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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/types.h>
13#include <linux/ctype.h>
14#include <linux/kernel.h>
15#include <linux/init.h>
16#include <linux/kdev_t.h>
17#include <linux/console.h>
18#include <linux/string.h>
19#include <linux/sched.h>
20#include <linux/smp.h>
21#include <linux/nmi.h>
22#include <linux/delay.h>
23#include <linux/kgdb.h>
24#include <linux/kdb.h>
25#include <linux/kallsyms.h>
26#include "kdb_private.h"
27
28#define CMD_BUFLEN 256
29char kdb_prompt_str[CMD_BUFLEN];
30
31int kdb_trap_printk;
32int kdb_printf_cpu = -1;
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
51/**
52 * kdb_handle_escape() - validity check on an accumulated escape sequence.
53 * @buf: Accumulated escape characters to be examined. Note that buf
54 * is not a string, it is an array of characters and need not be
55 * nil terminated.
56 * @sz: Number of accumulated escape characters.
57 *
58 * Return: -1 if the escape sequence is unwanted, 0 if it is incomplete,
59 * otherwise it returns a mapped key value to pass to the upper layers.
60 */
61static int kdb_handle_escape(char *buf, size_t sz)
62{
63 char *lastkey = buf + sz - 1;
64
65 switch (sz) {
66 case 1:
67 if (*lastkey == '\e')
68 return 0;
69 break;
70
71 case 2: /* \e<something> */
72 if (*lastkey == '[')
73 return 0;
74 break;
75
76 case 3:
77 switch (*lastkey) {
78 case 'A': /* \e[A, up arrow */
79 return 16;
80 case 'B': /* \e[B, down arrow */
81 return 14;
82 case 'C': /* \e[C, right arrow */
83 return 6;
84 case 'D': /* \e[D, left arrow */
85 return 2;
86 case '1': /* \e[<1,3,4>], may be home, del, end */
87 case '3':
88 case '4':
89 return 0;
90 }
91 break;
92
93 case 4:
94 if (*lastkey == '~') {
95 switch (buf[2]) {
96 case '1': /* \e[1~, home */
97 return 1;
98 case '3': /* \e[3~, del */
99 return 4;
100 case '4': /* \e[4~, end */
101 return 5;
102 }
103 }
104 break;
105 }
106
107 return -1;
108}
109
110/**
111 * kdb_getchar() - Read a single character from a kdb console (or consoles).
112 *
113 * Other than polling the various consoles that are currently enabled,
114 * most of the work done in this function is dealing with escape sequences.
115 *
116 * An escape key could be the start of a vt100 control sequence such as \e[D
117 * (left arrow) or it could be a character in its own right. The standard
118 * method for detecting the difference is to wait for 2 seconds to see if there
119 * are any other characters. kdb is complicated by the lack of a timer service
120 * (interrupts are off), by multiple input sources. Escape sequence processing
121 * has to be done as states in the polling loop.
122 *
123 * Return: The key pressed or a control code derived from an escape sequence.
124 */
125char kdb_getchar(void)
126{
127#define ESCAPE_UDELAY 1000
128#define ESCAPE_DELAY (2*1000000/ESCAPE_UDELAY) /* 2 seconds worth of udelays */
129 char buf[4]; /* longest vt100 escape sequence is 4 bytes */
130 char *pbuf = buf;
131 int escape_delay = 0;
132 get_char_func *f, *f_prev = NULL;
133 int key;
134 static bool last_char_was_cr;
135
136 for (f = &kdb_poll_funcs[0]; ; ++f) {
137 if (*f == NULL) {
138 /* Reset NMI watchdog once per poll loop */
139 touch_nmi_watchdog();
140 f = &kdb_poll_funcs[0];
141 }
142
143 key = (*f)();
144 if (key == -1) {
145 if (escape_delay) {
146 udelay(ESCAPE_UDELAY);
147 if (--escape_delay == 0)
148 return '\e';
149 }
150 continue;
151 }
152
153 /*
154 * The caller expects that newlines are either CR or LF. However
155 * some terminals send _both_ CR and LF. Avoid having to handle
156 * this in the caller by stripping the LF if we saw a CR right
157 * before.
