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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/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_read
189 *
190 * This function reads a string of characters, terminated by
191 * a newline, or by reaching the end of the supplied buffer,
192 * from the current kernel debugger console device.
193 * Parameters:
194 * buffer - Address of character buffer to receive input characters.
195 * bufsize - size, in bytes, of the character buffer
196 * Returns:
197 * Returns a pointer to the buffer containing the received
198 * character string. This string will be terminated by a
199 * newline character.
200 * Locking:
201 * No locks are required to be held upon entry to this
202 * function. It is not reentrant - it relies on the fact
203 * that while kdb is running on only one "master debug" cpu.
204 * Remarks:
205 * The buffer size must be >= 2.
206 */
207
208static char *kdb_read(char *buffer, size_t bufsize)
209{
210 char *cp = buffer;
211 char *bufend = buffer+bufsize-2; /* Reserve space for newline
212 * and null byte */
213 char *lastchar;
214 char *p_tmp;
215 char tmp;
216 static char tmpbuffer[CMD_BUFLEN];
217 int len = strlen(buffer);
218 int len_tmp;
219 int tab = 0;
220 int count;
221 int i;
222 int diag, dtab_count;
223 int key, buf_size, ret;
224
225
226 diag = kdbgetintenv("DTABCOUNT", &dtab_count);
227 if (diag)
228 dtab_count = 30;
229
230 if (len > 0) {
231 cp += len;
232 if (*(buffer+len-1) == '\n')
233 cp--;
234 }
235
236 lastchar = cp;
237 *cp = '\0';
238 kdb_printf("%s", buffer);
239poll_again:
240 key = kdb_getchar();
241 if (key != 9)
242 tab = 0;
243 switch (key) {
244 case 8: /* backspace */
245 if (cp > buffer) {
246 if (cp < lastchar) {
247 memcpy(tmpbuffer, cp, lastchar - cp);
248 memcpy(cp-1, tmpbuffer, lastchar - cp);
249 }
250 *(--lastchar) = '\0';
251 --cp;
252 kdb_printf("\b%s \r", cp);
253 tmp = *cp;
254 *cp = '\0';
255 kdb_printf(kdb_prompt_str);
256 kdb_printf("%s", buffer);
257 *cp = tmp;
258 }
259 break;
260 case 10: /* linefeed */
261 case 13: /* carriage return */
262 *lastchar++ = '\n';
263 *lastchar++ = '\0';
264 if (!KDB_STATE(KGDB_TRANS)) {
265 KDB_STATE_SET(KGDB_TRANS);
266 kdb_printf("%s", buffer);
267 }
268 kdb_printf("\n");
269 return buffer;
270 case 4: /* Del */
271 if (cp < lastchar) {
272 memcpy(tmpbuffer, cp+1, lastchar - cp - 1);
273 memcpy(cp, tmpbuffer, lastchar - cp - 1);
274 *(--lastchar) = '\0';
275 kdb_printf("%s \r", cp);
276 tmp = *cp;
277 *cp = '\0';
278 kdb_printf(kdb_prompt_str);
279 kdb_printf("%s", buffer);
280 *cp = tmp;
281 }
282 break;
283 case 1: /* Home */
284 if (cp > buffer) {
285 kdb_printf("\r");
286 kdb_printf(kdb_prompt_str);
287 cp = buffer;
288 }
289 break;
290 case 5: /* End */
291 if (cp < lastchar) {
292 kdb_printf("%s", cp);
293 cp = lastchar;
294 }
295 break;
296 case 2: /* Left */
297 if (cp > buffer) {
298 kdb_printf("\b");
299 --cp;
300 }
301 break;
302 case 14: /* Down */
303 memset(tmpbuffer, ' ',
304 strlen(kdb_prompt_str) + (lastchar-buffer));
305 *(tmpbuffer+strlen(kdb_prompt_str) +
306 (lastchar-buffer)) = '\0';
307 kdb_printf("\r%s\r", tmpbuffer);
308 *lastchar = (char)key;
309 *(lastchar+1) = '\0';
