| 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/perf_counter.h> |
| 14 | #include <linux/signal.h> |
| 15 | #include <linux/sched.h> |
| 16 | #include <linux/kernel.h> |
| 17 | #include <linux/errno.h> |
| 18 | #include <linux/string.h> |
| 19 | #include <linux/types.h> |
| 20 | #include <linux/ptrace.h> |
| 21 | #include <linux/mman.h> |
| 22 | #include <linux/mm.h> |
| 23 | #include <linux/compat.h> |
| 24 | #include <linux/smp.h> |
| 25 | #include <linux/kdebug.h> |
| 26 | #include <linux/init.h> |
| 27 | #include <linux/console.h> |
| 28 | #include <linux/module.h> |
| 29 | #include <linux/hardirq.h> |
| 30 | #include <linux/kprobes.h> |
| 31 | #include <linux/uaccess.h> |
| 32 | #include <linux/hugetlb.h> |
| 33 | #include <asm/system.h> |
| 34 | #include <asm/pgtable.h> |
| 35 | #include <asm/s390_ext.h> |
| 36 | #include <asm/mmu_context.h> |
| 37 | #include "../kernel/entry.h" |
| 38 | |
| 39 | #ifndef CONFIG_64BIT |
| 40 | #define __FAIL_ADDR_MASK 0x7ffff000 |
| 41 | #define __FIXUP_MASK 0x7fffffff |
| 42 | #define __SUBCODE_MASK 0x0200 |
| 43 | #define __PF_RES_FIELD 0ULL |
| 44 | #else /* CONFIG_64BIT */ |
| 45 | #define __FAIL_ADDR_MASK -4096L |
| 46 | #define __FIXUP_MASK ~0L |
| 47 | #define __SUBCODE_MASK 0x0600 |
| 48 | #define __PF_RES_FIELD 0x8000000000000000ULL |
| 49 | #endif /* CONFIG_64BIT */ |
| 50 | |
| 51 | #ifdef CONFIG_SYSCTL |
| 52 | extern int sysctl_userprocess_debug; |
| 53 | #endif |
| 54 | |
| 55 | #ifdef CONFIG_KPROBES |
| 56 | static inline int notify_page_fault(struct pt_regs *regs, long err) |
| 57 | { |
| 58 | int ret = 0; |
| 59 | |
| 60 | /* kprobe_running() needs smp_processor_id() */ |
| 61 | if (!user_mode(regs)) { |
| 62 | preempt_disable(); |
| 63 | if (kprobe_running() && kprobe_fault_handler(regs, 14)) |
| 64 | ret = 1; |
| 65 | preempt_enable(); |
| 66 | } |
| 67 | |
| 68 | return ret; |
| 69 | } |
| 70 | #else |
| 71 | static inline int notify_page_fault(struct pt_regs *regs, long err) |
| 72 | { |
| 73 | return 0; |
| 74 | } |
| 75 | #endif |
| 76 | |
| 77 | |
| 78 | /* |
| 79 | * Unlock any spinlocks which will prevent us from getting the |
| 80 | * message out. |
| 81 | */ |
| 82 | void bust_spinlocks(int yes) |
| 83 | { |
| 84 | if (yes) { |
| 85 | oops_in_progress = 1; |
| 86 | } else { |
| 87 | int loglevel_save = console_loglevel; |
| 88 | console_unblank(); |
| 89 | oops_in_progress = 0; |
| 90 | /* |
| 91 | * OK, the message is on the console. Now we call printk() |
| 92 | * without oops_in_progress set so that printk will give klogd |
| 93 | * a poke. Hold onto your hats... |
| 94 | */ |
| 95 | console_loglevel = 15; |
| 96 | printk(" "); |
| 97 | console_loglevel = loglevel_save; |
| 98 | } |
| 99 | } |
| 100 | |
| 101 | /* |
| 102 | * Returns the address space associated with the fault. |
| 103 | * Returns 0 for kernel space, 1 for user space and |
| 104 | * 2 for code execution in user space with noexec=on. |
| 105 | */ |
| 106 | static inline int check_space(struct task_struct *tsk) |
| 107 | { |
| 108 | /* |
| 109 | * The lowest two bits of S390_lowcore.trans_exc_code |
| 110 | * indicate which paging table was used. |
| 111 | */ |
| 112 | int desc = S390_lowcore.trans_exc_code & 3; |
| 113 | |
