kthread: rename probe_kthread_data() to kthread_probe_data()
[linux-2.6-block.git] / kernel / panic.c
CommitLineData
1da177e4
LT
1/*
2 * linux/kernel/panic.c
3 *
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 */
6
7/*
8 * This function is used through-out the kernel (including mm and fs)
9 * to indicate a major problem.
10 */
c95dbf27
IM
11#include <linux/debug_locks.h>
12#include <linux/interrupt.h>
456b565c 13#include <linux/kmsg_dump.h>
c95dbf27
IM
14#include <linux/kallsyms.h>
15#include <linux/notifier.h>
1da177e4 16#include <linux/module.h>
c95dbf27 17#include <linux/random.h>
de7edd31 18#include <linux/ftrace.h>
1da177e4 19#include <linux/reboot.h>
c95dbf27
IM
20#include <linux/delay.h>
21#include <linux/kexec.h>
22#include <linux/sched.h>
1da177e4 23#include <linux/sysrq.h>
c95dbf27 24#include <linux/init.h>
1da177e4 25#include <linux/nmi.h>
08d78658 26#include <linux/console.h>
2553b67a 27#include <linux/bug.h>
1da177e4 28
c7ff0d9c
TS
29#define PANIC_TIMER_STEP 100
30#define PANIC_BLINK_SPD 18
31
2a01bb38 32int panic_on_oops = CONFIG_PANIC_ON_OOPS_VALUE;
25ddbb18 33static unsigned long tainted_mask;
dd287796
AM
34static int pause_on_oops;
35static int pause_on_oops_flag;
36static DEFINE_SPINLOCK(pause_on_oops_lock);
5375b708 37bool crash_kexec_post_notifiers;
9e3961a0 38int panic_on_warn __read_mostly;
1da177e4 39
5800dc3c 40int panic_timeout = CONFIG_PANIC_TIMEOUT;
81e88fdc 41EXPORT_SYMBOL_GPL(panic_timeout);
1da177e4 42
e041c683 43ATOMIC_NOTIFIER_HEAD(panic_notifier_list);
1da177e4
LT
44
45EXPORT_SYMBOL(panic_notifier_list);
46
c7ff0d9c 47static long no_blink(int state)
8aeee85a 48{
c7ff0d9c 49 return 0;
8aeee85a
AB
50}
51
c7ff0d9c
TS
52/* Returns how long it waited in ms */
53long (*panic_blink)(int state);
54EXPORT_SYMBOL(panic_blink);
55
93e13a36
MH
56/*
57 * Stop ourself in panic -- architecture code may override this
58 */
59void __weak panic_smp_self_stop(void)
60{
61 while (1)
62 cpu_relax();
63}
64
58c5661f
HK
65/*
66 * Stop ourselves in NMI context if another CPU has already panicked. Arch code
67 * may override this to prepare for crash dumping, e.g. save regs info.
68 */
69void __weak nmi_panic_self_stop(struct pt_regs *regs)
70{
71 panic_smp_self_stop();
72}
73
0ee59413
HK
74/*
75 * Stop other CPUs in panic. Architecture dependent code may override this
76 * with more suitable version. For example, if the architecture supports
77 * crash dump, it should save registers of each stopped CPU and disable
78 * per-CPU features such as virtualization extensions.
79 */
80void __weak crash_smp_send_stop(void)
81{
82 static int cpus_stopped;
83
84 /*
85 * This function can be called twice in panic path, but obviously
86 * we execute this only once.
87 */
88 if (cpus_stopped)
89 return;
90
91 /*
92 * Note smp_send_stop is the usual smp shutdown function, which
93 * unfortunately means it may not be hardened to work in a panic
94 * situation.
95 */
96 smp_send_stop();
97 cpus_stopped = 1;
98}
99
1717f209
HK
100atomic_t panic_cpu = ATOMIC_INIT(PANIC_CPU_INVALID);
101
ebc41f20
HK
102/*
103 * A variant of panic() called from NMI context. We return if we've already
104 * panicked on this CPU. If another CPU already panicked, loop in
105 * nmi_panic_self_stop() which can provide architecture dependent code such
106 * as saving register state for crash dump.
