cdsa/cdsa_utilities/cssmalloc.cpp

   1 /*
   2  * Copyright (c) 2000-2001 Apple Computer, Inc. All Rights Reserved.
   3  *
   4  * The contents of this file constitute Original Code as defined in and are
   5  * subject to the Apple Public Source License Version 1.2 (the 'License').
   6  * You may not use this file except in compliance with the License. Please obtain
   7  * a copy of the License at http://www.apple.com/publicsource and read it before
   8  * using this file.
   9  *
  10  * This Original Code and all software distributed under the License are
  11  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESS
  12  * OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, INCLUDING WITHOUT
  13  * LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
  14  * PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. Please see the License for the
  15  * specific language governing rights and limitations under the License.
  16  */
  17
  18
  19 //
  20 // cssmalloc - memory allocation in the CDSA world.
  21 //
  22 // Don't eat heavily before inspecting this code.
  23 //
  24 #include <Security/cssmalloc.h>
  25 #include <Security/memutils.h>
  26 #include <Security/globalizer.h>
  27 #include <Security/trackingallocator.h>
  28 #include <stdlib.h>
  29 #include <errno.h>
  30
  31 using LowLevelMemoryUtilities::alignof;
  32 using LowLevelMemoryUtilities::increment;
  33 using LowLevelMemoryUtilities::alignUp;
  34
  35 extern "C" size_t malloc_size(void *);
  36
  37
  38 //
  39 // Features of the CssmAllocator root class
  40 //
  41 bool CssmAllocator::operator == (const CssmAllocator &alloc) const throw()
  42 {
  43         return this == &alloc;
  44 }
  45
  46 CssmAllocator::~CssmAllocator()
  47 {
  48 }
  49
  50
  51 //
  52 // Standard CssmAllocator variants.
  53 // Note that all calls to CssmAllocator::standard(xxx) with the same xxx argument
  54 // must produce compatible allocators (i.e. they must be work on a common memory
  55 // pool). This is trivially achieved here by using singletons.
  56 //
  57 struct DefaultCssmAllocator : public CssmAllocator {
  58         void *malloc(size_t size) throw(std::bad_alloc);
  59         void free(void *addr) throw();
  60         void *realloc(void *addr, size_t size) throw(std::bad_alloc);
  61 };
  62
  63 struct SensitiveCssmAllocator : public DefaultCssmAllocator {
  64     void free(void *addr) throw();
  65     void *realloc(void *addr, size_t size) throw(std::bad_alloc);
  66 };
  67
  68 struct DefaultAllocators {
  69     DefaultCssmAllocator standard;
  70     SensitiveCssmAllocator sensitive;
  71 };
  72
  73 static ModuleNexus<DefaultAllocators> defaultAllocators;
  74
  75
  76 CssmAllocator &CssmAllocator::standard(uint32 request)
  77 {
  78     switch (request) {
  79     case normal:
  80         return defaultAllocators().standard;
  81     case sensitive:
  82         return defaultAllocators().sensitive;
  83     default:
  84         CssmError::throwMe(CSSM_ERRCODE_MEMORY_ERROR);
  85     }
  86 }
  87
  88 void *DefaultCssmAllocator::malloc(size_t size) throw(std::bad_alloc)
  89 {
  90         if (void *result = ::malloc(size))
  91                 return result;
  92         throw std::bad_alloc();
  93 }
  94
  95 void DefaultCssmAllocator::free(void *addr) throw()
  96 {
  97         ::free(addr);
  98 }
  99
 100 void *DefaultCssmAllocator::realloc(void *addr, size_t newSize) throw(std::bad_alloc)
 101 {
 102         if (void *result = ::realloc(addr, newSize))
 103                 return result;
 104         throw std::bad_alloc();
