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
  44 #ifdef CONFIG_USER_ONLY
  45 #define GDB_ATTACHED "0"
  46 #else
  47 #define GDB_ATTACHED "1"
  48 #endif
  49
  50 static inline int target_memory_rw_debug(CPUState *cpu, target_ulong addr,
  51                                          uint8_t *buf, int len, bool is_write)
  52 {
  53     CPUClass *cc = CPU_GET_CLASS(cpu);
  54
  55     if (cc->memory_rw_debug) {
  56         return cc->memory_rw_debug(cpu, addr, buf, len, is_write);
  57     }
  58     return cpu_memory_rw_debug(cpu, addr, buf, len, is_write);
  59 }
  60
  61 enum {
  62     GDB_SIGNAL_0 = 0,
  63     GDB_SIGNAL_INT = 2,
  64     GDB_SIGNAL_QUIT = 3,
  65     GDB_SIGNAL_TRAP = 5,
  66     GDB_SIGNAL_ABRT = 6,
  67     GDB_SIGNAL_ALRM = 14,
  68     GDB_SIGNAL_IO = 23,
  69     GDB_SIGNAL_XCPU = 24,
  70     GDB_SIGNAL_UNKNOWN = 143
  71 };
  72
  73 #ifdef CONFIG_USER_ONLY
  74
  75 /* Map target signal numbers to GDB protocol signal numbers and vice
  76  * versa.  For user emulation's currently supported systems, we can
  77  * assume most signals are defined.
  78  */
  79
  80 static int gdb_signal_table[] = {
  81     0,
  82     TARGET_SIGHUP,
  83     TARGET_SIGINT,
  84     TARGET_SIGQUIT,
  85     TARGET_SIGILL,
  86     TARGET_SIGTRAP,
  87     TARGET_SIGABRT,
  88     -1, /* SIGEMT */
  89     TARGET_SIGFPE,
  90     TARGET_SIGKILL,
  91     TARGET_SIGBUS,
  92     TARGET_SIGSEGV,
  93     TARGET_SIGSYS,
  94     TARGET_SIGPIPE,
  95     TARGET_SIGALRM,
  96     TARGET_SIGTERM,
  97     TARGET_SIGURG,
  98     TARGET_SIGSTOP,
  99     TARGET_SIGTSTP,
 100     TARGET_SIGCONT,
 101     TARGET_SIGCHLD,
 102     TARGET_SIGTTIN,
 103     TARGET_SIGTTOU,
 104     TARGET_SIGIO,
 105     TARGET_SIGXCPU,
 106     TARGET_SIGXFSZ,
 107     TARGET_SIGVTALRM,
 108     TARGET_SIGPROF,
 109     TARGET_SIGWINCH,
 110     -1, /* SIGLOST */
 111     TARGET_SIGUSR1,
 112     TARGET_SIGUSR2,
 113 #ifdef TARGET_SIGPWR
 114     TARGET_SIGPWR,
 115 #else
 116     -1,
 117 #endif
 118     -1, /* SIGPOLL */
 119     -1,
 120     -1,
 121     -1,
 122     -1,
 123     -1,
 124     -1,
 125     -1,
 126     -1,
 127     -1,
 128     -1,
 129     -1,
 130 #ifdef __SIGRTMIN
 131     __SIGRTMIN + 1,
 132     __SIGRTMIN + 2,
 133     __SIGRTMIN + 3,
 134     __SIGRTMIN + 4,
 135     __SIGRTMIN + 5,
 136     __SIGRTMIN + 6,
 137     __SIGRTMIN + 7,
 138     __SIGRTMIN + 8,
 139     __SIGRTMIN + 9,
 140     __SIGRTMIN + 10,
 141     __SIGRTMIN + 11,
 142     __SIGRTMIN + 12,
 143     __SIGRTMIN + 13,
 144     __SIGRTMIN + 14,
 145     __SIGRTMIN + 15,
 146     __SIGRTMIN + 16,
 147     __SIGRTMIN + 17,
 148     __SIGRTMIN + 18,
 149     __SIGRTMIN + 19,
 150     __SIGRTMIN + 20,
 151     __SIGRTMIN + 21,
 152     __SIGRTMIN + 22,
 153     __SIGRTMIN + 23,
 154     __SIGRTMIN + 24,
 155     __SIGRTMIN + 25,
 156     __SIGRTMIN + 26,
 157     __SIGRTMIN + 27,
 158     __SIGRTMIN + 28,
 159     __SIGRTMIN + 29,
 160     __SIGRTMIN + 30,
 161     __SIGRTMIN + 31,
 162     -1, /* SIGCANCEL */
 163     __SIGRTMIN,
 164     __SIGRTMIN + 32,
 165     __SIGRTMIN + 33,
 166     __SIGRTMIN + 34,
 167     __SIGRTMIN + 35,
 168     __SIGRTMIN + 36,
 169     __SIGRTMIN + 37,
 170     __SIGRTMIN + 38,
 171     __SIGRTMIN + 39,
 172     __SIGRTMIN + 40,
 173     __SIGRTMIN + 41,
 174     __SIGRTMIN + 42,
 175     __SIGRTMIN + 43,
 176     __SIGRTMIN + 44,
 177     __SIGRTMIN + 45,
 178     __SIGRTMIN + 46,
 179     __SIGRTMIN + 47,
 180     __SIGRTMIN + 48,
