1 /* Kernel dynamically loadable module help for PARISC. 2 * 3 * The best reference for this stuff is probably the Processor- 4 * Specific ELF Supplement for PA-RISC: 5 * http://ftp.parisc-linux.org/docs/arch/elf-pa-hp.pdf 6 * 7 * Linux/PA-RISC Project (http://www.parisc-linux.org/) 8 * Copyright (C) 2003 Randolph Chung <tausq at debian . org> 9 * Copyright (C) 2008 Helge Deller <deller@gmx.de> 10 * 11 * 12 * This program is free software; you can redistribute it and/or modify 13 * it under the terms of the GNU General Public License as published by 14 * the Free Software Foundation; either version 2 of the License, or 15 * (at your option) any later version. 16 * 17 * This program is distributed in the hope that it will be useful, 18 * but WITHOUT ANY WARRANTY; without even the implied warranty of 19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 20 * GNU General Public License for more details. 21 * 22 * You should have received a copy of the GNU General Public License 23 * along with this program; if not, write to the Free Software 24 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 25 * 26 * 27 * Notes: 28 * - PLT stub handling 29 * On 32bit (and sometimes 64bit) and with big kernel modules like xfs or 30 * ipv6 the relocation types R_PARISC_PCREL17F and R_PARISC_PCREL22F may 31 * fail to reach their PLT stub if we only create one big stub array for 32 * all sections at the beginning of the core or init section. 33 * Instead we now insert individual PLT stub entries directly in front of 34 * of the code sections where the stubs are actually called. 35 * This reduces the distance between the PCREL location and the stub entry 36 * so that the relocations can be fulfilled. 37 * While calculating the final layout of the kernel module in memory, the 38 * kernel module loader calls arch_mod_section_prepend() to request the 39 * to be reserved amount of memory in front of each individual section. 40 * 41 * - SEGREL32 handling 42 * We are not doing SEGREL32 handling correctly. According to the ABI, we 43 * should do a value offset, like this: 44 * if (in_init(me, (void *)val)) 45 * val -= (uint32_t)me->module_init; 46 * else 47 * val -= (uint32_t)me->module_core; 48 * However, SEGREL32 is used only for PARISC unwind entries, and we want 49 * those entries to have an absolute address, and not just an offset. 50 * 51 * The unwind table mechanism has the ability to specify an offset for 52 * the unwind table; however, because we split off the init functions into 53 * a different piece of memory, it is not possible to do this using a 54 * single offset. Instead, we use the above hack for now. 55 */ 56 57 #include <linux/moduleloader.h> 58 #include <linux/elf.h> 59 #include <linux/vmalloc.h> 60 #include <linux/fs.h> 61 #include <linux/string.h> 62 #include <linux/kernel.h> 63 #include <linux/bug.h> 64 65 #include <asm/unwind.h> 66 67 #if 0 68 #define DEBUGP printk 69 #else 70 #define DEBUGP(fmt...) 71 #endif 72 73 #define RELOC_REACHABLE(val, bits) \ 74 (( ( !((val) & (1<<((bits)-1))) && ((val)>>(bits)) != 0 ) || \ 75 ( ((val) & (1<<((bits)-1))) && ((val)>>(bits)) != (((__typeof__(val))(~0))>>((bits)+2)))) ? \ 76 0 : 1) 77 78 #define CHECK_RELOC(val, bits) \ 79 if (!RELOC_REACHABLE(val, bits)) { \ 80 printk(KERN_ERR "module %s relocation of symbol %s is out of range (0x%lx in %d bits)\n", \ 81 me->name, strtab + sym->st_name, (unsigned long)val, bits); \ 82 return -ENOEXEC; \ 83 } 84 85 /* Maximum number of GOT entries. We use a long displacement ldd from 86 * the bottom of the table, which has a maximum signed displacement of 87 * 0x3fff; however, since we're only going forward, this becomes 88 * 0x1fff, and thus, since each GOT entry is 8 bytes long we can have 89 * at most 1023 entries. 