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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, const 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(enum kdb_msgsrc src, 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 if (kdb_grepping_flag >= KDB_GREPPING_FLAG_SEARCH)
684 /*
685 * This was a interactive search (using '/' at more
686 * prompt) and it has completed. Clear the flag.
687 */
688 kdb_grepping_flag = 0;
689 /*
690 * at this point the string is a full line and
691 * should be printed, up to the null.
692 */
693 }
694kdb_printit:
695
696 /*
697 * Write to all consoles.
698 */
699 retlen = strlen(kdb_buffer);
700 cp = (char *) printk_skip_level(kdb_buffer);
701 if (!dbg_kdb_mode && kgdb_connected) {
702 gdbstub_msg_write(cp, retlen - (cp - kdb_buffer));
703 } else {
704 if (dbg_io_ops && !dbg_io_ops->is_console) {
705 len = retlen - (cp - kdb_buffer);
706 cp2 = cp;
707 while (len--) {
708 dbg_io_ops->write_char(*cp2);
709 cp2++;
710 }
711 }
712 while (c) {
713 c->write(c, cp, retlen - (cp - kdb_buffer));
714 touch_nmi_watchdog();
715 c = c->next;
716 }
717 }
718 if (logging) {
719 saved_loglevel = console_loglevel;
720 console_loglevel = CONSOLE_LOGLEVEL_SILENT;
721 if (printk_get_level(kdb_buffer) || src == KDB_MSGSRC_PRINTK)
722 printk("%s", kdb_buffer);
723 else
724 pr_info("%s", kdb_buffer);
725 }
726
727 if (KDB_STATE(PAGER)) {
728 /*
729 * Check printed string to decide how to bump the
730 * kdb_nextline to control when the more prompt should
731 * show up.
732 */
733 int got = 0;
734 len = retlen;
735 while (len--) {
736 if (kdb_buffer[len] == '\n') {
737 kdb_nextline++;
738 got = 0;
739 } else if (kdb_buffer[len] == '\r') {
740 got = 0;
741 } else {
742 got++;
743 }
744 }
745 kdb_nextline += got / (colcount + 1);
746 }
747
748 /* check for having reached the LINES number of printed lines */
749 if (kdb_nextline >= linecount) {
750 char buf1[16] = "";
751
752 /* Watch out for recursion here. Any routine that calls
753 * kdb_printf will come back through here. And kdb_read
754 * uses kdb_printf to echo on serial consoles ...
755 */
756 kdb_nextline = 1; /* In case of recursion */
757
758 /*
759 * Pause until cr.
760 */
761 moreprompt = kdbgetenv("MOREPROMPT");
762 if (moreprompt == NULL)
763 moreprompt = "more> ";
764
765 kdb_input_flush();
766 c = console_drivers;
767
768 if (dbg_io_ops && !dbg_io_ops->is_console) {
769 len = strlen(moreprompt);
770 cp = moreprompt;
771 while (len--) {
772 dbg_io_ops->write_char(*cp);
773 cp++;
774 }
775 }
776 while (c) {
777 c->write(c, moreprompt, strlen(moreprompt));
778 touch_nmi_watchdog();
779 c = c->next;
780 }
781
782 if (logging)
783 printk("%s", moreprompt);
784
785 kdb_read(buf1, 2); /* '2' indicates to return
786 * immediately after getting one key. */
787 kdb_nextline = 1; /* Really set output line 1 */
788
789 /* empty and reset the buffer: */
790 kdb_buffer[0] = '\0';
791 next_avail = kdb_buffer;
792 size_avail = sizeof(kdb_buffer);
793 if ((buf1[0] == 'q') || (buf1[0] == 'Q')) {
794 /* user hit q or Q */
795 KDB_FLAG_SET(CMD_INTERRUPT); /* command interrupted */
796 KDB_STATE_CLEAR(PAGER);
797 /* end of command output; back to normal mode */
798 kdb_grepping_flag = 0;
799 kdb_printf("\n");
800 } else if (buf1[0] == ' ') {
801 kdb_printf("\r");
802 suspend_grep = 1; /* for this recursion */
803 } else if (buf1[0] == '\n') {
804 kdb_nextline = linecount - 1;
805 kdb_printf("\r");
806 suspend_grep = 1; /* for this recursion */
