Commit | Line | Data |
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5d5314d6 JW |
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 | ||
5d5314d6 JW |
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> | |
a0de055c | 23 | #include <linux/kgdb.h> |
5d5314d6 JW |
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 | ||
d37d39ae | 31 | int kdb_trap_printk; |
34aaff40 | 32 | int kdb_printf_cpu = -1; |
5d5314d6 | 33 | |
37f86b46 | 34 | static int kgdb_transition_check(char *buffer) |
5d5314d6 | 35 | { |
37f86b46 | 36 | if (buffer[0] != '+' && buffer[0] != '$') { |
5d5314d6 JW |
37 | KDB_STATE_SET(KGDB_TRANS); |
38 | kdb_printf("%s", buffer); | |
37f86b46 JW |
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 | } | |
5d5314d6 | 47 | } |
37f86b46 | 48 | return 0; |
5d5314d6 JW |
49 | } |
50 | ||
53b63136 DT |
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 | */ | |
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 | ||
4f27e824 DT |
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 | */ | |
125 | char kdb_getchar(void) | |
5d5314d6 JW |
126 | { |
127 | #define ESCAPE_UDELAY 1000 | |
128 | #define ESCAPE_DELAY (2*1000000/ESCAPE_UDELAY) /* 2 seconds worth of udelays */ | |
cdca8d89 DT |
129 | char buf[4]; /* longest vt100 escape sequence is 4 bytes */ |
130 | char *pbuf = buf; | |
5d5314d6 | 131 | int escape_delay = 0; |
cdca8d89 | 132 | get_char_func *f, *f_prev = NULL; |
5d5314d6 | 133 | int key; |
1ed05558 | 134 | static bool last_char_was_cr; |
5d5314d6 JW |
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 | } | |
d04213af | 142 | |
5d5314d6 JW |
143 | key = (*f)(); |
144 | if (key == -1) { | |
145 | if (escape_delay) { | |
146 | udelay(ESCAPE_UDELAY); | |
d04213af DT |
147 | if (--escape_delay == 0) |
148 | return '\e'; | |
5d5314d6 JW |
149 | } |
150 | continue; | |
151 | } | |
d04213af | 152 | |
1ed05558 DA |
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 | ||
cdca8d89 DT |
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; | |
5d5314d6 | 173 | escape_delay = ESCAPE_DELAY; |
5d5314d6 | 174 | } |
d04213af | 175 | |
cdca8d89 DT |
176 | *pbuf++ = key; |
177 | key = kdb_handle_escape(buf, pbuf - buf); | |
c58ff643 DT |
178 | if (key < 0) /* no escape sequence; return best character */ |
179 | return buf[pbuf - buf == 2 ? 1 : 0]; | |
cdca8d89 DT |
180 | if (key > 0) |
181 | return key; | |
5d5314d6 | 182 | } |
cdca8d89 DT |
183 | |
184 | unreachable(); | |
5d5314d6 JW |
185 | } |
186 | ||
09b35989 DT |
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 | */ | |
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 | ||
5d5314d6 JW |
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: | |
4f27e824 | 232 | * The buffer size must be >= 2. |
5d5314d6 JW |
233 | */ |
234 | ||
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; | |
5d5314d6 JW |
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; | |
c2b94c72 | 249 | int key, buf_size, ret; |
5d5314d6 JW |
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: | |
4f27e824 | 266 | key = kdb_getchar(); |
5d5314d6 JW |
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; | |
09b35989 DT |
