gdbstub.c

   1 /*
   2  * gdb server stub
   3  *
   4  * This implements a subset of the remote protocol as described in:
   5  *
   6  *   https://sourceware.org/gdb/onlinedocs/gdb/Remote-Protocol.html
   7  *
   8  * Copyright (c) 2003-2005 Fabrice Bellard
   9  *
  10  * This library is free software; you can redistribute it and/or
  11  * modify it under the terms of the GNU Lesser General Public
  12  * License as published by the Free Software Foundation; either
  13  * version 2 of the License, or (at your option) any later version.
  14  *
  15  * This library is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  18  * Lesser General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU Lesser General Public
  21  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
  22  *
  23  * SPDX-License-Identifier: LGPL-2.0+
  24  */
  25
  26 #include "qemu/osdep.h"
  27 #include "qemu-common.h"
  28 #include "qapi/error.h"
  29 #include "qemu/error-report.h"
  30 #include "qemu/ctype.h"
  31 #include "qemu/cutils.h"
  32 #include "qemu/module.h"
  33 #include "trace/trace-root.h"
  34 #ifdef CONFIG_USER_ONLY
  35 #include "qemu.h"
  36 #else
  37 #include "monitor/monitor.h"
  38 #include "chardev/char.h"
  39 #include "chardev/char-fe.h"
  40 #include "sysemu/sysemu.h"
  41 #include "exec/gdbstub.h"
  42 #include "hw/cpu/cluster.h"
  43 #include "hw/boards.h"
  44 #endif
  45
  46 #define MAX_PACKET_LENGTH 4096
  47
  48 #include "qemu/sockets.h"
  49 #include "sysemu/hw_accel.h"
  50 #include "sysemu/kvm.h"
  51 #include "sysemu/runstate.h"
  52 #include "hw/semihosting/semihost.h"
  53 #include "exec/exec-all.h"
  54 #include "sysemu/replay.h"
  55
  56 #ifdef CONFIG_USER_ONLY
  57 #define GDB_ATTACHED "0"
  58 #else
  59 #define GDB_ATTACHED "1"
  60 #endif
  61
  62 #ifndef CONFIG_USER_ONLY
  63 static int phy_memory_mode;
  64 #endif
  65
  66 static inline int target_memory_rw_debug(CPUState *cpu, target_ulong addr,
  67                                          uint8_t *buf, int len, bool is_write)
  68 {
  69     CPUClass *cc;
  70
  71 #ifndef CONFIG_USER_ONLY
  72     if (phy_memory_mode) {
  73         if (is_write) {
  74             cpu_physical_memory_write(addr, buf, len);
  75         } else {
  76             cpu_physical_memory_read(addr, buf, len);
  77         }
  78         return 0;
  79     }
  80 #endif
  81
  82     cc = CPU_GET_CLASS(cpu);
  83     if (cc->memory_rw_debug) {
  84         return cc->memory_rw_debug(cpu, addr, buf, len, is_write);
  85     }
  86     return cpu_memory_rw_debug(cpu, addr, buf, len, is_write);
  87 }
  88
  89 /* Return the GDB index for a given vCPU state.
  90  *
  91  * For user mode this is simply the thread id. In system mode GDB
  92  * numbers CPUs from 1 as 0 is reserved as an "any cpu" index.
  93  */
  94 static inline int cpu_gdb_index(CPUState *cpu)
  95 {
  96 #if defined(CONFIG_USER_ONLY)
  97     TaskState *ts = (TaskState *) cpu->opaque;
  98     return ts->ts_tid;
  99 #else
 100     return cpu->cpu_index + 1;
 101 #endif
 102 }
 103
 104 enum {
 105     GDB_SIGNAL_0 = 0,
 106     GDB_SIGNAL_INT = 2,
 107     GDB_SIGNAL_QUIT = 3,
 108     GDB_SIGNAL_TRAP = 5,
 109     GDB_SIGNAL_ABRT = 6,
 110     GDB_SIGNAL_ALRM = 14,
 111     GDB_SIGNAL_IO = 23,
 112     GDB_SIGNAL_XCPU = 24,
 113     GDB_SIGNAL_UNKNOWN = 143
 114 };
 115
 116 #ifdef CONFIG_USER_ONLY
 117
 118 /* Map target signal numbers to GDB protocol signal numbers and vice
 119  * versa.  For user emulation's currently supported systems, we can
 120  * assume most signals are defined.
 121  */
 122
 123 static int gdb_signal_table[] = {
 124     0,
 125     TARGET_SIGHUP,
 126     TARGET_SIGINT,
 127     TARGET_SIGQUIT,
 128     TARGET_SIGILL,
 129     TARGET_SIGTRAP,
 130     TARGET_SIGABRT,
 131     -1, /* SIGEMT */
 132     TARGET_SIGFPE,
 133     TARGET_SIGKILL,
 134     TARGET_SIGBUS,
 135     TARGET_SIGSEGV,
 136     TARGET_SIGSYS,
 137     TARGET_SIGPIPE,
 138     TARGET_SIGALRM,
 139     TARGET_SIGTERM,
 140     TARGET_SIGURG,
 141     TARGET_SIGSTOP,
 142     TARGET_SIGTSTP,
 143     TARGET_SIGCONT,
 144     TARGET_SIGCHLD,
 145     TARGET_SIGTTIN,
 146     TARGET_SIGTTOU,
 147     TARGET_SIGIO,
 148     TARGET_SIGXCPU,
 149     TARGET_SIGXFSZ,
 150     TARGET_SIGVTALRM,
 151     TARGET_SIGPROF,
 152     TARGET_SIGWINCH,
 153     -1, /* SIGLOST */
 154     TARGET_SIGUSR1,
 155     TARGET_SIGUSR2,
 156 #ifdef TARGET_SIGPWR
 157     TARGET_SIGPWR,
 158 #else
 159     -1,
 160 #endif
 161     -1, /* SIGPOLL */
 162     -1,
 163     -1,
 164     -1,
 165     -1,
 166     -1,
 167     -1,
 168     -1,
 169     -1,
 170     -1,
 171     -1,
 172     -1,
 173 #ifdef __SIGRTMIN
 174     __SIGRTMIN + 1,
 175     __SIGRTMIN + 2,
 176     __SIGRTMIN + 3,
 177     __SIGRTMIN + 4,
 178     __SIGRTMIN + 5,
 179     __SIGRTMIN + 6,
 180     __SIGRTMIN + 7,
 181     __SIGRTMIN + 8,
 182     __SIGRTMIN + 9,
 183     __SIGRTMIN + 10,
 184     __SIGRTMIN + 11,
 185     __SIGRTMIN + 12,
 186     __SIGRTMIN + 13,
 187     __SIGRTMIN + 14,
 188     __SIGRTMIN + 15,
 189     __SIGRTMIN + 16,
 190     __SIGRTMIN + 17,
 191     __SIGRTMIN + 18,
 192     __SIGRTMIN + 19,
 193     __SIGRTMIN + 20,
 194     __SIGRTMIN + 21,
 195     __SIGRTMIN + 22,
 196     __SIGRTMIN + 23,
 197     __SIGRTMIN + 24,
 198     __SIGRTMIN + 25,
 199     __SIGRTMIN + 26,
 200     __SIGRTMIN + 27,
 201     __SIGRTMIN + 28,
 202     __SIGRTMIN + 29,
 203     __SIGRTMIN + 30,
 204     __SIGRTMIN + 31,
 205     -1, /* SIGCANCEL */
 206     __SIGRTMIN,
 207     __SIGRTMIN + 32,
 208     __SIGRTMIN + 33,
 209     __SIGRTMIN + 34,
 210     __SIGRTMIN + 35,
 211     __SIGRTMIN + 36,
 212     __SIGRTMIN + 37,
 213     __SIGRTMIN + 38,
 214     __SIGRTMIN + 39,
 215     __SIGRTMIN + 40,
 216     __SIGRTMIN + 41,
 217     __SIGRTMIN + 42,
 218     __SIGRTMIN + 43,
 219     __SIGRTMIN + 44,
 220     __SIGRTMIN + 45,
 221     __SIGRTMIN + 46,
 222     __SIGRTMIN + 47,
 223     __SIGRTMIN + 48,
 224     __SIGRTMIN + 49,
 225     __SIGRTMIN + 50,
 226     __SIGRTMIN + 51,
 227     __SIGRTMIN + 52,
 228     __SIGRTMIN + 53,
 229     __SIGRTMIN + 54,
 230     __SIGRTMIN + 55,
 231     __SIGRTMIN + 56,
 232     __SIGRTMIN + 57,
 233     __SIGRTMIN + 58,
 234     __SIGRTMIN + 59,
 235     __SIGRTMIN + 60,
 236     __SIGRTMIN + 61,
 237     __SIGRTMIN + 62,
 238     __SIGRTMIN + 63,
 239     __SIGRTMIN + 64,
 240     __SIGRTMIN + 65,
 241     __SIGRTMIN + 66,
 242     __SIGRTMIN + 67,
 243     __SIGRTMIN + 68,
 244     __SIGRTMIN + 69,
 245     __SIGRTMIN + 70,
 246     __SIGRTMIN + 71,
 247     __SIGRTMIN + 72,
 248     __SIGRTMIN + 73,
 249     __SIGRTMIN + 74,
 250     __SIGRTMIN + 75,
 251     __SIGRTMIN + 76,
 252     __SIGRTMIN + 77,
 253     __SIGRTMIN + 78,
 254     __SIGRTMIN + 79,
 255     __SIGRTMIN + 80,
 256     __SIGRTMIN + 81,
 257     __SIGRTMIN + 82,
 258     __SIGRTMIN + 83,
 259     __SIGRTMIN + 84,
 260     __SIGRTMIN + 85,
 261     __SIGRTMIN + 86,
 262     __SIGRTMIN + 87,
 263     __SIGRTMIN + 88,
 264     __SIGRTMIN + 89,
 265     __SIGRTMIN + 90,
 266     __SIGRTMIN + 91,
 267     __SIGRTMIN + 92,
 268     __SIGRTMIN + 93,
 269     __SIGRTMIN + 94,
 270     __SIGRTMIN + 95,
 271     -1, /* SIGINFO */
 272     -1, /* UNKNOWN */
 273     -1, /* DEFAULT */
 274     -1,
 275     -1,
 276     -1,
 277     -1,
 278     -1,
 279     -1
 280 #endif
 281 };
 282 #else
 283 /* In system mode we only need SIGINT and SIGTRAP; other signals
 284    are not yet supported.  */
 285
 286 enum {
 287     TARGET_SIGINT = 2,
 288     TARGET_SIGTRAP = 5
 289 };
 290
 291 static int gdb_signal_table[] = {
 292     -1,
 293     -1,
 294     TARGET_SIGINT,
 295     -1,
 296     -1,
 297     TARGET_SIGTRAP
 298 };
 299 #endif
 300
 301 #ifdef CONFIG_USER_ONLY
 302 static int target_signal_to_gdb (int sig)
 303 {
 304     int i;
 305     for (i = 0; i < ARRAY_SIZE (gdb_signal_table); i++)
 306         if (gdb_signal_table[i] == sig)
 307             return i;
 308     return GDB_SIGNAL_UNKNOWN;
 309 }
 310 #endif
 311
 312 static int gdb_signal_to_target (int sig)
 313 {
 314     if (sig < ARRAY_SIZE (gdb_signal_table))
 315         return gdb_signal_table[sig];
 316     else
 317         return -1;
 318 }
 319
 320 typedef struct GDBRegisterState {
 321     int base_reg;
 322     int num_regs;
 323     gdb_get_reg_cb get_reg;
 324     gdb_set_reg_cb set_reg;
 325     const char *xml;
 326     struct GDBRegisterState *next;
 327 } GDBRegisterState;
 328
 329 typedef struct GDBProcess {
 330     uint32_t pid;
 331     bool attached;
 332
 333     char target_xml[1024];
 334 } GDBProcess;
 335
 336 enum RSState {
 337     RS_INACTIVE,
 338     RS_IDLE,
 339     RS_GETLINE,
 340     RS_GETLINE_ESC,
 341     RS_GETLINE_RLE,
 342     RS_CHKSUM1,
 343     RS_CHKSUM2,
 344 };
 345 typedef struct GDBState {
 346     bool init;       /* have we been initialised? */
 347     CPUState *c_cpu; /* current CPU for step/continue ops */
 348     CPUState *g_cpu; /* current CPU for other ops */
 349     CPUState *query_cpu; /* for q{f|s}ThreadInfo */
 350     enum RSState state; /* parsing state */
 351     char line_buf[MAX_PACKET_LENGTH];
 352     int line_buf_index;
 353     int line_sum; /* running checksum */
 354     int line_csum; /* checksum at the end of the packet */
 355     GByteArray *last_packet;
 356     int signal;
 357 #ifdef CONFIG_USER_ONLY
 358     int fd;
 359     char *socket_path;
 360     int running_state;
 361 #else
 362     CharBackend chr;
 363     Chardev *mon_chr;
 364 #endif
 365     bool multiprocess;
 366     GDBProcess *processes;
 367     int process_num;
 368     char syscall_buf[256];
 369     gdb_syscall_complete_cb current_syscall_cb;
 370     GString *str_buf;
 371     GByteArray *mem_buf;
 372 } GDBState;
 373
 374 /* By default use no IRQs and no timers while single stepping so as to
 375  * make single stepping like an ICE HW step.
 376  */
 377 static int sstep_flags = SSTEP_ENABLE|SSTEP_NOIRQ|SSTEP_NOTIMER;
 378
 379 /* Retrieves flags for single step mode. */
 380 static int get_sstep_flags(void)
 381 {
 382     /*
 383      * In replay mode all events written into the log should be replayed.
 384      * That is why NOIRQ flag is removed in this mode.
 385      */
 386     if (replay_mode != REPLAY_MODE_NONE) {
 387         return SSTEP_ENABLE;
 388     } else {
 389         return sstep_flags;
 390     }
 391 }
 392
 393 static GDBState gdbserver_state;
 394
 395 static void init_gdbserver_state(void)
 396 {
 397     g_assert(!gdbserver_state.init);
 398     memset(&gdbserver_state, 0, sizeof(GDBState));
 399     gdbserver_state.init = true;
 400     gdbserver_state.str_buf = g_string_new(NULL);
 401     gdbserver_state.mem_buf = g_byte_array_sized_new(MAX_PACKET_LENGTH);
 402     gdbserver_state.last_packet = g_byte_array_sized_new(MAX_PACKET_LENGTH + 4);
 403 }
 404
 405 #ifndef CONFIG_USER_ONLY
 406 static void reset_gdbserver_state(void)
 407 {
 408     g_free(gdbserver_state.processes);
 409     gdbserver_state.processes = NULL;
 410     gdbserver_state.process_num = 0;
 411 }
 412 #endif
 413
 414 bool gdb_has_xml;
 415
 416 #ifdef CONFIG_USER_ONLY
 417
 418 static int get_char(void)
 419 {
 420     uint8_t ch;
 421     int ret;
 422
 423     for(;;) {
 424         ret = qemu_recv(gdbserver_state.fd, &ch, 1, 0);
 425         if (ret < 0) {
 426             if (errno == ECONNRESET)
 427                 gdbserver_state.fd = -1;
 428             if (errno != EINTR)
 429                 return -1;
 430         } else if (ret == 0) {
 431             close(gdbserver_state.fd);
 432             gdbserver_state.fd = -1;
 433             return -1;
 434         } else {
 435             break;
 436         }
 437     }
 438     return ch;
 439 }
 440 #endif
 441
 442 static enum {
 443     GDB_SYS_UNKNOWN,
 444     GDB_SYS_ENABLED,
 445     GDB_SYS_DISABLED,
 446 } gdb_syscall_mode;
 447
 448 /* Decide if either remote gdb syscalls or native file IO should be used. */
 449 int use_gdb_syscalls(void)
 450 {
 451     SemihostingTarget target = semihosting_get_target();
 452     if (target == SEMIHOSTING_TARGET_NATIVE) {
 453         /* -semihosting-config target=native */
 454         return false;
 455     } else if (target == SEMIHOSTING_TARGET_GDB) {
 456         /* -semihosting-config target=gdb */
 457         return true;
 458     }
 459
 460     /* -semihosting-config target=auto */
 461     /* On the first call check if gdb is connected and remember. */
 462     if (gdb_syscall_mode == GDB_SYS_UNKNOWN) {
 463         gdb_syscall_mode = gdbserver_state.init ?
