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%08lu\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
);
109 * Decode mem abort information
111 static void mem_abort_decode(unsigned int esr
)
113 pr_alert("Mem abort info:\n");
115 pr_alert(" Exception class = %s, IL = %u bits\n",
116 esr_get_class_string(esr
),
117 (esr
& ESR_ELx_IL
) ? 32 : 16);
118 pr_alert(" SET = %lu, FnV = %lu\n",
119 (esr
& ESR_ELx_SET_MASK
) >> ESR_ELx_SET_SHIFT
,
120 (esr
& ESR_ELx_FnV
) >> ESR_ELx_FnV_SHIFT
);
121 pr_alert(" EA = %lu, S1PTW = %lu\n",
122 (esr
& ESR_ELx_EA
) >> ESR_ELx_EA_SHIFT
,
123 (esr
& ESR_ELx_S1PTW
) >> ESR_ELx_S1PTW_SHIFT
);
125 if (esr_is_data_abort(esr
))
126 data_abort_decode(esr
);
130 * Dump out the page tables associated with 'addr' in the currently active mm.
132 void show_pte(unsigned long addr
)
134 struct mm_struct
*mm
;
137 if (addr
< TASK_SIZE
) {
139 mm
= current
->active_mm
;
140 if (mm
== &init_mm
) {
141 pr_alert("[%016lx] user address but active_mm is swapper\n",
145 } else if (addr
>= VA_START
) {
149 pr_alert("[%016lx] address between user and kernel address ranges\n",
154 pr_alert("%s pgtable: %luk pages, %u-bit VAs, pgd = %p\n",
155 mm
== &init_mm
? "swapper" : "user", PAGE_SIZE
/ SZ_1K
,
157 pgd
= pgd_offset(mm
, addr
);
158 pr_alert("[%016lx] *pgd=%016llx", addr
, pgd_val(*pgd
));
165 if (pgd_none(*pgd
) || pgd_bad(*pgd
))
168 pud
= pud_offset(pgd
, addr
);
169 pr_cont(", *pud=%016llx", pud_val(*pud
));
170 if (pud_none(*pud
) || pud_bad(*pud
))
173 pmd
= pmd_offset(pud
, addr
);
174 pr_cont(", *pmd=%016llx", pmd_val(*pmd
));
175 if (pmd_none(*pmd
) || pmd_bad(*pmd
))
178 pte
= pte_offset_map(pmd
, addr
);
179 pr_cont(", *pte=%016llx", pte_val(*pte
));
187 * This function sets the access flags (dirty, accessed), as well as write
188 * permission, and only to a more permissive setting.
190 * It needs to cope with hardware update of the accessed/dirty state by other
191 * agents in the system and can safely skip the __sync_icache_dcache() call as,
192 * like set_pte_at(), the PTE is never changed from no-exec to exec here.
194 * Returns whether or not the PTE actually changed.
196 int ptep_set_access_flags(struct vm_area_struct
*vma
,
197 unsigned long address
, pte_t
*ptep
,
198 pte_t entry
, int dirty
)
200 pteval_t old_pteval
, pteval
;
202 if (pte_same(*ptep
, entry
))
205 /* only preserve the access flags and write permission */
206 pte_val(entry
) &= PTE_RDONLY
| PTE_AF
| PTE_WRITE
| PTE_DIRTY
;
209 * Setting the flags must be done atomically to avoid racing with the
210 * hardware update of the access/dirty state. The PTE_RDONLY bit must
211 * be set to the most permissive (lowest value) of *ptep and entry
212 * (calculated as: a & b == ~(~a | ~b)).
214 pte_val(entry
) ^= PTE_RDONLY
;
215 pteval
= READ_ONCE(pte_val(*ptep
));
218 pteval
^= PTE_RDONLY
;
219 pteval
|= pte_val(entry
);
220 pteval
^= PTE_RDONLY
;
221 pteval
= cmpxchg_relaxed(&pte_val(*ptep
), old_pteval
, pteval
);
222 } while (pteval
!= old_pteval
);
224 flush_tlb_fix_spurious_fault(vma
, address
);
228 static bool is_el1_instruction_abort(unsigned int esr
)
230 return ESR_ELx_EC(esr
) == ESR_ELx_EC_IABT_CUR
;
233 static inline bool is_permission_fault(unsigned int esr
, struct pt_regs
*regs
,
236 unsigned int ec
= ESR_ELx_EC(esr
);
237 unsigned int fsc_type
= esr
& ESR_ELx_FSC_TYPE
;
239 if (ec
!= ESR_ELx_EC_DABT_CUR
&& ec
!= ESR_ELx_EC_IABT_CUR
)
242 if (fsc_type
== ESR_ELx_FSC_PERM
)
245 if (addr
< USER_DS
&& system_uses_ttbr0_pan())
246 return fsc_type
== ESR_ELx_FSC_FAULT
&&
247 (regs
->pstate
& PSR_PAN_BIT
);
253 * The kernel tried to access some page that wasn't present.
