938 lines
28 KiB
C
938 lines
28 KiB
C
/* Machine-dependent ELF dynamic relocation inline functions. MIPS version.
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Copyright (C) 1996-2017 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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Contributed by Kazumoto Kojima <kkojima@info.kanagawa-u.ac.jp>.
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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, see
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<http://www.gnu.org/licenses/>. */
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/* FIXME: Profiling of shared libraries is not implemented yet. */
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#ifndef dl_machine_h
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#define dl_machine_h
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#define ELF_MACHINE_NAME "MIPS"
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#include <entry.h>
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#ifndef ENTRY_POINT
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#error ENTRY_POINT needs to be defined for MIPS.
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#endif
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#include <sgidefs.h>
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#include <sysdep.h>
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#include <sys/asm.h>
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#include <dl-tls.h>
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/* The offset of gp from GOT might be system-dependent. It's set by
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ld. The same value is also */
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#define OFFSET_GP_GOT 0x7ff0
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#ifndef _RTLD_PROLOGUE
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# define _RTLD_PROLOGUE(entry) \
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".globl\t" __STRING(entry) "\n\t" \
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".ent\t" __STRING(entry) "\n\t" \
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".type\t" __STRING(entry) ", @function\n" \
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__STRING(entry) ":\n\t"
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#endif
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#ifndef _RTLD_EPILOGUE
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# define _RTLD_EPILOGUE(entry) \
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".end\t" __STRING(entry) "\n\t" \
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".size\t" __STRING(entry) ", . - " __STRING(entry) "\n\t"
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#endif
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/* A reloc type used for ld.so cmdline arg lookups to reject PLT entries.
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This only makes sense on MIPS when using PLTs, so choose the
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PLT relocation (not encountered when not using PLTs). */
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#define ELF_MACHINE_JMP_SLOT R_MIPS_JUMP_SLOT
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#define elf_machine_type_class(type) \
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((((type) == ELF_MACHINE_JMP_SLOT) * ELF_RTYPE_CLASS_PLT) \
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| (((type) == R_MIPS_COPY) * ELF_RTYPE_CLASS_COPY))
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#define ELF_MACHINE_PLT_REL 1
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#define ELF_MACHINE_NO_REL 0
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#define ELF_MACHINE_NO_RELA 0
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/* Translate a processor specific dynamic tag to the index
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in l_info array. */
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#define DT_MIPS(x) (DT_MIPS_##x - DT_LOPROC + DT_NUM)
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/* If there is a DT_MIPS_RLD_MAP_REL or DT_MIPS_RLD_MAP entry in the dynamic
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section, fill in the debug map pointer with the run-time address of the
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r_debug structure. */
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#define ELF_MACHINE_DEBUG_SETUP(l,r) \
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do { if ((l)->l_info[DT_MIPS (RLD_MAP_REL)]) \
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{ \
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char *ptr = (char *)(l)->l_info[DT_MIPS (RLD_MAP_REL)]; \
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ptr += (l)->l_info[DT_MIPS (RLD_MAP_REL)]->d_un.d_val; \
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*(ElfW(Addr) *)ptr = (ElfW(Addr)) (r); \
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} \
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else if ((l)->l_info[DT_MIPS (RLD_MAP)]) \
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*(ElfW(Addr) *)((l)->l_info[DT_MIPS (RLD_MAP)]->d_un.d_ptr) = \
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(ElfW(Addr)) (r); \
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} while (0)
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#if ((defined __mips_nan2008 && !defined HAVE_MIPS_NAN2008) \
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|| (!defined __mips_nan2008 && defined HAVE_MIPS_NAN2008))
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# error "Configuration inconsistency: __mips_nan2008 != HAVE_MIPS_NAN2008, overridden CFLAGS?"