 181     __SIGRTMIN + 49,
 182     __SIGRTMIN + 50,
 183     __SIGRTMIN + 51,
 184     __SIGRTMIN + 52,
 185     __SIGRTMIN + 53,
 186     __SIGRTMIN + 54,
 187     __SIGRTMIN + 55,
 188     __SIGRTMIN + 56,
 189     __SIGRTMIN + 57,
 190     __SIGRTMIN + 58,
 191     __SIGRTMIN + 59,
 192     __SIGRTMIN + 60,
 193     __SIGRTMIN + 61,
 194     __SIGRTMIN + 62,
 195     __SIGRTMIN + 63,
 196     __SIGRTMIN + 64,
 197     __SIGRTMIN + 65,
 198     __SIGRTMIN + 66,
 199     __SIGRTMIN + 67,
 200     __SIGRTMIN + 68,
 201     __SIGRTMIN + 69,
 202     __SIGRTMIN + 70,
 203     __SIGRTMIN + 71,
 204     __SIGRTMIN + 72,
 205     __SIGRTMIN + 73,
 206     __SIGRTMIN + 74,
 207     __SIGRTMIN + 75,
 208     __SIGRTMIN + 76,
 209     __SIGRTMIN + 77,
 210     __SIGRTMIN + 78,
 211     __SIGRTMIN + 79,
 212     __SIGRTMIN + 80,
 213     __SIGRTMIN + 81,
 214     __SIGRTMIN + 82,
 215     __SIGRTMIN + 83,
 216     __SIGRTMIN + 84,
 217     __SIGRTMIN + 85,
 218     __SIGRTMIN + 86,
 219     __SIGRTMIN + 87,
 220     __SIGRTMIN + 88,
 221     __SIGRTMIN + 89,
 222     __SIGRTMIN + 90,
 223     __SIGRTMIN + 91,
 224     __SIGRTMIN + 92,
 225     __SIGRTMIN + 93,
 226     __SIGRTMIN + 94,
 227     __SIGRTMIN + 95,
 228     -1, /* SIGINFO */
 229     -1, /* UNKNOWN */
 230     -1, /* DEFAULT */
 231     -1,
 232     -1,
 233     -1,
 234     -1,
 235     -1,
 236     -1
 237 #endif
 238 };
 239 #else
 240 /* In system mode we only need SIGINT and SIGTRAP; other signals
 241    are not yet supported.  */
 242
 243 enum {
 244     TARGET_SIGINT = 2,
 245     TARGET_SIGTRAP = 5
 246 };
 247
 248 static int gdb_signal_table[] = {
 249     -1,
 250     -1,
 251     TARGET_SIGINT,
 252     -1,
 253     -1,
 254     TARGET_SIGTRAP
 255 };
 256 #endif
 257
 258 #ifdef CONFIG_USER_ONLY
 259 static int target_signal_to_gdb (int sig)
 260 {
 261     int i;
 262     for (i = 0; i < ARRAY_SIZE (gdb_signal_table); i++)
 263         if (gdb_signal_table[i] == sig)
 264             return i;
 265     return GDB_SIGNAL_UNKNOWN;
 266 }
 267 #endif
 268
 269 static int gdb_signal_to_target (int sig)
 270 {
 271     if (sig < ARRAY_SIZE (gdb_signal_table))
 272         return gdb_signal_table[sig];
 273     else
 274         return -1;
 275 }
 276
 277 //#define DEBUG_GDB
 278
 279 typedef struct GDBRegisterState {
 280     int base_reg;
 281     int num_regs;
 282     gdb_reg_cb get_reg;
 283     gdb_reg_cb set_reg;
 284     const char *xml;
 285     struct GDBRegisterState *next;
 286 } GDBRegisterState;
 287
 288 enum RSState {
 289     RS_INACTIVE,
 290     RS_IDLE,
 291     RS_GETLINE,
 292     RS_CHKSUM1,
 293     RS_CHKSUM2,
 294 };
 295 typedef struct GDBState {
 296     CPUState *c_cpu; /* current CPU for step/continue ops */
 297     CPUState *g_cpu; /* current CPU for other ops */
 298     CPUState *query_cpu; /* for q{f|s}ThreadInfo */
 299     enum RSState state; /* parsing state */
 300     char line_buf[MAX_PACKET_LENGTH];
 301     int line_buf_index;
 302     int line_csum;
 303     uint8_t last_packet[MAX_PACKET_LENGTH + 4];
 304     int last_packet_len;
 305     int signal;
 306 #ifdef CONFIG_USER_ONLY
 307     int fd;
 308     int running_state;
 309 #else
 310     CharDriverState *chr;
 311     CharDriverState *mon_chr;
 312 #endif
 313     char syscall_buf[256];
 314     gdb_syscall_complete_cb current_syscall_cb;
 315 } GDBState;
 316
 317 /* By default use no IRQs and no timers while single stepping so as to
 318  * make single stepping like an ICE HW step.