807 } else if (buf1[0] == '/' && !kdb_grepping_flag) {
808 kdb_printf("\r");
809 kdb_getstr(kdb_grep_string, KDB_GREP_STRLEN,
810 kdbgetenv("SEARCHPROMPT") ?: "search> ");
811 *strchrnul(kdb_grep_string, '\n') = '\0';
812 kdb_grepping_flag += KDB_GREPPING_FLAG_SEARCH;
813 suspend_grep = 1; /* for this recursion */
814 } else if (buf1[0] && buf1[0] != '\n') {
815 /* user hit something other than enter */
816 suspend_grep = 1; /* for this recursion */
817 if (buf1[0] != '/')
818 kdb_printf(
819 "\nOnly 'q', 'Q' or '/' are processed at "
820 "more prompt, input ignored\n");
821 else
822 kdb_printf("\n'/' cannot be used during | "
823 "grep filtering, input ignored\n");
824 } else if (kdb_grepping_flag) {
825 /* user hit enter */
826 suspend_grep = 1; /* for this recursion */
827 kdb_printf("\n");
828 }
829 kdb_input_flush();
830 }
831
832 /*
833 * For grep searches, shift the printed string left.
834 * replaced_byte contains the character that was overwritten with
835 * the terminating null, and cphold points to the null.
836 * Then adjust the notion of available space in the buffer.
837 */
838 if (kdb_grepping_flag && !suspend_grep) {
839 *cphold = replaced_byte;
840 strcpy(kdb_buffer, cphold);
841 len = strlen(kdb_buffer);
842 next_avail = kdb_buffer + len;
843 size_avail = sizeof(kdb_buffer) - len;
844 }
845
846kdb_print_out:
847 suspend_grep = 0; /* end of what may have been a recursive call */
848 if (logging)
849 console_loglevel = saved_loglevel;
850 if (KDB_STATE(PRINTF_LOCK) && got_printf_lock) {
851 got_printf_lock = 0;
852 spin_unlock_irqrestore(&kdb_printf_lock, flags);
853 KDB_STATE_CLEAR(PRINTF_LOCK);
854 atomic_dec(&kdb_event);
855 } else {
856 __release(kdb_printf_lock);
857 }
858 kdb_trap_printk = saved_trap_printk;
859 preempt_enable();
860 return retlen;
861}
862
863int kdb_printf(const char *fmt, ...)
864{
865 va_list ap;
866 int r;
867
868 va_start(ap, fmt);
869 r = vkdb_printf(KDB_MSGSRC_INTERNAL, fmt, ap);
870 va_end(ap);
871
872 return r;
873}
874EXPORT_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
52/**
53 * kdb_handle_escape() - validity check on an accumulated escape sequence.
54 * @buf: Accumulated escape characters to be examined. Note that buf
55 * is not a string, it is an array of characters and need not be
56 * nil terminated.
57 * @sz: Number of accumulated escape characters.
58 *
59 * Return: -1 if the escape sequence is unwanted, 0 if it is incomplete,
60 * otherwise it returns a mapped key value to pass to the upper layers.
61 */
62static int kdb_handle_escape(char *buf, size_t sz)
63{
64 char *lastkey = buf + sz - 1;
65
66 switch (sz) {
67 case 1:
68 if (*lastkey == '\e')
69 return 0;
70 break;
71
72 case 2: /* \e<something> */
73 if (*lastkey == '[')
74 return 0;
75 break;
76
77 case 3:
78 switch (*lastkey) {
79 case 'A': /* \e[A, up arrow */
80 return 16;
81 case 'B': /* \e[B, down arrow */
82 return 14;
83 case 'C': /* \e[C, right arrow */
84 return 6;
85 case 'D': /* \e[D, left arrow */
86 return 2;
87 case '1': /* \e[<1,3,4>], may be home, del, end */
88 case '3':
89 case '4':
90 return 0;
91 }
92 break;
93
94 case 4:
95 if (*lastkey == '~') {
96 switch (buf[2]) {
97 case '1': /* \e[1~, home */
98 return 1;
99 case '3': /* \e[3~, del */
100 return 4;
101 case '4': /* \e[4~, end */
102 return 5;
103 }
104 }
105 break;
106 }
107
108 return -1;
109}
110
111/**
112 * kdb_getchar() - Read a single character from a kdb console (or consoles).
