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
< USER_DS
&& 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
< USER_DS
&& 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
;
579 inf
= esr_to_fault_info(esr
);
580 pr_err("Synchronous External Abort: %s (0x%08x) at 0x%016lx\n",
581 inf
->name
, esr
, addr
);
584 * Synchronous aborts may interrupt code which had interrupts masked.
585 * Before calling out into the wider kernel tell the interested
588 if (IS_ENABLED(CONFIG_ACPI_APEI_SEA
)) {
589 if (interrupts_enabled(regs
))
592 ret
= ghes_notify_sea();
594 if (interrupts_enabled(regs
))
598 info
.si_signo
= SIGBUS
;
601 if (esr
& ESR_ELx_FnV
)
604 info
.si_addr
= (void __user
*)addr
;
605 arm64_notify_die("", regs
, &info
, esr
);
610 static const struct fault_info fault_info
[] = {
611 { do_bad
, SIGBUS
, 0, "ttbr address size fault" },
612 { do_bad
, SIGBUS
, 0, "level 1 address size fault" },
613 { do_bad
, SIGBUS
, 0, "level 2 address size fault" },
614 { do_bad
, SIGBUS
, 0, "level 3 address size fault" },
615 { do_translation_fault
, SIGSEGV
, SEGV_MAPERR
, "level 0 translation fault" },
616 { do_translation_fault
, SIGSEGV
, SEGV_MAPERR
, "level 1 translation fault" },
617 { do_translation_fault
, SIGSEGV
, SEGV_MAPERR
, "level 2 translation fault" },
618 { do_translation_fault
, SIGSEGV
, SEGV_MAPERR
, "level 3 translation fault" },
619 { do_bad
, SIGBUS
, 0, "unknown 8" },
620 { do_page_fault
, SIGSEGV
, SEGV_ACCERR
, "level 1 access flag fault" },
621 { do_page_fault
, SIGSEGV
, SEGV_ACCERR
, "level 2 access flag fault" },
622 { do_page_fault
, SIGSEGV
, SEGV_ACCERR
, "level 3 access flag fault" },
623 { do_bad
, SIGBUS
, 0, "unknown 12" },
624 { do_page_fault
, SIGSEGV
, SEGV_ACCERR
, "level 1 permission fault" },
625 { do_page_fault
, SIGSEGV
, SEGV_ACCERR
, "level 2 permission fault" },
626 { do_page_fault
, SIGSEGV
, SEGV_ACCERR
, "level 3 permission fault" },
627 { do_sea
, SIGBUS
, 0, "synchronous external abort" },
628 { do_bad
, SIGBUS
, 0, "unknown 17" },
629 { do_bad
, SIGBUS
, 0, "unknown 18" },
630 { do_bad
, SIGBUS
, 0, "unknown 19" },
631 { do_sea
, SIGBUS
, 0, "level 0 (translation table walk)" },
632 { do_sea
, SIGBUS
, 0, "level 1 (translation table walk)" },
633 { do_sea
, SIGBUS
, 0, "level 2 (translation table walk)" },
634 { do_sea
, SIGBUS
, 0, "level 3 (translation table walk)" },
635 { do_sea
, SIGBUS
, 0, "synchronous parity or ECC error" }, // Reserved when RAS is implemented
636 { do_bad
, SIGBUS
, 0, "unknown 25" },
637 { do_bad
, SIGBUS
, 0, "unknown 26" },
638 { do_bad
, SIGBUS
, 0, "unknown 27" },
639 { do_sea
, SIGBUS
, 0, "level 0 synchronous parity error (translation table walk)" }, // Reserved when RAS is implemented
640 { do_sea
, SIGBUS
, 0, "level 1 synchronous parity error (translation table walk)" }, // Reserved when RAS is implemented
641 { do_sea
, SIGBUS
, 0, "level 2 synchronous parity error (translation table walk)" }, // Reserved when RAS is implemented
642 { do_sea
, SIGBUS
, 0, "level 3 synchronous parity error (translation table walk)" }, // Reserved when RAS is implemented
643 { do_bad
, SIGBUS
, 0, "unknown 32" },
644 { do_alignment_fault
, SIGBUS
, BUS_ADRALN
, "alignment fault" },
645 { do_bad
, SIGBUS
, 0, "unknown 34" },
646 { do_bad
, SIGBUS
, 0, "unknown 35" },
647 { do_bad
, SIGBUS
, 0, "unknown 36" },
648 { do_bad
, SIGBUS
, 0, "unknown 37" },
649 { do_bad
, SIGBUS
, 0, "unknown 38" },
650 { do_bad
, SIGBUS
, 0, "unknown 39" },
651 { do_bad
, SIGBUS
, 0, "unknown 40" },
652 { do_bad
, SIGBUS
, 0, "unknown 41" },
653 { do_bad
, SIGBUS
, 0, "unknown 42" },
654 { do_bad
, SIGBUS
, 0, "unknown 43" },
655 { do_bad
, SIGBUS
, 0, "unknown 44" },
656 { do_bad
, SIGBUS
, 0, "unknown 45" },
657 { do_bad
, SIGBUS
, 0, "unknown 46" },
658 { do_bad
, SIGBUS
, 0, "unknown 47" },
659 { do_bad
, SIGBUS
, 0, "TLB conflict abort" },
660 { do_bad
, SIGBUS
, 0, "Unsupported atomic hardware update fault" },
661 { do_bad
, SIGBUS
, 0, "unknown 50" },
662 { do_bad