278 | kdb_printf("\b%s ", cp); |
279 | kdb_position_cursor(kdb_prompt_str, buffer, cp); | |
5d5314d6 JW |
280 | } |
281 | break; | |
1ed05558 DA |
282 | case 10: /* linefeed */ |
283 | case 13: /* carriage return */ | |
5d5314d6 JW |
284 | *lastchar++ = '\n'; |
285 | *lastchar++ = '\0'; | |
37f86b46 JW |
286 | if (!KDB_STATE(KGDB_TRANS)) { |
287 | KDB_STATE_SET(KGDB_TRANS); | |
288 | kdb_printf("%s", buffer); | |
289 | } | |
5d5314d6 JW |
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'; | |
09b35989 DT |
297 | kdb_printf("%s ", cp); |
298 | kdb_position_cursor(kdb_prompt_str, buffer, cp); | |
5d5314d6 JW |
299 | } |
300 | break; | |
301 | case 1: /* Home */ | |
302 | if (cp > buffer) { | |
5d5314d6 | 303 | cp = buffer; |
09b35989 | 304 | kdb_position_cursor(kdb_prompt_str, buffer, cp); |
5d5314d6 JW |
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 */ | |
6244917f | 320 | case 16: /* Up */ |
5d5314d6 JW |
321 | memset(tmpbuffer, ' ', |
322 | strlen(kdb_prompt_str) + (lastchar-buffer)); | |
323 | *(tmpbuffer+strlen(kdb_prompt_str) + | |
324 | (lastchar-buffer)) = '\0'; | |
325 | kdb_printf("\r%s\r", tmpbuffer); | |
326 | *lastchar = (char)key; | |
327 | *(lastchar+1) = '\0'; | |
328 | return lastchar; | |
329 | case 6: /* Right */ | |
330 | if (cp < lastchar) { | |
331 | kdb_printf("%c", *cp); | |
332 | ++cp; | |
333 | } | |
334 | break; | |
5d5314d6 JW |
335 | case 9: /* Tab */ |
336 | if (tab < 2) | |
337 | ++tab; | |
338 | p_tmp = buffer; | |
339 | while (*p_tmp == ' ') | |
340 | p_tmp++; | |
341 | if (p_tmp > cp) | |
342 | break; | |
343 | memcpy(tmpbuffer, p_tmp, cp-p_tmp); | |
344 | *(tmpbuffer + (cp-p_tmp)) = '\0'; | |
345 | p_tmp = strrchr(tmpbuffer, ' '); | |
346 | if (p_tmp) | |
347 | ++p_tmp; | |
348 | else | |
349 | p_tmp = tmpbuffer; | |
350 | len = strlen(p_tmp); | |
c2b94c72 PB |
351 | buf_size = sizeof(tmpbuffer) - (p_tmp - tmpbuffer); |
352 | count = kallsyms_symbol_complete(p_tmp, buf_size); | |
5d5314d6 JW |
353 | if (tab == 2 && count > 0) { |
354 | kdb_printf("\n%d symbols are found.", count); | |
355 | if (count > dtab_count) { | |
356 | count = dtab_count; | |
357 | kdb_printf(" But only first %d symbols will" | |
358 | " be printed.\nYou can change the" | |
359 | " environment variable DTABCOUNT.", | |
360 | count); | |
361 | } | |
362 | kdb_printf("\n"); | |
363 | for (i = 0; i < count; i++) { | |
c2b94c72 PB |
364 | ret = kallsyms_symbol_next(p_tmp, i, buf_size); |
365 | if (WARN_ON(!ret)) | |
5d5314d6 | 366 | break; |
c2b94c72 PB |
367 | if (ret != -E2BIG) |
368 | kdb_printf("%s ", p_tmp); | |
369 | else | |
370 | kdb_printf("%s... ", p_tmp); | |
5d5314d6 JW |
371 | *(p_tmp + len) = '\0'; |
372 | } | |
373 | if (i >= dtab_count) | |
374 | kdb_printf("..."); | |
375 | kdb_printf("\n"); | |
376 | kdb_printf(kdb_prompt_str); | |
377 | kdb_printf("%s", buffer); | |
db2f9c7d DT |
378 | if (cp != lastchar) |
379 | kdb_position_cursor(kdb_prompt_str, buffer, cp); | |
5d5314d6 | 380 | } else if (tab != 2 && count > 0) { |
e9730744 DT |
381 | /* How many new characters do we want from tmpbuffer? */ |
382 | len_tmp = strlen(p_tmp) - len; | |
