Haavard Skinnemoen | 5f97f7f | 2006-09-25 23:32:13 -0700 | [diff] [blame] | 1 | /* |
| 2 | * AVR32-specific kernel module loader |
| 3 | * |
| 4 | * Copyright (C) 2005-2006 Atmel Corporation |
| 5 | * |
| 6 | * GOT initialization parts are based on the s390 version |
| 7 | * Copyright (C) 2002, 2003 IBM Deutschland Entwicklung GmbH, |
| 8 | * IBM Corporation |
| 9 | * |
| 10 | * This program is free software; you can redistribute it and/or modify |
| 11 | * it under the terms of the GNU General Public License version 2 as |
| 12 | * published by the Free Software Foundation. |
| 13 | */ |
| 14 | |
Haavard Skinnemoen | 623b035 | 2007-03-13 17:59:11 +0100 | [diff] [blame] | 15 | #include <linux/bug.h> |
Haavard Skinnemoen | 5f97f7f | 2006-09-25 23:32:13 -0700 | [diff] [blame] | 16 | #include <linux/elf.h> |
Haavard Skinnemoen | 623b035 | 2007-03-13 17:59:11 +0100 | [diff] [blame] | 17 | #include <linux/kernel.h> |
| 18 | #include <linux/module.h> |
| 19 | #include <linux/moduleloader.h> |
Haavard Skinnemoen | 5f97f7f | 2006-09-25 23:32:13 -0700 | [diff] [blame] | 20 | #include <linux/vmalloc.h> |
| 21 | |
| 22 | void *module_alloc(unsigned long size) |
| 23 | { |
| 24 | if (size == 0) |
| 25 | return NULL; |
| 26 | return vmalloc(size); |
| 27 | } |
| 28 | |
| 29 | void module_free(struct module *mod, void *module_region) |
| 30 | { |
| 31 | vfree(mod->arch.syminfo); |
| 32 | mod->arch.syminfo = NULL; |
| 33 | |
| 34 | vfree(module_region); |
| 35 | /* FIXME: if module_region == mod->init_region, trim exception |
| 36 | * table entries. */ |
| 37 | } |
| 38 | |
| 39 | static inline int check_rela(Elf32_Rela *rela, struct module *module, |
| 40 | char *strings, Elf32_Sym *symbols) |
| 41 | { |
| 42 | struct mod_arch_syminfo *info; |
| 43 | |
| 44 | info = module->arch.syminfo + ELF32_R_SYM(rela->r_info); |
| 45 | switch (ELF32_R_TYPE(rela->r_info)) { |
| 46 | case R_AVR32_GOT32: |
| 47 | case R_AVR32_GOT16: |
| 48 | case R_AVR32_GOT8: |
| 49 | case R_AVR32_GOT21S: |
| 50 | case R_AVR32_GOT18SW: /* mcall */ |
| 51 | case R_AVR32_GOT16S: /* ld.w */ |
| 52 | if (rela->r_addend != 0) { |
| 53 | printk(KERN_ERR |
| 54 | "GOT relocation against %s at offset %u with addend\n", |
| 55 | strings + symbols[ELF32_R_SYM(rela->r_info)].st_name, |
| 56 | rela->r_offset); |
| 57 | return -ENOEXEC; |
| 58 | } |
| 59 | if (info->got_offset == -1UL) { |
| 60 | info->got_offset = module->arch.got_size; |
| 61 | module->arch.got_size += sizeof(void *); |
| 62 | } |
| 63 | pr_debug("GOT[%3lu] %s\n", info->got_offset, |
| 64 | strings + symbols[ELF32_R_SYM(rela->r_info)].st_name); |
| 65 | break; |
| 66 | } |
| 67 | |
| 68 | return 0; |
| 69 | } |
| 70 | |
| 71 | int module_frob_arch_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs, |
| 72 | char *secstrings, struct module *module) |
| 73 | { |
| 74 | Elf32_Shdr *symtab; |
| 75 | Elf32_Sym *symbols; |
| 76 | Elf32_Rela *rela; |
| 77 | char *strings; |
| 78 | int nrela, i, j; |
| 79 | int ret; |
| 80 | |
| 81 | /* Find the symbol table */ |
