service_runtime/sel_mem.h

   1 /*
   2  * Copyright 2008, Google Inc.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions are
   7  * met:
   8  *
   9  *     * Redistributions of source code must retain the above copyright
  10  * notice, this list of conditions and the following disclaimer.
  11  *     * Redistributions in binary form must reproduce the above
  12  * copyright notice, this list of conditions and the following disclaimer
  13  * in the documentation and/or other materials provided with the
  14  * distribution.
  15  *     * Neither the name of Google Inc. nor the names of its
  16  * contributors may be used to endorse or promote products derived from
  17  * this software without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  20  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  21  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  22  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  23  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  24  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  25  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  26  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  27  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  28  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  29  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  30  */
  31
  32 /*
  33  * NaCl Simple/secure ELF loader (NaCl SEL) memory map.
  34  */
  35
  36 #ifndef NATIVE_CLIENT_SERVICE_RUNTIME_SEL_MEM_H_
  37 #define NATIVE_CLIENT_SERVICE_RUNTIME_SEL_MEM_H_
  38
  39 #include "native_client/include/portability.h"
  40 #include "native_client/include/nacl_base.h"
  41 #include "native_client/service_runtime/nacl_memory_object.h"
  42
  43 EXTERN_C_BEGIN
  44
  45 /*
  46  * Interface is based on setting properties and query properties by
  47  * page numbers (addr >> NACL_PAGESHIFT) and the number of pages
  48  * affected (for setting properties).
  49  *
  50  * Initially, the address space is empty, with all memory
  51  * inaccessible.  As the program is loaded, pages are marked
  52  * accessible -- text pages are non-writable, data and stack are
  53  * writable.  At runtime, shared memory buffers are allocated by
  54  * looking at the first memory hole that fits, starting down from the
  55  * stack.
  56  *
  57  * The simple data structure that we use is a sorted array of valid
  58  * memory regions.
  59  */
  60
  61 struct NaClVmmapEntry {
  62   uintptr_t             page_num;   /* base virtual address >> NACL_PAGESHIFT */
  63   size_t                npages;     /* number of pages */
  64   int                   prot;       /* mprotect attribute */
  65   struct NaClMemObj     *nmop;      /* how to get memory for move/remap */
  66   int                   removed;    /* flag set in NaClVmmapUpdate */
  67 };
  68
  69 struct NaClVmmap {
  70   struct NaClVmmapEntry **vmentry;       /* must not overlap */
  71   size_t                nvalid, size;
  72   int                   is_sorted;
  73 };
  74
  75 void NaClVmmapDebug(struct NaClVmmap  *self,
  76                     char              *msg);
  77
  78 /*
  79  * iterators methods are final for now.
  80  */
  81 struct NaClVmmapIter {
  82   struct NaClVmmap      *vmmap;
  83   unsigned int          entry_ix;
  84 };
  85
  86 int                   NaClVmmapIterAtEnd(struct NaClVmmapIter *nvip);
  87 struct NaClVmmapEntry *NaClVmmapIterStar(struct NaClVmmapIter *nvip);
  88 void                  NaClVmmapIterIncr(struct NaClVmmapIter *nvip);
  89 void                  NaClVmmapIterErase(struct NaClVmmapIter *nvip);
  90
  91 int   NaClVmmapCtor(struct NaClVmmap  *self);
  92
  93 void  NaClVmmapDtor(struct NaClVmmap  *self);
  94
  95 int   NaClVmmapAdd(struct NaClVmmap   *self,
  96                    uintptr_t          page_num,
  97                    size_t             npages,
  98                    int                prot,
  99                    struct NaClMemObj  *nmop);
 100
 101 void NaClVmmapUpdate(struct NaClVmmap   *self,
 102                      uintptr_t          page_num,
 103                      size_t             npages,
 104                      int                prot,
 105                      struct NaClMemObj  *nmop,
 106                      int                remove);
 107
 108 /*
 109  * NaClVmmapFindPage and NaClVmmapFindPageIter only works if pnum is
 110  * in the NaClVmmap.  If not, NULL and an AtEnd iterator is returned.
 111  */
 112 struct NaClVmmapEntry const *NaClVmmapFindPage(struct NaClVmmap *self,
 113                                                uintptr_t        pnum);
 114
 115 struct NaClVmmapIter *NaClVmmapFindPageIter(struct NaClVmmap      *self,
 116                                             uintptr_t             pnum,
 117                                             struct NaClVmmapIter  *space);
 118
 119 /*
 120  * Visitor pattern, call fn on every entry.
 121  */
 122 void  NaClVmmapVisit(struct NaClVmmap   *self,
 123                      void               (*fn)(void                  *state,
 124                                               struct NaClVmmapEntry *entry),
 125                      void               *state);
 126
 127 /*
 128  * Returns page number starting at which there is a hole of at least
 129  * num_pages in size.  Linear search from high addresses on down.
 130  */
 131 uintptr_t NaClVmmapFindSpace(struct NaClVmmap *self,
 132                              size_t           num_pages);
 133
 134 /*
 135  * Just lke NaClVmmapFindSpace, except usage is intended for
 136  * NaClHostDescMap, so the starting address of the region found must
 137  * be NACL_MAP_PAGESIZE aligned.
 138  */
 139 uintptr_t NaClVmmapFindMapSpace(struct NaClVmmap *self,
 140                                 size_t           num_pages);
 141
 142 uintptr_t NaClVmmapFindMapSpaceAboveHint(struct NaClVmmap *self,
 143                                          uintptr_t        uaddr,
 144                                          size_t           num_pages);
 145
 146 void NaClVmmapMakeSorted(struct NaClVmmap  *self);
 147
 148 EXTERN_C_END
 149
 150 #endif