Line data Source code
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/sched.h>
27 : #include <linux/sysrq.h>
28 : #include <linux/init.h>
29 : #include <linux/nmi.h>
30 : #include <linux/console.h>
31 : #include <linux/bug.h>
32 : #include <linux/ratelimit.h>
33 : #include <linux/debugfs.h>
34 : #include <asm/sections.h>
35 :
36 : #define PANIC_TIMER_STEP 100
37 : #define PANIC_BLINK_SPD 18
38 :
39 : #ifdef CONFIG_SMP
40 : /*
41 : * Should we dump all CPUs backtraces in an oops event?
42 : * Defaults to 0, can be changed via sysctl.
43 : */
44 : unsigned int __read_mostly sysctl_oops_all_cpu_backtrace;
45 : #endif /* CONFIG_SMP */
46 :
47 : int panic_on_oops = CONFIG_PANIC_ON_OOPS_VALUE;
48 : static unsigned long tainted_mask =
49 : IS_ENABLED(CONFIG_GCC_PLUGIN_RANDSTRUCT) ? (1 << TAINT_RANDSTRUCT) : 0;
50 : static int pause_on_oops;
51 : static int pause_on_oops_flag;
52 : static DEFINE_SPINLOCK(pause_on_oops_lock);
53 : bool crash_kexec_post_notifiers;
54 : int panic_on_warn __read_mostly;
55 : unsigned long panic_on_taint;
56 : bool panic_on_taint_nousertaint = false;
57 :
58 : int panic_timeout = CONFIG_PANIC_TIMEOUT;
59 : EXPORT_SYMBOL_GPL(panic_timeout);
60 :
61 : #define PANIC_PRINT_TASK_INFO 0x00000001
62 : #define PANIC_PRINT_MEM_INFO 0x00000002
63 : #define PANIC_PRINT_TIMER_INFO 0x00000004
64 : #define PANIC_PRINT_LOCK_INFO 0x00000008
65 : #define PANIC_PRINT_FTRACE_INFO 0x00000010
66 : #define PANIC_PRINT_ALL_PRINTK_MSG 0x00000020
67 : unsigned long panic_print;
68 :
69 : ATOMIC_NOTIFIER_HEAD(panic_notifier_list);
70 :
71 : EXPORT_SYMBOL(panic_notifier_list);
72 :
73 0 : static long no_blink(int state)
74 : {
75 0 : return 0;
76 : }
77 :
78 : /* Returns how long it waited in ms */
79 : long (*panic_blink)(int state);
80 : EXPORT_SYMBOL(panic_blink);
81 :
82 : /*
83 : * Stop ourself in panic -- architecture code may override this
84 : */
85 0 : void __weak panic_smp_self_stop(void)
86 : {
87 0 : while (1)
88 0 : cpu_relax();
89 : }
90 :
91 : /*
92 : * Stop ourselves in NMI context if another CPU has already panicked. Arch code
93 : * may override this to prepare for crash dumping, e.g. save regs info.
94 : */
95 0 : void __weak nmi_panic_self_stop(struct pt_regs *regs)
96 : {
97 0 : panic_smp_self_stop();
98 0 : }
99 :
100 : /*
101 : * Stop other CPUs in panic. Architecture dependent code may override this
102 : * with more suitable version. For example, if the architecture supports
103 : * crash dump, it should save registers of each stopped CPU and disable
104 : * per-CPU features such as virtualization extensions.
105 : */
106 0 : void __weak crash_smp_send_stop(void)
107 : {
108 0 : static int cpus_stopped;
109 :
110 : /*
111 : * This function can be called twice in panic path, but obviously
112 : * we execute this only once.
113 : */
114 0 : if (cpus_stopped)
115 : return;
116 :
117 : /*
118 : * Note smp_send_stop is the usual smp shutdown function, which
119 : * unfortunately means it may not be hardened to work in a panic
120 : * situation.
