2 * Based on arch/arm/mm/fault.c
4 * Copyright (C) 1995 Linus Torvalds
5 * Copyright (C) 1995-2004 Russell King
6 * Copyright (C) 2012 ARM Ltd.
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.
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.
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/>.
21 #include <linux/extable.h>
22 #include <linux/signal.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/signal.h>
30 #include <linux/sched/debug.h>
31 #include <linux/highmem.h>
32 #include <linux/perf_event.h>
33 #include <linux/preempt.h>
34 #include <linux/hugetlb.h>
37 #include <asm/cmpxchg.h>
38 #include <asm/cpufeature.h>
39 #include <asm/exception.h>
40 #include <asm/debug-monitors.h>
42 #include <asm/sysreg.h>
43 #include <asm/system_misc.h>
44 #include <asm/pgtable.h>
45 #include <asm/tlbflush.h>
47 #include <acpi/ghes.h>
50 int (*fn)(unsigned long addr, unsigned int esr,
51 struct pt_regs *regs);
57 static const struct fault_info fault_info[];
59 static inline const struct fault_info *esr_to_fault_info(unsigned int esr)
61 return fault_info + (esr & 63);
65 static inline int notify_page_fault(struct pt_regs *regs, unsigned int esr)
69 /* kprobe_running() needs smp_processor_id() */
70 if (!user_mode(regs)) {
72 if (kprobe_running() && kprobe_fault_handler(regs, esr))
80 static inline int notify_page_fault(struct pt_regs *regs, unsigned int esr)
86 static void data_abort_decode(unsigned int esr)
88 pr_alert("Data abort info:\n");
90 if (esr & ESR_ELx_ISV) {
91 pr_alert(" Access size = %u byte(s)\n",
92 1U << ((esr & ESR_ELx_SAS) >> ESR_ELx_SAS_SHIFT));
93 pr_alert(" SSE = %lu, SRT = %lu\n",
94 (esr & ESR_ELx_SSE) >> ESR_ELx_SSE_SHIFT,
95 (esr & ESR_ELx_SRT_MASK) >> ESR_ELx_SRT_SHIFT);
96 pr_alert(" SF = %lu, AR = %lu\n",
97 (esr & ESR_ELx_SF) >> ESR_ELx_SF_SHIFT,
98 (esr & ESR_ELx_AR) >> ESR_ELx_AR_SHIFT);
100 pr_alert(" ISV = 0, ISS = 0x%08lx\n", esr & ESR_ELx_ISS_MASK);
103 pr_alert(" CM = %lu, WnR = %lu\n",
104 (esr & ESR_ELx_CM) >> ESR_ELx_CM_SHIFT,
105 (esr & ESR_ELx_WNR) >> ESR_ELx_WNR_SHIFT);
108 static void mem_abort_decode(unsigned int esr)
110 pr_alert("Mem abort info:\n");
112 pr_alert(" ESR = 0x%08x\n", esr);
113 pr_alert(" Exception class = %s, IL = %u bits\n",
114 esr_get_class_string(esr),
115 (esr & ESR_ELx_IL) ? 32 : 16);
116 pr_alert(" SET = %lu, FnV = %lu\n",
117 (esr & ESR_ELx_SET_MASK) >> ESR_ELx_SET_SHIFT,
118 (esr & ESR_ELx_FnV) >> ESR_ELx_FnV_SHIFT);
119 pr_alert(" EA = %lu, S1PTW = %lu\n",
120 (esr & ESR_ELx_EA) >> ESR_ELx_EA_SHIFT,
121 (esr & ESR_ELx_S1PTW) >> ESR_ELx_S1PTW_SHIFT);
123 if (esr_is_data_abort(esr))
124 data_abort_decode(esr);
128 * Dump out the page tables associated with 'addr' in the currently active mm.
