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1/*
2 * Kernel Debugger Architecture Independent Console I/O handler
3 *
4 * This file is subject to the terms and conditions of the GNU General Public
5 * License. See the file "COPYING" in the main directory of this archive
6 * for more details.
7 *
8 * Copyright (c) 1999-2006 Silicon Graphics, Inc. All Rights Reserved.
9 * Copyright (c) 2009 Wind River Systems, Inc. All Rights Reserved.
10 */
11
12#include <linux/module.h>
13#include <linux/types.h>
14#include <linux/ctype.h>
15#include <linux/kernel.h>
16#include <linux/init.h>
17#include <linux/kdev_t.h>
18#include <linux/console.h>
19#include <linux/string.h>
20#include <linux/sched.h>
21#include <linux/smp.h>
22#include <linux/nmi.h>
23#include <linux/delay.h>
24#include <linux/kgdb.h>
25#include <linux/kdb.h>
26#include <linux/kallsyms.h>
27#include "kdb_private.h"
28
29#define CMD_BUFLEN 256
30char kdb_prompt_str[CMD_BUFLEN];
31
32int kdb_trap_printk;
33
34static int kgdb_transition_check(char *buffer)
35{
36 if (buffer[0] != '+' && buffer[0] != '$') {
37 KDB_STATE_SET(KGDB_TRANS);
38 kdb_printf("%s", buffer);
39 } else {
40 int slen = strlen(buffer);
41 if (slen > 3 && buffer[slen - 3] == '#') {
42 kdb_gdb_state_pass(buffer);
43 strcpy(buffer, "kgdb");
44 KDB_STATE_SET(DOING_KGDB);
45 return 1;
46 }
47 }
48 return 0;
49}
50
51static int kdb_read_get_key(char *buffer, size_t bufsize)
52{
53#define ESCAPE_UDELAY 1000
54#define ESCAPE_DELAY (2*1000000/ESCAPE_UDELAY) /* 2 seconds worth of udelays */
55 char escape_data[5]; /* longest vt100 escape sequence is 4 bytes */
56 char *ped = escape_data;
57 int escape_delay = 0;
58 get_char_func *f, *f_escape = NULL;
59 int key;
60
61 for (f = &kdb_poll_funcs[0]; ; ++f) {
62 if (*f == NULL) {
63 /* Reset NMI watchdog once per poll loop */
64 touch_nmi_watchdog();
65 f = &kdb_poll_funcs[0];
66 }
67 if (escape_delay == 2) {
68 *ped = '\0';
69 ped = escape_data;
70 --escape_delay;
71 }
72 if (escape_delay == 1) {
73 key = *ped++;
74 if (!*ped)
75 --escape_delay;
76 break;
77 }
78 key = (*f)();
79 if (key == -1) {
80 if (escape_delay) {
81 udelay(ESCAPE_UDELAY);
82 --escape_delay;
83 }
84 continue;
85 }
86 if (bufsize <= 2) {
87 if (key == '\r')
88 key = '\n';
89 *buffer++ = key;
90 *buffer = '\0';
91 return -1;
92 }
93 if (escape_delay == 0 && key == '\e') {
94 escape_delay = ESCAPE_DELAY;
95 ped = escape_data;
96 f_escape = f;
97 }
98 if (escape_delay) {
99 *ped++ = key;
100 if (f_escape != f) {
101 escape_delay = 2;
102 continue;
103 }
104 if (ped - escape_data == 1) {
105 /* \e */
106 continue;
107 } else if (ped - escape_data == 2) {
108 /* \e<something> */
109 if (key != '[')
110 escape_delay = 2;
111 continue;
112 } else if (ped - escape_data == 3) {
113 /* \e[<something> */
114 int mapkey = 0;
115 switch (key) {
116 case 'A': /* \e[A, up arrow */
117 mapkey = 16;
118 break;
119 case 'B': /* \e[B, down arrow */
120 mapkey = 14;
121 break;
122 case 'C': /* \e[C, right arrow */
123 mapkey = 6;
124 break;
125 case 'D': /* \e[D, left arrow */
126 mapkey = 2;
127 break;
128 case '1': /* dropthrough */
129 case '3': /* dropthrough */
130 /* \e[<1,3,4>], may be home, del, end */
131 case '4':
132 mapkey = -1;
133 break;
134 }
135 if (mapkey != -1) {
136 if (mapkey > 0) {
137 escape_data[0] = mapkey;
138 escape_data[1] = '\0';
139 }
140 escape_delay = 2;
141 }
142 continue;
143 } else if (ped - escape_data == 4) {
144 /* \e[<1,3,4><something> */
145 int mapkey = 0;
146 if (key == '~') {
147 switch (escape_data[2]) {
148 case '1': /* \e[1~, home */
149 mapkey = 1;
150 break;
151 case '3': /* \e[3~, del */
152 mapkey = 4;
153 break;
154 case '4': /* \e[4~, end */
155 mapkey = 5;
156 break;
157 }
158 }
159 if (mapkey > 0) {
160 escape_data[0] = mapkey;
161 escape_data[1] = '\0';
162 }
163 escape_delay = 2;
164 continue;
165 }
166 }
167 break; /* A key to process */
168 }
169 return key;
170}
171
172/*
173 * kdb_read
174 *
175 * This function reads a string of characters, terminated by
176 * a newline, or by reaching the end of the supplied buffer,
177 * from the current kernel debugger console device.
