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->init_layout.base; 46 * else 47 * val -= (uint32_t)me->core_layout.base; 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 #include <asm/sections.h> 70 71 #if 0 72 #define DEBUGP printk 73 #else 74 #define DEBUGP(fmt...) 75 #endif 76 77 #define RELOC_REACHABLE(val, bits) \ 78 (( ( !((val) & (1<<((bits)-1))) && ((val)>>(bits)) != 0 ) || \ 79 ( ((val) & (1<<((bits)-1))) && ((val)>>(bits)) != (((__typeof__(val))(~0))>>((bits)+2)))) ? \ 80 0 : 1) 81 82 #define CHECK_RELOC(val, bits) \ 83 if (!RELOC_REACHABLE(val, bits)) { \ 84 printk(KERN_ERR "module %s relocation of symbol %s is out of range (0x%lx in %d bits)\n", \ 85 me->name, strtab + sym->st_name, (unsigned long)val, bits); \ 86 return -ENOEXEC; \ 87 } 88 89 /* Maximum number of GOT entries. We use a long displacement ldd from 90 * the bottom of the table, which has a maximum signed displacement of 91 * 0x3fff; however, since we're only going forward, this becomes 92 * 0x1fff, and thus, since each GOT entry is 8 bytes long we can have 93 * at most 1023 entries. 94 * To overcome this 14bit displacement with some kernel modules, we'll 95 * use instead the unusal 16bit displacement method (see reassemble_16a) 96 * which gives us a maximum positive displacement of 0x7fff, and as such 97 * allows us to allocate up to 4095 GOT entries. */ 98 #define MAX_GOTS 4095 99 100 /* three functions to determine where in the module core 101 * or init pieces the location is */ 102 static inline int in_init(struct module *me, void *loc) 103 { 104 return (loc >= me->init_layout.base && 105 loc <= (me->init_layout.base + me->init_layout.size)); 106 } 107 108 static inline int in_core(struct module *me, void *loc) 109 { 110 return (loc >= me->core_layout.base && 111 loc <= (me->core_layout.base + me->core_layout.size)); 112 } 113 114 static inline int in_local(struct module *me, void *loc) 115 { 116 return in_init(me, loc) || in_core(me, loc); 117 } 118 119 #ifndef CONFIG_64BIT 120 struct got_entry { 121 Elf32_Addr addr; 122 }; 123 124 struct stub_entry { 125 Elf32_Word insns[2]; /* each stub entry has two insns */ 126 }; 127 #else 128 struct got_entry { 129 Elf64_Addr addr; 130 }; 131 132 struct stub_entry { 133 Elf64_Word insns[4]; /* each stub entry has four insns */ 134 }; 135 #endif 136 137 /* Field selection types defined by hppa */ 138 #define rnd(x) (((x)+0x1000)&~0x1fff) 139 /* fsel: full 32 bits */ 140 #define fsel(v,a) ((v)+(a)) 141 /* lsel: select left 21 bits */ 142 #define lsel(v,a) (((v)+(a))>>11) 143 /* rsel: select right 11 bits */ 144 #define rsel(v,a) (((v)+(a))&0x7ff) 145 /* lrsel with rounding of addend to nearest 8k */ 146 #define lrsel(v,a) (((v)+rnd(a))>>11) 147 /* rrsel with rounding of addend to nearest 8k */ 148 #define rrsel(v,a) ((((v)+rnd(a))&0x7ff)+((a)-rnd(a))) 149 150 #define mask(x,sz) ((x) & ~((1<<(sz))-1)) 151 152 153 /* The reassemble_* functions prepare an immediate value for 154 insertion into an opcode. pa-risc uses all sorts of weird bitfields 155 in the instruction to hold the value. */ 156 static inline int sign_unext(int x, int len) 157 { 158 int len_ones; 159 160 len_ones = (1 << len) - 1; 161 return x & len_ones; 162 } 163 164 static