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 int kdb_printf_cpu = -1; 34 35 static int kgdb_transition_check(char *buffer) 36 { 37 if (buffer[0] != '+' && buffer[0] != '$') { 38 KDB_STATE_SET(KGDB_TRANS); 39 kdb_printf("%s", buffer); 40 } else { 41 int slen = strlen(buffer); 42 if (slen > 3 && buffer[slen - 3] == '#') { 43 kdb_gdb_state_pass(buffer); 44 strcpy(buffer, "kgdb"); 45 KDB_STATE_SET(DOING_KGDB); 46 return 1; 47 } 48 } 49 return 0; 50 } 51 52 /** 53 * kdb_handle_escape() - validity check on an accumulated escape sequence. 54 * @buf: Accumulated escape characters to be examined. Note that buf 55 * is not a string, it is an array of characters and need not be 56 * nil terminated. 57 * @sz: Number of accumulated escape characters. 58 * 59 * Return: -1 if the escape sequence is unwanted, 0 if it is incomplete, 60 * otherwise it returns a mapped key value to pass to the upper layers. 61 */ 62 static int kdb_handle_escape(char *buf, size_t sz) 63 { 64 char *lastkey = buf + sz - 1; 65 66 switch (sz) { 67 case 1: 68 if (*lastkey == '\e') 69 return 0; 70 break; 71 72 case 2: /* \e<something> */ 73 if (*lastkey == '[') 74 return 0; 75 break; 76 77 case 3: 78 switch (*lastkey) { 79 case 'A': /* \e[A, up arrow */ 80 return 16; 81 case 'B': /* \e[B, down arrow */ 82 return 14; 83 case 'C': /* \e[C, right arrow */ 84 return 6; 85 case 'D': /* \e[D, left arrow */ 86 return 2; 87 case '1': /* \e[<1,3,4>], may be home, del, end */ 88 case '3': 89 case '4': 90 return 0; 91 } 92 break; 93 94 case 4: 95 if (*lastkey == '~') { 96 switch (buf[2]) { 97 case '1': /* \e[1~, home */ 98 return 1; 99 case '3': /* \e[3~, del */ 100 return 4; 101 case '4': /* \e[4~, end */ 102 return 5; 103 } 104 } 105 break; 106 } 107 108 return -1; 109 } 110 111 /** 112 * kdb_getchar() - Read a single character from a kdb console (or consoles). 113 * 114 * Other than polling the various consoles that are currently enabled, 115 * most of the work done in this function is dealing with escape sequences. 116 * 117 * An escape key could be the start of a vt100 control sequence such as \e[D 118 * (left arrow) or it could be a character in its own right. The standard 119 * method for detecting the difference is to wait for 2 seconds to see if there 120 * are any other characters. kdb is complicated by the lack of a timer service 121 * (interrupts are off), by multiple input sources. Escape sequence processing 122 * has to be done as states in the polling loop. 123 * 124 * Return: The key pressed or a control code derived from an escape sequence. 125 */ 126 char kdb_getchar(void) 127 { 128 #define ESCAPE_UDELAY 1000 129 #define ESCAPE_DELAY (2*1000000/ESCAPE_UDELAY) /* 2 seconds worth of udelays */ 130 char buf[4]; /* longest vt100 escape sequence is 4 bytes */ 131 char *pbuf = buf; 132 int escape_delay = 0; 133 get_char_func *f, *f_prev = NULL; 134 int key; 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 * When the first character is received (or we get a change 155 * input source) we set ourselves up to handle an escape 156 * sequences (just in case). 