1/* Support for STV_PROTECTED visibility. Generic version.
2 Copyright (C) 2021-2022 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#ifndef _DL_PROTECTED_H
20#define _DL_PROTECTED_H
21
22static inline void __attribute__ ((always_inline))
23_dl_check_protected_symbol (const char *undef_name,
24 const struct link_map *undef_map,
25 const ElfW(Sym) *ref,
26 const struct link_map *map,
27 int type_class)
28{
29 if (undef_map == NULL || undef_map->l_type != lt_executable)
30 return;
31
32 if (type_class & ELF_RTYPE_CLASS_COPY)
33 /* Disallow copy relocations in executable against protected
34 data symbols in a shared object which needs indirect external
35 access. */
36 _dl_error_printf ("warning: copy relocation against non-copyable "
37 "protected symbol `%s' in `%s'\n",
38 undef_name, map->l_name);
39 else if ((type_class & ELF_RTYPE_CLASS_PLT) && ref->st_value != 0
40 && ref->st_shndx == SHN_UNDEF)
41 /* Disallow non-zero symbol values of undefined symbols in
42 executable, which are used as the function pointer, against
43 protected function symbols in a shared object with indirect
44 external access. */
45 _dl_error_printf (
46 "warning: direct reference to "
47 "protected function `%s' in `%s' may break pointer equality\n",
48 undef_name, map->l_name);
49 else
50 return;
51
52 if (map->l_1_needed & GNU_PROPERTY_1_NEEDED_INDIRECT_EXTERN_ACCESS)
53 _dl_signal_error (
54 0, map->l_name, undef_name,
55 N_ ("error due to GNU_PROPERTY_1_NEEDED_INDIRECT_EXTERN_ACCESS"));
56}
57
58#endif /* _DL_PROTECTED_H */
59