Merge branch 'master'
[deliverable/linux.git] / arch / ia64 / kernel / traps.c
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/config.h>
11 #include <linux/kernel.h>
12 #include <linux/init.h>
13 #include <linux/sched.h>
14 #include <linux/tty.h>
15 #include <linux/vt_kern.h> /* For unblank_screen() */
16 #include <linux/module.h> /* for EXPORT_SYMBOL */
17 #include <linux/hardirq.h>
18 #include <linux/kprobes.h>
19
20 #include <asm/fpswa.h>
21 #include <asm/ia32.h>
22 #include <asm/intrinsics.h>
23 #include <asm/processor.h>
24 #include <asm/uaccess.h>
25 #include <asm/kdebug.h>
26
27 extern spinlock_t timerlist_lock;
28
29 fpswa_interface_t *fpswa_interface;
30 EXPORT_SYMBOL(fpswa_interface);
31
32 struct notifier_block *ia64die_chain;
33
34 int
35 register_die_notifier(struct notifier_block *nb)
36 {
37 return notifier_chain_register(&ia64die_chain, nb);
38 }
39 EXPORT_SYMBOL_GPL(register_die_notifier);
40
41 int
42 unregister_die_notifier(struct notifier_block *nb)
43 {
44 return notifier_chain_unregister(&ia64die_chain, nb);
45 }
46 EXPORT_SYMBOL_GPL(unregister_die_notifier);
47
48 void __init
49 trap_init (void)
50 {
51 if (ia64_boot_param->fpswa)
52 /* FPSWA fixup: make the interface pointer a kernel virtual address: */
53 fpswa_interface = __va(ia64_boot_param->fpswa);
54 }
55
56 /*
57 * Unlock any spinlocks which will prevent us from getting the message out (timerlist_lock
58 * is acquired through the console unblank code)
59 */
60 void
61 bust_spinlocks (int yes)
62 {
63 int loglevel_save = console_loglevel;
64
65 if (yes) {
66 oops_in_progress = 1;
67 return;
68 }
69
70 #ifdef CONFIG_VT
71 unblank_screen();
72 #endif
73 oops_in_progress = 0;
74 /*
75 * OK, the message is on the console. Now we call printk() without
76 * oops_in_progress set so that printk will give klogd a poke. Hold onto
77 * your hats...
78 */
79 console_loglevel = 15; /* NMI oopser may have shut the console up */
80 printk(" ");
81 console_loglevel = loglevel_save;
82 }
83
84 void
85 die (const char *str, struct pt_regs *regs, long err)
86 {
87 static struct {
88 spinlock_t lock;
89 u32 lock_owner;
90 int lock_owner_depth;
91 } die = {
92 .lock = SPIN_LOCK_UNLOCKED,
93 .lock_owner = -1,
94 .lock_owner_depth = 0
95 };
96 static int die_counter;
97 int cpu = get_cpu();
98
99 if (die.lock_owner != cpu) {
100 console_verbose();
101 spin_lock_irq(&die.lock);
102 die.lock_owner = cpu;
103 die.lock_owner_depth = 0;
104 bust_spinlocks(1);
105 }
106 put_cpu();
107
108 if (++die.lock_owner_depth < 3) {
109 printk("%s[%d]: %s %ld [%d]\n",
110 current->comm, current->pid, str, err, ++die_counter);
111 (void) notify_die(DIE_OOPS, (char *)str, regs, err, 255, SIGSEGV);
112 show_regs(regs);
113 } else
114 printk(KERN_ERR "Recursive die() failure, output suppressed\n");
115
116 bust_spinlocks(0);
117 die.lock_owner = -1;
118 spin_unlock_irq(&die.lock);
119 do_exit(SIGSEGV);
120 }
121
122 void
123 die_if_kernel (char *str, struct pt_regs *regs, long err)
124 {
125 if (!user_mode(regs))
126 die(str, regs, err);
127 }
128
129 void
130 __kprobes ia64_bad_break (unsigned long break_num, struct pt_regs *regs)
131 {
132 siginfo_t siginfo;
133 int sig, code;
134
135 /* break.b always sets cr.iim to 0, which causes problems for
136 * debuggers. Get the real break number from the original instruction,
137 * but only for kernel code. User space break.b is left alone, to
138 * preserve the existing behaviour. All break codings have the same
139 * format, so there is no need to check the slot type.
