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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/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
135 for (f = &kdb_poll_funcs[0]; ; ++f) {
136 if (*f == NULL) {
137 /* Reset NMI watchdog once per poll loop */
138 touch_nmi_watchdog();
139 f = &kdb_poll_funcs[0];
140 }
141
142 key = (*f)();
143 if (key == -1) {
144 if (escape_delay) {
145 udelay(ESCAPE_UDELAY);
146 if (--escape_delay == 0)
147 return '\e';
148 }
149 continue;
150 }
151
152 /*
153 * When the first character is received (or we get a change
154 * input source) we set ourselves up to handle an escape
155 * sequences (just in case).
156 */
157 if (f_prev != f) {
158 f_prev = f;
159 pbuf = buf;
160 escape_delay = ESCAPE_DELAY;
161 }
162
163 *pbuf++ = key;
164 key = kdb_handle_escape(buf, pbuf - buf);
165 if (key < 0) /* no escape sequence; return best character */
166 return buf[pbuf - buf == 2 ? 1 : 0];
167 if (key > 0)
168 return key;
169 }
170
171 unreachable();
172}
173
174/*
175 * kdb_read
176 *
177 * This function reads a string of characters, terminated by
178 * a newline, or by reaching the end of the supplied buffer,
179 * from the current kernel debugger console device.
180 * Parameters:
181 * buffer - Address of character buffer to receive input characters.
182 * bufsize - size, in bytes, of the character buffer
183 * Returns:
184 * Returns a pointer to the buffer containing the received
185 * character string. This string will be terminated by a
186 * newline character.
187 * Locking:
188 * No locks are required to be held upon entry to this
189 * function. It is not reentrant - it relies on the fact
190 * that while kdb is running on only one "master debug" cpu.
191 * Remarks:
192 * The buffer size must be >= 2.
193 */
194
195static char *kdb_read(char *buffer, size_t bufsize)
196{
197 char *cp = buffer;
198 char *bufend = buffer+bufsize-2; /* Reserve space for newline
199 * and null byte */
200 char *lastchar;
201 char *p_tmp;
202 char tmp;
203 static char tmpbuffer[CMD_BUFLEN];
204 int len = strlen(buffer);
205 int len_tmp;
206 int tab = 0;
207 int count;
208 int i;
209 int diag, dtab_count;
210 int key, buf_size, ret;
211
212
213 diag = kdbgetintenv("DTABCOUNT", &dtab_count);
214 if (diag)
215 dtab_count = 30;
216
217 if (len > 0) {
218 cp += len;
219 if (*(buffer+len-1) == '\n')
220 cp--;
221 }
222
223 lastchar = cp;
224 *cp = '\0';
225 kdb_printf("%s", buffer);
226poll_again:
227 key = kdb_getchar();
228 if (key != 9)
229 tab = 0;
230 switch (key) {
231 case 8: /* backspace */
232 if (cp > buffer) {
233 if (cp < lastchar) {
234 memcpy(tmpbuffer, cp, lastchar - cp);
235 memcpy(cp-1, tmpbuffer, lastchar - cp);
236 }
237 *(--lastchar) = '\0';
238 --cp;
239 kdb_printf("\b%s \r", cp);
240 tmp = *cp;
241 *cp = '\0';
242 kdb_printf(kdb_prompt_str);
243 kdb_printf("%s", buffer);
244 *cp = tmp;
245 }
246 break;
247 case 13: /* enter */
248 *lastchar++ = '\n';
249 *lastchar++ = '\0';
250 if (!KDB_STATE(KGDB_TRANS)) {
251 KDB_STATE_SET(KGDB_TRANS);
252 kdb_printf("%s", buffer);
253 }
254 kdb_printf("\n");
255 return buffer;
256 case 4: /* Del */
257 if (cp < lastchar) {
258 memcpy(tmpbuffer, cp+1, lastchar - cp - 1);
259 memcpy(cp, tmpbuffer, lastchar - cp - 1);
260 *(--lastchar) = '\0';
261 kdb_printf("%s \r", cp);
262 tmp = *cp;
263 *cp = '\0';
264 kdb_printf(kdb_prompt_str);
265 kdb_printf("%s", buffer);
266 *cp = tmp;
267 }
268 break;
269 case 1: /* Home */
270 if (cp > buffer) {
271 kdb_printf("\r");
272 kdb_printf(kdb_prompt_str);
273 cp = buffer;
274 }
275 break;
276 case 5: /* End */
277 if (cp < lastchar) {
278 kdb_printf("%s", cp);
279 cp = lastchar;
280 }
281 break;
282 case 2: /* Left */
283 if (cp > buffer) {
284 kdb_printf("\b");
285 --cp;
286 }
287 break;
288 case 14: /* Down */
289 memset(tmpbuffer, ' ',
290 strlen(kdb_prompt_str) + (lastchar-buffer));
291 *(tmpbuffer+strlen(kdb_prompt_str) +
292 (lastchar-buffer)) = '\0';
293 kdb_printf("\r%s\r", tmpbuffer);
294 *lastchar = (char)key;
295 *(lastchar+1) = '\0';
296 return lastchar;
297 case 6: /* Right */
298 if (cp < lastchar) {
299 kdb_printf("%c", *cp);
300 ++cp;
301 }
302 break;
303 case 16: /* Up */
304 memset(tmpbuffer, ' ',
305 strlen(kdb_prompt_str) + (lastchar-buffer));
306 *(tmpbuffer+strlen(kdb_prompt_str) +
307 (lastchar-buffer)) = '\0';
308 kdb_printf("\r%s\r", tmpbuffer);
309 *lastchar = (char)key;
310 *(lastchar+1) = '\0';
311 return lastchar;
312 case 9: /* Tab */
313 if (tab < 2)
314 ++tab;
315 p_tmp = buffer;
316 while (*p_tmp == ' ')
317 p_tmp++;
318 if (p_tmp > cp)