130 void show_pte(unsigned long addr)
132 struct mm_struct *mm;
135 if (addr < TASK_SIZE) {
137 mm = current->active_mm;
138 if (mm == &init_mm) {
139 pr_alert("[%016lx] user address but active_mm is swapper\n",
143 } else if (addr >= VA_START) {
147 pr_alert("[%016lx] address between user and kernel address ranges\n",
152 pr_alert("%s pgtable: %luk pages, %u-bit VAs, pgd = %p\n",
153 mm == &init_mm ? "swapper" : "user", PAGE_SIZE / SZ_1K,
155 pgd = pgd_offset(mm, addr);
156 pr_alert("[%016lx] *pgd=%016llx", addr, pgd_val(*pgd));
163 if (pgd_none(*pgd) || pgd_bad(*pgd))
166 pud = pud_offset(pgd, addr);
167 pr_cont(", *pud=%016llx", pud_val(*pud));
168 if (pud_none(*pud) || pud_bad(*pud))
171 pmd = pmd_offset(pud, addr);
172 pr_cont(", *pmd=%016llx", pmd_val(*pmd));
173 if (pmd_none(*pmd) || pmd_bad(*pmd))
176 pte = pte_offset_map(pmd, addr);
177 pr_cont(", *pte=%016llx", pte_val(*pte));
185 * This function sets the access flags (dirty, accessed), as well as write
186 * permission, and only to a more permissive setting.
188 * It needs to cope with hardware update of the accessed/dirty state by other
189 * agents in the system and can safely skip the __sync_icache_dcache() call as,
190 * like set_pte_at(), the PTE is never changed from no-exec to exec here.
192 * Returns whether or not the PTE actually changed.
194 int ptep_set_access_flags(struct vm_area_struct *vma,
195 unsigned long address, pte_t *ptep,
196 pte_t entry, int dirty)
198 pteval_t old_pteval, pteval;
200 if (pte_same(*ptep, entry))
203 /* only preserve the access flags and write permission */
204 pte_val(entry) &= PTE_RDONLY | PTE_AF | PTE_WRITE | PTE_DIRTY;
207 * Setting the flags must be done atomically to avoid racing with the
208 * hardware update of the access/dirty state. The PTE_RDONLY bit must
209 * be set to the most permissive (lowest value) of *ptep and entry
210 * (calculated as: a & b == ~(~a | ~b)).
212 pte_val(entry) ^= PTE_RDONLY;
213 pteval = READ_ONCE(pte_val(*ptep));
216 pteval ^= PTE_RDONLY;
217 pteval |= pte_val(entry);
218 pteval ^= PTE_RDONLY;
219 pteval = cmpxchg_relaxed(&pte_val(*ptep), old_pteval, pteval);
220 } while (pteval != old_pteval);
222 flush_tlb_fix_spurious_fault(vma, address);
226 static bool is_el1_instruction_abort(unsigned int esr)
228 return ESR_ELx_EC(esr) == ESR_ELx_EC_IABT_CUR;
231 static inline bool is_permission_fault(unsigned int esr, struct pt_regs *regs,
234 unsigned int ec = ESR_ELx_EC(esr);
235 unsigned int fsc_type = esr & ESR_ELx_FSC_TYPE;
237 if (ec != ESR_ELx_EC_DABT_CUR && ec != ESR_ELx_EC_IABT_CUR)
240 if (fsc_type == ESR_ELx_FSC_PERM)
243 if (addr < TASK_SIZE && system_uses_ttbr0_pan())
244 return fsc_type == ESR_ELx_FSC_FAULT &&
245 (regs->pstate & PSR_PAN_BIT);
250 static void __do_kernel_fault(unsigned long addr, unsigned int esr,
251 struct pt_regs *regs)
256 * Are we prepared to handle this kernel fault?
257 * We are almost certainly not prepared to handle instruction faults.