140 */
141 if (break_num == 0 && !user_mode(regs)) {
142 struct ia64_psr *ipsr = ia64_psr(regs);
143 unsigned long *bundle = (unsigned long *)regs->cr_iip;
144 unsigned long slot;
145 switch (ipsr->ri) {
146 case 0: slot = (bundle[0] >> 5); break;
147 case 1: slot = (bundle[0] >> 46) | (bundle[1] << 18); break;
148 default: slot = (bundle[1] >> 23); break;
149 }
150 break_num = ((slot >> 36 & 1) << 20) | (slot >> 6 & 0xfffff);
151 }
152
153 /* SIGILL, SIGFPE, SIGSEGV, and SIGBUS want these field initialized: */
154 siginfo.si_addr = (void __user *) (regs->cr_iip + ia64_psr(regs)->ri);
155 siginfo.si_imm = break_num;
156 siginfo.si_flags = 0; /* clear __ISR_VALID */
157 siginfo.si_isr = 0;
158
159 switch (break_num) {
160 case 0: /* unknown error (used by GCC for __builtin_abort()) */
161 if (notify_die(DIE_BREAK, "break 0", regs, break_num, TRAP_BRKPT, SIGTRAP)
162 == NOTIFY_STOP)
163 return;
164 die_if_kernel("bugcheck!", regs, break_num);
165 sig = SIGILL; code = ILL_ILLOPC;
166 break;
167
168 case 1: /* integer divide by zero */
169 sig = SIGFPE; code = FPE_INTDIV;
170 break;
171
172 case 2: /* integer overflow */
173 sig = SIGFPE; code = FPE_INTOVF;
174 break;
175
176 case 3: /* range check/bounds check */
177 sig = SIGFPE; code = FPE_FLTSUB;
178 break;
179
180 case 4: /* null pointer dereference */
181 sig = SIGSEGV; code = SEGV_MAPERR;
182 break;
183
184 case 5: /* misaligned data */
185 sig = SIGSEGV; code = BUS_ADRALN;
186 break;
187
188 case 6: /* decimal overflow */
189 sig = SIGFPE; code = __FPE_DECOVF;
190 break;
191
192 case 7: /* decimal divide by zero */
193 sig = SIGFPE; code = __FPE_DECDIV;
194 break;
195
196 case 8: /* packed decimal error */
197 sig = SIGFPE; code = __FPE_DECERR;
198 break;
199
200 case 9: /* invalid ASCII digit */
201 sig = SIGFPE; code = __FPE_INVASC;
202 break;
203
204 case 10: /* invalid decimal digit */
205 sig = SIGFPE; code = __FPE_INVDEC;
206 break;
207
208 case 11: /* paragraph stack overflow */
209 sig = SIGSEGV; code = __SEGV_PSTKOVF;
210 break;
211
212 case 0x3f000 ... 0x3ffff: /* bundle-update in progress */
213 sig = SIGILL; code = __ILL_BNDMOD;
214 break;
215
216 default:
217 if (break_num < 0x40000 || break_num > 0x100000)
218 die_if_kernel("Bad break", regs, break_num);
219
220 if (break_num < 0x80000) {
221 sig = SIGILL; code = __ILL_BREAK;
222 } else {
223 if (notify_die(DIE_BREAK, "bad break", regs, break_num, TRAP_BRKPT, SIGTRAP)
224 == NOTIFY_STOP)
225 return;
226 sig = SIGTRAP; code = TRAP_BRKPT;
227 }
228 }
229 siginfo.si_signo = sig;
230 siginfo.si_errno = 0;
231 siginfo.si_code = code;
232 force_sig_info(sig, &siginfo, current);
233 }
234
235 /*
236 * disabled_fph_fault() is called when a user-level process attempts to access f32..f127
237 * and it doesn't own the fp-high register partition. When this happens, we save the
238 * current fph partition in the task_struct of the fpu-owner (if necessary) and then load
239 * the fp-high partition of the current task (if necessary). Note that the kernel has
240 * access to fph by the time we get here, as the IVT's "Disabled FP-Register" handler takes
241 * care of clearing psr.dfh.
