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> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 26 | |
TAMUKI Shoichi | c7ff0d9 | 2010-08-10 18:03:28 -0700 | [diff] [blame] | 27 | #define PANIC_TIMER_STEP 100 |
| 28 | #define PANIC_BLINK_SPD 18 |
| 29 | |
Kyle McMartin | 2a01bb3 | 2012-04-11 08:15:29 -0400 | [diff] [blame] | 30 | int panic_on_oops = CONFIG_PANIC_ON_OOPS_VALUE; |
Andi Kleen | 25ddbb1 | 2008-10-15 22:01:41 -0700 | [diff] [blame] | 31 | static unsigned long tainted_mask; |
Andrew Morton | dd28779 | 2006-03-23 03:00:57 -0800 | [diff] [blame] | 32 | static int pause_on_oops; |
| 33 | static int pause_on_oops_flag; |
| 34 | static DEFINE_SPINLOCK(pause_on_oops_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 35 | |
Jason Baron | 5800dc3 | 2013-11-25 23:23:04 +0000 | [diff] [blame] | 36 | int panic_timeout = CONFIG_PANIC_TIMEOUT; |
Huang Ying | 81e88fd | 2011-01-12 14:44:55 +0800 | [diff] [blame] | 37 | EXPORT_SYMBOL_GPL(panic_timeout); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 38 | |
Alan Stern | e041c68 | 2006-03-27 01:16:30 -0800 | [diff] [blame] | 39 | ATOMIC_NOTIFIER_HEAD(panic_notifier_list); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 40 | |
| 41 | EXPORT_SYMBOL(panic_notifier_list); |
| 42 | |
TAMUKI Shoichi | c7ff0d9 | 2010-08-10 18:03:28 -0700 | [diff] [blame] | 43 | static long no_blink(int state) |
Anton Blanchard | 8aeee85 | 2010-03-05 13:42:55 -0800 | [diff] [blame] | 44 | { |
TAMUKI Shoichi | c7ff0d9 | 2010-08-10 18:03:28 -0700 | [diff] [blame] | 45 | return 0; |
Anton Blanchard | 8aeee85 | 2010-03-05 13:42:55 -0800 | [diff] [blame] | 46 | } |
| 47 | |
TAMUKI Shoichi | c7ff0d9 | 2010-08-10 18:03:28 -0700 | [diff] [blame] | 48 | /* Returns how long it waited in ms */ |
| 49 | long (*panic_blink)(int state); |
| 50 | EXPORT_SYMBOL(panic_blink); |
| 51 | |
Michael Holzheu | 93e13a3 | 2012-01-12 17:20:18 -0800 | [diff] [blame] | 52 | /* |
| 53 | * Stop ourself in panic -- architecture code may override this |
| 54 | */ |
| 55 | void __weak panic_smp_self_stop(void) |
| 56 | { |
| 57 | while (1) |
| 58 | cpu_relax(); |
| 59 | } |
| 60 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 61 | /** |
| 62 | * panic - halt the system |
| 63 | * @fmt: The text string to print |
| 64 | * |
| 65 | * Display a message, then perform cleanups. |
| 66 | * |
| 67 | * This function never returns. |
| 68 | */ |
Joe Perches | 9402c95 | 2012-01-12 17:17:17 -0800 | [diff] [blame] | 69 | void panic(const char *fmt, ...) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 70 | { |
Michael Holzheu | 93e13a3 | 2012-01-12 17:20:18 -0800 | [diff] [blame] | 71 | static DEFINE_SPINLOCK(panic_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 72 | static char buf[1024]; |
| 73 | va_list args; |
TAMUKI Shoichi | c7ff0d9 | 2010-08-10 18:03:28 -0700 | [diff] [blame] | 74 | long i, i_next = 0; |
| 75 | int state = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 76 | |
Eric W. Biederman | dc009d9 | 2005-06-25 14:57:52 -0700 | [diff] [blame] | 77 | /* |
Vikram Mulukutla | 190320c | 2012-07-30 14:39:58 -0700 | [diff] [blame] | 78 | * Disable local interrupts. This will prevent panic_smp_self_stop |
