gdbstub/gdbstub.c

   1 /*
   2  * gdb server stub
   3  *
   4  * This implements a subset of the remote protocol as described in:
   5  *
   6  *   https://sourceware.org/gdb/onlinedocs/gdb/Remote-Protocol.html
   7  *
   8  * Copyright (c) 2003-2005 Fabrice Bellard
   9  *
  10  * This library is free software; you can redistribute it and/or
  11  * modify it under the terms of the GNU Lesser General Public
  12  * License as published by the Free Software Foundation; either
  13  * version 2 of the License, or (at your option) any later version.
  14  *
  15  * This library is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  18  * Lesser General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU Lesser General Public
  21  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
  22  *
  23  * SPDX-License-Identifier: LGPL-2.0+
  24  */
  25
  26 #include "qemu/osdep.h"
  27 #include "qemu/ctype.h"
  28 #include "qemu/cutils.h"
  29 #include "qemu/module.h"
  30 #include "qemu/error-report.h"
  31 #include "trace.h"
  32 #include "exec/gdbstub.h"
  33 #include "gdbstub/syscalls.h"
  34 #ifdef CONFIG_USER_ONLY
  35 #include "gdbstub/user.h"
  36 #else
  37 #include "hw/cpu/cluster.h"
  38 #include "hw/boards.h"
  39 #endif
  40
  41 #include "sysemu/hw_accel.h"
  42 #include "sysemu/runstate.h"
  43 #include "exec/replay-core.h"
  44 #include "exec/hwaddr.h"
  45
  46 #include "internals.h"
  47
  48 typedef struct GDBRegisterState {
  49     int base_reg;
  50     int num_regs;
  51     gdb_get_reg_cb get_reg;
  52     gdb_set_reg_cb set_reg;
  53     const char *xml;
  54 } GDBRegisterState;
  55
  56 GDBState gdbserver_state;
  57
  58 void gdb_init_gdbserver_state(void)
  59 {
  60     g_assert(!gdbserver_state.init);
  61     memset(&gdbserver_state, 0, sizeof(GDBState));
  62     gdbserver_state.init = true;
  63     gdbserver_state.str_buf = g_string_new(NULL);
  64     gdbserver_state.mem_buf = g_byte_array_sized_new(MAX_PACKET_LENGTH);
  65     gdbserver_state.last_packet = g_byte_array_sized_new(MAX_PACKET_LENGTH + 4);
  66
  67     /*
  68      * What single-step modes are supported is accelerator dependent.
  69      * By default try to use no IRQs and no timers while single
  70      * stepping so as to make single stepping like a typical ICE HW step.
  71      */
  72     gdbserver_state.supported_sstep_flags = accel_supported_gdbstub_sstep_flags();
  73     gdbserver_state.sstep_flags = SSTEP_ENABLE | SSTEP_NOIRQ | SSTEP_NOTIMER;
  74     gdbserver_state.sstep_flags &= gdbserver_state.supported_sstep_flags;
  75 }
  76
  77 /* writes 2*len+1 bytes in buf */
  78 void gdb_memtohex(GString *buf, const uint8_t *mem, int len)
  79 {
  80     int i, c;
  81     for(i = 0; i < len; i++) {
  82         c = mem[i];
  83         g_string_append_c(buf, tohex(c >> 4));
  84         g_string_append_c(buf, tohex(c & 0xf));
  85     }
  86     g_string_append_c(buf, '\0');
  87 }
  88
  89 void gdb_hextomem(GByteArray *mem, const char *buf, int len)
  90 {
  91     int i;
  92
  93     for(i = 0; i < len; i++) {
  94         guint8 byte = fromhex(buf[0]) << 4 | fromhex(buf[1]);
  95         g_byte_array_append(mem, &byte, 1);
  96         buf += 2;
  97     }
  98 }
  99
 100 static void hexdump(const char *buf, int len,
 101                     void (*trace_fn)(size_t ofs, char const *text))
 102 {
 103     char line_buffer[3 * 16 + 4 + 16 + 1];
 104
 105     size_t i;
 106     for (i = 0; i < len || (i & 0xF); ++i) {
 107         size_t byte_ofs = i & 15;
 108
 109         if (byte_ofs == 0) {
 110             memset(line_buffer, ' ', 3 * 16 + 4 + 16);
 111             line_buffer[3 * 16 + 4 + 16] = 0;
 112         }
 113
 114         size_t col_group = (i >> 2) & 3;
 115         size_t hex_col = byte_ofs * 3 + col_group;
 116         size_t txt_col = 3 * 16 + 4 + byte_ofs;
 117
 118         if (i < len) {
 119             char value = buf[i];
 120
 121             line_buffer[hex_col + 0] = tohex((value >> 4) & 0xF);
 122             line_buffer[hex_col + 1] = tohex((value >> 0) & 0xF);
 123             line_buffer[txt_col + 0] = (value >= ' ' && value < 127)
 124                     ? value
 125                     : '.';
 126         }
 127
 128         if (byte_ofs == 0xF)
 129             trace_fn(i & -16, line_buffer);
 130     }
 131 }
 132
 133 /* return -1 if error, 0 if OK */
 134 int gdb_put_packet_binary(const char *buf, int len, bool dump)
 135 {
 136     int csum, i;
 137     uint8_t footer[3];
 138
 139     if (dump && trace_event_get_state_backends(TRACE_GDBSTUB_IO_BINARYREPLY)) {
 140         hexdump(buf, len, trace_gdbstub_io_binaryreply);
 141     }
 142
 143     for(;;) {
 144         g_byte_array_set_size(gdbserver_state.last_packet, 0);
 145         g_byte_array_append(gdbserver_state.last_packet,
 146                             (const uint8_t *) "$", 1);
 147         g_byte_array_append(gdbserver_state.last_packet,
 148                             (const uint8_t *) buf, len);
 149         csum = 0;
 150         for(i = 0; i < len; i++) {
 151             csum += buf[i];
 152         }
 153         footer[0] = '#';
 154         footer[1] = tohex((csum >> 4) & 0xf);
 155         footer[2] = tohex((csum) & 0xf);
 156         g_byte_array_append(gdbserver_state.last_packet, footer, 3);
 157
 158         gdb_put_buffer(gdbserver_state.last_packet->data,
 159                    gdbserver_state.last_packet->len);
 160
 161         if (gdb_got_immediate_ack()) {
 162             break;
 163         }
 164     }
 165     return 0;
 166 }
 167
 168 /* return -1 if error, 0 if OK */
 169 int gdb_put_packet(const char *buf)
 170 {
 171     trace_gdbstub_io_reply(buf);
 172
 173     return gdb_put_packet_binary(buf, strlen(buf), false);
 174 }
 175
 176 void gdb_put_strbuf(void)
 177 {
 178     gdb_put_packet(gdbserver_state.str_buf->str);
 179 }
 180
 181 /* Encode data using the encoding for 'x' packets.  */
 182 void gdb_memtox(GString *buf, const char *mem, int len)
 183 {
 184     char c;
 185
 186     while (len--) {
 187         c = *(mem++);
 188         switch (c) {
 189         case '#': case '$': case '*': case '}':
 190             g_string_append_c(buf, '}');
 191             g_string_append_c(buf, c ^ 0x20);
 192             break;
 193         default:
 194             g_string_append_c(buf, c);
 195             break;
 196         }
 197     }
 198 }
 199
 200 static uint32_t gdb_get_cpu_pid(CPUState *cpu)
 201 {
 202 #ifdef CONFIG_USER_ONLY
 203     return getpid();
 204 #else
 205     if (cpu->cluster_index == UNASSIGNED_CLUSTER_INDEX) {
 206         /* Return the default process' PID */
 207         int index = gdbserver_state.process_num - 1;
 208         return gdbserver_state.processes[index].pid;
 209     }
 210     return cpu->cluster_index + 1;
 211 #endif
 212 }
 213
 214 GDBProcess *gdb_get_process(uint32_t pid)
 215 {
 216     int i;
 217
 218     if (!pid) {
 219         /* 0 means any process, we take the first one */
 220         return &gdbserver_state.processes[0];
 221     }
 222
 223     for (i = 0; i < gdbserver_state.process_num; i++) {
 224         if (gdbserver_state.processes[i].pid == pid) {
 225             return &gdbserver_state.processes[i];
 226         }
 227     }
 228
 229     return NULL;
 230 }
 231
 232 static GDBProcess *gdb_get_cpu_process(CPUState *cpu)
 233 {
 234     return gdb_get_process(gdb_get_cpu_pid(cpu));
 235 }
 236
 237 static CPUState *find_cpu(uint32_t thread_id)
 238 {
 239     CPUState *cpu;
 240
 241     CPU_FOREACH(cpu) {
 242         if (gdb_get_cpu_index(cpu) == thread_id) {
 243             return cpu;
 244         }
 245     }
 246
 247     return NULL;
 248 }
 249
 250 CPUState *gdb_get_first_cpu_in_process(GDBProcess *process)
 251 {
 252     CPUState *cpu;
 253
 254     CPU_FOREACH(cpu) {
 255         if (gdb_get_cpu_pid(cpu) == process->pid) {
 256             return cpu;
 257         }
 258     }
 259
 260     return NULL;
 261 }
 262
 263 static CPUState *gdb_next_cpu_in_process(CPUState *cpu)
 264 {
 265     uint32_t pid = gdb_get_cpu_pid(cpu);
 266     cpu = CPU_NEXT(cpu);
 267
 268     while (cpu) {
 269         if (gdb_get_cpu_pid(cpu) == pid) {
 270             break;
 271         }
 272
 273         cpu = CPU_NEXT(cpu);
 274     }
 275
 276     return cpu;
 277 }
 278
 279 /* Return the cpu following @cpu, while ignoring unattached processes. */
 280 static CPUState *gdb_next_attached_cpu(CPUState *cpu)
 281 {
 282     cpu = CPU_NEXT(cpu);
 283
 284     while (cpu) {
 285         if (gdb_get_cpu_process(cpu)->attached) {
 286             break;
 287         }
 288
 289         cpu = CPU_NEXT(cpu);
 290     }
 291
 292     return cpu;
 293 }
 294
 295 /* Return the first attached cpu */
 296 CPUState *gdb_first_attached_cpu(void)
 297 {
 298     CPUState *cpu = first_cpu;
 299     GDBProcess *process = gdb_get_cpu_process(cpu);
 300
 301     if (!process->attached) {
 302         return gdb_next_attached_cpu(cpu);
 303     }
 304
 305     return cpu;
 306 }
 307
 308 static CPUState *gdb_get_cpu(uint32_t pid, uint32_t tid)
 309 {
 310     GDBProcess *process;
 311     CPUState *cpu;
 312
 313     if (!pid && !tid) {
 314         /* 0 means any process/thread, we take the first attached one */
 315         return gdb_first_attached_cpu();
 316     } else if (pid && !tid) {
 317         /* any thread in a specific process */
 318         process = gdb_get_process(pid);
 319
 320         if (process == NULL) {
 321             return NULL;
 322         }
 323
 324         if (!process->attached) {
 325             return NULL;
 326         }
 327
 328         return gdb_get_first_cpu_in_process(process);
 329     } else {
 330         /* a specific thread */
 331         cpu = find_cpu(tid);
 332
 333         if (cpu == NULL) {
 334             return NULL;
 335         }
 336
 337         process = gdb_get_cpu_process(cpu);
 338
 339         if (pid && process->pid != pid) {
 340             return NULL;
 341         }
 342
 343         if (!process->attached) {
 344             return NULL;
 345         }
 346
 347         return cpu;
 348     }
 349 }
 350
 351 static const char *get_feature_xml(const char *p, const char **newp,
 352                                    GDBProcess *process)
 353 {
