gdbstub.c

   1 /*
   2  * gdb server stub
   3  *
   4  * Copyright (c) 2003-2005 Fabrice Bellard
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
  18  */
  19 #include "config.h"
  20 #include "qemu-common.h"
  21 #ifdef CONFIG_USER_ONLY
  22 #include <stdlib.h>
  23 #include <stdio.h>
  24 #include <stdarg.h>
  25 #include <string.h>
  26 #include <errno.h>
  27 #include <unistd.h>
  28 #include <fcntl.h>
  29
  30 #include "qemu.h"
  31 #else
  32 #include "monitor/monitor.h"
  33 #include "sysemu/char.h"
  34 #include "sysemu/sysemu.h"
  35 #include "exec/gdbstub.h"
  36 #endif
  37
  38 #define MAX_PACKET_LENGTH 4096
  39
  40 #include "cpu.h"
  41 #include "qemu/sockets.h"
  42 #include "sysemu/kvm.h"
  43 #include "exec/semihost.h"
  44
  45 #ifdef CONFIG_USER_ONLY
  46 #define GDB_ATTACHED "0"
  47 #else
  48 #define GDB_ATTACHED "1"
  49 #endif
  50
  51 static inline int target_memory_rw_debug(CPUState *cpu, target_ulong addr,
  52                                          uint8_t *buf, int len, bool is_write)
  53 {
  54     CPUClass *cc = CPU_GET_CLASS(cpu);
  55
  56     if (cc->memory_rw_debug) {
  57         return cc->memory_rw_debug(cpu, addr, buf, len, is_write);
  58     }
  59     return cpu_memory_rw_debug(cpu, addr, buf, len, is_write);
  60 }
  61
  62 enum {
  63     GDB_SIGNAL_0 = 0,
  64     GDB_SIGNAL_INT = 2,
  65     GDB_SIGNAL_QUIT = 3,
  66     GDB_SIGNAL_TRAP = 5,
  67     GDB_SIGNAL_ABRT = 6,
  68     GDB_SIGNAL_ALRM = 14,
  69     GDB_SIGNAL_IO = 23,
  70     GDB_SIGNAL_XCPU = 24,
  71     GDB_SIGNAL_UNKNOWN = 143
  72 };
  73
  74 #ifdef CONFIG_USER_ONLY
  75
  76 /* Map target signal numbers to GDB protocol signal numbers and vice
  77  * versa.  For user emulation's currently supported systems, we can
  78  * assume most signals are defined.
  79  */
  80
  81 static int gdb_signal_table[] = {
  82     0,
  83     TARGET_SIGHUP,
  84     TARGET_SIGINT,
  85     TARGET_SIGQUIT,
  86     TARGET_SIGILL,
  87     TARGET_SIGTRAP,
  88     TARGET_SIGABRT,
  89     -1, /* SIGEMT */
  90     TARGET_SIGFPE,
  91     TARGET_SIGKILL,
  92     TARGET_SIGBUS,
  93     TARGET_SIGSEGV,
  94     TARGET_SIGSYS,
  95     TARGET_SIGPIPE,
  96     TARGET_SIGALRM,
  97     TARGET_SIGTERM,
  98     TARGET_SIGURG,
  99     TARGET_SIGSTOP,
 100     TARGET_SIGTSTP,
 101     TARGET_SIGCONT,
 102     TARGET_SIGCHLD,
 103     TARGET_SIGTTIN,
 104     TARGET_SIGTTOU,
 105     TARGET_SIGIO,
 106     TARGET_SIGXCPU,
 107     TARGET_SIGXFSZ,
 108     TARGET_SIGVTALRM,
 109     TARGET_SIGPROF,
 110     TARGET_SIGWINCH,
 111     -1, /* SIGLOST */
 112     TARGET_SIGUSR1,
 113     TARGET_SIGUSR2,
 114 #ifdef TARGET_SIGPWR
 115     TARGET_SIGPWR,
 116 #else
 117     -1,
 118 #endif
 119     -1, /* SIGPOLL */
 120     -1,
 121     -1,
 122     -1,
 123     -1,
 124     -1,
 125     -1,
 126     -1,
 127     -1,
 128     -1,
 129     -1,
 130     -1,
 131 #ifdef __SIGRTMIN
 132     __SIGRTMIN + 1,
 133     __SIGRTMIN + 2,
 134     __SIGRTMIN + 3,
 135     __SIGRTMIN + 4,
 136     __SIGRTMIN + 5,
 137     __SIGRTMIN + 6,
 138     __SIGRTMIN + 7,
 139     __SIGRTMIN + 8,
 140     __SIGRTMIN + 9,
 141     __SIGRTMIN + 10,
 142     __SIGRTMIN + 11,
 143     __SIGRTMIN + 12,
 144     __SIGRTMIN + 13,
 145     __SIGRTMIN + 14,
 146     __SIGRTMIN + 15,
 147     __SIGRTMIN + 16,
 148     __SIGRTMIN + 17,
 149     __SIGRTMIN + 18,
 150     __SIGRTMIN + 19,
 151     __SIGRTMIN + 20,
 152     __SIGRTMIN + 21,
 153     __SIGRTMIN + 22,
 154     __SIGRTMIN + 23,
 155     __SIGRTMIN + 24,
 156     __SIGRTMIN + 25,
 157     __SIGRTMIN + 26,
 158     __SIGRTMIN + 27,
 159     __SIGRTMIN + 28,
 160     __SIGRTMIN + 29,
 161     __SIGRTMIN + 30,
 162     __SIGRTMIN + 31,
 163     -1, /* SIGCANCEL */
 164     __SIGRTMIN,
 165     __SIGRTMIN + 32,
 166     __SIGRTMIN + 33,
 167     __SIGRTMIN + 34,
 168     __SIGRTMIN + 35,
 169     __SIGRTMIN + 36,
 170     __SIGRTMIN + 37,
 171     __SIGRTMIN + 38,
 172     __SIGRTMIN + 39,
 173     __SIGRTMIN + 40,
 174     __SIGRTMIN + 41,
 175     __SIGRTMIN + 42,
 176     __SIGRTMIN + 43,
 177     __SIGRTMIN + 44,
 178     __SIGRTMIN + 45,
 179     __SIGRTMIN + 46,
 180     __SIGRTMIN + 47,
 181     __SIGRTMIN + 48,
 182     __SIGRTMIN + 49,
 183     __SIGRTMIN + 50,
 184     __SIGRTMIN + 51,
 185     __SIGRTMIN + 52,
 186     __SIGRTMIN + 53,
 187     __SIGRTMIN + 54,
 188     __SIGRTMIN + 55,
 189     __SIGRTMIN + 56,
 190     __SIGRTMIN + 57,
 191     __SIGRTMIN + 58,
 192     __SIGRTMIN + 59,
 193     __SIGRTMIN + 60,
 194     __SIGRTMIN + 61,
 195     __SIGRTMIN + 62,
 196     __SIGRTMIN + 63,
 197     __SIGRTMIN + 64,
 198     __SIGRTMIN + 65,
 199     __SIGRTMIN + 66,
 200     __SIGRTMIN + 67,
 201     __SIGRTMIN + 68,
 202     __SIGRTMIN + 69,
 203     __SIGRTMIN + 70,
 204     __SIGRTMIN + 71,
 205     __SIGRTMIN + 72,
 206     __SIGRTMIN + 73,
 207     __SIGRTMIN + 74,
 208     __SIGRTMIN + 75,
 209     __SIGRTMIN + 76,
 210     __SIGRTMIN + 77,
 211     __SIGRTMIN + 78,
 212     __SIGRTMIN + 79,
 213     __SIGRTMIN + 80,
 214     __SIGRTMIN + 81,
 215     __SIGRTMIN + 82,
 216     __SIGRTMIN + 83,
 217     __SIGRTMIN + 84,
 218     __SIGRTMIN + 85,
 219     __SIGRTMIN + 86,
 220     __SIGRTMIN + 87,
 221     __SIGRTMIN + 88,
 222     __SIGRTMIN + 89,
 223     __SIGRTMIN + 90,
 224     __SIGRTMIN + 91,
 225     __SIGRTMIN + 92,
 226     __SIGRTMIN + 93,
 227     __SIGRTMIN + 94,
 228     __SIGRTMIN + 95,
 229     -1, /* SIGINFO */
 230     -1, /* UNKNOWN */
 231     -1, /* DEFAULT */
 232     -1,
 233     -1,
 234     -1,
 235     -1,
 236     -1,
 237     -1
 238 #endif
 239 };
 240 #else
 241 /* In system mode we only need SIGINT and SIGTRAP; other signals
 242    are not yet supported.  */
 243
 244 enum {
 245     TARGET_SIGINT = 2,
 246     TARGET_SIGTRAP = 5
 247 };
 248
 249 static int gdb_signal_table[] = {
 250     -1,
 251     -1,
 252     TARGET_SIGINT,
 253     -1,
 254     -1,
 255     TARGET_SIGTRAP
 256 };
 257 #endif
 258
 259 #ifdef CONFIG_USER_ONLY
 260 static int target_signal_to_gdb (int sig)
 261 {
 262     int i;
 263     for (i = 0; i < ARRAY_SIZE (gdb_signal_table); i++)
 264         if (gdb_signal_table[i] == sig)
 265             return i;
 266     return GDB_SIGNAL_UNKNOWN;
 267 }
 268 #endif
 269
 270 static int gdb_signal_to_target (int sig)
 271 {
 272     if (sig < ARRAY_SIZE (gdb_signal_table))
 273         return gdb_signal_table[sig];
 274     else
 275         return -1;
 276 }
 277
 278 //#define DEBUG_GDB
 279
 280 typedef struct GDBRegisterState {
 281     int base_reg;
 282     int num_regs;
