1 //===- nsan_malloc_linux.cpp ----------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // Interceptors for memory allocation functions on ELF OSes.
10 //
11 //===----------------------------------------------------------------------===//
12
13 #include "interception/interception.h"
14 #include "nsan/nsan.h"
15 #include "sanitizer_common/sanitizer_allocator_dlsym.h"
16 #include "sanitizer_common/sanitizer_common.h"
17 #include "sanitizer_common/sanitizer_platform.h"
18 #include "sanitizer_common/sanitizer_platform_interceptors.h"
19
20 #if !SANITIZER_APPLE && !SANITIZER_WINDOWS
21 using namespace __sanitizer;
22 using __nsan::nsan_initialized;
23
24 namespace {
25 struct DlsymAlloc : public DlSymAllocator<DlsymAlloc> {
UseImpl__anon0d1da7f80111::DlsymAlloc26 static bool UseImpl() { return !nsan_initialized; }
27 };
28 } // namespace
29
INTERCEPTOR(void *,aligned_alloc,uptr align,uptr size)30 INTERCEPTOR(void *, aligned_alloc, uptr align, uptr size) {
31 void *res = REAL(aligned_alloc)(align, size);
32 if (res)
33 __nsan_set_value_unknown(static_cast<u8 *>(res), size);
34 return res;
35 }
36
INTERCEPTOR(void *,calloc,uptr nmemb,uptr size)37 INTERCEPTOR(void *, calloc, uptr nmemb, uptr size) {
38 if (DlsymAlloc::Use())
39 return DlsymAlloc::Callocate(nmemb, size);
40
41 void *res = REAL(calloc)(nmemb, size);
42 if (res)
43 __nsan_set_value_unknown(static_cast<u8 *>(res), nmemb * size);
44 return res;
45 }
46
INTERCEPTOR(void,free,void * ptr)47 INTERCEPTOR(void, free, void *ptr) {
48 if (DlsymAlloc::PointerIsMine(ptr))
49 return DlsymAlloc::Free(ptr);
50 REAL(free)(ptr);
51 }
52
INTERCEPTOR(void *,malloc,uptr size)53 INTERCEPTOR(void *, malloc, uptr size) {
54 if (DlsymAlloc::Use())
55 return DlsymAlloc::Allocate(size);
56 void *res = REAL(malloc)(size);
57 if (res)
58 __nsan_set_value_unknown(static_cast<u8 *>(res), size);
59 return res;
60 }
61
INTERCEPTOR(void *,realloc,void * ptr,uptr size)62 INTERCEPTOR(void *, realloc, void *ptr, uptr size) {
63 if (DlsymAlloc::Use() || DlsymAlloc::PointerIsMine(ptr))
64 return DlsymAlloc::Realloc(ptr, size);
65 void *res = REAL(realloc)(ptr, size);
66 // TODO: We might want to copy the types from the original allocation
67 // (although that would require that we know its size).
68 if (res)
69 __nsan_set_value_unknown(static_cast<u8 *>(res), size);
70 return res;
71 }
72
73 #if SANITIZER_INTERCEPT_REALLOCARRAY
INTERCEPTOR(void *,reallocarray,void * ptr,uptr nmemb,uptr size)74 INTERCEPTOR(void *, reallocarray, void *ptr, uptr nmemb, uptr size) {
75 void *res = REAL(reallocarray)(ptr, nmemb, size);
76 if (res)
77 __nsan_set_value_unknown(static_cast<u8 *>(res), nmemb * size);
78 return res;
79 }
80 #endif // SANITIZER_INTERCEPT_REALLOCARRAY
81
INTERCEPTOR(int,posix_memalign,void ** memptr,uptr align,uptr size)82 INTERCEPTOR(int, posix_memalign, void **memptr, uptr align, uptr size) {
83 int res = REAL(posix_memalign)(memptr, align, size);
84 if (res == 0 && *memptr)
85 __nsan_set_value_unknown(static_cast<u8 *>(*memptr), size);
86 return res;
87 }
88
89 // Deprecated allocation functions (memalign, etc).
90 #if SANITIZER_INTERCEPT_MEMALIGN
INTERCEPTOR(void *,memalign,uptr align,uptr size)91 INTERCEPTOR(void *, memalign, uptr align, uptr size) {
92 void *const res = REAL(memalign)(align, size);
93 if (res)
94 __nsan_set_value_unknown(static_cast<u8 *>(res), size);
95 return res;
96 }
97
INTERCEPTOR(void *,__libc_memalign,uptr align,uptr size)98 INTERCEPTOR(void *, __libc_memalign, uptr align, uptr size) {
99 void *const res = REAL(__libc_memalign)(align, size);
100 if (res)
101 __nsan_set_value_unknown(static_cast<u8 *>(res), size);
102 return res;
103 }
104 #endif
105
InitializeMallocInterceptors()106 void __nsan::InitializeMallocInterceptors() {
107 INTERCEPT_FUNCTION(aligned_alloc);
108 INTERCEPT_FUNCTION(calloc);
109 INTERCEPT_FUNCTION(free);
110 INTERCEPT_FUNCTION(malloc);
111 INTERCEPT_FUNCTION(posix_memalign);
112 INTERCEPT_FUNCTION(realloc);
113 #if SANITIZER_INTERCEPT_REALLOCARRAY
114 INTERCEPT_FUNCTION(reallocarray);
115 #endif
116
117 #if SANITIZER_INTERCEPT_MEMALIGN
118 INTERCEPT_FUNCTION(memalign);
119 INTERCEPT_FUNCTION(__libc_memalign);
120 #endif
121 }
122
123 #endif
124