1 /* 2 * S390 version 3 * Copyright IBM Corp. 1999 4 * Author(s): Hartmut Penner (hp@de.ibm.com) 5 * Ulrich Weigand (uweigand@de.ibm.com) 6 * 7 * Derived from "arch/i386/mm/fault.c" 8 * Copyright (C) 1995 Linus Torvalds 9 */ 10 11 #include <linux/kernel_stat.h> 12 #include <linux/perf_event.h> 13 #include <linux/signal.h> 14 #include <linux/sched.h> 15 #include <linux/kernel.h> 16 #include <linux/errno.h> 17 #include <linux/string.h> 18 #include <linux/types.h> 19 #include <linux/ptrace.h> 20 #include <linux/mman.h> 21 #include <linux/mm.h> 22 #include <linux/compat.h> 23 #include <linux/smp.h> 24 #include <linux/kdebug.h> 25 #include <linux/init.h> 26 #include <linux/console.h> 27 #include <linux/module.h> 28 #include <linux/hardirq.h> 29 #include <linux/kprobes.h> 30 #include <linux/uaccess.h> 31 #include <linux/hugetlb.h> 32 #include <asm/asm-offsets.h> 33 #include <asm/diag.h> 34 #include <asm/pgtable.h> 35 #include <asm/irq.h> 36 #include <asm/mmu_context.h> 37 #include <asm/facility.h> 38 #include "../kernel/entry.h" 39 40 #define __FAIL_ADDR_MASK -4096L 41 #define __SUBCODE_MASK 0x0600 42 #define __PF_RES_FIELD 0x8000000000000000ULL 43 44 #define VM_FAULT_BADCONTEXT 0x010000 45 #define VM_FAULT_BADMAP 0x020000 46 #define VM_FAULT_BADACCESS 0x040000 47 #define VM_FAULT_SIGNAL 0x080000 48 #define VM_FAULT_PFAULT 0x100000 49 50 static unsigned long store_indication __read_mostly; 51 52 static int __init fault_init(void) 53 { 54 if (test_facility(75)) 55 store_indication = 0xc00; 56 return 0; 57 } 58 early_initcall(fault_init); 59 60 static inline int notify_page_fault(struct pt_regs *regs) 61 { 62 int ret = 0; 63 64 /* kprobe_running() needs smp_processor_id() */ 65 if (kprobes_built_in() && !user_mode(regs)) { 66 preempt_disable(); 67 if (kprobe_running() && kprobe_fault_handler(regs, 14)) 68 ret = 1; 69 preempt_enable(); 70 } 71 return ret; 72 } 73 74 75 /* 76 * Unlock any spinlocks which will prevent us from getting the 77 * message out. 78 */ 79 void bust_spinlocks(int yes) 80 { 81 if (yes) { 82 oops_in_progress = 1; 83 } else { 84 int loglevel_save = console_loglevel; 85 console_unblank(); 86 oops_in_progress = 0; 87 /* 88 * OK, the message is on the console. Now we call printk() 89 * without oops_in_progress set so that printk will give klogd 90 * a poke. Hold onto your hats... 91 */ 92 console_loglevel = 15; 93 printk(" "); 94 console_loglevel = loglevel_save; 95 } 96 } 97 98 /* 99 * Returns the address space associated with the fault. 100 * Returns 0 for kernel space and 1 for user space. 101 */ 102 static inline int user_space_fault(struct pt_regs *regs) 103 { 104 unsigned long trans_exc_code; 105 106 /* 107 * The lowest two bits of the translation exception 108 * identification indicate which paging table was used. 109 */ 110 trans_exc_code = regs->int_parm_long & 3; 111 if (trans_exc_code == 3) /* home space -> kernel */ 112 return 0; 113 if (user_mode(regs)) 114 return 1; 115 if (trans_exc_code == 2) /* secondary space -> set_fs */ 116 return current->thread.mm_segment.ar4; 117 if (current->flags & PF_VCPU) 118 return 1; 119 return 0; 120 } 121 122 static int bad_address(void *p) 123 { 124 unsigned long dummy; 125 126 return probe_kernel_address((unsigned long *)p, dummy); 127 } 128 129 static void dump_pagetable(unsigned long asce, unsigned long address) 130 { 131 unsigned long *table = __va(asce & PAGE_MASK); 132 133 pr_alert("AS:%016lx ", asce); 134 switch (asce & _ASCE_TYPE_MASK) { 135 case _ASCE_TYPE_REGION1: 