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 #ifdef CONFIG_KPROBES 45 static inline int notify_page_fault(struct pt_regs *regs, unsigned int esr) 46 { 47 int ret = 0; 48 49 /* kprobe_running() needs smp_processor_id() */ 50 if (!user_mode(regs)) { 51 preempt_disable(); 52 if (kprobe_running() && kprobe_fault_handler(regs, esr)) 53 ret = 1; 54 preempt_enable(); 55 } 56 57 return ret; 58 } 59 #else 60 static inline int notify_page_fault(struct pt_regs *regs, unsigned int esr) 61 { 62 return 0; 63 } 64 #endif 65 66 /* 67 * Dump out the page tables associated with 'addr' in mm 'mm'. 68 */ 69 void show_pte(struct mm_struct *mm, unsigned long addr) 70 { 71 pgd_t *pgd; 72 73 if (!mm) 74 mm = &init_mm; 75 76 pr_alert("pgd = %p\n", mm->pgd); 77 pgd = pgd_offset(mm, addr); 78 pr_alert("[%08lx] *pgd=%016llx", addr, pgd_val(*pgd)); 79 80 do { 81 pud_t *pud; 82 pmd_t *pmd; 83 pte_t *pte; 84 85 if (pgd_none(*pgd) || pgd_bad(*pgd)) 86 break; 87 88 pud = pud_offset(pgd, addr); 89 printk(", *pud=%016llx", pud_val(*pud)); 90 if (pud_none(*pud) || pud_bad(*pud)) 91 break; 92 93 pmd = pmd_offset(pud, addr); 94 printk(", *pmd=%016llx", pmd_val(*pmd)); 95 if (pmd_none(*pmd) || pmd_bad(*pmd)) 96 break; 97 98 pte = pte_offset_map(pmd, addr); 99 printk(", *pte=%016llx", pte_val(*pte)); 100 pte_unmap(pte); 101 } while(0); 102 103 printk("\n"); 104 } 105 106 #ifdef CONFIG_ARM64_HW_AFDBM 107 /* 108 * This function sets the access flags (dirty, accessed), as well as write 109 * permission, and only to a more permissive setting. 110 * 111 * It needs to cope with hardware update of the accessed/dirty state by other 112 * agents in the system and can safely skip the __sync_icache_dcache() call as, 113 * like set_pte_at(), the PTE is never changed from no-exec to exec here. 114 * 115 * Returns whether or not the PTE actually changed. 116 */ 117 int ptep_set_access_flags(struct vm_area_struct *vma, 118 unsigned long address, pte_t *ptep, 119 pte_t entry, int dirty) 120 { 121 pteval_t old_pteval; 122 unsigned int tmp; 123 124 if (pte_same(*ptep, entry)) 125 return 0; 126 127 /* only preserve the access flags and write permission */ 128 pte_val(entry) &= PTE_AF | PTE_WRITE | PTE_DIRTY; 129 130 /* 131 * PTE_RDONLY is cleared by default in the asm below, so set it in 132 * back if necessary (read-only or clean PTE). 133 */ 134 if (!pte_write(entry) || !pte_sw_dirty(entry)) 135 pte_val(entry) |= PTE_RDONLY; 136 137 /* 138 * Setting the flags must be done atomically to avoid racing with the 139 * hardware update of the access/dirty state. 140 */ 141 asm volatile("// ptep_set_access_flags\n" 142 " prfm pstl1strm, %2\n" 143 "1: ldxr %0, %2\n" 144 " and %0, %0, %3 // clear PTE_RDONLY\n" 145 " orr %0, %0, %4 // set flags\n" 146 " stxr %w1, %0, %2\n" 147 " cbnz %w1, 1b\n" 148 : "=&r" (old_pteval), "=&r" (tmp), "+Q" (pte_val(*ptep)) 149 : "L" (~PTE_RDONLY), "r" (pte_val(entry))); 150 151 flush_tlb_fix_spurious_fault(vma, address); 152 return 1; 153 } 154 #endif 155 156 /* 157 * The kernel tried to access some page that wasn't present. 158 */ 159 static void __do_kernel_fault(struct mm_struct *mm, unsigned long addr, 160 unsigned int esr, struct pt_regs *regs) 161 { 162 /* 163 * Are we prepared to handle this kernel fault? 