259 if (!is_el1_instruction_abort(esr) && fixup_exception(regs))
264 if (is_permission_fault(esr, regs, addr)) {
265 if (esr & ESR_ELx_WNR)
266 msg = "write to read-only memory";
268 msg = "read from unreadable memory";
269 } else if (addr < PAGE_SIZE) {
270 msg = "NULL pointer dereference";
272 msg = "paging request";
275 pr_alert("Unable to handle kernel %s at virtual address %08lx\n", msg,
278 mem_abort_decode(esr);
281 die("Oops", regs, esr);
286 static void __do_user_fault(struct task_struct *tsk, unsigned long addr,
287 unsigned int esr, unsigned int sig, int code,
288 struct pt_regs *regs, int fault)
291 const struct fault_info *inf;
292 unsigned int lsb = 0;
294 if (unhandled_signal(tsk, sig) && show_unhandled_signals_ratelimited()) {
295 inf = esr_to_fault_info(esr);
296 pr_info("%s[%d]: unhandled %s (%d) at 0x%08lx, esr 0x%03x",
297 tsk->comm, task_pid_nr(tsk), inf->name, sig,
299 print_vma_addr(KERN_CONT ", in ", regs->pc);
304 tsk->thread.fault_address = addr;
305 tsk->thread.fault_code = esr;
309 si.si_addr = (void __user *)addr;
311 * Either small page or large page may be poisoned.
312 * In other words, VM_FAULT_HWPOISON_LARGE and
313 * VM_FAULT_HWPOISON are mutually exclusive.
315 if (fault & VM_FAULT_HWPOISON_LARGE)
316 lsb = hstate_index_to_shift(VM_FAULT_GET_HINDEX(fault));
317 else if (fault & VM_FAULT_HWPOISON)
319 si.si_addr_lsb = lsb;
321 force_sig_info(sig, &si, tsk);
324 static void do_bad_area(unsigned long addr, unsigned int esr, struct pt_regs *regs)
326 struct task_struct *tsk = current;
327 const struct fault_info *inf;
330 * If we are in kernel mode at this point, we have no context to
331 * handle this fault with.
333 if (user_mode(regs)) {
334 inf = esr_to_fault_info(esr);
335 __do_user_fault(tsk, addr, esr, inf->sig, inf->code, regs, 0);
337 __do_kernel_fault(addr, esr, regs);
340 #define VM_FAULT_BADMAP 0x010000
341 #define VM_FAULT_BADACCESS 0x020000
343 static int __do_page_fault(struct mm_struct *mm, unsigned long addr,
344 unsigned int mm_flags, unsigned long vm_flags,
345 struct task_struct *tsk)
347 struct vm_area_struct *vma;
350 vma = find_vma(mm, addr);
351 fault = VM_FAULT_BADMAP;
354 if (unlikely(vma->vm_start > addr))
358 * Ok, we have a good vm_area for this memory access, so we can handle
363 * Check that the permissions on the VMA allow for the fault which
366 if (!(vma->vm_flags & vm_flags)) {
367 fault = VM_FAULT_BADACCESS;
371 return handle_mm_fault(vma, addr & PAGE_MASK, mm_flags);
374 if (vma->vm_flags & VM_GROWSDOWN && !expand_stack(vma, addr))
380 static bool is_el0_instruction_abort(unsigned int esr)
382 return ESR_ELx_EC(esr) == ESR_ELx_EC_IABT_LOW;
385 static int __kprobes do_page_fault(unsigned long addr, unsigned int esr,
386 struct pt_regs *regs)
388 struct task_struct *tsk;
389 struct mm_struct *mm;
390 int fault, sig, code, major = 0;
391 unsigned long vm_flags = VM_READ | VM_WRITE;
392 unsigned int mm_flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
394 if (notify_page_fault(regs, esr))
401 * If we're in an interrupt or have no user context, we must not take
404 if (faulthandler_disabled() || !mm)
408 mm_flags |= FAULT_FLAG_USER;
410 if (is_el0_instruction_abort(esr)) {
412 } else if ((esr & ESR_ELx_WNR) && !(esr & ESR_ELx_CM)) {
414 mm_flags |= FAULT_FLAG_WRITE;
417 if (addr < TASK_SIZE && is_permission_fault(esr, regs, addr)) {
418 /* regs->orig_addr_limit may be 0 if we entered from EL0 */
419 if (regs->orig_addr_limit == KERNEL_DS)
420 die("Accessing user space memory with fs=KERNEL_DS", regs, esr);
422 if (is_el1_instruction_abort(esr))
423 die("Attempting to execute userspace memory", regs, esr);
425 if (!search_exception_tables(regs->pc))
426 die("Accessing user space memory outside uaccess.h routines", regs, esr);
429 perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, addr);
432 * As per x86, we may deadlock here. However, since the kernel only
433 * validly references user space from well defined areas of the code,
434 * we can bug out early if this is from code which shouldn't.