310 return lastchar;
311 case 6: /* Right */
312 if (cp < lastchar) {
313 kdb_printf("%c", *cp);
314 ++cp;
315 }
316 break;
317 case 16: /* Up */
318 memset(tmpbuffer, ' ',
319 strlen(kdb_prompt_str) + (lastchar-buffer));
320 *(tmpbuffer+strlen(kdb_prompt_str) +
321 (lastchar-buffer)) = '\0';
322 kdb_printf("\r%s\r", tmpbuffer);
323 *lastchar = (char)key;
324 *(lastchar+1) = '\0';
325 return lastchar;
326 case 9: /* Tab */
327 if (tab < 2)
328 ++tab;
329 p_tmp = buffer;
330 while (*p_tmp == ' ')
331 p_tmp++;
332 if (p_tmp > cp)
333 break;
334 memcpy(tmpbuffer, p_tmp, cp-p_tmp);
335 *(tmpbuffer + (cp-p_tmp)) = '\0';
336 p_tmp = strrchr(tmpbuffer, ' ');
337 if (p_tmp)
338 ++p_tmp;
339 else
340 p_tmp = tmpbuffer;
341 len = strlen(p_tmp);
342 buf_size = sizeof(tmpbuffer) - (p_tmp - tmpbuffer);
343 count = kallsyms_symbol_complete(p_tmp, buf_size);
344 if (tab == 2 && count > 0) {
345 kdb_printf("\n%d symbols are found.", count);
346 if (count > dtab_count) {
347 count = dtab_count;
348 kdb_printf(" But only first %d symbols will"
349 " be printed.\nYou can change the"
350 " environment variable DTABCOUNT.",
351 count);
352 }
353 kdb_printf("\n");
354 for (i = 0; i < count; i++) {
355 ret = kallsyms_symbol_next(p_tmp, i, buf_size);
356 if (WARN_ON(!ret))
357 break;
358 if (ret != -E2BIG)
359 kdb_printf("%s ", p_tmp);
360 else
361 kdb_printf("%s... ", p_tmp);
362 *(p_tmp + len) = '\0';
363 }
364 if (i >= dtab_count)
365 kdb_printf("...");
366 kdb_printf("\n");
367 kdb_printf(kdb_prompt_str);
368 kdb_printf("%s", buffer);
369 } else if (tab != 2 && count > 0) {
370 len_tmp = strlen(p_tmp);
371 strncpy(p_tmp+len_tmp, cp, lastchar-cp+1);
372 len_tmp = strlen(p_tmp);
373 strncpy(cp, p_tmp+len, len_tmp-len + 1);
374 len = len_tmp - len;
375 kdb_printf("%s", cp);
376 cp += len;
377 lastchar += len;
378 }
379 kdb_nextline = 1; /* reset output line number */
380 break;
381 default:
382 if (key >= 32 && lastchar < bufend) {
383 if (cp < lastchar) {
384 memcpy(tmpbuffer, cp, lastchar - cp);
385 memcpy(cp+1, tmpbuffer, lastchar - cp);
386 *++lastchar = '\0';
387 *cp = key;
388 kdb_printf("%s\r", cp);
389 ++cp;
390 tmp = *cp;
391 *cp = '\0';
392 kdb_printf(kdb_prompt_str);
393 kdb_printf("%s", buffer);
394 *cp = tmp;
395 } else {
396 *++lastchar = '\0';
397 *cp++ = key;
398 /* The kgdb transition check will hide
399 * printed characters if we think that
400 * kgdb is connecting, until the check
401 * fails */
402 if (!KDB_STATE(KGDB_TRANS)) {
403 if (kgdb_transition_check(buffer))
404 return buffer;
405 } else {
406 kdb_printf("%c", key);
407 }
408 }
409 /* Special escape to kgdb */
410 if (lastchar - buffer >= 5 &&
411 strcmp(lastchar - 5, "$?#3f") == 0) {
412 kdb_gdb_state_pass(lastchar - 5);
413 strcpy(buffer, "kgdb");
414 KDB_STATE_SET(DOING_KGDB);
415 return buffer;
416 }
417 if (lastchar - buffer >= 11 &&
418 strcmp(lastchar - 11, "$qSupported") == 0) {
419 kdb_gdb_state_pass(lastchar - 11);
420 strcpy(buffer, "kgdb");
421 KDB_STATE_SET(DOING_KGDB);
422 return buffer;
423 }
424 }
425 break;
426 }
427 goto poll_again;
428}
429
430/*
431 * kdb_getstr
432 *
433 * Print the prompt string and read a command from the
434 * input device.
