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[PATCH] x86-64: Merge msr.c with i386 version
[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
50#include <linux/irq.h>
51
52
53extern struct gate_struct idt_table[256];
54
55asmlinkage void divide_error(void);
56asmlinkage void debug(void);
57asmlinkage void nmi(void);
58asmlinkage void int3(void);
59asmlinkage void overflow(void);
60asmlinkage void bounds(void);
61asmlinkage void invalid_op(void);
62asmlinkage void device_not_available(void);
63asmlinkage void double_fault(void);
64asmlinkage void coprocessor_segment_overrun(void);
65asmlinkage void invalid_TSS(void);
66asmlinkage void segment_not_present(void);
67asmlinkage void stack_segment(void);
68asmlinkage void general_protection(void);
69asmlinkage void page_fault(void);
70asmlinkage void coprocessor_error(void);
71asmlinkage void simd_coprocessor_error(void);
72asmlinkage void reserved(void);
73asmlinkage void alignment_check(void);
74asmlinkage void machine_check(void);
75asmlinkage void spurious_interrupt_bug(void);
76asmlinkage void call_debug(void);
77
78struct notifier_block *die_chain;
79static DEFINE_SPINLOCK(die_notifier_lock);
80
81int register_die_notifier(struct notifier_block *nb)
82{
83 int err = 0;
84 unsigned long flags;
85 spin_lock_irqsave(&die_notifier_lock, flags);
86 err = notifier_chain_register(&die_chain, nb);
87 spin_unlock_irqrestore(&die_notifier_lock, flags);
88 return err;
89}
90
91static inline void conditional_sti(struct pt_regs *regs)
92{
93 if (regs->eflags & X86_EFLAGS_IF)
94 local_irq_enable();
95}
96
97static int kstack_depth_to_print = 10;
98
99#ifdef CONFIG_KALLSYMS
100#include <linux/kallsyms.h>
101int printk_address(unsigned long address)
102{
103 unsigned long offset = 0, symsize;
104 const char *symname;
105 char *modname;
106 char *delim = ":";
107 char namebuf[128];
108
109 symname = kallsyms_lookup(address, &symsize, &offset, &modname, namebuf);
110 if (!symname)
111 return printk("[<%016lx>]", address);
112 if (!modname)
113 modname = delim = "";
114 return printk("<%016lx>{%s%s%s%s%+ld}",
115 address,delim,modname,delim,symname,offset);
116}
117#else
118int printk_address(unsigned long address)
119{
120 return printk("[<%016lx>]", address);
121}
122#endif
123
0a658002
AK		 124static unsigned long *in_exception_stack(unsigned cpu, unsigned long stack,
125 unsigned *usedp, const char **idp)
126{
127 static const char ids[N_EXCEPTION_STACKS][8] = {
128 [DEBUG_STACK - 1] = "#DB",
129 [NMI_STACK - 1] = "NMI",
130 [DOUBLEFAULT_STACK - 1] = "#DF",
131 [STACKFAULT_STACK - 1] = "#SS",
132 [MCE_STACK - 1] = "#MC",
133 };
134 unsigned k;
1da177e4 135
0a658002
AK		 136 for (k = 0; k < N_EXCEPTION_STACKS; k++) {
137 unsigned long end;
138
139 end = per_cpu(init_tss, cpu).ist[k];
140 if (stack >= end)
141 continue;
142 if (stack >= end - EXCEPTION_STKSZ) {
143 if (*usedp & (1U << k))
144 break;
145 *usedp |= 1U << k;
146 *idp = ids[k];
147 return (unsigned long *)end;
148 }
1da177e4
LT		 149 }
150 return NULL;
0a658002 151}
1da177e4
LT		 152
153/*
154 * x86-64 can have upto three kernel stacks:
155 * process stack
156 * interrupt stack
0a658002 157 * severe exception (double fault, nmi, stack fault, debug, mce) hardware stack
1da177e4
LT		 158 */
159
160void show_trace(unsigned long *stack)
161{
162 unsigned long addr;
0a658002
AK		 163 const unsigned cpu = safe_smp_processor_id();
164 unsigned long *irqstack_end = (unsigned long *)cpu_pda[cpu].irqstackptr;
