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/delay.h> 25#include <linux/init.h> 26 27#include <asm/atomic.h> 28#include <asm/cacheflush.h> 29#include <asm/system.h> 30#include <asm/unistd.h> 31#include <asm/traps.h> 32#include <asm/unwind.h> 33#include <asm/tls.h> 34 35#include "ptrace.h" 36#include "signal.h" 37 38static const char *handler[]= { "prefetch abort", "data abort", "address exception", "interrupt" }; 39 40#ifdef CONFIG_DEBUG_USER 41unsigned int user_debug; 42 43static int __init user_debug_setup(char *str) 44{ 45 get_option(&str, &user_debug); 46 return 1; 47} 48__setup("user_debug=", user_debug_setup); 49#endif 50 51static void dump_mem(const char *, const char *, unsigned long, unsigned long); 52 53void dump_backtrace_entry(unsigned long where, unsigned long from, unsigned long frame) 54{ 55#ifdef CONFIG_KALLSYMS 56 char sym1[KSYM_SYMBOL_LEN], sym2[KSYM_SYMBOL_LEN]; 57 sprint_symbol(sym1, where); 58 sprint_symbol(sym2, from); 59 printk("[<%08lx>] (%s) from [<%08lx>] (%s)\n", where, sym1, from, sym2); 60#else 61 printk("Function entered at [<%08lx>] from [<%08lx>]\n", where, from); 62#endif 63 64 if (in_exception_text(where)) 65 dump_mem("", "Exception stack", frame + 4, frame + 4 + sizeof(struct pt_regs)); 66} 67 68#ifndef CONFIG_ARM_UNWIND 69/* 70 * Stack pointers should always be within the kernels view of 71 * physical memory. If it is not there, then we can't dump 72 * out any information relating to the stack. 73 */ 74static int verify_stack(unsigned long sp) 75{ 76 if (sp < PAGE_OFFSET || 77 (sp > (unsigned long)high_memory && high_memory != NULL)) 78 return -EFAULT; 79 80 return 0; 81} 82#endif 83 84/* 85 * Dump out the contents of some memory nicely... 86 */ 87static void dump_mem(const char *lvl, const char *str, unsigned long bottom, 88 unsigned long top) 89{ 90 unsigned long first; 91 mm_segment_t fs; 92 int i; 93 94 /* 95 * We need to switch to kernel mode so that we can use __get_user 96 * to safely read from kernel space. Note that we now dump the 97 * code first, just in case the backtrace kills us. 98 */ 99 fs = get_fs(); 100 set_fs(KERNEL_DS); 101 102 printk("%s%s(0x%08lx to 0x%08lx)\n", lvl, str, bottom, top); 103 104 for (first = bottom & ~31; first < top; first += 32) { 105 unsigned long p; 106 char str[sizeof(" 12345678") * 8 + 1]; 107 108 memset(str, ' ', sizeof(str)); 109 str[sizeof(str) - 1] = '\0'; 110 111 for (p = first, i = 0; i < 8 && p < top; i++, p += 4) { 112 if (p >= bottom && p < top) { 113 unsigned long val; 114 if (__get_user(val, (unsigned long *)p) == 0) 115 sprintf(str + i * 9, " %08lx", val); 116 else 117 sprintf(str + i * 9, " ????????"); 118 } 119 } 120 printk("%s%04lx:%s\n", lvl, first & 0xffff, str); 121 } 122 123 set_fs(fs); 124} 125 126static void dump_instr(const char *lvl, struct pt_regs *regs) 127{ 128 unsigned long addr = instruction_pointer(regs); 129 const int thumb = thumb_mode(regs); 130 const int width = thumb ? 