Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | */ |
Andrew Morton | 657b301 | 2006-08-13 23:24:19 -0700 | [diff] [blame] | 11 | #include <linux/debug_locks.h> |
Ingo Molnar | c95dbf2 | 2009-03-13 11:14:06 +0100 | [diff] [blame] | 12 | #include <linux/interrupt.h> |
Simon Kagstrom | 456b565 | 2009-10-16 14:09:18 +0200 | [diff] [blame] | 13 | #include <linux/kmsg_dump.h> |
Arjan van de Ven | 79b4cc5 | 2008-01-30 13:32:50 +0100 | [diff] [blame] | 14 | #include <linux/kallsyms.h> |
Ingo Molnar | c95dbf2 | 2009-03-13 11:14:06 +0100 | [diff] [blame] | 15 | #include <linux/notifier.h> |
| 16 | #include <linux/module.h> |
| 17 | #include <linux/random.h> |
Steven Rostedt (Red Hat) | de7edd3 | 2013-06-14 16:21:43 -0400 | [diff] [blame] | 18 | #include <linux/ftrace.h> |
Ingo Molnar | c95dbf2 | 2009-03-13 11:14:06 +0100 | [diff] [blame] | 19 | #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 Kuznetsov | 08d7865 | 2015-11-06 16:32:58 -0800 | [diff] [blame] | 26 | #include <linux/console.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 27 | |
TAMUKI Shoichi | c7ff0d9 | 2010-08-10 18:03:28 -0700 | [diff] [blame] | 28 | #define PANIC_TIMER_STEP 100 |
| 29 | #define PANIC_BLINK_SPD 18 |
| 30 | |
Kyle McMartin | 2a01bb3 | 2012-04-11 08:15:29 -0400 | [diff] [blame] | 31 | int panic_on_oops = CONFIG_PANIC_ON_OOPS_VALUE; |
Andi Kleen | 25ddbb1 | 2008-10-15 22:01:41 -0700 | [diff] [blame] | 32 | static unsigned long tainted_mask; |
Andrew Morton | dd28779 | 2006-03-23 03:00:57 -0800 | [diff] [blame] | 33 | static int pause_on_oops; |
| 34 | static int pause_on_oops_flag; |
| 35 | static DEFINE_SPINLOCK(pause_on_oops_lock); |
HATAYAMA Daisuke | 5375b70 | 2015-06-30 14:57:46 -0700 | [diff] [blame] | 36 | bool crash_kexec_post_notifiers; |
Prarit Bhargava | 9e3961a | 2014-12-10 15:45:50 -0800 | [diff] [blame] | 37 | int panic_on_warn __read_mostly; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 38 | |
Jason Baron | 5800dc3 | 2013-11-25 23:23:04 +0000 | [diff] [blame] | 39 | int panic_timeout = CONFIG_PANIC_TIMEOUT; |
Huang Ying | 81e88fd | 2011-01-12 14:44:55 +0800 | [diff] [blame] | 40 | EXPORT_SYMBOL_GPL(panic_timeout); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 41 | |
Alan Stern | e041c68 | 2006-03-27 01:16:30 -0800 | [diff] [blame] | 42 | ATOMIC_NOTIFIER_HEAD(panic_notifier_list); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 43 | |
| 44 | EXPORT_SYMBOL(panic_notifier_list); |
| 45 | |
TAMUKI Shoichi | c7ff0d9 | 2010-08-10 18:03:28 -0700 | [diff] [blame] | 46 | static long no_blink(int state) |
Anton Blanchard | 8aeee85 | 2010-03-05 13:42:55 -0800 | [diff] [blame] | 47 | { |
TAMUKI Shoichi | c7ff0d9 | 2010-08-10 18:03:28 -0700 | [diff] [blame] | 48 | return 0; |
Anton Blanchard | 8aeee85 | 2010-03-05 13:42:55 -0800 | [diff] [blame] | 49 | } |
| 50 | |
TAMUKI Shoichi | c7ff0d9 | 2010-08-10 18:03:28 -0700 | [diff] [blame] | 51 | /* Returns how long it waited in ms */ |
| 52 | long (*panic_blink)(int state); |
| 53 | EXPORT_SYMBOL(panic_blink); |
| 54 | |
Michael Holzheu | 93e13a3 | 2012-01-12 17:20:18 -0800 | [diff] [blame] | 55 | /* |
| 56 | * Stop ourself in panic -- architecture code may override this |
| 57 | */ |
| 58 | void __weak panic_smp_self_stop(void) |
| 59 | { |
| 60 | while (1) |
| 61 | cpu_relax(); |
| 62 | } |
| 63 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 64 | /** |
| 65 | * panic - halt the system |
| 66 | * @fmt: The text string to print |
| 67 | * |
| 68 | * Display a message, then perform cleanups. |
| 69 | * |
| 70 | * This function never returns. |
| 71 | */ |
Joe Perches | 9402c95 | 2012-01-12 17:17:17 -0800 | [diff] [blame] | 72 | void panic(const char *fmt, ...) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 73 | { |
