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 */
46static unsigned int __read_mostly sysctl_oops_all_cpu_backtrace;
47#else
48#define sysctl_oops_all_cpu_backtrace 0
49#endif /* CONFIG_SMP */
50
51int panic_on_oops = CONFIG_PANIC_ON_OOPS_VALUE;
52static unsigned long tainted_mask =
53	IS_ENABLED(CONFIG_RANDSTRUCT) ? (1 << TAINT_RANDSTRUCT) : 0;
54static int pause_on_oops;
55static int pause_on_oops_flag;
56static DEFINE_SPINLOCK(pause_on_oops_lock);
57bool crash_kexec_post_notifiers;
58int panic_on_warn __read_mostly;
59unsigned long panic_on_taint;
60bool panic_on_taint_nousertaint = false;
61
62int panic_timeout = CONFIG_PANIC_TIMEOUT;
63EXPORT_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
72unsigned long panic_print;
73
74ATOMIC_NOTIFIER_HEAD(panic_notifier_list);
75
76EXPORT_SYMBOL(panic_notifier_list);
77
78#if defined(CONFIG_SMP) && defined(CONFIG_SYSCTL)
79static 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
92static __init int kernel_panic_sysctls_init(void)
93{
94	register_sysctl_init("kernel", kern_panic_table);
95	return 0;
96}
97late_initcall(kernel_panic_sysctls_init);
98#endif
99
100static long no_blink(int state)
101{
102	return 0;
103}
104
105/* Returns how long it waited in ms */
106long (*panic_blink)(int state);
107EXPORT_SYMBOL(panic_blink);
108
109/*
110 * Stop ourself in panic -- architecture code may override this
111 */
112void __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 */
122void __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 */
133void __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
153atomic_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 */
161void 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}
173EXPORT_SYMBOL(nmi_panic);
174
175static 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 */
210void 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#ifdef CONFIG_VT
333	unblank_screen();
334#endif
335	console_unblank();
336
337	/*
338	 * We may have ended up stopping the CPU holding the lock (in
339	 * smp_send_stop()) while still having some valuable data in the console
340	 * buffer.  Try to acquire the lock then release it regardless of the
341	 * result.  The release will also print the buffers out.  Locks debug
342	 * should be disabled to avoid reporting bad unlock balance when
343	 * panic() is not being callled from OOPS.
344	 */
345	debug_locks_off();
346	console_flush_on_panic(CONSOLE_FLUSH_PENDING);
347
348	panic_print_sys_info(true);
349
350	if (!panic_blink)
351		panic_blink = no_blink;
352
353	if (panic_timeout > 0) {
354		/*
355		 * Delay timeout seconds before rebooting the machine.
356		 * We can't use the "normal" timers since we just panicked.
357		 */
358		pr_emerg("Rebooting in %d seconds..\n", panic_timeout);
359
360		for (i = 0; i < panic_timeout * 1000; i += PANIC_TIMER_STEP) {
361			touch_nmi_watchdog();
362			if (i >= i_next) {
363				i += panic_blink(state ^= 1);
364				i_next = i + 3600 / PANIC_BLINK_SPD;
365			}
366			mdelay(PANIC_TIMER_STEP);
367		}
368	}
369	if (panic_timeout != 0) {
370		/*
371		 * This will not be a clean reboot, with everything
372		 * shutting down.  But if there is a chance of
373		 * rebooting the system it will be rebooted.
374		 */
375		if (panic_reboot_mode != REBOOT_UNDEFINED)
376			reboot_mode = panic_reboot_mode;
377		emergency_restart();
378	}
379#ifdef __sparc__
380	{
381		extern int stop_a_enabled;
382		/* Make sure the user can actually press Stop-A (L1-A) */
383		stop_a_enabled = 1;
384		pr_emerg("Press Stop-A (L1-A) from sun keyboard or send break\n"
385			 "twice on console to return to the boot prom\n");
386	}
387#endif
388#if defined(CONFIG_S390)
389	disabled_wait();
390#endif
391	pr_emerg("---[ end Kernel panic - not syncing: %s ]---\n", buf);
392
393	/* Do not scroll important messages printed above */
394	suppress_printk = 1;
395	local_irq_enable();
396	for (i = 0; ; i += PANIC_TIMER_STEP) {
397		touch_softlockup_watchdog();
398		if (i >= i_next) {
399			i += panic_blink(state ^= 1);
400			i_next = i + 3600 / PANIC_BLINK_SPD;
401		}
402		mdelay(PANIC_TIMER_STEP);
403	}
404}
405
406EXPORT_SYMBOL(panic);
407
408/*
409 * TAINT_FORCED_RMMOD could be a per-module flag but the module
410 * is being removed anyway.
