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-rw-r--r--kernel/debug/gdbstub.c1017
1 files changed, 1017 insertions, 0 deletions
diff --git a/kernel/debug/gdbstub.c b/kernel/debug/gdbstub.c
new file mode 100644
index 000000000000..4b17b3269525
--- /dev/null
+++ b/kernel/debug/gdbstub.c
@@ -0,0 +1,1017 @@
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/kdb.h>
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
55static int hex(char ch)
56{
57 if ((ch >= 'a') && (ch <= 'f'))
58 return ch - 'a' + 10;
59 if ((ch >= '0') && (ch <= '9'))
60 return ch - '0';
61 if ((ch >= 'A') && (ch <= 'F'))
62 return ch - 'A' + 10;
63 return -1;
64}
65
66#ifdef CONFIG_KGDB_KDB
67static int gdbstub_read_wait(void)
68{
69 int ret = -1;
70 int i;
71
72 /* poll any additional I/O interfaces that are defined */
73 while (ret < 0)
74 for (i = 0; kdb_poll_funcs[i] != NULL; i++) {
75 ret = kdb_poll_funcs[i]();
76 if (ret > 0)
77 break;
78 }
79 return ret;
80}
81#else
82static int gdbstub_read_wait(void)
83{
84 int ret = dbg_io_ops->read_char();
85 while (ret == NO_POLL_CHAR)
86 ret = dbg_io_ops->read_char();
87 return ret;
88}
89#endif
90/* scan for the sequence $<data>#<checksum> */
91static void get_packet(char *buffer)
92{
93 unsigned char checksum;
94 unsigned char xmitcsum;
95 int count;
96 char ch;
97
98 do {
99 /*
100 * Spin and wait around for the start character, ignore all
101 * other characters:
102 */
103 while ((ch = (gdbstub_read_wait())) != '$')
104 /* nothing */;
105
106 kgdb_connected = 1;
107 checksum = 0;
108 xmitcsum = -1;
109
110 count = 0;
111
112 /*
113 * now, read until a # or end of buffer is found:
114 */
115 while (count < (BUFMAX - 1)) {
116 ch = gdbstub_read_wait();
117 if (ch == '#')
118 break;
119 checksum = checksum + ch;
120 buffer[count] = ch;
121 count = count + 1;
122 }
123 buffer[count] = 0;
124
125 if (ch == '#') {
126 xmitcsum = hex(gdbstub_read_wait()) << 4;
127 xmitcsum += hex(gdbstub_read_wait());
128
129 if (checksum != xmitcsum)
130 /* failed checksum */
131 dbg_io_ops->write_char('-');
132 else
133 /* successful transfer */
134 dbg_io_ops->write_char('+');
135 if (dbg_io_ops->flush)
136 dbg_io_ops->flush();
137 }
138 } while (checksum != xmitcsum);
139}
140
141/*
142 * Send the packet in buffer.
143 * Check for gdb connection if asked for.
144 */
145static void put_packet(char *buffer)
146{
147 unsigned char checksum;
148 int count;
149 char ch;
150
151 /*
152 * $<packet info>#<checksum>.
153 */
154 while (1) {
155 dbg_io_ops->write_char('$');
156 checksum = 0;
157 count = 0;
158
159 while ((ch = buffer[count])) {
160 dbg_io_ops->write_char(ch);
161 checksum += ch;
162 count++;
163 }
164
165 dbg_io_ops->write_char('#');
166 dbg_io_ops->write_char(hex_asc_hi(checksum));
167 dbg_io_ops->write_char(hex_asc_lo(checksum));
168 if (dbg_io_ops->flush)
169 dbg_io_ops->flush();
170
171 /* Now see what we get in reply. */
172 ch = gdbstub_read_wait();
173
174 if (ch == 3)
175 ch = gdbstub_read_wait();
176
177 /* If we get an ACK, we are done. */
178 if (ch == '+')
179 return;
180
181 /*
182 * If we get the start of another packet, this means
183 * that GDB is attempting to reconnect. We will NAK
184 * the packet being sent, and stop trying to send this
185 * packet.
