remote_gdb.cc revision 12019:65939e37768a 
1/*
2 * Copyright 2015 LabWare
3 * Copyright 2014 Google, Inc.
4 * Copyright (c) 2002-2005 The Regents of The University of Michigan
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions are
9 * met: redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer;
11 * redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution;
14 * neither the name of the copyright holders nor the names of its
15 * contributors may be used to endorse or promote products derived from
16 * this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
22 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
23 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
24 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
28 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 *
30 * Authors: Nathan Binkert
31 *          Boris Shingarov
32 */
33
34/*
35 * Copyright (c) 1990, 1993 The Regents of the University of California
36 * All rights reserved
37 *
38 * This software was developed by the Computer Systems Engineering group
39 * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
40 * contributed to Berkeley.
41 *
42 * All advertising materials mentioning features or use of this software
43 * must display the following acknowledgement:
44 *      This product includes software developed by the University of
45 *      California, Lawrence Berkeley Laboratories.
46 *
47 * Redistribution and use in source and binary forms, with or without
48 * modification, are permitted provided that the following conditions
49 * are met:
50 * 1. Redistributions of source code must retain the above copyright
51 *    notice, this list of conditions and the following disclaimer.
52 * 2. Redistributions in binary form must reproduce the above copyright
53 *    notice, this list of conditions and the following disclaimer in the
54 *    documentation and/or other materials provided with the distribution.
55 * 3. All advertising materials mentioning features or use of this software
56 *    must display the following acknowledgement:
57 *      This product includes software developed by the University of
58 *      California, Berkeley and its contributors.
59 * 4. Neither the name of the University nor the names of its contributors
60 *    may be used to endorse or promote products derived from this software
61 *    without specific prior written permission.
62 *
63 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
64 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
65 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
66 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
67 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
68 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
69 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
70 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
71 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
72 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
73 * SUCH DAMAGE.
74 *
75 *      @(#)kgdb_stub.c 8.4 (Berkeley) 1/12/94
76 */
77
78/*-
79 * Copyright (c) 2001 The NetBSD Foundation, Inc.
80 * All rights reserved.
81 *
82 * This code is derived from software contributed to The NetBSD Foundation
83 * by Jason R. Thorpe.
84 *
85 * Redistribution and use in source and binary forms, with or without
86 * modification, are permitted provided that the following conditions
87 * are met:
88 * 1. Redistributions of source code must retain the above copyright
89 *    notice, this list of conditions and the following disclaimer.
90 * 2. Redistributions in binary form must reproduce the above copyright
91 *    notice, this list of conditions and the following disclaimer in the
92 *    documentation and/or other materials provided with the distribution.
93 * 3. All advertising materials mentioning features or use of this software
94 *    must display the following acknowledgement:
95 *      This product includes software developed by the NetBSD
96 *      Foundation, Inc. and its contributors.
97 * 4. Neither the name of The NetBSD Foundation nor the names of its
98 *    contributors may be used to endorse or promote products derived
99 *    from this software without specific prior written permission.
100 *
101 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
102 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
103 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
104 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
105 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
106 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
107 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
108 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
109 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
110 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
111 * POSSIBILITY OF SUCH DAMAGE.
112 */
113
114/*
115 * $NetBSD: kgdb_stub.c,v 1.8 2001/07/07 22:58:00 wdk Exp $
116 *
117 * Taken from NetBSD
118 *
119 * "Stub" to allow remote cpu to debug over a serial line using gdb.
