Jason Wessel | dc7d552 | 2008-04-17 20:05:37 +0200 | [diff] [blame] | 1 | /* |
| 2 | * KGDB stub. |
| 3 | * |
| 4 | * Maintainer: Jason Wessel <jason.wessel@windriver.com> |
| 5 | * |
| 6 | * Copyright (C) 2000-2001 VERITAS Software Corporation. |
| 7 | * Copyright (C) 2002-2004 Timesys Corporation |
| 8 | * Copyright (C) 2003-2004 Amit S. Kale <amitkale@linsyssoft.com> |
| 9 | * Copyright (C) 2004 Pavel Machek <pavel@suse.cz> |
| 10 | * Copyright (C) 2004-2006 Tom Rini <trini@kernel.crashing.org> |
| 11 | * Copyright (C) 2004-2006 LinSysSoft Technologies Pvt. Ltd. |
| 12 | * Copyright (C) 2005-2008 Wind River Systems, Inc. |
| 13 | * Copyright (C) 2007 MontaVista Software, Inc. |
| 14 | * Copyright (C) 2008 Red Hat, Inc., Ingo Molnar <mingo@redhat.com> |
| 15 | * |
| 16 | * Contributors at various stages not listed above: |
| 17 | * Jason Wessel ( jason.wessel@windriver.com ) |
| 18 | * George Anzinger <george@mvista.com> |
| 19 | * Anurekh Saxena (anurekh.saxena@timesys.com) |
| 20 | * Lake Stevens Instrument Division (Glenn Engel) |
| 21 | * Jim Kingdon, Cygnus Support. |
| 22 | * |
| 23 | * Original KGDB stub: David Grothe <dave@gcom.com>, |
| 24 | * Tigran Aivazian <tigran@sco.com> |
| 25 | * |
| 26 | * This file is licensed under the terms of the GNU General Public License |
| 27 | * version 2. This program is licensed "as is" without any warranty of any |
| 28 | * kind, whether express or implied. |
| 29 | */ |
| 30 | #include <linux/pid_namespace.h> |
Jason Wessel | 7c3078b | 2008-02-15 14:55:54 -0600 | [diff] [blame] | 31 | #include <linux/clocksource.h> |
Jason Wessel | dc7d552 | 2008-04-17 20:05:37 +0200 | [diff] [blame] | 32 | #include <linux/interrupt.h> |
| 33 | #include <linux/spinlock.h> |
| 34 | #include <linux/console.h> |
| 35 | #include <linux/threads.h> |
| 36 | #include <linux/uaccess.h> |
| 37 | #include <linux/kernel.h> |
| 38 | #include <linux/module.h> |
| 39 | #include <linux/ptrace.h> |
| 40 | #include <linux/reboot.h> |
| 41 | #include <linux/string.h> |
| 42 | #include <linux/delay.h> |
| 43 | #include <linux/sched.h> |
| 44 | #include <linux/sysrq.h> |
| 45 | #include <linux/init.h> |
| 46 | #include <linux/kgdb.h> |
| 47 | #include <linux/pid.h> |
| 48 | #include <linux/smp.h> |
| 49 | #include <linux/mm.h> |
| 50 | |
| 51 | #include <asm/cacheflush.h> |
| 52 | #include <asm/byteorder.h> |
| 53 | #include <asm/atomic.h> |
| 54 | #include <asm/system.h> |
| 55 | |
| 56 | static int kgdb_break_asap; |
| 57 | |
| 58 | struct kgdb_state { |
| 59 | int ex_vector; |
| 60 | int signo; |
| 61 | int err_code; |
| 62 | int cpu; |
| 63 | int pass_exception; |
| 64 | long threadid; |
| 65 | long kgdb_usethreadid; |
| 66 | struct pt_regs *linux_regs; |
| 67 | }; |
| 68 | |
| 69 | static struct debuggerinfo_struct { |
| 70 | void *debuggerinfo; |
| 71 | struct task_struct *task; |
| 72 | } kgdb_info[NR_CPUS]; |
| 73 | |
| 74 | /** |
| 75 | * kgdb_connected - Is a host GDB connected to us? |
| 76 | */ |
| 77 | int kgdb_connected; |
| 78 | EXPORT_SYMBOL_GPL(kgdb_connected); |
| 79 | |
| 80 | /* All the KGDB handlers are installed */ |
| 81 | static int kgdb_io_module_registered; |
| 82 | |
| 83 | /* Guard for recursive entry */ |
| 84 | static int exception_level; |
| 85 | |
| 86 | static struct kgdb_io *kgdb_io_ops; |
| 87 | static DEFINE_SPINLOCK(kgdb_registration_lock); |
| 88 | |
| 89 | /* kgdb console driver is loaded */ |
| 90 | static int kgdb_con_registered; |
| 91 | /* determine if kgdb console output should be used */ |
| 92 | static int kgdb_use_con; |
| 93 | |
| 94 | static int __init opt_kgdb_con(char *str) |
| 95 | { |
| 96 | kgdb_use_con = 1; |
| 97 | return 0; |
| 98 | } |
| 99 | |
| 100 | early_param("kgdbcon", opt_kgdb_con); |
| 101 | |
| 102 | module_param(kgdb_use_con, int, 0644); |
| 103 | |
| 104 | /* |
| 105 | * Holds information about breakpoints in a kernel. These breakpoints are |
| 106 | * added and removed by gdb. |
| 107 | */ |
| 108 | static struct kgdb_bkpt kgdb_break[KGDB_MAX_BREAKPOINTS] = { |
| 109 | [0 ... KGDB_MAX_BREAKPOINTS-1] = { .state = BP_UNDEFINED } |
| 110 | }; |
| 111 | |
| 112 | /* |
| 113 | * The CPU# of the active CPU, or -1 if none: |
| 114 | */ |
| 115 | atomic_t kgdb_active = ATOMIC_INIT(-1); |
| 116 | |
| 117 | /* |
| 118 | * We use NR_CPUs not PERCPU, in case kgdb is used to debug early |
| 119 | * bootup code (which might not have percpu set up yet): |
| 120 | */ |
| 121 | static atomic_t passive_cpu_wait[NR_CPUS]; |
| 122 | static atomic_t cpu_in_kgdb[NR_CPUS]; |
| 123 | atomic_t kgdb_setting_breakpoint; |
| 124 | |
| 125 | struct task_struct *kgdb_usethread; |
| 126 | struct task_struct *kgdb_contthread; |
| 127 | |
| 128 | int kgdb_single_step; |
| 129 | |
| 130 | /* Our I/O buffers. */ |
| 131 | static char remcom_in_buffer[BUFMAX]; |
| 132 | static char remcom_out_buffer[BUFMAX]; |
| 133 | |
| 134 | /* Storage for the registers, in GDB format. */ |
| 135 | static unsigned long gdb_regs[(NUMREGBYTES + |
| 136 | sizeof(unsigned long) - 1) / |
| 137 | sizeof(unsigned long)]; |
| 138 | |
| 139 | /* to keep track of the CPU which is doing the single stepping*/ |
| 140 | atomic_t kgdb_cpu_doing_single_step = ATOMIC_INIT(-1); |
| 141 | |
| 142 | /* |
| 143 | * If you are debugging a problem where roundup (the collection of |
| 144 | * all other CPUs) is a problem [this should be extremely rare], |
| 145 | * then use the nokgdbroundup option to avoid roundup. In that case |
| 146 | * the other CPUs might interfere with your debugging context, so |
| 147 | * use this with care: |
| 148 | */ |
| 149 | int kgdb_do_roundup = 1; |
| 150 | |
| 151 | static int __init opt_nokgdbroundup(char *str) |
| 152 | { |
| 153 | kgdb_do_roundup = 0; |
| 154 | |
| 155 | return 0; |
| 156 | } |
| 157 | |
| 158 | early_param("nokgdbroundup", opt_nokgdbroundup); |
| 159 | |
| 160 | /* |
| 161 | * Finally, some KGDB code :-) |
| 162 | */ |
| 163 | |
| 164 | /* |
| 165 | * Weak aliases for breakpoint management, |
| 166 | * can be overriden by architectures when needed: |
| 167 | */ |
| 168 | int __weak kgdb_validate_break_address(unsigned long addr) |
| 169 | { |
| 170 | char tmp_variable[BREAK_INSTR_SIZE]; |
| 171 | |
| 172 | return probe_kernel_read(tmp_variable, (char *)addr, BREAK_INSTR_SIZE); |
| 173 | } |
| 174 | |
| 175 | int __weak kgdb_arch_set_breakpoint(unsigned long addr, char *saved_instr) |
| 176 | { |
| 177 | int err; |
| 178 | |
| 179 | err = probe_kernel_read(saved_instr, (char *)addr, BREAK_INSTR_SIZE); |
| 180 | if (err) |
| 181 | return err; |
| 182 | |
| 183 | return probe_kernel_write((char *)addr, arch_kgdb_ops.gdb_bpt_instr, |
| 184 | BREAK_INSTR_SIZE); |
| 185 | } |
| 186 | |
| 187 | int __weak kgdb_arch_remove_breakpoint(unsigned long addr, char *bundle) |
| 188 | { |
| 189 | return probe_kernel_write((char *)addr, |
| 190 | (char *)bundle, BREAK_INSTR_SIZE); |
| 191 | } |
| 192 | |
| 193 | unsigned long __weak kgdb_arch_pc(int exception, struct pt_regs *regs) |
| 194 | { |
| 195 | return instruction_pointer(regs); |