319 break;
320 memcpy(tmpbuffer, p_tmp, cp-p_tmp);
321 *(tmpbuffer + (cp-p_tmp)) = '\0';
322 p_tmp = strrchr(tmpbuffer, ' ');
323 if (p_tmp)
324 ++p_tmp;
325 else
326 p_tmp = tmpbuffer;
327 len = strlen(p_tmp);
328 buf_size = sizeof(tmpbuffer) - (p_tmp - tmpbuffer);
329 count = kallsyms_symbol_complete(p_tmp, buf_size);
330 if (tab == 2 && count > 0) {
331 kdb_printf("\n%d symbols are found.", count);
332 if (count > dtab_count) {
333 count = dtab_count;
334 kdb_printf(" But only first %d symbols will"
335 " be printed.\nYou can change the"
336 " environment variable DTABCOUNT.",
337 count);
338 }
339 kdb_printf("\n");
340 for (i = 0; i < count; i++) {
341 ret = kallsyms_symbol_next(p_tmp, i, buf_size);
342 if (WARN_ON(!ret))
343 break;
344 if (ret != -E2BIG)
345 kdb_printf("%s ", p_tmp);
346 else
347 kdb_printf("%s... ", p_tmp);
348 *(p_tmp + len) = '\0';
349 }
350 if (i >= dtab_count)
351 kdb_printf("...");
352 kdb_printf("\n");
353 kdb_printf(kdb_prompt_str);
354 kdb_printf("%s", buffer);
355 } else if (tab != 2 && count > 0) {
356 len_tmp = strlen(p_tmp);
357 strncpy(p_tmp+len_tmp, cp, lastchar-cp+1);
358 len_tmp = strlen(p_tmp);
359 strncpy(cp, p_tmp+len, len_tmp-len + 1);
360 len = len_tmp - len;
361 kdb_printf("%s", cp);
362 cp += len;
363 lastchar += len;
364 }
365 kdb_nextline = 1; /* reset output line number */
366 break;
367 default:
368 if (key >= 32 && lastchar < bufend) {
369 if (cp < lastchar) {
370 memcpy(tmpbuffer, cp, lastchar - cp);
371 memcpy(cp+1, tmpbuffer, lastchar - cp);
372 *++lastchar = '\0';
373 *cp = key;
374 kdb_printf("%s\r", cp);
375 ++cp;
376 tmp = *cp;
377 *cp = '\0';
378 kdb_printf(kdb_prompt_str);
379 kdb_printf("%s", buffer);
380 *cp = tmp;
381 } else {
382 *++lastchar = '\0';
383 *cp++ = key;
384 /* The kgdb transition check will hide
385 * printed characters if we think that
386 * kgdb is connecting, until the check
387 * fails */
388 if (!KDB_STATE(KGDB_TRANS)) {
389 if (kgdb_transition_check(buffer))
390 return buffer;
391 } else {
392 kdb_printf("%c", key);
393 }
394 }
395 /* Special escape to kgdb */
396 if (lastchar - buffer >= 5 &&
397 strcmp(lastchar - 5, "$?#3f") == 0) {
398 kdb_gdb_state_pass(lastchar - 5);
399 strcpy(buffer, "kgdb");
400 KDB_STATE_SET(DOING_KGDB);
401 return buffer;
402 }
403 if (lastchar - buffer >= 11 &&
404 strcmp(lastchar - 11, "$qSupported") == 0) {
405 kdb_gdb_state_pass(lastchar - 11);
406 strcpy(buffer, "kgdb");
407 KDB_STATE_SET(DOING_KGDB);
408 return buffer;
409 }
410 }
411 break;
412 }
413 goto poll_again;
414}
415
416/*
417 * kdb_getstr
418 *
419 * Print the prompt string and read a command from the
420 * input device.
421 *
422 * Parameters:
423 * buffer Address of buffer to receive command
424 * bufsize Size of buffer in bytes
425 * prompt Pointer to string to use as prompt string
426 * Returns:
427 * Pointer to command buffer.
428 * Locking:
429 * None.
430 * Remarks:
431 * For SMP kernels, the processor number will be
432 * substituted for %d, %x or %o in the prompt.
433 */
434
435char *kdb_getstr(char *buffer, size_t bufsize, const char *prompt)
436{
437 if (prompt && kdb_prompt_str != prompt)
438 strscpy(kdb_prompt_str, prompt, CMD_BUFLEN);
439 kdb_printf(kdb_prompt_str);
440 kdb_nextline = 1; /* Prompt and input resets line number */
441 return kdb_read(buffer, bufsize);
442}
443
444/*
445 * kdb_input_flush
446 *
447 * Get rid of any buffered console input.
448 *
449 * Parameters:
450 * none
451 * Returns:
452 * nothing
453 * Locking:
454 * none
455 * Remarks:
456 * Call this function whenever you want to flush input. If there is any
457 * outstanding input, it ignores all characters until there has been no
458 * data for approximately 1ms.
459 */
460
461static void kdb_input_flush(void)
462{
463 get_char_func *f;
464 int res;
465 int flush_delay = 1;
466 while (flush_delay) {
467 flush_delay--;
468empty:
469 touch_nmi_watchdog();
470 for (f = &kdb_poll_funcs[0]; *f; ++f) {
471 res = (*f)();
472 if (res != -1) {
473 flush_delay = 1;
474 goto empty;
475 }
476 }
477 if (flush_delay)
478 mdelay(1);
479 }
480}
481
482/*
483 * kdb_printf
484 *
485 * Print a string to the output device(s).
486 *
487 * Parameters:
488 * printf-like format and optional args.
489 * Returns:
490 * 0
491 * Locking:
492 * None.
493 * Remarks:
494 * use 'kdbcons->write()' to avoid polluting 'log_buf' with
495 * kdb output.
496 *
497 * If the user is doing a cmd args | grep srch
498 * then kdb_grepping_flag is set.
499 * In that case we need to accumulate full lines (ending in \n) before
500 * searching for the pattern.
