remote_gdb.cc

M5,一个功能强大的多处理器系统模拟器.很多针对处理器架构,性能的研究都使用它作为模拟平台

/*
 * Copyright (c) 2002, 2003, 2004, 2005
 * The Regents of The University of Michigan
 * All Rights Reserved
 *
 * This code is part of the M5 simulator.
 *
 * Permission is granted to use, copy, create derivative works and
 * redistribute this software and such derivative works for any
 * purpose, so long as the copyright notice above, this grant of
 * permission, and the disclaimer below appear in all copies made; and
 * so long as the name of The University of Michigan is not used in
 * any advertising or publicity pertaining to the use or distribution
 * of this software without specific, written prior authorization.
 *
 * THIS SOFTWARE IS PROVIDED AS IS, WITHOUT REPRESENTATION FROM THE
 * UNIVERSITY OF MICHIGAN AS TO ITS FITNESS FOR ANY PURPOSE, AND
 * WITHOUT WARRANTY BY THE UNIVERSITY OF MICHIGAN OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE. THE REGENTS OF THE UNIVERSITY OF MICHIGAN SHALL NOT BE
 * LIABLE FOR ANY DAMAGES, INCLUDING DIRECT, SPECIAL, INDIRECT,
 * INCIDENTAL, OR CONSEQUENTIAL DAMAGES, WITH RESPECT TO ANY CLAIM
 * ARISING OUT OF OR IN CONNECTION WITH THE USE OF THE SOFTWARE, EVEN
 * IF IT HAS BEEN OR IS HEREAFTER ADVISED OF THE POSSIBILITY OF SUCH
 * DAMAGES.
 *
 * Authors: Nathan L. Binkert
 */

/*
 * Copyright (c) 1990, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * This software was developed by the Computer Systems Engineering group
 * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
 * contributed to Berkeley.
 *
 * All advertising materials mentioning features or use of this software
 * must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Lawrence Berkeley Laboratories.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. 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.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University 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 REGENTS 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 REGENTS 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.
 *
 *	@(#)kgdb_stub.c	8.4 (Berkeley) 1/12/94
 */

/*-
 * Copyright (c) 2001 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Jason R. Thorpe.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. 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.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the NetBSD
 *	Foundation, Inc. and its contributors.
 * 4. Neither the name of The NetBSD Foundation 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
 */

/*
 * $NetBSD: kgdb_stub.c,v 1.8 2001/07/07 22:58:00 wdk Exp $
 *
 * Taken from NetBSD
 *
 * "Stub" to allow remote cpu to debug over a serial line using gdb.
 */

#include <sys/signal.h>

#include <string>
#include <unistd.h>

#include "config/full_system.hh"

#if FULL_SYSTEM
#include "arch/vtophys.hh"
#endif

#include "base/intmath.hh"
#include "base/remote_gdb.hh"
#include "base/socket.hh"
#include "base/trace.hh"
#include "cpu/thread_context.hh"
#include "cpu/static_inst.hh"
//#include "mem/physical.hh"
#include "mem/port.hh"
#include "mem/translating_port.hh"
#include "sim/system.hh"

using namespace std;
using namespace TheISA;

#ifndef NDEBUG
vector<BaseRemoteGDB *> debuggers;

void
debugger()
{
    static int current_debugger = -1;
    if (current_debugger >= 0 && current_debugger < debuggers.size()) {
        BaseRemoteGDB *gdb = debuggers[current_debugger];
        if (!gdb->isattached())
            gdb->listener->accept();
        if (gdb->isattached())
            gdb->trap(SIGILL);
    }
}
#endif

///////////////////////////////////////////////////////////
//
//
//

GDBListener::Event::Event(GDBListener *l, int fd, int e)
    : PollEvent(fd, e), listener(l)
{}

void
GDBListener::Event::process(int revent)
{
    listener->accept();
}

GDBListener::GDBListener(BaseRemoteGDB *g, int p)
    : event(NULL), gdb(g), port(p)
{
    assert(!gdb->listener);
    gdb->listener = this;
}

GDBListener::~GDBListener()
{
    if (event)
        delete event;
}

string
GDBListener::name()
{
    return gdb->name() + ".listener";
}

void
GDBListener::listen()
{
    while (!listener.listen(port, true)) {
        DPRINTF(GDBMisc, "Can't bind port %d\n", port);
        port++;
    }

    event = new Event(this, listener.getfd(), POLLIN);
    pollQueue.schedule(event);

