arch/s390/mm/fault.c

   1 /*
   2  *  arch/s390/mm/fault.c
   3  *
   4  *  S390 version
   5  *    Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation
   6  *    Author(s): Hartmut Penner (hp@de.ibm.com)
   7  *               Ulrich Weigand (uweigand@de.ibm.com)
   8  *
   9  *  Derived from "arch/i386/mm/fault.c"
  10  *    Copyright (C) 1995  Linus Torvalds
  11  */
  12
  13 #include <linux/kernel_stat.h>
  14 #include <linux/perf_event.h>
  15 #include <linux/signal.h>
  16 #include <linux/sched.h>
  17 #include <linux/kernel.h>
  18 #include <linux/errno.h>
  19 #include <linux/string.h>
  20 #include <linux/types.h>
  21 #include <linux/ptrace.h>
  22 #include <linux/mman.h>
  23 #include <linux/mm.h>
  24 #include <linux/compat.h>
  25 #include <linux/smp.h>
  26 #include <linux/kdebug.h>
  27 #include <linux/init.h>
  28 #include <linux/console.h>
  29 #include <linux/module.h>
  30 #include <linux/hardirq.h>
  31 #include <linux/kprobes.h>
  32 #include <linux/uaccess.h>
  33 #include <linux/hugetlb.h>
  34 #include <asm/asm-offsets.h>
  35 #include <asm/system.h>
  36 #include <asm/pgtable.h>
  37 #include <asm/irq.h>
  38 #include <asm/mmu_context.h>
  39 #include <asm/compat.h>
  40 #include "../kernel/entry.h"
  41
  42 #ifndef CONFIG_64BIT
  43 #define __FAIL_ADDR_MASK 0x7ffff000
  44 #define __SUBCODE_MASK 0x0200
  45 #define __PF_RES_FIELD 0ULL
  46 #else /* CONFIG_64BIT */
  47 #define __FAIL_ADDR_MASK -4096L
  48 #define __SUBCODE_MASK 0x0600
  49 #define __PF_RES_FIELD 0x8000000000000000ULL
  50 #endif /* CONFIG_64BIT */
  51
  52 #define VM_FAULT_BADCONTEXT     0x010000
  53 #define VM_FAULT_BADMAP         0x020000
  54 #define VM_FAULT_BADACCESS      0x040000
  55
  56 static unsigned long store_indication;
  57
  58 void fault_init(void)
  59 {
  60         if (test_facility(2) && test_facility(75))
  61                 store_indication = 0xc00;
  62 }
  63
  64 static inline int notify_page_fault(struct pt_regs *regs)
  65 {
  66         int ret = 0;
  67
  68         /* kprobe_running() needs smp_processor_id() */
  69         if (kprobes_built_in() && !user_mode(regs)) {
  70                 preempt_disable();
  71                 if (kprobe_running() && kprobe_fault_handler(regs, 14))
  72                         ret = 1;
  73                 preempt_enable();
  74         }
  75         return ret;
  76 }
  77
  78
  79 /*
  80  * Unlock any spinlocks which will prevent us from getting the
  81  * message out.
  82  */
  83 void bust_spinlocks(int yes)
  84 {
  85         if (yes) {
  86                 oops_in_progress = 1;
  87         } else {
  88                 int loglevel_save = console_loglevel;
  89                 console_unblank();
  90                 oops_in_progress = 0;
  91                 /*
  92                  * OK, the message is on the console.  Now we call printk()
  93                  * without oops_in_progress set so that printk will give klogd
  94                  * a poke.  Hold onto your hats...
  95                  */
  96                 console_loglevel = 15;
  97                 printk(" ");
  98                 console_loglevel = loglevel_save;
  99         }
 100 }
 101
 102 /*
 103  * Returns the address space associated with the fault.
 104  * Returns 0 for kernel space and 1 for user space.
 105  */
 106 static inline int user_space_fault(unsigned long trans_exc_code)
 107 {
 108         /*
 109          * The lowest two bits of the translation exception
 110          * identification indicate which paging table was used.
