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 "qemu/osdep.h"
  20 #include "qapi/error.h"
  21 #include "qemu/error-report.h"
  22 #include "qemu/cutils.h"
  23 #include "cpu.h"
  24 #ifdef CONFIG_USER_ONLY
  25 #include "qemu.h"
  26 #else
  27 #include "monitor/monitor.h"
  28 #include "sysemu/char.h"
  29 #include "sysemu/sysemu.h"
  30 #include "exec/gdbstub.h"
  31 #endif
  32
  33 #define MAX_PACKET_LENGTH 4096
  34
  35 #include "qemu/sockets.h"
  36 #include "sysemu/hw_accel.h"
  37 #include "sysemu/kvm.h"
  38 #include "exec/semihost.h"
  39 #include "exec/exec-all.h"
  40
  41 #ifdef CONFIG_USER_ONLY
  42 #define GDB_ATTACHED "0"
  43 #else
  44 #define GDB_ATTACHED "1"
  45 #endif
  46
  47 static inline int target_memory_rw_debug(CPUState *cpu, target_ulong addr,
  48                                          uint8_t *buf, int len, bool is_write)
  49 {
  50     CPUClass *cc = CPU_GET_CLASS(cpu);
  51
  52     if (cc->memory_rw_debug) {
  53         return cc->memory_rw_debug(cpu, addr, buf, len, is_write);
  54     }
  55     return cpu_memory_rw_debug(cpu, addr, buf, len, is_write);
  56 }
  57
  58 enum {
  59     GDB_SIGNAL_0 = 0,
  60     GDB_SIGNAL_INT = 2,
  61     GDB_SIGNAL_QUIT = 3,
  62     GDB_SIGNAL_TRAP = 5,
  63     GDB_SIGNAL_ABRT = 6,
  64     GDB_SIGNAL_ALRM = 14,
  65     GDB_SIGNAL_IO = 23,
  66     GDB_SIGNAL_XCPU = 24,
  67     GDB_SIGNAL_UNKNOWN = 143
  68 };
  69
  70 #ifdef CONFIG_USER_ONLY
  71
  72 /* Map target signal numbers to GDB protocol signal numbers and vice
  73  * versa.  For user emulation's currently supported systems, we can
  74  * assume most signals are defined.
  75  */
  76
  77 static int gdb_signal_table[] = {
  78     0,
  79     TARGET_SIGHUP,
  80     TARGET_SIGINT,
  81     TARGET_SIGQUIT,
  82     TARGET_SIGILL,
  83     TARGET_SIGTRAP,
  84     TARGET_SIGABRT,
  85     -1, /* SIGEMT */
  86     TARGET_SIGFPE,
  87     TARGET_SIGKILL,
  88     TARGET_SIGBUS,
  89     TARGET_SIGSEGV,
  90     TARGET_SIGSYS,
  91     TARGET_SIGPIPE,
  92     TARGET_SIGALRM,
  93     TARGET_SIGTERM,
  94     TARGET_SIGURG,
  95     TARGET_SIGSTOP,
  96     TARGET_SIGTSTP,
  97     TARGET_SIGCONT,
  98     TARGET_SIGCHLD,
  99     TARGET_SIGTTIN,
 100     TARGET_SIGTTOU,
 101     TARGET_SIGIO,
 102     TARGET_SIGXCPU,
 103     TARGET_SIGXFSZ,
 104     TARGET_SIGVTALRM,
 105     TARGET_SIGPROF,
 106     TARGET_SIGWINCH,
 107     -1, /* SIGLOST */
 108     TARGET_SIGUSR1,
 109     TARGET_SIGUSR2,
 110 #ifdef TARGET_SIGPWR
 111     TARGET_SIGPWR,
 112 #else
 113     -1,
 114 #endif
 115     -1, /* SIGPOLL */
 116     -1,
 117     -1,
 118     -1,
 119     -1,
 120     -1,
 121     -1,
 122     -1,
 123     -1,
 124     -1,
 125     -1,
 126     -1,
 127 #ifdef __SIGRTMIN
 128     __SIGRTMIN + 1,
 129     __SIGRTMIN + 2,
 130     __SIGRTMIN + 3,
 131     __SIGRTMIN + 4,
 132     __SIGRTMIN + 5,
 133     __SIGRTMIN + 6,
 134     __SIGRTMIN + 7,
 135     __SIGRTMIN + 8,
 136     __SIGRTMIN + 9,
 137     __SIGRTMIN + 10,
 138     __SIGRTMIN + 11,
 139     __SIGRTMIN + 12,
 140     __SIGRTMIN + 13,
 141     __SIGRTMIN + 14,
 142     __SIGRTMIN + 15,
 143     __SIGRTMIN + 16,
 144     __SIGRTMIN + 17,
 145     __SIGRTMIN + 18,
 146     __SIGRTMIN + 19,
 147     __SIGRTMIN + 20,
 148     __SIGRTMIN + 21,
 149     __SIGRTMIN + 22,
 150     __SIGRTMIN + 23,
 151     __SIGRTMIN + 24,
 152     __SIGRTMIN + 25,
 153     __SIGRTMIN + 26,
 154     __SIGRTMIN + 27,
 155     __SIGRTMIN + 28,
 156     __SIGRTMIN + 29,
 157     __SIGRTMIN + 30,
 158     __SIGRTMIN + 31,
 159     -1, /* SIGCANCEL */
 160     __SIGRTMIN,
 161     __SIGRTMIN + 32,
 162     __SIGRTMIN + 33,
 163     __SIGRTMIN + 34,
 164     __SIGRTMIN + 35,
 165     __SIGRTMIN + 36,
 166     __SIGRTMIN + 37,
 167     __SIGRTMIN + 38,
 168     __SIGRTMIN + 39,
 169     __SIGRTMIN + 40,
 170     __SIGRTMIN + 41,
 171     __SIGRTMIN + 42,
 172     __SIGRTMIN + 43,
 173     __SIGRTMIN + 44,
 174     __SIGRTMIN + 45,
 175     __SIGRTMIN + 46,
 176     __SIGRTMIN + 47,
 177     __SIGRTMIN + 48,
 178     __SIGRTMIN + 49,
 179     __SIGRTMIN + 50,
 180     __SIGRTMIN + 51,
 181     __SIGRTMIN + 52,
 182     __SIGRTMIN + 53,
 183     __SIGRTMIN + 54,
 184     __SIGRTMIN + 55,
 185     __SIGRTMIN + 56,
 186     __SIGRTMIN + 57,
 187     __SIGRTMIN + 58,
 188     __SIGRTMIN + 59,
 189     __SIGRTMIN + 60,
 190     __SIGRTMIN + 61,
 191     __SIGRTMIN + 62,
 192     __SIGRTMIN + 63,
 193     __SIGRTMIN + 64,
 194     __SIGRTMIN + 65,
 195     __SIGRTMIN + 66,
 196     __SIGRTMIN + 67,
 197     __SIGRTMIN + 68,
 198     __SIGRTMIN + 69,
 199     __SIGRTMIN + 70,
 200     __SIGRTMIN + 71,
 201     __SIGRTMIN + 72,
 202     __SIGRTMIN + 73,
 203     __SIGRTMIN + 74,
 204     __SIGRTMIN + 75,
 205     __SIGRTMIN + 76,
 206     __SIGRTMIN + 77,
 207     __SIGRTMIN + 78,
 208     __SIGRTMIN + 79,
 209     __SIGRTMIN + 80,
 210     __SIGRTMIN + 81,
 211     __SIGRTMIN + 82,
 212     __SIGRTMIN + 83,
 213     __SIGRTMIN + 84,
 214     __SIGRTMIN + 85,
 215     __SIGRTMIN + 86,
 216     __SIGRTMIN + 87,
 217     __SIGRTMIN + 88,
 218     __SIGRTMIN + 89,
 219     __SIGRTMIN + 90,
 220     __SIGRTMIN + 91,
 221     __SIGRTMIN + 92,
 222     __SIGRTMIN + 93,
 223     __SIGRTMIN + 94,
 224     __SIGRTMIN + 95,
 225     -1, /* SIGINFO */
 226     -1, /* UNKNOWN */
 227     -1, /* DEFAULT */
 228     -1,
 229     -1,
 230     -1,
 231     -1,
 232     -1,
 233     -1
 234 #endif
 235 };
 236 #else
 237 /* In system mode we only need SIGINT and SIGTRAP; other signals
 238    are not yet supported.  */
 239
 240 enum {
 241     TARGET_SIGINT = 2,
 242     TARGET_SIGTRAP = 5
 243 };
 244
 245 static int gdb_signal_table[] = {
 246     -1,
 247     -1,
 248     TARGET_SIGINT,
 249     -1,
 250     -1,
 251     TARGET_SIGTRAP
 252 };
 253 #endif
 254
 255 #ifdef CONFIG_USER_ONLY
 256 static int target_signal_to_gdb (int sig)
 257 {
 258     int i;
 259     for (i = 0; i < ARRAY_SIZE (gdb_signal_table); i++)
 260         if (gdb_signal_table[i] == sig)
 261             return i;
 262     return GDB_SIGNAL_UNKNOWN;
 263 }
 264 #endif
 265
 266 static int gdb_signal_to_target (int sig)
 267 {
 268     if (sig < ARRAY_SIZE (gdb_signal_table))
 269         return gdb_signal_table[sig];
 270     else
 271         return -1;
 272 }
 273
 274 //#define DEBUG_GDB
 275
 276 typedef struct GDBRegisterState {
 277     int base_reg;
 278     int num_regs;
 279     gdb_reg_cb get_reg;
 280     gdb_reg_cb set_reg;
 281     const char *xml;
 282     struct GDBRegisterState *next;
 283 } GDBRegisterState;
 284
 285 enum RSState {
 286     RS_INACTIVE,
 287     RS_IDLE,
 288     RS_GETLINE,
 289     RS_CHKSUM1,
 290     RS_CHKSUM2,
 291 };
 292 typedef struct GDBState {
