]> git.proxmox.com Git - mirror_ubuntu-kernels.git/blame - arch/x86_64/kernel/traps.c
projects / mirror_ubuntu-kernels.git / blame
? search:
summary | shortlog | log | commit | commitdiff | tree
blob | blame (incremental) | history | HEAD
[PATCH] x86_64: make trap information available to die notification handlers
[mirror_ubuntu-kernels.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");
6e3f3617 385 notify_die(DIE_OOPS, str, regs, err, current->thread.trap_no, SIGSEGV);
1da177e4
LT		 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 423{
6e3f3617
JB		 424 struct task_struct *tsk = current;
425
1da177e4
LT		 426 conditional_sti(regs);
427
6e3f3617
JB		 428 tsk->thread.error_code = error_code;
429 tsk->thread.trap_no = trapnr;
1da177e4 430
6e3f3617 431 if (user_mode(regs)) {
1da177e4
LT		 432 if (exception_trace && unhandled_signal(tsk, signr))
433 printk(KERN_INFO
434 "%s[%d] trap %s rip:%lx rsp:%lx error:%lx\n",
435 tsk->comm, tsk->pid, str,
436 regs->rip,regs->rsp,error_code);
437
1da177e4
LT		 438 if (info)
439 force_sig_info(signr, info, tsk);
440 else
441 force_sig(signr, tsk);
442 return;
443 }
444
445
446 /* kernel trap */
447 {
448 const struct exception_table_entry *fixup;
449 fixup = search_exception_tables(regs->rip);
450 if (fixup) {
451 regs->rip = fixup->fixup;
452 } else
453 die(str, regs, error_code);
454 return;
455 }
456}
457
458#define DO_ERROR(trapnr, signr, str, name) \
459asmlinkage void do_##name(struct pt_regs * regs, long error_code) \
460{ \
461 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
462 == NOTIFY_STOP) \
463 return; \
464 do_trap(trapnr, signr, str, regs, error_code, NULL); \
465}
466
467#define DO_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr) \
468asmlinkage void do_##name(struct pt_regs * regs, long error_code) \
469{ \
470 siginfo_t info; \
471 info.si_signo = signr; \
472 info.si_errno = 0; \
473 info.si_code = sicode; \
474 info.si_addr = (void __user *)siaddr; \
475 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
476 == NOTIFY_STOP) \
477 return; \
478 do_trap(trapnr, signr, str, regs, error_code, &info); \
479}
480
481DO_ERROR_INFO( 0, SIGFPE, "divide error", divide_error, FPE_INTDIV, regs->rip)
482DO_ERROR( 4, SIGSEGV, "overflow", overflow)
483DO_ERROR( 5, SIGSEGV, "bounds", bounds)
484DO_ERROR_INFO( 6, SIGILL, "invalid operand", invalid_op, ILL_ILLOPN, regs->rip)
485DO_ERROR( 7, SIGSEGV, "device not available", device_not_available)
486DO_ERROR( 9, SIGFPE, "coprocessor segment overrun", coprocessor_segment_overrun)
487DO_ERROR(10, SIGSEGV, "invalid TSS", invalid_TSS)
488DO_ERROR(11, SIGBUS, "segment not present", segment_not_present)
489DO_ERROR_INFO(17, SIGBUS, "alignment check", alignment_check, BUS_ADRALN, 0)
490DO_ERROR(18, SIGSEGV, "reserved", reserved)
6fefb0d1
AK		 491DO_ERROR(12, SIGBUS, "stack segment", stack_segment)