158 */
159 if (last_char_was_cr && key == '\n') {
160 last_char_was_cr = false;
161 continue;
162 }
163 last_char_was_cr = (key == '\r');
164
165 /*
166 * When the first character is received (or we get a change
167 * input source) we set ourselves up to handle an escape
168 * sequences (just in case).
169 */
170 if (f_prev != f) {
171 f_prev = f;
172 pbuf = buf;
173 escape_delay = ESCAPE_DELAY;
174 }
175
176 *pbuf++ = key;
177 key = kdb_handle_escape(buf, pbuf - buf);
178 if (key < 0) /* no escape sequence; return best character */
179 return buf[pbuf - buf == 2 ? 1 : 0];
180 if (key > 0)
181 return key;
182 }
183
184 unreachable();
185}
186
187/**
188 * kdb_position_cursor() - Place cursor in the correct horizontal position
189 * @prompt: Nil-terminated string containing the prompt string
190 * @buffer: Nil-terminated string containing the entire command line
191 * @cp: Cursor position, pointer the character in buffer where the cursor
192 * should be positioned.
193 *
194 * The cursor is positioned by sending a carriage-return and then printing
195 * the content of the line until we reach the correct cursor position.
196 *
197 * There is some additional fine detail here.
198 *
199 * Firstly, even though kdb_printf() will correctly format zero-width fields
200 * we want the second call to kdb_printf() to be conditional. That keeps things
201 * a little cleaner when LOGGING=1.
202 *
203 * Secondly, we can't combine everything into one call to kdb_printf() since
204 * that renders into a fixed length buffer and the combined print could result
205 * in unwanted truncation.
206 */
207static void kdb_position_cursor(char *prompt, char *buffer, char *cp)
208{
209 kdb_printf("\r%s", prompt);
210 if (cp > buffer)
211 kdb_printf("%.*s", (int)(cp - buffer), buffer);
212}
213
214/*
215 * kdb_read
216 *
217 * This function reads a string of characters, terminated by
218 * a newline, or by reaching the end of the supplied buffer,
219 * from the current kernel debugger console device.
220 * Parameters:
221 * buffer - Address of character buffer to receive input characters.
222 * bufsize - size, in bytes, of the character buffer
223 * Returns:
224 * Returns a pointer to the buffer containing the received
225 * character string. This string will be terminated by a
226 * newline character.
227 * Locking:
228 * No locks are required to be held upon entry to this
229 * function. It is not reentrant - it relies on the fact
230 * that while kdb is running on only one "master debug" cpu.
231 * Remarks:
232 * The buffer size must be >= 2.
233 */
234
235static char *kdb_read(char *buffer, size_t bufsize)
236{
237 char *cp = buffer;
238 char *bufend = buffer+bufsize-2; /* Reserve space for newline
239 * and null byte */
240 char *lastchar;
241 char *p_tmp;
242 char tmp;
243 static char tmpbuffer[CMD_BUFLEN];
244 int len = strlen(buffer);
245 int len_tmp;
246 int tab = 0;
247 int count;
248 int i;
249 int diag, dtab_count;
250 int key, ret;
251
252 diag = kdbgetintenv("DTABCOUNT", &dtab_count);
253 if (diag)
254 dtab_count = 30;
255
256 if (len > 0) {
257 cp += len;
258 if (*(buffer+len-1) == '\n')
259 cp--;
260 }
261
262 lastchar = cp;
263 *cp = '\0';
264 kdb_printf("%s", buffer);
265poll_again:
266 key = kdb_getchar();
267 if (key != 9)
268 tab = 0;
269 switch (key) {
270 case 8: /* backspace */
271 if (cp > buffer) {
272 memmove(cp-1, cp, lastchar - cp + 1);
273 lastchar--;
274 cp--;
275 kdb_printf("\b%s ", cp);
276 kdb_position_cursor(kdb_prompt_str, buffer, cp);
277 }
278 break;
279 case 10: /* linefeed */
280 case 13: /* carriage return */
281 *lastchar++ = '\n';
