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[PATCH] x86_64: Removing unused function die_if_kernel().
[deliverable/linux.git] / arch / x86_64 / kernel / traps.c
CommitLineData
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		 50extern struct gate_struct idt_table[256];
51
52asmlinkage void divide_error(void);
53asmlinkage void debug(void);
54asmlinkage void nmi(void);
55asmlinkage void int3(void);
56asmlinkage void overflow(void);
57asmlinkage void bounds(void);
58asmlinkage void invalid_op(void);
59asmlinkage void device_not_available(void);
60asmlinkage void double_fault(void);
61asmlinkage void coprocessor_segment_overrun(void);
62asmlinkage void invalid_TSS(void);
63asmlinkage void segment_not_present(void);
64asmlinkage void stack_segment(void);
65asmlinkage void general_protection(void);
66asmlinkage void page_fault(void);
67asmlinkage void coprocessor_error(void);
68asmlinkage void simd_coprocessor_error(void);
69asmlinkage void reserved(void);
70asmlinkage void alignment_check(void);
71asmlinkage void machine_check(void);
72asmlinkage void spurious_interrupt_bug(void);
73asmlinkage void call_debug(void);
74
75struct notifier_block *die_chain;
76static DEFINE_SPINLOCK(die_notifier_lock);
77
78int register_die_notifier(struct notifier_block *nb)
79{
80 int err = 0;
81 unsigned long flags;
82 spin_lock_irqsave(&die_notifier_lock, flags);
83 err = notifier_chain_register(&die_chain, nb);
84 spin_unlock_irqrestore(&die_notifier_lock, flags);
85 return err;
86}
87
88static inline void conditional_sti(struct pt_regs *regs)
89{
90 if (regs->eflags & X86_EFLAGS_IF)
91 local_irq_enable();
92}
93
94static int kstack_depth_to_print = 10;
95
96#ifdef CONFIG_KALLSYMS
97#include <linux/kallsyms.h>
98int printk_address(unsigned long address)
99{
100 unsigned long offset = 0, symsize;
101 const char *symname;
102 char *modname;
103 char *delim = ":";
104 char namebuf[128];
105
106 symname = kallsyms_lookup(address, &symsize, &offset, &modname, namebuf);
107 if (!symname)
108 return printk("[<%016lx>]", address);
109 if (!modname)
110 modname = delim = "";
111 return printk("<%016lx>{%s%s%s%s%+ld}",
112 address,delim,modname,delim,symname,offset);
113}
114#else
115int printk_address(unsigned long address)
116{
117 return printk("[<%016lx>]", address);
118}
119#endif
120
0a658002
AK		 121static unsigned long *in_exception_stack(unsigned cpu, unsigned long stack,
122 unsigned *usedp, const char **idp)
123{
124 static const char ids[N_EXCEPTION_STACKS][8] = {
125 [DEBUG_STACK - 1] = "#DB",
126 [NMI_STACK - 1] = "NMI",
127 [DOUBLEFAULT_STACK - 1] = "#DF",
128 [STACKFAULT_STACK - 1] = "#SS",
129 [MCE_STACK - 1] = "#MC",
130 };
131 unsigned k;
1da177e4 132
0a658002
AK		 133 for (k = 0; k < N_EXCEPTION_STACKS; k++) {
134 unsigned long end;
135
136 end = per_cpu(init_tss, cpu).ist[k];
137 if (stack >= end)
138 continue;
139 if (stack >= end - EXCEPTION_STKSZ) {
140 if (*usedp & (1U << k))
141 break;
142 *usedp |= 1U << k;
143 *idp = ids[k];
144 return (unsigned long *)end;
145 }
1da177e4
LT		 146 }
147 return NULL;
0a658002 148}
1da177e4
LT		 149
150/*
151 * x86-64 can have upto three kernel stacks:
152 * process stack
153 * interrupt stack
0a658002 154 * severe exception (double fault, nmi, stack fault, debug, mce) hardware stack
1da177e4
LT		 155 */
156
157void show_trace(unsigned long *stack)
158{
159 unsigned long addr;
0a658002
AK		 160 const unsigned cpu = safe_smp_processor_id();
161 unsigned long *irqstack_end = (unsigned long *)cpu_pda[cpu].irqstackptr;
