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 #ifdef CONFIG_USER_ONLY
1028     if (gdb_handle_detach_user(pid)) {
1029         return;
1030     }
1031 #endif
1032
1033     process = gdb_get_process(pid);
1034     gdb_process_breakpoint_remove_all(process);
1035     process->attached = false;
1036
1037     if (pid == gdb_get_cpu_pid(gdbserver_state.c_cpu)) {
1038         gdbserver_state.c_cpu = gdb_first_attached_cpu();
1039     }
1040
1041     if (pid == gdb_get_cpu_pid(gdbserver_state.g_cpu)) {
1042         gdbserver_state.g_cpu = gdb_first_attached_cpu();
1043     }
1044
1045     if (!gdbserver_state.c_cpu) {
1046         /* No more process attached */
1047         gdb_disable_syscalls();
1048         gdb_continue();
1049     }
1050     gdb_put_packet("OK");
1051 }
1052
1053 static void handle_thread_alive(GArray *params, void *user_ctx)
1054 {
1055     CPUState *cpu;
1056
1057     if (!params->len) {
1058         gdb_put_packet("E22");
1059         return;
1060     }
1061
1062     if (get_param(params, 0)->thread_id.kind == GDB_READ_THREAD_ERR) {
1063         gdb_put_packet("E22");
1064         return;
1065     }
1066
1067     cpu = gdb_get_cpu(get_param(params, 0)->thread_id.pid,
1068                       get_param(params, 0)->thread_id.tid);
1069     if (!cpu) {
1070         gdb_put_packet("E22");
1071         return;
1072     }
1073
1074     gdb_put_packet("OK");
1075 }
1076
1077 static void handle_continue(GArray *params, void *user_ctx)
1078 {
1079     if (params->len) {
1080         gdb_set_cpu_pc(get_param(params, 0)->val_ull);
1081     }
1082
1083     gdbserver_state.signal = 0;
1084     gdb_continue();
1085 }
1086
1087 static void handle_cont_with_sig(GArray *params, void *user_ctx)
1088 {
1089     unsigned long signal = 0;
1090
1091     /*
1092      * Note: C sig;[addr] is currently unsupported and we simply
1093      *       omit the addr parameter
1094      */
1095     if (params->len) {
1096         signal = get_param(params, 0)->val_ul;
1097     }
1098
1099     gdbserver_state.signal = gdb_signal_to_target(signal);
1100     if (gdbserver_state.signal == -1) {
1101         gdbserver_state.signal = 0;
1102     }
1103     gdb_continue();
1104 }
1105
1106 static void handle_set_thread(GArray *params, void *user_ctx)
1107 {
1108     uint32_t pid, tid;
1109     CPUState *cpu;
1110
1111     if (params->len != 2) {
1112         gdb_put_packet("E22");
1113         return;
1114     }
1115
1116     if (get_param(params, 1)->thread_id.kind == GDB_READ_THREAD_ERR) {
1117         gdb_put_packet("E22");
1118         return;
1119     }
1120
1121     if (get_param(params, 1)->thread_id.kind != GDB_ONE_THREAD) {
1122         gdb_put_packet("OK");
1123         return;
1124     }
1125
1126     pid = get_param(params, 1)->thread_id.pid;
1127     tid = get_param(params, 1)->thread_id.tid;
1128 #ifdef CONFIG_USER_ONLY
1129     if (gdb_handle_set_thread_user(pid, tid)) {
1130         return;
1131     }
1132 #endif
1133     cpu = gdb_get_cpu(pid, tid);
1134     if (!cpu) {
1135         gdb_put_packet("E22");
1136         return;
1137     }
1138
1139     /*
1140      * Note: This command is deprecated and modern gdb's will be using the
1141      *       vCont command instead.
1142      */
1143     switch (get_param(params, 0)->opcode) {
1144     case 'c':
1145         gdbserver_state.c_cpu = cpu;
1146         gdb_put_packet("OK");
1147         break;
1148     case 'g':
1149         gdbserver_state.g_cpu = cpu;
1150         gdb_put_packet("OK");
1151         break;
1152     default:
1153         gdb_put_packet("E22");
1154         break;
1155     }
1156 }
1157
1158 static void handle_insert_bp(GArray *params, void *user_ctx)
1159 {
1160     int res;
1161
1162     if (params->len != 3) {
1163         gdb_put_packet("E22");
1164         return;
1165     }
1166
1167     res = gdb_breakpoint_insert(gdbserver_state.c_cpu,
1168                                 get_param(params, 0)->val_ul,
1169                                 get_param(params, 1)->val_ull,
1170                                 get_param(params, 2)->val_ull);
1171     if (res >= 0) {
1172         gdb_put_packet("OK");
1173         return;
1174     } else if (res == -ENOSYS) {
1175         gdb_put_packet("");
1176         return;
1177     }
1178
1179     gdb_put_packet("E22");
1180 }
1181
1182 static void handle_remove_bp(GArray *params, void *user_ctx)
1183 {
1184     int res;
1185
1186     if (params->len != 3) {
1187         gdb_put_packet("E22");
1188         return;
1189     }
1190
1191     res = gdb_breakpoint_remove(gdbserver_state.c_cpu,
1192                                 get_param(params, 0)->val_ul,
1193                                 get_param(params, 1)->val_ull,
1194                                 get_param(params, 2)->val_ull);
1195     if (res >= 0) {
1196         gdb_put_packet("OK");
1197         return;
1198     } else if (res == -ENOSYS) {
1199         gdb_put_packet("");
1200         return;
1201     }
1202
1203     gdb_put_packet("E22");
1204 }
1205
1206 /*
1207  * handle_set/get_reg
1208  *
1209  * Older gdb are really dumb, and don't use 'G/g' if 'P/p' is available.
1210  * This works, but can be very slow. Anything new enough to understand
1211  * XML also knows how to use this properly. However to use this we
1212  * need to define a local XML file as well as be talking to a
1213  * reasonably modern gdb. Responding with an empty packet will cause
1214  * the remote gdb to fallback to older methods.