157 */ 158 if (f_prev != f) { 159 f_prev = f; 160 pbuf = buf; 161 escape_delay = ESCAPE_DELAY; 162 } 163 164 *pbuf++ = key; 165 key = kdb_handle_escape(buf, pbuf - buf); 166 if (key < 0) /* no escape sequence; return best character */ 167 return buf[pbuf - buf == 2 ? 1 : 0]; 168 if (key > 0) 169 return key; 170 } 171 172 unreachable(); 173 } 174 175 /* 176 * kdb_read 177 * 178 * This function reads a string of characters, terminated by 179 * a newline, or by reaching the end of the supplied buffer, 180 * from the current kernel debugger console device. 181 * Parameters: 182 * buffer - Address of character buffer to receive input characters. 183 * bufsize - size, in bytes, of the character buffer 184 * Returns: 185 * Returns a pointer to the buffer containing the received 186 * character string. This string will be terminated by a 187 * newline character. 188 * Locking: 189 * No locks are required to be held upon entry to this 190 * function. It is not reentrant - it relies on the fact 191 * that while kdb is running on only one "master debug" cpu. 192 * Remarks: 193 * The buffer size must be >= 2. 194 */ 195 196 static char *kdb_read(char *buffer, size_t bufsize) 197 { 198 char *cp = buffer; 199 char *bufend = buffer+bufsize-2; /* Reserve space for newline 200 * and null byte */ 201 char *lastchar; 202 char *p_tmp; 203 char tmp; 204 static char tmpbuffer[CMD_BUFLEN]; 205 int len = strlen(buffer); 206 int len_tmp; 207 int tab = 0; 208 int count; 209 int i; 210 int diag, dtab_count; 211 int key, buf_size, ret; 212 213 214 diag = kdbgetintenv("DTABCOUNT", &dtab_count); 215 if (diag) 216 dtab_count = 30; 217 218 if (len > 0) { 219 cp += len; 220 if (*(buffer+len-1) == '\n') 221 cp--; 222 } 223 224 lastchar = cp; 225 *cp = '\0'; 226 kdb_printf("%s", buffer); 227 poll_again: 228 key = kdb_getchar(); 229 if (key != 9) 230 tab = 0; 231 switch (key) { 232 case 8: /* backspace */ 233 if (cp > buffer) { 234 if (cp < lastchar) { 235 memcpy(tmpbuffer, cp, lastchar - cp); 236 memcpy(cp-1, tmpbuffer, lastchar - cp); 237 } 238 *(--lastchar) = '\0'; 239 --cp; 240 kdb_printf("\b%s \r", cp); 241 tmp = *cp; 242 *cp = '\0'; 243 kdb_printf(kdb_prompt_str); 244 kdb_printf("%s", buffer); 245 *cp = tmp; 246 } 247 break; 248 case 13: /* enter */ 249 *lastchar++ = '\n'; 250 *lastchar++ = '\0'; 251 if (!KDB_STATE(KGDB_TRANS)) { 252 KDB_STATE_SET(KGDB_TRANS); 253 kdb_printf("%s", buffer); 254 } 255 kdb_printf("\n"); 256 return buffer; 257 case 4: /* Del */ 258 if (cp < lastchar) { 259 memcpy(tmpbuffer, cp+1, lastchar - cp - 1); 260 memcpy(cp, tmpbuffer, lastchar - cp - 1); 261 *(--lastchar) = '\0'; 262 kdb_printf("%s \r", cp); 263 tmp = *cp; 264 *cp = '\0'; 265 kdb_printf(kdb_prompt_str); 266 kdb_printf("%s", buffer); 267 *cp = tmp; 268 } 269 break; 270 case 1: /* Home */ 271 if (cp > buffer) { 272 kdb_printf("\r"); 273 kdb_printf(kdb_prompt_str); 274 cp = buffer; 275 } 276 break; 277 case 5: /* End */ 278 if (cp < lastchar) { 279 kdb_printf("%s", cp); 280 cp = lastchar; 281 } 282 