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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * 'traps.c' handles hardware traps and faults after we have saved some
4 * state in 'entry.S'.
5 *
6 * SuperH version: Copyright (C) 1999 Niibe Yutaka
7 * Copyright (C) 2000 Philipp Rumpf
8 * Copyright (C) 2000 David Howells
9 * Copyright (C) 2002 - 2010 Paul Mundt
10 */
11#include <linux/kernel.h>
12#include <linux/ptrace.h>
13#include <linux/hardirq.h>
14#include <linux/init.h>
15#include <linux/spinlock.h>
16#include <linux/kallsyms.h>
17#include <linux/io.h>
18#include <linux/bug.h>
19#include <linux/debug_locks.h>
20#include <linux/kdebug.h>
21#include <linux/limits.h>
22#include <linux/sysfs.h>
23#include <linux/uaccess.h>
24#include <linux/perf_event.h>
25#include <linux/sched/task_stack.h>
26
27#include <asm/alignment.h>
28#include <asm/fpu.h>
29#include <asm/kprobes.h>
30#include <asm/traps.h>
31#include <asm/bl_bit.h>
32
33#ifdef CONFIG_CPU_SH2
34# define TRAP_RESERVED_INST 4
35# define TRAP_ILLEGAL_SLOT_INST 6
36# define TRAP_ADDRESS_ERROR 9
37# ifdef CONFIG_CPU_SH2A
38# define TRAP_UBC 12
39# define TRAP_FPU_ERROR 13
40# define TRAP_DIVZERO_ERROR 17
41# define TRAP_DIVOVF_ERROR 18
42# endif
43#else
44#define TRAP_RESERVED_INST 12
45#define TRAP_ILLEGAL_SLOT_INST 13
46#endif
47
48static inline void sign_extend(unsigned int count, unsigned char *dst)
49{
50#ifdef __LITTLE_ENDIAN__
51 if ((count == 1) && dst[0] & 0x80) {
52 dst[1] = 0xff;
53 dst[2] = 0xff;
54 dst[3] = 0xff;
55 }
56 if ((count == 2) && dst[1] & 0x80) {
57 dst[2] = 0xff;
58 dst[3] = 0xff;
59 }
60#else
61 if ((count == 1) && dst[3] & 0x80) {
62 dst[2] = 0xff;
63 dst[1] = 0xff;
64 dst[0] = 0xff;
65 }
66 if ((count == 2) && dst[2] & 0x80) {
67 dst[1] = 0xff;
68 dst[0] = 0xff;
69 }
70#endif
71}
72
73static struct mem_access user_mem_access = {
74 copy_from_user,
75 copy_to_user,
76};
77
78static unsigned long copy_from_kernel_wrapper(void *dst, const void __user *src,
79 unsigned long cnt)
80{
81 return copy_from_kernel_nofault(dst, (const void __force *)src, cnt);
82}
83
84static unsigned long copy_to_kernel_wrapper(void __user *dst, const void *src,
85 unsigned long cnt)
86{
87 return copy_to_kernel_nofault((void __force *)dst, src, cnt);
88}
89
90static struct mem_access kernel_mem_access = {
91 copy_from_kernel_wrapper,
92 copy_to_kernel_wrapper,
93};
94
95/*
96 * handle an instruction that does an unaligned memory access by emulating the
97 * desired behaviour
98 * - note that PC _may not_ point to the faulting instruction
99 * (if that instruction is in a branch delay slot)
100 * - return 0 if emulation okay, -EFAULT on existential error
101 */
102static int handle_unaligned_ins(insn_size_t instruction, struct pt_regs *regs,
103 struct mem_access *ma)
104{
105 int ret, index, count;
106 unsigned long *rm, *rn;
107 unsigned char *src, *dst;
108 unsigned char __user *srcu, *dstu;
109
110 index = (instruction>>8)&15; /* 0x0F00 */
111 rn = ®s->regs[index];
112
113 index = (instruction>>4)&15; /* 0x00F0 */
114 rm = ®s->regs[index];
115
116 count = 1<<(instruction&3);
117
118 switch (count) {
119 case 1: inc_unaligned_byte_access(); break;
120 case 2: inc_unaligned_word_access(); break;
121 case 4: inc_unaligned_dword_access(); break;
122 case 8: inc_unaligned_multi_access(); break;
123 }
124
125 ret = -EFAULT;
126 switch (instruction>>12) {
127 case 0: /* mov.[bwl] to/from memory via r0+rn */
128 if (instruction & 8) {
129 /* from memory */
130 srcu = (unsigned char __user *)*rm;
131 srcu += regs->regs[0];
132 dst = (unsigned char *)rn;
133 *(unsigned long *)dst = 0;
134
135#if !defined(__LITTLE_ENDIAN__)
136 dst += 4-count;
137#endif
138 if (ma->from(dst, srcu, count))
139 goto fetch_fault;
140
141 sign_extend(count, dst);
142 } else {
143 /* to memory */
144 src = (unsigned char *)rm;
145#if !defined(__LITTLE_ENDIAN__)
146 src += 4-count;
147#endif
148 dstu = (unsigned char __user *)*rn;
149 dstu += regs->regs[0];
150
151 if (ma->to(dstu, src, count))
152 goto fetch_fault;
153 }
154 ret = 0;
155 break;
156
157 case 1: /* mov.l Rm,@(disp,Rn) */
158 src = (unsigned char*) rm;
159 dstu = (unsigned char __user *)*rn;
160 dstu += (instruction&0x000F)<<2;
161
162 if (ma->to(dstu, src, 4))
163 goto fetch_fault;
164 ret = 0;
165 break;
166
167 case 2: /* mov.[bwl] to memory, possibly with pre-decrement */
168 if (instruction & 4)
169 *rn -= count;
170 src = (unsigned char*) rm;
171 dstu = (unsigned char __user *)*rn;
172#if !defined(__LITTLE_ENDIAN__)
