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29
30#include <linux/pid_namespace.h>
31#include <linux/clocksource.h>
32#include <linux/interrupt.h>
33#include <linux/spinlock.h>
34#include <linux/console.h>
35#include <linux/threads.h>
36#include <linux/uaccess.h>
37#include <linux/kernel.h>
38#include <linux/module.h>
39#include <linux/ptrace.h>
40#include <linux/reboot.h>
41#include <linux/string.h>
42#include <linux/delay.h>
43#include <linux/sched.h>
44#include <linux/sysrq.h>
45#include <linux/init.h>
46#include <linux/kgdb.h>
47#include <linux/pid.h>
48#include <linux/smp.h>
49#include <linux/mm.h>
50
51#include <asm/cacheflush.h>
52#include <asm/byteorder.h>
53#include <asm/atomic.h>
54#include <asm/system.h>
55#include <asm/unaligned.h>
56
57static int kgdb_break_asap;
58
59#define KGDB_MAX_THREAD_QUERY 17
60struct kgdb_state {
61 int ex_vector;
62 int signo;
63 int err_code;
64 int cpu;
65 int pass_exception;
66 unsigned long thr_query;
67 unsigned long threadid;
68 long kgdb_usethreadid;
69 struct pt_regs *linux_regs;
70};
71
72static struct debuggerinfo_struct {
73 void *debuggerinfo;
74 struct task_struct *task;
75} kgdb_info[NR_CPUS];
76
77
78
79
80int kgdb_connected;
81EXPORT_SYMBOL_GPL(kgdb_connected);
82
83
84static int kgdb_io_module_registered;
85
86
87static int exception_level;
88
89static struct kgdb_io *kgdb_io_ops;
90static DEFINE_SPINLOCK(kgdb_registration_lock);
91
92
93static int kgdb_con_registered;
94
95static int kgdb_use_con;
96
97static int __init opt_kgdb_con(char *str)
98{
99 kgdb_use_con = 1;
100 return 0;
101}
102
103early_param("kgdbcon", opt_kgdb_con);
104
105module_param(kgdb_use_con, int, 0644);
106
107
108
109
110
111static struct kgdb_bkpt kgdb_break[KGDB_MAX_BREAKPOINTS] = {
112 [0 ... KGDB_MAX_BREAKPOINTS-1] = { .state = BP_UNDEFINED }
113};
114
115
116
117
118atomic_t kgdb_active = ATOMIC_INIT(-1);
119
120
121
122
123
124static atomic_t passive_cpu_wait[NR_CPUS];
125static atomic_t cpu_in_kgdb[NR_CPUS];
126atomic_t kgdb_setting_breakpoint;
127
128struct task_struct *kgdb_usethread;
129struct task_struct *kgdb_contthread;
130
131int kgdb_single_step;
132
133
134static char remcom_in_buffer[BUFMAX];
135static char remcom_out_buffer[BUFMAX];
136
137
138static unsigned long gdb_regs[(NUMREGBYTES +
139 sizeof(unsigned long) - 1) /
140 sizeof(unsigned long)];
141
142
143atomic_t kgdb_cpu_doing_single_step = ATOMIC_INIT(-1);
144
145
146
147
148
149
150
151
152static int kgdb_do_roundup = 1;
153
154static int __init opt_nokgdbroundup(char *str)
155{
156 kgdb_do_roundup = 0;
157
158 return 0;
159}
160
161early_param("nokgdbroundup", opt_nokgdbroundup);
162
163
164
165
166
167
168
169
170
171int __weak kgdb_arch_set_breakpoint(unsigned long addr, char *saved_instr)
172{
173 int err;
174
175 err = probe_kernel_read(saved_instr, (char *)addr, BREAK_INSTR_SIZE);
176 if (err)
177 return err;
178
179 return probe_kernel_write((char *)addr, arch_kgdb_ops.gdb_bpt_instr,
180 BREAK_INSTR_SIZE);
181}
182
183int __weak kgdb_arch_remove_breakpoint(unsigned long addr, char *bundle)
184{
185 return probe_kernel_write((char *)addr,
186 (char *)bundle, BREAK_INSTR_SIZE);
187}
188
189int __weak kgdb_validate_break_address(unsigned long addr)
190{
191 char tmp_variable[BREAK_INSTR_SIZE];
192 int err;
193
194
195
196
197
198 err = kgdb_arch_set_breakpoint(addr, tmp_variable);
199 if (err)
200 return err;
201 err = kgdb_arch_remove_breakpoint(addr, tmp_variable);
202 if (err)
203 printk(KERN_ERR "KGDB: Critical breakpoint error, kernel "
204 "memory destroyed at: %lx", addr);
205 return err;
206}
207
208unsigned long __weak kgdb_arch_pc(int exception, struct pt_regs *regs)
209{
210 return instruction_pointer(regs);
211}
212
213int __weak kgdb_arch_init(void)
214{
215 return 0;
216}
217
218int __weak kgdb_skipexception(int exception, struct pt_regs *regs)
219{
220 return 0;
221}
222
223void __weak
224kgdb_post_primary_code(struct pt_regs *regs, int e_vector, int err_code)
225{
226 return;
227}
228
229
230
231
232
233
234
235
236
237void __weak kgdb_disable_hw_debug(struct pt_regs *regs)
238{
239}
240
241
242
243
244
245static int hex(char ch)
246{