255 static void __do_kernel_fault(unsigned long addr
, unsigned int esr
,
256 struct pt_regs
*regs
)
261 * Are we prepared to handle this kernel fault?
262 * We are almost certainly not prepared to handle instruction faults.
264 if (!is_el1_instruction_abort(esr
) && fixup_exception(regs
))
268 * No handler, we'll have to terminate things with extreme prejudice.
272 if (is_permission_fault(esr
, regs
, addr
)) {
273 if (esr
& ESR_ELx_WNR
)
274 msg
= "write to read-only memory";
276 msg
= "read from unreadable memory";
277 } else if (addr
< PAGE_SIZE
) {
278 msg
= "NULL pointer dereference";
280 msg
= "paging request";
283 pr_alert("Unable to handle kernel %s at virtual address %08lx\n", msg
,
286 mem_abort_decode(esr
);
289 die("Oops", regs
, esr
);
295 * Something tried to access memory that isn't in our memory map. User mode
296 * accesses just cause a SIGSEGV
298 static void __do_user_fault(struct task_struct
*tsk
, unsigned long addr
,
299 unsigned int esr
, unsigned int sig
, int code
,
300 struct pt_regs
*regs
, int fault
)
303 const struct fault_info
*inf
;
304 unsigned int lsb
= 0;
306 if (unhandled_signal(tsk
, sig
) && show_unhandled_signals_ratelimited()) {
307 inf
= esr_to_fault_info(esr
);
308 pr_info("%s[%d]: unhandled %s (%d) at 0x%08lx, esr 0x%03x",
309 tsk
->comm
, task_pid_nr(tsk
), inf
->name
, sig
,
311 print_vma_addr(KERN_CONT
", in ", regs
->pc
);
316 tsk
->thread
.fault_address
= addr
;
317 tsk
->thread
.fault_code
= esr
;
321 si
.si_addr
= (void __user
*)addr
;
323 * Either small page or large page may be poisoned.
324 * In other words, VM_FAULT_HWPOISON_LARGE and
325 * VM_FAULT_HWPOISON are mutually exclusive.
327 if (fault
& VM_FAULT_HWPOISON_LARGE
)
328 lsb
= hstate_index_to_shift(VM_FAULT_GET_HINDEX(fault
));
329 else if (fault
& VM_FAULT_HWPOISON
)
331 si
.si_addr_lsb
= lsb
;
333 force_sig_info(sig
, &si
, tsk
);
336 static void do_bad_area(unsigned long addr
, unsigned int esr
, struct pt_regs
*regs
)
338 struct task_struct
*tsk
= current
;
339 const struct fault_info
*inf
;
342 * If we are in kernel mode at this point, we have no context to
343 * handle this fault with.
