]>
Commit | Line | Data |
---|---|---|
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 | ||
111 | snprintf(buf, sizeof(buf), "W%02x", (uint8_t)code); | |
112 | gdb_put_packet(buf); | |
113 | } | |
114 | ||
115 | int gdb_handlesig(CPUState *cpu, int sig) | |
116 | { | |
117 | char buf[256]; | |
118 | int n; | |
119 | ||
120 | if (!gdbserver_state.init || gdbserver_user_state.fd < 0) { | |
121 | return sig; | |
122 | } | |
123 | ||
124 | /* disable single step if it was enabled */ | |
125 | cpu_single_step(cpu, 0); | |
126 | tb_flush(cpu); | |
127 | ||
128 | if (sig != 0) { | |
129 | gdb_set_stop_cpu(cpu); | |
130 | g_string_printf(gdbserver_state.str_buf, | |
131 | "T%02xthread:", gdb_target_signal_to_gdb(sig)); | |
132 | gdb_append_thread_id(cpu, gdbserver_state.str_buf); | |
133 | g_string_append_c(gdbserver_state.str_buf, ';'); | |
134 | gdb_put_strbuf(); | |
135 | } | |
136 | /* | |
137 | * gdb_put_packet() might have detected that the peer terminated the | |
138 | * connection. | |
139 | */ | |
140 | if (gdbserver_user_state.fd < 0) { | |
141 | return sig; | |
142 | } | |
143 | ||
144 | sig = 0; | |
145 | gdbserver_state.state = RS_IDLE; | |
146 | gdbserver_user_state.running_state = 0; | |
147 | while (gdbserver_user_state.running_state == 0) { | |
148 | n = read(gdbserver_user_state.fd, buf, 256); | |
149 | if (n > 0) { | |
150 | int i; | |
151 | ||
152 | for (i = 0; i < n; i++) { | |
153 | gdb_read_byte(buf[i]); | |
154 | } | |
155 | } else { | |
156 | /* | |
157 | * XXX: Connection closed. Should probably wait for another | |
158 | * connection before continuing. | |
159 | */ | |
160 | if (n == 0) { | |
161 | close(gdbserver_user_state.fd); | |
162 | } | |
163 | gdbserver_user_state.fd = -1; | |
164 | return sig; | |
165 | } | |
166 | } | |
167 | sig = gdbserver_state.signal; | |
168 | gdbserver_state.signal = 0; | |
169 | return sig; | |
170 | } | |
171 | ||
172 | /* Tell the remote gdb that the process has exited due to SIG. */ | |
173 | void gdb_signalled(CPUArchState *env, int sig) | |
174 | { | |
175 | char buf[4]; | |
176 | ||
177 | if (!gdbserver_state.init || gdbserver_user_state.fd < 0) { | |
178 | return; | |
179 | } | |
180 | ||
181 | snprintf(buf, sizeof(buf), "X%02x", gdb_target_signal_to_gdb(sig)); | |
182 | gdb_put_packet(buf); | |
183 | } | |
184 | ||
185 | static void gdb_accept_init(int fd) | |
186 | { | |
187 | gdb_init_gdbserver_state(); | |
188 | gdb_create_default_process(&gdbserver_state); | |
189 | gdbserver_state.processes[0].attached = true; | |
190 | gdbserver_state.c_cpu = gdb_first_attached_cpu(); | |
191 | gdbserver_state.g_cpu = gdbserver_state.c_cpu; | |
192 | gdbserver_user_state.fd = fd; | |
193 | gdb_has_xml = false; | |
194 | } | |
195 | ||
196 | static bool gdb_accept_socket(int gdb_fd) | |
197 | { | |
198 | int fd; | |
199 | ||
200 | for (;;) { | |
201 | fd = accept(gdb_fd, NULL, NULL); | |
202 | if (fd < 0 && errno != EINTR) { | |
203 | perror("accept socket"); | |
204 | return false; | |
205 | } else if (fd >= 0) { | |
206 | qemu_set_cloexec(fd); | |
207 | break; | |
208 | } | |
209 | } | |
210 | ||
211 | gdb_accept_init(fd); | |
212 | return true; | |
213 | } | |
214 | ||
215 | static int gdbserver_open_socket(const char *path) | |
216 | { | |
217 | struct sockaddr_un sockaddr = {}; | |
218 | int fd, ret; | |
219 | ||
220 | fd = socket(AF_UNIX, SOCK_STREAM, 0); | |
221 | if (fd < 0) { | |
222 | perror("create socket"); | |
223 | return -1; | |
224 | } | |
225 | ||
226 | sockaddr.sun_family = AF_UNIX; | |
227 | pstrcpy(sockaddr.sun_path, sizeof(sockaddr.sun_path) - 1, path); | |
228 | ret = bind(fd, (struct sockaddr *)&sockaddr, sizeof(sockaddr)); | |
