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1da177e4 LT |
1 | /* |
2 | * linux/arch/x86-64/traps.c | |
3 | * | |
4 | * Copyright (C) 1991, 1992 Linus Torvalds | |
5 | * Copyright (C) 2000, 2001, 2002 Andi Kleen, SuSE Labs | |
6 | * | |
7 | * Pentium III FXSR, SSE support | |
8 | * Gareth Hughes <gareth@valinux.com>, May 2000 | |
9 | * | |
10 | * $Id: traps.c,v 1.36 2002/03/24 11:09:10 ak Exp $ | |
11 | */ | |
12 | ||
13 | /* | |
14 | * 'Traps.c' handles hardware traps and faults after we have saved some | |
15 | * state in 'entry.S'. | |
16 | */ | |
17 | #include <linux/config.h> | |
18 | #include <linux/sched.h> | |
19 | #include <linux/kernel.h> | |
20 | #include <linux/string.h> | |
21 | #include <linux/errno.h> | |
22 | #include <linux/ptrace.h> | |
23 | #include <linux/timer.h> | |
24 | #include <linux/mm.h> | |
25 | #include <linux/init.h> | |
26 | #include <linux/delay.h> | |
27 | #include <linux/spinlock.h> | |
28 | #include <linux/interrupt.h> | |
29 | #include <linux/module.h> | |
30 | #include <linux/moduleparam.h> | |
35faa714 | 31 | #include <linux/nmi.h> |
0f2fbdcb | 32 | #include <linux/kprobes.h> |
1da177e4 LT |
33 | |
34 | #include <asm/system.h> | |
35 | #include <asm/uaccess.h> | |
36 | #include <asm/io.h> | |
37 | #include <asm/atomic.h> | |
38 | #include <asm/debugreg.h> | |
39 | #include <asm/desc.h> | |
40 | #include <asm/i387.h> | |
41 | #include <asm/kdebug.h> | |
42 | #include <asm/processor.h> | |
43 | ||
44 | #include <asm/smp.h> | |
45 | #include <asm/pgalloc.h> | |
46 | #include <asm/pda.h> | |
47 | #include <asm/proto.h> | |
48 | #include <asm/nmi.h> | |
49 | ||
1da177e4 LT |
50 | extern struct gate_struct idt_table[256]; |
51 | ||
52 | asmlinkage void divide_error(void); | |
53 | asmlinkage void debug(void); | |
54 | asmlinkage void nmi(void); | |
55 | asmlinkage void int3(void); | |
56 | asmlinkage void overflow(void); | |
57 | asmlinkage void bounds(void); | |
58 | asmlinkage void invalid_op(void); | |
59 | asmlinkage void device_not_available(void); | |
60 | asmlinkage void double_fault(void); | |
61 | asmlinkage void coprocessor_segment_overrun(void); | |
62 | asmlinkage void invalid_TSS(void); | |
63 | asmlinkage void segment_not_present(void); | |
64 | asmlinkage void stack_segment(void); | |
65 | asmlinkage void general_protection(void); | |
66 | asmlinkage void page_fault(void); | |
67 | asmlinkage void coprocessor_error(void); | |
68 | asmlinkage void simd_coprocessor_error(void); | |
69 | asmlinkage void reserved(void); | |
70 | asmlinkage void alignment_check(void); | |
71 | asmlinkage void machine_check(void); | |
72 | asmlinkage void spurious_interrupt_bug(void); | |
1da177e4 LT |
73 | |
74 | struct notifier_block *die_chain; | |
75 | static DEFINE_SPINLOCK(die_notifier_lock); | |
76 | ||
77 | int register_die_notifier(struct notifier_block *nb) | |
78 | { | |
79 | int err = 0; | |
80 | unsigned long flags; | |
81 | spin_lock_irqsave(&die_notifier_lock, flags); | |
82 | err = notifier_chain_register(&die_chain, nb); | |
83 | spin_unlock_irqrestore(&die_notifier_lock, flags); | |
84 | return err; | |
85 | } | |
86 | ||
87 | static inline void conditional_sti(struct pt_regs *regs) | |
88 | { | |
89 | if (regs->eflags & X86_EFLAGS_IF) | |
90 | local_irq_enable(); | |
91 | } | |
92 | ||
93 | static int kstack_depth_to_print = 10; | |
94 | ||
95 | #ifdef CONFIG_KALLSYMS | |
96 | #include <linux/kallsyms.h> | |
97 | int printk_address(unsigned long address) | |
98 | { | |
99 | unsigned long offset = 0, symsize; | |
100 | const char *symname; | |
101 | char *modname; | |
102 | char *delim = ":"; | |
103 | char namebuf[128]; | |
104 | ||
105 | symname = kallsyms_lookup(address, &symsize, &offset, &modname, namebuf); | |
106 | if (!symname) | |
107 | return printk("[<%016lx>]", address); | |
108 | if (!modname) | |
109 | modname = delim = ""; | |
110 | return printk("<%016lx>{%s%s%s%s%+ld}", | |
111 | address,delim,modname,delim,symname,offset); | |
112 | } | |
113 | #else | |
114 | int printk_address(unsigned long address) | |
115 | { | |
116 | return printk("[<%016lx>]", address); | |
117 | } | |
118 | #endif | |
119 | ||
0a658002 AK |
120 | static unsigned long *in_exception_stack(unsigned cpu, unsigned long stack, |
121 | unsigned *usedp, const char **idp) | |
122 | { | |
b556b35e | 123 | static char ids[][8] = { |
0a658002 AK |