136 table = table + ((address >> 53) & 0x7ff); 137 if (bad_address(table)) 138 goto bad; 139 pr_cont("R1:%016lx ", *table); 140 if (*table & _REGION_ENTRY_INVALID) 141 goto out; 142 table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN); 143 /* fallthrough */ 144 case _ASCE_TYPE_REGION2: 145 table = table + ((address >> 42) & 0x7ff); 146 if (bad_address(table)) 147 goto bad; 148 pr_cont("R2:%016lx ", *table); 149 if (*table & _REGION_ENTRY_INVALID) 150 goto out; 151 table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN); 152 /* fallthrough */ 153 case _ASCE_TYPE_REGION3: 154 table = table + ((address >> 31) & 0x7ff); 155 if (bad_address(table)) 156 goto bad; 157 pr_cont("R3:%016lx ", *table); 158 if (*table & (_REGION_ENTRY_INVALID | _REGION3_ENTRY_LARGE)) 159 goto out; 160 table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN); 161 /* fallthrough */ 162 case _ASCE_TYPE_SEGMENT: 163 table = table + ((address >> 20) & 0x7ff); 164 if (bad_address(table)) 165 goto bad; 166 pr_cont("S:%016lx ", *table); 167 if (*table & (_SEGMENT_ENTRY_INVALID | _SEGMENT_ENTRY_LARGE)) 168 goto out; 169 table = (unsigned long *)(*table & _SEGMENT_ENTRY_ORIGIN); 170 } 171 table = table + ((address >> 12) & 0xff); 172 if (bad_address(table)) 173 goto bad; 174 pr_cont("P:%016lx ", *table); 175 out: 176 pr_cont("\n"); 177 return; 178 bad: 179 pr_cont("BAD\n"); 180 } 181 182 static void dump_fault_info(struct pt_regs *regs) 183 { 184 unsigned long asce; 185 186 pr_alert("Fault in "); 187 switch (regs->int_parm_long & 3) { 188 case 3: 189 pr_cont("home space "); 190 break; 191 case 2: 192 pr_cont("secondary space "); 193 break; 194 case 1: 195 pr_cont("access register "); 196 break; 197 case 0: 198 pr_cont("primary space "); 199 break; 200 } 201 pr_cont("mode while using "); 202 if (!user_space_fault(regs)) { 203 asce = S390_lowcore.kernel_asce; 204 pr_cont("kernel "); 205 } 206 #ifdef CONFIG_PGSTE 207 else if ((current->flags & PF_VCPU) && S390_lowcore.gmap) { 208 struct gmap *gmap = (struct gmap *)S390_lowcore.gmap; 209 asce = gmap->asce; 210 pr_cont("gmap "); 211 } 212 #endif 213 else { 214 asce = S390_lowcore.user_asce; 215 pr_cont("user "); 216 } 217 pr_cont("ASCE.\n"); 218 dump_pagetable(asce, regs->int_parm_long & __FAIL_ADDR_MASK); 219 } 220 221 static inline void report_user_fault(struct pt_regs *regs, long signr) 222 { 223 if ((task_pid_nr(current) > 1) && !show_unhandled_signals) 224 return; 225 if (!unhandled_signal(current, signr)) 226 return; 227 if (!printk_ratelimit()) 228 return; 229 printk(KERN_ALERT "User process fault: interruption code %04x ilc:%d ", 230 regs->int_code & 0xffff, regs->int_code >> 17); 231 print_vma_addr(KERN_CONT "in ", regs->psw.addr); 232 printk(KERN_CONT "\n"); 233 printk(KERN_ALERT "failing address: %016lx TEID: %016lx\n", 234 regs->int_parm_long & __FAIL_ADDR_MASK, regs->int_parm_long); 235 dump_fault_info(regs); 236 show_regs(regs); 237 } 238 239 /* 240 * Send SIGSEGV to task. This is an external routine 241 * to keep the stack usage of do_page_fault small. 242 */ 243 static noinline void do_sigsegv(struct pt_regs *regs, int si_code) 244 { 245 struct siginfo si; 246 247 report_user_fault(regs, SIGSEGV); 248 si.si_signo = SIGSEGV; 249 si.si_code = si_code; 250 si.si_addr = (void __user *)(regs->int_parm_long & __FAIL_ADDR_MASK); 251 force_sig_info(SIGSEGV, &si, current); 252 } 253 254 static noinline void do_no_context(struct pt_regs *regs) 255 { 256 const struct exception_table_entry *fixup; 257 258 /* Are we prepared to handle this kernel fault? */ 259 fixup = search_exception_tables(regs->psw.addr); 260 if (fixup) { 261 regs->psw.addr = extable_fixup(fixup); 262 return; 263 } 264 265 /* 266 * Oops. The kernel tried to access some bad page. We'll have to 267 * terminate things with extreme prejudice. 