1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * linux/kernel/panic.c 4 * 5 * Copyright (C) 1991, 1992 Linus Torvalds 6 */ 7 8 /* 9 * This function is used through-out the kernel (including mm and fs) 10 * to indicate a major problem. 11 */ 12 #include <linux/debug_locks.h> 13 #include <linux/sched/debug.h> 14 #include <linux/interrupt.h> 15 #include <linux/kgdb.h> 16 #include <linux/kmsg_dump.h> 17 #include <linux/kallsyms.h> 18 #include <linux/notifier.h> 19 #include <linux/vt_kern.h> 20 #include <linux/module.h> 21 #include <linux/random.h> 22 #include <linux/ftrace.h> 23 #include <linux/reboot.h> 24 #include <linux/delay.h> 25 #include <linux/kexec.h> 26 #include <linux/panic_notifier.h> 27 #include <linux/sched.h> 28 #include <linux/sysrq.h> 29 #include <linux/init.h> 30 #include <linux/nmi.h> 31 #include <linux/console.h> 32 #include <linux/bug.h> 33 #include <linux/ratelimit.h> 34 #include <linux/debugfs.h> 35 #include <trace/events/error_report.h> 36 #include <asm/sections.h> 37 38 #define PANIC_TIMER_STEP 100 39 #define PANIC_BLINK_SPD 18 40 41 #ifdef CONFIG_SMP 42 /* 43 * Should we dump all CPUs backtraces in an oops event? 44 * Defaults to 0, can be changed via sysctl. 45 */ 46 static unsigned int __read_mostly sysctl_oops_all_cpu_backtrace; 47 #else 48 #define sysctl_oops_all_cpu_backtrace 0 49 #endif /* CONFIG_SMP */ 50 51 int panic_on_oops = CONFIG_PANIC_ON_OOPS_VALUE; 52 static unsigned long tainted_mask = 53 IS_ENABLED(CONFIG_RANDSTRUCT) ? (1 << TAINT_RANDSTRUCT) : 0; 54 static int pause_on_oops; 55 static int pause_on_oops_flag; 56 static DEFINE_SPINLOCK(pause_on_oops_lock); 57 bool crash_kexec_post_notifiers; 58 int panic_on_warn __read_mostly; 59 unsigned long panic_on_taint; 60 bool panic_on_taint_nousertaint = false; 61 62 int panic_timeout = CONFIG_PANIC_TIMEOUT; 63 EXPORT_SYMBOL_GPL(panic_timeout); 64 65 #define PANIC_PRINT_TASK_INFO 0x00000001 66 #define PANIC_PRINT_MEM_INFO 0x00000002 67 #define PANIC_PRINT_TIMER_INFO 0x00000004 68 #define PANIC_PRINT_LOCK_INFO 0x00000008 69 #define PANIC_PRINT_FTRACE_INFO 0x00000010 70 #define PANIC_PRINT_ALL_PRINTK_MSG 0x00000020 71 #define PANIC_PRINT_ALL_CPU_BT 0x00000040 72 unsigned long panic_print; 73 74 ATOMIC_NOTIFIER_HEAD(panic_notifier_list); 75 76 EXPORT_SYMBOL(panic_notifier_list); 77 78 #if defined(CONFIG_SMP) && defined(CONFIG_SYSCTL) 79 static struct ctl_table kern_panic_table[] = { 80 { 81 .procname = "oops_all_cpu_backtrace", 82 .data = &sysctl_oops_all_cpu_backtrace, 83 .maxlen = sizeof(int), 84 .mode = 0644, 85 .proc_handler = proc_dointvec_minmax, 86 .extra1 = SYSCTL_ZERO, 87 .extra2 = SYSCTL_ONE, 88 }, 89 { } 90 }; 91 92 static __init int kernel_panic_sysctls_init(void) 93 { 94 register_sysctl_init("kernel", kern_panic_table); 95 return 0; 96 } 97 late_initcall(kernel_panic_sysctls_init); 98 #endif 99 100 static long no_blink(int state) 101 { 102 return 0; 103 } 104 105 /* Returns how long it waited in ms */ 106 long (*panic_blink)(int state); 107 EXPORT_SYMBOL(panic_blink); 108 109 /* 110 * Stop ourself in panic -- architecture code may override this 111 */ 112 void __weak panic_smp_self_stop(void) 113 { 114 while (1) 115 cpu_relax(); 116 } 117 118 /* 119 * Stop ourselves in NMI context if another CPU has already panicked. Arch code 120 * may override this to prepare for crash dumping, e.g. save regs info. 121 */ 122 void __weak nmi_panic_self_stop(struct pt_regs *regs) 123 { 124 panic_smp_self_stop(); 125 } 126 127 /* 128 * Stop other CPUs in panic. Architecture dependent code may override this 129 * with more suitable version. For example, if the architecture supports 130 * crash dump, it should save registers of each stopped CPU and disable 131 * per-CPU features such as virtualization extensions. 