 283     gdb_reg_cb get_reg;
 284     gdb_reg_cb set_reg;
 285     const char *xml;
 286     struct GDBRegisterState *next;
 287 } GDBRegisterState;
 288
 289 enum RSState {
 290     RS_INACTIVE,
 291     RS_IDLE,
 292     RS_GETLINE,
 293     RS_CHKSUM1,
 294     RS_CHKSUM2,
 295 };
 296 typedef struct GDBState {
 297     CPUState *c_cpu; /* current CPU for step/continue ops */
 298     CPUState *g_cpu; /* current CPU for other ops */
 299     CPUState *query_cpu; /* for q{f|s}ThreadInfo */
 300     enum RSState state; /* parsing state */
 301     char line_buf[MAX_PACKET_LENGTH];
 302     int line_buf_index;
 303     int line_csum;
 304     uint8_t last_packet[MAX_PACKET_LENGTH + 4];
 305     int last_packet_len;
 306     int signal;
 307 #ifdef CONFIG_USER_ONLY
 308     int fd;
 309     int running_state;
 310 #else
 311     CharDriverState *chr;
 312     CharDriverState *mon_chr;
 313 #endif
 314     char syscall_buf[256];
 315     gdb_syscall_complete_cb current_syscall_cb;
 316 } GDBState;
 317
 318 /* By default use no IRQs and no timers while single stepping so as to
 319  * make single stepping like an ICE HW step.
 320  */
 321 static int sstep_flags = SSTEP_ENABLE|SSTEP_NOIRQ|SSTEP_NOTIMER;
 322
 323 static GDBState *gdbserver_state;
 324
 325 bool gdb_has_xml;
 326
 327 #ifdef CONFIG_USER_ONLY
 328 /* XXX: This is not thread safe.  Do we care?  */
 329 static int gdbserver_fd = -1;
 330
 331 static int get_char(GDBState *s)
 332 {
 333     uint8_t ch;
 334     int ret;
 335
 336     for(;;) {
 337         ret = qemu_recv(s->fd, &ch, 1, 0);
 338         if (ret < 0) {
 339             if (errno == ECONNRESET)
 340                 s->fd = -1;
 341             if (errno != EINTR && errno != EAGAIN)
 342                 return -1;
 343         } else if (ret == 0) {
 344             close(s->fd);
 345             s->fd = -1;
 346             return -1;
 347         } else {
 348             break;
 349         }
 350     }
 351     return ch;
 352 }
 353 #endif
 354
 355 static enum {
 356     GDB_SYS_UNKNOWN,
 357     GDB_SYS_ENABLED,
 358     GDB_SYS_DISABLED,
 359 } gdb_syscall_mode;
 360
 361 /* Decide if either remote gdb syscalls or native file IO should be used. */
 362 int use_gdb_syscalls(void)
 363 {
 364     SemihostingTarget target = semihosting_get_target();
 365     if (target == SEMIHOSTING_TARGET_NATIVE) {
 366         /* -semihosting-config target=native */
 367         return false;
 368     } else if (target == SEMIHOSTING_TARGET_GDB) {
 369         /* -semihosting-config target=gdb */
 370         return true;
 371     }
 372
 373     /* -semihosting-config target=auto */
 374     /* On the first call check if gdb is connected and remember. */
 375     if (gdb_syscall_mode == GDB_SYS_UNKNOWN) {
 376         gdb_syscall_mode = (gdbserver_state ? GDB_SYS_ENABLED
 377                                             : GDB_SYS_DISABLED);
 378     }
 379     return gdb_syscall_mode == GDB_SYS_ENABLED;
 380 }
 381
 382 /* Resume execution.  */
 383 static inline void gdb_continue(GDBState *s)
 384 {
 385 #ifdef CONFIG_USER_ONLY
 386     s->running_state = 1;
 387 #else
 388     if (!runstate_needs_reset()) {
 389         vm_start();
 390     }
 391 #endif
 392 }
 393
 394 static void put_buffer(GDBState *s, const uint8_t *buf, int len)
 395 {
 396 #ifdef CONFIG_USER_ONLY
 397     int ret;
 398
 399     while (len > 0) {
 400         ret = send(s->fd, buf, len, 0);
 401         if (ret < 0) {
 402             if (errno != EINTR && errno != EAGAIN)
 403                 return;
 404         } else {
 405             buf += ret;
 406             len -= ret;
 407         }
 408     }
 409 #else
 410     qemu_chr_fe_write(s->chr, buf, len);
 411 #endif
 412 }
 413
 414 static inline int fromhex(int v)
 415 {
 416     if (v >= '0' && v <= '9')
 417         return v - '0';
 418     else if (v >= 'A' && v <= 'F')
 419         return v - 'A' + 10;
 420     else if (v >= 'a' && v <= 'f')
 421         return v - 'a' + 10;
 422     else
 423         return 0;
 424 }
 425
 426 static inline int tohex(int v)
 427 {
 428     if (v < 10)
 429         return v + '0';
 430     else
 431         return v - 10 + 'a';
 432 }
 433
 434 static void memtohex(char *buf, const uint8_t *mem, int len)
 435 {
 436     int i, c;
 437     char *q;
 438     q = buf;
 439     for(i = 0; i < len; i++) {
 440         c = mem[i];
 441         *q++ = tohex(c >> 4);
 442         *q++ = tohex(c & 0xf);
 443     }
 444     *q = '\0';
 445 }
 446
 447 static void hextomem(uint8_t *mem, const char *buf, int len)
 448 {
 449     int i;
 450
 451     for(i = 0; i < len; i++) {
 452         mem[i] = (fromhex(buf[0]) << 4) | fromhex(buf[1]);
 453         buf += 2;
 454     }
 455 }
 456
 457 /* return -1 if error, 0 if OK */
 458 static int put_packet_binary(GDBState *s, const char *buf, int len)
 459 {
 460     int csum, i;
 461     uint8_t *p;
 462
 463     for(;;) {
 464         p = s->last_packet;
 465         *(p++) = '$';
 466         memcpy(p, buf, len);
 467         p += len;
 468         csum = 0;
 469         for(i = 0; i < len; i++) {
 470             csum += buf[i];
 471         }
 472         *(p++) = '#';
 473         *(p++) = tohex((csum >> 4) & 0xf);
 474         *(p++) = tohex((csum) & 0xf);
 475
 476         s->last_packet_len = p - s->last_packet;
 477         put_buffer(s, (uint8_t *)s->last_packet, s->last_packet_len);
 478
 479 #ifdef CONFIG_USER_ONLY
 480         i = get_char(s);
 481         if (i < 0)
 482             return -1;
 483         if (i == '+')
 484             break;
 485 #else
 486         break;
 487 #endif
 488     }
 489     return 0;
 490 }
 491
 492 /* return -1 if error, 0 if OK */
 493 static int put_packet(GDBState *s, const char *buf)
 494 {
 495 #ifdef DEBUG_GDB
 496     printf("reply='%s'\n", buf);
 497 #endif
 498
 499     return put_packet_binary(s, buf, strlen(buf));
 500 }
 501
 502 /* Encode data using the encoding for 'x' packets.  */
 503 static int memtox(char *buf, const char *mem, int len)
 504 {
 505     char *p = buf;
 506     char c;
 507
 508     while (len--) {
 509         c = *(mem++);
 510         switch (c) {
 511         case '#': case '$': case '*': case '}':
 512             *(p++) = '}';
 513             *(p++) = c ^ 0x20;
 514             break;
 515         default:
 516             *(p++) = c;
 517             break;
 518         }
 519     }
 520     return p - buf;
 521 }
 522
 523 static const char *get_feature_xml(const char *p, const char **newp,
 524                                    CPUClass *cc)
 525 {
 526     size_t len;
 527     int i;
