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; 134 135 for (f = &kdb_poll_funcs[0]; ; ++f) { 136 if (*f == NULL) { 137 /* Reset NMI watchdog once per poll loop */ 138 touch_nmi_watchdog(); 139 f = &kdb_poll_funcs[0]; 140 } 141 142 key = (*f)(); 143 if (key == -1) { 144 if (escape_delay) { 145 udelay(ESCAPE_UDELAY); 146 if (--escape_delay == 0) 147 return '\e'; 148 } 149 continue; 150 } 151 152 /* 153 * When the first character is received (or we get a change 154 * input source) we set ourselves up to handle an escape 155 * sequences (just in case). 156 */ 157 if (f_prev != f) { 158 f_prev = f; 159 pbuf = buf; 160 escape_delay = ESCAPE_DELAY; 161 } 162 163 *pbuf++ = key; 164 key = kdb_handle_escape(buf, pbuf - buf); 165 if (key < 0) /* no escape sequence; return best character */ 166 return buf[pbuf - buf == 2 ? 1 : 0]; 167 if (key > 0) 168 return key; 169 } 170 171 unreachable(); 172 } 173 174 /* 175 * kdb_read 176 * 177 * This function reads a string of characters, terminated by 178 * a newline, or by reaching the end of the supplied buffer, 179 * from the current kernel debugger console device. 180 * Parameters: 181 * buffer - Address of character buffer to receive input characters. 182 * bufsize - size, in bytes, of the character buffer 183 * Returns: 184 * Returns a pointer to the buffer containing the received 185 * character string. This string will be terminated by a 186 * newline character. 187 * Locking: 188 * No locks are required to be held upon entry to this 189 * function. It is not reentrant - it relies on the fact 190 * that while kdb is running on only one "master debug" cpu. 191 * Remarks: 192 * The buffer size must be >= 2. 193 */ 194 195 static char *kdb_read(char *buffer, size_t bufsize) 196 { 197 char *cp = buffer; 198 char *bufend = buffer+bufsize-2; /* Reserve space for newline 199 * and null byte */ 200 char *lastchar; 201 char *p_tmp; 202 char tmp; 203 static char tmpbuffer[CMD_BUFLEN]; 204 int len = strlen(buffer); 205 int len_tmp; 206 int tab = 0; 207 int count; 208 int i; 209 int diag, dtab_count; 210 int key, buf_size, ret; 211 212 213 diag = kdbgetintenv("DTABCOUNT", &dtab_count); 214 if (diag) 215 dtab_count = 30; 216 217 if (len > 0) { 218 cp += len; 219 if (*(buffer+len-1) == '\n') 220 cp--; 221 } 222 223 lastchar = cp; 224 *cp = '\0'; 225 kdb_printf("%s", buffer); 226 poll_again: 227 key = kdb_getchar(); 228 if (key != 9) 229 tab = 0; 230 switch (key) { 231 case 8: /* backspace */ 232 if (cp > buffer) { 233 if (cp < lastchar) { 234 memcpy(tmpbuffer, cp, lastchar - cp); 235 memcpy(cp-1, tmpbuffer, lastchar - cp); 236 } 237 *(--lastchar) = '\0'; 238 --cp; 239 kdb_printf("\b%s \r", cp); 240 tmp = *cp; 241 *cp = '\0'; 242 kdb_printf(kdb_prompt_str); 243 kdb_printf("%s", buffer); 244 *cp = tmp; 245 } 246 break; 247 case 13: /* enter */ 248 *lastchar++ = '\n'; 249 *lastchar++ = '\0'; 250 if (!KDB_STATE(KGDB_TRANS)) { 251 KDB_STATE_SET(KGDB_TRANS); 252 kdb_printf("%s", buffer); 253 } 254 kdb_printf("\n"); 255 return buffer; 256 case 4: /* Del */ 257 if (cp < lastchar) { 258 memcpy(tmpbuffer, cp+1, lastchar - cp - 1); 259 memcpy(cp, tmpbuffer, lastchar - cp - 1); 260 *(--lastchar) = '\0'; 261 kdb_printf("%s \r", cp); 262 tmp = *cp; 