247 if ((ch >= 'a') && (ch <= 'f'))
248 return ch - 'a' + 10;
249 if ((ch >= '0') && (ch <= '9'))
250 return ch - '0';
251 if ((ch >= 'A') && (ch <= 'F'))
252 return ch - 'A' + 10;
253 return -1;
254}
255
256
257static void get_packet(char *buffer)
258{
259 unsigned char checksum;
260 unsigned char xmitcsum;
261 int count;
262 char ch;
263
264 do {
265
266
267
268
269 while ((ch = (kgdb_io_ops->read_char())) != '$')
270 ;
271
272 kgdb_connected = 1;
273 checksum = 0;
274 xmitcsum = -1;
275
276 count = 0;
277
278
279
280
281 while (count < (BUFMAX - 1)) {
282 ch = kgdb_io_ops->read_char();
283 if (ch == '#')
284 break;
285 checksum = checksum + ch;
286 buffer[count] = ch;
287 count = count + 1;
288 }
289 buffer[count] = 0;
290
291 if (ch == '#') {
292 xmitcsum = hex(kgdb_io_ops->read_char()) << 4;
293 xmitcsum += hex(kgdb_io_ops->read_char());
294
295 if (checksum != xmitcsum)
296
297 kgdb_io_ops->write_char('-');
298 else
299
300 kgdb_io_ops->write_char('+');
301 if (kgdb_io_ops->flush)
302 kgdb_io_ops->flush();
303 }
304 } while (checksum != xmitcsum);
305}
306
307
308
309
310
311static void put_packet(char *buffer)
312{
313 unsigned char checksum;
314 int count;
315 char ch;
316
317
318
319
320 while (1) {
321 kgdb_io_ops->write_char('$');
322 checksum = 0;
323 count = 0;
324
325 while ((ch = buffer[count])) {
326 kgdb_io_ops->write_char(ch);
327 checksum += ch;
328 count++;
329 }
330
331 kgdb_io_ops->write_char('#');
332 kgdb_io_ops->write_char(hex_asc_hi(checksum));
333 kgdb_io_ops->write_char(hex_asc_lo(checksum));
334 if (kgdb_io_ops->flush)
335 kgdb_io_ops->flush();
336
337
338 ch = kgdb_io_ops->read_char();
339
340 if (ch == 3)
341 ch = kgdb_io_ops->read_char();
342
343
344 if (ch == '+')
345 return;
346
347
348
349
350
351
352
353 if (ch == '$') {
354 kgdb_io_ops->write_char('-');
355 if (kgdb_io_ops->flush)
356 kgdb_io_ops->flush();
357 return;
358 }
359 }
360}
361
362
363
364
365
366int kgdb_mem2hex(char *mem, char *buf, int count)
367{
368 char *tmp;
369 int err;
370
371
372
373
374
375 tmp = buf + count;
376
377 err = probe_kernel_read(tmp, mem, count);
378 if (!err) {
379 while (count > 0) {
380 buf = pack_hex_byte(buf, *tmp);
381 tmp++;
382 count--;
383 }
384
385 *buf = 0;
386 }
387
388 return err;
389}
390
391
392
393
394
395
396static int kgdb_ebin2mem(char *buf, char *mem, int count)
397{
398 int err = 0;
399 char c;
400
401 while (count-- > 0) {
402 c = *buf++;
403 if (c == 0x7d)
404 c = *buf++ ^ 0x20;
405
406 err = probe_kernel_write(mem, &c, 1);
407 if (err)
408 break;
409
410 mem++;
411 }
412
413 return err;
414}
415
416
417
418
419
420
421int kgdb_hex2mem(char *buf, char *mem, int count)
422{
423 char *tmp_raw;
424 char *tmp_hex;
425
426
427
428
429
430 tmp_raw = buf + count * 2;
431
432 tmp_hex = tmp_raw - 1;
433 while (tmp_hex >= buf) {
434 tmp_raw--;
435 *tmp_raw = hex(*tmp_hex--);
436 *tmp_raw |= hex(*tmp_hex--) << 4;
437 }
438
439 return probe_kernel_write(mem, tmp_raw, count);
440}
441
442
443
444
445
446int kgdb_hex2long(char **ptr, unsigned long *long_val)
447{
448 int hex_val;
449 int num = 0;
450 int negate = 0;
451
452 *long_val = 0;
453
454 if (**ptr == '-') {
455 negate = 1;
456 (*ptr)++;
457 }
458 while (**ptr) {
459 hex_val = hex(**ptr);
460 if (hex_val < 0)
461 break;
462
463 *long_val = (*long_val << 4) | hex_val;
464 num++;
465 (*ptr)++;
466 }
467
468 if (negate)
469 *long_val = -*long_val;
470
471 return num;
472}
473
474
475static int write_mem_msg(int binary)
476{
477 char *ptr = &remcom_in_buffer[1];
478 unsigned long addr;
479 unsigned long length;
480 int err;
481
482 if (kgdb_hex2long(&ptr, &addr) > 0 && *(ptr++) == ',' &&
483 kgdb_hex2long(&ptr, &length) > 0 && *(ptr++) == ':') {
484 if (binary)
485 err = kgdb_ebin2mem(ptr, (char *)addr, length);
486 else
487 err = kgdb_hex2mem(ptr, (char *)addr, length);
488 if (err)
489 return err;
490 if (CACHE_FLUSH_IS_SAFE)
491 flush_icache_range(addr, addr + length);
492 return 0;
493 }
494
495 return -EINVAL;
496}
497
498static void error_packet(char *pkt, int error)
499{
500 error = -error;
501 pkt[0] = 'E';
502 pkt[1] = hex_asc[(error / 10)];
503 pkt[2] = hex_asc[(error % 10)];
504 pkt[3] = '\0';
505}
506
507
508
