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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> | |
a2531293 | 9 | * Copyright (C) 2004 Pavel Machek <pavel@ucw.cz> |
53197fc4 JW |
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> | |
f5316b4a | 33 | #include <linux/kdb.h> |
53197fc4 JW |
34 | #include <linux/reboot.h> |
35 | #include <linux/uaccess.h> | |
36 | #include <asm/cacheflush.h> | |
37 | #include <asm/unaligned.h> | |
38 | #include "debug_core.h" | |
39 | ||
40 | #define KGDB_MAX_THREAD_QUERY 17 | |
41 | ||
42 | /* Our I/O buffers. */ | |
43 | static char remcom_in_buffer[BUFMAX]; | |
44 | static char remcom_out_buffer[BUFMAX]; | |
f679c498 JW |
45 | static int gdbstub_use_prev_in_buf; |
46 | static int gdbstub_prev_in_buf_pos; | |
53197fc4 JW |
47 | |
48 | /* Storage for the registers, in GDB format. */ | |
49 | static unsigned long gdb_regs[(NUMREGBYTES + | |
50 | sizeof(unsigned long) - 1) / | |
51 | sizeof(unsigned long)]; | |
52 | ||
53 | /* | |
54 | * GDB remote protocol parser: | |
55 | */ | |
56 | ||
f5316b4a JW |
57 | #ifdef CONFIG_KGDB_KDB |
58 | static int gdbstub_read_wait(void) | |
59 | { | |
60 | int ret = -1; | |
61 | int i; | |
62 | ||
f679c498 JW |
63 | if (unlikely(gdbstub_use_prev_in_buf)) { |
64 | if (gdbstub_prev_in_buf_pos < gdbstub_use_prev_in_buf) | |
65 | return remcom_in_buffer[gdbstub_prev_in_buf_pos++]; | |
66 | else | |
67 | gdbstub_use_prev_in_buf = 0; | |
68 | } | |
69 | ||
f5316b4a JW |
70 | /* poll any additional I/O interfaces that are defined */ |
71 | while (ret < 0) | |
72 | for (i = 0; kdb_poll_funcs[i] != NULL; i++) { | |
73 | ret = kdb_poll_funcs[i](); | |
74 | if (ret > 0) | |
75 | break; | |
76 | } | |
77 | return ret; | |
78 | } | |
79 | #else | |
80 | static int gdbstub_read_wait(void) | |
81 | { | |
82 | int ret = dbg_io_ops->read_char(); | |
83 | while (ret == NO_POLL_CHAR) | |
84 | ret = dbg_io_ops->read_char(); | |
85 | return ret; | |
86 | } | |
87 | #endif | |
53197fc4 JW |
88 | /* scan for the sequence $<data>#<checksum> */ |
89 | static void get_packet(char *buffer) | |
90 | { | |
91 | unsigned char checksum; | |
92 | unsigned char xmitcsum; | |
93 | int count; | |
94 | char ch; | |
95 | ||
96 | do { | |
97 | /* | |
98 | * Spin and wait around for the start character, ignore all | |
99 | * other characters: | |
100 | */ | |
f5316b4a | 101 | while ((ch = (gdbstub_read_wait())) != '$') |
53197fc4 JW |
102 | /* nothing */; |
103 | ||
104 | kgdb_connected = 1; | |
105 | checksum = 0; | |
106 | xmitcsum = -1; | |
107 | ||
108 | count = 0; | |
109 | ||
110 | /* | |
111 | * now, read until a # or end of buffer is found: | |
112 | */ | |
113 | while (count < (BUFMAX - 1)) { | |
f5316b4a | 114 | ch = gdbstub_read_wait(); |
53197fc4 JW |
115 | if (ch == '#') |
116 | break; | |
117 | checksum = checksum + ch; | |
118 | buffer[count] = ch; | |
119 | count = count + 1; | |
120 | } | |
53197fc4 JW |
121 | |
122 | if (ch == '#') { | |
a9fa20a7 AS |
123 | xmitcsum = hex_to_bin(gdbstub_read_wait()) << 4; |
124 | xmitcsum += hex_to_bin(gdbstub_read_wait()); | |
53197fc4 JW |
125 | |
126 | if (checksum != xmitcsum) | |
127 | /* failed checksum */ | |
128 | dbg_io_ops->write_char('-'); | |
129 | else | |
130 | /* successful transfer */ | |
131 | dbg_io_ops->write_char('+'); | |
132 | if (dbg_io_ops->flush) | |
133 | dbg_io_ops->flush(); | |
134 | } | |
f679c498 | 135 | buffer[count] = 0; |
53197fc4 JW |
136 | } while (checksum != xmitcsum); |
137 | } | |
138 | ||
139 | /* | |
140 | * Send the packet in buffer. | |
141 | * Check for gdb connection if asked for. | |
142 | */ | |
143 | static void put_packet(char *buffer) | |
144 | { | |
145 | unsigned char checksum; | |
146 | int count; | |
147 | char ch; | |
148 | ||
149 | /* | |
150 | * $<packet info>#<checksum>. | |
151 | */ | |
152 | while (1) { | |
153 | dbg_io_ops->write_char('$'); | |
154 | checksum = 0; | |
155 | count = 0; | |
156 | ||
157 | while ((ch = buffer[count])) { | |
158 | dbg_io_ops->write_char(ch); | |
159 | checksum += ch; | |
160 | count++; | |
161 | } | |
162 | ||
163 | dbg_io_ops->write_char('#'); | |
164 | dbg_io_ops->write_char(hex_asc_hi(checksum)); | |
165 | dbg_io_ops->write_char(hex_asc_lo(checksum)); | |
166 | if (dbg_io_ops->flush) | |
167 | dbg_io_ops->flush(); | |
168 | ||
169 | /* Now see what we get in reply. */ | |
f5316b4a | 170 | ch = gdbstub_read_wait(); |
53197fc4 JW |