Michael Holzheu | 93e13a3 | 2012-01-12 17:20:18 -0800 | [diff] [blame] | 74 | static DEFINE_SPINLOCK(panic_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 75 | static char buf[1024]; |
| 76 | va_list args; |
TAMUKI Shoichi | c7ff0d9 | 2010-08-10 18:03:28 -0700 | [diff] [blame] | 77 | long i, i_next = 0; |
| 78 | int state = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 79 | |
Eric W. Biederman | dc009d9 | 2005-06-25 14:57:52 -0700 | [diff] [blame] | 80 | /* |
Vikram Mulukutla | 190320c | 2012-07-30 14:39:58 -0700 | [diff] [blame] | 81 | * Disable local interrupts. This will prevent panic_smp_self_stop |
| 82 | * from deadlocking the first cpu that invokes the panic, since |
| 83 | * there is nothing to prevent an interrupt handler (that runs |
| 84 | * after the panic_lock is acquired) from invoking panic again. |
| 85 | */ |
| 86 | local_irq_disable(); |
| 87 | |
| 88 | /* |
Ingo Molnar | c95dbf2 | 2009-03-13 11:14:06 +0100 | [diff] [blame] | 89 | * It's possible to come here directly from a panic-assertion and |
| 90 | * not have preempt disabled. Some functions called from here want |
Eric W. Biederman | dc009d9 | 2005-06-25 14:57:52 -0700 | [diff] [blame] | 91 | * preempt to be disabled. No point enabling it later though... |
Michael Holzheu | 93e13a3 | 2012-01-12 17:20:18 -0800 | [diff] [blame] | 92 | * |
| 93 | * Only one CPU is allowed to execute the panic code from here. For |
| 94 | * multiple parallel invocations of panic, all other CPUs either |
| 95 | * stop themself or will wait until they are stopped by the 1st CPU |
| 96 | * with smp_send_stop(). |
Eric W. Biederman | dc009d9 | 2005-06-25 14:57:52 -0700 | [diff] [blame] | 97 | */ |
Michael Holzheu | 93e13a3 | 2012-01-12 17:20:18 -0800 | [diff] [blame] | 98 | if (!spin_trylock(&panic_lock)) |
| 99 | panic_smp_self_stop(); |
Eric W. Biederman | dc009d9 | 2005-06-25 14:57:52 -0700 | [diff] [blame] | 100 | |
Anton Blanchard | 5b530fc | 2010-05-26 14:44:24 -0700 | [diff] [blame] | 101 | console_verbose(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 102 | bust_spinlocks(1); |
| 103 | va_start(args, fmt); |
| 104 | vsnprintf(buf, sizeof(buf), fmt, args); |
| 105 | va_end(args); |
Fabian Frederick | d7c0847 | 2014-04-07 15:39:03 -0700 | [diff] [blame] | 106 | pr_emerg("Kernel panic - not syncing: %s\n", buf); |
Ingo Molnar | 5cb2730 | 2008-02-14 09:07:01 +0100 | [diff] [blame] | 107 | #ifdef CONFIG_DEBUG_BUGVERBOSE |
Andi Kleen | 6e6f0a1 | 2012-01-12 17:20:30 -0800 | [diff] [blame] | 108 | /* |
| 109 | * Avoid nested stack-dumping if a panic occurs during oops processing |
| 110 | */ |
Jason Wessel | 026ee1f | 2012-04-12 12:49:17 -0700 | [diff] [blame] | 111 | if (!test_taint(TAINT_DIE) && oops_in_progress <= 1) |
Andi Kleen | 6e6f0a1 | 2012-01-12 17:20:30 -0800 | [diff] [blame] | 112 | dump_stack(); |
Ingo Molnar | 5cb2730 | 2008-02-14 09:07:01 +0100 | [diff] [blame] | 113 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 114 | |
Eric W. Biederman | dc009d9 | 2005-06-25 14:57:52 -0700 | [diff] [blame] | 115 | /* |
| 116 | * If we have crashed and we have a crash kernel loaded let it handle |
| 117 | * everything else. |
Masami Hiramatsu | f06e515 | 2014-06-06 14:37:07 -0700 | [diff] [blame] | 118 | * If we want to run this after calling panic_notifiers, pass |
| 119 | * the "crash_kexec_post_notifiers" option to the kernel. |
Eric W. Biederman | dc009d9 | 2005-06-25 14:57:52 -0700 | [diff] [blame] | 120 | */ |
Masami Hiramatsu | f06e515 | 2014-06-06 14:37:07 -0700 | [diff] [blame] | 121 | if (!crash_kexec_post_notifiers) |
| 122 | crash_kexec(NULL); |
Eric W. Biederman | dc009d9 | 2005-06-25 14:57:52 -0700 | [diff] [blame] | 123 | |
Eric W. Biederman | dc009d9 | 2005-06-25 14:57:52 -0700 | [diff] [blame] | 124 | /* |
| 125 | * Note smp_send_stop is the usual smp shutdown function, which |
| 126 | * unfortunately means it may not be hardened to work in a panic |
