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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 11#include <linux/debug_locks.h>
b17b0153 12#include <linux/sched/debug.h>
c95dbf27 13#include <linux/interrupt.h>
456b565c 14#include <linux/kmsg_dump.h>
c95dbf27
IM
15#include <linux/kallsyms.h>
16#include <linux/notifier.h>
1da177e4 17#include <linux/module.h>
c95dbf27 18#include <linux/random.h>
de7edd31 19#include <linux/ftrace.h>
1da177e4 20#include <linux/reboot.h>
c95dbf27
IM
21#include <linux/delay.h>
22#include <linux/kexec.h>
23#include <linux/sched.h>
1da177e4 24#include <linux/sysrq.h>
c95dbf27 25#include <linux/init.h>
1da177e4 26#include <linux/nmi.h>
08d78658 27#include <linux/console.h>
2553b67a 28#include <linux/bug.h>
7a46ec0e 29#include <linux/ratelimit.h>
b1fca27d
AK
30#include <linux/debugfs.h>
31#include <asm/sections.h>
1da177e4 32
c7ff0d9c
TS
33#define PANIC_TIMER_STEP 100
34#define PANIC_BLINK_SPD 18
35
2a01bb38 36int panic_on_oops = CONFIG_PANIC_ON_OOPS_VALUE;
25ddbb18 37static unsigned long tainted_mask;
dd287796
AM
38static int pause_on_oops;
39static int pause_on_oops_flag;
40static DEFINE_SPINLOCK(pause_on_oops_lock);
5375b708 41bool crash_kexec_post_notifiers;
9e3961a0 42int panic_on_warn __read_mostly;
1da177e4 43
5800dc3c 44int panic_timeout = CONFIG_PANIC_TIMEOUT;
81e88fdc 45EXPORT_SYMBOL_GPL(panic_timeout);
1da177e4 46
e041c683 47ATOMIC_NOTIFIER_HEAD(panic_notifier_list);
1da177e4
LT
48
49EXPORT_SYMBOL(panic_notifier_list);
50
c7ff0d9c 51static long no_blink(int state)
8aeee85a 52{
c7ff0d9c 53 return 0;
8aeee85a
AB
54}
55
c7ff0d9c
TS
56/* Returns how long it waited in ms */
57long (*panic_blink)(int state);
58EXPORT_SYMBOL(panic_blink);
59
93e13a36
MH
60/*
61 * Stop ourself in panic -- architecture code may override this
62 */
63void __weak panic_smp_self_stop(void)
64{
65 while (1)
66 cpu_relax();
67}
68
58c5661f
HK
69/*
70 * Stop ourselves in NMI context if another CPU has already panicked. Arch code
71 * may override this to prepare for crash dumping, e.g. save regs info.
72 */
73void __weak nmi_panic_self_stop(struct pt_regs *regs)
74{
75 panic_smp_self_stop();
76}
77
0ee59413
HK
78/*
79 * Stop other CPUs in panic. Architecture dependent code may override this
80 * with more suitable version. For example, if the architecture supports
81 * crash dump, it should save registers of each stopped CPU and disable
82 * per-CPU features such as virtualization extensions.
83 */
84void __weak crash_smp_send_stop(void)
85{
86 static int cpus_stopped;
87
88 /*
89 * This function can be called twice in panic path, but obviously
90 * we execute this only once.
91 */
92 if (cpus_stopped)
93 return;
94
95 /*
96 * Note smp_send_stop is the usual smp shutdown function, which
97 * unfortunately means it may not be hardened to work in a panic
98 * situation.
99 */
100 smp_send_stop();
101 cpus_stopped = 1;
102}
103
1717f209
HK
104atomic_t panic_cpu = ATOMIC_INIT(PANIC_CPU_INVALID);
105
ebc41f20
HK
106/*
107 * A variant of panic() called from NMI context. We return if we've already
108 * panicked on this CPU. If another CPU already panicked, loop in
109 * nmi_panic_self_stop() which can provide architecture dependent code such
110 * as saving register state for crash dump.
