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; 269 270 oops_enter(); 271 272 raw_spin_lock_irq(&die_lock); 273 console_verbose(); 274 bust_spinlocks(1); 275 if (!user_mode(regs)) 276 report_bug(regs->ARM_pc, regs); 277 ret = __die(str, err, thread, regs); 278 279 if (regs && kexec_should_crash(thread->task)) 280 crash_kexec(regs); 281 282 bust_spinlocks(0); 283 add_taint(TAINT_DIE); 284 raw_spin_unlock_irq(&die_lock); 285 oops_exit(); 286 287 if (in_interrupt()) 288 panic("Fatal exception in interrupt"); 289 if (panic_on_oops) 290 panic("Fatal exception"); 291 if (ret != NOTIFY_STOP) 292 do_exit(SIGSEGV); 293 } 294 295 void arm_notify_die(const char *str, struct pt_regs *regs, 296 struct siginfo *info, unsigned long err, unsigned long trap) 297 { 298 if (user_mode(regs)) { 299 current->thread.error_code = err; 300 current->thread.trap_no = trap; 301 302 force_sig_info(info->si_signo, info, current); 303 } else { 304 die(str, regs, err); 305 } 306 } 307 308 #ifdef CONFIG_GENERIC_BUG 309 310 int is_valid_bugaddr(unsigned long pc) 311 { 312 #ifdef CONFIG_THUMB2_KERNEL 313 unsigned short bkpt; 314 #else 315 unsigned long bkpt; 316 #endif 317 318 if (probe_kernel_address((unsigned *)pc, bkpt)) 319 return 0; 320 321 return bkpt == BUG_INSTR_VALUE; 322 } 323 324 #endif 325 326 static LIST_HEAD(undef_hook); 327 static DEFINE_RAW_SPINLOCK(undef_lock); 328 329 void register_undef_hook(struct undef_hook *hook) 330 { 331 unsigned long flags; 332 333 raw_spin_lock_irqsave(&undef_lock, flags); 334 list_add(&hook->node, &undef_hook); 335 raw_spin_unlock_irqrestore(&undef_lock, flags); 336 } 337 338 void unregister_undef_hook(struct undef_hook *hook) 339 { 340 unsigned long flags; 341 342 raw_spin_lock_irqsave(&undef_lock, flags); 343 list_del(&hook->node); 344 raw_spin_unlock_irqrestore(&undef_lock, flags); 345 } 346 347 static int call_undef_hook(struct pt_regs *regs, unsigned int instr) 348 { 349 struct undef_hook *hook; 350 unsigned long flags; 351 int (*fn)(struct pt_regs *regs, unsigned int instr) = NULL; 352 353 raw_spin_lock_irqsave(&undef_lock, flags); 354 list_for_each_entry(hook, &undef_hook, node) 355 if ((instr & hook->instr_mask) == hook->instr_val && 356 (regs->ARM_cpsr & hook->cpsr_mask) == hook->cpsr_val) 357 fn = hook->fn; 358 raw_spin_unlock_irqrestore(&undef_lock, flags); 359 360 return fn ? fn(regs, instr) : 1; 361 } 362 363 asmlinkage void __exception do_undefinstr(struct pt_regs *regs) 364 { 365 unsigned int correction = thumb_mode(regs) ? 2 : 4; 366 unsigned int instr; 367 siginfo_t info; 368 void __user *pc; 369 370 /* 371 * According to the ARM ARM, PC is 2 or 4 bytes ahead, 372 * depending whether we're in Thumb mode or not. 373 * Correct this offset. 