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     gdb_get_reg_cb get_reg;
  51     gdb_set_reg_cb set_reg;
  52     const GDBFeature *feature;
  53 } GDBRegisterState;
  54
  55 GDBState gdbserver_state;
  56
  57 void gdb_init_gdbserver_state(void)
  58 {
  59     g_assert(!gdbserver_state.init);
  60     memset(&gdbserver_state, 0, sizeof(GDBState));
  61     gdbserver_state.init = true;
  62     gdbserver_state.str_buf = g_string_new(NULL);
  63     gdbserver_state.mem_buf = g_byte_array_sized_new(MAX_PACKET_LENGTH);
  64     gdbserver_state.last_packet = g_byte_array_sized_new(MAX_PACKET_LENGTH + 4);
  65
  66     /*
  67      * What single-step modes are supported is accelerator dependent.
  68      * By default try to use no IRQs and no timers while single
  69      * stepping so as to make single stepping like a typical ICE HW step.
  70      */
  71     gdbserver_state.supported_sstep_flags = accel_supported_gdbstub_sstep_flags();
  72     gdbserver_state.sstep_flags = SSTEP_ENABLE | SSTEP_NOIRQ | SSTEP_NOTIMER;
  73     gdbserver_state.sstep_flags &= gdbserver_state.supported_sstep_flags;
  74 }
  75
  76 /* writes 2*len+1 bytes in buf */
  77 void gdb_memtohex(GString *buf, const uint8_t *mem, int len)
  78 {
  79     int i, c;
  80     for(i = 0; i < len; i++) {
  81         c = mem[i];
  82         g_string_append_c(buf, tohex(c >> 4));
  83         g_string_append_c(buf, tohex(c & 0xf));
  84     }
  85     g_string_append_c(buf, '\0');
  86 }
  87
  88 void gdb_hextomem(GByteArray *mem, const char *buf, int len)
  89 {
  90     int i;
  91
  92     for(i = 0; i < len; i++) {
  93         guint8 byte = fromhex(buf[0]) << 4 | fromhex(buf[1]);
  94         g_byte_array_append(mem, &byte, 1);
  95         buf += 2;
  96     }
  97 }
  98
  99 static void hexdump(const char *buf, int len,
 100                     void (*trace_fn)(size_t ofs, char const *text))
 101 {
 102     char line_buffer[3 * 16 + 4 + 16 + 1];
 103
 104     size_t i;
 105     for (i = 0; i < len || (i & 0xF); ++i) {
 106         size_t byte_ofs = i & 15;
 107
 108         if (byte_ofs == 0) {
 109             memset(line_buffer, ' ', 3 * 16 + 4 + 16);
 110             line_buffer[3 * 16 + 4 + 16] = 0;
 111         }
 112
 113         size_t col_group = (i >> 2) & 3;
 114         size_t hex_col = byte_ofs * 3 + col_group;
 115         size_t txt_col = 3 * 16 + 4 + byte_ofs;
 116
 117         if (i < len) {
 118             char value = buf[i];
 119
 120             line_buffer[hex_col + 0] = tohex((value >> 4) & 0xF);
 121             line_buffer[hex_col + 1] = tohex((value >> 0) & 0xF);
 122             line_buffer[txt_col + 0] = (value >= ' ' && value < 127)
 123                     ? value
 124                     : '.';
 125         }
 126
 127         if (byte_ofs == 0xF)
 128             trace_fn(i & -16, line_buffer);
 129     }
 130 }
 131
 132 /* return -1 if error, 0 if OK */
 133 int gdb_put_packet_binary(const char *buf, int len, bool dump)
 134 {
 135     int csum, i;
 136     uint8_t footer[3];
 137
 138     if (dump && trace_event_get_state_backends(TRACE_GDBSTUB_IO_BINARYREPLY)) {
 139         hexdump(buf, len, trace_gdbstub_io_binaryreply);
 140     }
 141
 142     for(;;) {
 143         g_byte_array_set_size(gdbserver_state.last_packet, 0);
 144         g_byte_array_append(gdbserver_state.last_packet,
 145                             (const uint8_t *) "$", 1);
 146         g_byte_array_append(gdbserver_state.last_packet,
 147                             (const uint8_t *) buf, len);
 148         csum = 0;
 149         for(i = 0; i < len; i++) {
 150             csum += buf[i];
 151         }
 152         footer[0] = '#';
 153         footer[1] = tohex((csum >> 4) & 0xf);
 154         footer[2] = tohex((csum) & 0xf);
 155         g_byte_array_append(gdbserver_state.last_packet, footer, 3);
 156
 157         gdb_put_buffer(gdbserver_state.last_packet->data,
 158                    gdbserver_state.last_packet->len);
 159
 160         if (gdb_got_immediate_ack()) {
 161             break;
 162         }
 163     }
 164     return 0;
 165 }
 166
 167 /* return -1 if error, 0 if OK */
 168 int gdb_put_packet(const char *buf)
 169 {
 170     trace_gdbstub_io_reply(buf);
 171
 172     return gdb_put_packet_binary(buf, strlen(buf), false);
 173 }
 174
 175 void gdb_put_strbuf(void)
 176 {
 177     gdb_put_packet(gdbserver_state.str_buf->str);
 178 }
 179
 180 /* Encode data using the encoding for 'x' packets.  */
 181 void gdb_memtox(GString *buf, const char *mem, int len)
 182 {
 183     char c;
 184
 185     while (len--) {
 186         c = *(mem++);
 187         switch (c) {
 188         case '#': case '$': case '*': case '}':
 189             g_string_append_c(buf, '}');
 190             g_string_append_c(buf, c ^ 0x20);
 191             break;
 192         default:
 193             g_string_append_c(buf, c);
 194             break;
 195         }
 196     }
 197 }
 198
 199 static uint32_t gdb_get_cpu_pid(CPUState *cpu)
 200 {
 201 #ifdef CONFIG_USER_ONLY
 202     return getpid();
 203 #else
 204     if (cpu->cluster_index == UNASSIGNED_CLUSTER_INDEX) {
 205         /* Return the default process' PID */
 206         int index = gdbserver_state.process_num - 1;
 207         return gdbserver_state.processes[index].pid;
 208     }
 209     return cpu->cluster_index + 1;
 210 #endif
 211 }
 212
 213 GDBProcess *gdb_get_process(uint32_t pid)
 214 {
 215     int i;
 216
 217     if (!pid) {
 218         /* 0 means any process, we take the first one */
 219         return &gdbserver_state.processes[0];
 220     }
 221
 222     for (i = 0; i < gdbserver_state.process_num; i++) {
 223         if (gdbserver_state.processes[i].pid == pid) {
 224             return &gdbserver_state.processes[i];
 225         }
 226     }
 227
 228     return NULL;
 229 }
 230
 231 static GDBProcess *gdb_get_cpu_process(CPUState *cpu)
 232 {
 233     return gdb_get_process(gdb_get_cpu_pid(cpu));
 234 }
 235
 236 static CPUState *find_cpu(uint32_t thread_id)
 237 {
 238     CPUState *cpu;
 239
 240     CPU_FOREACH(cpu) {
 241         if (gdb_get_cpu_index(cpu) == thread_id) {
 242             return cpu;
 243         }
 244     }
 245
 246     return NULL;
 247 }
 248
 249 CPUState *gdb_get_first_cpu_in_process(GDBProcess *process)
 250 {
 251     CPUState *cpu;
 252
 253     CPU_FOREACH(cpu) {
 254         if (gdb_get_cpu_pid(cpu) == process->pid) {
 255             return cpu;
 256         }
 257     }
 258
 259     return NULL;
 260 }
 261
 262 static CPUState *gdb_next_cpu_in_process(CPUState *cpu)
 263 {
 264     uint32_t pid = gdb_get_cpu_pid(cpu);
 265     cpu = CPU_NEXT(cpu);
 266
 267     while (cpu) {
 268         if (gdb_get_cpu_pid(cpu) == pid) {
 269             break;
 270         }
 271
 272         cpu = CPU_NEXT(cpu);
 273     }
 274
 275     return cpu;
 276 }
 277
 278 /* Return the cpu following @cpu, while ignoring unattached processes. */
 279 static CPUState *gdb_next_attached_cpu(CPUState *cpu)
 280 {
 281     cpu = CPU_NEXT(cpu);
 282
 283     while (cpu) {
 284         if (gdb_get_cpu_process(cpu)->attached) {
 285             break;
 286         }
 287
 288         cpu = CPU_NEXT(cpu);
 289     }
 290
 291     return cpu;
 292 }
 293
 294 /* Return the first attached cpu */
 295 CPUState *gdb_first_attached_cpu(void)
 296 {
 297     CPUState *cpu = first_cpu;
 298     GDBProcess *process = gdb_get_cpu_process(cpu);
 299
 300     if (!process->attached) {
 301         return gdb_next_attached_cpu(cpu);
 302     }
 303
 304     return cpu;
 305 }
 306
 307 static CPUState *gdb_get_cpu(uint32_t pid, uint32_t tid)
 308 {
 309     GDBProcess *process;
 310     CPUState *cpu;
 311
 312     if (!pid && !tid) {
 313         /* 0 means any process/thread, we take the first attached one */
 314         return gdb_first_attached_cpu();
 315     } else if (pid && !tid) {
 316         /* any thread in a specific process */
 317         process = gdb_get_process(pid);
 318
 319         if (process == NULL) {
 320             return NULL;
 321         }
 322
 323         if (!process->attached) {
 324             return NULL;
 325         }
 326
 327         return gdb_get_first_cpu_in_process(process);
 328     } else {
 329         /* a specific thread */
 330         cpu = find_cpu(tid);
 331
 332         if (cpu == NULL) {
 333             return NULL;
 334         }
 335
 336         process = gdb_get_cpu_process(cpu);
 337
 338         if (pid && process->pid != pid) {
 339             return NULL;
 340         }
 341
 342         if (!process->attached) {
 343             return NULL;
 344         }
 345
 346         return cpu;
 347     }
 348 }
 349
 350 static const char *get_feature_xml(const char *p, const char **newp,
 351                                    GDBProcess *process)
 352 {
 353     CPUState *cpu = gdb_get_first_cpu_in_process(process);
 354     CPUClass *cc = CPU_GET_CLASS(cpu);
 355     GDBRegisterState *r;
 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             g_autoptr(GPtrArray) xml = g_ptr_array_new_with_free_func(g_free);
 370
 371             g_ptr_array_add(
 372                 xml,
 373                 g_strdup("<?xml version=\"1.0\"?>"
 374                          "<!DOCTYPE target SYSTEM \"gdb-target.dtd\">"
 375                          "<target>"));
 376
 377             if (cc->gdb_arch_name) {
 378                 g_ptr_array_add(
 379                     xml,
 380                     g_markup_printf_escaped("<architecture>%s</architecture>",
 381                                             cc->gdb_arch_name(cpu)));
 382             }
 383             for (guint i = 0; i < cpu->gdb_regs->len; i++) {
 384                 r = &g_array_index(cpu->gdb_regs, GDBRegisterState, i);
 385                 g_ptr_array_add(
 386                     xml,
 387                     g_markup_printf_escaped("<xi:include href=\"%s\"/>",
 388                                             r->feature->xmlname));
 389             }
 390             g_ptr_array_add(xml, g_strdup("</target>"));
 391             g_ptr_array_add(xml, NULL);
 392
 393             process->target_xml = g_strjoinv(NULL, (void *)xml->pdata);
 394         }
 395         return process->target_xml;
 396     }
 397     /* Is it one of the features? */
 398     for (guint i = 0; i < cpu->gdb_regs->len; i++) {
 399         r = &g_array_index(cpu->gdb_regs, GDBRegisterState, i);
 400         if (strncmp(p, r->feature->xmlname, len) == 0) {
 401             return r->feature->xml;
 402         }
 403     }
 404
 405     /* failed */
 406     return NULL;
 407 }
 408
 409 void gdb_feature_builder_init(GDBFeatureBuilder *builder, GDBFeature *feature,
 410                               const char *name, const char *xmlname,
 411                               int base_reg)
 412 {
 413     char *header = g_markup_printf_escaped(
 414         "<?xml version=\"1.0\"?>"
 415         "<!DOCTYPE feature SYSTEM \"gdb-target.dtd\">"
 416         "<feature name=\"%s\">",
 417         name);
 418
 419     builder->feature = feature;
 420     builder->xml = g_ptr_array_new();
 421     g_ptr_array_add(builder->xml, header);
 422     builder->regs = g_ptr_array_new();
 423     builder->base_reg = base_reg;
 424     feature->xmlname = xmlname;
 425     feature->name = name;
 426 }
 427
 428 void gdb_feature_builder_append_tag(const GDBFeatureBuilder *builder,
 429                                     const char *format, ...)