1215  */
1216
1217 static void handle_set_reg(GArray *params, void *user_ctx)
1218 {
1219     int reg_size;
1220
1221     if (params->len != 2) {
1222         gdb_put_packet("E22");
1223         return;
1224     }
1225
1226     reg_size = strlen(get_param(params, 1)->data) / 2;
1227     gdb_hextomem(gdbserver_state.mem_buf, get_param(params, 1)->data, reg_size);
1228     gdb_write_register(gdbserver_state.g_cpu, gdbserver_state.mem_buf->data,
1229                        get_param(params, 0)->val_ull);
1230     gdb_put_packet("OK");
1231 }
1232
1233 static void handle_get_reg(GArray *params, void *user_ctx)
1234 {
1235     int reg_size;
1236
1237     if (!params->len) {
1238         gdb_put_packet("E14");
1239         return;
1240     }
1241
1242     reg_size = gdb_read_register(gdbserver_state.g_cpu,
1243                                  gdbserver_state.mem_buf,
1244                                  get_param(params, 0)->val_ull);
1245     if (!reg_size) {
1246         gdb_put_packet("E14");
1247         return;
1248     } else {
1249         g_byte_array_set_size(gdbserver_state.mem_buf, reg_size);
1250     }
1251
1252     gdb_memtohex(gdbserver_state.str_buf,
1253                  gdbserver_state.mem_buf->data, reg_size);
1254     gdb_put_strbuf();
1255 }
1256
1257 static void handle_write_mem(GArray *params, void *user_ctx)
1258 {
1259     if (params->len != 3) {
1260         gdb_put_packet("E22");
1261         return;
1262     }
1263
1264     /* gdb_hextomem() reads 2*len bytes */
1265     if (get_param(params, 1)->val_ull >
1266         strlen(get_param(params, 2)->data) / 2) {
1267         gdb_put_packet("E22");
1268         return;
1269     }
1270
1271     gdb_hextomem(gdbserver_state.mem_buf, get_param(params, 2)->data,
1272                  get_param(params, 1)->val_ull);
1273     if (gdb_target_memory_rw_debug(gdbserver_state.g_cpu,
1274                                    get_param(params, 0)->val_ull,
1275                                    gdbserver_state.mem_buf->data,
1276                                    gdbserver_state.mem_buf->len, true)) {
1277         gdb_put_packet("E14");
1278         return;
1279     }
1280
1281     gdb_put_packet("OK");
1282 }
1283
1284 static void handle_read_mem(GArray *params, void *user_ctx)
1285 {
1286     if (params->len != 2) {
1287         gdb_put_packet("E22");
1288         return;
1289     }
1290
1291     /* gdb_memtohex() doubles the required space */
1292     if (get_param(params, 1)->val_ull > MAX_PACKET_LENGTH / 2) {
1293         gdb_put_packet("E22");
1294         return;
1295     }
1296
1297     g_byte_array_set_size(gdbserver_state.mem_buf,
1298                           get_param(params, 1)->val_ull);
1299
1300     if (gdb_target_memory_rw_debug(gdbserver_state.g_cpu,
1301                                    get_param(params, 0)->val_ull,
1302                                    gdbserver_state.mem_buf->data,
1303                                    gdbserver_state.mem_buf->len, false)) {
1304         gdb_put_packet("E14");
1305         return;
1306     }
1307
1308     gdb_memtohex(gdbserver_state.str_buf, gdbserver_state.mem_buf->data,
1309              gdbserver_state.mem_buf->len);
1310     gdb_put_strbuf();
1311 }
1312
1313 static void handle_write_all_regs(GArray *params, void *user_ctx)
1314 {
1315     int reg_id;
1316     size_t len;
1317     uint8_t *registers;
1318     int reg_size;
1319
1320     if (!params->len) {
1321         return;
1322     }
1323
1324     cpu_synchronize_state(gdbserver_state.g_cpu);
1325     len = strlen(get_param(params, 0)->data) / 2;
1326     gdb_hextomem(gdbserver_state.mem_buf, get_param(params, 0)->data, len);
1327     registers = gdbserver_state.mem_buf->data;
1328     for (reg_id = 0;
1329          reg_id < gdbserver_state.g_cpu->gdb_num_g_regs && len > 0;
1330          reg_id++) {
1331         reg_size = gdb_write_register(gdbserver_state.g_cpu, registers, reg_id);
1332         len -= reg_size;
1333         registers += reg_size;
1334     }
1335     gdb_put_packet("OK");
1336 }
1337
1338 static void handle_read_all_regs(GArray *params, void *user_ctx)
1339 {
1340     int reg_id;
1341     size_t len;
1342
1343     cpu_synchronize_state(gdbserver_state.g_cpu);
1344     g_byte_array_set_size(gdbserver_state.mem_buf, 0);
1345     len = 0;
1346     for (reg_id = 0; reg_id < gdbserver_state.g_cpu->gdb_num_g_regs; reg_id++) {
1347         len += gdb_read_register(gdbserver_state.g_cpu,
1348                                  gdbserver_state.mem_buf,
1349                                  reg_id);
1350     }
1351     g_assert(len == gdbserver_state.mem_buf->len);
1352
1353     gdb_memtohex(gdbserver_state.str_buf, gdbserver_state.mem_buf->data, len);
1354     gdb_put_strbuf();
1355 }
1356
1357
1358 static void handle_step(GArray *params, void *user_ctx)
1359 {
1360     if (params->len) {
1361         gdb_set_cpu_pc(get_param(params, 0)->val_ull);
1362     }
1363
1364     cpu_single_step(gdbserver_state.c_cpu, gdbserver_state.sstep_flags);
1365     gdb_continue();
1366 }
1367
1368 static void handle_backward(GArray *params, void *user_ctx)
1369 {
1370     if (!gdb_can_reverse()) {
1371         gdb_put_packet("E22");
1372     }
1373     if (params->len == 1) {
1374         switch (get_param(params, 0)->opcode) {
1375         case 's':
1376             if (replay_reverse_step()) {
1377                 gdb_continue();
1378             } else {
1379                 gdb_put_packet("E14");
1380             }
1381             return;
1382         case 'c':
1383             if (replay_reverse_continue()) {
1384                 gdb_continue();
1385             } else {
