Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * arch/s390/kernel/module.c - Kernel module help for s390. |
| 3 | * |
| 4 | * S390 version |
| 5 | * Copyright (C) 2002, 2003 IBM Deutschland Entwicklung GmbH, |
| 6 | * IBM Corporation |
| 7 | * Author(s): Arnd Bergmann (arndb@de.ibm.com) |
| 8 | * Martin Schwidefsky (schwidefsky@de.ibm.com) |
| 9 | * |
| 10 | * based on i386 version |
| 11 | * Copyright (C) 2001 Rusty Russell. |
| 12 | * |
| 13 | * This program is free software; you can redistribute it and/or modify |
| 14 | * it under the terms of the GNU General Public License as published by |
| 15 | * the Free Software Foundation; either version 2 of the License, or |
| 16 | * (at your option) any later version. |
| 17 | * |
| 18 | * This program is distributed in the hope that it will be useful, |
| 19 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 20 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 21 | * GNU General Public License for more details. |
| 22 | * |
| 23 | * You should have received a copy of the GNU General Public License |
| 24 | * along with this program; if not, write to the Free Software |
| 25 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| 26 | */ |
| 27 | #include <linux/module.h> |
| 28 | #include <linux/elf.h> |
| 29 | #include <linux/vmalloc.h> |
| 30 | #include <linux/fs.h> |
| 31 | #include <linux/string.h> |
| 32 | #include <linux/kernel.h> |
| 33 | |
| 34 | #if 0 |
| 35 | #define DEBUGP printk |
| 36 | #else |
| 37 | #define DEBUGP(fmt , ...) |
| 38 | #endif |
| 39 | |
| 40 | #ifndef CONFIG_ARCH_S390X |
| 41 | #define PLT_ENTRY_SIZE 12 |
| 42 | #else /* CONFIG_ARCH_S390X */ |
| 43 | #define PLT_ENTRY_SIZE 20 |
| 44 | #endif /* CONFIG_ARCH_S390X */ |
| 45 | |
| 46 | void *module_alloc(unsigned long size) |
| 47 | { |
| 48 | if (size == 0) |
| 49 | return NULL; |
| 50 | return vmalloc(size); |
| 51 | } |
| 52 | |
| 53 | /* Free memory returned from module_alloc */ |
| 54 | void module_free(struct module *mod, void *module_region) |
| 55 | { |
| 56 | vfree(module_region); |
| 57 | /* FIXME: If module_region == mod->init_region, trim exception |
| 58 | table entries. */ |
| 59 | } |
| 60 | |
| 61 | static inline void |
| 62 | check_rela(Elf_Rela *rela, struct module *me) |
| 63 | { |
| 64 | struct mod_arch_syminfo *info; |
| 65 | |
| 66 | info = me->arch.syminfo + ELF_R_SYM (rela->r_info); |
| 67 | switch (ELF_R_TYPE (rela->r_info)) { |
| 68 | case R_390_GOT12: /* 12 bit GOT offset. */ |
| 69 | case R_390_GOT16: /* 16 bit GOT offset. */ |
| 70 | case R_390_GOT20: /* 20 bit GOT offset. */ |
| 71 | case R_390_GOT32: /* 32 bit GOT offset. */ |
| 72 | case R_390_GOT64: /* 64 bit GOT offset. */ |
| 73 | case R_390_GOTENT: /* 32 bit PC rel. to GOT entry shifted by 1. */ |
| 74 | case R_390_GOTPLT12: /* 12 bit offset to jump slot. */ |
| 75 | case R_390_GOTPLT16: /* 16 bit offset to jump slot. */ |
| 76 | case R_390_GOTPLT20: /* 20 bit offset to jump slot. */ |
| 77 | case R_390_GOTPLT32: /* 32 bit offset to jump slot. */ |
| 78 | case R_390_GOTPLT64: /* 64 bit offset to jump slot. */ |
| 79 | case R_390_GOTPLTENT: /* 32 bit rel. offset to jump slot >> 1. */ |
| 80 | if (info->got_offset == -1UL) { |