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#endif
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#ifdef __mips_nan2008
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# define ELF_MACHINE_NAN2008 EF_MIPS_NAN2008
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#else
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# define ELF_MACHINE_NAN2008 0
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#endif
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/* Return nonzero iff ELF header is compatible with the running host. */
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static inline int __attribute_used__
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elf_machine_matches_host (const ElfW(Ehdr) *ehdr)
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{
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#if _MIPS_SIM == _ABIO32 || _MIPS_SIM == _ABIN32
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/* Don't link o32 and n32 together. */
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if (((ehdr->e_flags & EF_MIPS_ABI2) != 0) != (_MIPS_SIM == _ABIN32))
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return 0;
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#endif
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/* Don't link 2008-NaN and legacy-NaN objects together. */
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if ((ehdr->e_flags & EF_MIPS_NAN2008) != ELF_MACHINE_NAN2008)
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return 0;
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/* Ensure that the old O32 FP64 ABI is never loaded, it is not supported
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on linux. */
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if (ehdr->e_flags & EF_MIPS_FP64)
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return 0;
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switch (ehdr->e_machine)
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{
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case EM_MIPS:
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case EM_MIPS_RS3_LE:
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return 1;
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default:
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return 0;
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}
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}
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static inline ElfW(Addr) *
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elf_mips_got_from_gpreg (ElfW(Addr) gpreg)
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{
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/* FIXME: the offset of gp from GOT may be system-dependent. */
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return (ElfW(Addr) *) (gpreg - OFFSET_GP_GOT);
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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. We assume its $gp points to the primary GOT. */
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static inline ElfW(Addr)
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elf_machine_dynamic (void)
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{
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register ElfW(Addr) gp __asm__ ("$28");
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return *elf_mips_got_from_gpreg (gp);
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}
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#define STRINGXP(X) __STRING(X)
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#define STRINGXV(X) STRINGV_(X)
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#define STRINGV_(...) # __VA_ARGS__
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/* Return the run-time load address of the shared object. */
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static inline ElfW(Addr)
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elf_machine_load_address (void)
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{
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ElfW(Addr) addr;
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#ifndef __mips16
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asm (" .set noreorder\n"
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" " STRINGXP (PTR_LA) " %0, 0f\n"
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# if !defined __mips_isa_rev || __mips_isa_rev < 6
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" bltzal $0, 0f\n"
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" nop\n"
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"0: " STRINGXP (PTR_SUBU) " %0, $31, %0\n"
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# else
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"0: addiupc $31, 0\n"
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" " STRINGXP (PTR_SUBU) " %0, $31, %0\n"
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# endif
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" .set reorder\n"
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: "=r" (addr)
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: /* No inputs */
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: "$31");
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#else
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ElfW(Addr) tmp;
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asm (" .set noreorder\n"
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" move %1,$gp\n"
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" lw %1,%%got(0f)(%1)\n"
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"0: .fill 0\n" /* Clear the ISA bit on 0:. */
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" la %0,0b\n"
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" addiu %1,%%lo(0b)\n"
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" subu %0,%1\n"
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" .set reorder\n"
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: "=d" (addr), "=d" (tmp)
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: /* No inputs */);
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#endif
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return addr;
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}
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/* The MSB of got[1] of a gnu object is set to identify gnu objects. */
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#if _MIPS_SIM == _ABI64
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# define ELF_MIPS_GNU_GOT1_MASK 0x8000000000000000L
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#else
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# define ELF_MIPS_GNU_GOT1_MASK 0x80000000L
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#endif
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/* We can't rely on elf_machine_got_rel because _dl_object_relocation_scope
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fiddles with global data. */
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#define ELF_MACHINE_BEFORE_RTLD_RELOC(dynamic_info) \
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do { \
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struct link_map *map = &bootstrap_map; \
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ElfW(Sym) *sym; \
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ElfW(Addr) *got; \
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int i, n; \
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\
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got = (ElfW(Addr) *) D_PTR (map, l_info[DT_PLTGOT]); \
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\
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if (__builtin_expect (map->l_addr == 0, 1)) \
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break; \
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\
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/* got[0] is reserved. got[1] is also reserved for the dynamic object \
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generated by gnu ld. Skip these reserved entries from \
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relocation. */ \
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i = (got[1] & ELF_MIPS_GNU_GOT1_MASK)? 2 : 1; \
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n = map->l_info[DT_MIPS (LOCAL_GOTNO)]->d_un.d_val; \
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\
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/* Add the run-time displacement to all local got entries. */ \
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while (i < n) \
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got[i++] += map->l_addr; \
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\
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/* Handle global got entries. */ \
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got += n; \
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sym = (ElfW(Sym) *) D_PTR(map, l_info[DT_SYMTAB]) \
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+ map->l_info[DT_MIPS (GOTSYM)]->d_un.d_val; \
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i = (map->l_info[DT_MIPS (SYMTABNO)]->d_un.d_val \
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- map->l_info[DT_MIPS (GOTSYM)]->d_un.d_val); \
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\
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while (i--) \
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{ \
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if (sym->st_shndx == SHN_UNDEF || sym->st_shndx == SHN_COMMON) \
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*got = map->l_addr + sym->st_value; \
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else if (ELFW(ST_TYPE) (sym->st_info) == STT_FUNC \
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&& *got != sym->st_value) \
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*got += map->l_addr; \
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else if (ELFW(ST_TYPE) (sym->st_info) == STT_SECTION) \
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{ \
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if (sym->st_other == 0) \
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*got += map->l_addr; \
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} \
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else \
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*got = map->l_addr + sym->st_value; \
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\
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got++; \
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sym++; \
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} \
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} while(0)
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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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Note how we have to be careful about two things:
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1) That we allocate a minimal stack of 24 bytes for
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every function call, the MIPS ABI states that even
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if all arguments are passed in registers the procedure
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called can use the 16 byte area pointed to by $sp
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when it is called to store away the arguments passed
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to it.