268 */ 269 if (!user_space_fault(regs)) 270 printk(KERN_ALERT "Unable to handle kernel pointer dereference" 271 " in virtual kernel address space\n"); 272 else 273 printk(KERN_ALERT "Unable to handle kernel paging request" 274 " in virtual user address space\n"); 275 printk(KERN_ALERT "failing address: %016lx TEID: %016lx\n", 276 regs->int_parm_long & __FAIL_ADDR_MASK, regs->int_parm_long); 277 dump_fault_info(regs); 278 die(regs, "Oops"); 279 do_exit(SIGKILL); 280 } 281 282 static noinline void do_low_address(struct pt_regs *regs) 283 { 284 /* Low-address protection hit in kernel mode means 285 NULL pointer write access in kernel mode. */ 286 if (regs->psw.mask & PSW_MASK_PSTATE) { 287 /* Low-address protection hit in user mode 'cannot happen'. */ 288 die (regs, "Low-address protection"); 289 do_exit(SIGKILL); 290 } 291 292 do_no_context(regs); 293 } 294 295 static noinline void do_sigbus(struct pt_regs *regs) 296 { 297 struct task_struct *tsk = current; 298 struct siginfo si; 299 300 /* 301 * Send a sigbus, regardless of whether we were in kernel 302 * or user mode. 303 */ 304 si.si_signo = SIGBUS; 305 si.si_errno = 0; 306 si.si_code = BUS_ADRERR; 307 si.si_addr = (void __user *)(regs->int_parm_long & __FAIL_ADDR_MASK); 308 force_sig_info(SIGBUS, &si, tsk); 309 } 310 311 static noinline void do_fault_error(struct pt_regs *regs, int fault) 312 { 313 int si_code; 314 315 switch (fault) { 316 case VM_FAULT_BADACCESS: 317 case VM_FAULT_BADMAP: 318 /* Bad memory access. Check if it is kernel or user space. */ 319 if (user_mode(regs)) { 320 /* User mode accesses just cause a SIGSEGV */ 321 si_code = (fault == VM_FAULT_BADMAP) ? 322 SEGV_MAPERR : SEGV_ACCERR; 323 do_sigsegv(regs, si_code); 324 return; 325 } 326 case VM_FAULT_BADCONTEXT: 327 case VM_FAULT_PFAULT: 328 do_no_context(regs); 329 break; 330 case VM_FAULT_SIGNAL: 331 if (!user_mode(regs)) 332 do_no_context(regs); 333 break; 334 default: /* fault & VM_FAULT_ERROR */ 335 if (fault & VM_FAULT_OOM) { 336 if (!user_mode(regs)) 337 do_no_context(regs); 338 else 339 pagefault_out_of_memory(); 340 } else if (fault & VM_FAULT_SIGSEGV) { 341 /* Kernel mode? Handle exceptions or die */ 342 if (!user_mode(regs)) 343 do_no_context(regs); 344 else 345 do_sigsegv(regs, SEGV_MAPERR); 346 } else if (fault & VM_FAULT_SIGBUS) { 347 /* Kernel mode? Handle exceptions or die */ 348 if (!user_mode(regs)) 349 do_no_context(regs); 350 else 351 do_sigbus(regs); 352 } else 353 BUG(); 354 break; 355 } 356 } 357 358 /* 359 * This routine handles page faults. It determines the address, 360 * and the problem, and then passes it off to one of the appropriate 361 * routines. 362 * 363 * interruption code (int_code): 364 * 04 Protection -> Write-Protection (suprression) 365 * 10 Segment translation -> Not present (nullification) 366 * 11 Page translation -> Not present (nullification) 367 * 3b Region third trans. -> Not present (nullification) 368 */ 369 static inline int do_exception(struct pt_regs *regs, int access) 370 { 371 #ifdef CONFIG_PGSTE 372 struct gmap *gmap; 373 #endif 374 struct task_struct *tsk; 375 struct mm_struct *mm; 376 struct vm_area_struct *vma; 377 unsigned long trans_exc_code; 378 unsigned long address; 379 unsigned int flags; 380 int fault; 381 382 tsk = current; 383 /* 384 * The instruction that caused the program check has 385 * been nullified. Don't signal single step via SIGTRAP. 