1 /* 2 * Kernel Debugger Architecture Independent Console I/O handler 3 * 4 * This file is subject to the terms and conditions of the GNU General Public 5 * License. See the file "COPYING" in the main directory of this archive 6 * for more details. 7 * 8 * Copyright (c) 1999-2006 Silicon Graphics, Inc. All Rights Reserved. 9 * Copyright (c) 2009 Wind River Systems, Inc. All Rights Reserved. 10 */ 11 12 #include <linux/module.h> 13 #include <linux/types.h> 14 #include <linux/ctype.h> 15 #include <linux/kernel.h> 16 #include <linux/init.h> 17 #include <linux/kdev_t.h> 18 #include <linux/console.h> 19 #include <linux/string.h> 20 #include <linux/sched.h> 21 #include <linux/smp.h> 22 #include <linux/nmi.h> 23 #include <linux/delay.h> 24 #include <linux/kgdb.h> 25 #include <linux/kdb.h> 26 #include <linux/kallsyms.h> 27 #include "kdb_private.h" 28 29 #define CMD_BUFLEN 256 30 char kdb_prompt_str[CMD_BUFLEN]; 31 32 int kdb_trap_printk; 33 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 static int kdb_read_get_key(char *buffer, size_t bufsize) 52 { 53 #define ESCAPE_UDELAY 1000 54 #define ESCAPE_DELAY (2*1000000/ESCAPE_UDELAY) /* 2 seconds worth of udelays */ 55 char escape_data[5]; /* longest vt100 escape sequence is 4 bytes */ 56 char *ped = escape_data; 57 int escape_delay = 0; 58 get_char_func *f, *f_escape = NULL; 59 int key; 60 61 for (f = &kdb_poll_funcs[0]; ; ++f) { 62 if (*f == NULL) { 63 /* Reset NMI watchdog once per poll loop */ 64 touch_nmi_watchdog(); 65 f = &kdb_poll_funcs[0]; 66 } 67 if (escape_delay == 2) { 68 *ped = '\0'; 69 ped = escape_data; 70 --escape_delay; 71 } 72 if (escape_delay == 1) { 73 key = *ped++; 74 if (!*ped) 75 --escape_delay; 76 break; 77 } 78 key = (*f)(); 79 if (key == -1) { 80 if (escape_delay) { 81 udelay(ESCAPE_UDELAY); 82 --escape_delay; 83 } 84 continue; 85 } 86 if (bufsize <= 2) { 87 if (key == '\r') 88 key = '\n'; 89 *buffer++ = key; 90 *buffer = '\0'; 91 return -1; 92 } 93 if (escape_delay == 0 && key == '\e') { 94 escape_delay = ESCAPE_DELAY; 95 ped = escape_data; 96 f_escape = f; 97 } 98 if (escape_delay) { 99 *ped++ = key; 100 if (f_escape != f) { 101 escape_delay = 2; 102 continue; 103 } 104 if (ped - escape_data == 1) { 105 /* \e */ 106 continue; 107 } else if (ped - escape_data == 2) { 108 /* \e<something> */ 109 if (key != '[') 110 escape_delay = 2; 111 continue; 112 } else if (ped - escape_data == 3) { 113 /* \e[<something> */ 114 int mapkey = 0; 115 switch (key) { 116 case 'A': /* \e[A, up arrow */ 117 mapkey = 16; 118 break; 119 case 'B': /* \e[B, down arrow */ 120 mapkey = 14; 121 break; 122 case 'C': /* \e[C, right arrow */ 123 mapkey = 6; 124 break; 125 case 'D': /* \e[D, left arrow */ 126 mapkey = 2; 127 break; 128 case '1': /* dropthrough */ 129 case '3': /* dropthrough */ 130 /* \e[<1,3,4>], may be home, del, end */ 131 case '4': 132 mapkey = -1; 133 break; 134 } 135 if (mapkey != -1) { 136 if (mapkey > 0) { 137 escape_data[0] = mapkey; 138 escape_data[1] = '\0'; 139 } 140 escape_delay = 2; 141 } 142 continue; 143 } else if (ped - escape_data == 4) { 144 /* \e[<1,3,4><something> */ 145 int mapkey = 0; 146 if (key == '~') { 147 switch (escape_data[2]) { 148 case '1': /* \e[1~, home */ 149 