 354     CPUState *cpu = gdb_get_first_cpu_in_process(process);
 355     CPUClass *cc = CPU_GET_CLASS(cpu);
 356     size_t len;
 357
 358     /*
 359      * qXfer:features:read:ANNEX:OFFSET,LENGTH'
 360      *                     ^p    ^newp
 361      */
 362     char *term = strchr(p, ':');
 363     *newp = term + 1;
 364     len = term - p;
 365
 366     /* Is it the main target xml? */
 367     if (strncmp(p, "target.xml", len) == 0) {
 368         if (!process->target_xml) {
 369             GDBRegisterState *r;
 370             g_autoptr(GPtrArray) xml = g_ptr_array_new_with_free_func(g_free);
 371
 372             g_ptr_array_add(
 373                 xml,
 374                 g_strdup("<?xml version=\"1.0\"?>"
 375                          "<!DOCTYPE target SYSTEM \"gdb-target.dtd\">"
 376                          "<target>"));
 377
 378             if (cc->gdb_arch_name) {
 379                 g_ptr_array_add(
 380                     xml,
 381                     g_markup_printf_escaped("<architecture>%s</architecture>",
 382                                             cc->gdb_arch_name(cpu)));
 383             }
 384             g_ptr_array_add(
 385                 xml,
 386                 g_markup_printf_escaped("<xi:include href=\"%s\"/>",
 387                                         cc->gdb_core_xml_file));
 388             if (cpu->gdb_regs) {
 389                 for (guint i = 0; i < cpu->gdb_regs->len; i++) {
 390                     r = &g_array_index(cpu->gdb_regs, GDBRegisterState, i);
 391                     g_ptr_array_add(
 392                         xml,
 393                         g_markup_printf_escaped("<xi:include href=\"%s\"/>",
 394                                                 r->xml));
 395                 }
 396             }
 397             g_ptr_array_add(xml, g_strdup("</target>"));
 398             g_ptr_array_add(xml, NULL);
 399
 400             process->target_xml = g_strjoinv(NULL, (void *)xml->pdata);
 401         }
 402         return process->target_xml;
 403     }
 404     /* Is it dynamically generated by the target? */
 405     if (cc->gdb_get_dynamic_xml) {
 406         g_autofree char *xmlname = g_strndup(p, len);
 407         const char *xml = cc->gdb_get_dynamic_xml(cpu, xmlname);
 408         if (xml) {
 409             return xml;
 410         }
 411     }
 412     /* Is it one of the encoded gdb-xml/ files? */
 413     for (int i = 0; gdb_static_features[i].xmlname; i++) {
 414         const char *name = gdb_static_features[i].xmlname;
 415         if ((strncmp(name, p, len) == 0) &&
 416             strlen(name) == len) {
 417             return gdb_static_features[i].xml;
 418         }
 419     }
 420
 421     /* failed */
 422     return NULL;
 423 }
 424
 425 void gdb_feature_builder_init(GDBFeatureBuilder *builder, GDBFeature *feature,
 426                               const char *name, const char *xmlname,
 427                               int base_reg)
 428 {
 429     char *header = g_markup_printf_escaped(
 430         "<?xml version=\"1.0\"?>"
 431         "<!DOCTYPE feature SYSTEM \"gdb-target.dtd\">"
 432         "<feature name=\"%s\">",
 433         name);
 434
 435     builder->feature = feature;
 436     builder->xml = g_ptr_array_new();
 437     g_ptr_array_add(builder->xml, header);
 438     builder->base_reg = base_reg;
 439     feature->xmlname = xmlname;
 440     feature->num_regs = 0;
 441 }
 442
 443 void gdb_feature_builder_append_tag(const GDBFeatureBuilder *builder,
 444                                     const char *format, ...)
 445 {
 446     va_list ap;
 447     va_start(ap, format);
 448     g_ptr_array_add(builder->xml, g_markup_vprintf_escaped(format, ap));
 449     va_end(ap);
 450 }
 451
 452 void gdb_feature_builder_append_reg(const GDBFeatureBuilder *builder,
 453                                     const char *name,
 454                                     int bitsize,
 455                                     int regnum,
 456                                     const char *type,
 457                                     const char *group)
 458 {
 459     if (builder->feature->num_regs < regnum) {
 460         builder->feature->num_regs = regnum;
 461     }
 462
 463     if (group) {
 464         gdb_feature_builder_append_tag(
 465             builder,
 466             "<reg name=\"%s\" bitsize=\"%d\" regnum=\"%d\" type=\"%s\" group=\"%s\"/>",
 467             name, bitsize, builder->base_reg + regnum, type, group);
 468     } else {
 469         gdb_feature_builder_append_tag(
 470             builder,
 471             "<reg name=\"%s\" bitsize=\"%d\" regnum=\"%d\" type=\"%s\"/>",
 472             name, bitsize, builder->base_reg + regnum, type);
 473     }
 474 }
 475
 476 void gdb_feature_builder_end(const GDBFeatureBuilder *builder)
 477 {
 478     g_ptr_array_add(builder->xml, (void *)"</feature>");
 479     g_ptr_array_add(builder->xml, NULL);
 480
 481     builder->feature->xml = g_strjoinv(NULL, (void *)builder->xml->pdata);
 482
 483     for (guint i = 0; i < builder->xml->len - 2; i++) {
 484         g_free(g_ptr_array_index(builder->xml, i));
 485     }
 486
 487     g_ptr_array_free(builder->xml, TRUE);
 488 }
 489
 490 const GDBFeature *gdb_find_static_feature(const char *xmlname)
 491 {
 492     const GDBFeature *feature;
 493
 494     for (feature = gdb_static_features; feature->xmlname; feature++) {
 495         if (!strcmp(feature->xmlname, xmlname)) {
 496             return feature;
 497         }
 498     }
 499
 500     g_assert_not_reached();
 501 }
 502
 503 static int gdb_read_register(CPUState *cpu, GByteArray *buf, int reg)
 504 {
 505     CPUClass *cc = CPU_GET_CLASS(cpu);
 506     CPUArchState *env = cpu_env(cpu);
 507     GDBRegisterState *r;
 508
 509     if (reg < cc->gdb_num_core_regs) {
 510         return cc->gdb_read_register(cpu, buf, reg);
 511     }
 512
 513     if (cpu->gdb_regs) {
 514         for (guint i = 0; i < cpu->gdb_regs->len; i++) {
 515             r = &g_array_index(cpu->gdb_regs, GDBRegisterState, i);
 516             if (r->base_reg <= reg && reg < r->base_reg + r->num_regs) {
 517                 return r->get_reg(env, buf, reg - r->base_reg);
 518             }
 519         }
 520     }
 521     return 0;
 522 }
 523
 524 static int gdb_write_register(CPUState *cpu, uint8_t *mem_buf, int reg)
 525 {
 526     CPUClass *cc = CPU_GET_CLASS(cpu);
 527     CPUArchState *env = cpu_env(cpu);
 528     GDBRegisterState *r;
 529
 530     if (reg < cc->gdb_num_core_regs) {
 531         return cc->gdb_write_register(cpu, mem_buf, reg);
 532     }
 533
 534     if (cpu->gdb_regs) {
 535         for (guint i = 0; i < cpu->gdb_regs->len; i++) {
 536             r =  &g_array_index(cpu->gdb_regs, GDBRegisterState, i);
 537             if (r->base_reg <= reg && reg < r->base_reg + r->num_regs) {
 538                 return r->set_reg(env, mem_buf, reg - r->base_reg);
 539             }
 540         }
 541     }
 542     return 0;
 543 }
 544
 545 void gdb_register_coprocessor(CPUState *cpu,
 546                               gdb_get_reg_cb get_reg, gdb_set_reg_cb set_reg,
 547                               int num_regs, const char *xml, int g_pos)
 548 {
 549     GDBRegisterState *s;
 550     guint i;
 551
 552     if (cpu->gdb_regs) {
 553         for (i = 0; i < cpu->gdb_regs->len; i++) {
 554             /* Check for duplicates.  */
 555             s = &g_array_index(cpu->gdb_regs, GDBRegisterState, i);
 556             if (strcmp(s->xml, xml) == 0) {
 557                 return;
 558             }
 559         }
 560     } else {
 561         cpu->gdb_regs = g_array_new(false, false, sizeof(GDBRegisterState));
 562         i = 0;
 563     }
 564
 565     g_array_set_size(cpu->gdb_regs, i + 1);
 566     s = &g_array_index(cpu->gdb_regs, GDBRegisterState, i);
 567     s->base_reg = cpu->gdb_num_regs;
 568     s->num_regs = num_regs;
 569     s->get_reg = get_reg;
 570     s->set_reg = set_reg;
 571     s->xml = xml;
 572
 573     /* Add to end of list.  */
 574     cpu->gdb_num_regs += num_regs;
 575     if (g_pos) {
 576         if (g_pos != s->base_reg) {
 577             error_report("Error: Bad gdb register numbering for '%s', "
 578                          "expected %d got %d", xml, g_pos, s->base_reg);
 579         } else {
 580             cpu->gdb_num_g_regs = cpu->gdb_num_regs;
 581         }
 582     }
 583 }
 584
 585 static void gdb_process_breakpoint_remove_all(GDBProcess *p)
 586 {
 587     CPUState *cpu = gdb_get_first_cpu_in_process(p);
 588
 589     while (cpu) {
 590         gdb_breakpoint_remove_all(cpu);
 591         cpu = gdb_next_cpu_in_process(cpu);
 592     }
 593 }
 594
 595
 596 static void gdb_set_cpu_pc(vaddr pc)
 597 {
 598     CPUState *cpu = gdbserver_state.c_cpu;
 599
 600     cpu_synchronize_state(cpu);
 601     cpu_set_pc(cpu, pc);
 602 }
 603
 604 void gdb_append_thread_id(CPUState *cpu, GString *buf)
 605 {
 606     if (gdbserver_state.multiprocess) {
 607         g_string_append_printf(buf, "p%02x.%02x",
 608                                gdb_get_cpu_pid(cpu), gdb_get_cpu_index(cpu));
 609     } else {
 610         g_string_append_printf(buf, "%02x", gdb_get_cpu_index(cpu));
 611     }
 612 }
 613
 614 static GDBThreadIdKind read_thread_id(const char *buf, const char **end_buf,
 615                                       uint32_t *pid, uint32_t *tid)
 616 {
 617     unsigned long p, t;
 618     int ret;
 619
 620     if (*buf == 'p') {
 621         buf++;
 622         ret = qemu_strtoul(buf, &buf, 16, &p);
 623
 624         if (ret) {
 625             return GDB_READ_THREAD_ERR;
 626         }
 627
 628         /* Skip '.' */
 629         buf++;
 630     } else {
 631         p = 0;
 632     }
 633
 634     ret = qemu_strtoul(buf, &buf, 16, &t);
 635
 636     if (ret) {
 637         return GDB_READ_THREAD_ERR;
 638     }
 639
 640     *end_buf = buf;
 641
 642     if (p == -1) {
 643         return GDB_ALL_PROCESSES;
 644     }
 645
 646     if (pid) {
 647         *pid = p;
 648     }
 649
 650     if (t == -1) {
 651         return GDB_ALL_THREADS;
 652     }
 653
 654     if (tid) {
 655         *tid = t;
 656     }
 657
 658     return GDB_ONE_THREAD;
 659 }
 660
 661 /**
 662  * gdb_handle_vcont - Parses and handles a vCont packet.