 319  */
 320 static int sstep_flags = SSTEP_ENABLE|SSTEP_NOIRQ|SSTEP_NOTIMER;
 321
 322 static GDBState *gdbserver_state;
 323
 324 bool gdb_has_xml;
 325
 326 int semihosting_target = SEMIHOSTING_TARGET_AUTO;
 327
 328 #ifdef CONFIG_USER_ONLY
 329 /* XXX: This is not thread safe.  Do we care?  */
 330 static int gdbserver_fd = -1;
 331
 332 static int get_char(GDBState *s)
 333 {
 334     uint8_t ch;
 335     int ret;
 336
 337     for(;;) {
 338         ret = qemu_recv(s->fd, &ch, 1, 0);
 339         if (ret < 0) {
 340             if (errno == ECONNRESET)
 341                 s->fd = -1;
 342             if (errno != EINTR && errno != EAGAIN)
 343                 return -1;
 344         } else if (ret == 0) {
 345             close(s->fd);
 346             s->fd = -1;
 347             return -1;
 348         } else {
 349             break;
 350         }
 351     }
 352     return ch;
 353 }
 354 #endif
 355
 356 static enum {
 357     GDB_SYS_UNKNOWN,
 358     GDB_SYS_ENABLED,
 359     GDB_SYS_DISABLED,
 360 } gdb_syscall_mode;
 361
 362 /* Decide if either remote gdb syscalls or native file IO should be used. */
 363 int use_gdb_syscalls(void)
 364 {
 365     if (semihosting_target == SEMIHOSTING_TARGET_NATIVE) {
 366         /* -semihosting-config target=native */
 367         return false;
 368     } else if (semihosting_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     CPUClass *cc = CPU_GET_CLASS(cpu);
 758
 759     cpu_synchronize_state(cpu);
 760     if (cc->set_pc) {
 761         cc->set_pc(cpu, pc);
 762     }
 763 }
 764
 765 static CPUState *find_cpu(uint32_t thread_id)
 766 {
 767     CPUState *cpu;
 768
 769     CPU_FOREACH(cpu) {
 770         if (cpu_index(cpu) == thread_id) {
 771             return cpu;
 772         }
 773     }
 774
 775     return NULL;
 776 }
 777
 778 static int is_query_packet(const char *p, const char *query, char separator)
 779 {
 780     unsigned int query_len = strlen(query);
 781
 782     return strncmp(p, query, query_len) == 0 &&
 783         (p[query_len] == '\0' || p[query_len] == separator);
 784 }
 785
 786 static int gdb_handle_packet(GDBState *s, const char *line_buf)
 787 {
 788     CPUState *cpu;
 789     CPUClass *cc;
 790     const char *p;
 791     uint32_t thread;
 792     int ch, reg_size, type, res;
 793     char buf[MAX_PACKET_LENGTH];
 794     uint8_t mem_buf[MAX_PACKET_LENGTH];
 795     uint8_t *registers;
 796     target_ulong addr, len;
 797
 798 #ifdef DEBUG_GDB
 799     printf("command='%s'\n", line_buf);
 800 #endif
 801     p = line_buf;
 802     ch = *p++;
 803     switch(ch) {
 804     case '?':
 805         /* TODO: Make this return the correct value for user-mode.  */
 806         snprintf(buf, sizeof(buf), "T%02xthread:%02x;", GDB_SIGNAL_TRAP,
 807                  cpu_index(s->c_cpu));
 808         put_packet(s, buf);
 809         /* Remove all the breakpoints when this query is issued,
 810          * because gdb is doing and initial connect and the state
 811          * should be cleaned up.
 812          */
 813         gdb_breakpoint_remove_all();
 814         break;
 815     case 'c':
 816         if (*p != '\0') {
 817             addr = strtoull(p, (char **)&p, 16);
 818             gdb_set_cpu_pc(s, addr);
 819         }
 820         s->signal = 0;
 821         gdb_continue(s);
 822         return RS_IDLE;
 823     case 'C':
 824         s->signal = gdb_signal_to_target (strtoul(p, (char **)&p, 16));
 825         if (s->signal == -1)
 826             s->signal = 0;
 827         gdb_continue(s);
 828         return RS_IDLE;
 829     case 'v':
 830         if (strncmp(p, "Cont", 4) == 0) {
 831             int res_signal, res_thread;
 832
 833             p += 4;
 834             if (*p == '?') {
 835                 put_packet(s, "vCont;c;C;s;S");
 836                 break;
 837             }
 838             res = 0;
 839             res_signal = 0;
 840             res_thread = 0;
 841             while (*p) {
 842                 int action, signal;
 843
 844                 if (*p++ != ';') {
 845                     res = 0;
 846                     break;
 847                 }
 848                 action = *p++;
 849                 signal = 0;
 850                 if (action == 'C' || action == 'S') {
 851                     signal = gdb_signal_to_target(strtoul(p, (char **)&p, 16));
 852                     if (signal == -1) {
 853                         signal = 0;
 854                     }
 855                 } else if (action != 'c' && action != 's') {
 856                     res = 0;
 857                     break;
 858                 }
 859                 thread = 0;
 860                 if (*p == ':') {
 861                     thread = strtoull(p+1, (char **)&p, 16);
 862                 }
 863                 action = tolower(action);
 864                 if (res == 0 || (res == 'c' && action == 's')) {
 865                     res = action;
 866                     res_signal = signal;
 867                     res_thread = thread;
 868                 }
 869             }
 870             if (res) {
 871                 if (res_thread != -1 && res_thread != 0) {
 872                     cpu = find_cpu(res_thread);
 873                     if (cpu == NULL) {
 874                         put_packet(s, "E22");
 875                         break;
 876                     }
 877                     s->c_cpu = cpu;
 878                 }
 879                 if (res == 's') {
 880                     cpu_single_step(s->c_cpu, sstep_flags);
 881                 }
 882                 s->signal = res_signal;
 883                 gdb_continue(s);
 884                 return RS_IDLE;
 885             }
 886             break;
 887         } else {
 888             goto unknown_command;
 889         }
 890     case 'k':
 891         /* Kill the target */
 892         fprintf(stderr, "\nQEMU: Terminated via GDBstub\n");
 893         exit(0);
 894     case 'D':
 895         /* Detach packet */
 896         gdb_breakpoint_remove_all();
 897         gdb_syscall_mode = GDB_SYS_DISABLED;
