223 lines
7.0 KiB
C
223 lines
7.0 KiB
C
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/* Do relocations for ELF dynamic linking.
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Copyright (C) 1995-2022 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, see
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<https://www.gnu.org/licenses/>. */
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#include <ldsodefs.h>
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/* This file may be included twice, to define both
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`elf_dynamic_do_rel' and `elf_dynamic_do_rela'. */
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#ifdef DO_RELA
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# define elf_dynamic_do_Rel elf_dynamic_do_Rela
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# define Rel Rela
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# define elf_machine_rel elf_machine_rela
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# define elf_machine_rel_relative elf_machine_rela_relative
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#endif
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#ifndef DO_ELF_MACHINE_REL_RELATIVE
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# define DO_ELF_MACHINE_REL_RELATIVE(map, l_addr, relative) \
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elf_machine_rel_relative (l_addr, relative, \
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(void *) (l_addr + relative->r_offset))
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#endif
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/* Perform the relocations in MAP on the running program image as specified
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by RELTAG, SZTAG. If LAZY is nonzero, this is the first pass on PLT
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relocations; they should be set up to call _dl_runtime_resolve, rather
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than fully resolved now. */
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static inline void __attribute__ ((always_inline))
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elf_dynamic_do_Rel (struct link_map *map, struct r_scope_elem *scope[],
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const void *reladdr, ElfW(Addr) relsize,
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__typeof (((ElfW(Dyn) *) 0)->d_un.d_val) nrelative,
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int lazy, int skip_ifunc)
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{
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const ElfW(Rel) *r = (const void *) reladdr;
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const ElfW(Rel) *end = (const void *) (reladdr + relsize);
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ElfW(Addr) l_addr = map->l_addr;
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# if defined ELF_MACHINE_IRELATIVE && !defined RTLD_BOOTSTRAP
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const ElfW(Rel) *r2 = NULL;
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const ElfW(Rel) *end2 = NULL;
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# endif
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#if (!defined DO_RELA || !defined ELF_MACHINE_PLT_REL) && !defined RTLD_BOOTSTRAP
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/* We never bind lazily during ld.so bootstrap. Unfortunately gcc is
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not clever enough to see through all the function calls to realize
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that. */
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if (lazy)
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{
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/* Doing lazy PLT relocations; they need very little info. */
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for (; r < end; ++r)
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# ifdef ELF_MACHINE_IRELATIVE
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if (ELFW(R_TYPE) (r->r_info) == ELF_MACHINE_IRELATIVE)
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{
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if (r2 == NULL)
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r2 = r;
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end2 = r;
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}
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else
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# endif
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elf_machine_lazy_rel (map, scope, l_addr, r, skip_ifunc);
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# ifdef ELF_MACHINE_IRELATIVE
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if (r2 != NULL)
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for (; r2 <= end2; ++r2)
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if (ELFW(R_TYPE) (r2->r_info) == ELF_MACHINE_IRELATIVE)
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elf_machine_lazy_rel (map, scope, l_addr, r2, skip_ifunc);
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# endif
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}
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else
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#endif
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{
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const ElfW(Sym) *const symtab =
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(const void *) D_PTR (map, l_info[DT_SYMTAB]);
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const ElfW(Rel) *relative = r;
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r += nrelative;
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#ifndef RTLD_BOOTSTRAP
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/* This is defined in rtld.c, but nowhere in the static libc.a; make
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the reference weak so static programs can still link. This
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declaration cannot be done when compiling rtld.c (i.e. #ifdef
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RTLD_BOOTSTRAP) because rtld.c contains the common defn for
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_dl_rtld_map, which is incompatible with a weak decl in the same
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file. */
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# ifndef SHARED
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weak_extern (GL(dl_rtld_map));
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# endif
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if (map != &GL(dl_rtld_map)) /* Already done in rtld itself. */
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# if !defined DO_RELA || defined ELF_MACHINE_REL_RELATIVE
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/* Rela platforms get the offset from r_addend and this must
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be copied in the relocation address. Therefore we can skip
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the relative relocations only if this is for rel
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relocations or rela relocations if they are computed as
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memory_loc += l_addr... */
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if (l_addr != 0)
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# else
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/* ...or we know the object has been prelinked. */
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if (l_addr != 0 || ! map->l_info[VALIDX(DT_GNU_PRELINKED)])
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# endif
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#endif
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for (; relative < r; ++relative)