1da177e4 165 int i;
0a658002 166 unsigned used = 0;
1da177e4
LT		 167
168 printk("\nCall Trace:");
0a658002
AK		 169
170#define HANDLE_STACK(cond) \
171 do while (cond) { \
172 addr = *stack++; \
173 if (kernel_text_address(addr)) { \
174 /* \
175 * If the address is either in the text segment of the \
176 * kernel, or in the region which contains vmalloc'ed \
177 * memory, it *may* be the address of a calling \
178 * routine; if so, print it so that someone tracing \
179 * down the cause of the crash will be able to figure \
180 * out the call path that was taken. \
181 */ \
182 i += printk_address(addr); \
183 if (i > 50) { \
184 printk("\n "); \
185 i = 0; \
186 } \
187 else \
188 i += printk(" "); \
189 } \
190 } while (0)
191
192 for(i = 0; ; ) {
193 const char *id;
194 unsigned long *estack_end;
195 estack_end = in_exception_stack(cpu, (unsigned long)stack,
196 &used, &id);
197
198 if (estack_end) {
199 i += printk(" <%s> ", id);
200 HANDLE_STACK (stack < estack_end);
201 i += printk(" <EOE> ");
202 stack = (unsigned long *) estack_end[-2];
203 continue;
1da177e4 204 }
0a658002
AK		 205 if (irqstack_end) {
206 unsigned long *irqstack;
207 irqstack = irqstack_end -
208 (IRQSTACKSIZE - 64) / sizeof(*irqstack);
209
210 if (stack >= irqstack && stack < irqstack_end) {
211 i += printk(" <IRQ> ");
212 HANDLE_STACK (stack < irqstack_end);
213 stack = (unsigned long *) (irqstack_end[-1]);
214 irqstack_end = NULL;
215 i += printk(" <EOI> ");
216 continue;
1da177e4 217 }
1da177e4 218 }
0a658002 219 break;
1da177e4 220 }
0a658002
AK		 221
222 HANDLE_STACK (((long) stack & (THREAD_SIZE-1)) != 0);
223#undef HANDLE_STACK
1da177e4
LT		 224 printk("\n");
225}
226
227void show_stack(struct task_struct *tsk, unsigned long * rsp)
228{
229 unsigned long *stack;
230 int i;
231 const int cpu = safe_smp_processor_id();
232 unsigned long *irqstack_end = (unsigned long *) (cpu_pda[cpu].irqstackptr);
233 unsigned long *irqstack = (unsigned long *) (cpu_pda[cpu].irqstackptr - IRQSTACKSIZE);
234
235 // debugging aid: "show_stack(NULL, NULL);" prints the
236 // back trace for this cpu.
237
238 if (rsp == NULL) {
239 if (tsk)
240 rsp = (unsigned long *)tsk->thread.rsp;
241 else
242 rsp = (unsigned long *)&rsp;
243 }
244
245 stack = rsp;
246 for(i=0; i < kstack_depth_to_print; i++) {
247 if (stack >= irqstack && stack <= irqstack_end) {
248 if (stack == irqstack_end) {
249 stack = (unsigned long *) (irqstack_end[-1]);
250 printk(" <EOI> ");
251 }
252 } else {
253 if (((long) stack & (THREAD_SIZE-1)) == 0)
254 break;
255 }
256 if (i && ((i % 4) == 0))
257 printk("\n ");
258 printk("%016lx ", *stack++);
35faa714 259 touch_nmi_watchdog();
1da177e4
LT		 260 }
261 show_trace((unsigned long *)rsp);
262}
263
264/*
265 * The architecture-independent dump_stack generator
266 */
267void dump_stack(void)
268{
269 unsigned long dummy;
270 show_trace(&dummy);
271}
272
273EXPORT_SYMBOL(dump_stack);
274
275void show_registers(struct pt_regs *regs)
276{
277 int i;
76381fee 278 int in_kernel = !user_mode(regs);
1da177e4
LT		 279 unsigned long rsp;
280 const int cpu = safe_smp_processor_id();
281 struct task_struct *cur = cpu_pda[cpu].pcurrent;
282
283 rsp = regs->rsp;
284
285 printk("CPU %d ", cpu);
286 __show_regs(regs);
287 printk("Process %s (pid: %d, threadinfo %p, task %p)\n",
288 cur->comm, cur->pid, cur->thread_info, cur);
289
290 /*
291 * When in-kernel, we also print out the stack and code at the
292 * time of the fault..
