1 /* 2 * linux/arch/arm/kernel/traps.c 3 * 4 * Copyright (C) 1995-2009 Russell King 5 * Fragments that appear the same as linux/arch/i386/kernel/traps.c (C) Linus Torvalds 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License version 2 as 9 * published by the Free Software Foundation. 10 * 11 * 'traps.c' handles hardware exceptions after we have saved some state in 12 * 'linux/arch/arm/lib/traps.S'. Mostly a debugging aid, but will probably 13 * kill the offending process. 14 */ 15 #include <linux/signal.h> 16 #include <linux/personality.h> 17 #include <linux/kallsyms.h> 18 #include <linux/spinlock.h> 19 #include <linux/uaccess.h> 20 #include <linux/hardirq.h> 21 #include <linux/kdebug.h> 22 #include <linux/module.h> 23 #include <linux/kexec.h> 24 #include <linux/bug.h> 25 #include <linux/delay.h> 26 #include <linux/init.h> 27 #include <linux/sched.h> 28 29 #include <linux/atomic.h> 30 #include <asm/cacheflush.h> 31 #include <asm/exception.h> 32 #include <asm/system.h> 33 #include <asm/unistd.h> 34 #include <asm/traps.h> 35 #include <asm/unwind.h> 36 #include <asm/tls.h> 37 38 #include "signal.h" 39 40 static const char *handler[]= { "prefetch abort", "data abort", "address exception", "interrupt" }; 41 42 void *vectors_page; 43 44 #ifdef CONFIG_DEBUG_USER 45 unsigned int user_debug; 46 47 static int __init user_debug_setup(char *str) 48 { 49 get_option(&str, &user_debug); 50 return 1; 51 } 52 __setup("user_debug=", user_debug_setup); 53 #endif 54 55 static void dump_mem(const char *, const char *, unsigned long, unsigned long); 56 57 void dump_backtrace_entry(unsigned long where, unsigned long from, unsigned long frame) 58 { 59 #ifdef CONFIG_KALLSYMS 60 printk("[<%08lx>] (%pS) from [<%08lx>] (%pS)\n", where, (void *)where, from, (void *)from); 61 #else 62 printk("Function entered at [<%08lx>] from [<%08lx>]\n", where, from); 63 #endif 64 65 if (in_exception_text(where)) 66 dump_mem("", "Exception stack", frame + 4, frame + 4 + sizeof(struct pt_regs)); 67 } 68 69 #ifndef CONFIG_ARM_UNWIND 70 /* 71 * Stack pointers should always be within the kernels view of 72 * physical memory. If it is not there, then we can't dump 73 * out any information relating to the stack. 74 */ 75 static int verify_stack(unsigned long sp) 76 { 77 if (sp < PAGE_OFFSET || 78 (sp > (unsigned long)high_memory && high_memory != NULL)) 79 return -EFAULT; 80 81 return 0; 82 } 83 #endif 84 85 /* 86 * Dump out the contents of some memory nicely... 87 */ 88 static void dump_mem(const char *lvl, const char *str, unsigned long bottom, 89 unsigned long top) 90 { 91 unsigned long first; 92 mm_segment_t fs; 93 int i; 94 95 /* 96 * We need to switch to kernel mode so that we can use __get_user 97 * to safely read from kernel space. Note that we now dump the 98 * code first, just in case the backtrace kills us. 99 */ 100 fs = get_fs(); 101 set_fs(KERNEL_DS); 102 103 printk("%s%s(0x%08lx to 0x%08lx)\n", lvl, str, bottom, top); 104 105 for (first = bottom & ~31; first < top; first += 32) { 106 unsigned long p; 107 char str[sizeof(" 12345678") * 8 + 1]; 108 109 memset(str, ' ', sizeof(str)); 110 str[sizeof(str) - 1] = '\0'; 111 112 for (p = first, i = 0; i < 8 && p < top; i++, p += 4) { 113 if (p >= bottom && p < top) { 114 unsigned long val; 115 if (__get_user(val, (unsigned long *)p) == 0) 116 sprintf(str + i * 9, " %08lx", val); 117 else 118 sprintf(str + i * 9, " ????????"); 119 } 120 } 121 printk("%s%04lx:%s\n", lvl, first & 0xffff, str); 122 } 123 124 set_fs(fs); 125 } 126 127 static void dump_instr(const char *lvl, struct pt_regs *regs) 128 { 129 unsigned long addr = instruction_pointer(regs); 130 const int thumb = thumb_mode(regs); 131 const int width = thumb ? 