173 src += 4-count;
174#endif
175 if (ma->to(dstu, src, count))
176 goto fetch_fault;
177 ret = 0;
178 break;
179
180 case 5: /* mov.l @(disp,Rm),Rn */
181 srcu = (unsigned char __user *)*rm;
182 srcu += (instruction & 0x000F) << 2;
183 dst = (unsigned char *)rn;
184 *(unsigned long *)dst = 0;
185
186 if (ma->from(dst, srcu, 4))
187 goto fetch_fault;
188 ret = 0;
189 break;
190
191 case 6: /* mov.[bwl] from memory, possibly with post-increment */
192 srcu = (unsigned char __user *)*rm;
193 if (instruction & 4)
194 *rm += count;
195 dst = (unsigned char*) rn;
196 *(unsigned long*)dst = 0;
197
198#if !defined(__LITTLE_ENDIAN__)
199 dst += 4-count;
200#endif
201 if (ma->from(dst, srcu, count))
202 goto fetch_fault;
203 sign_extend(count, dst);
204 ret = 0;
205 break;
206
207 case 8:
208 switch ((instruction&0xFF00)>>8) {
209 case 0x81: /* mov.w R0,@(disp,Rn) */
210 src = (unsigned char *) ®s->regs[0];
211#if !defined(__LITTLE_ENDIAN__)
212 src += 2;
213#endif
214 dstu = (unsigned char __user *)*rm; /* called Rn in the spec */
215 dstu += (instruction & 0x000F) << 1;
216
217 if (ma->to(dstu, src, 2))
218 goto fetch_fault;
219 ret = 0;
220 break;
221
222 case 0x85: /* mov.w @(disp,Rm),R0 */
223 srcu = (unsigned char __user *)*rm;
224 srcu += (instruction & 0x000F) << 1;
225 dst = (unsigned char *) ®s->regs[0];
226 *(unsigned long *)dst = 0;
227
228#if !defined(__LITTLE_ENDIAN__)
229 dst += 2;
230#endif
231 if (ma->from(dst, srcu, 2))
232 goto fetch_fault;
233 sign_extend(2, dst);
234 ret = 0;
235 break;
236 }
237 break;
238
239 case 9: /* mov.w @(disp,PC),Rn */
240 srcu = (unsigned char __user *)regs->pc;
241 srcu += 4;
242 srcu += (instruction & 0x00FF) << 1;
243 dst = (unsigned char *)rn;
244 *(unsigned long *)dst = 0;
245
246#if !defined(__LITTLE_ENDIAN__)
247 dst += 2;
248#endif
249
250 if (ma->from(dst, srcu, 2))
251 goto fetch_fault;
252 sign_extend(2, dst);
253 ret = 0;
254 break;
255
256 case 0xd: /* mov.l @(disp,PC),Rn */
257 srcu = (unsigned char __user *)(regs->pc & ~0x3);
258 srcu += 4;
259 srcu += (instruction & 0x00FF) << 2;
260 dst = (unsigned char *)rn;
261 *(unsigned long *)dst = 0;
262
263 if (ma->from(dst, srcu, 4))
264 goto fetch_fault;
265 ret = 0;
266 break;
267 }
268 return ret;
269
270 fetch_fault:
271 /* Argh. Address not only misaligned but also non-existent.
272 * Raise an EFAULT and see if it's trapped
273 */
274 die_if_no_fixup("Fault in unaligned fixup", regs, 0);
275 return -EFAULT;
276}
277
278/*
279 * emulate the instruction in the delay slot
280 * - fetches the instruction from PC+2
281 */
282static inline int handle_delayslot(struct pt_regs *regs,
283 insn_size_t old_instruction,
284 struct mem_access *ma)
285{
286 insn_size_t instruction;
287 void __user *addr = (void __user *)(regs->pc +
288 instruction_size(old_instruction));
289
290 if (copy_from_user(&instruction, addr, sizeof(instruction))) {
291 /* the instruction-fetch faulted */
292 if (user_mode(regs))
293 return -EFAULT;
294
295 /* kernel */
296 die("delay-slot-insn faulting in handle_unaligned_delayslot",
297 regs, 0);
298 }
299
300 return handle_unaligned_ins(instruction, regs, ma);
301}
302
303/*
304 * handle an instruction that does an unaligned memory access
305 * - have to be careful of branch delay-slot instructions that fault
306 * SH3:
307 * - if the branch would be taken PC points to the branch
308 * - if the branch would not be taken, PC points to delay-slot
309 * SH4:
310 * - PC always points to delayed branch
311 * - return 0 if handled, -EFAULT if failed (may not return if in kernel)
312 */
313
314/* Macros to determine offset from current PC for branch instructions */
315/* Explicit type coercion is used to force sign extension where needed */
316#define SH_PC_8BIT_OFFSET(instr) ((((signed char)(instr))*2) + 4)
317#define SH_PC_12BIT_OFFSET(instr) ((((signed short)(instr<<4))>>3) + 4)
318
319int handle_unaligned_access(insn_size_t instruction, struct pt_regs *regs,
320 struct mem_access *ma, int expected,
321 unsigned long address)
322{
323 u_int rm;
324 int ret, index;
325
326 /*
327 * XXX: We can't handle mixed 16/32-bit instructions yet
328 */
329 if (instruction_size(instruction) != 2)
330 return -EINVAL;
331
332 index = (instruction>>8)&15; /* 0x0F00 */
333 rm = regs->regs[index];
334
335 /*
336 * Log the unexpected fixups, and then pass them on to perf.
337 *
338 * We intentionally don't report the expected cases to perf as
339 * otherwise the trapped I/O case will skew the results too much
340 * to be useful.
