dl-machine.h

Glibc 2.3.2源代码(解压后有100多M)

21:	ld	[%i2], %i3\n\
	add	%i2, 4, %i2\n\
	tst	%i3\n\
	st	%i3, [%i1]\n\
	bne	21b\n\
	 add	%i1, 4, %i1\n\
	/* Copy down env */\n\
22:	ld	[%i2], %i3\n\
	add	%i2, 4, %i2\n\
	tst	%i3\n\
	st	%i3, [%i1]\n\
	bne	22b\n\
	 add	%i1, 4, %i1\n\
	/* Copy down auxiliary table.  */\n\
23:	ld	[%i2], %i3\n\
	ld	[%i2+4], %i4\n\
	add	%i2, 8, %i2\n\
	tst	%i3\n\
	st	%i3, [%i1]\n\
	st	%i4, [%i1+4]\n\
	bne	23b\n\
	 add	%i1, 8, %i1\n\
  /* %o0 = _dl_loaded, %o1 = argc, %o2 = argv, %o3 = envp.  */\n\
3:	sethi	%hi(_rtld_local), %o0\n\
	add	%sp, 23*4, %o2\n\
	orcc	%o0, %lo(_rtld_local), %o0\n\
	sll	%i5, 2, %o3\n\
	ld	[%l7+%o0], %o0\n\
	add	%o3, 4, %o3\n\
	mov	%i5, %o1\n\
	add	%o2, %o3, %o3\n\
	call	_dl_init_internal\n\
	 ld	[%o0], %o0\n\
  /* Pass our finalizer function to the user in %g1.  */\n\
	sethi	%hi(_dl_fini), %g1\n\
	or	%g1, %lo(_dl_fini), %g1\n\
	ld	[%l7+%g1], %g1\n\
  /* Jump to the user's entry point and deallocate the extra stack we got.  */\n\
	jmp	%l0\n\
	 add	%sp, 6*4, %sp\n\
	.size   _dl_start_user, . - _dl_start_user\n\
	.previous");

static inline Elf32_Addr
sparc_fixup_plt (const Elf32_Rela *reloc, Elf32_Addr *reloc_addr,
		 Elf32_Addr value, int t)
{
  Elf32_Sword disp = value - (Elf32_Addr) reloc_addr;
#ifndef RTLD_BOOTSTRAP
  /* Note that we don't mask the hwcap here, as the flush is essential to
     functionality on those cpu's that implement it.  */
  unsigned long *hwcap;
  int do_flush;
# ifndef SHARED
  weak_extern (_dl_hwcap);
# endif
  hwcap = WEAKADDR (GL(dl_hwcap));
  do_flush = (!hwcap || (*hwcap & HWCAP_SPARC_FLUSH));
#else
  /* Unfortunately, this is necessary, so that we can ensure
     ld.so will not execute corrupt PLT entry instructions. */
  const int do_flush = 1;
#endif

  if (0 && disp >= -0x800000 && disp < 0x800000)
    {
      /* Don't need to worry about thread safety. We're writing just one
	 instruction.  */

      reloc_addr[0] = OPCODE_BA | ((disp >> 2) & 0x3fffff);
      if (do_flush)
	__asm __volatile ("flush %0" : : "r"(reloc_addr));
    }
  else
    {
      /* For thread safety, write the instructions from the bottom and
	 flush before we overwrite the critical "b,a".  This of course
	 need not be done during bootstrapping, since there are no threads.
	 But we also can't tell if we _can_ use flush, so don't. */

      reloc_addr += t;
      reloc_addr[1] = OPCODE_JMP_G1 | (value & 0x3ff);
      if (do_flush)
	__asm __volatile ("flush %0+4" : : "r"(reloc_addr));

      reloc_addr[0] = OPCODE_SETHI_G1 | (value >> 10);
      if (do_flush)
	__asm __volatile ("flush %0" : : "r"(reloc_addr));
    }

  return value;
}

static inline Elf32_Addr
elf_machine_fixup_plt (struct link_map *map, lookup_t t,
		       const Elf32_Rela *reloc,
		       Elf32_Addr *reloc_addr, Elf32_Addr value)
{
  return sparc_fixup_plt (reloc, reloc_addr, value, 1);
}

