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 /* regs->orig_addr_limit may be 0 if we entered from EL0 */ 284 if (regs->orig_addr_limit == KERNEL_DS) 285 die("Accessing user space memory with fs=KERNEL_DS", regs, esr); 286 287 if (!search_exception_tables(regs->pc)) 288 die("Accessing user space memory outside uaccess.h routines", regs, esr); 289 } 290 291 /* 292 * As per x86, we may deadlock here. However, since the kernel only 293 * validly references user space from well defined areas of the code, 294 * we can bug out early if this is from code which shouldn't. 295 */ 296 if (!down_read_trylock(&mm->mmap_sem)) { 297 if (!user_mode(regs) && !search_exception_tables(regs->pc)) 298 goto no_context; 299 retry: 300 down_read(&mm->mmap_sem); 301 } else { 302 /* 303 * The above down_read_trylock() might have succeeded in which 304 * case, we'll have missed the might_sleep() from down_read(). 305 */ 306 might_sleep(); 307 #ifdef CONFIG_DEBUG_VM 308 if (!user_mode(regs) && !search_exception_tables(regs->pc)) 309 goto no_context; 310 #endif 311 } 312 313 fault = __do_page_fault(mm, addr, mm_flags, vm_flags, tsk); 314 315 /* 316 * If we need to retry but a fatal signal is pending, handle the 317 * signal first. We do not need to release the mmap_sem because it 318 * would already be released in __lock_page_or_retry in mm/filemap.c. 319 */ 320 if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current)) 321 return 0; 322 323 /* 324 * Major/minor page fault accounting is only done on the initial 325 * attempt. If we go through a retry, it is extremely likely that the 326 * page will be found in page cache at that point. 327 */ 328 329 perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, addr); 330 if (mm_flags & FAULT_FLAG_ALLOW_RETRY) { 331 if (fault & VM_FAULT_MAJOR) { 332 tsk->maj_flt++; 333 perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1, regs, 334 addr); 335 } else { 336 tsk->min_flt++; 337 perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, 1, regs, 338 addr); 339 } 340 if (fault & VM_FAULT_RETRY) { 341 /* 342 * Clear FAULT_FLAG_ALLOW_RETRY to avoid any risk of 343 * starvation. 344 */ 345 mm_flags &= ~FAULT_FLAG_ALLOW_RETRY; 346 mm_flags |= FAULT_FLAG_TRIED; 347 goto retry; 348 } 349 } 350 351 up_read(&mm->mmap_sem); 352 353 /* 354 * Handle the "normal" case first - VM_FAULT_MAJOR 355 */ 356 if (likely(!(fault & (VM_FAULT_ERROR | VM_FAULT_BADMAP | 357 VM_FAULT_BADACCESS)))) 358 return 0; 359 360 /* 361 * If we are in kernel mode at this point, we have no context to 362 * handle this fault with. 363 */ 364 if (!user_mode(regs)) 365 goto no_context; 366 367 if (fault & VM_FAULT_OOM) { 368 /* 369 * We ran out of memory, call the OOM killer, and return to 370 * userspace (which will retry the fault, or kill us if we got 371 * oom-killed). 372 */ 373 pagefault_out_of_memory(); 374 return 0; 375 } 376 377 if (fault & VM_FAULT_SIGBUS) { 378 /* 379 * We had some memory, but were unable to successfully fix up 380 * this page fault. 381 */ 382 sig = SIGBUS; 383 code = BUS_ADRERR; 384 } else { 385 /* 386 * Something tried to access memory that isn't in our memory 387 * map. 388 */ 389 sig = SIGSEGV; 390 code = fault == VM_FAULT_BADACCESS ? 391 SEGV_ACCERR : SEGV_MAPERR; 392 } 393 394 __do_user_fault(tsk, addr, esr, sig, code, regs); 395 return 0; 396 397 no_context: 398 __do_kernel_fault(mm, addr, esr, regs); 399 return 0; 400 } 401 402 /* 403 * First Level Translation Fault Handler 404 * 405 * We enter here because the first level page table doesn't contain a valid 406 * entry for the address. 407 * 408 * If the address is in kernel space (>= TASK_SIZE), then we are probably 409 * faulting in the vmalloc() area. 410 * 411 * If the init_task's first level page tables contains the relevant entry, we 412 * copy the it to this task. If not, we send the process a signal, fixup the 413 * exception, or oops the kernel. 