xref: /openbmc/qemu/gdbstub/gdbstub.c (revision 93e0932b)
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 "qapi/error.h"
28 #include "qemu/error-report.h"
29 #include "qemu/ctype.h"
30 #include "qemu/cutils.h"
31 #include "qemu/module.h"
32 #include "trace.h"
33 #include "exec/gdbstub.h"
34 #ifdef CONFIG_USER_ONLY
35 #include "qemu.h"
36 #else
37 #include "monitor/monitor.h"
38 #include "chardev/char.h"
39 #include "chardev/char-fe.h"
40 #include "hw/cpu/cluster.h"
41 #include "hw/boards.h"
42 #endif
43 
44 #define MAX_PACKET_LENGTH 4096
45 
46 #include "qemu/sockets.h"
47 #include "sysemu/hw_accel.h"
48 #include "sysemu/runstate.h"
49 #include "semihosting/semihost.h"
50 #include "exec/exec-all.h"
51 #include "exec/hwaddr.h"
52 #include "sysemu/replay.h"
53 
54 #include "internals.h"
55 
56 #ifdef CONFIG_USER_ONLY
57 #define GDB_ATTACHED "0"
58 #else
59 #define GDB_ATTACHED "1"
60 #endif
61 
62 #ifndef CONFIG_USER_ONLY
63 static int phy_memory_mode;
64 #endif
65 
66 static inline int target_memory_rw_debug(CPUState *cpu, target_ulong addr,
67                                          uint8_t *buf, int len, bool is_write)
68 {
69     CPUClass *cc;
70 
71 #ifndef CONFIG_USER_ONLY
72     if (phy_memory_mode) {
73         if (is_write) {
74             cpu_physical_memory_write(addr, buf, len);
75         } else {
76             cpu_physical_memory_read(addr, buf, len);
77         }
78         return 0;
79     }
80 #endif
81 
82     cc = CPU_GET_CLASS(cpu);
83     if (cc->memory_rw_debug) {
84         return cc->memory_rw_debug(cpu, addr, buf, len, is_write);
85     }
86     return cpu_memory_rw_debug(cpu, addr, buf, len, is_write);
87 }
88 
89 /* Return the GDB index for a given vCPU state.
90  *
91  * For user mode this is simply the thread id. In system mode GDB
92  * numbers CPUs from 1 as 0 is reserved as an "any cpu" index.
93  */
94 static inline int cpu_gdb_index(CPUState *cpu)
95 {
96 #if defined(CONFIG_USER_ONLY)
97     TaskState *ts = (TaskState *) cpu->opaque;
98     return ts ? ts->ts_tid : -1;
99 #else
100     return cpu->cpu_index + 1;
101 #endif
102 }
103 
104 enum {
105     GDB_SIGNAL_0 = 0,
106     GDB_SIGNAL_INT = 2,
107     GDB_SIGNAL_QUIT = 3,
108     GDB_SIGNAL_TRAP = 5,
109     GDB_SIGNAL_ABRT = 6,
110     GDB_SIGNAL_ALRM = 14,
111     GDB_SIGNAL_IO = 23,
112     GDB_SIGNAL_XCPU = 24,
113     GDB_SIGNAL_UNKNOWN = 143
114 };
115 
116 #ifdef CONFIG_USER_ONLY
117 
118 /* Map target signal numbers to GDB protocol signal numbers and vice
119  * versa.  For user emulation's currently supported systems, we can
120  * assume most signals are defined.
121  */
122 
123 static int gdb_signal_table[] = {
124     0,
125     TARGET_SIGHUP,
126     TARGET_SIGINT,
127     TARGET_SIGQUIT,
128     TARGET_SIGILL,
129     TARGET_SIGTRAP,
130     TARGET_SIGABRT,
131     -1, /* SIGEMT */
132     TARGET_SIGFPE,
133     TARGET_SIGKILL,
134     TARGET_SIGBUS,
135     TARGET_SIGSEGV,
136     TARGET_SIGSYS,
137     TARGET_SIGPIPE,
138     TARGET_SIGALRM,
139     TARGET_SIGTERM,
140     TARGET_SIGURG,
141     TARGET_SIGSTOP,
142     TARGET_SIGTSTP,
143     TARGET_SIGCONT,
144     TARGET_SIGCHLD,
145     TARGET_SIGTTIN,
146     TARGET_SIGTTOU,
147     TARGET_SIGIO,
148     TARGET_SIGXCPU,
149     TARGET_SIGXFSZ,
150     TARGET_SIGVTALRM,
151     TARGET_SIGPROF,
152     TARGET_SIGWINCH,
153     -1, /* SIGLOST */
154     TARGET_SIGUSR1,
155     TARGET_SIGUSR2,
156 #ifdef TARGET_SIGPWR
157     TARGET_SIGPWR,
158 #else
159     -1,
160 #endif
161     -1, /* SIGPOLL */
162     -1,
163     -1,
164     -1,
165     -1,
166     -1,
167     -1,
168     -1,
169     -1,
170     -1,
171     -1,
172     -1,
173 #ifdef __SIGRTMIN
174     __SIGRTMIN + 1,
175     __SIGRTMIN + 2,
176     __SIGRTMIN + 3,
177     __SIGRTMIN + 4,
178     __SIGRTMIN + 5,
179     __SIGRTMIN + 6,
180     __SIGRTMIN + 7,
181     __SIGRTMIN + 8,
182     __SIGRTMIN + 9,
183     __SIGRTMIN + 10,
184     __SIGRTMIN + 11,
185     __SIGRTMIN + 12,
186     __SIGRTMIN + 13,
187     __SIGRTMIN + 14,
188     __SIGRTMIN + 15,
189     __SIGRTMIN + 16,
190     __SIGRTMIN + 17,
191     __SIGRTMIN + 18,
192     __SIGRTMIN + 19,
193     __SIGRTMIN + 20,
194     __SIGRTMIN + 21,
195     __SIGRTMIN + 22,
196     __SIGRTMIN + 23,
197     __SIGRTMIN + 24,
198     __SIGRTMIN + 25,
199     __SIGRTMIN + 26,
200     __SIGRTMIN + 27,
201     __SIGRTMIN + 28,
202     __SIGRTMIN + 29,
203     __SIGRTMIN + 30,
204     __SIGRTMIN + 31,
205     -1, /* SIGCANCEL */
206     __SIGRTMIN,
207     __SIGRTMIN + 32,
208     __SIGRTMIN + 33,
209     __SIGRTMIN + 34,
210     __SIGRTMIN + 35,
211     __SIGRTMIN + 36,
212     __SIGRTMIN + 37,
213     __SIGRTMIN + 38,
214     __SIGRTMIN + 39,
215     __SIGRTMIN + 40,
216     __SIGRTMIN + 41,
217     __SIGRTMIN + 42,
218     __SIGRTMIN + 43,
219     __SIGRTMIN + 44,
220     __SIGRTMIN + 45,
221     __SIGRTMIN + 46,
222     __SIGRTMIN + 47,
223     __SIGRTMIN + 48,
224     __SIGRTMIN + 49,
225     __SIGRTMIN + 50,
226     __SIGRTMIN + 51,
227     __SIGRTMIN + 52,
228     __SIGRTMIN + 53,
229     __SIGRTMIN + 54,
230     __SIGRTMIN + 55,
231     __SIGRTMIN + 56,
232     __SIGRTMIN + 57,
233     __SIGRTMIN + 58,
234     __SIGRTMIN + 59,
235     __SIGRTMIN + 60,
236     __SIGRTMIN + 61,
237     __SIGRTMIN + 62,
238     __SIGRTMIN + 63,
239     __SIGRTMIN + 64,
240     __SIGRTMIN + 65,
241     __SIGRTMIN + 66,
242     __SIGRTMIN + 67,
243     __SIGRTMIN + 68,
244     __SIGRTMIN + 69,
245     __SIGRTMIN + 70,
246     __SIGRTMIN + 71,
247     __SIGRTMIN + 72,
248     __SIGRTMIN + 73,
249     __SIGRTMIN + 74,
250     __SIGRTMIN + 75,
251     __SIGRTMIN + 76,
252     __SIGRTMIN + 77,
253     __SIGRTMIN + 78,
254     __SIGRTMIN + 79,
255     __SIGRTMIN + 80,
256     __SIGRTMIN + 81,
257     __SIGRTMIN + 82,
258     __SIGRTMIN + 83,
259     __SIGRTMIN + 84,
260     __SIGRTMIN + 85,
261     __SIGRTMIN + 86,
262     __SIGRTMIN + 87,
263     __SIGRTMIN + 88,
264     __SIGRTMIN + 89,
265     __SIGRTMIN + 90,
266     __SIGRTMIN + 91,
267     __SIGRTMIN + 92,
268     __SIGRTMIN + 93,
269     __SIGRTMIN + 94,
270     __SIGRTMIN + 95,
271     -1, /* SIGINFO */
272     -1, /* UNKNOWN */
273     -1, /* DEFAULT */
274     -1,
275     -1,
276     -1,
277     -1,
278     -1,
279     -1
280 #endif
281 };
282 #else
283 /* In system mode we only need SIGINT and SIGTRAP; other signals
284    are not yet supported.  */
285 
286 enum {
287     TARGET_SIGINT = 2,
288     TARGET_SIGTRAP = 5
289 };
290 
291 static int gdb_signal_table[] = {
292     -1,
293     -1,
294     TARGET_SIGINT,
295     -1,
296     -1,
297     TARGET_SIGTRAP
298 };
299 #endif
300 
301 #ifdef CONFIG_USER_ONLY
302 static int target_signal_to_gdb (int sig)
303 {
304     int i;
305     for (i = 0; i < ARRAY_SIZE (gdb_signal_table); i++)
306         if (gdb_signal_table[i] == sig)
307             return i;
308     return GDB_SIGNAL_UNKNOWN;
309 }
310 #endif
311 
312 static int gdb_signal_to_target (int sig)
313 {
314     if (sig < ARRAY_SIZE (gdb_signal_table))
315         return gdb_signal_table[sig];
316     else
317         return -1;
318 }
319 
320 typedef struct GDBRegisterState {
321     int base_reg;
322     int num_regs;
323     gdb_get_reg_cb get_reg;
324     gdb_set_reg_cb set_reg;
325     const char *xml;
326     struct GDBRegisterState *next;
327 } GDBRegisterState;
328 
329 typedef struct GDBProcess {
330     uint32_t pid;
331     bool attached;
332 
333     char target_xml[1024];
334 } GDBProcess;
335 
336 enum RSState {
337     RS_INACTIVE,
338     RS_IDLE,
339     RS_GETLINE,
340     RS_GETLINE_ESC,
341     RS_GETLINE_RLE,
342     RS_CHKSUM1,
343     RS_CHKSUM2,
344 };
345 typedef struct GDBState {
346     bool init;       /* have we been initialised? */
347     CPUState *c_cpu; /* current CPU for step/continue ops */
348     CPUState *g_cpu; /* current CPU for other ops */
349     CPUState *query_cpu; /* for q{f|s}ThreadInfo */
350     enum RSState state; /* parsing state */
351     char line_buf[MAX_PACKET_LENGTH];
352     int line_buf_index;
353     int line_sum; /* running checksum */
354     int line_csum; /* checksum at the end of the packet */
355     GByteArray *last_packet;
356     int signal;
357 #ifdef CONFIG_USER_ONLY
358     int fd;
359     char *socket_path;
360     int running_state;
361 #else
362     CharBackend chr;
363     Chardev *mon_chr;
364 #endif
365     bool multiprocess;
366     GDBProcess *processes;
367     int process_num;
368     char syscall_buf[256];
369     gdb_syscall_complete_cb current_syscall_cb;
370     GString *str_buf;
371     GByteArray *mem_buf;
372     int sstep_flags;
373     int supported_sstep_flags;
374 } GDBState;
375 
376 static GDBState gdbserver_state;
377 
378 static void init_gdbserver_state(void)
379 {
380     g_assert(!gdbserver_state.init);
381     memset(&gdbserver_state, 0, sizeof(GDBState));
382     gdbserver_state.init = true;
383     gdbserver_state.str_buf = g_string_new(NULL);
384     gdbserver_state.mem_buf = g_byte_array_sized_new(MAX_PACKET_LENGTH);
385     gdbserver_state.last_packet = g_byte_array_sized_new(MAX_PACKET_LENGTH + 4);
386 
387     /*
388      * What single-step modes are supported is accelerator dependent.
389      * By default try to use no IRQs and no timers while single
390      * stepping so as to make single stepping like a typical ICE HW step.
391      */
392     gdbserver_state.supported_sstep_flags = accel_supported_gdbstub_sstep_flags();
393     gdbserver_state.sstep_flags = SSTEP_ENABLE | SSTEP_NOIRQ | SSTEP_NOTIMER;
394     gdbserver_state.sstep_flags &= gdbserver_state.supported_sstep_flags;
395 }
396 
397 #ifndef CONFIG_USER_ONLY
398 static void reset_gdbserver_state(void)
399 {
400     g_free(gdbserver_state.processes);
401     gdbserver_state.processes = NULL;
402     gdbserver_state.process_num = 0;
403 }
404 #endif
405 
406 bool gdb_has_xml;
407 
408 #ifdef CONFIG_USER_ONLY
409 
410 static int get_char(void)
411 {
412     uint8_t ch;
413     int ret;
414 
415     for(;;) {
416         ret = recv(gdbserver_state.fd, &ch, 1, 0);
417         if (ret < 0) {
418             if (errno == ECONNRESET)
419                 gdbserver_state.fd = -1;
420             if (errno != EINTR)
421                 return -1;
422         } else if (ret == 0) {
423             close(gdbserver_state.fd);
424             gdbserver_state.fd = -1;
425             return -1;
426         } else {
427             break;
428         }
429     }
430     return ch;
431 }
432 #endif
433 
434 /*
435  * Return true if there is a GDB currently connected to the stub
436  * and attached to a CPU
437  */
438 static bool gdb_attached(void)
439 {
440     return gdbserver_state.init && gdbserver_state.c_cpu;
441 }
442 
443 static enum {
444     GDB_SYS_UNKNOWN,
445     GDB_SYS_ENABLED,
446     GDB_SYS_DISABLED,
447 } gdb_syscall_mode;
448 
449 /* Decide if either remote gdb syscalls or native file IO should be used. */
450 int use_gdb_syscalls(void)
451 {
452     SemihostingTarget target = semihosting_get_target();
453     if (target == SEMIHOSTING_TARGET_NATIVE) {
454         /* -semihosting-config target=native */
455         return false;
456     } else if (target == SEMIHOSTING_TARGET_GDB) {
457         /* -semihosting-config target=gdb */
458         return true;
459     }
460 
461     /* -semihosting-config target=auto */
462     /* On the first call check if gdb is connected and remember. */
463     if (gdb_syscall_mode == GDB_SYS_UNKNOWN) {
464         gdb_syscall_mode = gdb_attached() ? GDB_SYS_ENABLED : GDB_SYS_DISABLED;
465     }
466     return gdb_syscall_mode == GDB_SYS_ENABLED;
467 }
468 
469 static bool stub_can_reverse(void)
470 {
471 #ifdef CONFIG_USER_ONLY
472     return false;
473 #else
474     return replay_mode == REPLAY_MODE_PLAY;
475 #endif
476 }
477 
478 /* Resume execution.  */
479 static inline void gdb_continue(void)
480 {
481 
482 #ifdef CONFIG_USER_ONLY
483     gdbserver_state.running_state = 1;
484     trace_gdbstub_op_continue();
485 #else
486     if (!runstate_needs_reset()) {
487         trace_gdbstub_op_continue();
488         vm_start();
489     }
490 #endif
491 }
492 
493 /*
494  * Resume execution, per CPU actions. For user-mode emulation it's
495  * equivalent to gdb_continue.
