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10#include <linux/acpi.h>
11#include <linux/bitfield.h>
12#include <linux/extable.h>
13#include <linux/kfence.h>
14#include <linux/signal.h>
15#include <linux/mm.h>
16#include <linux/hardirq.h>
17#include <linux/init.h>
18#include <linux/kasan.h>
19#include <linux/kprobes.h>
20#include <linux/uaccess.h>
21#include <linux/page-flags.h>
22#include <linux/sched/signal.h>
23#include <linux/sched/debug.h>
24#include <linux/highmem.h>
25#include <linux/perf_event.h>
26#include <linux/preempt.h>
27#include <linux/hugetlb.h>
28
29#include <asm/acpi.h>
30#include <asm/bug.h>
31#include <asm/cmpxchg.h>
32#include <asm/cpufeature.h>
33#include <asm/exception.h>
34#include <asm/daifflags.h>
35#include <asm/debug-monitors.h>
36#include <asm/esr.h>
37#include <asm/kprobes.h>
38#include <asm/mte.h>
39#include <asm/processor.h>
40#include <asm/sysreg.h>
41#include <asm/system_misc.h>
42#include <asm/tlbflush.h>
43#include <asm/traps.h>
44
45struct fault_info {
46 int (*fn)(unsigned long far, unsigned int esr,
47 struct pt_regs *regs);
48 int sig;
49 int code;
50 const char *name;
51};
52
53static const struct fault_info fault_info[];
54static struct fault_info debug_fault_info[];
55
56static inline const struct fault_info *esr_to_fault_info(unsigned int esr)
57{
58 return fault_info + (esr & ESR_ELx_FSC);
59}
60
61static inline const struct fault_info *esr_to_debug_fault_info(unsigned int esr)
62{
63 return debug_fault_info + DBG_ESR_EVT(esr);
64}
65
66static void data_abort_decode(unsigned int esr)
67{
68 pr_alert("Data abort info:\n");
69
70 if (esr & ESR_ELx_ISV) {
71 pr_alert(" Access size = %u byte(s)\n",
72 1U << ((esr & ESR_ELx_SAS) >> ESR_ELx_SAS_SHIFT));
73 pr_alert(" SSE = %lu, SRT = %lu\n",
74 (esr & ESR_ELx_SSE) >> ESR_ELx_SSE_SHIFT,
75 (esr & ESR_ELx_SRT_MASK) >> ESR_ELx_SRT_SHIFT);
76 pr_alert(" SF = %lu, AR = %lu\n",
77 (esr & ESR_ELx_SF) >> ESR_ELx_SF_SHIFT,
78 (esr & ESR_ELx_AR) >> ESR_ELx_AR_SHIFT);
79 } else {
80 pr_alert(" ISV = 0, ISS = 0x%08lx\n", esr & ESR_ELx_ISS_MASK);
81 }
82
83 pr_alert(" CM = %lu, WnR = %lu\n",
84 (esr & ESR_ELx_CM) >> ESR_ELx_CM_SHIFT,
85 (esr & ESR_ELx_WNR) >> ESR_ELx_WNR_SHIFT);
86}
87
88static void mem_abort_decode(unsigned int esr)
89{
90 pr_alert("Mem abort info:\n");
91
92 pr_alert(" ESR = 0x%08x\n", esr);
93 pr_alert(" EC = 0x%02lx: %s, IL = %u bits\n",
94 ESR_ELx_EC(esr), esr_get_class_string(esr),
95 (esr & ESR_ELx_IL) ? 32 : 16);
96 pr_alert(" SET = %lu, FnV = %lu\n",
97 (esr & ESR_ELx_SET_MASK) >> ESR_ELx_SET_SHIFT,
98 (esr & ESR_ELx_FnV) >> ESR_ELx_FnV_SHIFT);
99 pr_alert(" EA = %lu, S1PTW = %lu\n",
100 (esr & ESR_ELx_EA) >> ESR_ELx_EA_SHIFT,
101 (esr & ESR_ELx_S1PTW) >> ESR_ELx_S1PTW_SHIFT);
102 pr_alert(" FSC = 0x%02x: %s\n", (esr & ESR_ELx_FSC),
103 esr_to_fault_info(esr)->name);
104
105 if (esr_is_data_abort(esr))