242 */
243 static inline void
244 disabled_fph_fault (struct pt_regs *regs)
245 {
246 struct ia64_psr *psr = ia64_psr(regs);
247
248 /* first, grant user-level access to fph partition: */
249 psr->dfh = 0;
250
251 /*
252 * Make sure that no other task gets in on this processor
253 * while we're claiming the FPU
254 */
255 preempt_disable();
256 #ifndef CONFIG_SMP
257 {
258 struct task_struct *fpu_owner
259 = (struct task_struct *)ia64_get_kr(IA64_KR_FPU_OWNER);
260
261 if (ia64_is_local_fpu_owner(current)) {
262 preempt_enable_no_resched();
263 return;
264 }
265
266 if (fpu_owner)
267 ia64_flush_fph(fpu_owner);
268 }
269 #endif /* !CONFIG_SMP */
270 ia64_set_local_fpu_owner(current);
271 if ((current->thread.flags & IA64_THREAD_FPH_VALID) != 0) {
272 __ia64_load_fpu(current->thread.fph);
273 psr->mfh = 0;
274 } else {
275 __ia64_init_fpu();
276 /*
277 * Set mfh because the state in thread.fph does not match the state in
278 * the fph partition.
279 */
280 psr->mfh = 1;
281 }
282 preempt_enable_no_resched();
283 }
284
285 static inline int
286 fp_emulate (int fp_fault, void *bundle, long *ipsr, long *fpsr, long *isr, long *pr, long *ifs,
287 struct pt_regs *regs)
288 {
289 fp_state_t fp_state;
290 fpswa_ret_t ret;
291
292 if (!fpswa_interface)
293 return -1;
294
295 memset(&fp_state, 0, sizeof(fp_state_t));
296
297 /*
298 * compute fp_state. only FP registers f6 - f11 are used by the
299 * kernel, so set those bits in the mask and set the low volatile
300 * pointer to point to these registers.
301 */
302 fp_state.bitmask_low64 = 0xfc0; /* bit6..bit11 */
303
304 fp_state.fp_state_low_volatile = (fp_state_low_volatile_t *) &regs->f6;
305 /*
306 * unsigned long (*EFI_FPSWA) (
307 * unsigned long trap_type,
308 * void *Bundle,
309 * unsigned long *pipsr,
310 * unsigned long *pfsr,
311 * unsigned long *pisr,
312 * unsigned long *ppreds,
313 * unsigned long *pifs,
314 * void *fp_state);
315 */
316 ret = (*fpswa_interface->fpswa)((unsigned long) fp_fault, bundle,
317 (unsigned long *) ipsr, (unsigned long *) fpsr,
318 (unsigned long *) isr, (unsigned long *) pr,
319 (unsigned long *) ifs, &fp_state);
320
321 return ret.status;
322 }
323
324 /*
325 * Handle floating-point assist faults and traps.
