dl-machine.h

glibc 2.9,最新版的C语言库函数

  PPC_DCBT (&plt->fd_func);
  PPC_DCBT (&rel->fd_aux);
  PPC_DCBT (&rel->fd_func);

  /* If sym_map is NULL, it's a weak undefined sym;  Leave the plt zero.  */
  if (sym_map == NULL)
    return 0;

  /* If the opd entry is not yet relocated (because it's from a shared
     object that hasn't been processed yet), then manually reloc it.  */
  if (map != sym_map && !sym_map->l_relocated
#if !defined RTLD_BOOTSTRAP && defined SHARED
      /* Bootstrap map doesn't have l_relocated set for it.  */
      && sym_map != &GL(dl_rtld_map)
#endif
      )
    offset = sym_map->l_addr;

  /* For PPC64, fixup_plt copies the function descriptor from opd
     over the corresponding PLT entry.
     Initially, PLT Entry[i] is set up for lazy linking, or is zero.
     For lazy linking, the fd_toc and fd_aux entries are irrelevant,
     so for thread safety we write them before changing fd_func.  */

  plt->fd_aux = rel->fd_aux + offset;
  plt->fd_toc = rel->fd_toc + offset;
  PPC_DCBF (&plt->fd_toc);
  PPC_ISYNC;

  plt->fd_func = rel->fd_func + offset;
  PPC_DCBST (&plt->fd_func);
  PPC_ISYNC;

  return finaladdr;
}

static inline void __attribute__ ((always_inline))
elf_machine_plt_conflict (Elf64_Addr *reloc_addr, Elf64_Addr finaladdr)
{
  Elf64_FuncDesc *plt = (Elf64_FuncDesc *) reloc_addr;
  Elf64_FuncDesc *rel = (Elf64_FuncDesc *) finaladdr;

  plt->fd_func = rel->fd_func;
  plt->fd_aux = rel->fd_aux;
  plt->fd_toc = rel->fd_toc;
  PPC_DCBST (&plt->fd_func);
  PPC_DCBST (&plt->fd_aux);
  PPC_DCBST (&plt->fd_toc);
  PPC_SYNC;
}

/* Return the final value of a plt relocation.  */
static inline Elf64_Addr
elf_machine_plt_value (struct link_map *map, const Elf64_Rela *reloc,
		       Elf64_Addr value)
{
  return value + reloc->r_addend;
}


/* Names of the architecture-specific auditing callback functions.  */
#define ARCH_LA_PLTENTER ppc64_gnu_pltenter
#define ARCH_LA_PLTEXIT ppc64_gnu_pltexit

#endif /* dl_machine_h */

#ifdef RESOLVE_MAP

#define PPC_LO(v) ((v) & 0xffff)
#define PPC_HI(v) (((v) >> 16) & 0xffff)
#define PPC_HA(v) PPC_HI ((v) + 0x8000)
#define PPC_HIGHER(v) (((v) >> 32) & 0xffff)
#define PPC_HIGHERA(v) PPC_HIGHER ((v) + 0x8000)
#define PPC_HIGHEST(v) (((v) >> 48) & 0xffff)
#define PPC_HIGHESTA(v) PPC_HIGHEST ((v) + 0x8000)
#define BIT_INSERT(var, val, mask) \
  ((var) = ((var) & ~(Elf64_Addr) (mask)) | ((val) & (mask)))

#define dont_expect(X) __builtin_expect ((X), 0)

extern void _dl_reloc_overflow (struct link_map *map,
                                const char *name,
                                Elf64_Addr *const reloc_addr,
                                const Elf64_Sym *refsym)
                                attribute_hidden;

auto inline void __attribute__ ((always_inline))
elf_machine_rela_relative (Elf64_Addr l_addr, const Elf64_Rela *reloc,
			   void *const reloc_addr_arg)
{
  Elf64_Addr *const reloc_addr = reloc_addr_arg;
  *reloc_addr = l_addr + reloc->r_addend;
}

#if !defined RTLD_BOOTSTRAP || USE___THREAD
/* This computes the value used by TPREL* relocs.  */
auto inline Elf64_Addr __attribute__ ((always_inline, const))
elf_machine_tprel (struct link_map *map,
		   struct link_map *sym_map,
		   const Elf64_Sym *sym,
		   const Elf64_Rela *reloc)
{
# ifndef RTLD_BOOTSTRAP
  if (sym_map)
    {
      CHECK_STATIC_TLS (map, sym_map);
# endif
      return TLS_TPREL_VALUE (sym_map, sym, reloc);
# ifndef RTLD_BOOTSTRAP
    }
# endif
  return 0;
}
#endif