124 | [DEBUG_STACK - 1] = "#DB", |
125 | [NMI_STACK - 1] = "NMI", | |
126 | [DOUBLEFAULT_STACK - 1] = "#DF", | |
127 | [STACKFAULT_STACK - 1] = "#SS", | |
128 | [MCE_STACK - 1] = "#MC", | |
b556b35e JB |
129 | #if DEBUG_STKSZ > EXCEPTION_STKSZ |
130 | [N_EXCEPTION_STACKS ... N_EXCEPTION_STACKS + DEBUG_STKSZ / EXCEPTION_STKSZ - 2] = "#DB[?]" | |
131 | #endif | |
0a658002 AK |
132 | }; |
133 | unsigned k; | |
1da177e4 | 134 | |
0a658002 AK |
135 | for (k = 0; k < N_EXCEPTION_STACKS; k++) { |
136 | unsigned long end; | |
137 | ||
b556b35e JB |
138 | switch (k + 1) { |
139 | #if DEBUG_STKSZ > EXCEPTION_STKSZ | |
140 | case DEBUG_STACK: | |
df79efde | 141 | end = cpu_pda(cpu)->debugstack + DEBUG_STKSZ; |
b556b35e JB |
142 | break; |
143 | #endif | |
144 | default: | |
145 | end = per_cpu(init_tss, cpu).ist[k]; | |
146 | break; | |
147 | } | |
0a658002 AK |
148 | if (stack >= end) |
149 | continue; | |
150 | if (stack >= end - EXCEPTION_STKSZ) { | |
151 | if (*usedp & (1U << k)) | |
152 | break; | |
153 | *usedp |= 1U << k; | |
154 | *idp = ids[k]; | |
155 | return (unsigned long *)end; | |
156 | } | |
b556b35e JB |
157 | #if DEBUG_STKSZ > EXCEPTION_STKSZ |
158 | if (k == DEBUG_STACK - 1 && stack >= end - DEBUG_STKSZ) { | |
159 | unsigned j = N_EXCEPTION_STACKS - 1; | |
160 | ||
161 | do { | |
162 | ++j; | |
163 | end -= EXCEPTION_STKSZ; | |
164 | ids[j][4] = '1' + (j - N_EXCEPTION_STACKS); | |
165 | } while (stack < end - EXCEPTION_STKSZ); | |
166 | if (*usedp & (1U << j)) | |
167 | break; | |
168 | *usedp |= 1U << j; | |
169 | *idp = ids[j]; | |
170 | return (unsigned long *)end; | |
171 | } | |
172 | #endif | |
1da177e4 LT |
173 | } |
174 | return NULL; | |
0a658002 | 175 | } |
1da177e4 LT |
176 | |
177 | /* | |
178 | * x86-64 can have upto three kernel stacks: | |
179 | * process stack | |
180 | * interrupt stack | |
0a658002 | 181 | * severe exception (double fault, nmi, stack fault, debug, mce) hardware stack |
1da177e4 LT |
182 | */ |
183 | ||
184 | void show_trace(unsigned long *stack) | |
185 | { | |
0a658002 | 186 | const unsigned cpu = safe_smp_processor_id(); |
df79efde | 187 | unsigned long *irqstack_end = (unsigned long *)cpu_pda(cpu)->irqstackptr; |
1da177e4 | 188 | int i; |
0a658002 | 189 | unsigned used = 0; |
1da177e4 LT |
190 | |
191 | printk("\nCall Trace:"); | |
0a658002 AK |
192 | |
193 | #define HANDLE_STACK(cond) \ | |
194 | do while (cond) { \ | |
1b2f6304 | 195 | unsigned long addr = *stack++; \ |
0a658002 | 196 | if (kernel_text_address(addr)) { \ |
1b2f6304 JB |
197 | if (i > 50) { \ |
198 | printk("\n "); \ | |
199 | i = 0; \ | |
200 | } \ | |
201 | else \ | |
202 | i += printk(" "); \ | |
0a658002 AK |
203 | /* \ |
204 | * If the address is either in the text segment of the \ | |
205 | * kernel, or in the region which contains vmalloc'ed \ | |
206 | * memory, it *may* be the address of a calling \ | |
207 | * routine; if so, print it so that someone tracing \ | |
208 | * down the cause of the crash will be able to figure \ | |
209 | * out the call path that was taken. \ | |
210 | */ \ | |
211 | i += printk_address(addr); \ | |
0a658002 AK |
212 | } \ |
213 | } while (0) | |
214 | ||
1b2f6304 | 215 | for(i = 11; ; ) { |
0a658002 AK |
216 | const char *id; |
217 | unsigned long *estack_end; | |
218 | estack_end = in_exception_stack(cpu, (unsigned long)stack, | |
219 | &used, &id); | |
220 | ||
221 | if (estack_end) { | |
1b2f6304 | 222 | i += printk(" <%s>", id); |
0a658002 | 223 | HANDLE_STACK (stack < estack_end); |
1b2f6304 | 224 | i += printk(" <EOE>"); |
0a658002 AK |
225 | stack = (unsigned long *) estack_end[-2]; |
226 | continue; | |
1da177e4 | 227 | } |
0a658002 AK |
228 | if (irqstack_end) { |
229 | unsigned long *irqstack; | |
230 | irqstack = irqstack_end - | |
231 | (IRQSTACKSIZE - 64) / sizeof(*irqstack); | |
232 | ||
233 | if (stack >= irqstack && stack < irqstack_end) { | |
1b2f6304 | 234 | i += printk(" <IRQ>"); |
0a658002 AK |
235 | HANDLE_STACK (stack < irqstack_end); |
236 | stack = (unsigned long *) (irqstack_end[-1]); | |
237 | irqstack_end = NULL; | |
1b2f6304 | 238 | i += printk(" <EOI>"); |
0a658002 | 239 | continue; |
1da177e4 | 240 | } |
1da177e4 | 241 | } |
0a658002 | 242 | break; |
1da177e4 | 243 | } |
0a658002 AK |
244 | |
245 | HANDLE_STACK (((long) stack & (THREAD_SIZE-1)) != 0); | |
246 | #undef HANDLE_STACK | |
1da177e4 LT |