186 */
187 if (ch == '$') {
188 dbg_io_ops->write_char('-');
189 if (dbg_io_ops->flush)
190 dbg_io_ops->flush();
191 return;
192 }
193 }
194}
195
196static char gdbmsgbuf[BUFMAX + 1];
197
198void gdbstub_msg_write(const char *s, int len)
199{
200 char *bufptr;
201 int wcount;
202 int i;
203
204 if (len == 0)
205 len = strlen(s);
206
207 /* 'O'utput */
208 gdbmsgbuf[0] = 'O';
209
210 /* Fill and send buffers... */
211 while (len > 0) {
212 bufptr = gdbmsgbuf + 1;
213
214 /* Calculate how many this time */
215 if ((len << 1) > (BUFMAX - 2))
216 wcount = (BUFMAX - 2) >> 1;
217 else
218 wcount = len;
219
220 /* Pack in hex chars */
221 for (i = 0; i < wcount; i++)
222 bufptr = pack_hex_byte(bufptr, s[i]);
223 *bufptr = '\0';
224
225 /* Move up */
226 s += wcount;
227 len -= wcount;
228
229 /* Write packet */
230 put_packet(gdbmsgbuf);
231 }
232}
233
234/*
235 * Convert the memory pointed to by mem into hex, placing result in
236 * buf. Return a pointer to the last char put in buf (null). May
237 * return an error.
238 */
239int kgdb_mem2hex(char *mem, char *buf, int count)
240{
241 char *tmp;
242 int err;
243
244 /*
245 * We use the upper half of buf as an intermediate buffer for the
246 * raw memory copy. Hex conversion will work against this one.
247 */
248 tmp = buf + count;
249
250 err = probe_kernel_read(tmp, mem, count);
251 if (!err) {
252 while (count > 0) {
253 buf = pack_hex_byte(buf, *tmp);
254 tmp++;
255 count--;
256 }
257
258 *buf = 0;
259 }
260
261 return err;
262}
263
264/*
265 * Convert the hex array pointed to by buf into binary to be placed in
266 * mem. Return a pointer to the character AFTER the last byte
267 * written. May return an error.
268 */
269int kgdb_hex2mem(char *buf, char *mem, int count)
270{
271 char *tmp_raw;
272 char *tmp_hex;
273
274 /*
275 * We use the upper half of buf as an intermediate buffer for the
276 * raw memory that is converted from hex.
277 */
278 tmp_raw = buf + count * 2;
279
280 tmp_hex = tmp_raw - 1;
281 while (tmp_hex >= buf) {
282 tmp_raw--;
283 *tmp_raw = hex(*tmp_hex--);
284 *tmp_raw |= hex(*tmp_hex--) << 4;
285 }
286
287 return probe_kernel_write(mem, tmp_raw, count);
288}
289
290/*
291 * While we find nice hex chars, build a long_val.
292 * Return number of chars processed.
293 */
294int kgdb_hex2long(char **ptr, unsigned long *long_val)
295{
296 int hex_val;
297 int num = 0;
298 int negate = 0;
299
300 *long_val = 0;
301
302 if (**ptr == '-') {
303 negate = 1;
304 (*ptr)++;
305 }
306 while (**ptr) {
307 hex_val = hex(**ptr);
308 if (hex_val < 0)
309 break;
310
311 *long_val = (*long_val << 4) | hex_val;
312 num++;
313 (*ptr)++;
314 }
315
316 if (negate)
317 *long_val = -*long_val;
318
319 return num;
320}
321
322/*
323 * Copy the binary array pointed to by buf into mem. Fix $, #, and
324 * 0x7d escaped with 0x7d. Return -EFAULT on failure or 0 on success.
325 * The input buf is overwitten with the result to write to mem.