90 * To overcome this 14bit displacement with some kernel modules, we'll 91 * use instead the unusal 16bit displacement method (see reassemble_16a) 92 * which gives us a maximum positive displacement of 0x7fff, and as such 93 * allows us to allocate up to 4095 GOT entries. */ 94 #define MAX_GOTS 4095 95 96 /* three functions to determine where in the module core 97 * or init pieces the location is */ 98 static inline int in_init(struct module *me, void *loc) 99 { 100 return (loc >= me->module_init && 101 loc <= (me->module_init + me->init_size)); 102 } 103 104 static inline int in_core(struct module *me, void *loc) 105 { 106 return (loc >= me->module_core && 107 loc <= (me->module_core + me->core_size)); 108 } 109 110 static inline int in_local(struct module *me, void *loc) 111 { 112 return in_init(me, loc) || in_core(me, loc); 113 } 114 115 #ifndef CONFIG_64BIT 116 struct got_entry { 117 Elf32_Addr addr; 118 }; 119 120 struct stub_entry { 121 Elf32_Word insns[2]; /* each stub entry has two insns */ 122 }; 123 #else 124 struct got_entry { 125 Elf64_Addr addr; 126 }; 127 128 struct stub_entry { 129 Elf64_Word insns[4]; /* each stub entry has four insns */ 130 }; 131 #endif 132 133 /* Field selection types defined by hppa */ 134 #define rnd(x) (((x)+0x1000)&~0x1fff) 135 /* fsel: full 32 bits */ 136 #define fsel(v,a) ((v)+(a)) 137 /* lsel: select left 21 bits */ 138 #define lsel(v,a) (((v)+(a))>>11) 139 /* rsel: select right 11 bits */ 140 #define rsel(v,a) (((v)+(a))&0x7ff) 141 /* lrsel with rounding of addend to nearest 8k */ 142 #define lrsel(v,a) (((v)+rnd(a))>>11) 143 /* rrsel with rounding of addend to nearest 8k */ 144 #define rrsel(v,a) ((((v)+rnd(a))&0x7ff)+((a)-rnd(a))) 145 146 #define mask(x,sz) ((x) & ~((1<<(sz))-1)) 147 148 149 /* The reassemble_* functions prepare an immediate value for 150 insertion into an opcode. pa-risc uses all sorts of weird bitfields 151 in the instruction to hold the value. */ 152 static inline int sign_unext(int x, int len) 153 { 154 int len_ones; 155 156 len_ones = (1 << len) - 1; 157 return x & len_ones; 158 } 159 160 static inline int low_sign_unext(int x, int len) 161 { 162 int sign, temp; 163 164 sign = (x >> (len-1)) & 1; 165 temp = sign_unext(x, len-1); 166 return (temp << 1) | sign; 167 } 168 169 static inline int reassemble_14(int as14) 170 { 171 return (((as14 & 0x1fff) << 1) | 172 ((as14 & 0x2000) >> 13)); 173 } 174 175 static inline int reassemble_16a(int as16) 176 { 177 int s, t; 178 179 /* Unusual 16-bit encoding, for wide mode only. */ 180 t = (as16 << 1) & 0xffff; 181 s = (as16 & 0x8000); 182 return (t ^ s ^ (s >> 1)) | (s >> 15); 183 } 184 185 186 static inline int reassemble_17(int as17) 187 { 188 return (((as17 & 0x10000) >> 16) | 189 ((as17 & 0x0f800) << 5) | 190 ((as17 & 0x00400) >> 8) | 191 ((as17 & 0x003ff) << 3)); 192 } 193 194 static inline int reassemble_21(int as21) 195 { 196 return (((as21 & 0x100000) >> 20) | 197 ((as21 & 0x0ffe00) >> 8) | 198 ((as21 & 0x000180) << 7) | 199 ((as21 & 0x00007c) << 14) | 200 ((as21 & 0x000003) << 12)); 201 } 202 203 static inline int reassemble_22(int as22) 204 { 205 return (((as22 & 0x200000) >> 