Files
clang-p2996/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.h
David Spickett da2e614f56 [lldb][AArch64] Add memory tag reading to lldb-server
This adds memory tag reading using the new "qMemTags"
packet and ptrace on AArch64 Linux.

This new packet is following the one used by GDB.
(https://sourceware.org/gdb/current/onlinedocs/gdb/General-Query-Packets.html)

On AArch64 Linux we use ptrace's PEEKMTETAGS to read
tags and we assume that lldb has already checked that the
memory region actually has tagging enabled.

We do not assume that lldb has expanded the requested range
to granules and expand it again to be sure.
(although lldb will be sending aligned ranges because it happens
to need them client side anyway)
Also we don't assume untagged addresses. So for AArch64 we'll
remove the top byte before using them. (the top byte includes
MTE and other non address data)

To do the ptrace read NativeProcessLinux will ask the native
register context for a memory tag manager based on the
type in the packet. This also gives you the ptrace numbers you need.
(it's called a register context but it also has non register data,
so it saves adding another per platform sub class)

The only supported platform for this is AArch64 Linux and the only
supported tag type is MTE allocation tags. Anything else will
error.

Ptrace can return a partial result but for lldb-server we will
be treating that as an error. To succeed we need to get all the tags
we expect.

(Note that the protocol leaves room for logical tags to be
read via qMemTags but this is not going to be implemented for lldb
at this time.)

Reviewed By: omjavaid

Differential Revision: https://reviews.llvm.org/D95601
2021-06-24 17:02:55 +01:00