mapkey = 1; 150 break; 151 case '3': /* \e[3~, del */ 152 mapkey = 4; 153 break; 154 case '4': /* \e[4~, end */ 155 mapkey = 5; 156 break; 157 } 158 } 159 if (mapkey > 0) { 160 escape_data[0] = mapkey; 161 escape_data[1] = '\0'; 162 } 163 escape_delay = 2; 164 continue; 165 } 166 } 167 break; /* A key to process */ 168 } 169 return key; 170 } 171 172 /* 173 * kdb_read 174 * 175 * This function reads a string of characters, terminated by 176 * a newline, or by reaching the end of the supplied buffer, 177 * from the current kernel debugger console device. 178 * Parameters: 179 * buffer - Address of character buffer to receive input characters. 180 * bufsize - size, in bytes, of the character buffer 181 * Returns: 182 * Returns a pointer to the buffer containing the received 183 * character string. This string will be terminated by a 184 * newline character. 185 * Locking: 186 * No locks are required to be held upon entry to this 187 * function. It is not reentrant - it relies on the fact 188 * that while kdb is running on only one "master debug" cpu. 189 * Remarks: 190 * 191 * The buffer size must be >= 2. A buffer size of 2 means that the caller only 192 * wants a single key. 193 * 194 * An escape key could be the start of a vt100 control sequence such as \e[D 195 * (left arrow) or it could be a character in its own right. The standard 196 * method for detecting the difference is to wait for 2 seconds to see if there 197 * are any other characters. kdb is complicated by the lack of a timer service 198 * (interrupts are off), by multiple input sources and by the need to sometimes 199 * return after just one key. Escape sequence processing has to be done as 200 * states in the polling loop. 201 */ 202 203 static char *kdb_read(char *buffer, size_t bufsize) 204 { 205 char *cp = buffer; 206 char *bufend = buffer+bufsize-2; /* Reserve space for newline 207 * and null byte */ 208 char *lastchar; 209 char *p_tmp; 210 char tmp; 211 static char tmpbuffer[CMD_BUFLEN]; 212 int len = strlen(buffer); 213 int len_tmp; 214 int tab = 0; 215 int count; 216 int i; 217 int diag, dtab_count; 218 int key; 219 220 221 diag = kdbgetintenv("DTABCOUNT", &dtab_count); 222 if (diag) 223 dtab_count = 30; 224 225 if (len > 0) { 226 cp += len; 227 if (*(buffer+len-1) == '\n') 228 cp--; 229 } 230 231 lastchar = cp; 232 *cp = '\0'; 233 kdb_printf("%s", buffer); 234 poll_again: 235 key = kdb_read_get_key(buffer, bufsize); 236 if (key == -1) 237 return buffer; 238 if (key != 9) 239 tab = 0; 240 switch (key) { 241 case 8: /* backspace */ 242 if (cp > buffer) { 243 if (cp < lastchar) { 244 memcpy(tmpbuffer, cp, lastchar - cp); 245 memcpy(cp-1, tmpbuffer, lastchar - cp); 246 } 247 *(--lastchar) = '\0'; 248 --cp; 249 kdb_printf("\b%s \r", cp); 250 tmp = *cp; 251 *cp = '\0'; 252 kdb_printf(kdb_prompt_str); 253 kdb_printf("%s", buffer); 254 *cp = tmp; 255 } 256 break; 257 case 13: /* enter */ 258 *lastchar++ = '\n'; 259 *lastchar++ = '\0'; 260 if (!KDB_STATE(KGDB_TRANS)) { 261 KDB_STATE_SET(KGDB_TRANS); 262 kdb_printf("%s", buffer); 263 } 264 kdb_printf("\n"); 265 return buffer; 266 case 4: /* Del */ 267 if (cp < lastchar) { 268 memcpy(tmpbuffer, cp+1, lastchar - cp - 1); 269 