106 data_abort_decode(esr);
107}
108
109static inline unsigned long mm_to_pgd_phys(struct mm_struct *mm)
110{
111
112 if (mm == &init_mm)
113 return __pa_symbol(mm->pgd);
114
115 return (unsigned long)virt_to_phys(mm->pgd);
116}
117
118
119
120
121static void show_pte(unsigned long addr)
122{
123 struct mm_struct *mm;
124 pgd_t *pgdp;
125 pgd_t pgd;
126
127 if (is_ttbr0_addr(addr)) {
128
129 mm = current->active_mm;
130 if (mm == &init_mm) {
131 pr_alert("[%016lx] user address but active_mm is swapper\n",
132 addr);
133 return;
134 }
135 } else if (is_ttbr1_addr(addr)) {
136
137 mm = &init_mm;
138 } else {
139 pr_alert("[%016lx] address between user and kernel address ranges\n",
140 addr);
141 return;
142 }
143
144 pr_alert("%s pgtable: %luk pages, %llu-bit VAs, pgdp=%016lx\n",
145 mm == &init_mm ? "swapper" : "user", PAGE_SIZE / SZ_1K,
146 vabits_actual, mm_to_pgd_phys(mm));
147 pgdp = pgd_offset(mm, addr);
148 pgd = READ_ONCE(*pgdp);
149 pr_alert("[%016lx] pgd=%016llx", addr, pgd_val(pgd));
150
151 do {
152 p4d_t *p4dp, p4d;
153 pud_t *pudp, pud;
154 pmd_t *pmdp, pmd;
155 pte_t *ptep, pte;
156
157 if (pgd_none(pgd) || pgd_bad(pgd))
158 break;
159
160 p4dp = p4d_offset(pgdp, addr);
161 p4d = READ_ONCE(*p4dp);
162 pr_cont(", p4d=%016llx", p4d_val(p4d));
163 if (p4d_none(p4d) || p4d_bad(p4d))
164 break;
165
166 pudp = pud_offset(p4dp, addr);
167 pud = READ_ONCE(*pudp);
168 pr_cont(", pud=%016llx", pud_val(pud));
169 if (pud_none(pud) || pud_bad(pud))
170 break;
171
172 pmdp = pmd_offset(pudp, addr);
173 pmd = READ_ONCE(*pmdp);
174 pr_cont(", pmd=%016llx", pmd_val(pmd));
175 if (pmd_none(pmd) || pmd_bad(pmd))
176 break;
177
178 ptep = pte_offset_map(pmdp, addr);
179 pte = READ_ONCE(*ptep);
180 pr_cont(", pte=%016llx", pte_val(pte));
181 pte_unmap(ptep);
182 } while(0);
183
184 pr_cont("\n");
185}
186
187
188
189
190
191
192
193
194
195
196
197int ptep_set_access_flags(struct vm_area_struct *vma,
198 unsigned long address, pte_t *ptep,
199 pte_t entry, int dirty)
200{
201 pteval_t old_pteval, pteval;
202 pte_t pte = READ_ONCE(*ptep);
203
204 if (pte_same(pte, entry))
205 return 0;
206
207
208 pte_val(entry) &= PTE_RDONLY | PTE_AF | PTE_WRITE | PTE_DIRTY;
209
210
211
212
213
214
215
216 pte_val(entry) ^= PTE_RDONLY;
217 pteval = pte_val(pte);
218 do {
219 old_pteval = pteval;
220 pteval ^= PTE_RDONLY;
221 pteval |= pte_val(entry);
222 pteval ^= PTE_RDONLY;
223 pteval = cmpxchg_relaxed(&pte_val(*ptep), old_pteval, pteval);
224 } while (pteval != old_pteval);
225
226
227 if (dirty)
228 flush_tlb_page(vma, address);
229 return 1;
230}
231
232static bool is_el1_instruction_abort(unsigned int esr)
233{
234 return ESR_ELx_EC(esr) == ESR_ELx_EC_IABT_CUR;
235}
236
237static bool is_el1_data_abort(unsigned int esr)
238{
239 return ESR_ELx_EC(esr) == ESR_ELx_EC_DABT_CUR;
240}
241
242static inline bool is_el1_permission_fault(unsigned long addr, unsigned int esr,
