glibc/sysdeps/powerpc/powerpc64/dl-machine.h

/* Machine-dependent ELF dynamic relocation inline functions.
   PowerPC64 version.
   Copyright 1995-2023 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, see <https://www.gnu.org/licenses/>.  */

#ifndef dl_machine_h
#define dl_machine_h

#define ELF_MACHINE_NAME "powerpc64"

#include <assert.h>
#include <sys/param.h>
#include <dl-tls.h>
#include <sysdep.h>
#include <hwcapinfo.h>
#include <cpu-features.c>
#include <dl-static-tls.h>
#include <dl-funcdesc.h>
#include <dl-machine-rel.h>

/* Translate a processor specific dynamic tag to the index
   in l_info array.  */
#define DT_PPC64(x) (DT_PPC64_##x - DT_LOPROC + DT_NUM)

#define ELF_MULT_MACHINES_SUPPORTED

/* Return nonzero iff ELF header is compatible with the running host.  */
static inline int
elf_machine_matches_host (const Elf64_Ehdr *ehdr)
{
  /* Verify that the binary matches our ABI version.  */
  if ((ehdr->e_flags & EF_PPC64_ABI) != 0)
    {
#if _CALL_ELF != 2
      if ((ehdr->e_flags & EF_PPC64_ABI) != 1)
        return 0;
#else
      if ((ehdr->e_flags & EF_PPC64_ABI) != 2)
        return 0;
#endif
    }

  return ehdr->e_machine == EM_PPC64;
}

/* Return nonzero iff ELF header is compatible with the running host,
   but not this loader.  */
static inline int
elf_host_tolerates_machine (const Elf64_Ehdr *ehdr)
{
  return ehdr->e_machine == EM_PPC;
}

/* Return nonzero iff ELF header is compatible with the running host,
   but not this loader.  */
static inline int
elf_host_tolerates_class (const Elf64_Ehdr *ehdr)
{
  return ehdr->e_ident[EI_CLASS] == ELFCLASS32;
}


/* Return the run-time load address of the shared object, assuming it
   was originally linked at zero.  */
static inline Elf64_Addr
elf_machine_load_address (void) __attribute__ ((const));

static inline Elf64_Addr
elf_machine_load_address (void)
{
  Elf64_Addr ret;

  /* The first entry in .got (and thus the first entry in .toc) is the
     link-time TOC_base, ie. r2.  So the difference between that and
     the current r2 set by the kernel is how far the shared lib has
     moved.  */
  asm (	"	ld	%0,-32768(2)\n"
	"	subf	%0,%0,2\n"
	: "=r"	(ret));
  return ret;
}

/* Return the link-time address of _DYNAMIC.  */
static inline Elf64_Addr
elf_machine_dynamic (void)
{
  Elf64_Addr runtime_dynamic;
  /* It's easier to get the run-time address.  */
  asm (	"	addis	%0,2,_DYNAMIC@toc@ha\n"
	"	addi	%0,%0,_DYNAMIC@toc@l\n"
	: "=b"	(runtime_dynamic));
  /* Then subtract off the load address offset.  */
  return runtime_dynamic - elf_machine_load_address() ;
}

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


#ifdef HAVE_INLINED_SYSCALLS
/* We do not need _dl_starting_up.  */
# define DL_STARTING_UP_DEF
#else
# define DL_STARTING_UP_DEF \
".LC__dl_starting_up:\n"  \
"	.tc __GI__dl_starting_up[TC],__GI__dl_starting_up\n"
#endif