21) | 206 ((as22 & 0x1f0000) << 5) | 207 ((as22 & 0x00f800) << 5) | 208 ((as22 & 0x000400) >> 8) | 209 ((as22 & 0x0003ff) << 3)); 210 } 211 212 void *module_alloc(unsigned long size) 213 { 214 if (size == 0) 215 return NULL; 216 return vmalloc(size); 217 } 218 219 #ifndef CONFIG_64BIT 220 static inline unsigned long count_gots(const Elf_Rela *rela, unsigned long n) 221 { 222 return 0; 223 } 224 225 static inline unsigned long count_fdescs(const Elf_Rela *rela, unsigned long n) 226 { 227 return 0; 228 } 229 230 static inline unsigned long count_stubs(const Elf_Rela *rela, unsigned long n) 231 { 232 unsigned long cnt = 0; 233 234 for (; n > 0; n--, rela++) 235 { 236 switch (ELF32_R_TYPE(rela->r_info)) { 237 case R_PARISC_PCREL17F: 238 case R_PARISC_PCREL22F: 239 cnt++; 240 } 241 } 242 243 return cnt; 244 } 245 #else 246 static inline unsigned long count_gots(const Elf_Rela *rela, unsigned long n) 247 { 248 unsigned long cnt = 0; 249 250 for (; n > 0; n--, rela++) 251 { 252 switch (ELF64_R_TYPE(rela->r_info)) { 253 case R_PARISC_LTOFF21L: 254 case R_PARISC_LTOFF14R: 255 case R_PARISC_PCREL22F: 256 cnt++; 257 } 258 } 259 260 return cnt; 261 } 262 263 static inline unsigned long count_fdescs(const Elf_Rela *rela, unsigned long n) 264 { 265 unsigned long cnt = 0; 266 267 for (; n > 0; n--, rela++) 268 { 269 switch (ELF64_R_TYPE(rela->r_info)) { 270 case R_PARISC_FPTR64: 271 cnt++; 272 } 273 } 274 275 return cnt; 276 } 277 278 static inline unsigned long count_stubs(const Elf_Rela *rela, unsigned long n) 279 { 280 unsigned long cnt = 0; 281 282 for (; n > 0; n--, rela++) 283 { 284 switch (ELF64_R_TYPE(rela->r_info)) { 285 case R_PARISC_PCREL22F: 286 cnt++; 287 } 288 } 289 290 return cnt; 291 } 292 #endif 293 294 295 /* Free memory returned from module_alloc */ 296 void module_free(struct module *mod, void *module_region) 297 { 298 kfree(mod->arch.section); 299 mod->arch.section = NULL; 300 301 vfree(module_region); 302 } 303 304 /* Additional bytes needed in front of individual sections */ 305 unsigned int arch_mod_section_prepend(struct module *mod, 306 unsigned int section) 307 { 308 /* size needed for all stubs of this section (including 309 * one additional for correct alignment of the stubs) */ 310 return (mod->arch.section[section].stub_entries + 1) 311 * sizeof(struct stub_entry); 312 } 313 314 #define CONST 315 int module_frob_arch_sections(CONST Elf_Ehdr *hdr, 316 CONST Elf_Shdr *sechdrs, 317 CONST char *secstrings, 318 struct module *me) 319 { 320 unsigned long gots = 0, fdescs = 0, len; 321 unsigned int i; 322 323 len = hdr->e_shnum * sizeof(me->arch.section[0]); 324 me->arch.section = kzalloc(len, GFP_KERNEL); 325 if (!me->arch.section) 326 return -ENOMEM; 327 328 for (i = 1; i < hdr->e_shnum; i++) { 329 const Elf_Rela *rels = (void *)sechdrs[i].sh_addr; 330 unsigned long nrels = sechdrs[i].sh_size / sizeof(*rels); 331 unsigned int count, s; 332 333 if (strncmp(secstrings + sechdrs[i].sh_name, 334 ".PARISC.unwind", 14) == 0) 335 me->arch.unwind_section = i; 336 337 if (sechdrs[i].sh_type != SHT_RELA) 338 continue; 339 340 /* some of these are not relevant for 32-bit/64-bit 341 * we leave them here to make the code common. the 342 * compiler will do its thing and optimize out the 343 * stuff we don't need 344 */ 345 gots += count_gots(rels, nrels); 346 fdescs += count_fdescs(rels, nrels); 347 348 /* XXX: By sorting the relocs and finding duplicate entries 349 * we could reduce