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Commit | Line | Data |
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ae7467b1 AB |
1 | /* |
2 | * gdbstub user-mode helper routines. | |
3 | * | |
4 | * We know for user-mode we are using TCG so we can call stuff directly. | |
5 | * | |
9455762f | 6 | * Copyright (c) 2003-2005 Fabrice Bellard |
ae7467b1 AB |
7 | * Copyright (c) 2022 Linaro Ltd |
8 | * | |
9455762f | 9 | * SPDX-License-Identifier: LGPL-2.0+ |
ae7467b1 AB |
10 | */ |
11 | ||
12 | #include "qemu/osdep.h" | |
d96bf49b AB |
13 | #include "qemu/cutils.h" |
14 | #include "qemu/sockets.h" | |
15 | #include "exec/hwaddr.h" | |
16 | #include "exec/tb-flush.h" | |
ae7467b1 | 17 | #include "exec/gdbstub.h" |
c566080c | 18 | #include "gdbstub/syscalls.h" |
d96bf49b | 19 | #include "gdbstub/user.h" |
ae7467b1 | 20 | #include "hw/core/cpu.h" |
d96bf49b | 21 | #include "trace.h" |
ae7467b1 AB |
22 | #include "internals.h" |
23 | ||
d96bf49b AB |
24 | /* User-mode specific state */ |
25 | typedef struct { | |
26 | int fd; | |
27 | char *socket_path; | |
28 | int running_state; | |
29 | } GDBUserState; | |
30 | ||
31 | static GDBUserState gdbserver_user_state; | |
32 | ||
33 | int gdb_get_char(void) | |
34 | { | |
35 | uint8_t ch; | |
36 | int ret; | |
37 | ||
38 | for (;;) { | |
39 | ret = recv(gdbserver_user_state.fd, &ch, 1, 0); | |
40 | if (ret < 0) { | |
41 | if (errno == ECONNRESET) { | |
42 | gdbserver_user_state.fd = -1; | |
43 | } | |
44 | if (errno != EINTR) { | |
45 | return -1; | |
46 | } | |
47 | } else if (ret == 0) { | |
48 | close(gdbserver_user_state.fd); | |
49 | gdbserver_user_state.fd = -1; | |
50 | return -1; | |
51 | } else { | |
52 | break; | |
53 | } | |
54 | } | |
55 | return ch; | |
56 | } | |
57 | ||
a7e0f9bd AB |
58 | bool gdb_got_immediate_ack(void) |
59 | { | |
60 | int i; | |
61 | ||
62 | i = gdb_get_char(); | |
63 | if (i < 0) { | |
64 | /* no response, continue anyway */ | |
65 | return true; | |
66 | } | |
67 | ||
68 | if (i == '+') { | |
69 | /* received correctly, continue */ | |
70 | return true; | |
71 | } | |
72 | ||
73 | /* anything else, including '-' then try again */ | |
74 | return false; | |
75 | } | |
76 | ||
d96bf49b AB |
77 | void gdb_put_buffer(const uint8_t *buf, int len) |
78 | { | |
79 | int ret; | |
80 | ||
81 | while (len > 0) { | |
82 | ret = send(gdbserver_user_state.fd, buf, len, 0); | |
83 | if (ret < 0) { | |
84 | if (errno != EINTR) { | |
85 | return; | |
86 | } | |
87 | } else { | |
88 | buf += ret; | |
89 | len -= ret; | |
90 | } | |
91 | } | |
92 | } | |
93 | ||
94 | /* Tell the remote gdb that the process has exited. */ | |
95 | void gdb_exit(int code) | |
96 | { | |
97 | char buf[4]; | |
98 | ||
99 | if (!gdbserver_state.init) { | |
100 | return; | |
101 | } | |
102 | if (gdbserver_user_state.socket_path) { | |
103 | unlink(gdbserver_user_state.socket_path); | |
104 | } | |
105 | if (gdbserver_user_state.fd < 0) { | |
106 | return; | |
107 | } | |
108 | ||
109 | trace_gdbstub_op_exiting((uint8_t)code); | |
110 | ||
75837005 MTB |
111 | if (gdbserver_state.allow_stop_reply) { |
112 | snprintf(buf, sizeof(buf), "W%02x", (uint8_t)code); | |
113 | gdb_put_packet(buf); | |
114 | gdbserver_state.allow_stop_reply = false; | |
115 | } | |
d96bf49b AB |
116 | } |
117 | ||
118 | int gdb_handlesig(CPUState *cpu, int sig) | |
119 | { | |
120 | char buf[256]; | |
121 | int n; | |
122 | ||
123 | if (!gdbserver_state.init || gdbserver_user_state.fd < 0) { | |
124 | return sig; | |
125 | } | |
126 | ||
127 | /* disable single step if it was enabled */ | |
128 | cpu_single_step(cpu, 0); | |