243 struct pt_regs *regs)
244{
245 unsigned int fsc_type = esr & ESR_ELx_FSC_TYPE;
246
247 if (!is_el1_data_abort(esr) && !is_el1_instruction_abort(esr))
248 return false;
249
250 if (fsc_type == ESR_ELx_FSC_PERM)
251 return true;
252
253 if (is_ttbr0_addr(addr) && system_uses_ttbr0_pan())
254 return fsc_type == ESR_ELx_FSC_FAULT &&
255 (regs->pstate & PSR_PAN_BIT);
256
257 return false;
258}
259
260static bool __kprobes is_spurious_el1_translation_fault(unsigned long addr,
261 unsigned int esr,
262 struct pt_regs *regs)
263{
264 unsigned long flags;
265 u64 par, dfsc;
266
267 if (!is_el1_data_abort(esr) ||
268 (esr & ESR_ELx_FSC_TYPE) != ESR_ELx_FSC_FAULT)
269 return false;
270
271 local_irq_save(flags);
272 asm volatile("at s1e1r, %0" :: "r" (addr));
273 isb();
274 par = read_sysreg_par();
275 local_irq_restore(flags);
276
277
278
279
280
281 if (!(par & SYS_PAR_EL1_F))
282 return true;
283
284
285
286
287
288 dfsc = FIELD_GET(SYS_PAR_EL1_FST, par);
289 return (dfsc & ESR_ELx_FSC_TYPE) != ESR_ELx_FSC_FAULT;
290}
291
292static void die_kernel_fault(const char *msg, unsigned long addr,
293 unsigned int esr, struct pt_regs *regs)
294{
295 bust_spinlocks(1);
296
297 pr_alert("Unable to handle kernel %s at virtual address %016lx\n", msg,
298 addr);
299
300 mem_abort_decode(esr);
301
302 show_pte(addr);
303 die("Oops", regs, esr);
304 bust_spinlocks(0);
305 do_exit(SIGKILL);
306}
307
308#ifdef CONFIG_KASAN_HW_TAGS
309static void report_tag_fault(unsigned long addr, unsigned int esr,
310 struct pt_regs *regs)
311{
312
313
314
315
316 bool is_write = !!(esr & ESR_ELx_WNR);
317 kasan_report(addr, 0, is_write, regs->pc);
318}
319#else
320
321static inline void report_tag_fault(unsigned long addr, unsigned int esr,
322 struct pt_regs *regs) { }
323#endif
324
325static void do_tag_recovery(unsigned long addr, unsigned int esr,
326 struct pt_regs *regs)
327{
328
329 report_tag_fault(addr, esr, regs);
330
331
332
333
334
335
336 sysreg_clear_set(sctlr_el1, SCTLR_ELx_TCF_MASK, SCTLR_ELx_TCF_NONE);
337 isb();
338}
339
340static bool is_el1_mte_sync_tag_check_fault(unsigned int esr)
341{
342 unsigned int fsc = esr & ESR_ELx_FSC;
343
344 if (!is_el1_data_abort(esr))
345 return false;
346
347 if (fsc == ESR_ELx_FSC_MTE)
348 return true;
349
350 return false;
351}
352
353static void __do_kernel_fault(unsigned long addr, unsigned int esr,
354 struct pt_regs *regs)
355{
356 const char *msg;
357
358
359
360
361
362 if (!is_el1_instruction_abort(esr) && fixup_exception(regs))
363 return;
364
365 if (WARN_RATELIMIT(is_spurious_el1_translation_fault(addr, esr, regs),
366 "Ignoring spurious kernel translation fault at virtual address %016lx\n", addr))
367 return;
368
369 if (is_el1_mte_sync_tag_check_fault(esr)) {
370 do_tag_recovery(addr, esr, regs);
371
372 return;
373 }
374
375 if (is_el1_permission_fault(addr, esr, regs)) {
