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/* Machine-dependent ELF dynamic relocation inline functions.  MIPS version.
   Copyright (C) 1996-2001, 2002, 2003, 2004, 2005, 2006, 2007
   Free Software Foundation, Inc.
   This file is part of the GNU C Library.
   Contributed by Kazumoto Kojima <kkojima@info.kanagawa-u.ac.jp>.
 
   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, write to the Free
   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   02111-1307 USA.  */
 
/*  FIXME: Profiling of shared libraries is not implemented yet.  */
#ifndef dl_machine_h
#define dl_machine_h
 
#define ELF_MACHINE_NAME "RISC-V"
#define EM_RISCV 243
 
/* Relocs. */
#define R_RISCV_NONE          0
#define R_RISCV_32            1
#define R_RISCV_64            2
#define R_RISCV_RELATIVE      3
#define R_RISCV_COPY          4
#define R_RISCV_JUMP_SLOT     5
#define R_RISCV_TLS_DTPMOD32  6
#define R_RISCV_TLS_DTPMOD64  7
#define R_RISCV_TLS_DTPREL32  8
#define R_RISCV_TLS_DTPREL64  9
#define R_RISCV_TLS_TPREL32  10
#define R_RISCV_TLS_TPREL64  11
 
#include <entry.h>
 
#ifndef ENTRY_POINT
#error ENTRY_POINT needs to be defined for MIPS.
#endif
 
#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
 
/* A reloc type used for ld.so cmdline arg lookups to reject PLT entries.
   This only makes sense on MIPS when using PLTs, so choose the
   PLT relocation (not encountered when not using PLTs).  */
#define ELF_MACHINE_JMP_SLOT			R_RISCV_JUMP_SLOT
#define elf_machine_type_class(type)				\
  ((ELF_RTYPE_CLASS_PLT * ((type) == ELF_MACHINE_JMP_SLOT	\
     || (_RISCV_SZPTR == 32 && (type) == R_RISCV_TLS_DTPREL32)	\
     || (_RISCV_SZPTR == 32 && (type) == R_RISCV_TLS_DTPMOD32)	\
     || (_RISCV_SZPTR == 32 && (type) == R_RISCV_TLS_TPREL32)	\
     || (_RISCV_SZPTR == 64 && (type) == R_RISCV_TLS_DTPREL64)	\
     || (_RISCV_SZPTR == 64 && (type) == R_RISCV_TLS_DTPMOD64)	\
     || (_RISCV_SZPTR == 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)
{
  return ehdr->e_machine == EM_RISCV;
}
 
/* 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) "\
	move a0, sp\n\
	jal _dl_start\n\
	# Stash user entry point in s0.\n\
	move 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.  */
# ifdef __riscv64
#  define ARCH_LA_PLTENTER mips_n64_gnu_pltenter
#  define ARCH_LA_PLTEXIT mips_n64_gnu_pltexit
# else
#  define ARCH_LA_PLTENTER mips_n32_gnu_pltenter
#  define ARCH_LA_PLTEXIT mips_n32_gnu_pltexit
# endif
 
/* Bias .got.plt entry by the offset requested by the PLT header. */
#define elf_machine_plt_value(map, reloc, value) (value)
#define elf_machine_fixup_plt(map, t, reloc, reloc_addr, value) \
  (*(ElfW(Addr) *)(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 = sym_map->l_addr + sym->st_value + 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 (__builtin_expect (sym == NULL, 0))
	  /* 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 (__builtin_expect (sym->st_size != refsym->st_size, 0))
	  {
	    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 (__builtin_expect (r_type == R_RISCV_JUMP_SLOT, 1))
    {
      if (__builtin_expect (map->l_mach.plt, 0) == 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 */