/* 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 (".pushsection \".text\"\n"					\
"	.align	2\n"							\
"	" ENTRY_2(_start) "\n"						\
BODY_PREFIX "_start:\n"							\
"	" LOCALENTRY(_start) "\n"						\
/* We start with the following on the stack, from top:			\
   argc (4 bytes);							\
   arguments for program (terminated by NULL);				\
   environment variables (terminated by NULL);				\
   arguments for the program loader.  */				\
"	mr	3,1\n"							\
"	li	4,0\n"							\
"	stdu	4,-128(1)\n"						\
/* Call _dl_start with one parameter pointing at argc.  */		\
"	bl	" DOT_PREFIX "_dl_start\n"				\
"	nop\n"								\
/* Transfer control to _dl_start_user!  */				\
"	b	" DOT_PREFIX "_dl_start_user\n"				\
".LT__start:\n"								\
"	.long 0\n"							\
"	.byte 0x00,0x0c,0x24,0x40,0x00,0x00,0x00,0x00\n"		\
"	.long .LT__start-" BODY_PREFIX "_start\n"			\
"	.short .LT__start_name_end-.LT__start_name_start\n"		\
".LT__start_name_start:\n"						\
"	.ascii \"_start\"\n"						\
".LT__start_name_end:\n"						\
"	.align 2\n"							\
"	" END_2(_start) "\n"						\
"	.pushsection	\".toc\",\"aw\"\n"				\
DL_STARTING_UP_DEF							\
".LC__rtld_local:\n"							\
"	.tc _rtld_local[TC],_rtld_local\n"				\
".LC__dl_argc:\n"							\
"	.tc _dl_argc[TC],_dl_argc\n"					\
".LC__dl_argv:\n"							\
"	.tc __GI__dl_argv[TC],__GI__dl_argv\n"				\
".LC__dl_fini:\n"							\
"	.tc _dl_fini[TC],_dl_fini\n"					\
"	.popsection\n"							\
"	" ENTRY_2(_dl_start_user) "\n"					\
/* Now, we do our main work of calling initialisation procedures.	\
   The ELF ABI doesn't say anything about parameters for these,		\
   so we just pass argc, argv, and the environment.			\
   Changing these is strongly discouraged (not least because argc is	\
   passed by value!).  */						\
BODY_PREFIX "_dl_start_user:\n"						\
"	" LOCALENTRY(_dl_start_user) "\n"				\
/* the address of _start in r30.  */					\
"	mr	30,3\n"							\
/* &_dl_argc in 29, &_dl_argv in 27, and _dl_loaded in 28.  */		\
"	addis	28,2,.LC__rtld_local@toc@ha\n"				\
"	ld	28,.LC__rtld_local@toc@l(28)\n"				\
"	addis	29,2,.LC__dl_argc@toc@ha\n"				\
"	ld	29,.LC__dl_argc@toc@l(29)\n"				\
"	addis	27,2,.LC__dl_argv@toc@ha\n"				\
"	ld	27,.LC__dl_argv@toc@l(27)\n"				\
/* _dl_init (_dl_loaded, _dl_argc, _dl_argv, _dl_argv+_dl_argc+1).  */	\
"	ld	3,0(28)\n"						\
"	lwa	4,0(29)\n"						\
"	ld	5,0(27)\n"						\
"	sldi	6,4,3\n"						\
"	add	6,5,6\n"						\
"	addi	6,6,8\n"						\
"	bl	" DOT_PREFIX "_dl_init\n"				\
"	nop\n"								\
/* Now, to conform to the ELF ABI, we have to:				\
   Pass argc (actually _dl_argc) in r3;  */				\
"	lwa	3,0(29)\n"						\
/* Pass argv (actually _dl_argv) in r4;  */				\
"	ld	4,0(27)\n"						\
/* Pass argv+argc+1 in r5;  */						\
"	sldi	5,3,3\n"						\
"	add	6,4,5\n"						\
"	addi	5,6,8\n"						\
/* Pass the auxiliary vector in r6. This is passed to us just after	\
   _envp.  */								\
"2:	ldu	0,8(6)\n"						\
"	cmpdi	0,0\n"							\
"	bne	2b\n"							\
"	addi	6,6,8\n"						\
/* Pass a termination function pointer (in this case _dl_fini) in	\
   r7.  */								\
"	addis	7,2,.LC__dl_fini@toc@ha\n"				\
"	ld	7,.LC__dl_fini@toc@l(7)\n"				\
/* Pass the stack pointer in r1 (so far so good), pointing to a NULL	\
   value.  This lets our startup code distinguish between a program	\
   linked statically, which linux will call with argc on top of the	\
   stack which will hopefully never be zero, and a dynamically linked	\
   program which will always have a NULL on the top of the stack.	\
   Take the opportunity to clear LR, so anyone who accidentally		\
   returns from _start gets SEGV.  Also clear the next few words of	\
   the stack.  */							\
"	li	31,0\n"							\
"	std	31,0(1)\n"						\
"	mtlr	31\n"							\
"	std	31,8(1)\n"						\
"	std	31,16(1)\n"						\
"	std	31,24(1)\n"						\
/* Now, call the start function descriptor at r30...  */		\
"	.globl	._dl_main_dispatch\n"					\
"._dl_main_dispatch:\n"							\
"	" PPC64_LOAD_FUNCPTR(30) "\n"					\
"	bctr\n"								\
".LT__dl_start_user:\n"							\
"	.long 0\n"							\
"	.byte 0x00,0x0c,0x24,0x40,0x00,0x00,0x00,0x00\n"		\
"	.long .LT__dl_start_user-" BODY_PREFIX "_dl_start_user\n"	\
"	.short .LT__dl_start_user_name_end-.LT__dl_start_user_name_start\n" \
".LT__dl_start_user_name_start:\n"					\
"	.ascii \"_dl_start_user\"\n"					\
".LT__dl_start_user_name_end:\n"					\
"	.align 2\n"							\
"	" END_2(_dl_start_user) "\n"					\
"	.popsection");

/* ELF_RTYPE_CLASS_COPY iff TYPE should not be allowed to resolve to
   one of the main executable's symbols, as for a COPY reloc.

   To make function pointer comparisons work on most targets, the
   relevant ABI states that the address of a non-local function in a
   dynamically linked executable is the address of the PLT entry for
   that function.  This is quite reasonable since using the real
   function address in a non-PIC executable would typically require
   dynamic relocations in .text, something to be avoided.  For such
   functions, the linker emits a SHN_UNDEF symbol in the executable
   with value equal to the PLT entry address.  Normally, SHN_UNDEF
   symbols have a value of zero, so this is a clue to ld.so that it
   should treat these symbols specially.  For relocations not in
   ELF_RTYPE_CLASS_PLT (eg. those on function pointers), ld.so should
   use the value of the executable SHN_UNDEF symbol, ie. the PLT entry
   address.  For relocations in ELF_RTYPE_CLASS_PLT (eg. the relocs in
   the PLT itself), ld.so should use the value of the corresponding
   defined symbol in the object that defines the function, ie. the
   real function address.  This complicates ld.so in that there are
   now two possible values for a given symbol, and it gets even worse
   because protected symbols need yet another set of rules.

