sysdeps/unix/sysv/linux/x86/dl-cet.h

   1 /* Linux/x86 CET initializers function.
   2    Copyright (C) 2018-2019 Free Software Foundation, Inc.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <https://www.gnu.org/licenses/>.  */
  17
  18 #include <sys/prctl.h>
  19 #include <asm/prctl.h>
  20
  21 static inline int __attribute__ ((always_inline))
  22 dl_cet_allocate_legacy_bitmap (unsigned long *legacy_bitmap)
  23 {
  24   /* Allocate legacy bitmap.  */
  25   INTERNAL_SYSCALL_DECL (err);
  26 #ifdef __LP64__
  27   return (int) INTERNAL_SYSCALL (arch_prctl, err, 2,
  28                                  ARCH_CET_LEGACY_BITMAP, legacy_bitmap);
  29 #else
  30   unsigned long long legacy_bitmap_u64[2];
  31   int res = INTERNAL_SYSCALL (arch_prctl, err, 2,
  32                               ARCH_CET_LEGACY_BITMAP, legacy_bitmap_u64);
  33   if (res == 0)
  34     {
  35       legacy_bitmap[0] = legacy_bitmap_u64[0];
  36       legacy_bitmap[1] = legacy_bitmap_u64[1];
  37     }
  38   return res;
  39 #endif
  40 }
  41
  42 static inline int __attribute__ ((always_inline))
  43 dl_cet_disable_cet (unsigned int cet_feature)
  44 {
  45   INTERNAL_SYSCALL_DECL (err);
  46   return (int) INTERNAL_SYSCALL (arch_prctl, err, 2, ARCH_CET_DISABLE,
  47                                  cet_feature);
  48 }
  49
  50 static inline int __attribute__ ((always_inline))
  51 dl_cet_lock_cet (void)
  52 {
  53   INTERNAL_SYSCALL_DECL (err);
  54   return (int) INTERNAL_SYSCALL (arch_prctl, err, 2, ARCH_CET_LOCK, 0);
  55 }