129 | tb_flush(cpu); | |
130 | ||
131 | if (sig != 0) { | |
132 | gdb_set_stop_cpu(cpu); | |
75837005 MTB |
133 | if (gdbserver_state.allow_stop_reply) { |
134 | g_string_printf(gdbserver_state.str_buf, | |
135 | "T%02xthread:", gdb_target_signal_to_gdb(sig)); | |
136 | gdb_append_thread_id(cpu, gdbserver_state.str_buf); | |
137 | g_string_append_c(gdbserver_state.str_buf, ';'); | |
138 | gdb_put_strbuf(); | |
139 | gdbserver_state.allow_stop_reply = false; | |
140 | } | |
d96bf49b AB |
141 | } |
142 | /* | |
143 | * gdb_put_packet() might have detected that the peer terminated the | |
144 | * connection. | |
145 | */ | |
146 | if (gdbserver_user_state.fd < 0) { | |
147 | return sig; | |
148 | } | |
149 | ||
150 | sig = 0; | |
151 | gdbserver_state.state = RS_IDLE; | |
152 | gdbserver_user_state.running_state = 0; | |
153 | while (gdbserver_user_state.running_state == 0) { | |
154 | n = read(gdbserver_user_state.fd, buf, 256); | |
155 | if (n > 0) { | |
156 | int i; | |
157 | ||
158 | for (i = 0; i < n; i++) { | |
159 | gdb_read_byte(buf[i]); | |
160 | } | |
161 | } else { | |
162 | /* | |
163 | * XXX: Connection closed. Should probably wait for another | |
164 | * connection before continuing. | |
165 | */ | |
166 | if (n == 0) { | |
167 | close(gdbserver_user_state.fd); | |
168 | } | |
169 | gdbserver_user_state.fd = -1; | |
170 | return sig; | |
171 | } | |
172 | } | |
173 | sig = gdbserver_state.signal; | |
174 | gdbserver_state.signal = 0; | |
175 | return sig; | |
176 | } | |
177 | ||
178 | /* Tell the remote gdb that the process has exited due to SIG. */ | |
179 | void gdb_signalled(CPUArchState *env, int sig) | |
180 | { | |
181 | char buf[4]; | |
182 | ||
75837005 MTB |
183 | if (!gdbserver_state.init || gdbserver_user_state.fd < 0 || |
184 | !gdbserver_state.allow_stop_reply) { | |
d96bf49b AB |
185 | return; |
186 | } | |
187 | ||
188 | snprintf(buf, sizeof(buf), "X%02x", gdb_target_signal_to_gdb(sig)); | |
189 | gdb_put_packet(buf); | |
75837005 | 190 | gdbserver_state.allow_stop_reply = false; |
d96bf49b AB |
191 | } |
192 | ||
193 | static void gdb_accept_init(int fd) | |
194 | { | |
195 | gdb_init_gdbserver_state(); | |
196 | gdb_create_default_process(&gdbserver_state); | |
197 | gdbserver_state.processes[0].attached = true; | |
198 | gdbserver_state.c_cpu = gdb_first_attached_cpu(); | |
199 | gdbserver_state.g_cpu = gdbserver_state.c_cpu; | |
200 | gdbserver_user_state.fd = fd; | |
d96bf49b AB |
201 | } |
202 | ||
203 | static bool gdb_accept_socket(int gdb_fd) | |
204 | { | |
205 | int fd; | |
206 | ||
207 | for (;;) { | |
208 | fd = accept(gdb_fd, NULL, NULL); | |
209 | if (fd < 0 && errno != EINTR) { | |
210 | perror("accept socket"); | |
211 | return false; | |
212 | } else if (fd >= 0) { | |
213 | qemu_set_cloexec(fd); | |
214 | break; | |
215 | } | |
216 | } | |
217 | ||
218 | gdb_accept_init(fd); | |
219 | return true; | |
220 | } | |
221 | ||
222 | static int gdbserver_open_socket(const char *path) | |
223 | { | |
224 | struct sockaddr_un sockaddr = {}; | |
225 | int fd, ret; | |
226 | ||
227 | fd = socket(AF_UNIX, SOCK_STREAM, 0); | |
228 | if (fd < 0) { | |
229 | perror("create socket"); | |
230 | return -1; | |
231 | } | |
232 | ||
233 | sockaddr.sun_family = AF_UNIX; | |
234 | pstrcpy(sockaddr.sun_path, sizeof(sockaddr.sun_path) - 1, path); | |
235 | ret = bind(fd, (struct sockaddr *)&sockaddr, sizeof(sockaddr)); | |
236 | if (ret < 0) { | |
237 | perror("bind socket"); | |
238 | close(fd); | |
239 | return -1; | |
240 | } | |
241 | ret = listen(fd, 1); | |
242 | if (ret < 0) { | |
