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 #include <linux/mm.h> 65 #include <linux/slab.h> 66 67 #include <asm/pgtable.h> 68 #include <asm/unwind.h> 69 70 #if 0 71 #define DEBUGP printk 72 #else 73 #define DEBUGP(fmt...) 74 #endif 75 76 #define RELOC_REACHABLE(val, bits) \ 77 (( ( !((val) & (1<<((bits)-1))) && ((val)>>(bits)) != 0 ) || \ 78 ( ((val) & (1<<((bits)-1))) && ((val)>>(bits)) != (((__typeof__(val))(~0))>>((bits)+2)))) ? \ 79 0 : 1) 80 81 #define CHECK_RELOC(val, bits) \ 82 if (!RELOC_REACHABLE(val, bits)) { \ 83 printk(KERN_ERR "module %s relocation of symbol %s is out of range (0x%lx in %d bits)\n", \ 84 me->name, strtab + sym->st_name, (unsigned long)val, bits); \ 85 return -ENOEXEC; \ 86 } 87 88 /* Maximum number of GOT entries. We use a long displacement ldd from 89 * the bottom of the table, which has a maximum signed displacement of 90 * 0x3fff; however, since we're only going forward, this becomes 91 * 0x1fff, and thus, since each GOT entry is 8 bytes long we can have 92 * at most 1023 entries. 93 * To overcome this 14bit displacement with some kernel modules, we'll 94 * use instead the unusal 16bit displacement method (see reassemble_16a) 95 * which gives us a maximum positive displacement of 0x7fff, and as such 96 * allows us to allocate up to 4095 GOT entries. */ 97 #define MAX_GOTS 4095 98 99 /* three functions to determine where in the module core 100 * or init pieces the location is */ 101 static inline int in_init(struct module *me, void *loc) 102 { 103 return (loc >= me->module_init && 104 loc <= (me->module_init + me->init_size)); 105 } 106 107 static inline int in_core(struct module *me, void *loc) 108 { 109 return (loc >= me->module_core && 110 loc <= (me->module_core + me->core_size)); 111 } 112 113 static inline int in_local(struct module *me, void *loc) 114 { 115 return in_init(me, loc) || in_core(me, loc); 116 } 117 118 #ifndef CONFIG_64BIT 119 struct got_entry { 120 Elf32_Addr addr; 121 }; 122 123 struct stub_entry { 124 Elf32_Word insns[2]; /* each stub entry has two insns */ 125 }; 126 #else 127 struct got_entry { 128 Elf64_Addr addr; 129 }; 130 131 struct stub_entry { 132 Elf64_Word insns[4]; /* each stub entry has four insns */ 133 }; 134 #endif 135 136 /* Field selection types defined by hppa */ 137 #define rnd(x) (((x)+0x1000)&~0x1fff) 138 /* fsel: full 32 bits */ 139 #define fsel(v,a) ((v)+(a)) 140 /* lsel: select left 21 bits */ 141 #define lsel(v,a) (((v)+(a))>>11) 142 /* rsel: select right 11 bits */ 143 #define rsel(v,a) (((v)+(a))&0x7ff) 144 /* lrsel with rounding of addend to nearest 8k */ 145 #define lrsel(v,a) (((v)+rnd(a))>>11) 146 /* rrsel with rounding of addend to nearest 8k */ 147 #define rrsel(v,a) ((((v)+rnd(a))&0x7ff)+((a)-rnd(a))) 148 149 #define mask(x,sz) ((x) & ~((1<<(sz))-1)) 150 151 152 /* The reassemble_* functions prepare an immediate value for 153 insertion into an opcode. pa-risc uses all sorts of weird bitfields 154 in the instruction to hold the value. */ 155 static inline int sign_unext(int x, int len) 156 { 157 int len_ones; 158 159 len_ones = (1 << len) - 1; 160 return x & len_ones; 161 } 162 163 static