Loading...
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 | // SPDX-License-Identifier: GPL-2.0-or-later /* Kernel dynamically loadable module help for PARISC. * * The best reference for this stuff is probably the Processor- * Specific ELF Supplement for PA-RISC: * https://parisc.wiki.kernel.org/index.php/File:Elf-pa-hp.pdf * * Linux/PA-RISC Project * Copyright (C) 2003 Randolph Chung <tausq at debian . org> * Copyright (C) 2008 Helge Deller <deller@gmx.de> * * Notes: * - PLT stub handling * On 32bit (and sometimes 64bit) and with big kernel modules like xfs or * ipv6 the relocation types R_PARISC_PCREL17F and R_PARISC_PCREL22F may * fail to reach their PLT stub if we only create one big stub array for * all sections at the beginning of the core or init section. * Instead we now insert individual PLT stub entries directly in front of * of the code sections where the stubs are actually called. * This reduces the distance between the PCREL location and the stub entry * so that the relocations can be fulfilled. * While calculating the final layout of the kernel module in memory, the * kernel module loader calls arch_mod_section_prepend() to request the * to be reserved amount of memory in front of each individual section. * * - SEGREL32 handling * We are not doing SEGREL32 handling correctly. According to the ABI, we * should do a value offset, like this: * if (in_init(me, (void *)val)) * val -= (uint32_t)me->mem[MOD_INIT_TEXT].base; * else * val -= (uint32_t)me->mem[MOD_TEXT].base; * However, SEGREL32 is used only for PARISC unwind entries, and we want * those entries to have an absolute address, and not just an offset. * * The unwind table mechanism has the ability to specify an offset for * the unwind table; however, because we split off the init functions into * a different piece of memory, it is not possible to do this using a * single offset. Instead, we use the above hack for now. */ #include <linux/moduleloader.h> #include <linux/elf.h> #include <linux/vmalloc.h> #include <linux/fs.h> #include <linux/ftrace.h> #include <linux/string.h> #include <linux/kernel.h> #include <linux/bug.h> #include <linux/mm.h> #include <linux/slab.h> #include <asm/unwind.h> #include <asm/sections.h> #define RELOC_REACHABLE(val, bits) \ (( ( !((val) & (1<<((bits)-1))) && ((val)>>(bits)) != 0 ) || \ ( ((val) & (1<<((bits)-1))) && ((val)>>(bits)) != (((__typeof__(val))(~0))>>((bits)+2)))) ? \ 0 : 1) #define CHECK_RELOC(val, bits) \ if (!RELOC_REACHABLE(val, bits)) { \ printk(KERN_ERR "module %s relocation of symbol %s is out of range (0x%lx in %d bits)\n", \ me->name, strtab + sym->st_name, (unsigned long)val, bits); \ return -ENOEXEC; \ } /* Maximum number of GOT entries. We use a long displacement ldd from * the bottom of the table, which has a maximum signed displacement of * 0x3fff; however, since we're only going forward, this becomes * 0x1fff, and thus, since each GOT entry is 8 bytes long we can have * at most 1023 entries. * To overcome this 14bit displacement with some kernel modules, we'll * use instead the unusal 16bit displacement method (see reassemble_16a) * which gives us a maximum positive displacement of 0x7fff, and as such * allows us to allocate up to 4095 GOT entries. */ #define MAX_GOTS 4095 #ifndef CONFIG_64BIT struct got_entry { Elf32_Addr addr; }; struct stub_entry { Elf32_Word insns[2]; /* each stub entry has two insns */ }; #else struct got_entry { Elf64_Addr addr; }; struct stub_entry { Elf64_Word insns[4]; /* each stub entry has four insns */ }; #endif /* Field selection types defined by hppa */ #define rnd(x) (((x)+0x1000)&~0x1fff) /* fsel: full 32 bits */ #define fsel(v,a) ((v)+(a)) /* lsel: select left 21 bits */ #define lsel(v,a) (((v)+(a))>>11) /* rsel: select right 11 bits */ #define rsel(v,a) (((v)+(a))&0x7ff) /* lrsel with rounding of addend to nearest 8k */ #define lrsel(v,a) (((v)+rnd(a))>>11) /* rrsel with rounding of addend to nearest 8k */ #define rrsel(v,a) ((((v)+rnd(a))&0x7ff)+((a)-rnd(a))) #define mask(x,sz) ((x) & ~((1<<(sz))-1)) /* The reassemble_* functions prepare an immediate value for insertion into an opcode. pa-risc uses all sorts of weird bitfields in the instruction to hold the value. */ static inline int sign_unext(int x, int len) { int len_ones; len_ones = (1 << len) - 1; return x & len_ones; } static inline int low_sign_unext(int x, int len) { int sign, temp; sign = (x >> (len-1)) & 1; temp = sign_unext(x, len-1); return (temp << 1) | sign; } static inline int reassemble_14(int as14) { return (((as14 & 0x1fff) << 1) | ((as14 & 0x2000) >> 13)); } static inline int reassemble_16a(int as16) { int s, t; /* Unusual 16-bit encoding, for wide mode only. */ t = (as16 << 1) & 0xffff; s = (as16 & 0x8000); return (t ^ s ^ (s >> 1)) | (s >> 15); } static inline int reassemble_17(int as17) { return (((as17 & 0x10000) >> 16) | ((as17 & 0x0f800) << 5) | ((as17 & 0x00400) >> 8) | ((as17 & 0x003ff) << 3)); } static inline int reassemble_21(int as21) { return (((as21 & 0x100000) >> 20) | ((as21 & 0x0ffe00) >> 8) | ((as21 & 0x000180) << 7) | ((as21 & 0x00007c) << 14) | ((as21 & 0x000003) << 12)); } static inline int reassemble_22(int as22) { return (((as22 & 0x200000) >> 21) | ((as22 & 0x1f0000) << 5) | ((as22 & 0x00f800) << 5) | ((as22 & 0x000400) >> 8) | ((as22 & 0x0003ff) << 3)); } void *module_alloc(unsigned long size) { /* using RWX means less protection for modules, but it's * easier than trying to map the text, data, init_text and * init_data correctly */ return __vmalloc_node_range(size, 1, VMALLOC_START, VMALLOC_END, GFP_KERNEL, PAGE_KERNEL_RWX, 0, NUMA_NO_NODE, __builtin_return_address(0)); } #ifndef CONFIG_64BIT static inline unsigned long count_gots(const Elf_Rela *rela, unsigned long n) { return 0; } static inline unsigned long count_fdescs(const Elf_Rela *rela, unsigned long n) { return 0; } static inline unsigned long count_stubs(const Elf_Rela *rela, unsigned long n) { unsigned long cnt = 0; for (; n > 0; n--, rela++) { switch (ELF32_R_TYPE(rela->r_info)) { case R_PARISC_PCREL17F: case R_PARISC_PCREL22F: cnt++; } } return cnt; } #else static inline unsigned long count_gots(const Elf_Rela *rela, unsigned long n) { unsigned long cnt = 0; for (; n > 0; n--, rela++) { switch (ELF64_R_TYPE(rela->r_info)) { case R_PARISC_LTOFF21L: case R_PARISC_LTOFF14R: case R_PARISC_PCREL22F: cnt++; } } return cnt; } static inline unsigned long count_fdescs(const Elf_Rela *rela, unsigned long n) { unsigned long cnt = 0; for (; n > 0; n--, rela++) { switch (ELF64_R_TYPE(rela->r_info)) { case R_PARISC_FPTR64: cnt++; } } return cnt; } static inline unsigned long count_stubs(const Elf_Rela *rela, unsigned long n) { unsigned long cnt = 0; for (; n > 0; n--, rela++) { switch (ELF64_R_TYPE(rela->r_info)) { case R_PARISC_PCREL22F: cnt++; } } return cnt; } #endif void module_arch_freeing_init(struct module *mod) { kfree(mod->arch.section); mod->arch.section = NULL; } /* Additional bytes needed in front of individual sections */ unsigned int arch_mod_section_prepend(struct module *mod, unsigned int section) { /* size