#ifndef NDEBUG
    gdb->number = debuggers.size();
    debuggers.push_back(gdb);
#endif

#ifndef NDEBUG
    ccprintf(cerr, "%d: %s: listening for remote gdb #%d on port %d\n",
             curTick, name(), gdb->number, port);
#else
    ccprintf(cerr, "%d: %s: listening for remote gdb on port %d\n",
             curTick, name(), port);
#endif
}

void
GDBListener::accept()
{
    if (!listener.islistening())
        panic("GDBListener::accept(): cannot accept if we're not listening!");

    int sfd = listener.accept(true);

    if (sfd != -1) {
        if (gdb->isattached())
            close(sfd);
        else
            gdb->attach(sfd);
    }
}

BaseRemoteGDB::Event::Event(BaseRemoteGDB *g, int fd, int e)
    : PollEvent(fd, e), gdb(g)
{}

void
BaseRemoteGDB::Event::process(int revent)
{
    if (revent & POLLIN)
        gdb->trap(SIGILL);
    else if (revent & POLLNVAL)
        gdb->detach();
}

BaseRemoteGDB::BaseRemoteGDB(System *_system, ThreadContext *c, size_t cacheSize)
    : event(NULL), listener(NULL), number(-1), fd(-1),
      active(false), attached(false),
      system(_system), pmem(_system->physmem), context(c),
      gdbregs(cacheSize)
{
    memset(gdbregs.regs, 0, gdbregs.bytes());
}

BaseRemoteGDB::~BaseRemoteGDB()
{
    if (event)
        delete event;
}

string
BaseRemoteGDB::name()
{
    return system->name() + ".remote_gdb";
}

bool
BaseRemoteGDB::isattached()
{ return attached; }

void
BaseRemoteGDB::attach(int f)
{
    fd = f;

    event = new Event(this, fd, POLLIN);
    pollQueue.schedule(event);

    attached = true;
    DPRINTFN("remote gdb attached\n");
}

void
BaseRemoteGDB::detach()
{
    attached = false;
    close(fd);
    fd = -1;

    pollQueue.remove(event);
    DPRINTFN("remote gdb detached\n");
}

const char *
BaseRemoteGDB::gdb_command(char cmd)
{
    switch (cmd) {
      case GDBSignal: return "KGDB_SIGNAL";
      case GDBSetBaud: return "KGDB_SET_BAUD";
      case GDBSetBreak: return "KGDB_SET_BREAK";
      case GDBCont: return "KGDB_CONT";
      case GDBAsyncCont: return "KGDB_ASYNC_CONT";
      case GDBDebug: return "KGDB_DEBUG";
      case GDBDetach: return "KGDB_DETACH";
      case GDBRegR: return "KGDB_REG_R";
      case GDBRegW: return "KGDB_REG_W";
      case GDBSetThread: return "KGDB_SET_THREAD";
      case GDBCycleStep: return "KGDB_CYCLE_STEP";
      case GDBSigCycleStep: return "KGDB_SIG_CYCLE_STEP";
      case GDBKill: return "KGDB_KILL";
      case GDBMemW: return "KGDB_MEM_W";
      case GDBMemR: return "KGDB_MEM_R";
      case GDBSetReg: return "KGDB_SET_REG";
      case GDBReadReg: return "KGDB_READ_REG";
      case GDBQueryVar: return "KGDB_QUERY_VAR";
      case GDBSetVar: return "KGDB_SET_VAR";
      case GDBReset: return "KGDB_RESET";
      case GDBStep: return "KGDB_STEP";
      case GDBAsyncStep: return "KGDB_ASYNC_STEP";
      case GDBThreadAlive: return "KGDB_THREAD_ALIVE";
      case GDBTargetExit: return "KGDB_TARGET_EXIT";
      case GDBBinaryDload: return "KGDB_BINARY_DLOAD";
      case GDBClrHwBkpt: return "KGDB_CLR_HW_BKPT";
      case GDBSetHwBkpt: return "KGDB_SET_HW_BKPT";
      case GDBStart: return "KGDB_START";
      case GDBEnd: return "KGDB_END";
      case GDBGoodP: return "KGDB_GOODP";
      case GDBBadP: return "KGDB_BADP";
      default: return "KGDB_UNKNOWN";
    }
}

