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53197fc4 JW |
1 | /* |
2 | * Kernel Debug Core | |
3 | * | |
4 | * Maintainer: Jason Wessel <jason.wessel@windriver.com> | |
5 | * | |
6 | * Copyright (C) 2000-2001 VERITAS Software Corporation. | |
7 | * Copyright (C) 2002-2004 Timesys Corporation | |
8 | * Copyright (C) 2003-2004 Amit S. Kale <amitkale@linsyssoft.com> | |
9 | * Copyright (C) 2004 Pavel Machek <pavel@suse.cz> | |
10 | * Copyright (C) 2004-2006 Tom Rini <trini@kernel.crashing.org> | |
11 | * Copyright (C) 2004-2006 LinSysSoft Technologies Pvt. Ltd. | |
12 | * Copyright (C) 2005-2009 Wind River Systems, Inc. | |
13 | * Copyright (C) 2007 MontaVista Software, Inc. | |
14 | * Copyright (C) 2008 Red Hat, Inc., Ingo Molnar <mingo@redhat.com> | |
15 | * | |
16 | * Contributors at various stages not listed above: | |
17 | * Jason Wessel ( jason.wessel@windriver.com ) | |
18 | * George Anzinger <george@mvista.com> | |
19 | * Anurekh Saxena (anurekh.saxena@timesys.com) | |
20 | * Lake Stevens Instrument Division (Glenn Engel) | |
21 | * Jim Kingdon, Cygnus Support. | |
22 | * | |
23 | * Original KGDB stub: David Grothe <dave@gcom.com>, | |
24 | * Tigran Aivazian <tigran@sco.com> | |
25 | * | |
26 | * This file is licensed under the terms of the GNU General Public License | |
27 | * version 2. This program is licensed "as is" without any warranty of any | |
28 | * kind, whether express or implied. | |
29 | */ | |
30 | ||
31 | #include <linux/kernel.h> | |
32 | #include <linux/kgdb.h> | |
33 | #include <linux/reboot.h> | |
34 | #include <linux/uaccess.h> | |
35 | #include <asm/cacheflush.h> | |
36 | #include <asm/unaligned.h> | |
37 | #include "debug_core.h" | |
38 | ||
39 | #define KGDB_MAX_THREAD_QUERY 17 | |
40 | ||
41 | /* Our I/O buffers. */ | |
42 | static char remcom_in_buffer[BUFMAX]; | |
43 | static char remcom_out_buffer[BUFMAX]; | |
44 | ||
45 | /* Storage for the registers, in GDB format. */ | |
46 | static unsigned long gdb_regs[(NUMREGBYTES + | |
47 | sizeof(unsigned long) - 1) / | |
48 | sizeof(unsigned long)]; | |
49 | ||
50 | /* | |
51 | * GDB remote protocol parser: | |
52 | */ | |
53 | ||
54 | static int hex(char ch) | |
55 | { | |
56 | if ((ch >= 'a') && (ch <= 'f')) | |
57 | return ch - 'a' + 10; | |
58 | if ((ch >= '0') && (ch <= '9')) | |
59 | return ch - '0'; | |
60 | if ((ch >= 'A') && (ch <= 'F')) | |
61 | return ch - 'A' + 10; | |
62 | return -1; | |
63 | } | |
64 | ||
65 | /* scan for the sequence $<data>#<checksum> */ | |
66 | static void get_packet(char *buffer) | |
67 | { | |
68 | unsigned char checksum; | |
69 | unsigned char xmitcsum; | |
70 | int count; | |
71 | char ch; | |
72 | ||
73 | do { | |
74 | /* | |
75 | * Spin and wait around for the start character, ignore all | |
76 | * other characters: | |
77 | */ | |
78 | while ((ch = (dbg_io_ops->read_char())) != '$') | |
79 | /* nothing */; | |
80 | ||
81 | kgdb_connected = 1; | |
82 | checksum = 0; | |
83 | xmitcsum = -1; | |
84 | ||
85 | count = 0; | |
86 | ||
87 | /* | |
88 | * now, read until a # or end of buffer is found: | |
89 | */ | |
90 | while (count < (BUFMAX - 1)) { | |
91 | ch = dbg_io_ops->read_char(); | |
92 | if (ch == '#') | |
93 | break; | |
94 | checksum = checksum + ch; | |
95 | buffer[count] = ch; | |
96 | count = count + 1; | |
97 | } | |
98 | buffer[count] = 0; | |
99 | ||
100 | if (ch == '#') { | |
101 | xmitcsum = hex(dbg_io_ops->read_char()) << 4; | |
102 | xmitcsum += hex(dbg_io_ops->read_char()); | |
103 | ||
104 | if (checksum != xmitcsum) | |
105 | /* failed checksum */ | |
106 | dbg_io_ops->write_char('-'); | |
107 | else | |