1da177e4 162 int i;
0a658002 163 unsigned used = 0;
1da177e4
LT		 164
165 printk("\nCall Trace:");
0a658002
AK		 166
167#define HANDLE_STACK(cond) \
168 do while (cond) { \
169 addr = *stack++; \
170 if (kernel_text_address(addr)) { \
171 /* \
172 * If the address is either in the text segment of the \
173 * kernel, or in the region which contains vmalloc'ed \
174 * memory, it *may* be the address of a calling \
175 * routine; if so, print it so that someone tracing \
176 * down the cause of the crash will be able to figure \
177 * out the call path that was taken. \
178 */ \
179 i += printk_address(addr); \
180 if (i > 50) { \
181 printk("\n "); \
182 i = 0; \
183 } \
184 else \
185 i += printk(" "); \
186 } \
187 } while (0)
188
189 for(i = 0; ; ) {
190 const char *id;
191 unsigned long *estack_end;
192 estack_end = in_exception_stack(cpu, (unsigned long)stack,
193 &used, &id);
194
195 if (estack_end) {
196 i += printk(" <%s> ", id);
197 HANDLE_STACK (stack < estack_end);
198 i += printk(" <EOE> ");
199 stack = (unsigned long *) estack_end[-2];
200 continue;
1da177e4 201 }
0a658002
AK		 202 if (irqstack_end) {
203 unsigned long *irqstack;
204 irqstack = irqstack_end -
205 (IRQSTACKSIZE - 64) / sizeof(*irqstack);
206
207 if (stack >= irqstack && stack < irqstack_end) {
208 i += printk(" <IRQ> ");
209 HANDLE_STACK (stack < irqstack_end);
210 stack = (unsigned long *) (irqstack_end[-1]);
211 irqstack_end = NULL;
212 i += printk(" <EOI> ");
213 continue;
1da177e4 214 }
1da177e4 215 }
0a658002 216 break;
1da177e4 217 }
0a658002
AK		 218
219 HANDLE_STACK (((long) stack & (THREAD_SIZE-1)) != 0);
220#undef HANDLE_STACK
1da177e4
LT		 221 printk("\n");
222}
223
224void show_stack(struct task_struct *tsk, unsigned long * rsp)
225{
226 unsigned long *stack;
227 int i;
228 const int cpu = safe_smp_processor_id();
229 unsigned long *irqstack_end = (unsigned long *) (cpu_pda[cpu].irqstackptr);
230 unsigned long *irqstack = (unsigned long *) (cpu_pda[cpu].irqstackptr - IRQSTACKSIZE);
231
232 // debugging aid: "show_stack(NULL, NULL);" prints the
233 // back trace for this cpu.
234
235 if (rsp == NULL) {
236 if (tsk)
237 rsp = (unsigned long *)tsk->thread.rsp;
238 else
239 rsp = (unsigned long *)&rsp;
240 }
241
242 stack = rsp;
243 for(i=0; i < kstack_depth_to_print; i++) {
244 if (stack >= irqstack && stack <= irqstack_end) {
245 if (stack == irqstack_end) {
246 stack = (unsigned long *) (irqstack_end[-1]);
247 printk(" <EOI> ");
248 }
249 } else {
250 if (((long) stack & (THREAD_SIZE-1)) == 0)
251 break;
252 }
253 if (i && ((i % 4) == 0))
254 printk("\n ");
255 printk("%016lx ", *stack++);
35faa714 256 touch_nmi_watchdog();
1da177e4
LT		 257 }
258 show_trace((unsigned long *)rsp);
259}
260
261/*
262 * The architecture-independent dump_stack generator
263 */
264void dump_stack(void)
265{
266 unsigned long dummy;
267 show_trace(&dummy);
268}
269
270EXPORT_SYMBOL(dump_stack);
271
272void show_registers(struct pt_regs *regs)
273{
274 int i;
76381fee 275 int in_kernel = !user_mode(regs);
1da177e4
LT		 276 unsigned long rsp;
277 const int cpu = safe_smp_processor_id();
278 struct task_struct *cur = cpu_pda[cpu].pcurrent;
279
280 rsp = regs->rsp;
281
282 printk("CPU %d ", cpu);
283 __show_regs(regs);
284 printk("Process %s (pid: %d, threadinfo %p, task %p)\n",
285 cur->comm, cur->pid, cur->thread_info, cur);
286
287 /*
288 * When in-kernel, we also print out the stack and code at the
289 * time of the fault..
