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2001-12-11 Jakub Jelinek <jakub@redhat.com> * elf/Makefile (dl-routines): Add conflict. (rtld-ldscript-in, rtld-ldscript, rtld-parms): Remove. (ld.so): Add _begin local symbol. * elf/elf.h (DT_VALTAGIDX, DT_VALNUM, DT_ADDRTAGIDX, DT_ADDRNUM): Define. * elf/dl-deps.c (_dl_build_local_scope): New. (_dl_map_object_deps): If LD_TRACE_PRELINKING, compute local scopes of all libraries. * elf/do-rel.h (VALIDX): Define. (elf_dynamic_do_rel): If ELF_MACHINE_PLT_REL is defined, don't do lazy binding for RELA. If DT_GNU_PRELINKED, DT_RELACOUNT relocations can be skipped. * elf/dl-conflict.c: New file. * elf/dl-lookup.c (_dl_debug_bindings): New. (_dl_lookup_symbol): Use _dl_debug_bindings. Reference_name is always non-NULL. (_dl_lookup_symbol_skip): Likewise. (_dl_lookup_versioned_symbol): Likewise. (_dl_lookup_versioned_symbol_skip): Likewise. * elf/dl-runtime.c (PLTREL): If ELF_MACHINE_PLT_REL is defined, define to ElfW(Rel). * elf/dynamic-link.h (elf_get_dynamic_info): Record selected dynamic tags in the DT_VALRNGLO..DT_VALRNGHI and DT_ADDRRNGLO..DT_ADDRRNGHI ranges. Don't adjust address dynamic tags if l_addr is 0. * elf/rtld.c (_dl_trace_prelink, _dl_trace_prelink_map): New variables. (_dl_start): Skip ELF_DYNAMIC_RELOCATE if ld.so is prelinked. (VALIDX, ADDRIDX): Define. (_dl_start_final): Initialize _dl_rtld_map's l_map_start and l_map_end. (dl_main): Print library list for LD_TRACE_PRELINKING. If prelinking information can be used, skip relocating libraries and call _dl_resolve_conflicts instead. (process_envvars): Handle LD_TRACE_PRELINKING envvar. * elf/dl-load.c (_dl_map_object): Don't create fake libs if LD_TRACE_PRELINKING. * include/link.h (struct link_map) [l_info]: Add DT_VALNUM + DT_ADDRNUM. * sysdeps/generic/ldsodefs.h (_dl_trace_prelink_map): New declaration. (DL_DEBUG_PRELINK): Define. (_dl_resolve_conflicts): Add prototype. * sysdeps/alpha/dl-machine.h (elf_machine_runtime_setup): Reinitialize .plt for prelinked libraries where prelinking info cannot be used. (elf_machine_rela): If relocating R_ALPHA_JMP_SLOT in .gnu.conflict section, use RESOLVE_CONFLICT_FIND_MAP to find out reloc's link_map. * sysdeps/arm/bits/link.h: New file. * sysdeps/arm/dl-machine.h (elf_machine_runtime_setup): Save original content of .got[1]. (ELF_MACHINE_NO_RELA): Only define if RTLD_BOOTSTRAP. (ELF_MACHINE_PLT_REL): Define. (elf_machine_rela, elf_machine_rela_relative): New. (elf_machine_lazy_rel): Reinitialize R_ARM_JUMP_SLOT address instead of adjusting it if prelinked and prelinking cannot be used. * sysdeps/i386/bits/link.h: New file. * sysdeps/i386/dl-machine.h (elf_machine_runtime_setup): Save original content of .got[1]. (ELF_MACHINE_NO_RELA): Only define if RTLD_BOOTSTRAP. (ELF_MACHINE_PLT_REL): Define. (elf_machine_rela, elf_machine_rela_relative): New. (elf_machine_lazy_rel): Reinitialize R_386_JUMP_SLOT address instead of adjusting it if prelinked and prelinking cannot be used. * sysdeps/powerpc/dl-machine.h (elf_machine_rela): If relocating conflicts, skip finaladdr computation. Use RESOLVE_CONFLICT_FIND_MAP to find out map for R_PPC_JMP_SLOT relocs. * sysdeps/sparc/sparc32/dl-machine.h (VALIDX): Define. (OPCODE_BA): Define. (elf_machine_runtime_setup): Reinitialize .plt for prelinked libraries where prelinking info cannot be used. (sparc_fixup_plt): Renamed from elf_machine_fixup_plt. (elf_machine_fixup_plt): Call sparc_fixup_plt. (elf_machine_rela): Set value to 0 if relocating conflicts. Call sparc_fixup_plt for R_SPARC_JMP_SLOT. * sysdeps/sparc/sparc64/dl-machine.h (VALIDX): Define. (sparc64_fixup_plt): Fix a typo. (elf_machine_rela): Set value to 0 if relocating conflicts. Handle R_SPARC_JMP_SLOT relocs when relocating conflicts. (elf_machine_runtime_setup): Reinitialize .plt for prelinked libraries where prelinking info cannot be used. * sysdeps/sh/bits/link.h: New file. * sysdeps/sh/dl-machine.h (elf_machine_runtime_setup): Save original content of .got[1]. (elf_machine_lazy_rel): Reinitialize R_SH_JMP_SLOT address instead of adjusting it if prelinked and prelinking cannot be used. * sysdeps/s390/s390-32/bits/link.h: New file. * sysdeps/s390/s390-32/dl-machine.h (elf_machine_runtime_setup): Save original content of .got[1]. (elf_machine_lazy_rel): Reinitialize R_390_JMP_SLOT address instead of adjusting it if prelinked and prelinking cannot be used. * sysdeps/s390/s390-64/bits/link.h: New file. * sysdeps/s390/s390-64/dl-machine.h (elf_machine_runtime_setup): Save original content of .got[1]. (elf_machine_lazy_rel): Reinitialize R_390_JMP_SLOT address instead of adjusting it if prelinked and prelinking cannot be used. * sysdeps/x86_64/bits/link.h: New file. * sysdeps/x86_64/dl-machine.h (elf_machine_runtime_setup): Save original content of .got[1]. (elf_machine_lazy_rel): Reinitialize R_X86_64_JMP_SLOT address instead of adjusting it if prelinked and prelinking cannot be used.