| 196 | } |
| 197 | |
| 198 | int __weak kgdb_arch_init(void) |
| 199 | { |
| 200 | return 0; |
| 201 | } |
| 202 | |
Jason Wessel | b4b8ac5 | 2008-02-20 13:33:38 -0600 | [diff] [blame] | 203 | int __weak kgdb_skipexception(int exception, struct pt_regs *regs) |
| 204 | { |
| 205 | return 0; |
| 206 | } |
| 207 | |
| 208 | void __weak |
| 209 | kgdb_post_primary_code(struct pt_regs *regs, int e_vector, int err_code) |
| 210 | { |
| 211 | return; |
| 212 | } |
| 213 | |
Jason Wessel | dc7d552 | 2008-04-17 20:05:37 +0200 | [diff] [blame] | 214 | /** |
| 215 | * kgdb_disable_hw_debug - Disable hardware debugging while we in kgdb. |
| 216 | * @regs: Current &struct pt_regs. |
| 217 | * |
| 218 | * This function will be called if the particular architecture must |
| 219 | * disable hardware debugging while it is processing gdb packets or |
| 220 | * handling exception. |
| 221 | */ |
| 222 | void __weak kgdb_disable_hw_debug(struct pt_regs *regs) |
| 223 | { |
| 224 | } |
| 225 | |
| 226 | /* |
| 227 | * GDB remote protocol parser: |
| 228 | */ |
| 229 | |
| 230 | static const char hexchars[] = "0123456789abcdef"; |
| 231 | |
| 232 | static int hex(char ch) |
| 233 | { |
| 234 | if ((ch >= 'a') && (ch <= 'f')) |
| 235 | return ch - 'a' + 10; |
| 236 | if ((ch >= '0') && (ch <= '9')) |
| 237 | return ch - '0'; |
| 238 | if ((ch >= 'A') && (ch <= 'F')) |
| 239 | return ch - 'A' + 10; |
| 240 | return -1; |
| 241 | } |
| 242 | |
| 243 | /* scan for the sequence $<data>#<checksum> */ |
| 244 | static void get_packet(char *buffer) |
| 245 | { |
| 246 | unsigned char checksum; |
| 247 | unsigned char xmitcsum; |
| 248 | int count; |
| 249 | char ch; |
| 250 | |
| 251 | do { |
| 252 | /* |
| 253 | * Spin and wait around for the start character, ignore all |
| 254 | * other characters: |
| 255 | */ |
| 256 | while ((ch = (kgdb_io_ops->read_char())) != '$') |
| 257 | /* nothing */; |
| 258 | |
| 259 | kgdb_connected = 1; |
| 260 | checksum = 0; |
| 261 | xmitcsum = -1; |
| 262 | |
| 263 | count = 0; |
| 264 | |
| 265 | /* |
| 266 | * now, read until a # or end of buffer is found: |
| 267 | */ |
| 268 | while (count < (BUFMAX - 1)) { |
| 269 | ch = kgdb_io_ops->read_char(); |
| 270 | if (ch == '#') |
| 271 | break; |
| 272 | checksum = checksum + ch; |
| 273 | buffer[count] = ch; |
| 274 | count = count + 1; |
| 275 | } |
| 276 | buffer[count] = 0; |
| 277 | |
| 278 | if (ch == '#') { |
| 279 | xmitcsum = hex(kgdb_io_ops->read_char()) << 4; |
| 280 | xmitcsum += hex(kgdb_io_ops->read_char()); |
| 281 | |
| 282 | if (checksum != xmitcsum) |
| 283 | /* failed checksum */ |
| 284 | kgdb_io_ops->write_char('-'); |
| 285 | else |
| 286 | /* successful transfer */ |
| 287 | kgdb_io_ops->write_char('+'); |
| 288 | if (kgdb_io_ops->flush) |
| 289 | kgdb_io_ops->flush(); |
| 290 | } |
| 291 | } while (checksum != xmitcsum); |
| 292 | } |
| 293 | |
| 294 | /* |
| 295 | * Send the packet in buffer. |
| 296 | * Check for gdb connection if asked for. |
| 297 | */ |
| 298 | static void put_packet(char *buffer) |
| 299 | { |
| 300 | unsigned char checksum; |
| 301 | int count; |
| 302 | char ch; |
| 303 | |
| 304 | /* |
| 305 | * $<packet info>#<checksum>. |
| 306 | */ |
| 307 | while (1) { |
| 308 | kgdb_io_ops->write_char('$'); |
| 309 | checksum = 0; |
| 310 | count = 0; |
| 311 | |
| 312 | while ((ch = buffer[count])) { |
| 313 | kgdb_io_ops->write_char(ch); |
| 314 | checksum += ch; |
| 315 | count++; |
| 316 | } |
| 317 | |
| 318 | kgdb_io_ops->write_char('#'); |
| 319 | kgdb_io_ops->write_char(hexchars[checksum >> 4]); |
| 320 | kgdb_io_ops->write_char(hexchars[checksum & 0xf]); |
| 321 | if (kgdb_io_ops->flush) |
| 322 | kgdb_io_ops->flush(); |
| 323 | |
| 324 | /* Now see what we get in reply. */ |
| 325 | ch = kgdb_io_ops->read_char(); |
| 326 | |
| 327 | if (ch == 3) |
| 328 | ch = kgdb_io_ops->read_char(); |
| 329 | |
| 330 | /* If we get an ACK, we are done. */ |
| 331 | if (ch == '+') |
| 332 | return; |
| 333 | |
| 334 | /* |
| 335 | * If we get the start of another packet, this means |
| 336 | * that GDB is attempting to reconnect. We will NAK |
| 337 | * the packet being sent, and stop trying to send this |
| 338 | * packet. |
| 339 | */ |
| 340 | if (ch == '$') { |
| 341 | kgdb_io_ops->write_char('-'); |
| 342 | if (kgdb_io_ops->flush) |
| 343 | kgdb_io_ops->flush(); |
| 344 | return; |
| 345 | } |
| 346 | } |
| 347 | } |
| 348 | |
| 349 | static char *pack_hex_byte(char *pkt, u8 byte) |
| 350 | { |
| 351 | *pkt++ = hexchars[byte >> 4]; |
| 352 | *pkt++ = hexchars[byte & 0xf]; |
| 353 | |
| 354 | return pkt; |
| 355 | } |
| 356 | |
| 357 | /* |
| 358 | * Convert the memory pointed to by mem into hex, placing result in buf. |
| 359 | * Return a pointer to the last char put in buf (null). May return an error. |
| 360 | */ |
| 361 | int kgdb_mem2hex(char *mem, char *buf, int count) |
| 362 | { |
| 363 | char *tmp; |
| 364 | int err; |
| 365 | |
| 366 | /* |
| 367 | * We use the upper half of buf as an intermediate buffer for the |
| 368 | * raw memory copy. Hex conversion will work against this one. |
| 369 | */ |
| 370 | tmp = buf + count; |
| 371 | |
| 372 | err = probe_kernel_read(tmp, mem, count); |
| 373 | if (!err) { |
| 374 | while (count > 0) { |
| 375 | buf = pack_hex_byte(buf, *tmp); |
| 376 | tmp++; |
| 377 | count--; |
| 378 | } |
| 379 | |
| 380 | *buf = 0; |
| 381 | } |
| 382 | |
| 383 | return err; |
| 384 | } |
| 385 | |
| 386 | /* |
| 387 | * Copy the binary array pointed to by buf into mem. Fix $, #, and |
| 388 | * 0x7d escaped with 0x7d. Return a pointer to the character after |
| 389 | * the last byte written. |
| 390 | */ |
| 391 | static int kgdb_ebin2mem(char *buf, char *mem, int count) |
| 392 | { |
| 393 | int err = 0; |
| 394 | char c; |
| 395 | |
| 396 | while (count-- > 0) { |
| 397 | c = *buf++; |
| 398 | if (c == 0x7d) |
| 399 | c = *buf++ ^ 0x20; |
| 400 | |
| 401 | err = probe_kernel_write(mem, &c, 1); |
| 402 | if (err) |
| 403 | break; |
| 404 | |
| 405 | mem++; |
| 406 | } |
| 407 | |
| 408 | return err; |
| 409 | } |
| 410 | |
| 411 | /* |
| 412 | * Convert the hex array pointed to by buf into binary to be placed in mem. |
| 413 | * Return a pointer to the character AFTER the last byte written. |
| 414 | * May return an error. |
| 415 | */ |
| 416 | int kgdb_hex2mem(char *buf, char *mem, int count) |
| 417 | { |
| 418 | char *tmp_raw; |
| 419 | char *tmp_hex; |
| 420 | |
| 421 | /* |
| 422 | * We use the upper half of buf as an intermediate buffer for the |
| 423 | * raw memory that is converted from hex. |
| 424 | */ |
| 425 | tmp_raw = buf + count * 2; |
| 426 | |
| 427 | tmp_hex = tmp_raw - 1; |
| 428 | while (tmp_hex >= buf) { |
| 429 | tmp_raw--; |
| 430 | *tmp_raw = hex(*tmp_hex--); |
| 431 | *tmp_raw |= hex(*tmp_hex--) << 4; |
| 432 | } |
| 433 | |
| 434 | return probe_kernel_write(mem, tmp_raw, count); |
| 435 | } |
| 436 | |
| 437 | /* |
| 438 | * While we find nice hex chars, build a long_val. |
| 439 | * Return number of chars processed. |
| 440 | */ |