383 | if (lastchar + len_tmp >= bufend) | |
384 | len_tmp = bufend - lastchar; | |
385 | ||
386 | if (len_tmp) { | |
387 | /* + 1 ensures the '\0' is memmove'd */ | |
388 | memmove(cp+len_tmp, cp, (lastchar-cp) + 1); | |
389 | memcpy(cp, p_tmp+len, len_tmp); | |
390 | kdb_printf("%s", cp); | |
391 | cp += len_tmp; | |
392 | lastchar += len_tmp; | |
db2f9c7d DT |
393 | if (cp != lastchar) |
394 | kdb_position_cursor(kdb_prompt_str, | |
395 | buffer, cp); | |
e9730744 | 396 | } |
5d5314d6 JW |
397 | } |
398 | kdb_nextline = 1; /* reset output line number */ | |
399 | break; | |
400 | default: | |
401 | if (key >= 32 && lastchar < bufend) { | |
402 | if (cp < lastchar) { | |
403 | memcpy(tmpbuffer, cp, lastchar - cp); | |
404 | memcpy(cp+1, tmpbuffer, lastchar - cp); | |
405 | *++lastchar = '\0'; | |
406 | *cp = key; | |
09b35989 | 407 | kdb_printf("%s", cp); |
5d5314d6 | 408 | ++cp; |
09b35989 | 409 | kdb_position_cursor(kdb_prompt_str, buffer, cp); |
5d5314d6 JW |
410 | } else { |
411 | *++lastchar = '\0'; | |
412 | *cp++ = key; | |
413 | /* The kgdb transition check will hide | |
414 | * printed characters if we think that | |
415 | * kgdb is connecting, until the check | |
416 | * fails */ | |
37f86b46 JW |
417 | if (!KDB_STATE(KGDB_TRANS)) { |
418 | if (kgdb_transition_check(buffer)) | |
419 | return buffer; | |
420 | } else { | |
5d5314d6 | 421 | kdb_printf("%c", key); |
37f86b46 | 422 | } |
5d5314d6 JW |
423 | } |
424 | /* Special escape to kgdb */ | |
425 | if (lastchar - buffer >= 5 && | |
426 | strcmp(lastchar - 5, "$?#3f") == 0) { | |
f679c498 | 427 | kdb_gdb_state_pass(lastchar - 5); |
5d5314d6 JW |
428 | strcpy(buffer, "kgdb"); |
429 | KDB_STATE_SET(DOING_KGDB); | |
430 | return buffer; | |
431 | } | |
f679c498 JW |
432 | if (lastchar - buffer >= 11 && |
433 | strcmp(lastchar - 11, "$qSupported") == 0) { | |
434 | kdb_gdb_state_pass(lastchar - 11); | |
5d5314d6 | 435 | strcpy(buffer, "kgdb"); |
d613d828 | 436 | KDB_STATE_SET(DOING_KGDB); |
5d5314d6 JW |
437 | return buffer; |
438 | } | |
439 | } | |
440 | break; | |
441 | } | |
442 | goto poll_again; | |
443 | } | |
444 | ||
445 | /* | |
446 | * kdb_getstr | |
447 | * | |
448 | * Print the prompt string and read a command from the | |
449 | * input device. | |
450 | * | |
451 | * Parameters: | |
452 | * buffer Address of buffer to receive command | |
453 | * bufsize Size of buffer in bytes | |
454 | * prompt Pointer to string to use as prompt string | |
455 | * Returns: | |
456 | * Pointer to command buffer. | |
457 | * Locking: | |
458 | * None. | |
459 | * Remarks: | |
460 | * For SMP kernels, the processor number will be | |
461 | * substituted for %d, %x or %o in the prompt. | |
462 | */ | |
463 | ||
32d375f6 | 464 | char *kdb_getstr(char *buffer, size_t bufsize, const char *prompt) |
5d5314d6 JW |
465 | { |
466 | if (prompt && kdb_prompt_str != prompt) | |
ca976bfb | 467 | strscpy(kdb_prompt_str, prompt, CMD_BUFLEN); |
5d5314d6 JW |
468 | kdb_printf(kdb_prompt_str); |
469 | kdb_nextline = 1; /* Prompt and input resets line number */ | |
470 | return kdb_read(buffer, bufsize); | |
471 | } | |
472 | ||
473 | /* | |