 111          */
 112         trans_exc_code &= 3;
 113         if (trans_exc_code == 2)
 114                 /* Access via secondary space, set_fs setting decides */
 115                 return current->thread.mm_segment.ar4;
 116         if (user_mode == HOME_SPACE_MODE)
 117                 /* User space if the access has been done via home space. */
 118                 return trans_exc_code == 3;
 119         /*
 120          * If the user space is not the home space the kernel runs in home
 121          * space. Access via secondary space has already been covered,
 122          * access via primary space or access register is from user space
 123          * and access via home space is from the kernel.
 124          */
 125         return trans_exc_code != 3;
 126 }
 127
 128 static inline void report_user_fault(struct pt_regs *regs, long int_code,
 129                                      int signr, unsigned long address)
 130 {
 131         if ((task_pid_nr(current) > 1) && !show_unhandled_signals)
 132                 return;
 133         if (!unhandled_signal(current, signr))
 134                 return;
 135         if (!printk_ratelimit())
 136                 return;
 137         printk("User process fault: interruption code 0x%lX ", int_code);
 138         print_vma_addr(KERN_CONT "in ", regs->psw.addr & PSW_ADDR_INSN);
 139         printk("\n");
 140         printk("failing address: %lX\n", address);
 141         show_regs(regs);
 142 }
 143
 144 /*
 145  * Send SIGSEGV to task.  This is an external routine
 146  * to keep the stack usage of do_page_fault small.
 147  */
 148 static noinline void do_sigsegv(struct pt_regs *regs, long int_code,
 149                                 int si_code, unsigned long trans_exc_code)
 150 {
 151         struct siginfo si;
 152         unsigned long address;
 153
 154         address = trans_exc_code & __FAIL_ADDR_MASK;
 155         current->thread.prot_addr = address;
 156         current->thread.trap_no = int_code;
 157         report_user_fault(regs, int_code, SIGSEGV, address);
 158         si.si_signo = SIGSEGV;
 159         si.si_code = si_code;
 160         si.si_addr = (void __user *) address;
 161         force_sig_info(SIGSEGV, &si, current);
 162 }
 163
 164 static noinline void do_no_context(struct pt_regs *regs, long int_code,
 165                                    unsigned long trans_exc_code)
 166 {
 167         const struct exception_table_entry *fixup;
 168         unsigned long address;
 169
 170         /* Are we prepared to handle this kernel fault?  */
 171         fixup = search_exception_tables(regs->psw.addr & PSW_ADDR_INSN);
 172         if (fixup) {
 173                 regs->psw.addr = fixup->fixup | PSW_ADDR_AMODE;
 174                 return;
 175         }
 176
 177         /*
 178          * Oops. The kernel tried to access some bad page. We'll have to
 179          * terminate things with extreme prejudice.
 180          */
 181         address = trans_exc_code & __FAIL_ADDR_MASK;
 182         if (!user_space_fault(trans_exc_code))
 183                 printk(KERN_ALERT "Unable to handle kernel pointer dereference"
 184                        " at virtual kernel address %p\n", (void *)address);
 185         else
 186                 printk(KERN_ALERT "Unable to handle kernel paging request"
 187                        " at virtual user address %p\n", (void *)address);
 188
 189         die("Oops", regs, int_code);
 190         do_exit(SIGKILL);
 191 }
 192
 193 static noinline void do_low_address(struct pt_regs *regs, long int_code,
 194                                     unsigned long trans_exc_code)
 195 {
 196         /* Low-address protection hit in kernel mode means
 197            NULL pointer write access in kernel mode.  */
 198         if (regs->psw.mask & PSW_MASK_PSTATE) {
 199                 /* Low-address protection hit in user mode 'cannot happen'. */
 200                 die ("Low-address protection", regs, int_code);
 201                 do_exit(SIGKILL);
 202         }
 203
 204         do_no_context(regs, int_code, trans_exc_code);
 205 }
 206
 207 static noinline void do_sigbus(struct pt_regs *regs, long int_code,
 208                                unsigned long trans_exc_code)
 209 {
 210         struct task_struct *tsk = current;
 211         unsigned long address;
 212         struct siginfo si;
 213
 214         /*
 215          * Send a sigbus, regardless of whether we were in kernel
 216          * or user mode.