| 441 | int kgdb_hex2long(char **ptr, long *long_val) |
| 442 | { |
| 443 | int hex_val; |
| 444 | int num = 0; |
| 445 | |
| 446 | *long_val = 0; |
| 447 | |
| 448 | while (**ptr) { |
| 449 | hex_val = hex(**ptr); |
| 450 | if (hex_val < 0) |
| 451 | break; |
| 452 | |
| 453 | *long_val = (*long_val << 4) | hex_val; |
| 454 | num++; |
| 455 | (*ptr)++; |
| 456 | } |
| 457 | |
| 458 | return num; |
| 459 | } |
| 460 | |
| 461 | /* Write memory due to an 'M' or 'X' packet. */ |
| 462 | static int write_mem_msg(int binary) |
| 463 | { |
| 464 | char *ptr = &remcom_in_buffer[1]; |
| 465 | unsigned long addr; |
| 466 | unsigned long length; |
| 467 | int err; |
| 468 | |
| 469 | if (kgdb_hex2long(&ptr, &addr) > 0 && *(ptr++) == ',' && |
| 470 | kgdb_hex2long(&ptr, &length) > 0 && *(ptr++) == ':') { |
| 471 | if (binary) |
| 472 | err = kgdb_ebin2mem(ptr, (char *)addr, length); |
| 473 | else |
| 474 | err = kgdb_hex2mem(ptr, (char *)addr, length); |
| 475 | if (err) |
| 476 | return err; |
| 477 | if (CACHE_FLUSH_IS_SAFE) |
| 478 | flush_icache_range(addr, addr + length + 1); |
| 479 | return 0; |
| 480 | } |
| 481 | |
| 482 | return -EINVAL; |
| 483 | } |
| 484 | |
| 485 | static void error_packet(char *pkt, int error) |
| 486 | { |
| 487 | error = -error; |
| 488 | pkt[0] = 'E'; |
| 489 | pkt[1] = hexchars[(error / 10)]; |
| 490 | pkt[2] = hexchars[(error % 10)]; |
| 491 | pkt[3] = '\0'; |
| 492 | } |
| 493 | |
| 494 | /* |
| 495 | * Thread ID accessors. We represent a flat TID space to GDB, where |
| 496 | * the per CPU idle threads (which under Linux all have PID 0) are |
| 497 | * remapped to negative TIDs. |
| 498 | */ |
| 499 | |
| 500 | #define BUF_THREAD_ID_SIZE 16 |
| 501 | |
| 502 | static char *pack_threadid(char *pkt, unsigned char *id) |
| 503 | { |
| 504 | char *limit; |
| 505 | |
| 506 | limit = pkt + BUF_THREAD_ID_SIZE; |
| 507 | while (pkt < limit) |
| 508 | pkt = pack_hex_byte(pkt, *id++); |
| 509 | |
| 510 | return pkt; |
| 511 | } |
| 512 | |
| 513 | static void int_to_threadref(unsigned char *id, int value) |
| 514 | { |
| 515 | unsigned char *scan; |
| 516 | int i = 4; |
| 517 | |
| 518 | scan = (unsigned char *)id; |
| 519 | while (i--) |
| 520 | *scan++ = 0; |
| 521 | *scan++ = (value >> 24) & 0xff; |
| 522 | *scan++ = (value >> 16) & 0xff; |
| 523 | *scan++ = (value >> 8) & 0xff; |
| 524 | *scan++ = (value & 0xff); |
| 525 | } |
| 526 | |
| 527 | static struct task_struct *getthread(struct pt_regs *regs, int tid) |
| 528 | { |
| 529 | /* |
| 530 | * Non-positive TIDs are remapped idle tasks: |
| 531 | */ |
| 532 | if (tid <= 0) |
| 533 | return idle_task(-tid); |
| 534 | |
| 535 | /* |
| 536 | * find_task_by_pid_ns() does not take the tasklist lock anymore |
| 537 | * but is nicely RCU locked - hence is a pretty resilient |
| 538 | * thing to use: |
| 539 | */ |
| 540 | return find_task_by_pid_ns(tid, &init_pid_ns); |
| 541 | } |
| 542 | |
| 543 | /* |
| 544 | * CPU debug state control: |
| 545 | */ |
| 546 | |
| 547 | #ifdef CONFIG_SMP |
| 548 | static void kgdb_wait(struct pt_regs *regs) |
| 549 | { |
| 550 | unsigned long flags; |
| 551 | int cpu; |
| 552 | |
| 553 | local_irq_save(flags); |
| 554 | cpu = raw_smp_processor_id(); |
| 555 | kgdb_info[cpu].debuggerinfo = regs; |
| 556 | kgdb_info[cpu].task = current; |
| 557 | /* |
| 558 | * Make sure the above info reaches the primary CPU before |
| 559 | * our cpu_in_kgdb[] flag setting does: |
| 560 | */ |
| 561 | smp_wmb(); |
| 562 | atomic_set(&cpu_in_kgdb[cpu], 1); |
| 563 | |
Jason Wessel | dc7d552 | 2008-04-17 20:05:37 +0200 | [diff] [blame] | 564 | /* Wait till primary CPU is done with debugging */ |
| 565 | while (atomic_read(&passive_cpu_wait[cpu])) |
| 566 | cpu_relax(); |
| 567 | |
| 568 | kgdb_info[cpu].debuggerinfo = NULL; |
| 569 | kgdb_info[cpu].task = NULL; |
| 570 | |
| 571 | /* fix up hardware debug registers on local cpu */ |
| 572 | if (arch_kgdb_ops.correct_hw_break) |
| 573 | arch_kgdb_ops.correct_hw_break(); |
| 574 | |
| 575 | /* Signal the primary CPU that we are done: */ |
| 576 | atomic_set(&cpu_in_kgdb[cpu], 0); |
Jason Wessel | 7c3078b | 2008-02-15 14:55:54 -0600 | [diff] [blame] | 577 | clocksource_touch_watchdog(); |
Jason Wessel | dc7d552 | 2008-04-17 20:05:37 +0200 | [diff] [blame] | 578 | local_irq_restore(flags); |
| 579 | } |
| 580 | #endif |
| 581 | |
| 582 | /* |
| 583 | * Some architectures need cache flushes when we set/clear a |
| 584 | * breakpoint: |
| 585 | */ |
| 586 | static void kgdb_flush_swbreak_addr(unsigned long addr) |
| 587 | { |
| 588 | if (!CACHE_FLUSH_IS_SAFE) |
| 589 | return; |
| 590 | |
Jason Wessel | 737a460 | 2008-03-07 16:34:16 -0600 | [diff] [blame] | 591 | if (current->mm && current->mm->mmap_cache) { |
Jason Wessel | dc7d552 | 2008-04-17 20:05:37 +0200 | [diff] [blame] | 592 | flush_cache_range(current->mm->mmap_cache, |
| 593 | addr, addr + BREAK_INSTR_SIZE); |
Jason Wessel | dc7d552 | 2008-04-17 20:05:37 +0200 | [diff] [blame] | 594 | } |
Jason Wessel | 1a9a3e7 | 2008-04-01 16:55:28 -0500 | [diff] [blame] | 595 | /* Force flush instruction cache if it was outside the mm */ |
| 596 | flush_icache_range(addr, addr + BREAK_INSTR_SIZE); |
Jason Wessel | dc7d552 | 2008-04-17 20:05:37 +0200 | [diff] [blame] | 597 | } |
| 598 | |
| 599 | /* |
| 600 | * SW breakpoint management: |
| 601 | */ |
| 602 | static int kgdb_activate_sw_breakpoints(void) |
| 603 | { |
| 604 | unsigned long addr; |
| 605 | int error = 0; |
| 606 | int i; |
| 607 | |
| 608 | for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { |
| 609 | if (kgdb_break[i].state != BP_SET) |
| 610 | continue; |
| 611 | |
| 612 | addr = kgdb_break[i].bpt_addr; |
| 613 | error = kgdb_arch_set_breakpoint(addr, |
| 614 | kgdb_break[i].saved_instr); |
| 615 | if (error) |
| 616 | return error; |
| 617 | |
| 618 | kgdb_flush_swbreak_addr(addr); |
| 619 | kgdb_break[i].state = BP_ACTIVE; |
| 620 | } |
| 621 | return 0; |
| 622 | } |
| 623 | |
| 624 | static int kgdb_set_sw_break(unsigned long addr) |
| 625 | { |
| 626 | int err = kgdb_validate_break_address(addr); |
| 627 | int breakno = -1; |
| 628 | int i; |
| 629 | |
| 630 | if (err) |
| 631 | return err; |
| 632 | |
| 633 | for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { |
| 634 | if ((kgdb_break[i].state == BP_SET) && |
| 635 | (kgdb_break[i].bpt_addr == addr)) |
| 636 | return -EEXIST; |
| 637 | } |
| 638 | for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { |
| 639 | if (kgdb_break[i].state == BP_REMOVED && |
| 640 | kgdb_break[i].bpt_addr == addr) { |
| 641 | breakno = i; |
| 642 | break; |
| 643 | } |
| 644 | } |
| 645 | |
| 646 | if (breakno == -1) { |
| 647 | for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { |
| 648 | if (kgdb_break[i].state == BP_UNDEFINED) { |
| 649 | breakno = i; |
| 650 | break; |
| 651 | } |
| 652 | } |
| 653 | } |
| 654 | |
| 655 | if (breakno == -1) |
| 656 | return -E2BIG; |
| 657 | |
| 658 | kgdb_break[breakno].state = BP_SET; |
| 659 | kgdb_break[breakno].type = BP_BREAKPOINT; |
| 660 | kgdb_break[breakno].bpt_addr = addr; |