376 if (esr & ESR_ELx_WNR)
377 msg = "write to read-only memory";
378 else if (is_el1_instruction_abort(esr))
379 msg = "execute from non-executable memory";
380 else
381 msg = "read from unreadable memory";
382 } else if (addr < PAGE_SIZE) {
383 msg = "NULL pointer dereference";
384 } else {
385 if (kfence_handle_page_fault(addr, esr & ESR_ELx_WNR, regs))
386 return;
387
388 msg = "paging request";
389 }
390
391 die_kernel_fault(msg, addr, esr, regs);
392}
393
394static void set_thread_esr(unsigned long address, unsigned int esr)
395{
396 current->thread.fault_address = address;
397
398
399
400
401
402
403
404
405
406
407
408
409
410 if (!is_ttbr0_addr(current->thread.fault_address)) {
411 switch (ESR_ELx_EC(esr)) {
412 case ESR_ELx_EC_DABT_LOW:
413
414
415
416
417
418
419
420
421
422 esr &= ESR_ELx_EC_MASK | ESR_ELx_IL |
423 ESR_ELx_CM | ESR_ELx_WNR;
424 esr |= ESR_ELx_FSC_FAULT;
425 break;
426 case ESR_ELx_EC_IABT_LOW:
427
428
429
430
431
432 esr &= ESR_ELx_EC_MASK | ESR_ELx_IL;
433 esr |= ESR_ELx_FSC_FAULT;
434 break;
435 default:
436
437
438
439
440
441
442 WARN(1, "ESR 0x%x is not DABT or IABT from EL0\n", esr);
443 esr = 0;
444 break;
445 }
446 }
447
448 current->thread.fault_code = esr;
449}
450
451static void do_bad_area(unsigned long far, unsigned int esr,
452 struct pt_regs *regs)
453{
454 unsigned long addr = untagged_addr(far);
455
456
457
458
459
460 if (user_mode(regs)) {
461 const struct fault_info *inf = esr_to_fault_info(esr);
462
463 set_thread_esr(addr, esr);
464 arm64_force_sig_fault(inf->sig, inf->code, far, inf->name);
465 } else {
466 __do_kernel_fault(addr, esr, regs);
467 }
468}
469
470#define VM_FAULT_BADMAP 0x010000
471#define VM_FAULT_BADACCESS 0x020000
472
473static vm_fault_t __do_page_fault(struct mm_struct *mm, unsigned long addr,
474 unsigned int mm_flags, unsigned long vm_flags,
475 struct pt_regs *regs)
476{
477 struct vm_area_struct *vma = find_vma(mm, addr);
478
479 if (unlikely(!vma))
480 return VM_FAULT_BADMAP;
481
482
483
484
485
486 if (unlikely(vma->vm_start > addr)) {
487 if (!(vma->vm_flags & VM_GROWSDOWN))
488 return VM_FAULT_BADMAP;
489 if (expand_stack(vma, addr))
490 return VM_FAULT_BADMAP;
491 }
492
493
494
495
496
497 if (!(vma->vm_flags & vm_flags))
498 return VM_FAULT_BADACCESS;
499 return handle_mm_fault(vma, addr, mm_flags, regs);
500}
501
502static bool is_el0_instruction_abort(unsigned int esr)
503{
504 return ESR_ELx_EC(esr) == ESR_ELx_EC_IABT_LOW;
505}
506
507
508
509
510
511static bool is_write_abort(unsigned int esr)
512{
513 return (esr & ESR_ELx_WNR) && !(esr & ESR_ELx_CM);
514}
515
516static int __kprobes do_page_fault(unsigned long far, unsigned int esr,
517 struct pt_regs *regs)
518{
519 const struct fault_info *inf;
520 struct mm_struct *mm = current->mm;
521 vm_fault_t fault;
522 unsigned long vm_flags;