247 | printk("\n"); |
248 | } | |
249 | ||
250 | void show_stack(struct task_struct *tsk, unsigned long * rsp) | |
251 | { | |
252 | unsigned long *stack; | |
253 | int i; | |
254 | const int cpu = safe_smp_processor_id(); | |
df79efde RT |
255 | unsigned long *irqstack_end = (unsigned long *) (cpu_pda(cpu)->irqstackptr); |
256 | unsigned long *irqstack = (unsigned long *) (cpu_pda(cpu)->irqstackptr - IRQSTACKSIZE); | |
1da177e4 LT |
257 | |
258 | // debugging aid: "show_stack(NULL, NULL);" prints the | |
259 | // back trace for this cpu. | |
260 | ||
261 | if (rsp == NULL) { | |
262 | if (tsk) | |
263 | rsp = (unsigned long *)tsk->thread.rsp; | |
264 | else | |
265 | rsp = (unsigned long *)&rsp; | |
266 | } | |
267 | ||
268 | stack = rsp; | |
269 | for(i=0; i < kstack_depth_to_print; i++) { | |
270 | if (stack >= irqstack && stack <= irqstack_end) { | |
271 | if (stack == irqstack_end) { | |
272 | stack = (unsigned long *) (irqstack_end[-1]); | |
273 | printk(" <EOI> "); | |
274 | } | |
275 | } else { | |
276 | if (((long) stack & (THREAD_SIZE-1)) == 0) | |
277 | break; | |
278 | } | |
279 | if (i && ((i % 4) == 0)) | |
280 | printk("\n "); | |
281 | printk("%016lx ", *stack++); | |
35faa714 | 282 | touch_nmi_watchdog(); |
1da177e4 LT |
283 | } |
284 | show_trace((unsigned long *)rsp); | |
285 | } | |
286 | ||
287 | /* | |
288 | * The architecture-independent dump_stack generator | |
289 | */ | |
290 | void dump_stack(void) | |
291 | { | |
292 | unsigned long dummy; | |
293 | show_trace(&dummy); | |
294 | } | |
295 | ||
296 | EXPORT_SYMBOL(dump_stack); | |
297 | ||
298 | void show_registers(struct pt_regs *regs) | |
299 | { | |
300 | int i; | |
76381fee | 301 | int in_kernel = !user_mode(regs); |
1da177e4 LT |
302 | unsigned long rsp; |
303 | const int cpu = safe_smp_processor_id(); | |
df79efde | 304 | struct task_struct *cur = cpu_pda(cpu)->pcurrent; |
1da177e4 LT |
305 | |
306 | rsp = regs->rsp; | |
307 | ||
308 | printk("CPU %d ", cpu); | |
309 | __show_regs(regs); | |
310 | printk("Process %s (pid: %d, threadinfo %p, task %p)\n", | |
e4f17c43 | 311 | cur->comm, cur->pid, task_thread_info(cur), cur); |
1da177e4 LT |
312 | |
313 | /* | |
314 | * When in-kernel, we also print out the stack and code at the | |
315 | * time of the fault.. | |
316 | */ | |
317 | if (in_kernel) { | |
318 | ||
319 | printk("Stack: "); | |
320 | show_stack(NULL, (unsigned long*)rsp); | |
321 | ||
322 | printk("\nCode: "); | |
323 | if(regs->rip < PAGE_OFFSET) | |
324 | goto bad; | |
325 | ||
326 | for(i=0;i<20;i++) | |
327 | { | |
328 | unsigned char c; | |
329 | if(__get_user(c, &((unsigned char*)regs->rip)[i])) { | |
330 | bad: | |
331 | printk(" Bad RIP value."); | |
332 | break; | |
333 | } | |
334 | printk("%02x ", c); | |
335 | } | |
336 | } | |
337 | printk("\n"); | |
338 | } | |
339 | ||
340 | void handle_BUG(struct pt_regs *regs) | |
341 | { | |
342 | struct bug_frame f; | |
5f1d189f JB |
343 | long len; |
344 | const char *prefix = ""; | |
1da177e4 | 345 | |
76381fee | 346 | if (user_mode(regs)) |
1da177e4 | 347 | return; |
77a75333 | 348 | if (__copy_from_user(&f, (const void __user *) regs->rip, |
1da177e4 LT |
349 | sizeof(struct bug_frame))) |
350 | return; | |
049cdefe | 351 | if (f.filename >= 0 || |
1da177e4 LT |
352 | f.ud2[0] != 0x0f || f.ud2[1] != 0x0b) |
353 | return; | |
5f1d189f JB |
354 | len = __strnlen_user((char *)(long)f.filename, PATH_MAX) - 1; |
355 | if (len < 0 || len >= PATH_MAX) | |
049cdefe | 356 | f.filename = (int)(long)"unmapped filename"; |
5f1d189f JB |
357 | else if (len > 50) { |
358 | f.filename += len - 50; | |
359 | prefix = "..."; | |
360 | } | |
1da177e4 | 361 | printk("----------- [cut here ] --------- [please bite here ] ---------\n"); |
5f1d189f | 362 | printk(KERN_ALERT "Kernel BUG at %s%.50s:%d\n", prefix, (char *)(long)f.filename, f.line); |
1da177e4 LT |
363 | } |
364 | ||
4f60fdf6 | 365 | #ifdef CONFIG_BUG |
1da177e4 LT |
366 | void out_of_line_bug(void) |
367 | { | |
368 | BUG(); | |
369 | } | |
4f60fdf6 | 370 | #endif |
1da177e4 LT |
371 | |
372 | static DEFINE_SPINLOCK(die_lock); | |
373 | static int die_owner = -1; | |
374 | ||
1209140c | 375 | unsigned long oops_begin(void) |
1da177e4 | 376 | { |
1209140c JB |
377 | int cpu = safe_smp_processor_id(); |
378 | unsigned long flags; | |
379 | ||
380 | /* racy, but better than risking deadlock. */ | |