/* Return the final value of a plt relocation.  */
static inline Elf32_Addr
elf_machine_plt_value (struct link_map *map, const Elf32_Rela *reloc,
		       Elf32_Addr value)
{
  return value + reloc->r_addend;
}

#endif /* dl_machine_h */

#ifdef RESOLVE

/* Perform the relocation specified by RELOC and SYM (which is fully resolved).
   MAP is the object containing the reloc.  */

static inline void
elf_machine_rela (struct link_map *map, const Elf32_Rela *reloc,
		  const Elf32_Sym *sym, const struct r_found_version *version,
		  Elf32_Addr *const reloc_addr)
{
  const unsigned int r_type = ELF32_R_TYPE (reloc->r_info);

#if !defined RTLD_BOOTSTRAP && !defined HAVE_Z_COMBRELOC
  /* This is defined in rtld.c, but nowhere in the static libc.a; make the
     reference weak so static programs can still link.  This declaration
     cannot be done when compiling rtld.c (i.e.  #ifdef RTLD_BOOTSTRAP)
     because rtld.c contains the common defn for _dl_rtld_map, which is
     incompatible with a weak decl in the same file.  */
  weak_extern (_dl_rtld_map);
#endif

#if !defined RTLD_BOOTSTRAP || !defined HAVE_Z_COMBRELOC
  if (__builtin_expect (r_type == R_SPARC_RELATIVE, 0))
    {
# if !defined RTLD_BOOTSTRAP && !defined HAVE_Z_COMBRELOC
      if (map != &_dl_rtld_map) /* Already done in rtld itself. */
# endif
	*reloc_addr += map->l_addr + reloc->r_addend;
    }
  else
#endif
    {
#if !defined RTLD_BOOTSTRAP && !defined RESOLVE_CONFLICT_FIND_MAP
      const Elf32_Sym *const refsym = sym;
#endif
#if defined USE_TLS && !defined RTLD_BOOTSTRAP
      struct link_map *sym_map;
#endif
      Elf32_Addr value;
#ifndef RESOLVE_CONFLICT_FIND_MAP
      if (sym->st_shndx != SHN_UNDEF &&
	  ELF32_ST_BIND (sym->st_info) == STB_LOCAL)
	{
	  value = map->l_addr;
# if defined USE_TLS && !defined RTLD_BOOTSTRAP
	  sym_map = map;
# endif
	}
      else
	{
# if defined USE_TLS && !defined RTLD_BOOTSTRAP
	  sym_map = RESOLVE_MAP (&sym, version, r_type);
	  value = sym == NULL ? 0 : sym_map->l_addr + sym->st_value;
# else	  
	  value = RESOLVE (&sym, version, r_type);
	  if (sym)
	    value += sym->st_value;
# endif
	}
#else
      value = 0;
#endif
      value += reloc->r_addend;	/* Assume copy relocs have zero addend.  */

