33790a28643ab058b507b35cBen Cheng GElf_Shdr shdr_mem, *shdr = gelf_getshdr (scn, &shdr_mem); 14225b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (shdr != NULL) 14325b3c049e70834cf33790a28643ab058b507b35cBen Cheng switch (shdr->sh_type) 14425b3c049e70834cf33790a28643ab058b507b35cBen Cheng { 14525b3c049e70834cf33790a28643ab058b507b35cBen Cheng default: 14625b3c049e70834cf33790a28643ab058b507b35cBen Cheng continue; 14725b3c049e70834cf33790a28643ab058b507b35cBen Cheng case SHT_SYMTAB: 14825b3c049e70834cf33790a28643ab058b507b35cBen Cheng cache->symelf = relocated; 14925b3c049e70834cf33790a28643ab058b507b35cBen Cheng cache->symdata = elf_getdata (scn, NULL); 15025b3c049e70834cf33790a28643ab058b507b35cBen Cheng cache->strtabndx = shdr->sh_link; 15125b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (unlikely (cache->symdata == NULL)) 15225b3c049e70834cf33790a28643ab058b507b35cBen Cheng return DWFL_E_LIBELF; 15325b3c049e70834cf33790a28643ab058b507b35cBen Cheng break; 15425b3c049e70834cf33790a28643ab058b507b35cBen Cheng case SHT_SYMTAB_SHNDX: 15525b3c049e70834cf33790a28643ab058b507b35cBen Cheng cache->symxndxdata = elf_getdata (scn, NULL); 15625b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (unlikely (cache->symxndxdata == NULL)) 15725b3c049e70834cf33790a28643ab058b507b35cBen Cheng return DWFL_E_LIBELF; 15825b3c049e70834cf33790a28643ab058b507b35cBen Cheng break; 15925b3c049e70834cf33790a28643ab058b507b35cBen Cheng } 16025b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (cache->symdata != NULL && cache->symxndxdata != NULL) 16125b3c049e70834cf33790a28643ab058b507b35cBen Cheng break; 16225b3c049e70834cf33790a28643ab058b507b35cBen Cheng } 16325b3c049e70834cf33790a28643ab058b507b35cBen Cheng } 16425b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (cache->symdata == NULL) 16525b3c049e70834cf33790a28643ab058b507b35cBen Cheng { 16625b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* We might not have looked for a symbol table file yet, 16725b3c049e70834cf33790a28643ab058b507b35cBen Cheng when coming from __libdwfl_relocate_section. */ 16825b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (unlikely (mod->symfile == NULL) 16925b3c049e70834cf33790a28643ab058b507b35cBen Cheng && unlikely (INTUSE(dwfl_module_getsymtab) (mod) < 0)) 17025b3c049e70834cf33790a28643ab058b507b35cBen Cheng return dwfl_errno (); 17125b3c049e70834cf33790a28643ab058b507b35cBen Cheng 17225b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* The symbol table we have already cached is the one from 17325b3c049e70834cf33790a28643ab058b507b35cBen Cheng the file being relocated, so it's what we need. Or else 17425b3c049e70834cf33790a28643ab058b507b35cBen Cheng this is an ET_REL .debug file with no .symtab of its own; 17525b3c049e70834cf33790a28643ab058b507b35cBen Cheng the symbols refer to the section indices in the main file. */ 17625b3c049e70834cf33790a28643ab058b507b35cBen Cheng cache->symelf = mod->symfile->elf; 17725b3c049e70834cf33790a28643ab058b507b35cBen Cheng cache->symdata = mod->symdata; 17825b3c049e70834cf33790a28643ab058b507b35cBen Cheng cache->symxndxdata = mod->symxndxdata; 17925b3c049e70834cf33790a28643ab058b507b35cBen Cheng cache->symstrdata = mod->symstrdata; 18025b3c049e70834cf33790a28643ab058b507b35cBen Cheng } 18125b3c049e70834cf33790a28643ab058b507b35cBen Cheng } 18225b3c049e70834cf33790a28643ab058b507b35cBen Cheng 18325b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (unlikely (gelf_getsymshndx (cache->symdata, cache->symxndxdata, 18425b3c049e70834cf33790a28643ab058b507b35cBen Cheng symndx, sym, shndx) == NULL)) 18525b3c049e70834cf33790a28643ab058b507b35cBen Cheng return DWFL_E_LIBELF; 18625b3c049e70834cf33790a28643ab058b507b35cBen Cheng 18725b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (sym->st_shndx != SHN_XINDEX) 18825b3c049e70834cf33790a28643ab058b507b35cBen Cheng *shndx = sym->st_shndx; 18925b3c049e70834cf33790a28643ab058b507b35cBen Cheng 19025b3c049e70834cf33790a28643ab058b507b35cBen Cheng switch (sym->st_shndx) 19125b3c049e70834cf33790a28643ab058b507b35cBen Cheng { 19225b3c049e70834cf33790a28643ab058b507b35cBen Cheng case SHN_ABS: 19325b3c049e70834cf33790a28643ab058b507b35cBen Cheng case SHN_UNDEF: 19425b3c049e70834cf33790a28643ab058b507b35cBen Cheng return DWFL_E_NOERROR; 19525b3c049e70834cf33790a28643ab058b507b35cBen Cheng 19625b3c049e70834cf33790a28643ab058b507b35cBen Cheng case SHN_COMMON: 19725b3c049e70834cf33790a28643ab058b507b35cBen Cheng sym->st_value = 0; /* Value is size, not helpful. */ 19825b3c049e70834cf33790a28643ab058b507b35cBen Cheng return DWFL_E_NOERROR; 19925b3c049e70834cf33790a28643ab058b507b35cBen Cheng } 20025b3c049e70834cf33790a28643ab058b507b35cBen Cheng 20125b3c049e70834cf33790a28643ab058b507b35cBen Cheng return __libdwfl_relocate_value (mod, cache->symelf, &cache->symshstrndx, 20225b3c049e70834cf33790a28643ab058b507b35cBen Cheng *shndx, &sym->st_value); 20325b3c049e70834cf33790a28643ab058b507b35cBen Cheng} 20425b3c049e70834cf33790a28643ab058b507b35cBen Cheng 20525b3c049e70834cf33790a28643ab058b507b35cBen