111 */
112void nmi_panic(struct pt_regs *regs, const char *msg)
113{
114 int old_cpu, cpu;
115
116 cpu = raw_smp_processor_id();
117 old_cpu = atomic_cmpxchg(&panic_cpu, PANIC_CPU_INVALID, cpu);
118
119 if (old_cpu == PANIC_CPU_INVALID)
120 panic("%s", msg);
121 else if (old_cpu != cpu)
122 nmi_panic_self_stop(regs);
123}
124EXPORT_SYMBOL(nmi_panic);
125
1da177e4
LT
126/**
127 * panic - halt the system
128 * @fmt: The text string to print
129 *
130 * Display a message, then perform cleanups.
131 *
132 * This function never returns.
133 */
9402c95f 134void panic(const char *fmt, ...)
1da177e4 135{
1da177e4
LT
136 static char buf[1024];
137 va_list args;
c7ff0d9c
TS
138 long i, i_next = 0;
139 int state = 0;
1717f209 140 int old_cpu, this_cpu;
b26e27dd 141 bool _crash_kexec_post_notifiers = crash_kexec_post_notifiers;
1da177e4 142
190320c3
VM
143 /*
144 * Disable local interrupts. This will prevent panic_smp_self_stop
145 * from deadlocking the first cpu that invokes the panic, since
146 * there is nothing to prevent an interrupt handler (that runs
1717f209 147 * after setting panic_cpu) from invoking panic() again.
190320c3
VM
148 */
149 local_irq_disable();
150
dc009d92 151 /*
c95dbf27
IM
152 * It's possible to come here directly from a panic-assertion and
153 * not have preempt disabled. Some functions called from here want
dc009d92 154 * preempt to be disabled. No point enabling it later though...
93e13a36
MH
155 *
156 * Only one CPU is allowed to execute the panic code from here. For
157 * multiple parallel invocations of panic, all other CPUs either
158 * stop themself or will wait until they are stopped by the 1st CPU
159 * with smp_send_stop().
1717f209
HK
160 *
161 * `old_cpu == PANIC_CPU_INVALID' means this is the 1st CPU which
162 * comes here, so go ahead.
163 * `old_cpu == this_cpu' means we came from nmi_panic() which sets
164 * panic_cpu to this CPU. In this case, this is also the 1st CPU.
dc009d92 165 */
1717f209
HK
166 this_cpu = raw_smp_processor_id();
167 old_cpu = atomic_cmpxchg(&panic_cpu, PANIC_CPU_INVALID, this_cpu);
168
169 if (old_cpu != PANIC_CPU_INVALID && old_cpu != this_cpu)
93e13a36 170 panic_smp_self_stop();
dc009d92 171
5b530fc1 172 console_verbose();
1da177e4
LT
173 bust_spinlocks(1);
174 va_start(args, fmt);
175 vsnprintf(buf, sizeof(buf), fmt, args);
176 va_end(args);
d7c0847f 177 pr_emerg("Kernel panic - not syncing: %s\n", buf);
5cb27301 178#ifdef CONFIG_DEBUG_BUGVERBOSE
6e6f0a1f
AK
179 /*
180 * Avoid nested stack-dumping if a panic occurs during oops processing
181 */
026ee1f6 182 if (!test_taint(TAINT_DIE) && oops_in_progress <= 1)
6e6f0a1f 183 dump_stack();
5cb27301 184#endif
1da177e4 185
dc009d92
EB
186 /*
187 * If we have crashed and we have a crash kernel loaded let it handle
188 * everything else.
f06e5153
MH
189 * If we want to run this after calling panic_notifiers, pass
190 * the "crash_kexec_post_notifiers" option to the kernel.