501 */
502
503static char kdb_buffer[256]; /* A bit too big to go on stack */
504static char *next_avail = kdb_buffer;
505static int size_avail;
506static int suspend_grep;
507
508/*
509 * search arg1 to see if it contains arg2
510 * (kdmain.c provides flags for ^pat and pat$)
511 *
512 * return 1 for found, 0 for not found
513 */
514static int kdb_search_string(char *searched, char *searchfor)
515{
516 char firstchar, *cp;
517 int len1, len2;
518
519 /* not counting the newline at the end of "searched" */
520 len1 = strlen(searched)-1;
521 len2 = strlen(searchfor);
522 if (len1 < len2)
523 return 0;
524 if (kdb_grep_leading && kdb_grep_trailing && len1 != len2)
525 return 0;
526 if (kdb_grep_leading) {
527 if (!strncmp(searched, searchfor, len2))
528 return 1;
529 } else if (kdb_grep_trailing) {
530 if (!strncmp(searched+len1-len2, searchfor, len2))
531 return 1;
532 } else {
533 firstchar = *searchfor;
534 cp = searched;
535 while ((cp = strchr(cp, firstchar))) {
536 if (!strncmp(cp, searchfor, len2))
537 return 1;
538 cp++;
539 }
540 }
541 return 0;
542}
543
544static void kdb_msg_write(const char *msg, int msg_len)
545{
546 struct console *c;
547 const char *cp;
548 int cookie;
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 /*
563 * The console_srcu_read_lock() only provides safe console list
564 * traversal. The use of the ->write() callback relies on all other
565 * CPUs being stopped at the moment and console drivers being able to
566 * handle reentrance when @oops_in_progress is set.
567 *
568 * There is no guarantee that every console driver can handle
569 * reentrance in this way; the developer deploying the debugger
570 * is responsible for ensuring that the console drivers they
571 * have selected handle reentrance appropriately.
572 */
573 cookie = console_srcu_read_lock();
574 for_each_console_srcu(c) {
575 if (!(console_srcu_read_flags(c) & CON_ENABLED))
576 continue;
577 if (c == dbg_io_ops->cons)
578 continue;
579 /*
580 * Set oops_in_progress to encourage the console drivers to
581 * disregard their internal spin locks: in the current calling
582 * context the risk of deadlock is a bigger problem than risks
583 * due to re-entering the console driver. We operate directly on
584 * oops_in_progress rather than using bust_spinlocks() because
585 * the calls bust_spinlocks() makes on exit are not appropriate
586 * for this calling context.
587 */
588 ++oops_in_progress;
589 c->write(c, msg, msg_len);
590 --oops_in_progress;
591 touch_nmi_watchdog();
592 }
593 console_srcu_read_unlock(cookie);
594}
595
596int vkdb_printf(enum kdb_msgsrc src, const char *fmt, va_list ap)
597{
598 int diag;
599 int linecount;
600 int colcount;
601 int logging, saved_loglevel = 0;
602 int retlen = 0;
603 int fnd, len;
604 int this_cpu, old_cpu;
605 char *cp, *cp2, *cphold = NULL, replaced_byte = ' ';
606 char *moreprompt = "more> ";
607 unsigned long flags;
608
609 /* Serialize kdb_printf if multiple cpus try to write at once.
610 * But if any cpu goes recursive in kdb, just print the output,
611 * even if it is interleaved with any other text.
612 */
613 local_irq_save(flags);
614 this_cpu = smp_processor_id();
615 for (;;) {
616 old_cpu = cmpxchg(&kdb_printf_cpu, -1, this_cpu);
617 if (old_cpu == -1 || old_cpu == this_cpu)
618 break;
619
620 cpu_relax();
621 }
622
623 diag = kdbgetintenv("LINES", &linecount);
624 if (diag || linecount <= 1)
625 linecount = 24;
626
627 diag = kdbgetintenv("COLUMNS", &colcount);
628 if (diag || colcount <= 1)
629 colcount = 80;
630
631 diag = kdbgetintenv("LOGGING", &logging);
632 if (diag)
633 logging = 0;
634
635 if (!kdb_grepping_flag || suspend_grep) {
636 /* normally, every vsnprintf starts a new buffer */
637 next_avail = kdb_buffer;
638 size_avail = sizeof(kdb_buffer);
639 }
640 vsnprintf(next_avail, size_avail, fmt, ap);
641
642 /*
643 * If kdb_parse() found that the command was cmd xxx | grep yyy
644 * then kdb_grepping_flag is set, and kdb_grep_string contains yyy
645 *
646 * Accumulate the print data up to a newline before searching it.
647 * (vsnprintf does null-terminate the string that it generates)
648 */
649
650 /* skip the search if prints are temporarily unconditional */
651 if (!suspend_grep && kdb_grepping_flag) {
652 cp = strchr(kdb_buffer, '\n');
653 if (!cp) {
654 /*
655 * Special cases that don't end with newlines
656 * but should be written without one:
657 * The "[nn]kdb> " prompt should
658 * appear at the front of the buffer.
659 *
660 * The "[nn]more " prompt should also be
661 * (MOREPROMPT -> moreprompt)
662 * written * but we print that ourselves,
663 * we set the suspend_grep flag to make
664 * it unconditional.
665 *
666 */
667 if (next_avail == kdb_buffer) {
668 /*
669 * these should occur after a newline,
670 * so they will be at the front of the
671 * buffer
672 */
673 cp2 = kdb_buffer;
674 len = strlen(kdb_prompt_str);
675 if (!strncmp(cp2, kdb_prompt_str, len)) {
676 /*
677 * We're about to start a new
678 * command, so we can go back
679 * to normal mode.
680 */
681 kdb_grepping_flag = 0;
682 goto kdb_printit;
683 }
684 }
685 /* no newline; don't search/write the buffer
686 until one is there */
687 len = strlen(kdb_buffer);
688 next_avail = kdb_buffer + len;
689 size_avail = sizeof(kdb_buffer) - len;
690 goto kdb_print_out;
691 }
692
693 /*
694 * The newline is present; print through it or discard
695 * it, depending on the results of the search.
