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 char tmp; 243 static char tmpbuffer[CMD_BUFLEN]; 244 int len = strlen(buffer); 245 int len_tmp; 246 int tab = 0; 247 int count; 248 int i; 249 int diag, dtab_count; 250 int key, ret; 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 memmove(cp-1, cp, lastchar - cp + 1); 273 lastchar--; 274 cp--; 275 kdb_printf("\b%s ", cp); 276 kdb_position_cursor(kdb_prompt_str, buffer, cp); 277 } 278 break; 279 case 10: /* linefeed */ 280 case 13: /* carriage return */ 281 *lastchar++ = '\n'; 282 *lastchar++ = '\0'; 283 if (!KDB_STATE(KGDB_TRANS)) { 284 KDB_STATE_SET(KGDB_TRANS); 285 kdb_printf("%s", buffer); 286 } 287 kdb_printf("\n"); 288 return buffer; 289 case 4: /* Del */ 290 if (cp < lastchar) { 291 memmove(cp, cp+1, lastchar - cp); 292 lastchar--; 293 kdb_printf("%s ", cp); 294 kdb_position_cursor(kdb_prompt_str, buffer, cp); 295 } 296 break; 297 case 1: /* Home */ 298 if (cp > buffer) { 299 cp = buffer; 300 kdb_position_cursor(kdb_prompt_str, buffer, cp); 301 } 302 break; 303 case 5: /* End */ 304 if (cp < lastchar) { 305 kdb_printf("%s", cp); 306 cp = lastchar; 307 } 308 break; 309 case 2: /* Left */ 310 if (cp > buffer) { 311 kdb_printf("\b"); 312 --cp; 313 } 314 break; 315 case 14: /* Down */ 316 case 16: /* Up */ 317 kdb_printf("\r%*c\r", 318 (int)(strlen(kdb_prompt_str) + (lastchar - buffer)), 319 ' '); 320 *lastchar = (char)key; 321 *(lastchar+1) = '\0'; 322 return lastchar; 323 case 6: /* Right */ 324 if (cp < lastchar) { 325 kdb_printf("%c", *cp); 326 ++cp; 327 } 328 break; 329 case 9: /* Tab */ 330 if (tab < 2) 331 ++tab; 332 333 tmp = *cp; 334 *cp = '\0'; 335 p_tmp = strrchr(buffer, ' '); 336 p_tmp = (p_tmp ? p_tmp + 1 : buffer); 337 strscpy(tmpbuffer, p_tmp, sizeof(tmpbuffer)); 338 *cp = tmp; 339 340 len = strlen(tmpbuffer); 341 count = kallsyms_symbol_complete(tmpbuffer, sizeof(tmpbuffer)); 342 if (tab == 2 && count > 0) { 343 kdb_printf("\n%d symbols are found.", count); 344 if (count > dtab_count) { 345 count = dtab_count; 346 kdb_printf(" But only first %d symbols will" 347 " be printed.\nYou can change the" 348 " environment variable DTABCOUNT.", 349 count); 350 } 351 kdb_printf("\n"); 352 for (i = 0; i < count; i++) { 353 ret = kallsyms_symbol_next(tmpbuffer, i, sizeof(tmpbuffer)); 354 if (WARN_ON(!ret)) 355 break; 356 if (ret != -E2BIG) 357 kdb_printf("%s ", tmpbuffer); 358 else 359 kdb_printf("%s... ", tmpbuffer); 360 tmpbuffer[len] = '\0'; 361 } 362 if (i >= dtab_count) 363 kdb_printf("..."); 364 kdb_printf("\n"); 365 kdb_printf("%s", kdb_prompt_str); 366 kdb_printf("%s", buffer); 367 if (cp != lastchar) 368 kdb_position_cursor(kdb_prompt_str, buffer, cp); 369 } else if (tab != 2 && count > 0) { 370 /* How many new characters do we want from tmpbuffer? */ 371 len_tmp = strlen(tmpbuffer) - len; 372 if (lastchar + len_tmp >= bufend) 373 len_tmp = bufend - lastchar; 374 375 if (len_tmp) { 376 /* + 1 ensures the '\0' is memmove'd */ 377 memmove(cp+len_tmp, cp, (lastchar-cp) + 1); 378 memcpy(cp, tmpbuffer+len, len_tmp); 379 kdb_printf("%s", cp); 380 cp += len_tmp; 381 lastchar += len_tmp; 382 if (cp != lastchar) 383 kdb_position_cursor(kdb_prompt_str, 384 buffer, cp); 385 } 386 } 387 kdb_nextline = 1; /* reset output line number */ 388 break; 389 default: 390 if (key >= 32 && lastchar < bufend) { 391 if (cp < lastchar) { 392 memmove(cp+1, cp, lastchar - cp + 1); 393 lastchar++; 394 *cp = key; 395 kdb_printf("%s", cp); 396 ++cp; 397 kdb_position_cursor(kdb_prompt_str, buffer, cp); 398 } else { 399 *++lastchar = '\0'; 400 *cp++ = key; 401 /* The kgdb transition check will hide 402 * printed characters if we think that 403 * kgdb is connecting, until the check 404 * fails */ 405 if (!KDB_STATE(KGDB_TRANS)) { 406 if (kgdb_transition_check(buffer)) 407 return buffer; 408 } else { 409 kdb_printf("%c", key); 410 } 411 } 412 /* Special escape to kgdb */ 413 if (lastchar - buffer >= 5 && 414 strcmp(lastchar - 5, "$?