293 */
294 if (in_kernel) {
295
296 printk("Stack: ");
297 show_stack(NULL, (unsigned long*)rsp);
298
299 printk("\nCode: ");
300 if(regs->rip < PAGE_OFFSET)
301 goto bad;
302
303 for(i=0;i<20;i++)
304 {
305 unsigned char c;
306 if(__get_user(c, &((unsigned char*)regs->rip)[i])) {
307bad:
308 printk(" Bad RIP value.");
309 break;
310 }
311 printk("%02x ", c);
312 }
313 }
314 printk("\n");
315}
316
317void handle_BUG(struct pt_regs *regs)
318{
319 struct bug_frame f;
320 char tmp;
321
76381fee 322 if (user_mode(regs))
1da177e4
LT		 323 return;
324 if (__copy_from_user(&f, (struct bug_frame *) regs->rip,
325 sizeof(struct bug_frame)))
326 return;
327 if ((unsigned long)f.filename < __PAGE_OFFSET ||
328 f.ud2[0] != 0x0f || f.ud2[1] != 0x0b)
329 return;
330 if (__get_user(tmp, f.filename))
331 f.filename = "unmapped filename";
332 printk("----------- [cut here ] --------- [please bite here ] ---------\n");
333 printk(KERN_ALERT "Kernel BUG at %.50s:%d\n", f.filename, f.line);
334}
335
4f60fdf6 336#ifdef CONFIG_BUG
1da177e4
LT		 337void out_of_line_bug(void)
338{
339 BUG();
340}
4f60fdf6 341#endif
1da177e4
LT		 342
343static DEFINE_SPINLOCK(die_lock);
344static int die_owner = -1;
345
346void oops_begin(void)
347{
348 int cpu = safe_smp_processor_id();
349 /* racy, but better than risking deadlock. */
350 local_irq_disable();
351 if (!spin_trylock(&die_lock)) {
352 if (cpu == die_owner)
353 /* nested oops. should stop eventually */;
354 else
355 spin_lock(&die_lock);
356 }
357 die_owner = cpu;
358 console_verbose();
359 bust_spinlocks(1);
360}
361
362void oops_end(void)
363{
364 die_owner = -1;
365 bust_spinlocks(0);
366 spin_unlock(&die_lock);
367 if (panic_on_oops)
368 panic("Oops");
369}
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{
395 oops_begin();
396 handle_BUG(regs);
397 __die(str, regs, err);
398 oops_end();
399 do_exit(SIGSEGV);
400}
401static inline void die_if_kernel(const char * str, struct pt_regs * regs, long err)
402{
403 if (!(regs->eflags & VM_MASK) && (regs->cs == __KERNEL_CS))
404 die(str, regs, err);
405}
406
407void die_nmi(char *str, struct pt_regs *regs)
408{
409 oops_begin();
410 /*
411 * We are in trouble anyway, lets at least try
412 * to get a message out.