696 */
697 cp++; /* to byte after the newline */
698 replaced_byte = *cp; /* remember what/where it was */
699 cphold = cp;
700 *cp = '\0'; /* end the string for our search */
701
702 /*
703 * We now have a newline at the end of the string
704 * Only continue with this output if it contains the
705 * search string.
706 */
707 fnd = kdb_search_string(kdb_buffer, kdb_grep_string);
708 if (!fnd) {
709 /*
710 * At this point the complete line at the start
711 * of kdb_buffer can be discarded, as it does
712 * not contain what the user is looking for.
713 * Shift the buffer left.
714 */
715 *cphold = replaced_byte;
716 strcpy(kdb_buffer, cphold);
717 len = strlen(kdb_buffer);
718 next_avail = kdb_buffer + len;
719 size_avail = sizeof(kdb_buffer) - len;
720 goto kdb_print_out;
721 }
722 if (kdb_grepping_flag >= KDB_GREPPING_FLAG_SEARCH) {
723 /*
724 * This was a interactive search (using '/' at more
725 * prompt) and it has completed. Replace the \0 with
726 * its original value to ensure multi-line strings
727 * are handled properly, and return to normal mode.
728 */
729 *cphold = replaced_byte;
730 kdb_grepping_flag = 0;
731 }
732 /*
733 * at this point the string is a full line and
734 * should be printed, up to the null.
735 */
736 }
737kdb_printit:
738
739 /*
740 * Write to all consoles.
741 */
742 retlen = strlen(kdb_buffer);
743 cp = (char *) printk_skip_headers(kdb_buffer);
744 if (!dbg_kdb_mode && kgdb_connected)
745 gdbstub_msg_write(cp, retlen - (cp - kdb_buffer));
746 else
747 kdb_msg_write(cp, retlen - (cp - kdb_buffer));
748
749 if (logging) {
750 saved_loglevel = console_loglevel;
751 console_loglevel = CONSOLE_LOGLEVEL_SILENT;
752 if (printk_get_level(kdb_buffer) || src == KDB_MSGSRC_PRINTK)
753 printk("%s", kdb_buffer);
754 else
755 pr_info("%s", kdb_buffer);
756 }
757
758 if (KDB_STATE(PAGER)) {
759 /*
760 * Check printed string to decide how to bump the
761 * kdb_nextline to control when the more prompt should
762 * show up.
763 */
764 int got = 0;
765 len = retlen;
766 while (len--) {
767 if (kdb_buffer[len] == '\n') {
768 kdb_nextline++;
769 got = 0;
770 } else if (kdb_buffer[len] == '\r') {
771 got = 0;
772 } else {
773 got++;
774 }
775 }
776 kdb_nextline += got / (colcount + 1);
777 }
778
779 /* check for having reached the LINES number of printed lines */
780 if (kdb_nextline >= linecount) {
781 char ch;
782
783 /* Watch out for recursion here. Any routine that calls
784 * kdb_printf will come back through here. And kdb_read
785 * uses kdb_printf to echo on serial consoles ...
786 */
787 kdb_nextline = 1; /* In case of recursion */
788
789 /*
790 * Pause until cr.
791 */
792 moreprompt = kdbgetenv("MOREPROMPT");
793 if (moreprompt == NULL)
794 moreprompt = "more> ";
795
796 kdb_input_flush();
797 kdb_msg_write(moreprompt, strlen(moreprompt));
798
799 if (logging)
800 printk("%s", moreprompt);
801
802 ch = kdb_getchar();
803 kdb_nextline = 1; /* Really set output line 1 */
804
805 /* empty and reset the buffer: */
806 kdb_buffer[0] = '\0';
807 next_avail = kdb_buffer;
808 size_avail = sizeof(kdb_buffer);
809 if ((ch == 'q') || (ch == 'Q')) {
810 /* user hit q or Q */
811 KDB_FLAG_SET(CMD_INTERRUPT); /* command interrupted */
812 KDB_STATE_CLEAR(PAGER);
813 /* end of command output; back to normal mode */
814 kdb_grepping_flag = 0;
815 kdb_printf("\n");
816 } else if (ch == ' ') {
817 kdb_printf("\r");
818 suspend_grep = 1; /* for this recursion */
819 } else if (ch == '\n' || ch == '\r') {
820 kdb_nextline = linecount - 1;
821 kdb_printf("\r");
822 suspend_grep = 1; /* for this recursion */
823 } else if (ch == '/' && !kdb_grepping_flag) {
824 kdb_printf("\r");
825 kdb_getstr(kdb_grep_string, KDB_GREP_STRLEN,
826 kdbgetenv("SEARCHPROMPT") ?: "search> ");
827 *strchrnul(kdb_grep_string, '\n') = '\0';
828 kdb_grepping_flag += KDB_GREPPING_FLAG_SEARCH;
829 suspend_grep = 1; /* for this recursion */
830 } else if (ch) {
831 /* user hit something unexpected */
832 suspend_grep = 1; /* for this recursion */
833 if (ch != '/')
834 kdb_printf(
835 "\nOnly 'q', 'Q' or '/' are processed at "
836 "more prompt, input ignored\n");
837 else
838 kdb_printf("\n'/' cannot be used during | "
839 "grep filtering, input ignored\n");
840 } else if (kdb_grepping_flag) {
841 /* user hit enter */
842 suspend_grep = 1; /* for this recursion */
843 kdb_printf("\n");
844 }
845 kdb_input_flush();
846 }
847
848 /*
849 * For grep searches, shift the printed string left.
850 * replaced_byte contains the character that was overwritten with
851 * the terminating null, and cphold points to the null.
852 * Then adjust the notion of available space in the buffer.
853 */
854 if (kdb_grepping_flag && !suspend_grep) {
855 *cphold = replaced_byte;
856 strcpy(kdb_buffer, cphold);
857 len = strlen(kdb_buffer);
858 next_avail = kdb_buffer + len;
859 size_avail = sizeof(kdb_buffer) - len;
860 }
861
862kdb_print_out:
863 suspend_grep = 0; /* end of what may have been a recursive call */
864 if (logging)
865 console_loglevel = saved_loglevel;
866 /* kdb_printf_cpu locked the code above. */
867 smp_store_release(&kdb_printf_cpu, old_cpu);
868 local_irq_restore(flags);
869 return retlen;
870}
871
872int kdb_printf(const char *fmt, ...)
