1 /* 2 * Based on arch/arm/mm/fault.c 3 * 4 * Copyright (C) 1995 Linus Torvalds 5 * Copyright (C) 1995-2004 Russell King 6 * Copyright (C) 2012 ARM Ltd. 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License version 2 as 10 * published by the Free Software Foundation. 11 * 12 * This program is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 * GNU General Public License for more details. 16 * 17 * You should have received a copy of the GNU General Public License 18 * along with this program. If not, see <http://www.gnu.org/licenses/>. 19 */ 20 21 #include <linux/module.h> 22 #include <linux/signal.h> 23 #include <linux/mm.h> 24 #include <linux/hardirq.h> 25 #include <linux/init.h> 26 #include <linux/kprobes.h> 27 #include <linux/uaccess.h> 28 #include <linux/page-flags.h> 29 #include <linux/sched.h> 30 #include <linux/highmem.h> 31 #include <linux/perf_event.h> 32 33 #include <asm/cpufeature.h> 34 #include <asm/exception.h> 35 #include <asm/debug-monitors.h> 36 #include <asm/esr.h> 37 #include <asm/sysreg.h> 38 #include <asm/system_misc.h> 39 #include <asm/pgtable.h> 40 #include <asm/tlbflush.h> 41 42 static const char *fault_name(unsigned int esr); 43 44 /* 45 * Dump out the page tables associated with 'addr' in mm 'mm'. 46 */ 47 void show_pte(struct mm_struct *mm, unsigned long addr) 48 { 49 pgd_t *pgd; 50 51 if (!mm) 52 mm = &init_mm; 53 54 pr_alert("pgd = %p\n", mm->pgd); 55 pgd = pgd_offset(mm, addr); 56 pr_alert("[%08lx] *pgd=%016llx", addr, pgd_val(*pgd)); 57 58 do { 59 pud_t *pud; 60 pmd_t *pmd; 61 pte_t *pte; 62 63 if (pgd_none(*pgd) || pgd_bad(*pgd)) 64 break; 65 66 pud = pud_offset(pgd, addr); 67 printk(", *pud=%016llx", pud_val(*pud)); 68 if (pud_none(*pud) || pud_bad(*pud)) 69 break; 70 71 pmd = pmd_offset(pud, addr); 72 printk(", *pmd=%016llx", pmd_val(*pmd)); 73 if (pmd_none(*pmd) || pmd_bad(*pmd)) 74 break; 75 76 pte = pte_offset_map(pmd, addr); 77 printk(", *pte=%016llx", pte_val(*pte)); 78 pte_unmap(pte); 79 } while(0); 80 81 printk("\n"); 82 } 83 84 #ifdef CONFIG_ARM64_HW_AFDBM 85 /* 86 * This function sets the access flags (dirty, accessed), as well as write 87 * permission, and only to a more permissive setting. 88 * 89 * It needs to cope with hardware update of the accessed/dirty state by other 90 * agents in the system and can safely skip the __sync_icache_dcache() call as, 91 * like set_pte_at(), the PTE is never changed from no-exec to exec here. 92 * 93 * Returns whether or not the PTE actually changed. 94 */ 95 int ptep_set_access_flags(struct vm_area_struct *vma, 96 unsigned long address, pte_t *ptep, 97 pte_t entry, int dirty) 98 { 99 pteval_t old_pteval; 100 unsigned int tmp; 101 102 if (pte_same(*ptep, entry)) 103 return 0; 104 105 /* only preserve the access flags and write permission */ 106 pte_val(entry) &= PTE_AF | PTE_WRITE | PTE_DIRTY; 107 108 /* 109 * PTE_RDONLY is cleared by default in the asm below, so set it in 110 * back if necessary (read-only or clean PTE). 111 */ 112 if (!pte_write(entry) || !pte_sw_dirty(entry)) 113 pte_val(entry) |= PTE_RDONLY; 114 115 /* 116 * Setting the flags must be done atomically to avoid racing with the 117 * hardware update of the access/dirty state. 