121 : */
122 0 : smp_send_stop();
123 0 : cpus_stopped = 1;
124 : }
125 :
126 : atomic_t panic_cpu = ATOMIC_INIT(PANIC_CPU_INVALID);
127 :
128 : /*
129 : * A variant of panic() called from NMI context. We return if we've already
130 : * panicked on this CPU. If another CPU already panicked, loop in
131 : * nmi_panic_self_stop() which can provide architecture dependent code such
132 : * as saving register state for crash dump.
133 : */
134 0 : void nmi_panic(struct pt_regs *regs, const char *msg)
135 : {
136 0 : int old_cpu, cpu;
137 :
138 0 : cpu = raw_smp_processor_id();
139 0 : old_cpu = atomic_cmpxchg(&panic_cpu, PANIC_CPU_INVALID, cpu);
140 :
141 0 : if (old_cpu == PANIC_CPU_INVALID)
142 0 : panic("%s", msg);
143 0 : else if (old_cpu != cpu)
144 0 : nmi_panic_self_stop(regs);
145 0 : }
146 : EXPORT_SYMBOL(nmi_panic);
147 :
148 0 : static void panic_print_sys_info(void)
149 : {
150 0 : if (panic_print & PANIC_PRINT_ALL_PRINTK_MSG)
151 0 : console_flush_on_panic(CONSOLE_REPLAY_ALL);
152 :
153 0 : if (panic_print & PANIC_PRINT_TASK_INFO)
154 0 : show_state();
155 :
156 0 : if (panic_print & PANIC_PRINT_MEM_INFO)
157 0 : show_mem(0, NULL);
158 :
159 0 : if (panic_print & PANIC_PRINT_TIMER_INFO)
160 0 : sysrq_timer_list_show();
161 :
162 0 : if (panic_print & PANIC_PRINT_LOCK_INFO)
163 0 : debug_show_all_locks();
164 :
165 0 : if (panic_print & PANIC_PRINT_FTRACE_INFO)
166 0 : ftrace_dump(DUMP_ALL);
167 0 : }
168 :
169 : /**
170 : * panic - halt the system
171 : * @fmt: The text string to print
172 : *
173 : * Display a message, then perform cleanups.
174 : *
175 : * This function never returns.
176 : */
177 0 : void panic(const char *fmt, ...)
178 : {
179 0 : static char buf[1024];
180 0 : va_list args;
181 0 : long i, i_next = 0, len;
182 0 : int state = 0;
183 0 : int old_cpu, this_cpu;
184 0 : bool _crash_kexec_post_notifiers = crash_kexec_post_notifiers;
185 :
186 : /*
187 : * Disable local interrupts. This will prevent panic_smp_self_stop
188 : * from deadlocking the first cpu that invokes the panic, since
189 : * there is nothing to prevent an interrupt handler (that runs
190 : * after setting panic_cpu) from invoking panic() again.
191 : */
192 0 : local_irq_disable();
193 0 : preempt_disable_notrace();
194 :
195 : /*
196 : * It's possible to come here directly from a panic-assertion and
197 : * not have preempt disabled. Some functions called from here want
198 : * preempt to be disabled. No point enabling it later though...
199 : *
200 : * Only one CPU is allowed to execute the panic code from here. For
201 : * multiple parallel invocations of panic, all other CPUs either
202 : * stop themself or will wait until they are stopped by the 1st CPU
203 : * with smp_send_stop().
204 : *
205 : * `old_cpu == PANIC_CPU_INVALID' means this is the 1st CPU which
206 : * comes here, so go ahead.
207 : * `old_cpu == this_cpu' means we came from nmi_panic() which sets
208 : * panic_cpu to this CPU. In this case, this is also the 1st CPU.
