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Rev | Author | Line No. | Line |
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854 | bondari | 1 | /* |
2071 | jermar | 2 | * Copyright (c) 2006 Sergey Bondari |
3 | * Copyright (c) 2006 Jakub Jermar |
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854 | bondari | 4 | * All rights reserved. |
5 | * |
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6 | * Redistribution and use in source and binary forms, with or without |
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7 | * modification, are permitted provided that the following conditions |
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8 | * are met: |
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9 | * |
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10 | * - Redistributions of source code must retain the above copyright |
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11 | * notice, this list of conditions and the following disclaimer. |
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12 | * - Redistributions in binary form must reproduce the above copyright |
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13 | * notice, this list of conditions and the following disclaimer in the |
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14 | * documentation and/or other materials provided with the distribution. |
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15 | * - The name of the author may not be used to endorse or promote products |
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16 | * derived from this software without specific prior written permission. |
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17 | * |
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18 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
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19 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
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20 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
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21 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
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22 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
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23 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
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24 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
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25 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
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26 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
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27 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
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28 | */ |
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29 | |||
1757 | jermar | 30 | /** @addtogroup generic |
1702 | cejka | 31 | * @{ |
32 | */ |
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33 | |||
1264 | jermar | 34 | /** |
1702 | cejka | 35 | * @file |
1264 | jermar | 36 | * @brief Kernel ELF loader. |
37 | */ |
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38 | |||
2000 | decky | 39 | #include <lib/elf.h> |
938 | jermar | 40 | #include <debug.h> |
41 | #include <arch/types.h> |
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42 | #include <mm/as.h> |
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43 | #include <mm/frame.h> |
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952 | jermar | 44 | #include <mm/slab.h> |
938 | jermar | 45 | #include <align.h> |
952 | jermar | 46 | #include <memstr.h> |
47 | #include <macros.h> |
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1409 | jermar | 48 | #include <arch.h> |
854 | bondari | 49 | |
938 | jermar | 50 | static char *error_codes[] = { |
51 | "no error", |
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52 | "invalid image", |
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53 | "address space error", |
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54 | "incompatible image", |
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55 | "unsupported image type", |
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56 | "irrecoverable error" |
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57 | }; |
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58 | |||
952 | jermar | 59 | static int segment_header(elf_segment_header_t *entry, elf_header_t *elf, as_t *as); |
60 | static int section_header(elf_section_header_t *entry, elf_header_t *elf, as_t *as); |
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61 | static int load_segment(elf_segment_header_t *entry, elf_header_t *elf, as_t *as); |
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938 | jermar | 62 | |
63 | /** ELF loader |
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854 | bondari | 64 | * |
65 | * @param header Pointer to ELF header in memory |
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66 | * @param as Created and properly mapped address space |
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67 | * @return EE_OK on success |
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68 | */ |
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938 | jermar | 69 | int elf_load(elf_header_t *header, as_t * as) |
70 | { |
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71 | int i, rc; |
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910 | bondari | 72 | |
73 | /* Identify ELF */ |
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938 | jermar | 74 | if (header->e_ident[EI_MAG0] != ELFMAG0 || header->e_ident[EI_MAG1] != ELFMAG1 || |
75 | header->e_ident[EI_MAG2] != ELFMAG2 || header->e_ident[EI_MAG3] != ELFMAG3) { |
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910 | bondari | 76 | return EE_INVALID; |
77 | } |
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78 | |||
79 | /* Identify ELF compatibility */ |
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938 | jermar | 80 | if (header->e_ident[EI_DATA] != ELF_DATA_ENCODING || header->e_machine != ELF_MACHINE || |
81 | header->e_ident[EI_VERSION] != EV_CURRENT || header->e_version != EV_CURRENT || |
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82 | header->e_ident[EI_CLASS] != ELF_CLASS) { |
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83 | return EE_INCOMPATIBLE; |
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84 | } |
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85 | |||
952 | jermar | 86 | if (header->e_phentsize != sizeof(elf_segment_header_t)) |
938 | jermar | 87 | return EE_INCOMPATIBLE; |
88 | |||
952 | jermar | 89 | if (header->e_shentsize != sizeof(elf_section_header_t)) |
90 | return EE_INCOMPATIBLE; |
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91 | |||
938 | jermar | 92 | /* Check if the object type is supported. */ |
93 | if (header->e_type != ET_EXEC) |
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910 | bondari | 94 | return EE_UNSUPPORTED; |
938 | jermar | 95 | |
952 | jermar | 96 | /* Walk through all segment headers and process them. */ |
938 | jermar | 97 | for (i = 0; i < header->e_phnum; i++) { |
1780 | jermar | 98 | rc = segment_header(&((elf_segment_header_t *)(((uint8_t *) header) + header->e_phoff))[i], header, as); |
938 | jermar | 99 | if (rc != EE_OK) |
100 | return rc; |
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910 | bondari | 101 | } |
938 | jermar | 102 | |
952 | jermar | 103 | /* Inspect all section headers and proccess them. */ |
104 | for (i = 0; i < header->e_shnum; i++) { |