435 *
436 * Parameters:
437 * buffer Address of buffer to receive command
438 * bufsize Size of buffer in bytes
439 * prompt Pointer to string to use as prompt string
440 * Returns:
441 * Pointer to command buffer.
442 * Locking:
443 * None.
444 * Remarks:
445 * For SMP kernels, the processor number will be
446 * substituted for %d, %x or %o in the prompt.
447 */
448
449char *kdb_getstr(char *buffer, size_t bufsize, const char *prompt)
450{
451 if (prompt && kdb_prompt_str != prompt)
452 strscpy(kdb_prompt_str, prompt, CMD_BUFLEN);
453 kdb_printf(kdb_prompt_str);
454 kdb_nextline = 1; /* Prompt and input resets line number */
455 return kdb_read(buffer, bufsize);
456}
457
458/*
459 * kdb_input_flush
460 *
461 * Get rid of any buffered console input.
462 *
463 * Parameters:
464 * none
465 * Returns:
466 * nothing
467 * Locking:
468 * none
469 * Remarks:
470 * Call this function whenever you want to flush input. If there is any
471 * outstanding input, it ignores all characters until there has been no
472 * data for approximately 1ms.
473 */
474
475static void kdb_input_flush(void)
476{
477 get_char_func *f;
478 int res;
479 int flush_delay = 1;
480 while (flush_delay) {
481 flush_delay--;
482empty:
483 touch_nmi_watchdog();
484 for (f = &kdb_poll_funcs[0]; *f; ++f) {
485 res = (*f)();
486 if (res != -1) {
487 flush_delay = 1;
488 goto empty;
489 }
490 }
491 if (flush_delay)
492 mdelay(1);
493 }
494}
495
496/*
497 * kdb_printf
498 *
499 * Print a string to the output device(s).
500 *
501 * Parameters:
502 * printf-like format and optional args.
503 * Returns:
504 * 0
505 * Locking:
506 * None.
507 * Remarks:
508 * use 'kdbcons->write()' to avoid polluting 'log_buf' with
509 * kdb output.
510 *
511 * If the user is doing a cmd args | grep srch
512 * then kdb_grepping_flag is set.
513 * In that case we need to accumulate full lines (ending in \n) before
514 * searching for the pattern.
515 */
516
517static char kdb_buffer[256]; /* A bit too big to go on stack */
518static char *next_avail = kdb_buffer;
519static int size_avail;
520static int suspend_grep;
521
522/*
523 * search arg1 to see if it contains arg2
524 * (kdmain.c provides flags for ^pat and pat$)
525 *
526 * return 1 for found, 0 for not found
527 */
528static int kdb_search_string(char *searched, char *searchfor)
529{
530 char firstchar, *cp;
531 int len1, len2;
532
533 /* not counting the newline at the end of "searched" */
534 len1 = strlen(searched)-1;
535 len2 = strlen(searchfor);
536 if (len1 < len2)
537 return 0;
538 if (kdb_grep_leading && kdb_grep_trailing && len1 != len2)
539 return 0;
540 if (kdb_grep_leading) {
541 if (!strncmp(searched, searchfor, len2))
542 return 1;
543 } else if (kdb_grep_trailing) {
544 if (!strncmp(searched+len1-len2, searchfor, len2))
545 return 1;
546 } else {
547 firstchar = *searchfor;
548 cp = searched;
549 while ((cp = strchr(cp, firstchar))) {
550 if (!strncmp(cp, searchfor, len2))
551 return 1;
552 cp++;
553 }
554 }
555 return 0;
556}
557
558static void kdb_msg_write(const char *msg, int msg_len)
559{
560 struct console *c;
561 const char *cp;
562 int cookie;
563 int len;
564
565 if (msg_len == 0)
566 return;
567
568 cp = msg;
569 len = msg_len;
570
571 while (len--) {
572 dbg_io_ops->write_char(*cp);
573 cp++;
574 }
575
576 /*
577 * The console_srcu_read_lock() only provides safe console list
578 * traversal. The use of the ->write() callback relies on all other
579 * CPUs being stopped at the moment and console drivers being able to
580 * handle reentrance when @oops_in_progress is set.
