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 --- 140 unchanged lines hidden (view full) --- 149 150static const char GDBStart = '$'; 151static const char GDBEnd = '#'; 152static const char GDBGoodP = '+'; 153static const char GDBBadP = '-'; 154 155static const int GDBPacketBufLen = 1024; 156 |
157vector<BaseRemoteGDB *> debuggers; 158 |
159class HardBreakpoint : public PCEvent |
160{ |
161 private: 162 BaseRemoteGDB *gdb; 163 164 public: 165 int refcount; 166 167 public: 168 HardBreakpoint(BaseRemoteGDB *_gdb, PCEventQueue *q, Addr pc) 169 : PCEvent(q, "HardBreakpoint Event", pc), 170 gdb(_gdb), refcount(0) 171 { 172 DPRINTF(GDBMisc, "creating hardware breakpoint at %#x\n", evpc); |
173 } |
174 |
175 const std::string name() const { return gdb->name() + ".hwbkpt"; } |
176 |
177 void 178 process(ThreadContext *tc) override 179 { 180 DPRINTF(GDBMisc, "handling hardware breakpoint at %#x\n", pc()); |
181 |
182 if (tc == gdb->tc) 183 gdb->trap(SIGTRAP); 184 } 185}; 186 187namespace { 188 189// Exception to throw when the connection to the client is broken. 190struct BadClient |
191{ |
192 const char *warning; 193 BadClient(const char *_warning=NULL) : warning(_warning) 194 {} 195}; |
196 |
197// Exception to throw when an error needs to be reported to the client. 198struct CmdError |
199{ |
200 string error; 201 CmdError(std::string _error) : error(_error) 202 {} 203}; |
204 |
205// Exception to throw when something isn't supported. 206class Unsupported {}; 207 208// Convert a hex digit into an integer. 209// This returns -1 if the argument passed is no valid hex digit. 210int 211digit2i(char c) |
212{ |
213 if (c >= '0' && c <= '9') 214 return (c - '0'); 215 else if (c >= 'a' && c <= 'f') 216 return (c - 'a' + 10); 217 else if (c >= 'A' && c <= 'F') 218 return (c - 'A' + 10); 219 else 220 return (-1); |
221} 222 |
223// Convert the low 4 bits of an integer into an hex digit. 224char 225i2digit(int n) |
226{ |
227 return ("0123456789abcdef"[n & 0x0f]); |
228} 229 |
230// Convert a byte array into an hex string. |
231void |
232mem2hex(char *vdst, const char *vsrc, int len) |
233{ |
234 char *dst = vdst; 235 const char *src = vsrc; |
236 |
237 while (len--) { 238 *dst++ = i2digit(*src >> 4); 239 *dst++ = i2digit(*src++); |
240 } |
241 *dst = '\0'; |
242} 243 |
244// Convert an hex string into a byte array. 245// This returns a pointer to the character following the last valid 246// hex digit. If the string ends in the middle of a byte, NULL is 247// returned. 248const char * 249hex2mem(char *vdst, const char *src, int maxlen) |
250{ |
251 char *dst = vdst; 252 int msb, lsb; |
253 |
254 while (*src && maxlen--) { 255 msb = digit2i(*src++); 256 if (msb < 0) 257 return (src - 1); 258 lsb = digit2i(*src++); 259 if (lsb < 0) 260 return (NULL); 261 *dst++ = (msb << 4) | lsb; |
262 } |
263 return src; |
264} 265 |
266// Convert an hex string into an integer. 267// This returns a pointer to the character following the last valid 268// hex digit. 269Addr 270hex2i(const char **srcp) |
271{ |
272 const char *src = *srcp; 273 Addr r = 0; 274 int nibble; |
275 |
276 while ((nibble = digit2i(*src)) >= 0) { 277 r *= 16; 278 r += nibble; 279 src++; 280 } 281 *srcp = src; 282 return r; |
283} 284 |