| 79 | * from deadlocking the first cpu that invokes the panic, since |
| 80 | * there is nothing to prevent an interrupt handler (that runs |
| 81 | * after the panic_lock is acquired) from invoking panic again. |
| 82 | */ |
| 83 | local_irq_disable(); |
| 84 | |
| 85 | /* |
Ingo Molnar | c95dbf2 | 2009-03-13 11:14:06 +0100 | [diff] [blame] | 86 | * It's possible to come here directly from a panic-assertion and |
| 87 | * not have preempt disabled. Some functions called from here want |
Eric W. Biederman | dc009d9 | 2005-06-25 14:57:52 -0700 | [diff] [blame] | 88 | * preempt to be disabled. No point enabling it later though... |
Michael Holzheu | 93e13a3 | 2012-01-12 17:20:18 -0800 | [diff] [blame] | 89 | * |
| 90 | * Only one CPU is allowed to execute the panic code from here. For |
| 91 | * multiple parallel invocations of panic, all other CPUs either |
| 92 | * stop themself or will wait until they are stopped by the 1st CPU |
| 93 | * with smp_send_stop(). |
Eric W. Biederman | dc009d9 | 2005-06-25 14:57:52 -0700 | [diff] [blame] | 94 | */ |
Michael Holzheu | 93e13a3 | 2012-01-12 17:20:18 -0800 | [diff] [blame] | 95 | if (!spin_trylock(&panic_lock)) |
| 96 | panic_smp_self_stop(); |
Eric W. Biederman | dc009d9 | 2005-06-25 14:57:52 -0700 | [diff] [blame] | 97 | |
Anton Blanchard | 5b530fc | 2010-05-26 14:44:24 -0700 | [diff] [blame] | 98 | console_verbose(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 99 | bust_spinlocks(1); |
| 100 | va_start(args, fmt); |
| 101 | vsnprintf(buf, sizeof(buf), fmt, args); |
| 102 | va_end(args); |
| 103 | printk(KERN_EMERG "Kernel panic - not syncing: %s\n",buf); |
Ingo Molnar | 5cb2730 | 2008-02-14 09:07:01 +0100 | [diff] [blame] | 104 | #ifdef CONFIG_DEBUG_BUGVERBOSE |
Andi Kleen | 6e6f0a1 | 2012-01-12 17:20:30 -0800 | [diff] [blame] | 105 | /* |
| 106 | * Avoid nested stack-dumping if a panic occurs during oops processing |
| 107 | */ |
Jason Wessel | 026ee1f | 2012-04-12 12:49:17 -0700 | [diff] [blame] | 108 | if (!test_taint(TAINT_DIE) && oops_in_progress <= 1) |
Andi Kleen | 6e6f0a1 | 2012-01-12 17:20:30 -0800 | [diff] [blame] | 109 | dump_stack(); |
Ingo Molnar | 5cb2730 | 2008-02-14 09:07:01 +0100 | [diff] [blame] | 110 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 111 | |
Eric W. Biederman | dc009d9 | 2005-06-25 14:57:52 -0700 | [diff] [blame] | 112 | /* |
| 113 | * If we have crashed and we have a crash kernel loaded let it handle |
| 114 | * everything else. |
| 115 | * Do we want to call this before we try to display a message? |
| 116 | */ |
Alexander Nyberg | 6e274d1 | 2005-06-25 14:58:26 -0700 | [diff] [blame] | 117 | crash_kexec(NULL); |
Eric W. Biederman | dc009d9 | 2005-06-25 14:57:52 -0700 | [diff] [blame] | 118 | |
Eric W. Biederman | dc009d9 | 2005-06-25 14:57:52 -0700 | [diff] [blame] | 119 | /* |
| 120 | * Note smp_send_stop is the usual smp shutdown function, which |
| 121 | * unfortunately means it may not be hardened to work in a panic |
| 122 | * situation. |
| 123 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 124 | smp_send_stop(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 125 | |
