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291 lines
9.0 KiB
C
291 lines
9.0 KiB
C
/* Machine-dependent ELF dynamic relocation inline functions. m68k version.
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Copyright (C) 1996-2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, write to the Free
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Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
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02111-1307 USA. */
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#ifndef dl_machine_h
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#define dl_machine_h
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#define ELF_MACHINE_NAME "m68k"
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#include <sys/param.h>
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/* Return nonzero iff ELF header is compatible with the running host. */
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static inline int
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elf_machine_matches_host (const Elf32_Ehdr *ehdr)
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{
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return ehdr->e_machine == EM_68K;
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}
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/* Return the link-time address of _DYNAMIC. Conveniently, this is the
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first element of the GOT. This must be inlined in a function which
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uses global data. */
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static inline Elf32_Addr
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elf_machine_dynamic (void)
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{
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register Elf32_Addr *got asm ("%a5");
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return *got;
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}
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/* Return the run-time load address of the shared object. */
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static inline Elf32_Addr
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elf_machine_load_address (void)
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{
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Elf32_Addr addr;
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asm ("lea _dl_start(%%pc), %0\n\t"
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"sub.l _dl_start@GOT.w(%%a5), %0"
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: "=a" (addr));
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return addr;
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}
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/* Set up the loaded object described by L so its unrelocated PLT
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entries will jump to the on-demand fixup code in dl-runtime.c. */
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static inline int __attribute__ ((always_inline))
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elf_machine_runtime_setup (struct link_map *l, int lazy, int profile)
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{
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Elf32_Addr *got;
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extern void _dl_runtime_resolve (Elf32_Word);
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extern void _dl_runtime_profile (Elf32_Word);
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if (l->l_info[DT_JMPREL] && lazy)
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{
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/* The GOT entries for functions in the PLT have not yet been
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filled in. Their initial contents will arrange when called
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to push an offset into the .rela.plt section, push
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_GLOBAL_OFFSET_TABLE_[1], and then jump to
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_GLOBAL_OFFSET_TABLE_[2]. */
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got = (Elf32_Addr *) D_PTR (l, l_info[DT_PLTGOT]);
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got[1] = (Elf32_Addr) l; /* Identify this shared object. */
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/* The got[2] entry contains the address of a function which gets
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called to get the address of a so far unresolved function and
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jump to it. The profiling extension of the dynamic linker allows
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to intercept the calls to collect information. In this case we
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don't store the address in the GOT so that all future calls also
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end in this function. */
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if (profile)
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{
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got[2] = (Elf32_Addr) &_dl_runtime_profile;
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if (GLRO(dl_profile) != NULL
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&& _dl_name_match_p (GLRO(dl_profile), l))
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{
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/* This is the object we are looking for. Say that we really
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want profiling and the timers are started. */
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GL(dl_profile_map) = l;
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}
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}
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else
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/* This function will get called to fix up the GOT entry indicated by
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the offset on the stack, and then jump to the resolved address. */
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got[2] = (Elf32_Addr) &_dl_runtime_resolve;
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}
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return lazy;
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}
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#define ELF_MACHINE_RUNTIME_FIXUP_ARGS long int save_a0, long int save_a1
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/* Mask identifying addresses reserved for the user program,
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where the dynamic linker should not map anything. */
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#define ELF_MACHINE_USER_ADDRESS_MASK 0x80000000UL
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/* Initial entry point code for the dynamic linker.
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The C function `_dl_start' is the real entry point;
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its return value is the user program's entry point. */
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#define RTLD_START asm ("\
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.text\n\
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.globl _start\n\
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.type _start,@function\n\
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_start:\n\
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move.l %sp, -(%sp)\n\
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jbsr _dl_start\n\
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addq.l #4, %sp\n\
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/* FALLTHRU */\n\
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\n\
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.globl _dl_start_user\n\
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.type _dl_start_user,@function\n\
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_dl_start_user:\n\
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| Save the user entry point address in %a4.\n\
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move.l %d0, %a4\n\
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| See if we were run as a command with the executable file\n\
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| name as an extra leading argument.\n\
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move.l _dl_skip_args(%pc), %d0\n\
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| Pop the original argument count\n\
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move.l (%sp)+, %d1\n\
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| Subtract _dl_skip_args from it.\n\
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sub.l %d0, %d1\n\
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| Adjust the stack pointer to skip _dl_skip_args words.\n\
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lea (%sp, %d0*4), %sp\n\
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| Push back the modified argument count.\n\
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move.l %d1, -(%sp)\n\
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# Call _dl_init (struct link_map *main_map, int argc, char **argv, char **env)\n\
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pea 8(%sp, %d1*4)\n\
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pea 8(%sp)\n\
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move.l %d1, -(%sp)\n\
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move.l _rtld_local(%pc), -(%sp)\n\
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jbsr _dl_init_internal@PLTPC\n\
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addq.l #8, %sp\n\
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addq.l #8, %sp\n\
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| Pass our finalizer function to the user in %a1.\n\
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lea _dl_fini(%pc), %a1\n\
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| Initialize %fp with the stack pointer.\n\
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move.l %sp, %fp\n\
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| Jump to the user's entry point.\n\
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jmp (%a4)\n\
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.size _dl_start_user, . - _dl_start_user\n\
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.previous");
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/* ELF_RTYPE_CLASS_PLT iff TYPE describes relocation of a PLT entry, so
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PLT entries should not be allowed to define the value.