| 661 | |
| 662 | return 0; |
| 663 | } |
| 664 | |
| 665 | static int kgdb_deactivate_sw_breakpoints(void) |
| 666 | { |
| 667 | unsigned long addr; |
| 668 | int error = 0; |
| 669 | int i; |
| 670 | |
| 671 | for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { |
| 672 | if (kgdb_break[i].state != BP_ACTIVE) |
| 673 | continue; |
| 674 | addr = kgdb_break[i].bpt_addr; |
| 675 | error = kgdb_arch_remove_breakpoint(addr, |
| 676 | kgdb_break[i].saved_instr); |
| 677 | if (error) |
| 678 | return error; |
| 679 | |
| 680 | kgdb_flush_swbreak_addr(addr); |
| 681 | kgdb_break[i].state = BP_SET; |
| 682 | } |
| 683 | return 0; |
| 684 | } |
| 685 | |
| 686 | static int kgdb_remove_sw_break(unsigned long addr) |
| 687 | { |
| 688 | int i; |
| 689 | |
| 690 | for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { |
| 691 | if ((kgdb_break[i].state == BP_SET) && |
| 692 | (kgdb_break[i].bpt_addr == addr)) { |
| 693 | kgdb_break[i].state = BP_REMOVED; |
| 694 | return 0; |
| 695 | } |
| 696 | } |
| 697 | return -ENOENT; |
| 698 | } |
| 699 | |
| 700 | int kgdb_isremovedbreak(unsigned long addr) |
| 701 | { |
| 702 | int i; |
| 703 | |
| 704 | for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { |
| 705 | if ((kgdb_break[i].state == BP_REMOVED) && |
| 706 | (kgdb_break[i].bpt_addr == addr)) |
| 707 | return 1; |
| 708 | } |
| 709 | return 0; |
| 710 | } |
| 711 | |
| 712 | int remove_all_break(void) |
| 713 | { |
| 714 | unsigned long addr; |
| 715 | int error; |
| 716 | int i; |
| 717 | |
| 718 | /* Clear memory breakpoints. */ |
| 719 | for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { |
Jason Wessel | 737a460 | 2008-03-07 16:34:16 -0600 | [diff] [blame] | 720 | if (kgdb_break[i].state != BP_ACTIVE) |
| 721 | goto setundefined; |
Jason Wessel | dc7d552 | 2008-04-17 20:05:37 +0200 | [diff] [blame] | 722 | addr = kgdb_break[i].bpt_addr; |
| 723 | error = kgdb_arch_remove_breakpoint(addr, |
| 724 | kgdb_break[i].saved_instr); |
| 725 | if (error) |
Jason Wessel | 737a460 | 2008-03-07 16:34:16 -0600 | [diff] [blame] | 726 | printk(KERN_ERR "KGDB: breakpoint remove failed: %lx\n", |
| 727 | addr); |
| 728 | setundefined: |
| 729 | kgdb_break[i].state = BP_UNDEFINED; |
Jason Wessel | dc7d552 | 2008-04-17 20:05:37 +0200 | [diff] [blame] | 730 | } |
| 731 | |
| 732 | /* Clear hardware breakpoints. */ |
| 733 | if (arch_kgdb_ops.remove_all_hw_break) |
| 734 | arch_kgdb_ops.remove_all_hw_break(); |
| 735 | |
| 736 | return 0; |
| 737 | } |
| 738 | |
| 739 | /* |
| 740 | * Remap normal tasks to their real PID, idle tasks to -1 ... -NR_CPUs: |
| 741 | */ |
| 742 | static inline int shadow_pid(int realpid) |
| 743 | { |
| 744 | if (realpid) |
| 745 | return realpid; |
| 746 | |
| 747 | return -1-raw_smp_processor_id(); |
| 748 | } |
| 749 | |
| 750 | static char gdbmsgbuf[BUFMAX + 1]; |
| 751 | |
| 752 | static void kgdb_msg_write(const char *s, int len) |
| 753 | { |
| 754 | char *bufptr; |
| 755 | int wcount; |
| 756 | int i; |
| 757 | |
| 758 | /* 'O'utput */ |
| 759 | gdbmsgbuf[0] = 'O'; |
| 760 | |
| 761 | /* Fill and send buffers... */ |
| 762 | while (len > 0) { |
| 763 | bufptr = gdbmsgbuf + 1; |
| 764 | |
| 765 | /* Calculate how many this time */ |
| 766 | if ((len << 1) > (BUFMAX - 2)) |
| 767 | wcount = (BUFMAX - 2) >> 1; |
| 768 | else |
| 769 | wcount = len; |
| 770 | |
| 771 | /* Pack in hex chars */ |
| 772 | for (i = 0; i < wcount; i++) |
| 773 | bufptr = pack_hex_byte(bufptr, s[i]); |
| 774 | *bufptr = '\0'; |
| 775 | |
| 776 | /* Move up */ |
| 777 | s += wcount; |
| 778 | len -= wcount; |
| 779 | |
| 780 | /* Write packet */ |
| 781 | put_packet(gdbmsgbuf); |
| 782 | } |
| 783 | } |
| 784 | |
| 785 | /* |
| 786 | * Return true if there is a valid kgdb I/O module. Also if no |
| 787 | * debugger is attached a message can be printed to the console about |
| 788 | * waiting for the debugger to attach. |
| 789 | * |
| 790 | * The print_wait argument is only to be true when called from inside |
| 791 | * the core kgdb_handle_exception, because it will wait for the |
| 792 | * debugger to attach. |
| 793 | */ |
| 794 | static int kgdb_io_ready(int print_wait) |
| 795 | { |
| 796 | if (!kgdb_io_ops) |
| 797 | return 0; |
| 798 | if (kgdb_connected) |
| 799 | return 1; |
| 800 | if (atomic_read(&kgdb_setting_breakpoint)) |
| 801 | return 1; |
| 802 | if (print_wait) |
| 803 | printk(KERN_CRIT "KGDB: Waiting for remote debugger\n"); |
| 804 | return 1; |
| 805 | } |
| 806 | |
| 807 | /* |
| 808 | * All the functions that start with gdb_cmd are the various |
| 809 | * operations to implement the handlers for the gdbserial protocol |
| 810 | * where KGDB is communicating with an external debugger |
| 811 | */ |
| 812 | |
| 813 | /* Handle the '?' status packets */ |
| 814 | static void gdb_cmd_status(struct kgdb_state *ks) |
| 815 | { |
| 816 | /* |
| 817 | * We know that this packet is only sent |
| 818 | * during initial connect. So to be safe, |
| 819 | * we clear out our breakpoints now in case |
| 820 | * GDB is reconnecting. |
| 821 | */ |
| 822 | remove_all_break(); |
| 823 | |
| 824 | remcom_out_buffer[0] = 'S'; |
| 825 | pack_hex_byte(&remcom_out_buffer[1], ks->signo); |
| 826 | } |
| 827 | |
| 828 | /* Handle the 'g' get registers request */ |
| 829 | static void gdb_cmd_getregs(struct kgdb_state *ks) |
| 830 | { |
| 831 | struct task_struct *thread; |
| 832 | void *local_debuggerinfo; |
| 833 | int i; |
| 834 | |
| 835 | thread = kgdb_usethread; |
| 836 | if (!thread) { |
| 837 | thread = kgdb_info[ks->cpu].task; |
| 838 | local_debuggerinfo = kgdb_info[ks->cpu].debuggerinfo; |
| 839 | } else { |
| 840 | local_debuggerinfo = NULL; |
| 841 | for (i = 0; i < NR_CPUS; i++) { |
| 842 | /* |
| 843 | * Try to find the task on some other |
| 844 | * or possibly this node if we do not |
| 845 | * find the matching task then we try |
| 846 | * to approximate the results. |
| 847 | */ |
| 848 | if (thread == kgdb_info[i].task) |
| 849 | local_debuggerinfo = kgdb_info[i].debuggerinfo; |
| 850 | } |
| 851 | } |
| 852 | |
| 853 | /* |
| 854 | * All threads that don't have debuggerinfo should be |
| 855 | * in __schedule() sleeping, since all other CPUs |
| 856 | * are in kgdb_wait, and thus have debuggerinfo. |
| 857 | */ |
| 858 | if (local_debuggerinfo) { |
| 859 | pt_regs_to_gdb_regs(gdb_regs, local_debuggerinfo); |
| 860 | } else { |
| 861 | /* |
| 862 | * Pull stuff saved during switch_to; nothing |
| 863 | * else is accessible (or even particularly |
| 864 | * relevant). |
| 865 | * |
| 866 | * This should be enough for a stack trace. |
| 867 | */ |
| 868 | sleeping_thread_to_gdb_regs(gdb_regs, thread); |
| 869 | } |
| 870 | kgdb_mem2hex((char *)gdb_regs, remcom_out_buffer, NUMREGBYTES); |
| 871 | } |
| 872 | |
| 873 | /* Handle the 'G' set registers request */ |
| 874 | static void gdb_cmd_setregs(struct kgdb_state *ks) |
| 875 | { |
| 876 | kgdb_hex2mem(&remcom_in_buffer[1], (char *)gdb_regs, NUMREGBYTES); |
| 877 | |
| 878 | if (kgdb_usethread && kgdb_usethread != current) { |