509
510
511
512
513#define BUF_THREAD_ID_SIZE 16
514
515static char *pack_threadid(char *pkt, unsigned char *id)
516{
517 char *limit;
518
519 limit = pkt + BUF_THREAD_ID_SIZE;
520 while (pkt < limit)
521 pkt = pack_hex_byte(pkt, *id++);
522
523 return pkt;
524}
525
526static void int_to_threadref(unsigned char *id, int value)
527{
528 unsigned char *scan;
529 int i = 4;
530
531 scan = (unsigned char *)id;
532 while (i--)
533 *scan++ = 0;
534 put_unaligned_be32(value, scan);
535}
536
537static struct task_struct *getthread(struct pt_regs *regs, int tid)
538{
539
540
541
542 if (tid == 0 || tid == -1)
543 tid = -atomic_read(&kgdb_active) - 2;
544 if (tid < 0) {
545 if (kgdb_info[-tid - 2].task)
546 return kgdb_info[-tid - 2].task;
547 else
548 return idle_task(-tid - 2);
549 }
550
551
552
553
554
555
556 return find_task_by_pid_ns(tid, &init_pid_ns);
557}
558
559
560
561
562
563#ifdef CONFIG_SMP
564static void kgdb_wait(struct pt_regs *regs)
565{
566 unsigned long flags;
567 int cpu;
568
569 local_irq_save(flags);
570 cpu = raw_smp_processor_id();
571 kgdb_info[cpu].debuggerinfo = regs;
572 kgdb_info[cpu].task = current;
573
574
575
576
577 smp_wmb();
578 atomic_set(&cpu_in_kgdb[cpu], 1);
579
580
581 while (atomic_read(&passive_cpu_wait[cpu]))
582 cpu_relax();
583
584 kgdb_info[cpu].debuggerinfo = NULL;
585 kgdb_info[cpu].task = NULL;
586
587
588 if (arch_kgdb_ops.correct_hw_break)
589 arch_kgdb_ops.correct_hw_break();
590
591
592 atomic_set(&cpu_in_kgdb[cpu], 0);
593 touch_softlockup_watchdog();
594 clocksource_touch_watchdog();
595 local_irq_restore(flags);
596}
597#endif
598
599
600
601
602
603static void kgdb_flush_swbreak_addr(unsigned long addr)
604{
605 if (!CACHE_FLUSH_IS_SAFE)
606 return;
607
608 if (current->mm && current->mm->mmap_cache) {
609 flush_cache_range(current->mm->mmap_cache,
610 addr, addr + BREAK_INSTR_SIZE);
611 }
612
613 flush_icache_range(addr, addr + BREAK_INSTR_SIZE);
614}
615
616
617
618
619static int kgdb_activate_sw_breakpoints(void)
620{
621 unsigned long addr;
622 int error = 0;
623 int i;
624
625 for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) {
626 if (kgdb_break[i].state != BP_SET)
627 continue;
628
629 addr = kgdb_break[i].bpt_addr;
630 error = kgdb_arch_set_breakpoint(addr,
631 kgdb_break[i].saved_instr);
632 if (error)
633 return error;
634
635 kgdb_flush_swbreak_addr(addr);
636 kgdb_break[i].state = BP_ACTIVE;
637 }
638 return 0;
639}
640
641static int kgdb_set_sw_break(unsigned long addr)
642{
643 int err = kgdb_validate_break_address(addr);
644 int breakno = -1;
645 int i;
646
647 if (err)
648 return err;
649
650 for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) {
651 if ((kgdb_break[i].state == BP_SET) &&
652 (kgdb_break[i].bpt_addr == addr))
653 return -EEXIST;
654 }
655 for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) {
656 if (kgdb_break[i].state == BP_REMOVED &&
657 kgdb_break[i].bpt_addr == addr) {
658 breakno = i;
659 break;
660 }
661 }
662
663 if (breakno == -1) {
664 for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) {
665 if (kgdb_break[i].state == BP_UNDEFINED) {
666 breakno = i;
667 break;
668 }
669 }
670 }
671
672 if (breakno == -1)
673 return -E2BIG;
674
675 kgdb_break[breakno].state = BP_SET;
676 kgdb_break[breakno].type = BP_BREAKPOINT;
677 kgdb_break[breakno].bpt_addr = addr;
678
679 return 0;
680}
681
682static int kgdb_deactivate_sw_breakpoints(void)
683{
684 unsigned long addr;
685 int error = 0;
686 int i;
687
688 for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) {
689 if (kgdb_break[i].state != BP_ACTIVE)
690 continue;
691 addr = kgdb_break[i].bpt_addr;
692 error = kgdb_arch_remove_breakpoint(addr,
693 kgdb_break[i].saved_instr);
694 if (error)
695 return error;
696
697 kgdb_flush_swbreak_addr(addr);
698 kgdb_break[i].state = BP_SET;
699 }
700 return 0;
701}
702
703static int kgdb_remove_sw_break(unsigned long addr)
704{
705 int i;
706
707 for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) {
708 if ((kgdb_break[i].state == BP_SET) &&
709 (kgdb_break[i].bpt_addr == addr)) {
710 kgdb_break[i].state = BP_REMOVED;
711 return 0;
712 }
713 }
714 return -ENOENT;
715}
716