| 114 | if (desc == 3) /* Home Segment Table Descriptor */ |
| 115 | return switch_amode == 0; |
| 116 | if (desc == 2) /* Secondary Segment Table Descriptor */ |
| 117 | return tsk->thread.mm_segment.ar4; |
| 118 | #ifdef CONFIG_S390_SWITCH_AMODE |
| 119 | if (unlikely(desc == 1)) { /* STD determined via access register */ |
| 120 | /* %a0 always indicates primary space. */ |
| 121 | if (S390_lowcore.exc_access_id != 0) { |
| 122 | save_access_regs(tsk->thread.acrs); |
| 123 | /* |
| 124 | * An alet of 0 indicates primary space. |
| 125 | * An alet of 1 indicates secondary space. |
| 126 | * Any other alet values generate an |
| 127 | * alen-translation exception. |
| 128 | */ |
| 129 | if (tsk->thread.acrs[S390_lowcore.exc_access_id]) |
| 130 | return tsk->thread.mm_segment.ar4; |
| 131 | } |
| 132 | } |
| 133 | #endif |
| 134 | /* Primary Segment Table Descriptor */ |
| 135 | return switch_amode << s390_noexec; |
| 136 | } |
| 137 | |
| 138 | /* |
| 139 | * Send SIGSEGV to task. This is an external routine |
| 140 | * to keep the stack usage of do_page_fault small. |
| 141 | */ |
| 142 | static void do_sigsegv(struct pt_regs *regs, unsigned long error_code, |
| 143 | int si_code, unsigned long address) |
| 144 | { |
| 145 | struct siginfo si; |
| 146 | |
| 147 | #if defined(CONFIG_SYSCTL) || defined(CONFIG_PROCESS_DEBUG) |
| 148 | #if defined(CONFIG_SYSCTL) |
| 149 | if (sysctl_userprocess_debug) |
| 150 | #endif |
| 151 | { |
| 152 | printk("User process fault: interruption code 0x%lX\n", |
| 153 | error_code); |
| 154 | printk("failing address: %lX\n", address); |
| 155 | show_regs(regs); |
| 156 | } |
| 157 | #endif |
| 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 void do_no_context(struct pt_regs *regs, unsigned long error_code, |
| 165 | unsigned long address) |
| 166 | { |
| 167 | const struct exception_table_entry *fixup; |
| 168 | |
| 169 | /* Are we prepared to handle this kernel fault? */ |
| 170 | fixup = search_exception_tables(regs->psw.addr & __FIXUP_MASK); |
| 171 | if (fixup) { |
| 172 | regs->psw.addr = fixup->fixup | PSW_ADDR_AMODE; |
| 173 | return; |
| 174 | } |
| 175 | |
| 176 | /* |
| 177 | * Oops. The kernel tried to access some bad page. We'll have to |
| 178 | * terminate things with extreme prejudice. |
| 179 | */ |
| 180 | if (check_space(current) == 0) |
| 181 | printk(KERN_ALERT "Unable to handle kernel pointer dereference" |
| 182 | " at virtual kernel address %p\n", (void *)address); |
| 183 | else |
| 184 | printk(KERN_ALERT "Unable to handle kernel paging request" |
| 185 | " at virtual user address %p\n", (void *)address); |
| 186 | |
| 187 | die("Oops", regs, error_code); |
| 188 | do_exit(SIGKILL); |
| 189 | } |
| 190 | |
| 191 | static void do_low_address(struct pt_regs *regs, unsigned long error_code) |
| 192 | { |
| 193 | /* Low-address protection hit in kernel mode means |
| 194 | NULL pointer write access in kernel mode. */ |
| 195 | if (regs->psw.mask & PSW_MASK_PSTATE) { |
| 196 | /* Low-address protection hit in user mode 'cannot happen'. */ |
| 197 | die ("Low-address protection", regs, error_code); |
| 198 | do_exit(SIGKILL); |
| 199 | } |
| 200 | |
| 201 | do_no_context(regs, error_code, 0); |
| 202 | } |
| 203 | |