inline int low_sign_unext(int x, int len) 165 { 166 int sign, temp; 167 168 sign = (x >> (len-1)) & 1; 169 temp = sign_unext(x, len-1); 170 return (temp << 1) | sign; 171 } 172 173 static inline int reassemble_14(int as14) 174 { 175 return (((as14 & 0x1fff) << 1) | 176 ((as14 & 0x2000) >> 13)); 177 } 178 179 static inline int reassemble_16a(int as16) 180 { 181 int s, t; 182 183 /* Unusual 16-bit encoding, for wide mode only. */ 184 t = (as16 << 1) & 0xffff; 185 s = (as16 & 0x8000); 186 return (t ^ s ^ (s >> 1)) | (s >> 15); 187 } 188 189 190 static inline int reassemble_17(int as17) 191 { 192 return (((as17 & 0x10000) >> 16) | 193 ((as17 & 0x0f800) << 5) | 194 ((as17 & 0x00400) >> 8) | 195 ((as17 & 0x003ff) << 3)); 196 } 197 198 static inline int reassemble_21(int as21) 199 { 200 return (((as21 & 0x100000) >> 20) | 201 ((as21 & 0x0ffe00) >> 8) | 202 ((as21 & 0x000180) << 7) | 203 ((as21 & 0x00007c) << 14) | 204 ((as21 & 0x000003) << 12)); 205 } 206 207 static inline int reassemble_22(int as22) 208 { 209 return (((as22 & 0x200000) >> 21) | 210 ((as22 & 0x1f0000) << 5) | 211 ((as22 & 0x00f800) << 5) | 212 ((as22 & 0x000400) >> 8) | 213 ((as22 & 0x0003ff) << 3)); 214 } 215 216 void *module_alloc(unsigned long size) 217 { 218 /* using RWX means less protection for modules, but it's 219 * easier than trying to map the text, data, init_text and 220 * init_data correctly */ 221 return __vmalloc_node_range(size, 1, VMALLOC_START, VMALLOC_END, 222 GFP_KERNEL, 223 PAGE_KERNEL_RWX, 0, NUMA_NO_NODE, 224 __builtin_return_address(0)); 225 } 226 227 #ifndef CONFIG_64BIT 228 static inline unsigned long count_gots(const Elf_Rela *rela, unsigned long n) 229 { 230 return 0; 231 } 232 233 static inline unsigned long count_fdescs(const Elf_Rela *rela, unsigned long n) 234 { 235 return 0; 236 } 237 238 static inline unsigned long count_stubs(const Elf_Rela *rela, unsigned long n) 239 { 240 unsigned long cnt = 0; 241 242 for (; n > 0; n--, rela++) 243 { 244 switch (ELF32_R_TYPE(rela->r_info)) { 245 case R_PARISC_PCREL17F: 246 case R_PARISC_PCREL22F: 247 cnt++; 248 } 249 } 250 251 return cnt; 252 } 253 #else 254 static inline unsigned long count_gots(const Elf_Rela *rela, unsigned long n) 255 { 256 unsigned long cnt = 0; 257 258 for (; n > 0; n--, rela++) 259 { 260 switch (ELF64_R_TYPE(rela->r_info)) { 261 case R_PARISC_LTOFF21L: 262 case R_PARISC_LTOFF14R: 263 case R_PARISC_PCREL22F: 264 cnt++; 265 } 266 } 267 268 return cnt; 269 } 270 271 static inline unsigned long count_fdescs(const Elf_Rela *rela, unsigned long n) 272 { 273 unsigned long cnt = 0; 274 275 for (; n > 0; n--, rela++) 276 { 277 switch (ELF64_R_TYPE(rela->r_info)) { 278 case R_PARISC_FPTR64: 279 cnt++; 280 } 281 } 282 283 return cnt; 284 } 285 286 static inline unsigned long count_stubs(const Elf_Rela *rela, unsigned long n) 287 { 288 unsigned long cnt = 0; 289 290 for (; n > 0; n--, rela++) 291 { 292 switch (ELF64_R_TYPE(rela->r_info)) { 293 case R_PARISC_PCREL22F: 294 cnt++; 295 } 296 } 297 298 return cnt; 299 } 300 #endif 301 302 void module_arch_freeing_init(struct module *mod) 303 { 304 kfree(mod->arch.section); 305 mod->arch.section = NULL; 306 } 307 308 /* Additional bytes needed in front of individual sections */ 309 