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Commit | Line | Data |
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1da177e4 LT |
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 | */ | |
c95dbf27 | 11 | #include <linux/debug_locks.h> |
b17b0153 | 12 | #include <linux/sched/debug.h> |
c95dbf27 | 13 | #include <linux/interrupt.h> |
456b565c | 14 | #include <linux/kmsg_dump.h> |
c95dbf27 IM |
15 | #include <linux/kallsyms.h> |
16 | #include <linux/notifier.h> | |
c7c3f05e | 17 | #include <linux/vt_kern.h> |
1da177e4 | 18 | #include <linux/module.h> |
c95dbf27 | 19 | #include <linux/random.h> |
de7edd31 | 20 | #include <linux/ftrace.h> |
1da177e4 | 21 | #include <linux/reboot.h> |
c95dbf27 IM |
22 | #include <linux/delay.h> |
23 | #include <linux/kexec.h> | |
24 | #include <linux/sched.h> | |
1da177e4 | 25 | #include <linux/sysrq.h> |
c95dbf27 | 26 | #include <linux/init.h> |
1da177e4 | 27 | #include <linux/nmi.h> |
08d78658 | 28 | #include <linux/console.h> |
2553b67a | 29 | #include <linux/bug.h> |
7a46ec0e | 30 | #include <linux/ratelimit.h> |
b1fca27d AK |
31 | #include <linux/debugfs.h> |
32 | #include <asm/sections.h> | |
1da177e4 | 33 | |
c7ff0d9c TS |
34 | #define PANIC_TIMER_STEP 100 |
35 | #define PANIC_BLINK_SPD 18 | |
36 | ||
2a01bb38 | 37 | int panic_on_oops = CONFIG_PANIC_ON_OOPS_VALUE; |
bc4f2f54 KC |
38 | static unsigned long tainted_mask = |
39 | IS_ENABLED(CONFIG_GCC_PLUGIN_RANDSTRUCT) ? (1 << TAINT_RANDSTRUCT) : 0; | |
dd287796 AM |
40 | static int pause_on_oops; |
41 | static int pause_on_oops_flag; | |
42 | static DEFINE_SPINLOCK(pause_on_oops_lock); | |
5375b708 | 43 | bool crash_kexec_post_notifiers; |
9e3961a0 | 44 | int panic_on_warn __read_mostly; |
1da177e4 | 45 | |
5800dc3c | 46 | int panic_timeout = CONFIG_PANIC_TIMEOUT; |
81e88fdc | 47 | EXPORT_SYMBOL_GPL(panic_timeout); |
1da177e4 | 48 | |
e041c683 | 49 | ATOMIC_NOTIFIER_HEAD(panic_notifier_list); |
1da177e4 LT |
50 | |
51 | EXPORT_SYMBOL(panic_notifier_list); | |
52 | ||
c7ff0d9c | 53 | static long no_blink(int state) |
8aeee85a | 54 | { |
c7ff0d9c | 55 | return 0; |
8aeee85a AB |
56 | } |
57 | ||
c7ff0d9c TS |
58 | /* Returns how long it waited in ms */ |
59 | long (*panic_blink)(int state); | |
60 | EXPORT_SYMBOL(panic_blink); | |
61 | ||
93e13a36 MH |
62 | /* |
63 | * Stop ourself in panic -- architecture code may override this | |
64 | */ | |
65 | void __weak panic_smp_self_stop(void) | |
66 | { | |
67 | while (1) | |
68 | cpu_relax(); | |
69 | } | |
70 | ||
58c5661f HK |
71 | /* |
72 | * Stop ourselves in NMI context if another CPU has already panicked. Arch code | |
73 | * may override this to prepare for crash dumping, e.g. save regs info. | |
74 | */ | |
75 | void __weak nmi_panic_self_stop(struct pt_regs *regs) | |
76 | { | |
77 | panic_smp_self_stop(); | |
78 | } | |
79 | ||
0ee59413 HK |
80 | /* |
81 | * Stop other CPUs in panic. Architecture dependent code may override this | |
82 | * with more suitable version. For example, if the architecture supports | |
83 | * crash dump, it should save registers of each stopped CPU and disable | |
84 | * per-CPU features such as virtualization extensions. | |
85 | */ | |
