| /* Inline functions for dynamic linking. |
| Copyright (C) 1995-2018 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/>. */ |
| |
| #ifndef NESTING |
| #define auto static |
| #endif |
| |
| /* 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 _dl_try_allocate_static_tls (struct link_map *map) attribute_hidden; |
| |
| #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 |
| #ifndef NESTING |
| , struct link_map *boot_map |
| #endif |
| ); |
| 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 |
| |
| # if defined RTLD_BOOTSTRAP || defined STATIC_PIE_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. */ |
| |
| #ifndef NESTING |
| # define _ELF_DYNAMIC_DO_RELOC(RELOC, reloc, map, do_lazy, skip_ifunc, test_rel, boot_map) \ |
| 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 } }; \ |
| \ |
| /* With DT_RELR, DT_RELA/DT_REL can have zero value. */ \ |
| if ((map)->l_info[DT_##RELOC] != NULL \ |
| && (map)->l_info[DT_##RELOC]->d_un.d_ptr != 0) \ |
| { \ |
| 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 == 0) \ |
| ranges[0].start = start; \ |
| 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, boot_map); \ |
| 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, boot_map); \ |
| } \ |
| } while (0) |
| #else /* NESTING */ |
| # 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) |
| #endif /* NESTING */ |
| |
| # if ELF_MACHINE_NO_REL || ELF_MACHINE_NO_RELA |
| # define _ELF_CHECK_REL 0 |
| # else |
| # define _ELF_CHECK_REL 1 |
| # endif |
| |
| #ifndef NESTING |
| # if ! ELF_MACHINE_NO_REL |
| # include "do-rel.h" |
| # define ELF_DYNAMIC_DO_REL(map, lazy, skip_ifunc, boot_map) \ |
| _ELF_DYNAMIC_DO_RELOC (REL, Rel, map, lazy, skip_ifunc, _ELF_CHECK_REL, boot_map) |
| # else |
| # define ELF_DYNAMIC_DO_REL(map, lazy, skip_ifunc, boot_map) /* 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, boot_map) \ |
| _ELF_DYNAMIC_DO_RELOC (RELA, Rela, map, lazy, skip_ifunc, _ELF_CHECK_REL, boot_map) |
| # else |
| # define ELF_DYNAMIC_DO_RELA(map, lazy, skip_ifunc, boot_map) /* Nothing to do. */ |
| # endif |
| |
| /* Google-local: b/208156916. To not bump DT_NUM, use DT_VERSYM+1 for DT_RELR |
| and DT_VERSYM+2 for DT_RELRSZ. */ |
| # define ELF_DYNAMIC_DO_RELR(map) \ |
| do { \ |
| ElfW(Addr) l_addr = (map)->l_addr, *where = 0; \ |
| const ElfW(Relr) *r, *end; \ |
| if (!(map)->l_info[VERSYMIDX (DT_VERSYM + 1)]) \ |
| break; \ |
| r = (const ElfW(Relr) *)D_PTR((map), l_info[VERSYMIDX (DT_VERSYM + 1)]); \ |
| end = (const ElfW(Relr) *)((const char *)r + \ |
| (map)->l_info[VERSYMIDX (DT_VERSYM + 2)]->d_un.d_val); \ |
| for (; r < end; r++) \ |
| { \ |
| ElfW(Relr) entry = *r; \ |
| if ((entry & 1) == 0) \ |
| { \ |
| where = (ElfW(Addr) *)(l_addr + entry); \ |
| *where++ += l_addr; \ |
| } \ |
| else \ |
| { \ |
| for (long i = 0; (entry >>= 1) != 0; i++) \ |
| if ((entry & 1) != 0) \ |
| where[i] += l_addr; \ |
| where += CHAR_BIT * sizeof(ElfW(Relr)) - 1; \ |
| } \ |
| } \ |
| } while (0); |
| |
| /* This can't just be an inline function because GCC is too dumb |
| to inline functions containing inlines themselves. */ |
| # ifdef RTLD_BOOTSTRAP |
| # define DO_RTLD_BOOTSTRAP 1 |
| # else |
| # define DO_RTLD_BOOTSTRAP 0 |
| # endif |
| # define ELF_DYNAMIC_RELOCATE(map, lazy, consider_profile, skip_ifunc, boot_map) \ |
| do { \ |
| int edr_lazy = elf_machine_runtime_setup ((map), (lazy), \ |
| (consider_profile)); \ |
| if (((map) != &GL(dl_rtld_map) || DO_RTLD_BOOTSTRAP)) \ |
| ELF_DYNAMIC_DO_RELR (map); \ |
| ELF_DYNAMIC_DO_REL ((map), edr_lazy, skip_ifunc, boot_map); \ |
| ELF_DYNAMIC_DO_RELA ((map), edr_lazy, skip_ifunc, boot_map); \ |
| } while (0) |
| #else /* NESTING */ |
| # 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 /* NESTING */ |
| |
| #endif |