345 if (user_mode(regs
)) {
346 inf
= esr_to_fault_info(esr
);
347 __do_user_fault(tsk
, addr
, esr
, inf
->sig
, inf
->code
, regs
, 0);
349 __do_kernel_fault(addr
, esr
, regs
);
352 #define VM_FAULT_BADMAP 0x010000
353 #define VM_FAULT_BADACCESS 0x020000
355 static int __do_page_fault(struct mm_struct
*mm
, unsigned long addr
,
356 unsigned int mm_flags
, unsigned long vm_flags
,
357 struct task_struct
*tsk
)
359 struct vm_area_struct
*vma
;
362 vma
= find_vma(mm
, addr
);
363 fault
= VM_FAULT_BADMAP
;
366 if (unlikely(vma
->vm_start
> addr
))
370 * Ok, we have a good vm_area for this memory access, so we can handle
375 * Check that the permissions on the VMA allow for the fault which
378 if (!(vma
->vm_flags
& vm_flags
)) {
379 fault
= VM_FAULT_BADACCESS
;
383 return handle_mm_fault(vma
, addr
& PAGE_MASK
, mm_flags
);
386 if (vma
->vm_flags
& VM_GROWSDOWN
&& !expand_stack(vma
, addr
))
392 static bool is_el0_instruction_abort(unsigned int esr
)
394 return ESR_ELx_EC(esr
) == ESR_ELx_EC_IABT_LOW
;
397 static int __kprobes
do_page_fault(unsigned long addr
, unsigned int esr
,
398 struct pt_regs
*regs
)
400 struct task_struct
*tsk
;
401 struct mm_struct
*mm
;
402 int fault
, sig
, code
, major
= 0;
403 unsigned long vm_flags
= VM_READ
| VM_WRITE
;
404 unsigned int mm_flags
= FAULT_FLAG_ALLOW_RETRY
| FAULT_FLAG_KILLABLE
;
406 if (notify_page_fault(regs
, esr
))
413 * If we're in an interrupt or have no user context, we must not take
416 if (faulthandler_disabled() || !mm
)
420 mm_flags
|= FAULT_FLAG_USER
;
422 if (is_el0_instruction_abort(esr
)) {
424 } else if ((esr
& ESR_ELx_WNR
) && !(esr
& ESR_ELx_CM
)) {
426 mm_flags
|= FAULT_FLAG_WRITE
;
429 if (addr
< USER_DS
&& is_permission_fault(esr
, regs
, addr
)) {
430 /* regs->orig_addr_limit may be 0 if we entered from EL0 */
431 if (regs
->orig_addr_limit
== KERNEL_DS
)
432 die("Accessing user space memory with fs=KERNEL_DS", regs
, esr
);
434 if (is_el1_instruction_abort(esr
))
435 die("Attempting to execute userspace memory", regs
, esr
);
437 if (!search_exception_tables(regs
->pc
))
438 die("Accessing user space memory outside uaccess.h routines", regs
, esr
);
441 perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS
, 1, regs
, addr
);
444 * As per x86, we may deadlock here. However, since the kernel only
445 * validly references user space from well defined areas of the code,
446 * we can bug out early if this is from code which shouldn't.
448 if (!down_read_trylock(&mm
->mmap_sem
)) {
449 if (!user_mode(regs
) && !search_exception_tables(regs
->pc
))
452 down_read(&mm
->mmap_sem
);
455 * The above down_read_trylock() might have succeeded in which
456 * case, we'll have missed the might_sleep() from down_read().
459 #ifdef CONFIG_DEBUG_VM
460 if (!user_mode(regs
) && !search_exception_tables(regs
->pc
))
465 fault
= __do_page_fault(mm
, addr
, mm_flags
, vm_flags
, tsk
);
466 major
|= fault
& VM_FAULT_MAJOR
;
468 if (fault
& VM_FAULT_RETRY
) {
470 * If we need to retry but a fatal signal is pending,
471 * handle the signal first. We do not need to release
472 * the mmap_sem because it would already be released
473 * in __lock_page_or_retry in mm/filemap.c.
475 if (fatal_signal_pending(current
)) {
476 if (!user_mode(regs
))
482 * Clear FAULT_FLAG_ALLOW_RETRY to avoid any risk of
485 if (mm_flags
& FAULT_FLAG_ALLOW_RETRY
) {
486 mm_flags
&= ~FAULT_FLAG_ALLOW_RETRY
;
487 mm_flags
|= FAULT_FLAG_TRIED
;
491 up_read(&mm
->mmap_sem
);
494 * Handle the "normal" (no error) case first.
496 if (likely(!(fault
& (VM_FAULT_ERROR
| VM_FAULT_BADMAP
|
497 VM_FAULT_BADACCESS
)))) {
499 * Major/minor page fault accounting is only done
500 * once. If we go through a retry, it is extremely
501 * likely that the page will be found in page cache at
506 perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ
, 1, regs
,
510 perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN
, 1, regs
,
518 * If we are in kernel mode at this point, we have no context to
519 * handle this fault with.
521 if (!user_mode(regs
))
524 if (fault
& VM_FAULT_OOM
) {
526 * We ran out of memory, call the OOM killer, and return to
527 * userspace (which will retry the fault, or kill us if we got
530 pagefault_out_of_memory();
534 if (fault
& VM_FAULT_SIGBUS
) {
536 * We had some memory, but were unable to successfully fix up
541 } else if (fault
& (VM_FAULT_HWPOISON
| VM_FAULT_HWPOISON_LARGE
)) {
543 code
= BUS_MCEERR_AR
;
546 * Something tried to access memory that isn't in our memory
550 code
= fault
== VM_FAULT_BADACCESS
?