231 lines
7.5 KiB
C
231 lines
7.5 KiB
C
/* On-demand PLT fixup for shared objects.
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Copyright (C) 1995-1999, 2000, 2001 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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#include <alloca.h>
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#include <stdlib.h>
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#include <unistd.h>
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#include <ldsodefs.h>
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#include "dynamic-link.h"
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#if (!defined ELF_MACHINE_NO_RELA && !defined ELF_MACHINE_PLT_REL) \
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|| ELF_MACHINE_NO_REL
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# define PLTREL ElfW(Rela)
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#else
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# define PLTREL ElfW(Rel)
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#endif
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#ifndef VERSYMIDX
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# define VERSYMIDX(sym) (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGIDX (sym))
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#endif
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/* This function is called through a special trampoline from the PLT the
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first time each PLT entry is called. We must perform the relocation
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specified in the PLT of the given shared object, and return the resolved
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function address to the trampoline, which will restart the original call
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to that address. Future calls will bounce directly from the PLT to the
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function. */
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#ifndef ELF_MACHINE_NO_PLT
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static ElfW(Addr) __attribute_used__
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fixup (
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# ifdef ELF_MACHINE_RUNTIME_FIXUP_ARGS
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ELF_MACHINE_RUNTIME_FIXUP_ARGS,
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# endif
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/* GKM FIXME: Fix trampoline to pass bounds so we can do
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without the `__unbounded' qualifier. */
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struct link_map *__unbounded l, ElfW(Word) reloc_offset)
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{
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const ElfW(Sym) *const symtab
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= (const void *) D_PTR (l, l_info[DT_SYMTAB]);
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const char *strtab = (const void *) D_PTR (l, l_info[DT_STRTAB]);
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const PLTREL *const reloc
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= (const void *) (D_PTR (l, l_info[DT_JMPREL]) + reloc_offset);
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const ElfW(Sym) *sym = &symtab[ELFW(R_SYM) (reloc->r_info)];
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void *const rel_addr = (void *)(l->l_addr + reloc->r_offset);
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lookup_t result;
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ElfW(Addr) value;
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/* The use of `alloca' here looks ridiculous but it helps. The goal is
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to prevent the function from being inlined and thus optimized out.
