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", kdb_prompt_str); 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 static char tmpbuffer[CMD_BUFLEN]; 243 int len = strlen(buffer); 244 int len_tmp; 245 int tab = 0; 246 int count; 247 int i; 248 int diag, dtab_count; 249 int key, buf_size, ret; 250 251 252 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 p_tmp = buffer; 333 while (*p_tmp == ' ') 334 p_tmp++; 335 if (p_tmp > cp) 336 break; 337 memcpy(tmpbuffer, p_tmp, cp-p_tmp); 338 *(tmpbuffer + (cp-p_tmp)) = '\0'; 339 p_tmp = strrchr(tmpbuffer, ' '); 340 if (p_tmp) 341 ++p_tmp; 342 else 343 p_tmp = tmpbuffer; 344 len = strlen(p_tmp); 345 buf_size = sizeof(tmpbuffer) - (p_tmp - tmpbuffer); 346 count = kallsyms_symbol_complete(p_tmp, buf_size); 347 if (tab == 2 && count > 0) { 348 kdb_printf("\n%d symbols are found.", count); 349 if (count > dtab_count) { 350 count = dtab_count; 351 kdb_printf(" But only first %d symbols will" 352 " be printed.\nYou can change the" 353 " environment variable DTABCOUNT.", 354 count); 355 } 356 kdb_printf("\n"); 357 for (i = 0; i < count; i++) { 358 ret = kallsyms_symbol_next(p_tmp, i, buf_size); 359 if (WARN_ON(!ret)) 360 break; 361 if (ret != -E2BIG) 362 kdb_printf("%s ", p_tmp); 363 else 364 kdb_printf("%s... ", p_tmp); 365 *(p_tmp + len) = '\0'; 366 } 367 if (i >= dtab_count) 368 kdb_printf("..."); 369 kdb_printf("\n"); 370 kdb_printf(kdb_prompt_str); 371 kdb_printf("%s", buffer); 372 if (cp != lastchar) 373 kdb_position_cursor(kdb_prompt_str, buffer, cp); 374 } else if (tab != 2 && count > 0) { 375 /* How many new characters do we want from tmpbuffer? */ 376 len_tmp = strlen(p_tmp) - len; 377 if (lastchar + len_tmp >= bufend) 378 len_tmp = bufend - lastchar; 379 380 if (len_tmp) { 381 /* + 1 ensures the '\0' is memmove'd */ 382 memmove(cp+len_tmp, cp, (lastchar-cp) + 1); 383 memcpy(cp, p_tmp+len, len_tmp); 384 kdb_printf("%s", cp); 385 cp += len_tmp; 386 lastchar += len_tmp; 387 if (cp != lastchar) 388 kdb_position_cursor(kdb_prompt_str, 389 buffer, cp); 390 } 391 } 392 kdb_nextline = 1; /* reset output line number */ 393 break; 394 default: 395 if (key >= 32 && lastchar < bufend) { 396 if (cp < lastchar) { 397 memmove(cp+1, cp, lastchar - cp + 1); 398 lastchar++; 399 *cp = key; 400 kdb_printf("%s", cp); 401 ++cp; 402 kdb_position_cursor(kdb_prompt_str, buffer, cp); 403 } else { 404 *++lastchar = '\0'; 405 *cp++ = key; 406 /* The kgdb transition check will hide 407 * printed characters if we think that 408 * kgdb is connecting, until the check 409 * fails */ 410 if (!KDB_STATE(KGDB_TRANS)) { 411 if (kgdb_transition_check(buffer)) 412 return buffer; 413 } else { 414 kdb_printf("%c", key); 415 } 416 } 417 /* Special escape to kgdb */ 418 if (lastchar - buffer >= 5 && 419 strcmp(lastchar - 5, "$?#3f") == 0) { 420 kdb_gdb_state_pass(lastchar - 5); 421 strcpy(buffer, "kgdb"); 422 KDB_STATE_SET(DOING_KGDB); 423 return buffer; 424 } 425 if (lastchar - buffer >= 11 && 426 strcmp(lastchar - 11, "$qSupported") == 0) { 427 kdb_gdb_state_pass(lastchar - 11); 428 strcpy(buffer, "kgdb"); 429 KDB_STATE_SET(DOING_KGDB); 430 return buffer; 431 } 432 } 433 break; 434 } 435 goto poll_again; 436 } 437 438 /* 439 * kdb_getstr 440 * 441 * Print the prompt string and read a command from the 442 * input device. 