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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;
33int kdb_printf_cpu = -1;
34
35static int kgdb_transition_check(char *buffer)
36{
37 if (buffer[0] != '+' && buffer[0] != '$') {
38 KDB_STATE_SET(KGDB_TRANS);
39 kdb_printf("%s", buffer);
40 } else {
41 int slen = strlen(buffer);
42 if (slen > 3 && buffer[slen - 3] == '#') {
43 kdb_gdb_state_pass(buffer);
44 strcpy(buffer, "kgdb");
45 KDB_STATE_SET(DOING_KGDB);
46 return 1;
47 }
48 }
49 return 0;
50}
51
52static int kdb_read_get_key(char *buffer, size_t bufsize)
53{
54#define ESCAPE_UDELAY 1000
55#define ESCAPE_DELAY (2*1000000/ESCAPE_UDELAY) /* 2 seconds worth of udelays */
56 char escape_data[5]; /* longest vt100 escape sequence is 4 bytes */
57 char *ped = escape_data;
58 int escape_delay = 0;
59 get_char_func *f, *f_escape = NULL;
60 int key;
61
62 for (f = &kdb_poll_funcs[0]; ; ++f) {
63 if (*f == NULL) {
64 /* Reset NMI watchdog once per poll loop */
65 touch_nmi_watchdog();
66 f = &kdb_poll_funcs[0];
67 }
68 if (escape_delay == 2) {
69 *ped = '\0';
70 ped = escape_data;
71 --escape_delay;
72 }
73 if (escape_delay == 1) {
74 key = *ped++;
75 if (!*ped)
76 --escape_delay;
77 break;
78 }
79 key = (*f)();
80 if (key == -1) {
81 if (escape_delay) {
82 udelay(ESCAPE_UDELAY);
83 --escape_delay;
84 }
85 continue;
86 }
87 if (bufsize <= 2) {
88 if (key == '\r')
89 key = '\n';
90 *buffer++ = key;
91 *buffer = '\0';
92 return -1;
93 }
94 if (escape_delay == 0 && key == '\e') {
95 escape_delay = ESCAPE_DELAY;
96 ped = escape_data;
97 f_escape = f;
98 }
99 if (escape_delay) {
100 *ped++ = key;
101 if (f_escape != f) {
102 escape_delay = 2;
103 continue;
104 }
105 if (ped - escape_data == 1) {
106 /* \e */
107 continue;
108 } else if (ped - escape_data == 2) {
109 /* \e<something> */
110 if (key != '[')
111 escape_delay = 2;
112 continue;
113 } else if (ped - escape_data == 3) {
114 /* \e[<something> */
115 int mapkey = 0;
116 switch (key) {
117 case 'A': /* \e[A, up arrow */
118 mapkey = 16;
119 break;
120 case 'B': /* \e[B, down arrow */
121 mapkey = 14;
122 break;
123 case 'C': /* \e[C, right arrow */
124 mapkey = 6;
125 break;
126 case 'D': /* \e[D, left arrow */
127 mapkey = 2;
128 break;
129 case '1': /* dropthrough */
130 case '3': /* dropthrough */
131 /* \e[<1,3,4>], may be home, del, end */
132 case '4':
133 mapkey = -1;
134 break;
135 }
136 if (mapkey != -1) {
137 if (mapkey > 0) {
138 escape_data[0] = mapkey;
139 escape_data[1] = '\0';
140 }
141 escape_delay = 2;
142 }
143 continue;
144 } else if (ped - escape_data == 4) {
145 /* \e[<1,3,4><something> */
146 int mapkey = 0;
147 if (key == '~') {
148 switch (escape_data[2]) {
149 case '1': /* \e[1~, home */
150 mapkey = 1;
151 break;
152 case '3': /* \e[3~, del */
153 mapkey = 4;
154 break;
155 case '4': /* \e[4~, end */
156 mapkey = 5;
157 break;
158 }
159 }
160 if (mapkey > 0) {
161 escape_data[0] = mapkey;
162 escape_data[1] = '\0';
163 }
164 escape_delay = 2;
165 continue;
166 }
167 }
168 break; /* A key to process */
169 }
170 return key;
171}
172
173/*
174 * kdb_read
175 *
176 * This function reads a string of characters, terminated by
177 * a newline, or by reaching the end of the supplied buffer,
178 * from the current kernel debugger console device.