113 *
114 * Other than polling the various consoles that are currently enabled,
115 * most of the work done in this function is dealing with escape sequences.
116 *
117 * An escape key could be the start of a vt100 control sequence such as \e[D
118 * (left arrow) or it could be a character in its own right. The standard
119 * method for detecting the difference is to wait for 2 seconds to see if there
120 * are any other characters. kdb is complicated by the lack of a timer service
121 * (interrupts are off), by multiple input sources. Escape sequence processing
122 * has to be done as states in the polling loop.
123 *
124 * Return: The key pressed or a control code derived from an escape sequence.
125 */
126char kdb_getchar(void)
127{
128#define ESCAPE_UDELAY 1000
129#define ESCAPE_DELAY (2*1000000/ESCAPE_UDELAY) /* 2 seconds worth of udelays */
130 char buf[4]; /* longest vt100 escape sequence is 4 bytes */
131 char *pbuf = buf;
132 int escape_delay = 0;
133 get_char_func *f, *f_prev = NULL;
134 int key;
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 * When the first character is received (or we get a change
155 * input source) we set ourselves up to handle an escape
156 * sequences (just in case).
157 */
158 if (f_prev != f) {
159 f_prev = f;
160 pbuf = buf;
161 escape_delay = ESCAPE_DELAY;
162 }
163
164 *pbuf++ = key;
165 key = kdb_handle_escape(buf, pbuf - buf);
166 if (key < 0) /* no escape sequence; return best character */
167 return buf[pbuf - buf == 2 ? 1 : 0];
168 if (key > 0)
169 return key;
170 }
171
172 unreachable();
173}
174
175/*
176 * kdb_read
177 *
178 * This function reads a string of characters, terminated by
179 * a newline, or by reaching the end of the supplied buffer,
180 * from the current kernel debugger console device.
181 * Parameters:
182 * buffer - Address of character buffer to receive input characters.
183 * bufsize - size, in bytes, of the character buffer
184 * Returns:
185 * Returns a pointer to the buffer containing the received
186 * character string. This string will be terminated by a
187 * newline character.
188 * Locking:
189 * No locks are required to be held upon entry to this
190 * function. It is not reentrant - it relies on the fact
191 * that while kdb is running on only one "master debug" cpu.
192 * Remarks:
193 * The buffer size must be >= 2.
194 */
195
196static char *kdb_read(char *buffer, size_t bufsize)
197{
198 char *cp = buffer;
199 char *bufend = buffer+bufsize-2; /* Reserve space for newline
200 * and null byte */
201 char *lastchar;
202 char *p_tmp;
203 char tmp;
204 static char tmpbuffer[CMD_BUFLEN];
205 int len = strlen(buffer);
206 int len_tmp;
207 int tab = 0;
208 int count;
209 int i;
210 int diag, dtab_count;
211 int key, buf_size, ret;
212
213
214 diag = kdbgetintenv("DTABCOUNT", &dtab_count);
215 if (diag)
216 dtab_count = 30;
217
218 if (len > 0) {
219 cp += len;
220 if (*(buffer+len-1) == '\n')
221 cp--;
222 }
223
224 lastchar = cp;
225 *cp = '\0';
226 kdb_printf("%s", buffer);
227poll_again:
228 key = kdb_getchar();
229 if (key != 9)
230 tab = 0;
231 switch (key) {
232 case 8: /* backspace */