Cheng/* Handle an undefined symbol. We really only support ET_REL for Linux 20625b3c049e70834cf33790a28643ab058b507b35cBen Cheng kernel modules, and offline archives. The behavior of the Linux module 20725b3c049e70834cf33790a28643ab058b507b35cBen Cheng loader is very simple and easy to mimic. It only matches magically 20825b3c049e70834cf33790a28643ab058b507b35cBen Cheng exported symbols, and we match any defined symbols. But we get the same 20925b3c049e70834cf33790a28643ab058b507b35cBen Cheng answer except when the module's symbols are undefined and would prevent 21025b3c049e70834cf33790a28643ab058b507b35cBen Cheng it from being loaded. */ 21125b3c049e70834cf33790a28643ab058b507b35cBen Chengstatic Dwfl_Error 21225b3c049e70834cf33790a28643ab058b507b35cBen Chengresolve_symbol (Dwfl_Module *referer, struct reloc_symtab_cache *symtab, 21325b3c049e70834cf33790a28643ab058b507b35cBen Cheng GElf_Sym *sym, GElf_Word shndx) 21425b3c049e70834cf33790a28643ab058b507b35cBen Cheng{ 21525b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* First we need its name. */ 21625b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (sym->st_name != 0) 21725b3c049e70834cf33790a28643ab058b507b35cBen Cheng { 21825b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (symtab->symstrdata == NULL) 21925b3c049e70834cf33790a28643ab058b507b35cBen Cheng { 22025b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* Cache the strtab for this symtab. */ 22125b3c049e70834cf33790a28643ab058b507b35cBen Cheng assert (referer->symfile == NULL 22225b3c049e70834cf33790a28643ab058b507b35cBen Cheng || referer->symfile->elf != symtab->symelf); 22325b3c049e70834cf33790a28643ab058b507b35cBen Cheng symtab->symstrdata = elf_getdata (elf_getscn (symtab->symelf, 22425b3c049e70834cf33790a28643ab058b507b35cBen Cheng symtab->strtabndx), 22525b3c049e70834cf33790a28643ab058b507b35cBen Cheng NULL); 22625b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (unlikely (symtab->symstrdata == NULL)) 22725b3c049e70834cf33790a28643ab058b507b35cBen Cheng return DWFL_E_LIBELF; 22825b3c049e70834cf33790a28643ab058b507b35cBen Cheng } 22925b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (unlikely (sym->st_name >= symtab->symstrdata->d_size)) 23025b3c049e70834cf33790a28643ab058b507b35cBen Cheng return DWFL_E_BADSTROFF; 23125b3c049e70834cf33790a28643ab058b507b35cBen Cheng 23225b3c049e70834cf33790a28643ab058b507b35cBen Cheng const char *name = symtab->symstrdata->d_buf; 23325b3c049e70834cf33790a28643ab058b507b35cBen Cheng name += sym->st_name; 23425b3c049e70834cf33790a28643ab058b507b35cBen Cheng 23525b3c049e70834cf33790a28643ab058b507b35cBen Cheng for (Dwfl_Module *m = referer->dwfl->modulelist; m != NULL; m = m->next) 23625b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (m != referer) 23725b3c049e70834cf33790a28643ab058b507b35cBen Cheng { 23825b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* Get this module's symtab. 23925b3c049e70834cf33790a28643ab058b507b35cBen Cheng If we got a fresh error reading the table, report it. 24025b3c049e70834cf33790a28643ab058b507b35cBen Cheng If we just have no symbols in this module, no harm done. */ 24125b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (m->symdata == NULL 24225b3c049e70834cf33790a28643ab058b507b35cBen Cheng && m->symerr == DWFL_E_NOERROR 24325b3c049e70834cf33790a28643ab058b507b35cBen Cheng && INTUSE(dwfl_module_getsymtab) (m) < 0 24425b3c049e70834cf33790a28643ab058b507b35cBen Cheng && m->symerr != DWFL_E_NO_SYMTAB) 24525b3c049e70834cf33790a28643ab058b507b35cBen Cheng return m->symerr; 24625b3c049e70834cf33790a28643ab058b507b35cBen Cheng 24725b3c049e70834cf33790a28643ab058b507b35cBen Cheng for (size_t ndx = 1; ndx < m->syments; ++ndx) 24825b3c049e70834cf33790a28643ab058b507b35cBen Cheng { 24925b3c049e70834cf33790a28643ab058b507b35cBen Cheng sym = gelf_getsymshndx (m->symdata, m->symxndxdata, 25025b3c049e70834cf33790a28643ab058b507b35cBen Cheng ndx, sym, &shndx); 25125b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (unlikely (sym == NULL)) 25225b3c049e70834cf33790a28643ab058b507b35cBen Cheng return DWFL_E_LIBELF; 25325b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (sym->st_shndx != SHN_XINDEX) 25425b3c049e70834cf33790a28643ab058b507b35cBen Cheng shndx = sym->st_shndx; 25525b3c049e70834cf33790a28643ab058b507b35cBen Cheng 25625b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* We are looking for a defined global symbol with a name. */ 25725b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (shndx == SHN_UNDEF || shndx == SHN_COMMON 25825b3c049e70834cf33790a28643ab058b507b35cBen Cheng || GELF_ST_BIND (sym->st_info) == STB_LOCAL 25925b3c049e70834cf33790a28643ab058b507b35cBen Cheng || sym->st_name == 0) 26025b3c049e70834cf33790a28643ab058b507b35cBen Cheng continue; 26125b3c049e70834cf33790a28643ab058b507b35cBen Cheng 26225b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* Get this candidate symbol's name. */ 26325b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (unlikely (sym->st_name >= m->symstrdata->d_size)) 26425b3c049e70834cf33790a28643ab058b507b35cBen