120 */
121
122#include "base/remote_gdb.hh"
123
124#include <sys/signal.h>
125#include <unistd.h>
126
127#include <csignal>
128#include <cstdint>
129#include <cstdio>
130#include <string>
131
132#include "arch/vtophys.hh"
133#include "base/intmath.hh"
134#include "base/socket.hh"
135#include "base/trace.hh"
136#include "config/the_isa.hh"
137#include "cpu/base.hh"
138#include "cpu/static_inst.hh"
139#include "cpu/thread_context.hh"
140#include "debug/GDBAll.hh"
141#include "mem/fs_translating_port_proxy.hh"
142#include "mem/port.hh"
143#include "mem/se_translating_port_proxy.hh"
144#include "sim/full_system.hh"
145#include "sim/system.hh"
146
147using namespace std;
148using namespace TheISA;
149
150#ifndef NDEBUG
151vector<BaseRemoteGDB *> debuggers;
152
153void
154debugger()
155{
156    static int current_debugger = -1;
157    if (current_debugger >= 0 && current_debugger < (int)debuggers.size()) {
158        BaseRemoteGDB *gdb = debuggers[current_debugger];
159        if (!gdb->isattached())
160            gdb->listener->accept();
161        if (gdb->isattached())
162            gdb->trap(SIGILL);
163    }
164}
165#endif
166
167///////////////////////////////////////////////////////////
168//
169//
170//
171
172GDBListener::InputEvent::InputEvent(GDBListener *l, int fd, int e)
173    : PollEvent(fd, e), listener(l)
174{}
175
176void
177GDBListener::InputEvent::process(int revent)
178{
179    listener->accept();
180}
181
182GDBListener::GDBListener(BaseRemoteGDB *g, int p)
183    : inputEvent(NULL), gdb(g), port(p)
184{
185    assert(!gdb->listener);
186    gdb->listener = this;
187}
188
189GDBListener::~GDBListener()
190{
191    if (inputEvent)
192        delete inputEvent;
193}
194
195string
196GDBListener::name()
197{
198    return gdb->name() + ".listener";
199}
200
201void
202GDBListener::listen()
203{
204    if (ListenSocket::allDisabled()) {
205        warn_once("Sockets disabled, not accepting gdb connections");
206        return;
207    }
208
209    while (!listener.listen(port, true)) {
210        DPRINTF(GDBMisc, "Can't bind port %d\n", port);
211        port++;
212    }
213
214    inputEvent = new InputEvent(this, listener.getfd(), POLLIN);
215    pollQueue.schedule(inputEvent);
216
217#ifndef NDEBUG
218    gdb->number = debuggers.size();
219    debuggers.push_back(gdb);
220#endif
221
222#ifndef NDEBUG
223    ccprintf(cerr, "%d: %s: listening for remote gdb #%d on port %d\n",
224             curTick(), name(), gdb->number, port);
225#else
226    ccprintf(cerr, "%d: %s: listening for remote gdb on port %d\n",
227             curTick(), name(), port);
228#endif
229}
230
231void
232GDBListener::accept()
233{
234    if (!listener.islistening())
235        panic("GDBListener::accept(): cannot accept if we're not listening!");
236
237    int sfd = listener.accept(true);
238
239    if (sfd != -1) {
240        if (gdb->isattached())
241            close(sfd);
242        else
243            gdb->attach(sfd);
244    }
245}
246
247BaseRemoteGDB::InputEvent::InputEvent(BaseRemoteGDB *g, int fd, int e)
248    : PollEvent(fd, e), gdb(g)
249{}
250
251void
252BaseRemoteGDB::InputEvent::process(int revent)
253{
254    if (gdb->trapEvent.scheduled()) {
255        warn("GDB trap event has already been scheduled! "
256             "Ignoring this input event.");
257        return;
258    }
259
260    if (revent & POLLIN) {
261        gdb->trapEvent.type(SIGILL);
262        gdb->scheduleInstCommitEvent(&gdb->trapEvent, 0);
263    } else if (revent & POLLNVAL) {
264        gdb->descheduleInstCommitEvent(&gdb->trapEvent);
265        gdb->detach();
266    }
267}
268
269void
270BaseRemoteGDB::TrapEvent::process()
271{
272    gdb->trap(_type);
273}
274
275void
276BaseRemoteGDB::SingleStepEvent::process()
277{
278    if (!gdb->singleStepEvent.scheduled())
279        gdb->scheduleInstCommitEvent(&gdb->singleStepEvent, 1);
