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1/*
2 * Kernel Debugger Architecture Independent Console I/O handler
3 *
4 * This file is subject to the terms and conditions of the GNU General Public
5 * License. See the file "COPYING" in the main directory of this archive
6 * for more details.
7 *
8 * Copyright (c) 1999-2006 Silicon Graphics, Inc. All Rights Reserved.
9 * Copyright (c) 2009 Wind River Systems, Inc. All Rights Reserved.
10 */
11
12#include <linux/module.h>
13#include <linux/types.h>
14#include <linux/ctype.h>
15#include <linux/kernel.h>
16#include <linux/init.h>
17#include <linux/kdev_t.h>
18#include <linux/console.h>
19#include <linux/string.h>
20#include <linux/sched.h>
21#include <linux/smp.h>
22#include <linux/nmi.h>
23#include <linux/delay.h>
24#include <linux/kgdb.h>
25#include <linux/kdb.h>
26#include <linux/kallsyms.h>
27#include "kdb_private.h"
28
29#define CMD_BUFLEN 256
30char kdb_prompt_str[CMD_BUFLEN];
31
32int kdb_trap_printk;
33
34static int kgdb_transition_check(char *buffer)
35{
36 if (buffer[0] != '+' && buffer[0] != '$') {
37 KDB_STATE_SET(KGDB_TRANS);
38 kdb_printf("%s", buffer);
39 } else {
40 int slen = strlen(buffer);
41 if (slen > 3 && buffer[slen - 3] == '#') {
42 kdb_gdb_state_pass(buffer);
43 strcpy(buffer, "kgdb");
44 KDB_STATE_SET(DOING_KGDB);
45 return 1;
46 }
47 }
48 return 0;
49}
50
51static int kdb_read_get_key(char *buffer, size_t bufsize)
52{
53#define ESCAPE_UDELAY 1000
54#define ESCAPE_DELAY (2*1000000/ESCAPE_UDELAY) /* 2 seconds worth of udelays */
55 char escape_data[5]; /* longest vt100 escape sequence is 4 bytes */
56 char *ped = escape_data;
57 int escape_delay = 0;
58 get_char_func *f, *f_escape = NULL;
59 int key;
60
61 for (f = &kdb_poll_funcs[0]; ; ++f) {
62 if (*f == NULL) {
63 /* Reset NMI watchdog once per poll loop */
64 touch_nmi_watchdog();
65 f = &kdb_poll_funcs[0];
66 }
67 if (escape_delay == 2) {
68 *ped = '\0';
69 ped = escape_data;
70 --escape_delay;
71 }
72 if (escape_delay == 1) {
73 key = *ped++;
74 if (!*ped)
75 --escape_delay;
76 break;
77 }
78 key = (*f)();
79 if (key == -1) {
80 if (escape_delay) {
81 udelay(ESCAPE_UDELAY);
82 --escape_delay;
83 }
84 continue;
85 }
86 if (bufsize <= 2) {
87 if (key == '\r')
88 key = '\n';
89 *buffer++ = key;
90 *buffer = '\0';
91 return -1;
92 }
93 if (escape_delay == 0 && key == '\e') {
94 escape_delay = ESCAPE_DELAY;
95 ped = escape_data;
96 f_escape = f;
97 }
98 if (escape_delay) {
99 *ped++ = key;
100 if (f_escape != f) {
101 escape_delay = 2;
102 continue;
103 }
104 if (ped - escape_data == 1) {
105 /* \e */
106 continue;
107 } else if (ped - escape_data == 2) {
108 /* \e<something> */
109 if (key != '[')
110 escape_delay = 2;
111 continue;
112 } else if (ped - escape_data == 3) {
113 /* \e[<something> */
114 int mapkey = 0;
115 switch (key) {
116 case 'A': /* \e[A, up arrow */
117 mapkey = 16;
118 break;
119 case 'B': /* \e[B, down arrow */
120 mapkey = 14;
121 break;
122 case 'C': /* \e[C, right arrow */
123 mapkey = 6;
124 break;
125 case 'D': /* \e[D, left arrow */
126 mapkey = 2;
127 break;
128 case '1': /* dropthrough */
129 case '3': /* dropthrough */
130 /* \e[<1,3,4>], may be home, del, end */
131 case '4':
132 mapkey = -1;
133 break;
134 }
135 if (mapkey != -1) {
136 if (mapkey > 0) {
137 escape_data[0] = mapkey;
138 escape_data[1] = '\0';
139 }
140 escape_delay = 2;
141 }
142 continue;
143 } else if (ped - escape_data == 4) {
144 /* \e[<1,3,4><something> */
145 int mapkey = 0;
146 if (key == '~') {
147 switch (escape_data[2]) {
148 case '1': /* \e[1~, home */
149 mapkey = 1;
150 break;
151 case '3': /* \e[3~, del */
152 mapkey = 4;
153 break;
154 case '4': /* \e[4~, end */
155 mapkey = 5;
156 break;
157 }
158 }
159 if (mapkey > 0) {
160 escape_data[0] = mapkey;
161 escape_data[1] = '\0';
162 }
163 escape_delay = 2;
164 continue;
165 }
166 }
167 break; /* A key to process */
168 }
169 return key;
170}
171
172/*
173 * kdb_read
174 *
175 * This function reads a string of characters, terminated by
176 * a newline, or by reaching the end of the supplied buffer,
177 * from the current kernel debugger console device.
178 * Parameters:
179 * buffer - Address of character buffer to receive input characters.
180 * bufsize - size, in bytes, of the character buffer
181 * Returns:
182 * Returns a pointer to the buffer containing the received
183 * character string. This string will be terminated by a
184 * newline character.
185 * Locking:
186 * No locks are required to be held upon entry to this
187 * function. It is not reentrant - it relies on the fact
188 * that while kdb is running on only one "master debug" cpu.
189 * Remarks:
190 *
191 * The buffer size must be >= 2. A buffer size of 2 means that the caller only
192 * wants a single key.
193 *
194 * An escape key could be the start of a vt100 control sequence such as \e[D
195 * (left arrow) or it could be a character in its own right. The standard
196 * method for detecting the difference is to wait for 2 seconds to see if there
197 * are any other characters. kdb is complicated by the lack of a timer service
198 * (interrupts are off), by multiple input sources and by the need to sometimes
199 * return after just one key. Escape sequence processing has to be done as
200 * states in the polling loop.
