1 //===-- asan_malloc_linux.cc ----------------------------------------------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file is a part of AddressSanitizer, an address sanity checker.
11 //
12 // Linux-specific malloc interception.
13 // We simply define functions like malloc, free, realloc, etc.
14 // They will replace the corresponding libc functions automagically.
15 //===----------------------------------------------------------------------===//
16
17 #include "sanitizer_common/sanitizer_platform.h"
18 #if SANITIZER_FREEBSD || SANITIZER_LINUX
19
20 #include "sanitizer_common/sanitizer_tls_get_addr.h"
21 #include "asan_allocator.h"
22 #include "asan_interceptors.h"
23 #include "asan_internal.h"
24 #include "asan_stack.h"
25
26 // ---------------------- Replacement functions ---------------- {{{1
27 using namespace __asan; // NOLINT
28
INTERCEPTOR(void,free,void * ptr)29 INTERCEPTOR(void, free, void *ptr) {
30 GET_STACK_TRACE_FREE;
31 asan_free(ptr, &stack, FROM_MALLOC);
32 }
33
INTERCEPTOR(void,cfree,void * ptr)34 INTERCEPTOR(void, cfree, void *ptr) {
35 GET_STACK_TRACE_FREE;
36 asan_free(ptr, &stack, FROM_MALLOC);
37 }
38
INTERCEPTOR(void *,malloc,uptr size)39 INTERCEPTOR(void*, malloc, uptr size) {
40 GET_STACK_TRACE_MALLOC;
41 return asan_malloc(size, &stack);
42 }
43
INTERCEPTOR(void *,calloc,uptr nmemb,uptr size)44 INTERCEPTOR(void*, calloc, uptr nmemb, uptr size) {
45 if (UNLIKELY(!asan_inited)) {
46 // Hack: dlsym calls calloc before REAL(calloc) is retrieved from dlsym.
47 const uptr kCallocPoolSize = 1024;
48 static uptr calloc_memory_for_dlsym[kCallocPoolSize];
49 static uptr allocated;
50 uptr size_in_words = ((nmemb * size) + kWordSize - 1) / kWordSize;
51 void *mem = (void*)&calloc_memory_for_dlsym[allocated];
52 allocated += size_in_words;
53 CHECK(allocated < kCallocPoolSize);
54 return mem;
55 }
56 GET_STACK_TRACE_MALLOC;
57 return asan_calloc(nmemb, size, &stack);
58 }
59
INTERCEPTOR(void *,realloc,void * ptr,uptr size)60 INTERCEPTOR(void*, realloc, void *ptr, uptr size) {
61 GET_STACK_TRACE_MALLOC;
62 return asan_realloc(ptr, size, &stack);
63 }
64
INTERCEPTOR(void *,memalign,uptr boundary,uptr size)65 INTERCEPTOR(void*, memalign, uptr boundary, uptr size) {
66 GET_STACK_TRACE_MALLOC;
67 return asan_memalign(boundary, size, &stack, FROM_MALLOC);
68 }
69
INTERCEPTOR(void *,aligned_alloc,uptr boundary,uptr size)70 INTERCEPTOR(void*, aligned_alloc, uptr boundary, uptr size) {
71 GET_STACK_TRACE_MALLOC;
72 return asan_memalign(boundary, size, &stack, FROM_MALLOC);
73 }
74
INTERCEPTOR(void *,__libc_memalign,uptr boundary,uptr size)75 INTERCEPTOR(void*, __libc_memalign, uptr boundary, uptr size) {
76 GET_STACK_TRACE_MALLOC;
77 void *res = asan_memalign(boundary, size, &stack, FROM_MALLOC);
78 DTLS_on_libc_memalign(res, size * boundary);
79 return res;
80 }
81
INTERCEPTOR(uptr,malloc_usable_size,void * ptr)82 INTERCEPTOR(uptr, malloc_usable_size, void *ptr) {
83 GET_CURRENT_PC_BP_SP;
84 (void)sp;
85 return asan_malloc_usable_size(ptr, pc, bp);
86 }
87
88 // We avoid including malloc.h for portability reasons.
89 // man mallinfo says the fields are "long", but the implementation uses int.
90 // It doesn't matter much -- we just need to make sure that the libc's mallinfo
91 // is not called.
