/* Machine-dependent ELF dynamic relocation inline functions.  RISC-V version.

   Copyright (C) 2011-2018 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 Lesser General Public

   License as published by the Free Software Foundation; either

   version 2.1 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

   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public

   License along with the GNU C Library.  If not, see

   <http://www.gnu.org/licenses/>.  */

#ifndef dl_machine_h

#define dl_machine_h

#define ELF_MACHINE_NAME "RISC-V"

#include <entry.h>

#include <elf/elf.h>

#include <sys/asm.h>

#include <dl-tls.h>

#ifndef _RTLD_PROLOGUE

# define _RTLD_PROLOGUE(entry)						\

	".globl\t" __STRING (entry) "\n\t"				\

	".type\t" __STRING (entry) ", @function\n"			\

	__STRING (entry) ":\n\t"

#endif

#ifndef _RTLD_EPILOGUE

# define _RTLD_EPILOGUE(entry)						\

	".size\t" __STRING (entry) ", . - " __STRING (entry) "\n\t"

#endif

#define ELF_MACHINE_JMP_SLOT R_RISCV_JUMP_SLOT

#define elf_machine_type_class(type)				\

  ((ELF_RTYPE_CLASS_PLT * ((type) == ELF_MACHINE_JMP_SLOT	\

     || (__WORDSIZE == 32 && (type) == R_RISCV_TLS_DTPREL32)	\

     || (__WORDSIZE == 32 && (type) == R_RISCV_TLS_DTPMOD32)	\

     || (__WORDSIZE == 32 && (type) == R_RISCV_TLS_TPREL32)	\

     || (__WORDSIZE == 64 && (type) == R_RISCV_TLS_DTPREL64)	\

     || (__WORDSIZE == 64 && (type) == R_RISCV_TLS_DTPMOD64)	\

     || (__WORDSIZE == 64 && (type) == R_RISCV_TLS_TPREL64)))	\

   | (ELF_RTYPE_CLASS_COPY * ((type) == R_RISCV_COPY)))

#define ELF_MACHINE_NO_REL 1

#define ELF_MACHINE_NO_RELA 0

/* Return nonzero iff ELF header is compatible with the running host.  */

static inline int __attribute_used__

elf_machine_matches_host (const ElfW(Ehdr) *ehdr)

{

  /* We can only run RISC-V binaries.  */

  if (ehdr->e_machine != EM_RISCV)

    return 0;

  /* Ensure the library's floating-point ABI matches that of the running

     system.  For now we don't support mixing XLEN, so there's no need (or way)

     to check it matches.  */

#ifdef __riscv_float_abi_double

  if ((ehdr->e_flags & EF_RISCV_FLOAT_ABI) != EF_RISCV_FLOAT_ABI_DOUBLE)

    return 0;

#else

  if ((ehdr->e_flags & EF_RISCV_FLOAT_ABI) != EF_RISCV_FLOAT_ABI_SOFT)

    return 0;

#endif

  return 1;

}

/* Return the link-time address of _DYNAMIC.  */

static inline ElfW(Addr)

elf_machine_dynamic (void)

{

  extern ElfW(Addr) _GLOBAL_OFFSET_TABLE_ __attribute__ ((visibility ("hidden")));

  return _GLOBAL_OFFSET_TABLE_;

}

#define STRINGXP(X) __STRING (X)

#define STRINGXV(X) STRINGV_ (X)

#define STRINGV_(...) # __VA_ARGS__

/* Return the run-time load address of the shared object.  */

static inline ElfW(Addr)

elf_machine_load_address (void)

{

  ElfW(Addr) load_addr;

  asm ("lla %0, _DYNAMIC" : "=r" (load_addr));

  return load_addr - elf_machine_dynamic ();