4 : 8; 132 mm_segment_t fs; 133 char str[sizeof("00000000 ") * 5 + 2 + 1], *p = str; 134 int i; 135 136 /* 137 * We need to switch to kernel mode so that we can use __get_user 138 * to safely read from kernel space. Note that we now dump the 139 * code first, just in case the backtrace kills us. 140 */ 141 fs = get_fs(); 142 set_fs(KERNEL_DS); 143 144 for (i = -4; i < 1 + !!thumb; i++) { 145 unsigned int val, bad; 146 147 if (thumb) 148 bad = __get_user(val, &((u16 *)addr)[i]); 149 else 150 bad = __get_user(val, &((u32 *)addr)[i]); 151 152 if (!bad) 153 p += sprintf(p, i == 0 ? "(%0*x) " : "%0*x ", 154 width, val); 155 else { 156 p += sprintf(p, "bad PC value"); 157 break; 158 } 159 } 160 printk("%sCode: %s\n", lvl, str); 161 162 set_fs(fs); 163 } 164 165 #ifdef CONFIG_ARM_UNWIND 166 static inline void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk) 167 { 168 unwind_backtrace(regs, tsk); 169 } 170 #else 171 static void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk) 172 { 173 unsigned int fp, mode; 174 int ok = 1; 175 176 printk("Backtrace: "); 177 178 if (!tsk) 179 tsk = current; 180 181 if (regs) { 182 fp = regs->ARM_fp; 183 mode = processor_mode(regs); 184 } else if (tsk != current) { 185 fp = thread_saved_fp(tsk); 186 mode = 0x10; 187 } else { 188 asm("mov %0, fp" : "=r" (fp) : : "cc"); 189 mode = 0x10; 190 } 191 192 if (!fp) { 193 printk("no frame pointer"); 194 ok = 0; 195 } else if (verify_stack(fp)) { 196 printk("invalid frame pointer 0x%08x", fp); 197 ok = 0; 198 } else if (fp < (unsigned long)end_of_stack(tsk)) 199 printk("frame pointer underflow"); 200 printk("\n"); 201 202 if (ok) 203 c_backtrace(fp, mode); 204 } 205 #endif 206 207 void dump_stack(void) 208 { 209 dump_backtrace(NULL, NULL); 210 } 211 212 EXPORT_SYMBOL(dump_stack); 213 214 void show_stack(struct task_struct *tsk, unsigned long *sp) 215 { 216 dump_backtrace(NULL, tsk); 217 barrier(); 218 } 219 220 #ifdef CONFIG_PREEMPT 221 #define S_PREEMPT " PREEMPT" 222 #else 223 #define S_PREEMPT "" 224 #endif 225 #ifdef CONFIG_SMP 226 #define S_SMP " SMP" 227 #else 228 #define S_SMP "" 229 #endif 230 231 static int __die(const char *str, int err, struct thread_info *thread, struct pt_regs *regs) 232 { 233 struct task_struct *tsk = thread->task; 234 static int die_counter; 235 int ret; 236 237 printk(KERN_EMERG "Internal error: %s: %x [#%d]" S_PREEMPT S_SMP "\n", 238 str, err, ++die_counter); 239 240 /* trap and error numbers are mostly meaningless on ARM */ 241 ret = notify_die(DIE_OOPS, str, regs, err, tsk->thread.trap_no, SIGSEGV); 242 if (ret == NOTIFY_STOP) 243 return ret; 244 245 print_modules(); 246 __show_regs(regs); 247 printk(KERN_EMERG "Process %.