inline int low_sign_unext(int x, int len) 164 { 165 int sign, temp; 166 167 sign = (x >> (len-1)) & 1; 168 temp = sign_unext(x, len-1); 169 return (temp << 1) | sign; 170 } 171 172 static inline int reassemble_14(int as14) 173 { 174 return (((as14 & 0x1fff) << 1) | 175 ((as14 & 0x2000) >> 13)); 176 } 177 178 static inline int reassemble_16a(int as16) 179 { 180 int s, t; 181 182 /* Unusual 16-bit encoding, for wide mode only. */ 183 t = (as16 << 1) & 0xffff; 184 s = (as16 & 0x8000); 185 return (t ^ s ^ (s >> 1)) | (s >> 15); 186 } 187 188 189 static inline int reassemble_17(int as17) 190 { 191 return (((as17 & 0x10000) >> 16) | 192 ((as17 & 0x0f800) << 5) | 193 ((as17 & 0x00400) >> 8) | 194 ((as17 & 0x003ff) << 3)); 195 } 196 197 static inline int reassemble_21(int as21) 198 { 199 return (((as21 & 0x100000) >> 20) | 200 ((as21 & 0x0ffe00) >> 8) | 201 ((as21 & 0x000180) << 7) | 202 ((as21 & 0x00007c) << 14) | 203 ((as21 & 0x000003) << 12)); 204 } 205 206 static inline int reassemble_22(int as22) 207 { 208 return (((as22 & 0x200000) >> 21) | 209 ((as22 & 0x1f0000) << 5) | 210 ((as22 & 0x00f800) << 5) | 211 ((as22 & 0x000400) >> 8) | 212 ((as22 & 0x0003ff) << 3)); 213 } 214 215 void *module_alloc(unsigned long size) 216 { 217 if (size == 0) 218 return NULL; 219 /* using RWX means less protection for modules, but it's 220 * easier than trying to map the text, data, init_text and 221 * init_data correctly */ 222 return __vmalloc_node_range(size, 1, VMALLOC_START, VMALLOC_END, 223 GFP_KERNEL | __GFP_HIGHMEM, 224 PAGE_KERNEL_RWX, -1, 225 __builtin_return_address(0)); 226 } 227 228 #ifndef CONFIG_64BIT 229 static inline unsigned long count_gots(const Elf_Rela *rela, unsigned long n) 230 { 231 return 0; 232 } 233 234 static inline unsigned long count_fdescs(const Elf_Rela *rela, unsigned long n) 235 { 236 return 0; 237 } 238 239 static inline unsigned long count_stubs(const Elf_Rela *rela, unsigned long n) 240 { 241 unsigned long cnt = 0; 242 243 for (; n > 0; n--, rela++) 244 { 245 switch (ELF32_R_TYPE(rela->r_info)) { 246 case R_PARISC_PCREL17F: 247 case R_PARISC_PCREL22F: 248 cnt++; 249 } 250 } 251 252 return cnt; 253 } 254 #else 255 static inline unsigned long count_gots(const Elf_Rela *rela, unsigned long n) 256 { 257 unsigned long cnt = 0; 258 259 for (; n > 0; n--, rela++) 260 { 261 switch (ELF64_R_TYPE(rela->r_info)) { 262 case R_PARISC_LTOFF21L: 263 case R_PARISC_LTOFF14R: 264 case R_PARISC_PCREL22F: 265 cnt++; 266 } 267 } 268 269 return cnt; 270 } 271 272 static inline unsigned long count_fdescs(const Elf_Rela *rela, unsigned long n) 273 { 274 unsigned long cnt = 0; 275 276 for (; n > 0; n--, rela++) 277 { 278 switch (ELF64_R_TYPE(rela->r_info)) { 279 case R_PARISC_FPTR64: 280 cnt++; 281 } 282 } 283 284 return cnt; 285 } 286 287 static inline unsigned long count_stubs(const Elf_Rela *rela, unsigned long n) 288 { 289 unsigned long cnt = 0; 290 291 for (; n > 0; n--, rela++) 292 { 293 switch (ELF64_R_TYPE(rela->r_info)) { 294 case R_PARISC_PCREL22F: 295 cnt++; 296 } 297 } 298 299 return cnt; 300 } 301 #endif 302 303 304 /* Free memory returned from module_alloc */ 305 void