 528     const char *name;
 529     static char target_xml[1024];
 530
 531     len = 0;
 532     while (p[len] && p[len] != ':')
 533         len++;
 534     *newp = p + len;
 535
 536     name = NULL;
 537     if (strncmp(p, "target.xml", len) == 0) {
 538         /* Generate the XML description for this CPU.  */
 539         if (!target_xml[0]) {
 540             GDBRegisterState *r;
 541             CPUState *cpu = first_cpu;
 542
 543             snprintf(target_xml, sizeof(target_xml),
 544                      "<?xml version=\"1.0\"?>"
 545                      "<!DOCTYPE target SYSTEM \"gdb-target.dtd\">"
 546                      "<target>"
 547                      "<xi:include href=\"%s\"/>",
 548                      cc->gdb_core_xml_file);
 549
 550             for (r = cpu->gdb_regs; r; r = r->next) {
 551                 pstrcat(target_xml, sizeof(target_xml), "<xi:include href=\"");
 552                 pstrcat(target_xml, sizeof(target_xml), r->xml);
 553                 pstrcat(target_xml, sizeof(target_xml), "\"/>");
 554             }
 555             pstrcat(target_xml, sizeof(target_xml), "</target>");
 556         }
 557         return target_xml;
 558     }
 559     for (i = 0; ; i++) {
 560         name = xml_builtin[i][0];
 561         if (!name || (strncmp(name, p, len) == 0 && strlen(name) == len))
 562             break;
 563     }
 564     return name ? xml_builtin[i][1] : NULL;
 565 }
 566
 567 static int gdb_read_register(CPUState *cpu, uint8_t *mem_buf, int reg)
 568 {
 569     CPUClass *cc = CPU_GET_CLASS(cpu);
 570     CPUArchState *env = cpu->env_ptr;
 571     GDBRegisterState *r;
 572
 573     if (reg < cc->gdb_num_core_regs) {
 574         return cc->gdb_read_register(cpu, mem_buf, reg);
 575     }
 576
 577     for (r = cpu->gdb_regs; r; r = r->next) {
 578         if (r->base_reg <= reg && reg < r->base_reg + r->num_regs) {
 579             return r->get_reg(env, mem_buf, reg - r->base_reg);
 580         }
 581     }
 582     return 0;
 583 }
 584
 585 static int gdb_write_register(CPUState *cpu, uint8_t *mem_buf, int reg)
 586 {
 587     CPUClass *cc = CPU_GET_CLASS(cpu);
 588     CPUArchState *env = cpu->env_ptr;
 589     GDBRegisterState *r;
 590
 591     if (reg < cc->gdb_num_core_regs) {
 592         return cc->gdb_write_register(cpu, mem_buf, reg);
 593     }
 594
 595     for (r = cpu->gdb_regs; r; r = r->next) {
 596         if (r->base_reg <= reg && reg < r->base_reg + r->num_regs) {
 597             return r->set_reg(env, mem_buf, reg - r->base_reg);
 598         }
 599     }
 600     return 0;
 601 }
 602
 603 /* Register a supplemental set of CPU registers.  If g_pos is nonzero it
 604    specifies the first register number and these registers are included in
 605    a standard "g" packet.  Direction is relative to gdb, i.e. get_reg is
 606    gdb reading a CPU register, and set_reg is gdb modifying a CPU register.
 607  */
 608
 609 void gdb_register_coprocessor(CPUState *cpu,
 610                               gdb_reg_cb get_reg, gdb_reg_cb set_reg,
 611                               int num_regs, const char *xml, int g_pos)
 612 {
 613     GDBRegisterState *s;
 614     GDBRegisterState **p;
 615
 616     p = &cpu->gdb_regs;
 617     while (*p) {
 618         /* Check for duplicates.  */
 619         if (strcmp((*p)->xml, xml) == 0)
 620             return;
 621         p = &(*p)->next;
 622     }
 623
 624     s = g_new0(GDBRegisterState, 1);
 625     s->base_reg = cpu->gdb_num_regs;
 626     s->num_regs = num_regs;
 627     s->get_reg = get_reg;
 628     s->set_reg = set_reg;
 629     s->xml = xml;
 630
 631     /* Add to end of list.  */
 632     cpu->gdb_num_regs += num_regs;
 633     *p = s;
 634     if (g_pos) {
 635         if (g_pos != s->base_reg) {
 636             fprintf(stderr, "Error: Bad gdb register numbering for '%s'\n"
 637                     "Expected %d got %d\n", xml, g_pos, s->base_reg);
 638         } else {
 639             cpu->gdb_num_g_regs = cpu->gdb_num_regs;
 640         }
 641     }
 642 }
 643
 644 #ifndef CONFIG_USER_ONLY
 645 /* Translate GDB watchpoint type to a flags value for cpu_watchpoint_* */
 646 static inline int xlat_gdb_type(CPUState *cpu, int gdbtype)
 647 {
 648     static const int xlat[] = {
 649         [GDB_WATCHPOINT_WRITE]  = BP_GDB | BP_MEM_WRITE,
 650         [GDB_WATCHPOINT_READ]   = BP_GDB | BP_MEM_READ,
 651         [GDB_WATCHPOINT_ACCESS] = BP_GDB | BP_MEM_ACCESS,
 652     };
 653
 654     CPUClass *cc = CPU_GET_CLASS(cpu);
 655     int cputype = xlat[gdbtype];
 656
 657     if (cc->gdb_stop_before_watchpoint) {
 658         cputype |= BP_STOP_BEFORE_ACCESS;
 659     }
 660     return cputype;
 661 }
 662 #endif
 663
 664 static int gdb_breakpoint_insert(target_ulong addr, target_ulong len, int type)
 665 {
 666     CPUState *cpu;
 667     int err = 0;
 668
 669     if (kvm_enabled()) {
 670         return kvm_insert_breakpoint(gdbserver_state->c_cpu, addr, len, type);
 671     }
 672
 673     switch (type) {
 674     case GDB_BREAKPOINT_SW:
 675     case GDB_BREAKPOINT_HW:
 676         CPU_FOREACH(cpu) {
 677             err = cpu_breakpoint_insert(cpu, addr, BP_GDB, NULL);
 678             if (err) {
 679                 break;
 680             }
 681         }
 682         return err;
 683 #ifndef CONFIG_USER_ONLY
 684     case GDB_WATCHPOINT_WRITE:
 685     case GDB_WATCHPOINT_READ:
 686     case GDB_WATCHPOINT_ACCESS:
 687         CPU_FOREACH(cpu) {
 688             err = cpu_watchpoint_insert(cpu, addr, len,
 689                                         xlat_gdb_type(cpu, type), NULL);
 690             if (err) {
 691                 break;
 692             }
 693         }
 694         return err;
 695 #endif
 696     default:
 697         return -ENOSYS;
 698     }
 699 }
 700
 701 static int gdb_breakpoint_remove(target_ulong addr, target_ulong len, int type)
 702 {
 703     CPUState *cpu;
 704     int err = 0;
 705
 706     if (kvm_enabled()) {
 707         return kvm_remove_breakpoint(gdbserver_state->c_cpu, addr, len, type);
 708     }
 709
 710     switch (type) {
 711     case GDB_BREAKPOINT_SW:
 712     case GDB_BREAKPOINT_HW:
 713         CPU_FOREACH(cpu) {
 714             err = cpu_breakpoint_remove(cpu, addr, BP_GDB);
 715             if (err) {
 716                 break;
 717             }
 718         }
 719         return err;
 720 #ifndef CONFIG_USER_ONLY
 721     case GDB_WATCHPOINT_WRITE:
 722     case GDB_WATCHPOINT_READ:
 723     case GDB_WATCHPOINT_ACCESS:
 724         CPU_FOREACH(cpu) {
 725             err = cpu_watchpoint_remove(cpu, addr, len,
