1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * linux/arch/arm/mm/fault.c |
4 | * |
5 | * Copyright (C) 1995 Linus Torvalds |
6 | * Modifications for ARM processor (c) 1995-2004 Russell King |
7 | */ |
8 | #include <linux/extable.h> |
9 | #include <linux/signal.h> |
10 | #include <linux/mm.h> |
11 | #include <linux/hardirq.h> |
12 | #include <linux/init.h> |
13 | #include <linux/kprobes.h> |
14 | #include <linux/uaccess.h> |
15 | #include <linux/page-flags.h> |
16 | #include <linux/sched/signal.h> |
17 | #include <linux/sched/debug.h> |
18 | #include <linux/highmem.h> |
19 | #include <linux/perf_event.h> |
20 | #include <linux/kfence.h> |
21 | |
22 | #include <asm/system_misc.h> |
23 | #include <asm/system_info.h> |
24 | #include <asm/tlbflush.h> |
25 | |
26 | #include "fault.h" |
27 | |
28 | bool copy_from_kernel_nofault_allowed(const void *unsafe_src, size_t size) |
29 | { |
30 | unsigned long addr = (unsigned long)unsafe_src; |
31 | |
32 | return addr >= TASK_SIZE && ULONG_MAX - addr >= size; |
33 | } |
34 | |
35 | #ifdef CONFIG_MMU |
36 | |
37 | /* |
38 | * This is useful to dump out the page tables associated with |
39 | * 'addr' in mm 'mm'. |
40 | */ |
41 | void show_pte(const char *lvl, struct mm_struct *mm, unsigned long addr) |
42 | { |
43 | pgd_t *pgd; |
44 | |
45 | if (!mm) |
46 | mm = &init_mm; |
47 | |
48 | pgd = pgd_offset(mm, addr); |
49 | printk("%s[%08lx] *pgd=%08llx" , lvl, addr, (long long)pgd_val(*pgd)); |
50 | |
51 | do { |
52 | p4d_t *p4d; |
53 | pud_t *pud; |
54 | pmd_t *pmd; |
55 | pte_t *pte; |
56 | |
57 | p4d = p4d_offset(pgd, address: addr); |
58 | if (p4d_none(p4d: *p4d)) |
59 | break; |
60 | |
61 | if (p4d_bad(p4d: *p4d)) { |
62 | pr_cont("(bad)" ); |
63 | break; |
64 | } |
65 | |
66 | pud = pud_offset(p4d, address: addr); |
67 | if (PTRS_PER_PUD != 1) |
68 | pr_cont(", *pud=%08llx" , (long long)pud_val(*pud)); |
69 | |
70 | if (pud_none(pud: *pud)) |
71 | break; |
72 | |
73 | if (pud_bad(pud: *pud)) { |
74 | pr_cont("(bad)" ); |
75 | break; |
76 | } |
77 | |
78 | pmd = pmd_offset(pud, address: addr); |
79 | if (PTRS_PER_PMD != 1) |
80 | pr_cont(", *pmd=%08llx" , (long long)pmd_val(*pmd)); |
81 | |
82 | if (pmd_none(pmd: *pmd)) |
83 | break; |
84 | |
85 | if (pmd_bad(pmd: *pmd)) { |
86 | pr_cont("(bad)" ); |
87 | break; |
88 | } |
89 | |
90 | /* We must not map this if we have highmem enabled */ |
91 | if (PageHighMem(pfn_to_page(pmd_val(*pmd) >> PAGE_SHIFT))) |
92 | break; |
93 | |
94 | pte = pte_offset_map(pmd, addr); |
95 | if (!pte) |
96 | break; |
97 | |
98 | pr_cont(", *pte=%08llx" , (long long)pte_val(*pte)); |
99 | #ifndef CONFIG_ARM_LPAE |
100 | pr_cont(", *ppte=%08llx" , |
101 | (long long)pte_val(pte[PTE_HWTABLE_PTRS])); |
102 | #endif |
103 | pte_unmap(pte); |
104 | } while(0); |
105 | |
106 | pr_cont("\n" ); |
107 | } |
108 | #else /* CONFIG_MMU */ |
109 | void show_pte(const char *lvl, struct mm_struct *mm, unsigned long addr) |
110 | { } |
111 | #endif /* CONFIG_MMU */ |
112 | |
113 | static inline bool is_write_fault(unsigned int fsr) |
114 | { |
115 | return (fsr & FSR_WRITE) && !(fsr & FSR_CM); |
116 | } |
117 | |
118 | static inline bool is_translation_fault(unsigned int fsr) |
119 | { |
120 | int fs = fsr_fs(fsr); |
121 | #ifdef CONFIG_ARM_LPAE |
122 | if ((fs & FS_MMU_NOLL_MASK) == FS_TRANS_NOLL) |