 464             GDB_SYS_ENABLED : GDB_SYS_DISABLED;
 465     }
 466     return gdb_syscall_mode == GDB_SYS_ENABLED;
 467 }
 468
 469 /* Resume execution.  */
 470 static inline void gdb_continue(void)
 471 {
 472
 473 #ifdef CONFIG_USER_ONLY
 474     gdbserver_state.running_state = 1;
 475     trace_gdbstub_op_continue();
 476 #else
 477     if (!runstate_needs_reset()) {
 478         trace_gdbstub_op_continue();
 479         vm_start();
 480     }
 481 #endif
 482 }
 483
 484 /*
 485  * Resume execution, per CPU actions. For user-mode emulation it's
 486  * equivalent to gdb_continue.
 487  */
 488 static int gdb_continue_partial(char *newstates)
 489 {
 490     CPUState *cpu;
 491     int res = 0;
 492 #ifdef CONFIG_USER_ONLY
 493     /*
 494      * This is not exactly accurate, but it's an improvement compared to the
 495      * previous situation, where only one CPU would be single-stepped.
 496      */
 497     CPU_FOREACH(cpu) {
 498         if (newstates[cpu->cpu_index] == 's') {
 499             trace_gdbstub_op_stepping(cpu->cpu_index);
 500             cpu_single_step(cpu, sstep_flags);
 501         }
 502     }
 503     gdbserver_state.running_state = 1;
 504 #else
 505     int flag = 0;
 506
 507     if (!runstate_needs_reset()) {
 508         if (vm_prepare_start()) {
 509             return 0;
 510         }
 511
 512         CPU_FOREACH(cpu) {
 513             switch (newstates[cpu->cpu_index]) {
 514             case 0:
 515             case 1:
 516                 break; /* nothing to do here */
 517             case 's':
 518                 trace_gdbstub_op_stepping(cpu->cpu_index);
 519                 cpu_single_step(cpu, get_sstep_flags());
 520                 cpu_resume(cpu);
 521                 flag = 1;
 522                 break;
 523             case 'c':
 524                 trace_gdbstub_op_continue_cpu(cpu->cpu_index);
 525                 cpu_resume(cpu);
 526                 flag = 1;
 527                 break;
 528             default:
 529                 res = -1;
 530                 break;
 531             }
 532         }
 533     }
 534     if (flag) {
 535         qemu_clock_enable(QEMU_CLOCK_VIRTUAL, true);
 536     }
 537 #endif
 538     return res;
 539 }
 540
 541 static void put_buffer(const uint8_t *buf, int len)
 542 {
 543 #ifdef CONFIG_USER_ONLY
 544     int ret;
 545
 546     while (len > 0) {
 547         ret = send(gdbserver_state.fd, buf, len, 0);
 548         if (ret < 0) {
 549             if (errno != EINTR)
 550                 return;
 551         } else {
 552             buf += ret;
 553             len -= ret;
 554         }
 555     }
 556 #else
 557     /* XXX this blocks entire thread. Rewrite to use
 558      * qemu_chr_fe_write and background I/O callbacks */
 559     qemu_chr_fe_write_all(&gdbserver_state.chr, buf, len);
 560 #endif
 561 }
 562
 563 static inline int fromhex(int v)
 564 {
 565     if (v >= '0' && v <= '9')
 566         return v - '0';
 567     else if (v >= 'A' && v <= 'F')
 568         return v - 'A' + 10;
 569     else if (v >= 'a' && v <= 'f')
 570         return v - 'a' + 10;
 571     else
 572         return 0;
 573 }
 574
 575 static inline int tohex(int v)
 576 {
 577     if (v < 10)
 578         return v + '0';
 579     else
 580         return v - 10 + 'a';
 581 }
 582
 583 /* writes 2*len+1 bytes in buf */
 584 static void memtohex(GString *buf, const uint8_t *mem, int len)
 585 {
 586     int i, c;
 587     for(i = 0; i < len; i++) {
 588         c = mem[i];
 589         g_string_append_c(buf, tohex(c >> 4));
 590         g_string_append_c(buf, tohex(c & 0xf));
 591     }
 592     g_string_append_c(buf, '\0');
 593 }
 594
 595 static void hextomem(GByteArray *mem, const char *buf, int len)
 596 {
 597     int i;
 598
 599     for(i = 0; i < len; i++) {
 600         guint8 byte = fromhex(buf[0]) << 4 | fromhex(buf[1]);
 601         g_byte_array_append(mem, &byte, 1);
 602         buf += 2;
 603     }
 604 }
 605
 606 static void hexdump(const char *buf, int len,
 607                     void (*trace_fn)(size_t ofs, char const *text))
 608 {
 609     char line_buffer[3 * 16 + 4 + 16 + 1];
 610
 611     size_t i;
 612     for (i = 0; i < len || (i & 0xF); ++i) {
 613         size_t byte_ofs = i & 15;
 614
 615         if (byte_ofs == 0) {
 616             memset(line_buffer, ' ', 3 * 16 + 4 + 16);
 617             line_buffer[3 * 16 + 4 + 16] = 0;
 618         }
 619
 620         size_t col_group = (i >> 2) & 3;
 621         size_t hex_col = byte_ofs * 3 + col_group;
 622         size_t txt_col = 3 * 16 + 4 + byte_ofs;
 623
 624         if (i < len) {
 625             char value = buf[i];
 626
 627             line_buffer[hex_col + 0] = tohex((value >> 4) & 0xF);
 628             line_buffer[hex_col + 1] = tohex((value >> 0) & 0xF);
 629             line_buffer[txt_col + 0] = (value >= ' ' && value < 127)
 630                     ? value
 631                     : '.';
 632         }
 633
 634         if (byte_ofs == 0xF)
 635             trace_fn(i & -16, line_buffer);
 636     }
 637 }
 638
 639 /* return -1 if error, 0 if OK */
 640 static int put_packet_binary(const char *buf, int len, bool dump)
 641 {
 642     int csum, i;
 643     uint8_t footer[3];
 644
 645     if (dump && trace_event_get_state_backends(TRACE_GDBSTUB_IO_BINARYREPLY)) {
 646         hexdump(buf, len, trace_gdbstub_io_binaryreply);
 647     }
 648
 649     for(;;) {
 650         g_byte_array_set_size(gdbserver_state.last_packet, 0);
 651         g_byte_array_append(gdbserver_state.last_packet,
 652                             (const uint8_t *) "$", 1);
 653         g_byte_array_append(gdbserver_state.last_packet,
 654                             (const uint8_t *) buf, len);
 655         csum = 0;
 656         for(i = 0; i < len; i++) {
 657             csum += buf[i];
 658         }
 659         footer[0] = '#';
 660         footer[1] = tohex((csum >> 4) & 0xf);
 661         footer[2] = tohex((csum) & 0xf);
 662         g_byte_array_append(gdbserver_state.last_packet, footer, 3);
 663
 664         put_buffer(gdbserver_state.last_packet->data,
 665                    gdbserver_state.last_packet->len);
 666
 667 #ifdef CONFIG_USER_ONLY
 668         i = get_char();
 669         if (i < 0)
 670             return -1;
 671         if (i == '+')
 672             break;
 673 #else
 674         break;
 675 #endif
 676     }
 677     return 0;
 678 }
 679
 680 /* return -1 if error, 0 if OK */
 681 static int put_packet(const char *buf)
 682 {
 683     trace_gdbstub_io_reply(buf);
 684
 685     return put_packet_binary(buf, strlen(buf), false);
 686 }
 687
 688 static void put_strbuf(void)
 689 {
 690     put_packet(gdbserver_state.str_buf->str);
 691 }
 692
 693 /* Encode data using the encoding for 'x' packets.  */
 694 static void memtox(GString *buf, const char *mem, int len)
 695 {
 696     char c;
 697
 698     while (len--) {
 699         c = *(mem++);
 700         switch (c) {
 701         case '#': case '$': case '*': case '}':
 702             g_string_append_c(buf, '}');
 703             g_string_append_c(buf, c ^ 0x20);
 704             break;
 705         default:
 706             g_string_append_c(buf, c);
 707             break;
 708         }
 709     }
 710 }
 711
 712 static uint32_t gdb_get_cpu_pid(CPUState *cpu)
 713 {
 714     /* TODO: In user mode, we should use the task state PID */
 715     if (cpu->cluster_index == UNASSIGNED_CLUSTER_INDEX) {
 716         /* Return the default process' PID */
 717         int index = gdbserver_state.process_num - 1;
 718         return gdbserver_state.processes[index].pid;
 719     }
 720     return cpu->cluster_index + 1;
 721 }
 722
 723 static GDBProcess *gdb_get_process(uint32_t pid)
 724 {
 725     int i;
 726
 727     if (!pid) {
 728         /* 0 means any process, we take the first one */
 729         return &gdbserver_state.processes[0];
 730     }
 731
 732     for (i = 0; i < gdbserver_state.process_num; i++) {
 733         if (gdbserver_state.processes[i].pid == pid) {
 734             return &gdbserver_state.processes[i];
 735         }
 736     }
 737
 738     return NULL;
 739 }
 740
 741 static GDBProcess *gdb_get_cpu_process(CPUState *cpu)
 742 {
 743     return gdb_get_process(gdb_get_cpu_pid(cpu));
 744 }
 745
 746 static CPUState *find_cpu(uint32_t thread_id)
 747 {
 748     CPUState *cpu;
 749
 750     CPU_FOREACH(cpu) {
 751         if (cpu_gdb_index(cpu) == thread_id) {
 752             return cpu;
 753         }
 754     }
 755
 756     return NULL;
 757 }
 758
 759 static CPUState *get_first_cpu_in_process(GDBProcess *process)
 760 {
 761     CPUState *cpu;
 762
 763     CPU_FOREACH(cpu) {
 764         if (gdb_get_cpu_pid(cpu) == process->pid) {
 765             return cpu;
 766         }
 767     }
 768
 769     return NULL;
 770 }
 771
 772 static CPUState *gdb_next_cpu_in_process(CPUState *cpu)
 773 {
 774     uint32_t pid = gdb_get_cpu_pid(cpu);
 775     cpu = CPU_NEXT(cpu);
 776
 777     while (cpu) {
 778         if (gdb_get_cpu_pid(cpu) == pid) {
 779             break;
 780         }
 781
 782         cpu = CPU_NEXT(cpu);
 783     }
 784
 785     return cpu;
 786 }
 787
 788 /* Return the cpu following @cpu, while ignoring unattached processes. */
 789 static CPUState *gdb_next_attached_cpu(CPUState *cpu)
 790 {
 791     cpu = CPU_NEXT(cpu);
 792
 793     while (cpu) {
 794         if (gdb_get_cpu_process(cpu)->attached) {
 795             break;
 796         }
 797
 798         cpu = CPU_NEXT(cpu);
 799     }
 800
 801     return cpu;
 802 }
 803
 804 /* Return the first attached cpu */
 805 static CPUState *gdb_first_attached_cpu(void)
 806 {
 807     CPUState *cpu = first_cpu;
 808     GDBProcess *process = gdb_get_cpu_process(cpu);
 809
 810     if (!process->attached) {
 811         return gdb_next_attached_cpu(cpu);
 812     }
 813
 814     return cpu;
 815 }
 816
 817 static CPUState *gdb_get_cpu(uint32_t pid, uint32_t tid)
 818 {
 819     GDBProcess *process;
 820     CPUState *cpu;
 821
 822     if (!pid && !tid) {
 823         /* 0 means any process/thread, we take the first attached one */
 824         return gdb_first_attached_cpu();
 825     } else if (pid && !tid) {
 826         /* any thread in a specific process */
 827         process = gdb_get_process(pid);
 828
 829         if (process == NULL) {
 830             return NULL;
 831         }
 832
 833         if (!process->attached) {
 834             return NULL;
 835         }
 836
 837         return get_first_cpu_in_process(process);
 838     } else {
 839         /* a specific thread */
 840         cpu = find_cpu(tid);
 841
 842         if (cpu == NULL) {
 843             return NULL;
 844         }
 845
 846         process = gdb_get_cpu_process(cpu);
 847
 848         if (pid && process->pid != pid) {
 849             return NULL;
 850         }
 851
 852         if (!process->attached) {
 853             return NULL;
 854         }
 855
 856         return cpu;
 857     }
 858 }
 859
 860 static const char *get_feature_xml(const char *p, const char **newp,
 861                                    GDBProcess *process)
 862 {
 863     size_t len;
 864     int i;
 865     const char *name;
 866     CPUState *cpu = get_first_cpu_in_process(process);
 867     CPUClass *cc = CPU_GET_CLASS(cpu);
 868
 869     len = 0;
 870     while (p[len] && p[len] != ':')
 871         len++;
 872     *newp = p + len;
 873
 874     name = NULL;
 875     if (strncmp(p, "target.xml", len) == 0) {
 876         char *buf = process->target_xml;
 877         const size_t buf_sz = sizeof(process->target_xml);
 878
 879         /* Generate the XML description for this CPU.  */
 880         if (!buf[0]) {
 881             GDBRegisterState *r;
 882
 883             pstrcat(buf, buf_sz,
 884                     "<?xml version=\"1.0\"?>"
 885                     "<!DOCTYPE target SYSTEM \"gdb-target.dtd\">"
 886                     "<target>");
 887             if (cc->gdb_arch_name) {
 888                 gchar *arch = cc->gdb_arch_name(cpu);
 889                 pstrcat(buf, buf_sz, "<architecture>");
 890                 pstrcat(buf, buf_sz, arch);
 891                 pstrcat(buf, buf_sz, "</architecture>");
 892                 g_free(arch);
 893             }
 894             pstrcat(buf, buf_sz, "<xi:include href=\"");
 895             pstrcat(buf, buf_sz, cc->gdb_core_xml_file);
 896             pstrcat(buf, buf_sz, "\"/>");
 897             for (r = cpu->gdb_regs; r; r = r->next) {
 898                 pstrcat(buf, buf_sz, "<xi:include href=\"");
 899                 pstrcat(buf, buf_sz, r->xml);
 900                 pstrcat(buf, buf_sz, "\"/>");
 901             }
 902             pstrcat(buf, buf_sz, "</target>");
 903         }
 904         return buf;
 905     }
 906     if (cc->gdb_get_dynamic_xml) {
 907         char *xmlname = g_strndup(p, len);
 908         const char *xml = cc->gdb_get_dynamic_xml(cpu, xmlname);
 909
 910         g_free(xmlname);
 911         if (xml) {
 912             return xml;
 913         }
 914     }
 915     for (i = 0; ; i++) {
 916         name = xml_builtin[i][0];
 917         if (!name || (strncmp(name, p, len) == 0 && strlen(name) == len))
 918             break;
 919     }
 920     return name ? xml_builtin[i][1] : NULL;
 921 }
 922
 923 static int gdb_read_register(CPUState *cpu, GByteArray *buf, int reg)
 924 {
 925     CPUClass *cc = CPU_GET_CLASS(cpu);
 926     CPUArchState *env = cpu->env_ptr;
 927     GDBRegisterState *r;
 928
 929     if (reg < cc->gdb_num_core_regs) {
 930         return cc->gdb_read_register(cpu, buf, reg);
 931     }
 932
 933     for (r = cpu->gdb_regs; r; r = r->next) {
 934         if (r->base_reg <= reg && reg < r->base_reg + r->num_regs) {
 935             return r->get_reg(env, buf, reg - r->base_reg);
 936         }
 937     }
 938     return 0;
 939 }
 940
 941 static int gdb_write_register(CPUState *cpu, uint8_t *mem_buf, int reg)
 942 {
 943     CPUClass *cc = CPU_GET_CLASS(cpu);
 944     CPUArchState *env = cpu->env_ptr;
 945     GDBRegisterState *r;
 946
 947     if (reg < cc->gdb_num_core_regs) {
 948         return cc->gdb_write_register(cpu, mem_buf, reg);
 949     }
 950
 951     for (r = cpu->gdb_regs; r; r = r->next) {
 952         if (r->base_reg <= reg && reg < r->base_reg + r->num_regs) {
 953             return r->set_reg(env, mem_buf, reg - r->base_reg);
 954         }
 955     }
 956     return 0;
 957 }
 958
 959 /* Register a supplemental set of CPU registers.  If g_pos is nonzero it
 960    specifies the first register number and these registers are included in
 961    a standard "g" packet.  Direction is relative to gdb, i.e. get_reg is
 962    gdb reading a CPU register, and set_reg is gdb modifying a CPU register.