381 | local_irq_save(flags); | |
1da177e4 LT |
382 | if (!spin_trylock(&die_lock)) { |
383 | if (cpu == die_owner) | |
384 | /* nested oops. should stop eventually */; | |
385 | else | |
1209140c | 386 | spin_lock(&die_lock); |
1da177e4 | 387 | } |
1209140c | 388 | die_owner = cpu; |
1da177e4 | 389 | console_verbose(); |
1209140c JB |
390 | bust_spinlocks(1); |
391 | return flags; | |
1da177e4 LT |
392 | } |
393 | ||
1209140c | 394 | void oops_end(unsigned long flags) |
1da177e4 LT |
395 | { |
396 | die_owner = -1; | |
1209140c JB |
397 | bust_spinlocks(0); |
398 | spin_unlock_irqrestore(&die_lock, flags); | |
1da177e4 | 399 | if (panic_on_oops) |
1209140c JB |
400 | panic("Oops"); |
401 | } | |
1da177e4 LT |
402 | |
403 | void __die(const char * str, struct pt_regs * regs, long err) | |
404 | { | |
405 | static int die_counter; | |
406 | printk(KERN_EMERG "%s: %04lx [%u] ", str, err & 0xffff,++die_counter); | |
407 | #ifdef CONFIG_PREEMPT | |
408 | printk("PREEMPT "); | |
409 | #endif | |
410 | #ifdef CONFIG_SMP | |
411 | printk("SMP "); | |
412 | #endif | |
413 | #ifdef CONFIG_DEBUG_PAGEALLOC | |
414 | printk("DEBUG_PAGEALLOC"); | |
415 | #endif | |
416 | printk("\n"); | |
6e3f3617 | 417 | notify_die(DIE_OOPS, str, regs, err, current->thread.trap_no, SIGSEGV); |
1da177e4 LT |
418 | show_registers(regs); |
419 | /* Executive summary in case the oops scrolled away */ | |
420 | printk(KERN_ALERT "RIP "); | |
421 | printk_address(regs->rip); | |
422 | printk(" RSP <%016lx>\n", regs->rsp); | |
423 | } | |
424 | ||
425 | void die(const char * str, struct pt_regs * regs, long err) | |
426 | { | |
1209140c JB |
427 | unsigned long flags = oops_begin(); |
428 | ||
1da177e4 LT |
429 | handle_BUG(regs); |
430 | __die(str, regs, err); | |
1209140c | 431 | oops_end(flags); |
1da177e4 LT |
432 | do_exit(SIGSEGV); |
433 | } | |
1da177e4 LT |
434 | |
435 | void die_nmi(char *str, struct pt_regs *regs) | |
436 | { | |
1209140c JB |
437 | unsigned long flags = oops_begin(); |
438 | ||
1da177e4 LT |
439 | /* |
440 | * We are in trouble anyway, lets at least try | |
441 | * to get a message out. | |
442 | */ | |
443 | printk(str, safe_smp_processor_id()); | |
444 | show_registers(regs); | |
445 | if (panic_on_timeout || panic_on_oops) | |
446 | panic("nmi watchdog"); | |
447 | printk("console shuts up ...\n"); | |
1209140c | 448 | oops_end(flags); |
1da177e4 LT |
449 | do_exit(SIGSEGV); |
450 | } | |
451 | ||
0f2fbdcb PP |
452 | static void __kprobes do_trap(int trapnr, int signr, char *str, |
453 | struct pt_regs * regs, long error_code, | |
454 | siginfo_t *info) | |
1da177e4 | 455 | { |
6e3f3617 JB |
456 | struct task_struct *tsk = current; |
457 | ||
1da177e4 LT |
458 | conditional_sti(regs); |
459 | ||
6e3f3617 JB |
460 | tsk->thread.error_code = error_code; |
461 | tsk->thread.trap_no = trapnr; | |
1da177e4 | 462 | |
6e3f3617 | 463 | if (user_mode(regs)) { |
1da177e4 LT |
464 | if (exception_trace && unhandled_signal(tsk, signr)) |
465 | printk(KERN_INFO | |
466 | "%s[%d] trap %s rip:%lx rsp:%lx error:%lx\n", | |
467 | tsk->comm, tsk->pid, str, | |
468 | regs->rip,regs->rsp,error_code); | |
469 | ||
1da177e4 LT |
470 | if (info) |
471 | force_sig_info(signr, info, tsk); | |
472 | else | |
473 | force_sig(signr, tsk); | |
474 | return; | |
475 | } | |
476 | ||
477 | ||
478 | /* kernel trap */ | |
479 | { | |
480 | const struct exception_table_entry *fixup; | |
481 | fixup = search_exception_tables(regs->rip); | |
482 | if (fixup) { | |
483 | regs->rip = fixup->fixup; | |
484 | } else | |
485 | die(str, regs, error_code); | |
486 | return; | |
487 | } | |
488 | } | |
489 | ||
490 | #define DO_ERROR(trapnr, signr, str, name) \ | |
491 | asmlinkage void do_##name(struct pt_regs * regs, long error_code) \ | |
492 | { \ | |
493 | if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \ | |
494 | == NOTIFY_STOP) \ | |
495 | return; \ | |
496 | do_trap(trapnr, signr, str, regs, error_code, NULL); \ | |
497 | } | |
498 | ||
499 | #define DO_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr) \ | |
500 | asmlinkage void do_##name(struct pt_regs * regs, long error_code) \ | |
501 | { \ | |
502 | siginfo_t info; \ | |
503 | info.si_signo = signr; \ | |
504 | info.si_errno = 0; \ | |
505 | info.si_code = sicode; \ | |
506 | info.si_addr = (void __user *)siaddr; \ | |
