config/gen/platform/openbsd/memexec.c

   1 /*
   2  * $Id$
   3  * Copyright (C) 2004-2010, Parrot Foundation.
   4  */
   5
   6 /*
   7
   8 =head1 NAME
   9
  10 memexec.c
  11
  12 =head1 DESCRIPTION
  13
  14 Memory protection functions.
  15
  16 =head2 Functions
  17
  18 =over 4
  19
  20 =cut
  21
  22 */
  23
  24 #ifdef PARROT_HAS_EXEC_PROTECT
  25 /*
  26
  27 =item C<void * mem_alloc_executable(size_t size)>
  28
  29 Allocate executable memory
  30 Round up to page size because the whole page will be marked as executable
  31 malloc() under OpenBSD page-aligns allocations >= page size
  32
  33 =cut
  34
  35 */
  36
  37 void *
  38 mem_alloc_executable(size_t size)
  39 {
  40     void *p;
  41     size_t pagesize = sysconf(_SC_PAGESIZE);
  42     size = (size + pagesize - 1) & ~(pagesize-1);
  43     p = malloc(size);
  44     if (p != NULL) {
  45         mprotect(p, size, PROT_READ|PROT_WRITE|PROT_EXEC);
  46     }
  47     return p;
  48 }
  49
  50 /*
  51
  52 =item C<void mem_free_executable(void *p, size_t size)>
  53
  54 Free a buffer allocated with mem_alloc_executable().
  55
  56 =cut
  57
  58 */
  59
  60 void
  61 mem_free_executable(void *p, size_t size)
  62 {
  63     free(p);
  64 }
  65
  66 /*
  67
  68 =item C<void * mem_realloc_executable(void* oldp, size_t oldsize, size_t
  69 newsize)>
  70
  71 Reallocate executable memory
  72 Round up to page size because the whole page will be marked as executable
  73
  74 =cut
  75
  76 */
  77
  78 void *
  79 mem_realloc_executable(void* oldp, size_t oldsize, size_t newsize)
  80 {
  81     size_t pagesize = sysconf(_SC_PAGESIZE);
  82     size_t roundup = (newsize + pagesize - 1) & ~(pagesize-1);
  83     void *newp = realloc(oldp, roundup);
  84     if (newp != NULL) {
  85         mprotect(newp, roundup, PROT_READ|PROT_WRITE|PROT_EXEC);
  86     }
  87     return newp;
  88 }
  89 #endif
  90
  91 /*
  92
  93 =back
  94
  95 =cut
  96
  97 */
  98
  99 /*
 100  * Local variables:
 101  *   c-file-style: "parrot"
 102  * End:
 103  * vim: expandtab shiftwidth=4:
 104  */