108 | /* successful transfer */ | |
109 | dbg_io_ops->write_char('+'); | |
110 | if (dbg_io_ops->flush) | |
111 | dbg_io_ops->flush(); | |
112 | } | |
113 | } while (checksum != xmitcsum); | |
114 | } | |
115 | ||
116 | /* | |
117 | * Send the packet in buffer. | |
118 | * Check for gdb connection if asked for. | |
119 | */ | |
120 | static void put_packet(char *buffer) | |
121 | { | |
122 | unsigned char checksum; | |
123 | int count; | |
124 | char ch; | |
125 | ||
126 | /* | |
127 | * $<packet info>#<checksum>. | |
128 | */ | |
129 | while (1) { | |
130 | dbg_io_ops->write_char('$'); | |
131 | checksum = 0; | |
132 | count = 0; | |
133 | ||
134 | while ((ch = buffer[count])) { | |
135 | dbg_io_ops->write_char(ch); | |
136 | checksum += ch; | |
137 | count++; | |
138 | } | |
139 | ||
140 | dbg_io_ops->write_char('#'); | |
141 | dbg_io_ops->write_char(hex_asc_hi(checksum)); | |
142 | dbg_io_ops->write_char(hex_asc_lo(checksum)); | |
143 | if (dbg_io_ops->flush) | |
144 | dbg_io_ops->flush(); | |
145 | ||
146 | /* Now see what we get in reply. */ | |
147 | ch = dbg_io_ops->read_char(); | |
148 | ||
149 | if (ch == 3) | |
150 | ch = dbg_io_ops->read_char(); | |
151 | ||
152 | /* If we get an ACK, we are done. */ | |
153 | if (ch == '+') | |
154 | return; | |
155 | ||
156 | /* | |
157 | * If we get the start of another packet, this means | |
158 | * that GDB is attempting to reconnect. We will NAK | |
159 | * the packet being sent, and stop trying to send this | |
160 | * packet. | |
161 | */ | |
162 | if (ch == '$') { | |
163 | dbg_io_ops->write_char('-'); | |
164 | if (dbg_io_ops->flush) | |
165 | dbg_io_ops->flush(); | |
166 | return; | |
167 | } | |
168 | } | |
169 | } | |
170 | ||
171 | static char gdbmsgbuf[BUFMAX + 1]; | |
172 | ||
173 | void gdbstub_msg_write(const char *s, int len) | |
174 | { | |
175 | char *bufptr; | |
176 | int wcount; | |
177 | int i; | |
178 | ||
179 | /* 'O'utput */ | |
180 | gdbmsgbuf[0] = 'O'; | |
181 | ||
182 | /* Fill and send buffers... */ | |
183 | while (len > 0) { | |
184 | bufptr = gdbmsgbuf + 1; | |
185 | ||
186 | /* Calculate how many this time */ | |
187 | if ((len << 1) > (BUFMAX - 2)) | |
188 | wcount = (BUFMAX - 2) >> 1; | |
189 | else | |
190 | wcount = len; | |
191 | ||
192 | /* Pack in hex chars */ | |
193 | for (i = 0; i < wcount; i++) | |
194 | bufptr = pack_hex_byte(bufptr, s[i]); | |
195 | *bufptr = '\0'; | |
196 | ||
197 | /* Move up */ | |
198 | s += wcount; | |
199 | len -= wcount; | |
200 | ||
201 | /* Write packet */ | |
202 | put_packet(gdbmsgbuf); | |
203 | } | |
204 | } | |
205 | ||
206 | /* | |
207 | * Convert the memory pointed to by mem into hex, placing result in | |
208 | * buf. Return a pointer to the last char put in buf (null). May | |
209 | * return an error. | |
210 | */ | |
211 | int kgdb_mem2hex(char *mem, char *buf, int count) | |
212 | { | |
213 | char *tmp; | |
214 | int err; | |
215 | ||
216 | /* | |
217 | * We use the upper half of buf as an intermediate buffer for the | |
218 | * raw memory copy. Hex conversion will work against this one. | |
219 | */ | |
220 | tmp = buf + count; | |
221 | ||
222 | err = probe_kernel_read(tmp, mem, count); | |
223 | if (!err) { | |
224 | while (count > 0) { | |
225 | buf = pack_hex_byte(buf, *tmp); | |
226 | tmp++; | |
227 | count--; | |
228 | } | |
229 | ||
230 | *buf = 0; | |
231 | } | |
232 | ||
233 | return err; | |
234 | } | |
235 | ||
236 | /* | |
237 | * Convert the hex array pointed to by buf into binary to be placed in | |
238 | * mem. Return a pointer to the character AFTER the last byte | |
239 | * written. May return an error. | |
240 | */ | |
