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 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 */ 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 */ 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 */ 207 static void kdb_position_cursor(char *prompt, char *buffer, char *cp) 208 { 209 kdb_printf("\r%s", prompt); 210 if (cp > buffer) 211 kdb_printf("%.*s", (int)(cp - buffer), buffer); 212 } 213 214 /* 215 * kdb_read 216 * 217 * This function reads a string of characters, terminated by 218 * a newline, or by reaching the end of the supplied buffer, 219 * from the current kernel debugger console device. 220 * Parameters: 221 * buffer - Address of character buffer to receive input characters. 222 * bufsize - size, in bytes, of the character buffer 223 * Returns: 224 * Returns a pointer to the buffer containing the received 225 * character string. This string will be terminated by a 226 * newline character. 227 * Locking: 228 * No locks are required to be held upon entry to this 229 * function. It is not reentrant - it relies on the fact 230 * that while kdb is running on only one "master debug" cpu. 231 * Remarks: 232 * The buffer size must be >= 2. 233 */ 234 235 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("%s", 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 */ 461 462 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("%s", 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 */ 487 488 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 */ 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 } 570 571 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 } 624 625 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 } 900 901 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