413 */
414 printk(str, safe_smp_processor_id());
415 show_registers(regs);
416 if (panic_on_timeout || panic_on_oops)
417 panic("nmi watchdog");
418 printk("console shuts up ...\n");
419 oops_end();
420 do_exit(SIGSEGV);
421}
422
0f2fbdcb
PP		 423static void __kprobes do_trap(int trapnr, int signr, char *str,
424 struct pt_regs * regs, long error_code,
425 siginfo_t *info)
1da177e4
LT		 426{
427 conditional_sti(regs);
428
429#ifdef CONFIG_CHECKING
430 {
431 unsigned long gs;
432 struct x8664_pda *pda = cpu_pda + safe_smp_processor_id();
433 rdmsrl(MSR_GS_BASE, gs);
434 if (gs != (unsigned long)pda) {
435 wrmsrl(MSR_GS_BASE, pda);
436 printk("%s: wrong gs %lx expected %p rip %lx\n", str, gs, pda,
437 regs->rip);
438 }
439 }
440#endif
441
76381fee 442 if (user_mode(regs)) {
1da177e4
LT		 443 struct task_struct *tsk = current;
444
445 if (exception_trace && unhandled_signal(tsk, signr))
446 printk(KERN_INFO
447 "%s[%d] trap %s rip:%lx rsp:%lx error:%lx\n",
448 tsk->comm, tsk->pid, str,
449 regs->rip,regs->rsp,error_code);
450
451 tsk->thread.error_code = error_code;
452 tsk->thread.trap_no = trapnr;
453 if (info)
454 force_sig_info(signr, info, tsk);
455 else
456 force_sig(signr, tsk);
457 return;
458 }
459
460
461 /* kernel trap */
462 {
463 const struct exception_table_entry *fixup;
464 fixup = search_exception_tables(regs->rip);
465 if (fixup) {
466 regs->rip = fixup->fixup;
467 } else
468 die(str, regs, error_code);
469 return;
470 }
471}
472
473#define DO_ERROR(trapnr, signr, str, name) \
474asmlinkage void do_##name(struct pt_regs * regs, long error_code) \
475{ \
476 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
477 == NOTIFY_STOP) \
478 return; \
479 do_trap(trapnr, signr, str, regs, error_code, NULL); \
480}
481
482#define DO_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr) \
483asmlinkage void do_##name(struct pt_regs * regs, long error_code) \
484{ \
485 siginfo_t info; \
486 info.si_signo = signr; \
487 info.si_errno = 0; \
488 info.si_code = sicode; \
489 info.si_addr = (void __user *)siaddr; \
490 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
491 == NOTIFY_STOP) \
492 return; \
493 do_trap(trapnr, signr, str, regs, error_code, &info); \
494}
495
496DO_ERROR_INFO( 0, SIGFPE, "divide error", divide_error, FPE_INTDIV, regs->rip)
497DO_ERROR( 4, SIGSEGV, "overflow", overflow)
498DO_ERROR( 5, SIGSEGV, "bounds", bounds)
499DO_ERROR_INFO( 6, SIGILL, "invalid operand", invalid_op, ILL_ILLOPN, regs->rip)
500DO_ERROR( 7, SIGSEGV, "device not available", device_not_available)
501DO_ERROR( 9, SIGFPE, "coprocessor segment overrun", coprocessor_segment_overrun)
502DO_ERROR(10, SIGSEGV, "invalid TSS", invalid_TSS)
503DO_ERROR(11, SIGBUS, "segment not present", segment_not_present)
504DO_ERROR_INFO(17, SIGBUS, "alignment check", alignment_check, BUS_ADRALN, 0)
505DO_ERROR(18, SIGSEGV, "reserved", reserved)
6fefb0d1
AK		 506DO_ERROR(12, SIGBUS, "stack segment", stack_segment)
507DO_ERROR( 8, SIGSEGV, "double fault", double_fault)
1da177e4 508
0f2fbdcb