 430 {
 431     va_list ap;
 432     va_start(ap, format);
 433     g_ptr_array_add(builder->xml, g_markup_vprintf_escaped(format, ap));
 434     va_end(ap);
 435 }
 436
 437 void gdb_feature_builder_append_reg(const GDBFeatureBuilder *builder,
 438                                     const char *name,
 439                                     int bitsize,
 440                                     int regnum,
 441                                     const char *type,
 442                                     const char *group)
 443 {
 444     if (builder->regs->len <= regnum) {
 445         g_ptr_array_set_size(builder->regs, regnum + 1);
 446     }
 447
 448     builder->regs->pdata[regnum] = (gpointer *)name;
 449
 450     if (group) {
 451         gdb_feature_builder_append_tag(
 452             builder,
 453             "<reg name=\"%s\" bitsize=\"%d\" regnum=\"%d\" type=\"%s\" group=\"%s\"/>",
 454             name, bitsize, builder->base_reg + regnum, type, group);
 455     } else {
 456         gdb_feature_builder_append_tag(
 457             builder,
 458             "<reg name=\"%s\" bitsize=\"%d\" regnum=\"%d\" type=\"%s\"/>",
 459             name, bitsize, builder->base_reg + regnum, type);
 460     }
 461 }
 462
 463 void gdb_feature_builder_end(const GDBFeatureBuilder *builder)
 464 {
 465     g_ptr_array_add(builder->xml, (void *)"</feature>");
 466     g_ptr_array_add(builder->xml, NULL);
 467
 468     builder->feature->xml = g_strjoinv(NULL, (void *)builder->xml->pdata);
 469
 470     for (guint i = 0; i < builder->xml->len - 2; i++) {
 471         g_free(g_ptr_array_index(builder->xml, i));
 472     }
 473
 474     g_ptr_array_free(builder->xml, TRUE);
 475
 476     builder->feature->num_regs = builder->regs->len;
 477     builder->feature->regs = (void *)g_ptr_array_free(builder->regs, FALSE);
 478 }
 479
 480 const GDBFeature *gdb_find_static_feature(const char *xmlname)
 481 {
 482     const GDBFeature *feature;
 483
 484     for (feature = gdb_static_features; feature->xmlname; feature++) {
 485         if (!strcmp(feature->xmlname, xmlname)) {
 486             return feature;
 487         }
 488     }
 489
 490     g_assert_not_reached();
 491 }
 492
 493 GArray *gdb_get_register_list(CPUState *cpu)
 494 {
 495     GArray *results = g_array_new(true, true, sizeof(GDBRegDesc));
 496
 497     /* registers are only available once the CPU is initialised */
 498     if (!cpu->gdb_regs) {
 499         return results;
 500     }
 501
 502     for (int f = 0; f < cpu->gdb_regs->len; f++) {
 503         GDBRegisterState *r = &g_array_index(cpu->gdb_regs, GDBRegisterState, f);
 504         for (int i = 0; i < r->feature->num_regs; i++) {
 505             const char *name = r->feature->regs[i];
 506             GDBRegDesc desc = {
 507                 r->base_reg + i,
 508                 name,
 509                 r->feature->name
 510             };
 511             g_array_append_val(results, desc);
 512         }
 513     }
 514
 515     return results;
 516 }
 517
 518 int gdb_read_register(CPUState *cpu, GByteArray *buf, int reg)
 519 {
 520     CPUClass *cc = CPU_GET_CLASS(cpu);
 521     GDBRegisterState *r;
 522
 523     if (reg < cc->gdb_num_core_regs) {
 524         return cc->gdb_read_register(cpu, buf, reg);
 525     }
 526
 527     for (guint i = 0; i < cpu->gdb_regs->len; i++) {
 528         r = &g_array_index(cpu->gdb_regs, GDBRegisterState, i);
 529         if (r->base_reg <= reg && reg < r->base_reg + r->feature->num_regs) {
 530             return r->get_reg(cpu, buf, reg - r->base_reg);
 531         }
 532     }
 533     return 0;
 534 }
 535
 536 static int gdb_write_register(CPUState *cpu, uint8_t *mem_buf, int reg)
 537 {
 538     CPUClass *cc = CPU_GET_CLASS(cpu);
 539     GDBRegisterState *r;
 540
 541     if (reg < cc->gdb_num_core_regs) {
 542         return cc->gdb_write_register(cpu, mem_buf, reg);
 543     }
 544
 545     for (guint i = 0; i < cpu->gdb_regs->len; i++) {
 546         r =  &g_array_index(cpu->gdb_regs, GDBRegisterState, i);
 547         if (r->base_reg <= reg && reg < r->base_reg + r->feature->num_regs) {
 548             return r->set_reg(cpu, mem_buf, reg - r->base_reg);
 549         }
 550     }
 551     return 0;
 552 }
 553
 554 static void gdb_register_feature(CPUState *cpu, int base_reg,
 555                                  gdb_get_reg_cb get_reg, gdb_set_reg_cb set_reg,
 556                                  const GDBFeature *feature)
 557 {
 558     GDBRegisterState s = {
 559         .base_reg = base_reg,
 560         .get_reg = get_reg,
 561         .set_reg = set_reg,
 562         .feature = feature
 563     };
 564
 565     g_array_append_val(cpu->gdb_regs, s);
 566 }
 567
 568 void gdb_init_cpu(CPUState *cpu)
 569 {
 570     CPUClass *cc = CPU_GET_CLASS(cpu);
 571     const GDBFeature *feature;
 572
 573     cpu->gdb_regs = g_array_new(false, false, sizeof(GDBRegisterState));
 574
 575     if (cc->gdb_core_xml_file) {
 576         feature = gdb_find_static_feature(cc->gdb_core_xml_file);
 577         gdb_register_feature(cpu, 0,
 578                              cc->gdb_read_register, cc->gdb_write_register,
 579                              feature);
 580         cpu->gdb_num_regs = cpu->gdb_num_g_regs = feature->num_regs;
 581     }
 582
 583     if (cc->gdb_num_core_regs) {
 584         cpu->gdb_num_regs = cpu->gdb_num_g_regs = cc->gdb_num_core_regs;
 585     }
 586 }
 587
 588 void gdb_register_coprocessor(CPUState *cpu,
 589                               gdb_get_reg_cb get_reg, gdb_set_reg_cb set_reg,
 590                               const GDBFeature *feature, int g_pos)
 591 {
 592     GDBRegisterState *s;
 593     guint i;
 594     int base_reg = cpu->gdb_num_regs;
 595
 596     for (i = 0; i < cpu->gdb_regs->len; i++) {
 597         /* Check for duplicates.  */
 598         s = &g_array_index(cpu->gdb_regs, GDBRegisterState, i);
 599         if (s->feature == feature) {
 600             return;
 601         }
 602     }
 603
 604     gdb_register_feature(cpu, base_reg, get_reg, set_reg, feature);
 605
 606     /* Add to end of list.  */
 607     cpu->gdb_num_regs += feature->num_regs;
 608     if (g_pos) {
 609         if (g_pos != base_reg) {
 610             error_report("Error: Bad gdb register numbering for '%s', "
 611                          "expected %d got %d", feature->xml, g_pos, base_reg);
 612         } else {
 613             cpu->gdb_num_g_regs = cpu->gdb_num_regs;
 614         }
 615     }
 616 }
 617
 618 static void gdb_process_breakpoint_remove_all(GDBProcess *p)
 619 {
 620     CPUState *cpu = gdb_get_first_cpu_in_process(p);
 621
 622     while (cpu) {
 623         gdb_breakpoint_remove_all(cpu);
 624         cpu = gdb_next_cpu_in_process(cpu);
 625     }
 626 }
 627
 628
 629 static void gdb_set_cpu_pc(vaddr pc)
 630 {
 631     CPUState *cpu = gdbserver_state.c_cpu;
 632
 633     cpu_synchronize_state(cpu);
 634     cpu_set_pc(cpu, pc);
 635 }
 636
 637 void gdb_append_thread_id(CPUState *cpu, GString *buf)
 638 {
 639     if (gdbserver_state.multiprocess) {
 640         g_string_append_printf(buf, "p%02x.%02x",
 641                                gdb_get_cpu_pid(cpu), gdb_get_cpu_index(cpu));
 642     } else {
 643         g_string_append_printf(buf, "%02x", gdb_get_cpu_index(cpu));
 644     }
 645 }
 646
 647 static GDBThreadIdKind read_thread_id(const char *buf, const char **end_buf,
 648                                       uint32_t *pid, uint32_t *tid)
 649 {
 650     unsigned long p, t;
 651     int ret;
 652
 653     if (*buf == 'p') {
 654         buf++;
 655         ret = qemu_strtoul(buf, &buf, 16, &p);
 656
 657         if (ret) {
 658             return GDB_READ_THREAD_ERR;
 659         }
 660
 661         /* Skip '.' */
 662         buf++;
 663     } else {
 664         p = 0;
 665     }
 666
 667     ret = qemu_strtoul(buf, &buf, 16, &t);
 668
 669     if (ret) {
 670         return GDB_READ_THREAD_ERR;
 671     }
 672
 673     *end_buf = buf;
 674
 675     if (p == -1) {
 676         return GDB_ALL_PROCESSES;
 677     }
 678
 679     if (pid) {
 680         *pid = p;
 681     }
 682
 683     if (t == -1) {
 684         return GDB_ALL_THREADS;
 685     }
 686
 687     if (tid) {
 688         *tid = t;
 689     }
 690
 691     return GDB_ONE_THREAD;
 692 }
 693
 694 /**
 695  * gdb_handle_vcont - Parses and handles a vCont packet.