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There is no official way to do this so we use this trick. gcc never
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inlines functions which use `alloca'. */
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alloca (sizeof (int));
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/* Sanity check that we're really looking at a PLT relocation. */
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assert (ELFW(R_TYPE)(reloc->r_info) == ELF_MACHINE_JMP_SLOT);
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/* Look up the target symbol. If the normal lookup rules are not
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used don't look in the global scope. */
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if (__builtin_expect (ELFW(ST_VISIBILITY) (sym->st_other), 0) == 0)
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{
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switch (l->l_info[VERSYMIDX (DT_VERSYM)] != NULL)
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{
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default:
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{
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const ElfW(Half) *vernum =
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(const void *) D_PTR (l, l_info[VERSYMIDX (DT_VERSYM)]);
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ElfW(Half) ndx = vernum[ELFW(R_SYM) (reloc->r_info)];
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const struct r_found_version *version = &l->l_versions[ndx];
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if (version->hash != 0)
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{
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result = _dl_lookup_versioned_symbol (strtab + sym->st_name,
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l, &sym, l->l_scope,
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version,
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ELF_RTYPE_CLASS_PLT, 0);
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break;
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}
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}
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case 0:
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result = _dl_lookup_symbol (strtab + sym->st_name, l, &sym,
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l->l_scope, ELF_RTYPE_CLASS_PLT, 0);
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}
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/* Currently result contains the base load address (or link map)
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of the object that defines sym. Now add in the symbol
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offset. */
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value = (sym ? LOOKUP_VALUE_ADDRESS (result) + sym->st_value : 0);
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}
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else
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{
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/* We already found the symbol. The module (and therefore its load
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address) is also known. */
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value = l->l_addr + sym->st_value;
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#ifdef DL_LOOKUP_RETURNS_MAP
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result = l;
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#endif
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}
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/* And now perhaps the relocation addend. */
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value = elf_machine_plt_value (l, reloc, value);
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/* Finally, fix up the plt itself. */
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if (__builtin_expect (_dl_bind_not, 0))
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return value;
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return elf_machine_fixup_plt (l, result, reloc, rel_addr, value);
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}
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#endif
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#if !defined PROF && !defined ELF_MACHINE_NO_PLT && !__BOUNDED_POINTERS__
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static ElfW(Addr) __attribute_used__
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profile_fixup (
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#ifdef ELF_MACHINE_RUNTIME_FIXUP_ARGS
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ELF_MACHINE_RUNTIME_FIXUP_ARGS,
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#endif
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struct link_map *l, ElfW(Word) reloc_offset, ElfW(Addr) retaddr)
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{
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void (*mcount_fct) (ElfW(Addr), ElfW(Addr)) = _dl_mcount;
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ElfW(Addr) *resultp;
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lookup_t result;
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ElfW(Addr) value;
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/* The use of `alloca' here looks ridiculous but it helps. The goal is
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to prevent the function from being inlined, and thus optimized out.
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There is no official way to do this so we use this trick. gcc never
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inlines functions which use `alloca'. */
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alloca (sizeof (int));
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/* This is the address in the array where we store the result of previous
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relocations. */
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resultp = &l->l_reloc_result[reloc_offset / sizeof (PLTREL)];
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value = *resultp;
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if (value == 0)
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{
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/* This is the first time we have to relocate this object. */
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const ElfW(Sym) *const symtab
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= (const void *) D_PTR (l, l_info[DT_SYMTAB]);
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const char *strtab = (const void *) D_PTR (l, l_info[DT_STRTAB]);
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const PLTREL *const reloc
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= (const void *) (D_PTR (l, l_info[DT_JMPREL]) + reloc_offset);
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const ElfW(Sym) *sym = &symtab[ELFW(R_SYM) (reloc->r_info)];
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/* Sanity check that we're really looking at a PLT relocation. */
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assert (ELFW(R_TYPE)(reloc->r_info) == ELF_MACHINE_JMP_SLOT);
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/* Look up the target symbol. If the symbol is marked STV_PROTECTED
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don't look in the global scope. */
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if (__builtin_expect (ELFW(ST_VISIBILITY) (sym->st_other), 0) == 0)
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{
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switch (l->l_info[VERSYMIDX (DT_VERSYM)] != NULL)
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{
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default:
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{
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const ElfW(Half) *vernum =
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(const void *) D_PTR (l,l_info[VERSYMIDX (DT_VERSYM)]);
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ElfW(Half) ndx = vernum[ELFW(R_SYM) (reloc->r_info)];
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const struct r_found_version *version = &l->l_versions[ndx];
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if (version->hash != 0)
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{
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result = _dl_lookup_versioned_symbol(strtab + sym->st_name,
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l, &sym, l->l_scope,
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version,
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ELF_RTYPE_CLASS_PLT,
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0);
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break;
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}
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}
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case 0:
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result = _dl_lookup_symbol (strtab + sym->st_name, l, &sym,
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l->l_scope, ELF_RTYPE_CLASS_PLT, 0);
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}
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/* Currently result contains the base load address (or link map)
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of the object that defines sym. Now add in the symbol
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offset. */
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value = (sym ? LOOKUP_VALUE_ADDRESS (result) + sym->st_value : 0);
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}
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else
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{
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/* We already found the symbol. The module (and therefore its load
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address) is also known. */
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value = l->l_addr + sym->st_value;
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#ifdef DL_LOOKUP_RETURNS_MAP
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result = l;
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#endif
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}
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/* And now perhaps the relocation addend. */
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value = elf_machine_plt_value (l, reloc, value);
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/* Store the result for later runs. */
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if (__builtin_expect (! _dl_bind_not, 1))
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*resultp = value;
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}
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(*mcount_fct) (retaddr, value);
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return value;
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}
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#endif /* PROF && ELF_MACHINE_NO_PLT */
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/* This macro is defined in dl-machine.h to define the entry point called
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by the PLT. The `fixup' function above does the real work, but a little
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more twiddling is needed to get the stack right and jump to the address
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finally resolved. */
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ELF_MACHINE_RUNTIME_TRAMPOLINE
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