164 */ 165 if (fixup_exception(regs)) 166 return; 167 168 /* 169 * No handler, we'll have to terminate things with extreme prejudice. 170 */ 171 bust_spinlocks(1); 172 pr_alert("Unable to handle kernel %s at virtual address %08lx\n", 173 (addr < PAGE_SIZE) ? "NULL pointer dereference" : 174 "paging request", addr); 175 176 show_pte(mm, addr); 177 die("Oops", regs, esr); 178 bust_spinlocks(0); 179 do_exit(SIGKILL); 180 } 181 182 /* 183 * Something tried to access memory that isn't in our memory map. User mode 184 * accesses just cause a SIGSEGV 185 */ 186 static void __do_user_fault(struct task_struct *tsk, unsigned long addr, 187 unsigned int esr, unsigned int sig, int code, 188 struct pt_regs *regs) 189 { 190 struct siginfo si; 191 192 if (unhandled_signal(tsk, sig) && show_unhandled_signals_ratelimited()) { 193 pr_info("%s[%d]: unhandled %s (%d) at 0x%08lx, esr 0x%03x\n", 194 tsk->comm, task_pid_nr(tsk), fault_name(esr), sig, 195 addr, esr); 196 show_pte(tsk->mm, addr); 197 show_regs(regs); 198 } 199 200 tsk->thread.fault_address = addr; 201 tsk->thread.fault_code = esr; 202 si.si_signo = sig; 203 si.si_errno = 0; 204 si.si_code = code; 205 si.si_addr = (void __user *)addr; 206 force_sig_info(sig, &si, tsk); 207 } 208 209 static void do_bad_area(unsigned long addr, unsigned int esr, struct pt_regs *regs) 210 { 211 struct task_struct *tsk = current; 212 struct mm_struct *mm = tsk->active_mm; 213 214 /* 215 * If we are in kernel mode at this point, we have no context to 216 * handle this fault with. 217 */ 218 if (user_mode(regs)) 219 __do_user_fault(tsk, addr, esr, SIGSEGV, SEGV_MAPERR, regs); 220 else 221 __do_kernel_fault(mm, addr, esr, regs); 222 } 223 224 #define VM_FAULT_BADMAP 0x010000 225 #define VM_FAULT_BADACCESS 0x020000 226 227 #define ESR_LNX_EXEC (1 << 24) 228 229 static int __do_page_fault(struct mm_struct *mm, unsigned long addr, 230 unsigned int mm_flags, unsigned long vm_flags, 231 struct task_struct *tsk) 232 { 233 struct vm_area_struct *vma; 234 int fault; 235 236 vma = find_vma(mm, addr); 237 fault = VM_FAULT_BADMAP; 238 if (unlikely(!vma)) 239 goto out; 240 if (unlikely(vma->vm_start > addr)) 241 goto check_stack; 242 243 /* 244 * Ok, we have a good vm_area for this memory access, so we can handle 245 * it. 246 */ 247 good_area: 248 /* 249 * Check that the permissions on the VMA allow for the fault which 250 * occurred. If we encountered a write or exec fault, we must have 251 * appropriate permissions, otherwise we allow any permission. 252 */ 253 if (!(vma->vm_flags & vm_flags)) { 254 fault = VM_FAULT_BADACCESS; 255 goto out; 256 } 257 258 return handle_mm_fault(mm, vma, addr & PAGE_MASK, mm_flags); 259 260 check_stack: 261 if (vma->vm_flags & VM_GROWSDOWN && !expand_stack(vma, addr)) 262 goto good_area; 263 out: 264 return fault; 265 } 266 267 static inline int permission_fault(unsigned int esr) 268 { 269 unsigned int ec = (esr & ESR_ELx_EC_MASK) >> ESR_ELx_EC_SHIFT; 270 unsigned int fsc_type = esr & ESR_ELx_FSC_TYPE; 271 272 return (ec == ESR_ELx_EC_DABT_CUR && fsc_type == ESR_ELx_FSC_PERM); 273 } 274 275 static int __kprobes do_page_fault(unsigned long addr, unsigned int esr, 276 struct pt_regs *regs) 277 { 278 struct task_struct *tsk; 279 struct mm_struct *mm; 280 int fault, sig, code; 281 unsigned long vm_flags = VM_READ | VM_WRITE | VM_EXEC; 282 unsigned int mm_flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE; 283 284 if (notify_page_fault(regs, esr)) 285 return 0; 286 287 tsk = current; 288 mm = tsk->mm; 289 290 /* 291 * If we're in an interrupt or have no user context, we must not take 292 * the fault. 