496  */
497 static int gdb_continue_partial(char *newstates)
498 {
499     CPUState *cpu;
500     int res = 0;
501 #ifdef CONFIG_USER_ONLY
502     /*
503      * This is not exactly accurate, but it's an improvement compared to the
504      * previous situation, where only one CPU would be single-stepped.
505      */
506     CPU_FOREACH(cpu) {
507         if (newstates[cpu->cpu_index] == 's') {
508             trace_gdbstub_op_stepping(cpu->cpu_index);
509             cpu_single_step(cpu, gdbserver_state.sstep_flags);
510         }
511     }
512     gdbserver_state.running_state = 1;
513 #else
514     int flag = 0;
515 
516     if (!runstate_needs_reset()) {
517         bool step_requested = false;
518         CPU_FOREACH(cpu) {
519             if (newstates[cpu->cpu_index] == 's') {
520                 step_requested = true;
521                 break;
522             }
523         }
524 
525         if (vm_prepare_start(step_requested)) {
526             return 0;
527         }
528 
529         CPU_FOREACH(cpu) {
530             switch (newstates[cpu->cpu_index]) {
531             case 0:
532             case 1:
533                 break; /* nothing to do here */
534             case 's':
535                 trace_gdbstub_op_stepping(cpu->cpu_index);
536                 cpu_single_step(cpu, gdbserver_state.sstep_flags);
537                 cpu_resume(cpu);
538                 flag = 1;
539                 break;
540             case 'c':
541                 trace_gdbstub_op_continue_cpu(cpu->cpu_index);
542                 cpu_resume(cpu);
543                 flag = 1;
544                 break;
545             default:
546                 res = -1;
547                 break;
548             }
549         }
550     }
551     if (flag) {
552         qemu_clock_enable(QEMU_CLOCK_VIRTUAL, true);
553     }
554 #endif
555     return res;
556 }
557 
558 static void put_buffer(const uint8_t *buf, int len)
559 {
560 #ifdef CONFIG_USER_ONLY
561     int ret;
562 
563     while (len > 0) {
564         ret = send(gdbserver_state.fd, buf, len, 0);
565         if (ret < 0) {
566             if (errno != EINTR)
567                 return;
568         } else {
569             buf += ret;
570             len -= ret;
571         }
572     }
573 #else
574     /* XXX this blocks entire thread. Rewrite to use
575      * qemu_chr_fe_write and background I/O callbacks */
576     qemu_chr_fe_write_all(&gdbserver_state.chr, buf, len);
577 #endif
578 }
579 
580 static inline int fromhex(int v)
581 {
582     if (v >= '0' && v <= '9')
583         return v - '0';
584     else if (v >= 'A' && v <= 'F')
585         return v - 'A' + 10;
586     else if (v >= 'a' && v <= 'f')
587         return v - 'a' + 10;
588     else
589         return 0;
590 }
591 
592 static inline int tohex(int v)
593 {
594     if (v < 10)
595         return v + '0';
596     else
597         return v - 10 + 'a';
598 }
599 
600 /* writes 2*len+1 bytes in buf */
601 static void memtohex(GString *buf, const uint8_t *mem, int len)
602 {
603     int i, c;
604     for(i = 0; i < len; i++) {
605         c = mem[i];
606         g_string_append_c(buf, tohex(c >> 4));
607         g_string_append_c(buf, tohex(c & 0xf));
608     }
609     g_string_append_c(buf, '\0');
610 }
611 
612 static void hextomem(GByteArray *mem, const char *buf, int len)
613 {
614     int i;
615 
616     for(i = 0; i < len; i++) {
617         guint8 byte = fromhex(buf[0]) << 4 | fromhex(buf[1]);
618         g_byte_array_append(mem, &byte, 1);
619         buf += 2;
620     }
621 }
622 
623 static void hexdump(const char *buf, int len,
624                     void (*trace_fn)(size_t ofs, char const *text))
625 {
626     char line_buffer[3 * 16 + 4 + 16 + 1];
627 
628     size_t i;
629     for (i = 0; i < len || (i & 0xF); ++i) {
630         size_t byte_ofs = i & 15;
631 
632         if (byte_ofs == 0) {
633             memset(line_buffer, ' ', 3 * 16 + 4 + 16);
634             line_buffer[3 * 16 + 4 + 16] = 0;
635         }
636 
637         size_t col_group = (i >> 2) & 3;
638         size_t hex_col = byte_ofs * 3 + col_group;
639         size_t txt_col = 3 * 16 + 4 + byte_ofs;
640 
641         if (i < len) {
642             char value = buf[i];
643 
644             line_buffer[hex_col + 0] = tohex((value >> 4) & 0xF);
645             line_buffer[hex_col + 1] = tohex((value >> 0) & 0xF);
646             line_buffer[txt_col + 0] = (value >= ' ' && value < 127)
647                     ? value
648                     : '.';
649         }
650 
651         if (byte_ofs == 0xF)
652             trace_fn(i & -16, line_buffer);
653     }
654 }
655 
656 /* return -1 if error, 0 if OK */
657 static int put_packet_binary(const char *buf, int len, bool dump)
658 {
659     int csum, i;
660     uint8_t footer[3];
661 
662     if (dump && trace_event_get_state_backends(TRACE_GDBSTUB_IO_BINARYREPLY)) {
663         hexdump(buf, len, trace_gdbstub_io_binaryreply);
664     }
665 
666     for(;;) {
667         g_byte_array_set_size(gdbserver_state.last_packet, 0);
668         g_byte_array_append(gdbserver_state.last_packet,
669                             (const uint8_t *) "$", 1);
670         g_byte_array_append(gdbserver_state.last_packet,
671                             (const uint8_t *) buf, len);
672         csum = 0;
673         for(i = 0; i < len; i++) {
674             csum += buf[i];
675         }
676         footer[0] = '#';
677         footer[1] = tohex((csum >> 4) & 0xf);
678         footer[2] = tohex((csum) & 0xf);
679         g_byte_array_append(gdbserver_state.last_packet, footer, 3);
680 
681         put_buffer(gdbserver_state.last_packet->data,
682                    gdbserver_state.last_packet->len);
683 
684 #ifdef CONFIG_USER_ONLY
685         i = get_char();
686         if (i < 0)
687             return -1;
688         if (i == '+')
689             break;
690 #else
691         break;
692 #endif
693     }
694     return 0;
695 }
696 
697 /* return -1 if error, 0 if OK */
698 static int put_packet(const char *buf)
699 {
700     trace_gdbstub_io_reply(buf);
701 
702     return put_packet_binary(buf, strlen(buf), false);
703 }
704 
705 static void put_strbuf(void)
706 {
707     put_packet(gdbserver_state.str_buf->str);
708 }
709 
710 /* Encode data using the encoding for 'x' packets.  */
711 static void memtox(GString *buf, const char *mem, int len)
712 {
713     char c;
714 
715     while (len--) {
716         c = *(mem++);
717         switch (c) {
718         case '#': case '$': case '*': case '}':
719             g_string_append_c(buf, '}');
720             g_string_append_c(buf, c ^ 0x20);
721             break;
722         default:
723             g_string_append_c(buf, c);
724             break;
725         }
726     }
727 }
728 
729 static uint32_t gdb_get_cpu_pid(CPUState *cpu)
730 {
731     /* TODO: In user mode, we should use the task state PID */
732     if (cpu->cluster_index == UNASSIGNED_CLUSTER_INDEX) {
733         /* Return the default process' PID */
734         int index = gdbserver_state.process_num - 1;
735         return gdbserver_state.processes[index].pid;
736     }
737     return cpu->cluster_index + 1;
738 }
739 
740 static GDBProcess *gdb_get_process(uint32_t pid)
741 {
742     int i;
743 
744     if (!pid) {
745         /* 0 means any process, we take the first one */
746         return &gdbserver_state.processes[0];
747     }
748 
749     for (i = 0; i < gdbserver_state.process_num; i++) {
750         if (gdbserver_state.processes[i].pid == pid) {
751             return &gdbserver_state.processes[i];
752         }
753     }
754 
755     return NULL;
756 }
757 
758 static GDBProcess *gdb_get_cpu_process(CPUState *cpu)
759 {
760     return gdb_get_process(gdb_get_cpu_pid(cpu));
761 }
762 
763 static CPUState *find_cpu(uint32_t thread_id)
764 {
765     CPUState *cpu;
766 
767     CPU_FOREACH(cpu) {
768         if (cpu_gdb_index(cpu) == thread_id) {
769             return cpu;
770         }
771     }
772 
773     return NULL;
774 }
775 
776 static CPUState *get_first_cpu_in_process(GDBProcess *process)
777 {
778     CPUState *cpu;
779 
780     CPU_FOREACH(cpu) {
781         if (gdb_get_cpu_pid(cpu) == process->pid) {
782             return cpu;
783         }
784     }
785 
786     return NULL;
787 }
788 
789 static CPUState *gdb_next_cpu_in_process(CPUState *cpu)
790 {
791     uint32_t pid = gdb_get_cpu_pid(cpu);
792     cpu = CPU_NEXT(cpu);
793 
794     while (cpu) {
795         if (gdb_get_cpu_pid(cpu) == pid) {
796             break;
797         }
798 
799         cpu = CPU_NEXT(cpu);
800     }
801 
802     return cpu;
803 }
804 
805 /* Return the cpu following @cpu, while ignoring unattached processes. */
806 static CPUState *gdb_next_attached_cpu(CPUState *cpu)
807 {
808     cpu = CPU_NEXT(cpu);
809 
810     while (cpu) {
811         if (gdb_get_cpu_process(cpu)->attached) {
812             break;
813         }
814 
815         cpu = CPU_NEXT(cpu);
816     }
817 
818     return cpu;
819 }
820 
821 /* Return the first attached cpu */
822 static CPUState *gdb_first_attached_cpu(void)
823 {
824     CPUState *cpu = first_cpu;
825     GDBProcess *process = gdb_get_cpu_process(cpu);
826 
827     if (!process->attached) {
828         return gdb_next_attached_cpu(cpu);
829     }
830 
831     return cpu;
832 }
833 
834 static CPUState *gdb_get_cpu(uint32_t pid, uint32_t tid)
835 {
836     GDBProcess *process;
837     CPUState *cpu;
838 
839     if (!pid && !tid) {
840         /* 0 means any process/thread, we take the first attached one */
841         return gdb_first_attached_cpu();
842     } else if (pid && !tid) {
843         /* any thread in a specific process */
844         process = gdb_get_process(pid);
845 
846         if (process == NULL) {
847             return NULL;
848         }
849 
850         if (!process->attached) {
851             return NULL;
852         }
853 
854         return get_first_cpu_in_process(process);
855     } else {
856         /* a specific thread */
857         cpu = find_cpu(tid);
858 
859         if (cpu == NULL) {
860             return NULL;
861         }
862 
863         process = gdb_get_cpu_process(cpu);
864 
865         if (pid && process->pid != pid) {
866             return NULL;
867         }
868 
869         if (!process->attached) {
870             return NULL;
871         }
872 
873         return cpu;
874     }
875 }
876 
877 static const char *get_feature_xml(const char *p, const char **newp,
878                                    GDBProcess *process)
879 {
880     size_t len;
881     int i;
882     const char *name;
883     CPUState *cpu = get_first_cpu_in_process(process);
884     CPUClass *cc = CPU_GET_CLASS(cpu);
885 
886     len = 0;
887     while (p[len] && p[len] != ':')
888         len++;
889     *newp = p + len;
890 
891     name = NULL;
892     if (strncmp(p, "target.xml", len) == 0) {
893         char *buf = process->target_xml;
894         const size_t buf_sz = sizeof(process->target_xml);
895 
896         /* Generate the XML description for this CPU.  */
897         if (!buf[0]) {
898             GDBRegisterState *r;
899 
900             pstrcat(buf, buf_sz,
901                     "<?xml version=\"1.0\"?>"
902                     "<!DOCTYPE target SYSTEM \"gdb-target.dtd\">"
903                     "<target>");
904             if (cc->gdb_arch_name) {
905                 gchar *arch = cc->gdb_arch_name(cpu);
906                 pstrcat(buf, buf_sz, "<architecture>");
907                 pstrcat(buf, buf_sz, arch);
908                 pstrcat(buf, buf_sz, "</architecture>");
909                 g_free(arch);
910             }
911             pstrcat(buf, buf_sz, "<xi:include href=\"");
912             pstrcat(buf, buf_sz, cc->gdb_core_xml_file);
913             pstrcat(buf, buf_sz, "\"/>");
914             for (r = cpu->gdb_regs; r; r = r->next) {
915                 pstrcat(buf, buf_sz, "<xi:include href=\"");
916                 pstrcat(buf, buf_sz, r->xml);
917                 pstrcat(buf, buf_sz, "\"/>");
918             }
919             pstrcat(buf, buf_sz, "</target>");
920         }
921         return buf;
922     }
923     if (cc->gdb_get_dynamic_xml) {
924         char *xmlname = g_strndup(p, len);
925         const char *xml = cc->gdb_get_dynamic_xml(cpu, xmlname);
926 
927         g_free(xmlname);
928         if (xml) {
929             return xml;
930         }
931     }
932     for (i = 0; ; i++) {
933         name = xml_builtin[i][0];
934         if (!name || (strncmp(name, p, len) == 0 && strlen(name) == len))
935             break;
936     }
937     return name ? xml_builtin[i][1] : NULL;
938 }
939 
940 static int gdb_read_register(CPUState *cpu, GByteArray *buf, int reg)
941 {
942     CPUClass *cc = CPU_GET_CLASS(cpu);
943     CPUArchState *env = cpu->env_ptr;
944     GDBRegisterState *r;
945 
946     if (reg < cc->gdb_num_core_regs) {
947         return cc->gdb_read_register(cpu, buf, reg);
948     }
949 
950     for (r = cpu->gdb_regs; r; r = r->next) {
951         if (r->base_reg <= reg && reg < r->base_reg + r->num_regs) {
952             return r->get_reg(env, buf, reg - r->base_reg);
953         }
954     }
955     return 0;
956 }
957 
958 static int gdb_write_register(CPUState *cpu, uint8_t *mem_buf, int reg)
959 {
960     CPUClass *cc = CPU_GET_CLASS(cpu);
961     CPUArchState *env = cpu->env_ptr;
962     GDBRegisterState *r;
963 
964     if (reg < cc->gdb_num_core_regs) {
965         return cc->gdb_write_register(cpu, mem_buf, reg);
966     }
967 
968     for (r = cpu->gdb_regs; r; r = r->next) {
969         if (r->base_reg <= reg && reg < r->base_reg + r->num_regs) {
970             return r->set_reg(env, mem_buf, reg - r->base_reg);
971         }
972     }
973     return 0;
974 }
975 
976 /* Register a supplemental set of CPU registers.  If g_pos is nonzero it
977    specifies the first register number and these registers are included in
978    a standard "g" packet.  Direction is relative to gdb, i.e. get_reg is
979    gdb reading a CPU register, and set_reg is gdb modifying a CPU register.