282 *lastchar++ = '\0';
283 if (!KDB_STATE(KGDB_TRANS)) {
284 KDB_STATE_SET(KGDB_TRANS);
285 kdb_printf("%s", buffer);
286 }
287 kdb_printf("\n");
288 return buffer;
289 case 4: /* Del */
290 if (cp < lastchar) {
291 memmove(cp, cp+1, lastchar - cp);
292 lastchar--;
293 kdb_printf("%s ", cp);
294 kdb_position_cursor(kdb_prompt_str, buffer, cp);
295 }
296 break;
297 case 1: /* Home */
298 if (cp > buffer) {
299 cp = buffer;
300 kdb_position_cursor(kdb_prompt_str, buffer, cp);
301 }
302 break;
303 case 5: /* End */
304 if (cp < lastchar) {
305 kdb_printf("%s", cp);
306 cp = lastchar;
307 }
308 break;
309 case 2: /* Left */
310 if (cp > buffer) {
311 kdb_printf("\b");
312 --cp;
313 }
314 break;
315 case 14: /* Down */
316 case 16: /* Up */
317 kdb_printf("\r%*c\r",
318 (int)(strlen(kdb_prompt_str) + (lastchar - buffer)),
319 ' ');
320 *lastchar = (char)key;
321 *(lastchar+1) = '\0';
322 return lastchar;
323 case 6: /* Right */
324 if (cp < lastchar) {
325 kdb_printf("%c", *cp);
326 ++cp;
327 }
328 break;
329 case 9: /* Tab */
330 if (tab < 2)
331 ++tab;
332
333 tmp = *cp;
334 *cp = '\0';
335 p_tmp = strrchr(buffer, ' ');
336 p_tmp = (p_tmp ? p_tmp + 1 : buffer);
337 strscpy(tmpbuffer, p_tmp, sizeof(tmpbuffer));
338 *cp = tmp;
339
340 len = strlen(tmpbuffer);
341 count = kallsyms_symbol_complete(tmpbuffer, sizeof(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 ret = kallsyms_symbol_next(tmpbuffer, i, sizeof(tmpbuffer));
354 if (WARN_ON(!ret))
355 break;
356 if (ret != -E2BIG)
357 kdb_printf("%s ", tmpbuffer);
358 else
359 kdb_printf("%s... ", tmpbuffer);
360 tmpbuffer[len] = '\0';
361 }
362 if (i >= dtab_count)
363 kdb_printf("...");
364 kdb_printf("\n");
365 kdb_printf("%s", kdb_prompt_str);
366 kdb_printf("%s", buffer);
367 if (cp != lastchar)
368 kdb_position_cursor(kdb_prompt_str, buffer, cp);
369 } else if (tab != 2 && count > 0) {
370 /* How many new characters do we want from tmpbuffer? */
371 len_tmp = strlen(tmpbuffer) - len;
372 if (lastchar + len_tmp >= bufend)
373 len_tmp = bufend - lastchar;
374
375 if (len_tmp) {
376 /* + 1 ensures the '\0' is memmove'd */
377 memmove(cp+len_tmp, cp, (lastchar-cp) + 1);
378 memcpy(cp, tmpbuffer+len, len_tmp);
379 kdb_printf("%s", cp);
380 cp += len_tmp;
381 lastchar += len_tmp;
382 if (cp != lastchar)
383 kdb_position_cursor(kdb_prompt_str,
384 buffer, cp);
385 }
386 }
387 kdb_nextline = 1; /* reset output line number */
388 break;
389 default:
390 if (key >= 32 && lastchar < bufend) {
391 if (cp < lastchar) {
392 memmove(cp+1, cp, lastchar - cp + 1);
393 lastchar++;
394 *cp = key;
395 kdb_printf("%s", cp);
396 ++cp;
397 kdb_position_cursor(kdb_prompt_str, buffer, cp);
398 } else {
399 *++lastchar = '\0';
400 *cp++ = key;
401 /* The kgdb transition check will hide
402 * printed characters if we think that
403 * kgdb is connecting, until the check
404 * fails */
405 if (!KDB_STATE(KGDB_TRANS)) {
406 if (kgdb_transition_check(buffer))
407 return buffer;
408 } else {
409 kdb_printf("%c", key);
410 }
411 }
412 /* Special escape to kgdb */
413 if (lastchar - buffer >= 5 &&
414 strcmp(lastchar - 5, "$?#3f") == 0) {
415 kdb_gdb_state_pass(lastchar - 5);
416 strcpy(buffer, "kgdb");
417 KDB_STATE_SET(DOING_KGDB);
418 return buffer;
419 }
420 if (lastchar - buffer >= 11 &&
421 strcmp(lastchar - 11, "$qSupported") == 0) {
422 kdb_gdb_state_pass(lastchar - 11);
423 strcpy(buffer, "kgdb");
424 KDB_STATE_SET(DOING_KGDB);
425 return buffer;
426 }
427 }
428 break;
429 }
430 goto poll_again;
431}
432
433/*
434 * kdb_getstr
435 *
436 * Print the prompt string and read a command from the
437 * input device.