 663  * returns -ENOTSUP if a command is unsupported, -EINVAL or -ERANGE if there is
 664  *         a format error, 0 on success.
 665  */
 666 static int gdb_handle_vcont(const char *p)
 667 {
 668     int res, signal = 0;
 669     char cur_action;
 670     unsigned long tmp;
 671     uint32_t pid, tid;
 672     GDBProcess *process;
 673     CPUState *cpu;
 674     GDBThreadIdKind kind;
 675     unsigned int max_cpus = gdb_get_max_cpus();
 676     /* uninitialised CPUs stay 0 */
 677     g_autofree char *newstates = g_new0(char, max_cpus);
 678
 679     /* mark valid CPUs with 1 */
 680     CPU_FOREACH(cpu) {
 681         newstates[cpu->cpu_index] = 1;
 682     }
 683
 684     /*
 685      * res keeps track of what error we are returning, with -ENOTSUP meaning
 686      * that the command is unknown or unsupported, thus returning an empty
 687      * packet, while -EINVAL and -ERANGE cause an E22 packet, due to invalid,
 688      *  or incorrect parameters passed.
 689      */
 690     res = 0;
 691
 692     /*
 693      * target_count and last_target keep track of how many CPUs we are going to
 694      * step or resume, and a pointer to the state structure of one of them,
 695      * respectively
 696      */
 697     int target_count = 0;
 698     CPUState *last_target = NULL;
 699
 700     while (*p) {
 701         if (*p++ != ';') {
 702             return -ENOTSUP;
 703         }
 704
 705         cur_action = *p++;
 706         if (cur_action == 'C' || cur_action == 'S') {
 707             cur_action = qemu_tolower(cur_action);
 708             res = qemu_strtoul(p, &p, 16, &tmp);
 709             if (res) {
 710                 return res;
 711             }
 712             signal = gdb_signal_to_target(tmp);
 713         } else if (cur_action != 'c' && cur_action != 's') {
 714             /* unknown/invalid/unsupported command */
 715             return -ENOTSUP;
 716         }
 717
 718         if (*p == '\0' || *p == ';') {
 719             /*
 720              * No thread specifier, action is on "all threads". The
 721              * specification is unclear regarding the process to act on. We
 722              * choose all processes.
 723              */
 724             kind = GDB_ALL_PROCESSES;
 725         } else if (*p++ == ':') {
 726             kind = read_thread_id(p, &p, &pid, &tid);
 727         } else {
 728             return -ENOTSUP;
 729         }
 730
 731         switch (kind) {
 732         case GDB_READ_THREAD_ERR:
 733             return -EINVAL;
 734
 735         case GDB_ALL_PROCESSES:
 736             cpu = gdb_first_attached_cpu();
 737             while (cpu) {
 738                 if (newstates[cpu->cpu_index] == 1) {
 739                     newstates[cpu->cpu_index] = cur_action;
 740
 741                     target_count++;
 742                     last_target = cpu;
 743                 }
 744
 745                 cpu = gdb_next_attached_cpu(cpu);
 746             }
 747             break;
 748
 749         case GDB_ALL_THREADS:
 750             process = gdb_get_process(pid);
 751
 752             if (!process->attached) {
 753                 return -EINVAL;
 754             }
 755
 756             cpu = gdb_get_first_cpu_in_process(process);
 757             while (cpu) {
 758                 if (newstates[cpu->cpu_index] == 1) {
 759                     newstates[cpu->cpu_index] = cur_action;
 760
 761                     target_count++;
 762                     last_target = cpu;
 763                 }
 764
 765                 cpu = gdb_next_cpu_in_process(cpu);
 766             }
 767             break;
 768
 769         case GDB_ONE_THREAD:
 770             cpu = gdb_get_cpu(pid, tid);
 771
 772             /* invalid CPU/thread specified */
 773             if (!cpu) {
 774                 return -EINVAL;
 775             }
 776
 777             /* only use if no previous match occourred */
 778             if (newstates[cpu->cpu_index] == 1) {
 779                 newstates[cpu->cpu_index] = cur_action;
 780
 781                 target_count++;
 782                 last_target = cpu;
 783             }
 784             break;
 785         }
 786     }
 787
 788     /*
 789      * if we're about to resume a specific set of CPUs/threads, make it so that
 790      * in case execution gets interrupted, we can send GDB a stop reply with a
 791      * correct value. it doesn't really matter which CPU we tell GDB the signal
 792      * happened in (VM pauses stop all of them anyway), so long as it is one of
 793      * the ones we resumed/single stepped here.
 794      */
 795     if (target_count > 0) {
 796         gdbserver_state.c_cpu = last_target;
 797     }
 798
 799     gdbserver_state.signal = signal;
 800     gdb_continue_partial(newstates);
 801     return res;
 802 }
 803
 804 static const char *cmd_next_param(const char *param, const char delimiter)
 805 {
 806     static const char all_delimiters[] = ",;:=";
 807     char curr_delimiters[2] = {0};
 808     const char *delimiters;
 809
 810     if (delimiter == '?') {
 811         delimiters = all_delimiters;
 812     } else if (delimiter == '0') {
 813         return strchr(param, '\0');
 814     } else if (delimiter == '.' && *param) {
 815         return param + 1;
 816     } else {
 817         curr_delimiters[0] = delimiter;
 818         delimiters = curr_delimiters;
 819     }
 820
 821     param += strcspn(param, delimiters);
 822     if (*param) {
 823         param++;
 824     }
 825     return param;
 826 }
 827
 828 static int cmd_parse_params(const char *data, const char *schema,
 829                             GArray *params)
 830 {
 831     const char *curr_schema, *curr_data;
 832
 833     g_assert(schema);
 834     g_assert(params->len == 0);
 835
 836     curr_schema = schema;
 837     curr_data = data;
 838     while (curr_schema[0] && curr_schema[1] && *curr_data) {
 839         GdbCmdVariant this_param;
 840
 841         switch (curr_schema[0]) {
 842         case 'l':
 843             if (qemu_strtoul(curr_data, &curr_data, 16,
 844                              &this_param.val_ul)) {
 845                 return -EINVAL;
 846             }
 847             curr_data = cmd_next_param(curr_data, curr_schema[1]);
 848             g_array_append_val(params, this_param);
 849             break;
 850         case 'L':
 851             if (qemu_strtou64(curr_data, &curr_data, 16,
 852                               (uint64_t *)&this_param.val_ull)) {
 853                 return -EINVAL;
 854             }
 855             curr_data = cmd_next_param(curr_data, curr_schema[1]);
 856             g_array_append_val(params, this_param);
 857             break;
 858         case 's':
 859             this_param.data = curr_data;
 860             curr_data = cmd_next_param(curr_data, curr_schema[1]);
 861             g_array_append_val(params, this_param);
 862             break;
 863         case 'o':
 864             this_param.opcode = *(uint8_t *)curr_data;
 865             curr_data = cmd_next_param(curr_data, curr_schema[1]);
 866             g_array_append_val(params, this_param);
 867             break;
 868         case 't':
 869             this_param.thread_id.kind =
 870                 read_thread_id(curr_data, &curr_data,
 871                                &this_param.thread_id.pid,
 872                                &this_param.thread_id.tid);
 873             curr_data = cmd_next_param(curr_data, curr_schema[1]);
 874             g_array_append_val(params, this_param);
 875             break;
 876         case '?':
 877             curr_data = cmd_next_param(curr_data, curr_schema[1]);
 878             break;
 879         default:
 880             return -EINVAL;
 881         }
 882         curr_schema += 2;
 883     }
 884
 885     return 0;
 886 }
 887
 888 typedef void (*GdbCmdHandler)(GArray *params, void *user_ctx);
 889
 890 /*
 891  * cmd_startswith -> cmd is compared using startswith
 892  *
 893  * allow_stop_reply -> true iff the gdbstub can respond to this command with a
 894  *   "stop reply" packet. The list of commands that accept such response is
 895  *   defined at the GDB Remote Serial Protocol documentation. see:
 896  *   https://sourceware.org/gdb/onlinedocs/gdb/Stop-Reply-Packets.html#Stop-Reply-Packets.
