aboutsummaryrefslogtreecommitdiff
path: root/kernel/panic.c
blob: b69ee9e76cb2ae0c561ffec54a83e5ee162d1082 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
// SPDX-License-Identifier: GPL-2.0-only
/*
 *  linux/kernel/panic.c
 *
 *  Copyright (C) 1991, 1992  Linus Torvalds
 */

/*
 * This function is used through-out the kernel (including mm and fs)
 * to indicate a major problem.
 */
#include <linux/debug_locks.h>
#include <linux/sched/debug.h>
#include <linux/interrupt.h>
#include <linux/kgdb.h>
#include <linux/kmsg_dump.h>
#include <linux/kallsyms.h>
#include <linux/notifier.h>
#include <linux/vt_kern.h>
#include <linux/module.h>
#include <linux/random.h>
#include <linux/ftrace.h>
#include <linux/reboot.h>
#include <linux/delay.h>
#include <linux/kexec.h>
#include <linux/sched.h>
#include <linux/sysrq.h>
#include <linux/init.h>
#include <linux/nmi.h>
#include <linux/console.h>
#include <linux/bug.h>
#include <linux/ratelimit.h>
#include <linux/debugfs.h>
#include <asm/sections.h>

#define PANIC_TIMER_STEP 100
#define PANIC_BLINK_SPD 18

int panic_on_oops = CONFIG_PANIC_ON_OOPS_VALUE;
static unsigned long tainted_mask =
	IS_ENABLED(CONFIG_GCC_PLUGIN_RANDSTRUCT) ? (1 << TAINT_RANDSTRUCT) : 0;
static int pause_on_oops;
static int pause_on_oops_flag;
static DEFINE_SPINLOCK(pause_on_oops_lock);
bool crash_kexec_post_notifiers;
int panic_on_warn __read_mostly;

int panic_timeout = CONFIG_PANIC_TIMEOUT;
EXPORT_SYMBOL_GPL(panic_timeout);

#define PANIC_PRINT_TASK_INFO		0x00000001
#define PANIC_PRINT_MEM_INFO		0x00000002
#define PANIC_PRINT_TIMER_INFO		0x00000004
#define PANIC_PRINT_LOCK_INFO		0x00000008
#define PANIC_PRINT_FTRACE_INFO		0x00000010
#define PANIC_PRINT_ALL_PRINTK_MSG	0x00000020
unsigned long panic_print;

ATOMIC_NOTIFIER_HEAD(panic_notifier_list);

EXPORT_SYMBOL(panic_notifier_list);

static long no_blink(int state)
{
	return 0;
}

/* Returns how long it waited in ms */
long (*panic_blink)(int state);
EXPORT_SYMBOL(panic_blink);

/*
 * Stop ourself in panic -- architecture code may override this
 */
void __weak panic_smp_self_stop(void)
{
	while (1)
		cpu_relax();
}

/*
 * Stop ourselves in NMI context if another CPU has already panicked. Arch code
 * may override this to prepare for crash dumping, e.g. save regs info.
 */
void __weak nmi_panic_self_stop(struct pt_regs *regs)
{
	panic_smp_self_stop();
}

/*
 * Stop other CPUs in panic.  Architecture dependent code may override this
 * with more suitable version.  For example, if the architecture supports
 * crash dump, it should save registers of each stopped CPU and disable
 * per-CPU features such as virtualization extensions.
 */
void __weak crash_smp_send_stop(void)
{
	static int cpus_stopped;

	/*
	 * This function can be called twice in panic path, but obviously
	 * we execute this only once.
	 */
	if (cpus_stopped)
		return;

	/*
	 * Note smp_send_stop is the usual smp shutdown function, which
	 * unfortunately means it may not be hardened to work in a panic
	 * situation.
	 */
	smp_send_stop();
	cpus_stopped = 1;
}

atomic_t panic_cpu = ATOMIC_INIT(PANIC_CPU_INVALID);