374 */ 375 regs->ARM_pc -= correction; 376 377 pc = (void __user *)instruction_pointer(regs); 378 379 if (processor_mode(regs) == SVC_MODE) { 380 #ifdef CONFIG_THUMB2_KERNEL 381 if (thumb_mode(regs)) { 382 instr = ((u16 *)pc)[0]; 383 if (is_wide_instruction(instr)) { 384 instr <<= 16; 385 instr |= ((u16 *)pc)[1]; 386 } 387 } else 388 #endif 389 instr = *(u32 *) pc; 390 } else if (thumb_mode(regs)) { 391 get_user(instr, (u16 __user *)pc); 392 if (is_wide_instruction(instr)) { 393 unsigned int instr2; 394 get_user(instr2, (u16 __user *)pc+1); 395 instr <<= 16; 396 instr |= instr2; 397 } 398 } else { 399 get_user(instr, (u32 __user *)pc); 400 } 401 402 if (call_undef_hook(regs, instr) == 0) 403 return; 404 405 #ifdef CONFIG_DEBUG_USER 406 if (user_debug & UDBG_UNDEFINED) { 407 printk(KERN_INFO "%s (%d): undefined instruction: pc=%p\n", 408 current->comm, task_pid_nr(current), pc); 409 dump_instr(KERN_INFO, regs); 410 } 411 #endif 412 413 info.si_signo = SIGILL; 414 info.si_errno = 0; 415 info.si_code = ILL_ILLOPC; 416 info.si_addr = pc; 417 418 arm_notify_die("Oops - undefined instruction", regs, &info, 0, 6); 419 } 420 421 asmlinkage void do_unexp_fiq (struct pt_regs *regs) 422 { 423 printk("Hmm. Unexpected FIQ received, but trying to continue\n"); 424 printk("You may have a hardware problem...\n"); 425 } 426 427 /* 428 * bad_mode handles the impossible case in the vectors. If you see one of 429 * these, then it's extremely serious, and could mean you have buggy hardware. 430 * It never returns, and never tries to sync. We hope that we can at least 431 * dump out some state information... 432 */ 433 asmlinkage void bad_mode(struct pt_regs *regs, int reason) 434 { 435 console_verbose(); 436 437 printk(KERN_CRIT "Bad mode in %s handler detected\n", handler[reason]); 438 439 die("Oops - bad mode", regs, 0); 440 local_irq_disable(); 441 panic("bad mode"); 442 } 443 444 static int bad_syscall(int n, struct pt_regs *regs) 445 { 446 struct thread_info *thread = current_thread_info(); 447 siginfo_t info; 448 449 if ((current->personality & PER_MASK) != PER_LINUX && 450 thread->exec_domain->handler) { 451 thread->exec_domain->handler(n, regs); 452 return regs->ARM_r0; 453 } 454 455 #ifdef CONFIG_DEBUG_USER 456 if (user_debug & UDBG_SYSCALL) { 457 printk(KERN_ERR "[%d] %s: obsolete system call %08x.\n", 458 task_pid_nr(current), current->comm, n); 459 dump_instr(KERN_ERR, regs); 460 } 461 #endif 462 463 info.si_signo = SIGILL; 464 info.si_errno = 0; 465 info.si_code = ILL_ILLTRP; 466 info.si_addr = (void __user *)instruction_pointer(regs) - 467 (thumb_mode(regs) ? 2 : 4); 468 469 arm_notify_die("Oops - bad syscall", regs, &info, n, 0); 470 471 return regs->ARM_r0; 472 } 473 474 static inline void 475 do_cache_op(unsigned long start, unsigned long end, int flags) 476 { 477 struct mm_struct *mm = current->active_mm; 478 struct vm_area_struct *vma; 479 480 if (end < start || flags) 481 return; 482 483 down_read(&mm->mmap_sem); 484 vma = find_vma(mm, start); 485 if (vma && vma->vm_start < end) { 486 if (start < vma->vm_start) 487 start = vma->vm_start; 488 if (end > vma->vm_end) 489 end = vma->vm_end; 490 491 flush_cache_user_range(vma, start, end); 492 } 493 up_read(&mm->mmap_sem); 494 } 495 496 /* 497 * Handle all unrecognised system calls. 