 897  *
 898  * schema definitions:
 899  * Each schema parameter entry consists of 2 chars,
 900  * the first char represents the parameter type handling
 901  * the second char represents the delimiter for the next parameter
 902  *
 903  * Currently supported schema types:
 904  * 'l' -> unsigned long (stored in .val_ul)
 905  * 'L' -> unsigned long long (stored in .val_ull)
 906  * 's' -> string (stored in .data)
 907  * 'o' -> single char (stored in .opcode)
 908  * 't' -> thread id (stored in .thread_id)
 909  * '?' -> skip according to delimiter
 910  *
 911  * Currently supported delimiters:
 912  * '?' -> Stop at any delimiter (",;:=\0")
 913  * '0' -> Stop at "\0"
 914  * '.' -> Skip 1 char unless reached "\0"
 915  * Any other value is treated as the delimiter value itself
 916  */
 917 typedef struct GdbCmdParseEntry {
 918     GdbCmdHandler handler;
 919     const char *cmd;
 920     bool cmd_startswith;
 921     const char *schema;
 922     bool allow_stop_reply;
 923 } GdbCmdParseEntry;
 924
 925 static inline int startswith(const char *string, const char *pattern)
 926 {
 927   return !strncmp(string, pattern, strlen(pattern));
 928 }
 929
 930 static int process_string_cmd(const char *data,
 931                               const GdbCmdParseEntry *cmds, int num_cmds)
 932 {
 933     int i;
 934     g_autoptr(GArray) params = g_array_new(false, true, sizeof(GdbCmdVariant));
 935
 936     if (!cmds) {
 937         return -1;
 938     }
 939
 940     for (i = 0; i < num_cmds; i++) {
 941         const GdbCmdParseEntry *cmd = &cmds[i];
 942         g_assert(cmd->handler && cmd->cmd);
 943
 944         if ((cmd->cmd_startswith && !startswith(data, cmd->cmd)) ||
 945             (!cmd->cmd_startswith && strcmp(cmd->cmd, data))) {
 946             continue;
 947         }
 948
 949         if (cmd->schema) {
 950             if (cmd_parse_params(&data[strlen(cmd->cmd)],
 951                                  cmd->schema, params)) {
 952                 return -1;
 953             }
 954         }
 955
 956         gdbserver_state.allow_stop_reply = cmd->allow_stop_reply;
 957         cmd->handler(params, NULL);
 958         return 0;
 959     }
 960
 961     return -1;
 962 }
 963
 964 static void run_cmd_parser(const char *data, const GdbCmdParseEntry *cmd)
 965 {
 966     if (!data) {
 967         return;
 968     }
 969
 970     g_string_set_size(gdbserver_state.str_buf, 0);
 971     g_byte_array_set_size(gdbserver_state.mem_buf, 0);
 972
 973     /* In case there was an error during the command parsing we must
 974     * send a NULL packet to indicate the command is not supported */
 975     if (process_string_cmd(data, cmd, 1)) {
 976         gdb_put_packet("");
 977     }
 978 }
 979
 980 static void handle_detach(GArray *params, void *user_ctx)
 981 {
 982     GDBProcess *process;
 983     uint32_t pid = 1;
 984
 985     if (gdbserver_state.multiprocess) {
 986         if (!params->len) {
 987             gdb_put_packet("E22");
 988             return;
 989         }
 990
 991         pid = get_param(params, 0)->val_ul;
 992     }
 993
 994     process = gdb_get_process(pid);
 995     gdb_process_breakpoint_remove_all(process);
 996     process->attached = false;
 997
 998     if (pid == gdb_get_cpu_pid(gdbserver_state.c_cpu)) {
 999         gdbserver_state.c_cpu = gdb_first_attached_cpu();
1000     }
1001
1002     if (pid == gdb_get_cpu_pid(gdbserver_state.g_cpu)) {
1003         gdbserver_state.g_cpu = gdb_first_attached_cpu();
1004     }
1005
1006     if (!gdbserver_state.c_cpu) {
1007         /* No more process attached */
1008         gdb_disable_syscalls();
1009         gdb_continue();
1010     }
1011     gdb_put_packet("OK");
1012 }
1013
1014 static void handle_thread_alive(GArray *params, void *user_ctx)
1015 {
1016     CPUState *cpu;
1017
1018     if (!params->len) {
1019         gdb_put_packet("E22");
1020         return;
1021     }
1022
1023     if (get_param(params, 0)->thread_id.kind == GDB_READ_THREAD_ERR) {
1024         gdb_put_packet("E22");
1025         return;
1026     }
1027
1028     cpu = gdb_get_cpu(get_param(params, 0)->thread_id.pid,
1029                       get_param(params, 0)->thread_id.tid);
1030     if (!cpu) {
1031         gdb_put_packet("E22");
1032         return;
1033     }
1034
1035     gdb_put_packet("OK");
1036 }
1037
1038 static void handle_continue(GArray *params, void *user_ctx)
1039 {
1040     if (params->len) {
1041         gdb_set_cpu_pc(get_param(params, 0)->val_ull);
1042     }
1043
1044     gdbserver_state.signal = 0;
1045     gdb_continue();
1046 }
1047
1048 static void handle_cont_with_sig(GArray *params, void *user_ctx)
1049 {
1050     unsigned long signal = 0;
1051
1052     /*
1053      * Note: C sig;[addr] is currently unsupported and we simply
1054      *       omit the addr parameter
1055      */
1056     if (params->len) {
1057         signal = get_param(params, 0)->val_ul;
1058     }
1059
1060     gdbserver_state.signal = gdb_signal_to_target(signal);
1061     if (gdbserver_state.signal == -1) {
1062         gdbserver_state.signal = 0;
1063     }
1064     gdb_continue();
1065 }
1066
1067 static void handle_set_thread(GArray *params, void *user_ctx)
1068 {
1069     CPUState *cpu;
1070
1071     if (params->len != 2) {
1072         gdb_put_packet("E22");
1073         return;
1074     }
1075
1076     if (get_param(params, 1)->thread_id.kind == GDB_READ_THREAD_ERR) {
1077         gdb_put_packet("E22");
1078         return;
1079     }
1080
1081     if (get_param(params, 1)->thread_id.kind != GDB_ONE_THREAD) {
1082         gdb_put_packet("OK");
1083         return;
1084     }
1085
1086     cpu = gdb_get_cpu(get_param(params, 1)->thread_id.pid,
1087                       get_param(params, 1)->thread_id.tid);
1088     if (!cpu) {
1089         gdb_put_packet("E22");
1090         return;
1091     }
1092
1093     /*
1094      * Note: This command is deprecated and modern gdb's will be using the
1095      *       vCont command instead.
1096      */
1097     switch (get_param(params, 0)->opcode) {
1098     case 'c':
1099         gdbserver_state.c_cpu = cpu;
1100         gdb_put_packet("OK");
1101         break;
1102     case 'g':
1103         gdbserver_state.g_cpu = cpu;
1104         gdb_put_packet("OK");
1105         break;
1106     default:
1107         gdb_put_packet("E22");
1108         break;
1109     }
1110 }
1111
1112 static void handle_insert_bp(GArray *params, void *user_ctx)
1113 {
1114     int res;
1115
1116     if (params->len != 3) {
1117         gdb_put_packet("E22");
1118         return;
1119     }
1120
1121     res = gdb_breakpoint_insert(gdbserver_state.c_cpu,
1122                                 get_param(params, 0)->val_ul,
1123                                 get_param(params, 1)->val_ull,
1124                                 get_param(params, 2)->val_ull);
1125     if (res >= 0) {
1126         gdb_put_packet("OK");
1127         return;
1128     } else if (res == -ENOSYS) {
1129         gdb_put_packet("");
1130         return;
1131     }
1132
1133     gdb_put_packet("E22");
1134 }
1135
1136 static void handle_remove_bp(GArray *params, void *user_ctx)
1137 {
1138     int res;
1139
1140     if (params->len != 3) {
1141         gdb_put_packet("E22");
1142         return;
1143     }
1144
1145     res = gdb_breakpoint_remove(gdbserver_state.c_cpu,
1146                                 get_param(params, 0)->val_ul,
1147                                 get_param(params, 1)->val_ull,
1148                                 get_param(params, 2)->val_ull);
1149     if (res >= 0) {
1150         gdb_put_packet("OK");
1151         return;
1152     } else if (res == -ENOSYS) {
1153         gdb_put_packet("");
1154         return;
1155     }
1156
1157     gdb_put_packet("E22");
1158 }
1159
1160 /*
1161  * handle_set/get_reg
1162  *
1163  * Older gdb are really dumb, and don't use 'G/g' if 'P/p' is available.
1164  * This works, but can be very slow. Anything new enough to understand
1165  * XML also knows how to use this properly. However to use this we
1166  * need to define a local XML file as well as be talking to a
1167  * reasonably modern gdb. Responding with an empty packet will cause
1168  * the remote gdb to fallback to older methods.
