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/*
* CRIS ELF shared library loader support.
*
* Program to load an elf binary on a linux system, and run it.
* References to symbols in sharable libraries can be resolved
* by either an ELF sharable library or a linux style of shared
* library.
*
* Copyright (C) 2002-2004, Axis Communications AB
* All rights reserved
*
* Author: Tobias Anderberg, <tobiasa@axis.com>
*
* 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.
*/
#include "ldso.h"
/* Defined in resolve.S. */
extern int _dl_linux_resolve(void);
unsigned long
_dl_linux_resolver(struct elf_resolve *tpnt, int reloc_entry)
{
int symtab_index;
char *strtab;
char *symname;
char *new_addr;
char *rel_addr;
char **got_addr;
Elf32_Sym *symtab;
ELF_RELOC *this_reloc;
unsigned long instr_addr;
rel_addr = (char *)tpnt->dynamic_info[DT_JMPREL];
this_reloc = (ELF_RELOC *)(intptr_t)(rel_addr + reloc_entry);
symtab_index = ELF32_R_SYM(this_reloc->r_info);
symtab = (Elf32_Sym *)(intptr_t)tpnt->dynamic_info[DT_SYMTAB];
strtab = (char *)tpnt->dynamic_info[DT_STRTAB];
symname = strtab + symtab[symtab_index].st_name;
/* Address of the jump instruction to fix up. */
instr_addr = ((unsigned long)this_reloc->r_offset +
(unsigned long)tpnt->loadaddr);
got_addr = (char **)instr_addr;
/* Get the address of the GOT entry. */
new_addr = _dl_find_hash(symname, tpnt->symbol_scope, tpnt, ELF_RTYPE_CLASS_PLT);
if (unlikely(!new_addr)) {
_dl_dprintf(2, "%s: Can't resolve symbol '%s'\n", _dl_progname, symname);
_dl_exit(1);
}
#if defined (__SUPPORT_LD_DEBUG__)
if (_dl_debug_bindings) {
_dl_dprintf(_dl_debug_file, "\nresolve function: %s", symname);
if (_dl_debug_detail)
_dl_dprintf(_dl_debug_file,
"\n\tpatched: %x ==> %x @ %x",
*got_addr, new_addr, got_addr);
}
if (!_dl_debug_nofixups) {
*got_addr = new_addr;
}
#else
*got_addr = new_addr;
#endif
return (unsigned long)new_addr;
}
static int
_dl_parse(struct elf_resolve *tpnt, struct dyn_elf *scope,
unsigned long rel_addr, unsigned long rel_size,
int (*reloc_fnc)(struct elf_resolve *tpnt, struct dyn_elf *scope,
ELF_RELOC *rpnt, Elf32_Sym *symtab, char *strtab))
{
int symtab_index;
unsigned int i;
char *strtab;
Elf32_Sym *symtab;
ELF_RELOC *rpnt;
/* Parse the relocation information. */
rpnt = (ELF_RELOC *)(intptr_t)rel_addr;
rel_size /= sizeof(ELF_RELOC);
symtab = (Elf32_Sym *)(intptr_t)tpnt->dynamic_info[DT_SYMTAB];
strtab = (char *)tpnt->dynamic_info[DT_STRTAB];
for (i = 0; i < rel_size; i++, rpnt++) {
int res;
symtab_index = ELF32_R_SYM(rpnt->r_info);
debug_sym(symtab, strtab, symtab_index);
debug_reloc(symtab, strtab, rpnt);
/* Pass over to actual relocation function. */
res = reloc_fnc(tpnt, scope, rpnt, symtab, strtab);
if (res == 0)
continue;
_dl_dprintf(2, "\n%s: ", _dl_progname);
if (symtab_index)
_dl_dprintf(2, "symbol '%s': ",
strtab + symtab[symtab_index].st_name);
if (unlikely(res < 0)) {
int reloc_type = ELF32_R_TYPE(rpnt->r_info);
#if defined (__SUPPORT_LD_DEBUG__)
_dl_dprintf(2, "can't handle reloc type %s\n",
_dl_reltypes(reloc_type));
#else
_dl_dprintf(2, "can't handle reloc type %x\n",
reloc_type);
#endif
_dl_exit(-res);
} else if (unlikely(res > 0)) {
_dl_dprintf(2, "can't resolve symbol\n");
return res;
}
}
return 0;
}
static int