| 879 | error_packet(remcom_out_buffer, -EINVAL); |
| 880 | } else { |
| 881 | gdb_regs_to_pt_regs(gdb_regs, ks->linux_regs); |
| 882 | strcpy(remcom_out_buffer, "OK"); |
| 883 | } |
| 884 | } |
| 885 | |
| 886 | /* Handle the 'm' memory read bytes */ |
| 887 | static void gdb_cmd_memread(struct kgdb_state *ks) |
| 888 | { |
| 889 | char *ptr = &remcom_in_buffer[1]; |
| 890 | unsigned long length; |
| 891 | unsigned long addr; |
| 892 | int err; |
| 893 | |
| 894 | if (kgdb_hex2long(&ptr, &addr) > 0 && *ptr++ == ',' && |
| 895 | kgdb_hex2long(&ptr, &length) > 0) { |
| 896 | err = kgdb_mem2hex((char *)addr, remcom_out_buffer, length); |
| 897 | if (err) |
| 898 | error_packet(remcom_out_buffer, err); |
| 899 | } else { |
| 900 | error_packet(remcom_out_buffer, -EINVAL); |
| 901 | } |
| 902 | } |
| 903 | |
| 904 | /* Handle the 'M' memory write bytes */ |
| 905 | static void gdb_cmd_memwrite(struct kgdb_state *ks) |
| 906 | { |
| 907 | int err = write_mem_msg(0); |
| 908 | |
| 909 | if (err) |
| 910 | error_packet(remcom_out_buffer, err); |
| 911 | else |
| 912 | strcpy(remcom_out_buffer, "OK"); |
| 913 | } |
| 914 | |
| 915 | /* Handle the 'X' memory binary write bytes */ |
| 916 | static void gdb_cmd_binwrite(struct kgdb_state *ks) |
| 917 | { |
| 918 | int err = write_mem_msg(1); |
| 919 | |
| 920 | if (err) |
| 921 | error_packet(remcom_out_buffer, err); |
| 922 | else |
| 923 | strcpy(remcom_out_buffer, "OK"); |
| 924 | } |
| 925 | |
| 926 | /* Handle the 'D' or 'k', detach or kill packets */ |
| 927 | static void gdb_cmd_detachkill(struct kgdb_state *ks) |
| 928 | { |
| 929 | int error; |
| 930 | |
| 931 | /* The detach case */ |
| 932 | if (remcom_in_buffer[0] == 'D') { |
| 933 | error = remove_all_break(); |
| 934 | if (error < 0) { |
| 935 | error_packet(remcom_out_buffer, error); |
| 936 | } else { |
| 937 | strcpy(remcom_out_buffer, "OK"); |
| 938 | kgdb_connected = 0; |
| 939 | } |
| 940 | put_packet(remcom_out_buffer); |
| 941 | } else { |
| 942 | /* |
| 943 | * Assume the kill case, with no exit code checking, |
| 944 | * trying to force detach the debugger: |
| 945 | */ |
| 946 | remove_all_break(); |
| 947 | kgdb_connected = 0; |
| 948 | } |
| 949 | } |
| 950 | |
| 951 | /* Handle the 'R' reboot packets */ |
| 952 | static int gdb_cmd_reboot(struct kgdb_state *ks) |
| 953 | { |
| 954 | /* For now, only honor R0 */ |
| 955 | if (strcmp(remcom_in_buffer, "R0") == 0) { |
| 956 | printk(KERN_CRIT "Executing emergency reboot\n"); |
| 957 | strcpy(remcom_out_buffer, "OK"); |
| 958 | put_packet(remcom_out_buffer); |
| 959 | |
| 960 | /* |
| 961 | * Execution should not return from |
| 962 | * machine_emergency_restart() |
| 963 | */ |
| 964 | machine_emergency_restart(); |
| 965 | kgdb_connected = 0; |
| 966 | |
| 967 | return 1; |
| 968 | } |
| 969 | return 0; |
| 970 | } |
| 971 | |
| 972 | /* Handle the 'q' query packets */ |
| 973 | static void gdb_cmd_query(struct kgdb_state *ks) |
| 974 | { |
| 975 | struct task_struct *thread; |
| 976 | unsigned char thref[8]; |
| 977 | char *ptr; |
| 978 | int i; |
| 979 | |
| 980 | switch (remcom_in_buffer[1]) { |
| 981 | case 's': |
| 982 | case 'f': |
| 983 | if (memcmp(remcom_in_buffer + 2, "ThreadInfo", 10)) { |
| 984 | error_packet(remcom_out_buffer, -EINVAL); |
| 985 | break; |
| 986 | } |
| 987 | |
| 988 | if (remcom_in_buffer[1] == 'f') |
| 989 | ks->threadid = 1; |
| 990 | |
| 991 | remcom_out_buffer[0] = 'm'; |
| 992 | ptr = remcom_out_buffer + 1; |
| 993 | |
| 994 | for (i = 0; i < 17; ks->threadid++) { |
| 995 | thread = getthread(ks->linux_regs, ks->threadid); |
| 996 | if (thread) { |
| 997 | int_to_threadref(thref, ks->threadid); |
| 998 | pack_threadid(ptr, thref); |
| 999 | ptr += BUF_THREAD_ID_SIZE; |
| 1000 | *(ptr++) = ','; |
| 1001 | i++; |
| 1002 | } |
| 1003 | } |
| 1004 | *(--ptr) = '\0'; |
| 1005 | break; |
| 1006 | |
| 1007 | case 'C': |
| 1008 | /* Current thread id */ |
| 1009 | strcpy(remcom_out_buffer, "QC"); |
| 1010 | ks->threadid = shadow_pid(current->pid); |
| 1011 | int_to_threadref(thref, ks->threadid); |
| 1012 | pack_threadid(remcom_out_buffer + 2, thref); |
| 1013 | break; |
| 1014 | case 'T': |
| 1015 | if (memcmp(remcom_in_buffer + 1, "ThreadExtraInfo,", 16)) { |
| 1016 | error_packet(remcom_out_buffer, -EINVAL); |
| 1017 | break; |
| 1018 | } |
| 1019 | ks->threadid = 0; |
| 1020 | ptr = remcom_in_buffer + 17; |
| 1021 | kgdb_hex2long(&ptr, &ks->threadid); |
| 1022 | if (!getthread(ks->linux_regs, ks->threadid)) { |
| 1023 | error_packet(remcom_out_buffer, -EINVAL); |
| 1024 | break; |
| 1025 | } |
| 1026 | if (ks->threadid > 0) { |
| 1027 | kgdb_mem2hex(getthread(ks->linux_regs, |
| 1028 | ks->threadid)->comm, |
| 1029 | remcom_out_buffer, 16); |
| 1030 | } else { |
| 1031 | static char tmpstr[23 + BUF_THREAD_ID_SIZE]; |
| 1032 | |
| 1033 | sprintf(tmpstr, "Shadow task %d for pid 0", |
| 1034 | (int)(-ks->threadid-1)); |
| 1035 | kgdb_mem2hex(tmpstr, remcom_out_buffer, strlen(tmpstr)); |
| 1036 | } |
| 1037 | break; |
| 1038 | } |
| 1039 | } |
| 1040 | |
| 1041 | /* Handle the 'H' task query packets */ |
| 1042 | static void gdb_cmd_task(struct kgdb_state *ks) |
| 1043 | { |
| 1044 | struct task_struct *thread; |
| 1045 | char *ptr; |
| 1046 | |
| 1047 | switch (remcom_in_buffer[1]) { |
| 1048 | case 'g': |
| 1049 | ptr = &remcom_in_buffer[2]; |
| 1050 | kgdb_hex2long(&ptr, &ks->threadid); |
| 1051 | thread = getthread(ks->linux_regs, ks->threadid); |
| 1052 | if (!thread && ks->threadid > 0) { |
| 1053 | error_packet(remcom_out_buffer, -EINVAL); |
| 1054 | break; |
| 1055 | } |
| 1056 | kgdb_usethread = thread; |
| 1057 | ks->kgdb_usethreadid = ks->threadid; |
| 1058 | strcpy(remcom_out_buffer, "OK"); |
| 1059 | break; |
| 1060 | case 'c': |
| 1061 | ptr = &remcom_in_buffer[2]; |
| 1062 | kgdb_hex2long(&ptr, &ks->threadid); |
| 1063 | if (!ks->threadid) { |
| 1064 | kgdb_contthread = NULL; |
| 1065 | } else { |
| 1066 | thread = getthread(ks->linux_regs, ks->threadid); |
| 1067 | if (!thread && ks->threadid > 0) { |
| 1068 | error_packet(remcom_out_buffer, -EINVAL); |
| 1069 | break; |
| 1070 | } |
| 1071 | kgdb_contthread = thread; |
| 1072 | } |
| 1073 | strcpy(remcom_out_buffer, "OK"); |
| 1074 | break; |
| 1075 | } |
| 1076 | } |
| 1077 | |
| 1078 | /* Handle the 'T' thread query packets */ |
| 1079 | static void gdb_cmd_thread(struct kgdb_state *ks) |
| 1080 | { |
| 1081 | char *ptr = &remcom_in_buffer[1]; |
| 1082 | struct task_struct *thread; |
| 1083 | |
| 1084 | kgdb_hex2long(&ptr, &ks->threadid); |
| 1085 | thread = getthread(ks->linux_regs, ks->threadid); |
| 1086 | if (thread) |
| 1087 | strcpy(remcom_out_buffer, "OK"); |
| 1088 | else |
| 1089 | error_packet(remcom_out_buffer, -EINVAL); |
| 1090 | } |
| 1091 | |
| 1092 | /* Handle the 'z' or 'Z' breakpoint remove or set packets */ |
| 1093 | static void gdb_cmd_break(struct kgdb_state *ks) |
| 1094 | { |
| 1095 | /* |
| 1096 | * Since GDB-5.3, it's been drafted that '0' is a software |
