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 = ®s->regs[index]; 165 166 index = (instruction>>4)&15; /* 0x00F0 */ 167 rm = ®s->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*) ®s->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*) ®s->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 extern asmlinkage void address_error_handler(unsigned long r4, unsigned long r5, 841 unsigned long r6, unsigned long r7, 842 struct pt_regs __regs); 843 844 void __init trap_init(void) 845 { 846 set_exception_table_vec(TRAP_RESERVED_INST, do_reserved_inst); 847 set_exception_table_vec(TRAP_ILLEGAL_SLOT_INST, do_illegal_slot_inst); 848 849 #if defined(CONFIG_CPU_SH4) && !defined(CONFIG_SH_FPU) || \ 850 defined(CONFIG_SH_FPU_EMU) 851 /* 852 * For SH-4 lacking an FPU, treat floating point instructions as 853 * reserved. They'll be handled in the math-emu case, or faulted on 854 * otherwise. 855 */ 856 set_exception_table_evt(0x800, do_reserved_inst); 857 set_exception_table_evt(0x820, do_illegal_slot_inst); 858 #elif defined(CONFIG_SH_FPU) 859 #ifdef CONFIG_CPU_SUBTYPE_SHX3 860 set_exception_table_evt(0xd80, do_fpu_state_restore); 861 set_exception_table_evt(0xda0, do_fpu_state_restore); 862 #else 863 set_exception_table_evt(0x800, do_fpu_state_restore); 864 set_exception_table_evt(0x820, do_fpu_state_restore); 865 #endif 866 #endif 867 868 #ifdef CONFIG_CPU_SH2 869 set_exception_table_vec(TRAP_ADDRESS_ERROR, address_error_handler); 870 #endif 871 #ifdef CONFIG_CPU_SH2A 872 set_exception_table_vec(TRAP_DIVZERO_ERROR, do_divide_error); 873 set_exception_table_vec(TRAP_DIVOVF_ERROR, do_divide_error); 874 #endif 875 876 /* Setup VBR for boot cpu */ 877 per_cpu_trap_init(); 878 } 879 880 #ifdef CONFIG_BUG 881 void handle_BUG(struct pt_regs *regs) 882 { 883 enum bug_trap_type tt; 884 tt = report_bug(regs->pc, regs); 885 if (tt == BUG_TRAP_TYPE_WARN) { 886 regs->pc += 2; 887 return; 888 } 889 890 die("Kernel BUG", regs, TRAPA_BUG_OPCODE & 0xff); 891 } 892 893 int is_valid_bugaddr(unsigned long addr) 894 { 895 return addr >= PAGE_OFFSET; 896 } 897 #endif 898 899 void show_trace(struct task_struct *tsk, unsigned long *sp, 900 struct pt_regs *regs) 901 { 902 unsigned long addr; 903 904 if (regs && user_mode(regs)) 905 return; 906 907 printk("\nCall trace: "); 908 #ifdef CONFIG_KALLSYMS 909 printk("\n"); 910 #endif 911 912 while (!kstack_end(sp)) { 913 addr = *sp++; 914 if (kernel_text_address(addr)) 915 print_ip_sym(addr); 916 } 917 918 printk("\n"); 919 920 if (!tsk) 921 tsk = current; 922 923 debug_show_held_locks(tsk); 924 } 925 926 void show_stack(struct task_struct *tsk, unsigned long *sp) 927 { 928 unsigned long stack; 929 930 if (!tsk) 931 tsk = current; 932 if (tsk == current) 933 sp = (unsigned long *)current_stack_pointer; 934 else 935 sp = (unsigned long *)tsk->thread.sp; 936 937 stack = (unsigned long)sp; 938 dump_mem("Stack: ", stack, THREAD_SIZE + 939 (unsigned long)task_stack_page(tsk)); 940 show_trace(tsk, sp, NULL); 941 } 942 943 void dump_stack(void) 944 { 945 show_stack(NULL, NULL); 946 } 947 EXPORT_SYMBOL(dump_stack); 948