| 81 | info->got_offset = me->arch.got_size; |
| 82 | me->arch.got_size += sizeof(void*); |
| 83 | } |
| 84 | break; |
| 85 | case R_390_PLT16DBL: /* 16 bit PC rel. PLT shifted by 1. */ |
| 86 | case R_390_PLT32DBL: /* 32 bit PC rel. PLT shifted by 1. */ |
| 87 | case R_390_PLT32: /* 32 bit PC relative PLT address. */ |
| 88 | case R_390_PLT64: /* 64 bit PC relative PLT address. */ |
| 89 | case R_390_PLTOFF16: /* 16 bit offset from GOT to PLT. */ |
| 90 | case R_390_PLTOFF32: /* 32 bit offset from GOT to PLT. */ |
| 91 | case R_390_PLTOFF64: /* 16 bit offset from GOT to PLT. */ |
| 92 | if (info->plt_offset == -1UL) { |
| 93 | info->plt_offset = me->arch.plt_size; |
| 94 | me->arch.plt_size += PLT_ENTRY_SIZE; |
| 95 | } |
| 96 | break; |
| 97 | case R_390_COPY: |
| 98 | case R_390_GLOB_DAT: |
| 99 | case R_390_JMP_SLOT: |
| 100 | case R_390_RELATIVE: |
| 101 | /* Only needed if we want to support loading of |
| 102 | modules linked with -shared. */ |
| 103 | break; |
| 104 | } |
| 105 | } |
| 106 | |
| 107 | /* |
| 108 | * Account for GOT and PLT relocations. We can't add sections for |
| 109 | * got and plt but we can increase the core module size. |
| 110 | */ |
| 111 | int |
| 112 | module_frob_arch_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs, |
| 113 | char *secstrings, struct module *me) |
| 114 | { |
| 115 | Elf_Shdr *symtab; |
| 116 | Elf_Sym *symbols; |
| 117 | Elf_Rela *rela; |
| 118 | char *strings; |
| 119 | int nrela, i, j; |
| 120 | |
| 121 | /* Find symbol table and string table. */ |
| 122 | symtab = 0; |
| 123 | for (i = 0; i < hdr->e_shnum; i++) |
| 124 | switch (sechdrs[i].sh_type) { |
| 125 | case SHT_SYMTAB: |
| 126 | symtab = sechdrs + i; |
| 127 | break; |
| 128 | } |
| 129 | if (!symtab) { |
| 130 | printk(KERN_ERR "module %s: no symbol table\n", me->name); |
| 131 | return -ENOEXEC; |
| 132 | } |
| 133 | |
| 134 | /* Allocate one syminfo structure per symbol. */ |
| 135 | me->arch.nsyms = symtab->sh_size / sizeof(Elf_Sym); |
| 136 | me->arch.syminfo = vmalloc(me->arch.nsyms * |
| 137 | sizeof(struct mod_arch_syminfo)); |
| 138 | if (!me->arch.syminfo) |
| 139 | return -ENOMEM; |
| 140 | symbols = (void *) hdr + symtab->sh_offset; |
| 141 | strings = (void *) hdr + sechdrs[symtab->sh_link].sh_offset; |
| 142 | for (i = 0; i < me->arch.nsyms; i++) { |
| 143 | if (symbols[i].st_shndx == SHN_UNDEF && |
| 144 | strcmp(strings + symbols[i].st_name, |
| 145 | "_GLOBAL_OFFSET_TABLE_") == 0) |
| 146 | /* "Define" it as absolute. */ |
| 147 | symbols[i].st_shndx = SHN_ABS; |
| 148 | me->arch.syminfo[i].got_offset = -1UL; |
| 149 | me->arch.syminfo[i].plt_offset = -1UL; |
| 150 | me->arch.syminfo[i].got_initialized = 0; |
| 151 | me->arch.syminfo[i].plt_initialized = 0; |
| 152 | } |
| 153 | |
| 154 | /* Search for got/plt relocations. */ |
| 155 | me->arch.got_size = me->arch.plt_size = 0; |
| 156 | for (i = 0; i < hdr->e_shnum; i++) { |
| 157 | if (sechdrs[i].sh_type != SHT_RELA) |
| 158 | continue; |
| 159 | nrela = sechdrs[i].sh_size / sizeof(Elf_Rela); |
| 160 | rela = (void *) hdr + sechdrs[i].sh_offset; |
| 161 | for (j = 0; j < nrela; j++) |
| 162 | check_rela(rela + j, me); |
| 163 | } |
| 164 | |
