| 1 | /* |
| 2 | * linux/kernel/panic.c |
| 3 | * |
| 4 | * Copyright (C) 1991, 1992 Linus Torvalds |
| 5 | */ |
| 6 | |
| 7 | /* |
| 8 | * This function is used through-out the kernel (including mm and fs) |
| 9 | * to indicate a major problem. |
| 10 | */ |
| 11 | #include <linux/debug_locks.h> |
| 12 | #include <linux/sched/debug.h> |
| 13 | #include <linux/interrupt.h> |
| 14 | #include <linux/kmsg_dump.h> |
| 15 | #include <linux/kallsyms.h> |
| 16 | #include <linux/notifier.h> |
| 17 | #include <linux/module.h> |
| 18 | #include <linux/random.h> |
| 19 | #include <linux/ftrace.h> |
| 20 | #include <linux/reboot.h> |
| 21 | #include <linux/delay.h> |
| 22 | #include <linux/kexec.h> |
| 23 | #include <linux/sched.h> |
| 24 | #include <linux/sysrq.h> |
| 25 | #include <linux/init.h> |
| 26 | #include <linux/nmi.h> |
| 27 | #include <linux/console.h> |
| 28 | #include <linux/bug.h> |
| 29 | #include <linux/ratelimit.h> |
| 30 | #include <linux/debugfs.h> |
| 31 | #include <asm/sections.h> |
| 32 | |
| 33 | #define PANIC_TIMER_STEP 100 |
| 34 | #define PANIC_BLINK_SPD 18 |
| 35 | |
| 36 | int panic_on_oops = CONFIG_PANIC_ON_OOPS_VALUE; |
| 37 | static unsigned long tainted_mask = |
| 38 | IS_ENABLED(CONFIG_GCC_PLUGIN_RANDSTRUCT) ? (1 << TAINT_RANDSTRUCT) : 0; |
| 39 | static int pause_on_oops; |
| 40 | static int pause_on_oops_flag; |
| 41 | static DEFINE_SPINLOCK(pause_on_oops_lock); |
| 42 | bool crash_kexec_post_notifiers; |
| 43 | int panic_on_warn __read_mostly; |
| 44 | |
| 45 | int panic_timeout = CONFIG_PANIC_TIMEOUT; |
| 46 | EXPORT_SYMBOL_GPL(panic_timeout); |
| 47 | |
| 48 | ATOMIC_NOTIFIER_HEAD(panic_notifier_list); |
| 49 | |
| 50 | EXPORT_SYMBOL(panic_notifier_list); |
| 51 | |
| 52 | static long no_blink(int state) |
| 53 | { |
| 54 | return 0; |
| 55 | } |
| 56 | |
| 57 | /* Returns how long it waited in ms */ |
| 58 | long (*panic_blink)(int state); |
| 59 | EXPORT_SYMBOL(panic_blink); |
| 60 | |
| 61 | /* |
| 62 | * Stop ourself in panic -- architecture code may override this |
| 63 | */ |
| 64 | void __weak panic_smp_self_stop(void) |
| 65 | { |
| 66 | while (1) |
| 67 | cpu_relax(); |
| 68 | } |
| 69 | |
| 70 | /* |
| 71 | * Stop ourselves in NMI context if another CPU has already panicked. Arch code |
| 72 | * may override this to prepare for crash dumping, e.g. save regs info. |
| 73 | */ |
| 74 | void __weak nmi_panic_self_stop(struct pt_regs *regs) |
| 75 | { |
| 76 | panic_smp_self_stop(); |
| 77 | } |
| 78 | |
| 79 | /* |
| 80 | * Stop other CPUs in panic. Architecture dependent code may override this |
| 81 | * with more suitable version. For example, if the architecture supports |
| 82 | * crash dump, it should save registers of each stopped CPU and disable |
| 83 | * per-CPU features such as virtualization extensions. |
| 84 | */ |
| 85 | void __weak crash_smp_send_stop(void) |
| 86 | { |
| 87 | static int cpus_stopped; |
| 88 | |
| 89 | /* |
| 90 | * This function can be called twice in panic path, but obviously |
| 91 | * we execute this only once. |
| 92 | */ |
| 93 | if (cpus_stopped) |
| 94 | return; |
| 95 | |
| 96 | /* |
| 97 | * Note smp_send_stop is the usual smp shutdown function, which |
| 98 | * unfortunately means it may not be hardened to work in a panic |