86 | void __weak crash_smp_send_stop(void) | |
87 | { | |
88 | static int cpus_stopped; | |
89 | ||
90 | /* | |
91 | * This function can be called twice in panic path, but obviously | |
92 | * we execute this only once. | |
93 | */ | |
94 | if (cpus_stopped) | |
95 | return; | |
96 | ||
97 | /* | |
98 | * Note smp_send_stop is the usual smp shutdown function, which | |
99 | * unfortunately means it may not be hardened to work in a panic | |
100 | * situation. | |
101 | */ | |
102 | smp_send_stop(); | |
103 | cpus_stopped = 1; | |
104 | } | |
105 | ||
1717f209 HK |
106 | atomic_t panic_cpu = ATOMIC_INIT(PANIC_CPU_INVALID); |
107 | ||
ebc41f20 HK |
108 | /* |
109 | * A variant of panic() called from NMI context. We return if we've already | |
110 | * panicked on this CPU. If another CPU already panicked, loop in | |
111 | * nmi_panic_self_stop() which can provide architecture dependent code such | |
112 | * as saving register state for crash dump. | |
113 | */ | |
114 | void nmi_panic(struct pt_regs *regs, const char *msg) | |
115 | { | |
116 | int old_cpu, cpu; | |
117 | ||
118 | cpu = raw_smp_processor_id(); | |
119 | old_cpu = atomic_cmpxchg(&panic_cpu, PANIC_CPU_INVALID, cpu); | |
120 | ||
121 | if (old_cpu == PANIC_CPU_INVALID) | |
122 | panic("%s", msg); | |
123 | else if (old_cpu != cpu) | |
124 | nmi_panic_self_stop(regs); | |
125 | } | |
126 | EXPORT_SYMBOL(nmi_panic); | |
127 | ||
1da177e4 LT |
128 | /** |
129 | * panic - halt the system | |
130 | * @fmt: The text string to print | |
131 | * | |
132 | * Display a message, then perform cleanups. | |
133 | * | |
134 | * This function never returns. | |
135 | */ | |
9402c95f | 136 | void panic(const char *fmt, ...) |
1da177e4 | 137 | { |
1da177e4 LT |
138 | static char buf[1024]; |
139 | va_list args; | |
b49dec1c | 140 | long i, i_next = 0, len; |
c7ff0d9c | 141 | int state = 0; |
1717f209 | 142 | int old_cpu, this_cpu; |
b26e27dd | 143 | bool _crash_kexec_post_notifiers = crash_kexec_post_notifiers; |
1da177e4 | 144 | |
190320c3 VM |
145 | /* |
146 | * Disable local interrupts. This will prevent panic_smp_self_stop | |
147 | * from deadlocking the first cpu that invokes the panic, since | |
148 | * there is nothing to prevent an interrupt handler (that runs | |
1717f209 | 149 | * after setting panic_cpu) from invoking panic() again. |
190320c3 VM |
150 | */ |
151 | local_irq_disable(); | |
152 | ||
dc009d92 | 153 | /* |
c95dbf27 IM |
154 | * It's possible to come here directly from a panic-assertion and |
155 | * not have preempt disabled. Some functions called from here want | |
dc009d92 | 156 | * preempt to be disabled. No point enabling it later though... |
93e13a36 MH |
157 | * |
158 | * Only one CPU is allowed to execute the panic code from here. For | |
159 | * multiple parallel invocations of panic, all other CPUs either | |
160 | * stop themself or will wait until they are stopped by the 1st CPU | |
161 | * with smp_send_stop(). | |
1717f209 HK |
162 | * |
163 | * `old_cpu == PANIC_CPU_INVALID' means this is the 1st CPU which | |
164 | * comes here, so go ahead. | |
165 | * `old_cpu == this_cpu' means we came from nmi_panic() which sets | |