551 SEGV_ACCERR
: SEGV_MAPERR
;
554 __do_user_fault(tsk
, addr
, esr
, sig
, code
, regs
, fault
);
558 __do_kernel_fault(addr
, esr
, regs
);
563 * First Level Translation Fault Handler
565 * We enter here because the first level page table doesn't contain a valid
566 * entry for the address.
568 * If the address is in kernel space (>= TASK_SIZE), then we are probably
569 * faulting in the vmalloc() area.
571 * If the init_task's first level page tables contains the relevant entry, we
572 * copy the it to this task. If not, we send the process a signal, fixup the
573 * exception, or oops the kernel.
575 * NOTE! We MUST NOT take any locks for this case. We may be in an interrupt
576 * or a critical region, and should only copy the information from the master
577 * page table, nothing more.
579 static int __kprobes
do_translation_fault(unsigned long addr
,
581 struct pt_regs
*regs
)
583 if (addr
< TASK_SIZE
)
584 return do_page_fault(addr
, esr
, regs
);
586 do_bad_area(addr
, esr
, regs
);
590 static int do_alignment_fault(unsigned long addr
, unsigned int esr
,
591 struct pt_regs
*regs
)
593 do_bad_area(addr
, esr
, regs
);
598 * This abort handler always returns "fault".
600 static int do_bad(unsigned long addr
, unsigned int esr
, struct pt_regs
*regs
)
606 * This abort handler deals with Synchronous External Abort.
607 * It calls notifiers, and then returns "fault".
609 static int do_sea(unsigned long addr
, unsigned int esr
, struct pt_regs
*regs
)
612 const struct fault_info
*inf
;
615 inf
= esr_to_fault_info(esr
);
616 pr_err("Synchronous External Abort: %s (0x%08x) at 0x%016lx\n",
617 inf
->name
, esr
, addr
);
620 * Synchronous aborts may interrupt code which had interrupts masked.
621 * Before calling out into the wider kernel tell the interested
624 if (IS_ENABLED(CONFIG_ACPI_APEI_SEA
)) {
625 if (interrupts_enabled(regs
))
628 ret
= ghes_notify_sea();
630 if (interrupts_enabled(regs
))
634 info
.si_signo
= SIGBUS
;
637 if (esr
& ESR_ELx_FnV
)
640 info
.si_addr
= (void __user
*)addr
;
641 arm64_notify_die("", regs
, &info
, esr
);
646 static const struct fault_info fault_info
[] = {
647 { do_bad
, SIGBUS
, 0, "ttbr address size fault" },
648 { do_bad
, SIGBUS
, 0, "level 1 address size fault" },
649 { do_bad
, SIGBUS
, 0, "level 2 address size fault" },
650 { do_bad
, SIGBUS
, 0, "level 3 address size fault" },
651 { do_translation_fault
, SIGSEGV
, SEGV_MAPERR
, "level 0 translation fault" },
652 { do_translation_fault
, SIGSEGV
, SEGV_MAPERR
, "level 1 translation fault" },
653 { do_translation_fault
, SIGSEGV
, SEGV_MAPERR
, "level 2 translation fault" },
654 { do_page_fault
, SIGSEGV
, SEGV_MAPERR
, "level 3 translation fault" },
655 { do_bad
, SIGBUS
, 0, "unknown 8" },
656 { do_page_fault
, SIGSEGV
, SEGV_ACCERR
, "level 1 access flag fault" },
657 { do_page_fault
, SIGSEGV
, SEGV_ACCERR
, "level 2 access flag fault" },
658 { do_page_fault
, SIGSEGV
, SEGV_ACCERR
, "level 3 access flag fault" },
659 { do_bad
, SIGBUS
, 0, "unknown 12" },
660 { do_page_fault
, SIGSEGV
, SEGV_ACCERR
, "level 1 permission fault" },