needed for all stubs of this section (including * one additional for correct alignment of the stubs) */ return (mod->arch.section[section].stub_entries + 1) * sizeof(struct stub_entry); } #define CONST int module_frob_arch_sections(CONST Elf_Ehdr *hdr, CONST Elf_Shdr *sechdrs, CONST char *secstrings, struct module *me) { unsigned long gots = 0, fdescs = 0, len; unsigned int i; struct module_memory *mod_mem; len = hdr->e_shnum * sizeof(me->arch.section[0]); me->arch.section = kzalloc(len, GFP_KERNEL); if (!me->arch.section) return -ENOMEM; for (i = 1; i < hdr->e_shnum; i++) { const Elf_Rela *rels = (void *)sechdrs[i].sh_addr; unsigned long nrels = sechdrs[i].sh_size / sizeof(*rels); unsigned int count, s; if (strncmp(secstrings + sechdrs[i].sh_name, ".PARISC.unwind", 14) == 0) me->arch.unwind_section = i; if (sechdrs[i].sh_type != SHT_RELA) continue; /* some of these are not relevant for 32-bit/64-bit * we leave them here to make the code common. the * compiler will do its thing and optimize out the * stuff we don't need */ gots += count_gots(rels, nrels); fdescs += count_fdescs(rels, nrels); /* XXX: By sorting the relocs and finding duplicate entries * we could reduce the number of necessary stubs and save * some memory. */ count = count_stubs(rels, nrels); if (!count) continue; /* so we need relocation stubs. reserve necessary memory. */ /* sh_info gives the section for which we need to add stubs. */ s = sechdrs[i].sh_info; /* each code section should only have one relocation section */ WARN_ON(me->arch.section[s].stub_entries); /* store number of stubs we need for this section */ me->arch.section[s].stub_entries += count; } mod_mem = &me->mem[MOD_TEXT]; /* align things a bit */ mod_mem->size = ALIGN(mod_mem->size, 16); me->arch.got_offset = mod_mem->size; mod_mem->size += gots * sizeof(struct got_entry); mod_mem->size = ALIGN(mod_mem->size, 16); me->arch.fdesc_offset = mod_mem->size; mod_mem->size += fdescs * sizeof(Elf_Fdesc); me->arch.got_max = gots; me->arch.fdesc_max = fdescs; return 0; } #ifdef CONFIG_64BIT static Elf64_Word get_got(struct module *me, unsigned long value, long addend) { unsigned int i; struct got_entry *got; value += addend; BUG_ON(value == 0); got = me->mem[MOD_TEXT].base + me->arch.got_offset; for (i = 0; got[i].addr; i++) if (got[i].addr == value) goto out; BUG_ON(++me->arch.got_count > me->arch.got_max); got[i].addr = value; out: pr_debug("GOT ENTRY %d[%lx] val %lx\n", i, i*sizeof(struct got_entry), value); return i * sizeof(struct got_entry); } #endif /* CONFIG_64BIT */ #ifdef CONFIG_64BIT static Elf_Addr get_fdesc(struct module *me, unsigned long value) { Elf_Fdesc *fdesc = me->mem[MOD_TEXT].base + me->arch.fdesc_offset; if (!value) { printk(KERN_ERR "%s: zero OPD requested!\n", me->name); return 0; } /* Look for existing fdesc entry. */ while (fdesc->addr) { if (fdesc->addr == value) return (Elf_Addr)fdesc; fdesc++; } BUG_ON(++me->arch.fdesc_count > me->arch.fdesc_max); /* Create new one */ fdesc->addr = value; fdesc->gp = (Elf_Addr)me->mem[MOD_TEXT].base + me->arch.got_offset; return (Elf_Addr)fdesc; } #endif /* CONFIG_64BIT */ enum elf_stub_type { ELF_STUB_GOT, ELF_STUB_MILLI, ELF_STUB_DIRECT, }; static Elf_Addr get_stub(struct module *me, unsigned long value, long addend, enum elf_stub_type stub_type, Elf_Addr loc0, unsigned int targetsec) { struct stub_entry *stub; int __maybe_unused d; /* initialize stub_offset to point in front of the section */ if (!me->arch.section[targetsec].stub_offset) { loc0 -= (me->arch.section[targetsec].stub_entries + 1) * sizeof(struct stub_entry); /* get correct alignment for the stubs */ loc0 = ALIGN(loc0, sizeof(struct stub_entry)); me->arch.section[targetsec].stub_offset = loc0; } /* get address of stub entry */ stub = (void *) me->arch.section[targetsec].stub_offset; me->arch.section[targetsec].stub_offset += sizeof(struct stub_entry); /* do not write outside available stub area */ BUG_ON(0 == me->arch.section[targetsec].stub_entries--); #ifndef CONFIG_64BIT /* for 32-bit the stub looks like this: * ldil L'XXX,%r1 * be,n R'XXX(%sr4,%r1) */ //value = *(unsigned long *)((value + addend) & ~3); /* why? */ stub->insns[0] = 0x20200000; /* ldil L'XXX,%r1 */ stub->insns[1] = 0xe0202002; /* be,n R'XXX(%sr4,%r1) */ stub->insns[0] |= reassemble_21(lrsel(value, addend)); stub->insns[1] |= reassemble_17(rrsel(value, addend) / 4); #else /* for 64-bit we have three kinds of stubs: * for normal function calls: * ldd 0(%dp),%dp * ldd 10(%dp), %r1 * bve (%r1) * ldd 18(%dp), %dp * * for millicode: * ldil 0, %r1 * ldo 0(%r1), %r1 * ldd 10(%r1), %r1 * bve,n (%r1) * * for direct branches (jumps between different section of the * same module): * ldil 0, %r1 * ldo 0(%r1), %r1 * bve,n (%r1) */ switch (stub_type) { case ELF_STUB_GOT: d = get_got(me, value, addend); if (d <= 15) { /* Format 5 */ stub->insns[0] = 0x0f6010db; /* ldd 0(%dp),%dp */ stub->insns[0] |= low_sign_unext(d, 5) << 16; } else { /* Format 3 */ stub->insns[0] = 0x537b0000; /* ldd 0(%dp),%dp */ stub->insns[0] |= reassemble_16a(d); } stub->insns[1] = 0x53610020; /* ldd 10(%dp),%r1 */ stub->insns[2] = 0xe820d000; /* bve (%r1) */ stub->insns[3] = 0x537b0030; /* ldd 18(%dp),%dp */ break; case ELF_STUB_MILLI: stub->insns[0] = 0x20200000; /* ldil 0,%r1 */ stub->insns[1] = 0x34210000; /* ldo 0(%r1), %r1 */ stub->insns[2] = 0x50210020; /* ldd 10(%r1),%r1 */ stub->insns[3] = 0xe820d002; /* bve,n (%r1) */ stub->insns[0] |= reassemble_21(lrsel(value, addend)); stub->insns[1] |= reassemble_14(rrsel(value, addend)); break; case ELF_STUB_DIRECT: stub->insns[0] = 0x20200000; /* ldil 0,%r1 */ stub->insns[1] = 0x34210000; /* ldo 0(%r1), %r1 */ stub->insns[2] = 0xe820d002; /* bve,n (%r1) */ stub->insns[0] |= reassemble_21(lrsel(value, addend)); stub->insns[1] |= reassemble_14(rrsel(value, addend)); break; } #endif return (Elf_Addr)stub; } #ifndef CONFIG_64BIT int apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab, unsigned int symindex, unsigned int relsec, struct module *me) { int i; Elf32_Rela *rel = (void *)sechdrs[relsec].sh_addr; Elf32_Sym *sym; Elf32_Word *loc; Elf32_Addr val; Elf32_Sword addend; Elf32_Addr dot; Elf_Addr loc0; unsigned int targetsec = sechdrs[relsec].sh_info; //unsigned long dp = (unsigned long)$global$; register unsigned long dp asm ("r27"); pr_debug("Applying relocate section %u to %u\n", relsec, targetsec); for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) { /* This is where to make the change */ loc = (void *)sechdrs[targetsec].sh_addr + rel[i].r_offset; /* This is the start of the target section */ loc0 = sechdrs[targetsec].sh_addr; /* This is the symbol it is referring to */ sym = (Elf32_Sym *)sechdrs[symindex].sh_addr + ELF32_R_SYM(rel[i].r_info); if (!sym->st_value) { printk(KERN_WARNING "%s: Unknown symbol %s\n", me->name, strtab + sym->st_name); return -ENOENT; } //dot = (sechdrs[relsec].sh_addr + rel->r_offset) & ~0x03; dot = (Elf32_Addr)loc & ~0x03; val = sym->st_value; addend = rel[i].r_addend; #if 0 #define r(t) ELF32_R_TYPE(rel[i].r_info)==t ? #t : pr_debug("Symbol %s loc 0x%x