 898         gdb_continue(s);
 899         put_packet(s, "OK");
 900         break;
 901     case 's':
 902         if (*p != '\0') {
 903             addr = strtoull(p, (char **)&p, 16);
 904             gdb_set_cpu_pc(s, addr);
 905         }
 906         cpu_single_step(s->c_cpu, sstep_flags);
 907         gdb_continue(s);
 908         return RS_IDLE;
 909     case 'F':
 910         {
 911             target_ulong ret;
 912             target_ulong err;
 913
 914             ret = strtoull(p, (char **)&p, 16);
 915             if (*p == ',') {
 916                 p++;
 917                 err = strtoull(p, (char **)&p, 16);
 918             } else {
 919                 err = 0;
 920             }
 921             if (*p == ',')
 922                 p++;
 923             type = *p;
 924             if (s->current_syscall_cb) {
 925                 s->current_syscall_cb(s->c_cpu, ret, err);
 926                 s->current_syscall_cb = NULL;
 927             }
 928             if (type == 'C') {
 929                 put_packet(s, "T02");
 930             } else {
 931                 gdb_continue(s);
 932             }
 933         }
 934         break;
 935     case 'g':
 936         cpu_synchronize_state(s->g_cpu);
 937         len = 0;
 938         for (addr = 0; addr < s->g_cpu->gdb_num_g_regs; addr++) {
 939             reg_size = gdb_read_register(s->g_cpu, mem_buf + len, addr);
 940             len += reg_size;
 941         }
 942         memtohex(buf, mem_buf, len);
 943         put_packet(s, buf);
 944         break;
 945     case 'G':
 946         cpu_synchronize_state(s->g_cpu);
 947         registers = mem_buf;
 948         len = strlen(p) / 2;
 949         hextomem((uint8_t *)registers, p, len);
 950         for (addr = 0; addr < s->g_cpu->gdb_num_g_regs && len > 0; addr++) {
 951             reg_size = gdb_write_register(s->g_cpu, registers, addr);
 952             len -= reg_size;
 953             registers += reg_size;
 954         }
 955         put_packet(s, "OK");
 956         break;
 957     case 'm':
 958         addr = strtoull(p, (char **)&p, 16);
 959         if (*p == ',')
 960             p++;
 961         len = strtoull(p, NULL, 16);
 962         if (target_memory_rw_debug(s->g_cpu, addr, mem_buf, len, false) != 0) {
 963             put_packet (s, "E14");
 964         } else {
 965             memtohex(buf, mem_buf, len);
 966             put_packet(s, buf);
 967         }
 968         break;
 969     case 'M':
 970         addr = strtoull(p, (char **)&p, 16);
 971         if (*p == ',')
 972             p++;
 973         len = strtoull(p, (char **)&p, 16);
 974         if (*p == ':')
 975             p++;
 976         hextomem(mem_buf, p, len);
 977         if (target_memory_rw_debug(s->g_cpu, addr, mem_buf, len,
 978                                    true) != 0) {
 979             put_packet(s, "E14");
 980         } else {
 981             put_packet(s, "OK");
 982         }
 983         break;
 984     case 'p':
 985         /* Older gdb are really dumb, and don't use 'g' if 'p' is avaialable.
 986            This works, but can be very slow.  Anything new enough to
 987            understand XML also knows how to use this properly.  */
 988         if (!gdb_has_xml)
 989             goto unknown_command;
 990         addr = strtoull(p, (char **)&p, 16);
 991         reg_size = gdb_read_register(s->g_cpu, mem_buf, addr);
 992         if (reg_size) {
 993             memtohex(buf, mem_buf, reg_size);
 994             put_packet(s, buf);
 995         } else {
 996             put_packet(s, "E14");
 997         }
 998         break;
 999     case 'P':
1000         if (!gdb_has_xml)
1001             goto unknown_command;
1002         addr = strtoull(p, (char **)&p, 16);
1003         if (*p == '=')
1004             p++;
1005         reg_size = strlen(p) / 2;
1006         hextomem(mem_buf, p, reg_size);
1007         gdb_write_register(s->g_cpu, mem_buf, addr);
1008         put_packet(s, "OK");
1009         break;
1010     case 'Z':
1011     case 'z':
1012         type = strtoul(p, (char **)&p, 16);
1013         if (*p == ',')
1014             p++;
1015         addr = strtoull(p, (char **)&p, 16);
1016         if (*p == ',')
1017             p++;
1018         len = strtoull(p, (char **)&p, 16);
1019         if (ch == 'Z')
1020             res = gdb_breakpoint_insert(addr, len, type);
1021         else
1022             res = gdb_breakpoint_remove(addr, len, type);
1023         if (res >= 0)
1024              put_packet(s, "OK");
1025         else if (res == -ENOSYS)
1026             put_packet(s, "");
1027         else
1028             put_packet(s, "E22");
1029         break;
1030     case 'H':
1031         type = *p++;
1032         thread = strtoull(p, (char **)&p, 16);
1033         if (thread == -1 || thread == 0) {
1034             put_packet(s, "OK");
1035             break;
1036         }
1037         cpu = find_cpu(thread);
1038         if (cpu == NULL) {
1039             put_packet(s, "E22");
1040             break;
1041         }
1042         switch (type) {
1043         case 'c':
1044             s->c_cpu = cpu;
1045             put_packet(s, "OK");
1046             break;
1047         case 'g':
1048             s->g_cpu = cpu;
1049             put_packet(s, "OK");
1050             break;
1051         default:
1052              put_packet(s, "E22");
1053              break;
1054         }
1055         break;
1056     case 'T':
1057         thread = strtoull(p, (char **)&p, 16);
1058         cpu = find_cpu(thread);
1059
1060         if (cpu != NULL) {
1061             put_packet(s, "OK");
1062         } else {
1063             put_packet(s, "E22");
1064         }
1065         break;
1066     case 'q':
1067     case 'Q':
1068         /* parse any 'q' packets here */
1069         if (!strcmp(p,"qemu.sstepbits")) {
1070             /* Query Breakpoint bit definitions */
1071             snprintf(buf, sizeof(buf), "ENABLE=%x,NOIRQ=%x,NOTIMER=%x",
1072                      SSTEP_ENABLE,
1073                      SSTEP_NOIRQ,
1074                      SSTEP_NOTIMER);
