mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-23 05:20:06 +00:00
e89913d0aa
The RTLD_BOOTSTRAP branch is used to relocate ld.so itself. It only needs to handle RELATIVE, GLOB_DAT, and JUMP_SLOT. TLSDESC/TLS_DTPMOD/TLS_DTPREL handling can be removed. Remove `case AARCH64_R(RELATIVE)` as well as elf_machine_rela has checked it. Tested on aarch64-linux-gnu.
375 lines
11 KiB
C
375 lines
11 KiB
C
/* 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 License as
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published by the Free Software Foundation; either version 2.1 of the
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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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#ifndef dl_machine_h
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#define dl_machine_h
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#define ELF_MACHINE_NAME "aarch64"
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#include <sysdep.h>
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#include <tls.h>
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#include <dl-tlsdesc.h>
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#include <dl-static-tls.h>
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#include <dl-irel.h>
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#include <dl-machine-rel.h>
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#include <cpu-features.c>
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/* Translate a processor specific dynamic tag to the index in l_info array. */
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#define DT_AARCH64(x) (DT_AARCH64_##x - DT_LOPROC + DT_NUM)
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/* Return nonzero iff ELF header is compatible with the running host. */
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static inline int __attribute__ ((unused))
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elf_machine_matches_host (const ElfW(Ehdr) *ehdr)
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{
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return ehdr->e_machine == EM_AARCH64;
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}
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/* Return the run-time load address of the shared object. */
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static inline ElfW(Addr) __attribute__ ((unused))
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elf_machine_load_address (void)
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{
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extern const ElfW(Ehdr) __ehdr_start attribute_hidden;
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return (ElfW(Addr)) &__ehdr_start;
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}
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/* Return the link-time address of _DYNAMIC. */
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static inline ElfW(Addr) __attribute__ ((unused))
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elf_machine_dynamic (void)
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{
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extern ElfW(Dyn) _DYNAMIC[] attribute_hidden;
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return (ElfW(Addr)) _DYNAMIC - elf_machine_load_address ();
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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__ ((unused))
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elf_machine_runtime_setup (struct link_map *l, struct r_scope_elem *scope[],
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int lazy, int profile)
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{
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if (l->l_info[DT_JMPREL] && lazy)
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{
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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_profile (ElfW(Word));
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got = (ElfW(Addr) *) D_PTR (l, l_info[DT_PLTGOT]);
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if (got[1])
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{
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l->l_mach.plt = got[1] + l->l_addr;
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}
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got[1] = (ElfW(Addr)) l;
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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] = (ElfW(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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/* Say that we really want profiling and the timers are
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started. */
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GL(dl_profile_map) = l;
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}
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else
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{
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/* This function will get called to fix up the GOT entry
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indicated by the offset on the stack, and then jump to
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the resolved address. */
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got[2] = (ElfW(Addr)) &_dl_runtime_resolve;
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}
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}
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return lazy;
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}
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/* In elf/rtld.c _dl_start should be global so dl-start.S can reference it. */
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#define RTLD_START asm (".globl _dl_start");
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#define elf_machine_type_class(type) \
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((((type) == R_AARCH64_JUMP_SLOT || \
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(type) == R_AARCH64_TLS_DTPMOD || \
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(type) == R_AARCH64_TLS_DTPREL || \
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(type) == R_AARCH64_TLS_TPREL || \
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(type) == R_AARCH64_TLSDESC) * ELF_RTYPE_CLASS_PLT) \
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#define ELF_MACHINE_JMP_SLOT AARCH64_R(JUMP_SLOT)
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#define DL_PLATFORM_INIT dl_platform_init ()
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static inline void __attribute__ ((unused))
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dl_platform_init (void)
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{
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if (GLRO(dl_platform) != NULL && *GLRO(dl_platform) == '\0')
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/* Avoid an empty string which would disturb us. */
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GLRO(dl_platform) = NULL;
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#ifdef SHARED
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/* init_cpu_features has been called early from __libc_start_main in
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static executable. */
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init_cpu_features (&GLRO(dl_aarch64_cpu_features));
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#endif
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}
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static inline ElfW(Addr)
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elf_machine_fixup_plt (struct link_map *map, lookup_t t,