498 * 0x9f0000 - 0x9fffff are some more esoteric system calls 499 */ 500 #define NR(x) ((__ARM_NR_##x) - __ARM_NR_BASE) 501 asmlinkage int arm_syscall(int no, struct pt_regs *regs) 502 { 503 struct thread_info *thread = current_thread_info(); 504 siginfo_t info; 505 506 if ((no >> 16) != (__ARM_NR_BASE>> 16)) 507 return bad_syscall(no, regs); 508 509 switch (no & 0xffff) { 510 case 0: /* branch through 0 */ 511 info.si_signo = SIGSEGV; 512 info.si_errno = 0; 513 info.si_code = SEGV_MAPERR; 514 info.si_addr = NULL; 515 516 arm_notify_die("branch through zero", regs, &info, 0, 0); 517 return 0; 518 519 case NR(breakpoint): /* SWI BREAK_POINT */ 520 regs->ARM_pc -= thumb_mode(regs) ? 2 : 4; 521 ptrace_break(current, regs); 522 return regs->ARM_r0; 523 524 /* 525 * Flush a region from virtual address 'r0' to virtual address 'r1' 526 * _exclusive_. There is no alignment requirement on either address; 527 * user space does not need to know the hardware cache layout. 528 * 529 * r2 contains flags. It should ALWAYS be passed as ZERO until it 530 * is defined to be something else. For now we ignore it, but may 531 * the fires of hell burn in your belly if you break this rule. ;) 532 * 533 * (at a later date, we may want to allow this call to not flush 534 * various aspects of the cache. Passing '0' will guarantee that 535 * everything necessary gets flushed to maintain consistency in 536 * the specified region). 537 */ 538 case NR(cacheflush): 539 do_cache_op(regs->ARM_r0, regs->ARM_r1, regs->ARM_r2); 540 return 0; 541 542 case NR(usr26): 543 if (!(elf_hwcap & HWCAP_26BIT)) 544 break; 545 regs->ARM_cpsr &= ~MODE32_BIT; 546 return regs->ARM_r0; 547 548 case NR(usr32): 549 if (!(elf_hwcap & HWCAP_26BIT)) 550 break; 551 regs->ARM_cpsr |= MODE32_BIT; 552 return regs->ARM_r0; 553 554 case NR(set_tls): 555 thread->tp_value = regs->ARM_r0; 556 if (tls_emu) 557 return 0; 558 if (has_tls_reg) { 559 asm ("mcr p15, 0, %0, c13, c0, 3" 560 : : "r" (regs->ARM_r0)); 561 } else { 562 /* 563 * User space must never try to access this directly. 564 * Expect your app to break eventually if you do so. 565 * The user helper at 0xffff0fe0 must be used instead. 566 * (see entry-armv.S for details) 567 */ 568 *((unsigned int *)0xffff0ff0) = regs->ARM_r0; 569 } 570 return 0; 571 572 #ifdef CONFIG_NEEDS_SYSCALL_FOR_CMPXCHG 573 /* 574 * Atomically store r1 in *r2 if *r2 is equal to r0 for user space. 575 * Return zero in r0 if *MEM was changed or non-zero if no exchange 576 * happened. Also set the user C flag accordingly. 577 * If access permissions have to be fixed up then non-zero is 578 * returned and the operation has to be re-attempted. 579 * 580 * *NOTE*: This is a ghost syscall private to the kernel. Only the 581 * __kuser_cmpxchg code in entry-armv.S should be aware of its 582 * existence. Don't ever use this from user code. 583 */ 584 case NR(cmpxchg): 585 for (;;) { 586 extern void do_DataAbort(unsigned long addr, unsigned int fsr, 587 struct pt_regs *regs); 588 unsigned long val; 589 unsigned long addr = regs->ARM_r2; 590 struct mm_struct *mm = current->mm; 591 pgd_t *pgd; pmd_t *pmd; pte_t *pte; 592 spinlock_t *ptl; 593 594 regs->ARM_cpsr &= ~PSR_C_BIT; 595 down_read(&mm->mmap_sem); 596 pgd = pgd_offset(mm, addr); 597 if (!pgd_present(*pgd)) 598 goto bad_access; 599 pmd = pmd_offset(pgd, addr); 600 if (!pmd_present(*pmd)) 601 goto bad_access; 602 pte = pte_offset_map_lock(mm, pmd, addr, &ptl); 603 if (!pte_present(*pte) || !pte_write(*pte) || !pte_dirty(*pte)) { 604 pte_unmap_unlock(pte, ptl); 605 goto bad_access; 606 } 607 val = *(unsigned long *)addr; 608 val -= regs->ARM_r0; 609 if (val == 0) { 610 *(unsigned long *)addr = regs->ARM_r1; 611 regs->ARM_cpsr |= PSR_C_BIT; 612 } 613 pte_unmap_unlock(pte, ptl); 614 up_read(&mm->mmap_sem); 615 return val; 616 617 bad_access: 618 up_read(&mm->mmap_sem); 619 /* simulate a write access fault */ 620 do_DataAbort(addr, 15 + (1 << 11), regs); 621 } 622 #endif 623 624 default: 625 /* Calls 9f00xx..9f07ff are defined to return -ENOSYS 626 if not implemented, rather than raising SIGILL. This 627 way the calling program can gracefully determine whether 628 a feature is supported. */ 629 if ((no & 0xffff) <= 0x7ff) 630 return -ENOSYS; 631 break; 632 } 633 #ifdef CONFIG_DEBUG_USER 634 /* 635 * experience shows that these seem to indicate that 636 * something catastrophic has happened 637 */ 638 if (user_debug & UDBG_SYSCALL) { 639 printk("[%d] %s: arm syscall %d\n", 640 task_pid_nr(current), current->comm, no); 641 dump_instr("", regs); 642 if (user_mode(regs)) { 643 __show_regs(regs); 644 c_backtrace(regs->ARM_fp, processor_mode(regs)); 645 } 646 } 647 #endif 648 info.si_signo = SIGILL; 649 info.si_errno = 0; 650 info.si_code = ILL_ILLTRP; 651 info.si_addr = (void __user *)instruction_pointer(regs) - 652 (thumb_mode(regs) ? 2 : 4); 653 654 arm_notify_die("Oops - bad syscall(2)", regs, &info, no, 0); 655 return 0; 656 } 657 658 #ifdef CONFIG_TLS_REG_EMUL 659 660 /* 661 * We might be running on an ARMv6+ processor which should have the TLS 662 * register but for some reason we can't use it, or maybe an SMP system 663 * using a pre-ARMv6 processor (there are apparently a few prototypes like 664 * that in existence) and therefore access to that register must be 665 * emulated. 666 */ 667 668 static int get_tp_trap(struct pt_regs *regs, unsigned int instr) 669 { 670 int reg = (instr >> 12) & 15; 671 if (reg == 15) 672 return 1; 673 regs->uregs[reg] = current_thread_info()->tp_value; 674 regs->ARM_pc += 4; 675 return 0; 676 } 677 678 static struct undef_hook arm_mrc_hook = { 679 .instr_mask = 0x0fff0fff, 680 .instr_val = 0x0e1d0f70, 681 .cpsr_mask = PSR_T_BIT, 682 .cpsr_val = 0, 683 .fn = get_tp_trap, 684 }; 685 686 static int __init arm_mrc_hook_init(void) 687 { 688 register_undef_hook(&arm_mrc_hook); 689 return 0; 690 } 691 692 late_initcall(arm_mrc_hook_init); 693 694 #endif 695 696 void __bad_xchg(volatile void *ptr, int size) 697 { 698 printk("xchg: bad data size: pc 0x%p, ptr 0x%p, size %d\n", 699 __builtin_return_address(0), ptr, size); 700 BUG(); 701 } 702 EXPORT_SYMBOL(__bad_xchg); 703 704 /* 705 * A data abort trap was taken, but we did not handle the instruction. 706 * Try to abort the user program, or panic if it was the kernel. 