107 */
108void nmi_panic(struct pt_regs *regs, const char *msg)
109{
110 int old_cpu, cpu;
111
112 cpu = raw_smp_processor_id();
113 old_cpu = atomic_cmpxchg(&panic_cpu, PANIC_CPU_INVALID, cpu);
114
115 if (old_cpu == PANIC_CPU_INVALID)
116 panic("%s", msg);
117 else if (old_cpu != cpu)
118 nmi_panic_self_stop(regs);
119}
120EXPORT_SYMBOL(nmi_panic);
121
1da177e4
LT
122/**
123 * panic - halt the system
124 * @fmt: The text string to print
125 *
126 * Display a message, then perform cleanups.
127 *
128 * This function never returns.
129 */
9402c95f 130void panic(const char *fmt, ...)
1da177e4 131{
1da177e4
LT
132 static char buf[1024];
133 va_list args;
c7ff0d9c
TS
134 long i, i_next = 0;
135 int state = 0;
1717f209 136 int old_cpu, this_cpu;
b26e27dd 137 bool _crash_kexec_post_notifiers = crash_kexec_post_notifiers;
1da177e4 138
190320c3
VM
139 /*
140 * Disable local interrupts. This will prevent panic_smp_self_stop
141 * from deadlocking the first cpu that invokes the panic, since
142 * there is nothing to prevent an interrupt handler (that runs
1717f209 143 * after setting panic_cpu) from invoking panic() again.
190320c3
VM
144 */
145 local_irq_disable();
146
dc009d92 147 /*
c95dbf27
IM
148 * It's possible to come here directly from a panic-assertion and
149 * not have preempt disabled. Some functions called from here want
dc009d92 150 * preempt to be disabled. No point enabling it later though...
93e13a36
MH
151 *
152 * Only one CPU is allowed to execute the panic code from here. For
153 * multiple parallel invocations of panic, all other CPUs either
154 * stop themself or will wait until they are stopped by the 1st CPU
155 * with smp_send_stop().
1717f209
HK
156 *
157 * `old_cpu == PANIC_CPU_INVALID' means this is the 1st CPU which
158 * comes here, so go ahead.
159 * `old_cpu == this_cpu' means we came from nmi_panic() which sets
160 * panic_cpu to this CPU. In this case, this is also the 1st CPU.
dc009d92 161 */
1717f209
HK
162 this_cpu = raw_smp_processor_id();
163 old_cpu = atomic_cmpxchg(&panic_cpu, PANIC_CPU_INVALID, this_cpu);
164
165 if (old_cpu != PANIC_CPU_INVALID && old_cpu != this_cpu)
93e13a36 166 panic_smp_self_stop();
dc009d92 167
5b530fc1 168 console_verbose();
1da177e4
LT
169 bust_spinlocks(1);
170 va_start(args, fmt);
171 vsnprintf(buf, sizeof(buf), fmt, args);
172 va_end(args);
d7c0847f 173 pr_emerg("Kernel panic - not syncing: %s\n", buf);
5cb27301 174#ifdef CONFIG_DEBUG_BUGVERBOSE
6e6f0a1f
AK
175 /*
176 * Avoid nested stack-dumping if a panic occurs during oops processing
177 */
026ee1f6 178 if (!test_taint(TAINT_DIE) && oops_in_progress <= 1)
6e6f0a1f 179 dump_stack();
5cb27301 180#endif
1da177e4 181
dc009d92
EB
182 /*
183 * If we have crashed and we have a crash kernel loaded let it handle
184 * everything else.
f06e5153
MH
185 * If we want to run this after calling panic_notifiers, pass
186 * the "crash_kexec_post_notifiers" option to the kernel.
7bbee5ca
HK
187 *
188 * Bypass the panic_cpu check and call __crash_kexec directly.
dc009d92 189 */
b26e27dd 190 if (!_crash_kexec_post_notifiers) {
cf9b1106 191 printk_nmi_flush_on_panic();
7bbee5ca 192 __crash_kexec(NULL);
dc009d92 193
0ee59413
HK
194 /*
195 * Note smp_send_stop is the usual smp shutdown function, which
196 * unfortunately means it may not be hardened to work in a
197 * panic situation.
198 */
199 smp_send_stop();
200 } else {
201 /*
202 * If we want to do crash dump after notifier calls and
203 * kmsg_dump, we will need architecture dependent extra
204 * works in addition to stopping other CPUs.
