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
29 char kdb_prompt_str[CMD_BUFLEN];
30
31 int kdb_trap_printk;
32 int kdb_printf_cpu = -1;
33
kgdb_transition_check(char * buffer)34 static 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 */
kdb_handle_escape(char * buf,size_t sz)61 static 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 */
kdb_getchar(void)125 char 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 */
kdb_position_cursor(char * prompt,char * buffer,char * cp)207 static void kdb_position_cursor(char *prompt, char *buffer, char *cp)
208 {
209 kdb_printf("\r%s", kdb_prompt_str);
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
kdb_read(char * buffer,size_t bufsize)235 static 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 static char tmpbuffer[CMD_BUFLEN];
243 int len = strlen(buffer);
244 int len_tmp;
245 int tab = 0;
246 int count;
247 int i;
248 int diag, dtab_count;
249 int key, buf_size, ret;
250
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);
265 poll_again:
266 key = kdb_getchar();
267 if (key != 9)
268 tab = 0;
269 switch (key) {
270 case 8: /* backspace */
271 if (cp > buffer) {
272 if (cp < lastchar) {
273 memcpy(tmpbuffer, cp, lastchar - cp);
274 memcpy(cp-1, tmpbuffer, lastchar - cp);
275 }
276 *(--lastchar) = '\0';
277 --cp;
278 kdb_printf("\b%s ", cp);
279 kdb_position_cursor(kdb_prompt_str, buffer, cp);
280 }
281 break;
282 case 10: /* linefeed */
283 case 13: /* carriage return */
284 *lastchar++ = '\n';
285 *lastchar++ = '\0';
286 if (!KDB_STATE(KGDB_TRANS)) {
287 KDB_STATE_SET(KGDB_TRANS);
288 kdb_printf("%s", buffer);
289 }
290 kdb_printf("\n");
291 return buffer;
292 case 4: /* Del */
293 if (cp < lastchar) {
294 memcpy(tmpbuffer, cp+1, lastchar - cp - 1);
295 memcpy(cp, tmpbuffer, lastchar - cp - 1);
296 *(--lastchar) = '\0';
297 kdb_printf("%s ", cp);
298 kdb_position_cursor(kdb_prompt_str, buffer, cp);
299 }
300 break;
301 case 1: /* Home */
302 if (cp > buffer) {
303 cp = buffer;
304 kdb_position_cursor(kdb_prompt_str, buffer, cp);
305 }
306 break;
307 case 5: /* End */
308 if (cp < lastchar) {
309 kdb_printf("%s", cp);
310 cp = lastchar;
311 }
312 break;
313 case 2: /* Left */
314 if (cp > buffer) {
315 kdb_printf("\b");
316 --cp;
317 }
318 break;
319 case 14: /* Down */
320 case 16: /* Up */
321 kdb_printf("\r%*c\r",
322 (int)(strlen(kdb_prompt_str) + (lastchar - buffer)),
323 ' ');
324 *lastchar = (char)key;
325 *(lastchar+1) = '\0';
326 return lastchar;
327 case 6: /* Right */
328 if (cp < lastchar) {
329 kdb_printf("%c", *cp);
330 ++cp;
331 }
332 break;
333 case 9: /* Tab */
334 if (tab < 2)
335 ++tab;
336 p_tmp = buffer;
337 while (*p_tmp == ' ')
338 p_tmp++;
339 if (p_tmp > cp)
340 break;
341 memcpy(tmpbuffer, p_tmp, cp-p_tmp);
342 *(tmpbuffer + (cp-p_tmp)) = '\0';
343 p_tmp = strrchr(tmpbuffer, ' ');
344 if (p_tmp)
345 ++p_tmp;
346 else
347 p_tmp = tmpbuffer;
348 len = strlen(p_tmp);
