| //===-- Memory.cpp --------------------------------------------------------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "lldb/Target/Memory.h" |
| #include "lldb/Target/Process.h" |
| #include "lldb/Utility/DataBufferHeap.h" |
| #include "lldb/Utility/LLDBLog.h" |
| #include "lldb/Utility/Log.h" |
| #include "lldb/Utility/RangeMap.h" |
| #include "lldb/Utility/State.h" |
| |
| #include <cinttypes> |
| #include <memory> |
| |
| using namespace lldb; |
| using namespace lldb_private; |
| |
| // MemoryCache constructor |
| MemoryCache::MemoryCache(Process &process) |
| : m_mutex(), m_L1_cache(), m_L2_cache(), m_invalid_ranges(), |
| m_process(process), |
| m_L2_cache_line_byte_size(process.GetMemoryCacheLineSize()) {} |
| |
| // Destructor |
| MemoryCache::~MemoryCache() = default; |
| |
| void MemoryCache::Clear(bool clear_invalid_ranges) { |
| std::lock_guard<std::recursive_mutex> guard(m_mutex); |
| m_L1_cache.clear(); |
| m_L2_cache.clear(); |
| if (clear_invalid_ranges) |
| m_invalid_ranges.Clear(); |
| m_L2_cache_line_byte_size = m_process.GetMemoryCacheLineSize(); |
| } |
| |
| void MemoryCache::AddL1CacheData(lldb::addr_t addr, const void *src, |
| size_t src_len) { |
| AddL1CacheData( |
| addr, DataBufferSP(new DataBufferHeap(DataBufferHeap(src, src_len)))); |
| } |
| |
| void MemoryCache::AddL1CacheData(lldb::addr_t addr, |
| const DataBufferSP &data_buffer_sp) { |
| std::lock_guard<std::recursive_mutex> guard(m_mutex); |
| m_L1_cache[addr] = data_buffer_sp; |
| } |
| |
| void MemoryCache::Flush(addr_t addr, size_t size) { |
| if (size == 0) |
| return; |
| |
| std::lock_guard<std::recursive_mutex> guard(m_mutex); |
| |
| // Erase any blocks from the L1 cache that intersect with the flush range |
| if (!m_L1_cache.empty()) { |
| AddrRange flush_range(addr, size); |
| BlockMap::iterator pos = m_L1_cache.upper_bound(addr); |
| if (pos != m_L1_cache.begin()) { |
| --pos; |
| } |
| while (pos != m_L1_cache.end()) { |
| AddrRange chunk_range(pos->first, pos->second->GetByteSize()); |
| if (!chunk_range.DoesIntersect(flush_range)) |
| break; |
| pos = m_L1_cache.erase(pos); |
| } |
| } |
| |
| if (!m_L2_cache.empty()) { |
| const uint32_t cache_line_byte_size = m_L2_cache_line_byte_size; |
| const addr_t end_addr = (addr + size - 1); |
| const addr_t first_cache_line_addr = addr - (addr % cache_line_byte_size); |
| const addr_t last_cache_line_addr = |
| end_addr - (end_addr % cache_line_byte_size); |
| // Watch for overflow where size will cause us to go off the end of the |
| // 64 bit address space |
| uint32_t num_cache_lines; |
| if (last_cache_line_addr >= first_cache_line_addr) |
| num_cache_lines = ((last_cache_line_addr - first_cache_line_addr) / |
| cache_line_byte_size) + |
| 1; |
| else |
| num_cache_lines = |
| (UINT64_MAX - first_cache_line_addr + 1) / cache_line_byte_size; |
| |
| uint32_t cache_idx = 0; |
| for (addr_t curr_addr = first_cache_line_addr; cache_idx < num_cache_lines; |
| curr_addr += cache_line_byte_size, ++cache_idx) { |
| BlockMap::iterator pos = m_L2_cache.find(curr_addr); |
| if (pos != m_L2_cache.end()) |
| m_L2_cache.erase(pos); |
| } |
| } |
| } |
| |
| void MemoryCache::AddInvalidRange(lldb::addr_t base_addr, |
| lldb::addr_t byte_size) { |
| if (byte_size > 0) { |
| std::lock_guard<std::recursive_mutex> guard(m_mutex); |
| InvalidRanges::Entry range(base_addr, byte_size); |
| m_invalid_ranges.Append(range); |
| m_invalid_ranges.Sort(); |
| } |
| } |
| |
| bool MemoryCache::RemoveInvalidRange(lldb::addr_t base_addr, |
| lldb::addr_t byte_size) { |
| if (byte_size > 0) { |
| std::lock_guard<std::recursive_mutex> guard(m_mutex); |
| const uint32_t idx = m_invalid_ranges.FindEntryIndexThatContains(base_addr); |
| if (idx != UINT32_MAX) { |
| const InvalidRanges::Entry *entry = m_invalid_ranges.GetEntryAtIndex(idx); |
| if (entry->GetRangeBase() == base_addr && |
| entry->GetByteSize() == byte_size) |