4 : 8; 131 mm_segment_t fs; 132 char str[sizeof("00000000 ") * 5 + 2 + 1], *p = str; 133 int i; 134 135 /* 136 * We need to switch to kernel mode so that we can use __get_user 137 * to safely read from kernel space. Note that we now dump the 138 * code first, just in case the backtrace kills us. 139 */ 140 fs = get_fs(); 141 set_fs(KERNEL_DS); 142 143 for (i = -4; i < 1; i++) { 144 unsigned int val, bad; 145 146 if (thumb) 147 bad = __get_user(val, &((u16 *)addr)[i]); 148 else 149 bad = __get_user(val, &((u32 *)addr)[i]); 150 151 if (!bad) 152 p += sprintf(p, i == 0 ? "(%0*x) " : "%0*x ", 153 width, val); 154 else { 155 p += sprintf(p, "bad PC value"); 156 break; 157 } 158 } 159 printk("%sCode: %s\n", lvl, str); 160 161 set_fs(fs); 162} 163 164#ifdef CONFIG_ARM_UNWIND 165static inline void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk) 166{ 167 unwind_backtrace(regs, tsk); 168} 169#else 170static void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk) 171{ 172 unsigned int fp, mode; 173 int ok = 1; 174 175 printk("Backtrace: "); 176 177 if (!tsk) 178 tsk = current; 179 180 if (regs) { 181 fp = regs->ARM_fp; 182 mode = processor_mode(regs); 183 } else if (tsk != current) { 184 fp = thread_saved_fp(tsk); 185 mode = 0x10; 186 } else { 187 asm("mov %0, fp" : "=r" (fp) : : "cc"); 188 mode = 0x10; 189 } 190 191 if (!fp) { 192 printk("no frame pointer"); 193 ok = 0; 194 } else if (verify_stack(fp)) { 195 printk("invalid frame pointer 0x%08x", fp); 196 ok = 0; 197 } else if (fp < (unsigned long)end_of_stack(tsk)) 198 printk("frame pointer underflow"); 199 printk("\n"); 200 201 if (ok) 202 c_backtrace(fp, mode); 203} 204#endif 205 206void dump_stack(void) 207{ 208 dump_backtrace(NULL, NULL); 209} 210 211EXPORT_SYMBOL(dump_stack); 212 213void show_stack(struct task_struct *tsk, unsigned long *sp) 214{ 215 dump_backtrace(NULL, tsk); 216 barrier(); 217} 218 219#ifdef CONFIG_PREEMPT 220#define S_PREEMPT " PREEMPT" 221#else 222#define S_PREEMPT "" 223#endif 224#ifdef CONFIG_SMP 225#define S_SMP " SMP" 226#else 227#define S_SMP "" 228#endif 229 230static int __die(const char *str, int err, struct thread_info *thread, struct pt_regs *regs) 231{ 232 struct task_struct *tsk = thread->task; 233 static int die_counter; 234 int ret; 235 236 printk(KERN_EMERG "Internal error: %s: %x [#%d]" S_PREEMPT S_SMP "\n", 237 str, err, ++die_counter); 238 sysfs_printk_last_file(); 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)); 253 254 /* Show PC value again for GDB source code trace dump */ 255 printk("[<%08lx>] ",regs->ARM_pc); 256 print_symbol("(PC is at %s)\n", instruction_pointer(regs)); 257 258 dump_backtrace(regs, tsk); 259 dump_instr(KERN_EMERG, regs); 260 } 261 262 return ret; 263} 264 265DEFINE_SPINLOCK(die_lock); 266 267/* 268 * This function is protected against re-entrancy. 269 */ 270void die(const char *str, struct pt_regs *regs, int err) 271{ 272 struct thread_info *thread = current_thread_info(); 273 int ret; 274 275 oops_enter(); 276 277 spin_lock_irq(&die_lock); 278 console_verbose(); 279 bust_spinlocks(1); 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 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 298void 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 311static LIST_HEAD(undef_hook); 312static DEFINE_SPINLOCK(undef_lock); 313 314void register_undef_hook(struct undef_hook *hook) 315{ 316 unsigned long flags; 317 318 spin_lock_irqsave(&undef_lock, flags); 319 list_add(&hook->node, &undef_hook); 320 spin_unlock_irqrestore(&undef_lock, flags); 321} 322 323void unregister_undef_hook(struct undef_hook *hook) 324{ 325 unsigned long flags; 326 327 spin_lock_irqsave(&undef_lock, flags); 328 list_del(&hook->node); 329 spin_unlock_irqrestore(&undef_lock, flags); 330} 331 332static