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gdbstub: Implement gdbserial 'p' and 'P' packets
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / kernel / debug / gdbstub.c
CommitLineData
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>
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. */
43static char remcom_in_buffer[BUFMAX];
44static char remcom_out_buffer[BUFMAX];
45
46/* Storage for the registers, in GDB format. */
47static unsigned long gdb_regs[(NUMREGBYTES +
48 sizeof(unsigned long) - 1) /
49 sizeof(unsigned long)];
50
51/*
52 * GDB remote protocol parser:
53 */
54
f5316b4a
JW		 55#ifdef CONFIG_KGDB_KDB
56static int gdbstub_read_wait(void)
57{
58 int ret = -1;
59 int i;
60
61 /* poll any additional I/O interfaces that are defined */
62 while (ret < 0)
63 for (i = 0; kdb_poll_funcs[i] != NULL; i++) {
64 ret = kdb_poll_funcs[i]();
65 if (ret > 0)
66 break;
67 }
68 return ret;
69}
70#else
71static int gdbstub_read_wait(void)
72{
73 int ret = dbg_io_ops->read_char();
74 while (ret == NO_POLL_CHAR)
75 ret = dbg_io_ops->read_char();
76 return ret;
77}
78#endif
53197fc4
JW		 79/* scan for the sequence $<data>#<checksum> */
80static void get_packet(char *buffer)
81{
82 unsigned char checksum;
83 unsigned char xmitcsum;
84 int count;
85 char ch;
86
87 do {
88 /*
89 * Spin and wait around for the start character, ignore all
90 * other characters:
91 */
f5316b4a 92 while ((ch = (gdbstub_read_wait())) != '$')
53197fc4
JW		 93 /* nothing */;
94
95 kgdb_connected = 1;
96 checksum = 0;
97 xmitcsum = -1;
98
99 count = 0;
100
101 /*
102 * now, read until a # or end of buffer is found:
103 */
104 while (count < (BUFMAX - 1)) {
f5316b4a 105 ch = gdbstub_read_wait();
53197fc4
JW		 106 if (ch == '#')
107 break;
108 checksum = checksum + ch;
109 buffer[count] = ch;
110 count = count + 1;
111 }
112 buffer[count] = 0;
113
114 if (ch == '#') {
a9fa20a7
AS		 115 xmitcsum = hex_to_bin(gdbstub_read_wait()) << 4;
116 xmitcsum += hex_to_bin(gdbstub_read_wait());
53197fc4
JW		 117
118 if (checksum != xmitcsum)
119 /* failed checksum */
120 dbg_io_ops->write_char('-');
121 else
122 /* successful transfer */
123 dbg_io_ops->write_char('+');
124 if (dbg_io_ops->flush)
125 dbg_io_ops->flush();
126 }
127 } while (checksum != xmitcsum);
128}
129
130/*
131 * Send the packet in buffer.
132 * Check for gdb connection if asked for.
133 */
134static void put_packet(char *buffer)
135{
136 unsigned char checksum;
137 int count;
138 char ch;
139
140 /*
141 * $<packet info>#<checksum>.
142 */
143 while (1) {
144 dbg_io_ops->write_char('$');
145 checksum = 0;
146 count = 0;
147
148 while ((ch = buffer[count])) {
149 dbg_io_ops->write_char(ch);
150 checksum += ch;
151 count++;
152 }
153
154 dbg_io_ops->write_char('#');
155 dbg_io_ops->write_char(hex_asc_hi(checksum));
156 dbg_io_ops->write_char(hex_asc_lo(checksum));
157 if (dbg_io_ops->flush)
158 dbg_io_ops->flush();
159
160 /* Now see what we get in reply. */
f5316b4a 161 ch = gdbstub_read_wait();
53197fc4
JW		 162
163 if (ch == 3)
f5316b4a 164 ch = gdbstub_read_wait();
53197fc4
JW		 165
166 /* If we get an ACK, we are done. */
167 if (ch == '+')
168 return;
169
170 /*
171 * If we get the start of another packet, this means
172 * that GDB is attempting to reconnect. We will NAK
173 * the packet being sent, and stop trying to send this
174 * packet.