/* Perform the relocation specified by RELOC and SYM (which is fully
   resolved).  MAP is the object containing the reloc.  */
auto inline void __attribute__ ((always_inline))
elf_machine_rela (struct link_map *map,
		  const Elf64_Rela *reloc,
		  const Elf64_Sym *sym,
		  const struct r_found_version *version,
		  void *const reloc_addr_arg)
{
  Elf64_Addr *const reloc_addr = reloc_addr_arg;
  const int r_type = ELF64_R_TYPE (reloc->r_info);
#ifndef RTLD_BOOTSTRAP
  const Elf64_Sym *const refsym = sym;
#endif

  if (r_type == R_PPC64_RELATIVE)
    {
      *reloc_addr = map->l_addr + reloc->r_addend;
      return;
    }

  if (__builtin_expect (r_type == R_PPC64_NONE, 0))
    return;

  /* We need SYM_MAP even in the absence of TLS, for elf_machine_fixup_plt.  */
  struct link_map *sym_map = RESOLVE_MAP (&sym, version, r_type);
  Elf64_Addr value = ((sym_map == NULL ? 0 : sym_map->l_addr + sym->st_value)
		      + reloc->r_addend);

  /* For relocs that don't edit code, return.
     For relocs that might edit instructions, break from the switch.  */
  switch (r_type)
    {
    case R_PPC64_ADDR64:
    case R_PPC64_GLOB_DAT:
      *reloc_addr = value;
      return;

    case R_PPC64_JMP_SLOT:
#ifdef RESOLVE_CONFLICT_FIND_MAP
      elf_machine_plt_conflict (reloc_addr, value);
#else
      elf_machine_fixup_plt (map, sym_map, reloc, reloc_addr, value);
#endif
      return;

#if !defined RTLD_BOOTSTRAP || USE___THREAD
    case R_PPC64_DTPMOD64:
# ifdef RTLD_BOOTSTRAP
      /* During startup the dynamic linker is always index 1.  */
      *reloc_addr = 1;
# else
      /* Get the information from the link map returned by the
	 resolve function.  */
      if (sym_map != NULL)
        *reloc_addr = sym_map->l_tls_modid;
# endif
      return;

    case R_PPC64_DTPREL64:
      /* During relocation all TLS symbols are defined and used.
         Therefore the offset is already correct.  */
# ifndef RTLD_BOOTSTRAP
      if (sym_map != NULL)
	*reloc_addr = TLS_DTPREL_VALUE (sym, reloc);
# endif
      return;

    case R_PPC64_TPREL64:
      *reloc_addr = elf_machine_tprel (map, sym_map, sym, reloc);
      return;

    case R_PPC64_TPREL16_LO_DS:
      value = elf_machine_tprel (map, sym_map, sym, reloc);
      if (dont_expect ((value & 3) != 0))
        _dl_reloc_overflow (map, "R_PPC64_TPREL16_LO_DS", reloc_addr, refsym);
      *(Elf64_Half *) reloc_addr = BIT_INSERT (*(Elf64_Half *) reloc_addr,
					       value, 0xfffc);
      break;

    case R_PPC64_TPREL16_DS:
      value = elf_machine_tprel (map, sym_map, sym, reloc);
      if (dont_expect ((value + 0x8000) >= 0x10000 || (value & 3) != 0))
        _dl_reloc_overflow (map, "R_PPC64_TPREL16_DS", reloc_addr, refsym);
      *(Elf64_Half *) reloc_addr = BIT_INSERT (*(Elf64_Half *) reloc_addr,
					       value, 0xfffc);
      break;

    case R_PPC64_TPREL16:
      value = elf_machine_tprel (map, sym_map, sym, reloc);
      if (dont_expect ((value + 0x8000) >= 0x10000))
        _dl_reloc_overflow (map, "R_PPC64_TPREL16", reloc_addr, refsym);
      *(Elf64_Half *) reloc_addr = PPC_LO (value);
      break;

    case R_PPC64_TPREL16_LO:
      value = elf_machine_tprel (map, sym_map, sym, reloc);
      *(Elf64_Half *) reloc_addr = PPC_LO (value);
      break;