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1780 | jermar | 105 | rc = section_header(&((elf_section_header_t *)(((uint8_t *) header) + header->e_shoff))[i], header, as); |
952 | jermar | 106 | if (rc != EE_OK) |
107 | return rc; |
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108 | } |
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109 | |||
938 | jermar | 110 | return EE_OK; |
111 | } |
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112 | |||
113 | /** Print error message according to error code. |
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114 | * |
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115 | * @param rc Return code returned by elf_load(). |
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116 | * |
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117 | * @return NULL terminated description of error. |
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118 | */ |
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119 | char *elf_error(int rc) |
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120 | { |
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121 | ASSERT(rc < sizeof(error_codes)/sizeof(char *)); |
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122 | |||
123 | return error_codes[rc]; |
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124 | } |
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125 | |||
952 | jermar | 126 | /** Process segment header. |
938 | jermar | 127 | * |
952 | jermar | 128 | * @param entry Segment header. |
129 | * @param elf ELF header. |
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938 | jermar | 130 | * @param as Address space into wich the ELF is being loaded. |
131 | * |
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132 | * @return EE_OK on success, error code otherwise. |
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133 | */ |
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952 | jermar | 134 | static int segment_header(elf_segment_header_t *entry, elf_header_t *elf, as_t *as) |
938 | jermar | 135 | { |
136 | switch (entry->p_type) { |
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2062 | jermar | 137 | case PT_NULL: |
138 | case PT_PHDR: |
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938 | jermar | 139 | break; |
2062 | jermar | 140 | case PT_LOAD: |
952 | jermar | 141 | return load_segment(entry, elf, as); |
938 | jermar | 142 | break; |
2062 | jermar | 143 | case PT_DYNAMIC: |
144 | case PT_INTERP: |
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145 | case PT_SHLIB: |
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146 | case PT_NOTE: |
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147 | case PT_LOPROC: |
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148 | case PT_HIPROC: |
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149 | default: |
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938 | jermar | 150 | return EE_UNSUPPORTED; |
151 | break; |
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152 | } |
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153 | return EE_OK; |
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154 | } |
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155 | |||
156 | /** Load segment described by program header entry. |
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157 | * |
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158 | * @param entry Program header entry describing segment to be loaded. |
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952 | jermar | 159 | * @param elf ELF header. |
1248 | jermar | 160 | * @param as Address space into wich the ELF is being loaded. |
938 | jermar | 161 | * |
162 | * @return EE_OK on success, error code otherwise. |
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163 | */ |
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952 | jermar | 164 | int load_segment(elf_segment_header_t *entry, elf_header_t *elf, as_t *as) |
938 | jermar | 165 | { |
166 | as_area_t *a; |
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1409 | jermar | 167 | int flags = 0; |
1425 | jermar | 168 | mem_backend_data_t backend_data; |
169 | |||
170 | backend_data.elf = elf; |
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171 | backend_data.segment = entry; |
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938 | jermar | 172 | |
173 | if (entry->p_align > 1) { |
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174 | if ((entry->p_offset % entry->p_align) != (entry->p_vaddr % entry->p_align)) { |
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175 | return EE_INVALID; |
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176 | } |
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177 | } |
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178 | |||
1026 | jermar | 179 | if (entry->p_flags & PF_X) |
180 | flags |= AS_AREA_EXEC; |
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181 | if (entry->p_flags & PF_W) |
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182 | flags |= AS_AREA_WRITE; |
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183 | if (entry->p_flags & PF_R) |
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184 | flags |= AS_AREA_READ; |
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1424 | jermar | 185 | flags |= AS_AREA_CACHEABLE; |
910 | bondari | 186 | |
952 | jermar | 187 | /* |
188 | * Check if the virtual address starts on page boundary. |
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189 | */ |
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190 | if (ALIGN_UP(entry->p_vaddr, PAGE_SIZE) != entry->p_vaddr) |
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191 | return EE_UNSUPPORTED; |
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192 | |||
1424 | jermar | 193 | a = as_area_create(as, flags, entry->p_memsz, entry->p_vaddr, AS_AREA_ATTR_NONE, |
194 | &elf_backend, &backend_data); |
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938 | jermar | 195 | if (!a) |
1070 | jermar | 196 | return EE_MEMORY; |
938 | jermar | 197 | |
1409 | jermar | 198 | /* |
199 | * The segment will be mapped on demand by elf_page_fault(). |
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200 | */ |
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201 | |||
938 | jermar | 202 | return EE_OK; |
854 | bondari | 203 | } |
952 | jermar | 204 | |
205 | /** Process section header. |
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206 | * |
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207 | * @param entry Segment header. |
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208 | * @param elf ELF header. |
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209 | * @param as Address space into wich the ELF is being loaded. |
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210 | * |
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211 | * @return EE_OK on success, error code otherwise. |
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212 | */ |
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213 | static int section_header(elf_section_header_t *entry, elf_header_t *elf, as_t *as) |
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214 | { |
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215 | switch (entry->sh_type) { |
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2062 | jermar | 216 | default: |
952 | jermar | 217 | break; |
218 | } |
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219 | |||
220 | return EE_OK; |
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221 | } |
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1702 | cejka | 222 | |
1757 | jermar | 223 | /** @} |
1702 | cejka | 224 | */ |