175 */
176 if (ch == '$') {
177 dbg_io_ops->write_char('-');
178 if (dbg_io_ops->flush)
179 dbg_io_ops->flush();
180 return;
181 }
182 }
183}
184
185static char gdbmsgbuf[BUFMAX + 1];
186
187void gdbstub_msg_write(const char *s, int len)
188{
189 char *bufptr;
190 int wcount;
191 int i;
192
a0de055c
JW		 193 if (len == 0)
194 len = strlen(s);
195
53197fc4
JW		 196 /* 'O'utput */
197 gdbmsgbuf[0] = 'O';
198
199 /* Fill and send buffers... */
200 while (len > 0) {
201 bufptr = gdbmsgbuf + 1;
202
203 /* Calculate how many this time */
204 if ((len << 1) > (BUFMAX - 2))
205 wcount = (BUFMAX - 2) >> 1;
206 else
207 wcount = len;
208
209 /* Pack in hex chars */
210 for (i = 0; i < wcount; i++)
211 bufptr = pack_hex_byte(bufptr, s[i]);
212 *bufptr = '\0';
213
214 /* Move up */
215 s += wcount;
216 len -= wcount;
217
218 /* Write packet */
219 put_packet(gdbmsgbuf);
220 }
221}
222
223/*
224 * Convert the memory pointed to by mem into hex, placing result in
225 * buf. Return a pointer to the last char put in buf (null). May
226 * return an error.
227 */
55751145 228char *kgdb_mem2hex(char *mem, char *buf, int count)
53197fc4
JW		 229{
230 char *tmp;
231 int err;
232
233 /*
234 * We use the upper half of buf as an intermediate buffer for the
235 * raw memory copy. Hex conversion will work against this one.
236 */
237 tmp = buf + count;
238
239 err = probe_kernel_read(tmp, mem, count);
55751145
JW		 240 if (err)
241 return NULL;
242 while (count > 0) {
243 buf = pack_hex_byte(buf, *tmp);
244 tmp++;
245 count--;
53197fc4 246 }
55751145 247 *buf = 0;
53197fc4 248
55751145 249 return buf;
53197fc4
JW		 250}
251
252/*
253 * Convert the hex array pointed to by buf into binary to be placed in
254 * mem. Return a pointer to the character AFTER the last byte
255 * written. May return an error.
256 */
257int kgdb_hex2mem(char *buf, char *mem, int count)
258{
259 char *tmp_raw;
260 char *tmp_hex;
261
262 /*
263 * We use the upper half of buf as an intermediate buffer for the
264 * raw memory that is converted from hex.
265 */
266 tmp_raw = buf + count * 2;
267
268 tmp_hex = tmp_raw - 1;
269 while (tmp_hex >= buf) {
270 tmp_raw--;
a9fa20a7
AS		 271 *tmp_raw = hex_to_bin(*tmp_hex--);
272 *tmp_raw |= hex_to_bin(*tmp_hex--) << 4;
53197fc4
JW		 273 }
274
275 return probe_kernel_write(mem, tmp_raw, count);
276}
277
278/*
279 * While we find nice hex chars, build a long_val.
280 * Return number of chars processed.
281 */
282int kgdb_hex2long(char **ptr, unsigned long *long_val)
283{
284 int hex_val;
285 int num = 0;
286 int negate = 0;
287
288 *long_val = 0;
289
290 if (**ptr == '-') {
291 negate = 1;
292 (*ptr)++;
293 }
294 while (**ptr) {
a9fa20a7 295 hex_val = hex_to_bin(**ptr);
53197fc4
JW		 296 if (hex_val < 0)
297 break;
298
299 *long_val = (*long_val << 4) | hex_val;
300 num++;
301 (*ptr)++;
302 }
303
304 if (negate)
305 *long_val = -*long_val;
306
307 return num;
308}
309
310/*
311 * Copy the binary array pointed to by buf into mem. Fix $, #, and
312 * 0x7d escaped with 0x7d. Return -EFAULT on failure or 0 on success.
313 * The input buf is overwitten with the result to write to mem.