unsigned int arch_mod_section_prepend(struct module *mod, 310 unsigned int section) 311 { 312 /* size needed for all stubs of this section (including 313 * one additional for correct alignment of the stubs) */ 314 return (mod->arch.section[section].stub_entries + 1) 315 * sizeof(struct stub_entry); 316 } 317 318 #define CONST 319 int module_frob_arch_sections(CONST Elf_Ehdr *hdr, 320 CONST Elf_Shdr *sechdrs, 321 CONST char *secstrings, 322 struct module *me) 323 { 324 unsigned long gots = 0, fdescs = 0, len; 325 unsigned int i; 326 327 len = hdr->e_shnum * sizeof(me->arch.section[0]); 328 me->arch.section = kzalloc(len, GFP_KERNEL); 329 if (!me->arch.section) 330 return -ENOMEM; 331 332 for (i = 1; i < hdr->e_shnum; i++) { 333 const Elf_Rela *rels = (void *)sechdrs[i].sh_addr; 334 unsigned long nrels = sechdrs[i].sh_size / sizeof(*rels); 335 unsigned int count, s; 336 337 if (strncmp(secstrings + sechdrs[i].sh_name, 338 ".PARISC.unwind", 14) == 0) 339 me->arch.unwind_section = i; 340 341 if (sechdrs[i].sh_type != SHT_RELA) 342 continue; 343 344 /* some of these are not relevant for 32-bit/64-bit 345 * we leave them here to make the code common. the 346 * compiler will do its thing and optimize out the 347 * stuff we don't need 348 */ 349 gots += count_gots(rels, nrels); 350 fdescs += count_fdescs(rels, nrels); 351 352 /* XXX: By sorting the relocs and finding duplicate entries 353 * we could reduce the number of necessary stubs and save 354 * some memory. */ 355 count = count_stubs(rels, nrels); 356 if (!count) 357 continue; 358 359 /* so we need relocation stubs. reserve necessary memory. */ 360 /* sh_info gives the section for which we need to add stubs. */ 361 s = sechdrs[i].sh_info; 362 363 /* each code section should only have one relocation section */ 364 WARN_ON(me->arch.section[s].stub_entries); 365 366 /* store number of stubs we need for this section */ 367 me->arch.section[s].stub_entries += count; 368 } 369 370 /* align things a bit */ 371 me->core_layout.size = ALIGN(me->core_layout.size, 16); 372 me->arch.got_offset = me->core_layout.size; 373 me->core_layout.size += gots * sizeof(struct got_entry); 374 375 me->core_layout.size = ALIGN(me->core_layout.size, 16); 376 me->arch.fdesc_offset = me->core_layout.size; 377 me->core_layout.size += fdescs * sizeof(Elf_Fdesc); 378 379 me->arch.got_max = gots; 380 me->arch.fdesc_max = fdescs; 381 382 return 0; 383 } 384 385 #ifdef CONFIG_64BIT 386 static Elf64_Word get_got(struct module *me, unsigned long value, long addend) 387 { 388 unsigned int i; 389 struct got_entry *got; 390 391 value += addend; 392 393 BUG_ON(value == 0); 394 395 got = me->core_layout.base + me->arch.got_offset; 396 for (i = 0; got[i].addr; i++) 397 if (got[i].addr == value) 398 goto out; 399 400 BUG_ON(++me->arch.got_count > me->arch.got_max); 401 402 got[i].addr = value; 403 out: 404 DEBUGP("GOT ENTRY %d[%x] val %lx\n", i, i*sizeof(struct got_entry), 405 value); 406 return i * sizeof(struct got_entry); 407 } 408 #endif /* CONFIG_64BIT */ 409 410 #ifdef CONFIG_64BIT 411 static Elf_Addr get_fdesc(struct module *me, unsigned long value) 412 { 413 Elf_Fdesc *fdesc = me->core_layout.base + me->arch.fdesc_offset; 414 415 if (!value) { 416 printk(KERN_ERR "%s: zero OPD requested!