581 *
582 * There is no guarantee that every console driver can handle
583 * reentrance in this way; the developer deploying the debugger
584 * is responsible for ensuring that the console drivers they
585 * have selected handle reentrance appropriately.
586 */
587 cookie = console_srcu_read_lock();
588 for_each_console_srcu(c) {
589 if (!(console_srcu_read_flags(c) & CON_ENABLED))
590 continue;
591 if (c == dbg_io_ops->cons)
592 continue;
593 if (!c->write)
594 continue;
595 /*
596 * Set oops_in_progress to encourage the console drivers to
597 * disregard their internal spin locks: in the current calling
598 * context the risk of deadlock is a bigger problem than risks
599 * due to re-entering the console driver. We operate directly on
600 * oops_in_progress rather than using bust_spinlocks() because
601 * the calls bust_spinlocks() makes on exit are not appropriate
602 * for this calling context.
603 */
604 ++oops_in_progress;
605 c->write(c, msg, msg_len);
606 --oops_in_progress;
607 touch_nmi_watchdog();
608 }
609 console_srcu_read_unlock(cookie);
610}
611
612int vkdb_printf(enum kdb_msgsrc src, const char *fmt, va_list ap)
613{
614 int diag;
615 int linecount;
616 int colcount;
617 int logging, saved_loglevel = 0;
618 int retlen = 0;
619 int fnd, len;
620 int this_cpu, old_cpu;
621 char *cp, *cp2, *cphold = NULL, replaced_byte = ' ';
622 char *moreprompt = "more> ";
623 unsigned long flags;
624
625 /* Serialize kdb_printf if multiple cpus try to write at once.
626 * But if any cpu goes recursive in kdb, just print the output,
627 * even if it is interleaved with any other text.
628 */
629 local_irq_save(flags);
630 this_cpu = smp_processor_id();
631 for (;;) {
632 old_cpu = cmpxchg(&kdb_printf_cpu, -1, this_cpu);
633 if (old_cpu == -1 || old_cpu == this_cpu)
634 break;
635
636 cpu_relax();
637 }
638
639 diag = kdbgetintenv("LINES", &linecount);
640 if (diag || linecount <= 1)
641 linecount = 24;
642
643 diag = kdbgetintenv("COLUMNS", &colcount);
644 if (diag || colcount <= 1)
645 colcount = 80;
646
647 diag = kdbgetintenv("LOGGING", &logging);
648 if (diag)
649 logging = 0;
650
651 if (!kdb_grepping_flag || suspend_grep) {
652 /* normally, every vsnprintf starts a new buffer */
653 next_avail = kdb_buffer;
654 size_avail = sizeof(kdb_buffer);
655 }
656 vsnprintf(next_avail, size_avail, fmt, ap);
657
658 /*
659 * If kdb_parse() found that the command was cmd xxx | grep yyy
660 * then kdb_grepping_flag is set, and kdb_grep_string contains yyy
661 *
662 * Accumulate the print data up to a newline before searching it.
663 * (vsnprintf does null-terminate the string that it generates)
664 */
665
666 /* skip the search if prints are temporarily unconditional */
667 if (!suspend_grep && kdb_grepping_flag) {
668 cp = strchr(kdb_buffer, '\n');
669 if (!cp) {
670 /*
671 * Special cases that don't end with newlines
672 * but should be written without one:
673 * The "[nn]kdb> " prompt should
674 * appear at the front of the buffer.