1386                 gdb_put_packet("E14");
1387             }
1388             return;
1389         }
1390     }
1391
1392     /* Default invalid command */
1393     gdb_put_packet("");
1394 }
1395
1396 static void handle_v_cont_query(GArray *params, void *user_ctx)
1397 {
1398     gdb_put_packet("vCont;c;C;s;S");
1399 }
1400
1401 static void handle_v_cont(GArray *params, void *user_ctx)
1402 {
1403     int res;
1404
1405     if (!params->len) {
1406         return;
1407     }
1408
1409     res = gdb_handle_vcont(get_param(params, 0)->data);
1410     if ((res == -EINVAL) || (res == -ERANGE)) {
1411         gdb_put_packet("E22");
1412     } else if (res) {
1413         gdb_put_packet("");
1414     }
1415 }
1416
1417 static void handle_v_attach(GArray *params, void *user_ctx)
1418 {
1419     GDBProcess *process;
1420     CPUState *cpu;
1421
1422     g_string_assign(gdbserver_state.str_buf, "E22");
1423     if (!params->len) {
1424         goto cleanup;
1425     }
1426
1427     process = gdb_get_process(get_param(params, 0)->val_ul);
1428     if (!process) {
1429         goto cleanup;
1430     }
1431
1432     cpu = gdb_get_first_cpu_in_process(process);
1433     if (!cpu) {
1434         goto cleanup;
1435     }
1436
1437     process->attached = true;
1438     gdbserver_state.g_cpu = cpu;
1439     gdbserver_state.c_cpu = cpu;
1440
1441     if (gdbserver_state.allow_stop_reply) {
1442         g_string_printf(gdbserver_state.str_buf, "T%02xthread:", GDB_SIGNAL_TRAP);
1443         gdb_append_thread_id(cpu, gdbserver_state.str_buf);
1444         g_string_append_c(gdbserver_state.str_buf, ';');
1445         gdbserver_state.allow_stop_reply = false;
1446 cleanup:
1447         gdb_put_strbuf();
1448     }
1449 }
1450
1451 static void handle_v_kill(GArray *params, void *user_ctx)
1452 {
1453     /* Kill the target */
1454     gdb_put_packet("OK");
1455     error_report("QEMU: Terminated via GDBstub");
1456     gdb_exit(0);
1457     gdb_qemu_exit(0);
1458 }
1459
1460 static const GdbCmdParseEntry gdb_v_commands_table[] = {
1461     /* Order is important if has same prefix */
1462     {
1463         .handler = handle_v_cont_query,
1464         .cmd = "Cont?",
1465         .cmd_startswith = 1
1466     },
1467     {
1468         .handler = handle_v_cont,
1469         .cmd = "Cont",
1470         .cmd_startswith = 1,
1471         .allow_stop_reply = true,
1472         .schema = "s0"
1473     },
1474     {
1475         .handler = handle_v_attach,
1476         .cmd = "Attach;",
1477         .cmd_startswith = 1,
1478         .allow_stop_reply = true,
1479         .schema = "l0"
1480     },
1481     {
1482         .handler = handle_v_kill,
1483         .cmd = "Kill;",
1484         .cmd_startswith = 1
1485     },
1486 #ifdef CONFIG_USER_ONLY
1487     /*
1488      * Host I/O Packets. See [1] for details.
1489      * [1] https://sourceware.org/gdb/onlinedocs/gdb/Host-I_002fO-Packets.html
1490      */
1491     {
1492         .handler = gdb_handle_v_file_open,
1493         .cmd = "File:open:",
1494         .cmd_startswith = 1,
1495         .schema = "s,L,L0"
1496     },
1497     {
1498         .handler = gdb_handle_v_file_close,
1499         .cmd = "File:close:",
1500         .cmd_startswith = 1,
1501         .schema = "l0"
1502     },
1503     {
1504         .handler = gdb_handle_v_file_pread,
1505         .cmd = "File:pread:",
1506         .cmd_startswith = 1,
1507         .schema = "l,L,L0"
1508     },
1509     {
1510         .handler = gdb_handle_v_file_readlink,
1511         .cmd = "File:readlink:",
1512         .cmd_startswith = 1,
1513         .schema = "s0"
1514     },
1515 #endif
1516 };
1517
1518 static void handle_v_commands(GArray *params, void *user_ctx)
1519 {
1520     if (!params->len) {
1521         return;
1522     }
1523
1524     if (process_string_cmd(get_param(params, 0)->data,
1525                            gdb_v_commands_table,
1526                            ARRAY_SIZE(gdb_v_commands_table))) {
1527         gdb_put_packet("");
1528     }
1529 }
1530
1531 static void handle_query_qemu_sstepbits(GArray *params, void *user_ctx)
1532 {
1533     g_string_printf(gdbserver_state.str_buf, "ENABLE=%x", SSTEP_ENABLE);
1534
1535     if (gdbserver_state.supported_sstep_flags & SSTEP_NOIRQ) {
1536         g_string_append_printf(gdbserver_state.str_buf, ",NOIRQ=%x",
1537                                SSTEP_NOIRQ);
1538     }
1539
1540     if (gdbserver_state.supported_sstep_flags & SSTEP_NOTIMER) {
1541         g_string_append_printf(gdbserver_state.str_buf, ",NOTIMER=%x",
1542                                SSTEP_NOTIMER);
1543     }
1544
1545     gdb_put_strbuf();
1546 }
1547
1548 static void handle_set_qemu_sstep(GArray *params, void *user_ctx)
1549 {
1550     int new_sstep_flags;
1551
1552     if (!params->len) {
1553         return;
1554     }
1555
1556     new_sstep_flags = get_param(params, 0)->val_ul;
1557
1558     if (new_sstep_flags  & ~gdbserver_state.supported_sstep_flags) {
1559         gdb_put_packet("E22");
1560         return;
1561     }
1562
1563     gdbserver_state.sstep_flags = new_sstep_flags;
1564     gdb_put_packet("OK");
1565 }
1566
1567 static void handle_query_qemu_sstep(GArray *params, void *user_ctx)
1568 {
1569     g_string_printf(gdbserver_state.str_buf, "0x%x",
1570                     gdbserver_state.sstep_flags);
1571     gdb_put_strbuf();
1572 }
1573
1574 static void handle_query_curr_tid(GArray *params, void *user_ctx)
1575 {
1576     CPUState *cpu;
1577     GDBProcess *process;
1578
1579     /*
1580      * "Current thread" remains vague in the spec, so always return
1581      * the first thread of the current process (gdb returns the
1582      * first thread).