 293     CPUState *c_cpu; /* current CPU for step/continue ops */
 294     CPUState *g_cpu; /* current CPU for other ops */
 295     CPUState *query_cpu; /* for q{f|s}ThreadInfo */
 296     enum RSState state; /* parsing state */
 297     char line_buf[MAX_PACKET_LENGTH];
 298     int line_buf_index;
 299     int line_csum;
 300     uint8_t last_packet[MAX_PACKET_LENGTH + 4];
 301     int last_packet_len;
 302     int signal;
 303 #ifdef CONFIG_USER_ONLY
 304     int fd;
 305     int running_state;
 306 #else
 307     CharBackend chr;
 308     CharDriverState *mon_chr;
 309 #endif
 310     char syscall_buf[256];
 311     gdb_syscall_complete_cb current_syscall_cb;
 312 } GDBState;
 313
 314 /* By default use no IRQs and no timers while single stepping so as to
 315  * make single stepping like an ICE HW step.
 316  */
 317 static int sstep_flags = SSTEP_ENABLE|SSTEP_NOIRQ|SSTEP_NOTIMER;
 318
 319 static GDBState *gdbserver_state;
 320
 321 bool gdb_has_xml;
 322
 323 #ifdef CONFIG_USER_ONLY
 324 /* XXX: This is not thread safe.  Do we care?  */
 325 static int gdbserver_fd = -1;
 326
 327 static int get_char(GDBState *s)
 328 {
 329     uint8_t ch;
 330     int ret;
 331
 332     for(;;) {
 333         ret = qemu_recv(s->fd, &ch, 1, 0);
 334         if (ret < 0) {
 335             if (errno == ECONNRESET)
 336                 s->fd = -1;
 337             if (errno != EINTR)
 338                 return -1;
 339         } else if (ret == 0) {
 340             close(s->fd);
 341             s->fd = -1;
 342             return -1;
 343         } else {
 344             break;
 345         }
 346     }
 347     return ch;
 348 }
 349 #endif
 350
 351 static enum {
 352     GDB_SYS_UNKNOWN,
 353     GDB_SYS_ENABLED,
 354     GDB_SYS_DISABLED,
 355 } gdb_syscall_mode;
 356
 357 /* Decide if either remote gdb syscalls or native file IO should be used. */
 358 int use_gdb_syscalls(void)
 359 {
 360     SemihostingTarget target = semihosting_get_target();
 361     if (target == SEMIHOSTING_TARGET_NATIVE) {
 362         /* -semihosting-config target=native */
 363         return false;
 364     } else if (target == SEMIHOSTING_TARGET_GDB) {
 365         /* -semihosting-config target=gdb */
 366         return true;
 367     }
 368
 369     /* -semihosting-config target=auto */
 370     /* On the first call check if gdb is connected and remember. */
 371     if (gdb_syscall_mode == GDB_SYS_UNKNOWN) {
 372         gdb_syscall_mode = (gdbserver_state ? GDB_SYS_ENABLED
 373                                             : GDB_SYS_DISABLED);
 374     }
 375     return gdb_syscall_mode == GDB_SYS_ENABLED;
 376 }
 377
 378 /* Resume execution.  */
 379 static inline void gdb_continue(GDBState *s)
 380 {
 381 #ifdef CONFIG_USER_ONLY
 382     s->running_state = 1;
 383 #else
 384     if (!runstate_needs_reset()) {
 385         vm_start();
 386     }
 387 #endif
 388 }
 389
 390 static void put_buffer(GDBState *s, const uint8_t *buf, int len)
 391 {
 392 #ifdef CONFIG_USER_ONLY
 393     int ret;
 394
 395     while (len > 0) {
 396         ret = send(s->fd, buf, len, 0);
 397         if (ret < 0) {
 398             if (errno != EINTR)
 399                 return;
 400         } else {
 401             buf += ret;
 402             len -= ret;
 403         }
 404     }
 405 #else
 406     /* XXX this blocks entire thread. Rewrite to use
 407      * qemu_chr_fe_write and background I/O callbacks */
 408     qemu_chr_fe_write_all(&s->chr, buf, len);
 409 #endif
 410 }
 411
 412 static inline int fromhex(int v)
 413 {
 414     if (v >= '0' && v <= '9')
 415         return v - '0';
 416     else if (v >= 'A' && v <= 'F')
 417         return v - 'A' + 10;
 418     else if (v >= 'a' && v <= 'f')
 419         return v - 'a' + 10;
 420     else
 421         return 0;
 422 }
 423
 424 static inline int tohex(int v)
 425 {
 426     if (v < 10)
 427         return v + '0';
 428     else
 429         return v - 10 + 'a';
 430 }
 431
 432 static void memtohex(char *buf, const uint8_t *mem, int len)
 433 {
 434     int i, c;
 435     char *q;
 436     q = buf;
 437     for(i = 0; i < len; i++) {
 438         c = mem[i];
 439         *q++ = tohex(c >> 4);
 440         *q++ = tohex(c & 0xf);
 441     }
 442     *q = '\0';
 443 }
 444
 445 static void hextomem(uint8_t *mem, const char *buf, int len)
 446 {
 447     int i;
 448
 449     for(i = 0; i < len; i++) {
 450         mem[i] = (fromhex(buf[0]) << 4) | fromhex(buf[1]);
 451         buf += 2;
 452     }
 453 }
 454
 455 /* return -1 if error, 0 if OK */
 456 static int put_packet_binary(GDBState *s, const char *buf, int len)
 457 {
 458     int csum, i;
 459     uint8_t *p;
 460
 461     for(;;) {
 462         p = s->last_packet;
 463         *(p++) = '$';
 464         memcpy(p, buf, len);
 465         p += len;
 466         csum = 0;
 467         for(i = 0; i < len; i++) {
 468             csum += buf[i];
 469         }
 470         *(p++) = '#';
 471         *(p++) = tohex((csum >> 4) & 0xf);
 472         *(p++) = tohex((csum) & 0xf);
 473
 474         s->last_packet_len = p - s->last_packet;
 475         put_buffer(s, (uint8_t *)s->last_packet, s->last_packet_len);
 476
 477 #ifdef CONFIG_USER_ONLY
 478         i = get_char(s);
 479         if (i < 0)
 480             return -1;
 481         if (i == '+')
 482             break;
 483 #else
 484         break;
 485 #endif
 486     }
 487     return 0;
 488 }
 489
 490 /* return -1 if error, 0 if OK */
 491 static int put_packet(GDBState *s, const char *buf)
 492 {
 493 #ifdef DEBUG_GDB
 494     printf("reply='%s'\n", buf);
 495 #endif
 496
 497     return put_packet_binary(s, buf, strlen(buf));
 498 }
 499
 500 /* Encode data using the encoding for 'x' packets.  */
 501 static int memtox(char *buf, const char *mem, int len)
 502 {
 503     char *p = buf;
 504     char c;
 505
 506     while (len--) {
 507         c = *(mem++);
 508         switch (c) {
 509         case '#': case '$': case '*': case '}':
 510             *(p++) = '}';
 511             *(p++) = c ^ 0x20;
 512             break;
 513         default:
 514             *(p++) = c;
 515             break;
 516         }
 517     }
 518     return p - buf;
 519 }
 520
 521 static const char *get_feature_xml(const char *p, const char **newp,
 522                                    CPUClass *cc)
 523 {
 524     size_t len;
 525     int i;
 526     const char *name;
 527     static char target_xml[1024];
 528
 529     len = 0;
 530     while (p[len] && p[len] != ':')
 531         len++;
 532     *newp = p + len;
 533
 534     name = NULL;
 535     if (strncmp(p, "target.xml", len) == 0) {
 536         /* Generate the XML description for this CPU.  */
 537         if (!target_xml[0]) {