290 */
291 if (in_kernel) {
292
293 printk("Stack: ");
294 show_stack(NULL, (unsigned long*)rsp);
295
296 printk("\nCode: ");
297 if(regs->rip < PAGE_OFFSET)
298 goto bad;
299
300 for(i=0;i<20;i++)
301 {
302 unsigned char c;
303 if(__get_user(c, &((unsigned char*)regs->rip)[i])) {
304bad:
305 printk(" Bad RIP value.");
306 break;
307 }
308 printk("%02x ", c);
309 }
310 }
311 printk("\n");
312}
313
314void handle_BUG(struct pt_regs *regs)
315{
316 struct bug_frame f;
317 char tmp;
318
76381fee 319 if (user_mode(regs))
1da177e4
LT		 320 return;
321 if (__copy_from_user(&f, (struct bug_frame *) regs->rip,
322 sizeof(struct bug_frame)))
323 return;
049cdefe 324 if (f.filename >= 0 ||
1da177e4
LT		 325 f.ud2[0] != 0x0f || f.ud2[1] != 0x0b)
326 return;
049cdefe
JB		 327 if (__get_user(tmp, (char *)(long)f.filename))
328 f.filename = (int)(long)"unmapped filename";
1da177e4 329 printk("----------- [cut here ] --------- [please bite here ] ---------\n");
049cdefe 330 printk(KERN_ALERT "Kernel BUG at %.50s:%d\n", (char *)(long)f.filename, f.line);
1da177e4
LT		 331}
332
4f60fdf6 333#ifdef CONFIG_BUG
1da177e4
LT		 334void out_of_line_bug(void)
335{
336 BUG();
337}
4f60fdf6 338#endif
1da177e4
LT		 339
340static DEFINE_SPINLOCK(die_lock);
341static int die_owner = -1;
342
1209140c 343unsigned long oops_begin(void)
1da177e4 344{
1209140c
JB		 345 int cpu = safe_smp_processor_id();
346 unsigned long flags;
347
348 /* racy, but better than risking deadlock. */
349 local_irq_save(flags);
1da177e4
LT		 350 if (!spin_trylock(&die_lock)) {
351 if (cpu == die_owner)
352 /* nested oops. should stop eventually */;
353 else
1209140c 354 spin_lock(&die_lock);
1da177e4 355 }
1209140c 356 die_owner = cpu;
1da177e4 357 console_verbose();
1209140c
JB		 358 bust_spinlocks(1);
359 return flags;
1da177e4
LT		 360}
361
1209140c 362void oops_end(unsigned long flags)
1da177e4
LT		 363{
364 die_owner = -1;
1209140c
JB		 365 bust_spinlocks(0);
366 spin_unlock_irqrestore(&die_lock, flags);
1da177e4 367 if (panic_on_oops)
1209140c
JB		 368 panic("Oops");
369}
1da177e4
LT		 370
371void __die(const char * str, struct pt_regs * regs, long err)
372{
373 static int die_counter;
374 printk(KERN_EMERG "%s: %04lx [%u] ", str, err & 0xffff,++die_counter);
375#ifdef CONFIG_PREEMPT
376 printk("PREEMPT ");
377#endif
378#ifdef CONFIG_SMP
379 printk("SMP ");
380#endif
381#ifdef CONFIG_DEBUG_PAGEALLOC
382 printk("DEBUG_PAGEALLOC");
383#endif
384 printk("\n");
385 notify_die(DIE_OOPS, (char *)str, regs, err, 255, SIGSEGV);
386 show_registers(regs);
387 /* Executive summary in case the oops scrolled away */
388 printk(KERN_ALERT "RIP ");
389 printk_address(regs->rip);
390 printk(" RSP <%016lx>\n", regs->rsp);
391}
392
393void die(const char * str, struct pt_regs * regs, long err)
394{
1209140c
JB		 395 unsigned long flags = oops_begin();
396
1da177e4
LT		 397 handle_BUG(regs);
398 __die(str, regs, err);
1209140c 399 oops_end(flags);
1da177e4
LT		 400 do_exit(SIGSEGV);
401}
1da177e4
LT		 402
403void die_nmi(char *str, struct pt_regs *regs)
404{
1209140c
JB		 405 unsigned long flags = oops_begin();
406
1da177e4
LT		 407 /*
408 * We are in trouble anyway, lets at least try
409 * to get a message out.