7bbee5ca
HK
191 *
192 * Bypass the panic_cpu check and call __crash_kexec directly.
dc009d92 193 */
b26e27dd 194 if (!_crash_kexec_post_notifiers) {
f92bac3b 195 printk_safe_flush_on_panic();
7bbee5ca 196 __crash_kexec(NULL);
dc009d92 197
0ee59413
HK
198 /*
199 * Note smp_send_stop is the usual smp shutdown function, which
200 * unfortunately means it may not be hardened to work in a
201 * panic situation.
202 */
203 smp_send_stop();
204 } else {
205 /*
206 * If we want to do crash dump after notifier calls and
207 * kmsg_dump, we will need architecture dependent extra
208 * works in addition to stopping other CPUs.
209 */
210 crash_smp_send_stop();
211 }
1da177e4 212
6723734c
KC
213 /*
214 * Run any panic handlers, including those that might need to
215 * add information to the kmsg dump output.
216 */
e041c683 217 atomic_notifier_call_chain(&panic_notifier_list, 0, buf);
1da177e4 218
cf9b1106 219 /* Call flush even twice. It tries harder with a single online CPU */
f92bac3b 220 printk_safe_flush_on_panic();
6723734c
KC
221 kmsg_dump(KMSG_DUMP_PANIC);
222
f06e5153
MH
223 /*
224 * If you doubt kdump always works fine in any situation,
225 * "crash_kexec_post_notifiers" offers you a chance to run
226 * panic_notifiers and dumping kmsg before kdump.
227 * Note: since some panic_notifiers can make crashed kernel
228 * more unstable, it can increase risks of the kdump failure too.
7bbee5ca
HK
229 *
230 * Bypass the panic_cpu check and call __crash_kexec directly.
f06e5153 231 */
b26e27dd 232 if (_crash_kexec_post_notifiers)
7bbee5ca 233 __crash_kexec(NULL);
f06e5153 234
d014e889
AK
235 bust_spinlocks(0);
236
08d78658
VK
237 /*
238 * We may have ended up stopping the CPU holding the lock (in
239 * smp_send_stop()) while still having some valuable data in the console
240 * buffer. Try to acquire the lock then release it regardless of the
7625b3a0
VK
241 * result. The release will also print the buffers out. Locks debug
242 * should be disabled to avoid reporting bad unlock balance when
243 * panic() is not being callled from OOPS.
08d78658 244 */
7625b3a0 245 debug_locks_off();
8d91f8b1 246 console_flush_on_panic();
08d78658 247
c7ff0d9c
TS
248 if (!panic_blink)
249 panic_blink = no_blink;
250
dc009d92 251 if (panic_timeout > 0) {
1da177e4 252 /*
c95dbf27
IM
253 * Delay timeout seconds before rebooting the machine.
254 * We can't use the "normal" timers since we just panicked.
255 */
ff7a28a0 256 pr_emerg("Rebooting in %d seconds..\n", panic_timeout);
c95dbf27 257
c7ff0d9c 258 for (i = 0; i < panic_timeout * 1000; i += PANIC_TIMER_STEP) {
1da177e4 259 touch_nmi_watchdog();
c7ff0d9c
TS
260 if (i >= i_next) {
261 i += panic_blink(state ^= 1);
262 i_next = i + 3600 / PANIC_BLINK_SPD;
263 }
264 mdelay(PANIC_TIMER_STEP);
1da177e4 265 }
4302fbc8
HD
266 }
267 if (panic_timeout != 0) {
c95dbf27
IM
268 /*
269 * This will not be a clean reboot, with everything
270 * shutting down. But if there is a chance of
271 * rebooting the system it will be rebooted.
