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0d05fb3c48e3dc9d068eae3d4a9c41e4c2996495
[deliverable/linux.git] / arch / sh / kernel / traps_32.c
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 - 2007 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/init.h>
17 #include <linux/spinlock.h>
18 #include <linux/module.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/kexec.h>
25 #include <linux/limits.h>
26 #include <asm/system.h>
27 #include <asm/uaccess.h>
28
29 #ifdef CONFIG_SH_KGDB
30 #include <asm/kgdb.h>
31 #define CHK_REMOTE_DEBUG(regs) \
32 { \
33 if (kgdb_debug_hook && !user_mode(regs))\
34 (*kgdb_debug_hook)(regs); \
35 }
36 #else
37 #define CHK_REMOTE_DEBUG(regs)
38 #endif
39
40 #ifdef CONFIG_CPU_SH2
41 # define TRAP_RESERVED_INST 4
42 # define TRAP_ILLEGAL_SLOT_INST 6
43 # define TRAP_ADDRESS_ERROR 9
44 # ifdef CONFIG_CPU_SH2A
45 # define TRAP_DIVZERO_ERROR 17
46 # define TRAP_DIVOVF_ERROR 18
47 # endif
48 #else
49 #define TRAP_RESERVED_INST 12
50 #define TRAP_ILLEGAL_SLOT_INST 13
51 #endif
52
53 static void dump_mem(const char *str, unsigned long bottom, unsigned long top)
54 {
55 unsigned long p;
56 int i;
57
58 printk("%s(0x%08lx to 0x%08lx)\n", str, bottom, top);
59
60 for (p = bottom & ~31; p < top; ) {
61 printk("%04lx: ", p & 0xffff);
62
63 for (i = 0; i < 8; i++, p += 4) {
64 unsigned int val;
65
66 if (p < bottom || p >= top)
67 printk(" ");
68 else {
69 if (__get_user(val, (unsigned int __user *)p)) {
70 printk("\n");
71 return;
72 }
73 printk("%08x ", val);
74 }
75 }
76 printk("\n");
77 }
78 }
79
80 static DEFINE_SPINLOCK(die_lock);
81
82 void die(const char * str, struct pt_regs * regs, long err)
83 {
84 static int die_counter;
85
86 oops_enter();
87
88 console_verbose();
89 spin_lock_irq(&die_lock);
90 bust_spinlocks(1);
91
92 printk("%s: %04lx [#%d]\n", str, err & 0xffff, ++die_counter);
93
94 CHK_REMOTE_DEBUG(regs);
95 print_modules();
96 show_regs(regs);
97
98 printk("Process: %s (pid: %d, stack limit = %p)\n", current->comm,
99 task_pid_nr(current), task_stack_page(current) + 1);
100
101 if (!user_mode(regs) || in_interrupt())
102 dump_mem("Stack: ", regs->regs[15], THREAD_SIZE +
103 (unsigned long)task_stack_page(current));
104
105 bust_spinlocks(0);
106 add_taint(TAINT_DIE);
107 spin_unlock_irq(&die_lock);
108
109 if (kexec_should_crash(current))
110 crash_kexec(regs);
111
112 if (in_interrupt())
113 panic("Fatal exception in interrupt");
114
115 if (panic_on_oops)
116 panic("Fatal exception");
117
118 oops_exit();
119 do_exit(SIGSEGV);
120 }
121
122 static inline void die_if_kernel(const char *str, struct pt_regs *regs,
123 long err)
124 {
125 if (!user_mode(regs))
126 die(str, regs, err);
127 }
128
129 /*
130 * try and fix up kernelspace address errors
131 * - userspace errors just cause EFAULT to be returned, resulting in SEGV
132 * - kernel/userspace interfaces cause a jump to an appropriate handler
133 * - other kernel errors are bad
134 * - return 0 if fixed-up, -EFAULT if non-fatal (to the kernel) fault
135 */
136 static int die_if_no_fixup(const char * str, struct pt_regs * regs, long err)
137 {
138 if (!user_mode(regs)) {
139 const struct exception_table_entry *fixup;
140 fixup = search_exception_tables(regs->pc);
141 if (fixup) {
142 regs->pc = fixup->fixup;
143 return 0;
144 }
145 die(str, regs, err);
146 }
147 return -EFAULT;
148 }
149
150 /*
151 * handle an instruction that does an unaligned memory access by emulating the
152 * desired behaviour
153 * - note that PC _may not_ point to the faulting instruction
154 * (if that instruction is in a branch delay slot)
155 * - return 0 if emulation okay, -EFAULT on existential error
156 */
157 static int handle_unaligned_ins(u16 instruction, struct pt_regs *regs)