209 : */
210 0 : this_cpu = raw_smp_processor_id();
211 0 : old_cpu = atomic_cmpxchg(&panic_cpu, PANIC_CPU_INVALID, this_cpu);
212 :
213 0 : if (old_cpu != PANIC_CPU_INVALID && old_cpu != this_cpu)
214 0 : panic_smp_self_stop();
215 :
216 0 : console_verbose();
217 0 : bust_spinlocks(1);
218 0 : va_start(args, fmt);
219 0 : len = vscnprintf(buf, sizeof(buf), fmt, args);
220 0 : va_end(args);
221 :
222 0 : if (len && buf[len - 1] == '\n')
223 0 : buf[len - 1] = '\0';
224 :
225 0 : pr_emerg("Kernel panic - not syncing: %s\n", buf);
226 : #ifdef CONFIG_DEBUG_BUGVERBOSE
227 : /*
228 : * Avoid nested stack-dumping if a panic occurs during oops processing
229 : */
230 0 : if (!test_taint(TAINT_DIE) && oops_in_progress <= 1)
231 0 : dump_stack();
232 : #endif
233 :
234 : /*
235 : * If kgdb is enabled, give it a chance to run before we stop all
236 : * the other CPUs or else we won't be able to debug processes left
237 : * running on them.
238 : */
239 0 : kgdb_panic(buf);
240 :
241 : /*
242 : * If we have crashed and we have a crash kernel loaded let it handle
243 : * everything else.
244 : * If we want to run this after calling panic_notifiers, pass
245 : * the "crash_kexec_post_notifiers" option to the kernel.
246 : *
247 : * Bypass the panic_cpu check and call __crash_kexec directly.
248 : */
249 0 : if (!_crash_kexec_post_notifiers) {
250 0 : printk_safe_flush_on_panic();
251 0 : __crash_kexec(NULL);
252 :
253 : /*
254 : * Note smp_send_stop is the usual smp shutdown function, which
255 : * unfortunately means it may not be hardened to work in a
256 : * panic situation.
257 : */
258 0 : smp_send_stop();
259 : } else {
260 : /*
261 : * If we want to do crash dump after notifier calls and
262 : * kmsg_dump, we will need architecture dependent extra
263 : * works in addition to stopping other CPUs.
264 : */
265 0 : crash_smp_send_stop();
266 : }
267 :
268 : /*
269 : * Run any panic handlers, including those that might need to
270 : * add information to the kmsg dump output.
271 : */
272 0 : atomic_notifier_call_chain(&panic_notifier_list, 0, buf);
273 :
274 : /* Call flush even twice. It tries harder with a single online CPU */
275 0 : printk_safe_flush_on_panic();
276 0 : kmsg_dump(KMSG_DUMP_PANIC);
277 :
278 : /*
279 : * If you doubt kdump always works fine in any situation,
280 : * "crash_kexec_post_notifiers" offers you a chance to run
281 : * panic_notifiers and dumping kmsg before kdump.
282 : * Note: since some panic_notifiers can make crashed kernel
283 : * more unstable, it can increase risks of the kdump failure too.
284 : *
285 : * Bypass the panic_cpu check and call __crash_kexec directly.
286 : */
287 0 : if (_crash_kexec_post_notifiers)
288 0 : __crash_kexec(NULL);
289 :
290 : #ifdef CONFIG_VT
291 0 : unblank_screen();
292 : #endif
293 0 : console_unblank();
294 :
295 : /*
296 : * We may have ended up stopping the CPU holding the lock (in
297 : * smp_send_stop()) while still having some valuable data in the console
298 : * buffer. Try to acquire the lock then release it regardless of the
299 : * result. The release will also print the buffers out. Locks debug
300 : * should be disabled to avoid reporting bad unlock balance when
301 : * panic() is not being callled from OOPS.
302 : */
303 0 : debug_locks_off();
304 0 : console_flush_on_panic(CONSOLE_FLUSH_PENDING);
305 :
306 0 : panic_print_sys_info();
307 :
308 0 : if (!panic_blink)
309 0 : panic_blink = no_blink;
310 :
311 0 : if (panic_timeout > 0) {
312 : /*
313 : * Delay timeout seconds before rebooting the machine.
314 : * We can't use the "normal" timers since we just panicked.