241 | int kgdb_hex2mem(char *buf, char *mem, int count) | |
242 | { | |
243 | char *tmp_raw; | |
244 | char *tmp_hex; | |
245 | ||
246 | /* | |
247 | * We use the upper half of buf as an intermediate buffer for the | |
248 | * raw memory that is converted from hex. | |
249 | */ | |
250 | tmp_raw = buf + count * 2; | |
251 | ||
252 | tmp_hex = tmp_raw - 1; | |
253 | while (tmp_hex >= buf) { | |
254 | tmp_raw--; | |
255 | *tmp_raw = hex(*tmp_hex--); | |
256 | *tmp_raw |= hex(*tmp_hex--) << 4; | |
257 | } | |
258 | ||
259 | return probe_kernel_write(mem, tmp_raw, count); | |
260 | } | |
261 | ||
262 | /* | |
263 | * While we find nice hex chars, build a long_val. | |
264 | * Return number of chars processed. | |
265 | */ | |
266 | int kgdb_hex2long(char **ptr, unsigned long *long_val) | |
267 | { | |
268 | int hex_val; | |
269 | int num = 0; | |
270 | int negate = 0; | |
271 | ||
272 | *long_val = 0; | |
273 | ||
274 | if (**ptr == '-') { | |
275 | negate = 1; | |
276 | (*ptr)++; | |
277 | } | |
278 | while (**ptr) { | |
279 | hex_val = hex(**ptr); | |
280 | if (hex_val < 0) | |
281 | break; | |
282 | ||
283 | *long_val = (*long_val << 4) | hex_val; | |
284 | num++; | |
285 | (*ptr)++; | |
286 | } | |
287 | ||
288 | if (negate) | |
289 | *long_val = -*long_val; | |
290 | ||
291 | return num; | |
292 | } | |
293 | ||
294 | /* | |
295 | * Copy the binary array pointed to by buf into mem. Fix $, #, and | |
296 | * 0x7d escaped with 0x7d. Return -EFAULT on failure or 0 on success. | |
297 | * The input buf is overwitten with the result to write to mem. | |
298 | */ | |
299 | static int kgdb_ebin2mem(char *buf, char *mem, int count) | |
300 | { | |
301 | int size = 0; | |
302 | char *c = buf; | |
303 | ||
304 | while (count-- > 0) { | |
305 | c[size] = *buf++; | |
306 | if (c[size] == 0x7d) | |
307 | c[size] = *buf++ ^ 0x20; | |
308 | size++; | |
309 | } | |
310 | ||
311 | return probe_kernel_write(mem, c, size); | |
312 | } | |
313 | ||
314 | /* Write memory due to an 'M' or 'X' packet. */ | |
315 | static int write_mem_msg(int binary) | |
316 | { | |
317 | char *ptr = &remcom_in_buffer[1]; | |
318 | unsigned long addr; | |
319 | unsigned long length; | |
320 | int err; | |
321 | ||
322 | if (kgdb_hex2long(&ptr, &addr) > 0 && *(ptr++) == ',' && | |
323 | kgdb_hex2long(&ptr, &length) > 0 && *(ptr++) == ':') { | |
324 | if (binary) | |
325 | err = kgdb_ebin2mem(ptr, (char *)addr, length); | |
326 | else | |
327 | err = kgdb_hex2mem(ptr, (char *)addr, length); | |
328 | if (err) | |
329 | return err; | |
330 | if (CACHE_FLUSH_IS_SAFE) | |
331 | flush_icache_range(addr, addr + length); | |
332 | return 0; | |
333 | } | |
334 | ||
335 | return -EINVAL; | |
336 | } | |
337 | ||
338 | static void error_packet(char *pkt, int error) | |
339 | { | |
340 | error = -error; | |
341 | pkt[0] = 'E'; | |
342 | pkt[1] = hex_asc[(error / 10)]; | |
343 | pkt[2] = hex_asc[(error % 10)]; | |
344 | pkt[3] = '\0'; | |
345 | } | |
346 | ||
347 | /* | |
348 | * Thread ID accessors. We represent a flat TID space to GDB, where | |
349 | * the per CPU idle threads (which under Linux all have PID 0) are | |
350 | * remapped to negative TIDs. | |
351 | */ | |
352 | ||
353 | #define BUF_THREAD_ID_SIZE 16 | |
354 | ||
355 | static char *pack_threadid(char *pkt, unsigned char *id) | |
356 | { | |
357 | char *limit; | |
358 | ||
359 | limit = pkt + BUF_THREAD_ID_SIZE; | |
360 | while (pkt < limit) | |
361 | pkt = pack_hex_byte(pkt, *id++); | |
362 | ||
363 | return pkt; | |
364 | } | |
365 | ||
366 | static void int_to_threadref(unsigned char *id, int value) | |
367 | { | |
368 | unsigned char *scan; | |
369 | int i = 4; | |
