Update.

[glibc.git] / sysdeps / sparc / sparc64 / dl-machine.h

/* Machine-dependent ELF dynamic relocation inline functions.  Sparc64 version.
   Copyright (C) 1997, 1998 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Library General Public License as
   published by the Free Software Foundation; either version 2 of the
   License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Library General Public License for more details.

   You should have received a copy of the GNU Library General Public
   License along with the GNU C Library; see the file COPYING.LIB.  If
   not, write to the Free Software Foundation, Inc.,
   59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */

#define ELF_MACHINE_NAME "sparc64"

#include <assert.h>
#include <string.h>
#include <sys/param.h>
#include <elf/ldsodefs.h>
#include <sysdep.h>

/* Return nonzero iff E_MACHINE is compatible with the running host.  */
static inline int
elf_machine_matches_host (Elf64_Half e_machine)
{
  return e_machine == EM_SPARCV9;
}

/* Return the link-time address of _DYNAMIC.  Conveniently, this is the
   first element of the GOT.  This must be inlined in a function which
   uses global data.  */
static inline Elf64_Addr
elf_machine_dynamic (void)
{
  register Elf64_Addr *elf_pic_register __asm__("%l7");

  return *elf_pic_register;
}

/* Return the run-time load address of the shared object.  */
static inline Elf64_Addr
elf_machine_load_address (void)
{
  register Elf64_Addr elf_pic_register __asm__("%l7");
  Elf64_Addr pc, la;

  /* Utilize the fact that a local .got entry will be partially
     initialized at startup awaiting its RELATIVE fixup.  */

  __asm("sethi %%hi(.Load_address), %1\n"
        ".Load_address:\n\t"
        "rd %%pc, %0\n\t"
        "or %1, %%lo(.Load_address), %1\n\t"
        : "=r"(pc), "=r"(la));

  return pc - *(Elf64_Addr *)(elf_pic_register + la);
}

/* We have 3 cases to handle.  And we code different code sequences
   for each one.  I love V9 code models...  */
static inline void
elf_machine_fixup_plt(struct link_map *map, const Elf64_Rela *reloc,
                      Elf64_Addr *reloc_addr, Elf64_Addr value)
{
  unsigned int *insns = (unsigned int *) reloc_addr;
  Elf64_Addr plt_vaddr = (Elf64_Addr) reloc_addr;

  /* Now move plt_vaddr up to the call instruction.  */
  plt_vaddr += (2 * 4);

  /* 32-bit Sparc style, the target is in the lower 32-bits of
     address space.  */
  if ((value >> 32) == 0)
    {
      /* sethi  %hi(target), %g1
         jmpl   %g1 + %lo(target), %g0  */

      insns[2] = 0x81c06000 | (value & 0x3ff);
      __asm __volatile ("flush %0 + 8" : : "r" (insns));

      insns[1] = 0x03000000 | ((unsigned int)(value >> 10));
      __asm __volatile ("flush %0 + 4" : : "r" (insns));
    }
  /* We can also get somewhat simple sequences if the distance between
     the target and the PLT entry is within +/- 2GB.  */
  else if ((plt_vaddr > value
            && ((plt_vaddr - value) >> 32) == 0)
           || (value > plt_vaddr
               && ((value - plt_vaddr) >> 32) == 0))
    {
      unsigned int displacement;

      if (plt_vaddr > value)
        displacement = (0 - (plt_vaddr - value));
      else
        displacement = value - plt_vaddr;

      /* mov    %o7, %g1
         call   displacement
          mov   %g1, %o7  */

      insns[3] = 0x9e100001;
      __asm __volatile ("flush %0 + 12" : : "r" (insns));

      insns[2] = 0x40000000 | (displacement >> 2);
      __asm __volatile ("flush %0 + 8" : : "r" (insns));

      insns[1] = 0x8210000f;
      __asm __volatile ("flush %0 + 4" : : "r" (insns));
    }
  /* Worst case, ho hum...  */
  else
    {
      unsigned int high32 = (value >> 32);
      unsigned int low32 = (unsigned int) value;

      /* ??? Some tricks can be stolen from the sparc64 egcs backend
             constant formation code I wrote.  -DaveM  */