717int kgdb_isremovedbreak(unsigned long addr)
718{
719 int i;
720
721 for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) {
722 if ((kgdb_break[i].state == BP_REMOVED) &&
723 (kgdb_break[i].bpt_addr == addr))
724 return 1;
725 }
726 return 0;
727}
728
729static int remove_all_break(void)
730{
731 unsigned long addr;
732 int error;
733 int i;
734
735
736 for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) {
737 if (kgdb_break[i].state != BP_ACTIVE)
738 goto setundefined;
739 addr = kgdb_break[i].bpt_addr;
740 error = kgdb_arch_remove_breakpoint(addr,
741 kgdb_break[i].saved_instr);
742 if (error)
743 printk(KERN_ERR "KGDB: breakpoint remove failed: %lx\n",
744 addr);
745setundefined:
746 kgdb_break[i].state = BP_UNDEFINED;
747 }
748
749
750 if (arch_kgdb_ops.remove_all_hw_break)
751 arch_kgdb_ops.remove_all_hw_break();
752
753 return 0;
754}
755
756
757
758
759
760static inline int shadow_pid(int realpid)
761{
762 if (realpid)
763 return realpid;
764
765 return -raw_smp_processor_id() - 2;
766}
767
768static char gdbmsgbuf[BUFMAX + 1];
769
770static void kgdb_msg_write(const char *s, int len)
771{
772 char *bufptr;
773 int wcount;
774 int i;
775
776
777 gdbmsgbuf[0] = 'O';
778
779
780 while (len > 0) {
781 bufptr = gdbmsgbuf + 1;
782
783
784 if ((len << 1) > (BUFMAX - 2))
785 wcount = (BUFMAX - 2) >> 1;
786 else
787 wcount = len;
788
789
790 for (i = 0; i < wcount; i++)
791 bufptr = pack_hex_byte(bufptr, s[i]);
792 *bufptr = '\0';
793
794
795 s += wcount;
796 len -= wcount;
797
798
799 put_packet(gdbmsgbuf);
800 }
801}
802
803
804
805
806
807
808
809
810
811
812static int kgdb_io_ready(int print_wait)
813{
814 if (!kgdb_io_ops)
815 return 0;
816 if (kgdb_connected)
817 return 1;
818 if (atomic_read(&kgdb_setting_breakpoint))
819 return 1;
820 if (print_wait)
821 printk(KERN_CRIT "KGDB: Waiting for remote debugger\n");
822 return 1;
823}
824
825
826
827
828
829
830
831
832static void gdb_cmd_status(struct kgdb_state *ks)
833{
834
835
836
837
838
839
840 remove_all_break();
841
842 remcom_out_buffer[0] = 'S';
843 pack_hex_byte(&remcom_out_buffer[1], ks->signo);
844}
845
846
847static void gdb_cmd_getregs(struct kgdb_state *ks)
848{
849 struct task_struct *thread;
850 void *local_debuggerinfo;
851 int i;
852
853 thread = kgdb_usethread;
854 if (!thread) {
855 thread = kgdb_info[ks->cpu].task;
856 local_debuggerinfo = kgdb_info[ks->cpu].debuggerinfo;
857 } else {
858 local_debuggerinfo = NULL;
859 for_each_online_cpu(i) {
860
861
862
863
864
865
866 if (thread == kgdb_info[i].task)
867 local_debuggerinfo = kgdb_info[i].debuggerinfo;
868 }
869 }
870
871
872
873
874
875
876 if (local_debuggerinfo) {
877 pt_regs_to_gdb_regs(gdb_regs, local_debuggerinfo);
878 } else {
879
880
881
882
883
884
885
886 sleeping_thread_to_gdb_regs(gdb_regs, thread);
887 }
888 kgdb_mem2hex((char *)gdb_regs, remcom_out_buffer, NUMREGBYTES);
889}
890
891
892static void gdb_cmd_setregs(struct kgdb_state *ks)
893{
894 kgdb_hex2mem(&remcom_in_buffer[1], (char *)gdb_regs, NUMREGBYTES);
895
896 if (kgdb_usethread && kgdb_usethread != current) {
897 error_packet(remcom_out_buffer, -EINVAL);
898 } else {
899 gdb_regs_to_pt_regs(gdb_regs, ks->linux_regs);
900 strcpy(remcom_out_buffer, "OK");
901 }
902}
903
904
905static void gdb_cmd_memread(struct kgdb_state *ks)
906{
907 char *ptr = &remcom_in_buffer[1];
908 unsigned long length;
909 unsigned long addr;
910 int err;
911
912 if (kgdb_hex2long(&ptr, &addr) > 0 && *ptr++ == ',' &&
913 kgdb_hex2long(&ptr, &length) > 0) {
914 err = kgdb_mem2hex((char *)addr, remcom_out_buffer, length);
915 if (err)
916 error_packet(remcom_out_buffer, err);
917 } else {
918 error_packet(remcom_out_buffer, -EINVAL);
919 }
920}
921
922
923static void gdb_cmd_memwrite(struct kgdb_state *ks)
924{
925 int err = write_mem_msg(0);
926
927 if (err)
928 error_packet(remcom_out_buffer, err);
929 else
930 strcpy(remcom_out_buffer, "OK");
931}
932
933
934static void gdb_cmd_binwrite(struct kgdb_state *ks)
935{
936 int err = write_mem_msg(1);
937
938 if (err)
939 error_packet(remcom_out_buffer, err);
940 else
941 strcpy(remcom_out_buffer, "OK");
942}
943
944
945static void gdb_cmd_detachkill(struct kgdb_state *ks)