280    gdb->trap(SIGTRAP);
281}
282
283BaseRemoteGDB::BaseRemoteGDB(System *_system, ThreadContext *c) :
284        inputEvent(NULL), trapEvent(this), listener(NULL),
285        number(-1), fd(-1), active(false), attached(false), system(_system),
286        context(c), singleStepEvent(this)
287{
288}
289
290BaseRemoteGDB::~BaseRemoteGDB()
291{
292    if (inputEvent)
293        delete inputEvent;
294}
295
296string
297BaseRemoteGDB::name()
298{
299    return system->name() + ".remote_gdb";
300}
301
302bool
303BaseRemoteGDB::isattached()
304{ return attached; }
305
306void
307BaseRemoteGDB::attach(int f)
308{
309    fd = f;
310
311    inputEvent = new InputEvent(this, fd, POLLIN);
312    pollQueue.schedule(inputEvent);
313
314    attached = true;
315    DPRINTFN("remote gdb attached\n");
316}
317
318void
319BaseRemoteGDB::detach()
320{
321    attached = false;
322    close(fd);
323    fd = -1;
324
325    pollQueue.remove(inputEvent);
326    DPRINTFN("remote gdb detached\n");
327}
328
329const char *
330BaseRemoteGDB::gdb_command(char cmd)
331{
332    switch (cmd) {
333      case GDBSignal: return "KGDB_SIGNAL";
334      case GDBSetBaud: return "KGDB_SET_BAUD";
335      case GDBSetBreak: return "KGDB_SET_BREAK";
336      case GDBCont: return "KGDB_CONT";
337      case GDBAsyncCont: return "KGDB_ASYNC_CONT";
338      case GDBDebug: return "KGDB_DEBUG";
339      case GDBDetach: return "KGDB_DETACH";
340      case GDBRegR: return "KGDB_REG_R";
341      case GDBRegW: return "KGDB_REG_W";
342      case GDBSetThread: return "KGDB_SET_THREAD";
343      case GDBCycleStep: return "KGDB_CYCLE_STEP";
344      case GDBSigCycleStep: return "KGDB_SIG_CYCLE_STEP";
345      case GDBKill: return "KGDB_KILL";
346      case GDBMemW: return "KGDB_MEM_W";
347      case GDBMemR: return "KGDB_MEM_R";
348      case GDBSetReg: return "KGDB_SET_REG";
349      case GDBReadReg: return "KGDB_READ_REG";
350      case GDBQueryVar: return "KGDB_QUERY_VAR";
351      case GDBSetVar: return "KGDB_SET_VAR";
352      case GDBReset: return "KGDB_RESET";
353      case GDBStep: return "KGDB_STEP";
354      case GDBAsyncStep: return "KGDB_ASYNC_STEP";
355      case GDBThreadAlive: return "KGDB_THREAD_ALIVE";
356      case GDBTargetExit: return "KGDB_TARGET_EXIT";
357      case GDBBinaryDload: return "KGDB_BINARY_DLOAD";
358      case GDBClrHwBkpt: return "KGDB_CLR_HW_BKPT";
359      case GDBSetHwBkpt: return "KGDB_SET_HW_BKPT";
360      case GDBStart: return "KGDB_START";
361      case GDBEnd: return "KGDB_END";
362      case GDBGoodP: return "KGDB_GOODP";
363      case GDBBadP: return "KGDB_BADP";
364      default: return "KGDB_UNKNOWN";
365    }
366}
367
368/////////////////////////
369//
370//
371
372bool
373BaseRemoteGDB::getbyte(uint8_t &b)
374{
375    if (::read(fd, &b, sizeof(b)) == sizeof(b)) {
376        return true;
377    } else {
378        warn("Couldn't read data from debugger, detaching.");
379        detach();
380        return false;
381    }
382}
383
384bool
385BaseRemoteGDB::putbyte(uint8_t b)
386{
387    if (::write(fd, &b, sizeof(b)) == sizeof(b)) {
388        return true;
389    } else {
390        warn("Couldn't write data to the debugger, detaching.");
391        detach();
392        return false;
393    }
394}
395
396// Send a packet to gdb
397ssize_t
398BaseRemoteGDB::send(const char *bp)
399{
400    const char *p;
401    uint8_t csum, c;
402
403    DPRINTF(GDBSend, "send:  %s\n", bp);
404
405    do {
406        p = bp;
407        //Start sending a packet
408        if (!putbyte(GDBStart))
409            return -1;
410        //Send the contents, and also keep a check sum.
411        for (csum = 0; (c = *p); p++) {
412            if (!putbyte(c))
413                return -1;
414            csum += c;
415        }
416        if (//Send the ending character.
417            !putbyte(GDBEnd) ||
418            //Sent the checksum.