   On PowerPC64 we don't need any of this.  The linker won't emit
   SHN_UNDEF symbols with non-zero values.  ld.so can make all
   relocations behave "normally", ie. always use the real address
   like PLT relocations.  So always set ELF_RTYPE_CLASS_PLT.  */

#if _CALL_ELF != 2
#define elf_machine_type_class(type) \
  (ELF_RTYPE_CLASS_PLT | (((type) == R_PPC64_COPY) * ELF_RTYPE_CLASS_COPY))
#else
/* And now that you have read that large comment, you can disregard it
   all for ELFv2.  ELFv2 does need the special SHN_UNDEF treatment.  */
#define IS_PPC64_TLS_RELOC(R)						\
  (((R) >= R_PPC64_TLS && (R) <= R_PPC64_DTPREL16_HIGHESTA)		\
   || ((R) >= R_PPC64_TPREL16_HIGH && (R) <= R_PPC64_DTPREL16_HIGHA))

#define elf_machine_type_class(type) \
  ((((type) == R_PPC64_JMP_SLOT					\
     || (type) == R_PPC64_ADDR24				\
     || IS_PPC64_TLS_RELOC (type)) * ELF_RTYPE_CLASS_PLT)	\
   | (((type) == R_PPC64_COPY) * ELF_RTYPE_CLASS_COPY))
#endif

/* A reloc type used for ld.so cmdline arg lookups to reject PLT entries.  */
#define ELF_MACHINE_JMP_SLOT	R_PPC64_JMP_SLOT

/* We define an initialization function to initialize HWCAP/HWCAP2 and
   platform data so it can be copied into the TCB later.  This is called
   very early in _dl_sysdep_start for dynamically linked binaries.  */
#if defined(SHARED) && IS_IN (rtld)
# define DL_PLATFORM_INIT dl_platform_init ()

static inline void __attribute__ ((unused))
dl_platform_init (void)
{
  __tcb_parse_hwcap_and_convert_at_platform ();
  init_cpu_features (&GLRO(dl_powerpc_cpu_features));
}
#endif

/* Stuff for the PLT.  */
#if _CALL_ELF != 2
#define PLT_INITIAL_ENTRY_WORDS 3
#define PLT_ENTRY_WORDS 3
#define GLINK_INITIAL_ENTRY_WORDS 8
/* The first 32k entries of glink can set an index and branch using two
   instructions; past that point, glink uses three instructions.  */
#define GLINK_ENTRY_WORDS(I) (((I) < 0x8000)? 2 : 3)
#else
#define PLT_INITIAL_ENTRY_WORDS 2
#define PLT_ENTRY_WORDS 1
#define GLINK_INITIAL_ENTRY_WORDS 8
#define GLINK_ENTRY_WORDS(I) 1
#endif

#define PPC_DCBST(where) asm volatile ("dcbst 0,%0" : : "r"(where) : "memory")
#define PPC_DCBT(where) asm volatile ("dcbt 0,%0" : : "r"(where) : "memory")
#define PPC_DCBF(where) asm volatile ("dcbf 0,%0" : : "r"(where) : "memory")
#define PPC_SYNC asm volatile ("sync" : : : "memory")
#define PPC_ISYNC asm volatile ("sync; isync" : : : "memory")
#define PPC_ICBI(where) asm volatile ("icbi 0,%0" : : "r"(where) : "memory")
#define PPC_DIE asm volatile ("tweq 0,0")
/* Use this when you've modified some code, but it won't be in the
   instruction fetch queue (or when it doesn't matter if it is). */
#define MODIFIED_CODE_NOQUEUE(where) \
     do { PPC_DCBST(where); PPC_SYNC; PPC_ICBI(where); } while (0)
/* Use this when it might be in the instruction queue. */
#define MODIFIED_CODE(where) \
     do { PPC_DCBST(where); PPC_SYNC; PPC_ICBI(where); PPC_ISYNC; } while (0)

/* Set up the loaded object described by MAP so its unrelocated PLT
   entries will jump to the on-demand fixup code in dl-runtime.c.  */
static inline int __attribute__ ((always_inline))
elf_machine_runtime_setup (struct link_map *map, struct r_scope_elem *scope[],
			   int lazy, int profile)
{
  if (map->l_info[DT_JMPREL])
    {
      Elf64_Word i;
      Elf64_Word *glink = NULL;
      Elf64_Xword *plt = (Elf64_Xword *) D_PTR (map, l_info[DT_PLTGOT]);
      Elf64_Word num_plt_entries = (map->l_info[DT_PLTRELSZ]->d_un.d_val
				    / sizeof (Elf64_Rela));
      Elf64_Addr l_addr = map->l_addr;
      Elf64_Dyn **info = map->l_info;
      char *p;

      extern void _dl_runtime_resolve (void);
      extern void _dl_profile_resolve (void);

      /* Relocate the DT_PPC64_GLINK entry in the _DYNAMIC section.
	 elf_get_dynamic_info takes care of the standard entries but
	 doesn't know exactly what to do with processor specific
	 entries.  */
      if (info[DT_PPC64(GLINK)] != NULL)
	info[DT_PPC64(GLINK)]->d_un.d_ptr += l_addr;

      if (lazy)
	{
	  Elf64_Word glink_offset;
	  Elf64_Word offset;
	  Elf64_Addr dlrr;

	  dlrr = (Elf64_Addr) (profile ? _dl_profile_resolve
				       : _dl_runtime_resolve);
	  if (profile && GLRO(dl_profile) != NULL
	      && _dl_name_match_p (GLRO(dl_profile), map))
	    /* This is the object we are looking for.  Say that we really
	       want profiling and the timers are started.  */
	    GL(dl_profile_map) = map;