break; 283 case 2: /* Left */ 284 if (cp > buffer) { 285 kdb_printf("\b"); 286 --cp; 287 } 288 break; 289 case 14: /* Down */ 290 memset(tmpbuffer, ' ', 291 strlen(kdb_prompt_str) + (lastchar-buffer)); 292 *(tmpbuffer+strlen(kdb_prompt_str) + 293 (lastchar-buffer)) = '\0'; 294 kdb_printf("\r%s\r", tmpbuffer); 295 *lastchar = (char)key; 296 *(lastchar+1) = '\0'; 297 return lastchar; 298 case 6: /* Right */ 299 if (cp < lastchar) { 300 kdb_printf("%c", *cp); 301 ++cp; 302 } 303 break; 304 case 16: /* Up */ 305 memset(tmpbuffer, ' ', 306 strlen(kdb_prompt_str) + (lastchar-buffer)); 307 *(tmpbuffer+strlen(kdb_prompt_str) + 308 (lastchar-buffer)) = '\0'; 309 kdb_printf("\r%s\r", tmpbuffer); 310 *lastchar = (char)key; 311 *(lastchar+1) = '\0'; 312 return lastchar; 313 case 9: /* Tab */ 314 if (tab < 2) 315 ++tab; 316 p_tmp = buffer; 317 while (*p_tmp == ' ') 318 p_tmp++; 319 if (p_tmp > cp) 320 break; 321 memcpy(tmpbuffer, p_tmp, cp-p_tmp); 322 *(tmpbuffer + (cp-p_tmp)) = '\0'; 323 p_tmp = strrchr(tmpbuffer, ' '); 324 if (p_tmp) 325 ++p_tmp; 326 else 327 p_tmp = tmpbuffer; 328 len = strlen(p_tmp); 329 buf_size = sizeof(tmpbuffer) - (p_tmp - tmpbuffer); 330 count = kallsyms_symbol_complete(p_tmp, buf_size); 331 if (tab == 2 && count > 0) { 332 kdb_printf("\n%d symbols are found.", count); 333 if (count > dtab_count) { 334 count = dtab_count; 335 kdb_printf(" But only first %d symbols will" 336 " be printed.\nYou can change the" 337 " environment variable DTABCOUNT.", 338 count); 339 } 340 kdb_printf("\n"); 341 for (i = 0; i < count; i++) { 342 ret = kallsyms_symbol_next(p_tmp, i, buf_size); 343 if (WARN_ON(!ret)) 344 break; 345 if (ret != -E2BIG) 346 kdb_printf("%s ", p_tmp); 347 else 348 kdb_printf("%s... ", p_tmp); 349 *(p_tmp + len) = '\0'; 350 } 351 if (i >= dtab_count) 352 kdb_printf("..."); 353 kdb_printf("\n"); 354 kdb_printf(kdb_prompt_str); 355 kdb_printf("%s", buffer); 356 } else if (tab != 2 && count > 0) { 357 len_tmp = strlen(p_tmp); 358 strncpy(p_tmp+len_tmp, cp, lastchar-cp+1); 359 len_tmp = strlen(p_tmp); 360 strncpy(cp, p_tmp+len, len_tmp-len + 1); 361 len = len_tmp - len; 362 kdb_printf("%s", cp); 363 cp += len; 364 lastchar += len; 365 } 366 kdb_nextline = 1; /* reset output line number */ 367 break; 368 default: 369 if (key >= 32 && lastchar < bufend) { 370 if (cp < lastchar) { 371 memcpy(tmpbuffer, cp, lastchar - cp); 372 memcpy(cp+1, tmpbuffer, lastchar - cp); 373 *++lastchar = '\0'; 374 *cp = key; 375 kdb_printf("%s\r", cp); 376 ++cp; 377 tmp = *cp; 378 *cp = '\0'; 379 kdb_printf(kdb_prompt_str); 380 kdb_printf("%s", buffer); 381 *cp = tmp; 382 } else { 383 *++lastchar = '\0'; 384 *cp++ = key; 385 /* The kgdb transition check will hide 386 * printed characters if we think that 387 * kgdb is connecting, until the check 388 * fails */ 389 if (!KDB_STATE(KGDB_TRANS)) { 390 if (kgdb_transition_check(buffer)) 391 return buffer; 392 } else { 393 kdb_printf("%c", key); 394 } 395 } 396 /* Special escape to kgdb */ 397 if (lastchar - buffer >= 5 && 398 strcmp(lastchar - 5, "$?