341 */
342 if (!expected) {
343 unaligned_fixups_notify(current, instruction, regs);
344 perf_sw_event(PERF_COUNT_SW_ALIGNMENT_FAULTS, 1,
345 regs, address);
346 }
347
348 ret = -EFAULT;
349 switch (instruction&0xF000) {
350 case 0x0000:
351 if (instruction==0x000B) {
352 /* rts */
353 ret = handle_delayslot(regs, instruction, ma);
354 if (ret==0)
355 regs->pc = regs->pr;
356 }
357 else if ((instruction&0x00FF)==0x0023) {
358 /* braf @Rm */
359 ret = handle_delayslot(regs, instruction, ma);
360 if (ret==0)
361 regs->pc += rm + 4;
362 }
363 else if ((instruction&0x00FF)==0x0003) {
364 /* bsrf @Rm */
365 ret = handle_delayslot(regs, instruction, ma);
366 if (ret==0) {
367 regs->pr = regs->pc + 4;
368 regs->pc += rm + 4;
369 }
370 }
371 else {
372 /* mov.[bwl] to/from memory via r0+rn */
373 goto simple;
374 }
375 break;
376
377 case 0x1000: /* mov.l Rm,@(disp,Rn) */
378 goto simple;
379
380 case 0x2000: /* mov.[bwl] to memory, possibly with pre-decrement */
381 goto simple;
382
383 case 0x4000:
384 if ((instruction&0x00FF)==0x002B) {
385 /* jmp @Rm */
386 ret = handle_delayslot(regs, instruction, ma);
387 if (ret==0)
388 regs->pc = rm;
389 }
390 else if ((instruction&0x00FF)==0x000B) {
391 /* jsr @Rm */
392 ret = handle_delayslot(regs, instruction, ma);
393 if (ret==0) {
394 regs->pr = regs->pc + 4;
395 regs->pc = rm;
396 }
397 }
398 else {
399 /* mov.[bwl] to/from memory via r0+rn */
400 goto simple;
401 }
402 break;
403
404 case 0x5000: /* mov.l @(disp,Rm),Rn */
405 goto simple;
406
407 case 0x6000: /* mov.[bwl] from memory, possibly with post-increment */
408 goto simple;
409
410 case 0x8000: /* bf lab, bf/s lab, bt lab, bt/s lab */
411 switch (instruction&0x0F00) {
412 case 0x0100: /* mov.w R0,@(disp,Rm) */
413 goto simple;
414 case 0x0500: /* mov.w @(disp,Rm),R0 */
415 goto simple;
416 case 0x0B00: /* bf lab - no delayslot*/
417 ret = 0;
418 break;
419 case 0x0F00: /* bf/s lab */
420 ret = handle_delayslot(regs, instruction, ma);
421 if (ret==0) {
422#if defined(CONFIG_CPU_SH4) || defined(CONFIG_SH7705_CACHE_32KB)
423 if ((regs->sr & 0x00000001) != 0)
424 regs->pc += 4; /* next after slot */
425 else
426#endif
427 regs->pc += SH_PC_8BIT_OFFSET(instruction);
428 }
429 break;
430 case 0x0900: /* bt lab - no delayslot */
431 ret = 0;
432 break;
433 case 0x0D00: /* bt/s lab */
434 ret = handle_delayslot(regs, instruction, ma);
435 if (ret==0) {
436#if defined(CONFIG_CPU_SH4) || defined(CONFIG_SH7705_CACHE_32KB)
437 if ((regs->sr & 0x00000001) == 0)
438 regs->pc += 4; /* next after slot */
439 else
440#endif
441 regs->pc += SH_PC_8BIT_OFFSET(instruction);
442 }
443 break;
444 }
445 break;
446
447 case 0x9000: /* mov.w @(disp,Rm),Rn */
448 goto simple;
449
450 case 0xA000: /* bra label */
451 ret = handle_delayslot(regs, instruction, ma);
452 if (ret==0)
453 regs->pc += SH_PC_12BIT_OFFSET(instruction);
454 break;
455
456 case 0xB000: /* bsr label */
457 ret = handle_delayslot(regs, instruction, ma);
458 if (ret==0) {
459 regs->pr = regs->pc + 4;
460 regs->pc += SH_PC_12BIT_OFFSET(instruction);
461 }
462 break;
463
464 case 0xD000: /* mov.l @(disp,Rm),Rn */
465 goto simple;
466 }
467 return ret;
468
469 /* handle non-delay-slot instruction */
470 simple:
471 ret = handle_unaligned_ins(instruction, regs, ma);
472 if (ret==0)
473 regs->pc += instruction_size(instruction);
474 return ret;
475}
476
477/*
478 * Handle various address error exceptions:
479 * - instruction address error:
480 * misaligned PC
481 * PC >= 0x80000000 in user mode
482 * - data address error (read and write)
483 * misaligned data access
484 * access to >= 0x80000000 is user mode
485 * Unfortuntaly we can't distinguish between instruction address error
486 * and data address errors caused by read accesses.
487 */
488asmlinkage void do_address_error(struct pt_regs *regs,
489 unsigned long writeaccess,
490 unsigned long address)
491{
492 unsigned long error_code = 0;
493 insn_size_t instruction;
494 int tmp;
495
496 /* Intentional ifdef */
497#ifdef CONFIG_CPU_HAS_SR_RB
498 error_code = lookup_exception_vector();
499#endif
500
501 if (user_mode(regs)) {
502 int si_code = BUS_ADRERR;
503 unsigned int user_action;
504
505 local_irq_enable();
506 inc_unaligned_user_access();
507
508 if (copy_from_user(&instruction, (insn_size_t __user *)(regs->pc & ~1),
509 sizeof(instruction))) {
510 goto uspace_segv;
511 }
512
513 /* shout about userspace fixups */
514 unaligned_fixups_notify(current, instruction, regs);
515
516 user_action = unaligned_user_action();
517 if (user_action & UM_FIXUP)
518 goto fixup;
519 if (user_action & UM_SIGNAL)
520 goto uspace_segv;
521 else {
522 /* ignore */
523 regs->pc += instruction_size(instruction);
524 return;
525 }
526
527fixup:
528 /* bad PC is not something we can fix */
529 if (regs->pc & 1) {
530 si_code = BUS_ADRALN;
531 goto uspace_segv;
532 }
533
534 tmp = handle_unaligned_access(instruction, regs,
535 &user_mem_access, 0,
536 address);
537
538 if (tmp == 0)
539 return; /* sorted */
540uspace_segv:
541 printk(KERN_NOTICE "Sending SIGBUS to \"%s\" due to unaligned "
542 "access (PC %lx PR %lx)\n", current->comm, regs->pc,
543 regs->pr);
544
545 force_sig_fault(SIGBUS, si_code, (void __user *)address);
546 } else {
547 inc_unaligned_kernel_access();
548
549 if (regs->pc & 1)
550 die("unaligned program counter", regs, error_code);
551
552 if (copy_from_kernel_nofault(&instruction, (void *)(regs->pc),
553 sizeof(instruction))) {
554 /* Argh. Fault on the instruction itself.
555 This should never happen non-SMP
556 */
557 die("insn faulting in do_address_error", regs, 0);
558 }
559
560 unaligned_fixups_notify(current, instruction, regs);
561
562 handle_unaligned_access(instruction, regs, &kernel_mem_access,
563 0, address);
564 }
565}
566
567#ifdef CONFIG_SH_DSP
568/*
569 * SH-DSP support gerg@snapgear.com.
570 */
571int is_dsp_inst(struct pt_regs *regs)
572{
573 unsigned short inst = 0;
574
575 /*
576 * Safe guard if DSP mode is already enabled or we're lacking
577 * the DSP altogether.
