1  /* Wrapper for the mlock2 system call with fallback to mlock.
       2     Copyright (C) 2017-2023 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  }