179 * Parameters:
180 * buffer - Address of character buffer to receive input characters.
181 * bufsize - size, in bytes, of the character buffer
182 * Returns:
183 * Returns a pointer to the buffer containing the received
184 * character string. This string will be terminated by a
185 * newline character.
186 * Locking:
187 * No locks are required to be held upon entry to this
188 * function. It is not reentrant - it relies on the fact
189 * that while kdb is running on only one "master debug" cpu.
190 * Remarks:
191 *
192 * The buffer size must be >= 2. A buffer size of 2 means that the caller only
193 * wants a single key.
194 *
195 * An escape key could be the start of a vt100 control sequence such as \e[D
196 * (left arrow) or it could be a character in its own right. The standard
197 * method for detecting the difference is to wait for 2 seconds to see if there
198 * are any other characters. kdb is complicated by the lack of a timer service
199 * (interrupts are off), by multiple input sources and by the need to sometimes
200 * return after just one key. Escape sequence processing has to be done as
201 * states in the polling loop.
202 */
203
204static char *kdb_read(char *buffer, size_t bufsize)
205{
206 char *cp = buffer;
207 char *bufend = buffer+bufsize-2; /* Reserve space for newline
208 * and null byte */
209 char *lastchar;
210 char *p_tmp;
211 char tmp;
212 static char tmpbuffer[CMD_BUFLEN];
213 int len = strlen(buffer);
214 int len_tmp;
215 int tab = 0;
216 int count;
217 int i;
218 int diag, dtab_count;
219 int key, buf_size, ret;
220
221
222 diag = kdbgetintenv("DTABCOUNT", &dtab_count);
223 if (diag)
224 dtab_count = 30;
225
226 if (len > 0) {
227 cp += len;
228 if (*(buffer+len-1) == '\n')
229 cp--;
230 }
231
232 lastchar = cp;
233 *cp = '\0';
234 kdb_printf("%s", buffer);
235poll_again:
236 key = kdb_read_get_key(buffer, bufsize);
237 if (key == -1)
238 return buffer;
239 if (key != 9)
240 tab = 0;
241 switch (key) {
242 case 8: /* backspace */
243 if (cp > buffer) {
244 if (cp < lastchar) {
245 memcpy(tmpbuffer, cp, lastchar - cp);
246 memcpy(cp-1, tmpbuffer, lastchar - cp);
247 }
248 *(--lastchar) = '\0';
249 --cp;
250 kdb_printf("\b%s \r", cp);
251 tmp = *cp;
252 *cp = '\0';
253 kdb_printf(kdb_prompt_str);
254 kdb_printf("%s", buffer);
255 *cp = tmp;
256 }
257 break;
258 case 13: /* enter */
259 *lastchar++ = '\n';
260 *lastchar++ = '\0';
261 if (!KDB_STATE(KGDB_TRANS)) {
262 KDB_STATE_SET(KGDB_TRANS);
263 kdb_printf("%s", buffer);
264 }
265 kdb_printf("\n");
266 return buffer;
267 case 4: /* Del */
268 if (cp < lastchar) {
269 memcpy(tmpbuffer, cp+1, lastchar - cp - 1);
270 memcpy(cp, tmpbuffer, lastchar - cp - 1);
271 *(--lastchar) = '\0';
272 kdb_printf("%s \r", cp);
273 tmp = *cp;
274 *cp = '\0';
275 kdb_printf(kdb_prompt_str);
276 kdb_printf("%s", buffer);
277 *cp = tmp;
278 }
279 break;
280 case 1: /* Home */
281 if (cp > buffer) {
282 kdb_printf("\r");
283 kdb_printf(kdb_prompt_str);
284 cp = buffer;
285 }
286 break;
287 case 5: /* End */
288 if (cp < lastchar) {
289 kdb_printf("%s", cp);
290 cp = lastchar;
291 }
292 break;
293 case 2: /* Left */
294 if (cp > buffer) {
295 kdb_printf("\b");
