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kgdb,arm: Individual register get/set for arm
[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 */
228int kgdb_mem2hex(char *mem, char *buf, int count)
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);
240 if (!err) {
241 while (count > 0) {
242 buf = pack_hex_byte(buf, *tmp);
243 tmp++;
244 count--;
245 }
246
247 *buf = 0;
248 }
249
250 return err;
251}
252
253/*
254 * Convert the hex array pointed to by buf into binary to be placed in
255 * mem. Return a pointer to the character AFTER the last byte
256 * written. May return an error.
257 */
258int kgdb_hex2mem(char *buf, char *mem, int count)
259{
260 char *tmp_raw;
261 char *tmp_hex;
262
263 /*
264 * We use the upper half of buf as an intermediate buffer for the
265 * raw memory that is converted from hex.
266 */
267 tmp_raw = buf + count * 2;
268
269 tmp_hex = tmp_raw - 1;
270 while (tmp_hex >= buf) {
271 tmp_raw--;
a9fa20a7
AS		 272 *tmp_raw = hex_to_bin(*tmp_hex--);
273 *tmp_raw |= hex_to_bin(*tmp_hex--) << 4;
53197fc4
JW		 274 }
275
276 return probe_kernel_write(mem, tmp_raw, count);
277}
278
279/*
280 * While we find nice hex chars, build a long_val.
281 * Return number of chars processed.
282 */
283int kgdb_hex2long(char **ptr, unsigned long *long_val)
284{
285 int hex_val;
286 int num = 0;
287 int negate = 0;
288
289 *long_val = 0;
290
291 if (**ptr == '-') {
292 negate = 1;
293 (*ptr)++;
294 }
295 while (**ptr) {
a9fa20a7 296 hex_val = hex_to_bin(**ptr);
53197fc4
JW		 297 if (hex_val < 0)
298 break;
299
300 *long_val = (*long_val << 4) | hex_val;
301 num++;
302 (*ptr)++;
303 }
304
305 if (negate)
306 *long_val = -*long_val;
307
308 return num;
309}
310
311/*
312 * Copy the binary array pointed to by buf into mem. Fix $, #, and
313 * 0x7d escaped with 0x7d. Return -EFAULT on failure or 0 on success.
314 * The input buf is overwitten with the result to write to mem.
315 */
316static int kgdb_ebin2mem(char *buf, char *mem, int count)
317{
318 int size = 0;
319 char *c = buf;
320
321 while (count-- > 0) {
322 c[size] = *buf++;
323 if (c[size] == 0x7d)
324 c[size] = *buf++ ^ 0x20;
325 size++;
326 }
327
328 return probe_kernel_write(mem, c, size);
329}
330
534af108
JW		 331#if DBG_MAX_REG_NUM > 0
332void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs)
333{
334 int i;
335 int idx = 0;
336 char *ptr = (char *)gdb_regs;
337
338 for (i = 0; i < DBG_MAX_REG_NUM; i++) {
339 dbg_get_reg(i, ptr + idx, regs);
340 idx += dbg_reg_def[i].size;
341 }
342}
343
344void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs)
345{
346 int i;
347 int idx = 0;
348 char *ptr = (char *)gdb_regs;
349
350 for (i = 0; i < DBG_MAX_REG_NUM; i++) {
351 dbg_set_reg(i, ptr + idx, regs);
352 idx += dbg_reg_def[i].size;
353 }
354}
355#endif /* DBG_MAX_REG_NUM > 0 */
356
53197fc4
JW		 357/* Write memory due to an 'M' or 'X' packet. */
358static int write_mem_msg(int binary)
359{
360 char *ptr = &remcom_in_buffer[1];
361 unsigned long addr;
362 unsigned long length;
363 int err;
364
365 if (kgdb_hex2long(&ptr, &addr) > 0 && *(ptr++) == ',' &&
366 kgdb_hex2long(&ptr, &length) > 0 && *(ptr++) == ':') {
367 if (binary)
368 err = kgdb_ebin2mem(ptr, (char *)addr, length);
369 else
370 err = kgdb_hex2mem(ptr, (char *)addr, length);
371 if (err)
372 return err;
373 if (CACHE_FLUSH_IS_SAFE)
374 flush_icache_range(addr, addr + length);
375 return 0;
376 }
377
378 return -EINVAL;
379}
380
381static void error_packet(char *pkt, int error)
382{
383 error = -error;
384 pkt[0] = 'E';
385 pkt[1] = hex_asc[(error / 10)];
386 pkt[2] = hex_asc[(error % 10)];
387 pkt[3] = '\0';
388}
389
390/*
391 * Thread ID accessors. We represent a flat TID space to GDB, where
392 * the per CPU idle threads (which under Linux all have PID 0) are
393 * remapped to negative TIDs.