349 buf_size = sizeof(tmpbuffer) - (p_tmp - tmpbuffer);
350 count = kallsyms_symbol_complete(p_tmp, buf_size);
351 if (tab == 2 && count > 0) {
352 kdb_printf("\n%d symbols are found.", count);
353 if (count > dtab_count) {
354 count = dtab_count;
355 kdb_printf(" But only first %d symbols will"
356 " be printed.\nYou can change the"
357 " environment variable DTABCOUNT.",
358 count);
359 }
360 kdb_printf("\n");
361 for (i = 0; i < count; i++) {
362 ret = kallsyms_symbol_next(p_tmp, i, buf_size);
363 if (WARN_ON(!ret))
364 break;
365 if (ret != -E2BIG)
366 kdb_printf("%s ", p_tmp);
367 else
368 kdb_printf("%s... ", p_tmp);
369 *(p_tmp + len) = '\0';
370 }
371 if (i >= dtab_count)
372 kdb_printf("...");
373 kdb_printf("\n");
374 kdb_printf(kdb_prompt_str);
375 kdb_printf("%s", buffer);
376 if (cp != lastchar)
377 kdb_position_cursor(kdb_prompt_str, buffer, cp);
378 } else if (tab != 2 && count > 0) {
379 /* How many new characters do we want from tmpbuffer? */
380 len_tmp = strlen(p_tmp) - len;
381 if (lastchar + len_tmp >= bufend)
382 len_tmp = bufend - lastchar;
383
384 if (len_tmp) {
385 /* + 1 ensures the '\0' is memmove'd */
386 memmove(cp+len_tmp, cp, (lastchar-cp) + 1);
387 memcpy(cp, p_tmp+len, len_tmp);
388 kdb_printf("%s", cp);
389 cp += len_tmp;
390 lastchar += len_tmp;
391 if (cp != lastchar)
392 kdb_position_cursor(kdb_prompt_str,
393 buffer, cp);
394 }
395 }
396 kdb_nextline = 1; /* reset output line number */
397 break;
398 default:
399 if (key >= 32 && lastchar < bufend) {
400 if (cp < lastchar) {
401 memcpy(tmpbuffer, cp, lastchar - cp);
402 memcpy(cp+1, tmpbuffer, lastchar - cp);
403 *++lastchar = '\0';
404 *cp = key;
405 kdb_printf("%s", cp);
406 ++cp;
407 kdb_position_cursor(kdb_prompt_str, buffer, cp);
408 } else {
409 *++lastchar = '\0';
410 *cp++ = key;
411 /* The kgdb transition check will hide
412 * printed characters if we think that
413 * kgdb is connecting, until the check
414 * fails */
415 if (!KDB_STATE(KGDB_TRANS)) {
416 if (kgdb_transition_check(buffer))
417 return buffer;
418 } else {
419 kdb_printf("%c", key);
420 }
421 }
422 /* Special escape to kgdb */
423 if (lastchar - buffer >= 5 &&
424 strcmp(lastchar - 5, "$?#3f") == 0) {
425 kdb_gdb_state_pass(lastchar - 5);
426 strcpy(buffer, "kgdb");
427 KDB_STATE_SET(DOING_KGDB);
428 return buffer;
429 }
430 if (lastchar - buffer >= 11 &&
431 strcmp(lastchar - 11, "$qSupported") == 0) {
432 kdb_gdb_state_pass(lastchar - 11);
433 strcpy(buffer, "kgdb");
434 KDB_STATE_SET(DOING_KGDB);
435 return buffer;
436 }
437 }
438 break;
439 }
440 goto poll_again;
441 }
442
443 /*
444 * kdb_getstr
445 *
446 * Print the prompt string and read a command from the
447 * input device.
448 *
449 * Parameters:
450 * buffer Address of buffer to receive command
451 * bufsize Size of buffer in bytes
452 * prompt Pointer to string to use as prompt string
453 * Returns:
454 * Pointer to command buffer.
455 * Locking:
456 * None.
