1 /* Configuration of lookup functions. 2 Copyright (C) 2000-2022 Free Software Foundation, Inc. 3 This file is part of the GNU C Library. 4 5 The GNU C Library is free software; you can redistribute it and/or 6 modify it under the terms of the GNU Lesser General Public 7 License as published by the Free Software Foundation; either 8 version 2.1 of the License, or (at your option) any later version. 9 10 The GNU C Library is distributed in the hope that it will be useful, 11 but WITHOUT ANY WARRANTY; without even the implied warranty of 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 13 Lesser General Public License for more details. 14 15 You should have received a copy of the GNU Lesser General Public 16 License along with the GNU C Library. If not, see 17 <https://www.gnu.org/licenses/>. */ 18 19 #define ELF_FUNCTION_PTR_IS_SPECIAL 20 #define DL_UNMAP_IS_SPECIAL 21 22 #include <dl-fptr.h> 23 24 /* Forward declaration. */ 25 struct link_map; 26 27 void *_dl_symbol_address (struct link_map *map, const ElfW(Sym) *ref); 28 rtld_hidden_proto (_dl_symbol_address) 29 30 #define DL_SYMBOL_ADDRESS(map, ref) _dl_symbol_address(map, ref) 31 32 Elf32_Addr _dl_lookup_address (const void *address); 33 rtld_hidden_proto (_dl_lookup_address) 34 35 #define DL_LOOKUP_ADDRESS(addr) _dl_lookup_address ((const void *) addr) 36 37 void attribute_hidden _dl_unmap (struct link_map *map); 38 39 #define DL_UNMAP(map) _dl_unmap (map) 40 41 #define DL_DT_FUNCTION_ADDRESS(map, start, attr, addr) \ 42 attr volatile unsigned int fptr[2]; \ 43 /* The test for "start & 2" below is to accommodate old binaries which \ 44 violated the ELF ABI by pointing DT_INIT and DT_FINI at a function \ 45 descriptor. */ \ 46 if ((ElfW(Addr)) (start) & 2) \ 47 addr = (ElfW(Addr)) start; \ 48 else \ 49 { \ 50 fptr[0] = (unsigned int) (start); \ 51 fptr[1] = (map)->l_info[DT_PLTGOT]->d_un.d_ptr; \ 52 /* Set bit 30 to indicate to $$dyncall that this is a PLABEL. */ \ 53 addr = (ElfW(Addr))((unsigned int)fptr | 2); \ 54 } \ 55 56 #define DL_CALL_DT_INIT(map, start, argc, argv, env) \ 57 { \ 58 ElfW(Addr) addr; \ 59 DL_DT_FUNCTION_ADDRESS(map, start, , addr) \ 60 dl_init_t init = (dl_init_t) addr; \ 61 init (argc, argv, env); \ 62 } 63 64 #define DL_CALL_DT_FINI(map, start) \ 65 { \ 66 ElfW(Addr) addr; \ 67 DL_DT_FUNCTION_ADDRESS(map, start, , addr) \ 68 fini_t fini = (fini_t) addr; \ 69 fini (); \ 70 } 71 72 /* The type of the return value of fixup/profile_fixup */ 73 #define DL_FIXUP_VALUE_TYPE struct fdesc 74 75 /* Construct a fixup value from the address and linkmap */ 76 #define DL_FIXUP_MAKE_VALUE(map, addr) \ 77 (map) ? ((struct fdesc) { (addr), (map)->l_info[DT_PLTGOT]->d_un.d_ptr }) \ 78 : ((struct fdesc) { 0, 0 }) 79 80 /* Extract the code address from a fixup value */ 81 #define DL_FIXUP_VALUE_CODE_ADDR(value) ((value).ip) 82 #define DL_FIXUP_VALUE_ADDR(value) ((uintptr_t) &(value)) 83 /* Clear the plabel bit to get the actual address of the descriptor. */ 84 #define DL_FIXUP_ADDR_VALUE(addr) \ 85 (*(DL_FIXUP_VALUE_TYPE *) ((uintptr_t) (addr) & ~2)) 86 #define DL_FIXUP_BINDNOW_ADDR_VALUE(addr) (addr) 87 #define DL_FIXUP_BINDNOW_RELOC(value, new_value, st_value) \ 88 *(value) = *(DL_FIXUP_VALUE_TYPE *) ((uintptr_t) (new_value) & ~2) 89