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const ElfW(Sym) *refsym, const ElfW(Sym) *sym,
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const ElfW(Rela) *reloc,
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ElfW(Addr) *reloc_addr,
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ElfW(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. */
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static inline ElfW(Addr)
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elf_machine_plt_value (struct link_map *map,
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const ElfW(Rela) *reloc,
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ElfW(Addr) value)
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{
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return value;
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}
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#endif
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/* Names of the architecture-specific auditing callback functions. */
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#define ARCH_LA_PLTENTER aarch64_gnu_pltenter
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#define ARCH_LA_PLTEXIT aarch64_gnu_pltexit
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#ifdef RESOLVE_MAP
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static inline void
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__attribute__ ((always_inline))
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elf_machine_rela (struct link_map *map, struct r_scope_elem *scope[],
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const ElfW(Rela) *reloc, const ElfW(Sym) *sym,
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const struct r_found_version *version,
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void *const reloc_addr_arg, int skip_ifunc)
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{
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ElfW(Addr) *const reloc_addr = reloc_addr_arg;
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const unsigned int r_type = ELFW (R_TYPE) (reloc->r_info);
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if (__builtin_expect (r_type == AARCH64_R(RELATIVE), 0))
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*reloc_addr = map->l_addr + reloc->r_addend;
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else if (__builtin_expect (r_type == R_AARCH64_NONE, 0))
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return;
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else
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{
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# ifndef RTLD_BOOTSTRAP
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const ElfW(Sym) *const refsym = sym;
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# endif
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struct link_map *sym_map = RESOLVE_MAP (map, scope, &sym, version,
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r_type);
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ElfW(Addr) value = SYMBOL_ADDRESS (sym_map, sym, true);
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if (sym != NULL
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&& __glibc_unlikely (ELFW(ST_TYPE) (sym->st_info) == STT_GNU_IFUNC)
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&& __glibc_likely (sym->st_shndx != SHN_UNDEF)
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&& __glibc_likely (!skip_ifunc))
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value = elf_ifunc_invoke (value);
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switch (r_type)
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{
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case AARCH64_R(GLOB_DAT):
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case AARCH64_R(JUMP_SLOT):
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*reloc_addr = value + reloc->r_addend;
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break;
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# ifndef RTLD_BOOTSTRAP
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case AARCH64_R(ABS32):
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# ifdef __LP64__
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case AARCH64_R(ABS64):
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# endif
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*reloc_addr = value + reloc->r_addend;
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break;
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case AARCH64_R(COPY):
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if (sym == NULL)
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break;
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if (sym->st_size > refsym->st_size
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|| (GLRO(dl_verbose) && sym->st_size < refsym->st_size))
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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, strtab + refsym->st_name);
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}
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memcpy (reloc_addr_arg, (void *) value,
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sym->st_size < refsym->st_size
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? sym->st_size : refsym->st_size);
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break;
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case AARCH64_R(TLSDESC):
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{
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struct tlsdesc volatile *td =
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(struct tlsdesc volatile *)reloc_addr;
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if (! sym)
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{
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td->arg = (void*)reloc->r_addend;
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td->entry = _dl_tlsdesc_undefweak;
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}
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else
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{
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# ifndef SHARED
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CHECK_STATIC_TLS (map, sym_map);
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# else
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if (!TRY_STATIC_TLS (map, sym_map))
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{
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td->arg = _dl_make_tlsdesc_dynamic
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(sym_map, sym->st_value + reloc->r_addend);
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td->entry = _dl_tlsdesc_dynamic;
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}
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else
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# endif
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{
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td->arg = (void*)(sym->st_value + sym_map->l_tls_offset
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+ reloc->r_addend);
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td->entry = _dl_tlsdesc_return;
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}
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}
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break;
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}
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case AARCH64_R(TLS_DTPMOD):
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if (sym_map != NULL)
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{
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*reloc_addr = sym_map->l_tls_modid;
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}