457 * Remarks:
458 * For SMP kernels, the processor number will be
459 * substituted for %d, %x or %o in the prompt.
460 */
461
kdb_getstr(char * buffer,size_t bufsize,const char * prompt)462 char *kdb_getstr(char *buffer, size_t bufsize, const char *prompt)
463 {
464 if (prompt && kdb_prompt_str != prompt)
465 strscpy(kdb_prompt_str, prompt, CMD_BUFLEN);
466 kdb_printf(kdb_prompt_str);
467 kdb_nextline = 1; /* Prompt and input resets line number */
468 return kdb_read(buffer, bufsize);
469 }
470
471 /*
472 * kdb_input_flush
473 *
474 * Get rid of any buffered console input.
475 *
476 * Parameters:
477 * none
478 * Returns:
479 * nothing
480 * Locking:
481 * none
482 * Remarks:
483 * Call this function whenever you want to flush input. If there is any
484 * outstanding input, it ignores all characters until there has been no
485 * data for approximately 1ms.
486 */
487
kdb_input_flush(void)488 static void kdb_input_flush(void)
489 {
490 get_char_func *f;
491 int res;
492 int flush_delay = 1;
493 while (flush_delay) {
494 flush_delay--;
495 empty:
496 touch_nmi_watchdog();
497 for (f = &kdb_poll_funcs[0]; *f; ++f) {
498 res = (*f)();
499 if (res != -1) {
500 flush_delay = 1;
501 goto empty;
502 }
503 }
504 if (flush_delay)
505 mdelay(1);
506 }
507 }
508
509 /*
510 * kdb_printf
511 *
512 * Print a string to the output device(s).
513 *
514 * Parameters:
515 * printf-like format and optional args.
516 * Returns:
517 * 0
518 * Locking:
519 * None.
520 * Remarks:
521 * use 'kdbcons->write()' to avoid polluting 'log_buf' with
522 * kdb output.
523 *
524 * If the user is doing a cmd args | grep srch
525 * then kdb_grepping_flag is set.
526 * In that case we need to accumulate full lines (ending in \n) before
527 * searching for the pattern.
528 */
529
530 static char kdb_buffer[256]; /* A bit too big to go on stack */
531 static char *next_avail = kdb_buffer;
532 static int size_avail;
533 static int suspend_grep;
534
535 /*
536 * search arg1 to see if it contains arg2
537 * (kdmain.c provides flags for ^pat and pat$)
538 *
539 * return 1 for found, 0 for not found
540 */
kdb_search_string(char * searched,char * searchfor)541 static int kdb_search_string(char *searched, char *searchfor)
542 {
543 char firstchar, *cp;
544 int len1, len2;
545
546 /* not counting the newline at the end of "searched" */
547 len1 = strlen(searched)-1;
548 len2 = strlen(searchfor);
549 if (len1 < len2)
550 return 0;
551 if (kdb_grep_leading && kdb_grep_trailing && len1 != len2)
552 return 0;
553 if (kdb_grep_leading) {
554 if (!strncmp(searched, searchfor, len2))
555 return 1;
556 } else if (kdb_grep_trailing) {
557 if (!strncmp(searched+len1-len2, searchfor, len2))
558 return 1;
559 } else {
560 firstchar = *searchfor;
561 cp = searched;
562 while ((cp = strchr(cp, firstchar))) {
563 if (!strncmp(cp, searchfor, len2))
564 return 1;
565 cp++;
566 }
567 }
568 return 0;
569 }
570
kdb_msg_write(const char * msg,int msg_len)571 static void kdb_msg_write(const char *msg, int msg_len)
572 {
573 struct console *c;
574 const char *cp;
575 int cookie;
576 int len;
577
578 if (msg_len == 0)
579 return;
580
581 cp = msg;
582 len = msg_len;
583
584 while (len--) {
585 dbg_io_ops->write_char(*cp);
586 cp++;
587 }
588
589 /*
590 * The console_srcu_read_lock() only provides safe console list
591 * traversal. The use of the ->write() callback relies on all other
592 * CPUs being stopped at the moment and console drivers being able to
593 * handle reentrance when @oops_in_progress is set.