414 * 415 * NOTE! We MUST NOT take any locks for this case. We may be in an interrupt 416 * or a critical region, and should only copy the information from the master 417 * page table, nothing more. 418 */ 419 static int __kprobes do_translation_fault(unsigned long addr, 420 unsigned int esr, 421 struct pt_regs *regs) 422 { 423 if (addr < TASK_SIZE) 424 return do_page_fault(addr, esr, regs); 425 426 do_bad_area(addr, esr, regs); 427 return 0; 428 } 429 430 static int do_alignment_fault(unsigned long addr, unsigned int esr, 431 struct pt_regs *regs) 432 { 433 do_bad_area(addr, esr, regs); 434 return 0; 435 } 436 437 /* 438 * This abort handler always returns "fault". 439 */ 440 static int do_bad(unsigned long addr, unsigned int esr, struct pt_regs *regs) 441 { 442 return 1; 443 } 444 445 static const struct fault_info { 446 int (*fn)(unsigned long addr, unsigned int esr, struct pt_regs *regs); 447 int sig; 448 int code; 449 const char *name; 450 } fault_info[] = { 451 { do_bad, SIGBUS, 0, "ttbr address size fault" }, 452 { do_bad, SIGBUS, 0, "level 1 address size fault" }, 453 { do_bad, SIGBUS, 0, "level 2 address size fault" }, 454 { do_bad, SIGBUS, 0, "level 3 address size fault" }, 455 { do_translation_fault, SIGSEGV, SEGV_MAPERR, "level 0 translation fault" }, 456 { do_translation_fault, SIGSEGV, SEGV_MAPERR, "level 1 translation fault" }, 457 { do_translation_fault, SIGSEGV, SEGV_MAPERR, "level 2 translation fault" }, 458 { do_page_fault, SIGSEGV, SEGV_MAPERR, "level 3 translation fault" }, 459 { do_bad, SIGBUS, 0, "unknown 8" }, 460 { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 1 access flag fault" }, 461 { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 2 access flag fault" }, 462 { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 3 access flag fault" }, 463 { do_bad, SIGBUS, 0, "unknown 12" }, 464 { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 1 permission fault" }, 465 { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 2 permission fault" }, 466 { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 3 permission fault" }, 467 { do_bad, SIGBUS, 0, "synchronous external abort" }, 468 { do_bad, SIGBUS, 0, "unknown 17" }, 469 { do_bad, SIGBUS, 0, "unknown 18" }, 470 { do_bad, SIGBUS, 0, "unknown 19" }, 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 abort (translation table walk)" }, 475 { do_bad, SIGBUS, 0, "synchronous parity error" }, 476 { do_bad, SIGBUS, 0, "unknown 25" }, 477 { do_bad, SIGBUS, 0, "unknown 26" }, 478 { do_bad, SIGBUS, 0, "unknown 27" }, 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, "synchronous parity error (translation table walk)" }, 483 { do_bad, SIGBUS, 0, "unknown 32" }, 484 { do_alignment_fault, SIGBUS, BUS_ADRALN, "alignment fault" }, 485 { do_bad, SIGBUS, 0, "unknown 34" }, 486 { do_bad, SIGBUS, 0, "unknown 35" }, 487 { do_bad, SIGBUS, 0, "unknown 36" }, 488 { do_bad, SIGBUS, 0, "unknown 37" }, 489 { do_bad, SIGBUS, 0, "unknown 38" }, 490 { do_bad, SIGBUS, 0, "unknown 39" }, 491 { do_bad, SIGBUS, 0, "unknown 40" }, 492 { do_bad, SIGBUS, 0, "unknown 41" }, 493 { do_bad, SIGBUS, 0, "unknown 42" }, 494 { do_bad, SIGBUS, 0, "unknown 43" }, 495 { do_bad, SIGBUS, 0, "unknown 44" }, 496 { do_bad, SIGBUS, 0, "unknown 45" }, 497 { do_bad, SIGBUS, 0, "unknown 46" }, 498 { do_bad, SIGBUS, 0, "unknown 47" }, 499 { do_bad, SIGBUS, 0, "TLB conflict abort" }, 500 { do_bad, SIGBUS, 0, "unknown 49" }, 501 { do_bad, SIGBUS, 0, "unknown 50" }, 502 { do_bad, SIGBUS, 0, "unknown 51" }, 503 { do_bad, SIGBUS, 0, "implementation fault (lockdown abort)" }, 504 { do_bad, SIGBUS, 0, "implementation fault (unsupported exclusive)" }, 505 { do_bad, SIGBUS, 0, "unknown 54" }, 506 { do_bad, SIGBUS, 0, "unknown 55" }, 507 { do_bad, SIGBUS, 0, "unknown 56" }, 508 { do_bad, SIGBUS, 0, "unknown 57" }, 509 { do_bad, SIGBUS, 0, "unknown 58" }, 510 { do_bad, SIGBUS, 0, "unknown 59" }, 511 { do_bad, SIGBUS, 0, "unknown 60" }, 512 { do_bad, SIGBUS, 0, "section domain fault" }, 513 { do_bad, SIGBUS, 0, "page domain fault" }, 514 { do_bad, SIGBUS, 0, "unknown 63" }, 515 }; 516 517 static const char *fault_name(unsigned int esr) 518 { 519 const struct fault_info *inf = fault_info + (esr & 63); 520 return inf->name; 521 } 522 523 /* 524 * Dispatch a data abort to the relevant handler. 