980  */
981 
982 void gdb_register_coprocessor(CPUState *cpu,
983                               gdb_get_reg_cb get_reg, gdb_set_reg_cb set_reg,
984                               int num_regs, const char *xml, int g_pos)
985 {
986     GDBRegisterState *s;
987     GDBRegisterState **p;
988 
989     p = &cpu->gdb_regs;
990     while (*p) {
991         /* Check for duplicates.  */
992         if (strcmp((*p)->xml, xml) == 0)
993             return;
994         p = &(*p)->next;
995     }
996 
997     s = g_new0(GDBRegisterState, 1);
998     s->base_reg = cpu->gdb_num_regs;
999     s->num_regs = num_regs;
1000     s->get_reg = get_reg;
1001     s->set_reg = set_reg;
1002     s->xml = xml;
1003 
1004     /* Add to end of list.  */
1005     cpu->gdb_num_regs += num_regs;
1006     *p = s;
1007     if (g_pos) {
1008         if (g_pos != s->base_reg) {
1009             error_report("Error: Bad gdb register numbering for '%s', "
1010                          "expected %d got %d", xml, g_pos, s->base_reg);
1011         } else {
1012             cpu->gdb_num_g_regs = cpu->gdb_num_regs;
1013         }
1014     }
1015 }
1016 
1017 static void gdb_process_breakpoint_remove_all(GDBProcess *p)
1018 {
1019     CPUState *cpu = get_first_cpu_in_process(p);
1020 
1021     while (cpu) {
1022         gdb_breakpoint_remove_all(cpu);
1023         cpu = gdb_next_cpu_in_process(cpu);
1024     }
1025 }
1026 
1027 
1028 static void gdb_set_cpu_pc(target_ulong pc)
1029 {
1030     CPUState *cpu = gdbserver_state.c_cpu;
1031 
1032     cpu_synchronize_state(cpu);
1033     cpu_set_pc(cpu, pc);
1034 }
1035 
1036 static void gdb_append_thread_id(CPUState *cpu, GString *buf)
1037 {
1038     if (gdbserver_state.multiprocess) {
1039         g_string_append_printf(buf, "p%02x.%02x",
1040                                gdb_get_cpu_pid(cpu), cpu_gdb_index(cpu));
1041     } else {
1042         g_string_append_printf(buf, "%02x", cpu_gdb_index(cpu));
1043     }
1044 }
1045 
1046 typedef enum GDBThreadIdKind {
1047     GDB_ONE_THREAD = 0,
1048     GDB_ALL_THREADS,     /* One process, all threads */
1049     GDB_ALL_PROCESSES,
1050     GDB_READ_THREAD_ERR
1051 } GDBThreadIdKind;
1052 
1053 static GDBThreadIdKind read_thread_id(const char *buf, const char **end_buf,
1054                                       uint32_t *pid, uint32_t *tid)
1055 {
1056     unsigned long p, t;
1057     int ret;
1058 
1059     if (*buf == 'p') {
1060         buf++;
1061         ret = qemu_strtoul(buf, &buf, 16, &p);
1062 
1063         if (ret) {
1064             return GDB_READ_THREAD_ERR;
1065         }
1066 
1067         /* Skip '.' */
1068         buf++;
1069     } else {
1070         p = 1;
1071     }
1072 
1073     ret = qemu_strtoul(buf, &buf, 16, &t);
1074 
1075     if (ret) {
1076         return GDB_READ_THREAD_ERR;
1077     }
1078 
1079     *end_buf = buf;
1080 
1081     if (p == -1) {
1082         return GDB_ALL_PROCESSES;
1083     }
1084 
1085     if (pid) {
1086         *pid = p;
1087     }
1088 
1089     if (t == -1) {
1090         return GDB_ALL_THREADS;
1091     }
1092 
1093     if (tid) {
1094         *tid = t;
1095     }
1096 
1097     return GDB_ONE_THREAD;
1098 }
1099 
1100 /**
1101  * gdb_handle_vcont - Parses and handles a vCont packet.
1102  * returns -ENOTSUP if a command is unsupported, -EINVAL or -ERANGE if there is
1103  *         a format error, 0 on success.
1104  */
1105 static int gdb_handle_vcont(const char *p)
1106 {
1107     int res, signal = 0;
1108     char cur_action;
1109     char *newstates;
1110     unsigned long tmp;
1111     uint32_t pid, tid;
1112     GDBProcess *process;
1113     CPUState *cpu;
1114     GDBThreadIdKind kind;
1115 #ifdef CONFIG_USER_ONLY
1116     int max_cpus = 1; /* global variable max_cpus exists only in system mode */
1117 
1118     CPU_FOREACH(cpu) {
1119         max_cpus = max_cpus <= cpu->cpu_index ? cpu->cpu_index + 1 : max_cpus;
1120     }
1121 #else
1122     MachineState *ms = MACHINE(qdev_get_machine());
1123     unsigned int max_cpus = ms->smp.max_cpus;
1124 #endif
1125     /* uninitialised CPUs stay 0 */
1126     newstates = g_new0(char, max_cpus);
1127 
1128     /* mark valid CPUs with 1 */
1129     CPU_FOREACH(cpu) {
1130         newstates[cpu->cpu_index] = 1;
1131     }
1132 
1133     /*
1134      * res keeps track of what error we are returning, with -ENOTSUP meaning
1135      * that the command is unknown or unsupported, thus returning an empty
1136      * packet, while -EINVAL and -ERANGE cause an E22 packet, due to invalid,
1137      *  or incorrect parameters passed.
1138      */
1139     res = 0;
1140     while (*p) {
1141         if (*p++ != ';') {
1142             res = -ENOTSUP;
1143             goto out;
1144         }
1145 
1146         cur_action = *p++;
1147         if (cur_action == 'C' || cur_action == 'S') {
1148             cur_action = qemu_tolower(cur_action);
1149             res = qemu_strtoul(p, &p, 16, &tmp);
1150             if (res) {
1151                 goto out;
1152             }
1153             signal = gdb_signal_to_target(tmp);
1154         } else if (cur_action != 'c' && cur_action != 's') {
1155             /* unknown/invalid/unsupported command */
1156             res = -ENOTSUP;
1157             goto out;
1158         }
1159 
1160         if (*p == '\0' || *p == ';') {
1161             /*
1162              * No thread specifier, action is on "all threads". The
1163              * specification is unclear regarding the process to act on. We
1164              * choose all processes.
1165              */
1166             kind = GDB_ALL_PROCESSES;
1167         } else if (*p++ == ':') {
1168             kind = read_thread_id(p, &p, &pid, &tid);
1169         } else {
1170             res = -ENOTSUP;
1171             goto out;
1172         }
1173 
1174         switch (kind) {
1175         case GDB_READ_THREAD_ERR:
1176             res = -EINVAL;
1177             goto out;
1178 
1179         case GDB_ALL_PROCESSES:
1180             cpu = gdb_first_attached_cpu();
1181             while (cpu) {
1182                 if (newstates[cpu->cpu_index] == 1) {
1183                     newstates[cpu->cpu_index] = cur_action;
1184                 }
1185 
1186                 cpu = gdb_next_attached_cpu(cpu);
1187             }
1188             break;
1189 
1190         case GDB_ALL_THREADS:
1191             process = gdb_get_process(pid);
1192 
1193             if (!process->attached) {
1194                 res = -EINVAL;
1195                 goto out;
1196             }
1197 
1198             cpu = get_first_cpu_in_process(process);
1199             while (cpu) {
1200                 if (newstates[cpu->cpu_index] == 1) {
1201                     newstates[cpu->cpu_index] = cur_action;
1202                 }
1203 
1204                 cpu = gdb_next_cpu_in_process(cpu);
1205             }
1206             break;
1207 
1208         case GDB_ONE_THREAD:
1209             cpu = gdb_get_cpu(pid, tid);
1210 
1211             /* invalid CPU/thread specified */
1212             if (!cpu) {
1213                 res = -EINVAL;
1214                 goto out;
1215             }
1216 
1217             /* only use if no previous match occourred */
1218             if (newstates[cpu->cpu_index] == 1) {
1219                 newstates[cpu->cpu_index] = cur_action;
1220             }
1221             break;
1222         }
1223     }
1224     gdbserver_state.signal = signal;
1225     gdb_continue_partial(newstates);
1226 
1227 out:
1228     g_free(newstates);
1229 
1230     return res;
1231 }
1232 
1233 typedef union GdbCmdVariant {
1234     const char *data;
1235     uint8_t opcode;
1236     unsigned long val_ul;
1237     unsigned long long val_ull;
1238     struct {
1239         GDBThreadIdKind kind;
1240         uint32_t pid;
1241         uint32_t tid;
1242     } thread_id;
1243 } GdbCmdVariant;
1244 
1245 #define get_param(p, i)    (&g_array_index(p, GdbCmdVariant, i))
1246 
1247 static const char *cmd_next_param(const char *param, const char delimiter)
1248 {
1249     static const char all_delimiters[] = ",;:=";
1250     char curr_delimiters[2] = {0};
1251     const char *delimiters;
1252 
1253     if (delimiter == '?') {
1254         delimiters = all_delimiters;
1255     } else if (delimiter == '0') {
1256         return strchr(param, '\0');
1257     } else if (delimiter == '.' && *param) {
1258         return param + 1;
1259     } else {
1260         curr_delimiters[0] = delimiter;
1261         delimiters = curr_delimiters;
1262     }
1263 
1264     param += strcspn(param, delimiters);
1265     if (*param) {
1266         param++;
1267     }
1268     return param;
1269 }
1270 
1271 static int cmd_parse_params(const char *data, const char *schema,
1272                             GArray *params)
1273 {
1274     const char *curr_schema, *curr_data;
1275 
1276     g_assert(schema);
1277     g_assert(params->len == 0);
1278 
1279     curr_schema = schema;
1280     curr_data = data;
1281     while (curr_schema[0] && curr_schema[1] && *curr_data) {
1282         GdbCmdVariant this_param;
1283 
1284         switch (curr_schema[0]) {
1285         case 'l':
1286             if (qemu_strtoul(curr_data, &curr_data, 16,
1287                              &this_param.val_ul)) {
1288                 return -EINVAL;
1289             }
1290             curr_data = cmd_next_param(curr_data, curr_schema[1]);
1291             g_array_append_val(params, this_param);
1292             break;
1293         case 'L':
1294             if (qemu_strtou64(curr_data, &curr_data, 16,
1295                               (uint64_t *)&this_param.val_ull)) {
1296                 return -EINVAL;
1297             }
1298             curr_data = cmd_next_param(curr_data, curr_schema[1]);
1299             g_array_append_val(params, this_param);
1300             break;
1301         case 's':
1302             this_param.data = curr_data;
1303             curr_data = cmd_next_param(curr_data, curr_schema[1]);
1304             g_array_append_val(params, this_param);
1305             break;
1306         case 'o':
1307             this_param.opcode = *(uint8_t *)curr_data;
1308             curr_data = cmd_next_param(curr_data, curr_schema[1]);
1309             g_array_append_val(params, this_param);
1310             break;
1311         case 't':
1312             this_param.thread_id.kind =
1313                 read_thread_id(curr_data, &curr_data,
1314                                &this_param.thread_id.pid,
1315                                &this_param.thread_id.tid);
1316             curr_data = cmd_next_param(curr_data, curr_schema[1]);
1317             g_array_append_val(params, this_param);
1318             break;
1319         case '?':
1320             curr_data = cmd_next_param(curr_data, curr_schema[1]);
1321             break;
1322         default:
1323             return -EINVAL;
1324         }
1325         curr_schema += 2;
1326     }
1327 
1328     return 0;
1329 }
1330 
1331 typedef void (*GdbCmdHandler)(GArray *params, void *user_ctx);
1332 
1333 /*
1334  * cmd_startswith -> cmd is compared using startswith
1335  *
1336  *
1337  * schema definitions:
1338  * Each schema parameter entry consists of 2 chars,
1339  * the first char represents the parameter type handling
1340  * the second char represents the delimiter for the next parameter
1341  *
1342  * Currently supported schema types:
1343  * 'l' -> unsigned long (stored in .val_ul)
1344  * 'L' -> unsigned long long (stored in .val_ull)
1345  * 's' -> string (stored in .data)
1346  * 'o' -> single char (stored in .opcode)
1347  * 't' -> thread id (stored in .thread_id)
1348  * '?' -> skip according to delimiter
1349  *
1350  * Currently supported delimiters:
1351  * '?' -> Stop at any delimiter (",;:=\0")
1352  * '0' -> Stop at "\0"
1353  * '.' -> Skip 1 char unless reached "\0"
1354  * Any other value is treated as the delimiter value itself
1355  */
1356 typedef struct GdbCmdParseEntry {
1357     GdbCmdHandler handler;
1358     const char *cmd;
1359     bool cmd_startswith;
1360     const char *schema;
1361 } GdbCmdParseEntry;
1362 
1363 static inline int startswith(const char *string, const char *pattern)
1364 {
1365   return !strncmp(string, pattern, strlen(pattern));
1366 }
1367 
1368 static int process_string_cmd(void *user_ctx, const char *data,
1369                               const GdbCmdParseEntry *cmds, int num_cmds)
1370 {
1371     int i;
1372     g_autoptr(GArray) params = g_array_new(false, true, sizeof(GdbCmdVariant));
1373 
1374     if (!cmds) {
1375         return -1;
1376     }
1377 
1378     for (i = 0; i < num_cmds; i++) {
1379         const GdbCmdParseEntry *cmd = &cmds[i];
1380         g_assert(cmd->handler && cmd->cmd);
1381 
1382         if ((cmd->cmd_startswith && !startswith(data, cmd->cmd)) ||
1383             (!cmd->cmd_startswith && strcmp(cmd->cmd, data))) {
1384             continue;
1385         }
1386 
1387         if (cmd->schema) {
1388             if (cmd_parse_params(&data[strlen(cmd->cmd)],
1389                                  cmd->schema, params)) {
1390                 return -1;
1391             }
1392         }
1393 
1394         cmd->handler(params, user_ctx);
1395         return 0;
1396     }
1397 
1398     return -1;
1399 }
1400 
1401 static void run_cmd_parser(const char *data, const GdbCmdParseEntry *cmd)