233 if (cp > buffer) {
234 if (cp < lastchar) {
235 memcpy(tmpbuffer, cp, lastchar - cp);
236 memcpy(cp-1, tmpbuffer, lastchar - cp);
237 }
238 *(--lastchar) = '\0';
239 --cp;
240 kdb_printf("\b%s \r", cp);
241 tmp = *cp;
242 *cp = '\0';
243 kdb_printf(kdb_prompt_str);
244 kdb_printf("%s", buffer);
245 *cp = tmp;
246 }
247 break;
248 case 13: /* enter */
249 *lastchar++ = '\n';
250 *lastchar++ = '\0';
251 if (!KDB_STATE(KGDB_TRANS)) {
252 KDB_STATE_SET(KGDB_TRANS);
253 kdb_printf("%s", buffer);
254 }
255 kdb_printf("\n");
256 return buffer;
257 case 4: /* Del */
258 if (cp < lastchar) {
259 memcpy(tmpbuffer, cp+1, lastchar - cp - 1);
260 memcpy(cp, tmpbuffer, lastchar - cp - 1);
261 *(--lastchar) = '\0';
262 kdb_printf("%s \r", cp);
263 tmp = *cp;
264 *cp = '\0';
265 kdb_printf(kdb_prompt_str);
266 kdb_printf("%s", buffer);
267 *cp = tmp;
268 }
269 break;
270 case 1: /* Home */
271 if (cp > buffer) {
272 kdb_printf("\r");
273 kdb_printf(kdb_prompt_str);
274 cp = buffer;
275 }
276 break;
277 case 5: /* End */
278 if (cp < lastchar) {
279 kdb_printf("%s", cp);
280 cp = lastchar;
281 }
282 break;
283 case 2: /* Left */
284 if (cp > buffer) {
285 kdb_printf("\b");
286 --cp;
287 }
288 break;
289 case 14: /* Down */
290 memset(tmpbuffer, ' ',
291 strlen(kdb_prompt_str) + (lastchar-buffer));
292 *(tmpbuffer+strlen(kdb_prompt_str) +
293 (lastchar-buffer)) = '\0';
294 kdb_printf("\r%s\r", tmpbuffer);
295 *lastchar = (char)key;
296 *(lastchar+1) = '\0';
297 return lastchar;
298 case 6: /* Right */
299 if (cp < lastchar) {
300 kdb_printf("%c", *cp);
301 ++cp;
302 }
303 break;
304 case 16: /* Up */
305 memset(tmpbuffer, ' ',
306 strlen(kdb_prompt_str) + (lastchar-buffer));
307 *(tmpbuffer+strlen(kdb_prompt_str) +
308 (lastchar-buffer)) = '\0';
309 kdb_printf("\r%s\r", tmpbuffer);
310 *lastchar = (char)key;
311 *(lastchar+1) = '\0';
312 return lastchar;
313 case 9: /* Tab */
314 if (tab < 2)
315 ++tab;
316 p_tmp = buffer;
317 while (*p_tmp == ' ')
318 p_tmp++;
319 if (p_tmp > cp)
320 break;
321 memcpy(tmpbuffer, p_tmp, cp-p_tmp);
322 *(tmpbuffer + (cp-p_tmp)) = '\0';
323 p_tmp = strrchr(tmpbuffer, ' ');
324 if (p_tmp)
325 ++p_tmp;
326 else
327 p_tmp = tmpbuffer;
328 len = strlen(p_tmp);
329 buf_size = sizeof(tmpbuffer) - (p_tmp - tmpbuffer);
330 count = kallsyms_symbol_complete(p_tmp, buf_size);
331 if (tab == 2 && count > 0) {
332 kdb_printf("\n%d symbols are found.", count);
333 if (count > dtab_count) {
334 count = dtab_count;
335 kdb_printf(" But only first %d symbols will"
336 " be printed.\nYou can change the"
337 " environment variable DTABCOUNT.",
338 count);
339 }
340 kdb_printf("\n");
341 for (i = 0; i < count; i++) {
342 ret = kallsyms_symbol_next(p_tmp, i, buf_size);
343 if (WARN_ON(!ret))
344 break;
345 if (ret != -E2BIG)
346 kdb_printf("%s ", p_tmp);
347 else
348 kdb_printf("%s... ", p_tmp);
349 *(p_tmp + len) = '\0';
350 }
351 if (i >= dtab_count)
352 kdb_printf("...");
353 kdb_printf("\n");
354 kdb_printf(kdb_prompt_str);
355 kdb_printf("%s", buffer);
356 } else if (tab != 2 && count > 0) {
357 len_tmp = strlen(p_tmp);
358 strncpy(p_tmp+len_tmp, cp, lastchar-cp+1);