158 {
159 int ret, index, count;
160 unsigned long *rm, *rn;
161 unsigned char *src, *dst;
162
163 index = (instruction>>8)&15; /* 0x0F00 */
164 rn = &regs->regs[index];
165
166 index = (instruction>>4)&15; /* 0x00F0 */
167 rm = &regs->regs[index];
168
169 count = 1<<(instruction&3);
170
171 ret = -EFAULT;
172 switch (instruction>>12) {
173 case 0: /* mov.[bwl] to/from memory via r0+rn */
174 if (instruction & 8) {
175 /* from memory */
176 src = (unsigned char*) *rm;
177 src += regs->regs[0];
178 dst = (unsigned char*) rn;
179 *(unsigned long*)dst = 0;
180
181 #ifdef __LITTLE_ENDIAN__
182 if (copy_from_user(dst, src, count))
183 goto fetch_fault;
184
185 if ((count == 2) && dst[1] & 0x80) {
186 dst[2] = 0xff;
187 dst[3] = 0xff;
188 }
189 #else
190 dst += 4-count;
191
192 if (__copy_user(dst, src, count))
193 goto fetch_fault;
194
195 if ((count == 2) && dst[2] & 0x80) {
196 dst[0] = 0xff;
197 dst[1] = 0xff;
198 }
199 #endif
200 } else {
201 /* to memory */
202 src = (unsigned char*) rm;
203 #if !defined(__LITTLE_ENDIAN__)
204 src += 4-count;
205 #endif
206 dst = (unsigned char*) *rn;
207 dst += regs->regs[0];
208
209 if (copy_to_user(dst, src, count))
210 goto fetch_fault;
211 }
212 ret = 0;
213 break;
214
215 case 1: /* mov.l Rm,@(disp,Rn) */
216 src = (unsigned char*) rm;
217 dst = (unsigned char*) *rn;
218 dst += (instruction&0x000F)<<2;
219
220 if (copy_to_user(dst,src,4))
221 goto fetch_fault;
222 ret = 0;
223 break;
224
225 case 2: /* mov.[bwl] to memory, possibly with pre-decrement */
226 if (instruction & 4)
227 *rn -= count;
228 src = (unsigned char*) rm;
229 dst = (unsigned char*) *rn;
230 #if !defined(__LITTLE_ENDIAN__)
231 src += 4-count;
232 #endif
233 if (copy_to_user(dst, src, count))
234 goto fetch_fault;
235 ret = 0;
236 break;
237
238 case 5: /* mov.l @(disp,Rm),Rn */
239 src = (unsigned char*) *rm;
240 src += (instruction&0x000F)<<2;
241 dst = (unsigned char*) rn;
242 *(unsigned long*)dst = 0;
243
244 if (copy_from_user(dst,src,4))
245 goto fetch_fault;
246 ret = 0;
247 break;
248
249 case 6: /* mov.[bwl] from memory, possibly with post-increment */
250 src = (unsigned char*) *rm;
251 if (instruction & 4)
252 *rm += count;
253 dst = (unsigned char*) rn;
254 *(unsigned long*)dst = 0;
255
256 #ifdef __LITTLE_ENDIAN__
257 if (copy_from_user(dst, src, count))
258 goto fetch_fault;
259
260 if ((count == 2) && dst[1] & 0x80) {
261 dst[2] = 0xff;
262 dst[3] = 0xff;
263 }
264 #else
265 dst += 4-count;
266
267 if (copy_from_user(dst, src, count))
268 goto fetch_fault;
269
270 if ((count == 2) && dst[2] & 0x80) {
271 dst[0] = 0xff;
272 dst[1] = 0xff;
273 }
274 #endif
275 ret = 0;
276 break;
277
278 case 8:
279 switch ((instruction&0xFF00)>>8) {
280 case 0x81: /* mov.w R0,@(disp,Rn) */
281 src = (unsigned char*) &regs->regs[0];
282 #if !defined(__LITTLE_ENDIAN__)
283 src += 2;
284 #endif
285 dst = (unsigned char*) *rm; /* called Rn in the spec */
286 dst += (instruction&0x000F)<<1;
287
288 if (copy_to_user(dst, src, 2))
289 goto fetch_fault;
290 ret = 0;
291 break;
292
293 case 0x85: /* mov.w @(disp,Rm),R0 */
294 src = (unsigned char*) *rm;
295 src += (instruction&0x000F)<<1;
296 dst = (unsigned char*) &regs->regs[0];
297 *(unsigned long*)dst = 0;
298
299 #if !defined(__LITTLE_ENDIAN__)
300 dst += 2;
301 #endif
302
303 if (copy_from_user(dst, src, 2))
304 goto fetch_fault;
305
306 #ifdef __LITTLE_ENDIAN__
307 if (dst[1] & 0x80) {
308 dst[2] = 0xff;
309 dst[3] = 0xff;
310 }
311 #else
312 if (dst[2] & 0x80) {
313 dst[0] = 0xff;
314 dst[1] = 0xff;
315 }
316 #endif
317 ret = 0;
318 break;
319 }
320 break;
321 }
322 return ret;
323
324 fetch_fault:
325 /* Argh. Address not only misaligned but also non-existent.