1402 {
1403     if (!data) {
1404         return;
1405     }
1406 
1407     g_string_set_size(gdbserver_state.str_buf, 0);
1408     g_byte_array_set_size(gdbserver_state.mem_buf, 0);
1409 
1410     /* In case there was an error during the command parsing we must
1411     * send a NULL packet to indicate the command is not supported */
1412     if (process_string_cmd(NULL, data, cmd, 1)) {
1413         put_packet("");
1414     }
1415 }
1416 
1417 static void handle_detach(GArray *params, void *user_ctx)
1418 {
1419     GDBProcess *process;
1420     uint32_t pid = 1;
1421 
1422     if (gdbserver_state.multiprocess) {
1423         if (!params->len) {
1424             put_packet("E22");
1425             return;
1426         }
1427 
1428         pid = get_param(params, 0)->val_ul;
1429     }
1430 
1431     process = gdb_get_process(pid);
1432     gdb_process_breakpoint_remove_all(process);
1433     process->attached = false;
1434 
1435     if (pid == gdb_get_cpu_pid(gdbserver_state.c_cpu)) {
1436         gdbserver_state.c_cpu = gdb_first_attached_cpu();
1437     }
1438 
1439     if (pid == gdb_get_cpu_pid(gdbserver_state.g_cpu)) {
1440         gdbserver_state.g_cpu = gdb_first_attached_cpu();
1441     }
1442 
1443     if (!gdbserver_state.c_cpu) {
1444         /* No more process attached */
1445         gdb_syscall_mode = GDB_SYS_DISABLED;
1446         gdb_continue();
1447     }
1448     put_packet("OK");
1449 }
1450 
1451 static void handle_thread_alive(GArray *params, void *user_ctx)
1452 {
1453     CPUState *cpu;
1454 
1455     if (!params->len) {
1456         put_packet("E22");
1457         return;
1458     }
1459 
1460     if (get_param(params, 0)->thread_id.kind == GDB_READ_THREAD_ERR) {
1461         put_packet("E22");
1462         return;
1463     }
1464 
1465     cpu = gdb_get_cpu(get_param(params, 0)->thread_id.pid,
1466                       get_param(params, 0)->thread_id.tid);
1467     if (!cpu) {
1468         put_packet("E22");
1469         return;
1470     }
1471 
1472     put_packet("OK");
1473 }
1474 
1475 static void handle_continue(GArray *params, void *user_ctx)
1476 {
1477     if (params->len) {
1478         gdb_set_cpu_pc(get_param(params, 0)->val_ull);
1479     }
1480 
1481     gdbserver_state.signal = 0;
1482     gdb_continue();
1483 }
1484 
1485 static void handle_cont_with_sig(GArray *params, void *user_ctx)
1486 {
1487     unsigned long signal = 0;
1488 
1489     /*
1490      * Note: C sig;[addr] is currently unsupported and we simply
1491      *       omit the addr parameter
1492      */
1493     if (params->len) {
1494         signal = get_param(params, 0)->val_ul;
1495     }
1496 
1497     gdbserver_state.signal = gdb_signal_to_target(signal);
1498     if (gdbserver_state.signal == -1) {
1499         gdbserver_state.signal = 0;
1500     }
1501     gdb_continue();
1502 }
1503 
1504 static void handle_set_thread(GArray *params, void *user_ctx)
1505 {
1506     CPUState *cpu;
1507 
1508     if (params->len != 2) {
1509         put_packet("E22");
1510         return;
1511     }
1512 
1513     if (get_param(params, 1)->thread_id.kind == GDB_READ_THREAD_ERR) {
1514         put_packet("E22");
1515         return;
1516     }
1517 
1518     if (get_param(params, 1)->thread_id.kind != GDB_ONE_THREAD) {
1519         put_packet("OK");
1520         return;
1521     }
1522 
1523     cpu = gdb_get_cpu(get_param(params, 1)->thread_id.pid,
1524                       get_param(params, 1)->thread_id.tid);
1525     if (!cpu) {
1526         put_packet("E22");
1527         return;
1528     }
1529 
1530     /*
1531      * Note: This command is deprecated and modern gdb's will be using the
1532      *       vCont command instead.
1533      */
1534     switch (get_param(params, 0)->opcode) {
1535     case 'c':
1536         gdbserver_state.c_cpu = cpu;
1537         put_packet("OK");
1538         break;
1539     case 'g':
1540         gdbserver_state.g_cpu = cpu;
1541         put_packet("OK");
1542         break;
1543     default:
1544         put_packet("E22");
1545         break;
1546     }
1547 }
1548 
1549 static void handle_insert_bp(GArray *params, void *user_ctx)
1550 {
1551     int res;
1552 
1553     if (params->len != 3) {
1554         put_packet("E22");
1555         return;
1556     }
1557 
1558     res = gdb_breakpoint_insert(gdbserver_state.c_cpu,
1559                                 get_param(params, 0)->val_ul,
1560                                 get_param(params, 1)->val_ull,
1561                                 get_param(params, 2)->val_ull);
1562     if (res >= 0) {
1563         put_packet("OK");
1564         return;
1565     } else if (res == -ENOSYS) {
1566         put_packet("");
1567         return;
1568     }
1569 
1570     put_packet("E22");
1571 }
1572 
1573 static void handle_remove_bp(GArray *params, void *user_ctx)
1574 {
1575     int res;
1576 
1577     if (params->len != 3) {
1578         put_packet("E22");
1579         return;
1580     }
1581 
1582     res = gdb_breakpoint_remove(gdbserver_state.c_cpu,
1583                                 get_param(params, 0)->val_ul,
1584                                 get_param(params, 1)->val_ull,
1585                                 get_param(params, 2)->val_ull);
1586     if (res >= 0) {
1587         put_packet("OK");
1588         return;
1589     } else if (res == -ENOSYS) {
1590         put_packet("");
1591         return;
1592     }
1593 
1594     put_packet("E22");
1595 }
1596 
1597 /*
1598  * handle_set/get_reg
1599  *
1600  * Older gdb are really dumb, and don't use 'G/g' if 'P/p' is available.
1601  * This works, but can be very slow. Anything new enough to understand
1602  * XML also knows how to use this properly. However to use this we
1603  * need to define a local XML file as well as be talking to a
1604  * reasonably modern gdb. Responding with an empty packet will cause
1605  * the remote gdb to fallback to older methods.
1606  */
1607 
1608 static void handle_set_reg(GArray *params, void *user_ctx)
1609 {
1610     int reg_size;
1611 
1612     if (!gdb_has_xml) {
1613         put_packet("");
1614         return;
1615     }
1616 
1617     if (params->len != 2) {
1618         put_packet("E22");
1619         return;
1620     }
1621 
1622     reg_size = strlen(get_param(params, 1)->data) / 2;
1623     hextomem(gdbserver_state.mem_buf, get_param(params, 1)->data, reg_size);
1624     gdb_write_register(gdbserver_state.g_cpu, gdbserver_state.mem_buf->data,
1625                        get_param(params, 0)->val_ull);
1626     put_packet("OK");
1627 }
1628 
1629 static void handle_get_reg(GArray *params, void *user_ctx)
1630 {
1631     int reg_size;
1632 
1633     if (!gdb_has_xml) {
1634         put_packet("");
1635         return;
1636     }
1637 
1638     if (!params->len) {
1639         put_packet("E14");
1640         return;
1641     }
1642 
1643     reg_size = gdb_read_register(gdbserver_state.g_cpu,
1644                                  gdbserver_state.mem_buf,
1645                                  get_param(params, 0)->val_ull);
1646     if (!reg_size) {
1647         put_packet("E14");
1648         return;
1649     } else {
1650         g_byte_array_set_size(gdbserver_state.mem_buf, reg_size);
1651     }
1652 
1653     memtohex(gdbserver_state.str_buf, gdbserver_state.mem_buf->data, reg_size);
1654     put_strbuf();
1655 }
1656 
1657 static void handle_write_mem(GArray *params, void *user_ctx)
1658 {
1659     if (params->len != 3) {
1660         put_packet("E22");
1661         return;
1662     }
1663 
1664     /* hextomem() reads 2*len bytes */
1665     if (get_param(params, 1)->val_ull >
1666         strlen(get_param(params, 2)->data) / 2) {
1667         put_packet("E22");
1668         return;
1669     }
1670 
1671     hextomem(gdbserver_state.mem_buf, get_param(params, 2)->data,
1672              get_param(params, 1)->val_ull);
1673     if (target_memory_rw_debug(gdbserver_state.g_cpu,
1674                                get_param(params, 0)->val_ull,
1675                                gdbserver_state.mem_buf->data,
1676                                gdbserver_state.mem_buf->len, true)) {
1677         put_packet("E14");
1678         return;
1679     }
1680 
1681     put_packet("OK");
1682 }
1683 
1684 static void handle_read_mem(GArray *params, void *user_ctx)
1685 {
1686     if (params->len != 2) {
1687         put_packet("E22");
1688         return;
1689     }
1690 
1691     /* memtohex() doubles the required space */
1692     if (get_param(params, 1)->val_ull > MAX_PACKET_LENGTH / 2) {
1693         put_packet("E22");
1694         return;
1695     }
1696 
1697     g_byte_array_set_size(gdbserver_state.mem_buf,
1698                           get_param(params, 1)->val_ull);
1699 
1700     if (target_memory_rw_debug(gdbserver_state.g_cpu,
1701                                get_param(params, 0)->val_ull,
1702                                gdbserver_state.mem_buf->data,
1703                                gdbserver_state.mem_buf->len, false)) {
1704         put_packet("E14");
1705         return;
1706     }
1707 
1708     memtohex(gdbserver_state.str_buf, gdbserver_state.mem_buf->data,
1709              gdbserver_state.mem_buf->len);
1710     put_strbuf();
1711 }
1712 
1713 static void handle_write_all_regs(GArray *params, void *user_ctx)
1714 {
1715     target_ulong addr, len;
1716     uint8_t *registers;
1717     int reg_size;
1718 
1719     if (!params->len) {
1720         return;
1721     }
1722 
1723     cpu_synchronize_state(gdbserver_state.g_cpu);
1724     len = strlen(get_param(params, 0)->data) / 2;
1725     hextomem(gdbserver_state.mem_buf, get_param(params, 0)->data, len);
1726     registers = gdbserver_state.mem_buf->data;
1727     for (addr = 0; addr < gdbserver_state.g_cpu->gdb_num_g_regs && len > 0;
1728          addr++) {
1729         reg_size = gdb_write_register(gdbserver_state.g_cpu, registers, addr);
1730         len -= reg_size;
1731         registers += reg_size;
1732     }
1733     put_packet("OK");
1734 }
1735 
1736 static void handle_read_all_regs(GArray *params, void *user_ctx)
1737 {
1738     target_ulong addr, len;
1739 
1740     cpu_synchronize_state(gdbserver_state.g_cpu);
1741     g_byte_array_set_size(gdbserver_state.mem_buf, 0);
1742     len = 0;
1743     for (addr = 0; addr < gdbserver_state.g_cpu->gdb_num_g_regs; addr++) {
1744         len += gdb_read_register(gdbserver_state.g_cpu,
1745                                  gdbserver_state.mem_buf,
1746                                  addr);
1747     }
1748     g_assert(len == gdbserver_state.mem_buf->len);
1749 
1750     memtohex(gdbserver_state.str_buf, gdbserver_state.mem_buf->data, len);
1751     put_strbuf();
1752 }
1753 
1754 static void handle_file_io(GArray *params, void *user_ctx)
1755 {
1756     if (params->len >= 1 && gdbserver_state.current_syscall_cb) {
1757         uint64_t ret;
1758         int err;
1759 
1760         ret = get_param(params, 0)->val_ull;
1761         if (params->len >= 2) {
1762             err = get_param(params, 1)->val_ull;
1763         } else {
1764             err = 0;
1765         }
1766 
1767         /* Convert GDB error numbers back to host error numbers. */
1768 #define E(X)  case GDB_E##X: err = E##X; break
1769         switch (err) {
1770         case 0:
1771             break;
1772         E(PERM);
1773         E(NOENT);
1774         E(INTR);
1775         E(BADF);
1776         E(ACCES);
1777         E(FAULT);
1778         E(BUSY);
1779         E(EXIST);
1780         E(NODEV);
1781         E(NOTDIR);
1782         E(ISDIR);
1783         E(INVAL);
1784         E(NFILE);
1785         E(MFILE);
1786         E(FBIG);
1787         E(NOSPC);
1788         E(SPIPE);
1789         E(ROFS);
1790         E(NAMETOOLONG);
1791         default:
1792             err = EINVAL;
1793             break;
1794         }
1795 #undef E
1796 
1797         gdbserver_state.current_syscall_cb(gdbserver_state.c_cpu, ret, err);
1798         gdbserver_state.current_syscall_cb = NULL;
1799     }
1800 
1801     if (params->len >= 3 && get_param(params, 2)->opcode == (uint8_t)'C') {
1802         put_packet("T02");
1803         return;
1804     }
1805 
1806     gdb_continue();
1807 }
1808 
1809 static void handle_step(GArray *params, void *user_ctx)
1810 {
1811     if (params->len) {
1812         gdb_set_cpu_pc((target_ulong)get_param(params, 0)->val_ull);
1813     }
1814 
1815     cpu_single_step(gdbserver_state.c_cpu, gdbserver_state.sstep_flags);
1816     gdb_continue();
1817 }
1818 
1819 static void handle_backward(GArray *params, void *user_ctx)
1820 {
1821     if (!stub_can_reverse()) {
1822         put_packet("E22");
1823     }
1824     if (params->len == 1) {
1825         switch (get_param(params, 0)->opcode) {
1826         case 's':
1827             if (replay_reverse_step()) {
1828                 gdb_continue();
1829             } else {
1830                 put_packet("E14");
1831             }
1832             return;
1833         case 'c':
1834             if (replay_reverse_continue()) {
1835                 gdb_continue();
1836             } else {
1837                 put_packet("E14");
1838             }
1839             return;
1840         }
1841     }
1842 
1843     /* Default invalid command */
1844     put_packet("");
1845 }