171 | |
172 | if (ch == 3) | |
f5316b4a | 173 | ch = gdbstub_read_wait(); |
53197fc4 JW |
174 | |
175 | /* If we get an ACK, we are done. */ | |
176 | if (ch == '+') | |
177 | return; | |
178 | ||
179 | /* | |
180 | * If we get the start of another packet, this means | |
181 | * that GDB is attempting to reconnect. We will NAK | |
182 | * the packet being sent, and stop trying to send this | |
183 | * packet. | |
184 | */ | |
185 | if (ch == '$') { | |
186 | dbg_io_ops->write_char('-'); | |
187 | if (dbg_io_ops->flush) | |
188 | dbg_io_ops->flush(); | |
189 | return; | |
190 | } | |
191 | } | |
192 | } | |
193 | ||
194 | static char gdbmsgbuf[BUFMAX + 1]; | |
195 | ||
196 | void gdbstub_msg_write(const char *s, int len) | |
197 | { | |
198 | char *bufptr; | |
199 | int wcount; | |
200 | int i; | |
201 | ||
a0de055c JW |
202 | if (len == 0) |
203 | len = strlen(s); | |
204 | ||
53197fc4 JW |
205 | /* 'O'utput */ |
206 | gdbmsgbuf[0] = 'O'; | |
207 | ||
208 | /* Fill and send buffers... */ | |
209 | while (len > 0) { | |
210 | bufptr = gdbmsgbuf + 1; | |
211 | ||
212 | /* Calculate how many this time */ | |
213 | if ((len << 1) > (BUFMAX - 2)) | |
214 | wcount = (BUFMAX - 2) >> 1; | |
215 | else | |
216 | wcount = len; | |
217 | ||
218 | /* Pack in hex chars */ | |
219 | for (i = 0; i < wcount; i++) | |
50e1499f | 220 | bufptr = hex_byte_pack(bufptr, s[i]); |
53197fc4 JW |
221 | *bufptr = '\0'; |
222 | ||
223 | /* Move up */ | |
224 | s += wcount; | |
225 | len -= wcount; | |
226 | ||
227 | /* Write packet */ | |
228 | put_packet(gdbmsgbuf); | |
229 | } | |
230 | } | |
231 | ||
232 | /* | |
233 | * Convert the memory pointed to by mem into hex, placing result in | |
234 | * buf. Return a pointer to the last char put in buf (null). May | |
235 | * return an error. | |
236 | */ | |
55751145 | 237 | char *kgdb_mem2hex(char *mem, char *buf, int count) |
53197fc4 JW |
238 | { |
239 | char *tmp; | |
240 | int err; | |
241 | ||
242 | /* | |
243 | * We use the upper half of buf as an intermediate buffer for the | |
244 | * raw memory copy. Hex conversion will work against this one. | |
245 | */ | |
246 | tmp = buf + count; | |
247 | ||
248 | err = probe_kernel_read(tmp, mem, count); | |
55751145 JW |
249 | if (err) |
250 | return NULL; | |
251 | while (count > 0) { | |
50e1499f | 252 | buf = hex_byte_pack(buf, *tmp); |
55751145 JW |
253 | tmp++; |
254 | count--; | |
53197fc4 | 255 | } |
55751145 | 256 | *buf = 0; |
53197fc4 | 257 | |
55751145 | 258 | return buf; |
53197fc4 JW |
259 | } |
260 | ||
261 | /* | |
262 | * Convert the hex array pointed to by buf into binary to be placed in | |
263 | * mem. Return a pointer to the character AFTER the last byte | |
264 | * written. May return an error. | |
265 | */ | |
266 | int kgdb_hex2mem(char *buf, char *mem, int count) | |
267 | { | |
268 | char *tmp_raw; | |
269 | char *tmp_hex; | |
270 | ||
271 | /* | |
272 | * We use the upper half of buf as an intermediate buffer for the | |
273 | * raw memory that is converted from hex. | |
274 | */ | |
275 | tmp_raw = buf + count * 2; | |
276 | ||
277 | tmp_hex = tmp_raw - 1; | |
278 | while (tmp_hex >= buf) { | |
279 | tmp_raw--; | |
a9fa20a7 AS |
280 | *tmp_raw = hex_to_bin(*tmp_hex--); |
281 | *tmp_raw |= hex_to_bin(*tmp_hex--) << 4; | |
53197fc4 JW |
282 | } |
283 | ||
284 | return probe_kernel_write(mem, tmp_raw, count); | |
285 | } | |
286 | ||
287 | /* | |
288 | * While we find nice hex chars, build a long_val. | |
289 | * Return number of chars processed. | |
290 | */ | |
291 | int kgdb_hex2long(char **ptr, unsigned long *long_val) | |
292 | { | |
293 | int hex_val; | |
294 | int num = 0; | |
295 | int negate = 0; | |
296 | ||
297 | *long_val = 0; | |
298 | ||
299 | if (**ptr == '-') { | |
300 | negate = 1; | |
301 | (*ptr)++; | |
302 | } | |
303 | while (**ptr) { | |
a9fa20a7 | 304 | hex_val = hex_to_bin(**ptr); |
53197fc4 JW |
305 | if (hex_val < 0) |
306 | break; | |
307 | ||
308 | *long_val = (*long_val << 4) | hex_val; | |
309 | num++; | |
310 | (*ptr)++; | |
311 | } | |
312 | ||
313 | if (negate) | |
314 | *long_val = -*long_val; | |
315 | ||
316 | return num; | |
317 | } | |
318 | ||
319 | /* | |
320 | * Copy the binary array pointed to by buf into mem. Fix $, #, and | |
321 | * 0x7d escaped with 0x7d. Return -EFAULT on failure or 0 on success. | |
322 | * The input buf is overwitten with the result to write to mem. | |