293 */ 294 if (faulthandler_disabled() || !mm) 295 goto no_context; 296 297 if (user_mode(regs)) 298 mm_flags |= FAULT_FLAG_USER; 299 300 if (esr & ESR_LNX_EXEC) { 301 vm_flags = VM_EXEC; 302 } else if ((esr & ESR_ELx_WNR) && !(esr & ESR_ELx_CM)) { 303 vm_flags = VM_WRITE; 304 mm_flags |= FAULT_FLAG_WRITE; 305 } 306 307 if (permission_fault(esr) && (addr < USER_DS)) { 308 if (get_fs() == KERNEL_DS) 309 die("Accessing user space memory with fs=KERNEL_DS", regs, esr); 310 311 if (!search_exception_tables(regs->pc)) 312 die("Accessing user space memory outside uaccess.h routines", regs, esr); 313 } 314 315 /* 316 * As per x86, we may deadlock here. However, since the kernel only 317 * validly references user space from well defined areas of the code, 318 * we can bug out early if this is from code which shouldn't. 319 */ 320 if (!down_read_trylock(&mm->mmap_sem)) { 321 if (!user_mode(regs) && !search_exception_tables(regs->pc)) 322 goto no_context; 323 retry: 324 down_read(&mm->mmap_sem); 325 } else { 326 /* 327 * The above down_read_trylock() might have succeeded in which 328 * case, we'll have missed the might_sleep() from down_read(). 329 */ 330 might_sleep(); 331 #ifdef CONFIG_DEBUG_VM 332 if (!user_mode(regs) && !search_exception_tables(regs->pc)) 333 goto no_context; 334 #endif 335 } 336 337 fault = __do_page_fault(mm, addr, mm_flags, vm_flags, tsk); 338 339 /* 340 * If we need to retry but a fatal signal is pending, handle the 341 * signal first. We do not need to release the mmap_sem because it 342 * would already be released in __lock_page_or_retry in mm/filemap.c. 343 */ 344 if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current)) 345 return 0; 346 347 /* 348 * Major/minor page fault accounting is only done on the initial 349 * attempt. If we go through a retry, it is extremely likely that the 350 * page will be found in page cache at that point. 351 */ 352 353 perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, addr); 354 if (mm_flags & FAULT_FLAG_ALLOW_RETRY) { 355 if (fault & VM_FAULT_MAJOR) { 356 tsk->maj_flt++; 357 perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1, regs, 358 addr); 359 } else { 360 tsk->min_flt++; 361 perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, 1, regs, 362 addr); 363 } 364 if (fault & VM_FAULT_RETRY) { 365 /* 366 * Clear FAULT_FLAG_ALLOW_RETRY to avoid any risk of 367 * starvation. 368 */ 369 mm_flags &= ~FAULT_FLAG_ALLOW_RETRY; 370 mm_flags |= FAULT_FLAG_TRIED; 371 goto retry; 372 } 373 } 374 375 up_read(&mm->mmap_sem); 376 377 /* 378 * Handle the "normal" case first - VM_FAULT_MAJOR 379 */ 380 if (likely(!(fault & (VM_FAULT_ERROR | VM_FAULT_BADMAP | 381 VM_FAULT_BADACCESS)))) 382 return 0; 383 384 /* 385 * If we are in kernel mode at this point, we have no context to 386 * handle this fault with. 387 */ 388 if (!user_mode(regs)) 389 goto no_context; 390 391 if (fault & VM_FAULT_OOM) { 392 /* 393 * We ran out of memory, call the OOM killer, and return to 394 * userspace (which will retry the fault, or kill us if we got 395 * oom-killed). 