118 */ 119 asm volatile("// ptep_set_access_flags\n" 120 " prfm pstl1strm, %2\n" 121 "1: ldxr %0, %2\n" 122 " and %0, %0, %3 // clear PTE_RDONLY\n" 123 " orr %0, %0, %4 // set flags\n" 124 " stxr %w1, %0, %2\n" 125 " cbnz %w1, 1b\n" 126 : "=&r" (old_pteval), "=&r" (tmp), "+Q" (pte_val(*ptep)) 127 : "L" (~PTE_RDONLY), "r" (pte_val(entry))); 128 129 flush_tlb_fix_spurious_fault(vma, address); 130 return 1; 131 } 132 #endif 133 134 /* 135 * The kernel tried to access some page that wasn't present. 136 */ 137 static void __do_kernel_fault(struct mm_struct *mm, unsigned long addr, 138 unsigned int esr, struct pt_regs *regs) 139 { 140 /* 141 * Are we prepared to handle this kernel fault? 142 */ 143 if (fixup_exception(regs)) 144 return; 145 146 /* 147 * No handler, we'll have to terminate things with extreme prejudice. 148 */ 149 bust_spinlocks(1); 150 pr_alert("Unable to handle kernel %s at virtual address %08lx\n", 151 (addr < PAGE_SIZE) ? "NULL pointer dereference" : 152 "paging request", addr); 153 154 show_pte(mm, addr); 155 die("Oops", regs, esr); 156 bust_spinlocks(0); 157 do_exit(SIGKILL); 158 } 159 160 /* 161 * Something tried to access memory that isn't in our memory map. User mode 162 * accesses just cause a SIGSEGV 163 */ 164 static void __do_user_fault(struct task_struct *tsk, unsigned long addr, 165 unsigned int esr, unsigned int sig, int code, 166 struct pt_regs *regs) 167 { 168 struct siginfo si; 169 170 if (unhandled_signal(tsk, sig) && show_unhandled_signals_ratelimited()) { 171 pr_info("%s[%d]: unhandled %s (%d) at 0x%08lx, esr 0x%03x\n", 172 tsk->comm, task_pid_nr(tsk), fault_name(esr), sig, 173 addr, esr); 174 show_pte(tsk->mm, addr); 175 show_regs(regs); 176 } 177 178 tsk->thread.fault_address = addr; 179 tsk->thread.fault_code = esr; 180 si.si_signo = sig; 181 si.si_errno = 0; 182 si.si_code = code; 183 si.si_addr = (void __user *)addr; 184 force_sig_info(sig, &si, tsk); 185 } 186 187 static void do_bad_area(unsigned long addr, unsigned int esr, struct pt_regs *regs) 188 { 189 struct task_struct *tsk = current; 190 struct mm_struct *mm = tsk->active_mm; 191 192 /* 193 * If we are in kernel mode at this point, we have no context to 194 * handle this fault with. 195 */ 196 if (user_mode(regs)) 197 __do_user_fault(tsk, addr, esr, SIGSEGV, SEGV_MAPERR, regs); 198 else 199 __do_kernel_fault(mm, addr, esr, regs); 200 } 201 202 #define VM_FAULT_BADMAP 0x010000 203 #define VM_FAULT_BADACCESS 0x020000 204 205 #define ESR_LNX_EXEC (1 << 24) 206 207 static int __do_page_fault(struct mm_struct *mm, unsigned long addr, 208 unsigned int mm_flags, unsigned long vm_flags, 209 struct task_struct *tsk) 210 { 211 struct vm_area_struct *vma; 212 int fault; 213 214 vma = find_vma(mm, addr); 215 fault = VM_FAULT_BADMAP; 216 if (unlikely(!vma)) 217 goto out; 218 if (unlikely(vma->vm_start > addr)) 219 goto check_stack; 220 221 /* 222 * Ok, we have a good vm_area for this memory access, so we can handle 223 * it. 224 */ 225 good_area: 226 /* 227 * Check that the permissions on the VMA allow for the fault which 228 * occurred. If we encountered a write or exec fault, we must have 229 * appropriate permissions, otherwise we allow any permission. 230 */ 231 if (!