661 { do_page_fault
, SIGSEGV
, SEGV_ACCERR
, "level 2 permission fault" },
662 { do_page_fault
, SIGSEGV
, SEGV_ACCERR
, "level 3 permission fault" },
663 { do_sea
, SIGBUS
, 0, "synchronous external abort" },
664 { do_bad
, SIGBUS
, 0, "unknown 17" },
665 { do_bad
, SIGBUS
, 0, "unknown 18" },
666 { do_bad
, SIGBUS
, 0, "unknown 19" },
667 { do_sea
, SIGBUS
, 0, "level 0 (translation table walk)" },
668 { do_sea
, SIGBUS
, 0, "level 1 (translation table walk)" },
669 { do_sea
, SIGBUS
, 0, "level 2 (translation table walk)" },
670 { do_sea
, SIGBUS
, 0, "level 3 (translation table walk)" },
671 { do_sea
, SIGBUS
, 0, "synchronous parity or ECC error" },
672 { do_bad
, SIGBUS
, 0, "unknown 25" },
673 { do_bad
, SIGBUS
, 0, "unknown 26" },
674 { do_bad
, SIGBUS
, 0, "unknown 27" },
675 { do_sea
, SIGBUS
, 0, "level 0 synchronous parity error (translation table walk)" },
676 { do_sea
, SIGBUS
, 0, "level 1 synchronous parity error (translation table walk)" },
677 { do_sea
, SIGBUS
, 0, "level 2 synchronous parity error (translation table walk)" },
678 { do_sea
, SIGBUS
, 0, "level 3 synchronous parity error (translation table walk)" },
679 { do_bad
, SIGBUS
, 0, "unknown 32" },
680 { do_alignment_fault
, SIGBUS
, BUS_ADRALN
, "alignment fault" },
681 { do_bad
, SIGBUS
, 0, "unknown 34" },
682 { do_bad
, SIGBUS
, 0, "unknown 35" },
683 { do_bad
, SIGBUS
, 0, "unknown 36" },
684 { do_bad
, SIGBUS
, 0, "unknown 37" },
685 { do_bad
, SIGBUS
, 0, "unknown 38" },
686 { do_bad
, SIGBUS
, 0, "unknown 39" },
687 { do_bad
, SIGBUS
, 0, "unknown 40" },
688 { do_bad
, SIGBUS
, 0, "unknown 41" },
689 { do_bad
, SIGBUS
, 0, "unknown 42" },
690 { do_bad
, SIGBUS
, 0, "unknown 43" },
691 { do_bad
, SIGBUS
, 0, "unknown 44" },
692 { do_bad
, SIGBUS
, 0, "unknown 45" },
693 { do_bad
, SIGBUS
, 0, "unknown 46" },
694 { do_bad
, SIGBUS
, 0, "unknown 47" },
695 { do_bad
, SIGBUS
, 0, "TLB conflict abort" },
696 { do_bad
, SIGBUS
, 0, "unknown 49" },
697 { do_bad
, SIGBUS
, 0, "unknown 50" },
698 { do_bad
, SIGBUS
, 0, "unknown 51" },
699 { do_bad
, SIGBUS
, 0, "implementation fault (lockdown abort)" },
700 { do_bad
, SIGBUS
, 0, "implementation fault (unsupported exclusive)" },
701 { do_bad
, SIGBUS
, 0, "unknown 54" },
702 { do_bad
, SIGBUS
, 0, "unknown 55" },
703 { do_bad
, SIGBUS
, 0, "unknown 56" },
704 { do_bad
, SIGBUS
, 0, "unknown 57" },
705 { do_bad
, SIGBUS
, 0, "unknown 58" },
706 { do_bad
, SIGBUS
, 0, "unknown 59" },
707 { do_bad
, SIGBUS
, 0, "unknown 60" },
708 { do_bad
, SIGBUS
, 0, "section domain fault" },
709 { do_bad
, SIGBUS
, 0, "page domain fault" },
710 { do_bad
, SIGBUS
, 0, "unknown 63" },
714 * Handle Synchronous External Aborts that occur in a guest kernel.
716 * The return value will be zero if the SEA was successfully handled
717 * and non-zero if there was an error processing the error or there was
718 * no error to process.
720 int handle_guest_sea(phys_addr_t addr
, unsigned int esr
)
724 if (IS_ENABLED(CONFIG_ACPI_APEI_SEA
))
725 ret
= ghes_notify_sea();
731 * Dispatch a data abort to the relevant handler.