396 */ 397 pagefault_out_of_memory(); 398 return 0; 399 } 400 401 if (fault & VM_FAULT_SIGBUS) { 402 /* 403 * We had some memory, but were unable to successfully fix up 404 * this page fault. 405 */ 406 sig = SIGBUS; 407 code = BUS_ADRERR; 408 } else { 409 /* 410 * Something tried to access memory that isn't in our memory 411 * map. 412 */ 413 sig = SIGSEGV; 414 code = fault == VM_FAULT_BADACCESS ? 415 SEGV_ACCERR : SEGV_MAPERR; 416 } 417 418 __do_user_fault(tsk, addr, esr, sig, code, regs); 419 return 0; 420 421 no_context: 422 __do_kernel_fault(mm, addr, esr, regs); 423 return 0; 424 } 425 426 /* 427 * First Level Translation Fault Handler 428 * 429 * We enter here because the first level page table doesn't contain a valid 430 * entry for the address. 431 * 432 * If the address is in kernel space (>= TASK_SIZE), then we are probably 433 * faulting in the vmalloc() area. 434 * 435 * If the init_task's first level page tables contains the relevant entry, we 436 * copy the it to this task. If not, we send the process a signal, fixup the 437 * exception, or oops the kernel. 438 * 439 * NOTE! We MUST NOT take any locks for this case. We may be in an interrupt 440 * or a critical region, and should only copy the information from the master 441 * page table, nothing more. 442 */ 443 static int __kprobes do_translation_fault(unsigned long addr, 444 unsigned int esr, 445 struct pt_regs *regs) 446 { 447 if (addr < TASK_SIZE) 448 return do_page_fault(addr, esr, regs); 449 450 do_bad_area(addr, esr, regs); 451 return 0; 452 } 453 454 static int do_alignment_fault(unsigned long addr, unsigned int esr, 455 struct pt_regs *regs) 456 { 457 do_bad_area(addr, esr, regs); 458 return 0; 459 } 460 461 /* 462 * This abort handler always returns "fault". 463 */ 464 static int do_bad(unsigned long addr, unsigned int esr, struct pt_regs *regs) 465 { 466 return 1; 467 } 468 469 static const struct fault_info { 470 int (*fn)(unsigned long addr, unsigned int esr, struct pt_regs *regs); 471 int sig; 472 int code; 473 const char *name; 474 } fault_info[] = { 475 { do_bad, SIGBUS, 0, "ttbr address size fault" }, 476 { do_bad, SIGBUS, 0, "level 1 address size fault" }, 477 { do_bad, SIGBUS, 0, "level 2 address size fault" }, 478 { do_bad, SIGBUS, 0, "level 3 address size fault" }, 479 { do_translation_fault, SIGSEGV, SEGV_MAPERR, "level 0 translation fault" }, 480 { do_translation_fault, SIGSEGV, SEGV_MAPERR, "level 1 translation fault" }, 481 { do_translation_fault, SIGSEGV, SEGV_MAPERR, "level 2 translation fault" }, 482 { do_page_fault, SIGSEGV, SEGV_MAPERR, "level 3 translation fault" }, 483 { do_bad, SIGBUS, 0, "unknown 8" }, 484 { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 1 access flag fault" }, 485 { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 2 access flag fault" }, 486 { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 3 access flag fault" }, 487 { do_bad, SIGBUS, 0, "unknown 12" }, 488 { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 1 permission fault" }, 489 { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 2 permission fault" }, 490 { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 3 