326 * Raise an EFAULT and see if it's trapped
327 */
328 return die_if_no_fixup("Fault in unaligned fixup", regs, 0);
329 }
330
331 /*
332 * emulate the instruction in the delay slot
333 * - fetches the instruction from PC+2
334 */
335 static inline int handle_unaligned_delayslot(struct pt_regs *regs)
336 {
337 u16 instruction;
338
339 if (copy_from_user(&instruction, (u16 *)(regs->pc+2), 2)) {
340 /* the instruction-fetch faulted */
341 if (user_mode(regs))
342 return -EFAULT;
343
344 /* kernel */
345 die("delay-slot-insn faulting in handle_unaligned_delayslot",
346 regs, 0);
347 }
348
349 return handle_unaligned_ins(instruction,regs);
350 }
351
352 /*
353 * handle an instruction that does an unaligned memory access
354 * - have to be careful of branch delay-slot instructions that fault
355 * SH3:
356 * - if the branch would be taken PC points to the branch
357 * - if the branch would not be taken, PC points to delay-slot
358 * SH4:
359 * - PC always points to delayed branch
360 * - return 0 if handled, -EFAULT if failed (may not return if in kernel)
361 */
362
363 /* Macros to determine offset from current PC for branch instructions */
364 /* Explicit type coercion is used to force sign extension where needed */
365 #define SH_PC_8BIT_OFFSET(instr) ((((signed char)(instr))*2) + 4)
366 #define SH_PC_12BIT_OFFSET(instr) ((((signed short)(instr<<4))>>3) + 4)
367
368 /*
369 * XXX: SH-2A needs this too, but it needs an overhaul thanks to mixed 32-bit
370 * opcodes..
371 */
372 #ifndef CONFIG_CPU_SH2A
373 static int handle_unaligned_notify_count = 10;
374
375 static int handle_unaligned_access(u16 instruction, struct pt_regs *regs)
376 {
377 u_int rm;
378 int ret, index;
379
380 index = (instruction>>8)&15; /* 0x0F00 */
381 rm = regs->regs[index];
382
383 /* shout about the first ten userspace fixups */
384 if (user_mode(regs) && handle_unaligned_notify_count>0) {
385 handle_unaligned_notify_count--;
386
387 printk(KERN_NOTICE "Fixing up unaligned userspace access "
388 "in \"%s\" pid=%d pc=0x%p ins=0x%04hx\n",
389 current->comm, task_pid_nr(current),
390 (u16 *)regs->pc, instruction);
391 }
392
393 ret = -EFAULT;
394 switch (instruction&0xF000) {
395 case 0x0000:
396 if (instruction==0x000B) {
397 /* rts */
398 ret = handle_unaligned_delayslot(regs);
399 if (ret==0)
400 regs->pc = regs->pr;
401 }
402 else if ((instruction&0x00FF)==0x0023) {
403 /* braf @Rm */
404 ret = handle_unaligned_delayslot(regs);
405 if (ret==0)
406 regs->pc += rm + 4;
407 }
408 else if ((instruction&0x00FF)==0x0003) {
409 /* bsrf @Rm */
410 ret = handle_unaligned_delayslot(regs);
411 if (ret==0) {
412 regs->pr = regs->pc + 4;
413 regs->pc += rm + 4;
414 }
415 }
416 else {
417 /* mov.[bwl] to/from memory via r0+rn */
418 goto simple;
419 }
420 break;
421
422 case 0x1000: /* mov.l Rm,@(disp,Rn) */
423 goto simple;
424
425 case 0x2000: /* mov.[bwl] to memory, possibly with pre-decrement */