 696  * returns -ENOTSUP if a command is unsupported, -EINVAL or -ERANGE if there is
 697  *         a format error, 0 on success.
 698  */
 699 static int gdb_handle_vcont(const char *p)
 700 {
 701     int res, signal = 0;
 702     char cur_action;
 703     unsigned long tmp;
 704     uint32_t pid, tid;
 705     GDBProcess *process;
 706     CPUState *cpu;
 707     GDBThreadIdKind kind;
 708     unsigned int max_cpus = gdb_get_max_cpus();
 709     /* uninitialised CPUs stay 0 */
 710     g_autofree char *newstates = g_new0(char, max_cpus);
 711
 712     /* mark valid CPUs with 1 */
 713     CPU_FOREACH(cpu) {
 714         newstates[cpu->cpu_index] = 1;
 715     }
 716
 717     /*
 718      * res keeps track of what error we are returning, with -ENOTSUP meaning
 719      * that the command is unknown or unsupported, thus returning an empty
 720      * packet, while -EINVAL and -ERANGE cause an E22 packet, due to invalid,
 721      *  or incorrect parameters passed.
 722      */
 723     res = 0;
 724
 725     /*
 726      * target_count and last_target keep track of how many CPUs we are going to
 727      * step or resume, and a pointer to the state structure of one of them,
 728      * respectively
 729      */
 730     int target_count = 0;
 731     CPUState *last_target = NULL;
 732
 733     while (*p) {
 734         if (*p++ != ';') {
 735             return -ENOTSUP;
 736         }
 737
 738         cur_action = *p++;
 739         if (cur_action == 'C' || cur_action == 'S') {
 740             cur_action = qemu_tolower(cur_action);
 741             res = qemu_strtoul(p, &p, 16, &tmp);
 742             if (res) {
 743                 return res;
 744             }
 745             signal = gdb_signal_to_target(tmp);
 746         } else if (cur_action != 'c' && cur_action != 's') {
 747             /* unknown/invalid/unsupported command */
 748             return -ENOTSUP;
 749         }
 750
 751         if (*p == '\0' || *p == ';') {
 752             /*
 753              * No thread specifier, action is on "all threads". The
 754              * specification is unclear regarding the process to act on. We
 755              * choose all processes.
 756              */
 757             kind = GDB_ALL_PROCESSES;
 758         } else if (*p++ == ':') {
 759             kind = read_thread_id(p, &p, &pid, &tid);
 760         } else {
 761             return -ENOTSUP;
 762         }
 763
 764         switch (kind) {
 765         case GDB_READ_THREAD_ERR:
 766             return -EINVAL;
 767
 768         case GDB_ALL_PROCESSES:
 769             cpu = gdb_first_attached_cpu();
 770             while (cpu) {
 771                 if (newstates[cpu->cpu_index] == 1) {
 772                     newstates[cpu->cpu_index] = cur_action;
 773
 774                     target_count++;
 775                     last_target = cpu;
 776                 }
 777
 778                 cpu = gdb_next_attached_cpu(cpu);
 779             }
 780             break;
 781
 782         case GDB_ALL_THREADS:
 783             process = gdb_get_process(pid);
 784
 785             if (!process->attached) {
 786                 return -EINVAL;
 787             }
 788
 789             cpu = gdb_get_first_cpu_in_process(process);
 790             while (cpu) {
 791                 if (newstates[cpu->cpu_index] == 1) {
 792                     newstates[cpu->cpu_index] = cur_action;
 793
 794                     target_count++;
 795                     last_target = cpu;
 796                 }
 797
 798                 cpu = gdb_next_cpu_in_process(cpu);
 799             }
 800             break;
 801
 802         case GDB_ONE_THREAD:
 803             cpu = gdb_get_cpu(pid, tid);
 804
 805             /* invalid CPU/thread specified */
 806             if (!cpu) {
 807                 return -EINVAL;
 808             }
 809
 810             /* only use if no previous match occourred */
 811             if (newstates[cpu->cpu_index] == 1) {
 812                 newstates[cpu->cpu_index] = cur_action;
 813
 814                 target_count++;
 815                 last_target = cpu;
 816             }
 817             break;
 818         }
 819     }
 820
 821     /*
 822      * if we're about to resume a specific set of CPUs/threads, make it so that
 823      * in case execution gets interrupted, we can send GDB a stop reply with a
 824      * correct value. it doesn't really matter which CPU we tell GDB the signal
 825      * happened in (VM pauses stop all of them anyway), so long as it is one of
 826      * the ones we resumed/single stepped here.
 827      */
 828     if (target_count > 0) {
 829         gdbserver_state.c_cpu = last_target;
 830     }
 831
 832     gdbserver_state.signal = signal;
 833     gdb_continue_partial(newstates);
 834     return res;
 835 }
 836
 837 static const char *cmd_next_param(const char *param, const char delimiter)
 838 {
 839     static const char all_delimiters[] = ",;:=";
 840     char curr_delimiters[2] = {0};
 841     const char *delimiters;
 842
 843     if (delimiter == '?') {
 844         delimiters = all_delimiters;
 845     } else if (delimiter == '0') {
 846         return strchr(param, '\0');
 847     } else if (delimiter == '.' && *param) {
 848         return param + 1;
 849     } else {
 850         curr_delimiters[0] = delimiter;
 851         delimiters = curr_delimiters;
 852     }
 853
 854     param += strcspn(param, delimiters);
 855     if (*param) {
 856         param++;
 857     }
 858     return param;
 859 }
 860
 861 static int cmd_parse_params(const char *data, const char *schema,
 862                             GArray *params)
 863 {
 864     const char *curr_schema, *curr_data;
 865
 866     g_assert(schema);
 867     g_assert(params->len == 0);
 868
 869     curr_schema = schema;
 870     curr_data = data;
 871     while (curr_schema[0] && curr_schema[1] && *curr_data) {
 872         GdbCmdVariant this_param;
 873
 874         switch (curr_schema[0]) {
 875         case 'l':
 876             if (qemu_strtoul(curr_data, &curr_data, 16,
 877                              &this_param.val_ul)) {
 878                 return -EINVAL;
 879             }
 880             curr_data = cmd_next_param(curr_data, curr_schema[1]);
 881             g_array_append_val(params, this_param);
 882             break;
 883         case 'L':
 884             if (qemu_strtou64(curr_data, &curr_data, 16,
 885                               (uint64_t *)&this_param.val_ull)) {
 886                 return -EINVAL;
 887             }
 888             curr_data = cmd_next_param(curr_data, curr_schema[1]);
 889             g_array_append_val(params, this_param);
 890             break;
 891         case 's':
 892             this_param.data = curr_data;
 893             curr_data = cmd_next_param(curr_data, curr_schema[1]);
 894             g_array_append_val(params, this_param);
 895             break;
 896         case 'o':
 897             this_param.opcode = *(uint8_t *)curr_data;
 898             curr_data = cmd_next_param(curr_data, curr_schema[1]);
 899             g_array_append_val(params, this_param);
 900             break;
 901         case 't':
 902             this_param.thread_id.kind =
 903                 read_thread_id(curr_data, &curr_data,
 904                                &this_param.thread_id.pid,
 905                                &this_param.thread_id.tid);
 906             curr_data = cmd_next_param(curr_data, curr_schema[1]);
 907             g_array_append_val(params, this_param);
 908             break;
 909         case '?':
 910             curr_data = cmd_next_param(curr_data, curr_schema[1]);
 911             break;
 912         default:
 913             return -EINVAL;
 914         }
 915         curr_schema += 2;
 916     }
 917
 918     return 0;
 919 }
 920
 921 typedef void (*GdbCmdHandler)(GArray *params, void *user_ctx);
 922
 923 /*
 924  * cmd_startswith -> cmd is compared using startswith
 925  *
 926  * allow_stop_reply -> true iff the gdbstub can respond to this command with a
 927  *   "stop reply" packet. The list of commands that accept such response is
 928  *   defined at the GDB Remote Serial Protocol documentation. see:
 929  *   https://sourceware.org/gdb/onlinedocs/gdb/Stop-Reply-Packets.html#Stop-Reply-Packets.