 538             GDBRegisterState *r;
 539             CPUState *cpu = first_cpu;
 540
 541             pstrcat(target_xml, sizeof(target_xml),
 542                     "<?xml version=\"1.0\"?>"
 543                     "<!DOCTYPE target SYSTEM \"gdb-target.dtd\">"
 544                     "<target>");
 545             if (cc->gdb_arch_name) {
 546                 gchar *arch = cc->gdb_arch_name(cpu);
 547                 pstrcat(target_xml, sizeof(target_xml), "<architecture>");
 548                 pstrcat(target_xml, sizeof(target_xml), arch);
 549                 pstrcat(target_xml, sizeof(target_xml), "</architecture>");
 550                 g_free(arch);
 551             }
 552             pstrcat(target_xml, sizeof(target_xml), "<xi:include href=\"");
 553             pstrcat(target_xml, sizeof(target_xml), cc->gdb_core_xml_file);
 554             pstrcat(target_xml, sizeof(target_xml), "\"/>");
 555             for (r = cpu->gdb_regs; r; r = r->next) {
 556                 pstrcat(target_xml, sizeof(target_xml), "<xi:include href=\"");
 557                 pstrcat(target_xml, sizeof(target_xml), r->xml);
 558                 pstrcat(target_xml, sizeof(target_xml), "\"/>");
 559             }
 560             pstrcat(target_xml, sizeof(target_xml), "</target>");
 561         }
 562         return target_xml;
 563     }
 564     for (i = 0; ; i++) {
 565         name = xml_builtin[i][0];
 566         if (!name || (strncmp(name, p, len) == 0 && strlen(name) == len))
 567             break;
 568     }
 569     return name ? xml_builtin[i][1] : NULL;
 570 }
 571
 572 static int gdb_read_register(CPUState *cpu, uint8_t *mem_buf, int reg)
 573 {
 574     CPUClass *cc = CPU_GET_CLASS(cpu);
 575     CPUArchState *env = cpu->env_ptr;
 576     GDBRegisterState *r;
 577
 578     if (reg < cc->gdb_num_core_regs) {
 579         return cc->gdb_read_register(cpu, mem_buf, reg);
 580     }
 581
 582     for (r = cpu->gdb_regs; r; r = r->next) {
 583         if (r->base_reg <= reg && reg < r->base_reg + r->num_regs) {
 584             return r->get_reg(env, mem_buf, reg - r->base_reg);
 585         }
 586     }
 587     return 0;
 588 }
 589
 590 static int gdb_write_register(CPUState *cpu, uint8_t *mem_buf, int reg)
 591 {
 592     CPUClass *cc = CPU_GET_CLASS(cpu);
 593     CPUArchState *env = cpu->env_ptr;
 594     GDBRegisterState *r;
 595
 596     if (reg < cc->gdb_num_core_regs) {
 597         return cc->gdb_write_register(cpu, mem_buf, reg);
 598     }
 599
 600     for (r = cpu->gdb_regs; r; r = r->next) {
 601         if (r->base_reg <= reg && reg < r->base_reg + r->num_regs) {
 602             return r->set_reg(env, mem_buf, reg - r->base_reg);
 603         }
 604     }
 605     return 0;
 606 }
 607
 608 /* Register a supplemental set of CPU registers.  If g_pos is nonzero it
 609    specifies the first register number and these registers are included in
 610    a standard "g" packet.  Direction is relative to gdb, i.e. get_reg is
 611    gdb reading a CPU register, and set_reg is gdb modifying a CPU register.
 612  */
 613
 614 void gdb_register_coprocessor(CPUState *cpu,
 615                               gdb_reg_cb get_reg, gdb_reg_cb set_reg,
 616                               int num_regs, const char *xml, int g_pos)
 617 {
 618     GDBRegisterState *s;
 619     GDBRegisterState **p;
 620
 621     p = &cpu->gdb_regs;
 622     while (*p) {
 623         /* Check for duplicates.  */
 624         if (strcmp((*p)->xml, xml) == 0)
 625             return;
 626         p = &(*p)->next;
 627     }
 628
 629     s = g_new0(GDBRegisterState, 1);
 630     s->base_reg = cpu->gdb_num_regs;
 631     s->num_regs = num_regs;
 632     s->get_reg = get_reg;
 633     s->set_reg = set_reg;
 634     s->xml = xml;
 635
 636     /* Add to end of list.  */
 637     cpu->gdb_num_regs += num_regs;
 638     *p = s;
 639     if (g_pos) {
 640         if (g_pos != s->base_reg) {
 641             error_report("Error: Bad gdb register numbering for '%s', "
 642                          "expected %d got %d", xml, g_pos, s->base_reg);
 643         } else {
 644             cpu->gdb_num_g_regs = cpu->gdb_num_regs;
 645         }
 646     }
 647 }
 648
 649 #ifndef CONFIG_USER_ONLY
 650 /* Translate GDB watchpoint type to a flags value for cpu_watchpoint_* */
 651 static inline int xlat_gdb_type(CPUState *cpu, int gdbtype)
 652 {
 653     static const int xlat[] = {
 654         [GDB_WATCHPOINT_WRITE]  = BP_GDB | BP_MEM_WRITE,
 655         [GDB_WATCHPOINT_READ]   = BP_GDB | BP_MEM_READ,
 656         [GDB_WATCHPOINT_ACCESS] = BP_GDB | BP_MEM_ACCESS,
 657     };
 658
 659     CPUClass *cc = CPU_GET_CLASS(cpu);
 660     int cputype = xlat[gdbtype];
 661
 662     if (cc->gdb_stop_before_watchpoint) {
 663         cputype |= BP_STOP_BEFORE_ACCESS;
 664     }
 665     return cputype;
 666 }
 667 #endif
 668
 669 static int gdb_breakpoint_insert(target_ulong addr, target_ulong len, int type)
 670 {
 671     CPUState *cpu;
 672     int err = 0;
 673
 674     if (kvm_enabled()) {
 675         return kvm_insert_breakpoint(gdbserver_state->c_cpu, addr, len, type);
 676     }
 677
 678     switch (type) {
 679     case GDB_BREAKPOINT_SW:
 680     case GDB_BREAKPOINT_HW:
 681         CPU_FOREACH(cpu) {
 682             err = cpu_breakpoint_insert(cpu, addr, BP_GDB, NULL);
 683             if (err) {
 684                 break;
 685             }
 686         }
 687         return err;
 688 #ifndef CONFIG_USER_ONLY
 689     case GDB_WATCHPOINT_WRITE:
 690     case GDB_WATCHPOINT_READ:
 691     case GDB_WATCHPOINT_ACCESS:
 692         CPU_FOREACH(cpu) {
 693             err = cpu_watchpoint_insert(cpu, addr, len,
 694                                         xlat_gdb_type(cpu, type), NULL);
 695             if (err) {
 696                 break;
 697             }
 698         }
 699         return err;
 700 #endif
 701     default:
 702         return -ENOSYS;
 703     }
 704 }
 705
 706 static int gdb_breakpoint_remove(target_ulong addr, target_ulong len, int type)
 707 {
 708     CPUState *cpu;
 709     int err = 0;
 710
 711     if (kvm_enabled()) {
 712         return kvm_remove_breakpoint(gdbserver_state->c_cpu, addr, len, type);
 713     }
 714
 715     switch (type) {
 716     case GDB_BREAKPOINT_SW:
 717     case GDB_BREAKPOINT_HW:
 718         CPU_FOREACH(cpu) {
 719             err = cpu_breakpoint_remove(cpu, addr, BP_GDB);
 720             if (err) {
 721                 break;
 722             }
 723         }
 724         return err;
 725 #ifndef CONFIG_USER_ONLY
 726     case GDB_WATCHPOINT_WRITE:
 727     case GDB_WATCHPOINT_READ:
 728     case GDB_WATCHPOINT_ACCESS:
 729         CPU_FOREACH(cpu) {
 730             err = cpu_watchpoint_remove(cpu, addr, len,