315 : */
316 0 : pr_emerg("Rebooting in %d seconds..\n", panic_timeout);
317 :
318 0 : for (i = 0; i < panic_timeout * 1000; i += PANIC_TIMER_STEP) {
319 0 : touch_nmi_watchdog();
320 0 : if (i >= i_next) {
321 0 : i += panic_blink(state ^= 1);
322 0 : i_next = i + 3600 / PANIC_BLINK_SPD;
323 : }
324 0 : mdelay(PANIC_TIMER_STEP);
325 : }
326 : }
327 0 : if (panic_timeout != 0) {
328 : /*
329 : * This will not be a clean reboot, with everything
330 : * shutting down. But if there is a chance of
331 : * rebooting the system it will be rebooted.
332 : */
333 0 : if (panic_reboot_mode != REBOOT_UNDEFINED)
334 0 : reboot_mode = panic_reboot_mode;
335 0 : emergency_restart();
336 : }
337 : #ifdef __sparc__
338 : {
339 : extern int stop_a_enabled;
340 : /* Make sure the user can actually press Stop-A (L1-A) */
341 : stop_a_enabled = 1;
342 : pr_emerg("Press Stop-A (L1-A) from sun keyboard or send break\n"
343 : "twice on console to return to the boot prom\n");
344 : }
345 : #endif
346 : #if defined(CONFIG_S390)
347 : disabled_wait();
348 : #endif
349 0 : pr_emerg("---[ end Kernel panic - not syncing: %s ]---\n", buf);
350 :
351 : /* Do not scroll important messages printed above */
352 0 : suppress_printk = 1;
353 0 : local_irq_enable();
354 0 : for (i = 0; ; i += PANIC_TIMER_STEP) {
355 0 : touch_softlockup_watchdog();
356 0 : if (i >= i_next) {
357 0 : i += panic_blink(state ^= 1);
358 0 : i_next = i + 3600 / PANIC_BLINK_SPD;
359 : }
360 0 : mdelay(PANIC_TIMER_STEP);
361 : }
362 : }
363 :
364 : EXPORT_SYMBOL(panic);
365 :
366 : /*
367 : * TAINT_FORCED_RMMOD could be a per-module flag but the module
368 : * is being removed anyway.
369 : */
370 : const struct taint_flag taint_flags[TAINT_FLAGS_COUNT] = {
371 : [ TAINT_PROPRIETARY_MODULE ] = { 'P', 'G', true },
372 : [ TAINT_FORCED_MODULE ] = { 'F', ' ', true },
373 : [ TAINT_CPU_OUT_OF_SPEC ] = { 'S', ' ', false },
374 : [ TAINT_FORCED_RMMOD ] = { 'R', ' ', false },
375 : [ TAINT_MACHINE_CHECK ] = { 'M', ' ', false },
376 : [ TAINT_BAD_PAGE ] = { 'B', ' ', false },
377 : [ TAINT_USER ] = { 'U', ' ', false },
378 : [ TAINT_DIE ] = { 'D', ' ', false },
379 : [ TAINT_OVERRIDDEN_ACPI_TABLE ] = { 'A', ' ', false },
380 : [ TAINT_WARN ] = { 'W', ' ', false },
381 : [ TAINT_CRAP ] = { 'C', ' ', true },
382 : [ TAINT_FIRMWARE_WORKAROUND ] = { 'I', ' ', false },
383 : [ TAINT_OOT_MODULE ] = { 'O', ' ', true },
384 : [ TAINT_UNSIGNED_MODULE ] = { 'E', ' ', true },
385 : [ TAINT_SOFTLOCKUP ] = { 'L', ' ', false },
386 : [ TAINT_LIVEPATCH ] = { 'K', ' ', true },
387 : [ TAINT_AUX ] = { 'X', ' ', true },
388 : [ TAINT_RANDSTRUCT ] = { 'T', ' ', true },
389 : };
390 :
391 : /**
392 : * print_tainted - return a string to represent the kernel taint state.
393 : *
394 : * For individual taint flag meanings, see Documentation/admin-guide/sysctl/kernel.rst
395 : *
396 : * The string is overwritten by the next call to print_tainted(),
397 : * but is always NULL terminated.