386 */ 387 clear_pt_regs_flag(regs, PIF_PER_TRAP); 388 389 if (notify_page_fault(regs)) 390 return 0; 391 392 mm = tsk->mm; 393 trans_exc_code = regs->int_parm_long; 394 395 /* 396 * Verify that the fault happened in user space, that 397 * we are not in an interrupt and that there is a 398 * user context. 399 */ 400 fault = VM_FAULT_BADCONTEXT; 401 if (unlikely(!user_space_fault(regs) || faulthandler_disabled() || !mm)) 402 goto out; 403 404 address = trans_exc_code & __FAIL_ADDR_MASK; 405 perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address); 406 flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE; 407 if (user_mode(regs)) 408 flags |= FAULT_FLAG_USER; 409 if (access == VM_WRITE || (trans_exc_code & store_indication) == 0x400) 410 flags |= FAULT_FLAG_WRITE; 411 down_read(&mm->mmap_sem); 412 413 #ifdef CONFIG_PGSTE 414 gmap = (current->flags & PF_VCPU) ? 415 (struct gmap *) S390_lowcore.gmap : NULL; 416 if (gmap) { 417 current->thread.gmap_addr = address; 418 address = __gmap_translate(gmap, address); 419 if (address == -EFAULT) { 420 fault = VM_FAULT_BADMAP; 421 goto out_up; 422 } 423 if (gmap->pfault_enabled) 424 flags |= FAULT_FLAG_RETRY_NOWAIT; 425 } 426 #endif 427 428 retry: 429 fault = VM_FAULT_BADMAP; 430 vma = find_vma(mm, address); 431 if (!vma) 432 goto out_up; 433 434 if (unlikely(vma->vm_start > address)) { 435 if (!(vma->vm_flags & VM_GROWSDOWN)) 436 goto out_up; 437 if (expand_stack(vma, address)) 438 goto out_up; 439 } 440 441 /* 442 * Ok, we have a good vm_area for this memory access, so 443 * we can handle it.. 444 */ 445 fault = VM_FAULT_BADACCESS; 446 if (unlikely(!(vma->vm_flags & access))) 447 goto out_up; 448 449 if (is_vm_hugetlb_page(vma)) 450 address &= HPAGE_MASK; 451 /* 452 * If for any reason at all we couldn't handle the fault, 453 * make sure we exit gracefully rather than endlessly redo 454 * the fault. 455 */ 456 fault = handle_mm_fault(mm, vma, address, flags); 457 /* No reason to continue if interrupted by SIGKILL. */ 458 if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current)) { 459 fault = VM_FAULT_SIGNAL; 460 goto out; 461 } 462 if (unlikely(fault & VM_FAULT_ERROR)) 463 goto out_up; 464 465 /* 466 * Major/minor page fault accounting is only done on the 467 * initial attempt. If we go through a retry, it is extremely 468 * likely that the page will be found in page cache at that point. 469 */ 470 if (flags & FAULT_FLAG_ALLOW_RETRY) { 471 if (fault & VM_FAULT_MAJOR) { 472 tsk->maj_flt++; 473 perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1, 474 regs, address); 475 } else { 476 tsk->min_flt++; 477 perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, 1, 478 regs, address); 479 } 480 if (fault & VM_FAULT_RETRY) { 481 #ifdef CONFIG_PGSTE 482 if (gmap && (flags & FAULT_FLAG_RETRY_NOWAIT)) { 483 /* FAULT_FLAG_RETRY_NOWAIT has been set, 484 * mmap_sem has not been released */ 485 current->thread.gmap_pfault = 1; 486 fault = VM_FAULT_PFAULT; 487 goto out_up; 488 } 489 #endif 490 /* Clear FAULT_FLAG_ALLOW_RETRY to avoid any risk 491 * of starvation. */ 492 flags &= ~(FAULT_FLAG_ALLOW_RETRY | 493 FAULT_FLAG_RETRY_NOWAIT); 494 flags |= FAULT_FLAG_TRIED; 495 down_read(&mm->mmap_sem); 496 goto retry; 497 } 498 } 499 #ifdef CONFIG_PGSTE 500 if (gmap) { 501 address = __gmap_link(gmap, current->thread.gmap_addr, 502 address); 503 if (address == -EFAULT) { 504 fault = VM_FAULT_BADMAP; 505 goto out_up; 506 } 507 if (address == -ENOMEM) { 508 fault = VM_FAULT_OOM; 509 goto out_up; 510 } 511 } 512 #endif 513 fault = 0; 514 out_up: 515 up_read(&mm->mmap_sem); 516 out: 517 return fault; 518 } 519 520 void do_protection_exception(struct pt_regs *regs) 521 { 522 unsigned long trans_exc_code; 523 int fault; 524 525 trans_exc_code = regs->int_parm_long; 526 /* 527 * Protection exceptions are suppressing, decrement psw address. 528 * The exception to this rule are aborted transactions, for these 529 * the PSW already points to the correct location. 530 */ 531 if (!(regs->int_code & 0x200)) 532 regs->psw.addr = __rewind_psw(regs->psw, regs->int_code >> 16); 533 /* 534 * Check for low-address protection. This needs to be treated 535 * as a special case because the translation exception code 536 * field is not guaranteed to contain valid data in this case. 537 */ 538 if (unlikely(!(trans_exc_code & 4))) { 539 do_low_address(regs); 540 return; 541 } 542 fault = do_exception(regs, VM_WRITE); 543 if (unlikely(fault)) 544 do_fault_error(regs, fault); 545 } 546 NOKPROBE_SYMBOL(do_protection_exception); 547 548 void do_dat_exception(struct pt_regs *regs) 549 { 550 int access, fault; 551 552 access = VM_READ | VM_EXEC | VM_WRITE; 553 fault = do_exception(regs, access); 554 if (unlikely(fault)) 555 do_fault_error(regs, fault); 556 } 557 NOKPROBE_SYMBOL(do_dat_exception); 558 559 #ifdef CONFIG_PFAULT 560 /* 561 * 'pfault' pseudo page faults routines. 562 */ 563 static int pfault_disable; 564 565 static int __init nopfault(char *str) 566 { 567 pfault_disable = 1; 568 return 1; 569 } 570 571 __setup("nopfault", nopfault); 572 573 struct pfault_refbk { 574 u16 refdiagc; 575 u16 reffcode; 576 u16 refdwlen; 577 u16 refversn; 578 u64 refgaddr; 579 u64 refselmk; 580 u64 refcmpmk; 581 u64 reserved; 582 } __attribute__ ((packed, aligned(8))); 583 584 int pfault_init(void) 585 { 586 struct pfault_refbk refbk = { 587 .refdiagc = 0x258, 588 .reffcode = 0, 589 .refdwlen = 5, 590 .refversn = 2, 591 .refgaddr = __LC_LPP, 592 .refselmk = 1ULL << 48, 593 .refcmpmk = 1ULL << 48, 594 .reserved = __PF_RES_FIELD }; 595 int rc; 596 597 if (pfault_disable) 598 return -1; 599 diag_stat_inc(DIAG_STAT_X258); 600 asm volatile( 601 " diag %1,%0,0x258\n" 602 "0: j 2f\n" 603 "1: la %0,8\n" 604 "2:\n" 605 EX_TABLE(0b,1b) 606 : "=d" (rc) : "a" (&refbk), "m" (refbk) : "cc"); 607 return rc; 608 } 609 610 void pfault_fini(void) 611 { 612 struct pfault_refbk refbk = { 613 .refdiagc = 0x258, 614 .reffcode = 1, 615 .refdwlen = 5, 616 .refversn = 2, 617 }; 618 619 if (pfault_disable) 620 return; 621 diag_stat_inc(DIAG_STAT_X258); 622 asm volatile( 623 " diag %0,0,0x258\n" 624 "0:\n" 625 EX_TABLE(0b,0b) 626 : : "a" (&refbk), "m" (refbk) : "cc"); 627 } 628 629 static DEFINE_SPINLOCK(pfault_lock); 630 static LIST_HEAD(pfault_list); 631 632 static void pfault_interrupt(struct ext_code ext_code, 633 unsigned int param32, unsigned long param64) 634 { 635 struct task_struct *tsk; 636 __u16 subcode; 637 pid_t pid; 638 639 /* 640 * Get the external interruption subcode & pfault 641 * initial/completion signal bit. VM stores this 642 * in the 'cpu address' field associated with the 643 * external interrupt. 