507 | if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \ | |
508 | == NOTIFY_STOP) \ | |
509 | return; \ | |
510 | do_trap(trapnr, signr, str, regs, error_code, &info); \ | |
511 | } | |
512 | ||
513 | DO_ERROR_INFO( 0, SIGFPE, "divide error", divide_error, FPE_INTDIV, regs->rip) | |
514 | DO_ERROR( 4, SIGSEGV, "overflow", overflow) | |
515 | DO_ERROR( 5, SIGSEGV, "bounds", bounds) | |
100c0e36 | 516 | DO_ERROR_INFO( 6, SIGILL, "invalid opcode", invalid_op, ILL_ILLOPN, regs->rip) |
1da177e4 LT |
517 | DO_ERROR( 7, SIGSEGV, "device not available", device_not_available) |
518 | DO_ERROR( 9, SIGFPE, "coprocessor segment overrun", coprocessor_segment_overrun) | |
519 | DO_ERROR(10, SIGSEGV, "invalid TSS", invalid_TSS) | |
520 | DO_ERROR(11, SIGBUS, "segment not present", segment_not_present) | |
521 | DO_ERROR_INFO(17, SIGBUS, "alignment check", alignment_check, BUS_ADRALN, 0) | |
522 | DO_ERROR(18, SIGSEGV, "reserved", reserved) | |
6fefb0d1 | 523 | DO_ERROR(12, SIGBUS, "stack segment", stack_segment) |
eca37c18 JB |
524 | |
525 | asmlinkage void do_double_fault(struct pt_regs * regs, long error_code) | |
526 | { | |
527 | static const char str[] = "double fault"; | |
528 | struct task_struct *tsk = current; | |
529 | ||
530 | /* Return not checked because double check cannot be ignored */ | |
531 | notify_die(DIE_TRAP, str, regs, error_code, 8, SIGSEGV); | |
532 | ||
533 | tsk->thread.error_code = error_code; | |
534 | tsk->thread.trap_no = 8; | |
535 | ||
536 | /* This is always a kernel trap and never fixable (and thus must | |
537 | never return). */ | |
538 | for (;;) | |
539 | die(str, regs, error_code); | |
540 | } | |
1da177e4 | 541 | |
0f2fbdcb PP |
542 | asmlinkage void __kprobes do_general_protection(struct pt_regs * regs, |
543 | long error_code) | |
1da177e4 | 544 | { |
6e3f3617 JB |
545 | struct task_struct *tsk = current; |
546 | ||
1da177e4 LT |
547 | conditional_sti(regs); |
548 | ||
6e3f3617 JB |
549 | tsk->thread.error_code = error_code; |
550 | tsk->thread.trap_no = 13; | |
1da177e4 | 551 | |
6e3f3617 | 552 | if (user_mode(regs)) { |
1da177e4 LT |
553 | if (exception_trace && unhandled_signal(tsk, SIGSEGV)) |
554 | printk(KERN_INFO | |
555 | "%s[%d] general protection rip:%lx rsp:%lx error:%lx\n", | |
556 | tsk->comm, tsk->pid, | |
557 | regs->rip,regs->rsp,error_code); | |
558 | ||
1da177e4 LT |
559 | force_sig(SIGSEGV, tsk); |
560 | return; | |
561 | } | |
562 | ||
563 | /* kernel gp */ | |
564 | { | |
565 | const struct exception_table_entry *fixup; | |
566 | fixup = search_exception_tables(regs->rip); | |
567 | if (fixup) { | |
568 | regs->rip = fixup->fixup; | |
569 | return; | |
570 | } | |
571 | if (notify_die(DIE_GPF, "general protection fault", regs, | |
572 | error_code, 13, SIGSEGV) == NOTIFY_STOP) | |
573 | return; | |
574 | die("general protection fault", regs, error_code); | |
575 | } | |
576 | } | |
577 | ||
578 | static void mem_parity_error(unsigned char reason, struct pt_regs * regs) | |
579 | { | |
580 | printk("Uhhuh. NMI received. Dazed and confused, but trying to continue\n"); | |
581 | printk("You probably have a hardware problem with your RAM chips\n"); | |
582 | ||
583 | /* Clear and disable the memory parity error line. */ | |
584 | reason = (reason & 0xf) | 4; | |
585 | outb(reason, 0x61); | |
586 | } | |
587 | ||
588 | static void io_check_error(unsigned char reason, struct pt_regs * regs) | |
589 | { | |
590 | printk("NMI: IOCK error (debug interrupt?)\n"); | |
591 | show_registers(regs); | |
592 | ||
593 | /* Re-enable the IOCK line, wait for a few seconds */ | |
594 | reason = (reason & 0xf) | 8; | |
595 | outb(reason, 0x61); | |
596 | mdelay(2000); | |
597 | reason &= ~8; | |
598 | outb(reason, 0x61); | |
599 | } | |
600 | ||
601 | static void unknown_nmi_error(unsigned char reason, struct pt_regs * regs) | |
602 | { printk("Uhhuh. NMI received for unknown reason %02x.\n", reason); | |
603 | printk("Dazed and confused, but trying to continue\n"); | |
604 | printk("Do you have a strange power saving mode enabled?\n"); | |
605 | } | |
606 | ||
6fefb0d1 AK |
607 | /* Runs on IST stack. This code must keep interrupts off all the time. |
608 | Nested NMIs are prevented by the CPU. */ | |
1da177e4 LT |
609 | asmlinkage void default_do_nmi(struct pt_regs *regs) |
610 | { | |
611 | unsigned char reason = 0; | |
76e4f660 AR |
612 | int cpu; |
613 | ||
