support/next_to_fault.h

   1 /* Memory allocation next to an unmapped page.
   2    Copyright (C) 2017-2022 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 */