val 0x%x addend 0x%x: %s\n", strtab + sym->st_name, (uint32_t)loc, val, addend, r(R_PARISC_PLABEL32) r(R_PARISC_DIR32) r(R_PARISC_DIR21L) r(R_PARISC_DIR14R) r(R_PARISC_SEGREL32) r(R_PARISC_DPREL21L) r(R_PARISC_DPREL14R) r(R_PARISC_PCREL17F) r(R_PARISC_PCREL22F) "UNKNOWN"); #undef r #endif switch (ELF32_R_TYPE(rel[i].r_info)) { case R_PARISC_PLABEL32: /* 32-bit function address */ /* no function descriptors... */ *loc = fsel(val, addend); break; case R_PARISC_DIR32: /* direct 32-bit ref */ *loc = fsel(val, addend); break; case R_PARISC_DIR21L: /* left 21 bits of effective address */ val = lrsel(val, addend); *loc = mask(*loc, 21) | reassemble_21(val); break; case R_PARISC_DIR14R: /* right 14 bits of effective address */ val = rrsel(val, addend); *loc = mask(*loc, 14) | reassemble_14(val); break; case R_PARISC_SEGREL32: /* 32-bit segment relative address */ /* See note about special handling of SEGREL32 at * the beginning of this file. */ *loc = fsel(val, addend); break; case R_PARISC_SECREL32: /* 32-bit section relative address. */ *loc = fsel(val, addend); break; case R_PARISC_DPREL21L: /* left 21 bit of relative address */ val = lrsel(val - dp, addend); *loc = mask(*loc, 21) | reassemble_21(val); break; case R_PARISC_DPREL14R: /* right 14 bit of relative address */ val = rrsel(val - dp, addend); *loc = mask(*loc, 14) | reassemble_14(val); break; case R_PARISC_PCREL17F: /* 17-bit PC relative address */ /* calculate direct call offset */ val += addend; val = (val - dot - 8)/4; if (!RELOC_REACHABLE(val, 17)) { /* direct distance too far, create * stub entry instead */ val = get_stub(me, sym->st_value, addend, ELF_STUB_DIRECT, loc0, targetsec); val = (val - dot - 8)/4; CHECK_RELOC(val, 17); } *loc = (*loc & ~0x1f1ffd) | reassemble_17(val); break; case R_PARISC_PCREL22F: /* 22-bit PC relative address; only defined for pa20 */ /* calculate direct call offset */ val += addend; val = (val - dot - 8)/4; if (!RELOC_REACHABLE(val, 22)) { /* direct distance too far, create * stub entry instead */ val = get_stub(me, sym->st_value, addend, ELF_STUB_DIRECT, loc0, targetsec); val = (val - dot - 8)/4; CHECK_RELOC(val, 22); } *loc = (*loc & ~0x3ff1ffd) | reassemble_22(val); break; case R_PARISC_PCREL32: /* 32-bit PC relative address */ *loc = val - dot - 8 + addend; break; default: printk(KERN_ERR "module %s: Unknown relocation: %u\n", me->name, ELF32_R_TYPE(rel[i].r_info)); return -ENOEXEC; } } return 0; } #else int apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab, unsigned int symindex, unsigned int relsec, struct module *me) { int i; Elf64_Rela *rel = (void *)sechdrs[relsec].sh_addr; Elf64_Sym *sym; Elf64_Word *loc; Elf64_Xword *loc64; Elf64_Addr val; Elf64_Sxword addend; Elf64_Addr dot; Elf_Addr loc0; unsigned int targetsec = sechdrs[relsec].sh_info; pr_debug("Applying relocate section %u to %u\n", relsec, targetsec); for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) { /* This is where to make the change */ loc = (void *)sechdrs[targetsec].sh_addr + rel[i].r_offset; /* This is the start of the target section */ loc0 = sechdrs[targetsec].sh_addr; /* This is the symbol it is referring to */ sym = (Elf64_Sym *)sechdrs[symindex].sh_addr + ELF64_R_SYM(rel[i].r_info); if (!sym->st_value) { printk(KERN_WARNING "%s: Unknown symbol %s\n", me->name, strtab + sym->st_name); return -ENOENT; } //dot = (sechdrs[relsec].sh_addr + rel->r_offset) & ~0x03; dot = (Elf64_Addr)loc & ~0x03; loc64 = (Elf64_Xword *)loc; val = sym->st_value; addend = rel[i].r_addend; #if 0 #define