411 */
412const struct taint_flag taint_flags[TAINT_FLAGS_COUNT] = {
413	[ TAINT_PROPRIETARY_MODULE ]	= { 'P', 'G', true },
414	[ TAINT_FORCED_MODULE ]		= { 'F', ' ', true },
415	[ TAINT_CPU_OUT_OF_SPEC ]	= { 'S', ' ', false },
416	[ TAINT_FORCED_RMMOD ]		= { 'R', ' ', false },
417	[ TAINT_MACHINE_CHECK ]		= { 'M', ' ', false },
418	[ TAINT_BAD_PAGE ]		= { 'B', ' ', false },
419	[ TAINT_USER ]			= { 'U', ' ', false },
420	[ TAINT_DIE ]			= { 'D', ' ', false },
421	[ TAINT_OVERRIDDEN_ACPI_TABLE ]	= { 'A', ' ', false },
422	[ TAINT_WARN ]			= { 'W', ' ', false },
423	[ TAINT_CRAP ]			= { 'C', ' ', true },
424	[ TAINT_FIRMWARE_WORKAROUND ]	= { 'I', ' ', false },
425	[ TAINT_OOT_MODULE ]		= { 'O', ' ', true },
426	[ TAINT_UNSIGNED_MODULE ]	= { 'E', ' ', true },
427	[ TAINT_SOFTLOCKUP ]		= { 'L', ' ', false },
428	[ TAINT_LIVEPATCH ]		= { 'K', ' ', true },
429	[ TAINT_AUX ]			= { 'X', ' ', true },
430	[ TAINT_RANDSTRUCT ]		= { 'T', ' ', true },
431	[ TAINT_TEST ]			= { 'N', ' ', true },
432};
433
434/**
435 * print_tainted - return a string to represent the kernel taint state.
436 *
437 * For individual taint flag meanings, see Documentation/admin-guide/sysctl/kernel.rst
438 *
439 * The string is overwritten by the next call to print_tainted(),
440 * but is always NULL terminated.
441 */
442const char *print_tainted(void)
443{
444	static char buf[TAINT_FLAGS_COUNT + sizeof("Tainted: ")];
445
446	BUILD_BUG_ON(ARRAY_SIZE(taint_flags) != TAINT_FLAGS_COUNT);
447
448	if (tainted_mask) {
449		char *s;
450		int i;
451
452		s = buf + sprintf(buf, "Tainted: ");
453		for (i = 0; i < TAINT_FLAGS_COUNT; i++) {
454			const struct taint_flag *t = &taint_flags[i];
455			*s++ = test_bit(i, &tainted_mask) ?
456					t->c_true : t->c_false;
457		}
458		*s = 0;
459	} else
460		snprintf(buf, sizeof(buf), "Not tainted");
461
462	return buf;
463}
464
465int test_taint(unsigned flag)
466{
467	return test_bit(flag, &tainted_mask);
468}
469EXPORT_SYMBOL(test_taint);
470
471unsigned long get_taint(void)
472{
473	return tainted_mask;
474}
475
476/**
477 * add_taint: add a taint flag if not already set.
478 * @flag: one of the TAINT_* constants.
479 * @lockdep_ok: whether lock debugging is still OK.
480 *
481 * If something bad has gone wrong, you'll want @lockdebug_ok = false, but for
482 * some notewortht-but-not-corrupting cases, it can be set to true.
