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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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 */
Andrew Morton657b3012006-08-13 23:24:19 -070011#include <linux/debug_locks.h>
Ingo Molnarc95dbf22009-03-13 11:14:06 +010012#include <linux/interrupt.h>
Simon Kagstrom456b5652009-10-16 14:09:18 +020013#include <linux/kmsg_dump.h>
Arjan van de Ven79b4cc52008-01-30 13:32:50 +010014#include <linux/kallsyms.h>
Ingo Molnarc95dbf22009-03-13 11:14:06 +010015#include <linux/notifier.h>
16#include <linux/module.h>
17#include <linux/random.h>
Steven Rostedt (Red Hat)de7edd32013-06-14 16:21:43 -040018#include <linux/ftrace.h>
Ingo Molnarc95dbf22009-03-13 11:14:06 +010019#include <linux/reboot.h>
20#include <linux/delay.h>
21#include <linux/kexec.h>
22#include <linux/sched.h>
23#include <linux/sysrq.h>
24#include <linux/init.h>
25#include <linux/nmi.h>
Vitaly Kuznetsov08d78652015-11-06 16:32:58 -080026#include <linux/console.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070027
TAMUKI Shoichic7ff0d92010-08-10 18:03:28 -070028#define PANIC_TIMER_STEP 100
29#define PANIC_BLINK_SPD 18
30
Kyle McMartin2a01bb32012-04-11 08:15:29 -040031int panic_on_oops = CONFIG_PANIC_ON_OOPS_VALUE;
Andi Kleen25ddbb12008-10-15 22:01:41 -070032static unsigned long tainted_mask;
Andrew Mortondd287792006-03-23 03:00:57 -080033static int pause_on_oops;
34static int pause_on_oops_flag;
35static DEFINE_SPINLOCK(pause_on_oops_lock);
HATAYAMA Daisuke5375b702015-06-30 14:57:46 -070036bool crash_kexec_post_notifiers;
Prarit Bhargava9e3961a2014-12-10 15:45:50 -080037int panic_on_warn __read_mostly;
Linus Torvalds1da177e2005-04-16 15:20:36 -070038
Jason Baron5800dc32013-11-25 23:23:04 +000039int panic_timeout = CONFIG_PANIC_TIMEOUT;
Huang Ying81e88fd2011-01-12 14:44:55 +080040EXPORT_SYMBOL_GPL(panic_timeout);
Linus Torvalds1da177e2005-04-16 15:20:36 -070041
Alan Sterne041c682006-03-27 01:16:30 -080042ATOMIC_NOTIFIER_HEAD(panic_notifier_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -070043
44EXPORT_SYMBOL(panic_notifier_list);
45
TAMUKI Shoichic7ff0d92010-08-10 18:03:28 -070046static long no_blink(int state)
Anton Blanchard8aeee852010-03-05 13:42:55 -080047{
TAMUKI Shoichic7ff0d92010-08-10 18:03:28 -070048 return 0;
Anton Blanchard8aeee852010-03-05 13:42:55 -080049}
50
TAMUKI Shoichic7ff0d92010-08-10 18:03:28 -070051/* Returns how long it waited in ms */
52long (*panic_blink)(int state);
53EXPORT_SYMBOL(panic_blink);
54
Michael Holzheu93e13a32012-01-12 17:20:18 -080055/*
56 * Stop ourself in panic -- architecture code may override this
57 */
58void __weak panic_smp_self_stop(void)
59{
60 while (1)
61 cpu_relax();
62}
63
Hidehiro Kawai58c56612015-12-14 11:19:10 +010064/*
65 * Stop ourselves in NMI context if another CPU has already panicked. Arch code
66 * may override this to prepare for crash dumping, e.g. save regs info.
67 */
68void __weak nmi_panic_self_stop(struct pt_regs *regs)
69{
70 panic_smp_self_stop();
71}
72
Hidehiro Kawai1717f202015-12-14 11:19:09 +010073atomic_t panic_cpu = ATOMIC_INIT(PANIC_CPU_INVALID);
74
Linus Torvalds1da177e2005-04-16 15:20:36 -070075/**
76 * panic - halt the system
77 * @fmt: The text string to print
78 *
79 * Display a message, then perform cleanups.