1169  */
1170
1171 static void handle_set_reg(GArray *params, void *user_ctx)
1172 {
1173     int reg_size;
1174
1175     if (params->len != 2) {
1176         gdb_put_packet("E22");
1177         return;
1178     }
1179
1180     reg_size = strlen(get_param(params, 1)->data) / 2;
1181     gdb_hextomem(gdbserver_state.mem_buf, get_param(params, 1)->data, reg_size);
1182     gdb_write_register(gdbserver_state.g_cpu, gdbserver_state.mem_buf->data,
1183                        get_param(params, 0)->val_ull);
1184     gdb_put_packet("OK");
1185 }
1186
1187 static void handle_get_reg(GArray *params, void *user_ctx)
1188 {
1189     int reg_size;
1190
1191     if (!params->len) {
1192         gdb_put_packet("E14");
1193         return;
1194     }
1195
1196     reg_size = gdb_read_register(gdbserver_state.g_cpu,
1197                                  gdbserver_state.mem_buf,
1198                                  get_param(params, 0)->val_ull);
1199     if (!reg_size) {
1200         gdb_put_packet("E14");
1201         return;
1202     } else {
1203         g_byte_array_set_size(gdbserver_state.mem_buf, reg_size);
1204     }
1205
1206     gdb_memtohex(gdbserver_state.str_buf,
1207                  gdbserver_state.mem_buf->data, reg_size);
1208     gdb_put_strbuf();
1209 }
1210
1211 static void handle_write_mem(GArray *params, void *user_ctx)
1212 {
1213     if (params->len != 3) {
1214         gdb_put_packet("E22");
1215         return;
1216     }
1217
1218     /* gdb_hextomem() reads 2*len bytes */
1219     if (get_param(params, 1)->val_ull >
1220         strlen(get_param(params, 2)->data) / 2) {
1221         gdb_put_packet("E22");
1222         return;
1223     }
1224
1225     gdb_hextomem(gdbserver_state.mem_buf, get_param(params, 2)->data,
1226                  get_param(params, 1)->val_ull);
1227     if (gdb_target_memory_rw_debug(gdbserver_state.g_cpu,
1228                                    get_param(params, 0)->val_ull,
1229                                    gdbserver_state.mem_buf->data,
1230                                    gdbserver_state.mem_buf->len, true)) {
1231         gdb_put_packet("E14");
1232         return;
1233     }
1234
1235     gdb_put_packet("OK");
1236 }
1237
1238 static void handle_read_mem(GArray *params, void *user_ctx)
1239 {
1240     if (params->len != 2) {
1241         gdb_put_packet("E22");
1242         return;
1243     }
1244
1245     /* gdb_memtohex() doubles the required space */
1246     if (get_param(params, 1)->val_ull > MAX_PACKET_LENGTH / 2) {
1247         gdb_put_packet("E22");
1248         return;
1249     }
1250
1251     g_byte_array_set_size(gdbserver_state.mem_buf,
1252                           get_param(params, 1)->val_ull);
1253
1254     if (gdb_target_memory_rw_debug(gdbserver_state.g_cpu,
1255                                    get_param(params, 0)->val_ull,
1256                                    gdbserver_state.mem_buf->data,
1257                                    gdbserver_state.mem_buf->len, false)) {
1258         gdb_put_packet("E14");
1259         return;
1260     }
1261
1262     gdb_memtohex(gdbserver_state.str_buf, gdbserver_state.mem_buf->data,
1263              gdbserver_state.mem_buf->len);
1264     gdb_put_strbuf();
1265 }
1266
1267 static void handle_write_all_regs(GArray *params, void *user_ctx)
1268 {
1269     int reg_id;
1270     size_t len;
1271     uint8_t *registers;
1272     int reg_size;
1273
1274     if (!params->len) {
1275         return;
1276     }
1277
1278     cpu_synchronize_state(gdbserver_state.g_cpu);
1279     len = strlen(get_param(params, 0)->data) / 2;
1280     gdb_hextomem(gdbserver_state.mem_buf, get_param(params, 0)->data, len);
1281     registers = gdbserver_state.mem_buf->data;
1282     for (reg_id = 0;
1283          reg_id < gdbserver_state.g_cpu->gdb_num_g_regs && len > 0;
1284          reg_id++) {
1285         reg_size = gdb_write_register(gdbserver_state.g_cpu, registers, reg_id);
1286         len -= reg_size;
1287         registers += reg_size;
1288     }
1289     gdb_put_packet("OK");
1290 }
1291
1292 static void handle_read_all_regs(GArray *params, void *user_ctx)
1293 {
1294     int reg_id;
1295     size_t len;
1296
1297     cpu_synchronize_state(gdbserver_state.g_cpu);
1298     g_byte_array_set_size(gdbserver_state.mem_buf, 0);
1299     len = 0;
1300     for (reg_id = 0; reg_id < gdbserver_state.g_cpu->gdb_num_g_regs; reg_id++) {
1301         len += gdb_read_register(gdbserver_state.g_cpu,
1302                                  gdbserver_state.mem_buf,
1303                                  reg_id);
1304     }
1305     g_assert(len == gdbserver_state.mem_buf->len);
1306
1307     gdb_memtohex(gdbserver_state.str_buf, gdbserver_state.mem_buf->data, len);
1308     gdb_put_strbuf();
1309 }
1310
1311
1312 static void handle_step(GArray *params, void *user_ctx)
1313 {
1314     if (params->len) {
1315         gdb_set_cpu_pc(get_param(params, 0)->val_ull);
1316     }
1317
1318     cpu_single_step(gdbserver_state.c_cpu, gdbserver_state.sstep_flags);
1319     gdb_continue();
1320 }
1321
1322 static void handle_backward(GArray *params, void *user_ctx)
1323 {
1324     if (!gdb_can_reverse()) {
1325         gdb_put_packet("E22");
1326     }
1327     if (params->len == 1) {
1328         switch (get_param(params, 0)->opcode) {
1329         case 's':
1330             if (replay_reverse_step()) {
1331                 gdb_continue();
1332             } else {
1333                 gdb_put_packet("E14");
1334             }
1335             return;
1336         case 'c':
1337             if (replay_reverse_continue()) {
1338                 gdb_continue();
1339             } else {
1340                 gdb_put_packet("E14");
1341             }
1342             return;
1343         }
1344     }
1345
1346     /* Default invalid command */
1347     gdb_put_packet("");
1348 }
1349
1350 static void handle_v_cont_query(GArray *params, void *user_ctx)
1351 {
1352     gdb_put_packet("vCont;c;C;s;S");
1353 }
1354
1355 static void handle_v_cont(GArray *params, void *user_ctx)
1356 {
1357     int res;
1358
1359     if (!params->len) {
1360         return;
1361     }
1362
1363     res = gdb_handle_vcont(get_param(params, 0)->data);
1364     if ((res == -EINVAL) || (res == -ERANGE)) {
1365         gdb_put_packet("E22");
1366     } else if (res) {
1367         gdb_put_packet("");
1368     }
1369 }
1370
1371 static void handle_v_attach(GArray *params, void *user_ctx)
1372 {
1373     GDBProcess *process;
1374     CPUState *cpu;
1375
1376     g_string_assign(gdbserver_state.str_buf, "E22");
1377     if (!params->len) {
1378         goto cleanup;
1379     }
1380
1381     process = gdb_get_process(get_param(params, 0)->val_ul);
1382     if (!process) {
1383         goto cleanup;
1384     }
1385
1386     cpu = gdb_get_first_cpu_in_process(process);
1387     if (!cpu) {
1388         goto cleanup;
1389     }
1390
1391     process->attached = true;
1392     gdbserver_state.g_cpu = cpu;
1393     gdbserver_state.c_cpu = cpu;
1394
1395     if (gdbserver_state.allow_stop_reply) {
1396         g_string_printf(gdbserver_state.str_buf, "T%02xthread:", GDB_SIGNAL_TRAP);
1397         gdb_append_thread_id(cpu, gdbserver_state.str_buf);
1398         g_string_append_c(gdbserver_state.str_buf, ';');
1399         gdbserver_state.allow_stop_reply = false;
1400 cleanup:
1401         gdb_put_strbuf();
1402     }
1403 }
1404
1405 static void handle_v_kill(GArray *params, void *user_ctx)
1406 {
1407     /* Kill the target */
1408     gdb_put_packet("OK");
1409     error_report("QEMU: Terminated via GDBstub");
1410     gdb_exit(0);
1411     gdb_qemu_exit(0);
1412 }
1413
1414 static const GdbCmdParseEntry gdb_v_commands_table[] = {
1415     /* Order is important if has same prefix */
1416     {
1417         .handler = handle_v_cont_query,
1418         .cmd = "Cont?",
1419         .cmd_startswith = 1
1420     },
1421     {
1422         .handler = handle_v_cont,
1423         .cmd = "Cont",
1424         .cmd_startswith = 1,
1425         .allow_stop_reply = true,
1426         .schema = "s0"
1427     },
1428     {
1429         .handler = handle_v_attach,
1430         .cmd = "Attach;",
1431         .cmd_startswith = 1,
1432         .allow_stop_reply = true,
1433         .schema = "l0"
1434     },
1435     {
1436         .handler = handle_v_kill,
1437         .cmd = "Kill;",
1438         .cmd_startswith = 1
1439     },
1440 #ifdef CONFIG_USER_ONLY
1441     /*
1442      * Host I/O Packets. See [1] for details.