296 --cp;
297 }
298 break;
299 case 14: /* Down */
300 memset(tmpbuffer, ' ',
301 strlen(kdb_prompt_str) + (lastchar-buffer));
302 *(tmpbuffer+strlen(kdb_prompt_str) +
303 (lastchar-buffer)) = '\0';
304 kdb_printf("\r%s\r", tmpbuffer);
305 *lastchar = (char)key;
306 *(lastchar+1) = '\0';
307 return lastchar;
308 case 6: /* Right */
309 if (cp < lastchar) {
310 kdb_printf("%c", *cp);
311 ++cp;
312 }
313 break;
314 case 16: /* Up */
315 memset(tmpbuffer, ' ',
316 strlen(kdb_prompt_str) + (lastchar-buffer));
317 *(tmpbuffer+strlen(kdb_prompt_str) +
318 (lastchar-buffer)) = '\0';
319 kdb_printf("\r%s\r", tmpbuffer);
320 *lastchar = (char)key;
321 *(lastchar+1) = '\0';
322 return lastchar;
323 case 9: /* Tab */
324 if (tab < 2)
325 ++tab;
326 p_tmp = buffer;
327 while (*p_tmp == ' ')
328 p_tmp++;
329 if (p_tmp > cp)
330 break;
331 memcpy(tmpbuffer, p_tmp, cp-p_tmp);
332 *(tmpbuffer + (cp-p_tmp)) = '\0';
333 p_tmp = strrchr(tmpbuffer, ' ');
334 if (p_tmp)
335 ++p_tmp;
336 else
337 p_tmp = tmpbuffer;
338 len = strlen(p_tmp);
339 buf_size = sizeof(tmpbuffer) - (p_tmp - tmpbuffer);
340 count = kallsyms_symbol_complete(p_tmp, buf_size);
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 ret = kallsyms_symbol_next(p_tmp, i, buf_size);
353 if (WARN_ON(!ret))
354 break;
355 if (ret != -E2BIG)
356 kdb_printf("%s ", p_tmp);
357 else
358 kdb_printf("%s... ", p_tmp);
359 *(p_tmp + len) = '\0';
360 }
361 if (i >= dtab_count)
362 kdb_printf("...");
363 kdb_printf("\n");
364 kdb_printf(kdb_prompt_str);
365 kdb_printf("%s", buffer);
366 } else if (tab != 2 && count > 0) {
367 len_tmp = strlen(p_tmp);
368 strncpy(p_tmp+len_tmp, cp, lastchar-cp+1);
369 len_tmp = strlen(p_tmp);
370 strncpy(cp, p_tmp+len, len_tmp-len + 1);
371 len = len_tmp - len;
372 kdb_printf("%s", cp);
373 cp += len;
374 lastchar += len;
375 }
376 kdb_nextline = 1; /* reset output line number */
377 break;
378 default:
379 if (key >= 32 && lastchar < bufend) {
380 if (cp < lastchar) {
381 memcpy(tmpbuffer, cp, lastchar - cp);
382 memcpy(cp+1, tmpbuffer, lastchar - cp);
383 *++lastchar = '\0';
384 *cp = key;
385 kdb_printf("%s\r", cp);
386 ++cp;
387 tmp = *cp;
388 *cp = '\0';
389 kdb_printf(kdb_prompt_str);
390 kdb_printf("%s", buffer);
391 *cp = tmp;
392 } else {
393 *++lastchar = '\0';
394 *cp++ = key;
395 /* The kgdb transition check will hide
396 * printed characters if we think that
397 * kgdb is connecting, until the check
398 * fails */
399 if (!KDB_STATE(KGDB_TRANS)) {
400 if (kgdb_transition_check(buffer))
401 return buffer;
402 } else {
403 kdb_printf("%c", key);
404 }
405 }
406 /* Special escape to kgdb */
407 if (lastchar - buffer >= 5 &&
408 strcmp(lastchar - 5, "$?#3f") == 0) {
409 kdb_gdb_state_pass(lastchar - 5);
410 strcpy(buffer, "kgdb");
411 KDB_STATE_SET(DOING_KGDB);
412 return buffer;
413 }
414 if (lastchar - buffer >= 11 &&
415 strcmp(lastchar - 11, "$qSupported") == 0) {
416 kdb_gdb_state_pass(lastchar - 11);
417 strcpy(buffer, "kgdb");
418 KDB_STATE_SET(DOING_KGDB);
419 return buffer;
420 }
421 }
422 break;
423 }
424 goto poll_again;
425}
426
427/*
428 * kdb_getstr
429 *
430 * Print the prompt string and read a command from the
431 * input device.
