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