| 1097 | * breakpoint, '1' is a hardware breakpoint, so let's do that. |
| 1098 | */ |
| 1099 | char *bpt_type = &remcom_in_buffer[1]; |
| 1100 | char *ptr = &remcom_in_buffer[2]; |
| 1101 | unsigned long addr; |
| 1102 | unsigned long length; |
| 1103 | int error = 0; |
| 1104 | |
| 1105 | if (arch_kgdb_ops.set_hw_breakpoint && *bpt_type >= '1') { |
| 1106 | /* Unsupported */ |
| 1107 | if (*bpt_type > '4') |
| 1108 | return; |
| 1109 | } else { |
| 1110 | if (*bpt_type != '0' && *bpt_type != '1') |
| 1111 | /* Unsupported. */ |
| 1112 | return; |
| 1113 | } |
| 1114 | |
| 1115 | /* |
| 1116 | * Test if this is a hardware breakpoint, and |
| 1117 | * if we support it: |
| 1118 | */ |
| 1119 | if (*bpt_type == '1' && !(arch_kgdb_ops.flags & KGDB_HW_BREAKPOINT)) |
| 1120 | /* Unsupported. */ |
| 1121 | return; |
| 1122 | |
| 1123 | if (*(ptr++) != ',') { |
| 1124 | error_packet(remcom_out_buffer, -EINVAL); |
| 1125 | return; |
| 1126 | } |
| 1127 | if (!kgdb_hex2long(&ptr, &addr)) { |
| 1128 | error_packet(remcom_out_buffer, -EINVAL); |
| 1129 | return; |
| 1130 | } |
| 1131 | if (*(ptr++) != ',' || |
| 1132 | !kgdb_hex2long(&ptr, &length)) { |
| 1133 | error_packet(remcom_out_buffer, -EINVAL); |
| 1134 | return; |
| 1135 | } |
| 1136 | |
| 1137 | if (remcom_in_buffer[0] == 'Z' && *bpt_type == '0') |
| 1138 | error = kgdb_set_sw_break(addr); |
| 1139 | else if (remcom_in_buffer[0] == 'z' && *bpt_type == '0') |
| 1140 | error = kgdb_remove_sw_break(addr); |
| 1141 | else if (remcom_in_buffer[0] == 'Z') |
| 1142 | error = arch_kgdb_ops.set_hw_breakpoint(addr, |
Jason Wessel | 64e9ee3 | 2008-02-15 14:55:56 -0600 | [diff] [blame] | 1143 | (int)length, *bpt_type - '0'); |
Jason Wessel | dc7d552 | 2008-04-17 20:05:37 +0200 | [diff] [blame] | 1144 | else if (remcom_in_buffer[0] == 'z') |
| 1145 | error = arch_kgdb_ops.remove_hw_breakpoint(addr, |
Jason Wessel | 64e9ee3 | 2008-02-15 14:55:56 -0600 | [diff] [blame] | 1146 | (int) length, *bpt_type - '0'); |
Jason Wessel | dc7d552 | 2008-04-17 20:05:37 +0200 | [diff] [blame] | 1147 | |
| 1148 | if (error == 0) |
| 1149 | strcpy(remcom_out_buffer, "OK"); |
| 1150 | else |
| 1151 | error_packet(remcom_out_buffer, error); |
| 1152 | } |
| 1153 | |
| 1154 | /* Handle the 'C' signal / exception passing packets */ |
| 1155 | static int gdb_cmd_exception_pass(struct kgdb_state *ks) |
| 1156 | { |
| 1157 | /* C09 == pass exception |
| 1158 | * C15 == detach kgdb, pass exception |
| 1159 | */ |
| 1160 | if (remcom_in_buffer[1] == '0' && remcom_in_buffer[2] == '9') { |
| 1161 | |
| 1162 | ks->pass_exception = 1; |
| 1163 | remcom_in_buffer[0] = 'c'; |
| 1164 | |
| 1165 | } else if (remcom_in_buffer[1] == '1' && remcom_in_buffer[2] == '5') { |
| 1166 | |
| 1167 | ks->pass_exception = 1; |
| 1168 | remcom_in_buffer[0] = 'D'; |
| 1169 | remove_all_break(); |
| 1170 | kgdb_connected = 0; |
| 1171 | return 1; |
| 1172 | |
| 1173 | } else { |
| 1174 | error_packet(remcom_out_buffer, -EINVAL); |
| 1175 | return 0; |
| 1176 | } |
| 1177 | |
| 1178 | /* Indicate fall through */ |
| 1179 | return -1; |
| 1180 | } |
| 1181 | |
| 1182 | /* |
| 1183 | * This function performs all gdbserial command procesing |
| 1184 | */ |
| 1185 | static int gdb_serial_stub(struct kgdb_state *ks) |
| 1186 | { |
| 1187 | int error = 0; |
| 1188 | int tmp; |
| 1189 | |
| 1190 | /* Clear the out buffer. */ |
| 1191 | memset(remcom_out_buffer, 0, sizeof(remcom_out_buffer)); |
| 1192 | |
| 1193 | if (kgdb_connected) { |
| 1194 | unsigned char thref[8]; |
| 1195 | char *ptr; |
| 1196 | |
| 1197 | /* Reply to host that an exception has occurred */ |
| 1198 | ptr = remcom_out_buffer; |
| 1199 | *ptr++ = 'T'; |
| 1200 | ptr = pack_hex_byte(ptr, ks->signo); |
| 1201 | ptr += strlen(strcpy(ptr, "thread:")); |
| 1202 | int_to_threadref(thref, shadow_pid(current->pid)); |
| 1203 | ptr = pack_threadid(ptr, thref); |
| 1204 | *ptr++ = ';'; |
| 1205 | put_packet(remcom_out_buffer); |
| 1206 | } |
| 1207 | |
| 1208 | kgdb_usethread = kgdb_info[ks->cpu].task; |
| 1209 | ks->kgdb_usethreadid = shadow_pid(kgdb_info[ks->cpu].task->pid); |
| 1210 | ks->pass_exception = 0; |
| 1211 | |
| 1212 | while (1) { |
| 1213 | error = 0; |
| 1214 | |
| 1215 | /* Clear the out buffer. */ |
| 1216 | memset(remcom_out_buffer, 0, sizeof(remcom_out_buffer)); |
| 1217 | |
| 1218 | get_packet(remcom_in_buffer); |
| 1219 | |
| 1220 | switch (remcom_in_buffer[0]) { |
| 1221 | case '?': /* gdbserial status */ |
| 1222 | gdb_cmd_status(ks); |
| 1223 | break; |
| 1224 | case 'g': /* return the value of the CPU registers */ |
| 1225 | gdb_cmd_getregs(ks); |
| 1226 | break; |
| 1227 | case 'G': /* set the value of the CPU registers - return OK */ |
| 1228 | gdb_cmd_setregs(ks); |
| 1229 | break; |
| 1230 | case 'm': /* mAA..AA,LLLL Read LLLL bytes at address AA..AA */ |
| 1231 | gdb_cmd_memread(ks); |
| 1232 | break; |
| 1233 | case 'M': /* MAA..AA,LLLL: Write LLLL bytes at address AA..AA */ |
| 1234 | gdb_cmd_memwrite(ks); |
| 1235 | break; |
| 1236 | case 'X': /* XAA..AA,LLLL: Write LLLL bytes at address AA..AA */ |
| 1237 | gdb_cmd_binwrite(ks); |
| 1238 | break; |
| 1239 | /* kill or detach. KGDB should treat this like a |
| 1240 | * continue. |
| 1241 | */ |
| 1242 | case 'D': /* Debugger detach */ |
| 1243 | case 'k': /* Debugger detach via kill */ |
| 1244 | gdb_cmd_detachkill(ks); |
| 1245 | goto default_handle; |
| 1246 | case 'R': /* Reboot */ |
| 1247 | if (gdb_cmd_reboot(ks)) |
| 1248 | goto default_handle; |
| 1249 | break; |
| 1250 | case 'q': /* query command */ |
| 1251 | gdb_cmd_query(ks); |
| 1252 | break; |
| 1253 | case 'H': /* task related */ |
| 1254 | gdb_cmd_task(ks); |
| 1255 | break; |
| 1256 | case 'T': /* Query thread status */ |
| 1257 | gdb_cmd_thread(ks); |
| 1258 | break; |
| 1259 | case 'z': /* Break point remove */ |
| 1260 | case 'Z': /* Break point set */ |
| 1261 | gdb_cmd_break(ks); |
| 1262 | break; |
| 1263 | case 'C': /* Exception passing */ |
| 1264 | tmp = gdb_cmd_exception_pass(ks); |
| 1265 | if (tmp > 0) |
| 1266 | goto default_handle; |
| 1267 | if (tmp == 0) |
| 1268 | break; |
| 1269 | /* Fall through on tmp < 0 */ |
| 1270 | case 'c': /* Continue packet */ |
| 1271 | case 's': /* Single step packet */ |
| 1272 | if (kgdb_contthread && kgdb_contthread != current) { |
| 1273 | /* Can't switch threads in kgdb */ |
| 1274 | error_packet(remcom_out_buffer, -EINVAL); |
| 1275 | break; |
| 1276 | } |
| 1277 | kgdb_activate_sw_breakpoints(); |
| 1278 | /* Fall through to default processing */ |
| 1279 | default: |
| 1280 | default_handle: |
| 1281 | error = kgdb_arch_handle_exception(ks->ex_vector, |
| 1282 | ks->signo, |
| 1283 | ks->err_code, |
| 1284 | remcom_in_buffer, |
| 1285 | remcom_out_buffer, |
| 1286 | ks->linux_regs); |
| 1287 | /* |
| 1288 | * Leave cmd processing on error, detach, |
| 1289 | * kill, continue, or single step. |
| 1290 | */ |
| 1291 | if (error >= 0 || remcom_in_buffer[0] == 'D' || |
| 1292 | remcom_in_buffer[0] == 'k') { |
| 1293 | error = 0; |
| 1294 | goto kgdb_exit; |
| 1295 | } |
| 1296 | |