523 unsigned int mm_flags = FAULT_FLAG_DEFAULT;
524 unsigned long addr = untagged_addr(far);
525
526 if (kprobe_page_fault(regs, esr))
527 return 0;
528
529
530
531
532
533 if (faulthandler_disabled() || !mm)
534 goto no_context;
535
536 if (user_mode(regs))
537 mm_flags |= FAULT_FLAG_USER;
538
539
540
541
542
543
544
545 if (is_el0_instruction_abort(esr)) {
546
547 vm_flags = VM_EXEC;
548 mm_flags |= FAULT_FLAG_INSTRUCTION;
549 } else if (is_write_abort(esr)) {
550
551 vm_flags = VM_WRITE;
552 mm_flags |= FAULT_FLAG_WRITE;
553 } else {
554
555 vm_flags = VM_READ;
556
557 vm_flags |= VM_WRITE;
558
559 if (!cpus_have_const_cap(ARM64_HAS_EPAN))
560 vm_flags |= VM_EXEC;
561 }
562
563 if (is_ttbr0_addr(addr) && is_el1_permission_fault(addr, esr, regs)) {
564 if (is_el1_instruction_abort(esr))
565 die_kernel_fault("execution of user memory",
566 addr, esr, regs);
567
568 if (!search_exception_tables(regs->pc))
569 die_kernel_fault("access to user memory outside uaccess routines",
570 addr, esr, regs);
571 }
572
573 perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, addr);
574
575
576
577
578
579
580 if (!mmap_read_trylock(mm)) {
581 if (!user_mode(regs) && !search_exception_tables(regs->pc))
582 goto no_context;
583retry:
584 mmap_read_lock(mm);
585 } else {
586
587
588
589
590 might_sleep();
591#ifdef CONFIG_DEBUG_VM
592 if (!user_mode(regs) && !search_exception_tables(regs->pc)) {
593 mmap_read_unlock(mm);
594 goto no_context;
595 }
596#endif
597 }
598
599 fault = __do_page_fault(mm, addr, mm_flags, vm_flags, regs);
600
601
602 if (fault_signal_pending(fault, regs)) {
603 if (!user_mode(regs))
604 goto no_context;
605 return 0;
606 }
607
608 if (fault & VM_FAULT_RETRY) {
609 if (mm_flags & FAULT_FLAG_ALLOW_RETRY) {
610 mm_flags |= FAULT_FLAG_TRIED;
611 goto retry;
612 }
613 }
614 mmap_read_unlock(mm);
615
616
617
618
619 if (likely(!(fault & (VM_FAULT_ERROR | VM_FAULT_BADMAP |
620 VM_FAULT_BADACCESS))))
621 return 0;
622
623
624
625
626
627 if (!user_mode(regs))
628 goto no_context;
629
630 if (fault & VM_FAULT_OOM) {
631
632
633
634
635
636 pagefault_out_of_memory();
637 return 0;
638 }
639
640 inf = esr_to_fault_info(esr);
641 set_thread_esr(addr, esr);
642 if (fault & VM_FAULT_SIGBUS) {
643
644
645
646
647 arm64_force_sig_fault(SIGBUS, BUS_ADRERR, far, inf->name);
648 } else if (fault & (VM_FAULT_HWPOISON_LARGE | VM_FAULT_HWPOISON)) {
649 unsigned int lsb;
650
651 lsb = PAGE_SHIFT;
652 if (fault & VM_FAULT_HWPOISON_LARGE)
653 lsb = hstate_index_to_shift(VM_FAULT_GET_HINDEX(fault));
654
655 arm64_force_sig_mceerr(BUS_MCEERR_AR, far, lsb, inf->name);
656 } else {
657
658
659
660
661 arm64_force_sig_fault(SIGSEGV,
662 fault == VM_FAULT_BADACCESS ? SEGV_ACCERR : SEGV_MAPERR,
663 far, inf->name);
664 }
665
666 return 0;
667
668no_context:
669 __do_kernel_fault(addr, esr, regs);
670 return 0;
671}
672
673static int __kprobes do_translation_fault(unsigned long far,
