gem5/src/base/remote_gdb.hh
Gabe Black 4a8a0a0798 misc: Generalize GDB single stepping.
The new single stepping implementation for x86 doesn't rely on any ISA
specific properties or functionality. This change pulls out the per ISA
implementation of those functions and promotes the X86 implementation to the
base class.

One drawback of that implementation is that the CPU might stop on an
instruction twice if it's affected by both breakpoints and single stepping.
While that might be a little surprising, it's harmless and would only happen
under somewhat unlikely circumstances.
2014-12-05 22:37:03 -08:00

321 lines
8.5 KiB
C++

/*
* 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.
*
* Authors: Nathan Binkert
*/
#ifndef __REMOTE_GDB_HH__
#define __REMOTE_GDB_HH__
#include <sys/signal.h>
#include <map>
#include "arch/types.hh"
#include "base/intmath.hh"
#include "base/pollevent.hh"
#include "base/socket.hh"
#include "cpu/pc_event.hh"
class System;
class ThreadContext;
class GDBListener;
enum GDBCommands
{
GDBSignal = '?', // last signal
GDBSetBaud = 'b', // set baud (depracated)
GDBSetBreak = 'B', // set breakpoint (depracated)
GDBCont = 'c', // resume
GDBAsyncCont = 'C', // continue with signal
GDBDebug = 'd', // toggle debug flags (deprecated)
GDBDetach = 'D', // detach remote gdb
GDBRegR = 'g', // read general registers
GDBRegW = 'G', // write general registers
GDBSetThread = 'H', // set thread
GDBCycleStep = 'i', // step a single cycle
GDBSigCycleStep = 'I', // signal then cycle step
GDBKill = 'k', // kill program
GDBMemR = 'm', // read memory
GDBMemW = 'M', // write memory
GDBReadReg = 'p', // read register
GDBSetReg = 'P', // write register
GDBQueryVar = 'q', // query variable
GDBSetVar = 'Q', // set variable
GDBReset = 'r', // reset system. (Deprecated)
GDBStep = 's', // step
GDBAsyncStep = 'S', // signal and step
GDBThreadAlive = 'T', // find out if the thread is alive
GDBTargetExit = 'W', // target exited
GDBBinaryDload = 'X', // write memory
GDBClrHwBkpt = 'z', // remove breakpoint or watchpoint
GDBSetHwBkpt = 'Z' // insert breakpoint or watchpoint
};
const char GDBStart = '$';
const char GDBEnd = '#';
const char GDBGoodP = '+';
const char GDBBadP = '-';
const int GDBPacketBufLen = 1024;
class BaseRemoteGDB
{
private:
friend void debugger();
friend class GDBListener;
//Helper functions
protected:
int digit2i(char);
char i2digit(int);
Addr hex2i(const char **);
//Address formats, break types, and gdb commands may change
//between architectures, so they're defined as virtual
//functions.
virtual void mem2hex(void *, const void *, int);
virtual const char * hex2mem(void *, const char *, int);
virtual const char * break_type(char c);
virtual const char * gdb_command(char cmd);
protected:
class InputEvent : public PollEvent
{
protected:
BaseRemoteGDB *gdb;
public:
InputEvent(BaseRemoteGDB *g, int fd, int e);
void process(int revent);
};
class TrapEvent : public Event
{
protected:
int _type;
BaseRemoteGDB *gdb;
public:
TrapEvent(BaseRemoteGDB *g) : gdb(g)
{}
void type(int t) { _type = t; }
void process();
};
friend class InputEvent;
InputEvent *inputEvent;
TrapEvent trapEvent;
GDBListener *listener;
int number;
protected:
//The socket commands come in through
int fd;
protected:
#ifdef notyet
label_t recover;
#endif
bool active;
bool attached;
System *system;
ThreadContext *context;
protected:
class GdbRegCache
{
public:
GdbRegCache(size_t newSize) :
regs64(new uint64_t[divCeil(newSize, sizeof(uint64_t))]),
size(newSize)
{}
~GdbRegCache()
{
delete [] regs64;
}
union {
uint64_t *regs64;
uint32_t *regs32;
uint16_t *regs16;
uint8_t *regs8;
void *regs;
};
// Size of cache in bytes.
size_t size;
size_t bytes() { return size; }
};
GdbRegCache gdbregs;
protected:
uint8_t getbyte();
void putbyte(uint8_t b);
int recv(char *data, int len);
void send(const char *data);
protected:
// Machine memory
virtual bool read(Addr addr, size_t size, char *data);
virtual 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);
public:
BaseRemoteGDB(System *system, ThreadContext *context, size_t cacheSize);
virtual ~BaseRemoteGDB();
void replaceThreadContext(ThreadContext *tc) { context = tc; }
void attach(int fd);
void detach();
bool isattached();
virtual bool acc(Addr addr, size_t len) = 0;
bool trap(int type);
virtual bool breakpoint()
{
return trap(SIGTRAP);
}
protected:
class SingleStepEvent : public Event
{
protected:
BaseRemoteGDB *gdb;
public:
SingleStepEvent(BaseRemoteGDB *g) : gdb(g)
{}
void process();
};
SingleStepEvent singleStepEvent;
virtual void getregs() = 0;
virtual void setregs() = 0;
void clearSingleStep();
void setSingleStep();
PCEventQueue *getPcEventQueue();
EventQueue *getComInstEventQueue();
/// 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);
protected:
virtual bool checkBpLen(size_t len);
class HardBreakpoint : public PCEvent
{
private:
BaseRemoteGDB *gdb;
public:
int refcount;
public:
HardBreakpoint(BaseRemoteGDB *_gdb, Addr addr);
const std::string name() const { return gdb->name() + ".hwbkpt"; }
virtual void process(ThreadContext *tc);
};
friend class HardBreakpoint;
typedef std::map<Addr, HardBreakpoint *> break_map_t;
typedef break_map_t::iterator break_iter_t;
break_map_t hardBreakMap;
bool insertSoftBreak(Addr addr, size_t len);
bool removeSoftBreak(Addr addr, size_t len);
virtual bool insertHardBreak(Addr addr, size_t len);
bool removeHardBreak(Addr addr, size_t len);
protected:
void clearTempBreakpoint(Addr &bkpt);
void setTempBreakpoint(Addr bkpt);
public:
std::string name();
};
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); }
class GDBListener
{
protected:
class InputEvent : public PollEvent
{
protected:
GDBListener *listener;
public:
InputEvent(GDBListener *l, int fd, int e);
void process(int revent);
};
friend class InputEvent;
InputEvent *inputEvent;
protected:
ListenSocket listener;
BaseRemoteGDB *gdb;
int port;
public:
GDBListener(BaseRemoteGDB *g, int p);
~GDBListener();
void accept();
void listen();
std::string name();
};
#endif /* __REMOTE_GDB_H__ */