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