201 */
202
203static char *kdb_read(char *buffer, size_t bufsize)
204{
205 char *cp = buffer;
206 char *bufend = buffer+bufsize-2; /* Reserve space for newline
207 * and null byte */
208 char *lastchar;
209 char *p_tmp;
210 char tmp;
211 static char tmpbuffer[CMD_BUFLEN];
212 int len = strlen(buffer);
213 int len_tmp;
214 int tab = 0;
215 int count;
216 int i;
217 int diag, dtab_count;
218 int key;
219
220
221 diag = kdbgetintenv("DTABCOUNT", &dtab_count);
222 if (diag)
223 dtab_count = 30;
224
225 if (len > 0) {
226 cp += len;
227 if (*(buffer+len-1) == '\n')
228 cp--;
229 }
230
231 lastchar = cp;
232 *cp = '\0';
233 kdb_printf("%s", buffer);
234poll_again:
235 key = kdb_read_get_key(buffer, bufsize);
236 if (key == -1)
237 return buffer;
238 if (key != 9)
239 tab = 0;
240 switch (key) {
241 case 8: /* backspace */
242 if (cp > buffer) {
243 if (cp < lastchar) {
244 memcpy(tmpbuffer, cp, lastchar - cp);
245 memcpy(cp-1, tmpbuffer, lastchar - cp);
246 }
247 *(--lastchar) = '\0';
248 --cp;
249 kdb_printf("\b%s \r", cp);
250 tmp = *cp;
251 *cp = '\0';
252 kdb_printf(kdb_prompt_str);
253 kdb_printf("%s", buffer);
254 *cp = tmp;
255 }
256 break;
257 case 13: /* enter */
258 *lastchar++ = '\n';
259 *lastchar++ = '\0';
260 if (!KDB_STATE(KGDB_TRANS)) {
261 KDB_STATE_SET(KGDB_TRANS);
262 kdb_printf("%s", buffer);
263 }
264 kdb_printf("\n");
265 return buffer;
266 case 4: /* Del */
267 if (cp < lastchar) {
268 memcpy(tmpbuffer, cp+1, lastchar - cp - 1);
269 memcpy(cp, tmpbuffer, lastchar - cp - 1);
270 *(--lastchar) = '\0';
271 kdb_printf("%s \r", cp);
272 tmp = *cp;
273 *cp = '\0';
274 kdb_printf(kdb_prompt_str);
275 kdb_printf("%s", buffer);
276 *cp = tmp;
277 }
278 break;
279 case 1: /* Home */
280 if (cp > buffer) {
281 kdb_printf("\r");
282 kdb_printf(kdb_prompt_str);
283 cp = buffer;
284 }
285 break;
286 case 5: /* End */
287 if (cp < lastchar) {
288 kdb_printf("%s", cp);
289 cp = lastchar;
290 }
291 break;
292 case 2: /* Left */
293 if (cp > buffer) {
294 kdb_printf("\b");
295 --cp;
296 }
297 break;
298 case 14: /* Down */
299 memset(tmpbuffer, ' ',
300 strlen(kdb_prompt_str) + (lastchar-buffer));
301 *(tmpbuffer+strlen(kdb_prompt_str) +
302 (lastchar-buffer)) = '\0';
303 kdb_printf("\r%s\r", tmpbuffer);
304 *lastchar = (char)key;
305 *(lastchar+1) = '\0';
306 return lastchar;
307 case 6: /* Right */
308 if (cp < lastchar) {
309 kdb_printf("%c", *cp);
310 ++cp;
311 }
312 break;
313 case 16: /* Up */
314 memset(tmpbuffer, ' ',
315 strlen(kdb_prompt_str) + (lastchar-buffer));
316 *(tmpbuffer+strlen(kdb_prompt_str) +
317 (lastchar-buffer)) = '\0';
318 kdb_printf("\r%s\r", tmpbuffer);
319 *lastchar = (char)key;
320 *(lastchar+1) = '\0';
321 return lastchar;
322 case 9: /* Tab */
323 if (tab < 2)
324 ++tab;
325 p_tmp = buffer;
326 while (*p_tmp == ' ')
327 p_tmp++;
328 if (p_tmp > cp)
329 break;
330 memcpy(tmpbuffer, p_tmp, cp-p_tmp);
331 *(tmpbuffer + (cp-p_tmp)) = '\0';
332 p_tmp = strrchr(tmpbuffer, ' ');
333 if (p_tmp)
334 ++p_tmp;
335 else
336 p_tmp = tmpbuffer;
337 len = strlen(p_tmp);
338 count = kallsyms_symbol_complete(p_tmp,
339 sizeof(tmpbuffer) -
340 (p_tmp - tmpbuffer));
341 if (tab == 2 && count > 0) {
342 kdb_printf("\n%d symbols are found.", count);
343 if (count > dtab_count) {
344 count = dtab_count;
345 kdb_printf(" But only first %d symbols will"
346 " be printed.\nYou can change the"
347 " environment variable DTABCOUNT.",
348 count);
349 }
350 kdb_printf("\n");
351 for (i = 0; i < count; i++) {
352 if (kallsyms_symbol_next(p_tmp, i) < 0)
353 break;
354 kdb_printf("%s ", p_tmp);
355 *(p_tmp + len) = '\0';
356 }
357 if (i >= dtab_count)
358 kdb_printf("...");
359 kdb_printf("\n");
360 kdb_printf(kdb_prompt_str);
361 kdb_printf("%s", buffer);
362 } else if (tab != 2 && count > 0) {
363 len_tmp = strlen(p_tmp);
364 strncpy(p_tmp+len_tmp, cp, lastchar-cp+1);
365 len_tmp = strlen(p_tmp);
366 strncpy(cp, p_tmp+len, len_tmp-len + 1);
367 len = len_tmp - len;
368 kdb_printf("%s", cp);
369 cp += len;
370 lastchar += len;
371 }
372 kdb_nextline = 1; /* reset output line number */
373 break;
374 default:
375 if (key >= 32 && lastchar < bufend) {
376 if (cp < lastchar) {
377 memcpy(tmpbuffer, cp, lastchar - cp);
378 memcpy(cp+1, tmpbuffer, lastchar - cp);
379 *++lastchar = '\0';
380 *cp = key;
381 kdb_printf("%s\r", cp);
382 ++cp;
383 tmp = *cp;
384 *cp = '\0';
385 kdb_printf(kdb_prompt_str);
386 kdb_printf("%s", buffer);
387 *cp = tmp;
388 } else {
389 *++lastchar = '\0';
390 *cp++ = key;
391 /* The kgdb transition check will hide
392 * printed characters if we think that
393 * kgdb is connecting, until the check
394 * fails */
395 if (!KDB_STATE(KGDB_TRANS)) {
396 if (kgdb_transition_check(buffer))
397 return buffer;
398 } else {
399 kdb_printf("%c", key);
400 }
401 }
402 /* Special escape to kgdb */
403 if (lastchar - buffer >= 5 &&
404 strcmp(lastchar - 5, "$?#3f") == 0) {
405 kdb_gdb_state_pass(lastchar - 5);
406 strcpy(buffer, "kgdb");
407 KDB_STATE_SET(DOING_KGDB);
408 return buffer;
409 }
410 if (lastchar - buffer >= 11 &&
411 strcmp(lastchar - 11, "$qSupported") == 0) {
412 kdb_gdb_state_pass(lastchar - 11);
413 strcpy(buffer, "kgdb");
414 KDB_STATE_SET(DOING_KGDB);
415 return buffer;
416 }
417 }
418 break;
419 }
420 goto poll_again;
421}
422
423/*
424 * kdb_getstr
425 *
426 * Print the prompt string and read a command from the
427 * input device.