(vma->vm_flags & vm_flags)) { 232 fault = VM_FAULT_BADACCESS; 233 goto out; 234 } 235 236 return handle_mm_fault(mm, vma, addr & PAGE_MASK, mm_flags); 237 238 check_stack: 239 if (vma->vm_flags & VM_GROWSDOWN && !expand_stack(vma, addr)) 240 goto good_area; 241 out: 242 return fault; 243 } 244 245 static inline int permission_fault(unsigned int esr) 246 { 247 unsigned int ec = (esr & ESR_ELx_EC_MASK) >> ESR_ELx_EC_SHIFT; 248 unsigned int fsc_type = esr & ESR_ELx_FSC_TYPE; 249 250 return (ec == ESR_ELx_EC_DABT_CUR && fsc_type == ESR_ELx_FSC_PERM); 251 } 252 253 static int __kprobes do_page_fault(unsigned long addr, unsigned int esr, 254 struct pt_regs *regs) 255 { 256 struct task_struct *tsk; 257 struct mm_struct *mm; 258 int fault, sig, code; 259 unsigned long vm_flags = VM_READ | VM_WRITE | VM_EXEC; 260 unsigned int mm_flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE; 261 262 tsk = current; 263 mm = tsk->mm; 264 265 /* 266 * If we're in an interrupt or have no user context, we must not take 267 * the fault. 268 */ 269 if (faulthandler_disabled() || !mm) 270 goto no_context; 271 272 if (user_mode(regs)) 273 mm_flags |= FAULT_FLAG_USER; 274 275 if (esr & ESR_LNX_EXEC) { 276 vm_flags = VM_EXEC; 277 } else if ((esr & ESR_ELx_WNR) && !(esr & ESR_ELx_CM)) { 278 vm_flags = VM_WRITE; 279 mm_flags |= FAULT_FLAG_WRITE; 280 } 281 282 if (permission_fault(esr) && (addr < USER_DS)) { 283 if (get_fs() == KERNEL_DS) 284 die("Accessing user space memory with fs=KERNEL_DS", regs, esr); 285 286 if (!search_exception_tables(regs->pc)) 287 die("Accessing user space memory outside uaccess.h routines", regs, esr); 288 } 289 290 /* 291 * As per x86, we may deadlock here. However, since the kernel only 292 * validly references user space from well defined areas of the code, 293 * we can bug out early if this is from code which shouldn't. 294 */ 295 if (!down_read_trylock(&mm->mmap_sem)) { 296 if (!user_mode(regs) && !search_exception_tables(regs->pc)) 297 goto no_context; 298 retry: 299 down_read(&mm->mmap_sem); 300 } else { 301 /* 302 * The above down_read_trylock() might have succeeded in which 303 * case, we'll have missed the might_sleep() from down_read(). 304 */ 305 might_sleep(); 306 #ifdef CONFIG_DEBUG_VM 307 if (!user_mode(regs) && !search_exception_tables(regs->pc)) 308 goto no_context; 309 #endif 310 } 311 312 fault = __do_page_fault(mm, addr, mm_flags, vm_flags, tsk); 313 314 /* 315 * If we need to retry but a fatal signal is pending, handle the 316 * signal first. We do not need to release the mmap_sem because it 317 * would already be released in __lock_page_or_retry in mm/filemap.c. 318 */ 319 if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current)) 320 return 0; 321 322 /* 323 * Major/minor page fault accounting is only done on the initial 324 * attempt. If we go through a retry, it is extremely likely that the 325 * page will be found in page cache at that point. 326 */ 327 328 perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, addr); 329 if (mm_flags & FAULT_FLAG_ALLOW_RETRY) { 330 if (fault & VM_FAULT_MAJOR) { 331 tsk->maj_flt++; 332 perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1, regs, 333 addr); 334 } else { 335 tsk->min_flt++; 336 perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, 1, regs, 337 addr); 338 } 339 if (fault & VM_FAULT_RETRY) { 340 /* 341 * Clear FAULT_FLAG_ALLOW_RETRY to avoid any risk of 342 * starvation. 343 */ 344 mm_flags &= ~FAULT_FLAG_ALLOW_RETRY; 345 mm_flags |= FAULT_FLAG_TRIED; 346 goto retry; 347 } 348 } 349 350 up_read(&mm->mmap_sem); 351 352 /* 353 * Handle the "normal" case first - VM_FAULT_MAJOR 354 */ 355 if (likely(!