178 * Parameters:
179 * buffer - Address of character buffer to receive input characters.
180 * bufsize - size, in bytes, of the character buffer
181 * Returns:
182 * Returns a pointer to the buffer containing the received
183 * character string. This string will be terminated by a
184 * newline character.
185 * Locking:
186 * No locks are required to be held upon entry to this
187 * function. It is not reentrant - it relies on the fact
188 * that while kdb is running on only one "master debug" cpu.
189 * Remarks:
190 *
191 * The buffer size must be >= 2. A buffer size of 2 means that the caller only
192 * wants a single key.
193 *
194 * An escape key could be the start of a vt100 control sequence such as \e[D
195 * (left arrow) or it could be a character in its own right. The standard
196 * method for detecting the difference is to wait for 2 seconds to see if there
197 * are any other characters. kdb is complicated by the lack of a timer service
198 * (interrupts are off), by multiple input sources and by the need to sometimes
199 * return after just one key. Escape sequence processing has to be done as
200 * states in the polling loop.
201 */
202
203static char *kdb_read(char *buffer, size_t bufsize)
204{
205 char *cp = buffer;
206 char *bufend = buffer+bufsize-2; /* Reserve space for newline
207 * and null byte */
208 char *lastchar;
209 char *p_tmp;
210 char tmp;
211 static char tmpbuffer[CMD_BUFLEN];
212 int len = strlen(buffer);
213 int len_tmp;
214 int tab = 0;
215 int count;
216 int i;
217 int diag, dtab_count;
218 int key;
219
220
221 diag = kdbgetintenv("DTABCOUNT", &dtab_count);
222 if (diag)
223 dtab_count = 30;
224
225 if (len > 0) {
226 cp += len;
227 if (*(buffer+len-1) == '\n')
228 cp--;
229 }
230
231 lastchar = cp;
232 *cp = '\0';
233 kdb_printf("%s", buffer);
234poll_again:
235 key = kdb_read_get_key(buffer, bufsize);
236 if (key == -1)
237 return buffer;
238 if (key != 9)
239 tab = 0;
240 switch (key) {
241 case 8: /* backspace */
242 if (cp > buffer) {
243 if (cp < lastchar) {
244 memcpy(tmpbuffer, cp, lastchar - cp);
245 memcpy(cp-1, tmpbuffer, lastchar - cp);
246 }
247 *(--lastchar) = '\0';
248 --cp;
249 kdb_printf("\b%s \r", cp);
250 tmp = *cp;
251 *cp = '\0';
252 kdb_printf(kdb_prompt_str);
253 kdb_printf("%s", buffer);
254 *cp = tmp;
255 }
256 break;
257 case 13: /* enter */
258 *lastchar++ = '\n';
259 *lastchar++ = '\0';
260 if (!KDB_STATE(KGDB_TRANS)) {
261 KDB_STATE_SET(KGDB_TRANS);
262 kdb_printf("%s", buffer);
263 }
264 kdb_printf("\n");
265 return buffer;
266 case 4: /* Del */
267 if (cp < lastchar) {
268 memcpy(tmpbuffer, cp+1, lastchar - cp - 1);
269 memcpy(cp, tmpbuffer, lastchar - cp - 1);
270 *(--lastchar) = '\0';
271 kdb_printf("%s \r", cp);
272 tmp = *cp;
273 *cp = '\0';
274 kdb_printf(kdb_prompt_str);
275 kdb_printf("%s", buffer);