*s (pid: %d, stack limit = 0x%p)\n", 248 TASK_COMM_LEN, tsk->comm, task_pid_nr(tsk), thread + 1); 249 250 if (!user_mode(regs) || in_interrupt()) { 251 dump_mem(KERN_EMERG, "Stack: ", regs->ARM_sp, 252 THREAD_SIZE + (unsigned long)task_stack_page(tsk)); 253 dump_backtrace(regs, tsk); 254 dump_instr(KERN_EMERG, regs); 255 } 256 257 return ret; 258 } 259 260 static DEFINE_RAW_SPINLOCK(die_lock); 261 262 /* 263 * This function is protected against re-entrancy. 264 */ 265 void die(const char *str, struct pt_regs *regs, int err) 266 { 267 struct thread_info *thread = current_thread_info(); 268 int ret; 269 enum bug_trap_type bug_type = BUG_TRAP_TYPE_NONE; 270 271 oops_enter(); 272 273 raw_spin_lock_irq(&die_lock); 274 console_verbose(); 275 bust_spinlocks(1); 276 if (!user_mode(regs)) 277 bug_type = report_bug(regs->ARM_pc, regs); 278 if (bug_type != BUG_TRAP_TYPE_NONE) 279 str = "Oops - BUG"; 280 ret = __die(str, err, thread, regs); 281 282 if (regs && kexec_should_crash(thread->task)) 283 crash_kexec(regs); 284 285 bust_spinlocks(0); 286 add_taint(TAINT_DIE); 287 raw_spin_unlock_irq(&die_lock); 288 oops_exit(); 289 290 if (in_interrupt()) 291 panic("Fatal exception in interrupt"); 292 if (panic_on_oops) 293 panic("Fatal exception"); 294 if (ret != NOTIFY_STOP) 295 do_exit(SIGSEGV); 296 } 297 298 void arm_notify_die(const char *str, struct pt_regs *regs, 299 struct siginfo *info, unsigned long err, unsigned long trap) 300 { 301 if (user_mode(regs)) { 302 current->thread.error_code = err; 303 current->thread.trap_no = trap; 304 305 force_sig_info(info->si_signo, info, current); 306 } else { 307 die(str, regs, err); 308 } 309 } 310 311 #ifdef CONFIG_GENERIC_BUG 312 313 int is_valid_bugaddr(unsigned long pc) 314 { 315 #ifdef CONFIG_THUMB2_KERNEL 316 unsigned short bkpt; 317 #else 318 unsigned long bkpt; 319 #endif 320 321 if (probe_kernel_address((unsigned *)pc, bkpt)) 322 return 0; 323 324 return bkpt == BUG_INSTR_VALUE; 325 } 326 327 #endif 328 329 static LIST_HEAD(undef_hook); 330 static DEFINE_RAW_SPINLOCK(undef_lock); 331 332 void register_undef_hook(struct undef_hook *hook) 333 { 334 unsigned long flags; 335 336 raw_spin_lock_irqsave(&undef_lock, flags); 337 list_add(&hook->node, &undef_hook); 338 raw_spin_unlock_irqrestore(&undef_lock, flags); 339 } 340 341 void unregister_undef_hook(struct undef_hook *hook) 342 { 343 unsigned long flags; 344 345 raw_spin_lock_irqsave(&undef_lock, flags); 346 list_del(&hook->node); 347 raw_spin_unlock_irqrestore(&undef_lock, flags); 348 } 349 350 static int call_undef_hook(struct pt_regs *regs, unsigned int instr) 351 { 352 struct undef_hook *hook; 353 unsigned long flags; 354 int (*fn)(struct pt_regs *regs, unsigned int instr) = NULL; 355 356 raw_spin_lock_irqsave(&undef_lock, flags); 357 list_for_each_entry(hook, &undef_hook, node) 358 if ((instr & hook->instr_mask) == hook->instr_val && 359 (regs->ARM_cpsr & hook->cpsr_mask) == hook->cpsr_val) 360 fn = hook->fn; 361 raw_spin_unlock_irqrestore(&undef_lock, flags); 362 363 return fn ? fn(regs, instr) : 1; 364 } 365 366 asmlinkage void __exception do_undefinstr(struct pt_regs *regs) 367 { 368 unsigned int correction = thumb_mode(regs) ? 2 : 4; 369 unsigned int instr; 370 siginfo_t info; 371 void __user *pc; 372 373 /* 374 * According to the ARM ARM, PC is 2 or 4 bytes ahead, 375 * depending whether we're in Thumb mode or not. 376 * Correct this offset. 