1 //===-- Unittests for memcpy ----------------------------------------------===//
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 "memory_utils/memory_check_utils.h"
10 #include "src/__support/macros/properties/os.h" // LIBC_TARGET_OS_IS_LINUX
11 #include "src/string/memcpy.h"
12 #include "test/UnitTest/Test.h"
13
14 #if !defined(LIBC_FULL_BUILD) && defined(LIBC_TARGET_OS_IS_LINUX)
15 #include "memory_utils/protected_pages.h"
16 #endif // !defined(LIBC_FULL_BUILD) && defined(LIBC_TARGET_OS_IS_LINUX)
17
18 namespace LIBC_NAMESPACE {
19
20 // Adapt CheckMemcpy signature to memcpy.
Adaptor(cpp::span<char> dst,cpp::span<char> src,size_t size)21 static inline void Adaptor(cpp::span<char> dst, cpp::span<char> src,
22 size_t size) {
23 LIBC_NAMESPACE::memcpy(dst.begin(), src.begin(), size);
24 }
25
TEST(LlvmLibcMemcpyTest,SizeSweep)26 TEST(LlvmLibcMemcpyTest, SizeSweep) {
27 static constexpr size_t kMaxSize = 400;
28 Buffer SrcBuffer(kMaxSize);
29 Buffer DstBuffer(kMaxSize);
30 Randomize(SrcBuffer.span());
31 for (size_t size = 0; size < kMaxSize; ++size) {
32 auto src = SrcBuffer.span().subspan(0, size);
33 auto dst = DstBuffer.span().subspan(0, size);
34 ASSERT_TRUE(CheckMemcpy<Adaptor>(dst, src, size));
35 }
36 }
37
38 #if !defined(LIBC_FULL_BUILD) && defined(LIBC_TARGET_OS_IS_LINUX)
39
TEST(LlvmLibcMemcpyTest,CheckAccess)40 TEST(LlvmLibcMemcpyTest, CheckAccess) {
41 static constexpr size_t MAX_SIZE = 1024;
42 LIBC_ASSERT(MAX_SIZE < GetPageSize());
43 ProtectedPages pages;
44 const Page write_buffer = pages.GetPageA().WithAccess(PROT_WRITE);
45 const Page read_buffer = [&]() {
46 // We fetch page B in write mode.
47 auto page = pages.GetPageB().WithAccess(PROT_WRITE);
48 // And fill it with random numbers.
49 for (size_t i = 0; i < page.page_size; ++i)
50 page.page_ptr[i] = rand();
51 // Then return it in read mode.
52 return page.WithAccess(PROT_READ);
53 }();
54 for (size_t size = 0; size < MAX_SIZE; ++size) {
55 // We cross-check the function with two sources and two destinations.
56 // - The first of them (bottom) is always page aligned and faults when
57 // accessing bytes before it.
58 // - The second one (top) is not necessarily aligned and faults when
59 // accessing bytes after it.
60 const uint8_t *sources[2] = {read_buffer.bottom(size),
61 read_buffer.top(size)};
62 uint8_t *destinations[2] = {write_buffer.bottom(size),
63 write_buffer.top(size)};
64 for (const uint8_t *src : sources) {
65 for (uint8_t *dst : destinations) {
66 LIBC_NAMESPACE::memcpy(dst, src, size);
67 }
68 }
69 }
70 }
71
72 #endif // !defined(LIBC_FULL_BUILD) && defined(LIBC_TARGET_OS_IS_LINUX)
73
74 } // namespace LIBC_NAMESPACE
75