#if _CALL_ELF != 2
	  /* We need to stuff the address/TOC of _dl_runtime_resolve
	     into doublewords 0 and 1 of plt_reserve.  Then we need to
	     stuff the map address into doubleword 2 of plt_reserve.
	     This allows the GLINK0 code to transfer control to the
	     correct trampoline which will transfer control to fixup
	     in dl-machine.c.  */
	  {
	    /* The plt_reserve area is the 1st 3 doublewords of the PLT.  */
	    Elf64_FuncDesc *plt_reserve = (Elf64_FuncDesc *) plt;
	    Elf64_FuncDesc *resolve_fd = (Elf64_FuncDesc *) dlrr;
	    plt_reserve->fd_func = resolve_fd->fd_func;
	    plt_reserve->fd_toc  = resolve_fd->fd_toc;
	    plt_reserve->fd_aux  = (Elf64_Addr) map;
#ifdef RTLD_BOOTSTRAP
	    /* When we're bootstrapping, the opd entry will not have
	       been relocated yet.  */
	    plt_reserve->fd_func += l_addr;
	    plt_reserve->fd_toc  += l_addr;
#endif
	  }
#else
	  /* When we don't have function descriptors, the first doubleword
	     of the PLT holds the address of _dl_runtime_resolve, and the
	     second doubleword holds the map address.  */
	  plt[0] = dlrr;
	  plt[1] = (Elf64_Addr) map;
#endif

	  /* Set up the lazy PLT entries.  */
	  glink = (Elf64_Word *) D_PTR (map, l_info[DT_PPC64(GLINK)]);
	  offset = PLT_INITIAL_ENTRY_WORDS;
	  glink_offset = GLINK_INITIAL_ENTRY_WORDS;
	  for (i = 0; i < num_plt_entries; i++)
	    {

	      plt[offset] = (Elf64_Xword) &glink[glink_offset];
	      offset += PLT_ENTRY_WORDS;
	      glink_offset += GLINK_ENTRY_WORDS (i);
	    }

	  /* Now, we've modified data.  We need to write the changes from
	     the data cache to a second-level unified cache, then make
	     sure that stale data in the instruction cache is removed.
	     (In a multiprocessor system, the effect is more complex.)
	     Most of the PLT shouldn't be in the instruction cache, but
	     there may be a little overlap at the start and the end.

	     Assumes that dcbst and icbi apply to lines of 16 bytes or
	     more.  Current known line sizes are 16, 32, and 128 bytes.  */

	  for (p = (char *) plt; p < (char *) &plt[offset]; p += 16)
	    PPC_DCBST (p);
	  PPC_SYNC;
	}
    }
  return lazy;
}

#if _CALL_ELF == 2
extern void attribute_hidden _dl_error_localentry (struct link_map *map,
						   const Elf64_Sym *refsym);

/* If the PLT entry resolves to a function in the same object, return
   the target function's local entry point offset if usable.  */
static inline Elf64_Addr __attribute__ ((always_inline))
ppc64_local_entry_offset (struct link_map *map, lookup_t sym_map,
			  const ElfW(Sym) *refsym, const ElfW(Sym) *sym)
{
  /* If the target function is in a different object, we cannot
     use the local entry point.  */
  if (sym_map != map)
    {
      /* Check that optimized plt call stubs for localentry:0 functions
	 are not being satisfied by a non-zero localentry symbol.  */
      if (map->l_info[DT_PPC64(OPT)]
	  && (map->l_info[DT_PPC64(OPT)]->d_un.d_val & PPC64_OPT_LOCALENTRY) != 0
	  && refsym->st_info == ELFW(ST_INFO) (STB_GLOBAL, STT_FUNC)
	  && (STO_PPC64_LOCAL_MASK & refsym->st_other) == 0
	  && (STO_PPC64_LOCAL_MASK & sym->st_other) != 0)
	_dl_error_localentry (map, refsym);

      return 0;
    }

  /* If the linker inserted multiple TOCs, we cannot use the
     local entry point.  */
  if (map->l_info[DT_PPC64(OPT)]
      && (map->l_info[DT_PPC64(OPT)]->d_un.d_val & PPC64_OPT_MULTI_TOC))
    return 0;

  /* If the target function is an ifunc then the local entry offset is
     for the resolver, not the final destination.  */
  if (__builtin_expect (ELFW(ST_TYPE) (sym->st_info) == STT_GNU_IFUNC, 0))
    return 0;

  /* Otherwise, we can use the local entry point.  Retrieve its offset
     from the symbol's ELF st_other field.  */
  return PPC64_LOCAL_ENTRY_OFFSET (sym->st_other);
}
#endif

/* Change the PLT entry whose reloc is 'reloc' to call the actual
   routine.  */
static inline Elf64_Addr __attribute__ ((always_inline))
elf_machine_fixup_plt (struct link_map *map, lookup_t sym_map,
		       const ElfW(Sym) *refsym, const ElfW(Sym) *sym,
		       const Elf64_Rela *reloc,
		       Elf64_Addr *reloc_addr, Elf64_Addr finaladdr)
{
#if _CALL_ELF != 2
  Elf64_FuncDesc *plt = (Elf64_FuncDesc *) reloc_addr;
  Elf64_FuncDesc *rel = (Elf64_FuncDesc *) finaladdr;
  Elf64_Addr offset = 0;
  Elf64_FuncDesc zero_fd = {0, 0, 0};