 963  */
 964
 965 void gdb_register_coprocessor(CPUState *cpu,
 966                               gdb_get_reg_cb get_reg, gdb_set_reg_cb set_reg,
 967                               int num_regs, const char *xml, int g_pos)
 968 {
 969     GDBRegisterState *s;
 970     GDBRegisterState **p;
 971
 972     p = &cpu->gdb_regs;
 973     while (*p) {
 974         /* Check for duplicates.  */
 975         if (strcmp((*p)->xml, xml) == 0)
 976             return;
 977         p = &(*p)->next;
 978     }
 979
 980     s = g_new0(GDBRegisterState, 1);
 981     s->base_reg = cpu->gdb_num_regs;
 982     s->num_regs = num_regs;
 983     s->get_reg = get_reg;
 984     s->set_reg = set_reg;
 985     s->xml = xml;
 986
 987     /* Add to end of list.  */
 988     cpu->gdb_num_regs += num_regs;
 989     *p = s;
 990     if (g_pos) {
 991         if (g_pos != s->base_reg) {
 992             error_report("Error: Bad gdb register numbering for '%s', "
 993                          "expected %d got %d", xml, g_pos, s->base_reg);
 994         } else {
 995             cpu->gdb_num_g_regs = cpu->gdb_num_regs;
 996         }
 997     }
 998 }
 999
1000 #ifndef CONFIG_USER_ONLY
1001 /* Translate GDB watchpoint type to a flags value for cpu_watchpoint_* */
1002 static inline int xlat_gdb_type(CPUState *cpu, int gdbtype)
1003 {
1004     static const int xlat[] = {
1005         [GDB_WATCHPOINT_WRITE]  = BP_GDB | BP_MEM_WRITE,
1006         [GDB_WATCHPOINT_READ]   = BP_GDB | BP_MEM_READ,
1007         [GDB_WATCHPOINT_ACCESS] = BP_GDB | BP_MEM_ACCESS,
1008     };
1009
1010     CPUClass *cc = CPU_GET_CLASS(cpu);
1011     int cputype = xlat[gdbtype];
1012
1013     if (cc->gdb_stop_before_watchpoint) {
1014         cputype |= BP_STOP_BEFORE_ACCESS;
1015     }
1016     return cputype;
1017 }
1018 #endif
1019
1020 static int gdb_breakpoint_insert(int type, target_ulong addr, target_ulong len)
1021 {
1022     CPUState *cpu;
1023     int err = 0;
1024
1025     if (kvm_enabled()) {
1026         return kvm_insert_breakpoint(gdbserver_state.c_cpu, addr, len, type);
1027     }
1028
1029     switch (type) {
1030     case GDB_BREAKPOINT_SW:
1031     case GDB_BREAKPOINT_HW:
1032         CPU_FOREACH(cpu) {
1033             err = cpu_breakpoint_insert(cpu, addr, BP_GDB, NULL);
1034             if (err) {
1035                 break;
1036             }
1037         }
1038         return err;
1039 #ifndef CONFIG_USER_ONLY
1040     case GDB_WATCHPOINT_WRITE:
1041     case GDB_WATCHPOINT_READ:
1042     case GDB_WATCHPOINT_ACCESS:
1043         CPU_FOREACH(cpu) {
1044             err = cpu_watchpoint_insert(cpu, addr, len,
1045                                         xlat_gdb_type(cpu, type), NULL);
1046             if (err) {
1047                 break;
1048             }
1049         }
1050         return err;
1051 #endif
1052     default:
1053         return -ENOSYS;
1054     }
1055 }
1056
1057 static int gdb_breakpoint_remove(int type, target_ulong addr, target_ulong len)
1058 {
1059     CPUState *cpu;
1060     int err = 0;
1061
1062     if (kvm_enabled()) {
1063         return kvm_remove_breakpoint(gdbserver_state.c_cpu, addr, len, type);
1064     }
1065
1066     switch (type) {
1067     case GDB_BREAKPOINT_SW:
1068     case GDB_BREAKPOINT_HW:
1069         CPU_FOREACH(cpu) {
1070             err = cpu_breakpoint_remove(cpu, addr, BP_GDB);
1071             if (err) {
1072                 break;
1073             }
1074         }
1075         return err;
1076 #ifndef CONFIG_USER_ONLY
1077     case GDB_WATCHPOINT_WRITE:
1078     case GDB_WATCHPOINT_READ:
1079     case GDB_WATCHPOINT_ACCESS:
1080         CPU_FOREACH(cpu) {
1081             err = cpu_watchpoint_remove(cpu, addr, len,
1082                                         xlat_gdb_type(cpu, type));
1083             if (err)
1084                 break;
1085         }
1086         return err;
1087 #endif
1088     default:
1089         return -ENOSYS;
1090     }
1091 }
1092
1093 static inline void gdb_cpu_breakpoint_remove_all(CPUState *cpu)
1094 {
1095     cpu_breakpoint_remove_all(cpu, BP_GDB);
1096 #ifndef CONFIG_USER_ONLY
1097     cpu_watchpoint_remove_all(cpu, BP_GDB);
1098 #endif
1099 }
1100
1101 static void gdb_process_breakpoint_remove_all(GDBProcess *p)
1102 {
1103     CPUState *cpu = get_first_cpu_in_process(p);
1104
1105     while (cpu) {
1106         gdb_cpu_breakpoint_remove_all(cpu);
1107         cpu = gdb_next_cpu_in_process(cpu);
1108     }
1109 }
1110
1111 static void gdb_breakpoint_remove_all(void)
1112 {
1113     CPUState *cpu;
1114
1115     if (kvm_enabled()) {
1116         kvm_remove_all_breakpoints(gdbserver_state.c_cpu);
1117         return;
1118     }
1119
1120     CPU_FOREACH(cpu) {
1121         gdb_cpu_breakpoint_remove_all(cpu);
1122     }
1123 }
1124
1125 static void gdb_set_cpu_pc(target_ulong pc)
1126 {
1127     CPUState *cpu = gdbserver_state.c_cpu;
1128
1129     cpu_synchronize_state(cpu);
1130     cpu_set_pc(cpu, pc);
1131 }
1132
1133 static void gdb_append_thread_id(CPUState *cpu, GString *buf)
1134 {
1135     if (gdbserver_state.multiprocess) {
1136         g_string_append_printf(buf, "p%02x.%02x",
1137                                gdb_get_cpu_pid(cpu), cpu_gdb_index(cpu));
1138     } else {
1139         g_string_append_printf(buf, "%02x", cpu_gdb_index(cpu));
1140     }
1141 }
1142
1143 typedef enum GDBThreadIdKind {
1144     GDB_ONE_THREAD = 0,
1145     GDB_ALL_THREADS,     /* One process, all threads */
1146     GDB_ALL_PROCESSES,
1147     GDB_READ_THREAD_ERR
1148 } GDBThreadIdKind;
1149
1150 static GDBThreadIdKind read_thread_id(const char *buf, const char **end_buf,
1151                                       uint32_t *pid, uint32_t *tid)
1152 {
1153     unsigned long p, t;
1154     int ret;
1155
1156     if (*buf == 'p') {
1157         buf++;
1158         ret = qemu_strtoul(buf, &buf, 16, &p);
1159
1160         if (ret) {
1161             return GDB_READ_THREAD_ERR;
1162         }
1163
1164         /* Skip '.' */
1165         buf++;
1166     } else {
1167         p = 1;
1168     }
1169
1170     ret = qemu_strtoul(buf, &buf, 16, &t);
1171
1172     if (ret) {
1173         return GDB_READ_THREAD_ERR;
1174     }
1175
1176     *end_buf = buf;
1177
1178     if (p == -1) {
1179         return GDB_ALL_PROCESSES;
1180     }
1181
1182     if (pid) {
1183         *pid = p;
1184     }
1185
1186     if (t == -1) {
1187         return GDB_ALL_THREADS;
1188     }
1189
1190     if (tid) {
1191         *tid = t;
1192     }
1193
1194     return GDB_ONE_THREAD;
1195 }
1196
1197 /**
1198  * gdb_handle_vcont - Parses and handles a vCont packet.
1199  * returns -ENOTSUP if a command is unsupported, -EINVAL or -ERANGE if there is
1200  *         a format error, 0 on success.
1201  */
1202 static int gdb_handle_vcont(const char *p)
1203 {
1204     int res, signal = 0;
1205     char cur_action;
1206     char *newstates;
1207     unsigned long tmp;
1208     uint32_t pid, tid;
1209     GDBProcess *process;
1210     CPUState *cpu;
1211     GDBThreadIdKind kind;
1212 #ifdef CONFIG_USER_ONLY
1213     int max_cpus = 1; /* global variable max_cpus exists only in system mode */
1214
1215     CPU_FOREACH(cpu) {
1216         max_cpus = max_cpus <= cpu->cpu_index ? cpu->cpu_index + 1 : max_cpus;
1217     }
1218 #else
1219     MachineState *ms = MACHINE(qdev_get_machine());
1220     unsigned int max_cpus = ms->smp.max_cpus;
1221 #endif
1222     /* uninitialised CPUs stay 0 */
1223     newstates = g_new0(char, max_cpus);
1224
1225     /* mark valid CPUs with 1 */
1226     CPU_FOREACH(cpu) {
1227         newstates[cpu->cpu_index] = 1;
1228     }
1229
1230     /*
1231      * res keeps track of what error we are returning, with -ENOTSUP meaning
1232      * that the command is unknown or unsupported, thus returning an empty
1233      * packet, while -EINVAL and -ERANGE cause an E22 packet, due to invalid,
1234      *  or incorrect parameters passed.
1235      */
1236     res = 0;
1237     while (*p) {
1238         if (*p++ != ';') {
1239             res = -ENOTSUP;
1240             goto out;
1241         }
1242
1243         cur_action = *p++;
1244         if (cur_action == 'C' || cur_action == 'S') {
1245             cur_action = qemu_tolower(cur_action);
1246             res = qemu_strtoul(p, &p, 16, &tmp);
1247             if (res) {
1248                 goto out;
1249             }
1250             signal = gdb_signal_to_target(tmp);
1251         } else if (cur_action != 'c' && cur_action != 's') {
1252             /* unknown/invalid/unsupported command */
1253             res = -ENOTSUP;
1254             goto out;
1255         }
1256
1257         if (*p == '\0' || *p == ';') {
1258             /*
1259              * No thread specifier, action is on "all threads". The
1260              * specification is unclear regarding the process to act on. We
1261              * choose all processes.