1846 
1847 static void handle_v_cont_query(GArray *params, void *user_ctx)
1848 {
1849     put_packet("vCont;c;C;s;S");
1850 }
1851 
1852 static void handle_v_cont(GArray *params, void *user_ctx)
1853 {
1854     int res;
1855 
1856     if (!params->len) {
1857         return;
1858     }
1859 
1860     res = gdb_handle_vcont(get_param(params, 0)->data);
1861     if ((res == -EINVAL) || (res == -ERANGE)) {
1862         put_packet("E22");
1863     } else if (res) {
1864         put_packet("");
1865     }
1866 }
1867 
1868 static void handle_v_attach(GArray *params, void *user_ctx)
1869 {
1870     GDBProcess *process;
1871     CPUState *cpu;
1872 
1873     g_string_assign(gdbserver_state.str_buf, "E22");
1874     if (!params->len) {
1875         goto cleanup;
1876     }
1877 
1878     process = gdb_get_process(get_param(params, 0)->val_ul);
1879     if (!process) {
1880         goto cleanup;
1881     }
1882 
1883     cpu = get_first_cpu_in_process(process);
1884     if (!cpu) {
1885         goto cleanup;
1886     }
1887 
1888     process->attached = true;
1889     gdbserver_state.g_cpu = cpu;
1890     gdbserver_state.c_cpu = cpu;
1891 
1892     g_string_printf(gdbserver_state.str_buf, "T%02xthread:", GDB_SIGNAL_TRAP);
1893     gdb_append_thread_id(cpu, gdbserver_state.str_buf);
1894     g_string_append_c(gdbserver_state.str_buf, ';');
1895 cleanup:
1896     put_strbuf();
1897 }
1898 
1899 static void handle_v_kill(GArray *params, void *user_ctx)
1900 {
1901     /* Kill the target */
1902     put_packet("OK");
1903     error_report("QEMU: Terminated via GDBstub");
1904     gdb_exit(0);
1905     exit(0);
1906 }
1907 
1908 static const GdbCmdParseEntry gdb_v_commands_table[] = {
1909     /* Order is important if has same prefix */
1910     {
1911         .handler = handle_v_cont_query,
1912         .cmd = "Cont?",
1913         .cmd_startswith = 1
1914     },
1915     {
1916         .handler = handle_v_cont,
1917         .cmd = "Cont",
1918         .cmd_startswith = 1,
1919         .schema = "s0"
1920     },
1921     {
1922         .handler = handle_v_attach,
1923         .cmd = "Attach;",
1924         .cmd_startswith = 1,
1925         .schema = "l0"
1926     },
1927     {
1928         .handler = handle_v_kill,
1929         .cmd = "Kill;",
1930         .cmd_startswith = 1
1931     },
1932 };
1933 
1934 static void handle_v_commands(GArray *params, void *user_ctx)
1935 {
1936     if (!params->len) {
1937         return;
1938     }
1939 
1940     if (process_string_cmd(NULL, get_param(params, 0)->data,
1941                            gdb_v_commands_table,
1942                            ARRAY_SIZE(gdb_v_commands_table))) {
1943         put_packet("");
1944     }
1945 }
1946 
1947 static void handle_query_qemu_sstepbits(GArray *params, void *user_ctx)
1948 {
1949     g_string_printf(gdbserver_state.str_buf, "ENABLE=%x", SSTEP_ENABLE);
1950 
1951     if (gdbserver_state.supported_sstep_flags & SSTEP_NOIRQ) {
1952         g_string_append_printf(gdbserver_state.str_buf, ",NOIRQ=%x",
1953                                SSTEP_NOIRQ);
1954     }
1955 
1956     if (gdbserver_state.supported_sstep_flags & SSTEP_NOTIMER) {
1957         g_string_append_printf(gdbserver_state.str_buf, ",NOTIMER=%x",
1958                                SSTEP_NOTIMER);
1959     }
1960 
1961     put_strbuf();
1962 }
1963 
1964 static void handle_set_qemu_sstep(GArray *params, void *user_ctx)
1965 {
1966     int new_sstep_flags;
1967 
1968     if (!params->len) {
1969         return;
1970     }
1971 
1972     new_sstep_flags = get_param(params, 0)->val_ul;
1973 
1974     if (new_sstep_flags  & ~gdbserver_state.supported_sstep_flags) {
1975         put_packet("E22");
1976         return;
1977     }
1978 
1979     gdbserver_state.sstep_flags = new_sstep_flags;
1980     put_packet("OK");
1981 }
1982 
1983 static void handle_query_qemu_sstep(GArray *params, void *user_ctx)
1984 {
1985     g_string_printf(gdbserver_state.str_buf, "0x%x",
1986                     gdbserver_state.sstep_flags);
1987     put_strbuf();
1988 }
1989 
1990 static void handle_query_curr_tid(GArray *params, void *user_ctx)
1991 {
1992     CPUState *cpu;
1993     GDBProcess *process;
1994 
1995     /*
1996      * "Current thread" remains vague in the spec, so always return
1997      * the first thread of the current process (gdb returns the
1998      * first thread).
1999      */
2000     process = gdb_get_cpu_process(gdbserver_state.g_cpu);
2001     cpu = get_first_cpu_in_process(process);
2002     g_string_assign(gdbserver_state.str_buf, "QC");
2003     gdb_append_thread_id(cpu, gdbserver_state.str_buf);
2004     put_strbuf();
2005 }
2006 
2007 static void handle_query_threads(GArray *params, void *user_ctx)
2008 {
2009     if (!gdbserver_state.query_cpu) {
2010         put_packet("l");
2011         return;
2012     }
2013 
2014     g_string_assign(gdbserver_state.str_buf, "m");
2015     gdb_append_thread_id(gdbserver_state.query_cpu, gdbserver_state.str_buf);
2016     put_strbuf();
2017     gdbserver_state.query_cpu = gdb_next_attached_cpu(gdbserver_state.query_cpu);
2018 }
2019 
2020 static void handle_query_first_threads(GArray *params, void *user_ctx)
2021 {
2022     gdbserver_state.query_cpu = gdb_first_attached_cpu();
2023     handle_query_threads(params, user_ctx);
2024 }
2025 
2026 static void handle_query_thread_extra(GArray *params, void *user_ctx)
2027 {
2028     g_autoptr(GString) rs = g_string_new(NULL);
2029     CPUState *cpu;
2030 
2031     if (!params->len ||
2032         get_param(params, 0)->thread_id.kind == GDB_READ_THREAD_ERR) {
2033         put_packet("E22");
2034         return;
2035     }
2036 
2037     cpu = gdb_get_cpu(get_param(params, 0)->thread_id.pid,
2038                       get_param(params, 0)->thread_id.tid);
2039     if (!cpu) {
2040         return;
2041     }
2042 
2043     cpu_synchronize_state(cpu);
2044 
2045     if (gdbserver_state.multiprocess && (gdbserver_state.process_num > 1)) {
2046         /* Print the CPU model and name in multiprocess mode */
2047         ObjectClass *oc = object_get_class(OBJECT(cpu));
2048         const char *cpu_model = object_class_get_name(oc);
2049         const char *cpu_name =
2050             object_get_canonical_path_component(OBJECT(cpu));
2051         g_string_printf(rs, "%s %s [%s]", cpu_model, cpu_name,
2052                         cpu->halted ? "halted " : "running");
2053     } else {
2054         g_string_printf(rs, "CPU#%d [%s]", cpu->cpu_index,
2055                         cpu->halted ? "halted " : "running");
2056     }
2057     trace_gdbstub_op_extra_info(rs->str);
2058     memtohex(gdbserver_state.str_buf, (uint8_t *)rs->str, rs->len);
2059     put_strbuf();
2060 }
2061 
2062 #ifdef CONFIG_USER_ONLY
2063 static void handle_query_offsets(GArray *params, void *user_ctx)
2064 {
2065     TaskState *ts;
2066 
2067     ts = gdbserver_state.c_cpu->opaque;
2068     g_string_printf(gdbserver_state.str_buf,
2069                     "Text=" TARGET_ABI_FMT_lx
2070                     ";Data=" TARGET_ABI_FMT_lx
2071                     ";Bss=" TARGET_ABI_FMT_lx,
2072                     ts->info->code_offset,
2073                     ts->info->data_offset,
2074                     ts->info->data_offset);
2075     put_strbuf();
2076 }
2077 #else
2078 static void handle_query_rcmd(GArray *params, void *user_ctx)
2079 {
2080     const guint8 zero = 0;
2081     int len;
2082 
2083     if (!params->len) {
2084         put_packet("E22");
2085         return;
2086     }
2087 
2088     len = strlen(get_param(params, 0)->data);
2089     if (len % 2) {
2090         put_packet("E01");
2091         return;
2092     }
2093 
2094     g_assert(gdbserver_state.mem_buf->len == 0);
2095     len = len / 2;
2096     hextomem(gdbserver_state.mem_buf, get_param(params, 0)->data, len);
2097     g_byte_array_append(gdbserver_state.mem_buf, &zero, 1);
2098     qemu_chr_be_write(gdbserver_state.mon_chr, gdbserver_state.mem_buf->data,
2099                       gdbserver_state.mem_buf->len);
2100     put_packet("OK");
2101 }
2102 #endif
2103 
2104 static void handle_query_supported(GArray *params, void *user_ctx)
2105 {
2106     CPUClass *cc;
2107 
2108     g_string_printf(gdbserver_state.str_buf, "PacketSize=%x", MAX_PACKET_LENGTH);
2109     cc = CPU_GET_CLASS(first_cpu);
2110     if (cc->gdb_core_xml_file) {
2111         g_string_append(gdbserver_state.str_buf, ";qXfer:features:read+");
2112     }
2113 
2114     if (stub_can_reverse()) {
2115         g_string_append(gdbserver_state.str_buf,
2116             ";ReverseStep+;ReverseContinue+");
2117     }
2118 
2119 #ifdef CONFIG_USER_ONLY
2120     if (gdbserver_state.c_cpu->opaque) {
2121         g_string_append(gdbserver_state.str_buf, ";qXfer:auxv:read+");
2122     }
2123 #endif
2124 
2125     if (params->len &&
2126         strstr(get_param(params, 0)->data, "multiprocess+")) {
2127         gdbserver_state.multiprocess = true;
2128     }
2129 
2130     g_string_append(gdbserver_state.str_buf, ";vContSupported+;multiprocess+");
2131     put_strbuf();
2132 }
2133 
2134 static void handle_query_xfer_features(GArray *params, void *user_ctx)
2135 {
2136     GDBProcess *process;
2137     CPUClass *cc;
2138     unsigned long len, total_len, addr;
2139     const char *xml;
2140     const char *p;
2141 
2142     if (params->len < 3) {
2143         put_packet("E22");
2144         return;
2145     }
2146 
2147     process = gdb_get_cpu_process(gdbserver_state.g_cpu);
2148     cc = CPU_GET_CLASS(gdbserver_state.g_cpu);
2149     if (!cc->gdb_core_xml_file) {
2150         put_packet("");
2151         return;
2152     }
2153 
2154     gdb_has_xml = true;
2155     p = get_param(params, 0)->data;
2156     xml = get_feature_xml(p, &p, process);
2157     if (!xml) {
2158         put_packet("E00");
2159         return;
2160     }
2161 
2162     addr = get_param(params, 1)->val_ul;
2163     len = get_param(params, 2)->val_ul;
2164     total_len = strlen(xml);
2165     if (addr > total_len) {
2166         put_packet("E00");
2167         return;
2168     }
2169 
2170     if (len > (MAX_PACKET_LENGTH - 5) / 2) {
2171         len = (MAX_PACKET_LENGTH - 5) / 2;
2172     }
2173 
2174     if (len < total_len - addr) {
2175         g_string_assign(gdbserver_state.str_buf, "m");
2176         memtox(gdbserver_state.str_buf, xml + addr, len);
2177     } else {
2178         g_string_assign(gdbserver_state.str_buf, "l");
2179         memtox(gdbserver_state.str_buf, xml + addr, total_len - addr);
2180     }
2181 
2182     put_packet_binary(gdbserver_state.str_buf->str,
2183                       gdbserver_state.str_buf->len, true);
2184 }
2185 
2186 #if defined(CONFIG_USER_ONLY) && defined(CONFIG_LINUX_USER)
2187 static void handle_query_xfer_auxv(GArray *params, void *user_ctx)
2188 {
2189     TaskState *ts;
2190     unsigned long offset, len, saved_auxv, auxv_len;
2191 
2192     if (params->len < 2) {
2193         put_packet("E22");
2194         return;
2195     }
2196 
2197     offset = get_param(params, 0)->val_ul;
2198     len = get_param(params, 1)->val_ul;
2199     ts = gdbserver_state.c_cpu->opaque;
2200     saved_auxv = ts->info->saved_auxv;
2201     auxv_len = ts->info->auxv_len;
2202 
2203     if (offset >= auxv_len) {
2204         put_packet("E00");
2205         return;
2206     }
2207 
2208     if (len > (MAX_PACKET_LENGTH - 5) / 2) {
2209         len = (MAX_PACKET_LENGTH - 5) / 2;
2210     }
2211 
2212     if (len < auxv_len - offset) {
2213         g_string_assign(gdbserver_state.str_buf, "m");
2214     } else {
2215         g_string_assign(gdbserver_state.str_buf, "l");
2216         len = auxv_len - offset;
2217     }
2218 
2219     g_byte_array_set_size(gdbserver_state.mem_buf, len);
2220     if (target_memory_rw_debug(gdbserver_state.g_cpu, saved_auxv + offset,
2221                                gdbserver_state.mem_buf->data, len, false)) {
2222         put_packet("E14");
2223         return;
2224     }
2225 
2226     memtox(gdbserver_state.str_buf,
2227            (const char *)gdbserver_state.mem_buf->data, len);
2228     put_packet_binary(gdbserver_state.str_buf->str,
2229                       gdbserver_state.str_buf->len, true);
2230 }
2231 #endif
2232 
2233 static void handle_query_attached(GArray *params, void *user_ctx)
2234 {
2235     put_packet(GDB_ATTACHED);
2236 }
2237 
2238 static void handle_query_qemu_supported(GArray *params, void *user_ctx)
2239 {
2240     g_string_printf(gdbserver_state.str_buf, "sstepbits;sstep");
2241 #ifndef CONFIG_USER_ONLY
2242     g_string_append(gdbserver_state.str_buf, ";PhyMemMode");
2243 #endif
2244     put_strbuf();
2245 }
2246 
2247 #ifndef CONFIG_USER_ONLY
2248 static void handle_query_qemu_phy_mem_mode(GArray *params,
2249                                            void *user_ctx)
2250 {
2251     g_string_printf(gdbserver_state.str_buf, "%d", phy_memory_mode);
2252     put_strbuf();
2253 }
2254 
2255 static void handle_set_qemu_phy_mem_mode(GArray *params, void *user_ctx)
2256 {
2257     if (!params->len) {
2258         put_packet("E22");
2259         return;
2260     }
2261 
2262     if (!get_param(params, 0)->val_ul) {
2263         phy_memory_mode = 0;
2264     } else {
2265         phy_memory_mode = 1;
2266     }
2267     put_packet("OK");
2268 }
2269 #endif
2270 