132 */ 133 void __weak crash_smp_send_stop(void) 134 { 135 static int cpus_stopped; 136 137 /* 138 * This function can be called twice in panic path, but obviously 139 * we execute this only once. 140 */ 141 if (cpus_stopped) 142 return; 143 144 /* 145 * Note smp_send_stop is the usual smp shutdown function, which 146 * unfortunately means it may not be hardened to work in a panic 147 * situation. 148 */ 149 smp_send_stop(); 150 cpus_stopped = 1; 151 } 152 153 atomic_t panic_cpu = ATOMIC_INIT(PANIC_CPU_INVALID); 154 155 /* 156 * A variant of panic() called from NMI context. We return if we've already 157 * panicked on this CPU. If another CPU already panicked, loop in 158 * nmi_panic_self_stop() which can provide architecture dependent code such 159 * as saving register state for crash dump. 160 */ 161 void nmi_panic(struct pt_regs *regs, const char *msg) 162 { 163 int old_cpu, cpu; 164 165 cpu = raw_smp_processor_id(); 166 old_cpu = atomic_cmpxchg(&panic_cpu, PANIC_CPU_INVALID, cpu); 167 168 if (old_cpu == PANIC_CPU_INVALID) 169 panic("%s", msg); 170 else if (old_cpu != cpu) 171 nmi_panic_self_stop(regs); 172 } 173 EXPORT_SYMBOL(nmi_panic); 174 175 static void panic_print_sys_info(bool console_flush) 176 { 177 if (console_flush) { 178 if (panic_print & PANIC_PRINT_ALL_PRINTK_MSG) 179 console_flush_on_panic(CONSOLE_REPLAY_ALL); 180 return; 181 } 182 183 if (panic_print & PANIC_PRINT_ALL_CPU_BT) 184 trigger_all_cpu_backtrace(); 185 186 if (panic_print & PANIC_PRINT_TASK_INFO) 187 show_state(); 188 189 if (panic_print & PANIC_PRINT_MEM_INFO) 190 show_mem(0, NULL); 191 192 if (panic_print & PANIC_PRINT_TIMER_INFO) 193 sysrq_timer_list_show(); 194 195 if (panic_print & PANIC_PRINT_LOCK_INFO) 196 debug_show_all_locks(); 197 198 if (panic_print & PANIC_PRINT_FTRACE_INFO) 199 ftrace_dump(DUMP_ALL); 200 } 201 202 /** 203 * panic - halt the system 204 * @fmt: The text string to print 205 * 206 * Display a message, then perform cleanups. 207 * 208 * This function never returns. 209 */ 210 void panic(const char *fmt, ...) 211 { 212 static char buf[1024]; 213 va_list args; 214 long i, i_next = 0, len; 215 int state = 0; 216 int old_cpu, this_cpu; 217 bool _crash_kexec_post_notifiers = crash_kexec_post_notifiers; 218 219 if (panic_on_warn) { 220 /* 221 * This thread may hit another WARN() in the panic path. 222 * Resetting this prevents additional WARN() from panicking the 223 * system on this thread. Other threads are blocked by the 224 * panic_mutex in panic(). 225 */ 226 panic_on_warn = 0; 227 } 228 229 /* 230 * Disable local interrupts. This will prevent panic_smp_self_stop 231 * from deadlocking the first cpu that invokes the panic, since 232 * there is nothing to prevent an interrupt handler (that runs 233 * after setting panic_cpu) from invoking panic() again. 234 */ 235 local_irq_disable(); 236 preempt_disable_notrace(); 237 238 /* 239 * It's possible to come here directly from a panic-assertion and 240 * not have preempt disabled. Some functions called from here want 241 * preempt to be disabled. No point enabling it later though... 242 * 243 * Only one CPU is allowed to execute the panic code from here. For 244 * multiple parallel invocations of panic, all other CPUs either 245 * stop themself or will wait until they are stopped by the 1st CPU 246 * with smp_send_stop(). 