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_read 189 * 190 * This function reads a string of characters, terminated by 191 * a newline, or by reaching the end of the supplied buffer, 192 * from the current kernel debugger console device. 193 * Parameters: 194 * buffer - Address of character buffer to receive input characters. 195 * bufsize - size, in bytes, of the character buffer 196 * Returns: 197 * Returns a pointer to the buffer containing the received 198 * character string. This string will be terminated by a 199 * newline character. 200 * Locking: 201 * No locks are required to be held upon entry to this 202 * function. It is not reentrant - it relies on the fact 203 * that while kdb is running on only one "master debug" cpu. 204 * Remarks: 205 * The buffer size must be >= 2. 206 */ 207 208 static char *kdb_read(char *buffer, size_t bufsize) 209 { 210 char *cp = buffer; 211 char *bufend = buffer+bufsize-2; /* Reserve space for newline 212 * and null byte */ 213 char *lastchar; 214 char *p_tmp; 215 char tmp; 216 static char tmpbuffer[CMD_BUFLEN]; 217 int len = strlen(buffer); 218 int len_tmp; 219 int tab = 0; 220 int count; 221 int i; 222 int diag, dtab_count; 223 int key, buf_size, ret; 224 225 226 diag = kdbgetintenv("DTABCOUNT", &dtab_count); 227 if (diag) 228 dtab_count = 30; 229 230 if (len > 0) { 231 cp += len; 232 if (*(buffer+len-1) == '\n') 233 cp--; 234 } 235 236 lastchar = cp; 237 *cp = '\0'; 238 kdb_printf("%s", buffer); 239 poll_again: 240 key = kdb_getchar(); 241 if (key != 9) 242 tab = 0; 243 switch (key) { 244 case 8: /* backspace */ 245 if (cp > buffer) { 246 if (cp < lastchar) { 247 memcpy(tmpbuffer, cp, lastchar - cp); 248 memcpy(cp-1, tmpbuffer, lastchar - cp); 249 } 250 *(--lastchar) = '\0'; 251 --cp; 252 kdb_printf("\b%s \r", cp); 253 tmp = *cp; 254 *cp = '\0'; 255 kdb_printf(kdb_prompt_str); 256 kdb_printf("%s", buffer); 257 *cp = tmp; 258 } 259 break; 260 case 10: /* linefeed */ 261 case 13: /* carriage return */ 262 *lastchar++ = '\n'; 263 *lastchar++ = '\0'; 264 if (!KDB_STATE(KGDB_TRANS)) { 265 KDB_STATE_SET(KGDB_TRANS); 266 kdb_printf("%s", buffer); 267 } 268 kdb_printf("\n"); 269 return buffer; 270 case 4: /* Del */ 271 if (cp < lastchar) { 272 memcpy(tmpbuffer, cp+1, lastchar - cp - 1); 273 memcpy(cp, tmpbuffer, lastchar - cp - 1); 274 *(--lastchar) = '\0'; 275 kdb_printf("%s \r", cp); 276 tmp = *cp; 277 *cp = '\0'; 278 kdb_printf(kdb_prompt_str); 279 kdb_printf("%s", buffer); 280 *cp = tmp; 281 } 282 break; 283 case 1: /* Home */ 284 if (cp > buffer) { 285 kdb_printf("\r"); 286 kdb_printf(kdb_prompt_str); 287 cp = buffer; 288 } 289 break; 290 case 5: /* End */ 291 if (cp < lastchar) { 292 kdb_printf("%s", cp); 293 cp = lastchar; 294 } 295 break; 296 case 2: /* Left */ 297 if (cp > buffer) { 298 kdb_printf("\b"); 299 --cp; 300 } 301 break; 302 case 14: /* Down */ 303 memset(tmpbuffer, ' ', 304 strlen(kdb_prompt_str) + (lastchar-buffer)); 305 *(tmpbuffer+strlen(kdb_prompt_str) + 306 (lastchar-buffer)) = '\0'; 307 kdb_printf("\r%s\r", tmpbuffer); 308 *lastchar = (char)key; 309 *(lastchar+1) = '\0'; 310 return lastchar; 311 case 6: /* Right */ 312 if (cp < lastchar) { 313 kdb_printf("%c", *cp); 