314 */
315static int kgdb_ebin2mem(char *buf, char *mem, int count)
316{
317 int size = 0;
318 char *c = buf;
319
320 while (count-- > 0) {
321 c[size] = *buf++;
322 if (c[size] == 0x7d)
323 c[size] = *buf++ ^ 0x20;
324 size++;
325 }
326
327 return probe_kernel_write(mem, c, size);
328}
329
534af108
JW		 330#if DBG_MAX_REG_NUM > 0
331void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs)
332{
333 int i;
334 int idx = 0;
335 char *ptr = (char *)gdb_regs;
336
337 for (i = 0; i < DBG_MAX_REG_NUM; i++) {
338 dbg_get_reg(i, ptr + idx, regs);
339 idx += dbg_reg_def[i].size;
340 }
341}
342
343void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs)
344{
345 int i;
346 int idx = 0;
347 char *ptr = (char *)gdb_regs;
348
349 for (i = 0; i < DBG_MAX_REG_NUM; i++) {
350 dbg_set_reg(i, ptr + idx, regs);
351 idx += dbg_reg_def[i].size;
352 }
353}
354#endif /* DBG_MAX_REG_NUM > 0 */
355
53197fc4
JW		 356/* Write memory due to an 'M' or 'X' packet. */
357static int write_mem_msg(int binary)
358{
359 char *ptr = &remcom_in_buffer[1];
360 unsigned long addr;
361 unsigned long length;
362 int err;
363
364 if (kgdb_hex2long(&ptr, &addr) > 0 && *(ptr++) == ',' &&
365 kgdb_hex2long(&ptr, &length) > 0 && *(ptr++) == ':') {
366 if (binary)
367 err = kgdb_ebin2mem(ptr, (char *)addr, length);
368 else
369 err = kgdb_hex2mem(ptr, (char *)addr, length);
370 if (err)
371 return err;
372 if (CACHE_FLUSH_IS_SAFE)
373 flush_icache_range(addr, addr + length);
374 return 0;
375 }
376
377 return -EINVAL;
378}
379
380static void error_packet(char *pkt, int error)
381{
382 error = -error;
383 pkt[0] = 'E';
384 pkt[1] = hex_asc[(error / 10)];
385 pkt[2] = hex_asc[(error % 10)];
386 pkt[3] = '\0';
387}
388
389/*
390 * Thread ID accessors. We represent a flat TID space to GDB, where
391 * the per CPU idle threads (which under Linux all have PID 0) are
392 * remapped to negative TIDs.
393 */
394
84a0bd5b 395#define BUF_THREAD_ID_SIZE 8
53197fc4
JW		 396
397static char *pack_threadid(char *pkt, unsigned char *id)
398{
84a0bd5b
JW		 399 unsigned char *limit;
400 int lzero = 1;
401
402 limit = id + (BUF_THREAD_ID_SIZE / 2);
403 while (id < limit) {
404 if (!lzero || *id != 0) {
405 pkt = pack_hex_byte(pkt, *id);
406 lzero = 0;
407 }
408 id++;
409 }
53197fc4 410
84a0bd5b
JW		 411 if (lzero)
412 pkt = pack_hex_byte(pkt, 0);
53197fc4
JW		 413
414 return pkt;
415}
416
417static void int_to_threadref(unsigned char *id, int value)
418{
84a0bd5b 419 put_unaligned_be32(value, id);
53197fc4
JW		 420}
421
422static struct task_struct *getthread(struct pt_regs *regs, int tid)
423{
424 /*
425 * Non-positive TIDs are remapped to the cpu shadow information
426 */
427 if (tid == 0 || tid == -1)
428 tid = -atomic_read(&kgdb_active) - 2;
429 if (tid < -1 && tid > -NR_CPUS - 2) {
430 if (kgdb_info[-tid - 2].task)
431 return kgdb_info[-tid - 2].task;
432 else
433 return idle_task(-tid - 2);
434 }
435 if (tid <= 0) {
436 printk(KERN_ERR "KGDB: Internal thread select error\n");
437 dump_stack();
438 return NULL;
439 }
440
441 /*
442 * find_task_by_pid_ns() does not take the tasklist lock anymore
443 * but is nicely RCU locked - hence is a pretty resilient
444 * thing to use:
445 */
446 return find_task_by_pid_ns(tid, &init_pid_ns);
447}
448
449
450/*
451 * Remap normal tasks to their real PID,
452 * CPU shadow threads are mapped to -CPU - 2
453 */
454static inline int shadow_pid(int realpid)
455{
456 if (realpid)
457 return realpid;
458
459 return -raw_smp_processor_id() - 2;
460}
461
462/*
463 * All the functions that start with gdb_cmd are the various
464 * operations to implement the handlers for the gdbserial protocol
465 * where KGDB is communicating with an external debugger
466 */
467
468/* Handle the '?' status packets */
469static void gdb_cmd_status(struct kgdb_state *ks)
470{
471 /*
472 * We know that this packet is only sent
473 * during initial connect. So to be safe,
474 * we clear out our breakpoints now in case
475 * GDB is reconnecting.