426 goto simple;
427
428 case 0x4000:
429 if ((instruction&0x00FF)==0x002B) {
430 /* jmp @Rm */
431 ret = handle_unaligned_delayslot(regs);
432 if (ret==0)
433 regs->pc = rm;
434 }
435 else if ((instruction&0x00FF)==0x000B) {
436 /* jsr @Rm */
437 ret = handle_unaligned_delayslot(regs);
438 if (ret==0) {
439 regs->pr = regs->pc + 4;
440 regs->pc = rm;
441 }
442 }
443 else {
444 /* mov.[bwl] to/from memory via r0+rn */
445 goto simple;
446 }
447 break;
448
449 case 0x5000: /* mov.l @(disp,Rm),Rn */
450 goto simple;
451
452 case 0x6000: /* mov.[bwl] from memory, possibly with post-increment */
453 goto simple;
454
455 case 0x8000: /* bf lab, bf/s lab, bt lab, bt/s lab */
456 switch (instruction&0x0F00) {
457 case 0x0100: /* mov.w R0,@(disp,Rm) */
458 goto simple;
459 case 0x0500: /* mov.w @(disp,Rm),R0 */
460 goto simple;
461 case 0x0B00: /* bf lab - no delayslot*/
462 break;
463 case 0x0F00: /* bf/s lab */
464 ret = handle_unaligned_delayslot(regs);
465 if (ret==0) {
466 #if defined(CONFIG_CPU_SH4) || defined(CONFIG_SH7705_CACHE_32KB)
467 if ((regs->sr & 0x00000001) != 0)
468 regs->pc += 4; /* next after slot */
469 else
470 #endif
471 regs->pc += SH_PC_8BIT_OFFSET(instruction);
472 }
473 break;
474 case 0x0900: /* bt lab - no delayslot */
475 break;
476 case 0x0D00: /* bt/s lab */
477 ret = handle_unaligned_delayslot(regs);
478 if (ret==0) {
479 #if defined(CONFIG_CPU_SH4) || defined(CONFIG_SH7705_CACHE_32KB)
480 if ((regs->sr & 0x00000001) == 0)
481 regs->pc += 4; /* next after slot */
482 else
483 #endif
484 regs->pc += SH_PC_8BIT_OFFSET(instruction);
485 }
486 break;
487 }
488 break;
489
490 case 0xA000: /* bra label */
491 ret = handle_unaligned_delayslot(regs);
492 if (ret==0)
493 regs->pc += SH_PC_12BIT_OFFSET(instruction);
494 break;
495
496 case 0xB000: /* bsr label */
497 ret = handle_unaligned_delayslot(regs);
498 if (ret==0) {
499 regs->pr = regs->pc + 4;
500 regs->pc += SH_PC_12BIT_OFFSET(instruction);
501 }
502 break;
503 }
504 return ret;
505
506 /* handle non-delay-slot instruction */
507 simple:
508 ret = handle_unaligned_ins(instruction,regs);
509 if (ret==0)
510 regs->pc += instruction_size(instruction);
511 return ret;
512 }
513 #endif /* CONFIG_CPU_SH2A */
514
515 #ifdef CONFIG_CPU_HAS_SR_RB
516 #define lookup_exception_vector(x) \
517 __asm__ __volatile__ ("stc r2_bank, %0\n\t" : "=r" ((x)))
518 #else
519 #define lookup_exception_vector(x) \
520 __asm__ __volatile__ ("mov r4, %0\n\t" : "=r" ((x)))
521 #endif
522
523 /*
524 * Handle various address error exceptions:
525 * - instruction address error:
526 * misaligned PC
527 * PC >= 0x80000000 in user mode
528 * - data address error (read and write)
529 * misaligned data access
530 * access to >= 0x80000000 is user mode
531 * Unfortuntaly we can't distinguish between instruction address error
532 * and data address errors caused by read accesses.