Kees Cook | 6723734 | 2013-09-11 14:25:49 -0700 | [diff] [blame] | 126 | /* |
| 127 | * Run any panic handlers, including those that might need to |
| 128 | * add information to the kmsg dump output. |
| 129 | */ |
Alan Stern | e041c68 | 2006-03-27 01:16:30 -0800 | [diff] [blame] | 130 | atomic_notifier_call_chain(&panic_notifier_list, 0, buf); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 131 | |
Kees Cook | 6723734 | 2013-09-11 14:25:49 -0700 | [diff] [blame] | 132 | kmsg_dump(KMSG_DUMP_PANIC); |
| 133 | |
Aaro Koskinen | d014e88 | 2009-10-02 14:41:20 +0300 | [diff] [blame] | 134 | bust_spinlocks(0); |
| 135 | |
TAMUKI Shoichi | c7ff0d9 | 2010-08-10 18:03:28 -0700 | [diff] [blame] | 136 | if (!panic_blink) |
| 137 | panic_blink = no_blink; |
| 138 | |
Eric W. Biederman | dc009d9 | 2005-06-25 14:57:52 -0700 | [diff] [blame] | 139 | if (panic_timeout > 0) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 140 | /* |
Ingo Molnar | c95dbf2 | 2009-03-13 11:14:06 +0100 | [diff] [blame] | 141 | * Delay timeout seconds before rebooting the machine. |
| 142 | * We can't use the "normal" timers since we just panicked. |
| 143 | */ |
| 144 | printk(KERN_EMERG "Rebooting in %d seconds..", panic_timeout); |
| 145 | |
TAMUKI Shoichi | c7ff0d9 | 2010-08-10 18:03:28 -0700 | [diff] [blame] | 146 | for (i = 0; i < panic_timeout * 1000; i += PANIC_TIMER_STEP) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 147 | touch_nmi_watchdog(); |
TAMUKI Shoichi | c7ff0d9 | 2010-08-10 18:03:28 -0700 | [diff] [blame] | 148 | if (i >= i_next) { |
| 149 | i += panic_blink(state ^= 1); |
| 150 | i_next = i + 3600 / PANIC_BLINK_SPD; |
| 151 | } |
| 152 | mdelay(PANIC_TIMER_STEP); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 153 | } |
Hugh Dickins | 4302fbc | 2011-07-26 16:08:52 -0700 | [diff] [blame] | 154 | } |
| 155 | if (panic_timeout != 0) { |
Ingo Molnar | c95dbf2 | 2009-03-13 11:14:06 +0100 | [diff] [blame] | 156 | /* |
| 157 | * This will not be a clean reboot, with everything |
| 158 | * shutting down. But if there is a chance of |
| 159 | * rebooting the system it will be rebooted. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 160 | */ |
Eric W. Biederman | 2f048ea | 2005-07-26 11:49:23 -0600 | [diff] [blame] | 161 | emergency_restart(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 162 | } |
| 163 | #ifdef __sparc__ |
| 164 | { |
| 165 | extern int stop_a_enabled; |
Tom 'spot' Callaway | a271c24 | 2005-04-24 20:38:02 -0700 | [diff] [blame] | 166 | /* Make sure the user can actually press Stop-A (L1-A) */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 167 | stop_a_enabled = 1; |
Tom 'spot' Callaway | a271c24 | 2005-04-24 20:38:02 -0700 | [diff] [blame] | 168 | printk(KERN_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] | 169 | } |
| 170 | #endif |
Martin Schwidefsky | 347a8dc | 2006-01-06 00:19:28 -0800 | [diff] [blame] | 171 | #if defined(CONFIG_S390) |
Ingo Molnar | c95dbf2 | 2009-03-13 11:14:06 +0100 | [diff] [blame] | 172 | { |
| 173 | unsigned long caller; |
| 174 | |
| 175 | caller = (unsigned long)__builtin_return_address(0); |
| 176 | disabled_wait(caller); |
| 177 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 178 | #endif |