946{
947 int error;
948
949
950 if (remcom_in_buffer[0] == 'D') {
951 error = remove_all_break();
952 if (error < 0) {
953 error_packet(remcom_out_buffer, error);
954 } else {
955 strcpy(remcom_out_buffer, "OK");
956 kgdb_connected = 0;
957 }
958 put_packet(remcom_out_buffer);
959 } else {
960
961
962
963
964 remove_all_break();
965 kgdb_connected = 0;
966 }
967}
968
969
970static int gdb_cmd_reboot(struct kgdb_state *ks)
971{
972
973 if (strcmp(remcom_in_buffer, "R0") == 0) {
974 printk(KERN_CRIT "Executing emergency reboot\n");
975 strcpy(remcom_out_buffer, "OK");
976 put_packet(remcom_out_buffer);
977
978
979
980
981
982 machine_emergency_restart();
983 kgdb_connected = 0;
984
985 return 1;
986 }
987 return 0;
988}
989
990
991static void gdb_cmd_query(struct kgdb_state *ks)
992{
993 struct task_struct *g;
994 struct task_struct *p;
995 unsigned char thref[8];
996 char *ptr;
997 int i;
998 int cpu;
999 int finished = 0;
1000
1001 switch (remcom_in_buffer[1]) {
1002 case 's':
1003 case 'f':
1004 if (memcmp(remcom_in_buffer + 2, "ThreadInfo", 10)) {
1005 error_packet(remcom_out_buffer, -EINVAL);
1006 break;
1007 }
1008
1009 i = 0;
1010 remcom_out_buffer[0] = 'm';
1011 ptr = remcom_out_buffer + 1;
1012 if (remcom_in_buffer[1] == 'f') {
1013
1014 for_each_online_cpu(cpu) {
1015 ks->thr_query = 0;
1016 int_to_threadref(thref, -cpu - 2);
1017 pack_threadid(ptr, thref);
1018 ptr += BUF_THREAD_ID_SIZE;
1019 *(ptr++) = ',';
1020 i++;
1021 }
1022 }
1023
1024 do_each_thread(g, p) {
1025 if (i >= ks->thr_query && !finished) {
1026 int_to_threadref(thref, p->pid);
1027 pack_threadid(ptr, thref);
1028 ptr += BUF_THREAD_ID_SIZE;
1029 *(ptr++) = ',';
1030 ks->thr_query++;
1031 if (ks->thr_query % KGDB_MAX_THREAD_QUERY == 0)
1032 finished = 1;
1033 }
1034 i++;
1035 } while_each_thread(g, p);
1036
1037 *(--ptr) = '\0';
1038 break;
1039
1040 case 'C':
1041
1042 strcpy(remcom_out_buffer, "QC");
1043 ks->threadid = shadow_pid(current->pid);
1044 int_to_threadref(thref, ks->threadid);
1045 pack_threadid(remcom_out_buffer + 2, thref);
1046 break;
1047 case 'T':
1048 if (memcmp(remcom_in_buffer + 1, "ThreadExtraInfo,", 16)) {
1049 error_packet(remcom_out_buffer, -EINVAL);
1050 break;
1051 }
1052 ks->threadid = 0;
1053 ptr = remcom_in_buffer + 17;
1054 kgdb_hex2long(&ptr, &ks->threadid);
1055 if (!getthread(ks->linux_regs, ks->threadid)) {
1056 error_packet(remcom_out_buffer, -EINVAL);
1057 break;
1058 }
1059 if ((int)ks->threadid > 0) {
1060 kgdb_mem2hex(getthread(ks->linux_regs,
1061 ks->threadid)->comm,
1062 remcom_out_buffer, 16);
1063 } else {
1064 static char tmpstr[23 + BUF_THREAD_ID_SIZE];
1065
1066 sprintf(tmpstr, "shadowCPU%d",
1067 (int)(-ks->threadid - 2));
1068 kgdb_mem2hex(tmpstr, remcom_out_buffer, strlen(tmpstr));
1069 }
1070 break;
1071 }
1072}
1073
1074
1075static void gdb_cmd_task(struct kgdb_state *ks)
1076{
1077 struct task_struct *thread;
1078 char *ptr;
1079
1080 switch (remcom_in_buffer[1]) {
1081 case 'g':
1082 ptr = &remcom_in_buffer[2];
1083 kgdb_hex2long(&ptr, &ks->threadid);
1084 thread = getthread(ks->linux_regs, ks->threadid);
1085 if (!thread && ks->threadid > 0) {
1086 error_packet(remcom_out_buffer, -EINVAL);
1087 break;
1088 }
1089 kgdb_usethread = thread;
1090 ks->kgdb_usethreadid = ks->threadid;
1091 strcpy(remcom_out_buffer, "OK");
1092 break;
1093 case 'c':
1094 ptr = &remcom_in_buffer[2];
1095 kgdb_hex2long(&ptr, &ks->threadid);
1096 if (!ks->threadid) {
1097 kgdb_contthread = NULL;
1098 } else {
1099 thread = getthread(ks->linux_regs, ks->threadid);
1100 if (!thread && ks->threadid > 0) {
1101 error_packet(remcom_out_buffer, -EINVAL);
1102 break;
1103 }
1104 kgdb_contthread = thread;
1105 }
1106 strcpy(remcom_out_buffer, "OK");
1107 break;
1108 }
1109}
1110
1111
1112static void gdb_cmd_thread(struct kgdb_state *ks)
1113{
1114 char *ptr = &remcom_in_buffer[1];
1115 struct task_struct *thread;
1116
1117 kgdb_hex2long(&ptr, &ks->threadid);
1118 thread = getthread(ks->linux_regs, ks->threadid);
1119 if (thread)
1120 strcpy(remcom_out_buffer, "OK");
1121 else
1122 error_packet(remcom_out_buffer, -EINVAL);
1123}
1124
1125
1126static void gdb_cmd_break(struct kgdb_state *ks)