123 | return true; |
124 | #else |
125 | if (fs == FS_L1_TRANS || fs == FS_L2_TRANS) |
126 | return true; |
127 | #endif |
128 | return false; |
129 | } |
130 | |
131 | static void die_kernel_fault(const char *msg, struct mm_struct *mm, |
132 | unsigned long addr, unsigned int fsr, |
133 | struct pt_regs *regs) |
134 | { |
135 | bust_spinlocks(yes: 1); |
136 | pr_alert("8<--- cut here ---\n" ); |
137 | pr_alert("Unable to handle kernel %s at virtual address %08lx when %s\n" , |
138 | msg, addr, fsr & FSR_LNX_PF ? "execute" : |
139 | fsr & FSR_WRITE ? "write" : "read" ); |
140 | |
141 | show_pte(KERN_ALERT, mm, addr); |
142 | die("Oops" , regs, fsr); |
143 | bust_spinlocks(yes: 0); |
144 | make_task_dead(SIGKILL); |
145 | } |
146 | |
147 | /* |
148 | * Oops. The kernel tried to access some page that wasn't present. |
149 | */ |
150 | static void |
151 | __do_kernel_fault(struct mm_struct *mm, unsigned long addr, unsigned int fsr, |
152 | struct pt_regs *regs) |
153 | { |
154 | const char *msg; |
155 | /* |
156 | * Are we prepared to handle this kernel fault? |
157 | */ |
158 | if (fixup_exception(regs)) |
159 | return; |
160 | |
161 | /* |
162 | * No handler, we'll have to terminate things with extreme prejudice. |
163 | */ |
164 | if (addr < PAGE_SIZE) { |
165 | msg = "NULL pointer dereference" ; |
166 | } else { |
167 | if (is_translation_fault(fsr) && |
168 | kfence_handle_page_fault(addr, is_write: is_write_fault(fsr), regs)) |
169 | return; |
170 | |
171 | msg = "paging request" ; |
172 | } |
173 | |
174 | die_kernel_fault(msg, mm, addr, fsr, regs); |
175 | } |
176 | |
177 | /* |
178 | * Something tried to access memory that isn't in our memory map.. |
179 | * User mode accesses just cause a SIGSEGV |
180 | */ |
181 | static void |
182 | __do_user_fault(unsigned long addr, unsigned int fsr, unsigned int sig, |
183 | int code, struct pt_regs *regs) |
184 | { |
185 | struct task_struct *tsk = current; |
186 | |
187 | if (addr > TASK_SIZE) |
188 | harden_branch_predictor(); |
189 | |
190 | #ifdef CONFIG_DEBUG_USER |
191 | if (((user_debug & UDBG_SEGV) && (sig == SIGSEGV)) || |
192 | ((user_debug & UDBG_BUS) && (sig == SIGBUS))) { |
193 | pr_err("8<--- cut here ---\n" ); |
194 | pr_err("%s: unhandled page fault (%d) at 0x%08lx, code 0x%03x\n" , |
195 | tsk->comm, sig, addr, fsr); |
196 | show_pte(KERN_ERR, tsk->mm, addr); |
197 | show_regs(regs); |
198 | } |
199 | #endif |
200 | #ifndef CONFIG_KUSER_HELPERS |
201 | if ((sig == SIGSEGV) && ((addr & PAGE_MASK) == 0xffff0000)) |
202 | printk_ratelimited(KERN_DEBUG |
203 | "%s: CONFIG_KUSER_HELPERS disabled at 0x%08lx\n" , |
204 | tsk->comm, addr); |
205 | #endif |
206 | |
207 | tsk->thread.address = addr; |
208 | tsk->thread.error_code = fsr; |
209 | tsk->thread.trap_no = 14; |
210 | force_sig_fault(sig, code, addr: (void __user *)addr); |
211 | } |
212 | |
213 | void do_bad_area(unsigned long addr, unsigned int fsr, struct pt_regs *regs) |
214 | { |
215 | struct task_struct *tsk = current; |
216 | struct mm_struct *mm = tsk->active_mm; |
217 | |
218 | /* |
219 | * If we are in kernel mode at this point, we |
220 | * have no context to handle this fault with. |
221 | */ |
222 | if (user_mode(regs)) |
223 | __do_user_fault(addr, fsr, SIGSEGV, SEGV_MAPERR, regs); |