1da177e4 272 */
2f048ea8 273 emergency_restart();
1da177e4
LT
274 }
275#ifdef __sparc__
276 {
277 extern int stop_a_enabled;
a271c241 278 /* Make sure the user can actually press Stop-A (L1-A) */
1da177e4 279 stop_a_enabled = 1;
7db60d05
VK
280 pr_emerg("Press Stop-A (L1-A) from sun keyboard or send break\n"
281 "twice on console to return to the boot prom\n");
1da177e4
LT
282 }
283#endif
347a8dc3 284#if defined(CONFIG_S390)
c95dbf27
IM
285 {
286 unsigned long caller;
287
288 caller = (unsigned long)__builtin_return_address(0);
289 disabled_wait(caller);
290 }
1da177e4 291#endif
d7c0847f 292 pr_emerg("---[ end Kernel panic - not syncing: %s\n", buf);
1da177e4 293 local_irq_enable();
c7ff0d9c 294 for (i = 0; ; i += PANIC_TIMER_STEP) {
c22db941 295 touch_softlockup_watchdog();
c7ff0d9c
TS
296 if (i >= i_next) {
297 i += panic_blink(state ^= 1);
298 i_next = i + 3600 / PANIC_BLINK_SPD;
299 }
300 mdelay(PANIC_TIMER_STEP);
1da177e4
LT
301 }
302}
303
304EXPORT_SYMBOL(panic);
305
7fd8329b
PM
306/*
307 * TAINT_FORCED_RMMOD could be a per-module flag but the module
308 * is being removed anyway.
309 */
310const struct taint_flag taint_flags[TAINT_FLAGS_COUNT] = {
311 { 'P', 'G', true }, /* TAINT_PROPRIETARY_MODULE */
312 { 'F', ' ', true }, /* TAINT_FORCED_MODULE */
313 { 'S', ' ', false }, /* TAINT_CPU_OUT_OF_SPEC */
314 { 'R', ' ', false }, /* TAINT_FORCED_RMMOD */
315 { 'M', ' ', false }, /* TAINT_MACHINE_CHECK */
316 { 'B', ' ', false }, /* TAINT_BAD_PAGE */
317 { 'U', ' ', false }, /* TAINT_USER */
318 { 'D', ' ', false }, /* TAINT_DIE */
319 { 'A', ' ', false }, /* TAINT_OVERRIDDEN_ACPI_TABLE */
320 { 'W', ' ', false }, /* TAINT_WARN */
321 { 'C', ' ', true }, /* TAINT_CRAP */
322 { 'I', ' ', false }, /* TAINT_FIRMWARE_WORKAROUND */
323 { 'O', ' ', true }, /* TAINT_OOT_MODULE */
324 { 'E', ' ', true }, /* TAINT_UNSIGNED_MODULE */
325 { 'L', ' ', false }, /* TAINT_SOFTLOCKUP */
326 { 'K', ' ', true }, /* TAINT_LIVEPATCH */
4efb442c 327 { 'X', ' ', true }, /* TAINT_AUX */
25ddbb18
AK
328};
329
1da177e4
LT
330/**
331 * print_tainted - return a string to represent the kernel taint state.
332 *
333 * 'P' - Proprietary module has been loaded.
334 * 'F' - Module has been forcibly loaded.
335 * 'S' - SMP with CPUs not designed for SMP.
336 * 'R' - User forced a module unload.
9aa5e993 337 * 'M' - System experienced a machine check exception.
1da177e4 338 * 'B' - System has hit bad_page.
34f5a398 339 * 'U' - Userspace-defined naughtiness.
a8005992 340 * 'D' - Kernel has oopsed before
95b570c9
NH
341 * 'A' - ACPI table overridden.
342 * 'W' - Taint on warning.
061b1bd3 343 * 'C' - modules from drivers/staging are loaded.
92946bc7 344 * 'I' - Working around severe firmware bug.
2449b8ba 345 * 'O' - Out-of-tree module has been loaded.
57673c2b 346 * 'E' - Unsigned module has been loaded.
bc53a3f4 347 * 'L' - A soft lockup has previously occurred.
c5f45465 348 * 'K' - Kernel has been live patched.
4efb442c 349 * 'X' - Auxiliary taint, for distros' use.
1da177e4 350 *
fe002a41 351 * The string is overwritten by the next call to print_tainted().