92 struct fake_mallinfo {
93 int x[10];
94 };
95
INTERCEPTOR(struct fake_mallinfo,mallinfo,void)96 INTERCEPTOR(struct fake_mallinfo, mallinfo, void) {
97 struct fake_mallinfo res;
98 REAL(memset)(&res, 0, sizeof(res));
99 return res;
100 }
101
INTERCEPTOR(int,mallopt,int cmd,int value)102 INTERCEPTOR(int, mallopt, int cmd, int value) {
103 return -1;
104 }
105
INTERCEPTOR(int,posix_memalign,void ** memptr,uptr alignment,uptr size)106 INTERCEPTOR(int, posix_memalign, void **memptr, uptr alignment, uptr size) {
107 GET_STACK_TRACE_MALLOC;
108 // Printf("posix_memalign: %zx %zu\n", alignment, size);
109 return asan_posix_memalign(memptr, alignment, size, &stack);
110 }
111
INTERCEPTOR(void *,valloc,uptr size)112 INTERCEPTOR(void*, valloc, uptr size) {
113 GET_STACK_TRACE_MALLOC;
114 return asan_valloc(size, &stack);
115 }
116
INTERCEPTOR(void *,pvalloc,uptr size)117 INTERCEPTOR(void*, pvalloc, uptr size) {
118 GET_STACK_TRACE_MALLOC;
119 return asan_pvalloc(size, &stack);
120 }
121
INTERCEPTOR(void,malloc_stats,void)122 INTERCEPTOR(void, malloc_stats, void) {
123 __asan_print_accumulated_stats();
124 }
125
126 #if SANITIZER_ANDROID
127 // Format of __libc_malloc_dispatch has changed in Android L.
128 // While we are moving towards a solution that does not depend on bionic
129 // internals, here is something to support both K* and L releases.
130 struct MallocDebugK {
131 void *(*malloc)(uptr bytes);
132 void (*free)(void *mem);
133 void *(*calloc)(uptr n_elements, uptr elem_size);
134 void *(*realloc)(void *oldMem, uptr bytes);
135 void *(*memalign)(uptr alignment, uptr bytes);
136 uptr (*malloc_usable_size)(void *mem);
137 };
138
139 struct MallocDebugL {
140 void *(*calloc)(uptr n_elements, uptr elem_size);
141 void (*free)(void *mem);
142 fake_mallinfo (*mallinfo)(void);
143 void *(*malloc)(uptr bytes);
144 uptr (*malloc_usable_size)(void *mem);
145 void *(*memalign)(uptr alignment, uptr bytes);
146 int (*posix_memalign)(void **memptr, uptr alignment, uptr size);
147 void* (*pvalloc)(uptr size);
148 void *(*realloc)(void *oldMem, uptr bytes);
149 void* (*valloc)(uptr size);
150 };
151
152 ALIGNED(32) const MallocDebugK asan_malloc_dispatch_k = {
153 WRAP(malloc), WRAP(free), WRAP(calloc),
154 WRAP(realloc), WRAP(memalign), WRAP(malloc_usable_size)};
155
156 ALIGNED(32) const MallocDebugL asan_malloc_dispatch_l = {
157 WRAP(calloc), WRAP(free), WRAP(mallinfo),
158 WRAP(malloc), WRAP(malloc_usable_size), WRAP(memalign),
159 WRAP(posix_memalign), WRAP(pvalloc), WRAP(realloc),
160 WRAP(valloc)};
161
162 namespace __asan {
ReplaceSystemMalloc()163 void ReplaceSystemMalloc() {
164 void **__libc_malloc_dispatch_p =
165 (void **)AsanDlSymNext("__libc_malloc_dispatch");
166 if (__libc_malloc_dispatch_p) {
167 // Decide on K vs L dispatch format by the presence of
168 // __libc_malloc_default_dispatch export in libc.
169 void *default_dispatch_p = AsanDlSymNext("__libc_malloc_default_dispatch");
170 if (default_dispatch_p)
171 *__libc_malloc_dispatch_p = (void *)&asan_malloc_dispatch_k;
172 else
173 *__libc_malloc_dispatch_p = (void *)&asan_malloc_dispatch_l;
174 }
175 }
176 } // namespace __asan
177
178 #else // SANITIZER_ANDROID
179
180 namespace __asan {
ReplaceSystemMalloc()181 void ReplaceSystemMalloc() {
182 }
183 } // namespace __asan
184 #endif // SANITIZER_ANDROID
185
186 #endif // SANITIZER_FREEBSD || SANITIZER_LINUX
187