arch/parisc/kernel/module.c

/* [<][>][^][v][top][bottom][index][help] */
This source file includes following definitions.
in_init
in_core
in_local
sign_unext
low_sign_unext
reassemble_14
reassemble_16a
reassemble_17
reassemble_21
reassemble_22
module_alloc
count_gots
count_fdescs
count_stubs
count_gots
count_fdescs
count_stubs
module_arch_freeing_init
arch_mod_section_prepend
module_frob_arch_sections
get_got
get_fdesc
get_stub
apply_relocate_add
apply_relocate_add
register_unwind_table
deregister_unwind_table
module_finalize
module_arch_cleanup
dereference_module_function_descriptor
   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*    Kernel dynamically loadable module help for PARISC.
   3  *
   4  *    The best reference for this stuff is probably the Processor-
   5  *    Specific ELF Supplement for PA-RISC:
   6  *        http://ftp.parisc-linux.org/docs/arch/elf-pa-hp.pdf
   7  *
   8  *    Linux/PA-RISC Project (http://www.parisc-linux.org/)
   9  *    Copyright (C) 2003 Randolph Chung <tausq at debian . org>
  10  *    Copyright (C) 2008 Helge Deller <deller@gmx.de>
  11  *
  12  *    Notes:
  13  *    - PLT stub handling
  14  *      On 32bit (and sometimes 64bit) and with big kernel modules like xfs or
  15  *      ipv6 the relocation types R_PARISC_PCREL17F and R_PARISC_PCREL22F may
  16  *      fail to reach their PLT stub if we only create one big stub array for
  17  *      all sections at the beginning of the core or init section.
  18  *      Instead we now insert individual PLT stub entries directly in front of
  19  *      of the code sections where the stubs are actually called.
  20  *      This reduces the distance between the PCREL location and the stub entry
  21  *      so that the relocations can be fulfilled.
  22  *      While calculating the final layout of the kernel module in memory, the
  23  *      kernel module loader calls arch_mod_section_prepend() to request the
  24  *      to be reserved amount of memory in front of each individual section.
  25  *
  26  *    - SEGREL32 handling
  27  *      We are not doing SEGREL32 handling correctly. According to the ABI, we
  28  *      should do a value offset, like this:
  29  *                      if (in_init(me, (void *)val))
  30  *                              val -= (uint32_t)me->init_layout.base;
  31  *                      else
  32  *                              val -= (uint32_t)me->core_layout.base;
  33  *      However, SEGREL32 is used only for PARISC unwind entries, and we want
  34  *      those entries to have an absolute address, and not just an offset.
  35  *
  36  *      The unwind table mechanism has the ability to specify an offset for
  37  *      the unwind table; however, because we split off the init functions into
  38  *      a different piece of memory, it is not possible to do this using a
  39  *      single offset. Instead, we use the above hack for now.
  40  */
  41 
  42 #include <linux/moduleloader.h>
  43 #include <linux/elf.h>
  44 #include <linux/vmalloc.h>
  45 #include <linux/fs.h>
  46 #include <linux/string.h>
  47 #include <linux/kernel.h>
  48 #include <linux/bug.h>
  49 #include <linux/mm.h>
  50 #include <linux/slab.h>
  51 
  52 #include <asm/pgtable.h>
  53 #include <asm/unwind.h>
  54 #include <asm/sections.h>
  55 
  56 #define RELOC_REACHABLE(val, bits) \
  57         (( ( !((val) & (1<<((bits)-1))) && ((val)>>(bits)) != 0 )  ||   \
  58              ( ((val) & (1<<((bits)-1))) && ((val)>>(bits)) != (((__typeof__(val))(~0))>>((bits)+2)))) ? \
  59         0 : 1)
  60 
  61 #define CHECK_RELOC(val, bits) \
  62         if (!RELOC_REACHABLE(val, bits)) { \
  63                 printk(KERN_ERR "module %s relocation of symbol %s is out of range (0x%lx in %d bits)\n", \
  64                 me->name, strtab + sym->st_name, (unsigned long)val, bits); \
  65                 return -ENOEXEC;                        \
  66         }
  67 
  68 /* Maximum number of GOT entries. We use a long displacement ldd from
  69  * the bottom of the table, which has a maximum signed displacement of
  70  * 0x3fff; however, since we're only going forward, this becomes
  71  * 0x1fff, and thus, since each GOT entry is 8 bytes long we can have
  72  * at most 1023 entries.