419            !putbyte(i2digit(csum >> 4)) ||
420            !putbyte(i2digit(csum))) {
421            return -1;
422        }
423        //Try transmitting over and over again until the other end doesn't
424        //send an error back.
425        if (!getbyte(c))
426            return -1;
427    } while ((c & 0x7f) == GDBBadP);
428    return 0;
429}
430
431// Receive a packet from gdb
432int
433BaseRemoteGDB::recv(char *bp, int maxlen)
434{
435    char *p;
436    uint8_t c;
437    int csum;
438    int len;
439
440    do {
441        p = bp;
442        csum = len = 0;
443        //Find the beginning of a packet
444        do {
445            if (!getbyte(c))
446                return -1;
447        } while (c != GDBStart);
448
449        //Read until you find the end of the data in the packet, and keep
450        //track of the check sum.
451        while (len < maxlen) {
452            if (!getbyte(c))
453                return -1;
454            if (c == GDBEnd)
455                break;
456            c &= 0x7f;
457            csum += c;
458            *p++ = c;
459            len++;
460        }
461
462        //Mask the check sum, and terminate the command string.
463        csum &= 0xff;
464        *p = '\0';
465
466        //If the command was too long, report an error.
467        if (len >= maxlen) {
468            if (!putbyte(GDBBadP))
469                return -1;
470            continue;
471        }
472
473        //Bring in the checksum. If the check sum matches, csum will be 0.
474        uint8_t csum1, csum2;
475        if (!getbyte(csum1) || !getbyte(csum2))
476            return -1;
477        csum -= digit2i(csum1) * 16;
478        csum -= digit2i(csum2);
479
480        //If the check sum was correct
481        if (csum == 0) {
482            //Report that the packet was received correctly
483            if (!putbyte(GDBGoodP))
484                return -1;
485            // Sequence present?
486            if (bp[2] == ':') {
487                if (!putbyte(bp[0]) || !putbyte(bp[1]))
488                    return -1;
489                len -= 3;
490                memcpy(bp, bp+3, len);
491            }
492            break;
493        }
494        //Otherwise, report that there was a mistake.
495        if (!putbyte(GDBBadP))
496            return -1;
497    } while (1);
498
499    DPRINTF(GDBRecv, "recv:  %s: %s\n", gdb_command(*bp), bp);
500
501    return (len);
502}
503
504// Read bytes from kernel address space for debugger.
505bool
506BaseRemoteGDB::read(Addr vaddr, size_t size, char *data)
507{
508    static Addr lastaddr = 0;
509    static size_t lastsize = 0;
510
511    if (vaddr < 10) {
512      DPRINTF(GDBRead, "read:  reading memory location zero!\n");
513      vaddr = lastaddr + lastsize;
514    }
515
516    DPRINTF(GDBRead, "read:  addr=%#x, size=%d", vaddr, size);
517
518    if (FullSystem) {
519        FSTranslatingPortProxy &proxy = context->getVirtProxy();
520        proxy.readBlob(vaddr, (uint8_t*)data, size);
521    } else {
522        SETranslatingPortProxy &proxy = context->getMemProxy();
523        proxy.readBlob(vaddr, (uint8_t*)data, size);
524    }
525
526#if TRACING_ON
527    if (DTRACE(GDBRead)) {
528        if (DTRACE(GDBExtra)) {
529            char buf[1024];
530            mem2hex(buf, data, size);
531            DPRINTFNR(": %s\n", buf);
532        } else
533            DPRINTFNR("\n");
534    }
535#endif
536
537    return true;
538}
539
540// Write bytes to kernel address space for debugger.