533 */
534 asmlinkage void do_address_error(struct pt_regs *regs,
535 unsigned long writeaccess,
536 unsigned long address)
537 {
538 unsigned long error_code = 0;
539 mm_segment_t oldfs;
540 siginfo_t info;
541 #ifndef CONFIG_CPU_SH2A
542 u16 instruction;
543 int tmp;
544 #endif
545
546 /* Intentional ifdef */
547 #ifdef CONFIG_CPU_HAS_SR_RB
548 lookup_exception_vector(error_code);
549 #endif
550
551 oldfs = get_fs();
552
553 if (user_mode(regs)) {
554 int si_code = BUS_ADRERR;
555
556 local_irq_enable();
557
558 /* bad PC is not something we can fix */
559 if (regs->pc & 1) {
560 si_code = BUS_ADRALN;
561 goto uspace_segv;
562 }
563
564 #ifndef CONFIG_CPU_SH2A
565 set_fs(USER_DS);
566 if (copy_from_user(&instruction, (u16 *)(regs->pc), 2)) {
567 /* Argh. Fault on the instruction itself.
568 This should never happen non-SMP
569 */
570 set_fs(oldfs);
571 goto uspace_segv;
572 }
573
574 tmp = handle_unaligned_access(instruction, regs);
575 set_fs(oldfs);
576
577 if (tmp==0)
578 return; /* sorted */
579 #endif
580
581 uspace_segv:
582 printk(KERN_NOTICE "Sending SIGBUS to \"%s\" due to unaligned "
583 "access (PC %lx PR %lx)\n", current->comm, regs->pc,
584 regs->pr);
585
586 info.si_signo = SIGBUS;
587 info.si_errno = 0;
588 info.si_code = si_code;
589 info.si_addr = (void __user *)address;
590 force_sig_info(SIGBUS, &info, current);
591 } else {
592 if (regs->pc & 1)
593 die("unaligned program counter", regs, error_code);
594
595 #ifndef CONFIG_CPU_SH2A
596 set_fs(KERNEL_DS);
597 if (copy_from_user(&instruction, (u16 *)(regs->pc), 2)) {
598 /* Argh. Fault on the instruction itself.
599 This should never happen non-SMP
600 */
601 set_fs(oldfs);
602 die("insn faulting in do_address_error", regs, 0);
603 }
604
605 handle_unaligned_access(instruction, regs);
606 set_fs(oldfs);
607 #else
608 printk(KERN_NOTICE "Killing process \"%s\" due to unaligned "
609 "access\n", current->comm);
610
611 force_sig(SIGSEGV, current);
612 #endif
613 }
614 }
615
616 #ifdef CONFIG_SH_DSP
617 /*
618 * SH-DSP support gerg@snapgear.com.
619 */
620 int is_dsp_inst(struct pt_regs *regs)
621 {
622 unsigned short inst = 0;
623
624 /*
625 * Safe guard if DSP mode is already enabled or we're lacking
626 * the DSP altogether.
627 */
628 if (!(current_cpu_data.flags & CPU_HAS_DSP) || (regs->sr & SR_DSP))
629 return 0;
630
631 get_user(inst, ((unsigned short *) regs->pc));
632
633 inst &= 0xf000;
634
635 /* Check for any type of DSP or support instruction */
636 if ((inst == 0xf000) || (inst == 0x4000))
637 return 1;
638
639 return 0;
640 }
641 #else
642 #define is_dsp_inst(regs) (0)
643 #endif /* CONFIG_SH_DSP */
644
645 #ifdef CONFIG_CPU_SH2A
646 asmlinkage void do_divide_error(unsigned long r4, unsigned long r5,
647 unsigned long r6, unsigned long r7,
648 struct pt_regs __regs)
649 {
650 siginfo_t info;
651
652 switch (r4) {
653 case TRAP_DIVZERO_ERROR:
654 info.si_code = FPE_INTDIV;
655 break;
656 case TRAP_DIVOVF_ERROR:
657 info.si_code = FPE_INTOVF;
658 break;
659 }
660
661 force_sig_info(SIGFPE, &info, current);
662 }
663 #endif
664
665 /* arch/sh/kernel/cpu/sh4/fpu.c */
666 extern int do_fpu_inst(unsigned short, struct pt_regs *);
667 extern asmlinkage void do_fpu_state_restore(unsigned long r4, unsigned long r5,
668 unsigned long r6, unsigned long r7, struct pt_regs __regs);
669