394 */
395
84a0bd5b 396#define BUF_THREAD_ID_SIZE 8
53197fc4
JW		 397
398static char *pack_threadid(char *pkt, unsigned char *id)
399{
84a0bd5b
JW		 400 unsigned char *limit;
401 int lzero = 1;
402
403 limit = id + (BUF_THREAD_ID_SIZE / 2);
404 while (id < limit) {
405 if (!lzero || *id != 0) {
406 pkt = pack_hex_byte(pkt, *id);
407 lzero = 0;
408 }
409 id++;
410 }
53197fc4 411
84a0bd5b
JW		 412 if (lzero)
413 pkt = pack_hex_byte(pkt, 0);
53197fc4
JW		 414
415 return pkt;
416}
417
418static void int_to_threadref(unsigned char *id, int value)
419{
84a0bd5b 420 put_unaligned_be32(value, id);
53197fc4
JW		 421}
422
423static struct task_struct *getthread(struct pt_regs *regs, int tid)
424{
425 /*
426 * Non-positive TIDs are remapped to the cpu shadow information
427 */
428 if (tid == 0 || tid == -1)
429 tid = -atomic_read(&kgdb_active) - 2;
430 if (tid < -1 && tid > -NR_CPUS - 2) {
431 if (kgdb_info[-tid - 2].task)
432 return kgdb_info[-tid - 2].task;
433 else
434 return idle_task(-tid - 2);
435 }
436 if (tid <= 0) {
437 printk(KERN_ERR "KGDB: Internal thread select error\n");
438 dump_stack();
439 return NULL;
440 }
441
442 /*
443 * find_task_by_pid_ns() does not take the tasklist lock anymore
444 * but is nicely RCU locked - hence is a pretty resilient
445 * thing to use:
446 */
447 return find_task_by_pid_ns(tid, &init_pid_ns);
448}
449
450
451/*
452 * Remap normal tasks to their real PID,
453 * CPU shadow threads are mapped to -CPU - 2
454 */
455static inline int shadow_pid(int realpid)
456{
457 if (realpid)
458 return realpid;
459
460 return -raw_smp_processor_id() - 2;
461}
462
463/*
464 * All the functions that start with gdb_cmd are the various
465 * operations to implement the handlers for the gdbserial protocol
466 * where KGDB is communicating with an external debugger
467 */
468
469/* Handle the '?' status packets */
470static void gdb_cmd_status(struct kgdb_state *ks)
471{
472 /*
473 * We know that this packet is only sent
474 * during initial connect. So to be safe,
475 * we clear out our breakpoints now in case
476 * GDB is reconnecting.
477 */
478 dbg_remove_all_break();
479
480 remcom_out_buffer[0] = 'S';
481 pack_hex_byte(&remcom_out_buffer[1], ks->signo);
482}
483
484/* Handle the 'g' get registers request */
485static void gdb_cmd_getregs(struct kgdb_state *ks)
486{
487 struct task_struct *thread;
488 void *local_debuggerinfo;
489 int i;
490
491 thread = kgdb_usethread;
492 if (!thread) {
493 thread = kgdb_info[ks->cpu].task;
494 local_debuggerinfo = kgdb_info[ks->cpu].debuggerinfo;
495 } else {
496 local_debuggerinfo = NULL;
497 for_each_online_cpu(i) {
498 /*
499 * Try to find the task on some other
500 * or possibly this node if we do not
501 * find the matching task then we try
502 * to approximate the results.
503 */
504 if (thread == kgdb_info[i].task)
505 local_debuggerinfo = kgdb_info[i].debuggerinfo;
506 }
507 }
508
509 /*
510 * All threads that don't have debuggerinfo should be
511 * in schedule() sleeping, since all other CPUs
512 * are in kgdb_wait, and thus have debuggerinfo.
513 */
514 if (local_debuggerinfo) {
515 pt_regs_to_gdb_regs(gdb_regs, local_debuggerinfo);
516 } else {
517 /*
518 * Pull stuff saved during switch_to; nothing
519 * else is accessible (or even particularly
520 * relevant).
521 *
522 * This should be enough for a stack trace.