492DO_ERROR( 8, SIGSEGV, "double fault", double_fault)
1da177e4 493
0f2fbdcb
PP		 494asmlinkage void __kprobes do_general_protection(struct pt_regs * regs,
495 long error_code)
1da177e4 496{
6e3f3617
JB		 497 struct task_struct *tsk = current;
498
1da177e4
LT		 499 conditional_sti(regs);
500
6e3f3617
JB		 501 tsk->thread.error_code = error_code;
502 tsk->thread.trap_no = 13;
1da177e4 503
6e3f3617 504 if (user_mode(regs)) {
1da177e4
LT		 505 if (exception_trace && unhandled_signal(tsk, SIGSEGV))
506 printk(KERN_INFO
507 "%s[%d] general protection rip:%lx rsp:%lx error:%lx\n",
508 tsk->comm, tsk->pid,
509 regs->rip,regs->rsp,error_code);
510
1da177e4
LT		 511 force_sig(SIGSEGV, tsk);
512 return;
513 }
514
515 /* kernel gp */
516 {
517 const struct exception_table_entry *fixup;
518 fixup = search_exception_tables(regs->rip);
519 if (fixup) {
520 regs->rip = fixup->fixup;
521 return;
522 }
523 if (notify_die(DIE_GPF, "general protection fault", regs,
524 error_code, 13, SIGSEGV) == NOTIFY_STOP)
525 return;
526 die("general protection fault", regs, error_code);
527 }
528}
529
530static void mem_parity_error(unsigned char reason, struct pt_regs * regs)
531{
532 printk("Uhhuh. NMI received. Dazed and confused, but trying to continue\n");
533 printk("You probably have a hardware problem with your RAM chips\n");
534
535 /* Clear and disable the memory parity error line. */
536 reason = (reason & 0xf) | 4;
537 outb(reason, 0x61);
538}
539
540static void io_check_error(unsigned char reason, struct pt_regs * regs)
541{
542 printk("NMI: IOCK error (debug interrupt?)\n");
543 show_registers(regs);
544
545 /* Re-enable the IOCK line, wait for a few seconds */
546 reason = (reason & 0xf) | 8;
547 outb(reason, 0x61);
548 mdelay(2000);
549 reason &= ~8;
550 outb(reason, 0x61);
551}
552
553static void unknown_nmi_error(unsigned char reason, struct pt_regs * regs)
554{ printk("Uhhuh. NMI received for unknown reason %02x.\n", reason);
555 printk("Dazed and confused, but trying to continue\n");
556 printk("Do you have a strange power saving mode enabled?\n");
557}
558
6fefb0d1
AK		 559/* Runs on IST stack. This code must keep interrupts off all the time.
560 Nested NMIs are prevented by the CPU. */
1da177e4
LT		 561asmlinkage void default_do_nmi(struct pt_regs *regs)
562{
563 unsigned char reason = 0;
76e4f660
AR		 564 int cpu;
565
566 cpu = smp_processor_id();
1da177e4
LT		 567
568 /* Only the BSP gets external NMIs from the system. */
76e4f660 569 if (!cpu)
1da177e4
LT		 570 reason = get_nmi_reason();
571
572 if (!(reason & 0xc0)) {
6e3f3617 573 if (notify_die(DIE_NMI_IPI, "nmi_ipi", regs, reason, 2, SIGINT)
1da177e4
LT		 574 == NOTIFY_STOP)
575 return;
576#ifdef CONFIG_X86_LOCAL_APIC
577 /*
578 * Ok, so this is none of the documented NMI sources,
579 * so it must be the NMI watchdog.