1583      */
1584     process = gdb_get_cpu_process(gdbserver_state.g_cpu);
1585     cpu = gdb_get_first_cpu_in_process(process);
1586     g_string_assign(gdbserver_state.str_buf, "QC");
1587     gdb_append_thread_id(cpu, gdbserver_state.str_buf);
1588     gdb_put_strbuf();
1589 }
1590
1591 static void handle_query_threads(GArray *params, void *user_ctx)
1592 {
1593     if (!gdbserver_state.query_cpu) {
1594         gdb_put_packet("l");
1595         return;
1596     }
1597
1598     g_string_assign(gdbserver_state.str_buf, "m");
1599     gdb_append_thread_id(gdbserver_state.query_cpu, gdbserver_state.str_buf);
1600     gdb_put_strbuf();
1601     gdbserver_state.query_cpu = gdb_next_attached_cpu(gdbserver_state.query_cpu);
1602 }
1603
1604 static void handle_query_first_threads(GArray *params, void *user_ctx)
1605 {
1606     gdbserver_state.query_cpu = gdb_first_attached_cpu();
1607     handle_query_threads(params, user_ctx);
1608 }
1609
1610 static void handle_query_thread_extra(GArray *params, void *user_ctx)
1611 {
1612     g_autoptr(GString) rs = g_string_new(NULL);
1613     CPUState *cpu;
1614
1615     if (!params->len ||
1616         get_param(params, 0)->thread_id.kind == GDB_READ_THREAD_ERR) {
1617         gdb_put_packet("E22");
1618         return;
1619     }
1620
1621     cpu = gdb_get_cpu(get_param(params, 0)->thread_id.pid,
1622                       get_param(params, 0)->thread_id.tid);
1623     if (!cpu) {
1624         return;
1625     }
1626
1627     cpu_synchronize_state(cpu);
1628
1629     if (gdbserver_state.multiprocess && (gdbserver_state.process_num > 1)) {
1630         /* Print the CPU model and name in multiprocess mode */
1631         ObjectClass *oc = object_get_class(OBJECT(cpu));
1632         const char *cpu_model = object_class_get_name(oc);
1633         const char *cpu_name =
1634             object_get_canonical_path_component(OBJECT(cpu));
1635         g_string_printf(rs, "%s %s [%s]", cpu_model, cpu_name,
1636                         cpu->halted ? "halted " : "running");
1637     } else {
1638         g_string_printf(rs, "CPU#%d [%s]", cpu->cpu_index,
1639                         cpu->halted ? "halted " : "running");
1640     }
1641     trace_gdbstub_op_extra_info(rs->str);
1642     gdb_memtohex(gdbserver_state.str_buf, (uint8_t *)rs->str, rs->len);
1643     gdb_put_strbuf();
1644 }
1645
1646 static void handle_query_supported(GArray *params, void *user_ctx)
1647 {
1648     CPUClass *cc;
1649
1650     g_string_printf(gdbserver_state.str_buf, "PacketSize=%x", MAX_PACKET_LENGTH);
1651     cc = CPU_GET_CLASS(first_cpu);
1652     if (cc->gdb_core_xml_file) {
1653         g_string_append(gdbserver_state.str_buf, ";qXfer:features:read+");
1654     }
1655
1656     if (gdb_can_reverse()) {
1657         g_string_append(gdbserver_state.str_buf,
1658             ";ReverseStep+;ReverseContinue+");
1659     }
1660
1661 #if defined(CONFIG_USER_ONLY)
1662 #if defined(CONFIG_LINUX)
1663     if (gdbserver_state.c_cpu->opaque) {
1664         g_string_append(gdbserver_state.str_buf, ";qXfer:auxv:read+");
1665     }
1666     g_string_append(gdbserver_state.str_buf, ";QCatchSyscalls+");
1667 #endif
1668     g_string_append(gdbserver_state.str_buf, ";qXfer:exec-file:read+");
1669 #endif
1670
1671     if (params->len) {
1672         const char *gdb_supported = get_param(params, 0)->data;
1673
1674         if (strstr(gdb_supported, "multiprocess+")) {
1675             gdbserver_state.multiprocess = true;
1676         }
1677 #if defined(CONFIG_USER_ONLY)
1678         gdb_handle_query_supported_user(gdb_supported);
1679 #endif
1680     }
1681
1682     g_string_append(gdbserver_state.str_buf, ";vContSupported+;multiprocess+");
1683     gdb_put_strbuf();
1684 }
1685
1686 static void handle_query_xfer_features(GArray *params, void *user_ctx)
1687 {
1688     GDBProcess *process;
1689     CPUClass *cc;
1690     unsigned long len, total_len, addr;
1691     const char *xml;
1692     const char *p;
1693
1694     if (params->len < 3) {
1695         gdb_put_packet("E22");
1696         return;
1697     }
1698
1699     process = gdb_get_cpu_process(gdbserver_state.g_cpu);
1700     cc = CPU_GET_CLASS(gdbserver_state.g_cpu);
1701     if (!cc->gdb_core_xml_file) {
1702         gdb_put_packet("");
1703         return;
1704     }
1705
1706     p = get_param(params, 0)->data;
1707     xml = get_feature_xml(p, &p, process);
1708     if (!xml) {
1709         gdb_put_packet("E00");
1710         return;
1711     }
1712
1713     addr = get_param(params, 1)->val_ul;
1714     len = get_param(params, 2)->val_ul;
1715     total_len = strlen(xml);
1716     if (addr > total_len) {
1717         gdb_put_packet("E00");
1718         return;
1719     }
1720
1721     if (len > (MAX_PACKET_LENGTH - 5) / 2) {
1722         len = (MAX_PACKET_LENGTH - 5) / 2;
1723     }
1724
1725     if (len < total_len - addr) {
1726         g_string_assign(gdbserver_state.str_buf, "m");
1727         gdb_memtox(gdbserver_state.str_buf, xml + addr, len);
1728     } else {
1729         g_string_assign(gdbserver_state.str_buf, "l");
1730         gdb_memtox(gdbserver_state.str_buf, xml + addr, total_len - addr);
1731     }
1732
1733     gdb_put_packet_binary(gdbserver_state.str_buf->str,
1734                       gdbserver_state.str_buf->len, true);
1735 }
1736