(fault & (VM_FAULT_ERROR | VM_FAULT_BADMAP | 356 VM_FAULT_BADACCESS)))) 357 return 0; 358 359 /* 360 * If we are in kernel mode at this point, we have no context to 361 * handle this fault with. 362 */ 363 if (!user_mode(regs)) 364 goto no_context; 365 366 if (fault & VM_FAULT_OOM) { 367 /* 368 * We ran out of memory, call the OOM killer, and return to 369 * userspace (which will retry the fault, or kill us if we got 370 * oom-killed). 371 */ 372 pagefault_out_of_memory(); 373 return 0; 374 } 375 376 if (fault & VM_FAULT_SIGBUS) { 377 /* 378 * We had some memory, but were unable to successfully fix up 379 * this page fault. 380 */ 381 sig = SIGBUS; 382 code = BUS_ADRERR; 383 } else { 384 /* 385 * Something tried to access memory that isn't in our memory 386 * map. 387 */ 388 sig = SIGSEGV; 389 code = fault == VM_FAULT_BADACCESS ? 390 SEGV_ACCERR : SEGV_MAPERR; 391 } 392 393 __do_user_fault(tsk, addr, esr, sig, code, regs); 394 return 0; 395 396 no_context: 397 __do_kernel_fault(mm, addr, esr, regs); 398 return 0; 399 } 400 401 /* 402 * First Level Translation Fault Handler 403 * 404 * We enter here because the first level page table doesn't contain a valid 405 * entry for the address. 406 * 407 * If the address is in kernel space (>= TASK_SIZE), then we are probably 408 * faulting in the vmalloc() area. 409 * 410 * If the init_task's first level page tables contains the relevant entry, we 411 * copy the it to this task. If not, we send the process a signal, fixup the 412 * exception, or oops the kernel. 413 * 414 * NOTE! We MUST NOT take any locks for this case. We may be in an interrupt 415 * or a critical region, and should only copy the information from the master 416 * page table, nothing more. 417 */ 418 static int __kprobes do_translation_fault(unsigned long addr, 419 unsigned int esr, 420 struct pt_regs *regs) 421 { 422 if (addr < TASK_SIZE) 423 return do_page_fault(addr, esr, regs); 424 425 do_bad_area(addr, esr, regs); 426 return 0; 427 } 428 429 static int do_alignment_fault(unsigned long addr, unsigned int esr, 430 struct pt_regs *regs) 431 { 432 do_bad_area(addr, esr, regs); 433 return 0; 434 } 435 436 /* 437 * This abort handler always returns "fault". 438 */ 439 static int do_bad(unsigned long addr, unsigned int esr, struct pt_regs *regs) 440 { 441 return 1; 442 } 443 444 static const struct fault_info { 445 int (*fn)(unsigned long addr, unsigned int esr, struct pt_regs *regs); 446 int sig; 447 int code; 448 const char *name; 449 } fault_info[] = { 450 { do_bad, SIGBUS, 0, "ttbr address size fault" }, 451 { do_bad, SIGBUS, 0, "level 1 address size fault" }, 452 { do_bad, SIGBUS, 0, "level 2 address size fault" }, 453 { do_bad, SIGBUS, 0, "level 3 address size fault" }, 454 { do_translation_fault, SIGSEGV, SEGV_MAPERR, "level 0 translation fault" }, 455 { do_translation_fault, SIGSEGV, SEGV_MAPERR, "level 1 translation fault" }, 456 { do_translation_fault, SIGSEGV, SEGV_MAPERR, "level 2 translation fault" }, 457 { do_page_fault, SIGSEGV, SEGV_MAPERR, "level 3 translation fault" }, 458 { do_bad, SIGBUS, 0, "unknown 8" }, 459 { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 1 access flag fault" }, 460 { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 2 access flag fault" }, 461 { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 3 access flag fault" }, 462 { do_bad, SIGBUS, 0, "unknown 12" }, 463 { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 1 permission fault" }, 464 { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 2 permission fault" }, 465 { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 3 permission fault" }, 466 { do_bad, SIGBUS, 0, "synchronous external abort" }, 467 { do_bad, SIGBUS, 0, "unknown 17" }, 468 { do_bad, SIGBUS, 0, "unknown 18" }, 469 { do_bad, SIGBUS, 0, "unknown 19" }, 470 { do_bad, SIGBUS, 0, "synchronous abort (translation table walk)" }, 471 { do_bad, SIGBUS, 0, "synchronous abort (translation table walk)" }, 472 { do_bad, SIGBUS, 0, "synchronous abort (translation table walk)" }, 473 { do_bad, SIGBUS, 0, "synchronous abort (translation table walk)" }, 474 { do_bad, SIGBUS, 0, "synchronous parity error" }, 475 { do_bad, SIGBUS, 0, "unknown 25" }, 476 { do_bad, SIGBUS, 0, "unknown 26" }, 477 { do_bad, SIGBUS, 0, "unknown 27" }, 478 { do_bad, SIGBUS, 0, "synchronous parity error (translation table walk)" }, 479 { do_bad, SIGBUS, 0, "synchronous parity error (translation table walk)" }, 480 { do_bad, SIGBUS, 0, "synchronous parity error (translation table walk)" }, 481 { do_bad, SIGBUS, 0, "synchronous parity error (translation table walk)" }, 482 { do_bad, SIGBUS, 0, "unknown 32" }, 483 { do_alignment_fault, SIGBUS, BUS_ADRALN, "alignment fault" }, 484 { do_bad, SIGBUS, 0, "unknown 34" }, 485 { do_bad, SIGBUS, 0, "unknown 35" }, 486 { do_bad, SIGBUS, 0, "unknown 36" }, 487 { do_bad, SIGBUS, 0, "unknown 37" }, 488 { do_bad, SIGBUS, 0, "unknown 38" }, 489 { do_bad, SIGBUS, 0, "unknown 39" }, 490 { do_bad, SIGBUS, 0, "unknown 40" }, 491 { do_bad, SIGBUS, 0, "unknown 41" }, 492 { do_bad, SIGBUS, 0, "unknown 42" }, 493 { do_bad, SIGBUS, 0, "unknown 43" }, 494 { do_bad, SIGBUS, 0, "unknown 44" }, 495 { do_bad, SIGBUS, 0, "unknown 45" }, 496 { do_bad, SIGBUS, 0, "unknown 46" }, 497 { do_bad, SIGBUS, 0, "unknown 47" }, 498 { do_bad, SIGBUS, 0, "TLB conflict abort" }, 499 { do_bad, SIGBUS, 0, "unknown 49" }, 500 { do_bad, SIGBUS, 0, "unknown 50" }, 501 { do_bad, SIGBUS, 0, "unknown 51" }, 502 { do_bad, SIGBUS, 0, "implementation fault (lockdown abort)" }, 503 { do_bad, SIGBUS, 0, "implementation fault (unsupported exclusive)" }, 504 { do_bad, SIGBUS, 0, "unknown 54" }, 505 { do_bad, SIGBUS, 0, "unknown 55" }, 506 { do_bad, SIGBUS, 0, "unknown 56" }, 507 { do_bad, SIGBUS, 0, "unknown 57" }, 508 { do_bad, SIGBUS, 0, "unknown 58" }, 509 { do_bad, SIGBUS, 0, "unknown 59" }, 510 { do_bad, SIGBUS, 0, "unknown 60" }, 511 { do_bad, SIGBUS, 0, "section domain fault" }, 512 { do_bad, SIGBUS, 0, "page domain fault" }, 513 { do_bad, SIGBUS, 0, "unknown 63" }, 514 }; 515 516 static const char *fault_name(unsigned int esr) 517 { 518 const struct fault_info *inf = fault_info + (esr & 63); 519 return inf->name; 520 } 521 522 /* 523 * Dispatch a data abort to the relevant handler. 524 */ 525 asmlinkage void __exception do_mem_abort(unsigned long addr, unsigned int esr, 526 struct pt_regs *regs) 527 { 528 const struct fault_info *inf = fault_info + (esr & 63); 529 struct siginfo info; 530 531 if (!inf->fn(addr, esr, regs)) 532 return; 533 534 pr_alert("Unhandled fault: %s (0x%08x) at 0x%016lx\n", 535 inf->name, esr, addr); 536 537 info.si_signo = inf->sig; 538 info.si_errno = 0; 539 info.si_code = inf->code; 540 info.si_addr = (void __user *)addr; 541 arm64_notify_die("", regs, &info, esr); 542 } 543 544 /* 545 * Handle stack alignment exceptions. 