 217          */
 218         address = trans_exc_code & __FAIL_ADDR_MASK;
 219         tsk->thread.prot_addr = address;
 220         tsk->thread.trap_no = int_code;
 221         si.si_signo = SIGBUS;
 222         si.si_errno = 0;
 223         si.si_code = BUS_ADRERR;
 224         si.si_addr = (void __user *) address;
 225         force_sig_info(SIGBUS, &si, tsk);
 226 }
 227
 228 static noinline void do_fault_error(struct pt_regs *regs, long int_code,
 229                                     unsigned long trans_exc_code, int fault)
 230 {
 231         int si_code;
 232
 233         switch (fault) {
 234         case VM_FAULT_BADACCESS:
 235         case VM_FAULT_BADMAP:
 236                 /* Bad memory access. Check if it is kernel or user space. */
 237                 if (regs->psw.mask & PSW_MASK_PSTATE) {
 238                         /* User mode accesses just cause a SIGSEGV */
 239                         si_code = (fault == VM_FAULT_BADMAP) ?
 240                                 SEGV_MAPERR : SEGV_ACCERR;
 241                         do_sigsegv(regs, int_code, si_code, trans_exc_code);
 242                         return;
 243                 }
 244         case VM_FAULT_BADCONTEXT:
 245                 do_no_context(regs, int_code, trans_exc_code);
 246                 break;
 247         default: /* fault & VM_FAULT_ERROR */
 248                 if (fault & VM_FAULT_OOM) {
 249                         if (!(regs->psw.mask & PSW_MASK_PSTATE))
 250                                 do_no_context(regs, int_code, trans_exc_code);
 251                         else
 252                                 pagefault_out_of_memory();
 253                 } else if (fault & VM_FAULT_SIGBUS) {
 254                         /* Kernel mode? Handle exceptions or die */
 255                         if (!(regs->psw.mask & PSW_MASK_PSTATE))
 256                                 do_no_context(regs, int_code, trans_exc_code);
 257                         else
 258                                 do_sigbus(regs, int_code, trans_exc_code);
 259                 } else
 260                         BUG();
 261                 break;
 262         }
 263 }
 264
 265 /*
 266  * This routine handles page faults.  It determines the address,
 267  * and the problem, and then passes it off to one of the appropriate
 268  * routines.
 269  *
 270  * interruption code (int_code):
 271  *   04       Protection           ->  Write-Protection  (suprression)
 272  *   10       Segment translation  ->  Not present       (nullification)
 273  *   11       Page translation     ->  Not present       (nullification)
 274  *   3b       Region third trans.  ->  Not present       (nullification)
 275  */
 276 static inline int do_exception(struct pt_regs *regs, int access,
 277                                unsigned long trans_exc_code)
 278 {
 279         struct task_struct *tsk;
 280         struct mm_struct *mm;
 281         struct vm_area_struct *vma;
 282         unsigned long address;
 283         unsigned int flags;
 284         int fault;
 285
 286         if (notify_page_fault(regs))
 287                 return 0;
 288
 289         tsk = current;
 290         mm = tsk->mm;
 291
 292         /*
 293          * Verify that the fault happened in user space, that
 294          * we are not in an interrupt and that there is a
 295          * user context.
 296          */
 297         fault = VM_FAULT_BADCONTEXT;
 298         if (unlikely(!user_space_fault(trans_exc_code) || in_atomic() || !mm))
 299                 goto out;
 300
 301         address = trans_exc_code & __FAIL_ADDR_MASK;
 302         perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
 303         flags = FAULT_FLAG_ALLOW_RETRY;
 304         if (access == VM_WRITE || (trans_exc_code & store_indication) == 0x400)
 305                 flags |= FAULT_FLAG_WRITE;
 306         down_read(&mm->mmap_sem);
 307
 308 #ifdef CONFIG_PGSTE
 309         if (test_tsk_thread_flag(current, TIF_SIE) && S390_lowcore.gmap) {
 310                 address = gmap_fault(address,
 311                                      (struct gmap *) S390_lowcore.gmap);
 312                 if (address == -EFAULT) {
 313                         fault = VM_FAULT_BADMAP;
 314                         goto out_up;
 315                 }
 316                 if (address == -ENOMEM) {
 317                         fault = VM_FAULT_OOM;
 318                         goto out_up;
 319                 }
 320         }
 321 #endif
 322
 323 retry:
 324         fault = VM_FAULT_BADMAP;
 325         vma = find_vma(mm, address);
 326         if (!vma)
 327                 goto out_up;
 328
 329         if (unlikely(vma->vm_start > address)) {
 330                 if (!(vma->vm_flags & VM_GROWSDOWN))
 331                         goto out_up;
 332                 if (expand_stack(vma, address))
 333                         goto out_up;
 334         }
 335
 336         /*
 337          * Ok, we have a good vm_area for this memory access, so
 338          * we can handle it..
