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