476 */
477 dbg_remove_all_break();
478
479 remcom_out_buffer[0] = 'S';
480 pack_hex_byte(&remcom_out_buffer[1], ks->signo);
481}
482
55751145 483static void gdb_get_regs_helper(struct kgdb_state *ks)
53197fc4
JW		 484{
485 struct task_struct *thread;
486 void *local_debuggerinfo;
487 int i;
488
489 thread = kgdb_usethread;
490 if (!thread) {
491 thread = kgdb_info[ks->cpu].task;
492 local_debuggerinfo = kgdb_info[ks->cpu].debuggerinfo;
493 } else {
494 local_debuggerinfo = NULL;
495 for_each_online_cpu(i) {
496 /*
497 * Try to find the task on some other
498 * or possibly this node if we do not
499 * find the matching task then we try
500 * to approximate the results.
501 */
502 if (thread == kgdb_info[i].task)
503 local_debuggerinfo = kgdb_info[i].debuggerinfo;
504 }
505 }
506
507 /*
508 * All threads that don't have debuggerinfo should be
509 * in schedule() sleeping, since all other CPUs
510 * are in kgdb_wait, and thus have debuggerinfo.
511 */
512 if (local_debuggerinfo) {
513 pt_regs_to_gdb_regs(gdb_regs, local_debuggerinfo);
514 } else {
515 /*
516 * Pull stuff saved during switch_to; nothing
517 * else is accessible (or even particularly
518 * relevant).
519 *
520 * This should be enough for a stack trace.
521 */
522 sleeping_thread_to_gdb_regs(gdb_regs, thread);
523 }
55751145
JW		 524}
525
526/* Handle the 'g' get registers request */
527static void gdb_cmd_getregs(struct kgdb_state *ks)
528{
529 gdb_get_regs_helper(ks);
53197fc4
JW		 530 kgdb_mem2hex((char *)gdb_regs, remcom_out_buffer, NUMREGBYTES);
531}
532
533/* Handle the 'G' set registers request */
534static void gdb_cmd_setregs(struct kgdb_state *ks)
535{
536 kgdb_hex2mem(&remcom_in_buffer[1], (char *)gdb_regs, NUMREGBYTES);
537
538 if (kgdb_usethread && kgdb_usethread != current) {
539 error_packet(remcom_out_buffer, -EINVAL);
540 } else {
541 gdb_regs_to_pt_regs(gdb_regs, ks->linux_regs);
542 strcpy(remcom_out_buffer, "OK");
543 }
544}
545
546/* Handle the 'm' memory read bytes */
547static void gdb_cmd_memread(struct kgdb_state *ks)
548{
549 char *ptr = &remcom_in_buffer[1];
550 unsigned long length;
551 unsigned long addr;
55751145 552 char *err;
53197fc4
JW		 553
554 if (kgdb_hex2long(&ptr, &addr) > 0 && *ptr++ == ',' &&
555 kgdb_hex2long(&ptr, &length) > 0) {
556 err = kgdb_mem2hex((char *)addr, remcom_out_buffer, length);
55751145
JW		 557 if (!err)
558 error_packet(remcom_out_buffer, -EINVAL);
53197fc4
JW		 559 } else {
560 error_packet(remcom_out_buffer, -EINVAL);
561 }
562}
563
564/* Handle the 'M' memory write bytes */
565static void gdb_cmd_memwrite(struct kgdb_state *ks)
566{
567 int err = write_mem_msg(0);
568
569 if (err)
570 error_packet(remcom_out_buffer, err);
571 else
572 strcpy(remcom_out_buffer, "OK");
573}
574
55751145
JW		 575#if DBG_MAX_REG_NUM > 0
576static char *gdb_hex_reg_helper(int regnum, char *out)
577{
578 int i;
579 int offset = 0;
580
581 for (i = 0; i < regnum; i++)
582 offset += dbg_reg_def[i].size;
583 return kgdb_mem2hex((char *)gdb_regs + offset, out,
584 dbg_reg_def[i].size);
585}
586
587/* Handle the 'p' individual regster get */
588static void gdb_cmd_reg_get(struct kgdb_state *ks)
589{
590 unsigned long regnum;