474 | * kdb_input_flush | |
475 | * | |
476 | * Get rid of any buffered console input. | |
477 | * | |
478 | * Parameters: | |
479 | * none | |
480 | * Returns: | |
481 | * nothing | |
482 | * Locking: | |
483 | * none | |
484 | * Remarks: | |
485 | * Call this function whenever you want to flush input. If there is any | |
486 | * outstanding input, it ignores all characters until there has been no | |
487 | * data for approximately 1ms. | |
488 | */ | |
489 | ||
490 | static void kdb_input_flush(void) | |
491 | { | |
492 | get_char_func *f; | |
493 | int res; | |
494 | int flush_delay = 1; | |
495 | while (flush_delay) { | |
496 | flush_delay--; | |
497 | empty: | |
498 | touch_nmi_watchdog(); | |
499 | for (f = &kdb_poll_funcs[0]; *f; ++f) { | |
500 | res = (*f)(); | |
501 | if (res != -1) { | |
502 | flush_delay = 1; | |
503 | goto empty; | |
504 | } | |
505 | } | |
506 | if (flush_delay) | |
507 | mdelay(1); | |
508 | } | |
509 | } | |
510 | ||
511 | /* | |
512 | * kdb_printf | |
513 | * | |
514 | * Print a string to the output device(s). | |
515 | * | |
516 | * Parameters: | |
517 | * printf-like format and optional args. | |
518 | * Returns: | |
519 | * 0 | |
520 | * Locking: | |
521 | * None. | |
522 | * Remarks: | |
523 | * use 'kdbcons->write()' to avoid polluting 'log_buf' with | |
524 | * kdb output. | |
525 | * | |
526 | * If the user is doing a cmd args | grep srch | |
527 | * then kdb_grepping_flag is set. | |
528 | * In that case we need to accumulate full lines (ending in \n) before | |
529 | * searching for the pattern. | |
530 | */ | |
531 | ||
532 | static char kdb_buffer[256]; /* A bit too big to go on stack */ | |
533 | static char *next_avail = kdb_buffer; | |
534 | static int size_avail; | |
535 | static int suspend_grep; | |
536 | ||
537 | /* | |
538 | * search arg1 to see if it contains arg2 | |
539 | * (kdmain.c provides flags for ^pat and pat$) | |
540 | * | |
541 | * return 1 for found, 0 for not found | |
542 | */ | |
543 | static int kdb_search_string(char *searched, char *searchfor) | |
544 | { | |
545 | char firstchar, *cp; | |
546 | int len1, len2; | |
547 | ||
548 | /* not counting the newline at the end of "searched" */ | |
549 | len1 = strlen(searched)-1; | |
550 | len2 = strlen(searchfor); | |
551 | if (len1 < len2) | |
552 | return 0; | |
553 | if (kdb_grep_leading && kdb_grep_trailing && len1 != len2) | |
554 | return 0; | |
555 | if (kdb_grep_leading) { | |
556 | if (!strncmp(searched, searchfor, len2)) | |
557 | return 1; | |
558 | } else if (kdb_grep_trailing) { | |
559 | if (!strncmp(searched+len1-len2, searchfor, len2)) | |
560 | return 1; | |
561 | } else { | |
562 | firstchar = *searchfor; | |
563 | cp = searched; | |
564 | while ((cp = strchr(cp, firstchar))) { | |
565 | if (!strncmp(cp, searchfor, len2)) | |
566 | return 1; | |
567 | cp++; | |
568 | } | |
569 | } | |
570 | return 0; | |
571 | } | |
572 | ||
9d71b344 SG |
573 | static void kdb_msg_write(const char *msg, int msg_len) |
574 | { | |
575 | struct console *c; | |
fcdb84cc | 576 | const char *cp; |
b8ef04be | 577 | int cookie; |
fcdb84cc | 578 | int len; |
9d71b344 SG |
579 | |