707 */ 708 asmlinkage void 709 baddataabort(int code, unsigned long instr, struct pt_regs *regs) 710 { 711 unsigned long addr = instruction_pointer(regs); 712 siginfo_t info; 713 714 #ifdef CONFIG_DEBUG_USER 715 if (user_debug & UDBG_BADABORT) { 716 printk(KERN_ERR "[%d] %s: bad data abort: code %d instr 0x%08lx\n", 717 task_pid_nr(current), current->comm, code, instr); 718 dump_instr(KERN_ERR, regs); 719 show_pte(current->mm, addr); 720 } 721 #endif 722 723 info.si_signo = SIGILL; 724 info.si_errno = 0; 725 info.si_code = ILL_ILLOPC; 726 info.si_addr = (void __user *)addr; 727 728 arm_notify_die("unknown data abort code", regs, &info, instr, 0); 729 } 730 731 void __readwrite_bug(const char *fn) 732 { 733 printk("%s called, but not implemented\n", fn); 734 BUG(); 735 } 736 EXPORT_SYMBOL(__readwrite_bug); 737 738 void __pte_error(const char *file, int line, pte_t pte) 739 { 740 printk("%s:%d: bad pte %08llx.\n", file, line, (long long)pte_val(pte)); 741 } 742 743 void __pmd_error(const char *file, int line, pmd_t pmd) 744 { 745 printk("%s:%d: bad pmd %08llx.\n", file, line, (long long)pmd_val(pmd)); 746 } 747 748 void __pgd_error(const char *file, int line, pgd_t pgd) 749 { 750 printk("%s:%d: bad pgd %08llx.\n", file, line, (long long)pgd_val(pgd)); 751 } 752 753 asmlinkage void __div0(void) 754 { 755 printk("Division by zero in kernel.\n"); 756 dump_stack(); 757 } 758 EXPORT_SYMBOL(__div0); 759 760 void abort(void) 761 { 762 BUG(); 763 764 /* if that doesn't kill us, halt */ 765 panic("Oops failed to kill thread"); 766 } 767 EXPORT_SYMBOL(abort); 768 769 void __init trap_init(void) 770 { 771 return; 772 } 773 774 static void __init kuser_get_tls_init(unsigned long vectors) 775 { 776 /* 777 * vectors + 0xfe0 = __kuser_get_tls 778 * vectors + 0xfe8 = hardware TLS instruction at 0xffff0fe8 779 */ 780 if (tls_emu || has_tls_reg) 781 memcpy((void *)vectors + 0xfe0, (void *)vectors + 0xfe8, 4); 782 } 783 784 void __init early_trap_init(void) 785 { 786 #if defined(CONFIG_CPU_USE_DOMAINS) 787 unsigned long vectors = CONFIG_VECTORS_BASE; 788 #else 789 unsigned long vectors = (unsigned long)vectors_page; 790 #endif 791 extern char __stubs_start[], __stubs_end[]; 792 extern char __vectors_start[], __vectors_end[]; 793 extern char __kuser_helper_start[], __kuser_helper_end[]; 794 int kuser_sz = __kuser_helper_end - __kuser_helper_start; 795 796 /* 797 * Copy the vectors, stubs and kuser helpers (in entry-armv.S) 798 * into the vector page, mapped at 0xffff0000, and ensure these 799 * are visible to the instruction stream. 800 */ 801 memcpy((void *)vectors, __vectors_start, __vectors_end - __vectors_start); 802 memcpy((void *)vectors + 0x200, __stubs_start, __stubs_end - __stubs_start); 803 memcpy((void *)vectors + 0x1000 - kuser_sz, __kuser_helper_start, kuser_sz); 804 805 /* 806 * Do processor specific fixups for the kuser helpers 807 */ 808 kuser_get_tls_init(vectors); 809 810 /* 811 * Copy signal return handlers into the vector page, and 812 * set sigreturn to be a pointer to these. 813 */ 814 memcpy((void *)(vectors + KERN_SIGRETURN_CODE - CONFIG_VECTORS_BASE), 815 sigreturn_codes, sizeof(sigreturn_codes)); 816 memcpy((void *)(vectors + KERN_RESTART_CODE - CONFIG_VECTORS_BASE), 817 syscall_restart_code, sizeof(syscall_restart_code)); 818 819 flush_icache_range(vectors, vectors + PAGE_SIZE); 820 modify_domain(DOMAIN_USER, DOMAIN_CLIENT); 821 } 822