| 179 | local_irq_enable(); |
TAMUKI Shoichi | c7ff0d9 | 2010-08-10 18:03:28 -0700 | [diff] [blame] | 180 | for (i = 0; ; i += PANIC_TIMER_STEP) { |
Jan Beulich | c22db94 | 2006-02-10 01:51:11 -0800 | [diff] [blame] | 181 | touch_softlockup_watchdog(); |
TAMUKI Shoichi | c7ff0d9 | 2010-08-10 18:03:28 -0700 | [diff] [blame] | 182 | if (i >= i_next) { |
| 183 | i += panic_blink(state ^= 1); |
| 184 | i_next = i + 3600 / PANIC_BLINK_SPD; |
| 185 | } |
| 186 | mdelay(PANIC_TIMER_STEP); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 187 | } |
| 188 | } |
| 189 | |
| 190 | EXPORT_SYMBOL(panic); |
| 191 | |
Daniel Walker | c277e63 | 2007-10-18 03:06:08 -0700 | [diff] [blame] | 192 | |
Andi Kleen | 25ddbb1 | 2008-10-15 22:01:41 -0700 | [diff] [blame] | 193 | struct tnt { |
Ingo Molnar | c95dbf2 | 2009-03-13 11:14:06 +0100 | [diff] [blame] | 194 | u8 bit; |
| 195 | char true; |
| 196 | char false; |
Andi Kleen | 25ddbb1 | 2008-10-15 22:01:41 -0700 | [diff] [blame] | 197 | }; |
| 198 | |
| 199 | static const struct tnt tnts[] = { |
Ingo Molnar | c95dbf2 | 2009-03-13 11:14:06 +0100 | [diff] [blame] | 200 | { TAINT_PROPRIETARY_MODULE, 'P', 'G' }, |
| 201 | { TAINT_FORCED_MODULE, 'F', ' ' }, |
| 202 | { TAINT_UNSAFE_SMP, 'S', ' ' }, |
| 203 | { TAINT_FORCED_RMMOD, 'R', ' ' }, |
| 204 | { TAINT_MACHINE_CHECK, 'M', ' ' }, |
| 205 | { TAINT_BAD_PAGE, 'B', ' ' }, |
| 206 | { TAINT_USER, 'U', ' ' }, |
| 207 | { TAINT_DIE, 'D', ' ' }, |
| 208 | { TAINT_OVERRIDDEN_ACPI_TABLE, 'A', ' ' }, |
| 209 | { TAINT_WARN, 'W', ' ' }, |
| 210 | { TAINT_CRAP, 'C', ' ' }, |
Ben Hutchings | 92946bc | 2010-04-03 19:36:42 +0100 | [diff] [blame] | 211 | { TAINT_FIRMWARE_WORKAROUND, 'I', ' ' }, |
Ben Hutchings | 2449b8b | 2011-10-24 15:12:28 +0200 | [diff] [blame] | 212 | { TAINT_OOT_MODULE, 'O', ' ' }, |
Andi Kleen | 25ddbb1 | 2008-10-15 22:01:41 -0700 | [diff] [blame] | 213 | }; |
| 214 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 215 | /** |
| 216 | * print_tainted - return a string to represent the kernel taint state. |
| 217 | * |
| 218 | * 'P' - Proprietary module has been loaded. |
| 219 | * 'F' - Module has been forcibly loaded. |
| 220 | * 'S' - SMP with CPUs not designed for SMP. |
| 221 | * 'R' - User forced a module unload. |
| 222 | * 'M' - System experienced a machine check exception. |
| 223 | * 'B' - System has hit bad_page. |
| 224 | * 'U' - Userspace-defined naughtiness. |
Arjan van de Ven | a800599 | 2008-12-01 13:14:00 -0800 | [diff] [blame] | 225 | * 'D' - Kernel has oopsed before |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 226 | * 'A' - ACPI table overridden. |
Theodore Ts'o | 34f5a39 | 2007-02-10 01:45:24 -0800 | [diff] [blame] | 227 | * 'W' - Taint on warning. |
Greg Kroah-Hartman | 061b1bd | 2008-09-24 14:46:44 -0700 | [diff] [blame] | 228 | * 'C' - modules from drivers/staging are loaded. |
Ben Hutchings | 92946bc | 2010-04-03 19:36:42 +0100 | [diff] [blame] | 229 | * 'I' - Working around severe firmware bug. |
Ben Hutchings | 2449b8b | 2011-10-24 15:12:28 +0200 | [diff] [blame] | 230 | * 'O' - Out-of-tree module has been loaded. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 231 | * |