| 99 | * situation. |
| 100 | */ |
| 101 | smp_send_stop(); |
| 102 | cpus_stopped = 1; |
| 103 | } |
| 104 | |
| 105 | atomic_t panic_cpu = ATOMIC_INIT(PANIC_CPU_INVALID); |
| 106 | |
| 107 | /* |
| 108 | * A variant of panic() called from NMI context. We return if we've already |
| 109 | * panicked on this CPU. If another CPU already panicked, loop in |
| 110 | * nmi_panic_self_stop() which can provide architecture dependent code such |
| 111 | * as saving register state for crash dump. |
| 112 | */ |
| 113 | void nmi_panic(struct pt_regs *regs, const char *msg) |
| 114 | { |
| 115 | int old_cpu, cpu; |
| 116 | |
| 117 | cpu = raw_smp_processor_id(); |
| 118 | old_cpu = atomic_cmpxchg(&panic_cpu, PANIC_CPU_INVALID, cpu); |
| 119 | |
| 120 | if (old_cpu == PANIC_CPU_INVALID) |
| 121 | panic("%s", msg); |
| 122 | else if (old_cpu != cpu) |
| 123 | nmi_panic_self_stop(regs); |
| 124 | } |
| 125 | EXPORT_SYMBOL(nmi_panic); |
| 126 | |
| 127 | /** |
| 128 | * panic - halt the system |
| 129 | * @fmt: The text string to print |
| 130 | * |
| 131 | * Display a message, then perform cleanups. |
| 132 | * |
| 133 | * This function never returns. |
| 134 | */ |
| 135 | void panic(const char *fmt, ...) |
| 136 | { |
| 137 | static char buf[1024]; |
| 138 | va_list args; |
| 139 | long i, i_next = 0; |
| 140 | int state = 0; |
| 141 | int old_cpu, this_cpu; |
| 142 | bool _crash_kexec_post_notifiers = crash_kexec_post_notifiers; |
| 143 | |
| 144 | /* |
| 145 | * Disable local interrupts. This will prevent panic_smp_self_stop |
| 146 | * from deadlocking the first cpu that invokes the panic, since |
| 147 | * there is nothing to prevent an interrupt handler (that runs |
| 148 | * after setting panic_cpu) from invoking panic() again. |
| 149 | */ |
| 150 | local_irq_disable(); |
| 151 | |
| 152 | /* |
| 153 | * It's possible to come here directly from a panic-assertion and |
| 154 | * not have preempt disabled. Some functions called from here want |
| 155 | * preempt to be disabled. No point enabling it later though... |
| 156 | * |
| 157 | * Only one CPU is allowed to execute the panic code from here. For |
| 158 | * multiple parallel invocations of panic, all other CPUs either |
| 159 | * stop themself or will wait until they are stopped by the 1st CPU |
| 160 | * with smp_send_stop(). |
| 161 | * |
| 162 | * `old_cpu == PANIC_CPU_INVALID' means this is the 1st CPU which |
| 163 | * comes here, so go ahead. |
| 164 | * `old_cpu == this_cpu' means we came from nmi_panic() which sets |
| 165 | * panic_cpu to this CPU. In this case, this is also the 1st CPU. |
| 166 | */ |
| 167 | this_cpu = raw_smp_processor_id(); |
| 168 | old_cpu = atomic_cmpxchg(&panic_cpu, PANIC_CPU_INVALID, this_cpu); |
| 169 | |
| 170 | if (old_cpu != PANIC_CPU_INVALID && old_cpu != this_cpu) |
| 171 | panic_smp_self_stop(); |
| 172 | |
| 173 | console_verbose(); |
| 174 | bust_spinlocks(1); |
| 175 | va_start(args, fmt); |
| 176 | vsnprintf(buf, sizeof(buf), fmt, args); |
| 177 | va_end(args); |
| 178 | pr_emerg("Kernel panic - not syncing: %s\n", buf); |
| 179 | #ifdef CONFIG_DEBUG_BUGVERBOSE |
| 180 | /* |
| 181 | * Avoid nested stack-dumping if a panic occurs during oops processing |
| 182 | */ |