436 if (!down_read_trylock(&mm->mmap_sem)) {
437 if (!user_mode(regs) && !search_exception_tables(regs->pc))
440 down_read(&mm->mmap_sem);
443 * The above down_read_trylock() might have succeeded in which
444 * case, we'll have missed the might_sleep() from down_read().
447 #ifdef CONFIG_DEBUG_VM
448 if (!user_mode(regs) && !search_exception_tables(regs->pc))
453 fault = __do_page_fault(mm, addr, mm_flags, vm_flags, tsk);
454 major |= fault & VM_FAULT_MAJOR;
456 if (fault & VM_FAULT_RETRY) {
458 * If we need to retry but a fatal signal is pending,
459 * handle the signal first. We do not need to release
460 * the mmap_sem because it would already be released
461 * in __lock_page_or_retry in mm/filemap.c.
463 if (fatal_signal_pending(current)) {
464 if (!user_mode(regs))
470 * Clear FAULT_FLAG_ALLOW_RETRY to avoid any risk of
473 if (mm_flags & FAULT_FLAG_ALLOW_RETRY) {
474 mm_flags &= ~FAULT_FLAG_ALLOW_RETRY;
475 mm_flags |= FAULT_FLAG_TRIED;
479 up_read(&mm->mmap_sem);
482 * Handle the "normal" (no error) case first.
484 if (likely(!(fault & (VM_FAULT_ERROR | VM_FAULT_BADMAP |
485 VM_FAULT_BADACCESS)))) {
487 * Major/minor page fault accounting is only done
488 * once. If we go through a retry, it is extremely
489 * likely that the page will be found in page cache at
494 perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1, regs,
498 perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, 1, regs,
506 * If we are in kernel mode at this point, we have no context to
507 * handle this fault with.
509 if (!user_mode(regs))
512 if (fault & VM_FAULT_OOM) {
514 * We ran out of memory, call the OOM killer, and return to
515 * userspace (which will retry the fault, or kill us if we got
518 pagefault_out_of_memory();
522 if (fault & VM_FAULT_SIGBUS) {
524 * We had some memory, but were unable to successfully fix up
529 } else if (fault & (VM_FAULT_HWPOISON | VM_FAULT_HWPOISON_LARGE)) {
531 code = BUS_MCEERR_AR;
534 * Something tried to access memory that isn't in our memory
538 code = fault == VM_FAULT_BADACCESS ?
539 SEGV_ACCERR : SEGV_MAPERR;
542 __do_user_fault(tsk, addr, esr, sig, code, regs, fault);
546 __do_kernel_fault(addr, esr, regs);
550 static int __kprobes do_translation_fault(unsigned long addr,
552 struct pt_regs *regs)
554 if (addr < TASK_SIZE)
555 return do_page_fault(addr, esr, regs);
557 do_bad_area(addr, esr, regs);
561 static int do_alignment_fault(unsigned long addr, unsigned int esr,
562 struct pt_regs *regs)
564 do_bad_area(addr, esr, regs);
568 static int do_bad(unsigned long addr, unsigned int esr, struct pt_regs *regs)
570 return 1; /* "fault" */
573 static int do_sea(unsigned long addr, unsigned int esr, struct pt_regs *regs)
576 const struct fault_info *inf;
578 inf = esr_to_fault_info(esr);
579 pr_err("Synchronous External Abort: %s (0x%08x) at 0x%016lx\n",
580 inf->name, esr, addr);
583 * Synchronous aborts may interrupt code which had interrupts masked.