PP		 509asmlinkage void __kprobes do_general_protection(struct pt_regs * regs,
510 long error_code)
1da177e4
LT		 511{
512 conditional_sti(regs);
513
514#ifdef CONFIG_CHECKING
515 {
516 unsigned long gs;
517 struct x8664_pda *pda = cpu_pda + safe_smp_processor_id();
518 rdmsrl(MSR_GS_BASE, gs);
519 if (gs != (unsigned long)pda) {
520 wrmsrl(MSR_GS_BASE, pda);
521 oops_in_progress++;
522 printk("general protection handler: wrong gs %lx expected %p\n", gs, pda);
523 oops_in_progress--;
524 }
525 }
526#endif
527
76381fee 528 if (user_mode(regs)) {
1da177e4
LT		 529 struct task_struct *tsk = current;
530
531 if (exception_trace && unhandled_signal(tsk, SIGSEGV))
532 printk(KERN_INFO
533 "%s[%d] general protection rip:%lx rsp:%lx error:%lx\n",
534 tsk->comm, tsk->pid,
535 regs->rip,regs->rsp,error_code);
536
537 tsk->thread.error_code = error_code;
538 tsk->thread.trap_no = 13;
539 force_sig(SIGSEGV, tsk);
540 return;
541 }
542
543 /* kernel gp */
544 {
545 const struct exception_table_entry *fixup;
546 fixup = search_exception_tables(regs->rip);
547 if (fixup) {
548 regs->rip = fixup->fixup;
549 return;
550 }
551 if (notify_die(DIE_GPF, "general protection fault", regs,
552 error_code, 13, SIGSEGV) == NOTIFY_STOP)
553 return;
554 die("general protection fault", regs, error_code);
555 }
556}
557
558static void mem_parity_error(unsigned char reason, struct pt_regs * regs)
559{
560 printk("Uhhuh. NMI received. Dazed and confused, but trying to continue\n");
561 printk("You probably have a hardware problem with your RAM chips\n");
562
563 /* Clear and disable the memory parity error line. */
564 reason = (reason & 0xf) | 4;
565 outb(reason, 0x61);
566}
567
568static void io_check_error(unsigned char reason, struct pt_regs * regs)
569{
570 printk("NMI: IOCK error (debug interrupt?)\n");
571 show_registers(regs);
572
573 /* Re-enable the IOCK line, wait for a few seconds */
574 reason = (reason & 0xf) | 8;
575 outb(reason, 0x61);
576 mdelay(2000);
577 reason &= ~8;
578 outb(reason, 0x61);
579}
580
581static void unknown_nmi_error(unsigned char reason, struct pt_regs * regs)
582{ printk("Uhhuh. NMI received for unknown reason %02x.\n", reason);
583 printk("Dazed and confused, but trying to continue\n");
584 printk("Do you have a strange power saving mode enabled?\n");
585}
586
6fefb0d1
AK		 587/* Runs on IST stack. This code must keep interrupts off all the time.
588 Nested NMIs are prevented by the CPU. */
1da177e4
LT		 589asmlinkage void default_do_nmi(struct pt_regs *regs)
590{
591 unsigned char reason = 0;
76e4f660
AR		 592 int cpu;
593
594 cpu = smp_processor_id();
1da177e4
LT		 595
596 /* Only the BSP gets external NMIs from the system. */
76e4f660 597 if (!cpu)
1da177e4
LT		 598 reason = get_nmi_reason();
599
600 if (!(reason & 0xc0)) {
601 if (notify_die(DIE_NMI_IPI, "nmi_ipi", regs, reason, 0, SIGINT)
602 == NOTIFY_STOP)
603 return;
604#ifdef CONFIG_X86_LOCAL_APIC
605 /*
606 * Ok, so this is none of the documented NMI sources,
607 * so it must be the NMI watchdog.