| 127 | * situation. |
| 128 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 129 | smp_send_stop(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 130 | |
Kees Cook | 6723734 | 2013-09-11 14:25:49 -0700 | [diff] [blame] | 131 | /* |
| 132 | * Run any panic handlers, including those that might need to |
| 133 | * add information to the kmsg dump output. |
| 134 | */ |
Alan Stern | e041c68 | 2006-03-27 01:16:30 -0800 | [diff] [blame] | 135 | atomic_notifier_call_chain(&panic_notifier_list, 0, buf); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 136 | |
Kees Cook | 6723734 | 2013-09-11 14:25:49 -0700 | [diff] [blame] | 137 | kmsg_dump(KMSG_DUMP_PANIC); |
| 138 | |
Masami Hiramatsu | f06e515 | 2014-06-06 14:37:07 -0700 | [diff] [blame] | 139 | /* |
| 140 | * If you doubt kdump always works fine in any situation, |
| 141 | * "crash_kexec_post_notifiers" offers you a chance to run |
| 142 | * panic_notifiers and dumping kmsg before kdump. |
| 143 | * Note: since some panic_notifiers can make crashed kernel |
| 144 | * more unstable, it can increase risks of the kdump failure too. |
| 145 | */ |
HATAYAMA Daisuke | f45d85f | 2015-06-30 14:57:43 -0700 | [diff] [blame] | 146 | if (crash_kexec_post_notifiers) |
| 147 | crash_kexec(NULL); |
Masami Hiramatsu | f06e515 | 2014-06-06 14:37:07 -0700 | [diff] [blame] | 148 | |
Aaro Koskinen | d014e88 | 2009-10-02 14:41:20 +0300 | [diff] [blame] | 149 | bust_spinlocks(0); |
| 150 | |
Vitaly Kuznetsov | 08d7865 | 2015-11-06 16:32:58 -0800 | [diff] [blame] | 151 | /* |
| 152 | * We may have ended up stopping the CPU holding the lock (in |
| 153 | * smp_send_stop()) while still having some valuable data in the console |
| 154 | * buffer. Try to acquire the lock then release it regardless of the |
| 155 | * result. The release will also print the buffers out. |
| 156 | */ |
| 157 | console_trylock(); |
| 158 | console_unlock(); |
| 159 | |
TAMUKI Shoichi | c7ff0d9 | 2010-08-10 18:03:28 -0700 | [diff] [blame] | 160 | if (!panic_blink) |
| 161 | panic_blink = no_blink; |
| 162 | |
Eric W. Biederman | dc009d9 | 2005-06-25 14:57:52 -0700 | [diff] [blame] | 163 | if (panic_timeout > 0) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 164 | /* |
Ingo Molnar | c95dbf2 | 2009-03-13 11:14:06 +0100 | [diff] [blame] | 165 | * Delay timeout seconds before rebooting the machine. |
| 166 | * We can't use the "normal" timers since we just panicked. |
| 167 | */ |
Fabian Frederick | d7c0847 | 2014-04-07 15:39:03 -0700 | [diff] [blame] | 168 | pr_emerg("Rebooting in %d seconds..", panic_timeout); |
Ingo Molnar | c95dbf2 | 2009-03-13 11:14:06 +0100 | [diff] [blame] | 169 | |
TAMUKI Shoichi | c7ff0d9 | 2010-08-10 18:03:28 -0700 | [diff] [blame] | 170 | for (i = 0; i < panic_timeout * 1000; i += PANIC_TIMER_STEP) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 171 | touch_nmi_watchdog(); |
TAMUKI Shoichi | c7ff0d9 | 2010-08-10 18:03:28 -0700 | [diff] [blame] | 172 | if (i >= i_next) { |
| 173 | i += panic_blink(state ^= 1); |
| 174 | i_next = i + 3600 / PANIC_BLINK_SPD; |
| 175 | } |
| 176 | mdelay(PANIC_TIMER_STEP); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 177 | } |
Hugh Dickins | 4302fbc | 2011-07-26 16:08:52 -0700 | [diff] [blame] | 178 | } |
| 179 | if (panic_timeout != 0) { |
Ingo Molnar | c95dbf2 | 2009-03-13 11:14:06 +0100 | [diff] [blame] | 180 | /* |
| 181 | * This will not be a clean reboot, with everything |
| 182 | * shutting down. But if there is a chance of |
| 183 | * rebooting the system it will be rebooted. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 184 | */ |
Eric W. Biederman | 2f048ea | 2005-07-26 11:49:23 -0600 | [diff] [blame] | 185 | emergency_restart(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 186 | } |
| 187 | #ifdef __sparc__ |
| 188 | { |