314 ++cp; 315 } 316 break; 317 case 16: /* Up */ 318 memset(tmpbuffer, ' ', 319 strlen(kdb_prompt_str) + (lastchar-buffer)); 320 *(tmpbuffer+strlen(kdb_prompt_str) + 321 (lastchar-buffer)) = '\0'; 322 kdb_printf("\r%s\r", tmpbuffer); 323 *lastchar = (char)key; 324 *(lastchar+1) = '\0'; 325 return lastchar; 326 case 9: /* Tab */ 327 if (tab < 2) 328 ++tab; 329 p_tmp = buffer; 330 while (*p_tmp == ' ') 331 p_tmp++; 332 if (p_tmp > cp) 333 break; 334 memcpy(tmpbuffer, p_tmp, cp-p_tmp); 335 *(tmpbuffer + (cp-p_tmp)) = '\0'; 336 p_tmp = strrchr(tmpbuffer, ' '); 337 if (p_tmp) 338 ++p_tmp; 339 else 340 p_tmp = tmpbuffer; 341 len = strlen(p_tmp); 342 buf_size = sizeof(tmpbuffer) - (p_tmp - tmpbuffer); 343 count = kallsyms_symbol_complete(p_tmp, buf_size); 344 if (tab == 2 && count > 0) { 345 kdb_printf("\n%d symbols are found.", count); 346 if (count > dtab_count) { 347 count = dtab_count; 348 kdb_printf(" But only first %d symbols will" 349 " be printed.\nYou can change the" 350 " environment variable DTABCOUNT.", 351 count); 352 } 353 kdb_printf("\n"); 354 for (i = 0; i < count; i++) { 355 ret = kallsyms_symbol_next(p_tmp, i, buf_size); 356 if (WARN_ON(!ret)) 357 break; 358 if (ret != -E2BIG) 359 kdb_printf("%s ", p_tmp); 360 else 361 kdb_printf("%s... ", p_tmp); 362 *(p_tmp + len) = '\0'; 363 } 364 if (i >= dtab_count) 365 kdb_printf("..."); 366 kdb_printf("\n"); 367 kdb_printf(kdb_prompt_str); 368 kdb_printf("%s", buffer); 369 } else if (tab != 2 && count > 0) { 370 len_tmp = strlen(p_tmp); 371 strncpy(p_tmp+len_tmp, cp, lastchar-cp+1); 372 len_tmp = strlen(p_tmp); 373 strncpy(cp, p_tmp+len, len_tmp-len + 1); 374 len = len_tmp - len; 375 kdb_printf("%s", cp); 376 cp += len; 377 lastchar += len; 378 } 379 kdb_nextline = 1; /* reset output line number */ 380 break; 381 default: 382 if (key >= 32 && lastchar < bufend) { 383 if (cp < lastchar) { 384 memcpy(tmpbuffer, cp, lastchar - cp); 385 memcpy(cp+1, tmpbuffer, lastchar - cp); 386 *++lastchar = '\0'; 387 *cp = key; 388 kdb_printf("%s\r", cp); 389 ++cp; 390 tmp = *cp; 391 *cp = '\0'; 392 kdb_printf(kdb_prompt_str); 393 kdb_printf("%s", buffer); 394 *cp = tmp; 395 } else { 396 *++lastchar = '\0'; 397 *cp++ = key; 398 /* The kgdb transition check will hide 399 * printed characters if we think that 400 * kgdb is connecting, until the check 401 * fails */ 402 if (!KDB_STATE(KGDB_TRANS)) { 403 if (kgdb_transition_check(buffer)) 404 return buffer; 405 } else { 406 kdb_printf("%c", key); 407 } 408 } 409 /* Special escape to kgdb */ 410 if (lastchar - buffer >= 5 && 411 strcmp(lastchar - 5, "$?#3f") == 0) { 412 kdb_gdb_state_pass(lastchar - 5); 413 strcpy(buffer, "kgdb"); 414 KDB_STATE_SET(DOING_KGDB); 415 return buffer; 416 } 417 if (lastchar - buffer >= 11 && 418 strcmp(lastchar - 11, "$qSupported") == 0) { 419 kdb_gdb_state_pass(lastchar - 11); 420 strcpy(buffer, "kgdb"); 421 KDB_STATE_SET(DOING_KGDB); 422 return buffer; 423 } 424 } 425 break; 426 } 427 goto poll_again; 428 } 429 430 /* 431 * kdb_getstr 432 * 433 * Print the prompt string and read a command from the 434 * input device. 435 * 436 * Parameters: 437 * buffer Address of buffer to receive command 438 * bufsize Size of buffer in bytes 439 * prompt Pointer to string to use as prompt string 440 * Returns: 441 * Pointer to command buffer. 