584 * Before calling out into the wider kernel tell the interested
587 if (IS_ENABLED(CONFIG_ACPI_APEI_SEA)) {
588 if (interrupts_enabled(regs))
593 if (interrupts_enabled(regs))
597 info.si_signo = SIGBUS;
599 info.si_code = BUS_FIXME;
600 if (esr & ESR_ELx_FnV)
603 info.si_addr = (void __user *)addr;
604 arm64_notify_die("", regs, &info, esr);
609 static const struct fault_info fault_info[] = {
610 { do_bad, SIGBUS, BUS_FIXME, "ttbr address size fault" },
611 { do_bad, SIGBUS, BUS_FIXME, "level 1 address size fault" },
612 { do_bad, SIGBUS, BUS_FIXME, "level 2 address size fault" },
613 { do_bad, SIGBUS, BUS_FIXME, "level 3 address size fault" },
614 { do_translation_fault, SIGSEGV, SEGV_MAPERR, "level 0 translation fault" },
615 { do_translation_fault, SIGSEGV, SEGV_MAPERR, "level 1 translation fault" },
616 { do_translation_fault, SIGSEGV, SEGV_MAPERR, "level 2 translation fault" },
617 { do_translation_fault, SIGSEGV, SEGV_MAPERR, "level 3 translation fault" },
618 { do_bad, SIGBUS, BUS_FIXME, "unknown 8" },
619 { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 1 access flag fault" },
620 { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 2 access flag fault" },
621 { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 3 access flag fault" },
622 { do_bad, SIGBUS, BUS_FIXME, "unknown 12" },
623 { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 1 permission fault" },
624 { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 2 permission fault" },
625 { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 3 permission fault" },
626 { do_sea, SIGBUS, BUS_FIXME, "synchronous external abort" },
627 { do_bad, SIGBUS, BUS_FIXME, "unknown 17" },
628 { do_bad, SIGBUS, BUS_FIXME, "unknown 18" },
629 { do_bad, SIGBUS, BUS_FIXME, "unknown 19" },
630 { do_sea, SIGBUS, BUS_FIXME, "level 0 (translation table walk)" },
631 { do_sea, SIGBUS, BUS_FIXME, "level 1 (translation table walk)" },
632 { do_sea, SIGBUS, BUS_FIXME, "level 2 (translation table walk)" },
633 { do_sea, SIGBUS, BUS_FIXME, "level 3 (translation table walk)" },
634 { do_sea, SIGBUS, BUS_FIXME, "synchronous parity or ECC error" }, // Reserved when RAS is implemented
635 { do_bad, SIGBUS, BUS_FIXME, "unknown 25" },
636 { do_bad, SIGBUS, BUS_FIXME, "unknown 26" },
637 { do_bad, SIGBUS, BUS_FIXME, "unknown 27" },
638 { do_sea, SIGBUS, BUS_FIXME, "level 0 synchronous parity error (translation table walk)" }, // Reserved when RAS is implemented
639 { do_sea, SIGBUS, BUS_FIXME, "level 1 synchronous parity error (translation table walk)" }, // Reserved when RAS is implemented
640 { do_sea, SIGBUS, BUS_FIXME, "level 2 synchronous parity error (translation table walk)" }, // Reserved when RAS is implemented
