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1 /*
2  * Copyright (C) 2019 The Android Open Source Project
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
7  * are met:
8  *  * Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  *  * Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in
12  *    the documentation and/or other materials provided with the
13  *    distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
17  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
18  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
19  * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
22  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
25  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <errno.h>
30 #include <malloc.h>
31 #include <stdlib.h>
32 #include <sys/mman.h>
33 #include <sys/param.h>
34 #include <sys/prctl.h>
35 
36 #include "private/bionic_macros.h"
37 
38 #include "scudo.h"
39 
40 // Disable Scudo's mismatch allocation check, as it is being triggered
41 // by some third party code.
__scudo_default_options()42 extern "C" const char *__scudo_default_options() {
43   return "DeallocationTypeMismatch=false";
44 }
45 
AllocTooBig(size_t bytes)46 static inline bool AllocTooBig(size_t bytes) {
47 #if defined(__LP64__)
48   if (__predict_false(bytes > 0x10000000000ULL)) {
49 #else
50   if (__predict_false(bytes > 0x80000000ULL)) {
51 #endif
52     return true;
53   }
54   return false;
55 }
56 
57 void* scudo_aligned_alloc(size_t alignment, size_t size) {
58   if (alignment == 0 || !powerof2(alignment) || (size % alignment) != 0) {
59     errno = EINVAL;
60     return nullptr;
61   }
62   if (AllocTooBig(size)) {
63     errno = ENOMEM;
64     return nullptr;
65   }
66 
67   return aligned_alloc(alignment, size);
68 }
69 
70 void* scudo_calloc(size_t item_count, size_t item_size) {
71   size_t total;
72   if (__builtin_mul_overflow(item_count, item_size, &total) || AllocTooBig(total)) {
73     errno = ENOMEM;
74     return nullptr;
75   }
76   return calloc(item_count, item_size);
77 }
78 
79 void scudo_free(void* ptr) {
80   free(ptr);
81 }
82 
83 extern "C" size_t __sanitizer_get_current_allocated_bytes();
84 extern "C" size_t __sanitizer_get_heap_size();
85 
86 struct mallinfo scudo_mallinfo() {
87   struct mallinfo info {};
88   info.uordblks = __sanitizer_get_current_allocated_bytes();
89   info.hblkhd = __sanitizer_get_heap_size();
90   info.usmblks = info.hblkhd;
91   return info;
92 }
93 
94 void* scudo_malloc(size_t byte_count) {
95   if (AllocTooBig(byte_count)) {
96     errno = ENOMEM;
97     return nullptr;
98   }
99   return malloc(byte_count);
100 }
101 
102 size_t scudo_malloc_usable_size(const void* ptr) {
103   return malloc_usable_size(ptr);
104 }
105 
106 void* scudo_memalign(size_t alignment, size_t byte_count) {
107   if (AllocTooBig(byte_count)) {
108     errno = ENOMEM;
109     return nullptr;
110   }
111   if (alignment != 0) {
112     if (!powerof2(alignment)) {
113       alignment = BIONIC_ROUND_UP_POWER_OF_2(alignment);
114     }
115   } else {
116     alignment = 1;
117   }
118   return memalign(alignment, byte_count);
119 }
120 
121 void* scudo_realloc(void* ptr, size_t byte_count) {
122   if (AllocTooBig(byte_count)) {
123     errno = ENOMEM;
124     return nullptr;
125   }
126   return realloc(ptr, byte_count);
127 }
128 
129 int scudo_posix_memalign(void** memptr, size_t alignment, size_t size) {
130   if (alignment < sizeof(void*) || !powerof2(alignment)) {
131     return EINVAL;
132   }
133   if (AllocTooBig(size)) {
134     return ENOMEM;
135   }
136   return posix_memalign(memptr, alignment, size);
137 }
138 
139 #if defined(HAVE_DEPRECATED_MALLOC_FUNCS)
140 extern "C" void* pvalloc(size_t);
141 
142 void* scudo_pvalloc(size_t size) {
143   if (AllocTooBig(size)) {
144     errno = ENOMEM;
145     return nullptr;
146   }
147   return pvalloc(size);
148 }
149 
150 extern "C" void* valloc(size_t);
151 
152 void* scudo_valloc(size_t size) {
153   if (AllocTooBig(size)) {
154     errno = ENOMEM;
155     return nullptr;
156   }
157   return valloc(size);
158 }
159 #endif
160 
161 // Do not try and name the scudo maps by overriding __sanitizer::internal_mmap.
162 // There is already a function called MmapNamed that names the maps.
163 // Unfortunately, there is no easy way to override MmapNamed because
164 // too much of the code is not compiled into functions available in the
165 // library, and the code is complicated.
166