541bool
542BaseRemoteGDB::write(Addr vaddr, size_t size, const char *data)
543{
544    static Addr lastaddr = 0;
545    static size_t lastsize = 0;
546
547    if (vaddr < 10) {
548      DPRINTF(GDBWrite, "write: writing memory location zero!\n");
549      vaddr = lastaddr + lastsize;
550    }
551
552    if (DTRACE(GDBWrite)) {
553        DPRINTFN("write: addr=%#x, size=%d", vaddr, size);
554        if (DTRACE(GDBExtra)) {
555            char buf[1024];
556            mem2hex(buf, data, size);
557            DPRINTFNR(": %s\n", buf);
558        } else
559            DPRINTFNR("\n");
560    }
561    if (FullSystem) {
562        FSTranslatingPortProxy &proxy = context->getVirtProxy();
563        proxy.writeBlob(vaddr, (uint8_t*)data, size);
564    } else {
565        SETranslatingPortProxy &proxy = context->getMemProxy();
566        proxy.writeBlob(vaddr, (uint8_t*)data, size);
567    }
568
569    return true;
570}
571
572void
573BaseRemoteGDB::clearSingleStep()
574{
575    descheduleInstCommitEvent(&singleStepEvent);
576}
577
578void
579BaseRemoteGDB::setSingleStep()
580{
581    if (!singleStepEvent.scheduled())
582        scheduleInstCommitEvent(&singleStepEvent, 1);
583}
584
585PCEventQueue *BaseRemoteGDB::getPcEventQueue()
586{
587    return &system->pcEventQueue;
588}
589
590EventQueue *
591BaseRemoteGDB::getComInstEventQueue()
592{
593    BaseCPU *cpu = context->getCpuPtr();
594    return cpu->comInstEventQueue[context->threadId()];
595}
596
597void
598BaseRemoteGDB::scheduleInstCommitEvent(Event *ev, int delta)
599{
600    EventQueue *eq = getComInstEventQueue();
601    // Here "ticks" aren't simulator ticks which measure time, they're
602    // instructions committed by the CPU.
603    eq->schedule(ev, eq->getCurTick() + delta);
604}
605
606void
607BaseRemoteGDB::descheduleInstCommitEvent(Event *ev)
608{
609    if (ev->scheduled())
610        getComInstEventQueue()->deschedule(ev);
611}
612
613bool
614BaseRemoteGDB::checkBpLen(size_t len)
615{
616    return len == sizeof(MachInst);
617}
618
619BaseRemoteGDB::HardBreakpoint::HardBreakpoint(BaseRemoteGDB *_gdb, Addr pc)
620    : PCEvent(_gdb->getPcEventQueue(), "HardBreakpoint Event", pc),
621      gdb(_gdb), refcount(0)
622{
623    DPRINTF(GDBMisc, "creating hardware breakpoint at %#x\n", evpc);
624}
625
626void
627BaseRemoteGDB::HardBreakpoint::process(ThreadContext *tc)
628{
629    DPRINTF(GDBMisc, "handling hardware breakpoint at %#x\n", pc());
630
631    if (tc == gdb->context)
632        gdb->trap(SIGTRAP);
633}
634
635bool
636BaseRemoteGDB::insertSoftBreak(Addr addr, size_t len)
637{
638    if (!checkBpLen(len))
639        panic("invalid length\n");
640
641    return insertHardBreak(addr, len);
642}
643
644bool
645BaseRemoteGDB::removeSoftBreak(Addr addr, size_t len)
646{
647    if (!checkBpLen(len))
648        panic("invalid length\n");
649
650    return removeHardBreak(addr, len);
651}
652
653bool
654BaseRemoteGDB::insertHardBreak(Addr addr, size_t len)
655{
656    if (!checkBpLen(len))
657        panic("invalid length\n");
658
659    DPRINTF(GDBMisc, "inserting hardware breakpoint at %#x\n", addr);
660
661    HardBreakpoint *&bkpt = hardBreakMap[addr];
662    if (bkpt == 0)
663        bkpt = new HardBreakpoint(this, addr);
664
665    bkpt->refcount++;
666
667    return true;
668}
669
670bool
671BaseRemoteGDB::removeHardBreak(Addr addr, size_t len)
672{
673    if (!checkBpLen(len))
674        panic("invalid length\n");
675
676    DPRINTF(GDBMisc, "removing hardware breakpoint at %#x\n", addr);
677
678    break_iter_t i = hardBreakMap.find(addr);
679    if (i == hardBreakMap.end())
680        return false;
681
682    HardBreakpoint *hbp = (*i).second;
683    if (--hbp->refcount == 0) {
684        delete hbp;
685        hardBreakMap.erase(i);
686    }
687
688    return true;
689}
690
691void
692BaseRemoteGDB::setTempBreakpoint(Addr bkpt)
693{
694    DPRINTF(GDBMisc, "setTempBreakpoint: addr=%#x\n", bkpt);
695    insertHardBreak(bkpt, sizeof(TheISA::MachInst));
696}
697
698void
699BaseRemoteGDB::clearTempBreakpoint(Addr &bkpt)
700{
701    DPRINTF(GDBMisc, "setTempBreakpoint: addr=%#x\n", bkpt);
702    removeHardBreak(bkpt, sizeof(TheISA::MachInst));
703    bkpt = 0;
704}
705
706const char *
707BaseRemoteGDB::break_type(char c)
708{
709    switch(c) {
710      case '0': return "software breakpoint";
711      case '1': return "hardware breakpoint";
712      case '2': return "write watchpoint";
713      case '3': return "read watchpoint";
714      case '4': return "access watchpoint";
715      default: return "unknown breakpoint/watchpoint";
716    }
717}
718
719// This function does all command processing for interfacing to a
720// remote gdb.  Note that the error codes are ignored by gdb at
721// present, but might eventually become meaningful. (XXX) It might
722// makes sense to use POSIX errno values, because that is what the
723// gdb/remote.c functions want to return.