 731                                         xlat_gdb_type(cpu, type));
 732             if (err)
 733                 break;
 734         }
 735         return err;
 736 #endif
 737     default:
 738         return -ENOSYS;
 739     }
 740 }
 741
 742 static void gdb_breakpoint_remove_all(void)
 743 {
 744     CPUState *cpu;
 745
 746     if (kvm_enabled()) {
 747         kvm_remove_all_breakpoints(gdbserver_state->c_cpu);
 748         return;
 749     }
 750
 751     CPU_FOREACH(cpu) {
 752         cpu_breakpoint_remove_all(cpu, BP_GDB);
 753 #ifndef CONFIG_USER_ONLY
 754         cpu_watchpoint_remove_all(cpu, BP_GDB);
 755 #endif
 756     }
 757 }
 758
 759 static void gdb_set_cpu_pc(GDBState *s, target_ulong pc)
 760 {
 761     CPUState *cpu = s->c_cpu;
 762
 763     cpu_synchronize_state(cpu);
 764     cpu_set_pc(cpu, pc);
 765 }
 766
 767 static CPUState *find_cpu(uint32_t thread_id)
 768 {
 769     CPUState *cpu;
 770
 771     CPU_FOREACH(cpu) {
 772         if (cpu_index(cpu) == thread_id) {
 773             return cpu;
 774         }
 775     }
 776
 777     return NULL;
 778 }
 779
 780 static int is_query_packet(const char *p, const char *query, char separator)
 781 {
 782     unsigned int query_len = strlen(query);
 783
 784     return strncmp(p, query, query_len) == 0 &&
 785         (p[query_len] == '\0' || p[query_len] == separator);
 786 }
 787
 788 static int gdb_handle_packet(GDBState *s, const char *line_buf)
 789 {
 790     CPUState *cpu;
 791     CPUClass *cc;
 792     const char *p;
 793     uint32_t thread;
 794     int ch, reg_size, type, res;
 795     char buf[MAX_PACKET_LENGTH];
 796     uint8_t mem_buf[MAX_PACKET_LENGTH];
 797     uint8_t *registers;
 798     target_ulong addr, len;
 799
 800 #ifdef DEBUG_GDB
 801     printf("command='%s'\n", line_buf);
 802 #endif
 803     p = line_buf;
 804     ch = *p++;
 805     switch(ch) {
 806     case '?':
 807         /* TODO: Make this return the correct value for user-mode.  */
 808         snprintf(buf, sizeof(buf), "T%02xthread:%02x;", GDB_SIGNAL_TRAP,
 809                  cpu_index(s->c_cpu));
 810         put_packet(s, buf);
 811         /* Remove all the breakpoints when this query is issued,
 812          * because gdb is doing and initial connect and the state
 813          * should be cleaned up.
 814          */
 815         gdb_breakpoint_remove_all();
 816         break;
 817     case 'c':
 818         if (*p != '\0') {
 819             addr = strtoull(p, (char **)&p, 16);
 820             gdb_set_cpu_pc(s, addr);
 821         }
 822         s->signal = 0;
 823         gdb_continue(s);
 824         return RS_IDLE;
 825     case 'C':
 826         s->signal = gdb_signal_to_target (strtoul(p, (char **)&p, 16));
 827         if (s->signal == -1)
 828             s->signal = 0;
 829         gdb_continue(s);
 830         return RS_IDLE;
 831     case 'v':
 832         if (strncmp(p, "Cont", 4) == 0) {
 833             int res_signal, res_thread;
 834
 835             p += 4;
 836             if (*p == '?') {
 837                 put_packet(s, "vCont;c;C;s;S");
 838                 break;
 839             }
 840             res = 0;
 841             res_signal = 0;
 842             res_thread = 0;
 843             while (*p) {
 844                 int action, signal;
 845
 846                 if (*p++ != ';') {
 847                     res = 0;
 848                     break;
 849                 }
 850                 action = *p++;
 851                 signal = 0;
 852                 if (action == 'C' || action == 'S') {
 853                     signal = gdb_signal_to_target(strtoul(p, (char **)&p, 16));
 854                     if (signal == -1) {
 855                         signal = 0;
 856                     }
 857                 } else if (action != 'c' && action != 's') {
 858                     res = 0;
 859                     break;
 860                 }
 861                 thread = 0;
 862                 if (*p == ':') {
 863                     thread = strtoull(p+1, (char **)&p, 16);
 864                 }
 865                 action = tolower(action);
 866                 if (res == 0 || (res == 'c' && action == 's')) {
 867                     res = action;
 868                     res_signal = signal;
 869                     res_thread = thread;
 870                 }
 871             }
 872             if (res) {
 873                 if (res_thread != -1 && res_thread != 0) {
 874                     cpu = find_cpu(res_thread);
 875                     if (cpu == NULL) {
 876                         put_packet(s, "E22");
 877                         break;
 878                     }
 879                     s->c_cpu = cpu;
 880                 }
 881                 if (res == 's') {
 882                     cpu_single_step(s->c_cpu, sstep_flags);
 883                 }
 884                 s->signal = res_signal;
 885                 gdb_continue(s);
 886                 return RS_IDLE;
 887             }
 888             break;
 889         } else {
 890             goto unknown_command;
 891         }
 892     case 'k':
 893         /* Kill the target */
 894         error_report("QEMU: Terminated via GDBstub");
 895         exit(0);
 896     case 'D':
 897         /* Detach packet */
 898         gdb_breakpoint_remove_all();
 899         gdb_syscall_mode = GDB_SYS_DISABLED;
 900         gdb_continue(s);
 901         put_packet(s, "OK");
 902         break;
 903     case 's':
 904         if (*p != '\0') {
 905             addr = strtoull(p, (char **)&p, 16);
 906             gdb_set_cpu_pc(s, addr);
 907         }
 908         cpu_single_step(s->c_cpu, sstep_flags);
 909         gdb_continue(s);
 910         return RS_IDLE;
 911     case 'F':
 912         {
 913             target_ulong ret;
 914             target_ulong err;
 915
 916             ret = strtoull(p, (char **)&p, 16);
 917             if (*p == ',') {
 918                 p++;
 919                 err = strtoull(p, (char **)&p, 16);
 920             } else {
 921                 err = 0;
 922             }
 923             if (*p == ',')
 924                 p++;
 925             type = *p;
 926             if (s->current_syscall_cb) {
 927                 s->current_syscall_cb(s->c_cpu, ret, err);
 928                 s->current_syscall_cb = NULL;
 929             }
 930             if (type == 'C') {
 931                 put_packet(s, "T02");
 932             } else {
 933                 gdb_continue(s);
 934             }
 935         }
 936         break;
 937     case 'g':
 938         cpu_synchronize_state(s->g_cpu);
 939         len = 0;
 940         for (addr = 0; addr < s->g_cpu->gdb_num_g_regs; addr++) {
