Loading...
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);
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);