      switch (r_type)
	{
#if !defined RTLD_BOOTSTRAP && !defined RESOLVE_CONFLICT_FIND_MAP
	case R_SPARC_COPY:
	  if (sym == NULL)
	    /* This can happen in trace mode if an object could not be
	       found.  */
	    break;
	  if (sym->st_size > refsym->st_size
	      || (GL(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",
				rtld_progname ?: "<program name unknown>",
				strtab + refsym->st_name);
	    }
	  memcpy (reloc_addr, (void *) value, MIN (sym->st_size,
						   refsym->st_size));
	  break;
#endif
	case R_SPARC_GLOB_DAT:
	case R_SPARC_32:
	  *reloc_addr = value;
	  break;
	case R_SPARC_JMP_SLOT:
	  /* At this point we don't need to bother with thread safety,
	     so we can optimize the first instruction of .plt out.  */
	  sparc_fixup_plt (reloc, reloc_addr, value, 0);
	  break;
#if defined USE_TLS && (!defined RTLD_BOOTSTRAP || USE___THREAD) \
    && !defined RESOLVE_CONFLICT_FIND_MAP
	case R_SPARC_TLS_DTPMOD32:
	  /* Get the information from the link map returned by the
	     resolv function.  */
	  if (sym_map != NULL)
	    *reloc_addr = sym_map->l_tls_modid;
	  break;
	case R_SPARC_TLS_DTPOFF32:
	  /* During relocation all TLS symbols are defined and used.
	     Therefore the offset is already correct.  */
	  *reloc_addr = (sym == NULL ? 0 : sym->st_value) + reloc->r_addend;
	  break;
	case R_SPARC_TLS_TPOFF32:
	  /* The offset is negative, forward from the thread pointer.  */
	  /* We know the offset of object the symbol is contained in.
	     It is a negative value which will be added to the
	     thread pointer.  */
	  CHECK_STATIC_TLS (map, sym_map);
	  *reloc_addr
	    = (sym == NULL ? 0 : sym->st_value - sym_map->l_tls_offset)
	      + reloc->r_addend;
	  break;
# ifndef RTLD_BOOTSTRAP
	case R_SPARC_TLS_LE_HIX22:
	case R_SPARC_TLS_LE_LOX10:
	  CHECK_STATIC_TLS (map, sym_map);
	  value = (sym == NULL ? 0 : sym->st_value - sym_map->l_tls_offset)
		  + reloc->r_addend;
	  if (r_type == R_SPARC_TLS_LE_HIX22)
	    *reloc_addr = (*reloc_addr & 0xffc00000) | ((~value) >> 10);
	  else
	    *reloc_addr = (*reloc_addr & 0xffffe000) | (value & 0x3ff)
			  | 0x1c00;
	  break;
# endif
#endif
#ifndef RTLD_BOOTSTRAP
	case R_SPARC_8:
	  *(char *) reloc_addr = value;
	  break;
	case R_SPARC_16:
	  *(short *) reloc_addr = value;
	  break;
	case R_SPARC_DISP8:
	  *(char *) reloc_addr = (value - (Elf32_Addr) reloc_addr);
	  break;
	case R_SPARC_DISP16:
	  *(short *) reloc_addr = (value - (Elf32_Addr) reloc_addr);
	  break;
	case R_SPARC_DISP32:
	  *reloc_addr = (value - (Elf32_Addr) reloc_addr);
	  break;
	case R_SPARC_LO10:
	  *reloc_addr = (*reloc_addr & ~0x3ff) | (value & 0x3ff);
	  break;
	case R_SPARC_WDISP30:
	  *reloc_addr = ((*reloc_addr & 0xc0000000)
			 | ((value - (unsigned int) reloc_addr) >> 2));
	  break;
	case R_SPARC_HI22:
	  *reloc_addr = (*reloc_addr & 0xffc00000) | (value >> 10);
	  break;
	case R_SPARC_UA16:
	  ((unsigned char *) reloc_addr) [0] = value >> 8;
	  ((unsigned char *) reloc_addr) [1] = value;
	  break;
	case R_SPARC_UA32:
	  ((unsigned char *) reloc_addr) [0] = value >> 24;
	  ((unsigned char *) reloc_addr) [1] = value >> 16;
	  ((unsigned char *) reloc_addr) [2] = value >> 8;
	  ((unsigned char *) reloc_addr) [3] = value;
	  break;
#endif
	case R_SPARC_NONE:		/* Alright, Wilbur.  */
	  break;
#if !defined RTLD_BOOTSTRAP || defined _NDEBUG
	default:
	  _dl_reloc_bad_type (map, r_type, 0);
	  break;
#endif
	}
    }
}

static inline void
elf_machine_rela_relative (Elf32_Addr l_addr, const Elf32_Rela *reloc,
			   Elf32_Addr *const reloc_addr)
{
  *reloc_addr += l_addr + reloc->r_addend;
}

static inline void
elf_machine_lazy_rel (struct link_map *map,
		      Elf32_Addr l_addr, const Elf32_Rela *reloc)
{
  switch (ELF32_R_TYPE (reloc->r_info))
    {
    case R_SPARC_NONE:
      break;
    case R_SPARC_JMP_SLOT:
      break;
    default:
      _dl_reloc_bad_type (map, ELFW(R_TYPE) (reloc->r_info), 1);
      break;
    }
}

#endif	/* RESOLVE */