285enum GdbBreakpointType { 286 GdbSoftBp = '0', 287 GdbHardBp = '1', 288 GdbWriteWp = '2', 289 GdbReadWp = '3', 290 GdbAccWp = '4', 291}; |
292 |
293const char * 294break_type(char c) |
295{ |
296 switch(c) { 297 case GdbSoftBp: return "software breakpoint"; 298 case GdbHardBp: return "hardware breakpoint"; 299 case GdbWriteWp: return "write watchpoint"; 300 case GdbReadWp: return "read watchpoint"; 301 case GdbAccWp: return "access watchpoint"; 302 default: return "unknown breakpoint/watchpoint"; |
303 } |
304} 305 |
306std::map<Addr, HardBreakpoint *> hardBreakMap; 307 308EventQueue * 309getComInstEventQueue(ThreadContext *tc) |
310{ |
311 return tc->getCpuPtr()->comInstEventQueue[tc->threadId()]; |
312} 313 |
314} 315 |
316BaseRemoteGDB::BaseRemoteGDB(System *_system, ThreadContext *c, int _port) : 317 connectEvent(nullptr), dataEvent(nullptr), _port(_port), fd(-1), 318 active(false), attached(false), sys(_system), tc(c), 319 trapEvent(this), singleStepEvent(*this) |
320{ |
321 debuggers.push_back(this); |
322} 323 324BaseRemoteGDB::~BaseRemoteGDB() 325{ |
326 delete connectEvent; 327 delete dataEvent; |
328} 329 330string 331BaseRemoteGDB::name() 332{ |
333 return sys->name() + ".remote_gdb"; |
334} 335 |
336void 337BaseRemoteGDB::listen() 338{ 339 if (ListenSocket::allDisabled()) { 340 warn_once("Sockets disabled, not accepting gdb connections"); 341 return; 342 } |
343 |
344 while (!listener.listen(_port, true)) { 345 DPRINTF(GDBMisc, "Can't bind port %d\n", _port); 346 _port++; 347 } 348 349 connectEvent = new ConnectEvent(this, listener.getfd(), POLLIN); 350 pollQueue.schedule(connectEvent); 351 352 ccprintf(cerr, "%d: %s: listening for remote gdb on port %d\n", 353 curTick(), name(), _port); 354} 355 |
356void |
357BaseRemoteGDB::connect() 358{ 359 panic_if(!listener.islistening(), 360 "Cannot accept GDB connections if we're not listening!"); 361 362 int sfd = listener.accept(true); 363 364 if (sfd != -1) { 365 if (isAttached()) 366 close(sfd); 367 else 368 attach(sfd); 369 } 370} 371 372int 373BaseRemoteGDB::port() const 374{ 375 panic_if(!listener.islistening(), 376 "Remote GDB port is unknown until listen() has been called.\n"); 377 return _port; 378} 379 380void |
381BaseRemoteGDB::attach(int f) 382{ 383 fd = f; 384 |
385 dataEvent = new DataEvent(this, fd, POLLIN); 386 pollQueue.schedule(dataEvent); |
387 388 attached = true; 389 DPRINTFN("remote gdb attached\n"); 390} 391 392void 393BaseRemoteGDB::detach() 394{ 395 attached = false; 396 active = false; 397 clearSingleStep(); 398 close(fd); 399 fd = -1; 400 |
401 pollQueue.remove(dataEvent); |
402 DPRINTFN("remote gdb detached\n"); 403} 404 |
405// This function does all command processing for interfacing to a 406// remote gdb. Note that the error codes are ignored by gdb at 407// present, but might eventually become meaningful. (XXX) It might 408// makes sense to use POSIX errno values, because that is what the 409// gdb/remote.c functions want to return. 410bool 411BaseRemoteGDB::trap(int type) 412{ |
413 |
