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