 930  *
 931  * schema definitions:
 932  * Each schema parameter entry consists of 2 chars,
 933  * the first char represents the parameter type handling
 934  * the second char represents the delimiter for the next parameter
 935  *
 936  * Currently supported schema types:
 937  * 'l' -> unsigned long (stored in .val_ul)
 938  * 'L' -> unsigned long long (stored in .val_ull)
 939  * 's' -> string (stored in .data)
 940  * 'o' -> single char (stored in .opcode)
 941  * 't' -> thread id (stored in .thread_id)
 942  * '?' -> skip according to delimiter
 943  *
 944  * Currently supported delimiters:
 945  * '?' -> Stop at any delimiter (",;:=\0")
 946  * '0' -> Stop at "\0"
 947  * '.' -> Skip 1 char unless reached "\0"
 948  * Any other value is treated as the delimiter value itself
 949  */
 950 typedef struct GdbCmdParseEntry {
 951     GdbCmdHandler handler;
 952     const char *cmd;
 953     bool cmd_startswith;
 954     const char *schema;
 955     bool allow_stop_reply;
 956 } GdbCmdParseEntry;
 957
 958 static inline int startswith(const char *string, const char *pattern)
 959 {
 960   return !strncmp(string, pattern, strlen(pattern));
 961 }
 962
 963 static int process_string_cmd(const char *data,
 964                               const GdbCmdParseEntry *cmds, int num_cmds)
 965 {
 966     int i;
 967     g_autoptr(GArray) params = g_array_new(false, true, sizeof(GdbCmdVariant));
 968
 969     if (!cmds) {
 970         return -1;
 971     }
 972
 973     for (i = 0; i < num_cmds; i++) {
 974         const GdbCmdParseEntry *cmd = &cmds[i];
 975         g_assert(cmd->handler && cmd->cmd);
 976
 977         if ((cmd->cmd_startswith && !startswith(data, cmd->cmd)) ||
 978             (!cmd->cmd_startswith && strcmp(cmd->cmd, data))) {
 979             continue;
 980         }
 981
 982         if (cmd->schema) {
 983             if (cmd_parse_params(&data[strlen(cmd->cmd)],
 984                                  cmd->schema, params)) {
 985                 return -1;
 986             }
 987         }
 988
 989         gdbserver_state.allow_stop_reply = cmd->allow_stop_reply;
 990         cmd->handler(params, NULL);
 991         return 0;
 992     }
 993
 994     return -1;
 995 }
 996
 997 static void run_cmd_parser(const char *data, const GdbCmdParseEntry *cmd)
 998 {
 999     if (!data) {
1000         return;
1001     }
1002
1003     g_string_set_size(gdbserver_state.str_buf, 0);
1004     g_byte_array_set_size(gdbserver_state.mem_buf, 0);
1005
1006     /* In case there was an error during the command parsing we must
1007     * send a NULL packet to indicate the command is not supported */
1008     if (process_string_cmd(data, cmd, 1)) {
1009         gdb_put_packet("");
1010     }
1011 }
1012
1013 static void handle_detach(GArray *params, void *user_ctx)
1014 {
1015     GDBProcess *process;
1016     uint32_t pid = 1;
1017
1018     if (gdbserver_state.multiprocess) {
1019         if (!params->len) {
1020             gdb_put_packet("E22");
1021             return;
1022         }
1023
1024         pid = get_param(params, 0)->val_ul;
1025     }
1026
1027     process = gdb_get_process(pid);
1028     gdb_process_breakpoint_remove_all(process);
1029     process->attached = false;
1030
1031     if (pid == gdb_get_cpu_pid(gdbserver_state.c_cpu)) {
1032         gdbserver_state.c_cpu = gdb_first_attached_cpu();
1033     }
1034
1035     if (pid == gdb_get_cpu_pid(gdbserver_state.g_cpu)) {
1036         gdbserver_state.g_cpu = gdb_first_attached_cpu();
1037     }
1038
1039     if (!gdbserver_state.c_cpu) {
1040         /* No more process attached */
1041         gdb_disable_syscalls();
1042         gdb_continue();
1043     }
1044     gdb_put_packet("OK");
1045 }
1046
1047 static void handle_thread_alive(GArray *params, void *user_ctx)
1048 {
1049     CPUState *cpu;
1050
1051     if (!params->len) {
1052         gdb_put_packet("E22");
1053         return;
1054     }
1055
1056     if (get_param(params, 0)->thread_id.kind == GDB_READ_THREAD_ERR) {
1057         gdb_put_packet("E22");
1058         return;
1059     }
1060
1061     cpu = gdb_get_cpu(get_param(params, 0)->thread_id.pid,
1062                       get_param(params, 0)->thread_id.tid);
1063     if (!cpu) {
1064         gdb_put_packet("E22");
1065         return;
1066     }
1067
1068     gdb_put_packet("OK");
1069 }
1070
1071 static void handle_continue(GArray *params, void *user_ctx)
1072 {
1073     if (params->len) {
1074         gdb_set_cpu_pc(get_param(params, 0)->val_ull);
1075     }
1076
1077     gdbserver_state.signal = 0;
1078     gdb_continue();
1079 }
1080
1081 static void handle_cont_with_sig(GArray *params, void *user_ctx)
1082 {
1083     unsigned long signal = 0;
1084
1085     /*
1086      * Note: C sig;[addr] is currently unsupported and we simply
1087      *       omit the addr parameter
1088      */
1089     if (params->len) {
1090         signal = get_param(params, 0)->val_ul;
1091     }
1092
1093     gdbserver_state.signal = gdb_signal_to_target(signal);
1094     if (gdbserver_state.signal == -1) {
1095         gdbserver_state.signal = 0;
1096     }
1097     gdb_continue();
1098 }
1099
1100 static void handle_set_thread(GArray *params, void *user_ctx)
1101 {
1102     CPUState *cpu;
1103
1104     if (params->len != 2) {
1105         gdb_put_packet("E22");
1106         return;
1107     }
1108
1109     if (get_param(params, 1)->thread_id.kind == GDB_READ_THREAD_ERR) {
1110         gdb_put_packet("E22");
1111         return;
1112     }
1113
1114     if (get_param(params, 1)->thread_id.kind != GDB_ONE_THREAD) {
1115         gdb_put_packet("OK");
1116         return;
1117     }
1118
1119     cpu = gdb_get_cpu(get_param(params, 1)->thread_id.pid,
1120                       get_param(params, 1)->thread_id.tid);
1121     if (!cpu) {
1122         gdb_put_packet("E22");
1123         return;
1124     }
1125
1126     /*
1127      * Note: This command is deprecated and modern gdb's will be using the
1128      *       vCont command instead.
1129      */
1130     switch (get_param(params, 0)->opcode) {
1131     case 'c':
1132         gdbserver_state.c_cpu = cpu;
1133         gdb_put_packet("OK");
1134         break;
1135     case 'g':
1136         gdbserver_state.g_cpu = cpu;
1137         gdb_put_packet("OK");
1138         break;
1139     default:
1140         gdb_put_packet("E22");
1141         break;
1142     }
1143 }
1144
1145 static void handle_insert_bp(GArray *params, void *user_ctx)
1146 {
1147     int res;
1148
1149     if (params->len != 3) {
1150         gdb_put_packet("E22");
1151         return;
1152     }
1153
1154     res = gdb_breakpoint_insert(gdbserver_state.c_cpu,
1155                                 get_param(params, 0)->val_ul,
1156                                 get_param(params, 1)->val_ull,
1157                                 get_param(params, 2)->val_ull);
1158     if (res >= 0) {
1159         gdb_put_packet("OK");
1160         return;
1161     } else if (res == -ENOSYS) {
1162         gdb_put_packet("");
1163         return;
1164     }
1165
1166     gdb_put_packet("E22");
1167 }
1168
1169 static void handle_remove_bp(GArray *params, void *user_ctx)
1170 {
1171     int res;
1172
1173     if (params->len != 3) {
1174         gdb_put_packet("E22");
1175         return;
1176     }
1177
1178     res = gdb_breakpoint_remove(gdbserver_state.c_cpu,
1179                                 get_param(params, 0)->val_ul,
1180                                 get_param(params, 1)->val_ull,
1181                                 get_param(params, 2)->val_ull);
1182     if (res >= 0) {
1183         gdb_put_packet("OK");
1184         return;
1185     } else if (res == -ENOSYS) {
1186         gdb_put_packet("");
1187         return;
1188     }
1189
1190     gdb_put_packet("E22");
1191 }
1192
1193 /*
1194  * handle_set/get_reg
1195  *
1196  * Older gdb are really dumb, and don't use 'G/g' if 'P/p' is available.
1197  * This works, but can be very slow. Anything new enough to understand
1198  * XML also knows how to use this properly. However to use this we
1199  * need to define a local XML file as well as be talking to a
1200  * reasonably modern gdb. Responding with an empty packet will cause
1201  * the remote gdb to fallback to older methods.