370 | ||
371 | scan = (unsigned char *)id; | |
372 | while (i--) | |
373 | *scan++ = 0; | |
374 | put_unaligned_be32(value, scan); | |
375 | } | |
376 | ||
377 | static struct task_struct *getthread(struct pt_regs *regs, int tid) | |
378 | { | |
379 | /* | |
380 | * Non-positive TIDs are remapped to the cpu shadow information | |
381 | */ | |
382 | if (tid == 0 || tid == -1) | |
383 | tid = -atomic_read(&kgdb_active) - 2; | |
384 | if (tid < -1 && tid > -NR_CPUS - 2) { | |
385 | if (kgdb_info[-tid - 2].task) | |
386 | return kgdb_info[-tid - 2].task; | |
387 | else | |
388 | return idle_task(-tid - 2); | |
389 | } | |
390 | if (tid <= 0) { | |
391 | printk(KERN_ERR "KGDB: Internal thread select error\n"); | |
392 | dump_stack(); | |
393 | return NULL; | |
394 | } | |
395 | ||
396 | /* | |
397 | * find_task_by_pid_ns() does not take the tasklist lock anymore | |
398 | * but is nicely RCU locked - hence is a pretty resilient | |
399 | * thing to use: | |
400 | */ | |
401 | return find_task_by_pid_ns(tid, &init_pid_ns); | |
402 | } | |
403 | ||
404 | ||
405 | /* | |
406 | * Remap normal tasks to their real PID, | |
407 | * CPU shadow threads are mapped to -CPU - 2 | |
408 | */ | |
409 | static inline int shadow_pid(int realpid) | |
410 | { | |
411 | if (realpid) | |
412 | return realpid; | |
413 | ||
414 | return -raw_smp_processor_id() - 2; | |
415 | } | |
416 | ||
417 | /* | |
418 | * All the functions that start with gdb_cmd are the various | |
419 | * operations to implement the handlers for the gdbserial protocol | |
420 | * where KGDB is communicating with an external debugger | |
421 | */ | |
422 | ||
423 | /* Handle the '?' status packets */ | |
424 | static void gdb_cmd_status(struct kgdb_state *ks) | |
425 | { | |
426 | /* | |
427 | * We know that this packet is only sent | |
428 | * during initial connect. So to be safe, | |
429 | * we clear out our breakpoints now in case | |
430 | * GDB is reconnecting. | |
431 | */ | |
432 | dbg_remove_all_break(); | |
433 | ||
434 | remcom_out_buffer[0] = 'S'; | |
435 | pack_hex_byte(&remcom_out_buffer[1], ks->signo); | |
436 | } | |
437 | ||
438 | /* Handle the 'g' get registers request */ | |
439 | static void gdb_cmd_getregs(struct kgdb_state *ks) | |
440 | { | |
441 | struct task_struct *thread; | |
442 | void *local_debuggerinfo; | |
443 | int i; | |
444 | ||
445 | thread = kgdb_usethread; | |
446 | if (!thread) { | |
447 | thread = kgdb_info[ks->cpu].task; | |
448 | local_debuggerinfo = kgdb_info[ks->cpu].debuggerinfo; | |
449 | } else { | |
450 | local_debuggerinfo = NULL; | |
451 | for_each_online_cpu(i) { | |
452 | /* | |
453 | * Try to find the task on some other | |
454 | * or possibly this node if we do not | |
455 | * find the matching task then we try | |
456 | * to approximate the results. | |
457 | */ | |
458 | if (thread == kgdb_info[i].task) | |
459 | local_debuggerinfo = kgdb_info[i].debuggerinfo; | |
460 | } | |
461 | } | |
462 | ||
463 | /* | |
464 | * All threads that don't have debuggerinfo should be | |
465 | * in schedule() sleeping, since all other CPUs | |
466 | * are in kgdb_wait, and thus have debuggerinfo. | |
467 | */ | |
468 | if (local_debuggerinfo) { | |
469 | pt_regs_to_gdb_regs(gdb_regs, local_debuggerinfo); | |
470 | } else { | |
471 | /* | |
472 | * Pull stuff saved during switch_to; nothing | |
473 | * else is accessible (or even particularly | |
474 | * relevant). | |
475 | * | |
476 | * This should be enough for a stack trace. | |
477 | */ | |
478 | sleeping_thread_to_gdb_regs(gdb_regs, thread); | |
479 | } | |
480 | kgdb_mem2hex((char *)gdb_regs, remcom_out_buffer, NUMREGBYTES); | |