1262              */
1263             kind = GDB_ALL_PROCESSES;
1264         } else if (*p++ == ':') {
1265             kind = read_thread_id(p, &p, &pid, &tid);
1266         } else {
1267             res = -ENOTSUP;
1268             goto out;
1269         }
1270
1271         switch (kind) {
1272         case GDB_READ_THREAD_ERR:
1273             res = -EINVAL;
1274             goto out;
1275
1276         case GDB_ALL_PROCESSES:
1277             cpu = gdb_first_attached_cpu();
1278             while (cpu) {
1279                 if (newstates[cpu->cpu_index] == 1) {
1280                     newstates[cpu->cpu_index] = cur_action;
1281                 }
1282
1283                 cpu = gdb_next_attached_cpu(cpu);
1284             }
1285             break;
1286
1287         case GDB_ALL_THREADS:
1288             process = gdb_get_process(pid);
1289
1290             if (!process->attached) {
1291                 res = -EINVAL;
1292                 goto out;
1293             }
1294
1295             cpu = get_first_cpu_in_process(process);
1296             while (cpu) {
1297                 if (newstates[cpu->cpu_index] == 1) {
1298                     newstates[cpu->cpu_index] = cur_action;
1299                 }
1300
1301                 cpu = gdb_next_cpu_in_process(cpu);
1302             }
1303             break;
1304
1305         case GDB_ONE_THREAD:
1306             cpu = gdb_get_cpu(pid, tid);
1307
1308             /* invalid CPU/thread specified */
1309             if (!cpu) {
1310                 res = -EINVAL;
1311                 goto out;
1312             }
1313
1314             /* only use if no previous match occourred */
1315             if (newstates[cpu->cpu_index] == 1) {
1316                 newstates[cpu->cpu_index] = cur_action;
1317             }
1318             break;
1319         }
1320     }
1321     gdbserver_state.signal = signal;
1322     gdb_continue_partial(newstates);
1323
1324 out:
1325     g_free(newstates);
1326
1327     return res;
1328 }
1329
1330 typedef union GdbCmdVariant {
1331     const char *data;
1332     uint8_t opcode;
1333     unsigned long val_ul;
1334     unsigned long long val_ull;
1335     struct {
1336         GDBThreadIdKind kind;
1337         uint32_t pid;
1338         uint32_t tid;
1339     } thread_id;
1340 } GdbCmdVariant;
1341
1342 static const char *cmd_next_param(const char *param, const char delimiter)
1343 {
1344     static const char all_delimiters[] = ",;:=";
1345     char curr_delimiters[2] = {0};
1346     const char *delimiters;
1347
1348     if (delimiter == '?') {
1349         delimiters = all_delimiters;
1350     } else if (delimiter == '0') {
1351         return strchr(param, '\0');
1352     } else if (delimiter == '.' && *param) {
1353         return param + 1;
1354     } else {
1355         curr_delimiters[0] = delimiter;
1356         delimiters = curr_delimiters;
1357     }
1358
1359     param += strcspn(param, delimiters);
1360     if (*param) {
1361         param++;
1362     }
1363     return param;
1364 }
1365
1366 static int cmd_parse_params(const char *data, const char *schema,
1367                             GdbCmdVariant *params, int *num_params)
1368 {
1369     int curr_param;
1370     const char *curr_schema, *curr_data;
1371
1372     *num_params = 0;
1373
1374     if (!schema) {
1375         return 0;
1376     }
1377
1378     curr_schema = schema;
1379     curr_param = 0;
1380     curr_data = data;
1381     while (curr_schema[0] && curr_schema[1] && *curr_data) {
1382         switch (curr_schema[0]) {
1383         case 'l':
1384             if (qemu_strtoul(curr_data, &curr_data, 16,
1385                              &params[curr_param].val_ul)) {
1386                 return -EINVAL;
1387             }
1388             curr_param++;
1389             curr_data = cmd_next_param(curr_data, curr_schema[1]);
1390             break;
1391         case 'L':
1392             if (qemu_strtou64(curr_data, &curr_data, 16,
1393                               (uint64_t *)&params[curr_param].val_ull)) {
1394                 return -EINVAL;
1395             }
1396             curr_param++;
1397             curr_data = cmd_next_param(curr_data, curr_schema[1]);
1398             break;
1399         case 's':
1400             params[curr_param].data = curr_data;
1401             curr_param++;
1402             curr_data = cmd_next_param(curr_data, curr_schema[1]);
1403             break;
1404         case 'o':
1405             params[curr_param].opcode = *(uint8_t *)curr_data;
1406             curr_param++;
1407             curr_data = cmd_next_param(curr_data, curr_schema[1]);
1408             break;
1409         case 't':
1410             params[curr_param].thread_id.kind =
1411                 read_thread_id(curr_data, &curr_data,
1412                                &params[curr_param].thread_id.pid,
1413                                &params[curr_param].thread_id.tid);
1414             curr_param++;
1415             curr_data = cmd_next_param(curr_data, curr_schema[1]);
1416             break;
1417         case '?':
1418             curr_data = cmd_next_param(curr_data, curr_schema[1]);
1419             break;
1420         default:
1421             return -EINVAL;
1422         }
1423         curr_schema += 2;
1424     }
1425
1426     *num_params = curr_param;
1427     return 0;
1428 }
1429
1430 typedef struct GdbCmdContext {
1431     GdbCmdVariant *params;
1432     int num_params;
1433 } GdbCmdContext;
1434
1435 typedef void (*GdbCmdHandler)(GdbCmdContext *gdb_ctx, void *user_ctx);
1436
1437 /*
1438  * cmd_startswith -> cmd is compared using startswith
1439  *
1440  *
1441  * schema definitions:
1442  * Each schema parameter entry consists of 2 chars,
1443  * the first char represents the parameter type handling
1444  * the second char represents the delimiter for the next parameter
1445  *
1446  * Currently supported schema types:
1447  * 'l' -> unsigned long (stored in .val_ul)
1448  * 'L' -> unsigned long long (stored in .val_ull)
1449  * 's' -> string (stored in .data)
1450  * 'o' -> single char (stored in .opcode)
1451  * 't' -> thread id (stored in .thread_id)
1452  * '?' -> skip according to delimiter
1453  *
1454  * Currently supported delimiters:
1455  * '?' -> Stop at any delimiter (",;:=\0")
1456  * '0' -> Stop at "\0"
1457  * '.' -> Skip 1 char unless reached "\0"
1458  * Any other value is treated as the delimiter value itself
1459  */
1460 typedef struct GdbCmdParseEntry {
1461     GdbCmdHandler handler;
1462     const char *cmd;
1463     bool cmd_startswith;
1464     const char *schema;
1465 } GdbCmdParseEntry;
1466
1467 static inline int startswith(const char *string, const char *pattern)
1468 {
1469   return !strncmp(string, pattern, strlen(pattern));
1470 }
1471
1472 static int process_string_cmd(void *user_ctx, const char *data,
1473                               const GdbCmdParseEntry *cmds, int num_cmds)
1474 {
1475     int i, schema_len, max_num_params = 0;
1476     GdbCmdContext gdb_ctx;
1477
1478     if (!cmds) {
1479         return -1;
1480     }
1481
1482     for (i = 0; i < num_cmds; i++) {
1483         const GdbCmdParseEntry *cmd = &cmds[i];
1484         g_assert(cmd->handler && cmd->cmd);
1485
1486         if ((cmd->cmd_startswith && !startswith(data, cmd->cmd)) ||
1487             (!cmd->cmd_startswith && strcmp(cmd->cmd, data))) {
1488             continue;
1489         }
1490
1491         if (cmd->schema) {
1492             schema_len = strlen(cmd->schema);
1493             if (schema_len % 2) {
1494                 return -2;
1495             }
1496
1497             max_num_params = schema_len / 2;
1498         }
1499
1500         gdb_ctx.params =
1501             (GdbCmdVariant *)alloca(sizeof(*gdb_ctx.params) * max_num_params);
1502         memset(gdb_ctx.params, 0, sizeof(*gdb_ctx.params) * max_num_params);
1503
1504         if (cmd_parse_params(&data[strlen(cmd->cmd)], cmd->schema,
1505                              gdb_ctx.params, &gdb_ctx.num_params)) {
1506             return -1;
1507         }
1508
1509         cmd->handler(&gdb_ctx, user_ctx);
1510         return 0;
1511     }
1512
1513     return -1;
1514 }
1515
1516 static void run_cmd_parser(const char *data, const GdbCmdParseEntry *cmd)
1517 {
1518     if (!data) {
1519         return;
1520     }
1521
1522     g_string_set_size(gdbserver_state.str_buf, 0);
1523     g_byte_array_set_size(gdbserver_state.mem_buf, 0);
1524
1525     /* In case there was an error during the command parsing we must
1526     * send a NULL packet to indicate the command is not supported */
1527     if (process_string_cmd(NULL, data, cmd, 1)) {
1528         put_packet("");
1529     }
1530 }
1531
1532 static void handle_detach(GdbCmdContext *gdb_ctx, void *user_ctx)
1533 {
1534     GDBProcess *process;
1535     uint32_t pid = 1;
1536
1537     if (gdbserver_state.multiprocess) {
1538         if (!gdb_ctx->num_params) {
1539             put_packet("E22");
1540             return;
1541         }
1542
1543         pid = gdb_ctx->params[0].val_ul;
1544     }
1545
1546     process = gdb_get_process(pid);
1547     gdb_process_breakpoint_remove_all(process);
1548     process->attached = false;
1549
1550     if (pid == gdb_get_cpu_pid(gdbserver_state.c_cpu)) {
1551         gdbserver_state.c_cpu = gdb_first_attached_cpu();
1552     }
1553
1554     if (pid == gdb_get_cpu_pid(gdbserver_state.g_cpu)) {
1555         gdbserver_state.g_cpu = gdb_first_attached_cpu();
1556     }
1557
1558     if (!gdbserver_state.c_cpu) {
1559         /* No more process attached */
1560         gdb_syscall_mode = GDB_SYS_DISABLED;
1561         gdb_continue();
1562     }
1563     put_packet("OK");
1564 }
1565
1566 static void handle_thread_alive(GdbCmdContext *gdb_ctx, void *user_ctx)
1567 {
1568     CPUState *cpu;
1569
1570     if (!gdb_ctx->num_params) {
1571         put_packet("E22");
1572         return;
1573     }
1574
1575     if (gdb_ctx->params[0].thread_id.kind == GDB_READ_THREAD_ERR) {
1576         put_packet("E22");
1577         return;
1578     }
1579
1580     cpu = gdb_get_cpu(gdb_ctx->params[0].thread_id.pid,
1581                       gdb_ctx->params[0].thread_id.tid);
1582     if (!cpu) {
1583         put_packet("E22");
1584         return;
1585     }
1586
1587     put_packet("OK");
1588 }
1589
1590 static void handle_continue(GdbCmdContext *gdb_ctx, void *user_ctx)
1591 {
1592     if (gdb_ctx->num_params) {
1593         gdb_set_cpu_pc(gdb_ctx->params[0].val_ull);
1594     }
1595
1596     gdbserver_state.signal = 0;
1597     gdb_continue();
1598 }
1599
1600 static void handle_cont_with_sig(GdbCmdContext *gdb_ctx, void *user_ctx)
1601 {
1602     unsigned long signal = 0;
1603
1604     /*
1605      * Note: C sig;[addr] is currently unsupported and we simply
1606      *       omit the addr parameter
1607      */
1608     if (gdb_ctx->num_params) {
1609         signal = gdb_ctx->params[0].val_ul;
1610     }
1611
1612     gdbserver_state.signal = gdb_signal_to_target(signal);
1613     if (gdbserver_state.signal == -1) {
1614         gdbserver_state.signal = 0;
1615     }
1616     gdb_continue();
1617 }
1618
1619 static void handle_set_thread(GdbCmdContext *gdb_ctx, void *user_ctx)
1620 {
1621     CPUState *cpu;
1622
1623     if (gdb_ctx->num_params != 2) {
1624         put_packet("E22");
1625         return;
1626     }
1627
1628     if (gdb_ctx->params[1].thread_id.kind == GDB_READ_THREAD_ERR) {
1629         put_packet("E22");
1630         return;
1631     }
1632
1633     if (gdb_ctx->params[1].thread_id.kind != GDB_ONE_THREAD) {
1634         put_packet("OK");
1635         return;
1636     }
1637
1638     cpu = gdb_get_cpu(gdb_ctx->params[1].thread_id.pid,
1639                       gdb_ctx->params[1].thread_id.tid);
1640     if (!cpu) {
1641         put_packet("E22");
1642         return;
1643     }
1644
1645     /*
1646      * Note: This command is deprecated and modern gdb's will be using the
1647      *       vCont command instead.
1648      */
1649     switch (gdb_ctx->params[0].opcode) {
1650     case 'c':
1651         gdbserver_state.c_cpu = cpu;
1652         put_packet("OK");
1653         break;
1654     case 'g':
1655         gdbserver_state.g_cpu = cpu;
1656         put_packet("OK");
1657         break;
1658     default:
1659         put_packet("E22");
1660         break;
1661     }
1662 }
1663
1664 static void handle_insert_bp(GdbCmdContext *gdb_ctx, void *user_ctx)
1665 {
1666     int res;
1667
1668     if (gdb_ctx->num_params != 3) {
1669         put_packet("E22");
1670         return;
1671     }
1672
1673     res = gdb_breakpoint_insert(gdb_ctx->params[0].val_ul,
1674                                 gdb_ctx->params[1].val_ull,
1675                                 gdb_ctx->params[2].val_ull);
1676     if (res >= 0) {
1677         put_packet("OK");
1678         return;
1679     } else if (res == -ENOSYS) {
1680         put_packet("");
1681         return;
1682     }
1683
1684     put_packet("E22");
1685 }
1686
1687 static void handle_remove_bp(GdbCmdContext *gdb_ctx, void *user_ctx)
1688 {
1689     int res;
1690
1691     if (gdb_ctx->num_params != 3) {
1692         put_packet("E22");
1693         return;
1694     }
1695
1696     res = gdb_breakpoint_remove(gdb_ctx->params[0].val_ul,
1697                                 gdb_ctx->params[1].val_ull,
1698                                 gdb_ctx->params[2].val_ull);
1699     if (res >= 0) {
1700         put_packet("OK");
1701         return;
1702     } else if (res == -ENOSYS) {
1703         put_packet("");
1704         return;
1705     }
1706
1707     put_packet("E22");
1708 }
1709
1710 /*
1711  * handle_set/get_reg
1712  *
1713  * Older gdb are really dumb, and don't use 'G/g' if 'P/p' is available.
1714  * This works, but can be very slow. Anything new enough to understand
1715  * XML also knows how to use this properly. However to use this we
1716  * need to define a local XML file as well as be talking to a
1717  * reasonably modern gdb. Responding with an empty packet will cause
1718  * the remote gdb to fallback to older methods.