359 len_tmp = strlen(p_tmp);
360 strncpy(cp, p_tmp+len, len_tmp-len + 1);
361 len = len_tmp - len;
362 kdb_printf("%s", cp);
363 cp += len;
364 lastchar += len;
365 }
366 kdb_nextline = 1; /* reset output line number */
367 break;
368 default:
369 if (key >= 32 && lastchar < bufend) {
370 if (cp < lastchar) {
371 memcpy(tmpbuffer, cp, lastchar - cp);
372 memcpy(cp+1, tmpbuffer, lastchar - cp);
373 *++lastchar = '\0';
374 *cp = key;
375 kdb_printf("%s\r", cp);
376 ++cp;
377 tmp = *cp;
378 *cp = '\0';
379 kdb_printf(kdb_prompt_str);
380 kdb_printf("%s", buffer);
381 *cp = tmp;
382 } else {
383 *++lastchar = '\0';
384 *cp++ = key;
385 /* The kgdb transition check will hide
386 * printed characters if we think that
387 * kgdb is connecting, until the check
388 * fails */
389 if (!KDB_STATE(KGDB_TRANS)) {
390 if (kgdb_transition_check(buffer))
391 return buffer;
392 } else {
393 kdb_printf("%c", key);
394 }
395 }
396 /* Special escape to kgdb */
397 if (lastchar - buffer >= 5 &&
398 strcmp(lastchar - 5, "$?#3f") == 0) {
399 kdb_gdb_state_pass(lastchar - 5);
400 strcpy(buffer, "kgdb");
401 KDB_STATE_SET(DOING_KGDB);
402 return buffer;
403 }
404 if (lastchar - buffer >= 11 &&
405 strcmp(lastchar - 11, "$qSupported") == 0) {
406 kdb_gdb_state_pass(lastchar - 11);
407 strcpy(buffer, "kgdb");
408 KDB_STATE_SET(DOING_KGDB);
409 return buffer;
410 }
411 }
412 break;
413 }
414 goto poll_again;
415}
416
417/*
418 * kdb_getstr
419 *
420 * Print the prompt string and read a command from the
421 * input device.
422 *
423 * Parameters:
424 * buffer Address of buffer to receive command
425 * bufsize Size of buffer in bytes
426 * prompt Pointer to string to use as prompt string
427 * Returns:
428 * Pointer to command buffer.
429 * Locking:
430 * None.
431 * Remarks:
432 * For SMP kernels, the processor number will be
433 * substituted for %d, %x or %o in the prompt.
434 */
435
436char *kdb_getstr(char *buffer, size_t bufsize, const char *prompt)
437{
438 if (prompt && kdb_prompt_str != prompt)
439 strscpy(kdb_prompt_str, prompt, CMD_BUFLEN);
440 kdb_printf(kdb_prompt_str);
441 kdb_nextline = 1; /* Prompt and input resets line number */
442 return kdb_read(buffer, bufsize);
443}
444
445/*
446 * kdb_input_flush
447 *
448 * Get rid of any buffered console input.
449 *
450 * Parameters:
451 * none
452 * Returns:
453 * nothing
454 * Locking:
455 * none
456 * Remarks:
457 * Call this function whenever you want to flush input. If there is any
458 * outstanding input, it ignores all characters until there has been no
459 * data for approximately 1ms.
460 */
461
462static void kdb_input_flush(void)
463{
464 get_char_func *f;
465 int res;
466 int flush_delay = 1;
467 while (flush_delay) {
468 flush_delay--;
469empty:
470 touch_nmi_watchdog();
471 for (f = &kdb_poll_funcs[0]; *f; ++f) {
472 res = (*f)();
473 if (res != -1) {
474 flush_delay = 1;
475 goto empty;
476 }
477 }
478 if (flush_delay)
479 mdelay(1);
480 }
481}
482
483/*
484 * kdb_printf
485 *
486 * Print a string to the output device(s).
487 *
488 * Parameters:
489 * printf-like format and optional args.
490 * Returns:
491 * 0
492 * Locking:
493 * None.