 105 }
 106
 107 void SensitiveCssmAllocator::free(void *addr) throw()
 108 {
 109     memset(addr, 0, malloc_size(addr));
 110     DefaultCssmAllocator::free(addr);
 111 }
 112
 113 void *SensitiveCssmAllocator::realloc(void *addr, size_t newSize) throw(std::bad_alloc)
 114 {
 115     size_t oldSize = malloc_size(addr);
 116     if (newSize < oldSize)
 117         memset(increment(addr, newSize), 0, oldSize - newSize);
 118     return DefaultCssmAllocator::realloc(addr, newSize);
 119 }
 120
 121 TrackingAllocator::~TrackingAllocator()
 122 {
 123         AllocSet::iterator first = mAllocSet.begin(), last = mAllocSet.end();
 124         for (; first != last; ++first)
 125                 mAllocator.free(*first);
 126 }
 127
 128 //
 129 // CssmMemoryFunctionsAllocators
 130 //
 131 void *CssmMemoryFunctionsAllocator::malloc(size_t size) throw(std::bad_alloc)
 132 { return functions.malloc(size); }
 133
 134 void CssmMemoryFunctionsAllocator::free(void *addr) throw()
 135 { return functions.free(addr); }
 136
 137 void *CssmMemoryFunctionsAllocator::realloc(void *addr, size_t size) throw(std::bad_alloc)
 138 { return functions.realloc(addr, size); }
 139
 140
 141 //
 142 // CssmAllocatorMemoryFunctions
 143 //
 144 CssmAllocatorMemoryFunctions::CssmAllocatorMemoryFunctions(CssmAllocator &alloc)
 145 {
 146         AllocRef = &alloc;
 147         malloc_func = relayMalloc;
 148         free_func = relayFree;
 149         realloc_func = relayRealloc;
 150         calloc_func = relayCalloc;
 151 }
 152
 153 void *CssmAllocatorMemoryFunctions::relayMalloc(size_t size, void *ref) throw(std::bad_alloc)
 154 { return allocator(ref).malloc(size); }
 155
 156 void CssmAllocatorMemoryFunctions::relayFree(void *mem, void *ref) throw()
 157 { allocator(ref).free(mem); }
 158
 159 void *CssmAllocatorMemoryFunctions::relayRealloc(void *mem, size_t size, void *ref) throw(std::bad_alloc)
 160 { return allocator(ref).realloc(mem, size); }
 161
 162 void *CssmAllocatorMemoryFunctions::relayCalloc(uint32 count, size_t size, void *ref) throw(std::bad_alloc)
 163 {
 164         // CssmAllocator doesn't have a calloc() method
 165         void *mem = allocator(ref).malloc(size * count);
 166         memset(mem, 0, size * count);
 167         return mem;
 168 }
 169
 170
 171 //
 172 // Memory allocators for CssmHeap objects.
 173 // This implementation stores a pointer to the allocator used into memory
 174 // *after* the object's proper storage block. This allows the usual free()
 175 // functions to safely free our (hidden) pointer without knowing about it.
 176 // An allocator argument of NULL is interpreted as the standard allocator.
 177 //
 178 void *CssmHeap::operator new (size_t size, CssmAllocator *alloc) throw(std::bad_alloc)
 179 {
 180         if (alloc == NULL)
 181                 alloc = &CssmAllocator::standard();
 182         size = alignUp(size, alignof<CssmAllocator *>());
 183         size_t totalSize = size + sizeof(CssmAllocator *);
 184         void *addr = alloc->malloc(totalSize);
 185         *(CssmAllocator **)increment(addr, size) = alloc;
 186         return addr;
 187 }
 188
 189 void CssmHeap::operator delete (void *addr, size_t size, CssmAllocator *alloc) throw()
 190 {
 191         alloc->free(addr);      // as per C++ std, called (only) if construction fails
 192 }
 193
 194 void CssmHeap::operator delete (void *addr, size_t size) throw()
 195 {
 196         void *end = increment(addr, alignUp(size, alignof<CssmAllocator *>()));
 197         (*(CssmAllocator **)end)->free(addr);
 198 }
 199
 200
 201 //
 202 // CssmVector
 203 //