the number of necessary stubs and save 350 * some memory. */ 351 count = count_stubs(rels, nrels); 352 if (!count) 353 continue; 354 355 /* so we need relocation stubs. reserve necessary memory. */ 356 /* sh_info gives the section for which we need to add stubs. */ 357 s = sechdrs[i].sh_info; 358 359 /* each code section should only have one relocation section */ 360 WARN_ON(me->arch.section[s].stub_entries); 361 362 /* store number of stubs we need for this section */ 363 me->arch.section[s].stub_entries += count; 364 } 365 366 /* align things a bit */ 367 me->core_size = ALIGN(me->core_size, 16); 368 me->arch.got_offset = me->core_size; 369 me->core_size += gots * sizeof(struct got_entry); 370 371 me->core_size = ALIGN(me->core_size, 16); 372 me->arch.fdesc_offset = me->core_size; 373 me->core_size += fdescs * sizeof(Elf_Fdesc); 374 375 me->arch.got_max = gots; 376 me->arch.fdesc_max = fdescs; 377 378 return 0; 379 } 380 381 #ifdef CONFIG_64BIT 382 static Elf64_Word get_got(struct module *me, unsigned long value, long addend) 383 { 384 unsigned int i; 385 struct got_entry *got; 386 387 value += addend; 388 389 BUG_ON(value == 0); 390 391 got = me->module_core + me->arch.got_offset; 392 for (i = 0; got[i].addr; i++) 393 if (got[i].addr == value) 394 goto out; 395 396 BUG_ON(++me->arch.got_count > me->arch.got_max); 397 398 got[i].addr = value; 399 out: 400 DEBUGP("GOT ENTRY %d[%x] val %lx\n", i, i*sizeof(struct got_entry), 401 value); 402 return i * sizeof(struct got_entry); 403 } 404 #endif /* CONFIG_64BIT */ 405 406 #ifdef CONFIG_64BIT 407 static Elf_Addr get_fdesc(struct module *me, unsigned long value) 408 { 409 Elf_Fdesc *fdesc = me->module_core + me->arch.fdesc_offset; 410 411 if (!value) { 412 printk(KERN_ERR "%s: zero OPD requested!\n", me->name); 413 return 0; 414 } 415 416 /* Look for existing fdesc entry. */ 417 while (fdesc->addr) { 418 if (fdesc->addr == value) 419 return (Elf_Addr)fdesc; 420 fdesc++; 421 } 422 423 BUG_ON(++me->arch.fdesc_count > me->arch.fdesc_max); 424 425 /* Create new one */ 426 fdesc->addr = value; 427 fdesc->gp = (Elf_Addr)me->module_core + me->arch.got_offset; 428 return (Elf_Addr)fdesc; 429 } 430 #endif /* CONFIG_64BIT */ 431 432 enum elf_stub_type { 433 ELF_STUB_GOT, 434 ELF_STUB_MILLI, 435 ELF_STUB_DIRECT, 436 }; 437 438 static Elf_Addr get_stub(struct module *me, unsigned long value, long addend, 439 enum elf_stub_type stub_type, Elf_Addr loc0, unsigned int targetsec) 440 { 441 struct stub_entry *stub; 442 int __maybe_unused d; 443 444 /* initialize stub_offset to point in front of the section */ 445 if (!me->arch.section[targetsec].stub_offset) { 446 loc0 -= (me->arch.section[targetsec].stub_entries + 1) * 447 sizeof(struct stub_entry); 448 /* get correct alignment for the stubs */ 449 loc0 = ALIGN(loc0, sizeof(struct stub_entry)); 450 me->arch.section[targetsec].stub_offset = loc0; 451 } 452 453 /* get address of stub entry */ 454 stub = (void *) me->arch.section[targetsec].stub_offset; 455 me->arch.section[targetsec].stub_offset += sizeof(struct stub_entry); 456 457 /* do not write outside available stub area */ 458 BUG_ON(0 == me->arch.section[targetsec].stub_entries--); 459 460 461 #ifndef CONFIG_64BIT 462 /* for 32-bit the stub looks like this: 463 * ldil L'XXX,%r1 464 * be,n R'XXX(%sr4,%r1) 465 */ 466 //value = *(unsigned long *)((value + addend) & ~3); /* why? */ 467 468 stub->insns[0] = 0x20200000; /* ldil L'XXX,%r1 */ 469 stub->insns[1] = 