  73  * To overcome this 14bit displacement with some kernel modules, we'll
  74  * use instead the unusal 16bit displacement method (see reassemble_16a)
  75  * which gives us a maximum positive displacement of 0x7fff, and as such
  76  * allows us to allocate up to 4095 GOT entries. */
  77 #define MAX_GOTS        4095
  78 
  79 /* three functions to determine where in the module core
  80  * or init pieces the location is */
  81 static inline int in_init(struct module *me, void *loc)
  82 {
  83         return (loc >= me->init_layout.base &&
  84                 loc <= (me->init_layout.base + me->init_layout.size));
  85 }
  86 
  87 static inline int in_core(struct module *me, void *loc)
  88 {
  89         return (loc >= me->core_layout.base &&
  90                 loc <= (me->core_layout.base + me->core_layout.size));
  91 }
  92 
  93 static inline int in_local(struct module *me, void *loc)
  94 {
  95         return in_init(me, loc) || in_core(me, loc);
  96 }
  97 
  98 #ifndef CONFIG_64BIT
  99 struct got_entry {
 100         Elf32_Addr addr;
 101 };
 102 
 103 struct stub_entry {
 104         Elf32_Word insns[2]; /* each stub entry has two insns */
 105 };
 106 #else
 107 struct got_entry {
 108         Elf64_Addr addr;
 109 };
 110 
 111 struct stub_entry {
 112         Elf64_Word insns[4]; /* each stub entry has four insns */
 113 };
 114 #endif
 115 
 116 /* Field selection types defined by hppa */
 117 #define rnd(x)                  (((x)+0x1000)&~0x1fff)
 118 /* fsel: full 32 bits */
 119 #define fsel(v,a)               ((v)+(a))
 120 /* lsel: select left 21 bits */
 121 #define lsel(v,a)               (((v)+(a))>>11)
 122 /* rsel: select right 11 bits */
 123 #define rsel(v,a)               (((v)+(a))&0x7ff)
 124 /* lrsel with rounding of addend to nearest 8k */
 125 #define lrsel(v,a)              (((v)+rnd(a))>>11)
 126 /* rrsel with rounding of addend to nearest 8k */
 127 #define rrsel(v,a)              ((((v)+rnd(a))&0x7ff)+((a)-rnd(a)))
 128 
 129 #define mask(x,sz)              ((x) & ~((1<<(sz))-1))
 130 
 131 
 132 /* The reassemble_* functions prepare an immediate value for
 133    insertion into an opcode. pa-risc uses all sorts of weird bitfields
 134    in the instruction to hold the value.  */
 135 static inline int sign_unext(int x, int len)
 136 {
 137         int len_ones;
 138 
 139         len_ones = (1 << len) - 1;
 140         return x & len_ones;
 141 }
 142 
 143 static inline int low_sign_unext(int x, int len)
 144 {
 145         int sign, temp;
 146 
 147         sign = (x >> (len-1)) & 1;
 148         temp = sign_unext(x, len-1);
 149         return (temp << 1) | sign;
 150 }
 151 
 152 static inline int reassemble_14(int as14)
 153 {
 154         return (((as14 & 0x1fff) << 1) |
 155                 ((as14 & 0x2000) >> 13));
 156 }
 157 
 158 static inline int reassemble_16a(int as16)
 159 {
 160         int s, t;
 161 
 162         /* Unusual 16-bit encoding, for wide mode only.  */
 163         t = (as16 << 1) & 0xffff;
 164         s = (as16 & 0x8000);
 165         return (t ^ s ^ (s >> 1)) | (s >> 15);
 166 }
 167 
 168 
 169 static inline int reassemble_17(int as17)
 170 {
 171         return (((as17 & 0x10000) >> 16) |
 172                 ((as17 & 0x0f800) << 5) |
 173                 ((as17 & 0x00400) >> 8) |
 174                 ((as17 & 0x003ff) << 3));
 175 }
 176 
 177 static inline int reassemble_21(int as21)
 178 {
 179         return (((as21 & 0x100000) >> 20) |
 180                 ((as21 & 0x0ffe00) >> 8) |
 181                 ((as21 & 0x000180) << 7) |
 182                 ((as21 & 0x00007c) << 14) |
 183                 ((as21 & 0x000003) << 12));
 184 }
 185 
 186 static inline int reassemble_22(int as22)
 187 {
 188         return (((as22 & 0x200000) >> 21) |
 189                 ((as22 & 0x1f0000) << 5) |
 190                 ((as22 & 0x00f800) << 5) |
 191                 ((as22 & 0x000400) >> 8) |
 192                 ((as22 & 0x0003ff) << 3));
 193 }
 194 
 195 void *module_alloc(unsigned long size)
 196 {
 197         /* using RWX means less protection for modules, but it's
 198          * easier than trying to map the text, data, init_text and
 199          * init_data correctly */
 200         return __vmalloc_node_range(size, 1, VMALLOC_START, VMALLOC_END,
 201                                     GFP_KERNEL,
 202                                     PAGE_KERNEL_RWX, 0, NUMA_NO_NODE,
 203                                     __builtin_return_address(0));
 204 }
 205 
 206 #ifndef CONFIG_64BIT
 207 static inline unsigned long count_gots(const Elf_Rela *rela, unsigned long n)
 208 {
 209         return 0;
 210 }
 211 
 212 static inline unsigned long count_fdescs(const Elf_Rela *rela, unsigned long n)
 213 {
 214         return 0;
 215 }
 216 
 217 static inline unsigned long count_stubs(const Elf_Rela *rela, unsigned long n)
 218 {
 219         unsigned long cnt = 0;
 220 
 221         for (; n > 0; n--, rela++)
 222         {