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2) That under Unix the entry is named __start
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and not just plain _start. */
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#ifndef __mips16
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# if !defined __mips_isa_rev || __mips_isa_rev < 6
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# define LCOFF STRINGXP(.Lcof2)
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# define LOAD_31 STRINGXP(bltzal $8) "," STRINGXP(.Lcof2)
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# else
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# define LCOFF STRINGXP(.Lcof1)
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# define LOAD_31 "addiupc $31, 0"
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# endif
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# define RTLD_START asm (\
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".text\n\
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" _RTLD_PROLOGUE(ENTRY_POINT) "\
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" STRINGXV(SETUP_GPX($25)) "\n\
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" STRINGXV(SETUP_GPX64($18,$25)) "\n\
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# i386 ABI book says that the first entry of GOT holds\n\
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# the address of the dynamic structure. Though MIPS ABI\n\
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# doesn't say nothing about this, I emulate this here.\n\
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" STRINGXP(PTR_LA) " $4, _DYNAMIC\n\
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# Subtract OFFSET_GP_GOT\n\
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" STRINGXP(PTR_S) " $4, -0x7ff0($28)\n\
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move $4, $29\n\
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" STRINGXP(PTR_SUBIU) " $29, 16\n\
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\n\
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" STRINGXP(PTR_LA) " $8, " LCOFF "\n\
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.Lcof1: " LOAD_31 "\n\
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.Lcof2: " STRINGXP(PTR_SUBU) " $8, $31, $8\n\
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\n\
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" STRINGXP(PTR_LA) " $25, _dl_start\n\
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" STRINGXP(PTR_ADDU) " $25, $8\n\
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jalr $25\n\
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\n\
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" STRINGXP(PTR_ADDIU) " $29, 16\n\
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# Get the value of label '_dl_start_user' in t9 ($25).\n\
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" STRINGXP(PTR_LA) " $25, _dl_start_user\n\
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" _RTLD_EPILOGUE(ENTRY_POINT) "\
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\n\
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\n\
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" _RTLD_PROLOGUE(_dl_start_user) "\
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" STRINGXP(SETUP_GP) "\n\
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" STRINGXV(SETUP_GP64($18,_dl_start_user)) "\n\
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move $16, $28\n\
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# Save the user entry point address in a saved register.\n\
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move $17, $2\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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lw $2, _dl_skip_args\n\
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beq $2, $0, 1f\n\
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# Load the original argument count.\n\
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" STRINGXP(PTR_L) " $4, 0($29)\n\
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# Subtract _dl_skip_args from it.\n\
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subu $4, $2\n\
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# Adjust the stack pointer to skip _dl_skip_args words.\n\
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sll $2, " STRINGXP (PTRLOG) "\n\
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" STRINGXP(PTR_ADDU) " $29, $2\n\
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# Save back the modified argument count.\n\
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" STRINGXP(PTR_S) " $4, 0($29)\n\
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1: # Call _dl_init (struct link_map *main_map, int argc, char **argv, char **env) \n\
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" STRINGXP(PTR_L) " $4, _rtld_local\n\
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" STRINGXP(PTR_L) /* or lw??? fixme */ " $5, 0($29)\n\
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" STRINGXP(PTR_LA) " $6, " STRINGXP (PTRSIZE) "($29)\n\
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sll $7, $5, " STRINGXP (PTRLOG) "\n\
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" STRINGXP(PTR_ADDU) " $7, $7, $6\n\
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" STRINGXP(PTR_ADDU) " $7, $7, " STRINGXP (PTRSIZE) " \n\
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# Make sure the stack pointer is aligned for _dl_init.\n\
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and $2, $29, -2 * " STRINGXP(SZREG) "\n\
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move $8, $29\n\
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" STRINGXP(PTR_SUBIU) " $29, $2, 32\n\
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" STRINGXP(PTR_S) " $8, (32 - " STRINGXP(SZREG) ")($29)\n\
