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 correction = thumb_mode(regs) ? 2 : 4; 406 unsigned int instr; 407 siginfo_t info; 408 void __user *pc; 409 410 /* 411 * According to the ARM ARM, PC is 2 or 4 bytes ahead, 412 * depending whether we're in Thumb mode or not. 413 * Correct this offset. 414 */ 415 regs->ARM_pc -= correction; 416 417 pc = (void __user *)instruction_pointer(regs); 418 419 if (processor_mode(regs) == SVC_MODE) { 420 #ifdef CONFIG_THUMB2_KERNEL 421 if (thumb_mode(regs)) { 422 instr = ((u16 *)pc)[0]; 423 if (is_wide_instruction(instr)) { 424 instr <<= 16; 425 instr |= ((u16 *)pc)[1]; 426 } 427 } else 428 #endif 429 instr = *(u32 *) pc; 430 } else if (thumb_mode(regs)) { 431 get_user(instr, (u16 __user *)pc); 432 if (is_wide_instruction(instr)) { 433 unsigned int instr2; 434 get_user(instr2, (u16 __user *)pc+1); 435 instr <<= 16; 436 instr |= instr2; 437 } 438 } else { 439 get_user(instr, (u32 __user *)pc); 440 } 441 442 if (call_undef_hook(regs, instr) == 0) 443 return; 444 445 #ifdef CONFIG_DEBUG_USER 446 if (user_debug & UDBG_UNDEFINED) { 447 printk(KERN_INFO "%s (%d): undefined instruction: pc=%p\n", 448 current->comm, task_pid_nr(current), pc); 449 dump_instr(KERN_INFO, regs); 450 } 451 #endif 452 453 info.si_signo = SIGILL; 454 info.si_errno = 0; 455 info.si_code = ILL_ILLOPC; 456 info.si_addr = pc; 457 458 arm_notify_die("Oops - undefined instruction", regs, &info, 0, 6); 459 } 460 461 asmlinkage void do_unexp_fiq (struct pt_regs *regs) 462 { 463 printk("Hmm. Unexpected FIQ received, but trying to continue\n"); 464 printk("You may have a hardware problem...\n"); 465 } 466 467 /* 468 * bad_mode handles the impossible case in the vectors. If you see one of 469 * these, then it's extremely serious, and could mean you have buggy hardware. 470 * It never returns, and never tries to sync. We hope that we can at least 471 * dump out some state information... 472 */ 473 asmlinkage void bad_mode(struct pt_regs *regs, int reason) 474 { 475 console_verbose(); 476 477 printk(KERN_CRIT "Bad mode in %s handler detected\n", handler[reason]); 478 479 die("Oops - bad mode", regs, 0); 480 local_irq_disable(); 481 panic("bad mode"); 482 } 483 484 static int bad_syscall(int n, struct pt_regs *regs) 485 { 486 struct thread_info *thread = current_thread_info(); 487 siginfo_t info; 488 489 if ((current->personality & PER_MASK) != PER_LINUX && 490 thread->exec_domain->handler) { 491 thread->exec_domain->handler(n, regs); 492 return regs->ARM_r0; 493 } 494 495 #ifdef CONFIG_DEBUG_USER 496 if (user_debug & UDBG_SYSCALL) { 497 printk(KERN_ERR "[%d] %s: obsolete system call %08x.\n", 498 task_pid_nr(current), current->comm, n); 499 dump_instr(KERN_ERR, regs); 500 } 501 #endif 502 503 info.si_signo = SIGILL; 504 info.si_errno = 0; 505 info.si_code = ILL_ILLTRP; 506 info.si_addr = (void __user *)instruction_pointer(regs) - 507 (thumb_mode(regs) ? 2 : 4); 508 509 arm_notify_die("Oops - bad syscall", regs, &info, n, 0); 510 511 return regs->ARM_r0; 512 } 513 514 static inline int 515 do_cache_op(unsigned long start, unsigned long end, int flags) 516 { 517 struct mm_struct *mm = current->active_mm; 518 struct vm_area_struct *vma; 519 520 if (end < start || flags) 521 return -EINVAL; 522 523 down_read(&mm->mmap_sem); 524 vma = find_vma(mm, start); 525 if (vma && vma->vm_start < end) { 526 if (start < vma->vm_start) 527 start = vma->vm_start; 528 if (end > vma->vm_end) 529 end = vma->vm_end; 530 531 up_read(&mm->mmap_sem); 532 return flush_cache_user_range(start, end); 533 } 534 up_read(&mm->mmap_sem); 535 return -EINVAL; 536 } 537 538 /* 539 * Handle all unrecognised system calls. 