_dl_do_reloc(struct elf_resolve *tpnt, struct dyn_elf *scope,
ELF_RELOC *rpnt, Elf32_Sym *symtab, char *strtab)
{
int reloc_type;
int symtab_index;
char *symname;
unsigned long *reloc_addr;
unsigned long symbol_addr;
#if defined (__SUPPORT_LD_DEBUG__)
unsigned long old_val;
#endif
reloc_addr = (unsigned long *)(intptr_t)(tpnt->loadaddr + (unsigned long)rpnt->r_offset);
reloc_type = ELF32_R_TYPE(rpnt->r_info);
symtab_index = ELF32_R_SYM(rpnt->r_info);
symbol_addr = 0;
symname = strtab + symtab[symtab_index].st_name;
if (symtab_index) {
if (symtab[symtab_index].st_shndx != SHN_UNDEF &&
ELF32_ST_BIND(symtab[symtab_index].st_info) == STB_LOCAL) {
symbol_addr = (unsigned long)tpnt->loadaddr;
} else {
symbol_addr = (unsigned long)_dl_find_hash(symname, scope, tpnt,
elf_machine_type_class(reloc_type));
}
if (unlikely(!symbol_addr && ELF32_ST_BIND(symtab[symtab_index].st_info) != STB_WEAK)) {
_dl_dprintf(2, "%s: can't resolve symbol '%s'\n", _dl_progname, symname);
_dl_exit(1);
}
symbol_addr += rpnt->r_addend;
}
#if defined (__SUPPORT_LD_DEBUG__)
old_val = *reloc_addr;
#endif
switch (reloc_type) {
case R_CRIS_NONE:
break;
case R_CRIS_GLOB_DAT:
case R_CRIS_JUMP_SLOT:
case R_CRIS_32:
*reloc_addr = symbol_addr;
break;
case R_CRIS_COPY:
#if defined (__SUPPORT_LD_DEBUG__)
if (_dl_debug_move)
_dl_dprintf(_dl_debug_file,
"\n%s move %d bytes from %x to %x",
symname, symtab[symtab_index].st_size,
symbol_addr, reloc_addr);
#endif
_dl_memcpy((char *)reloc_addr,
(char *)symbol_addr,
symtab[symtab_index].st_size);
break;
case R_CRIS_RELATIVE:
*reloc_addr = (unsigned long)tpnt->loadaddr + rpnt->r_addend;
break;
default:
return -1; /* Calls _dl_exit(1). */
}
#if defined (__SUPPORT_LD_DEBUG__)
if (_dl_debug_reloc && _dl_debug_detail)
_dl_dprintf(_dl_debug_file, "\n\tpatched: %x ==> %x @ %x",
old_val, *reloc_addr, reloc_addr);
#endif
return 0;
}
static int
_dl_do_lazy_reloc(struct elf_resolve *tpnt, struct dyn_elf *scope,
ELF_RELOC *rpnt, Elf32_Sym *symtab, char *strtab)
{
int reloc_type;
unsigned long *reloc_addr;
#if defined (__SUPPORT_LD_DEBUG__)
unsigned long old_val;
#endif
/* Don't care about these, just keep the compiler happy. */
(void)scope;
(void)symtab;
(void)strtab;
reloc_addr = (unsigned long *)(intptr_t)(tpnt->loadaddr + (unsigned long)rpnt->r_offset);
reloc_type = ELF32_R_TYPE(rpnt->r_info);
#if defined (__SUPPORT_LD_DEBUG__)
old_val = *reloc_addr;
#endif
switch (reloc_type) {
case R_CRIS_NONE:
break;
case R_CRIS_JUMP_SLOT:
*reloc_addr += (unsigned long)tpnt->loadaddr;
break;
default:
return -1; /* Calls _dl_exit(1). */
}
#if defined (__SUPPORT_LD_DEBUG__)
if (_dl_debug_reloc && _dl_debug_detail)
_dl_dprintf(_dl_debug_file, "\n\tpatched: %x ==> %x @ %x",
old_val, *reloc_addr, reloc_addr);
#endif
return 0;
}
/* External interface to the generic part of the dynamic linker. */
void
_dl_parse_lazy_relocation_information(struct dyn_elf *rpnt,
unsigned long rel_addr,
unsigned long rel_size)
{
(void)_dl_parse(rpnt->dyn, NULL, rel_addr, rel_size, _dl_do_lazy_reloc);
}
int
_dl_parse_relocation_information(struct dyn_elf *rpnt,
unsigned long rel_addr,
unsigned long rel_size)
{
return _dl_parse(rpnt->dyn, rpnt->dyn->symbol_scope, rel_addr, rel_size, _dl_do_reloc);
}
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