591 char *ptr = &remcom_in_buffer[1];
592
593 kgdb_hex2long(&ptr, &regnum);
594 if (regnum >= DBG_MAX_REG_NUM) {
595 error_packet(remcom_out_buffer, -EINVAL);
596 return;
597 }
598 gdb_get_regs_helper(ks);
599 gdb_hex_reg_helper(regnum, remcom_out_buffer);
600}
601
602/* Handle the 'P' individual regster set */
603static void gdb_cmd_reg_set(struct kgdb_state *ks)
604{
605 unsigned long regnum;
606 char *ptr = &remcom_in_buffer[1];
607
608 kgdb_hex2long(&ptr, &regnum);
609 if (*ptr++ != '=' ||
610 !(!kgdb_usethread || kgdb_usethread == current) ||
611 !dbg_get_reg(regnum, gdb_regs, ks->linux_regs)) {
612 error_packet(remcom_out_buffer, -EINVAL);
613 return;
614 }
615 kgdb_hex2mem(ptr, (char *)gdb_regs, dbg_reg_def[regnum].size);
616 dbg_set_reg(regnum, gdb_regs, ks->linux_regs);
617 strcpy(remcom_out_buffer, "OK");
618}
619#endif /* DBG_MAX_REG_NUM > 0 */
620
53197fc4
JW		 621/* Handle the 'X' memory binary write bytes */
622static void gdb_cmd_binwrite(struct kgdb_state *ks)
623{
624 int err = write_mem_msg(1);
625
626 if (err)
627 error_packet(remcom_out_buffer, err);
628 else
629 strcpy(remcom_out_buffer, "OK");
630}
631
632/* Handle the 'D' or 'k', detach or kill packets */
633static void gdb_cmd_detachkill(struct kgdb_state *ks)
634{
635 int error;
636
637 /* The detach case */
638 if (remcom_in_buffer[0] == 'D') {
639 error = dbg_remove_all_break();
640 if (error < 0) {
641 error_packet(remcom_out_buffer, error);
642 } else {
643 strcpy(remcom_out_buffer, "OK");
644 kgdb_connected = 0;
645 }
646 put_packet(remcom_out_buffer);
647 } else {
648 /*
649 * Assume the kill case, with no exit code checking,
650 * trying to force detach the debugger:
651 */
652 dbg_remove_all_break();
653 kgdb_connected = 0;
654 }
655}
656
657/* Handle the 'R' reboot packets */
658static int gdb_cmd_reboot(struct kgdb_state *ks)
659{
660 /* For now, only honor R0 */
661 if (strcmp(remcom_in_buffer, "R0") == 0) {
662 printk(KERN_CRIT "Executing emergency reboot\n");
663 strcpy(remcom_out_buffer, "OK");
664 put_packet(remcom_out_buffer);
665
666 /*
667 * Execution should not return from
668 * machine_emergency_restart()
669 */
670 machine_emergency_restart();
671 kgdb_connected = 0;
672
673 return 1;
674 }
675 return 0;
676}
677
678/* Handle the 'q' query packets */
679static void gdb_cmd_query(struct kgdb_state *ks)
680{
681 struct task_struct *g;
682 struct task_struct *p;
84a0bd5b 683 unsigned char thref[BUF_THREAD_ID_SIZE];
53197fc4
JW		 684 char *ptr;
685 int i;
686 int cpu;
687 int finished = 0;
688
689 switch (remcom_in_buffer[1]) {
690 case 's':
691 case 'f':
fb82c0ff 692 if (memcmp(remcom_in_buffer + 2, "ThreadInfo", 10))
53197fc4 693 break;
53197fc4
JW		 694
695 i = 0;
696 remcom_out_buffer[0] = 'm';
697 ptr = remcom_out_buffer + 1;
698 if (remcom_in_buffer[1] == 'f') {
699 /* Each cpu is a shadow thread */
700 for_each_online_cpu(cpu) {
701 ks->thr_query = 0;
702 int_to_threadref(thref, -cpu - 2);
84a0bd5b 703 ptr = pack_threadid(ptr, thref);
53197fc4
JW		 704 *(ptr++) = ',';
705 i++;
706 }
707 }
708
709 do_each_thread(g, p) {
710 if (i >= ks->thr_query && !finished) {
711 int_to_threadref(thref, p->pid);
84a0bd5b 712 ptr = pack_threadid(ptr, thref);
53197fc4
