1 /* Data for vDSO support.  Linux version.
2    Copyright (C) 2020-2021 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 /* This file is included in three different modes for both static (libc.a)
20    and shared (rtld) modes:
21 
22    1. PROCINFO_DECL is defined, meaning we are only interested in
23       declarations.  For static it requires use the extern keywork along with
24       the attribute_relro while for shared it will be embedded in the
25       rtld_global_ro.
26 
27    2. PROCINFO_DECL and SHARED are not defined.  Nothing to do, the default
28       zero initializion is suffice.
29 
30    3. PROCINFO_DECL is not defined while SHARED is.  Similar to 2., the zero
31       initialization of rtld_global_ro is suffice.  */
32 
33 #ifndef PROCINFO_CLASS
34 # define PROCINFO_CLASS
35 #endif
36 
37 #ifndef SHARED
38 # define RELRO attribute_relro
39 #else
40 # define RELRO
41 #endif
42 
43 #if defined PROCINFO_DECL || !defined SHARED
44 # ifdef HAVE_CLOCK_GETTIME_VSYSCALL
45 PROCINFO_CLASS int (*_dl_vdso_clock_gettime) (clockid_t,
46 					      struct timespec *) RELRO;
47 #endif
48 # ifdef HAVE_CLOCK_GETTIME64_VSYSCALL
49 PROCINFO_CLASS int (*_dl_vdso_clock_gettime64) (clockid_t,
50 						struct __timespec64 *) RELRO;
51 #endif
52 # ifdef HAVE_GETTIMEOFDAY_VSYSCALL
53 PROCINFO_CLASS int (*_dl_vdso_gettimeofday) (struct timeval *, void *) RELRO;
54 #endif
55 # ifdef HAVE_TIME_VSYSCALL
56 PROCINFO_CLASS time_t (*_dl_vdso_time) (time_t *) RELRO;
57 # endif
58 # ifdef HAVE_GETCPU_VSYSCALL
59 PROCINFO_CLASS int (*_dl_vdso_getcpu) (unsigned *, unsigned *, void *) RELRO;
60 # endif
61 # ifdef HAVE_CLOCK_GETRES_VSYSCALL
62 PROCINFO_CLASS int (*_dl_vdso_clock_getres) (clockid_t,
63 					     struct timespec *) RELRO;
64 # endif
65 # ifdef HAVE_CLOCK_GETRES64_VSYSCALL
66 PROCINFO_CLASS int (*_dl_vdso_clock_getres_time64) (clockid_t,
67 						    struct __timespec64 *) RELRO;
68 # endif
69 
70 /* PowerPC specific ones.  */
71 # ifdef HAVE_GET_TBFREQ
72 PROCINFO_CLASS uint64_t (*_dl_vdso_get_tbfreq)(void) RELRO;
73 # endif
74 #endif
75 
76 #undef RELRO
77 #undef PROCINFO_DECL
78 #undef PROCINFO_CLASS
79