2271 static const GdbCmdParseEntry gdb_gen_query_set_common_table[] = {
2272     /* Order is important if has same prefix */
2273     {
2274         .handler = handle_query_qemu_sstepbits,
2275         .cmd = "qemu.sstepbits",
2276     },
2277     {
2278         .handler = handle_query_qemu_sstep,
2279         .cmd = "qemu.sstep",
2280     },
2281     {
2282         .handler = handle_set_qemu_sstep,
2283         .cmd = "qemu.sstep=",
2284         .cmd_startswith = 1,
2285         .schema = "l0"
2286     },
2287 };
2288 
2289 static const GdbCmdParseEntry gdb_gen_query_table[] = {
2290     {
2291         .handler = handle_query_curr_tid,
2292         .cmd = "C",
2293     },
2294     {
2295         .handler = handle_query_threads,
2296         .cmd = "sThreadInfo",
2297     },
2298     {
2299         .handler = handle_query_first_threads,
2300         .cmd = "fThreadInfo",
2301     },
2302     {
2303         .handler = handle_query_thread_extra,
2304         .cmd = "ThreadExtraInfo,",
2305         .cmd_startswith = 1,
2306         .schema = "t0"
2307     },
2308 #ifdef CONFIG_USER_ONLY
2309     {
2310         .handler = handle_query_offsets,
2311         .cmd = "Offsets",
2312     },
2313 #else
2314     {
2315         .handler = handle_query_rcmd,
2316         .cmd = "Rcmd,",
2317         .cmd_startswith = 1,
2318         .schema = "s0"
2319     },
2320 #endif
2321     {
2322         .handler = handle_query_supported,
2323         .cmd = "Supported:",
2324         .cmd_startswith = 1,
2325         .schema = "s0"
2326     },
2327     {
2328         .handler = handle_query_supported,
2329         .cmd = "Supported",
2330         .schema = "s0"
2331     },
2332     {
2333         .handler = handle_query_xfer_features,
2334         .cmd = "Xfer:features:read:",
2335         .cmd_startswith = 1,
2336         .schema = "s:l,l0"
2337     },
2338 #if defined(CONFIG_USER_ONLY) && defined(CONFIG_LINUX_USER)
2339     {
2340         .handler = handle_query_xfer_auxv,
2341         .cmd = "Xfer:auxv:read::",
2342         .cmd_startswith = 1,
2343         .schema = "l,l0"
2344     },
2345 #endif
2346     {
2347         .handler = handle_query_attached,
2348         .cmd = "Attached:",
2349         .cmd_startswith = 1
2350     },
2351     {
2352         .handler = handle_query_attached,
2353         .cmd = "Attached",
2354     },
2355     {
2356         .handler = handle_query_qemu_supported,
2357         .cmd = "qemu.Supported",
2358     },
2359 #ifndef CONFIG_USER_ONLY
2360     {
2361         .handler = handle_query_qemu_phy_mem_mode,
2362         .cmd = "qemu.PhyMemMode",
2363     },
2364 #endif
2365 };
2366 
2367 static const GdbCmdParseEntry gdb_gen_set_table[] = {
2368     /* Order is important if has same prefix */
2369     {
2370         .handler = handle_set_qemu_sstep,
2371         .cmd = "qemu.sstep:",
2372         .cmd_startswith = 1,
2373         .schema = "l0"
2374     },
2375 #ifndef CONFIG_USER_ONLY
2376     {
2377         .handler = handle_set_qemu_phy_mem_mode,
2378         .cmd = "qemu.PhyMemMode:",
2379         .cmd_startswith = 1,
2380         .schema = "l0"
2381     },
2382 #endif
2383 };
2384 
2385 static void handle_gen_query(GArray *params, void *user_ctx)
2386 {
2387     if (!params->len) {
2388         return;
2389     }
2390 
2391     if (!process_string_cmd(NULL, get_param(params, 0)->data,
2392                             gdb_gen_query_set_common_table,
2393                             ARRAY_SIZE(gdb_gen_query_set_common_table))) {
2394         return;
2395     }
2396 
2397     if (process_string_cmd(NULL, get_param(params, 0)->data,
2398                            gdb_gen_query_table,
2399                            ARRAY_SIZE(gdb_gen_query_table))) {
2400         put_packet("");
2401     }
2402 }
2403 
2404 static void handle_gen_set(GArray *params, void *user_ctx)
2405 {
2406     if (!params->len) {
2407         return;
2408     }
2409 
2410     if (!process_string_cmd(NULL, get_param(params, 0)->data,
2411                             gdb_gen_query_set_common_table,
2412                             ARRAY_SIZE(gdb_gen_query_set_common_table))) {
2413         return;
2414     }
2415 
2416     if (process_string_cmd(NULL, get_param(params, 0)->data,
2417                            gdb_gen_set_table,
2418                            ARRAY_SIZE(gdb_gen_set_table))) {
2419         put_packet("");
2420     }
2421 }
2422 
2423 static void handle_target_halt(GArray *params, void *user_ctx)
2424 {
2425     g_string_printf(gdbserver_state.str_buf, "T%02xthread:", GDB_SIGNAL_TRAP);
2426     gdb_append_thread_id(gdbserver_state.c_cpu, gdbserver_state.str_buf);
2427     g_string_append_c(gdbserver_state.str_buf, ';');
2428     put_strbuf();
2429     /*
2430      * Remove all the breakpoints when this query is issued,
2431      * because gdb is doing an initial connect and the state
2432      * should be cleaned up.
2433      */
2434     gdb_breakpoint_remove_all(gdbserver_state.c_cpu);
2435 }
2436 
2437 static int gdb_handle_packet(const char *line_buf)
2438 {
2439     const GdbCmdParseEntry *cmd_parser = NULL;
2440 
2441     trace_gdbstub_io_command(line_buf);
2442 
2443     switch (line_buf[0]) {
2444     case '!':
2445         put_packet("OK");
2446         break;
2447     case '?':
2448         {
2449             static const GdbCmdParseEntry target_halted_cmd_desc = {
2450                 .handler = handle_target_halt,
2451                 .cmd = "?",
2452                 .cmd_startswith = 1
2453             };
2454             cmd_parser = &target_halted_cmd_desc;
2455         }
2456         break;
2457     case 'c':
2458         {
2459             static const GdbCmdParseEntry continue_cmd_desc = {
2460                 .handler = handle_continue,
2461                 .cmd = "c",
2462                 .cmd_startswith = 1,
2463                 .schema = "L0"
2464             };
2465             cmd_parser = &continue_cmd_desc;
2466         }
2467         break;
2468     case 'C':
2469         {
2470             static const GdbCmdParseEntry cont_with_sig_cmd_desc = {
2471                 .handler = handle_cont_with_sig,
2472                 .cmd = "C",
2473                 .cmd_startswith = 1,
2474                 .schema = "l0"
2475             };
2476             cmd_parser = &cont_with_sig_cmd_desc;
2477         }
2478         break;
2479     case 'v':
2480         {
2481             static const GdbCmdParseEntry v_cmd_desc = {
2482                 .handler = handle_v_commands,
2483                 .cmd = "v",
2484                 .cmd_startswith = 1,
2485                 .schema = "s0"
2486             };
2487             cmd_parser = &v_cmd_desc;
2488         }
2489         break;
2490     case 'k':
2491         /* Kill the target */
2492         error_report("QEMU: Terminated via GDBstub");
2493         gdb_exit(0);
2494         exit(0);
2495     case 'D':
2496         {
2497             static const GdbCmdParseEntry detach_cmd_desc = {
2498                 .handler = handle_detach,
2499                 .cmd = "D",
2500                 .cmd_startswith = 1,
2501                 .schema = "?.l0"
2502             };
2503             cmd_parser = &detach_cmd_desc;
2504         }
2505         break;
2506     case 's':
2507         {
2508             static const GdbCmdParseEntry step_cmd_desc = {
2509                 .handler = handle_step,
2510                 .cmd = "s",
2511                 .cmd_startswith = 1,
2512                 .schema = "L0"
2513             };
2514             cmd_parser = &step_cmd_desc;
2515         }
2516         break;
2517     case 'b':
2518         {
2519             static const GdbCmdParseEntry backward_cmd_desc = {
2520                 .handler = handle_backward,
2521                 .cmd = "b",
2522                 .cmd_startswith = 1,
2523                 .schema = "o0"
2524             };
2525             cmd_parser = &backward_cmd_desc;
2526         }
2527         break;
2528     case 'F':
2529         {
2530             static const GdbCmdParseEntry file_io_cmd_desc = {
2531                 .handler = handle_file_io,
2532                 .cmd = "F",
2533                 .cmd_startswith = 1,
2534                 .schema = "L,L,o0"
2535             };
2536             cmd_parser = &file_io_cmd_desc;
2537         }
2538         break;
2539     case 'g':
2540         {
2541             static const GdbCmdParseEntry read_all_regs_cmd_desc = {
2542                 .handler = handle_read_all_regs,
2543                 .cmd = "g",
2544                 .cmd_startswith = 1
2545             };
2546             cmd_parser = &read_all_regs_cmd_desc;
2547         }
2548         break;
2549     case 'G':
2550         {
2551             static const GdbCmdParseEntry write_all_regs_cmd_desc = {
2552                 .handler = handle_write_all_regs,
2553                 .cmd = "G",
2554                 .cmd_startswith = 1,
2555                 .schema = "s0"
2556             };
2557             cmd_parser = &write_all_regs_cmd_desc;
2558         }
2559         break;
2560     case 'm':
2561         {
2562             static const GdbCmdParseEntry read_mem_cmd_desc = {
2563                 .handler = handle_read_mem,
2564                 .cmd = "m",
2565                 .cmd_startswith = 1,
2566                 .schema = "L,L0"
2567             };
2568             cmd_parser = &read_mem_cmd_desc;
2569         }
2570         break;
2571     case 'M':
2572         {
2573             static const GdbCmdParseEntry write_mem_cmd_desc = {
2574                 .handler = handle_write_mem,
2575                 .cmd = "M",
2576                 .cmd_startswith = 1,
2577                 .schema = "L,L:s0"
2578             };
2579             cmd_parser = &write_mem_cmd_desc;
2580         }
2581         break;
2582     case 'p':
2583         {
2584             static const GdbCmdParseEntry get_reg_cmd_desc = {
2585                 .handler = handle_get_reg,
2586                 .cmd = "p",
2587                 .cmd_startswith = 1,
2588                 .schema = "L0"
2589             };
2590             cmd_parser = &get_reg_cmd_desc;
2591         }
2592         break;
2593     case 'P':
2594         {
2595             static const GdbCmdParseEntry set_reg_cmd_desc = {
2596                 .handler = handle_set_reg,
2597                 .cmd = "P",
2598                 .cmd_startswith = 1,
2599                 .schema = "L?s0"
2600             };
2601             cmd_parser = &set_reg_cmd_desc;
2602         }
2603         break;
2604     case 'Z':
2605         {
2606             static const GdbCmdParseEntry insert_bp_cmd_desc = {
2607                 .handler = handle_insert_bp,
2608                 .cmd = "Z",
2609                 .cmd_startswith = 1,
2610                 .schema = "l?L?L0"
2611             };
2612             cmd_parser = &insert_bp_cmd_desc;
2613         }
2614         break;
2615     case 'z':
2616         {
2617             static const GdbCmdParseEntry remove_bp_cmd_desc = {
2618                 .handler = handle_remove_bp,
2619                 .cmd = "z",
2620                 .cmd_startswith = 1,
2621                 .schema = "l?L?L0"
2622             };
2623             cmd_parser = &remove_bp_cmd_desc;
2624         }
2625         break;
2626     case 'H':
2627         {
2628             static const GdbCmdParseEntry set_thread_cmd_desc = {
2629                 .handler = handle_set_thread,
2630                 .cmd = "H",
2631                 .cmd_startswith = 1,
2632                 .schema = "o.t0"
2633             };
2634             cmd_parser = &set_thread_cmd_desc;
2635         }
2636         break;
2637     case 'T':
2638         {
2639             static const GdbCmdParseEntry thread_alive_cmd_desc = {
2640                 .handler = handle_thread_alive,
2641                 .cmd = "T",
2642                 .cmd_startswith = 1,
2643                 .schema = "t0"
2644             };
2645             cmd_parser = &thread_alive_cmd_desc;
2646         }
2647         break;
2648     case 'q':
2649         {
2650             static const GdbCmdParseEntry gen_query_cmd_desc = {
2651                 .handler = handle_gen_query,
2652                 .cmd = "q",
2653                 .cmd_startswith = 1,
2654                 .schema = "s0"
2655             };
2656             cmd_parser = &gen_query_cmd_desc;
2657         }
2658         break;
2659     case 'Q':
2660         {
2661             static const GdbCmdParseEntry gen_set_cmd_desc = {
2662                 .handler = handle_gen_set,
2663                 .cmd = "Q",
2664                 .cmd_startswith = 1,
2665                 .schema = "s0"
2666             };
2667             cmd_parser = &gen_set_cmd_desc;
2668         }
2669         break;
2670     default:
2671         /* put empty packet */
2672         put_packet("");
2673         break;
2674     }
2675 
2676     if (cmd_parser) {
2677         run_cmd_parser(line_buf, cmd_parser);
2678     }
2679 
2680     return RS_IDLE;
2681 }
2682 
2683 void gdb_set_stop_cpu(CPUState *cpu)
2684 {
2685     GDBProcess *p = gdb_get_cpu_process(cpu);
2686 
2687     if (!p->attached) {
2688         /*
2689          * Having a stop CPU corresponding to a process that is not attached
2690          * confuses GDB. So we ignore the request.
