1 /* Support for GNU properties. AArch64 version.
2 Copyright (C) 2018-2022 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_PROP_H
20 #define _DL_PROP_H
21
22 extern void _dl_bti_protect (struct link_map *, int) attribute_hidden;
23
24 extern void _dl_bti_check (struct link_map *, const char *)
25 attribute_hidden;
26
27 static inline void __attribute__ ((always_inline))
_rtld_main_check(struct link_map * m,const char * program)28 _rtld_main_check (struct link_map *m, const char *program)
29 {
30 _dl_bti_check (m, program);
31 }
32
33 static inline void __attribute__ ((always_inline))
_dl_open_check(struct link_map * m)34 _dl_open_check (struct link_map *m)
35 {
36 _dl_bti_check (m, NULL);
37 }
38
39 static inline void __attribute__ ((always_inline))
_dl_process_pt_note(struct link_map * l,int fd,const ElfW (Phdr)* ph)40 _dl_process_pt_note (struct link_map *l, int fd, const ElfW(Phdr) *ph)
41 {
42 }
43
44 static inline int
_dl_process_gnu_property(struct link_map * l,int fd,uint32_t type,uint32_t datasz,void * data)45 _dl_process_gnu_property (struct link_map *l, int fd, uint32_t type,
46 uint32_t datasz, void *data)
47 {
48 if (!GLRO(dl_aarch64_cpu_features).bti)
49 /* Skip note processing. */
50 return 0;
51
52 if (type == GNU_PROPERTY_AARCH64_FEATURE_1_AND)
53 {
54 /* Stop if the property note is ill-formed. */
55 if (datasz != 4)
56 return 0;
57
58 unsigned int feature_1 = *(unsigned int *) data;
59 if (feature_1 & GNU_PROPERTY_AARCH64_FEATURE_1_BTI)
60 _dl_bti_protect (l, fd);
61
62 /* Stop if we processed the property note. */
63 return 0;
64 }
65 /* Continue. */
66 return 1;
67 }
68
69 #endif /* _DL_PROP_H */
70