Cheng return DWFL_E_BADSTROFF; 26525b3c049e70834cf33790a28643ab058b507b35cBen Cheng const char *n = m->symstrdata->d_buf; 26625b3c049e70834cf33790a28643ab058b507b35cBen Cheng n += sym->st_name; 26725b3c049e70834cf33790a28643ab058b507b35cBen Cheng 26825b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* Does the name match? */ 26925b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (strcmp (name, n)) 27025b3c049e70834cf33790a28643ab058b507b35cBen Cheng continue; 27125b3c049e70834cf33790a28643ab058b507b35cBen Cheng 27225b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* We found it! */ 27325b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (shndx == SHN_ABS) /* XXX maybe should apply bias? */ 27425b3c049e70834cf33790a28643ab058b507b35cBen Cheng return DWFL_E_NOERROR; 27525b3c049e70834cf33790a28643ab058b507b35cBen Cheng 27625b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (m->e_type != ET_REL) 27725b3c049e70834cf33790a28643ab058b507b35cBen Cheng { 27825b3c049e70834cf33790a28643ab058b507b35cBen Cheng sym->st_value = dwfl_adjusted_st_value (m, sym->st_value); 27925b3c049e70834cf33790a28643ab058b507b35cBen Cheng return DWFL_E_NOERROR; 28025b3c049e70834cf33790a28643ab058b507b35cBen Cheng } 28125b3c049e70834cf33790a28643ab058b507b35cBen Cheng 28225b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* In an ET_REL file, the symbol table values are relative 28325b3c049e70834cf33790a28643ab058b507b35cBen Cheng to the section, not to the module's load base. */ 28425b3c049e70834cf33790a28643ab058b507b35cBen Cheng size_t symshstrndx = SHN_UNDEF; 28525b3c049e70834cf33790a28643ab058b507b35cBen Cheng return __libdwfl_relocate_value (m, m->symfile->elf, 28625b3c049e70834cf33790a28643ab058b507b35cBen Cheng &symshstrndx, 28725b3c049e70834cf33790a28643ab058b507b35cBen Cheng shndx, &sym->st_value); 28825b3c049e70834cf33790a28643ab058b507b35cBen Cheng } 28925b3c049e70834cf33790a28643ab058b507b35cBen Cheng } 29025b3c049e70834cf33790a28643ab058b507b35cBen Cheng } 29125b3c049e70834cf33790a28643ab058b507b35cBen Cheng 29225b3c049e70834cf33790a28643ab058b507b35cBen Cheng return DWFL_E_RELUNDEF; 29325b3c049e70834cf33790a28643ab058b507b35cBen Cheng} 29425b3c049e70834cf33790a28643ab058b507b35cBen Cheng 29525b3c049e70834cf33790a28643ab058b507b35cBen Chengstatic Dwfl_Error 29625b3c049e70834cf33790a28643ab058b507b35cBen Chengrelocate_section (Dwfl_Module *mod, Elf *relocated, const GElf_Ehdr *ehdr, 29725b3c049e70834cf33790a28643ab058b507b35cBen Cheng size_t shstrndx, struct reloc_symtab_cache *reloc_symtab, 29825b3c049e70834cf33790a28643ab058b507b35cBen Cheng Elf_Scn *scn, GElf_Shdr *shdr, 29925b3c049e70834cf33790a28643ab058b507b35cBen Cheng Elf_Scn *tscn, bool debugscn, bool partial) 30025b3c049e70834cf33790a28643ab058b507b35cBen Cheng{ 30125b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* First, fetch the name of the section these relocations apply to. */ 30225b3c049e70834cf33790a28643ab058b507b35cBen Cheng GElf_Shdr tshdr_mem; 30325b3c049e70834cf33790a28643ab058b507b35cBen Cheng GElf_Shdr *tshdr = gelf_getshdr (tscn, &tshdr_mem); 30425b3c049e70834cf33790a28643ab058b507b35cBen Cheng const char *tname = elf_strptr (relocated, shstrndx, tshdr->sh_name); 30525b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (tname == NULL) 30625b3c049e70834cf33790a28643ab058b507b35cBen Cheng return DWFL_E_LIBELF; 30725b3c049e70834cf33790a28643ab058b507b35cBen Cheng 30825b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (unlikely (tshdr->sh_type == SHT_NOBITS) || unlikely (tshdr->sh_size == 0)) 30925b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* No contents to relocate. */ 31025b3c049e70834cf33790a28643ab058b507b35cBen Cheng return DWFL_E_NOERROR; 31125b3c049e70834cf33790a28643ab058b507b35cBen Cheng 31225b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (debugscn && ! ebl_debugscn_p (mod->ebl, tname)) 31325b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* This relocation section is not for a debugging section. 31425b3c049e70834cf33790a28643ab058b507b35cBen Cheng Nothing to do here. */ 31525b3c049e70834cf33790a28643ab058b507b35cBen Cheng return DWFL_E_NOERROR; 31625b3c049e70834cf33790a28643ab058b507b35cBen Cheng 31725b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* Fetch the section data that needs the relocations applied. */ 31825b3c049e70834cf33790a28643ab058b507b35cBen Cheng Elf_Data *tdata = elf_rawdata (tscn, NULL); 31925b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (tdata == NULL) 32025b3c049e70834cf33790a28643ab058b507b35cBen Cheng return DWFL_E_LIBELF; 32125b3c049e70834cf33790a28643ab058b507b35cBen Cheng 32225b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* Apply one relocation. Returns true for any invalid data. */ 32325b3c049e70834cf33790a28643ab058b507b35cBen Cheng Dwfl_Error relocate (GElf_Addr offset, const GElf_Sxword *addend, 32425b3c049e70834cf33790a28643ab058b507b35cBen Cheng int rtype, int symndx) 32525b3c049e70834cf33790a28643ab058b507b35cBen Cheng { 32625b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* First see if this is a reloc we can handle. 