2691          */
2692         return;
2693     }
2694 
2695     gdbserver_state.c_cpu = cpu;
2696     gdbserver_state.g_cpu = cpu;
2697 }
2698 
2699 #ifndef CONFIG_USER_ONLY
2700 static void gdb_vm_state_change(void *opaque, bool running, RunState state)
2701 {
2702     CPUState *cpu = gdbserver_state.c_cpu;
2703     g_autoptr(GString) buf = g_string_new(NULL);
2704     g_autoptr(GString) tid = g_string_new(NULL);
2705     const char *type;
2706     int ret;
2707 
2708     if (running || gdbserver_state.state == RS_INACTIVE) {
2709         return;
2710     }
2711     /* Is there a GDB syscall waiting to be sent?  */
2712     if (gdbserver_state.current_syscall_cb) {
2713         put_packet(gdbserver_state.syscall_buf);
2714         return;
2715     }
2716 
2717     if (cpu == NULL) {
2718         /* No process attached */
2719         return;
2720     }
2721 
2722     gdb_append_thread_id(cpu, tid);
2723 
2724     switch (state) {
2725     case RUN_STATE_DEBUG:
2726         if (cpu->watchpoint_hit) {
2727             switch (cpu->watchpoint_hit->flags & BP_MEM_ACCESS) {
2728             case BP_MEM_READ:
2729                 type = "r";
2730                 break;
2731             case BP_MEM_ACCESS:
2732                 type = "a";
2733                 break;
2734             default:
2735                 type = "";
2736                 break;
2737             }
2738             trace_gdbstub_hit_watchpoint(type, cpu_gdb_index(cpu),
2739                     (target_ulong)cpu->watchpoint_hit->vaddr);
2740             g_string_printf(buf, "T%02xthread:%s;%swatch:" TARGET_FMT_lx ";",
2741                             GDB_SIGNAL_TRAP, tid->str, type,
2742                             (target_ulong)cpu->watchpoint_hit->vaddr);
2743             cpu->watchpoint_hit = NULL;
2744             goto send_packet;
2745         } else {
2746             trace_gdbstub_hit_break();
2747         }
2748         tb_flush(cpu);
2749         ret = GDB_SIGNAL_TRAP;
2750         break;
2751     case RUN_STATE_PAUSED:
2752         trace_gdbstub_hit_paused();
2753         ret = GDB_SIGNAL_INT;
2754         break;
2755     case RUN_STATE_SHUTDOWN:
2756         trace_gdbstub_hit_shutdown();
2757         ret = GDB_SIGNAL_QUIT;
2758         break;
2759     case RUN_STATE_IO_ERROR:
2760         trace_gdbstub_hit_io_error();
2761         ret = GDB_SIGNAL_IO;
2762         break;
2763     case RUN_STATE_WATCHDOG:
2764         trace_gdbstub_hit_watchdog();
2765         ret = GDB_SIGNAL_ALRM;
2766         break;
2767     case RUN_STATE_INTERNAL_ERROR:
2768         trace_gdbstub_hit_internal_error();
2769         ret = GDB_SIGNAL_ABRT;
2770         break;
2771     case RUN_STATE_SAVE_VM:
2772     case RUN_STATE_RESTORE_VM:
2773         return;
2774     case RUN_STATE_FINISH_MIGRATE:
2775         ret = GDB_SIGNAL_XCPU;
2776         break;
2777     default:
2778         trace_gdbstub_hit_unknown(state);
2779         ret = GDB_SIGNAL_UNKNOWN;
2780         break;
2781     }
2782     gdb_set_stop_cpu(cpu);
2783     g_string_printf(buf, "T%02xthread:%s;", ret, tid->str);
2784 
2785 send_packet:
2786     put_packet(buf->str);
2787 
2788     /* disable single step if it was enabled */
2789     cpu_single_step(cpu, 0);
2790 }
2791 #endif
2792 
2793 /* Send a gdb syscall request.
2794    This accepts limited printf-style format specifiers, specifically:
2795     %x  - target_ulong argument printed in hex.
2796     %lx - 64-bit argument printed in hex.
2797     %s  - string pointer (target_ulong) and length (int) pair.  */
2798 void gdb_do_syscallv(gdb_syscall_complete_cb cb, const char *fmt, va_list va)
2799 {
2800     char *p;
2801     char *p_end;
2802     target_ulong addr;
2803     uint64_t i64;
2804 
2805     if (!gdb_attached()) {
2806         return;
2807     }
2808 
2809     gdbserver_state.current_syscall_cb = cb;
2810 #ifndef CONFIG_USER_ONLY
2811     vm_stop(RUN_STATE_DEBUG);
2812 #endif
2813     p = &gdbserver_state.syscall_buf[0];
2814     p_end = &gdbserver_state.syscall_buf[sizeof(gdbserver_state.syscall_buf)];
2815     *(p++) = 'F';
2816     while (*fmt) {
2817         if (*fmt == '%') {
2818             fmt++;
2819             switch (*fmt++) {
2820             case 'x':
2821                 addr = va_arg(va, target_ulong);
2822                 p += snprintf(p, p_end - p, TARGET_FMT_lx, addr);
2823                 break;
2824             case 'l':
2825                 if (*(fmt++) != 'x')
2826                     goto bad_format;
2827                 i64 = va_arg(va, uint64_t);
2828                 p += snprintf(p, p_end - p, "%" PRIx64, i64);
2829                 break;
2830             case 's':
2831                 addr = va_arg(va, target_ulong);
2832                 p += snprintf(p, p_end - p, TARGET_FMT_lx "/%x",
2833                               addr, va_arg(va, int));
2834                 break;
2835             default:
2836             bad_format:
2837                 error_report("gdbstub: Bad syscall format string '%s'",
2838                              fmt - 1);
2839                 break;
2840             }
2841         } else {
2842             *(p++) = *(fmt++);
2843         }
2844     }
2845     *p = 0;
2846 #ifdef CONFIG_USER_ONLY
2847     put_packet(gdbserver_state.syscall_buf);
2848     /* Return control to gdb for it to process the syscall request.
2849      * Since the protocol requires that gdb hands control back to us
2850      * using a "here are the results" F packet, we don't need to check
2851      * gdb_handlesig's return value (which is the signal to deliver if
2852      * execution was resumed via a continue packet).
2853      */
2854     gdb_handlesig(gdbserver_state.c_cpu, 0);
2855 #else
2856     /* In this case wait to send the syscall packet until notification that
2857        the CPU has stopped.  This must be done because if the packet is sent
2858        now the reply from the syscall request could be received while the CPU
2859        is still in the running state, which can cause packets to be dropped
2860        and state transition 'T' packets to be sent while the syscall is still
2861        being processed.  */
2862     qemu_cpu_kick(gdbserver_state.c_cpu);
2863 #endif
2864 }
2865 
2866 void gdb_do_syscall(gdb_syscall_complete_cb cb, const char *fmt, ...)
2867 {
2868     va_list va;
2869 
2870     va_start(va, fmt);
2871     gdb_do_syscallv(cb, fmt, va);
2872     va_end(va);
2873 }
2874 
2875 static void gdb_read_byte(uint8_t ch)
2876 {
2877     uint8_t reply;
2878 
2879 #ifndef CONFIG_USER_ONLY
2880     if (gdbserver_state.last_packet->len) {
2881         /* Waiting for a response to the last packet.  If we see the start
2882            of a new command then abandon the previous response.  */
2883         if (ch == '-') {
2884             trace_gdbstub_err_got_nack();
2885             put_buffer(gdbserver_state.last_packet->data,
2886                        gdbserver_state.last_packet->len);
2887         } else if (ch == '+') {
2888             trace_gdbstub_io_got_ack();
2889         } else {
2890             trace_gdbstub_io_got_unexpected(ch);
2891         }
2892 
2893         if (ch == '+' || ch == '$') {
2894             g_byte_array_set_size(gdbserver_state.last_packet, 0);
2895         }
2896         if (ch != '$')
2897             return;
2898     }
2899     if (runstate_is_running()) {
2900         /* when the CPU is running, we cannot do anything except stop
2901            it when receiving a char */
2902         vm_stop(RUN_STATE_PAUSED);
2903     } else
2904 #endif
2905     {
2906         switch(gdbserver_state.state) {
2907         case RS_IDLE:
2908             if (ch == '$') {
2909                 /* start of command packet */
2910                 gdbserver_state.line_buf_index = 0;
2911                 gdbserver_state.line_sum = 0;
2912                 gdbserver_state.state = RS_GETLINE;
2913             } else {
2914                 trace_gdbstub_err_garbage(ch);
2915             }
2916             break;
2917         case RS_GETLINE:
2918             if (ch == '}') {
2919                 /* start escape sequence */
2920                 gdbserver_state.state = RS_GETLINE_ESC;
2921                 gdbserver_state.line_sum += ch;
2922             } else if (ch == '*') {
2923                 /* start run length encoding sequence */
2924                 gdbserver_state.state = RS_GETLINE_RLE;
2925                 gdbserver_state.line_sum += ch;
2926             } else if (ch == '#') {
2927                 /* end of command, start of checksum*/
2928                 gdbserver_state.state = RS_CHKSUM1;
2929             } else if (gdbserver_state.line_buf_index >= sizeof(gdbserver_state.line_buf) - 1) {
2930                 trace_gdbstub_err_overrun();
2931                 gdbserver_state.state = RS_IDLE;
2932             } else {
2933                 /* unescaped command character */
2934                 gdbserver_state.line_buf[gdbserver_state.line_buf_index++] = ch;
2935                 gdbserver_state.line_sum += ch;
2936             }
2937             break;
2938         case RS_GETLINE_ESC:
2939             if (ch == '#') {
2940                 /* unexpected end of command in escape sequence */
2941                 gdbserver_state.state = RS_CHKSUM1;
2942             } else if (gdbserver_state.line_buf_index >= sizeof(gdbserver_state.line_buf) - 1) {
2943                 /* command buffer overrun */
2944                 trace_gdbstub_err_overrun();
2945                 gdbserver_state.state = RS_IDLE;
2946             } else {
2947                 /* parse escaped character and leave escape state */
2948                 gdbserver_state.line_buf[gdbserver_state.line_buf_index++] = ch ^ 0x20;
2949                 gdbserver_state.line_sum += ch;
2950                 gdbserver_state.state = RS_GETLINE;
2951             }
2952             break;
2953         case RS_GETLINE_RLE:
2954             /*
2955              * Run-length encoding is explained in "Debugging with GDB /
2956              * Appendix E GDB Remote Serial Protocol / Overview".
2957              */
2958             if (ch < ' ' || ch == '#' || ch == '$' || ch > 126) {
2959                 /* invalid RLE count encoding */
2960                 trace_gdbstub_err_invalid_repeat(ch);
2961                 gdbserver_state.state = RS_GETLINE;
2962             } else {
2963                 /* decode repeat length */
2964                 int repeat = ch - ' ' + 3;
2965                 if (gdbserver_state.line_buf_index + repeat >= sizeof(gdbserver_state.line_buf) - 1) {
2966                     /* that many repeats would overrun the command buffer */
2967                     trace_gdbstub_err_overrun();
2968                     gdbserver_state.state = RS_IDLE;
2969                 } else if (gdbserver_state.line_buf_index < 1) {
2970                     /* got a repeat but we have nothing to repeat */
2971                     trace_gdbstub_err_invalid_rle();
2972                     gdbserver_state.state = RS_GETLINE;
2973                 } else {
2974                     /* repeat the last character */
2975                     memset(gdbserver_state.line_buf + gdbserver_state.line_buf_index,
2976                            gdbserver_state.line_buf[gdbserver_state.line_buf_index - 1], repeat);
2977                     gdbserver_state.line_buf_index += repeat;
2978                     gdbserver_state.line_sum += ch;
2979                     gdbserver_state.state = RS_GETLINE;
2980                 }
2981             }
2982             break;
2983         case RS_CHKSUM1:
2984             /* get high hex digit of checksum */
2985             if (!isxdigit(ch)) {
2986                 trace_gdbstub_err_checksum_invalid(ch);
2987                 gdbserver_state.state = RS_GETLINE;
2988                 break;
2989             }
2990             gdbserver_state.line_buf[gdbserver_state.line_buf_index] = '\0';
2991             gdbserver_state.line_csum = fromhex(ch) << 4;
2992             gdbserver_state.state = RS_CHKSUM2;
2993             break;
2994         case RS_CHKSUM2:
2995             /* get low hex digit of checksum */
2996             if (!isxdigit(ch)) {
2997                 trace_gdbstub_err_checksum_invalid(ch);
2998                 gdbserver_state.state = RS_GETLINE;
2999                 break;
3000             }
3001             gdbserver_state.line_csum |= fromhex(ch);
3002 
3003             if (gdbserver_state.line_csum != (gdbserver_state.line_sum & 0xff)) {
3004                 trace_gdbstub_err_checksum_incorrect(gdbserver_state.line_sum, gdbserver_state.line_csum);
3005                 /* send NAK reply */
3006                 reply = '-';
3007                 put_buffer(&reply, 1);
3008                 gdbserver_state.state = RS_IDLE;
3009             } else {
3010                 /* send ACK reply */
3011                 reply = '+';
3012                 put_buffer(&reply, 1);
3013                 gdbserver_state.state = gdb_handle_packet(gdbserver_state.line_buf);
3014             }
3015             break;
3016         default:
3017             abort();
3018         }
3019     }
3020 }
3021 
3022 /* Tell the remote gdb that the process has exited.  */
3023 void gdb_exit(int code)
3024 {
3025   char buf[4];
3026 
3027   if (!gdbserver_state.init) {
3028       return;
3029   }
3030 #ifdef CONFIG_USER_ONLY
3031   if (gdbserver_state.socket_path) {
3032       unlink(gdbserver_state.socket_path);
3033   }
3034   if (gdbserver_state.fd < 0) {
3035       return;
3036   }
3037 #endif
3038 
3039   trace_gdbstub_op_exiting((uint8_t)code);
3040 
3041   snprintf(buf, sizeof(buf), "W%02x", (uint8_t)code);
3042   put_packet(buf);
3043 
3044 #ifndef CONFIG_USER_ONLY
3045   qemu_chr_fe_deinit(&gdbserver_state.chr, true);
3046 #endif
3047 }
3048 
3049 /*
3050  * Create the process that will contain all the "orphan" CPUs (that are not
3051  * part of a CPU cluster). Note that if this process contains no CPUs, it won't
3052  * be attachable and thus will be invisible to the user.