205 */
206 crash_smp_send_stop();
207 }
1da177e4 208
6723734c
KC
209 /*
210 * Run any panic handlers, including those that might need to
211 * add information to the kmsg dump output.
212 */
e041c683 213 atomic_notifier_call_chain(&panic_notifier_list, 0, buf);
1da177e4 214
cf9b1106
PM
215 /* Call flush even twice. It tries harder with a single online CPU */
216 printk_nmi_flush_on_panic();
6723734c
KC
217 kmsg_dump(KMSG_DUMP_PANIC);
218
f06e5153
MH
219 /*
220 * If you doubt kdump always works fine in any situation,
221 * "crash_kexec_post_notifiers" offers you a chance to run
222 * panic_notifiers and dumping kmsg before kdump.
223 * Note: since some panic_notifiers can make crashed kernel
224 * more unstable, it can increase risks of the kdump failure too.
7bbee5ca
HK
225 *
226 * Bypass the panic_cpu check and call __crash_kexec directly.
f06e5153 227 */
b26e27dd 228 if (_crash_kexec_post_notifiers)
7bbee5ca 229 __crash_kexec(NULL);
f06e5153 230
d014e889
AK
231 bust_spinlocks(0);
232
08d78658
VK
233 /*
234 * We may have ended up stopping the CPU holding the lock (in
235 * smp_send_stop()) while still having some valuable data in the console
236 * buffer. Try to acquire the lock then release it regardless of the
7625b3a0
VK
237 * result. The release will also print the buffers out. Locks debug
238 * should be disabled to avoid reporting bad unlock balance when
239 * panic() is not being callled from OOPS.
08d78658 240 */
7625b3a0 241 debug_locks_off();
8d91f8b1 242 console_flush_on_panic();
08d78658 243
c7ff0d9c
TS
244 if (!panic_blink)
245 panic_blink = no_blink;
246
dc009d92 247 if (panic_timeout > 0) {
1da177e4 248 /*
c95dbf27
IM
249 * Delay timeout seconds before rebooting the machine.
250 * We can't use the "normal" timers since we just panicked.
251 */
d7c0847f 252 pr_emerg("Rebooting in %d seconds..", panic_timeout);
c95dbf27 253
c7ff0d9c 254 for (i = 0; i < panic_timeout * 1000; i += PANIC_TIMER_STEP) {
1da177e4 255 touch_nmi_watchdog();
c7ff0d9c
TS
256 if (i >= i_next) {
257 i += panic_blink(state ^= 1);
258 i_next = i + 3600 / PANIC_BLINK_SPD;
259 }
260 mdelay(PANIC_TIMER_STEP);
1da177e4 261 }
4302fbc8
HD
262 }
263 if (panic_timeout != 0) {
c95dbf27
IM
264 /*
265 * This will not be a clean reboot, with everything
266 * shutting down. But if there is a chance of
267 * rebooting the system it will be rebooted.
1da177e4 268 */
2f048ea8 269 emergency_restart();
1da177e4
LT
270 }
271#ifdef __sparc__
272 {
273 extern int stop_a_enabled;
a271c241 274 /* Make sure the user can actually press Stop-A (L1-A) */
1da177e4 275 stop_a_enabled = 1;
d7c0847f 276 pr_emerg("Press Stop-A (L1-A) to return to the boot prom\n");
1da177e4
LT
277 }
278#endif
347a8dc3 279#if defined(CONFIG_S390)
c95dbf27
IM
280 {
281 unsigned long caller;
282
283 caller = (unsigned long)__builtin_return_address(0);
284 disabled_wait(caller);
285 }
1da177e4 286#endif
d7c0847f 287 pr_emerg("---[ end Kernel panic - not syncing: %s\n", buf);
1da177e4 288 local_irq_enable();
c7ff0d9c 289 for (i = 0; ; i += PANIC_TIMER_STEP) {
c22db941 290 touch_softlockup_watchdog();
c7ff0d9c
TS
291 if (i >= i_next) {
