dl-machine.h

glibc 2.9,最新版的C语言库函数

/* Undo the sub %sp, 6*8, %sp; add %sp, STACK_BIAS + 22*8, %o0 below
   to get at the value we want in __libc_stack_end.  */
#define DL_STACK_END(cookie) \
  ((void *) (((long) (cookie)) - (22 - 6) * 8 - STACK_BIAS))

/* Initial entry point code for the dynamic linker.
   The C function `_dl_start' is the real entry point;
   its return value is the user program's entry point.  */

#define __S1(x)	#x
#define __S(x)	__S1(x)

#define RTLD_START __asm__ ( "\n"					\
"	.text\n"							\
"	.global	_start\n"						\
"	.type	_start, @function\n"					\
"	.align	32\n"							\
"_start:\n"								\
"   /* Make room for functions to drop their arguments on the stack.  */\n" \
"	sub	%sp, 6*8, %sp\n"					\
"   /* Pass pointer to argument block to _dl_start.  */\n"		\
"	call	_dl_start\n"						\
"	 add	 %sp," __S(STACK_BIAS) "+22*8,%o0\n"			\
"	/* FALLTHRU */\n"						\
"	.size _start, .-_start\n"					\
"\n"									\
"	.global	_dl_start_user\n"					\
"	.type	_dl_start_user, @function\n"				\
"_dl_start_user:\n"							\
"   /* Load the GOT register.  */\n"					\
"1:	call	11f\n"							\
"	 sethi	%hi(_GLOBAL_OFFSET_TABLE_-(1b-.)), %l7\n"		\
"11:	or	%l7, %lo(_GLOBAL_OFFSET_TABLE_-(1b-.)), %l7\n"		\
"	sethi	%hi(_dl_skip_args), %g5\n"				\
"	add	%l7, %o7, %l7\n"					\
"	or	%g5, %lo(_dl_skip_args), %g5\n"				\
"   /* Save the user entry point address in %l0.  */\n"			\
"	mov	%o0, %l0\n"						\
"   /* See if we were run as a command with the executable file name as an\n" \
"      extra leading argument.  If so, we must shift things around since we\n" \
"      must keep the stack doubleword aligned.  */\n"			\
"	ldx	[%l7 + %g5], %i0\n"					\
"	ld	[%i0], %i0\n"						\
"	brz,pt	%i0, 2f\n"						\
"	 ldx	[%sp + " __S(STACK_BIAS) " + 22*8], %i5\n"		\
"	/* Find out how far to shift.  */\n"				\
"	sethi	%hi(_dl_argv), %l4\n"					\
"	sub	%i5, %i0, %i5\n"					\
"	or	%l4, %lo(_dl_argv), %l4\n"				\
"	sllx	%i0, 3, %l6\n"						\
"	ldx	[%l7 + %l4], %l4\n"					\
"	stx	%i5, [%sp + " __S(STACK_BIAS) " + 22*8]\n"		\
"	add	%sp, " __S(STACK_BIAS) " + 23*8, %i1\n"			\
"	add	%i1, %l6, %i2\n"					\
"	ldx	[%l4], %l5\n"						\
"	/* Copy down argv.  */\n"					\
"12:	ldx	[%i2], %i3\n"						\
"	add	%i2, 8, %i2\n"						\
"	stx	%i3, [%i1]\n"						\
"	brnz,pt	%i3, 12b\n"						\
"	 add	%i1, 8, %i1\n"						\
"	sub	%l5, %l6, %l5\n"					\
"	/* Copy down envp.  */\n"					\
"13:	ldx	[%i2], %i3\n"						\
"	add	%i2, 8, %i2\n"						\
"	stx	%i3, [%i1]\n"						\
"	brnz,pt	%i3, 13b\n"						\
"	 add	%i1, 8, %i1\n"						\
"	/* Copy down auxiliary table.  */\n"				\
"14:	ldx	[%i2], %i3\n"						\
"	ldx	[%i2 + 8], %i4\n"					\
"	add	%i2, 16, %i2\n"						\
"	stx	%i3, [%i1]\n"						\
"	stx	%i4, [%i1 + 8]\n"					\
"	brnz,pt	%i3, 14b\n"						\
"	 add	%i1, 16, %i1\n"						\
"	stx	%l5, [%l4]\n"						\
"  /* %o0 = _dl_loaded, %o1 = argc, %o2 = argv, %o3 = envp.  */\n"	\
"2:	sethi	%hi(_rtld_local), %o0\n"				\
"	add	%sp, " __S(STACK_BIAS) " + 23*8, %o2\n"			\
"	orcc	%o0, %lo(_rtld_local), %o0\n"				\
"	sllx	%i5, 3, %o3\n"						\
"	ldx	[%l7 + %o0], %o0\n"					\
"	add	%o3, 8, %o3\n"						\
"	mov	%i5, %o1\n"						\
"	add	%o2, %o3, %o3\n"					\
"	call	_dl_init_internal\n"					\
"	 ldx	[%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"				\
"	ldx	[%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*8, %sp\n"					\
"	.size	_dl_start_user, . - _dl_start_user\n"			\
"	.previous\n");