724bool
725BaseRemoteGDB::trap(int type)
726{
727    uint64_t val;
728    size_t datalen, len;
729    char data[GDBPacketBufLen + 1];
730    size_t bufferSize;
731    const char *p;
732    char command, subcmd;
733    string var;
734    bool ret;
735
736    if (!attached)
737        return false;
738
739    unique_ptr<BaseRemoteGDB::BaseGdbRegCache> regCache(gdbRegs());
740
741    bufferSize = regCache->size() * 2 + 256;
742    unique_ptr<char[]> buffer_mem(new char[bufferSize]);
743    char *buffer = buffer_mem.get();
744
745    DPRINTF(GDBMisc, "trap: PC=%s\n", context->pcState());
746
747    clearSingleStep();
748
749    /*
750     * The first entry to this function is normally through
751     * a breakpoint trap in kgdb_connect(), in which case we
752     * must advance past the breakpoint because gdb will not.
753     *
754     * On the first entry here, we expect that gdb is not yet
755     * listening to us, so just enter the interaction loop.
756     * After the debugger is "active" (connected) it will be
757     * waiting for a "signaled" message from us.
758     */
759    if (!active) {
760        active = true;
761    } else {
762        // Tell remote host that an exception has occurred.
763        snprintf(buffer, bufferSize, "S%02x", type);
764        if (send(buffer) < 0)
765            return true;
766    }
767
768    // Stick frame regs into our reg cache.
769    regCache->getRegs(context);
770
771    for (;;) {
772        int recved = recv(data, sizeof(data));
773        if (recved < 0)
774            return true;
775        datalen = recved;
776        data[sizeof(data) - 1] = 0; // Sentinel
777        command = data[0];
778        subcmd = 0;
779        p = data + 1;
780        switch (command) {
781
782          case GDBSignal:
783            // if this command came from a running gdb, answer it --
784            // the other guy has no way of knowing if we're in or out
785            // of this loop when he issues a "remote-signal".
786            snprintf(buffer, bufferSize,
787                    "S%02x", type);
788            if (send(buffer) < 0)
789                return true;
790            continue;
791
792          case GDBRegR:
793            if (2 * regCache->size() > bufferSize)
794                panic("buffer too small");
795
796            mem2hex(buffer, regCache->data(), regCache->size());
797            if (send(buffer) < 0)
798                return true;
799            continue;
800
801          case GDBRegW:
802            p = hex2mem(regCache->data(), p, regCache->size());
803            if (p == NULL || *p != '\0') {
804                if (send("E01") < 0)
805                    return true;
806            } else {
807                regCache->setRegs(context);
808                if (send("OK") < 0)
809                    return true;
810            }
811            continue;
812
813          case GDBMemR:
814            val = hex2i(&p);
815            if (*p++ != ',') {
816                if (send("E02") < 0)
817                    return true;
818                continue;
819            }
820            len = hex2i(&p);
821            if (*p != '\0') {
822                if (send("E03") < 0)
823                    return true;
824                continue;
825            }
826            if (len > bufferSize) {
827                if (send("E04") < 0)
828                    return true;
829                continue;
830            }
831            if (!acc(val, len)) {
832                if (send("E05") < 0)
833                    return true;
834                continue;
835            }
836
837            if (read(val, (size_t)len, buffer)) {
838               // variable length array would be nice, but C++ doesn't
839               // officially support those...