module_free(struct module *mod, void *module_region) 306 { 307 kfree(mod->arch.section); 308 mod->arch.section = NULL; 309 310 vfree(module_region); 311 } 312 313 /* Additional bytes needed in front of individual sections */ 314 unsigned int arch_mod_section_prepend(struct module *mod, 315 unsigned int section) 316 { 317 /* size needed for all stubs of this section (including 318 * one additional for correct alignment of the stubs) */ 319 return (mod->arch.section[section].stub_entries + 1) 320 * sizeof(struct stub_entry); 321 } 322 323 #define CONST 324 int module_frob_arch_sections(CONST Elf_Ehdr *hdr, 325 CONST Elf_Shdr *sechdrs, 326 CONST char *secstrings, 327 struct module *me) 328 { 329 unsigned long gots = 0, fdescs = 0, len; 330 unsigned int i; 331 332 len = hdr->e_shnum * sizeof(me->arch.section[0]); 333 me->arch.section = kzalloc(len, GFP_KERNEL); 334 if (!me->arch.section) 335 return -ENOMEM; 336 337 for (i = 1; i < hdr->e_shnum; i++) { 338 const Elf_Rela *rels = (void *)sechdrs[i].sh_addr; 339 unsigned long nrels = sechdrs[i].sh_size / sizeof(*rels); 340 unsigned int count, s; 341 342 if (strncmp(secstrings + sechdrs[i].sh_name, 343 ".PARISC.unwind", 14) == 0) 344 me->arch.unwind_section = i; 345 346 if (sechdrs[i].sh_type != SHT_RELA) 347 continue; 348 349 /* some of these are not relevant for 32-bit/64-bit 350 * we leave them here to make the code common. the 351 * compiler will do its thing and optimize out the 352 * stuff we don't need 353 */ 354 gots += count_gots(rels, nrels); 355 fdescs += count_fdescs(rels, nrels); 356 357 /* XXX: By sorting the relocs and finding duplicate entries 358 * we could reduce the number of necessary stubs and save 359 * some memory. */ 360 count = count_stubs(rels, nrels); 361 if (!count) 362 continue; 363 364 /* so we need relocation stubs. reserve necessary memory. */ 365 /* sh_info gives the section for which we need to add stubs. */ 366 s = sechdrs[i].sh_info; 367 368 /* each code section should only have one relocation section */ 369 WARN_ON(me->arch.section[s].stub_entries); 370 371 /* store number of stubs we need for this section */ 372 me->arch.section[s].stub_entries += count; 373 } 374 375 /* align things a bit */ 376 me->core_size = ALIGN(me->core_size, 16); 377 me->arch.got_offset = me->core_size; 378 me->core_size += gots * sizeof(struct got_entry); 379 380 me->core_size = ALIGN(me->core_size, 16); 381 me->arch.fdesc_offset = me->core_size; 382 me->core_size += fdescs * sizeof(Elf_Fdesc); 383 384 me->arch.got_max = gots; 385 me->arch.fdesc_max = fdescs; 386 387 return 0; 388 } 389 390 #ifdef CONFIG_64BIT 391 static Elf64_Word get_got(struct module *me, unsigned long value, long addend) 392 { 393 unsigned int i; 394 struct got_entry *got; 395 396 value += addend; 397 398 BUG_ON(value == 0); 399 400 got = me->module_core + me->arch.got_offset; 401 for (i = 0; got[i].addr; i++) 402 if (got[i].addr == value) 403 goto out; 404 405 BUG_ON(++me->arch.got_count > me->arch.got_max); 406 407 got[i].addr = value; 408 out: 409 DEBUGP("GOT ENTRY %d[%x] val %lx\n", i, i*sizeof(struct got_entry), 410 value); 411 return i * sizeof(struct got_entry); 412 } 413 #endif /* CONFIG_64BIT */ 414 415 #ifdef CONFIG_64BIT 416 static Elf_Addr get_fdesc(struct module *me, unsigned long value) 417 { 418 Elf_Fdesc *fdesc = me->module_core + me->arch.fdesc_offset; 419 420 if (!value) { 421 printk(KERN_ERR "%s: zero OPD requested!