 941             reg_size = gdb_read_register(s->g_cpu, mem_buf + len, addr);
 942             len += reg_size;
 943         }
 944         memtohex(buf, mem_buf, len);
 945         put_packet(s, buf);
 946         break;
 947     case 'G':
 948         cpu_synchronize_state(s->g_cpu);
 949         registers = mem_buf;
 950         len = strlen(p) / 2;
 951         hextomem((uint8_t *)registers, p, len);
 952         for (addr = 0; addr < s->g_cpu->gdb_num_g_regs && len > 0; addr++) {
 953             reg_size = gdb_write_register(s->g_cpu, registers, addr);
 954             len -= reg_size;
 955             registers += reg_size;
 956         }
 957         put_packet(s, "OK");
 958         break;
 959     case 'm':
 960         addr = strtoull(p, (char **)&p, 16);
 961         if (*p == ',')
 962             p++;
 963         len = strtoull(p, NULL, 16);
 964
 965         /* memtohex() doubles the required space */
 966         if (len > MAX_PACKET_LENGTH / 2) {
 967             put_packet (s, "E22");
 968             break;
 969         }
 970
 971         if (target_memory_rw_debug(s->g_cpu, addr, mem_buf, len, false) != 0) {
 972             put_packet (s, "E14");
 973         } else {
 974             memtohex(buf, mem_buf, len);
 975             put_packet(s, buf);
 976         }
 977         break;
 978     case 'M':
 979         addr = strtoull(p, (char **)&p, 16);
 980         if (*p == ',')
 981             p++;
 982         len = strtoull(p, (char **)&p, 16);
 983         if (*p == ':')
 984             p++;
 985
 986         /* hextomem() reads 2*len bytes */
 987         if (len > strlen(p) / 2) {
 988             put_packet (s, "E22");
 989             break;
 990         }
 991         hextomem(mem_buf, p, len);
 992         if (target_memory_rw_debug(s->g_cpu, addr, mem_buf, len,
 993                                    true) != 0) {
 994             put_packet(s, "E14");
 995         } else {
 996             put_packet(s, "OK");
 997         }
 998         break;
 999     case 'p':
1000         /* Older gdb are really dumb, and don't use 'g' if 'p' is avaialable.
1001            This works, but can be very slow.  Anything new enough to
1002            understand XML also knows how to use this properly.  */
1003         if (!gdb_has_xml)
1004             goto unknown_command;
1005         addr = strtoull(p, (char **)&p, 16);
1006         reg_size = gdb_read_register(s->g_cpu, mem_buf, addr);
1007         if (reg_size) {
1008             memtohex(buf, mem_buf, reg_size);
1009             put_packet(s, buf);
1010         } else {
1011             put_packet(s, "E14");
1012         }
1013         break;
1014     case 'P':
1015         if (!gdb_has_xml)
1016             goto unknown_command;
1017         addr = strtoull(p, (char **)&p, 16);
1018         if (*p == '=')
1019             p++;
1020         reg_size = strlen(p) / 2;
1021         hextomem(mem_buf, p, reg_size);
1022         gdb_write_register(s->g_cpu, mem_buf, addr);
1023         put_packet(s, "OK");
1024         break;
1025     case 'Z':
1026     case 'z':
1027         type = strtoul(p, (char **)&p, 16);
1028         if (*p == ',')
1029             p++;
1030         addr = strtoull(p, (char **)&p, 16);
1031         if (*p == ',')
1032             p++;
1033         len = strtoull(p, (char **)&p, 16);
1034         if (ch == 'Z')
1035             res = gdb_breakpoint_insert(addr, len, type);
1036         else
1037             res = gdb_breakpoint_remove(addr, len, type);
1038         if (res >= 0)
1039              put_packet(s, "OK");
1040         else if (res == -ENOSYS)
1041             put_packet(s, "");
1042         else
1043             put_packet(s, "E22");
1044         break;
1045     case 'H':
1046         type = *p++;
1047         thread = strtoull(p, (char **)&p, 16);
1048         if (thread == -1 || thread == 0) {
1049             put_packet(s, "OK");
1050             break;
1051         }
1052         cpu = find_cpu(thread);
1053         if (cpu == NULL) {
1054             put_packet(s, "E22");
1055             break;
1056         }
1057         switch (type) {
1058         case 'c':
1059             s->c_cpu = cpu;
1060             put_packet(s, "OK");
1061             break;
1062         case 'g':
1063             s->g_cpu = cpu;
1064             put_packet(s, "OK");
1065             break;
1066         default:
1067              put_packet(s, "E22");
1068              break;
1069         }
1070         break;
1071     case 'T':
1072         thread = strtoull(p, (char **)&p, 16);
1073         cpu = find_cpu(thread);
1074
1075         if (cpu != NULL) {
1076             put_packet(s, "OK");
1077         } else {
1078             put_packet(s, "E22");
1079         }
1080         break;
1081     case 'q':
1082     case 'Q':
1083         /* parse any 'q' packets here */
1084         if (!strcmp(p,"qemu.sstepbits")) {
1085             /* Query Breakpoint bit definitions */
1086             snprintf(buf, sizeof(buf), "ENABLE=%x,NOIRQ=%x,NOTIMER=%x",
1087                      SSTEP_ENABLE,
1088                      SSTEP_NOIRQ,
1089                      SSTEP_NOTIMER);
1090             put_packet(s, buf);
1091             break;
1092         } else if (is_query_packet(p, "qemu.sstep", '=')) {
1093             /* Display or change the sstep_flags */
1094             p += 10;
1095             if (*p != '=') {
1096                 /* Display current setting */
1097                 snprintf(buf, sizeof(buf), "0x%x", sstep_flags);
1098                 put_packet(s, buf);
1099                 break;
1100             }
1101             p++;
1102             type = strtoul(p, (char **)&p, 16);
1103             sstep_flags = type;
1104             put_packet(s, "OK");
1105             break;
1106         } else if (strcmp(p,"C") == 0) {
1107             /* "Current thread" remains vague in the spec, so always return
1108              *  the first CPU (gdb returns the first thread). */
1109             put_packet(s, "QC1");
1110             break;
1111         } else if (strcmp(p,"fThreadInfo") == 0) {
1112             s->query_cpu = first_cpu;
1113             goto report_cpuinfo;
1114         } else if (strcmp(p,"sThreadInfo") == 0) {
1115         report_cpuinfo:
1116             if (s->query_cpu) {
1117                 snprintf(buf, sizeof(buf), "m%x", cpu_index(s->query_cpu));
1118                 put_packet(s, buf);
1119                 s->query_cpu = CPU_NEXT(s->query_cpu);
1120             } else
1121                 put_packet(s, "l");
1122             break;
1123         } else if (strncmp(p,"ThreadExtraInfo,", 16) == 0) {
1124             thread = strtoull(p+16, (char **)&p, 16);
1125             cpu = find_cpu(thread);
1126             if (cpu != NULL) {