1719  */
1720
1721 static void handle_set_reg(GdbCmdContext *gdb_ctx, void *user_ctx)
1722 {
1723     int reg_size;
1724
1725     if (!gdb_has_xml) {
1726         put_packet("");
1727         return;
1728     }
1729
1730     if (gdb_ctx->num_params != 2) {
1731         put_packet("E22");
1732         return;
1733     }
1734
1735     reg_size = strlen(gdb_ctx->params[1].data) / 2;
1736     hextomem(gdbserver_state.mem_buf, gdb_ctx->params[1].data, reg_size);
1737     gdb_write_register(gdbserver_state.g_cpu, gdbserver_state.mem_buf->data,
1738                        gdb_ctx->params[0].val_ull);
1739     put_packet("OK");
1740 }
1741
1742 static void handle_get_reg(GdbCmdContext *gdb_ctx, void *user_ctx)
1743 {
1744     int reg_size;
1745
1746     if (!gdb_has_xml) {
1747         put_packet("");
1748         return;
1749     }
1750
1751     if (!gdb_ctx->num_params) {
1752         put_packet("E14");
1753         return;
1754     }
1755
1756     reg_size = gdb_read_register(gdbserver_state.g_cpu,
1757                                  gdbserver_state.mem_buf,
1758                                  gdb_ctx->params[0].val_ull);
1759     if (!reg_size) {
1760         put_packet("E14");
1761         return;
1762     } else {
1763         g_byte_array_set_size(gdbserver_state.mem_buf, reg_size);
1764     }
1765
1766     memtohex(gdbserver_state.str_buf, gdbserver_state.mem_buf->data, reg_size);
1767     put_strbuf();
1768 }
1769
1770 static void handle_write_mem(GdbCmdContext *gdb_ctx, void *user_ctx)
1771 {
1772     if (gdb_ctx->num_params != 3) {
1773         put_packet("E22");
1774         return;
1775     }
1776
1777     /* hextomem() reads 2*len bytes */
1778     if (gdb_ctx->params[1].val_ull > strlen(gdb_ctx->params[2].data) / 2) {
1779         put_packet("E22");
1780         return;
1781     }
1782
1783     hextomem(gdbserver_state.mem_buf, gdb_ctx->params[2].data,
1784              gdb_ctx->params[1].val_ull);
1785     if (target_memory_rw_debug(gdbserver_state.g_cpu, gdb_ctx->params[0].val_ull,
1786                                gdbserver_state.mem_buf->data,
1787                                gdbserver_state.mem_buf->len, true)) {
1788         put_packet("E14");
1789         return;
1790     }
1791
1792     put_packet("OK");
1793 }
1794
1795 static void handle_read_mem(GdbCmdContext *gdb_ctx, void *user_ctx)
1796 {
1797     if (gdb_ctx->num_params != 2) {
1798         put_packet("E22");
1799         return;
1800     }
1801
1802     /* memtohex() doubles the required space */
1803     if (gdb_ctx->params[1].val_ull > MAX_PACKET_LENGTH / 2) {
1804         put_packet("E22");
1805         return;
1806     }
1807
1808     g_byte_array_set_size(gdbserver_state.mem_buf, gdb_ctx->params[1].val_ull);
1809
1810     if (target_memory_rw_debug(gdbserver_state.g_cpu, gdb_ctx->params[0].val_ull,
1811                                gdbserver_state.mem_buf->data,
1812                                gdbserver_state.mem_buf->len, false)) {
1813         put_packet("E14");
1814         return;
1815     }
1816
1817     memtohex(gdbserver_state.str_buf, gdbserver_state.mem_buf->data,
1818              gdbserver_state.mem_buf->len);
1819     put_strbuf();
1820 }
1821
1822 static void handle_write_all_regs(GdbCmdContext *gdb_ctx, void *user_ctx)
1823 {
1824     target_ulong addr, len;
1825     uint8_t *registers;
1826     int reg_size;
1827
1828     if (!gdb_ctx->num_params) {
1829         return;
1830     }
1831
1832     cpu_synchronize_state(gdbserver_state.g_cpu);
1833     len = strlen(gdb_ctx->params[0].data) / 2;
1834     hextomem(gdbserver_state.mem_buf, gdb_ctx->params[0].data, len);
1835     registers = gdbserver_state.mem_buf->data;
1836     for (addr = 0; addr < gdbserver_state.g_cpu->gdb_num_g_regs && len > 0;
1837          addr++) {
1838         reg_size = gdb_write_register(gdbserver_state.g_cpu, registers, addr);
1839         len -= reg_size;
1840         registers += reg_size;
1841     }
1842     put_packet("OK");
1843 }
1844
1845 static void handle_read_all_regs(GdbCmdContext *gdb_ctx, void *user_ctx)
1846 {
1847     target_ulong addr, len;
1848
1849     cpu_synchronize_state(gdbserver_state.g_cpu);
1850     g_byte_array_set_size(gdbserver_state.mem_buf, 0);
1851     len = 0;
1852     for (addr = 0; addr < gdbserver_state.g_cpu->gdb_num_g_regs; addr++) {
1853         len += gdb_read_register(gdbserver_state.g_cpu,
1854                                  gdbserver_state.mem_buf,
1855                                  addr);
1856     }
1857     g_assert(len == gdbserver_state.mem_buf->len);
1858
1859     memtohex(gdbserver_state.str_buf, gdbserver_state.mem_buf->data, len);
1860     put_strbuf();
1861 }
1862
1863 static void handle_file_io(GdbCmdContext *gdb_ctx, void *user_ctx)
1864 {
1865     if (gdb_ctx->num_params >= 1 && gdbserver_state.current_syscall_cb) {
1866         target_ulong ret, err;
1867
1868         ret = (target_ulong)gdb_ctx->params[0].val_ull;
1869         if (gdb_ctx->num_params >= 2) {
1870             err = (target_ulong)gdb_ctx->params[1].val_ull;
1871         } else {
1872             err = 0;
1873         }
1874         gdbserver_state.current_syscall_cb(gdbserver_state.c_cpu, ret, err);
1875         gdbserver_state.current_syscall_cb = NULL;
1876     }
1877
1878     if (gdb_ctx->num_params >= 3 && gdb_ctx->params[2].opcode == (uint8_t)'C') {
1879         put_packet("T02");
1880         return;
1881     }
1882
1883     gdb_continue();
1884 }
1885
1886 static void handle_step(GdbCmdContext *gdb_ctx, void *user_ctx)
1887 {
1888     if (gdb_ctx->num_params) {
1889         gdb_set_cpu_pc((target_ulong)gdb_ctx->params[0].val_ull);
1890     }
1891
1892     cpu_single_step(gdbserver_state.c_cpu, get_sstep_flags());
1893     gdb_continue();
1894 }
1895
1896 static void handle_backward(GdbCmdContext *gdb_ctx, void *user_ctx)
1897 {
1898     if (replay_mode != REPLAY_MODE_PLAY) {
1899         put_packet("E22");
1900     }
1901     if (gdb_ctx->num_params == 1) {
1902         switch (gdb_ctx->params[0].opcode) {
1903         case 's':
1904             if (replay_reverse_step()) {
1905                 gdb_continue();
1906             } else {
1907                 put_packet("E14");
1908             }
1909             return;
1910         case 'c':
1911             if (replay_reverse_continue()) {
1912                 gdb_continue();
1913             } else {
1914                 put_packet("E14");
1915             }
1916             return;
1917         }
1918     }
1919
1920     /* Default invalid command */
1921     put_packet("");
1922 }
1923
1924 static void handle_v_cont_query(GdbCmdContext *gdb_ctx, void *user_ctx)
1925 {
1926     put_packet("vCont;c;C;s;S");
1927 }
1928
1929 static void handle_v_cont(GdbCmdContext *gdb_ctx, void *user_ctx)
1930 {
1931     int res;
1932
1933     if (!gdb_ctx->num_params) {
1934         return;
1935     }
1936
1937     res = gdb_handle_vcont(gdb_ctx->params[0].data);
1938     if ((res == -EINVAL) || (res == -ERANGE)) {
1939         put_packet("E22");
1940     } else if (res) {
1941         put_packet("");
1942     }
1943 }
1944
1945 static void handle_v_attach(GdbCmdContext *gdb_ctx, void *user_ctx)
1946 {
1947     GDBProcess *process;
1948     CPUState *cpu;
1949
1950     g_string_assign(gdbserver_state.str_buf, "E22");
1951     if (!gdb_ctx->num_params) {
1952         goto cleanup;
1953     }
1954
1955     process = gdb_get_process(gdb_ctx->params[0].val_ul);
1956     if (!process) {
1957         goto cleanup;
1958     }
1959
1960     cpu = get_first_cpu_in_process(process);
1961     if (!cpu) {
1962         goto cleanup;
1963     }
1964
1965     process->attached = true;
1966     gdbserver_state.g_cpu = cpu;
1967     gdbserver_state.c_cpu = cpu;
1968
1969     g_string_printf(gdbserver_state.str_buf, "T%02xthread:", GDB_SIGNAL_TRAP);
1970     gdb_append_thread_id(cpu, gdbserver_state.str_buf);
1971     g_string_append_c(gdbserver_state.str_buf, ';');
1972 cleanup:
1973     put_strbuf();
1974 }
1975
1976 static void handle_v_kill(GdbCmdContext *gdb_ctx, void *user_ctx)
1977 {
1978     /* Kill the target */
1979     put_packet("OK");
1980     error_report("QEMU: Terminated via GDBstub");
1981     exit(0);
1982 }
1983
1984 static GdbCmdParseEntry gdb_v_commands_table[] = {
1985     /* Order is important if has same prefix */
1986     {
1987         .handler = handle_v_cont_query,
1988         .cmd = "Cont?",
1989         .cmd_startswith = 1
1990     },
1991     {
1992         .handler = handle_v_cont,
1993         .cmd = "Cont",
1994         .cmd_startswith = 1,
1995         .schema = "s0"
1996     },
1997     {
1998         .handler = handle_v_attach,
1999         .cmd = "Attach;",
2000         .cmd_startswith = 1,
2001         .schema = "l0"
2002     },
2003     {
2004         .handler = handle_v_kill,
2005         .cmd = "Kill;",
2006         .cmd_startswith = 1
2007     },
2008 };
2009
2010 static void handle_v_commands(GdbCmdContext *gdb_ctx, void *user_ctx)
2011 {
2012     if (!gdb_ctx->num_params) {
2013         return;
2014     }
2015
2016     if (process_string_cmd(NULL, gdb_ctx->params[0].data,
2017                            gdb_v_commands_table,
2018                            ARRAY_SIZE(gdb_v_commands_table))) {
2019         put_packet("");
2020     }
2021 }
2022
2023 static void handle_query_qemu_sstepbits(GdbCmdContext *gdb_ctx, void *user_ctx)
2024 {
2025     g_string_printf(gdbserver_state.str_buf, "ENABLE=%x,NOIRQ=%x,NOTIMER=%x",
2026                     SSTEP_ENABLE, SSTEP_NOIRQ, SSTEP_NOTIMER);
2027     put_strbuf();
2028 }
2029
2030 static void handle_set_qemu_sstep(GdbCmdContext *gdb_ctx, void *user_ctx)
2031 {
2032     if (!gdb_ctx->num_params) {
2033         return;
2034     }
2035
2036     sstep_flags = gdb_ctx->params[0].val_ul;
2037     put_packet("OK");
2038 }
2039
2040 static void handle_query_qemu_sstep(GdbCmdContext *gdb_ctx, void *user_ctx)
2041 {
2042     g_string_printf(gdbserver_state.str_buf, "0x%x", sstep_flags);
2043     put_strbuf();
2044 }
2045
2046 static void handle_query_curr_tid(GdbCmdContext *gdb_ctx, void *user_ctx)
2047 {
2048     CPUState *cpu;
2049     GDBProcess *process;
2050
2051     /*
2052      * "Current thread" remains vague in the spec, so always return
2053      * the first thread of the current process (gdb returns the
2054      * first thread).
2055      */
2056     process = gdb_get_cpu_process(gdbserver_state.g_cpu);
2057     cpu = get_first_cpu_in_process(process);
2058     g_string_assign(gdbserver_state.str_buf, "QC");
2059     gdb_append_thread_id(cpu, gdbserver_state.str_buf);
2060     put_strbuf();
2061 }
2062
2063 static void handle_query_threads(GdbCmdContext *gdb_ctx, void *user_ctx)
2064 {
2065     if (!gdbserver_state.query_cpu) {
2066         put_packet("l");
2067         return;
2068     }
2069
2070     g_string_assign(gdbserver_state.str_buf, "m");
2071     gdb_append_thread_id(gdbserver_state.query_cpu, gdbserver_state.str_buf);
2072     put_strbuf();
2073     gdbserver_state.query_cpu = gdb_next_attached_cpu(gdbserver_state.query_cpu);
2074 }
2075
2076 static void handle_query_first_threads(GdbCmdContext *gdb_ctx, void *user_ctx)
2077 {
2078     gdbserver_state.query_cpu = gdb_first_attached_cpu();
2079     handle_query_threads(gdb_ctx, user_ctx);
2080 }
2081
2082 static void handle_query_thread_extra(GdbCmdContext *gdb_ctx, void *user_ctx)
2083 {
2084     g_autoptr(GString) rs = g_string_new(NULL);
2085     CPUState *cpu;
2086
2087     if (!gdb_ctx->num_params ||
2088         gdb_ctx->params[0].thread_id.kind == GDB_READ_THREAD_ERR) {
2089         put_packet("E22");
2090         return;
2091     }
2092
2093     cpu = gdb_get_cpu(gdb_ctx->params[0].thread_id.pid,
2094                       gdb_ctx->params[0].thread_id.tid);
2095     if (!cpu) {
2096         return;
2097     }
2098
2099     cpu_synchronize_state(cpu);
2100
2101     if (gdbserver_state.multiprocess && (gdbserver_state.process_num > 1)) {
2102         /* Print the CPU model and name in multiprocess mode */
2103         ObjectClass *oc = object_get_class(OBJECT(cpu));
2104         const char *cpu_model = object_class_get_name(oc);
2105         const char *cpu_name =
2106             object_get_canonical_path_component(OBJECT(cpu));
2107         g_string_printf(rs, "%s %s [%s]", cpu_model, cpu_name,
2108                         cpu->halted ? "halted " : "running");
2109     } else {
2110         g_string_printf(rs, "CPU#%d [%s]", cpu->cpu_index,
2111                         cpu->halted ? "halted " : "running");
2112     }
2113     trace_gdbstub_op_extra_info(rs->str);
2114     memtohex(gdbserver_state.str_buf, (uint8_t *)rs->str, rs->len);
2115     put_strbuf();
2116 }
2117
2118 #ifdef CONFIG_USER_ONLY
2119 static void handle_query_offsets(GdbCmdContext *gdb_ctx, void *user_ctx)
2120 {
2121     TaskState *ts;
2122
2123     ts = gdbserver_state.c_cpu->opaque;
2124     g_string_printf(gdbserver_state.str_buf,
2125                     "Text=" TARGET_ABI_FMT_lx
2126                     ";Data=" TARGET_ABI_FMT_lx
2127                     ";Bss=" TARGET_ABI_FMT_lx,
2128                     ts->info->code_offset,
2129                     ts->info->data_offset,
2130                     ts->info->data_offset);
2131     put_strbuf();
2132 }
2133 #else
2134 static void handle_query_rcmd(GdbCmdContext *gdb_ctx, void *user_ctx)
2135 {
2136     const guint8 zero = 0;
2137     int len;
2138
2139     if (!gdb_ctx->num_params) {
2140         put_packet("E22");
2141         return;
2142     }
2143
2144     len = strlen(gdb_ctx->params[0].data);
2145     if (len % 2) {
2146         put_packet("E01");
2147         return;
2148     }
2149
2150     g_assert(gdbserver_state.mem_buf->len == 0);
2151     len = len / 2;
2152     hextomem(gdbserver_state.mem_buf, gdb_ctx->params[0].data, len);
2153     g_byte_array_append(gdbserver_state.mem_buf, &zero, 1);
2154     qemu_chr_be_write(gdbserver_state.mon_chr, gdbserver_state.mem_buf->data,
2155                       gdbserver_state.mem_buf->len);
2156     put_packet("OK");
2157 }
2158 #endif
2159
2160 static void handle_query_supported(GdbCmdContext *gdb_ctx, void *user_ctx)
2161 {
2162     CPUClass *cc;
2163
2164     g_string_printf(gdbserver_state.str_buf, "PacketSize=%x", MAX_PACKET_LENGTH);
2165     cc = CPU_GET_CLASS(first_cpu);
2166     if (cc->gdb_core_xml_file) {
2167         g_string_append(gdbserver_state.str_buf, ";qXfer:features:read+");
2168     }
2169
2170     if (replay_mode == REPLAY_MODE_PLAY) {
2171         g_string_append(gdbserver_state.str_buf,
2172             ";ReverseStep+;ReverseContinue+");
2173     }
2174
2175 #ifdef CONFIG_USER_ONLY
2176     if (gdbserver_state.c_cpu->opaque) {
2177         g_string_append(gdbserver_state.str_buf, ";qXfer:auxv:read+");
2178     }
2179 #endif
2180
2181     if (gdb_ctx->num_params &&
2182         strstr(gdb_ctx->params[0].data, "multiprocess+")) {
2183         gdbserver_state.multiprocess = true;
2184     }
2185
2186     g_string_append(gdbserver_state.str_buf, ";vContSupported+;multiprocess+");
2187     put_strbuf();
2188 }
2189
2190 static void handle_query_xfer_features(GdbCmdContext *gdb_ctx, void *user_ctx)
2191 {
2192     GDBProcess *process;
2193     CPUClass *cc;
2194     unsigned long len, total_len, addr;
2195     const char *xml;
2196     const char *p;
2197
2198     if (gdb_ctx->num_params < 3) {
2199         put_packet("E22");
2200         return;
2201     }
2202
2203     process = gdb_get_cpu_process(gdbserver_state.g_cpu);
2204     cc = CPU_GET_CLASS(gdbserver_state.g_cpu);
2205     if (!cc->gdb_core_xml_file) {
2206         put_packet("");
2207         return;
2208     }
2209
2210     gdb_has_xml = true;
2211     p = gdb_ctx->params[0].data;
2212     xml = get_feature_xml(p, &p, process);
2213     if (!xml) {
2214         put_packet("E00");
2215         return;
2216     }
2217
2218     addr = gdb_ctx->params[1].val_ul;
2219     len = gdb_ctx->params[2].val_ul;
2220     total_len = strlen(xml);
2221     if (addr > total_len) {
2222         put_packet("E00");
2223         return;
2224     }
2225
2226     if (len > (MAX_PACKET_LENGTH - 5) / 2) {
2227         len = (MAX_PACKET_LENGTH - 5) / 2;