#endif /* dl_machine_h */

#define ARCH_LA_PLTENTER	sparc64_gnu_pltenter
#define ARCH_LA_PLTEXIT		sparc64_gnu_pltexit

#ifdef RESOLVE_MAP

/* 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;
#if !defined RTLD_BOOTSTRAP && !defined RESOLVE_CONFLICT_FIND_MAP
  const Elf64_Sym *const refsym = sym;
#endif
  Elf64_Addr value;
  const unsigned long int r_type = ELF64_R_TYPE_ID (reloc->r_info);
#if !defined RESOLVE_CONFLICT_FIND_MAP
  struct link_map *sym_map = NULL;
#endif

#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 (__builtin_expect (r_type == R_SPARC_NONE, 0))
    return;

#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;
      return;
    }
#endif

#ifndef RESOLVE_CONFLICT_FIND_MAP
  if (__builtin_expect (ELF64_ST_BIND (sym->st_info) == STB_LOCAL, 0)
      && sym->st_shndx != SHN_UNDEF)
    {
      value = map->l_addr;
    }
  else
    {
      sym_map = RESOLVE_MAP (&sym, version, r_type);
      value = sym_map == NULL ? 0 : sym_map->l_addr + sym->st_value;
    }
#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
	  || (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",
			    rtld_progname ?: "<program name unknown>",
			    strtab + refsym->st_name);
	}
      memcpy (reloc_addr_arg, (void *) value,
	      MIN (sym->st_size, refsym->st_size));
      break;
#endif
    case R_SPARC_64:
    case R_SPARC_GLOB_DAT:
      *reloc_addr = value;
      break;
    case R_SPARC_JMP_SLOT:
#ifdef RESOLVE_CONFLICT_FIND_MAP
      /* R_SPARC_JMP_SLOT conflicts against .plt[32768+]
	 relocs should be turned into R_SPARC_64 relocs
	 in .gnu.conflict section.
	 r_addend non-zero does not mean it is a .plt[32768+]
	 reloc, instead it is the actual address of the function
	 to call.  */
      sparc64_fixup_plt (NULL, reloc, reloc_addr, value, 0, 0);
#else
      sparc64_fixup_plt (map, reloc, reloc_addr, value, reloc->r_addend, 0);
#endif
      break;
#if (!defined RTLD_BOOTSTRAP || USE___THREAD) \
    && !defined RESOLVE_CONFLICT_FIND_MAP
    case R_SPARC_TLS_DTPMOD64:
      /* 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_DTPOFF64:
      /* 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_TPOFF64:
      /* 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.  */
      if (sym != NULL)
	{
	  CHECK_STATIC_TLS (map, sym_map);
	  *reloc_addr = 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:
      if (sym != NULL)
	{
	  CHECK_STATIC_TLS (map, sym_map);
	  value = 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) & 0x3fffff);
	  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_32:
      *(unsigned int *) reloc_addr = value;
      break;
    case R_SPARC_DISP8:
      *(char *) reloc_addr = (value - (Elf64_Addr) reloc_addr);
      break;
    case R_SPARC_DISP16:
      *(short *) reloc_addr = (value - (Elf64_Addr) reloc_addr);
      break;
    case R_SPARC_DISP32:
      *(unsigned int *) reloc_addr = (value - (Elf64_Addr) reloc_addr);
      break;
    case R_SPARC_WDISP30:
      *(unsigned int *) reloc_addr =
	((*(unsigned int *)reloc_addr & 0xc0000000) |
	 (((value - (Elf64_Addr) reloc_addr) >> 2) & 0x3fffffff));
      break;

