sysdeps/unix/sysv/linux/dl-vdso-setup.c

   1 /* Data for vDSO support.  Linux version.
   2    Copyright (C) 2020-2024 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 keyword 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
  75 /* RISC-V specific ones.  */
  76 # ifdef HAVE_RISCV_HWPROBE
  77 PROCINFO_CLASS int (*_dl_vdso_riscv_hwprobe)(void *,
  78                                              size_t,
  79                                              size_t,
  80                                              unsigned long *,
  81                                              unsigned int) RELRO;
  82 # endif
  83
  84 #endif
  85
  86 #undef RELRO
  87 #undef PROCINFO_DECL
  88 #undef PROCINFO_CLASS