2228     }
2229
2230     if (len < total_len - addr) {
2231         g_string_assign(gdbserver_state.str_buf, "m");
2232         memtox(gdbserver_state.str_buf, xml + addr, len);
2233     } else {
2234         g_string_assign(gdbserver_state.str_buf, "l");
2235         memtox(gdbserver_state.str_buf, xml + addr, total_len - addr);
2236     }
2237
2238     put_packet_binary(gdbserver_state.str_buf->str,
2239                       gdbserver_state.str_buf->len, true);
2240 }
2241
2242 #if defined(CONFIG_USER_ONLY) && defined(CONFIG_LINUX_USER)
2243 static void handle_query_xfer_auxv(GdbCmdContext *gdb_ctx, void *user_ctx)
2244 {
2245     TaskState *ts;
2246     unsigned long offset, len, saved_auxv, auxv_len;
2247     const char *mem;
2248
2249     if (gdb_ctx->num_params < 2) {
2250         put_packet("E22");
2251         return;
2252     }
2253
2254     offset = gdb_ctx->params[0].val_ul;
2255     len = gdb_ctx->params[1].val_ul;
2256     ts = gdbserver_state.c_cpu->opaque;
2257     saved_auxv = ts->info->saved_auxv;
2258     auxv_len = ts->info->auxv_len;
2259     mem = (const char *)(saved_auxv + offset);
2260     if (offset > auxv_len) {
2261         put_packet("E00");
2262         return;
2263     }
2264
2265     if (len > (MAX_PACKET_LENGTH - 5) / 2) {
2266         len = (MAX_PACKET_LENGTH - 5) / 2;
2267     }
2268
2269     if (len < auxv_len - offset) {
2270         g_string_assign(gdbserver_state.str_buf, "m");
2271         memtox(gdbserver_state.str_buf, mem, len);
2272     } else {
2273         g_string_assign(gdbserver_state.str_buf, "l");
2274         memtox(gdbserver_state.str_buf, mem, auxv_len - offset);
2275     }
2276
2277     put_packet_binary(gdbserver_state.str_buf->str,
2278                       gdbserver_state.str_buf->len, true);
2279 }
2280 #endif
2281
2282 static void handle_query_attached(GdbCmdContext *gdb_ctx, void *user_ctx)
2283 {
2284     put_packet(GDB_ATTACHED);
2285 }
2286
2287 static void handle_query_qemu_supported(GdbCmdContext *gdb_ctx, void *user_ctx)
2288 {
2289     g_string_printf(gdbserver_state.str_buf, "sstepbits;sstep");
2290 #ifndef CONFIG_USER_ONLY
2291     g_string_append(gdbserver_state.str_buf, ";PhyMemMode");
2292 #endif
2293     put_strbuf();
2294 }
2295
2296 #ifndef CONFIG_USER_ONLY
2297 static void handle_query_qemu_phy_mem_mode(GdbCmdContext *gdb_ctx,
2298                                            void *user_ctx)
2299 {
2300     g_string_printf(gdbserver_state.str_buf, "%d", phy_memory_mode);
2301     put_strbuf();
2302 }
2303
2304 static void handle_set_qemu_phy_mem_mode(GdbCmdContext *gdb_ctx, void *user_ctx)
2305 {
2306     if (!gdb_ctx->num_params) {
2307         put_packet("E22");
2308         return;
2309     }
2310
2311     if (!gdb_ctx->params[0].val_ul) {
2312         phy_memory_mode = 0;
2313     } else {
2314         phy_memory_mode = 1;
2315     }
2316     put_packet("OK");
2317 }
2318 #endif
2319
2320 static GdbCmdParseEntry gdb_gen_query_set_common_table[] = {
2321     /* Order is important if has same prefix */
2322     {
2323         .handler = handle_query_qemu_sstepbits,
2324         .cmd = "qemu.sstepbits",
2325     },
2326     {
2327         .handler = handle_query_qemu_sstep,
2328         .cmd = "qemu.sstep",
2329     },
2330     {
2331         .handler = handle_set_qemu_sstep,
2332         .cmd = "qemu.sstep=",
2333         .cmd_startswith = 1,
2334         .schema = "l0"
2335     },
2336 };
2337
2338 static GdbCmdParseEntry gdb_gen_query_table[] = {
2339     {
2340         .handler = handle_query_curr_tid,
2341         .cmd = "C",
2342     },
2343     {
2344         .handler = handle_query_threads,
2345         .cmd = "sThreadInfo",
2346     },
2347     {
2348         .handler = handle_query_first_threads,
2349         .cmd = "fThreadInfo",
2350     },
2351     {
2352         .handler = handle_query_thread_extra,
2353         .cmd = "ThreadExtraInfo,",
2354         .cmd_startswith = 1,
2355         .schema = "t0"
2356     },
2357 #ifdef CONFIG_USER_ONLY
2358     {
2359         .handler = handle_query_offsets,
2360         .cmd = "Offsets",
2361     },
2362 #else
2363     {
2364         .handler = handle_query_rcmd,
2365         .cmd = "Rcmd,",
2366         .cmd_startswith = 1,
2367         .schema = "s0"
2368     },
2369 #endif
2370     {
2371         .handler = handle_query_supported,
2372         .cmd = "Supported:",
2373         .cmd_startswith = 1,
2374         .schema = "s0"
2375     },
2376     {
2377         .handler = handle_query_supported,
2378         .cmd = "Supported",
2379         .schema = "s0"
2380     },
2381     {
2382         .handler = handle_query_xfer_features,
2383         .cmd = "Xfer:features:read:",
2384         .cmd_startswith = 1,
2385         .schema = "s:l,l0"
2386     },
2387 #if defined(CONFIG_USER_ONLY) && defined(CONFIG_LINUX_USER)
2388     {
2389         .handler = handle_query_xfer_auxv,
2390         .cmd = "Xfer:auxv:read::",
2391         .cmd_startswith = 1,
2392         .schema = "l,l0"
2393     },
2394 #endif
2395     {
2396         .handler = handle_query_attached,
2397         .cmd = "Attached:",
2398         .cmd_startswith = 1
2399     },
2400     {
2401         .handler = handle_query_attached,
2402         .cmd = "Attached",
2403     },
2404     {
2405         .handler = handle_query_qemu_supported,
2406         .cmd = "qemu.Supported",
2407     },
2408 #ifndef CONFIG_USER_ONLY
2409     {
2410         .handler = handle_query_qemu_phy_mem_mode,
2411         .cmd = "qemu.PhyMemMode",
2412     },
2413 #endif
2414 };
2415
2416 static GdbCmdParseEntry gdb_gen_set_table[] = {
2417     /* Order is important if has same prefix */
2418     {
2419         .handler = handle_set_qemu_sstep,
2420         .cmd = "qemu.sstep:",
2421         .cmd_startswith = 1,
2422         .schema = "l0"
2423     },
2424 #ifndef CONFIG_USER_ONLY
2425     {
2426         .handler = handle_set_qemu_phy_mem_mode,
2427         .cmd = "qemu.PhyMemMode:",
2428         .cmd_startswith = 1,
2429         .schema = "l0"
2430     },
2431 #endif
2432 };
2433
2434 static void handle_gen_query(GdbCmdContext *gdb_ctx, void *user_ctx)
2435 {
2436     if (!gdb_ctx->num_params) {
2437         return;
2438     }
2439
2440     if (!process_string_cmd(NULL, gdb_ctx->params[0].data,
2441                             gdb_gen_query_set_common_table,
2442                             ARRAY_SIZE(gdb_gen_query_set_common_table))) {
2443         return;
2444     }
2445
2446     if (process_string_cmd(NULL, gdb_ctx->params[0].data,
2447                            gdb_gen_query_table,
2448                            ARRAY_SIZE(gdb_gen_query_table))) {
2449         put_packet("");
2450     }
2451 }
2452
2453 static void handle_gen_set(GdbCmdContext *gdb_ctx, void *user_ctx)
2454 {
2455     if (!gdb_ctx->num_params) {
2456         return;
2457     }
2458
2459     if (!process_string_cmd(NULL, gdb_ctx->params[0].data,
2460                             gdb_gen_query_set_common_table,
2461                             ARRAY_SIZE(gdb_gen_query_set_common_table))) {
2462         return;
2463     }
2464
2465     if (process_string_cmd(NULL, gdb_ctx->params[0].data,
2466                            gdb_gen_set_table,
2467                            ARRAY_SIZE(gdb_gen_set_table))) {
2468         put_packet("");
2469     }
2470 }
2471
2472 static void handle_target_halt(GdbCmdContext *gdb_ctx, void *user_ctx)
2473 {
2474     g_string_printf(gdbserver_state.str_buf, "T%02xthread:", GDB_SIGNAL_TRAP);
2475     gdb_append_thread_id(gdbserver_state.c_cpu, gdbserver_state.str_buf);
2476     g_string_append_c(gdbserver_state.str_buf, ';');
2477     put_strbuf();
2478     /*
2479      * Remove all the breakpoints when this query is issued,
2480      * because gdb is doing an initial connect and the state
2481      * should be cleaned up.
2482      */
2483     gdb_breakpoint_remove_all();
2484 }
2485
2486 static int gdb_handle_packet(const char *line_buf)
2487 {
2488     const GdbCmdParseEntry *cmd_parser = NULL;
2489
2490     trace_gdbstub_io_command(line_buf);
2491
2492     switch (line_buf[0]) {
2493     case '!':
2494         put_packet("OK");
2495         break;
2496     case '?':
2497         {
2498             static const GdbCmdParseEntry target_halted_cmd_desc = {
2499                 .handler = handle_target_halt,
2500                 .cmd = "?",
2501                 .cmd_startswith = 1
2502             };
2503             cmd_parser = &target_halted_cmd_desc;
2504         }
2505         break;
2506     case 'c':
2507         {
2508             static const GdbCmdParseEntry continue_cmd_desc = {
2509                 .handler = handle_continue,
2510                 .cmd = "c",
2511                 .cmd_startswith = 1,
2512                 .schema = "L0"
2513             };
2514             cmd_parser = &continue_cmd_desc;
2515         }
2516         break;
2517     case 'C':
2518         {
2519             static const GdbCmdParseEntry cont_with_sig_cmd_desc = {
2520                 .handler = handle_cont_with_sig,
2521                 .cmd = "C",
2522                 .cmd_startswith = 1,
2523                 .schema = "l0"
2524             };
2525             cmd_parser = &cont_with_sig_cmd_desc;
2526         }
2527         break;
2528     case 'v':
2529         {
2530             static const GdbCmdParseEntry v_cmd_desc = {
2531                 .handler = handle_v_commands,
2532                 .cmd = "v",
2533                 .cmd_startswith = 1,
2534                 .schema = "s0"
2535             };
2536             cmd_parser = &v_cmd_desc;
2537         }
2538         break;
2539     case 'k':
2540         /* Kill the target */
2541         error_report("QEMU: Terminated via GDBstub");
2542         exit(0);
2543     case 'D':
2544         {
2545             static const GdbCmdParseEntry detach_cmd_desc = {
2546                 .handler = handle_detach,
2547                 .cmd = "D",
2548                 .cmd_startswith = 1,
2549                 .schema = "?.l0"
2550             };
2551             cmd_parser = &detach_cmd_desc;
2552         }
2553         break;
2554     case 's':
2555         {
2556             static const GdbCmdParseEntry step_cmd_desc = {
2557                 .handler = handle_step,
2558                 .cmd = "s",
2559                 .cmd_startswith = 1,
2560                 .schema = "L0"
2561             };
2562             cmd_parser = &step_cmd_desc;
2563         }
2564         break;
2565     case 'b':
2566         {
2567             static const GdbCmdParseEntry backward_cmd_desc = {
2568                 .handler = handle_backward,
2569                 .cmd = "b",
2570                 .cmd_startswith = 1,
2571                 .schema = "o0"
2572             };
2573             cmd_parser = &backward_cmd_desc;
2574         }
2575         break;
2576     case 'F':
2577         {
2578             static const GdbCmdParseEntry file_io_cmd_desc = {
2579                 .handler = handle_file_io,
2580                 .cmd = "F",
2581                 .cmd_startswith = 1,
2582                 .schema = "L,L,o0"
2583             };
2584             cmd_parser = &file_io_cmd_desc;
2585         }
2586         break;
2587     case 'g':
2588         {
2589             static const GdbCmdParseEntry read_all_regs_cmd_desc = {
2590                 .handler = handle_read_all_regs,
2591                 .cmd = "g",
2592                 .cmd_startswith = 1
2593             };
2594             cmd_parser = &read_all_regs_cmd_desc;
2595         }
2596         break;
2597     case 'G':
2598         {
2599             static const GdbCmdParseEntry write_all_regs_cmd_desc = {
2600                 .handler = handle_write_all_regs,
2601                 .cmd = "G",
2602                 .cmd_startswith = 1,
2603                 .schema = "s0"
2604             };
2605             cmd_parser = &write_all_regs_cmd_desc;
2606         }
2607         break;
2608     case 'm':
2609         {
2610             static const GdbCmdParseEntry read_mem_cmd_desc = {
2611                 .handler = handle_read_mem,
2612                 .cmd = "m",
2613                 .cmd_startswith = 1,
2614                 .schema = "L,L0"
2615             };
2616             cmd_parser = &read_mem_cmd_desc;
2617         }
2618         break;
2619     case 'M':
2620         {
2621             static const GdbCmdParseEntry write_mem_cmd_desc = {
2622                 .handler = handle_write_mem,
2623                 .cmd = "M",
2624                 .cmd_startswith = 1,
2625                 .schema = "L,L:s0"
2626             };
2627             cmd_parser = &write_mem_cmd_desc;
2628         }
2629         break;
2630     case 'p':
2631         {
2632             static const GdbCmdParseEntry get_reg_cmd_desc = {
2633                 .handler = handle_get_reg,
2634                 .cmd = "p",
2635                 .cmd_startswith = 1,
2636                 .schema = "L0"
2637             };
2638             cmd_parser = &get_reg_cmd_desc;
2639         }
2640         break;
2641     case 'P':
2642         {
2643             static const GdbCmdParseEntry set_reg_cmd_desc = {
2644                 .handler = handle_set_reg,
2645                 .cmd = "P",
2646                 .cmd_startswith = 1,
2647                 .schema = "L?s0"
2648             };
2649             cmd_parser = &set_reg_cmd_desc;
2650         }
2651         break;
2652     case 'Z':
2653         {
2654             static const GdbCmdParseEntry insert_bp_cmd_desc = {
2655                 .handler = handle_insert_bp,
2656                 .cmd = "Z",
2657                 .cmd_startswith = 1,
2658                 .schema = "l?L?L0"
2659             };
2660             cmd_parser = &insert_bp_cmd_desc;
2661         }
2662         break;
2663     case 'z':
2664         {
2665             static const GdbCmdParseEntry remove_bp_cmd_desc = {
2666                 .handler = handle_remove_bp,
2667                 .cmd = "z",
2668                 .cmd_startswith = 1,
2669                 .schema = "l?L?L0"
2670             };
2671             cmd_parser = &remove_bp_cmd_desc;
2672         }
2673         break;
2674     case 'H':
2675         {
2676             static const GdbCmdParseEntry set_thread_cmd_desc = {
2677                 .handler = handle_set_thread,
2678                 .cmd = "H",
2679                 .cmd_startswith = 1,
2680                 .schema = "o.t0"
2681             };
2682             cmd_parser = &set_thread_cmd_desc;
2683         }
2684         break;
2685     case 'T':
2686         {
2687             static const GdbCmdParseEntry thread_alive_cmd_desc = {
2688                 .handler = handle_thread_alive,
2689                 .cmd = "T",
2690                 .cmd_startswith = 1,
2691                 .schema = "t0"
2692             };
2693             cmd_parser = &thread_alive_cmd_desc;
2694         }
2695         break;
2696     case 'q':
2697         {
2698             static const GdbCmdParseEntry gen_query_cmd_desc = {
2699                 .handler = handle_gen_query,
2700                 .cmd = "q",
2701                 .cmd_startswith = 1,
2702                 .schema = "s0"
2703             };
2704             cmd_parser = &gen_query_cmd_desc;
2705         }
2706         break;
2707     case 'Q':
2708         {
2709             static const GdbCmdParseEntry gen_set_cmd_desc = {
2710                 .handler = handle_gen_set,
2711                 .cmd = "Q",
2712                 .cmd_startswith = 1,
2713                 .schema = "s0"
2714             };
2715             cmd_parser = &gen_set_cmd_desc;
2716         }
2717         break;
2718     default:
2719         /* put empty packet */
2720         put_packet("");
2721         break;
2722     }
2723
2724     if (cmd_parser) {
2725         run_cmd_parser(line_buf, cmd_parser);
2726     }
2727
2728     return RS_IDLE;
2729 }
2730
2731 void gdb_set_stop_cpu(CPUState *cpu)
2732 {
2733     GDBProcess *p = gdb_get_cpu_process(cpu);
2734
2735     if (!p->attached) {
2736         /*
2737          * Having a stop CPU corresponding to a process that is not attached
2738          * confuses GDB. So we ignore the request.