414 if (!attached) 415 return false; 416 417 DPRINTF(GDBMisc, "trap: PC=%s\n", tc->pcState()); 418 419 clearSingleStep(); 420 421 /* 422 * The first entry to this function is normally through 423 * a breakpoint trap in kgdb_connect(), in which case we 424 * must advance past the breakpoint because gdb will not. 425 * 426 * On the first entry here, we expect that gdb is not yet 427 * listening to us, so just enter the interaction loop. 428 * After the debugger is "active" (connected) it will be 429 * waiting for a "signaled" message from us. 430 */ 431 if (!active) { 432 active = true; 433 } else { 434 // Tell remote host that an exception has occurred. 435 send(csprintf("S%02x", type).c_str()); 436 } 437 438 // Stick frame regs into our reg cache. 439 regCachePtr = gdbRegs(); 440 regCachePtr->getRegs(tc); 441 442 char data[GDBPacketBufLen + 1]; 443 GdbCommand::Context cmdCtx; 444 cmdCtx.type = type; 445 cmdCtx.data = &data[1]; 446 447 for (;;) { 448 try { 449 size_t datalen = recv(data, sizeof(data)); 450 if (datalen < 1) 451 throw BadClient(); 452 453 data[datalen] = 0; // Sentinel 454 cmdCtx.cmd_byte = data[0]; 455 cmdCtx.len = datalen - 1; 456 457 auto cmdIt = command_map.find(cmdCtx.cmd_byte); 458 if (cmdIt == command_map.end()) { 459 DPRINTF(GDBMisc, "Unknown command: %c(%#x)\n", 460 cmdCtx.cmd_byte, cmdCtx.cmd_byte); 461 throw Unsupported(); 462 } 463 cmdCtx.cmd = &(cmdIt->second); 464 465 if (!(this->*(cmdCtx.cmd->func))(cmdCtx)) 466 break; 467 468 } catch (BadClient &e) { 469 if (e.warning) 470 warn(e.warning); 471 detach(); 472 break; 473 } catch (Unsupported &e) { 474 send(""); 475 } catch (CmdError &e) { 476 send(e.error.c_str()); 477 } catch (...) { 478 panic("Unrecognzied GDB exception."); 479 } 480 } 481 482 return true; 483} 484 485void 486BaseRemoteGDB::incomingData(int revent) 487{ 488 if (trapEvent.scheduled()) { 489 warn("GDB trap event has already been scheduled!"); 490 return; 491 } 492 493 if (revent & POLLIN) { 494 trapEvent.type(SIGILL); 495 scheduleInstCommitEvent(&trapEvent, 0); 496 } else if (revent & POLLNVAL) { 497 descheduleInstCommitEvent(&trapEvent); 498 detach(); 499 } 500} 501 |
502uint8_t 503BaseRemoteGDB::getbyte() 504{ 505 uint8_t b; 506 if (::read(fd, &b, sizeof(b)) == sizeof(b)) 507 return b; 508 509 throw BadClient("Couldn't read data from debugger."); 510} 511 512void 513BaseRemoteGDB::putbyte(uint8_t b) 514{ 515 if (::write(fd, &b, sizeof(b)) == sizeof(b)) 516 return; 517 518 throw BadClient("Couldn't write data to the debugger."); 519} 520 |
521// Receive a packet from gdb 522int 523BaseRemoteGDB::recv(char *bp, int maxlen) 524{ 525 char *p; 526 uint8_t c; 527 int csum; 528 int len; --- 47 unchanged lines hidden (view full) --- 576 putbyte(GDBBadP); 577 } while (1); 578 579 DPRINTF(GDBRecv, "recv: %s\n", bp); 580 581 return len; 582} 583 |
584// Send a packet to gdb 585void 586BaseRemoteGDB::send(const char *bp) 587{ 588 const char *p; 589 uint8_t csum, c; 590 591 DPRINTF(GDBSend, "send: %s\n", bp); 592 593 do { 594 p = bp; 595 // Start sending a packet 596 putbyte(GDBStart); 597 // Send the contents, and also keep a check sum. 598 for (csum = 0; (c = *p); p++) { 599 putbyte(c); 600 csum += c; 601 } 602 // Send the ending character. 603 putbyte(GDBEnd); 604 // Send the checksum. 605 putbyte(i2digit(csum >> 4)); 606 putbyte(i2digit(csum)); 607 // Try transmitting over and over again until the other end doesn't 608 // send an error back. 609 c = getbyte(); 610 } while ((c & 0x7f) == GDBBadP); 611} 612 |