247 * 248 * `old_cpu == PANIC_CPU_INVALID' means this is the 1st CPU which 249 * comes here, so go ahead. 250 * `old_cpu == this_cpu' means we came from nmi_panic() which sets 251 * panic_cpu to this CPU. In this case, this is also the 1st CPU. 252 */ 253 this_cpu = raw_smp_processor_id(); 254 old_cpu = atomic_cmpxchg(&panic_cpu, PANIC_CPU_INVALID, this_cpu); 255 256 if (old_cpu != PANIC_CPU_INVALID && old_cpu != this_cpu) 257 panic_smp_self_stop(); 258 259 console_verbose(); 260 bust_spinlocks(1); 261 va_start(args, fmt); 262 len = vscnprintf(buf, sizeof(buf), fmt, args); 263 va_end(args); 264 265 if (len && buf[len - 1] == '\n') 266 buf[len - 1] = '\0'; 267 268 pr_emerg("Kernel panic - not syncing: %s\n", buf); 269 #ifdef CONFIG_DEBUG_BUGVERBOSE 270 /* 271 * Avoid nested stack-dumping if a panic occurs during oops processing 272 */ 273 if (!test_taint(TAINT_DIE) && oops_in_progress <= 1) 274 dump_stack(); 275 #endif 276 277 /* 278 * If kgdb is enabled, give it a chance to run before we stop all 279 * the other CPUs or else we won't be able to debug processes left 280 * running on them. 281 */ 282 kgdb_panic(buf); 283 284 /* 285 * If we have crashed and we have a crash kernel loaded let it handle 286 * everything else. 287 * If we want to run this after calling panic_notifiers, pass 288 * the "crash_kexec_post_notifiers" option to the kernel. 289 * 290 * Bypass the panic_cpu check and call __crash_kexec directly. 291 */ 292 if (!_crash_kexec_post_notifiers) { 293 __crash_kexec(NULL); 294 295 /* 296 * Note smp_send_stop is the usual smp shutdown function, which 297 * unfortunately means it may not be hardened to work in a 298 * panic situation. 299 */ 300 smp_send_stop(); 301 } else { 302 /* 303 * If we want to do crash dump after notifier calls and 304 * kmsg_dump, we will need architecture dependent extra 305 * works in addition to stopping other CPUs. 306 */ 307 crash_smp_send_stop(); 308 } 309 310 /* 311 * Run any panic handlers, including those that might need to 312 * add information to the kmsg dump output. 313 */ 314 atomic_notifier_call_chain(&panic_notifier_list, 0, buf); 315 316 panic_print_sys_info(false); 317 318 kmsg_dump(KMSG_DUMP_PANIC); 319 320 /* 321 * If you doubt kdump always works fine in any situation, 322 * "crash_kexec_post_notifiers" offers you a chance to run 323 * panic_notifiers and dumping kmsg before kdump. 324 * Note: since some panic_notifiers can make crashed kernel 325 * more unstable, it can increase risks of the kdump failure too. 326 * 327 * Bypass the panic_cpu check and call __crash_kexec directly. 328 */ 329 if (_crash_kexec_post_notifiers) 330 __crash_kexec(NULL); 331 332 console_unblank(); 333 334 /* 335 * We may have ended up stopping the CPU holding the lock (in 336 * smp_send_stop()) while still having some valuable data in the console 337 * buffer. Try to acquire the lock then release it regardless of the 338 * result. The release will also print the buffers out. Locks debug 339 * should be disabled to avoid reporting bad unlock balance when 340 * panic() is not being callled from OOPS. 341 */ 342 debug_locks_off(); 343 console_flush_on_panic(CONSOLE_FLUSH_PENDING); 344 345 panic_print_sys_info(true); 346 347 if (!panic_blink) 348 panic_blink = no_blink; 349 350 if (panic_timeout > 0) { 351 /* 352 * Delay timeout seconds before rebooting the machine. 353 * We can't use the "normal" timers since we just panicked. 354 */ 355 pr_emerg("Rebooting in %d seconds..