224 | else |
225 | __do_kernel_fault(mm, addr, fsr, regs); |
226 | } |
227 | |
228 | #ifdef CONFIG_MMU |
229 | #define VM_FAULT_BADMAP ((__force vm_fault_t)0x010000) |
230 | #define VM_FAULT_BADACCESS ((__force vm_fault_t)0x020000) |
231 | |
232 | static inline bool is_permission_fault(unsigned int fsr) |
233 | { |
234 | int fs = fsr_fs(fsr); |
235 | #ifdef CONFIG_ARM_LPAE |
236 | if ((fs & FS_MMU_NOLL_MASK) == FS_PERM_NOLL) |
237 | return true; |
238 | #else |
239 | if (fs == FS_L1_PERM || fs == FS_L2_PERM) |
240 | return true; |
241 | #endif |
242 | return false; |
243 | } |
244 | |
245 | static int __kprobes |
246 | do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs) |
247 | { |
248 | struct mm_struct *mm = current->mm; |
249 | struct vm_area_struct *vma; |
250 | int sig, code; |
251 | vm_fault_t fault; |
252 | unsigned int flags = FAULT_FLAG_DEFAULT; |
253 | unsigned long vm_flags = VM_ACCESS_FLAGS; |
254 | |
255 | if (kprobe_page_fault(regs, trap: fsr)) |
256 | return 0; |
257 | |
258 | |
259 | /* Enable interrupts if they were enabled in the parent context. */ |
260 | if (interrupts_enabled(regs)) |
261 | local_irq_enable(); |
262 | |
263 | /* |
264 | * If we're in an interrupt or have no user |
265 | * context, we must not take the fault.. |
266 | */ |
267 | if (faulthandler_disabled() || !mm) |
268 | goto no_context; |
269 | |
270 | if (user_mode(regs)) |
271 | flags |= FAULT_FLAG_USER; |
272 | |
273 | if (is_write_fault(fsr)) { |
274 | flags |= FAULT_FLAG_WRITE; |
275 | vm_flags = VM_WRITE; |
276 | } |
277 | |
278 | if (fsr & FSR_LNX_PF) { |
279 | vm_flags = VM_EXEC; |
280 | |
281 | if (is_permission_fault(fsr) && !user_mode(regs)) |
282 | die_kernel_fault(msg: "execution of memory" , |
283 | mm, addr, fsr, regs); |
284 | } |
285 | |
286 | perf_sw_event(event_id: PERF_COUNT_SW_PAGE_FAULTS, nr: 1, regs, addr); |
287 | |
288 | if (!(flags & FAULT_FLAG_USER)) |
289 | goto lock_mmap; |
290 | |
291 | vma = lock_vma_under_rcu(mm, address: addr); |
292 | if (!vma) |
293 | goto lock_mmap; |
294 | |
295 | if (!(vma->vm_flags & vm_flags)) { |
296 | vma_end_read(vma); |
297 | goto lock_mmap; |
298 | } |
299 | fault = handle_mm_fault(vma, address: addr, flags: flags | FAULT_FLAG_VMA_LOCK, regs); |
300 | if (!(fault & (VM_FAULT_RETRY | VM_FAULT_COMPLETED))) |
301 | vma_end_read(vma); |
302 | |
303 | if (!(fault & VM_FAULT_RETRY)) { |
304 | count_vm_vma_lock_event(VMA_LOCK_SUCCESS); |
305 | goto done; |
306 | } |
307 | count_vm_vma_lock_event(VMA_LOCK_RETRY); |
308 | if (fault & VM_FAULT_MAJOR) |
309 | flags |= FAULT_FLAG_TRIED; |
310 | |
311 | /* Quick path to respond to signals */ |
312 | if (fault_signal_pending(fault_flags: fault, regs)) { |
313 | if (!user_mode(regs)) |
314 | goto no_context; |
315 | return 0; |
316 | } |
317 | lock_mmap: |
318 | |
319 | retry: |
320 | vma = lock_mm_and_find_vma(mm, address: addr, regs); |
321 | if (unlikely(!vma)) { |
322 | fault = VM_FAULT_BADMAP; |
323 | goto bad_area; |
324 | } |
325 | |
326 | /* |
327 | * ok, we have a good vm_area for this memory access, check the |
328 | * permissions on the VMA allow for the fault which occurred. |
329 | */ |
330 | if (!(vma->vm_flags & vm_flags)) |
331 | fault = VM_FAULT_BADACCESS; |
332 | else |
333 | fault = handle_mm_fault(vma, address: addr & PAGE_MASK, flags, regs); |