276 *cp = tmp;
277 }
278 break;
279 case 1: /* Home */
280 if (cp > buffer) {
281 kdb_printf("\r");
282 kdb_printf(kdb_prompt_str);
283 cp = buffer;
284 }
285 break;
286 case 5: /* End */
287 if (cp < lastchar) {
288 kdb_printf("%s", cp);
289 cp = lastchar;
290 }
291 break;
292 case 2: /* Left */
293 if (cp > buffer) {
294 kdb_printf("\b");
295 --cp;
296 }
297 break;
298 case 14: /* Down */
299 memset(tmpbuffer, ' ',
300 strlen(kdb_prompt_str) + (lastchar-buffer));
301 *(tmpbuffer+strlen(kdb_prompt_str) +
302 (lastchar-buffer)) = '\0';
303 kdb_printf("\r%s\r", tmpbuffer);
304 *lastchar = (char)key;
305 *(lastchar+1) = '\0';
306 return lastchar;
307 case 6: /* Right */
308 if (cp < lastchar) {
309 kdb_printf("%c", *cp);
310 ++cp;
311 }
312 break;
313 case 16: /* Up */
314 memset(tmpbuffer, ' ',
315 strlen(kdb_prompt_str) + (lastchar-buffer));
316 *(tmpbuffer+strlen(kdb_prompt_str) +
317 (lastchar-buffer)) = '\0';
318 kdb_printf("\r%s\r", tmpbuffer);
319 *lastchar = (char)key;
320 *(lastchar+1) = '\0';
321 return lastchar;
322 case 9: /* Tab */
323 if (tab < 2)
324 ++tab;
325 p_tmp = buffer;
326 while (*p_tmp == ' ')
327 p_tmp++;
328 if (p_tmp > cp)
329 break;
330 memcpy(tmpbuffer, p_tmp, cp-p_tmp);
331 *(tmpbuffer + (cp-p_tmp)) = '\0';
332 p_tmp = strrchr(tmpbuffer, ' ');
333 if (p_tmp)
334 ++p_tmp;
335 else
336 p_tmp = tmpbuffer;
337 len = strlen(p_tmp);
338 count = kallsyms_symbol_complete(p_tmp,
339 sizeof(tmpbuffer) -
340 (p_tmp - tmpbuffer));
341 if (tab == 2 && count > 0) {
342 kdb_printf("\n%d symbols are found.", count);
343 if (count > dtab_count) {
344 count = dtab_count;
345 kdb_printf(" But only first %d symbols will"
346 " be printed.\nYou can change the"
347 " environment variable DTABCOUNT.",
348 count);
349 }
350 kdb_printf("\n");
351 for (i = 0; i < count; i++) {
352 if (kallsyms_symbol_next(p_tmp, i) < 0)
353 break;
354 kdb_printf("%s ", p_tmp);
355 *(p_tmp + len) = '\0';
356 }
357 if (i >= dtab_count)
358 kdb_printf("...");
359 kdb_printf("\n");
360 kdb_printf(kdb_prompt_str);
361 kdb_printf("%s", buffer);
362 } else if (tab != 2 && count > 0) {
363 len_tmp = strlen(p_tmp);
364 strncpy(p_tmp+len_tmp, cp, lastchar-cp+1);
365 len_tmp = strlen(p_tmp);
366 strncpy(cp, p_tmp+len, len_tmp-len + 1);
367 len = len_tmp - len;
368 kdb_printf("%s", cp);
369 cp += len;
370 lastchar += len;
371 }
372 kdb_nextline = 1; /* reset output line number */
373 break;
374 default:
375 if (key >= 32 && lastchar < bufend) {
376 if (cp < lastchar) {
377 memcpy(tmpbuffer, cp, lastchar - cp);
378 memcpy(cp+1, tmpbuffer, lastchar - cp);
379 *++lastchar = '\0';
380 *cp = key;
381 kdb_printf("%s\r", cp);
382 ++cp;
383 tmp = *cp;
384 *cp = '\0';
385 kdb_printf(kdb_prompt_str);
386 kdb_printf("%s", buffer);
387 *cp = tmp;
388 } else {
389 *++lastchar = '\0';