\n", me->name); 417 return 0; 418 } 419 420 /* Look for existing fdesc entry. */ 421 while (fdesc->addr) { 422 if (fdesc->addr == value) 423 return (Elf_Addr)fdesc; 424 fdesc++; 425 } 426 427 BUG_ON(++me->arch.fdesc_count > me->arch.fdesc_max); 428 429 /* Create new one */ 430 fdesc->addr = value; 431 fdesc->gp = (Elf_Addr)me->core_layout.base + me->arch.got_offset; 432 return (Elf_Addr)fdesc; 433 } 434 #endif /* CONFIG_64BIT */ 435 436 enum elf_stub_type { 437 ELF_STUB_GOT, 438 ELF_STUB_MILLI, 439 ELF_STUB_DIRECT, 440 }; 441 442 static Elf_Addr get_stub(struct module *me, unsigned long value, long addend, 443 enum elf_stub_type stub_type, Elf_Addr loc0, unsigned int targetsec) 444 { 445 struct stub_entry *stub; 446 int __maybe_unused d; 447 448 /* initialize stub_offset to point in front of the section */ 449 if (!me->arch.section[targetsec].stub_offset) { 450 loc0 -= (me->arch.section[targetsec].stub_entries + 1) * 451 sizeof(struct stub_entry); 452 /* get correct alignment for the stubs */ 453 loc0 = ALIGN(loc0, sizeof(struct stub_entry)); 454 me->arch.section[targetsec].stub_offset = loc0; 455 } 456 457 /* get address of stub entry */ 458 stub = (void *) me->arch.section[targetsec].stub_offset; 459 me->arch.section[targetsec].stub_offset += sizeof(struct stub_entry); 460 461 /* do not write outside available stub area */ 462 BUG_ON(0 == me->arch.section[targetsec].stub_entries--); 463 464 465 #ifndef CONFIG_64BIT 466 /* for 32-bit the stub looks like this: 467 * ldil L'XXX,%r1 468 * be,n R'XXX(%sr4,%r1) 469 */ 470 //value = *(unsigned long *)((value + addend) & ~3); /* why? */ 471 472 stub->insns[0] = 0x20200000; /* ldil L'XXX,%r1 */ 473 stub->insns[1] = 0xe0202002; /* be,n R'XXX(%sr4,%r1) */ 474 475 stub->insns[0] |= reassemble_21(lrsel(value, addend)); 476 stub->insns[1] |= reassemble_17(rrsel(value, addend) / 4); 477 478 #else 479 /* for 64-bit we have three kinds of stubs: 480 * for normal function calls: 481 * ldd 0(%dp),%dp 482 * ldd 10(%dp), %r1 483 * bve (%r1) 484 * ldd 18(%dp), %dp 485 * 486 * for millicode: 487 * ldil 0, %r1 488 * ldo 0(%r1), %r1 489 * ldd 10(%r1), %r1 490 * bve,n (%r1) 491 * 492 * for direct branches (jumps between different section of the 493 * same module): 494 * ldil 0, %r1 495 * ldo 0(%r1), %r1 496 * bve,n (%r1) 497 */ 498 switch (stub_type) { 499 case ELF_STUB_GOT: 500 d = get_got(me, value, addend); 501 if (d <= 15) { 502 /* Format 5 */ 503 stub->insns[0] = 0x0f6010db; /* ldd 0(%dp),%dp */ 504 stub->insns[0] |= low_sign_unext(d, 5) << 16; 505 } else { 506 /* Format 3 */ 507 stub->insns[0] = 0x537b0000; /* ldd 0(%dp),%dp */ 508 stub->insns[0] |= reassemble_16a(d); 509 } 510 stub->insns[1] = 0x53610020; /* ldd 10(%dp),%r1 */ 511 stub->insns[2] = 0xe820d000; /* bve (%r1) */ 512 stub->insns[3] = 0x537b0030; /* ldd 18(%dp),%dp */ 513 break; 514 case ELF_STUB_MILLI: 515 stub->insns[0] = 0x20200000; /* ldil 0,%r1 */ 516 stub->insns[1] = 0x34210000; /* ldo 0(%r1), %r1 */ 517 stub->insns[2] = 0x50210020; /* ldd 10(%r1),%r1 */ 518 stub->insns[3] = 0xe820d002; /* bve,n (%r1) */ 519 520 stub->insns[0] |= reassemble_21(lrsel(value, addend)); 521 stub->insns[1] |= reassemble_14(rrsel(value, addend)); 522 