#3f") == 0) { 415 kdb_gdb_state_pass(lastchar - 5); 416 strcpy(buffer, "kgdb"); 417 KDB_STATE_SET(DOING_KGDB); 418 return buffer; 419 } 420 if (lastchar - buffer >= 11 && 421 strcmp(lastchar - 11, "$qSupported") == 0) { 422 kdb_gdb_state_pass(lastchar - 11); 423 strcpy(buffer, "kgdb"); 424 KDB_STATE_SET(DOING_KGDB); 425 return buffer; 426 } 427 } 428 break; 429 } 430 goto poll_again; 431 } 432 433 /* 434 * kdb_getstr 435 * 436 * Print the prompt string and read a command from the 437 * input device. 438 * 439 * Parameters: 440 * buffer Address of buffer to receive command 441 * bufsize Size of buffer in bytes 442 * prompt Pointer to string to use as prompt string 443 * Returns: 444 * Pointer to command buffer. 445 * Locking: 446 * None. 447 * Remarks: 448 * For SMP kernels, the processor number will be 449 * substituted for %d, %x or %o in the prompt. 450 */ 451 452 char *kdb_getstr(char *buffer, size_t bufsize, const char *prompt) 453 { 454 if (prompt && kdb_prompt_str != prompt) 455 strscpy(kdb_prompt_str, prompt, CMD_BUFLEN); 456 kdb_printf("%s", kdb_prompt_str); 457 kdb_nextline = 1; /* Prompt and input resets line number */ 458 return kdb_read(buffer, bufsize); 459 } 460 461 /* 462 * kdb_input_flush 463 * 464 * Get rid of any buffered console input. 465 * 466 * Parameters: 467 * none 468 * Returns: 469 * nothing 470 * Locking: 471 * none 472 * Remarks: 473 * Call this function whenever you want to flush input. If there is any 474 * outstanding input, it ignores all characters until there has been no 475 * data for approximately 1ms. 476 */ 477 478 static void kdb_input_flush(void) 479 { 480 get_char_func *f; 481 int res; 482 int flush_delay = 1; 483 while (flush_delay) { 484 flush_delay--; 485 empty: 486 touch_nmi_watchdog(); 487 for (f = &kdb_poll_funcs[0]; *f; ++f) { 488 res = (*f)(); 489 if (res != -1) { 490 flush_delay = 1; 491 goto empty; 492 } 493 } 494 if (flush_delay) 495 mdelay(1); 496 } 497 } 498 499 /* 500 * kdb_printf 501 * 502 * Print a string to the output device(s). 503 * 504 * Parameters: 505 * printf-like format and optional args. 506 * Returns: 507 * 0 508 * Locking: 509 * None. 510 * Remarks: 511 * use 'kdbcons->write()' to avoid polluting 'log_buf' with 512 * kdb output. 513 * 514 * If the user is doing a cmd args | grep srch 515 * then kdb_grepping_flag is set. 516 * In that case we need to accumulate full lines (ending in \n) before 517 * searching for the pattern. 518 */ 519 520 static char kdb_buffer[256]; /* A bit too big to go on stack */ 521 static char *next_avail = kdb_buffer; 522 static int size_avail; 523 static int suspend_grep; 524 525 /* 526 * search arg1 to see if it contains arg2 527 * (kdmain.c provides flags for ^pat and pat$) 528 * 529 * return 1 for found, 0 for not found 530 */ 531 static int kdb_search_string(char *searched, char *searchfor) 532 { 533 char firstchar, *cp; 534 int len1, len2; 535 536 /* not counting the newline at the end of "searched" */ 537 len1 = strlen(searched)-1; 538 len2 = strlen(searchfor); 539 if (len1 < len2) 540 return 0; 541 if (kdb_grep_leading && kdb_grep_trailing && len1 != len2) 542 return 0; 543 if (kdb_grep_leading) { 544 if (!strncmp(searched, searchfor, len2)) 545 return 1; 546 } else if (kdb_grep_trailing) { 547 if (!strncmp(searched+len1-len2, searchfor, len2)) 548 return 1; 549 } else { 550 firstchar = *searchfor; 551 cp = searched; 552 while ((cp = strchr(cp, firstchar))) { 553 if (!strncmp(cp, searchfor, len2)) 554 return 1; 555 cp++; 556 } 557 } 558 return 0; 559 } 560 561 static void kdb_msg_write(const char *msg, int msg_len) 562 { 563 struct console *c; 564 const char *cp; 565 int cookie; 566 int len; 567 568 if (msg_len == 0) 569 return; 570 571 cp = msg; 572 len = msg_len; 573 574 while (len--) { 575 dbg_io_ops->write_char(*cp); 576 cp++; 577 } 578 579 /* 580 * The console_srcu_read_lock() only provides safe console list 581 * traversal. The use of the ->write() callback relies on all other 582 * CPUs being stopped at the moment and console drivers being able to 583 * handle reentrance when @oops_in_progress is set. 584 * 585 * There is no guarantee that every console driver can handle 586 * reentrance in this way; the developer deploying the debugger 587 * is responsible for ensuring that the console drivers they 588 * have selected handle reentrance appropriately. 589 */ 590 cookie = console_srcu_read_lock(); 591 for_each_console_srcu(c) { 592 if (!(console_srcu_read_flags(c) & CON_ENABLED)) 593 continue; 594 if (c == dbg_io_ops->cons) 595 continue; 596 if (!c->write) 597 continue; 598 /* 599 * Set oops_in_progress to encourage the console drivers to 600 * disregard their internal spin locks: in the current calling 601 * context the risk of deadlock is a bigger problem than risks 602 * due to re-entering the console driver. We operate directly on 603 * oops_in_progress rather than using bust_spinlocks() because 604 * the calls bust_spinlocks() makes on exit are not appropriate 605 * for this calling context. 606 */ 607 ++oops_in_progress; 608 c->write(c, msg, msg_len); 609 --oops_in_progress; 610 touch_nmi_watchdog(); 611 } 612 console_srcu_read_unlock(cookie); 613 } 614 615 int vkdb_printf(enum kdb_msgsrc src, const char *fmt, va_list ap) 616 { 617 int diag; 618 int linecount; 619 int colcount; 620 int logging, saved_loglevel = 0; 621 int retlen = 0; 622 int fnd, len; 623 int this_cpu, old_cpu; 624 char *cp, *cp2, *cphold = NULL, replaced_byte = ' '; 625 char *moreprompt = "more> "; 626 unsigned long flags; 627 628 /* Serialize kdb_printf if multiple cpus try to write at once. 629 * But if any cpu goes recursive in kdb, just print the output, 630 * even if it is interleaved with any other text. 631 */ 632 local_irq_save(flags); 633 this_cpu = smp_processor_id(); 634 for (;;) { 635 old_cpu = cmpxchg(&kdb_printf_cpu, -1, this_cpu); 636 if (old_cpu == -1 || old_cpu == this_cpu) 637 break; 638 639 cpu_relax(); 640 } 641 642 diag = kdbgetintenv("LINES", &linecount); 643 if (diag || linecount <= 1) 644 linecount = 24; 645 646 diag = kdbgetintenv("COLUMNS", &colcount); 647 if (diag || colcount <= 1) 648 colcount = 80; 649 650 diag = kdbgetintenv("LOGGING", &logging); 651 if (diag) 652 logging = 0; 653 654 if (!kdb_grepping_flag || suspend_grep) { 655 /* normally, every vsnprintf starts a new buffer */ 656 next_avail = kdb_buffer; 657 size_avail = sizeof(kdb_buffer); 658 } 659 vsnprintf(next_avail, size_avail, fmt, ap); 660 661 /* 662 * If kdb_parse() found that