}

/* 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 RTLD_START asm (\

	".text\n\

	" _RTLD_PROLOGUE (ENTRY_POINT) "\

	mv a0, sp\n\

	jal _dl_start\n\

	# Stash user entry point in s0.\n\

	mv s0, a0\n\

	# See if we were run as a command with the executable file\n\

	# name as an extra leading argument.\n\

	lw a0, _dl_skip_args\n\

	# Load the original argument count.\n\

	" STRINGXP (REG_L) " a1, 0(sp)\n\

	# Subtract _dl_skip_args from it.\n\

	sub a1, a1, a0\n\

	# Adjust the stack pointer to skip _dl_skip_args words.\n\

	sll a0, a0, " STRINGXP (PTRLOG) "\n\

	add sp, sp, a0\n\

	# Save back the modified argument count.\n\

	" STRINGXP (REG_S) " a1, 0(sp)\n\

	# Call _dl_init (struct link_map *main_map, int argc, char **argv, char **env) \n\

	" STRINGXP (REG_L) " a0, _rtld_local\n\

	add a2, sp, " STRINGXP (SZREG) "\n\

	sll a3, a1, " STRINGXP (PTRLOG) "\n\

	add a3, a3, a2\n\

	add a3, a3, " STRINGXP (SZREG) "\n\

	# Call the function to run the initializers.\n\

	jal _dl_init\n\

	# Pass our finalizer function to _start.\n\

	lla a0, _dl_fini\n\

	# Jump to the user entry point.\n\

	jr s0\n\

	" _RTLD_EPILOGUE (ENTRY_POINT) "\

	.previous" \

);

/* Names of the architecture-specific auditing callback functions.  */

#define ARCH_LA_PLTENTER riscv_gnu_pltenter

#define ARCH_LA_PLTEXIT riscv_gnu_pltexit

/* Bias .got.plt entry by the offset requested by the PLT header.  */

#define elf_machine_plt_value(map, reloc, value) (value)

static inline ElfW(Addr)

elf_machine_fixup_plt (struct link_map *map, lookup_t t,

		       const ElfW(Sym) *refsym, const ElfW(Sym) *sym,

		       const ElfW(Rela) *reloc,

		       ElfW(Addr) *reloc_addr, ElfW(Addr) value)

{

  return *reloc_addr = value;

}

#endif /* !dl_machine_h */

#ifdef RESOLVE_MAP

/* Perform a relocation described by R_INFO at the location pointed to

   by RELOC_ADDR.  SYM is the relocation symbol specified by R_INFO and

   MAP is the object containing the reloc.  */

auto inline void

__attribute__ ((always_inline))

elf_machine_rela (struct link_map *map, const ElfW(Rela) *reloc,

		  const ElfW(Sym) *sym, const struct r_found_version *version,

		  void *const reloc_addr, int skip_ifunc)

{

  ElfW(Addr) r_info = reloc->r_info;

  const unsigned long int r_type = ELFW (R_TYPE) (r_info);

  ElfW(Addr) *addr_field = (ElfW(Addr) *) reloc_addr;

  const ElfW(Sym) *const __attribute__ ((unused)) refsym = sym;

  struct link_map *sym_map = RESOLVE_MAP (&sym, version, r_type);

  ElfW(Addr) value = 0;

  if (sym_map != NULL)

    value = SYMBOL_ADDRESS (sym_map, sym, true) + reloc->r_addend;

  switch (r_type)

    {

#ifndef RTLD_BOOTSTRAP

    case __WORDSIZE == 64 ? R_RISCV_TLS_DTPMOD64 : R_RISCV_TLS_DTPMOD32:

      if (sym_map)

	*addr_field = sym_map->l_tls_modid;

      break;

    case __WORDSIZE == 64 ? R_RISCV_TLS_DTPREL64 : R_RISCV_TLS_DTPREL32:

      if (sym != NULL)

	*addr_field = TLS_DTPREL_VALUE (sym) + reloc->r_addend;

      break;

    case __WORDSIZE == 64 ? R_RISCV_TLS_TPREL64 : R_RISCV_TLS_TPREL32:

      if (sym != NULL)

	{

	  CHECK_STATIC_TLS (map, sym_map);

	  *addr_field = TLS_TPREL_VALUE (sym_map, sym) + reloc->r_addend;

	}

      break;

    case R_RISCV_COPY:

      {

	if (__glibc_unlikely (sym == NULL))

	  /* This can happen in trace mode if an object could not be

	     found.  */

	  break;

	/* Handle TLS copy relocations.  */

	if (__glibc_unlikely (ELFW (ST_TYPE) (sym->st_info) == STT_TLS))

	  {

	    /* There's nothing to do if the symbol is in .tbss.  */

	    if (__glibc_likely (sym->st_value >= sym_map->l_tls_initimage_size))

	      break;

	    value += (ElfW(Addr)) sym_map->l_tls_initimage - sym_map->l_addr;

	  }

	size_t size = sym->st_size;

	if (__glibc_unlikely (sym->st_size != refsym->st_size))

	  {

	    const char *strtab = (const void *) D_PTR (map, l_info[DT_STRTAB]);

	    if (sym->st_size > refsym->st_size)

	      size = refsym->st_size;

	    if (sym->st_size > refsym->st_size || GLRO(dl_verbose))

	      _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, size);

	break;

      }

#endif

#if !defined RTLD_BOOTSTRAP || !defined HAVE_Z_COMBRELOC

    case R_RISCV_RELATIVE:

      {

# 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.  */

#  ifndef SHARED

	weak_extern (GL(dl_rtld_map));

#  endif

	if (map != &GL(dl_rtld_map)) /* Already done in rtld itself.  */

# endif

	  *addr_field = map->l_addr + reloc->r_addend;

      break;

    }

#endif

    case R_RISCV_JUMP_SLOT:

    case __WORDSIZE == 64 ? R_RISCV_64 : R_RISCV_32:

      *addr_field = value;

      break;

    case R_RISCV_NONE:

      break;

    default:

      _dl_reloc_bad_type (map, r_type, 0);

      break;

    }

}

auto inline void

__attribute__ ((always_inline))

elf_machine_rela_relative (ElfW(Addr) l_addr, const ElfW(Rela) *reloc,

			  void *const reloc_addr)

{

  *(ElfW(Addr) *) reloc_addr = l_addr + reloc->r_addend;

}

auto inline void

__attribute__ ((always_inline))

elf_machine_lazy_rel (struct link_map *map, ElfW(Addr) l_addr,

		      const ElfW(Rela) *reloc, int skip_ifunc)

{

  ElfW(Addr) *const reloc_addr = (void *) (l_addr + reloc->r_offset);

  const unsigned int r_type = ELFW (R_TYPE) (reloc->r_info);

  /* Check for unexpected PLT reloc type.  */

  if (__glibc_likely (r_type == R_RISCV_JUMP_SLOT))

    {

      if (__glibc_unlikely (map->l_mach.plt == 0))

	{

	  if (l_addr)

	    *reloc_addr += l_addr;

	}

      else

	*reloc_addr = map->l_mach.plt;

    }

  else

    _dl_reloc_bad_type (map, r_type, 1);

}

/* Set up the loaded object described by L so its stub function

   will jump to the on-demand fixup code __dl_runtime_resolve.  */

auto inline int

__attribute__ ((always_inline))

elf_machine_runtime_setup (struct link_map *l, int lazy, int profile)

{

#ifndef RTLD_BOOTSTRAP

  /* If using PLTs, fill in the first two entries of .got.plt.  */

  if (l->l_info[DT_JMPREL])

    {

      extern void _dl_runtime_resolve (void) __attribute__ ((visibility ("hidden")));

      ElfW(Addr) *gotplt = (ElfW(Addr) *) D_PTR (l, l_info[DT_PLTGOT]);

      /* If a library is prelinked but we have to relocate anyway,

	 we have to be able to undo the prelinking of .got.plt.

	 The prelinker saved the address of .plt for us here.  */

      if (gotplt[1])

	l->l_mach.plt = gotplt[1] + l->l_addr;

      gotplt[0] = (ElfW(Addr)) &_dl_runtime_resolve;

      gotplt[1] = (ElfW(Addr)) l;

    }

#endif

  return lazy;

}

#endif /* RESOLVE_MAP */