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/unistd.h> 33 #include <asm/traps.h> 34 #include <asm/unwind.h> 35 #include <asm/tls.h> 36 #include <asm/system_misc.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 #ifdef CONFIG_THUMB2_KERNEL 231 #define S_ISA " THUMB2" 232 #else 233 #define S_ISA " ARM" 234 #endif 235 236 static int __die(const char *str, int err, struct pt_regs *regs) 237 { 238 struct task_struct *tsk = current; 239 static int die_counter; 240 int ret; 241 242 printk(KERN_EMERG "Internal error: %s: %x [#%d]" S_PREEMPT S_SMP 243 S_ISA "\n", str, err, ++die_counter); 244 245 /* trap and error numbers are mostly meaningless on ARM */ 246 ret = notify_die(DIE_OOPS, str, regs, err, tsk->thread.trap_no, SIGSEGV); 247 if (ret == NOTIFY_STOP) 248 return 1; 249 250 print_modules(); 251 __show_regs(regs); 252 printk(KERN_EMERG "Process %.*s (pid: %d, stack limit = 0x%p)\n", 253 TASK_COMM_LEN, tsk->comm, task_pid_nr(tsk), end_of_stack(tsk)); 254 255 if (!user_mode(regs) || in_interrupt()) { 256 dump_mem(KERN_EMERG, "Stack: ", regs->ARM_sp, 257 THREAD_SIZE + (unsigned long)task_stack_page(tsk)); 258 dump_backtrace(regs, tsk); 259 dump_instr(KERN_EMERG, regs); 260 } 261 262 return 0; 263 } 264 265 static arch_spinlock_t die_lock = __ARCH_SPIN_LOCK_UNLOCKED; 266 static int die_owner = -1; 267 static unsigned int die_nest_count; 268 269 static unsigned long oops_begin(void) 270 { 271 int cpu; 272 unsigned long flags; 273 274 oops_enter(); 275 276 /* racy, but better than risking deadlock. */ 277 raw_local_irq_save(flags); 278 cpu = smp_processor_id(); 279 if (!arch_spin_trylock(&die_lock)) { 280 if (cpu == die_owner) 281 /* nested oops. should stop eventually */; 282 else 283 arch_spin_lock(&die_lock); 284 } 285 die_nest_count++; 286 die_owner = cpu; 287 console_verbose(); 288 bust_spinlocks(1); 289 return flags; 290 } 291 292 static void oops_end(unsigned long flags, struct pt_regs *regs, int signr) 293 { 294 if (regs && kexec_should_crash(current)) 295 crash_kexec(regs); 296 297 bust_spinlocks(0); 298 die_owner = -1; 299 add_taint(TAINT_DIE); 300 die_nest_count--; 301 if (!die_nest_count) 302 /* Nest count reaches zero, release the lock. */ 303 arch_spin_unlock(&die_lock); 304 raw_local_irq_restore(flags); 305 oops_exit(); 306 307 if (in_interrupt()) 308 panic("Fatal exception in interrupt"); 309 if (panic_on_oops) 310 panic("Fatal exception"); 311 if (signr) 312 do_exit(signr); 313 } 314 315 /* 316 * This function is protected against re-entrancy. 317 */ 318 void die(const char *str, struct pt_regs *regs, int err) 319 { 320 enum bug_trap_type bug_type = BUG_TRAP_TYPE_NONE; 321 unsigned long flags = oops_begin(); 322 int sig = SIGSEGV; 323 324 if (!user_mode(regs)) 325 bug_type = report_bug(regs->ARM_pc, regs); 326 if (bug_type != BUG_TRAP_TYPE_NONE) 327 str = "Oops - BUG"; 328 329 if (__die(str, err, regs)) 330 sig = 0; 331 332 oops_end(flags, regs, sig); 333 } 334 335 void arm_notify_die(const char *str, struct pt_regs *regs, 336 struct siginfo *info, unsigned long err, unsigned long trap) 337 { 338 if (user_mode(regs)) { 339 current->thread.error_code = err; 340 current->thread.trap_no = trap; 341 342 force_sig_info(info->si_signo, info, current); 343 } else { 344 die(str, regs, err); 345 } 346 } 347 348 #ifdef CONFIG_GENERIC_BUG 349 350 int is_valid_bugaddr(unsigned long pc) 351 { 352 #ifdef CONFIG_THUMB2_KERNEL 353 unsigned short bkpt; 354 #else 355 unsigned long bkpt; 356 #endif 357 358 if (probe_kernel_address((unsigned *)pc, bkpt)) 