, SIGBUS
, 0, "unknown 51" },
663 { do_bad
, SIGBUS
, 0, "implementation fault (lockdown abort)" },
664 { do_bad
, SIGBUS
, 0, "implementation fault (unsupported exclusive)" },
665 { do_bad
, SIGBUS
, 0, "unknown 54" },
666 { do_bad
, SIGBUS
, 0, "unknown 55" },
667 { do_bad
, SIGBUS
, 0, "unknown 56" },
668 { do_bad
, SIGBUS
, 0, "unknown 57" },
669 { do_bad
, SIGBUS
, 0, "unknown 58" },
670 { do_bad
, SIGBUS
, 0, "unknown 59" },
671 { do_bad
, SIGBUS
, 0, "unknown 60" },
672 { do_bad
, SIGBUS
, 0, "section domain fault" },
673 { do_bad
, SIGBUS
, 0, "page domain fault" },
674 { do_bad
, SIGBUS
, 0, "unknown 63" },
677 int handle_guest_sea(phys_addr_t addr
, unsigned int esr
)
681 if (IS_ENABLED(CONFIG_ACPI_APEI_SEA
))
682 ret
= ghes_notify_sea();
687 asmlinkage
void __exception
do_mem_abort(unsigned long addr
, unsigned int esr
,
688 struct pt_regs
*regs
)
690 const struct fault_info
*inf
= esr_to_fault_info(esr
);
693 if (!inf
->fn(addr
, esr
, regs
))
696 pr_alert("Unhandled fault: %s at 0x%016lx\n",
699 mem_abort_decode(esr
);
701 if (!user_mode(regs
))
704 info
.si_signo
= inf
->sig
;
706 info
.si_code
= inf
->code
;
707 info
.si_addr
= (void __user
*)addr
;
708 arm64_notify_die("", regs
, &info
, esr
);
711 asmlinkage
void __exception
do_sp_pc_abort(unsigned long addr
,
713 struct pt_regs
*regs
)
716 struct task_struct
*tsk
= current
;
718 if (show_unhandled_signals
&& unhandled_signal(tsk
, SIGBUS
))
719 pr_info_ratelimited("%s[%d]: %s exception: pc=%p sp=%p\n",
720 tsk
->comm
, task_pid_nr(tsk
),
721 esr_get_class_string(esr
), (void *)regs
->pc
,
724 info
.si_signo
= SIGBUS
;
726 info
.si_code
= BUS_ADRALN
;
727 info
.si_addr
= (void __user
*)addr
;
728 arm64_notify_die("Oops - SP/PC alignment exception", regs
, &info
, esr
);
731 int __init
early_brk64(unsigned long addr
, unsigned int esr
,
732 struct pt_regs
*regs
);
735 * __refdata because early_brk64 is __init, but the reference to it is
736 * clobbered at arch_initcall time.
737 * See traps.c and debug-monitors.c:debug_traps_init().
739 static struct fault_info __refdata debug_fault_info
[] = {
740 { do_bad
, SIGTRAP
, TRAP_HWBKPT
, "hardware breakpoint" },
741 { do_bad
, SIGTRAP
, TRAP_HWBKPT
, "hardware single-step" },
742 { do_bad
, SIGTRAP
, TRAP_HWBKPT
, "hardware watchpoint" },
743 { do_bad
, SIGBUS
, 0, "unknown 3" },
744 { do_bad
, SIGTRAP
, TRAP_BRKPT
, "aarch32 BKPT" },
745 { do_bad
, SIGTRAP
, 0, "aarch32 vector catch" },
746 { early_brk64
, SIGTRAP
, TRAP_BRKPT
, "aarch64 BRK" },
747 { do_bad
, SIGBUS
, 0, "unknown 7" },
750 void __init
hook_debug_fault_code(int nr
,
751 int (*fn
)(unsigned long, unsigned int, struct pt_regs
*),
752 int sig
, int code
, const char *name
)
754 BUG_ON(nr
< 0 || nr
>= ARRAY_SIZE(debug_fault_info
));
756 debug_fault_info
[nr
].fn
= fn
;
757 debug_fault_info
[nr
].sig
= sig
;
758 debug_fault_info
[nr
].code
= code
;
759 debug_fault_info
[nr
].name
= name
;
762 asmlinkage
int __exception
do_debug_exception(unsigned long addr
,
764 struct pt_regs
*regs
)
766 const struct fault_info
*inf
= debug_fault_info
+ DBG_ESR_EVT(esr
);
771 * Tell lockdep we disabled irqs in entry.S. Do nothing if they were
772 * already disabled to preserve the last enabled/disabled addresses.
774 if (interrupts_enabled(regs
))
775 trace_hardirqs_off();
777 if (!inf
->fn(addr
, esr
, regs
)) {
780 pr_alert("Unhandled debug exception: %s (0x%08x) at 0x%016lx\n",
781 inf
->name
, esr
, addr
);
783 info
.si_signo
= inf
->sig
;
785 info
.si_code
= inf
->code
;
786 info
.si_addr
= (void __user
*)addr
;
787 arm64_notify_die("", regs
, &info
, 0);
791 if (interrupts_enabled(regs
))
796 NOKPROBE_SYMBOL(do_debug_exception
);
798 #ifdef CONFIG_ARM64_PAN
799 int cpu_enable_pan(void *__unused
)
802 * We modify PSTATE. This won't work from irq context as the PSTATE
803 * is discarded once we return from the exception.
805 WARN_ON_ONCE(in_interrupt());
807 config_sctlr_el1(SCTLR_EL1_SPAN
, 0);
808 asm(SET_PSTATE_PAN(1));
811 #endif /* CONFIG_ARM64_PAN */