1075             put_packet(s, buf);
1076             break;
1077         } else if (is_query_packet(p, "qemu.sstep", '=')) {
1078             /* Display or change the sstep_flags */
1079             p += 10;
1080             if (*p != '=') {
1081                 /* Display current setting */
1082                 snprintf(buf, sizeof(buf), "0x%x", sstep_flags);
1083                 put_packet(s, buf);
1084                 break;
1085             }
1086             p++;
1087             type = strtoul(p, (char **)&p, 16);
1088             sstep_flags = type;
1089             put_packet(s, "OK");
1090             break;
1091         } else if (strcmp(p,"C") == 0) {
1092             /* "Current thread" remains vague in the spec, so always return
1093              *  the first CPU (gdb returns the first thread). */
1094             put_packet(s, "QC1");
1095             break;
1096         } else if (strcmp(p,"fThreadInfo") == 0) {
1097             s->query_cpu = first_cpu;
1098             goto report_cpuinfo;
1099         } else if (strcmp(p,"sThreadInfo") == 0) {
1100         report_cpuinfo:
1101             if (s->query_cpu) {
1102                 snprintf(buf, sizeof(buf), "m%x", cpu_index(s->query_cpu));
1103                 put_packet(s, buf);
1104                 s->query_cpu = CPU_NEXT(s->query_cpu);
1105             } else
1106                 put_packet(s, "l");
1107             break;
1108         } else if (strncmp(p,"ThreadExtraInfo,", 16) == 0) {
1109             thread = strtoull(p+16, (char **)&p, 16);
1110             cpu = find_cpu(thread);
1111             if (cpu != NULL) {
1112                 cpu_synchronize_state(cpu);
1113                 len = snprintf((char *)mem_buf, sizeof(mem_buf),
1114                                "CPU#%d [%s]", cpu->cpu_index,
1115                                cpu->halted ? "halted " : "running");
1116                 memtohex(buf, mem_buf, len);
1117                 put_packet(s, buf);
1118             }
1119             break;
1120         }
1121 #ifdef CONFIG_USER_ONLY
1122         else if (strcmp(p, "Offsets") == 0) {
1123             TaskState *ts = s->c_cpu->opaque;
1124
1125             snprintf(buf, sizeof(buf),
1126                      "Text=" TARGET_ABI_FMT_lx ";Data=" TARGET_ABI_FMT_lx
1127                      ";Bss=" TARGET_ABI_FMT_lx,
1128                      ts->info->code_offset,
1129                      ts->info->data_offset,
1130                      ts->info->data_offset);
1131             put_packet(s, buf);
1132             break;
1133         }
1134 #else /* !CONFIG_USER_ONLY */
1135         else if (strncmp(p, "Rcmd,", 5) == 0) {
1136             int len = strlen(p + 5);
1137
1138             if ((len % 2) != 0) {
1139                 put_packet(s, "E01");
1140                 break;
1141             }
1142             hextomem(mem_buf, p + 5, len);
1143             len = len / 2;
1144             mem_buf[len++] = 0;
1145             qemu_chr_be_write(s->mon_chr, mem_buf, len);
1146             put_packet(s, "OK");
1147             break;
1148         }
1149 #endif /* !CONFIG_USER_ONLY */
1150         if (is_query_packet(p, "Supported", ':')) {
1151             snprintf(buf, sizeof(buf), "PacketSize=%x", MAX_PACKET_LENGTH);
1152             cc = CPU_GET_CLASS(first_cpu);
1153             if (cc->gdb_core_xml_file != NULL) {
1154                 pstrcat(buf, sizeof(buf), ";qXfer:features:read+");
1155             }
1156             put_packet(s, buf);
1157             break;
1158         }
1159         if (strncmp(p, "Xfer:features:read:", 19) == 0) {
1160             const char *xml;
1161             target_ulong total_len;
1162
1163             cc = CPU_GET_CLASS(first_cpu);
1164             if (cc->gdb_core_xml_file == NULL) {
1165                 goto unknown_command;
1166             }
1167
1168             gdb_has_xml = true;
1169             p += 19;
1170             xml = get_feature_xml(p, &p, cc);
1171             if (!xml) {
1172                 snprintf(buf, sizeof(buf), "E00");
1173                 put_packet(s, buf);
1174                 break;
1175             }
1176
1177             if (*p == ':')
1178                 p++;
1179             addr = strtoul(p, (char **)&p, 16);
1180             if (*p == ',')
1181                 p++;
1182             len = strtoul(p, (char **)&p, 16);
1183
1184             total_len = strlen(xml);
1185             if (addr > total_len) {
1186                 snprintf(buf, sizeof(buf), "E00");
1187                 put_packet(s, buf);
1188                 break;
1189             }
1190             if (len > (MAX_PACKET_LENGTH - 5) / 2)
1191                 len = (MAX_PACKET_LENGTH - 5) / 2;
1192             if (len < total_len - addr) {
1193                 buf[0] = 'm';
1194                 len = memtox(buf + 1, xml + addr, len);
1195             } else {
1196                 buf[0] = 'l';
1197                 len = memtox(buf + 1, xml + addr, total_len - addr);
1198             }
1199             put_packet_binary(s, buf, len + 1);
1200             break;
1201         }
1202         if (is_query_packet(p, "Attached", ':')) {
1203             put_packet(s, GDB_ATTACHED);
1204             break;
1205         }
1206         /* Unrecognised 'q' command.  */
1207         goto unknown_command;
1208
1209     default:
1210     unknown_command:
1211         /* put empty packet */
1212         buf[0] = '\0';
1213         put_packet(s, buf);
1214         break;
1215     }
1216     return RS_IDLE;
1217 }
1218
1219 void gdb_set_stop_cpu(CPUState *cpu)
1220 {
1221     gdbserver_state->c_cpu = cpu;
1222     gdbserver_state->g_cpu = cpu;
1223 }
1224
1225 #ifndef CONFIG_USER_ONLY
1226 static void gdb_vm_state_change(void *opaque, int running, RunState state)
1227 {
1228     GDBState *s = gdbserver_state;
1229     CPUArchState *env = s->c_cpu->env_ptr;
1230     CPUState *cpu = s->c_cpu;
1231     char buf[256];
1232     const char *type;
1233     int ret;
1234
1235     if (running || s->state == RS_INACTIVE) {
1236         return;
1237     }
1238     /* Is there a GDB syscall waiting to be sent?  */