243 | perror("listen socket"); | |
244 | close(fd); | |
245 | return -1; | |
246 | } | |
247 | ||
248 | return fd; | |
249 | } | |
250 | ||
251 | static bool gdb_accept_tcp(int gdb_fd) | |
252 | { | |
253 | struct sockaddr_in sockaddr = {}; | |
254 | socklen_t len; | |
255 | int fd; | |
256 | ||
257 | for (;;) { | |
258 | len = sizeof(sockaddr); | |
259 | fd = accept(gdb_fd, (struct sockaddr *)&sockaddr, &len); | |
260 | if (fd < 0 && errno != EINTR) { | |
261 | perror("accept"); | |
262 | return false; | |
263 | } else if (fd >= 0) { | |
264 | qemu_set_cloexec(fd); | |
265 | break; | |
266 | } | |
267 | } | |
268 | ||
269 | /* set short latency */ | |
270 | if (socket_set_nodelay(fd)) { | |
271 | perror("setsockopt"); | |
272 | close(fd); | |
273 | return false; | |
274 | } | |
275 | ||
276 | gdb_accept_init(fd); | |
277 | return true; | |
278 | } | |
279 | ||
280 | static int gdbserver_open_port(int port) | |
281 | { | |
282 | struct sockaddr_in sockaddr; | |
283 | int fd, ret; | |
284 | ||
285 | fd = socket(PF_INET, SOCK_STREAM, 0); | |
286 | if (fd < 0) { | |
287 | perror("socket"); | |
288 | return -1; | |
289 | } | |
290 | qemu_set_cloexec(fd); | |
291 | ||
292 | socket_set_fast_reuse(fd); | |
293 | ||
294 | sockaddr.sin_family = AF_INET; | |
295 | sockaddr.sin_port = htons(port); | |
296 | sockaddr.sin_addr.s_addr = 0; | |
297 | ret = bind(fd, (struct sockaddr *)&sockaddr, sizeof(sockaddr)); | |
298 | if (ret < 0) { | |
299 | perror("bind"); | |
300 | close(fd); | |
301 | return -1; | |
302 | } | |
303 | ret = listen(fd, 1); | |
304 | if (ret < 0) { | |
305 | perror("listen"); | |
306 | close(fd); | |
307 | return -1; | |
308 | } | |
309 | ||
310 | return fd; | |
311 | } | |
312 | ||
313 | int gdbserver_start(const char *port_or_path) | |
314 | { | |
315 | int port = g_ascii_strtoull(port_or_path, NULL, 10); | |
316 | int gdb_fd; | |
317 | ||
318 | if (port > 0) { | |
319 | gdb_fd = gdbserver_open_port(port); | |
320 | } else { | |
321 | gdb_fd = gdbserver_open_socket(port_or_path); | |
322 | } | |
323 | ||
324 | if (gdb_fd < 0) { | |
325 | return -1; | |
326 | } | |
327 | ||
328 | if (port > 0 && gdb_accept_tcp(gdb_fd)) { | |
329 | return 0; | |
330 | } else if (gdb_accept_socket(gdb_fd)) { | |
331 | gdbserver_user_state.socket_path = g_strdup(port_or_path); | |
332 | return 0; | |
333 | } | |
334 | ||
335 | /* gone wrong */ | |
336 | close(gdb_fd); | |
337 | return -1; | |
338 | } | |
339 | ||
340 | /* Disable gdb stub for child processes. */ | |
341 | void gdbserver_fork(CPUState *cpu) | |
342 | { | |
343 | if (!gdbserver_state.init || gdbserver_user_state.fd < 0) { | |
344 | return; | |
345 | } | |
346 | close(gdbserver_user_state.fd); | |
347 | gdbserver_user_state.fd = -1; | |
348 | cpu_breakpoint_remove_all(cpu, BP_GDB); | |
349 | /* no cpu_watchpoint_remove_all for user-mode */ | |
350 | } | |
351 | ||
352 | /* | |
353 | * Execution state helpers | |
354 | */ | |
355 | ||
8a2025b3 AB |
356 | void gdb_handle_query_attached(GArray *params, void *user_ctx) |
357 | { | |
358 | gdb_put_packet("0"); | |
359 | } | |
360 | ||
d96bf49b AB |
361 | void gdb_continue(void) |
362 | { | |
363 | gdbserver_user_state.running_state = 1; | |
364 | trace_gdbstub_op_continue(); | |
365 | } | |
366 | ||
367 | /* | |
368 | * Resume execution, for user-mode emulation it's equivalent to | |
369 | * gdb_continue. | |
370 | */ | |
371 | int gdb_continue_partial(char *newstates) | |
372 | { | |
373 | CPUState *cpu; | |
374 | int res = 0; | |
375 | /* | |
376 | * This is not exactly accurate, but it's an improvement compared to the | |