873{
874 va_list ap;
875 int r;
876
877 va_start(ap, fmt);
878 r = vkdb_printf(KDB_MSGSRC_INTERNAL, fmt, ap);
879 va_end(ap);
880
881 return r;
882}
883EXPORT_SYMBOL_GPL(kdb_printf);
1/*
2 * Kernel Debugger Architecture Independent Console I/O handler
3 *
4 * This file is subject to the terms and conditions of the GNU General Public
5 * License. See the file "COPYING" in the main directory of this archive
6 * for more details.
7 *
8 * Copyright (c) 1999-2006 Silicon Graphics, Inc. All Rights Reserved.
9 * Copyright (c) 2009 Wind River Systems, Inc. All Rights Reserved.
10 */
11
12#include <linux/module.h>
13#include <linux/types.h>
14#include <linux/ctype.h>
15#include <linux/kernel.h>
16#include <linux/init.h>
17#include <linux/kdev_t.h>
18#include <linux/console.h>
19#include <linux/string.h>
20#include <linux/sched.h>
21#include <linux/smp.h>
22#include <linux/nmi.h>
23#include <linux/delay.h>
24#include <linux/kgdb.h>
25#include <linux/kdb.h>
26#include <linux/kallsyms.h>
27#include "kdb_private.h"
28
29#define CMD_BUFLEN 256
30char kdb_prompt_str[CMD_BUFLEN];
31
32int kdb_trap_printk;
33int kdb_printf_cpu = -1;
34
35static int kgdb_transition_check(char *buffer)
36{
37 if (buffer[0] != '+' && buffer[0] != '$') {
38 KDB_STATE_SET(KGDB_TRANS);
39 kdb_printf("%s", buffer);
40 } else {
41 int slen = strlen(buffer);
42 if (slen > 3 && buffer[slen - 3] == '#') {
43 kdb_gdb_state_pass(buffer);
44 strcpy(buffer, "kgdb");
45 KDB_STATE_SET(DOING_KGDB);
46 return 1;
47 }
48 }
49 return 0;
50}
51
52/**
53 * kdb_handle_escape() - validity check on an accumulated escape sequence.
54 * @buf: Accumulated escape characters to be examined. Note that buf
55 * is not a string, it is an array of characters and need not be
56 * nil terminated.
57 * @sz: Number of accumulated escape characters.
58 *
59 * Return: -1 if the escape sequence is unwanted, 0 if it is incomplete,
60 * otherwise it returns a mapped key value to pass to the upper layers.
61 */
62static int kdb_handle_escape(char *buf, size_t sz)
63{
64 char *lastkey = buf + sz - 1;
65
66 switch (sz) {
67 case 1:
68 if (*lastkey == '\e')
69 return 0;
70 break;
71
72 case 2: /* \e<something> */
73 if (*lastkey == '[')
74 return 0;
75 break;
76
77 case 3:
78 switch (*lastkey) {
79 case 'A': /* \e[A, up arrow */
80 return 16;
81 case 'B': /* \e[B, down arrow */
82 return 14;
83 case 'C': /* \e[C, right arrow */
84 return 6;
85 case 'D': /* \e[D, left arrow */
86 return 2;
87 case '1': /* \e[<1,3,4>], may be home, del, end */
88 case '3':
89 case '4':
90 return 0;
91 }
92 break;
93
94 case 4:
95 if (*lastkey == '~') {
96 switch (buf[2]) {
97 case '1': /* \e[1~, home */
98 return 1;
99 case '3': /* \e[3~, del */
100 return 4;
101 case '4': /* \e[4~, end */
102 return 5;
103 }
104 }
105 break;
106 }
107
108 return -1;
109}
110
111/**
112 * kdb_getchar() - Read a single character from a kdb console (or consoles).
113 *
114 * Other than polling the various consoles that are currently enabled,
115 * most of the work done in this function is dealing with escape sequences.
116 *
117 * An escape key could be the start of a vt100 control sequence such as \e[D
118 * (left arrow) or it could be a character in its own right. The standard
119 * method for detecting the difference is to wait for 2 seconds to see if there
120 * are any other characters. kdb is complicated by the lack of a timer service
121 * (interrupts are off), by multiple input sources. Escape sequence processing
122 * has to be done as states in the polling loop.
123 *
124 * Return: The key pressed or a control code derived from an escape sequence.
125 */
126char kdb_getchar(void)
127{
128#define ESCAPE_UDELAY 1000
129#define ESCAPE_DELAY (2*1000000/ESCAPE_UDELAY) /* 2 seconds worth of udelays */
130 char buf[4]; /* longest vt100 escape sequence is 4 bytes */
131 char *pbuf = buf;
132 int escape_delay = 0;
133 get_char_func *f, *f_prev = NULL;
134 int key;
135
136 for (f = &kdb_poll_funcs[0]; ; ++f) {
137 if (*f == NULL) {
138 /* Reset NMI watchdog once per poll loop */
139 touch_nmi_watchdog();
140 f = &kdb_poll_funcs[0];
141 }
142
143 key = (*f)();
144 if (key == -1) {
145 if (escape_delay) {
146 udelay(ESCAPE_UDELAY);
147 if (--escape_delay == 0)
148 return '\e';
149 }
150 continue;
151 }
152
153 /*
154 * When the first character is received (or we get a change
155 * input source) we set ourselves up to handle an escape
156 * sequences (just in case).