0xe0202002; /* be,n R'XXX(%sr4,%r1) */ 470 471 stub->insns[0] |= reassemble_21(lrsel(value, addend)); 472 stub->insns[1] |= reassemble_17(rrsel(value, addend) / 4); 473 474 #else 475 /* for 64-bit we have three kinds of stubs: 476 * for normal function calls: 477 * ldd 0(%dp),%dp 478 * ldd 10(%dp), %r1 479 * bve (%r1) 480 * ldd 18(%dp), %dp 481 * 482 * for millicode: 483 * ldil 0, %r1 484 * ldo 0(%r1), %r1 485 * ldd 10(%r1), %r1 486 * bve,n (%r1) 487 * 488 * for direct branches (jumps between different section of the 489 * same module): 490 * ldil 0, %r1 491 * ldo 0(%r1), %r1 492 * bve,n (%r1) 493 */ 494 switch (stub_type) { 495 case ELF_STUB_GOT: 496 d = get_got(me, value, addend); 497 if (d <= 15) { 498 /* Format 5 */ 499 stub->insns[0] = 0x0f6010db; /* ldd 0(%dp),%dp */ 500 stub->insns[0] |= low_sign_unext(d, 5) << 16; 501 } else { 502 /* Format 3 */ 503 stub->insns[0] = 0x537b0000; /* ldd 0(%dp),%dp */ 504 stub->insns[0] |= reassemble_16a(d); 505 } 506 stub->insns[1] = 0x53610020; /* ldd 10(%dp),%r1 */ 507 stub->insns[2] = 0xe820d000; /* bve (%r1) */ 508 stub->insns[3] = 0x537b0030; /* ldd 18(%dp),%dp */ 509 break; 510 case ELF_STUB_MILLI: 511 stub->insns[0] = 0x20200000; /* ldil 0,%r1 */ 512 stub->insns[1] = 0x34210000; /* ldo 0(%r1), %r1 */ 513 stub->insns[2] = 0x50210020; /* ldd 10(%r1),%r1 */ 514 stub->insns[3] = 0xe820d002; /* bve,n (%r1) */ 515 516 stub->insns[0] |= reassemble_21(lrsel(value, addend)); 517 stub->insns[1] |= reassemble_14(rrsel(value, addend)); 518 break; 519 case ELF_STUB_DIRECT: 520 stub->insns[0] = 0x20200000; /* ldil 0,%r1 */ 521 stub->insns[1] = 0x34210000; /* ldo 0(%r1), %r1 */ 522 stub->insns[2] = 0xe820d002; /* bve,n (%r1) */ 523 524 stub->insns[0] |= reassemble_21(lrsel(value, addend)); 525 stub->insns[1] |= reassemble_14(rrsel(value, addend)); 526 break; 527 } 528 529 #endif 530 531 return (Elf_Addr)stub; 532 } 533 534 int apply_relocate(Elf_Shdr *sechdrs, 535 const char *strtab, 536 unsigned int symindex, 537 unsigned int relsec, 538 struct module *me) 539 { 540 /* parisc should not need this ... */ 541 printk(KERN_ERR "module %s: RELOCATION unsupported\n", 542 me->name); 543 return -ENOEXEC; 544 } 545 546 #ifndef CONFIG_64BIT 547 int apply_relocate_add(Elf_Shdr *sechdrs, 548 const char *strtab, 549 unsigned int symindex, 550 unsigned int relsec, 551 struct module *me) 552 { 553 int i; 554 Elf32_Rela *rel = (void *)sechdrs[relsec].sh_addr; 555 Elf32_Sym *sym; 556 Elf32_Word *loc; 557 Elf32_Addr val; 558 Elf32_Sword addend; 559 Elf32_Addr dot; 560 Elf_Addr loc0; 561 unsigned int targetsec = sechdrs[relsec].sh_info; 562 //unsigned long dp = (unsigned long)$global$; 563 register unsigned long dp asm ("r27"); 564 565 DEBUGP("Applying relocate section %u to %u\n", relsec, 566 targetsec); 567 for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) { 568 /* This is where to make the change */ 569 loc = (void *)sechdrs[targetsec].sh_addr 570 + rel[i].r_offset; 571 /* This is the start of the target section */ 572 loc0 = sechdrs[targetsec].sh_addr; 573 /* This is the symbol it is referring to */ 574 sym = (Elf32_Sym *)sechdrs[symindex].sh_addr 575 + ELF32_R_SYM(rel[i].r_info); 576 if (!sym->st_value) { 577 printk(KERN_WARNING "%s: Unknown symbol %s\n", 578 me->name, strtab + sym->st_name); 579 return -ENOENT; 580 } 581 //dot = (sechdrs[relsec].sh_addr + rel->r_offset) & ~0x03; 582 dot = (Elf32_Addr)loc & ~0x03; 583 584 val = sym->st_value; 585 addend = rel[i].r_addend; 586 587 #if 0 588 #define r(t) ELF32_R_TYPE(rel[i].r_info)==t ? #t : 589 DEBUGP("Symbol %s loc 0x%x val 0x%x addend 0x%x: %s\n", 590 strtab + sym->st_name, 591 (uint32_t)loc, val, addend, 592 r(R_PARISC_PLABEL32) 593 r(R_PARISC_DIR32) 594 r(R_PARISC_DIR21L) 595 r(R_PARISC_DIR14R) 596 r(R_PARISC_SEGREL32) 597 r(R_PARISC_DPREL21L) 598 r(R_PARISC_DPREL14R) 599 r(R_PARISC_PCREL17F) 600 r(R_PARISC_PCREL22F) 601 "UNKNOWN"); 602 #undef r 603 #endif 604 605 switch (ELF32_R_TYPE(rel[i].r_info)) { 606 case R_PARISC_PLABEL32: 607 /* 32-bit function address */ 608 /* no function descriptors... */ 609 *loc = fsel(val, addend); 610 break; 611 case R_PARISC_DIR32: 612 /* direct 32-bit ref */ 613 *loc = fsel(val, addend); 614 break; 615 case R_PARISC_DIR21L: 616 /* left 21 bits of effective address */ 617 val = lrsel(val, addend); 618 *loc = mask(*loc, 21) | reassemble_21(val); 619 break; 620 case R_PARISC_DIR14R: 621 /* right 14 bits of effective address */ 622 val = rrsel(val, addend); 623 *loc = mask(*loc, 14) | reassemble_14(val); 624 break; 625 case R_PARISC_SEGREL32: 626 /* 32-bit segment relative address */ 627 /* See note about special handling of SEGREL32 at 628 * the beginning of this file. 629 */ 630 *loc = fsel(val, addend); 631 break; 632 case R_PARISC_DPREL21L: 633 /* left 21 bit of relative address */ 634 val = lrsel(val - dp, addend); 635 *loc = mask(*loc, 21) | reassemble_21(val); 636 break; 637 case R_PARISC_DPREL14R: 638 /* right 14 bit of relative address */ 639 val = rrsel(val - dp, addend); 640 *loc = mask(*loc, 14) | reassemble_14(val); 641 break; 642 case R_PARISC_PCREL17F: 643 /* 17-bit PC relative address */ 644 /* calculate direct call offset */ 645 val += addend; 646 val = (val - dot - 8)/4; 647 if (!RELOC_REACHABLE(val, 17)) { 648 /* direct distance too far, create 649 * stub entry instead */ 650 val = get_stub(me, sym->st_value, addend, 651 ELF_STUB_DIRECT, loc0, targetsec); 652 val = (val - dot - 8)/4; 653 CHECK_RELOC(val, 17); 654 } 655 *loc = (*loc & ~0x1f1ffd) | reassemble_17(val); 656 break; 657 case R_PARISC_PCREL22F: 658 /* 22-bit PC relative address; only defined for pa20 */ 659 /* calculate direct call offset */ 660 val += addend; 661 val = (val - dot - 8)/4; 662 if (!RELOC_REACHABLE(val, 22)) { 663 /* direct distance too far, create 664 * stub entry instead */ 665 val = get_stub(me, sym->st_value, addend, 666 ELF_STUB_DIRECT, loc0, targetsec); 667 val = (val - dot - 8)/4; 668 CHECK_RELOC(val, 22); 669 } 670 *loc = (*loc & ~0x3ff1ffd) | reassemble_22(val); 671 break; 672 673 default: 674 printk(KERN_ERR "module %s: Unknown relocation: %u\n", 675 me->name, ELF32_R_TYPE(rel[i].r_info)); 676 return -ENOEXEC; 677 } 678 } 679 680 return 0; 681 } 682 683 #else 684 int apply_relocate_add(Elf_Shdr *sechdrs, 685 const char *strtab, 686 unsigned int symindex, 687 unsigned int relsec, 688 struct module *me) 689 { 690 int i; 691 Elf64_Rela *rel = (void *)sechdrs[relsec].sh_addr; 692 Elf64_Sym *sym; 693 Elf64_Word *loc; 694 Elf64_Xword *loc64; 695 Elf64_Addr val; 696 Elf64_Sxword addend; 697 Elf64_Addr dot; 698 Elf_Addr loc0; 699 unsigned int targetsec = sechdrs[relsec].sh_info; 700 701 DEBUGP("Applying relocate section %u to %u\n", relsec, 702 targetsec); 703 for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) { 704 /* This is where to make the change */ 705 loc = (void *)sechdrs[targetsec].sh_addr 706 + rel[i].r_offset; 707 /* This is the start of the target