      /* sethi  %hh(value), %g1
         sethi  %lm(value), %g2
         or     %g1, %hl(value), %g1
         or     %g2, %lo(value), %g2
         sllx   %g1, 32, %g1
         jmpl   %g1 + %g2, %g0
          nop  */

      insns[6] = 0x81c04002;
      __asm __volatile ("flush %0 + 24" : : "r" (insns));

      insns[5] = 0x83287020;
      __asm __volatile ("flush %0 + 20" : : "r" (insns));

      insns[4] = 0x8410a000 | (low32 & 0x3ff);
      __asm __volatile ("flush %0 + 16" : : "r" (insns));

      insns[3] = 0x82106000 | (high32 & 0x3ff);
      __asm __volatile ("flush %0 + 12" : : "r" (insns));

      insns[2] = 0x05000000 | (low32 >> 10);
      __asm __volatile ("flush %0 + 8" : : "r" (insns));

      insns[1] = 0x03000000 | (high32 >> 10);
      __asm __volatile ("flush %0 + 4" : : "r" (insns));
    }
}

/* 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;
}

#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 Elf64_Rela *reloc,
                  const Elf64_Sym *sym, const struct r_found_version *version,
                  Elf64_Addr *const reloc_addr)
{
#ifndef RTLD_BOOTSTRAP
  /* 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 (ELF64_R_TYPE (reloc->r_info) == R_SPARC_RELATIVE)
    {
#ifndef RTLD_BOOTSTRAP
      if (map != &_dl_rtld_map) /* Already done in rtld itself. */
#endif
        *reloc_addr = map->l_addr + reloc->r_addend;
    }
  else if (ELF64_R_TYPE (reloc->r_info) != R_SPARC_NONE) /* Who is Wilbur? */
    {
      const Elf64_Sym *const refsym = sym;
      Elf64_Addr value;
      if (sym->st_shndx != SHN_UNDEF &&
          ELF64_ST_BIND (sym->st_info) == STB_LOCAL)
        value = map->l_addr;
      else
        {
          value = RESOLVE (&sym, version, ELF64_R_TYPE (reloc->r_info));
          if (sym)
            value += sym->st_value;
        }
      value += reloc->r_addend; /* Assume copy relocs have zero addend.  */

      switch (ELF64_R_TYPE (reloc->r_info))
        {
        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
              || (_dl_verbose && sym->st_size < refsym->st_size))
            {
              extern char **_dl_argv;
              const char *strtab;

              strtab = ((void *) map->l_addr
                        + map->l_info[DT_STRTAB]->d_un.d_ptr);
              _dl_sysdep_error (_dl_argv[0] ?: "<program name unknown>",
                                ": Symbol `", strtab + refsym->st_name,
                                "' has different size in shared object, "
                                "consider re-linking\n", NULL);
            }
          memcpy (reloc_addr, (void *) value, MIN (sym->st_size,
                                                   refsym->st_size));
          break;

        case R_SPARC_64:
        case R_SPARC_GLOB_DAT:
          *reloc_addr = value;
          break;
        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));
          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));
          break;

        /* MEDMID code model relocs */
        case R_SPARC_H44:
          *(unsigned int *) reloc_addr =
            ((*(unsigned int *)reloc_addr & 0xffc00000) |
             (value >> 22));
          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_JMP_SLOT:
          elf_machine_fixup_plt(map, reloc, reloc_addr, value);
          break;

        default:
          assert (! "unexpected dynamic reloc type");
          break;
        }
    }
}

static inline void
elf_machine_lazy_rel (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:
      assert (! "unexpected PLT reloc type");
      break;
    }
}

#endif  /* RESOLVE */

/* Nonzero iff TYPE should not be allowed to resolve to one of
   the main executable's symbols, as for a COPY reloc.  */
#define elf_machine_lookup_noexec_p(type) ((type) == R_SPARC_COPY)

/* Nonzero iff TYPE describes relocation of a PLT entry, so
   PLT entries should not be allowed to define the value.  */
#define elf_machine_lookup_noplt_p(type) ((type) == R_SPARC_JMP_SLOT)

/* A reloc type used for ld.so cmdline arg lookups to reject PLT entries.  */
#define ELF_MACHINE_JMP_SLOT    R_SPARC_JMP_SLOT

/* The SPARC never uses Elf64_Rel relocations.  */
#define ELF_MACHINE_NO_REL 1

/* The SPARC overlaps DT_RELA and DT_PLTREL.  */
#define ELF_MACHINE_PLTREL_OVERLAP 1