1202  */
1203
1204 static void handle_set_reg(GArray *params, void *user_ctx)
1205 {
1206     int reg_size;
1207
1208     if (params->len != 2) {
1209         gdb_put_packet("E22");
1210         return;
1211     }
1212
1213     reg_size = strlen(get_param(params, 1)->data) / 2;
1214     gdb_hextomem(gdbserver_state.mem_buf, get_param(params, 1)->data, reg_size);
1215     gdb_write_register(gdbserver_state.g_cpu, gdbserver_state.mem_buf->data,
1216                        get_param(params, 0)->val_ull);
1217     gdb_put_packet("OK");
1218 }
1219
1220 static void handle_get_reg(GArray *params, void *user_ctx)
1221 {
1222     int reg_size;
1223
1224     if (!params->len) {
1225         gdb_put_packet("E14");
1226         return;
1227     }
1228
1229     reg_size = gdb_read_register(gdbserver_state.g_cpu,
1230                                  gdbserver_state.mem_buf,
1231                                  get_param(params, 0)->val_ull);
1232     if (!reg_size) {
1233         gdb_put_packet("E14");
1234         return;
1235     } else {
1236         g_byte_array_set_size(gdbserver_state.mem_buf, reg_size);
1237     }
1238
1239     gdb_memtohex(gdbserver_state.str_buf,
1240                  gdbserver_state.mem_buf->data, reg_size);
1241     gdb_put_strbuf();
1242 }
1243
1244 static void handle_write_mem(GArray *params, void *user_ctx)
1245 {
1246     if (params->len != 3) {
1247         gdb_put_packet("E22");
1248         return;
1249     }
1250
1251     /* gdb_hextomem() reads 2*len bytes */
1252     if (get_param(params, 1)->val_ull >
1253         strlen(get_param(params, 2)->data) / 2) {
1254         gdb_put_packet("E22");
1255         return;
1256     }
1257
1258     gdb_hextomem(gdbserver_state.mem_buf, get_param(params, 2)->data,
1259                  get_param(params, 1)->val_ull);
1260     if (gdb_target_memory_rw_debug(gdbserver_state.g_cpu,
1261                                    get_param(params, 0)->val_ull,
1262                                    gdbserver_state.mem_buf->data,
1263                                    gdbserver_state.mem_buf->len, true)) {
1264         gdb_put_packet("E14");
1265         return;
1266     }
1267
1268     gdb_put_packet("OK");
1269 }
1270
1271 static void handle_read_mem(GArray *params, void *user_ctx)
1272 {
1273     if (params->len != 2) {
1274         gdb_put_packet("E22");
1275         return;
1276     }
1277
1278     /* gdb_memtohex() doubles the required space */
1279     if (get_param(params, 1)->val_ull > MAX_PACKET_LENGTH / 2) {
1280         gdb_put_packet("E22");
1281         return;
1282     }
1283
1284     g_byte_array_set_size(gdbserver_state.mem_buf,
1285                           get_param(params, 1)->val_ull);
1286
1287     if (gdb_target_memory_rw_debug(gdbserver_state.g_cpu,
1288                                    get_param(params, 0)->val_ull,
1289                                    gdbserver_state.mem_buf->data,
1290                                    gdbserver_state.mem_buf->len, false)) {
1291         gdb_put_packet("E14");
1292         return;
1293     }
1294
1295     gdb_memtohex(gdbserver_state.str_buf, gdbserver_state.mem_buf->data,
1296              gdbserver_state.mem_buf->len);
1297     gdb_put_strbuf();
1298 }
1299
1300 static void handle_write_all_regs(GArray *params, void *user_ctx)
1301 {
1302     int reg_id;
1303     size_t len;
1304     uint8_t *registers;
1305     int reg_size;
1306
1307     if (!params->len) {
1308         return;
1309     }
1310
1311     cpu_synchronize_state(gdbserver_state.g_cpu);
1312     len = strlen(get_param(params, 0)->data) / 2;
1313     gdb_hextomem(gdbserver_state.mem_buf, get_param(params, 0)->data, len);
1314     registers = gdbserver_state.mem_buf->data;
1315     for (reg_id = 0;
1316          reg_id < gdbserver_state.g_cpu->gdb_num_g_regs && len > 0;
1317          reg_id++) {
1318         reg_size = gdb_write_register(gdbserver_state.g_cpu, registers, reg_id);
1319         len -= reg_size;
1320         registers += reg_size;
1321     }
1322     gdb_put_packet("OK");
1323 }
1324
1325 static void handle_read_all_regs(GArray *params, void *user_ctx)
1326 {
1327     int reg_id;
1328     size_t len;
1329
1330     cpu_synchronize_state(gdbserver_state.g_cpu);
1331     g_byte_array_set_size(gdbserver_state.mem_buf, 0);
1332     len = 0;
1333     for (reg_id = 0; reg_id < gdbserver_state.g_cpu->gdb_num_g_regs; reg_id++) {
1334         len += gdb_read_register(gdbserver_state.g_cpu,
1335                                  gdbserver_state.mem_buf,
1336                                  reg_id);
1337     }
1338     g_assert(len == gdbserver_state.mem_buf->len);
1339
1340     gdb_memtohex(gdbserver_state.str_buf, gdbserver_state.mem_buf->data, len);
1341     gdb_put_strbuf();
1342 }
1343
1344
1345 static void handle_step(GArray *params, void *user_ctx)
1346 {
1347     if (params->len) {
1348         gdb_set_cpu_pc(get_param(params, 0)->val_ull);
1349     }
1350
1351     cpu_single_step(gdbserver_state.c_cpu, gdbserver_state.sstep_flags);
1352     gdb_continue();
1353 }
1354
1355 static void handle_backward(GArray *params, void *user_ctx)
1356 {
1357     if (!gdb_can_reverse()) {
1358         gdb_put_packet("E22");
1359     }
1360     if (params->len == 1) {
1361         switch (get_param(params, 0)->opcode) {
1362         case 's':
1363             if (replay_reverse_step()) {
1364                 gdb_continue();
1365             } else {
1366                 gdb_put_packet("E14");
1367             }
1368             return;
1369         case 'c':
1370             if (replay_reverse_continue()) {
1371                 gdb_continue();
1372             } else {
1373                 gdb_put_packet("E14");
1374             }
1375             return;
1376         }
1377     }
1378
1379     /* Default invalid command */
1380     gdb_put_packet("");
1381 }
1382
1383 static void handle_v_cont_query(GArray *params, void *user_ctx)
1384 {
1385     gdb_put_packet("vCont;c;C;s;S");
1386 }
1387
1388 static void handle_v_cont(GArray *params, void *user_ctx)
1389 {
1390     int res;
1391
1392     if (!params->len) {
1393         return;
1394     }
1395
1396     res = gdb_handle_vcont(get_param(params, 0)->data);
1397     if ((res == -EINVAL) || (res == -ERANGE)) {
1398         gdb_put_packet("E22");
1399     } else if (res) {
1400         gdb_put_packet("");
1401     }
1402 }
1403
1404 static void handle_v_attach(GArray *params, void *user_ctx)
1405 {
1406     GDBProcess *process;
1407     CPUState *cpu;
1408
1409     g_string_assign(gdbserver_state.str_buf, "E22");
1410     if (!params->len) {
1411         goto cleanup;
1412     }
1413
1414     process = gdb_get_process(get_param(params, 0)->val_ul);
1415     if (!process) {
1416         goto cleanup;
1417     }
1418
1419     cpu = gdb_get_first_cpu_in_process(process);
1420     if (!cpu) {
1421         goto cleanup;
1422     }
1423
1424     process->attached = true;
1425     gdbserver_state.g_cpu = cpu;
1426     gdbserver_state.c_cpu = cpu;
1427
1428     if (gdbserver_state.allow_stop_reply) {
1429         g_string_printf(gdbserver_state.str_buf, "T%02xthread:", GDB_SIGNAL_TRAP);
1430         gdb_append_thread_id(cpu, gdbserver_state.str_buf);
1431         g_string_append_c(gdbserver_state.str_buf, ';');
1432         gdbserver_state.allow_stop_reply = false;
1433 cleanup:
1434         gdb_put_strbuf();
1435     }
1436 }
1437
1438 static void handle_v_kill(GArray *params, void *user_ctx)
1439 {
1440     /* Kill the target */
1441     gdb_put_packet("OK");
1442     error_report("QEMU: Terminated via GDBstub");
1443     gdb_exit(0);
1444     gdb_qemu_exit(0);
1445 }
1446
1447 static const GdbCmdParseEntry gdb_v_commands_table[] = {
1448     /* Order is important if has same prefix */
1449     {
1450         .handler = handle_v_cont_query,
1451         .cmd = "Cont?",
1452         .cmd_startswith = 1
1453     },
1454     {
1455         .handler = handle_v_cont,
1456         .cmd = "Cont",
1457         .cmd_startswith = 1,
1458         .allow_stop_reply = true,
1459         .schema = "s0"
1460     },
1461     {
1462         .handler = handle_v_attach,
1463         .cmd = "Attach;",
1464         .cmd_startswith = 1,
1465         .allow_stop_reply = true,
1466         .schema = "l0"
1467     },
1468     {
1469         .handler = handle_v_kill,
1470         .cmd = "Kill;",
1471         .cmd_startswith = 1
1472     },
1473 #ifdef CONFIG_USER_ONLY
1474     /*
1475      * Host I/O Packets. See [1] for details.
1476      * [1] https://sourceware.org/gdb/onlinedocs/gdb/Host-I_002fO-Packets.html
1477      */
1478     {
1479         .handler = gdb_handle_v_file_open,
1480         .cmd = "File:open:",
1481         .cmd_startswith = 1,
1482         .schema = "s,L,L0"
1483     },
1484     {
1485         .handler = gdb_handle_v_file_close,
1486         .cmd = "File:close:",
1487         .cmd_startswith = 1,
1488         .schema = "l0"
1489     },
1490     {
1491         .handler = gdb_handle_v_file_pread,
1492         .cmd = "File:pread:",
1493         .cmd_startswith = 1,
1494         .schema = "l,L,L0"
1495     },
1496     {
1497         .handler = gdb_handle_v_file_readlink,
1498         .cmd = "File:readlink:",
1499         .cmd_startswith = 1,
1500         .schema = "s0"
1501     },
1502 #endif
1503 };
1504
1505 static void handle_v_commands(GArray *params, void *user_ctx)
1506 {
1507     if (!params->len) {
1508         return;
1509     }
1510
1511     if (process_string_cmd(get_param(params, 0)->data,
1512                            gdb_v_commands_table,
1513                            ARRAY_SIZE(gdb_v_commands_table))) {
1514         gdb_put_packet("");
1515     }
1516 }
1517
1518 static void handle_query_qemu_sstepbits(GArray *params, void *user_ctx)
1519 {
1520     g_string_printf(gdbserver_state.str_buf, "ENABLE=%x", SSTEP_ENABLE);
1521
1522     if (gdbserver_state.supported_sstep_flags & SSTEP_NOIRQ) {
1523         g_string_append_printf(gdbserver_state.str_buf, ",NOIRQ=%x",
1524                                SSTEP_NOIRQ);
1525     }
1526
1527     if (gdbserver_state.supported_sstep_flags & SSTEP_NOTIMER) {
1528         g_string_append_printf(gdbserver_state.str_buf, ",NOTIMER=%x",
1529                                SSTEP_NOTIMER);
1530     }
1531
1532     gdb_put_strbuf();
1533 }
1534
1535 static void handle_set_qemu_sstep(GArray *params, void *user_ctx)
1536 {
1537     int new_sstep_flags;
1538
1539     if (!params->len) {
1540         return;
1541     }
1542
1543     new_sstep_flags = get_param(params, 0)->val_ul;
1544
1545     if (new_sstep_flags  & ~gdbserver_state.supported_sstep_flags) {
1546         gdb_put_packet("E22");
1547         return;
1548     }
1549
1550     gdbserver_state.sstep_flags = new_sstep_flags;
1551     gdb_put_packet("OK");
1552 }
1553
1554 static void handle_query_qemu_sstep(GArray *params, void *user_ctx)
1555 {
1556     g_string_printf(gdbserver_state.str_buf, "0x%x",
1557                     gdbserver_state.sstep_flags);
1558     gdb_put_strbuf();
1559 }
1560
1561 static void handle_query_curr_tid(GArray *params, void *user_ctx)
1562 {
1563     CPUState *cpu;
1564     GDBProcess *process;
1565
1566     /*
1567      * "Current thread" remains vague in the spec, so always return
1568      * the first thread of the current process (gdb returns the
1569      * first thread).