\n", me->name); 422 return 0; 423 } 424 425 /* Look for existing fdesc entry. */ 426 while (fdesc->addr) { 427 if (fdesc->addr == value) 428 return (Elf_Addr)fdesc; 429 fdesc++; 430 } 431 432 BUG_ON(++me->arch.fdesc_count > me->arch.fdesc_max); 433 434 /* Create new one */ 435 fdesc->addr = value; 436 fdesc->gp = (Elf_Addr)me->module_core + me->arch.got_offset; 437 return (Elf_Addr)fdesc; 438 } 439 #endif /* CONFIG_64BIT */ 440 441 enum elf_stub_type { 442 ELF_STUB_GOT, 443 ELF_STUB_MILLI, 444 ELF_STUB_DIRECT, 445 }; 446 447 static Elf_Addr get_stub(struct module *me, unsigned long value, long addend, 448 enum elf_stub_type stub_type, Elf_Addr loc0, unsigned int targetsec) 449 { 450 struct stub_entry *stub; 451 int __maybe_unused d; 452 453 /* initialize stub_offset to point in front of the section */ 454 if (!me->arch.section[targetsec].stub_offset) { 455 loc0 -= (me->arch.section[targetsec].stub_entries + 1) * 456 sizeof(struct stub_entry); 457 /* get correct alignment for the stubs */ 458 loc0 = ALIGN(loc0, sizeof(struct stub_entry)); 459 me->arch.section[targetsec].stub_offset = loc0; 460 } 461 462 /* get address of stub entry */ 463 stub = (void *) me->arch.section[targetsec].stub_offset; 464 me->arch.section[targetsec].stub_offset += sizeof(struct stub_entry); 465 466 /* do not write outside available stub area */ 467 BUG_ON(0 == me->arch.section[targetsec].stub_entries--); 468 469 470 #ifndef CONFIG_64BIT 471 /* for 32-bit the stub looks like this: 472 * ldil L'XXX,%r1 473 * be,n R'XXX(%sr4,%r1) 474 */ 475 //value = *(unsigned long *)((value + addend) & ~3); /* why? */ 476 477 stub->insns[0] = 0x20200000; /* ldil L'XXX,%r1 */ 478 stub->insns[1] = 0xe0202002; /* be,n R'XXX(%sr4,%r1) */ 479 480 stub->insns[0] |= reassemble_21(lrsel(value, addend)); 481 stub->insns[1] |= reassemble_17(rrsel(value, addend) / 4); 482 483 #else 484 /* for 64-bit we have three kinds of stubs: 485 * for normal function calls: 486 * ldd 0(%dp),%dp 487 * ldd 10(%dp), %r1 488 * bve (%r1) 489 * ldd 18(%dp), %dp 490 * 491 * for millicode: 492 * ldil 0, %r1 493 * ldo 0(%r1), %r1 494 * ldd 10(%r1), %r1 495 * bve,n (%r1) 496 * 497 * for direct branches (jumps between different section of the 498 * same module): 499 * ldil 0, %r1 500 * ldo 0(%r1), %r1 501 * bve,n (%r1) 502 */ 503 switch (stub_type) { 504 case ELF_STUB_GOT: 505 d = get_got(me, value, addend); 506 if (d <= 15) { 507 /* Format 5 */ 508 stub->insns[0] = 0x0f6010db; /* ldd 0(%dp),%dp */ 509 stub->insns[0] |= low_sign_unext(d, 5) << 16; 510 } else { 511 /* Format 3 */ 512 stub->insns[0] = 0x537b0000; /* ldd 0(%dp),%dp */ 513 stub->insns[0] |= reassemble_16a(d); 514 } 515 stub->insns[1] = 0x53610020; /* ldd 10(%dp),%r1 */ 516 stub->insns[2] = 0xe820d000; /* bve (%r1) */ 517 stub->insns[3] = 0x537b0030; /* ldd 18(%dp),%dp */ 518 break; 519 case ELF_STUB_MILLI: 520 stub->insns[0] = 