580 */
581 if (nmi_watchdog > 0) {
582 nmi_watchdog_tick(regs,reason);
583 return;
584 }
585#endif
586 unknown_nmi_error(reason, regs);
587 return;
588 }
6e3f3617 589 if (notify_die(DIE_NMI, "nmi", regs, reason, 2, SIGINT) == NOTIFY_STOP)
1da177e4
LT		 590 return;
591
592 /* AK: following checks seem to be broken on modern chipsets. FIXME */
593
594 if (reason & 0x80)
595 mem_parity_error(reason, regs);
596 if (reason & 0x40)
597 io_check_error(reason, regs);
598}
599
0f2fbdcb 600asmlinkage void __kprobes do_int3(struct pt_regs * regs, long error_code)
1da177e4
LT		 601{
602 if (notify_die(DIE_INT3, "int3", regs, error_code, 3, SIGTRAP) == NOTIFY_STOP) {
603 return;
604 }
605 do_trap(3, SIGTRAP, "int3", regs, error_code, NULL);
606 return;
607}
608
6fefb0d1
AK		 609/* Help handler running on IST stack to switch back to user stack
610 for scheduling or signal handling. The actual stack switch is done in
611 entry.S */
612asmlinkage struct pt_regs *sync_regs(struct pt_regs *eregs)
613{
614 struct pt_regs *regs = eregs;
615 /* Did already sync */
616 if (eregs == (struct pt_regs *)eregs->rsp)
617 ;
618 /* Exception from user space */
76381fee 619 else if (user_mode(eregs))
6fefb0d1
AK		 620 regs = ((struct pt_regs *)current->thread.rsp0) - 1;
621 /* Exception from kernel and interrupts are enabled. Move to
622 kernel process stack. */
623 else if (eregs->eflags & X86_EFLAGS_IF)
624 regs = (struct pt_regs *)(eregs->rsp -= sizeof(struct pt_regs));
625 if (eregs != regs)
626 *regs = *eregs;
627 return regs;
628}
629
1da177e4 630/* runs on IST stack. */
0f2fbdcb
PP		 631asmlinkage void __kprobes do_debug(struct pt_regs * regs,
632 unsigned long error_code)
1da177e4 633{
1da177e4
LT		 634 unsigned long condition;
635 struct task_struct *tsk = current;
636 siginfo_t info;
637
e9129e56 638 get_debugreg(condition, 6);
1da177e4
LT		 639
640 if (notify_die(DIE_DEBUG, "debug", regs, condition, error_code,
daeeafec 641 SIGTRAP) == NOTIFY_STOP)
6fefb0d1 642 return;
daeeafec 643
1da177e4
LT		 644 conditional_sti(regs);
645
646 /* Mask out spurious debug traps due to lazy DR7 setting */
647 if (condition & (DR_TRAP0|DR_TRAP1|DR_TRAP2|DR_TRAP3)) {
648 if (!tsk->thread.debugreg7) {
649 goto clear_dr7;
650 }
651 }
652
653 tsk->thread.debugreg6 = condition;
654
655 /* Mask out spurious TF errors due to lazy TF clearing */
daeeafec 656 if (condition & DR_STEP) {
1da177e4
LT		 657 /*
658 * The TF error should be masked out only if the current
659 * process is not traced and if the TRAP flag has been set
660 * previously by a tracing process (condition detected by
661 * the PT_DTRACE flag); remember that the i386 TRAP flag
662 * can be modified by the process itself in user mode,
663 * allowing programs to debug themselves without the ptrace()
664 * interface.
665 */
76381fee 666 if (!user_mode(regs))
1da177e4 667 goto clear_TF_reenable;
be61bff7
AK		 668 /*
669 * Was the TF flag set by a debugger? If so, clear it now,
670 * so that register information is correct.
671 */
672 if (tsk->ptrace & PT_DTRACE) {
673 regs->eflags &= ~TF_MASK;
674 tsk->ptrace &= ~PT_DTRACE;
675 }
1da177e4
LT		 676 }
677
678 /* Ok, finally something we can handle */
679 tsk->thread.trap_no = 1;
680 tsk->thread.error_code = error_code;
681 info.si_signo = SIGTRAP;
682 info.si_errno = 0;
683 info.si_code = TRAP_BRKPT;
76381fee 684 if (!user_mode(regs))
1da177e4
LT		 685 goto clear_dr7;
686
687 info.si_addr = (void __user *)regs->rip;
688 force_sig_info(SIGTRAP, &info, tsk);
689clear_dr7:
e9129e56 690 set_debugreg(0UL, 7);
6fefb0d1 691 return;
1da177e4
LT		 692
693clear_TF_reenable:
694 set_tsk_thread_flag(tsk, TIF_SINGLESTEP);
1da177e4 695 regs->eflags &= ~TF_MASK;
1da177e4
LT		 696}
697
6e3f3617 698static int kernel_math_error(struct pt_regs *regs, const char *str, int trapnr)
1da177e4
LT		 699{
700 const struct exception_table_entry *fixup;
701 fixup = search_exception_tables(regs->rip);
702 if (fixup) {
703 regs->rip = fixup->fixup;
704 return 1;
705 }
6e3f3617 706 notify_die(DIE_GPF, str, regs, 0, trapnr, SIGFPE);
3a848f63 707 /* Illegal floating point operation in the kernel */
6e3f3617 708 current->thread.trap_no = trapnr;
1da177e4 709 die(str, regs, 0);
1da177e4
LT		 710 return 0;
711}
712
713/*
714 * Note that we play around with the 'TS' bit in an attempt to get
715 * the correct behaviour even in the presence of the asynchronous
716 * IRQ13 behaviour
717 */
718asmlinkage void do_coprocessor_error(struct pt_regs *regs)
719{
720 void __user *rip = (void __user *)(regs->rip);
721 struct task_struct * task;
722 siginfo_t info;
723 unsigned short cwd, swd;
724
725 conditional_sti(regs);
76381fee 726 if (!user_mode(regs) &&
6e3f3617 727 kernel_math_error(regs, "kernel x87 math error", 16))
1da177e4
LT		 728 return;
729
730 /*
731 * Save the info for the exception handler and clear the error.