int call_undef_hook(struct pt_regs *regs, unsigned int instr) 333{ 334 struct undef_hook *hook; 335 unsigned long flags; 336 int (*fn)(struct pt_regs *regs, unsigned int instr) = NULL; 337 338 spin_lock_irqsave(&undef_lock, flags); 339 list_for_each_entry(hook, &undef_hook, node) 340 if ((instr & hook->instr_mask) == hook->instr_val && 341 (regs->ARM_cpsr & hook->cpsr_mask) == hook->cpsr_val) 342 fn = hook->fn; 343 spin_unlock_irqrestore(&undef_lock, flags); 344 345 return fn ? fn(regs, instr) : 1; 346} 347 348asmlinkage void __exception do_undefinstr(struct pt_regs *regs) 349{ 350 unsigned int correction = thumb_mode(regs) ? 2 : 4; 351 unsigned int instr; 352 siginfo_t info; 353 void __user *pc; 354 355 /* 356 * According to the ARM ARM, PC is 2 or 4 bytes ahead, 357 * depending whether we're in Thumb mode or not. 358 * Correct this offset. 359 */ 360 regs->ARM_pc -= correction; 361 362 pc = (void __user *)instruction_pointer(regs); 363 364 if (processor_mode(regs) == SVC_MODE) { 365 instr = *(u32 *) pc; 366 } else if (thumb_mode(regs)) { 367 get_user(instr, (u16 __user *)pc); 368 } else { 369 get_user(instr, (u32 __user *)pc); 370 } 371 372 if (call_undef_hook(regs, instr) == 0) 373 return; 374 375#ifdef CONFIG_DEBUG_USER 376 if (user_debug & UDBG_UNDEFINED) { 377 printk(KERN_INFO "%s (%d): undefined instruction: pc=%p\n", 378 current->comm, task_pid_nr(current), pc); 379 dump_instr(KERN_INFO, regs); 380 } 381#endif 382 383 info.si_signo = SIGILL; 384 info.si_errno = 0; 385 info.si_code = ILL_ILLOPC; 386 info.si_addr = pc; 387 388 arm_notify_die("Oops - undefined instruction", regs, &info, 0, 6); 389} 390 391asmlinkage void do_unexp_fiq (struct pt_regs *regs) 392{ 393 printk("Hmm. Unexpected FIQ received, but trying to continue\n"); 394 printk("You may have a hardware problem...\n"); 395} 396 397/* 398 * bad_mode handles the impossible case in the vectors. If you see one of 399 * these, then it's extremely serious, and could mean you have buggy hardware. 400 * It never returns, and never tries to sync. We hope that we can at least 401 * dump out some state information... 402 */ 403asmlinkage void bad_mode(struct pt_regs *regs, int reason) 404{ 405 console_verbose(); 406 407 printk(KERN_CRIT "Bad mode in %s handler detected\n", handler[reason]); 408 409 die("Oops - bad mode", regs, 0); 410 local_irq_disable(); 411 panic("bad mode"); 412} 413 414static int bad_syscall(int n, struct pt_regs *regs) 415{ 416 struct thread_info *thread = current_thread_info(); 417 siginfo_t info; 418 419 if (current->personality != PER_LINUX && 420 current->personality != PER_LINUX_32BIT && 421 thread->exec_domain->handler) { 422 thread->exec_domain->handler(n, regs); 423 return regs->ARM_r0; 424 } 425 426#ifdef CONFIG_DEBUG_USER 427 if (user_debug & UDBG_SYSCALL) { 428 printk(KERN_ERR "[%d] %s: obsolete system call %08x.\n", 429 task_pid_nr(current), current->comm, n); 430 dump_instr(KERN_ERR, regs); 431 } 432#endif 433 434 info.si_signo = SIGILL; 435 info.si_errno = 0; 436 info.si_code = ILL_ILLTRP; 437 info.si_addr = (void __user *)instruction_pointer(regs) - 438 (thumb_mode(regs) ? 