JW		 713 *(ptr++) = ',';
714 ks->thr_query++;
715 if (ks->thr_query % KGDB_MAX_THREAD_QUERY == 0)
716 finished = 1;
717 }
718 i++;
719 } while_each_thread(g, p);
720
721 *(--ptr) = '\0';
722 break;
723
724 case 'C':
725 /* Current thread id */
726 strcpy(remcom_out_buffer, "QC");
727 ks->threadid = shadow_pid(current->pid);
728 int_to_threadref(thref, ks->threadid);
729 pack_threadid(remcom_out_buffer + 2, thref);
730 break;
731 case 'T':
fb82c0ff 732 if (memcmp(remcom_in_buffer + 1, "ThreadExtraInfo,", 16))
53197fc4 733 break;
fb82c0ff 734
53197fc4
JW		 735 ks->threadid = 0;
736 ptr = remcom_in_buffer + 17;
737 kgdb_hex2long(&ptr, &ks->threadid);
738 if (!getthread(ks->linux_regs, ks->threadid)) {
739 error_packet(remcom_out_buffer, -EINVAL);
740 break;
741 }
742 if ((int)ks->threadid > 0) {
743 kgdb_mem2hex(getthread(ks->linux_regs,
744 ks->threadid)->comm,
745 remcom_out_buffer, 16);
746 } else {
747 static char tmpstr[23 + BUF_THREAD_ID_SIZE];
748
749 sprintf(tmpstr, "shadowCPU%d",
750 (int)(-ks->threadid - 2));
751 kgdb_mem2hex(tmpstr, remcom_out_buffer, strlen(tmpstr));
752 }
753 break;
a0de055c
JW		 754#ifdef CONFIG_KGDB_KDB
755 case 'R':
756 if (strncmp(remcom_in_buffer, "qRcmd,", 6) == 0) {
757 int len = strlen(remcom_in_buffer + 6);
758
759 if ((len % 2) != 0) {
760 strcpy(remcom_out_buffer, "E01");
761 break;
762 }
763 kgdb_hex2mem(remcom_in_buffer + 6,
764 remcom_out_buffer, len);
765 len = len / 2;
766 remcom_out_buffer[len++] = 0;
767
768 kdb_parse(remcom_out_buffer);
769 strcpy(remcom_out_buffer, "OK");
770 }
771 break;
772#endif
53197fc4
JW		 773 }
774}
775
776/* Handle the 'H' task query packets */
777static void gdb_cmd_task(struct kgdb_state *ks)
778{
779 struct task_struct *thread;
780 char *ptr;
781
782 switch (remcom_in_buffer[1]) {
783 case 'g':
784 ptr = &remcom_in_buffer[2];
785 kgdb_hex2long(&ptr, &ks->threadid);
786 thread = getthread(ks->linux_regs, ks->threadid);
787 if (!thread && ks->threadid > 0) {
788 error_packet(remcom_out_buffer, -EINVAL);
789 break;
790 }
791 kgdb_usethread = thread;
792 ks->kgdb_usethreadid = ks->threadid;
793 strcpy(remcom_out_buffer, "OK");
794 break;
795 case 'c':
796 ptr = &remcom_in_buffer[2];
797 kgdb_hex2long(&ptr, &ks->threadid);
798 if (!ks->threadid) {
799 kgdb_contthread = NULL;
800 } else {
801 thread = getthread(ks->linux_regs, ks->threadid);
802 if (!thread && ks->threadid > 0) {
803 error_packet(remcom_out_buffer, -EINVAL);
804 break;
805 }
806 kgdb_contthread = thread;
807 }
808 strcpy(remcom_out_buffer, "OK");
809 break;
810 }
811}
812
813/* Handle the 'T' thread query packets */
814static void gdb_cmd_thread(struct kgdb_state *ks)
815{
816 char *ptr = &remcom_in_buffer[1];
817 struct task_struct *thread;
818
819 kgdb_hex2long(&ptr, &ks->threadid);
820 thread = getthread(ks->linux_regs, ks->threadid);
821 if (thread)
822 strcpy(remcom_out_buffer, "OK");
823 else
824 error_packet(remcom_out_buffer, -EINVAL);
825}
826
827/* Handle the 'z' or 'Z' breakpoint remove or set packets */
828static void gdb_cmd_break(struct kgdb_state *ks)
829{
830 /*
831 * Since GDB-5.3, it's been drafted that '0' is a software
832 * breakpoint, '1' is a hardware breakpoint, so let's do that.