292 i += panic_blink(state ^= 1);
293 i_next = i + 3600 / PANIC_BLINK_SPD;
294 }
295 mdelay(PANIC_TIMER_STEP);
1da177e4
LT
296 }
297}
298
299EXPORT_SYMBOL(panic);
300
c277e63f 301
25ddbb18 302struct tnt {
c95dbf27
IM
303 u8 bit;
304 char true;
305 char false;
25ddbb18
AK
306};
307
308static const struct tnt tnts[] = {
c95dbf27
IM
309 { TAINT_PROPRIETARY_MODULE, 'P', 'G' },
310 { TAINT_FORCED_MODULE, 'F', ' ' },
8c90487c 311 { TAINT_CPU_OUT_OF_SPEC, 'S', ' ' },
c95dbf27
IM
312 { TAINT_FORCED_RMMOD, 'R', ' ' },
313 { TAINT_MACHINE_CHECK, 'M', ' ' },
314 { TAINT_BAD_PAGE, 'B', ' ' },
315 { TAINT_USER, 'U', ' ' },
316 { TAINT_DIE, 'D', ' ' },
317 { TAINT_OVERRIDDEN_ACPI_TABLE, 'A', ' ' },
318 { TAINT_WARN, 'W', ' ' },
319 { TAINT_CRAP, 'C', ' ' },
92946bc7 320 { TAINT_FIRMWARE_WORKAROUND, 'I', ' ' },
2449b8ba 321 { TAINT_OOT_MODULE, 'O', ' ' },
57673c2b 322 { TAINT_UNSIGNED_MODULE, 'E', ' ' },
69361eef 323 { TAINT_SOFTLOCKUP, 'L', ' ' },
c5f45465 324 { TAINT_LIVEPATCH, 'K', ' ' },
25ddbb18
AK
325};
326
1da177e4
LT
327/**
328 * print_tainted - return a string to represent the kernel taint state.
329 *
330 * 'P' - Proprietary module has been loaded.
331 * 'F' - Module has been forcibly loaded.
332 * 'S' - SMP with CPUs not designed for SMP.
333 * 'R' - User forced a module unload.
9aa5e993 334 * 'M' - System experienced a machine check exception.
1da177e4 335 * 'B' - System has hit bad_page.
34f5a398 336 * 'U' - Userspace-defined naughtiness.
a8005992 337 * 'D' - Kernel has oopsed before
95b570c9
NH
338 * 'A' - ACPI table overridden.
339 * 'W' - Taint on warning.
061b1bd3 340 * 'C' - modules from drivers/staging are loaded.
92946bc7 341 * 'I' - Working around severe firmware bug.
2449b8ba 342 * 'O' - Out-of-tree module has been loaded.
57673c2b 343 * 'E' - Unsigned module has been loaded.
bc53a3f4 344 * 'L' - A soft lockup has previously occurred.
c5f45465 345 * 'K' - Kernel has been live patched.
1da177e4 346 *
fe002a41 347 * The string is overwritten by the next call to print_tainted().
1da177e4 348 */
1da177e4
LT
349const char *print_tainted(void)
350{
01284764 351 static char buf[ARRAY_SIZE(tnts) + sizeof("Tainted: ")];
25ddbb18
AK
352
353 if (tainted_mask) {
354 char *s;
355 int i;
356
357 s = buf + sprintf(buf, "Tainted: ");
358 for (i = 0; i < ARRAY_SIZE(tnts); i++) {
359 const struct tnt *t = &tnts[i];
360 *s++ = test_bit(t->bit, &tainted_mask) ?
361 t->true : t->false;
362 }
363 *s = 0;
364 } else
1da177e4 365 snprintf(buf, sizeof(buf), "Not tainted");
c95dbf27
IM
366
367 return buf;
1da177e4
LT
368}
369
25ddbb18 370int test_taint(unsigned flag)
1da177e4 371{
25ddbb18
AK
372 return test_bit(flag, &tainted_mask);
373}
374EXPORT_SYMBOL(test_taint);
375
376unsigned long get_taint(void)
377{
378 return tainted_mask;
1da177e4 379}
dd287796 380
373d4d09
RR
381/**
382 * add_taint: add a taint flag if not already set.
383 * @flag: one of the TAINT_* constants.
384 * @lockdep_ok: whether lock debugging is still OK.
385 *
386 * If something bad has gone wrong, you'll want @lockdebug_ok = false, but for
387 * some notewortht-but-not-corrupting cases, it can be set to true.