438 *
439 * Parameters:
440 * buffer Address of buffer to receive command
441 * bufsize Size of buffer in bytes
442 * prompt Pointer to string to use as prompt string
443 * Returns:
444 * Pointer to command buffer.
445 * Locking:
446 * None.
447 * Remarks:
448 * For SMP kernels, the processor number will be
449 * substituted for %d, %x or %o in the prompt.
450 */
451
452char *kdb_getstr(char *buffer, size_t bufsize, const char *prompt)
453{
454 if (prompt && kdb_prompt_str != prompt)
455 strscpy(kdb_prompt_str, prompt, CMD_BUFLEN);
456 kdb_printf("%s", kdb_prompt_str);
457 kdb_nextline = 1; /* Prompt and input resets line number */
458 return kdb_read(buffer, bufsize);
459}
460
461/*
462 * kdb_input_flush
463 *
464 * Get rid of any buffered console input.
465 *
466 * Parameters:
467 * none
468 * Returns:
469 * nothing
470 * Locking:
471 * none
472 * Remarks:
473 * Call this function whenever you want to flush input. If there is any
474 * outstanding input, it ignores all characters until there has been no
475 * data for approximately 1ms.
476 */
477
478static void kdb_input_flush(void)
479{
480 get_char_func *f;
481 int res;
482 int flush_delay = 1;
483 while (flush_delay) {
484 flush_delay--;
485empty:
486 touch_nmi_watchdog();
487 for (f = &kdb_poll_funcs[0]; *f; ++f) {
488 res = (*f)();
489 if (res != -1) {
490 flush_delay = 1;
491 goto empty;
492 }
493 }
494 if (flush_delay)
495 mdelay(1);
496 }
497}
498
499/*
500 * kdb_printf
501 *
502 * Print a string to the output device(s).
503 *
504 * Parameters:
505 * printf-like format and optional args.
506 * Returns:
507 * 0
508 * Locking:
509 * None.
510 * Remarks:
511 * use 'kdbcons->write()' to avoid polluting 'log_buf' with
512 * kdb output.
513 *
514 * If the user is doing a cmd args | grep srch
515 * then kdb_grepping_flag is set.
516 * In that case we need to accumulate full lines (ending in \n) before
517 * searching for the pattern.