442 * Locking: 443 * None. 444 * Remarks: 445 * For SMP kernels, the processor number will be 446 * substituted for %d, %x or %o in the prompt. 447 */ 448 449 char *kdb_getstr(char *buffer, size_t bufsize, const char *prompt) 450 { 451 if (prompt && kdb_prompt_str != prompt) 452 strscpy(kdb_prompt_str, prompt, CMD_BUFLEN); 453 kdb_printf(kdb_prompt_str); 454 kdb_nextline = 1; /* Prompt and input resets line number */ 455 return kdb_read(buffer, bufsize); 456 } 457 458 /* 459 * kdb_input_flush 460 * 461 * Get rid of any buffered console input. 462 * 463 * Parameters: 464 * none 465 * Returns: 466 * nothing 467 * Locking: 468 * none 469 * Remarks: 470 * Call this function whenever you want to flush input. If there is any 471 * outstanding input, it ignores all characters until there has been no 472 * data for approximately 1ms. 473 */ 474 475 static void kdb_input_flush(void) 476 { 477 get_char_func *f; 478 int res; 479 int flush_delay = 1; 480 while (flush_delay) { 481 flush_delay--; 482 empty: 483 touch_nmi_watchdog(); 484 for (f = &kdb_poll_funcs[0]; *f; ++f) { 485 res = (*f)(); 486 if (res != -1) { 487 flush_delay = 1; 488 goto empty; 489 } 490 } 491 if (flush_delay) 492 mdelay(1); 493 } 494 } 495 496 /* 497 * kdb_printf 498 * 499 * Print a string to the output device(s). 500 * 501 * Parameters: 502 * printf-like format and optional args. 503 * Returns: 504 * 0 505 * Locking: 506 * None. 507 * Remarks: 508 * use 'kdbcons->write()' to avoid polluting 'log_buf' with 509 * kdb output. 510 * 511 * If the user is doing a cmd args | grep srch 512 * then kdb_grepping_flag is set. 513 * In that case we need to accumulate full lines (ending in \n) before 514 * searching for the pattern. 515 */ 516 517 static char kdb_buffer[256]; /* A bit too big to go on stack */ 518 static char *next_avail = kdb_buffer; 519 static int size_avail; 520 static int suspend_grep; 521 522 /* 523 * search arg1 to see if it contains arg2 524 * (kdmain.c provides flags for ^pat and pat$) 525 * 526 * return 1 for found, 0 for not found 527 */ 528 static int kdb_search_string(char *searched, char *searchfor) 529 { 530 char firstchar, *cp; 531 int len1, len2; 532 533 /* not counting the newline at the end of "searched" */ 534 len1 = strlen(searched)-1; 535 len2 = strlen(searchfor); 536 if (len1 < len2) 537 return 0; 538 if (kdb_grep_leading && kdb_grep_trailing && len1 != len2) 539 return 0; 540 if (kdb_grep_leading) { 541 if (!strncmp(searched, searchfor, len2)) 542 return 1; 543 } else if (kdb_grep_trailing) { 544 if (!strncmp(searched+len1-len2, searchfor, len2)) 545 return 1; 546 } else { 547 firstchar = *searchfor; 548 cp = searched; 549 while ((cp = strchr(cp, firstchar))) { 550 if (!strncmp(cp, searchfor, len2)) 551 return 1; 552 cp++; 553 } 554 } 555 return 0; 556 } 557 558 static void kdb_msg_write(const char *msg, int msg_len) 559 { 560 struct console *c; 561 const char *cp; 562 int cookie; 563 int len; 564 565 if (msg_len == 0) 566 return; 567 568 cp = msg; 569 len = msg_len; 570 571 while (len--) { 572 dbg_io_ops->write_char(*cp); 573 cp++; 574 } 575 576 /* 577 * The console_srcu_read_lock() only provides safe console list 578 * traversal. The use of the ->write() callback relies on all other 579 * CPUs being stopped at the moment and console drivers being able to 580 * handle reentrance when @oops_in_progress is set. 581 * 582 * There is no guarantee that every console driver can handle 583 * reentrance in this way; the developer deploying the debugger 584 * is responsible for ensuring that the console drivers they 585 * have selected handle reentrance appropriately. 586 */ 587 cookie = console_srcu_read_lock(); 588 for_each_console_srcu(c) { 589 if (!(console_srcu_read_flags(c) & CON_ENABLED)) 590 continue; 591 if (c == dbg_io_ops->cons) 592 continue; 593 if (!c->write) 594 continue; 595 /* 596 * Set oops_in_progress to encourage the console drivers to 597 * disregard their internal spin locks: in the current calling 598 * context the risk of deadlock is a bigger problem than risks 599 * due to re-entering the console driver. We operate directly on 600 * oops_in_progress rather than using bust_spinlocks() because 601 * the calls bust_spinlocks() makes on exit are not appropriate 602 * for this calling context. 603 */ 604 ++oops_in_progress; 605 c->write(c, msg, msg_len); 606 --oops_in_progress; 607 touch_nmi_watchdog(); 608 } 609 console_srcu_read_unlock(cookie); 610 } 611 612 int vkdb_printf(enum kdb_msgsrc src, const char *fmt, va_list ap) 613 { 614 int diag; 615 int linecount; 616 int colcount; 617 int logging, saved_loglevel = 0; 618 int retlen = 0; 619 int fnd, len; 620 int this_cpu, old_cpu; 621 char *cp, *cp2, *cphold = NULL, replaced_byte = ' '; 622 char *moreprompt = "more> "; 623 unsigned long flags; 624 625 /* Serialize kdb_printf if multiple cpus try to write at once. 626 * But if any cpu goes recursive in kdb, just print the output, 627 * even if it is interleaved with any other text. 628 */ 629 local_irq_save(flags); 630 this_cpu = smp_processor_id(); 631 for (;;) { 632 old_cpu = cmpxchg(&kdb_printf_cpu, -1, this_cpu); 633 if (old_cpu == -1 || old_cpu == this_cpu) 634 break; 635 636 cpu_relax(); 637 } 638 639 diag = kdbgetintenv("LINES", &linecount); 640 if (diag || linecount <= 1) 641 linecount = 24; 642 643 diag = kdbgetintenv("COLUMNS", &colcount); 644 if (diag || colcount <= 1) 645 colcount = 80; 646 647 diag = kdbgetintenv("LOGGING", &logging); 648 if (diag) 649 logging = 0; 650 651 if (!kdb_grepping_flag || suspend_grep) { 652 /* normally, every vsnprintf starts a new buffer */ 653 next_avail = kdb_buffer; 654 size_avail = sizeof(kdb_buffer); 655 } 656 vsnprintf(next_avail, size_avail, fmt, ap); 657 658 /* 659 * If kdb_parse() found that the command was cmd xxx | grep yyy 660 * then kdb_grepping_flag is set, and kdb_grep_string contains yyy 661 * 662 * Accumulate the print data up to a newline before searching it. 663 * (vsnprintf does null-terminate the string that it generates) 664 */ 665 666 /* skip the search if prints are temporarily unconditional */ 667 if (!suspend_grep && kdb_grepping_flag) { 668 cp = strchr(kdb_buffer, '\n'); 669 if (!cp) { 670 /* 671 * Special cases that don't end with newlines 672 * but should be written without one: 673 * The "[nn]kdb> " prompt should 674 * appear at the front of the buffer. 