326 */
327 static int
328 handle_fpu_swa (int fp_fault, struct pt_regs *regs, unsigned long isr)
329 {
330 long exception, bundle[2];
331 unsigned long fault_ip;
332 struct siginfo siginfo;
333 static int fpu_swa_count = 0;
334 static unsigned long last_time;
335
336 fault_ip = regs->cr_iip;
337 if (!fp_fault && (ia64_psr(regs)->ri == 0))
338 fault_ip -= 16;
339 if (copy_from_user(bundle, (void __user *) fault_ip, sizeof(bundle)))
340 return -1;
341
342 if (jiffies - last_time > 5*HZ)
343 fpu_swa_count = 0;
344 if ((fpu_swa_count < 4) && !(current->thread.flags & IA64_THREAD_FPEMU_NOPRINT)) {
345 last_time = jiffies;
346 ++fpu_swa_count;
347 printk(KERN_WARNING
348 "%s(%d): floating-point assist fault at ip %016lx, isr %016lx\n",
349 current->comm, current->pid, regs->cr_iip + ia64_psr(regs)->ri, isr);
350 }
351
352 exception = fp_emulate(fp_fault, bundle, &regs->cr_ipsr, &regs->ar_fpsr, &isr, &regs->pr,
353 &regs->cr_ifs, regs);
354 if (fp_fault) {
355 if (exception == 0) {
356 /* emulation was successful */
357 ia64_increment_ip(regs);
358 } else if (exception == -1) {
359 printk(KERN_ERR "handle_fpu_swa: fp_emulate() returned -1\n");
360 return -1;
361 } else {
362 /* is next instruction a trap? */
363 if (exception & 2) {
364 ia64_increment_ip(regs);
365 }
366 siginfo.si_signo = SIGFPE;
367 siginfo.si_errno = 0;
368 siginfo.si_code = __SI_FAULT; /* default code */
369 siginfo.si_addr = (void __user *) (regs->cr_iip + ia64_psr(regs)->ri);
370 if (isr & 0x11) {
371 siginfo.si_code = FPE_FLTINV;
372 } else if (isr & 0x22) {
373 /* denormal operand gets the same si_code as underflow
374 * see arch/i386/kernel/traps.c:math_error() */
375 siginfo.si_code = FPE_FLTUND;
376 } else if (isr & 0x44) {
377 siginfo.si_code = FPE_FLTDIV;
378 }
379 siginfo.si_isr = isr;
380 siginfo.si_flags = __ISR_VALID;
381 siginfo.si_imm = 0;
382 force_sig_info(SIGFPE, &siginfo, current);
383 }
384 } else {
385 if (exception == -1) {
386 printk(KERN_ERR "handle_fpu_swa: fp_emulate() returned -1\n");
387 return -1;
388 } else if (exception != 0) {
389 /* raise exception */
390 siginfo.si_signo = SIGFPE;
391 siginfo.si_errno = 0;
392 siginfo.si_code = __SI_FAULT; /* default code */
393 siginfo.si_addr = (void __user *) (regs->cr_iip + ia64_psr(regs)->ri);
394 if (isr & 0x880) {
395 siginfo.si_code = FPE_FLTOVF;
396 } else if (isr & 0x1100) {
397 siginfo.si_code = FPE_FLTUND;
398 } else if (isr & 0x2200) {
399 siginfo.si_code = FPE_FLTRES;
400 }
401 siginfo.si_isr = isr;
402 siginfo.si_flags = __ISR_VALID;
403 siginfo.si_imm = 0;
404 force_sig_info(SIGFPE, &siginfo, current);
405 }
406 }
407 return 0;
408 }
409
410 struct illegal_op_return {
411 unsigned long fkt, arg1, arg2, arg3;
412 };
413
414 struct illegal_op_return
415 ia64_illegal_op_fault (unsigned long ec, long arg1, long arg2, long arg3,
416 long arg4, long arg5, long arg6, long arg7,
417 struct pt_regs regs)
418 {
419 struct illegal_op_return rv;
420 struct siginfo si;
421 char buf[128];
422
423 #ifdef CONFIG_IA64_BRL_EMU
424 {
425 extern struct illegal_op_return ia64_emulate_brl (struct pt_regs *, unsigned long);
426
427 rv = ia64_emulate_brl(&regs, ec);
428 if (rv.fkt != (unsigned long) -1)
429 return rv;
430 }
431 #endif
432
433 sprintf(buf, "IA-64 Illegal operation fault");
434 die_if_kernel(buf, &regs, 0);
435
436 memset(&si, 0, sizeof(si));
437 si.si_signo = SIGILL;
438 si.si_code = ILL_ILLOPC;
439 si.si_addr = (void __user *) (regs.cr_iip + ia64_psr(&regs)->ri);
440 force_sig_info(SIGILL, &si, current);
441 rv.fkt = 0;
442 return rv;
443 }
444
445 void __kprobes
446 ia64_fault (unsigned long vector, unsigned long isr, unsigned long ifa,
447 unsigned long iim, unsigned long itir, long arg5, long arg6,
448 long arg7, struct pt_regs regs)
449 {
450 unsigned long code, error = isr, iip;
451 struct siginfo siginfo;
452 char buf[128];
453 int result, sig;
454 static const char *reason[] = {
455 "IA-64 Illegal Operation fault",
456 "IA-64 Privileged Operation fault",
457 "IA-64 Privileged Register fault",
458 "IA-64 Reserved Register/Field fault",
459 "Disabled Instruction Set Transition fault",
460 "Unknown fault 5", "Unknown fault 6", "Unknown fault 7", "Illegal Hazard fault",
461 "Unknown fault 9", "Unknown fault 10", "Unknown fault 11", "Unknown fault 12",
462 "Unknown fault 13", "Unknown fault 14", "Unknown fault 15"
463 };
464
465 if ((isr & IA64_ISR_NA) && ((isr & IA64_ISR_CODE_MASK) == IA64_ISR_CODE_LFETCH)) {
466 /*
467 * This fault was due to lfetch.fault, set "ed" bit in the psr to cancel
468 * the lfetch.