641 { do_sea, SIGBUS, BUS_FIXME, "level 3 synchronous parity error (translation table walk)" }, // Reserved when RAS is implemented
642 { do_bad, SIGBUS, BUS_FIXME, "unknown 32" },
643 { do_alignment_fault, SIGBUS, BUS_ADRALN, "alignment fault" },
644 { do_bad, SIGBUS, BUS_FIXME, "unknown 34" },
645 { do_bad, SIGBUS, BUS_FIXME, "unknown 35" },
646 { do_bad, SIGBUS, BUS_FIXME, "unknown 36" },
647 { do_bad, SIGBUS, BUS_FIXME, "unknown 37" },
648 { do_bad, SIGBUS, BUS_FIXME, "unknown 38" },
649 { do_bad, SIGBUS, BUS_FIXME, "unknown 39" },
650 { do_bad, SIGBUS, BUS_FIXME, "unknown 40" },
651 { do_bad, SIGBUS, BUS_FIXME, "unknown 41" },
652 { do_bad, SIGBUS, BUS_FIXME, "unknown 42" },
653 { do_bad, SIGBUS, BUS_FIXME, "unknown 43" },
654 { do_bad, SIGBUS, BUS_FIXME, "unknown 44" },
655 { do_bad, SIGBUS, BUS_FIXME, "unknown 45" },
656 { do_bad, SIGBUS, BUS_FIXME, "unknown 46" },
657 { do_bad, SIGBUS, BUS_FIXME, "unknown 47" },
658 { do_bad, SIGBUS, BUS_FIXME, "TLB conflict abort" },
659 { do_bad, SIGBUS, BUS_FIXME, "Unsupported atomic hardware update fault" },
660 { do_bad, SIGBUS, BUS_FIXME, "unknown 50" },
661 { do_bad, SIGBUS, BUS_FIXME, "unknown 51" },
662 { do_bad, SIGBUS, BUS_FIXME, "implementation fault (lockdown abort)" },
663 { do_bad, SIGBUS, BUS_FIXME, "implementation fault (unsupported exclusive)" },
664 { do_bad, SIGBUS, BUS_FIXME, "unknown 54" },
665 { do_bad, SIGBUS, BUS_FIXME, "unknown 55" },
666 { do_bad, SIGBUS, BUS_FIXME, "unknown 56" },
667 { do_bad, SIGBUS, BUS_FIXME, "unknown 57" },
668 { do_bad, SIGBUS, BUS_FIXME, "unknown 58" },
669 { do_bad, SIGBUS, BUS_FIXME, "unknown 59" },
670 { do_bad, SIGBUS, BUS_FIXME, "unknown 60" },
671 { do_bad, SIGBUS, BUS_FIXME, "section domain fault" },
672 { do_bad, SIGBUS, BUS_FIXME, "page domain fault" },
673 { do_bad, SIGBUS, BUS_FIXME, "unknown 63" },
676 int handle_guest_sea(phys_addr_t addr, unsigned int esr)
680 if (IS_ENABLED(CONFIG_ACPI_APEI_SEA))
681 ret = ghes_notify_sea();
686 asmlinkage void __exception do_mem_abort(unsigned long addr, unsigned int esr,
687 struct pt_regs *regs)
689 const struct fault_info *inf = esr_to_fault_info(esr);
692 if (!inf->fn(addr, esr, regs))
695 pr_alert("Unhandled fault: %s at 0x%016lx\n",
698 mem_abort_decode(esr);
700 if (!user_mode(regs))
703 info.si_signo = inf->sig;
705 info.si_code = inf->code;
706 info.si_addr = (void __user *)addr;
707 arm64_notify_die("", regs, &info, esr);
710 asmlinkage void __exception do_el0_irq_bp_hardening(void)
712 /* PC has already been checked in entry.S */
713 arm64_apply_bp_hardening();
716 asmlinkage void __exception do_el0_ia_bp_hardening(unsigned long addr,
718 struct pt_regs *regs)
721 * We've taken an instruction abort from userspace and not yet
722 * re-enabled IRQs. If the address is a kernel address, apply
723 * BP hardening prior to enabling IRQs and pre-emption.