518 */
519
520static char kdb_buffer[256]; /* A bit too big to go on stack */
521static char *next_avail = kdb_buffer;
522static int size_avail;
523static int suspend_grep;
524
525/*
526 * search arg1 to see if it contains arg2
527 * (kdmain.c provides flags for ^pat and pat$)
528 *
529 * return 1 for found, 0 for not found
530 */
531static int kdb_search_string(char *searched, char *searchfor)
532{
533 char firstchar, *cp;
534 int len1, len2;
535
536 /* not counting the newline at the end of "searched" */
537 len1 = strlen(searched)-1;
538 len2 = strlen(searchfor);
539 if (len1 < len2)
540 return 0;
541 if (kdb_grep_leading && kdb_grep_trailing && len1 != len2)
542 return 0;
543 if (kdb_grep_leading) {
544 if (!strncmp(searched, searchfor, len2))
545 return 1;
546 } else if (kdb_grep_trailing) {
547 if (!strncmp(searched+len1-len2, searchfor, len2))
548 return 1;
549 } else {
550 firstchar = *searchfor;
551 cp = searched;
552 while ((cp = strchr(cp, firstchar))) {
553 if (!strncmp(cp, searchfor, len2))
554 return 1;
555 cp++;
556 }
557 }
558 return 0;
559}
560
561static void kdb_msg_write(const char *msg, int msg_len)
562{
563 struct console *c;
564 const char *cp;
565 int cookie;
566 int len;
567
568 if (msg_len == 0)
569 return;
570
571 cp = msg;
572 len = msg_len;
573
574 while (len--) {
575 dbg_io_ops->write_char(*cp);
576 cp++;
577 }
578
579 /*
580 * The console_srcu_read_lock() only provides safe console list
581 * traversal. The use of the ->write() callback relies on all other
582 * CPUs being stopped at the moment and console drivers being able to
583 * handle reentrance when @oops_in_progress is set.
584 *
585 * There is no guarantee that every console driver can handle
586 * reentrance in this way; the developer deploying the debugger
587 * is responsible for ensuring that the console drivers they
588 * have selected handle reentrance appropriately.
589 */
590 cookie = console_srcu_read_lock();
591 for_each_console_srcu(c) {
592 if (!(console_srcu_read_flags(c) & CON_ENABLED))
593 continue;
594 if (c == dbg_io_ops->cons)
595 continue;
596 if (!c->write)
597 continue;
598 /*
599 * Set oops_in_progress to encourage the console drivers to
600 * disregard their internal spin locks: in the current calling
601 * context the risk of deadlock is a bigger problem than risks
602 * due to re-entering the console driver. We operate directly on
603 * oops_in_progress rather than using bust_spinlocks() because
604 * the calls bust_spinlocks() makes on exit are not appropriate
605 * for this calling context.
606 */
607 ++oops_in_progress;
608 c->write(c, msg, msg_len);
609 --oops_in_progress;
610 touch_nmi_watchdog();
611 }
612 console_srcu_read_unlock(cookie);
613}
614
615int vkdb_printf(enum kdb_msgsrc src, const char *fmt, va_list ap)
616{
617 int diag;
618 int linecount;
619 int colcount;
620 int logging, saved_loglevel = 0;
621 int retlen = 0;
622 int fnd, len;
623 int this_cpu, old_cpu;
624 char *cp, *cp2, *cphold = NULL, replaced_byte = ' ';
625 char *moreprompt = "more> ";
626 unsigned long flags;
627
628 /* Serialize kdb_printf if multiple cpus try to write at once.
629 * But if any cpu goes recursive in kdb, just print the output,
630 * even if it is interleaved with any other text.
631 */
632 local_irq_save(flags);
633 this_cpu = smp_processor_id();
634 for (;;) {
635 old_cpu = cmpxchg(&kdb_printf_cpu, -1, this_cpu);
636 if (old_cpu == -1 || old_cpu == this_cpu)
637 break;
638
639 cpu_relax();
640 }
641
642 diag = kdbgetintenv("LINES", &linecount);
643 if (diag || linecount <= 1)
644 linecount = 24;
645
646 diag = kdbgetintenv("COLUMNS", &colcount);
647 if (diag || colcount <= 1)
648 colcount = 80;
649
650 diag = kdbgetintenv("LOGGING", &logging);
651 if (diag)
652 logging = 0;
653
654 if (!kdb_grepping_flag || suspend_grep) {
655 /* normally, every vsnprintf starts a new buffer */
656 next_avail = kdb_buffer;
657 size_avail = sizeof(kdb_buffer);
658 }
659 vsnprintf(next_avail, size_avail, fmt, ap);
660
661 /*
662 * If kdb_parse() found that the command was cmd xxx | grep yyy
663 * then kdb_grepping_flag is set, and kdb_grep_string contains yyy
664 *
665 * Accumulate the print data up to a newline before searching it.