377 */ 378 regs->ARM_pc -= correction; 379 380 pc = (void __user *)instruction_pointer(regs); 381 382 if (processor_mode(regs) == SVC_MODE) { 383 #ifdef CONFIG_THUMB2_KERNEL 384 if (thumb_mode(regs)) { 385 instr = ((u16 *)pc)[0]; 386 if (is_wide_instruction(instr)) { 387 instr <<= 16; 388 instr |= ((u16 *)pc)[1]; 389 } 390 } else 391 #endif 392 instr = *(u32 *) pc; 393 } else if (thumb_mode(regs)) { 394 get_user(instr, (u16 __user *)pc); 395 if (is_wide_instruction(instr)) { 396 unsigned int instr2; 397 get_user(instr2, (u16 __user *)pc+1); 398 instr <<= 16; 399 instr |= instr2; 400 } 401 } else { 402 get_user(instr, (u32 __user *)pc); 403 } 404 405 if (call_undef_hook(regs, instr) == 0) 406 return; 407 408 #ifdef CONFIG_DEBUG_USER 409 if (user_debug & UDBG_UNDEFINED) { 410 printk(KERN_INFO "%s (%d): undefined instruction: pc=%p\n", 411 current->comm, task_pid_nr(current), pc); 412 dump_instr(KERN_INFO, regs); 413 } 414 #endif 415 416 info.si_signo = SIGILL; 417 info.si_errno = 0; 418 info.si_code = ILL_ILLOPC; 419 info.si_addr = pc; 420 421 arm_notify_die("Oops - undefined instruction", regs, &info, 0, 6); 422 } 423 424 asmlinkage void do_unexp_fiq (struct pt_regs *regs) 425 { 426 printk("Hmm. Unexpected FIQ received, but trying to continue\n"); 427 printk("You may have a hardware problem...\n"); 428 } 429 430 /* 431 * bad_mode handles the impossible case in the vectors. If you see one of 432 * these, then it's extremely serious, and could mean you have buggy hardware. 433 * It never returns, and never tries to sync. We hope that we can at least 434 * dump out some state information... 435 */ 436 asmlinkage void bad_mode(struct pt_regs *regs, int reason) 437 { 438 console_verbose(); 439 440 printk(KERN_CRIT "Bad mode in %s handler detected\n", handler[reason]); 441 442 die("Oops - bad mode", regs, 0); 443 local_irq_disable(); 444 panic("bad mode"); 445 } 446 447 static int bad_syscall(int n, struct pt_regs *regs) 448 { 449 struct thread_info *thread = current_thread_info(); 450 siginfo_t info; 451 452 if ((current->personality & PER_MASK) != PER_LINUX && 453 thread->exec_domain->handler) { 454 thread->exec_domain->handler(n, regs); 455 return regs->ARM_r0; 456 } 457 458 #ifdef CONFIG_DEBUG_USER 459 if (user_debug & UDBG_SYSCALL) { 460 printk(KERN_ERR "[%d] %s: obsolete system call %08x.\n", 461 task_pid_nr(current), current->comm, n); 462 dump_instr(KERN_ERR, regs); 463 } 464 #endif 465 466 info.si_signo = SIGILL; 467 info.si_errno = 0; 468 info.si_code = ILL_ILLTRP; 469 info.si_addr = (void __user *)instruction_pointer(regs) - 470 (thumb_mode(regs) ? 2 : 4); 471 472 arm_notify_die("Oops - bad syscall", regs, &info, n, 0); 473 474 return regs->ARM_r0; 475 } 476 477 static inline void 478 do_cache_op(unsigned long start, unsigned long end, int flags) 479 { 480 struct mm_struct *mm = current->active_mm; 481 struct vm_area_struct *vma; 482 483 if (end < start || flags) 484 return; 485 486 down_read(&mm->mmap_sem); 487 vma = find_vma(mm, start); 488 if (vma && vma->vm_start < end) { 489 if (start < vma->vm_start) 490 start = vma->vm_start; 491 if (end > vma->vm_end) 492 end = vma->vm_end; 493 494 flush_cache_user_range(vma, start, end); 495 } 496 up_read(&mm->mmap_sem); 497 } 498 499 /* 500 * Handle all unrecognised system calls. 