  PPC_DCBT (&plt->fd_aux);
  PPC_DCBT (&plt->fd_func);

  /* If sym_map is NULL, it's a weak undefined sym;  Set the plt to
     zero.  finaladdr should be zero already in this case, but guard
     against invalid plt relocations with non-zero addends.  */
  if (sym_map == NULL)
    finaladdr = 0;

  /* Don't die here if finaladdr is zero, die if this plt entry is
     actually called.  Makes a difference when LD_BIND_NOW=1.
     finaladdr may be zero for a weak undefined symbol, or when an
     ifunc resolver returns zero.  */
  if (finaladdr == 0)
    rel = &zero_fd;
  else
    {
      PPC_DCBT (&rel->fd_aux);
      PPC_DCBT (&rel->fd_func);
    }

  /* If the opd entry is not yet relocated (because it's from a shared
     object that hasn't been processed yet), then manually reloc it.  */
  if (finaladdr != 0 && map != sym_map && !sym_map->l_relocated
#if !defined RTLD_BOOTSTRAP && defined SHARED
      /* Bootstrap map doesn't have l_relocated set for it.  */
      && sym_map != &GL(dl_rtld_map)
#endif
      )
    offset = sym_map->l_addr;

  /* For PPC64, fixup_plt copies the function descriptor from opd
     over the corresponding PLT entry.
     Initially, PLT Entry[i] is set up for lazy linking, or is zero.
     For lazy linking, the fd_toc and fd_aux entries are irrelevant,
     so for thread safety we write them before changing fd_func.  */

  plt->fd_aux = rel->fd_aux + offset;
  plt->fd_toc = rel->fd_toc + offset;
  PPC_DCBF (&plt->fd_toc);
  PPC_ISYNC;

  plt->fd_func = rel->fd_func + offset;
  PPC_DCBST (&plt->fd_func);
  PPC_ISYNC;
#else
  finaladdr += ppc64_local_entry_offset (map, sym_map, refsym, sym);
  *reloc_addr = finaladdr;
#endif

  return finaladdr;
}

/* 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;
}


/* Names of the architecture-specific auditing callback functions.  */
#if _CALL_ELF != 2
#define ARCH_LA_PLTENTER ppc64_gnu_pltenter
#define ARCH_LA_PLTEXIT ppc64_gnu_pltexit
#else
#define ARCH_LA_PLTENTER ppc64v2_gnu_pltenter
#define ARCH_LA_PLTEXIT ppc64v2_gnu_pltexit
#endif

#if ENABLE_STATIC_PIE && !defined SHARED && !IS_IN (rtld)
#include <libc-diag.h>
#include <tcb-offsets.h>

/* Set up r13 for _dl_relocate_static_pie so that libgcc ifuncs that
   normally access the tcb copy of hwcap will see __tcb.hwcap.  */

static inline void __attribute__ ((always_inline))
ppc_init_fake_thread_pointer (void)
{
  DIAG_PUSH_NEEDS_COMMENT;
  /* We are playing pointer tricks.  Silence gcc warning.  */
  DIAG_IGNORE_NEEDS_COMMENT (4.9, "-Warray-bounds");
  __thread_register = (char *) &__tcb.hwcap - TCB_HWCAP;
  DIAG_POP_NEEDS_COMMENT;
}

#define ELF_MACHINE_BEFORE_RTLD_RELOC(map, dynamic_info) \
  ppc_init_fake_thread_pointer ();
#endif /* ENABLE_STATIC_PIE && !defined SHARED && !IS_IN (rtld) */

#endif /* dl_machine_h */

#ifdef RESOLVE_MAP

#define PPC_LO(v) ((v) & 0xffff)
#define PPC_HI(v) (((v) >> 16) & 0xffff)
#define PPC_HA(v) PPC_HI ((v) + 0x8000)
#define PPC_HIGHER(v) (((v) >> 32) & 0xffff)
#define PPC_HIGHERA(v) PPC_HIGHER ((v) + 0x8000)
#define PPC_HIGHEST(v) (((v) >> 48) & 0xffff)
#define PPC_HIGHESTA(v) PPC_HIGHEST ((v) + 0x8000)
#define BIT_INSERT(var, val, mask) \
  ((var) = ((var) & ~(Elf64_Addr) (mask)) | ((val) & (mask)))

#define dont_expect(X) __builtin_expect ((X), 0)

extern void attribute_hidden _dl_reloc_overflow (struct link_map *map,
						 const char *name,
						 Elf64_Addr *const reloc_addr,
						 const Elf64_Sym *refsym);

static 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;
}

/* This computes the value used by TPREL* relocs.  */
static inline Elf64_Addr __attribute__ ((always_inline, const))
elf_machine_tprel (struct link_map *map,
		   struct link_map *sym_map,
		   const Elf64_Sym *sym,
		   const Elf64_Rela *reloc)
{
#ifndef RTLD_BOOTSTRAP
  if (sym_map)
    {
      CHECK_STATIC_TLS (map, sym_map);
#endif
      return TLS_TPREL_VALUE (sym_map, sym, reloc);
#ifndef RTLD_BOOTSTRAP
    }
#endif
  return 0;
}

