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/*
* Copyright (c) 2018 ARM Limited
*
* The license below extends only to copyright in the software and shall
* not be construed as granting a license to any other intellectual
* property including but not limited to intellectual property relating
* to a hardware implementation of the functionality of the software
* licensed hereunder. You may use the software subject to the license
* terms below provided that you ensure that this notice is replicated
* unmodified and in its entirety in all distributions of the software,
* modified or unmodified, in source code or in binary form.
*
* Copyright 2015, 2021 LabWare
* Copyright 2014 Google, Inc.
* Copyright (c) 2002-2005 The Regents of The University of Michigan
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met: redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer;
* redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution;
* neither the name of the copyright holders nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef __REMOTE_GDB_HH__
#define __REMOTE_GDB_HH__
#include <sys/signal.h>
#include <cstdint>
#include <exception>
#include <map>
#include <string>
#include <vector>
#include "arch/generic/pcstate.hh"
#include "base/cprintf.hh"
#include "base/pollevent.hh"
#include "base/socket.hh"
#include "base/types.hh"
#include "cpu/pc_event.hh"
#include "sim/debug.hh"
#include "sim/eventq.hh"
/*
* This file implements a client for the GDB remote serial protocol as
* described in this official documentation:
*
* https://sourceware.org/gdb/current/onlinedocs/gdb/Remote-Protocol.html
*/
namespace gem5
{
class System;
class ThreadContext;
class BaseRemoteGDB;
class HardBreakpoint;
/**
* Concrete subclasses of this abstract class represent how the
* register values are transmitted on the wire. Usually each
* architecture should define one subclass, but there can be more
* if there is more than one possible wire format. For example,
* ARM defines both AArch32GdbRegCache and AArch64GdbRegCache.
*/
class BaseGdbRegCache
{
public:
/**
* Return the pointer to the raw bytes buffer containing the
* register values. Each byte of this buffer is literally
* encoded as two hex digits in the g or G RSP packet.
*
* @ingroup api_remote_gdb
*/
virtual char *data() const = 0;
/**
* Return the size of the raw buffer, in bytes
* (i.e., half of the number of digits in the g/G packet).
*
* @ingroup api_remote_gdb
*/
virtual size_t size() const = 0;
/**
* Fill the raw buffer from the registers in the ThreadContext.
*
* @ingroup api_remote_gdb
*/
virtual void getRegs(ThreadContext*) = 0;
/**
* Set the ThreadContext's registers from the values
* in the raw buffer.
*
* @ingroup api_remote_gdb
*/
virtual void setRegs(ThreadContext*) const = 0;
/**
* Return the name to use in places like DPRINTF.
* Having each concrete superclass redefine this member
* is useful in situations where the class of the regCache
* can change on the fly.
*
* @ingroup api_remote_gdb
*/
virtual const std::string name() const = 0;
/**
* @ingroup api_remote_gdb
*/
BaseGdbRegCache(BaseRemoteGDB *g) : gdb(g)
{}
virtual ~BaseGdbRegCache()
{}
protected:
BaseRemoteGDB *gdb;
};
class BaseRemoteGDB
{
friend class HardBreakpoint;
public:
/**
* @ingroup api_remote_gdb
* @{
*/
/**
* Interface to other parts of the simulator.
*/
BaseRemoteGDB(System *system, int _port);
virtual ~BaseRemoteGDB();
std::string name();
void listen();
void connect();
int port() const;
void attach(int fd);
void detach();
bool isAttached() { return attached; }
void addThreadContext(ThreadContext *_tc);
void replaceThreadContext(ThreadContext *_tc);
bool selectThreadContext(ContextID id);
void trap(ContextID id, int signum);
/** @} */ // end of api_remote_gdb
template <class GDBStub, class ...Args>
static BaseRemoteGDB *
build(Args... args)
{
int port = getRemoteGDBPort();
if (port)
return new GDBStub(args..., port);
else
return nullptr;
}
private:
/*
* Connection to the external GDB.
*/
/*
* Asynchronous socket events and event handlers.
*
* These events occur asynchronously and are handled asynchronously
* to main simulation loop - therefore they *shall not* interact with
* rest of gem5.
*
* The only thing they do is to schedule a synchronous event at instruction
* boundary to deal with the request.
*/
void incomingData(int revent);
void incomingConnection(int revent);
template <void (BaseRemoteGDB::*F)(int revent)>
class SocketEvent : public PollEvent
{
protected:
BaseRemoteGDB *gdb;
public:
SocketEvent(BaseRemoteGDB *gdb, int fd, int e) :
PollEvent(fd, e), gdb(gdb)
{}
void process(int revent) { (gdb->*F)(revent); }
};
typedef SocketEvent<&BaseRemoteGDB::incomingConnection>
IncomingConnectionEvent;
typedef SocketEvent<&BaseRemoteGDB::incomingData>
IncomingDataEvent;
friend IncomingConnectionEvent;
friend IncomingDataEvent;
IncomingConnectionEvent *incomingConnectionEvent;
IncomingDataEvent *incomingDataEvent;
ListenSocket listener;
int _port;
// The socket commands come in through.
int fd;
// Transfer data to/from GDB.
uint8_t getbyte();
void putbyte(uint8_t b);
void recv(std::vector<char> &bp);
void send(const char *data);
void send(const std::string &data) { send(data.c_str()); }
template <typename ...Args>
void
send(const char *format, const Args &...args)
{
send(csprintf(format, args...));
}
/*
* Process commands from remote GDB. If simulation has been
* stopped because of some kind of fault (as segmentation violation,
* or SW trap), 'signum' is the signal value reported back to GDB
* in "S" packet (this is done in trap()).