\n", panic_timeout); 356 357 for (i = 0; i < panic_timeout * 1000; i += PANIC_TIMER_STEP) { 358 touch_nmi_watchdog(); 359 if (i >= i_next) { 360 i += panic_blink(state ^= 1); 361 i_next = i + 3600 / PANIC_BLINK_SPD; 362 } 363 mdelay(PANIC_TIMER_STEP); 364 } 365 } 366 if (panic_timeout != 0) { 367 /* 368 * This will not be a clean reboot, with everything 369 * shutting down. But if there is a chance of 370 * rebooting the system it will be rebooted. 371 */ 372 if (panic_reboot_mode != REBOOT_UNDEFINED) 373 reboot_mode = panic_reboot_mode; 374 emergency_restart(); 375 } 376 #ifdef __sparc__ 377 { 378 extern int stop_a_enabled; 379 /* Make sure the user can actually press Stop-A (L1-A) */ 380 stop_a_enabled = 1; 381 pr_emerg("Press Stop-A (L1-A) from sun keyboard or send break\n" 382 "twice on console to return to the boot prom\n"); 383 } 384 #endif 385 #if defined(CONFIG_S390) 386 disabled_wait(); 387 #endif 388 pr_emerg("---[ end Kernel panic - not syncing: %s ]---\n", buf); 389 390 /* Do not scroll important messages printed above */ 391 suppress_printk = 1; 392 local_irq_enable(); 393 for (i = 0; ; i += PANIC_TIMER_STEP) { 394 touch_softlockup_watchdog(); 395 if (i >= i_next) { 396 i += panic_blink(state ^= 1); 397 i_next = i + 3600 / PANIC_BLINK_SPD; 398 } 399 mdelay(PANIC_TIMER_STEP); 400 } 401 } 402 403 EXPORT_SYMBOL(panic); 404 405 /* 406 * TAINT_FORCED_RMMOD could be a per-module flag but the module 407 * is being removed anyway. 408 */ 409 const struct taint_flag taint_flags[TAINT_FLAGS_COUNT] = { 410 [ TAINT_PROPRIETARY_MODULE ] = { 'P', 'G', true }, 411 [ TAINT_FORCED_MODULE ] = { 'F', ' ', true }, 412 [ TAINT_CPU_OUT_OF_SPEC ] = { 'S', ' ', false }, 413 [ TAINT_FORCED_RMMOD ] = { 'R', ' ', false }, 414 [ TAINT_MACHINE_CHECK ] = { 'M', ' ', false }, 415 [ TAINT_BAD_PAGE ] = { 'B', ' ', false }, 416 [ TAINT_USER ] = { 'U', ' ', false }, 417 [ TAINT_DIE ] = { 'D', ' ', false }, 418 [ TAINT_OVERRIDDEN_ACPI_TABLE ] = { 'A', ' ', false }, 419 [ TAINT_WARN ] = { 'W', ' ', false }, 420 [ TAINT_CRAP ] = { 'C', ' ', true }, 421 [ TAINT_FIRMWARE_WORKAROUND ] = { 'I', ' ', false }, 422 [ TAINT_OOT_MODULE ] = { 'O', ' ', true }, 423 [ TAINT_UNSIGNED_MODULE ] = { 'E', ' ', true }, 424 [ TAINT_SOFTLOCKUP ] = { 'L', ' ', false }, 425 [ TAINT_LIVEPATCH ] = { 'K', ' ', true }, 426 [ TAINT_AUX ] = { 'X', ' ', true }, 427 [ TAINT_RANDSTRUCT ] = { 'T', ' ', true }, 428 [ TAINT_TEST ] = { 'N', ' ', true }, 429 }; 430 431 /** 432 * print_tainted - return a string to represent the kernel taint state. 433 * 434 * For individual taint flag meanings, see Documentation/admin-guide/sysctl/kernel.rst 435 * 436 * The string is overwritten by the next call to print_tainted(), 437 * but is always NULL terminated. 438 */ 439 const char *print_tainted(void) 440 { 441 static char buf[TAINT_FLAGS_COUNT + sizeof("Tainted: ")]; 442 443 BUILD_BUG_ON(ARRAY_SIZE(taint_flags) != TAINT_FLAGS_COUNT); 444 445 if (tainted_mask) { 446 char *s; 447 int i; 448 449 s = buf + sprintf(buf, "Tainted: "); 450 for (i = 0; i < TAINT_FLAGS_COUNT; i++) { 451 const struct taint_flag *t = &taint_flags[i]; 452 *s++ = test_bit(i, &tainted_mask) ? 453 t->c_true : t->c_false; 454 } 455 *s = 0; 456 } else 457 snprintf(buf, sizeof(buf), "Not tainted"); 458 459 return buf; 460 } 461 462 int test_taint(unsigned flag) 463 { 464 return test_bit(flag, &tainted_mask); 465 } 466 EXPORT_SYMBOL(test_taint); 467 468 unsigned long get_taint(void) 469 { 470 return tainted_mask; 471 } 472 473 /** 474 * add_taint: add a taint flag if not already set. 475 * @flag: one of the TAINT_* constants. 