481 | } | |
482 | ||
483 | /* Handle the 'G' set registers request */ | |
484 | static void gdb_cmd_setregs(struct kgdb_state *ks) | |
485 | { | |
486 | kgdb_hex2mem(&remcom_in_buffer[1], (char *)gdb_regs, NUMREGBYTES); | |
487 | ||
488 | if (kgdb_usethread && kgdb_usethread != current) { | |
489 | error_packet(remcom_out_buffer, -EINVAL); | |
490 | } else { | |
491 | gdb_regs_to_pt_regs(gdb_regs, ks->linux_regs); | |
492 | strcpy(remcom_out_buffer, "OK"); | |
493 | } | |
494 | } | |
495 | ||
496 | /* Handle the 'm' memory read bytes */ | |
497 | static void gdb_cmd_memread(struct kgdb_state *ks) | |
498 | { | |
499 | char *ptr = &remcom_in_buffer[1]; | |
500 | unsigned long length; | |
501 | unsigned long addr; | |
502 | int err; | |
503 | ||
504 | if (kgdb_hex2long(&ptr, &addr) > 0 && *ptr++ == ',' && | |
505 | kgdb_hex2long(&ptr, &length) > 0) { | |
506 | err = kgdb_mem2hex((char *)addr, remcom_out_buffer, length); | |
507 | if (err) | |
508 | error_packet(remcom_out_buffer, err); | |
509 | } else { | |
510 | error_packet(remcom_out_buffer, -EINVAL); | |
511 | } | |
512 | } | |
513 | ||
514 | /* Handle the 'M' memory write bytes */ | |
515 | static void gdb_cmd_memwrite(struct kgdb_state *ks) | |
516 | { | |
517 | int err = write_mem_msg(0); | |
518 | ||
519 | if (err) | |
520 | error_packet(remcom_out_buffer, err); | |
521 | else | |
522 | strcpy(remcom_out_buffer, "OK"); | |
523 | } | |
524 | ||
525 | /* Handle the 'X' memory binary write bytes */ | |
526 | static void gdb_cmd_binwrite(struct kgdb_state *ks) | |
527 | { | |
528 | int err = write_mem_msg(1); | |
529 | ||
530 | if (err) | |
531 | error_packet(remcom_out_buffer, err); | |
532 | else | |
533 | strcpy(remcom_out_buffer, "OK"); | |
534 | } | |
535 | ||
536 | /* Handle the 'D' or 'k', detach or kill packets */ | |
537 | static void gdb_cmd_detachkill(struct kgdb_state *ks) | |
538 | { | |
539 | int error; | |
540 | ||
541 | /* The detach case */ | |
542 | if (remcom_in_buffer[0] == 'D') { | |
543 | error = dbg_remove_all_break(); | |
544 | if (error < 0) { | |
545 | error_packet(remcom_out_buffer, error); | |
546 | } else { | |
547 | strcpy(remcom_out_buffer, "OK"); | |
548 | kgdb_connected = 0; | |
549 | } | |
550 | put_packet(remcom_out_buffer); | |
551 | } else { | |
552 | /* | |
553 | * Assume the kill case, with no exit code checking, | |
554 | * trying to force detach the debugger: | |
555 | */ | |
556 | dbg_remove_all_break(); | |
557 | kgdb_connected = 0; | |
558 | } | |
559 | } | |
560 | ||
561 | /* Handle the 'R' reboot packets */ | |
562 | static int gdb_cmd_reboot(struct kgdb_state *ks) | |
563 | { | |
564 | /* For now, only honor R0 */ | |
565 | if (strcmp(remcom_in_buffer, "R0") == 0) { | |
566 | printk(KERN_CRIT "Executing emergency reboot\n"); | |
567 | strcpy(remcom_out_buffer, "OK"); | |
568 | put_packet(remcom_out_buffer); | |
569 | ||
570 | /* | |
571 | * Execution should not return from | |
572 | * machine_emergency_restart() | |
573 | */ | |
574 | machine_emergency_restart(); | |
575 | kgdb_connected = 0; | |
576 | ||
577 | return 1; | |
578 | } | |
579 | return 0; | |
580 | } | |
581 | ||
582 | /* Handle the 'q' query packets */ | |
583 | static void gdb_cmd_query(struct kgdb_state *ks) | |
584 | { | |
585 | struct task_struct *g; | |
586 | struct task_struct *p; | |
587 | unsigned char thref[8]; | |
588 | char *ptr; | |
589 | int i; | |
590 | int cpu; | |
591 | int finished = 0; | |
592 | ||
593 | switch (remcom_in_buffer[1]) { | |
594 | case 's': | |
595 | case 'f': | |
596 | if (memcmp(remcom_in_buffer + 2, "ThreadInfo", 10)) { | |
597 | error_packet(remcom_out_buffer, -EINVAL); | |
