sysdeps/unix/sysv/linux/mlock2.c

   1 /* Wrapper for the mlock2 system call with fallback to mlock.
   2    Copyright (C) 2017-2024 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/mman.h>
  19 #include <errno.h>
  20 #include <sysdep.h>
  21
  22 int
  23 mlock2 (const void *addr, size_t length, unsigned int flags)
  24 {
  25 #ifdef __ASSUME_MLOCK2
  26   return INLINE_SYSCALL_CALL (mlock2, addr, length, flags);
  27 #else
  28   if (flags == 0)
  29     return INLINE_SYSCALL_CALL (mlock, addr, length);
  30   int ret = INLINE_SYSCALL_CALL (mlock2, addr, length, flags);
  31   if (ret == 0 || errno != ENOSYS)
  32     return ret;
  33   /* Treat the missing system call as an invalid (non-zero) flag
  34      argument.  */
  35   __set_errno (EINVAL);
  36   return -1;
  37 #endif /* __ASSUME_MLOCK2 */
  38 }