732 */
733 task = current;
734 save_init_fpu(task);
735 task->thread.trap_no = 16;
736 task->thread.error_code = 0;
737 info.si_signo = SIGFPE;
738 info.si_errno = 0;
739 info.si_code = __SI_FAULT;
740 info.si_addr = rip;
741 /*
742 * (~cwd & swd) will mask out exceptions that are not set to unmasked
743 * status. 0x3f is the exception bits in these regs, 0x200 is the
744 * C1 reg you need in case of a stack fault, 0x040 is the stack
745 * fault bit. We should only be taking one exception at a time,
746 * so if this combination doesn't produce any single exception,
747 * then we have a bad program that isn't synchronizing its FPU usage
748 * and it will suffer the consequences since we won't be able to
749 * fully reproduce the context of the exception
750 */
751 cwd = get_fpu_cwd(task);
752 swd = get_fpu_swd(task);
ff347b22 753 switch (swd & ~cwd & 0x3f) {
1da177e4
LT		 754 case 0x000:
755 default:
756 break;
757 case 0x001: /* Invalid Op */
ff347b22
CE		 758 /*
759 * swd & 0x240 == 0x040: Stack Underflow
760 * swd & 0x240 == 0x240: Stack Overflow
761 * User must clear the SF bit (0x40) if set
762 */
1da177e4
LT		 763 info.si_code = FPE_FLTINV;
764 break;
765 case 0x002: /* Denormalize */
766 case 0x010: /* Underflow */
767 info.si_code = FPE_FLTUND;
768 break;
769 case 0x004: /* Zero Divide */
770 info.si_code = FPE_FLTDIV;
771 break;
772 case 0x008: /* Overflow */
773 info.si_code = FPE_FLTOVF;
774 break;
775 case 0x020: /* Precision */
776 info.si_code = FPE_FLTRES;
777 break;
778 }
779 force_sig_info(SIGFPE, &info, task);
780}
781
782asmlinkage void bad_intr(void)
783{
784 printk("bad interrupt");
785}
786
787asmlinkage void do_simd_coprocessor_error(struct pt_regs *regs)
788{
789 void __user *rip = (void __user *)(regs->rip);
790 struct task_struct * task;
791 siginfo_t info;
792 unsigned short mxcsr;
793
794 conditional_sti(regs);
76381fee 795 if (!user_mode(regs) &&
6e3f3617 796 kernel_math_error(regs, "kernel simd math error", 19))
1da177e4
LT		 797 return;
798
799 /*
800 * Save the info for the exception handler and clear the error.
801 */
802 task = current;
803 save_init_fpu(task);
804 task->thread.trap_no = 19;
805 task->thread.error_code = 0;
806 info.si_signo = SIGFPE;
807 info.si_errno = 0;
808 info.si_code = __SI_FAULT;
809 info.si_addr = rip;
810 /*
811 * The SIMD FPU exceptions are handled a little differently, as there
812 * is only a single status/control register. Thus, to determine which
813 * unmasked exception was caught we must mask the exception mask bits
814 * at 0x1f80, and then use these to mask the exception bits at 0x3f.