675 *
676 * The "[nn]more " prompt should also be
677 * (MOREPROMPT -> moreprompt)
678 * written * but we print that ourselves,
679 * we set the suspend_grep flag to make
680 * it unconditional.
681 *
682 */
683 if (next_avail == kdb_buffer) {
684 /*
685 * these should occur after a newline,
686 * so they will be at the front of the
687 * buffer
688 */
689 cp2 = kdb_buffer;
690 len = strlen(kdb_prompt_str);
691 if (!strncmp(cp2, kdb_prompt_str, len)) {
692 /*
693 * We're about to start a new
694 * command, so we can go back
695 * to normal mode.
696 */
697 kdb_grepping_flag = 0;
698 goto kdb_printit;
699 }
700 }
701 /* no newline; don't search/write the buffer
702 until one is there */
703 len = strlen(kdb_buffer);
704 next_avail = kdb_buffer + len;
705 size_avail = sizeof(kdb_buffer) - len;
706 goto kdb_print_out;
707 }
708
709 /*
710 * The newline is present; print through it or discard
711 * it, depending on the results of the search.
712 */
713 cp++; /* to byte after the newline */
714 replaced_byte = *cp; /* remember what/where it was */
715 cphold = cp;
716 *cp = '\0'; /* end the string for our search */
717
718 /*
719 * We now have a newline at the end of the string
720 * Only continue with this output if it contains the
721 * search string.
722 */
723 fnd = kdb_search_string(kdb_buffer, kdb_grep_string);
724 if (!fnd) {
725 /*
726 * At this point the complete line at the start
727 * of kdb_buffer can be discarded, as it does
728 * not contain what the user is looking for.
729 * Shift the buffer left.
730 */
731 *cphold = replaced_byte;
732 strcpy(kdb_buffer, cphold);
733 len = strlen(kdb_buffer);
734 next_avail = kdb_buffer + len;
735 size_avail = sizeof(kdb_buffer) - len;
736 goto kdb_print_out;
737 }
738 if (kdb_grepping_flag >= KDB_GREPPING_FLAG_SEARCH) {
739 /*
740 * This was a interactive search (using '/' at more
741 * prompt) and it has completed. Replace the \0 with
742 * its original value to ensure multi-line strings
743 * are handled properly, and return to normal mode.
744 */
745 *cphold = replaced_byte;
746 kdb_grepping_flag = 0;
747 }
748 /*
749 * at this point the string is a full line and
750 * should be printed, up to the null.
751 */
752 }
753kdb_printit:
754
755 /*
756 * Write to all consoles.
757 */
758 retlen = strlen(kdb_buffer);
759 cp = (char *) printk_skip_headers(kdb_buffer);
760 if (!dbg_kdb_mode && kgdb_connected)
761 gdbstub_msg_write(cp, retlen - (cp - kdb_buffer));
762 else
763 kdb_msg_write(cp, retlen - (cp - kdb_buffer));
764
765 if (logging) {
766 saved_loglevel = console_loglevel;
767 console_loglevel = CONSOLE_LOGLEVEL_SILENT;
768 if (printk_get_level(kdb_buffer) || src == KDB_MSGSRC_PRINTK)
769 printk("%s", kdb_buffer);
770 else
771 pr_info("%s", kdb_buffer);
772 }
773
774 if (KDB_STATE(PAGER)) {
775 /*
776 * Check printed string to decide how to bump the
777 * kdb_nextline to control when the more prompt should
778 * show up.
779 */
780 int got = 0;
781 len = retlen;
782 while (len--) {
783 if (kdb_buffer[len] == '\n') {
784 kdb_nextline++;
785 got = 0;
786 } else if (kdb_buffer[len] == '\r') {
787 got = 0;
788 } else {
789 got++;
790 }
791 }
792 kdb_nextline += got / (colcount + 1);
793 }
794
795 /* check for having reached the LINES number of printed lines */
796 if (kdb_nextline >= linecount) {
797 char ch;
798
799 /* Watch out for recursion here. Any routine that calls
800 * kdb_printf will come back through here. And kdb_read
801 * uses kdb_printf to echo on serial consoles ...