| 183 | if (!test_taint(TAINT_DIE) && oops_in_progress <= 1) |
| 184 | dump_stack(); |
| 185 | #endif |
| 186 | |
| 187 | /* |
| 188 | * If we have crashed and we have a crash kernel loaded let it handle |
| 189 | * everything else. |
| 190 | * If we want to run this after calling panic_notifiers, pass |
| 191 | * the "crash_kexec_post_notifiers" option to the kernel. |
| 192 | * |
| 193 | * Bypass the panic_cpu check and call __crash_kexec directly. |
| 194 | */ |
| 195 | if (!_crash_kexec_post_notifiers) { |
| 196 | printk_safe_flush_on_panic(); |
| 197 | __crash_kexec(NULL); |
| 198 | |
| 199 | /* |
| 200 | * Note smp_send_stop is the usual smp shutdown function, which |
| 201 | * unfortunately means it may not be hardened to work in a |
| 202 | * panic situation. |
| 203 | */ |
| 204 | smp_send_stop(); |
| 205 | } else { |
| 206 | /* |
| 207 | * If we want to do crash dump after notifier calls and |
| 208 | * kmsg_dump, we will need architecture dependent extra |
| 209 | * works in addition to stopping other CPUs. |
| 210 | */ |
| 211 | crash_smp_send_stop(); |
| 212 | } |
| 213 | |
| 214 | /* |
| 215 | * Run any panic handlers, including those that might need to |
| 216 | * add information to the kmsg dump output. |
| 217 | */ |
| 218 | atomic_notifier_call_chain(&panic_notifier_list, 0, buf); |
| 219 | |
| 220 | /* Call flush even twice. It tries harder with a single online CPU */ |
| 221 | printk_safe_flush_on_panic(); |
| 222 | kmsg_dump(KMSG_DUMP_PANIC); |
| 223 | |
| 224 | /* |
| 225 | * If you doubt kdump always works fine in any situation, |
| 226 | * "crash_kexec_post_notifiers" offers you a chance to run |
| 227 | * panic_notifiers and dumping kmsg before kdump. |
| 228 | * Note: since some panic_notifiers can make crashed kernel |
| 229 | * more unstable, it can increase risks of the kdump failure too. |
| 230 | * |
| 231 | * Bypass the panic_cpu check and call __crash_kexec directly. |
| 232 | */ |
| 233 | if (_crash_kexec_post_notifiers) |
| 234 | __crash_kexec(NULL); |
| 235 | |
| 236 | bust_spinlocks(0); |
| 237 | |
| 238 | /* |
| 239 | * We may have ended up stopping the CPU holding the lock (in |
| 240 | * smp_send_stop()) while still having some valuable data in the console |
| 241 | * buffer. Try to acquire the lock then release it regardless of the |
| 242 | * result. The release will also print the buffers out. Locks debug |
| 243 | * should be disabled to avoid reporting bad unlock balance when |
| 244 | * panic() is not being callled from OOPS. |
| 245 | */ |
| 246 | debug_locks_off(); |
| 247 | console_flush_on_panic(); |
| 248 | |
| 249 | if (!panic_blink) |
| 250 | panic_blink = no_blink; |
| 251 | |
| 252 | if (panic_timeout > 0) { |
| 253 | /* |
| 254 | * Delay timeout seconds before rebooting the machine. |
| 255 | * We can't use the "normal" timers since we just panicked. |
| 256 | */ |
| 257 | pr_emerg("Rebooting in %d seconds..\n", panic_timeout); |
| 258 | |
| 259 | for (i = 0; i < panic_timeout * 1000; i += PANIC_TIMER_STEP) { |
| 260 | touch_nmi_watchdog(); |
| 261 | if (i >= i_next) { |
| 262 | i += panic_blink(state ^= 1); |
| 263 | i_next = i + 3600 / PANIC_BLINK_SPD; |
| 264 | } |
| 265 | mdelay(PANIC_TIMER_STEP); |
| 266 | } |
| 267 | } |
| 268 | if (panic_timeout != 0) { |