break; 523 case ELF_STUB_DIRECT: 524 stub->insns[0] = 0x20200000; /* ldil 0,%r1 */ 525 stub->insns[1] = 0x34210000; /* ldo 0(%r1), %r1 */ 526 stub->insns[2] = 0xe820d002; /* bve,n (%r1) */ 527 528 stub->insns[0] |= reassemble_21(lrsel(value, addend)); 529 stub->insns[1] |= reassemble_14(rrsel(value, addend)); 530 break; 531 } 532 533 #endif 534 535 return (Elf_Addr)stub; 536 } 537 538 #ifndef CONFIG_64BIT 539 int apply_relocate_add(Elf_Shdr *sechdrs, 540 const char *strtab, 541 unsigned int symindex, 542 unsigned int relsec, 543 struct module *me) 544 { 545 int i; 546 Elf32_Rela *rel = (void *)sechdrs[relsec].sh_addr; 547 Elf32_Sym *sym; 548 Elf32_Word *loc; 549 Elf32_Addr val; 550 Elf32_Sword addend; 551 Elf32_Addr dot; 552 Elf_Addr loc0; 553 unsigned int targetsec = sechdrs[relsec].sh_info; 554 //unsigned long dp = (unsigned long)$global$; 555 register unsigned long dp asm ("r27"); 556 557 DEBUGP("Applying relocate section %u to %u\n", relsec, 558 targetsec); 559 for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) { 560 /* This is where to make the change */ 561 loc = (void *)sechdrs[targetsec].sh_addr 562 + rel[i].r_offset; 563 /* This is the start of the target section */ 564 loc0 = sechdrs[targetsec].sh_addr; 565 /* This is the symbol it is referring to */ 566 sym = (Elf32_Sym *)sechdrs[symindex].sh_addr 567 + ELF32_R_SYM(rel[i].r_info); 568 if (!sym->st_value) { 569 printk(KERN_WARNING "%s: Unknown symbol %s\n", 570 me->name, strtab + sym->st_name); 571 return -ENOENT; 572 } 573 //dot = (sechdrs[relsec].sh_addr + rel->r_offset) & ~0x03; 574 dot = (Elf32_Addr)loc & ~0x03; 575 576 val = sym->st_value; 577 addend = rel[i].r_addend; 578 579 #if 0 580 #define r(t) ELF32_R_TYPE(rel[i].r_info)==t ? #t : 581 DEBUGP("Symbol %s loc 0x%x val 0x%x addend 0x%x: %s\n", 582 strtab + sym->st_name, 583 (uint32_t)loc, val, addend, 584 r(R_PARISC_PLABEL32) 585 r(R_PARISC_DIR32) 586 r(R_PARISC_DIR21L) 587 r(R_PARISC_DIR14R) 588 r(R_PARISC_SEGREL32) 589 r(R_PARISC_DPREL21L) 590 r(R_PARISC_DPREL14R) 591 r(R_PARISC_PCREL17F) 592 r(R_PARISC_PCREL22F) 593 "UNKNOWN"); 594 #undef r 595 #endif 596 597 switch (ELF32_R_TYPE(rel[i].r_info)) { 598 case R_PARISC_PLABEL32: 599 /* 32-bit function address */ 600 /* no function descriptors... */ 601 *loc = fsel(val, addend); 602 break; 603 case R_PARISC_DIR32: 604 /* direct 32-bit ref */ 605 *loc = fsel(val, addend); 606 break; 607 case R_PARISC_DIR21L: 608 /* left 21 bits of effective address */ 609 val = lrsel(val, addend); 610 *loc = mask(*loc, 21) | reassemble_21(val); 611 break; 612 case R_PARISC_DIR14R: 613 /* right 14 bits of effective address */ 614 val = rrsel(val, addend); 615 *loc = mask(*loc, 14) | reassemble_14(val); 616 break; 617 case R_PARISC_SEGREL32: 618 /* 32-bit segment relative address */ 619 /* See note about special handling of SEGREL32 at 620 * the beginning of this file. 621 */ 622 *loc = fsel(val, addend); 623 break; 624 case R_PARISC_SECREL32: 625 /* 32-bit section relative address. */ 626 *loc = fsel(val, addend); 627 break; 628 case R_PARISC_DPREL21L: 629 /* left 21 bit of relative address */ 630 val = lrsel(val - dp, addend); 631 *loc = mask(*loc, 21) | reassemble_21(val); 632 break; 633 case R_PARISC_DPREL14R: 