428 *
429 * Parameters:
430 * buffer Address of buffer to receive command
431 * bufsize Size of buffer in bytes
432 * prompt Pointer to string to use as prompt string
433 * Returns:
434 * Pointer to command buffer.
435 * Locking:
436 * None.
437 * Remarks:
438 * For SMP kernels, the processor number will be
439 * substituted for %d, %x or %o in the prompt.
440 */
441
442char *kdb_getstr(char *buffer, size_t bufsize, char *prompt)
443{
444 if (prompt && kdb_prompt_str != prompt)
445 strncpy(kdb_prompt_str, prompt, CMD_BUFLEN);
446 kdb_printf(kdb_prompt_str);
447 kdb_nextline = 1; /* Prompt and input resets line number */
448 return kdb_read(buffer, bufsize);
449}
450
451/*
452 * kdb_input_flush
453 *
454 * Get rid of any buffered console input.
455 *
456 * Parameters:
457 * none
458 * Returns:
459 * nothing
460 * Locking:
461 * none
462 * Remarks:
463 * Call this function whenever you want to flush input. If there is any
464 * outstanding input, it ignores all characters until there has been no
465 * data for approximately 1ms.
466 */
467
468static void kdb_input_flush(void)
469{
470 get_char_func *f;
471 int res;
472 int flush_delay = 1;
473 while (flush_delay) {
474 flush_delay--;
475empty:
476 touch_nmi_watchdog();
477 for (f = &kdb_poll_funcs[0]; *f; ++f) {
478 res = (*f)();
479 if (res != -1) {
480 flush_delay = 1;
481 goto empty;
482 }
483 }
484 if (flush_delay)
485 mdelay(1);
486 }
487}
488
489/*
490 * kdb_printf
491 *
492 * Print a string to the output device(s).
493 *
494 * Parameters:
495 * printf-like format and optional args.
496 * Returns:
497 * 0
498 * Locking:
499 * None.
500 * Remarks:
501 * use 'kdbcons->write()' to avoid polluting 'log_buf' with
502 * kdb output.
503 *
504 * If the user is doing a cmd args | grep srch
505 * then kdb_grepping_flag is set.
506 * In that case we need to accumulate full lines (ending in \n) before
507 * searching for the pattern.
508 */
509
510static char kdb_buffer[256]; /* A bit too big to go on stack */
511static char *next_avail = kdb_buffer;
512static int size_avail;
513static int suspend_grep;
514
515/*
516 * search arg1 to see if it contains arg2
517 * (kdmain.c provides flags for ^pat and pat$)
518 *
519 * return 1 for found, 0 for not found
520 */
521static int kdb_search_string(char *searched, char *searchfor)
522{
523 char firstchar, *cp;
524 int len1, len2;
525
526 /* not counting the newline at the end of "searched" */
527 len1 = strlen(searched)-1;
528 len2 = strlen(searchfor);
529 if (len1 < len2)
530 return 0;
531 if (kdb_grep_leading && kdb_grep_trailing && len1 != len2)
532 return 0;
533 if (kdb_grep_leading) {
534 if (!strncmp(searched, searchfor, len2))
535 return 1;
536 } else if (kdb_grep_trailing) {
537 if (!strncmp(searched+len1-len2, searchfor, len2))
538 return 1;
539 } else {
540 firstchar = *searchfor;
541 cp = searched;
542 while ((cp = strchr(cp, firstchar))) {
543 if (!strncmp(cp, searchfor, len2))
544 return 1;
545 cp++;
546 }
547 }
548 return 0;
549}
550
551int vkdb_printf(const char *fmt, va_list ap)
552{
553 int diag;
554 int linecount;
555 int colcount;
556 int logging, saved_loglevel = 0;
557 int saved_trap_printk;
558 int got_printf_lock = 0;
559 int retlen = 0;
560 int fnd, len;
561 char *cp, *cp2, *cphold = NULL, replaced_byte = ' ';
562 char *moreprompt = "more> ";
563 struct console *c = console_drivers;
564 static DEFINE_SPINLOCK(kdb_printf_lock);
565 unsigned long uninitialized_var(flags);
566
567 preempt_disable();
568 saved_trap_printk = kdb_trap_printk;
569 kdb_trap_printk = 0;
570
571 /* Serialize kdb_printf if multiple cpus try to write at once.
572 * But if any cpu goes recursive in kdb, just print the output,
573 * even if it is interleaved with any other text.
574 */
575 if (!KDB_STATE(PRINTF_LOCK)) {
576 KDB_STATE_SET(PRINTF_LOCK);
577 spin_lock_irqsave(&kdb_printf_lock, flags);
578 got_printf_lock = 1;
579 atomic_inc(&kdb_event);
580 } else {
581 __acquire(kdb_printf_lock);
582 }
583
584 diag = kdbgetintenv("LINES", &linecount);
585 if (diag || linecount <= 1)
586 linecount = 24;
587
588 diag = kdbgetintenv("COLUMNS", &colcount);
589 if (diag || colcount <= 1)
590 colcount = 80;
591
592 diag = kdbgetintenv("LOGGING", &logging);
593 if (diag)
594 logging = 0;
595
596 if (!kdb_grepping_flag || suspend_grep) {
597 /* normally, every vsnprintf starts a new buffer */
598 next_avail = kdb_buffer;
599 size_avail = sizeof(kdb_buffer);
600 }
601 vsnprintf(next_avail, size_avail, fmt, ap);
602
603 /*
604 * If kdb_parse() found that the command was cmd xxx | grep yyy
605 * then kdb_grepping_flag is set, and kdb_grep_string contains yyy
606 *
607 * Accumulate the print data up to a newline before searching it.
608 * (vsnprintf does null-terminate the string that it generates)
609 */
610
611 /* skip the search if prints are temporarily unconditional */
612 if (!suspend_grep && kdb_grepping_flag) {
613 cp = strchr(kdb_buffer, '\n');
614 if (!cp) {
615 /*
616 * Special cases that don't end with newlines
617 * but should be written without one:
618 * The "[nn]kdb> " prompt should
619 * appear at the front of the buffer.
620 *
621 * The "[nn]more " prompt should also be
622 * (MOREPROMPT -> moreprompt)
623 * written * but we print that ourselves,
624 * we set the suspend_grep flag to make
625 * it unconditional.
626 *
627 */
628 if (next_avail == kdb_buffer) {
629 /*
630 * these should occur after a newline,
631 * so they will be at the front of the
632 * buffer
633 */
634 cp2 = kdb_buffer;
635 len = strlen(kdb_prompt_str);
636 if (!strncmp(cp2, kdb_prompt_str, len)) {
637 /*
638 * We're about to start a new
639 * command, so we can go back
640 * to normal mode.
641 */
642 kdb_grepping_flag = 0;
643 goto kdb_printit;
644 }
645 }
646 /* no newline; don't search/write the buffer
647 until one is there */
648 len = strlen(kdb_buffer);
649 next_avail = kdb_buffer + len;
650 size_avail = sizeof(kdb_buffer) - len;
651 goto kdb_print_out;
652 }
653
654 /*
655 * The newline is present; print through it or discard
656 * it, depending on the results of the search.