32725b3c049e70834cf33790a28643ab058b507b35cBen Cheng If we are skipping it, don't bother resolving the symbol. */ 32825b3c049e70834cf33790a28643ab058b507b35cBen Cheng 32925b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (unlikely (rtype == 0)) 33025b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* In some odd situations, the linker can leave R_*_NONE relocs 33125b3c049e70834cf33790a28643ab058b507b35cBen Cheng behind. This is probably bogus ld -r behavior, but the only 33225b3c049e70834cf33790a28643ab058b507b35cBen Cheng cases it's known to appear in are harmless: DWARF data 33325b3c049e70834cf33790a28643ab058b507b35cBen Cheng referring to addresses in a section that has been discarded. 33425b3c049e70834cf33790a28643ab058b507b35cBen Cheng So we just pretend it's OK without further relocation. */ 33525b3c049e70834cf33790a28643ab058b507b35cBen Cheng return DWFL_E_NOERROR; 33625b3c049e70834cf33790a28643ab058b507b35cBen Cheng 33725b3c049e70834cf33790a28643ab058b507b35cBen Cheng Elf_Type type = ebl_reloc_simple_type (mod->ebl, rtype); 33825b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (unlikely (type == ELF_T_NUM)) 33925b3c049e70834cf33790a28643ab058b507b35cBen Cheng return DWFL_E_BADRELTYPE; 34025b3c049e70834cf33790a28643ab058b507b35cBen Cheng 34125b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* First, resolve the symbol to an absolute value. */ 34225b3c049e70834cf33790a28643ab058b507b35cBen Cheng GElf_Addr value; 34325b3c049e70834cf33790a28643ab058b507b35cBen Cheng 34425b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (symndx == STN_UNDEF) 34525b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* When strip removes a section symbol referring to a 34625b3c049e70834cf33790a28643ab058b507b35cBen Cheng section moved into the debuginfo file, it replaces 34725b3c049e70834cf33790a28643ab058b507b35cBen Cheng that symbol index in relocs with STN_UNDEF. We 34825b3c049e70834cf33790a28643ab058b507b35cBen Cheng don't actually need the symbol, because those relocs 34925b3c049e70834cf33790a28643ab058b507b35cBen Cheng are always references relative to the nonallocated 35025b3c049e70834cf33790a28643ab058b507b35cBen Cheng debugging sections, which start at zero. */ 35125b3c049e70834cf33790a28643ab058b507b35cBen Cheng value = 0; 35225b3c049e70834cf33790a28643ab058b507b35cBen Cheng else 35325b3c049e70834cf33790a28643ab058b507b35cBen Cheng { 35425b3c049e70834cf33790a28643ab058b507b35cBen Cheng GElf_Sym sym; 35525b3c049e70834cf33790a28643ab058b507b35cBen Cheng GElf_Word shndx; 35625b3c049e70834cf33790a28643ab058b507b35cBen Cheng Dwfl_Error error = relocate_getsym (mod, relocated, reloc_symtab, 35725b3c049e70834cf33790a28643ab058b507b35cBen Cheng symndx, &sym, &shndx); 35825b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (unlikely (error != DWFL_E_NOERROR)) 35925b3c049e70834cf33790a28643ab058b507b35cBen Cheng return error; 36025b3c049e70834cf33790a28643ab058b507b35cBen Cheng 36125b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (shndx == SHN_UNDEF || shndx == SHN_COMMON) 36225b3c049e70834cf33790a28643ab058b507b35cBen Cheng { 36325b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* Maybe we can figure it out anyway. */ 36425b3c049e70834cf33790a28643ab058b507b35cBen Cheng error = resolve_symbol (mod, reloc_symtab, &sym, shndx); 36525b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (error != DWFL_E_NOERROR 36625b3c049e70834cf33790a28643ab058b507b35cBen Cheng && !(error == DWFL_E_RELUNDEF && shndx == SHN_COMMON)) 36725b3c049e70834cf33790a28643ab058b507b35cBen Cheng return error; 36825b3c049e70834cf33790a28643ab058b507b35cBen Cheng } 36925b3c049e70834cf33790a28643ab058b507b35cBen Cheng 37025b3c049e70834cf33790a28643ab058b507b35cBen Cheng value = sym.st_value; 37125b3c049e70834cf33790a28643ab058b507b35cBen Cheng } 37225b3c049e70834cf33790a28643ab058b507b35cBen Cheng 37325b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* These are the types we can relocate. */ 37425b3c049e70834cf33790a28643ab058b507b35cBen Cheng#define TYPES DO_TYPE (BYTE, Byte); DO_TYPE (HALF, Half); \ 37525b3c049e70834cf33790a28643ab058b507b35cBen Cheng DO_TYPE (WORD, Word); DO_TYPE (SWORD, Sword); \ 37625b3c049e70834cf33790a28643ab058b507b35cBen Cheng DO_TYPE (XWORD, Xword); DO_TYPE (SXWORD, Sxword) 37725b3c049e70834cf33790a28643ab058b507b35cBen Cheng size_t size; 37825b3c049e70834cf33790a28643ab058b507b35cBen Cheng switch (type) 37925b3c049e70834cf33790a28643ab058b507b35cBen Cheng { 38025b3c049e70834cf33790a28643ab058b507b35cBen Cheng#define DO_TYPE(NAME, Name) \ 38125b3c049e70834cf33790a28643ab058b507b35cBen Cheng case ELF_T_##NAME: \ 38225b3c049e70834cf33790a28643ab058b507b35cBen Cheng size = sizeof (GElf_##Name); \ 38325b3c049e70834cf33790a28643ab058b507b35cBen Cheng break 38425b3c049e70834cf33790a28643ab058b507b35cBen Cheng TYPES; 38525b3c049e70834cf33790a28643ab058b507b35cBen Cheng#undef DO_TYPE 38625b3c049e70834cf33790a28643ab058b507b35cBen Cheng default: 38725b3c049e70834cf33790a28643ab058b507b35cBen Cheng return