594 *
595 * There is no guarantee that every console driver can handle
596 * reentrance in this way; the developer deploying the debugger
597 * is responsible for ensuring that the console drivers they
598 * have selected handle reentrance appropriately.
599 */
600 cookie = console_srcu_read_lock();
601 for_each_console_srcu(c) {
602 if (!(console_srcu_read_flags(c) & CON_ENABLED))
603 continue;
604 if (c == dbg_io_ops->cons)
605 continue;
606 if (!c->write)
607 continue;
608 /*
609 * Set oops_in_progress to encourage the console drivers to
610 * disregard their internal spin locks: in the current calling
611 * context the risk of deadlock is a bigger problem than risks
612 * due to re-entering the console driver. We operate directly on
613 * oops_in_progress rather than using bust_spinlocks() because
614 * the calls bust_spinlocks() makes on exit are not appropriate
615 * for this calling context.
616 */
617 ++oops_in_progress;
618 c->write(c, msg, msg_len);
619 --oops_in_progress;
620 touch_nmi_watchdog();
621 }
622 console_srcu_read_unlock(cookie);
623 }
624
vkdb_printf(enum kdb_msgsrc src,const char * fmt,va_list ap)625 int vkdb_printf(enum kdb_msgsrc src, const char *fmt, va_list ap)
626 {
627 int diag;
628 int linecount;
629 int colcount;
630 int logging, saved_loglevel = 0;
631 int retlen = 0;
632 int fnd, len;
633 int this_cpu, old_cpu;
634 char *cp, *cp2, *cphold = NULL, replaced_byte = ' ';
635 char *moreprompt = "more> ";
636 unsigned long flags;
637
638 /* Serialize kdb_printf if multiple cpus try to write at once.
639 * But if any cpu goes recursive in kdb, just print the output,
640 * even if it is interleaved with any other text.
641 */
642 local_irq_save(flags);
643 this_cpu = smp_processor_id();
644 for (;;) {
645 old_cpu = cmpxchg(&kdb_printf_cpu, -1, this_cpu);
646 if (old_cpu == -1 || old_cpu == this_cpu)
647 break;
648
649 cpu_relax();
650 }
651
652 diag = kdbgetintenv("LINES", &linecount);
653 if (diag || linecount <= 1)
654 linecount = 24;
655
656 diag = kdbgetintenv("COLUMNS", &colcount);
657 if (diag || colcount <= 1)
658 colcount = 80;
659
660 diag = kdbgetintenv("LOGGING", &logging);
661 if (diag)
662 logging = 0;
663
664 if (!kdb_grepping_flag || suspend_grep) {
665 /* normally, every vsnprintf starts a new buffer */
666 next_avail = kdb_buffer;
667 size_avail = sizeof(kdb_buffer);
668 }
669 vsnprintf(next_avail, size_avail, fmt, ap);
670
671 /*
672 * If kdb_parse() found that the command was cmd xxx | grep yyy
673 * then kdb_grepping_flag is set, and kdb_grep_string contains yyy
674 *
675 * Accumulate the print data up to a newline before searching it.
676 * (vsnprintf does null-terminate the string that it generates)
677 */
678
679 /* skip the search if prints are temporarily unconditional */
680 if (!suspend_grep && kdb_grepping_flag) {
681 cp = strchr(kdb_buffer, '\n');
682 if (!cp) {
683 /*
684 * Special cases that don't end with newlines
685 * but should be written without one:
686 * The "[nn]kdb> " prompt should
687 * appear at the front of the buffer.
688 *
689 * The "[nn]more " prompt should also be
690 * (MOREPROMPT -> moreprompt)
691 * written * but we print that ourselves,
692 * we set the suspend_grep flag to make
693 * it unconditional.