359 return 0; 360 361 return bkpt == BUG_INSTR_VALUE; 362 } 363 364 #endif 365 366 static LIST_HEAD(undef_hook); 367 static DEFINE_RAW_SPINLOCK(undef_lock); 368 369 void register_undef_hook(struct undef_hook *hook) 370 { 371 unsigned long flags; 372 373 raw_spin_lock_irqsave(&undef_lock, flags); 374 list_add(&hook->node, &undef_hook); 375 raw_spin_unlock_irqrestore(&undef_lock, flags); 376 } 377 378 void unregister_undef_hook(struct undef_hook *hook) 379 { 380 unsigned long flags; 381 382 raw_spin_lock_irqsave(&undef_lock, flags); 383 list_del(&hook->node); 384 raw_spin_unlock_irqrestore(&undef_lock, flags); 385 } 386 387 static int call_undef_hook(struct pt_regs *regs, unsigned int instr) 388 { 389 struct undef_hook *hook; 390 unsigned long flags; 391 int (*fn)(struct pt_regs *regs, unsigned int instr) = NULL; 392 393 raw_spin_lock_irqsave(&undef_lock, flags); 394 list_for_each_entry(hook, &undef_hook, node) 395 if ((instr & hook->instr_mask) == hook->instr_val && 396 (regs->ARM_cpsr & hook->cpsr_mask) == hook->cpsr_val) 397 fn = hook->fn; 398 raw_spin_unlock_irqrestore(&undef_lock, flags); 399 400 return fn ? fn(regs, instr) : 1; 401 } 402 403 asmlinkage void __exception do_undefinstr(struct pt_regs *regs) 404 { 405 unsigned int instr; 406 siginfo_t info; 407 void __user *pc; 408 409 pc = (void __user *)instruction_pointer(regs); 410 411 if (processor_mode(regs) == SVC_MODE) { 412 #ifdef CONFIG_THUMB2_KERNEL 413 if (thumb_mode(regs)) { 414 instr = ((u16 *)pc)[0]; 415 if (is_wide_instruction(instr)) { 416 instr <<= 16; 417 instr |= ((u16 *)pc)[1]; 418 } 419 } else 420 #endif 421 instr = *(u32 *) pc; 422 } else if (thumb_mode(regs)) { 423 get_user(instr, (u16 __user *)pc); 424 if (is_wide_instruction(instr)) { 425 unsigned int instr2; 426 get_user(instr2, (u16 __user *)pc+1); 427 instr <<= 16; 428 instr |= instr2; 429 } 430 } else { 431 get_user(instr, (u32 __user *)pc); 432 } 433 434 if (call_undef_hook(regs, instr) == 0) 435 return; 436 437 #ifdef CONFIG_DEBUG_USER 438 if (user_debug & UDBG_UNDEFINED) { 439 printk(KERN_INFO "%s (%d): undefined instruction: pc=%p\n", 440 current->comm, task_pid_nr(current), pc); 441 dump_instr(KERN_INFO, regs); 442 } 443 #endif 444 445 info.si_signo = SIGILL; 446 info.si_errno = 0; 447 info.si_code = ILL_ILLOPC; 448 info.si_addr = pc; 449 450 arm_notify_die("Oops - undefined instruction", regs, &info, 0, 6); 451 } 452 453 asmlinkage void do_unexp_fiq (struct pt_regs *regs) 454 { 455 printk("Hmm. Unexpected FIQ received, but trying to continue\n"); 456 printk("You may have a hardware problem...\n"); 457 } 458 459 /* 460 * bad_mode handles the impossible case in the vectors. If you see one of 461 * these, then it's extremely serious, and could mean you have buggy hardware. 462 * It never returns, and never tries to sync. We hope that we can at least 463 * dump out some state information... 464 */ 465 asmlinkage void bad_mode(struct pt_regs *regs, int reason) 466 { 467 console_verbose(); 468 469 printk(KERN_CRIT "Bad mode in %s handler detected\n", handler[reason]); 470 471 die("Oops - bad mode", regs, 0); 472 local_irq_disable(); 473 panic("bad mode"); 474 } 475 476 static int bad_syscall(int n, struct pt_regs *regs) 477 { 478 struct thread_info *thread = current_thread_info(); 479 siginfo_t info; 480 481 if ((current->personality & PER_MASK) != PER_LINUX && 482 thread->exec_domain->handler) { 483 thread->exec_domain->handler(n, regs); 484 return regs->ARM_r0; 485 } 486 487 #ifdef CONFIG_DEBUG_USER 488 if (user_debug & UDBG_SYSCALL) { 489 printk(KERN_ERR "[%d] %s: obsolete system call %08x.