598 | break; | |
599 | } | |
600 | ||
601 | i = 0; | |
602 | remcom_out_buffer[0] = 'm'; | |
603 | ptr = remcom_out_buffer + 1; | |
604 | if (remcom_in_buffer[1] == 'f') { | |
605 | /* Each cpu is a shadow thread */ | |
606 | for_each_online_cpu(cpu) { | |
607 | ks->thr_query = 0; | |
608 | int_to_threadref(thref, -cpu - 2); | |
609 | pack_threadid(ptr, thref); | |
610 | ptr += BUF_THREAD_ID_SIZE; | |
611 | *(ptr++) = ','; | |
612 | i++; | |
613 | } | |
614 | } | |
615 | ||
616 | do_each_thread(g, p) { | |
617 | if (i >= ks->thr_query && !finished) { | |
618 | int_to_threadref(thref, p->pid); | |
619 | pack_threadid(ptr, thref); | |
620 | ptr += BUF_THREAD_ID_SIZE; | |
621 | *(ptr++) = ','; | |
622 | ks->thr_query++; | |
623 | if (ks->thr_query % KGDB_MAX_THREAD_QUERY == 0) | |
624 | finished = 1; | |
625 | } | |
626 | i++; | |
627 | } while_each_thread(g, p); | |
628 | ||
629 | *(--ptr) = '\0'; | |
630 | break; | |
631 | ||
632 | case 'C': | |
633 | /* Current thread id */ | |
634 | strcpy(remcom_out_buffer, "QC"); | |
635 | ks->threadid = shadow_pid(current->pid); | |
636 | int_to_threadref(thref, ks->threadid); | |
637 | pack_threadid(remcom_out_buffer + 2, thref); | |
638 | break; | |
639 | case 'T': | |
640 | if (memcmp(remcom_in_buffer + 1, "ThreadExtraInfo,", 16)) { | |
641 | error_packet(remcom_out_buffer, -EINVAL); | |
642 | break; | |
643 | } | |
644 | ks->threadid = 0; | |
645 | ptr = remcom_in_buffer + 17; | |
646 | kgdb_hex2long(&ptr, &ks->threadid); | |
647 | if (!getthread(ks->linux_regs, ks->threadid)) { | |
648 | error_packet(remcom_out_buffer, -EINVAL); | |
649 | break; | |
650 | } | |
651 | if ((int)ks->threadid > 0) { | |
652 | kgdb_mem2hex(getthread(ks->linux_regs, | |
653 | ks->threadid)->comm, | |
654 | remcom_out_buffer, 16); | |
655 | } else { | |
656 | static char tmpstr[23 + BUF_THREAD_ID_SIZE]; | |
657 | ||
658 | sprintf(tmpstr, "shadowCPU%d", | |
659 | (int)(-ks->threadid - 2)); | |
660 | kgdb_mem2hex(tmpstr, remcom_out_buffer, strlen(tmpstr)); | |
661 | } | |
662 | break; | |
663 | } | |
664 | } | |
665 | ||
666 | /* Handle the 'H' task query packets */ | |
667 | static void gdb_cmd_task(struct kgdb_state *ks) | |
668 | { | |
669 | struct task_struct *thread; | |
670 | char *ptr; | |
671 | ||
672 | switch (remcom_in_buffer[1]) { | |
673 | case 'g': | |
674 | ptr = &remcom_in_buffer[2]; | |
675 | kgdb_hex2long(&ptr, &ks->threadid); | |
676 | thread = getthread(ks->linux_regs, ks->threadid); | |
677 | if (!thread && ks->threadid > 0) { | |
678 | error_packet(remcom_out_buffer, -EINVAL); | |
679 | break; | |
680 | } | |
681 | kgdb_usethread = thread; | |
682 | ks->kgdb_usethreadid = ks->threadid; | |
683 | strcpy(remcom_out_buffer, "OK"); | |
684 | break; | |
685 | case 'c': | |
686 | ptr = &remcom_in_buffer[2]; | |
687 | kgdb_hex2long(&ptr, &ks->threadid); | |
688 | if (!ks->threadid) { | |
689 | kgdb_contthread = NULL; | |
690 | } else { | |
691 | thread = getthread(ks->linux_regs, ks->threadid); | |
692 | if (!thread && ks->threadid > 0) { | |
693 | error_packet(remcom_out_buffer, -EINVAL); | |
694 | break; | |
695 | } | |
696 | kgdb_contthread = thread; | |
697 | } | |
698 | strcpy(remcom_out_buffer, "OK"); | |
699 | break; | |
700 | } | |
701 | } | |
702 | ||
703 | /* Handle the 'T' thread query packets */ | |
704 | static void gdb_cmd_thread(struct kgdb_state *ks) | |
705 | { | |
706 | char *ptr = &remcom_in_buffer[1]; | |
707 | struct task_struct *thread; | |
708 | ||
709 | kgdb_hex2long(&ptr, &ks->threadid); | |
710 | thread = getthread(ks->linux_regs, ks->threadid); | |
711 | if (thread) | |