390 *cp++ = key;
391 /* The kgdb transition check will hide
392 * printed characters if we think that
393 * kgdb is connecting, until the check
394 * fails */
395 if (!KDB_STATE(KGDB_TRANS)) {
396 if (kgdb_transition_check(buffer))
397 return buffer;
398 } else {
399 kdb_printf("%c", key);
400 }
401 }
402 /* Special escape to kgdb */
403 if (lastchar - buffer >= 5 &&
404 strcmp(lastchar - 5, "$?#3f") == 0) {
405 kdb_gdb_state_pass(lastchar - 5);
406 strcpy(buffer, "kgdb");
407 KDB_STATE_SET(DOING_KGDB);
408 return buffer;
409 }
410 if (lastchar - buffer >= 11 &&
411 strcmp(lastchar - 11, "$qSupported") == 0) {
412 kdb_gdb_state_pass(lastchar - 11);
413 strcpy(buffer, "kgdb");
414 KDB_STATE_SET(DOING_KGDB);
415 return buffer;
416 }
417 }
418 break;
419 }
420 goto poll_again;
421}
422
423/*
424 * kdb_getstr
425 *
426 * Print the prompt string and read a command from the
427 * input device.
428 *
429 * Parameters:
430 * buffer Address of buffer to receive command
431 * bufsize Size of buffer in bytes
432 * prompt Pointer to string to use as prompt string
433 * Returns:
434 * Pointer to command buffer.
435 * Locking:
436 * None.
437 * Remarks:
438 * For SMP kernels, the processor number will be
439 * substituted for %d, %x or %o in the prompt.
440 */
441
442char *kdb_getstr(char *buffer, size_t bufsize, char *prompt)
443{
444 if (prompt && kdb_prompt_str != prompt)
445 strncpy(kdb_prompt_str, prompt, CMD_BUFLEN);
446 kdb_printf(kdb_prompt_str);
447 kdb_nextline = 1; /* Prompt and input resets line number */
448 return kdb_read(buffer, bufsize);
449}
450
451/*
452 * kdb_input_flush
453 *
454 * Get rid of any buffered console input.
455 *
456 * Parameters:
457 * none
458 * Returns:
459 * nothing
460 * Locking:
461 * none
462 * Remarks:
463 * Call this function whenever you want to flush input. If there is any
464 * outstanding input, it ignores all characters until there has been no
465 * data for approximately 1ms.
466 */
467
468static void kdb_input_flush(void)
469{
470 get_char_func *f;
471 int res;
472 int flush_delay = 1;
473 while (flush_delay) {
474 flush_delay--;
475empty:
476 touch_nmi_watchdog();
477 for (f = &kdb_poll_funcs[0]; *f; ++f) {
478 res = (*f)();
479 if (res != -1) {
480 flush_delay = 1;
481 goto empty;
482 }
483 }
484 if (flush_delay)
485 mdelay(1);
486 }
487}
488
489/*
490 * kdb_printf
491 *
492 * Print a string to the output device(s).
493 *
494 * Parameters:
495 * printf-like format and optional args.
496 * Returns:
497 * 0
498 * Locking:
499 * None.
500 * Remarks:
501 * use 'kdbcons->write()' to avoid polluting 'log_buf' with
502 * kdb output.
503 *
504 * If the user is doing a cmd args | grep srch
505 * then kdb_grepping_flag is set.
506 * In that case we need to accumulate full lines (ending in \n) before
507 * searching for the pattern.