| 82 | symtab = NULL; |
| 83 | for (i = 0; i < hdr->e_shnum; i++) |
| 84 | switch (sechdrs[i].sh_type) { |
| 85 | case SHT_SYMTAB: |
| 86 | symtab = &sechdrs[i]; |
| 87 | break; |
| 88 | } |
| 89 | if (!symtab) { |
| 90 | printk(KERN_ERR "module %s: no symbol table\n", module->name); |
| 91 | return -ENOEXEC; |
| 92 | } |
| 93 | |
| 94 | /* Allocate room for one syminfo structure per symbol. */ |
| 95 | module->arch.nsyms = symtab->sh_size / sizeof(Elf_Sym); |
| 96 | module->arch.syminfo = vmalloc(module->arch.nsyms |
| 97 | * sizeof(struct mod_arch_syminfo)); |
| 98 | if (!module->arch.syminfo) |
| 99 | return -ENOMEM; |
| 100 | |
| 101 | symbols = (void *)hdr + symtab->sh_offset; |
| 102 | strings = (void *)hdr + sechdrs[symtab->sh_link].sh_offset; |
| 103 | for (i = 0; i < module->arch.nsyms; i++) { |
| 104 | if (symbols[i].st_shndx == SHN_UNDEF && |
| 105 | strcmp(strings + symbols[i].st_name, |
| 106 | "_GLOBAL_OFFSET_TABLE_") == 0) |
| 107 | /* "Define" it as absolute. */ |
| 108 | symbols[i].st_shndx = SHN_ABS; |
| 109 | module->arch.syminfo[i].got_offset = -1UL; |
| 110 | module->arch.syminfo[i].got_initialized = 0; |
| 111 | } |
| 112 | |
| 113 | /* Allocate GOT entries for symbols that need it. */ |
| 114 | module->arch.got_size = 0; |
| 115 | for (i = 0; i < hdr->e_shnum; i++) { |
| 116 | if (sechdrs[i].sh_type != SHT_RELA) |
| 117 | continue; |
| 118 | nrela = sechdrs[i].sh_size / sizeof(Elf32_Rela); |
| 119 | rela = (void *)hdr + sechdrs[i].sh_offset; |
| 120 | for (j = 0; j < nrela; j++) { |
| 121 | ret = check_rela(rela + j, module, |
| 122 | strings, symbols); |
| 123 | if (ret) |
| 124 | goto out_free_syminfo; |
| 125 | } |
| 126 | } |
| 127 | |
| 128 | /* |
| 129 | * Increase core size to make room for GOT and set start |
| 130 | * offset for GOT. |
| 131 | */ |
| 132 | module->core_size = ALIGN(module->core_size, 4); |
| 133 | module->arch.got_offset = module->core_size; |
| 134 | module->core_size += module->arch.got_size; |
| 135 | |
| 136 | return 0; |
| 137 | |
| 138 | out_free_syminfo: |
| 139 | vfree(module->arch.syminfo); |
| 140 | module->arch.syminfo = NULL; |
| 141 | |
| 142 | return ret; |
| 143 | } |
| 144 | |
| 145 | static inline int reloc_overflow(struct module *module, const char *reloc_name, |
| 146 | Elf32_Addr relocation) |
| 147 | { |
| 148 | printk(KERN_ERR "module %s: Value %lx does not fit relocation %s\n", |
| 149 | module->name, (unsigned long)relocation, reloc_name); |
| 150 | return -ENOEXEC; |
| 151 | } |
| 152 | |
| 153 | #define get_u16(loc) (*((uint16_t *)loc)) |
| 154 | #define put_u16(loc, val) (*((uint16_t *)loc) = (val)) |
| 155 | |
| 156 | int apply_relocate_add(Elf32_Shdr *sechdrs, const char *strtab, |
| 157 | unsigned int symindex, unsigned int relindex, |
| 158 | struct module *module) |
| 159 | { |
| 160 | Elf32_Shdr *symsec = sechdrs + symindex; |
| 161 | Elf32_Shdr *relsec = sechdrs + relindex; |
| 162 | Elf32_Shdr *dstsec = sechdrs + relsec->sh_info; |
| 163 | Elf32_Rela *rel = (void *)relsec->sh_addr; |
| 164 | unsigned int i; |