840               char *temp = new char[2*len+1];
841               mem2hex(temp, buffer, len);
842               if (send(temp) < 0) {
843                   delete [] temp;
844                   return true;
845               }
846               delete [] temp;
847            } else {
848               if (send("E05") < 0)
849                   return true;
850            }
851            continue;
852
853          case GDBMemW:
854            val = hex2i(&p);
855            if (*p++ != ',') {
856                if (send("E06") < 0)
857                    return true;
858                continue;
859            }
860            len = hex2i(&p);
861            if (*p++ != ':') {
862                if (send("E07") < 0)
863                    return true;
864                continue;
865            }
866            if (len > datalen - (p - data)) {
867                if (send("E08") < 0)
868                    return true;
869                continue;
870            }
871            p = hex2mem(buffer, p, bufferSize);
872            if (p == NULL) {
873                if (send("E09") < 0)
874                    return true;
875                continue;
876            }
877            if (!acc(val, len)) {
878                if (send("E0A") < 0)
879                    return true;
880                continue;
881            }
882            if (write(val, (size_t)len, buffer)) {
883                if (send("OK") < 0)
884                    return true;
885            } else {
886                if (send("E0B") < 0)
887                    return true;
888            }
889            continue;
890
891          case GDBSetThread:
892            subcmd = *p++;
893            val = hex2i(&p);
894            if (val == 0) {
895                if (send("OK") < 0)
896                    return true;
897            } else {
898                if (send("E01") < 0)
899                    return true;
900            }
901            continue;
902
903          case GDBDetach:
904          case GDBKill:
905            active = false;
906            clearSingleStep();
907            detach();
908            return true;
909
910          case GDBAsyncCont:
911            subcmd = hex2i(&p);
912            if (*p++ == ';') {
913                val = hex2i(&p);
914                context->pcState(val);
915            }
916            clearSingleStep();
917            return true;
918
919          case GDBCont:
920            if (p - data < (ptrdiff_t)datalen) {
921                val = hex2i(&p);
922                context->pcState(val);
923            }
924            clearSingleStep();
925            return true;
926
927          case GDBAsyncStep:
928            subcmd = hex2i(&p);
929            if (*p++ == ';') {
930                val = hex2i(&p);
931                context->pcState(val);
932            }
933            setSingleStep();
934            return true;
935
936          case GDBStep:
937            if (p - data < (ptrdiff_t)datalen) {
938                val = hex2i(&p);
939                context->pcState(val);
940            }
941            setSingleStep();
942            return true;
943
944          case GDBClrHwBkpt:
945            subcmd = *p++;
946            if (*p++ != ',' && send("E0D") < 0)
947                return true;
948            val = hex2i(&p);
949            if (*p++ != ',' && send("E0D") < 0)
950                return true;
951            len = hex2i(&p);
952
953            DPRINTF(GDBMisc, "clear %s, addr=%#x, len=%d\n",
954                    break_type(subcmd), val, len);
955
956            ret = false;
957
958            switch (subcmd) {
959              case '0': // software breakpoint
960                ret = removeSoftBreak(val, len);
961                break;
962
963              case '1': // hardware breakpoint
964                ret = removeHardBreak(val, len);
965                break;
966
967              case '2': // write watchpoint
968              case '3': // read watchpoint
969              case '4': // access watchpoint
970              default: // unknown
971                if (send("") < 0)
972                    return true;
973                break;
974            }
975
976            if (send(ret ? "OK" : "E0C") < 0)
977                return true;
978            continue;
979
980          case GDBSetHwBkpt:
981            subcmd = *p++;
982            if (*p++ != ',' && send("E0D") < 0)