432 *
433 * Parameters:
434 * buffer Address of buffer to receive command
435 * bufsize Size of buffer in bytes
436 * prompt Pointer to string to use as prompt string
437 * Returns:
438 * Pointer to command buffer.
439 * Locking:
440 * None.
441 * Remarks:
442 * For SMP kernels, the processor number will be
443 * substituted for %d, %x or %o in the prompt.
444 */
445
446char *kdb_getstr(char *buffer, size_t bufsize, const char *prompt)
447{
448 if (prompt && kdb_prompt_str != prompt)
449 strscpy(kdb_prompt_str, prompt, CMD_BUFLEN);
450 kdb_printf(kdb_prompt_str);
451 kdb_nextline = 1; /* Prompt and input resets line number */
452 return kdb_read(buffer, bufsize);
453}
454
455/*
456 * kdb_input_flush
457 *
458 * Get rid of any buffered console input.
459 *
460 * Parameters:
461 * none
462 * Returns:
463 * nothing
464 * Locking:
465 * none
466 * Remarks:
467 * Call this function whenever you want to flush input. If there is any
468 * outstanding input, it ignores all characters until there has been no
469 * data for approximately 1ms.
470 */
471
472static void kdb_input_flush(void)
473{
474 get_char_func *f;
475 int res;
476 int flush_delay = 1;
477 while (flush_delay) {
478 flush_delay--;
479empty:
480 touch_nmi_watchdog();
481 for (f = &kdb_poll_funcs[0]; *f; ++f) {
482 res = (*f)();
483 if (res != -1) {
484 flush_delay = 1;
485 goto empty;
486 }
487 }
488 if (flush_delay)
489 mdelay(1);
490 }
491}
492
493/*
494 * kdb_printf
495 *
496 * Print a string to the output device(s).
497 *
498 * Parameters:
499 * printf-like format and optional args.
500 * Returns:
501 * 0
502 * Locking:
503 * None.
504 * Remarks:
505 * use 'kdbcons->write()' to avoid polluting 'log_buf' with
506 * kdb output.
507 *
508 * If the user is doing a cmd args | grep srch
509 * then kdb_grepping_flag is set.
510 * In that case we need to accumulate full lines (ending in \n) before
511 * searching for the pattern.
512 */
513
514static char kdb_buffer[256]; /* A bit too big to go on stack */
515static char *next_avail = kdb_buffer;
516static int size_avail;
517static int suspend_grep;
518
519/*
520 * search arg1 to see if it contains arg2
521 * (kdmain.c provides flags for ^pat and pat$)
522 *
523 * return 1 for found, 0 for not found
524 */
525static int kdb_search_string(char *searched, char *searchfor)
526{
527 char firstchar, *cp;
528 int len1, len2;
529
530 /* not counting the newline at the end of "searched" */
531 len1 = strlen(searched)-1;
532 len2 = strlen(searchfor);
533 if (len1 < len2)
534 return 0;
535 if (kdb_grep_leading && kdb_grep_trailing && len1 != len2)
536 return 0;
537 if (kdb_grep_leading) {
538 if (!strncmp(searched, searchfor, len2))
539 return 1;
540 } else if (kdb_grep_trailing) {
541 if (!strncmp(searched+len1-len2, searchfor, len2))
542 return 1;
543 } else {
544 firstchar = *searchfor;
545 cp = searched;
546 while ((cp = strchr(cp, firstchar))) {
547 if (!strncmp(cp, searchfor, len2))
548 return 1;
549 cp++;
550 }
551 }
552 return 0;
553}
554
555int vkdb_printf(enum kdb_msgsrc src, const char *fmt, va_list ap)
556{
557 int diag;
558 int linecount;
559 int colcount;
560 int logging, saved_loglevel = 0;
561 int retlen = 0;
562 int fnd, len;
563 int this_cpu, old_cpu;
564 char *cp, *cp2, *cphold = NULL, replaced_byte = ' ';
565 char *moreprompt = "more> ";
566 struct console *c = console_drivers;
567 unsigned long uninitialized_var(flags);
568
569 /* Serialize kdb_printf if multiple cpus try to write at once.
