projects/linux·blob v5.19-rc5 · refs

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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};
432
433/**
434 * print_tainted - return a string to represent the kernel taint state.
435 *
436 * For individual taint flag meanings, see Documentation/admin-guide/sysctl/kernel.rst
437 *
438 * The string is overwritten by the next call to print_tainted(),
439 * but is always NULL terminated.
440 */
441const char *print_tainted(void)
442{
443 static char buf[TAINT_FLAGS_COUNT + sizeof("Tainted: ")];
444
445 BUILD_BUG_ON(ARRAY_SIZE(taint_flags) != TAINT_FLAGS_COUNT);
446
447 if (tainted_mask) {
448 char *s;
449 int i;
450
451 s = buf + sprintf(buf, "Tainted: ");
452 for (i = 0; i < TAINT_FLAGS_COUNT; i++) {
453 const struct taint_flag *t = &taint_flags[i];
454 *s++ = test_bit(i, &tainted_mask) ?
455 t->c_true : t->c_false;
456 }
457 *s = 0;
458 } else
459 snprintf(buf, sizeof(buf), "Not tainted");
460
461 return buf;
462}
463
464int test_taint(unsigned flag)
465{
466 return test_bit(flag, &tainted_mask);
467}
468EXPORT_SYMBOL(test_taint);
469
470unsigned long get_taint(void)
471{
472 return tainted_mask;
473}
474
475/**
476 * add_taint: add a taint flag if not already set.
477 * @flag: one of the TAINT_* constants.
478 * @lockdep_ok: whether lock debugging is still OK.
479 *
480 * If something bad has gone wrong, you'll want @lockdebug_ok = false, but for
481 * some notewortht-but-not-corrupting cases, it can be set to true.
482 */
483void add_taint(unsigned flag, enum lockdep_ok lockdep_ok)
484{
485 if (lockdep_ok == LOCKDEP_NOW_UNRELIABLE && __debug_locks_off())
486 pr_warn("Disabling lock debugging due to kernel taint\n");
487
488 set_bit(flag, &tainted_mask);
489
490 if (tainted_mask & panic_on_taint) {
491 panic_on_taint = 0;
492 panic("panic_on_taint set ...");
493 }
494}
495EXPORT_SYMBOL(add_taint);
496
497static void spin_msec(int msecs)
498{
499 int i;
500
501 for (i = 0; i < msecs; i++) {
502 touch_nmi_watchdog();
503 mdelay(1);
504 }
505}
506
507/*
508 * It just happens that oops_enter() and oops_exit() are identically
509 * implemented...
510 */
511static void do_oops_enter_exit(void)
512{
513 unsigned long flags;
514 static int spin_counter;
515
516 if (!pause_on_oops)
517 return;
518
519 spin_lock_irqsave(&pause_on_oops_lock, flags);
520 if (pause_on_oops_flag == 0) {
521 /* This CPU may now print the oops message */
522 pause_on_oops_flag = 1;
523 } else {
524 /* We need to stall this CPU */
525 if (!spin_counter) {
526 /* This CPU gets to do the counting */
527 spin_counter = pause_on_oops;
528 do {
529 spin_unlock(&pause_on_oops_lock);
530 spin_msec(MSEC_PER_SEC);
531 spin_lock(&pause_on_oops_lock);
532 } while (--spin_counter);
533 pause_on_oops_flag = 0;
534 } else {
535 /* This CPU waits for a different one */
536 while (spin_counter) {
537 spin_unlock(&pause_on_oops_lock);
538 spin_msec(1);
539 spin_lock(&pause_on_oops_lock);
540 }
541 }
542 }
543 spin_unlock_irqrestore(&pause_on_oops_lock, flags);
544}
545
546/*
547 * Return true if the calling CPU is allowed to print oops-related info.
548 * This is a bit racy..
549 */
550bool oops_may_print(void)
551{
552 return pause_on_oops_flag == 0;
553}
554
555/*
556 * Called when the architecture enters its oops handler, before it prints
557 * anything. If this is the first CPU to oops, and it's oopsing the first
558 * time then let it proceed.
559 *
560 * This is all enabled by the pause_on_oops kernel boot option. We do all
561 * this to ensure that oopses don't scroll off the screen. It has the
562 * side-effect of preventing later-oopsing CPUs from mucking up the display,
563 * too.
564 *
565 * It turns out that the CPU which is allowed to print ends up pausing for
566 * the right duration, whereas all the other CPUs pause for twice as long:
567 * once in oops_enter(), once in oops_exit().
568 */
569void oops_enter(void)
570{
571 tracing_off();
572 /* can't trust the integrity of the kernel anymore: */
573 debug_locks_off();
574 do_oops_enter_exit();
575
576 if (sysctl_oops_all_cpu_backtrace)
577 trigger_all_cpu_backtrace();
578}
579
580static void print_oops_end_marker(void)
581{
582 pr_warn("---[ end trace %016llx ]---\n", 0ULL);
583}
584
585/*
586 * Called when the architecture exits its oops handler, after printing
587 * everything.
