sysdeps/aarch64/dl-prop.h

   1 /* Support for GNU properties.  AArch64 version.
   2    Copyright (C) 2018-2021 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 #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))
  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))
  34 _dl_open_check (struct link_map *m)
  35 {
  36   _dl_bti_check (m, NULL);
  37 }
  38
  39 static inline void __attribute__ ((always_inline))
  40 _dl_process_pt_note (struct link_map *l, int fd, const ElfW(Phdr) *ph)
  41 {
  42 }
  43
  44 static inline int
  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 */