      /* MEDLOW code model relocs */
    case R_SPARC_LO10:
      *(unsigned int *) reloc_addr =
	((*(unsigned int *)reloc_addr & ~0x3ff) |
	 (value & 0x3ff));
      break;
    case R_SPARC_HI22:
      *(unsigned int *) reloc_addr =
	((*(unsigned int *)reloc_addr & 0xffc00000) |
	 ((value >> 10) & 0x3fffff));
      break;
    case R_SPARC_OLO10:
      *(unsigned int *) reloc_addr =
	((*(unsigned int *)reloc_addr & ~0x1fff) |
	 (((value & 0x3ff) + ELF64_R_TYPE_DATA (reloc->r_info)) & 0x1fff));
      break;

      /* MEDMID code model relocs */
    case R_SPARC_H44:
      *(unsigned int *) reloc_addr =
	((*(unsigned int *)reloc_addr & 0xffc00000) |
	 ((value >> 22) & 0x3fffff));
      break;
    case R_SPARC_M44:
      *(unsigned int *) reloc_addr =
	((*(unsigned int *)reloc_addr & ~0x3ff) |
	 ((value >> 12) & 0x3ff));
      break;
    case R_SPARC_L44:
      *(unsigned int *) reloc_addr =
	((*(unsigned int *)reloc_addr & ~0xfff) |
	 (value & 0xfff));
      break;

      /* MEDANY code model relocs */
    case R_SPARC_HH22:
      *(unsigned int *) reloc_addr =
	((*(unsigned int *)reloc_addr & 0xffc00000) |
	 (value >> 42));
      break;
    case R_SPARC_HM10:
      *(unsigned int *) reloc_addr =
	((*(unsigned int *)reloc_addr & ~0x3ff) |
	 ((value >> 32) & 0x3ff));
      break;
    case R_SPARC_LM22:
      *(unsigned int *) reloc_addr =
	((*(unsigned int *)reloc_addr & 0xffc00000) |
	 ((value >> 10) & 0x003fffff));
      break;
    case R_SPARC_UA16:
      ((unsigned char *) reloc_addr_arg) [0] = value >> 8;
      ((unsigned char *) reloc_addr_arg) [1] = value;
      break;
    case R_SPARC_UA32:
      ((unsigned char *) reloc_addr_arg) [0] = value >> 24;
      ((unsigned char *) reloc_addr_arg) [1] = value >> 16;
      ((unsigned char *) reloc_addr_arg) [2] = value >> 8;
      ((unsigned char *) reloc_addr_arg) [3] = value;
      break;
    case R_SPARC_UA64:
      if (! ((long) reloc_addr_arg & 3))
	{
	  /* Common in .eh_frame */
	  ((unsigned int *) reloc_addr_arg) [0] = value >> 32;
	  ((unsigned int *) reloc_addr_arg) [1] = value;
	  break;
	}
      ((unsigned char *) reloc_addr_arg) [0] = value >> 56;
      ((unsigned char *) reloc_addr_arg) [1] = value >> 48;
      ((unsigned char *) reloc_addr_arg) [2] = value >> 40;
      ((unsigned char *) reloc_addr_arg) [3] = value >> 32;
      ((unsigned char *) reloc_addr_arg) [4] = value >> 24;
      ((unsigned char *) reloc_addr_arg) [5] = value >> 16;
      ((unsigned char *) reloc_addr_arg) [6] = value >> 8;
      ((unsigned char *) reloc_addr_arg) [7] = value;
      break;
#endif
#if !defined RTLD_BOOTSTRAP || defined _NDEBUG
    default:
      _dl_reloc_bad_type (map, r_type, 0);
      break;
#endif
    }
}

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;
}

auto inline void
__attribute__ ((always_inline))
elf_machine_lazy_rel (struct link_map *map,
		      Elf64_Addr l_addr, const Elf64_Rela *reloc)
{
  switch (ELF64_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_MAP */