1239     if (s->current_syscall_cb) {
1240         put_packet(s, s->syscall_buf);
1241         return;
1242     }
1243     switch (state) {
1244     case RUN_STATE_DEBUG:
1245         if (cpu->watchpoint_hit) {
1246             switch (cpu->watchpoint_hit->flags & BP_MEM_ACCESS) {
1247             case BP_MEM_READ:
1248                 type = "r";
1249                 break;
1250             case BP_MEM_ACCESS:
1251                 type = "a";
1252                 break;
1253             default:
1254                 type = "";
1255                 break;
1256             }
1257             snprintf(buf, sizeof(buf),
1258                      "T%02xthread:%02x;%swatch:" TARGET_FMT_lx ";",
1259                      GDB_SIGNAL_TRAP, cpu_index(cpu), type,
1260                      (target_ulong)cpu->watchpoint_hit->vaddr);
1261             cpu->watchpoint_hit = NULL;
1262             goto send_packet;
1263         }
1264         tb_flush(env);
1265         ret = GDB_SIGNAL_TRAP;
1266         break;
1267     case RUN_STATE_PAUSED:
1268         ret = GDB_SIGNAL_INT;
1269         break;
1270     case RUN_STATE_SHUTDOWN:
1271         ret = GDB_SIGNAL_QUIT;
1272         break;
1273     case RUN_STATE_IO_ERROR:
1274         ret = GDB_SIGNAL_IO;
1275         break;
1276     case RUN_STATE_WATCHDOG:
1277         ret = GDB_SIGNAL_ALRM;
1278         break;
1279     case RUN_STATE_INTERNAL_ERROR:
1280         ret = GDB_SIGNAL_ABRT;
1281         break;
1282     case RUN_STATE_SAVE_VM:
1283     case RUN_STATE_RESTORE_VM:
1284         return;
1285     case RUN_STATE_FINISH_MIGRATE:
1286         ret = GDB_SIGNAL_XCPU;
1287         break;
1288     default:
1289         ret = GDB_SIGNAL_UNKNOWN;
1290         break;
1291     }
1292     snprintf(buf, sizeof(buf), "T%02xthread:%02x;", ret, cpu_index(cpu));
1293
1294 send_packet:
1295     put_packet(s, buf);
1296
1297     /* disable single step if it was enabled */
1298     cpu_single_step(cpu, 0);
1299 }
1300 #endif
1301
1302 /* Send a gdb syscall request.
1303    This accepts limited printf-style format specifiers, specifically:
1304     %x  - target_ulong argument printed in hex.
1305     %lx - 64-bit argument printed in hex.
1306     %s  - string pointer (target_ulong) and length (int) pair.  */
1307 void gdb_do_syscall(gdb_syscall_complete_cb cb, const char *fmt, ...)
1308 {
1309     va_list va;
1310     char *p;
1311     char *p_end;
1312     target_ulong addr;
1313     uint64_t i64;
1314     GDBState *s;
1315
1316     s = gdbserver_state;
1317     if (!s)
1318         return;
1319     s->current_syscall_cb = cb;
1320 #ifndef CONFIG_USER_ONLY
1321     vm_stop(RUN_STATE_DEBUG);
1322 #endif
1323     va_start(va, fmt);
1324     p = s->syscall_buf;
1325     p_end = &s->syscall_buf[sizeof(s->syscall_buf)];
1326     *(p++) = 'F';
1327     while (*fmt) {
1328         if (*fmt == '%') {
1329             fmt++;
1330             switch (*fmt++) {
1331             case 'x':
1332                 addr = va_arg(va, target_ulong);
1333                 p += snprintf(p, p_end - p, TARGET_FMT_lx, addr);
1334                 break;
1335             case 'l':
1336                 if (*(fmt++) != 'x')
1337                     goto bad_format;
1338                 i64 = va_arg(va, uint64_t);
1339                 p += snprintf(p, p_end - p, "%" PRIx64, i64);
1340                 break;
1341             case 's':
1342                 addr = va_arg(va, target_ulong);
1343                 p += snprintf(p, p_end - p, TARGET_FMT_lx "/%x",
1344                               addr, va_arg(va, int));
1345                 break;
1346             default:
1347             bad_format:
1348                 fprintf(stderr, "gdbstub: Bad syscall format string '%s'\n",
1349                         fmt - 1);
1350                 break;
1351             }
1352         } else {
1353             *(p++) = *(fmt++);
1354         }
1355     }
1356     *p = 0;
1357     va_end(va);
1358 #ifdef CONFIG_USER_ONLY
1359     put_packet(s, s->syscall_buf);
1360     gdb_handlesig(s->c_cpu, 0);
1361 #else
1362     /* In this case wait to send the syscall packet until notification that
1363        the CPU has stopped.  This must be done because if the packet is sent
1364        now the reply from the syscall request could be received while the CPU
1365        is still in the running state, which can cause packets to be dropped
1366        and state transition 'T' packets to be sent while the syscall is still
1367        being processed.  */
1368     cpu_exit(s->c_cpu);
1369 #endif
1370 }
1371
1372 static void gdb_read_byte(GDBState *s, int ch)
1373 {
1374     int i, csum;
1375     uint8_t reply;
1376
1377 #ifndef CONFIG_USER_ONLY
1378     if (s->last_packet_len) {
1379         /* Waiting for a response to the last packet.  If we see the start
1380            of a new command then abandon the previous response.  */
1381         if (ch == '-') {
1382 #ifdef DEBUG_GDB
1383             printf("Got NACK, retransmitting\n");
1384 #endif
1385             put_buffer(s, (uint8_t *)s->last_packet, s->last_packet_len);
1386         }
1387 #ifdef DEBUG_GDB
1388         else if (ch == '+')
1389             printf("Got ACK\n");
1390         else
1391             printf("Got '%c' when expecting ACK/NACK\n", ch);
1392 #endif
1393         if (ch == '+' || ch == '$')
1394             s->last_packet_len = 0;
1395         if (ch != '$')
1396             return;
1397     }
1398     if (runstate_is_running()) {
1399         /* when the CPU is running, we cannot do anything except stop
1400            it when receiving a char */
1401         vm_stop(RUN_STATE_PAUSED);
1402     } else
1403 #endif
1404     {
1405         switch(s->state) {
1406         case RS_IDLE:
1407             if (ch == '$') {
1408                 s->line_buf_index = 0;
1409                 s->state = RS_GETLINE;
1410             }
1411             break;
1412         case RS_GETLINE:
1413             if (ch == '#') {
1414             s->state = RS_CHKSUM1;
1415             } else if (s->line_buf_index >= sizeof(s->line_buf) - 1) {
1416                 s->state = RS_IDLE;
1417             } else {