694 *
695 */
696 if (next_avail == kdb_buffer) {
697 /*
698 * these should occur after a newline,
699 * so they will be at the front of the
700 * buffer
701 */
702 cp2 = kdb_buffer;
703 len = strlen(kdb_prompt_str);
704 if (!strncmp(cp2, kdb_prompt_str, len)) {
705 /*
706 * We're about to start a new
707 * command, so we can go back
708 * to normal mode.
709 */
710 kdb_grepping_flag = 0;
711 goto kdb_printit;
712 }
713 }
714 /* no newline; don't search/write the buffer
715 until one is there */
716 len = strlen(kdb_buffer);
717 next_avail = kdb_buffer + len;
718 size_avail = sizeof(kdb_buffer) - len;
719 goto kdb_print_out;
720 }
721
722 /*
723 * The newline is present; print through it or discard
724 * it, depending on the results of the search.
725 */
726 cp++; /* to byte after the newline */
727 replaced_byte = *cp; /* remember what/where it was */
728 cphold = cp;
729 *cp = '\0'; /* end the string for our search */
730
731 /*
732 * We now have a newline at the end of the string
733 * Only continue with this output if it contains the
734 * search string.
735 */
736 fnd = kdb_search_string(kdb_buffer, kdb_grep_string);
737 if (!fnd) {
738 /*
739 * At this point the complete line at the start
740 * of kdb_buffer can be discarded, as it does
741 * not contain what the user is looking for.
742 * Shift the buffer left.
743 */
744 *cphold = replaced_byte;
745 strcpy(kdb_buffer, cphold);
746 len = strlen(kdb_buffer);
747 next_avail = kdb_buffer + len;
748 size_avail = sizeof(kdb_buffer) - len;
749 goto kdb_print_out;
750 }
751 if (kdb_grepping_flag >= KDB_GREPPING_FLAG_SEARCH) {
752 /*
753 * This was a interactive search (using '/' at more
754 * prompt) and it has completed. Replace the \0 with
755 * its original value to ensure multi-line strings
756 * are handled properly, and return to normal mode.
757 */
758 *cphold = replaced_byte;
759 kdb_grepping_flag = 0;
760 }
761 /*
762 * at this point the string is a full line and
763 * should be printed, up to the null.
764 */
765 }
766 kdb_printit:
767
768 /*
769 * Write to all consoles.
770 */
771 retlen = strlen(kdb_buffer);
772 cp = (char *) printk_skip_headers(kdb_buffer);
773 if (!dbg_kdb_mode && kgdb_connected)
774 gdbstub_msg_write(cp, retlen - (cp - kdb_buffer));
775 else
776 kdb_msg_write(cp, retlen - (cp - kdb_buffer));
777
778 if (logging) {
779 saved_loglevel = console_loglevel;
780 console_loglevel = CONSOLE_LOGLEVEL_SILENT;
781 if (printk_get_level(kdb_buffer) || src == KDB_MSGSRC_PRINTK)
782 printk("%s", kdb_buffer);
783 else
784 pr_info("%s", kdb_buffer);
785 }
786
787 if (KDB_STATE(PAGER)) {
788 /*
789 * Check printed string to decide how to bump the
790 * kdb_nextline to control when the more prompt should
791 * show up.
792 */
793 int got = 0;
794 len = retlen;
795 while (len--) {
796 if (kdb_buffer[len] == '\n') {
797 kdb_nextline++;
798 got = 0;
799 } else if (kdb_buffer[len] == '\r') {
800 got = 0;
801 } else {
802 got++;
803 }
804 }
805 kdb_nextline += got / (colcount + 1);
806 }
807
808 /* check for having reached the LINES number of printed lines */
809 if (kdb_nextline >= linecount) {
810 char ch;
811
812 /* Watch out for recursion here. Any routine that calls
813 * kdb_printf will come back through here. And kdb_read
814 * uses kdb_printf to echo on serial consoles ...