 726                                         xlat_gdb_type(cpu, type));
 727             if (err)
 728                 break;
 729         }
 730         return err;
 731 #endif
 732     default:
 733         return -ENOSYS;
 734     }
 735 }
 736
 737 static void gdb_breakpoint_remove_all(void)
 738 {
 739     CPUState *cpu;
 740
 741     if (kvm_enabled()) {
 742         kvm_remove_all_breakpoints(gdbserver_state->c_cpu);
 743         return;
 744     }
 745
 746     CPU_FOREACH(cpu) {
 747         cpu_breakpoint_remove_all(cpu, BP_GDB);
 748 #ifndef CONFIG_USER_ONLY
 749         cpu_watchpoint_remove_all(cpu, BP_GDB);
 750 #endif
 751     }
 752 }
 753
 754 static void gdb_set_cpu_pc(GDBState *s, target_ulong pc)
 755 {
 756     CPUState *cpu = s->c_cpu;
 757
 758     cpu_synchronize_state(cpu);
 759     cpu_set_pc(cpu, pc);
 760 }
 761
 762 static CPUState *find_cpu(uint32_t thread_id)
 763 {
 764     CPUState *cpu;
 765
 766     CPU_FOREACH(cpu) {
 767         if (cpu_index(cpu) == thread_id) {
 768             return cpu;
 769         }
 770     }
 771
 772     return NULL;
 773 }
 774
 775 static int is_query_packet(const char *p, const char *query, char separator)
 776 {
 777     unsigned int query_len = strlen(query);
 778
 779     return strncmp(p, query, query_len) == 0 &&
 780         (p[query_len] == '\0' || p[query_len] == separator);
 781 }
 782
 783 static int gdb_handle_packet(GDBState *s, const char *line_buf)
 784 {
 785     CPUState *cpu;
 786     CPUClass *cc;
 787     const char *p;
 788     uint32_t thread;
 789     int ch, reg_size, type, res;
 790     char buf[MAX_PACKET_LENGTH];
 791     uint8_t mem_buf[MAX_PACKET_LENGTH];
 792     uint8_t *registers;
 793     target_ulong addr, len;
 794
 795 #ifdef DEBUG_GDB
 796     printf("command='%s'\n", line_buf);
 797 #endif
 798     p = line_buf;
 799     ch = *p++;
 800     switch(ch) {
 801     case '?':
 802         /* TODO: Make this return the correct value for user-mode.  */
 803         snprintf(buf, sizeof(buf), "T%02xthread:%02x;", GDB_SIGNAL_TRAP,
 804                  cpu_index(s->c_cpu));
 805         put_packet(s, buf);
 806         /* Remove all the breakpoints when this query is issued,
 807          * because gdb is doing and initial connect and the state
 808          * should be cleaned up.
 809          */
 810         gdb_breakpoint_remove_all();
 811         break;
 812     case 'c':
 813         if (*p != '\0') {
 814             addr = strtoull(p, (char **)&p, 16);
 815             gdb_set_cpu_pc(s, addr);
 816         }
 817         s->signal = 0;
 818         gdb_continue(s);
 819         return RS_IDLE;
 820     case 'C':
 821         s->signal = gdb_signal_to_target (strtoul(p, (char **)&p, 16));
 822         if (s->signal == -1)
 823             s->signal = 0;
 824         gdb_continue(s);
 825         return RS_IDLE;
 826     case 'v':
 827         if (strncmp(p, "Cont", 4) == 0) {
 828             int res_signal, res_thread;
 829
 830             p += 4;
 831             if (*p == '?') {
 832                 put_packet(s, "vCont;c;C;s;S");
 833                 break;
 834             }
 835             res = 0;
 836             res_signal = 0;
 837             res_thread = 0;
 838             while (*p) {
 839                 int action, signal;
 840
 841                 if (*p++ != ';') {
 842                     res = 0;
 843                     break;
 844                 }
 845                 action = *p++;
 846                 signal = 0;
 847                 if (action == 'C' || action == 'S') {
 848                     signal = gdb_signal_to_target(strtoul(p, (char **)&p, 16));
 849                     if (signal == -1) {
 850                         signal = 0;
 851                     }
 852                 } else if (action != 'c' && action != 's') {
 853                     res = 0;
 854                     break;
 855                 }
 856                 thread = 0;
 857                 if (*p == ':') {
 858                     thread = strtoull(p+1, (char **)&p, 16);
 859                 }
 860                 action = tolower(action);
 861                 if (res == 0 || (res == 'c' && action == 's')) {
 862                     res = action;
 863                     res_signal = signal;
 864                     res_thread = thread;
 865                 }
 866             }
 867             if (res) {
 868                 if (res_thread != -1 && res_thread != 0) {
 869                     cpu = find_cpu(res_thread);
 870                     if (cpu == NULL) {
 871                         put_packet(s, "E22");
 872                         break;
 873                     }
 874                     s->c_cpu = cpu;
 875                 }
 876                 if (res == 's') {
 877                     cpu_single_step(s->c_cpu, sstep_flags);
 878                 }
 879                 s->signal = res_signal;
 880                 gdb_continue(s);
 881                 return RS_IDLE;
 882             }
 883             break;
 884         } else {
 885             goto unknown_command;
 886         }
 887     case 'k':
 888         /* Kill the target */
 889         fprintf(stderr, "\nQEMU: Terminated via GDBstub\n");
 890         exit(0);
 891     case 'D':
 892         /* Detach packet */
 893         gdb_breakpoint_remove_all();
 894         gdb_syscall_mode = GDB_SYS_DISABLED;
 895         gdb_continue(s);
 896         put_packet(s, "OK");
 897         break;
 898     case 's':
 899         if (*p != '\0') {
 900             addr = strtoull(p, (char **)&p, 16);
 901             gdb_set_cpu_pc(s, addr);
 902         }
 903         cpu_single_step(s->c_cpu, sstep_flags);
 904         gdb_continue(s);
 905         return RS_IDLE;
 906     case 'F':
 907         {
 908             target_ulong ret;
 909             target_ulong err;
 910
 911             ret = strtoull(p, (char **)&p, 16);
 912             if (*p == ',') {
 913                 p++;
 914                 err = strtoull(p, (char **)&p, 16);
 915             } else {
 916                 err = 0;
 917             }
 918             if (*p == ',')
 919                 p++;
 920             type = *p;
 921             if (s->current_syscall_cb) {
 922                 s->current_syscall_cb(s->c_cpu, ret, err);
 923                 s->current_syscall_cb = NULL;
 924             }
 925             if (type == 'C') {
 926                 put_packet(s, "T02");
 927             } else {
 928                 gdb_continue(s);
 929             }
 930         }
 931         break;
 932     case 'g':
