alignment.cpp revision 1.1.1.4 
1//===-- alignment.cpp -------------------------------------------*- 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#include "gwp_asan/guarded_pool_allocator.h"
10#include "gwp_asan/tests/harness.h"
11
12class AlignmentTestGPA : public gwp_asan::GuardedPoolAllocator {
13public:
14  static size_t getRequiredBackingSize(size_t Size, size_t Alignment,
15                                       size_t PageSize) {
16    return GuardedPoolAllocator::getRequiredBackingSize(Size, Alignment,
17                                                        PageSize);
18  }
19  static uintptr_t alignUp(uintptr_t Ptr, size_t Alignment) {
20    return GuardedPoolAllocator::alignUp(Ptr, Alignment);
21  }
22  static uintptr_t alignDown(uintptr_t Ptr, size_t Alignment) {
23    return GuardedPoolAllocator::alignDown(Ptr, Alignment);
24  }
25};
26
27// Global assumptions for these tests:
28//   1. Page size is 0x1000.
29//   2. All tests assume a slot is multipage, between 0x4000 - 0x8000. While we
30//      don't use multipage slots right now, this tests more boundary conditions
31//      and allows us to add this feature at a later date without rewriting the
32//      alignment functionality.
33// These aren't actual requirements of the allocator - but just simplifies the
34// numerics of the testing.
35TEST(AlignmentTest, LeftAlignedAllocs) {
36  // Alignment < Page Size.
37  EXPECT_EQ(0x4000u, AlignmentTestGPA::alignUp(
38                         /* Ptr */ 0x4000, /* Alignment */ 0x1));
39  // Alignment == Page Size.
40  EXPECT_EQ(0x4000u, AlignmentTestGPA::alignUp(
41                         /* Ptr */ 0x4000, /* Alignment */ 0x1000));
42  // Alignment > Page Size.
43  EXPECT_EQ(0x4000u, AlignmentTestGPA::alignUp(
44                         /* Ptr */ 0x4000, /* Alignment */ 0x4000));
45}
46
47TEST(AlignmentTest, SingleByteAllocs) {
48  // Alignment < Page Size.
49  EXPECT_EQ(0x1u,
50            AlignmentTestGPA::getRequiredBackingSize(
51                /* Size */ 0x1, /* Alignment */ 0x1, /* PageSize */ 0x1000));
52  EXPECT_EQ(0x7fffu, AlignmentTestGPA::alignDown(
53                         /* Ptr */ 0x8000 - 0x1, /* Alignment */ 0x1));
54
55  // Alignment == Page Size.
56  EXPECT_EQ(0x1u,
57            AlignmentTestGPA::getRequiredBackingSize(
58                /* Size */ 0x1, /* Alignment */ 0x1000, /* PageSize */ 0x1000));
59  EXPECT_EQ(0x7000u, AlignmentTestGPA::alignDown(
60                         /* Ptr */ 0x8000 - 0x1, /* Alignment */ 0x1000));
61
62  // Alignment > Page Size.
63  EXPECT_EQ(0x3001u,
64            AlignmentTestGPA::getRequiredBackingSize(
65                /* Size */ 0x1, /* Alignment */ 0x4000, /* PageSize */ 0x1000));
66  EXPECT_EQ(0x4000u, AlignmentTestGPA::alignDown(
67                         /* Ptr */ 0x8000 - 0x1, /* Alignment */ 0x4000));
68}
69
70TEST(AlignmentTest, PageSizedAllocs) {
71  // Alignment < Page Size.
72  EXPECT_EQ(0x1000u,
73            AlignmentTestGPA::getRequiredBackingSize(
74                /* Size */ 0x1000, /* Alignment */ 0x1, /* PageSize */ 0x1000));
75  EXPECT_EQ(0x7000u, AlignmentTestGPA::alignDown(
76                         /* Ptr */ 0x8000 - 0x1000, /* Alignment */ 0x1));
77
78  // Alignment == Page Size.
79  EXPECT_EQ(0x1000u, AlignmentTestGPA::getRequiredBackingSize(
80                         /* Size */ 0x1000, /* Alignment */ 0x1000,
81                         /* PageSize */ 0x1000));
82  EXPECT_EQ(0x7000u, AlignmentTestGPA::alignDown(
83                         /* Ptr */ 0x8000 - 0x1000, /* Alignment */ 0x1000));
84
85  // Alignment > Page Size.
86  EXPECT_EQ(0x4000u, AlignmentTestGPA::getRequiredBackingSize(
87                         /* Size */ 0x1000, /* Alignment */ 0x4000,
88                         /* PageSize */ 0x1000));
89  EXPECT_EQ(0x4000u, AlignmentTestGPA::alignDown(
90                         /* Ptr */ 0x8000 - 0x1000, /* Alignment */ 0x4000));
91}
92
93TEST(AlignmentTest, MoreThanPageAllocs) {
94  // Alignment < Page Size.
95  EXPECT_EQ(0x2fffu,
96            AlignmentTestGPA::getRequiredBackingSize(
97                /* Size */ 0x2fff, /* Alignment */ 0x1, /* PageSize */ 0x1000));
98  EXPECT_EQ(0x5001u, AlignmentTestGPA::alignDown(
99                         /* Ptr */ 0x8000 - 0x2fff, /* Alignment */ 0x1));
100
101  // Alignment == Page Size.
102  EXPECT_EQ(0x2fffu, AlignmentTestGPA::getRequiredBackingSize(
103                         /* Size */ 0x2fff, /* Alignment */ 0x1000,
104                         /* PageSize */ 0x1000));
105  EXPECT_EQ(0x5000u, AlignmentTestGPA::alignDown(
106                         /* Ptr */ 0x8000 - 0x2fff, /* Alignment */ 0x1000));
107
108  // Alignment > Page Size.
109  EXPECT_EQ(0x5fffu, AlignmentTestGPA::getRequiredBackingSize(
110                         /* Size */ 0x2fff, /* Alignment */ 0x4000,
111                         /* PageSize */ 0x1000));
112  EXPECT_EQ(0x4000u, AlignmentTestGPA::alignDown(
113                         /* Ptr */ 0x8000 - 0x2fff, /* Alignment */ 0x4000));
114}
115