326 */
327static int kgdb_ebin2mem(char *buf, char *mem, int count)
328{
329 int size = 0;
330 char *c = buf;
331
332 while (count-- > 0) {
333 c[size] = *buf++;
334 if (c[size] == 0x7d)
335 c[size] = *buf++ ^ 0x20;
336 size++;
337 }
338
339 return probe_kernel_write(mem, c, size);
340}
341
342/* Write memory due to an 'M' or 'X' packet. */
343static int write_mem_msg(int binary)
344{
345 char *ptr = &remcom_in_buffer[1];
346 unsigned long addr;
347 unsigned long length;
348 int err;
349
350 if (kgdb_hex2long(&ptr, &addr) > 0 && *(ptr++) == ',' &&
351 kgdb_hex2long(&ptr, &length) > 0 && *(ptr++) == ':') {
352 if (binary)
353 err = kgdb_ebin2mem(ptr, (char *)addr, length);
354 else
355 err = kgdb_hex2mem(ptr, (char *)addr, length);
356 if (err)
357 return err;
358 if (CACHE_FLUSH_IS_SAFE)
359 flush_icache_range(addr, addr + length);
360 return 0;
361 }
362
363 return -EINVAL;
364}
365
366static void error_packet(char *pkt, int error)
367{
368 error = -error;
369 pkt[0] = 'E';
370 pkt[1] = hex_asc[(error / 10)];
371 pkt[2] = hex_asc[(error % 10)];
372 pkt[3] = '\0';
373}
374
375/*
376 * Thread ID accessors. We represent a flat TID space to GDB, where
377 * the per CPU idle threads (which under Linux all have PID 0) are
378 * remapped to negative TIDs.
379 */
380
381#define BUF_THREAD_ID_SIZE 16
382
383static char *pack_threadid(char *pkt, unsigned char *id)
384{
385 char *limit;
386
387 limit = pkt + BUF_THREAD_ID_SIZE;
388 while (pkt < limit)
389 pkt = pack_hex_byte(pkt, *id++);
390
391 return pkt;
392}
393
394static void int_to_threadref(unsigned char *id, int value)
395{
396 unsigned char *scan;
397 int i = 4;
398
399 scan = (unsigned char *)id;
400 while (i--)
401 *scan++ = 0;
402 put_unaligned_be32(value, scan);
403}
404
405static struct task_struct *getthread(struct pt_regs *regs, int tid)
406{
407 /*
408 * Non-positive TIDs are remapped to the cpu shadow information
409 */
410 if (tid == 0 || tid == -1)
411 tid = -atomic_read(&kgdb_active) - 2;
412 if (tid < -1 && tid > -NR_CPUS - 2) {
413 if (kgdb_info[-tid - 2].task)
414 return kgdb_info[-tid - 2].task;
415 else
416 return idle_task(-tid - 2);
417 }
418 if (tid <= 0) {
419 printk(KERN_ERR "KGDB: Internal thread select error\n");
420 dump_stack();
421 return NULL;
422 }
423
424 /*
425 * find_task_by_pid_ns() does not take the tasklist lock anymore
426 * but is nicely RCU locked - hence is a pretty resilient
427 * thing to use:
428 */
429 return find_task_by_pid_ns(tid, &init_pid_ns);
430}
431
432
433/*
434 * Remap normal tasks to their real PID,
435 * CPU shadow threads are mapped to -CPU - 2
436 */
437static inline int shadow_pid(int realpid)
438{
439 if (realpid)
440 return realpid;
441
442 return -raw_smp_processor_id() - 2;
443}
444
445/*
446 * All the functions that start with gdb_cmd are the various
447 * operations to implement the handlers for the gdbserial protocol
448 * where KGDB is communicating with an external debugger
449 */
450
451/* Handle the '?' status packets */
452static void gdb_cmd_status(struct kgdb_state *ks)
453{
454 /*
455 * We know that this packet is only sent
456 * during initial connect. So to be safe,
457 * we clear out our breakpoints now in case
458 * GDB is reconnecting.