508 */
509
510static char kdb_buffer[256]; /* A bit too big to go on stack */
511static char *next_avail = kdb_buffer;
512static int size_avail;
513static int suspend_grep;
514
515/*
516 * search arg1 to see if it contains arg2
517 * (kdmain.c provides flags for ^pat and pat$)
518 *
519 * return 1 for found, 0 for not found
520 */
521static int kdb_search_string(char *searched, char *searchfor)
522{
523 char firstchar, *cp;
524 int len1, len2;
525
526 /* not counting the newline at the end of "searched" */
527 len1 = strlen(searched)-1;
528 len2 = strlen(searchfor);
529 if (len1 < len2)
530 return 0;
531 if (kdb_grep_leading && kdb_grep_trailing && len1 != len2)
532 return 0;
533 if (kdb_grep_leading) {
534 if (!strncmp(searched, searchfor, len2))
535 return 1;
536 } else if (kdb_grep_trailing) {
537 if (!strncmp(searched+len1-len2, searchfor, len2))
538 return 1;
539 } else {
540 firstchar = *searchfor;
541 cp = searched;
542 while ((cp = strchr(cp, firstchar))) {
543 if (!strncmp(cp, searchfor, len2))
544 return 1;
545 cp++;
546 }
547 }
548 return 0;
549}
550
551int vkdb_printf(const char *fmt, va_list ap)
552{
553 int diag;
554 int linecount;
555 int logging, saved_loglevel = 0;
556 int saved_trap_printk;
557 int got_printf_lock = 0;
558 int retlen = 0;
559 int fnd, len;
560 char *cp, *cp2, *cphold = NULL, replaced_byte = ' ';
561 char *moreprompt = "more> ";
562 struct console *c = console_drivers;
563 static DEFINE_SPINLOCK(kdb_printf_lock);
564 unsigned long uninitialized_var(flags);
565
566 preempt_disable();
567 saved_trap_printk = kdb_trap_printk;
568 kdb_trap_printk = 0;
569
570 /* Serialize kdb_printf if multiple cpus try to write at once.
571 * But if any cpu goes recursive in kdb, just print the output,
572 * even if it is interleaved with any other text.
573 */
574 if (!KDB_STATE(PRINTF_LOCK)) {
575 KDB_STATE_SET(PRINTF_LOCK);
576 spin_lock_irqsave(&kdb_printf_lock, flags);
577 got_printf_lock = 1;
578 atomic_inc(&kdb_event);
579 } else {
580 __acquire(kdb_printf_lock);
581 }
582
583 diag = kdbgetintenv("LINES", &linecount);
584 if (diag || linecount <= 1)
585 linecount = 24;
586
587 diag = kdbgetintenv("LOGGING", &logging);
588 if (diag)
589 logging = 0;
590
591 if (!kdb_grepping_flag || suspend_grep) {
592 /* normally, every vsnprintf starts a new buffer */
593 next_avail = kdb_buffer;
594 size_avail = sizeof(kdb_buffer);
595 }
596 vsnprintf(next_avail, size_avail, fmt, ap);
597
598 /*
599 * If kdb_parse() found that the command was cmd xxx | grep yyy
600 * then kdb_grepping_flag is set, and kdb_grep_string contains yyy
601 *
602 * Accumulate the print data up to a newline before searching it.
603 * (vsnprintf does null-terminate the string that it generates)
604 */
605
606 /* skip the search if prints are temporarily unconditional */
607 if (!suspend_grep && kdb_grepping_flag) {
608 cp = strchr(kdb_buffer, '\n');
609 if (!cp) {
610 /*
611 * Special cases that don't end with newlines
612 * but should be written without one:
613 * The "[nn]kdb> " prompt should
614 * appear at the front of the buffer.
615 *
616 * The "[nn]more " prompt should also be
617 * (MOREPROMPT -> moreprompt)
618 * written * but we print that ourselves,
619 * we set the suspend_grep flag to make
620 * it unconditional.
621 *
622 */
623 if (next_avail == kdb_buffer) {
624 /*
625 * these should occur after a newline,
626 * so they will be at the front of the
627 * buffer
628 */
629 cp2 = kdb_buffer;
630 len = strlen(kdb_prompt_str);
631 if (!strncmp(cp2, kdb_prompt_str, len)) {
632 /*
633 * We're about to start a new
634 * command, so we can go back
635 * to normal mode.