/* Call function at address VALUE (an OPD entry) to resolve ifunc relocs.  */
static inline Elf64_Addr __attribute__ ((always_inline))
resolve_ifunc (Elf64_Addr value,
	       const struct link_map *map, const struct link_map *sym_map)
{
#if _CALL_ELF != 2
  /* The function we are calling may not yet have its opd entry relocated.  */
  Elf64_FuncDesc opd;
  if (map != sym_map
# if !defined RTLD_BOOTSTRAP && defined SHARED
      /* Bootstrap map doesn't have l_relocated set for it.  */
      && sym_map != &GL(dl_rtld_map)
# endif
      && !sym_map->l_relocated)
    {
      Elf64_FuncDesc *func = (Elf64_FuncDesc *) value;
      opd.fd_func = func->fd_func + sym_map->l_addr;
      opd.fd_toc = func->fd_toc + sym_map->l_addr;
      opd.fd_aux = func->fd_aux;
      /* GCC 4.9+ eliminates the branch as dead code, force the odp set
         dependency.  */
      asm ("" : "=r" (value) : "0" (&opd), "X" (opd));
    }
#endif
  return ((Elf64_Addr (*) (unsigned long int)) value) (GLRO(dl_hwcap));
}

/* Perform the relocation specified by RELOC and SYM (which is fully
   resolved).  MAP is the object containing the reloc.  */
static inline void __attribute__ ((always_inline))
elf_machine_rela (struct link_map *map, struct r_scope_elem *scope[],
		  const Elf64_Rela *reloc,
		  const Elf64_Sym *sym,
		  const struct r_found_version *version,
		  void *const reloc_addr_arg,
		  int skip_ifunc)
{
  Elf64_Addr *const reloc_addr = reloc_addr_arg;
  const int r_type = ELF64_R_TYPE (reloc->r_info);
  const Elf64_Sym *const refsym = sym;
  union unaligned
    {
      uint16_t u2;
      uint32_t u4;
      uint64_t u8;
    } __attribute__ ((__packed__));

  if (r_type == R_PPC64_RELATIVE)
    {
      *reloc_addr = map->l_addr + reloc->r_addend;
      return;
    }

  if (__glibc_unlikely (r_type == R_PPC64_NONE))
    return;

  /* We need SYM_MAP even in the absence of TLS, for elf_machine_fixup_plt
     and STT_GNU_IFUNC.  */
  struct link_map *sym_map = RESOLVE_MAP (map, scope, &sym, version, r_type);
  Elf64_Addr value = SYMBOL_ADDRESS (sym_map, sym, true) + reloc->r_addend;

  if (sym != NULL
      && __builtin_expect (ELFW(ST_TYPE) (sym->st_info) == STT_GNU_IFUNC, 0)
      && __builtin_expect (sym->st_shndx != SHN_UNDEF, 1)
      && __builtin_expect (!skip_ifunc, 1))
    value = resolve_ifunc (value, map, sym_map);

  /* For relocs that don't edit code, return.
     For relocs that might edit instructions, break from the switch.  */
  switch (r_type)
    {
    case R_PPC64_ADDR64:
    case R_PPC64_GLOB_DAT:
      *reloc_addr = value;
      return;

    case R_PPC64_IRELATIVE:
      if (__glibc_likely (!skip_ifunc))
	value = resolve_ifunc (value, map, sym_map);
      *reloc_addr = value;
      return;

    case R_PPC64_JMP_IREL:
      if (__glibc_likely (!skip_ifunc))
	value = resolve_ifunc (value, map, sym_map);
      /* Fall thru */
    case R_PPC64_JMP_SLOT:
      elf_machine_fixup_plt (map, sym_map, refsym, sym,
			     reloc, reloc_addr, value);
      return;

    case R_PPC64_DTPMOD64:
      if (map->l_info[DT_PPC64(OPT)]
	  && (map->l_info[DT_PPC64(OPT)]->d_un.d_val & PPC64_OPT_TLS))
	{
#ifdef RTLD_BOOTSTRAP
	  reloc_addr[0] = 0;
	  reloc_addr[1] = (sym_map->l_tls_offset - TLS_TP_OFFSET
			   + TLS_DTV_OFFSET);
	  return;
#else
	  if (sym_map != NULL)
	    {
# ifndef SHARED
	      CHECK_STATIC_TLS (map, sym_map);
# else
	      if (TRY_STATIC_TLS (map, sym_map))
# endif
		{
		  reloc_addr[0] = 0;
		  /* Set up for local dynamic.  */
		  reloc_addr[1] = (sym_map->l_tls_offset - TLS_TP_OFFSET
				   + TLS_DTV_OFFSET);
		  return;
		}
	    }
#endif
	}
#ifdef RTLD_BOOTSTRAP
      /* During startup the dynamic linker is always index 1.  */
      *reloc_addr = 1;
#else
      /* Get the information from the link map returned by the
	 resolve function.  */
      if (sym_map != NULL)
	*reloc_addr = sym_map->l_tls_modid;
#endif
      return;