166 | * panic_cpu to this CPU. In this case, this is also the 1st CPU. | |
dc009d92 | 167 | */ |
1717f209 HK |
168 | this_cpu = raw_smp_processor_id(); |
169 | old_cpu = atomic_cmpxchg(&panic_cpu, PANIC_CPU_INVALID, this_cpu); | |
170 | ||
171 | if (old_cpu != PANIC_CPU_INVALID && old_cpu != this_cpu) | |
93e13a36 | 172 | panic_smp_self_stop(); |
dc009d92 | 173 | |
5b530fc1 | 174 | console_verbose(); |
1da177e4 LT |
175 | bust_spinlocks(1); |
176 | va_start(args, fmt); | |
b49dec1c | 177 | len = vscnprintf(buf, sizeof(buf), fmt, args); |
1da177e4 | 178 | va_end(args); |
b49dec1c BP |
179 | |
180 | if (len && buf[len - 1] == '\n') | |
181 | buf[len - 1] = '\0'; | |
182 | ||
d7c0847f | 183 | pr_emerg("Kernel panic - not syncing: %s\n", buf); |
5cb27301 | 184 | #ifdef CONFIG_DEBUG_BUGVERBOSE |
6e6f0a1f AK |
185 | /* |
186 | * Avoid nested stack-dumping if a panic occurs during oops processing | |
187 | */ | |
026ee1f6 | 188 | if (!test_taint(TAINT_DIE) && oops_in_progress <= 1) |
6e6f0a1f | 189 | dump_stack(); |
5cb27301 | 190 | #endif |
1da177e4 | 191 | |
dc009d92 EB |
192 | /* |
193 | * If we have crashed and we have a crash kernel loaded let it handle | |
194 | * everything else. | |
f06e5153 MH |
195 | * If we want to run this after calling panic_notifiers, pass |
196 | * the "crash_kexec_post_notifiers" option to the kernel. | |
7bbee5ca HK |
197 | * |
198 | * Bypass the panic_cpu check and call __crash_kexec directly. | |
dc009d92 | 199 | */ |
b26e27dd | 200 | if (!_crash_kexec_post_notifiers) { |
f92bac3b | 201 | printk_safe_flush_on_panic(); |
7bbee5ca | 202 | __crash_kexec(NULL); |
dc009d92 | 203 | |
0ee59413 HK |
204 | /* |
205 | * Note smp_send_stop is the usual smp shutdown function, which | |
206 | * unfortunately means it may not be hardened to work in a | |
207 | * panic situation. | |
208 | */ | |
209 | smp_send_stop(); | |
210 | } else { | |
211 | /* | |
212 | * If we want to do crash dump after notifier calls and | |
213 | * kmsg_dump, we will need architecture dependent extra | |
214 | * works in addition to stopping other CPUs. | |
215 | */ | |
216 | crash_smp_send_stop(); | |
217 | } | |
1da177e4 | 218 | |
6723734c KC |
219 | /* |
220 | * Run any panic handlers, including those that might need to | |
221 | * add information to the kmsg dump output. | |
222 | */ | |
e041c683 | 223 | atomic_notifier_call_chain(&panic_notifier_list, 0, buf); |
1da177e4 | 224 | |
cf9b1106 | 225 | /* Call flush even twice. It tries harder with a single online CPU */ |
f92bac3b | 226 | printk_safe_flush_on_panic(); |
6723734c KC |
227 | kmsg_dump(KMSG_DUMP_PANIC); |
228 | ||
f06e5153 MH |
229 | /* |
230 | * If you doubt kdump always works fine in any situation, | |
231 | * "crash_kexec_post_notifiers" offers you a chance to run | |
232 | * panic_notifiers and dumping kmsg before kdump. | |
233 | * Note: since some panic_notifiers can make crashed kernel | |
234 | * more unstable, it can increase risks of the kdump failure too. | |
7bbee5ca HK |
235 | * |
236 | * Bypass the panic_cpu check and call __crash_kexec directly. | |
f06e5153 | 237 | */ |
b26e27dd | 238 | if (_crash_kexec_post_notifiers) |
7bbee5ca | 239 | __crash_kexec(NULL); |
f06e5153 | 240 | |