\n", 490 task_pid_nr(current), current->comm, n); 491 dump_instr(KERN_ERR, regs); 492 } 493 #endif 494 495 info.si_signo = SIGILL; 496 info.si_errno = 0; 497 info.si_code = ILL_ILLTRP; 498 info.si_addr = (void __user *)instruction_pointer(regs) - 499 (thumb_mode(regs) ? 2 : 4); 500 501 arm_notify_die("Oops - bad syscall", regs, &info, n, 0); 502 503 return regs->ARM_r0; 504 } 505 506 static inline int 507 do_cache_op(unsigned long start, unsigned long end, int flags) 508 { 509 struct mm_struct *mm = current->active_mm; 510 struct vm_area_struct *vma; 511 512 if (end < start || flags) 513 return -EINVAL; 514 515 down_read(&mm->mmap_sem); 516 vma = find_vma(mm, start); 517 if (vma && vma->vm_start < end) { 518 if (start < vma->vm_start) 519 start = vma->vm_start; 520 if (end > vma->vm_end) 521 end = vma->vm_end; 522 523 up_read(&mm->mmap_sem); 524 return flush_cache_user_range(start, end); 525 } 526 up_read(&mm->mmap_sem); 527 return -EINVAL; 528 } 529 530 /* 531 * Handle all unrecognised system calls. 532 * 0x9f0000 - 0x9fffff are some more esoteric system calls 533 */ 534 #define NR(x) ((__ARM_NR_##x) - __ARM_NR_BASE) 535 asmlinkage int arm_syscall(int no, struct pt_regs *regs) 536 { 537 struct thread_info *thread = current_thread_info(); 538 siginfo_t info; 539 540 if ((no >> 16) != (__ARM_NR_BASE>> 16)) 541 return bad_syscall(no, regs); 542 543 switch (no & 0xffff) { 544 case 0: /* branch through 0 */ 545 info.si_signo = SIGSEGV; 546 info.si_errno = 0; 547 info.si_code = SEGV_MAPERR; 548 info.si_addr = NULL; 549 550 arm_notify_die("branch through zero", regs, &info, 0, 0); 551 return 0; 552 553 case NR(breakpoint): /* SWI BREAK_POINT */ 554 regs->ARM_pc -= thumb_mode(regs) ? 2 : 4; 555 ptrace_break(current, regs); 556 return regs->ARM_r0; 557 558 /* 559 * Flush a region from virtual address 'r0' to virtual address 'r1' 560 * _exclusive_. There is no alignment requirement on either address; 561 * user space does not need to know the hardware cache layout. 562 * 563 * r2 contains flags. It should ALWAYS be passed as ZERO until it 564 * is defined to be something else. For now we ignore it, but may 565 * the fires of hell burn in your belly if you break this rule. ;) 566 * 567 * (at a later date, we may want to allow this call to not flush 568 * various aspects of the cache. Passing '0' will guarantee that 569 * everything necessary gets flushed to maintain consistency in 570 * the specified region). 571 */ 572 case NR(cacheflush): 573 return do_cache_op(regs->ARM_r0, regs->ARM_r1, regs->ARM_r2); 574 575 case NR(usr26): 576 if (!(elf_hwcap & HWCAP_26BIT)) 577 break; 578 regs->ARM_cpsr &= ~MODE32_BIT; 579 return regs->ARM_r0; 580 581 case NR(usr32): 582 if (!(elf_hwcap & HWCAP_26BIT)) 583 break; 584 regs->ARM_cpsr |= MODE32_BIT; 585 return regs->ARM_r0; 586 587 case NR(set_tls): 588 thread->tp_value = regs->ARM_r0; 589 if (tls_emu) 590 return 0; 591 if (has_tls_reg) { 592 asm ("mcr p15, 0, %0, c13, c0, 3" 593 : : "r" (regs->ARM_r0)); 594 } else { 595 /* 596 * User space must never try to access this directly. 597 * Expect your app to break eventually if you do so. 598 * The user helper at 0xffff0fe0 must be used instead. 599 * (see entry-armv.S for details) 600 */ 601 *((unsigned int *)0xffff0ff0) = regs->ARM_r0; 602 } 603 return 0; 604 605 #ifdef CONFIG_NEEDS_SYSCALL_FOR_CMPXCHG 606 /* 607 * Atomically store r1 in *r2 if *r2 is equal to r0 for user space. 