657 */
658 cp++; /* to byte after the newline */
659 replaced_byte = *cp; /* remember what/where it was */
660 cphold = cp;
661 *cp = '\0'; /* end the string for our search */
662
663 /*
664 * We now have a newline at the end of the string
665 * Only continue with this output if it contains the
666 * search string.
667 */
668 fnd = kdb_search_string(kdb_buffer, kdb_grep_string);
669 if (!fnd) {
670 /*
671 * At this point the complete line at the start
672 * of kdb_buffer can be discarded, as it does
673 * not contain what the user is looking for.
674 * Shift the buffer left.
675 */
676 *cphold = replaced_byte;
677 strcpy(kdb_buffer, cphold);
678 len = strlen(kdb_buffer);
679 next_avail = kdb_buffer + len;
680 size_avail = sizeof(kdb_buffer) - len;
681 goto kdb_print_out;
682 }
683 /*
684 * at this point the string is a full line and
685 * should be printed, up to the null.
686 */
687 }
688kdb_printit:
689
690 /*
691 * Write to all consoles.
692 */
693 retlen = strlen(kdb_buffer);
694 if (!dbg_kdb_mode && kgdb_connected) {
695 gdbstub_msg_write(kdb_buffer, retlen);
696 } else {
697 if (dbg_io_ops && !dbg_io_ops->is_console) {
698 len = retlen;
699 cp = kdb_buffer;
700 while (len--) {
701 dbg_io_ops->write_char(*cp);
702 cp++;
703 }
704 }
705 while (c) {
706 c->write(c, kdb_buffer, retlen);
707 touch_nmi_watchdog();
708 c = c->next;
709 }
710 }
711 if (logging) {
712 saved_loglevel = console_loglevel;
713 console_loglevel = 0;
714 printk(KERN_INFO "%s", kdb_buffer);
715 }
716
717 if (KDB_STATE(PAGER)) {
718 /*
719 * Check printed string to decide how to bump the
720 * kdb_nextline to control when the more prompt should
721 * show up.
722 */
723 int got = 0;
724 len = retlen;
725 while (len--) {
726 if (kdb_buffer[len] == '\n') {
727 kdb_nextline++;
728 got = 0;
729 } else if (kdb_buffer[len] == '\r') {
730 got = 0;
731 } else {
732 got++;
733 }
734 }
735 kdb_nextline += got / (colcount + 1);
736 }
737
738 /* check for having reached the LINES number of printed lines */
739 if (kdb_nextline >= linecount) {
740 char buf1[16] = "";
741
742 /* Watch out for recursion here. Any routine that calls
743 * kdb_printf will come back through here. And kdb_read
744 * uses kdb_printf to echo on serial consoles ...
745 */
746 kdb_nextline = 1; /* In case of recursion */
747
748 /*
749 * Pause until cr.
750 */
751 moreprompt = kdbgetenv("MOREPROMPT");
752 if (moreprompt == NULL)
753 moreprompt = "more> ";
754
755 kdb_input_flush();
756 c = console_drivers;
757
758 if (dbg_io_ops && !dbg_io_ops->is_console) {
759 len = strlen(moreprompt);
760 cp = moreprompt;
761 while (len--) {
762 dbg_io_ops->write_char(*cp);
763 cp++;
764 }
765 }
766 while (c) {
767 c->write(c, moreprompt, strlen(moreprompt));
768 touch_nmi_watchdog();
769 c = c->next;
770 }
771
772 if (logging)
773 printk("%s", moreprompt);
774
775 kdb_read(buf1, 2); /* '2' indicates to return
776 * immediately after getting one key. */
777 kdb_nextline = 1; /* Really set output line 1 */
778
779 /* empty and reset the buffer: */
780 kdb_buffer[0] = '\0';
781 next_avail = kdb_buffer;
782 size_avail = sizeof(kdb_buffer);
783 if ((buf1[0] == 'q') || (buf1[0] == 'Q')) {
784 /* user hit q or Q */
785 KDB_FLAG_SET(CMD_INTERRUPT); /* command interrupted */
786 KDB_STATE_CLEAR(PAGER);
787 /* end of command output; back to normal mode */
788 kdb_grepping_flag = 0;
789 kdb_printf("\n");
790 } else if (buf1[0] == ' ') {
791 kdb_printf("\r");
792 suspend_grep = 1; /* for this recursion */
793 } else if (buf1[0] == '\n') {
794 kdb_nextline = linecount - 1;
795 kdb_printf("\r");
796 suspend_grep = 1; /* for this recursion */
797 } else if (buf1[0] && buf1[0] != '\n') {
798 /* user hit something other than enter */
799 suspend_grep = 1; /* for this recursion */
800 kdb_printf("\nOnly 'q' or 'Q' are processed at more "
801 "prompt, input ignored\n");
802 } else if (kdb_grepping_flag) {
803 /* user hit enter */
804 suspend_grep = 1; /* for this recursion */
805 kdb_printf("\n");
806 }
807 kdb_input_flush();
808 }
809
810 /*
811 * For grep searches, shift the printed string left.
812 * replaced_byte contains the character that was overwritten with
813 * the terminating null, and cphold points to the null.
814 * Then adjust the notion of available space in the buffer.
815 */
816 if (kdb_grepping_flag && !suspend_grep) {
817 *cphold = replaced_byte;
818 strcpy(kdb_buffer, cphold);
819 len = strlen(kdb_buffer);
820 next_avail = kdb_buffer + len;
821 size_avail = sizeof(kdb_buffer) - len;
822 }
823
824kdb_print_out:
825 suspend_grep = 0; /* end of what may have been a recursive call */
826 if (logging)
827 console_loglevel = saved_loglevel;
828 if (KDB_STATE(PRINTF_LOCK) && got_printf_lock) {
829 got_printf_lock = 0;
830 spin_unlock_irqrestore(&kdb_printf_lock, flags);
831 KDB_STATE_CLEAR(PRINTF_LOCK);
832 atomic_dec(&kdb_event);
833 } else {
834 __release(kdb_printf_lock);
835 }
836 kdb_trap_printk = saved_trap_printk;
837 preempt_enable();
838 return retlen;
839}
840
841int kdb_printf(const char *fmt, ...)
842{
843 va_list ap;
844 int r;
845
846 va_start(ap, fmt);
847 r = vkdb_printf(fmt, ap);
848 va_end(ap);
849
850 return r;
851}
852EXPORT_SYMBOL_GPL(kdb_printf);
1/*
2 * Kernel Debugger Architecture Independent Console I/O handler
3 *
4 * This file is subject to the terms and conditions of the GNU General Public
5 * License. See the file "COPYING" in the main directory of this archive
6 * for more details.
7 *
8 * Copyright (c) 1999-2006 Silicon Graphics, Inc. All Rights Reserved.
9 * Copyright (c) 2009 Wind River Systems, Inc. All Rights Reserved.