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" STRINGXP(SAVE_GP(16)) "\n\
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# Call the function to run the initializers.\n\
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jal _dl_init\n\
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# Restore the stack pointer for _start.\n\
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" STRINGXP(PTR_L) " $29, (32 - " STRINGXP(SZREG) ")($29)\n\
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# Pass our finalizer function to the user in $2 as per ELF ABI.\n\
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" STRINGXP(PTR_LA) " $2, _dl_fini\n\
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# Jump to the user entry point.\n\
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move $25, $17\n\
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jr $25\n\t"\
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_RTLD_EPILOGUE(_dl_start_user)\
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".previous"\
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);
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#else /* __mips16 */
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/* MIPS16 version. We currently only support O32 under MIPS16; the proper
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assembly preprocessor abstractions will need to be added if other ABIs
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are to be supported. */
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# define RTLD_START asm (\
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".text\n\
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.set mips16\n\
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" _RTLD_PROLOGUE (ENTRY_POINT) "\
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# Construct GP value in $3.\n\
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li $3, %hi(_gp_disp)\n\
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addiu $4, $pc, %lo(_gp_disp)\n\
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sll $3, 16\n\
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addu $3, $4\n\
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move $28, $3\n\
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lw $4, %got(_DYNAMIC)($3)\n\
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sw $4, -0x7ff0($3)\n\
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move $4, $sp\n\
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addiu $sp, -16\n\
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# _dl_start() is sufficiently near to use pc-relative\n\
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# load address.\n\
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la $3, _dl_start\n\
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move $25, $3\n\
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jalr $3\n\
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addiu $sp, 16\n\
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" _RTLD_EPILOGUE (ENTRY_POINT) "\
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\n\
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\n\
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" _RTLD_PROLOGUE (_dl_start_user) "\
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li $16, %hi(_gp_disp)\n\
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addiu $4, $pc, %lo(_gp_disp)\n\
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sll $16, 16\n\
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addu $16, $4\n\
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move $17, $2\n\
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move $28, $16\n\
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lw $4, %got(_dl_skip_args)($16)\n\
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lw $4, 0($4)\n\
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beqz $4, 1f\n\
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# Load the original argument count.\n\
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lw $5, 0($sp)\n\
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# Subtract _dl_skip_args from it.\n\
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subu $5, $4\n\
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# Adjust the stack pointer to skip _dl_skip_args words.\n\
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sll $4, " STRINGXP (PTRLOG) "\n\
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move $6, $sp\n\
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addu $6, $4\n\
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move $sp, $6\n\
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# Save back the modified argument count.\n\
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|
sw $5, 0($sp)\n\
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|
1: # Call _dl_init (struct link_map *main_map, int argc, char **argv, char **env) \n\
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lw $4, %got(_rtld_local)($16)\n\
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lw $4, 0($4)\n\
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lw $5, 0($sp)\n\
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addiu $6, $sp, " STRINGXP (PTRSIZE) "\n\
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sll $7, $5, " STRINGXP (PTRLOG) "\n\
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addu $7, $6\n\
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addu $7, " STRINGXP (PTRSIZE) "\n\
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# Make sure the stack pointer is aligned for _dl_init.\n\
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li $2, 2 * " STRINGXP (SZREG) "\n\
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neg $2, $2\n\
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move $3, $sp\n\
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and $2, $3\n\