| 269 | /* |
| 270 | * This will not be a clean reboot, with everything |
| 271 | * shutting down. But if there is a chance of |
| 272 | * rebooting the system it will be rebooted. |
| 273 | */ |
| 274 | emergency_restart(); |
| 275 | } |
| 276 | #ifdef __sparc__ |
| 277 | { |
| 278 | extern int stop_a_enabled; |
| 279 | /* Make sure the user can actually press Stop-A (L1-A) */ |
| 280 | stop_a_enabled = 1; |
| 281 | pr_emerg("Press Stop-A (L1-A) from sun keyboard or send break\n" |
| 282 | "twice on console to return to the boot prom\n"); |
| 283 | } |
| 284 | #endif |
| 285 | #if defined(CONFIG_S390) |
| 286 | { |
| 287 | unsigned long caller; |
| 288 | |
| 289 | caller = (unsigned long)__builtin_return_address(0); |
| 290 | disabled_wait(caller); |
| 291 | } |
| 292 | #endif |
| 293 | pr_emerg("---[ end Kernel panic - not syncing: %s ]---\n", buf); |
| 294 | local_irq_enable(); |
| 295 | for (i = 0; ; i += PANIC_TIMER_STEP) { |
| 296 | touch_softlockup_watchdog(); |
| 297 | if (i >= i_next) { |
| 298 | i += panic_blink(state ^= 1); |
| 299 | i_next = i + 3600 / PANIC_BLINK_SPD; |
| 300 | } |
| 301 | mdelay(PANIC_TIMER_STEP); |
| 302 | } |
| 303 | } |
| 304 | |
| 305 | EXPORT_SYMBOL(panic); |
| 306 | |
| 307 | /* |
| 308 | * TAINT_FORCED_RMMOD could be a per-module flag but the module |
| 309 | * is being removed anyway. |
| 310 | */ |
| 311 | const struct taint_flag taint_flags[TAINT_FLAGS_COUNT] = { |
| 312 | [ TAINT_PROPRIETARY_MODULE ] = { 'P', 'G', true }, |
| 313 | [ TAINT_FORCED_MODULE ] = { 'F', ' ', true }, |
| 314 | [ TAINT_CPU_OUT_OF_SPEC ] = { 'S', ' ', false }, |
| 315 | [ TAINT_FORCED_RMMOD ] = { 'R', ' ', false }, |
| 316 | [ TAINT_MACHINE_CHECK ] = { 'M', ' ', false }, |
| 317 | [ TAINT_BAD_PAGE ] = { 'B', ' ', false }, |
| 318 | [ TAINT_USER ] = { 'U', ' ', false }, |
| 319 | [ TAINT_DIE ] = { 'D', ' ', false }, |
| 320 | [ TAINT_OVERRIDDEN_ACPI_TABLE ] = { 'A', ' ', false }, |
| 321 | [ TAINT_WARN ] = { 'W', ' ', false }, |
| 322 | [ TAINT_CRAP ] = { 'C', ' ', true }, |
| 323 | [ TAINT_FIRMWARE_WORKAROUND ] = { 'I', ' ', false }, |
| 324 | [ TAINT_OOT_MODULE ] = { 'O', ' ', true }, |
| 325 | [ TAINT_UNSIGNED_MODULE ] = { 'E', ' ', true }, |
| 326 | [ TAINT_SOFTLOCKUP ] = { 'L', ' ', false }, |
| 327 | [ TAINT_LIVEPATCH ] = { 'K', ' ', true }, |
| 328 | [ TAINT_AUX ] = { 'X', ' ', true }, |
| 329 | [ TAINT_RANDSTRUCT ] = { 'T', ' ', true }, |
| 330 | }; |
| 331 | |
| 332 | /** |
| 333 | * print_tainted - return a string to represent the kernel taint state. |
| 334 | * |
| 335 | * For individual taint flag meanings, see Documentation/sysctl/kernel.txt |
| 336 | * |
| 337 | * The string is overwritten by the next call to print_tainted(), |
| 338 | * but is always NULL terminated. |
| 339 | */ |
| 340 | const char *print_tainted(void) |
| 341 | { |
| 342 | static char buf[TAINT_FLAGS_COUNT + sizeof("Tainted: ")]; |
| 343 | |
| 344 | BUILD_BUG_ON(ARRAY_SIZE(taint_flags) != TAINT_FLAGS_COUNT); |
| 345 | |
| 346 | if (tainted_mask) { |
| 347 | char *s; |
| 348 | int i; |
| 349 | |
| 350 | s = buf + sprintf(buf, "Tainted: "); |
| 351 | for (i = 0; i < TAINT_FLAGS_COUNT; i++) { |
| 352 | const struct taint_flag *t = &taint_flags[i]; |
| 353 | *s++ = test_bit(i, &tainted_mask) ? |