1127                 cpu_synchronize_state(cpu);
1128                 /* memtohex() doubles the required space */
1129                 len = snprintf((char *)mem_buf, sizeof(buf) / 2,
1130                                "CPU#%d [%s]", cpu->cpu_index,
1131                                cpu->halted ? "halted " : "running");
1132                 memtohex(buf, mem_buf, len);
1133                 put_packet(s, buf);
1134             }
1135             break;
1136         }
1137 #ifdef CONFIG_USER_ONLY
1138         else if (strcmp(p, "Offsets") == 0) {
1139             TaskState *ts = s->c_cpu->opaque;
1140
1141             snprintf(buf, sizeof(buf),
1142                      "Text=" TARGET_ABI_FMT_lx ";Data=" TARGET_ABI_FMT_lx
1143                      ";Bss=" TARGET_ABI_FMT_lx,
1144                      ts->info->code_offset,
1145                      ts->info->data_offset,
1146                      ts->info->data_offset);
1147             put_packet(s, buf);
1148             break;
1149         }
1150 #else /* !CONFIG_USER_ONLY */
1151         else if (strncmp(p, "Rcmd,", 5) == 0) {
1152             int len = strlen(p + 5);
1153
1154             if ((len % 2) != 0) {
1155                 put_packet(s, "E01");
1156                 break;
1157             }
1158             len = len / 2;
1159             hextomem(mem_buf, p + 5, len);
1160             mem_buf[len++] = 0;
1161             qemu_chr_be_write(s->mon_chr, mem_buf, len);
1162             put_packet(s, "OK");
1163             break;
1164         }
1165 #endif /* !CONFIG_USER_ONLY */
1166         if (is_query_packet(p, "Supported", ':')) {
1167             snprintf(buf, sizeof(buf), "PacketSize=%x", MAX_PACKET_LENGTH);
1168             cc = CPU_GET_CLASS(first_cpu);
1169             if (cc->gdb_core_xml_file != NULL) {
1170                 pstrcat(buf, sizeof(buf), ";qXfer:features:read+");
1171             }
1172             put_packet(s, buf);
1173             break;
1174         }
1175         if (strncmp(p, "Xfer:features:read:", 19) == 0) {
1176             const char *xml;
1177             target_ulong total_len;
1178
1179             cc = CPU_GET_CLASS(first_cpu);
1180             if (cc->gdb_core_xml_file == NULL) {
1181                 goto unknown_command;
1182             }
1183
1184             gdb_has_xml = true;
1185             p += 19;
1186             xml = get_feature_xml(p, &p, cc);
1187             if (!xml) {
1188                 snprintf(buf, sizeof(buf), "E00");
1189                 put_packet(s, buf);
1190                 break;
1191             }
1192
1193             if (*p == ':')
1194                 p++;
1195             addr = strtoul(p, (char **)&p, 16);
1196             if (*p == ',')
1197                 p++;
1198             len = strtoul(p, (char **)&p, 16);
1199
1200             total_len = strlen(xml);
1201             if (addr > total_len) {
1202                 snprintf(buf, sizeof(buf), "E00");
1203                 put_packet(s, buf);
1204                 break;
1205             }
1206             if (len > (MAX_PACKET_LENGTH - 5) / 2)
1207                 len = (MAX_PACKET_LENGTH - 5) / 2;
1208             if (len < total_len - addr) {
1209                 buf[0] = 'm';
1210                 len = memtox(buf + 1, xml + addr, len);
1211             } else {
1212                 buf[0] = 'l';
1213                 len = memtox(buf + 1, xml + addr, total_len - addr);
1214             }
1215             put_packet_binary(s, buf, len + 1);
1216             break;
1217         }
1218         if (is_query_packet(p, "Attached", ':')) {
1219             put_packet(s, GDB_ATTACHED);
1220             break;
1221         }
1222         /* Unrecognised 'q' command.  */
1223         goto unknown_command;
1224
1225     default:
1226     unknown_command:
1227         /* put empty packet */
1228         buf[0] = '\0';
1229         put_packet(s, buf);
1230         break;
1231     }
1232     return RS_IDLE;
1233 }
1234
1235 void gdb_set_stop_cpu(CPUState *cpu)
1236 {
1237     gdbserver_state->c_cpu = cpu;
1238     gdbserver_state->g_cpu = cpu;
1239 }
1240
1241 #ifndef CONFIG_USER_ONLY
1242 static void gdb_vm_state_change(void *opaque, int running, RunState state)
1243 {
1244     GDBState *s = gdbserver_state;
1245     CPUState *cpu = s->c_cpu;
1246     char buf[256];
1247     const char *type;
1248     int ret;
1249
1250     if (running || s->state == RS_INACTIVE) {
1251         return;
1252     }
1253     /* Is there a GDB syscall waiting to be sent?  */
1254     if (s->current_syscall_cb) {
1255         put_packet(s, s->syscall_buf);
1256         return;
1257     }
1258     switch (state) {
1259     case RUN_STATE_DEBUG:
1260         if (cpu->watchpoint_hit) {
1261             switch (cpu->watchpoint_hit->flags & BP_MEM_ACCESS) {
1262             case BP_MEM_READ:
1263                 type = "r";
1264                 break;
1265             case BP_MEM_ACCESS:
1266                 type = "a";
1267                 break;
1268             default:
1269                 type = "";
1270                 break;
1271             }
1272             snprintf(buf, sizeof(buf),
1273                      "T%02xthread:%02x;%swatch:" TARGET_FMT_lx ";",
1274                      GDB_SIGNAL_TRAP, cpu_index(cpu), type,
1275                      (target_ulong)cpu->watchpoint_hit->vaddr);
1276             cpu->watchpoint_hit = NULL;
1277             goto send_packet;
1278         }
1279         tb_flush(cpu);
1280         ret = GDB_SIGNAL_TRAP;
1281         break;
1282     case RUN_STATE_PAUSED:
1283         ret = GDB_SIGNAL_INT;
1284         break;
1285     case RUN_STATE_SHUTDOWN:
1286         ret = GDB_SIGNAL_QUIT;
1287         break;
1288     case RUN_STATE_IO_ERROR:
1289         ret = GDB_SIGNAL_IO;
1290         break;
1291     case RUN_STATE_WATCHDOG:
1292         ret = GDB_SIGNAL_ALRM;
1293         break;
1294     case RUN_STATE_INTERNAL_ERROR:
1295         ret = GDB_SIGNAL_ABRT;
1296         break;
1297     case RUN_STATE_SAVE_VM:
1298     case RUN_STATE_RESTORE_VM:
1299         return;
1300     case RUN_STATE_FINISH_MIGRATE:
1301         ret = GDB_SIGNAL_XCPU;
1302         break;
1303     default:
1304         ret = GDB_SIGNAL_UNKNOWN;
1305         break;
1306     }
1307     gdb_set_stop_cpu(cpu);
1308     snprintf(buf, sizeof(buf), "T%02xthread:%02x;", ret, cpu_index(cpu));
1309
1310 send_packet:
1311     put_packet(s, buf);
1312
1313     /* disable single step if it was enabled */
1314     cpu_single_step(cpu, 0);
1315 }
1316 #endif
1317
1318 /* Send a gdb syscall request.
1319    This accepts limited printf-style format specifiers, specifically:
1320     %x  - target_ulong argument printed in hex.
1321     %lx - 64-bit argument printed in hex.