1570      */
1571     process = gdb_get_cpu_process(gdbserver_state.g_cpu);
1572     cpu = gdb_get_first_cpu_in_process(process);
1573     g_string_assign(gdbserver_state.str_buf, "QC");
1574     gdb_append_thread_id(cpu, gdbserver_state.str_buf);
1575     gdb_put_strbuf();
1576 }
1577
1578 static void handle_query_threads(GArray *params, void *user_ctx)
1579 {
1580     if (!gdbserver_state.query_cpu) {
1581         gdb_put_packet("l");
1582         return;
1583     }
1584
1585     g_string_assign(gdbserver_state.str_buf, "m");
1586     gdb_append_thread_id(gdbserver_state.query_cpu, gdbserver_state.str_buf);
1587     gdb_put_strbuf();
1588     gdbserver_state.query_cpu = gdb_next_attached_cpu(gdbserver_state.query_cpu);
1589 }
1590
1591 static void handle_query_first_threads(GArray *params, void *user_ctx)
1592 {
1593     gdbserver_state.query_cpu = gdb_first_attached_cpu();
1594     handle_query_threads(params, user_ctx);
1595 }
1596
1597 static void handle_query_thread_extra(GArray *params, void *user_ctx)
1598 {
1599     g_autoptr(GString) rs = g_string_new(NULL);
1600     CPUState *cpu;
1601
1602     if (!params->len ||
1603         get_param(params, 0)->thread_id.kind == GDB_READ_THREAD_ERR) {
1604         gdb_put_packet("E22");
1605         return;
1606     }
1607
1608     cpu = gdb_get_cpu(get_param(params, 0)->thread_id.pid,
1609                       get_param(params, 0)->thread_id.tid);
1610     if (!cpu) {
1611         return;
1612     }
1613
1614     cpu_synchronize_state(cpu);
1615
1616     if (gdbserver_state.multiprocess && (gdbserver_state.process_num > 1)) {
1617         /* Print the CPU model and name in multiprocess mode */
1618         ObjectClass *oc = object_get_class(OBJECT(cpu));
1619         const char *cpu_model = object_class_get_name(oc);
1620         const char *cpu_name =
1621             object_get_canonical_path_component(OBJECT(cpu));
1622         g_string_printf(rs, "%s %s [%s]", cpu_model, cpu_name,
1623                         cpu->halted ? "halted " : "running");
1624     } else {
1625         g_string_printf(rs, "CPU#%d [%s]", cpu->cpu_index,
1626                         cpu->halted ? "halted " : "running");
1627     }
1628     trace_gdbstub_op_extra_info(rs->str);
1629     gdb_memtohex(gdbserver_state.str_buf, (uint8_t *)rs->str, rs->len);
1630     gdb_put_strbuf();
1631 }
1632
1633 static void handle_query_supported(GArray *params, void *user_ctx)
1634 {
1635     CPUClass *cc;
1636
1637     g_string_printf(gdbserver_state.str_buf, "PacketSize=%x", MAX_PACKET_LENGTH);
1638     cc = CPU_GET_CLASS(first_cpu);
1639     if (cc->gdb_core_xml_file) {
1640         g_string_append(gdbserver_state.str_buf, ";qXfer:features:read+");
1641     }
1642
1643     if (gdb_can_reverse()) {
1644         g_string_append(gdbserver_state.str_buf,
1645             ";ReverseStep+;ReverseContinue+");
1646     }
1647
1648 #if defined(CONFIG_USER_ONLY)
1649 #if defined(CONFIG_LINUX)
1650     if (gdbserver_state.c_cpu->opaque) {
1651         g_string_append(gdbserver_state.str_buf, ";qXfer:auxv:read+");
1652     }
1653     g_string_append(gdbserver_state.str_buf, ";QCatchSyscalls+");
1654 #endif
1655     g_string_append(gdbserver_state.str_buf, ";qXfer:exec-file:read+");
1656 #endif
1657
1658     if (params->len &&
1659         strstr(get_param(params, 0)->data, "multiprocess+")) {
1660         gdbserver_state.multiprocess = true;
1661     }
1662
1663     g_string_append(gdbserver_state.str_buf, ";vContSupported+;multiprocess+");
1664     gdb_put_strbuf();
1665 }
1666
1667 static void handle_query_xfer_features(GArray *params, void *user_ctx)
1668 {
1669     GDBProcess *process;
1670     CPUClass *cc;
1671     unsigned long len, total_len, addr;
1672     const char *xml;
1673     const char *p;
1674
1675     if (params->len < 3) {
1676         gdb_put_packet("E22");
1677         return;
1678     }
1679
1680     process = gdb_get_cpu_process(gdbserver_state.g_cpu);
1681     cc = CPU_GET_CLASS(gdbserver_state.g_cpu);
1682     if (!cc->gdb_core_xml_file) {
1683         gdb_put_packet("");
1684         return;
1685     }
1686
1687     p = get_param(params, 0)->data;
1688     xml = get_feature_xml(p, &p, process);
1689     if (!xml) {
1690         gdb_put_packet("E00");
1691         return;
1692     }
1693
1694     addr = get_param(params, 1)->val_ul;
1695     len = get_param(params, 2)->val_ul;
1696     total_len = strlen(xml);
1697     if (addr > total_len) {
1698         gdb_put_packet("E00");
1699         return;
1700     }
1701
1702     if (len > (MAX_PACKET_LENGTH - 5) / 2) {
1703         len = (MAX_PACKET_LENGTH - 5) / 2;
1704     }
1705
1706     if (len < total_len - addr) {
1707         g_string_assign(gdbserver_state.str_buf, "m");
1708         gdb_memtox(gdbserver_state.str_buf, xml + addr, len);
1709     } else {
1710         g_string_assign(gdbserver_state.str_buf, "l");
1711         gdb_memtox(gdbserver_state.str_buf, xml + addr, total_len - addr);
1712     }
1713
1714     gdb_put_packet_binary(gdbserver_state.str_buf->str,
1715                       gdbserver_state.str_buf->len, true);
1716 }
1717
1718 static void handle_query_qemu_supported(GArray *params, void *user_ctx)
1719 {
1720     g_string_printf(gdbserver_state.str_buf, "sstepbits;sstep");
1721 #ifndef CONFIG_USER_ONLY
1722     g_string_append(gdbserver_state.str_buf, ";PhyMemMode");
1723 #endif
1724     gdb_put_strbuf();
1725 }
1726
1727 static const GdbCmdParseEntry gdb_gen_query_set_common_table[] = {
1728     /* Order is important if has same prefix */
1729     {
1730         .handler = handle_query_qemu_sstepbits,
1731         .cmd = "qemu.sstepbits",
1732     },
1733     {
1734         .handler = handle_query_qemu_sstep,
1735         .cmd = "qemu.sstep",
1736     },
1737     {
1738         .handler = handle_set_qemu_sstep,
1739         .cmd = "qemu.sstep=",
1740         .cmd_startswith = 1,
1741         .schema = "l0"
1742     },
1743 };
1744
1745 static const GdbCmdParseEntry gdb_gen_query_table[] = {
1746     {
1747         .handler = handle_query_curr_tid,
1748         .cmd = "C",
1749     },
1750     {
1751         .handler = handle_query_threads,
1752         .cmd = "sThreadInfo",
1753     },
1754     {
1755         .handler = handle_query_first_threads,
1756         .cmd = "fThreadInfo",
1757     },
1758     {
1759         .handler = handle_query_thread_extra,
1760         .cmd = "ThreadExtraInfo,",
1761         .cmd_startswith = 1,
1762         .schema = "t0"
1763     },
1764 #ifdef CONFIG_USER_ONLY
1765     {
1766         .handler = gdb_handle_query_offsets,
1767         .cmd = "Offsets",
1768     },
1769 #else
1770     {
1771         .handler = gdb_handle_query_rcmd,
1772         .cmd = "Rcmd,",
1773         .cmd_startswith = 1,
1774         .schema = "s0"
1775     },
1776 #endif
1777     {
1778         .handler = handle_query_supported,
1779         .cmd = "Supported:",
1780         .cmd_startswith = 1,
1781         .schema = "s0"
1782     },
1783     {
1784         .handler = handle_query_supported,
1785         .cmd = "Supported",
1786         .schema = "s0"
1787     },
1788     {
1789         .handler = handle_query_xfer_features,
1790         .cmd = "Xfer:features:read:",
1791         .cmd_startswith = 1,
1792         .schema = "s:l,l0"
1793     },
1794 #if defined(CONFIG_USER_ONLY)
1795 #if defined(CONFIG_LINUX)
1796     {
1797         .handler = gdb_handle_query_xfer_auxv,
1798         .cmd = "Xfer:auxv:read::",
1799         .cmd_startswith = 1,
1800         .schema = "l,l0"
1801     },
1802 #endif
1803     {
1804         .handler = gdb_handle_query_xfer_exec_file,
1805         .cmd = "Xfer:exec-file:read:",
1806         .cmd_startswith = 1,
1807         .schema = "l:l,l0"
1808     },
1809 #endif
1810     {
1811         .handler = gdb_handle_query_attached,
1812         .cmd = "Attached:",
1813         .cmd_startswith = 1
1814     },
1815     {
1816         .handler = gdb_handle_query_attached,
1817         .cmd = "Attached",
1818     },
1819     {
1820         .handler = handle_query_qemu_supported,
1821         .cmd = "qemu.Supported",
1822     },
1823 #ifndef CONFIG_USER_ONLY
1824     {
1825         .handler = gdb_handle_query_qemu_phy_mem_mode,
1826         .cmd = "qemu.PhyMemMode",
1827     },
1828 #endif
1829 };
1830
1831 static const GdbCmdParseEntry gdb_gen_set_table[] = {
1832     /* Order is important if has same prefix */
1833     {
1834         .handler = handle_set_qemu_sstep,
1835         .cmd = "qemu.sstep:",
1836         .cmd_startswith = 1,
1837         .schema = "l0"
1838     },
1839 #ifndef CONFIG_USER_ONLY
1840     {
1841         .handler = gdb_handle_set_qemu_phy_mem_mode,
1842         .cmd = "qemu.PhyMemMode:",
1843         .cmd_startswith = 1,
1844         .schema = "l0"
1845     },
1846 #endif
1847 #if defined(CONFIG_USER_ONLY)
1848     {
1849         .handler = gdb_handle_set_catch_syscalls,
1850         .cmd = "CatchSyscalls:",
1851         .cmd_startswith = 1,
1852         .schema = "s0",
1853     },
1854 #endif
1855 };
1856
1857 static void handle_gen_query(GArray *params, void *user_ctx)
1858 {
1859     if (!params->len) {
1860         return;
1861     }
1862
1863     if (!process_string_cmd(get_param(params, 0)->data,
1864                             gdb_gen_query_set_common_table,
1865                             ARRAY_SIZE(gdb_gen_query_set_common_table))) {
1866         return;
1867     }
1868
1869     if (process_string_cmd(get_param(params, 0)->data,
1870                            gdb_gen_query_table,
1871                            ARRAY_SIZE(gdb_gen_query_table))) {
1872         gdb_put_packet("");
1873     }
1874 }
1875
1876 static void handle_gen_set(GArray *params, void *user_ctx)
1877 {
1878     if (!params->len) {
1879         return;
1880     }
1881