1737 static void handle_query_qemu_supported(GArray *params, void *user_ctx)
1738 {
1739     g_string_printf(gdbserver_state.str_buf, "sstepbits;sstep");
1740 #ifndef CONFIG_USER_ONLY
1741     g_string_append(gdbserver_state.str_buf, ";PhyMemMode");
1742 #endif
1743     gdb_put_strbuf();
1744 }
1745
1746 static const GdbCmdParseEntry gdb_gen_query_set_common_table[] = {
1747     /* Order is important if has same prefix */
1748     {
1749         .handler = handle_query_qemu_sstepbits,
1750         .cmd = "qemu.sstepbits",
1751     },
1752     {
1753         .handler = handle_query_qemu_sstep,
1754         .cmd = "qemu.sstep",
1755     },
1756     {
1757         .handler = handle_set_qemu_sstep,
1758         .cmd = "qemu.sstep=",
1759         .cmd_startswith = 1,
1760         .schema = "l0"
1761     },
1762 };
1763
1764 static const GdbCmdParseEntry gdb_gen_query_table[] = {
1765     {
1766         .handler = handle_query_curr_tid,
1767         .cmd = "C",
1768     },
1769     {
1770         .handler = handle_query_threads,
1771         .cmd = "sThreadInfo",
1772     },
1773     {
1774         .handler = handle_query_first_threads,
1775         .cmd = "fThreadInfo",
1776     },
1777     {
1778         .handler = handle_query_thread_extra,
1779         .cmd = "ThreadExtraInfo,",
1780         .cmd_startswith = 1,
1781         .schema = "t0"
1782     },
1783 #ifdef CONFIG_USER_ONLY
1784     {
1785         .handler = gdb_handle_query_offsets,
1786         .cmd = "Offsets",
1787     },
1788 #else
1789     {
1790         .handler = gdb_handle_query_rcmd,
1791         .cmd = "Rcmd,",
1792         .cmd_startswith = 1,
1793         .schema = "s0"
1794     },
1795 #endif
1796     {
1797         .handler = handle_query_supported,
1798         .cmd = "Supported:",
1799         .cmd_startswith = 1,
1800         .schema = "s0"
1801     },
1802     {
1803         .handler = handle_query_supported,
1804         .cmd = "Supported",
1805         .schema = "s0"
1806     },
1807     {
1808         .handler = handle_query_xfer_features,
1809         .cmd = "Xfer:features:read:",
1810         .cmd_startswith = 1,
1811         .schema = "s:l,l0"
1812     },
1813 #if defined(CONFIG_USER_ONLY)
1814 #if defined(CONFIG_LINUX)
1815     {
1816         .handler = gdb_handle_query_xfer_auxv,
1817         .cmd = "Xfer:auxv:read::",
1818         .cmd_startswith = 1,
1819         .schema = "l,l0"
1820     },
1821 #endif
1822     {
1823         .handler = gdb_handle_query_xfer_exec_file,
1824         .cmd = "Xfer:exec-file:read:",
1825         .cmd_startswith = 1,
1826         .schema = "l:l,l0"
1827     },
1828 #endif
1829     {
1830         .handler = gdb_handle_query_attached,
1831         .cmd = "Attached:",
1832         .cmd_startswith = 1
1833     },
1834     {
1835         .handler = gdb_handle_query_attached,
1836         .cmd = "Attached",
1837     },
1838     {
1839         .handler = handle_query_qemu_supported,
1840         .cmd = "qemu.Supported",
1841     },
1842 #ifndef CONFIG_USER_ONLY
1843     {
1844         .handler = gdb_handle_query_qemu_phy_mem_mode,
1845         .cmd = "qemu.PhyMemMode",
1846     },
1847 #endif
1848 };
1849
1850 static const GdbCmdParseEntry gdb_gen_set_table[] = {
1851     /* Order is important if has same prefix */
1852     {
1853         .handler = handle_set_qemu_sstep,
1854         .cmd = "qemu.sstep:",
1855         .cmd_startswith = 1,
1856         .schema = "l0"
1857     },
1858 #ifndef CONFIG_USER_ONLY
1859     {
1860         .handler = gdb_handle_set_qemu_phy_mem_mode,
1861         .cmd = "qemu.PhyMemMode:",
1862         .cmd_startswith = 1,
1863         .schema = "l0"
1864     },
1865 #endif
1866 #if defined(CONFIG_USER_ONLY)
1867     {
1868         .handler = gdb_handle_set_catch_syscalls,
1869         .cmd = "CatchSyscalls:",
1870         .cmd_startswith = 1,
1871         .schema = "s0",
1872     },
1873 #endif
1874 };
1875
1876 static void handle_gen_query(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_query_table,
1890                            ARRAY_SIZE(gdb_gen_query_table))) {
1891         gdb_put_packet("");
1892     }
1893 }
1894
1895 static void handle_gen_set(GArray *params, void *user_ctx)
1896 {
1897     if (!params->len) {
1898         return;
1899     }
1900
1901     if (!process_string_cmd(get_param(params, 0)->data,
1902                             gdb_gen_query_set_common_table,
1903                             ARRAY_SIZE(gdb_gen_query_set_common_table))) {
1904         return;
1905     }
1906
1907     if (process_string_cmd(get_param(params, 0)->data,
1908                            gdb_gen_set_table,
1909                            ARRAY_SIZE(gdb_gen_set_table))) {
1910         gdb_put_packet("");
1911     }
1912 }
1913
1914 static void handle_target_halt(GArray *params, void *user_ctx)
1915 {
1916     if (gdbserver_state.allow_stop_reply) {
1917         g_string_printf(gdbserver_state.str_buf, "T%02xthread:", GDB_SIGNAL_TRAP);
1918         gdb_append_thread_id(gdbserver_state.c_cpu, gdbserver_state.str_buf);
1919         g_string_append_c(gdbserver_state.str_buf, ';');
1920         gdb_put_strbuf();
1921         gdbserver_state.allow_stop_reply = false;
1922     }
1923     /*
1924      * Remove all the breakpoints when this query is issued,
1925      * because gdb is doing an initial connect and the state
1926      * should be cleaned up.