443 * 444 * Parameters: 445 * buffer Address of buffer to receive command 446 * bufsize Size of buffer in bytes 447 * prompt Pointer to string to use as prompt string 448 * Returns: 449 * Pointer to command buffer. 450 * Locking: 451 * None. 452 * Remarks: 453 * For SMP kernels, the processor number will be 454 * substituted for %d, %x or %o in the prompt. 455 */ 456 457 char *kdb_getstr(char *buffer, size_t bufsize, const char *prompt) 458 { 459 if (prompt && kdb_prompt_str != prompt) 460 strscpy(kdb_prompt_str, prompt, CMD_BUFLEN); 461 kdb_printf(kdb_prompt_str); 462 kdb_nextline = 1; /* Prompt and input resets line number */ 463 return kdb_read(buffer, bufsize); 464 } 465 466 /* 467 * kdb_input_flush 468 * 469 * Get rid of any buffered console input. 470 * 471 * Parameters: 472 * none 473 * Returns: 474 * nothing 475 * Locking: 476 * none 477 * Remarks: 478 * Call this function whenever you want to flush input. If there is any 479 * outstanding input, it ignores all characters until there has been no 480 * data for approximately 1ms. 481 */ 482 483 static void kdb_input_flush(void) 484 { 485 get_char_func *f; 486 int res; 487 int flush_delay = 1; 488 while (flush_delay) { 489 flush_delay--; 490 empty: 491 touch_nmi_watchdog(); 492 for (f = &kdb_poll_funcs[0]; *f; ++f) { 493 res = (*f)(); 494 if (res != -1) { 495 flush_delay = 1; 496 goto empty; 497 } 498 } 499 if (flush_delay) 500 mdelay(1); 501 } 502 } 503 504 /* 505 * kdb_printf 506 * 507 * Print a string to the output device(s). 508 * 509 * Parameters: 510 * printf-like format and optional args. 511 * Returns: 512 * 0 513 * Locking: 514 * None. 515 * Remarks: 516 * use 'kdbcons->write()' to avoid polluting 'log_buf' with 517 * kdb output. 518 * 519 * If the user is doing a cmd args | grep srch 520 * then kdb_grepping_flag is set. 521 * In that case we need to accumulate full lines (ending in \n) before 522 * searching for the pattern. 523 */ 524 525 static char kdb_buffer[256]; /* A bit too big to go on stack */ 526 static char *next_avail = kdb_buffer; 527 static int size_avail; 528 static int suspend_grep; 529 530 /* 531 * search arg1 to see if it contains arg2 532 * (kdmain.c provides flags for ^pat and pat$) 533 * 534 * return 1 for found, 0 for not found 535 */ 536 static int kdb_search_string(char *searched, char *searchfor) 537 { 538 char firstchar, *cp; 539 int len1, len2; 540 541 /* not counting the newline at the end of "searched" */ 542 len1 = strlen(searched)-1; 543 len2 = strlen(searchfor); 544 if (len1 < len2) 545 return 0; 546 if (kdb_grep_leading && kdb_grep_trailing && len1 != len2) 547 return 0; 548 if (kdb_grep_leading) { 549 if (!strncmp(searched, searchfor, len2)) 550 return 1; 551 } else if (kdb_grep_trailing) { 552 if (!strncmp(searched+len1-len2, searchfor, len2)) 553 return 1; 554 } else { 555 firstchar = *searchfor; 556 cp = searched; 557 while ((cp = strchr(cp, firstchar))) { 558 if (!strncmp(cp, searchfor, len2)) 559 return 1; 560 cp++; 561 } 562 } 563 return 0; 564 } 565 566 static void kdb_msg_write(const char *msg, int msg_len) 567 { 568 struct console *c; 569 const char *cp; 570 int cookie; 571 int len; 572 573 if (msg_len == 0) 574 return; 