| 189 | extern int stop_a_enabled; |
Tom 'spot' Callaway | a271c24 | 2005-04-24 20:38:02 -0700 | [diff] [blame] | 190 | /* Make sure the user can actually press Stop-A (L1-A) */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 191 | stop_a_enabled = 1; |
Fabian Frederick | d7c0847 | 2014-04-07 15:39:03 -0700 | [diff] [blame] | 192 | pr_emerg("Press Stop-A (L1-A) to return to the boot prom\n"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 193 | } |
| 194 | #endif |
Martin Schwidefsky | 347a8dc | 2006-01-06 00:19:28 -0800 | [diff] [blame] | 195 | #if defined(CONFIG_S390) |
Ingo Molnar | c95dbf2 | 2009-03-13 11:14:06 +0100 | [diff] [blame] | 196 | { |
| 197 | unsigned long caller; |
| 198 | |
| 199 | caller = (unsigned long)__builtin_return_address(0); |
| 200 | disabled_wait(caller); |
| 201 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 202 | #endif |
Fabian Frederick | d7c0847 | 2014-04-07 15:39:03 -0700 | [diff] [blame] | 203 | pr_emerg("---[ end Kernel panic - not syncing: %s\n", buf); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 204 | local_irq_enable(); |
TAMUKI Shoichi | c7ff0d9 | 2010-08-10 18:03:28 -0700 | [diff] [blame] | 205 | for (i = 0; ; i += PANIC_TIMER_STEP) { |
Jan Beulich | c22db94 | 2006-02-10 01:51:11 -0800 | [diff] [blame] | 206 | touch_softlockup_watchdog(); |
TAMUKI Shoichi | c7ff0d9 | 2010-08-10 18:03:28 -0700 | [diff] [blame] | 207 | if (i >= i_next) { |
| 208 | i += panic_blink(state ^= 1); |
| 209 | i_next = i + 3600 / PANIC_BLINK_SPD; |
| 210 | } |
| 211 | mdelay(PANIC_TIMER_STEP); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 212 | } |
| 213 | } |
| 214 | |
| 215 | EXPORT_SYMBOL(panic); |
| 216 | |
Daniel Walker | c277e63 | 2007-10-18 03:06:08 -0700 | [diff] [blame] | 217 | |
Andi Kleen | 25ddbb1 | 2008-10-15 22:01:41 -0700 | [diff] [blame] | 218 | struct tnt { |
Ingo Molnar | c95dbf2 | 2009-03-13 11:14:06 +0100 | [diff] [blame] | 219 | u8 bit; |
| 220 | char true; |
| 221 | char false; |
Andi Kleen | 25ddbb1 | 2008-10-15 22:01:41 -0700 | [diff] [blame] | 222 | }; |
| 223 | |
| 224 | static const struct tnt tnts[] = { |
Ingo Molnar | c95dbf2 | 2009-03-13 11:14:06 +0100 | [diff] [blame] | 225 | { TAINT_PROPRIETARY_MODULE, 'P', 'G' }, |
| 226 | { TAINT_FORCED_MODULE, 'F', ' ' }, |
Dave Jones | 8c90487 | 2014-02-26 10:49:49 -0500 | [diff] [blame] | 227 | { TAINT_CPU_OUT_OF_SPEC, 'S', ' ' }, |
Ingo Molnar | c95dbf2 | 2009-03-13 11:14:06 +0100 | [diff] [blame] | 228 | { TAINT_FORCED_RMMOD, 'R', ' ' }, |
| 229 | { TAINT_MACHINE_CHECK, 'M', ' ' }, |
| 230 | { TAINT_BAD_PAGE, 'B', ' ' }, |
| 231 | { TAINT_USER, 'U', ' ' }, |
| 232 | { TAINT_DIE, 'D', ' ' }, |
| 233 | { TAINT_OVERRIDDEN_ACPI_TABLE, 'A', ' ' }, |
| 234 | { TAINT_WARN, 'W', ' ' }, |
| 235 | { TAINT_CRAP, 'C', ' ' }, |
Ben Hutchings | 92946bc | 2010-04-03 19:36:42 +0100 | [diff] [blame] | 236 | { TAINT_FIRMWARE_WORKAROUND, 'I', ' ' }, |
Ben Hutchings | 2449b8b | 2011-10-24 15:12:28 +0200 | [diff] [blame] | 237 | { TAINT_OOT_MODULE, 'O', ' ' }, |
Rusty Russell | 57673c2 | 2014-03-31 14:39:57 +1030 | [diff] [blame] | 238 | { TAINT_UNSIGNED_MODULE, 'E', ' ' }, |
Josh Hunt | 69361ee | 2014-08-08 14:22:31 -0700 | [diff] [blame] | 239 | { TAINT_SOFTLOCKUP, 'L', ' ' }, |
Seth Jennings | c5f4546 | 2014-12-16 11:58:18 -0600 | [diff] [blame] | 240 | { TAINT_LIVEPATCH, 'K', ' ' }, |
Andi Kleen | 25ddbb1 | 2008-10-15 22:01:41 -0700 | [diff] [blame] | 241 | }; |
| 242 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 243 | /** |
| 244 | * print_tainted - return a string to represent the kernel taint state. |
| 245 | * |
| 246 | * 'P' - Proprietary module has been loaded. |
| 247 | * 'F' - Module has been forcibly loaded. |
| 248 | * 'S' - SMP with CPUs not designed for SMP. |
| 249 | * 'R' - User forced a module unload. |
| 250 | * 'M' - System experienced a machine check exception. |