459 */
460 dbg_remove_all_break();
461
462 remcom_out_buffer[0] = 'S';
463 pack_hex_byte(&remcom_out_buffer[1], ks->signo);
464}
465
466/* Handle the 'g' get registers request */
467static void gdb_cmd_getregs(struct kgdb_state *ks)
468{
469 struct task_struct *thread;
470 void *local_debuggerinfo;
471 int i;
472
473 thread = kgdb_usethread;
474 if (!thread) {
475 thread = kgdb_info[ks->cpu].task;
476 local_debuggerinfo = kgdb_info[ks->cpu].debuggerinfo;
477 } else {
478 local_debuggerinfo = NULL;
479 for_each_online_cpu(i) {
480 /*
481 * Try to find the task on some other
482 * or possibly this node if we do not
483 * find the matching task then we try
484 * to approximate the results.
485 */
486 if (thread == kgdb_info[i].task)
487 local_debuggerinfo = kgdb_info[i].debuggerinfo;
488 }
489 }
490
491 /*
492 * All threads that don't have debuggerinfo should be
493 * in schedule() sleeping, since all other CPUs
494 * are in kgdb_wait, and thus have debuggerinfo.
495 */
496 if (local_debuggerinfo) {
497 pt_regs_to_gdb_regs(gdb_regs, local_debuggerinfo);
498 } else {
499 /*
500 * Pull stuff saved during switch_to; nothing
501 * else is accessible (or even particularly
502 * relevant).
503 *
504 * This should be enough for a stack trace.
505 */
506 sleeping_thread_to_gdb_regs(gdb_regs, thread);
507 }
508 kgdb_mem2hex((char *)gdb_regs, remcom_out_buffer, NUMREGBYTES);
509}
510
511/* Handle the 'G' set registers request */
512static void gdb_cmd_setregs(struct kgdb_state *ks)
513{
514 kgdb_hex2mem(&remcom_in_buffer[1], (char *)gdb_regs, NUMREGBYTES);
515
516 if (kgdb_usethread && kgdb_usethread != current) {
517 error_packet(remcom_out_buffer, -EINVAL);
518 } else {
519 gdb_regs_to_pt_regs(gdb_regs, ks->linux_regs);
520 strcpy(remcom_out_buffer, "OK");
521 }
522}
523
524/* Handle the 'm' memory read bytes */
525static void gdb_cmd_memread(struct kgdb_state *ks)
526{
527 char *ptr = &remcom_in_buffer[1];
528 unsigned long length;
529 unsigned long addr;
530 int err;
531
532 if (kgdb_hex2long(&ptr, &addr) > 0 && *ptr++ == ',' &&
533 kgdb_hex2long(&ptr, &length) > 0) {
534 err = kgdb_mem2hex((char *)addr, remcom_out_buffer, length);
535 if (err)
536 error_packet(remcom_out_buffer, err);
537 } else {
538 error_packet(remcom_out_buffer, -EINVAL);
539 }
540}
541
542/* Handle the 'M' memory write bytes */
543static void gdb_cmd_memwrite(struct kgdb_state *ks)
544{
545 int err = write_mem_msg(0);
546
547 if (err)
548 error_packet(remcom_out_buffer, err);
549 else
550 strcpy(remcom_out_buffer, "OK");
551}
552
553/* Handle the 'X' memory binary write bytes */
554static void gdb_cmd_binwrite(struct kgdb_state *ks)
555{
556 int err = write_mem_msg(1);