| 354 | t->c_true : t->c_false; |
| 355 | } |
| 356 | *s = 0; |
| 357 | } else |
| 358 | snprintf(buf, sizeof(buf), "Not tainted"); |
| 359 | |
| 360 | return buf; |
| 361 | } |
| 362 | |
| 363 | int test_taint(unsigned flag) |
| 364 | { |
| 365 | return test_bit(flag, &tainted_mask); |
| 366 | } |
| 367 | EXPORT_SYMBOL(test_taint); |
| 368 | |
| 369 | unsigned long get_taint(void) |
| 370 | { |
| 371 | return tainted_mask; |
| 372 | } |
| 373 | |
| 374 | /** |
| 375 | * add_taint: add a taint flag if not already set. |
| 376 | * @flag: one of the TAINT_* constants. |
| 377 | * @lockdep_ok: whether lock debugging is still OK. |
| 378 | * |
| 379 | * If something bad has gone wrong, you'll want @lockdebug_ok = false, but for |
| 380 | * some notewortht-but-not-corrupting cases, it can be set to true. |
| 381 | */ |
| 382 | void add_taint(unsigned flag, enum lockdep_ok lockdep_ok) |
| 383 | { |
| 384 | if (lockdep_ok == LOCKDEP_NOW_UNRELIABLE && __debug_locks_off()) |
| 385 | pr_warn("Disabling lock debugging due to kernel taint\n"); |
| 386 | |
| 387 | set_bit(flag, &tainted_mask); |
| 388 | } |
| 389 | EXPORT_SYMBOL(add_taint); |
| 390 | |
| 391 | static void spin_msec(int msecs) |
| 392 | { |
| 393 | int i; |
| 394 | |
| 395 | for (i = 0; i < msecs; i++) { |
| 396 | touch_nmi_watchdog(); |
| 397 | mdelay(1); |
| 398 | } |
| 399 | } |
| 400 | |
| 401 | /* |
| 402 | * It just happens that oops_enter() and oops_exit() are identically |
| 403 | * implemented... |
| 404 | */ |
| 405 | static void do_oops_enter_exit(void) |
| 406 | { |
| 407 | unsigned long flags; |
| 408 | static int spin_counter; |
| 409 | |
| 410 | if (!pause_on_oops) |
| 411 | return; |
| 412 | |
| 413 | spin_lock_irqsave(&pause_on_oops_lock, flags); |
| 414 | if (pause_on_oops_flag == 0) { |
| 415 | /* This CPU may now print the oops message */ |
| 416 | pause_on_oops_flag = 1; |
| 417 | } else { |
| 418 | /* We need to stall this CPU */ |
| 419 | if (!spin_counter) { |
| 420 | /* This CPU gets to do the counting */ |
| 421 | spin_counter = pause_on_oops; |
| 422 | do { |
| 423 | spin_unlock(&pause_on_oops_lock); |
| 424 | spin_msec(MSEC_PER_SEC); |
| 425 | spin_lock(&pause_on_oops_lock); |
| 426 | } while (--spin_counter); |
| 427 | pause_on_oops_flag = 0; |
| 428 | } else { |
| 429 | /* This CPU waits for a different one */ |
| 430 | while (spin_counter) { |
| 431 | spin_unlock(&pause_on_oops_lock); |
| 432 | spin_msec(1); |
| 433 | spin_lock(&pause_on_oops_lock); |
| 434 | } |
| 435 | } |
| 436 | } |
| 437 | spin_unlock_irqrestore(&pause_on_oops_lock, flags); |
| 438 | } |
| 439 | |
| 440 | /* |
| 441 | * Return true if the calling CPU is allowed to print oops-related info. |
| 442 | * This is a bit racy.. |
| 443 | */ |
| 444 | int oops_may_print(void) |
| 445 | { |
| 446 | return pause_on_oops_flag == 0; |
| 447 | } |
| 448 | |
| 449 | /* |
| 450 | * Called when the architecture enters its oops handler, before it prints |
| 451 | * anything. If this is the first CPU to oops, and it's oopsing the first |
| 452 | * time then let it proceed. |
| 453 | * |
| 454 | * This is all enabled by the pause_on_oops kernel boot option. We do all |
| 455 | * this to ensure that oopses don't scroll off the screen. It has the |