670 asmlinkage void do_reserved_inst(unsigned long r4, unsigned long r5,
671 unsigned long r6, unsigned long r7,
672 struct pt_regs __regs)
673 {
674 struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
675 unsigned long error_code;
676 struct task_struct *tsk = current;
677
678 #ifdef CONFIG_SH_FPU_EMU
679 unsigned short inst = 0;
680 int err;
681
682 get_user(inst, (unsigned short*)regs->pc);
683
684 err = do_fpu_inst(inst, regs);
685 if (!err) {
686 regs->pc += instruction_size(inst);
687 return;
688 }
689 /* not a FPU inst. */
690 #endif
691
692 #ifdef CONFIG_SH_DSP
693 /* Check if it's a DSP instruction */
694 if (is_dsp_inst(regs)) {
695 /* Enable DSP mode, and restart instruction. */
696 regs->sr |= SR_DSP;
697 return;
698 }
699 #endif
700
701 lookup_exception_vector(error_code);
702
703 local_irq_enable();
704 CHK_REMOTE_DEBUG(regs);
705 force_sig(SIGILL, tsk);
706 die_if_no_fixup("reserved instruction", regs, error_code);
707 }
708
709 #ifdef CONFIG_SH_FPU_EMU
710 static int emulate_branch(unsigned short inst, struct pt_regs* regs)
711 {
712 /*
713 * bfs: 8fxx: PC+=d*2+4;
714 * bts: 8dxx: PC+=d*2+4;
715 * bra: axxx: PC+=D*2+4;
716 * bsr: bxxx: PC+=D*2+4 after PR=PC+4;
717 * braf:0x23: PC+=Rn*2+4;
718 * bsrf:0x03: PC+=Rn*2+4 after PR=PC+4;
719 * jmp: 4x2b: PC=Rn;
720 * jsr: 4x0b: PC=Rn after PR=PC+4;
721 * rts: 000b: PC=PR;
722 */
723 if ((inst & 0xfd00) == 0x8d00) {
724 regs->pc += SH_PC_8BIT_OFFSET(inst);
725 return 0;
726 }
727
728 if ((inst & 0xe000) == 0xa000) {
729 regs->pc += SH_PC_12BIT_OFFSET(inst);
730 return 0;
731 }
732
733 if ((inst & 0xf0df) == 0x0003) {
734 regs->pc += regs->regs[(inst & 0x0f00) >> 8] + 4;
735 return 0;
736 }
737
738 if ((inst & 0xf0df) == 0x400b) {
739 regs->pc = regs->regs[(inst & 0x0f00) >> 8];
740 return 0;
741 }
742
743 if ((inst & 0xffff) == 0x000b) {
744 regs->pc = regs->pr;
745 return 0;
746 }
747
748 return 1;
749 }
750 #endif
751
752 asmlinkage void do_illegal_slot_inst(unsigned long r4, unsigned long r5,
753 unsigned long r6, unsigned long r7,
754 struct pt_regs __regs)
755 {
756 struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
757 unsigned long error_code;
758 struct task_struct *tsk = current;
759 #ifdef CONFIG_SH_FPU_EMU
760 unsigned short inst = 0;
761
762 get_user(inst, (unsigned short *)regs->pc + 1);
763 if (!do_fpu_inst(inst, regs)) {
764 get_user(inst, (unsigned short *)regs->pc);
765 if (!emulate_branch(inst, regs))
766 return;
767 /* fault in branch.*/
768 }
769 /* not a FPU inst. */
770 #endif
771
772 lookup_exception_vector(error_code);
773
774 local_irq_enable();
775 CHK_REMOTE_DEBUG(regs);
776 force_sig(SIGILL, tsk);
777 die_if_no_fixup("illegal slot instruction", regs, error_code);
778 }
779
780 asmlinkage void do_exception_error(unsigned long r4, unsigned long r5,
781 unsigned long r6, unsigned long r7,
782 struct pt_regs __regs)
783 {
784 struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
785 long ex;
786
787 lookup_exception_vector(ex);
788 die_if_kernel("exception", regs, ex);
789 }
790
791 #if defined(CONFIG_SH_STANDARD_BIOS)
792 void *gdb_vbr_vector;
793
794 static inline void __init gdb_vbr_init(void)
795 {
796 register unsigned long vbr;
797
798 /*
799 * Read the old value of the VBR register to initialise
800 * the vector through which debug and BIOS traps are
801 * delegated by the Linux trap handler.
