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 cookie; 549 int len; 550 551 if (msg_len == 0) 552 return; 553 554 cp = msg; 555 len = msg_len; 556 557 while (len--) { 558 dbg_io_ops->write_char(*cp); 559 cp++; 560 } 561 562 /* 563 * The console_srcu_read_lock() only provides safe console list 564 * traversal. The use of the ->write() callback relies on all other 565 * CPUs being stopped at the moment and console drivers being able to 566 * handle reentrance when @oops_in_progress is set. 567 * 568 * There is no guarantee that every console driver can handle 569 * reentrance in this way; the developer deploying the debugger 570 * is responsible for ensuring that the console drivers they 571 * have selected handle reentrance appropriately. 572 */ 573 cookie = console_srcu_read_lock(); 574 for_each_console_srcu(c) { 575 if (!(console_srcu_read_flags(c) & CON_ENABLED)) 576 continue; 577 if (c == dbg_io_ops->cons) 578 continue; 579 /* 580 * Set oops_in_progress to encourage the console drivers to 581 * disregard their internal spin locks: in the current calling 582 * context the risk of deadlock is a bigger problem than risks 583 * due to re-entering the console driver. We operate directly on 584 * oops_in_progress rather than using bust_spinlocks() because 585 * the calls bust_spinlocks() makes on exit are not appropriate 586 * for this calling context. 587 */ 588 ++oops_in_progress; 589 c->write(c, msg, msg_len); 590 --oops_in_progress; 591 touch_nmi_watchdog(); 592 } 593 console_srcu_read_unlock(cookie); 594 } 595 596 int vkdb_printf(enum kdb_msgsrc src, const char *fmt, va_list ap) 597 { 598 int diag; 599 int linecount; 600 int colcount; 601 int logging, saved_loglevel = 0; 602 int retlen = 0; 603 int fnd, len; 604 int this_cpu, old_cpu; 605 char *cp, *cp2, *cphold = NULL, replaced_byte = ' '; 606 char *moreprompt = "more> "; 607 unsigned long flags; 608 609 /* Serialize kdb_printf if multiple cpus try to write at once. 610 * But if any cpu goes recursive in kdb, just print the output, 611 * even if it is interleaved with any other text. 612 */ 613 local_irq_save(flags); 614 this_cpu = smp_processor_id(); 615 for (;;) { 616 old_cpu = cmpxchg(&kdb_printf_cpu, -1, this_cpu); 617 if (old_cpu == -1 || old_cpu == this_cpu) 618 break; 619 620 cpu_relax(); 621 } 622 623 diag = kdbgetintenv("LINES", &linecount); 624 if (diag || linecount <= 1) 625 linecount = 24; 626 627 diag = kdbgetintenv("COLUMNS", &colcount); 628 if (diag || colcount <= 1) 629 colcount = 80; 630 631 diag = kdbgetintenv("LOGGING", &logging); 632 if (diag) 633 logging = 0; 634 635 if (!kdb_grepping_flag || suspend_grep) { 636 /* normally, every vsnprintf starts a new buffer */ 637 next_avail = kdb_buffer; 638 size_avail = sizeof(kdb_buffer); 639 } 640 vsnprintf(next_avail, size_avail, fmt, ap); 641 642 /* 643 * If kdb_parse() found that the command was cmd xxx | grep yyy 644 * then kdb_grepping_flag is set, and kdb_grep_string contains yyy 645 * 646 * Accumulate the print data up to a newline before searching it. 647 * (vsnprintf does null-terminate the string that it generates) 648 */ 649 650 /* skip the search if prints are temporarily unconditional */ 651 if (!suspend_grep && kdb_grepping_flag) { 652 cp = strchr(kdb_buffer, '\n'); 653 if (!cp) { 654 /* 655 * Special cases that don't end with newlines 656 * but should be written without one: 657 * The "[nn]kdb> " prompt should 658 * appear at the front of the buffer. 