/*
 * A variant of panic() called from NMI context. We return if we've already
 * panicked on this CPU. If another CPU already panicked, loop in
 * nmi_panic_self_stop() which can provide architecture dependent code such
 * as saving register state for crash dump.
 */
void nmi_panic(struct pt_regs *regs, const char *msg)
{
	int old_cpu, cpu;

	cpu = raw_smp_processor_id();
	old_cpu = atomic_cmpxchg(&panic_cpu, PANIC_CPU_INVALID, cpu);

	if (old_cpu == PANIC_CPU_INVALID)
		panic("%s", msg);
	else if (old_cpu != cpu)
		nmi_panic_self_stop(regs);
}
EXPORT_SYMBOL(nmi_panic);

static void panic_print_sys_info(void)
{
	if (panic_print & PANIC_PRINT_ALL_PRINTK_MSG)
		console_flush_on_panic(CONSOLE_REPLAY_ALL);

	if (panic_print & PANIC_PRINT_TASK_INFO)
		show_state();

	if (panic_print & PANIC_PRINT_MEM_INFO)
		show_mem(0, NULL);

	if (panic_print & PANIC_PRINT_TIMER_INFO)
		sysrq_timer_list_show();

	if (panic_print & PANIC_PRINT_LOCK_INFO)
		debug_show_all_locks();

	if (panic_print & PANIC_PRINT_FTRACE_INFO)
		ftrace_dump(DUMP_ALL);
}

/**
 *	panic - halt the system
 *	@fmt: The text string to print
 *
 *	Display a message, then perform cleanups.
 *
 *	This function never returns.
 */
void panic(const char *fmt, ...)
{
	static char buf[1024];
	va_list args;
	long i, i_next = 0, len;
	int state = 0;
	int old_cpu, this_cpu;
	bool _crash_kexec_post_notifiers = crash_kexec_post_notifiers;

	/*
	 * Disable local interrupts. This will prevent panic_smp_self_stop
	 * from deadlocking the first cpu that invokes the panic, since
	 * there is nothing to prevent an interrupt handler (that runs
	 * after setting panic_cpu) from invoking panic() again.
	 */
	local_irq_disable();
	preempt_disable_notrace();

	/*
	 * It's possible to come here directly from a panic-assertion and
	 * not have preempt disabled. Some functions called from here want
	 * preempt to be disabled. No point enabling it later though...
	 *
	 * Only one CPU is allowed to execute the panic code from here. For
	 * multiple parallel invocations of panic, all other CPUs either
	 * stop themself or will wait until they are stopped by the 1st CPU
	 * with smp_send_stop().
	 *
	 * `old_cpu == PANIC_CPU_INVALID' means this is the 1st CPU which
	 * comes here, so go ahead.
	 * `old_cpu == this_cpu' means we came from nmi_panic() which sets
	 * panic_cpu to this CPU.  In this case, this is also the 1st CPU.
	 */
	this_cpu = raw_smp_processor_id();
	old_cpu  = atomic_cmpxchg(&panic_cpu, PANIC_CPU_INVALID, this_cpu);

	if (old_cpu != PANIC_CPU_INVALID && old_cpu != this_cpu)
		panic_smp_self_stop();

	console_verbose();
	bust_spinlocks(1);
	va_start(args, fmt);
	len = vscnprintf(buf, sizeof(buf), fmt, args);
	va_end(args);

	if (len && buf[len - 1] == '\n')
		buf[len - 1] = '\0';

	pr_emerg("Kernel panic - not syncing: %s\n", buf);
#ifdef CONFIG_DEBUG_BUGVERBOSE
	/*
	 * Avoid nested stack-dumping if a panic occurs during oops processing
	 */
	if (!test_taint(TAINT_DIE) && oops_in_progress <= 1)
		dump_stack();
#endif

	/*
	 * If kgdb is enabled, give it a chance to run before we stop all
	 * the other CPUs or else we won't be able to debug processes left
	 * running on them.
	 */
	kgdb_panic(buf);

	/*
	 * If we have crashed and we have a crash kernel loaded let it handle
	 * everything else.
	 * If we want to run this after calling panic_notifiers, pass
	 * the "crash_kexec_post_notifiers" option to the kernel.
	 *
	 * Bypass the panic_cpu check and call __crash_kexec directly.
	 */
	if (!_crash_kexec_post_notifiers) {
		printk_safe_flush_on_panic();
		__crash_kexec(NULL);

		/*
		 * Note smp_send_stop is the usual smp shutdown function, which
		 * unfortunately means it may not be hardened to work in a
		 * panic situation.
		 */
		smp_send_stop();
	} else {
		/*
		 * If we want to do crash dump after notifier calls and
		 * kmsg_dump, we will need architecture dependent extra
		 * works in addition to stopping other CPUs.
		 */
		crash_smp_send_stop();
	}

	/*
	 * Run any panic handlers, including those that might need to
	 * add information to the kmsg dump output.
	 */
	atomic_notifier_call_chain(&panic_notifier_list, 0, buf);