802 */
803 asm volatile("stc vbr, %0" : "=r" (vbr));
804
805 gdb_vbr_vector = (void *)(vbr + 0x100);
806 printk("Setting GDB trap vector to 0x%08lx\n",
807 (unsigned long)gdb_vbr_vector);
808 }
809 #endif
810
811 void __cpuinit per_cpu_trap_init(void)
812 {
813 extern void *vbr_base;
814
815 #ifdef CONFIG_SH_STANDARD_BIOS
816 if (raw_smp_processor_id() == 0)
817 gdb_vbr_init();
818 #endif
819
820 /* NOTE: The VBR value should be at P1
821 (or P2, virtural "fixed" address space).
822 It's definitely should not in physical address. */
823
824 asm volatile("ldc %0, vbr"
825 : /* no output */
826 : "r" (&vbr_base)
827 : "memory");
828 }
829
830 void *set_exception_table_vec(unsigned int vec, void *handler)
831 {
832 extern void *exception_handling_table[];
833 void *old_handler;
834
835 old_handler = exception_handling_table[vec];
836 exception_handling_table[vec] = handler;
837 return old_handler;
838 }
839
840 void __init trap_init(void)
841 {
842 set_exception_table_vec(TRAP_RESERVED_INST, do_reserved_inst);
843 set_exception_table_vec(TRAP_ILLEGAL_SLOT_INST, do_illegal_slot_inst);
844
845 #if defined(CONFIG_CPU_SH4) && !defined(CONFIG_SH_FPU) || \
846 defined(CONFIG_SH_FPU_EMU)
847 /*
848 * For SH-4 lacking an FPU, treat floating point instructions as
849 * reserved. They'll be handled in the math-emu case, or faulted on
850 * otherwise.
851 */
852 set_exception_table_evt(0x800, do_reserved_inst);
853 set_exception_table_evt(0x820, do_illegal_slot_inst);
854 #elif defined(CONFIG_SH_FPU)
855 #ifdef CONFIG_CPU_SUBTYPE_SHX3
856 set_exception_table_evt(0xd80, do_fpu_state_restore);
857 set_exception_table_evt(0xda0, do_fpu_state_restore);
858 #else
859 set_exception_table_evt(0x800, do_fpu_state_restore);
860 set_exception_table_evt(0x820, do_fpu_state_restore);
861 #endif
862 #endif
863
864 #ifdef CONFIG_CPU_SH2
865 set_exception_table_vec(TRAP_ADDRESS_ERROR, address_error_trap_handler);
866 #endif
867 #ifdef CONFIG_CPU_SH2A
868 set_exception_table_vec(TRAP_DIVZERO_ERROR, do_divide_error);
869 set_exception_table_vec(TRAP_DIVOVF_ERROR, do_divide_error);
870 #endif
871
872 /* Setup VBR for boot cpu */
873 per_cpu_trap_init();
874 }
875
876 void show_trace(struct task_struct *tsk, unsigned long *sp,
877 struct pt_regs *regs)
878 {
879 unsigned long addr;
880
881 if (regs && user_mode(regs))
882 return;
883
884 printk("\nCall trace: ");
885 #ifdef CONFIG_KALLSYMS
886 printk("\n");
887 #endif
888
889 while (!kstack_end(sp)) {
890 addr = *sp++;
891 if (kernel_text_address(addr))
892 print_ip_sym(addr);
893 }
894
895 printk("\n");
896
897 if (!tsk)
898 tsk = current;
899
900 debug_show_held_locks(tsk);
901 }
902
903 void show_stack(struct task_struct *tsk, unsigned long *sp)
904 {
905 unsigned long stack;
906
907 if (!tsk)
908 tsk = current;
909 if (tsk == current)
910 sp = (unsigned long *)current_stack_pointer;
911 else
912 sp = (unsigned long *)tsk->thread.sp;
913
914 stack = (unsigned long)sp;
915 dump_mem("Stack: ", stack, THREAD_SIZE +
916 (unsigned long)task_stack_page(tsk));
917 show_trace(tsk, sp, NULL);
918 }
919
920 void dump_stack(void)
921 {
922 show_stack(NULL, NULL);
923 }
924 EXPORT_SYMBOL(dump_stack);
Linux kernel - Deliverables
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