80 *
81 * This function never returns.
82 */
Joe Perches9402c952012-01-12 17:17:17 -080083void panic(const char *fmt, ...)
Linus Torvalds1da177e2005-04-16 15:20:36 -070084{
Linus Torvalds1da177e2005-04-16 15:20:36 -070085 static char buf[1024];
86 va_list args;
TAMUKI Shoichic7ff0d92010-08-10 18:03:28 -070087 long i, i_next = 0;
88 int state = 0;
Hidehiro Kawai1717f202015-12-14 11:19:09 +010089 int old_cpu, this_cpu;
Linus Torvalds1da177e2005-04-16 15:20:36 -070090
Eric W. Biedermandc009d92005-06-25 14:57:52 -070091 /*
Vikram Mulukutla190320c2012-07-30 14:39:58 -070092 * Disable local interrupts. This will prevent panic_smp_self_stop
93 * from deadlocking the first cpu that invokes the panic, since
94 * there is nothing to prevent an interrupt handler (that runs
Hidehiro Kawai1717f202015-12-14 11:19:09 +010095 * after setting panic_cpu) from invoking panic() again.
Vikram Mulukutla190320c2012-07-30 14:39:58 -070096 */
97 local_irq_disable();
98
99 /*
Ingo Molnarc95dbf22009-03-13 11:14:06 +0100100 * It's possible to come here directly from a panic-assertion and
101 * not have preempt disabled. Some functions called from here want
Eric W. Biedermandc009d92005-06-25 14:57:52 -0700102 * preempt to be disabled. No point enabling it later though...
Michael Holzheu93e13a32012-01-12 17:20:18 -0800103 *
104 * Only one CPU is allowed to execute the panic code from here. For
105 * multiple parallel invocations of panic, all other CPUs either
106 * stop themself or will wait until they are stopped by the 1st CPU
107 * with smp_send_stop().
Hidehiro Kawai1717f202015-12-14 11:19:09 +0100108 *
109 * `old_cpu == PANIC_CPU_INVALID' means this is the 1st CPU which
110 * comes here, so go ahead.
111 * `old_cpu == this_cpu' means we came from nmi_panic() which sets
112 * panic_cpu to this CPU. In this case, this is also the 1st CPU.
Eric W. Biedermandc009d92005-06-25 14:57:52 -0700113 */
Hidehiro Kawai1717f202015-12-14 11:19:09 +0100114 this_cpu = raw_smp_processor_id();
115 old_cpu = atomic_cmpxchg(&panic_cpu, PANIC_CPU_INVALID, this_cpu);
116
117 if (old_cpu != PANIC_CPU_INVALID && old_cpu != this_cpu)
Michael Holzheu93e13a32012-01-12 17:20:18 -0800118 panic_smp_self_stop();
Eric W. Biedermandc009d92005-06-25 14:57:52 -0700119
Anton Blanchard5b530fc2010-05-26 14:44:24 -0700120 console_verbose();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700121 bust_spinlocks(1);
122 va_start(args, fmt);
123 vsnprintf(buf, sizeof(buf), fmt, args);
124 va_end(args);
Fabian Frederickd7c08472014-04-07 15:39:03 -0700125 pr_emerg("Kernel panic - not syncing: %s\n", buf);
Ingo Molnar5cb27302008-02-14 09:07:01 +0100126#ifdef CONFIG_DEBUG_BUGVERBOSE
Andi Kleen6e6f0a12012-01-12 17:20:30 -0800127 /*
128 * Avoid nested stack-dumping if a panic occurs during oops processing
129 */
Jason Wessel026ee1f2012-04-12 12:49:17 -0700130 if (!test_taint(TAINT_DIE) && oops_in_progress <= 1)
Andi Kleen6e6f0a12012-01-12 17:20:30 -0800131 dump_stack();
Ingo Molnar5cb27302008-02-14 09:07:01 +0100132#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700133
Eric W. Biedermandc009d92005-06-25 14:57:52 -0700134 /*
135 * If we have crashed and we have a crash kernel loaded let it handle
136 * everything else.