Robert P. J. Day | fe002a4 | 2009-06-28 21:10:07 -0400 | [diff] [blame] | 232 | * The string is overwritten by the next call to print_tainted(). |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 233 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 234 | const char *print_tainted(void) |
| 235 | { |
Chen Gang | 0128476 | 2013-11-12 15:11:32 -0800 | [diff] [blame] | 236 | static char buf[ARRAY_SIZE(tnts) + sizeof("Tainted: ")]; |
Andi Kleen | 25ddbb1 | 2008-10-15 22:01:41 -0700 | [diff] [blame] | 237 | |
| 238 | if (tainted_mask) { |
| 239 | char *s; |
| 240 | int i; |
| 241 | |
| 242 | s = buf + sprintf(buf, "Tainted: "); |
| 243 | for (i = 0; i < ARRAY_SIZE(tnts); i++) { |
| 244 | const struct tnt *t = &tnts[i]; |
| 245 | *s++ = test_bit(t->bit, &tainted_mask) ? |
| 246 | t->true : t->false; |
| 247 | } |
| 248 | *s = 0; |
| 249 | } else |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 250 | snprintf(buf, sizeof(buf), "Not tainted"); |
Ingo Molnar | c95dbf2 | 2009-03-13 11:14:06 +0100 | [diff] [blame] | 251 | |
| 252 | return buf; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 253 | } |
| 254 | |
Andi Kleen | 25ddbb1 | 2008-10-15 22:01:41 -0700 | [diff] [blame] | 255 | int test_taint(unsigned flag) |
| 256 | { |
| 257 | return test_bit(flag, &tainted_mask); |
| 258 | } |
| 259 | EXPORT_SYMBOL(test_taint); |
| 260 | |
| 261 | unsigned long get_taint(void) |
| 262 | { |
| 263 | return tainted_mask; |
| 264 | } |
| 265 | |
Rusty Russell | 373d4d0 | 2013-01-21 17:17:39 +1030 | [diff] [blame] | 266 | /** |
| 267 | * add_taint: add a taint flag if not already set. |
| 268 | * @flag: one of the TAINT_* constants. |
| 269 | * @lockdep_ok: whether lock debugging is still OK. |
| 270 | * |
| 271 | * If something bad has gone wrong, you'll want @lockdebug_ok = false, but for |
| 272 | * some notewortht-but-not-corrupting cases, it can be set to true. |
| 273 | */ |
| 274 | void add_taint(unsigned flag, enum lockdep_ok lockdep_ok) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 275 | { |
Rusty Russell | 373d4d0 | 2013-01-21 17:17:39 +1030 | [diff] [blame] | 276 | if (lockdep_ok == LOCKDEP_NOW_UNRELIABLE && __debug_locks_off()) |
| 277 | printk(KERN_WARNING |
| 278 | "Disabling lock debugging due to kernel taint\n"); |
Frederic Weisbecker | 9eeba61 | 2009-04-11 03:17:17 +0200 | [diff] [blame] | 279 | |
Andi Kleen | 25ddbb1 | 2008-10-15 22:01:41 -0700 | [diff] [blame] | 280 | set_bit(flag, &tainted_mask); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 281 | } |
| 282 | EXPORT_SYMBOL(add_taint); |
Andrew Morton | dd28779 | 2006-03-23 03:00:57 -0800 | [diff] [blame] | 283 | |
Andrew Morton | dd28779 | 2006-03-23 03:00:57 -0800 | [diff] [blame] | 284 | static void spin_msec(int msecs) |
| 285 | { |
| 286 | int i; |
| 287 | |
| 288 | for (i = 0; i < msecs; i++) { |
| 289 | touch_nmi_watchdog(); |
| 290 | mdelay(1); |
| 291 | } |
| 292 | } |
| 293 | |
| 294 | /* |
| 295 | * It just happens that oops_enter() and oops_exit() are identically |
| 296 | * implemented... |
| 297 | */ |
| 298 | static void do_oops_enter_exit(void) |
| 299 | { |
| 300 | unsigned long flags; |
| 301 | static int spin_counter; |