523 */
524 sleeping_thread_to_gdb_regs(gdb_regs, thread);
525 }
526 kgdb_mem2hex((char *)gdb_regs, remcom_out_buffer, NUMREGBYTES);
527}
528
529/* Handle the 'G' set registers request */
530static void gdb_cmd_setregs(struct kgdb_state *ks)
531{
532 kgdb_hex2mem(&remcom_in_buffer[1], (char *)gdb_regs, NUMREGBYTES);
533
534 if (kgdb_usethread && kgdb_usethread != current) {
535 error_packet(remcom_out_buffer, -EINVAL);
536 } else {
537 gdb_regs_to_pt_regs(gdb_regs, ks->linux_regs);
538 strcpy(remcom_out_buffer, "OK");
539 }
540}
541
542/* Handle the 'm' memory read bytes */
543static void gdb_cmd_memread(struct kgdb_state *ks)
544{
545 char *ptr = &remcom_in_buffer[1];
546 unsigned long length;
547 unsigned long addr;
548 int err;
549
550 if (kgdb_hex2long(&ptr, &addr) > 0 && *ptr++ == ',' &&
551 kgdb_hex2long(&ptr, &length) > 0) {
552 err = kgdb_mem2hex((char *)addr, remcom_out_buffer, length);
553 if (err)
554 error_packet(remcom_out_buffer, err);
555 } else {
556 error_packet(remcom_out_buffer, -EINVAL);
557 }
558}
559
560/* Handle the 'M' memory write bytes */
561static void gdb_cmd_memwrite(struct kgdb_state *ks)
562{
563 int err = write_mem_msg(0);
564
565 if (err)
566 error_packet(remcom_out_buffer, err);
567 else
568 strcpy(remcom_out_buffer, "OK");
569}
570
571/* Handle the 'X' memory binary write bytes */
572static void gdb_cmd_binwrite(struct kgdb_state *ks)
573{
574 int err = write_mem_msg(1);
575
576 if (err)
577 error_packet(remcom_out_buffer, err);
578 else
579 strcpy(remcom_out_buffer, "OK");
580}
581
582/* Handle the 'D' or 'k', detach or kill packets */
583static void gdb_cmd_detachkill(struct kgdb_state *ks)
584{
585 int error;
586
587 /* The detach case */
588 if (remcom_in_buffer[0] == 'D') {
589 error = dbg_remove_all_break();
590 if (error < 0) {
591 error_packet(remcom_out_buffer, error);
592 } else {
593 strcpy(remcom_out_buffer, "OK");
594 kgdb_connected = 0;
595 }
596 put_packet(remcom_out_buffer);
597 } else {
598 /*
599 * Assume the kill case, with no exit code checking,
600 * trying to force detach the debugger:
601 */
602 dbg_remove_all_break();
603 kgdb_connected = 0;
604 }
605}
606
607/* Handle the 'R' reboot packets */
608static int gdb_cmd_reboot(struct kgdb_state *ks)
609{
610 /* For now, only honor R0 */
611 if (strcmp(remcom_in_buffer, "R0") == 0) {
612 printk(KERN_CRIT "Executing emergency reboot\n");
613 strcpy(remcom_out_buffer, "OK");
614 put_packet(remcom_out_buffer);
615
616 /*
617 * Execution should not return from
618 * machine_emergency_restart()
619 */
620 machine_emergency_restart();
621 kgdb_connected = 0;
622
623 return 1;
624 }
625 return 0;
626}
627
628/* Handle the 'q' query packets */
629static void gdb_cmd_query(struct kgdb_state *ks)
630{
631 struct task_struct *g;
632 struct task_struct *p;
84a0bd5b 633 unsigned char thref[BUF_THREAD_ID_SIZE];
53197fc4
JW		 634 char *ptr;
635 int i;
636 int cpu;
637 int finished = 0;
638
639 switch (remcom_in_buffer[1]) {
640 case 's':
641 case 'f':
fb82c0ff 642 if (memcmp(remcom_in_buffer + 2, "ThreadInfo", 10))
53197fc4 643 break;
53197fc4
JW		 644
645 i = 0;
646 remcom_out_buffer[0] = 'm';
647 ptr = remcom_out_buffer + 1;
648 if (remcom_in_buffer[1] == 'f') {
649 /* Each cpu is a shadow thread */
650 for_each_online_cpu(cpu) {
651 ks->thr_query = 0;
652 int_to_threadref(thref, -cpu - 2);
84a0bd5b 653 ptr = pack_threadid(ptr, thref);
53197fc4