483 */
484void add_taint(unsigned flag, enum lockdep_ok lockdep_ok)
485{
486	if (lockdep_ok == LOCKDEP_NOW_UNRELIABLE && __debug_locks_off())
487		pr_warn("Disabling lock debugging due to kernel taint\n");
488
489	set_bit(flag, &tainted_mask);
490
491	if (tainted_mask & panic_on_taint) {
492		panic_on_taint = 0;
493		panic("panic_on_taint set ...");
494	}
495}
496EXPORT_SYMBOL(add_taint);
497
498static void spin_msec(int msecs)
499{
500	int i;
501
502	for (i = 0; i < msecs; i++) {
503		touch_nmi_watchdog();
504		mdelay(1);
505	}
506}
507
508/*
509 * It just happens that oops_enter() and oops_exit() are identically
510 * implemented...
511 */
512static void do_oops_enter_exit(void)
513{
514	unsigned long flags;
515	static int spin_counter;
516
517	if (!pause_on_oops)
518		return;
519
520	spin_lock_irqsave(&pause_on_oops_lock, flags);
521	if (pause_on_oops_flag == 0) {
522		/* This CPU may now print the oops message */
523		pause_on_oops_flag = 1;
524	} else {
525		/* We need to stall this CPU */
526		if (!spin_counter) {
527			/* This CPU gets to do the counting */
528			spin_counter = pause_on_oops;
529			do {
530				spin_unlock(&pause_on_oops_lock);
531				spin_msec(MSEC_PER_SEC);
532				spin_lock(&pause_on_oops_lock);
533			} while (--spin_counter);
534			pause_on_oops_flag = 0;
535		} else {
536			/* This CPU waits for a different one */
537			while (spin_counter) {
538				spin_unlock(&pause_on_oops_lock);
539				spin_msec(1);
540				spin_lock(&pause_on_oops_lock);
541			}
542		}
543	}
544	spin_unlock_irqrestore(&pause_on_oops_lock, flags);
545}
546
547/*
548 * Return true if the calling CPU is allowed to print oops-related info.
549 * This is a bit racy..
550 */
551bool oops_may_print(void)
552{
553	return pause_on_oops_flag == 0;
554}
555
556/*
557 * Called when the architecture enters its oops handler, before it prints
558 * anything.  If this is the first CPU to oops, and it's oopsing the first
559 * time then let it proceed.
560 *
561 * This is all enabled by the pause_on_oops kernel boot option.  We do all
562 * this to ensure that oopses don't scroll off the screen.  It has the
563 * side-effect of preventing later-oopsing CPUs from mucking up the display,
564 * too.
565 *
566 * It turns out that the CPU which is allowed to print ends up pausing for
567 * the right duration, whereas all the other CPUs pause for twice as long:
568 * once in oops_enter(), once in oops_exit().
569 */
570void oops_enter(void)
571{
572	tracing_off();
573	/* can't trust the integrity of the kernel anymore: */
574	debug_locks_off();
575	do_oops_enter_exit();
576
577	if (sysctl_oops_all_cpu_backtrace)
578		trigger_all_cpu_backtrace();
579}
580
581static void print_oops_end_marker(void)
582{
583	pr_warn("---[ end trace %016llx ]---\n", 0ULL);
584}
585
586/*
587 * Called when the architecture exits its oops handler, after printing
588 * everything.
589 */
590void oops_exit(void)
591{
592	do_oops_enter_exit();
593	print_oops_end_marker();
594	kmsg_dump(KMSG_DUMP_OOPS);
595}
596
597struct warn_args {
598	const char *fmt;
599	va_list args;
600};
601
602void __warn(const char *file, int line, void *caller, unsigned taint,
603	    struct pt_regs *regs, struct warn_args *args)
604{
605	disable_trace_on_warning();
606
607	if (file)
608		pr_warn("WARNING: CPU: %d PID: %d at %s:%d %pS\n",
609			raw_smp_processor_id(), current->pid, file, line,
610			caller);
611	else
612		pr_warn("WARNING: CPU: %d PID: %d at %pS\n",
613			raw_smp_processor_id(), current->pid, caller);
614
615	if (args)
616		vprintk(args->fmt, args->args);
617
618	print_modules();
619
620	if (regs)
621		show_regs(regs);
622
623	if (panic_on_warn)
624		panic("panic_on_warn set ...\n");
625
626	if (!regs)
627		dump_stack();
628
629	print_irqtrace_events(current);
630
631	print_oops_end_marker();
632	trace_error_report_end(ERROR_DETECTOR_WARN, (unsigned long)caller);
633
634	/* Just a warning, don't kill lockdep. */
635	add_taint(taint, LOCKDEP_STILL_OK);
636}
637
638#ifndef __WARN_FLAGS
639void warn_slowpath_fmt(const char *file, int line, unsigned taint,
640		       const char *fmt, ...)