| 1297 | } |
| 1298 | |
| 1299 | /* reply to the request */ |
| 1300 | put_packet(remcom_out_buffer); |
| 1301 | } |
| 1302 | |
| 1303 | kgdb_exit: |
| 1304 | if (ks->pass_exception) |
| 1305 | error = 1; |
| 1306 | return error; |
| 1307 | } |
| 1308 | |
| 1309 | static int kgdb_reenter_check(struct kgdb_state *ks) |
| 1310 | { |
| 1311 | unsigned long addr; |
| 1312 | |
| 1313 | if (atomic_read(&kgdb_active) != raw_smp_processor_id()) |
| 1314 | return 0; |
| 1315 | |
| 1316 | /* Panic on recursive debugger calls: */ |
| 1317 | exception_level++; |
| 1318 | addr = kgdb_arch_pc(ks->ex_vector, ks->linux_regs); |
| 1319 | kgdb_deactivate_sw_breakpoints(); |
| 1320 | |
| 1321 | /* |
| 1322 | * If the break point removed ok at the place exception |
| 1323 | * occurred, try to recover and print a warning to the end |
| 1324 | * user because the user planted a breakpoint in a place that |
| 1325 | * KGDB needs in order to function. |
| 1326 | */ |
| 1327 | if (kgdb_remove_sw_break(addr) == 0) { |
| 1328 | exception_level = 0; |
| 1329 | kgdb_skipexception(ks->ex_vector, ks->linux_regs); |
| 1330 | kgdb_activate_sw_breakpoints(); |
Jason Wessel | 67baf94 | 2008-02-15 14:55:55 -0600 | [diff] [blame] | 1331 | printk(KERN_CRIT "KGDB: re-enter error: breakpoint removed %lx\n", |
| 1332 | addr); |
Jason Wessel | dc7d552 | 2008-04-17 20:05:37 +0200 | [diff] [blame] | 1333 | WARN_ON_ONCE(1); |
| 1334 | |
| 1335 | return 1; |
| 1336 | } |
| 1337 | remove_all_break(); |
| 1338 | kgdb_skipexception(ks->ex_vector, ks->linux_regs); |
| 1339 | |
| 1340 | if (exception_level > 1) { |
| 1341 | dump_stack(); |
| 1342 | panic("Recursive entry to debugger"); |
| 1343 | } |
| 1344 | |
| 1345 | printk(KERN_CRIT "KGDB: re-enter exception: ALL breakpoints killed\n"); |
| 1346 | dump_stack(); |
| 1347 | panic("Recursive entry to debugger"); |
| 1348 | |
| 1349 | return 1; |
| 1350 | } |
| 1351 | |
| 1352 | /* |
| 1353 | * kgdb_handle_exception() - main entry point from a kernel exception |
| 1354 | * |
| 1355 | * Locking hierarchy: |
| 1356 | * interface locks, if any (begin_session) |
| 1357 | * kgdb lock (kgdb_active) |
| 1358 | */ |
| 1359 | int |
| 1360 | kgdb_handle_exception(int evector, int signo, int ecode, struct pt_regs *regs) |
| 1361 | { |
| 1362 | struct kgdb_state kgdb_var; |
| 1363 | struct kgdb_state *ks = &kgdb_var; |
| 1364 | unsigned long flags; |
| 1365 | int error = 0; |
| 1366 | int i, cpu; |
| 1367 | |
| 1368 | ks->cpu = raw_smp_processor_id(); |
| 1369 | ks->ex_vector = evector; |
| 1370 | ks->signo = signo; |
| 1371 | ks->ex_vector = evector; |
| 1372 | ks->err_code = ecode; |
| 1373 | ks->kgdb_usethreadid = 0; |
| 1374 | ks->linux_regs = regs; |
| 1375 | |
| 1376 | if (kgdb_reenter_check(ks)) |
| 1377 | return 0; /* Ouch, double exception ! */ |
| 1378 | |
| 1379 | acquirelock: |
| 1380 | /* |
| 1381 | * Interrupts will be restored by the 'trap return' code, except when |
| 1382 | * single stepping. |
| 1383 | */ |
| 1384 | local_irq_save(flags); |
| 1385 | |
| 1386 | cpu = raw_smp_processor_id(); |
| 1387 | |
| 1388 | /* |
| 1389 | * Acquire the kgdb_active lock: |
| 1390 | */ |
| 1391 | while (atomic_cmpxchg(&kgdb_active, -1, cpu) != -1) |
| 1392 | cpu_relax(); |
| 1393 | |
| 1394 | /* |
| 1395 | * Do not start the debugger connection on this CPU if the last |
| 1396 | * instance of the exception handler wanted to come into the |
| 1397 | * debugger on a different CPU via a single step |
| 1398 | */ |
| 1399 | if (atomic_read(&kgdb_cpu_doing_single_step) != -1 && |
| 1400 | atomic_read(&kgdb_cpu_doing_single_step) != cpu) { |
| 1401 | |
| 1402 | atomic_set(&kgdb_active, -1); |
Jason Wessel | 7c3078b | 2008-02-15 14:55:54 -0600 | [diff] [blame] | 1403 | clocksource_touch_watchdog(); |
Jason Wessel | dc7d552 | 2008-04-17 20:05:37 +0200 | [diff] [blame] | 1404 | local_irq_restore(flags); |
| 1405 | |
| 1406 | goto acquirelock; |
| 1407 | } |
| 1408 | |
| 1409 | if (!kgdb_io_ready(1)) { |
| 1410 | error = 1; |
| 1411 | goto kgdb_restore; /* No I/O connection, so resume the system */ |
| 1412 | } |
| 1413 | |
| 1414 | /* |
| 1415 | * Don't enter if we have hit a removed breakpoint. |
| 1416 | */ |
| 1417 | if (kgdb_skipexception(ks->ex_vector, ks->linux_regs)) |
| 1418 | goto kgdb_restore; |
| 1419 | |
| 1420 | /* Call the I/O driver's pre_exception routine */ |
| 1421 | if (kgdb_io_ops->pre_exception) |
| 1422 | kgdb_io_ops->pre_exception(); |
| 1423 | |
| 1424 | kgdb_info[ks->cpu].debuggerinfo = ks->linux_regs; |
| 1425 | kgdb_info[ks->cpu].task = current; |
| 1426 | |
| 1427 | kgdb_disable_hw_debug(ks->linux_regs); |
| 1428 | |
| 1429 | /* |
| 1430 | * Get the passive CPU lock which will hold all the non-primary |
| 1431 | * CPU in a spin state while the debugger is active |
| 1432 | */ |
| 1433 | if (!kgdb_single_step || !kgdb_contthread) { |
| 1434 | for (i = 0; i < NR_CPUS; i++) |
| 1435 | atomic_set(&passive_cpu_wait[i], 1); |
| 1436 | } |
| 1437 | |
Jason Wessel | dc7d552 | 2008-04-17 20:05:37 +0200 | [diff] [blame] | 1438 | /* |
| 1439 | * spin_lock code is good enough as a barrier so we don't |
| 1440 | * need one here: |
| 1441 | */ |
| 1442 | atomic_set(&cpu_in_kgdb[ks->cpu], 1); |
| 1443 | |
Jason Wessel | 56fb709 | 2008-04-01 16:55:27 -0500 | [diff] [blame] | 1444 | #ifdef CONFIG_SMP |
| 1445 | /* Signal the other CPUs to enter kgdb_wait() */ |
| 1446 | if ((!kgdb_single_step || !kgdb_contthread) && kgdb_do_roundup) |
| 1447 | kgdb_roundup_cpus(flags); |
| 1448 | #endif |
| 1449 | |
Jason Wessel | dc7d552 | 2008-04-17 20:05:37 +0200 | [diff] [blame] | 1450 | /* |
| 1451 | * Wait for the other CPUs to be notified and be waiting for us: |
| 1452 | */ |
| 1453 | for_each_online_cpu(i) { |
| 1454 | while (!atomic_read(&cpu_in_kgdb[i])) |
| 1455 | cpu_relax(); |
| 1456 | } |
| 1457 | |
| 1458 | /* |
| 1459 | * At this point the primary processor is completely |
| 1460 | * in the debugger and all secondary CPUs are quiescent |
| 1461 | */ |
| 1462 | kgdb_post_primary_code(ks->linux_regs, ks->ex_vector, ks->err_code); |
| 1463 | kgdb_deactivate_sw_breakpoints(); |
| 1464 | kgdb_single_step = 0; |
| 1465 | kgdb_contthread = NULL; |
| 1466 | exception_level = 0; |
| 1467 | |
| 1468 | /* Talk to debugger with gdbserial protocol */ |
| 1469 | error = gdb_serial_stub(ks); |
| 1470 | |
| 1471 | /* Call the I/O driver's post_exception routine */ |
| 1472 | if (kgdb_io_ops->post_exception) |
| 1473 | kgdb_io_ops->post_exception(); |
| 1474 | |
| 1475 | kgdb_info[ks->cpu].debuggerinfo = NULL; |
| 1476 | kgdb_info[ks->cpu].task = NULL; |
| 1477 | atomic_set(&cpu_in_kgdb[ks->cpu], 0); |
| 1478 | |
| 1479 | if (!kgdb_single_step || !kgdb_contthread) { |
| 1480 | for (i = NR_CPUS-1; i >= 0; i--) |
| 1481 | atomic_set(&passive_cpu_wait[i], 0); |
| 1482 | /* |
| 1483 | * Wait till all the CPUs have quit |
| 1484 | * from the debugger. |
| 1485 | */ |
| 1486 | for_each_online_cpu(i) { |
| 1487 | while (atomic_read(&cpu_in_kgdb[i])) |
| 1488 | cpu_relax(); |
| 1489 | } |
| 1490 | } |
| 1491 | |
| 1492 | kgdb_restore: |