| return m_invalid_ranges.RemoveEntryAtIndex(idx); |
| } |
| } |
| return false; |
| } |
| |
| lldb::DataBufferSP MemoryCache::GetL2CacheLine(lldb::addr_t line_base_addr, |
| Status &error) { |
| // This function assumes that the address given is aligned correctly. |
| assert((line_base_addr % m_L2_cache_line_byte_size) == 0); |
| |
| std::lock_guard<std::recursive_mutex> guard(m_mutex); |
| auto pos = m_L2_cache.find(line_base_addr); |
| if (pos != m_L2_cache.end()) |
| return pos->second; |
| |
| auto data_buffer_heap_sp = |
| std::make_shared<DataBufferHeap>(m_L2_cache_line_byte_size, 0); |
| size_t process_bytes_read = m_process.ReadMemoryFromInferior( |
| line_base_addr, data_buffer_heap_sp->GetBytes(), |
| data_buffer_heap_sp->GetByteSize(), error); |
| |
| // If we failed a read, not much we can do. |
| if (process_bytes_read == 0) |
| return lldb::DataBufferSP(); |
| |
| // If we didn't get a complete read, we can still cache what we did get. |
| if (process_bytes_read < m_L2_cache_line_byte_size) |
| data_buffer_heap_sp->SetByteSize(process_bytes_read); |
| |
| m_L2_cache[line_base_addr] = data_buffer_heap_sp; |
| return data_buffer_heap_sp; |
| } |
| |
| size_t MemoryCache::Read(addr_t addr, void *dst, size_t dst_len, |
| Status &error) { |
| if (!dst || dst_len == 0) |
| return 0; |
| |
| std::lock_guard<std::recursive_mutex> guard(m_mutex); |
| // FIXME: We should do a more thorough check to make sure that we're not |
| // overlapping with any invalid ranges (e.g. Read 0x100 - 0x200 but there's an |
| // invalid range 0x180 - 0x280). `FindEntryThatContains` has an implementation |
| // that takes a range, but it only checks to see if the argument is contained |
| // by an existing invalid range. It cannot check if the argument contains |
| // invalid ranges and cannot check for overlaps. |
| if (m_invalid_ranges.FindEntryThatContains(addr)) { |
| error.SetErrorStringWithFormat("memory read failed for 0x%" PRIx64, addr); |
| return 0; |
| } |
| |
| // Check the L1 cache for a range that contains the entire memory read. |
| // L1 cache contains chunks of memory that are not required to be the size of |
| // an L2 cache line. We avoid trying to do partial reads from the L1 cache to |
| // simplify the implementation. |
| if (!m_L1_cache.empty()) { |
| AddrRange read_range(addr, dst_len); |
| BlockMap::iterator pos = m_L1_cache.upper_bound(addr); |
| if (pos != m_L1_cache.begin()) { |
| --pos; |
| } |
| AddrRange chunk_range(pos->first, pos->second->GetByteSize()); |
| if (chunk_range.Contains(read_range)) { |
| memcpy(dst, pos->second->GetBytes() + (addr - chunk_range.GetRangeBase()), |
| dst_len); |
| return dst_len; |
| } |
| } |
| |
| // If the size of the read is greater than the size of an L2 cache line, we'll |
| // just read from the inferior. If that read is successful, we'll cache what |
| // we read in the L1 cache for future use. |
| if (dst_len > m_L2_cache_line_byte_size) { |
| size_t bytes_read = |
| m_process.ReadMemoryFromInferior(addr, dst, dst_len, error); |
| if (bytes_read > 0) |
| AddL1CacheData(addr, dst, bytes_read); |
| return bytes_read; |
| } |
| |
| // If the size of the read fits inside one L2 cache line, we'll try reading |
| // from the L2 cache. Note that if the range of memory we're reading sits |
| // between two contiguous cache lines, we'll touch two cache lines instead of |
| // just one. |
| |
| // We're going to have all of our loads and reads be cache line aligned. |
| addr_t cache_line_offset = addr % m_L2_cache_line_byte_size; |
| addr_t cache_line_base_addr = addr - cache_line_offset; |
| DataBufferSP first_cache_line = GetL2CacheLine(cache_line_base_addr, error); |
| // If we get nothing, then the read to the inferior likely failed. Nothing to |
| // do here. |
| if (!first_cache_line) |
| return 0; |
| |
| // If the cache line was not filled out completely and the offset is greater |
| // than what we have available, we can't do anything further here. |