1322     %s  - string pointer (target_ulong) and length (int) pair.  */
1323 void gdb_do_syscallv(gdb_syscall_complete_cb cb, const char *fmt, va_list va)
1324 {
1325     char *p;
1326     char *p_end;
1327     target_ulong addr;
1328     uint64_t i64;
1329     GDBState *s;
1330
1331     s = gdbserver_state;
1332     if (!s)
1333         return;
1334     s->current_syscall_cb = cb;
1335 #ifndef CONFIG_USER_ONLY
1336     vm_stop(RUN_STATE_DEBUG);
1337 #endif
1338     p = s->syscall_buf;
1339     p_end = &s->syscall_buf[sizeof(s->syscall_buf)];
1340     *(p++) = 'F';
1341     while (*fmt) {
1342         if (*fmt == '%') {
1343             fmt++;
1344             switch (*fmt++) {
1345             case 'x':
1346                 addr = va_arg(va, target_ulong);
1347                 p += snprintf(p, p_end - p, TARGET_FMT_lx, addr);
1348                 break;
1349             case 'l':
1350                 if (*(fmt++) != 'x')
1351                     goto bad_format;
1352                 i64 = va_arg(va, uint64_t);
1353                 p += snprintf(p, p_end - p, "%" PRIx64, i64);
1354                 break;
1355             case 's':
1356                 addr = va_arg(va, target_ulong);
1357                 p += snprintf(p, p_end - p, TARGET_FMT_lx "/%x",
1358                               addr, va_arg(va, int));
1359                 break;
1360             default:
1361             bad_format:
1362                 error_report("gdbstub: Bad syscall format string '%s'",
1363                              fmt - 1);
1364                 break;
1365             }
1366         } else {
1367             *(p++) = *(fmt++);
1368         }
1369     }
1370     *p = 0;
1371 #ifdef CONFIG_USER_ONLY
1372     put_packet(s, s->syscall_buf);
1373     gdb_handlesig(s->c_cpu, 0);
1374 #else
1375     /* In this case wait to send the syscall packet until notification that
1376        the CPU has stopped.  This must be done because if the packet is sent
1377        now the reply from the syscall request could be received while the CPU
1378        is still in the running state, which can cause packets to be dropped
1379        and state transition 'T' packets to be sent while the syscall is still
1380        being processed.  */
1381     qemu_cpu_kick(s->c_cpu);
1382 #endif
1383 }
1384
1385 void gdb_do_syscall(gdb_syscall_complete_cb cb, const char *fmt, ...)
1386 {
1387     va_list va;
1388
1389     va_start(va, fmt);
1390     gdb_do_syscallv(cb, fmt, va);
1391     va_end(va);
1392 }
1393
1394 static void gdb_read_byte(GDBState *s, int ch)
1395 {
1396     int i, csum;
1397     uint8_t reply;
1398
1399 #ifndef CONFIG_USER_ONLY
1400     if (s->last_packet_len) {
1401         /* Waiting for a response to the last packet.  If we see the start
1402            of a new command then abandon the previous response.  */
1403         if (ch == '-') {
1404 #ifdef DEBUG_GDB
1405             printf("Got NACK, retransmitting\n");
1406 #endif
1407             put_buffer(s, (uint8_t *)s->last_packet, s->last_packet_len);
1408         }
1409 #ifdef DEBUG_GDB
1410         else if (ch == '+')
1411             printf("Got ACK\n");
1412         else
1413             printf("Got '%c' when expecting ACK/NACK\n", ch);
1414 #endif
1415         if (ch == '+' || ch == '$')
1416             s->last_packet_len = 0;
1417         if (ch != '$')
1418             return;
1419     }
1420     if (runstate_is_running()) {
1421         /* when the CPU is running, we cannot do anything except stop
1422            it when receiving a char */
1423         vm_stop(RUN_STATE_PAUSED);
1424     } else
1425 #endif
1426     {
1427         switch(s->state) {
1428         case RS_IDLE:
1429             if (ch == '$') {
1430                 s->line_buf_index = 0;
1431                 s->state = RS_GETLINE;
1432             }
1433             break;
1434         case RS_GETLINE:
1435             if (ch == '#') {
1436             s->state = RS_CHKSUM1;
1437             } else if (s->line_buf_index >= sizeof(s->line_buf) - 1) {
1438                 s->state = RS_IDLE;
1439             } else {
1440             s->line_buf[s->line_buf_index++] = ch;
1441             }
1442             break;
1443         case RS_CHKSUM1:
1444             s->line_buf[s->line_buf_index] = '\0';
1445             s->line_csum = fromhex(ch) << 4;
1446             s->state = RS_CHKSUM2;
1447             break;
1448         case RS_CHKSUM2:
1449             s->line_csum |= fromhex(ch);
1450             csum = 0;
1451             for(i = 0; i < s->line_buf_index; i++) {
1452                 csum += s->line_buf[i];
1453             }
1454             if (s->line_csum != (csum & 0xff)) {
1455                 reply = '-';
1456                 put_buffer(s, &reply, 1);
1457                 s->state = RS_IDLE;
1458             } else {
1459                 reply = '+';
1460                 put_buffer(s, &reply, 1);
1461                 s->state = gdb_handle_packet(s, s->line_buf);
1462             }
1463             break;
1464         default:
1465             abort();
1466         }
1467     }
1468 }
1469
1470 /* Tell the remote gdb that the process has exited.  */
1471 void gdb_exit(CPUArchState *env, int code)
1472 {
1473   GDBState *s;
1474   char buf[4];
1475 #ifndef CONFIG_USER_ONLY
1476   CharDriverState *chr;
1477 #endif
1478
1479   s = gdbserver_state;
1480   if (!s) {
1481       return;
1482   }
1483 #ifdef CONFIG_USER_ONLY
1484   if (gdbserver_fd < 0 || s->fd < 0) {
1485       return;
1486   }
1487 #else
1488   chr = qemu_chr_fe_get_driver(&s->chr);
1489   if (!chr) {
1490       return;
1491   }
1492 #endif
1493
1494   snprintf(buf, sizeof(buf), "W%02x", (uint8_t)code);
1495   put_packet(s, buf);
1496
1497 #ifndef CONFIG_USER_ONLY
1498   qemu_chr_fe_deinit(&s->chr);
1499   qemu_chr_delete(chr);
1500 #endif
1501 }
1502
1503 #ifdef CONFIG_USER_ONLY
1504 int
1505 gdb_handlesig(CPUState *cpu, int sig)
1506 {
1507     GDBState *s;
1508     char buf[256];
1509     int n;
1510
1511     s = gdbserver_state;
1512     if (gdbserver_fd < 0 || s->fd < 0) {
1513         return sig;
1514     }
1515
1516     /* disable single step if it was enabled */
1517     cpu_single_step(cpu, 0);
1518     tb_flush(cpu);
1519
1520     if (sig != 0) {
1521         snprintf(buf, sizeof(buf), "S%02x", target_signal_to_gdb(sig));
1522         put_packet(s, buf);
1523     }
1524     /* put_packet() might have detected that the peer terminated the
1525        connection.  */
1526     if (s->fd < 0) {
1527         return sig;
1528     }
1529
1530     sig = 0;
1531     s->state = RS_IDLE;
1532     s->running_state = 0;
1533     while (s->running_state == 0) {
1534         n = read(s->fd, buf, 256);
1535         if (n > 0) {
1536             int i;
1537
1538             for (i = 0; i < n; i++) {
1539                 gdb_read_byte(s, buf[i]);
1540             }
1541         } else {
1542             /* XXX: Connection closed.  Should probably wait for another
1543                connection before continuing.  */
1544             if (n == 0) {
1545                 close(s->fd);
