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Diffstat (limited to 'REORG.TODO/elf/dynamic-link.h')
| -rw-r--r-- | REORG.TODO/elf/dynamic-link.h | 203 |
1 files changed, 203 insertions, 0 deletions
diff --git a/REORG.TODO/elf/dynamic-link.h b/REORG.TODO/elf/dynamic-link.h new file mode 100644 index 0000000000..60f2d91151 --- /dev/null +++ b/REORG.TODO/elf/dynamic-link.h @@ -0,0 +1,203 @@ +/* Inline functions for dynamic linking. + Copyright (C) 1995-2017 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +/* This macro is used as a callback from elf_machine_rel{a,} when a + static TLS reloc is about to be performed. Since (in dl-load.c) we + permit dynamic loading of objects that might use such relocs, we + have to check whether each use is actually doable. If the object + whose TLS segment the reference resolves to was allocated space in + the static TLS block at startup, then it's ok. Otherwise, we make + an attempt to allocate it in surplus space on the fly. If that + can't be done, we fall back to the error that DF_STATIC_TLS is + intended to produce. */ +#define HAVE_STATIC_TLS(map, sym_map) \ + (__builtin_expect ((sym_map)->l_tls_offset != NO_TLS_OFFSET \ + && ((sym_map)->l_tls_offset \ + != FORCED_DYNAMIC_TLS_OFFSET), 1)) + +#define CHECK_STATIC_TLS(map, sym_map) \ + do { \ + if (!HAVE_STATIC_TLS (map, sym_map)) \ + _dl_allocate_static_tls (sym_map); \ + } while (0) + +#define TRY_STATIC_TLS(map, sym_map) \ + (__builtin_expect ((sym_map)->l_tls_offset \ + != FORCED_DYNAMIC_TLS_OFFSET, 1) \ + && (__builtin_expect ((sym_map)->l_tls_offset != NO_TLS_OFFSET, 1) \ + || _dl_try_allocate_static_tls (sym_map) == 0)) + +int internal_function attribute_hidden + _dl_try_allocate_static_tls (struct link_map *map); + +#include <elf.h> + +#ifdef RESOLVE_MAP +/* We pass reloc_addr as a pointer to void, as opposed to a pointer to + ElfW(Addr), because not all architectures can assume that the + relocated address is properly aligned, whereas the compiler is + entitled to assume that a pointer to a type is properly aligned for + the type. Even if we cast the pointer back to some other type with + less strict alignment requirements, the compiler might still + remember that the pointer was originally more aligned, thereby + optimizing away alignment tests or using word instructions for + copying memory, breaking the very code written to handle the + unaligned cases. */ +# if ! ELF_MACHINE_NO_REL +auto inline void __attribute__((always_inline)) +elf_machine_rel (struct link_map *map, const ElfW(Rel) *reloc, + const ElfW(Sym) *sym, const struct r_found_version *version, + void *const reloc_addr, int skip_ifunc); +auto inline void __attribute__((always_inline)) +elf_machine_rel_relative (ElfW(Addr) l_addr, const ElfW(Rel) *reloc, + void *const reloc_addr); +# endif +# if ! ELF_MACHINE_NO_RELA +auto inline void __attribute__((always_inline)) +elf_machine_rela (struct link_map *map, const ElfW(Rela) *reloc, + const ElfW(Sym) *sym, const struct r_found_version *version, + void *const reloc_addr, int skip_ifunc); +auto inline void __attribute__((always_inline)) +elf_machine_rela_relative (ElfW(Addr) l_addr, const ElfW(Rela) *reloc, + void *const reloc_addr); +# endif +# if ELF_MACHINE_NO_RELA || defined ELF_MACHINE_PLT_REL +auto inline void __attribute__((always_inline)) +elf_machine_lazy_rel (struct link_map *map, + ElfW(Addr) l_addr, const ElfW(Rel) *reloc, + int skip_ifunc); +# else +auto inline void __attribute__((always_inline)) +elf_machine_lazy_rel (struct link_map *map, + ElfW(Addr) l_addr, const ElfW(Rela) *reloc, + int skip_ifunc); +# endif +#endif + +#include <dl-machine.h> + +#include "get-dynamic-info.h" + +#ifdef RESOLVE_MAP + +# ifdef RTLD_BOOTSTRAP +# define ELF_DURING_STARTUP (1) +# else +# define ELF_DURING_STARTUP (0) +# endif + +/* Get the definitions of `elf_dynamic_do_rel' and `elf_dynamic_do_rela'. + These functions are almost identical, so we use cpp magic to avoid + duplicating their code. It cannot be done in a more general function + because we must be able to completely inline. */ + +/* On some machines, notably SPARC, DT_REL* includes DT_JMPREL in its + range. Note that according to the ELF spec, this is completely legal! + + We are guarenteed that we have one of three situations. Either DT_JMPREL + comes immediately after DT_REL*, or there is overlap and DT_JMPREL + consumes precisely the very end of the DT_REL*, or DT_JMPREL and DT_REL* + are completely separate and there is a gap between them. */ + +# define _ELF_DYNAMIC_DO_RELOC(RELOC, reloc, map, do_lazy, skip_ifunc, test_rel) \ + do { \ + struct { ElfW(Addr) start, size; \ + __typeof (((ElfW(Dyn) *) 0)->d_un.d_val) nrelative; int lazy; } \ + ranges[2] = { { 0, 0, 0, 0 }, { 0, 0, 0, 0 } }; \ + \ + if ((map)->l_info[DT_##RELOC]) \ + { \ + ranges[0].start = D_PTR ((map), l_info[DT_##RELOC]); \ + ranges[0].size = (map)->l_info[DT_##RELOC##SZ]->d_un.d_val; \ + if (map->l_info[VERSYMIDX (DT_##RELOC##COUNT)] != NULL) \ + ranges[0].nrelative \ + = map->l_info[VERSYMIDX (DT_##RELOC##COUNT)]->d_un.d_val; \ + } \ + if ((map)->l_info[DT_PLTREL] \ + && (!test_rel || (map)->l_info[DT_PLTREL]->d_un.d_val == DT_##RELOC)) \ + { \ + ElfW(Addr) start = D_PTR ((map), l_info[DT_JMPREL]); \ + ElfW(Addr) size = (map)->l_info[DT_PLTRELSZ]->d_un.d_val; \ + \ + if (ranges[0].start + ranges[0].size == (start + size)) \ + ranges[0].size -= size; \ + if (ELF_DURING_STARTUP \ + || (!(do_lazy) \ + && (ranges[0].start + ranges[0].size) == start)) \ + { \ + /* Combine processing the sections. */ \ + ranges[0].size += size; \ + } \ + else \ + { \ + ranges[1].start = start; \ + ranges[1].size = size; \ + ranges[1].lazy = (do_lazy); \ + } \ + } \ + \ + if (ELF_DURING_STARTUP) \ + elf_dynamic_do_##reloc ((map), ranges[0].start, ranges[0].size, \ + ranges[0].nrelative, 0, skip_ifunc); \ + else \ + { \ + int ranges_index; \ + for (ranges_index = 0; ranges_index < 2; ++ranges_index) \ + elf_dynamic_do_##reloc ((map), \ + ranges[ranges_index].start, \ + ranges[ranges_index].size, \ + ranges[ranges_index].nrelative, \ + ranges[ranges_index].lazy, \ + skip_ifunc); \ + } \ + } while (0) + +# if ELF_MACHINE_NO_REL || ELF_MACHINE_NO_RELA +# define _ELF_CHECK_REL 0 +# else +# define _ELF_CHECK_REL 1 +# endif + +# if ! ELF_MACHINE_NO_REL +# include "do-rel.h" +# define ELF_DYNAMIC_DO_REL(map, lazy, skip_ifunc) \ + _ELF_DYNAMIC_DO_RELOC (REL, Rel, map, lazy, skip_ifunc, _ELF_CHECK_REL) +# else +# define ELF_DYNAMIC_DO_REL(map, lazy, skip_ifunc) /* Nothing to do. */ +# endif + +# if ! ELF_MACHINE_NO_RELA +# define DO_RELA +# include "do-rel.h" +# define ELF_DYNAMIC_DO_RELA(map, lazy, skip_ifunc) \ + _ELF_DYNAMIC_DO_RELOC (RELA, Rela, map, lazy, skip_ifunc, _ELF_CHECK_REL) +# else +# define ELF_DYNAMIC_DO_RELA(map, lazy, skip_ifunc) /* Nothing to do. */ +# endif + +/* This can't just be an inline function because GCC is too dumb + to inline functions containing inlines themselves. */ +# define ELF_DYNAMIC_RELOCATE(map, lazy, consider_profile, skip_ifunc) \ + do { \ + int edr_lazy = elf_machine_runtime_setup ((map), (lazy), \ + (consider_profile)); \ + ELF_DYNAMIC_DO_REL ((map), edr_lazy, skip_ifunc); \ + ELF_DYNAMIC_DO_RELA ((map), edr_lazy, skip_ifunc); \ + } while (0) + +#endif |