| 204 | static void do_sigbus(struct pt_regs *regs, unsigned long error_code, |
| 205 | unsigned long address) |
| 206 | { |
| 207 | struct task_struct *tsk = current; |
| 208 | struct mm_struct *mm = tsk->mm; |
| 209 | |
| 210 | up_read(&mm->mmap_sem); |
| 211 | /* |
| 212 | * Send a sigbus, regardless of whether we were in kernel |
| 213 | * or user mode. |
| 214 | */ |
| 215 | tsk->thread.prot_addr = address; |
| 216 | tsk->thread.trap_no = error_code; |
| 217 | force_sig(SIGBUS, tsk); |
| 218 | |
| 219 | /* Kernel mode? Handle exceptions or die */ |
| 220 | if (!(regs->psw.mask & PSW_MASK_PSTATE)) |
| 221 | do_no_context(regs, error_code, address); |
| 222 | } |
| 223 | |
| 224 | #ifdef CONFIG_S390_EXEC_PROTECT |
| 225 | static int signal_return(struct mm_struct *mm, struct pt_regs *regs, |
| 226 | unsigned long address, unsigned long error_code) |
| 227 | { |
| 228 | u16 instruction; |
| 229 | int rc; |
| 230 | #ifdef CONFIG_COMPAT |
| 231 | int compat; |
| 232 | #endif |
| 233 | |
| 234 | pagefault_disable(); |
| 235 | rc = __get_user(instruction, (u16 __user *) regs->psw.addr); |
| 236 | pagefault_enable(); |
| 237 | if (rc) |
| 238 | return -EFAULT; |
| 239 | |
| 240 | up_read(&mm->mmap_sem); |
| 241 | clear_tsk_thread_flag(current, TIF_SINGLE_STEP); |
| 242 | #ifdef CONFIG_COMPAT |
| 243 | compat = is_compat_task(); |
| 244 | if (compat && instruction == 0x0a77) |
| 245 | sys32_sigreturn(); |
| 246 | else if (compat && instruction == 0x0aad) |
| 247 | sys32_rt_sigreturn(); |
| 248 | else |
| 249 | #endif |
| 250 | if (instruction == 0x0a77) |
| 251 | sys_sigreturn(); |
| 252 | else if (instruction == 0x0aad) |
| 253 | sys_rt_sigreturn(); |
| 254 | else { |
| 255 | current->thread.prot_addr = address; |
| 256 | current->thread.trap_no = error_code; |
| 257 | do_sigsegv(regs, error_code, SEGV_MAPERR, address); |
| 258 | } |
| 259 | return 0; |
| 260 | } |
| 261 | #endif /* CONFIG_S390_EXEC_PROTECT */ |
| 262 | |
| 263 | /* |
| 264 | * This routine handles page faults. It determines the address, |
| 265 | * and the problem, and then passes it off to one of the appropriate |
| 266 | * routines. |
| 267 | * |
| 268 | * error_code: |
| 269 | * 04 Protection -> Write-Protection (suprression) |
| 270 | * 10 Segment translation -> Not present (nullification) |
| 271 | * 11 Page translation -> Not present (nullification) |
| 272 | * 3b Region third trans. -> Not present (nullification) |
| 273 | */ |
| 274 | static inline void |
| 275 | do_exception(struct pt_regs *regs, unsigned long error_code, int write) |
| 276 | { |
| 277 | struct task_struct *tsk; |
| 278 | struct mm_struct *mm; |
| 279 | struct vm_area_struct *vma; |
| 280 | unsigned long address; |
| 281 | int space; |
| 282 | int si_code; |
| 283 | int fault; |
| 284 | |
| 285 | if (notify_page_fault(regs, error_code)) |
| 286 | return; |
| 287 | |
| 288 | tsk = current; |
| 289 | mm = tsk->mm; |
| 290 | |
| 291 | /* get the failing address and the affected space */ |
| 292 | address = S390_lowcore.trans_exc_code & __FAIL_ADDR_MASK; |
| 293 | space = check_space(tsk); |
| 294 | |
| 295 | /* |
| 296 | * Verify that the fault happened in user space, that |
| 297 | * we are not in an interrupt and that there is a |
| 298 | * user context. |
| 299 | */ |
