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. 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 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 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