157 */
158 if (f_prev != f) {
159 f_prev = f;
160 pbuf = buf;
161 escape_delay = ESCAPE_DELAY;
162 }
163
164 *pbuf++ = key;
165 key = kdb_handle_escape(buf, pbuf - buf);
166 if (key < 0) /* no escape sequence; return best character */
167 return buf[pbuf - buf == 2 ? 1 : 0];
168 if (key > 0)
169 return key;
170 }
171
172 unreachable();
173}
174
175/*
176 * kdb_read
177 *
178 * This function reads a string of characters, terminated by
179 * a newline, or by reaching the end of the supplied buffer,
180 * from the current kernel debugger console device.
181 * Parameters:
182 * buffer - Address of character buffer to receive input characters.
183 * bufsize - size, in bytes, of the character buffer
184 * Returns:
185 * Returns a pointer to the buffer containing the received
186 * character string. This string will be terminated by a
187 * newline character.
188 * Locking:
189 * No locks are required to be held upon entry to this
190 * function. It is not reentrant - it relies on the fact
191 * that while kdb is running on only one "master debug" cpu.
192 * Remarks:
193 * The buffer size must be >= 2.
194 */
195
196static char *kdb_read(char *buffer, size_t bufsize)
197{
198 char *cp = buffer;
199 char *bufend = buffer+bufsize-2; /* Reserve space for newline
200 * and null byte */
201 char *lastchar;
202 char *p_tmp;
203 char tmp;
204 static char tmpbuffer[CMD_BUFLEN];
205 int len = strlen(buffer);
206 int len_tmp;
207 int tab = 0;
208 int count;
209 int i;
210 int diag, dtab_count;
211 int key, buf_size, ret;
212
213
214 diag = kdbgetintenv("DTABCOUNT", &dtab_count);
215 if (diag)
216 dtab_count = 30;
217
218 if (len > 0) {
219 cp += len;
220 if (*(buffer+len-1) == '\n')
221 cp--;
222 }
223
224 lastchar = cp;
225 *cp = '\0';
226 kdb_printf("%s", buffer);
227poll_again:
228 key = kdb_getchar();
229 if (key != 9)
230 tab = 0;
231 switch (key) {
232 case 8: /* backspace */
233 if (cp > buffer) {
234 if (cp < lastchar) {
235 memcpy(tmpbuffer, cp, lastchar - cp);
236 memcpy(cp-1, tmpbuffer, lastchar - cp);
237 }
238 *(--lastchar) = '\0';
239 --cp;
240 kdb_printf("\b%s \r", cp);
241 tmp = *cp;
242 *cp = '\0';
243 kdb_printf(kdb_prompt_str);
244 kdb_printf("%s", buffer);
245 *cp = tmp;
246 }
247 break;
248 case 13: /* enter */
249 *lastchar++ = '\n';
250 *lastchar++ = '\0';
251 if (!KDB_STATE(KGDB_TRANS)) {
252 KDB_STATE_SET(KGDB_TRANS);
253 kdb_printf("%s", buffer);
254 }
255 kdb_printf("\n");
256 return buffer;
257 case 4: /* Del */
258 if (cp < lastchar) {
259 memcpy(tmpbuffer, cp+1, lastchar - cp - 1);
260 memcpy(cp, tmpbuffer, lastchar - cp - 1);
261 *(--lastchar) = '\0';
262 kdb_printf("%s \r", cp);
263 tmp = *cp;
264 *cp = '\0';
265 kdb_printf(kdb_prompt_str);
266 kdb_printf("%s", buffer);
267 *cp = tmp;
268 }
269 break;
270 case 1: /* Home */
271 if (cp > buffer) {
272 kdb_printf("\r");
273 kdb_printf(kdb_prompt_str);
274 cp = buffer;
275 }
276 break;
277 case 5: /* End */
278 if (cp < lastchar) {
279 kdb_printf("%s", cp);
280 cp = lastchar;
281 }
282 break;
283 case 2: /* Left */
284 if (cp > buffer) {
285 kdb_printf("\b");
286 --cp;
287 }
288 break;
289 case 14: /* Down */
290 memset(tmpbuffer, ' ',
291 strlen(kdb_prompt_str) + (lastchar-buffer));
292 *(tmpbuffer+strlen(kdb_prompt_str) +
293 (lastchar-buffer)) = '\0';
294 kdb_printf("\r%s\r", tmpbuffer);
295 *lastchar = (char)key;
296 *(lastchar+1) = '\0';
297 return lastchar;
298 case 6: /* Right */
299 if (cp < lastchar) {
300 kdb_printf("%c", *cp);
301 ++cp;
302 }
303 break;
304 case 16: /* Up */
305 memset(tmpbuffer, ' ',
306 strlen(kdb_prompt_str) + (lastchar-buffer));
307 *(tmpbuffer+strlen(kdb_prompt_str) +
308 (lastchar-buffer)) = '\0';
309 kdb_printf("\r%s\r", tmpbuffer);
310 *lastchar = (char)key;
311 *(lastchar+1) = '\0';
312 return lastchar;
313 case 9: /* Tab */
314 if (tab < 2)
315 ++tab;
316 p_tmp = buffer;
317 while (*p_tmp == ' ')
318 p_tmp++;
319 if (p_tmp > cp)
320 break;
321 memcpy(tmpbuffer, p_tmp, cp-p_tmp);
322 *(tmpbuffer + (cp-p_tmp)) = '\0';
323 p_tmp = strrchr(tmpbuffer, ' ');
324 if (p_tmp)
325 ++p_tmp;
326 else
327 p_tmp = tmpbuffer;
328 len = strlen(p_tmp);
329 buf_size = sizeof(tmpbuffer) - (p_tmp - tmpbuffer);
330 count = kallsyms_symbol_complete(p_tmp, buf_size);
331 if (tab == 2 && count > 0) {
332 kdb_printf("\n%d symbols are found.", count);
333 if (count > dtab_count) {
334 count = dtab_count;
335 kdb_printf(" But only first %d symbols will"
336 " be printed.\nYou can change the"
337 " environment variable DTABCOUNT.",
338 count);
339 }
340 kdb_printf("\n");
341 for (i = 0; i < count; i++) {
342 ret = kallsyms_symbol_next(p_tmp, i, buf_size);
343 if (WARN_ON(!ret))
344 break;
345 if (ret != -E2BIG)
346 kdb_printf("%s ", p_tmp);
347 else
348 kdb_printf("%s... ", p_tmp);
349 *(p_tmp + len) = '\0';
350 }
351 if (i >= dtab_count)
352 kdb_printf("...");
353 kdb_printf("\n");
354 kdb_printf(kdb_prompt_str);
355 kdb_printf("%s", buffer);
356 } else if (tab != 2 && count > 0) {