1127{
1128
1129
1130
1131
1132 char *bpt_type = &remcom_in_buffer[1];
1133 char *ptr = &remcom_in_buffer[2];
1134 unsigned long addr;
1135 unsigned long length;
1136 int error = 0;
1137
1138 if (arch_kgdb_ops.set_hw_breakpoint && *bpt_type >= '1') {
1139
1140 if (*bpt_type > '4')
1141 return;
1142 } else {
1143 if (*bpt_type != '0' && *bpt_type != '1')
1144
1145 return;
1146 }
1147
1148
1149
1150
1151
1152 if (*bpt_type == '1' && !(arch_kgdb_ops.flags & KGDB_HW_BREAKPOINT))
1153
1154 return;
1155
1156 if (*(ptr++) != ',') {
1157 error_packet(remcom_out_buffer, -EINVAL);
1158 return;
1159 }
1160 if (!kgdb_hex2long(&ptr, &addr)) {
1161 error_packet(remcom_out_buffer, -EINVAL);
1162 return;
1163 }
1164 if (*(ptr++) != ',' ||
1165 !kgdb_hex2long(&ptr, &length)) {
1166 error_packet(remcom_out_buffer, -EINVAL);
1167 return;
1168 }
1169
1170 if (remcom_in_buffer[0] == 'Z' && *bpt_type == '0')
1171 error = kgdb_set_sw_break(addr);
1172 else if (remcom_in_buffer[0] == 'z' && *bpt_type == '0')
1173 error = kgdb_remove_sw_break(addr);
1174 else if (remcom_in_buffer[0] == 'Z')
1175 error = arch_kgdb_ops.set_hw_breakpoint(addr,
1176 (int)length, *bpt_type - '0');
1177 else if (remcom_in_buffer[0] == 'z')
1178 error = arch_kgdb_ops.remove_hw_breakpoint(addr,
1179 (int) length, *bpt_type - '0');
1180
1181 if (error == 0)
1182 strcpy(remcom_out_buffer, "OK");
1183 else
1184 error_packet(remcom_out_buffer, error);
1185}
1186
1187
1188static int gdb_cmd_exception_pass(struct kgdb_state *ks)
1189{
1190
1191
1192
1193 if (remcom_in_buffer[1] == '0' && remcom_in_buffer[2] == '9') {
1194
1195 ks->pass_exception = 1;
1196 remcom_in_buffer[0] = 'c';
1197
1198 } else if (remcom_in_buffer[1] == '1' && remcom_in_buffer[2] == '5') {
1199
1200 ks->pass_exception = 1;
1201 remcom_in_buffer[0] = 'D';
1202 remove_all_break();
1203 kgdb_connected = 0;
1204 return 1;
1205
1206 } else {
1207 error_packet(remcom_out_buffer, -EINVAL);
1208 return 0;
1209 }
1210
1211
1212 return -1;
1213}
1214
1215
1216
1217
1218static int gdb_serial_stub(struct kgdb_state *ks)
1219{
1220 int error = 0;
1221 int tmp;
1222
1223
1224 memset(remcom_out_buffer, 0, sizeof(remcom_out_buffer));
1225
1226 if (kgdb_connected) {
1227 unsigned char thref[8];
1228 char *ptr;
1229
1230
1231 ptr = remcom_out_buffer;
1232 *ptr++ = 'T';
1233 ptr = pack_hex_byte(ptr, ks->signo);
1234 ptr += strlen(strcpy(ptr, "thread:"));
1235 int_to_threadref(thref, shadow_pid(current->pid));
1236 ptr = pack_threadid(ptr, thref);
1237 *ptr++ = ';';
1238 put_packet(remcom_out_buffer);
1239 }
1240
1241 kgdb_usethread = kgdb_info[ks->cpu].task;
1242 ks->kgdb_usethreadid = shadow_pid(kgdb_info[ks->cpu].task->pid);
1243 ks->pass_exception = 0;
1244
1245 while (1) {
1246 error = 0;
1247
1248
1249 memset(remcom_out_buffer, 0, sizeof(remcom_out_buffer));
1250
1251 get_packet(remcom_in_buffer);
1252
1253 switch (remcom_in_buffer[0]) {
1254 case '?':
1255 gdb_cmd_status(ks);
1256 break;
1257 case 'g':
1258 gdb_cmd_getregs(ks);
1259 break;
1260 case 'G':
1261 gdb_cmd_setregs(ks);
1262 break;
1263 case 'm':
1264 gdb_cmd_memread(ks);
1265 break;
1266 case 'M':
1267 gdb_cmd_memwrite(ks);
1268 break;
1269 case 'X':
1270 gdb_cmd_binwrite(ks);
1271 break;
1272
1273
1274
1275 case 'D':
1276 case 'k':
1277 gdb_cmd_detachkill(ks);
1278 goto default_handle;
1279 case 'R':
1280 if (gdb_cmd_reboot(ks))
1281 goto default_handle;
1282 break;
1283 case 'q':
1284 gdb_cmd_query(ks);
1285 break;
1286 case 'H':
1287 gdb_cmd_task(ks);
1288 break;
1289 case 'T':
1290 gdb_cmd_thread(ks);
1291 break;
1292 case 'z':
1293 case 'Z':
1294 gdb_cmd_break(ks);
1295 break;
1296 case 'C':
1297 tmp = gdb_cmd_exception_pass(ks);
1298 if (tmp > 0)
1299 goto default_handle;
1300 if (tmp == 0)
1301 break;
1302
1303 case 'c':
1304 case 's':
1305 if (kgdb_contthread && kgdb_contthread != current) {
1306
1307 error_packet(remcom_out_buffer, -EINVAL);
1308 break;
1309 }
1310 kgdb_activate_sw_breakpoints();
1311
1312 default:
1313default_handle:
1314 error = kgdb_arch_handle_exception(ks->ex_vector,
1315 ks->signo,
1316 ks->err_code,
1317 remcom_in_buffer,
1318 remcom_out_buffer,
1319 ks->linux_regs);
1320
1321
1322