674 unsigned int esr,
675 struct pt_regs *regs)
676{
677 unsigned long addr = untagged_addr(far);
678
679 if (is_ttbr0_addr(addr))
680 return do_page_fault(far, esr, regs);
681
682 do_bad_area(far, esr, regs);
683 return 0;
684}
685
686static int do_alignment_fault(unsigned long far, unsigned int esr,
687 struct pt_regs *regs)
688{
689 do_bad_area(far, esr, regs);
690 return 0;
691}
692
693static int do_bad(unsigned long far, unsigned int esr, struct pt_regs *regs)
694{
695 return 1;
696}
697
698static int do_sea(unsigned long far, unsigned int esr, struct pt_regs *regs)
699{
700 const struct fault_info *inf;
701 unsigned long siaddr;
702
703 inf = esr_to_fault_info(esr);
704
705 if (user_mode(regs) && apei_claim_sea(regs) == 0) {
706
707
708
709
710 return 0;
711 }
712
713 if (esr & ESR_ELx_FnV) {
714 siaddr = 0;
715 } else {
716
717
718
719
720
721 siaddr = untagged_addr(far);
722 }
723 arm64_notify_die(inf->name, regs, inf->sig, inf->code, siaddr, esr);
724
725 return 0;
726}
727
728static int do_tag_check_fault(unsigned long far, unsigned int esr,
729 struct pt_regs *regs)
730{
731
732
733
734
735
736 far = (__untagged_addr(far) & ~MTE_TAG_MASK) | (far & MTE_TAG_MASK);
737 do_bad_area(far, esr, regs);
738 return 0;
739}
740
741static const struct fault_info fault_info[] = {
742 { do_bad, SIGKILL, SI_KERNEL, "ttbr address size fault" },
743 { do_bad, SIGKILL, SI_KERNEL, "level 1 address size fault" },
744 { do_bad, SIGKILL, SI_KERNEL, "level 2 address size fault" },
745 { do_bad, SIGKILL, SI_KERNEL, "level 3 address size fault" },
746 { do_translation_fault, SIGSEGV, SEGV_MAPERR, "level 0 translation fault" },
747 { do_translation_fault, SIGSEGV, SEGV_MAPERR, "level 1 translation fault" },
748 { do_translation_fault, SIGSEGV, SEGV_MAPERR, "level 2 translation fault" },
749 { do_translation_fault, SIGSEGV, SEGV_MAPERR, "level 3 translation fault" },
750 { do_bad, SIGKILL, SI_KERNEL, "unknown 8" },
751 { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 1 access flag fault" },
752 { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 2 access flag fault" },
753 { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 3 access flag fault" },
754 { do_bad, SIGKILL, SI_KERNEL, "unknown 12" },
755 { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 1 permission fault" },
756 { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 2 permission fault" },
757 { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 3 permission fault" },
758 { do_sea, SIGBUS, BUS_OBJERR, "synchronous external abort" },
759 { do_tag_check_fault, SIGSEGV, SEGV_MTESERR, "synchronous tag check fault" },
760 { do_bad, SIGKILL, SI_KERNEL, "unknown 18" },
761 { do_bad, SIGKILL, SI_KERNEL, "unknown 19" },
762 { do_sea, SIGKILL, SI_KERNEL, "level 0 (translation table walk)" },
763 { do_sea, SIGKILL, SI_KERNEL, "level 1 (translation table walk)" },