557
558 if (err)
559 error_packet(remcom_out_buffer, err);
560 else
561 strcpy(remcom_out_buffer, "OK");
562}
563
564/* Handle the 'D' or 'k', detach or kill packets */
565static void gdb_cmd_detachkill(struct kgdb_state *ks)
566{
567 int error;
568
569 /* The detach case */
570 if (remcom_in_buffer[0] == 'D') {
571 error = dbg_remove_all_break();
572 if (error < 0) {
573 error_packet(remcom_out_buffer, error);
574 } else {
575 strcpy(remcom_out_buffer, "OK");
576 kgdb_connected = 0;
577 }
578 put_packet(remcom_out_buffer);
579 } else {
580 /*
581 * Assume the kill case, with no exit code checking,
582 * trying to force detach the debugger:
583 */
584 dbg_remove_all_break();
585 kgdb_connected = 0;
586 }
587}
588
589/* Handle the 'R' reboot packets */
590static int gdb_cmd_reboot(struct kgdb_state *ks)
591{
592 /* For now, only honor R0 */
593 if (strcmp(remcom_in_buffer, "R0") == 0) {
594 printk(KERN_CRIT "Executing emergency reboot\n");
595 strcpy(remcom_out_buffer, "OK");
596 put_packet(remcom_out_buffer);
597
598 /*
599 * Execution should not return from
600 * machine_emergency_restart()
601 */
602 machine_emergency_restart();
603 kgdb_connected = 0;
604
605 return 1;
606 }
607 return 0;
608}
609
610/* Handle the 'q' query packets */
611static void gdb_cmd_query(struct kgdb_state *ks)
612{
613 struct task_struct *g;
614 struct task_struct *p;
615 unsigned char thref[8];
616 char *ptr;
617 int i;
618 int cpu;
619 int finished = 0;
620
621 switch (remcom_in_buffer[1]) {
622 case 's':
623 case 'f':
624 if (memcmp(remcom_in_buffer + 2, "ThreadInfo", 10)) {
625 error_packet(remcom_out_buffer, -EINVAL);
626 break;
627 }
628
629 i = 0;
630 remcom_out_buffer[0] = 'm';
631 ptr = remcom_out_buffer + 1;
632 if (remcom_in_buffer[1] == 'f') {
633 /* Each cpu is a shadow thread */
634 for_each_online_cpu(cpu) {
635 ks->thr_query = 0;
636 int_to_threadref(thref, -cpu - 2);
637 pack_threadid(ptr, thref);
638 ptr += BUF_THREAD_ID_SIZE;
639 *(ptr++) = ',';
640 i++;
641 }
642 }
643
644 do_each_thread(g, p) {
645 if (i >= ks->thr_query && !finished) {
646 int_to_threadref(thref, p->pid);
647 pack_threadid(ptr, thref);
648 ptr += BUF_THREAD_ID_SIZE;
649 *(ptr++) = ',';
650 ks->thr_query++;
651 if (ks->thr_query % KGDB_MAX_THREAD_QUERY == 0)
652 finished = 1;
653 }
654 i++;
655 } while_each_thread(g, p);
656
657 *(--ptr) = '\0';
658 break;
659
660 case 'C':
661 /* Current thread id */
662 strcpy(remcom_out_buffer, "QC");
663 ks->threadid = shadow_pid(current->pid);
664 int_to_threadref(thref, ks->threadid);
665 pack_threadid(remcom_out_buffer + 2, thref);
666 break;
667 case 'T':
668 if (memcmp(remcom_in_buffer + 1, "ThreadExtraInfo,", 16)) {