263 *cp = '\0'; 264 kdb_printf(kdb_prompt_str); 265 kdb_printf("%s", buffer); 266 *cp = tmp; 267 } 268 break; 269 case 1: /* Home */ 270 if (cp > buffer) { 271 kdb_printf("\r"); 272 kdb_printf(kdb_prompt_str); 273 cp = buffer; 274 } 275 break; 276 case 5: /* End */ 277 if (cp < lastchar) { 278 kdb_printf("%s", cp); 279 cp = lastchar; 280 } 281 break; 282 case 2: /* Left */ 283 if (cp > buffer) { 284 kdb_printf("\b"); 285 --cp; 286 } 287 break; 288 case 14: /* Down */ 289 memset(tmpbuffer, ' ', 290 strlen(kdb_prompt_str) + (lastchar-buffer)); 291 *(tmpbuffer+strlen(kdb_prompt_str) + 292 (lastchar-buffer)) = '\0'; 293 kdb_printf("\r%s\r", tmpbuffer); 294 *lastchar = (char)key; 295 *(lastchar+1) = '\0'; 296 return lastchar; 297 case 6: /* Right */ 298 if (cp < lastchar) { 299 kdb_printf("%c", *cp); 300 ++cp; 301 } 302 break; 303 case 16: /* Up */ 304 memset(tmpbuffer, ' ', 305 strlen(kdb_prompt_str) + (lastchar-buffer)); 306 *(tmpbuffer+strlen(kdb_prompt_str) + 307 (lastchar-buffer)) = '\0'; 308 kdb_printf("\r%s\r", tmpbuffer); 309 *lastchar = (char)key; 310 *(lastchar+1) = '\0'; 311 return lastchar; 312 case 9: /* Tab */ 313 if (tab < 2) 314 ++tab; 315 p_tmp = buffer; 316 while (*p_tmp == ' ') 317 p_tmp++; 318 if (p_tmp > cp) 319 break; 320 memcpy(tmpbuffer, p_tmp, cp-p_tmp); 321 *(tmpbuffer + (cp-p_tmp)) = '\0'; 322 p_tmp = strrchr(tmpbuffer, ' '); 323 if (p_tmp) 324 ++p_tmp; 325 else 326 p_tmp = tmpbuffer; 327 len = strlen(p_tmp); 328 buf_size = sizeof(tmpbuffer) - (p_tmp - tmpbuffer); 329 count = kallsyms_symbol_complete(p_tmp, buf_size); 330 if (tab == 2 && count > 0) { 331 kdb_printf("\n%d symbols are found.", count); 332 if (count > dtab_count) { 333 count = dtab_count; 334 kdb_printf(" But only first %d symbols will" 335 " be printed.\nYou can change the" 336 " environment variable DTABCOUNT.", 337 count); 338 } 339 kdb_printf("\n"); 340 for (i = 0; i < count; i++) { 341 ret = kallsyms_symbol_next(p_tmp, i, buf_size); 342 if (WARN_ON(!ret)) 343 break; 344 if (ret != -E2BIG) 345 kdb_printf("%s ", p_tmp); 346 else 347 kdb_printf("%s... ", p_tmp); 348 *(p_tmp + len) = '\0'; 349 } 350 if (i >= dtab_count) 351 kdb_printf("..."); 352 kdb_printf("\n"); 353 kdb_printf(kdb_prompt_str); 354 kdb_printf("%s", buffer); 355 } else if (tab != 2 && count > 0) { 356 len_tmp = strlen(p_tmp); 357 strncpy(p_tmp+len_tmp, cp, lastchar-cp+1); 358 len_tmp = strlen(p_tmp); 359 strncpy(cp, p_tmp+len, len_tmp-len + 1); 360 len = len_tmp - len; 361 kdb_printf("%s", cp); 362 cp += len; 363 lastchar += len; 364 } 365 kdb_nextline = 1; /* reset output line number */ 366 break; 367 default: 368 if (key >= 32 && lastchar < bufend) { 369 if (cp < lastchar) { 370 memcpy(tmpbuffer, cp, lastchar - cp); 371 memcpy(cp+1, tmpbuffer, lastchar - cp); 372 *++lastchar = '\0'; 373 *cp = key; 374 kdb_printf("%s\r", cp); 375 ++cp; 376 tmp = *cp; 377 *cp = '\0'; 378 kdb_printf(kdb_prompt_str); 379 kdb_printf("%s", buffer); 380 *cp = tmp; 381 } else { 382 *++lastchar = '\0'; 383 *cp++ = key; 384 /* The kgdb transition check will hide 385 * printed characters if we think that 386 * kgdb is connecting, until the check 387 * fails */ 388 if (!KDB_STATE(KGDB_TRANS)) { 389 if (kgdb_transition_check(buffer)) 390 return buffer; 391 } else { 392 kdb_printf("%c", key); 393 } 394 } 395 /* Special escape to kgdb */ 396 if (lastchar - buffer >= 5 && 397 strcmp(lastchar - 5, "$?