712 | strcpy(remcom_out_buffer, "OK"); | |
713 | else | |
714 | error_packet(remcom_out_buffer, -EINVAL); | |
715 | } | |
716 | ||
717 | /* Handle the 'z' or 'Z' breakpoint remove or set packets */ | |
718 | static void gdb_cmd_break(struct kgdb_state *ks) | |
719 | { | |
720 | /* | |
721 | * Since GDB-5.3, it's been drafted that '0' is a software | |
722 | * breakpoint, '1' is a hardware breakpoint, so let's do that. | |
723 | */ | |
724 | char *bpt_type = &remcom_in_buffer[1]; | |
725 | char *ptr = &remcom_in_buffer[2]; | |
726 | unsigned long addr; | |
727 | unsigned long length; | |
728 | int error = 0; | |
729 | ||
730 | if (arch_kgdb_ops.set_hw_breakpoint && *bpt_type >= '1') { | |
731 | /* Unsupported */ | |
732 | if (*bpt_type > '4') | |
733 | return; | |
734 | } else { | |
735 | if (*bpt_type != '0' && *bpt_type != '1') | |
736 | /* Unsupported. */ | |
737 | return; | |
738 | } | |
739 | ||
740 | /* | |
741 | * Test if this is a hardware breakpoint, and | |
742 | * if we support it: | |
743 | */ | |
744 | if (*bpt_type == '1' && !(arch_kgdb_ops.flags & KGDB_HW_BREAKPOINT)) | |
745 | /* Unsupported. */ | |
746 | return; | |
747 | ||
748 | if (*(ptr++) != ',') { | |
749 | error_packet(remcom_out_buffer, -EINVAL); | |
750 | return; | |
751 | } | |
752 | if (!kgdb_hex2long(&ptr, &addr)) { | |
753 | error_packet(remcom_out_buffer, -EINVAL); | |
754 | return; | |
755 | } | |
756 | if (*(ptr++) != ',' || | |
757 | !kgdb_hex2long(&ptr, &length)) { | |
758 | error_packet(remcom_out_buffer, -EINVAL); | |
759 | return; | |
760 | } | |
761 | ||
762 | if (remcom_in_buffer[0] == 'Z' && *bpt_type == '0') | |
763 | error = dbg_set_sw_break(addr); | |
764 | else if (remcom_in_buffer[0] == 'z' && *bpt_type == '0') | |
765 | error = dbg_remove_sw_break(addr); | |
766 | else if (remcom_in_buffer[0] == 'Z') | |
767 | error = arch_kgdb_ops.set_hw_breakpoint(addr, | |
768 | (int)length, *bpt_type - '0'); | |
769 | else if (remcom_in_buffer[0] == 'z') | |
770 | error = arch_kgdb_ops.remove_hw_breakpoint(addr, | |
771 | (int) length, *bpt_type - '0'); | |
772 | ||
773 | if (error == 0) | |
774 | strcpy(remcom_out_buffer, "OK"); | |
775 | else | |
776 | error_packet(remcom_out_buffer, error); | |
777 | } | |
778 | ||
779 | /* Handle the 'C' signal / exception passing packets */ | |
780 | static int gdb_cmd_exception_pass(struct kgdb_state *ks) | |
781 | { | |
782 | /* C09 == pass exception | |
783 | * C15 == detach kgdb, pass exception | |
784 | */ | |
785 | if (remcom_in_buffer[1] == '0' && remcom_in_buffer[2] == '9') { | |
786 | ||
787 | ks->pass_exception = 1; | |
788 | remcom_in_buffer[0] = 'c'; | |
789 | ||
790 | } else if (remcom_in_buffer[1] == '1' && remcom_in_buffer[2] == '5') { | |
791 | ||
792 | ks->pass_exception = 1; | |
793 | remcom_in_buffer[0] = 'D'; | |
794 | dbg_remove_all_break(); | |
795 | kgdb_connected = 0; | |
796 | return 1; | |
797 | ||
798 | } else { | |
799 | gdbstub_msg_write("KGDB only knows signal 9 (pass)" | |
800 | " and 15 (pass and disconnect)\n" | |
801 | "Executing a continue without signal passing\n", 0); | |
802 | remcom_in_buffer[0] = 'c'; | |
803 | } | |
804 | ||
805 | /* Indicate fall through */ | |
806 | return -1; | |
807 | } | |
808 | ||
809 | /* | |
810 | * This function performs all gdbserial command procesing | |
811 | */ | |
812 | int gdb_serial_stub(struct kgdb_state *ks) | |
813 | { | |
814 | int error = 0; | |
815 | int tmp; | |
816 | ||
817 | /* Clear the out buffer. */ | |
818 | memset(remcom_out_buffer, 0, sizeof(remcom_out_buffer)); | |
819 | ||
820 | if (kgdb_connected) { | |
821 | unsigned char thref[8]; | |
822 | char *ptr; | |
823 | ||