669 error_packet(remcom_out_buffer, -EINVAL);
670 break;
671 }
672 ks->threadid = 0;
673 ptr = remcom_in_buffer + 17;
674 kgdb_hex2long(&ptr, &ks->threadid);
675 if (!getthread(ks->linux_regs, ks->threadid)) {
676 error_packet(remcom_out_buffer, -EINVAL);
677 break;
678 }
679 if ((int)ks->threadid > 0) {
680 kgdb_mem2hex(getthread(ks->linux_regs,
681 ks->threadid)->comm,
682 remcom_out_buffer, 16);
683 } else {
684 static char tmpstr[23 + BUF_THREAD_ID_SIZE];
685
686 sprintf(tmpstr, "shadowCPU%d",
687 (int)(-ks->threadid - 2));
688 kgdb_mem2hex(tmpstr, remcom_out_buffer, strlen(tmpstr));
689 }
690 break;
691#ifdef CONFIG_KGDB_KDB
692 case 'R':
693 if (strncmp(remcom_in_buffer, "qRcmd,", 6) == 0) {
694 int len = strlen(remcom_in_buffer + 6);
695
696 if ((len % 2) != 0) {
697 strcpy(remcom_out_buffer, "E01");
698 break;
699 }
700 kgdb_hex2mem(remcom_in_buffer + 6,
701 remcom_out_buffer, len);
702 len = len / 2;
703 remcom_out_buffer[len++] = 0;
704
705 kdb_parse(remcom_out_buffer);
706 strcpy(remcom_out_buffer, "OK");
707 }
708 break;
709#endif
710 }
711}
712
713/* Handle the 'H' task query packets */
714static void gdb_cmd_task(struct kgdb_state *ks)
715{
716 struct task_struct *thread;
717 char *ptr;
718
719 switch (remcom_in_buffer[1]) {
720 case 'g':
721 ptr = &remcom_in_buffer[2];
722 kgdb_hex2long(&ptr, &ks->threadid);
723 thread = getthread(ks->linux_regs, ks->threadid);
724 if (!thread && ks->threadid > 0) {
725 error_packet(remcom_out_buffer, -EINVAL);
726 break;
727 }
728 kgdb_usethread = thread;
729 ks->kgdb_usethreadid = ks->threadid;
730 strcpy(remcom_out_buffer, "OK");
731 break;
732 case 'c':
733 ptr = &remcom_in_buffer[2];
734 kgdb_hex2long(&ptr, &ks->threadid);
735 if (!ks->threadid) {
736 kgdb_contthread = NULL;
737 } else {
738 thread = getthread(ks->linux_regs, ks->threadid);
739 if (!thread && ks->threadid > 0) {
740 error_packet(remcom_out_buffer, -EINVAL);
741 break;
742 }
743 kgdb_contthread = thread;
744 }
745 strcpy(remcom_out_buffer, "OK");
746 break;
747 }
748}
749
750/* Handle the 'T' thread query packets */
751static void gdb_cmd_thread(struct kgdb_state *ks)
752{
753 char *ptr = &remcom_in_buffer[1];
754 struct task_struct *thread;
755
756 kgdb_hex2long(&ptr, &ks->threadid);
757 thread = getthread(ks->linux_regs, ks->threadid);
758 if (thread)
759 strcpy(remcom_out_buffer, "OK");
760 else
761 error_packet(remcom_out_buffer, -EINVAL);
762}
763
764/* Handle the 'z' or 'Z' breakpoint remove or set packets */
765static void gdb_cmd_break(struct kgdb_state *ks)
766{
767 /*
768 * Since GDB-5.3, it's been drafted that '0' is a software
769 * breakpoint, '1' is a hardware breakpoint, so let's do that.