/* Set up the loaded object described by L so its unrelocated PLT
   entries will jump to the on-demand fixup code in dl-runtime.c.  */

static inline int
elf_machine_runtime_setup (struct link_map *l, int lazy, int profile)
{
  if (l->l_info[DT_JMPREL] && lazy)
    {
      extern void _dl_runtime_resolve_0 (void);
      extern void _dl_runtime_resolve_1 (void);
      extern void _dl_runtime_profile_0 (void);
      extern void _dl_runtime_profile_1 (void);
      Elf64_Addr res0_addr, res1_addr;
      unsigned int *plt = (unsigned int *)
        (l->l_addr + l->l_info[DT_PLTGOT]->d_un.d_ptr);

      if (! profile)
        {
          res0_addr = (Elf64_Addr) &_dl_runtime_resolve_0;
          res1_addr = (Elf64_Addr) &_dl_runtime_resolve_1;
        }
      else
        {
          res0_addr = (Elf64_Addr) &_dl_runtime_profile_0;
          res1_addr = (Elf64_Addr) &_dl_runtime_profile_1;
          if (_dl_name_match_p (_dl_profile, l))
            _dl_profile_map = l;
        }

      /* PLT0 looks like:

         save   %sp, -192, %sp
         sethi  %hh(_dl_runtime_{resolve,profile}_0), %g3
         sethi  %lm(_dl_runtime_{resolve,profile}_0), %g4
         or     %g3, %hm(_dl_runtime_{resolve,profile}_0), %g3
         or     %g4, %lo(_dl_runtime_{resolve,profile}_0), %g4
         sllx   %g3, 32, %g3
         jmpl   %g3 + %g4, %o0
          nop

         PLT1 is similar except we jump to _dl_runtime_{resolve,profile}_1.  */

      plt[0] = 0x9de3bf40;
      plt[1] = 0x07000000 | (res0_addr >> (64 - 22));
      plt[2] = 0x09000000 | ((res0_addr >> 10) & 0x003fffff);
      plt[3] = 0x8610e000 | ((res0_addr >> 32) & 0x3ff);
      plt[4] = 0x88112000 | (res0_addr & 0x3ff);
      plt[5] = 0x8728f020;
      plt[6] = 0x91c0c004;
      plt[7] = 0x01000000;

      plt[8 + 0] = 0x9de3bf40;
      plt[8 + 1] = 0x07000000 | (res1_addr >> (64 - 22));
      plt[8 + 2] = 0x09000000 | ((res1_addr >> 10) & 0x003fffff);
      plt[8 + 3] = 0x8610e000 | ((res1_addr >> 32) & 0x3ff);
      plt[8 + 4] = 0x88112000 | (res1_addr & 0x3ff);
      plt[8 + 5] = 0x8728f020;
      plt[8 + 6] = 0x91c0c004;
      plt[8 + 7] = 0x01000000;

      /* Now put the magic cookie at the beginning of .PLT3
         Entry .PLT4 is unused by this implementation.  */
      *((struct link_map **)(&plt[16 + 0])) = l;
    }

  return lazy;
}

/* This code is used in dl-runtime.c to call the `fixup' function
   and then redirect to the address it returns.  */
#define TRAMPOLINE_TEMPLATE(tramp_name, fixup_name)     \
  asm ("\
        .text
        .globl  " #tramp_name "_0
        .type   " #tramp_name "_0, @function
        .align  32
" #tramp_name "_0:
        ldx     [%o0 + 32 + 8], %l0
        sethi   %hi(1048576), %g2
        sub     %g1, %o0, %o0
        xor     %g2, -20, %g2
        sethi   %hi(5120), %g3
        add     %o0, %g2, %o0
        sethi   %hi(32768), %o2
        udivx   %o0, %g3, %g3
        sllx    %g3, 2, %g1
        add     %g1, %g3, %g1
        sllx    %g1, 10, %g2
        sllx    %g1, 5, %g1
        sub     %o0, %g2, %o0
        udivx   %o0, 24, %o0
        add     %o0, %o2, %o0
        add     %g1, %o0, %g1
        sllx    %g1, 1, %o1
        mov     %l0, %o0
        add     %o1, %g1, %o1
        mov     %i7, %o2
        call    " #fixup_name "
         sllx   %o1, 3, %o1
        jmp     %o0
         restore
        .size   " #tramp_name "_0, . - " #tramp_name "_0

        .globl  " #tramp_name "_1
        .type   " #tramp_name "_1, @function
        .align  32
" #tramp_name "_1:
        srlx    %g1, 15, %o1
        ldx     [%o0 + 8], %o0
        sllx    %o1, 1, %o3
        add     %o1, %o3, %o1
        mov     %i7, %o2
        call    " #fixup_name "
         sllx   %o1, 3, %o1
        jmp     %o0
         restore
        .size   " #tramp_name "_1, . - " #tramp_name "_1
        .previous");