10 */
11
12#include <linux/module.h>
13#include <linux/types.h>
14#include <linux/ctype.h>
15#include <linux/kernel.h>
16#include <linux/init.h>
17#include <linux/kdev_t.h>
18#include <linux/console.h>
19#include <linux/string.h>
20#include <linux/sched.h>
21#include <linux/smp.h>
22#include <linux/nmi.h>
23#include <linux/delay.h>
24#include <linux/kgdb.h>
25#include <linux/kdb.h>
26#include <linux/kallsyms.h>
27#include "kdb_private.h"
28
29#define CMD_BUFLEN 256
30char kdb_prompt_str[CMD_BUFLEN];
31
32int kdb_trap_printk;
33int kdb_printf_cpu = -1;
34
35static int kgdb_transition_check(char *buffer)
36{
37 if (buffer[0] != '+' && buffer[0] != '$') {
38 KDB_STATE_SET(KGDB_TRANS);
39 kdb_printf("%s", buffer);
40 } else {
41 int slen = strlen(buffer);
42 if (slen > 3 && buffer[slen - 3] == '#') {
43 kdb_gdb_state_pass(buffer);
44 strcpy(buffer, "kgdb");
45 KDB_STATE_SET(DOING_KGDB);
46 return 1;
47 }
48 }
49 return 0;
50}
51
52static int kdb_read_get_key(char *buffer, size_t bufsize)
53{
54#define ESCAPE_UDELAY 1000
55#define ESCAPE_DELAY (2*1000000/ESCAPE_UDELAY) /* 2 seconds worth of udelays */
56 char escape_data[5]; /* longest vt100 escape sequence is 4 bytes */
57 char *ped = escape_data;
58 int escape_delay = 0;
59 get_char_func *f, *f_escape = NULL;
60 int key;
61
62 for (f = &kdb_poll_funcs[0]; ; ++f) {
63 if (*f == NULL) {
64 /* Reset NMI watchdog once per poll loop */
65 touch_nmi_watchdog();
66 f = &kdb_poll_funcs[0];
67 }
68 if (escape_delay == 2) {
69 *ped = '\0';
70 ped = escape_data;
71 --escape_delay;
72 }
73 if (escape_delay == 1) {
74 key = *ped++;
75 if (!*ped)
76 --escape_delay;
77 break;
78 }
79 key = (*f)();
80 if (key == -1) {
81 if (escape_delay) {
82 udelay(ESCAPE_UDELAY);
83 --escape_delay;
84 }
85 continue;
86 }
87 if (bufsize <= 2) {
88 if (key == '\r')
89 key = '\n';
90 *buffer++ = key;
91 *buffer = '\0';
92 return -1;
93 }
94 if (escape_delay == 0 && key == '\e') {
95 escape_delay = ESCAPE_DELAY;
96 ped = escape_data;
97 f_escape = f;
98 }
99 if (escape_delay) {
100 *ped++ = key;
101 if (f_escape != f) {
102 escape_delay = 2;
103 continue;
104 }
105 if (ped - escape_data == 1) {
106 /* \e */
107 continue;
108 } else if (ped - escape_data == 2) {
109 /* \e<something> */
110 if (key != '[')
111 escape_delay = 2;
112 continue;
113 } else if (ped - escape_data == 3) {
114 /* \e[<something> */
115 int mapkey = 0;
116 switch (key) {
117 case 'A': /* \e[A, up arrow */
118 mapkey = 16;
119 break;
120 case 'B': /* \e[B, down arrow */
121 mapkey = 14;
122 break;
123 case 'C': /* \e[C, right arrow */
124 mapkey = 6;
125 break;
126 case 'D': /* \e[D, left arrow */
127 mapkey = 2;
128 break;
129 case '1': /* dropthrough */
130 case '3': /* dropthrough */
131 /* \e[<1,3,4>], may be home, del, end */
132 case '4':
133 mapkey = -1;
134 break;
135 }
136 if (mapkey != -1) {
137 if (mapkey > 0) {
138 escape_data[0] = mapkey;
139 escape_data[1] = '\0';
140 }
141 escape_delay = 2;
142 }
143 continue;
144 } else if (ped - escape_data == 4) {
145 /* \e[<1,3,4><something> */
146 int mapkey = 0;
147 if (key == '~') {
148 switch (escape_data[2]) {
149 case '1': /* \e[1~, home */
150 mapkey = 1;
151 break;
152 case '3': /* \e[3~, del */
153 mapkey = 4;
154 break;
155 case '4': /* \e[4~, end */
156 mapkey = 5;
157 break;
158 }
159 }
160 if (mapkey > 0) {
161 escape_data[0] = mapkey;
162 escape_data[1] = '\0';
163 }
164 escape_delay = 2;
165 continue;
166 }
167 }
168 break; /* A key to process */
169 }
170 return key;
171}
172
173/*
174 * kdb_read
175 *
176 * This function reads a string of characters, terminated by
177 * a newline, or by reaching the end of the supplied buffer,
178 * from the current kernel debugger console device.
179 * Parameters:
180 * buffer - Address of character buffer to receive input characters.
181 * bufsize - size, in bytes, of the character buffer
182 * Returns:
183 * Returns a pointer to the buffer containing the received
184 * character string. This string will be terminated by a
185 * newline character.
186 * Locking:
187 * No locks are required to be held upon entry to this
188 * function. It is not reentrant - it relies on the fact
189 * that while kdb is running on only one "master debug" cpu.
190 * Remarks:
191 *
192 * The buffer size must be >= 2. A buffer size of 2 means that the caller only
193 * wants a single key.
194 *
195 * An escape key could be the start of a vt100 control sequence such as \e[D
196 * (left arrow) or it could be a character in its own right. The standard
197 * method for detecting the difference is to wait for 2 seconds to see if there
198 * are any other characters. kdb is complicated by the lack of a timer service
199 * (interrupts are off), by multiple input sources and by the need to sometimes
200 * return after just one key. Escape sequence processing has to be done as
201 * states in the polling loop.