323 | */ | |
324 | static int kgdb_ebin2mem(char *buf, char *mem, int count) | |
325 | { | |
326 | int size = 0; | |
327 | char *c = buf; | |
328 | ||
329 | while (count-- > 0) { | |
330 | c[size] = *buf++; | |
331 | if (c[size] == 0x7d) | |
332 | c[size] = *buf++ ^ 0x20; | |
333 | size++; | |
334 | } | |
335 | ||
336 | return probe_kernel_write(mem, c, size); | |
337 | } | |
338 | ||
534af108 JW |
339 | #if DBG_MAX_REG_NUM > 0 |
340 | void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs) | |
341 | { | |
342 | int i; | |
343 | int idx = 0; | |
344 | char *ptr = (char *)gdb_regs; | |
345 | ||
346 | for (i = 0; i < DBG_MAX_REG_NUM; i++) { | |
347 | dbg_get_reg(i, ptr + idx, regs); | |
348 | idx += dbg_reg_def[i].size; | |
349 | } | |
350 | } | |
351 | ||
352 | void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs) | |
353 | { | |
354 | int i; | |
355 | int idx = 0; | |
356 | char *ptr = (char *)gdb_regs; | |
357 | ||
358 | for (i = 0; i < DBG_MAX_REG_NUM; i++) { | |
359 | dbg_set_reg(i, ptr + idx, regs); | |
360 | idx += dbg_reg_def[i].size; | |
361 | } | |
362 | } | |
363 | #endif /* DBG_MAX_REG_NUM > 0 */ | |
364 | ||
53197fc4 JW |
365 | /* Write memory due to an 'M' or 'X' packet. */ |
366 | static int write_mem_msg(int binary) | |
367 | { | |
368 | char *ptr = &remcom_in_buffer[1]; | |
369 | unsigned long addr; | |
370 | unsigned long length; | |
371 | int err; | |
372 | ||
373 | if (kgdb_hex2long(&ptr, &addr) > 0 && *(ptr++) == ',' && | |
374 | kgdb_hex2long(&ptr, &length) > 0 && *(ptr++) == ':') { | |
375 | if (binary) | |
376 | err = kgdb_ebin2mem(ptr, (char *)addr, length); | |
377 | else | |
378 | err = kgdb_hex2mem(ptr, (char *)addr, length); | |
379 | if (err) | |
380 | return err; | |
381 | if (CACHE_FLUSH_IS_SAFE) | |
382 | flush_icache_range(addr, addr + length); | |
383 | return 0; | |
384 | } | |
385 | ||
386 | return -EINVAL; | |
387 | } | |
388 | ||
389 | static void error_packet(char *pkt, int error) | |
390 | { | |
391 | error = -error; | |
392 | pkt[0] = 'E'; | |
393 | pkt[1] = hex_asc[(error / 10)]; | |
394 | pkt[2] = hex_asc[(error % 10)]; | |
395 | pkt[3] = '\0'; | |
396 | } | |
397 | ||
398 | /* | |
399 | * Thread ID accessors. We represent a flat TID space to GDB, where | |
400 | * the per CPU idle threads (which under Linux all have PID 0) are | |
401 | * remapped to negative TIDs. | |
402 | */ | |
403 | ||
84a0bd5b | 404 | #define BUF_THREAD_ID_SIZE 8 |
53197fc4 JW |
405 | |
406 | static char *pack_threadid(char *pkt, unsigned char *id) | |
407 | { | |
84a0bd5b JW |
408 | unsigned char *limit; |
409 | int lzero = 1; | |
410 | ||
411 | limit = id + (BUF_THREAD_ID_SIZE / 2); | |
412 | while (id < limit) { | |
413 | if (!lzero || *id != 0) { | |
50e1499f | 414 | pkt = hex_byte_pack(pkt, *id); |
84a0bd5b JW |
415 | lzero = 0; |
416 | } | |
417 | id++; | |
418 | } | |
53197fc4 | 419 | |
84a0bd5b | 420 | if (lzero) |
50e1499f | 421 | pkt = hex_byte_pack(pkt, 0); |
53197fc4 JW |
422 | |
423 | return pkt; | |
424 | } | |
425 | ||
426 | static void int_to_threadref(unsigned char *id, int value) | |
427 | { | |
84a0bd5b | 428 | put_unaligned_be32(value, id); |
53197fc4 JW |
429 | } |
430 | ||
431 | static struct task_struct *getthread(struct pt_regs *regs, int tid) | |
432 | { | |
433 | /* | |
434 | * Non-positive TIDs are remapped to the cpu shadow information | |
435 | */ | |
436 | if (tid == 0 || tid == -1) | |
437 | tid = -atomic_read(&kgdb_active) - 2; | |
438 | if (tid < -1 && tid > -NR_CPUS - 2) { | |
439 | if (kgdb_info[-tid - 2].task) | |
440 | return kgdb_info[-tid - 2].task; | |
441 | else | |
442 | return idle_task(-tid - 2); | |
443 | } | |
444 | if (tid <= 0) { | |
445 | printk(KERN_ERR "KGDB: Internal thread select error\n"); | |
446 | dump_stack(); | |
447 | return NULL; | |
448 | } | |
449 | ||
450 | /* | |
451 | * find_task_by_pid_ns() does not take the tasklist lock anymore | |
452 | * but is nicely RCU locked - hence is a pretty resilient | |
453 | * thing to use: | |
454 | */ | |
455 | return find_task_by_pid_ns(tid, &init_pid_ns); | |
456 | } | |
457 | ||
458 | ||
459 | /* | |
460 | * Remap normal tasks to their real PID, | |
461 | * CPU shadow threads are mapped to -CPU - 2 | |
462 | */ | |
463 | static inline int shadow_pid(int realpid) | |
464 | { | |
465 | if (realpid) | |
466 | return realpid; | |
467 | ||
468 | return -raw_smp_processor_id() - 2; | |
469 | } | |