644 */ 645 subcode = ext_code.subcode; 646 if ((subcode & 0xff00) != __SUBCODE_MASK) 647 return; 648 inc_irq_stat(IRQEXT_PFL); 649 /* Get the token (= pid of the affected task). */ 650 pid = param64 & LPP_PFAULT_PID_MASK; 651 rcu_read_lock(); 652 tsk = find_task_by_pid_ns(pid, &init_pid_ns); 653 if (tsk) 654 get_task_struct(tsk); 655 rcu_read_unlock(); 656 if (!tsk) 657 return; 658 spin_lock(&pfault_lock); 659 if (subcode & 0x0080) { 660 /* signal bit is set -> a page has been swapped in by VM */ 661 if (tsk->thread.pfault_wait == 1) { 662 /* Initial interrupt was faster than the completion 663 * interrupt. pfault_wait is valid. Set pfault_wait 664 * back to zero and wake up the process. This can 665 * safely be done because the task is still sleeping 666 * and can't produce new pfaults. */ 667 tsk->thread.pfault_wait = 0; 668 list_del(&tsk->thread.list); 669 wake_up_process(tsk); 670 put_task_struct(tsk); 671 } else { 672 /* Completion interrupt was faster than initial 673 * interrupt. Set pfault_wait to -1 so the initial 674 * interrupt doesn't put the task to sleep. 675 * If the task is not running, ignore the completion 676 * interrupt since it must be a leftover of a PFAULT 677 * CANCEL operation which didn't remove all pending 678 * completion interrupts. */ 679 if (tsk->state == TASK_RUNNING) 680 tsk->thread.pfault_wait = -1; 681 } 682 } else { 683 /* signal bit not set -> a real page is missing. */ 684 if (WARN_ON_ONCE(tsk != current)) 685 goto out; 686 if (tsk->thread.pfault_wait == 1) { 687 /* Already on the list with a reference: put to sleep */ 688 __set_task_state(tsk, TASK_UNINTERRUPTIBLE); 689 set_tsk_need_resched(tsk); 690 } else if (tsk->thread.pfault_wait == -1) { 691 /* Completion interrupt was faster than the initial 692 * interrupt (pfault_wait == -1). Set pfault_wait 693 * back to zero and exit. */ 694 tsk->thread.pfault_wait = 0; 695 } else { 696 /* Initial interrupt arrived before completion 697 * interrupt. Let the task sleep. 698 * An extra task reference is needed since a different 699 * cpu may set the task state to TASK_RUNNING again 700 * before the scheduler is reached. */ 701 get_task_struct(tsk); 702 tsk->thread.pfault_wait = 1; 703 list_add(&tsk->thread.list, &pfault_list); 704 __set_task_state(tsk, TASK_UNINTERRUPTIBLE); 705 set_tsk_need_resched(tsk); 706 } 707 } 708 out: 709 spin_unlock(&pfault_lock); 710 put_task_struct(tsk); 711 } 712 713 static int pfault_cpu_notify(struct notifier_block *self, unsigned long action, 714 void *hcpu) 715 { 716 struct thread_struct *thread, *next; 717 struct task_struct *tsk; 718 719 switch (action & ~CPU_TASKS_FROZEN) { 720 case CPU_DEAD: 721 spin_lock_irq(&pfault_lock); 722 list_for_each_entry_safe(thread, next, &pfault_list, list) { 723 thread->pfault_wait = 0; 724 list_del(&thread->list); 725 tsk = container_of(thread, struct task_struct, thread); 726 wake_up_process(tsk); 727 put_task_struct(tsk); 728 } 729 spin_unlock_irq(&pfault_lock); 730 break; 731 default: 732 break; 733 } 734 return NOTIFY_OK; 735 } 736 737 static int __init pfault_irq_init(void) 738 { 739 int rc; 740 741 rc = register_external_irq(EXT_IRQ_CP_SERVICE, pfault_interrupt); 742 if (rc) 743 goto out_extint; 744 rc = pfault_init() == 0 ? 0 : -EOPNOTSUPP; 745 if (rc) 746 goto out_pfault; 747 irq_subclass_register(IRQ_SUBCLASS_SERVICE_SIGNAL); 748 hotcpu_notifier(pfault_cpu_notify, 0); 749 return 0; 750 751 out_pfault: 752 unregister_external_irq(EXT_IRQ_CP_SERVICE, pfault_interrupt); 753 out_extint: 754 pfault_disable = 1; 755 return rc; 756 } 757 early_initcall(pfault_irq_init); 758 759 #endif /* CONFIG_PFAULT */ 760