DWFL_E_BADRELTYPE; 38825b3c049e70834cf33790a28643ab058b507b35cBen Cheng } 38925b3c049e70834cf33790a28643ab058b507b35cBen Cheng 39025b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (offset + size > tdata->d_size) 39125b3c049e70834cf33790a28643ab058b507b35cBen Cheng return DWFL_E_BADRELOFF; 39225b3c049e70834cf33790a28643ab058b507b35cBen Cheng 39325b3c049e70834cf33790a28643ab058b507b35cBen Cheng#define DO_TYPE(NAME, Name) GElf_##Name Name; 39425b3c049e70834cf33790a28643ab058b507b35cBen Cheng union { TYPES; } tmpbuf; 39525b3c049e70834cf33790a28643ab058b507b35cBen Cheng#undef DO_TYPE 39625b3c049e70834cf33790a28643ab058b507b35cBen Cheng Elf_Data tmpdata = 39725b3c049e70834cf33790a28643ab058b507b35cBen Cheng { 39825b3c049e70834cf33790a28643ab058b507b35cBen Cheng .d_type = type, 39925b3c049e70834cf33790a28643ab058b507b35cBen Cheng .d_buf = &tmpbuf, 40025b3c049e70834cf33790a28643ab058b507b35cBen Cheng .d_size = size, 40125b3c049e70834cf33790a28643ab058b507b35cBen Cheng .d_version = EV_CURRENT, 40225b3c049e70834cf33790a28643ab058b507b35cBen Cheng }; 40325b3c049e70834cf33790a28643ab058b507b35cBen Cheng Elf_Data rdata = 40425b3c049e70834cf33790a28643ab058b507b35cBen Cheng { 40525b3c049e70834cf33790a28643ab058b507b35cBen Cheng .d_type = type, 40625b3c049e70834cf33790a28643ab058b507b35cBen Cheng .d_buf = tdata->d_buf + offset, 40725b3c049e70834cf33790a28643ab058b507b35cBen Cheng .d_size = size, 40825b3c049e70834cf33790a28643ab058b507b35cBen Cheng .d_version = EV_CURRENT, 40925b3c049e70834cf33790a28643ab058b507b35cBen Cheng }; 41025b3c049e70834cf33790a28643ab058b507b35cBen Cheng 41125b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* XXX check for overflow? */ 41225b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (addend) 41325b3c049e70834cf33790a28643ab058b507b35cBen Cheng { 41425b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* For the addend form, we have the value already. */ 41525b3c049e70834cf33790a28643ab058b507b35cBen Cheng value += *addend; 41625b3c049e70834cf33790a28643ab058b507b35cBen Cheng switch (type) 41725b3c049e70834cf33790a28643ab058b507b35cBen Cheng { 41825b3c049e70834cf33790a28643ab058b507b35cBen Cheng#define DO_TYPE(NAME, Name) \ 41925b3c049e70834cf33790a28643ab058b507b35cBen Cheng case ELF_T_##NAME: \ 42025b3c049e70834cf33790a28643ab058b507b35cBen Cheng tmpbuf.Name = value; \ 42125b3c049e70834cf33790a28643ab058b507b35cBen Cheng break 42225b3c049e70834cf33790a28643ab058b507b35cBen Cheng TYPES; 42325b3c049e70834cf33790a28643ab058b507b35cBen Cheng#undef DO_TYPE 42425b3c049e70834cf33790a28643ab058b507b35cBen Cheng default: 42525b3c049e70834cf33790a28643ab058b507b35cBen Cheng abort (); 42625b3c049e70834cf33790a28643ab058b507b35cBen Cheng } 42725b3c049e70834cf33790a28643ab058b507b35cBen Cheng } 42825b3c049e70834cf33790a28643ab058b507b35cBen Cheng else 42925b3c049e70834cf33790a28643ab058b507b35cBen Cheng { 43025b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* Extract the original value and apply the reloc. */ 43125b3c049e70834cf33790a28643ab058b507b35cBen Cheng Elf_Data *d = gelf_xlatetom (relocated, &tmpdata, &rdata, 43225b3c049e70834cf33790a28643ab058b507b35cBen Cheng ehdr->e_ident[EI_DATA]); 43325b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (d == NULL) 43425b3c049e70834cf33790a28643ab058b507b35cBen Cheng return DWFL_E_LIBELF; 43525b3c049e70834cf33790a28643ab058b507b35cBen Cheng assert (d == &tmpdata); 43625b3c049e70834cf33790a28643ab058b507b35cBen Cheng switch (type) 43725b3c049e70834cf33790a28643ab058b507b35cBen Cheng { 43825b3c049e70834cf33790a28643ab058b507b35cBen Cheng#define DO_TYPE(NAME, Name) \ 43925b3c049e70834cf33790a28643ab058b507b35cBen Cheng case ELF_T_##NAME: \ 44025b3c049e70834cf33790a28643ab058b507b35cBen Cheng tmpbuf.Name += (GElf_##Name) value; \ 44125b3c049e70834cf33790a28643ab058b507b35cBen Cheng break 44225b3c049e70834cf33790a28643ab058b507b35cBen Cheng TYPES; 44325b3c049e70834cf33790a28643ab058b507b35cBen Cheng#undef DO_TYPE 44425b3c049e70834cf33790a28643ab058b507b35cBen Cheng default: 44525b3c049e70834cf33790a28643ab058b507b35cBen Cheng abort (); 44625b3c049e70834cf33790a28643ab058b507b35cBen Cheng } 44725b3c049e70834cf33790a28643ab058b507b35cBen Cheng } 44825b3c049e70834cf33790a28643ab058b507b35cBen Cheng 44925b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* Now convert the relocated datum back to the target 45025b3c049e70834cf33790a28643ab058b507b35cBen Cheng format. This will write into rdata.d_buf, which 45125b3c049e70834cf33790a28643ab058b507b35cBen Cheng points into the raw section data being relocated. */ 45225b3c049e70834cf33790a28643ab058b507b35cBen Cheng Elf_Data *s = gelf_xlatetof (relocated, &rdata, &tmpdata, 45325b3c049e70834cf33790a28643ab058b507b35cBen Cheng ehdr->e_ident[EI_DATA]); 45425b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (s == NULL) 45525b3c049e70834cf33790a28643ab058b507b35cBen Cheng return DWFL_E_LIBELF; 45625b3c049e70834cf33790a28643ab058b507b35cBen Cheng assert (s == &rdata); 45725b3c049e70834cf33790a28643ab058b507b35cBen Cheng 