memcpy(cp, tmpbuffer, lastchar - cp - 1); 270 *(--lastchar) = '\0'; 271 kdb_printf("%s \r", cp); 272 tmp = *cp; 273 *cp = '\0'; 274 kdb_printf(kdb_prompt_str); 275 kdb_printf("%s", buffer); 276 *cp = tmp; 277 } 278 break; 279 case 1: /* Home */ 280 if (cp > buffer) { 281 kdb_printf("\r"); 282 kdb_printf(kdb_prompt_str); 283 cp = buffer; 284 } 285 break; 286 case 5: /* End */ 287 if (cp < lastchar) { 288 kdb_printf("%s", cp); 289 cp = lastchar; 290 } 291 break; 292 case 2: /* Left */ 293 if (cp > buffer) { 294 kdb_printf("\b"); 295 --cp; 296 } 297 break; 298 case 14: /* Down */ 299 memset(tmpbuffer, ' ', 300 strlen(kdb_prompt_str) + (lastchar-buffer)); 301 *(tmpbuffer+strlen(kdb_prompt_str) + 302 (lastchar-buffer)) = '\0'; 303 kdb_printf("\r%s\r", tmpbuffer); 304 *lastchar = (char)key; 305 *(lastchar+1) = '\0'; 306 return lastchar; 307 case 6: /* Right */ 308 if (cp < lastchar) { 309 kdb_printf("%c", *cp); 310 ++cp; 311 } 312 break; 313 case 16: /* Up */ 314 memset(tmpbuffer, ' ', 315 strlen(kdb_prompt_str) + (lastchar-buffer)); 316 *(tmpbuffer+strlen(kdb_prompt_str) + 317 (lastchar-buffer)) = '\0'; 318 kdb_printf("\r%s\r", tmpbuffer); 319 *lastchar = (char)key; 320 *(lastchar+1) = '\0'; 321 return lastchar; 322 case 9: /* Tab */ 323 if (tab < 2) 324 ++tab; 325 p_tmp = buffer; 326 while (*p_tmp == ' ') 327 p_tmp++; 328 if (p_tmp > cp) 329 break; 330 memcpy(tmpbuffer, p_tmp, cp-p_tmp); 331 *(tmpbuffer + (cp-p_tmp)) = '\0'; 332 p_tmp = strrchr(tmpbuffer, ' '); 333 if (p_tmp) 334 ++p_tmp; 335 else 336 p_tmp = tmpbuffer; 337 len = strlen(p_tmp); 338 count = kallsyms_symbol_complete(p_tmp, 339 sizeof(tmpbuffer) - 340 (p_tmp - tmpbuffer)); 341 if (tab == 2 && count > 0) { 342 kdb_printf("\n%d symbols are found.", count); 343 if (count > dtab_count) { 344 count = dtab_count; 345 kdb_printf(" But only first %d symbols will" 346 " be printed.\nYou can change the" 347 " environment variable DTABCOUNT.", 348 count); 349 } 350 kdb_printf("\n"); 351 for (i = 0; i < count; i++) { 352 if (kallsyms_symbol_next(p_tmp, i) < 0) 353 break; 354 kdb_printf("%s ", p_tmp); 355 *(p_tmp + len) = '\0'; 356 } 357 if (i >= dtab_count) 358 kdb_printf("..."); 359 kdb_printf("\n"); 360 kdb_printf(kdb_prompt_str); 361 kdb_printf("%s", buffer); 362 } else if (tab != 2 && count > 0) { 363 len_tmp = strlen(p_tmp); 364 strncpy(p_tmp+len_tmp, cp, lastchar-cp+1); 365 len_tmp = strlen(p_tmp); 366 strncpy(cp, p_tmp+len, len_tmp-len + 1); 367 len = len_tmp - len; 368 kdb_printf("%s", cp); 369 cp += len; 370 lastchar += len; 371 } 372 kdb_nextline = 1; /* reset output line number */ 373 break; 374 default: 375 if (key >= 32 && lastchar < bufend) { 376 if (cp < lastchar) { 377 memcpy(tmpbuffer, cp, lastchar - cp); 378 memcpy(cp+1, tmpbuffer, lastchar - cp); 379 *++lastchar = '\0'; 380 *cp = key; 381 kdb_printf("%s\r", cp); 382 ++cp; 383 tmp = *cp; 384 *cp = '\0'; 385 kdb_printf(kdb_prompt_str); 386 kdb_printf("%s", buffer); 387 *cp = tmp; 388 } else { 389 *++lastchar = '\0'; 390 *cp++ = key; 391 /* The kgdb transition check will hide 392 * printed characters if we think that 393 * kgdb is connecting, until the check 394 * fails */ 395 if (!KDB_STATE(KGDB_TRANS)) { 396 if (kgdb_transition_check(buffer)) 397 return buffer; 398 } else { 399 kdb_printf("%c", key); 400 } 401 } 402 /* Special escape to kgdb */ 403 if (lastchar - buffer >= 5 && 404 strcmp(lastchar - 5, "$?