290 lines
9.8 KiB
C++

//===-- GDBRemoteCommunicationServerLLGS.h ----------------------*- 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
//
//===----------------------------------------------------------------------===//
#ifndef LLDB_SOURCE_PLUGINS_PROCESS_GDB_REMOTE_GDBREMOTECOMMUNICATIONSERVERLLGS_H
#define LLDB_SOURCE_PLUGINS_PROCESS_GDB_REMOTE_GDBREMOTECOMMUNICATIONSERVERLLGS_H
#include <mutex>
#include <unordered_map>
#include "lldb/Core/Communication.h"
#include "lldb/Host/MainLoop.h"
#include "lldb/Host/common/NativeProcessProtocol.h"
#include "lldb/lldb-private-forward.h"
#include "GDBRemoteCommunicationServerCommon.h"
class StringExtractorGDBRemote;
namespace lldb_private {
namespace process_gdb_remote {
class ProcessGDBRemote;
class GDBRemoteCommunicationServerLLGS
: public GDBRemoteCommunicationServerCommon,
public NativeProcessProtocol::NativeDelegate {
public:
// Constructors and Destructors
GDBRemoteCommunicationServerLLGS(
MainLoop &mainloop,
const NativeProcessProtocol::Factory &process_factory);
void SetLaunchInfo(const ProcessLaunchInfo &info);
/// Launch a process with the current launch settings.
///
/// This method supports running an lldb-gdbserver or similar
/// server in a situation where the startup code has been provided
/// with all the information for a child process to be launched.
///
/// \return
/// An Status object indicating the success or failure of the
/// launch.
Status LaunchProcess() override;
/// Attach to a process.
///
/// This method supports attaching llgs to a process accessible via the
/// configured Platform.
///
/// \return
/// An Status object indicating the success or failure of the
/// attach operation.
Status AttachToProcess(lldb::pid_t pid);
/// Wait to attach to a process with a given name.
///
/// This method supports waiting for the next instance of a process
/// with a given name and attaching llgs to that via the configured
/// Platform.
///
/// \return
/// An Status object indicating the success or failure of the
/// attach operation.
Status AttachWaitProcess(llvm::StringRef process_name, bool include_existing);
// NativeProcessProtocol::NativeDelegate overrides
void InitializeDelegate(NativeProcessProtocol *process) override;
void ProcessStateChanged(NativeProcessProtocol *process,
lldb::StateType state) override;
void DidExec(NativeProcessProtocol *process) override;
void
NewSubprocess(NativeProcessProtocol *parent_process,
std::unique_ptr<NativeProcessProtocol> child_process) override;
Status InitializeConnection(std::unique_ptr<Connection> connection);
protected:
MainLoop &m_mainloop;
MainLoop::ReadHandleUP m_network_handle_up;
const NativeProcessProtocol::Factory &m_process_factory;
lldb::tid_t m_current_tid = LLDB_INVALID_THREAD_ID;
lldb::tid_t m_continue_tid = LLDB_INVALID_THREAD_ID;
NativeProcessProtocol *m_current_process;
NativeProcessProtocol *m_continue_process;
std::recursive_mutex m_debugged_process_mutex;
std::unordered_map<lldb::pid_t, std::unique_ptr<NativeProcessProtocol>>
m_debugged_processes;
Communication m_stdio_communication;
MainLoop::ReadHandleUP m_stdio_handle_up;
lldb::StateType m_inferior_prev_state = lldb::StateType::eStateInvalid;
llvm::StringMap<std::unique_ptr<llvm::MemoryBuffer>> m_xfer_buffer_map;
std::mutex m_saved_registers_mutex;
std::unordered_map<uint32_t, lldb::DataBufferSP> m_saved_registers_map;
uint32_t m_next_saved_registers_id = 1;
bool m_handshake_completed = false;
bool m_thread_suffix_supported = false;
bool m_list_threads_in_stop_reply = false;
NativeProcessProtocol::Extension m_extensions_supported = {};
PacketResult SendONotification(const char *buffer, uint32_t len);
PacketResult SendWResponse(NativeProcessProtocol *process);
PacketResult SendStopReplyPacketForThread(lldb::tid_t tid);
PacketResult SendStopReasonForState(lldb::StateType process_state);
PacketResult Handle_k(StringExtractorGDBRemote &packet);
PacketResult Handle_qProcessInfo(StringExtractorGDBRemote &packet);
PacketResult Handle_qC(StringExtractorGDBRemote &packet);
PacketResult Handle_QSetDisableASLR(StringExtractorGDBRemote &packet);
PacketResult Handle_QSetWorkingDir(StringExtractorGDBRemote &packet);
PacketResult Handle_qGetWorkingDir(StringExtractorGDBRemote &packet);
PacketResult Handle_QThreadSuffixSupported(StringExtractorGDBRemote &packet);
PacketResult Handle_QListThreadsInStopReply(StringExtractorGDBRemote &packet);
PacketResult Handle_C(StringExtractorGDBRemote &packet);
PacketResult Handle_c(StringExtractorGDBRemote &packet);
PacketResult Handle_vCont(StringExtractorGDBRemote &packet);
PacketResult Handle_vCont_actions(StringExtractorGDBRemote &packet);