1927      */
1928     gdb_breakpoint_remove_all(gdbserver_state.c_cpu);
1929 }
1930
1931 static int gdb_handle_packet(const char *line_buf)
1932 {
1933     const GdbCmdParseEntry *cmd_parser = NULL;
1934
1935     trace_gdbstub_io_command(line_buf);
1936
1937     switch (line_buf[0]) {
1938     case '!':
1939         gdb_put_packet("OK");
1940         break;
1941     case '?':
1942         {
1943             static const GdbCmdParseEntry target_halted_cmd_desc = {
1944                 .handler = handle_target_halt,
1945                 .cmd = "?",
1946                 .cmd_startswith = 1,
1947                 .allow_stop_reply = true,
1948             };
1949             cmd_parser = &target_halted_cmd_desc;
1950         }
1951         break;
1952     case 'c':
1953         {
1954             static const GdbCmdParseEntry continue_cmd_desc = {
1955                 .handler = handle_continue,
1956                 .cmd = "c",
1957                 .cmd_startswith = 1,
1958                 .allow_stop_reply = true,
1959                 .schema = "L0"
1960             };
1961             cmd_parser = &continue_cmd_desc;
1962         }
1963         break;
1964     case 'C':
1965         {
1966             static const GdbCmdParseEntry cont_with_sig_cmd_desc = {
1967                 .handler = handle_cont_with_sig,
1968                 .cmd = "C",
1969                 .cmd_startswith = 1,
1970                 .allow_stop_reply = true,
1971                 .schema = "l0"
1972             };
1973             cmd_parser = &cont_with_sig_cmd_desc;
1974         }
1975         break;
1976     case 'v':
1977         {
1978             static const GdbCmdParseEntry v_cmd_desc = {
1979                 .handler = handle_v_commands,
1980                 .cmd = "v",
1981                 .cmd_startswith = 1,
1982                 .schema = "s0"
1983             };
1984             cmd_parser = &v_cmd_desc;
1985         }
1986         break;
1987     case 'k':
1988         /* Kill the target */
1989         error_report("QEMU: Terminated via GDBstub");
1990         gdb_exit(0);
1991         gdb_qemu_exit(0);
1992         break;
1993     case 'D':
1994         {
1995             static const GdbCmdParseEntry detach_cmd_desc = {
1996                 .handler = handle_detach,
1997                 .cmd = "D",
1998                 .cmd_startswith = 1,
1999                 .schema = "?.l0"
2000             };
2001             cmd_parser = &detach_cmd_desc;
2002         }
2003         break;
2004     case 's':
2005         {
2006             static const GdbCmdParseEntry step_cmd_desc = {
2007                 .handler = handle_step,
2008                 .cmd = "s",
2009                 .cmd_startswith = 1,
2010                 .allow_stop_reply = true,
2011                 .schema = "L0"
2012             };
2013             cmd_parser = &step_cmd_desc;
2014         }
2015         break;
2016     case 'b':
2017         {
2018             static const GdbCmdParseEntry backward_cmd_desc = {
2019                 .handler = handle_backward,
2020                 .cmd = "b",
2021                 .cmd_startswith = 1,
2022                 .allow_stop_reply = true,
2023                 .schema = "o0"
2024             };
2025             cmd_parser = &backward_cmd_desc;
2026         }
2027         break;
2028     case 'F':
2029         {
2030             static const GdbCmdParseEntry file_io_cmd_desc = {
2031                 .handler = gdb_handle_file_io,
2032                 .cmd = "F",
2033                 .cmd_startswith = 1,
2034                 .schema = "L,L,o0"
2035             };
2036             cmd_parser = &file_io_cmd_desc;
2037         }
2038         break;
2039     case 'g':
2040         {
2041             static const GdbCmdParseEntry read_all_regs_cmd_desc = {
2042                 .handler = handle_read_all_regs,
2043                 .cmd = "g",
2044                 .cmd_startswith = 1
2045             };
2046             cmd_parser = &read_all_regs_cmd_desc;
2047         }
2048         break;
2049     case 'G':
2050         {
2051             static const GdbCmdParseEntry write_all_regs_cmd_desc = {
2052                 .handler = handle_write_all_regs,
2053                 .cmd = "G",
2054                 .cmd_startswith = 1,
2055                 .schema = "s0"
2056             };
2057             cmd_parser = &write_all_regs_cmd_desc;
2058         }
2059         break;
2060     case 'm':
2061         {
2062             static const GdbCmdParseEntry read_mem_cmd_desc = {
2063                 .handler = handle_read_mem,
2064                 .cmd = "m",
2065                 .cmd_startswith = 1,
2066                 .schema = "L,L0"
2067             };
2068             cmd_parser = &read_mem_cmd_desc;
2069         }
2070         break;
2071     case 'M':
2072         {
2073             static const GdbCmdParseEntry write_mem_cmd_desc = {
2074                 .handler = handle_write_mem,
2075                 .cmd = "M",
2076                 .cmd_startswith = 1,
2077                 .schema = "L,L:s0"
2078             };