764 { do_sea, SIGKILL, SI_KERNEL, "level 2 (translation table walk)" },
765 { do_sea, SIGKILL, SI_KERNEL, "level 3 (translation table walk)" },
766 { do_sea, SIGBUS, BUS_OBJERR, "synchronous parity or ECC error" },
767 { do_bad, SIGKILL, SI_KERNEL, "unknown 25" },
768 { do_bad, SIGKILL, SI_KERNEL, "unknown 26" },
769 { do_bad, SIGKILL, SI_KERNEL, "unknown 27" },
770 { do_sea, SIGKILL, SI_KERNEL, "level 0 synchronous parity error (translation table walk)" },
771 { do_sea, SIGKILL, SI_KERNEL, "level 1 synchronous parity error (translation table walk)" },
772 { do_sea, SIGKILL, SI_KERNEL, "level 2 synchronous parity error (translation table walk)" },
773 { do_sea, SIGKILL, SI_KERNEL, "level 3 synchronous parity error (translation table walk)" },
774 { do_bad, SIGKILL, SI_KERNEL, "unknown 32" },
775 { do_alignment_fault, SIGBUS, BUS_ADRALN, "alignment fault" },
776 { do_bad, SIGKILL, SI_KERNEL, "unknown 34" },
777 { do_bad, SIGKILL, SI_KERNEL, "unknown 35" },
778 { do_bad, SIGKILL, SI_KERNEL, "unknown 36" },
779 { do_bad, SIGKILL, SI_KERNEL, "unknown 37" },
780 { do_bad, SIGKILL, SI_KERNEL, "unknown 38" },
781 { do_bad, SIGKILL, SI_KERNEL, "unknown 39" },
782 { do_bad, SIGKILL, SI_KERNEL, "unknown 40" },
783 { do_bad, SIGKILL, SI_KERNEL, "unknown 41" },
784 { do_bad, SIGKILL, SI_KERNEL, "unknown 42" },
785 { do_bad, SIGKILL, SI_KERNEL, "unknown 43" },
786 { do_bad, SIGKILL, SI_KERNEL, "unknown 44" },
787 { do_bad, SIGKILL, SI_KERNEL, "unknown 45" },
788 { do_bad, SIGKILL, SI_KERNEL, "unknown 46" },
789 { do_bad, SIGKILL, SI_KERNEL, "unknown 47" },
790 { do_bad, SIGKILL, SI_KERNEL, "TLB conflict abort" },
791 { do_bad, SIGKILL, SI_KERNEL, "Unsupported atomic hardware update fault" },
792 { do_bad, SIGKILL, SI_KERNEL, "unknown 50" },
793 { do_bad, SIGKILL, SI_KERNEL, "unknown 51" },
794 { do_bad, SIGKILL, SI_KERNEL, "implementation fault (lockdown abort)" },
795 { do_bad, SIGBUS, BUS_OBJERR, "implementation fault (unsupported exclusive)" },
796 { do_bad, SIGKILL, SI_KERNEL, "unknown 54" },
797 { do_bad, SIGKILL, SI_KERNEL, "unknown 55" },
798 { do_bad, SIGKILL, SI_KERNEL, "unknown 56" },
799 { do_bad, SIGKILL, SI_KERNEL, "unknown 57" },
800 { do_bad, SIGKILL, SI_KERNEL, "unknown 58" },
801 { do_bad, SIGKILL, SI_KERNEL, "unknown 59" },
802 { do_bad, SIGKILL, SI_KERNEL, "unknown 60" },
803 { do_bad, SIGKILL, SI_KERNEL, "section domain fault" },
804 { do_bad, SIGKILL, SI_KERNEL, "page domain fault" },
805 { do_bad, SIGKILL, SI_KERNEL, "unknown 63" },
806};
807
808void do_mem_abort(unsigned long far, unsigned int esr, struct pt_regs *regs)
809{
810 const struct fault_info *inf = esr_to_fault_info(esr);
811 unsigned long addr = untagged_addr(far);
812
813 if (!inf->fn(far, esr, regs))
814 return;
815
816 if (!user_mode(regs)) {
817 pr_alert("Unhandled fault at 0x%016lx\n", addr);
