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Linux 2.6.25-rc4
[linux-2.6/next.git] / arch / ia64 / kernel / traps.c
blobf0cda765e681d1252347675d45f582f8ab470b65
1 /*
2 * Architecture-specific trap handling.
3 *
4 * Copyright (C) 1998-2003 Hewlett-Packard Co
5 * David Mosberger-Tang <davidm@hpl.hp.com>
6 *
7 * 05/12/00 grao <goutham.rao@intel.com> : added isr in siginfo for SIGFPE
8 */
9
10 #include <linux/kernel.h>
11 #include <linux/init.h>
12 #include <linux/sched.h>
13 #include <linux/tty.h>
14 #include <linux/vt_kern.h> /* For unblank_screen() */
15 #include <linux/module.h> /* for EXPORT_SYMBOL */
16 #include <linux/hardirq.h>
17 #include <linux/kprobes.h>
18 #include <linux/delay.h> /* for ssleep() */
19 #include <linux/kdebug.h>
20
21 #include <asm/fpswa.h>
22 #include <asm/ia32.h>
23 #include <asm/intrinsics.h>
24 #include <asm/processor.h>
25 #include <asm/uaccess.h>
26
27 fpswa_interface_t *fpswa_interface;
28 EXPORT_SYMBOL(fpswa_interface);
29
30 void __init
31 trap_init (void)
32 {
33 if (ia64_boot_param->fpswa)
34 /* FPSWA fixup: make the interface pointer a kernel virtual address: */
35 fpswa_interface = __va(ia64_boot_param->fpswa);
36 }
37
38 int
39 die (const char *str, struct pt_regs *regs, long err)
40 {
41 static struct {
42 spinlock_t lock;
43 u32 lock_owner;
44 int lock_owner_depth;
45 } die = {
46 .lock = __SPIN_LOCK_UNLOCKED(die.lock),
47 .lock_owner = -1,
48 .lock_owner_depth = 0
49 };
50 static int die_counter;
51 int cpu = get_cpu();
52
53 if (die.lock_owner != cpu) {
54 console_verbose();
55 spin_lock_irq(&die.lock);
56 die.lock_owner = cpu;
57 die.lock_owner_depth = 0;
58 bust_spinlocks(1);
59 }
60 put_cpu();
61
62 if (++die.lock_owner_depth < 3) {
63 printk("%s[%d]: %s %ld [%d]\n",
64 current->comm, task_pid_nr(current), str, err, ++die_counter);
65 if (notify_die(DIE_OOPS, str, regs, err, 255, SIGSEGV)
66 != NOTIFY_STOP)
67 show_regs(regs);
68 else
69 regs = NULL;
70 } else
71 printk(KERN_ERR "Recursive die() failure, output suppressed\n");
72
73 bust_spinlocks(0);
74 die.lock_owner = -1;
75 add_taint(TAINT_DIE);
76 spin_unlock_irq(&die.lock);
77
78 if (!regs)
79 return 1;
80
81 if (panic_on_oops)
82 panic("Fatal exception");
83
84 do_exit(SIGSEGV);
85 return 0;
86 }
87
88 int
89 die_if_kernel (char *str, struct pt_regs *regs, long err)
90 {
91 if (!user_mode(regs))
92 return die(str, regs, err);
93 return 0;
94 }
95
96 void
97 __kprobes ia64_bad_break (unsigned long break_num, struct pt_regs *regs)
98 {
99 siginfo_t siginfo;
100 int sig, code;
101
102 /* SIGILL, SIGFPE, SIGSEGV, and SIGBUS want these field initialized: */
103 siginfo.si_addr = (void __user *) (regs->cr_iip + ia64_psr(regs)->ri);
104 siginfo.si_imm = break_num;
105 siginfo.si_flags = 0; /* clear __ISR_VALID */
106 siginfo.si_isr = 0;
107
108 switch (break_num) {
109 case 0: /* unknown error (used by GCC for __builtin_abort()) */
110 if (notify_die(DIE_BREAK, "break 0", regs, break_num, TRAP_BRKPT, SIGTRAP)
111 == NOTIFY_STOP)
112 return;
113 if (die_if_kernel("bugcheck!", regs, break_num))
114 return;
115 sig = SIGILL; code = ILL_ILLOPC;
116 break;
117