 933         cpu_synchronize_state(s->g_cpu);
 934         len = 0;
 935         for (addr = 0; addr < s->g_cpu->gdb_num_g_regs; addr++) {
 936             reg_size = gdb_read_register(s->g_cpu, mem_buf + len, addr);
 937             len += reg_size;
 938         }
 939         memtohex(buf, mem_buf, len);
 940         put_packet(s, buf);
 941         break;
 942     case 'G':
 943         cpu_synchronize_state(s->g_cpu);
 944         registers = mem_buf;
 945         len = strlen(p) / 2;
 946         hextomem((uint8_t *)registers, p, len);
 947         for (addr = 0; addr < s->g_cpu->gdb_num_g_regs && len > 0; addr++) {
 948             reg_size = gdb_write_register(s->g_cpu, registers, addr);
 949             len -= reg_size;
 950             registers += reg_size;
 951         }
 952         put_packet(s, "OK");
 953         break;
 954     case 'm':
 955         addr = strtoull(p, (char **)&p, 16);
 956         if (*p == ',')
 957             p++;
 958         len = strtoull(p, NULL, 16);
 959         if (target_memory_rw_debug(s->g_cpu, addr, mem_buf, len, false) != 0) {
 960             put_packet (s, "E14");
 961         } else {
 962             memtohex(buf, mem_buf, len);
 963             put_packet(s, buf);
 964         }
 965         break;
 966     case 'M':
 967         addr = strtoull(p, (char **)&p, 16);
 968         if (*p == ',')
 969             p++;
 970         len = strtoull(p, (char **)&p, 16);
 971         if (*p == ':')
 972             p++;
 973         hextomem(mem_buf, p, len);
 974         if (target_memory_rw_debug(s->g_cpu, addr, mem_buf, len,
 975                                    true) != 0) {
 976             put_packet(s, "E14");
 977         } else {
 978             put_packet(s, "OK");
 979         }
 980         break;
 981     case 'p':
 982         /* Older gdb are really dumb, and don't use 'g' if 'p' is avaialable.
 983            This works, but can be very slow.  Anything new enough to
 984            understand XML also knows how to use this properly.  */
 985         if (!gdb_has_xml)
 986             goto unknown_command;
 987         addr = strtoull(p, (char **)&p, 16);
 988         reg_size = gdb_read_register(s->g_cpu, mem_buf, addr);
 989         if (reg_size) {
 990             memtohex(buf, mem_buf, reg_size);
 991             put_packet(s, buf);
 992         } else {
 993             put_packet(s, "E14");
 994         }
 995         break;
 996     case 'P':
 997         if (!gdb_has_xml)
 998             goto unknown_command;
 999         addr = strtoull(p, (char **)&p, 16);
1000         if (*p == '=')
1001             p++;
1002         reg_size = strlen(p) / 2;
1003         hextomem(mem_buf, p, reg_size);
1004         gdb_write_register(s->g_cpu, mem_buf, addr);
1005         put_packet(s, "OK");
1006         break;
1007     case 'Z':
1008     case 'z':
1009         type = strtoul(p, (char **)&p, 16);
1010         if (*p == ',')
1011             p++;
1012         addr = strtoull(p, (char **)&p, 16);
1013         if (*p == ',')
1014             p++;
1015         len = strtoull(p, (char **)&p, 16);
1016         if (ch == 'Z')
1017             res = gdb_breakpoint_insert(addr, len, type);
1018         else
1019             res = gdb_breakpoint_remove(addr, len, type);
1020         if (res >= 0)
1021              put_packet(s, "OK");
1022         else if (res == -ENOSYS)
1023             put_packet(s, "");
1024         else
1025             put_packet(s, "E22");
1026         break;
1027     case 'H':
1028         type = *p++;
1029         thread = strtoull(p, (char **)&p, 16);
1030         if (thread == -1 || thread == 0) {
1031             put_packet(s, "OK");
1032             break;
1033         }
1034         cpu = find_cpu(thread);
1035         if (cpu == NULL) {
1036             put_packet(s, "E22");
1037             break;
1038         }
1039         switch (type) {
1040         case 'c':
1041             s->c_cpu = cpu;
1042             put_packet(s, "OK");
1043             break;
1044         case 'g':
1045             s->g_cpu = cpu;
1046             put_packet(s, "OK");
1047             break;
1048         default:
1049              put_packet(s, "E22");
1050              break;
1051         }
1052         break;
1053     case 'T':
1054         thread = strtoull(p, (char **)&p, 16);
1055         cpu = find_cpu(thread);
1056
1057         if (cpu != NULL) {
1058             put_packet(s, "OK");
1059         } else {
1060             put_packet(s, "E22");
1061         }
1062         break;
1063     case 'q':
1064     case 'Q':
1065         /* parse any 'q' packets here */
1066         if (!strcmp(p,"qemu.sstepbits")) {
1067             /* Query Breakpoint bit definitions */
1068             snprintf(buf, sizeof(buf), "ENABLE=%x,NOIRQ=%x,NOTIMER=%x",
1069                      SSTEP_ENABLE,
1070                      SSTEP_NOIRQ,
1071                      SSTEP_NOTIMER);
1072             put_packet(s, buf);
1073             break;
1074         } else if (is_query_packet(p, "qemu.sstep", '=')) {
1075             /* Display or change the sstep_flags */
1076             p += 10;
1077             if (*p != '=') {
1078                 /* Display current setting */
1079                 snprintf(buf, sizeof(buf), "0x%x", sstep_flags);
1080                 put_packet(s, buf);
1081                 break;
1082             }
1083             p++;
1084             type = strtoul(p, (char **)&p, 16);
1085             sstep_flags = type;
1086             put_packet(s, "OK");
1087             break;
1088         } else if (strcmp(p,"C") == 0) {
1089             /* "Current thread" remains vague in the spec, so always return
1090              *  the first CPU (gdb returns the first thread). */
1091             put_packet(s, "QC1");
1092             break;
1093         } else if (strcmp(p,"fThreadInfo") == 0) {
1094             s->query_cpu = first_cpu;
1095             goto report_cpuinfo;
1096         } else if (strcmp(p,"sThreadInfo") == 0) {
1097         report_cpuinfo:
1098             if (s->query_cpu) {
1099                 snprintf(buf, sizeof(buf), "m%x", cpu_index(s->query_cpu));
1100                 put_packet(s, buf);
1101                 s->query_cpu = CPU_NEXT(s->query_cpu);
1102             } else
1103                 put_packet(s, "l");
1104             break;
1105         } else if (strncmp(p,"ThreadExtraInfo,", 16) == 0) {
1106             thread = strtoull(p+16, (char **)&p, 16);
1107             cpu = find_cpu(thread);
1108             if (cpu != NULL) {
1109                 cpu_synchronize_state(cpu);