c7c3f05e SS |
241 | #ifdef CONFIG_VT |
242 | unblank_screen(); | |
243 | #endif | |
244 | console_unblank(); | |
d014e889 | 245 | |
08d78658 VK |
246 | /* |
247 | * We may have ended up stopping the CPU holding the lock (in | |
248 | * smp_send_stop()) while still having some valuable data in the console | |
249 | * buffer. Try to acquire the lock then release it regardless of the | |
7625b3a0 VK |
250 | * result. The release will also print the buffers out. Locks debug |
251 | * should be disabled to avoid reporting bad unlock balance when | |
252 | * panic() is not being callled from OOPS. | |
08d78658 | 253 | */ |
7625b3a0 | 254 | debug_locks_off(); |
8d91f8b1 | 255 | console_flush_on_panic(); |
08d78658 | 256 | |
c7ff0d9c TS |
257 | if (!panic_blink) |
258 | panic_blink = no_blink; | |
259 | ||
dc009d92 | 260 | if (panic_timeout > 0) { |
1da177e4 | 261 | /* |
c95dbf27 IM |
262 | * Delay timeout seconds before rebooting the machine. |
263 | * We can't use the "normal" timers since we just panicked. | |
264 | */ | |
ff7a28a0 | 265 | pr_emerg("Rebooting in %d seconds..\n", panic_timeout); |
c95dbf27 | 266 | |
c7ff0d9c | 267 | for (i = 0; i < panic_timeout * 1000; i += PANIC_TIMER_STEP) { |
1da177e4 | 268 | touch_nmi_watchdog(); |
c7ff0d9c TS |
269 | if (i >= i_next) { |
270 | i += panic_blink(state ^= 1); | |
271 | i_next = i + 3600 / PANIC_BLINK_SPD; | |
272 | } | |
273 | mdelay(PANIC_TIMER_STEP); | |
1da177e4 | 274 | } |
4302fbc8 HD |
275 | } |
276 | if (panic_timeout != 0) { | |
c95dbf27 IM |
277 | /* |
278 | * This will not be a clean reboot, with everything | |
279 | * shutting down. But if there is a chance of | |
280 | * rebooting the system it will be rebooted. | |
1da177e4 | 281 | */ |
2f048ea8 | 282 | emergency_restart(); |
1da177e4 LT |
283 | } |
284 | #ifdef __sparc__ | |
285 | { | |
286 | extern int stop_a_enabled; | |
a271c241 | 287 | /* Make sure the user can actually press Stop-A (L1-A) */ |
1da177e4 | 288 | stop_a_enabled = 1; |
7db60d05 VK |
289 | pr_emerg("Press Stop-A (L1-A) from sun keyboard or send break\n" |
290 | "twice on console to return to the boot prom\n"); | |
1da177e4 LT |
291 | } |
292 | #endif | |
347a8dc3 | 293 | #if defined(CONFIG_S390) |
c95dbf27 IM |
294 | { |
295 | unsigned long caller; | |
296 | ||
297 | caller = (unsigned long)__builtin_return_address(0); | |
298 | disabled_wait(caller); | |
299 | } | |
1da177e4 | 300 | #endif |
5ad75105 | 301 | pr_emerg("---[ end Kernel panic - not syncing: %s ]---\n", buf); |
1da177e4 | 302 | local_irq_enable(); |
c7ff0d9c | 303 | for (i = 0; ; i += PANIC_TIMER_STEP) { |
c22db941 | 304 | touch_softlockup_watchdog(); |
c7ff0d9c TS |
305 | if (i >= i_next) { |
306 | i += panic_blink(state ^= 1); | |
307 | i_next = i + 3600 / PANIC_BLINK_SPD; | |
308 | } | |
309 | mdelay(PANIC_TIMER_STEP); | |
1da177e4 LT |
310 | } |
311 | } | |
312 | ||
313 | EXPORT_SYMBOL(panic); | |
314 | ||
7fd8329b PM |
315 | /* |
316 | * TAINT_FORCED_RMMOD could be a per-module flag but the module | |
317 | * is being removed anyway. | |
318 | */ | |
319 | const struct taint_flag taint_flags[TAINT_FLAGS_COUNT] = { | |
47d4b263 KC |
320 | [ TAINT_PROPRIETARY_MODULE ] = { 'P', 'G', true }, |