| 165 | /* Increase core size by size of got & plt and set start |
| 166 | offsets for got and plt. */ |
| 167 | me->core_size = ALIGN(me->core_size, 4); |
| 168 | me->arch.got_offset = me->core_size; |
| 169 | me->core_size += me->arch.got_size; |
| 170 | me->arch.plt_offset = me->core_size; |
| 171 | me->core_size += me->arch.plt_size; |
| 172 | return 0; |
| 173 | } |
| 174 | |
| 175 | int |
| 176 | apply_relocate(Elf_Shdr *sechdrs, const char *strtab, unsigned int symindex, |
| 177 | unsigned int relsec, struct module *me) |
| 178 | { |
| 179 | printk(KERN_ERR "module %s: RELOCATION unsupported\n", |
| 180 | me->name); |
| 181 | return -ENOEXEC; |
| 182 | } |
| 183 | |
| 184 | static inline int |
| 185 | apply_rela(Elf_Rela *rela, Elf_Addr base, Elf_Sym *symtab, |
| 186 | struct module *me) |
| 187 | { |
| 188 | struct mod_arch_syminfo *info; |
| 189 | Elf_Addr loc, val; |
| 190 | int r_type, r_sym; |
| 191 | |
| 192 | /* This is where to make the change */ |
| 193 | loc = base + rela->r_offset; |
| 194 | /* This is the symbol it is referring to. Note that all |
| 195 | undefined symbols have been resolved. */ |
| 196 | r_sym = ELF_R_SYM(rela->r_info); |
| 197 | r_type = ELF_R_TYPE(rela->r_info); |
| 198 | info = me->arch.syminfo + r_sym; |
| 199 | val = symtab[r_sym].st_value; |
| 200 | |
| 201 | switch (r_type) { |
| 202 | case R_390_8: /* Direct 8 bit. */ |
| 203 | case R_390_12: /* Direct 12 bit. */ |
| 204 | case R_390_16: /* Direct 16 bit. */ |
| 205 | case R_390_20: /* Direct 20 bit. */ |
| 206 | case R_390_32: /* Direct 32 bit. */ |
| 207 | case R_390_64: /* Direct 64 bit. */ |
| 208 | val += rela->r_addend; |
| 209 | if (r_type == R_390_8) |
| 210 | *(unsigned char *) loc = val; |
| 211 | else if (r_type == R_390_12) |
| 212 | *(unsigned short *) loc = (val & 0xfff) | |
| 213 | (*(unsigned short *) loc & 0xf000); |
| 214 | else if (r_type == R_390_16) |
| 215 | *(unsigned short *) loc = val; |
| 216 | else if (r_type == R_390_20) |
| 217 | *(unsigned int *) loc = |
| 218 | (*(unsigned int *) loc & 0xf00000ff) | |
| 219 | (val & 0xfff) << 16 | (val & 0xff000) >> 4; |
| 220 | else if (r_type == R_390_32) |
| 221 | *(unsigned int *) loc = val; |
| 222 | else if (r_type == R_390_64) |
| 223 | *(unsigned long *) loc = val; |
| 224 | break; |
| 225 | case R_390_PC16: /* PC relative 16 bit. */ |
| 226 | case R_390_PC16DBL: /* PC relative 16 bit shifted by 1. */ |
| 227 | case R_390_PC32DBL: /* PC relative 32 bit shifted by 1. */ |
| 228 | case R_390_PC32: /* PC relative 32 bit. */ |
| 229 | case R_390_PC64: /* PC relative 64 bit. */ |
| 230 | val += rela->r_addend - loc; |
| 231 | if (r_type == R_390_PC16) |
| 232 | *(unsigned short *) loc = val; |
| 233 | else if (r_type == R_390_PC16DBL) |
| 234 | *(unsigned short *) loc = val >> 1; |
| 235 | else if (r_type == R_390_PC32DBL) |
| 236 | *(unsigned int *) loc = val >> 1; |
| 237 | else if (r_type == R_390_PC32) |
| 238 | *(unsigned int *) loc = val; |
| 239 | else if (r_type == R_390_PC64) |
| 240 | *(unsigned long *) loc = val; |
| 241 | break; |
| 242 | case R_390_GOT12: /* 12 bit GOT offset. */ |
| 243 | case R_390_GOT16: /* 16 bit GOT offset. */ |
| 244 | case R_390_GOT20: /* 20 bit GOT offset. */ |