| 251 | * 'B' - System has hit bad_page. |
| 252 | * 'U' - Userspace-defined naughtiness. |
Arjan van de Ven | a800599 | 2008-12-01 13:14:00 -0800 | [diff] [blame] | 253 | * 'D' - Kernel has oopsed before |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 254 | * 'A' - ACPI table overridden. |
Theodore Ts'o | 34f5a39 | 2007-02-10 01:45:24 -0800 | [diff] [blame] | 255 | * 'W' - Taint on warning. |
Greg Kroah-Hartman | 061b1bd | 2008-09-24 14:46:44 -0700 | [diff] [blame] | 256 | * 'C' - modules from drivers/staging are loaded. |
Ben Hutchings | 92946bc | 2010-04-03 19:36:42 +0100 | [diff] [blame] | 257 | * 'I' - Working around severe firmware bug. |
Ben Hutchings | 2449b8b | 2011-10-24 15:12:28 +0200 | [diff] [blame] | 258 | * 'O' - Out-of-tree module has been loaded. |
Rusty Russell | 57673c2 | 2014-03-31 14:39:57 +1030 | [diff] [blame] | 259 | * 'E' - Unsigned module has been loaded. |
Xie XiuQi | bc53a3f | 2014-11-13 15:19:44 -0800 | [diff] [blame] | 260 | * 'L' - A soft lockup has previously occurred. |
Seth Jennings | c5f4546 | 2014-12-16 11:58:18 -0600 | [diff] [blame] | 261 | * 'K' - Kernel has been live patched. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 262 | * |
Robert P. J. Day | fe002a4 | 2009-06-28 21:10:07 -0400 | [diff] [blame] | 263 | * The string is overwritten by the next call to print_tainted(). |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 264 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 265 | const char *print_tainted(void) |
| 266 | { |
Chen Gang | 0128476 | 2013-11-12 15:11:32 -0800 | [diff] [blame] | 267 | static char buf[ARRAY_SIZE(tnts) + sizeof("Tainted: ")]; |
Andi Kleen | 25ddbb1 | 2008-10-15 22:01:41 -0700 | [diff] [blame] | 268 | |
| 269 | if (tainted_mask) { |
| 270 | char *s; |
| 271 | int i; |
| 272 | |
| 273 | s = buf + sprintf(buf, "Tainted: "); |
| 274 | for (i = 0; i < ARRAY_SIZE(tnts); i++) { |
| 275 | const struct tnt *t = &tnts[i]; |
| 276 | *s++ = test_bit(t->bit, &tainted_mask) ? |
| 277 | t->true : t->false; |
| 278 | } |
| 279 | *s = 0; |
| 280 | } else |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 281 | snprintf(buf, sizeof(buf), "Not tainted"); |
Ingo Molnar | c95dbf2 | 2009-03-13 11:14:06 +0100 | [diff] [blame] | 282 | |
| 283 | return buf; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 284 | } |
| 285 | |
Andi Kleen | 25ddbb1 | 2008-10-15 22:01:41 -0700 | [diff] [blame] | 286 | int test_taint(unsigned flag) |
| 287 | { |
| 288 | return test_bit(flag, &tainted_mask); |
| 289 | } |
| 290 | EXPORT_SYMBOL(test_taint); |
| 291 | |
| 292 | unsigned long get_taint(void) |
| 293 | { |
| 294 | return tainted_mask; |
| 295 | } |
| 296 | |
Rusty Russell | 373d4d0 | 2013-01-21 17:17:39 +1030 | [diff] [blame] | 297 | /** |
| 298 | * add_taint: add a taint flag if not already set. |
| 299 | * @flag: one of the TAINT_* constants. |
| 300 | * @lockdep_ok: whether lock debugging is still OK. |
| 301 | * |
| 302 | * If something bad has gone wrong, you'll want @lockdebug_ok = false, but for |
| 303 | * some notewortht-but-not-corrupting cases, it can be set to true. |
| 304 | */ |
| 305 | void add_taint(unsigned flag, enum lockdep_ok lockdep_ok) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 306 | { |
Rusty Russell | 373d4d0 | 2013-01-21 17:17:39 +1030 | [diff] [blame] | 307 | if (lockdep_ok == LOCKDEP_NOW_UNRELIABLE && __debug_locks_off()) |
Fabian Frederick | d7c0847 | 2014-04-07 15:39:03 -0700 | [diff] [blame] | 308 | pr_warn("Disabling lock debugging due to kernel taint\n"); |
Frederic Weisbecker | 9eeba61 | 2009-04-11 03:17:17 +0200 | [diff] [blame] | 309 | |
Andi Kleen | 25ddbb1 | 2008-10-15 22:01:41 -0700 | [diff] [blame] | 310 | set_bit(flag, &tainted_mask); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 311 | } |
| 312 | EXPORT_SYMBOL(add_taint); |