| 165 | int ret = 0; |
| 166 | |
| 167 | for (i = 0; i < relsec->sh_size / sizeof(Elf32_Rela); i++, rel++) { |
| 168 | struct mod_arch_syminfo *info; |
| 169 | Elf32_Sym *sym; |
| 170 | Elf32_Addr relocation; |
| 171 | uint32_t *location; |
| 172 | uint32_t value; |
| 173 | |
| 174 | location = (void *)dstsec->sh_addr + rel->r_offset; |
| 175 | sym = (Elf32_Sym *)symsec->sh_addr + ELF32_R_SYM(rel->r_info); |
| 176 | relocation = sym->st_value + rel->r_addend; |
| 177 | |
| 178 | info = module->arch.syminfo + ELF32_R_SYM(rel->r_info); |
| 179 | |
| 180 | /* Initialize GOT entry if necessary */ |
| 181 | switch (ELF32_R_TYPE(rel->r_info)) { |
| 182 | case R_AVR32_GOT32: |
| 183 | case R_AVR32_GOT16: |
| 184 | case R_AVR32_GOT8: |
| 185 | case R_AVR32_GOT21S: |
| 186 | case R_AVR32_GOT18SW: |
| 187 | case R_AVR32_GOT16S: |
| 188 | if (!info->got_initialized) { |
| 189 | Elf32_Addr *gotent; |
| 190 | |
| 191 | gotent = (module->module_core |
| 192 | + module->arch.got_offset |
| 193 | + info->got_offset); |
| 194 | *gotent = relocation; |
| 195 | info->got_initialized = 1; |
| 196 | } |
| 197 | |
| 198 | relocation = info->got_offset; |
| 199 | break; |
| 200 | } |
| 201 | |
| 202 | switch (ELF32_R_TYPE(rel->r_info)) { |
| 203 | case R_AVR32_32: |
| 204 | case R_AVR32_32_CPENT: |
| 205 | *location = relocation; |
| 206 | break; |
| 207 | case R_AVR32_22H_PCREL: |
| 208 | relocation -= (Elf32_Addr)location; |
| 209 | if ((relocation & 0xffe00001) != 0 |
| 210 | && (relocation & 0xffc00001) != 0xffc00000) |
| 211 | return reloc_overflow(module, |
| 212 | "R_AVR32_22H_PCREL", |
| 213 | relocation); |
| 214 | relocation >>= 1; |
| 215 | |
| 216 | value = *location; |
| 217 | value = ((value & 0xe1ef0000) |
| 218 | | (relocation & 0xffff) |
| 219 | | ((relocation & 0x10000) << 4) |
| 220 | | ((relocation & 0x1e0000) << 8)); |
| 221 | *location = value; |
| 222 | break; |
| 223 | case R_AVR32_11H_PCREL: |
| 224 | relocation -= (Elf32_Addr)location; |
| 225 | if ((relocation & 0xfffffc01) != 0 |
| 226 | && (relocation & 0xfffff801) != 0xfffff800) |
| 227 | return reloc_overflow(module, |
| 228 | "R_AVR32_11H_PCREL", |
| 229 | relocation); |
| 230 | value = get_u16(location); |
| 231 | value = ((value & 0xf00c) |
| 232 | | ((relocation & 0x1fe) << 3) |
| 233 | | ((relocation & 0x600) >> 9)); |
| 234 | put_u16(location, value); |
| 235 | break; |
| 236 | case R_AVR32_9H_PCREL: |
| 237 | relocation -= (Elf32_Addr)location; |
| 238 | if ((relocation & 0xffffff01) != 0 |
| 239 | && (relocation & 0xfffffe01) != 0xfffffe00) |
| 240 | return reloc_overflow(module, |
| 241 | "R_AVR32_9H_PCREL", |
| 242 | relocation); |
| 243 | value = get_u16(location); |
| 244 | value = ((value & 0xf00f) |
| 245 | | ((relocation & 0x1fe) << 3)); |
| 246 | put_u16(location, value); |
| 247 | break; |
| 248 | case R_AVR32_9UW_PCREL: |
| 249 | relocation -= ((Elf32_Addr)location) & 0xfffffffc; |
| 250 | if ((relocation & 0xfffffc03) != 0) |
| 251 | return reloc_overflow(module, |
| 252 | "R_AVR32_9UW_PCREL", |