725 if (addr > TASK_SIZE)
726 arm64_apply_bp_hardening();
729 do_mem_abort(addr, esr, regs);
733 asmlinkage void __exception do_sp_pc_abort(unsigned long addr,
735 struct pt_regs *regs)
738 struct task_struct *tsk = current;
740 if (user_mode(regs)) {
741 if (instruction_pointer(regs) > TASK_SIZE)
742 arm64_apply_bp_hardening();
746 if (show_unhandled_signals && unhandled_signal(tsk, SIGBUS))
747 pr_info_ratelimited("%s[%d]: %s exception: pc=%p sp=%p\n",
748 tsk->comm, task_pid_nr(tsk),
749 esr_get_class_string(esr), (void *)regs->pc,
752 info.si_signo = SIGBUS;
754 info.si_code = BUS_ADRALN;
755 info.si_addr = (void __user *)addr;
756 arm64_notify_die("Oops - SP/PC alignment exception", regs, &info, esr);
759 int __init early_brk64(unsigned long addr, unsigned int esr,
760 struct pt_regs *regs);
763 * __refdata because early_brk64 is __init, but the reference to it is
764 * clobbered at arch_initcall time.
765 * See traps.c and debug-monitors.c:debug_traps_init().
767 static struct fault_info __refdata debug_fault_info[] = {
768 { do_bad, SIGTRAP, TRAP_HWBKPT, "hardware breakpoint" },
769 { do_bad, SIGTRAP, TRAP_HWBKPT, "hardware single-step" },
770 { do_bad, SIGTRAP, TRAP_HWBKPT, "hardware watchpoint" },
771 { do_bad, SIGBUS, BUS_FIXME, "unknown 3" },
772 { do_bad, SIGTRAP, TRAP_BRKPT, "aarch32 BKPT" },
773 { do_bad, SIGTRAP, TRAP_FIXME, "aarch32 vector catch" },
774 { early_brk64, SIGTRAP, TRAP_BRKPT, "aarch64 BRK" },
775 { do_bad, SIGBUS, BUS_FIXME, "unknown 7" },
778 void __init hook_debug_fault_code(int nr,
779 int (*fn)(unsigned long, unsigned int, struct pt_regs *),
780 int sig, int code, const char *name)
782 BUG_ON(nr < 0 || nr >= ARRAY_SIZE(debug_fault_info));
784 debug_fault_info[nr].fn = fn;
785 debug_fault_info[nr].sig = sig;
786 debug_fault_info[nr].code = code;
787 debug_fault_info[nr].name = name;
790 asmlinkage int __exception do_debug_exception(unsigned long addr,
792 struct pt_regs *regs)
794 const struct fault_info *inf = debug_fault_info + DBG_ESR_EVT(esr);
799 * Tell lockdep we disabled irqs in entry.S. Do nothing if they were
800 * already disabled to preserve the last enabled/disabled addresses.
802 if (interrupts_enabled(regs))
803 trace_hardirqs_off();
805 if (user_mode(regs) && instruction_pointer(regs) > TASK_SIZE)
806 arm64_apply_bp_hardening();
808 if (!inf->fn(addr, esr, regs)) {
811 pr_alert("Unhandled debug exception: %s (0x%08x) at 0x%016lx\n",
812 inf->name, esr, addr);
814 info.si_signo = inf->sig;
816 info.si_code = inf->code;
817 info.si_addr = (void __user *)addr;
818 arm64_notify_die("", regs, &info, 0);
822 if (interrupts_enabled(regs))
827 NOKPROBE_SYMBOL(do_debug_exception);
829 #ifdef CONFIG_ARM64_PAN
830 int cpu_enable_pan(void *__unused)
833 * We modify PSTATE. This won't work from irq context as the PSTATE
834 * is discarded once we return from the exception.
836 WARN_ON_ONCE(in_interrupt());
838 config_sctlr_el1(SCTLR_EL1_SPAN, 0);
839 asm(SET_PSTATE_PAN(1));
842 #endif /* CONFIG_ARM64_PAN */