398 : */
399 1 : const char *print_tainted(void)
400 : {
401 1 : static char buf[TAINT_FLAGS_COUNT + sizeof("Tainted: ")];
402 :
403 1 : BUILD_BUG_ON(ARRAY_SIZE(taint_flags) != TAINT_FLAGS_COUNT);
404 :
405 1 : if (tainted_mask) {
406 0 : char *s;
407 0 : int i;
408 :
409 0 : s = buf + sprintf(buf, "Tainted: ");
410 0 : for (i = 0; i < TAINT_FLAGS_COUNT; i++) {
411 0 : const struct taint_flag *t = &taint_flags[i];
412 0 : *s++ = test_bit(i, &tainted_mask) ?
413 : t->c_true : t->c_false;
414 : }
415 0 : *s = 0;
416 : } else
417 1 : snprintf(buf, sizeof(buf), "Not tainted");
418 :
419 1 : return buf;
420 : }
421 :
422 0 : int test_taint(unsigned flag)
423 : {
424 0 : return test_bit(flag, &tainted_mask);
425 : }
426 : EXPORT_SYMBOL(test_taint);
427 :
428 0 : unsigned long get_taint(void)
429 : {
430 0 : return tainted_mask;
431 : }
432 :
433 : /**
434 : * add_taint: add a taint flag if not already set.
435 : * @flag: one of the TAINT_* constants.
436 : * @lockdep_ok: whether lock debugging is still OK.
437 : *
438 : * If something bad has gone wrong, you'll want @lockdebug_ok = false, but for
439 : * some notewortht-but-not-corrupting cases, it can be set to true.
440 : */
441 1 : void add_taint(unsigned flag, enum lockdep_ok lockdep_ok)
442 : {
443 1 : if (lockdep_ok == LOCKDEP_NOW_UNRELIABLE && __debug_locks_off())
444 0 : pr_warn("Disabling lock debugging due to kernel taint\n");
445 :
446 1 : set_bit(flag, &tainted_mask);
447 :
448 1 : if (tainted_mask & panic_on_taint) {
449 0 : panic_on_taint = 0;
450 0 : panic("panic_on_taint set ...");
451 : }
452 1 : }
453 : EXPORT_SYMBOL(add_taint);
454 :
455 0 : static void spin_msec(int msecs)
456 : {
457 0 : int i;
458 :
459 0 : for (i = 0; i < msecs; i++) {
460 0 : touch_nmi_watchdog();
461 0 : mdelay(1);
462 : }
463 : }
464 :
465 : /*
466 : * It just happens that oops_enter() and oops_exit() are identically
467 : * implemented...
468 : */
469 0 : static void do_oops_enter_exit(void)
470 : {
471 0 : unsigned long flags;
472 0 : static int spin_counter;
473 :
474 0 : if (!pause_on_oops)
475 : return;
476 :
477 0 : spin_lock_irqsave(&pause_on_oops_lock, flags);
478 0 : if (pause_on_oops_flag == 0) {
479 : /* This CPU may now print the oops message */
480 0 : pause_on_oops_flag = 1;
481 : } else {
482 : /* We need to stall this CPU */
483 0 : if (!spin_counter) {
484 : /* This CPU gets to do the counting */
485 0 : spin_counter = pause_on_oops;
486 0 : do {
487 0 : spin_unlock(&pause_on_oops_lock);
488 0 : spin_msec(MSEC_PER_SEC);
489 0 : spin_lock(&pause_on_oops_lock);
490 0 : } while (--spin_counter);
491 0 : pause_on_oops_flag = 0;
492 : } else {
493 : /* This CPU waits for a different one */
494 0 : while (spin_counter) {
495 0 : spin_unlock(&pause_on_oops_lock);
496 0 : spin_msec(1);
497 0 : spin_lock(&pause_on_oops_lock);
498 : }
499 : }
500 : }
501 0 : spin_unlock_irqrestore(&pause_on_oops_lock, flags);
502 : }
503 :
504 : /*
505 : * Return true if the calling CPU is allowed to print oops-related info.
506 : * This is a bit racy..