770 */
771 char *bpt_type = &remcom_in_buffer[1];
772 char *ptr = &remcom_in_buffer[2];
773 unsigned long addr;
774 unsigned long length;
775 int error = 0;
776
777 if (arch_kgdb_ops.set_hw_breakpoint && *bpt_type >= '1') {
778 /* Unsupported */
779 if (*bpt_type > '4')
780 return;
781 } else {
782 if (*bpt_type != '0' && *bpt_type != '1')
783 /* Unsupported. */
784 return;
785 }
786
787 /*
788 * Test if this is a hardware breakpoint, and
789 * if we support it:
790 */
791 if (*bpt_type == '1' && !(arch_kgdb_ops.flags & KGDB_HW_BREAKPOINT))
792 /* Unsupported. */
793 return;
794
795 if (*(ptr++) != ',') {
796 error_packet(remcom_out_buffer, -EINVAL);
797 return;
798 }
799 if (!kgdb_hex2long(&ptr, &addr)) {
800 error_packet(remcom_out_buffer, -EINVAL);
801 return;
802 }
803 if (*(ptr++) != ',' ||
804 !kgdb_hex2long(&ptr, &length)) {
805 error_packet(remcom_out_buffer, -EINVAL);
806 return;
807 }
808
809 if (remcom_in_buffer[0] == 'Z' && *bpt_type == '0')
810 error = dbg_set_sw_break(addr);
811 else if (remcom_in_buffer[0] == 'z' && *bpt_type == '0')
812 error = dbg_remove_sw_break(addr);
813 else if (remcom_in_buffer[0] == 'Z')
814 error = arch_kgdb_ops.set_hw_breakpoint(addr,
815 (int)length, *bpt_type - '0');
816 else if (remcom_in_buffer[0] == 'z')
817 error = arch_kgdb_ops.remove_hw_breakpoint(addr,
818 (int) length, *bpt_type - '0');
819
820 if (error == 0)
821 strcpy(remcom_out_buffer, "OK");
822 else
823 error_packet(remcom_out_buffer, error);
824}
825
826/* Handle the 'C' signal / exception passing packets */
827static int gdb_cmd_exception_pass(struct kgdb_state *ks)
828{
829 /* C09 == pass exception
830 * C15 == detach kgdb, pass exception
831 */
832 if (remcom_in_buffer[1] == '0' && remcom_in_buffer[2] == '9') {
833
834 ks->pass_exception = 1;
835 remcom_in_buffer[0] = 'c';
836
837 } else if (remcom_in_buffer[1] == '1' && remcom_in_buffer[2] == '5') {
838
839 ks->pass_exception = 1;
840 remcom_in_buffer[0] = 'D';
841 dbg_remove_all_break();
842 kgdb_connected = 0;
843 return 1;
844
845 } else {
846 gdbstub_msg_write("KGDB only knows signal 9 (pass)"
847 " and 15 (pass and disconnect)\n"
848 "Executing a continue without signal passing\n", 0);
849 remcom_in_buffer[0] = 'c';
850 }
851
852 /* Indicate fall through */
853 return -1;
854}
855
856/*
857 * This function performs all gdbserial command procesing
858 */
859int gdb_serial_stub(struct kgdb_state *ks)
860{
861 int error = 0;
862 int tmp;
863
864 /* Clear the out buffer. */
865 memset(remcom_out_buffer, 0, sizeof(remcom_out_buffer));
866
867 if (kgdb_connected) {
868 unsigned char thref[8];
869 char *ptr;
870
871 /* Reply to host that an exception has occurred */
872 ptr = remcom_out_buffer;
873 *ptr++ = 'T';
874 ptr = pack_hex_byte(ptr, ks->signo);
875 ptr += strlen(strcpy(ptr, "thread:"));
876 int_to_threadref(thref, shadow_pid(current->pid));
877 ptr = pack_threadid(ptr, thref);
878 *ptr++ = ';';
879 put_packet(remcom_out_buffer);
880 }
881
882 kgdb_usethread = kgdb_info[ks->cpu].task;
883 ks->kgdb_usethreadid = shadow_pid(kgdb_info[ks->cpu].task->pid);
884 ks->pass_exception = 0;
885
886 while (1) {
887 error = 0;
888
889 /* Clear the out buffer. */
890 memset(remcom_out_buffer, 0, sizeof(remcom_out_buffer));
891
892 get_packet(remcom_in_buffer);
893
894 switch (remcom_in_buffer[0]) {
895 case '?': /* gdbserial status */
896 gdb_cmd_status(ks);
897 break;
898 case 'g': /* return the value of the CPU registers */
899 gdb_cmd_getregs(ks);
900 break;
901 case 'G': /* set the value of the CPU registers - return OK */
902 gdb_cmd_setregs(ks);
903 break;
904 case 'm': /* mAA..AA,LLLL Read LLLL bytes at address AA..AA */
905 gdb_cmd_memread(ks);
906 break;
907 case 'M': /* MAA..AA,LLLL: Write LLLL bytes at address AA..AA */
908 gdb_cmd_memwrite(ks);
909 break;
910 case 'X': /* XAA..AA,LLLL: Write LLLL bytes at address AA..AA */
911 gdb_cmd_binwrite(ks);
912 break;
913 /* kill or detach. KGDB should treat this like a
914 * continue.