	/* Call flush even twice. It tries harder with a single online CPU */
	printk_safe_flush_on_panic();
	kmsg_dump(KMSG_DUMP_PANIC);

	/*
	 * If you doubt kdump always works fine in any situation,
	 * "crash_kexec_post_notifiers" offers you a chance to run
	 * panic_notifiers and dumping kmsg before kdump.
	 * Note: since some panic_notifiers can make crashed kernel
	 * more unstable, it can increase risks of the kdump failure too.
	 *
	 * Bypass the panic_cpu check and call __crash_kexec directly.
	 */
	if (_crash_kexec_post_notifiers)
		__crash_kexec(NULL);

#ifdef CONFIG_VT
	unblank_screen();
#endif
	console_unblank();

	/*
	 * We may have ended up stopping the CPU holding the lock (in
	 * smp_send_stop()) while still having some valuable data in the console
	 * buffer.  Try to acquire the lock then release it regardless of the
	 * result.  The release will also print the buffers out.  Locks debug
	 * should be disabled to avoid reporting bad unlock balance when
	 * panic() is not being callled from OOPS.
	 */
	debug_locks_off();
	console_flush_on_panic(CONSOLE_FLUSH_PENDING);

	panic_print_sys_info();

	if (!panic_blink)
		panic_blink = no_blink;

	if (panic_timeout > 0) {
		/*
		 * Delay timeout seconds before rebooting the machine.
		 * We can't use the "normal" timers since we just panicked.
		 */
		pr_emerg("Rebooting in %d seconds..\n", panic_timeout);

		for (i = 0; i < panic_timeout * 1000; i += PANIC_TIMER_STEP) {
			touch_nmi_watchdog();
			if (i >= i_next) {
				i += panic_blink(state ^= 1);
				i_next = i + 3600 / PANIC_BLINK_SPD;
			}
			mdelay(PANIC_TIMER_STEP);
		}
	}
	if (panic_timeout != 0) {
		/*
		 * This will not be a clean reboot, with everything
		 * shutting down.  But if there is a chance of
		 * rebooting the system it will be rebooted.
		 */
		if (panic_reboot_mode != REBOOT_UNDEFINED)
			reboot_mode = panic_reboot_mode;
		emergency_restart();
	}
#ifdef __sparc__
	{
		extern int stop_a_enabled;
		/* Make sure the user can actually press Stop-A (L1-A) */
		stop_a_enabled = 1;
		pr_emerg("Press Stop-A (L1-A) from sun keyboard or send break\n"
			 "twice on console to return to the boot prom\n");
	}
#endif
#if defined(CONFIG_S390)
	disabled_wait();
#endif
	pr_emerg("---[ end Kernel panic - not syncing: %s ]---\n", buf);

	/* Do not scroll important messages printed above */
	suppress_printk = 1;
	local_irq_enable();
	for (i = 0; ; i += PANIC_TIMER_STEP) {
		touch_softlockup_watchdog();
		if (i >= i_next) {
			i += panic_blink(state ^= 1);
			i_next = i + 3600 / PANIC_BLINK_SPD;
		}
		mdelay(PANIC_TIMER_STEP);
	}
}

EXPORT_SYMBOL(panic);

/*
 * TAINT_FORCED_RMMOD could be a per-module flag but the module
 * is being removed anyway.
 */
const struct taint_flag taint_flags[TAINT_FLAGS_COUNT] = {
	[ TAINT_PROPRIETARY_MODULE ]	= { 'P', 'G', true },
	[ TAINT_FORCED_MODULE ]		= { 'F', ' ', true },
	[ TAINT_CPU_OUT_OF_SPEC ]	= { 'S', ' ', false },
	[ TAINT_FORCED_RMMOD ]		= { 'R', ' ', false },
	[ TAINT_MACHINE_CHECK ]		= { 'M', ' ', false },
	[ TAINT_BAD_PAGE ]		= { 'B', ' ', false },
	[ TAINT_USER ]			= { 'U', ' ', false },
	[ TAINT_DIE ]			= { 'D', ' ', false },
	[ TAINT_OVERRIDDEN_ACPI_TABLE ]	= { 'A', ' ', false },
	[ TAINT_WARN ]			= { 'W', ' ', false },
	[ TAINT_CRAP ]			= { 'C', ' ', true },
	[ TAINT_FIRMWARE_WORKAROUND ]	= { 'I', ' ', false },
	[ TAINT_OOT_MODULE ]		= { 'O', ' ', true },
	[ TAINT_UNSIGNED_MODULE ]	= { 'E', ' ', true },
	[ TAINT_SOFTLOCKUP ]		= { 'L', ' ', false },
	[ TAINT_LIVEPATCH ]		= { 'K', ' ', true },
	[ TAINT_AUX ]			= { 'X', ' ', true },
	[ TAINT_RANDSTRUCT ]		= { 'T', ' ', true },
};