118 case 1: /* integer divide by zero */
119 sig = SIGFPE; code = FPE_INTDIV;
120 break;
121
122 case 2: /* integer overflow */
123 sig = SIGFPE; code = FPE_INTOVF;
124 break;
125
126 case 3: /* range check/bounds check */
127 sig = SIGFPE; code = FPE_FLTSUB;
128 break;
129
130 case 4: /* null pointer dereference */
131 sig = SIGSEGV; code = SEGV_MAPERR;
132 break;
133
134 case 5: /* misaligned data */
135 sig = SIGSEGV; code = BUS_ADRALN;
136 break;
137
138 case 6: /* decimal overflow */
139 sig = SIGFPE; code = __FPE_DECOVF;
140 break;
141
142 case 7: /* decimal divide by zero */
143 sig = SIGFPE; code = __FPE_DECDIV;
144 break;
145
146 case 8: /* packed decimal error */
147 sig = SIGFPE; code = __FPE_DECERR;
148 break;
149
150 case 9: /* invalid ASCII digit */
151 sig = SIGFPE; code = __FPE_INVASC;
152 break;
153
154 case 10: /* invalid decimal digit */
155 sig = SIGFPE; code = __FPE_INVDEC;
156 break;
157
158 case 11: /* paragraph stack overflow */
159 sig = SIGSEGV; code = __SEGV_PSTKOVF;
160 break;
161
162 case 0x3f000 ... 0x3ffff: /* bundle-update in progress */
163 sig = SIGILL; code = __ILL_BNDMOD;
164 break;
165
166 default:
167 if ((break_num < 0x40000 || break_num > 0x100000)
168 && die_if_kernel("Bad break", regs, break_num))
169 return;
170
171 if (break_num < 0x80000) {
172 sig = SIGILL; code = __ILL_BREAK;
173 } else {
174 if (notify_die(DIE_BREAK, "bad break", regs, break_num, TRAP_BRKPT, SIGTRAP)
175 == NOTIFY_STOP)
176 return;
177 sig = SIGTRAP; code = TRAP_BRKPT;
178 }
179 }
180 siginfo.si_signo = sig;
181 siginfo.si_errno = 0;
182 siginfo.si_code = code;
183 force_sig_info(sig, &siginfo, current);
184 }
185
186 /*
187 * disabled_fph_fault() is called when a user-level process attempts to access f32..f127
188 * and it doesn't own the fp-high register partition. When this happens, we save the
189 * current fph partition in the task_struct of the fpu-owner (if necessary) and then load
190 * the fp-high partition of the current task (if necessary). Note that the kernel has
191 * access to fph by the time we get here, as the IVT's "Disabled FP-Register" handler takes
192 * care of clearing psr.dfh.
193 */
194 static inline void
195 disabled_fph_fault (struct pt_regs *regs)
196 {
197 struct ia64_psr *psr = ia64_psr(regs);
198
199 /* first, grant user-level access to fph partition: */
200 psr->dfh = 0;
201
202 /*
203 * Make sure that no other task gets in on this processor
204 * while we're claiming the FPU
205 */
206 preempt_disable();
207 #ifndef CONFIG_SMP
208 {
209 struct task_struct *fpu_owner
210 = (struct task_struct *)ia64_get_kr(IA64_KR_FPU_OWNER);
211
212 if (ia64_is_local_fpu_owner(current)) {
213 preempt_enable_no_resched();
214 return;
215 }
216
217 if (fpu_owner)
218 ia64_flush_fph(fpu_owner);
219 }
220 #endif /* !CONFIG_SMP */
221 ia64_set_local_fpu_owner(current);
222 if ((current->thread.flags & IA64_THREAD_FPH_VALID) != 0) {
223 __ia64_load_fpu(current->thread.fph);
224 psr->mfh = 0;
225 } else {
226 __ia64_init_fpu();
227 /*
228 * Set mfh because the state in thread.fph does not match the state in
229 * the fph partition.