659 * 660 * The "[nn]more " prompt should also be 661 * (MOREPROMPT -> moreprompt) 662 * written * but we print that ourselves, 663 * we set the suspend_grep flag to make 664 * it unconditional. 665 * 666 */ 667 if (next_avail == kdb_buffer) { 668 /* 669 * these should occur after a newline, 670 * so they will be at the front of the 671 * buffer 672 */ 673 cp2 = kdb_buffer; 674 len = strlen(kdb_prompt_str); 675 if (!strncmp(cp2, kdb_prompt_str, len)) { 676 /* 677 * We're about to start a new 678 * command, so we can go back 679 * to normal mode. 680 */ 681 kdb_grepping_flag = 0; 682 goto kdb_printit; 683 } 684 } 685 /* no newline; don't search/write the buffer 686 until one is there */ 687 len = strlen(kdb_buffer); 688 next_avail = kdb_buffer + len; 689 size_avail = sizeof(kdb_buffer) - len; 690 goto kdb_print_out; 691 } 692 693 /* 694 * The newline is present; print through it or discard 695 * it, depending on the results of the search. 696 */ 697 cp++; /* to byte after the newline */ 698 replaced_byte = *cp; /* remember what/where it was */ 699 cphold = cp; 700 *cp = '\0'; /* end the string for our search */ 701 702 /* 703 * We now have a newline at the end of the string 704 * Only continue with this output if it contains the 705 * search string. 706 */ 707 fnd = kdb_search_string(kdb_buffer, kdb_grep_string); 708 if (!fnd) { 709 /* 710 * At this point the complete line at the start 711 * of kdb_buffer can be discarded, as it does 712 * not contain what the user is looking for. 713 * Shift the buffer left. 714 */ 715 *cphold = replaced_byte; 716 strcpy(kdb_buffer, cphold); 717 len = strlen(kdb_buffer); 718 next_avail = kdb_buffer + len; 719 size_avail = sizeof(kdb_buffer) - len; 720 goto kdb_print_out; 721 } 722 if (kdb_grepping_flag >= KDB_GREPPING_FLAG_SEARCH) { 723 /* 724 * This was a interactive search (using '/' at more 725 * prompt) and it has completed. Replace the \0 with 726 * its original value to ensure multi-line strings 727 * are handled properly, and return to normal mode. 728 */ 729 *cphold = replaced_byte; 730 kdb_grepping_flag = 0; 731 } 732 /* 733 * at this point the string is a full line and 734 * should be printed, up to the null. 735 */ 736 } 737 kdb_printit: 738 739 /* 740 * Write to all consoles. 741 */ 742 retlen = strlen(kdb_buffer); 743 cp = (char *) printk_skip_headers(kdb_buffer); 744 if (!dbg_kdb_mode && kgdb_connected) 745 gdbstub_msg_write(cp, retlen - (cp - kdb_buffer)); 746 else 747 kdb_msg_write(cp, retlen - (cp - kdb_buffer)); 748 749 if (logging) { 750 saved_loglevel = console_loglevel; 751 console_loglevel = CONSOLE_LOGLEVEL_SILENT; 752 if (printk_get_level(kdb_buffer) || src == KDB_MSGSRC_PRINTK) 753 printk("%s", kdb_buffer); 754 else 755 pr_info("%s", kdb_buffer); 756 } 757 758 if (KDB_STATE(PAGER)) { 759 /* 760 * Check printed string to decide how to bump the 761 * kdb_nextline to control when the more prompt should 762 * show up. 763 */ 764 int got = 0; 765 len = retlen; 766 while (len--) { 767 if (kdb_buffer[len] == '\n') { 768 kdb_nextline++; 769 got = 0; 770 } else if (kdb_buffer[len] == '\r') { 771 got = 0; 772 } else { 773 got++; 774 } 775 } 776 kdb_nextline += got / (colcount + 1); 777 } 778 779 /* check for having reached the LINES number of printed lines */ 780 if (kdb_nextline >= linecount) { 781 char ch; 782 783 /* Watch out for recursion here. Any routine that calls 784 * kdb_printf will come back through here. And kdb_read 785 * uses kdb_printf to echo on serial consoles ... 