588 */
589void oops_exit(void)
590{
591 do_oops_enter_exit();
592 print_oops_end_marker();
593 kmsg_dump(KMSG_DUMP_OOPS);
594}
595
596struct warn_args {
597 const char *fmt;
598 va_list args;
599};
600
601void __warn(const char *file, int line, void *caller, unsigned taint,
602 struct pt_regs *regs, struct warn_args *args)
603{
604 disable_trace_on_warning();
605
606 if (file)
607 pr_warn("WARNING: CPU: %d PID: %d at %s:%d %pS\n",
608 raw_smp_processor_id(), current->pid, file, line,
609 caller);
610 else
611 pr_warn("WARNING: CPU: %d PID: %d at %pS\n",
612 raw_smp_processor_id(), current->pid, caller);
613
614 if (args)
615 vprintk(args->fmt, args->args);
616
617 print_modules();
618
619 if (regs)
620 show_regs(regs);
621
622 if (panic_on_warn)
623 panic("panic_on_warn set ...\n");
624
625 if (!regs)
626 dump_stack();
627
628 print_irqtrace_events(current);
629
630 print_oops_end_marker();
631 trace_error_report_end(ERROR_DETECTOR_WARN, (unsigned long)caller);
632
633 /* Just a warning, don't kill lockdep. */
634 add_taint(taint, LOCKDEP_STILL_OK);
635}
636
637#ifndef __WARN_FLAGS
638void warn_slowpath_fmt(const char *file, int line, unsigned taint,
639 const char *fmt, ...)
640{
641 struct warn_args args;
642
643 pr_warn(CUT_HERE);
644
645 if (!fmt) {
646 __warn(file, line, __builtin_return_address(0), taint,
647 NULL, NULL);
648 return;
649 }
650
651 args.fmt = fmt;
652 va_start(args.args, fmt);
653 __warn(file, line, __builtin_return_address(0), taint, NULL, &args);
654 va_end(args.args);
655}
656EXPORT_SYMBOL(warn_slowpath_fmt);
657#else
658void __warn_printk(const char *fmt, ...)
659{
660 va_list args;
661
662 pr_warn(CUT_HERE);
663
664 va_start(args, fmt);
665 vprintk(fmt, args);
666 va_end(args);
667}
668EXPORT_SYMBOL(__warn_printk);
669#endif
670
671#ifdef CONFIG_BUG
672
673/* Support resetting WARN*_ONCE state */
674
675static int clear_warn_once_set(void *data, u64 val)
676{
677 generic_bug_clear_once();
678 memset(__start_once, 0, __end_once - __start_once);
679 return 0;
680}
681
682DEFINE_DEBUGFS_ATTRIBUTE(clear_warn_once_fops, NULL, clear_warn_once_set,
683 "%lld\n");
684
685static __init int register_warn_debugfs(void)
686{
687 /* Don't care about failure */
688 debugfs_create_file_unsafe("clear_warn_once", 0200, NULL, NULL,
689 &clear_warn_once_fops);
690 return 0;
691}
692
693device_initcall(register_warn_debugfs);
694#endif
695
696#ifdef CONFIG_STACKPROTECTOR
697
698/*
699 * Called when gcc's -fstack-protector feature is used, and
700 * gcc detects corruption of the on-stack canary value
701 */
702__visible noinstr void __stack_chk_fail(void)
703{
704 instrumentation_begin();
705 panic("stack-protector: Kernel stack is corrupted in: %pB",
706 __builtin_return_address(0));
707 instrumentation_end();
708}
709EXPORT_SYMBOL(__stack_chk_fail);
710
711#endif
712
713core_param(panic, panic_timeout, int, 0644);
714core_param(panic_print, panic_print, ulong, 0644);
715core_param(pause_on_oops, pause_on_oops, int, 0644);
716core_param(panic_on_warn, panic_on_warn, int, 0644);
717core_param(crash_kexec_post_notifiers, crash_kexec_post_notifiers, bool, 0644);
718
719static int __init oops_setup(char *s)
720{
721 if (!s)
722 return -EINVAL;
723 if (!strcmp(s, "panic"))
724 panic_on_oops = 1;
725 return 0;
726}
727early_param("oops", oops_setup);
728
729static int __init panic_on_taint_setup(char *s)
730{
731 char *taint_str;
732
733 if (!s)
734 return -EINVAL;
735
736 taint_str = strsep(&s, ",");
737 if (kstrtoul(taint_str, 16, &panic_on_taint))
738 return -EINVAL;
739
740 /* make sure panic_on_taint doesn't hold out-of-range TAINT flags */
741 panic_on_taint &= TAINT_FLAGS_MAX;
742
743 if (!panic_on_taint)
744 return -EINVAL;
745
746 if (s && !strcmp(s, "nousertaint"))
747 panic_on_taint_nousertaint = true;
748
749 pr_info("panic_on_taint: bitmask=0x%lx nousertaint_mode=%sabled\n",
750 panic_on_taint, panic_on_taint_nousertaint ? "en" : "dis");
751
752 return 0;
753}
754early_param("panic_on_taint", panic_on_taint_setup);