/**
 * print_tainted - return a string to represent the kernel taint state.
 *
 * For individual taint flag meanings, see Documentation/admin-guide/sysctl/kernel.rst
 *
 * The string is overwritten by the next call to print_tainted(),
 * but is always NULL terminated.
 */
const char *print_tainted(void)
{
	static char buf[TAINT_FLAGS_COUNT + sizeof("Tainted: ")];

	BUILD_BUG_ON(ARRAY_SIZE(taint_flags) != TAINT_FLAGS_COUNT);

	if (tainted_mask) {
		char *s;
		int i;

		s = buf + sprintf(buf, "Tainted: ");
		for (i = 0; i < TAINT_FLAGS_COUNT; i++) {
			const struct taint_flag *t = &taint_flags[i];
			*s++ = test_bit(i, &tainted_mask) ?
					t->c_true : t->c_false;
		}
		*s = 0;
	} else
		snprintf(buf, sizeof(buf), "Not tainted");

	return buf;
}

int test_taint(unsigned flag)
{
	return test_bit(flag, &tainted_mask);
}
EXPORT_SYMBOL(test_taint);

unsigned long get_taint(void)
{
	return tainted_mask;
}

/**
 * add_taint: add a taint flag if not already set.
 * @flag: one of the TAINT_* constants.
 * @lockdep_ok: whether lock debugging is still OK.
 *
 * If something bad has gone wrong, you'll want @lockdebug_ok = false, but for
 * some notewortht-but-not-corrupting cases, it can be set to true.
 */
void add_taint(unsigned flag, enum lockdep_ok lockdep_ok)
{
	if (lockdep_ok == LOCKDEP_NOW_UNRELIABLE && __debug_locks_off())
		pr_warn("Disabling lock debugging due to kernel taint\n");

	set_bit(flag, &tainted_mask);
}
EXPORT_SYMBOL(add_taint);

static void spin_msec(int msecs)
{
	int i;

	for (i = 0; i < msecs; i++) {
		touch_nmi_watchdog();
		mdelay(1);
	}
}

/*
 * It just happens that oops_enter() and oops_exit() are identically
 * implemented...
 */
static void do_oops_enter_exit(void)
{
	unsigned long flags;
	static int spin_counter;

	if (!pause_on_oops)
		return;

	spin_lock_irqsave(&pause_on_oops_lock, flags);
	if (pause_on_oops_flag == 0) {
		/* This CPU may now print the oops message */
		pause_on_oops_flag = 1;
	} else {
		/* We need to stall this CPU */
		if (!spin_counter) {
			/* This CPU gets to do the counting */
			spin_counter = pause_on_oops;
			do {
				spin_unlock(&pause_on_oops_lock);
				spin_msec(MSEC_PER_SEC);
				spin_lock(&pause_on_oops_lock);
			} while (--spin_counter);
			pause_on_oops_flag = 0;
		} else {
			/* This CPU waits for a different one */
			while (spin_counter) {
				spin_unlock(&pause_on_oops_lock);
				spin_msec(1);
				spin_lock(&pause_on_oops_lock);
			}
		}
	}
	spin_unlock_irqrestore(&pause_on_oops_lock, flags);
}

/*
 * Return true if the calling CPU is allowed to print oops-related info.
 * This is a bit racy..
 */
int oops_may_print(void)
{
	return pause_on_oops_flag == 0;
}

/*
 * Called when the architecture enters its oops handler, before it prints
 * anything.  If this is the first CPU to oops, and it's oopsing the first
 * time then let it proceed.
 *
 * This is all enabled by the pause_on_oops kernel boot option.  We do all
 * this to ensure that oopses don't scroll off the screen.  It has the
 * side-effect of preventing later-oopsing CPUs from mucking up the display,
 * too.
 *
 * It turns out that the CPU which is allowed to print ends up pausing for
 * the right duration, whereas all the other CPUs pause for twice as long:
 * once in oops_enter(), once in oops_exit().
 */
void oops_enter(void)
{
	tracing_off();
	/* can't trust the integrity of the kernel anymore: */
	debug_locks_off();
	do_oops_enter_exit();
}