334 | |
335 | /* If we need to retry but a fatal signal is pending, handle the |
336 | * signal first. We do not need to release the mmap_lock because |
337 | * it would already be released in __lock_page_or_retry in |
338 | * mm/filemap.c. */ |
339 | if (fault_signal_pending(fault_flags: fault, regs)) { |
340 | if (!user_mode(regs)) |
341 | goto no_context; |
342 | return 0; |
343 | } |
344 | |
345 | /* The fault is fully completed (including releasing mmap lock) */ |
346 | if (fault & VM_FAULT_COMPLETED) |
347 | return 0; |
348 | |
349 | if (!(fault & VM_FAULT_ERROR)) { |
350 | if (fault & VM_FAULT_RETRY) { |
351 | flags |= FAULT_FLAG_TRIED; |
352 | goto retry; |
353 | } |
354 | } |
355 | |
356 | mmap_read_unlock(mm); |
357 | done: |
358 | |
359 | /* |
360 | * Handle the "normal" case first - VM_FAULT_MAJOR |
361 | */ |
362 | if (likely(!(fault & (VM_FAULT_ERROR | VM_FAULT_BADMAP | VM_FAULT_BADACCESS)))) |
363 | return 0; |
364 | |
365 | bad_area: |
366 | /* |
367 | * If we are in kernel mode at this point, we |
368 | * have no context to handle this fault with. |
369 | */ |
370 | if (!user_mode(regs)) |
371 | goto no_context; |
372 | |
373 | if (fault & VM_FAULT_OOM) { |
374 | /* |
375 | * We ran out of memory, call the OOM killer, and return to |
376 | * userspace (which will retry the fault, or kill us if we |
377 | * got oom-killed) |
378 | */ |
379 | pagefault_out_of_memory(); |
380 | return 0; |
381 | } |
382 | |
383 | if (fault & VM_FAULT_SIGBUS) { |
384 | /* |
385 | * We had some memory, but were unable to |
386 | * successfully fix up this page fault. |
387 | */ |
388 | sig = SIGBUS; |
389 | code = BUS_ADRERR; |
390 | } else { |
391 | /* |
392 | * Something tried to access memory that |
393 | * isn't in our memory map.. |
394 | */ |
395 | sig = SIGSEGV; |
396 | code = fault == VM_FAULT_BADACCESS ? |
397 | SEGV_ACCERR : SEGV_MAPERR; |
398 | } |
399 | |
400 | __do_user_fault(addr, fsr, sig, code, regs); |
401 | return 0; |
402 | |
403 | no_context: |
404 | __do_kernel_fault(mm, addr, fsr, regs); |
405 | return 0; |
406 | } |
407 | #else /* CONFIG_MMU */ |
408 | static int |
409 | do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs) |
410 | { |
411 | return 0; |
412 | } |
413 | #endif /* CONFIG_MMU */ |
414 | |
415 | /* |
416 | * First Level Translation Fault Handler |
417 | * |
418 | * We enter here because the first level page table doesn't contain |
419 | * a valid entry for the address. |
420 | * |
421 | * If the address is in kernel space (>= TASK_SIZE), then we are |
422 | * probably faulting in the vmalloc() area. |
423 | * |
424 | * If the init_task's first level page tables contains the relevant |
425 | * entry, we copy the it to this task. If not, we send the process |
426 | * a signal, fixup the exception, or oops the kernel. |
427 | * |
428 | * NOTE! We MUST NOT take any locks for this case. We may be in an |
429 | * interrupt or a critical region, and should only copy the information |
430 | * from the master page table, nothing more. |
431 | */ |
432 | #ifdef CONFIG_MMU |
433 | static int __kprobes |
434 | do_translation_fault(unsigned long addr, unsigned int fsr, |
435 | struct pt_regs *regs) |
436 | { |
437 | unsigned int index; |
438 | pgd_t *pgd, *pgd_k; |
439 | p4d_t *p4d, *p4d_k; |