JW		 654 *(ptr++) = ',';
655 i++;
656 }
657 }
658
659 do_each_thread(g, p) {
660 if (i >= ks->thr_query && !finished) {
661 int_to_threadref(thref, p->pid);
84a0bd5b 662 ptr = pack_threadid(ptr, thref);
53197fc4
JW		 663 *(ptr++) = ',';
664 ks->thr_query++;
665 if (ks->thr_query % KGDB_MAX_THREAD_QUERY == 0)
666 finished = 1;
667 }
668 i++;
669 } while_each_thread(g, p);
670
671 *(--ptr) = '\0';
672 break;
673
674 case 'C':
675 /* Current thread id */
676 strcpy(remcom_out_buffer, "QC");
677 ks->threadid = shadow_pid(current->pid);
678 int_to_threadref(thref, ks->threadid);
679 pack_threadid(remcom_out_buffer + 2, thref);
680 break;
681 case 'T':
fb82c0ff 682 if (memcmp(remcom_in_buffer + 1, "ThreadExtraInfo,", 16))
53197fc4 683 break;
fb82c0ff 684
53197fc4
JW		 685 ks->threadid = 0;
686 ptr = remcom_in_buffer + 17;
687 kgdb_hex2long(&ptr, &ks->threadid);
688 if (!getthread(ks->linux_regs, ks->threadid)) {
689 error_packet(remcom_out_buffer, -EINVAL);
690 break;
691 }
692 if ((int)ks->threadid > 0) {
693 kgdb_mem2hex(getthread(ks->linux_regs,
694 ks->threadid)->comm,
695 remcom_out_buffer, 16);
696 } else {
697 static char tmpstr[23 + BUF_THREAD_ID_SIZE];
698
699 sprintf(tmpstr, "shadowCPU%d",
700 (int)(-ks->threadid - 2));
701 kgdb_mem2hex(tmpstr, remcom_out_buffer, strlen(tmpstr));
702 }
703 break;
a0de055c
JW		 704#ifdef CONFIG_KGDB_KDB
705 case 'R':
706 if (strncmp(remcom_in_buffer, "qRcmd,", 6) == 0) {
707 int len = strlen(remcom_in_buffer + 6);
708
709 if ((len % 2) != 0) {
710 strcpy(remcom_out_buffer, "E01");
711 break;
712 }
713 kgdb_hex2mem(remcom_in_buffer + 6,
714 remcom_out_buffer, len);
715 len = len / 2;
716 remcom_out_buffer[len++] = 0;
717
718 kdb_parse(remcom_out_buffer);
719 strcpy(remcom_out_buffer, "OK");
720 }
721 break;
722#endif
53197fc4
JW		 723 }
724}
725
726/* Handle the 'H' task query packets */
727static void gdb_cmd_task(struct kgdb_state *ks)
728{
729 struct task_struct *thread;
730 char *ptr;
731
732 switch (remcom_in_buffer[1]) {
733 case 'g':
734 ptr = &remcom_in_buffer[2];
735 kgdb_hex2long(&ptr, &ks->threadid);
736 thread = getthread(ks->linux_regs, ks->threadid);
737 if (!thread && ks->threadid > 0) {
738 error_packet(remcom_out_buffer, -EINVAL);
739 break;
740 }
741 kgdb_usethread = thread;
742 ks->kgdb_usethreadid = ks->threadid;
743 strcpy(remcom_out_buffer, "OK");
744 break;
745 case 'c':
746 ptr = &remcom_in_buffer[2];
747 kgdb_hex2long(&ptr, &ks->threadid);
748 if (!ks->threadid) {
749 kgdb_contthread = NULL;
750 } else {
751 thread = getthread(ks->linux_regs, ks->threadid);
752 if (!thread && ks->threadid > 0) {
753 error_packet(remcom_out_buffer, -EINVAL);
754 break;
755 }
756 kgdb_contthread = thread;
757 }
758 strcpy(remcom_out_buffer, "OK");
759 break;
760 }
761}
762
763/* Handle the 'T' thread query packets */
764static void gdb_cmd_thread(struct kgdb_state *ks)
765{
766 char *ptr = &remcom_in_buffer[1];
767 struct task_struct *thread;
768
769 kgdb_hex2long(&ptr, &ks->threadid);
770 thread = getthread(ks->linux_regs, ks->threadid);
771 if (thread)
772 strcpy(remcom_out_buffer, "OK");
773 else
774 error_packet(remcom_out_buffer, -EINVAL);
775}
776
777/* Handle the 'z' or 'Z' breakpoint remove or set packets */
778static void gdb_cmd_break(struct kgdb_state *ks)
779{
780 /*
781 * Since GDB-5.3, it's been drafted that '0' is a software
782 * breakpoint, '1' is a hardware breakpoint, so let's do that.