 223                 switch (ELF32_R_TYPE(rela->r_info)) {
 224                         case R_PARISC_PCREL17F:
 225                         case R_PARISC_PCREL22F:
 226                                 cnt++;
 227                 }
 228         }
 229 
 230         return cnt;
 231 }
 232 #else
 233 static inline unsigned long count_gots(const Elf_Rela *rela, unsigned long n)
 234 {
 235         unsigned long cnt = 0;
 236 
 237         for (; n > 0; n--, rela++)
 238         {
 239                 switch (ELF64_R_TYPE(rela->r_info)) {
 240                         case R_PARISC_LTOFF21L:
 241                         case R_PARISC_LTOFF14R:
 242                         case R_PARISC_PCREL22F:
 243                                 cnt++;
 244                 }
 245         }
 246 
 247         return cnt;
 248 }
 249 
 250 static inline unsigned long count_fdescs(const Elf_Rela *rela, unsigned long n)
 251 {
 252         unsigned long cnt = 0;
 253 
 254         for (; n > 0; n--, rela++)
 255         {
 256                 switch (ELF64_R_TYPE(rela->r_info)) {
 257                         case R_PARISC_FPTR64:
 258                                 cnt++;
 259                 }
 260         }
 261 
 262         return cnt;
 263 }
 264 
 265 static inline unsigned long count_stubs(const Elf_Rela *rela, unsigned long n)
 266 {
 267         unsigned long cnt = 0;
 268 
 269         for (; n > 0; n--, rela++)
 270         {
 271                 switch (ELF64_R_TYPE(rela->r_info)) {
 272                         case R_PARISC_PCREL22F:
 273                                 cnt++;
 274                 }
 275         }
 276 
 277         return cnt;
 278 }
 279 #endif
 280 
 281 void module_arch_freeing_init(struct module *mod)
 282 {
 283         kfree(mod->arch.section);
 284         mod->arch.section = NULL;
 285 }
 286 
 287 /* Additional bytes needed in front of individual sections */
 288 unsigned int arch_mod_section_prepend(struct module *mod,
 289                                       unsigned int section)
 290 {
 291         /* size needed for all stubs of this section (including
 292          * one additional for correct alignment of the stubs) */
 293         return (mod->arch.section[section].stub_entries + 1)
 294                 * sizeof(struct stub_entry);
 295 }
 296 
 297 #define CONST
 298 int module_frob_arch_sections(CONST Elf_Ehdr *hdr,
 299                               CONST Elf_Shdr *sechdrs,
 300                               CONST char *secstrings,
 301                               struct module *me)
 302 {
 303         unsigned long gots = 0, fdescs = 0, len;
 304         unsigned int i;
 305 
 306         len = hdr->e_shnum * sizeof(me->arch.section[0]);
 307         me->arch.section = kzalloc(len, GFP_KERNEL);
 308         if (!me->arch.section)
 309                 return -ENOMEM;
 310 
 311         for (i = 1; i < hdr->e_shnum; i++) {
 312                 const Elf_Rela *rels = (void *)sechdrs[i].sh_addr;
 313                 unsigned long nrels = sechdrs[i].sh_size / sizeof(*rels);
 314                 unsigned int count, s;
 315 
 316                 if (strncmp(secstrings + sechdrs[i].sh_name,
 317                             ".PARISC.unwind", 14) == 0)
 318                         me->arch.unwind_section = i;
 319 
 320                 if (sechdrs[i].sh_type != SHT_RELA)
 321                         continue;
 322 
 323                 /* some of these are not relevant for 32-bit/64-bit
 324                  * we leave them here to make the code common. the
 325                  * compiler will do its thing and optimize out the
 326                  * stuff we don't need
 327                  */
 328                 gots += count_gots(rels, nrels);
 329                 fdescs += count_fdescs(rels, nrels);
 330 
 331                 /* XXX: By sorting the relocs and finding duplicate entries
 332                  *  we could reduce the number of necessary stubs and save
 333                  *  some memory. */
 334                 count = count_stubs(rels, nrels);
 335                 if (!count)
 336                         continue;
 337 
 338                 /* so we need relocation stubs. reserve necessary memory. */
 339                 /* sh_info gives the section for which we need to add stubs. */
 340                 s = sechdrs[i].sh_info;
 341 
 342                 /* each code section should only have one relocation section */
 343                 WARN_ON(me->arch.section[s].stub_entries);
 344 
 345                 /* store number of stubs we need for this section */
 346                 me->arch.section[s].stub_entries += count;
 347         }
 348 
 349         /* align things a bit */
 350         me->core_layout.size = ALIGN(me->core_layout.size, 16);
 351         me->arch.got_offset = me->core_layout.size;
 352         me->core_layout.size += gots * sizeof(struct got_entry);
 353 
 354         me->core_layout.size = ALIGN(me->core_layout.size, 16);
 355         me->arch.fdesc_offset = me->core_layout.size;