570 * But if any cpu goes recursive in kdb, just print the output,
571 * even if it is interleaved with any other text.
572 */
573 local_irq_save(flags);
574 this_cpu = smp_processor_id();
575 for (;;) {
576 old_cpu = cmpxchg(&kdb_printf_cpu, -1, this_cpu);
577 if (old_cpu == -1 || old_cpu == this_cpu)
578 break;
579
580 cpu_relax();
581 }
582
583 diag = kdbgetintenv("LINES", &linecount);
584 if (diag || linecount <= 1)
585 linecount = 24;
586
587 diag = kdbgetintenv("COLUMNS", &colcount);
588 if (diag || colcount <= 1)
589 colcount = 80;
590
591 diag = kdbgetintenv("LOGGING", &logging);
592 if (diag)
593 logging = 0;
594
595 if (!kdb_grepping_flag || suspend_grep) {
596 /* normally, every vsnprintf starts a new buffer */
597 next_avail = kdb_buffer;
598 size_avail = sizeof(kdb_buffer);
599 }
600 vsnprintf(next_avail, size_avail, fmt, ap);
601
602 /*
603 * If kdb_parse() found that the command was cmd xxx | grep yyy
604 * then kdb_grepping_flag is set, and kdb_grep_string contains yyy
605 *
606 * Accumulate the print data up to a newline before searching it.
607 * (vsnprintf does null-terminate the string that it generates)
608 */
609
610 /* skip the search if prints are temporarily unconditional */
611 if (!suspend_grep && kdb_grepping_flag) {
612 cp = strchr(kdb_buffer, '\n');
613 if (!cp) {
614 /*
615 * Special cases that don't end with newlines
616 * but should be written without one:
617 * The "[nn]kdb> " prompt should
618 * appear at the front of the buffer.
619 *
620 * The "[nn]more " prompt should also be
621 * (MOREPROMPT -> moreprompt)
622 * written * but we print that ourselves,
623 * we set the suspend_grep flag to make
624 * it unconditional.
625 *
626 */
627 if (next_avail == kdb_buffer) {
628 /*
629 * these should occur after a newline,
630 * so they will be at the front of the
631 * buffer
632 */
633 cp2 = kdb_buffer;
634 len = strlen(kdb_prompt_str);
635 if (!strncmp(cp2, kdb_prompt_str, len)) {
636 /*
637 * We're about to start a new
638 * command, so we can go back
639 * to normal mode.
640 */
641 kdb_grepping_flag = 0;
642 goto kdb_printit;
643 }
644 }
645 /* no newline; don't search/write the buffer
646 until one is there */
647 len = strlen(kdb_buffer);
648 next_avail = kdb_buffer + len;
649 size_avail = sizeof(kdb_buffer) - len;
650 goto kdb_print_out;
651 }
652
653 /*
654 * The newline is present; print through it or discard
655 * it, depending on the results of the search.
656 */
657 cp++; /* to byte after the newline */
658 replaced_byte = *cp; /* remember what/where it was */
659 cphold = cp;
660 *cp = '\0'; /* end the string for our search */
661
662 /*
663 * We now have a newline at the end of the string
664 * Only continue with this output if it contains the
665 * search string.
666 */
667 fnd = kdb_search_string(kdb_buffer, kdb_grep_string);
668 if (!fnd) {
669 /*
670 * At this point the complete line at the start
671 * of kdb_buffer can be discarded, as it does
672 * not contain what the user is looking for.
673 * Shift the buffer left.