Masami Hiramatsuf06e5152014-06-06 14:37:07 -0700137 * If we want to run this after calling panic_notifiers, pass
138 * the "crash_kexec_post_notifiers" option to the kernel.
Hidehiro Kawai7bbee5c2015-12-14 11:19:11 +0100139 *
140 * Bypass the panic_cpu check and call __crash_kexec directly.
Eric W. Biedermandc009d92005-06-25 14:57:52 -0700141 */
Masami Hiramatsuf06e5152014-06-06 14:37:07 -0700142 if (!crash_kexec_post_notifiers)
Hidehiro Kawai7bbee5c2015-12-14 11:19:11 +0100143 __crash_kexec(NULL);
Eric W. Biedermandc009d92005-06-25 14:57:52 -0700144
Eric W. Biedermandc009d92005-06-25 14:57:52 -0700145 /*
146 * Note smp_send_stop is the usual smp shutdown function, which
147 * unfortunately means it may not be hardened to work in a panic
148 * situation.
149 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700150 smp_send_stop();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700151
Kees Cook67237342013-09-11 14:25:49 -0700152 /*
153 * Run any panic handlers, including those that might need to
154 * add information to the kmsg dump output.
155 */
Alan Sterne041c682006-03-27 01:16:30 -0800156 atomic_notifier_call_chain(&panic_notifier_list, 0, buf);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700157
Kees Cook67237342013-09-11 14:25:49 -0700158 kmsg_dump(KMSG_DUMP_PANIC);
159
Masami Hiramatsuf06e5152014-06-06 14:37:07 -0700160 /*
161 * If you doubt kdump always works fine in any situation,
162 * "crash_kexec_post_notifiers" offers you a chance to run
163 * panic_notifiers and dumping kmsg before kdump.
164 * Note: since some panic_notifiers can make crashed kernel
165 * more unstable, it can increase risks of the kdump failure too.
Hidehiro Kawai7bbee5c2015-12-14 11:19:11 +0100166 *
167 * Bypass the panic_cpu check and call __crash_kexec directly.
Masami Hiramatsuf06e5152014-06-06 14:37:07 -0700168 */
HATAYAMA Daisukef45d85f2015-06-30 14:57:43 -0700169 if (crash_kexec_post_notifiers)
Hidehiro Kawai7bbee5c2015-12-14 11:19:11 +0100170 __crash_kexec(NULL);
Masami Hiramatsuf06e5152014-06-06 14:37:07 -0700171
Aaro Koskinend014e8892009-10-02 14:41:20 +0300172 bust_spinlocks(0);
173
Vitaly Kuznetsov08d78652015-11-06 16:32:58 -0800174 /*
175 * We may have ended up stopping the CPU holding the lock (in
176 * smp_send_stop()) while still having some valuable data in the console
177 * buffer. Try to acquire the lock then release it regardless of the
Vitaly Kuznetsov7625b3a2015-11-20 15:57:24 -0800178 * result. The release will also print the buffers out. Locks debug
179 * should be disabled to avoid reporting bad unlock balance when
180 * panic() is not being callled from OOPS.
Vitaly Kuznetsov08d78652015-11-06 16:32:58 -0800181 */
Vitaly Kuznetsov7625b3a2015-11-20 15:57:24 -0800182 debug_locks_off();
Tejun Heo8d91f8b2016-01-15 16:58:24 -0800183 console_flush_on_panic();
Vitaly Kuznetsov08d78652015-11-06 16:32:58 -0800184
TAMUKI Shoichic7ff0d92010-08-10 18:03:28 -0700185 if (!panic_blink)
186 panic_blink = no_blink;
187
Eric W. Biedermandc009d92005-06-25 14:57:52 -0700188 if (panic_timeout > 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700189 /*
Ingo Molnarc95dbf22009-03-13 11:14:06 +0100190 * Delay timeout seconds before rebooting the machine.
191 * We can't use the "normal" timers since we just panicked.
