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