1da177e4 352 */
1da177e4
LT
353const char *print_tainted(void)
354{
7fd8329b 355 static char buf[TAINT_FLAGS_COUNT + sizeof("Tainted: ")];
25ddbb18
AK
356
357 if (tainted_mask) {
358 char *s;
359 int i;
360
361 s = buf + sprintf(buf, "Tainted: ");
7fd8329b
PM
362 for (i = 0; i < TAINT_FLAGS_COUNT; i++) {
363 const struct taint_flag *t = &taint_flags[i];
364 *s++ = test_bit(i, &tainted_mask) ?
5eb7c0d0 365 t->c_true : t->c_false;
25ddbb18
AK
366 }
367 *s = 0;
368 } else
1da177e4 369 snprintf(buf, sizeof(buf), "Not tainted");
c95dbf27
IM
370
371 return buf;
1da177e4
LT
372}
373
25ddbb18 374int test_taint(unsigned flag)
1da177e4 375{
25ddbb18
AK
376 return test_bit(flag, &tainted_mask);
377}
378EXPORT_SYMBOL(test_taint);
379
380unsigned long get_taint(void)
381{
382 return tainted_mask;
1da177e4 383}
dd287796 384
373d4d09
RR
385/**
386 * add_taint: add a taint flag if not already set.
387 * @flag: one of the TAINT_* constants.
388 * @lockdep_ok: whether lock debugging is still OK.
389 *
390 * If something bad has gone wrong, you'll want @lockdebug_ok = false, but for
391 * some notewortht-but-not-corrupting cases, it can be set to true.
392 */
393void add_taint(unsigned flag, enum lockdep_ok lockdep_ok)
dd287796 394{
373d4d09 395 if (lockdep_ok == LOCKDEP_NOW_UNRELIABLE && __debug_locks_off())
d7c0847f 396 pr_warn("Disabling lock debugging due to kernel taint\n");
9eeba613 397
25ddbb18 398 set_bit(flag, &tainted_mask);
dd287796 399}
1da177e4 400EXPORT_SYMBOL(add_taint);
dd287796
AM
401
402static void spin_msec(int msecs)
403{
404 int i;
405
406 for (i = 0; i < msecs; i++) {
407 touch_nmi_watchdog();
408 mdelay(1);
409 }
410}
411
412/*
413 * It just happens that oops_enter() and oops_exit() are identically
414 * implemented...
415 */
416static void do_oops_enter_exit(void)
417{
418 unsigned long flags;
419 static int spin_counter;
420
421 if (!pause_on_oops)
422 return;
423
424 spin_lock_irqsave(&pause_on_oops_lock, flags);
425 if (pause_on_oops_flag == 0) {
426 /* This CPU may now print the oops message */
427 pause_on_oops_flag = 1;
428 } else {
429 /* We need to stall this CPU */
430 if (!spin_counter) {
431 /* This CPU gets to do the counting */
432 spin_counter = pause_on_oops;
433 do {
434 spin_unlock(&pause_on_oops_lock);
435 spin_msec(MSEC_PER_SEC);
436 spin_lock(&pause_on_oops_lock);
437 } while (--spin_counter);
438 pause_on_oops_flag = 0;
439 } else {
440 /* This CPU waits for a different one */
441 while (spin_counter) {
442 spin_unlock(&pause_on_oops_lock);
443 spin_msec(1);
444 spin_lock(&pause_on_oops_lock);
445 }
446 }
447 }
448 spin_unlock_irqrestore(&pause_on_oops_lock, flags);
449}
450
451/*
c95dbf27
IM
452 * Return true if the calling CPU is allowed to print oops-related info.