636 */
637 kdb_grepping_flag = 0;
638 goto kdb_printit;
639 }
640 }
641 /* no newline; don't search/write the buffer
642 until one is there */
643 len = strlen(kdb_buffer);
644 next_avail = kdb_buffer + len;
645 size_avail = sizeof(kdb_buffer) - len;
646 goto kdb_print_out;
647 }
648
649 /*
650 * The newline is present; print through it or discard
651 * it, depending on the results of the search.
652 */
653 cp++; /* to byte after the newline */
654 replaced_byte = *cp; /* remember what/where it was */
655 cphold = cp;
656 *cp = '\0'; /* end the string for our search */
657
658 /*
659 * We now have a newline at the end of the string
660 * Only continue with this output if it contains the
661 * search string.
662 */
663 fnd = kdb_search_string(kdb_buffer, kdb_grep_string);
664 if (!fnd) {
665 /*
666 * At this point the complete line at the start
667 * of kdb_buffer can be discarded, as it does
668 * not contain what the user is looking for.
669 * Shift the buffer left.
670 */
671 *cphold = replaced_byte;
672 strcpy(kdb_buffer, cphold);
673 len = strlen(kdb_buffer);
674 next_avail = kdb_buffer + len;
675 size_avail = sizeof(kdb_buffer) - len;
676 goto kdb_print_out;
677 }
678 /*
679 * at this point the string is a full line and
680 * should be printed, up to the null.
681 */
682 }
683kdb_printit:
684
685 /*
686 * Write to all consoles.
687 */
688 retlen = strlen(kdb_buffer);
689 if (!dbg_kdb_mode && kgdb_connected) {
690 gdbstub_msg_write(kdb_buffer, retlen);
691 } else {
692 if (dbg_io_ops && !dbg_io_ops->is_console) {
693 len = strlen(kdb_buffer);
694 cp = kdb_buffer;
695 while (len--) {
696 dbg_io_ops->write_char(*cp);
697 cp++;
698 }
699 }
700 while (c) {
701 c->write(c, kdb_buffer, retlen);
702 touch_nmi_watchdog();
703 c = c->next;
704 }
705 }
706 if (logging) {
707 saved_loglevel = console_loglevel;
708 console_loglevel = 0;
709 printk(KERN_INFO "%s", kdb_buffer);
710 }
711
712 if (KDB_STATE(PAGER) && strchr(kdb_buffer, '\n'))
713 kdb_nextline++;
714
715 /* check for having reached the LINES number of printed lines */
716 if (kdb_nextline == linecount) {
717 char buf1[16] = "";
718#if defined(CONFIG_SMP)
719 char buf2[32];
720#endif
721
722 /* Watch out for recursion here. Any routine that calls
723 * kdb_printf will come back through here. And kdb_read
724 * uses kdb_printf to echo on serial consoles ...
725 */
726 kdb_nextline = 1; /* In case of recursion */
727
728 /*
729 * Pause until cr.
730 */
731 moreprompt = kdbgetenv("MOREPROMPT");
732 if (moreprompt == NULL)
733 moreprompt = "more> ";
734
735#if defined(CONFIG_SMP)
736 if (strchr(moreprompt, '%')) {
737 sprintf(buf2, moreprompt, get_cpu());
738 put_cpu();
739 moreprompt = buf2;
740 }
741#endif
742
743 kdb_input_flush();
744 c = console_drivers;
745
746 if (dbg_io_ops && !dbg_io_ops->is_console) {
747 len = strlen(moreprompt);
748 cp = moreprompt;
749 while (len--) {
750 dbg_io_ops->write_char(*cp);
751 cp++;
752 }
753 }
754 while (c) {
755 c->write(c, moreprompt, strlen(moreprompt));
756 touch_nmi_watchdog();
757 c = c->next;
758 }
759
760 if (logging)
761 printk("%s", moreprompt);
762
763 kdb_read(buf1, 2); /* '2' indicates to return
764 * immediately after getting one key. */
765 kdb_nextline = 1; /* Really set output line 1 */
766
767 /* empty and reset the buffer: */
768 kdb_buffer[0] = '\0';
769 next_avail = kdb_buffer;
770 size_avail = sizeof(kdb_buffer);
771 if ((buf1[0] == 'q') || (buf1[0] == 'Q')) {
772 /* user hit q or Q */
773 KDB_FLAG_SET(CMD_INTERRUPT); /* command interrupted */
774 KDB_STATE_CLEAR(PAGER);
775 /* end of command output; back to normal mode */
776 kdb_grepping_flag = 0;
777 kdb_printf("\n");
778 } else if (buf1[0] == ' ') {
779 kdb_printf("\n");
780 suspend_grep = 1; /* for this recursion */
781 } else if (buf1[0] == '\n') {
782 kdb_nextline = linecount - 1;
783 kdb_printf("\r");
784 suspend_grep = 1; /* for this recursion */
785 } else if (buf1[0] && buf1[0] != '\n') {
786 /* user hit something other than enter */
787 suspend_grep = 1; /* for this recursion */
788 kdb_printf("\nOnly 'q' or 'Q' are processed at more "
789 "prompt, input ignored\n");
790 } else if (kdb_grepping_flag) {
791 /* user hit enter */
792 suspend_grep = 1; /* for this recursion */
793 kdb_printf("\n");
794 }
795 kdb_input_flush();
796 }
797
798 /*
799 * For grep searches, shift the printed string left.