469 */
470 ia64_psr(&regs)->ed = 1;
471 return;
472 }
473
474 iip = regs.cr_iip + ia64_psr(&regs)->ri;
475
476 switch (vector) {
477 case 24: /* General Exception */
478 code = (isr >> 4) & 0xf;
479 sprintf(buf, "General Exception: %s%s", reason[code],
480 (code == 3) ? ((isr & (1UL << 37))
481 ? " (RSE access)" : " (data access)") : "");
482 if (code == 8) {
483 # ifdef CONFIG_IA64_PRINT_HAZARDS
484 printk("%s[%d]: possible hazard @ ip=%016lx (pr = %016lx)\n",
485 current->comm, current->pid,
486 regs.cr_iip + ia64_psr(&regs)->ri, regs.pr);
487 # endif
488 return;
489 }
490 break;
491
492 case 25: /* Disabled FP-Register */
493 if (isr & 2) {
494 disabled_fph_fault(&regs);
495 return;
496 }
497 sprintf(buf, "Disabled FPL fault---not supposed to happen!");
498 break;
499
500 case 26: /* NaT Consumption */
501 if (user_mode(&regs)) {
502 void __user *addr;
503
504 if (((isr >> 4) & 0xf) == 2) {
505 /* NaT page consumption */
506 sig = SIGSEGV;
507 code = SEGV_ACCERR;
508 addr = (void __user *) ifa;
509 } else {
510 /* register NaT consumption */
511 sig = SIGILL;
512 code = ILL_ILLOPN;
513 addr = (void __user *) (regs.cr_iip
514 + ia64_psr(&regs)->ri);
515 }
516 siginfo.si_signo = sig;
517 siginfo.si_code = code;
518 siginfo.si_errno = 0;
519 siginfo.si_addr = addr;
520 siginfo.si_imm = vector;
521 siginfo.si_flags = __ISR_VALID;
522 siginfo.si_isr = isr;
523 force_sig_info(sig, &siginfo, current);
524 return;
525 } else if (ia64_done_with_exception(&regs))
526 return;
527 sprintf(buf, "NaT consumption");
528 break;
529
530 case 31: /* Unsupported Data Reference */
531 if (user_mode(&regs)) {
532 siginfo.si_signo = SIGILL;
533 siginfo.si_code = ILL_ILLOPN;
534 siginfo.si_errno = 0;
535 siginfo.si_addr = (void __user *) iip;
536 siginfo.si_imm = vector;
537 siginfo.si_flags = __ISR_VALID;
538 siginfo.si_isr = isr;
539 force_sig_info(SIGILL, &siginfo, current);
540 return;
541 }
542 sprintf(buf, "Unsupported data reference");
543 break;
544
545 case 29: /* Debug */
546 case 35: /* Taken Branch Trap */
547 case 36: /* Single Step Trap */
548 if (fsys_mode(current, &regs)) {
549 extern char __kernel_syscall_via_break[];
550 /*
551 * Got a trap in fsys-mode: Taken Branch Trap and Single Step trap
552 * need special handling; Debug trap is not supposed to happen.
553 */
554 if (unlikely(vector == 29)) {
555 die("Got debug trap in fsys-mode---not supposed to happen!",
556 &regs, 0);
557 return;
558 }
559 /* re-do the system call via break 0x100000: */
560 regs.cr_iip = (unsigned long) __kernel_syscall_via_break;
561 ia64_psr(&regs)->ri = 0;
562 ia64_psr(&regs)->cpl = 3;
563 return;
564 }
565 switch (vector) {
566 case 29:
567 siginfo.si_code = TRAP_HWBKPT;
568 #ifdef CONFIG_ITANIUM
569 /*
570 * Erratum 10 (IFA may contain incorrect address) now has
571 * "NoFix" status. There are no plans for fixing this.
