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
21namespace __sanitizer {
22
23template <typename Details>
24struct 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