575 576 cp = msg; 577 len = msg_len; 578 579 while (len--) { 580 dbg_io_ops->write_char(*cp); 581 cp++; 582 } 583 584 /* 585 * The console_srcu_read_lock() only provides safe console list 586 * traversal. The use of the ->write() callback relies on all other 587 * CPUs being stopped at the moment and console drivers being able to 588 * handle reentrance when @oops_in_progress is set. 589 * 590 * There is no guarantee that every console driver can handle 591 * reentrance in this way; the developer deploying the debugger 592 * is responsible for ensuring that the console drivers they 593 * have selected handle reentrance appropriately. 594 */ 595 cookie = console_srcu_read_lock(); 596 for_each_console_srcu(c) { 597 if (!(console_srcu_read_flags(c) & CON_ENABLED)) 598 continue; 599 if (c == dbg_io_ops->cons) 600 continue; 601 if (!c->write) 602 continue; 603 /* 604 * Set oops_in_progress to encourage the console drivers to 605 * disregard their internal spin locks: in the current calling 606 * context the risk of deadlock is a bigger problem than risks 607 * due to re-entering the console driver. We operate directly on 608 * oops_in_progress rather than using bust_spinlocks() because 609 * the calls bust_spinlocks() makes on exit are not appropriate 610 * for this calling context. 611 */ 612 ++oops_in_progress; 613 c->write(c, msg, msg_len); 614 --oops_in_progress; 615 touch_nmi_watchdog(); 616 } 617 console_srcu_read_unlock(cookie); 618 } 619 620 int vkdb_printf(enum kdb_msgsrc src, const char *fmt, va_list ap) 621 { 622 int diag; 623 int linecount; 624 int colcount; 625 int logging, saved_loglevel = 0; 626 int retlen = 0; 627 int fnd, len; 628 int this_cpu, old_cpu; 629 char *cp, *cp2, *cphold = NULL, replaced_byte = ' '; 630 char *moreprompt = "more> "; 631 unsigned long flags; 632 633 /* Serialize kdb_printf if multiple cpus try to write at once. 634 * But if any cpu goes recursive in kdb, just print the output, 635 * even if it is interleaved with any other text. 636 */ 637 local_irq_save(flags); 638 this_cpu = smp_processor_id(); 639 for (;;) { 640 old_cpu = cmpxchg(&kdb_printf_cpu, -1, this_cpu); 641 if (old_cpu == -1 || old_cpu == this_cpu) 642 break; 643 644 cpu_relax(); 645 } 646 647 diag = kdbgetintenv("LINES", &linecount); 648 if (diag || linecount <= 1) 649 linecount = 24; 650 651 diag = kdbgetintenv("COLUMNS", &colcount); 652 if (diag || colcount <= 1) 653 colcount = 80; 654 655 diag = kdbgetintenv("LOGGING", &logging); 656 if (diag) 657 logging = 0; 658 659 if (!kdb_grepping_flag || suspend_grep) { 660 /* normally, every vsnprintf starts a new buffer */ 661 next_avail = kdb_buffer; 662 size_avail = sizeof(kdb_buffer); 663 } 664 vsnprintf(next_avail, size_avail, fmt, ap); 665 666 /* 667 * If kdb_parse() found that the command was cmd xxx | grep yyy 668 * then kdb_grepping_flag is set, and kdb_grep_string contains yyy 669 * 670 * Accumulate the print data up to a newline before searching it. 671 * (vsnprintf does null-terminate the string that it generates) 672 */ 673 674 /* skip the search if prints are temporarily unconditional */ 675 if (!suspend_grep && kdb_grepping_flag) { 676 cp = strchr(kdb_buffer, '\n'); 677 if (!cp) { 678 /* 679 * Special cases that don't end with newlines 680 * but should be written without one: 681 * The "[nn]kdb> " prompt should 682 * appear at the front of the buffer. 