377 | * previous situation, where only one CPU would be single-stepped. | |
378 | */ | |
379 | CPU_FOREACH(cpu) { | |
380 | if (newstates[cpu->cpu_index] == 's') { | |
381 | trace_gdbstub_op_stepping(cpu->cpu_index); | |
382 | cpu_single_step(cpu, gdbserver_state.sstep_flags); | |
383 | } | |
384 | } | |
385 | gdbserver_user_state.running_state = 1; | |
386 | return res; | |
387 | } | |
388 | ||
589a5867 AB |
389 | /* |
390 | * Memory access helpers | |
391 | */ | |
392 | int gdb_target_memory_rw_debug(CPUState *cpu, hwaddr addr, | |
393 | uint8_t *buf, int len, bool is_write) | |
394 | { | |
395 | CPUClass *cc; | |
396 | ||
397 | cc = CPU_GET_CLASS(cpu); | |
398 | if (cc->memory_rw_debug) { | |
399 | return cc->memory_rw_debug(cpu, addr, buf, len, is_write); | |
400 | } | |
401 | return cpu_memory_rw_debug(cpu, addr, buf, len, is_write); | |
402 | } | |
403 | ||
7ea0c33d AB |
404 | /* |
405 | * cpu helpers | |
406 | */ | |
407 | ||
408 | unsigned int gdb_get_max_cpus(void) | |
409 | { | |
410 | CPUState *cpu; | |
411 | unsigned int max_cpus = 1; | |
412 | ||
413 | CPU_FOREACH(cpu) { | |
414 | max_cpus = max_cpus <= cpu->cpu_index ? cpu->cpu_index + 1 : max_cpus; | |
415 | } | |
416 | ||
417 | return max_cpus; | |
418 | } | |
419 | ||
505601d5 AB |
420 | /* replay not supported for user-mode */ |
421 | bool gdb_can_reverse(void) | |
422 | { | |
423 | return false; | |
424 | } | |
7ea0c33d | 425 | |
d96bf49b AB |
426 | /* |
427 | * Break/Watch point helpers | |
428 | */ | |
429 | ||
a48e7d9e AB |
430 | bool gdb_supports_guest_debug(void) |
431 | { | |
432 | /* user-mode == TCG == supported */ | |
433 | return true; | |
434 | } | |
435 | ||
55b5b8e9 | 436 | int gdb_breakpoint_insert(CPUState *cs, int type, vaddr addr, vaddr len) |
ae7467b1 AB |
437 | { |
438 | CPUState *cpu; | |
439 | int err = 0; | |
440 | ||
441 | switch (type) { | |
442 | case GDB_BREAKPOINT_SW: | |
443 | case GDB_BREAKPOINT_HW: | |
444 | CPU_FOREACH(cpu) { | |
445 | err = cpu_breakpoint_insert(cpu, addr, BP_GDB, NULL); | |
446 | if (err) { | |
447 | break; | |
448 | } | |
449 | } | |
450 | return err; | |
451 | default: | |
452 | /* user-mode doesn't support watchpoints */ | |
453 | return -ENOSYS; | |
454 | } | |
455 | } | |
456 | ||
55b5b8e9 | 457 | int gdb_breakpoint_remove(CPUState *cs, int type, vaddr addr, vaddr len) |
ae7467b1 AB |
458 | { |
459 | CPUState *cpu; | |
460 | int err = 0; | |
461 | ||
462 | switch (type) { | |
463 | case GDB_BREAKPOINT_SW: | |
464 | case GDB_BREAKPOINT_HW: | |
465 | CPU_FOREACH(cpu) { | |
466 | err = cpu_breakpoint_remove(cpu, addr, BP_GDB); | |
467 | if (err) { | |
468 | break; | |
469 | } | |
470 | } | |
471 | return err; | |
472 | default: | |
473 | /* user-mode doesn't support watchpoints */ | |
474 | return -ENOSYS; | |
475 | } | |
476 | } | |
477 | ||
478 | void gdb_breakpoint_remove_all(CPUState *cs) | |
479 | { | |
480 | cpu_breakpoint_remove_all(cs, BP_GDB); | |
481 | } | |
131f387d AB |
482 | |
483 | /* | |
484 | * For user-mode syscall support we send the system call immediately | |
485 | * and then return control to gdb for it to process the syscall request. | |
486 | * Since the protocol requires that gdb hands control back to us | |
487 | * using a "here are the results" F packet, we don't need to check | |
488 | * gdb_handlesig's return value (which is the signal to deliver if | |
489 | * execution was resumed via a continue packet). | |
490 | */ | |
491 | void gdb_syscall_handling(const char *syscall_packet) | |
492 | { | |
493 | gdb_put_packet(syscall_packet); | |
494 | gdb_handlesig(gdbserver_state.c_cpu, 0); | |
495 | } |