410 */
411 printk(str, safe_smp_processor_id());
412 show_registers(regs);
413 if (panic_on_timeout || panic_on_oops)
414 panic("nmi watchdog");
415 printk("console shuts up ...\n");
1209140c 416 oops_end(flags);
1da177e4
LT		 417 do_exit(SIGSEGV);
418}
419
0f2fbdcb
PP		 420static void __kprobes do_trap(int trapnr, int signr, char *str,
421 struct pt_regs * regs, long error_code,
422 siginfo_t *info)
1da177e4
LT		 423{
424 conditional_sti(regs);
425
76381fee 426 if (user_mode(regs)) {
1da177e4
LT		 427 struct task_struct *tsk = current;
428
429 if (exception_trace && unhandled_signal(tsk, signr))
430 printk(KERN_INFO
431 "%s[%d] trap %s rip:%lx rsp:%lx error:%lx\n",
432 tsk->comm, tsk->pid, str,
433 regs->rip,regs->rsp,error_code);
434
435 tsk->thread.error_code = error_code;
436 tsk->thread.trap_no = trapnr;
437 if (info)
438 force_sig_info(signr, info, tsk);
439 else
440 force_sig(signr, tsk);
441 return;
442 }
443
444
445 /* kernel trap */
446 {
447 const struct exception_table_entry *fixup;
448 fixup = search_exception_tables(regs->rip);
449 if (fixup) {
450 regs->rip = fixup->fixup;
451 } else
452 die(str, regs, error_code);
453 return;
454 }
455}
456
457#define DO_ERROR(trapnr, signr, str, name) \
458asmlinkage void do_##name(struct pt_regs * regs, long error_code) \
459{ \
460 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
461 == NOTIFY_STOP) \
462 return; \
463 do_trap(trapnr, signr, str, regs, error_code, NULL); \
464}
465
466#define DO_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr) \
467asmlinkage void do_##name(struct pt_regs * regs, long error_code) \
468{ \
469 siginfo_t info; \
470 info.si_signo = signr; \
471 info.si_errno = 0; \
472 info.si_code = sicode; \
473 info.si_addr = (void __user *)siaddr; \
474 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
475 == NOTIFY_STOP) \
476 return; \
477 do_trap(trapnr, signr, str, regs, error_code, &info); \
478}
479
480DO_ERROR_INFO( 0, SIGFPE, "divide error", divide_error, FPE_INTDIV, regs->rip)
481DO_ERROR( 4, SIGSEGV, "overflow", overflow)
482DO_ERROR( 5, SIGSEGV, "bounds", bounds)
483DO_ERROR_INFO( 6, SIGILL, "invalid operand", invalid_op, ILL_ILLOPN, regs->rip)
484DO_ERROR( 7, SIGSEGV, "device not available", device_not_available)
485DO_ERROR( 9, SIGFPE, "coprocessor segment overrun", coprocessor_segment_overrun)
486DO_ERROR(10, SIGSEGV, "invalid TSS", invalid_TSS)
487DO_ERROR(11, SIGBUS, "segment not present", segment_not_present)
488DO_ERROR_INFO(17, SIGBUS, "alignment check", alignment_check, BUS_ADRALN, 0)
489DO_ERROR(18, SIGSEGV, "reserved", reserved)
6fefb0d1
AK		 490DO_ERROR(12, SIGBUS, "stack segment", stack_segment)
491DO_ERROR( 8, SIGSEGV, "double fault", double_fault)