229 | if (ret < 0) { | |
230 | perror("bind socket"); | |
231 | close(fd); | |
232 | return -1; | |
233 | } | |
234 | ret = listen(fd, 1); | |
235 | if (ret < 0) { | |
236 | perror("listen socket"); | |
237 | close(fd); | |
238 | return -1; | |
239 | } | |
240 | ||
241 | return fd; | |
242 | } | |
243 | ||
244 | static bool gdb_accept_tcp(int gdb_fd) | |
245 | { | |
246 | struct sockaddr_in sockaddr = {}; | |
247 | socklen_t len; | |
248 | int fd; | |
249 | ||
250 | for (;;) { | |
251 | len = sizeof(sockaddr); | |
252 | fd = accept(gdb_fd, (struct sockaddr *)&sockaddr, &len); | |
253 | if (fd < 0 && errno != EINTR) { | |
254 | perror("accept"); | |
255 | return false; | |
256 | } else if (fd >= 0) { | |
257 | qemu_set_cloexec(fd); | |
258 | break; | |
259 | } | |
260 | } | |
261 | ||
262 | /* set short latency */ | |
263 | if (socket_set_nodelay(fd)) { | |
264 | perror("setsockopt"); | |
265 | close(fd); | |
266 | return false; | |
267 | } | |
268 | ||
269 | gdb_accept_init(fd); | |
270 | return true; | |
271 | } | |
272 | ||
273 | static int gdbserver_open_port(int port) | |
274 | { | |
275 | struct sockaddr_in sockaddr; | |
276 | int fd, ret; | |
277 | ||
278 | fd = socket(PF_INET, SOCK_STREAM, 0); | |
279 | if (fd < 0) { | |
280 | perror("socket"); | |
281 | return -1; | |
282 | } | |
283 | qemu_set_cloexec(fd); | |
284 | ||
285 | socket_set_fast_reuse(fd); | |
286 | ||
287 | sockaddr.sin_family = AF_INET; | |
288 | sockaddr.sin_port = htons(port); | |
289 | sockaddr.sin_addr.s_addr = 0; | |
290 | ret = bind(fd, (struct sockaddr *)&sockaddr, sizeof(sockaddr)); | |
291 | if (ret < 0) { | |
292 | perror("bind"); | |
293 | close(fd); | |
294 | return -1; | |
295 | } | |
296 | ret = listen(fd, 1); | |
297 | if (ret < 0) { | |
298 | perror("listen"); | |
299 | close(fd); | |
300 | return -1; | |
301 | } | |
302 | ||
303 | return fd; | |
304 | } | |
305 | ||
306 | int gdbserver_start(const char *port_or_path) | |
307 | { | |
308 | int port = g_ascii_strtoull(port_or_path, NULL, 10); | |
309 | int gdb_fd; | |
310 | ||
311 | if (port > 0) { | |
312 | gdb_fd = gdbserver_open_port(port); | |
313 | } else { | |
314 | gdb_fd = gdbserver_open_socket(port_or_path); | |
315 | } | |
316 | ||
317 | if (gdb_fd < 0) { | |
318 | return -1; | |
319 | } | |
320 | ||
321 | if (port > 0 && gdb_accept_tcp(gdb_fd)) { | |
322 | return 0; | |
323 | } else if (gdb_accept_socket(gdb_fd)) { | |
324 | gdbserver_user_state.socket_path = g_strdup(port_or_path); | |
325 | return 0; | |
326 | } | |
327 | ||
328 | /* gone wrong */ | |
329 | close(gdb_fd); | |
330 | return -1; | |
331 | } | |
332 | ||
333 | /* Disable gdb stub for child processes. */ | |
334 | void gdbserver_fork(CPUState *cpu) | |
335 | { | |
336 | if (!gdbserver_state.init || gdbserver_user_state.fd < 0) { | |
337 | return; | |
338 | } | |
339 | close(gdbserver_user_state.fd); | |
340 | gdbserver_user_state.fd = -1; | |
341 | cpu_breakpoint_remove_all(cpu, BP_GDB); | |
342 | /* no cpu_watchpoint_remove_all for user-mode */ | |
343 | } | |
344 | ||
345 | /* | |
346 | * Execution state helpers | |
347 | */ | |
348 | ||
8a2025b3 AB |
349 | void gdb_handle_query_attached(GArray *params, void *user_ctx) |
350 | { | |
351 | gdb_put_packet("0"); | |
352 | } | |
353 | ||
d96bf49b AB |
354 | void gdb_continue(void) |
355 | { | |
356 | gdbserver_user_state.running_state = 1; | |
357 | trace_gdbstub_op_continue(); | |
358 | } | |
359 | ||
360 | /* | |
361 | * Resume execution, for user-mode emulation it's equivalent to | |
362 | * gdb_continue. | |
363 | */ | |
364 | int gdb_continue_partial(char *newstates) | |
365 | { | |
366 | CPUState *cpu; | |
367 | int res = 0; | |
368 | /* | |
