1  /* Memory allocation next to an unmapped page.
       2     Copyright (C) 2017-2023 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 SUPPORT_NEXT_TO_FAULT_H
      20  #define SUPPORT_NEXT_TO_FAULT_H
      21  
      22  #include <sys/cdefs.h>
      23  #include <sys/types.h>
      24  
      25  __BEGIN_DECLS
      26  
      27  /* The memory region created by next_to_fault_allocate.  */
      28  struct support_next_to_fault
      29  {
      30    /* The user data.  */
      31    char *buffer;
      32    size_t length;
      33  
      34    /* The entire allocated region.  */
      35    void *region_start;
      36    size_t region_size;
      37  };
      38  
      39  /* Allocate a buffer of SIZE bytes just before a page which is mapped
      40     with PROT_NONE (so that overrunning the buffer will cause a
      41     fault).  */
      42  struct support_next_to_fault support_next_to_fault_allocate (size_t size);
      43  
      44  /* Deallocate the memory region allocated by
      45     next_to_fault_allocate.  */
      46  void support_next_to_fault_free (struct support_next_to_fault *);
      47  
      48  #endif /* SUPPORT_NEXT_TO_FAULT_H */