1da177e4 492
0f2fbdcb
PP		 493asmlinkage void __kprobes do_general_protection(struct pt_regs * regs,
494 long error_code)
1da177e4
LT		 495{
496 conditional_sti(regs);
497
76381fee 498 if (user_mode(regs)) {
1da177e4
LT		 499 struct task_struct *tsk = current;
500
501 if (exception_trace && unhandled_signal(tsk, SIGSEGV))
502 printk(KERN_INFO
503 "%s[%d] general protection rip:%lx rsp:%lx error:%lx\n",
504 tsk->comm, tsk->pid,
505 regs->rip,regs->rsp,error_code);
506
507 tsk->thread.error_code = error_code;
508 tsk->thread.trap_no = 13;
509 force_sig(SIGSEGV, tsk);
510 return;
511 }
512
513 /* kernel gp */
514 {
515 const struct exception_table_entry *fixup;
516 fixup = search_exception_tables(regs->rip);
517 if (fixup) {
518 regs->rip = fixup->fixup;
519 return;
520 }
521 if (notify_die(DIE_GPF, "general protection fault", regs,
522 error_code, 13, SIGSEGV) == NOTIFY_STOP)
523 return;
524 die("general protection fault", regs, error_code);
525 }
526}
527
528static void mem_parity_error(unsigned char reason, struct pt_regs * regs)
529{
530 printk("Uhhuh. NMI received. Dazed and confused, but trying to continue\n");
531 printk("You probably have a hardware problem with your RAM chips\n");
532
533 /* Clear and disable the memory parity error line. */
534 reason = (reason & 0xf) | 4;
535 outb(reason, 0x61);
536}
537
538static void io_check_error(unsigned char reason, struct pt_regs * regs)
539{
540 printk("NMI: IOCK error (debug interrupt?)\n");
541 show_registers(regs);
542
543 /* Re-enable the IOCK line, wait for a few seconds */
544 reason = (reason & 0xf) | 8;
545 outb(reason, 0x61);
546 mdelay(2000);
547 reason &= ~8;
548 outb(reason, 0x61);
549}
550
551static void unknown_nmi_error(unsigned char reason, struct pt_regs * regs)
552{ printk("Uhhuh. NMI received for unknown reason %02x.\n", reason);
553 printk("Dazed and confused, but trying to continue\n");
554 printk("Do you have a strange power saving mode enabled?\n");
555}
556
6fefb0d1
AK		 557/* Runs on IST stack. This code must keep interrupts off all the time.
558 Nested NMIs are prevented by the CPU. */
1da177e4
LT		 559asmlinkage void default_do_nmi(struct pt_regs *regs)
560{
561 unsigned char reason = 0;
76e4f660
AR		 562 int cpu;
563
564 cpu = smp_processor_id();
1da177e4
LT		 565
566 /* Only the BSP gets external NMIs from the system. */
76e4f660 567 if (!cpu)
1da177e4
LT		 568 reason = get_nmi_reason();
569
570 if (!(reason & 0xc0)) {
571 if (notify_die(DIE_NMI_IPI, "nmi_ipi", regs, reason, 0, SIGINT)
572 == NOTIFY_STOP)
573 return;
574#ifdef CONFIG_X86_LOCAL_APIC
575 /*
576 * Ok, so this is none of the documented NMI sources,
577 * so it must be the NMI watchdog.