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DO_ELF_MACHINE_REL_RELATIVE (map, l_addr, relative);
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#ifdef RTLD_BOOTSTRAP
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/* The dynamic linker always uses versioning. */
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assert (map->l_info[VERSYMIDX (DT_VERSYM)] != NULL);
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#else
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if (map->l_info[VERSYMIDX (DT_VERSYM)])
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#endif
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{
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const ElfW(Half) *const version =
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(const void *) D_PTR (map, l_info[VERSYMIDX (DT_VERSYM)]);
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for (; r < end; ++r)
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{
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ElfW(Half) ndx = version[ELFW(R_SYM) (r->r_info)] & 0x7fff;
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const ElfW(Sym) *sym = &symtab[ELFW(R_SYM) (r->r_info)];
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void *const r_addr_arg = (void *) (l_addr + r->r_offset);
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const struct r_found_version *rversion = &map->l_versions[ndx];
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#if defined ELF_MACHINE_IRELATIVE && !defined RTLD_BOOTSTRAP
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if (ELFW(R_TYPE) (r->r_info) == ELF_MACHINE_IRELATIVE)
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{
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if (r2 == NULL)
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r2 = r;
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end2 = r;
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continue;
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}
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#endif
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elf_machine_rel (map, scope, r, sym, rversion, r_addr_arg,
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skip_ifunc);
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#if defined SHARED && !defined RTLD_BOOTSTRAP
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if (ELFW(R_TYPE) (r->r_info) == ELF_MACHINE_JMP_SLOT
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&& GLRO(dl_naudit) > 0)
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{
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struct link_map *sym_map
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= RESOLVE_MAP (map, scope, &sym, rversion,
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ELF_MACHINE_JMP_SLOT);
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if (sym != NULL)
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_dl_audit_symbind (map, NULL, sym, r_addr_arg, sym_map);
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}
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#endif
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}
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#if defined ELF_MACHINE_IRELATIVE && !defined RTLD_BOOTSTRAP
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if (r2 != NULL)
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for (; r2 <= end2; ++r2)
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if (ELFW(R_TYPE) (r2->r_info) == ELF_MACHINE_IRELATIVE)
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{
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ElfW(Half) ndx
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= version[ELFW(R_SYM) (r2->r_info)] & 0x7fff;
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elf_machine_rel (map, scope, r2,
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&symtab[ELFW(R_SYM) (r2->r_info)],
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&map->l_versions[ndx],
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(void *) (l_addr + r2->r_offset),
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skip_ifunc);
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}
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#endif
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}
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#ifndef RTLD_BOOTSTRAP
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else
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{
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for (; r < end; ++r)
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{
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const ElfW(Sym) *sym = &symtab[ELFW(R_SYM) (r->r_info)];
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void *const r_addr_arg = (void *) (l_addr + r->r_offset);
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# ifdef ELF_MACHINE_IRELATIVE
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if (ELFW(R_TYPE) (r->r_info) == ELF_MACHINE_IRELATIVE)
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{
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if (r2 == NULL)
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r2 = r;
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end2 = r;
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continue;
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}
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# endif
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elf_machine_rel (map, scope, r, sym, NULL, r_addr_arg,
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skip_ifunc);
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# if defined SHARED && !defined RTLD_BOOTSTRAP
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if (ELFW(R_TYPE) (r->r_info) == ELF_MACHINE_JMP_SLOT
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&& GLRO(dl_naudit) > 0)
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{
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struct link_map *sym_map
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= RESOLVE_MAP (map, scope, &sym,
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(struct r_found_version *) NULL,
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ELF_MACHINE_JMP_SLOT);
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if (sym != NULL)
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_dl_audit_symbind (map, NULL , sym,r_addr_arg, sym_map);
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}
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# endif
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}
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# ifdef ELF_MACHINE_IRELATIVE
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if (r2 != NULL)
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for (; r2 <= end2; ++r2)
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if (ELFW(R_TYPE) (r2->r_info) == ELF_MACHINE_IRELATIVE)
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elf_machine_rel (map, scope, r2, &symtab[ELFW(R_SYM) (r2->r_info)],
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NULL, (void *) (l_addr + r2->r_offset),
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skip_ifunc);
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# endif
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}
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#endif
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}
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}
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#undef elf_dynamic_do_Rel
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#undef Rel
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#undef elf_machine_rel
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#undef elf_machine_rel_relative
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#undef DO_ELF_MACHINE_REL_RELATIVE
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#undef DO_RELA
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