1323
1324 if (error >= 0 || remcom_in_buffer[0] == 'D' ||
1325 remcom_in_buffer[0] == 'k') {
1326 error = 0;
1327 goto kgdb_exit;
1328 }
1329
1330 }
1331
1332
1333 put_packet(remcom_out_buffer);
1334 }
1335
1336kgdb_exit:
1337 if (ks->pass_exception)
1338 error = 1;
1339 return error;
1340}
1341
1342static int kgdb_reenter_check(struct kgdb_state *ks)
1343{
1344 unsigned long addr;
1345
1346 if (atomic_read(&kgdb_active) != raw_smp_processor_id())
1347 return 0;
1348
1349
1350 exception_level++;
1351 addr = kgdb_arch_pc(ks->ex_vector, ks->linux_regs);
1352 kgdb_deactivate_sw_breakpoints();
1353
1354
1355
1356
1357
1358
1359
1360 if (kgdb_remove_sw_break(addr) == 0) {
1361 exception_level = 0;
1362 kgdb_skipexception(ks->ex_vector, ks->linux_regs);
1363 kgdb_activate_sw_breakpoints();
1364 printk(KERN_CRIT "KGDB: re-enter error: breakpoint removed %lx\n",
1365 addr);
1366 WARN_ON_ONCE(1);
1367
1368 return 1;
1369 }
1370 remove_all_break();
1371 kgdb_skipexception(ks->ex_vector, ks->linux_regs);
1372
1373 if (exception_level > 1) {
1374 dump_stack();
1375 panic("Recursive entry to debugger");
1376 }
1377
1378 printk(KERN_CRIT "KGDB: re-enter exception: ALL breakpoints killed\n");
1379 dump_stack();
1380 panic("Recursive entry to debugger");
1381
1382 return 1;
1383}
1384
1385
1386
1387
1388
1389
1390
1391
1392int
1393kgdb_handle_exception(int evector, int signo, int ecode, struct pt_regs *regs)
1394{
1395 struct kgdb_state kgdb_var;
1396 struct kgdb_state *ks = &kgdb_var;
1397 unsigned long flags;
1398 int error = 0;
1399 int i, cpu;
1400
1401 ks->cpu = raw_smp_processor_id();
1402 ks->ex_vector = evector;
1403 ks->signo = signo;
1404 ks->ex_vector = evector;
1405 ks->err_code = ecode;
1406 ks->kgdb_usethreadid = 0;
1407 ks->linux_regs = regs;
1408
1409 if (kgdb_reenter_check(ks))
1410 return 0;
1411
1412acquirelock:
1413
1414
1415
1416
1417 local_irq_save(flags);
1418
1419 cpu = raw_smp_processor_id();
1420
1421
1422
1423
1424 while (atomic_cmpxchg(&kgdb_active, -1, cpu) != -1)
1425 cpu_relax();
1426
1427
1428
1429
1430
1431
1432 if (atomic_read(&kgdb_cpu_doing_single_step) != -1 &&
1433 atomic_read(&kgdb_cpu_doing_single_step) != cpu) {
1434
1435 atomic_set(&kgdb_active, -1);
1436 touch_softlockup_watchdog();
1437 clocksource_touch_watchdog();
1438 local_irq_restore(flags);
1439
1440 goto acquirelock;
1441 }
1442
1443 if (!kgdb_io_ready(1)) {
1444 error = 1;
1445 goto kgdb_restore;
1446 }
1447
1448
1449
1450
1451 if (kgdb_skipexception(ks->ex_vector, ks->linux_regs))
1452 goto kgdb_restore;
1453
1454
1455 if (kgdb_io_ops->pre_exception)
1456 kgdb_io_ops->pre_exception();
1457
1458 kgdb_info[ks->cpu].debuggerinfo = ks->linux_regs;
1459 kgdb_info[ks->cpu].task = current;
1460
1461 kgdb_disable_hw_debug(ks->linux_regs);
1462
1463
1464
1465
1466
1467 if (!kgdb_single_step) {
1468 for (i = 0; i < NR_CPUS; i++)
1469 atomic_set(&passive_cpu_wait[i], 1);
1470 }
1471
1472
1473
1474
1475
1476 atomic_set(&cpu_in_kgdb[ks->cpu], 1);
1477
1478#ifdef CONFIG_SMP
1479
1480 if ((!kgdb_single_step) && kgdb_do_roundup)
1481 kgdb_roundup_cpus(flags);
1482#endif
1483
1484
1485
1486
1487 for_each_online_cpu(i) {
1488 while (!atomic_read(&cpu_in_kgdb[i]))
1489 cpu_relax();
1490 }
1491
1492
1493
1494
1495
1496 kgdb_post_primary_code(ks->linux_regs, ks->ex_vector, ks->err_code);
1497 kgdb_deactivate_sw_breakpoints();
1498 kgdb_single_step = 0;
1499 kgdb_contthread = current;
1500 exception_level = 0;
1501
1502
1503 error = gdb_serial_stub(ks);
1504
1505
1506 if (kgdb_io_ops->post_exception)
1507 kgdb_io_ops->post_exception();
1508
1509 kgdb_info[ks->cpu].debuggerinfo = NULL;
1510 kgdb_info[ks->cpu].task = NULL;
1511 atomic_set(&cpu_in_kgdb[ks->cpu], 0);
1512
1513 if (!kgdb_single_step) {
1514 for (i = NR_CPUS-1; i >= 0; i--)
1515 atomic_set(&passive_cpu_wait[i], 0);
1516
1517
1518
1519
1520 for_each_online_cpu(i) {
1521 while (atomic_read(&cpu_in_kgdb[i]))
1522 cpu_relax();
1523 }
1524 }
1525
1526kgdb_restore:
1527
1528 atomic_set(&kgdb_active, -1);
1529 touch_softlockup_watchdog();
1530 clocksource_touch_watchdog();
1531 local_irq_restore(flags);
1532
1533 return error;
1534}
1535
1536int kgdb_nmicallback(int cpu, void *regs)