 339          */
 340         fault = VM_FAULT_BADACCESS;
 341         if (unlikely(!(vma->vm_flags & access)))
 342                 goto out_up;
 343
 344         if (is_vm_hugetlb_page(vma))
 345                 address &= HPAGE_MASK;
 346         /*
 347          * If for any reason at all we couldn't handle the fault,
 348          * make sure we exit gracefully rather than endlessly redo
 349          * the fault.
 350          */
 351         fault = handle_mm_fault(mm, vma, address, flags);
 352         if (unlikely(fault & VM_FAULT_ERROR))
 353                 goto out_up;
 354
 355         /*
 356          * Major/minor page fault accounting is only done on the
 357          * initial attempt. If we go through a retry, it is extremely
 358          * likely that the page will be found in page cache at that point.
 359          */
 360         if (flags & FAULT_FLAG_ALLOW_RETRY) {
 361                 if (fault & VM_FAULT_MAJOR) {
 362                         tsk->maj_flt++;
 363                         perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1,
 364                                       regs, address);
 365                 } else {
 366                         tsk->min_flt++;
 367                         perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, 1,
 368                                       regs, address);
 369                 }
 370                 if (fault & VM_FAULT_RETRY) {
 371                         /* Clear FAULT_FLAG_ALLOW_RETRY to avoid any risk
 372                          * of starvation. */
 373                         flags &= ~FAULT_FLAG_ALLOW_RETRY;
 374                         down_read(&mm->mmap_sem);
 375                         goto retry;
 376                 }
 377         }
 378         /*
 379          * The instruction that caused the program check will
 380          * be repeated. Don't signal single step via SIGTRAP.
 381          */
 382         clear_tsk_thread_flag(tsk, TIF_PER_TRAP);
 383         fault = 0;
 384 out_up:
 385         up_read(&mm->mmap_sem);
 386 out:
 387         return fault;
 388 }
 389
 390 void __kprobes do_protection_exception(struct pt_regs *regs, long pgm_int_code,
 391                                        unsigned long trans_exc_code)
 392 {
 393         int fault;
 394
 395         /* Protection exception is suppressing, decrement psw address. */
 396         regs->psw.addr -= (pgm_int_code >> 16);
 397         /*
 398          * Check for low-address protection.  This needs to be treated
 399          * as a special case because the translation exception code
 400          * field is not guaranteed to contain valid data in this case.
 401          */
 402         if (unlikely(!(trans_exc_code & 4))) {
 403                 do_low_address(regs, pgm_int_code, trans_exc_code);
 404                 return;
 405         }
 406         fault = do_exception(regs, VM_WRITE, trans_exc_code);
 407         if (unlikely(fault))
 408                 do_fault_error(regs, 4, trans_exc_code, fault);
 409 }
 410
 411 void __kprobes do_dat_exception(struct pt_regs *regs, long pgm_int_code,
 412                                 unsigned long trans_exc_code)
 413 {
 414         int access, fault;
 415
 416         access = VM_READ | VM_EXEC | VM_WRITE;
 417         fault = do_exception(regs, access, trans_exc_code);
 418         if (unlikely(fault))
 419                 do_fault_error(regs, pgm_int_code & 255, trans_exc_code, fault);
 420 }
 421
 422 #ifdef CONFIG_64BIT
 423 void __kprobes do_asce_exception(struct pt_regs *regs, long pgm_int_code,
 424                                  unsigned long trans_exc_code)
 425 {
 426         struct mm_struct *mm = current->mm;
 427         struct vm_area_struct *vma;
 428
 429         if (unlikely(!user_space_fault(trans_exc_code) || in_atomic() || !mm))
 430                 goto no_context;
 431
 432         down_read(&mm->mmap_sem);
 433         vma = find_vma(mm, trans_exc_code & __FAIL_ADDR_MASK);