525 */ 526 asmlinkage void __exception do_mem_abort(unsigned long addr, unsigned int esr, 527 struct pt_regs *regs) 528 { 529 const struct fault_info *inf = fault_info + (esr & 63); 530 struct siginfo info; 531 532 if (!inf->fn(addr, esr, regs)) 533 return; 534 535 pr_alert("Unhandled fault: %s (0x%08x) at 0x%016lx\n", 536 inf->name, esr, addr); 537 538 info.si_signo = inf->sig; 539 info.si_errno = 0; 540 info.si_code = inf->code; 541 info.si_addr = (void __user *)addr; 542 arm64_notify_die("", regs, &info, esr); 543 } 544 545 /* 546 * Handle stack alignment exceptions. 547 */ 548 asmlinkage void __exception do_sp_pc_abort(unsigned long addr, 549 unsigned int esr, 550 struct pt_regs *regs) 551 { 552 struct siginfo info; 553 struct task_struct *tsk = current; 554 555 if (show_unhandled_signals && unhandled_signal(tsk, SIGBUS)) 556 pr_info_ratelimited("%s[%d]: %s exception: pc=%p sp=%p\n", 557 tsk->comm, task_pid_nr(tsk), 558 esr_get_class_string(esr), (void *)regs->pc, 559 (void *)regs->sp); 560 561 info.si_signo = SIGBUS; 562 info.si_errno = 0; 563 info.si_code = BUS_ADRALN; 564 info.si_addr = (void __user *)addr; 565 arm64_notify_die("Oops - SP/PC alignment exception", regs, &info, esr); 566 } 567 568 int __init early_brk64(unsigned long addr, unsigned int esr, 569 struct pt_regs *regs); 570 571 /* 572 * __refdata because early_brk64 is __init, but the reference to it is 573 * clobbered at arch_initcall time. 574 * See traps.c and debug-monitors.c:debug_traps_init(). 575 */ 576 static struct fault_info __refdata debug_fault_info[] = { 577 { do_bad, SIGTRAP, TRAP_HWBKPT, "hardware breakpoint" }, 578 { do_bad, SIGTRAP, TRAP_HWBKPT, "hardware single-step" }, 579 { do_bad, SIGTRAP, TRAP_HWBKPT, "hardware watchpoint" }, 580 { do_bad, SIGBUS, 0, "unknown 3" }, 581 { do_bad, SIGTRAP, TRAP_BRKPT, "aarch32 BKPT" }, 582 { do_bad, SIGTRAP, 0, "aarch32 vector catch" }, 583 { early_brk64, SIGTRAP, TRAP_BRKPT, "aarch64 BRK" }, 584 { do_bad, SIGBUS, 0, "unknown 7" }, 585 }; 586 587 void __init hook_debug_fault_code(int nr, 588 int (*fn)(unsigned long, unsigned int, struct pt_regs *), 589 int sig, int code, const char *name) 590 { 591 BUG_ON(nr < 0 || nr >= ARRAY_SIZE(debug_fault_info)); 592 593 debug_fault_info[nr].fn = fn; 594 debug_fault_info[nr].sig = sig; 595 debug_fault_info[nr].code = code; 596 debug_fault_info[nr].name = name; 597 } 598 599 asmlinkage int __exception do_debug_exception(unsigned long addr, 600 unsigned int esr, 601 struct pt_regs *regs) 602 { 603 const struct fault_info *inf = debug_fault_info + DBG_ESR_EVT(esr); 604 struct siginfo info; 605 int rv; 606 607 /* 608 * Tell lockdep we disabled irqs in entry.S. Do nothing if they were 609 * already disabled to preserve the last enabled/disabled addresses. 610 */ 611 if (interrupts_enabled(regs)) 612 trace_hardirqs_off(); 613 614 if (!inf->fn(addr, esr, regs)) { 615 rv = 1; 616 } else { 617 pr_alert("Unhandled debug exception: %s (0x%08x) at 0x%016lx\n", 618 inf->name, esr, addr); 619 620 info.si_signo = inf->sig; 621 info.si_errno = 0; 622 info.si_code = inf->code; 623 info.si_addr = (void __user *)addr; 624 arm64_notify_die("", regs, &info, 0); 625 rv = 0; 626 } 627 628 if (interrupts_enabled(regs)) 629 trace_hardirqs_on(); 630 631 return rv; 632 } 633 634 #ifdef CONFIG_ARM64_PAN 635 void cpu_enable_pan(void *__unused) 636 { 637 config_sctlr_el1(SCTLR_EL1_SPAN, 0); 638 } 639 #endif /* CONFIG_ARM64_PAN */ 640 641 #ifdef CONFIG_ARM64_UAO 642 /* 643 * Kernel threads have fs=KERNEL_DS by default, and don't need to call 644 * set_fs(), devtmpfs in particular relies on this behaviour. 645 * We need to enable the feature at runtime (instead of adding it to 646 * PSR_MODE_EL1h) as the feature may not be implemented by the cpu. 647 */ 648 void cpu_enable_uao(void *__unused) 649 { 650 asm(SET_PSTATE_UAO(1)); 651 } 652 #endif /* CONFIG_ARM64_UAO */ 653