1443      * [1] https://sourceware.org/gdb/onlinedocs/gdb/Host-I_002fO-Packets.html
1444      */
1445     {
1446         .handler = gdb_handle_v_file_open,
1447         .cmd = "File:open:",
1448         .cmd_startswith = 1,
1449         .schema = "s,L,L0"
1450     },
1451     {
1452         .handler = gdb_handle_v_file_close,
1453         .cmd = "File:close:",
1454         .cmd_startswith = 1,
1455         .schema = "l0"
1456     },
1457     {
1458         .handler = gdb_handle_v_file_pread,
1459         .cmd = "File:pread:",
1460         .cmd_startswith = 1,
1461         .schema = "l,L,L0"
1462     },
1463     {
1464         .handler = gdb_handle_v_file_readlink,
1465         .cmd = "File:readlink:",
1466         .cmd_startswith = 1,
1467         .schema = "s0"
1468     },
1469 #endif
1470 };
1471
1472 static void handle_v_commands(GArray *params, void *user_ctx)
1473 {
1474     if (!params->len) {
1475         return;
1476     }
1477
1478     if (process_string_cmd(get_param(params, 0)->data,
1479                            gdb_v_commands_table,
1480                            ARRAY_SIZE(gdb_v_commands_table))) {
1481         gdb_put_packet("");
1482     }
1483 }
1484
1485 static void handle_query_qemu_sstepbits(GArray *params, void *user_ctx)
1486 {
1487     g_string_printf(gdbserver_state.str_buf, "ENABLE=%x", SSTEP_ENABLE);
1488
1489     if (gdbserver_state.supported_sstep_flags & SSTEP_NOIRQ) {
1490         g_string_append_printf(gdbserver_state.str_buf, ",NOIRQ=%x",
1491                                SSTEP_NOIRQ);
1492     }
1493
1494     if (gdbserver_state.supported_sstep_flags & SSTEP_NOTIMER) {
1495         g_string_append_printf(gdbserver_state.str_buf, ",NOTIMER=%x",
1496                                SSTEP_NOTIMER);
1497     }
1498
1499     gdb_put_strbuf();
1500 }
1501
1502 static void handle_set_qemu_sstep(GArray *params, void *user_ctx)
1503 {
1504     int new_sstep_flags;
1505
1506     if (!params->len) {
1507         return;
1508     }
1509
1510     new_sstep_flags = get_param(params, 0)->val_ul;
1511
1512     if (new_sstep_flags  & ~gdbserver_state.supported_sstep_flags) {
1513         gdb_put_packet("E22");
1514         return;
1515     }
1516
1517     gdbserver_state.sstep_flags = new_sstep_flags;
1518     gdb_put_packet("OK");
1519 }
1520
1521 static void handle_query_qemu_sstep(GArray *params, void *user_ctx)
1522 {
1523     g_string_printf(gdbserver_state.str_buf, "0x%x",
1524                     gdbserver_state.sstep_flags);
1525     gdb_put_strbuf();
1526 }
1527
1528 static void handle_query_curr_tid(GArray *params, void *user_ctx)
1529 {
1530     CPUState *cpu;
1531     GDBProcess *process;
1532
1533     /*
1534      * "Current thread" remains vague in the spec, so always return
1535      * the first thread of the current process (gdb returns the
1536      * first thread).
1537      */
1538     process = gdb_get_cpu_process(gdbserver_state.g_cpu);
1539     cpu = gdb_get_first_cpu_in_process(process);
1540     g_string_assign(gdbserver_state.str_buf, "QC");
1541     gdb_append_thread_id(cpu, gdbserver_state.str_buf);
1542     gdb_put_strbuf();
1543 }
1544
1545 static void handle_query_threads(GArray *params, void *user_ctx)
1546 {
1547     if (!gdbserver_state.query_cpu) {
1548         gdb_put_packet("l");
1549         return;
1550     }
1551
1552     g_string_assign(gdbserver_state.str_buf, "m");
1553     gdb_append_thread_id(gdbserver_state.query_cpu, gdbserver_state.str_buf);
1554     gdb_put_strbuf();
1555     gdbserver_state.query_cpu = gdb_next_attached_cpu(gdbserver_state.query_cpu);
1556 }
1557
1558 static void handle_query_first_threads(GArray *params, void *user_ctx)
1559 {
1560     gdbserver_state.query_cpu = gdb_first_attached_cpu();
1561     handle_query_threads(params, user_ctx);
1562 }
1563
1564 static void handle_query_thread_extra(GArray *params, void *user_ctx)
1565 {
1566     g_autoptr(GString) rs = g_string_new(NULL);
1567     CPUState *cpu;
1568
1569     if (!params->len ||
1570         get_param(params, 0)->thread_id.kind == GDB_READ_THREAD_ERR) {
1571         gdb_put_packet("E22");
1572         return;
1573     }
1574
1575     cpu = gdb_get_cpu(get_param(params, 0)->thread_id.pid,
1576                       get_param(params, 0)->thread_id.tid);
1577     if (!cpu) {
1578         return;
1579     }
1580
1581     cpu_synchronize_state(cpu);
1582
1583     if (gdbserver_state.multiprocess && (gdbserver_state.process_num > 1)) {
1584         /* Print the CPU model and name in multiprocess mode */
1585         ObjectClass *oc = object_get_class(OBJECT(cpu));
1586         const char *cpu_model = object_class_get_name(oc);
1587         const char *cpu_name =
1588             object_get_canonical_path_component(OBJECT(cpu));
1589         g_string_printf(rs, "%s %s [%s]", cpu_model, cpu_name,
1590                         cpu->halted ? "halted " : "running");
1591     } else {
1592         g_string_printf(rs, "CPU#%d [%s]", cpu->cpu_index,
1593                         cpu->halted ? "halted " : "running");
1594     }
1595     trace_gdbstub_op_extra_info(rs->str);
1596     gdb_memtohex(gdbserver_state.str_buf, (uint8_t *)rs->str, rs->len);
1597     gdb_put_strbuf();
1598 }
1599
1600 static void handle_query_supported(GArray *params, void *user_ctx)
1601 {
1602     CPUClass *cc;
1603
1604     g_string_printf(gdbserver_state.str_buf, "PacketSize=%x", MAX_PACKET_LENGTH);
1605     cc = CPU_GET_CLASS(first_cpu);
1606     if (cc->gdb_core_xml_file) {
1607         g_string_append(gdbserver_state.str_buf, ";qXfer:features:read+");
1608     }
1609
1610     if (gdb_can_reverse()) {
1611         g_string_append(gdbserver_state.str_buf,
1612             ";ReverseStep+;ReverseContinue+");
1613     }
1614
1615 #if defined(CONFIG_USER_ONLY)
1616 #if defined(CONFIG_LINUX)
1617     if (gdbserver_state.c_cpu->opaque) {
1618         g_string_append(gdbserver_state.str_buf, ";qXfer:auxv:read+");
1619     }
1620 #endif
1621     g_string_append(gdbserver_state.str_buf, ";qXfer:exec-file:read+");
1622 #endif
1623
1624     if (params->len &&
1625         strstr(get_param(params, 0)->data, "multiprocess+")) {
1626         gdbserver_state.multiprocess = true;
1627     }
1628
1629     g_string_append(gdbserver_state.str_buf, ";vContSupported+;multiprocess+");
1630     gdb_put_strbuf();
1631 }
1632
1633 static void handle_query_xfer_features(GArray *params, void *user_ctx)
1634 {
1635     GDBProcess *process;
1636     CPUClass *cc;
1637     unsigned long len, total_len, addr;
1638     const char *xml;
1639     const char *p;
1640
1641     if (params->len < 3) {
1642         gdb_put_packet("E22");
1643         return;
1644     }
1645
1646     process = gdb_get_cpu_process(gdbserver_state.g_cpu);
1647     cc = CPU_GET_CLASS(gdbserver_state.g_cpu);
1648     if (!cc->gdb_core_xml_file) {
1649         gdb_put_packet("");
1650         return;
1651     }
1652
1653     p = get_param(params, 0)->data;
1654     xml = get_feature_xml(p, &p, process);
1655     if (!xml) {
1656         gdb_put_packet("E00");
1657         return;
1658     }
1659
1660     addr = get_param(params, 1)->val_ul;
1661     len = get_param(params, 2)->val_ul;
1662     total_len = strlen(xml);
1663     if (addr > total_len) {
1664         gdb_put_packet("E00");
1665         return;
1666     }
1667
1668     if (len > (MAX_PACKET_LENGTH - 5) / 2) {
1669         len = (MAX_PACKET_LENGTH - 5) / 2;
1670     }
1671
1672     if (len < total_len - addr) {
1673         g_string_assign(gdbserver_state.str_buf, "m");
1674         gdb_memtox(gdbserver_state.str_buf, xml + addr, len);
1675     } else {
1676         g_string_assign(gdbserver_state.str_buf, "l");
1677         gdb_memtox(gdbserver_state.str_buf, xml + addr, total_len - addr);
1678     }
1679
1680     gdb_put_packet_binary(gdbserver_state.str_buf->str,
1681                       gdbserver_state.str_buf->len, true);
1682 }
1683
1684 static void handle_query_qemu_supported(GArray *params, void *user_ctx)
1685 {
1686     g_string_printf(gdbserver_state.str_buf, "sstepbits;sstep");
1687 #ifndef CONFIG_USER_ONLY
1688     g_string_append(gdbserver_state.str_buf, ";PhyMemMode");
1689 #endif
1690     gdb_put_strbuf();
1691 }
1692
1693 static const GdbCmdParseEntry gdb_gen_query_set_common_table[] = {
1694     /* Order is important if has same prefix */
1695     {
1696         .handler = handle_query_qemu_sstepbits,
1697         .cmd = "qemu.sstepbits",
1698     },
1699     {
1700         .handler = handle_query_qemu_sstep,
1701         .cmd = "qemu.sstep",
1702     },
1703     {
1704         .handler = handle_set_qemu_sstep,
1705         .cmd = "qemu.sstep=",
1706         .cmd_startswith = 1,
1707         .schema = "l0"
1708     },
1709 };
1710
1711 static const GdbCmdParseEntry gdb_gen_query_table[] = {
1712     {
1713         .handler = handle_query_curr_tid,
1714         .cmd = "C",
1715     },
1716     {
1717         .handler = handle_query_threads,
1718         .cmd = "sThreadInfo",
1719     },
1720     {
1721         .handler = handle_query_first_threads,
1722         .cmd = "fThreadInfo",
1723     },
1724     {
1725         .handler = handle_query_thread_extra,
1726         .cmd = "ThreadExtraInfo,",
1727         .cmd_startswith = 1,
1728         .schema = "t0"
1729     },
1730 #ifdef CONFIG_USER_ONLY
1731     {
1732         .handler = gdb_handle_query_offsets,
1733         .cmd = "Offsets",
1734     },
1735 #else
1736     {
1737         .handler = gdb_handle_query_rcmd,
1738         .cmd = "Rcmd,",
1739         .cmd_startswith = 1,
1740         .schema = "s0"
1741     },
1742 #endif
1743     {
1744         .handler = handle_query_supported,
1745         .cmd = "Supported:",
1746         .cmd_startswith = 1,
1747         .schema = "s0"
1748     },
1749     {
1750         .handler = handle_query_supported,
1751         .cmd = "Supported",
1752         .schema = "s0"
1753     },
1754     {
1755         .handler = handle_query_xfer_features,
1756         .cmd = "Xfer:features:read:",
1757         .cmd_startswith = 1,
1758         .schema = "s:l,l0"
1759     },
1760 #if defined(CONFIG_USER_ONLY)
1761 #if defined(CONFIG_LINUX)
1762     {
1763         .handler = gdb_handle_query_xfer_auxv,
1764         .cmd = "Xfer:auxv:read::",
1765         .cmd_startswith = 1,
1766         .schema = "l,l0"
1767     },
1768 #endif
1769     {
1770         .handler = gdb_handle_query_xfer_exec_file,
1771         .cmd = "Xfer:exec-file:read:",
1772         .cmd_startswith = 1,
1773         .schema = "l:l,l0"
1774     },
1775 #endif
1776     {
1777         .handler = gdb_handle_query_attached,
1778         .cmd = "Attached:",
1779         .cmd_startswith = 1
1780     },
1781     {
1782         .handler = gdb_handle_query_attached,
1783         .cmd = "Attached",
1784     },
1785     {
1786         .handler = handle_query_qemu_supported,
1787         .cmd = "qemu.Supported",
1788     },
1789 #ifndef CONFIG_USER_ONLY
1790     {
1791         .handler = gdb_handle_query_qemu_phy_mem_mode,
1792         .cmd = "qemu.PhyMemMode",
1793     },
1794 #endif
1795 };
1796