 434         up_read(&mm->mmap_sem);
 435
 436         if (vma) {
 437                 update_mm(mm, current);
 438                 return;
 439         }
 440
 441         /* User mode accesses just cause a SIGSEGV */
 442         if (regs->psw.mask & PSW_MASK_PSTATE) {
 443                 do_sigsegv(regs, pgm_int_code, SEGV_MAPERR, trans_exc_code);
 444                 return;
 445         }
 446
 447 no_context:
 448         do_no_context(regs, pgm_int_code, trans_exc_code);
 449 }
 450 #endif
 451
 452 int __handle_fault(unsigned long uaddr, unsigned long pgm_int_code, int write)
 453 {
 454         struct pt_regs regs;
 455         int access, fault;
 456
 457         regs.psw.mask = psw_kernel_bits;
 458         if (!irqs_disabled())
 459                 regs.psw.mask |= PSW_MASK_IO | PSW_MASK_EXT;
 460         regs.psw.addr = (unsigned long) __builtin_return_address(0);
 461         regs.psw.addr |= PSW_ADDR_AMODE;
 462         uaddr &= PAGE_MASK;
 463         access = write ? VM_WRITE : VM_READ;
 464         fault = do_exception(&regs, access, uaddr | 2);
 465         if (unlikely(fault)) {
 466                 if (fault & VM_FAULT_OOM)
 467                         return -EFAULT;
 468                 else if (fault & VM_FAULT_SIGBUS)
 469                         do_sigbus(&regs, pgm_int_code, uaddr);
 470         }
 471         return fault ? -EFAULT : 0;
 472 }
 473
 474 #ifdef CONFIG_PFAULT
 475 /*
 476  * 'pfault' pseudo page faults routines.
 477  */
 478 static int pfault_disable;
 479
 480 static int __init nopfault(char *str)
 481 {
 482         pfault_disable = 1;
 483         return 1;
 484 }
 485
 486 __setup("nopfault", nopfault);
 487
 488 struct pfault_refbk {
 489         u16 refdiagc;
 490         u16 reffcode;
 491         u16 refdwlen;
 492         u16 refversn;
 493         u64 refgaddr;
 494         u64 refselmk;
 495         u64 refcmpmk;
 496         u64 reserved;
 497 } __attribute__ ((packed, aligned(8)));
 498
 499 int pfault_init(void)
 500 {
 501         struct pfault_refbk refbk = {
 502                 .refdiagc = 0x258,
 503                 .reffcode = 0,
 504                 .refdwlen = 5,
 505                 .refversn = 2,
 506                 .refgaddr = __LC_CURRENT_PID,
 507                 .refselmk = 1ULL << 48,
 508                 .refcmpmk = 1ULL << 48,
 509                 .reserved = __PF_RES_FIELD };
 510         int rc;
 511
 512         if (!MACHINE_IS_VM || pfault_disable)
 513                 return -1;
 514         asm volatile(
 515                 "       diag    %1,%0,0x258\n"
 516                 "0:     j       2f\n"
 517                 "1:     la      %0,8\n"
 518                 "2:\n"
 519                 EX_TABLE(0b,1b)
 520                 : "=d" (rc) : "a" (&refbk), "m" (refbk) : "cc");
 521         return rc;
 522 }
 523
 524 void pfault_fini(void)
 525 {
 526         struct pfault_refbk refbk = {
 527                 .refdiagc = 0x258,
 528                 .reffcode = 1,
 529                 .refdwlen = 5,
 530                 .refversn = 2,
 531         };
 532
 533         if (!MACHINE_IS_VM || pfault_disable)
 534                 return;
 535         asm volatile(
 536                 "       diag    %0,0,0x258\n"
 537                 "0:\n"
 538                 EX_TABLE(0b,0b)
 539                 : : "a" (&refbk), "m" (refbk) : "cc");
 540 }
 541
 542 static DEFINE_SPINLOCK(pfault_lock);
 543 static LIST_HEAD(pfault_list);
 544
 545 static void pfault_interrupt(unsigned int ext_int_code,
 546                              unsigned int param32, unsigned long param64)
 547 {
 548         struct task_struct *tsk;
 549         __u16 subcode;
 550         pid_t pid;
 551
 552         /*
 553          * Get the external interruption subcode & pfault
 554          * initial/completion signal bit. VM stores this
 555          * in the 'cpu address' field associated with the
 556          * external interrupt.