230 */
231 psr->mfh = 1;
232 }
233 preempt_enable_no_resched();
234 }
235
236 static inline int
237 fp_emulate (int fp_fault, void *bundle, long *ipsr, long *fpsr, long *isr, long *pr, long *ifs,
238 struct pt_regs *regs)
239 {
240 fp_state_t fp_state;
241 fpswa_ret_t ret;
242
243 if (!fpswa_interface)
244 return -1;
245
246 memset(&fp_state, 0, sizeof(fp_state_t));
247
248 /*
249 * compute fp_state. only FP registers f6 - f11 are used by the
250 * kernel, so set those bits in the mask and set the low volatile
251 * pointer to point to these registers.
252 */
253 fp_state.bitmask_low64 = 0xfc0; /* bit6..bit11 */
254
255 fp_state.fp_state_low_volatile = (fp_state_low_volatile_t *) &regs->f6;
256 /*
257 * unsigned long (*EFI_FPSWA) (
258 * unsigned long trap_type,
259 * void *Bundle,
260 * unsigned long *pipsr,
261 * unsigned long *pfsr,
262 * unsigned long *pisr,
263 * unsigned long *ppreds,
264 * unsigned long *pifs,
265 * void *fp_state);
266 */
267 ret = (*fpswa_interface->fpswa)((unsigned long) fp_fault, bundle,
268 (unsigned long *) ipsr, (unsigned long *) fpsr,
269 (unsigned long *) isr, (unsigned long *) pr,
270 (unsigned long *) ifs, &fp_state);
271
272 return ret.status;
273 }
274
275 struct fpu_swa_msg {
276 unsigned long count;
277 unsigned long time;
278 };
279 static DEFINE_PER_CPU(struct fpu_swa_msg, cpulast);
280 DECLARE_PER_CPU(struct fpu_swa_msg, cpulast);
281 static struct fpu_swa_msg last __cacheline_aligned;
282
283
284 /*
285 * Handle floating-point assist faults and traps.
286 */
287 static int
288 handle_fpu_swa (int fp_fault, struct pt_regs *regs, unsigned long isr)
289 {
290 long exception, bundle[2];
291 unsigned long fault_ip;
292 struct siginfo siginfo;
293
294 fault_ip = regs->cr_iip;
295 if (!fp_fault && (ia64_psr(regs)->ri == 0))
296 fault_ip -= 16;
297 if (copy_from_user(bundle, (void __user *) fault_ip, sizeof(bundle)))
298 return -1;
299
300 if (!(current->thread.flags & IA64_THREAD_FPEMU_NOPRINT)) {
301 unsigned long count, current_jiffies = jiffies;
302 struct fpu_swa_msg *cp = &__get_cpu_var(cpulast);
303
304 if (unlikely(current_jiffies > cp->time))
305 cp->count = 0;
306 if (unlikely(cp->count < 5)) {
307 cp->count++;
308 cp->time = current_jiffies + 5 * HZ;
309
310 /* minimize races by grabbing a copy of count BEFORE checking last.time. */
311 count = last.count;
312 barrier();
313
314 /*
315 * Lower 4 bits are used as a count. Upper bits are a sequence
316 * number that is updated when count is reset. The cmpxchg will
317 * fail is seqno has changed. This minimizes mutiple cpus
318 * resetting the count.