192 */
Fabian Frederickd7c08472014-04-07 15:39:03 -0700193 pr_emerg("Rebooting in %d seconds..", panic_timeout);
Ingo Molnarc95dbf22009-03-13 11:14:06 +0100194
TAMUKI Shoichic7ff0d92010-08-10 18:03:28 -0700195 for (i = 0; i < panic_timeout * 1000; i += PANIC_TIMER_STEP) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700196 touch_nmi_watchdog();
TAMUKI Shoichic7ff0d92010-08-10 18:03:28 -0700197 if (i >= i_next) {
198 i += panic_blink(state ^= 1);
199 i_next = i + 3600 / PANIC_BLINK_SPD;
200 }
201 mdelay(PANIC_TIMER_STEP);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700202 }
Hugh Dickins4302fbc2011-07-26 16:08:52 -0700203 }
204 if (panic_timeout != 0) {
Ingo Molnarc95dbf22009-03-13 11:14:06 +0100205 /*
206 * This will not be a clean reboot, with everything
207 * shutting down. But if there is a chance of
208 * rebooting the system it will be rebooted.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700209 */
Eric W. Biederman2f048ea2005-07-26 11:49:23 -0600210 emergency_restart();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211 }
212#ifdef __sparc__
213 {
214 extern int stop_a_enabled;
Tom 'spot' Callawaya271c242005-04-24 20:38:02 -0700215 /* Make sure the user can actually press Stop-A (L1-A) */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700216 stop_a_enabled = 1;
Fabian Frederickd7c08472014-04-07 15:39:03 -0700217 pr_emerg("Press Stop-A (L1-A) to return to the boot prom\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218 }
219#endif
Martin Schwidefsky347a8dc2006-01-06 00:19:28 -0800220#if defined(CONFIG_S390)
Ingo Molnarc95dbf22009-03-13 11:14:06 +0100221 {
222 unsigned long caller;
223
224 caller = (unsigned long)__builtin_return_address(0);
225 disabled_wait(caller);
226 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700227#endif
Fabian Frederickd7c08472014-04-07 15:39:03 -0700228 pr_emerg("---[ end Kernel panic - not syncing: %s\n", buf);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700229 local_irq_enable();
TAMUKI Shoichic7ff0d92010-08-10 18:03:28 -0700230 for (i = 0; ; i += PANIC_TIMER_STEP) {
Jan Beulichc22db942006-02-10 01:51:11 -0800231 touch_softlockup_watchdog();
TAMUKI Shoichic7ff0d92010-08-10 18:03:28 -0700232 if (i >= i_next) {
233 i += panic_blink(state ^= 1);
234 i_next = i + 3600 / PANIC_BLINK_SPD;
235 }
236 mdelay(PANIC_TIMER_STEP);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700237 }
238}
239
240EXPORT_SYMBOL(panic);
241
Daniel Walkerc277e632007-10-18 03:06:08 -0700242
Andi Kleen25ddbb12008-10-15 22:01:41 -0700243struct tnt {
Ingo Molnarc95dbf22009-03-13 11:14:06 +0100244 u8 bit;
245 char true;
246 char false;
Andi Kleen25ddbb12008-10-15 22:01:41 -0700247};
248
249static const struct tnt tnts[] = {
Ingo Molnarc95dbf22009-03-13 11:14:06 +0100250 { TAINT_PROPRIETARY_MODULE, 'P', 'G' },
251 { TAINT_FORCED_MODULE, 'F', ' ' },
Dave Jones8c904872014-02-26 10:49:49 -0500252 { TAINT_CPU_OUT_OF_SPEC, 'S', ' ' },
Ingo Molnarc95dbf22009-03-13 11:14:06 +0100253 { TAINT_FORCED_RMMOD, 'R', ' ' },
254 { TAINT_MACHINE_CHECK, 'M', ' ' },
255 { TAINT_BAD_PAGE, 'B', ' ' },
256 { TAINT_USER, 'U', ' ' },
257 { TAINT_DIE, 'D', ' ' },
258 { TAINT_OVERRIDDEN_ACPI_TABLE, 'A', ' ' },
259 { TAINT_WARN, 'W', ' ' },
260 { TAINT_CRAP, 'C', ' ' },
Ben Hutchings92946bc2010-04-03 19:36:42 +0100261 { TAINT_FIRMWARE_WORKAROUND, 'I', ' ' },
Ben Hutchings2449b8b2011-10-24 15:12:28 +0200262 { TAINT_OOT_MODULE, 'O', ' ' },
Rusty Russell57673c22014-03-31 14:39:57 +1030263 { TAINT_UNSIGNED_MODULE, 'E', ' ' },
Josh Hunt69361ee2014-08-08 14:22:31 -0700264 { TAINT_SOFTLOCKUP, 'L', ' ' },
Seth Jenningsc5f45462014-12-16 11:58:18 -0600265 { TAINT_LIVEPATCH, 'K', ' ' },
Andi Kleen25ddbb12008-10-15 22:01:41 -0700266};
267
Linus Torvalds1da177e2005-04-16 15:20:36 -0700268/**
269 * print_tainted - return a string to represent the kernel taint state.