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sw $3, -" STRINGXP (SZREG) "($2)\n\
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addiu $2, -32\n\
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move $sp, $2\n\
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sw $16, 16($sp)\n\
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# Call the function to run the initializers.\n\
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lw $2, %call16(_dl_init)($16)\n\
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move $25, $2\n\
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jalr $2\n\
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# Restore the stack pointer for _start.\n\
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lw $2, 32-" STRINGXP (SZREG) "($sp)\n\
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move $sp, $2\n\
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move $28, $16\n\
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# Pass our finalizer function to the user in $2 as per ELF ABI.\n\
|
|
lw $2, %call16(_dl_fini)($16)\n\
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|
# Jump to the user entry point.\n\
|
|
move $25, $17\n\
|
|
jr $17\n\t"\
|
|
_RTLD_EPILOGUE (_dl_start_user)\
|
|
".previous"\
|
|
);
|
|
|
|
#endif /* __mips16 */
|
|
|
|
/* Names of the architecture-specific auditing callback functions. */
|
|
# if _MIPS_SIM == _ABIO32
|
|
# define ARCH_LA_PLTENTER mips_o32_gnu_pltenter
|
|
# define ARCH_LA_PLTEXIT mips_o32_gnu_pltexit
|
|
# elif _MIPS_SIM == _ABIN32
|
|
# define ARCH_LA_PLTENTER mips_n32_gnu_pltenter
|
|
# define ARCH_LA_PLTEXIT mips_n32_gnu_pltexit
|
|
# else
|
|
# define ARCH_LA_PLTENTER mips_n64_gnu_pltenter
|
|
# define ARCH_LA_PLTEXIT mips_n64_gnu_pltexit
|
|
# endif
|
|
|
|
/* We define an initialization function. This is called very early in
|
|
_dl_sysdep_start. */
|
|
#define DL_PLATFORM_INIT dl_platform_init ()
|
|
|
|
static inline void __attribute__ ((unused))
|
|
dl_platform_init (void)
|
|
{
|
|
if (GLRO(dl_platform) != NULL && *GLRO(dl_platform) == '\0')
|
|
/* Avoid an empty string which would disturb us. */
|
|
GLRO(dl_platform) = NULL;
|
|
}
|
|
|
|
/* For a non-writable PLT, rewrite the .got.plt entry at RELOC_ADDR to
|
|
point at the symbol with address VALUE. For a writable PLT, rewrite
|
|
the corresponding PLT entry instead. */
|
|
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(Rel) *reloc,
|
|
ElfW(Addr) *reloc_addr, ElfW(Addr) value)
|
|
{
|
|
return *reloc_addr = value;
|
|
}
|
|
|
|
static inline ElfW(Addr)
|
|
elf_machine_plt_value (struct link_map *map, const ElfW(Rel) *reloc,
|
|
ElfW(Addr) value)
|
|
{
|
|
return value;
|
|
}
|
|
|
|
/* The semantics of zero/non-zero values of undefined symbols differs
|
|
depending on whether the non-PIC ABI is in use. Under the non-PIC
|
|
ABI, a non-zero value indicates that there is an address reference
|
|
to the symbol and thus it must always be resolved (except when
|
|
resolving a jump slot relocation) to the PLT entry whose address is
|
|
provided as the symbol's value; a zero value indicates that this
|
|
canonical-address behaviour is not required. Yet under the classic
|
|
MIPS psABI, a zero value indicates that there is an address
|
|
reference to the function and the dynamic linker must resolve the
|
|
symbol immediately upon loading. To avoid conflict, symbols for
|
|
which the dynamic linker must assume the non-PIC ABI semantics are
|
|
marked with the STO_MIPS_PLT flag. */
|
|
#define ELF_MACHINE_SYM_NO_MATCH(sym) \
|
|
((sym)->st_shndx == SHN_UNDEF && !((sym)->st_other & STO_MIPS_PLT))
|
|
|
|
#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_reloc (struct link_map *map, ElfW(Addr) r_info,
|
|
const ElfW(Sym) *sym, const struct r_found_version *version,
|
|
void *reloc_addr, ElfW(Addr) r_addend, int inplace_p)
|
|
{
|
|
const unsigned long int r_type = ELFW(R_TYPE) (r_info);
|
|
ElfW(Addr) *addr_field = (ElfW(Addr) *) reloc_addr;
|
|
|
|
#if !defined RTLD_BOOTSTRAP && !defined SHARED
|
|
/* 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 (GL(dl_rtld_map));
|
|
#endif
|
|
|
|
switch (r_type)
|
|
{
|
|
#if !defined (RTLD_BOOTSTRAP)
|
|
# if _MIPS_SIM == _ABI64
|
|
case R_MIPS_TLS_DTPMOD64:
|
|
case R_MIPS_TLS_DTPREL64:
|
|
case R_MIPS_TLS_TPREL64:
|
|
# else
|
|
case R_MIPS_TLS_DTPMOD32:
|
|
case R_MIPS_TLS_DTPREL32:
|
|
case R_MIPS_TLS_TPREL32:
|
|
# endif
|
|
{
|
|
struct link_map *sym_map = RESOLVE_MAP (&sym, version, r_type);
|
|
|
|
switch (r_type)
|
|
{
|
|
case R_MIPS_TLS_DTPMOD64:
|
|
case R_MIPS_TLS_DTPMOD32:
|
|
if (sym_map)
|
|
*addr_field = sym_map->l_tls_modid;
|
|
break;
|
|
|
|
case R_MIPS_TLS_DTPREL64:
|
|
case R_MIPS_TLS_DTPREL32:
|
|
if (sym)
|
|
{
|
|
if (inplace_p)
|
|
r_addend = *addr_field;
|
|
*addr_field = r_addend + TLS_DTPREL_VALUE (sym);
|
|
}
|
|
break;
|
|
|
|
case R_MIPS_TLS_TPREL32:
|
|
case R_MIPS_TLS_TPREL64:
|
|
if (sym)
|
|
{
|
|
CHECK_STATIC_TLS (map, sym_map);
|
|
if (inplace_p)
|
|
r_addend = *addr_field;
|
|
*addr_field = r_addend + TLS_TPREL_VALUE (sym_map, sym);
|
|
}
|
|
break;
|
|
}
|
|
|
|
break;
|
|
}
|
|
#endif
|
|
|
|
#if _MIPS_SIM == _ABI64
|
|
case (R_MIPS_64 << 8) | R_MIPS_REL32:
|
|
#else
|
|
case R_MIPS_REL32:
|
|
#endif
|
|
{
|
|
int symidx = ELFW(R_SYM) (r_info);
|
|
ElfW(Addr) reloc_value;
|
|
|
|
if (inplace_p)
|
|
/* Support relocations on mis-aligned offsets. */
|
|
__builtin_memcpy (&reloc_value, reloc_addr, sizeof (reloc_value));
|
|
else
|
|
reloc_value = r_addend;
|
|
|
|
if (symidx)
|
|
{
|
|
const ElfW(Word) gotsym
|
|
= (const ElfW(Word)) map->l_info[DT_MIPS (GOTSYM)]->d_un.d_val;
|
|
|
|
if ((ElfW(Word))symidx < gotsym)
|
|
{
|
|
/* This wouldn't work for a symbol imported from other
|
|
libraries for which there's no GOT entry, but MIPS
|
|
requires every symbol referenced in a dynamic
|
|
relocation to have a GOT entry in the primary GOT,
|
|
so we only get here for locally-defined symbols.