319 */
320 if (current_jiffies > last.time)
321 (void) cmpxchg_acq(&last.count, count, 16 + (count & ~15));
322
323 /* used fetchadd to atomically update the count */
324 if ((last.count & 15) < 5 && (ia64_fetchadd(1, &last.count, acq) & 15) < 5) {
325 last.time = current_jiffies + 5 * HZ;
326 printk(KERN_WARNING
327 "%s(%d): floating-point assist fault at ip %016lx, isr %016lx\n",
328 current->comm, task_pid_nr(current), regs->cr_iip + ia64_psr(regs)->ri, isr);
329 }
330 }
331 }
332
333 exception = fp_emulate(fp_fault, bundle, &regs->cr_ipsr, &regs->ar_fpsr, &isr, &regs->pr,
334 &regs->cr_ifs, regs);
335 if (fp_fault) {
336 if (exception == 0) {
337 /* emulation was successful */
338 ia64_increment_ip(regs);
339 } else if (exception == -1) {
340 printk(KERN_ERR "handle_fpu_swa: fp_emulate() returned -1\n");
341 return -1;
342 } else {
343 /* is next instruction a trap? */
344 if (exception & 2) {
345 ia64_increment_ip(regs);
346 }
347 siginfo.si_signo = SIGFPE;
348 siginfo.si_errno = 0;
349 siginfo.si_code = __SI_FAULT; /* default code */
350 siginfo.si_addr = (void __user *) (regs->cr_iip + ia64_psr(regs)->ri);
351 if (isr & 0x11) {
352 siginfo.si_code = FPE_FLTINV;
353 } else if (isr & 0x22) {
354 /* denormal operand gets the same si_code as underflow
355 * see arch/i386/kernel/traps.c:math_error() */
356 siginfo.si_code = FPE_FLTUND;
357 } else if (isr & 0x44) {
358 siginfo.si_code = FPE_FLTDIV;
359 }
360 siginfo.si_isr = isr;
361 siginfo.si_flags = __ISR_VALID;
362 siginfo.si_imm = 0;
363 force_sig_info(SIGFPE, &siginfo, current);
364 }
365 } else {
366 if (exception == -1) {
367 printk(KERN_ERR "handle_fpu_swa: fp_emulate() returned -1\n");
368 return -1;
369 } else if (exception != 0) {
370 /* raise exception */
371 siginfo.si_signo = SIGFPE;
372 siginfo.si_errno = 0;
373 siginfo.si_code = __SI_FAULT; /* default code */
374 siginfo.si_addr = (void __user *) (regs->cr_iip + ia64_psr(regs)->ri);
375 if (isr & 0x880) {
376 siginfo.si_code = FPE_FLTOVF;
377 } else if (isr & 0x1100) {
378 siginfo.si_code = FPE_FLTUND;
379 } else if (isr & 0x2200) {
380 siginfo.si_code = FPE_FLTRES;
381 }
382 siginfo.si_isr = isr;
383 siginfo.si_flags = __ISR_VALID;
384 siginfo.si_imm = 0;
385 force_sig_info(SIGFPE, &siginfo, current);
386 }
387 }
388 return 0;
389 }
390
391 struct illegal_op_return {
392 unsigned long fkt, arg1, arg2, arg3;
393 };
394
395 struct illegal_op_return
396 ia64_illegal_op_fault (unsigned long ec, long arg1, long arg2, long arg3,
397 long arg4, long arg5, long arg6, long arg7,
398 struct pt_regs regs)
399 {
400 struct illegal_op_return rv;
401 struct siginfo si;
402 char buf[128];
403
404 #ifdef CONFIG_IA64_BRL_EMU
405 {
406 extern struct illegal_op_return ia64_emulate_brl (struct pt_regs *, unsigned long);
407
408 rv = ia64_emulate_brl(&regs, ec);
409 if (rv.fkt != (unsigned long) -1)
410 return rv;
411 }
412 #endif
413
414 sprintf(buf, "IA-64 Illegal operation fault");
415 rv.fkt = 0;
416 if (die_if_kernel(buf, &regs, 0))
417 return rv;
418
419 memset(&si, 0, sizeof(si));
420 si.si_signo = SIGILL;
421 si.si_code = ILL_ILLOPC;
422 si.si_addr = (void __user *) (regs.cr_iip + ia64_psr(&regs)->ri);
423 force_sig_info(SIGILL, &si, current);
424 return rv;
425 }
426
427 void __kprobes
428 ia64_fault (unsigned long vector, unsigned long isr, unsigned long ifa,
429 unsigned long iim, unsigned long itir, long arg5, long arg6,
430 long arg7, struct pt_regs regs)
431 {
432 unsigned long code, error = isr, iip;
433 struct siginfo siginfo;
434 char buf[128];
435 int result, sig;
436 static const char *reason[] = {
437 "IA-64 Illegal Operation fault",
438 "IA-64 Privileged Operation fault",
439 "IA-64 Privileged Register fault",
440 "IA-64 Reserved Register/Field fault",
441 "Disabled Instruction Set Transition fault",
442 "Unknown fault 5", "Unknown fault 6", "Unknown fault 7", "Illegal Hazard fault",
443 "Unknown fault 9", "Unknown fault 10", "Unknown fault 11", "Unknown fault 12",
444 "Unknown fault 13", "Unknown fault 14", "Unknown fault 15"
445 };
446
447 if ((isr & IA64_ISR_NA) && ((isr & IA64_ISR_CODE_MASK) == IA64_ISR_CODE_LFETCH)) {
448 /*
449 * This fault was due to lfetch.fault, set "ed" bit in the psr to cancel
450 * the lfetch.