983                return true;
984            val = hex2i(&p);
985            if (*p++ != ',' && send("E0D") < 0)
986                return true;
987            len = hex2i(&p);
988
989            DPRINTF(GDBMisc, "set %s, addr=%#x, len=%d\n",
990                    break_type(subcmd), val, len);
991
992            ret = false;
993
994            switch (subcmd) {
995              case '0': // software breakpoint
996                ret = insertSoftBreak(val, len);
997                break;
998
999              case '1': // hardware breakpoint
1000                ret = insertHardBreak(val, len);
1001                break;
1002
1003              case '2': // write watchpoint
1004              case '3': // read watchpoint
1005              case '4': // access watchpoint
1006              default: // unknown
1007                if (send("") < 0)
1008                    return true;
1009                break;
1010            }
1011
1012            if (send(ret ? "OK" : "E0C") < 0)
1013                return true;
1014            continue;
1015
1016          case GDBQueryVar:
1017            var = string(p, datalen - 1);
1018            if (var == "C") {
1019                if (send("QC0") < 0)
1020                    return true;
1021            } else {
1022                if (send("") < 0)
1023                    return true;
1024            }
1025            continue;
1026
1027          case GDBSetBaud:
1028          case GDBSetBreak:
1029          case GDBDebug:
1030          case GDBCycleStep:
1031          case GDBSigCycleStep:
1032          case GDBReadReg:
1033          case GDBSetVar:
1034          case GDBReset:
1035          case GDBThreadAlive:
1036          case GDBTargetExit:
1037          case GDBBinaryDload:
1038            // Unsupported command
1039            DPRINTF(GDBMisc, "Unsupported command: %s\n",
1040                    gdb_command(command));
1041            DDUMP(GDBMisc, (uint8_t *)data, datalen);
1042            if (send("") < 0)
1043                return true;
1044            continue;
1045
1046          default:
1047            // Unknown command.
1048            DPRINTF(GDBMisc, "Unknown command: %c(%#x)\n",
1049                    command, command);
1050            if (send("") < 0)
1051                return true;
1052            continue;
1053
1054
1055        }
1056    }
1057
1058    return true;
1059}
1060
1061// Convert a hex digit into an integer.
1062// This returns -1 if the argument passed is no valid hex digit.
1063int
1064BaseRemoteGDB::digit2i(char c)
1065{
1066    if (c >= '0' && c <= '9')
1067        return (c - '0');
1068    else if (c >= 'a' && c <= 'f')
1069        return (c - 'a' + 10);
1070    else if (c >= 'A' && c <= 'F')
1071
1072        return (c - 'A' + 10);
1073    else
1074        return (-1);
1075}
1076
1077// Convert the low 4 bits of an integer into an hex digit.
1078char
1079BaseRemoteGDB::i2digit(int n)
1080{
1081    return ("0123456789abcdef"[n & 0x0f]);
1082}
1083
1084// Convert a byte array into an hex string.
1085void
1086BaseRemoteGDB::mem2hex(char *vdst, const char *vsrc, int len)
1087{
1088    char *dst = vdst;
1089    const char *src = vsrc;
1090
1091    while (len--) {
1092        *dst++ = i2digit(*src >> 4);
1093        *dst++ = i2digit(*src++);
1094    }
1095    *dst = '\0';
1096}
1097
1098// Convert an hex string into a byte array.
1099// This returns a pointer to the character following the last valid
1100// hex digit. If the string ends in the middle of a byte, NULL is
1101// returned.
1102const char *
1103BaseRemoteGDB::hex2mem(char *vdst, const char *src, int maxlen)
1104{
1105    char *dst = vdst;
1106    int msb, lsb;
1107
1108    while (*src && maxlen--) {
1109        msb = digit2i(*src++);
1110        if (msb < 0)
1111            return (src - 1);
1112        lsb = digit2i(*src++);
1113        if (lsb < 0)
1114            return (NULL);
1115        *dst++ = (msb << 4) | lsb;
1116    }
1117    return (src);
1118}
1119
1120// Convert an hex string into an integer.
1121// This returns a pointer to the character following the last valid
1122// hex digit.
1123Addr
1124BaseRemoteGDB::hex2i(const char **srcp)
1125{
1126    const char *src = *srcp;
1127    Addr r = 0;
1128    int nibble;
1129
1130    while ((nibble = digit2i(*src)) >= 0) {
1131        r *= 16;
1132        r += nibble;
1133        src++;
1134    }
1135    *srcp = src;
1136    return (r);
1137}
1138
1139