 356         me->core_layout.size += fdescs * sizeof(Elf_Fdesc);
 357 
 358         me->arch.got_max = gots;
 359         me->arch.fdesc_max = fdescs;
 360 
 361         return 0;
 362 }
 363 
 364 #ifdef CONFIG_64BIT
 365 static Elf64_Word get_got(struct module *me, unsigned long value, long addend)
 366 {
 367         unsigned int i;
 368         struct got_entry *got;
 369 
 370         value += addend;
 371 
 372         BUG_ON(value == 0);
 373 
 374         got = me->core_layout.base + me->arch.got_offset;
 375         for (i = 0; got[i].addr; i++)
 376                 if (got[i].addr == value)
 377                         goto out;
 378 
 379         BUG_ON(++me->arch.got_count > me->arch.got_max);
 380 
 381         got[i].addr = value;
 382  out:
 383         pr_debug("GOT ENTRY %d[%lx] val %lx\n", i, i*sizeof(struct got_entry),
 384                value);
 385         return i * sizeof(struct got_entry);
 386 }
 387 #endif /* CONFIG_64BIT */
 388 
 389 #ifdef CONFIG_64BIT
 390 static Elf_Addr get_fdesc(struct module *me, unsigned long value)
 391 {
 392         Elf_Fdesc *fdesc = me->core_layout.base + me->arch.fdesc_offset;
 393 
 394         if (!value) {
 395                 printk(KERN_ERR "%s: zero OPD requested!\n", me->name);
 396                 return 0;
 397         }
 398 
 399         /* Look for existing fdesc entry. */
 400         while (fdesc->addr) {
 401                 if (fdesc->addr == value)
 402                         return (Elf_Addr)fdesc;
 403                 fdesc++;
 404         }
 405 
 406         BUG_ON(++me->arch.fdesc_count > me->arch.fdesc_max);
 407 
 408         /* Create new one */
 409         fdesc->addr = value;
 410         fdesc->gp = (Elf_Addr)me->core_layout.base + me->arch.got_offset;
 411         return (Elf_Addr)fdesc;
 412 }
 413 #endif /* CONFIG_64BIT */
 414 
 415 enum elf_stub_type {
 416         ELF_STUB_GOT,
 417         ELF_STUB_MILLI,
 418         ELF_STUB_DIRECT,
 419 };
 420 
 421 static Elf_Addr get_stub(struct module *me, unsigned long value, long addend,
 422         enum elf_stub_type stub_type, Elf_Addr loc0, unsigned int targetsec)
 423 {
 424         struct stub_entry *stub;
 425         int __maybe_unused d;
 426 
 427         /* initialize stub_offset to point in front of the section */
 428         if (!me->arch.section[targetsec].stub_offset) {
 429                 loc0 -= (me->arch.section[targetsec].stub_entries + 1) *
 430                                 sizeof(struct stub_entry);
 431                 /* get correct alignment for the stubs */
 432                 loc0 = ALIGN(loc0, sizeof(struct stub_entry));
 433                 me->arch.section[targetsec].stub_offset = loc0;
 434         }
 435 
 436         /* get address of stub entry */
 437         stub = (void *) me->arch.section[targetsec].stub_offset;
 438         me->arch.section[targetsec].stub_offset += sizeof(struct stub_entry);
 439 
 440         /* do not write outside available stub area */
 441         BUG_ON(0 == me->arch.section[targetsec].stub_entries--);
 442 
 443 
 444 #ifndef CONFIG_64BIT
 445 /* for 32-bit the stub looks like this:
 446  *      ldil L'XXX,%r1
 447  *      be,n R'XXX(%sr4,%r1)
 448  */
 449         //value = *(unsigned long *)((value + addend) & ~3); /* why? */
 450 
 451         stub->insns[0] = 0x20200000;    /* ldil L'XXX,%r1       */
 452         stub->insns[1] = 0xe0202002;    /* be,n R'XXX(%sr4,%r1) */
 453 
 454         stub->insns[0] |= reassemble_21(lrsel(value, addend));
 455         stub->insns[1] |= reassemble_17(rrsel(value, addend) / 4);
 456 
 457 #else
 458 /* for 64-bit we have three kinds of stubs:
 459  * for normal function calls:
 460  *      ldd 0(%dp),%dp
 461  *      ldd 10(%dp), %r1
 462  *      bve (%r1)
 463  *      ldd 18(%dp), %dp
 464  *
 465  * for millicode:
 466  *      ldil 0, %r1
 467  *      ldo 0(%r1), %r1
 468  *      ldd 10(%r1), %r1
 469  *      bve,n (%r1)
 470  *
 471  * for direct branches (jumps between different section of the
 472  * same module):
 473  *      ldil 0, %r1
 474  *      ldo 0(%r1), %r1
 475  *      bve,n (%r1)
 476  */
 477         switch (stub_type) {
 478         case ELF_STUB_GOT:
 479                 d = get_got(me, value, addend);
 480                 if (d <= 15) {
 481                         /* Format 5 */
 482                         stub->insns[0] = 0x0f6010db; /* ldd 0(%dp),%dp  */
 483                         stub->insns[0] |= low_sign_unext(d, 5) << 16;
 484                 } else {
 485                         /* Format 3 */
 486                         stub->insns[0] = 0x537b0000; /* ldd 0(%dp),%dp  */
 487                         stub->insns[0] |= reassemble_16a(d);
 488                 }
 489                 stub->insns[1] = 0x53610020;    /* ldd 10(%dp),%r1      */
 490                 stub->insns[2] = 0xe820d000;    /* bve (%r1)            */
 491                 stub->insns[3] = 0x537b0030;    /* ldd 18(%dp),%dp      */
 492                 break;