| if (cache_line_offset >= first_cache_line->GetByteSize()) |
| return 0; |
| |
| uint8_t *dst_buf = (uint8_t *)dst; |
| size_t bytes_left = dst_len; |
| size_t read_size = first_cache_line->GetByteSize() - cache_line_offset; |
| if (read_size > bytes_left) |
| read_size = bytes_left; |
| |
| memcpy(dst_buf + dst_len - bytes_left, |
| first_cache_line->GetBytes() + cache_line_offset, read_size); |
| bytes_left -= read_size; |
| |
| // If the cache line was not filled out completely and we still have data to |
| // read, we can't do anything further. |
| if (first_cache_line->GetByteSize() < m_L2_cache_line_byte_size && |
| bytes_left > 0) |
| return dst_len - bytes_left; |
| |
| // We'll hit this scenario if our read straddles two cache lines. |
| if (bytes_left > 0) { |
| cache_line_base_addr += m_L2_cache_line_byte_size; |
| |
| // FIXME: Until we are able to more thoroughly check for invalid ranges, we |
| // will have to check the second line to see if it is in an invalid range as |
| // well. See the check near the beginning of the function for more details. |
| if (m_invalid_ranges.FindEntryThatContains(cache_line_base_addr)) { |
| error.SetErrorStringWithFormat("memory read failed for 0x%" PRIx64, |
| cache_line_base_addr); |
| return dst_len - bytes_left; |
| } |
| |
| DataBufferSP second_cache_line = |
| GetL2CacheLine(cache_line_base_addr, error); |
| if (!second_cache_line) |
| return dst_len - bytes_left; |
| |
| read_size = bytes_left; |
| if (read_size > second_cache_line->GetByteSize()) |
| read_size = second_cache_line->GetByteSize(); |
| |
| memcpy(dst_buf + dst_len - bytes_left, second_cache_line->GetBytes(), |
| read_size); |
| bytes_left -= read_size; |
| |
| return dst_len - bytes_left; |
| } |
| |
| return dst_len; |
| } |
| |
| AllocatedBlock::AllocatedBlock(lldb::addr_t addr, uint32_t byte_size, |
| uint32_t permissions, uint32_t chunk_size) |
| : m_range(addr, byte_size), m_permissions(permissions), |
| m_chunk_size(chunk_size) |
| { |
| // The entire address range is free to start with. |
| m_free_blocks.Append(m_range); |
| assert(byte_size > chunk_size); |
| } |
| |
| AllocatedBlock::~AllocatedBlock() = default; |
| |
| lldb::addr_t AllocatedBlock::ReserveBlock(uint32_t size) { |
| // We must return something valid for zero bytes. |
| if (size == 0) |
| size = 1; |
| Log *log = GetLog(LLDBLog::Process); |
| |
| const size_t free_count = m_free_blocks.GetSize(); |
| for (size_t i=0; i<free_count; ++i) |
| { |
| auto &free_block = m_free_blocks.GetEntryRef(i); |
| const lldb::addr_t range_size = free_block.GetByteSize(); |
| if (range_size >= size) |
| { |
| // We found a free block that is big enough for our data. Figure out how |
| // many chunks we will need and calculate the resulting block size we |
| // will reserve. |
| addr_t addr = free_block.GetRangeBase(); |
| size_t num_chunks = CalculateChunksNeededForSize(size); |
| lldb::addr_t block_size = num_chunks * m_chunk_size; |
| lldb::addr_t bytes_left = range_size - block_size; |
| if (bytes_left == 0) |
| { |
| // The newly allocated block will take all of the bytes in this |
| // available block, so we can just add it to the allocated ranges and |
| // remove the range from the free ranges. |
| m_reserved_blocks.Insert(free_block, false); |
| m_free_blocks.RemoveEntryAtIndex(i); |
| } |
| else |
| { |
| // Make the new allocated range and add it to the allocated ranges. |
| Range<lldb::addr_t, uint32_t> reserved_block(free_block); |
| reserved_block.SetByteSize(block_size); |
| // Insert the reserved range and don't combine it with other blocks in |
| // the reserved blocks list. |
| m_reserved_blocks.Insert(reserved_block, false); |
| // Adjust the free range in place since we won't change the sorted |
| // ordering of the m_free_blocks list. |
| free_block.SetRangeBase(reserved_block.GetRangeEnd()); |
| free_block.SetByteSize(bytes_left); |