45825b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* We have applied this relocation! */ 45925b3c049e70834cf33790a28643ab058b507b35cBen Cheng return DWFL_E_NOERROR; 46025b3c049e70834cf33790a28643ab058b507b35cBen Cheng } 46125b3c049e70834cf33790a28643ab058b507b35cBen Cheng 46225b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* Fetch the relocation section and apply each reloc in it. */ 46325b3c049e70834cf33790a28643ab058b507b35cBen Cheng Elf_Data *reldata = elf_getdata (scn, NULL); 46425b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (reldata == NULL) 46525b3c049e70834cf33790a28643ab058b507b35cBen Cheng return DWFL_E_LIBELF; 46625b3c049e70834cf33790a28643ab058b507b35cBen Cheng 46725b3c049e70834cf33790a28643ab058b507b35cBen Cheng Dwfl_Error result = DWFL_E_NOERROR; 46825b3c049e70834cf33790a28643ab058b507b35cBen Cheng bool first_badreltype = true; 46925b3c049e70834cf33790a28643ab058b507b35cBen Cheng inline void check_badreltype (void) 47025b3c049e70834cf33790a28643ab058b507b35cBen Cheng { 47125b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (first_badreltype) 47225b3c049e70834cf33790a28643ab058b507b35cBen Cheng { 47325b3c049e70834cf33790a28643ab058b507b35cBen Cheng first_badreltype = false; 47425b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (ebl_get_elfmachine (mod->ebl) == EM_NONE) 47525b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* This might be because ebl_openbackend failed to find 47625b3c049e70834cf33790a28643ab058b507b35cBen Cheng any libebl_CPU.so library. Diagnose that clearly. */ 47725b3c049e70834cf33790a28643ab058b507b35cBen Cheng result = DWFL_E_UNKNOWN_MACHINE; 47825b3c049e70834cf33790a28643ab058b507b35cBen Cheng } 47925b3c049e70834cf33790a28643ab058b507b35cBen Cheng } 48025b3c049e70834cf33790a28643ab058b507b35cBen Cheng 48125b3c049e70834cf33790a28643ab058b507b35cBen Cheng size_t nrels = shdr->sh_size / shdr->sh_entsize; 48225b3c049e70834cf33790a28643ab058b507b35cBen Cheng size_t complete = 0; 48325b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (shdr->sh_type == SHT_REL) 48425b3c049e70834cf33790a28643ab058b507b35cBen Cheng for (size_t relidx = 0; !result && relidx < nrels; ++relidx) 48525b3c049e70834cf33790a28643ab058b507b35cBen Cheng { 48625b3c049e70834cf33790a28643ab058b507b35cBen Cheng GElf_Rel rel_mem, *r = gelf_getrel (reldata, relidx, &rel_mem); 48725b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (r == NULL) 48825b3c049e70834cf33790a28643ab058b507b35cBen Cheng return DWFL_E_LIBELF; 48925b3c049e70834cf33790a28643ab058b507b35cBen Cheng result = relocate (r->r_offset, NULL, 49025b3c049e70834cf33790a28643ab058b507b35cBen Cheng GELF_R_TYPE (r->r_info), 49125b3c049e70834cf33790a28643ab058b507b35cBen Cheng GELF_R_SYM (r->r_info)); 49225b3c049e70834cf33790a28643ab058b507b35cBen Cheng check_badreltype (); 49325b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (partial) 49425b3c049e70834cf33790a28643ab058b507b35cBen Cheng switch (result) 49525b3c049e70834cf33790a28643ab058b507b35cBen Cheng { 49625b3c049e70834cf33790a28643ab058b507b35cBen Cheng case DWFL_E_NOERROR: 49725b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* We applied the relocation. Elide it. */ 49825b3c049e70834cf33790a28643ab058b507b35cBen Cheng memset (&rel_mem, 0, sizeof rel_mem); 49925b3c049e70834cf33790a28643ab058b507b35cBen Cheng gelf_update_rel (reldata, relidx, &rel_mem); 50025b3c049e70834cf33790a28643ab058b507b35cBen Cheng ++complete; 50125b3c049e70834cf33790a28643ab058b507b35cBen Cheng break; 50225b3c049e70834cf33790a28643ab058b507b35cBen Cheng case DWFL_E_BADRELTYPE: 50325b3c049e70834cf33790a28643ab058b507b35cBen Cheng case DWFL_E_RELUNDEF: 50425b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* We couldn't handle this relocation. Skip it. */ 50525b3c049e70834cf33790a28643ab058b507b35cBen Cheng result = DWFL_E_NOERROR; 50625b3c049e70834cf33790a28643ab058b507b35cBen Cheng break; 50725b3c049e70834cf33790a28643ab058b507b35cBen Cheng default: 50825b3c049e70834cf33790a28643ab058b507b35cBen Cheng break; 50925b3c049e70834cf33790a28643ab058b507b35cBen Cheng } 51025b3c049e70834cf33790a28643ab058b507b35cBen Cheng } 51125b3c049e70834cf33790a28643ab058b507b35cBen Cheng else 51225b3c049e70834cf33790a28643ab058b507b35cBen Cheng for (size_t relidx = 0; !result && relidx < nrels; ++relidx) 51325b3c049e70834cf33790a28643ab058b507b35cBen Cheng { 51425b3c049e70834cf33790a28643ab058b507b35cBen Cheng GElf_Rela rela_mem, *r = gelf_getrela (reldata, relidx, 51525b3c049e70834cf33790a28643ab058b507b35cBen Cheng &rela_mem); 51625b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (r == NULL) 51725b3c049e70834cf33790a28643ab058b507b35cBen Cheng return DWFL_E_LIBELF; 51825b3c049e70834cf33790a28643ab058b507b35cBen Cheng result = relocate (r->r_offset, &r->r_addend, 51925b3c049e70834cf33790a28643ab058b507b35cBen Cheng GELF_R_TYPE (r->r_info), 52025b3c049e70834cf33790a28643ab058b507b35cBen Cheng GELF_R_SYM (r->r_info)); 52125b3c049e70834cf33790a28643ab058b507b35cBen Cheng check_badreltype (); 52225b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (partial) 