/*
 * 64-bit random ID for oopses:
 */
static u64 oops_id;

static int init_oops_id(void)
{
	if (!oops_id)
		get_random_bytes(&oops_id, sizeof(oops_id));
	else
		oops_id++;

	return 0;
}
late_initcall(init_oops_id);

void print_oops_end_marker(void)
{
	init_oops_id();
	pr_warn("---[ end trace %016llx ]---\n", (unsigned long long)oops_id);
}

/*
 * Called when the architecture exits its oops handler, after printing
 * everything.
 */
void oops_exit(void)
{
	do_oops_enter_exit();
	print_oops_end_marker();
	kmsg_dump(KMSG_DUMP_OOPS);
}

struct warn_args {
	const char *fmt;
	va_list args;
};

void __warn(const char *file, int line, void *caller, unsigned taint,
	    struct pt_regs *regs, struct warn_args *args)
{
	disable_trace_on_warning();

	if (file)
		pr_warn("WARNING: CPU: %d PID: %d at %s:%d %pS\n",
			raw_smp_processor_id(), current->pid, file, line,
			caller);
	else
		pr_warn("WARNING: CPU: %d PID: %d at %pS\n",
			raw_smp_processor_id(), current->pid, caller);

	if (args)
		vprintk(args->fmt, args->args);

	if (panic_on_warn) {
		/*
		 * This thread may hit another WARN() in the panic path.
		 * Resetting this prevents additional WARN() from panicking the
		 * system on this thread.  Other threads are blocked by the
		 * panic_mutex in panic().
		 */
		panic_on_warn = 0;
		panic("panic_on_warn set ...\n");
	}

	print_modules();

	if (regs)
		show_regs(regs);
	else
		dump_stack();

	print_irqtrace_events(current);

	print_oops_end_marker();

	/* Just a warning, don't kill lockdep. */
	add_taint(taint, LOCKDEP_STILL_OK);
}

#ifndef __WARN_FLAGS
void warn_slowpath_fmt(const char *file, int line, unsigned taint,
		       const char *fmt, ...)
{
	struct warn_args args;

	pr_warn(CUT_HERE);

	if (!fmt) {
		__warn(file, line, __builtin_return_address(0), taint,
		       NULL, NULL);
		return;
	}

	args.fmt = fmt;
	va_start(args.args, fmt);
	__warn(file, line, __builtin_return_address(0), taint, NULL, &args);
	va_end(args.args);
}
EXPORT_SYMBOL(warn_slowpath_fmt);
#else
void __warn_printk(const char *fmt, ...)
{
	va_list args;

	pr_warn(CUT_HERE);

	va_start(args, fmt);
	vprintk(fmt, args);
	va_end(args);
}
EXPORT_SYMBOL(__warn_printk);
#endif

#ifdef CONFIG_BUG

/* Support resetting WARN*_ONCE state */

static int clear_warn_once_set(void *data, u64 val)
{
	generic_bug_clear_once();
	memset(__start_once, 0, __end_once - __start_once);
	return 0;
}

DEFINE_DEBUGFS_ATTRIBUTE(clear_warn_once_fops, NULL, clear_warn_once_set,
			 "%lld\n");

static __init int register_warn_debugfs(void)
{
	/* Don't care about failure */
	debugfs_create_file_unsafe("clear_warn_once", 0200, NULL, NULL,
				   &clear_warn_once_fops);
	return 0;
}

device_initcall(register_warn_debugfs);
#endif

#ifdef CONFIG_STACKPROTECTOR

/*
 * Called when gcc's -fstack-protector feature is used, and
 * gcc detects corruption of the on-stack canary value
 */
__visible void __stack_chk_fail(void)
{
	panic("stack-protector: Kernel stack is corrupted in: %pB",
		__builtin_return_address(0));
}
EXPORT_SYMBOL(__stack_chk_fail);

#endif

core_param(panic, panic_timeout, int, 0644);
core_param(panic_print, panic_print, ulong, 0644);
core_param(pause_on_oops, pause_on_oops, int, 0644);
core_param(panic_on_warn, panic_on_warn, int, 0644);
core_param(crash_kexec_post_notifiers, crash_kexec_post_notifiers, bool, 0644);

static int __init oops_setup(char *s)
{
	if (!s)
		return -EINVAL;
	if (!strcmp(s, "panic"))
		panic_on_oops = 1;
	return 0;
}
early_param("oops", oops_setup);