800 * replaced_byte contains the character that was overwritten with
801 * the terminating null, and cphold points to the null.
802 * Then adjust the notion of available space in the buffer.
803 */
804 if (kdb_grepping_flag && !suspend_grep) {
805 *cphold = replaced_byte;
806 strcpy(kdb_buffer, cphold);
807 len = strlen(kdb_buffer);
808 next_avail = kdb_buffer + len;
809 size_avail = sizeof(kdb_buffer) - len;
810 }
811
812kdb_print_out:
813 suspend_grep = 0; /* end of what may have been a recursive call */
814 if (logging)
815 console_loglevel = saved_loglevel;
816 if (KDB_STATE(PRINTF_LOCK) && got_printf_lock) {
817 got_printf_lock = 0;
818 spin_unlock_irqrestore(&kdb_printf_lock, flags);
819 KDB_STATE_CLEAR(PRINTF_LOCK);
820 atomic_dec(&kdb_event);
821 } else {
822 __release(kdb_printf_lock);
823 }
824 kdb_trap_printk = saved_trap_printk;
825 preempt_enable();
826 return retlen;
827}
828
829int kdb_printf(const char *fmt, ...)
830{
831 va_list ap;
832 int r;
833
834 va_start(ap, fmt);
835 r = vkdb_printf(fmt, ap);
836 va_end(ap);
837
838 return r;
839}
840EXPORT_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 const char *cp;
549 int len;
550
551 if (msg_len == 0)
552 return;
553
554 cp = msg;
555 len = msg_len;
556
557 while (len--) {
558 dbg_io_ops->write_char(*cp);
559 cp++;
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. Replace the \0 with
713 * its original value to ensure multi-line strings
714 * are handled properly, and return to normal mode.
715 */
716 *cphold = replaced_byte;
717 kdb_grepping_flag = 0;
718 }
719 /*
720 * at this point the string is a full line and
721 * should be printed, up to the null.
722 */
723 }
724kdb_printit:
725
726 /*
727 * Write to all consoles.
728 */
729 retlen = strlen(kdb_buffer);
730 cp = (char *) printk_skip_headers(kdb_buffer);
731 if (!dbg_kdb_mode && kgdb_connected)
732 gdbstub_msg_write(cp, retlen - (cp - kdb_buffer));
733 else
734 kdb_msg_write(cp, retlen - (cp - kdb_buffer));
735
736 if (logging) {
737 saved_loglevel = console_loglevel;
738 console_loglevel = CONSOLE_LOGLEVEL_SILENT;
739 if (printk_get_level(kdb_buffer) || src == KDB_MSGSRC_PRINTK)
740 printk("%s", kdb_buffer);
741 else
742 pr_info("%s", kdb_buffer);
743 }
744
745 if (KDB_STATE(PAGER)) {
746 /*
747 * Check printed string to decide how to bump the
748 * kdb_nextline to control when the more prompt should
749 * show up.