608 */
609 if (nmi_watchdog > 0) {
610 nmi_watchdog_tick(regs,reason);
611 return;
612 }
613#endif
614 unknown_nmi_error(reason, regs);
615 return;
616 }
617 if (notify_die(DIE_NMI, "nmi", regs, reason, 0, SIGINT) == NOTIFY_STOP)
618 return;
619
620 /* AK: following checks seem to be broken on modern chipsets. FIXME */
621
622 if (reason & 0x80)
623 mem_parity_error(reason, regs);
624 if (reason & 0x40)
625 io_check_error(reason, regs);
626}
627
0f2fbdcb 628asmlinkage void __kprobes do_int3(struct pt_regs * regs, long error_code)
1da177e4
LT		 629{
630 if (notify_die(DIE_INT3, "int3", regs, error_code, 3, SIGTRAP) == NOTIFY_STOP) {
631 return;
632 }
633 do_trap(3, SIGTRAP, "int3", regs, error_code, NULL);
634 return;
635}
636
6fefb0d1
AK		 637/* Help handler running on IST stack to switch back to user stack
638 for scheduling or signal handling. The actual stack switch is done in
639 entry.S */
640asmlinkage struct pt_regs *sync_regs(struct pt_regs *eregs)
641{
642 struct pt_regs *regs = eregs;
643 /* Did already sync */
644 if (eregs == (struct pt_regs *)eregs->rsp)
645 ;
646 /* Exception from user space */
76381fee 647 else if (user_mode(eregs))
6fefb0d1
AK		 648 regs = ((struct pt_regs *)current->thread.rsp0) - 1;
649 /* Exception from kernel and interrupts are enabled. Move to
650 kernel process stack. */
651 else if (eregs->eflags & X86_EFLAGS_IF)
652 regs = (struct pt_regs *)(eregs->rsp -= sizeof(struct pt_regs));
653 if (eregs != regs)
654 *regs = *eregs;
655 return regs;
656}
657
1da177e4 658/* runs on IST stack. */
0f2fbdcb
PP		 659asmlinkage void __kprobes do_debug(struct pt_regs * regs,
660 unsigned long error_code)
1da177e4 661{
1da177e4
LT		 662 unsigned long condition;
663 struct task_struct *tsk = current;
664 siginfo_t info;
665
1da177e4
LT		 666#ifdef CONFIG_CHECKING
667 {
668 /* RED-PEN interaction with debugger - could destroy gs */
669 unsigned long gs;
670 struct x8664_pda *pda = cpu_pda + safe_smp_processor_id();
671 rdmsrl(MSR_GS_BASE, gs);
672 if (gs != (unsigned long)pda) {
673 wrmsrl(MSR_GS_BASE, pda);
674 printk("debug handler: wrong gs %lx expected %p\n", gs, pda);
675 }
676 }
677#endif
678
e9129e56 679 get_debugreg(condition, 6);
1da177e4
LT		 680
681 if (notify_die(DIE_DEBUG, "debug", regs, condition, error_code,
daeeafec 682 SIGTRAP) == NOTIFY_STOP)
6fefb0d1 683 return;
daeeafec 684
1da177e4
LT		 685 conditional_sti(regs);
686
687 /* Mask out spurious debug traps due to lazy DR7 setting */
688 if (condition & (DR_TRAP0|DR_TRAP1|DR_TRAP2|DR_TRAP3)) {
689 if (!tsk->thread.debugreg7) {
690 goto clear_dr7;
691 }
692 }
693
694 tsk->thread.debugreg6 = condition;
695
696 /* Mask out spurious TF errors due to lazy TF clearing */
daeeafec 697 if (condition & DR_STEP) {
1da177e4
LT		 698 /*
699 * The TF error should be masked out only if the current
700 * process is not traced and if the TRAP flag has been set
701 * previously by a tracing process (condition detected by
702 * the PT_DTRACE flag); remember that the i386 TRAP flag
703 * can be modified by the process itself in user mode,
704 * allowing programs to debug themselves without the ptrace()
705 * interface.
706 */
76381fee 707 if (!user_mode(regs))
1da177e4 708 goto clear_TF_reenable;
be61bff7
AK		 709 /*
710 * Was the TF flag set by a debugger? If so, clear it now,
711 * so that register information is correct.