section */ 708 loc0 = sechdrs[targetsec].sh_addr; 709 /* This is the symbol it is referring to */ 710 sym = (Elf64_Sym *)sechdrs[symindex].sh_addr 711 + ELF64_R_SYM(rel[i].r_info); 712 if (!sym->st_value) { 713 printk(KERN_WARNING "%s: Unknown symbol %s\n", 714 me->name, strtab + sym->st_name); 715 return -ENOENT; 716 } 717 //dot = (sechdrs[relsec].sh_addr + rel->r_offset) & ~0x03; 718 dot = (Elf64_Addr)loc & ~0x03; 719 loc64 = (Elf64_Xword *)loc; 720 721 val = sym->st_value; 722 addend = rel[i].r_addend; 723 724 #if 0 725 #define r(t) ELF64_R_TYPE(rel[i].r_info)==t ? #t : 726 printk("Symbol %s loc %p val 0x%Lx addend 0x%Lx: %s\n", 727 strtab + sym->st_name, 728 loc, val, addend, 729 r(R_PARISC_LTOFF14R) 730 r(R_PARISC_LTOFF21L) 731 r(R_PARISC_PCREL22F) 732 r(R_PARISC_DIR64) 733 r(R_PARISC_SEGREL32) 734 r(R_PARISC_FPTR64) 735 "UNKNOWN"); 736 #undef r 737 #endif 738 739 switch (ELF64_R_TYPE(rel[i].r_info)) { 740 case R_PARISC_LTOFF21L: 741 /* LT-relative; left 21 bits */ 742 val = get_got(me, val, addend); 743 DEBUGP("LTOFF21L Symbol %s loc %p val %lx\n", 744 strtab + sym->st_name, 745 loc, val); 746 val = lrsel(val, 0); 747 *loc = mask(*loc, 21) | reassemble_21(val); 748 break; 749 case R_PARISC_LTOFF14R: 750 /* L(ltoff(val+addend)) */ 751 /* LT-relative; right 14 bits */ 752 val = get_got(me, val, addend); 753 val = rrsel(val, 0); 754 DEBUGP("LTOFF14R Symbol %s loc %p val %lx\n", 755 strtab + sym->st_name, 756 loc, val); 757 *loc = mask(*loc, 14) | reassemble_14(val); 758 break; 759 case R_PARISC_PCREL22F: 760 /* PC-relative; 22 bits */ 761 DEBUGP("PCREL22F Symbol %s loc %p val %lx\n", 762 strtab + sym->st_name, 763 loc, val); 764 val += addend; 765 /* can we reach it locally? */ 766 if (in_local(me, (void *)val)) { 767 /* this is the case where the symbol is local 768 * to the module, but in a different section, 769 * so stub the jump in case it's more than 22 770 * bits away */ 771 val = (val - dot - 8)/4; 772 if (!RELOC_REACHABLE(val, 22)) { 773 /* direct distance too far, create 774 * stub entry instead */ 775 val = get_stub(me, sym->st_value, 776 addend, ELF_STUB_DIRECT, 777 loc0, targetsec); 778 } else { 779 /* Ok, we can reach it directly. */ 780 val = sym->st_value; 781 val += addend; 782 } 783 } else { 784 val = sym->st_value; 785 if (strncmp(strtab + sym->st_name, "$$", 2) 786 == 0) 787 val = get_stub(me, val, addend, ELF_STUB_MILLI, 788 loc0, targetsec); 789 else 790 val = get_stub(me, val, addend, ELF_STUB_GOT, 791 loc0, targetsec); 792 } 793 DEBUGP("STUB FOR %s loc %lx, val %lx+%lx at %lx\n", 794 strtab + sym->st_name, loc, sym->st_value, 795 addend, val); 796 val = (val - dot - 8)/4; 797 CHECK_RELOC(val, 22); 798 *loc = (*loc & ~0x3ff1ffd) | reassemble_22(val); 799 break; 800 case R_PARISC_DIR64: 801 /* 64-bit effective address */ 802 *loc64 = val + addend; 803 break; 804 case R_PARISC_SEGREL32: 805 /* 32-bit segment relative address */ 806 /* See note about special handling of SEGREL32 at 807 * the beginning of this file. 808 */ 809 *loc = fsel(val, addend); 810 break; 811 case R_PARISC_FPTR64: 812 /* 64-bit function address */ 813 if(in_local(me, (void *)(val + addend))) { 814 *loc64 = get_fdesc(me, val+addend); 815 DEBUGP("FDESC for %s at %p points to %lx\n", 816 strtab + sym->st_name, *loc64, 817 ((Elf_Fdesc *)*loc64)->addr); 818 } else { 819 /* if the symbol is not local to this 820 * module then val+addend is a pointer 821 * to the function descriptor */ 822 DEBUGP("Non