501 * 0x9f0000 - 0x9fffff are some more esoteric system calls 502 */ 503 #define NR(x) ((__ARM_NR_##x) - __ARM_NR_BASE) 504 asmlinkage int arm_syscall(int no, struct pt_regs *regs) 505 { 506 struct thread_info *thread = current_thread_info(); 507 siginfo_t info; 508 509 if ((no >> 16) != (__ARM_NR_BASE>> 16)) 510 return bad_syscall(no, regs); 511 512 switch (no & 0xffff) { 513 case 0: /* branch through 0 */ 514 info.si_signo = SIGSEGV; 515 info.si_errno = 0; 516 info.si_code = SEGV_MAPERR; 517 info.si_addr = NULL; 518 519 arm_notify_die("branch through zero", regs, &info, 0, 0); 520 return 0; 521 522 case NR(breakpoint): /* SWI BREAK_POINT */ 523 regs->ARM_pc -= thumb_mode(regs) ? 2 : 4; 524 ptrace_break(current, regs); 525 return regs->ARM_r0; 526 527 /* 528 * Flush a region from virtual address 'r0' to virtual address 'r1' 529 * _exclusive_. There is no alignment requirement on either address; 530 * user space does not need to know the hardware cache layout. 531 * 532 * r2 contains flags. It should ALWAYS be passed as ZERO until it 533 * is defined to be something else. For now we ignore it, but may 534 * the fires of hell burn in your belly if you break this rule. ;) 535 * 536 * (at a later date, we may want to allow this call to not flush 537 * various aspects of the cache. Passing '0' will guarantee that 538 * everything necessary gets flushed to maintain consistency in 539 * the specified region). 540 */ 541 case NR(cacheflush): 542 do_cache_op(regs->ARM_r0, regs->ARM_r1, regs->ARM_r2); 543 return 0; 544 545 case NR(usr26): 546 if (!(elf_hwcap & HWCAP_26BIT)) 547 break; 548 regs->ARM_cpsr &= ~MODE32_BIT; 549 return regs->ARM_r0; 550 551 case NR(usr32): 552 if (!(elf_hwcap & HWCAP_26BIT)) 553 break; 554 regs->ARM_cpsr |= MODE32_BIT; 555 return regs->ARM_r0; 556 557 case NR(set_tls): 558 thread->tp_value = regs->ARM_r0; 559 if (tls_emu) 560 return 0; 561 if (has_tls_reg) { 562 asm ("mcr p15, 0, %0, c13, c0, 3" 563 : : "r" (regs->ARM_r0)); 564 } else { 565 /* 566 * User space must never try to access this directly. 567 * Expect your app to break eventually if you do so. 568 * The user helper at 0xffff0fe0 must be used instead. 569 * (see entry-armv.S for details) 570 */ 571 *((unsigned int *)0xffff0ff0) = regs->ARM_r0; 572 } 573 return 0; 574 575 #ifdef CONFIG_NEEDS_SYSCALL_FOR_CMPXCHG 576 /* 577 * Atomically store r1 in *r2 if *r2 is equal to r0 for user space. 578 * Return zero in r0 if *MEM was changed or non-zero if no exchange 579 * happened. Also set the user C flag accordingly. 580 * If access permissions have to be fixed up then non-zero is 581 * returned and the operation has to be re-attempted. 582 * 583 * *NOTE*: This is a ghost syscall private to the kernel. Only the 584 * __kuser_cmpxchg code in entry-armv.S should be aware of its 585 * existence. Don't ever use this from user code. 586 */ 587 case NR(cmpxchg): 588 for (;;) { 589 extern void do_DataAbort(unsigned long addr, unsigned int fsr, 590 struct pt_regs *regs); 591 unsigned long val; 592 unsigned long addr = regs->ARM_r2; 593 struct mm_struct *mm = current->mm; 594 pgd_t *pgd; pmd_t *pmd; pte_t *pte; 595 spinlock_t *ptl; 596 597 regs->ARM_cpsr &= ~PSR_C_BIT; 598 down_read(&mm->mmap_sem); 599 pgd = pgd_offset(mm, addr); 600 if (!pgd_present(*pgd)) 601 goto bad_access; 602 pmd = pmd_offset(pgd, addr); 603 if (!pmd_present(*pmd)) 604 goto bad_access; 605 pte = pte_offset_map_lock(mm, pmd, addr, &ptl); 606 if (!pte_present(*pte) || !pte_write(*pte) || !pte_dirty(*pte)) { 607 pte_unmap_unlock(pte, ptl); 608 goto bad_access; 609 } 610 val = *(unsigned long *)addr; 611 val -= regs->ARM_r0; 612 if (val == 0) { 613 *(unsigned long *)addr = regs->ARM_r1; 614 regs->ARM_cpsr |= PSR_C_BIT; 615 } 616 pte_unmap_unlock(pte, ptl); 617 up_read(&mm->mmap_sem); 618 return val; 619 620 bad_access: 621 up_read(&mm->mmap_sem); 622 /* simulate a write access fault */ 623 do_DataAbort(addr, 15 + (1 << 11), regs); 624 } 625 #endif 626 627 default: 628 /* Calls 9f00xx..9f07ff are defined to return -ENOSYS 629 if not implemented, rather than raising SIGILL. This 630 way the calling program can gracefully determine whether 631 a feature is supported. */ 632 if ((no & 0xffff) <= 0x7ff) 633 return -ENOSYS; 634 break; 635 } 636 #ifdef CONFIG_DEBUG_USER 637 /* 638 * experience shows that these seem to indicate that 639 * something catastrophic has happened 640 */ 641 if (user_debug & UDBG_SYSCALL) { 642 printk("[%d] %s: arm syscall %d\n", 643 task_pid_nr(current), current->comm, no); 644 dump_instr("", regs); 645 if (user_mode(regs)) { 646 __show_regs(regs); 647 c_backtrace(regs->ARM_fp, processor_mode(regs)); 648 } 649 } 650 #endif 651 info.si_signo = SIGILL; 652 info.si_errno = 0; 653 info.si_code = ILL_ILLTRP; 654 info.si_addr = (void __user *)instruction_pointer(regs) - 655 (thumb_mode(regs) ? 2 : 4); 656 657 arm_notify_die("Oops - bad syscall(2)", regs, &info, no, 0); 658 return 0; 659 } 660 661 #ifdef CONFIG_TLS_REG_EMUL 662 663 /* 664 * We might be running on an ARMv6+ processor which should have the TLS 665 * register but for some reason we can't use it, or maybe an SMP system 666 * using a pre-ARMv6 processor (there are apparently a few prototypes like 667 * that in existence) and therefore access to that register must be 668 * emulated. 669 */ 670 671 static int get_tp_trap(struct pt_regs *regs, unsigned int instr) 672 { 673 int reg = (instr >> 12) & 15; 674 if (reg == 15) 675 return 1; 676 regs->uregs[reg] = current_thread_info()->tp_value; 677 regs->ARM_pc += 4; 678 return 0; 679 } 680 681 static struct undef_hook arm_mrc_hook = { 682 .instr_mask = 0x0fff0fff, 683 .instr_val = 0x0e1d0f70, 684 .cpsr_mask = PSR_T_BIT, 685 .cpsr_val = 0, 686 .fn = get_tp_trap, 687 }; 688 689 static int __init arm_mrc_hook_init(void) 690 { 691 register_undef_hook(&arm_mrc_hook); 692 return 0; 693 } 694 695 late_initcall(arm_mrc_hook_init); 696 697 #endif 698 699 void __bad_xchg(volatile void *ptr, int size) 700 { 701 printk("xchg: bad data size: pc 0x%p, ptr 0x%p, size %d\n", 702 __builtin_return_address(0), ptr, size); 703 BUG(); 704 } 705 EXPORT_SYMBOL(__bad_xchg); 706 707 /* 708 * A data abort trap was taken, but we did not handle the instruction. 709 * Try to abort the user program, or panic if it was the kernel. 