1418             s->line_buf[s->line_buf_index++] = ch;
1419             }
1420             break;
1421         case RS_CHKSUM1:
1422             s->line_buf[s->line_buf_index] = '\0';
1423             s->line_csum = fromhex(ch) << 4;
1424             s->state = RS_CHKSUM2;
1425             break;
1426         case RS_CHKSUM2:
1427             s->line_csum |= fromhex(ch);
1428             csum = 0;
1429             for(i = 0; i < s->line_buf_index; i++) {
1430                 csum += s->line_buf[i];
1431             }
1432             if (s->line_csum != (csum & 0xff)) {
1433                 reply = '-';
1434                 put_buffer(s, &reply, 1);
1435                 s->state = RS_IDLE;
1436             } else {
1437                 reply = '+';
1438                 put_buffer(s, &reply, 1);
1439                 s->state = gdb_handle_packet(s, s->line_buf);
1440             }
1441             break;
1442         default:
1443             abort();
1444         }
1445     }
1446 }
1447
1448 /* Tell the remote gdb that the process has exited.  */
1449 void gdb_exit(CPUArchState *env, int code)
1450 {
1451   GDBState *s;
1452   char buf[4];
1453
1454   s = gdbserver_state;
1455   if (!s) {
1456       return;
1457   }
1458 #ifdef CONFIG_USER_ONLY
1459   if (gdbserver_fd < 0 || s->fd < 0) {
1460       return;
1461   }
1462 #else
1463   if (!s->chr) {
1464       return;
1465   }
1466 #endif
1467
1468   snprintf(buf, sizeof(buf), "W%02x", (uint8_t)code);
1469   put_packet(s, buf);
1470
1471 #ifndef CONFIG_USER_ONLY
1472   qemu_chr_delete(s->chr);
1473 #endif
1474 }
1475
1476 #ifdef CONFIG_USER_ONLY
1477 int
1478 gdb_queuesig (void)
1479 {
1480     GDBState *s;
1481
1482     s = gdbserver_state;
1483
1484     if (gdbserver_fd < 0 || s->fd < 0)
1485         return 0;
1486     else
1487         return 1;
1488 }
1489
1490 int
1491 gdb_handlesig(CPUState *cpu, int sig)
1492 {
1493     CPUArchState *env = cpu->env_ptr;
1494     GDBState *s;
1495     char buf[256];
1496     int n;
1497
1498     s = gdbserver_state;
1499     if (gdbserver_fd < 0 || s->fd < 0) {
1500         return sig;
1501     }
1502
1503     /* disable single step if it was enabled */
1504     cpu_single_step(cpu, 0);
1505     tb_flush(env);
1506
1507     if (sig != 0) {
1508         snprintf(buf, sizeof(buf), "S%02x", target_signal_to_gdb(sig));
1509         put_packet(s, buf);
1510     }
1511     /* put_packet() might have detected that the peer terminated the
1512        connection.  */
1513     if (s->fd < 0) {
1514         return sig;
1515     }
1516
1517     sig = 0;
1518     s->state = RS_IDLE;
1519     s->running_state = 0;
1520     while (s->running_state == 0) {
1521         n = read(s->fd, buf, 256);
1522         if (n > 0) {
1523             int i;
1524
1525             for (i = 0; i < n; i++) {
1526                 gdb_read_byte(s, buf[i]);
1527             }
1528         } else if (n == 0 || errno != EAGAIN) {
1529             /* XXX: Connection closed.  Should probably wait for another
1530                connection before continuing.  */
1531             return sig;
1532         }
1533     }
1534     sig = s->signal;
1535     s->signal = 0;
1536     return sig;
1537 }
1538
1539 /* Tell the remote gdb that the process has exited due to SIG.  */
1540 void gdb_signalled(CPUArchState *env, int sig)
1541 {
1542     GDBState *s;
1543     char buf[4];
1544
1545     s = gdbserver_state;
1546     if (gdbserver_fd < 0 || s->fd < 0) {
1547         return;
1548     }
1549
1550     snprintf(buf, sizeof(buf), "X%02x", target_signal_to_gdb(sig));
1551     put_packet(s, buf);
1552 }
1553
1554 static void gdb_accept(void)
1555 {
1556     GDBState *s;
1557     struct sockaddr_in sockaddr;
1558     socklen_t len;
1559     int fd;
1560
1561     for(;;) {
1562         len = sizeof(sockaddr);
1563         fd = accept(gdbserver_fd, (struct sockaddr *)&sockaddr, &len);
1564         if (fd < 0 && errno != EINTR) {
1565             perror("accept");
1566             return;
1567         } else if (fd >= 0) {
1568 #ifndef _WIN32
1569             fcntl(fd, F_SETFD, FD_CLOEXEC);
1570 #endif
1571             break;
1572         }
1573     }
1574
1575     /* set short latency */
1576     socket_set_nodelay(fd);
1577
1578     s = g_malloc0(sizeof(GDBState));
1579     s->c_cpu = first_cpu;
1580     s->g_cpu = first_cpu;
1581     s->fd = fd;
1582     gdb_has_xml = false;
1583
1584     gdbserver_state = s;
1585
1586     fcntl(fd, F_SETFL, O_NONBLOCK);
1587 }
1588
1589 static int gdbserver_open(int port)
1590 {
1591     struct sockaddr_in sockaddr;
1592     int fd, ret;
1593
1594     fd = socket(PF_INET, SOCK_STREAM, 0);
1595     if (fd < 0) {
1596         perror("socket");
1597         return -1;
1598     }
1599 #ifndef _WIN32
1600     fcntl(fd, F_SETFD, FD_CLOEXEC);
1601 #endif
1602
1603     socket_set_fast_reuse(fd);
1604
1605     sockaddr.sin_family = AF_INET;
1606     sockaddr.sin_port = htons(port);
1607     sockaddr.sin_addr.s_addr = 0;
1608     ret = bind(fd, (struct sockaddr *)&sockaddr, sizeof(sockaddr));
1609     if (ret < 0) {
1610         perror("bind");
1611         close(fd);
1612         return -1;
1613     }
1614     ret = listen(fd, 0);
1615     if (ret < 0) {
1616         perror("listen");
1617         close(fd);
1618         return -1;
1619     }
1620     return fd;
1621 }
1622
1623 int gdbserver_start(int port)
1624 {
1625     gdbserver_fd = gdbserver_open(port);
1626     if (gdbserver_fd < 0)
1627         return -1;
1628     /* accept connections */
1629     gdb_accept();
1630     return 0;
1631 }
1632
1633 /* Disable gdb stub for child processes.  */
1634 void gdbserver_fork(CPUArchState *env)
1635 {
1636     CPUState *cpu = ENV_GET_CPU(env);
1637     GDBState *s = gdbserver_state;
1638
1639     if (gdbserver_fd < 0 || s->fd < 0) {
1640         return;
1641     }
1642     close(s->fd);
1643     s->fd = -1;
1644     cpu_breakpoint_remove_all(cpu, BP_GDB);
1645     cpu_watchpoint_remove_all(cpu, BP_GDB);
1646 }
1647 #else
1648 static int gdb_chr_can_receive(void *opaque)
1649 {
1650   /* We can handle an arbitrarily large amount of data.