494 * Remarks:
495 * use 'kdbcons->write()' to avoid polluting 'log_buf' with
496 * kdb output.
497 *
498 * If the user is doing a cmd args | grep srch
499 * then kdb_grepping_flag is set.
500 * In that case we need to accumulate full lines (ending in \n) before
501 * searching for the pattern.
502 */
503
504static char kdb_buffer[256]; /* A bit too big to go on stack */
505static char *next_avail = kdb_buffer;
506static int size_avail;
507static int suspend_grep;
508
509/*
510 * search arg1 to see if it contains arg2
511 * (kdmain.c provides flags for ^pat and pat$)
512 *
513 * return 1 for found, 0 for not found
514 */
515static int kdb_search_string(char *searched, char *searchfor)
516{
517 char firstchar, *cp;
518 int len1, len2;
519
520 /* not counting the newline at the end of "searched" */
521 len1 = strlen(searched)-1;
522 len2 = strlen(searchfor);
523 if (len1 < len2)
524 return 0;
525 if (kdb_grep_leading && kdb_grep_trailing && len1 != len2)
526 return 0;
527 if (kdb_grep_leading) {
528 if (!strncmp(searched, searchfor, len2))
529 return 1;
530 } else if (kdb_grep_trailing) {
531 if (!strncmp(searched+len1-len2, searchfor, len2))
532 return 1;
533 } else {
534 firstchar = *searchfor;
535 cp = searched;
536 while ((cp = strchr(cp, firstchar))) {
537 if (!strncmp(cp, searchfor, len2))
538 return 1;
539 cp++;
540 }
541 }
542 return 0;
543}
544
545static void kdb_msg_write(const char *msg, int msg_len)
546{
547 struct console *c;
548
549 if (msg_len == 0)
550 return;
551
552 if (dbg_io_ops) {
553 const char *cp = msg;
554 int len = msg_len;
555
556 while (len--) {
557 dbg_io_ops->write_char(*cp);
558 cp++;
559 }
560 }
561
562 for_each_console(c) {
563 if (!(c->flags & CON_ENABLED))
564 continue;
565 if (c == dbg_io_ops->cons)
566 continue;
567 /*
568 * Set oops_in_progress to encourage the console drivers to
569 * disregard their internal spin locks: in the current calling
570 * context the risk of deadlock is a bigger problem than risks
571 * due to re-entering the console driver. We operate directly on
572 * oops_in_progress rather than using bust_spinlocks() because
573 * the calls bust_spinlocks() makes on exit are not appropriate
574 * for this calling context.
575 */
576 ++oops_in_progress;
577 c->write(c, msg, msg_len);
578 --oops_in_progress;
579 touch_nmi_watchdog();
580 }
581}
582
583int vkdb_printf(enum kdb_msgsrc src, const char *fmt, va_list ap)
584{
585 int diag;
586 int linecount;
587 int colcount;
588 int logging, saved_loglevel = 0;
589 int retlen = 0;
590 int fnd, len;
591 int this_cpu, old_cpu;
592 char *cp, *cp2, *cphold = NULL, replaced_byte = ' ';
593 char *moreprompt = "more> ";
594 unsigned long flags;
595
596 /* Serialize kdb_printf if multiple cpus try to write at once.
597 * But if any cpu goes recursive in kdb, just print the output,
598 * even if it is interleaved with any other text.
599 */
600 local_irq_save(flags);
601 this_cpu = smp_processor_id();
602 for (;;) {
603 old_cpu = cmpxchg(&kdb_printf_cpu, -1, this_cpu);
604 if (old_cpu == -1 || old_cpu == this_cpu)
605 break;
606
607 cpu_relax();
608 }
609
610 diag = kdbgetintenv("LINES", &linecount);
611 if (diag || linecount <= 1)
612 linecount = 24;
613
614 diag = kdbgetintenv("COLUMNS", &colcount);
615 if (diag || colcount <= 1)
616 colcount = 80;
617
618 diag = kdbgetintenv("LOGGING", &logging);
619 if (diag)
620 logging = 0;
621
622 if (!kdb_grepping_flag || suspend_grep) {
623 /* normally, every vsnprintf starts a new buffer */
624 next_avail = kdb_buffer;
625 size_avail = sizeof(kdb_buffer);
626 }
627 vsnprintf(next_avail, size_avail, fmt, ap);
628
629 /*
630 * If kdb_parse() found that the command was cmd xxx | grep yyy
631 * then kdb_grepping_flag is set, and kdb_grep_string contains yyy
632 *
633 * Accumulate the print data up to a newline before searching it.