440 | pud_t *pud, *pud_k; |
441 | pmd_t *pmd, *pmd_k; |
442 | |
443 | if (addr < TASK_SIZE) |
444 | return do_page_fault(addr, fsr, regs); |
445 | |
446 | if (user_mode(regs)) |
447 | goto bad_area; |
448 | |
449 | index = pgd_index(addr); |
450 | |
451 | pgd = cpu_get_pgd() + index; |
452 | pgd_k = init_mm.pgd + index; |
453 | |
454 | p4d = p4d_offset(pgd, address: addr); |
455 | p4d_k = p4d_offset(pgd: pgd_k, address: addr); |
456 | |
457 | if (p4d_none(p4d: *p4d_k)) |
458 | goto bad_area; |
459 | if (!p4d_present(p4d: *p4d)) |
460 | set_p4d(p4dp: p4d, p4d: *p4d_k); |
461 | |
462 | pud = pud_offset(p4d, address: addr); |
463 | pud_k = pud_offset(p4d: p4d_k, address: addr); |
464 | |
465 | if (pud_none(pud: *pud_k)) |
466 | goto bad_area; |
467 | if (!pud_present(pud: *pud)) |
468 | set_pud(pudp: pud, pud: *pud_k); |
469 | |
470 | pmd = pmd_offset(pud, address: addr); |
471 | pmd_k = pmd_offset(pud: pud_k, address: addr); |
472 | |
473 | #ifdef CONFIG_ARM_LPAE |
474 | /* |
475 | * Only one hardware entry per PMD with LPAE. |
476 | */ |
477 | index = 0; |
478 | #else |
479 | /* |
480 | * On ARM one Linux PGD entry contains two hardware entries (see page |
481 | * tables layout in pgtable.h). We normally guarantee that we always |
482 | * fill both L1 entries. But create_mapping() doesn't follow the rule. |
483 | * It can create inidividual L1 entries, so here we have to call |
484 | * pmd_none() check for the entry really corresponded to address, not |
485 | * for the first of pair. |
486 | */ |
487 | index = (addr >> SECTION_SHIFT) & 1; |
488 | #endif |
489 | if (pmd_none(pmd: pmd_k[index])) |
490 | goto bad_area; |
491 | |
492 | copy_pmd(pmd, pmd_k); |
493 | return 0; |
494 | |
495 | bad_area: |
496 | do_bad_area(addr, fsr, regs); |
497 | return 0; |
498 | } |
499 | #else /* CONFIG_MMU */ |
500 | static int |
501 | do_translation_fault(unsigned long addr, unsigned int fsr, |
502 | struct pt_regs *regs) |
503 | { |
504 | return 0; |
505 | } |
506 | #endif /* CONFIG_MMU */ |
507 | |
508 | /* |
509 | * Some section permission faults need to be handled gracefully. |
510 | * They can happen due to a __{get,put}_user during an oops. |
511 | */ |
512 | #ifndef CONFIG_ARM_LPAE |
513 | static int |
514 | do_sect_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs) |
515 | { |
516 | do_bad_area(addr, fsr, regs); |
517 | return 0; |
518 | } |
519 | #endif /* CONFIG_ARM_LPAE */ |
520 | |
521 | /* |
522 | * This abort handler always returns "fault". |
523 | */ |
524 | static int |
525 | do_bad(unsigned long addr, unsigned int fsr, struct pt_regs *regs) |
526 | { |
527 | return 1; |
528 | } |
529 | |
530 | struct fsr_info { |
531 | int (*fn)(unsigned long addr, unsigned int fsr, struct pt_regs *regs); |
532 | int sig; |
533 | int code; |
534 | const char *name; |
535 | }; |
536 | |
537 | /* FSR definition */ |
538 | #ifdef CONFIG_ARM_LPAE |
539 | #include "fsr-3level.c" |
540 | #else |
541 | #include "fsr-2level.c" |
542 | #endif |
543 | |
544 | void __init |
545 | hook_fault_code(int nr, int (*fn)(unsigned long, unsigned int, struct pt_regs *), |
546 | int sig, int code, const char *name) |
547 | { |
548 | if (nr < 0 || nr >= ARRAY_SIZE(fsr_info)) |
549 | BUG(); |
550 | |
551 | fsr_info[nr].fn = fn; |
552 | fsr_info[nr].sig = sig; |