613// Read bytes from kernel address space for debugger. 614bool 615BaseRemoteGDB::read(Addr vaddr, size_t size, char *data) 616{ 617 static Addr lastaddr = 0; 618 static size_t lastsize = 0; 619 620 if (vaddr < 10) { 621 DPRINTF(GDBRead, "read: reading memory location zero!\n"); 622 vaddr = lastaddr + lastsize; 623 } 624 625 DPRINTF(GDBRead, "read: addr=%#x, size=%d", vaddr, size); 626 627 if (FullSystem) { |
628 FSTranslatingPortProxy &proxy = tc->getVirtProxy(); |
629 proxy.readBlob(vaddr, (uint8_t*)data, size); 630 } else { |
631 SETranslatingPortProxy &proxy = tc->getMemProxy(); |
632 proxy.readBlob(vaddr, (uint8_t*)data, size); 633 } 634 635#if TRACING_ON 636 if (DTRACE(GDBRead)) { 637 if (DTRACE(GDBExtra)) { 638 char buf[1024]; 639 mem2hex(buf, data, size); --- 23 unchanged lines hidden (view full) --- 663 if (DTRACE(GDBExtra)) { 664 char buf[1024]; 665 mem2hex(buf, data, size); 666 DPRINTFNR(": %s\n", buf); 667 } else 668 DPRINTFNR("\n"); 669 } 670 if (FullSystem) { |
671 FSTranslatingPortProxy &proxy = tc->getVirtProxy(); |
672 proxy.writeBlob(vaddr, (uint8_t*)data, size); 673 } else { |
674 SETranslatingPortProxy &proxy = tc->getMemProxy(); |
675 proxy.writeBlob(vaddr, (uint8_t*)data, size); 676 } 677 678 return true; 679} 680 681void |
682BaseRemoteGDB::singleStep() |
683{ |
684 if (!singleStepEvent.scheduled()) 685 scheduleInstCommitEvent(&singleStepEvent, 1); |
686 trap(SIGTRAP); |
687} 688 |
689void |
690BaseRemoteGDB::clearSingleStep() |
691{ |
692 descheduleInstCommitEvent(&singleStepEvent); |
693} 694 695void |
696BaseRemoteGDB::setSingleStep() |
697{ |
698 if (!singleStepEvent.scheduled()) 699 scheduleInstCommitEvent(&singleStepEvent, 1); |
700} 701 |
702void |
703BaseRemoteGDB::insertSoftBreak(Addr addr, size_t len) 704{ 705 if (!checkBpLen(len)) 706 throw BadClient("Invalid breakpoint length\n"); 707 708 return insertHardBreak(addr, len); 709} 710 --- 11 unchanged lines hidden (view full) --- 722{ 723 if (!checkBpLen(len)) 724 throw BadClient("Invalid breakpoint length\n"); 725 726 DPRINTF(GDBMisc, "Inserting hardware breakpoint at %#x\n", addr); 727 728 HardBreakpoint *&bkpt = hardBreakMap[addr]; 729 if (bkpt == 0) |
730 bkpt = new HardBreakpoint(this, &sys->pcEventQueue, addr); |
731 732 bkpt->refcount++; 733} 734 735void 736BaseRemoteGDB::removeHardBreak(Addr addr, size_t len) 737{ 738 if (!checkBpLen(len)) 739 throw BadClient("Invalid breakpoint length\n"); 740 741 DPRINTF(GDBMisc, "Removing hardware breakpoint at %#x\n", addr); 742 |
743 auto i = hardBreakMap.find(addr); |
744 if (i == hardBreakMap.end()) 745 throw CmdError("E0C"); 746 747 HardBreakpoint *hbp = (*i).second; 748 if (--hbp->refcount == 0) { 749 delete hbp; 750 hardBreakMap.erase(i); 751 } 752} 753 754void |
755BaseRemoteGDB::clearTempBreakpoint(Addr &bkpt) 756{ 757 DPRINTF(GDBMisc, "setTempBreakpoint: addr=%#x\n", bkpt); 758 removeHardBreak(bkpt, sizeof(TheISA::MachInst)); 759 bkpt = 0; 760} 761 762void |
763BaseRemoteGDB::setTempBreakpoint(Addr bkpt) 764{ 765 DPRINTF(GDBMisc, "setTempBreakpoint: addr=%#x\n", bkpt); 766 insertHardBreak(bkpt, sizeof(TheISA::MachInst)); 767} 768 769void |
770BaseRemoteGDB::scheduleInstCommitEvent(Event *ev, int delta) |
771{ |
