1 /* Special .init and .fini section support. 2 Copyright (C) 1997-2022 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 In addition to the permissions in the GNU Lesser General Public 11 License, the Free Software Foundation gives you unlimited 12 permission to link the compiled version of this file with other 13 programs, and to distribute those programs without any restriction 14 coming from the use of this file. (The Lesser General Public 15 License restrictions do apply in other respects; for example, they 16 cover modification of the file, and distribution when not linked 17 into another program.) 18 19 The GNU C Library is distributed in the hope that it will be useful, 20 but WITHOUT ANY WARRANTY; without even the implied warranty of 21 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 22 Lesser General Public License for more details. 23 24 You should have received a copy of the GNU Lesser General Public 25 License along with the GNU C Library; if not, see 26 <https://www.gnu.org/licenses/>. */ 27 28 /* Define an ELF note identifying the operating-system ABI that the 29 executable was created for. The ELF note information identifies a 30 particular OS or coordinated development effort within which the 31 ELF header's e_machine value plus (for dynamically linked programs) 32 the PT_INTERP dynamic linker name and DT_NEEDED shared library 33 names fully identify the runtime environment required by an 34 executable. 35 36 The general format of ELF notes is as follows. 37 Offsets and lengths are bytes or (parenthetical references) to the 38 values in other fields. 39 40 offset length contents 41 0 4 length of name 42 4 4 length of data 43 8 4 note type 44 12 (0) vendor name 45 - null-terminated ASCII string, padded to 4-byte alignment 46 12+(0) (4) note data, 47 48 The GNU project and cooperating development efforts (including the 49 Linux community) use note type 1 and a vendor name string of "GNU" 50 for a note descriptor that indicates ABI requirements. The note data 51 is four 32-bit words. The first of these is an operating system 52 number (0=Linux, 1=Hurd, 2=Solaris, ...) and the remaining three 53 identify the earliest release of that OS that supports this ABI. 54 See abi-tags (top level) for details. */ 55 56 #include <link.h> 57 #include <stdint.h> 58 #include <config.h> 59 #include <abi-tag.h> /* OS-specific ABI tag value */ 60 61 /* The linker (GNU ld 2.8 and later) recognizes an allocated section whose 62 name begins with `.note' and creates a PT_NOTE program header entry 63 pointing at it. */ 64 65 __attribute__ ((used, aligned (4), section (".note.ABI-tag"))) 66 static const struct 67 { 68 ElfW(Nhdr) nhdr; 69 char name[4]; 70 int32_t desc[4]; 71 } __abi_tag = { 72 { .n_namesz = sizeof __abi_tag.name, 73 .n_descsz = sizeof __abi_tag.desc, 74 .n_type = 1 }, 75 "GNU", 76 { __ABI_TAG_OS, __ABI_TAG_VERSION } 77 }; 78