Andrew Morton | dd28779 | 2006-03-23 03:00:57 -0800 | [diff] [blame] | 313 | |
Andrew Morton | dd28779 | 2006-03-23 03:00:57 -0800 | [diff] [blame] | 314 | static void spin_msec(int msecs) |
| 315 | { |
| 316 | int i; |
| 317 | |
| 318 | for (i = 0; i < msecs; i++) { |
| 319 | touch_nmi_watchdog(); |
| 320 | mdelay(1); |
| 321 | } |
| 322 | } |
| 323 | |
| 324 | /* |
| 325 | * It just happens that oops_enter() and oops_exit() are identically |
| 326 | * implemented... |
| 327 | */ |
| 328 | static void do_oops_enter_exit(void) |
| 329 | { |
| 330 | unsigned long flags; |
| 331 | static int spin_counter; |
| 332 | |
| 333 | if (!pause_on_oops) |
| 334 | return; |
| 335 | |
| 336 | spin_lock_irqsave(&pause_on_oops_lock, flags); |
| 337 | if (pause_on_oops_flag == 0) { |
| 338 | /* This CPU may now print the oops message */ |
| 339 | pause_on_oops_flag = 1; |
| 340 | } else { |
| 341 | /* We need to stall this CPU */ |
| 342 | if (!spin_counter) { |
| 343 | /* This CPU gets to do the counting */ |
| 344 | spin_counter = pause_on_oops; |
| 345 | do { |
| 346 | spin_unlock(&pause_on_oops_lock); |
| 347 | spin_msec(MSEC_PER_SEC); |
| 348 | spin_lock(&pause_on_oops_lock); |
| 349 | } while (--spin_counter); |
| 350 | pause_on_oops_flag = 0; |
| 351 | } else { |
| 352 | /* This CPU waits for a different one */ |
| 353 | while (spin_counter) { |
| 354 | spin_unlock(&pause_on_oops_lock); |
| 355 | spin_msec(1); |
| 356 | spin_lock(&pause_on_oops_lock); |
| 357 | } |
| 358 | } |
| 359 | } |
| 360 | spin_unlock_irqrestore(&pause_on_oops_lock, flags); |
| 361 | } |
| 362 | |
| 363 | /* |
Ingo Molnar | c95dbf2 | 2009-03-13 11:14:06 +0100 | [diff] [blame] | 364 | * Return true if the calling CPU is allowed to print oops-related info. |
| 365 | * This is a bit racy.. |
Andrew Morton | dd28779 | 2006-03-23 03:00:57 -0800 | [diff] [blame] | 366 | */ |
| 367 | int oops_may_print(void) |
| 368 | { |
| 369 | return pause_on_oops_flag == 0; |
| 370 | } |
| 371 | |
| 372 | /* |
| 373 | * Called when the architecture enters its oops handler, before it prints |
Ingo Molnar | c95dbf2 | 2009-03-13 11:14:06 +0100 | [diff] [blame] | 374 | * anything. If this is the first CPU to oops, and it's oopsing the first |
| 375 | * time then let it proceed. |
Andrew Morton | dd28779 | 2006-03-23 03:00:57 -0800 | [diff] [blame] | 376 | * |
Ingo Molnar | c95dbf2 | 2009-03-13 11:14:06 +0100 | [diff] [blame] | 377 | * This is all enabled by the pause_on_oops kernel boot option. We do all |
| 378 | * this to ensure that oopses don't scroll off the screen. It has the |
| 379 | * side-effect of preventing later-oopsing CPUs from mucking up the display, |
| 380 | * too. |
Andrew Morton | dd28779 | 2006-03-23 03:00:57 -0800 | [diff] [blame] | 381 | * |
Ingo Molnar | c95dbf2 | 2009-03-13 11:14:06 +0100 | [diff] [blame] | 382 | * It turns out that the CPU which is allowed to print ends up pausing for |
| 383 | * the right duration, whereas all the other CPUs pause for twice as long: |
| 384 | * once in oops_enter(), once in oops_exit(). |
Andrew Morton | dd28779 | 2006-03-23 03:00:57 -0800 | [diff] [blame] | 385 | */ |
| 386 | void oops_enter(void) |
| 387 | { |
Thomas Gleixner | bdff787 | 2009-07-24 15:30:45 -0400 | [diff] [blame] | 388 | tracing_off(); |
Ingo Molnar | c95dbf2 | 2009-03-13 11:14:06 +0100 | [diff] [blame] | 389 | /* can't trust the integrity of the kernel anymore: */ |
| 390 | debug_locks_off(); |
Andrew Morton | dd28779 | 2006-03-23 03:00:57 -0800 | [diff] [blame] | 391 | do_oops_enter_exit(); |
| 392 | } |
| 393 | |
| 394 | /* |
Arjan van de Ven | 2c3b20e9 | 2007-12-20 15:01:17 +0100 | [diff] [blame] | 395 | * 64-bit random ID for oopses: |
| 396 | */ |
| 397 | static u64 oops_id; |
| 398 | |
| 399 | static int init_oops_id(void) |
| 400 | { |
| 401 | if (!oops_id) |