833 */
834 char *bpt_type = &remcom_in_buffer[1];
835 char *ptr = &remcom_in_buffer[2];
836 unsigned long addr;
837 unsigned long length;
838 int error = 0;
839
840 if (arch_kgdb_ops.set_hw_breakpoint && *bpt_type >= '1') {
841 /* Unsupported */
842 if (*bpt_type > '4')
843 return;
844 } else {
845 if (*bpt_type != '0' && *bpt_type != '1')
846 /* Unsupported. */
847 return;
848 }
849
850 /*
851 * Test if this is a hardware breakpoint, and
852 * if we support it:
853 */
854 if (*bpt_type == '1' && !(arch_kgdb_ops.flags & KGDB_HW_BREAKPOINT))
855 /* Unsupported. */
856 return;
857
858 if (*(ptr++) != ',') {
859 error_packet(remcom_out_buffer, -EINVAL);
860 return;
861 }
862 if (!kgdb_hex2long(&ptr, &addr)) {
863 error_packet(remcom_out_buffer, -EINVAL);
864 return;
865 }
866 if (*(ptr++) != ',' ||
867 !kgdb_hex2long(&ptr, &length)) {
868 error_packet(remcom_out_buffer, -EINVAL);
869 return;
870 }
871
872 if (remcom_in_buffer[0] == 'Z' && *bpt_type == '0')
873 error = dbg_set_sw_break(addr);
874 else if (remcom_in_buffer[0] == 'z' && *bpt_type == '0')
875 error = dbg_remove_sw_break(addr);
876 else if (remcom_in_buffer[0] == 'Z')
877 error = arch_kgdb_ops.set_hw_breakpoint(addr,
878 (int)length, *bpt_type - '0');
879 else if (remcom_in_buffer[0] == 'z')
880 error = arch_kgdb_ops.remove_hw_breakpoint(addr,
881 (int) length, *bpt_type - '0');
882
883 if (error == 0)
884 strcpy(remcom_out_buffer, "OK");
885 else
886 error_packet(remcom_out_buffer, error);
887}
888
889/* Handle the 'C' signal / exception passing packets */
890static int gdb_cmd_exception_pass(struct kgdb_state *ks)
891{
892 /* C09 == pass exception
893 * C15 == detach kgdb, pass exception
894 */
895 if (remcom_in_buffer[1] == '0' && remcom_in_buffer[2] == '9') {
896
897 ks->pass_exception = 1;
898 remcom_in_buffer[0] = 'c';
899
900 } else if (remcom_in_buffer[1] == '1' && remcom_in_buffer[2] == '5') {
901
902 ks->pass_exception = 1;
903 remcom_in_buffer[0] = 'D';
904 dbg_remove_all_break();
905 kgdb_connected = 0;
906 return 1;
907
908 } else {
909 gdbstub_msg_write("KGDB only knows signal 9 (pass)"
910 " and 15 (pass and disconnect)\n"
911 "Executing a continue without signal passing\n", 0);
912 remcom_in_buffer[0] = 'c';
913 }
914
915 /* Indicate fall through */
916 return -1;
917}
918
919/*
920 * This function performs all gdbserial command procesing
921 */
922int gdb_serial_stub(struct kgdb_state *ks)
923{
924 int error = 0;
925 int tmp;
926
55751145 927 /* Initialize comm buffer and globals. */
53197fc4 928 memset(remcom_out_buffer, 0, sizeof(remcom_out_buffer));
55751145
JW		 929 kgdb_usethread = kgdb_info[ks->cpu].task;
930 ks->kgdb_usethreadid = shadow_pid(kgdb_info[ks->cpu].task->pid);
931 ks->pass_exception = 0;
53197fc4
JW		 932
933 if (kgdb_connected) {
84a0bd5b 934 unsigned char thref[BUF_THREAD_ID_SIZE];
53197fc4
JW		 935 char *ptr;
936
937 /* Reply to host that an exception has occurred */
938 ptr = remcom_out_buffer;
939 *ptr++ = 'T';
940 ptr = pack_hex_byte(ptr, ks->signo);
941 ptr += strlen(strcpy(ptr, "thread:"));
942 int_to_threadref(thref, shadow_pid(current->pid));
943 ptr = pack_threadid(ptr, thref);
944 *ptr++ = ';';
945 put_packet(remcom_out_buffer);
946 }
947
53197fc4
JW		 948 while (1) {
949 error = 0;
950
951 /* Clear the out buffer. */
952 memset(remcom_out_buffer, 0, sizeof(remcom_out_buffer));
953
954 get_packet(remcom_in_buffer);
955
956 switch (remcom_in_buffer[0]) {
957 case '?': /* gdbserial status */
958 gdb_cmd_status(ks);
959 break;
960 case 'g': /* return the value of the CPU registers */
961 gdb_cmd_getregs(ks);
962 break;
963 case 'G': /* set the value of the CPU registers - return OK */
964 gdb_cmd_setregs(ks);
965 break;
966 case 'm': /* mAA..AA,LLLL Read LLLL bytes at address AA..AA */
967 gdb_cmd_memread(ks);
968 break;
969 case 'M': /* MAA..AA,LLLL: Write LLLL bytes at address AA..AA */
970 gdb_cmd_memwrite(ks);
971 break;
55751145
JW		 972#if DBG_MAX_REG_NUM > 0
973 case 'p': /* pXX Return gdb register XX (in hex) */
974 gdb_cmd_reg_get(ks);
975 break;
976 case 'P': /* PXX=aaaa Set gdb register XX to aaaa (in hex) */
977 gdb_cmd_reg_set(ks);
978 break;
979#endif /* DBG_MAX_REG_NUM > 0 */
53197fc4
JW		 980 case 'X': /* XAA..AA,LLLL: Write LLLL bytes at address AA..AA */
981 gdb_cmd_binwrite(ks);
982 break;
983 /* kill or detach. KGDB should treat this like a
984 * continue.