*/
void processCommands(int signum=0);
/*
* Simulator side debugger state.
*/
bool attached = false;
bool threadSwitching = false;
System *sys;
std::map<ContextID, ThreadContext *> threads;
ThreadContext *tc = nullptr;
BaseGdbRegCache *regCachePtr = nullptr;
EventWrapper<BaseRemoteGDB, &BaseRemoteGDB::connect> connectEvent;
EventWrapper<BaseRemoteGDB, &BaseRemoteGDB::detach> disconnectEvent;
class TrapEvent : public Event
{
protected:
int _type;
ContextID _id;
BaseRemoteGDB *gdb;
public:
TrapEvent(BaseRemoteGDB *g) : gdb(g)
{}
void type(int t) { _type = t; }
void id(ContextID id) { _id = id; }
void process() { gdb->trap(_id, _type); }
} trapEvent;
/*
* The interface to the simulated system.
*/
// Machine memory.
bool read(Addr addr, size_t size, char *data);
bool write(Addr addr, size_t size, const char *data);
template <class T> T read(Addr addr);
template <class T> void write(Addr addr, T data);
// Single step.
void singleStep();
EventWrapper<BaseRemoteGDB, &BaseRemoteGDB::singleStep> singleStepEvent;
void clearSingleStep();
void setSingleStep();
/// Schedule an event which will be triggered "delta" instructions later.
void scheduleInstCommitEvent(Event *ev, int delta);
/// Deschedule an instruction count based event.
void descheduleInstCommitEvent(Event *ev);
// Breakpoints.
void insertSoftBreak(Addr addr, size_t kind);
void removeSoftBreak(Addr addr, size_t kind);
void insertHardBreak(Addr addr, size_t kind);
void removeHardBreak(Addr addr, size_t kind);
/*
* GDB commands.
*/
struct GdbCommand
{
public:
struct Context
{
const GdbCommand *cmd;
char cmdByte;
int type;
char *data;
int len;
};
typedef bool (BaseRemoteGDB::*Func)(Context &ctx);
const char * const name;
const Func func;
GdbCommand(const char *_name, Func _func) : name(_name), func(_func) {}
};
static std::map<char, GdbCommand> commandMap;
bool cmdUnsupported(GdbCommand::Context &ctx);
bool cmdSignal(GdbCommand::Context &ctx);
bool cmdCont(GdbCommand::Context &ctx);
bool cmdAsyncCont(GdbCommand::Context &ctx);
bool cmdDetach(GdbCommand::Context &ctx);
bool cmdRegR(GdbCommand::Context &ctx);
bool cmdRegW(GdbCommand::Context &ctx);
bool cmdSetThread(GdbCommand::Context &ctx);
bool cmdMemR(GdbCommand::Context &ctx);
bool cmdMemW(GdbCommand::Context &ctx);
bool cmdQueryVar(GdbCommand::Context &ctx);
bool cmdStep(GdbCommand::Context &ctx);
bool cmdAsyncStep(GdbCommand::Context &ctx);
bool cmdClrHwBkpt(GdbCommand::Context &ctx);
bool cmdSetHwBkpt(GdbCommand::Context &ctx);
bool cmdDumpPageTable(GdbCommand::Context &ctx);
struct QuerySetCommand
{
struct Context
{
const std::string &name;
std::vector<std::string> args;
Context(const std::string &_name) : name(_name) {}
};
using Func = void (BaseRemoteGDB::*)(Context &ctx);
const char * const argSep;
const Func func;
QuerySetCommand(Func _func, const char *_argSep=nullptr) :
argSep(_argSep), func(_func)
{}
};
static std::map<std::string, QuerySetCommand> queryMap;
void queryC(QuerySetCommand::Context &ctx);
void querySupported(QuerySetCommand::Context &ctx);
void queryXfer(QuerySetCommand::Context &ctx);
size_t threadInfoIdx = 0;
void queryFThreadInfo(QuerySetCommand::Context &ctx);
void querySThreadInfo(QuerySetCommand::Context &ctx);
protected:
ThreadContext *context() { return tc; }
System *system() { return sys; }
void encodeBinaryData(const std::string &unencoded,
std::string &encoded) const;
void encodeXferResponse(const std::string &unencoded,
std::string &encoded, size_t offset, size_t unencoded_length) const;
// checkBpKind checks if a kind of breakpoint is legal. This function should
// be implemented by subclasses by arch. The "kind" is considered to be
// breakpoint size in some arch.
virtual bool checkBpKind(size_t kind);
virtual BaseGdbRegCache *gdbRegs() = 0;
virtual bool acc(Addr addr, size_t len) = 0;
virtual std::vector<std::string> availableFeatures() const;
/**
* Get an XML target description.
*
* @param[in] annex the XML filename
* @param[out] output set to the decoded XML
* @return true if the given annex was found
*/
virtual bool getXferFeaturesRead(const std::string &annex,
std::string &output);
};
template <class T>
inline T
BaseRemoteGDB::read(Addr addr)
{
T temp;
read(addr, sizeof(T), (char *)&temp);
return temp;
}
template <class T>
inline void
BaseRemoteGDB::write(Addr addr, T data)
{
write(addr, sizeof(T), (const char *)&data);
}
} // namespace gem5
#endif /* __REMOTE_GDB_H__ */