772 EventQueue *eq = getComInstEventQueue(tc); 773 // Here "ticks" aren't simulator ticks which measure time, they're 774 // instructions committed by the CPU. 775 eq->schedule(ev, eq->getCurTick() + delta); |
776} 777 |
778void 779BaseRemoteGDB::descheduleInstCommitEvent(Event *ev) |
780{ |
781 if (ev->scheduled()) 782 getComInstEventQueue(tc)->deschedule(ev); |
783} 784 |
785std::map<char, BaseRemoteGDB::GdbCommand> BaseRemoteGDB::command_map = { |
786 // last signal 787 { '?', { "KGDB_SIGNAL", &BaseRemoteGDB::cmd_signal } }, 788 // set baud (deprecated) 789 { 'b', { "KGDB_SET_BAUD", &BaseRemoteGDB::cmd_unsupported } }, 790 // set breakpoint (deprecated) 791 { 'B', { "KGDB_SET_BREAK", &BaseRemoteGDB::cmd_unsupported } }, 792 // resume 793 { 'c', { "KGDB_CONT", &BaseRemoteGDB::cmd_cont } }, --- 40 unchanged lines hidden (view full) --- 834 // write memory 835 { 'X', { "KGDB_BINARY_DLOAD", &BaseRemoteGDB::cmd_unsupported } }, 836 // remove breakpoint or watchpoint 837 { 'z', { "KGDB_CLR_HW_BKPT", &BaseRemoteGDB::cmd_clr_hw_bkpt } }, 838 // insert breakpoint or watchpoint 839 { 'Z', { "KGDB_SET_HW_BKPT", &BaseRemoteGDB::cmd_set_hw_bkpt } }, 840}; 841 |
842bool 843BaseRemoteGDB::checkBpLen(size_t len) 844{ 845 return len == sizeof(MachInst); 846} |
847 848bool 849BaseRemoteGDB::cmd_unsupported(GdbCommand::Context &ctx) 850{ 851 DPRINTF(GDBMisc, "Unsupported command: %s\n", ctx.cmd->name); 852 DDUMP(GDBMisc, ctx.data, ctx.len); 853 throw Unsupported(); 854} --- 7 unchanged lines hidden (view full) --- 862} 863 864bool 865BaseRemoteGDB::cmd_cont(GdbCommand::Context &ctx) 866{ 867 const char *p = ctx.data; 868 if (ctx.len) { 869 Addr newPc = hex2i(&p); |
870 tc->pcState(newPc); |
871 } 872 clearSingleStep(); 873 return false; 874} 875 876bool 877BaseRemoteGDB::cmd_async_cont(GdbCommand::Context &ctx) 878{ 879 const char *p = ctx.data; 880 hex2i(&p); 881 if (*p++ == ';') { 882 Addr newPc = hex2i(&p); |
883 tc->pcState(newPc); |
884 } 885 clearSingleStep(); 886 return false; 887} 888 889bool 890BaseRemoteGDB::cmd_detach(GdbCommand::Context &ctx) 891{ --- 14 unchanged lines hidden (view full) --- 906bool 907BaseRemoteGDB::cmd_reg_w(GdbCommand::Context &ctx) 908{ 909 const char *p = ctx.data; 910 p = hex2mem(regCachePtr->data(), p, regCachePtr->size()); 911 if (p == NULL || *p != '\0') 912 throw CmdError("E01"); 913 |
914 regCachePtr->setRegs(tc); |
915 send("OK"); 916 917 return true; 918} 919 920bool 921BaseRemoteGDB::cmd_set_thread(GdbCommand::Context &ctx) 922{ --- 63 unchanged lines hidden (view full) --- 986 987bool 988BaseRemoteGDB::cmd_async_step(GdbCommand::Context &ctx) 989{ 990 const char *p = ctx.data; 991 hex2i(&p); // Ignore the subcommand byte. 992 if (*p++ == ';') { 993 Addr newPc = hex2i(&p); |
994 tc->pcState(newPc); |
995 } 996 setSingleStep(); 997 return false; 998} 999 1000bool 1001BaseRemoteGDB::cmd_step(GdbCommand::Context &ctx) 1002{ 1003 if (ctx.len) { 1004 const char *p = ctx.data; 1005 Addr newPc = hex2i(&p); |
1006 tc->pcState(newPc); |
1007 } 1008 setSingleStep(); 1009 return false; 1010} 1011 1012bool 1013BaseRemoteGDB::cmd_clr_hw_bkpt(GdbCommand::Context &ctx) 1014{ --- 54 unchanged lines hidden (view full) --- 1069 case GdbAccWp: 1070 default: // unknown 1071 throw Unsupported(); 1072 } 1073 send("OK"); 1074 1075 return true; 1076} |