641{
642	struct warn_args args;
643
644	pr_warn(CUT_HERE);
645
646	if (!fmt) {
647		__warn(file, line, __builtin_return_address(0), taint,
648		       NULL, NULL);
649		return;
650	}
651
652	args.fmt = fmt;
653	va_start(args.args, fmt);
654	__warn(file, line, __builtin_return_address(0), taint, NULL, &args);
655	va_end(args.args);
656}
657EXPORT_SYMBOL(warn_slowpath_fmt);
658#else
659void __warn_printk(const char *fmt, ...)
660{
661	va_list args;
662
663	pr_warn(CUT_HERE);
664
665	va_start(args, fmt);
666	vprintk(fmt, args);
667	va_end(args);
668}
669EXPORT_SYMBOL(__warn_printk);
670#endif
671
672#ifdef CONFIG_BUG
673
674/* Support resetting WARN*_ONCE state */
675
676static int clear_warn_once_set(void *data, u64 val)
677{
678	generic_bug_clear_once();
679	memset(__start_once, 0, __end_once - __start_once);
680	return 0;
681}
682
683DEFINE_DEBUGFS_ATTRIBUTE(clear_warn_once_fops, NULL, clear_warn_once_set,
684			 "%lld\n");
685
686static __init int register_warn_debugfs(void)
687{
688	/* Don't care about failure */
689	debugfs_create_file_unsafe("clear_warn_once", 0200, NULL, NULL,
690				   &clear_warn_once_fops);
691	return 0;
692}
693
694device_initcall(register_warn_debugfs);
695#endif
696
697#ifdef CONFIG_STACKPROTECTOR
698
699/*
700 * Called when gcc's -fstack-protector feature is used, and
701 * gcc detects corruption of the on-stack canary value
702 */
703__visible noinstr void __stack_chk_fail(void)
704{
705	instrumentation_begin();
706	panic("stack-protector: Kernel stack is corrupted in: %pB",
707		__builtin_return_address(0));
708	instrumentation_end();
709}
710EXPORT_SYMBOL(__stack_chk_fail);
711
712#endif
713
714core_param(panic, panic_timeout, int, 0644);
715core_param(panic_print, panic_print, ulong, 0644);
716core_param(pause_on_oops, pause_on_oops, int, 0644);
717core_param(panic_on_warn, panic_on_warn, int, 0644);
718core_param(crash_kexec_post_notifiers, crash_kexec_post_notifiers, bool, 0644);
719
720static int __init oops_setup(char *s)
721{
722	if (!s)
723		return -EINVAL;
724	if (!strcmp(s, "panic"))
725		panic_on_oops = 1;
726	return 0;
727}
728early_param("oops", oops_setup);
729
730static int __init panic_on_taint_setup(char *s)
731{
732	char *taint_str;
733
734	if (!s)
735		return -EINVAL;
736
737	taint_str = strsep(&s, ",");
738	if (kstrtoul(taint_str, 16, &panic_on_taint))
739		return -EINVAL;
740
741	/* make sure panic_on_taint doesn't hold out-of-range TAINT flags */
742	panic_on_taint &= TAINT_FLAGS_MAX;
743
744	if (!panic_on_taint)
745		return -EINVAL;
746
747	if (s && !strcmp(s, "nousertaint"))
748		panic_on_taint_nousertaint = true;
749
750	pr_info("panic_on_taint: bitmask=0x%lx nousertaint_mode=%sabled\n",
751		panic_on_taint, panic_on_taint_nousertaint ? "en" : "dis");
752
753	return 0;
754}
755early_param("panic_on_taint", panic_on_taint_setup);
756