52325b3c049e70834cf33790a28643ab058b507b35cBen Cheng switch (result) 52425b3c049e70834cf33790a28643ab058b507b35cBen Cheng { 52525b3c049e70834cf33790a28643ab058b507b35cBen Cheng case DWFL_E_NOERROR: 52625b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* We applied the relocation. Elide it. */ 52725b3c049e70834cf33790a28643ab058b507b35cBen Cheng memset (&rela_mem, 0, sizeof rela_mem); 52825b3c049e70834cf33790a28643ab058b507b35cBen Cheng gelf_update_rela (reldata, relidx, &rela_mem); 52925b3c049e70834cf33790a28643ab058b507b35cBen Cheng ++complete; 53025b3c049e70834cf33790a28643ab058b507b35cBen Cheng break; 53125b3c049e70834cf33790a28643ab058b507b35cBen Cheng case DWFL_E_BADRELTYPE: 53225b3c049e70834cf33790a28643ab058b507b35cBen Cheng case DWFL_E_RELUNDEF: 53325b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* We couldn't handle this relocation. Skip it. */ 53425b3c049e70834cf33790a28643ab058b507b35cBen Cheng result = DWFL_E_NOERROR; 53525b3c049e70834cf33790a28643ab058b507b35cBen Cheng break; 53625b3c049e70834cf33790a28643ab058b507b35cBen Cheng default: 53725b3c049e70834cf33790a28643ab058b507b35cBen Cheng break; 53825b3c049e70834cf33790a28643ab058b507b35cBen Cheng } 53925b3c049e70834cf33790a28643ab058b507b35cBen Cheng } 54025b3c049e70834cf33790a28643ab058b507b35cBen Cheng 54125b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (likely (result == DWFL_E_NOERROR)) 54225b3c049e70834cf33790a28643ab058b507b35cBen Cheng { 54325b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (!partial || complete == nrels) 54425b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* Mark this relocation section as being empty now that we have 54525b3c049e70834cf33790a28643ab058b507b35cBen Cheng done its work. This affects unstrip -R, so e.g. it emits an 54625b3c049e70834cf33790a28643ab058b507b35cBen Cheng empty .rela.debug_info along with a .debug_info that has 54725b3c049e70834cf33790a28643ab058b507b35cBen Cheng already been fully relocated. */ 54825b3c049e70834cf33790a28643ab058b507b35cBen Cheng nrels = 0; 54925b3c049e70834cf33790a28643ab058b507b35cBen Cheng else if (complete != 0) 55025b3c049e70834cf33790a28643ab058b507b35cBen Cheng { 55125b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* We handled some of the relocations but not all. 55225b3c049e70834cf33790a28643ab058b507b35cBen Cheng We've zeroed out the ones we processed. 55325b3c049e70834cf33790a28643ab058b507b35cBen Cheng Now remove them from the section. */ 55425b3c049e70834cf33790a28643ab058b507b35cBen Cheng 55525b3c049e70834cf33790a28643ab058b507b35cBen Cheng size_t next = 0; 55625b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (shdr->sh_type == SHT_REL) 55725b3c049e70834cf33790a28643ab058b507b35cBen Cheng for (size_t relidx = 0; relidx < nrels; ++relidx) 55825b3c049e70834cf33790a28643ab058b507b35cBen Cheng { 55925b3c049e70834cf33790a28643ab058b507b35cBen Cheng GElf_Rel rel_mem; 56025b3c049e70834cf33790a28643ab058b507b35cBen Cheng GElf_Rel *r = gelf_getrel (reldata, relidx, &rel_mem); 56125b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (r->r_info != 0 || r->r_offset != 0) 56225b3c049e70834cf33790a28643ab058b507b35cBen Cheng { 56325b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (next != relidx) 56425b3c049e70834cf33790a28643ab058b507b35cBen Cheng gelf_update_rel (reldata, next, r); 56525b3c049e70834cf33790a28643ab058b507b35cBen Cheng ++next; 56625b3c049e70834cf33790a28643ab058b507b35cBen Cheng } 56725b3c049e70834cf33790a28643ab058b507b35cBen Cheng } 56825b3c049e70834cf33790a28643ab058b507b35cBen Cheng else 56925b3c049e70834cf33790a28643ab058b507b35cBen Cheng for (size_t relidx = 0; relidx < nrels; ++relidx) 57025b3c049e70834cf33790a28643ab058b507b35cBen Cheng { 57125b3c049e70834cf33790a28643ab058b507b35cBen Cheng GElf_Rela rela_mem; 57225b3c049e70834cf33790a28643ab058b507b35cBen Cheng GElf_Rela *r = gelf_getrela (reldata, relidx, &rela_mem); 57325b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (r->r_info != 0 || r->r_offset != 0 || r->r_addend != 0) 57425b3c049e70834cf33790a28643ab058b507b35cBen Cheng { 57525b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (next != relidx) 57625b3c049e70834cf33790a28643ab058b507b35cBen Cheng gelf_update_rela (reldata, next, r); 57725b3c049e70834cf33790a28643ab058b507b35cBen Cheng ++next; 57825b3c049e70834cf33790a28643ab058b507b35cBen Cheng } 57925b3c049e70834cf33790a28643ab058b507b35cBen Cheng } 58025b3c049e70834cf33790a28643ab058b507b35cBen Cheng nrels = next; 58125b3c049e70834cf33790a28643ab058b507b35cBen Cheng } 58225b3c049e70834cf33790a28643ab058b507b35cBen Cheng 58325b3c049e70834cf33790a28643ab058b507b35cBen Cheng shdr->sh_size = reldata->d_size = nrels * shdr->sh_entsize; 58425b3c049e70834cf33790a28643ab058b507b35cBen Cheng gelf_update_shdr (scn, shdr); 58525b3c049e70834cf33790a28643ab058b507b35cBen Cheng } 58625b3c049e70834cf33790a28643ab058b507b35cBen Cheng 58725b3c049e70834cf33790a28643ab058b507b35cBen Cheng return result; 58825b3c049e70834cf33790a28643ab058b507b35cBen Cheng} 58925b3c049e70834cf33790a28643ab058b507b35cBen Cheng 