2079             cmd_parser = &write_mem_cmd_desc;
2080         }
2081         break;
2082     case 'p':
2083         {
2084             static const GdbCmdParseEntry get_reg_cmd_desc = {
2085                 .handler = handle_get_reg,
2086                 .cmd = "p",
2087                 .cmd_startswith = 1,
2088                 .schema = "L0"
2089             };
2090             cmd_parser = &get_reg_cmd_desc;
2091         }
2092         break;
2093     case 'P':
2094         {
2095             static const GdbCmdParseEntry set_reg_cmd_desc = {
2096                 .handler = handle_set_reg,
2097                 .cmd = "P",
2098                 .cmd_startswith = 1,
2099                 .schema = "L?s0"
2100             };
2101             cmd_parser = &set_reg_cmd_desc;
2102         }
2103         break;
2104     case 'Z':
2105         {
2106             static const GdbCmdParseEntry insert_bp_cmd_desc = {
2107                 .handler = handle_insert_bp,
2108                 .cmd = "Z",
2109                 .cmd_startswith = 1,
2110                 .schema = "l?L?L0"
2111             };
2112             cmd_parser = &insert_bp_cmd_desc;
2113         }
2114         break;
2115     case 'z':
2116         {
2117             static const GdbCmdParseEntry remove_bp_cmd_desc = {
2118                 .handler = handle_remove_bp,
2119                 .cmd = "z",
2120                 .cmd_startswith = 1,
2121                 .schema = "l?L?L0"
2122             };
2123             cmd_parser = &remove_bp_cmd_desc;
2124         }
2125         break;
2126     case 'H':
2127         {
2128             static const GdbCmdParseEntry set_thread_cmd_desc = {
2129                 .handler = handle_set_thread,
2130                 .cmd = "H",
2131                 .cmd_startswith = 1,
2132                 .schema = "o.t0"
2133             };
2134             cmd_parser = &set_thread_cmd_desc;
2135         }
2136         break;
2137     case 'T':
2138         {
2139             static const GdbCmdParseEntry thread_alive_cmd_desc = {
2140                 .handler = handle_thread_alive,
2141                 .cmd = "T",
2142                 .cmd_startswith = 1,
2143                 .schema = "t0"
2144             };
2145             cmd_parser = &thread_alive_cmd_desc;
2146         }
2147         break;
2148     case 'q':
2149         {
2150             static const GdbCmdParseEntry gen_query_cmd_desc = {
2151                 .handler = handle_gen_query,
2152                 .cmd = "q",
2153                 .cmd_startswith = 1,
2154                 .schema = "s0"
2155             };
2156             cmd_parser = &gen_query_cmd_desc;
2157         }
2158         break;
2159     case 'Q':
2160         {
2161             static const GdbCmdParseEntry gen_set_cmd_desc = {
2162                 .handler = handle_gen_set,
2163                 .cmd = "Q",
2164                 .cmd_startswith = 1,
2165                 .schema = "s0"
2166             };
2167             cmd_parser = &gen_set_cmd_desc;
2168         }
2169         break;
2170     default:
2171         /* put empty packet */
2172         gdb_put_packet("");
2173         break;
2174     }
2175
2176     if (cmd_parser) {
2177         run_cmd_parser(line_buf, cmd_parser);
2178     }
2179
2180     return RS_IDLE;
2181 }
2182
2183 void gdb_set_stop_cpu(CPUState *cpu)
2184 {
2185     GDBProcess *p = gdb_get_cpu_process(cpu);
2186
2187     if (!p->attached) {
2188         /*
2189          * Having a stop CPU corresponding to a process that is not attached
2190          * confuses GDB. So we ignore the request.
2191          */
2192         return;
2193     }
2194
2195     gdbserver_state.c_cpu = cpu;
2196     gdbserver_state.g_cpu = cpu;
2197 }
2198
2199 void gdb_read_byte(uint8_t ch)
2200 {
2201     uint8_t reply;
2202
2203     gdbserver_state.allow_stop_reply = false;
2204 #ifndef CONFIG_USER_ONLY
2205     if (gdbserver_state.last_packet->len) {
2206         /* Waiting for a response to the last packet.  If we see the start
2207            of a new command then abandon the previous response.  */
2208         if (ch == '-') {
2209             trace_gdbstub_err_got_nack();
2210             gdb_put_buffer(gdbserver_state.last_packet->data,
2211                        gdbserver_state.last_packet->len);
2212         } else if (ch == '+') {
2213             trace_gdbstub_io_got_ack();
2214         } else {
2215             trace_gdbstub_io_got_unexpected(ch);
2216         }
2217
2218         if (ch == '+' || ch == '$') {
2219             g_byte_array_set_size(gdbserver_state.last_packet, 0);
2220         }
2221         if (ch != '$')
2222             return;
2223     }
2224     if (runstate_is_running()) {
2225         /*
2226          * When the CPU is running, we cannot do anything except stop
2227          * it when receiving a char. This is expected on a Ctrl-C in the
2228          * gdb client. Because we are in all-stop mode, gdb sends a
2229          * 0x03 byte which is not a usual packet, so we handle it specially
2230          * here, but it does expect a stop reply.