1537{
1538#ifdef CONFIG_SMP
1539 if (!atomic_read(&cpu_in_kgdb[cpu]) &&
1540 atomic_read(&kgdb_active) != cpu &&
1541 atomic_read(&cpu_in_kgdb[atomic_read(&kgdb_active)])) {
1542 kgdb_wait((struct pt_regs *)regs);
1543 return 0;
1544 }
1545#endif
1546 return 1;
1547}
1548
1549static void kgdb_console_write(struct console *co, const char *s,
1550 unsigned count)
1551{
1552 unsigned long flags;
1553
1554
1555
1556 if (!kgdb_connected || atomic_read(&kgdb_active) != -1)
1557 return;
1558
1559 local_irq_save(flags);
1560 kgdb_msg_write(s, count);
1561 local_irq_restore(flags);
1562}
1563
1564static struct console kgdbcons = {
1565 .name = "kgdb",
1566 .write = kgdb_console_write,
1567 .flags = CON_PRINTBUFFER | CON_ENABLED,
1568 .index = -1,
1569};
1570
1571#ifdef CONFIG_MAGIC_SYSRQ
1572static void sysrq_handle_gdb(int key, struct tty_struct *tty)
1573{
1574 if (!kgdb_io_ops) {
1575 printk(KERN_CRIT "ERROR: No KGDB I/O module available\n");
1576 return;
1577 }
1578 if (!kgdb_connected)
1579 printk(KERN_CRIT "Entering KGDB\n");
1580
1581 kgdb_breakpoint();
1582}
1583
1584static struct sysrq_key_op sysrq_gdb_op = {
1585 .handler = sysrq_handle_gdb,
1586 .help_msg = "debug(G)",
1587 .action_msg = "DEBUG",
1588};
1589#endif
1590
1591static void kgdb_register_callbacks(void)
1592{
1593 if (!kgdb_io_module_registered) {
1594 kgdb_io_module_registered = 1;
1595 kgdb_arch_init();
1596#ifdef CONFIG_MAGIC_SYSRQ
1597 register_sysrq_key('g', &sysrq_gdb_op);
1598#endif
1599 if (kgdb_use_con && !kgdb_con_registered) {
1600 register_console(&kgdbcons);
1601 kgdb_con_registered = 1;
1602 }
1603 }
1604}
1605
1606static void kgdb_unregister_callbacks(void)
1607{
1608
1609
1610
1611
1612
1613 if (kgdb_io_module_registered) {
1614 kgdb_io_module_registered = 0;
1615 kgdb_arch_exit();
1616#ifdef CONFIG_MAGIC_SYSRQ
1617 unregister_sysrq_key('g', &sysrq_gdb_op);
1618#endif
1619 if (kgdb_con_registered) {
1620 unregister_console(&kgdbcons);
1621 kgdb_con_registered = 0;
1622 }
1623 }
1624}
1625
1626static void kgdb_initial_breakpoint(void)
1627{
1628 kgdb_break_asap = 0;
1629
1630 printk(KERN_CRIT "kgdb: Waiting for connection from remote gdb...\n");
1631 kgdb_breakpoint();
1632}
1633
1634
1635
1636
1637
1638
1639
1640int kgdb_register_io_module(struct kgdb_io *new_kgdb_io_ops)
1641{
1642 int err;
1643
1644 spin_lock(&kgdb_registration_lock);
1645
1646 if (kgdb_io_ops) {
1647 spin_unlock(&kgdb_registration_lock);
1648
1649 printk(KERN_ERR "kgdb: Another I/O driver is already "
1650 "registered with KGDB.\n");
1651 return -EBUSY;
1652 }
1653
1654 if (new_kgdb_io_ops->init) {
1655 err = new_kgdb_io_ops->init();
1656 if (err) {
1657 spin_unlock(&kgdb_registration_lock);
1658 return err;
1659 }
1660 }
1661
1662 kgdb_io_ops = new_kgdb_io_ops;
1663
1664 spin_unlock(&kgdb_registration_lock);
1665
1666 printk(KERN_INFO "kgdb: Registered I/O driver %s.\n",
1667 new_kgdb_io_ops->name);
1668
1669
1670 kgdb_register_callbacks();
1671
1672 if (kgdb_break_asap)
1673 kgdb_initial_breakpoint();
1674
1675 return 0;
1676}
1677EXPORT_SYMBOL_GPL(kgdb_register_io_module);
1678
1679
1680
1681
1682
1683
1684
1685void kgdb_unregister_io_module(struct kgdb_io *old_kgdb_io_ops)
1686{
1687 BUG_ON(kgdb_connected);
1688
1689
1690
1691
1692
1693 kgdb_unregister_callbacks();
1694
1695 spin_lock(&kgdb_registration_lock);
1696
1697 WARN_ON_ONCE(kgdb_io_ops != old_kgdb_io_ops);
1698 kgdb_io_ops = NULL;
1699
1700 spin_unlock(&kgdb_registration_lock);
1701
1702 printk(KERN_INFO
1703 "kgdb: Unregistered I/O driver %s, debugger disabled.\n",
1704 old_kgdb_io_ops->name);
1705}
1706EXPORT_SYMBOL_GPL(kgdb_unregister_io_module);
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716void kgdb_breakpoint(void)
1717{
1718 atomic_set(&kgdb_setting_breakpoint, 1);
1719 wmb();
1720 arch_kgdb_breakpoint();
1721 wmb();
1722 atomic_set(&kgdb_setting_breakpoint, 0);
1723}
1724EXPORT_SYMBOL_GPL(kgdb_breakpoint);
1725
1726static int __init opt_kgdb_wait(char *str)
1727{
1728 kgdb_break_asap = 1;
1729
1730 if (kgdb_io_module_registered)
1731 kgdb_initial_breakpoint();
1732
1733 return 0;
1734}
1735
1736early_param("kgdbwait", opt_kgdb_wait);
1737