710 */ 711 asmlinkage void 712 baddataabort(int code, unsigned long instr, struct pt_regs *regs) 713 { 714 unsigned long addr = instruction_pointer(regs); 715 siginfo_t info; 716 717 #ifdef CONFIG_DEBUG_USER 718 if (user_debug & UDBG_BADABORT) { 719 printk(KERN_ERR "[%d] %s: bad data abort: code %d instr 0x%08lx\n", 720 task_pid_nr(current), current->comm, code, instr); 721 dump_instr(KERN_ERR, regs); 722 show_pte(current->mm, addr); 723 } 724 #endif 725 726 info.si_signo = SIGILL; 727 info.si_errno = 0; 728 info.si_code = ILL_ILLOPC; 729 info.si_addr = (void __user *)addr; 730 731 arm_notify_die("unknown data abort code", regs, &info, instr, 0); 732 } 733 734 void __readwrite_bug(const char *fn) 735 { 736 printk("%s called, but not implemented\n", fn); 737 BUG(); 738 } 739 EXPORT_SYMBOL(__readwrite_bug); 740 741 void __pte_error(const char *file, int line, pte_t pte) 742 { 743 printk("%s:%d: bad pte %08llx.\n", file, line, (long long)pte_val(pte)); 744 } 745 746 void __pmd_error(const char *file, int line, pmd_t pmd) 747 { 748 printk("%s:%d: bad pmd %08llx.\n", file, line, (long long)pmd_val(pmd)); 749 } 750 751 void __pgd_error(const char *file, int line, pgd_t pgd) 752 { 753 printk("%s:%d: bad pgd %08llx.\n", file, line, (long long)pgd_val(pgd)); 754 } 755 756 asmlinkage void __div0(void) 757 { 758 printk("Division by zero in kernel.\n"); 759 dump_stack(); 760 } 761 EXPORT_SYMBOL(__div0); 762 763 void abort(void) 764 { 765 BUG(); 766 767 /* if that doesn't kill us, halt */ 768 panic("Oops failed to kill thread"); 769 } 770 EXPORT_SYMBOL(abort); 771 772 void __init trap_init(void) 773 { 774 return; 775 } 776 777 static void __init kuser_get_tls_init(unsigned long vectors) 778 { 779 /* 780 * vectors + 0xfe0 = __kuser_get_tls 781 * vectors + 0xfe8 = hardware TLS instruction at 0xffff0fe8 782 */ 783 if (tls_emu || has_tls_reg) 784 memcpy((void *)vectors + 0xfe0, (void *)vectors + 0xfe8, 4); 785 } 786 787 void __init early_trap_init(void) 788 { 789 #if defined(CONFIG_CPU_USE_DOMAINS) 790 unsigned long vectors = CONFIG_VECTORS_BASE; 791 #else 792 unsigned long vectors = (unsigned long)vectors_page; 793 #endif 794 extern char __stubs_start[], __stubs_end[]; 795 extern char __vectors_start[], __vectors_end[]; 796 extern char __kuser_helper_start[], __kuser_helper_end[]; 797 int kuser_sz = __kuser_helper_end - __kuser_helper_start; 798 799 /* 800 * Copy the vectors, stubs and kuser helpers (in entry-armv.S) 801 * into the vector page, mapped at 0xffff0000, and ensure these 802 * are visible to the instruction stream. 803 */ 804 memcpy((void *)vectors, __vectors_start, __vectors_end - __vectors_start); 805 memcpy((void *)vectors + 0x200, __stubs_start, __stubs_end - __stubs_start); 806 memcpy((void *)vectors + 0x1000 - kuser_sz, __kuser_helper_start, kuser_sz); 807 808 /* 809 * Do processor specific fixups for the kuser helpers 810 */ 811 kuser_get_tls_init(vectors); 812 813 /* 814 * Copy signal return handlers into the vector page, and 815 * set sigreturn to be a pointer to these. 816 */ 817 memcpy((void *)(vectors + KERN_SIGRETURN_CODE - CONFIG_VECTORS_BASE), 818 sigreturn_codes, sizeof(sigreturn_codes)); 819 memcpy((void *)(vectors + KERN_RESTART_CODE - CONFIG_VECTORS_BASE), 820 syscall_restart_code, sizeof(syscall_restart_code)); 821 822 flush_icache_range(vectors, vectors + PAGE_SIZE); 823 modify_domain(DOMAIN_USER, DOMAIN_CLIENT); 824 } 825