| 456 | * side-effect of preventing later-oopsing CPUs from mucking up the display, |
| 457 | * too. |
| 458 | * |
| 459 | * It turns out that the CPU which is allowed to print ends up pausing for |
| 460 | * the right duration, whereas all the other CPUs pause for twice as long: |
| 461 | * once in oops_enter(), once in oops_exit(). |
| 462 | */ |
| 463 | void oops_enter(void) |
| 464 | { |
| 465 | tracing_off(); |
| 466 | /* can't trust the integrity of the kernel anymore: */ |
| 467 | debug_locks_off(); |
| 468 | do_oops_enter_exit(); |
| 469 | } |
| 470 | |
| 471 | /* |
| 472 | * 64-bit random ID for oopses: |
| 473 | */ |
| 474 | static u64 oops_id; |
| 475 | |
| 476 | static int init_oops_id(void) |
| 477 | { |
| 478 | if (!oops_id) |
| 479 | get_random_bytes(&oops_id, sizeof(oops_id)); |
| 480 | else |
| 481 | oops_id++; |
| 482 | |
| 483 | return 0; |
| 484 | } |
| 485 | late_initcall(init_oops_id); |
| 486 | |
| 487 | void print_oops_end_marker(void) |
| 488 | { |
| 489 | init_oops_id(); |
| 490 | pr_warn("---[ end trace %016llx ]---\n", (unsigned long long)oops_id); |
| 491 | } |
| 492 | |
| 493 | /* |
| 494 | * Called when the architecture exits its oops handler, after printing |
| 495 | * everything. |
| 496 | */ |
| 497 | void oops_exit(void) |
| 498 | { |
| 499 | do_oops_enter_exit(); |
| 500 | print_oops_end_marker(); |
| 501 | kmsg_dump(KMSG_DUMP_OOPS); |
| 502 | } |
| 503 | |
| 504 | struct warn_args { |
| 505 | const char *fmt; |
| 506 | va_list args; |
| 507 | }; |
| 508 | |
| 509 | void __warn(const char *file, int line, void *caller, unsigned taint, |
| 510 | struct pt_regs *regs, struct warn_args *args) |
| 511 | { |
| 512 | disable_trace_on_warning(); |
| 513 | |
| 514 | if (args) |
| 515 | pr_warn(CUT_HERE); |
| 516 | |
| 517 | if (file) |
| 518 | pr_warn("WARNING: CPU: %d PID: %d at %s:%d %pS\n", |
| 519 | raw_smp_processor_id(), current->pid, file, line, |
| 520 | caller); |
| 521 | else |
| 522 | pr_warn("WARNING: CPU: %d PID: %d at %pS\n", |
| 523 | raw_smp_processor_id(), current->pid, caller); |
| 524 | |
| 525 | if (args) |
| 526 | vprintk(args->fmt, args->args); |
| 527 | |
| 528 | if (panic_on_warn) { |
| 529 | /* |
| 530 | * This thread may hit another WARN() in the panic path. |
| 531 | * Resetting this prevents additional WARN() from panicking the |
| 532 | * system on this thread. Other threads are blocked by the |
| 533 | * panic_mutex in panic(). |
| 534 | */ |
| 535 | panic_on_warn = 0; |
| 536 | panic("panic_on_warn set ...\n"); |
| 537 | } |
| 538 | |
| 539 | print_modules(); |
| 540 | |
| 541 | if (regs) |
| 542 | show_regs(regs); |
| 543 | else |
| 544 | dump_stack(); |
| 545 | |
| 546 | print_irqtrace_events(current); |
| 547 | |
| 548 | print_oops_end_marker(); |
| 549 | |
| 550 | /* Just a warning, don't kill lockdep. */ |
| 551 | add_taint(taint, LOCKDEP_STILL_OK); |
| 552 | } |
| 553 | |
| 554 | #ifdef WANT_WARN_ON_SLOWPATH |
| 555 | void warn_slowpath_fmt(const char *file, int line, const char *fmt, ...) |
| 556 | { |
| 557 | struct warn_args args; |
| 558 | |
| 559 | args.fmt = fmt; |
| 560 | va_start(args.args, fmt); |
| 561 | __warn(file, line, __builtin_return_address(0), TAINT_WARN, NULL, |
| 562 | &args); |
| 563 | va_end(args.args); |
| 564 | } |