 493         case ELF_STUB_MILLI:
 494                 stub->insns[0] = 0x20200000;    /* ldil 0,%r1           */
 495                 stub->insns[1] = 0x34210000;    /* ldo 0(%r1), %r1      */
 496                 stub->insns[2] = 0x50210020;    /* ldd 10(%r1),%r1      */
 497                 stub->insns[3] = 0xe820d002;    /* bve,n (%r1)          */
 498 
 499                 stub->insns[0] |= reassemble_21(lrsel(value, addend));
 500                 stub->insns[1] |= reassemble_14(rrsel(value, addend));
 501                 break;
 502         case ELF_STUB_DIRECT:
 503                 stub->insns[0] = 0x20200000;    /* ldil 0,%r1           */
 504                 stub->insns[1] = 0x34210000;    /* ldo 0(%r1), %r1      */
 505                 stub->insns[2] = 0xe820d002;    /* bve,n (%r1)          */
 506 
 507                 stub->insns[0] |= reassemble_21(lrsel(value, addend));
 508                 stub->insns[1] |= reassemble_14(rrsel(value, addend));
 509                 break;
 510         }
 511 
 512 #endif
 513 
 514         return (Elf_Addr)stub;
 515 }
 516 
 517 #ifndef CONFIG_64BIT
 518 int apply_relocate_add(Elf_Shdr *sechdrs,
 519                        const char *strtab,
 520                        unsigned int symindex,
 521                        unsigned int relsec,
 522                        struct module *me)
 523 {
 524         int i;
 525         Elf32_Rela *rel = (void *)sechdrs[relsec].sh_addr;
 526         Elf32_Sym *sym;
 527         Elf32_Word *loc;
 528         Elf32_Addr val;
 529         Elf32_Sword addend;
 530         Elf32_Addr dot;
 531         Elf_Addr loc0;
 532         unsigned int targetsec = sechdrs[relsec].sh_info;
 533         //unsigned long dp = (unsigned long)$global$;
 534         register unsigned long dp asm ("r27");
 535 
 536         pr_debug("Applying relocate section %u to %u\n", relsec,
 537                targetsec);
 538         for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
 539                 /* This is where to make the change */
 540                 loc = (void *)sechdrs[targetsec].sh_addr
 541                       + rel[i].r_offset;
 542                 /* This is the start of the target section */
 543                 loc0 = sechdrs[targetsec].sh_addr;
 544                 /* This is the symbol it is referring to */
 545                 sym = (Elf32_Sym *)sechdrs[symindex].sh_addr
 546                         + ELF32_R_SYM(rel[i].r_info);
 547                 if (!sym->st_value) {
 548                         printk(KERN_WARNING "%s: Unknown symbol %s\n",
 549                                me->name, strtab + sym->st_name);
 550                         return -ENOENT;
 551                 }
 552                 //dot = (sechdrs[relsec].sh_addr + rel->r_offset) & ~0x03;
 553                 dot =  (Elf32_Addr)loc & ~0x03;
 554 
 555                 val = sym->st_value;
 556                 addend = rel[i].r_addend;
 557 
 558 #if 0
 559 #define r(t) ELF32_R_TYPE(rel[i].r_info)==t ? #t :
 560                 pr_debug("Symbol %s loc 0x%x val 0x%x addend 0x%x: %s\n",
 561                         strtab + sym->st_name,
 562                         (uint32_t)loc, val, addend,
 563                         r(R_PARISC_PLABEL32)
 564                         r(R_PARISC_DIR32)
 565                         r(R_PARISC_DIR21L)
 566                         r(R_PARISC_DIR14R)
 567                         r(R_PARISC_SEGREL32)
 568                         r(R_PARISC_DPREL21L)
 569                         r(R_PARISC_DPREL14R)
 570                         r(R_PARISC_PCREL17F)
 571                         r(R_PARISC_PCREL22F)
 572                         "UNKNOWN");
 573 #undef r
 574 #endif
 575 
 576                 switch (ELF32_R_TYPE(rel[i].r_info)) {
 577                 case R_PARISC_PLABEL32:
 578                         /* 32-bit function address */
 579                         /* no function descriptors... */
 580                         *loc = fsel(val, addend);
 581                         break;
 582                 case R_PARISC_DIR32:
 583                         /* direct 32-bit ref */
 584                         *loc = fsel(val, addend);
 585                         break;
 586                 case R_PARISC_DIR21L:
 587                         /* left 21 bits of effective address */
 588                         val = lrsel(val, addend);
 589                         *loc = mask(*loc, 21) | reassemble_21(val);
 590                         break;
 591                 case R_PARISC_DIR14R:
 592                         /* right 14 bits of effective address */
 593                         val = rrsel(val, addend);
 594                         *loc = mask(*loc, 14) | reassemble_14(val);
 595                         break;
 596                 case R_PARISC_SEGREL32:
 597                         /* 32-bit segment relative address */
 598                         /* See note about special handling of SEGREL32 at
 599                          * the beginning of this file.