388 */
389void add_taint(unsigned flag, enum lockdep_ok lockdep_ok)
dd287796 390{
373d4d09 391 if (lockdep_ok == LOCKDEP_NOW_UNRELIABLE && __debug_locks_off())
d7c0847f 392 pr_warn("Disabling lock debugging due to kernel taint\n");
9eeba613 393
25ddbb18 394 set_bit(flag, &tainted_mask);
dd287796 395}
1da177e4 396EXPORT_SYMBOL(add_taint);
dd287796
AM
397
398static void spin_msec(int msecs)
399{
400 int i;
401
402 for (i = 0; i < msecs; i++) {
403 touch_nmi_watchdog();
404 mdelay(1);
405 }
406}
407
408/*
409 * It just happens that oops_enter() and oops_exit() are identically
410 * implemented...
411 */
412static void do_oops_enter_exit(void)
413{
414 unsigned long flags;
415 static int spin_counter;
416
417 if (!pause_on_oops)
418 return;
419
420 spin_lock_irqsave(&pause_on_oops_lock, flags);
421 if (pause_on_oops_flag == 0) {
422 /* This CPU may now print the oops message */
423 pause_on_oops_flag = 1;
424 } else {
425 /* We need to stall this CPU */
426 if (!spin_counter) {
427 /* This CPU gets to do the counting */
428 spin_counter = pause_on_oops;
429 do {
430 spin_unlock(&pause_on_oops_lock);
431 spin_msec(MSEC_PER_SEC);
432 spin_lock(&pause_on_oops_lock);
433 } while (--spin_counter);
434 pause_on_oops_flag = 0;
435 } else {
436 /* This CPU waits for a different one */
437 while (spin_counter) {
438 spin_unlock(&pause_on_oops_lock);
439 spin_msec(1);
440 spin_lock(&pause_on_oops_lock);
441 }
442 }
443 }
444 spin_unlock_irqrestore(&pause_on_oops_lock, flags);
445}
446
447/*
c95dbf27
IM
448 * Return true if the calling CPU is allowed to print oops-related info.
449 * This is a bit racy..
dd287796
AM
450 */
451int oops_may_print(void)
452{
453 return pause_on_oops_flag == 0;
454}
455
456/*
457 * Called when the architecture enters its oops handler, before it prints
c95dbf27
IM
458 * anything. If this is the first CPU to oops, and it's oopsing the first
459 * time then let it proceed.
dd287796 460 *
c95dbf27
IM
461 * This is all enabled by the pause_on_oops kernel boot option. We do all
462 * this to ensure that oopses don't scroll off the screen. It has the
463 * side-effect of preventing later-oopsing CPUs from mucking up the display,
464 * too.
dd287796 465 *
c95dbf27
IM
466 * It turns out that the CPU which is allowed to print ends up pausing for
467 * the right duration, whereas all the other CPUs pause for twice as long:
468 * once in oops_enter(), once in oops_exit().
dd287796
AM
469 */
470void oops_enter(void)
471{
bdff7870 472 tracing_off();
c95dbf27
IM
473 /* can't trust the integrity of the kernel anymore: */
474 debug_locks_off();
dd287796
AM
475 do_oops_enter_exit();
476}
477
2c3b20e9
AV
478/*
479 * 64-bit random ID for oopses:
480 */
481static u64 oops_id;
482
483static int init_oops_id(void)
484{
485 if (!oops_id)
486 get_random_bytes(&oops_id, sizeof(oops_id));
d6624f99
AV
487 else
488 oops_id++;
2c3b20e9
AV
489
490 return 0;
491}
492late_initcall(init_oops_id);
493
863a6049 494void print_oops_end_marker(void)
71c33911
AV
495{
496 init_oops_id();
d7c0847f 497 pr_warn("---[ end trace %016llx ]---\n", (unsigned long long)oops_id);
71c33911
AV
498}
499
dd287796
AM
500/*
501 * Called when the architecture exits its oops handler, after printing
502 * everything.