| 565 | EXPORT_SYMBOL(warn_slowpath_fmt); |
| 566 | |
| 567 | void warn_slowpath_fmt_taint(const char *file, int line, |
| 568 | unsigned taint, const char *fmt, ...) |
| 569 | { |
| 570 | struct warn_args args; |
| 571 | |
| 572 | args.fmt = fmt; |
| 573 | va_start(args.args, fmt); |
| 574 | __warn(file, line, __builtin_return_address(0), taint, NULL, &args); |
| 575 | va_end(args.args); |
| 576 | } |
| 577 | EXPORT_SYMBOL(warn_slowpath_fmt_taint); |
| 578 | |
| 579 | void warn_slowpath_null(const char *file, int line) |
| 580 | { |
| 581 | pr_warn(CUT_HERE); |
| 582 | __warn(file, line, __builtin_return_address(0), TAINT_WARN, NULL, NULL); |
| 583 | } |
| 584 | EXPORT_SYMBOL(warn_slowpath_null); |
| 585 | #else |
| 586 | void __warn_printk(const char *fmt, ...) |
| 587 | { |
| 588 | va_list args; |
| 589 | |
| 590 | pr_warn(CUT_HERE); |
| 591 | |
| 592 | va_start(args, fmt); |
| 593 | vprintk(fmt, args); |
| 594 | va_end(args); |
| 595 | } |
| 596 | EXPORT_SYMBOL(__warn_printk); |
| 597 | #endif |
| 598 | |
| 599 | #ifdef CONFIG_BUG |
| 600 | |
| 601 | /* Support resetting WARN*_ONCE state */ |
| 602 | |
| 603 | static int clear_warn_once_set(void *data, u64 val) |
| 604 | { |
| 605 | generic_bug_clear_once(); |
| 606 | memset(__start_once, 0, __end_once - __start_once); |
| 607 | return 0; |
| 608 | } |
| 609 | |
| 610 | DEFINE_SIMPLE_ATTRIBUTE(clear_warn_once_fops, |
| 611 | NULL, |
| 612 | clear_warn_once_set, |
| 613 | "%lld\n"); |
| 614 | |
| 615 | static __init int register_warn_debugfs(void) |
| 616 | { |
| 617 | /* Don't care about failure */ |
| 618 | debugfs_create_file("clear_warn_once", 0200, NULL, |
| 619 | NULL, &clear_warn_once_fops); |
| 620 | return 0; |
| 621 | } |
| 622 | |
| 623 | device_initcall(register_warn_debugfs); |
| 624 | #endif |
| 625 | |
| 626 | #ifdef CONFIG_CC_STACKPROTECTOR |
| 627 | |
| 628 | /* |
| 629 | * Called when gcc's -fstack-protector feature is used, and |
| 630 | * gcc detects corruption of the on-stack canary value |
| 631 | */ |
| 632 | __visible void __stack_chk_fail(void) |
| 633 | { |
| 634 | panic("stack-protector: Kernel stack is corrupted in: %pB\n", |
| 635 | __builtin_return_address(0)); |
| 636 | } |
| 637 | EXPORT_SYMBOL(__stack_chk_fail); |
| 638 | |
| 639 | #endif |
| 640 | |
| 641 | #ifdef CONFIG_ARCH_HAS_REFCOUNT |
| 642 | void refcount_error_report(struct pt_regs *regs, const char *err) |
| 643 | { |
| 644 | WARN_RATELIMIT(1, "refcount_t %s at %pB in %s[%d], uid/euid: %u/%u\n", |
| 645 | err, (void *)instruction_pointer(regs), |
| 646 | current->comm, task_pid_nr(current), |
| 647 | from_kuid_munged(&init_user_ns, current_uid()), |
| 648 | from_kuid_munged(&init_user_ns, current_euid())); |
| 649 | } |
| 650 | #endif |
| 651 | |
| 652 | core_param(panic, panic_timeout, int, 0644); |
| 653 | core_param(pause_on_oops, pause_on_oops, int, 0644); |
| 654 | core_param(panic_on_warn, panic_on_warn, int, 0644); |
| 655 | core_param(crash_kexec_post_notifiers, crash_kexec_post_notifiers, bool, 0644); |
| 656 | |
| 657 | static int __init oops_setup(char *s) |
| 658 | { |
| 659 | if (!s) |
| 660 | return -EINVAL; |
| 661 | if (!strcmp(s, "panic")) |
| 662 | panic_on_oops = 1; |
| 663 | return 0; |
| 664 | } |
| 665 | early_param("oops", oops_setup); |