| 402 | get_random_bytes(&oops_id, sizeof(oops_id)); |
Arjan van de Ven | d6624f9 | 2009-01-06 14:40:54 -0800 | [diff] [blame] | 403 | else |
| 404 | oops_id++; |
Arjan van de Ven | 2c3b20e9 | 2007-12-20 15:01:17 +0100 | [diff] [blame] | 405 | |
| 406 | return 0; |
| 407 | } |
| 408 | late_initcall(init_oops_id); |
| 409 | |
Anton Blanchard | 863a604 | 2010-08-10 18:03:30 -0700 | [diff] [blame] | 410 | void print_oops_end_marker(void) |
Arjan van de Ven | 71c3391 | 2008-01-30 13:32:50 +0100 | [diff] [blame] | 411 | { |
| 412 | init_oops_id(); |
Fabian Frederick | d7c0847 | 2014-04-07 15:39:03 -0700 | [diff] [blame] | 413 | pr_warn("---[ end trace %016llx ]---\n", (unsigned long long)oops_id); |
Arjan van de Ven | 71c3391 | 2008-01-30 13:32:50 +0100 | [diff] [blame] | 414 | } |
| 415 | |
Arjan van de Ven | 2c3b20e9 | 2007-12-20 15:01:17 +0100 | [diff] [blame] | 416 | /* |
Andrew Morton | dd28779 | 2006-03-23 03:00:57 -0800 | [diff] [blame] | 417 | * Called when the architecture exits its oops handler, after printing |
| 418 | * everything. |
| 419 | */ |
| 420 | void oops_exit(void) |
| 421 | { |
| 422 | do_oops_enter_exit(); |
Arjan van de Ven | 71c3391 | 2008-01-30 13:32:50 +0100 | [diff] [blame] | 423 | print_oops_end_marker(); |
Simon Kagstrom | 456b565 | 2009-10-16 14:09:18 +0200 | [diff] [blame] | 424 | kmsg_dump(KMSG_DUMP_OOPS); |
Andrew Morton | dd28779 | 2006-03-23 03:00:57 -0800 | [diff] [blame] | 425 | } |
Arjan van de Ven | 3162f75 | 2006-09-26 10:52:39 +0200 | [diff] [blame] | 426 | |
Arjan van de Ven | 79b4cc5 | 2008-01-30 13:32:50 +0100 | [diff] [blame] | 427 | #ifdef WANT_WARN_ON_SLOWPATH |
Linus Torvalds | 0f6f49a | 2009-05-16 13:41:28 -0700 | [diff] [blame] | 428 | struct slowpath_args { |
| 429 | const char *fmt; |
Arjan van de Ven | a8f18b9 | 2008-07-25 01:45:53 -0700 | [diff] [blame] | 430 | va_list args; |
Linus Torvalds | 0f6f49a | 2009-05-16 13:41:28 -0700 | [diff] [blame] | 431 | }; |
| 432 | |
Ben Hutchings | b2be052 | 2010-04-03 19:34:56 +0100 | [diff] [blame] | 433 | static void warn_slowpath_common(const char *file, int line, void *caller, |
| 434 | unsigned taint, struct slowpath_args *args) |
Linus Torvalds | 0f6f49a | 2009-05-16 13:41:28 -0700 | [diff] [blame] | 435 | { |
Steven Rostedt (Red Hat) | de7edd3 | 2013-06-14 16:21:43 -0400 | [diff] [blame] | 436 | disable_trace_on_warning(); |
| 437 | |
Alex Thorlton | dcb6b45 | 2013-07-08 16:00:42 -0700 | [diff] [blame] | 438 | pr_warn("------------[ cut here ]------------\n"); |
| 439 | pr_warn("WARNING: CPU: %d PID: %d at %s:%d %pS()\n", |
| 440 | raw_smp_processor_id(), current->pid, file, line, caller); |
Arjan van de Ven | 74853db | 2008-11-28 08:35:25 -0800 | [diff] [blame] | 441 | |
Linus Torvalds | 0f6f49a | 2009-05-16 13:41:28 -0700 | [diff] [blame] | 442 | if (args) |
| 443 | vprintk(args->fmt, args->args); |
Arjan van de Ven | a8f18b9 | 2008-07-25 01:45:53 -0700 | [diff] [blame] | 444 | |
Prarit Bhargava | 9e3961a | 2014-12-10 15:45:50 -0800 | [diff] [blame] | 445 | if (panic_on_warn) { |
| 446 | /* |
| 447 | * This thread may hit another WARN() in the panic path. |
| 448 | * Resetting this prevents additional WARN() from panicking the |
| 449 | * system on this thread. Other threads are blocked by the |
| 450 | * panic_mutex in panic(). |
| 451 | */ |
| 452 | panic_on_warn = 0; |
| 453 | panic("panic_on_warn set ...\n"); |
| 454 | } |
| 455 | |
Arjan van de Ven | a8f18b9 | 2008-07-25 01:45:53 -0700 | [diff] [blame] | 456 | print_modules(); |
| 457 | dump_stack(); |
| 458 | print_oops_end_marker(); |
Rusty Russell | 373d4d0 | 2013-01-21 17:17:39 +1030 | [diff] [blame] | 459 | /* Just a warning, don't kill lockdep. */ |
| 460 | add_taint(taint, LOCKDEP_STILL_OK); |
Arjan van de Ven | a8f18b9 | 2008-07-25 01:45:53 -0700 | [diff] [blame] | 461 | } |
Linus Torvalds | 0f6f49a | 2009-05-16 13:41:28 -0700 | [diff] [blame] | 462 | |