915 */
916 case 'D': /* Debugger detach */
917 case 'k': /* Debugger detach via kill */
918 gdb_cmd_detachkill(ks);
919 goto default_handle;
920 case 'R': /* Reboot */
921 if (gdb_cmd_reboot(ks))
922 goto default_handle;
923 break;
924 case 'q': /* query command */
925 gdb_cmd_query(ks);
926 break;
927 case 'H': /* task related */
928 gdb_cmd_task(ks);
929 break;
930 case 'T': /* Query thread status */
931 gdb_cmd_thread(ks);
932 break;
933 case 'z': /* Break point remove */
934 case 'Z': /* Break point set */
935 gdb_cmd_break(ks);
936 break;
937#ifdef CONFIG_KGDB_KDB
938 case '3': /* Escape into back into kdb */
939 if (remcom_in_buffer[1] == '\0') {
940 gdb_cmd_detachkill(ks);
941 return DBG_PASS_EVENT;
942 }
943#endif
944 case 'C': /* Exception passing */
945 tmp = gdb_cmd_exception_pass(ks);
946 if (tmp > 0)
947 goto default_handle;
948 if (tmp == 0)
949 break;
950 /* Fall through on tmp < 0 */
951 case 'c': /* Continue packet */
952 case 's': /* Single step packet */
953 if (kgdb_contthread && kgdb_contthread != current) {
954 /* Can't switch threads in kgdb */
955 error_packet(remcom_out_buffer, -EINVAL);
956 break;
957 }
958 dbg_activate_sw_breakpoints();
959 /* Fall through to default processing */
960 default:
961default_handle:
962 error = kgdb_arch_handle_exception(ks->ex_vector,
963 ks->signo,
964 ks->err_code,
965 remcom_in_buffer,
966 remcom_out_buffer,
967 ks->linux_regs);
968 /*
969 * Leave cmd processing on error, detach,
970 * kill, continue, or single step.
971 */
972 if (error >= 0 || remcom_in_buffer[0] == 'D' ||
973 remcom_in_buffer[0] == 'k') {
974 error = 0;
975 goto kgdb_exit;
976 }
977
978 }
979
980 /* reply to the request */
981 put_packet(remcom_out_buffer);
982 }
983
984kgdb_exit:
985 if (ks->pass_exception)
986 error = 1;
987 return error;
988}
989
990int gdbstub_state(struct kgdb_state *ks, char *cmd)
991{
992 int error;
993
994 switch (cmd[0]) {
995 case 'e':
996 error = kgdb_arch_handle_exception(ks->ex_vector,
997 ks->signo,
998 ks->err_code,
999 remcom_in_buffer,
1000 remcom_out_buffer,
1001 ks->linux_regs);
1002 return error;
1003 case 's':
1004 case 'c':
1005 strcpy(remcom_in_buffer, cmd);
1006 return 0;
1007 case '?':
1008 gdb_cmd_status(ks);
1009 break;
1010 case '\0':
1011 strcpy(remcom_out_buffer, "");
1012 break;
1013 }
1014 dbg_io_ops->write_char('+');
1015 put_packet(remcom_out_buffer);
1016 return 0;
1017}
generated by cgit v1.2.2 (git 2.25.0) at 2025-06-02 06:27:07 -0400