| 302 | |
| 303 | if (!pause_on_oops) |
| 304 | return; |
| 305 | |
| 306 | spin_lock_irqsave(&pause_on_oops_lock, flags); |
| 307 | if (pause_on_oops_flag == 0) { |
| 308 | /* This CPU may now print the oops message */ |
| 309 | pause_on_oops_flag = 1; |
| 310 | } else { |
| 311 | /* We need to stall this CPU */ |
| 312 | if (!spin_counter) { |
| 313 | /* This CPU gets to do the counting */ |
| 314 | spin_counter = pause_on_oops; |
| 315 | do { |
| 316 | spin_unlock(&pause_on_oops_lock); |
| 317 | spin_msec(MSEC_PER_SEC); |
| 318 | spin_lock(&pause_on_oops_lock); |
| 319 | } while (--spin_counter); |
| 320 | pause_on_oops_flag = 0; |
| 321 | } else { |
| 322 | /* This CPU waits for a different one */ |
| 323 | while (spin_counter) { |
| 324 | spin_unlock(&pause_on_oops_lock); |
| 325 | spin_msec(1); |
| 326 | spin_lock(&pause_on_oops_lock); |
| 327 | } |
| 328 | } |
| 329 | } |
| 330 | spin_unlock_irqrestore(&pause_on_oops_lock, flags); |
| 331 | } |
| 332 | |
| 333 | /* |
Ingo Molnar | c95dbf2 | 2009-03-13 11:14:06 +0100 | [diff] [blame] | 334 | * Return true if the calling CPU is allowed to print oops-related info. |
| 335 | * This is a bit racy.. |
Andrew Morton | dd28779 | 2006-03-23 03:00:57 -0800 | [diff] [blame] | 336 | */ |
| 337 | int oops_may_print(void) |
| 338 | { |
| 339 | return pause_on_oops_flag == 0; |
| 340 | } |
| 341 | |
| 342 | /* |
| 343 | * Called when the architecture enters its oops handler, before it prints |
Ingo Molnar | c95dbf2 | 2009-03-13 11:14:06 +0100 | [diff] [blame] | 344 | * anything. If this is the first CPU to oops, and it's oopsing the first |
| 345 | * time then let it proceed. |
Andrew Morton | dd28779 | 2006-03-23 03:00:57 -0800 | [diff] [blame] | 346 | * |
Ingo Molnar | c95dbf2 | 2009-03-13 11:14:06 +0100 | [diff] [blame] | 347 | * This is all enabled by the pause_on_oops kernel boot option. We do all |
| 348 | * this to ensure that oopses don't scroll off the screen. It has the |
| 349 | * side-effect of preventing later-oopsing CPUs from mucking up the display, |
| 350 | * too. |
Andrew Morton | dd28779 | 2006-03-23 03:00:57 -0800 | [diff] [blame] | 351 | * |
Ingo Molnar | c95dbf2 | 2009-03-13 11:14:06 +0100 | [diff] [blame] | 352 | * It turns out that the CPU which is allowed to print ends up pausing for |
| 353 | * the right duration, whereas all the other CPUs pause for twice as long: |
| 354 | * once in oops_enter(), once in oops_exit(). |
Andrew Morton | dd28779 | 2006-03-23 03:00:57 -0800 | [diff] [blame] | 355 | */ |
| 356 | void oops_enter(void) |
| 357 | { |
Thomas Gleixner | bdff787 | 2009-07-24 15:30:45 -0400 | [diff] [blame] | 358 | tracing_off(); |
Ingo Molnar | c95dbf2 | 2009-03-13 11:14:06 +0100 | [diff] [blame] | 359 | /* can't trust the integrity of the kernel anymore: */ |
| 360 | debug_locks_off(); |
Andrew Morton | dd28779 | 2006-03-23 03:00:57 -0800 | [diff] [blame] | 361 | do_oops_enter_exit(); |
| 362 | } |
| 363 | |
| 364 | /* |
Arjan van de Ven | 2c3b20e9 | 2007-12-20 15:01:17 +0100 | [diff] [blame] | 365 | * 64-bit random ID for oopses: |
| 366 | */ |
| 367 | static u64 oops_id; |
| 368 | |
| 369 | static int init_oops_id(void) |
| 370 | { |