634 * (vsnprintf does null-terminate the string that it generates)
635 */
636
637 /* skip the search if prints are temporarily unconditional */
638 if (!suspend_grep && kdb_grepping_flag) {
639 cp = strchr(kdb_buffer, '\n');
640 if (!cp) {
641 /*
642 * Special cases that don't end with newlines
643 * but should be written without one:
644 * The "[nn]kdb> " prompt should
645 * appear at the front of the buffer.
646 *
647 * The "[nn]more " prompt should also be
648 * (MOREPROMPT -> moreprompt)
649 * written * but we print that ourselves,
650 * we set the suspend_grep flag to make
651 * it unconditional.
652 *
653 */
654 if (next_avail == kdb_buffer) {
655 /*
656 * these should occur after a newline,
657 * so they will be at the front of the
658 * buffer
659 */
660 cp2 = kdb_buffer;
661 len = strlen(kdb_prompt_str);
662 if (!strncmp(cp2, kdb_prompt_str, len)) {
663 /*
664 * We're about to start a new
665 * command, so we can go back
666 * to normal mode.
667 */
668 kdb_grepping_flag = 0;
669 goto kdb_printit;
670 }
671 }
672 /* no newline; don't search/write the buffer
673 until one is there */
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
680 /*
681 * The newline is present; print through it or discard
682 * it, depending on the results of the search.
683 */
684 cp++; /* to byte after the newline */
685 replaced_byte = *cp; /* remember what/where it was */
686 cphold = cp;
687 *cp = '\0'; /* end the string for our search */
688
689 /*
690 * We now have a newline at the end of the string
691 * Only continue with this output if it contains the
692 * search string.
693 */
694 fnd = kdb_search_string(kdb_buffer, kdb_grep_string);
695 if (!fnd) {
696 /*
697 * At this point the complete line at the start
698 * of kdb_buffer can be discarded, as it does
699 * not contain what the user is looking for.
700 * Shift the buffer left.
701 */
702 *cphold = replaced_byte;
703 strcpy(kdb_buffer, cphold);
704 len = strlen(kdb_buffer);
705 next_avail = kdb_buffer + len;
706 size_avail = sizeof(kdb_buffer) - len;
707 goto kdb_print_out;
708 }
709 if (kdb_grepping_flag >= KDB_GREPPING_FLAG_SEARCH)
710 /*
711 * This was a interactive search (using '/' at more
712 * prompt) and it has completed. Clear the flag.
713 */
714 kdb_grepping_flag = 0;
715 /*
716 * at this point the string is a full line and
717 * should be printed, up to the null.
718 */
719 }
720kdb_printit:
721
722 /*
723 * Write to all consoles.
724 */
725 retlen = strlen(kdb_buffer);
726 cp = (char *) printk_skip_headers(kdb_buffer);
727 if (!dbg_kdb_mode && kgdb_connected)
728 gdbstub_msg_write(cp, retlen - (cp - kdb_buffer));
729 else
730 kdb_msg_write(cp, retlen - (cp - kdb_buffer));
731
732 if (logging) {
733 saved_loglevel = console_loglevel;
734 console_loglevel = CONSOLE_LOGLEVEL_SILENT;
735 if (printk_get_level(kdb_buffer) || src == KDB_MSGSRC_PRINTK)
736 printk("%s", kdb_buffer);
737 else
738 pr_info("%s", kdb_buffer);
739 }
740
741 if (KDB_STATE(PAGER)) {
742 /*
743 * Check printed string to decide how to bump the
744 * kdb_nextline to control when the more prompt should
745 * show up.