815 */
816 kdb_nextline = 1; /* In case of recursion */
817
818 /*
819 * Pause until cr.
820 */
821 moreprompt = kdbgetenv("MOREPROMPT");
822 if (moreprompt == NULL)
823 moreprompt = "more> ";
824
825 kdb_input_flush();
826 kdb_msg_write(moreprompt, strlen(moreprompt));
827
828 if (logging)
829 printk("%s", moreprompt);
830
831 ch = kdb_getchar();
832 kdb_nextline = 1; /* Really set output line 1 */
833
834 /* empty and reset the buffer: */
835 kdb_buffer[0] = '\0';
836 next_avail = kdb_buffer;
837 size_avail = sizeof(kdb_buffer);
838 if ((ch == 'q') || (ch == 'Q')) {
839 /* user hit q or Q */
840 KDB_FLAG_SET(CMD_INTERRUPT); /* command interrupted */
841 KDB_STATE_CLEAR(PAGER);
842 /* end of command output; back to normal mode */
843 kdb_grepping_flag = 0;
844 kdb_printf("\n");
845 } else if (ch == ' ') {
846 kdb_printf("\r");
847 suspend_grep = 1; /* for this recursion */
848 } else if (ch == '\n' || ch == '\r') {
849 kdb_nextline = linecount - 1;
850 kdb_printf("\r");
851 suspend_grep = 1; /* for this recursion */
852 } else if (ch == '/' && !kdb_grepping_flag) {
853 kdb_printf("\r");
854 kdb_getstr(kdb_grep_string, KDB_GREP_STRLEN,
855 kdbgetenv("SEARCHPROMPT") ?: "search> ");
856 *strchrnul(kdb_grep_string, '\n') = '\0';
857 kdb_grepping_flag += KDB_GREPPING_FLAG_SEARCH;
858 suspend_grep = 1; /* for this recursion */
859 } else if (ch) {
860 /* user hit something unexpected */
861 suspend_grep = 1; /* for this recursion */
862 if (ch != '/')
863 kdb_printf(
864 "\nOnly 'q', 'Q' or '/' are processed at "
865 "more prompt, input ignored\n");
866 else
867 kdb_printf("\n'/' cannot be used during | "
868 "grep filtering, input ignored\n");
869 } else if (kdb_grepping_flag) {
870 /* user hit enter */
871 suspend_grep = 1; /* for this recursion */
872 kdb_printf("\n");
873 }
874 kdb_input_flush();
875 }
876
877 /*
878 * For grep searches, shift the printed string left.
879 * replaced_byte contains the character that was overwritten with
880 * the terminating null, and cphold points to the null.
881 * Then adjust the notion of available space in the buffer.
882 */
883 if (kdb_grepping_flag && !suspend_grep) {
884 *cphold = replaced_byte;
885 strcpy(kdb_buffer, cphold);
886 len = strlen(kdb_buffer);
887 next_avail = kdb_buffer + len;
888 size_avail = sizeof(kdb_buffer) - len;
889 }
890
891 kdb_print_out:
892 suspend_grep = 0; /* end of what may have been a recursive call */
893 if (logging)
894 console_loglevel = saved_loglevel;
895 /* kdb_printf_cpu locked the code above. */
896 smp_store_release(&kdb_printf_cpu, old_cpu);
897 local_irq_restore(flags);
898 return retlen;
899 }
900
kdb_printf(const char * fmt,...)901 int kdb_printf(const char *fmt, ...)
902 {
903 va_list ap;
904 int r;
905
906 va_start(ap, fmt);
907 r = vkdb_printf(KDB_MSGSRC_INTERNAL, fmt, ap);
908 va_end(ap);
909
910 return r;
911 }
912 EXPORT_SYMBOL_GPL(kdb_printf);
913