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kgdb: core changes to support kdb
[net-next-2.6.git] / kernel / debug / gdbstub.c
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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. */
42static char remcom_in_buffer[BUFMAX];
43static char remcom_out_buffer[BUFMAX];
44
45/* Storage for the registers, in GDB format. */
46static unsigned long gdb_regs[(NUMREGBYTES +
47 sizeof(unsigned long) - 1) /
48 sizeof(unsigned long)];
49
50/*
51 * GDB remote protocol parser:
52 */
53
54static 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 $<data>#<checksum> */
66static void get_packet(char *buffer)
67{
68 unsigned char checksum;
69 unsigned char xmitcsum;
70 int count;
71 char ch;
72
73 do {
74 /*
75 * Spin and wait around for the start character, ignore all
76 * other characters:
77 */
78 while ((ch = (dbg_io_ops->read_char())) != '$')
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 */
120static 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
171static char gdbmsgbuf[BUFMAX + 1];
172
173void 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 */
211int 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 */
241int 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 */
266int 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 */
299static 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. */
315static 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
338static 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
355static 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
366static 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
377static 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 */
409static 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 */
424static 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 */
439static 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 */
484static 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 */
497static 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 */
515static 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 */
526static 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 */
537static 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 */
562static 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 */
583static 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 */
667static 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 */
704static 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 */
718static 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 */
780static 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 */
812int 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;
dcc78711
JW		 890#ifdef CONFIG_KGDB_KDB
891 case '3': /* Escape into back into kdb */
892 if (remcom_in_buffer[1] == '\0') {
893 gdb_cmd_detachkill(ks);
894 return DBG_PASS_EVENT;
895 }
896#endif
53197fc4
JW		 897 case 'C': /* Exception passing */
898 tmp = gdb_cmd_exception_pass(ks);
899 if (tmp > 0)
900 goto default_handle;
901 if (tmp == 0)
902 break;
903 /* Fall through on tmp < 0 */
904 case 'c': /* Continue packet */
905 case 's': /* Single step packet */
906 if (kgdb_contthread && kgdb_contthread != current) {
907 /* Can't switch threads in kgdb */
908 error_packet(remcom_out_buffer, -EINVAL);
909 break;
910 }
911 dbg_activate_sw_breakpoints();
912 /* Fall through to default processing */
913 default:
914default_handle:
915 error = kgdb_arch_handle_exception(ks->ex_vector,
916 ks->signo,
917 ks->err_code,
918 remcom_in_buffer,
919 remcom_out_buffer,
920 ks->linux_regs);
921 /*
922 * Leave cmd processing on error, detach,
923 * kill, continue, or single step.
924 */
925 if (error >= 0 || remcom_in_buffer[0] == 'D' ||
926 remcom_in_buffer[0] == 'k') {
927 error = 0;
928 goto kgdb_exit;
929 }
930
931 }
932
933 /* reply to the request */
934 put_packet(remcom_out_buffer);
935 }
936
937kgdb_exit:
938 if (ks->pass_exception)
939 error = 1;
940 return error;
941}
dcc78711
JW		 942
943int gdbstub_state(struct kgdb_state *ks, char *cmd)
944{
945 int error;
946
947 switch (cmd[0]) {
948 case 'e':
949 error = kgdb_arch_handle_exception(ks->ex_vector,
950 ks->signo,
951 ks->err_code,
952 remcom_in_buffer,
953 remcom_out_buffer,
954 ks->linux_regs);
955 return error;
956 case 's':
957 case 'c':
958 strcpy(remcom_in_buffer, cmd);
959 return 0;
960 case '?':
961 gdb_cmd_status(ks);
962 break;
963 case '\0':
964 strcpy(remcom_out_buffer, "");
965 break;
966 }
967 dbg_io_ops->write_char('+');
968 put_packet(remcom_out_buffer);
969 return 0;
970}
Clone of davem's net-next-2.6 tree