1110                 len = snprintf((char *)mem_buf, sizeof(mem_buf),
1111                                "CPU#%d [%s]", cpu->cpu_index,
1112                                cpu->halted ? "halted " : "running");
1113                 memtohex(buf, mem_buf, len);
1114                 put_packet(s, buf);
1115             }
1116             break;
1117         }
1118 #ifdef CONFIG_USER_ONLY
1119         else if (strcmp(p, "Offsets") == 0) {
1120             TaskState *ts = s->c_cpu->opaque;
1121
1122             snprintf(buf, sizeof(buf),
1123                      "Text=" TARGET_ABI_FMT_lx ";Data=" TARGET_ABI_FMT_lx
1124                      ";Bss=" TARGET_ABI_FMT_lx,
1125                      ts->info->code_offset,
1126                      ts->info->data_offset,
1127                      ts->info->data_offset);
1128             put_packet(s, buf);
1129             break;
1130         }
1131 #else /* !CONFIG_USER_ONLY */
1132         else if (strncmp(p, "Rcmd,", 5) == 0) {
1133             int len = strlen(p + 5);
1134
1135             if ((len % 2) != 0) {
1136                 put_packet(s, "E01");
1137                 break;
1138             }
1139             hextomem(mem_buf, p + 5, len);
1140             len = len / 2;
1141             mem_buf[len++] = 0;
1142             qemu_chr_be_write(s->mon_chr, mem_buf, len);
1143             put_packet(s, "OK");
1144             break;
1145         }
1146 #endif /* !CONFIG_USER_ONLY */
1147         if (is_query_packet(p, "Supported", ':')) {
1148             snprintf(buf, sizeof(buf), "PacketSize=%x", MAX_PACKET_LENGTH);
1149             cc = CPU_GET_CLASS(first_cpu);
1150             if (cc->gdb_core_xml_file != NULL) {
1151                 pstrcat(buf, sizeof(buf), ";qXfer:features:read+");
1152             }
1153             put_packet(s, buf);
1154             break;
1155         }
1156         if (strncmp(p, "Xfer:features:read:", 19) == 0) {
1157             const char *xml;
1158             target_ulong total_len;
1159
1160             cc = CPU_GET_CLASS(first_cpu);
1161             if (cc->gdb_core_xml_file == NULL) {
1162                 goto unknown_command;
1163             }
1164
1165             gdb_has_xml = true;
1166             p += 19;
1167             xml = get_feature_xml(p, &p, cc);
1168             if (!xml) {
1169                 snprintf(buf, sizeof(buf), "E00");
1170                 put_packet(s, buf);
1171                 break;
1172             }
1173
1174             if (*p == ':')
1175                 p++;
1176             addr = strtoul(p, (char **)&p, 16);
1177             if (*p == ',')
1178                 p++;
1179             len = strtoul(p, (char **)&p, 16);
1180
1181             total_len = strlen(xml);
1182             if (addr > total_len) {
1183                 snprintf(buf, sizeof(buf), "E00");
1184                 put_packet(s, buf);
1185                 break;
1186             }
1187             if (len > (MAX_PACKET_LENGTH - 5) / 2)
1188                 len = (MAX_PACKET_LENGTH - 5) / 2;
1189             if (len < total_len - addr) {
1190                 buf[0] = 'm';
1191                 len = memtox(buf + 1, xml + addr, len);
1192             } else {
1193                 buf[0] = 'l';
1194                 len = memtox(buf + 1, xml + addr, total_len - addr);
1195             }
1196             put_packet_binary(s, buf, len + 1);
1197             break;
1198         }
1199         if (is_query_packet(p, "Attached", ':')) {
1200             put_packet(s, GDB_ATTACHED);
1201             break;
1202         }
1203         /* Unrecognised 'q' command.  */
1204         goto unknown_command;
1205
1206     default:
1207     unknown_command:
1208         /* put empty packet */
1209         buf[0] = '\0';
1210         put_packet(s, buf);
1211         break;
1212     }
1213     return RS_IDLE;
1214 }
1215
1216 void gdb_set_stop_cpu(CPUState *cpu)
1217 {
1218     gdbserver_state->c_cpu = cpu;
1219     gdbserver_state->g_cpu = cpu;
1220 }
1221
1222 #ifndef CONFIG_USER_ONLY
1223 static void gdb_vm_state_change(void *opaque, int running, RunState state)
1224 {
1225     GDBState *s = gdbserver_state;
1226     CPUState *cpu = s->c_cpu;
1227     char buf[256];
1228     const char *type;
1229     int ret;
1230
1231     if (running || s->state == RS_INACTIVE) {
1232         return;
1233     }
1234     /* Is there a GDB syscall waiting to be sent?  */
1235     if (s->current_syscall_cb) {
1236         put_packet(s, s->syscall_buf);
1237         return;
1238     }
1239     switch (state) {
1240     case RUN_STATE_DEBUG:
1241         if (cpu->watchpoint_hit) {
1242             switch (cpu->watchpoint_hit->flags & BP_MEM_ACCESS) {
1243             case BP_MEM_READ:
1244                 type = "r";
1245                 break;
1246             case BP_MEM_ACCESS:
1247                 type = "a";
1248                 break;
1249             default:
1250                 type = "";
1251                 break;
1252             }
1253             snprintf(buf, sizeof(buf),
1254                      "T%02xthread:%02x;%swatch:" TARGET_FMT_lx ";",
1255                      GDB_SIGNAL_TRAP, cpu_index(cpu), type,
1256                      (target_ulong)cpu->watchpoint_hit->vaddr);
1257             cpu->watchpoint_hit = NULL;
1258             goto send_packet;
1259         }
1260         tb_flush(cpu);
1261         ret = GDB_SIGNAL_TRAP;
1262         break;
1263     case RUN_STATE_PAUSED:
1264         ret = GDB_SIGNAL_INT;
1265         break;
1266     case RUN_STATE_SHUTDOWN:
1267         ret = GDB_SIGNAL_QUIT;
1268         break;
1269     case RUN_STATE_IO_ERROR:
1270         ret = GDB_SIGNAL_IO;
1271         break;
1272     case RUN_STATE_WATCHDOG:
1273         ret = GDB_SIGNAL_ALRM;
1274         break;
1275     case RUN_STATE_INTERNAL_ERROR:
1276         ret = GDB_SIGNAL_ABRT;
1277         break;
1278     case RUN_STATE_SAVE_VM:
1279     case RUN_STATE_RESTORE_VM:
1280         return;
1281     case RUN_STATE_FINISH_MIGRATE:
1282         ret = GDB_SIGNAL_XCPU;
1283         break;
1284     default:
1285         ret = GDB_SIGNAL_UNKNOWN;
1286         break;
1287     }
1288     gdb_set_stop_cpu(cpu);
1289     snprintf(buf, sizeof(buf), "T%02xthread:%02x;", ret, cpu_index(cpu));
1290
1291 send_packet:
1292     put_packet(s, buf);
1293
1294     /* disable single step if it was enabled */
1295     cpu_single_step(cpu, 0);
1296 }
1297 #endif
1298
1299 /* Send a gdb syscall request.
1300    This accepts limited printf-style format specifiers, specifically:
1301     %x  - target_ulong argument printed in hex.
1302     %lx - 64-bit argument printed in hex.