| 371 | if (!oops_id) |
| 372 | get_random_bytes(&oops_id, sizeof(oops_id)); |
Arjan van de Ven | d6624f9 | 2009-01-06 14:40:54 -0800 | [diff] [blame] | 373 | else |
| 374 | oops_id++; |
Arjan van de Ven | 2c3b20e9 | 2007-12-20 15:01:17 +0100 | [diff] [blame] | 375 | |
| 376 | return 0; |
| 377 | } |
| 378 | late_initcall(init_oops_id); |
| 379 | |
Anton Blanchard | 863a604 | 2010-08-10 18:03:30 -0700 | [diff] [blame] | 380 | void print_oops_end_marker(void) |
Arjan van de Ven | 71c3391 | 2008-01-30 13:32:50 +0100 | [diff] [blame] | 381 | { |
| 382 | init_oops_id(); |
| 383 | printk(KERN_WARNING "---[ end trace %016llx ]---\n", |
| 384 | (unsigned long long)oops_id); |
| 385 | } |
| 386 | |
Arjan van de Ven | 2c3b20e9 | 2007-12-20 15:01:17 +0100 | [diff] [blame] | 387 | /* |
Andrew Morton | dd28779 | 2006-03-23 03:00:57 -0800 | [diff] [blame] | 388 | * Called when the architecture exits its oops handler, after printing |
| 389 | * everything. |
| 390 | */ |
| 391 | void oops_exit(void) |
| 392 | { |
| 393 | do_oops_enter_exit(); |
Arjan van de Ven | 71c3391 | 2008-01-30 13:32:50 +0100 | [diff] [blame] | 394 | print_oops_end_marker(); |
Simon Kagstrom | 456b565 | 2009-10-16 14:09:18 +0200 | [diff] [blame] | 395 | kmsg_dump(KMSG_DUMP_OOPS); |
Andrew Morton | dd28779 | 2006-03-23 03:00:57 -0800 | [diff] [blame] | 396 | } |
Arjan van de Ven | 3162f75 | 2006-09-26 10:52:39 +0200 | [diff] [blame] | 397 | |
Arjan van de Ven | 79b4cc5 | 2008-01-30 13:32:50 +0100 | [diff] [blame] | 398 | #ifdef WANT_WARN_ON_SLOWPATH |
Linus Torvalds | 0f6f49a | 2009-05-16 13:41:28 -0700 | [diff] [blame] | 399 | struct slowpath_args { |
| 400 | const char *fmt; |
Arjan van de Ven | a8f18b9 | 2008-07-25 01:45:53 -0700 | [diff] [blame] | 401 | va_list args; |
Linus Torvalds | 0f6f49a | 2009-05-16 13:41:28 -0700 | [diff] [blame] | 402 | }; |
| 403 | |
Ben Hutchings | b2be052 | 2010-04-03 19:34:56 +0100 | [diff] [blame] | 404 | static void warn_slowpath_common(const char *file, int line, void *caller, |
| 405 | unsigned taint, struct slowpath_args *args) |
Linus Torvalds | 0f6f49a | 2009-05-16 13:41:28 -0700 | [diff] [blame] | 406 | { |
Steven Rostedt (Red Hat) | de7edd3 | 2013-06-14 16:21:43 -0400 | [diff] [blame] | 407 | disable_trace_on_warning(); |
| 408 | |
Alex Thorlton | dcb6b45 | 2013-07-08 16:00:42 -0700 | [diff] [blame] | 409 | pr_warn("------------[ cut here ]------------\n"); |
| 410 | pr_warn("WARNING: CPU: %d PID: %d at %s:%d %pS()\n", |
| 411 | raw_smp_processor_id(), current->pid, file, line, caller); |
Arjan van de Ven | 74853db | 2008-11-28 08:35:25 -0800 | [diff] [blame] | 412 | |
Linus Torvalds | 0f6f49a | 2009-05-16 13:41:28 -0700 | [diff] [blame] | 413 | if (args) |
| 414 | vprintk(args->fmt, args->args); |
Arjan van de Ven | a8f18b9 | 2008-07-25 01:45:53 -0700 | [diff] [blame] | 415 | |
| 416 | print_modules(); |
| 417 | dump_stack(); |
| 418 | print_oops_end_marker(); |
Rusty Russell | 373d4d0 | 2013-01-21 17:17:39 +1030 | [diff] [blame] | 419 | /* Just a warning, don't kill lockdep. */ |
| 420 | add_taint(taint, LOCKDEP_STILL_OK); |
Arjan van de Ven | a8f18b9 | 2008-07-25 01:45:53 -0700 | [diff] [blame] | 421 | } |