321 | [ TAINT_FORCED_MODULE ] = { 'F', ' ', true }, | |
322 | [ TAINT_CPU_OUT_OF_SPEC ] = { 'S', ' ', false }, | |
323 | [ TAINT_FORCED_RMMOD ] = { 'R', ' ', false }, | |
324 | [ TAINT_MACHINE_CHECK ] = { 'M', ' ', false }, | |
325 | [ TAINT_BAD_PAGE ] = { 'B', ' ', false }, | |
326 | [ TAINT_USER ] = { 'U', ' ', false }, | |
327 | [ TAINT_DIE ] = { 'D', ' ', false }, | |
328 | [ TAINT_OVERRIDDEN_ACPI_TABLE ] = { 'A', ' ', false }, | |
329 | [ TAINT_WARN ] = { 'W', ' ', false }, | |
330 | [ TAINT_CRAP ] = { 'C', ' ', true }, | |
331 | [ TAINT_FIRMWARE_WORKAROUND ] = { 'I', ' ', false }, | |
332 | [ TAINT_OOT_MODULE ] = { 'O', ' ', true }, | |
333 | [ TAINT_UNSIGNED_MODULE ] = { 'E', ' ', true }, | |
334 | [ TAINT_SOFTLOCKUP ] = { 'L', ' ', false }, | |
335 | [ TAINT_LIVEPATCH ] = { 'K', ' ', true }, | |
336 | [ TAINT_AUX ] = { 'X', ' ', true }, | |
bc4f2f54 | 337 | [ TAINT_RANDSTRUCT ] = { 'T', ' ', true }, |
25ddbb18 AK |
338 | }; |
339 | ||
1da177e4 | 340 | /** |
9c4560e5 | 341 | * print_tainted - return a string to represent the kernel taint state. |
1da177e4 | 342 | * |
9c4560e5 | 343 | * For individual taint flag meanings, see Documentation/sysctl/kernel.txt |
1da177e4 | 344 | * |
9c4560e5 KC |
345 | * The string is overwritten by the next call to print_tainted(), |
346 | * but is always NULL terminated. | |
1da177e4 | 347 | */ |
1da177e4 LT |
348 | const char *print_tainted(void) |
349 | { | |
7fd8329b | 350 | static char buf[TAINT_FLAGS_COUNT + sizeof("Tainted: ")]; |
25ddbb18 | 351 | |
47d4b263 KC |
352 | BUILD_BUG_ON(ARRAY_SIZE(taint_flags) != TAINT_FLAGS_COUNT); |
353 | ||
25ddbb18 AK |
354 | if (tainted_mask) { |
355 | char *s; | |
356 | int i; | |
357 | ||
358 | s = buf + sprintf(buf, "Tainted: "); | |
7fd8329b PM |
359 | for (i = 0; i < TAINT_FLAGS_COUNT; i++) { |
360 | const struct taint_flag *t = &taint_flags[i]; | |
361 | *s++ = test_bit(i, &tainted_mask) ? | |
5eb7c0d0 | 362 | t->c_true : t->c_false; |
25ddbb18 AK |
363 | } |
364 | *s = 0; | |
365 | } else | |
1da177e4 | 366 | snprintf(buf, sizeof(buf), "Not tainted"); |
c95dbf27 IM |
367 | |
368 | return buf; | |
1da177e4 LT |
369 | } |
370 | ||
25ddbb18 | 371 | int test_taint(unsigned flag) |
1da177e4 | 372 | { |
25ddbb18 AK |
373 | return test_bit(flag, &tainted_mask); |
374 | } | |
375 | EXPORT_SYMBOL(test_taint); | |
376 | ||
377 | unsigned long get_taint(void) | |
378 | { | |
379 | return tainted_mask; | |
1da177e4 | 380 | } |
dd287796 | 381 | |
373d4d09 RR |
382 | /** |
383 | * add_taint: add a taint flag if not already set. | |
384 | * @flag: one of the TAINT_* constants. | |
385 | * @lockdep_ok: whether lock debugging is still OK. | |
386 | * | |
387 | * If something bad has gone wrong, you'll want @lockdebug_ok = false, but for | |
388 | * some notewortht-but-not-corrupting cases, it can be set to true. | |
389 | */ | |
390 | void add_taint(unsigned flag, enum lockdep_ok lockdep_ok) | |
dd287796 | 391 | { |
373d4d09 | 392 | if (lockdep_ok == LOCKDEP_NOW_UNRELIABLE && __debug_locks_off()) |
d7c0847f | 393 | pr_warn("Disabling lock debugging due to kernel taint\n"); |
9eeba613 | 394 | |
25ddbb18 | 395 | set_bit(flag, &tainted_mask); |
dd287796 | 396 | } |