    case R_PPC64_TPREL16_HI:
      value = elf_machine_tprel (map, sym_map, sym, reloc);
      *(Elf64_Half *) reloc_addr = PPC_HI (value);
      break;

    case R_PPC64_TPREL16_HA:
      value = elf_machine_tprel (map, sym_map, sym, reloc);
      *(Elf64_Half *) reloc_addr = PPC_HA (value);
      break;

    case R_PPC64_TPREL16_HIGHER:
      value = elf_machine_tprel (map, sym_map, sym, reloc);
      *(Elf64_Half *) reloc_addr = PPC_HIGHER (value);
      break;

    case R_PPC64_TPREL16_HIGHEST:
      value = elf_machine_tprel (map, sym_map, sym, reloc);
      *(Elf64_Half *) reloc_addr = PPC_HIGHEST (value);
      break;

    case R_PPC64_TPREL16_HIGHERA:
      value = elf_machine_tprel (map, sym_map, sym, reloc);
      *(Elf64_Half *) reloc_addr = PPC_HIGHERA (value);
      break;

    case R_PPC64_TPREL16_HIGHESTA:
      value = elf_machine_tprel (map, sym_map, sym, reloc);
      *(Elf64_Half *) reloc_addr = PPC_HIGHESTA (value);
      break;
#endif

#ifndef RTLD_BOOTSTRAP /* None of the following appear in ld.so */
    case R_PPC64_ADDR16_LO_DS:
      if (dont_expect ((value & 3) != 0))
        _dl_reloc_overflow (map, "R_PPC64_ADDR16_LO_DS", reloc_addr, refsym);
      BIT_INSERT (*(Elf64_Half *) reloc_addr, value, 0xfffc);
      break;

    case R_PPC64_ADDR16_LO:
      *(Elf64_Half *) reloc_addr = PPC_LO (value);
      break;

    case R_PPC64_ADDR16_HI:
      *(Elf64_Half *) reloc_addr = PPC_HI (value);
      break;

    case R_PPC64_ADDR16_HA:
      *(Elf64_Half *) reloc_addr = PPC_HA (value);
      break;

    case R_PPC64_ADDR30:
      {
        Elf64_Addr delta = value - (Elf64_Xword) reloc_addr;
        if (dont_expect ((delta + 0x80000000) >= 0x10000000
			 || (delta & 3) != 0))
          _dl_reloc_overflow (map, "R_PPC64_ADDR30", reloc_addr, refsym);
        BIT_INSERT (*(Elf64_Word *) reloc_addr, delta, 0xfffffffc);
      }
      break;

    case R_PPC64_COPY:
      if (dont_expect (sym == NULL))
	/* This can happen in trace mode when an object could not be found. */
        return;
      if (dont_expect (sym->st_size > refsym->st_size
		       || (GLRO(dl_verbose)
			   && sym->st_size < refsym->st_size)))
	{
          const char *strtab;

          strtab = (const void *) D_PTR (map, l_info[DT_STRTAB]);
          _dl_error_printf ("%s: Symbol `%s' has different size" \
                            " in shared object," \
                            " consider re-linking\n",
                            _dl_argv[0] ?: "<program name unknown>",
			    strtab + refsym->st_name);
	}
      memcpy (reloc_addr_arg, (char *) value,
	      MIN (sym->st_size, refsym->st_size));
      return;

    case R_PPC64_UADDR64:
      /* We are big-endian.  */
      ((char *) reloc_addr_arg)[0] = (value >> 56) & 0xff;
      ((char *) reloc_addr_arg)[1] = (value >> 48) & 0xff;
      ((char *) reloc_addr_arg)[2] = (value >> 40) & 0xff;
      ((char *) reloc_addr_arg)[3] = (value >> 32) & 0xff;
      ((char *) reloc_addr_arg)[4] = (value >> 24) & 0xff;
      ((char *) reloc_addr_arg)[5] = (value >> 16) & 0xff;
      ((char *) reloc_addr_arg)[6] = (value >> 8) & 0xff;
      ((char *) reloc_addr_arg)[7] = (value >> 0) & 0xff;
      return;