0x20200000; /* ldil 0,%r1 */ 521 stub->insns[1] = 0x34210000; /* ldo 0(%r1), %r1 */ 522 stub->insns[2] = 0x50210020; /* ldd 10(%r1),%r1 */ 523 stub->insns[3] = 0xe820d002; /* bve,n (%r1) */ 524 525 stub->insns[0] |= reassemble_21(lrsel(value, addend)); 526 stub->insns[1] |= reassemble_14(rrsel(value, addend)); 527 break; 528 case ELF_STUB_DIRECT: 529 stub->insns[0] = 0x20200000; /* ldil 0,%r1 */ 530 stub->insns[1] = 0x34210000; /* ldo 0(%r1), %r1 */ 531 stub->insns[2] = 0xe820d002; /* bve,n (%r1) */ 532 533 stub->insns[0] |= reassemble_21(lrsel(value, addend)); 534 stub->insns[1] |= reassemble_14(rrsel(value, addend)); 535 break; 536 } 537 538 #endif 539 540 return (Elf_Addr)stub; 541 } 542 543 int apply_relocate(Elf_Shdr *sechdrs, 544 const char *strtab, 545 unsigned int symindex, 546 unsigned int relsec, 547 struct module *me) 548 { 549 /* parisc should not need this ... */ 550 printk(KERN_ERR "module %s: RELOCATION unsupported\n", 551 me->name); 552 return -ENOEXEC; 553 } 554 555 #ifndef CONFIG_64BIT 556 int apply_relocate_add(Elf_Shdr *sechdrs, 557 const char *strtab, 558 unsigned int symindex, 559 unsigned int relsec, 560 struct module *me) 561 { 562 int i; 563 Elf32_Rela *rel = (void *)sechdrs[relsec].sh_addr; 564 Elf32_Sym *sym; 565 Elf32_Word *loc; 566 Elf32_Addr val; 567 Elf32_Sword addend; 568 Elf32_Addr dot; 569 Elf_Addr loc0; 570 unsigned int targetsec = sechdrs[relsec].sh_info; 571 //unsigned long dp = (unsigned long)$global$; 572 register unsigned long dp asm ("r27"); 573 574 DEBUGP("Applying relocate section %u to %u\n", relsec, 575 targetsec); 576 for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) { 577 /* This is where to make the change */ 578 loc = (void *)sechdrs[targetsec].sh_addr 579 + rel[i].r_offset; 580 /* This is the start of the target section */ 581 loc0 = sechdrs[targetsec].sh_addr; 582 /* This is the symbol it is referring to */ 583 sym = (Elf32_Sym *)sechdrs[symindex].sh_addr 584 + ELF32_R_SYM(rel[i].r_info); 585 if (!sym->st_value) { 586 printk(KERN_WARNING "%s: Unknown symbol %s\n", 587 me->name, strtab + sym->st_name); 588 return -ENOENT; 589 } 590 //dot = (sechdrs[relsec].sh_addr + rel->r_offset) & ~0x03; 591 dot = (Elf32_Addr)loc & ~0x03; 592 593 val = sym->st_value; 594 addend = rel[i].r_addend; 595 596 #if 0 597 #define r(t) ELF32_R_TYPE(rel[i].r_info)==t ? #t : 598 DEBUGP("Symbol %s loc 0x%x val 0x%x addend 0x%x: %s\n", 599 strtab + sym->st_name, 600 (uint32_t)loc, val, addend, 601 r(R_PARISC_PLABEL32) 602 r(R_PARISC_DIR32) 603 r(R_PARISC_DIR21L) 604 r(R_PARISC_DIR14R) 605 r(R_PARISC_SEGREL32) 606 r(R_PARISC_DPREL21L) 607 r(R_PARISC_DPREL14R) 608 r(R_PARISC_PCREL17F) 609 r(R_PARISC_PCREL22F) 610 "UNKNOWN"); 611 #undef r 612 #endif 613 614 switch (ELF32_R_TYPE(rel[i].r_info)) { 615 case R_PARISC_PLABEL32: 616 /* 32-bit function address */ 617 /* no function descriptors... */ 618 *loc = fsel(val, addend); 619 break; 620 case R_PARISC_DIR32: 621 /* direct 32-bit ref */ 622 *loc = fsel(val, addend); 623 break; 624 case R_PARISC_DIR21L: 625 /* left 21 bits of effective address */ 626 val = lrsel(val, addend); 627 *loc = mask(*loc, 