614 | cpu = smp_processor_id(); | |
1da177e4 LT |
615 | |
616 | /* Only the BSP gets external NMIs from the system. */ | |
76e4f660 | 617 | if (!cpu) |
1da177e4 LT |
618 | reason = get_nmi_reason(); |
619 | ||
620 | if (!(reason & 0xc0)) { | |
6e3f3617 | 621 | if (notify_die(DIE_NMI_IPI, "nmi_ipi", regs, reason, 2, SIGINT) |
1da177e4 LT |
622 | == NOTIFY_STOP) |
623 | return; | |
624 | #ifdef CONFIG_X86_LOCAL_APIC | |
625 | /* | |
626 | * Ok, so this is none of the documented NMI sources, | |
627 | * so it must be the NMI watchdog. | |
628 | */ | |
629 | if (nmi_watchdog > 0) { | |
630 | nmi_watchdog_tick(regs,reason); | |
631 | return; | |
632 | } | |
633 | #endif | |
634 | unknown_nmi_error(reason, regs); | |
635 | return; | |
636 | } | |
6e3f3617 | 637 | if (notify_die(DIE_NMI, "nmi", regs, reason, 2, SIGINT) == NOTIFY_STOP) |
1da177e4 LT |
638 | return; |
639 | ||
640 | /* AK: following checks seem to be broken on modern chipsets. FIXME */ | |
641 | ||
642 | if (reason & 0x80) | |
643 | mem_parity_error(reason, regs); | |
644 | if (reason & 0x40) | |
645 | io_check_error(reason, regs); | |
646 | } | |
647 | ||
b556b35e | 648 | /* runs on IST stack. */ |
0f2fbdcb | 649 | asmlinkage void __kprobes do_int3(struct pt_regs * regs, long error_code) |
1da177e4 LT |
650 | { |
651 | if (notify_die(DIE_INT3, "int3", regs, error_code, 3, SIGTRAP) == NOTIFY_STOP) { | |
652 | return; | |
653 | } | |
654 | do_trap(3, SIGTRAP, "int3", regs, error_code, NULL); | |
655 | return; | |
656 | } | |
657 | ||
6fefb0d1 AK |
658 | /* Help handler running on IST stack to switch back to user stack |
659 | for scheduling or signal handling. The actual stack switch is done in | |
660 | entry.S */ | |
661 | asmlinkage struct pt_regs *sync_regs(struct pt_regs *eregs) | |
662 | { | |
663 | struct pt_regs *regs = eregs; | |
664 | /* Did already sync */ | |
665 | if (eregs == (struct pt_regs *)eregs->rsp) | |
666 | ; | |
667 | /* Exception from user space */ | |
76381fee | 668 | else if (user_mode(eregs)) |
bb049232 | 669 | regs = task_pt_regs(current); |
6fefb0d1 AK |
670 | /* Exception from kernel and interrupts are enabled. Move to |
671 | kernel process stack. */ | |
672 | else if (eregs->eflags & X86_EFLAGS_IF) | |
673 | regs = (struct pt_regs *)(eregs->rsp -= sizeof(struct pt_regs)); | |
674 | if (eregs != regs) | |
675 | *regs = *eregs; | |
676 | return regs; | |
677 | } | |
678 | ||
1da177e4 | 679 | /* runs on IST stack. */ |
0f2fbdcb PP |
680 | asmlinkage void __kprobes do_debug(struct pt_regs * regs, |
681 | unsigned long error_code) | |
1da177e4 | 682 | { |
1da177e4 LT |
683 | unsigned long condition; |
684 | struct task_struct *tsk = current; | |
685 | siginfo_t info; | |
686 | ||
e9129e56 | 687 | get_debugreg(condition, 6); |
1da177e4 LT |
688 | |
689 | if (notify_die(DIE_DEBUG, "debug", regs, condition, error_code, | |
daeeafec | 690 | SIGTRAP) == NOTIFY_STOP) |
6fefb0d1 | 691 | return; |
daeeafec | 692 | |
1da177e4 LT |
693 | conditional_sti(regs); |
694 | ||
695 | /* Mask out spurious debug traps due to lazy DR7 setting */ | |
696 | if (condition & (DR_TRAP0|DR_TRAP1|DR_TRAP2|DR_TRAP3)) { | |
697 | if (!tsk->thread.debugreg7) { | |
698 | goto clear_dr7; | |
699 | } | |
700 | } | |
701 | ||
702 | tsk->thread.debugreg6 = condition; | |
703 | ||
704 | /* Mask out spurious TF errors due to lazy TF clearing */ | |
daeeafec | 705 | if (condition & DR_STEP) { |
1da177e4 LT |
706 | /* |
707 | * The TF error should be masked out only if the current | |
708 | * process is not traced and if the TRAP flag has been set | |
709 | * previously by a tracing process (condition detected by | |
710 | * the PT_DTRACE flag); remember that the i386 TRAP flag | |
711 | * can be modified by the process itself in user mode, | |
712 | * allowing programs to debug themselves without the ptrace() | |
713 | * interface. | |
714 | */ | |
76381fee | 715 | if (!user_mode(regs)) |
1da177e4 | 716 | goto clear_TF_reenable; |
be61bff7 AK |
717 | /* |
718 | * Was the TF flag set by a debugger? If so, clear it now, | |
719 | * so that register information is correct. | |
720 | */ | |
721 | if (tsk->ptrace & PT_DTRACE) { | |
722 | regs->eflags &= ~TF_MASK; | |
723 | tsk->ptrace &= ~PT_DTRACE; | |
724 | } | |
1da177e4 LT |
725 | } |
726 | ||
727 | /* Ok, finally something we can handle */ | |
728 | tsk->thread.trap_no = 1; | |