476 * @lockdep_ok: whether lock debugging is still OK. 477 * 478 * If something bad has gone wrong, you'll want @lockdebug_ok = false, but for 479 * some notewortht-but-not-corrupting cases, it can be set to true. 480 */ 481 void add_taint(unsigned flag, enum lockdep_ok lockdep_ok) 482 { 483 if (lockdep_ok == LOCKDEP_NOW_UNRELIABLE && __debug_locks_off()) 484 pr_warn("Disabling lock debugging due to kernel taint\n"); 485 486 set_bit(flag, &tainted_mask); 487 488 if (tainted_mask & panic_on_taint) { 489 panic_on_taint = 0; 490 panic("panic_on_taint set ..."); 491 } 492 } 493 EXPORT_SYMBOL(add_taint); 494 495 static void spin_msec(int msecs) 496 { 497 int i; 498 499 for (i = 0; i < msecs; i++) { 500 touch_nmi_watchdog(); 501 mdelay(1); 502 } 503 } 504 505 /* 506 * It just happens that oops_enter() and oops_exit() are identically 507 * implemented... 508 */ 509 static void do_oops_enter_exit(void) 510 { 511 unsigned long flags; 512 static int spin_counter; 513 514 if (!pause_on_oops) 515 return; 516 517 spin_lock_irqsave(&pause_on_oops_lock, flags); 518 if (pause_on_oops_flag == 0) { 519 /* This CPU may now print the oops message */ 520 pause_on_oops_flag = 1; 521 } else { 522 /* We need to stall this CPU */ 523 if (!spin_counter) { 524 /* This CPU gets to do the counting */ 525 spin_counter = pause_on_oops; 526 do { 527 spin_unlock(&pause_on_oops_lock); 528 spin_msec(MSEC_PER_SEC); 529 spin_lock(&pause_on_oops_lock); 530 } while (--spin_counter); 531 pause_on_oops_flag = 0; 532 } else { 533 /* This CPU waits for a different one */ 534 while (spin_counter) { 535 spin_unlock(&pause_on_oops_lock); 536 spin_msec(1); 537 spin_lock(&pause_on_oops_lock); 538 } 539 } 540 } 541 spin_unlock_irqrestore(&pause_on_oops_lock, flags); 542 } 543 544 /* 545 * Return true if the calling CPU is allowed to print oops-related info. 546 * This is a bit racy.. 547 */ 548 bool oops_may_print(void) 549 { 550 return pause_on_oops_flag == 0; 551 } 552 553 /* 554 * Called when the architecture enters its oops handler, before it prints 555 * anything. If this is the first CPU to oops, and it's oopsing the first 556 * time then let it proceed. 557 * 558 * This is all enabled by the pause_on_oops kernel boot option. We do all 559 * this to ensure that oopses don't scroll off the screen. It has the 560 * side-effect of preventing later-oopsing CPUs from mucking up the display, 561 * too. 562 * 563 * It turns out that the CPU which is allowed to print ends up pausing for 564 * the right duration, whereas all the other CPUs pause for twice as long: 565 * once in oops_enter(), once in oops_exit(). 566 */ 567 void oops_enter(void) 568 { 569 tracing_off(); 570 /* can't trust the integrity of the kernel anymore: */ 571 debug_locks_off(); 572 do_oops_enter_exit(); 573 574 if (sysctl_oops_all_cpu_backtrace) 575 trigger_all_cpu_backtrace(); 576 } 577 578 static void print_oops_end_marker(void) 579 { 580 pr_warn("---[ end trace %016llx ]---\n", 0ULL); 581 } 582 583 /* 584 * Called when the architecture exits its oops handler, after printing 585 * everything. 586 */ 587 void oops_exit(void) 588 { 589 do_oops_enter_exit(); 590 print_oops_end_marker(); 591 kmsg_dump(KMSG_DUMP_OOPS); 592 } 593 594 struct warn_args { 595 const char *fmt; 596 va_list args; 597 }; 598 599 void __warn(const char *file, int line, void *caller, unsigned taint, 600 struct pt_regs *regs, struct warn_args *args) 601 { 602 disable_trace_on_warning(); 603 604 if (file) 605 pr_warn("WARNING: CPU: %d PID: %d at %s:%d %pS\n", 606 raw_smp_processor_id(), current->pid, file, line, 607 caller); 608 else 609 pr_warn("WARNING: CPU: %d PID: %d at %pS\n", 610 raw_smp_processor_id(), current->pid, caller); 611 612 if (args) 613 vprintk(args->fmt, args->args); 614 615 print_modules(); 616 617 if (regs) 618 show_regs(regs); 619 620 if (panic_on_warn) 621 panic("panic_on_warn set ...