683 * 684 * The "[nn]more " prompt should also be 685 * (MOREPROMPT -> moreprompt) 686 * written * but we print that ourselves, 687 * we set the suspend_grep flag to make 688 * it unconditional. 689 * 690 */ 691 if (next_avail == kdb_buffer) { 692 /* 693 * these should occur after a newline, 694 * so they will be at the front of the 695 * buffer 696 */ 697 cp2 = kdb_buffer; 698 len = strlen(kdb_prompt_str); 699 if (!strncmp(cp2, kdb_prompt_str, len)) { 700 /* 701 * We're about to start a new 702 * command, so we can go back 703 * to normal mode. 704 */ 705 kdb_grepping_flag = 0; 706 goto kdb_printit; 707 } 708 } 709 /* no newline; don't search/write the buffer 710 until one is there */ 711 len = strlen(kdb_buffer); 712 next_avail = kdb_buffer + len; 713 size_avail = sizeof(kdb_buffer) - len; 714 goto kdb_print_out; 715 } 716 717 /* 718 * The newline is present; print through it or discard 719 * it, depending on the results of the search. 720 */ 721 cp++; /* to byte after the newline */ 722 replaced_byte = *cp; /* remember what/where it was */ 723 cphold = cp; 724 *cp = '\0'; /* end the string for our search */ 725 726 /* 727 * We now have a newline at the end of the string 728 * Only continue with this output if it contains the 729 * search string. 730 */ 731 fnd = kdb_search_string(kdb_buffer, kdb_grep_string); 732 if (!fnd) { 733 /* 734 * At this point the complete line at the start 735 * of kdb_buffer can be discarded, as it does 736 * not contain what the user is looking for. 737 * Shift the buffer left. 738 */ 739 *cphold = replaced_byte; 740 strcpy(kdb_buffer, cphold); 741 len = strlen(kdb_buffer); 742 next_avail = kdb_buffer + len; 743 size_avail = sizeof(kdb_buffer) - len; 744 goto kdb_print_out; 745 } 746 if (kdb_grepping_flag >= KDB_GREPPING_FLAG_SEARCH) { 747 /* 748 * This was a interactive search (using '/' at more 749 * prompt) and it has completed. Replace the \0 with 750 * its original value to ensure multi-line strings 751 * are handled properly, and return to normal mode. 752 */ 753 *cphold = replaced_byte; 754 kdb_grepping_flag = 0; 755 } 756 /* 757 * at this point the string is a full line and 758 * should be printed, up to the null. 759 */ 760 } 761 kdb_printit: 762 763 /* 764 * Write to all consoles. 765 */ 766 retlen = strlen(kdb_buffer); 767 cp = (char *) printk_skip_headers(kdb_buffer); 768 if (!dbg_kdb_mode && kgdb_connected) 769 gdbstub_msg_write(cp, retlen - (cp - kdb_buffer)); 770 else 771 kdb_msg_write(cp, retlen - (cp - kdb_buffer)); 772 773 if (logging) { 774 saved_loglevel = console_loglevel; 775 console_loglevel = CONSOLE_LOGLEVEL_SILENT; 776 if (printk_get_level(kdb_buffer) || src == KDB_MSGSRC_PRINTK) 777 printk("%s", kdb_buffer); 778 else 779 pr_info("%s", kdb_buffer); 780 } 781 782 if (KDB_STATE(PAGER)) { 783 /* 784 * Check printed string to decide how to bump the 785 * kdb_nextline to control when the more prompt should 786 * show up. 787 */ 788 int got = 0; 789 len = retlen; 790 while (len--) { 791 if (kdb_buffer[len] == '\n') { 792 kdb_nextline++; 793 got = 0; 794 } else if (kdb_buffer[len] == '\r') { 795 got = 0; 796 } else { 797 got++; 798 } 799 } 800 kdb_nextline += got / (colcount + 1); 801 } 802 803 /* check for having reached the LINES number of printed lines */ 804 if (kdb_nextline >= linecount) { 805 char ch; 806 807 /* Watch out for recursion here. Any routine that calls 808 * kdb_printf will come back through here. And kdb_read 809 * uses kdb_printf to echo on serial consoles ... 