21) | reassemble_21(val); 628 break; 629 case R_PARISC_DIR14R: 630 /* right 14 bits of effective address */ 631 val = rrsel(val, addend); 632 *loc = mask(*loc, 14) | reassemble_14(val); 633 break; 634 case R_PARISC_SEGREL32: 635 /* 32-bit segment relative address */ 636 /* See note about special handling of SEGREL32 at 637 * the beginning of this file. 638 */ 639 *loc = fsel(val, addend); 640 break; 641 case R_PARISC_DPREL21L: 642 /* left 21 bit of relative address */ 643 val = lrsel(val - dp, addend); 644 *loc = mask(*loc, 21) | reassemble_21(val); 645 break; 646 case R_PARISC_DPREL14R: 647 /* right 14 bit of relative address */ 648 val = rrsel(val - dp, addend); 649 *loc = mask(*loc, 14) | reassemble_14(val); 650 break; 651 case R_PARISC_PCREL17F: 652 /* 17-bit PC relative address */ 653 /* calculate direct call offset */ 654 val += addend; 655 val = (val - dot - 8)/4; 656 if (!RELOC_REACHABLE(val, 17)) { 657 /* direct distance too far, create 658 * stub entry instead */ 659 val = get_stub(me, sym->st_value, addend, 660 ELF_STUB_DIRECT, loc0, targetsec); 661 val = (val - dot - 8)/4; 662 CHECK_RELOC(val, 17); 663 } 664 *loc = (*loc & ~0x1f1ffd) | reassemble_17(val); 665 break; 666 case R_PARISC_PCREL22F: 667 /* 22-bit PC relative address; only defined for pa20 */ 668 /* calculate direct call offset */ 669 val += addend; 670 val = (val - dot - 8)/4; 671 if (!RELOC_REACHABLE(val, 22)) { 672 /* direct distance too far, create 673 * stub entry instead */ 674 val = get_stub(me, sym->st_value, addend, 675 ELF_STUB_DIRECT, loc0, targetsec); 676 val = (val - dot - 8)/4; 677 CHECK_RELOC(val, 22); 678 } 679 *loc = (*loc & ~0x3ff1ffd) | reassemble_22(val); 680 break; 681 682 default: 683 printk(KERN_ERR "module %s: Unknown relocation: %u\n", 684 me->name, ELF32_R_TYPE(rel[i].r_info)); 685 return -ENOEXEC; 686 } 687 } 688 689 return 0; 690 } 691 692 #else 693 int apply_relocate_add(Elf_Shdr *sechdrs, 694 const char *strtab, 695 unsigned int symindex, 696 unsigned int relsec, 697 struct module *me) 698 { 699 int i; 700 Elf64_Rela *rel = (void *)sechdrs[relsec].sh_addr; 701 Elf64_Sym *sym; 702 Elf64_Word *loc; 703 Elf64_Xword *loc64; 704 Elf64_Addr val; 705 Elf64_Sxword addend; 706 Elf64_Addr dot; 707 Elf_Addr loc0; 708 unsigned int targetsec = sechdrs[relsec].sh_info; 709 710 DEBUGP("Applying relocate section %u to %u\n", relsec, 711 targetsec); 712 for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) { 713 /* This is where to make the change */ 714 loc = (void *)sechdrs[targetsec].sh_addr 715 + rel[i].r_offset; 716 /* This is the start of the target section */ 717 loc0 = sechdrs[targetsec].sh_addr; 718 /* This is the symbol it is referring to */ 719 sym = (Elf64_Sym *)sechdrs[symindex].sh_addr 720 + ELF64_R_SYM(rel[i].r_info); 721 if (!sym->st_value) { 722 printk(KERN_WARNING "%s: Unknown symbol %s\n", 723 me->name, strtab + sym->st_name); 724 return -ENOENT; 725 } 726 //dot = (sechdrs[relsec].sh_addr + rel->r_offset) & ~0x03; 727 dot = (Elf64_Addr)loc & ~0x03; 728 loc64 = (Elf64_Xword *)loc; 729 730 val = sym->st_value; 731 addend = rel[i].r_addend; 732 733 #if 0 734 #define r(t) ELF64_R_TYPE(rel[i].r_info)==t ? #t : 735 printk("Symbol %s loc %p val 0x%Lx addend 0x%Lx: %s\n", 736 strtab + sym->st_name, 737 loc, val, addend, 738 r(R_PARISC_LTOFF14R) 739 r(R_PARISC_LTOFF21L) 740 r(R_PARISC_PCREL22F) 741 r(R_PARISC_DIR64) 742 r(R_PARISC_SEGREL32) 743 r(R_PARISC_FPTR64) 744 "UNKNOWN"); 745 #undef r 746 #endif 747 748 switch (ELF64_R_TYPE(rel[i].r_info)) { 749 case R_PARISC_LTOFF21L: 750 /* LT-relative; left 21 bits */ 751 val = get_got(me, val, addend); 752 DEBUGP("LTOFF21L Symbol %s loc %p val %lx\n", 753 strtab + sym->st_name, 754 loc, val); 755 val = lrsel(val, 0); 756 *loc = mask(*loc, 21) | reassemble_21(val); 757 break; 758 case R_PARISC_LTOFF14R: 759 /* L(ltoff(val+addend)) */ 760 /* LT-relative; right 14 bits */ 761 val = get_got(me, val, addend); 762 val = rrsel(val, 0); 763 DEBUGP("LTOFF14R Symbol %s loc %p val %lx\n", 764 strtab + sym->st_name, 765 loc, val); 766 *loc = mask(*loc, 14) | reassemble_14(val); 767 break; 768 case R_PARISC_PCREL22F: 769 /* PC-relative; 22 bits */ 770 DEBUGP("PCREL22F Symbol %s loc %p val %lx\n", 771 strtab + sym->st_name, 772 loc, val); 773 val += addend; 774 /* can we reach it locally? */ 775 if (in_local(me, (void *)val)) { 776 /* this is the case where the symbol is local 777 * to the module, but in a different section, 778 * so stub the jump in case it's more than 22 779 * bits away */ 780 val = (val - dot - 8)/4; 781 if (!RELOC_REACHABLE(val, 22)) { 782 /* direct distance too far, create 783 * stub entry instead */ 784 val = get_stub(me, sym->st_value, 785 addend, ELF_STUB_DIRECT, 786 loc0, targetsec); 787 } else { 788 /* Ok, we can reach it directly. */ 789 val = sym->st_value; 790 val += addend; 791 } 792 } else { 793 val = sym->st_value; 794 if (strncmp(strtab + sym->st_name, "$$", 2) 795 == 0) 796 val = get_stub(me, val, addend, ELF_STUB_MILLI, 797 loc0, targetsec); 798 else 799 val = get_stub(me, val, addend, ELF_STUB_GOT, 800 loc0, targetsec); 801 } 802 DEBUGP("STUB FOR %s loc %lx, val %lx+%lx at %lx\n", 803 strtab + sym->st_name, loc, sym->st_value, 804 addend, val); 805 val = (val - dot - 8)/4; 806 CHECK_RELOC(val, 22); 807 *loc = (*loc & ~0x3ff1ffd) | reassemble_22(val); 808 break; 809 case R_PARISC_DIR64: 810 /* 64-bit effective address */ 811 *loc64 = val + addend; 812 break; 813 case R_PARISC_SEGREL32: 814 /* 32-bit segment relative address */ 815 /* See note about special handling of SEGREL32 at 816 * the beginning of this file. 817 */ 818 *loc = fsel(val, addend); 819 break; 820 case R_PARISC_FPTR64: 821 /* 64-bit function address */ 822 if(in_local(me, (void *)(val + addend))) { 823 *loc64 = get_fdesc(me, val+addend); 824 DEBUGP("FDESC for %s at %p points to %lx\n", 825 strtab + sym->st_name, *loc64, 826 ((Elf_Fdesc *)*loc64)->addr); 827 } else { 828 /* if the symbol is not local to this 829 * module then val+addend is a pointer 830 * to the function descriptor */ 831 DEBUGP("Non local FPTR64 Symbol %s loc %p val %lx\n", 832 strtab + sym->st_name, 833 loc, val); 834 *loc64 = val + addend; 835 } 836 break; 837 838 default: 839 printk(KERN_ERR "module %s: Unknown relocation: %Lu\n", 840 me->name, ELF64_R_TYPE(rel[i].r_info)); 