712 */
713 if (tsk->ptrace & PT_DTRACE) {
714 regs->eflags &= ~TF_MASK;
715 tsk->ptrace &= ~PT_DTRACE;
716 }
1da177e4
LT		 717 }
718
719 /* Ok, finally something we can handle */
720 tsk->thread.trap_no = 1;
721 tsk->thread.error_code = error_code;
722 info.si_signo = SIGTRAP;
723 info.si_errno = 0;
724 info.si_code = TRAP_BRKPT;
76381fee 725 if (!user_mode(regs))
1da177e4
LT		 726 goto clear_dr7;
727
728 info.si_addr = (void __user *)regs->rip;
729 force_sig_info(SIGTRAP, &info, tsk);
730clear_dr7:
e9129e56 731 set_debugreg(0UL, 7);
6fefb0d1 732 return;
1da177e4
LT		 733
734clear_TF_reenable:
735 set_tsk_thread_flag(tsk, TIF_SINGLESTEP);
1da177e4 736 regs->eflags &= ~TF_MASK;
1da177e4
LT		 737}
738
739static int kernel_math_error(struct pt_regs *regs, char *str)
740{
741 const struct exception_table_entry *fixup;
742 fixup = search_exception_tables(regs->rip);
743 if (fixup) {
744 regs->rip = fixup->fixup;
745 return 1;
746 }
747 notify_die(DIE_GPF, str, regs, 0, 16, SIGFPE);
3a848f63 748 /* Illegal floating point operation in the kernel */
1da177e4 749 die(str, regs, 0);
1da177e4
LT		 750 return 0;
751}
752
753/*
754 * Note that we play around with the 'TS' bit in an attempt to get
755 * the correct behaviour even in the presence of the asynchronous
756 * IRQ13 behaviour
757 */
758asmlinkage void do_coprocessor_error(struct pt_regs *regs)
759{
760 void __user *rip = (void __user *)(regs->rip);
761 struct task_struct * task;
762 siginfo_t info;
763 unsigned short cwd, swd;
764
765 conditional_sti(regs);
76381fee 766 if (!user_mode(regs) &&
1da177e4
LT		 767 kernel_math_error(regs, "kernel x87 math error"))
768 return;
769
770 /*
771 * Save the info for the exception handler and clear the error.
772 */
773 task = current;
774 save_init_fpu(task);
775 task->thread.trap_no = 16;
776 task->thread.error_code = 0;
777 info.si_signo = SIGFPE;
778 info.si_errno = 0;
779 info.si_code = __SI_FAULT;
780 info.si_addr = rip;
781 /*
782 * (~cwd & swd) will mask out exceptions that are not set to unmasked
783 * status. 0x3f is the exception bits in these regs, 0x200 is the
784 * C1 reg you need in case of a stack fault, 0x040 is the stack
785 * fault bit. We should only be taking one exception at a time,
786 * so if this combination doesn't produce any single exception,
787 * then we have a bad program that isn't synchronizing its FPU usage
788 * and it will suffer the consequences since we won't be able to
789 * fully reproduce the context of the exception
790 */
791 cwd = get_fpu_cwd(task);
792 swd = get_fpu_swd(task);
793 switch (((~cwd) & swd & 0x3f) | (swd & 0x240)) {
794 case 0x000:
795 default:
796 break;
797 case 0x001: /* Invalid Op */
798 case 0x041: /* Stack Fault */
799 case 0x241: /* Stack Fault | Direction */
800 info.si_code = FPE_FLTINV;
801 break;
802 case 0x002: /* Denormalize */
803 case 0x010: /* Underflow */
804 info.si_code = FPE_FLTUND;
805 break;
806 case 0x004: /* Zero Divide */
807 info.si_code = FPE_FLTDIV;
808 break;
809 case 0x008: /* Overflow */
810 info.si_code = FPE_FLTOVF;
811 break;
812 case 0x020: /* Precision */
813 info.si_code = FPE_FLTRES;
814 break;
815 }
816 force_sig_info(SIGFPE, &info, task);
817}
818
819asmlinkage void bad_intr(void)
820{
821 printk("bad interrupt");
822}
823
824asmlinkage void do_simd_coprocessor_error(struct pt_regs *regs)
825{
826 void __user *rip = (void __user *)(regs->rip);
827 struct task_struct * task;
828 siginfo_t info;
829 unsigned short mxcsr;
830
831 conditional_sti(regs);
76381fee 832 if (!user_mode(regs) &&
3a848f63 833 kernel_math_error(regs, "kernel simd math error"))
1da177e4
LT		 834 return;
835
836 /*
837 * Save the info for the exception handler and clear the error.
838 */
839 task = current;
840 save_init_fpu(task);
841 task->thread.trap_no = 19;
842 task->thread.error_code = 0;
843 info.si_signo = SIGFPE;
844 info.si_errno = 0;
845 info.si_code = __SI_FAULT;
846 info.si_addr = rip;
847 /*
848 * The SIMD FPU exceptions are handled a little differently, as there
849 * is only a single status/control register. Thus, to determine which
850 * unmasked exception was caught we must mask the exception mask bits
851 * at 0x1f80, and then use these to mask the exception bits at 0x3f.