Linus Torvalds | 0f6f49a | 2009-05-16 13:41:28 -0700 | [diff] [blame] | 422 | |
| 423 | void warn_slowpath_fmt(const char *file, int line, const char *fmt, ...) |
| 424 | { |
| 425 | struct slowpath_args args; |
| 426 | |
| 427 | args.fmt = fmt; |
| 428 | va_start(args.args, fmt); |
Ben Hutchings | b2be052 | 2010-04-03 19:34:56 +0100 | [diff] [blame] | 429 | warn_slowpath_common(file, line, __builtin_return_address(0), |
| 430 | TAINT_WARN, &args); |
Linus Torvalds | 0f6f49a | 2009-05-16 13:41:28 -0700 | [diff] [blame] | 431 | va_end(args.args); |
| 432 | } |
Andi Kleen | 57adc4d | 2009-05-06 16:02:53 -0700 | [diff] [blame] | 433 | EXPORT_SYMBOL(warn_slowpath_fmt); |
| 434 | |
Ben Hutchings | b2be052 | 2010-04-03 19:34:56 +0100 | [diff] [blame] | 435 | void warn_slowpath_fmt_taint(const char *file, int line, |
| 436 | unsigned taint, const char *fmt, ...) |
| 437 | { |
| 438 | struct slowpath_args args; |
| 439 | |
| 440 | args.fmt = fmt; |
| 441 | va_start(args.args, fmt); |
| 442 | warn_slowpath_common(file, line, __builtin_return_address(0), |
| 443 | taint, &args); |
| 444 | va_end(args.args); |
| 445 | } |
| 446 | EXPORT_SYMBOL(warn_slowpath_fmt_taint); |
| 447 | |
Andi Kleen | 57adc4d | 2009-05-06 16:02:53 -0700 | [diff] [blame] | 448 | void warn_slowpath_null(const char *file, int line) |
| 449 | { |
Ben Hutchings | b2be052 | 2010-04-03 19:34:56 +0100 | [diff] [blame] | 450 | warn_slowpath_common(file, line, __builtin_return_address(0), |
| 451 | TAINT_WARN, NULL); |
Andi Kleen | 57adc4d | 2009-05-06 16:02:53 -0700 | [diff] [blame] | 452 | } |
| 453 | EXPORT_SYMBOL(warn_slowpath_null); |
Arjan van de Ven | 79b4cc5 | 2008-01-30 13:32:50 +0100 | [diff] [blame] | 454 | #endif |
| 455 | |
Arjan van de Ven | 3162f75 | 2006-09-26 10:52:39 +0200 | [diff] [blame] | 456 | #ifdef CONFIG_CC_STACKPROTECTOR |
Arjan van de Ven | 54371a4 | 2008-02-15 15:33:12 -0800 | [diff] [blame] | 457 | |
Arjan van de Ven | 3162f75 | 2006-09-26 10:52:39 +0200 | [diff] [blame] | 458 | /* |
| 459 | * Called when gcc's -fstack-protector feature is used, and |
| 460 | * gcc detects corruption of the on-stack canary value |
| 461 | */ |
| 462 | void __stack_chk_fail(void) |
| 463 | { |
Ingo Molnar | 517a92c | 2008-02-14 09:02:13 +0100 | [diff] [blame] | 464 | panic("stack-protector: Kernel stack is corrupted in: %p\n", |
| 465 | __builtin_return_address(0)); |
Arjan van de Ven | 3162f75 | 2006-09-26 10:52:39 +0200 | [diff] [blame] | 466 | } |
| 467 | EXPORT_SYMBOL(__stack_chk_fail); |
Arjan van de Ven | 54371a4 | 2008-02-15 15:33:12 -0800 | [diff] [blame] | 468 | |
Arjan van de Ven | 3162f75 | 2006-09-26 10:52:39 +0200 | [diff] [blame] | 469 | #endif |
Rusty Russell | f44dd16 | 2008-10-22 10:00:24 -0500 | [diff] [blame] | 470 | |
| 471 | core_param(panic, panic_timeout, int, 0644); |
| 472 | core_param(pause_on_oops, pause_on_oops, int, 0644); |
Olaf Hering | d404ab0 | 2011-03-22 16:34:04 -0700 | [diff] [blame] | 473 | |
| 474 | static int __init oops_setup(char *s) |
| 475 | { |
| 476 | if (!s) |
| 477 | return -EINVAL; |
| 478 | if (!strcmp(s, "panic")) |
| 479 | panic_on_oops = 1; |
| 480 | return 0; |
| 481 | } |
| 482 | early_param("oops", oops_setup); |