270 *
271 * 'P' - Proprietary module has been loaded.
272 * 'F' - Module has been forcibly loaded.
273 * 'S' - SMP with CPUs not designed for SMP.
274 * 'R' - User forced a module unload.
275 * 'M' - System experienced a machine check exception.
276 * 'B' - System has hit bad_page.
277 * 'U' - Userspace-defined naughtiness.
Arjan van de Vena8005992008-12-01 13:14:00 -0800278 * 'D' - Kernel has oopsed before
Linus Torvalds1da177e2005-04-16 15:20:36 -0700279 * 'A' - ACPI table overridden.
Theodore Ts'o34f5a392007-02-10 01:45:24 -0800280 * 'W' - Taint on warning.
Greg Kroah-Hartman061b1bd2008-09-24 14:46:44 -0700281 * 'C' - modules from drivers/staging are loaded.
Ben Hutchings92946bc2010-04-03 19:36:42 +0100282 * 'I' - Working around severe firmware bug.
Ben Hutchings2449b8b2011-10-24 15:12:28 +0200283 * 'O' - Out-of-tree module has been loaded.
Rusty Russell57673c22014-03-31 14:39:57 +1030284 * 'E' - Unsigned module has been loaded.
Xie XiuQibc53a3f2014-11-13 15:19:44 -0800285 * 'L' - A soft lockup has previously occurred.
Seth Jenningsc5f45462014-12-16 11:58:18 -0600286 * 'K' - Kernel has been live patched.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700287 *
Robert P. J. Dayfe002a42009-06-28 21:10:07 -0400288 * The string is overwritten by the next call to print_tainted().
Linus Torvalds1da177e2005-04-16 15:20:36 -0700289 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700290const char *print_tainted(void)
291{
Chen Gang01284762013-11-12 15:11:32 -0800292 static char buf[ARRAY_SIZE(tnts) + sizeof("Tainted: ")];
Andi Kleen25ddbb12008-10-15 22:01:41 -0700293
294 if (tainted_mask) {
295 char *s;
296 int i;
297
298 s = buf + sprintf(buf, "Tainted: ");
299 for (i = 0; i < ARRAY_SIZE(tnts); i++) {
300 const struct tnt *t = &tnts[i];
301 *s++ = test_bit(t->bit, &tainted_mask) ?
302 t->true : t->false;
303 }
304 *s = 0;
305 } else
Linus Torvalds1da177e2005-04-16 15:20:36 -0700306 snprintf(buf, sizeof(buf), "Not tainted");
Ingo Molnarc95dbf22009-03-13 11:14:06 +0100307
308 return buf;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700309}
310
Andi Kleen25ddbb12008-10-15 22:01:41 -0700311int test_taint(unsigned flag)
312{
313 return test_bit(flag, &tainted_mask);
314}
315EXPORT_SYMBOL(test_taint);
316
317unsigned long get_taint(void)
318{
319 return tainted_mask;
320}
321
Rusty Russell373d4d02013-01-21 17:17:39 +1030322/**
323 * add_taint: add a taint flag if not already set.