|
|
For section symbols, we should *NOT* be adding
|
|
sym->st_value (per the definition of the meaning of
|
|
S in reloc expressions in the ELF64 MIPS ABI),
|
|
since it should have already been added to
|
|
reloc_value by the linker, but older versions of
|
|
GNU ld didn't add it, and newer versions don't emit
|
|
useless relocations to section symbols any more, so
|
|
it is safe to keep on adding sym->st_value, even
|
|
though it's not ABI compliant. Some day we should
|
|
bite the bullet and stop doing this. */
|
|
#ifndef RTLD_BOOTSTRAP
|
|
if (map != &GL(dl_rtld_map))
|
|
#endif
|
|
reloc_value += sym->st_value + map->l_addr;
|
|
}
|
|
else
|
|
{
|
|
#ifndef RTLD_BOOTSTRAP
|
|
const ElfW(Addr) *got
|
|
= (const ElfW(Addr) *) D_PTR (map, l_info[DT_PLTGOT]);
|
|
const ElfW(Word) local_gotno
|
|
= (const ElfW(Word))
|
|
map->l_info[DT_MIPS (LOCAL_GOTNO)]->d_un.d_val;
|
|
|
|
reloc_value += got[symidx + local_gotno - gotsym];
|
|
#endif
|
|
}
|
|
}
|
|
else
|
|
#ifndef RTLD_BOOTSTRAP
|
|
if (map != &GL(dl_rtld_map))
|
|
#endif
|
|
reloc_value += map->l_addr;
|
|
|
|
__builtin_memcpy (reloc_addr, &reloc_value, sizeof (reloc_value));
|
|
}
|
|
break;
|
|
#ifndef RTLD_BOOTSTRAP
|
|
#if _MIPS_SIM == _ABI64
|
|
case (R_MIPS_64 << 8) | R_MIPS_GLOB_DAT:
|
|
#else
|
|
case R_MIPS_GLOB_DAT:
|
|
#endif
|
|
{
|
|
int symidx = ELFW(R_SYM) (r_info);
|
|
const ElfW(Word) gotsym
|
|
= (const ElfW(Word)) map->l_info[DT_MIPS (GOTSYM)]->d_un.d_val;
|
|
|
|
if (__builtin_expect ((ElfW(Word)) symidx >= gotsym, 1))
|
|
{
|
|
const ElfW(Addr) *got
|
|
= (const ElfW(Addr) *) D_PTR (map, l_info[DT_PLTGOT]);
|
|
const ElfW(Word) local_gotno
|
|
= ((const ElfW(Word))
|
|
map->l_info[DT_MIPS (LOCAL_GOTNO)]->d_un.d_val);
|
|
|
|
ElfW(Addr) reloc_value = got[symidx + local_gotno - gotsym];
|
|
__builtin_memcpy (reloc_addr, &reloc_value, sizeof (reloc_value));
|
|
}
|
|
}
|
|
break;
|
|
#endif
|
|
case R_MIPS_NONE: /* Alright, Wilbur. */
|
|
break;
|
|
|
|
case R_MIPS_JUMP_SLOT:
|
|
{
|
|
struct link_map *sym_map;
|
|
ElfW(Addr) value;
|
|
|
|
/* The addend for a jump slot relocation must always be zero:
|
|
calls via the PLT always branch to the symbol's address and
|
|
not to the address plus a non-zero offset. */
|
|
if (r_addend != 0)
|
|
_dl_signal_error (0, map->l_name, NULL,
|
|
"found jump slot relocation with non-zero addend");
|
|
|
|
sym_map = RESOLVE_MAP (&sym, version, r_type);
|
|
value = sym_map == NULL ? 0 : sym_map->l_addr + sym->st_value;
|
|
*addr_field = value;
|
|
|
|
break;
|
|
}
|
|
|
|
case R_MIPS_COPY:
|
|
{
|
|
const ElfW(Sym) *const refsym = sym;
|
|
struct link_map *sym_map;
|
|
ElfW(Addr) value;
|
|
|
|
/* Calculate the address of the symbol. */
|
|
sym_map = RESOLVE_MAP (&sym, version, r_type);
|
|
value = sym_map == NULL ? 0 : sym_map->l_addr + sym->st_value;
|
|
|
|
if (__builtin_expect (sym == NULL, 0))
|
|
/* This can happen in trace mode if an object could not be
|
|
found. */
|
|
break;
|
|
if (__builtin_expect (sym->st_size > refsym->st_size, 0)
|
|
|| (__builtin_expect (sym->st_size < refsym->st_size, 0)
|
|
&& GLRO(dl_verbose)))
|
|
{
|
|
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, (void *) value,
|
|
MIN (sym->st_size, refsym->st_size));
|
|
break;
|
|
}
|
|
|
|
#if _MIPS_SIM == _ABI64
|
|
case R_MIPS_64:
|
|
/* For full compliance with the ELF64 ABI, one must precede the
|
|
_REL32/_64 pair of relocations with a _64 relocation, such
|
|
that the in-place addend is read as a 64-bit value. IRIX
|
|
didn't pick up on this requirement, so we treat the
|
|
_REL32/_64 relocation as a 64-bit relocation even if it's by
|
|
itself. For ABI compliance, we ignore such _64 dummy
|
|
relocations. For RELA, this may be simply removed, since
|
|
it's totally unnecessary. */
|
|
if (ELFW(R_SYM) (r_info) == 0)
|
|
break;
|
|
/* Fall through. */
|
|
#endif
|
|
default:
|
|
_dl_reloc_bad_type (map, r_type, 0);
|
|
break;
|
|
}
|
|
}
|
|
|
|
/* Perform the relocation specified by RELOC and SYM (which is fully resolved).