453 * This is a bit racy..
dd287796
AM
454 */
455int oops_may_print(void)
456{
457 return pause_on_oops_flag == 0;
458}
459
460/*
461 * Called when the architecture enters its oops handler, before it prints
c95dbf27
IM
462 * anything. If this is the first CPU to oops, and it's oopsing the first
463 * time then let it proceed.
dd287796 464 *
c95dbf27
IM
465 * This is all enabled by the pause_on_oops kernel boot option. We do all
466 * this to ensure that oopses don't scroll off the screen. It has the
467 * side-effect of preventing later-oopsing CPUs from mucking up the display,
468 * too.
dd287796 469 *
c95dbf27
IM
470 * It turns out that the CPU which is allowed to print ends up pausing for
471 * the right duration, whereas all the other CPUs pause for twice as long:
472 * once in oops_enter(), once in oops_exit().
dd287796
AM
473 */
474void oops_enter(void)
475{
bdff7870 476 tracing_off();
c95dbf27
IM
477 /* can't trust the integrity of the kernel anymore: */
478 debug_locks_off();
dd287796
AM
479 do_oops_enter_exit();
480}
481
2c3b20e9
AV
482/*
483 * 64-bit random ID for oopses:
484 */
485static u64 oops_id;
486
487static int init_oops_id(void)
488{
489 if (!oops_id)
490 get_random_bytes(&oops_id, sizeof(oops_id));
d6624f99
AV
491 else
492 oops_id++;
2c3b20e9
AV
493
494 return 0;
495}
496late_initcall(init_oops_id);
497
863a6049 498void print_oops_end_marker(void)
71c33911
AV
499{
500 init_oops_id();
d7c0847f 501 pr_warn("---[ end trace %016llx ]---\n", (unsigned long long)oops_id);
71c33911
AV
502}
503
dd287796
AM
504/*
505 * Called when the architecture exits its oops handler, after printing
506 * everything.
507 */
508void oops_exit(void)
509{
510 do_oops_enter_exit();
71c33911 511 print_oops_end_marker();
456b565c 512 kmsg_dump(KMSG_DUMP_OOPS);
dd287796 513}
3162f751 514
2553b67a 515struct warn_args {
0f6f49a8 516 const char *fmt;
a8f18b90 517 va_list args;
0f6f49a8 518};
bd89bb29 519
2553b67a
JP
520void __warn(const char *file, int line, void *caller, unsigned taint,
521 struct pt_regs *regs, struct warn_args *args)
0f6f49a8 522{
de7edd31
SRRH
523 disable_trace_on_warning();
524
a7bed27a
KC
525 if (args)
526 pr_warn(CUT_HERE);
2553b67a
JP
527
528 if (file)
529 pr_warn("WARNING: CPU: %d PID: %d at %s:%d %pS\n",
530 raw_smp_processor_id(), current->pid, file, line,
531 caller);
532 else
533 pr_warn("WARNING: CPU: %d PID: %d at %pS\n",
534 raw_smp_processor_id(), current->pid, caller);
74853dba 535
0f6f49a8
LT
536 if (args)
537 vprintk(args->fmt, args->args);
a8f18b90 538
9e3961a0
PB
539 if (panic_on_warn) {
540 /*
541 * This thread may hit another WARN() in the panic path.
542 * Resetting this prevents additional WARN() from panicking the
543 * system on this thread. Other threads are blocked by the
544 * panic_mutex in panic().
545 */
546 panic_on_warn = 0;
547 panic("panic_on_warn set ...\n");
548 }
549
a8f18b90 550 print_modules();
2553b67a
JP
551
552 if (regs)
553 show_regs(regs);
554 else
555 dump_stack();
556
a8f18b90 557 print_oops_end_marker();
2553b67a 558
373d4d09
RR
559 /* Just a warning, don't kill lockdep. */
560 add_taint(taint, LOCKDEP_STILL_OK);
a8f18b90 561}
0f6f49a8 562
2553b67a 563#ifdef WANT_WARN_ON_SLOWPATH
0f6f49a8
LT
564void warn_slowpath_fmt(const char *file, int line, const char *fmt, ...)