357 len_tmp = strlen(p_tmp);
358 strncpy(p_tmp+len_tmp, cp, lastchar-cp+1);
359 len_tmp = strlen(p_tmp);
360 strncpy(cp, p_tmp+len, len_tmp-len + 1);
361 len = len_tmp - len;
362 kdb_printf("%s", cp);
363 cp += len;
364 lastchar += len;
365 }
366 kdb_nextline = 1; /* reset output line number */
367 break;
368 default:
369 if (key >= 32 && lastchar < bufend) {
370 if (cp < lastchar) {
371 memcpy(tmpbuffer, cp, lastchar - cp);
372 memcpy(cp+1, tmpbuffer, lastchar - cp);
373 *++lastchar = '\0';
374 *cp = key;
375 kdb_printf("%s\r", cp);
376 ++cp;
377 tmp = *cp;
378 *cp = '\0';
379 kdb_printf(kdb_prompt_str);
380 kdb_printf("%s", buffer);
381 *cp = tmp;
382 } else {
383 *++lastchar = '\0';
384 *cp++ = key;
385 /* The kgdb transition check will hide
386 * printed characters if we think that
387 * kgdb is connecting, until the check
388 * fails */
389 if (!KDB_STATE(KGDB_TRANS)) {
390 if (kgdb_transition_check(buffer))
391 return buffer;
392 } else {
393 kdb_printf("%c", key);
394 }
395 }
396 /* Special escape to kgdb */
397 if (lastchar - buffer >= 5 &&
398 strcmp(lastchar - 5, "$?#3f") == 0) {
399 kdb_gdb_state_pass(lastchar - 5);
400 strcpy(buffer, "kgdb");
401 KDB_STATE_SET(DOING_KGDB);
402 return buffer;
403 }
404 if (lastchar - buffer >= 11 &&
405 strcmp(lastchar - 11, "$qSupported") == 0) {
406 kdb_gdb_state_pass(lastchar - 11);
407 strcpy(buffer, "kgdb");
408 KDB_STATE_SET(DOING_KGDB);
409 return buffer;
410 }
411 }
412 break;
413 }
414 goto poll_again;
415}
416
417/*
418 * kdb_getstr
419 *
420 * Print the prompt string and read a command from the
421 * input device.
422 *
423 * Parameters:
424 * buffer Address of buffer to receive command
425 * bufsize Size of buffer in bytes
426 * prompt Pointer to string to use as prompt string
427 * Returns:
428 * Pointer to command buffer.
429 * Locking:
430 * None.
431 * Remarks:
432 * For SMP kernels, the processor number will be
433 * substituted for %d, %x or %o in the prompt.
434 */
435
436char *kdb_getstr(char *buffer, size_t bufsize, const char *prompt)
437{
438 if (prompt && kdb_prompt_str != prompt)
439 strscpy(kdb_prompt_str, prompt, CMD_BUFLEN);
440 kdb_printf(kdb_prompt_str);
441 kdb_nextline = 1; /* Prompt and input resets line number */
442 return kdb_read(buffer, bufsize);
443}
444
445/*
446 * kdb_input_flush
447 *
448 * Get rid of any buffered console input.
449 *
450 * Parameters:
451 * none
452 * Returns:
453 * nothing
454 * Locking:
455 * none
456 * Remarks:
457 * Call this function whenever you want to flush input. If there is any
458 * outstanding input, it ignores all characters until there has been no
459 * data for approximately 1ms.
460 */
461
462static void kdb_input_flush(void)
463{
464 get_char_func *f;
465 int res;
466 int flush_delay = 1;
467 while (flush_delay) {
468 flush_delay--;
469empty:
470 touch_nmi_watchdog();
471 for (f = &kdb_poll_funcs[0]; *f; ++f) {
472 res = (*f)();
473 if (res != -1) {
474 flush_delay = 1;
475 goto empty;
476 }
477 }
478 if (flush_delay)
479 mdelay(1);
480 }
481}
482
483/*
484 * kdb_printf
485 *
486 * Print a string to the output device(s).
487 *
488 * Parameters:
489 * printf-like format and optional args.
490 * Returns:
491 * 0
492 * Locking:
493 * None.
494 * Remarks:
495 * use 'kdbcons->write()' to avoid polluting 'log_buf' with
496 * kdb output.
497 *
498 * If the user is doing a cmd args | grep srch
499 * then kdb_grepping_flag is set.
500 * In that case we need to accumulate full lines (ending in \n) before
501 * searching for the pattern.
502 */
503
504static char kdb_buffer[256]; /* A bit too big to go on stack */
505static char *next_avail = kdb_buffer;
506static int size_avail;
507static int suspend_grep;
508
509/*
510 * search arg1 to see if it contains arg2
511 * (kdmain.c provides flags for ^pat and pat$)
512 *
513 * return 1 for found, 0 for not found
514 */
515static int kdb_search_string(char *searched, char *searchfor)
516{
517 char firstchar, *cp;
518 int len1, len2;
519
520 /* not counting the newline at the end of "searched" */
521 len1 = strlen(searched)-1;
522 len2 = strlen(searchfor);
523 if (len1 < len2)
524 return 0;
525 if (kdb_grep_leading && kdb_grep_trailing && len1 != len2)
526 return 0;
527 if (kdb_grep_leading) {
528 if (!strncmp(searched, searchfor, len2))
529 return 1;
530 } else if (kdb_grep_trailing) {
531 if (!strncmp(searched+len1-len2, searchfor, len2))
532 return 1;
533 } else {
534 firstchar = *searchfor;
535 cp = searched;
536 while ((cp = strchr(cp, firstchar))) {
537 if (!strncmp(cp, searchfor, len2))
538 return 1;
539 cp++;
540 }
541 }
542 return 0;
543}
544
545static void kdb_msg_write(const char *msg, int msg_len)
546{
547 struct console *c;
548
549 if (msg_len == 0)
550 return;
551
552 if (dbg_io_ops) {
553 const char *cp = msg;
554 int len = msg_len;
555
556 while (len--) {
557 dbg_io_ops->write_char(*cp);
558 cp++;
559 }
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. Clear the flag.
