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| Rev | Author | Line No. | Line |
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| 2973 | svoboda | 1 | /* |
| 2 | * Copyright (c) 2008 Jiri Svoboda |
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| 3 | * All rights reserved. |
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| 4 | * |
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| 5 | * Redistribution and use in source and binary forms, with or without |
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| 6 | * modification, are permitted provided that the following conditions |
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| 7 | * are met: |
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| 8 | * |
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| 9 | * - Redistributions of source code must retain the above copyright |
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| 10 | * notice, this list of conditions and the following disclaimer. |
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| 11 | * - Redistributions in binary form must reproduce the above copyright |
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| 12 | * notice, this list of conditions and the following disclaimer in the |
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| 13 | * documentation and/or other materials provided with the distribution. |
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| 14 | * - The name of the author may not be used to endorse or promote products |
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| 15 | * derived from this software without specific prior written permission. |
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| 16 | * |
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| 17 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
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| 18 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
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| 19 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
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| 20 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
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| 21 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
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| 22 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
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| 23 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
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| 24 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
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| 25 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
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| 26 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
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| 27 | */ |
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| 28 | |||
| 29 | /** @addtogroup rtld rtld |
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| 30 | * @brief |
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| 31 | * @{ |
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| 32 | */ |
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| 33 | /** |
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| 34 | * @file |
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| 35 | */ |
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| 36 | |||
| 37 | #include <stdio.h> |
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| 38 | |||
| 39 | #include <arch.h> |
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| 40 | #include <elf_dyn.h> |
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| 2978 | svoboda | 41 | #include <symbol.h> |
| 2973 | svoboda | 42 | #include <rtld.h> |
| 43 | |||
| 44 | /** |
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| 45 | * Process (fixup) all relocations in a relocation table. |
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| 46 | */ |
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| 2980 | svoboda | 47 | void rel_table_process(module_t *m, elf_rel_t *rt, size_t rt_size) |
| 2973 | svoboda | 48 | { |
| 49 | int i; |
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| 50 | |||
| 51 | size_t rt_entries; |
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| 52 | size_t r_offset; |
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| 53 | elf_word r_info; |
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| 54 | unsigned rel_type; |
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| 55 | elf_word sym_idx; |
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| 2978 | svoboda | 56 | uintptr_t sym_addr; |
| 2973 | svoboda | 57 | |
| 58 | elf_symbol_t *sym_table; |
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| 59 | elf_symbol_t *sym; |
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| 60 | uint32_t *r_ptr; |
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| 61 | char *str_tab; |
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| 2978 | svoboda | 62 | |
| 63 | elf_symbol_t *sym_def; |
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| 2980 | svoboda | 64 | module_t *dest; |
| 2973 | svoboda | 65 | |
| 66 | printf("parse relocation table\n"); |
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| 67 | |||
| 68 | sym_table = m->dyn.sym_tab; |
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| 69 | rt_entries = rt_size / sizeof(elf_rel_t); |
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| 70 | str_tab = m->dyn.str_tab; |
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| 71 | |||
| 72 | printf("address: 0x%x, entries: %d\n", (uintptr_t)rt, rt_entries); |
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| 73 | |||
| 74 | for (i = 0; i < rt_entries; ++i) { |
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| 75 | printf("symbol %d: ", i); |
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| 76 | r_offset = rt[i].r_offset; |
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| 77 | r_info = rt[i].r_info; |
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| 78 | |||
| 79 | sym_idx = ELF32_R_SYM(r_info); |
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| 80 | sym = &sym_table[sym_idx]; |
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| 81 | |||
| 82 | printf("name '%s', value 0x%x, size 0x%x\n", |
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| 83 | str_tab + sym->st_name, |
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| 84 | sym->st_value, |
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| 85 | sym->st_size); |
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| 86 | |||
| 87 | rel_type = ELF32_R_TYPE(r_info); |
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| 2978 | svoboda | 88 | r_ptr = (uint32_t *)(r_offset + m->bias); |
| 2973 | svoboda | 89 | |
| 2982 | svoboda | 90 | if (sym->st_name != 0) { |
| 91 | printf("rel_type: %x, rel_offset: 0x%x\n", rel_type, r_offset); |
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| 92 | sym_def = symbol_def_find(str_tab + sym->st_name, &dest); |
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| 93 | printf("dest name: '%s'\n", dest->dyn.soname); |
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| 94 | printf("dest bias: 0x%x\n", dest->bias); |
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| 95 | if (sym_def) { |
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| 96 | sym_addr = sym_def->st_value + dest->bias; |
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| 97 | printf("symbol definition found, addr=0x%x\n", sym_addr); |
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| 98 | } else { |
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| 99 | printf("symbol definition not found\n"); |
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| 100 | continue; |
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| 101 | } |
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| 2978 | svoboda | 102 | } |
| 103 | |||
| 2973 | svoboda | 104 | switch (rel_type) { |
| 105 | case R_386_GLOB_DAT: |
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| 106 | case R_386_JUMP_SLOT: |
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| 2978 | svoboda | 107 | printf("fixup R_386_GLOB_DAT/JUMP_SLOT (b+v)\n"); |
| 2973 | svoboda | 108 | *r_ptr = sym_addr; |
| 109 | break; |
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| 110 | |||
| 111 | case R_386_32: |
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| 2978 | svoboda | 112 | printf("fixup R_386_32 (b+v+a)\n"); |
| 2973 | svoboda | 113 | *r_ptr += sym_addr; |
| 114 | break; |
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| 115 | |||
| 116 | case R_386_RELATIVE: |
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| 2978 | svoboda | 117 | printf("fixup R_386_RELATIVE (b+a)\n"); |
| 2980 | svoboda | 118 | *r_ptr += m->bias; |
| 2973 | svoboda | 119 | break; |
| 2978 | svoboda | 120 | } |
| 2973 | svoboda | 121 | } |
| 122 | |||
| 123 | } |
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| 124 | |||
| 125 | /** @} |
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| 126 | */ |