674 */
675 *cphold = replaced_byte;
676 strcpy(kdb_buffer, cphold);
677 len = strlen(kdb_buffer);
678 next_avail = kdb_buffer + len;
679 size_avail = sizeof(kdb_buffer) - len;
680 goto kdb_print_out;
681 }
682 if (kdb_grepping_flag >= KDB_GREPPING_FLAG_SEARCH)
683 /*
684 * This was a interactive search (using '/' at more
685 * prompt) and it has completed. Clear the flag.
686 */
687 kdb_grepping_flag = 0;
688 /*
689 * at this point the string is a full line and
690 * should be printed, up to the null.
691 */
692 }
693kdb_printit:
694
695 /*
696 * Write to all consoles.
697 */
698 retlen = strlen(kdb_buffer);
699 cp = (char *) printk_skip_headers(kdb_buffer);
700 if (!dbg_kdb_mode && kgdb_connected) {
701 gdbstub_msg_write(cp, retlen - (cp - kdb_buffer));
702 } else {
703 if (dbg_io_ops && !dbg_io_ops->is_console) {
704 len = retlen - (cp - kdb_buffer);
705 cp2 = cp;
706 while (len--) {
707 dbg_io_ops->write_char(*cp2);
708 cp2++;
709 }
710 }
711 while (c) {
712 c->write(c, cp, retlen - (cp - kdb_buffer));
713 touch_nmi_watchdog();
714 c = c->next;
715 }
716 }
717 if (logging) {
718 saved_loglevel = console_loglevel;
719 console_loglevel = CONSOLE_LOGLEVEL_SILENT;
720 if (printk_get_level(kdb_buffer) || src == KDB_MSGSRC_PRINTK)
721 printk("%s", kdb_buffer);
722 else
723 pr_info("%s", kdb_buffer);
724 }
725
726 if (KDB_STATE(PAGER)) {
727 /*
728 * Check printed string to decide how to bump the
729 * kdb_nextline to control when the more prompt should
730 * show up.
731 */
732 int got = 0;
733 len = retlen;
734 while (len--) {
735 if (kdb_buffer[len] == '\n') {
736 kdb_nextline++;
737 got = 0;
738 } else if (kdb_buffer[len] == '\r') {
739 got = 0;
740 } else {
741 got++;
742 }
743 }
744 kdb_nextline += got / (colcount + 1);
745 }
746
747 /* check for having reached the LINES number of printed lines */
748 if (kdb_nextline >= linecount) {
749 char buf1[16] = "";
750
751 /* Watch out for recursion here. Any routine that calls
752 * kdb_printf will come back through here. And kdb_read
753 * uses kdb_printf to echo on serial consoles ...
754 */
755 kdb_nextline = 1; /* In case of recursion */
756
757 /*
758 * Pause until cr.
759 */
760 moreprompt = kdbgetenv("MOREPROMPT");
761 if (moreprompt == NULL)
762 moreprompt = "more> ";
763
764 kdb_input_flush();
765 c = console_drivers;
766
767 if (dbg_io_ops && !dbg_io_ops->is_console) {
768 len = strlen(moreprompt);
769 cp = moreprompt;
770 while (len--) {
771 dbg_io_ops->write_char(*cp);
772 cp++;
773 }
774 }
775 while (c) {
776 c->write(c, moreprompt, strlen(moreprompt));
777 touch_nmi_watchdog();
778 c = c->next;
779 }
780
781 if (logging)
782 printk("%s", moreprompt);
783
784 kdb_read(buf1, 2); /* '2' indicates to return
785 * immediately after getting one key. */
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 ((buf1[0] == 'q') || (buf1[0] == '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 (buf1[0] == ' ') {
800 kdb_printf("\r");
801 suspend_grep = 1; /* for this recursion */
802 } else if (buf1[0] == '\n') {
803 kdb_nextline = linecount - 1;
804 kdb_printf("\r");
805 suspend_grep = 1; /* for this recursion */
806 } else if (buf1[0] == '/' && !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 (buf1[0] && buf1[0] != '\n') {
814 /* user hit something other than enter */
815 suspend_grep = 1; /* for this recursion */
816 if (buf1[0] != '/')
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);
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);