783 */
784 char *bpt_type = &remcom_in_buffer[1];
785 char *ptr = &remcom_in_buffer[2];
786 unsigned long addr;
787 unsigned long length;
788 int error = 0;
789
790 if (arch_kgdb_ops.set_hw_breakpoint && *bpt_type >= '1') {
791 /* Unsupported */
792 if (*bpt_type > '4')
793 return;
794 } else {
795 if (*bpt_type != '0' && *bpt_type != '1')
796 /* Unsupported. */
797 return;
798 }
799
800 /*
801 * Test if this is a hardware breakpoint, and
802 * if we support it:
803 */
804 if (*bpt_type == '1' && !(arch_kgdb_ops.flags & KGDB_HW_BREAKPOINT))
805 /* Unsupported. */
806 return;
807
808 if (*(ptr++) != ',') {
809 error_packet(remcom_out_buffer, -EINVAL);
810 return;
811 }
812 if (!kgdb_hex2long(&ptr, &addr)) {
813 error_packet(remcom_out_buffer, -EINVAL);
814 return;
815 }
816 if (*(ptr++) != ',' ||
817 !kgdb_hex2long(&ptr, &length)) {
818 error_packet(remcom_out_buffer, -EINVAL);
819 return;
820 }
821
822 if (remcom_in_buffer[0] == 'Z' && *bpt_type == '0')
823 error = dbg_set_sw_break(addr);
824 else if (remcom_in_buffer[0] == 'z' && *bpt_type == '0')
825 error = dbg_remove_sw_break(addr);
826 else if (remcom_in_buffer[0] == 'Z')
827 error = arch_kgdb_ops.set_hw_breakpoint(addr,
828 (int)length, *bpt_type - '0');
829 else if (remcom_in_buffer[0] == 'z')
830 error = arch_kgdb_ops.remove_hw_breakpoint(addr,
831 (int) length, *bpt_type - '0');
832
833 if (error == 0)
834 strcpy(remcom_out_buffer, "OK");
835 else
836 error_packet(remcom_out_buffer, error);
837}
838
839/* Handle the 'C' signal / exception passing packets */
840static int gdb_cmd_exception_pass(struct kgdb_state *ks)
841{
842 /* C09 == pass exception
843 * C15 == detach kgdb, pass exception
844 */
845 if (remcom_in_buffer[1] == '0' && remcom_in_buffer[2] == '9') {
846
847 ks->pass_exception = 1;
848 remcom_in_buffer[0] = 'c';
849
850 } else if (remcom_in_buffer[1] == '1' && remcom_in_buffer[2] == '5') {
851
852 ks->pass_exception = 1;
853 remcom_in_buffer[0] = 'D';
854 dbg_remove_all_break();
855 kgdb_connected = 0;
856 return 1;
857
858 } else {
859 gdbstub_msg_write("KGDB only knows signal 9 (pass)"
860 " and 15 (pass and disconnect)\n"
861 "Executing a continue without signal passing\n", 0);
862 remcom_in_buffer[0] = 'c';
863 }
864
865 /* Indicate fall through */
866 return -1;
867}
868
869/*
870 * This function performs all gdbserial command procesing
871 */
872int gdb_serial_stub(struct kgdb_state *ks)
873{
874 int error = 0;
875 int tmp;
876
877 /* Clear the out buffer. */
878 memset(remcom_out_buffer, 0, sizeof(remcom_out_buffer));
879
880 if (kgdb_connected) {
84a0bd5b 881 unsigned char thref[BUF_THREAD_ID_SIZE];
53197fc4
JW		 882 char *ptr;
883
884 /* Reply to host that an exception has occurred */
885 ptr = remcom_out_buffer;
886 *ptr++ = 'T';
887 ptr = pack_hex_byte(ptr, ks->signo);
888 ptr += strlen(strcpy(ptr, "thread:"));
889 int_to_threadref(thref, shadow_pid(current->pid));
890 ptr = pack_threadid(ptr, thref);
891 *ptr++ = ';';
892 put_packet(remcom_out_buffer);
893 }
894
895 kgdb_usethread = kgdb_info[ks->cpu].task;
896 ks->kgdb_usethreadid = shadow_pid(kgdb_info[ks->cpu].task->pid);
897 ks->pass_exception = 0;
898
899 while (1) {
900 error = 0;
901
902 /* Clear the out buffer. */
903 memset(remcom_out_buffer, 0, sizeof(remcom_out_buffer));
904
905 get_packet(remcom_in_buffer);
906
907 switch (remcom_in_buffer[0]) {
908 case '?': /* gdbserial status */
909 gdb_cmd_status(ks);
910 break;
911 case 'g': /* return the value of the CPU registers */
912 gdb_cmd_getregs(ks);
913 break;
914 case 'G': /* set the value of the CPU registers - return OK */
915 gdb_cmd_setregs(ks);
916 break;
917 case 'm': /* mAA..AA,LLLL Read LLLL bytes at address AA..AA */
918 gdb_cmd_memread(ks);
919 break;
920 case 'M': /* MAA..AA,LLLL: Write LLLL bytes at address AA..AA */
921 gdb_cmd_memwrite(ks);
922 break;
923 case 'X': /* XAA..AA,LLLL: Write LLLL bytes at address AA..AA */
924 gdb_cmd_binwrite(ks);
925 break;
926 /* kill or detach. KGDB should treat this like a
927 * continue.