578 */
579 if (!(current_cpu_data.flags & CPU_HAS_DSP) || (regs->sr & SR_DSP))
580 return 0;
581
582 get_user(inst, ((unsigned short *) regs->pc));
583
584 inst &= 0xf000;
585
586 /* Check for any type of DSP or support instruction */
587 if ((inst == 0xf000) || (inst == 0x4000))
588 return 1;
589
590 return 0;
591}
592#else
593#define is_dsp_inst(regs) (0)
594#endif /* CONFIG_SH_DSP */
595
596#ifdef CONFIG_CPU_SH2A
597asmlinkage void do_divide_error(unsigned long r4)
598{
599 int code;
600
601 switch (r4) {
602 case TRAP_DIVZERO_ERROR:
603 code = FPE_INTDIV;
604 break;
605 case TRAP_DIVOVF_ERROR:
606 code = FPE_INTOVF;
607 break;
608 default:
609 /* Let gcc know unhandled cases don't make it past here */
610 return;
611 }
612 force_sig_fault(SIGFPE, code, NULL);
613}
614#endif
615
616asmlinkage void do_reserved_inst(void)
617{
618 struct pt_regs *regs = current_pt_regs();
619 unsigned long error_code;
620
621#ifdef CONFIG_SH_FPU_EMU
622 unsigned short inst = 0;
623 int err;
624
625 get_user(inst, (unsigned short __user *)regs->pc);
626
627 err = do_fpu_inst(inst, regs);
628 if (!err) {
629 regs->pc += instruction_size(inst);
630 return;
631 }
632 /* not a FPU inst. */
633#endif
634
635#ifdef CONFIG_SH_DSP
636 /* Check if it's a DSP instruction */
637 if (is_dsp_inst(regs)) {
638 /* Enable DSP mode, and restart instruction. */
639 regs->sr |= SR_DSP;
640 /* Save DSP mode */
641 current->thread.dsp_status.status |= SR_DSP;
642 return;
643 }
644#endif
645
646 error_code = lookup_exception_vector();
647
648 local_irq_enable();
649 force_sig(SIGILL);
650 die_if_no_fixup("reserved instruction", regs, error_code);
651}
652
653#ifdef CONFIG_SH_FPU_EMU
654static int emulate_branch(unsigned short inst, struct pt_regs *regs)
655{
656 /*
657 * bfs: 8fxx: PC+=d*2+4;
658 * bts: 8dxx: PC+=d*2+4;
659 * bra: axxx: PC+=D*2+4;
660 * bsr: bxxx: PC+=D*2+4 after PR=PC+4;
661 * braf:0x23: PC+=Rn*2+4;
662 * bsrf:0x03: PC+=Rn*2+4 after PR=PC+4;
663 * jmp: 4x2b: PC=Rn;
664 * jsr: 4x0b: PC=Rn after PR=PC+4;
665 * rts: 000b: PC=PR;
666 */
667 if (((inst & 0xf000) == 0xb000) || /* bsr */
668 ((inst & 0xf0ff) == 0x0003) || /* bsrf */
669 ((inst & 0xf0ff) == 0x400b)) /* jsr */
670 regs->pr = regs->pc + 4;
671
672 if ((inst & 0xfd00) == 0x8d00) { /* bfs, bts */
673 regs->pc += SH_PC_8BIT_OFFSET(inst);
674 return 0;
675 }
676
677 if ((inst & 0xe000) == 0xa000) { /* bra, bsr */
678 regs->pc += SH_PC_12BIT_OFFSET(inst);
679 return 0;
680 }
681
682 if ((inst & 0xf0df) == 0x0003) { /* braf, bsrf */
683 regs->pc += regs->regs[(inst & 0x0f00) >> 8] + 4;
684 return 0;
685 }
686
687 if ((inst & 0xf0df) == 0x400b) { /* jmp, jsr */
688 regs->pc = regs->regs[(inst & 0x0f00) >> 8];
689 return 0;
690 }
691
692 if ((inst & 0xffff) == 0x000b) { /* rts */
693 regs->pc = regs->pr;
694 return 0;
695 }
696
697 return 1;
698}
699#endif
700
701asmlinkage void do_illegal_slot_inst(void)
702{
703 struct pt_regs *regs = current_pt_regs();
704 unsigned long inst;
705
706 if (kprobe_handle_illslot(regs->pc) == 0)
707 return;
708
709#ifdef CONFIG_SH_FPU_EMU
710 get_user(inst, (unsigned short __user *)regs->pc + 1);
711 if (!do_fpu_inst(inst, regs)) {
712 get_user(inst, (unsigned short __user *)regs->pc);
713 if (!emulate_branch(inst, regs))
714 return;
715 /* fault in branch.*/
716 }
717 /* not a FPU inst. */
718#endif
719
720 inst = lookup_exception_vector();
721
722 local_irq_enable();
723 force_sig(SIGILL);
724 die_if_no_fixup("illegal slot instruction", regs, inst);
725}
726
727asmlinkage void do_exception_error(void)
728{
729 long ex;
730
731 ex = lookup_exception_vector();
732 die_if_kernel("exception", current_pt_regs(), ex);
733}
734
735void per_cpu_trap_init(void)
736{
737 extern void *vbr_base;
738
739 /* NOTE: The VBR value should be at P1
740 (or P2, virtural "fixed" address space).
741 It's definitely should not in physical address. */
742
743 asm volatile("ldc %0, vbr"
744 : /* no output */
745 : "r" (&vbr_base)
746 : "memory");
747
748 /* disable exception blocking now when the vbr has been setup */
749 clear_bl_bit();
750}
751
752void *set_exception_table_vec(unsigned int vec, void *handler)
753{
754 extern void *exception_handling_table[];
755 void *old_handler;
756
757 old_handler = exception_handling_table[vec];
758 exception_handling_table[vec] = handler;
759 return old_handler;
760}
761
762void __init trap_init(void)
763{
764 set_exception_table_vec(TRAP_RESERVED_INST, do_reserved_inst);
765 set_exception_table_vec(TRAP_ILLEGAL_SLOT_INST, do_illegal_slot_inst);
766
767#if defined(CONFIG_CPU_SH4) && !defined(CONFIG_SH_FPU) || \
768 defined(CONFIG_SH_FPU_EMU)
769 /*
770 * For SH-4 lacking an FPU, treat floating point instructions as
771 * reserved. They'll be handled in the math-emu case, or faulted on
772 * otherwise.
773 */
774 set_exception_table_evt(0x800, do_reserved_inst);
775 set_exception_table_evt(0x820, do_illegal_slot_inst);
776#elif defined(CONFIG_SH_FPU)
777 set_exception_table_evt(0x800, fpu_state_restore_trap_handler);
778 set_exception_table_evt(0x820, fpu_state_restore_trap_handler);
779#endif
780
781#ifdef CONFIG_CPU_SH2
782 set_exception_table_vec(TRAP_ADDRESS_ERROR, address_error_trap_handler);
783#endif
784#ifdef CONFIG_CPU_SH2A
785 set_exception_table_vec(TRAP_DIVZERO_ERROR, do_divide_error);
786 set_exception_table_vec(TRAP_DIVOVF_ERROR, do_divide_error);
787#ifdef CONFIG_SH_FPU
788 set_exception_table_vec(TRAP_FPU_ERROR, fpu_error_trap_handler);
789#endif
790#endif
791
792#ifdef TRAP_UBC
793 set_exception_table_vec(TRAP_UBC, breakpoint_trap_handler);
794#endif
795}
1/*
2 * 'traps.c' handles hardware traps and faults after we have saved some
3 * state in 'entry.S'.