the command was cmd xxx | grep yyy 663 * then kdb_grepping_flag is set, and kdb_grep_string contains yyy 664 * 665 * Accumulate the print data up to a newline before searching it. 666 * (vsnprintf does null-terminate the string that it generates) 667 */ 668 669 /* skip the search if prints are temporarily unconditional */ 670 if (!suspend_grep && kdb_grepping_flag) { 671 cp = strchr(kdb_buffer, '\n'); 672 if (!cp) { 673 /* 674 * Special cases that don't end with newlines 675 * but should be written without one: 676 * The "[nn]kdb> " prompt should 677 * appear at the front of the buffer. 678 * 679 * The "[nn]more " prompt should also be 680 * (MOREPROMPT -> moreprompt) 681 * written * but we print that ourselves, 682 * we set the suspend_grep flag to make 683 * it unconditional. 684 * 685 */ 686 if (next_avail == kdb_buffer) { 687 /* 688 * these should occur after a newline, 689 * so they will be at the front of the 690 * buffer 691 */ 692 cp2 = kdb_buffer; 693 len = strlen(kdb_prompt_str); 694 if (!strncmp(cp2, kdb_prompt_str, len)) { 695 /* 696 * We're about to start a new 697 * command, so we can go back 698 * to normal mode. 699 */ 700 kdb_grepping_flag = 0; 701 goto kdb_printit; 702 } 703 } 704 /* no newline; don't search/write the buffer 705 until one is there */ 706 len = strlen(kdb_buffer); 707 next_avail = kdb_buffer + len; 708 size_avail = sizeof(kdb_buffer) - len; 709 goto kdb_print_out; 710 } 711 712 /* 713 * The newline is present; print through it or discard 714 * it, depending on the results of the search. 715 */ 716 cp++; /* to byte after the newline */ 717 replaced_byte = *cp; /* remember what/where it was */ 718 cphold = cp; 719 *cp = '\0'; /* end the string for our search */ 720 721 /* 722 * We now have a newline at the end of the string 723 * Only continue with this output if it contains the 724 * search string. 725 */ 726 fnd = kdb_search_string(kdb_buffer, kdb_grep_string); 727 if (!fnd) { 728 /* 729 * At this point the complete line at the start 730 * of kdb_buffer can be discarded, as it does 731 * not contain what the user is looking for. 732 * Shift the buffer left. 733 */ 734 *cphold = replaced_byte; 735 strcpy(kdb_buffer, cphold); 736 len = strlen(kdb_buffer); 737 next_avail = kdb_buffer + len; 738 size_avail = sizeof(kdb_buffer) - len; 739 goto kdb_print_out; 740 } 741 if (kdb_grepping_flag >= KDB_GREPPING_FLAG_SEARCH) { 742 /* 743 * This was a interactive search (using '/' at more 744 * prompt) and it has completed. Replace the \0 with 745 * its original value to ensure multi-line strings 746 * are handled properly, and return to normal mode. 747 */ 748 *cphold = replaced_byte; 749 kdb_grepping_flag = 0; 750 } 751 /* 752 * at this point the string is a full line and 753 * should be printed, up to the null. 754 */ 755 } 756 kdb_printit: 757 758 /* 759 * Write to all consoles. 760 */ 761 retlen = strlen(kdb_buffer); 762 cp = (char *) printk_skip_headers(kdb_buffer); 763 if (!dbg_kdb_mode && kgdb_connected) 764 gdbstub_msg_write(cp, retlen - (cp - kdb_buffer)); 765 else 766 kdb_msg_write(cp, retlen - (cp - kdb_buffer)); 767 768 if (logging) { 769 saved_loglevel = console_loglevel; 770 console_loglevel = CONSOLE_LOGLEVEL_SILENT; 771 if (printk_get_level(kdb_buffer) || src == KDB_MSGSRC_PRINTK) 772 printk("%s", kdb_buffer); 773 else 774 pr_info("%s", kdb_buffer); 775 } 776 777 if (KDB_STATE(PAGER)) { 778 /* 779 * Check printed string to decide how to bump the 780 * kdb_nextline to