#ifndef PROF
#define ELF_MACHINE_RUNTIME_TRAMPOLINE                  \
  TRAMPOLINE_TEMPLATE (_dl_runtime_resolve, fixup);     \
  TRAMPOLINE_TEMPLATE (_dl_runtime_profile, profile_fixup);
#else
#define ELF_MACHINE_RUNTIME_TRAMPOLINE                  \
  TRAMPOLINE_TEMPLATE (_dl_runtime_resolve, fixup);     \
  TRAMPOLINE_TEMPLATE (_dl_runtime_profile, fixup);
#endif

/* The PLT uses Elf64_Rela relocs.  */
#define elf_machine_relplt elf_machine_rela

/* 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__ ( "\
        .text
        .global _start
        .type   _start, @function
        .align  32
_start:
   /* Make room for functions to drop their arguments on the stack.  */
        sub     %sp, 6*8, %sp
   /* Pass pointer to argument block to _dl_start.  */
        call    _dl_start
         add     %sp," __S(STACK_BIAS) "+22*8,%o0
        /* FALLTHRU */
        .size _start, .-_start

        .global _dl_start_user
        .type   _dl_start_user, @function
_dl_start_user:
   /* Load the GOT register.  */
1:      call    11f
        sethi   %hi(_GLOBAL_OFFSET_TABLE_-(1b-.)),%l7
11:     or      %l7,%lo(_GLOBAL_OFFSET_TABLE_-(1b-.)),%l7
        add     %l7,%o7,%l7
   /* Save the user entry point address in %l0.  */
        mov     %o0,%l0
  /* Store the highest stack address.  */
        sethi   %hi(__libc_stack_end), %g2
        or      %g2, %lo(__libc_stack_end), %g2
        ldx     [%l7 + %g2], %l1
        add     %sp, 6*8, %l2
        stx     %l2, [%l1]
   /* See if we were run as a command with the executable file name as an
      extra leading argument.  If so, we must shift things around since we
      must keep the stack doubleword aligned.  */
        sethi   %hi(_dl_skip_args), %g2
        or      %g2, %lo(_dl_skip_args), %g2
        ldx     [%l7+%g2], %i0
        ld      [%i0], %i0
        brz,pt  %i0, 2f
         nop
        /* Find out how far to shift.  */
        ldx     [%sp+" __S(STACK_BIAS) "+22*8], %i1
        sub     %i1, %i0, %i1
        sllx    %i0, 3, %i2
        stx     %i1, [%sp+" __S(STACK_BIAS) "+22*8]
        add     %sp, " __S(STACK_BIAS) "+23*8, %i1
        add     %i1, %i2, %i2
        /* Copy down argv.  */
12:     ldx     [%i2], %i3
        add     %i2, 8, %i2
        stx     %i3, [%i1]
        brnz,pt %i3, 12b
         add    %i1, 8, %i1
        /* Copy down envp.  */
13:     ldx     [%i2], %i3
        add     %i2, 8, %i2
        stx     %i3, [%i1]
        brnz,pt %i3, 13b
         add    %i1, 8, %i1
        /* Copy down auxiliary table.  */
14:     ldx     [%i2], %i3
        ldx     [%i2+8], %i4
        add     %i2, 16, %i2
        stx     %i3, [%i1]
        stx     %i4, [%i1+8]
        brnz,pt %i3, 13b
         add    %i1, 16, %i1
  /* Load searchlist of the main object to pass to _dl_init_next.  */
2:      sethi   %hi(_dl_main_searchlist), %g2
        or      %g2, %lo(_dl_main_searchlist), %g2
        ldx     [%l7+%g2], %g2
        ldx     [%g2], %l1
   /* Call _dl_init_next to return the address of an initializer to run.  */
3:      call    _dl_init_next
         mov    %l1, %o0
        brz,pn  %o0, 4f
         nop
        jmpl    %o0, %o7
         sub    %o7, 24, %o7
   /* Clear the startup flag.  */
4:      sethi   %hi(_dl_starting_up), %g2
        or      %g2, %lo(_dl_starting_up), %g2
        ldx     [%l7+%g2], %g2
        st      %g0, [%g2]
   /* Pass our finalizer function to the user in %g1.  */
        sethi   %hi(_dl_fini), %g1
        or      %g1, %lo(_dl_fini), %g1
        ldx     [%l7+%g1], %g1
  /* Jump to the user's entry point and deallocate the extra stack we got.  */
        jmp     %l0
         add    %sp, 6*8, %sp
        .size   _dl_start_user, . - _dl_start_user
        .previous");