2 : 4); 439 440 arm_notify_die("Oops - bad syscall", regs, &info, n, 0); 441 442 return regs->ARM_r0; 443} 444 445static inline void 446do_cache_op(unsigned long start, unsigned long end, int flags) 447{ 448 struct mm_struct *mm = current->active_mm; 449 struct vm_area_struct *vma; 450 451 if (end < start || flags) 452 return; 453 454 down_read(&mm->mmap_sem); 455 vma = find_vma(mm, start); 456 if (vma && vma->vm_start < end) { 457 if (start < vma->vm_start) 458 start = vma->vm_start; 459 if (end > vma->vm_end) 460 end = vma->vm_end; 461 462 flush_cache_user_range(vma, start, end); 463 } 464 up_read(&mm->mmap_sem); 465} 466 467/* 468 * Handle all unrecognised system calls. 469 * 0x9f0000 - 0x9fffff are some more esoteric system calls 470 */ 471#define NR(x) ((__ARM_NR_##x) - __ARM_NR_BASE) 472asmlinkage int arm_syscall(int no, struct pt_regs *regs) 473{ 474 struct thread_info *thread = current_thread_info(); 475 siginfo_t info; 476 477 if ((no >> 16) != (__ARM_NR_BASE>> 16)) 478 return bad_syscall(no, regs); 479 480 switch (no & 0xffff) { 481 case 0: /* branch through 0 */ 482 info.si_signo = SIGSEGV; 483 info.si_errno = 0; 484 info.si_code = SEGV_MAPERR; 485 info.si_addr = NULL; 486 487 arm_notify_die("branch through zero", regs, &info, 0, 0); 488 return 0; 489 490 case NR(breakpoint): /* SWI BREAK_POINT */ 491 regs->ARM_pc -= thumb_mode(regs) ? 2 : 4; 492 ptrace_break(current, regs); 493 return regs->ARM_r0; 494 495 /* 496 * Flush a region from virtual address 'r0' to virtual address 'r1' 497 * _exclusive_. There is no alignment requirement on either address; 498 * user space does not need to know the hardware cache layout. 499 * 500 * r2 contains flags. It should ALWAYS be passed as ZERO until it 501 * is defined to be something else. For now we ignore it, but may 502 * the fires of hell burn in your belly if you break this rule. ;) 503 * 504 * (at a later date, we may want to allow this call to not flush 505 * various aspects of the cache. Passing '0' will guarantee that 506 * everything necessary gets flushed to maintain consistency in 507 * the specified region). 508 */ 509 case NR(cacheflush): 510 do_cache_op(regs->ARM_r0, regs->ARM_r1, regs->ARM_r2); 511 return 0; 512 513 case NR(usr26): 514 if (!(elf_hwcap & HWCAP_26BIT)) 515 break; 516 regs->ARM_cpsr &= ~MODE32_BIT; 517 return regs->ARM_r0; 518 519 case NR(usr32): 520 if (!(elf_hwcap & HWCAP_26BIT)) 521 break; 522 regs->ARM_cpsr |= MODE32_BIT; 523 return regs->ARM_r0; 524 525 case NR(set_tls): 526 thread->tp_value = regs->ARM_r0; 527 if (tls_emu) 528 return 0; 529 if (has_tls_reg) { 530 asm ("mcr p15, 0, %0, c13, c0, 3" 531 : : "r" (regs->ARM_r0)); 532 } else { 533 /* 534 * User space must never try to access this directly. 535 * Expect your app to break eventually if you do so. 536 * The user helper at 0xffff0fe0 must be used instead. 537 * (see entry-armv.S for details) 538 */ 539 *((unsigned int *)0xffff0ff0) = regs->ARM_r0; 540 } 541 return 0; 542 543#ifdef CONFIG_NEEDS_SYSCALL_FOR_CMPXCHG 544 /* 545 * Atomically store r1 in *r2 if *r2 is equal to r0 for user space. 546 * Return zero in r0 if *MEM was changed or non-zero if no exchange 547 * happened. Also set the user C flag accordingly. 548 * If access permissions have to be fixed up then non-zero is 549 * returned and the operation has to be re-attempted. 