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