#3f") == 0) { 405 kdb_gdb_state_pass(lastchar - 5); 406 strcpy(buffer, "kgdb"); 407 KDB_STATE_SET(DOING_KGDB); 408 return buffer; 409 } 410 if (lastchar - buffer >= 11 && 411 strcmp(lastchar - 11, "$qSupported") == 0) { 412 kdb_gdb_state_pass(lastchar - 11); 413 strcpy(buffer, "kgdb"); 414 KDB_STATE_SET(DOING_KGDB); 415 return buffer; 416 } 417 } 418 break; 419 } 420 goto poll_again; 421 } 422 423 /* 424 * kdb_getstr 425 * 426 * Print the prompt string and read a command from the 427 * input device. 428 * 429 * Parameters: 430 * buffer Address of buffer to receive command 431 * bufsize Size of buffer in bytes 432 * prompt Pointer to string to use as prompt string 433 * Returns: 434 * Pointer to command buffer. 435 * Locking: 436 * None. 437 * Remarks: 438 * For SMP kernels, the processor number will be 439 * substituted for %d, %x or %o in the prompt. 440 */ 441 442 char *kdb_getstr(char *buffer, size_t bufsize, const char *prompt) 443 { 444 if (prompt && kdb_prompt_str != prompt) 445 strncpy(kdb_prompt_str, prompt, CMD_BUFLEN); 446 kdb_printf(kdb_prompt_str); 447 kdb_nextline = 1; /* Prompt and input resets line number */ 448 return kdb_read(buffer, bufsize); 449 } 450 451 /* 452 * kdb_input_flush 453 * 454 * Get rid of any buffered console input. 455 * 456 * Parameters: 457 * none 458 * Returns: 459 * nothing 460 * Locking: 461 * none 462 * Remarks: 463 * Call this function whenever you want to flush input. If there is any 464 * outstanding input, it ignores all characters until there has been no 465 * data for approximately 1ms. 466 */ 467 468 static void kdb_input_flush(void) 469 { 470 get_char_func *f; 471 int res; 472 int flush_delay = 1; 473 while (flush_delay) { 474 flush_delay--; 475 empty: 476 touch_nmi_watchdog(); 477 for (f = &kdb_poll_funcs[0]; *f; ++f) { 478 res = (*f)(); 479 if (res != -1) { 480 flush_delay = 1; 481 goto empty; 482 } 483 } 484 if (flush_delay) 485 mdelay(1); 486 } 487 } 488 489 /* 490 * kdb_printf 491 * 492 * Print a string to the output device(s). 493 * 494 * Parameters: 495 * printf-like format and optional args. 496 * Returns: 497 * 0 498 * Locking: 499 * None. 500 * Remarks: 501 * use 'kdbcons->write()' to avoid polluting 'log_buf' with 502 * kdb output. 503 * 504 * If the user is doing a cmd args | grep srch 505 * then kdb_grepping_flag is set. 506 * In that case we need to accumulate full lines (ending in \n) before 507 * searching for the pattern. 508 */ 509 510 static char kdb_buffer[256]; /* A bit too big to go on stack */ 511 static char *next_avail = kdb_buffer; 512 static int size_avail; 513 static int suspend_grep; 514 515 /* 516 * search arg1 to see if it contains arg2 517 * (kdmain.c provides flags for ^pat and pat$) 518 * 519 * return 1 for found, 0 for not found 520 */ 521 static int kdb_search_string(char *searched, char *searchfor) 522 { 523 char firstchar, *cp; 524 int len1, len2; 525 526 /* not counting the newline at the end of "searched" */ 527 len1 = strlen(searched)-1; 528 len2 = strlen(searchfor); 529 if (len1 < len2) 530 return 0; 531 