841 return -ENOEXEC; 842 } 843 } 844 return 0; 845 } 846 #endif 847 848 static void 849 register_unwind_table(struct module *me, 850 const Elf_Shdr *sechdrs) 851 { 852 unsigned char *table, *end; 853 unsigned long gp; 854 855 if (!me->arch.unwind_section) 856 return; 857 858 table = (unsigned char *)sechdrs[me->arch.unwind_section].sh_addr; 859 end = table + sechdrs[me->arch.unwind_section].sh_size; 860 gp = (Elf_Addr)me->module_core + me->arch.got_offset; 861 862 DEBUGP("register_unwind_table(), sect = %d at 0x%p - 0x%p (gp=0x%lx)\n", 863 me->arch.unwind_section, table, end, gp); 864 me->arch.unwind = unwind_table_add(me->name, 0, gp, table, end); 865 } 866 867 static void 868 deregister_unwind_table(struct module *me) 869 { 870 if (me->arch.unwind) 871 unwind_table_remove(me->arch.unwind); 872 } 873 874 int module_finalize(const Elf_Ehdr *hdr, 875 const Elf_Shdr *sechdrs, 876 struct module *me) 877 { 878 int i; 879 unsigned long nsyms; 880 const char *strtab = NULL; 881 Elf_Sym *newptr, *oldptr; 882 Elf_Shdr *symhdr = NULL; 883 #ifdef DEBUG 884 Elf_Fdesc *entry; 885 u32 *addr; 886 887 entry = (Elf_Fdesc *)me->init; 888 printk("FINALIZE, ->init FPTR is %p, GP %lx ADDR %lx\n", entry, 889 entry->gp, entry->addr); 890 addr = (u32 *)entry->addr; 891 printk("INSNS: %x %x %x %x\n", 892 addr[0], addr[1], addr[2], addr[3]); 893 printk("got entries used %ld, gots max %ld\n" 894 "fdescs used %ld, fdescs max %ld\n", 895 me->arch.got_count, me->arch.got_max, 896 me->arch.fdesc_count, me->arch.fdesc_max); 897 #endif 898 899 register_unwind_table(me, sechdrs); 900 901 /* haven't filled in me->symtab yet, so have to find it 902 * ourselves */ 903 for (i = 1; i < hdr->e_shnum; i++) { 904 if(sechdrs[i].sh_type == SHT_SYMTAB 905 && (sechdrs[i].sh_flags & SHF_ALLOC)) { 906 int strindex = sechdrs[i].sh_link; 907 /* FIXME: AWFUL HACK 908 * The cast is to drop the const from 909 * the sechdrs pointer */ 910 symhdr = (Elf_Shdr *)&sechdrs[i]; 911 strtab = (char *)sechdrs[strindex].sh_addr; 912 break; 913 } 914 } 915 916 DEBUGP("module %s: strtab %p, symhdr %p\n", 917 me->name, strtab, symhdr); 918 919 if(me->arch.got_count > MAX_GOTS) { 920 printk(KERN_ERR "%s: Global Offset Table overflow (used %ld, allowed %d)\n", 921 me->name, me->arch.got_count, MAX_GOTS); 922 return -EINVAL; 923 } 924 925 kfree(me->arch.section); 926 me->arch.section = NULL; 927 928 /* no symbol table */ 929 if(symhdr == NULL) 930 return 0; 931 932 oldptr = (void *)symhdr->sh_addr; 933 newptr = oldptr + 1; /* we start counting at 1 */ 934 nsyms = symhdr->sh_size / sizeof(Elf_Sym); 935 DEBUGP("OLD num_symtab %lu\n", nsyms); 936 937 for (i = 1; i < nsyms; i++) { 938 oldptr++; /* note, count starts at 1 so preincrement */ 939 if(strncmp(strtab + oldptr->st_name, 940 ".L", 2) == 0) 941 continue; 942 943 if(newptr != oldptr) 944 *newptr++ = *oldptr; 945 else 946 newptr++; 947 948 } 949 nsyms = newptr - (Elf_Sym *)symhdr->sh_addr; 950 DEBUGP("NEW num_symtab %lu\n", nsyms); 951 symhdr->sh_size = nsyms * sizeof(Elf_Sym); 952 return 0; 953 } 954 955 void module_arch_cleanup(struct module *mod) 956 { 957 deregister_unwind_table(mod); 958 } 959