608 * Return zero in r0 if *MEM was changed or non-zero if no exchange 609 * happened. Also set the user C flag accordingly. 610 * If access permissions have to be fixed up then non-zero is 611 * returned and the operation has to be re-attempted. 612 * 613 * *NOTE*: This is a ghost syscall private to the kernel. Only the 614 * __kuser_cmpxchg code in entry-armv.S should be aware of its 615 * existence. Don't ever use this from user code. 616 */ 617 case NR(cmpxchg): 618 for (;;) { 619 extern void do_DataAbort(unsigned long addr, unsigned int fsr, 620 struct pt_regs *regs); 621 unsigned long val; 622 unsigned long addr = regs->ARM_r2; 623 struct mm_struct *mm = current->mm; 624 pgd_t *pgd; pmd_t *pmd; pte_t *pte; 625 spinlock_t *ptl; 626 627 regs->ARM_cpsr &= ~PSR_C_BIT; 628 down_read(&mm->mmap_sem); 629 pgd = pgd_offset(mm, addr); 630 if (!pgd_present(*pgd)) 631 goto bad_access; 632 pmd = pmd_offset(pgd, addr); 633 if (!pmd_present(*pmd)) 634 goto bad_access; 635 pte = pte_offset_map_lock(mm, pmd, addr, &ptl); 636 if (!pte_present(*pte) || !pte_write(*pte) || !pte_dirty(*pte)) { 637 pte_unmap_unlock(pte, ptl); 638 goto bad_access; 639 } 640 val = *(unsigned long *)addr; 641 val -= regs->ARM_r0; 642 if (val == 0) { 643 *(unsigned long *)addr = regs->ARM_r1; 644 regs->ARM_cpsr |= PSR_C_BIT; 645 } 646 pte_unmap_unlock(pte, ptl); 647 up_read(&mm->mmap_sem); 648 return val; 649 650 bad_access: 651 up_read(&mm->mmap_sem); 652 /* simulate a write access fault */ 653 do_DataAbort(addr, 15 + (1 << 11), regs); 654 } 655 #endif 656 657 default: 658 /* Calls 9f00xx..9f07ff are defined to return -ENOSYS 659 if not implemented, rather than raising SIGILL. This 660 way the calling program can gracefully determine whether 661 a feature is supported. */ 662 if ((no & 0xffff) <= 0x7ff) 663 return -ENOSYS; 664 break; 665 } 666 #ifdef CONFIG_DEBUG_USER 667 /* 668 * experience shows that these seem to indicate that 669 * something catastrophic has happened 670 */ 671 if (user_debug & UDBG_SYSCALL) { 672 printk("[%d] %s: arm syscall %d\n", 673 task_pid_nr(current), current->comm, no); 674 dump_instr("", regs); 675 if (user_mode(regs)) { 676 __show_regs(regs); 677 c_backtrace(regs->ARM_fp, processor_mode(regs)); 678 } 679 } 680 #endif 681 info.si_signo = SIGILL; 682 info.si_errno = 0; 683 info.si_code = ILL_ILLTRP; 684 info.si_addr = (void __user *)instruction_pointer(regs) - 685 (thumb_mode(regs) ? 2 : 4); 686 687 arm_notify_die("Oops - bad syscall(2)", regs, &info, no, 0); 688 return 0; 689 } 690 691 #ifdef CONFIG_TLS_REG_EMUL 692 693 /* 694 * We might be running on an ARMv6+ processor which should have the TLS 695 * register but for some reason we can't use it, or maybe an SMP system 696 * using a pre-ARMv6 processor (there are apparently a few prototypes like 697 * that in existence) and therefore access to that register must be 698 * emulated. 699 */ 700 701 static int get_tp_trap(struct pt_regs *regs, unsigned int instr) 702 { 703 int reg = (instr >> 12) & 15; 704 if (reg == 15) 705 return 1; 706 regs->uregs[reg] = current_thread_info()->tp_value; 707 regs->ARM_pc += 4; 708 return 0; 709 } 710 711 static struct undef_hook arm_mrc_hook = { 712 .instr_mask = 0x0fff0fff, 713 .instr_val = 0x0e1d0f70, 714 .cpsr_mask = PSR_T_BIT, 715 .cpsr_val = 0, 716 .fn = get_tp_trap, 717 }; 718 719 static int __init arm_mrc_hook_init(void) 720 { 721 register_undef_hook(&arm_mrc_hook); 722 return 0; 723 } 724 725 late_initcall(arm_mrc_hook_init); 726 727 #endif 728 729 void __bad_xchg(volatile void *ptr, int size) 730 { 731 printk("xchg: bad data size: pc 0x%p, ptr 0x%p, size %d\n", 732 __builtin_return_address(0), ptr, size); 733 BUG(); 734 } 735 EXPORT_SYMBOL(__bad_xchg); 736 737 /* 738 * A data abort trap was taken, but we did not handle the instruction. 