550 * 551 * *NOTE*: This is a ghost syscall private to the kernel. Only the 552 * __kuser_cmpxchg code in entry-armv.S should be aware of its 553 * existence. Don't ever use this from user code. 554 */ 555 case NR(cmpxchg): 556 for (;;) { 557 extern void do_DataAbort(unsigned long addr, unsigned int fsr, 558 struct pt_regs *regs); 559 unsigned long val; 560 unsigned long addr = regs->ARM_r2; 561 struct mm_struct *mm = current->mm; 562 pgd_t *pgd; pmd_t *pmd; pte_t *pte; 563 spinlock_t *ptl; 564 565 regs->ARM_cpsr &= ~PSR_C_BIT; 566 down_read(&mm->mmap_sem); 567 pgd = pgd_offset(mm, addr); 568 if (!pgd_present(*pgd)) 569 goto bad_access; 570 pmd = pmd_offset(pgd, addr); 571 if (!pmd_present(*pmd)) 572 goto bad_access; 573 pte = pte_offset_map_lock(mm, pmd, addr, &ptl); 574 if (!pte_present(*pte) || !pte_dirty(*pte)) { 575 pte_unmap_unlock(pte, ptl); 576 goto bad_access; 577 } 578 val = *(unsigned long *)addr; 579 val -= regs->ARM_r0; 580 if (val == 0) { 581 *(unsigned long *)addr = regs->ARM_r1; 582 regs->ARM_cpsr |= PSR_C_BIT; 583 } 584 pte_unmap_unlock(pte, ptl); 585 up_read(&mm->mmap_sem); 586 return val; 587 588 bad_access: 589 up_read(&mm->mmap_sem); 590 /* simulate a write access fault */ 591 do_DataAbort(addr, 15 + (1 << 11), regs); 592 } 593#endif 594 595 default: 596 /* Calls 9f00xx..9f07ff are defined to return -ENOSYS 597 if not implemented, rather than raising SIGILL. This 598 way the calling program can gracefully determine whether 599 a feature is supported. */ 600 if ((no & 0xffff) <= 0x7ff) 601 return -ENOSYS; 602 break; 603 } 604#ifdef CONFIG_DEBUG_USER 605 /* 606 * experience shows that these seem to indicate that 607 * something catastrophic has happened 608 */ 609 if (user_debug & UDBG_SYSCALL) { 610 printk("[%d] %s: arm syscall %d\n", 611 task_pid_nr(current), current->comm, no); 612 dump_instr("", regs); 613 if (user_mode(regs)) { 614 __show_regs(regs); 615 c_backtrace(regs->ARM_fp, processor_mode(regs)); 616 } 617 } 618#endif 619 info.si_signo = SIGILL; 620 info.si_errno = 0; 621 info.si_code = ILL_ILLTRP; 622 info.si_addr = (void __user *)instruction_pointer(regs) - 623 (thumb_mode(regs) ? 2 : 4); 624 625 arm_notify_die("Oops - bad syscall(2)", regs, &info, no, 0); 626 return 0; 627} 628 629#ifdef CONFIG_TLS_REG_EMUL 630 631/* 632 * We might be running on an ARMv6+ processor which should have the TLS 633 * register but for some reason we can't use it, or maybe an SMP system 634 * using a pre-ARMv6 processor (there are apparently a few prototypes like 635 * that in existence) and therefore access to that register must be 636 * emulated. 637 */ 638 639static int get_tp_trap(struct pt_regs *regs, unsigned int instr) 640{ 641 int reg = (instr >> 12) & 15; 642 if (reg == 15) 643 return 1; 644 regs->uregs[reg] = current_thread_info()->tp_value; 645 regs->ARM_pc += 4; 646 return 0; 647} 648 649static struct undef_hook arm_mrc_hook = { 650 .instr_mask = 0x0fff0fff, 651 .instr_val = 0x0e1d0f70, 652 .cpsr_mask = PSR_T_BIT, 653 .cpsr_val = 0, 654 .fn = get_tp_trap, 655}; 656 657static int __init arm_mrc_hook_init(void) 658{ 659 register_undef_hook(&arm_mrc_hook); 660 return 0; 661} 662 663late_initcall(arm_mrc_hook_init); 664 665#endif 666 667void __bad_xchg(volatile void *ptr, int size) 668{ 669 printk("xchg: bad data size: pc 0x%p, ptr 0x%p, size %d\n", 670 __builtin_return_address(0), ptr, size); 671 BUG(); 672} 673EXPORT_SYMBOL(__bad_xchg); 674 675/* 676 * A data abort trap was taken, but we did not handle the instruction. 677 * Try to abort the user program, or panic if it was the kernel. 