580 | if (msg_len == 0) | |
581 | return; | |
582 | ||
fcdb84cc CC |
583 | cp = msg; |
584 | len = msg_len; | |
9d71b344 | 585 | |
fcdb84cc CC |
586 | while (len--) { |
587 | dbg_io_ops->write_char(*cp); | |
588 | cp++; | |
9d71b344 SG |
589 | } |
590 | ||
b8ef04be JO |
591 | /* |
592 | * The console_srcu_read_lock() only provides safe console list | |
593 | * traversal. The use of the ->write() callback relies on all other | |
594 | * CPUs being stopped at the moment and console drivers being able to | |
595 | * handle reentrance when @oops_in_progress is set. | |
596 | * | |
597 | * There is no guarantee that every console driver can handle | |
598 | * reentrance in this way; the developer deploying the debugger | |
599 | * is responsible for ensuring that the console drivers they | |
600 | * have selected handle reentrance appropriately. | |
601 | */ | |
602 | cookie = console_srcu_read_lock(); | |
603 | for_each_console_srcu(c) { | |
604 | if (!(console_srcu_read_flags(c) & CON_ENABLED)) | |
e8857288 | 605 | continue; |
5946d1f5 SG |
606 | if (c == dbg_io_ops->cons) |
607 | continue; | |
6d3e0d8c JO |
608 | if (!c->write) |
609 | continue; | |
2a78b85b SG |
610 | /* |
611 | * Set oops_in_progress to encourage the console drivers to | |
612 | * disregard their internal spin locks: in the current calling | |
613 | * context the risk of deadlock is a bigger problem than risks | |
614 | * due to re-entering the console driver. We operate directly on | |
615 | * oops_in_progress rather than using bust_spinlocks() because | |
616 | * the calls bust_spinlocks() makes on exit are not appropriate | |
617 | * for this calling context. | |
618 | */ | |
619 | ++oops_in_progress; | |
9d71b344 | 620 | c->write(c, msg, msg_len); |
2a78b85b | 621 | --oops_in_progress; |
9d71b344 SG |
622 | touch_nmi_watchdog(); |
623 | } | |
b8ef04be | 624 | console_srcu_read_unlock(cookie); |
9d71b344 SG |
625 | } |
626 | ||
f7d4ca8b | 627 | int vkdb_printf(enum kdb_msgsrc src, const char *fmt, va_list ap) |
5d5314d6 | 628 | { |
5d5314d6 JW |
629 | int diag; |
630 | int linecount; | |
17b572e8 | 631 | int colcount; |
5d5314d6 | 632 | int logging, saved_loglevel = 0; |
5d5314d6 JW |
633 | int retlen = 0; |
634 | int fnd, len; | |
d5d8d3d0 | 635 | int this_cpu, old_cpu; |
5d5314d6 JW |
636 | char *cp, *cp2, *cphold = NULL, replaced_byte = ' '; |
637 | char *moreprompt = "more> "; | |
3f649ab7 | 638 | unsigned long flags; |
5d5314d6 | 639 | |
5d5314d6 JW |
640 | /* Serialize kdb_printf if multiple cpus try to write at once. |
641 | * But if any cpu goes recursive in kdb, just print the output, | |
642 | * even if it is interleaved with any other text. | |
643 | */ | |
34aaff40 | 644 | local_irq_save(flags); |
d5d8d3d0 PM |
645 | this_cpu = smp_processor_id(); |
646 | for (;;) { | |
647 | old_cpu = cmpxchg(&kdb_printf_cpu, -1, this_cpu); | |
648 | if (old_cpu == -1 || old_cpu == this_cpu) | |
649 | break; | |
650 | ||
651 | cpu_relax(); | |
5d5314d6 JW |
652 | } |
653 | ||
654 | diag = kdbgetintenv("LINES", &linecount); | |
655 | if (diag || linecount <= 1) | |
656 | linecount = 24; | |
657 | ||
17b572e8 JW |