470 | ||
471 | /* | |
472 | * All the functions that start with gdb_cmd are the various | |
473 | * operations to implement the handlers for the gdbserial protocol | |
474 | * where KGDB is communicating with an external debugger | |
475 | */ | |
476 | ||
477 | /* Handle the '?' status packets */ | |
478 | static void gdb_cmd_status(struct kgdb_state *ks) | |
479 | { | |
480 | /* | |
481 | * We know that this packet is only sent | |
482 | * during initial connect. So to be safe, | |
483 | * we clear out our breakpoints now in case | |
484 | * GDB is reconnecting. | |
485 | */ | |
486 | dbg_remove_all_break(); | |
487 | ||
488 | remcom_out_buffer[0] = 'S'; | |
50e1499f | 489 | hex_byte_pack(&remcom_out_buffer[1], ks->signo); |
53197fc4 JW |
490 | } |
491 | ||
55751145 | 492 | static void gdb_get_regs_helper(struct kgdb_state *ks) |
53197fc4 JW |
493 | { |
494 | struct task_struct *thread; | |
495 | void *local_debuggerinfo; | |
496 | int i; | |
497 | ||
498 | thread = kgdb_usethread; | |
499 | if (!thread) { | |
500 | thread = kgdb_info[ks->cpu].task; | |
501 | local_debuggerinfo = kgdb_info[ks->cpu].debuggerinfo; | |
502 | } else { | |
503 | local_debuggerinfo = NULL; | |
504 | for_each_online_cpu(i) { | |
505 | /* | |
506 | * Try to find the task on some other | |
507 | * or possibly this node if we do not | |
508 | * find the matching task then we try | |
509 | * to approximate the results. | |
510 | */ | |
511 | if (thread == kgdb_info[i].task) | |
512 | local_debuggerinfo = kgdb_info[i].debuggerinfo; | |
513 | } | |
514 | } | |
515 | ||
516 | /* | |
517 | * All threads that don't have debuggerinfo should be | |
518 | * in schedule() sleeping, since all other CPUs | |
519 | * are in kgdb_wait, and thus have debuggerinfo. | |
520 | */ | |
521 | if (local_debuggerinfo) { | |
522 | pt_regs_to_gdb_regs(gdb_regs, local_debuggerinfo); | |
523 | } else { | |
524 | /* | |
525 | * Pull stuff saved during switch_to; nothing | |
526 | * else is accessible (or even particularly | |
527 | * relevant). | |
528 | * | |
529 | * This should be enough for a stack trace. | |
530 | */ | |
531 | sleeping_thread_to_gdb_regs(gdb_regs, thread); | |
532 | } | |
55751145 JW |
533 | } |
534 | ||
535 | /* Handle the 'g' get registers request */ | |
536 | static void gdb_cmd_getregs(struct kgdb_state *ks) | |
537 | { | |
538 | gdb_get_regs_helper(ks); | |
53197fc4 JW |
539 | kgdb_mem2hex((char *)gdb_regs, remcom_out_buffer, NUMREGBYTES); |
540 | } | |
541 | ||
542 | /* Handle the 'G' set registers request */ | |
543 | static void gdb_cmd_setregs(struct kgdb_state *ks) | |
544 | { | |
545 | kgdb_hex2mem(&remcom_in_buffer[1], (char *)gdb_regs, NUMREGBYTES); | |
546 | ||
547 | if (kgdb_usethread && kgdb_usethread != current) { | |
548 | error_packet(remcom_out_buffer, -EINVAL); | |
549 | } else { | |
550 | gdb_regs_to_pt_regs(gdb_regs, ks->linux_regs); | |
551 | strcpy(remcom_out_buffer, "OK"); | |
552 | } | |
553 | } | |
554 | ||
555 | /* Handle the 'm' memory read bytes */ | |
556 | static void gdb_cmd_memread(struct kgdb_state *ks) | |
557 | { | |
558 | char *ptr = &remcom_in_buffer[1]; | |
559 | unsigned long length; | |
560 | unsigned long addr; | |
55751145 | 561 | char *err; |
53197fc4 JW |
562 | |
563 | if (kgdb_hex2long(&ptr, &addr) > 0 && *ptr++ == ',' && | |
564 | kgdb_hex2long(&ptr, &length) > 0) { | |
565 | err = kgdb_mem2hex((char *)addr, remcom_out_buffer, length); | |
55751145 JW |
566 | if (!err) |
567 | error_packet(remcom_out_buffer, -EINVAL); | |
53197fc4 JW |
568 | } else { |
569 | error_packet(remcom_out_buffer, -EINVAL); | |
570 | } | |
571 | } | |
572 | ||
573 | /* Handle the 'M' memory write bytes */ | |
574 | static void gdb_cmd_memwrite(struct kgdb_state *ks) | |
575 | { | |
576 | int err = write_mem_msg(0); | |
577 | ||
578 | if (err) | |
579 | error_packet(remcom_out_buffer, err); | |
580 | else | |
581 | strcpy(remcom_out_buffer, "OK"); | |
582 | } | |
583 | ||
55751145 JW |
584 | #if DBG_MAX_REG_NUM > 0 |
585 | static char *gdb_hex_reg_helper(int regnum, char *out) | |
586 | { | |
587 | int i; | |
588 | int offset = 0; | |
589 | ||
590 | for (i = 0; i < regnum; i++) | |
591 | offset += dbg_reg_def[i].size; | |
592 | return kgdb_mem2hex((char *)gdb_regs + offset, out, | |
593 | dbg_reg_def[i].size); | |
594 | } | |
595 | ||
596 | /* Handle the 'p' individual regster get */ | |