815 */
816 mxcsr = get_fpu_mxcsr(task);
817 switch (~((mxcsr & 0x1f80) >> 7) & (mxcsr & 0x3f)) {
818 case 0x000:
819 default:
820 break;
821 case 0x001: /* Invalid Op */
822 info.si_code = FPE_FLTINV;
823 break;
824 case 0x002: /* Denormalize */
825 case 0x010: /* Underflow */
826 info.si_code = FPE_FLTUND;
827 break;
828 case 0x004: /* Zero Divide */
829 info.si_code = FPE_FLTDIV;
830 break;
831 case 0x008: /* Overflow */
832 info.si_code = FPE_FLTOVF;
833 break;
834 case 0x020: /* Precision */
835 info.si_code = FPE_FLTRES;
836 break;
837 }
838 force_sig_info(SIGFPE, &info, task);
839}
840
841asmlinkage void do_spurious_interrupt_bug(struct pt_regs * regs)
842{
843}
844
845asmlinkage void __attribute__((weak)) smp_thermal_interrupt(void)
89b831ef
JS		 846{
847}
848
849asmlinkage void __attribute__((weak)) mce_threshold_interrupt(void)
1da177e4
LT		 850{
851}
852
853/*
854 * 'math_state_restore()' saves the current math information in the
855 * old math state array, and gets the new ones from the current task
856 *
857 * Careful.. There are problems with IBM-designed IRQ13 behaviour.
858 * Don't touch unless you *really* know how it works.
859 */
860asmlinkage void math_state_restore(void)
861{
862 struct task_struct *me = current;
863 clts(); /* Allow maths ops (or we recurse) */
864
865 if (!used_math())
866 init_fpu(me);
867 restore_fpu_checking(&me->thread.i387.fxsave);
868 me->thread_info->status |= TS_USEDFPU;
869}
870
871void do_call_debug(struct pt_regs *regs)
872{
873 notify_die(DIE_CALL, "debug call", regs, 0, 255, SIGINT);
874}
875
876void __init trap_init(void)
877{
878 set_intr_gate(0,&divide_error);
879 set_intr_gate_ist(1,&debug,DEBUG_STACK);
880 set_intr_gate_ist(2,&nmi,NMI_STACK);
881 set_system_gate(3,&int3);
0a521588
JB		 882 set_system_gate(4,&overflow); /* int4 can be called from all */
883 set_intr_gate(5,&bounds);
1da177e4
LT		 884 set_intr_gate(6,&invalid_op);
885 set_intr_gate(7,&device_not_available);
886 set_intr_gate_ist(8,&double_fault, DOUBLEFAULT_STACK);
887 set_intr_gate(9,&coprocessor_segment_overrun);
888 set_intr_gate(10,&invalid_TSS);
889 set_intr_gate(11,&segment_not_present);
890 set_intr_gate_ist(12,&stack_segment,STACKFAULT_STACK);
891 set_intr_gate(13,&general_protection);
892 set_intr_gate(14,&page_fault);
893 set_intr_gate(15,&spurious_interrupt_bug);
894 set_intr_gate(16,&coprocessor_error);
895 set_intr_gate(17,&alignment_check);
896#ifdef CONFIG_X86_MCE
897 set_intr_gate_ist(18,&machine_check, MCE_STACK);
898#endif
899 set_intr_gate(19,&simd_coprocessor_error);
900
901#ifdef CONFIG_IA32_EMULATION
902 set_system_gate(IA32_SYSCALL_VECTOR, ia32_syscall);
903#endif
904
905 set_intr_gate(KDB_VECTOR, call_debug);
906
907 /*
908 * Should be a barrier for any external CPU state.
909 */
910 cpu_init();
911}
912
913
914/* Actual parsing is done early in setup.c. */
915static int __init oops_dummy(char *s)
916{
917 panic_on_oops = 1;
918 return -1;
919}
920__setup("oops=", oops_dummy);
921
922static int __init kstack_setup(char *s)
923{
924 kstack_depth_to_print = simple_strtoul(s,NULL,0);
925 return 0;
926}
927__setup("kstack=", kstack_setup);
928
Ubuntu combined Linux kernel mirror