 600                          */
 601                         *loc = fsel(val, addend);
 602                         break;
 603                 case R_PARISC_SECREL32:
 604                         /* 32-bit section relative address. */
 605                         *loc = fsel(val, addend);
 606                         break;
 607                 case R_PARISC_DPREL21L:
 608                         /* left 21 bit of relative address */
 609                         val = lrsel(val - dp, addend);
 610                         *loc = mask(*loc, 21) | reassemble_21(val);
 611                         break;
 612                 case R_PARISC_DPREL14R:
 613                         /* right 14 bit of relative address */
 614                         val = rrsel(val - dp, addend);
 615                         *loc = mask(*loc, 14) | reassemble_14(val);
 616                         break;
 617                 case R_PARISC_PCREL17F:
 618                         /* 17-bit PC relative address */
 619                         /* calculate direct call offset */
 620                         val += addend;
 621                         val = (val - dot - 8)/4;
 622                         if (!RELOC_REACHABLE(val, 17)) {
 623                                 /* direct distance too far, create
 624                                  * stub entry instead */
 625                                 val = get_stub(me, sym->st_value, addend,
 626                                         ELF_STUB_DIRECT, loc0, targetsec);
 627                                 val = (val - dot - 8)/4;
 628                                 CHECK_RELOC(val, 17);
 629                         }
 630                         *loc = (*loc & ~0x1f1ffd) | reassemble_17(val);
 631                         break;
 632                 case R_PARISC_PCREL22F:
 633                         /* 22-bit PC relative address; only defined for pa20 */
 634                         /* calculate direct call offset */
 635                         val += addend;
 636                         val = (val - dot - 8)/4;
 637                         if (!RELOC_REACHABLE(val, 22)) {
 638                                 /* direct distance too far, create
 639                                  * stub entry instead */
 640                                 val = get_stub(me, sym->st_value, addend,
 641                                         ELF_STUB_DIRECT, loc0, targetsec);
 642                                 val = (val - dot - 8)/4;
 643                                 CHECK_RELOC(val, 22);
 644                         }
 645                         *loc = (*loc & ~0x3ff1ffd) | reassemble_22(val);
 646                         break;
 647                 case R_PARISC_PCREL32:
 648                         /* 32-bit PC relative address */
 649                         *loc = val - dot - 8 + addend;
 650                         break;
 651 
 652                 default:
 653                         printk(KERN_ERR "module %s: Unknown relocation: %u\n",
 654                                me->name, ELF32_R_TYPE(rel[i].r_info));
 655                         return -ENOEXEC;
 656                 }
 657         }
 658 
 659         return 0;
 660 }
 661 
 662 #else
 663 int apply_relocate_add(Elf_Shdr *sechdrs,
 664                        const char *strtab,
 665                        unsigned int symindex,
 666                        unsigned int relsec,
 667                        struct module *me)
 668 {
 669         int i;
 670         Elf64_Rela *rel = (void *)sechdrs[relsec].sh_addr;
 671         Elf64_Sym *sym;
 672         Elf64_Word *loc;
 673         Elf64_Xword *loc64;
 674         Elf64_Addr val;
 675         Elf64_Sxword addend;
 676         Elf64_Addr dot;
 677         Elf_Addr loc0;
 678         unsigned int targetsec = sechdrs[relsec].sh_info;
 679 
 680         pr_debug("Applying relocate section %u to %u\n", relsec,
 681                targetsec);
 682         for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
 683                 /* This is where to make the change */
 684                 loc = (void *)sechdrs[targetsec].sh_addr
 685                       + rel[i].r_offset;
 686                 /* This is the start of the target section */
 687                 loc0 = sechdrs[targetsec].sh_addr;
 688                 /* This is the symbol it is referring to */
 689                 sym = (Elf64_Sym *)sechdrs[symindex].sh_addr
 690                         + ELF64_R_SYM(rel[i].r_info);
 691                 if (!sym->st_value) {
 692                         printk(KERN_WARNING "%s: Unknown symbol %s\n",
 693                                me->name, strtab + sym->st_name);
 694                         return -ENOENT;
 695                 }
 696                 //dot = (sechdrs[relsec].sh_addr + rel->r_offset) & ~0x03;
 697                 dot = (Elf64_Addr)loc & ~0x03;
 698                 loc64 = (Elf64_Xword *)loc;
 699 
 700                 val = sym->st_value;
 701                 addend = rel[i].r_addend;
 702 
 703 #if 0
 704 #define r(t) ELF64_R_TYPE(rel[i].r_info)==t ? #t :
 705                 printk("Symbol %s loc %p val 0x%Lx addend 0x%Lx: %s\n",
 706                         strtab + sym->st_name,
 707                         loc, val, addend,
 708                         r(R_PARISC_LTOFF14R)
 709                         r(R_PARISC_LTOFF21L)
 710                         r(R_PARISC_PCREL22F)
 711                         r(R_PARISC_DIR64)
 712                         r(R_PARISC_SEGREL32)
 713                         r(R_PARISC_FPTR64)
 714                         "UNKNOWN");
 715 #undef r
 716 #endif
 717 
 718                 switch (ELF64_R_TYPE(rel[i].r_info)) {
 719                 case R_PARISC_LTOFF21L:
 720                         /* LT-relative; left 21 bits */
 721                         val = get_got(me, val, addend);
 722                         pr_debug("LTOFF21L Symbol %s loc %p val %llx\n",
 723                                strtab + sym->st_name,
 724                                loc, val);
 725                         val = lrsel(val, 0);
 726                         *loc = mask(*loc, 21) | reassemble_21(val);
 727                         break;