permission fault" }, 491 { do_bad, SIGBUS, 0, "synchronous external abort" }, 492 { do_bad, SIGBUS, 0, "unknown 17" }, 493 { do_bad, SIGBUS, 0, "unknown 18" }, 494 { do_bad, SIGBUS, 0, "unknown 19" }, 495 { do_bad, SIGBUS, 0, "synchronous abort (translation table walk)" }, 496 { do_bad, SIGBUS, 0, "synchronous abort (translation table walk)" }, 497 { do_bad, SIGBUS, 0, "synchronous abort (translation table walk)" }, 498 { do_bad, SIGBUS, 0, "synchronous abort (translation table walk)" }, 499 { do_bad, SIGBUS, 0, "synchronous parity error" }, 500 { do_bad, SIGBUS, 0, "unknown 25" }, 501 { do_bad, SIGBUS, 0, "unknown 26" }, 502 { do_bad, SIGBUS, 0, "unknown 27" }, 503 { do_bad, SIGBUS, 0, "synchronous parity error (translation table walk)" }, 504 { do_bad, SIGBUS, 0, "synchronous parity error (translation table walk)" }, 505 { do_bad, SIGBUS, 0, "synchronous parity error (translation table walk)" }, 506 { do_bad, SIGBUS, 0, "synchronous parity error (translation table walk)" }, 507 { do_bad, SIGBUS, 0, "unknown 32" }, 508 { do_alignment_fault, SIGBUS, BUS_ADRALN, "alignment fault" }, 509 { do_bad, SIGBUS, 0, "unknown 34" }, 510 { do_bad, SIGBUS, 0, "unknown 35" }, 511 { do_bad, SIGBUS, 0, "unknown 36" }, 512 { do_bad, SIGBUS, 0, "unknown 37" }, 513 { do_bad, SIGBUS, 0, "unknown 38" }, 514 { do_bad, SIGBUS, 0, "unknown 39" }, 515 { do_bad, SIGBUS, 0, "unknown 40" }, 516 { do_bad, SIGBUS, 0, "unknown 41" }, 517 { do_bad, SIGBUS, 0, "unknown 42" }, 518 { do_bad, SIGBUS, 0, "unknown 43" }, 519 { do_bad, SIGBUS, 0, "unknown 44" }, 520 { do_bad, SIGBUS, 0, "unknown 45" }, 521 { do_bad, SIGBUS, 0, "unknown 46" }, 522 { do_bad, SIGBUS, 0, "unknown 47" }, 523 { do_bad, SIGBUS, 0, "TLB conflict abort" }, 524 { do_bad, SIGBUS, 0, "unknown 49" }, 525 { do_bad, SIGBUS, 0, "unknown 50" }, 526 { do_bad, SIGBUS, 0, "unknown 51" }, 527 { do_bad, SIGBUS, 0, "implementation fault (lockdown abort)" }, 528 { do_bad, SIGBUS, 0, "implementation fault (unsupported exclusive)" }, 529 { do_bad, SIGBUS, 0, "unknown 54" }, 530 { do_bad, SIGBUS, 0, "unknown 55" }, 531 { do_bad, SIGBUS, 0, "unknown 56" }, 532 { do_bad, SIGBUS, 0, "unknown 57" }, 533 { do_bad, SIGBUS, 0, "unknown 58" }, 534 { do_bad, SIGBUS, 0, "unknown 59" }, 535 { do_bad, SIGBUS, 0, "unknown 60" }, 536 { do_bad, SIGBUS, 0, "section domain fault" }, 537 { do_bad, SIGBUS, 0, "page domain fault" }, 538 { do_bad, SIGBUS, 0, "unknown 63" }, 539 }; 540 541 static const char *fault_name(unsigned int esr) 542 { 543 const struct fault_info *inf = fault_info + (esr & 63); 544 return inf->name; 545 } 546 547 /* 548 * Dispatch a data abort to the relevant handler. 549 */ 550 asmlinkage void __exception do_mem_abort(unsigned long addr, unsigned int esr, 551 struct pt_regs *regs) 552 { 553 const struct fault_info *inf = fault_info + (esr & 63); 554 struct siginfo info; 555 556 if (!inf->fn(addr, esr, regs)) 557 return; 558 559 pr_alert("Unhandled fault: %s (0x%08x) at 0x%016lx\n", 560 inf->name, esr, addr); 561 562 info.si_signo = inf->sig; 563 info.si_errno = 0; 564 info.si_code = inf->code; 565 info.si_addr = (void __user *)addr; 566 arm64_notify_die("", regs, &info, esr); 567 } 568 569 /* 570 * Handle stack alignment exceptions. 