810 */ 811 kdb_nextline = 1; /* In case of recursion */ 812 813 /* 814 * Pause until cr. 815 */ 816 moreprompt = kdbgetenv("MOREPROMPT"); 817 if (moreprompt == NULL) 818 moreprompt = "more> "; 819 820 kdb_input_flush(); 821 kdb_msg_write(moreprompt, strlen(moreprompt)); 822 823 if (logging) 824 printk("%s", moreprompt); 825 826 ch = kdb_getchar(); 827 kdb_nextline = 1; /* Really set output line 1 */ 828 829 /* empty and reset the buffer: */ 830 kdb_buffer[0] = '\0'; 831 next_avail = kdb_buffer; 832 size_avail = sizeof(kdb_buffer); 833 if ((ch == 'q') || (ch == 'Q')) { 834 /* user hit q or Q */ 835 KDB_FLAG_SET(CMD_INTERRUPT); /* command interrupted */ 836 KDB_STATE_CLEAR(PAGER); 837 /* end of command output; back to normal mode */ 838 kdb_grepping_flag = 0; 839 kdb_printf("\n"); 840 } else if (ch == ' ') { 841 kdb_printf("\r"); 842 suspend_grep = 1; /* for this recursion */ 843 } else if (ch == '\n' || ch == '\r') { 844 kdb_nextline = linecount - 1; 845 kdb_printf("\r"); 846 suspend_grep = 1; /* for this recursion */ 847 } else if (ch == '/' && !kdb_grepping_flag) { 848 kdb_printf("\r"); 849 kdb_getstr(kdb_grep_string, KDB_GREP_STRLEN, 850 kdbgetenv("SEARCHPROMPT") ?: "search> "); 851 *strchrnul(kdb_grep_string, '\n') = '\0'; 852 kdb_grepping_flag += KDB_GREPPING_FLAG_SEARCH; 853 suspend_grep = 1; /* for this recursion */ 854 } else if (ch) { 855 /* user hit something unexpected */ 856 suspend_grep = 1; /* for this recursion */ 857 if (ch != '/') 858 kdb_printf( 859 "\nOnly 'q', 'Q' or '/' are processed at " 860 "more prompt, input ignored\n"); 861 else 862 kdb_printf("\n'/' cannot be used during | " 863 "grep filtering, input ignored\n"); 864 } else if (kdb_grepping_flag) { 865 /* user hit enter */ 866 suspend_grep = 1; /* for this recursion */ 867 kdb_printf("\n"); 868 } 869 kdb_input_flush(); 870 } 871 872 /* 873 * For grep searches, shift the printed string left. 874 * replaced_byte contains the character that was overwritten with 875 * the terminating null, and cphold points to the null. 876 * Then adjust the notion of available space in the buffer. 877 */ 878 if (kdb_grepping_flag && !suspend_grep) { 879 *cphold = replaced_byte; 880 strcpy(kdb_buffer, cphold); 881 len = strlen(kdb_buffer); 882 next_avail = kdb_buffer + len; 883 size_avail = sizeof(kdb_buffer) - len; 884 } 885 886 kdb_print_out: 887 suspend_grep = 0; /* end of what may have been a recursive call */ 888 if (logging) 889 console_loglevel = saved_loglevel; 890 /* kdb_printf_cpu locked the code above. */ 891 smp_store_release(&kdb_printf_cpu, old_cpu); 892 local_irq_restore(flags); 893 return retlen; 894 } 895 896 int kdb_printf(const char *fmt, ...) 897 { 898 va_list ap; 899 int r; 900 901 va_start(ap, fmt); 902 r = vkdb_printf(KDB_MSGSRC_INTERNAL, fmt, ap); 903 va_end(ap); 904 905 return r; 906 } 907 EXPORT_SYMBOL_GPL(kdb_printf); 908