|
|
MAP is the object containing the reloc. */
|
|
|
|
auto inline void
|
|
__attribute__ ((always_inline))
|
|
elf_machine_rel (struct link_map *map, const ElfW(Rel) *reloc,
|
|
const ElfW(Sym) *sym, const struct r_found_version *version,
|
|
void *const reloc_addr, int skip_ifunc)
|
|
{
|
|
elf_machine_reloc (map, reloc->r_info, sym, version, reloc_addr, 0, 1);
|
|
}
|
|
|
|
auto inline void
|
|
__attribute__((always_inline))
|
|
elf_machine_rel_relative (ElfW(Addr) l_addr, const ElfW(Rel) *reloc,
|
|
void *const reloc_addr)
|
|
{
|
|
/* XXX Nothing to do. There is no relative relocation, right? */
|
|
}
|
|
|
|
auto inline void
|
|
__attribute__((always_inline))
|
|
elf_machine_lazy_rel (struct link_map *map,
|
|
ElfW(Addr) l_addr, const ElfW(Rel) *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_MIPS_JUMP_SLOT, 1))
|
|
{
|
|
if (__builtin_expect (map->l_mach.plt, 0) == 0)
|
|
{
|
|
/* Nothing is required here since we only support lazy
|
|
relocation in executables. */
|
|
}
|
|
else
|
|
*reloc_addr = map->l_mach.plt;
|
|
}
|
|
else
|
|
_dl_reloc_bad_type (map, r_type, 1);
|
|
}
|
|
|
|
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)
|
|
{
|
|
elf_machine_reloc (map, reloc->r_info, sym, version, reloc_addr,
|
|
reloc->r_addend, 0);
|
|
}
|
|
|
|
auto inline void
|
|
__attribute__((always_inline))
|
|
elf_machine_rela_relative (ElfW(Addr) l_addr, const ElfW(Rela) *reloc,
|
|
void *const reloc_addr)
|
|
{
|
|
}
|
|
|
|
#ifndef RTLD_BOOTSTRAP
|
|
/* Relocate GOT. */
|
|
auto inline void
|
|
__attribute__((always_inline))
|
|
elf_machine_got_rel (struct link_map *map, int lazy)
|
|
{
|
|
ElfW(Addr) *got;
|
|
ElfW(Sym) *sym;
|
|
const ElfW(Half) *vernum;
|
|
int i, n, symidx;
|
|
|
|
#define RESOLVE_GOTSYM(sym,vernum,sym_index,reloc) \
|
|
({ \
|
|
const ElfW(Sym) *ref = sym; \
|
|
const struct r_found_version *version __attribute__ ((unused)) \
|
|
= vernum ? &map->l_versions[vernum[sym_index] & 0x7fff] : NULL; \
|
|
struct link_map *sym_map; \
|
|
sym_map = RESOLVE_MAP (&ref, version, reloc); \
|
|
ref ? sym_map->l_addr + ref->st_value : 0; \
|
|
})
|
|
|
|
if (map->l_info[VERSYMIDX (DT_VERSYM)] != NULL)
|
|
vernum = (const void *) D_PTR (map, l_info[VERSYMIDX (DT_VERSYM)]);
|
|
else
|
|
vernum = NULL;
|
|
|
|
got = (ElfW(Addr) *) D_PTR (map, l_info[DT_PLTGOT]);
|
|
|
|
n = map->l_info[DT_MIPS (LOCAL_GOTNO)]->d_un.d_val;
|
|
/* The dynamic linker's local got entries have already been relocated. */
|
|
if (map != &GL(dl_rtld_map))
|
|
{
|
|
/* got[0] is reserved. got[1] is also reserved for the dynamic object
|
|
generated by gnu ld. Skip these reserved entries from relocation. */
|
|
i = (got[1] & ELF_MIPS_GNU_GOT1_MASK)? 2 : 1;
|
|
|
|
/* Add the run-time displacement to all local got entries if
|
|
needed. */
|
|
if (__builtin_expect (map->l_addr != 0, 0))
|
|
{
|
|
while (i < n)
|
|
got[i++] += map->l_addr;
|
|
}
|
|
}
|
|
|
|
/* Handle global got entries. */
|
|
got += n;
|
|
/* Keep track of the symbol index. */
|
|
symidx = map->l_info[DT_MIPS (GOTSYM)]->d_un.d_val;
|
|
sym = (ElfW(Sym) *) D_PTR (map, l_info[DT_SYMTAB]) + symidx;
|
|
i = (map->l_info[DT_MIPS (SYMTABNO)]->d_un.d_val
|
|
- map->l_info[DT_MIPS (GOTSYM)]->d_un.d_val);
|
|
|
|
/* This loop doesn't handle Quickstart. */
|
|
while (i--)
|
|
{
|
|
if (sym->st_shndx == SHN_UNDEF)
|
|
{
|
|
if (ELFW(ST_TYPE) (sym->st_info) == STT_FUNC && sym->st_value
|
|
&& !(sym->st_other & STO_MIPS_PLT))
|
|
{
|
|
if (lazy)
|
|
*got = sym->st_value + map->l_addr;
|
|
else
|
|
/* This is a lazy-binding stub, so we don't need the
|
|
canonical address. */
|
|
*got = RESOLVE_GOTSYM (sym, vernum, symidx, R_MIPS_JUMP_SLOT);
|
|
}
|
|
else
|
|
*got = RESOLVE_GOTSYM (sym, vernum, symidx, R_MIPS_32);
|
|
}
|
|
else if (sym->st_shndx == SHN_COMMON)
|
|
*got = RESOLVE_GOTSYM (sym, vernum, symidx, R_MIPS_32);
|
|
else if (ELFW(ST_TYPE) (sym->st_info) == STT_FUNC
|
|
&& *got != sym->st_value)
|
|
{
|
|
if (lazy)
|
|
*got += map->l_addr;
|
|
else
|
|
/* This is a lazy-binding stub, so we don't need the
|
|
canonical address. */
|
|
*got = RESOLVE_GOTSYM (sym, vernum, symidx, R_MIPS_JUMP_SLOT);