1303     %s  - string pointer (target_ulong) and length (int) pair.  */
1304 void gdb_do_syscallv(gdb_syscall_complete_cb cb, const char *fmt, va_list va)
1305 {
1306     char *p;
1307     char *p_end;
1308     target_ulong addr;
1309     uint64_t i64;
1310     GDBState *s;
1311
1312     s = gdbserver_state;
1313     if (!s)
1314         return;
1315     s->current_syscall_cb = cb;
1316 #ifndef CONFIG_USER_ONLY
1317     vm_stop(RUN_STATE_DEBUG);
1318 #endif
1319     p = s->syscall_buf;
1320     p_end = &s->syscall_buf[sizeof(s->syscall_buf)];
1321     *(p++) = 'F';
1322     while (*fmt) {
1323         if (*fmt == '%') {
1324             fmt++;
1325             switch (*fmt++) {
1326             case 'x':
1327                 addr = va_arg(va, target_ulong);
1328                 p += snprintf(p, p_end - p, TARGET_FMT_lx, addr);
1329                 break;
1330             case 'l':
1331                 if (*(fmt++) != 'x')
1332                     goto bad_format;
1333                 i64 = va_arg(va, uint64_t);
1334                 p += snprintf(p, p_end - p, "%" PRIx64, i64);
1335                 break;
1336             case 's':
1337                 addr = va_arg(va, target_ulong);
1338                 p += snprintf(p, p_end - p, TARGET_FMT_lx "/%x",
1339                               addr, va_arg(va, int));
1340                 break;
1341             default:
1342             bad_format:
1343                 fprintf(stderr, "gdbstub: Bad syscall format string '%s'\n",
1344                         fmt - 1);
1345                 break;
1346             }
1347         } else {
1348             *(p++) = *(fmt++);
1349         }
1350     }
1351     *p = 0;
1352 #ifdef CONFIG_USER_ONLY
1353     put_packet(s, s->syscall_buf);
1354     gdb_handlesig(s->c_cpu, 0);
1355 #else
1356     /* In this case wait to send the syscall packet until notification that
1357        the CPU has stopped.  This must be done because if the packet is sent
1358        now the reply from the syscall request could be received while the CPU
1359        is still in the running state, which can cause packets to be dropped
1360        and state transition 'T' packets to be sent while the syscall is still
1361        being processed.  */
1362     cpu_exit(s->c_cpu);
1363 #endif
1364 }
1365
1366 void gdb_do_syscall(gdb_syscall_complete_cb cb, const char *fmt, ...)
1367 {
1368     va_list va;
1369
1370     va_start(va, fmt);
1371     gdb_do_syscallv(cb, fmt, va);
1372     va_end(va);
1373 }
1374
1375 static void gdb_read_byte(GDBState *s, int ch)
1376 {
1377     int i, csum;
1378     uint8_t reply;
1379
1380 #ifndef CONFIG_USER_ONLY
1381     if (s->last_packet_len) {
1382         /* Waiting for a response to the last packet.  If we see the start
1383            of a new command then abandon the previous response.  */
1384         if (ch == '-') {
1385 #ifdef DEBUG_GDB
1386             printf("Got NACK, retransmitting\n");
1387 #endif
1388             put_buffer(s, (uint8_t *)s->last_packet, s->last_packet_len);
1389         }
1390 #ifdef DEBUG_GDB
1391         else if (ch == '+')
1392             printf("Got ACK\n");
1393         else
1394             printf("Got '%c' when expecting ACK/NACK\n", ch);
1395 #endif
1396         if (ch == '+' || ch == '$')
1397             s->last_packet_len = 0;
1398         if (ch != '$')
1399             return;
1400     }
1401     if (runstate_is_running()) {
1402         /* when the CPU is running, we cannot do anything except stop
1403            it when receiving a char */
1404         vm_stop(RUN_STATE_PAUSED);
1405     } else
1406 #endif
1407     {
1408         switch(s->state) {
1409         case RS_IDLE:
1410             if (ch == '$') {
1411                 s->line_buf_index = 0;
1412                 s->state = RS_GETLINE;
1413             }
1414             break;
1415         case RS_GETLINE:
1416             if (ch == '#') {
1417             s->state = RS_CHKSUM1;
1418             } else if (s->line_buf_index >= sizeof(s->line_buf) - 1) {
1419                 s->state = RS_IDLE;
1420             } else {
1421             s->line_buf[s->line_buf_index++] = ch;
1422             }
1423             break;
1424         case RS_CHKSUM1:
1425             s->line_buf[s->line_buf_index] = '\0';
1426             s->line_csum = fromhex(ch) << 4;
1427             s->state = RS_CHKSUM2;
1428             break;
1429         case RS_CHKSUM2:
1430             s->line_csum |= fromhex(ch);
1431             csum = 0;
1432             for(i = 0; i < s->line_buf_index; i++) {
1433                 csum += s->line_buf[i];
1434             }
1435             if (s->line_csum != (csum & 0xff)) {
1436                 reply = '-';
1437                 put_buffer(s, &reply, 1);
1438                 s->state = RS_IDLE;
1439             } else {
1440                 reply = '+';
1441                 put_buffer(s, &reply, 1);
1442                 s->state = gdb_handle_packet(s, s->line_buf);
1443             }
1444             break;
1445         default:
1446             abort();
1447         }
1448     }
1449 }
1450
1451 /* Tell the remote gdb that the process has exited.  */
1452 void gdb_exit(CPUArchState *env, int code)
1453 {
1454   GDBState *s;
1455   char buf[4];
1456
1457   s = gdbserver_state;
1458   if (!s) {
1459       return;
1460   }
1461 #ifdef CONFIG_USER_ONLY
1462   if (gdbserver_fd < 0 || s->fd < 0) {
1463       return;
1464   }
1465 #else
1466   if (!s->chr) {
1467       return;
1468   }
1469 #endif
1470
1471   snprintf(buf, sizeof(buf), "W%02x", (uint8_t)code);
1472   put_packet(s, buf);
1473
1474 #ifndef CONFIG_USER_ONLY
1475   qemu_chr_delete(s->chr);
1476 #endif
1477 }
1478
1479 #ifdef CONFIG_USER_ONLY
1480 int
1481 gdb_queuesig (void)
1482 {
1483     GDBState *s;
1484
1485     s = gdbserver_state;
1486
1487     if (gdbserver_fd < 0 || s->fd < 0)
1488         return 0;
1489     else
1490         return 1;
1491 }
1492
1493 int
1494 gdb_handlesig(CPUState *cpu, int sig)
1495 {
1496     GDBState *s;
1497     char buf[256];
1498     int n;
1499
1500     s = gdbserver_state;
1501     if (gdbserver_fd < 0 || s->fd < 0) {
1502         return sig;
1503     }
1504
1505     /* disable single step if it was enabled */
1506     cpu_single_step(cpu, 0);
1507     tb_flush(cpu);
1508
1509     if (sig != 0) {
1510         snprintf(buf, sizeof(buf), "S%02x", target_signal_to_gdb(sig));
1511         put_packet(s, buf);
1512     }
1513     /* put_packet() might have detected that the peer terminated the
1514        connection.  */
1515     if (s->fd < 0) {
1516         return sig;
1517     }
1518
1519     sig = 0;
1520     s->state = RS_IDLE;
1521     s->running_state = 0;
1522     while (s->running_state == 0) {
1523         n = read(s->fd, buf, 256);
1524         if (n > 0) {
1525             int i;
1526
1527             for (i = 0; i < n; i++) {
1528                 gdb_read_byte(s, buf[i]);