1797 static const GdbCmdParseEntry gdb_gen_set_table[] = {
1798     /* Order is important if has same prefix */
1799     {
1800         .handler = handle_set_qemu_sstep,
1801         .cmd = "qemu.sstep:",
1802         .cmd_startswith = 1,
1803         .schema = "l0"
1804     },
1805 #ifndef CONFIG_USER_ONLY
1806     {
1807         .handler = gdb_handle_set_qemu_phy_mem_mode,
1808         .cmd = "qemu.PhyMemMode:",
1809         .cmd_startswith = 1,
1810         .schema = "l0"
1811     },
1812 #endif
1813 };
1814
1815 static void handle_gen_query(GArray *params, void *user_ctx)
1816 {
1817     if (!params->len) {
1818         return;
1819     }
1820
1821     if (!process_string_cmd(get_param(params, 0)->data,
1822                             gdb_gen_query_set_common_table,
1823                             ARRAY_SIZE(gdb_gen_query_set_common_table))) {
1824         return;
1825     }
1826
1827     if (process_string_cmd(get_param(params, 0)->data,
1828                            gdb_gen_query_table,
1829                            ARRAY_SIZE(gdb_gen_query_table))) {
1830         gdb_put_packet("");
1831     }
1832 }
1833
1834 static void handle_gen_set(GArray *params, void *user_ctx)
1835 {
1836     if (!params->len) {
1837         return;
1838     }
1839
1840     if (!process_string_cmd(get_param(params, 0)->data,
1841                             gdb_gen_query_set_common_table,
1842                             ARRAY_SIZE(gdb_gen_query_set_common_table))) {
1843         return;
1844     }
1845
1846     if (process_string_cmd(get_param(params, 0)->data,
1847                            gdb_gen_set_table,
1848                            ARRAY_SIZE(gdb_gen_set_table))) {
1849         gdb_put_packet("");
1850     }
1851 }
1852
1853 static void handle_target_halt(GArray *params, void *user_ctx)
1854 {
1855     if (gdbserver_state.allow_stop_reply) {
1856         g_string_printf(gdbserver_state.str_buf, "T%02xthread:", GDB_SIGNAL_TRAP);
1857         gdb_append_thread_id(gdbserver_state.c_cpu, gdbserver_state.str_buf);
1858         g_string_append_c(gdbserver_state.str_buf, ';');
1859         gdb_put_strbuf();
1860         gdbserver_state.allow_stop_reply = false;
1861     }
1862     /*
1863      * Remove all the breakpoints when this query is issued,
1864      * because gdb is doing an initial connect and the state
1865      * should be cleaned up.
1866      */
1867     gdb_breakpoint_remove_all(gdbserver_state.c_cpu);
1868 }
1869
1870 static int gdb_handle_packet(const char *line_buf)
1871 {
1872     const GdbCmdParseEntry *cmd_parser = NULL;
1873
1874     trace_gdbstub_io_command(line_buf);
1875
1876     switch (line_buf[0]) {
1877     case '!':
1878         gdb_put_packet("OK");
1879         break;
1880     case '?':
1881         {
1882             static const GdbCmdParseEntry target_halted_cmd_desc = {
1883                 .handler = handle_target_halt,
1884                 .cmd = "?",
1885                 .cmd_startswith = 1,
1886                 .allow_stop_reply = true,
1887             };
1888             cmd_parser = &target_halted_cmd_desc;
1889         }
1890         break;
1891     case 'c':
1892         {
1893             static const GdbCmdParseEntry continue_cmd_desc = {
1894                 .handler = handle_continue,
1895                 .cmd = "c",
1896                 .cmd_startswith = 1,
1897                 .allow_stop_reply = true,
1898                 .schema = "L0"
1899             };
1900             cmd_parser = &continue_cmd_desc;
1901         }
1902         break;
1903     case 'C':
1904         {
1905             static const GdbCmdParseEntry cont_with_sig_cmd_desc = {
1906                 .handler = handle_cont_with_sig,
1907                 .cmd = "C",
1908                 .cmd_startswith = 1,
1909                 .allow_stop_reply = true,
1910                 .schema = "l0"
1911             };
1912             cmd_parser = &cont_with_sig_cmd_desc;
1913         }
1914         break;
1915     case 'v':
1916         {
1917             static const GdbCmdParseEntry v_cmd_desc = {
1918                 .handler = handle_v_commands,
1919                 .cmd = "v",
1920                 .cmd_startswith = 1,
1921                 .schema = "s0"
1922             };
1923             cmd_parser = &v_cmd_desc;
1924         }
1925         break;
1926     case 'k':
1927         /* Kill the target */
1928         error_report("QEMU: Terminated via GDBstub");
1929         gdb_exit(0);
1930         gdb_qemu_exit(0);
1931         break;
1932     case 'D':
1933         {
1934             static const GdbCmdParseEntry detach_cmd_desc = {
1935                 .handler = handle_detach,
1936                 .cmd = "D",
1937                 .cmd_startswith = 1,
1938                 .schema = "?.l0"
1939             };
1940             cmd_parser = &detach_cmd_desc;
1941         }
1942         break;
1943     case 's':
1944         {
1945             static const GdbCmdParseEntry step_cmd_desc = {
1946                 .handler = handle_step,
1947                 .cmd = "s",
1948                 .cmd_startswith = 1,
1949                 .allow_stop_reply = true,
1950                 .schema = "L0"
1951             };
1952             cmd_parser = &step_cmd_desc;
1953         }
1954         break;
1955     case 'b':
1956         {
1957             static const GdbCmdParseEntry backward_cmd_desc = {
1958                 .handler = handle_backward,
1959                 .cmd = "b",
1960                 .cmd_startswith = 1,
1961                 .allow_stop_reply = true,
1962                 .schema = "o0"
1963             };
1964             cmd_parser = &backward_cmd_desc;
1965         }
1966         break;
1967     case 'F':
1968         {
1969             static const GdbCmdParseEntry file_io_cmd_desc = {
1970                 .handler = gdb_handle_file_io,
1971                 .cmd = "F",
1972                 .cmd_startswith = 1,
1973                 .schema = "L,L,o0"
1974             };
1975             cmd_parser = &file_io_cmd_desc;
1976         }
1977         break;
1978     case 'g':
1979         {
1980             static const GdbCmdParseEntry read_all_regs_cmd_desc = {
1981                 .handler = handle_read_all_regs,
1982                 .cmd = "g",
1983                 .cmd_startswith = 1
1984             };
1985             cmd_parser = &read_all_regs_cmd_desc;
1986         }
1987         break;
1988     case 'G':
1989         {
1990             static const GdbCmdParseEntry write_all_regs_cmd_desc = {
1991                 .handler = handle_write_all_regs,
1992                 .cmd = "G",
1993                 .cmd_startswith = 1,
1994                 .schema = "s0"
1995             };
1996             cmd_parser = &write_all_regs_cmd_desc;
1997         }
1998         break;
1999     case 'm':
2000         {
2001             static const GdbCmdParseEntry read_mem_cmd_desc = {
2002                 .handler = handle_read_mem,
2003                 .cmd = "m",
2004                 .cmd_startswith = 1,
2005                 .schema = "L,L0"
2006             };
2007             cmd_parser = &read_mem_cmd_desc;
2008         }
2009         break;
2010     case 'M':
2011         {
2012             static const GdbCmdParseEntry write_mem_cmd_desc = {
2013                 .handler = handle_write_mem,
2014                 .cmd = "M",
2015                 .cmd_startswith = 1,
2016                 .schema = "L,L:s0"
2017             };
2018             cmd_parser = &write_mem_cmd_desc;
2019         }
2020         break;
2021     case 'p':
2022         {
2023             static const GdbCmdParseEntry get_reg_cmd_desc = {
2024                 .handler = handle_get_reg,
2025                 .cmd = "p",
2026                 .cmd_startswith = 1,
2027                 .schema = "L0"
2028             };
2029             cmd_parser = &get_reg_cmd_desc;
2030         }
2031         break;
2032     case 'P':
2033         {
2034             static const GdbCmdParseEntry set_reg_cmd_desc = {
2035                 .handler = handle_set_reg,
2036                 .cmd = "P",
2037                 .cmd_startswith = 1,
2038                 .schema = "L?s0"
2039             };
2040             cmd_parser = &set_reg_cmd_desc;
2041         }
2042         break;
2043     case 'Z':
2044         {
2045             static const GdbCmdParseEntry insert_bp_cmd_desc = {
2046                 .handler = handle_insert_bp,
2047                 .cmd = "Z",
2048                 .cmd_startswith = 1,
2049                 .schema = "l?L?L0"
2050             };
2051             cmd_parser = &insert_bp_cmd_desc;
2052         }
2053         break;
2054     case 'z':
2055         {
2056             static const GdbCmdParseEntry remove_bp_cmd_desc = {
2057                 .handler = handle_remove_bp,
2058                 .cmd = "z",
2059                 .cmd_startswith = 1,
2060                 .schema = "l?L?L0"
2061             };
2062             cmd_parser = &remove_bp_cmd_desc;
2063         }
2064         break;
2065     case 'H':
2066         {
2067             static const GdbCmdParseEntry set_thread_cmd_desc = {
2068                 .handler = handle_set_thread,
2069                 .cmd = "H",
2070                 .cmd_startswith = 1,
2071                 .schema = "o.t0"
2072             };
2073             cmd_parser = &set_thread_cmd_desc;
2074         }
2075         break;
2076     case 'T':
2077         {
2078             static const GdbCmdParseEntry thread_alive_cmd_desc = {
2079                 .handler = handle_thread_alive,
2080                 .cmd = "T",
2081                 .cmd_startswith = 1,
2082                 .schema = "t0"
2083             };
2084             cmd_parser = &thread_alive_cmd_desc;
2085         }
2086         break;
2087     case 'q':
2088         {
2089             static const GdbCmdParseEntry gen_query_cmd_desc = {
2090                 .handler = handle_gen_query,
2091                 .cmd = "q",
2092                 .cmd_startswith = 1,
2093                 .schema = "s0"
2094             };
2095             cmd_parser = &gen_query_cmd_desc;
2096         }
2097         break;
2098     case 'Q':
2099         {
2100             static const GdbCmdParseEntry gen_set_cmd_desc = {
2101                 .handler = handle_gen_set,
2102                 .cmd = "Q",
2103                 .cmd_startswith = 1,
2104                 .schema = "s0"
2105             };
2106             cmd_parser = &gen_set_cmd_desc;
2107         }
2108         break;
2109     default:
2110         /* put empty packet */
2111         gdb_put_packet("");
2112         break;
2113     }
2114
2115     if (cmd_parser) {
2116         run_cmd_parser(line_buf, cmd_parser);
2117     }
2118
2119     return RS_IDLE;
2120 }
2121
2122 void gdb_set_stop_cpu(CPUState *cpu)
2123 {
2124     GDBProcess *p = gdb_get_cpu_process(cpu);
2125
2126     if (!p->attached) {
2127         /*
2128          * Having a stop CPU corresponding to a process that is not attached
2129          * confuses GDB. So we ignore the request.