PacketResult Handle_stop_reason(StringExtractorGDBRemote &packet);
PacketResult Handle_qRegisterInfo(StringExtractorGDBRemote &packet);
PacketResult Handle_qfThreadInfo(StringExtractorGDBRemote &packet);
PacketResult Handle_qsThreadInfo(StringExtractorGDBRemote &packet);
PacketResult Handle_p(StringExtractorGDBRemote &packet);
PacketResult Handle_P(StringExtractorGDBRemote &packet);
PacketResult Handle_H(StringExtractorGDBRemote &packet);
PacketResult Handle_I(StringExtractorGDBRemote &packet);
PacketResult Handle_interrupt(StringExtractorGDBRemote &packet);
// Handles $m and $x packets.
PacketResult Handle_memory_read(StringExtractorGDBRemote &packet);
PacketResult Handle_M(StringExtractorGDBRemote &packet);
PacketResult Handle__M(StringExtractorGDBRemote &packet);
PacketResult Handle__m(StringExtractorGDBRemote &packet);
PacketResult
Handle_qMemoryRegionInfoSupported(StringExtractorGDBRemote &packet);
PacketResult Handle_qMemoryRegionInfo(StringExtractorGDBRemote &packet);
PacketResult Handle_Z(StringExtractorGDBRemote &packet);
PacketResult Handle_z(StringExtractorGDBRemote &packet);
PacketResult Handle_s(StringExtractorGDBRemote &packet);
PacketResult Handle_qXfer(StringExtractorGDBRemote &packet);
PacketResult Handle_QSaveRegisterState(StringExtractorGDBRemote &packet);
PacketResult Handle_jLLDBTraceSupported(StringExtractorGDBRemote &packet);
PacketResult Handle_jLLDBTraceStart(StringExtractorGDBRemote &packet);
PacketResult Handle_jLLDBTraceStop(StringExtractorGDBRemote &packet);
PacketResult Handle_jLLDBTraceGetState(StringExtractorGDBRemote &packet);
PacketResult Handle_jLLDBTraceGetBinaryData(StringExtractorGDBRemote &packet);
PacketResult Handle_QRestoreRegisterState(StringExtractorGDBRemote &packet);
PacketResult Handle_vAttach(StringExtractorGDBRemote &packet);
PacketResult Handle_vAttachWait(StringExtractorGDBRemote &packet);
PacketResult Handle_qVAttachOrWaitSupported(StringExtractorGDBRemote &packet);
PacketResult Handle_vAttachOrWait(StringExtractorGDBRemote &packet);
PacketResult Handle_D(StringExtractorGDBRemote &packet);
PacketResult Handle_qThreadStopInfo(StringExtractorGDBRemote &packet);
PacketResult Handle_jThreadsInfo(StringExtractorGDBRemote &packet);
PacketResult Handle_qWatchpointSupportInfo(StringExtractorGDBRemote &packet);
PacketResult Handle_qFileLoadAddress(StringExtractorGDBRemote &packet);
PacketResult Handle_QPassSignals(StringExtractorGDBRemote &packet);
PacketResult Handle_g(StringExtractorGDBRemote &packet);
PacketResult Handle_qMemTags(StringExtractorGDBRemote &packet);
void SetCurrentThreadID(lldb::tid_t tid);
lldb::tid_t GetCurrentThreadID() const;
void SetContinueThreadID(lldb::tid_t tid);
lldb::tid_t GetContinueThreadID() const { return m_continue_tid; }
Status SetSTDIOFileDescriptor(int fd);
FileSpec FindModuleFile(const std::string &module_path,
const ArchSpec &arch) override;
llvm::Expected<std::unique_ptr<llvm::MemoryBuffer>>
ReadXferObject(llvm::StringRef object, llvm::StringRef annex);
static std::string XMLEncodeAttributeValue(llvm::StringRef value);
virtual std::vector<std::string> HandleFeatures(
const llvm::ArrayRef<llvm::StringRef> client_features) override;
private:
llvm::Expected<std::unique_ptr<llvm::MemoryBuffer>> BuildTargetXml();
void HandleInferiorState_Exited(NativeProcessProtocol *process);
void HandleInferiorState_Stopped(NativeProcessProtocol *process);
NativeThreadProtocol *GetThreadFromSuffix(StringExtractorGDBRemote &packet);
uint32_t GetNextSavedRegistersID();
void MaybeCloseInferiorTerminalConnection();
void ClearProcessSpecificData();
void RegisterPacketHandlers();
void DataAvailableCallback();
void SendProcessOutput();
void StartSTDIOForwarding();
void StopSTDIOForwarding();
// Read thread-id from packet. If the thread-id is correct, returns it.
// Otherwise, returns the error.
//
// If allow_all is true, then the pid/tid value of -1 ('all') will be allowed.
// In any case, the function assumes that exactly one inferior is being
// debugged and rejects pid values that do no match that inferior.
llvm::Expected<lldb::tid_t> ReadTid(StringExtractorGDBRemote &packet,
bool allow_all, lldb::pid_t default_pid);
// Call SetEnabledExtensions() with appropriate flags on the process.
void SetEnabledExtensions(NativeProcessProtocol &process);
// For GDBRemoteCommunicationServerLLGS only
GDBRemoteCommunicationServerLLGS(const GDBRemoteCommunicationServerLLGS &) =
delete;
const GDBRemoteCommunicationServerLLGS &
operator=(const GDBRemoteCommunicationServerLLGS &) = delete;
};
} // namespace process_gdb_remote
} // namespace lldb_private
#endif // LLDB_SOURCE_PLUGINS_PROCESS_GDB_REMOTE_GDBREMOTECOMMUNICATIONSERVERLLGS_H