#3f") == 0) { 398 kdb_gdb_state_pass(lastchar - 5); 399 strcpy(buffer, "kgdb"); 400 KDB_STATE_SET(DOING_KGDB); 401 return buffer; 402 } 403 if (lastchar - buffer >= 11 && 404 strcmp(lastchar - 11, "$qSupported") == 0) { 405 kdb_gdb_state_pass(lastchar - 11); 406 strcpy(buffer, "kgdb"); 407 KDB_STATE_SET(DOING_KGDB); 408 return buffer; 409 } 410 } 411 break; 412 } 413 goto poll_again; 414 } 415 416 /* 417 * kdb_getstr 418 * 419 * Print the prompt string and read a command from the 420 * input device. 421 * 422 * Parameters: 423 * buffer Address of buffer to receive command 424 * bufsize Size of buffer in bytes 425 * prompt Pointer to string to use as prompt string 426 * Returns: 427 * Pointer to command buffer. 428 * Locking: 429 * None. 430 * Remarks: 431 * For SMP kernels, the processor number will be 432 * substituted for %d, %x or %o in the prompt. 433 */ 434 435 char *kdb_getstr(char *buffer, size_t bufsize, const char *prompt) 436 { 437 if (prompt && kdb_prompt_str != prompt) 438 strscpy(kdb_prompt_str, prompt, CMD_BUFLEN); 439 kdb_printf(kdb_prompt_str); 440 kdb_nextline = 1; /* Prompt and input resets line number */ 441 return kdb_read(buffer, bufsize); 442 } 443 444 /* 445 * kdb_input_flush 446 * 447 * Get rid of any buffered console input. 448 * 449 * Parameters: 450 * none 451 * Returns: 452 * nothing 453 * Locking: 454 * none 455 * Remarks: 456 * Call this function whenever you want to flush input. If there is any 457 * outstanding input, it ignores all characters until there has been no 458 * data for approximately 1ms. 459 */ 460 461 static void kdb_input_flush(void) 462 { 463 get_char_func *f; 464 int res; 465 int flush_delay = 1; 466 while (flush_delay) { 467 flush_delay--; 468 empty: 469 touch_nmi_watchdog(); 470 for (f = &kdb_poll_funcs[0]; *f; ++f) { 471 res = (*f)(); 472 if (res != -1) { 473 flush_delay = 1; 474 goto empty; 475 } 476 } 477 if (flush_delay) 478 mdelay(1); 479 } 480 } 481 482 /* 483 * kdb_printf 484 * 485 * Print a string to the output device(s). 486 * 487 * Parameters: 488 * printf-like format and optional args. 489 * Returns: 490 * 0 491 * Locking: 492 * None. 493 * Remarks: 494 * use 'kdbcons->write()' to avoid polluting 'log_buf' with 495 * kdb output. 496 * 497 * If the user is doing a cmd args | grep srch 498 * then kdb_grepping_flag is set. 499 * In that case we need to accumulate full lines (ending in \n) before 500 * searching for the pattern. 501 */ 502 503 static char kdb_buffer[256]; /* A bit too big to go on stack */ 504 static char *next_avail = kdb_buffer; 505 static int size_avail; 506 static int suspend_grep; 507 508 /* 509 * search arg1 to see if it contains arg2 510 * (kdmain.c provides flags for ^pat and pat$) 511 * 512 * return 1 for found, 0 for not found 513 */ 514 static int kdb_search_string(char *searched, char *searchfor) 515 { 516 char firstchar, *cp; 517 int len1, len2; 518 519 /* not counting the newline at the end of "searched" */ 520 len1 = strlen(searched)-1; 521 len2 = strlen(searchfor); 522 if (len1 < len2) 523 return 0; 524 if (kdb_grep_leading && kdb_grep_trailing && len1 != len2) 525 return 0; 526 if (kdb_grep_leading) { 527 if (!strncmp(searched, searchfor, len2)) 528 return 1; 529 } else if (kdb_grep_trailing) { 530 if (!strncmp(searched+len1-len2, searchfor, len2)) 531 return 1; 532 } else { 533 firstchar = *searchfor; 534 cp = searched; 535 while ((cp = strchr(cp, firstchar))) { 536 if (!strncmp(cp, searchfor, len2)) 537 return 1; 538 cp++; 539 } 540 } 541 return 0; 542 } 543 544 static void kdb_msg_write(const char *msg, int msg_len) 545 { 546 struct console *c; 547 const char *cp; 548 int len; 549 550 if (msg_len == 0) 551 return; 552 553 cp = msg; 554 len = msg_len; 555 556 while (len--) { 557 dbg_io_ops->write_char(*cp); 558 cp++; 559 } 560 561 for_each_console(c) { 562 if (!(c->flags & CON_ENABLED)) 563 continue; 564 if (c == dbg_io_ops->cons) 565 continue; 566 /* 567 * Set oops_in_progress to encourage the console drivers to 568 * disregard their internal spin locks: in the current calling 569 * context the risk of deadlock is a bigger problem than risks 570 * due to re-entering the console driver. We operate directly on 571 * oops_in_progress rather than using bust_spinlocks() because 572 * the calls bust_spinlocks() makes on exit are not appropriate 573 * for this calling context. 574 */ 575 ++oops_in_progress; 576 c->write(c, msg, msg_len); 577 --oops_in_progress; 578 touch_nmi_watchdog(); 579 } 580 } 581 582 int vkdb_printf(enum kdb_msgsrc src, const char *fmt, va_list ap) 583 { 584 int diag; 585 int linecount; 586 int colcount; 587 int logging, saved_loglevel = 0; 588 int retlen = 0; 589 int fnd, len; 590 int this_cpu, old_cpu; 591 char *cp, *cp2, *cphold = NULL, replaced_byte = ' '; 592 char *moreprompt = "more> "; 593 unsigned long flags; 594 595 /* Serialize kdb_printf if multiple cpus try to write at once. 596 * But if any cpu goes recursive in kdb, just print the output, 597 * even if it is interleaved with any other text. 598 */ 599 local_irq_save(flags); 600 this_cpu = smp_processor_id(); 601 for (;;) { 602 old_cpu = cmpxchg(&kdb_printf_cpu, -1, this_cpu); 603 if (old_cpu == -1 || old_cpu == this_cpu) 604 break; 605 606 cpu_relax(); 607 } 608 609 diag = kdbgetintenv("LINES", &linecount); 610 if (diag || linecount <= 1) 611 linecount = 24; 612 613 diag = kdbgetintenv("COLUMNS", &colcount); 614 if (diag || colcount <= 1) 615 colcount = 80; 616 617 diag = kdbgetintenv("LOGGING", &logging); 618 if (diag) 619 logging = 0; 620 621 if (!kdb_grepping_flag || suspend_grep) { 622 /* normally, every vsnprintf starts a new buffer */ 623 next_avail = kdb_buffer; 624 size_avail = sizeof(kdb_buffer); 625 } 626 vsnprintf(next_avail, size_avail, fmt, ap); 627 628 /* 629 * If kdb_parse() found that the command was cmd xxx | grep yyy 630 * then kdb_grepping_flag is set, and kdb_grep_string contains yyy 631 * 632 * Accumulate the print data up to a newline before searching it. 633 * (vsnprintf does null-terminate the string that it generates) 634 */ 635 636 /* skip the search if prints are temporarily unconditional */ 637 if (!suspend_grep && kdb_grepping_flag) { 638 cp = strchr(kdb_buffer, '\n'); 639 if (!cp) { 640 /* 641 * Special cases that don't end with newlines 642 * but should be written without one: 643 * The "[nn]kdb> " prompt should 644 * appear at the front of the buffer. 