578 */
579 if (nmi_watchdog > 0) {
580 nmi_watchdog_tick(regs,reason);
581 return;
582 }
583#endif
584 unknown_nmi_error(reason, regs);
585 return;
586 }
587 if (notify_die(DIE_NMI, "nmi", regs, reason, 0, SIGINT) == NOTIFY_STOP)
588 return;
589
590 /* AK: following checks seem to be broken on modern chipsets. FIXME */
591
592 if (reason & 0x80)
593 mem_parity_error(reason, regs);
594 if (reason & 0x40)
595 io_check_error(reason, regs);
596}
597
0f2fbdcb 598asmlinkage void __kprobes do_int3(struct pt_regs * regs, long error_code)
1da177e4
LT		 599{
600 if (notify_die(DIE_INT3, "int3", regs, error_code, 3, SIGTRAP) == NOTIFY_STOP) {
601 return;
602 }
603 do_trap(3, SIGTRAP, "int3", regs, error_code, NULL);
604 return;
605}
606
6fefb0d1
AK		 607/* Help handler running on IST stack to switch back to user stack
608 for scheduling or signal handling. The actual stack switch is done in
609 entry.S */
610asmlinkage struct pt_regs *sync_regs(struct pt_regs *eregs)
611{
612 struct pt_regs *regs = eregs;
613 /* Did already sync */
614 if (eregs == (struct pt_regs *)eregs->rsp)
615 ;
616 /* Exception from user space */
76381fee 617 else if (user_mode(eregs))
6fefb0d1
AK		 618 regs = ((struct pt_regs *)current->thread.rsp0) - 1;
619 /* Exception from kernel and interrupts are enabled. Move to
620 kernel process stack. */
621 else if (eregs->eflags & X86_EFLAGS_IF)
622 regs = (struct pt_regs *)(eregs->rsp -= sizeof(struct pt_regs));
623 if (eregs != regs)
624 *regs = *eregs;
625 return regs;
626}
627
1da177e4 628/* runs on IST stack. */
0f2fbdcb
PP		 629asmlinkage void __kprobes do_debug(struct pt_regs * regs,
630 unsigned long error_code)
1da177e4 631{
1da177e4
LT		 632 unsigned long condition;
633 struct task_struct *tsk = current;
634 siginfo_t info;
635
e9129e56 636 get_debugreg(condition, 6);
1da177e4
LT		 637
638 if (notify_die(DIE_DEBUG, "debug", regs, condition, error_code,
daeeafec 639 SIGTRAP) == NOTIFY_STOP)
6fefb0d1 640 return;
daeeafec 641
1da177e4
LT		 642 conditional_sti(regs);
643
644 /* Mask out spurious debug traps due to lazy DR7 setting */
645 if (condition & (DR_TRAP0|DR_TRAP1|DR_TRAP2|DR_TRAP3)) {
646 if (!tsk->thread.debugreg7) {
647 goto clear_dr7;
648 }
649 }
650
651 tsk->thread.debugreg6 = condition;
652
653 /* Mask out spurious TF errors due to lazy TF clearing */
daeeafec 654 if (condition & DR_STEP) {
1da177e4
LT		 655 /*
656 * The TF error should be masked out only if the current
657 * process is not traced and if the TRAP flag has been set
658 * previously by a tracing process (condition detected by
659 * the PT_DTRACE flag); remember that the i386 TRAP flag
660 * can be modified by the process itself in user mode,
661 * allowing programs to debug themselves without the ptrace()
662 * interface.
663 */
76381fee 664 if (!user_mode(regs))
1da177e4 665 goto clear_TF_reenable;
be61bff7
AK		 666 /*
667 * Was the TF flag set by a debugger? If so, clear it now,
668 * so that register information is correct.
669 */
670 if (tsk->ptrace & PT_DTRACE) {
671 regs->eflags &= ~TF_MASK;
672 tsk->ptrace &= ~PT_DTRACE;
673 }
1da177e4
LT		 674 }
675
676 /* Ok, finally something we can handle */
677 tsk->thread.trap_no = 1;
678 tsk->thread.error_code = error_code;
679 info.si_signo = SIGTRAP;
680 info.si_errno = 0;
681 info.si_code = TRAP_BRKPT;
76381fee 682 if (!user_mode(regs))
1da177e4
LT		 683 goto clear_dr7;
684
685 info.si_addr = (void __user *)regs->rip;
686 force_sig_info(SIGTRAP, &info, tsk);
687clear_dr7:
e9129e56 688 set_debugreg(0UL, 7);
6fefb0d1 689 return;
1da177e4
LT		 690
691clear_TF_reenable:
692 set_tsk_thread_flag(tsk, TIF_SINGLESTEP);
1da177e4 693 regs->eflags &= ~TF_MASK;
1da177e4
LT		 694}
695
696static int kernel_math_error(struct pt_regs *regs, char *str)
697{
698 const struct exception_table_entry *fixup;
699 fixup = search_exception_tables(regs->rip);
700 if (fixup) {
701 regs->rip = fixup->fixup;
702 return 1;
703 }
704 notify_die(DIE_GPF, str, regs, 0, 16, SIGFPE);
3a848f63 705 /* Illegal floating point operation in the kernel */
1da177e4 706 die(str, regs, 0);
1da177e4
LT		 707 return 0;
708}
709
710/*
711 * Note that we play around with the 'TS' bit in an attempt to get
712 * the correct behaviour even in the presence of the asynchronous
713 * IRQ13 behaviour
714 */
715asmlinkage void do_coprocessor_error(struct pt_regs *regs)
716{
717 void __user *rip = (void __user *)(regs->rip);
718 struct task_struct * task;
719 siginfo_t info;
720 unsigned short cwd, swd;
721
722 conditional_sti(regs);
76381fee 723 if (!user_mode(regs) &&
1da177e4
LT		 724 kernel_math_error(regs, "kernel x87 math error"))
725 return;
726
727 /*
728 * Save the info for the exception handler and clear the error.