1651    Pick the maximum packet size, which is as good as anything.  */
1652   return MAX_PACKET_LENGTH;
1653 }
1654
1655 static void gdb_chr_receive(void *opaque, const uint8_t *buf, int size)
1656 {
1657     int i;
1658
1659     for (i = 0; i < size; i++) {
1660         gdb_read_byte(gdbserver_state, buf[i]);
1661     }
1662 }
1663
1664 static void gdb_chr_event(void *opaque, int event)
1665 {
1666     switch (event) {
1667     case CHR_EVENT_OPENED:
1668         vm_stop(RUN_STATE_PAUSED);
1669         gdb_has_xml = false;
1670         break;
1671     default:
1672         break;
1673     }
1674 }
1675
1676 static void gdb_monitor_output(GDBState *s, const char *msg, int len)
1677 {
1678     char buf[MAX_PACKET_LENGTH];
1679
1680     buf[0] = 'O';
1681     if (len > (MAX_PACKET_LENGTH/2) - 1)
1682         len = (MAX_PACKET_LENGTH/2) - 1;
1683     memtohex(buf + 1, (uint8_t *)msg, len);
1684     put_packet(s, buf);
1685 }
1686
1687 static int gdb_monitor_write(CharDriverState *chr, const uint8_t *buf, int len)
1688 {
1689     const char *p = (const char *)buf;
1690     int max_sz;
1691
1692     max_sz = (sizeof(gdbserver_state->last_packet) - 2) / 2;
1693     for (;;) {
1694         if (len <= max_sz) {
1695             gdb_monitor_output(gdbserver_state, p, len);
1696             break;
1697         }
1698         gdb_monitor_output(gdbserver_state, p, max_sz);
1699         p += max_sz;
1700         len -= max_sz;
1701     }
1702     return len;
1703 }
1704
1705 #ifndef _WIN32
1706 static void gdb_sigterm_handler(int signal)
1707 {
1708     if (runstate_is_running()) {
1709         vm_stop(RUN_STATE_PAUSED);
1710     }
1711 }
1712 #endif
1713
1714 int gdbserver_start(const char *device)
1715 {
1716     GDBState *s;
1717     char gdbstub_device_name[128];
1718     CharDriverState *chr = NULL;
1719     CharDriverState *mon_chr;
1720
1721     if (!device)
1722         return -1;
1723     if (strcmp(device, "none") != 0) {
1724         if (strstart(device, "tcp:", NULL)) {
1725             /* enforce required TCP attributes */
1726             snprintf(gdbstub_device_name, sizeof(gdbstub_device_name),
1727                      "%s,nowait,nodelay,server", device);
1728             device = gdbstub_device_name;
1729         }
1730 #ifndef _WIN32
1731         else if (strcmp(device, "stdio") == 0) {
1732             struct sigaction act;
1733
1734             memset(&act, 0, sizeof(act));
1735             act.sa_handler = gdb_sigterm_handler;
1736             sigaction(SIGINT, &act, NULL);
1737         }
1738 #endif
1739         chr = qemu_chr_new("gdb", device, NULL);
1740         if (!chr)
1741             return -1;
1742
1743         qemu_chr_fe_claim_no_fail(chr);
1744         qemu_chr_add_handlers(chr, gdb_chr_can_receive, gdb_chr_receive,
1745                               gdb_chr_event, NULL);
1746     }
1747
1748     s = gdbserver_state;
1749     if (!s) {
1750         s = g_malloc0(sizeof(GDBState));
1751         gdbserver_state = s;
1752
1753         qemu_add_vm_change_state_handler(gdb_vm_state_change, NULL);
1754
1755         /* Initialize a monitor terminal for gdb */
1756         mon_chr = qemu_chr_alloc();
1757         mon_chr->chr_write = gdb_monitor_write;
1758         monitor_init(mon_chr, 0);
1759     } else {
1760         if (s->chr)
1761             qemu_chr_delete(s->chr);
1762         mon_chr = s->mon_chr;
1763         memset(s, 0, sizeof(GDBState));
1764     }
1765     s->c_cpu = first_cpu;
1766     s->g_cpu = first_cpu;
1767     s->chr = chr;
1768     s->state = chr ? RS_IDLE : RS_INACTIVE;
1769     s->mon_chr = mon_chr;
1770     s->current_syscall_cb = NULL;
1771
1772     return 0;
1773 }
1774 #endif