| 300 | if (unlikely(space == 0 || in_atomic() || !mm)) |
| 301 | goto no_context; |
| 302 | |
| 303 | /* |
| 304 | * When we get here, the fault happened in the current |
| 305 | * task's user address space, so we can switch on the |
| 306 | * interrupts again and then search the VMAs |
| 307 | */ |
| 308 | local_irq_enable(); |
| 309 | perf_swcounter_event(PERF_COUNT_SW_PAGE_FAULTS, 1, 0, regs, address); |
| 310 | down_read(&mm->mmap_sem); |
| 311 | |
| 312 | si_code = SEGV_MAPERR; |
| 313 | vma = find_vma(mm, address); |
| 314 | if (!vma) |
| 315 | goto bad_area; |
| 316 | |
| 317 | #ifdef CONFIG_S390_EXEC_PROTECT |
| 318 | if (unlikely((space == 2) && !(vma->vm_flags & VM_EXEC))) |
| 319 | if (!signal_return(mm, regs, address, error_code)) |
| 320 | /* |
| 321 | * signal_return() has done an up_read(&mm->mmap_sem) |
| 322 | * if it returns 0. |
| 323 | */ |
| 324 | return; |
| 325 | #endif |
| 326 | |
| 327 | if (vma->vm_start <= address) |
| 328 | goto good_area; |
| 329 | if (!(vma->vm_flags & VM_GROWSDOWN)) |
| 330 | goto bad_area; |
| 331 | if (expand_stack(vma, address)) |
| 332 | goto bad_area; |
| 333 | /* |
| 334 | * Ok, we have a good vm_area for this memory access, so |
| 335 | * we can handle it.. |
| 336 | */ |
| 337 | good_area: |
| 338 | si_code = SEGV_ACCERR; |
| 339 | if (!write) { |
| 340 | /* page not present, check vm flags */ |
| 341 | if (!(vma->vm_flags & (VM_READ | VM_EXEC | VM_WRITE))) |
| 342 | goto bad_area; |
| 343 | } else { |
| 344 | if (!(vma->vm_flags & VM_WRITE)) |
| 345 | goto bad_area; |
| 346 | } |
| 347 | |
| 348 | if (is_vm_hugetlb_page(vma)) |
| 349 | address &= HPAGE_MASK; |
| 350 | /* |
| 351 | * If for any reason at all we couldn't handle the fault, |
| 352 | * make sure we exit gracefully rather than endlessly redo |
| 353 | * the fault. |
| 354 | */ |
| 355 | fault = handle_mm_fault(mm, vma, address, write ? FAULT_FLAG_WRITE : 0); |
| 356 | if (unlikely(fault & VM_FAULT_ERROR)) { |
| 357 | if (fault & VM_FAULT_OOM) { |
| 358 | up_read(&mm->mmap_sem); |
| 359 | pagefault_out_of_memory(); |
| 360 | return; |
| 361 | } else if (fault & VM_FAULT_SIGBUS) { |
| 362 | do_sigbus(regs, error_code, address); |
| 363 | return; |
| 364 | } |
| 365 | BUG(); |
| 366 | } |
| 367 | if (fault & VM_FAULT_MAJOR) { |
| 368 | tsk->maj_flt++; |
| 369 | perf_swcounter_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1, 0, |
| 370 | regs, address); |
| 371 | } else { |
| 372 | tsk->min_flt++; |
| 373 | perf_swcounter_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, 1, 0, |
| 374 | regs, address); |
| 375 | } |
| 376 | up_read(&mm->mmap_sem); |
| 377 | /* |
| 378 | * The instruction that caused the program check will |
| 379 | * be repeated. Don't signal single step via SIGTRAP. |
| 380 | */ |
| 381 | clear_tsk_thread_flag(tsk, TIF_SINGLE_STEP); |
| 382 | return; |
| 383 | |
| 384 | /* |
| 385 | * Something tried to access memory that isn't in our memory map.. |
| 386 | * Fix it, but check if it's kernel or user first.. |
| 387 | */ |
| 388 | bad_area: |
| 389 | up_read(&mm->mmap_sem); |
| 390 | |
| 391 | /* User mode accesses just cause a SIGSEGV */ |
| 392 | if (regs->psw.mask & PSW_MASK_PSTATE) { |
| 393 | tsk->thread.prot_addr = address; |