634 /* right 14 bit of relative address */ 635 val = rrsel(val - dp, addend); 636 *loc = mask(*loc, 14) | reassemble_14(val); 637 break; 638 case R_PARISC_PCREL17F: 639 /* 17-bit PC relative address */ 640 /* calculate direct call offset */ 641 val += addend; 642 val = (val - dot - 8)/4; 643 if (!RELOC_REACHABLE(val, 17)) { 644 /* direct distance too far, create 645 * stub entry instead */ 646 val = get_stub(me, sym->st_value, addend, 647 ELF_STUB_DIRECT, loc0, targetsec); 648 val = (val - dot - 8)/4; 649 CHECK_RELOC(val, 17); 650 } 651 *loc = (*loc & ~0x1f1ffd) | reassemble_17(val); 652 break; 653 case R_PARISC_PCREL22F: 654 /* 22-bit PC relative address; only defined for pa20 */ 655 /* calculate direct call offset */ 656 val += addend; 657 val = (val - dot - 8)/4; 658 if (!RELOC_REACHABLE(val, 22)) { 659 /* direct distance too far, create 660 * stub entry instead */ 661 val = get_stub(me, sym->st_value, addend, 662 ELF_STUB_DIRECT, loc0, targetsec); 663 val = (val - dot - 8)/4; 664 CHECK_RELOC(val, 22); 665 } 666 *loc = (*loc & ~0x3ff1ffd) | reassemble_22(val); 667 break; 668 case R_PARISC_PCREL32: 669 /* 32-bit PC relative address */ 670 *loc = val - dot - 8 + addend; 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_PCREL32: 801 /* 32-bit PC relative address */ 802 *loc = val - dot - 8 + addend; 803 break; 804 case R_PARISC_DIR64: 805 /* 64-bit effective address */ 806 *loc64 = val + addend; 807 break; 808 case R_PARISC_SEGREL32: 809 /* 32-bit segment relative address */ 810 /* See note about special handling of SEGREL32 at 811 * the beginning of this file. 812 */ 813 *loc = fsel(val, addend); 814 break; 815 case R_PARISC_SECREL32: 816 /* 32-bit section relative address. */ 817 *loc = fsel(val, addend); 818 break; 819 case R_PARISC_FPTR64: 820 /* 64-bit function address */ 821 if(in_local(me, (void *)(val + addend))) { 822 *loc64 = get_fdesc(me, val+addend); 823 DEBUGP("FDESC for %s at %p points to %lx\n", 824 strtab + sym->st_name, *loc64, 825 ((Elf_Fdesc *)*loc64)->addr); 826 } else { 827 /* if the symbol is not local to this 828 * module then val+addend is a pointer 829 * to the function descriptor */ 830 DEBUGP("Non local FPTR64 Symbol %s loc %p val %lx\n", 831 strtab + sym->st_name, 832 loc, val); 833 *loc64 = val + addend; 834 } 835 break; 836 837 default: 838 printk(KERN_ERR "module %s: Unknown relocation: %Lu\n", 839 me->name, ELF64_R_TYPE(rel[i].r_info)); 840 return -ENOEXEC; 841 } 842 } 843 return 0; 844 } 845 #endif 846 847 static void 848 register_unwind_table(struct module *me, 849 const Elf_Shdr *sechdrs) 850 { 851 unsigned char *table, *end; 852 unsigned long gp; 853 854 if (!me->arch.unwind_section) 855 return; 856 857 table = (unsigned char *)sechdrs[me->arch.unwind_section].sh_addr; 858 end = table + sechdrs[me->arch.unwind_section].sh_size; 859 gp = (Elf_Addr)me->core_layout.base + me->arch.got_offset; 860 861 DEBUGP("register_unwind_table(), sect = %d at 0x%p - 0x%p (gp=0x%lx)\n", 862 me->arch.unwind_section, table, end, gp); 863 me->arch.unwind = unwind_table_add(me->name, 0, gp, table, end); 864 } 865 866 static void 867 deregister_unwind_table(struct module *me) 868 { 869 if (me->arch.unwind) 870 unwind_table_remove(me->arch.unwind); 871 } 872 873 int module_finalize(const Elf_Ehdr *hdr, 874 const Elf_Shdr *sechdrs, 875 struct module *me) 876 { 877 int i; 878 unsigned long nsyms; 879 const char *strtab = NULL; 880 const Elf_Shdr *s; 881 char *secstrings; 882 Elf_Sym *newptr, *oldptr; 883 Elf_Shdr *symhdr = NULL; 884 #ifdef DEBUG 885 Elf_Fdesc *entry; 886 u32 *addr; 887 888 entry = (Elf_Fdesc *)me->init; 889 printk("FINALIZE, ->init FPTR is %p, GP %lx ADDR %lx\n", entry, 890 entry->gp, entry->addr); 891 addr = (u32 *)entry->addr; 892 printk("INSNS: %x %x %x %x\n", 893 addr[0], addr[1], addr[2], addr[3]); 894 printk("got entries used %ld, gots max %ld\n" 895 "fdescs used %ld, fdescs max %ld\n", 896 me->arch.got_count, me->arch.got_max, 897 me->arch.fdesc_count, me->arch.fdesc_max); 898 #endif 899 900 register_unwind_table(me, sechdrs); 901 902 /* haven't filled in me->symtab yet, so have to find it 903 * ourselves */ 904 for (i = 1; i < hdr->e_shnum; i++) { 905 if(sechdrs[i].sh_type == SHT_SYMTAB 906 && (sechdrs[i].sh_flags & SHF_ALLOC)) { 907 int strindex = sechdrs[i].sh_link; 908 /* FIXME: AWFUL HACK 909 * The cast is to drop the const from 910 * the sechdrs pointer */ 911 symhdr = (Elf_Shdr *)&sechdrs[i]; 912 strtab = (char *)sechdrs[strindex].sh_addr; 913 break; 914 } 915 } 916 917 DEBUGP("module %s: strtab %p, symhdr %p\n", 918 me->name, strtab, symhdr); 919 920 if(me->arch.got_count > MAX_GOTS) { 921 printk(KERN_ERR "%s: Global Offset Table overflow (used %ld, allowed %d)\n", 922 me->name, me->arch.got_count, MAX_GOTS); 923 return -EINVAL; 924 } 925 926 kfree(me->arch.section); 927 me->arch.section = NULL; 928 929 /* no symbol table */ 930 if(symhdr == NULL) 931 return 0; 932 933 oldptr = (void *)symhdr->sh_addr; 934 newptr = oldptr + 1; /* we start counting at 1 */ 935 nsyms = symhdr->sh_size / sizeof(Elf_Sym); 936 DEBUGP("OLD num_symtab %lu\n", nsyms); 937 938 for (i = 1; i < nsyms; i++) { 939 oldptr++; /* note, count starts at 1 so preincrement */ 940 if(strncmp(strtab + oldptr->st_name, 941 ".L", 2) == 0) 942 continue; 943 944 if(newptr != oldptr) 945 *newptr++ = *oldptr; 946 else 947 newptr++; 948 949 } 950 nsyms = newptr - (Elf_Sym *)symhdr->sh_addr; 951 DEBUGP("NEW num_symtab %lu\n", nsyms); 952 symhdr->sh_size = nsyms * sizeof(Elf_Sym); 953 954 /* find .altinstructions section */ 955 secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset; 956 for (s = sechdrs; s < sechdrs + hdr->e_shnum; s++) { 957 void *aseg = (void *) s->sh_addr; 958 char *secname = secstrings + s->sh_name; 959 960 if (!strcmp(".altinstructions", secname)) 961 /* patch .altinstructions */ 962 apply_alternatives(aseg, aseg + s->sh_size, me->name); 963 } 964 965 return 0; 966 } 967 968 void module_arch_cleanup(struct module *mod) 969 { 970 deregister_unwind_table(mod); 971 } 972 973 #ifdef CONFIG_64BIT 974 void *dereference_module_function_descriptor(struct module *mod, void *ptr) 975 { 976 unsigned long start_opd = (Elf64_Addr)mod->core_layout.base + 977 mod->arch.fdesc_offset; 978 unsigned long end_opd = start_opd + 979 mod->arch.fdesc_count * sizeof(Elf64_Fdesc); 980 981 if (ptr < (void *)start_opd || ptr >= (void *)end_opd) 982 return ptr; 983 984 return dereference_function_descriptor(ptr); 985 } 986 #endif 987