#3f") == 0) { 399 kdb_gdb_state_pass(lastchar - 5); 400 strcpy(buffer, "kgdb"); 401 KDB_STATE_SET(DOING_KGDB); 402 return buffer; 403 } 404 if (lastchar - buffer >= 11 && 405 strcmp(lastchar - 11, "$qSupported") == 0) { 406 kdb_gdb_state_pass(lastchar - 11); 407 strcpy(buffer, "kgdb"); 408 KDB_STATE_SET(DOING_KGDB); 409 return buffer; 410 } 411 } 412 break; 413 } 414 goto poll_again; 415 } 416 417 /* 418 * kdb_getstr 419 * 420 * Print the prompt string and read a command from the 421 * input device. 422 * 423 * Parameters: 424 * buffer Address of buffer to receive command 425 * bufsize Size of buffer in bytes 426 * prompt Pointer to string to use as prompt string 427 * Returns: 428 * Pointer to command buffer. 429 * Locking: 430 * None. 431 * Remarks: 432 * For SMP kernels, the processor number will be 433 * substituted for %d, %x or %o in the prompt. 434 */ 435 436 char *kdb_getstr(char *buffer, size_t bufsize, const char *prompt) 437 { 438 if (prompt && kdb_prompt_str != prompt) 439 strscpy(kdb_prompt_str, prompt, CMD_BUFLEN); 440 kdb_printf(kdb_prompt_str); 441 kdb_nextline = 1; /* Prompt and input resets line number */ 442 return kdb_read(buffer, bufsize); 443 } 444 445 /* 446 * kdb_input_flush 447 * 448 * Get rid of any buffered console input. 449 * 450 * Parameters: 451 * none 452 * Returns: 453 * nothing 454 * Locking: 455 * none 456 * Remarks: 457 * Call this function whenever you want to flush input. If there is any 458 * outstanding input, it ignores all characters until there has been no 459 * data for approximately 1ms. 460 */ 461 462 static void kdb_input_flush(void) 463 { 464 get_char_func *f; 465 int res; 466 int flush_delay = 1; 467 while (flush_delay) { 468 flush_delay--; 469 empty: 470 touch_nmi_watchdog(); 471 for (f = &kdb_poll_funcs[0]; *f; ++f) { 472 res = (*f)(); 473 if (res != -1) { 474 flush_delay = 1; 475 goto empty; 476 } 477 } 478 if (flush_delay) 479 mdelay(1); 480 } 481 } 482 483 /* 484 * kdb_printf 485 * 486 * Print a string to the output device(s). 487 * 488 * Parameters: 489 * printf-like format and optional args. 490 * Returns: 491 * 0 492 * Locking: 493 * None. 494 * Remarks: 495 * use 'kdbcons->write()' to avoid polluting 'log_buf' with 496 * kdb output. 497 * 498 * If the user is doing a cmd args | grep srch 499 * then kdb_grepping_flag is set. 500 * In that case we need to accumulate full lines (ending in \n) before 501 * searching for the pattern. 502 */ 503 504 static char kdb_buffer[256]; /* A bit too big to go on stack */ 505 static char *next_avail = kdb_buffer; 506 static int size_avail; 507 static int suspend_grep; 508 509 /* 510 * search arg1 to see if it contains arg2 511 * (kdmain.c provides flags for ^pat and pat$) 512 * 513 * return 1 for found, 0 for not found 514 */ 515 static int kdb_search_string(char *searched, char *searchfor) 516 { 517 char firstchar, *cp; 518 int len1, len2; 519 520 /* not counting the newline at the end of "searched" */ 521 len1 = strlen(searched)-1; 522 len2 = strlen(searchfor); 523 if (len1 < len2) 524 return 0; 525 if (kdb_grep_leading && kdb_grep_trailing && len1 != len2) 526 return 0; 527 if (kdb_grep_leading) { 528 if (!strncmp(searched, searchfor, len2)) 529 return 1; 530 } else if (kdb_grep_trailing) { 531 if (!strncmp(searched+len1-len2, searchfor, len2)) 532 return 1; 533 } else { 534 firstchar = *searchfor; 535 cp = searched; 536 while ((cp = strchr(cp, firstchar))) { 537 if (!strncmp(cp, searchfor, len2)) 538 return 1; 539 cp++; 540 } 541 } 542 return 0; 543 } 544 545 int vkdb_printf(enum kdb_msgsrc src, const char *fmt, va_list ap) 546 { 547 int diag; 548 int linecount; 549 int colcount; 550 int logging, saved_loglevel = 0; 551 int retlen = 0; 552 int fnd, len; 553 int this_cpu, old_cpu; 554 char *cp, *cp2, *cphold = NULL, replaced_byte = ' '; 555 char *moreprompt = "more> "; 556 struct console *c = console_drivers; 557 unsigned long uninitialized_var(flags); 558 559 /* Serialize kdb_printf if multiple cpus try to write at once. 560 * But if any cpu goes recursive in kdb, just print the output, 561 * even if it is interleaved with any other text. 562 */ 563 local_irq_save(flags); 564 this_cpu = smp_processor_id(); 565 for (;;) { 566 old_cpu = cmpxchg(&kdb_printf_cpu, -1, this_cpu); 567 if (old_cpu == -1 || old_cpu == this_cpu) 568 break; 569 570 cpu_relax(); 571 } 572 573 diag = kdbgetintenv("LINES", &linecount); 574 if (diag || linecount <= 1) 575 linecount = 24; 576 577 diag = kdbgetintenv("COLUMNS", &colcount); 578 if (diag || colcount <= 1) 579 colcount = 80; 580 581 diag = kdbgetintenv("LOGGING", &logging); 582 if (diag) 583 logging = 0; 584 585 if (!kdb_grepping_flag || suspend_grep) { 586 /* normally, every vsnprintf starts a new buffer */ 587 next_avail = kdb_buffer; 588 size_avail = sizeof(kdb_buffer); 589 } 590 vsnprintf(next_avail, size_avail, fmt, ap); 591 592 /* 593 * If kdb_parse() found that the command was cmd xxx | grep yyy 594 * then kdb_grepping_flag is set, and kdb_grep_string contains yyy 595 * 596 * Accumulate the print data up to a newline before searching it. 597 * (vsnprintf does null-terminate the string that it generates) 598 */ 599 600 /* skip the search if prints are temporarily unconditional */ 601 if (!suspend_grep && kdb_grepping_flag) { 602 cp = strchr(kdb_buffer, '\n'); 603 if (!cp) { 604 /* 605 * Special cases that don't end with newlines 606 * but should be written without one: 607 * The "[nn]kdb> " prompt should 608 * appear at the front of the buffer. 609 * 610 * The "[nn]more " prompt should also be 611 * (MOREPROMPT -> moreprompt) 612 * written * but we print that ourselves, 613 * we set the suspend_grep flag to make 614 * it unconditional. 615 * 616 */ 617 if (next_avail == kdb_buffer) { 618 /* 619 * these should occur after a newline, 620 * so they will be at the front of the 621 * buffer 622 */ 623 cp2 = kdb_buffer; 624 len = strlen(kdb_prompt_str); 625 if (!strncmp(cp2, kdb_prompt_str, len)) { 626 /* 627 * We're about to start a new 628 * command, so we can go back 629 * to normal mode. 630 */ 631 kdb_grepping_flag = 0; 632 goto kdb_printit; 633 } 634 } 635 /* no newline; don't search/write the buffer 636 until one is there */ 637 len = strlen(kdb_buffer); 638 next_avail = kdb_buffer + len; 639 size_avail = sizeof(kdb_buffer) - len; 640 goto kdb_print_out; 641 } 642 643 /* 644 * The newline is present; print through it or discard 645 * it, depending on the results of the search. 