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authorpatrick <patrick@openbsd.org>2020-08-03 14:33:06 +0000
committerpatrick <patrick@openbsd.org>2020-08-03 14:33:06 +0000
commit061da546b983eb767bad15e67af1174fb0bcf31c (patch)
tree83c78b820819d70aa40c36d90447978b300078c5 /gnu/llvm/lldb/source/Target/Memory.cpp
parentImport LLVM 10.0.0 release including clang, lld and lldb. (diff)
downloadwireguard-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.cpp414
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;
+}