4 *
5 * SuperH version: Copyright (C) 1999 Niibe Yutaka
6 * Copyright (C) 2000 Philipp Rumpf
7 * Copyright (C) 2000 David Howells
8 * Copyright (C) 2002 - 2010 Paul Mundt
9 *
10 * This file is subject to the terms and conditions of the GNU General Public
11 * License. See the file "COPYING" in the main directory of this archive
12 * for more details.
13 */
14#include <linux/kernel.h>
15#include <linux/ptrace.h>
16#include <linux/hardirq.h>
17#include <linux/init.h>
18#include <linux/spinlock.h>
19#include <linux/kallsyms.h>
20#include <linux/io.h>
21#include <linux/bug.h>
22#include <linux/debug_locks.h>
23#include <linux/kdebug.h>
24#include <linux/limits.h>
25#include <linux/sysfs.h>
26#include <linux/uaccess.h>
27#include <linux/perf_event.h>
28#include <linux/sched/task_stack.h>
29
30#include <asm/alignment.h>
31#include <asm/fpu.h>
32#include <asm/kprobes.h>
33#include <asm/traps.h>
34#include <asm/bl_bit.h>
35
36#ifdef CONFIG_CPU_SH2
37# define TRAP_RESERVED_INST 4
38# define TRAP_ILLEGAL_SLOT_INST 6
39# define TRAP_ADDRESS_ERROR 9
40# ifdef CONFIG_CPU_SH2A
41# define TRAP_UBC 12
42# define TRAP_FPU_ERROR 13
43# define TRAP_DIVZERO_ERROR 17
44# define TRAP_DIVOVF_ERROR 18
45# endif
46#else
47#define TRAP_RESERVED_INST 12
48#define TRAP_ILLEGAL_SLOT_INST 13
49#endif
50
51static inline void sign_extend(unsigned int count, unsigned char *dst)
52{
53#ifdef __LITTLE_ENDIAN__
54 if ((count == 1) && dst[0] & 0x80) {
55 dst[1] = 0xff;
56 dst[2] = 0xff;
57 dst[3] = 0xff;
58 }
59 if ((count == 2) && dst[1] & 0x80) {
60 dst[2] = 0xff;
61 dst[3] = 0xff;
62 }
63#else
64 if ((count == 1) && dst[3] & 0x80) {
65 dst[2] = 0xff;
66 dst[1] = 0xff;
67 dst[0] = 0xff;
68 }
69 if ((count == 2) && dst[2] & 0x80) {
70 dst[1] = 0xff;
71 dst[0] = 0xff;
72 }
73#endif
74}
75
76static struct mem_access user_mem_access = {
77 copy_from_user,
78 copy_to_user,
79};
80
81/*
82 * handle an instruction that does an unaligned memory access by emulating the
83 * desired behaviour
84 * - note that PC _may not_ point to the faulting instruction
85 * (if that instruction is in a branch delay slot)
86 * - return 0 if emulation okay, -EFAULT on existential error
87 */
88static int handle_unaligned_ins(insn_size_t instruction, struct pt_regs *regs,
89 struct mem_access *ma)
90{
91 int ret, index, count;
92 unsigned long *rm, *rn;
93 unsigned char *src, *dst;
94 unsigned char __user *srcu, *dstu;
95
96 index = (instruction>>8)&15; /* 0x0F00 */
97 rn = ®s->regs[index];
98
99 index = (instruction>>4)&15; /* 0x00F0 */
100 rm = ®s->regs[index];
101
102 count = 1<<(instruction&3);
103
104 switch (count) {
105 case 1: inc_unaligned_byte_access(); break;
106 case 2: inc_unaligned_word_access(); break;
107 case 4: inc_unaligned_dword_access(); break;
108 case 8: inc_unaligned_multi_access(); break;
109 }
110
111 ret = -EFAULT;
112 switch (instruction>>12) {
113 case 0: /* mov.[bwl] to/from memory via r0+rn */
114 if (instruction & 8) {
115 /* from memory */
116 srcu = (unsigned char __user *)*rm;
117 srcu += regs->regs[0];
118 dst = (unsigned char *)rn;
119 *(unsigned long *)dst = 0;
120
121#if !defined(__LITTLE_ENDIAN__)
122 dst += 4-count;
123#endif
124 if (ma->from(dst, srcu, count))
125 goto fetch_fault;
126
127 sign_extend(count, dst);
128 } else {
129 /* to memory */
130 src = (unsigned char *)rm;
131#if !defined(__LITTLE_ENDIAN__)
132 src += 4-count;
133#endif
134 dstu = (unsigned char __user *)*rn;
135 dstu += regs->regs[0];
136
137 if (ma->to(dstu, src, count))
138 goto fetch_fault;
139 }
140 ret = 0;
141 break;
142
143 case 1: /* mov.l Rm,@(disp,Rn) */
144 src = (unsigned char*) rm;
145 dstu = (unsigned char __user *)*rn;
146 dstu += (instruction&0x000F)<<2;
147
148 if (ma->to(dstu, src, 4))
149 goto fetch_fault;
150 ret = 0;
151 break;
152
153 case 2: /* mov.[bwl] to memory, possibly with pre-decrement */
154 if (instruction & 4)
155 *rn -= count;
156 src = (unsigned char*) rm;
157 dstu = (unsigned char __user *)*rn;
158#if !defined(__LITTLE_ENDIAN__)
159 src += 4-count;
160#endif
161 if (ma->to(dstu, src, count))
162 goto fetch_fault;
163 ret = 0;
164 break;
165
166 case 5: /* mov.l @(disp,Rm),Rn */
167 srcu = (unsigned char __user *)*rm;
168 srcu += (instruction & 0x000F) << 2;
169 dst = (unsigned char *)rn;
170 *(unsigned long *)dst = 0;
171
172 if (ma->from(dst, srcu, 4))
173 goto fetch_fault;
174 ret = 0;
175 break;
176
177 case 6: /* mov.[bwl] from memory, possibly with post-increment */
178 srcu = (unsigned char __user *)*rm;
179 if (instruction & 4)
180 *rm += count;
181 dst = (unsigned char*) rn;
182 *(unsigned long*)dst = 0;
183
184#if !defined(__LITTLE_ENDIAN__)
185 dst += 4-count;
186#endif
187 if (ma->from(dst, srcu, count))
188 goto fetch_fault;
189 sign_extend(count, dst);
190 ret = 0;
191 break;
192
193 case 8:
194 switch ((instruction&0xFF00)>>8) {
195 case 0x81: /* mov.w R0,@(disp,Rn) */
196 src = (unsigned char *) ®s->regs[0];
197#if !defined(__LITTLE_ENDIAN__)
198 src += 2;
199#endif
200 dstu = (unsigned char __user *)*rm; /* called Rn in the spec */
201 dstu += (instruction & 0x000F) << 1;
202
203 if (ma->to(dstu, src, 2))
204 goto fetch_fault;
205 ret = 0;
206 break;
207
208 case 0x85: /* mov.w @(disp,Rm),R0 */
209 srcu = (unsigned char __user *)*rm;
210 srcu += (instruction & 0x000F) << 1;
211 dst = (unsigned char *) ®s->regs[0];
212 *(unsigned long *)dst = 0;
213
214#if !defined(__LITTLE_ENDIAN__)
215 dst += 2;
216#endif
217 if (ma->from(dst, srcu, 2))
218 goto fetch_fault;
219 sign_extend(2, dst);
220 ret = 0;
221 break;
222 }
223 break;
224
225 case 9: /* mov.w @(disp,PC),Rn */
226 srcu = (unsigned char __user *)regs->pc;
227 srcu += 4;
228 srcu += (instruction & 0x00FF) << 1;
229 dst = (unsigned char *)rn;
230 *(unsigned long *)dst = 0;
231
232#if !defined(__LITTLE_ENDIAN__)
233 dst += 2;
234#endif
235
236 if (ma->from(dst, srcu, 2))
237 goto fetch_fault;
238 sign_extend(2, dst);
239 ret = 0;
240 break;
241
242 case 0xd: /* mov.l @(disp,PC),Rn */
243 srcu = (unsigned char __user *)(regs->pc & ~0x3);
244 srcu += 4;
245 srcu += (instruction & 0x00FF) << 2;
246 dst = (unsigned char *)rn;
247 *(unsigned long *)dst = 0;
248
249 if (ma->from(dst, srcu, 4))
250 goto fetch_fault;
251 ret = 0;
252 break;
253 }
254 return ret;
255
256 fetch_fault:
257 /* Argh. Address not only misaligned but also non-existent.