729 | tsk->thread.error_code = error_code; | |
730 | info.si_signo = SIGTRAP; | |
731 | info.si_errno = 0; | |
732 | info.si_code = TRAP_BRKPT; | |
01b8faae JB |
733 | info.si_addr = user_mode(regs) ? (void __user *)regs->rip : NULL; |
734 | force_sig_info(SIGTRAP, &info, tsk); | |
1da177e4 | 735 | |
1da177e4 | 736 | clear_dr7: |
e9129e56 | 737 | set_debugreg(0UL, 7); |
6fefb0d1 | 738 | return; |
1da177e4 LT |
739 | |
740 | clear_TF_reenable: | |
741 | set_tsk_thread_flag(tsk, TIF_SINGLESTEP); | |
1da177e4 | 742 | regs->eflags &= ~TF_MASK; |
1da177e4 LT |
743 | } |
744 | ||
6e3f3617 | 745 | static int kernel_math_error(struct pt_regs *regs, const char *str, int trapnr) |
1da177e4 LT |
746 | { |
747 | const struct exception_table_entry *fixup; | |
748 | fixup = search_exception_tables(regs->rip); | |
749 | if (fixup) { | |
750 | regs->rip = fixup->fixup; | |
751 | return 1; | |
752 | } | |
6e3f3617 | 753 | notify_die(DIE_GPF, str, regs, 0, trapnr, SIGFPE); |
3a848f63 | 754 | /* Illegal floating point operation in the kernel */ |
6e3f3617 | 755 | current->thread.trap_no = trapnr; |
1da177e4 | 756 | die(str, regs, 0); |
1da177e4 LT |
757 | return 0; |
758 | } | |
759 | ||
760 | /* | |
761 | * Note that we play around with the 'TS' bit in an attempt to get | |
762 | * the correct behaviour even in the presence of the asynchronous | |
763 | * IRQ13 behaviour | |
764 | */ | |
765 | asmlinkage void do_coprocessor_error(struct pt_regs *regs) | |
766 | { | |
767 | void __user *rip = (void __user *)(regs->rip); | |
768 | struct task_struct * task; | |
769 | siginfo_t info; | |
770 | unsigned short cwd, swd; | |
771 | ||
772 | conditional_sti(regs); | |
76381fee | 773 | if (!user_mode(regs) && |
6e3f3617 | 774 | kernel_math_error(regs, "kernel x87 math error", 16)) |
1da177e4 LT |
775 | return; |
776 | ||
777 | /* | |
778 | * Save the info for the exception handler and clear the error. | |
779 | */ | |
780 | task = current; | |
781 | save_init_fpu(task); | |
782 | task->thread.trap_no = 16; | |
783 | task->thread.error_code = 0; | |
784 | info.si_signo = SIGFPE; | |
785 | info.si_errno = 0; | |
786 | info.si_code = __SI_FAULT; | |
787 | info.si_addr = rip; | |
788 | /* | |
789 | * (~cwd & swd) will mask out exceptions that are not set to unmasked | |
790 | * status. 0x3f is the exception bits in these regs, 0x200 is the | |
791 | * C1 reg you need in case of a stack fault, 0x040 is the stack | |
792 | * fault bit. We should only be taking one exception at a time, | |
793 | * so if this combination doesn't produce any single exception, | |
794 | * then we have a bad program that isn't synchronizing its FPU usage | |
795 | * and it will suffer the consequences since we won't be able to | |
796 | * fully reproduce the context of the exception | |
797 | */ | |
798 | cwd = get_fpu_cwd(task); | |
799 | swd = get_fpu_swd(task); | |
ff347b22 | 800 | switch (swd & ~cwd & 0x3f) { |
1da177e4 LT |
801 | case 0x000: |
802 | default: | |
803 | break; | |
804 | case 0x001: /* Invalid Op */ | |
ff347b22 CE |
805 | /* |
806 | * swd & 0x240 == 0x040: Stack Underflow | |
807 | * swd & 0x240 == 0x240: Stack Overflow | |
808 | * User must clear the SF bit (0x40) if set | |
809 | */ | |
1da177e4 LT |
810 | info.si_code = FPE_FLTINV; |
811 | break; | |
812 | case 0x002: /* Denormalize */ | |
813 | case 0x010: /* Underflow */ | |
814 | info.si_code = FPE_FLTUND; | |
815 | break; | |
816 | case 0x004: /* Zero Divide */ | |
817 | info.si_code = FPE_FLTDIV; | |
818 | break; | |
819 | case 0x008: /* Overflow */ | |
820 | info.si_code = FPE_FLTOVF; | |
821 | break; | |
822 | case 0x020: /* Precision */ | |
823 | info.si_code = FPE_FLTRES; | |
824 | break; | |
825 | } | |
826 | force_sig_info(SIGFPE, &info, task); | |
827 | } | |
828 | ||
829 | asmlinkage void bad_intr(void) | |
830 | { | |
831 | printk("bad interrupt"); | |
832 | } | |
833 | ||
834 | asmlinkage void do_simd_coprocessor_error(struct pt_regs *regs) | |
835 | { | |
836 | void __user *rip = (void __user *)(regs->rip); | |
837 | struct task_struct * task; | |
838 | siginfo_t info; | |
839 | unsigned short mxcsr; | |
840 | ||
841 | conditional_sti(regs); | |
76381fee | 842 | if (!user_mode(regs) && |
6e3f3617 | 843 | kernel_math_error(regs, "kernel simd math error", 19)) |
1da177e4 LT |
844 | return; |
845 | ||
846 | /* | |
847 | * Save the info for the exception handler and clear the error. | |
