| 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; |
| } |
| |
| /** @} |
| */ |