| } |
| LLDB_LOGV(log, "({0}) (size = {1} ({1:x})) => {2:x}", this, size, addr); |
| return addr; |
| } |
| } |
| |
| LLDB_LOGV(log, "({0}) (size = {1} ({1:x})) => {2:x}", this, size, |
| LLDB_INVALID_ADDRESS); |
| return LLDB_INVALID_ADDRESS; |
| } |
| |
| bool AllocatedBlock::FreeBlock(addr_t addr) { |
| bool success = false; |
| auto entry_idx = m_reserved_blocks.FindEntryIndexThatContains(addr); |
| if (entry_idx != UINT32_MAX) |
| { |
| m_free_blocks.Insert(m_reserved_blocks.GetEntryRef(entry_idx), true); |
| m_reserved_blocks.RemoveEntryAtIndex(entry_idx); |
| success = true; |
| } |
| Log *log = GetLog(LLDBLog::Process); |
| LLDB_LOGV(log, "({0}) (addr = {1:x}) => {2}", this, addr, success); |
| return success; |
| } |
| |
| AllocatedMemoryCache::AllocatedMemoryCache(Process &process) |
| : m_process(process), m_mutex(), m_memory_map() {} |
| |
| AllocatedMemoryCache::~AllocatedMemoryCache() = default; |
| |
| void AllocatedMemoryCache::Clear(bool deallocate_memory) { |
| std::lock_guard<std::recursive_mutex> guard(m_mutex); |
| if (m_process.IsAlive() && deallocate_memory) { |
| PermissionsToBlockMap::iterator pos, end = m_memory_map.end(); |
| for (pos = m_memory_map.begin(); pos != end; ++pos) |
| m_process.DoDeallocateMemory(pos->second->GetBaseAddress()); |
| } |
| m_memory_map.clear(); |
| } |
| |
| AllocatedMemoryCache::AllocatedBlockSP |
| AllocatedMemoryCache::AllocatePage(uint32_t byte_size, uint32_t permissions, |
| uint32_t chunk_size, Status &error) { |
| AllocatedBlockSP block_sp; |
| const size_t page_size = 4096; |
| const size_t num_pages = (byte_size + page_size - 1) / page_size; |
| const size_t page_byte_size = num_pages * page_size; |
| |
| addr_t addr = m_process.DoAllocateMemory(page_byte_size, permissions, error); |
| |
| Log *log = GetLog(LLDBLog::Process); |
| if (log) { |
| LLDB_LOGF(log, |
| "Process::DoAllocateMemory (byte_size = 0x%8.8" PRIx32 |
| ", permissions = %s) => 0x%16.16" PRIx64, |
| (uint32_t)page_byte_size, GetPermissionsAsCString(permissions), |
| (uint64_t)addr); |
| } |
| |
| if (addr != LLDB_INVALID_ADDRESS) { |
| block_sp = std::make_shared<AllocatedBlock>(addr, page_byte_size, |
| permissions, chunk_size); |
| m_memory_map.insert(std::make_pair(permissions, block_sp)); |
| } |
| return block_sp; |
| } |
| |
| lldb::addr_t AllocatedMemoryCache::AllocateMemory(size_t byte_size, |
| uint32_t permissions, |
| Status &error) { |
| std::lock_guard<std::recursive_mutex> guard(m_mutex); |
| |
| addr_t addr = LLDB_INVALID_ADDRESS; |
| std::pair<PermissionsToBlockMap::iterator, PermissionsToBlockMap::iterator> |
| range = m_memory_map.equal_range(permissions); |
| |
| for (PermissionsToBlockMap::iterator pos = range.first; pos != range.second; |
| ++pos) { |
| addr = (*pos).second->ReserveBlock(byte_size); |
| if (addr != LLDB_INVALID_ADDRESS) |
| break; |
| } |
| |
| if (addr == LLDB_INVALID_ADDRESS) { |
| AllocatedBlockSP block_sp(AllocatePage(byte_size, permissions, 16, error)); |
| |
| if (block_sp) |
| addr = block_sp->ReserveBlock(byte_size); |
| } |
| Log *log = GetLog(LLDBLog::Process); |
| LLDB_LOGF(log, |
| "AllocatedMemoryCache::AllocateMemory (byte_size = 0x%8.8" PRIx32 |
| ", permissions = %s) => 0x%16.16" PRIx64, |
| (uint32_t)byte_size, GetPermissionsAsCString(permissions), |
| (uint64_t)addr); |
| return addr; |
| } |
| |
| bool AllocatedMemoryCache::DeallocateMemory(lldb::addr_t addr) { |
| std::lock_guard<std::recursive_mutex> guard(m_mutex); |
| |
| PermissionsToBlockMap::iterator pos, end = m_memory_map.end(); |
| bool success = false; |
| for (pos = m_memory_map.begin(); pos != end; ++pos) { |
| if (pos->second->Contains(addr)) { |
| success = pos->second->FreeBlock(addr); |
| break; |
| } |
| } |
| Log *log = GetLog(LLDBLog::Process); |
| LLDB_LOGF(log, |
| "AllocatedMemoryCache::DeallocateMemory (addr = 0x%16.16" PRIx64 |
| ") => %i", |
| (uint64_t)addr, success); |
| return success; |
| } |