746 */
747 int got = 0;
748 len = retlen;
749 while (len--) {
750 if (kdb_buffer[len] == '\n') {
751 kdb_nextline++;
752 got = 0;
753 } else if (kdb_buffer[len] == '\r') {
754 got = 0;
755 } else {
756 got++;
757 }
758 }
759 kdb_nextline += got / (colcount + 1);
760 }
761
762 /* check for having reached the LINES number of printed lines */
763 if (kdb_nextline >= linecount) {
764 char ch;
765
766 /* Watch out for recursion here. Any routine that calls
767 * kdb_printf will come back through here. And kdb_read
768 * uses kdb_printf to echo on serial consoles ...
769 */
770 kdb_nextline = 1; /* In case of recursion */
771
772 /*
773 * Pause until cr.
774 */
775 moreprompt = kdbgetenv("MOREPROMPT");
776 if (moreprompt == NULL)
777 moreprompt = "more> ";
778
779 kdb_input_flush();
780 kdb_msg_write(moreprompt, strlen(moreprompt));
781
782 if (logging)
783 printk("%s", moreprompt);
784
785 ch = kdb_getchar();
786 kdb_nextline = 1; /* Really set output line 1 */
787
788 /* empty and reset the buffer: */
789 kdb_buffer[0] = '\0';
790 next_avail = kdb_buffer;
791 size_avail = sizeof(kdb_buffer);
792 if ((ch == 'q') || (ch == 'Q')) {
793 /* user hit q or Q */
794 KDB_FLAG_SET(CMD_INTERRUPT); /* command interrupted */
795 KDB_STATE_CLEAR(PAGER);
796 /* end of command output; back to normal mode */
797 kdb_grepping_flag = 0;
798 kdb_printf("\n");
799 } else if (ch == ' ') {
800 kdb_printf("\r");
801 suspend_grep = 1; /* for this recursion */
802 } else if (ch == '\n' || ch == '\r') {
803 kdb_nextline = linecount - 1;
804 kdb_printf("\r");
805 suspend_grep = 1; /* for this recursion */
806 } else if (ch == '/' && !kdb_grepping_flag) {
807 kdb_printf("\r");
808 kdb_getstr(kdb_grep_string, KDB_GREP_STRLEN,
809 kdbgetenv("SEARCHPROMPT") ?: "search> ");
810 *strchrnul(kdb_grep_string, '\n') = '\0';
811 kdb_grepping_flag += KDB_GREPPING_FLAG_SEARCH;
812 suspend_grep = 1; /* for this recursion */
813 } else if (ch) {
814 /* user hit something unexpected */
815 suspend_grep = 1; /* for this recursion */
816 if (ch != '/')
817 kdb_printf(
818 "\nOnly 'q', 'Q' or '/' are processed at "
819 "more prompt, input ignored\n");
820 else
821 kdb_printf("\n'/' cannot be used during | "
822 "grep filtering, input ignored\n");
823 } else if (kdb_grepping_flag) {
824 /* user hit enter */
825 suspend_grep = 1; /* for this recursion */
826 kdb_printf("\n");
827 }
828 kdb_input_flush();
829 }
830
831 /*
832 * For grep searches, shift the printed string left.
833 * replaced_byte contains the character that was overwritten with
834 * the terminating null, and cphold points to the null.
835 * Then adjust the notion of available space in the buffer.
836 */
837 if (kdb_grepping_flag && !suspend_grep) {
838 *cphold = replaced_byte;
839 strcpy(kdb_buffer, cphold);
840 len = strlen(kdb_buffer);
841 next_avail = kdb_buffer + len;
842 size_avail = sizeof(kdb_buffer) - len;
843 }
844
845kdb_print_out:
846 suspend_grep = 0; /* end of what may have been a recursive call */
847 if (logging)
848 console_loglevel = saved_loglevel;
849 /* kdb_printf_cpu locked the code above. */
850 smp_store_release(&kdb_printf_cpu, old_cpu);
851 local_irq_restore(flags);
852 return retlen;
853}
854
855int kdb_printf(const char *fmt, ...)
856{
857 va_list ap;
858 int r;
859
860 va_start(ap, fmt);
861 r = vkdb_printf(KDB_MSGSRC_INTERNAL, fmt, ap);
862 va_end(ap);
863
864 return r;
865}
866EXPORT_SYMBOL_GPL(kdb_printf);