258 * Raise an EFAULT and see if it's trapped
259 */
260 die_if_no_fixup("Fault in unaligned fixup", regs, 0);
261 return -EFAULT;
262}
263
264/*
265 * emulate the instruction in the delay slot
266 * - fetches the instruction from PC+2
267 */
268static inline int handle_delayslot(struct pt_regs *regs,
269 insn_size_t old_instruction,
270 struct mem_access *ma)
271{
272 insn_size_t instruction;
273 void __user *addr = (void __user *)(regs->pc +
274 instruction_size(old_instruction));
275
276 if (copy_from_user(&instruction, addr, sizeof(instruction))) {
277 /* the instruction-fetch faulted */
278 if (user_mode(regs))
279 return -EFAULT;
280
281 /* kernel */
282 die("delay-slot-insn faulting in handle_unaligned_delayslot",
283 regs, 0);
284 }
285
286 return handle_unaligned_ins(instruction, regs, ma);
287}
288
289/*
290 * handle an instruction that does an unaligned memory access
291 * - have to be careful of branch delay-slot instructions that fault
292 * SH3:
293 * - if the branch would be taken PC points to the branch
294 * - if the branch would not be taken, PC points to delay-slot
295 * SH4:
296 * - PC always points to delayed branch
297 * - return 0 if handled, -EFAULT if failed (may not return if in kernel)
298 */
299
300/* Macros to determine offset from current PC for branch instructions */
301/* Explicit type coercion is used to force sign extension where needed */
302#define SH_PC_8BIT_OFFSET(instr) ((((signed char)(instr))*2) + 4)
303#define SH_PC_12BIT_OFFSET(instr) ((((signed short)(instr<<4))>>3) + 4)
304
305int handle_unaligned_access(insn_size_t instruction, struct pt_regs *regs,
306 struct mem_access *ma, int expected,
307 unsigned long address)
308{
309 u_int rm;
310 int ret, index;
311
312 /*
313 * XXX: We can't handle mixed 16/32-bit instructions yet
314 */
315 if (instruction_size(instruction) != 2)
316 return -EINVAL;
317
318 index = (instruction>>8)&15; /* 0x0F00 */
319 rm = regs->regs[index];
320
321 /*
322 * Log the unexpected fixups, and then pass them on to perf.
323 *
324 * We intentionally don't report the expected cases to perf as
325 * otherwise the trapped I/O case will skew the results too much
326 * to be useful.
327 */
328 if (!expected) {
329 unaligned_fixups_notify(current, instruction, regs);
330 perf_sw_event(PERF_COUNT_SW_ALIGNMENT_FAULTS, 1,
331 regs, address);
332 }
333
334 ret = -EFAULT;
335 switch (instruction&0xF000) {
336 case 0x0000:
337 if (instruction==0x000B) {
338 /* rts */
339 ret = handle_delayslot(regs, instruction, ma);
340 if (ret==0)
341 regs->pc = regs->pr;
342 }
343 else if ((instruction&0x00FF)==0x0023) {
344 /* braf @Rm */
345 ret = handle_delayslot(regs, instruction, ma);
346 if (ret==0)
347 regs->pc += rm + 4;
348 }
349 else if ((instruction&0x00FF)==0x0003) {
350 /* bsrf @Rm */
351 ret = handle_delayslot(regs, instruction, ma);
352 if (ret==0) {
353 regs->pr = regs->pc + 4;
354 regs->pc += rm + 4;
355 }
356 }
357 else {
358 /* mov.[bwl] to/from memory via r0+rn */
359 goto simple;
360 }
361 break;
362
363 case 0x1000: /* mov.l Rm,@(disp,Rn) */
364 goto simple;
365
366 case 0x2000: /* mov.[bwl] to memory, possibly with pre-decrement */
367 goto simple;
368
369 case 0x4000:
370 if ((instruction&0x00FF)==0x002B) {
371 /* jmp @Rm */
372 ret = handle_delayslot(regs, instruction, ma);
373 if (ret==0)
374 regs->pc = rm;
375 }
376 else if ((instruction&0x00FF)==0x000B) {
377 /* jsr @Rm */
378 ret = handle_delayslot(regs, instruction, ma);
379 if (ret==0) {
380 regs->pr = regs->pc + 4;
381 regs->pc = rm;
382 }
383 }
384 else {
385 /* mov.[bwl] to/from memory via r0+rn */
386 goto simple;
387 }
388 break;
389
390 case 0x5000: /* mov.l @(disp,Rm),Rn */
391 goto simple;
392
393 case 0x6000: /* mov.[bwl] from memory, possibly with post-increment */
394 goto simple;
395
396 case 0x8000: /* bf lab, bf/s lab, bt lab, bt/s lab */
397 switch (instruction&0x0F00) {
398 case 0x0100: /* mov.w R0,@(disp,Rm) */
399 goto simple;
400 case 0x0500: /* mov.w @(disp,Rm),R0 */
401 goto simple;
402 case 0x0B00: /* bf lab - no delayslot*/
403 ret = 0;
404 break;
405 case 0x0F00: /* bf/s lab */
406 ret = handle_delayslot(regs, instruction, ma);
407 if (ret==0) {
408#if defined(CONFIG_CPU_SH4) || defined(CONFIG_SH7705_CACHE_32KB)