675 * 676 * The "[nn]more " prompt should also be 677 * (MOREPROMPT -> moreprompt) 678 * written * but we print that ourselves, 679 * we set the suspend_grep flag to make 680 * it unconditional. 681 * 682 */ 683 if (next_avail == kdb_buffer) { 684 /* 685 * these should occur after a newline, 686 * so they will be at the front of the 687 * buffer 688 */ 689 cp2 = kdb_buffer; 690 len = strlen(kdb_prompt_str); 691 if (!strncmp(cp2, kdb_prompt_str, len)) { 692 /* 693 * We're about to start a new 694 * command, so we can go back 695 * to normal mode. 696 */ 697 kdb_grepping_flag = 0; 698 goto kdb_printit; 699 } 700 } 701 /* no newline; don't search/write the buffer 702 until one is there */ 703 len = strlen(kdb_buffer); 704 next_avail = kdb_buffer + len; 705 size_avail = sizeof(kdb_buffer) - len; 706 goto kdb_print_out; 707 } 708 709 /* 710 * The newline is present; print through it or discard 711 * it, depending on the results of the search. 712 */ 713 cp++; /* to byte after the newline */ 714 replaced_byte = *cp; /* remember what/where it was */ 715 cphold = cp; 716 *cp = '\0'; /* end the string for our search */ 717 718 /* 719 * We now have a newline at the end of the string 720 * Only continue with this output if it contains the 721 * search string. 722 */ 723 fnd = kdb_search_string(kdb_buffer, kdb_grep_string); 724 if (!fnd) { 725 /* 726 * At this point the complete line at the start 727 * of kdb_buffer can be discarded, as it does 728 * not contain what the user is looking for. 729 * Shift the buffer left. 730 */ 731 *cphold = replaced_byte; 732 strcpy(kdb_buffer, cphold); 733 len = strlen(kdb_buffer); 734 next_avail = kdb_buffer + len; 735 size_avail = sizeof(kdb_buffer) - len; 736 goto kdb_print_out; 737 } 738 if (kdb_grepping_flag >= KDB_GREPPING_FLAG_SEARCH) { 739 /* 740 * This was a interactive search (using '/' at more 741 * prompt) and it has completed. Replace the \0 with 742 * its original value to ensure multi-line strings 743 * are handled properly, and return to normal mode. 744 */ 745 *cphold = replaced_byte; 746 kdb_grepping_flag = 0; 747 } 748 /* 749 * at this point the string is a full line and 750 * should be printed, up to the null. 751 */ 752 } 753 kdb_printit: 754 755 /* 756 * Write to all consoles. 757 */ 758 retlen = strlen(kdb_buffer); 759 cp = (char *) printk_skip_headers(kdb_buffer); 760 if (!dbg_kdb_mode && kgdb_connected) 761 gdbstub_msg_write(cp, retlen - (cp - kdb_buffer)); 762 else 763 kdb_msg_write(cp, retlen - (cp - kdb_buffer)); 764 765 if (logging) { 766 saved_loglevel = console_loglevel; 767 console_loglevel = CONSOLE_LOGLEVEL_SILENT; 768 if (printk_get_level(kdb_buffer) || src == KDB_MSGSRC_PRINTK) 769 printk("%s", kdb_buffer); 770 else 771 pr_info("%s", kdb_buffer); 772 } 773 774 if (KDB_STATE(PAGER)) { 775 /* 776 * Check printed string to decide how to bump the 777 * kdb_nextline to control when the more prompt should 778 * show up. 779 */ 780 int got = 0; 781 len = retlen; 782 while (len--) { 783 if (kdb_buffer[len] == '\n') { 784 kdb_nextline++; 785 got = 0; 786 } else if (kdb_buffer[len] == '\r') { 787 got = 0; 788 } else { 789 got++; 790 } 791 } 792 kdb_nextline += got / (colcount + 1); 793 } 794 795 /* check for having reached the LINES number of printed lines */ 796 if (kdb_nextline >= linecount) { 797 char ch; 798 799 /* Watch out for recursion here. Any routine that calls 800 * kdb_printf will come back through here. And kdb_read 801 * uses kdb_printf to echo on serial consoles ... 