    case R_PPC64_UADDR32:
      /* We are big-endian.  */
      ((char *) reloc_addr_arg)[0] = (value >> 24) & 0xff;
      ((char *) reloc_addr_arg)[1] = (value >> 16) & 0xff;
      ((char *) reloc_addr_arg)[2] = (value >> 8) & 0xff;
      ((char *) reloc_addr_arg)[3] = (value >> 0) & 0xff;
      return;

    case R_PPC64_ADDR32:
      if (dont_expect ((value + 0x80000000) >= 0x10000000))
        _dl_reloc_overflow (map, "R_PPC64_ADDR32", reloc_addr, refsym);
      *(Elf64_Word *) reloc_addr = value;
      return;

    case R_PPC64_ADDR24:
      if (dont_expect ((value + 0x2000000) >= 0x4000000 || (value & 3) != 0))
        _dl_reloc_overflow (map, "R_PPC64_ADDR24", reloc_addr, refsym);
      BIT_INSERT (*(Elf64_Word *) reloc_addr, value, 0x3fffffc);
      break;

    case R_PPC64_ADDR16:
      if (dont_expect ((value + 0x8000) >= 0x10000))
        _dl_reloc_overflow (map, "R_PPC64_ADDR16", reloc_addr, refsym);
      *(Elf64_Half *) reloc_addr = value;
      break;

    case R_PPC64_UADDR16:
      if (dont_expect ((value + 0x8000) >= 0x10000))
        _dl_reloc_overflow (map, "R_PPC64_UADDR16", reloc_addr, refsym);
      /* We are big-endian.  */
      ((char *) reloc_addr_arg)[0] = (value >> 8) & 0xff;
      ((char *) reloc_addr_arg)[1] = (value >> 0) & 0xff;
      break;

    case R_PPC64_ADDR16_DS:
      if (dont_expect ((value + 0x8000) >= 0x10000 || (value & 3) != 0))
        _dl_reloc_overflow (map, "R_PPC64_ADDR16_DS", reloc_addr, refsym);
      BIT_INSERT (*(Elf64_Half *) reloc_addr, value, 0xfffc);
      break;

    case R_PPC64_ADDR16_HIGHER:
      *(Elf64_Half *) reloc_addr = PPC_HIGHER (value);
      break;

    case R_PPC64_ADDR16_HIGHEST:
      *(Elf64_Half *) reloc_addr = PPC_HIGHEST (value);
      break;

    case R_PPC64_ADDR16_HIGHERA:
      *(Elf64_Half *) reloc_addr = PPC_HIGHERA (value);
      break;

    case R_PPC64_ADDR16_HIGHESTA:
      *(Elf64_Half *) reloc_addr = PPC_HIGHESTA (value);
      break;

    case R_PPC64_ADDR14:
    case R_PPC64_ADDR14_BRTAKEN:
    case R_PPC64_ADDR14_BRNTAKEN:
      {
        if (dont_expect ((value + 0x8000) >= 0x10000 || (value & 3) != 0))
	  _dl_reloc_overflow (map, "R_PPC64_ADDR14", reloc_addr, refsym);
        Elf64_Word insn = *(Elf64_Word *) reloc_addr;
        BIT_INSERT (insn, value, 0xfffc);
        if (r_type != R_PPC64_ADDR14)
	  {
	    insn &= ~(1 << 21);
	    if (r_type == R_PPC64_ADDR14_BRTAKEN)
	      insn |= 1 << 21;
	    if ((insn & (0x14 << 21)) == (0x04 << 21))
	      insn |= 0x02 << 21;
	    else if ((insn & (0x14 << 21)) == (0x10 << 21))
	      insn |= 0x08 << 21;
	  }
        *(Elf64_Word *) reloc_addr = insn;
      }
      break;

    case R_PPC64_REL32:
      *(Elf64_Word *) reloc_addr = value - (Elf64_Addr) reloc_addr;
      return;

    case R_PPC64_REL64:
      *reloc_addr = value - (Elf64_Addr) reloc_addr;
      return;
#endif /* !RTLD_BOOTSTRAP */

    default:
      _dl_reloc_bad_type (map, r_type, 0);
      return;
    }
  MODIFIED_CODE_NOQUEUE (reloc_addr);
}

auto inline void __attribute__ ((always_inline))
elf_machine_lazy_rel (struct link_map *map,
		      Elf64_Addr l_addr, const Elf64_Rela *reloc)
{
  /* elf_machine_runtime_setup handles this.  */
}


#endif /* RESOLVE */