597 | static void gdb_cmd_reg_get(struct kgdb_state *ks) | |
598 | { | |
599 | unsigned long regnum; | |
600 | char *ptr = &remcom_in_buffer[1]; | |
601 | ||
602 | kgdb_hex2long(&ptr, ®num); | |
603 | if (regnum >= DBG_MAX_REG_NUM) { | |
604 | error_packet(remcom_out_buffer, -EINVAL); | |
605 | return; | |
606 | } | |
607 | gdb_get_regs_helper(ks); | |
608 | gdb_hex_reg_helper(regnum, remcom_out_buffer); | |
609 | } | |
610 | ||
611 | /* Handle the 'P' individual regster set */ | |
612 | static void gdb_cmd_reg_set(struct kgdb_state *ks) | |
613 | { | |
614 | unsigned long regnum; | |
615 | char *ptr = &remcom_in_buffer[1]; | |
6d855b1d | 616 | int i = 0; |
55751145 JW |
617 | |
618 | kgdb_hex2long(&ptr, ®num); | |
619 | if (*ptr++ != '=' || | |
620 | !(!kgdb_usethread || kgdb_usethread == current) || | |
621 | !dbg_get_reg(regnum, gdb_regs, ks->linux_regs)) { | |
622 | error_packet(remcom_out_buffer, -EINVAL); | |
623 | return; | |
624 | } | |
6d855b1d JW |
625 | memset(gdb_regs, 0, sizeof(gdb_regs)); |
626 | while (i < sizeof(gdb_regs) * 2) | |
627 | if (hex_to_bin(ptr[i]) >= 0) | |
628 | i++; | |
629 | else | |
630 | break; | |
631 | i = i / 2; | |
632 | kgdb_hex2mem(ptr, (char *)gdb_regs, i); | |
55751145 JW |
633 | dbg_set_reg(regnum, gdb_regs, ks->linux_regs); |
634 | strcpy(remcom_out_buffer, "OK"); | |
635 | } | |
636 | #endif /* DBG_MAX_REG_NUM > 0 */ | |
637 | ||
53197fc4 JW |
638 | /* Handle the 'X' memory binary write bytes */ |
639 | static void gdb_cmd_binwrite(struct kgdb_state *ks) | |
640 | { | |
641 | int err = write_mem_msg(1); | |
642 | ||
643 | if (err) | |
644 | error_packet(remcom_out_buffer, err); | |
645 | else | |
646 | strcpy(remcom_out_buffer, "OK"); | |
647 | } | |
648 | ||
649 | /* Handle the 'D' or 'k', detach or kill packets */ | |
650 | static void gdb_cmd_detachkill(struct kgdb_state *ks) | |
651 | { | |
652 | int error; | |
653 | ||
654 | /* The detach case */ | |
655 | if (remcom_in_buffer[0] == 'D') { | |
656 | error = dbg_remove_all_break(); | |
657 | if (error < 0) { | |
658 | error_packet(remcom_out_buffer, error); | |
659 | } else { | |
660 | strcpy(remcom_out_buffer, "OK"); | |
661 | kgdb_connected = 0; | |
662 | } | |
663 | put_packet(remcom_out_buffer); | |
664 | } else { | |
665 | /* | |
666 | * Assume the kill case, with no exit code checking, | |
667 | * trying to force detach the debugger: | |
668 | */ | |
669 | dbg_remove_all_break(); | |
670 | kgdb_connected = 0; | |
671 | } | |
672 | } | |
673 | ||
674 | /* Handle the 'R' reboot packets */ | |
675 | static int gdb_cmd_reboot(struct kgdb_state *ks) | |
676 | { | |
677 | /* For now, only honor R0 */ | |
678 | if (strcmp(remcom_in_buffer, "R0") == 0) { | |
679 | printk(KERN_CRIT "Executing emergency reboot\n"); | |
680 | strcpy(remcom_out_buffer, "OK"); | |
681 | put_packet(remcom_out_buffer); | |
682 | ||
683 | /* | |
684 | * Execution should not return from | |
685 | * machine_emergency_restart() | |
686 | */ | |
687 | machine_emergency_restart(); | |
688 | kgdb_connected = 0; | |
689 | ||
690 | return 1; | |
691 | } | |
692 | return 0; | |
693 | } | |
694 | ||
695 | /* Handle the 'q' query packets */ | |
696 | static void gdb_cmd_query(struct kgdb_state *ks) | |
697 | { | |
698 | struct task_struct *g; | |
699 | struct task_struct *p; | |
84a0bd5b | 700 | unsigned char thref[BUF_THREAD_ID_SIZE]; |
53197fc4 JW |
701 | char *ptr; |
702 | int i; | |
703 | int cpu; | |
704 | int finished = 0; | |
705 | ||
706 | switch (remcom_in_buffer[1]) { | |
707 | case 's': | |
708 | case 'f': | |
fb82c0ff | 709 | if (memcmp(remcom_in_buffer + 2, "ThreadInfo", 10)) |
53197fc4 | 710 | break; |
53197fc4 JW |
711 | |
712 | i = 0; | |
713 | remcom_out_buffer[0] = 'm'; | |
714 | ptr = remcom_out_buffer + 1; | |
715 | if (remcom_in_buffer[1] == 'f') { | |
716 | /* Each cpu is a shadow thread */ | |
717 | for_each_online_cpu(cpu) { | |
718 | ks->thr_query = 0; | |
719 | int_to_threadref(thref, -cpu - 2); | |
84a0bd5b | 720 | ptr = pack_threadid(ptr, thref); |
53197fc4 JW |
721 | *(ptr++) = ','; |
722 | i++; | |
723 | } | |
724 | } | |
725 | ||
726 | do_each_thread(g, p) { | |
727 | if (i >= ks->thr_query && !finished) { | |
728 | int_to_threadref(thref, p->pid); | |
84a0bd5b | 729 | ptr = pack_threadid(ptr, thref); |
53197fc4 JW |
730 | *(ptr++) = ','; |
731 | ks->thr_query++; | |
732 | if (ks->thr_query % KGDB_MAX_THREAD_QUERY == 0) | |
733 | finished = 1; | |