    case R_PPC64_DTPREL64:
      if (map->l_info[DT_PPC64(OPT)]
	  && (map->l_info[DT_PPC64(OPT)]->d_un.d_val & PPC64_OPT_TLS))
	{
#ifdef RTLD_BOOTSTRAP
	  *reloc_addr = TLS_TPREL_VALUE (sym_map, sym, reloc);
	  return;
#else
	  if (sym_map != NULL)
	    {
	      /* This reloc is always preceded by R_PPC64_DTPMOD64.  */
# ifndef SHARED
	      assert (HAVE_STATIC_TLS (map, sym_map));
# else
	      if (HAVE_STATIC_TLS (map, sym_map))
#  endif
		{
		  *reloc_addr = TLS_TPREL_VALUE (sym_map, sym, reloc);
		  return;
		}
	    }
#endif
	}
      /* During relocation all TLS symbols are defined and used.
	 Therefore the offset is already correct.  */
#ifndef RTLD_BOOTSTRAP
      if (sym_map != NULL)
	*reloc_addr = TLS_DTPREL_VALUE (sym, reloc);
#endif
      return;

    case R_PPC64_TPREL64:
      *reloc_addr = elf_machine_tprel (map, sym_map, sym, reloc);
      return;

    case R_PPC64_TPREL16_LO_DS:
      value = elf_machine_tprel (map, sym_map, sym, reloc);
      if (dont_expect ((value & 3) != 0))
	_dl_reloc_overflow (map, "R_PPC64_TPREL16_LO_DS", reloc_addr, refsym);
      BIT_INSERT (*(Elf64_Half *) reloc_addr, value, 0xfffc);
      break;

    case R_PPC64_TPREL16_DS:
      value = elf_machine_tprel (map, sym_map, sym, reloc);
      if (dont_expect ((value + 0x8000) >= 0x10000 || (value & 3) != 0))
	_dl_reloc_overflow (map, "R_PPC64_TPREL16_DS", reloc_addr, refsym);
      BIT_INSERT (*(Elf64_Half *) reloc_addr, value, 0xfffc);
      break;

    case R_PPC64_TPREL16:
      value = elf_machine_tprel (map, sym_map, sym, reloc);
      if (dont_expect ((value + 0x8000) >= 0x10000))
	_dl_reloc_overflow (map, "R_PPC64_TPREL16", reloc_addr, refsym);
      *(Elf64_Half *) reloc_addr = PPC_LO (value);
      break;

    case R_PPC64_TPREL16_LO:
      value = elf_machine_tprel (map, sym_map, sym, reloc);
      *(Elf64_Half *) reloc_addr = PPC_LO (value);
      break;

    case R_PPC64_TPREL16_HI:
      value = elf_machine_tprel (map, sym_map, sym, reloc);
      if (dont_expect (value + 0x80000000 >= 0x100000000LL))
	_dl_reloc_overflow (map, "R_PPC64_TPREL16_HI", reloc_addr, refsym);
      *(Elf64_Half *) reloc_addr = PPC_HI (value);
      break;

    case R_PPC64_TPREL16_HIGH:
      value = elf_machine_tprel (map, sym_map, sym, reloc);
      *(Elf64_Half *) reloc_addr = PPC_HI (value);
      break;

    case R_PPC64_TPREL16_HA:
      value = elf_machine_tprel (map, sym_map, sym, reloc);
      if (dont_expect (value + 0x80008000 >= 0x100000000LL))
	_dl_reloc_overflow (map, "R_PPC64_TPREL16_HA", reloc_addr, refsym);
      *(Elf64_Half *) reloc_addr = PPC_HA (value);
      break;

    case R_PPC64_TPREL16_HIGHA:
      value = elf_machine_tprel (map, sym_map, sym, reloc);
      *(Elf64_Half *) reloc_addr = PPC_HA (value);
      break;

    case R_PPC64_TPREL16_HIGHER:
      value = elf_machine_tprel (map, sym_map, sym, reloc);
      *(Elf64_Half *) reloc_addr = PPC_HIGHER (value);
      break;

    case R_PPC64_TPREL16_HIGHEST:
      value = elf_machine_tprel (map, sym_map, sym, reloc);
      *(Elf64_Half *) reloc_addr = PPC_HIGHEST (value);
      break;

    case R_PPC64_TPREL16_HIGHERA:
      value = elf_machine_tprel (map, sym_map, sym, reloc);
      *(Elf64_Half *) reloc_addr = PPC_HIGHERA (value);
      break;

    case R_PPC64_TPREL16_HIGHESTA:
      value = elf_machine_tprel (map, sym_map, sym, reloc);
      *(Elf64_Half *) reloc_addr = PPC_HIGHESTA (value);
      break;

#ifndef RTLD_BOOTSTRAP /* None of the following appear in ld.so */
    case R_PPC64_ADDR16_LO_DS:
      if (dont_expect ((value & 3) != 0))
	_dl_reloc_overflow (map, "R_PPC64_ADDR16_LO_DS", reloc_addr, refsym);
      BIT_INSERT (*(Elf64_Half *) reloc_addr, value, 0xfffc);
      break;

    case R_PPC64_ADDR16_LO:
      *(Elf64_Half *) reloc_addr = PPC_LO (value);
      break;

    case R_PPC64_ADDR16_HI:
      if (dont_expect (value + 0x80000000 >= 0x100000000LL))
	_dl_reloc_overflow (map, "R_PPC64_ADDR16_HI", reloc_addr, refsym);
      /* Fall through.  */
    case R_PPC64_ADDR16_HIGH:
      *(Elf64_Half *) reloc_addr = PPC_HI (value);
      break;

