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135 lines
4.1 KiB
C
135 lines
4.1 KiB
C
/* Machine-dependent ELF dynamic relocation inline functions. Stub version.
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Copyright (C) 1995-2020 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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#define ELF_MACHINE_NAME "stub"
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#include <string.h>
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#include <link.h>
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/* Return nonzero iff ELF header is compatible with the running host. */
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static inline int
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elf_machine_matches_host (const Elf32_Ehdr *ehdr)
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{
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switch (ehdr->e_machine)
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{
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default:
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return 0;
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}
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}
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/* Return the link-time address of _DYNAMIC. */
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static inline Elf32_Addr
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elf_machine_dynamic (void)
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{
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#error "Damn, no _DYNAMIC"
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}
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/* Return the run-time load address of the shared object. */
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static inline Elf32_Addr
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elf_machine_load_address (void)
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{
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#error "Where am I?"
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}
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/* Fixup a PLT entry to bounce directly to the function at VALUE. */
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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(Rel) *reloc,
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ElfW(Addr) *reloc_addr, ElfW(Addr) value)
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{
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return *reloc_addr = value;
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}
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/* Perform the relocation specified by RELOC and SYM (which is fully resolved).
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LOADADDR is the load address of the object; INFO is an array indexed
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by DT_* of the .dynamic section info. */
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auto inline void
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__attribute__ ((always_inline))
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elf_machine_rel (Elf32_Addr loadaddr, Elf32_Dyn *info[DT_NUM],
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const Elf32_Rel *reloc, const Elf32_Sym *sym,
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Elf32_Addr (*resolve) (const Elf32_Sym **ref,
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Elf32_Addr reloc_addr,
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int noplt))
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{
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Elf32_Addr *const reloc_addr = (Elf32_Addr *) reloc->r_offset;
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Elf32_Addr loadbase;
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switch (ELF32_R_TYPE (reloc->r_info))
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{
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case R_MACHINE_COPY:
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loadbase = (*resolve) (&sym, (Elf32_Addr) reloc_addr, 0);
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memcpy (reloc_addr, (void *) (loadbase + sym->st_value), sym->st_size);
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break;
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default:
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_dl_reloc_bad_type (map, ELF32_R_TYPE (reloc->r_info), 0);
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break;
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}
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}
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auto inline Elf32_Addr
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__attribute__ ((always_inline))
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elf_machine_rela (Elf32_Addr loadaddr, Elf32_Dyn *info[DT_NUM],
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const Elf32_Rel *reloc, const Elf32_Sym *sym,
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Elf32_Addr (*resolve) (const Elf32_Sym **ref,
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Elf32_Addr reloc_addr,
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int noplt))
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{
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_dl_signal_error (0, "Elf32_Rela relocation requested -- unused on "
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NULL, ELF_MACHINE_NAME);
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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
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elf_machine_runtime_setup (struct link_map *l, int lazy)
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{
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extern void _dl_runtime_resolve (Elf32_Word);
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if (lazy)
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{
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/* The GOT entries for functions in the PLT have not yet been filled
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in. Their initial contents will arrange when called to push an
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offset into the .rel.plt section, push _GLOBAL_OFFSET_TABLE_[1],
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and then jump to _GLOBAL_OFFSET_TABLE[2]. */
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Elf32_Addr *got = (Elf32_Addr *) D_PTR (l, l_info[DT_PLTGOT]);
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got[1] = (Elf32_Addr) l; /* Identify this shared object. */
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/* This function will get called to fix up the GOT entry indicated by
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the offset on the stack, and then jump to the resolved address. */
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got[2] = (Elf32_Addr) &_dl_runtime_resolve;
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}
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return lazy;
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}
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/* Initial entry point code for the dynamic linker.
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The C function `_dl_start' is the real entry point;
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its return value is the user program's entry point. */
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#define RTLD_START #error need some startup code
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