2130          */
2131         return;
2132     }
2133
2134     gdbserver_state.c_cpu = cpu;
2135     gdbserver_state.g_cpu = cpu;
2136 }
2137
2138 void gdb_read_byte(uint8_t ch)
2139 {
2140     uint8_t reply;
2141
2142     gdbserver_state.allow_stop_reply = false;
2143 #ifndef CONFIG_USER_ONLY
2144     if (gdbserver_state.last_packet->len) {
2145         /* Waiting for a response to the last packet.  If we see the start
2146            of a new command then abandon the previous response.  */
2147         if (ch == '-') {
2148             trace_gdbstub_err_got_nack();
2149             gdb_put_buffer(gdbserver_state.last_packet->data,
2150                        gdbserver_state.last_packet->len);
2151         } else if (ch == '+') {
2152             trace_gdbstub_io_got_ack();
2153         } else {
2154             trace_gdbstub_io_got_unexpected(ch);
2155         }
2156
2157         if (ch == '+' || ch == '$') {
2158             g_byte_array_set_size(gdbserver_state.last_packet, 0);
2159         }
2160         if (ch != '$')
2161             return;
2162     }
2163     if (runstate_is_running()) {
2164         /*
2165          * When the CPU is running, we cannot do anything except stop
2166          * it when receiving a char. This is expected on a Ctrl-C in the
2167          * gdb client. Because we are in all-stop mode, gdb sends a
2168          * 0x03 byte which is not a usual packet, so we handle it specially
2169          * here, but it does expect a stop reply.
2170          */
2171         if (ch != 0x03) {
2172             trace_gdbstub_err_unexpected_runpkt(ch);
2173         } else {
2174             gdbserver_state.allow_stop_reply = true;
2175         }
2176         vm_stop(RUN_STATE_PAUSED);
2177     } else
2178 #endif
2179     {
2180         switch(gdbserver_state.state) {
2181         case RS_IDLE:
2182             if (ch == '$') {
2183                 /* start of command packet */
2184                 gdbserver_state.line_buf_index = 0;
2185                 gdbserver_state.line_sum = 0;
2186                 gdbserver_state.state = RS_GETLINE;
2187             } else if (ch == '+') {
2188                 /*
2189                  * do nothing, gdb may preemptively send out ACKs on
2190                  * initial connection
2191                  */
2192             } else {
2193                 trace_gdbstub_err_garbage(ch);
2194             }
2195             break;
2196         case RS_GETLINE:
2197             if (ch == '}') {
2198                 /* start escape sequence */
2199                 gdbserver_state.state = RS_GETLINE_ESC;
2200                 gdbserver_state.line_sum += ch;
2201             } else if (ch == '*') {
2202                 /* start run length encoding sequence */
2203                 gdbserver_state.state = RS_GETLINE_RLE;
2204                 gdbserver_state.line_sum += ch;
2205             } else if (ch == '#') {
2206                 /* end of command, start of checksum*/
2207                 gdbserver_state.state = RS_CHKSUM1;
2208             } else if (gdbserver_state.line_buf_index >= sizeof(gdbserver_state.line_buf) - 1) {
2209                 trace_gdbstub_err_overrun();
2210                 gdbserver_state.state = RS_IDLE;
2211             } else {
2212                 /* unescaped command character */
2213                 gdbserver_state.line_buf[gdbserver_state.line_buf_index++] = ch;
2214                 gdbserver_state.line_sum += ch;
2215             }
2216             break;
2217         case RS_GETLINE_ESC:
2218             if (ch == '#') {
2219                 /* unexpected end of command in escape sequence */
2220                 gdbserver_state.state = RS_CHKSUM1;
2221             } else if (gdbserver_state.line_buf_index >= sizeof(gdbserver_state.line_buf) - 1) {
2222                 /* command buffer overrun */
2223                 trace_gdbstub_err_overrun();
2224                 gdbserver_state.state = RS_IDLE;
2225             } else {
2226                 /* parse escaped character and leave escape state */
2227                 gdbserver_state.line_buf[gdbserver_state.line_buf_index++] = ch ^ 0x20;
2228                 gdbserver_state.line_sum += ch;
2229                 gdbserver_state.state = RS_GETLINE;
2230             }
2231             break;
2232         case RS_GETLINE_RLE:
2233             /*
2234              * Run-length encoding is explained in "Debugging with GDB /
2235              * Appendix E GDB Remote Serial Protocol / Overview".
2236              */
2237             if (ch < ' ' || ch == '#' || ch == '$' || ch > 126) {
2238                 /* invalid RLE count encoding */
2239                 trace_gdbstub_err_invalid_repeat(ch);
2240                 gdbserver_state.state = RS_GETLINE;
2241             } else {
2242                 /* decode repeat length */
2243                 int repeat = ch - ' ' + 3;
2244                 if (gdbserver_state.line_buf_index + repeat >= sizeof(gdbserver_state.line_buf) - 1) {
2245                     /* that many repeats would overrun the command buffer */
2246                     trace_gdbstub_err_overrun();
2247                     gdbserver_state.state = RS_IDLE;
2248                 } else if (gdbserver_state.line_buf_index < 1) {
2249                     /* got a repeat but we have nothing to repeat */
2250                     trace_gdbstub_err_invalid_rle();
2251                     gdbserver_state.state = RS_GETLINE;
2252                 } else {
2253                     /* repeat the last character */
2254                     memset(gdbserver_state.line_buf + gdbserver_state.line_buf_index,
2255                            gdbserver_state.line_buf[gdbserver_state.line_buf_index - 1], repeat);
2256                     gdbserver_state.line_buf_index += repeat;
2257                     gdbserver_state.line_sum += ch;
2258                     gdbserver_state.state = RS_GETLINE;
2259                 }
2260             }
2261             break;
2262         case RS_CHKSUM1:
2263             /* get high hex digit of checksum */
2264             if (!isxdigit(ch)) {
2265                 trace_gdbstub_err_checksum_invalid(ch);
2266                 gdbserver_state.state = RS_GETLINE;
2267                 break;
2268             }
2269             gdbserver_state.line_buf[gdbserver_state.line_buf_index] = '\0';
2270             gdbserver_state.line_csum = fromhex(ch) << 4;
2271             gdbserver_state.state = RS_CHKSUM2;
2272             break;
2273         case RS_CHKSUM2:
2274             /* get low hex digit of checksum */
2275             if (!isxdigit(ch)) {
2276                 trace_gdbstub_err_checksum_invalid(ch);
2277                 gdbserver_state.state = RS_GETLINE;
2278                 break;
2279             }
2280             gdbserver_state.line_csum |= fromhex(ch);
2281
2282             if (gdbserver_state.line_csum != (gdbserver_state.line_sum & 0xff)) {
2283                 trace_gdbstub_err_checksum_incorrect(gdbserver_state.line_sum, gdbserver_state.line_csum);
2284                 /* send NAK reply */
2285                 reply = '-';
2286                 gdb_put_buffer(&reply, 1);
2287                 gdbserver_state.state = RS_IDLE;
2288             } else {
2289                 /* send ACK reply */
2290                 reply = '+';
2291                 gdb_put_buffer(&reply, 1);
2292                 gdbserver_state.state = gdb_handle_packet(gdbserver_state.line_buf);
2293             }
2294             break;
2295         default:
2296             abort();
2297         }
2298     }
2299 }
2300
2301 /*
2302  * Create the process that will contain all the "orphan" CPUs (that are not
2303  * part of a CPU cluster). Note that if this process contains no CPUs, it won't
2304  * be attachable and thus will be invisible to the user.
2305  */
2306 void gdb_create_default_process(GDBState *s)
2307 {
2308     GDBProcess *process;
2309     int pid;
2310
2311 #ifdef CONFIG_USER_ONLY
2312     assert(gdbserver_state.process_num == 0);
2313     pid = getpid();
2314 #else
2315     if (gdbserver_state.process_num) {
2316         pid = s->processes[s->process_num - 1].pid;
2317     } else {
2318         pid = 0;
2319     }
2320     /* We need an available PID slot for this process */
2321     assert(pid < UINT32_MAX);
2322     pid++;
2323 #endif
2324
2325     s->processes = g_renew(GDBProcess, s->processes, ++s->process_num);
2326     process = &s->processes[s->process_num - 1];
2327     process->pid = pid;
2328     process->attached = false;
2329     process->target_xml = NULL;
2330 }
2331