572 */
573 if (ia64_psr(&regs)->is == 0)
574 ifa = regs.cr_iip;
575 #endif
576 break;
577 case 35: siginfo.si_code = TRAP_BRANCH; ifa = 0; break;
578 case 36: siginfo.si_code = TRAP_TRACE; ifa = 0; break;
579 }
580 if (notify_die(DIE_FAULT, "ia64_fault", &regs, vector, siginfo.si_code, SIGTRAP)
581 == NOTIFY_STOP)
582 return;
583 siginfo.si_signo = SIGTRAP;
584 siginfo.si_errno = 0;
585 siginfo.si_addr = (void __user *) ifa;
586 siginfo.si_imm = 0;
587 siginfo.si_flags = __ISR_VALID;
588 siginfo.si_isr = isr;
589 force_sig_info(SIGTRAP, &siginfo, current);
590 return;
591
592 case 32: /* fp fault */
593 case 33: /* fp trap */
594 result = handle_fpu_swa((vector == 32) ? 1 : 0, &regs, isr);
595 if ((result < 0) || (current->thread.flags & IA64_THREAD_FPEMU_SIGFPE)) {
596 siginfo.si_signo = SIGFPE;
597 siginfo.si_errno = 0;
598 siginfo.si_code = FPE_FLTINV;
599 siginfo.si_addr = (void __user *) iip;
600 siginfo.si_flags = __ISR_VALID;
601 siginfo.si_isr = isr;
602 siginfo.si_imm = 0;
603 force_sig_info(SIGFPE, &siginfo, current);
604 }
605 return;
606
607 case 34:
608 if (isr & 0x2) {
609 /* Lower-Privilege Transfer Trap */
610 /*
611 * Just clear PSR.lp and then return immediately: all the
612 * interesting work (e.g., signal delivery is done in the kernel
613 * exit path).
614 */
615 ia64_psr(&regs)->lp = 0;
616 return;
617 } else {
618 /* Unimplemented Instr. Address Trap */
619 if (user_mode(&regs)) {
620 siginfo.si_signo = SIGILL;
621 siginfo.si_code = ILL_BADIADDR;
622 siginfo.si_errno = 0;
623 siginfo.si_flags = 0;
624 siginfo.si_isr = 0;
625 siginfo.si_imm = 0;
626 siginfo.si_addr = (void __user *) iip;
627 force_sig_info(SIGILL, &siginfo, current);
628 return;
629 }
630 sprintf(buf, "Unimplemented Instruction Address fault");
631 }
632 break;
633
634 case 45:
635 #ifdef CONFIG_IA32_SUPPORT
636 if (ia32_exception(&regs, isr) == 0)
637 return;
638 #endif
639 printk(KERN_ERR "Unexpected IA-32 exception (Trap 45)\n");
640 printk(KERN_ERR " iip - 0x%lx, ifa - 0x%lx, isr - 0x%lx\n",
641 iip, ifa, isr);
642 force_sig(SIGSEGV, current);
643 break;
644
645 case 46:
646 #ifdef CONFIG_IA32_SUPPORT
647 if (ia32_intercept(&regs, isr) == 0)
648 return;
649 #endif
650 printk(KERN_ERR "Unexpected IA-32 intercept trap (Trap 46)\n");
651 printk(KERN_ERR " iip - 0x%lx, ifa - 0x%lx, isr - 0x%lx, iim - 0x%lx\n",
652 iip, ifa, isr, iim);
653 force_sig(SIGSEGV, current);
654 return;
655
656 case 47:
657 sprintf(buf, "IA-32 Interruption Fault (int 0x%lx)", isr >> 16);
658 break;
659
660 default:
661 sprintf(buf, "Fault %lu", vector);
662 break;
663 }
664 die_if_kernel(buf, &regs, error);
665 force_sig(SIGILL, current);
666 }
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