324 * @flag: one of the TAINT_* constants.
325 * @lockdep_ok: whether lock debugging is still OK.
326 *
327 * If something bad has gone wrong, you'll want @lockdebug_ok = false, but for
328 * some notewortht-but-not-corrupting cases, it can be set to true.
329 */
330void add_taint(unsigned flag, enum lockdep_ok lockdep_ok)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700331{
Rusty Russell373d4d02013-01-21 17:17:39 +1030332 if (lockdep_ok == LOCKDEP_NOW_UNRELIABLE && __debug_locks_off())
Fabian Frederickd7c08472014-04-07 15:39:03 -0700333 pr_warn("Disabling lock debugging due to kernel taint\n");
Frederic Weisbecker9eeba612009-04-11 03:17:17 +0200334
Andi Kleen25ddbb12008-10-15 22:01:41 -0700335 set_bit(flag, &tainted_mask);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700336}
337EXPORT_SYMBOL(add_taint);
Andrew Mortondd287792006-03-23 03:00:57 -0800338
Andrew Mortondd287792006-03-23 03:00:57 -0800339static void spin_msec(int msecs)
340{
341 int i;
342
343 for (i = 0; i < msecs; i++) {
344 touch_nmi_watchdog();
345 mdelay(1);
346 }
347}
348
349/*
350 * It just happens that oops_enter() and oops_exit() are identically
351 * implemented...
352 */
353static void do_oops_enter_exit(void)
354{
355 unsigned long flags;
356 static int spin_counter;
357
358 if (!pause_on_oops)
359 return;
360
361 spin_lock_irqsave(&pause_on_oops_lock, flags);
362 if (pause_on_oops_flag == 0) {
363 /* This CPU may now print the oops message */
364 pause_on_oops_flag = 1;
365 } else {
366 /* We need to stall this CPU */
367 if (!spin_counter) {
368 /* This CPU gets to do the counting */
369 spin_counter = pause_on_oops;
370 do {
371 spin_unlock(&pause_on_oops_lock);
372 spin_msec(MSEC_PER_SEC);
373 spin_lock(&pause_on_oops_lock);
374 } while (--spin_counter);
375 pause_on_oops_flag = 0;
376 } else {
377 /* This CPU waits for a different one */
378 while (spin_counter) {
379 spin_unlock(&pause_on_oops_lock);
380 spin_msec(1);
381 spin_lock(&pause_on_oops_lock);
382 }
383 }
384 }
385 spin_unlock_irqrestore(&pause_on_oops_lock, flags);
386}
387
388/*
Ingo Molnarc95dbf22009-03-13 11:14:06 +0100389 * Return true if the calling CPU is allowed to print oops-related info.
390 * This is a bit racy..
Andrew Mortondd287792006-03-23 03:00:57 -0800391 */
392int oops_may_print(void)
393{
394 return pause_on_oops_flag == 0;
395}
396
397/*
398 * Called when the architecture enters its oops handler, before it prints
Ingo Molnarc95dbf22009-03-13 11:14:06 +0100399 * anything. If this is the first CPU to oops, and it's oopsing the first
400 * time then let it proceed.
Andrew Mortondd287792006-03-23 03:00:57 -0800401 *
Ingo Molnarc95dbf22009-03-13 11:14:06 +0100402 * This is all enabled by the pause_on_oops kernel boot option. We do all
403 * this to ensure that oopses don't scroll off the screen. It has the
404 * side-effect of preventing later-oopsing CPUs from mucking up the display,
405 * too.
Andrew Mortondd287792006-03-23 03:00:57 -0800406 *
Ingo Molnarc95dbf22009-03-13 11:14:06 +0100407 * It turns out that the CPU which is allowed to print ends up pausing for
408 * the right duration, whereas all the other CPUs pause for twice as long:
409 * once in oops_enter(), once in oops_exit().