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break;
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case AARCH64_R(TLS_DTPREL):
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if (sym)
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*reloc_addr = sym->st_value + reloc->r_addend;
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break;
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case AARCH64_R(TLS_TPREL):
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if (sym)
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{
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CHECK_STATIC_TLS (map, sym_map);
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*reloc_addr =
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sym->st_value + reloc->r_addend + sym_map->l_tls_offset;
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}
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break;
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case AARCH64_R(IRELATIVE):
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value = map->l_addr + reloc->r_addend;
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if (__glibc_likely (!skip_ifunc))
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value = elf_ifunc_invoke (value);
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*reloc_addr = value;
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break;
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# endif /* !RTLD_BOOTSTRAP */
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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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static inline void
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__attribute__ ((always_inline))
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elf_machine_rela_relative (ElfW(Addr) l_addr,
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const ElfW(Rela) *reloc,
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void *const reloc_addr_arg)
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{
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ElfW(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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static inline void
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__attribute__ ((always_inline))
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elf_machine_lazy_rel (struct link_map *map, struct r_scope_elem *scope[],
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ElfW(Addr) l_addr,
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const ElfW(Rela) *reloc,
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int skip_ifunc)
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{
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ElfW(Addr) *const reloc_addr = (void *) (l_addr + reloc->r_offset);
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const unsigned int r_type = ELFW (R_TYPE) (reloc->r_info);
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/* Check for unexpected PLT reloc type. */
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if (__builtin_expect (r_type == AARCH64_R(JUMP_SLOT), 1))
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{
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if (__glibc_unlikely (map->l_info[DT_AARCH64 (VARIANT_PCS)] != NULL))
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{
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/* Check the symbol table for variant PCS symbols. */
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const Elf_Symndx symndx = ELFW (R_SYM) (reloc->r_info);
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const ElfW (Sym) *symtab =
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(const void *)D_PTR (map, l_info[DT_SYMTAB]);
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const ElfW (Sym) *sym = &symtab[symndx];
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if (__glibc_unlikely (sym->st_other & STO_AARCH64_VARIANT_PCS))
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{
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/* Avoid lazy resolution of variant PCS symbols. */
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const struct r_found_version *version = NULL;
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if (map->l_info[VERSYMIDX (DT_VERSYM)] != NULL)
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{
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const ElfW (Half) *vernum =
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(const void *)D_PTR (map, l_info[VERSYMIDX (DT_VERSYM)]);
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version = &map->l_versions[vernum[symndx] & 0x7fff];
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}
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elf_machine_rela (map, scope, reloc, sym, version, reloc_addr,
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skip_ifunc);
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return;
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}
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}
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if (map->l_mach.plt == 0)
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*reloc_addr += l_addr;
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else
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*reloc_addr = map->l_mach.plt;
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}
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else if (__builtin_expect (r_type == AARCH64_R(TLSDESC), 1))
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{
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const Elf_Symndx symndx = ELFW (R_SYM) (reloc->r_info);
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const ElfW (Sym) *symtab = (const void *)D_PTR (map, l_info[DT_SYMTAB]);
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const ElfW (Sym) *sym = &symtab[symndx];
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const struct r_found_version *version = NULL;
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if (map->l_info[VERSYMIDX (DT_VERSYM)] != NULL)
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{
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const ElfW (Half) *vernum =
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(const void *)D_PTR (map, l_info[VERSYMIDX (DT_VERSYM)]);
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version = &map->l_versions[vernum[symndx] & 0x7fff];
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}
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/* Always initialize TLS descriptors completely, because lazy
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initialization requires synchronization at every TLS access. */
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elf_machine_rela (map, scope, reloc, sym, version, reloc_addr,
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skip_ifunc);
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}
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else if (__glibc_unlikely (r_type == AARCH64_R(IRELATIVE)))
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{
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ElfW(Addr) value = map->l_addr + reloc->r_addend;
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if (__glibc_likely (!skip_ifunc))
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value = elf_ifunc_invoke (value);
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*reloc_addr = value;
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}
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else
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_dl_reloc_bad_type (map, r_type, 1);
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}
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#endif
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