xref: /linux/kernel/panic.c (revision 87c9c16317882dd6dbbc07e349bc3223e14f3244)
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 
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  */
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  */
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  */
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  */
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 
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  */
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  */
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 
422 int test_taint(unsigned flag)
423 {
424 	return test_bit(flag, &tainted_mask);
425 }
426 EXPORT_SYMBOL(test_taint);
427 
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  */
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 
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  */
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  */
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  */
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 
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 
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  */
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 
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
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
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 
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 
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  */
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 
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 
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