if (kdb_grep_leading && kdb_grep_trailing && len1 != len2) 532 return 0; 533 if (kdb_grep_leading) { 534 if (!strncmp(searched, searchfor, len2)) 535 return 1; 536 } else if (kdb_grep_trailing) { 537 if (!strncmp(searched+len1-len2, searchfor, len2)) 538 return 1; 539 } else { 540 firstchar = *searchfor; 541 cp = searched; 542 while ((cp = strchr(cp, firstchar))) { 543 if (!strncmp(cp, searchfor, len2)) 544 return 1; 545 cp++; 546 } 547 } 548 return 0; 549 } 550 551 int vkdb_printf(enum kdb_msgsrc src, const char *fmt, va_list ap) 552 { 553 int diag; 554 int linecount; 555 int colcount; 556 int logging, saved_loglevel = 0; 557 int saved_trap_printk; 558 int got_printf_lock = 0; 559 int retlen = 0; 560 int fnd, len; 561 char *cp, *cp2, *cphold = NULL, replaced_byte = ' '; 562 char *moreprompt = "more> "; 563 struct console *c = console_drivers; 564 static DEFINE_SPINLOCK(kdb_printf_lock); 565 unsigned long uninitialized_var(flags); 566 567 preempt_disable(); 568 saved_trap_printk = kdb_trap_printk; 569 kdb_trap_printk = 0; 570 571 /* Serialize kdb_printf if multiple cpus try to write at once. 572 * But if any cpu goes recursive in kdb, just print the output, 573 * even if it is interleaved with any other text. 574 */ 575 if (!KDB_STATE(PRINTF_LOCK)) { 576 KDB_STATE_SET(PRINTF_LOCK); 577 spin_lock_irqsave(&kdb_printf_lock, flags); 578 got_printf_lock = 1; 579 atomic_inc(&kdb_event); 580 } else { 581 __acquire(kdb_printf_lock); 582 } 583 584 diag = kdbgetintenv("LINES", &linecount); 585 if (diag || linecount <= 1) 586 linecount = 24; 587 588 diag = kdbgetintenv("COLUMNS", &colcount); 589 if (diag || colcount <= 1) 590 colcount = 80; 591 592 diag = kdbgetintenv("LOGGING", &logging); 593 if (diag) 594 logging = 0; 595 596 if (!kdb_grepping_flag || suspend_grep) { 597 /* normally, every vsnprintf starts a new buffer */ 598 next_avail = kdb_buffer; 599 size_avail = sizeof(kdb_buffer); 600 } 601 vsnprintf(next_avail, size_avail, fmt, ap); 602 603 /* 604 * If kdb_parse() found that the command was cmd xxx | grep yyy 605 * then kdb_grepping_flag is set, and kdb_grep_string contains yyy 606 * 607 * Accumulate the print data up to a newline before searching it. 608 * (vsnprintf does null-terminate the string that it generates) 609 */ 610 611 /* skip the search if prints are temporarily unconditional */ 612 if (!suspend_grep && kdb_grepping_flag) { 613 cp = strchr(kdb_buffer, '\n'); 614 if (!cp) { 615 /* 616 * Special cases that don't end with newlines 617 * but should be written without one: 618 * The "[nn]kdb> " prompt should 619 * appear at the front of the buffer. 620 * 621 * The "[nn]more " prompt should also be 622 * (MOREPROMPT -> moreprompt) 623 * written * but we print that ourselves, 624 * we set the suspend_grep flag to make 625 * it unconditional. 626 * 627 */ 628 if (next_avail == kdb_buffer) { 629 /* 630 * these should occur after a newline, 631 * so they will be at the front of the 632 * buffer 633 */ 634 cp2 = kdb_buffer; 635 len = strlen(kdb_prompt_str); 636 if (!strncmp(cp2, kdb_prompt_str, len)) { 637 /* 638 * We're about to start a new 639 * command, so we can go back 640 * to normal mode. 641 */ 642 kdb_grepping_flag = 0; 643 goto kdb_printit; 644 } 645 } 646 /* no newline; don't search/write the buffer 647 until one is there */ 648 len = strlen(kdb_buffer); 649 next_avail = kdb_buffer + len; 650 size_avail = sizeof(kdb_buffer) - len; 651 goto kdb_print_out; 652 } 653 654 /* 655 * The newline is present; print through it or discard 656 * it, depending on the results of the search. 