985 */
986 case 'D': /* Debugger detach */
987 case 'k': /* Debugger detach via kill */
988 gdb_cmd_detachkill(ks);
989 goto default_handle;
990 case 'R': /* Reboot */
991 if (gdb_cmd_reboot(ks))
992 goto default_handle;
993 break;
994 case 'q': /* query command */
995 gdb_cmd_query(ks);
996 break;
997 case 'H': /* task related */
998 gdb_cmd_task(ks);
999 break;
1000 case 'T': /* Query thread status */
1001 gdb_cmd_thread(ks);
1002 break;
1003 case 'z': /* Break point remove */
1004 case 'Z': /* Break point set */
1005 gdb_cmd_break(ks);
1006 break;
dcc78711
JW		 1007#ifdef CONFIG_KGDB_KDB
1008 case '3': /* Escape into back into kdb */
1009 if (remcom_in_buffer[1] == '\0') {
1010 gdb_cmd_detachkill(ks);
1011 return DBG_PASS_EVENT;
1012 }
1013#endif
53197fc4
JW		 1014 case 'C': /* Exception passing */
1015 tmp = gdb_cmd_exception_pass(ks);
1016 if (tmp > 0)
1017 goto default_handle;
1018 if (tmp == 0)
1019 break;
1020 /* Fall through on tmp < 0 */
1021 case 'c': /* Continue packet */
1022 case 's': /* Single step packet */
1023 if (kgdb_contthread && kgdb_contthread != current) {
1024 /* Can't switch threads in kgdb */
1025 error_packet(remcom_out_buffer, -EINVAL);
1026 break;
1027 }
1028 dbg_activate_sw_breakpoints();
1029 /* Fall through to default processing */
1030 default:
1031default_handle:
1032 error = kgdb_arch_handle_exception(ks->ex_vector,
1033 ks->signo,
1034 ks->err_code,
1035 remcom_in_buffer,
1036 remcom_out_buffer,
1037 ks->linux_regs);
1038 /*
1039 * Leave cmd processing on error, detach,
1040 * kill, continue, or single step.
1041 */
1042 if (error >= 0 || remcom_in_buffer[0] == 'D' ||
1043 remcom_in_buffer[0] == 'k') {
1044 error = 0;
1045 goto kgdb_exit;
1046 }
1047
1048 }
1049
1050 /* reply to the request */
1051 put_packet(remcom_out_buffer);
1052 }
1053
1054kgdb_exit:
1055 if (ks->pass_exception)
1056 error = 1;
1057 return error;
1058}
dcc78711
JW		 1059
1060int gdbstub_state(struct kgdb_state *ks, char *cmd)
1061{
1062 int error;
1063
1064 switch (cmd[0]) {
1065 case 'e':
1066 error = kgdb_arch_handle_exception(ks->ex_vector,
1067 ks->signo,
1068 ks->err_code,
1069 remcom_in_buffer,
1070 remcom_out_buffer,
1071 ks->linux_regs);
1072 return error;
1073 case 's':
1074 case 'c':
1075 strcpy(remcom_in_buffer, cmd);
1076 return 0;
1077 case '?':
1078 gdb_cmd_status(ks);
1079 break;
1080 case '\0':
1081 strcpy(remcom_out_buffer, "");
1082 break;
1083 }
1084 dbg_io_ops->write_char('+');
1085 put_packet(remcom_out_buffer);
1086 return 0;
1087}
kernel source for telekom puls (alcatel/mediatek)