1529             }
1530         } else if (n == 0 || errno != EAGAIN) {
1531             /* XXX: Connection closed.  Should probably wait for another
1532                connection before continuing.  */
1533             return sig;
1534         }
1535     }
1536     sig = s->signal;
1537     s->signal = 0;
1538     return sig;
1539 }
1540
1541 /* Tell the remote gdb that the process has exited due to SIG.  */
1542 void gdb_signalled(CPUArchState *env, int sig)
1543 {
1544     GDBState *s;
1545     char buf[4];
1546
1547     s = gdbserver_state;
1548     if (gdbserver_fd < 0 || s->fd < 0) {
1549         return;
1550     }
1551
1552     snprintf(buf, sizeof(buf), "X%02x", target_signal_to_gdb(sig));
1553     put_packet(s, buf);
1554 }
1555
1556 static void gdb_accept(void)
1557 {
1558     GDBState *s;
1559     struct sockaddr_in sockaddr;
1560     socklen_t len;
1561     int fd;
1562
1563     for(;;) {
1564         len = sizeof(sockaddr);
1565         fd = accept(gdbserver_fd, (struct sockaddr *)&sockaddr, &len);
1566         if (fd < 0 && errno != EINTR) {
1567             perror("accept");
1568             return;
1569         } else if (fd >= 0) {
1570 #ifndef _WIN32
1571             fcntl(fd, F_SETFD, FD_CLOEXEC);
1572 #endif
1573             break;
1574         }
1575     }
1576
1577     /* set short latency */
1578     socket_set_nodelay(fd);
1579
1580     s = g_malloc0(sizeof(GDBState));
1581     s->c_cpu = first_cpu;
1582     s->g_cpu = first_cpu;
1583     s->fd = fd;
1584     gdb_has_xml = false;
1585
1586     gdbserver_state = s;
1587
1588     fcntl(fd, F_SETFL, O_NONBLOCK);
1589 }
1590
1591 static int gdbserver_open(int port)
1592 {
1593     struct sockaddr_in sockaddr;
1594     int fd, ret;
1595
1596     fd = socket(PF_INET, SOCK_STREAM, 0);
1597     if (fd < 0) {
1598         perror("socket");
1599         return -1;
1600     }
1601 #ifndef _WIN32
1602     fcntl(fd, F_SETFD, FD_CLOEXEC);
1603 #endif
1604
1605     socket_set_fast_reuse(fd);
1606
1607     sockaddr.sin_family = AF_INET;
1608     sockaddr.sin_port = htons(port);
1609     sockaddr.sin_addr.s_addr = 0;
1610     ret = bind(fd, (struct sockaddr *)&sockaddr, sizeof(sockaddr));
1611     if (ret < 0) {
1612         perror("bind");
1613         close(fd);
1614         return -1;
1615     }
1616     ret = listen(fd, 0);
1617     if (ret < 0) {
1618         perror("listen");
1619         close(fd);
1620         return -1;
1621     }
1622     return fd;
1623 }
1624
1625 int gdbserver_start(int port)
1626 {
1627     gdbserver_fd = gdbserver_open(port);
1628     if (gdbserver_fd < 0)
1629         return -1;
1630     /* accept connections */
1631     gdb_accept();
1632     return 0;
1633 }
1634
1635 /* Disable gdb stub for child processes.  */
1636 void gdbserver_fork(CPUState *cpu)
1637 {
1638     GDBState *s = gdbserver_state;
1639
1640     if (gdbserver_fd < 0 || s->fd < 0) {
1641         return;
1642     }
1643     close(s->fd);
1644     s->fd = -1;
1645     cpu_breakpoint_remove_all(cpu, BP_GDB);
1646     cpu_watchpoint_remove_all(cpu, BP_GDB);
1647 }
1648 #else
1649 static int gdb_chr_can_receive(void *opaque)
1650 {
1651   /* We can handle an arbitrarily large amount of data.
1652    Pick the maximum packet size, which is as good as anything.  */
1653   return MAX_PACKET_LENGTH;
1654 }
1655
1656 static void gdb_chr_receive(void *opaque, const uint8_t *buf, int size)
1657 {
1658     int i;
1659
1660     for (i = 0; i < size; i++) {
1661         gdb_read_byte(gdbserver_state, buf[i]);
1662     }
1663 }
1664
1665 static void gdb_chr_event(void *opaque, int event)
1666 {
1667     switch (event) {
1668     case CHR_EVENT_OPENED:
1669         vm_stop(RUN_STATE_PAUSED);
1670         gdb_has_xml = false;
1671         break;
1672     default:
1673         break;
1674     }
1675 }
1676
1677 static void gdb_monitor_output(GDBState *s, const char *msg, int len)
1678 {
1679     char buf[MAX_PACKET_LENGTH];
1680
1681     buf[0] = 'O';
1682     if (len > (MAX_PACKET_LENGTH/2) - 1)
1683         len = (MAX_PACKET_LENGTH/2) - 1;
1684     memtohex(buf + 1, (uint8_t *)msg, len);
1685     put_packet(s, buf);
1686 }
1687
1688 static int gdb_monitor_write(CharDriverState *chr, const uint8_t *buf, int len)
1689 {
1690     const char *p = (const char *)buf;
1691     int max_sz;
1692
1693     max_sz = (sizeof(gdbserver_state->last_packet) - 2) / 2;
1694     for (;;) {
1695         if (len <= max_sz) {
1696             gdb_monitor_output(gdbserver_state, p, len);
1697             break;
1698         }
1699         gdb_monitor_output(gdbserver_state, p, max_sz);
1700         p += max_sz;
1701         len -= max_sz;
1702     }
1703     return len;
1704 }
1705
1706 #ifndef _WIN32
1707 static void gdb_sigterm_handler(int signal)
1708 {
1709     if (runstate_is_running()) {
1710         vm_stop(RUN_STATE_PAUSED);
1711     }
1712 }
1713 #endif
1714
1715 int gdbserver_start(const char *device)
1716 {
1717     GDBState *s;
1718     char gdbstub_device_name[128];
1719     CharDriverState *chr = NULL;
1720     CharDriverState *mon_chr;
1721
1722     if (!device)
1723         return -1;
1724     if (strcmp(device, "none") != 0) {
1725         if (strstart(device, "tcp:", NULL)) {
1726             /* enforce required TCP attributes */
1727             snprintf(gdbstub_device_name, sizeof(gdbstub_device_name),
1728                      "%s,nowait,nodelay,server", device);
1729             device = gdbstub_device_name;
1730         }
1731 #ifndef _WIN32
1732         else if (strcmp(device, "stdio") == 0) {
1733             struct sigaction act;
1734
1735             memset(&act, 0, sizeof(act));
1736             act.sa_handler = gdb_sigterm_handler;
1737             sigaction(SIGINT, &act, NULL);
1738         }
1739 #endif
1740         chr = qemu_chr_new("gdb", device, NULL);
1741         if (!chr)
1742             return -1;
1743
1744         qemu_chr_fe_claim_no_fail(chr);
1745         qemu_chr_add_handlers(chr, gdb_chr_can_receive, gdb_chr_receive,
1746                               gdb_chr_event, NULL);
1747     }
1748
1749     s = gdbserver_state;
1750     if (!s) {
1751         s = g_malloc0(sizeof(GDBState));
1752         gdbserver_state = s;
1753
1754         qemu_add_vm_change_state_handler(gdb_vm_state_change, NULL);
1755
1756         /* Initialize a monitor terminal for gdb */
1757         mon_chr = qemu_chr_alloc();
1758         mon_chr->chr_write = gdb_monitor_write;
1759         monitor_init(mon_chr, 0);
1760     } else {
1761         if (s->chr)
1762             qemu_chr_delete(s->chr);
1763         mon_chr = s->mon_chr;
1764         memset(s, 0, sizeof(GDBState));
1765     }
1766     s->c_cpu = first_cpu;
1767     s->g_cpu = first_cpu;
1768     s->chr = chr;
1769     s->state = chr ? RS_IDLE : RS_INACTIVE;
1770     s->mon_chr = mon_chr;
1771     s->current_syscall_cb = NULL;
1772
1773     return 0;
1774 }
1775 #endif