Andrew Mortondd287792006-03-23 03:00:57 -0800410 */
411void oops_enter(void)
412{
Thomas Gleixnerbdff7872009-07-24 15:30:45 -0400413 tracing_off();
Ingo Molnarc95dbf22009-03-13 11:14:06 +0100414 /* can't trust the integrity of the kernel anymore: */
415 debug_locks_off();
Andrew Mortondd287792006-03-23 03:00:57 -0800416 do_oops_enter_exit();
417}
418
419/*
Arjan van de Ven2c3b20e92007-12-20 15:01:17 +0100420 * 64-bit random ID for oopses:
421 */
422static u64 oops_id;
423
424static int init_oops_id(void)
425{
426 if (!oops_id)
427 get_random_bytes(&oops_id, sizeof(oops_id));
Arjan van de Vend6624f92009-01-06 14:40:54 -0800428 else
429 oops_id++;
Arjan van de Ven2c3b20e92007-12-20 15:01:17 +0100430
431 return 0;
432}
433late_initcall(init_oops_id);
434
Anton Blanchard863a6042010-08-10 18:03:30 -0700435void print_oops_end_marker(void)
Arjan van de Ven71c33912008-01-30 13:32:50 +0100436{
437 init_oops_id();
Fabian Frederickd7c08472014-04-07 15:39:03 -0700438 pr_warn("---[ end trace %016llx ]---\n", (unsigned long long)oops_id);
Arjan van de Ven71c33912008-01-30 13:32:50 +0100439}
440
Arjan van de Ven2c3b20e92007-12-20 15:01:17 +0100441/*
Andrew Mortondd287792006-03-23 03:00:57 -0800442 * Called when the architecture exits its oops handler, after printing
443 * everything.
444 */
445void oops_exit(void)
446{
447 do_oops_enter_exit();
Arjan van de Ven71c33912008-01-30 13:32:50 +0100448 print_oops_end_marker();
Simon Kagstrom456b5652009-10-16 14:09:18 +0200449 kmsg_dump(KMSG_DUMP_OOPS);
Andrew Mortondd287792006-03-23 03:00:57 -0800450}
Arjan van de Ven3162f752006-09-26 10:52:39 +0200451
Arjan van de Ven79b4cc52008-01-30 13:32:50 +0100452#ifdef WANT_WARN_ON_SLOWPATH
Linus Torvalds0f6f49a2009-05-16 13:41:28 -0700453struct slowpath_args {
454 const char *fmt;
Arjan van de Vena8f18b92008-07-25 01:45:53 -0700455 va_list args;
Linus Torvalds0f6f49a2009-05-16 13:41:28 -0700456};
457
Ben Hutchingsb2be0522010-04-03 19:34:56 +0100458static void warn_slowpath_common(const char *file, int line, void *caller,
459 unsigned taint, struct slowpath_args *args)
Linus Torvalds0f6f49a2009-05-16 13:41:28 -0700460{
Steven Rostedt (Red Hat)de7edd32013-06-14 16:21:43 -0400461 disable_trace_on_warning();
462
Alex Thorltondcb6b452013-07-08 16:00:42 -0700463 pr_warn("------------[ cut here ]------------\n");
464 pr_warn("WARNING: CPU: %d PID: %d at %s:%d %pS()\n",
465 raw_smp_processor_id(), current->pid, file, line, caller);
Arjan van de Ven74853db2008-11-28 08:35:25 -0800466
Linus Torvalds0f6f49a2009-05-16 13:41:28 -0700467 if (args)
468 vprintk(args->fmt, args->args);
Arjan van de Vena8f18b92008-07-25 01:45:53 -0700469
Prarit Bhargava9e3961a2014-12-10 15:45:50 -0800470 if (panic_on_warn) {
471 /*
472 * This thread may hit another WARN() in the panic path.
473 * Resetting this prevents additional WARN() from panicking the
474 * system on this thread. Other threads are blocked by the
475 * panic_mutex in panic().
476 */
477 panic_on_warn = 0;
478 panic("panic_on_warn set ...\n");
479 }
480
Arjan van de Vena8f18b92008-07-25 01:45:53 -0700481 print_modules();
482 dump_stack();
483 print_oops_end_marker();
Rusty Russell373d4d02013-01-21 17:17:39 +1030484 /* Just a warning, don't kill lockdep. */
485 add_taint(taint, LOCKDEP_STILL_OK);
Arjan van de Vena8f18b92008-07-25 01:45:53 -0700486}
Linus Torvalds0f6f49a2009-05-16 13:41:28 -0700487
488void warn_slowpath_fmt(const char *file, int line, const char *fmt, ...)