202 */
203
204static char *kdb_read(char *buffer, size_t bufsize)
205{
206 char *cp = buffer;
207 char *bufend = buffer+bufsize-2; /* Reserve space for newline
208 * and null byte */
209 char *lastchar;
210 char *p_tmp;
211 char tmp;
212 static char tmpbuffer[CMD_BUFLEN];
213 int len = strlen(buffer);
214 int len_tmp;
215 int tab = 0;
216 int count;
217 int i;
218 int diag, dtab_count;
219 int key;
220
221
222 diag = kdbgetintenv("DTABCOUNT", &dtab_count);
223 if (diag)
224 dtab_count = 30;
225
226 if (len > 0) {
227 cp += len;
228 if (*(buffer+len-1) == '\n')
229 cp--;
230 }
231
232 lastchar = cp;
233 *cp = '\0';
234 kdb_printf("%s", buffer);
235poll_again:
236 key = kdb_read_get_key(buffer, bufsize);
237 if (key == -1)
238 return buffer;
239 if (key != 9)
240 tab = 0;
241 switch (key) {
242 case 8: /* backspace */
243 if (cp > buffer) {
244 if (cp < lastchar) {
245 memcpy(tmpbuffer, cp, lastchar - cp);
246 memcpy(cp-1, tmpbuffer, lastchar - cp);
247 }
248 *(--lastchar) = '\0';
249 --cp;
250 kdb_printf("\b%s \r", cp);
251 tmp = *cp;
252 *cp = '\0';
253 kdb_printf(kdb_prompt_str);
254 kdb_printf("%s", buffer);
255 *cp = tmp;
256 }
257 break;
258 case 13: /* enter */
259 *lastchar++ = '\n';
260 *lastchar++ = '\0';
261 if (!KDB_STATE(KGDB_TRANS)) {
262 KDB_STATE_SET(KGDB_TRANS);
263 kdb_printf("%s", buffer);
264 }
265 kdb_printf("\n");
266 return buffer;
267 case 4: /* Del */
268 if (cp < lastchar) {
269 memcpy(tmpbuffer, cp+1, lastchar - cp - 1);
270 memcpy(cp, tmpbuffer, lastchar - cp - 1);
271 *(--lastchar) = '\0';
272 kdb_printf("%s \r", cp);
273 tmp = *cp;
274 *cp = '\0';
275 kdb_printf(kdb_prompt_str);
276 kdb_printf("%s", buffer);
277 *cp = tmp;
278 }
279 break;
280 case 1: /* Home */
281 if (cp > buffer) {
282 kdb_printf("\r");
283 kdb_printf(kdb_prompt_str);
284 cp = buffer;
285 }
286 break;
287 case 5: /* End */
288 if (cp < lastchar) {
289 kdb_printf("%s", cp);
290 cp = lastchar;
291 }
292 break;
293 case 2: /* Left */
294 if (cp > buffer) {
295 kdb_printf("\b");
296 --cp;
297 }
298 break;
299 case 14: /* Down */
300 memset(tmpbuffer, ' ',
301 strlen(kdb_prompt_str) + (lastchar-buffer));
302 *(tmpbuffer+strlen(kdb_prompt_str) +
303 (lastchar-buffer)) = '\0';
304 kdb_printf("\r%s\r", tmpbuffer);
305 *lastchar = (char)key;
306 *(lastchar+1) = '\0';
307 return lastchar;
308 case 6: /* Right */
309 if (cp < lastchar) {
310 kdb_printf("%c", *cp);
311 ++cp;
312 }
313 break;
314 case 16: /* Up */
315 memset(tmpbuffer, ' ',
316 strlen(kdb_prompt_str) + (lastchar-buffer));
317 *(tmpbuffer+strlen(kdb_prompt_str) +
318 (lastchar-buffer)) = '\0';
319 kdb_printf("\r%s\r", tmpbuffer);
320 *lastchar = (char)key;
321 *(lastchar+1) = '\0';
322 return lastchar;
323 case 9: /* Tab */
324 if (tab < 2)
325 ++tab;
326 p_tmp = buffer;
327 while (*p_tmp == ' ')
328 p_tmp++;
329 if (p_tmp > cp)
330 break;
331 memcpy(tmpbuffer, p_tmp, cp-p_tmp);
332 *(tmpbuffer + (cp-p_tmp)) = '\0';
333 p_tmp = strrchr(tmpbuffer, ' ');
334 if (p_tmp)
335 ++p_tmp;
336 else
337 p_tmp = tmpbuffer;
338 len = strlen(p_tmp);
339 count = kallsyms_symbol_complete(p_tmp,
340 sizeof(tmpbuffer) -
341 (p_tmp - tmpbuffer));
342 if (tab == 2 && count > 0) {
343 kdb_printf("\n%d symbols are found.", count);
344 if (count > dtab_count) {
345 count = dtab_count;
346 kdb_printf(" But only first %d symbols will"
347 " be printed.\nYou can change the"
348 " environment variable DTABCOUNT.",
349 count);
350 }
351 kdb_printf("\n");
352 for (i = 0; i < count; i++) {
353 if (WARN_ON(!kallsyms_symbol_next(p_tmp, i)))
354 break;
355 kdb_printf("%s ", p_tmp);
356 *(p_tmp + len) = '\0';
357 }
358 if (i >= dtab_count)
359 kdb_printf("...");
360 kdb_printf("\n");
361 kdb_printf(kdb_prompt_str);
362 kdb_printf("%s", buffer);
363 } else if (tab != 2 && count > 0) {
364 len_tmp = strlen(p_tmp);
365 strncpy(p_tmp+len_tmp, cp, lastchar-cp+1);
366 len_tmp = strlen(p_tmp);
367 strncpy(cp, p_tmp+len, len_tmp-len + 1);
368 len = len_tmp - len;
369 kdb_printf("%s", cp);
370 cp += len;
371 lastchar += len;
372 }
373 kdb_nextline = 1; /* reset output line number */
374 break;
375 default:
376 if (key >= 32 && lastchar < bufend) {
377 if (cp < lastchar) {
378 memcpy(tmpbuffer, cp, lastchar - cp);
379 memcpy(cp+1, tmpbuffer, lastchar - cp);
380 *++lastchar = '\0';
381 *cp = key;
382 kdb_printf("%s\r", cp);
383 ++cp;
384 tmp = *cp;
385 *cp = '\0';
386 kdb_printf(kdb_prompt_str);
387 kdb_printf("%s", buffer);
388 *cp = tmp;
389 } else {
390 *++lastchar = '\0';
391 *cp++ = key;
392 /* The kgdb transition check will hide
393 * printed characters if we think that
394 * kgdb is connecting, until the check
395 * fails */
396 if (!KDB_STATE(KGDB_TRANS)) {
397 if (kgdb_transition_check(buffer))
398 return buffer;
399 } else {
400 kdb_printf("%c", key);
401 }
402 }
403 /* Special escape to kgdb */
404 if (lastchar - buffer >= 5 &&
405 strcmp(lastchar - 5, "$?#3f") == 0) {
406 kdb_gdb_state_pass(lastchar - 5);
407 strcpy(buffer, "kgdb");
408 KDB_STATE_SET(DOING_KGDB);
409 return buffer;
410 }
411 if (lastchar - buffer >= 11 &&
412 strcmp(lastchar - 11, "$qSupported") == 0) {
413 kdb_gdb_state_pass(lastchar - 11);
414 strcpy(buffer, "kgdb");
415 KDB_STATE_SET(DOING_KGDB);
416 return buffer;
417 }
418 }
419 break;
420 }
421 goto poll_again;
422}
423
424/*
425 * kdb_getstr
426 *
427 * Print the prompt string and read a command from the
428 * input device.
429 *
430 * Parameters:
431 * buffer Address of buffer to receive command
432 * bufsize Size of buffer in bytes
433 * prompt Pointer to string to use as prompt string
434 * Returns:
435 * Pointer to command buffer.
436 * Locking:
437 * None.