1546             }
1547             s->fd = -1;
1548             return sig;
1549         }
1550     }
1551     sig = s->signal;
1552     s->signal = 0;
1553     return sig;
1554 }
1555
1556 /* Tell the remote gdb that the process has exited due to SIG.  */
1557 void gdb_signalled(CPUArchState *env, int sig)
1558 {
1559     GDBState *s;
1560     char buf[4];
1561
1562     s = gdbserver_state;
1563     if (gdbserver_fd < 0 || s->fd < 0) {
1564         return;
1565     }
1566
1567     snprintf(buf, sizeof(buf), "X%02x", target_signal_to_gdb(sig));
1568     put_packet(s, buf);
1569 }
1570
1571 static void gdb_accept(void)
1572 {
1573     GDBState *s;
1574     struct sockaddr_in sockaddr;
1575     socklen_t len;
1576     int fd;
1577
1578     for(;;) {
1579         len = sizeof(sockaddr);
1580         fd = accept(gdbserver_fd, (struct sockaddr *)&sockaddr, &len);
1581         if (fd < 0 && errno != EINTR) {
1582             perror("accept");
1583             return;
1584         } else if (fd >= 0) {
1585 #ifndef _WIN32
1586             fcntl(fd, F_SETFD, FD_CLOEXEC);
1587 #endif
1588             break;
1589         }
1590     }
1591
1592     /* set short latency */
1593     socket_set_nodelay(fd);
1594
1595     s = g_malloc0(sizeof(GDBState));
1596     s->c_cpu = first_cpu;
1597     s->g_cpu = first_cpu;
1598     s->fd = fd;
1599     gdb_has_xml = false;
1600
1601     gdbserver_state = s;
1602 }
1603
1604 static int gdbserver_open(int port)
1605 {
1606     struct sockaddr_in sockaddr;
1607     int fd, ret;
1608
1609     fd = socket(PF_INET, SOCK_STREAM, 0);
1610     if (fd < 0) {
1611         perror("socket");
1612         return -1;
1613     }
1614 #ifndef _WIN32
1615     fcntl(fd, F_SETFD, FD_CLOEXEC);
1616 #endif
1617
1618     socket_set_fast_reuse(fd);
1619
1620     sockaddr.sin_family = AF_INET;
1621     sockaddr.sin_port = htons(port);
1622     sockaddr.sin_addr.s_addr = 0;
1623     ret = bind(fd, (struct sockaddr *)&sockaddr, sizeof(sockaddr));
1624     if (ret < 0) {
1625         perror("bind");
1626         close(fd);
1627         return -1;
1628     }
1629     ret = listen(fd, 1);
1630     if (ret < 0) {
1631         perror("listen");
1632         close(fd);
1633         return -1;
1634     }
1635     return fd;
1636 }
1637
1638 int gdbserver_start(int port)
1639 {
1640     gdbserver_fd = gdbserver_open(port);
1641     if (gdbserver_fd < 0)
1642         return -1;
1643     /* accept connections */
1644     gdb_accept();
1645     return 0;
1646 }
1647
1648 /* Disable gdb stub for child processes.  */
1649 void gdbserver_fork(CPUState *cpu)
1650 {
1651     GDBState *s = gdbserver_state;
1652
1653     if (gdbserver_fd < 0 || s->fd < 0) {
1654         return;
1655     }
1656     close(s->fd);
1657     s->fd = -1;
1658     cpu_breakpoint_remove_all(cpu, BP_GDB);
1659     cpu_watchpoint_remove_all(cpu, BP_GDB);
1660 }
1661 #else
1662 static int gdb_chr_can_receive(void *opaque)
1663 {
1664   /* We can handle an arbitrarily large amount of data.
1665    Pick the maximum packet size, which is as good as anything.  */
1666   return MAX_PACKET_LENGTH;
1667 }
1668
1669 static void gdb_chr_receive(void *opaque, const uint8_t *buf, int size)
1670 {
1671     int i;
1672
1673     for (i = 0; i < size; i++) {
1674         gdb_read_byte(gdbserver_state, buf[i]);
1675     }
1676 }
1677
1678 static void gdb_chr_event(void *opaque, int event)
1679 {
1680     switch (event) {
1681     case CHR_EVENT_OPENED:
1682         vm_stop(RUN_STATE_PAUSED);
1683         gdb_has_xml = false;
1684         break;
1685     default:
1686         break;
1687     }
1688 }
1689
1690 static void gdb_monitor_output(GDBState *s, const char *msg, int len)
1691 {
1692     char buf[MAX_PACKET_LENGTH];
1693
1694     buf[0] = 'O';
1695     if (len > (MAX_PACKET_LENGTH/2) - 1)
1696         len = (MAX_PACKET_LENGTH/2) - 1;
1697     memtohex(buf + 1, (uint8_t *)msg, len);
1698     put_packet(s, buf);
1699 }
1700
1701 static int gdb_monitor_write(CharDriverState *chr, const uint8_t *buf, int len)
1702 {
1703     const char *p = (const char *)buf;
1704     int max_sz;
1705
1706     max_sz = (sizeof(gdbserver_state->last_packet) - 2) / 2;
1707     for (;;) {
1708         if (len <= max_sz) {
1709             gdb_monitor_output(gdbserver_state, p, len);
1710             break;
1711         }
1712         gdb_monitor_output(gdbserver_state, p, max_sz);
1713         p += max_sz;
1714         len -= max_sz;
1715     }
1716     return len;
1717 }
1718
1719 #ifndef _WIN32
1720 static void gdb_sigterm_handler(int signal)
1721 {
1722     if (runstate_is_running()) {
1723         vm_stop(RUN_STATE_PAUSED);
1724     }
1725 }
1726 #endif
1727
1728 int gdbserver_start(const char *device)
1729 {
1730     GDBState *s;
1731     char gdbstub_device_name[128];
1732     CharDriverState *chr = NULL;
1733     CharDriverState *mon_chr;
1734     ChardevCommon common = { 0 };
1735
1736     if (!first_cpu) {
1737         error_report("gdbstub: meaningless to attach gdb to a "
1738                      "machine without any CPU.");
1739         return -1;
1740     }
1741
1742     if (!device)
1743         return -1;
1744     if (strcmp(device, "none") != 0) {
1745         if (strstart(device, "tcp:", NULL)) {
1746             /* enforce required TCP attributes */
1747             snprintf(gdbstub_device_name, sizeof(gdbstub_device_name),
1748                      "%s,nowait,nodelay,server", device);
1749             device = gdbstub_device_name;
1750         }
1751 #ifndef _WIN32
1752         else if (strcmp(device, "stdio") == 0) {
1753             struct sigaction act;
1754
1755             memset(&act, 0, sizeof(act));
1756             act.sa_handler = gdb_sigterm_handler;
1757             sigaction(SIGINT, &act, NULL);
1758         }
1759 #endif
1760         chr = qemu_chr_new_noreplay("gdb", device);
1761         if (!chr)
1762             return -1;
1763     }
1764
1765     s = gdbserver_state;
1766     if (!s) {
1767         s = g_malloc0(sizeof(GDBState));
1768         gdbserver_state = s;
1769
1770         qemu_add_vm_change_state_handler(gdb_vm_state_change, NULL);
1771
1772         /* Initialize a monitor terminal for gdb */
1773         mon_chr = qemu_chr_alloc(&common, &error_abort);
1774         mon_chr->chr_write = gdb_monitor_write;
1775         monitor_init(mon_chr, 0);
1776     } else {
1777         if (qemu_chr_fe_get_driver(&s->chr)) {
1778             qemu_chr_delete(qemu_chr_fe_get_driver(&s->chr));
1779         }
1780         mon_chr = s->mon_chr;
1781         memset(s, 0, sizeof(GDBState));
1782         s->mon_chr = mon_chr;
1783     }
1784     s->c_cpu = first_cpu;
1785     s->g_cpu = first_cpu;
1786     if (chr) {
1787         qemu_chr_fe_init(&s->chr, chr, &error_abort);
1788         qemu_chr_fe_set_handlers(&s->chr, gdb_chr_can_receive, gdb_chr_receive,
1789                                  gdb_chr_event, NULL, NULL, true);
1790     }
1791     s->state = chr ? RS_IDLE : RS_INACTIVE;
1792     s->mon_chr = mon_chr;
1793     s->current_syscall_cb = NULL;
1794
1795     return 0;
1796 }
1797 #endif