1882     if (!process_string_cmd(get_param(params, 0)->data,
1883                             gdb_gen_query_set_common_table,
1884                             ARRAY_SIZE(gdb_gen_query_set_common_table))) {
1885         return;
1886     }
1887
1888     if (process_string_cmd(get_param(params, 0)->data,
1889                            gdb_gen_set_table,
1890                            ARRAY_SIZE(gdb_gen_set_table))) {
1891         gdb_put_packet("");
1892     }
1893 }
1894
1895 static void handle_target_halt(GArray *params, void *user_ctx)
1896 {
1897     if (gdbserver_state.allow_stop_reply) {
1898         g_string_printf(gdbserver_state.str_buf, "T%02xthread:", GDB_SIGNAL_TRAP);
1899         gdb_append_thread_id(gdbserver_state.c_cpu, gdbserver_state.str_buf);
1900         g_string_append_c(gdbserver_state.str_buf, ';');
1901         gdb_put_strbuf();
1902         gdbserver_state.allow_stop_reply = false;
1903     }
1904     /*
1905      * Remove all the breakpoints when this query is issued,
1906      * because gdb is doing an initial connect and the state
1907      * should be cleaned up.
1908      */
1909     gdb_breakpoint_remove_all(gdbserver_state.c_cpu);
1910 }
1911
1912 static int gdb_handle_packet(const char *line_buf)
1913 {
1914     const GdbCmdParseEntry *cmd_parser = NULL;
1915
1916     trace_gdbstub_io_command(line_buf);
1917
1918     switch (line_buf[0]) {
1919     case '!':
1920         gdb_put_packet("OK");
1921         break;
1922     case '?':
1923         {
1924             static const GdbCmdParseEntry target_halted_cmd_desc = {
1925                 .handler = handle_target_halt,
1926                 .cmd = "?",
1927                 .cmd_startswith = 1,
1928                 .allow_stop_reply = true,
1929             };
1930             cmd_parser = &target_halted_cmd_desc;
1931         }
1932         break;
1933     case 'c':
1934         {
1935             static const GdbCmdParseEntry continue_cmd_desc = {
1936                 .handler = handle_continue,
1937                 .cmd = "c",
1938                 .cmd_startswith = 1,
1939                 .allow_stop_reply = true,
1940                 .schema = "L0"
1941             };
1942             cmd_parser = &continue_cmd_desc;
1943         }
1944         break;
1945     case 'C':
1946         {
1947             static const GdbCmdParseEntry cont_with_sig_cmd_desc = {
1948                 .handler = handle_cont_with_sig,
1949                 .cmd = "C",
1950                 .cmd_startswith = 1,
1951                 .allow_stop_reply = true,
1952                 .schema = "l0"
1953             };
1954             cmd_parser = &cont_with_sig_cmd_desc;
1955         }
1956         break;
1957     case 'v':
1958         {
1959             static const GdbCmdParseEntry v_cmd_desc = {
1960                 .handler = handle_v_commands,
1961                 .cmd = "v",
1962                 .cmd_startswith = 1,
1963                 .schema = "s0"
1964             };
1965             cmd_parser = &v_cmd_desc;
1966         }
1967         break;
1968     case 'k':
1969         /* Kill the target */
1970         error_report("QEMU: Terminated via GDBstub");
1971         gdb_exit(0);
1972         gdb_qemu_exit(0);
1973         break;
1974     case 'D':
1975         {
1976             static const GdbCmdParseEntry detach_cmd_desc = {
1977                 .handler = handle_detach,
1978                 .cmd = "D",
1979                 .cmd_startswith = 1,
1980                 .schema = "?.l0"
1981             };
1982             cmd_parser = &detach_cmd_desc;
1983         }
1984         break;
1985     case 's':
1986         {
1987             static const GdbCmdParseEntry step_cmd_desc = {
1988                 .handler = handle_step,
1989                 .cmd = "s",
1990                 .cmd_startswith = 1,
1991                 .allow_stop_reply = true,
1992                 .schema = "L0"
1993             };
1994             cmd_parser = &step_cmd_desc;
1995         }
1996         break;
1997     case 'b':
1998         {
1999             static const GdbCmdParseEntry backward_cmd_desc = {
2000                 .handler = handle_backward,
2001                 .cmd = "b",
2002                 .cmd_startswith = 1,
2003                 .allow_stop_reply = true,
2004                 .schema = "o0"
2005             };
2006             cmd_parser = &backward_cmd_desc;
2007         }
2008         break;
2009     case 'F':
2010         {
2011             static const GdbCmdParseEntry file_io_cmd_desc = {
2012                 .handler = gdb_handle_file_io,
2013                 .cmd = "F",
2014                 .cmd_startswith = 1,
2015                 .schema = "L,L,o0"
2016             };
2017             cmd_parser = &file_io_cmd_desc;
2018         }
2019         break;
2020     case 'g':
2021         {
2022             static const GdbCmdParseEntry read_all_regs_cmd_desc = {
2023                 .handler = handle_read_all_regs,
2024                 .cmd = "g",
2025                 .cmd_startswith = 1
2026             };
2027             cmd_parser = &read_all_regs_cmd_desc;
2028         }
2029         break;
2030     case 'G':
2031         {
2032             static const GdbCmdParseEntry write_all_regs_cmd_desc = {
2033                 .handler = handle_write_all_regs,
2034                 .cmd = "G",
2035                 .cmd_startswith = 1,
2036                 .schema = "s0"
2037             };
2038             cmd_parser = &write_all_regs_cmd_desc;
2039         }
2040         break;
2041     case 'm':
2042         {
2043             static const GdbCmdParseEntry read_mem_cmd_desc = {
2044                 .handler = handle_read_mem,
2045                 .cmd = "m",
2046                 .cmd_startswith = 1,
2047                 .schema = "L,L0"
2048             };
2049             cmd_parser = &read_mem_cmd_desc;
2050         }
2051         break;
2052     case 'M':
2053         {
2054             static const GdbCmdParseEntry write_mem_cmd_desc = {
2055                 .handler = handle_write_mem,
2056                 .cmd = "M",
2057                 .cmd_startswith = 1,
2058                 .schema = "L,L:s0"
2059             };
2060             cmd_parser = &write_mem_cmd_desc;
2061         }
2062         break;
2063     case 'p':
2064         {
2065             static const GdbCmdParseEntry get_reg_cmd_desc = {
2066                 .handler = handle_get_reg,
2067                 .cmd = "p",
2068                 .cmd_startswith = 1,
2069                 .schema = "L0"
2070             };
2071             cmd_parser = &get_reg_cmd_desc;
2072         }
2073         break;
2074     case 'P':
2075         {
2076             static const GdbCmdParseEntry set_reg_cmd_desc = {
2077                 .handler = handle_set_reg,
2078                 .cmd = "P",
2079                 .cmd_startswith = 1,
2080                 .schema = "L?s0"
2081             };
2082             cmd_parser = &set_reg_cmd_desc;
2083         }
2084         break;
2085     case 'Z':
2086         {
2087             static const GdbCmdParseEntry insert_bp_cmd_desc = {
2088                 .handler = handle_insert_bp,
2089                 .cmd = "Z",
2090                 .cmd_startswith = 1,
2091                 .schema = "l?L?L0"
2092             };
2093             cmd_parser = &insert_bp_cmd_desc;
2094         }
2095         break;
2096     case 'z':
2097         {
2098             static const GdbCmdParseEntry remove_bp_cmd_desc = {
2099                 .handler = handle_remove_bp,
2100                 .cmd = "z",
2101                 .cmd_startswith = 1,
2102                 .schema = "l?L?L0"
2103             };
2104             cmd_parser = &remove_bp_cmd_desc;
2105         }
2106         break;
2107     case 'H':
2108         {
2109             static const GdbCmdParseEntry set_thread_cmd_desc = {
2110                 .handler = handle_set_thread,
2111                 .cmd = "H",
2112                 .cmd_startswith = 1,
2113                 .schema = "o.t0"
2114             };
2115             cmd_parser = &set_thread_cmd_desc;
2116         }
2117         break;
2118     case 'T':
2119         {
2120             static const GdbCmdParseEntry thread_alive_cmd_desc = {
2121                 .handler = handle_thread_alive,
2122                 .cmd = "T",
2123                 .cmd_startswith = 1,
2124                 .schema = "t0"
2125             };
2126             cmd_parser = &thread_alive_cmd_desc;
2127         }
2128         break;
2129     case 'q':
2130         {
2131             static const GdbCmdParseEntry gen_query_cmd_desc = {
2132                 .handler = handle_gen_query,
2133                 .cmd = "q",
2134                 .cmd_startswith = 1,
2135                 .schema = "s0"
2136             };
2137             cmd_parser = &gen_query_cmd_desc;
2138         }
2139         break;
2140     case 'Q':
2141         {
2142             static const GdbCmdParseEntry gen_set_cmd_desc = {
2143                 .handler = handle_gen_set,
2144                 .cmd = "Q",
2145                 .cmd_startswith = 1,
2146                 .schema = "s0"
2147             };
2148             cmd_parser = &gen_set_cmd_desc;
2149         }
2150         break;
2151     default:
2152         /* put empty packet */
2153         gdb_put_packet("");
2154         break;
2155     }
2156
2157     if (cmd_parser) {
2158         run_cmd_parser(line_buf, cmd_parser);
2159     }
2160
2161     return RS_IDLE;
2162 }
2163
2164 void gdb_set_stop_cpu(CPUState *cpu)
2165 {
2166     GDBProcess *p = gdb_get_cpu_process(cpu);
2167
2168     if (!p->attached) {
2169         /*
2170          * Having a stop CPU corresponding to a process that is not attached
2171          * confuses GDB. So we ignore the request.