/////////////////////////
//
//

uint8_t
BaseRemoteGDB::getbyte()
{
    uint8_t b;
    ::read(fd, &b, 1);
    return b;
}

void
BaseRemoteGDB::putbyte(uint8_t b)
{
    ::write(fd, &b, 1);
}

// Send a packet to gdb
void
BaseRemoteGDB::send(const char *bp)
{
    const char *p;
    uint8_t csum, c;

    DPRINTF(GDBSend, "send:  %s\n", bp);

    do {
        p = bp;
        //Start sending a packet
        putbyte(GDBStart);
        //Send the contents, and also keep a check sum.
        for (csum = 0; (c = *p); p++) {
            putbyte(c);
            csum += c;
        }
        //Send the ending character.
        putbyte(GDBEnd);
        //Sent the checksum.
        putbyte(i2digit(csum >> 4));
        putbyte(i2digit(csum));
        //Try transmitting over and over again until the other end doesn't send an
        //error back.
    } while ((c = getbyte() & 0x7f) == GDBBadP);
}

// Receive a packet from gdb
int
BaseRemoteGDB::recv(char *bp, int maxlen)
{
    char *p;
    int c, csum;
    int len;

    do {
        p = bp;
        csum = len = 0;
        //Find the beginning of a packet
        while ((c = getbyte()) != GDBStart)
            ;

        //Read until you find the end of the data in the packet, and keep
        //track of the check sum.
        while ((c = getbyte()) != GDBEnd && len < maxlen) {
            c &= 0x7f;
            csum += c;
            *p++ = c;
            len++;
        }

        //Mask the check sum, and terminate the command string.
        csum &= 0xff;
        *p = '\0';

        //If the command was too long, report an error.
        if (len >= maxlen) {
            putbyte(GDBBadP);
            continue;
        }

        //Bring in the checksum. If the check sum matches, csum will be 0.
        csum -= digit2i(getbyte()) * 16;
        csum -= digit2i(getbyte());

        //If the check sum was correct
        if (csum == 0) {
            //Report that the packet was received correctly
            putbyte(GDBGoodP);
            // Sequence present?
            if (bp[2] == ':') {
                putbyte(bp[0]);
                putbyte(bp[1]);
                len -= 3;
                memcpy(bp, bp+3, len);
            }
            break;
        }
        //Otherwise, report that there was a mistake.
        putbyte(GDBBadP);
    } while (1);

    DPRINTF(GDBRecv, "recv:  %s: %s\n", gdb_command(*bp), bp);

    return (len);
}

// Read bytes from kernel address space for debugger.
bool
BaseRemoteGDB::read(Addr vaddr, size_t size, char *data)
{
    static Addr lastaddr = 0;
    static size_t lastsize = 0;

    if (vaddr < 10) {
      DPRINTF(GDBRead, "read:  reading memory location zero!\n");
      vaddr = lastaddr + lastsize;
    }

    DPRINTF(GDBRead, "read:  addr=%#x, size=%d", vaddr, size);

#if FULL_SYSTEM
    VirtualPort *port = context->getVirtPort(context);
#else
    TranslatingPort *port = context->getMemPort();
#endif
    port->readBlob(vaddr, (uint8_t*)data, size);
#if FULL_SYSTEM
    context->delVirtPort(port);
#endif

#if TRACING_ON
    if (DTRACE(GDBRead)) {
        if (DTRACE(GDBExtra)) {
            char buf[1024];
            mem2hex(buf, data, size);
            DPRINTFNR(": %s\n", buf);
        } else
            DPRINTFNR("\n");
    }
#endif

    return true;
}

// Write bytes to kernel address space for debugger.
bool
BaseRemoteGDB::write(Addr vaddr, size_t size, const char *data)
{
    static Addr lastaddr = 0;
    static size_t lastsize = 0;

    if (vaddr < 10) {
      DPRINTF(GDBWrite, "write: writing memory location zero!\n");
      vaddr = lastaddr + lastsize;
    }

    if (DTRACE(GDBWrite)) {
        DPRINTFN("write: addr=%#x, size=%d", vaddr, size);
        if (DTRACE(GDBExtra)) {
            char buf[1024];
            mem2hex(buf, data, size);
            DPRINTFNR(": %s\n", buf);
        } else
            DPRINTFNR("\n");
    }
#if FULL_SYSTEM
    VirtualPort *port = context->getVirtPort(context);
#else
    TranslatingPort *port = context->getMemPort();
#endif
    port->writeBlob(vaddr, (uint8_t*)data, size);
#if FULL_SYSTEM
    context->delVirtPort(port);
#else
    delete port;
#endif