507 : */
508 0 : bool oops_may_print(void)
509 : {
510 0 : return pause_on_oops_flag == 0;
511 : }
512 :
513 : /*
514 : * Called when the architecture enters its oops handler, before it prints
515 : * anything. If this is the first CPU to oops, and it's oopsing the first
516 : * time then let it proceed.
517 : *
518 : * This is all enabled by the pause_on_oops kernel boot option. We do all
519 : * this to ensure that oopses don't scroll off the screen. It has the
520 : * side-effect of preventing later-oopsing CPUs from mucking up the display,
521 : * too.
522 : *
523 : * It turns out that the CPU which is allowed to print ends up pausing for
524 : * the right duration, whereas all the other CPUs pause for twice as long:
525 : * once in oops_enter(), once in oops_exit().
526 : */
527 0 : void oops_enter(void)
528 : {
529 0 : tracing_off();
530 : /* can't trust the integrity of the kernel anymore: */
531 0 : debug_locks_off();
532 0 : do_oops_enter_exit();
533 :
534 0 : if (sysctl_oops_all_cpu_backtrace)
535 0 : trigger_all_cpu_backtrace();
536 0 : }
537 :
538 : /*
539 : * 64-bit random ID for oopses:
540 : */
541 : static u64 oops_id;
542 :
543 2 : static int init_oops_id(void)
544 : {
545 2 : if (!oops_id)
546 1 : get_random_bytes(&oops_id, sizeof(oops_id));
547 : else
548 1 : oops_id++;
549 :
550 2 : return 0;
551 : }
552 : late_initcall(init_oops_id);
553 :
554 1 : static void print_oops_end_marker(void)
555 : {
556 1 : init_oops_id();
557 1 : pr_warn("---[ end trace %016llx ]---\n", (unsigned long long)oops_id);
558 1 : }
559 :
560 : /*
561 : * Called when the architecture exits its oops handler, after printing
562 : * everything.
563 : */
564 0 : void oops_exit(void)
565 : {
566 0 : do_oops_enter_exit();
567 0 : print_oops_end_marker();
568 0 : kmsg_dump(KMSG_DUMP_OOPS);
569 0 : }
570 :
571 : struct warn_args {
572 : const char *fmt;
573 : va_list args;
574 : };
575 :
576 1 : void __warn(const char *file, int line, void *caller, unsigned taint,
577 : struct pt_regs *regs, struct warn_args *args)
578 : {
579 1 : disable_trace_on_warning();
580 :
581 1 : if (file)
582 1 : pr_warn("WARNING: CPU: %d PID: %d at %s:%d %pS\n",
583 : raw_smp_processor_id(), current->pid, file, line,
584 : caller);
585 : else
586 0 : pr_warn("WARNING: CPU: %d PID: %d at %pS\n",
587 : raw_smp_processor_id(), current->pid, caller);
588 :
589 1 : if (args)
590 0 : vprintk(args->fmt, args->args);
591 :
592 1 : print_modules();
593 :
594 1 : if (regs)
595 1 : show_regs(regs);
596 :
597 1 : if (panic_on_warn) {
598 : /*
599 : * This thread may hit another WARN() in the panic path.
600 : * Resetting this prevents additional WARN() from panicking the
601 : * system on this thread. Other threads are blocked by the
602 : * panic_mutex in panic().
603 : */
604 0 : panic_on_warn = 0;
605 0 : panic("panic_on_warn set ...\n");
606 : }
607 :
608 1 : if (!regs)
609 0 : dump_stack();
610 :
611 1 : print_irqtrace_events(current);
612 :
613 1 : print_oops_end_marker();
614 :
615 : /* Just a warning, don't kill lockdep. */
616 1 : add_taint(taint, LOCKDEP_STILL_OK);
617 1 : }
618 :
619 : #ifndef __WARN_FLAGS
620 : void warn_slowpath_fmt(const char *file, int line, unsigned taint,
621 : const char *fmt, ...)