\n"); 622 623 if (!regs) 624 dump_stack(); 625 626 print_irqtrace_events(current); 627 628 print_oops_end_marker(); 629 trace_error_report_end(ERROR_DETECTOR_WARN, (unsigned long)caller); 630 631 /* Just a warning, don't kill lockdep. */ 632 add_taint(taint, LOCKDEP_STILL_OK); 633 } 634 635 #ifndef __WARN_FLAGS 636 void warn_slowpath_fmt(const char *file, int line, unsigned taint, 637 const char *fmt, ...) 638 { 639 struct warn_args args; 640 641 pr_warn(CUT_HERE); 642 643 if (!fmt) { 644 __warn(file, line, __builtin_return_address(0), taint, 645 NULL, NULL); 646 return; 647 } 648 649 args.fmt = fmt; 650 va_start(args.args, fmt); 651 __warn(file, line, __builtin_return_address(0), taint, NULL, &args); 652 va_end(args.args); 653 } 654 EXPORT_SYMBOL(warn_slowpath_fmt); 655 #else 656 void __warn_printk(const char *fmt, ...) 657 { 658 va_list args; 659 660 pr_warn(CUT_HERE); 661 662 va_start(args, fmt); 663 vprintk(fmt, args); 664 va_end(args); 665 } 666 EXPORT_SYMBOL(__warn_printk); 667 #endif 668 669 #ifdef CONFIG_BUG 670 671 /* Support resetting WARN*_ONCE state */ 672 673 static int clear_warn_once_set(void *data, u64 val) 674 { 675 generic_bug_clear_once(); 676 memset(__start_once, 0, __end_once - __start_once); 677 return 0; 678 } 679 680 DEFINE_DEBUGFS_ATTRIBUTE(clear_warn_once_fops, NULL, clear_warn_once_set, 681 "%lld\n"); 682 683 static __init int register_warn_debugfs(void) 684 { 685 /* Don't care about failure */ 686 debugfs_create_file_unsafe("clear_warn_once", 0200, NULL, NULL, 687 &clear_warn_once_fops); 688 return 0; 689 } 690 691 device_initcall(register_warn_debugfs); 692 #endif 693 694 #ifdef CONFIG_STACKPROTECTOR 695 696 /* 697 * Called when gcc's -fstack-protector feature is used, and 698 * gcc detects corruption of the on-stack canary value 699 */ 700 __visible noinstr void __stack_chk_fail(void) 701 { 702 instrumentation_begin(); 703 panic("stack-protector: Kernel stack is corrupted in: %pB", 704 __builtin_return_address(0)); 705 instrumentation_end(); 706 } 707 EXPORT_SYMBOL(__stack_chk_fail); 708 709 #endif 710 711 core_param(panic, panic_timeout, int, 0644); 712 core_param(panic_print, panic_print, ulong, 0644); 713 core_param(pause_on_oops, pause_on_oops, int, 0644); 714 core_param(panic_on_warn, panic_on_warn, int, 0644); 715 core_param(crash_kexec_post_notifiers, crash_kexec_post_notifiers, bool, 0644); 716 717 static int __init oops_setup(char *s) 718 { 719 if (!s) 720 return -EINVAL; 721 if (!strcmp(s, "panic")) 722 panic_on_oops = 1; 723 return 0; 724 } 725 early_param("oops", oops_setup); 726 727 static int __init panic_on_taint_setup(char *s) 728 { 729 char *taint_str; 730 731 if (!s) 732 return -EINVAL; 733 734 taint_str = strsep(&s, ","); 735 if (kstrtoul(taint_str, 16, &panic_on_taint)) 736 return -EINVAL; 737 738 /* make sure panic_on_taint doesn't hold out-of-range TAINT flags */ 739 panic_on_taint &= TAINT_FLAGS_MAX; 740 741 if (!panic_on_taint) 742 return -EINVAL; 743 744 if (s && !strcmp(s, "nousertaint")) 745 panic_on_taint_nousertaint = true; 746 747 pr_info("panic_on_taint: bitmask=0x%lx nousertaint_mode=%sabled\n", 748 panic_on_taint, panic_on_taint_nousertaint ? "en" : "dis"); 749 750 return 0; 751 } 752 early_param("panic_on_taint", panic_on_taint_setup); 753