r(t) ELF64_R_TYPE(rel[i].r_info)==t ? #t : printk("Symbol %s loc %p val 0x%Lx addend 0x%Lx: %s\n", strtab + sym->st_name, loc, val, addend, r(R_PARISC_LTOFF14R) r(R_PARISC_LTOFF21L) r(R_PARISC_PCREL22F) r(R_PARISC_DIR64) r(R_PARISC_SEGREL32) r(R_PARISC_FPTR64) "UNKNOWN"); #undef r #endif switch (ELF64_R_TYPE(rel[i].r_info)) { case R_PARISC_LTOFF21L: /* LT-relative; left 21 bits */ val = get_got(me, val, addend); pr_debug("LTOFF21L Symbol %s loc %p val %llx\n", strtab + sym->st_name, loc, val); val = lrsel(val, 0); *loc = mask(*loc, 21) | reassemble_21(val); break; case R_PARISC_LTOFF14R: /* L(ltoff(val+addend)) */ /* LT-relative; right 14 bits */ val = get_got(me, val, addend); val = rrsel(val, 0); pr_debug("LTOFF14R Symbol %s loc %p val %llx\n", strtab + sym->st_name, loc, val); *loc = mask(*loc, 14) | reassemble_14(val); break; case R_PARISC_PCREL22F: /* PC-relative; 22 bits */ pr_debug("PCREL22F Symbol %s loc %p val %llx\n", strtab + sym->st_name, loc, val); val += addend; /* can we reach it locally? */ if (within_module(val, me)) { /* this is the case where the symbol is local * to the module, but in a different section, * so stub the jump in case it's more than 22 * bits away */ val = (val - dot - 8)/4; if (!RELOC_REACHABLE(val, 22)) { /* direct distance too far, create * stub entry instead */ val = get_stub(me, sym->st_value, addend, ELF_STUB_DIRECT, loc0, targetsec); } else { /* Ok, we can reach it directly. */ val = sym->st_value; val += addend; } } else { val = sym->st_value; if (strncmp(strtab + sym->st_name, "$$", 2) == 0) val = get_stub(me, val, addend, ELF_STUB_MILLI, loc0, targetsec); else val = get_stub(me, val, addend, ELF_STUB_GOT, loc0, targetsec); } pr_debug("STUB FOR %s loc %px, val %llx+%llx at %llx\n", strtab + sym->st_name, loc, sym->st_value, addend, val); val = (val - dot - 8)/4; CHECK_RELOC(val, 22); *loc = (*loc & ~0x3ff1ffd) | reassemble_22(val); break; case R_PARISC_PCREL32: /* 32-bit PC relative address */ *loc = val - dot - 8 + addend; break; case R_PARISC_PCREL64: /* 64-bit PC relative address */ *loc64 = val - dot - 8 + addend; break; case R_PARISC_DIR64: /* 64-bit effective address */ *loc64 = val + addend; break; case R_PARISC_SEGREL32: /* 32-bit segment relative address */ /* See note about special handling of SEGREL32 at * the beginning of this file. */ *loc = fsel(val, addend); break; case R_PARISC_SECREL32: /* 32-bit section relative address. */ *loc = fsel(val, addend); break; case R_PARISC_FPTR64: /* 64-bit function address */ if (within_module(val + addend, me)) { *loc64 = get_fdesc(me, val+addend); pr_debug("FDESC for %s at %llx points to %llx\n", strtab + sym->st_name, *loc64, ((Elf_Fdesc *)*loc64)->addr); } else { /* if the symbol is not local to this * module then val+addend is a pointer * to the function descriptor */ pr_debug("Non local FPTR64 Symbol %s loc %p val %llx\n", strtab + sym->st_name, loc, val); *loc64 = val + addend; } break; default: printk(KERN_ERR "module %s: Unknown relocation: %Lu\n", me->name, ELF64_R_TYPE(rel[i].r_info)); return -ENOEXEC; } } return 0; } #endif static void register_unwind_table(struct module *me, const Elf_Shdr *sechdrs) { unsigned char *table, *end; unsigned long gp; if (!me->arch.unwind_section) return; table = (unsigned char *)sechdrs[me->arch.unwind_section].sh_addr; end = table + sechdrs[me->arch.unwind_section].sh_size; gp = (Elf_Addr)me->mem[MOD_TEXT].base + me->arch.got_offset; pr_debug("register_unwind_table(), sect = %d at 0x%p - 0x%p (gp=0x%lx)\n", me->arch.unwind_section, table, end, gp); me->arch.unwind = unwind_table_add(me->name, 0, gp, table, end); } static void deregister_unwind_table(struct module *me) { if (me->arch.unwind) unwind_table_remove(me->arch.unwind); } int module_finalize(const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs, struct module *me) { int i; unsigned long nsyms; const char *strtab = NULL; const Elf_Shdr *s; char *secstrings; int symindex __maybe_unused = -1; Elf_Sym *newptr, *oldptr; Elf_Shdr *symhdr = NULL; #ifdef DEBUG Elf_Fdesc *entry; u32 *addr; entry = (Elf_Fdesc *)me->init; printk("FINALIZE, ->init FPTR is %p, GP %lx ADDR %lx\n", entry, entry->gp, entry->addr); addr = (u32 *)entry->addr; printk("INSNS: %x %x %x %x\n", addr[0], addr[1], addr[2], addr[3]); printk("got entries used %ld, gots max %ld\n" "fdescs used %ld, fdescs max %ld\n", me->arch.got_count, me->arch.got_max, me->arch.fdesc_count, me->arch.fdesc_max); #endif register_unwind_table(me, sechdrs); /* haven't filled in me->symtab yet, so have to find it * ourselves */ for (i = 1; i < hdr->e_shnum; i++) { if(sechdrs[i].sh_type == SHT_SYMTAB && (sechdrs[i].sh_flags & SHF_ALLOC)) { int strindex = sechdrs[i].sh_link; symindex = i; /* FIXME: AWFUL HACK * The cast is to drop the const from * the sechdrs pointer */ symhdr = (Elf_Shdr *)&sechdrs[i]; strtab = (char *)sechdrs[strindex].sh_addr; break; } } pr_debug("module %s: strtab %p, symhdr %p\n", me->name, strtab, symhdr); if(me->arch.got_count > MAX_GOTS) { printk(KERN_ERR "%s: Global Offset Table overflow (used %ld, allowed %d)\n", me->name, me->arch.got_count, MAX_GOTS); return -EINVAL; } kfree(me->arch.section); me->arch.section = NULL; /* no symbol table */ if(symhdr == NULL) return 0; oldptr = (void *)symhdr->sh_addr; newptr = oldptr + 1; /* we start counting at 1 */ nsyms = symhdr->sh_size / sizeof(Elf_Sym); pr_debug("OLD num_symtab %lu\n", nsyms); for (i = 1; i < nsyms; i++) { oldptr++; /* note, count starts at 1 so preincrement */ if(strncmp(strtab + oldptr->st_name, ".L", 2) == 0) continue; if(newptr != oldptr) *newptr++ = *oldptr; else newptr++; } nsyms = newptr - (Elf_Sym *)symhdr->sh_addr; pr_debug("NEW num_symtab %lu\n", nsyms); symhdr->sh_size = nsyms * sizeof(Elf_Sym); /* find .altinstructions section */ secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset; for (s = sechdrs; s < sechdrs + hdr->e_shnum; s++) { void *aseg = (void *) s->sh_addr; char *secname = secstrings + s->sh_name; if (!strcmp(".altinstructions", secname)) /* patch .altinstructions */ apply_alternatives(aseg, aseg + s->sh_size, me->name); #ifdef CONFIG_DYNAMIC_FTRACE /* For 32 bit kernels we're compiling modules with * -ffunction-sections so we must relocate the addresses in the * ftrace callsite section. */ if (symindex != -1 && !strcmp(secname, FTRACE_CALLSITE_SECTION)) { int err; if (s->sh_type == SHT_REL) err = apply_relocate((Elf_Shdr *)sechdrs, strtab, symindex, s - sechdrs, me); else if (s->sh_type == SHT_RELA) err = apply_relocate_add((Elf_Shdr *)sechdrs, strtab, symindex, s - sechdrs, me); if (err) return err; } #endif } return 0; } void module_arch_cleanup(struct module *mod) { deregister_unwind_table(mod); } #ifdef CONFIG_64BIT void *dereference_module_function_descriptor(struct module *mod, void *ptr) { unsigned long start_opd = (Elf64_Addr)mod->mem[MOD_TEXT].base + mod->arch.fdesc_offset; unsigned long end_opd = start_opd + mod->arch.fdesc_count * sizeof(Elf64_Fdesc); if (ptr < (void *)start_opd || ptr >= (void *)end_opd) return ptr; return dereference_function_descriptor(ptr); } #endif |