 728                 case R_PARISC_LTOFF14R:
 729                         /* L(ltoff(val+addend)) */
 730                         /* LT-relative; right 14 bits */
 731                         val = get_got(me, val, addend);
 732                         val = rrsel(val, 0);
 733                         pr_debug("LTOFF14R Symbol %s loc %p val %llx\n",
 734                                strtab + sym->st_name,
 735                                loc, val);
 736                         *loc = mask(*loc, 14) | reassemble_14(val);
 737                         break;
 738                 case R_PARISC_PCREL22F:
 739                         /* PC-relative; 22 bits */
 740                         pr_debug("PCREL22F Symbol %s loc %p val %llx\n",
 741                                strtab + sym->st_name,
 742                                loc, val);
 743                         val += addend;
 744                         /* can we reach it locally? */
 745                         if (in_local(me, (void *)val)) {
 746                                 /* this is the case where the symbol is local
 747                                  * to the module, but in a different section,
 748                                  * so stub the jump in case it's more than 22
 749                                  * bits away */
 750                                 val = (val - dot - 8)/4;
 751                                 if (!RELOC_REACHABLE(val, 22)) {
 752                                         /* direct distance too far, create
 753                                          * stub entry instead */
 754                                         val = get_stub(me, sym->st_value,
 755                                                 addend, ELF_STUB_DIRECT,
 756                                                 loc0, targetsec);
 757                                 } else {
 758                                         /* Ok, we can reach it directly. */
 759                                         val = sym->st_value;
 760                                         val += addend;
 761                                 }
 762                         } else {
 763                                 val = sym->st_value;
 764                                 if (strncmp(strtab + sym->st_name, "$$", 2)
 765                                     == 0)
 766                                         val = get_stub(me, val, addend, ELF_STUB_MILLI,
 767                                                        loc0, targetsec);
 768                                 else
 769                                         val = get_stub(me, val, addend, ELF_STUB_GOT,
 770                                                        loc0, targetsec);
 771                         }
 772                         pr_debug("STUB FOR %s loc %px, val %llx+%llx at %llx\n",
 773                                strtab + sym->st_name, loc, sym->st_value,
 774                                addend, val);
 775                         val = (val - dot - 8)/4;
 776                         CHECK_RELOC(val, 22);
 777                         *loc = (*loc & ~0x3ff1ffd) | reassemble_22(val);
 778                         break;
 779                 case R_PARISC_PCREL32:
 780                         /* 32-bit PC relative address */
 781                         *loc = val - dot - 8 + addend;
 782                         break;
 783                 case R_PARISC_PCREL64:
 784                         /* 64-bit PC relative address */
 785                         *loc64 = val - dot - 8 + addend;
 786                         break;
 787                 case R_PARISC_DIR64:
 788                         /* 64-bit effective address */
 789                         *loc64 = val + addend;
 790                         break;
 791                 case R_PARISC_SEGREL32:
 792                         /* 32-bit segment relative address */
 793                         /* See note about special handling of SEGREL32 at
 794                          * the beginning of this file.
 795                          */
 796                         *loc = fsel(val, addend);
 797                         break;
 798                 case R_PARISC_SECREL32:
 799                         /* 32-bit section relative address. */
 800                         *loc = fsel(val, addend);
 801                         break;
 802                 case R_PARISC_FPTR64:
 803                         /* 64-bit function address */
 804                         if(in_local(me, (void *)(val + addend))) {
 805                                 *loc64 = get_fdesc(me, val+addend);
 806                                 pr_debug("FDESC for %s at %llx points to %llx\n",
 807                                        strtab + sym->st_name, *loc64,
 808                                        ((Elf_Fdesc *)*loc64)->addr);
 809                         } else {
 810                                 /* if the symbol is not local to this
 811                                  * module then val+addend is a pointer
 812                                  * to the function descriptor */
 813                                 pr_debug("Non local FPTR64 Symbol %s loc %p val %llx\n",
 814                                        strtab + sym->st_name,
 815                                        loc, val);
 816                                 *loc64 = val + addend;
 817                         }
 818                         break;
 819 
 820                 default:
 821                         printk(KERN_ERR "module %s: Unknown relocation: %Lu\n",
 822                                me->name, ELF64_R_TYPE(rel[i].r_info));
 823                         return -ENOEXEC;
 824                 }
 825         }
 826         return 0;
 827 }
 828 #endif
 829 
 830 static void
 831 register_unwind_table(struct module *me,
 832                       const Elf_Shdr *sechdrs)
 833 {
 834         unsigned char *table, *end;
 835         unsigned long gp;
 836 
 837         if (!me->arch.unwind_section)
 838                 return;
 839 
 840         table = (unsigned char *)sechdrs[me->arch.unwind_section].sh_addr;
 841         end = table + sechdrs[me->arch.unwind_section].sh_size;