1da177e4 | 397 | EXPORT_SYMBOL(add_taint); |
dd287796 AM |
398 | |
399 | static void spin_msec(int msecs) | |
400 | { | |
401 | int i; | |
402 | ||
403 | for (i = 0; i < msecs; i++) { | |
404 | touch_nmi_watchdog(); | |
405 | mdelay(1); | |
406 | } | |
407 | } | |
408 | ||
409 | /* | |
410 | * It just happens that oops_enter() and oops_exit() are identically | |
411 | * implemented... | |
412 | */ | |
413 | static void do_oops_enter_exit(void) | |
414 | { | |
415 | unsigned long flags; | |
416 | static int spin_counter; | |
417 | ||
418 | if (!pause_on_oops) | |
419 | return; | |
420 | ||
421 | spin_lock_irqsave(&pause_on_oops_lock, flags); | |
422 | if (pause_on_oops_flag == 0) { | |
423 | /* This CPU may now print the oops message */ | |
424 | pause_on_oops_flag = 1; | |
425 | } else { | |
426 | /* We need to stall this CPU */ | |
427 | if (!spin_counter) { | |
428 | /* This CPU gets to do the counting */ | |
429 | spin_counter = pause_on_oops; | |
430 | do { | |
431 | spin_unlock(&pause_on_oops_lock); | |
432 | spin_msec(MSEC_PER_SEC); | |
433 | spin_lock(&pause_on_oops_lock); | |
434 | } while (--spin_counter); | |
435 | pause_on_oops_flag = 0; | |
436 | } else { | |
437 | /* This CPU waits for a different one */ | |
438 | while (spin_counter) { | |
439 | spin_unlock(&pause_on_oops_lock); | |
440 | spin_msec(1); | |
441 | spin_lock(&pause_on_oops_lock); | |
442 | } | |
443 | } | |
444 | } | |
445 | spin_unlock_irqrestore(&pause_on_oops_lock, flags); | |
446 | } | |
447 | ||
448 | /* | |
c95dbf27 IM |
449 | * Return true if the calling CPU is allowed to print oops-related info. |
450 | * This is a bit racy.. | |
dd287796 AM |
451 | */ |
452 | int oops_may_print(void) | |
453 | { | |
454 | return pause_on_oops_flag == 0; | |
455 | } | |
456 | ||
457 | /* | |
458 | * Called when the architecture enters its oops handler, before it prints | |
c95dbf27 IM |
459 | * anything. If this is the first CPU to oops, and it's oopsing the first |
460 | * time then let it proceed. | |
dd287796 | 461 | * |
c95dbf27 IM |
462 | * This is all enabled by the pause_on_oops kernel boot option. We do all |
463 | * this to ensure that oopses don't scroll off the screen. It has the | |
464 | * side-effect of preventing later-oopsing CPUs from mucking up the display, | |
465 | * too. | |
dd287796 | 466 | * |
c95dbf27 IM |
467 | * It turns out that the CPU which is allowed to print ends up pausing for |
468 | * the right duration, whereas all the other CPUs pause for twice as long: | |
469 | * once in oops_enter(), once in oops_exit(). | |
dd287796 AM |
470 | */ |
471 | void oops_enter(void) | |
472 | { | |
bdff7870 | 473 | tracing_off(); |
c95dbf27 IM |
474 | /* can't trust the integrity of the kernel anymore: */ |
475 | debug_locks_off(); | |
dd287796 AM |
476 | do_oops_enter_exit(); |
477 | } | |
478 | ||
2c3b20e9 AV |
479 | /* |
480 | * 64-bit random ID for oopses: | |
481 | */ | |
482 | static u64 oops_id; | |
483 | ||
484 | static int init_oops_id(void) | |
485 | { | |
486 | if (!oops_id) | |
487 | get_random_bytes(&oops_id, sizeof(oops_id)); | |
d6624f99 AV |
488 | else |
489 | oops_id++; | |
2c3b20e9 AV |
490 | |
491 | return 0; | |
