xref: /llvm-project/compiler-rt/lib/sanitizer_common/sanitizer_allocator_dlsym.h (revision e8c8543a1c728278bf323d34e451bcf9042d9257)
1 //===-- sanitizer_allocator_dlsym.h -----------------------------*- C++ -*-===//
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 // Hack: Sanitizer initializer calls dlsym which may need to allocate and call
10 // back into uninitialized sanitizer.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef SANITIZER_ALLOCATOR_DLSYM_H
15 #define SANITIZER_ALLOCATOR_DLSYM_H
16 
17 #include "sanitizer_allocator_internal.h"
18 #include "sanitizer_common/sanitizer_allocator_checks.h"
19 #include "sanitizer_common/sanitizer_internal_defs.h"
20 
21 namespace __sanitizer {
22 
23 template <typename Details>
24 struct DlSymAllocator {
25   static bool Use() {
26     // Fuchsia doesn't use dlsym-based interceptors.
27     return !SANITIZER_FUCHSIA && UNLIKELY(Details::UseImpl());
28   }
29 
30   static bool PointerIsMine(const void *ptr) {
31     // Fuchsia doesn't use dlsym-based interceptors.
32     return !SANITIZER_FUCHSIA &&
33            UNLIKELY(internal_allocator()->FromPrimary(ptr));
34   }
35 
36   static void *Allocate(uptr size_in_bytes, uptr align = kWordSize) {
37     void *ptr = InternalAlloc(size_in_bytes, nullptr, align);
38     CHECK(internal_allocator()->FromPrimary(ptr));
39     Details::OnAllocate(ptr, GetSize(ptr));
40     return ptr;
41   }
42 
43   static void *Callocate(usize nmemb, usize size) {
44     void *ptr = InternalCalloc(nmemb, size);
45     CHECK(internal_allocator()->FromPrimary(ptr));
46     Details::OnAllocate(ptr, GetSize(ptr));
47     return ptr;
48   }
49 
50   static void Free(void *ptr) {
51     uptr size = GetSize(ptr);
52     Details::OnFree(ptr, size);
53     InternalFree(ptr);
54   }
55 
56   static void *Realloc(void *ptr, uptr new_size) {
57     if (!ptr)
58       return Allocate(new_size);
59     CHECK(internal_allocator()->FromPrimary(ptr));
60     if (!new_size) {
61       Free(ptr);
62       return nullptr;
63     }
64     uptr size = GetSize(ptr);
65     uptr memcpy_size = Min(new_size, size);
66     void *new_ptr = Allocate(new_size);
67     if (new_ptr)
68       internal_memcpy(new_ptr, ptr, memcpy_size);
69     Free(ptr);
70     return new_ptr;
71   }
72 
73   static void *ReallocArray(void *ptr, uptr count, uptr size) {
74     CHECK(!CheckForCallocOverflow(count, size));
75     return Realloc(ptr, count * size);
76   }
77 
78   static uptr GetSize(void *ptr) {
79     return internal_allocator()->GetActuallyAllocatedSize(ptr);
80   }
81 
82   static void OnAllocate(const void *ptr, uptr size) {}
83   static void OnFree(const void *ptr, uptr size) {}
84 };
85 
86 }  // namespace __sanitizer
87 
88 #endif  // SANITIZER_ALLOCATOR_DLSYM_H
89