    case R_PPC64_ADDR16_HA:
      if (dont_expect (value + 0x80008000 >= 0x100000000LL))
	_dl_reloc_overflow (map, "R_PPC64_ADDR16_HA", reloc_addr, refsym);
      /* Fall through.  */
    case R_PPC64_ADDR16_HIGHA:
      *(Elf64_Half *) reloc_addr = PPC_HA (value);
      break;

    case R_PPC64_ADDR30:
      {
	Elf64_Addr delta = value - (Elf64_Xword) reloc_addr;
	if (dont_expect ((delta + 0x80000000) >= 0x100000000LL
			 || (delta & 3) != 0))
	  _dl_reloc_overflow (map, "R_PPC64_ADDR30", reloc_addr, refsym);
	BIT_INSERT (*(Elf64_Word *) reloc_addr, delta, 0xfffffffc);
      }
      break;

    case R_PPC64_COPY:
      if (dont_expect (sym == NULL))
	/* This can happen in trace mode when an object could not be found. */
	return;
      if (dont_expect (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, strtab + refsym->st_name);
	}
      memcpy (reloc_addr_arg, (char *) value,
	      MIN (sym->st_size, refsym->st_size));
      return;

    case R_PPC64_UADDR64:
      ((union unaligned *) reloc_addr)->u8 = value;
      return;

    case R_PPC64_UADDR32:
      ((union unaligned *) reloc_addr)->u4 = value;
      return;

    case R_PPC64_ADDR32:
      if (dont_expect ((value + 0x80000000) >= 0x100000000LL))
	_dl_reloc_overflow (map, "R_PPC64_ADDR32", reloc_addr, refsym);
      *(Elf64_Word *) reloc_addr = value;
      return;

    case R_PPC64_ADDR24:
      if (dont_expect ((value + 0x2000000) >= 0x4000000 || (value & 3) != 0))
	_dl_reloc_overflow (map, "R_PPC64_ADDR24", reloc_addr, refsym);
      BIT_INSERT (*(Elf64_Word *) reloc_addr, value, 0x3fffffc);
      break;

    case R_PPC64_ADDR16:
      if (dont_expect ((value + 0x8000) >= 0x10000))
	_dl_reloc_overflow (map, "R_PPC64_ADDR16", reloc_addr, refsym);
      *(Elf64_Half *) reloc_addr = value;
      break;

    case R_PPC64_UADDR16:
      if (dont_expect ((value + 0x8000) >= 0x10000))
	_dl_reloc_overflow (map, "R_PPC64_UADDR16", reloc_addr, refsym);
      ((union unaligned *) reloc_addr)->u2 = value;
      return;

    case R_PPC64_ADDR16_DS:
      if (dont_expect ((value + 0x8000) >= 0x10000 || (value & 3) != 0))
	_dl_reloc_overflow (map, "R_PPC64_ADDR16_DS", reloc_addr, refsym);
      BIT_INSERT (*(Elf64_Half *) reloc_addr, value, 0xfffc);
      break;

    case R_PPC64_ADDR16_HIGHER:
      *(Elf64_Half *) reloc_addr = PPC_HIGHER (value);
      break;

    case R_PPC64_ADDR16_HIGHEST:
      *(Elf64_Half *) reloc_addr = PPC_HIGHEST (value);
      break;

    case R_PPC64_ADDR16_HIGHERA:
      *(Elf64_Half *) reloc_addr = PPC_HIGHERA (value);
      break;

    case R_PPC64_ADDR16_HIGHESTA:
      *(Elf64_Half *) reloc_addr = PPC_HIGHESTA (value);
      break;

    case R_PPC64_ADDR14:
    case R_PPC64_ADDR14_BRTAKEN:
    case R_PPC64_ADDR14_BRNTAKEN:
      {
	if (dont_expect ((value + 0x8000) >= 0x10000 || (value & 3) != 0))
	  _dl_reloc_overflow (map, "R_PPC64_ADDR14", reloc_addr, refsym);
	Elf64_Word insn = *(Elf64_Word *) reloc_addr;
	BIT_INSERT (insn, value, 0xfffc);
	if (r_type != R_PPC64_ADDR14)
	  {
	    insn &= ~(1 << 21);
	    if (r_type == R_PPC64_ADDR14_BRTAKEN)
	      insn |= 1 << 21;
	    if ((insn & (0x14 << 21)) == (0x04 << 21))
	      insn |= 0x02 << 21;
	    else if ((insn & (0x14 << 21)) == (0x10 << 21))
	      insn |= 0x08 << 21;
	  }
	*(Elf64_Word *) reloc_addr = insn;
      }
      break;

    case R_PPC64_REL32:
      *(Elf64_Word *) reloc_addr = value - (Elf64_Addr) reloc_addr;
      return;

    case R_PPC64_REL64:
      *reloc_addr = value - (Elf64_Addr) reloc_addr;
      return;
#endif /* !RTLD_BOOTSTRAP */

    default:
      _dl_reloc_bad_type (map, r_type, 0);
      return;
    }
  MODIFIED_CODE_NOQUEUE (reloc_addr);
}

static inline void __attribute__ ((always_inline))
elf_machine_lazy_rel (struct link_map *map, struct r_scope_elem *scope[],
		      Elf64_Addr l_addr, const Elf64_Rela *reloc,
		      int skip_ifunc)
{
  /* elf_machine_runtime_setup handles this.  */
}


#endif /* RESOLVE */