645 * 646 * The "[nn]more " prompt should also be 647 * (MOREPROMPT -> moreprompt) 648 * written * but we print that ourselves, 649 * we set the suspend_grep flag to make 650 * it unconditional. 651 * 652 */ 653 if (next_avail == kdb_buffer) { 654 /* 655 * these should occur after a newline, 656 * so they will be at the front of the 657 * buffer 658 */ 659 cp2 = kdb_buffer; 660 len = strlen(kdb_prompt_str); 661 if (!strncmp(cp2, kdb_prompt_str, len)) { 662 /* 663 * We're about to start a new 664 * command, so we can go back 665 * to normal mode. 666 */ 667 kdb_grepping_flag = 0; 668 goto kdb_printit; 669 } 670 } 671 /* no newline; don't search/write the buffer 672 until one is there */ 673 len = strlen(kdb_buffer); 674 next_avail = kdb_buffer + len; 675 size_avail = sizeof(kdb_buffer) - len; 676 goto kdb_print_out; 677 } 678 679 /* 680 * The newline is present; print through it or discard 681 * it, depending on the results of the search. 682 */ 683 cp++; /* to byte after the newline */ 684 replaced_byte = *cp; /* remember what/where it was */ 685 cphold = cp; 686 *cp = '\0'; /* end the string for our search */ 687 688 /* 689 * We now have a newline at the end of the string 690 * Only continue with this output if it contains the 691 * search string. 692 */ 693 fnd = kdb_search_string(kdb_buffer, kdb_grep_string); 694 if (!fnd) { 695 /* 696 * At this point the complete line at the start 697 * of kdb_buffer can be discarded, as it does 698 * not contain what the user is looking for. 699 * Shift the buffer left. 700 */ 701 *cphold = replaced_byte; 702 strcpy(kdb_buffer, cphold); 703 len = strlen(kdb_buffer); 704 next_avail = kdb_buffer + len; 705 size_avail = sizeof(kdb_buffer) - len; 706 goto kdb_print_out; 707 } 708 if (kdb_grepping_flag >= KDB_GREPPING_FLAG_SEARCH) { 709 /* 710 * This was a interactive search (using '/' at more 711 * prompt) and it has completed. Replace the \0 with 712 * its original value to ensure multi-line strings 713 * are handled properly, and return to normal mode. 714 */ 715 *cphold = replaced_byte; 716 kdb_grepping_flag = 0; 717 } 718 /* 719 * at this point the string is a full line and 720 * should be printed, up to the null. 721 */ 722 } 723 kdb_printit: 724 725 /* 726 * Write to all consoles. 727 */ 728 retlen = strlen(kdb_buffer); 729 cp = (char *) printk_skip_headers(kdb_buffer); 730 if (!dbg_kdb_mode && kgdb_connected) 731 gdbstub_msg_write(cp, retlen - (cp - kdb_buffer)); 732 else 733 kdb_msg_write(cp, retlen - (cp - kdb_buffer)); 734 735 if (logging) { 736 saved_loglevel = console_loglevel; 737 console_loglevel = CONSOLE_LOGLEVEL_SILENT; 738 if (printk_get_level(kdb_buffer) || src == KDB_MSGSRC_PRINTK) 739 printk("%s", kdb_buffer); 740 else 741 pr_info("%s", kdb_buffer); 742 } 743 744 if (KDB_STATE(PAGER)) { 745 /* 746 * Check printed string to decide how to bump the 747 * kdb_nextline to control when the more prompt should 748 * show up. 749 */ 750 int got = 0; 751 len = retlen; 752 while (len--) { 753 if (kdb_buffer[len] == '\n') { 754 kdb_nextline++; 755 got = 0; 756 } else if (kdb_buffer[len] == '\r') { 757 got = 0; 758 } else { 759 got++; 760 } 761 } 762 kdb_nextline += got / (colcount + 1); 763 } 764 765 /* check for having reached the LINES number of printed lines */ 766 if (kdb_nextline >= linecount) { 767 char ch; 768 769 /* Watch out for recursion here. Any routine that calls 770 * kdb_printf will come back through here. And kdb_read 771 * uses kdb_printf to echo on serial consoles ... 