734 | } | |
735 | i++; | |
736 | } while_each_thread(g, p); | |
737 | ||
738 | *(--ptr) = '\0'; | |
739 | break; | |
740 | ||
741 | case 'C': | |
742 | /* Current thread id */ | |
743 | strcpy(remcom_out_buffer, "QC"); | |
744 | ks->threadid = shadow_pid(current->pid); | |
745 | int_to_threadref(thref, ks->threadid); | |
746 | pack_threadid(remcom_out_buffer + 2, thref); | |
747 | break; | |
748 | case 'T': | |
fb82c0ff | 749 | if (memcmp(remcom_in_buffer + 1, "ThreadExtraInfo,", 16)) |
53197fc4 | 750 | break; |
fb82c0ff | 751 | |
53197fc4 JW |
752 | ks->threadid = 0; |
753 | ptr = remcom_in_buffer + 17; | |
754 | kgdb_hex2long(&ptr, &ks->threadid); | |
755 | if (!getthread(ks->linux_regs, ks->threadid)) { | |
756 | error_packet(remcom_out_buffer, -EINVAL); | |
757 | break; | |
758 | } | |
759 | if ((int)ks->threadid > 0) { | |
760 | kgdb_mem2hex(getthread(ks->linux_regs, | |
761 | ks->threadid)->comm, | |
762 | remcom_out_buffer, 16); | |
763 | } else { | |
764 | static char tmpstr[23 + BUF_THREAD_ID_SIZE]; | |
765 | ||
766 | sprintf(tmpstr, "shadowCPU%d", | |
767 | (int)(-ks->threadid - 2)); | |
768 | kgdb_mem2hex(tmpstr, remcom_out_buffer, strlen(tmpstr)); | |
769 | } | |
770 | break; | |
a0de055c JW |
771 | #ifdef CONFIG_KGDB_KDB |
772 | case 'R': | |
773 | if (strncmp(remcom_in_buffer, "qRcmd,", 6) == 0) { | |
774 | int len = strlen(remcom_in_buffer + 6); | |
775 | ||
776 | if ((len % 2) != 0) { | |
777 | strcpy(remcom_out_buffer, "E01"); | |
778 | break; | |
779 | } | |
780 | kgdb_hex2mem(remcom_in_buffer + 6, | |
781 | remcom_out_buffer, len); | |
782 | len = len / 2; | |
783 | remcom_out_buffer[len++] = 0; | |
784 | ||
785 | kdb_parse(remcom_out_buffer); | |
786 | strcpy(remcom_out_buffer, "OK"); | |
787 | } | |
788 | break; | |
789 | #endif | |
53197fc4 JW |
790 | } |
791 | } | |
792 | ||
793 | /* Handle the 'H' task query packets */ | |
794 | static void gdb_cmd_task(struct kgdb_state *ks) | |
795 | { | |
796 | struct task_struct *thread; | |
797 | char *ptr; | |
798 | ||
799 | switch (remcom_in_buffer[1]) { | |
800 | case 'g': | |
801 | ptr = &remcom_in_buffer[2]; | |
802 | kgdb_hex2long(&ptr, &ks->threadid); | |
803 | thread = getthread(ks->linux_regs, ks->threadid); | |
804 | if (!thread && ks->threadid > 0) { | |
805 | error_packet(remcom_out_buffer, -EINVAL); | |
806 | break; | |
807 | } | |
808 | kgdb_usethread = thread; | |
809 | ks->kgdb_usethreadid = ks->threadid; | |
810 | strcpy(remcom_out_buffer, "OK"); | |
811 | break; | |
812 | case 'c': | |
813 | ptr = &remcom_in_buffer[2]; | |
814 | kgdb_hex2long(&ptr, &ks->threadid); | |
815 | if (!ks->threadid) { | |
816 | kgdb_contthread = NULL; | |
817 | } else { | |
818 | thread = getthread(ks->linux_regs, ks->threadid); | |
819 | if (!thread && ks->threadid > 0) { | |
820 | error_packet(remcom_out_buffer, -EINVAL); | |
821 | break; | |
822 | } | |
823 | kgdb_contthread = thread; | |
824 | } | |
825 | strcpy(remcom_out_buffer, "OK"); | |
826 | break; | |
827 | } | |
828 | } | |
829 | ||
830 | /* Handle the 'T' thread query packets */ | |
831 | static void gdb_cmd_thread(struct kgdb_state *ks) | |
832 | { | |
833 | char *ptr = &remcom_in_buffer[1]; | |
834 | struct task_struct *thread; | |
835 | ||
836 | kgdb_hex2long(&ptr, &ks->threadid); | |
837 | thread = getthread(ks->linux_regs, ks->threadid); | |
838 | if (thread) | |
839 | strcpy(remcom_out_buffer, "OK"); | |
840 | else | |
841 | error_packet(remcom_out_buffer, -EINVAL); | |
842 | } | |
843 | ||
844 | /* Handle the 'z' or 'Z' breakpoint remove or set packets */ | |
845 | static void gdb_cmd_break(struct kgdb_state *ks) | |
846 | { | |
847 | /* | |
848 | * Since GDB-5.3, it's been drafted that '0' is a software | |
849 | * breakpoint, '1' is a hardware breakpoint, so let's do that. | |
850 | */ | |
851 | char *bpt_type = &remcom_in_buffer[1]; | |
852 | char *ptr = &remcom_in_buffer[2]; | |
853 | unsigned long addr; | |
854 | unsigned long length; | |
855 | int error = 0; | |
856 | ||
857 | if (arch_kgdb_ops.set_hw_breakpoint && *bpt_type >= '1') { | |
858 | /* Unsupported */ | |
859 | if (*bpt_type > '4') | |
860 | return; | |
861 | } else { | |
862 | if (*bpt_type != '0' && *bpt_type != '1') | |
863 | /* Unsupported. */ | |
864 | return; | |
865 | } | |
866 | ||
867 | /* | |
868 | * Test if this is a hardware breakpoint, and | |
869 | * if we support it: | |
870 | */ | |