409 if ((regs->sr & 0x00000001) != 0)
410 regs->pc += 4; /* next after slot */
411 else
412#endif
413 regs->pc += SH_PC_8BIT_OFFSET(instruction);
414 }
415 break;
416 case 0x0900: /* bt lab - no delayslot */
417 ret = 0;
418 break;
419 case 0x0D00: /* bt/s lab */
420 ret = handle_delayslot(regs, instruction, ma);
421 if (ret==0) {
422#if defined(CONFIG_CPU_SH4) || defined(CONFIG_SH7705_CACHE_32KB)
423 if ((regs->sr & 0x00000001) == 0)
424 regs->pc += 4; /* next after slot */
425 else
426#endif
427 regs->pc += SH_PC_8BIT_OFFSET(instruction);
428 }
429 break;
430 }
431 break;
432
433 case 0x9000: /* mov.w @(disp,Rm),Rn */
434 goto simple;
435
436 case 0xA000: /* bra label */
437 ret = handle_delayslot(regs, instruction, ma);
438 if (ret==0)
439 regs->pc += SH_PC_12BIT_OFFSET(instruction);
440 break;
441
442 case 0xB000: /* bsr label */
443 ret = handle_delayslot(regs, instruction, ma);
444 if (ret==0) {
445 regs->pr = regs->pc + 4;
446 regs->pc += SH_PC_12BIT_OFFSET(instruction);
447 }
448 break;
449
450 case 0xD000: /* mov.l @(disp,Rm),Rn */
451 goto simple;
452 }
453 return ret;
454
455 /* handle non-delay-slot instruction */
456 simple:
457 ret = handle_unaligned_ins(instruction, regs, ma);
458 if (ret==0)
459 regs->pc += instruction_size(instruction);
460 return ret;
461}
462
463/*
464 * Handle various address error exceptions:
465 * - instruction address error:
466 * misaligned PC
467 * PC >= 0x80000000 in user mode
468 * - data address error (read and write)
469 * misaligned data access
470 * access to >= 0x80000000 is user mode
471 * Unfortuntaly we can't distinguish between instruction address error
472 * and data address errors caused by read accesses.
473 */
474asmlinkage void do_address_error(struct pt_regs *regs,
475 unsigned long writeaccess,
476 unsigned long address)
477{
478 unsigned long error_code = 0;
479 mm_segment_t oldfs;
480 siginfo_t info;
481 insn_size_t instruction;
482 int tmp;
483
484 /* Intentional ifdef */
485#ifdef CONFIG_CPU_HAS_SR_RB
486 error_code = lookup_exception_vector();
487#endif
488
489 oldfs = get_fs();
490
491 if (user_mode(regs)) {
492 int si_code = BUS_ADRERR;
493 unsigned int user_action;
494
495 local_irq_enable();
496 inc_unaligned_user_access();
497
498 set_fs(USER_DS);
499 if (copy_from_user(&instruction, (insn_size_t *)(regs->pc & ~1),
500 sizeof(instruction))) {
501 set_fs(oldfs);
502 goto uspace_segv;
503 }
504 set_fs(oldfs);
505
506 /* shout about userspace fixups */
507 unaligned_fixups_notify(current, instruction, regs);
508
509 user_action = unaligned_user_action();
510 if (user_action & UM_FIXUP)
511 goto fixup;
512 if (user_action & UM_SIGNAL)
513 goto uspace_segv;
514 else {
515 /* ignore */
516 regs->pc += instruction_size(instruction);
517 return;
518 }
519
520fixup:
521 /* bad PC is not something we can fix */
522 if (regs->pc & 1) {
523 si_code = BUS_ADRALN;
524 goto uspace_segv;
525 }
526
527 set_fs(USER_DS);
528 tmp = handle_unaligned_access(instruction, regs,
529 &user_mem_access, 0,
530 address);
531 set_fs(oldfs);
532
533 if (tmp == 0)
534 return; /* sorted */
535uspace_segv:
536 printk(KERN_NOTICE "Sending SIGBUS to \"%s\" due to unaligned "
537 "access (PC %lx PR %lx)\n", current->comm, regs->pc,
538 regs->pr);
539
540 info.si_signo = SIGBUS;
541 info.si_errno = 0;
542 info.si_code = si_code;
543 info.si_addr = (void __user *)address;
544 force_sig_info(SIGBUS, &info, current);
545 } else {
546 inc_unaligned_kernel_access();
547
548 if (regs->pc & 1)
549 die("unaligned program counter", regs, error_code);
550
551 set_fs(KERNEL_DS);
552 if (copy_from_user(&instruction, (void __user *)(regs->pc),
553 sizeof(instruction))) {
554 /* Argh. Fault on the instruction itself.
555 This should never happen non-SMP
556 */
557 set_fs(oldfs);
558 die("insn faulting in do_address_error", regs, 0);
559 }
560
561 unaligned_fixups_notify(current, instruction, regs);
562
563 handle_unaligned_access(instruction, regs, &user_mem_access,
564 0, address);
565 set_fs(oldfs);
566 }
567}
568
569#ifdef CONFIG_SH_DSP
570/*
571 * SH-DSP support gerg@snapgear.com.
572 */
573int is_dsp_inst(struct pt_regs *regs)
574{
575 unsigned short inst = 0;
576
577 /*
578 * Safe guard if DSP mode is already enabled or we're lacking
579 * the DSP altogether.