733 asmlinkage
void __exception
do_mem_abort(unsigned long addr
, unsigned int esr
,
734 struct pt_regs
*regs
)
736 const struct fault_info
*inf
= esr_to_fault_info(esr
);
739 if (!inf
->fn(addr
, esr
, regs
))
742 pr_alert("Unhandled fault: %s (0x%08x) at 0x%016lx\n",
743 inf
->name
, esr
, addr
);
745 mem_abort_decode(esr
);
747 info
.si_signo
= inf
->sig
;
749 info
.si_code
= inf
->code
;
750 info
.si_addr
= (void __user
*)addr
;
751 arm64_notify_die("", regs
, &info
, esr
);
755 * Handle stack alignment exceptions.
757 asmlinkage
void __exception
do_sp_pc_abort(unsigned long addr
,
759 struct pt_regs
*regs
)
762 struct task_struct
*tsk
= current
;
764 if (show_unhandled_signals
&& unhandled_signal(tsk
, SIGBUS
))
765 pr_info_ratelimited("%s[%d]: %s exception: pc=%p sp=%p\n",
766 tsk
->comm
, task_pid_nr(tsk
),
767 esr_get_class_string(esr
), (void *)regs
->pc
,
770 info
.si_signo
= SIGBUS
;
772 info
.si_code
= BUS_ADRALN
;
773 info
.si_addr
= (void __user
*)addr
;
774 arm64_notify_die("Oops - SP/PC alignment exception", regs
, &info
, esr
);
777 int __init
early_brk64(unsigned long addr
, unsigned int esr
,
778 struct pt_regs
*regs
);
781 * __refdata because early_brk64 is __init, but the reference to it is
782 * clobbered at arch_initcall time.
783 * See traps.c and debug-monitors.c:debug_traps_init().
785 static struct fault_info __refdata debug_fault_info
[] = {
786 { do_bad
, SIGTRAP
, TRAP_HWBKPT
, "hardware breakpoint" },
787 { do_bad
, SIGTRAP
, TRAP_HWBKPT
, "hardware single-step" },
788 { do_bad
, SIGTRAP
, TRAP_HWBKPT
, "hardware watchpoint" },
789 { do_bad
, SIGBUS
, 0, "unknown 3" },
790 { do_bad
, SIGTRAP
, TRAP_BRKPT
, "aarch32 BKPT" },
791 { do_bad
, SIGTRAP
, 0, "aarch32 vector catch" },
792 { early_brk64
, SIGTRAP
, TRAP_BRKPT
, "aarch64 BRK" },
793 { do_bad
, SIGBUS
, 0, "unknown 7" },
796 void __init
hook_debug_fault_code(int nr
,
797 int (*fn
)(unsigned long, unsigned int, struct pt_regs
*),
798 int sig
, int code
, const char *name
)
800 BUG_ON(nr
< 0 || nr
>= ARRAY_SIZE(debug_fault_info
));
802 debug_fault_info
[nr
].fn
= fn
;
803 debug_fault_info
[nr
].sig
= sig
;
804 debug_fault_info
[nr
].code
= code
;
805 debug_fault_info
[nr
].name
= name
;
808 asmlinkage
int __exception
do_debug_exception(unsigned long addr
,
810 struct pt_regs
*regs
)
812 const struct fault_info
*inf
= debug_fault_info
+ DBG_ESR_EVT(esr
);
817 * Tell lockdep we disabled irqs in entry.S. Do nothing if they were
818 * already disabled to preserve the last enabled/disabled addresses.
820 if (interrupts_enabled(regs
))
821 trace_hardirqs_off();
823 if (!inf
->fn(addr
, esr
, regs
)) {
826 pr_alert("Unhandled debug exception: %s (0x%08x) at 0x%016lx\n",
827 inf
->name
, esr
, addr
);
829 info
.si_signo
= inf
->sig
;
831 info
.si_code
= inf
->code
;
832 info
.si_addr
= (void __user
*)addr
;
833 arm64_notify_die("", regs
, &info
, 0);
837 if (interrupts_enabled(regs
))
842 NOKPROBE_SYMBOL(do_debug_exception
);
844 #ifdef CONFIG_ARM64_PAN
845 int cpu_enable_pan(void *__unused
)
848 * We modify PSTATE. This won't work from irq context as the PSTATE
849 * is discarded once we return from the exception.
851 WARN_ON_ONCE(in_interrupt());
853 config_sctlr_el1(SCTLR_EL1_SPAN
, 0);
854 asm(SET_PSTATE_PAN(1));
857 #endif /* CONFIG_ARM64_PAN */