2231          */
2232         if (ch != 0x03) {
2233             trace_gdbstub_err_unexpected_runpkt(ch);
2234         } else {
2235             gdbserver_state.allow_stop_reply = true;
2236         }
2237         vm_stop(RUN_STATE_PAUSED);
2238     } else
2239 #endif
2240     {
2241         switch(gdbserver_state.state) {
2242         case RS_IDLE:
2243             if (ch == '$') {
2244                 /* start of command packet */
2245                 gdbserver_state.line_buf_index = 0;
2246                 gdbserver_state.line_sum = 0;
2247                 gdbserver_state.state = RS_GETLINE;
2248             } else if (ch == '+') {
2249                 /*
2250                  * do nothing, gdb may preemptively send out ACKs on
2251                  * initial connection
2252                  */
2253             } else {
2254                 trace_gdbstub_err_garbage(ch);
2255             }
2256             break;
2257         case RS_GETLINE:
2258             if (ch == '}') {
2259                 /* start escape sequence */
2260                 gdbserver_state.state = RS_GETLINE_ESC;
2261                 gdbserver_state.line_sum += ch;
2262             } else if (ch == '*') {
2263                 /* start run length encoding sequence */
2264                 gdbserver_state.state = RS_GETLINE_RLE;
2265                 gdbserver_state.line_sum += ch;
2266             } else if (ch == '#') {
2267                 /* end of command, start of checksum*/
2268                 gdbserver_state.state = RS_CHKSUM1;
2269             } else if (gdbserver_state.line_buf_index >= sizeof(gdbserver_state.line_buf) - 1) {
2270                 trace_gdbstub_err_overrun();
2271                 gdbserver_state.state = RS_IDLE;
2272             } else {
2273                 /* unescaped command character */
2274                 gdbserver_state.line_buf[gdbserver_state.line_buf_index++] = ch;
2275                 gdbserver_state.line_sum += ch;
2276             }
2277             break;
2278         case RS_GETLINE_ESC:
2279             if (ch == '#') {
2280                 /* unexpected end of command in escape sequence */
2281                 gdbserver_state.state = RS_CHKSUM1;
2282             } else if (gdbserver_state.line_buf_index >= sizeof(gdbserver_state.line_buf) - 1) {
2283                 /* command buffer overrun */
2284                 trace_gdbstub_err_overrun();
2285                 gdbserver_state.state = RS_IDLE;
2286             } else {
2287                 /* parse escaped character and leave escape state */
2288                 gdbserver_state.line_buf[gdbserver_state.line_buf_index++] = ch ^ 0x20;
2289                 gdbserver_state.line_sum += ch;
2290                 gdbserver_state.state = RS_GETLINE;
2291             }
2292             break;
2293         case RS_GETLINE_RLE:
2294             /*
2295              * Run-length encoding is explained in "Debugging with GDB /
2296              * Appendix E GDB Remote Serial Protocol / Overview".
2297              */
2298             if (ch < ' ' || ch == '#' || ch == '$' || ch > 126) {
2299                 /* invalid RLE count encoding */
2300                 trace_gdbstub_err_invalid_repeat(ch);
2301                 gdbserver_state.state = RS_GETLINE;
2302             } else {
2303                 /* decode repeat length */
2304                 int repeat = ch - ' ' + 3;
2305                 if (gdbserver_state.line_buf_index + repeat >= sizeof(gdbserver_state.line_buf) - 1) {
2306                     /* that many repeats would overrun the command buffer */
2307                     trace_gdbstub_err_overrun();
2308                     gdbserver_state.state = RS_IDLE;
2309                 } else if (gdbserver_state.line_buf_index < 1) {
2310                     /* got a repeat but we have nothing to repeat */
2311                     trace_gdbstub_err_invalid_rle();
2312                     gdbserver_state.state = RS_GETLINE;
2313                 } else {
2314                     /* repeat the last character */
2315                     memset(gdbserver_state.line_buf + gdbserver_state.line_buf_index,
2316                            gdbserver_state.line_buf[gdbserver_state.line_buf_index - 1], repeat);
2317                     gdbserver_state.line_buf_index += repeat;
2318                     gdbserver_state.line_sum += ch;
2319                     gdbserver_state.state = RS_GETLINE;
2320                 }
2321             }
2322             break;
2323         case RS_CHKSUM1:
2324             /* get high hex digit of checksum */
2325             if (!isxdigit(ch)) {
2326                 trace_gdbstub_err_checksum_invalid(ch);
2327                 gdbserver_state.state = RS_GETLINE;
2328                 break;
2329             }
2330             gdbserver_state.line_buf[gdbserver_state.line_buf_index] = '\0';
2331             gdbserver_state.line_csum = fromhex(ch) << 4;
2332             gdbserver_state.state = RS_CHKSUM2;
2333             break;
2334         case RS_CHKSUM2:
2335             /* get low hex digit of checksum */
2336             if (!isxdigit(ch)) {
2337                 trace_gdbstub_err_checksum_invalid(ch);
2338                 gdbserver_state.state = RS_GETLINE;
2339                 break;
2340             }
2341             gdbserver_state.line_csum |= fromhex(ch);
2342
2343             if (gdbserver_state.line_csum != (gdbserver_state.line_sum & 0xff)) {
2344                 trace_gdbstub_err_checksum_incorrect(gdbserver_state.line_sum, gdbserver_state.line_csum);
2345                 /* send NAK reply */
2346                 reply = '-';
2347                 gdb_put_buffer(&reply, 1);
2348                 gdbserver_state.state = RS_IDLE;
2349             } else {
2350                 /* send ACK reply */
2351                 reply = '+';
2352                 gdb_put_buffer(&reply, 1);
2353                 gdbserver_state.state = gdb_handle_packet(gdbserver_state.line_buf);
2354             }
2355             break;
2356         default:
2357             abort();
2358         }
2359     }
2360 }
2361
2362 /*
2363  * Create the process that will contain all the "orphan" CPUs (that are not
2364  * part of a CPU cluster). Note that if this process contains no CPUs, it won't
2365  * be attachable and thus will be invisible to the user.
2366  */
2367 void gdb_create_default_process(GDBState *s)
2368 {
2369     GDBProcess *process;
2370     int pid;
2371
2372 #ifdef CONFIG_USER_ONLY
2373     assert(gdbserver_state.process_num == 0);
2374     pid = getpid();
2375 #else
2376     if (gdbserver_state.process_num) {
2377         pid = s->processes[s->process_num - 1].pid;
2378     } else {
2379         pid = 0;
2380     }
2381     /* We need an available PID slot for this process */
2382     assert(pid < UINT32_MAX);
2383     pid++;
2384 #endif
2385
2386     s->processes = g_renew(GDBProcess, s->processes, ++s->process_num);
2387     process = &s->processes[s->process_num - 1];
2388     process->pid = pid;
2389     process->attached = false;
2390     process->target_xml = NULL;
2391 }
2392