503 */
504void oops_exit(void)
505{
506 do_oops_enter_exit();
71c33911 507 print_oops_end_marker();
456b565c 508 kmsg_dump(KMSG_DUMP_OOPS);
dd287796 509}
3162f751 510
2553b67a 511struct warn_args {
0f6f49a8 512 const char *fmt;
a8f18b90 513 va_list args;
0f6f49a8 514};
bd89bb29 515
2553b67a
JP
516void __warn(const char *file, int line, void *caller, unsigned taint,
517 struct pt_regs *regs, struct warn_args *args)
0f6f49a8 518{
de7edd31
SRRH
519 disable_trace_on_warning();
520
dcb6b452 521 pr_warn("------------[ cut here ]------------\n");
2553b67a
JP
522
523 if (file)
524 pr_warn("WARNING: CPU: %d PID: %d at %s:%d %pS\n",
525 raw_smp_processor_id(), current->pid, file, line,
526 caller);
527 else
528 pr_warn("WARNING: CPU: %d PID: %d at %pS\n",
529 raw_smp_processor_id(), current->pid, caller);
74853dba 530
0f6f49a8
LT
531 if (args)
532 vprintk(args->fmt, args->args);
a8f18b90 533
9e3961a0
PB
534 if (panic_on_warn) {
535 /*
536 * This thread may hit another WARN() in the panic path.
537 * Resetting this prevents additional WARN() from panicking the
538 * system on this thread. Other threads are blocked by the
539 * panic_mutex in panic().
540 */
541 panic_on_warn = 0;
542 panic("panic_on_warn set ...\n");
543 }
544
a8f18b90 545 print_modules();
2553b67a
JP
546
547 if (regs)
548 show_regs(regs);
549 else
550 dump_stack();
551
a8f18b90 552 print_oops_end_marker();
2553b67a 553
373d4d09
RR
554 /* Just a warning, don't kill lockdep. */
555 add_taint(taint, LOCKDEP_STILL_OK);
a8f18b90 556}
0f6f49a8 557
2553b67a 558#ifdef WANT_WARN_ON_SLOWPATH
0f6f49a8
LT
559void warn_slowpath_fmt(const char *file, int line, const char *fmt, ...)
560{
2553b67a 561 struct warn_args args;
0f6f49a8
LT
562
563 args.fmt = fmt;
564 va_start(args.args, fmt);
2553b67a
JP
565 __warn(file, line, __builtin_return_address(0), TAINT_WARN, NULL,
566 &args);
0f6f49a8
LT
567 va_end(args.args);
568}
57adc4d2
AK
569EXPORT_SYMBOL(warn_slowpath_fmt);
570
b2be0527
BH
571void warn_slowpath_fmt_taint(const char *file, int line,
572 unsigned taint, const char *fmt, ...)
573{
2553b67a 574 struct warn_args args;
b2be0527
BH
575
576 args.fmt = fmt;
577 va_start(args.args, fmt);
2553b67a 578 __warn(file, line, __builtin_return_address(0), taint, NULL, &args);
b2be0527
BH
579 va_end(args.args);
580}
581EXPORT_SYMBOL(warn_slowpath_fmt_taint);
582
57adc4d2
AK
583void warn_slowpath_null(const char *file, int line)
584{
2553b67a 585 __warn(file, line, __builtin_return_address(0), TAINT_WARN, NULL, NULL);
57adc4d2
AK
586}
587EXPORT_SYMBOL(warn_slowpath_null);
79b4cc5e
AV
588#endif
589
3162f751 590#ifdef CONFIG_CC_STACKPROTECTOR
54371a43 591
3162f751
AV
592/*
593 * Called when gcc's -fstack-protector feature is used, and
594 * gcc detects corruption of the on-stack canary value
595 */
a7330c99 596__visible void __stack_chk_fail(void)
3162f751 597{
517a92c4
IM
598 panic("stack-protector: Kernel stack is corrupted in: %p\n",
599 __builtin_return_address(0));
3162f751
AV
600}
601EXPORT_SYMBOL(__stack_chk_fail);
54371a43 602
3162f751 603#endif
f44dd164
RR
604
605core_param(panic, panic_timeout, int, 0644);
606core_param(pause_on_oops, pause_on_oops, int, 0644);
9e3961a0 607core_param(panic_on_warn, panic_on_warn, int, 0644);
b26e27dd 608core_param(crash_kexec_post_notifiers, crash_kexec_post_notifiers, bool, 0644);
f06e5153 609
d404ab0a
OH
610static int __init oops_setup(char *s)
611{
612 if (!s)
613 return -EINVAL;
614 if (!strcmp(s, "panic"))
615 panic_on_oops = 1;
616 return 0;
617}
618early_param("oops", oops_setup);