| 253 | relocation); |
| 254 | value = get_u16(location); |
| 255 | value = ((value & 0xf80f) |
| 256 | | ((relocation & 0x1fc) << 2)); |
| 257 | put_u16(location, value); |
| 258 | break; |
| 259 | case R_AVR32_GOTPC: |
| 260 | /* |
| 261 | * R6 = PC - (PC - GOT) |
| 262 | * |
| 263 | * At this point, relocation contains the |
| 264 | * value of PC. Just subtract the value of |
| 265 | * GOT, and we're done. |
| 266 | */ |
Haavard Skinnemoen | 6ea850b | 2006-10-24 10:12:40 +0200 | [diff] [blame] | 267 | pr_debug("GOTPC: PC=0x%x, got_offset=0x%lx, core=0x%p\n", |
Haavard Skinnemoen | 5f97f7f | 2006-09-25 23:32:13 -0700 | [diff] [blame] | 268 | relocation, module->arch.got_offset, |
| 269 | module->module_core); |
| 270 | relocation -= ((unsigned long)module->module_core |
| 271 | + module->arch.got_offset); |
| 272 | *location = relocation; |
| 273 | break; |
| 274 | case R_AVR32_GOT18SW: |
| 275 | if ((relocation & 0xfffe0003) != 0 |
| 276 | && (relocation & 0xfffc0003) != 0xffff0000) |
| 277 | return reloc_overflow(module, "R_AVR32_GOT18SW", |
| 278 | relocation); |
| 279 | relocation >>= 2; |
| 280 | /* fall through */ |
| 281 | case R_AVR32_GOT16S: |
| 282 | if ((relocation & 0xffff8000) != 0 |
| 283 | && (relocation & 0xffff0000) != 0xffff0000) |
| 284 | return reloc_overflow(module, "R_AVR32_GOT16S", |
| 285 | relocation); |
Haavard Skinnemoen | 6ea850b | 2006-10-24 10:12:40 +0200 | [diff] [blame] | 286 | pr_debug("GOT reloc @ 0x%x -> %u\n", |
Haavard Skinnemoen | 5f97f7f | 2006-09-25 23:32:13 -0700 | [diff] [blame] | 287 | rel->r_offset, relocation); |
| 288 | value = *location; |
| 289 | value = ((value & 0xffff0000) |
| 290 | | (relocation & 0xffff)); |
| 291 | *location = value; |
| 292 | break; |
| 293 | |
| 294 | default: |
| 295 | printk(KERN_ERR "module %s: Unknown relocation: %u\n", |
| 296 | module->name, ELF32_R_TYPE(rel->r_info)); |
| 297 | return -ENOEXEC; |
| 298 | } |
| 299 | } |
| 300 | |
| 301 | return ret; |
| 302 | } |
| 303 | |
| 304 | int apply_relocate(Elf32_Shdr *sechdrs, const char *strtab, |
| 305 | unsigned int symindex, unsigned int relindex, |
| 306 | struct module *module) |
| 307 | { |
| 308 | printk(KERN_ERR "module %s: REL relocations are not supported\n", |
| 309 | module->name); |
| 310 | return -ENOEXEC; |
| 311 | } |
| 312 | |
| 313 | int module_finalize(const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs, |
| 314 | struct module *module) |
| 315 | { |
| 316 | vfree(module->arch.syminfo); |
| 317 | module->arch.syminfo = NULL; |
| 318 | |
Haavard Skinnemoen | 623b035 | 2007-03-13 17:59:11 +0100 | [diff] [blame] | 319 | return module_bug_finalize(hdr, sechdrs, module); |
Haavard Skinnemoen | 5f97f7f | 2006-09-25 23:32:13 -0700 | [diff] [blame] | 320 | } |
| 321 | |
| 322 | void module_arch_cleanup(struct module *module) |
| 323 | { |
Haavard Skinnemoen | 623b035 | 2007-03-13 17:59:11 +0100 | [diff] [blame] | 324 | module_bug_cleanup(module); |
Haavard Skinnemoen | 5f97f7f | 2006-09-25 23:32:13 -0700 | [diff] [blame] | 325 | } |