540 * 0x9f0000 - 0x9fffff are some more esoteric system calls 541 */ 542 #define NR(x) ((__ARM_NR_##x) - __ARM_NR_BASE) 543 asmlinkage int arm_syscall(int no, struct pt_regs *regs) 544 { 545 struct thread_info *thread = current_thread_info(); 546 siginfo_t info; 547 548 if ((no >> 16) != (__ARM_NR_BASE>> 16)) 549 return bad_syscall(no, regs); 550 551 switch (no & 0xffff) { 552 case 0: /* branch through 0 */ 553 info.si_signo = SIGSEGV; 554 info.si_errno = 0; 555 info.si_code = SEGV_MAPERR; 556 info.si_addr = NULL; 557 558 arm_notify_die("branch through zero", regs, &info, 0, 0); 559 return 0; 560 561 case NR(breakpoint): /* SWI BREAK_POINT */ 562 regs->ARM_pc -= thumb_mode(regs) ? 2 : 4; 563 ptrace_break(current, regs); 564 return regs->ARM_r0; 565 566 /* 567 * Flush a region from virtual address 'r0' to virtual address 'r1' 568 * _exclusive_. There is no alignment requirement on either address; 569 * user space does not need to know the hardware cache layout. 570 * 571 * r2 contains flags. It should ALWAYS be passed as ZERO until it 572 * is defined to be something else. For now we ignore it, but may 573 * the fires of hell burn in your belly if you break this rule. ;) 574 * 575 * (at a later date, we may want to allow this call to not flush 576 * various aspects of the cache. Passing '0' will guarantee that 577 * everything necessary gets flushed to maintain consistency in 578 * the specified region). 579 */ 580 case NR(cacheflush): 581 return do_cache_op(regs->ARM_r0, regs->ARM_r1, regs->ARM_r2); 582 583 case NR(usr26): 584 if (!(elf_hwcap & HWCAP_26BIT)) 585 break; 586 regs->ARM_cpsr &= ~MODE32_BIT; 587 return regs->ARM_r0; 588 589 case NR(usr32): 590 if (!(elf_hwcap & HWCAP_26BIT)) 591 break; 592 regs->ARM_cpsr |= MODE32_BIT; 593 return regs->ARM_r0; 594 595 case NR(set_tls): 596 thread->tp_value = regs->ARM_r0; 597 if (tls_emu) 598 return 0; 599 if (has_tls_reg) { 600 asm ("mcr p15, 0, %0, c13, c0, 3" 601 : : "r" (regs->ARM_r0)); 602 } else { 603 /* 604 * User space must never try to access this directly. 605 * Expect your app to break eventually if you do so. 606 * The user helper at 0xffff0fe0 must be used instead. 607 * (see entry-armv.S for details) 608 */ 609 *((unsigned int *)0xffff0ff0) = regs->ARM_r0; 610 } 611 return 0; 612 613 #ifdef CONFIG_NEEDS_SYSCALL_FOR_CMPXCHG 614 /* 615 * Atomically store r1 in *r2 if *r2 is equal to r0 for user space. 616 * Return zero in r0 if *MEM was changed or non-zero if no exchange 617 * happened. Also set the user C flag accordingly. 618 * If access permissions have to be fixed up then non-zero is 619 * returned and the operation has to be re-attempted. 