553 | fsr_info[nr].code = code; |
554 | fsr_info[nr].name = name; |
555 | } |
556 | |
557 | /* |
558 | * Dispatch a data abort to the relevant handler. |
559 | */ |
560 | asmlinkage void |
561 | do_DataAbort(unsigned long addr, unsigned int fsr, struct pt_regs *regs) |
562 | { |
563 | const struct fsr_info *inf = fsr_info + fsr_fs(fsr); |
564 | |
565 | if (!inf->fn(addr, fsr & ~FSR_LNX_PF, regs)) |
566 | return; |
567 | |
568 | pr_alert("8<--- cut here ---\n" ); |
569 | pr_alert("Unhandled fault: %s (0x%03x) at 0x%08lx\n" , |
570 | inf->name, fsr, addr); |
571 | show_pte(KERN_ALERT, current->mm, addr); |
572 | |
573 | arm_notify_die("" , regs, inf->sig, inf->code, (void __user *)addr, |
574 | fsr, 0); |
575 | } |
576 | |
577 | void __init |
578 | hook_ifault_code(int nr, int (*fn)(unsigned long, unsigned int, struct pt_regs *), |
579 | int sig, int code, const char *name) |
580 | { |
581 | if (nr < 0 || nr >= ARRAY_SIZE(ifsr_info)) |
582 | BUG(); |
583 | |
584 | ifsr_info[nr].fn = fn; |
585 | ifsr_info[nr].sig = sig; |
586 | ifsr_info[nr].code = code; |
587 | ifsr_info[nr].name = name; |
588 | } |
589 | |
590 | asmlinkage void |
591 | do_PrefetchAbort(unsigned long addr, unsigned int ifsr, struct pt_regs *regs) |
592 | { |
593 | const struct fsr_info *inf = ifsr_info + fsr_fs(fsr: ifsr); |
594 | |
595 | if (!inf->fn(addr, ifsr | FSR_LNX_PF, regs)) |
596 | return; |
597 | |
598 | pr_alert("8<--- cut here ---\n" ); |
599 | pr_alert("Unhandled prefetch abort: %s (0x%03x) at 0x%08lx\n" , |
600 | inf->name, ifsr, addr); |
601 | |
602 | arm_notify_die("" , regs, inf->sig, inf->code, (void __user *)addr, |
603 | ifsr, 0); |
604 | } |
605 | |
606 | /* |
607 | * Abort handler to be used only during first unmasking of asynchronous aborts |
608 | * on the boot CPU. This makes sure that the machine will not die if the |
609 | * firmware/bootloader left an imprecise abort pending for us to trip over. |
610 | */ |
611 | static int __init early_abort_handler(unsigned long addr, unsigned int fsr, |
612 | struct pt_regs *regs) |
613 | { |
614 | pr_warn("Hit pending asynchronous external abort (FSR=0x%08x) during " |
615 | "first unmask, this is most likely caused by a " |
616 | "firmware/bootloader bug.\n" , fsr); |
617 | |
618 | return 0; |
619 | } |
620 | |
621 | void __init early_abt_enable(void) |
622 | { |
623 | fsr_info[FSR_FS_AEA].fn = early_abort_handler; |
624 | local_abt_enable(); |
625 | fsr_info[FSR_FS_AEA].fn = do_bad; |
626 | } |
627 | |
628 | #ifndef CONFIG_ARM_LPAE |
629 | static int __init exceptions_init(void) |
630 | { |
631 | if (cpu_architecture() >= CPU_ARCH_ARMv6) { |
632 | hook_fault_code(nr: 4, fn: do_translation_fault, SIGSEGV, SEGV_MAPERR, |
633 | name: "I-cache maintenance fault" ); |
634 | } |
635 | |
636 | if (cpu_architecture() >= CPU_ARCH_ARMv7) { |
637 | /* |
638 | * TODO: Access flag faults introduced in ARMv6K. |
639 | * Runtime check for 'K' extension is needed |
640 | */ |
641 | hook_fault_code(nr: 3, fn: do_bad, SIGSEGV, SEGV_MAPERR, |
642 | name: "section access flag fault" ); |
643 | hook_fault_code(nr: 6, fn: do_bad, SIGSEGV, SEGV_MAPERR, |
644 | name: "section access flag fault" ); |
645 | } |
646 | |
647 | return 0; |
648 | } |
649 | |
650 | arch_initcall(exceptions_init); |
651 | #endif |
652 | |