565{
2553b67a 566 struct warn_args args;
0f6f49a8
LT
567
568 args.fmt = fmt;
569 va_start(args.args, fmt);
2553b67a
JP
570 __warn(file, line, __builtin_return_address(0), TAINT_WARN, NULL,
571 &args);
0f6f49a8
LT
572 va_end(args.args);
573}
57adc4d2
AK
574EXPORT_SYMBOL(warn_slowpath_fmt);
575
b2be0527
BH
576void warn_slowpath_fmt_taint(const char *file, int line,
577 unsigned taint, const char *fmt, ...)
578{
2553b67a 579 struct warn_args args;
b2be0527
BH
580
581 args.fmt = fmt;
582 va_start(args.args, fmt);
2553b67a 583 __warn(file, line, __builtin_return_address(0), taint, NULL, &args);
b2be0527
BH
584 va_end(args.args);
585}
586EXPORT_SYMBOL(warn_slowpath_fmt_taint);
587
57adc4d2
AK
588void warn_slowpath_null(const char *file, int line)
589{
a7bed27a 590 pr_warn(CUT_HERE);
2553b67a 591 __warn(file, line, __builtin_return_address(0), TAINT_WARN, NULL, NULL);
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592}
593EXPORT_SYMBOL(warn_slowpath_null);
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594#else
595void __warn_printk(const char *fmt, ...)
596{
597 va_list args;
598
599 pr_warn(CUT_HERE);
600
601 va_start(args, fmt);
602 vprintk(fmt, args);
603 va_end(args);
604}
605EXPORT_SYMBOL(__warn_printk);
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606#endif
607
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608#ifdef CONFIG_BUG
609
610/* Support resetting WARN*_ONCE state */
611
612static int clear_warn_once_set(void *data, u64 val)
613{
aaf5dcfb 614 generic_bug_clear_once();
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615 memset(__start_once, 0, __end_once - __start_once);
616 return 0;
617}
618
619DEFINE_SIMPLE_ATTRIBUTE(clear_warn_once_fops,
620 NULL,
621 clear_warn_once_set,
622 "%lld\n");
623
624static __init int register_warn_debugfs(void)
625{
626 /* Don't care about failure */
aaf5dcfb 627 debugfs_create_file("clear_warn_once", 0200, NULL,
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628 NULL, &clear_warn_once_fops);
629 return 0;
630}
631
632device_initcall(register_warn_debugfs);
633#endif
634
3162f751 635#ifdef CONFIG_CC_STACKPROTECTOR
54371a43 636
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637/*
638 * Called when gcc's -fstack-protector feature is used, and
639 * gcc detects corruption of the on-stack canary value
640 */
a7330c99 641__visible void __stack_chk_fail(void)
3162f751 642{
ae5e66d2 643 panic("stack-protector: Kernel stack is corrupted in: %pB\n",
517a92c4 644 __builtin_return_address(0));
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645}
646EXPORT_SYMBOL(__stack_chk_fail);
54371a43 647
3162f751 648#endif
f44dd164 649
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650#ifdef CONFIG_ARCH_HAS_REFCOUNT
651void refcount_error_report(struct pt_regs *regs, const char *err)
652{
653 WARN_RATELIMIT(1, "refcount_t %s at %pB in %s[%d], uid/euid: %u/%u\n",
654 err, (void *)instruction_pointer(regs),
655 current->comm, task_pid_nr(current),
656 from_kuid_munged(&init_user_ns, current_uid()),
657 from_kuid_munged(&init_user_ns, current_euid()));
658}
659#endif
660
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661core_param(panic, panic_timeout, int, 0644);
662core_param(pause_on_oops, pause_on_oops, int, 0644);
9e3961a0 663core_param(panic_on_warn, panic_on_warn, int, 0644);
b26e27dd 664core_param(crash_kexec_post_notifiers, crash_kexec_post_notifiers, bool, 0644);
f06e5153 665
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666static int __init oops_setup(char *s)
667{
668 if (!s)
669 return -EINVAL;
670 if (!strcmp(s, "panic"))
671 panic_on_oops = 1;
672 return 0;
673}
674early_param("oops", oops_setup);