786 */ 787 kdb_nextline = 1; /* In case of recursion */ 788 789 /* 790 * Pause until cr. 791 */ 792 moreprompt = kdbgetenv("MOREPROMPT"); 793 if (moreprompt == NULL) 794 moreprompt = "more> "; 795 796 kdb_input_flush(); 797 kdb_msg_write(moreprompt, strlen(moreprompt)); 798 799 if (logging) 800 printk("%s", moreprompt); 801 802 ch = kdb_getchar(); 803 kdb_nextline = 1; /* Really set output line 1 */ 804 805 /* empty and reset the buffer: */ 806 kdb_buffer[0] = '\0'; 807 next_avail = kdb_buffer; 808 size_avail = sizeof(kdb_buffer); 809 if ((ch == 'q') || (ch == 'Q')) { 810 /* user hit q or Q */ 811 KDB_FLAG_SET(CMD_INTERRUPT); /* command interrupted */ 812 KDB_STATE_CLEAR(PAGER); 813 /* end of command output; back to normal mode */ 814 kdb_grepping_flag = 0; 815 kdb_printf("\n"); 816 } else if (ch == ' ') { 817 kdb_printf("\r"); 818 suspend_grep = 1; /* for this recursion */ 819 } else if (ch == '\n' || ch == '\r') { 820 kdb_nextline = linecount - 1; 821 kdb_printf("\r"); 822 suspend_grep = 1; /* for this recursion */ 823 } else if (ch == '/' && !kdb_grepping_flag) { 824 kdb_printf("\r"); 825 kdb_getstr(kdb_grep_string, KDB_GREP_STRLEN, 826 kdbgetenv("SEARCHPROMPT") ?: "search> "); 827 *strchrnul(kdb_grep_string, '\n') = '\0'; 828 kdb_grepping_flag += KDB_GREPPING_FLAG_SEARCH; 829 suspend_grep = 1; /* for this recursion */ 830 } else if (ch) { 831 /* user hit something unexpected */ 832 suspend_grep = 1; /* for this recursion */ 833 if (ch != '/') 834 kdb_printf( 835 "\nOnly 'q', 'Q' or '/' are processed at " 836 "more prompt, input ignored\n"); 837 else 838 kdb_printf("\n'/' cannot be used during | " 839 "grep filtering, input ignored\n"); 840 } else if (kdb_grepping_flag) { 841 /* user hit enter */ 842 suspend_grep = 1; /* for this recursion */ 843 kdb_printf("\n"); 844 } 845 kdb_input_flush(); 846 } 847 848 /* 849 * For grep searches, shift the printed string left. 850 * replaced_byte contains the character that was overwritten with 851 * the terminating null, and cphold points to the null. 852 * Then adjust the notion of available space in the buffer. 853 */ 854 if (kdb_grepping_flag && !suspend_grep) { 855 *cphold = replaced_byte; 856 strcpy(kdb_buffer, cphold); 857 len = strlen(kdb_buffer); 858 next_avail = kdb_buffer + len; 859 size_avail = sizeof(kdb_buffer) - len; 860 } 861 862 kdb_print_out: 863 suspend_grep = 0; /* end of what may have been a recursive call */ 864 if (logging) 865 console_loglevel = saved_loglevel; 866 /* kdb_printf_cpu locked the code above. */ 867 smp_store_release(&kdb_printf_cpu, old_cpu); 868 local_irq_restore(flags); 869 return retlen; 870 } 871 872 int kdb_printf(const char *fmt, ...) 873 { 874 va_list ap; 875 int r; 876 877 va_start(ap, fmt); 878 r = vkdb_printf(KDB_MSGSRC_INTERNAL, fmt, ap); 879 va_end(ap); 880 881 return r; 882 } 883 EXPORT_SYMBOL_GPL(kdb_printf); 884