657 */ 658 cp++; /* to byte after the newline */ 659 replaced_byte = *cp; /* remember what/where it was */ 660 cphold = cp; 661 *cp = '\0'; /* end the string for our search */ 662 663 /* 664 * We now have a newline at the end of the string 665 * Only continue with this output if it contains the 666 * search string. 667 */ 668 fnd = kdb_search_string(kdb_buffer, kdb_grep_string); 669 if (!fnd) { 670 /* 671 * At this point the complete line at the start 672 * of kdb_buffer can be discarded, as it does 673 * not contain what the user is looking for. 674 * Shift the buffer left. 675 */ 676 *cphold = replaced_byte; 677 strcpy(kdb_buffer, cphold); 678 len = strlen(kdb_buffer); 679 next_avail = kdb_buffer + len; 680 size_avail = sizeof(kdb_buffer) - len; 681 goto kdb_print_out; 682 } 683 if (kdb_grepping_flag >= KDB_GREPPING_FLAG_SEARCH) 684 /* 685 * This was a interactive search (using '/' at more 686 * prompt) and it has completed. Clear the flag. 687 */ 688 kdb_grepping_flag = 0; 689 /* 690 * at this point the string is a full line and 691 * should be printed, up to the null. 692 */ 693 } 694 kdb_printit: 695 696 /* 697 * Write to all consoles. 698 */ 699 retlen = strlen(kdb_buffer); 700 cp = (char *) printk_skip_level(kdb_buffer); 701 if (!dbg_kdb_mode && kgdb_connected) { 702 gdbstub_msg_write(cp, retlen - (cp - kdb_buffer)); 703 } else { 704 if (dbg_io_ops && !dbg_io_ops->is_console) { 705 len = retlen - (cp - kdb_buffer); 706 cp2 = cp; 707 while (len--) { 708 dbg_io_ops->write_char(*cp2); 709 cp2++; 710 } 711 } 712 while (c) { 713 c->write(c, cp, retlen - (cp - kdb_buffer)); 714 touch_nmi_watchdog(); 715 c = c->next; 716 } 717 } 718 if (logging) { 719 saved_loglevel = console_loglevel; 720 console_loglevel = CONSOLE_LOGLEVEL_SILENT; 721 if (printk_get_level(kdb_buffer) || src == KDB_MSGSRC_PRINTK) 722 printk("%s", kdb_buffer); 723 else 724 pr_info("%s", kdb_buffer); 725 } 726 727 if (KDB_STATE(PAGER)) { 728 /* 729 * Check printed string to decide how to bump the 730 * kdb_nextline to control when the more prompt should 731 * show up. 732 */ 733 int got = 0; 734 len = retlen; 735 while (len--) { 736 if (kdb_buffer[len] == '\n') { 737 kdb_nextline++; 738 got = 0; 739 } else if (kdb_buffer[len] == '\r') { 740 got = 0; 741 } else { 742 got++; 743 } 744 } 745 kdb_nextline += got / (colcount + 1); 746 } 747 748 /* check for having reached the LINES number of printed lines */ 749 if (kdb_nextline >= linecount) { 750 char buf1[16] = ""; 751 752 /* Watch out for recursion here. Any routine that calls 753 * kdb_printf will come back through here. And kdb_read 754 * uses kdb_printf to echo on serial consoles ... 