824 | /* Reply to host that an exception has occurred */ | |
825 | ptr = remcom_out_buffer; | |
826 | *ptr++ = 'T'; | |
827 | ptr = pack_hex_byte(ptr, ks->signo); | |
828 | ptr += strlen(strcpy(ptr, "thread:")); | |
829 | int_to_threadref(thref, shadow_pid(current->pid)); | |
830 | ptr = pack_threadid(ptr, thref); | |
831 | *ptr++ = ';'; | |
832 | put_packet(remcom_out_buffer); | |
833 | } | |
834 | ||
835 | kgdb_usethread = kgdb_info[ks->cpu].task; | |
836 | ks->kgdb_usethreadid = shadow_pid(kgdb_info[ks->cpu].task->pid); | |
837 | ks->pass_exception = 0; | |
838 | ||
839 | while (1) { | |
840 | error = 0; | |
841 | ||
842 | /* Clear the out buffer. */ | |
843 | memset(remcom_out_buffer, 0, sizeof(remcom_out_buffer)); | |
844 | ||
845 | get_packet(remcom_in_buffer); | |
846 | ||
847 | switch (remcom_in_buffer[0]) { | |
848 | case '?': /* gdbserial status */ | |
849 | gdb_cmd_status(ks); | |
850 | break; | |
851 | case 'g': /* return the value of the CPU registers */ | |
852 | gdb_cmd_getregs(ks); | |
853 | break; | |
854 | case 'G': /* set the value of the CPU registers - return OK */ | |
855 | gdb_cmd_setregs(ks); | |
856 | break; | |
857 | case 'm': /* mAA..AA,LLLL Read LLLL bytes at address AA..AA */ | |
858 | gdb_cmd_memread(ks); | |
859 | break; | |
860 | case 'M': /* MAA..AA,LLLL: Write LLLL bytes at address AA..AA */ | |
861 | gdb_cmd_memwrite(ks); | |
862 | break; | |
863 | case 'X': /* XAA..AA,LLLL: Write LLLL bytes at address AA..AA */ | |
864 | gdb_cmd_binwrite(ks); | |
865 | break; | |
866 | /* kill or detach. KGDB should treat this like a | |
867 | * continue. | |
868 | */ | |
869 | case 'D': /* Debugger detach */ | |
870 | case 'k': /* Debugger detach via kill */ | |
871 | gdb_cmd_detachkill(ks); | |
872 | goto default_handle; | |
873 | case 'R': /* Reboot */ | |
874 | if (gdb_cmd_reboot(ks)) | |
875 | goto default_handle; | |
876 | break; | |
877 | case 'q': /* query command */ | |
878 | gdb_cmd_query(ks); | |
879 | break; | |
880 | case 'H': /* task related */ | |
881 | gdb_cmd_task(ks); | |
882 | break; | |
883 | case 'T': /* Query thread status */ | |
884 | gdb_cmd_thread(ks); | |
885 | break; | |
886 | case 'z': /* Break point remove */ | |
887 | case 'Z': /* Break point set */ | |
888 | gdb_cmd_break(ks); | |
889 | break; | |
890 | case 'C': /* Exception passing */ | |
891 | tmp = gdb_cmd_exception_pass(ks); | |
892 | if (tmp > 0) | |
893 | goto default_handle; | |
894 | if (tmp == 0) | |
895 | break; | |
896 | /* Fall through on tmp < 0 */ | |
897 | case 'c': /* Continue packet */ | |
898 | case 's': /* Single step packet */ | |
899 | if (kgdb_contthread && kgdb_contthread != current) { | |
900 | /* Can't switch threads in kgdb */ | |
901 | error_packet(remcom_out_buffer, -EINVAL); | |
902 | break; | |
903 | } | |
904 | dbg_activate_sw_breakpoints(); | |
905 | /* Fall through to default processing */ | |
906 | default: | |
907 | default_handle: | |
908 | error = kgdb_arch_handle_exception(ks->ex_vector, | |
909 | ks->signo, | |
910 | ks->err_code, | |
911 | remcom_in_buffer, | |
912 | remcom_out_buffer, | |
913 | ks->linux_regs); | |
914 | /* | |
915 | * Leave cmd processing on error, detach, | |
916 | * kill, continue, or single step. | |
917 | */ | |
918 | if (error >= 0 || remcom_in_buffer[0] == 'D' || | |
919 | remcom_in_buffer[0] == 'k') { | |
920 | error = 0; | |
921 | goto kgdb_exit; | |
922 | } | |
923 | ||
924 | } | |
925 | ||
926 | /* reply to the request */ | |
927 | put_packet(remcom_out_buffer); | |
928 | } | |
929 | ||
930 | kgdb_exit: | |
931 | if (ks->pass_exception) | |
932 | error = 1; | |
933 | return error; | |
934 | } |