local FPTR64 Symbol %s loc %p val %lx\n", 823 strtab + sym->st_name, 824 loc, val); 825 *loc64 = val + addend; 826 } 827 break; 828 829 default: 830 printk(KERN_ERR "module %s: Unknown relocation: %Lu\n", 831 me->name, ELF64_R_TYPE(rel[i].r_info)); 832 return -ENOEXEC; 833 } 834 } 835 return 0; 836 } 837 #endif 838 839 static void 840 register_unwind_table(struct module *me, 841 const Elf_Shdr *sechdrs) 842 { 843 unsigned char *table, *end; 844 unsigned long gp; 845 846 if (!me->arch.unwind_section) 847 return; 848 849 table = (unsigned char *)sechdrs[me->arch.unwind_section].sh_addr; 850 end = table + sechdrs[me->arch.unwind_section].sh_size; 851 gp = (Elf_Addr)me->module_core + me->arch.got_offset; 852 853 DEBUGP("register_unwind_table(), sect = %d at 0x%p - 0x%p (gp=0x%lx)\n", 854 me->arch.unwind_section, table, end, gp); 855 me->arch.unwind = unwind_table_add(me->name, 0, gp, table, end); 856 } 857 858 static void 859 deregister_unwind_table(struct module *me) 860 { 861 if (me->arch.unwind) 862 unwind_table_remove(me->arch.unwind); 863 } 864 865 int module_finalize(const Elf_Ehdr *hdr, 866 const Elf_Shdr *sechdrs, 867 struct module *me) 868 { 869 int i; 870 unsigned long nsyms; 871 const char *strtab = NULL; 872 Elf_Sym *newptr, *oldptr; 873 Elf_Shdr *symhdr = NULL; 874 #ifdef DEBUG 875 Elf_Fdesc *entry; 876 u32 *addr; 877 878 entry = (Elf_Fdesc *)me->init; 879 printk("FINALIZE, ->init FPTR is %p, GP %lx ADDR %lx\n", entry, 880 entry->gp, entry->addr); 881 addr = (u32 *)entry->addr; 882 printk("INSNS: %x %x %x %x\n", 883 addr[0], addr[1], addr[2], addr[3]); 884 printk("got entries used %ld, gots max %ld\n" 885 "fdescs used %ld, fdescs max %ld\n", 886 me->arch.got_count, me->arch.got_max, 887 me->arch.fdesc_count, me->arch.fdesc_max); 888 #endif 889 890 register_unwind_table(me, sechdrs); 891 892 /* haven't filled in me->symtab yet, so have to find it 893 * ourselves */ 894 for (i = 1; i < hdr->e_shnum; i++) { 895 if(sechdrs[i].sh_type == SHT_SYMTAB 896 && (sechdrs[i].sh_flags & SHF_ALLOC)) { 897 int strindex = sechdrs[i].sh_link; 898 /* FIXME: AWFUL HACK 899 * The cast is to drop the const from 900 * the sechdrs pointer */ 901 symhdr = (Elf_Shdr *)&sechdrs[i]; 902 strtab = (char *)sechdrs[strindex].sh_addr; 903 break; 904 } 905 } 906 907 DEBUGP("module %s: strtab %p, symhdr %p\n", 908 me->name, strtab, symhdr); 909 910 if(me->arch.got_count > MAX_GOTS) { 911 printk(KERN_ERR "%s: Global Offset Table overflow (used %ld, allowed %d)\n", 912 me->name, me->arch.got_count, MAX_GOTS); 913 return -EINVAL; 914 } 915 916 kfree(me->arch.section); 917 me->arch.section = NULL; 918 919 /* no symbol table */ 920 if(symhdr == NULL) 921 return 0; 922 923 oldptr = (void *)symhdr->sh_addr; 924 newptr = oldptr + 1; /* we start counting at 1 */ 925 nsyms = symhdr->sh_size / sizeof(Elf_Sym); 926 DEBUGP("OLD num_symtab %lu\n", nsyms); 927 928 for (i = 1; i < nsyms; i++) { 929 oldptr++; /* note, count starts at 1 so preincrement */ 930 if(strncmp(strtab + oldptr->st_name, 931 ".L", 2) == 0) 932 continue; 933 934 if(newptr != oldptr) 935 *newptr++ = *oldptr; 936 else 937 newptr++; 938 939 } 940 nsyms = newptr - (Elf_Sym *)symhdr->sh_addr; 941 DEBUGP("NEW num_symtab %lu\n", nsyms); 942 symhdr->sh_size = nsyms * sizeof(Elf_Sym); 943 return module_bug_finalize(hdr, sechdrs, me); 944 } 945 946 void module_arch_cleanup(struct module *mod) 947 { 948 deregister_unwind_table(mod); 949 module_bug_cleanup(mod); 950 } 951