755 */ 756 kdb_nextline = 1; /* In case of recursion */ 757 758 /* 759 * Pause until cr. 760 */ 761 moreprompt = kdbgetenv("MOREPROMPT"); 762 if (moreprompt == NULL) 763 moreprompt = "more> "; 764 765 kdb_input_flush(); 766 c = console_drivers; 767 768 if (dbg_io_ops && !dbg_io_ops->is_console) { 769 len = strlen(moreprompt); 770 cp = moreprompt; 771 while (len--) { 772 dbg_io_ops->write_char(*cp); 773 cp++; 774 } 775 } 776 while (c) { 777 c->write(c, moreprompt, strlen(moreprompt)); 778 touch_nmi_watchdog(); 779 c = c->next; 780 } 781 782 if (logging) 783 printk("%s", moreprompt); 784 785 kdb_read(buf1, 2); /* '2' indicates to return 786 * immediately after getting one key. */ 787 kdb_nextline = 1; /* Really set output line 1 */ 788 789 /* empty and reset the buffer: */ 790 kdb_buffer[0] = '\0'; 791 next_avail = kdb_buffer; 792 size_avail = sizeof(kdb_buffer); 793 if ((buf1[0] == 'q') || (buf1[0] == 'Q')) { 794 /* user hit q or Q */ 795 KDB_FLAG_SET(CMD_INTERRUPT); /* command interrupted */ 796 KDB_STATE_CLEAR(PAGER); 797 /* end of command output; back to normal mode */ 798 kdb_grepping_flag = 0; 799 kdb_printf("\n"); 800 } else if (buf1[0] == ' ') { 801 kdb_printf("\r"); 802 suspend_grep = 1; /* for this recursion */ 803 } else if (buf1[0] == '\n') { 804 kdb_nextline = linecount - 1; 805 kdb_printf("\r"); 806 suspend_grep = 1; /* for this recursion */ 807 } else if (buf1[0] == '/' && !kdb_grepping_flag) { 808 kdb_printf("\r"); 809 kdb_getstr(kdb_grep_string, KDB_GREP_STRLEN, 810 kdbgetenv("SEARCHPROMPT") ?: "search> "); 811 *strchrnul(kdb_grep_string, '\n') = '\0'; 812 kdb_grepping_flag += KDB_GREPPING_FLAG_SEARCH; 813 suspend_grep = 1; /* for this recursion */ 814 } else if (buf1[0] && buf1[0] != '\n') { 815 /* user hit something other than enter */ 816 suspend_grep = 1; /* for this recursion */ 817 if (buf1[0] != '/') 818 kdb_printf( 819 "\nOnly 'q', 'Q' or '/' are processed at " 820 "more prompt, input ignored\n"); 821 else 822 kdb_printf("\n'/' cannot be used during | " 823 "grep filtering, input ignored\n"); 824 } else if (kdb_grepping_flag) { 825 /* user hit enter */ 826 suspend_grep = 1; /* for this recursion */ 827 kdb_printf("\n"); 828 } 829 kdb_input_flush(); 830 } 831 832 /* 833 * For grep searches, shift the printed string left. 834 * replaced_byte contains the character that was overwritten with 835 * the terminating null, and cphold points to the null. 836 * Then adjust the notion of available space in the buffer. 837 */ 838 if (kdb_grepping_flag && !suspend_grep) { 839 *cphold = replaced_byte; 840 strcpy(kdb_buffer, cphold); 841 len = strlen(kdb_buffer); 842 next_avail = kdb_buffer + len; 843 size_avail = sizeof(kdb_buffer) - len; 844 } 845 846 kdb_print_out: 847 suspend_grep = 0; /* end of what may have been a recursive call */ 848 if (logging) 849 console_loglevel = saved_loglevel; 850 if (KDB_STATE(PRINTF_LOCK) && got_printf_lock) { 851 got_printf_lock = 0; 852 spin_unlock_irqrestore(&kdb_printf_lock, flags); 853 KDB_STATE_CLEAR(PRINTF_LOCK); 854 atomic_dec(&kdb_event); 855 } else { 856 __release(kdb_printf_lock); 857 } 858 kdb_trap_printk = saved_trap_printk; 859 preempt_enable(); 860 return retlen; 861 } 862 863 int kdb_printf(const char *fmt, ...) 864 { 865 va_list ap; 866 int r; 867 868 va_start(ap, fmt); 869 r = vkdb_printf(KDB_MSGSRC_INTERNAL, fmt, ap); 870 va_end(ap); 871 872 return r; 873 } 874 EXPORT_SYMBOL_GPL(kdb_printf); 875