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| Rev | Author | Line No. | Line |
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| 854 | bondari | 1 | /* |
| 2 | * Copyright (C) 2006 Sergey Bondari |
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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 | |||
| 910 | bondari | 29 | #include <elf.h> |
| 938 | jermar | 30 | #include <debug.h> |
| 31 | #include <arch/types.h> |
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| 32 | #include <typedefs.h> |
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| 33 | #include <mm/as.h> |
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| 34 | #include <mm/frame.h> |
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| 35 | #include <print.h> |
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| 36 | #include <align.h> |
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| 854 | bondari | 37 | |
| 938 | jermar | 38 | static char *error_codes[] = { |
| 39 | "no error", |
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| 40 | "invalid image", |
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| 41 | "address space error", |
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| 42 | "incompatible image", |
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| 43 | "unsupported image type", |
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| 44 | "irrecoverable error" |
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| 45 | }; |
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| 46 | |||
| 47 | static int program_header_entry(elf_header_t *header, elf_ph_entry_t *entry, as_t *as); |
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| 48 | static int load_segment(elf_header_t *header, elf_ph_entry_t *entry, as_t *as); |
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| 49 | |||
| 50 | /** ELF loader |
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| 854 | bondari | 51 | * |
| 52 | * @param header Pointer to ELF header in memory |
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| 53 | * @param as Created and properly mapped address space |
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| 54 | * @return EE_OK on success |
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| 55 | */ |
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| 938 | jermar | 56 | int elf_load(elf_header_t *header, as_t * as) |
| 57 | { |
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| 58 | int i, rc; |
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| 910 | bondari | 59 | |
| 60 | /* Identify ELF */ |
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| 938 | jermar | 61 | if (header->e_ident[EI_MAG0] != ELFMAG0 || header->e_ident[EI_MAG1] != ELFMAG1 || |
| 62 | header->e_ident[EI_MAG2] != ELFMAG2 || header->e_ident[EI_MAG3] != ELFMAG3) { |
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| 910 | bondari | 63 | return EE_INVALID; |
| 64 | } |
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| 65 | |||
| 66 | /* Identify ELF compatibility */ |
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| 938 | jermar | 67 | if (header->e_ident[EI_DATA] != ELF_DATA_ENCODING || header->e_machine != ELF_MACHINE || |
| 68 | header->e_ident[EI_VERSION] != EV_CURRENT || header->e_version != EV_CURRENT || |
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| 69 | header->e_ident[EI_CLASS] != ELF_CLASS) { |
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| 70 | return EE_INCOMPATIBLE; |
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| 71 | } |
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| 72 | |||
| 73 | if (header->e_phentsize != sizeof(elf_ph_entry_t)) |
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| 74 | return EE_INCOMPATIBLE; |
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| 75 | |||
| 76 | /* Check if the object type is supported. */ |
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| 77 | if (header->e_type != ET_EXEC) |
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| 910 | bondari | 78 | return EE_UNSUPPORTED; |
| 938 | jermar | 79 | |
| 80 | /* Walk through all program header entries and process them. */ |
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| 81 | for (i = 0; i < header->e_phnum; i++) { |
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| 82 | rc = program_header_entry(header, &((elf_ph_entry_t *)(((__u8 *) header) + header->e_phoff))[i], as); |
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| 83 | if (rc != EE_OK) |
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| 84 | return rc; |
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| 910 | bondari | 85 | } |
| 938 | jermar | 86 | |
| 87 | return EE_OK; |
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| 88 | } |
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| 89 | |||
| 90 | /** Print error message according to error code. |
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| 91 | * |
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| 92 | * @param rc Return code returned by elf_load(). |
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| 93 | * |
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| 94 | * @return NULL terminated description of error. |
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| 95 | */ |
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| 96 | char *elf_error(int rc) |
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| 97 | { |
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| 98 | ASSERT(rc < sizeof(error_codes)/sizeof(char *)); |
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| 99 | |||
| 100 | return error_codes[rc]; |
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| 101 | } |
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| 102 | |||
| 103 | /** Process program header entry. |
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| 104 | * |
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| 105 | * @param entry Program header entry. |
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| 106 | * @param as Address space into wich the ELF is being loaded. |
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| 107 | * |
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| 108 | * @return EE_OK on success, error code otherwise. |
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| 109 | */ |
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| 110 | static int program_header_entry(elf_header_t *header, elf_ph_entry_t *entry, as_t *as) |
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| 111 | { |
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| 112 | switch (entry->p_type) { |
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| 113 | case PT_NULL: |
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| 114 | case PT_PHDR: |
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| 115 | break; |
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| 116 | case PT_LOAD: |
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| 117 | return load_segment(header, entry, as); |
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| 118 | break; |
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| 119 | case PT_DYNAMIC: |
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| 120 | case PT_INTERP: |
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| 121 | case PT_SHLIB: |
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| 122 | case PT_NOTE: |
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| 123 | case PT_LOPROC: |
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| 124 | case PT_HIPROC: |
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| 125 | default: |
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| 126 | return EE_UNSUPPORTED; |
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| 127 | break; |
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| 128 | } |
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| 129 | return EE_OK; |
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| 130 | } |
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| 131 | |||
| 132 | /** Load segment described by program header entry. |
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| 133 | * |
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| 134 | * @param entry Program header entry describing segment to be loaded. |
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| 135 | * @parma as Address space into wich the ELF is being loaded. |
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| 136 | * |
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| 137 | * @return EE_OK on success, error code otherwise. |
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| 138 | */ |
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| 139 | int load_segment(elf_header_t *header, elf_ph_entry_t *entry, as_t *as) |
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| 140 | { |
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| 141 | as_area_t *a; |
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| 142 | int i, type = 0; |
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| 143 | |||
| 144 | if (entry->p_align > 1) { |
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| 145 | if ((entry->p_offset % entry->p_align) != (entry->p_vaddr % entry->p_align)) { |
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| 146 | return EE_INVALID; |
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| 147 | } |
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| 148 | } |
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| 149 | |||
| 150 | /* |
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| 151 | * Check if the segment doesn't interfere with kernel address space. |
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| 152 | */ |
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| 153 | if (entry->p_vaddr + ALIGN_UP(entry->p_memsz, PAGE_SIZE) >= USER_ADDRESS_SPACE_END) |
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| 154 | return EE_MEMORY; |
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| 910 | bondari | 155 | |
| 938 | jermar | 156 | if (entry->p_flags & PF_X) { |
| 157 | type = AS_AREA_TEXT; |
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| 158 | } else if (entry->p_flags & PF_W) { |
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| 159 | type = AS_AREA_DATA; |
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| 160 | } else { |
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| 161 | return EE_UNSUPPORTED; |
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| 162 | } |
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| 910 | bondari | 163 | |
| 938 | jermar | 164 | a = as_area_create(as, AS_AREA_TEXT, SIZE2FRAMES(entry->p_memsz), entry->p_vaddr); |
| 165 | if (!a) |
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| 166 | return EE_IRRECOVERABLE; |
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| 167 | |||
| 168 | for (i = 0; i < SIZE2FRAMES(entry->p_filesz); i++) { |
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| 169 | as_set_mapping(as, entry->p_vaddr + i*PAGE_SIZE, KA2PA(((__address) header) + entry->p_offset + i*PAGE_SIZE)); |
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| 170 | } |
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| 171 | |||
| 172 | return EE_OK; |
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| 854 | bondari | 173 | } |