713 */
714 kdb_grepping_flag = 0;
715 /*
716 * at this point the string is a full line and
717 * should be printed, up to the null.
718 */
719 }
720kdb_printit:
721
722 /*
723 * Write to all consoles.
724 */
725 retlen = strlen(kdb_buffer);
726 cp = (char *) printk_skip_headers(kdb_buffer);
727 if (!dbg_kdb_mode && kgdb_connected)
728 gdbstub_msg_write(cp, retlen - (cp - kdb_buffer));
729 else
730 kdb_msg_write(cp, retlen - (cp - kdb_buffer));
731
732 if (logging) {
733 saved_loglevel = console_loglevel;
734 console_loglevel = CONSOLE_LOGLEVEL_SILENT;
735 if (printk_get_level(kdb_buffer) || src == KDB_MSGSRC_PRINTK)
736 printk("%s", kdb_buffer);
737 else
738 pr_info("%s", kdb_buffer);
739 }
740
741 if (KDB_STATE(PAGER)) {
742 /*
743 * Check printed string to decide how to bump the
744 * kdb_nextline to control when the more prompt should
745 * show up.
746 */
747 int got = 0;
748 len = retlen;
749 while (len--) {
750 if (kdb_buffer[len] == '\n') {
751 kdb_nextline++;
752 got = 0;
753 } else if (kdb_buffer[len] == '\r') {
754 got = 0;
755 } else {
756 got++;
757 }
758 }
759 kdb_nextline += got / (colcount + 1);
760 }
761
762 /* check for having reached the LINES number of printed lines */
763 if (kdb_nextline >= linecount) {
764 char ch;
765
766 /* Watch out for recursion here. Any routine that calls
767 * kdb_printf will come back through here. And kdb_read
768 * uses kdb_printf to echo on serial consoles ...
769 */
770 kdb_nextline = 1; /* In case of recursion */
771
772 /*
773 * Pause until cr.
774 */
775 moreprompt = kdbgetenv("MOREPROMPT");
776 if (moreprompt == NULL)
777 moreprompt = "more> ";
778
779 kdb_input_flush();
780 kdb_msg_write(moreprompt, strlen(moreprompt));
781
782 if (logging)
783 printk("%s", moreprompt);
784
785 ch = kdb_getchar();
786 kdb_nextline = 1; /* Really set output line 1 */
787
788 /* empty and reset the buffer: */
789 kdb_buffer[0] = '\0';
790 next_avail = kdb_buffer;
791 size_avail = sizeof(kdb_buffer);
792 if ((ch == 'q') || (ch == 'Q')) {
793 /* user hit q or Q */
794 KDB_FLAG_SET(CMD_INTERRUPT); /* command interrupted */
795 KDB_STATE_CLEAR(PAGER);
796 /* end of command output; back to normal mode */
797 kdb_grepping_flag = 0;
798 kdb_printf("\n");
799 } else if (ch == ' ') {
800 kdb_printf("\r");
801 suspend_grep = 1; /* for this recursion */
802 } else if (ch == '\n' || ch == '\r') {
803 kdb_nextline = linecount - 1;
804 kdb_printf("\r");
805 suspend_grep = 1; /* for this recursion */
806 } else if (ch == '/' && !kdb_grepping_flag) {
807 kdb_printf("\r");
808 kdb_getstr(kdb_grep_string, KDB_GREP_STRLEN,
809 kdbgetenv("SEARCHPROMPT") ?: "search> ");
810 *strchrnul(kdb_grep_string, '\n') = '\0';
811 kdb_grepping_flag += KDB_GREPPING_FLAG_SEARCH;
812 suspend_grep = 1; /* for this recursion */
813 } else if (ch) {
814 /* user hit something unexpected */
815 suspend_grep = 1; /* for this recursion */
816 if (ch != '/')
817 kdb_printf(
818 "\nOnly 'q', 'Q' or '/' are processed at "
819 "more prompt, input ignored\n");
820 else
821 kdb_printf("\n'/' cannot be used during | "
822 "grep filtering, input ignored\n");
823 } else if (kdb_grepping_flag) {
824 /* user hit enter */
825 suspend_grep = 1; /* for this recursion */
826 kdb_printf("\n");
827 }
828 kdb_input_flush();
829 }
830
831 /*
832 * For grep searches, shift the printed string left.
833 * replaced_byte contains the character that was overwritten with
834 * the terminating null, and cphold points to the null.
835 * Then adjust the notion of available space in the buffer.
836 */
837 if (kdb_grepping_flag && !suspend_grep) {
838 *cphold = replaced_byte;
839 strcpy(kdb_buffer, cphold);
840 len = strlen(kdb_buffer);
841 next_avail = kdb_buffer + len;
842 size_avail = sizeof(kdb_buffer) - len;
843 }
844
845kdb_print_out:
846 suspend_grep = 0; /* end of what may have been a recursive call */
847 if (logging)
848 console_loglevel = saved_loglevel;
849 /* kdb_printf_cpu locked the code above. */
850 smp_store_release(&kdb_printf_cpu, old_cpu);
851 local_irq_restore(flags);
852 return retlen;
853}
854
855int kdb_printf(const char *fmt, ...)
856{
857 va_list ap;
858 int r;
859
860 va_start(ap, fmt);
861 r = vkdb_printf(KDB_MSGSRC_INTERNAL, fmt, ap);
862 va_end(ap);
863
864 return r;
865}
866EXPORT_SYMBOL_GPL(kdb_printf);