 842         gp = (Elf_Addr)me->core_layout.base + me->arch.got_offset;
 843 
 844         pr_debug("register_unwind_table(), sect = %d at 0x%p - 0x%p (gp=0x%lx)\n",
 845                me->arch.unwind_section, table, end, gp);
 846         me->arch.unwind = unwind_table_add(me->name, 0, gp, table, end);
 847 }
 848 
 849 static void
 850 deregister_unwind_table(struct module *me)
 851 {
 852         if (me->arch.unwind)
 853                 unwind_table_remove(me->arch.unwind);
 854 }
 855 
 856 int module_finalize(const Elf_Ehdr *hdr,
 857                     const Elf_Shdr *sechdrs,
 858                     struct module *me)
 859 {
 860         int i;
 861         unsigned long nsyms;
 862         const char *strtab = NULL;
 863         const Elf_Shdr *s;
 864         char *secstrings;
 865         int err, symindex = -1;
 866         Elf_Sym *newptr, *oldptr;
 867         Elf_Shdr *symhdr = NULL;
 868 #ifdef DEBUG
 869         Elf_Fdesc *entry;
 870         u32 *addr;
 871 
 872         entry = (Elf_Fdesc *)me->init;
 873         printk("FINALIZE, ->init FPTR is %p, GP %lx ADDR %lx\n", entry,
 874                entry->gp, entry->addr);
 875         addr = (u32 *)entry->addr;
 876         printk("INSNS: %x %x %x %x\n",
 877                addr[0], addr[1], addr[2], addr[3]);
 878         printk("got entries used %ld, gots max %ld\n"
 879                "fdescs used %ld, fdescs max %ld\n",
 880                me->arch.got_count, me->arch.got_max,
 881                me->arch.fdesc_count, me->arch.fdesc_max);
 882 #endif
 883 
 884         register_unwind_table(me, sechdrs);
 885 
 886         /* haven't filled in me->symtab yet, so have to find it
 887          * ourselves */
 888         for (i = 1; i < hdr->e_shnum; i++) {
 889                 if(sechdrs[i].sh_type == SHT_SYMTAB
 890                    && (sechdrs[i].sh_flags & SHF_ALLOC)) {
 891                         int strindex = sechdrs[i].sh_link;
 892                         symindex = i;
 893                         /* FIXME: AWFUL HACK
 894                          * The cast is to drop the const from
 895                          * the sechdrs pointer */
 896                         symhdr = (Elf_Shdr *)&sechdrs[i];
 897                         strtab = (char *)sechdrs[strindex].sh_addr;
 898                         break;
 899                 }
 900         }
 901 
 902         pr_debug("module %s: strtab %p, symhdr %p\n",
 903                me->name, strtab, symhdr);
 904 
 905         if(me->arch.got_count > MAX_GOTS) {
 906                 printk(KERN_ERR "%s: Global Offset Table overflow (used %ld, allowed %d)\n",
 907                                 me->name, me->arch.got_count, MAX_GOTS);
 908                 return -EINVAL;
 909         }
 910 
 911         kfree(me->arch.section);
 912         me->arch.section = NULL;
 913 
 914         /* no symbol table */
 915         if(symhdr == NULL)
 916                 return 0;
 917 
 918         oldptr = (void *)symhdr->sh_addr;
 919         newptr = oldptr + 1;    /* we start counting at 1 */
 920         nsyms = symhdr->sh_size / sizeof(Elf_Sym);
 921         pr_debug("OLD num_symtab %lu\n", nsyms);
 922 
 923         for (i = 1; i < nsyms; i++) {
 924                 oldptr++;       /* note, count starts at 1 so preincrement */
 925                 if(strncmp(strtab + oldptr->st_name,
 926                               ".L", 2) == 0)
 927                         continue;
 928 
 929                 if(newptr != oldptr)
 930                         *newptr++ = *oldptr;
 931                 else
 932                         newptr++;
 933 
 934         }
 935         nsyms = newptr - (Elf_Sym *)symhdr->sh_addr;
 936         pr_debug("NEW num_symtab %lu\n", nsyms);
 937         symhdr->sh_size = nsyms * sizeof(Elf_Sym);
 938 
 939         /* find .altinstructions section */
 940         secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
 941         for (s = sechdrs; s < sechdrs + hdr->e_shnum; s++) {
 942                 void *aseg = (void *) s->sh_addr;
 943                 char *secname = secstrings + s->sh_name;
 944 
 945                 if (!strcmp(".altinstructions", secname))
 946                         /* patch .altinstructions */
 947                         apply_alternatives(aseg, aseg + s->sh_size, me->name);
 948 
 949                 /* For 32 bit kernels we're compiling modules with
 950                  * -ffunction-sections so we must relocate the addresses in the
 951                  *__mcount_loc section.
 952                  */
 953                 if (symindex != -1 && !strcmp(secname, "__mcount_loc")) {
 954                         if (s->sh_type == SHT_REL)
 955                                 err = apply_relocate((Elf_Shdr *)sechdrs,
 956                                                         strtab, symindex,
 957                                                         s - sechdrs, me);
 958                         else if (s->sh_type == SHT_RELA)
 959                                 err = apply_relocate_add((Elf_Shdr *)sechdrs,
 960                                                         strtab, symindex,
 961                                                         s - sechdrs, me);
 962                         if (err)
 963                                 return err;
 964                 }
 965         }
 966         return 0;
 967 }
 968 
 969 void module_arch_cleanup(struct module *mod)
 970 {
 971         deregister_unwind_table(mod);
 972 }
 973 
 974 #ifdef CONFIG_64BIT
 975 void *dereference_module_function_descriptor(struct module *mod, void *ptr)
 976 {
 977         unsigned long start_opd = (Elf64_Addr)mod->core_layout.base +
 978                                    mod->arch.fdesc_offset;
 979         unsigned long end_opd = start_opd +
 980                                 mod->arch.fdesc_count * sizeof(Elf64_Fdesc);
 981 
 982         if (ptr < (void *)start_opd || ptr >= (void *)end_opd)
 983                 return ptr;
 984 
 985         return dereference_function_descriptor(ptr);
 986 }
 987 #endif
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root/arch/parisc/kernel/module.c

DEFINITIONS