492 | } | |
493 | late_initcall(init_oops_id); | |
494 | ||
863a6049 | 495 | void print_oops_end_marker(void) |
71c33911 AV |
496 | { |
497 | init_oops_id(); | |
d7c0847f | 498 | pr_warn("---[ end trace %016llx ]---\n", (unsigned long long)oops_id); |
71c33911 AV |
499 | } |
500 | ||
dd287796 AM |
501 | /* |
502 | * Called when the architecture exits its oops handler, after printing | |
503 | * everything. | |
504 | */ | |
505 | void oops_exit(void) | |
506 | { | |
507 | do_oops_enter_exit(); | |
71c33911 | 508 | print_oops_end_marker(); |
456b565c | 509 | kmsg_dump(KMSG_DUMP_OOPS); |
dd287796 | 510 | } |
3162f751 | 511 | |
2553b67a | 512 | struct warn_args { |
0f6f49a8 | 513 | const char *fmt; |
a8f18b90 | 514 | va_list args; |
0f6f49a8 | 515 | }; |
bd89bb29 | 516 | |
2553b67a JP |
517 | void __warn(const char *file, int line, void *caller, unsigned taint, |
518 | struct pt_regs *regs, struct warn_args *args) | |
0f6f49a8 | 519 | { |
de7edd31 SRRH |
520 | disable_trace_on_warning(); |
521 | ||
a7bed27a KC |
522 | if (args) |
523 | pr_warn(CUT_HERE); | |
2553b67a JP |
524 | |
525 | if (file) | |
526 | pr_warn("WARNING: CPU: %d PID: %d at %s:%d %pS\n", | |
527 | raw_smp_processor_id(), current->pid, file, line, | |
528 | caller); | |
529 | else | |
530 | pr_warn("WARNING: CPU: %d PID: %d at %pS\n", | |
531 | raw_smp_processor_id(), current->pid, caller); | |
74853dba | 532 | |
0f6f49a8 LT |
533 | if (args) |
534 | vprintk(args->fmt, args->args); | |
a8f18b90 | 535 | |
9e3961a0 PB |
536 | if (panic_on_warn) { |
537 | /* | |
538 | * This thread may hit another WARN() in the panic path. | |
539 | * Resetting this prevents additional WARN() from panicking the | |
540 | * system on this thread. Other threads are blocked by the | |
541 | * panic_mutex in panic(). | |
542 | */ | |
543 | panic_on_warn = 0; | |
544 | panic("panic_on_warn set ...\n"); | |
545 | } | |
546 | ||
a8f18b90 | 547 | print_modules(); |
2553b67a JP |
548 | |
549 | if (regs) | |
550 | show_regs(regs); | |
551 | else | |
552 | dump_stack(); | |
553 | ||
4c281074 SRV |
554 | print_irqtrace_events(current); |
555 | ||
a8f18b90 | 556 | print_oops_end_marker(); |
2553b67a | 557 | |
373d4d09 RR |
558 | /* Just a warning, don't kill lockdep. */ |
559 | add_taint(taint, LOCKDEP_STILL_OK); | |
a8f18b90 | 560 | } |
0f6f49a8 | 561 | |
2553b67a | 562 | #ifdef WANT_WARN_ON_SLOWPATH |
0f6f49a8 LT |
563 | void warn_slowpath_fmt(const char *file, int line, const char *fmt, ...) |
564 | { | |
2553b67a | 565 | struct warn_args args; |
0f6f49a8 LT |
566 | |
567 | args.fmt = fmt; | |
568 | va_start(args.args, fmt); | |
2553b67a JP |
569 | __warn(file, line, __builtin_return_address(0), TAINT_WARN, NULL, |
570 | &args); | |
0f6f49a8 LT |
571 | va_end(args.args); |
572 | } | |
57adc4d2 AK |
573 | EXPORT_SYMBOL(warn_slowpath_fmt); |
574 | ||
b2be0527 BH |
575 | void warn_slowpath_fmt_taint(const char *file, int line, |
576 | unsigned taint, const char *fmt, ...) | |
577 | { | |
2553b67a | 578 | struct warn_args args; |
b2be0527 BH |
579 | |
580 | args.fmt = fmt; | |
581 | va_start(args.args, fmt); | |
2553b67a | 582 | __warn(file, line, __builtin_return_address(0), taint, NULL, &args); |