546 */ 547 asmlinkage void __exception do_sp_pc_abort(unsigned long addr, 548 unsigned int esr, 549 struct pt_regs *regs) 550 { 551 struct siginfo info; 552 struct task_struct *tsk = current; 553 554 if (show_unhandled_signals && unhandled_signal(tsk, SIGBUS)) 555 pr_info_ratelimited("%s[%d]: %s exception: pc=%p sp=%p\n", 556 tsk->comm, task_pid_nr(tsk), 557 esr_get_class_string(esr), (void *)regs->pc, 558 (void *)regs->sp); 559 560 info.si_signo = SIGBUS; 561 info.si_errno = 0; 562 info.si_code = BUS_ADRALN; 563 info.si_addr = (void __user *)addr; 564 arm64_notify_die("Oops - SP/PC alignment exception", regs, &info, esr); 565 } 566 567 int __init early_brk64(unsigned long addr, unsigned int esr, 568 struct pt_regs *regs); 569 570 /* 571 * __refdata because early_brk64 is __init, but the reference to it is 572 * clobbered at arch_initcall time. 573 * See traps.c and debug-monitors.c:debug_traps_init(). 574 */ 575 static struct fault_info __refdata debug_fault_info[] = { 576 { do_bad, SIGTRAP, TRAP_HWBKPT, "hardware breakpoint" }, 577 { do_bad, SIGTRAP, TRAP_HWBKPT, "hardware single-step" }, 578 { do_bad, SIGTRAP, TRAP_HWBKPT, "hardware watchpoint" }, 579 { do_bad, SIGBUS, 0, "unknown 3" }, 580 { do_bad, SIGTRAP, TRAP_BRKPT, "aarch32 BKPT" }, 581 { do_bad, SIGTRAP, 0, "aarch32 vector catch" }, 582 { early_brk64, SIGTRAP, TRAP_BRKPT, "aarch64 BRK" }, 583 { do_bad, SIGBUS, 0, "unknown 7" }, 584 }; 585 586 void __init hook_debug_fault_code(int nr, 587 int (*fn)(unsigned long, unsigned int, struct pt_regs *), 588 int sig, int code, const char *name) 589 { 590 BUG_ON(nr < 0 || nr >= ARRAY_SIZE(debug_fault_info)); 591 592 debug_fault_info[nr].fn = fn; 593 debug_fault_info[nr].sig = sig; 594 debug_fault_info[nr].code = code; 595 debug_fault_info[nr].name = name; 596 } 597 598 asmlinkage int __exception do_debug_exception(unsigned long addr, 599 unsigned int esr, 600 struct pt_regs *regs) 601 { 602 const struct fault_info *inf = debug_fault_info + DBG_ESR_EVT(esr); 603 struct siginfo info; 604 int rv; 605 606 /* 607 * Tell lockdep we disabled irqs in entry.S. Do nothing if they were 608 * already disabled to preserve the last enabled/disabled addresses. 609 */ 610 if (interrupts_enabled(regs)) 611 trace_hardirqs_off(); 612 613 if (!inf->fn(addr, esr, regs)) { 614 rv = 1; 615 } else { 616 pr_alert("Unhandled debug exception: %s (0x%08x) at 0x%016lx\n", 617 inf->name, esr, addr); 618 619 info.si_signo = inf->sig; 620 info.si_errno = 0; 621 info.si_code = inf->code; 622 info.si_addr = (void __user *)addr; 623 arm64_notify_die("", regs, &info, 0); 624 rv = 0; 625 } 626 627 if (interrupts_enabled(regs)) 628 trace_hardirqs_on(); 629 630 return rv; 631 } 632 633 #ifdef CONFIG_ARM64_PAN 634 void cpu_enable_pan(void *__unused) 635 { 636 config_sctlr_el1(SCTLR_EL1_SPAN, 0); 637 } 638 #endif /* CONFIG_ARM64_PAN */ 639 640 #ifdef CONFIG_ARM64_UAO 641 /* 642 * Kernel threads have fs=KERNEL_DS by default, and don't need to call 643 * set_fs(), devtmpfs in particular relies on this behaviour. 644 * We need to enable the feature at runtime (instead of adding it to 645 * PSR_MODE_EL1h) as the feature may not be implemented by the cpu. 646 */ 647 void cpu_enable_uao(void *__unused) 648 { 649 asm(SET_PSTATE_UAO(1)); 650 } 651 #endif /* CONFIG_ARM64_UAO */ 652