438 * Remarks:
439 * For SMP kernels, the processor number will be
440 * substituted for %d, %x or %o in the prompt.
441 */
442
443char *kdb_getstr(char *buffer, size_t bufsize, const char *prompt)
444{
445 if (prompt && kdb_prompt_str != prompt)
446 strncpy(kdb_prompt_str, prompt, CMD_BUFLEN);
447 kdb_printf(kdb_prompt_str);
448 kdb_nextline = 1; /* Prompt and input resets line number */
449 return kdb_read(buffer, bufsize);
450}
451
452/*
453 * kdb_input_flush
454 *
455 * Get rid of any buffered console input.
456 *
457 * Parameters:
458 * none
459 * Returns:
460 * nothing
461 * Locking:
462 * none
463 * Remarks:
464 * Call this function whenever you want to flush input. If there is any
465 * outstanding input, it ignores all characters until there has been no
466 * data for approximately 1ms.
467 */
468
469static void kdb_input_flush(void)
470{
471 get_char_func *f;
472 int res;
473 int flush_delay = 1;
474 while (flush_delay) {
475 flush_delay--;
476empty:
477 touch_nmi_watchdog();
478 for (f = &kdb_poll_funcs[0]; *f; ++f) {
479 res = (*f)();
480 if (res != -1) {
481 flush_delay = 1;
482 goto empty;
483 }
484 }
485 if (flush_delay)
486 mdelay(1);
487 }
488}
489
490/*
491 * kdb_printf
492 *
493 * Print a string to the output device(s).
494 *
495 * Parameters:
496 * printf-like format and optional args.
497 * Returns:
498 * 0
499 * Locking:
500 * None.
501 * Remarks:
502 * use 'kdbcons->write()' to avoid polluting 'log_buf' with
503 * kdb output.
504 *
505 * If the user is doing a cmd args | grep srch
506 * then kdb_grepping_flag is set.
507 * In that case we need to accumulate full lines (ending in \n) before
508 * searching for the pattern.
509 */
510
511static char kdb_buffer[256]; /* A bit too big to go on stack */
512static char *next_avail = kdb_buffer;
513static int size_avail;
514static int suspend_grep;
515
516/*
517 * search arg1 to see if it contains arg2
518 * (kdmain.c provides flags for ^pat and pat$)
519 *
520 * return 1 for found, 0 for not found
521 */
522static int kdb_search_string(char *searched, char *searchfor)
523{
524 char firstchar, *cp;
525 int len1, len2;
526
527 /* not counting the newline at the end of "searched" */
528 len1 = strlen(searched)-1;
529 len2 = strlen(searchfor);
530 if (len1 < len2)
531 return 0;
532 if (kdb_grep_leading && kdb_grep_trailing && len1 != len2)
533 return 0;
534 if (kdb_grep_leading) {
535 if (!strncmp(searched, searchfor, len2))
536 return 1;
537 } else if (kdb_grep_trailing) {
538 if (!strncmp(searched+len1-len2, searchfor, len2))
539 return 1;
540 } else {
541 firstchar = *searchfor;
542 cp = searched;
543 while ((cp = strchr(cp, firstchar))) {
544 if (!strncmp(cp, searchfor, len2))
545 return 1;
546 cp++;
547 }
548 }
549 return 0;
550}
551
552int vkdb_printf(enum kdb_msgsrc src, const char *fmt, va_list ap)
553{
554 int diag;
555 int linecount;
556 int colcount;
557 int logging, saved_loglevel = 0;
558 int retlen = 0;
559 int fnd, len;
560 int this_cpu, old_cpu;
561 char *cp, *cp2, *cphold = NULL, replaced_byte = ' ';
562 char *moreprompt = "more> ";
563 struct console *c = console_drivers;
564 unsigned long uninitialized_var(flags);
565
566 /* Serialize kdb_printf if multiple cpus try to write at once.
567 * But if any cpu goes recursive in kdb, just print the output,
568 * even if it is interleaved with any other text.
569 */
570 local_irq_save(flags);
571 this_cpu = smp_processor_id();
572 for (;;) {
573 old_cpu = cmpxchg(&kdb_printf_cpu, -1, this_cpu);
574 if (old_cpu == -1 || old_cpu == this_cpu)
575 break;
576
577 cpu_relax();
578 }
579
580 diag = kdbgetintenv("LINES", &linecount);
581 if (diag || linecount <= 1)
582 linecount = 24;
583
584 diag = kdbgetintenv("COLUMNS", &colcount);
585 if (diag || colcount <= 1)
586 colcount = 80;
587
588 diag = kdbgetintenv("LOGGING", &logging);
589 if (diag)
590 logging = 0;
591
592 if (!kdb_grepping_flag || suspend_grep) {
593 /* normally, every vsnprintf starts a new buffer */
594 next_avail = kdb_buffer;
595 size_avail = sizeof(kdb_buffer);
596 }
597 vsnprintf(next_avail, size_avail, fmt, ap);
598
599 /*
600 * If kdb_parse() found that the command was cmd xxx | grep yyy
601 * then kdb_grepping_flag is set, and kdb_grep_string contains yyy
602 *
603 * Accumulate the print data up to a newline before searching it.
604 * (vsnprintf does null-terminate the string that it generates)
605 */
606
607 /* skip the search if prints are temporarily unconditional */
608 if (!suspend_grep && kdb_grepping_flag) {
609 cp = strchr(kdb_buffer, '\n');
610 if (!cp) {
611 /*
612 * Special cases that don't end with newlines
613 * but should be written without one:
614 * The "[nn]kdb> " prompt should
615 * appear at the front of the buffer.
616 *
617 * The "[nn]more " prompt should also be
618 * (MOREPROMPT -> moreprompt)
619 * written * but we print that ourselves,
620 * we set the suspend_grep flag to make
621 * it unconditional.
622 *
623 */
624 if (next_avail == kdb_buffer) {
625 /*
626 * these should occur after a newline,
627 * so they will be at the front of the
628 * buffer
629 */
630 cp2 = kdb_buffer;
631 len = strlen(kdb_prompt_str);
632 if (!strncmp(cp2, kdb_prompt_str, len)) {
633 /*
634 * We're about to start a new
635 * command, so we can go back
636 * to normal mode.
637 */
638 kdb_grepping_flag = 0;
639 goto kdb_printit;
640 }
641 }
642 /* no newline; don't search/write the buffer
643 until one is there */
644 len = strlen(kdb_buffer);
645 next_avail = kdb_buffer + len;
646 size_avail = sizeof(kdb_buffer) - len;
647 goto kdb_print_out;
648 }
649
650 /*
651 * The newline is present; print through it or discard
652 * it, depending on the results of the search.
653 */
654 cp++; /* to byte after the newline */
655 replaced_byte = *cp; /* remember what/where it was */
656 cphold = cp;
657 *cp = '\0'; /* end the string for our search */
658
659 /*
660 * We now have a newline at the end of the string
661 * Only continue with this output if it contains the
662 * search string.