729 */
730 task = current;
731 save_init_fpu(task);
732 task->thread.trap_no = 16;
733 task->thread.error_code = 0;
734 info.si_signo = SIGFPE;
735 info.si_errno = 0;
736 info.si_code = __SI_FAULT;
737 info.si_addr = rip;
738 /*
739 * (~cwd & swd) will mask out exceptions that are not set to unmasked
740 * status. 0x3f is the exception bits in these regs, 0x200 is the
741 * C1 reg you need in case of a stack fault, 0x040 is the stack
742 * fault bit. We should only be taking one exception at a time,
743 * so if this combination doesn't produce any single exception,
744 * then we have a bad program that isn't synchronizing its FPU usage
745 * and it will suffer the consequences since we won't be able to
746 * fully reproduce the context of the exception
747 */
748 cwd = get_fpu_cwd(task);
749 swd = get_fpu_swd(task);
ff347b22 750 switch (swd & ~cwd & 0x3f) {
1da177e4
LT		 751 case 0x000:
752 default:
753 break;
754 case 0x001: /* Invalid Op */
ff347b22
CE		 755 /*
756 * swd & 0x240 == 0x040: Stack Underflow
757 * swd & 0x240 == 0x240: Stack Overflow
758 * User must clear the SF bit (0x40) if set
759 */
1da177e4
LT		 760 info.si_code = FPE_FLTINV;
761 break;
762 case 0x002: /* Denormalize */
763 case 0x010: /* Underflow */
764 info.si_code = FPE_FLTUND;
765 break;
766 case 0x004: /* Zero Divide */
767 info.si_code = FPE_FLTDIV;
768 break;
769 case 0x008: /* Overflow */
770 info.si_code = FPE_FLTOVF;
771 break;
772 case 0x020: /* Precision */
773 info.si_code = FPE_FLTRES;
774 break;
775 }
776 force_sig_info(SIGFPE, &info, task);
777}
778
779asmlinkage void bad_intr(void)
780{
781 printk("bad interrupt");
782}
783
784asmlinkage void do_simd_coprocessor_error(struct pt_regs *regs)
785{
786 void __user *rip = (void __user *)(regs->rip);
787 struct task_struct * task;
788 siginfo_t info;
789 unsigned short mxcsr;
790
791 conditional_sti(regs);
76381fee 792 if (!user_mode(regs) &&
3a848f63 793 kernel_math_error(regs, "kernel simd math error"))
1da177e4
LT		 794 return;
795
796 /*
797 * Save the info for the exception handler and clear the error.
798 */
799 task = current;
800 save_init_fpu(task);
801 task->thread.trap_no = 19;
802 task->thread.error_code = 0;
803 info.si_signo = SIGFPE;
804 info.si_errno = 0;
805 info.si_code = __SI_FAULT;
806 info.si_addr = rip;
807 /*
808 * The SIMD FPU exceptions are handled a little differently, as there
809 * is only a single status/control register. Thus, to determine which
810 * unmasked exception was caught we must mask the exception mask bits
811 * at 0x1f80, and then use these to mask the exception bits at 0x3f.