871 | if (*bpt_type == '1' && !(arch_kgdb_ops.flags & KGDB_HW_BREAKPOINT)) | |
872 | /* Unsupported. */ | |
873 | return; | |
874 | ||
875 | if (*(ptr++) != ',') { | |
876 | error_packet(remcom_out_buffer, -EINVAL); | |
877 | return; | |
878 | } | |
879 | if (!kgdb_hex2long(&ptr, &addr)) { | |
880 | error_packet(remcom_out_buffer, -EINVAL); | |
881 | return; | |
882 | } | |
883 | if (*(ptr++) != ',' || | |
884 | !kgdb_hex2long(&ptr, &length)) { | |
885 | error_packet(remcom_out_buffer, -EINVAL); | |
886 | return; | |
887 | } | |
888 | ||
889 | if (remcom_in_buffer[0] == 'Z' && *bpt_type == '0') | |
890 | error = dbg_set_sw_break(addr); | |
891 | else if (remcom_in_buffer[0] == 'z' && *bpt_type == '0') | |
892 | error = dbg_remove_sw_break(addr); | |
893 | else if (remcom_in_buffer[0] == 'Z') | |
894 | error = arch_kgdb_ops.set_hw_breakpoint(addr, | |
895 | (int)length, *bpt_type - '0'); | |
896 | else if (remcom_in_buffer[0] == 'z') | |
897 | error = arch_kgdb_ops.remove_hw_breakpoint(addr, | |
898 | (int) length, *bpt_type - '0'); | |
899 | ||
900 | if (error == 0) | |
901 | strcpy(remcom_out_buffer, "OK"); | |
902 | else | |
903 | error_packet(remcom_out_buffer, error); | |
904 | } | |
905 | ||
906 | /* Handle the 'C' signal / exception passing packets */ | |
907 | static int gdb_cmd_exception_pass(struct kgdb_state *ks) | |
908 | { | |
909 | /* C09 == pass exception | |
910 | * C15 == detach kgdb, pass exception | |
911 | */ | |
912 | if (remcom_in_buffer[1] == '0' && remcom_in_buffer[2] == '9') { | |
913 | ||
914 | ks->pass_exception = 1; | |
915 | remcom_in_buffer[0] = 'c'; | |
916 | ||
917 | } else if (remcom_in_buffer[1] == '1' && remcom_in_buffer[2] == '5') { | |
918 | ||
919 | ks->pass_exception = 1; | |
920 | remcom_in_buffer[0] = 'D'; | |
921 | dbg_remove_all_break(); | |
922 | kgdb_connected = 0; | |
923 | return 1; | |
924 | ||
925 | } else { | |
926 | gdbstub_msg_write("KGDB only knows signal 9 (pass)" | |
927 | " and 15 (pass and disconnect)\n" | |
928 | "Executing a continue without signal passing\n", 0); | |
929 | remcom_in_buffer[0] = 'c'; | |
930 | } | |
931 | ||
932 | /* Indicate fall through */ | |
933 | return -1; | |
934 | } | |
935 | ||
936 | /* | |
937 | * This function performs all gdbserial command procesing | |
938 | */ | |
939 | int gdb_serial_stub(struct kgdb_state *ks) | |
940 | { | |
941 | int error = 0; | |
942 | int tmp; | |
943 | ||
55751145 | 944 | /* Initialize comm buffer and globals. */ |
53197fc4 | 945 | memset(remcom_out_buffer, 0, sizeof(remcom_out_buffer)); |
55751145 JW |
946 | kgdb_usethread = kgdb_info[ks->cpu].task; |
947 | ks->kgdb_usethreadid = shadow_pid(kgdb_info[ks->cpu].task->pid); | |
948 | ks->pass_exception = 0; | |
53197fc4 JW |
949 | |
950 | if (kgdb_connected) { | |
84a0bd5b | 951 | unsigned char thref[BUF_THREAD_ID_SIZE]; |
53197fc4 JW |
952 | char *ptr; |
953 | ||
954 | /* Reply to host that an exception has occurred */ | |
955 | ptr = remcom_out_buffer; | |
956 | *ptr++ = 'T'; | |
50e1499f | 957 | ptr = hex_byte_pack(ptr, ks->signo); |
53197fc4 JW |
958 | ptr += strlen(strcpy(ptr, "thread:")); |
959 | int_to_threadref(thref, shadow_pid(current->pid)); | |
960 | ptr = pack_threadid(ptr, thref); | |
961 | *ptr++ = ';'; | |
962 | put_packet(remcom_out_buffer); | |
963 | } | |
964 | ||
53197fc4 JW |
965 | while (1) { |
966 | error = 0; | |
967 | ||
968 | /* Clear the out buffer. */ | |
969 | memset(remcom_out_buffer, 0, sizeof(remcom_out_buffer)); | |
970 | ||
971 | get_packet(remcom_in_buffer); | |
972 | ||
973 | switch (remcom_in_buffer[0]) { | |
974 | case '?': /* gdbserial status */ | |
975 | gdb_cmd_status(ks); | |
976 | break; | |
977 | case 'g': /* return the value of the CPU registers */ | |
978 | gdb_cmd_getregs(ks); | |
979 | break; | |
980 | case 'G': /* set the value of the CPU registers - return OK */ | |
981 | gdb_cmd_setregs(ks); | |
982 | break; | |
983 | case 'm': /* mAA..AA,LLLL Read LLLL bytes at address AA..AA */ | |
984 | gdb_cmd_memread(ks); | |
985 | break; | |
986 | case 'M': /* MAA..AA,LLLL: Write LLLL bytes at address AA..AA */ | |
987 | gdb_cmd_memwrite(ks); | |
988 | break; | |
55751145 JW |
989 | #if DBG_MAX_REG_NUM > 0 |
990 | case 'p': /* pXX Return gdb register XX (in hex) */ | |
991 | gdb_cmd_reg_get(ks); | |
992 | break; | |
993 | case 'P': /* PXX=aaaa Set gdb register XX to aaaa (in hex) */ | |
994 | gdb_cmd_reg_set(ks); | |
995 | break; | |