678 */ 679asmlinkage void 680baddataabort(int code, unsigned long instr, struct pt_regs *regs) 681{ 682 unsigned long addr = instruction_pointer(regs); 683 siginfo_t info; 684 685#ifdef CONFIG_DEBUG_USER 686 if (user_debug & UDBG_BADABORT) { 687 printk(KERN_ERR "[%d] %s: bad data abort: code %d instr 0x%08lx\n", 688 task_pid_nr(current), current->comm, code, instr); 689 dump_instr(KERN_ERR, regs); 690 show_pte(current->mm, addr); 691 } 692#endif 693 694 info.si_signo = SIGILL; 695 info.si_errno = 0; 696 info.si_code = ILL_ILLOPC; 697 info.si_addr = (void __user *)addr; 698 699 arm_notify_die("unknown data abort code", regs, &info, instr, 0); 700} 701 702void __attribute__((noreturn)) __bug(const char *file, int line) 703{ 704 printk(KERN_CRIT"kernel BUG at %s:%d!\n", file, line); 705 *(int *)0 = 0; 706 707 /* Avoid "noreturn function does return" */ 708 for (;;); 709} 710EXPORT_SYMBOL(__bug); 711 712void __readwrite_bug(const char *fn) 713{ 714 printk("%s called, but not implemented\n", fn); 715 BUG(); 716} 717EXPORT_SYMBOL(__readwrite_bug); 718 719void __pte_error(const char *file, int line, unsigned long val) 720{ 721 printk("%s:%d: bad pte %08lx.\n", file, line, val); 722} 723 724void __pmd_error(const char *file, int line, unsigned long val) 725{ 726 printk("%s:%d: bad pmd %08lx.\n", file, line, val); 727} 728 729void __pgd_error(const char *file, int line, unsigned long val) 730{ 731 printk("%s:%d: bad pgd %08lx.\n", file, line, val); 732} 733 734asmlinkage void __div0(void) 735{ 736 printk("Division by zero in kernel.\n"); 737 dump_stack(); 738} 739EXPORT_SYMBOL(__div0); 740 741void abort(void) 742{ 743 BUG(); 744 745 /* if that doesn't kill us, halt */ 746 panic("Oops failed to kill thread"); 747} 748EXPORT_SYMBOL(abort); 749 750void __init trap_init(void) 751{ 752 return; 753} 754 755static void __init kuser_get_tls_init(unsigned long vectors) 756{ 757 /* 758 * vectors + 0xfe0 = __kuser_get_tls 759 * vectors + 0xfe8 = hardware TLS instruction at 0xffff0fe8 760 */ 761 if (tls_emu || has_tls_reg) 762 memcpy((void *)vectors + 0xfe0, (void *)vectors + 0xfe8, 4); 763} 764 765void __init early_trap_init(void) 766{ 767 unsigned long vectors = CONFIG_VECTORS_BASE; 768 extern char __stubs_start[], __stubs_end[]; 769 extern char __vectors_start[], __vectors_end[]; 770 extern char __kuser_helper_start[], __kuser_helper_end[]; 771 int kuser_sz = __kuser_helper_end - __kuser_helper_start; 772 773 /* 774 * Copy the vectors, stubs and kuser helpers (in entry-armv.S) 775 * into the vector page, mapped at 0xffff0000, and ensure these 776 * are visible to the instruction stream. 777 */ 778 memcpy((void *)vectors, __vectors_start, __vectors_end - __vectors_start); 779 memcpy((void *)vectors + 0x200, __stubs_start, __stubs_end - __stubs_start); 780 memcpy((void *)vectors + 0x1000 - kuser_sz, __kuser_helper_start, kuser_sz); 781 782 /* 783 * Do processor specific fixups for the kuser helpers 784 */ 785 kuser_get_tls_init(vectors); 786 787 /* 788 * Copy signal return handlers into the vector page, and 789 * set sigreturn to be a pointer to these. 790 */ 791 memcpy((void *)KERN_SIGRETURN_CODE, sigreturn_codes, 792 sizeof(sigreturn_codes)); 793 memcpy((void *)KERN_RESTART_CODE, syscall_restart_code, 794 sizeof(syscall_restart_code)); 795 796 flush_icache_range(vectors, vectors + PAGE_SIZE); 797 modify_domain(DOMAIN_USER, DOMAIN_CLIENT); 798} 799