739 * Try to abort the user program, or panic if it was the kernel. 740 */ 741 asmlinkage void 742 baddataabort(int code, unsigned long instr, struct pt_regs *regs) 743 { 744 unsigned long addr = instruction_pointer(regs); 745 siginfo_t info; 746 747 #ifdef CONFIG_DEBUG_USER 748 if (user_debug & UDBG_BADABORT) { 749 printk(KERN_ERR "[%d] %s: bad data abort: code %d instr 0x%08lx\n", 750 task_pid_nr(current), current->comm, code, instr); 751 dump_instr(KERN_ERR, regs); 752 show_pte(current->mm, addr); 753 } 754 #endif 755 756 info.si_signo = SIGILL; 757 info.si_errno = 0; 758 info.si_code = ILL_ILLOPC; 759 info.si_addr = (void __user *)addr; 760 761 arm_notify_die("unknown data abort code", regs, &info, instr, 0); 762 } 763 764 void __readwrite_bug(const char *fn) 765 { 766 printk("%s called, but not implemented\n", fn); 767 BUG(); 768 } 769 EXPORT_SYMBOL(__readwrite_bug); 770 771 void __pte_error(const char *file, int line, pte_t pte) 772 { 773 printk("%s:%d: bad pte %08llx.\n", file, line, (long long)pte_val(pte)); 774 } 775 776 void __pmd_error(const char *file, int line, pmd_t pmd) 777 { 778 printk("%s:%d: bad pmd %08llx.\n", file, line, (long long)pmd_val(pmd)); 779 } 780 781 void __pgd_error(const char *file, int line, pgd_t pgd) 782 { 783 printk("%s:%d: bad pgd %08llx.\n", file, line, (long long)pgd_val(pgd)); 784 } 785 786 asmlinkage void __div0(void) 787 { 788 printk("Division by zero in kernel.\n"); 789 dump_stack(); 790 } 791 EXPORT_SYMBOL(__div0); 792 793 void abort(void) 794 { 795 BUG(); 796 797 /* if that doesn't kill us, halt */ 798 panic("Oops failed to kill thread"); 799 } 800 EXPORT_SYMBOL(abort); 801 802 void __init trap_init(void) 803 { 804 return; 805 } 806 807 static void __init kuser_get_tls_init(unsigned long vectors) 808 { 809 /* 810 * vectors + 0xfe0 = __kuser_get_tls 811 * vectors + 0xfe8 = hardware TLS instruction at 0xffff0fe8 812 */ 813 if (tls_emu || has_tls_reg) 814 memcpy((void *)vectors + 0xfe0, (void *)vectors + 0xfe8, 4); 815 } 816 817 void __init early_trap_init(void *vectors_base) 818 { 819 unsigned long vectors = (unsigned long)vectors_base; 820 extern char __stubs_start[], __stubs_end[]; 821 extern char __vectors_start[], __vectors_end[]; 822 extern char __kuser_helper_start[], __kuser_helper_end[]; 823 int kuser_sz = __kuser_helper_end - __kuser_helper_start; 824 825 vectors_page = vectors_base; 826 827 /* 828 * Copy the vectors, stubs and kuser helpers (in entry-armv.S) 829 * into the vector page, mapped at 0xffff0000, and ensure these 830 * are visible to the instruction stream. 831 */ 832 memcpy((void *)vectors, __vectors_start, __vectors_end - __vectors_start); 833 memcpy((void *)vectors + 0x200, __stubs_start, __stubs_end - __stubs_start); 834 memcpy((void *)vectors + 0x1000 - kuser_sz, __kuser_helper_start, kuser_sz); 835 836 /* 837 * Do processor specific fixups for the kuser helpers 838 */ 839 kuser_get_tls_init(vectors); 840 841 /* 842 * Copy signal return handlers into the vector page, and 843 * set sigreturn to be a pointer to these. 844 */ 845 memcpy((void *)(vectors + KERN_SIGRETURN_CODE - CONFIG_VECTORS_BASE), 846 sigreturn_codes, sizeof(sigreturn_codes)); 847 848 flush_icache_range(vectors, vectors + PAGE_SIZE); 849 modify_domain(DOMAIN_USER, DOMAIN_CLIENT); 850 } 851