772 */ 773 kdb_nextline = 1; /* In case of recursion */ 774 775 /* 776 * Pause until cr. 777 */ 778 moreprompt = kdbgetenv("MOREPROMPT"); 779 if (moreprompt == NULL) 780 moreprompt = "more> "; 781 782 kdb_input_flush(); 783 kdb_msg_write(moreprompt, strlen(moreprompt)); 784 785 if (logging) 786 printk("%s", moreprompt); 787 788 ch = kdb_getchar(); 789 kdb_nextline = 1; /* Really set output line 1 */ 790 791 /* empty and reset the buffer: */ 792 kdb_buffer[0] = '\0'; 793 next_avail = kdb_buffer; 794 size_avail = sizeof(kdb_buffer); 795 if ((ch == 'q') || (ch == 'Q')) { 796 /* user hit q or Q */ 797 KDB_FLAG_SET(CMD_INTERRUPT); /* command interrupted */ 798 KDB_STATE_CLEAR(PAGER); 799 /* end of command output; back to normal mode */ 800 kdb_grepping_flag = 0; 801 kdb_printf("\n"); 802 } else if (ch == ' ') { 803 kdb_printf("\r"); 804 suspend_grep = 1; /* for this recursion */ 805 } else if (ch == '\n' || ch == '\r') { 806 kdb_nextline = linecount - 1; 807 kdb_printf("\r"); 808 suspend_grep = 1; /* for this recursion */ 809 } else if (ch == '/' && !kdb_grepping_flag) { 810 kdb_printf("\r"); 811 kdb_getstr(kdb_grep_string, KDB_GREP_STRLEN, 812 kdbgetenv("SEARCHPROMPT") ?: "search> "); 813 *strchrnul(kdb_grep_string, '\n') = '\0'; 814 kdb_grepping_flag += KDB_GREPPING_FLAG_SEARCH; 815 suspend_grep = 1; /* for this recursion */ 816 } else if (ch) { 817 /* user hit something unexpected */ 818 suspend_grep = 1; /* for this recursion */ 819 if (ch != '/') 820 kdb_printf( 821 "\nOnly 'q', 'Q' or '/' are processed at " 822 "more prompt, input ignored\n"); 823 else 824 kdb_printf("\n'/' cannot be used during | " 825 "grep filtering, input ignored\n"); 826 } else if (kdb_grepping_flag) { 827 /* user hit enter */ 828 suspend_grep = 1; /* for this recursion */ 829 kdb_printf("\n"); 830 } 831 kdb_input_flush(); 832 } 833 834 /* 835 * For grep searches, shift the printed string left. 836 * replaced_byte contains the character that was overwritten with 837 * the terminating null, and cphold points to the null. 838 * Then adjust the notion of available space in the buffer. 839 */ 840 if (kdb_grepping_flag && !suspend_grep) { 841 *cphold = replaced_byte; 842 strcpy(kdb_buffer, cphold); 843 len = strlen(kdb_buffer); 844 next_avail = kdb_buffer + len; 845 size_avail = sizeof(kdb_buffer) - len; 846 } 847 848 kdb_print_out: 849 suspend_grep = 0; /* end of what may have been a recursive call */ 850 if (logging) 851 console_loglevel = saved_loglevel; 852 /* kdb_printf_cpu locked the code above. */ 853 smp_store_release(&kdb_printf_cpu, old_cpu); 854 local_irq_restore(flags); 855 return retlen; 856 } 857 858 int kdb_printf(const char *fmt, ...) 859 { 860 va_list ap; 861 int r; 862 863 va_start(ap, fmt); 864 r = vkdb_printf(KDB_MSGSRC_INTERNAL, fmt, ap); 865 va_end(ap); 866 867 return r; 868 } 869 EXPORT_SYMBOL_GPL(kdb_printf); 870