| 394 | tsk->thread.trap_no = error_code; |
| 395 | do_sigsegv(regs, error_code, si_code, address); |
| 396 | return; |
| 397 | } |
| 398 | |
| 399 | no_context: |
| 400 | do_no_context(regs, error_code, address); |
| 401 | } |
| 402 | |
| 403 | void __kprobes do_protection_exception(struct pt_regs *regs, |
| 404 | long error_code) |
| 405 | { |
| 406 | /* Protection exception is supressing, decrement psw address. */ |
| 407 | regs->psw.addr -= (error_code >> 16); |
| 408 | /* |
| 409 | * Check for low-address protection. This needs to be treated |
| 410 | * as a special case because the translation exception code |
| 411 | * field is not guaranteed to contain valid data in this case. |
| 412 | */ |
| 413 | if (unlikely(!(S390_lowcore.trans_exc_code & 4))) { |
| 414 | do_low_address(regs, error_code); |
| 415 | return; |
| 416 | } |
| 417 | do_exception(regs, 4, 1); |
| 418 | } |
| 419 | |
| 420 | void __kprobes do_dat_exception(struct pt_regs *regs, long error_code) |
| 421 | { |
| 422 | do_exception(regs, error_code & 0xff, 0); |
| 423 | } |
| 424 | |
| 425 | #ifdef CONFIG_64BIT |
| 426 | void __kprobes do_asce_exception(struct pt_regs *regs, unsigned long error_code) |
| 427 | { |
| 428 | struct mm_struct *mm; |
| 429 | struct vm_area_struct *vma; |
| 430 | unsigned long address; |
| 431 | int space; |
| 432 | |
| 433 | mm = current->mm; |
| 434 | address = S390_lowcore.trans_exc_code & __FAIL_ADDR_MASK; |
| 435 | space = check_space(current); |
| 436 | |
| 437 | if (unlikely(space == 0 || in_atomic() || !mm)) |
| 438 | goto no_context; |
| 439 | |
| 440 | local_irq_enable(); |
| 441 | |
| 442 | down_read(&mm->mmap_sem); |
| 443 | vma = find_vma(mm, address); |
| 444 | up_read(&mm->mmap_sem); |
| 445 | |
| 446 | if (vma) { |
| 447 | update_mm(mm, current); |
| 448 | return; |
| 449 | } |
| 450 | |
| 451 | /* User mode accesses just cause a SIGSEGV */ |
| 452 | if (regs->psw.mask & PSW_MASK_PSTATE) { |
| 453 | current->thread.prot_addr = address; |
| 454 | current->thread.trap_no = error_code; |
| 455 | do_sigsegv(regs, error_code, SEGV_MAPERR, address); |
| 456 | return; |
| 457 | } |
| 458 | |
| 459 | no_context: |
| 460 | do_no_context(regs, error_code, address); |
| 461 | } |
| 462 | #endif |
| 463 | |
| 464 | #ifdef CONFIG_PFAULT |
| 465 | /* |
| 466 | * 'pfault' pseudo page faults routines. |
| 467 | */ |
| 468 | static ext_int_info_t ext_int_pfault; |
| 469 | static int pfault_disable = 0; |
| 470 | |
| 471 | static int __init nopfault(char *str) |
| 472 | { |
| 473 | pfault_disable = 1; |
| 474 | return 1; |
| 475 | } |
| 476 | |
| 477 | __setup("nopfault", nopfault); |
| 478 | |
| 479 | typedef struct { |
| 480 | __u16 refdiagc; |
| 481 | __u16 reffcode; |
| 482 | __u16 refdwlen; |
| 483 | __u16 refversn; |
| 484 | __u64 refgaddr; |
| 485 | __u64 refselmk; |
| 486 | __u64 refcmpmk; |
| 487 | __u64 reserved; |
| 488 | } __attribute__ ((packed, aligned(8))) pfault_refbk_t; |
| 489 | |
| 490 | int pfault_init(void) |
| 491 | { |
| 492 | pfault_refbk_t refbk = |
| 493 | { 0x258, 0, 5, 2, __LC_CURRENT, 1ULL << 48, 1ULL << 48, |
| 494 | __PF_RES_FIELD }; |
| 495 | int rc; |
| 496 | |
| 497 | if (!MACHINE_IS_VM || pfault_disable) |
| 498 | return -1; |
| 499 | asm volatile( |