571 */ 572 asmlinkage void __exception do_sp_pc_abort(unsigned long addr, 573 unsigned int esr, 574 struct pt_regs *regs) 575 { 576 struct siginfo info; 577 struct task_struct *tsk = current; 578 579 if (show_unhandled_signals && unhandled_signal(tsk, SIGBUS)) 580 pr_info_ratelimited("%s[%d]: %s exception: pc=%p sp=%p\n", 581 tsk->comm, task_pid_nr(tsk), 582 esr_get_class_string(esr), (void *)regs->pc, 583 (void *)regs->sp); 584 585 info.si_signo = SIGBUS; 586 info.si_errno = 0; 587 info.si_code = BUS_ADRALN; 588 info.si_addr = (void __user *)addr; 589 arm64_notify_die("Oops - SP/PC alignment exception", regs, &info, esr); 590 } 591 592 int __init early_brk64(unsigned long addr, unsigned int esr, 593 struct pt_regs *regs); 594 595 /* 596 * __refdata because early_brk64 is __init, but the reference to it is 597 * clobbered at arch_initcall time. 598 * See traps.c and debug-monitors.c:debug_traps_init(). 599 */ 600 static struct fault_info __refdata debug_fault_info[] = { 601 { do_bad, SIGTRAP, TRAP_HWBKPT, "hardware breakpoint" }, 602 { do_bad, SIGTRAP, TRAP_HWBKPT, "hardware single-step" }, 603 { do_bad, SIGTRAP, TRAP_HWBKPT, "hardware watchpoint" }, 604 { do_bad, SIGBUS, 0, "unknown 3" }, 605 { do_bad, SIGTRAP, TRAP_BRKPT, "aarch32 BKPT" }, 606 { do_bad, SIGTRAP, 0, "aarch32 vector catch" }, 607 { early_brk64, SIGTRAP, TRAP_BRKPT, "aarch64 BRK" }, 608 { do_bad, SIGBUS, 0, "unknown 7" }, 609 }; 610 611 void __init hook_debug_fault_code(int nr, 612 int (*fn)(unsigned long, unsigned int, struct pt_regs *), 613 int sig, int code, const char *name) 614 { 615 BUG_ON(nr < 0 || nr >= ARRAY_SIZE(debug_fault_info)); 616 617 debug_fault_info[nr].fn = fn; 618 debug_fault_info[nr].sig = sig; 619 debug_fault_info[nr].code = code; 620 debug_fault_info[nr].name = name; 621 } 622 623 asmlinkage int __exception do_debug_exception(unsigned long addr, 624 unsigned int esr, 625 struct pt_regs *regs) 626 { 627 const struct fault_info *inf = debug_fault_info + DBG_ESR_EVT(esr); 628 struct siginfo info; 629 int rv; 630 631 /* 632 * Tell lockdep we disabled irqs in entry.S. Do nothing if they were 633 * already disabled to preserve the last enabled/disabled addresses. 634 */ 635 if (interrupts_enabled(regs)) 636 trace_hardirqs_off(); 637 638 if (!inf->fn(addr, esr, regs)) { 639 rv = 1; 640 } else { 641 pr_alert("Unhandled debug exception: %s (0x%08x) at 0x%016lx\n", 642 inf->name, esr, addr); 643 644 info.si_signo = inf->sig; 645 info.si_errno = 0; 646 info.si_code = inf->code; 647 info.si_addr = (void __user *)addr; 648 arm64_notify_die("", regs, &info, 0); 649 rv = 0; 650 } 651 652 if (interrupts_enabled(regs)) 653 trace_hardirqs_on(); 654 655 return rv; 656 } 657 NOKPROBE_SYMBOL(do_debug_exception); 658 659 #ifdef CONFIG_ARM64_PAN 660 void cpu_enable_pan(void *__unused) 661 { 662 config_sctlr_el1(SCTLR_EL1_SPAN, 0); 663 } 664 #endif /* CONFIG_ARM64_PAN */ 665 666 #ifdef CONFIG_ARM64_UAO 667 /* 668 * Kernel threads have fs=KERNEL_DS by default, and don't need to call 669 * set_fs(), devtmpfs in particular relies on this behaviour. 670 * We need to enable the feature at runtime (instead of adding it to 671 * PSR_MODE_EL1h) as the feature may not be implemented by the cpu. 672 */ 673 void cpu_enable_uao(void *__unused) 674 { 675 asm(SET_PSTATE_UAO(1)); 676 } 677 #endif /* CONFIG_ARM64_UAO */ 678