451 */
452 ia64_psr(&regs)->ed = 1;
453 return;
454 }
455
456 iip = regs.cr_iip + ia64_psr(&regs)->ri;
457
458 switch (vector) {
459 case 24: /* General Exception */
460 code = (isr >> 4) & 0xf;
461 sprintf(buf, "General Exception: %s%s", reason[code],
462 (code == 3) ? ((isr & (1UL << 37))
463 ? " (RSE access)" : " (data access)") : "");
464 if (code == 8) {
465 # ifdef CONFIG_IA64_PRINT_HAZARDS
466 printk("%s[%d]: possible hazard @ ip=%016lx (pr = %016lx)\n",
467 current->comm, task_pid_nr(current),
468 regs.cr_iip + ia64_psr(&regs)->ri, regs.pr);
469 # endif
470 return;
471 }
472 break;
473
474 case 25: /* Disabled FP-Register */
475 if (isr & 2) {
476 disabled_fph_fault(&regs);
477 return;
478 }
479 sprintf(buf, "Disabled FPL fault---not supposed to happen!");
480 break;
481
482 case 26: /* NaT Consumption */
483 if (user_mode(&regs)) {
484 void __user *addr;
485
486 if (((isr >> 4) & 0xf) == 2) {
487 /* NaT page consumption */
488 sig = SIGSEGV;
489 code = SEGV_ACCERR;
490 addr = (void __user *) ifa;
491 } else {
492 /* register NaT consumption */
493 sig = SIGILL;
494 code = ILL_ILLOPN;
495 addr = (void __user *) (regs.cr_iip
496 + ia64_psr(&regs)->ri);
497 }
498 siginfo.si_signo = sig;
499 siginfo.si_code = code;
500 siginfo.si_errno = 0;
501 siginfo.si_addr = addr;
502 siginfo.si_imm = vector;
503 siginfo.si_flags = __ISR_VALID;
504 siginfo.si_isr = isr;
505 force_sig_info(sig, &siginfo, current);
506 return;
507 } else if (ia64_done_with_exception(&regs))
508 return;
509 sprintf(buf, "NaT consumption");
510 break;
511
512 case 31: /* Unsupported Data Reference */
513 if (user_mode(&regs)) {
514 siginfo.si_signo = SIGILL;
515 siginfo.si_code = ILL_ILLOPN;
516 siginfo.si_errno = 0;
517 siginfo.si_addr = (void __user *) iip;
518 siginfo.si_imm = vector;
519 siginfo.si_flags = __ISR_VALID;
520 siginfo.si_isr = isr;
521 force_sig_info(SIGILL, &siginfo, current);
522 return;
523 }
524 sprintf(buf, "Unsupported data reference");
525 break;
526
527 case 29: /* Debug */
528 case 35: /* Taken Branch Trap */
529 case 36: /* Single Step Trap */
530 if (fsys_mode(current, &regs)) {
531 extern char __kernel_syscall_via_break[];
532 /*
533 * Got a trap in fsys-mode: Taken Branch Trap
534 * and Single Step trap need special handling;
535 * Debug trap is ignored (we disable it here
536 * and re-enable it in the lower-privilege trap).
537 */
538 if (unlikely(vector == 29)) {
539 set_thread_flag(TIF_DB_DISABLED);
540 ia64_psr(&regs)->db = 0;
541 ia64_psr(&regs)->lp = 1;
542 return;
543 }
544 /* re-do the system call via break 0x100000: */
545 regs.cr_iip = (unsigned long) __kernel_syscall_via_break;
546 ia64_psr(&regs)->ri = 0;
547 ia64_psr(&regs)->cpl = 3;
548 return;
549 }
550 switch (vector) {
551 case 29:
552 siginfo.si_code = TRAP_HWBKPT;
553 #ifdef CONFIG_ITANIUM
554 /*
555 * Erratum 10 (IFA may contain incorrect address) now has
556 * "NoFix" status. There are no plans for fixing this.