658 | diag = kdbgetintenv("COLUMNS", &colcount); |
659 | if (diag || colcount <= 1) | |
660 | colcount = 80; | |
661 | ||
5d5314d6 JW |
662 | diag = kdbgetintenv("LOGGING", &logging); |
663 | if (diag) | |
664 | logging = 0; | |
665 | ||
666 | if (!kdb_grepping_flag || suspend_grep) { | |
667 | /* normally, every vsnprintf starts a new buffer */ | |
668 | next_avail = kdb_buffer; | |
669 | size_avail = sizeof(kdb_buffer); | |
670 | } | |
5d5314d6 | 671 | vsnprintf(next_avail, size_avail, fmt, ap); |
5d5314d6 JW |
672 | |
673 | /* | |
674 | * If kdb_parse() found that the command was cmd xxx | grep yyy | |
675 | * then kdb_grepping_flag is set, and kdb_grep_string contains yyy | |
676 | * | |
677 | * Accumulate the print data up to a newline before searching it. | |
678 | * (vsnprintf does null-terminate the string that it generates) | |
679 | */ | |
680 | ||
681 | /* skip the search if prints are temporarily unconditional */ | |
682 | if (!suspend_grep && kdb_grepping_flag) { | |
683 | cp = strchr(kdb_buffer, '\n'); | |
684 | if (!cp) { | |
685 | /* | |
686 | * Special cases that don't end with newlines | |
687 | * but should be written without one: | |
688 | * The "[nn]kdb> " prompt should | |
689 | * appear at the front of the buffer. | |
690 | * | |
691 | * The "[nn]more " prompt should also be | |
692 | * (MOREPROMPT -> moreprompt) | |
693 | * written * but we print that ourselves, | |
694 | * we set the suspend_grep flag to make | |
695 | * it unconditional. | |
696 | * | |
697 | */ | |
698 | if (next_avail == kdb_buffer) { | |
699 | /* | |
700 | * these should occur after a newline, | |
701 | * so they will be at the front of the | |
702 | * buffer | |
703 | */ | |
704 | cp2 = kdb_buffer; | |
705 | len = strlen(kdb_prompt_str); | |
706 | if (!strncmp(cp2, kdb_prompt_str, len)) { | |
707 | /* | |
708 | * We're about to start a new | |
709 | * command, so we can go back | |
710 | * to normal mode. | |
711 | */ | |
712 | kdb_grepping_flag = 0; | |
713 | goto kdb_printit; | |
714 | } | |
715 | } | |
716 | /* no newline; don't search/write the buffer | |
717 | until one is there */ | |
718 | len = strlen(kdb_buffer); | |
719 | next_avail = kdb_buffer + len; | |
720 | size_avail = sizeof(kdb_buffer) - len; | |
721 | goto kdb_print_out; | |
722 | } | |
723 | ||
724 | /* | |
725 | * The newline is present; print through it or discard | |
726 | * it, depending on the results of the search. | |
727 | */ | |
728 | cp++; /* to byte after the newline */ | |
729 | replaced_byte = *cp; /* remember what/where it was */ | |
730 | cphold = cp; | |
731 | *cp = '\0'; /* end the string for our search */ | |
732 | ||
733 | /* | |
734 | * We now have a newline at the end of the string | |
735 | * Only continue with this output if it contains the | |
736 | * search string. | |
737 | */ | |
738 | fnd = kdb_search_string(kdb_buffer, kdb_grep_string); | |
739 | if (!fnd) { | |
740 | /* | |
741 | * At this point the complete line at the start | |
742 | * of kdb_buffer can be discarded, as it does | |
743 | * not contain what the user is looking for. | |
744 | * Shift the buffer left. | |
745 | */ | |