818 mem_abort_decode(esr);
819 show_pte(addr);
820 }
821
822
823
824
825
826
827 arm64_notify_die(inf->name, regs, inf->sig, inf->code, addr, esr);
828}
829NOKPROBE_SYMBOL(do_mem_abort);
830
831void do_sp_pc_abort(unsigned long addr, unsigned int esr, struct pt_regs *regs)
832{
833 arm64_notify_die("SP/PC alignment exception", regs, SIGBUS, BUS_ADRALN,
834 addr, esr);
835}
836NOKPROBE_SYMBOL(do_sp_pc_abort);
837
838int __init early_brk64(unsigned long addr, unsigned int esr,
839 struct pt_regs *regs);
840
841
842
843
844
845
846static struct fault_info __refdata debug_fault_info[] = {
847 { do_bad, SIGTRAP, TRAP_HWBKPT, "hardware breakpoint" },
848 { do_bad, SIGTRAP, TRAP_HWBKPT, "hardware single-step" },
849 { do_bad, SIGTRAP, TRAP_HWBKPT, "hardware watchpoint" },
850 { do_bad, SIGKILL, SI_KERNEL, "unknown 3" },
851 { do_bad, SIGTRAP, TRAP_BRKPT, "aarch32 BKPT" },
852 { do_bad, SIGKILL, SI_KERNEL, "aarch32 vector catch" },
853 { early_brk64, SIGTRAP, TRAP_BRKPT, "aarch64 BRK" },
854 { do_bad, SIGKILL, SI_KERNEL, "unknown 7" },
855};
856
857void __init hook_debug_fault_code(int nr,
858 int (*fn)(unsigned long, unsigned int, struct pt_regs *),
859 int sig, int code, const char *name)
860{
861 BUG_ON(nr < 0 || nr >= ARRAY_SIZE(debug_fault_info));
862
863 debug_fault_info[nr].fn = fn;
864 debug_fault_info[nr].sig = sig;
865 debug_fault_info[nr].code = code;
866 debug_fault_info[nr].name = name;
867}
868
869
870
871
872
873
874
875
876static void debug_exception_enter(struct pt_regs *regs)
877{
878 preempt_disable();
879
880
881 RCU_LOCKDEP_WARN(!rcu_is_watching(), "exception_enter didn't work");
882}
883NOKPROBE_SYMBOL(debug_exception_enter);
884
885static void debug_exception_exit(struct pt_regs *regs)
886{
887 preempt_enable_no_resched();
888}
889NOKPROBE_SYMBOL(debug_exception_exit);
890
891void do_debug_exception(unsigned long addr_if_watchpoint, unsigned int esr,
892 struct pt_regs *regs)
893{
894 const struct fault_info *inf = esr_to_debug_fault_info(esr);
895 unsigned long pc = instruction_pointer(regs);
896
897 debug_exception_enter(regs);
898
899 if (user_mode(regs) && !is_ttbr0_addr(pc))
900 arm64_apply_bp_hardening();
901
902 if (inf->fn(addr_if_watchpoint, esr, regs)) {
903 arm64_notify_die(inf->name, regs, inf->sig, inf->code, pc, esr);
904 }
905
906 debug_exception_exit(regs);
907}
908NOKPROBE_SYMBOL(do_debug_exception);
909
910
911
912
913struct page *alloc_zeroed_user_highpage_movable(struct vm_area_struct *vma,
914 unsigned long vaddr)
915{
916 gfp_t flags = GFP_HIGHUSER_MOVABLE | __GFP_ZERO;
917
918
919
920
921
922
923 if (vma->vm_flags & VM_MTE)
924 flags |= __GFP_ZEROTAGS;
925
926 return alloc_page_vma(flags, vma, vaddr);
927}
928
929void tag_clear_highpage(struct page *page)
930{
931 mte_zero_clear_page_tags(page_address(page));
932 page_kasan_tag_reset(page);
933 set_bit(PG_mte_tagged, &page->flags);
934}
935