| 1493 | /* Free kgdb_active */ |
| 1494 | atomic_set(&kgdb_active, -1); |
Jason Wessel | 7c3078b | 2008-02-15 14:55:54 -0600 | [diff] [blame] | 1495 | clocksource_touch_watchdog(); |
Jason Wessel | dc7d552 | 2008-04-17 20:05:37 +0200 | [diff] [blame] | 1496 | local_irq_restore(flags); |
| 1497 | |
| 1498 | return error; |
| 1499 | } |
| 1500 | |
| 1501 | int kgdb_nmicallback(int cpu, void *regs) |
| 1502 | { |
| 1503 | #ifdef CONFIG_SMP |
| 1504 | if (!atomic_read(&cpu_in_kgdb[cpu]) && |
Jason Wessel | 56fb709 | 2008-04-01 16:55:27 -0500 | [diff] [blame] | 1505 | atomic_read(&kgdb_active) != cpu && |
| 1506 | atomic_read(&cpu_in_kgdb[atomic_read(&kgdb_active)])) { |
Jason Wessel | dc7d552 | 2008-04-17 20:05:37 +0200 | [diff] [blame] | 1507 | kgdb_wait((struct pt_regs *)regs); |
| 1508 | return 0; |
| 1509 | } |
| 1510 | #endif |
| 1511 | return 1; |
| 1512 | } |
| 1513 | |
| 1514 | void kgdb_console_write(struct console *co, const char *s, unsigned count) |
| 1515 | { |
| 1516 | unsigned long flags; |
| 1517 | |
| 1518 | /* If we're debugging, or KGDB has not connected, don't try |
| 1519 | * and print. */ |
| 1520 | if (!kgdb_connected || atomic_read(&kgdb_active) != -1) |
| 1521 | return; |
| 1522 | |
| 1523 | local_irq_save(flags); |
| 1524 | kgdb_msg_write(s, count); |
| 1525 | local_irq_restore(flags); |
| 1526 | } |
| 1527 | |
| 1528 | static struct console kgdbcons = { |
| 1529 | .name = "kgdb", |
| 1530 | .write = kgdb_console_write, |
| 1531 | .flags = CON_PRINTBUFFER | CON_ENABLED, |
| 1532 | .index = -1, |
| 1533 | }; |
| 1534 | |
| 1535 | #ifdef CONFIG_MAGIC_SYSRQ |
| 1536 | static void sysrq_handle_gdb(int key, struct tty_struct *tty) |
| 1537 | { |
| 1538 | if (!kgdb_io_ops) { |
| 1539 | printk(KERN_CRIT "ERROR: No KGDB I/O module available\n"); |
| 1540 | return; |
| 1541 | } |
| 1542 | if (!kgdb_connected) |
| 1543 | printk(KERN_CRIT "Entering KGDB\n"); |
| 1544 | |
| 1545 | kgdb_breakpoint(); |
| 1546 | } |
| 1547 | |
| 1548 | static struct sysrq_key_op sysrq_gdb_op = { |
| 1549 | .handler = sysrq_handle_gdb, |
| 1550 | .help_msg = "Gdb", |
| 1551 | .action_msg = "GDB", |
| 1552 | }; |
| 1553 | #endif |
| 1554 | |
| 1555 | static void kgdb_register_callbacks(void) |
| 1556 | { |
| 1557 | if (!kgdb_io_module_registered) { |
| 1558 | kgdb_io_module_registered = 1; |
| 1559 | kgdb_arch_init(); |
| 1560 | #ifdef CONFIG_MAGIC_SYSRQ |
| 1561 | register_sysrq_key('g', &sysrq_gdb_op); |
| 1562 | #endif |
| 1563 | if (kgdb_use_con && !kgdb_con_registered) { |
| 1564 | register_console(&kgdbcons); |
| 1565 | kgdb_con_registered = 1; |
| 1566 | } |
| 1567 | } |
| 1568 | } |
| 1569 | |
| 1570 | static void kgdb_unregister_callbacks(void) |
| 1571 | { |
| 1572 | /* |
| 1573 | * When this routine is called KGDB should unregister from the |
| 1574 | * panic handler and clean up, making sure it is not handling any |
| 1575 | * break exceptions at the time. |
| 1576 | */ |
| 1577 | if (kgdb_io_module_registered) { |
| 1578 | kgdb_io_module_registered = 0; |
| 1579 | kgdb_arch_exit(); |
| 1580 | #ifdef CONFIG_MAGIC_SYSRQ |
| 1581 | unregister_sysrq_key('g', &sysrq_gdb_op); |
| 1582 | #endif |
| 1583 | if (kgdb_con_registered) { |
| 1584 | unregister_console(&kgdbcons); |
| 1585 | kgdb_con_registered = 0; |
| 1586 | } |
| 1587 | } |
| 1588 | } |
| 1589 | |
| 1590 | static void kgdb_initial_breakpoint(void) |
| 1591 | { |
| 1592 | kgdb_break_asap = 0; |
| 1593 | |
| 1594 | printk(KERN_CRIT "kgdb: Waiting for connection from remote gdb...\n"); |
| 1595 | kgdb_breakpoint(); |
| 1596 | } |
| 1597 | |
| 1598 | /** |
Jason Wessel | 737a460 | 2008-03-07 16:34:16 -0600 | [diff] [blame] | 1599 | * kgdb_register_io_module - register KGDB IO module |
Jason Wessel | dc7d552 | 2008-04-17 20:05:37 +0200 | [diff] [blame] | 1600 | * @new_kgdb_io_ops: the io ops vector |
| 1601 | * |
| 1602 | * Register it with the KGDB core. |
| 1603 | */ |
| 1604 | int kgdb_register_io_module(struct kgdb_io *new_kgdb_io_ops) |
| 1605 | { |
| 1606 | int err; |
| 1607 | |
| 1608 | spin_lock(&kgdb_registration_lock); |
| 1609 | |
| 1610 | if (kgdb_io_ops) { |
| 1611 | spin_unlock(&kgdb_registration_lock); |
| 1612 | |
| 1613 | printk(KERN_ERR "kgdb: Another I/O driver is already " |
| 1614 | "registered with KGDB.\n"); |
| 1615 | return -EBUSY; |
| 1616 | } |
| 1617 | |
| 1618 | if (new_kgdb_io_ops->init) { |
| 1619 | err = new_kgdb_io_ops->init(); |
| 1620 | if (err) { |
| 1621 | spin_unlock(&kgdb_registration_lock); |
| 1622 | return err; |
| 1623 | } |
| 1624 | } |
| 1625 | |
| 1626 | kgdb_io_ops = new_kgdb_io_ops; |
| 1627 | |
| 1628 | spin_unlock(&kgdb_registration_lock); |
| 1629 | |
| 1630 | printk(KERN_INFO "kgdb: Registered I/O driver %s.\n", |
| 1631 | new_kgdb_io_ops->name); |
| 1632 | |
| 1633 | /* Arm KGDB now. */ |
| 1634 | kgdb_register_callbacks(); |
| 1635 | |
| 1636 | if (kgdb_break_asap) |
| 1637 | kgdb_initial_breakpoint(); |
| 1638 | |
| 1639 | return 0; |
| 1640 | } |
| 1641 | EXPORT_SYMBOL_GPL(kgdb_register_io_module); |
| 1642 | |
| 1643 | /** |
| 1644 | * kkgdb_unregister_io_module - unregister KGDB IO module |
| 1645 | * @old_kgdb_io_ops: the io ops vector |
| 1646 | * |
| 1647 | * Unregister it with the KGDB core. |
| 1648 | */ |
| 1649 | void kgdb_unregister_io_module(struct kgdb_io *old_kgdb_io_ops) |
| 1650 | { |
| 1651 | BUG_ON(kgdb_connected); |
| 1652 | |
| 1653 | /* |
| 1654 | * KGDB is no longer able to communicate out, so |
| 1655 | * unregister our callbacks and reset state. |
| 1656 | */ |
| 1657 | kgdb_unregister_callbacks(); |
| 1658 | |
| 1659 | spin_lock(&kgdb_registration_lock); |
| 1660 | |
| 1661 | WARN_ON_ONCE(kgdb_io_ops != old_kgdb_io_ops); |
| 1662 | kgdb_io_ops = NULL; |
| 1663 | |
| 1664 | spin_unlock(&kgdb_registration_lock); |
| 1665 | |
| 1666 | printk(KERN_INFO |
| 1667 | "kgdb: Unregistered I/O driver %s, debugger disabled.\n", |
| 1668 | old_kgdb_io_ops->name); |
| 1669 | } |
| 1670 | EXPORT_SYMBOL_GPL(kgdb_unregister_io_module); |
| 1671 | |
| 1672 | /** |
| 1673 | * kgdb_breakpoint - generate breakpoint exception |
| 1674 | * |
| 1675 | * This function will generate a breakpoint exception. It is used at the |
| 1676 | * beginning of a program to sync up with a debugger and can be used |
| 1677 | * otherwise as a quick means to stop program execution and "break" into |
| 1678 | * the debugger. |
| 1679 | */ |
| 1680 | void kgdb_breakpoint(void) |
| 1681 | { |
| 1682 | atomic_set(&kgdb_setting_breakpoint, 1); |
| 1683 | wmb(); /* Sync point before breakpoint */ |
| 1684 | arch_kgdb_breakpoint(); |
| 1685 | wmb(); /* Sync point after breakpoint */ |
| 1686 | atomic_set(&kgdb_setting_breakpoint, 0); |
| 1687 | } |
| 1688 | EXPORT_SYMBOL_GPL(kgdb_breakpoint); |
| 1689 | |
| 1690 | static int __init opt_kgdb_wait(char *str) |
| 1691 | { |
| 1692 | kgdb_break_asap = 1; |
| 1693 | |
| 1694 | if (kgdb_io_module_registered) |
| 1695 | kgdb_initial_breakpoint(); |
| 1696 | |
| 1697 | return 0; |
| 1698 | } |
| 1699 | |
| 1700 | early_param("kgdbwait", opt_kgdb_wait); |