746 | *cphold = replaced_byte; | |
747 | strcpy(kdb_buffer, cphold); | |
748 | len = strlen(kdb_buffer); | |
749 | next_avail = kdb_buffer + len; | |
750 | size_avail = sizeof(kdb_buffer) - len; | |
751 | goto kdb_print_out; | |
752 | } | |
d081a6e3 | 753 | if (kdb_grepping_flag >= KDB_GREPPING_FLAG_SEARCH) { |
fb6daa75 DT |
754 | /* |
755 | * This was a interactive search (using '/' at more | |
d081a6e3 DT |
756 | * prompt) and it has completed. Replace the \0 with |
757 | * its original value to ensure multi-line strings | |
758 | * are handled properly, and return to normal mode. | |
fb6daa75 | 759 | */ |
d081a6e3 | 760 | *cphold = replaced_byte; |
fb6daa75 | 761 | kdb_grepping_flag = 0; |
d081a6e3 | 762 | } |
5d5314d6 JW |
763 | /* |
764 | * at this point the string is a full line and | |
765 | * should be printed, up to the null. | |
766 | */ | |
767 | } | |
768 | kdb_printit: | |
769 | ||
770 | /* | |
771 | * Write to all consoles. | |
772 | */ | |
773 | retlen = strlen(kdb_buffer); | |
49795757 | 774 | cp = (char *) printk_skip_headers(kdb_buffer); |
9d71b344 | 775 | if (!dbg_kdb_mode && kgdb_connected) |
f7d4ca8b | 776 | gdbstub_msg_write(cp, retlen - (cp - kdb_buffer)); |
9d71b344 SG |
777 | else |
778 | kdb_msg_write(cp, retlen - (cp - kdb_buffer)); | |
779 | ||
5d5314d6 JW |
780 | if (logging) { |
781 | saved_loglevel = console_loglevel; | |
a8fe19eb | 782 | console_loglevel = CONSOLE_LOGLEVEL_SILENT; |
f7d4ca8b DT |
783 | if (printk_get_level(kdb_buffer) || src == KDB_MSGSRC_PRINTK) |
784 | printk("%s", kdb_buffer); | |
785 | else | |
786 | pr_info("%s", kdb_buffer); | |
5d5314d6 JW |
787 | } |
788 | ||
17b572e8 JW |
789 | if (KDB_STATE(PAGER)) { |
790 | /* | |
791 | * Check printed string to decide how to bump the | |
792 | * kdb_nextline to control when the more prompt should | |
793 | * show up. | |
794 | */ | |
795 | int got = 0; | |
796 | len = retlen; | |
797 | while (len--) { | |
798 | if (kdb_buffer[len] == '\n') { | |
799 | kdb_nextline++; | |
800 | got = 0; | |
801 | } else if (kdb_buffer[len] == '\r') { | |
802 | got = 0; | |
803 | } else { | |
804 | got++; | |
805 | } | |
806 | } | |
807 | kdb_nextline += got / (colcount + 1); | |
808 | } | |
5d5314d6 JW |
809 | |
810 | /* check for having reached the LINES number of printed lines */ | |
17b572e8 | 811 | if (kdb_nextline >= linecount) { |
4f27e824 | 812 | char ch; |
5d5314d6 JW |
813 | |
814 | /* Watch out for recursion here. Any routine that calls | |
815 | * kdb_printf will come back through here. And kdb_read | |
816 | * uses kdb_printf to echo on serial consoles ... | |
817 | */ | |
818 | kdb_nextline = 1; /* In case of recursion */ | |
819 | ||
820 | /* | |
821 | * Pause until cr. | |
822 | */ | |
823 | moreprompt = kdbgetenv("MOREPROMPT"); | |
824 | if (moreprompt == NULL) | |
825 | moreprompt = "more> "; | |
826 | ||
5d5314d6 | 827 | kdb_input_flush(); |
9d71b344 | 828 | kdb_msg_write(moreprompt, strlen(moreprompt)); |
5d5314d6 JW |
829 | |
830 | if (logging) | |
831 | printk("%s", moreprompt); | |
832 | ||
4f27e824 | 833 | ch = kdb_getchar(); |
5d5314d6 JW |
834 | kdb_nextline = 1; /* Really set output line 1 */ |