59025b3c049e70834cf33790a28643ab058b507b35cBen ChengDwfl_Error 59125b3c049e70834cf33790a28643ab058b507b35cBen Chenginternal_function 59225b3c049e70834cf33790a28643ab058b507b35cBen Cheng__libdwfl_relocate (Dwfl_Module *mod, Elf *debugfile, bool debug) 59325b3c049e70834cf33790a28643ab058b507b35cBen Cheng{ 59425b3c049e70834cf33790a28643ab058b507b35cBen Cheng assert (mod->e_type == ET_REL); 59525b3c049e70834cf33790a28643ab058b507b35cBen Cheng 59625b3c049e70834cf33790a28643ab058b507b35cBen Cheng GElf_Ehdr ehdr_mem; 59725b3c049e70834cf33790a28643ab058b507b35cBen Cheng const GElf_Ehdr *ehdr = gelf_getehdr (debugfile, &ehdr_mem); 59825b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (ehdr == NULL) 59925b3c049e70834cf33790a28643ab058b507b35cBen Cheng return DWFL_E_LIBELF; 60025b3c049e70834cf33790a28643ab058b507b35cBen Cheng 60125b3c049e70834cf33790a28643ab058b507b35cBen Cheng size_t d_shstrndx; 60225b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (elf_getshdrstrndx (debugfile, &d_shstrndx) < 0) 60325b3c049e70834cf33790a28643ab058b507b35cBen Cheng return DWFL_E_LIBELF; 60425b3c049e70834cf33790a28643ab058b507b35cBen Cheng 60525b3c049e70834cf33790a28643ab058b507b35cBen Cheng RELOC_SYMTAB_CACHE (reloc_symtab); 60625b3c049e70834cf33790a28643ab058b507b35cBen Cheng 60725b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* Look at each section in the debuginfo file, and process the 60825b3c049e70834cf33790a28643ab058b507b35cBen Cheng relocation sections for debugging sections. */ 60925b3c049e70834cf33790a28643ab058b507b35cBen Cheng Dwfl_Error result = DWFL_E_NOERROR; 61025b3c049e70834cf33790a28643ab058b507b35cBen Cheng Elf_Scn *scn = NULL; 61125b3c049e70834cf33790a28643ab058b507b35cBen Cheng while (result == DWFL_E_NOERROR 61225b3c049e70834cf33790a28643ab058b507b35cBen Cheng && (scn = elf_nextscn (debugfile, scn)) != NULL) 61325b3c049e70834cf33790a28643ab058b507b35cBen Cheng { 61425b3c049e70834cf33790a28643ab058b507b35cBen Cheng GElf_Shdr shdr_mem; 61525b3c049e70834cf33790a28643ab058b507b35cBen Cheng GElf_Shdr *shdr = gelf_getshdr (scn, &shdr_mem); 61625b3c049e70834cf33790a28643ab058b507b35cBen Cheng 61725b3c049e70834cf33790a28643ab058b507b35cBen Cheng if ((shdr->sh_type == SHT_REL || shdr->sh_type == SHT_RELA) 61825b3c049e70834cf33790a28643ab058b507b35cBen Cheng && shdr->sh_size != 0) 61925b3c049e70834cf33790a28643ab058b507b35cBen Cheng { 62025b3c049e70834cf33790a28643ab058b507b35cBen Cheng /* It's a relocation section. */ 62125b3c049e70834cf33790a28643ab058b507b35cBen Cheng 62225b3c049e70834cf33790a28643ab058b507b35cBen Cheng Elf_Scn *tscn = elf_getscn (debugfile, shdr->sh_info); 62325b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (unlikely (tscn == NULL)) 62425b3c049e70834cf33790a28643ab058b507b35cBen Cheng result = DWFL_E_LIBELF; 62525b3c049e70834cf33790a28643ab058b507b35cBen Cheng else 62625b3c049e70834cf33790a28643ab058b507b35cBen Cheng result = relocate_section (mod, debugfile, ehdr, d_shstrndx, 62725b3c049e70834cf33790a28643ab058b507b35cBen Cheng &reloc_symtab, scn, shdr, tscn, 62825b3c049e70834cf33790a28643ab058b507b35cBen Cheng debug, !debug); 62925b3c049e70834cf33790a28643ab058b507b35cBen Cheng } 63025b3c049e70834cf33790a28643ab058b507b35cBen Cheng } 63125b3c049e70834cf33790a28643ab058b507b35cBen Cheng 63225b3c049e70834cf33790a28643ab058b507b35cBen Cheng return result; 63325b3c049e70834cf33790a28643ab058b507b35cBen Cheng} 63425b3c049e70834cf33790a28643ab058b507b35cBen Cheng 63525b3c049e70834cf33790a28643ab058b507b35cBen ChengDwfl_Error 63625b3c049e70834cf33790a28643ab058b507b35cBen Chenginternal_function 63725b3c049e70834cf33790a28643ab058b507b35cBen Cheng__libdwfl_relocate_section (Dwfl_Module *mod, Elf *relocated, 63825b3c049e70834cf33790a28643ab058b507b35cBen Cheng Elf_Scn *relocscn, Elf_Scn *tscn, bool partial) 63925b3c049e70834cf33790a28643ab058b507b35cBen Cheng{ 64025b3c049e70834cf33790a28643ab058b507b35cBen Cheng GElf_Ehdr ehdr_mem; 64125b3c049e70834cf33790a28643ab058b507b35cBen Cheng GElf_Shdr shdr_mem; 64225b3c049e70834cf33790a28643ab058b507b35cBen Cheng 64325b3c049e70834cf33790a28643ab058b507b35cBen Cheng RELOC_SYMTAB_CACHE (reloc_symtab); 64425b3c049e70834cf33790a28643ab058b507b35cBen Cheng 64525b3c049e70834cf33790a28643ab058b507b35cBen Cheng size_t shstrndx; 64625b3c049e70834cf33790a28643ab058b507b35cBen Cheng if (elf_getshdrstrndx (relocated, &shstrndx) < 0) 64725b3c049e70834cf33790a28643ab058b507b35cBen Cheng return DWFL_E_LIBELF; 64825b3c049e70834cf33790a28643ab058b507b35cBen Cheng 64925b3c049e70834cf33790a28643ab058b507b35cBen Cheng return (__libdwfl_module_getebl (mod) 65025b3c049e70834cf33790a28643ab058b507b35cBen Cheng ?: relocate_section (mod, relocated, 65125b3c049e70834cf33790a28643ab058b507b35cBen Cheng gelf_getehdr (relocated, &ehdr_mem), shstrndx, 65225b3c049e70834cf33790a28643ab058b507b35cBen Cheng &reloc_symtab, 65325b3c049e70834cf33790a28643ab058b507b35cBen Cheng relocscn, gelf_getshdr (relocscn, &shdr_mem), 65425b3c049e70834cf33790a28643ab058b507b35cBen Cheng tscn, false, partial)); 65525b3c049e70834cf33790a28643ab058b507b35cBen Cheng} 656