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ELF_RTYPE_CLASS_NOCOPY iff TYPE should not be allowed to resolve to one
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of the main executable's symbols, as for a COPY reloc. */
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#define elf_machine_type_class(type) \
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((((type) == R_68K_JMP_SLOT) * ELF_RTYPE_CLASS_PLT) \
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| (((type) == R_68K_COPY) * ELF_RTYPE_CLASS_COPY))
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/* A reloc type used for ld.so cmdline arg lookups to reject PLT entries. */
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#define ELF_MACHINE_JMP_SLOT R_68K_JMP_SLOT
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/* The m68k never uses Elf32_Rel relocations. */
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#define ELF_MACHINE_NO_REL 1
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static inline Elf32_Addr
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elf_machine_fixup_plt (struct link_map *map, lookup_t t,
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const Elf32_Rela *reloc,
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Elf32_Addr *reloc_addr, Elf32_Addr value)
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{
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return *reloc_addr = value;
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}
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/* Return the final value of a plt relocation. On the m68k the JMP_SLOT
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relocation ignores the addend. */
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static inline Elf32_Addr
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elf_machine_plt_value (struct link_map *map, const Elf32_Rela *reloc,
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Elf32_Addr value)
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{
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return value;
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}
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/* Names of the architecture-specific auditing callback functions. */
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#define ARCH_LA_PLTENTER m68k_gnu_pltenter
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#define ARCH_LA_PLTEXIT m68k_gnu_pltexit
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#endif /* !dl_machine_h */
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#ifdef RESOLVE_MAP
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/* Perform the relocation specified by RELOC and SYM (which is fully resolved).
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MAP is the object containing the reloc. */
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auto inline void __attribute__ ((unused, always_inline))
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elf_machine_rela (struct link_map *map, const Elf32_Rela *reloc,
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const Elf32_Sym *sym, const struct r_found_version *version,
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void *const reloc_addr_arg)
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{
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Elf32_Addr *const reloc_addr = reloc_addr_arg;
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const unsigned int r_type = ELF32_R_TYPE (reloc->r_info);
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if (__builtin_expect (r_type == R_68K_RELATIVE, 0))
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*reloc_addr = map->l_addr + reloc->r_addend;
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else
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{
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const Elf32_Sym *const refsym = sym;
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struct link_map *sym_map = RESOLVE_MAP (&sym, version, r_type);
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Elf32_Addr value = sym == NULL ? 0 : sym_map->l_addr + sym->st_value;
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switch (r_type)
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{
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case R_68K_COPY:
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if (sym == NULL)
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/* This can happen in trace mode if an object could not be
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found. */
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break;
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if (sym->st_size > refsym->st_size
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|| (sym->st_size < refsym->st_size && GLRO(dl_verbose)))
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{
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const char *strtab;
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strtab = (const void *) D_PTR (map, l_info[DT_STRTAB]);
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_dl_error_printf ("\
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%s: Symbol `%s' has different size in shared object, consider re-linking\n",
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rtld_progname ?: "<program name unknown>",
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strtab + refsym->st_name);
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}
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memcpy (reloc_addr_arg, (void *) value,
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MIN (sym->st_size, refsym->st_size));
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break;
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case R_68K_GLOB_DAT:
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case R_68K_JMP_SLOT:
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*reloc_addr = value;
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break;
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case R_68K_8:
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*(char *) reloc_addr = value + reloc->r_addend;
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break;
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case R_68K_16:
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*(short *) reloc_addr = value + reloc->r_addend;
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break;
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case R_68K_32:
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*reloc_addr = value + reloc->r_addend;
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break;
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case R_68K_PC8:
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*(char *) reloc_addr
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= value + reloc->r_addend - (Elf32_Addr) reloc_addr;
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break;
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case R_68K_PC16:
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*(short *) reloc_addr
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= value + reloc->r_addend - (Elf32_Addr) reloc_addr;
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break;
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case R_68K_PC32:
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*reloc_addr = value + reloc->r_addend - (Elf32_Addr) reloc_addr;
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break;
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case R_68K_NONE: /* Alright, Wilbur. */
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break;
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default:
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_dl_reloc_bad_type (map, r_type, 0);
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break;
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}
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}
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}
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auto inline void __attribute__ ((unused, always_inline))
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elf_machine_rela_relative (Elf32_Addr l_addr, const Elf32_Rela *reloc,
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void *const reloc_addr_arg)
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{
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Elf32_Addr *const reloc_addr = reloc_addr_arg;
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*reloc_addr = l_addr + reloc->r_addend;
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}
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auto inline void __attribute__ ((unused, always_inline))
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elf_machine_lazy_rel (struct link_map *map,
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Elf32_Addr l_addr, const Elf32_Rela *reloc)
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{
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Elf32_Addr *const reloc_addr = (void *) (l_addr + reloc->r_offset);
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if (ELF32_R_TYPE (reloc->r_info) == R_68K_JMP_SLOT)
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*reloc_addr += l_addr;
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else
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_dl_reloc_bad_type (map, ELF32_R_TYPE (reloc->r_info), 1);
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}
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#endif /* RESOLVE_MAP */
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