| 245 | case R_390_GOT32: /* 32 bit GOT offset. */ |
| 246 | case R_390_GOT64: /* 64 bit GOT offset. */ |
| 247 | case R_390_GOTENT: /* 32 bit PC rel. to GOT entry shifted by 1. */ |
| 248 | case R_390_GOTPLT12: /* 12 bit offset to jump slot. */ |
| 249 | case R_390_GOTPLT20: /* 20 bit offset to jump slot. */ |
| 250 | case R_390_GOTPLT16: /* 16 bit offset to jump slot. */ |
| 251 | case R_390_GOTPLT32: /* 32 bit offset to jump slot. */ |
| 252 | case R_390_GOTPLT64: /* 64 bit offset to jump slot. */ |
| 253 | case R_390_GOTPLTENT: /* 32 bit rel. offset to jump slot >> 1. */ |
| 254 | if (info->got_initialized == 0) { |
| 255 | Elf_Addr *gotent; |
| 256 | |
| 257 | gotent = me->module_core + me->arch.got_offset + |
| 258 | info->got_offset; |
| 259 | *gotent = val; |
| 260 | info->got_initialized = 1; |
| 261 | } |
| 262 | val = info->got_offset + rela->r_addend; |
| 263 | if (r_type == R_390_GOT12 || |
| 264 | r_type == R_390_GOTPLT12) |
| 265 | *(unsigned short *) loc = (val & 0xfff) | |
| 266 | (*(unsigned short *) loc & 0xf000); |
| 267 | else if (r_type == R_390_GOT16 || |
| 268 | r_type == R_390_GOTPLT16) |
| 269 | *(unsigned short *) loc = val; |
| 270 | else if (r_type == R_390_GOT20 || |
| 271 | r_type == R_390_GOTPLT20) |
| 272 | *(unsigned int *) loc = |
| 273 | (*(unsigned int *) loc & 0xf00000ff) | |
| 274 | (val & 0xfff) << 16 | (val & 0xff000) >> 4; |
| 275 | else if (r_type == R_390_GOT32 || |
| 276 | r_type == R_390_GOTPLT32) |
| 277 | *(unsigned int *) loc = val; |
| 278 | else if (r_type == R_390_GOTENT || |
| 279 | r_type == R_390_GOTPLTENT) |
| 280 | *(unsigned int *) loc = |
| 281 | (val + (Elf_Addr) me->module_core - loc) >> 1; |
| 282 | else if (r_type == R_390_GOT64 || |
| 283 | r_type == R_390_GOTPLT64) |
| 284 | *(unsigned long *) loc = val; |
| 285 | break; |
| 286 | case R_390_PLT16DBL: /* 16 bit PC rel. PLT shifted by 1. */ |
| 287 | case R_390_PLT32DBL: /* 32 bit PC rel. PLT shifted by 1. */ |
| 288 | case R_390_PLT32: /* 32 bit PC relative PLT address. */ |
| 289 | case R_390_PLT64: /* 64 bit PC relative PLT address. */ |
| 290 | case R_390_PLTOFF16: /* 16 bit offset from GOT to PLT. */ |
| 291 | case R_390_PLTOFF32: /* 32 bit offset from GOT to PLT. */ |
| 292 | case R_390_PLTOFF64: /* 16 bit offset from GOT to PLT. */ |
| 293 | if (info->plt_initialized == 0) { |
| 294 | unsigned int *ip; |
| 295 | ip = me->module_core + me->arch.plt_offset + |
| 296 | info->plt_offset; |
| 297 | #ifndef CONFIG_ARCH_S390X |
| 298 | ip[0] = 0x0d105810; /* basr 1,0; l 1,6(1); br 1 */ |
| 299 | ip[1] = 0x100607f1; |
| 300 | ip[2] = val; |
| 301 | #else /* CONFIG_ARCH_S390X */ |
| 302 | ip[0] = 0x0d10e310; /* basr 1,0; lg 1,10(1); br 1 */ |
| 303 | ip[1] = 0x100a0004; |
| 304 | ip[2] = 0x07f10000; |
| 305 | ip[3] = (unsigned int) (val >> 32); |
| 306 | ip[4] = (unsigned int) val; |
| 307 | #endif /* CONFIG_ARCH_S390X */ |
| 308 | info->plt_initialized = 1; |
| 309 | } |
| 310 | if (r_type == R_390_PLTOFF16 || |
| 311 | r_type == R_390_PLTOFF32 |
| 312 | || r_type == R_390_PLTOFF64 |
| 313 | ) |
| 314 | val = me->arch.plt_offset - me->arch.got_offset + |
| 315 | info->plt_offset + rela->r_addend; |
| 316 | else |
| 317 | val = (Elf_Addr) me->module_core + |