750 */
751 int got = 0;
752 len = retlen;
753 while (len--) {
754 if (kdb_buffer[len] == '\n') {
755 kdb_nextline++;
756 got = 0;
757 } else if (kdb_buffer[len] == '\r') {
758 got = 0;
759 } else {
760 got++;
761 }
762 }
763 kdb_nextline += got / (colcount + 1);
764 }
765
766 /* check for having reached the LINES number of printed lines */
767 if (kdb_nextline >= linecount) {
768 char ch;
769
770 /* Watch out for recursion here. Any routine that calls
771 * kdb_printf will come back through here. And kdb_read
772 * uses kdb_printf to echo on serial consoles ...
773 */
774 kdb_nextline = 1; /* In case of recursion */
775
776 /*
777 * Pause until cr.
778 */
779 moreprompt = kdbgetenv("MOREPROMPT");
780 if (moreprompt == NULL)
781 moreprompt = "more> ";
782
783 kdb_input_flush();
784 kdb_msg_write(moreprompt, strlen(moreprompt));
785
786 if (logging)
787 printk("%s", moreprompt);
788
789 ch = kdb_getchar();
790 kdb_nextline = 1; /* Really set output line 1 */
791
792 /* empty and reset the buffer: */
793 kdb_buffer[0] = '\0';
794 next_avail = kdb_buffer;
795 size_avail = sizeof(kdb_buffer);
796 if ((ch == 'q') || (ch == 'Q')) {
797 /* user hit q or Q */
798 KDB_FLAG_SET(CMD_INTERRUPT); /* command interrupted */
799 KDB_STATE_CLEAR(PAGER);
800 /* end of command output; back to normal mode */
801 kdb_grepping_flag = 0;
802 kdb_printf("\n");
803 } else if (ch == ' ') {
804 kdb_printf("\r");
805 suspend_grep = 1; /* for this recursion */
806 } else if (ch == '\n' || ch == '\r') {
807 kdb_nextline = linecount - 1;
808 kdb_printf("\r");
809 suspend_grep = 1; /* for this recursion */
810 } else if (ch == '/' && !kdb_grepping_flag) {
811 kdb_printf("\r");
812 kdb_getstr(kdb_grep_string, KDB_GREP_STRLEN,
813 kdbgetenv("SEARCHPROMPT") ?: "search> ");
814 *strchrnul(kdb_grep_string, '\n') = '\0';
815 kdb_grepping_flag += KDB_GREPPING_FLAG_SEARCH;
816 suspend_grep = 1; /* for this recursion */
817 } else if (ch) {
818 /* user hit something unexpected */
819 suspend_grep = 1; /* for this recursion */
820 if (ch != '/')
821 kdb_printf(
822 "\nOnly 'q', 'Q' or '/' are processed at "
823 "more prompt, input ignored\n");
824 else
825 kdb_printf("\n'/' cannot be used during | "
826 "grep filtering, input ignored\n");
827 } else if (kdb_grepping_flag) {
828 /* user hit enter */
829 suspend_grep = 1; /* for this recursion */
830 kdb_printf("\n");
831 }
832 kdb_input_flush();
833 }
834
835 /*
836 * For grep searches, shift the printed string left.
837 * replaced_byte contains the character that was overwritten with
838 * the terminating null, and cphold points to the null.
839 * Then adjust the notion of available space in the buffer.
840 */
841 if (kdb_grepping_flag && !suspend_grep) {
842 *cphold = replaced_byte;
843 strcpy(kdb_buffer, cphold);
844 len = strlen(kdb_buffer);
845 next_avail = kdb_buffer + len;
846 size_avail = sizeof(kdb_buffer) - len;
847 }
848
849kdb_print_out:
850 suspend_grep = 0; /* end of what may have been a recursive call */
851 if (logging)
852 console_loglevel = saved_loglevel;
853 /* kdb_printf_cpu locked the code above. */
854 smp_store_release(&kdb_printf_cpu, old_cpu);
855 local_irq_restore(flags);
856 return retlen;
857}
858
859int kdb_printf(const char *fmt, ...)
860{
861 va_list ap;
862 int r;
863
864 va_start(ap, fmt);
865 r = vkdb_printf(KDB_MSGSRC_INTERNAL, fmt, ap);
866 va_end(ap);
867
868 return r;
869}
870EXPORT_SYMBOL_GPL(kdb_printf);