0,0 → 1,251 |
/* |
* Copyright (c) 2008 Jiri Svoboda |
* All rights reserved. |
* |
* Redistribution and use in source and binary forms, with or without |
* modification, are permitted provided that the following conditions |
* are met: |
* |
* - Redistributions of source code must retain the above copyright |
* notice, this list of conditions and the following disclaimer. |
* - Redistributions in binary form must reproduce the above copyright |
* notice, this list of conditions and the following disclaimer in the |
* documentation and/or other materials provided with the distribution. |
* - The name of the author may not be used to endorse or promote products |
* derived from this software without specific prior written permission. |
* |
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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. |
*/ |
|
/** @addtogroup rtld rtld |
* @brief |
* @{ |
*/ |
/** |
* @file |
*/ |
|
#include <stdio.h> |
#include <stdlib.h> |
|
#include <arch.h> |
#include <elf_dyn.h> |
#include <symbol.h> |
#include <rtld.h> |
|
void module_process_pre_arch(module_t *m) |
{ |
elf_symbol_t *sym_table; |
elf_symbol_t *sym_def; |
elf_symbol_t *sym; |
uint32_t gotsym; |
uint32_t *got; |
char *str_tab; |
int i; |
|
uint32_t sym_addr; |
module_t *dest; |
|
got = (uint32_t *) m->dyn.plt_got; |
sym_table = m->dyn.sym_tab; |
str_tab = m->dyn.str_tab; |
gotsym = m->dyn.arch.gotsym; |
|
DPRINTF("** Relocate GOT entries **\n"); |
DPRINTF("MIPS base = 0x%x\n", m->dyn.arch.base); |
|
/* |
* Local entries. |
*/ |
for (i = 0; i < gotsym; i++) { |
/* FIXME: really subtract MIPS base? */ |
got[i] += m->bias - m->dyn.arch.base; |
} |
|
DPRINTF("sym_ent = %d, gotsym = %d\n", m->dyn.arch.sym_no, gotsym); |
|
/* |
* Global entries. |
*/ |
for (i = gotsym; i < m->dyn.arch.sym_no; i++) { |
DPRINTF("relocate GOT entry %d\n", i); |
// getchar(); |
|
sym = &sym_table[i]; |
if (ELF32_R_TYPE(sym->st_info) == STT_FUNC) { |
if (sym->st_shndx == SHN_UNDEF) { |
if (sym->st_value == 0) { |
/* 1 */ |
} else { |
if (got[i] == sym->st_value) { |
/* 2 */ |
DPRINTF("(2)\n"); |
got[i] += m->bias - m->dyn.arch.base; |
continue; |
} else { |
/* 3 */ |
DPRINTF("(3)\n"); |
got[i] = sym->st_value + m->bias - m->dyn.arch.base; |
continue; |
} |
} |
} else { |
/* 2 */ |
DPRINTF("(2)\n"); |
got[i] += m->bias - m->dyn.arch.base; |
continue; |
} |
} else { |
if (sym->st_shndx == SHN_UNDEF || |
sym->st_shndx == SHN_COMMON) { |
/* 1 */ |
} else { |
/* 1 */ |
} |
} |
|
DPRINTF("(1) symbol name='%s'\n", str_tab + sym->st_name); |
sym_def = symbol_def_find(str_tab + sym->st_name, m, &dest); |
if (sym_def) { |
sym_addr = symbol_get_addr(sym_def, dest); |
DPRINTF("symbol definition found, addr=0x%x\n", sym_addr); |
} else { |
DPRINTF("symbol definition not found\n"); |
continue; |
} |
DPRINTF("write 0x%x at 0x%x\n", sym_addr, (uint32_t) &got[i]); |
// getchar(); |
got[i] = sym_addr; |
} |
|
DPRINTF("** Done **\n"); |
} |
|
/** |
* Process (fixup) all relocations in a relocation table. |
*/ |
void rel_table_process(module_t *m, elf_rel_t *rt, size_t rt_size) |
{ |
int i; |
|
size_t rt_entries; |
size_t r_offset; |
elf_word r_info; |
unsigned rel_type; |
elf_word sym_idx; |
uintptr_t sym_addr; |
|
elf_symbol_t *sym_table; |
elf_symbol_t *sym; |
uint32_t *r_ptr; |
uint16_t *r_ptr16; |
char *str_tab; |
|
elf_symbol_t *sym_def; |
module_t *dest; |
|
uint32_t *got; |
uint32_t gotsym; |
uint32_t ea; |
|
DPRINTF("parse relocation table\n"); |
|
sym_table = m->dyn.sym_tab; |
rt_entries = rt_size / sizeof(elf_rela_t); |
str_tab = m->dyn.str_tab; |
got = (uint32_t *) m->dyn.plt_got; |
gotsym = m->dyn.arch.gotsym; |
|
DPRINTF("got=0x%lx, gotsym=%d\n", (uintptr_t) got, gotsym); |
|
DPRINTF("address: 0x%x, entries: %d\n", (uintptr_t)rt, rt_entries); |
|
for (i = 0; i < rt_entries; ++i) { |
DPRINTF("symbol %d: ", i); |
r_offset = rt[i].r_offset; |
r_info = rt[i].r_info; |
|
sym_idx = ELF32_R_SYM(r_info); |
sym = &sym_table[sym_idx]; |
|
DPRINTF("name '%s', value 0x%x, size 0x%x\n", |
str_tab + sym->st_name, |
sym->st_value, |
sym->st_size); |
|
rel_type = ELF32_R_TYPE(r_info); |
r_ptr = (uint32_t *)(r_offset + m->bias); |
r_ptr16 = (uint16_t *)(r_offset + m->bias); |
|
if (sym->st_name != 0) { |
DPRINTF("rel_type: %x, rel_offset: 0x%x\n", rel_type, r_offset); |
DPRINTF("dest name: '%s'\n", dest->dyn.soname); |
DPRINTF("dest bias: 0x%x\n", dest->bias); |
if (sym_def) { |
sym_addr = symbol_get_addr(sym_def, dest); |
DPRINTF("symbol definition found, addr=0x%x\n", sym_addr); |
} else { |
DPRINTF("symbol definition not found\n"); |
continue; |
} |
} |
|
DPRINTF("switch(%u)\n", rel_type); |
|
switch (rel_type) { |
case R_MIPS_NONE: |
DPRINTF("Ignoring R_MIPS_NONE\n"); |
break; |
|
case R_MIPS_REL32: |
DPRINTF("fixup R_MIPS_REL32 (r - ea + s)\n"); |
if (sym_idx < gotsym) |
ea = sym_addr; |
else |
ea = got[sym_idx]; |
|
*r_ptr += sym_addr - ea; |
DPRINTF("p = 0x%x, val := 0x%x\n", (uint32_t) r_ptr, |
*r_ptr); |
// getchar(); |
break; |
|
/* No other non-TLS relocation types should appear. */ |
|
case R_MIPS_TLS_DTPMOD32: |
/* |
* We can ignore this as long as the only module |
* with TLS variables is libc.so. |
*/ |
DPRINTF("Ignoring R_MIPS_DTPMOD32\n"); |
break; |
|
default: |
printf("Error: Unknown relocation type %d.\n", |
rel_type); |
exit(1); |
break; |
} |
} |
|
|
printf("relocation done\n"); |
} |
|
void rela_table_process(module_t *m, elf_rela_t *rt, size_t rt_size) |
{ |
/* Unused */ |
(void)m; (void)rt; (void)rt_size; |
} |
|
/** @} |
*/ |