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e0f4188600
* elf/do-rel.h (elf_dynamic_do_rel): Help the compiler recognize code which is never used when relocating ld.so itself. (_ELF_DYNAMIC_DO_RELOC): Help the compiler optimize a bit.
133 lines
4.5 KiB
C
133 lines
4.5 KiB
C
/* Do relocations for ELF dynamic linking.
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Copyright (C) 1995,96,97,98,99,2000,2001,2002 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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/* 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 RELCOUNT_IDX VERSYMIDX (DT_RELACOUNT)
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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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#else
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# define RELCOUNT_IDX VERSYMIDX (DT_RELCOUNT)
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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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#ifndef VALIDX
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# define VALIDX(tag) (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGNUM \
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+ DT_EXTRANUM + DT_VALTAGIDX (tag))
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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
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elf_dynamic_do_rel (struct link_map *map,
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ElfW(Addr) reladdr, ElfW(Addr) relsize,
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int lazy)
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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 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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elf_machine_lazy_rel (map, l_addr, r);
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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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ElfW(Word) nrelative = (map->l_info[RELCOUNT_IDX] == NULL
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? 0 : map->l_info[RELCOUNT_IDX]->d_un.d_val);
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const ElfW(Rel) *relative = r;
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r = MIN (r + nrelative, end);
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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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# ifndef DO_RELA
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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... */
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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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elf_machine_rel_relative (l_addr, relative,
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(void *) (l_addr + relative->r_offset));
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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)];
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elf_machine_rel (map, r, &symtab[ELFW(R_SYM) (r->r_info)],
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&map->l_versions[ndx],
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(void *) (l_addr + r->r_offset));
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}
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}
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#ifndef RTLD_BOOTSTRAP
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else
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for (; r < end; ++r)
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elf_machine_rel (map, r, &symtab[ELFW(R_SYM) (r->r_info)], NULL,
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(void *) (l_addr + r->r_offset));
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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 RELCOUNT_IDX
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