666 * (vsnprintf does null-terminate the string that it generates)
667 */
668
669 /* skip the search if prints are temporarily unconditional */
670 if (!suspend_grep && kdb_grepping_flag) {
671 cp = strchr(kdb_buffer, '\n');
672 if (!cp) {
673 /*
674 * Special cases that don't end with newlines
675 * but should be written without one:
676 * The "[nn]kdb> " prompt should
677 * appear at the front of the buffer.
678 *
679 * The "[nn]more " prompt should also be
680 * (MOREPROMPT -> moreprompt)
681 * written * but we print that ourselves,
682 * we set the suspend_grep flag to make
683 * it unconditional.
684 *
685 */
686 if (next_avail == kdb_buffer) {
687 /*
688 * these should occur after a newline,
689 * so they will be at the front of the
690 * buffer
691 */
692 cp2 = kdb_buffer;
693 len = strlen(kdb_prompt_str);
694 if (!strncmp(cp2, kdb_prompt_str, len)) {
695 /*
696 * We're about to start a new
697 * command, so we can go back
698 * to normal mode.
699 */
700 kdb_grepping_flag = 0;
701 goto kdb_printit;
702 }
703 }
704 /* no newline; don't search/write the buffer
705 until one is there */
706 len = strlen(kdb_buffer);
707 next_avail = kdb_buffer + len;
708 size_avail = sizeof(kdb_buffer) - len;
709 goto kdb_print_out;
710 }
711
712 /*
713 * The newline is present; print through it or discard
714 * it, depending on the results of the search.
715 */
716 cp++; /* to byte after the newline */
717 replaced_byte = *cp; /* remember what/where it was */
718 cphold = cp;
719 *cp = '\0'; /* end the string for our search */
720
721 /*
722 * We now have a newline at the end of the string
723 * Only continue with this output if it contains the
724 * search string.
725 */
726 fnd = kdb_search_string(kdb_buffer, kdb_grep_string);
727 if (!fnd) {
728 /*
729 * At this point the complete line at the start
730 * of kdb_buffer can be discarded, as it does
731 * not contain what the user is looking for.
732 * Shift the buffer left.
733 */
734 *cphold = replaced_byte;
735 strcpy(kdb_buffer, cphold);
736 len = strlen(kdb_buffer);
737 next_avail = kdb_buffer + len;
738 size_avail = sizeof(kdb_buffer) - len;
739 goto kdb_print_out;
740 }
741 if (kdb_grepping_flag >= KDB_GREPPING_FLAG_SEARCH) {
742 /*
743 * This was a interactive search (using '/' at more
744 * prompt) and it has completed. Replace the \0 with
745 * its original value to ensure multi-line strings
746 * are handled properly, and return to normal mode.
747 */
748 *cphold = replaced_byte;
749 kdb_grepping_flag = 0;
750 }
751 /*
752 * at this point the string is a full line and
753 * should be printed, up to the null.
754 */
755 }
756kdb_printit:
757
758 /*
759 * Write to all consoles.
760 */
761 retlen = strlen(kdb_buffer);
762 cp = (char *) printk_skip_headers(kdb_buffer);
763 if (!dbg_kdb_mode && kgdb_connected)
764 gdbstub_msg_write(cp, retlen - (cp - kdb_buffer));
765 else
766 kdb_msg_write(cp, retlen - (cp - kdb_buffer));
767
768 if (logging) {
769 saved_loglevel = console_loglevel;
770 console_loglevel = CONSOLE_LOGLEVEL_SILENT;
771 if (printk_get_level(kdb_buffer) || src == KDB_MSGSRC_PRINTK)
772 printk("%s", kdb_buffer);
773 else
774 pr_info("%s", kdb_buffer);
775 }
776
777 if (KDB_STATE(PAGER)) {
778 /*
779 * Check printed string to decide how to bump the
780 * kdb_nextline to control when the more prompt should
781 * show up.