| 318 | me->arch.plt_offset + info->plt_offset + |
| 319 | rela->r_addend - loc; |
| 320 | if (r_type == R_390_PLT16DBL) |
| 321 | *(unsigned short *) loc = val >> 1; |
| 322 | else if (r_type == R_390_PLTOFF16) |
| 323 | *(unsigned short *) loc = val; |
| 324 | else if (r_type == R_390_PLT32DBL) |
| 325 | *(unsigned int *) loc = val >> 1; |
| 326 | else if (r_type == R_390_PLT32 || |
| 327 | r_type == R_390_PLTOFF32) |
| 328 | *(unsigned int *) loc = val; |
| 329 | else if (r_type == R_390_PLT64 || |
| 330 | r_type == R_390_PLTOFF64) |
| 331 | *(unsigned long *) loc = val; |
| 332 | break; |
| 333 | case R_390_GOTOFF16: /* 16 bit offset to GOT. */ |
| 334 | case R_390_GOTOFF32: /* 32 bit offset to GOT. */ |
| 335 | case R_390_GOTOFF64: /* 64 bit offset to GOT. */ |
| 336 | val = val + rela->r_addend - |
| 337 | ((Elf_Addr) me->module_core + me->arch.got_offset); |
| 338 | if (r_type == R_390_GOTOFF16) |
| 339 | *(unsigned short *) loc = val; |
| 340 | else if (r_type == R_390_GOTOFF32) |
| 341 | *(unsigned int *) loc = val; |
| 342 | else if (r_type == R_390_GOTOFF64) |
| 343 | *(unsigned long *) loc = val; |
| 344 | break; |
| 345 | case R_390_GOTPC: /* 32 bit PC relative offset to GOT. */ |
| 346 | case R_390_GOTPCDBL: /* 32 bit PC rel. off. to GOT shifted by 1. */ |
| 347 | val = (Elf_Addr) me->module_core + me->arch.got_offset + |
| 348 | rela->r_addend - loc; |
| 349 | if (r_type == R_390_GOTPC) |
| 350 | *(unsigned int *) loc = val; |
| 351 | else if (r_type == R_390_GOTPCDBL) |
| 352 | *(unsigned int *) loc = val >> 1; |
| 353 | break; |
| 354 | case R_390_COPY: |
| 355 | case R_390_GLOB_DAT: /* Create GOT entry. */ |
| 356 | case R_390_JMP_SLOT: /* Create PLT entry. */ |
| 357 | case R_390_RELATIVE: /* Adjust by program base. */ |
| 358 | /* Only needed if we want to support loading of |
| 359 | modules linked with -shared. */ |
| 360 | break; |
| 361 | default: |
| 362 | printk(KERN_ERR "module %s: Unknown relocation: %u\n", |
| 363 | me->name, r_type); |
| 364 | return -ENOEXEC; |
| 365 | } |
| 366 | return 0; |
| 367 | } |
| 368 | |
| 369 | int |
| 370 | apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab, |
| 371 | unsigned int symindex, unsigned int relsec, |
| 372 | struct module *me) |
| 373 | { |
| 374 | Elf_Addr base; |
| 375 | Elf_Sym *symtab; |
| 376 | Elf_Rela *rela; |
| 377 | unsigned long i, n; |
| 378 | int rc; |
| 379 | |
| 380 | DEBUGP("Applying relocate section %u to %u\n", |
| 381 | relsec, sechdrs[relsec].sh_info); |
| 382 | base = sechdrs[sechdrs[relsec].sh_info].sh_addr; |
| 383 | symtab = (Elf_Sym *) sechdrs[symindex].sh_addr; |
| 384 | rela = (Elf_Rela *) sechdrs[relsec].sh_addr; |
| 385 | n = sechdrs[relsec].sh_size / sizeof(Elf_Rela); |
| 386 | |
| 387 | for (i = 0; i < n; i++, rela++) { |
| 388 | rc = apply_rela(rela, base, symtab, me); |
| 389 | if (rc) |
| 390 | return rc; |
| 391 | } |
| 392 | return 0; |
| 393 | } |
| 394 | |
| 395 | int module_finalize(const Elf_Ehdr *hdr, |
| 396 | const Elf_Shdr *sechdrs, |
| 397 | struct module *me) |
| 398 | { |
| 399 | vfree(me->arch.syminfo); |
| 400 | return 0; |
| 401 | } |
| 402 | |
| 403 | void module_arch_cleanup(struct module *mod) |
| 404 | { |
| 405 | } |