sysdeps/unix/sysv/linux/x86_64/64/mmap_internal.h

   1 /* Linux mmap system call.  x86-64 version.
   2    Copyright (C) 2015-2024 Free Software Foundation, Inc.
   3
   4    This file is part of the GNU C Library.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public License as
   8    published by the Free Software Foundation; either version 2.1 of the
   9    License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, see
  18    <https://www.gnu.org/licenses/>.  */
  19
  20 #ifndef MMAP_X86_64_INTERNAL_H
  21 #define MMAP_X86_64_INTERNAL_H
  22
  23 #include <ldsodefs.h>
  24
  25 /* If the Prefer_MAP_32BIT_EXEC bit is set, try to map executable or
  26     denywrite pages with MAP_32BIT first.  */
  27 #define MMAP_PREPARE(addr, len, prot, flags, fd, offset)                \
  28   if ((addr) == NULL                                                    \
  29       && (((prot) & PROT_EXEC) != 0                                     \
  30           || ((flags) & MAP_DENYWRITE) != 0)                            \
  31       && HAS_ARCH_FEATURE (Prefer_MAP_32BIT_EXEC))                      \
  32     {                                                                   \
  33       void *ret = (void*) INLINE_SYSCALL_CALL (mmap, (addr), (len),     \
  34                                               (prot),                   \
  35                                               (flags) | MAP_32BIT,      \
  36                                               (fd), (offset));          \
  37       if (ret != MAP_FAILED)                                            \
  38         return ret;                                                     \
  39     }
  40
  41 #include_next <mmap_internal.h>
  42
  43 #endif