| 500 | " diag %1,%0,0x258\n" |
| 501 | "0: j 2f\n" |
| 502 | "1: la %0,8\n" |
| 503 | "2:\n" |
| 504 | EX_TABLE(0b,1b) |
| 505 | : "=d" (rc) : "a" (&refbk), "m" (refbk) : "cc"); |
| 506 | __ctl_set_bit(0, 9); |
| 507 | return rc; |
| 508 | } |
| 509 | |
| 510 | void pfault_fini(void) |
| 511 | { |
| 512 | pfault_refbk_t refbk = |
| 513 | { 0x258, 1, 5, 2, 0ULL, 0ULL, 0ULL, 0ULL }; |
| 514 | |
| 515 | if (!MACHINE_IS_VM || pfault_disable) |
| 516 | return; |
| 517 | __ctl_clear_bit(0,9); |
| 518 | asm volatile( |
| 519 | " diag %0,0,0x258\n" |
| 520 | "0:\n" |
| 521 | EX_TABLE(0b,0b) |
| 522 | : : "a" (&refbk), "m" (refbk) : "cc"); |
| 523 | } |
| 524 | |
| 525 | static void pfault_interrupt(__u16 error_code) |
| 526 | { |
| 527 | struct task_struct *tsk; |
| 528 | __u16 subcode; |
| 529 | |
| 530 | /* |
| 531 | * Get the external interruption subcode & pfault |
| 532 | * initial/completion signal bit. VM stores this |
| 533 | * in the 'cpu address' field associated with the |
| 534 | * external interrupt. |
| 535 | */ |
| 536 | subcode = S390_lowcore.cpu_addr; |
| 537 | if ((subcode & 0xff00) != __SUBCODE_MASK) |
| 538 | return; |
| 539 | |
| 540 | /* |
| 541 | * Get the token (= address of the task structure of the affected task). |
| 542 | */ |
| 543 | tsk = *(struct task_struct **) __LC_PFAULT_INTPARM; |
| 544 | |
| 545 | if (subcode & 0x0080) { |
| 546 | /* signal bit is set -> a page has been swapped in by VM */ |
| 547 | if (xchg(&tsk->thread.pfault_wait, -1) != 0) { |
| 548 | /* Initial interrupt was faster than the completion |
| 549 | * interrupt. pfault_wait is valid. Set pfault_wait |
| 550 | * back to zero and wake up the process. This can |
| 551 | * safely be done because the task is still sleeping |
| 552 | * and can't produce new pfaults. */ |
| 553 | tsk->thread.pfault_wait = 0; |
| 554 | wake_up_process(tsk); |
| 555 | put_task_struct(tsk); |
| 556 | } |
| 557 | } else { |
| 558 | /* signal bit not set -> a real page is missing. */ |
| 559 | get_task_struct(tsk); |
| 560 | set_task_state(tsk, TASK_UNINTERRUPTIBLE); |
| 561 | if (xchg(&tsk->thread.pfault_wait, 1) != 0) { |
| 562 | /* Completion interrupt was faster than the initial |
| 563 | * interrupt (swapped in a -1 for pfault_wait). Set |
| 564 | * pfault_wait back to zero and exit. This can be |
| 565 | * done safely because tsk is running in kernel |
| 566 | * mode and can't produce new pfaults. */ |
| 567 | tsk->thread.pfault_wait = 0; |
| 568 | set_task_state(tsk, TASK_RUNNING); |
| 569 | put_task_struct(tsk); |
| 570 | } else |
| 571 | set_tsk_need_resched(tsk); |
| 572 | } |
| 573 | } |
| 574 | |
| 575 | void __init pfault_irq_init(void) |
| 576 | { |
| 577 | if (!MACHINE_IS_VM) |
| 578 | return; |
| 579 | |
| 580 | /* |
| 581 | * Try to get pfault pseudo page faults going. |
| 582 | */ |
| 583 | if (register_early_external_interrupt(0x2603, pfault_interrupt, |
| 584 | &ext_int_pfault) != 0) |
| 585 | panic("Couldn't request external interrupt 0x2603"); |
| 586 | |
| 587 | if (pfault_init() == 0) |
| 588 | return; |
| 589 | |
| 590 | /* Tough luck, no pfault. */ |
| 591 | pfault_disable = 1; |
| 592 | unregister_early_external_interrupt(0x2603, pfault_interrupt, |
| 593 | &ext_int_pfault); |
| 594 | } |
| 595 | #endif |