802 */ 803 kdb_nextline = 1; /* In case of recursion */ 804 805 /* 806 * Pause until cr. 807 */ 808 moreprompt = kdbgetenv("MOREPROMPT"); 809 if (moreprompt == NULL) 810 moreprompt = "more> "; 811 812 kdb_input_flush(); 813 kdb_msg_write(moreprompt, strlen(moreprompt)); 814 815 if (logging) 816 printk("%s", moreprompt); 817 818 ch = kdb_getchar(); 819 kdb_nextline = 1; /* Really set output line 1 */ 820 821 /* empty and reset the buffer: */ 822 kdb_buffer[0] = '\0'; 823 next_avail = kdb_buffer; 824 size_avail = sizeof(kdb_buffer); 825 if ((ch == 'q') || (ch == 'Q')) { 826 /* user hit q or Q */ 827 KDB_FLAG_SET(CMD_INTERRUPT); /* command interrupted */ 828 KDB_STATE_CLEAR(PAGER); 829 /* end of command output; back to normal mode */ 830 kdb_grepping_flag = 0; 831 kdb_printf("\n"); 832 } else if (ch == ' ') { 833 kdb_printf("\r"); 834 suspend_grep = 1; /* for this recursion */ 835 } else if (ch == '\n' || ch == '\r') { 836 kdb_nextline = linecount - 1; 837 kdb_printf("\r"); 838 suspend_grep = 1; /* for this recursion */ 839 } else if (ch == '/' && !kdb_grepping_flag) { 840 kdb_printf("\r"); 841 kdb_getstr(kdb_grep_string, KDB_GREP_STRLEN, 842 kdbgetenv("SEARCHPROMPT") ?: "search> "); 843 *strchrnul(kdb_grep_string, '\n') = '\0'; 844 kdb_grepping_flag += KDB_GREPPING_FLAG_SEARCH; 845 suspend_grep = 1; /* for this recursion */ 846 } else if (ch) { 847 /* user hit something unexpected */ 848 suspend_grep = 1; /* for this recursion */ 849 if (ch != '/') 850 kdb_printf( 851 "\nOnly 'q', 'Q' or '/' are processed at " 852 "more prompt, input ignored\n"); 853 else 854 kdb_printf("\n'/' cannot be used during | " 855 "grep filtering, input ignored\n"); 856 } else if (kdb_grepping_flag) { 857 /* user hit enter */ 858 suspend_grep = 1; /* for this recursion */ 859 kdb_printf("\n"); 860 } 861 kdb_input_flush(); 862 } 863 864 /* 865 * For grep searches, shift the printed string left. 866 * replaced_byte contains the character that was overwritten with 867 * the terminating null, and cphold points to the null. 868 * Then adjust the notion of available space in the buffer. 869 */ 870 if (kdb_grepping_flag && !suspend_grep) { 871 *cphold = replaced_byte; 872 strcpy(kdb_buffer, cphold); 873 len = strlen(kdb_buffer); 874 next_avail = kdb_buffer + len; 875 size_avail = sizeof(kdb_buffer) - len; 876 } 877 878 kdb_print_out: 879 suspend_grep = 0; /* end of what may have been a recursive call */ 880 if (logging) 881 console_loglevel = saved_loglevel; 882 /* kdb_printf_cpu locked the code above. */ 883 smp_store_release(&kdb_printf_cpu, old_cpu); 884 local_irq_restore(flags); 885 return retlen; 886 } 887 888 int kdb_printf(const char *fmt, ...) 889 { 890 va_list ap; 891 int r; 892 893 va_start(ap, fmt); 894 r = vkdb_printf(KDB_MSGSRC_INTERNAL, fmt, ap); 895 va_end(ap); 896 897 return r; 898 } 899 EXPORT_SYMBOL_GPL(kdb_printf); 900