646 */ 647 cp++; /* to byte after the newline */ 648 replaced_byte = *cp; /* remember what/where it was */ 649 cphold = cp; 650 *cp = '\0'; /* end the string for our search */ 651 652 /* 653 * We now have a newline at the end of the string 654 * Only continue with this output if it contains the 655 * search string. 656 */ 657 fnd = kdb_search_string(kdb_buffer, kdb_grep_string); 658 if (!fnd) { 659 /* 660 * At this point the complete line at the start 661 * of kdb_buffer can be discarded, as it does 662 * not contain what the user is looking for. 663 * Shift the buffer left. 664 */ 665 *cphold = replaced_byte; 666 strcpy(kdb_buffer, cphold); 667 len = strlen(kdb_buffer); 668 next_avail = kdb_buffer + len; 669 size_avail = sizeof(kdb_buffer) - len; 670 goto kdb_print_out; 671 } 672 if (kdb_grepping_flag >= KDB_GREPPING_FLAG_SEARCH) 673 /* 674 * This was a interactive search (using '/' at more 675 * prompt) and it has completed. Clear the flag. 676 */ 677 kdb_grepping_flag = 0; 678 /* 679 * at this point the string is a full line and 680 * should be printed, up to the null. 681 */ 682 } 683 kdb_printit: 684 685 /* 686 * Write to all consoles. 687 */ 688 retlen = strlen(kdb_buffer); 689 cp = (char *) printk_skip_headers(kdb_buffer); 690 if (!dbg_kdb_mode && kgdb_connected) { 691 gdbstub_msg_write(cp, retlen - (cp - kdb_buffer)); 692 } else { 693 if (dbg_io_ops && !dbg_io_ops->is_console) { 694 len = retlen - (cp - kdb_buffer); 695 cp2 = cp; 696 while (len--) { 697 dbg_io_ops->write_char(*cp2); 698 cp2++; 699 } 700 } 701 while (c) { 702 c->write(c, cp, retlen - (cp - kdb_buffer)); 703 touch_nmi_watchdog(); 704 c = c->next; 705 } 706 } 707 if (logging) { 708 saved_loglevel = console_loglevel; 709 console_loglevel = CONSOLE_LOGLEVEL_SILENT; 710 if (printk_get_level(kdb_buffer) || src == KDB_MSGSRC_PRINTK) 711 printk("%s", kdb_buffer); 712 else 713 pr_info("%s", kdb_buffer); 714 } 715 716 if (KDB_STATE(PAGER)) { 717 /* 718 * Check printed string to decide how to bump the 719 * kdb_nextline to control when the more prompt should 720 * show up. 721 */ 722 int got = 0; 723 len = retlen; 724 while (len--) { 725 if (kdb_buffer[len] == '\n') { 726 kdb_nextline++; 727 got = 0; 728 } else if (kdb_buffer[len] == '\r') { 729 got = 0; 730 } else { 731 got++; 732 } 733 } 734 kdb_nextline += got / (colcount + 1); 735 } 736 737 /* check for having reached the LINES number of printed lines */ 738 if (kdb_nextline >= linecount) { 739 char ch; 740 741 /* Watch out for recursion here. Any routine that calls 742 * kdb_printf will come back through here. And kdb_read 743 * uses kdb_printf to echo on serial consoles ... 