622 : {
623 : struct warn_args args;
624 :
625 : pr_warn(CUT_HERE);
626 :
627 : if (!fmt) {
628 : __warn(file, line, __builtin_return_address(0), taint,
629 : NULL, NULL);
630 : return;
631 : }
632 :
633 : args.fmt = fmt;
634 : va_start(args.args, fmt);
635 : __warn(file, line, __builtin_return_address(0), taint, NULL, &args);
636 : va_end(args.args);
637 : }
638 : EXPORT_SYMBOL(warn_slowpath_fmt);
639 : #else
640 1 : void __warn_printk(const char *fmt, ...)
641 : {
642 1 : va_list args;
643 :
644 1 : pr_warn(CUT_HERE);
645 :
646 1 : va_start(args, fmt);
647 1 : vprintk(fmt, args);
648 1 : va_end(args);
649 1 : }
650 : EXPORT_SYMBOL(__warn_printk);
651 : #endif
652 :
653 : #ifdef CONFIG_BUG
654 :
655 : /* Support resetting WARN*_ONCE state */
656 :
657 0 : static int clear_warn_once_set(void *data, u64 val)
658 : {
659 0 : generic_bug_clear_once();
660 0 : memset(__start_once, 0, __end_once - __start_once);
661 0 : return 0;
662 : }
663 :
664 0 : DEFINE_DEBUGFS_ATTRIBUTE(clear_warn_once_fops, NULL, clear_warn_once_set,
665 : "%lld\n");
666 :
667 1 : static __init int register_warn_debugfs(void)
668 : {
669 : /* Don't care about failure */
670 1 : debugfs_create_file_unsafe("clear_warn_once", 0200, NULL, NULL,
671 : &clear_warn_once_fops);
672 1 : return 0;
673 : }
674 :
675 : device_initcall(register_warn_debugfs);
676 : #endif
677 :
678 : #ifdef CONFIG_STACKPROTECTOR
679 :
680 : /*
681 : * Called when gcc's -fstack-protector feature is used, and
682 : * gcc detects corruption of the on-stack canary value
683 : */
684 : __visible noinstr void __stack_chk_fail(void)
685 : {
686 : instrumentation_begin();
687 : panic("stack-protector: Kernel stack is corrupted in: %pB",
688 : __builtin_return_address(0));
689 : instrumentation_end();
690 : }
691 : EXPORT_SYMBOL(__stack_chk_fail);
692 :
693 : #endif
694 :
695 : core_param(panic, panic_timeout, int, 0644);
696 : core_param(panic_print, panic_print, ulong, 0644);
697 : core_param(pause_on_oops, pause_on_oops, int, 0644);
698 : core_param(panic_on_warn, panic_on_warn, int, 0644);
699 : core_param(crash_kexec_post_notifiers, crash_kexec_post_notifiers, bool, 0644);
700 :
701 0 : static int __init oops_setup(char *s)
702 : {
703 0 : if (!s)
704 : return -EINVAL;
705 0 : if (!strcmp(s, "panic"))
706 0 : panic_on_oops = 1;
707 : return 0;
708 : }
709 : early_param("oops", oops_setup);
710 :
711 0 : static int __init panic_on_taint_setup(char *s)
712 : {
713 0 : char *taint_str;
714 :
715 0 : if (!s)
716 : return -EINVAL;
717 :
718 0 : taint_str = strsep(&s, ",");
719 0 : if (kstrtoul(taint_str, 16, &panic_on_taint))
720 : return -EINVAL;
721 :
722 : /* make sure panic_on_taint doesn't hold out-of-range TAINT flags */
723 0 : panic_on_taint &= TAINT_FLAGS_MAX;
724 :
725 0 : if (!panic_on_taint)
726 : return -EINVAL;
727 :
728 0 : if (s && !strcmp(s, "nousertaint"))
729 0 : panic_on_taint_nousertaint = true;
730 :
731 0 : pr_info("panic_on_taint: bitmask=0x%lx nousertaint_mode=%sabled\n",
732 : panic_on_taint, panic_on_taint_nousertaint ? "en" : "dis");
733 :
734 0 : return 0;
735 : }
736 : early_param("panic_on_taint", panic_on_taint_setup);
|