|
|
}
|
|
else if (ELFW(ST_TYPE) (sym->st_info) == STT_SECTION)
|
|
{
|
|
if (sym->st_other == 0)
|
|
*got += map->l_addr;
|
|
}
|
|
else
|
|
*got = RESOLVE_GOTSYM (sym, vernum, symidx, R_MIPS_32);
|
|
|
|
++got;
|
|
++sym;
|
|
++symidx;
|
|
}
|
|
|
|
#undef RESOLVE_GOTSYM
|
|
}
|
|
#endif
|
|
|
|
/* 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
|
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ElfW(Addr) *got;
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extern void _dl_runtime_resolve (ElfW(Word));
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extern void _dl_runtime_pltresolve (void);
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extern int _dl_mips_gnu_objects;
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if (lazy)
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{
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/* The GOT entries for functions have not yet been filled in.
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Their initial contents will arrange when called to put an
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offset into the .dynsym section in t8, the return address
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in t7 and then jump to _GLOBAL_OFFSET_TABLE[0]. */
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got = (ElfW(Addr) *) D_PTR (l, l_info[DT_PLTGOT]);
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/* This function will get called to fix up the GOT entry indicated by
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the register t8, and then jump to the resolved address. */
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got[0] = (ElfW(Addr)) &_dl_runtime_resolve;
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/* Store l to _GLOBAL_OFFSET_TABLE[1] for gnu object. The MSB
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of got[1] of a gnu object is set to identify gnu objects.
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Where we can store l for non gnu objects? XXX */
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if ((got[1] & ELF_MIPS_GNU_GOT1_MASK) != 0)
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got[1] = ((ElfW(Addr)) l | ELF_MIPS_GNU_GOT1_MASK);
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else
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_dl_mips_gnu_objects = 0;
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}
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/* Relocate global offset table. */
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elf_machine_got_rel (l, lazy);
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/* If using PLTs, fill in the first two entries of .got.plt. */
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if (l->l_info[DT_JMPREL] && lazy)
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{
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ElfW(Addr) *gotplt;
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gotplt = (ElfW(Addr) *) D_PTR (l, l_info[DT_MIPS (PLTGOT)]);
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/* If a library is prelinked but we have to relocate anyway,
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we have to be able to undo the prelinking of .got.plt.
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The prelinker saved the address of .plt for us here. */
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if (gotplt[1])
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l->l_mach.plt = gotplt[1] + l->l_addr;
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gotplt[0] = (ElfW(Addr)) &_dl_runtime_pltresolve;
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gotplt[1] = (ElfW(Addr)) l;
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}
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# endif
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return lazy;
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}
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#endif /* RESOLVE_MAP */
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