996 | #endif /* DBG_MAX_REG_NUM > 0 */ | |
53197fc4 JW |
997 | case 'X': /* XAA..AA,LLLL: Write LLLL bytes at address AA..AA */ |
998 | gdb_cmd_binwrite(ks); | |
999 | break; | |
1000 | /* kill or detach. KGDB should treat this like a | |
1001 | * continue. | |
1002 | */ | |
1003 | case 'D': /* Debugger detach */ | |
1004 | case 'k': /* Debugger detach via kill */ | |
1005 | gdb_cmd_detachkill(ks); | |
1006 | goto default_handle; | |
1007 | case 'R': /* Reboot */ | |
1008 | if (gdb_cmd_reboot(ks)) | |
1009 | goto default_handle; | |
1010 | break; | |
1011 | case 'q': /* query command */ | |
1012 | gdb_cmd_query(ks); | |
1013 | break; | |
1014 | case 'H': /* task related */ | |
1015 | gdb_cmd_task(ks); | |
1016 | break; | |
1017 | case 'T': /* Query thread status */ | |
1018 | gdb_cmd_thread(ks); | |
1019 | break; | |
1020 | case 'z': /* Break point remove */ | |
1021 | case 'Z': /* Break point set */ | |
1022 | gdb_cmd_break(ks); | |
1023 | break; | |
dcc78711 JW |
1024 | #ifdef CONFIG_KGDB_KDB |
1025 | case '3': /* Escape into back into kdb */ | |
1026 | if (remcom_in_buffer[1] == '\0') { | |
1027 | gdb_cmd_detachkill(ks); | |
1028 | return DBG_PASS_EVENT; | |
1029 | } | |
1030 | #endif | |
53197fc4 JW |
1031 | case 'C': /* Exception passing */ |
1032 | tmp = gdb_cmd_exception_pass(ks); | |
1033 | if (tmp > 0) | |
1034 | goto default_handle; | |
1035 | if (tmp == 0) | |
1036 | break; | |
1037 | /* Fall through on tmp < 0 */ | |
1038 | case 'c': /* Continue packet */ | |
1039 | case 's': /* Single step packet */ | |
1040 | if (kgdb_contthread && kgdb_contthread != current) { | |
1041 | /* Can't switch threads in kgdb */ | |
1042 | error_packet(remcom_out_buffer, -EINVAL); | |
1043 | break; | |
1044 | } | |
1045 | dbg_activate_sw_breakpoints(); | |
1046 | /* Fall through to default processing */ | |
1047 | default: | |
1048 | default_handle: | |
1049 | error = kgdb_arch_handle_exception(ks->ex_vector, | |
1050 | ks->signo, | |
1051 | ks->err_code, | |
1052 | remcom_in_buffer, | |
1053 | remcom_out_buffer, | |
1054 | ks->linux_regs); | |
1055 | /* | |
1056 | * Leave cmd processing on error, detach, | |
1057 | * kill, continue, or single step. | |
1058 | */ | |
1059 | if (error >= 0 || remcom_in_buffer[0] == 'D' || | |
1060 | remcom_in_buffer[0] == 'k') { | |
1061 | error = 0; | |
1062 | goto kgdb_exit; | |
1063 | } | |
1064 | ||
1065 | } | |
1066 | ||
1067 | /* reply to the request */ | |
1068 | put_packet(remcom_out_buffer); | |
1069 | } | |
1070 | ||
1071 | kgdb_exit: | |
1072 | if (ks->pass_exception) | |
1073 | error = 1; | |
1074 | return error; | |
1075 | } | |
dcc78711 JW |
1076 | |
1077 | int gdbstub_state(struct kgdb_state *ks, char *cmd) | |
1078 | { | |
1079 | int error; | |
1080 | ||
1081 | switch (cmd[0]) { | |
1082 | case 'e': | |
1083 | error = kgdb_arch_handle_exception(ks->ex_vector, | |
1084 | ks->signo, | |
1085 | ks->err_code, | |
1086 | remcom_in_buffer, | |
1087 | remcom_out_buffer, | |
1088 | ks->linux_regs); | |
1089 | return error; | |
1090 | case 's': | |
1091 | case 'c': | |
1092 | strcpy(remcom_in_buffer, cmd); | |
1093 | return 0; | |
f679c498 JW |
1094 | case '$': |
1095 | strcpy(remcom_in_buffer, cmd); | |
1096 | gdbstub_use_prev_in_buf = strlen(remcom_in_buffer); | |
1097 | gdbstub_prev_in_buf_pos = 0; | |
1098 | return 0; | |
dcc78711 JW |
1099 | } |
1100 | dbg_io_ops->write_char('+'); | |
1101 | put_packet(remcom_out_buffer); | |
1102 | return 0; | |
1103 | } | |
d57f078b DH |
1104 | |
1105 | /** | |
1106 | * gdbstub_exit - Send an exit message to GDB | |
1107 | * @status: The exit code to report. | |
1108 | */ | |
1109 | void gdbstub_exit(int status) | |
1110 | { | |
1111 | unsigned char checksum, ch, buffer[3]; | |
1112 | int loop; | |
1113 | ||
1114 | buffer[0] = 'W'; | |
1115 | buffer[1] = hex_asc_hi(status); | |
1116 | buffer[2] = hex_asc_lo(status); | |
1117 | ||
1118 | dbg_io_ops->write_char('$'); | |
1119 | checksum = 0; | |
1120 | ||
1121 | for (loop = 0; loop < 3; loop++) { | |
1122 | ch = buffer[loop]; | |
1123 | checksum += ch; | |
1124 | dbg_io_ops->write_char(ch); | |
1125 | } | |
1126 | ||
1127 | dbg_io_ops->write_char('#'); | |
1128 | dbg_io_ops->write_char(hex_asc_hi(checksum)); | |
1129 | dbg_io_ops->write_char(hex_asc_lo(checksum)); | |
1130 | ||
1131 | /* make sure the output is flushed, lest the bootloader clobber it */ | |
1132 | dbg_io_ops->flush(); | |
1133 | } |