369 | * This is not exactly accurate, but it's an improvement compared to the | |
370 | * previous situation, where only one CPU would be single-stepped. | |
371 | */ | |
372 | CPU_FOREACH(cpu) { | |
373 | if (newstates[cpu->cpu_index] == 's') { | |
374 | trace_gdbstub_op_stepping(cpu->cpu_index); | |
375 | cpu_single_step(cpu, gdbserver_state.sstep_flags); | |
376 | } | |
377 | } | |
378 | gdbserver_user_state.running_state = 1; | |
379 | return res; | |
380 | } | |
381 | ||
589a5867 AB |
382 | /* |
383 | * Memory access helpers | |
384 | */ | |
385 | int gdb_target_memory_rw_debug(CPUState *cpu, hwaddr addr, | |
386 | uint8_t *buf, int len, bool is_write) | |
387 | { | |
388 | CPUClass *cc; | |
389 | ||
390 | cc = CPU_GET_CLASS(cpu); | |
391 | if (cc->memory_rw_debug) { | |
392 | return cc->memory_rw_debug(cpu, addr, buf, len, is_write); | |
393 | } | |
394 | return cpu_memory_rw_debug(cpu, addr, buf, len, is_write); | |
395 | } | |
396 | ||
7ea0c33d AB |
397 | /* |
398 | * cpu helpers | |
399 | */ | |
400 | ||
401 | unsigned int gdb_get_max_cpus(void) | |
402 | { | |
403 | CPUState *cpu; | |
404 | unsigned int max_cpus = 1; | |
405 | ||
406 | CPU_FOREACH(cpu) { | |
407 | max_cpus = max_cpus <= cpu->cpu_index ? cpu->cpu_index + 1 : max_cpus; | |
408 | } | |
409 | ||
410 | return max_cpus; | |
411 | } | |
412 | ||
505601d5 AB |
413 | /* replay not supported for user-mode */ |
414 | bool gdb_can_reverse(void) | |
415 | { | |
416 | return false; | |
417 | } | |
7ea0c33d | 418 | |
d96bf49b AB |
419 | /* |
420 | * Break/Watch point helpers | |
421 | */ | |
422 | ||
a48e7d9e AB |
423 | bool gdb_supports_guest_debug(void) |
424 | { | |
425 | /* user-mode == TCG == supported */ | |
426 | return true; | |
427 | } | |
428 | ||
55b5b8e9 | 429 | int gdb_breakpoint_insert(CPUState *cs, int type, vaddr addr, vaddr len) |
ae7467b1 AB |
430 | { |
431 | CPUState *cpu; | |
432 | int err = 0; | |
433 | ||
434 | switch (type) { | |
435 | case GDB_BREAKPOINT_SW: | |
436 | case GDB_BREAKPOINT_HW: | |
437 | CPU_FOREACH(cpu) { | |
438 | err = cpu_breakpoint_insert(cpu, addr, BP_GDB, NULL); | |
439 | if (err) { | |
440 | break; | |
441 | } | |
442 | } | |
443 | return err; | |
444 | default: | |
445 | /* user-mode doesn't support watchpoints */ | |
446 | return -ENOSYS; | |
447 | } | |
448 | } | |
449 | ||
55b5b8e9 | 450 | int gdb_breakpoint_remove(CPUState *cs, int type, vaddr addr, vaddr len) |
ae7467b1 AB |
451 | { |
452 | CPUState *cpu; | |
453 | int err = 0; | |
454 | ||
455 | switch (type) { | |
456 | case GDB_BREAKPOINT_SW: | |
457 | case GDB_BREAKPOINT_HW: | |
458 | CPU_FOREACH(cpu) { | |
459 | err = cpu_breakpoint_remove(cpu, addr, BP_GDB); | |
460 | if (err) { | |
461 | break; | |
462 | } | |
463 | } | |
464 | return err; | |
465 | default: | |
466 | /* user-mode doesn't support watchpoints */ | |
467 | return -ENOSYS; | |
468 | } | |
469 | } | |
470 | ||
471 | void gdb_breakpoint_remove_all(CPUState *cs) | |
472 | { | |
473 | cpu_breakpoint_remove_all(cs, BP_GDB); | |
474 | } | |
131f387d AB |
475 | |
476 | /* | |
477 | * For user-mode syscall support we send the system call immediately | |
478 | * and then return control to gdb for it to process the syscall request. | |
479 | * Since the protocol requires that gdb hands control back to us | |
480 | * using a "here are the results" F packet, we don't need to check | |
481 | * gdb_handlesig's return value (which is the signal to deliver if | |
482 | * execution was resumed via a continue packet). | |
483 | */ | |
484 | void gdb_syscall_handling(const char *syscall_packet) | |
485 | { | |
486 | gdb_put_packet(syscall_packet); | |
487 | gdb_handlesig(gdbserver_state.c_cpu, 0); | |
488 | } |