489{
490 struct slowpath_args args;
491
492 args.fmt = fmt;
493 va_start(args.args, fmt);
Ben Hutchingsb2be0522010-04-03 19:34:56 +0100494 warn_slowpath_common(file, line, __builtin_return_address(0),
495 TAINT_WARN, &args);
Linus Torvalds0f6f49a2009-05-16 13:41:28 -0700496 va_end(args.args);
497}
Andi Kleen57adc4d2009-05-06 16:02:53 -0700498EXPORT_SYMBOL(warn_slowpath_fmt);
499
Ben Hutchingsb2be0522010-04-03 19:34:56 +0100500void warn_slowpath_fmt_taint(const char *file, int line,
501 unsigned taint, const char *fmt, ...)
502{
503 struct slowpath_args args;
504
505 args.fmt = fmt;
506 va_start(args.args, fmt);
507 warn_slowpath_common(file, line, __builtin_return_address(0),
508 taint, &args);
509 va_end(args.args);
510}
511EXPORT_SYMBOL(warn_slowpath_fmt_taint);
512
Andi Kleen57adc4d2009-05-06 16:02:53 -0700513void warn_slowpath_null(const char *file, int line)
514{
Ben Hutchingsb2be0522010-04-03 19:34:56 +0100515 warn_slowpath_common(file, line, __builtin_return_address(0),
516 TAINT_WARN, NULL);
Andi Kleen57adc4d2009-05-06 16:02:53 -0700517}
518EXPORT_SYMBOL(warn_slowpath_null);
Arjan van de Ven79b4cc52008-01-30 13:32:50 +0100519#endif
520
Arjan van de Ven3162f752006-09-26 10:52:39 +0200521#ifdef CONFIG_CC_STACKPROTECTOR
Arjan van de Ven54371a42008-02-15 15:33:12 -0800522
Arjan van de Ven3162f752006-09-26 10:52:39 +0200523/*
524 * Called when gcc's -fstack-protector feature is used, and
525 * gcc detects corruption of the on-stack canary value
526 */
Andi Kleena7330c92014-02-08 08:52:06 +0100527__visible void __stack_chk_fail(void)
Arjan van de Ven3162f752006-09-26 10:52:39 +0200528{
Ingo Molnar517a92c2008-02-14 09:02:13 +0100529 panic("stack-protector: Kernel stack is corrupted in: %p\n",
530 __builtin_return_address(0));
Arjan van de Ven3162f752006-09-26 10:52:39 +0200531}
532EXPORT_SYMBOL(__stack_chk_fail);
Arjan van de Ven54371a42008-02-15 15:33:12 -0800533
Arjan van de Ven3162f752006-09-26 10:52:39 +0200534#endif
Rusty Russellf44dd162008-10-22 10:00:24 -0500535
536core_param(panic, panic_timeout, int, 0644);
537core_param(pause_on_oops, pause_on_oops, int, 0644);
Prarit Bhargava9e3961a2014-12-10 15:45:50 -0800538core_param(panic_on_warn, panic_on_warn, int, 0644);
Olaf Heringd404ab02011-03-22 16:34:04 -0700539
Masami Hiramatsuf06e5152014-06-06 14:37:07 -0700540static int __init setup_crash_kexec_post_notifiers(char *s)
541{
542 crash_kexec_post_notifiers = true;
543 return 0;
544}
545early_param("crash_kexec_post_notifiers", setup_crash_kexec_post_notifiers);
546
Olaf Heringd404ab02011-03-22 16:34:04 -0700547static int __init oops_setup(char *s)
548{
549 if (!s)
550 return -EINVAL;
551 if (!strcmp(s, "panic"))
552 panic_on_oops = 1;
553 return 0;
554}
555early_param("oops", oops_setup);