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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 | |||
2996 | svoboda | 44 | void module_process_pre_arch(module_t *m) |
45 | { |
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46 | /* Unused */ |
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47 | } |
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48 | |||
49 | |||
2973 | svoboda | 50 | /** |
51 | * Process (fixup) all relocations in a relocation table. |
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52 | */ |
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2980 | svoboda | 53 | void rel_table_process(module_t *m, elf_rel_t *rt, size_t rt_size) |
2973 | svoboda | 54 | { |
55 | int i; |
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56 | |||
57 | size_t rt_entries; |
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58 | size_t r_offset; |
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59 | elf_word r_info; |
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60 | unsigned rel_type; |
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61 | elf_word sym_idx; |
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2978 | svoboda | 62 | uintptr_t sym_addr; |
2973 | svoboda | 63 | |
64 | elf_symbol_t *sym_table; |
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65 | elf_symbol_t *sym; |
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66 | uint32_t *r_ptr; |
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67 | char *str_tab; |
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2978 | svoboda | 68 | |
69 | elf_symbol_t *sym_def; |
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2980 | svoboda | 70 | module_t *dest; |
2973 | svoboda | 71 | |
72 | printf("parse relocation table\n"); |
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73 | |||
74 | sym_table = m->dyn.sym_tab; |
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75 | rt_entries = rt_size / sizeof(elf_rel_t); |
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76 | str_tab = m->dyn.str_tab; |
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77 | |||
78 | printf("address: 0x%x, entries: %d\n", (uintptr_t)rt, rt_entries); |
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79 | |||
80 | for (i = 0; i < rt_entries; ++i) { |
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2983 | svoboda | 81 | // printf("symbol %d: ", i); |
2973 | svoboda | 82 | r_offset = rt[i].r_offset; |
83 | r_info = rt[i].r_info; |
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84 | |||
85 | sym_idx = ELF32_R_SYM(r_info); |
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86 | sym = &sym_table[sym_idx]; |
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87 | |||
2983 | svoboda | 88 | /* printf("name '%s', value 0x%x, size 0x%x\n", |
2973 | svoboda | 89 | str_tab + sym->st_name, |
90 | sym->st_value, |
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91 | sym->st_size); |
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2983 | svoboda | 92 | */ |
2973 | svoboda | 93 | rel_type = ELF32_R_TYPE(r_info); |
2978 | svoboda | 94 | r_ptr = (uint32_t *)(r_offset + m->bias); |
2973 | svoboda | 95 | |
2982 | svoboda | 96 | if (sym->st_name != 0) { |
2983 | svoboda | 97 | // printf("rel_type: %x, rel_offset: 0x%x\n", rel_type, r_offset); |
2999 | svoboda | 98 | sym_def = symbol_def_find(str_tab + sym->st_name, |
99 | m, &dest); |
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2983 | svoboda | 100 | // printf("dest name: '%s'\n", dest->dyn.soname); |
101 | // printf("dest bias: 0x%x\n", dest->bias); |
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2982 | svoboda | 102 | if (sym_def) { |
2998 | svoboda | 103 | sym_addr = symbol_get_addr(sym_def, dest); |
2983 | svoboda | 104 | // printf("symbol definition found, addr=0x%x\n", sym_addr); |
2982 | svoboda | 105 | } else { |
106 | printf("symbol definition not found\n"); |
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107 | continue; |
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108 | } |
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2978 | svoboda | 109 | } |
110 | |||
2973 | svoboda | 111 | switch (rel_type) { |
112 | case R_386_GLOB_DAT: |
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113 | case R_386_JUMP_SLOT: |
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2983 | svoboda | 114 | // printf("fixup R_386_GLOB_DAT/JUMP_SLOT (b+v)\n"); |
2973 | svoboda | 115 | *r_ptr = sym_addr; |
116 | break; |
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117 | |||
118 | case R_386_32: |
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2983 | svoboda | 119 | // printf("fixup R_386_32 (b+v+a)\n"); |
2973 | svoboda | 120 | *r_ptr += sym_addr; |
121 | break; |
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122 | |||
123 | case R_386_RELATIVE: |
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2983 | svoboda | 124 | // printf("fixup R_386_RELATIVE (b+a)\n"); |
2980 | svoboda | 125 | *r_ptr += m->bias; |
2973 | svoboda | 126 | break; |
2978 | svoboda | 127 | } |
2973 | svoboda | 128 | } |
129 | |||
130 | } |
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131 | |||
2996 | svoboda | 132 | void rela_table_process(module_t *m, elf_rela_t *rt, size_t rt_size) |
133 | { |
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134 | /* Unused */ |
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135 | (void)m; (void)rt; (void)rt_size; |
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136 | } |
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137 | |||
2973 | svoboda | 138 | /** @} |
139 | */ |