b2be0527 BH |
583 | va_end(args.args); |
584 | } | |
585 | EXPORT_SYMBOL(warn_slowpath_fmt_taint); | |
586 | ||
57adc4d2 AK |
587 | void warn_slowpath_null(const char *file, int line) |
588 | { | |
a7bed27a | 589 | pr_warn(CUT_HERE); |
2553b67a | 590 | __warn(file, line, __builtin_return_address(0), TAINT_WARN, NULL, NULL); |
57adc4d2 AK |
591 | } |
592 | EXPORT_SYMBOL(warn_slowpath_null); | |
a7bed27a KC |
593 | #else |
594 | void __warn_printk(const char *fmt, ...) | |
595 | { | |
596 | va_list args; | |
597 | ||
598 | pr_warn(CUT_HERE); | |
599 | ||
600 | va_start(args, fmt); | |
601 | vprintk(fmt, args); | |
602 | va_end(args); | |
603 | } | |
604 | EXPORT_SYMBOL(__warn_printk); | |
79b4cc5e AV |
605 | #endif |
606 | ||
b1fca27d AK |
607 | #ifdef CONFIG_BUG |
608 | ||
609 | /* Support resetting WARN*_ONCE state */ | |
610 | ||
611 | static int clear_warn_once_set(void *data, u64 val) | |
612 | { | |
aaf5dcfb | 613 | generic_bug_clear_once(); |
b1fca27d AK |
614 | memset(__start_once, 0, __end_once - __start_once); |
615 | return 0; | |
616 | } | |
617 | ||
618 | DEFINE_SIMPLE_ATTRIBUTE(clear_warn_once_fops, | |
619 | NULL, | |
620 | clear_warn_once_set, | |
621 | "%lld\n"); | |
622 | ||
623 | static __init int register_warn_debugfs(void) | |
624 | { | |
625 | /* Don't care about failure */ | |
aaf5dcfb | 626 | debugfs_create_file("clear_warn_once", 0200, NULL, |
b1fca27d AK |
627 | NULL, &clear_warn_once_fops); |
628 | return 0; | |
629 | } | |
630 | ||
631 | device_initcall(register_warn_debugfs); | |
632 | #endif | |
633 | ||
050e9baa | 634 | #ifdef CONFIG_STACKPROTECTOR |
54371a43 | 635 | |
3162f751 AV |
636 | /* |
637 | * Called when gcc's -fstack-protector feature is used, and | |
638 | * gcc detects corruption of the on-stack canary value | |
639 | */ | |
a7330c99 | 640 | __visible void __stack_chk_fail(void) |
3162f751 | 641 | { |
95c4fb78 | 642 | panic("stack-protector: Kernel stack is corrupted in: %pB", |
517a92c4 | 643 | __builtin_return_address(0)); |
3162f751 AV |
644 | } |
645 | EXPORT_SYMBOL(__stack_chk_fail); | |
54371a43 | 646 | |
3162f751 | 647 | #endif |
f44dd164 | 648 | |
7a46ec0e KC |
649 | #ifdef CONFIG_ARCH_HAS_REFCOUNT |
650 | void refcount_error_report(struct pt_regs *regs, const char *err) | |
651 | { | |
652 | WARN_RATELIMIT(1, "refcount_t %s at %pB in %s[%d], uid/euid: %u/%u\n", | |
653 | err, (void *)instruction_pointer(regs), | |
654 | current->comm, task_pid_nr(current), | |
655 | from_kuid_munged(&init_user_ns, current_uid()), | |
656 | from_kuid_munged(&init_user_ns, current_euid())); | |
657 | } | |
658 | #endif | |
659 | ||
f44dd164 RR |
660 | core_param(panic, panic_timeout, int, 0644); |
661 | core_param(pause_on_oops, pause_on_oops, int, 0644); | |
9e3961a0 | 662 | core_param(panic_on_warn, panic_on_warn, int, 0644); |
b26e27dd | 663 | core_param(crash_kexec_post_notifiers, crash_kexec_post_notifiers, bool, 0644); |
f06e5153 | 664 | |
d404ab0a OH |
665 | static int __init oops_setup(char *s) |
666 | { | |
667 | if (!s) | |
668 | return -EINVAL; | |
669 | if (!strcmp(s, "panic")) | |
670 | panic_on_oops = 1; | |
671 | return 0; | |
672 | } | |
673 | early_param("oops", oops_setup); |