580 */
581 if (!(current_cpu_data.flags & CPU_HAS_DSP) || (regs->sr & SR_DSP))
582 return 0;
583
584 get_user(inst, ((unsigned short *) regs->pc));
585
586 inst &= 0xf000;
587
588 /* Check for any type of DSP or support instruction */
589 if ((inst == 0xf000) || (inst == 0x4000))
590 return 1;
591
592 return 0;
593}
594#else
595#define is_dsp_inst(regs) (0)
596#endif /* CONFIG_SH_DSP */
597
598#ifdef CONFIG_CPU_SH2A
599asmlinkage void do_divide_error(unsigned long r4)
600{
601 siginfo_t info;
602
603 switch (r4) {
604 case TRAP_DIVZERO_ERROR:
605 info.si_code = FPE_INTDIV;
606 break;
607 case TRAP_DIVOVF_ERROR:
608 info.si_code = FPE_INTOVF;
609 break;
610 }
611
612 info.si_signo = SIGFPE;
613 force_sig_info(info.si_signo, &info, current);
614}
615#endif
616
617asmlinkage void do_reserved_inst(void)
618{
619 struct pt_regs *regs = current_pt_regs();
620 unsigned long error_code;
621 struct task_struct *tsk = current;
622
623#ifdef CONFIG_SH_FPU_EMU
624 unsigned short inst = 0;
625 int err;
626
627 get_user(inst, (unsigned short*)regs->pc);
628
629 err = do_fpu_inst(inst, regs);
630 if (!err) {
631 regs->pc += instruction_size(inst);
632 return;
633 }
634 /* not a FPU inst. */
635#endif
636
637#ifdef CONFIG_SH_DSP
638 /* Check if it's a DSP instruction */
639 if (is_dsp_inst(regs)) {
640 /* Enable DSP mode, and restart instruction. */
641 regs->sr |= SR_DSP;
642 /* Save DSP mode */
643 tsk->thread.dsp_status.status |= SR_DSP;
644 return;
645 }
646#endif
647
648 error_code = lookup_exception_vector();
649
650 local_irq_enable();
651 force_sig(SIGILL, tsk);
652 die_if_no_fixup("reserved instruction", regs, error_code);
653}
654
655#ifdef CONFIG_SH_FPU_EMU
656static int emulate_branch(unsigned short inst, struct pt_regs *regs)
657{
658 /*
659 * bfs: 8fxx: PC+=d*2+4;
660 * bts: 8dxx: PC+=d*2+4;
661 * bra: axxx: PC+=D*2+4;
662 * bsr: bxxx: PC+=D*2+4 after PR=PC+4;
663 * braf:0x23: PC+=Rn*2+4;
664 * bsrf:0x03: PC+=Rn*2+4 after PR=PC+4;
665 * jmp: 4x2b: PC=Rn;
666 * jsr: 4x0b: PC=Rn after PR=PC+4;
667 * rts: 000b: PC=PR;
668 */
669 if (((inst & 0xf000) == 0xb000) || /* bsr */
670 ((inst & 0xf0ff) == 0x0003) || /* bsrf */
671 ((inst & 0xf0ff) == 0x400b)) /* jsr */
672 regs->pr = regs->pc + 4;
673
674 if ((inst & 0xfd00) == 0x8d00) { /* bfs, bts */
675 regs->pc += SH_PC_8BIT_OFFSET(inst);
676 return 0;
677 }
678
679 if ((inst & 0xe000) == 0xa000) { /* bra, bsr */
680 regs->pc += SH_PC_12BIT_OFFSET(inst);
681 return 0;
682 }
683
684 if ((inst & 0xf0df) == 0x0003) { /* braf, bsrf */
685 regs->pc += regs->regs[(inst & 0x0f00) >> 8] + 4;
686 return 0;
687 }
688
689 if ((inst & 0xf0df) == 0x400b) { /* jmp, jsr */
690 regs->pc = regs->regs[(inst & 0x0f00) >> 8];
691 return 0;
692 }
693
694 if ((inst & 0xffff) == 0x000b) { /* rts */
695 regs->pc = regs->pr;
696 return 0;
697 }
698
699 return 1;
700}
701#endif
702
703asmlinkage void do_illegal_slot_inst(void)
704{
705 struct pt_regs *regs = current_pt_regs();
706 unsigned long inst;
707 struct task_struct *tsk = current;
708
709 if (kprobe_handle_illslot(regs->pc) == 0)
710 return;
711
712#ifdef CONFIG_SH_FPU_EMU
713 get_user(inst, (unsigned short *)regs->pc + 1);
714 if (!do_fpu_inst(inst, regs)) {
715 get_user(inst, (unsigned short *)regs->pc);
716 if (!emulate_branch(inst, regs))
717 return;
718 /* fault in branch.*/
719 }
720 /* not a FPU inst. */
721#endif
722
723 inst = lookup_exception_vector();
724
725 local_irq_enable();
726 force_sig(SIGILL, tsk);
727 die_if_no_fixup("illegal slot instruction", regs, inst);
728}
729
730asmlinkage void do_exception_error(void)
731{
732 long ex;
733
734 ex = lookup_exception_vector();
735 die_if_kernel("exception", current_pt_regs(), ex);
736}
737
738void per_cpu_trap_init(void)
739{
740 extern void *vbr_base;
741
742 /* NOTE: The VBR value should be at P1
743 (or P2, virtural "fixed" address space).
744 It's definitely should not in physical address. */
745
746 asm volatile("ldc %0, vbr"
747 : /* no output */
748 : "r" (&vbr_base)
749 : "memory");
750
751 /* disable exception blocking now when the vbr has been setup */
752 clear_bl_bit();
753}
754
755void *set_exception_table_vec(unsigned int vec, void *handler)
756{
757 extern void *exception_handling_table[];
758 void *old_handler;
759
760 old_handler = exception_handling_table[vec];
761 exception_handling_table[vec] = handler;
762 return old_handler;
763}
764
765void __init trap_init(void)
766{
767 set_exception_table_vec(TRAP_RESERVED_INST, do_reserved_inst);
768 set_exception_table_vec(TRAP_ILLEGAL_SLOT_INST, do_illegal_slot_inst);
769
770#if defined(CONFIG_CPU_SH4) && !defined(CONFIG_SH_FPU) || \
771 defined(CONFIG_SH_FPU_EMU)
772 /*
773 * For SH-4 lacking an FPU, treat floating point instructions as
774 * reserved. They'll be handled in the math-emu case, or faulted on
775 * otherwise.
776 */
777 set_exception_table_evt(0x800, do_reserved_inst);
778 set_exception_table_evt(0x820, do_illegal_slot_inst);
779#elif defined(CONFIG_SH_FPU)
780 set_exception_table_evt(0x800, fpu_state_restore_trap_handler);
781 set_exception_table_evt(0x820, fpu_state_restore_trap_handler);
782#endif
783
784#ifdef CONFIG_CPU_SH2
785 set_exception_table_vec(TRAP_ADDRESS_ERROR, address_error_trap_handler);
786#endif
787#ifdef CONFIG_CPU_SH2A
788 set_exception_table_vec(TRAP_DIVZERO_ERROR, do_divide_error);
789 set_exception_table_vec(TRAP_DIVOVF_ERROR, do_divide_error);
790#ifdef CONFIG_SH_FPU
791 set_exception_table_vec(TRAP_FPU_ERROR, fpu_error_trap_handler);
792#endif
793#endif
794
795#ifdef TRAP_UBC
796 set_exception_table_vec(TRAP_UBC, breakpoint_trap_handler);
797#endif
798}