3053  */
3054 static void create_default_process(GDBState *s)
3055 {
3056     GDBProcess *process;
3057     int max_pid = 0;
3058 
3059     if (gdbserver_state.process_num) {
3060         max_pid = s->processes[s->process_num - 1].pid;
3061     }
3062 
3063     s->processes = g_renew(GDBProcess, s->processes, ++s->process_num);
3064     process = &s->processes[s->process_num - 1];
3065 
3066     /* We need an available PID slot for this process */
3067     assert(max_pid < UINT32_MAX);
3068 
3069     process->pid = max_pid + 1;
3070     process->attached = false;
3071     process->target_xml[0] = '\0';
3072 }
3073 
3074 #ifdef CONFIG_USER_ONLY
3075 int
3076 gdb_handlesig(CPUState *cpu, int sig)
3077 {
3078     char buf[256];
3079     int n;
3080 
3081     if (!gdbserver_state.init || gdbserver_state.fd < 0) {
3082         return sig;
3083     }
3084 
3085     /* disable single step if it was enabled */
3086     cpu_single_step(cpu, 0);
3087     tb_flush(cpu);
3088 
3089     if (sig != 0) {
3090         gdb_set_stop_cpu(cpu);
3091         g_string_printf(gdbserver_state.str_buf,
3092                         "T%02xthread:", target_signal_to_gdb(sig));
3093         gdb_append_thread_id(cpu, gdbserver_state.str_buf);
3094         g_string_append_c(gdbserver_state.str_buf, ';');
3095         put_strbuf();
3096     }
3097     /* put_packet() might have detected that the peer terminated the
3098        connection.  */
3099     if (gdbserver_state.fd < 0) {
3100         return sig;
3101     }
3102 
3103     sig = 0;
3104     gdbserver_state.state = RS_IDLE;
3105     gdbserver_state.running_state = 0;
3106     while (gdbserver_state.running_state == 0) {
3107         n = read(gdbserver_state.fd, buf, 256);
3108         if (n > 0) {
3109             int i;
3110 
3111             for (i = 0; i < n; i++) {
3112                 gdb_read_byte(buf[i]);
3113             }
3114         } else {
3115             /* XXX: Connection closed.  Should probably wait for another
3116                connection before continuing.  */
3117             if (n == 0) {
3118                 close(gdbserver_state.fd);
3119             }
3120             gdbserver_state.fd = -1;
3121             return sig;
3122         }
3123     }
3124     sig = gdbserver_state.signal;
3125     gdbserver_state.signal = 0;
3126     return sig;
3127 }
3128 
3129 /* Tell the remote gdb that the process has exited due to SIG.  */
3130 void gdb_signalled(CPUArchState *env, int sig)
3131 {
3132     char buf[4];
3133 
3134     if (!gdbserver_state.init || gdbserver_state.fd < 0) {
3135         return;
3136     }
3137 
3138     snprintf(buf, sizeof(buf), "X%02x", target_signal_to_gdb(sig));
3139     put_packet(buf);
3140 }
3141 
3142 static void gdb_accept_init(int fd)
3143 {
3144     init_gdbserver_state();
3145     create_default_process(&gdbserver_state);
3146     gdbserver_state.processes[0].attached = true;
3147     gdbserver_state.c_cpu = gdb_first_attached_cpu();
3148     gdbserver_state.g_cpu = gdbserver_state.c_cpu;
3149     gdbserver_state.fd = fd;
3150     gdb_has_xml = false;
3151 }
3152 
3153 static bool gdb_accept_socket(int gdb_fd)
3154 {
3155     int fd;
3156 
3157     for(;;) {
3158         fd = accept(gdb_fd, NULL, NULL);
3159         if (fd < 0 && errno != EINTR) {
3160             perror("accept socket");
3161             return false;
3162         } else if (fd >= 0) {
3163             qemu_set_cloexec(fd);
3164             break;
3165         }
3166     }
3167 
3168     gdb_accept_init(fd);
3169     return true;
3170 }
3171 
3172 static int gdbserver_open_socket(const char *path)
3173 {
3174     struct sockaddr_un sockaddr = {};
3175     int fd, ret;
3176 
3177     fd = socket(AF_UNIX, SOCK_STREAM, 0);
3178     if (fd < 0) {
3179         perror("create socket");
3180         return -1;
3181     }
3182 
3183     sockaddr.sun_family = AF_UNIX;
3184     pstrcpy(sockaddr.sun_path, sizeof(sockaddr.sun_path) - 1, path);
3185     ret = bind(fd, (struct sockaddr *)&sockaddr, sizeof(sockaddr));
3186     if (ret < 0) {
3187         perror("bind socket");
3188         close(fd);
3189         return -1;
3190     }
3191     ret = listen(fd, 1);
3192     if (ret < 0) {
3193         perror("listen socket");
3194         close(fd);
3195         return -1;
3196     }
3197 
3198     return fd;
3199 }
3200 
3201 static bool gdb_accept_tcp(int gdb_fd)
3202 {
3203     struct sockaddr_in sockaddr = {};
3204     socklen_t len;
3205     int fd;
3206 
3207     for(;;) {
3208         len = sizeof(sockaddr);
3209         fd = accept(gdb_fd, (struct sockaddr *)&sockaddr, &len);
3210         if (fd < 0 && errno != EINTR) {
3211             perror("accept");
3212             return false;
3213         } else if (fd >= 0) {
3214             qemu_set_cloexec(fd);
3215             break;
3216         }
3217     }
3218 
3219     /* set short latency */
3220     if (socket_set_nodelay(fd)) {
3221         perror("setsockopt");
3222         close(fd);
3223         return false;
3224     }
3225 
3226     gdb_accept_init(fd);
3227     return true;
3228 }
3229 
3230 static int gdbserver_open_port(int port)
3231 {
3232     struct sockaddr_in sockaddr;
3233     int fd, ret;
3234 
3235     fd = socket(PF_INET, SOCK_STREAM, 0);
3236     if (fd < 0) {
3237         perror("socket");
3238         return -1;
3239     }
3240     qemu_set_cloexec(fd);
3241 
3242     socket_set_fast_reuse(fd);
3243 
3244     sockaddr.sin_family = AF_INET;
3245     sockaddr.sin_port = htons(port);
3246     sockaddr.sin_addr.s_addr = 0;
3247     ret = bind(fd, (struct sockaddr *)&sockaddr, sizeof(sockaddr));
3248     if (ret < 0) {
3249         perror("bind");
3250         close(fd);
3251         return -1;
3252     }
3253     ret = listen(fd, 1);
3254     if (ret < 0) {
3255         perror("listen");
3256         close(fd);
3257         return -1;
3258     }
3259 
3260     return fd;
3261 }
3262 
3263 int gdbserver_start(const char *port_or_path)
3264 {
3265     int port = g_ascii_strtoull(port_or_path, NULL, 10);
3266     int gdb_fd;
3267 
3268     if (port > 0) {
3269         gdb_fd = gdbserver_open_port(port);
3270     } else {
3271         gdb_fd = gdbserver_open_socket(port_or_path);
3272     }
3273 
3274     if (gdb_fd < 0) {
3275         return -1;
3276     }
3277 
3278     if (port > 0 && gdb_accept_tcp(gdb_fd)) {
3279         return 0;
3280     } else if (gdb_accept_socket(gdb_fd)) {
3281         gdbserver_state.socket_path = g_strdup(port_or_path);
3282         return 0;
3283     }
3284 
3285     /* gone wrong */
3286     close(gdb_fd);
3287     return -1;
3288 }
3289 
3290 /* Disable gdb stub for child processes.  */
3291 void gdbserver_fork(CPUState *cpu)
3292 {
3293     if (!gdbserver_state.init || gdbserver_state.fd < 0) {
3294         return;
3295     }
3296     close(gdbserver_state.fd);
3297     gdbserver_state.fd = -1;
3298     cpu_breakpoint_remove_all(cpu, BP_GDB);
3299     cpu_watchpoint_remove_all(cpu, BP_GDB);
3300 }
3301 #else
3302 static int gdb_chr_can_receive(void *opaque)
3303 {
3304   /* We can handle an arbitrarily large amount of data.
3305    Pick the maximum packet size, which is as good as anything.  */
3306   return MAX_PACKET_LENGTH;
3307 }
3308 
3309 static void gdb_chr_receive(void *opaque, const uint8_t *buf, int size)
3310 {
3311     int i;
3312 
3313     for (i = 0; i < size; i++) {
3314         gdb_read_byte(buf[i]);
3315     }
3316 }
3317 
3318 static void gdb_chr_event(void *opaque, QEMUChrEvent event)
3319 {
3320     int i;
3321     GDBState *s = (GDBState *) opaque;
3322 
3323     switch (event) {
3324     case CHR_EVENT_OPENED:
3325         /* Start with first process attached, others detached */
3326         for (i = 0; i < s->process_num; i++) {
3327             s->processes[i].attached = !i;
3328         }
3329 
3330         s->c_cpu = gdb_first_attached_cpu();
3331         s->g_cpu = s->c_cpu;
3332 
3333         vm_stop(RUN_STATE_PAUSED);
3334         replay_gdb_attached();
3335         gdb_has_xml = false;
3336         break;
3337     default:
3338         break;
3339     }
3340 }
3341 
3342 static int gdb_monitor_write(Chardev *chr, const uint8_t *buf, int len)
3343 {
3344     g_autoptr(GString) hex_buf = g_string_new("O");
3345     memtohex(hex_buf, buf, len);
3346     put_packet(hex_buf->str);
3347     return len;
3348 }
3349 
3350 #ifndef _WIN32
3351 static void gdb_sigterm_handler(int signal)
3352 {
3353     if (runstate_is_running()) {
3354         vm_stop(RUN_STATE_PAUSED);
3355     }
3356 }
3357 #endif
3358 
3359 static void gdb_monitor_open(Chardev *chr, ChardevBackend *backend,
3360                              bool *be_opened, Error **errp)
3361 {
3362     *be_opened = false;
3363 }
3364 
3365 static void char_gdb_class_init(ObjectClass *oc, void *data)
3366 {
3367     ChardevClass *cc = CHARDEV_CLASS(oc);
3368 
3369     cc->internal = true;
3370     cc->open = gdb_monitor_open;
3371     cc->chr_write = gdb_monitor_write;
3372 }
3373 
3374 #define TYPE_CHARDEV_GDB "chardev-gdb"
3375 
3376 static const TypeInfo char_gdb_type_info = {
3377     .name = TYPE_CHARDEV_GDB,
3378     .parent = TYPE_CHARDEV,
3379     .class_init = char_gdb_class_init,
3380 };
3381 
3382 static int find_cpu_clusters(Object *child, void *opaque)
3383 {
3384     if (object_dynamic_cast(child, TYPE_CPU_CLUSTER)) {
3385         GDBState *s = (GDBState *) opaque;
3386         CPUClusterState *cluster = CPU_CLUSTER(child);
3387         GDBProcess *process;
3388 
3389         s->processes = g_renew(GDBProcess, s->processes, ++s->process_num);
3390 
3391         process = &s->processes[s->process_num - 1];
3392 
3393         /*
3394          * GDB process IDs -1 and 0 are reserved. To avoid subtle errors at
3395          * runtime, we enforce here that the machine does not use a cluster ID
3396          * that would lead to PID 0.
3397          */
3398         assert(cluster->cluster_id != UINT32_MAX);
3399         process->pid = cluster->cluster_id + 1;
3400         process->attached = false;
3401         process->target_xml[0] = '\0';
3402 
3403         return 0;
3404     }
3405 
3406     return object_child_foreach(child, find_cpu_clusters, opaque);
3407 }
3408 
3409 static int pid_order(const void *a, const void *b)
3410 {
3411     GDBProcess *pa = (GDBProcess *) a;
3412     GDBProcess *pb = (GDBProcess *) b;
3413 
3414     if (pa->pid < pb->pid) {
3415         return -1;
3416     } else if (pa->pid > pb->pid) {
3417         return 1;
3418     } else {
3419         return 0;
3420     }
3421 }
3422 
3423 static void create_processes(GDBState *s)
3424 {
3425     object_child_foreach(object_get_root(), find_cpu_clusters, s);
3426 
3427     if (gdbserver_state.processes) {
3428         /* Sort by PID */
3429         qsort(gdbserver_state.processes, gdbserver_state.process_num, sizeof(gdbserver_state.processes[0]), pid_order);
3430     }
3431 
3432     create_default_process(s);
3433 }
3434 
3435 int gdbserver_start(const char *device)
3436 {
3437     trace_gdbstub_op_start(device);
3438 
3439     char gdbstub_device_name[128];
3440     Chardev *chr = NULL;
3441     Chardev *mon_chr;
3442 
3443     if (!first_cpu) {
3444         error_report("gdbstub: meaningless to attach gdb to a "
3445                      "machine without any CPU.");
3446         return -1;
3447     }
3448 
3449     if (!gdb_supports_guest_debug()) {
3450         error_report("gdbstub: current accelerator doesn't support guest debugging");
3451         return -1;
3452     }
3453 
3454     if (!device)
3455         return -1;
3456     if (strcmp(device, "none") != 0) {
3457         if (strstart(device, "tcp:", NULL)) {
3458             /* enforce required TCP attributes */
3459             snprintf(gdbstub_device_name, sizeof(gdbstub_device_name),
3460                      "%s,wait=off,nodelay=on,server=on", device);
3461             device = gdbstub_device_name;
3462         }
3463 #ifndef _WIN32
3464         else if (strcmp(device, "stdio") == 0) {
3465             struct sigaction act;
3466 
3467             memset(&act, 0, sizeof(act));
3468             act.sa_handler = gdb_sigterm_handler;
3469             sigaction(SIGINT, &act, NULL);
3470         }
3471 #endif
3472         /*
3473          * FIXME: it's a bit weird to allow using a mux chardev here
3474          * and implicitly setup a monitor. We may want to break this.
3475          */
3476         chr = qemu_chr_new_noreplay("gdb", device, true, NULL);
3477         if (!chr)
3478             return -1;
3479     }
3480 
3481     if (!gdbserver_state.init) {
3482         init_gdbserver_state();
3483 
3484         qemu_add_vm_change_state_handler(gdb_vm_state_change, NULL);
3485 
3486         /* Initialize a monitor terminal for gdb */
3487         mon_chr = qemu_chardev_new(NULL, TYPE_CHARDEV_GDB,
3488                                    NULL, NULL, &error_abort);
3489         monitor_init_hmp(mon_chr, false, &error_abort);
3490     } else {
3491         qemu_chr_fe_deinit(&gdbserver_state.chr, true);
3492         mon_chr = gdbserver_state.mon_chr;
3493         reset_gdbserver_state();
3494     }
3495 
3496     create_processes(&gdbserver_state);
3497 
3498     if (chr) {
3499         qemu_chr_fe_init(&gdbserver_state.chr, chr, &error_abort);
3500         qemu_chr_fe_set_handlers(&gdbserver_state.chr, gdb_chr_can_receive,
3501                                  gdb_chr_receive, gdb_chr_event,
3502                                  NULL, &gdbserver_state, NULL, true);
3503     }
3504     gdbserver_state.state = chr ? RS_IDLE : RS_INACTIVE;
3505     gdbserver_state.mon_chr = mon_chr;
3506     gdbserver_state.current_syscall_cb = NULL;
3507 
3508     return 0;
3509 }
3510 
3511 static void register_types(void)
3512 {
3513     type_register_static(&char_gdb_type_info);
3514 }
3515 
3516 type_init(register_types);
3517 #endif
3518