835 | ||
836 | /* empty and reset the buffer: */ | |
837 | kdb_buffer[0] = '\0'; | |
838 | next_avail = kdb_buffer; | |
839 | size_avail = sizeof(kdb_buffer); | |
4f27e824 | 840 | if ((ch == 'q') || (ch == 'Q')) { |
5d5314d6 JW |
841 | /* user hit q or Q */ |
842 | KDB_FLAG_SET(CMD_INTERRUPT); /* command interrupted */ | |
843 | KDB_STATE_CLEAR(PAGER); | |
844 | /* end of command output; back to normal mode */ | |
845 | kdb_grepping_flag = 0; | |
846 | kdb_printf("\n"); | |
4f27e824 | 847 | } else if (ch == ' ') { |
17b572e8 | 848 | kdb_printf("\r"); |
5d5314d6 | 849 | suspend_grep = 1; /* for this recursion */ |
4f27e824 | 850 | } else if (ch == '\n' || ch == '\r') { |
5d5314d6 JW |
851 | kdb_nextline = linecount - 1; |
852 | kdb_printf("\r"); | |
853 | suspend_grep = 1; /* for this recursion */ | |
4f27e824 | 854 | } else if (ch == '/' && !kdb_grepping_flag) { |
fb6daa75 DT |
855 | kdb_printf("\r"); |
856 | kdb_getstr(kdb_grep_string, KDB_GREP_STRLEN, | |
857 | kdbgetenv("SEARCHPROMPT") ?: "search> "); | |
858 | *strchrnul(kdb_grep_string, '\n') = '\0'; | |
859 | kdb_grepping_flag += KDB_GREPPING_FLAG_SEARCH; | |
860 | suspend_grep = 1; /* for this recursion */ | |
4f27e824 DT |
861 | } else if (ch) { |
862 | /* user hit something unexpected */ | |
5d5314d6 | 863 | suspend_grep = 1; /* for this recursion */ |
4f27e824 | 864 | if (ch != '/') |
fb6daa75 DT |
865 | kdb_printf( |
866 | "\nOnly 'q', 'Q' or '/' are processed at " | |
867 | "more prompt, input ignored\n"); | |
868 | else | |
869 | kdb_printf("\n'/' cannot be used during | " | |
870 | "grep filtering, input ignored\n"); | |
5d5314d6 JW |
871 | } else if (kdb_grepping_flag) { |
872 | /* user hit enter */ | |
873 | suspend_grep = 1; /* for this recursion */ | |
874 | kdb_printf("\n"); | |
875 | } | |
876 | kdb_input_flush(); | |
877 | } | |
878 | ||
879 | /* | |
880 | * For grep searches, shift the printed string left. | |
881 | * replaced_byte contains the character that was overwritten with | |
882 | * the terminating null, and cphold points to the null. | |
883 | * Then adjust the notion of available space in the buffer. | |
884 | */ | |
885 | if (kdb_grepping_flag && !suspend_grep) { | |
886 | *cphold = replaced_byte; | |
887 | strcpy(kdb_buffer, cphold); | |
888 | len = strlen(kdb_buffer); | |
889 | next_avail = kdb_buffer + len; | |
890 | size_avail = sizeof(kdb_buffer) - len; | |
891 | } | |
892 | ||
893 | kdb_print_out: | |
894 | suspend_grep = 0; /* end of what may have been a recursive call */ | |
895 | if (logging) | |
896 | console_loglevel = saved_loglevel; | |
d5d8d3d0 PM |
897 | /* kdb_printf_cpu locked the code above. */ |
898 | smp_store_release(&kdb_printf_cpu, old_cpu); | |
d5d8d3d0 | 899 | local_irq_restore(flags); |
5d5314d6 JW |
900 | return retlen; |
901 | } | |
d37d39ae JW |
902 | |
903 | int kdb_printf(const char *fmt, ...) | |
904 | { | |
905 | va_list ap; | |
906 | int r; | |
907 | ||
908 | va_start(ap, fmt); | |
f7d4ca8b | 909 | r = vkdb_printf(KDB_MSGSRC_INTERNAL, fmt, ap); |
d37d39ae JW |
910 | va_end(ap); |
911 | ||
912 | return r; | |
913 | } | |
f7030bbc | 914 | EXPORT_SYMBOL_GPL(kdb_printf); |