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 
19 namespace __sanitizer {
20 
21 template <typename Details>
22 struct DlSymAllocator {
23   static bool Use() {
24     // Fuchsia doesn't use dlsym-based interceptors.
25     return !SANITIZER_FUCHSIA && UNLIKELY(Details::UseImpl());
26   }
27 
28   static bool PointerIsMine(const void *ptr) {
29     // Fuchsia doesn't use dlsym-based interceptors.
30     return !SANITIZER_FUCHSIA &&
31            UNLIKELY(internal_allocator()->FromPrimary(ptr));
32   }
33 
34   static void *Allocate(uptr size_in_bytes) {
35     void *ptr = InternalAlloc(size_in_bytes, nullptr, kWordSize);
36     CHECK(internal_allocator()->FromPrimary(ptr));
37     Details::OnAllocate(ptr,
38                         internal_allocator()->GetActuallyAllocatedSize(ptr));
39     return ptr;
40   }
41 
42   static void *Callocate(SIZE_T nmemb, SIZE_T size) {
43     void *ptr = InternalCalloc(nmemb, size);
44     CHECK(internal_allocator()->FromPrimary(ptr));
45     Details::OnAllocate(ptr,
46                         internal_allocator()->GetActuallyAllocatedSize(ptr));
47     return ptr;
48   }
49 
50   static void Free(void *ptr) {
51     uptr size = internal_allocator()->GetActuallyAllocatedSize(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 = internal_allocator()->GetActuallyAllocatedSize(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 OnAllocate(const void *ptr, uptr size) {}
74   static void OnFree(const void *ptr, uptr size) {}
75 };
76 
77 }  // namespace __sanitizer
78 
79 #endif  // SANITIZER_ALLOCATOR_DLSYM_H
80