620 * 621 * *NOTE*: This is a ghost syscall private to the kernel. Only the 622 * __kuser_cmpxchg code in entry-armv.S should be aware of its 623 * existence. Don't ever use this from user code. 624 */ 625 case NR(cmpxchg): 626 for (;;) { 627 extern void do_DataAbort(unsigned long addr, unsigned int fsr, 628 struct pt_regs *regs); 629 unsigned long val; 630 unsigned long addr = regs->ARM_r2; 631 struct mm_struct *mm = current->mm; 632 pgd_t *pgd; pmd_t *pmd; pte_t *pte; 633 spinlock_t *ptl; 634 635 regs->ARM_cpsr &= ~PSR_C_BIT; 636 down_read(&mm->mmap_sem); 637 pgd = pgd_offset(mm, addr); 638 if (!pgd_present(*pgd)) 639 goto bad_access; 640 pmd = pmd_offset(pgd, addr); 641 if (!pmd_present(*pmd)) 642 goto bad_access; 643 pte = pte_offset_map_lock(mm, pmd, addr, &ptl); 644 if (!pte_present(*pte) || !pte_write(*pte) || !pte_dirty(*pte)) { 645 pte_unmap_unlock(pte, ptl); 646 goto bad_access; 647 } 648 val = *(unsigned long *)addr; 649 val -= regs->ARM_r0; 650 if (val == 0) { 651 *(unsigned long *)addr = regs->ARM_r1; 652 regs->ARM_cpsr |= PSR_C_BIT; 653 } 654 pte_unmap_unlock(pte, ptl); 655 up_read(&mm->mmap_sem); 656 return val; 657 658 bad_access: 659 up_read(&mm->mmap_sem); 660 /* simulate a write access fault */ 661 do_DataAbort(addr, 15 + (1 << 11), regs); 662 } 663 #endif 664 665 default: 666 /* Calls 9f00xx..9f07ff are defined to return -ENOSYS 667 if not implemented, rather than raising SIGILL. This 668 way the calling program can gracefully determine whether 669 a feature is supported. */ 670 if ((no & 0xffff) <= 0x7ff) 671 return -ENOSYS; 672 break; 673 } 674 #ifdef CONFIG_DEBUG_USER 675 /* 676 * experience shows that these seem to indicate that 677 * something catastrophic has happened 678 */ 679 if (user_debug & UDBG_SYSCALL) { 680 printk("[%d] %s: arm syscall %d\n", 681 task_pid_nr(current), current->comm, no); 682 dump_instr("", regs); 683 if (user_mode(regs)) { 684 __show_regs(regs); 685 c_backtrace(regs->ARM_fp, processor_mode(regs)); 686 } 687 } 688 #endif 689 info.si_signo = SIGILL; 690 info.si_errno = 0; 691 info.si_code = ILL_ILLTRP; 692 info.si_addr = (void __user *)instruction_pointer(regs) - 693 (thumb_mode(regs) ? 2 : 4); 694 695 arm_notify_die("Oops - bad syscall(2)", regs, &info, no, 0); 696 return 0; 697 } 698 699 #ifdef CONFIG_TLS_REG_EMUL 700 701 /* 702 * We might be running on an ARMv6+ processor which should have the TLS 703 * register but for some reason we can't use it, or maybe an SMP system 704 * using a pre-ARMv6 processor (there are apparently a few prototypes like 705 * that in existence) and therefore access to that register must be 706 * emulated. 707 */ 708 709 static int get_tp_trap(struct pt_regs *regs, unsigned int instr) 710 { 711 int reg = (instr >> 12) & 15; 712 if (reg == 15) 713 return 1; 714 regs->uregs[reg] = current_thread_info()->tp_value; 715 regs->ARM_pc += 4; 716 return 0; 717 } 718 719 static struct undef_hook arm_mrc_hook = { 720 .instr_mask = 0x0fff0fff, 721 .instr_val = 0x0e1d0f70, 722 .cpsr_mask = PSR_T_BIT, 723 .cpsr_val = 0, 724 .fn = get_tp_trap, 725 }; 726 727 static int __init arm_mrc_hook_init(void) 728 { 729 register_undef_hook(&arm_mrc_hook); 730 return 0; 731 } 732 733 late_initcall(arm_mrc_hook_init); 734 735 #endif 736 737 void __bad_xchg(volatile void *ptr, int size) 738 { 739 printk("xchg: bad data size: pc 0x%p, ptr 0x%p, size %d\n", 740 __builtin_return_address(0), ptr, size); 741 BUG(); 742 } 743 EXPORT_SYMBOL(__bad_xchg); 744 745 /* 746 * A data abort trap was taken, but we did not handle the instruction. 747 * Try to abort the user program, or panic if it was the kernel. 