782 */
783 int got = 0;
784 len = retlen;
785 while (len--) {
786 if (kdb_buffer[len] == '\n') {
787 kdb_nextline++;
788 got = 0;
789 } else if (kdb_buffer[len] == '\r') {
790 got = 0;
791 } else {
792 got++;
793 }
794 }
795 kdb_nextline += got / (colcount + 1);
796 }
797
798 /* check for having reached the LINES number of printed lines */
799 if (kdb_nextline >= linecount) {
800 char ch;
801
802 /* Watch out for recursion here. Any routine that calls
803 * kdb_printf will come back through here. And kdb_read
804 * uses kdb_printf to echo on serial consoles ...
805 */
806 kdb_nextline = 1; /* In case of recursion */
807
808 /*
809 * Pause until cr.
810 */
811 moreprompt = kdbgetenv("MOREPROMPT");
812 if (moreprompt == NULL)
813 moreprompt = "more> ";
814
815 kdb_input_flush();
816 kdb_msg_write(moreprompt, strlen(moreprompt));
817
818 if (logging)
819 printk("%s", moreprompt);
820
821 ch = kdb_getchar();
822 kdb_nextline = 1; /* Really set output line 1 */
823
824 /* empty and reset the buffer: */
825 kdb_buffer[0] = '\0';
826 next_avail = kdb_buffer;
827 size_avail = sizeof(kdb_buffer);
828 if ((ch == 'q') || (ch == 'Q')) {
829 /* user hit q or Q */
830 KDB_FLAG_SET(CMD_INTERRUPT); /* command interrupted */
831 KDB_STATE_CLEAR(PAGER);
832 /* end of command output; back to normal mode */
833 kdb_grepping_flag = 0;
834 kdb_printf("\n");
835 } else if (ch == ' ') {
836 kdb_printf("\r");
837 suspend_grep = 1; /* for this recursion */
838 } else if (ch == '\n' || ch == '\r') {
839 kdb_nextline = linecount - 1;
840 kdb_printf("\r");
841 suspend_grep = 1; /* for this recursion */
842 } else if (ch == '/' && !kdb_grepping_flag) {
843 kdb_printf("\r");
844 kdb_getstr(kdb_grep_string, KDB_GREP_STRLEN,
845 kdbgetenv("SEARCHPROMPT") ?: "search> ");
846 *strchrnul(kdb_grep_string, '\n') = '\0';
847 kdb_grepping_flag += KDB_GREPPING_FLAG_SEARCH;
848 suspend_grep = 1; /* for this recursion */
849 } else if (ch) {
850 /* user hit something unexpected */
851 suspend_grep = 1; /* for this recursion */
852 if (ch != '/')
853 kdb_printf(
854 "\nOnly 'q', 'Q' or '/' are processed at "
855 "more prompt, input ignored\n");
856 else
857 kdb_printf("\n'/' cannot be used during | "
858 "grep filtering, input ignored\n");
859 } else if (kdb_grepping_flag) {
860 /* user hit enter */
861 suspend_grep = 1; /* for this recursion */
862 kdb_printf("\n");
863 }
864 kdb_input_flush();
865 }
866
867 /*
868 * For grep searches, shift the printed string left.
869 * replaced_byte contains the character that was overwritten with
870 * the terminating null, and cphold points to the null.
871 * Then adjust the notion of available space in the buffer.
872 */
873 if (kdb_grepping_flag && !suspend_grep) {
874 *cphold = replaced_byte;
875 strcpy(kdb_buffer, cphold);
876 len = strlen(kdb_buffer);
877 next_avail = kdb_buffer + len;
878 size_avail = sizeof(kdb_buffer) - len;
879 }
880
881kdb_print_out:
882 suspend_grep = 0; /* end of what may have been a recursive call */
883 if (logging)
884 console_loglevel = saved_loglevel;
885 /* kdb_printf_cpu locked the code above. */
886 smp_store_release(&kdb_printf_cpu, old_cpu);
887 local_irq_restore(flags);
888 return retlen;
889}
890
891int kdb_printf(const char *fmt, ...)
892{
893 va_list ap;
894 int r;
895
896 va_start(ap, fmt);
897 r = vkdb_printf(KDB_MSGSRC_INTERNAL, fmt, ap);
898 va_end(ap);
899
900 return r;
901}
902EXPORT_SYMBOL_GPL(kdb_printf);