2739          */
2740         return;
2741     }
2742
2743     gdbserver_state.c_cpu = cpu;
2744     gdbserver_state.g_cpu = cpu;
2745 }
2746
2747 #ifndef CONFIG_USER_ONLY
2748 static void gdb_vm_state_change(void *opaque, int running, RunState state)
2749 {
2750     CPUState *cpu = gdbserver_state.c_cpu;
2751     g_autoptr(GString) buf = g_string_new(NULL);
2752     g_autoptr(GString) tid = g_string_new(NULL);
2753     const char *type;
2754     int ret;
2755
2756     if (running || gdbserver_state.state == RS_INACTIVE) {
2757         return;
2758     }
2759     /* Is there a GDB syscall waiting to be sent?  */
2760     if (gdbserver_state.current_syscall_cb) {
2761         put_packet(gdbserver_state.syscall_buf);
2762         return;
2763     }
2764
2765     if (cpu == NULL) {
2766         /* No process attached */
2767         return;
2768     }
2769
2770     gdb_append_thread_id(cpu, tid);
2771
2772     switch (state) {
2773     case RUN_STATE_DEBUG:
2774         if (cpu->watchpoint_hit) {
2775             switch (cpu->watchpoint_hit->flags & BP_MEM_ACCESS) {
2776             case BP_MEM_READ:
2777                 type = "r";
2778                 break;
2779             case BP_MEM_ACCESS:
2780                 type = "a";
2781                 break;
2782             default:
2783                 type = "";
2784                 break;
2785             }
2786             trace_gdbstub_hit_watchpoint(type, cpu_gdb_index(cpu),
2787                     (target_ulong)cpu->watchpoint_hit->vaddr);
2788             g_string_printf(buf, "T%02xthread:%s;%swatch:" TARGET_FMT_lx ";",
2789                             GDB_SIGNAL_TRAP, tid->str, type,
2790                             (target_ulong)cpu->watchpoint_hit->vaddr);
2791             cpu->watchpoint_hit = NULL;
2792             goto send_packet;
2793         } else {
2794             trace_gdbstub_hit_break();
2795         }
2796         tb_flush(cpu);
2797         ret = GDB_SIGNAL_TRAP;
2798         break;
2799     case RUN_STATE_PAUSED:
2800         trace_gdbstub_hit_paused();
2801         ret = GDB_SIGNAL_INT;
2802         break;
2803     case RUN_STATE_SHUTDOWN:
2804         trace_gdbstub_hit_shutdown();
2805         ret = GDB_SIGNAL_QUIT;
2806         break;
2807     case RUN_STATE_IO_ERROR:
2808         trace_gdbstub_hit_io_error();
2809         ret = GDB_SIGNAL_IO;
2810         break;
2811     case RUN_STATE_WATCHDOG:
2812         trace_gdbstub_hit_watchdog();
2813         ret = GDB_SIGNAL_ALRM;
2814         break;
2815     case RUN_STATE_INTERNAL_ERROR:
2816         trace_gdbstub_hit_internal_error();
2817         ret = GDB_SIGNAL_ABRT;
2818         break;
2819     case RUN_STATE_SAVE_VM:
2820     case RUN_STATE_RESTORE_VM:
2821         return;
2822     case RUN_STATE_FINISH_MIGRATE:
2823         ret = GDB_SIGNAL_XCPU;
2824         break;
2825     default:
2826         trace_gdbstub_hit_unknown(state);
2827         ret = GDB_SIGNAL_UNKNOWN;
2828         break;
2829     }
2830     gdb_set_stop_cpu(cpu);
2831     g_string_printf(buf, "T%02xthread:%s;", ret, tid->str);
2832
2833 send_packet:
2834     put_packet(buf->str);
2835
2836     /* disable single step if it was enabled */
2837     cpu_single_step(cpu, 0);
2838 }
2839 #endif
2840
2841 /* Send a gdb syscall request.
2842    This accepts limited printf-style format specifiers, specifically:
2843     %x  - target_ulong argument printed in hex.
2844     %lx - 64-bit argument printed in hex.
2845     %s  - string pointer (target_ulong) and length (int) pair.  */
2846 void gdb_do_syscallv(gdb_syscall_complete_cb cb, const char *fmt, va_list va)
2847 {
2848     char *p;
2849     char *p_end;
2850     target_ulong addr;
2851     uint64_t i64;
2852
2853     if (!gdbserver_state.init) {
2854         return;
2855     }
2856
2857     gdbserver_state.current_syscall_cb = cb;
2858 #ifndef CONFIG_USER_ONLY
2859     vm_stop(RUN_STATE_DEBUG);
2860 #endif
2861     p = &gdbserver_state.syscall_buf[0];
2862     p_end = &gdbserver_state.syscall_buf[sizeof(gdbserver_state.syscall_buf)];
2863     *(p++) = 'F';
2864     while (*fmt) {
2865         if (*fmt == '%') {
2866             fmt++;
2867             switch (*fmt++) {
2868             case 'x':
2869                 addr = va_arg(va, target_ulong);
2870                 p += snprintf(p, p_end - p, TARGET_FMT_lx, addr);
2871                 break;
2872             case 'l':
2873                 if (*(fmt++) != 'x')
2874                     goto bad_format;
2875                 i64 = va_arg(va, uint64_t);
2876                 p += snprintf(p, p_end - p, "%" PRIx64, i64);
2877                 break;
2878             case 's':
2879                 addr = va_arg(va, target_ulong);
2880                 p += snprintf(p, p_end - p, TARGET_FMT_lx "/%x",
2881                               addr, va_arg(va, int));
2882                 break;
2883             default:
2884             bad_format:
2885                 error_report("gdbstub: Bad syscall format string '%s'",
2886                              fmt - 1);
2887                 break;
2888             }
2889         } else {
2890             *(p++) = *(fmt++);
2891         }
2892     }
2893     *p = 0;
2894 #ifdef CONFIG_USER_ONLY
2895     put_packet(gdbserver_state.syscall_buf);
2896     /* Return control to gdb for it to process the syscall request.
2897      * Since the protocol requires that gdb hands control back to us
2898      * using a "here are the results" F packet, we don't need to check
2899      * gdb_handlesig's return value (which is the signal to deliver if
2900      * execution was resumed via a continue packet).
2901      */
2902     gdb_handlesig(gdbserver_state.c_cpu, 0);
2903 #else
2904     /* In this case wait to send the syscall packet until notification that
2905        the CPU has stopped.  This must be done because if the packet is sent
2906        now the reply from the syscall request could be received while the CPU
2907        is still in the running state, which can cause packets to be dropped
2908        and state transition 'T' packets to be sent while the syscall is still
2909        being processed.  */
2910     qemu_cpu_kick(gdbserver_state.c_cpu);
2911 #endif
2912 }
2913
2914 void gdb_do_syscall(gdb_syscall_complete_cb cb, const char *fmt, ...)
2915 {
2916     va_list va;
2917
2918     va_start(va, fmt);
2919     gdb_do_syscallv(cb, fmt, va);
2920     va_end(va);
2921 }
2922
2923 static void gdb_read_byte(uint8_t ch)
2924 {
2925     uint8_t reply;
2926
2927 #ifndef CONFIG_USER_ONLY
2928     if (gdbserver_state.last_packet->len) {
2929         /* Waiting for a response to the last packet.  If we see the start
2930            of a new command then abandon the previous response.  */
2931         if (ch == '-') {
2932             trace_gdbstub_err_got_nack();
2933             put_buffer(gdbserver_state.last_packet->data,
2934                        gdbserver_state.last_packet->len);
2935         } else if (ch == '+') {
2936             trace_gdbstub_io_got_ack();
2937         } else {
2938             trace_gdbstub_io_got_unexpected(ch);
2939         }
2940
2941         if (ch == '+' || ch == '$') {
2942             g_byte_array_set_size(gdbserver_state.last_packet, 0);
2943         }
2944         if (ch != '$')
2945             return;
2946     }
2947     if (runstate_is_running()) {
2948         /* when the CPU is running, we cannot do anything except stop
2949            it when receiving a char */
2950         vm_stop(RUN_STATE_PAUSED);
2951     } else
2952 #endif
2953     {
2954         switch(gdbserver_state.state) {
2955         case RS_IDLE:
2956             if (ch == '$') {
2957                 /* start of command packet */
2958                 gdbserver_state.line_buf_index = 0;
2959                 gdbserver_state.line_sum = 0;
2960                 gdbserver_state.state = RS_GETLINE;
2961             } else {
2962                 trace_gdbstub_err_garbage(ch);
2963             }
2964             break;
2965         case RS_GETLINE:
2966             if (ch == '}') {
2967                 /* start escape sequence */
2968                 gdbserver_state.state = RS_GETLINE_ESC;
2969                 gdbserver_state.line_sum += ch;
2970             } else if (ch == '*') {
2971                 /* start run length encoding sequence */
2972                 gdbserver_state.state = RS_GETLINE_RLE;
2973                 gdbserver_state.line_sum += ch;
2974             } else if (ch == '#') {
2975                 /* end of command, start of checksum*/
2976                 gdbserver_state.state = RS_CHKSUM1;
2977             } else if (gdbserver_state.line_buf_index >= sizeof(gdbserver_state.line_buf) - 1) {
2978                 trace_gdbstub_err_overrun();
2979                 gdbserver_state.state = RS_IDLE;
2980             } else {
2981                 /* unescaped command character */
2982                 gdbserver_state.line_buf[gdbserver_state.line_buf_index++] = ch;
2983                 gdbserver_state.line_sum += ch;
2984             }
2985             break;
2986         case RS_GETLINE_ESC:
2987             if (ch == '#') {
2988                 /* unexpected end of command in escape sequence */
2989                 gdbserver_state.state = RS_CHKSUM1;
2990             } else if (gdbserver_state.line_buf_index >= sizeof(gdbserver_state.line_buf) - 1) {
2991                 /* command buffer overrun */
2992                 trace_gdbstub_err_overrun();
2993                 gdbserver_state.state = RS_IDLE;
2994             } else {
2995                 /* parse escaped character and leave escape state */
2996                 gdbserver_state.line_buf[gdbserver_state.line_buf_index++] = ch ^ 0x20;
2997                 gdbserver_state.line_sum += ch;
2998                 gdbserver_state.state = RS_GETLINE;
2999             }
3000             break;
3001         case RS_GETLINE_RLE:
3002             /*
3003              * Run-length encoding is explained in "Debugging with GDB /
3004              * Appendix E GDB Remote Serial Protocol / Overview".
3005              */
3006             if (ch < ' ' || ch == '#' || ch == '$' || ch > 126) {
3007                 /* invalid RLE count encoding */
3008                 trace_gdbstub_err_invalid_repeat(ch);
3009                 gdbserver_state.state = RS_GETLINE;
3010             } else {
3011                 /* decode repeat length */
3012                 int repeat = ch - ' ' + 3;
3013                 if (gdbserver_state.line_buf_index + repeat >= sizeof(gdbserver_state.line_buf) - 1) {
3014                     /* that many repeats would overrun the command buffer */
3015                     trace_gdbstub_err_overrun();
3016                     gdbserver_state.state = RS_IDLE;
3017                 } else if (gdbserver_state.line_buf_index < 1) {
3018                     /* got a repeat but we have nothing to repeat */
3019                     trace_gdbstub_err_invalid_rle();
3020                     gdbserver_state.state = RS_GETLINE;
3021                 } else {
3022                     /* repeat the last character */
3023                     memset(gdbserver_state.line_buf + gdbserver_state.line_buf_index,
3024                            gdbserver_state.line_buf[gdbserver_state.line_buf_index - 1], repeat);
3025                     gdbserver_state.line_buf_index += repeat;
3026                     gdbserver_state.line_sum += ch;
3027                     gdbserver_state.state = RS_GETLINE;
3028                 }
3029             }
3030             break;
3031         case RS_CHKSUM1:
3032             /* get high hex digit of checksum */
3033             if (!isxdigit(ch)) {
3034                 trace_gdbstub_err_checksum_invalid(ch);
3035                 gdbserver_state.state = RS_GETLINE;
3036                 break;
3037             }
3038             gdbserver_state.line_buf[gdbserver_state.line_buf_index] = '\0';
3039             gdbserver_state.line_csum = fromhex(ch) << 4;
3040             gdbserver_state.state = RS_CHKSUM2;
3041             break;
3042         case RS_CHKSUM2:
3043             /* get low hex digit of checksum */
3044             if (!isxdigit(ch)) {
3045                 trace_gdbstub_err_checksum_invalid(ch);
3046                 gdbserver_state.state = RS_GETLINE;
3047                 break;
3048             }
3049             gdbserver_state.line_csum |= fromhex(ch);
3050
3051             if (gdbserver_state.line_csum != (gdbserver_state.line_sum & 0xff)) {
3052                 trace_gdbstub_err_checksum_incorrect(gdbserver_state.line_sum, gdbserver_state.line_csum);
3053                 /* send NAK reply */
3054                 reply = '-';
3055                 put_buffer(&reply, 1);
3056                 gdbserver_state.state = RS_IDLE;
3057             } else {
3058                 /* send ACK reply */
3059                 reply = '+';
3060                 put_buffer(&reply, 1);
3061                 gdbserver_state.state = gdb_handle_packet(gdbserver_state.line_buf);
3062             }
3063             break;
3064         default:
3065             abort();
3066         }
3067     }
3068 }
3069
3070 /* Tell the remote gdb that the process has exited.  */
3071 void gdb_exit(CPUArchState *env, int code)
3072 {
3073   char buf[4];
3074
3075   if (!gdbserver_state.init) {
3076       return;
3077   }
3078 #ifdef CONFIG_USER_ONLY
3079   if (gdbserver_state.socket_path) {
3080       unlink(gdbserver_state.socket_path);
3081   }
3082   if (gdbserver_state.fd < 0) {
3083       return;
3084   }
3085 #endif
3086
3087   trace_gdbstub_op_exiting((uint8_t)code);
3088
3089   snprintf(buf, sizeof(buf), "W%02x", (uint8_t)code);
3090   put_packet(buf);
3091
3092 #ifndef CONFIG_USER_ONLY
3093   qemu_chr_fe_deinit(&gdbserver_state.chr, true);
3094 #endif
3095 }
3096
3097 /*
3098  * Create the process that will contain all the "orphan" CPUs (that are not
3099  * part of a CPU cluster). Note that if this process contains no CPUs, it won't
3100  * be attachable and thus will be invisible to the user.
