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/config.h"
11 #include "src/__support/macros/properties/os.h" // LIBC_TARGET_OS_IS_LINUX
12 #include "src/string/memcpy.h"
13 #include "test/UnitTest/Test.h"
14
15 #if !defined(LIBC_FULL_BUILD) && defined(LIBC_TARGET_OS_IS_LINUX)
16 #include "memory_utils/protected_pages.h"
17 #endif // !defined(LIBC_FULL_BUILD) && defined(LIBC_TARGET_OS_IS_LINUX)
18
19 namespace LIBC_NAMESPACE_DECL {
20
21 // Adapt CheckMemcpy signature to memcpy.
Adaptor(cpp::span<char> dst,cpp::span<char> src,size_t size)22 static inline void Adaptor(cpp::span<char> dst, cpp::span<char> src,
23 size_t size) {
24 LIBC_NAMESPACE::memcpy(dst.begin(), src.begin(), size);
25 }
26
TEST(LlvmLibcMemcpyTest,SizeSweep)27 TEST(LlvmLibcMemcpyTest, SizeSweep) {
28 static constexpr size_t kMaxSize = 400;
29 Buffer SrcBuffer(kMaxSize);
30 Buffer DstBuffer(kMaxSize);
31 Randomize(SrcBuffer.span());
32 for (size_t size = 0; size < kMaxSize; ++size) {
33 auto src = SrcBuffer.span().subspan(0, size);
34 auto dst = DstBuffer.span().subspan(0, size);
35 ASSERT_TRUE(CheckMemcpy<Adaptor>(dst, src, size));
36 }
37 }
38
39 #if !defined(LIBC_FULL_BUILD) && defined(LIBC_TARGET_OS_IS_LINUX)
40
TEST(LlvmLibcMemcpyTest,CheckAccess)41 TEST(LlvmLibcMemcpyTest, CheckAccess) {
42 static constexpr size_t MAX_SIZE = 1024;
43 LIBC_ASSERT(MAX_SIZE < GetPageSize());
44 ProtectedPages pages;
45 const Page write_buffer = pages.GetPageA().WithAccess(PROT_WRITE);
46 const Page read_buffer = [&]() {
47 // We fetch page B in write mode.
48 auto page = pages.GetPageB().WithAccess(PROT_WRITE);
49 // And fill it with random numbers.
50 for (size_t i = 0; i < page.page_size; ++i)
51 page.page_ptr[i] = rand();
52 // Then return it in read mode.
53 return page.WithAccess(PROT_READ);
54 }();
55 for (size_t size = 0; size < MAX_SIZE; ++size) {
56 // We cross-check the function with two sources and two destinations.
57 // - The first of them (bottom) is always page aligned and faults when
58 // accessing bytes before it.
59 // - The second one (top) is not necessarily aligned and faults when
60 // accessing bytes after it.
61 const uint8_t *sources[2] = {read_buffer.bottom(size),
62 read_buffer.top(size)};
63 uint8_t *destinations[2] = {write_buffer.bottom(size),
64 write_buffer.top(size)};
65 for (const uint8_t *src : sources) {
66 for (uint8_t *dst : destinations) {
67 LIBC_NAMESPACE::memcpy(dst, src, size);
68 }
69 }
70 }
71 }
72
73 #endif // !defined(LIBC_FULL_BUILD) && defined(LIBC_TARGET_OS_IS_LINUX)
74
75 } // namespace LIBC_NAMESPACE_DECL
76