852 */
853 mxcsr = get_fpu_mxcsr(task);
854 switch (~((mxcsr & 0x1f80) >> 7) & (mxcsr & 0x3f)) {
855 case 0x000:
856 default:
857 break;
858 case 0x001: /* Invalid Op */
859 info.si_code = FPE_FLTINV;
860 break;
861 case 0x002: /* Denormalize */
862 case 0x010: /* Underflow */
863 info.si_code = FPE_FLTUND;
864 break;
865 case 0x004: /* Zero Divide */
866 info.si_code = FPE_FLTDIV;
867 break;
868 case 0x008: /* Overflow */
869 info.si_code = FPE_FLTOVF;
870 break;
871 case 0x020: /* Precision */
872 info.si_code = FPE_FLTRES;
873 break;
874 }
875 force_sig_info(SIGFPE, &info, task);
876}
877
878asmlinkage void do_spurious_interrupt_bug(struct pt_regs * regs)
879{
880}
881
882asmlinkage void __attribute__((weak)) smp_thermal_interrupt(void)
883{
884}
885
886/*
887 * 'math_state_restore()' saves the current math information in the
888 * old math state array, and gets the new ones from the current task
889 *
890 * Careful.. There are problems with IBM-designed IRQ13 behaviour.
891 * Don't touch unless you *really* know how it works.
892 */
893asmlinkage void math_state_restore(void)
894{
895 struct task_struct *me = current;
896 clts(); /* Allow maths ops (or we recurse) */
897
898 if (!used_math())
899 init_fpu(me);
900 restore_fpu_checking(&me->thread.i387.fxsave);
901 me->thread_info->status |= TS_USEDFPU;
902}
903
904void do_call_debug(struct pt_regs *regs)
905{
906 notify_die(DIE_CALL, "debug call", regs, 0, 255, SIGINT);
907}
908
909void __init trap_init(void)
910{
911 set_intr_gate(0,&divide_error);
912 set_intr_gate_ist(1,&debug,DEBUG_STACK);
913 set_intr_gate_ist(2,&nmi,NMI_STACK);
914 set_system_gate(3,&int3);
915 set_system_gate(4,&overflow); /* int4-5 can be called from all */
916 set_system_gate(5,&bounds);
917 set_intr_gate(6,&invalid_op);
918 set_intr_gate(7,&device_not_available);
919 set_intr_gate_ist(8,&double_fault, DOUBLEFAULT_STACK);
920 set_intr_gate(9,&coprocessor_segment_overrun);
921 set_intr_gate(10,&invalid_TSS);
922 set_intr_gate(11,&segment_not_present);
923 set_intr_gate_ist(12,&stack_segment,STACKFAULT_STACK);
924 set_intr_gate(13,&general_protection);
925 set_intr_gate(14,&page_fault);
926 set_intr_gate(15,&spurious_interrupt_bug);
927 set_intr_gate(16,&coprocessor_error);
928 set_intr_gate(17,&alignment_check);
929#ifdef CONFIG_X86_MCE
930 set_intr_gate_ist(18,&machine_check, MCE_STACK);
931#endif
932 set_intr_gate(19,&simd_coprocessor_error);
933
934#ifdef CONFIG_IA32_EMULATION
935 set_system_gate(IA32_SYSCALL_VECTOR, ia32_syscall);
936#endif
937
938 set_intr_gate(KDB_VECTOR, call_debug);
939
940 /*
941 * Should be a barrier for any external CPU state.
942 */
943 cpu_init();
944}
945
946
947/* Actual parsing is done early in setup.c. */
948static int __init oops_dummy(char *s)
949{
950 panic_on_oops = 1;
951 return -1;
952}
953__setup("oops=", oops_dummy);
954
955static int __init kstack_setup(char *s)
956{
957 kstack_depth_to_print = simple_strtoul(s,NULL,0);
958 return 0;
959}
960__setup("kstack=", kstack_setup);
961
Linux kernel - Deliverables
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