 557          */
 558         subcode = ext_int_code >> 16;
 559         if ((subcode & 0xff00) != __SUBCODE_MASK)
 560                 return;
 561         kstat_cpu(smp_processor_id()).irqs[EXTINT_PFL]++;
 562         if (subcode & 0x0080) {
 563                 /* Get the token (= pid of the affected task). */
 564                 pid = sizeof(void *) == 4 ? param32 : param64;
 565                 rcu_read_lock();
 566                 tsk = find_task_by_pid_ns(pid, &init_pid_ns);
 567                 if (tsk)
 568                         get_task_struct(tsk);
 569                 rcu_read_unlock();
 570                 if (!tsk)
 571                         return;
 572         } else {
 573                 tsk = current;
 574         }
 575         spin_lock(&pfault_lock);
 576         if (subcode & 0x0080) {
 577                 /* signal bit is set -> a page has been swapped in by VM */
 578                 if (tsk->thread.pfault_wait == 1) {
 579                         /* Initial interrupt was faster than the completion
 580                          * interrupt. pfault_wait is valid. Set pfault_wait
 581                          * back to zero and wake up the process. This can
 582                          * safely be done because the task is still sleeping
 583                          * and can't produce new pfaults. */
 584                         tsk->thread.pfault_wait = 0;
 585                         list_del(&tsk->thread.list);
 586                         wake_up_process(tsk);
 587                 } else {
 588                         /* Completion interrupt was faster than initial
 589                          * interrupt. Set pfault_wait to -1 so the initial
 590                          * interrupt doesn't put the task to sleep. */
 591                         tsk->thread.pfault_wait = -1;
 592                 }
 593                 put_task_struct(tsk);
 594         } else {
 595                 /* signal bit not set -> a real page is missing. */
 596                 if (tsk->thread.pfault_wait == -1) {
 597                         /* Completion interrupt was faster than the initial
 598                          * interrupt (pfault_wait == -1). Set pfault_wait
 599                          * back to zero and exit. */
 600                         tsk->thread.pfault_wait = 0;
 601                 } else {
 602                         /* Initial interrupt arrived before completion
 603                          * interrupt. Let the task sleep. */
 604                         tsk->thread.pfault_wait = 1;
 605                         list_add(&tsk->thread.list, &pfault_list);
 606                         set_task_state(tsk, TASK_UNINTERRUPTIBLE);
 607                         set_tsk_need_resched(tsk);
 608                 }
 609         }
 610         spin_unlock(&pfault_lock);
 611 }
 612
 613 static int __cpuinit pfault_cpu_notify(struct notifier_block *self,
 614                                        unsigned long action, void *hcpu)
 615 {
 616         struct thread_struct *thread, *next;
 617         struct task_struct *tsk;
 618
 619         switch (action) {
 620         case CPU_DEAD:
 621         case CPU_DEAD_FROZEN:
 622                 spin_lock_irq(&pfault_lock);
 623                 list_for_each_entry_safe(thread, next, &pfault_list, list) {
 624                         thread->pfault_wait = 0;
 625                         list_del(&thread->list);
 626                         tsk = container_of(thread, struct task_struct, thread);
 627                         wake_up_process(tsk);
 628                 }
 629                 spin_unlock_irq(&pfault_lock);
 630                 break;
 631         default:
 632                 break;
 633         }
 634         return NOTIFY_OK;
 635 }
 636
 637 static int __init pfault_irq_init(void)
 638 {
 639         int rc;
 640
 641         if (!MACHINE_IS_VM)
 642                 return 0;
 643         rc = register_external_interrupt(0x2603, pfault_interrupt);
 644         if (rc)
 645                 goto out_extint;
 646         rc = pfault_init() == 0 ? 0 : -EOPNOTSUPP;
 647         if (rc)
 648                 goto out_pfault;
 649         service_subclass_irq_register();
 650         hotcpu_notifier(pfault_cpu_notify, 0);
 651         return 0;
 652
 653 out_pfault:
 654         unregister_external_interrupt(0x2603, pfault_interrupt);
 655 out_extint:
 656         pfault_disable = 1;
 657         return rc;
 658 }
 659 early_initcall(pfault_irq_init);
 660
 661 #endif /* CONFIG_PFAULT */