557 */
558 if (ia64_psr(&regs)->is == 0)
559 ifa = regs.cr_iip;
560 #endif
561 break;
562 case 35: siginfo.si_code = TRAP_BRANCH; ifa = 0; break;
563 case 36: siginfo.si_code = TRAP_TRACE; ifa = 0; break;
564 }
565 if (notify_die(DIE_FAULT, "ia64_fault", &regs, vector, siginfo.si_code, SIGTRAP)
566 == NOTIFY_STOP)
567 return;
568 siginfo.si_signo = SIGTRAP;
569 siginfo.si_errno = 0;
570 siginfo.si_addr = (void __user *) ifa;
571 siginfo.si_imm = 0;
572 siginfo.si_flags = __ISR_VALID;
573 siginfo.si_isr = isr;
574 force_sig_info(SIGTRAP, &siginfo, current);
575 return;
576
577 case 32: /* fp fault */
578 case 33: /* fp trap */
579 result = handle_fpu_swa((vector == 32) ? 1 : 0, &regs, isr);
580 if ((result < 0) || (current->thread.flags & IA64_THREAD_FPEMU_SIGFPE)) {
581 siginfo.si_signo = SIGFPE;
582 siginfo.si_errno = 0;
583 siginfo.si_code = FPE_FLTINV;
584 siginfo.si_addr = (void __user *) iip;
585 siginfo.si_flags = __ISR_VALID;
586 siginfo.si_isr = isr;
587 siginfo.si_imm = 0;
588 force_sig_info(SIGFPE, &siginfo, current);
589 }
590 return;
591
592 case 34:
593 if (isr & 0x2) {
594 /* Lower-Privilege Transfer Trap */
595
596 /* If we disabled debug traps during an fsyscall,
597 * re-enable them here.
598 */
599 if (test_thread_flag(TIF_DB_DISABLED)) {
600 clear_thread_flag(TIF_DB_DISABLED);
601 ia64_psr(&regs)->db = 1;
602 }
603
604 /*
605 * Just clear PSR.lp and then return immediately:
606 * all the interesting work (e.g., signal delivery)
607 * is done in the kernel exit path.
608 */
609 ia64_psr(&regs)->lp = 0;
610 return;
611 } else {
612 /* Unimplemented Instr. Address Trap */
613 if (user_mode(&regs)) {
614 siginfo.si_signo = SIGILL;
615 siginfo.si_code = ILL_BADIADDR;
616 siginfo.si_errno = 0;
617 siginfo.si_flags = 0;
618 siginfo.si_isr = 0;
619 siginfo.si_imm = 0;
620 siginfo.si_addr = (void __user *) iip;
621 force_sig_info(SIGILL, &siginfo, current);
622 return;
623 }
624 sprintf(buf, "Unimplemented Instruction Address fault");
625 }
626 break;
627
628 case 45:
629 #ifdef CONFIG_IA32_SUPPORT
630 if (ia32_exception(&regs, isr) == 0)
631 return;
632 #endif
633 printk(KERN_ERR "Unexpected IA-32 exception (Trap 45)\n");
634 printk(KERN_ERR " iip - 0x%lx, ifa - 0x%lx, isr - 0x%lx\n",
635 iip, ifa, isr);
636 force_sig(SIGSEGV, current);
637 break;
638
639 case 46:
640 #ifdef CONFIG_IA32_SUPPORT
641 if (ia32_intercept(&regs, isr) == 0)
642 return;
643 #endif
644 printk(KERN_ERR "Unexpected IA-32 intercept trap (Trap 46)\n");
645 printk(KERN_ERR " iip - 0x%lx, ifa - 0x%lx, isr - 0x%lx, iim - 0x%lx\n",
646 iip, ifa, isr, iim);
647 force_sig(SIGSEGV, current);
648 return;
649
650 case 47:
651 sprintf(buf, "IA-32 Interruption Fault (int 0x%lx)", isr >> 16);
652 break;
653
654 default:
655 sprintf(buf, "Fault %lu", vector);
656 break;
657 }
658 if (!die_if_kernel(buf, &regs, error))
659 force_sig(SIGILL, current);
660 }
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