control when the more prompt should 781 * show up. 782 */ 783 int got = 0; 784 len = retlen; 785 while (len--) { 786 if (kdb_buffer[len] == '\n') { 787 kdb_nextline++; 788 got = 0; 789 } else if (kdb_buffer[len] == '\r') { 790 got = 0; 791 } else { 792 got++; 793 } 794 } 795 kdb_nextline += got / (colcount + 1); 796 } 797 798 /* check for having reached the LINES number of printed lines */ 799 if (kdb_nextline >= linecount) { 800 char ch; 801 802 /* Watch out for recursion here. Any routine that calls 803 * kdb_printf will come back through here. And kdb_read 804 * uses kdb_printf to echo on serial consoles ... 805 */ 806 kdb_nextline = 1; /* In case of recursion */ 807 808 /* 809 * Pause until cr. 810 */ 811 moreprompt = kdbgetenv("MOREPROMPT"); 812 if (moreprompt == NULL) 813 moreprompt = "more> "; 814 815 kdb_input_flush(); 816 kdb_msg_write(moreprompt, strlen(moreprompt)); 817 818 if (logging) 819 printk("%s", moreprompt); 820 821 ch = kdb_getchar(); 822 kdb_nextline = 1; /* Really set output line 1 */ 823 824 /* empty and reset the buffer: */ 825 kdb_buffer[0] = '\0'; 826 next_avail = kdb_buffer; 827 size_avail = sizeof(kdb_buffer); 828 if ((ch == 'q') || (ch == 'Q')) { 829 /* user hit q or Q */ 830 KDB_FLAG_SET(CMD_INTERRUPT); /* command interrupted */ 831 KDB_STATE_CLEAR(PAGER); 832 /* end of command output; back to normal mode */ 833 kdb_grepping_flag = 0; 834 kdb_printf("\n"); 835 } else if (ch == ' ') { 836 kdb_printf("\r"); 837 suspend_grep = 1; /* for this recursion */ 838 } else if (ch == '\n' || ch == '\r') { 839 kdb_nextline = linecount - 1; 840 kdb_printf("\r"); 841 suspend_grep = 1; /* for this recursion */ 842 } else if (ch == '/' && !kdb_grepping_flag) { 843 kdb_printf("\r"); 844 kdb_getstr(kdb_grep_string, KDB_GREP_STRLEN, 845 kdbgetenv("SEARCHPROMPT") ?: "search> "); 846 *strchrnul(kdb_grep_string, '\n') = '\0'; 847 kdb_grepping_flag += KDB_GREPPING_FLAG_SEARCH; 848 suspend_grep = 1; /* for this recursion */ 849 } else if (ch) { 850 /* user hit something unexpected */ 851 suspend_grep = 1; /* for this recursion */ 852 if (ch != '/') 853 kdb_printf( 854 "\nOnly 'q', 'Q' or '/' are processed at " 855 "more prompt, input ignored\n"); 856 else 857 kdb_printf("\n'/' cannot be used during | " 858 "grep filtering, input ignored\n"); 859 } else if (kdb_grepping_flag) { 860 /* user hit enter */ 861 suspend_grep = 1; /* for this recursion */ 862 kdb_printf("\n"); 863 } 864 kdb_input_flush(); 865 } 866 867 /* 868 * For grep searches, shift the printed string left. 869 * replaced_byte contains the character that was overwritten with 870 * the terminating null, and cphold points to the null. 871 * Then adjust the notion of available space in the buffer. 872 */ 873 if (kdb_grepping_flag && !suspend_grep) { 874 *cphold = replaced_byte; 875 strcpy(kdb_buffer, cphold); 876 len = strlen(kdb_buffer); 877 next_avail = kdb_buffer + len; 878 size_avail = sizeof(kdb_buffer) - len; 879 } 880 881 kdb_print_out: 882 suspend_grep = 0; /* end of what may have been a recursive call */ 883 if (logging) 884 console_loglevel = saved_loglevel; 885 /* kdb_printf_cpu locked the code above. */ 886 smp_store_release(&kdb_printf_cpu, old_cpu); 887 local_irq_restore(flags); 888 return retlen; 889 } 890 891 int kdb_printf(const char *fmt, ...) 892 { 893 va_list ap; 894 int r; 895 896 va_start(ap, fmt); 897 r = vkdb_printf(KDB_MSGSRC_INTERNAL, fmt, ap); 898 va_end(ap); 899 900 return r; 901 } 902 EXPORT_SYMBOL_GPL(kdb_printf); 903