848 | */ | |
849 | task = current; | |
850 | save_init_fpu(task); | |
851 | task->thread.trap_no = 19; | |
852 | task->thread.error_code = 0; | |
853 | info.si_signo = SIGFPE; | |
854 | info.si_errno = 0; | |
855 | info.si_code = __SI_FAULT; | |
856 | info.si_addr = rip; | |
857 | /* | |
858 | * The SIMD FPU exceptions are handled a little differently, as there | |
859 | * is only a single status/control register. Thus, to determine which | |
860 | * unmasked exception was caught we must mask the exception mask bits | |
861 | * at 0x1f80, and then use these to mask the exception bits at 0x3f. | |
862 | */ | |
863 | mxcsr = get_fpu_mxcsr(task); | |
864 | switch (~((mxcsr & 0x1f80) >> 7) & (mxcsr & 0x3f)) { | |
865 | case 0x000: | |
866 | default: | |
867 | break; | |
868 | case 0x001: /* Invalid Op */ | |
869 | info.si_code = FPE_FLTINV; | |
870 | break; | |
871 | case 0x002: /* Denormalize */ | |
872 | case 0x010: /* Underflow */ | |
873 | info.si_code = FPE_FLTUND; | |
874 | break; | |
875 | case 0x004: /* Zero Divide */ | |
876 | info.si_code = FPE_FLTDIV; | |
877 | break; | |
878 | case 0x008: /* Overflow */ | |
879 | info.si_code = FPE_FLTOVF; | |
880 | break; | |
881 | case 0x020: /* Precision */ | |
882 | info.si_code = FPE_FLTRES; | |
883 | break; | |
884 | } | |
885 | force_sig_info(SIGFPE, &info, task); | |
886 | } | |
887 | ||
888 | asmlinkage void do_spurious_interrupt_bug(struct pt_regs * regs) | |
889 | { | |
890 | } | |
891 | ||
892 | asmlinkage void __attribute__((weak)) smp_thermal_interrupt(void) | |
89b831ef JS |
893 | { |
894 | } | |
895 | ||
896 | asmlinkage void __attribute__((weak)) mce_threshold_interrupt(void) | |
1da177e4 LT |
897 | { |
898 | } | |
899 | ||
900 | /* | |
901 | * 'math_state_restore()' saves the current math information in the | |
902 | * old math state array, and gets the new ones from the current task | |
903 | * | |
904 | * Careful.. There are problems with IBM-designed IRQ13 behaviour. | |
905 | * Don't touch unless you *really* know how it works. | |
906 | */ | |
907 | asmlinkage void math_state_restore(void) | |
908 | { | |
909 | struct task_struct *me = current; | |
910 | clts(); /* Allow maths ops (or we recurse) */ | |
911 | ||
912 | if (!used_math()) | |
913 | init_fpu(me); | |
914 | restore_fpu_checking(&me->thread.i387.fxsave); | |
e4f17c43 | 915 | task_thread_info(me)->status |= TS_USEDFPU; |
1da177e4 LT |
916 | } |
917 | ||
1da177e4 LT |
918 | void __init trap_init(void) |
919 | { | |
920 | set_intr_gate(0,÷_error); | |
921 | set_intr_gate_ist(1,&debug,DEBUG_STACK); | |
922 | set_intr_gate_ist(2,&nmi,NMI_STACK); | |
b556b35e | 923 | set_system_gate_ist(3,&int3,DEBUG_STACK); /* int3 can be called from all */ |
0a521588 JB |
924 | set_system_gate(4,&overflow); /* int4 can be called from all */ |
925 | set_intr_gate(5,&bounds); | |
1da177e4 LT |
926 | set_intr_gate(6,&invalid_op); |
927 | set_intr_gate(7,&device_not_available); | |
928 | set_intr_gate_ist(8,&double_fault, DOUBLEFAULT_STACK); | |
929 | set_intr_gate(9,&coprocessor_segment_overrun); | |
930 | set_intr_gate(10,&invalid_TSS); | |
931 | set_intr_gate(11,&segment_not_present); | |
932 | set_intr_gate_ist(12,&stack_segment,STACKFAULT_STACK); | |
933 | set_intr_gate(13,&general_protection); | |
934 | set_intr_gate(14,&page_fault); | |
935 | set_intr_gate(15,&spurious_interrupt_bug); | |
936 | set_intr_gate(16,&coprocessor_error); | |
937 | set_intr_gate(17,&alignment_check); | |
938 | #ifdef CONFIG_X86_MCE | |
939 | set_intr_gate_ist(18,&machine_check, MCE_STACK); | |
940 | #endif | |
941 | set_intr_gate(19,&simd_coprocessor_error); | |
942 | ||
943 | #ifdef CONFIG_IA32_EMULATION | |
944 | set_system_gate(IA32_SYSCALL_VECTOR, ia32_syscall); | |
945 | #endif | |
946 | ||
1da177e4 LT |
947 | /* |
948 | * Should be a barrier for any external CPU state. | |
949 | */ | |
950 | cpu_init(); | |
951 | } | |
952 | ||
953 | ||
954 | /* Actual parsing is done early in setup.c. */ | |
955 | static int __init oops_dummy(char *s) | |
956 | { | |
957 | panic_on_oops = 1; | |
958 | return -1; | |
959 | } | |
960 | __setup("oops=", oops_dummy); | |
961 | ||
962 | static int __init kstack_setup(char *s) | |
963 | { | |
964 | kstack_depth_to_print = simple_strtoul(s,NULL,0); | |
965 | return 0; | |
966 | } | |
967 | __setup("kstack=", kstack_setup); | |
968 |