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author | 2020-08-03 14:33:06 +0000 | |
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committer | 2020-08-03 14:33:06 +0000 | |
commit | 061da546b983eb767bad15e67af1174fb0bcf31c (patch) | |
tree | 83c78b820819d70aa40c36d90447978b300078c5 /gnu/llvm/lldb/source/Target/Memory.cpp | |
parent | Import LLVM 10.0.0 release including clang, lld and lldb. (diff) | |
download | wireguard-openbsd-061da546b983eb767bad15e67af1174fb0bcf31c.tar.xz wireguard-openbsd-061da546b983eb767bad15e67af1174fb0bcf31c.zip |
Import LLVM 10.0.0 release including clang, lld and lldb.
ok hackroom
tested by plenty
Diffstat (limited to 'gnu/llvm/lldb/source/Target/Memory.cpp')
-rw-r--r-- | gnu/llvm/lldb/source/Target/Memory.cpp | 414 |
1 files changed, 414 insertions, 0 deletions
diff --git a/gnu/llvm/lldb/source/Target/Memory.cpp b/gnu/llvm/lldb/source/Target/Memory.cpp new file mode 100644 index 00000000000..7c77cc06eb0 --- /dev/null +++ b/gnu/llvm/lldb/source/Target/Memory.cpp @@ -0,0 +1,414 @@ +//===-- Memory.cpp ----------------------------------------------*- C++ -*-===// +// +// 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/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() {} + +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.RemoveEntrtAtIndex(idx); + } + } + return false; +} + +size_t MemoryCache::Read(addr_t addr, void *dst, size_t dst_len, + Status &error) { + size_t bytes_left = dst_len; + + // Check the L1 cache for a range that contain the entire memory read. If we + // find a range in the L1 cache that does, we use it. Else we fall back to + // reading memory in m_L2_cache_line_byte_size byte sized chunks. The L1 + // cache contains chunks of memory that are not required to be + // m_L2_cache_line_byte_size bytes in size, so we don't try anything tricky + // when reading from them (no partial reads from the L1 cache). + + std::lock_guard<std::recursive_mutex> guard(m_mutex); + 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 this memory read request is larger than the cache line size, then we + // (1) try to read as much of it at once as possible, and (2) don't add the + // data to the memory cache. We don't want to split a big read up into more + // separate reads than necessary, and with a large memory read request, it is + // unlikely that the caller function will ask for the next + // 4 bytes after the large memory read - so there's little benefit to saving + // it in the cache. + if (dst && dst_len > m_L2_cache_line_byte_size) { + size_t bytes_read = + m_process.ReadMemoryFromInferior(addr, dst, dst_len, error); + // Add this non block sized range to the L1 cache if we actually read + // anything + if (bytes_read > 0) + AddL1CacheData(addr, dst, bytes_read); + return bytes_read; + } + + if (dst && bytes_left > 0) { + const uint32_t cache_line_byte_size = m_L2_cache_line_byte_size; + uint8_t *dst_buf = (uint8_t *)dst; + addr_t curr_addr = addr - (addr % cache_line_byte_size); + addr_t cache_offset = addr - curr_addr; + + while (bytes_left > 0) { + if (m_invalid_ranges.FindEntryThatContains(curr_addr)) { + error.SetErrorStringWithFormat("memory read failed for 0x%" PRIx64, + curr_addr); + return dst_len - bytes_left; + } + + BlockMap::const_iterator pos = m_L2_cache.find(curr_addr); + BlockMap::const_iterator end = m_L2_cache.end(); + + if (pos != end) { + size_t curr_read_size = cache_line_byte_size - cache_offset; + if (curr_read_size > bytes_left) + curr_read_size = bytes_left; + + memcpy(dst_buf + dst_len - bytes_left, + pos->second->GetBytes() + cache_offset, curr_read_size); + + bytes_left -= curr_read_size; + curr_addr += curr_read_size + cache_offset; + cache_offset = 0; + + if (bytes_left > 0) { + // Get sequential cache page hits + for (++pos; (pos != end) && (bytes_left > 0); ++pos) { + assert((curr_addr % cache_line_byte_size) == 0); + + if (pos->first != curr_addr) + break; + + curr_read_size = pos->second->GetByteSize(); + if (curr_read_size > bytes_left) + curr_read_size = bytes_left; + + memcpy(dst_buf + dst_len - bytes_left, pos->second->GetBytes(), + curr_read_size); + + bytes_left -= curr_read_size; + curr_addr += curr_read_size; + + // We have a cache page that succeeded to read some bytes but not + // an entire page. If this happens, we must cap off how much data + // we are able to read... + if (pos->second->GetByteSize() != cache_line_byte_size) + return dst_len - bytes_left; + } + } + } + + // We need to read from the process + + if (bytes_left > 0) { + assert((curr_addr % cache_line_byte_size) == 0); + std::unique_ptr<DataBufferHeap> data_buffer_heap_up( + new DataBufferHeap(cache_line_byte_size, 0)); + size_t process_bytes_read = m_process.ReadMemoryFromInferior( + curr_addr, data_buffer_heap_up->GetBytes(), + data_buffer_heap_up->GetByteSize(), error); + if (process_bytes_read == 0) + return dst_len - bytes_left; + + if (process_bytes_read != cache_line_byte_size) + data_buffer_heap_up->SetByteSize(process_bytes_read); + m_L2_cache[curr_addr] = DataBufferSP(data_buffer_heap_up.release()); + // We have read data and put it into the cache, continue through the + // loop again to get the data out of the cache... + } + } + } + + return dst_len - bytes_left; +} + +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() {} + +lldb::addr_t AllocatedBlock::ReserveBlock(uint32_t size) { + // We must return something valid for zero bytes. + if (size == 0) + size = 1; + Log *log(GetLogIfAllCategoriesSet(LIBLLDB_LOG_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(GetLogIfAllCategoriesSet(LIBLLDB_LOG_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() {} + +void AllocatedMemoryCache::Clear() { + std::lock_guard<std::recursive_mutex> guard(m_mutex); + if (m_process.IsAlive()) { + 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(GetLogIfAllCategoriesSet(LIBLLDB_LOG_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(GetLogIfAllCategoriesSet(LIBLLDB_LOG_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(GetLogIfAllCategoriesSet(LIBLLDB_LOG_PROCESS)); + LLDB_LOGF(log, + "AllocatedMemoryCache::DeallocateMemory (addr = 0x%16.16" PRIx64 + ") => %i", + (uint64_t)addr, success); + return success; +} |