802 */
803 kdb_nextline = 1; /* In case of recursion */
804
805 /*
806 * Pause until cr.
807 */
808 moreprompt = kdbgetenv("MOREPROMPT");
809 if (moreprompt == NULL)
810 moreprompt = "more> ";
811
812 kdb_input_flush();
813 kdb_msg_write(moreprompt, strlen(moreprompt));
814
815 if (logging)
816 printk("%s", moreprompt);
817
818 ch = kdb_getchar();
819 kdb_nextline = 1; /* Really set output line 1 */
820
821 /* empty and reset the buffer: */
822 kdb_buffer[0] = '\0';
823 next_avail = kdb_buffer;
824 size_avail = sizeof(kdb_buffer);
825 if ((ch == 'q') || (ch == 'Q')) {
826 /* user hit q or Q */
827 KDB_FLAG_SET(CMD_INTERRUPT); /* command interrupted */
828 KDB_STATE_CLEAR(PAGER);
829 /* end of command output; back to normal mode */
830 kdb_grepping_flag = 0;
831 kdb_printf("\n");
832 } else if (ch == ' ') {
833 kdb_printf("\r");
834 suspend_grep = 1; /* for this recursion */
835 } else if (ch == '\n' || ch == '\r') {
836 kdb_nextline = linecount - 1;
837 kdb_printf("\r");
838 suspend_grep = 1; /* for this recursion */
839 } else if (ch == '/' && !kdb_grepping_flag) {
840 kdb_printf("\r");
841 kdb_getstr(kdb_grep_string, KDB_GREP_STRLEN,
842 kdbgetenv("SEARCHPROMPT") ?: "search> ");
843 *strchrnul(kdb_grep_string, '\n') = '\0';
844 kdb_grepping_flag += KDB_GREPPING_FLAG_SEARCH;
845 suspend_grep = 1; /* for this recursion */
846 } else if (ch) {
847 /* user hit something unexpected */
848 suspend_grep = 1; /* for this recursion */
849 if (ch != '/')
850 kdb_printf(
851 "\nOnly 'q', 'Q' or '/' are processed at "
852 "more prompt, input ignored\n");
853 else
854 kdb_printf("\n'/' cannot be used during | "
855 "grep filtering, input ignored\n");
856 } else if (kdb_grepping_flag) {
857 /* user hit enter */
858 suspend_grep = 1; /* for this recursion */
859 kdb_printf("\n");
860 }
861 kdb_input_flush();
862 }
863
864 /*
865 * For grep searches, shift the printed string left.
866 * replaced_byte contains the character that was overwritten with
867 * the terminating null, and cphold points to the null.
868 * Then adjust the notion of available space in the buffer.
869 */
870 if (kdb_grepping_flag && !suspend_grep) {
871 *cphold = replaced_byte;
872 strcpy(kdb_buffer, cphold);
873 len = strlen(kdb_buffer);
874 next_avail = kdb_buffer + len;
875 size_avail = sizeof(kdb_buffer) - len;
876 }
877
878kdb_print_out:
879 suspend_grep = 0; /* end of what may have been a recursive call */
880 if (logging)
881 console_loglevel = saved_loglevel;
882 /* kdb_printf_cpu locked the code above. */
883 smp_store_release(&kdb_printf_cpu, old_cpu);
884 local_irq_restore(flags);
885 return retlen;
886}
887
888int kdb_printf(const char *fmt, ...)
889{
890 va_list ap;
891 int r;
892
893 va_start(ap, fmt);
894 r = vkdb_printf(KDB_MSGSRC_INTERNAL, fmt, ap);
895 va_end(ap);
896
897 return r;
898}
899EXPORT_SYMBOL_GPL(kdb_printf);