2172          */
2173         return;
2174     }
2175
2176     gdbserver_state.c_cpu = cpu;
2177     gdbserver_state.g_cpu = cpu;
2178 }
2179
2180 void gdb_read_byte(uint8_t ch)
2181 {
2182     uint8_t reply;
2183
2184     gdbserver_state.allow_stop_reply = false;
2185 #ifndef CONFIG_USER_ONLY
2186     if (gdbserver_state.last_packet->len) {
2187         /* Waiting for a response to the last packet.  If we see the start
2188            of a new command then abandon the previous response.  */
2189         if (ch == '-') {
2190             trace_gdbstub_err_got_nack();
2191             gdb_put_buffer(gdbserver_state.last_packet->data,
2192                        gdbserver_state.last_packet->len);
2193         } else if (ch == '+') {
2194             trace_gdbstub_io_got_ack();
2195         } else {
2196             trace_gdbstub_io_got_unexpected(ch);
2197         }
2198
2199         if (ch == '+' || ch == '$') {
2200             g_byte_array_set_size(gdbserver_state.last_packet, 0);
2201         }
2202         if (ch != '$')
2203             return;
2204     }
2205     if (runstate_is_running()) {
2206         /*
2207          * When the CPU is running, we cannot do anything except stop
2208          * it when receiving a char. This is expected on a Ctrl-C in the
2209          * gdb client. Because we are in all-stop mode, gdb sends a
2210          * 0x03 byte which is not a usual packet, so we handle it specially
2211          * here, but it does expect a stop reply.
2212          */
2213         if (ch != 0x03) {
2214             trace_gdbstub_err_unexpected_runpkt(ch);
2215         } else {
2216             gdbserver_state.allow_stop_reply = true;
2217         }
2218         vm_stop(RUN_STATE_PAUSED);
2219     } else
2220 #endif
2221     {
2222         switch(gdbserver_state.state) {
2223         case RS_IDLE:
2224             if (ch == '$') {
2225                 /* start of command packet */
2226                 gdbserver_state.line_buf_index = 0;
2227                 gdbserver_state.line_sum = 0;
2228                 gdbserver_state.state = RS_GETLINE;
2229             } else if (ch == '+') {
2230                 /*
2231                  * do nothing, gdb may preemptively send out ACKs on
2232                  * initial connection
2233                  */
2234             } else {
2235                 trace_gdbstub_err_garbage(ch);
2236             }
2237             break;
2238         case RS_GETLINE:
2239             if (ch == '}') {
2240                 /* start escape sequence */
2241                 gdbserver_state.state = RS_GETLINE_ESC;
2242                 gdbserver_state.line_sum += ch;
2243             } else if (ch == '*') {
2244                 /* start run length encoding sequence */
2245                 gdbserver_state.state = RS_GETLINE_RLE;
2246                 gdbserver_state.line_sum += ch;
2247             } else if (ch == '#') {
2248                 /* end of command, start of checksum*/
2249                 gdbserver_state.state = RS_CHKSUM1;
2250             } else if (gdbserver_state.line_buf_index >= sizeof(gdbserver_state.line_buf) - 1) {
2251                 trace_gdbstub_err_overrun();
2252                 gdbserver_state.state = RS_IDLE;
2253             } else {
2254                 /* unescaped command character */
2255                 gdbserver_state.line_buf[gdbserver_state.line_buf_index++] = ch;
2256                 gdbserver_state.line_sum += ch;
2257             }
2258             break;
2259         case RS_GETLINE_ESC:
2260             if (ch == '#') {
2261                 /* unexpected end of command in escape sequence */
2262                 gdbserver_state.state = RS_CHKSUM1;
2263             } else if (gdbserver_state.line_buf_index >= sizeof(gdbserver_state.line_buf) - 1) {
2264                 /* command buffer overrun */
2265                 trace_gdbstub_err_overrun();
2266                 gdbserver_state.state = RS_IDLE;
2267             } else {
2268                 /* parse escaped character and leave escape state */
2269                 gdbserver_state.line_buf[gdbserver_state.line_buf_index++] = ch ^ 0x20;
2270                 gdbserver_state.line_sum += ch;
2271                 gdbserver_state.state = RS_GETLINE;
2272             }
2273             break;
2274         case RS_GETLINE_RLE:
2275             /*
2276              * Run-length encoding is explained in "Debugging with GDB /
2277              * Appendix E GDB Remote Serial Protocol / Overview".
2278              */
2279             if (ch < ' ' || ch == '#' || ch == '$' || ch > 126) {
2280                 /* invalid RLE count encoding */
2281                 trace_gdbstub_err_invalid_repeat(ch);
2282                 gdbserver_state.state = RS_GETLINE;
2283             } else {
2284                 /* decode repeat length */
2285                 int repeat = ch - ' ' + 3;
2286                 if (gdbserver_state.line_buf_index + repeat >= sizeof(gdbserver_state.line_buf) - 1) {
2287                     /* that many repeats would overrun the command buffer */
2288                     trace_gdbstub_err_overrun();
2289                     gdbserver_state.state = RS_IDLE;
2290                 } else if (gdbserver_state.line_buf_index < 1) {
2291                     /* got a repeat but we have nothing to repeat */
2292                     trace_gdbstub_err_invalid_rle();
2293                     gdbserver_state.state = RS_GETLINE;
2294                 } else {
2295                     /* repeat the last character */
2296                     memset(gdbserver_state.line_buf + gdbserver_state.line_buf_index,
2297                            gdbserver_state.line_buf[gdbserver_state.line_buf_index - 1], repeat);
2298                     gdbserver_state.line_buf_index += repeat;
2299                     gdbserver_state.line_sum += ch;
2300                     gdbserver_state.state = RS_GETLINE;
2301                 }
2302             }
2303             break;
2304         case RS_CHKSUM1:
2305             /* get high hex digit of checksum */
2306             if (!isxdigit(ch)) {
2307                 trace_gdbstub_err_checksum_invalid(ch);
2308                 gdbserver_state.state = RS_GETLINE;
2309                 break;
2310             }
2311             gdbserver_state.line_buf[gdbserver_state.line_buf_index] = '\0';
2312             gdbserver_state.line_csum = fromhex(ch) << 4;
2313             gdbserver_state.state = RS_CHKSUM2;
2314             break;
2315         case RS_CHKSUM2:
2316             /* get low hex digit of checksum */
2317             if (!isxdigit(ch)) {
2318                 trace_gdbstub_err_checksum_invalid(ch);
2319                 gdbserver_state.state = RS_GETLINE;
2320                 break;
2321             }
2322             gdbserver_state.line_csum |= fromhex(ch);
2323
2324             if (gdbserver_state.line_csum != (gdbserver_state.line_sum & 0xff)) {
2325                 trace_gdbstub_err_checksum_incorrect(gdbserver_state.line_sum, gdbserver_state.line_csum);
2326                 /* send NAK reply */
2327                 reply = '-';
2328                 gdb_put_buffer(&reply, 1);
2329                 gdbserver_state.state = RS_IDLE;
2330             } else {
2331                 /* send ACK reply */
2332                 reply = '+';
2333                 gdb_put_buffer(&reply, 1);
2334                 gdbserver_state.state = gdb_handle_packet(gdbserver_state.line_buf);
2335             }
2336             break;
2337         default:
2338             abort();
2339         }
2340     }
2341 }
2342
2343 /*
2344  * Create the process that will contain all the "orphan" CPUs (that are not
2345  * part of a CPU cluster). Note that if this process contains no CPUs, it won't
2346  * be attachable and thus will be invisible to the user.
2347  */
2348 void gdb_create_default_process(GDBState *s)
2349 {
2350     GDBProcess *process;
2351     int pid;
2352
2353 #ifdef CONFIG_USER_ONLY
2354     assert(gdbserver_state.process_num == 0);
2355     pid = getpid();
2356 #else
2357     if (gdbserver_state.process_num) {
2358         pid = s->processes[s->process_num - 1].pid;
2359     } else {
2360         pid = 0;
2361     }
2362     /* We need an available PID slot for this process */
2363     assert(pid < UINT32_MAX);
2364     pid++;
2365 #endif
2366
2367     s->processes = g_renew(GDBProcess, s->processes, ++s->process_num);
2368     process = &s->processes[s->process_num - 1];
2369     process->pid = pid;
2370     process->attached = false;
2371     process->target_xml = NULL;
2372 }
2373