3101  */
3102 static void create_default_process(GDBState *s)
3103 {
3104     GDBProcess *process;
3105     int max_pid = 0;
3106
3107     if (gdbserver_state.process_num) {
3108         max_pid = s->processes[s->process_num - 1].pid;
3109     }
3110
3111     s->processes = g_renew(GDBProcess, s->processes, ++s->process_num);
3112     process = &s->processes[s->process_num - 1];
3113
3114     /* We need an available PID slot for this process */
3115     assert(max_pid < UINT32_MAX);
3116
3117     process->pid = max_pid + 1;
3118     process->attached = false;
3119     process->target_xml[0] = '\0';
3120 }
3121
3122 #ifdef CONFIG_USER_ONLY
3123 int
3124 gdb_handlesig(CPUState *cpu, int sig)
3125 {
3126     char buf[256];
3127     int n;
3128
3129     if (!gdbserver_state.init || gdbserver_state.fd < 0) {
3130         return sig;
3131     }
3132
3133     /* disable single step if it was enabled */
3134     cpu_single_step(cpu, 0);
3135     tb_flush(cpu);
3136
3137     if (sig != 0) {
3138         snprintf(buf, sizeof(buf), "S%02x", target_signal_to_gdb(sig));
3139         put_packet(buf);
3140     }
3141     /* put_packet() might have detected that the peer terminated the
3142        connection.  */
3143     if (gdbserver_state.fd < 0) {
3144         return sig;
3145     }
3146
3147     sig = 0;
3148     gdbserver_state.state = RS_IDLE;
3149     gdbserver_state.running_state = 0;
3150     while (gdbserver_state.running_state == 0) {
3151         n = read(gdbserver_state.fd, buf, 256);
3152         if (n > 0) {
3153             int i;
3154
3155             for (i = 0; i < n; i++) {
3156                 gdb_read_byte(buf[i]);
3157             }
3158         } else {
3159             /* XXX: Connection closed.  Should probably wait for another
3160                connection before continuing.  */
3161             if (n == 0) {
3162                 close(gdbserver_state.fd);
3163             }
3164             gdbserver_state.fd = -1;
3165             return sig;
3166         }
3167     }
3168     sig = gdbserver_state.signal;
3169     gdbserver_state.signal = 0;
3170     return sig;
3171 }
3172
3173 /* Tell the remote gdb that the process has exited due to SIG.  */
3174 void gdb_signalled(CPUArchState *env, int sig)
3175 {
3176     char buf[4];
3177
3178     if (!gdbserver_state.init || gdbserver_state.fd < 0) {
3179         return;
3180     }
3181
3182     snprintf(buf, sizeof(buf), "X%02x", target_signal_to_gdb(sig));
3183     put_packet(buf);
3184 }
3185
3186 static void gdb_accept_init(int fd)
3187 {
3188     init_gdbserver_state();
3189     create_default_process(&gdbserver_state);
3190     gdbserver_state.processes[0].attached = true;
3191     gdbserver_state.c_cpu = gdb_first_attached_cpu();
3192     gdbserver_state.g_cpu = gdbserver_state.c_cpu;
3193     gdbserver_state.fd = fd;
3194     gdb_has_xml = false;
3195 }
3196
3197 static bool gdb_accept_socket(int gdb_fd)
3198 {
3199     int fd;
3200
3201     for(;;) {
3202         fd = accept(gdb_fd, NULL, NULL);
3203         if (fd < 0 && errno != EINTR) {
3204             perror("accept socket");
3205             return false;
3206         } else if (fd >= 0) {
3207             qemu_set_cloexec(fd);
3208             break;
3209         }
3210     }
3211
3212     gdb_accept_init(fd);
3213     return true;
3214 }
3215
3216 static int gdbserver_open_socket(const char *path)
3217 {
3218     struct sockaddr_un sockaddr;
3219     int fd, ret;
3220
3221     fd = socket(AF_UNIX, SOCK_STREAM, 0);
3222     if (fd < 0) {
3223         perror("create socket");
3224         return -1;
3225     }
3226
3227     sockaddr.sun_family = AF_UNIX;
3228     pstrcpy(sockaddr.sun_path, sizeof(sockaddr.sun_path) - 1, path);
3229     ret = bind(fd, (struct sockaddr *)&sockaddr, sizeof(sockaddr));
3230     if (ret < 0) {
3231         perror("bind socket");
3232         close(fd);
3233         return -1;
3234     }
3235     ret = listen(fd, 1);
3236     if (ret < 0) {
3237         perror("listen socket");
3238         close(fd);
3239         return -1;
3240     }
3241
3242     return fd;
3243 }
3244
3245 static bool gdb_accept_tcp(int gdb_fd)
3246 {
3247     struct sockaddr_in sockaddr;
3248     socklen_t len;
3249     int fd;
3250
3251     for(;;) {
3252         len = sizeof(sockaddr);
3253         fd = accept(gdb_fd, (struct sockaddr *)&sockaddr, &len);
3254         if (fd < 0 && errno != EINTR) {
3255             perror("accept");
3256             return false;
3257         } else if (fd >= 0) {
3258             qemu_set_cloexec(fd);
3259             break;
3260         }
3261     }
3262
3263     /* set short latency */
3264     if (socket_set_nodelay(fd)) {
3265         perror("setsockopt");
3266         close(fd);
3267         return false;
3268     }
3269
3270     gdb_accept_init(fd);
3271     return true;
3272 }
3273
3274 static int gdbserver_open_port(int port)
3275 {
3276     struct sockaddr_in sockaddr;
3277     int fd, ret;
3278
3279     fd = socket(PF_INET, SOCK_STREAM, 0);
3280     if (fd < 0) {
3281         perror("socket");
3282         return -1;
3283     }
3284     qemu_set_cloexec(fd);
3285
3286     socket_set_fast_reuse(fd);
3287
3288     sockaddr.sin_family = AF_INET;
3289     sockaddr.sin_port = htons(port);
3290     sockaddr.sin_addr.s_addr = 0;
3291     ret = bind(fd, (struct sockaddr *)&sockaddr, sizeof(sockaddr));
3292     if (ret < 0) {
3293         perror("bind");
3294         close(fd);
3295         return -1;
3296     }
3297     ret = listen(fd, 1);
3298     if (ret < 0) {
3299         perror("listen");
3300         close(fd);
3301         return -1;
3302     }
3303
3304     return fd;
3305 }
3306
3307 int gdbserver_start(const char *port_or_path)
3308 {
3309     int port = g_ascii_strtoull(port_or_path, NULL, 10);
3310     int gdb_fd;
3311
3312     if (port > 0) {
3313         gdb_fd = gdbserver_open_port(port);
3314     } else {
3315         gdb_fd = gdbserver_open_socket(port_or_path);
3316     }
3317
3318     if (gdb_fd < 0) {
3319         return -1;
3320     }
3321
3322     if (port > 0 && gdb_accept_tcp(gdb_fd)) {
3323         return 0;
3324     } else if (gdb_accept_socket(gdb_fd)) {
3325         gdbserver_state.socket_path = g_strdup(port_or_path);
3326         return 0;
3327     }
3328
3329     /* gone wrong */
3330     close(gdb_fd);
3331     return -1;
3332 }
3333
3334 /* Disable gdb stub for child processes.  */
3335 void gdbserver_fork(CPUState *cpu)
3336 {
3337     if (!gdbserver_state.init || gdbserver_state.fd < 0) {
3338         return;
3339     }
3340     close(gdbserver_state.fd);
3341     gdbserver_state.fd = -1;
3342     cpu_breakpoint_remove_all(cpu, BP_GDB);
3343     cpu_watchpoint_remove_all(cpu, BP_GDB);
3344 }
3345 #else
3346 static int gdb_chr_can_receive(void *opaque)
3347 {
3348   /* We can handle an arbitrarily large amount of data.
3349    Pick the maximum packet size, which is as good as anything.  */
3350   return MAX_PACKET_LENGTH;
3351 }
3352
3353 static void gdb_chr_receive(void *opaque, const uint8_t *buf, int size)
3354 {
3355     int i;
3356
3357     for (i = 0; i < size; i++) {
3358         gdb_read_byte(buf[i]);
3359     }
3360 }
3361
3362 static void gdb_chr_event(void *opaque, QEMUChrEvent event)
3363 {
3364     int i;
3365     GDBState *s = (GDBState *) opaque;
3366
3367     switch (event) {
3368     case CHR_EVENT_OPENED:
3369         /* Start with first process attached, others detached */
3370         for (i = 0; i < s->process_num; i++) {
3371             s->processes[i].attached = !i;
3372         }
3373
3374         s->c_cpu = gdb_first_attached_cpu();
3375         s->g_cpu = s->c_cpu;
3376
3377         vm_stop(RUN_STATE_PAUSED);
3378         replay_gdb_attached();
3379         gdb_has_xml = false;
3380         break;
3381     default:
3382         break;
3383     }
3384 }
3385
3386 static int gdb_monitor_write(Chardev *chr, const uint8_t *buf, int len)
3387 {
3388     g_autoptr(GString) hex_buf = g_string_new("O");
3389     memtohex(hex_buf, buf, len);
3390     put_packet(hex_buf->str);
3391     return len;
3392 }
3393
3394 #ifndef _WIN32
3395 static void gdb_sigterm_handler(int signal)
3396 {
3397     if (runstate_is_running()) {
3398         vm_stop(RUN_STATE_PAUSED);
3399     }
3400 }
3401 #endif
3402
3403 static void gdb_monitor_open(Chardev *chr, ChardevBackend *backend,
3404                              bool *be_opened, Error **errp)
3405 {
3406     *be_opened = false;
3407 }
3408
3409 static void char_gdb_class_init(ObjectClass *oc, void *data)
3410 {
3411     ChardevClass *cc = CHARDEV_CLASS(oc);
3412
3413     cc->internal = true;
3414     cc->open = gdb_monitor_open;
3415     cc->chr_write = gdb_monitor_write;
3416 }
3417
3418 #define TYPE_CHARDEV_GDB "chardev-gdb"
3419
3420 static const TypeInfo char_gdb_type_info = {
3421     .name = TYPE_CHARDEV_GDB,
3422     .parent = TYPE_CHARDEV,
3423     .class_init = char_gdb_class_init,
3424 };
3425
3426 static int find_cpu_clusters(Object *child, void *opaque)
3427 {
3428     if (object_dynamic_cast(child, TYPE_CPU_CLUSTER)) {
3429         GDBState *s = (GDBState *) opaque;
3430         CPUClusterState *cluster = CPU_CLUSTER(child);
3431         GDBProcess *process;
3432
3433         s->processes = g_renew(GDBProcess, s->processes, ++s->process_num);
3434
3435         process = &s->processes[s->process_num - 1];
3436
3437         /*
3438          * GDB process IDs -1 and 0 are reserved. To avoid subtle errors at
3439          * runtime, we enforce here that the machine does not use a cluster ID
3440          * that would lead to PID 0.
3441          */
3442         assert(cluster->cluster_id != UINT32_MAX);
3443         process->pid = cluster->cluster_id + 1;
3444         process->attached = false;
3445         process->target_xml[0] = '\0';
3446
3447         return 0;
3448     }
3449
3450     return object_child_foreach(child, find_cpu_clusters, opaque);
3451 }
3452
3453 static int pid_order(const void *a, const void *b)
3454 {
3455     GDBProcess *pa = (GDBProcess *) a;
3456     GDBProcess *pb = (GDBProcess *) b;
3457
3458     if (pa->pid < pb->pid) {
3459         return -1;
3460     } else if (pa->pid > pb->pid) {
3461         return 1;
3462     } else {
3463         return 0;
3464     }
3465 }
3466
3467 static void create_processes(GDBState *s)
3468 {
3469     object_child_foreach(object_get_root(), find_cpu_clusters, s);
3470
3471     if (gdbserver_state.processes) {
3472         /* Sort by PID */
3473         qsort(gdbserver_state.processes, gdbserver_state.process_num, sizeof(gdbserver_state.processes[0]), pid_order);
3474     }
3475
3476     create_default_process(s);
3477 }
3478
3479 int gdbserver_start(const char *device)
3480 {
3481     trace_gdbstub_op_start(device);
3482
3483     char gdbstub_device_name[128];
3484     Chardev *chr = NULL;
3485     Chardev *mon_chr;
3486
3487     if (!first_cpu) {
3488         error_report("gdbstub: meaningless to attach gdb to a "
3489                      "machine without any CPU.");
3490         return -1;
3491     }
3492
3493     if (!device)
3494         return -1;
3495     if (strcmp(device, "none") != 0) {
3496         if (strstart(device, "tcp:", NULL)) {
3497             /* enforce required TCP attributes */
3498             snprintf(gdbstub_device_name, sizeof(gdbstub_device_name),
3499                      "%s,nowait,nodelay,server", device);
3500             device = gdbstub_device_name;
3501         }
3502 #ifndef _WIN32
3503         else if (strcmp(device, "stdio") == 0) {
3504             struct sigaction act;
3505
3506             memset(&act, 0, sizeof(act));
3507             act.sa_handler = gdb_sigterm_handler;
3508             sigaction(SIGINT, &act, NULL);
3509         }
3510 #endif
3511         /*
3512          * FIXME: it's a bit weird to allow using a mux chardev here
3513          * and implicitly setup a monitor. We may want to break this.
3514          */
3515         chr = qemu_chr_new_noreplay("gdb", device, true, NULL);
3516         if (!chr)
3517             return -1;
3518     }
3519
3520     if (!gdbserver_state.init) {
3521         init_gdbserver_state();
3522
3523         qemu_add_vm_change_state_handler(gdb_vm_state_change, NULL);
3524
3525         /* Initialize a monitor terminal for gdb */
3526         mon_chr = qemu_chardev_new(NULL, TYPE_CHARDEV_GDB,
3527                                    NULL, NULL, &error_abort);
3528         monitor_init_hmp(mon_chr, false, &error_abort);
3529     } else {
3530         qemu_chr_fe_deinit(&gdbserver_state.chr, true);
3531         mon_chr = gdbserver_state.mon_chr;
3532         reset_gdbserver_state();
3533     }
3534
3535     create_processes(&gdbserver_state);
3536
3537     if (chr) {
3538         qemu_chr_fe_init(&gdbserver_state.chr, chr, &error_abort);
3539         qemu_chr_fe_set_handlers(&gdbserver_state.chr, gdb_chr_can_receive,
3540                                  gdb_chr_receive, gdb_chr_event,
3541                                  NULL, &gdbserver_state, NULL, true);
3542     }
3543     gdbserver_state.state = chr ? RS_IDLE : RS_INACTIVE;
3544     gdbserver_state.mon_chr = mon_chr;
3545     gdbserver_state.current_syscall_cb = NULL;
3546
3547     return 0;
3548 }
3549
3550 void gdbserver_cleanup(void)
3551 {
3552     if (gdbserver_state.init) {
3553         put_packet("W00");
3554     }
3555 }
3556
3557 static void register_types(void)
3558 {
3559     type_register_static(&char_gdb_type_info);
3560 }
3561
3562 type_init(register_types);
3563 #endif