748 */ 749 asmlinkage void 750 baddataabort(int code, unsigned long instr, struct pt_regs *regs) 751 { 752 unsigned long addr = instruction_pointer(regs); 753 siginfo_t info; 754 755 #ifdef CONFIG_DEBUG_USER 756 if (user_debug & UDBG_BADABORT) { 757 printk(KERN_ERR "[%d] %s: bad data abort: code %d instr 0x%08lx\n", 758 task_pid_nr(current), current->comm, code, instr); 759 dump_instr(KERN_ERR, regs); 760 show_pte(current->mm, addr); 761 } 762 #endif 763 764 info.si_signo = SIGILL; 765 info.si_errno = 0; 766 info.si_code = ILL_ILLOPC; 767 info.si_addr = (void __user *)addr; 768 769 arm_notify_die("unknown data abort code", regs, &info, instr, 0); 770 } 771 772 void __readwrite_bug(const char *fn) 773 { 774 printk("%s called, but not implemented\n", fn); 775 BUG(); 776 } 777 EXPORT_SYMBOL(__readwrite_bug); 778 779 void __pte_error(const char *file, int line, pte_t pte) 780 { 781 printk("%s:%d: bad pte %08llx.\n", file, line, (long long)pte_val(pte)); 782 } 783 784 void __pmd_error(const char *file, int line, pmd_t pmd) 785 { 786 printk("%s:%d: bad pmd %08llx.\n", file, line, (long long)pmd_val(pmd)); 787 } 788 789 void __pgd_error(const char *file, int line, pgd_t pgd) 790 { 791 printk("%s:%d: bad pgd %08llx.\n", file, line, (long long)pgd_val(pgd)); 792 } 793 794 asmlinkage void __div0(void) 795 { 796 printk("Division by zero in kernel.\n"); 797 dump_stack(); 798 } 799 EXPORT_SYMBOL(__div0); 800 801 void abort(void) 802 { 803 BUG(); 804 805 /* if that doesn't kill us, halt */ 806 panic("Oops failed to kill thread"); 807 } 808 EXPORT_SYMBOL(abort); 809 810 void __init trap_init(void) 811 { 812 return; 813 } 814 815 static void __init kuser_get_tls_init(unsigned long vectors) 816 { 817 /* 818 * vectors + 0xfe0 = __kuser_get_tls 819 * vectors + 0xfe8 = hardware TLS instruction at 0xffff0fe8 820 */ 821 if (tls_emu || has_tls_reg) 822 memcpy((void *)vectors + 0xfe0, (void *)vectors + 0xfe8, 4); 823 } 824 825 void __init early_trap_init(void *vectors_base) 826 { 827 unsigned long vectors = (unsigned long)vectors_base; 828 extern char __stubs_start[], __stubs_end[]; 829 extern char __vectors_start[], __vectors_end[]; 830 extern char __kuser_helper_start[], __kuser_helper_end[]; 831 int kuser_sz = __kuser_helper_end - __kuser_helper_start; 832 833 vectors_page = vectors_base; 834 835 /* 836 * Copy the vectors, stubs and kuser helpers (in entry-armv.S) 837 * into the vector page, mapped at 0xffff0000, and ensure these 838 * are visible to the instruction stream. 839 */ 840 memcpy((void *)vectors, __vectors_start, __vectors_end - __vectors_start); 841 memcpy((void *)vectors + 0x200, __stubs_start, __stubs_end - __stubs_start); 842 memcpy((void *)vectors + 0x1000 - kuser_sz, __kuser_helper_start, kuser_sz); 843 844 /* 845 * Do processor specific fixups for the kuser helpers 846 */ 847 kuser_get_tls_init(vectors); 848 849 /* 850 * Copy signal return handlers into the vector page, and 851 * set sigreturn to be a pointer to these. 852 */ 853 memcpy((void *)(vectors + KERN_SIGRETURN_CODE - CONFIG_VECTORS_BASE), 854 sigreturn_codes, sizeof(sigreturn_codes)); 855 memcpy((void *)(vectors + KERN_RESTART_CODE - CONFIG_VECTORS_BASE), 856 syscall_restart_code, sizeof(syscall_restart_code)); 857 858 flush_icache_range(vectors, vectors + PAGE_SIZE); 859 modify_domain(DOMAIN_USER, DOMAIN_CLIENT); 860 } 861