812 */
813 mxcsr = get_fpu_mxcsr(task);
814 switch (~((mxcsr & 0x1f80) >> 7) & (mxcsr & 0x3f)) {
815 case 0x000:
816 default:
817 break;
818 case 0x001: /* Invalid Op */
819 info.si_code = FPE_FLTINV;
820 break;
821 case 0x002: /* Denormalize */
822 case 0x010: /* Underflow */
823 info.si_code = FPE_FLTUND;
824 break;
825 case 0x004: /* Zero Divide */
826 info.si_code = FPE_FLTDIV;
827 break;
828 case 0x008: /* Overflow */
829 info.si_code = FPE_FLTOVF;
830 break;
831 case 0x020: /* Precision */
832 info.si_code = FPE_FLTRES;
833 break;
834 }
835 force_sig_info(SIGFPE, &info, task);
836}
837
838asmlinkage void do_spurious_interrupt_bug(struct pt_regs * regs)
839{
840}
841
842asmlinkage void __attribute__((weak)) smp_thermal_interrupt(void)
89b831ef
JS		 843{
844}
845
846asmlinkage void __attribute__((weak)) mce_threshold_interrupt(void)
1da177e4
LT		 847{
848}
849
850/*
851 * 'math_state_restore()' saves the current math information in the
852 * old math state array, and gets the new ones from the current task
853 *
854 * Careful.. There are problems with IBM-designed IRQ13 behaviour.
855 * Don't touch unless you *really* know how it works.
856 */
857asmlinkage void math_state_restore(void)
858{
859 struct task_struct *me = current;
860 clts(); /* Allow maths ops (or we recurse) */
861
862 if (!used_math())
863 init_fpu(me);
864 restore_fpu_checking(&me->thread.i387.fxsave);
865 me->thread_info->status |= TS_USEDFPU;
866}
867
868void do_call_debug(struct pt_regs *regs)
869{
870 notify_die(DIE_CALL, "debug call", regs, 0, 255, SIGINT);
871}
872
873void __init trap_init(void)
874{
875 set_intr_gate(0,&divide_error);
876 set_intr_gate_ist(1,&debug,DEBUG_STACK);
877 set_intr_gate_ist(2,&nmi,NMI_STACK);
878 set_system_gate(3,&int3);
0a521588
JB		 879 set_system_gate(4,&overflow); /* int4 can be called from all */
880 set_intr_gate(5,&bounds);
1da177e4
LT		 881 set_intr_gate(6,&invalid_op);
882 set_intr_gate(7,&device_not_available);
883 set_intr_gate_ist(8,&double_fault, DOUBLEFAULT_STACK);
884 set_intr_gate(9,&coprocessor_segment_overrun);
885 set_intr_gate(10,&invalid_TSS);
886 set_intr_gate(11,&segment_not_present);
887 set_intr_gate_ist(12,&stack_segment,STACKFAULT_STACK);
888 set_intr_gate(13,&general_protection);
889 set_intr_gate(14,&page_fault);
890 set_intr_gate(15,&spurious_interrupt_bug);
891 set_intr_gate(16,&coprocessor_error);
892 set_intr_gate(17,&alignment_check);
893#ifdef CONFIG_X86_MCE
894 set_intr_gate_ist(18,&machine_check, MCE_STACK);
895#endif
896 set_intr_gate(19,&simd_coprocessor_error);
897
898#ifdef CONFIG_IA32_EMULATION
899 set_system_gate(IA32_SYSCALL_VECTOR, ia32_syscall);
900#endif
901
902 set_intr_gate(KDB_VECTOR, call_debug);
903
904 /*
905 * Should be a barrier for any external CPU state.
906 */
907 cpu_init();
908}
909
910
911/* Actual parsing is done early in setup.c. */
912static int __init oops_dummy(char *s)
913{
914 panic_on_oops = 1;
915 return -1;
916}
917__setup("oops=", oops_dummy);
918
919static int __init kstack_setup(char *s)
920{
921 kstack_depth_to_print = simple_strtoul(s,NULL,0);
922 return 0;
923}
924__setup("kstack=", kstack_setup);
925
Linux kernel - Deliverables
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