663 */
664 fnd = kdb_search_string(kdb_buffer, kdb_grep_string);
665 if (!fnd) {
666 /*
667 * At this point the complete line at the start
668 * of kdb_buffer can be discarded, as it does
669 * not contain what the user is looking for.
670 * Shift the buffer left.
671 */
672 *cphold = replaced_byte;
673 strcpy(kdb_buffer, cphold);
674 len = strlen(kdb_buffer);
675 next_avail = kdb_buffer + len;
676 size_avail = sizeof(kdb_buffer) - len;
677 goto kdb_print_out;
678 }
679 if (kdb_grepping_flag >= KDB_GREPPING_FLAG_SEARCH)
680 /*
681 * This was a interactive search (using '/' at more
682 * prompt) and it has completed. Clear the flag.
683 */
684 kdb_grepping_flag = 0;
685 /*
686 * at this point the string is a full line and
687 * should be printed, up to the null.
688 */
689 }
690kdb_printit:
691
692 /*
693 * Write to all consoles.
694 */
695 retlen = strlen(kdb_buffer);
696 cp = (char *) printk_skip_headers(kdb_buffer);
697 if (!dbg_kdb_mode && kgdb_connected) {
698 gdbstub_msg_write(cp, retlen - (cp - kdb_buffer));
699 } else {
700 if (dbg_io_ops && !dbg_io_ops->is_console) {
701 len = retlen - (cp - kdb_buffer);
702 cp2 = cp;
703 while (len--) {
704 dbg_io_ops->write_char(*cp2);
705 cp2++;
706 }
707 }
708 while (c) {
709 c->write(c, cp, retlen - (cp - kdb_buffer));
710 touch_nmi_watchdog();
711 c = c->next;
712 }
713 }
714 if (logging) {
715 saved_loglevel = console_loglevel;
716 console_loglevel = CONSOLE_LOGLEVEL_SILENT;
717 if (printk_get_level(kdb_buffer) || src == KDB_MSGSRC_PRINTK)
718 printk("%s", kdb_buffer);
719 else
720 pr_info("%s", kdb_buffer);
721 }
722
723 if (KDB_STATE(PAGER)) {
724 /*
725 * Check printed string to decide how to bump the
726 * kdb_nextline to control when the more prompt should
727 * show up.
728 */
729 int got = 0;
730 len = retlen;
731 while (len--) {
732 if (kdb_buffer[len] == '\n') {
733 kdb_nextline++;
734 got = 0;
735 } else if (kdb_buffer[len] == '\r') {
736 got = 0;
737 } else {
738 got++;
739 }
740 }
741 kdb_nextline += got / (colcount + 1);
742 }
743
744 /* check for having reached the LINES number of printed lines */
745 if (kdb_nextline >= linecount) {
746 char buf1[16] = "";
747
748 /* Watch out for recursion here. Any routine that calls
749 * kdb_printf will come back through here. And kdb_read
750 * uses kdb_printf to echo on serial consoles ...
751 */
752 kdb_nextline = 1; /* In case of recursion */
753
754 /*
755 * Pause until cr.
756 */
757 moreprompt = kdbgetenv("MOREPROMPT");
758 if (moreprompt == NULL)
759 moreprompt = "more> ";
760
761 kdb_input_flush();
762 c = console_drivers;
763
764 if (dbg_io_ops && !dbg_io_ops->is_console) {
765 len = strlen(moreprompt);
766 cp = moreprompt;
767 while (len--) {
768 dbg_io_ops->write_char(*cp);
769 cp++;
770 }
771 }
772 while (c) {
773 c->write(c, moreprompt, strlen(moreprompt));
774 touch_nmi_watchdog();
775 c = c->next;
776 }
777
778 if (logging)
779 printk("%s", moreprompt);
780
781 kdb_read(buf1, 2); /* '2' indicates to return
782 * immediately after getting one key. */
783 kdb_nextline = 1; /* Really set output line 1 */
784
785 /* empty and reset the buffer: */
786 kdb_buffer[0] = '\0';
787 next_avail = kdb_buffer;
788 size_avail = sizeof(kdb_buffer);
789 if ((buf1[0] == 'q') || (buf1[0] == 'Q')) {
790 /* user hit q or Q */
791 KDB_FLAG_SET(CMD_INTERRUPT); /* command interrupted */
792 KDB_STATE_CLEAR(PAGER);
793 /* end of command output; back to normal mode */
794 kdb_grepping_flag = 0;
795 kdb_printf("\n");
796 } else if (buf1[0] == ' ') {
797 kdb_printf("\r");
798 suspend_grep = 1; /* for this recursion */
799 } else if (buf1[0] == '\n') {
800 kdb_nextline = linecount - 1;
801 kdb_printf("\r");
802 suspend_grep = 1; /* for this recursion */
803 } else if (buf1[0] == '/' && !kdb_grepping_flag) {
804 kdb_printf("\r");
805 kdb_getstr(kdb_grep_string, KDB_GREP_STRLEN,
806 kdbgetenv("SEARCHPROMPT") ?: "search> ");
807 *strchrnul(kdb_grep_string, '\n') = '\0';
808 kdb_grepping_flag += KDB_GREPPING_FLAG_SEARCH;
809 suspend_grep = 1; /* for this recursion */
810 } else if (buf1[0] && buf1[0] != '\n') {
811 /* user hit something other than enter */
812 suspend_grep = 1; /* for this recursion */
813 if (buf1[0] != '/')
814 kdb_printf(
815 "\nOnly 'q', 'Q' or '/' are processed at "
816 "more prompt, input ignored\n");
817 else
818 kdb_printf("\n'/' cannot be used during | "
819 "grep filtering, input ignored\n");
820 } else if (kdb_grepping_flag) {
821 /* user hit enter */
822 suspend_grep = 1; /* for this recursion */
823 kdb_printf("\n");
824 }
825 kdb_input_flush();
826 }
827
828 /*
829 * For grep searches, shift the printed string left.
830 * replaced_byte contains the character that was overwritten with
831 * the terminating null, and cphold points to the null.
832 * Then adjust the notion of available space in the buffer.
833 */
834 if (kdb_grepping_flag && !suspend_grep) {
835 *cphold = replaced_byte;
836 strcpy(kdb_buffer, cphold);
837 len = strlen(kdb_buffer);
838 next_avail = kdb_buffer + len;
839 size_avail = sizeof(kdb_buffer) - len;
840 }
841
842kdb_print_out:
843 suspend_grep = 0; /* end of what may have been a recursive call */
844 if (logging)
845 console_loglevel = saved_loglevel;
846 /* kdb_printf_cpu locked the code above. */
847 smp_store_release(&kdb_printf_cpu, old_cpu);
848 local_irq_restore(flags);
849 return retlen;
850}
851
852int kdb_printf(const char *fmt, ...)
853{
854 va_list ap;
855 int r;
856
857 va_start(ap, fmt);
858 r = vkdb_printf(KDB_MSGSRC_INTERNAL, fmt, ap);
859 va_end(ap);
860
861 return r;
862}
863EXPORT_SYMBOL_GPL(kdb_printf);