928 */
929 case 'D': /* Debugger detach */
930 case 'k': /* Debugger detach via kill */
931 gdb_cmd_detachkill(ks);
932 goto default_handle;
933 case 'R': /* Reboot */
934 if (gdb_cmd_reboot(ks))
935 goto default_handle;
936 break;
937 case 'q': /* query command */
938 gdb_cmd_query(ks);
939 break;
940 case 'H': /* task related */
941 gdb_cmd_task(ks);
942 break;
943 case 'T': /* Query thread status */
944 gdb_cmd_thread(ks);
945 break;
946 case 'z': /* Break point remove */
947 case 'Z': /* Break point set */
948 gdb_cmd_break(ks);
949 break;
dcc78711
JW		 950#ifdef CONFIG_KGDB_KDB
951 case '3': /* Escape into back into kdb */
952 if (remcom_in_buffer[1] == '\0') {
953 gdb_cmd_detachkill(ks);
954 return DBG_PASS_EVENT;
955 }
956#endif
53197fc4
JW		 957 case 'C': /* Exception passing */
958 tmp = gdb_cmd_exception_pass(ks);
959 if (tmp > 0)
960 goto default_handle;
961 if (tmp == 0)
962 break;
963 /* Fall through on tmp < 0 */
964 case 'c': /* Continue packet */
965 case 's': /* Single step packet */
966 if (kgdb_contthread && kgdb_contthread != current) {
967 /* Can't switch threads in kgdb */
968 error_packet(remcom_out_buffer, -EINVAL);
969 break;
970 }
971 dbg_activate_sw_breakpoints();
972 /* Fall through to default processing */
973 default:
974default_handle:
975 error = kgdb_arch_handle_exception(ks->ex_vector,
976 ks->signo,
977 ks->err_code,
978 remcom_in_buffer,
979 remcom_out_buffer,
980 ks->linux_regs);
981 /*
982 * Leave cmd processing on error, detach,
983 * kill, continue, or single step.
984 */
985 if (error >= 0 || remcom_in_buffer[0] == 'D' ||
986 remcom_in_buffer[0] == 'k') {
987 error = 0;
988 goto kgdb_exit;
989 }
990
991 }
992
993 /* reply to the request */
994 put_packet(remcom_out_buffer);
995 }
996
997kgdb_exit:
998 if (ks->pass_exception)
999 error = 1;
1000 return error;
1001}
dcc78711
JW		 1002
1003int gdbstub_state(struct kgdb_state *ks, char *cmd)
1004{
1005 int error;
1006
1007 switch (cmd[0]) {
1008 case 'e':
1009 error = kgdb_arch_handle_exception(ks->ex_vector,
1010 ks->signo,
1011 ks->err_code,
1012 remcom_in_buffer,
1013 remcom_out_buffer,
1014 ks->linux_regs);
1015 return error;
1016 case 's':
1017 case 'c':
1018 strcpy(remcom_in_buffer, cmd);
1019 return 0;
1020 case '?':
1021 gdb_cmd_status(ks);
1022 break;
1023 case '\0':
1024 strcpy(remcom_out_buffer, "");
1025 break;
1026 }
1027 dbg_io_ops->write_char('+');
1028 put_packet(remcom_out_buffer);
1029 return 0;
1030}
kernel source for telekom puls (alcatel/mediatek)