744 */ 745 kdb_nextline = 1; /* In case of recursion */ 746 747 /* 748 * Pause until cr. 749 */ 750 moreprompt = kdbgetenv("MOREPROMPT"); 751 if (moreprompt == NULL) 752 moreprompt = "more> "; 753 754 kdb_input_flush(); 755 c = console_drivers; 756 757 if (dbg_io_ops && !dbg_io_ops->is_console) { 758 len = strlen(moreprompt); 759 cp = moreprompt; 760 while (len--) { 761 dbg_io_ops->write_char(*cp); 762 cp++; 763 } 764 } 765 while (c) { 766 c->write(c, moreprompt, strlen(moreprompt)); 767 touch_nmi_watchdog(); 768 c = c->next; 769 } 770 771 if (logging) 772 printk("%s", moreprompt); 773 774 ch = kdb_getchar(); 775 kdb_nextline = 1; /* Really set output line 1 */ 776 777 /* empty and reset the buffer: */ 778 kdb_buffer[0] = '\0'; 779 next_avail = kdb_buffer; 780 size_avail = sizeof(kdb_buffer); 781 if ((ch == 'q') || (ch == 'Q')) { 782 /* user hit q or Q */ 783 KDB_FLAG_SET(CMD_INTERRUPT); /* command interrupted */ 784 KDB_STATE_CLEAR(PAGER); 785 /* end of command output; back to normal mode */ 786 kdb_grepping_flag = 0; 787 kdb_printf("\n"); 788 } else if (ch == ' ') { 789 kdb_printf("\r"); 790 suspend_grep = 1; /* for this recursion */ 791 } else if (ch == '\n' || ch == '\r') { 792 kdb_nextline = linecount - 1; 793 kdb_printf("\r"); 794 suspend_grep = 1; /* for this recursion */ 795 } else if (ch == '/' && !kdb_grepping_flag) { 796 kdb_printf("\r"); 797 kdb_getstr(kdb_grep_string, KDB_GREP_STRLEN, 798 kdbgetenv("SEARCHPROMPT") ?: "search> "); 799 *strchrnul(kdb_grep_string, '\n') = '\0'; 800 kdb_grepping_flag += KDB_GREPPING_FLAG_SEARCH; 801 suspend_grep = 1; /* for this recursion */ 802 } else if (ch) { 803 /* user hit something unexpected */ 804 suspend_grep = 1; /* for this recursion */ 805 if (ch != '/') 806 kdb_printf( 807 "\nOnly 'q', 'Q' or '/' are processed at " 808 "more prompt, input ignored\n"); 809 else 810 kdb_printf("\n'/' cannot be used during | " 811 "grep filtering, input ignored\n"); 812 } else if (kdb_grepping_flag) { 813 /* user hit enter */ 814 suspend_grep = 1; /* for this recursion */ 815 kdb_printf("\n"); 816 } 817 kdb_input_flush(); 818 } 819 820 /* 821 * For grep searches, shift the printed string left. 822 * replaced_byte contains the character that was overwritten with 823 * the terminating null, and cphold points to the null. 824 * Then adjust the notion of available space in the buffer. 825 */ 826 if (kdb_grepping_flag && !suspend_grep) { 827 *cphold = replaced_byte; 828 strcpy(kdb_buffer, cphold); 829 len = strlen(kdb_buffer); 830 next_avail = kdb_buffer + len; 831 size_avail = sizeof(kdb_buffer) - len; 832 } 833 834 kdb_print_out: 835 suspend_grep = 0; /* end of what may have been a recursive call */ 836 if (logging) 837 console_loglevel = saved_loglevel; 838 /* kdb_printf_cpu locked the code above. */ 839 smp_store_release(&kdb_printf_cpu, old_cpu); 840 local_irq_restore(flags); 841 return retlen; 842 } 843 844 int kdb_printf(const char *fmt, ...) 845 { 846 va_list ap; 847 int r; 848 849 va_start(ap, fmt); 850 r = vkdb_printf(KDB_MSGSRC_INTERNAL, fmt, ap); 851 va_end(ap); 852 853 return r; 854 } 855 EXPORT_SYMBOL_GPL(kdb_printf); 856