| 463 | void warn_slowpath_fmt(const char *file, int line, const char *fmt, ...) |
| 464 | { |
| 465 | struct slowpath_args args; |
| 466 | |
| 467 | args.fmt = fmt; |
| 468 | va_start(args.args, fmt); |
Ben Hutchings | b2be052 | 2010-04-03 19:34:56 +0100 | [diff] [blame] | 469 | warn_slowpath_common(file, line, __builtin_return_address(0), |
| 470 | TAINT_WARN, &args); |
Linus Torvalds | 0f6f49a | 2009-05-16 13:41:28 -0700 | [diff] [blame] | 471 | va_end(args.args); |
| 472 | } |
Andi Kleen | 57adc4d | 2009-05-06 16:02:53 -0700 | [diff] [blame] | 473 | EXPORT_SYMBOL(warn_slowpath_fmt); |
| 474 | |
Ben Hutchings | b2be052 | 2010-04-03 19:34:56 +0100 | [diff] [blame] | 475 | void warn_slowpath_fmt_taint(const char *file, int line, |
| 476 | unsigned taint, const char *fmt, ...) |
| 477 | { |
| 478 | struct slowpath_args args; |
| 479 | |
| 480 | args.fmt = fmt; |
| 481 | va_start(args.args, fmt); |
| 482 | warn_slowpath_common(file, line, __builtin_return_address(0), |
| 483 | taint, &args); |
| 484 | va_end(args.args); |
| 485 | } |
| 486 | EXPORT_SYMBOL(warn_slowpath_fmt_taint); |
| 487 | |
Andi Kleen | 57adc4d | 2009-05-06 16:02:53 -0700 | [diff] [blame] | 488 | void warn_slowpath_null(const char *file, int line) |
| 489 | { |
Ben Hutchings | b2be052 | 2010-04-03 19:34:56 +0100 | [diff] [blame] | 490 | warn_slowpath_common(file, line, __builtin_return_address(0), |
| 491 | TAINT_WARN, NULL); |
Andi Kleen | 57adc4d | 2009-05-06 16:02:53 -0700 | [diff] [blame] | 492 | } |
| 493 | EXPORT_SYMBOL(warn_slowpath_null); |
Arjan van de Ven | 79b4cc5 | 2008-01-30 13:32:50 +0100 | [diff] [blame] | 494 | #endif |
| 495 | |
Arjan van de Ven | 3162f75 | 2006-09-26 10:52:39 +0200 | [diff] [blame] | 496 | #ifdef CONFIG_CC_STACKPROTECTOR |
Arjan van de Ven | 54371a4 | 2008-02-15 15:33:12 -0800 | [diff] [blame] | 497 | |
Arjan van de Ven | 3162f75 | 2006-09-26 10:52:39 +0200 | [diff] [blame] | 498 | /* |
| 499 | * Called when gcc's -fstack-protector feature is used, and |
| 500 | * gcc detects corruption of the on-stack canary value |
| 501 | */ |
Andi Kleen | a7330c9 | 2014-02-08 08:52:06 +0100 | [diff] [blame] | 502 | __visible void __stack_chk_fail(void) |
Arjan van de Ven | 3162f75 | 2006-09-26 10:52:39 +0200 | [diff] [blame] | 503 | { |
Ingo Molnar | 517a92c | 2008-02-14 09:02:13 +0100 | [diff] [blame] | 504 | panic("stack-protector: Kernel stack is corrupted in: %p\n", |
| 505 | __builtin_return_address(0)); |
Arjan van de Ven | 3162f75 | 2006-09-26 10:52:39 +0200 | [diff] [blame] | 506 | } |
| 507 | EXPORT_SYMBOL(__stack_chk_fail); |
Arjan van de Ven | 54371a4 | 2008-02-15 15:33:12 -0800 | [diff] [blame] | 508 | |
Arjan van de Ven | 3162f75 | 2006-09-26 10:52:39 +0200 | [diff] [blame] | 509 | #endif |
Rusty Russell | f44dd16 | 2008-10-22 10:00:24 -0500 | [diff] [blame] | 510 | |
| 511 | core_param(panic, panic_timeout, int, 0644); |
| 512 | core_param(pause_on_oops, pause_on_oops, int, 0644); |
Prarit Bhargava | 9e3961a | 2014-12-10 15:45:50 -0800 | [diff] [blame] | 513 | core_param(panic_on_warn, panic_on_warn, int, 0644); |
Olaf Hering | d404ab0 | 2011-03-22 16:34:04 -0700 | [diff] [blame] | 514 | |
Masami Hiramatsu | f06e515 | 2014-06-06 14:37:07 -0700 | [diff] [blame] | 515 | static int __init setup_crash_kexec_post_notifiers(char *s) |
| 516 | { |
| 517 | crash_kexec_post_notifiers = true; |
| 518 | return 0; |
| 519 | } |
| 520 | early_param("crash_kexec_post_notifiers", setup_crash_kexec_post_notifiers); |
| 521 | |
Olaf Hering | d404ab0 | 2011-03-22 16:34:04 -0700 | [diff] [blame] | 522 | static int __init oops_setup(char *s) |
| 523 | { |
| 524 | if (!s) |
| 525 | return -EINVAL; |
| 526 | if (!strcmp(s, "panic")) |
| 527 | panic_on_oops = 1; |
| 528 | return 0; |
| 529 | } |
| 530 | early_param("oops", oops_setup); |