remote_gdb.hh

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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 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 "arch/types.hh"
#include "base/pollevent.hh"
#include "base/socket.hh"
#include "base/types.hh"
#include "cpu/pc_event.hh"
#include "sim/eventq.hh"
 
class System;
class ThreadContext;
 
class BaseRemoteGDB;
class HardBreakpoint;
 
class BaseGdbRegCache
{
  public:
 
    virtual char *data() const = 0;
 
    virtual size_t size() const = 0;
 
    virtual void getRegs(ThreadContext*) = 0;
 
    virtual void setRegs(ThreadContext*) const = 0;
 
    virtual const std::string name() const = 0;
 
    BaseGdbRegCache(BaseRemoteGDB *g) : gdb(g)
    {}
    virtual ~BaseGdbRegCache()
    {}
 
  protected:
    BaseRemoteGDB *gdb;
};
 
class BaseRemoteGDB
{
    friend class HardBreakpoint;
  public:
 
    BaseRemoteGDB(System *system, ThreadContext *context, 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 replaceThreadContext(ThreadContext *_tc) { tc = _tc; }
 
    bool trap(int type);
    bool breakpoint() { return trap(SIGTRAP); }
 // end of api_remote_gdb
 
  private:
    /*
     * Connection to the external GDB.
     */
    void incomingData(int revent);
    void connectWrapper(int revent) { connect(); }
 
    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::connectWrapper> ConnectEvent;
    typedef SocketEvent<&BaseRemoteGDB::incomingData> DataEvent;
 
    friend ConnectEvent;
    friend DataEvent;
 
    ConnectEvent *connectEvent;
    DataEvent *dataEvent;
 
    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);
 
    /*
     * Simulator side debugger state.
     */
    bool active;
    bool attached;
 
    System *sys;
    ThreadContext *tc;
 
    BaseGdbRegCache *regCachePtr;
 
    class TrapEvent : public Event
    {
      protected:
        int _type;
        BaseRemoteGDB *gdb;
 
      public:
        TrapEvent(BaseRemoteGDB *g) : gdb(g)
        {}
 
        void type(int t) { _type = t; }
        void process() { gdb->trap(_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();
 
    void scheduleInstCommitEvent(Event *ev, int delta);
    void descheduleInstCommitEvent(Event *ev);
 
    // Breakpoints.
    void insertSoftBreak(Addr addr, size_t len);
    void removeSoftBreak(Addr addr, size_t len);
    void insertHardBreak(Addr addr, size_t len);
    void removeHardBreak(Addr addr, size_t len);
 
    /*
     * GDB commands.
     */
    struct GdbCommand
    {
      public:
        struct Context
        {
            const GdbCommand *cmd;
            char cmd_byte;
            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> command_map;
 
    bool cmd_unsupported(GdbCommand::Context &ctx);
 
    bool cmd_signal(GdbCommand::Context &ctx);
    bool cmd_cont(GdbCommand::Context &ctx);
    bool cmd_async_cont(GdbCommand::Context &ctx);
    bool cmd_detach(GdbCommand::Context &ctx);
    bool cmd_reg_r(GdbCommand::Context &ctx);
    bool cmd_reg_w(GdbCommand::Context &ctx);
    bool cmd_set_thread(GdbCommand::Context &ctx);
    bool cmd_mem_r(GdbCommand::Context &ctx);
    bool cmd_mem_w(GdbCommand::Context &ctx);
    bool cmd_query_var(GdbCommand::Context &ctx);
    bool cmd_step(GdbCommand::Context &ctx);
    bool cmd_async_step(GdbCommand::Context &ctx);
    bool cmd_clr_hw_bkpt(GdbCommand::Context &ctx);
    bool cmd_set_hw_bkpt(GdbCommand::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;
 
    // To be implemented by subclasses.
    virtual bool checkBpLen(size_t len);
 
    virtual BaseGdbRegCache *gdbRegs() = 0;
 
    virtual bool acc(Addr addr, size_t len) = 0;
 
    virtual std::vector<std::string> availableFeatures() const;
 
    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);
}
 
#endif /* __REMOTE_GDB_H__ */