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1da177e4 LT |
1 | /* |
2 | * linux/arch/arm/mm/fault.c | |
3 | * | |
4 | * Copyright (C) 1995 Linus Torvalds | |
5 | * Modifications for ARM processor (c) 1995-2004 Russell King | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License version 2 as | |
9 | * published by the Free Software Foundation. | |
10 | */ | |
0ea9365a | 11 | #include <linux/extable.h> |
1da177e4 | 12 | #include <linux/signal.h> |
1da177e4 | 13 | #include <linux/mm.h> |
67306da6 | 14 | #include <linux/hardirq.h> |
1da177e4 | 15 | #include <linux/init.h> |
25ce1dd7 | 16 | #include <linux/kprobes.h> |
33fa9b13 | 17 | #include <linux/uaccess.h> |
252d4c27 | 18 | #include <linux/page-flags.h> |
3f07c014 | 19 | #include <linux/sched/signal.h> |
b17b0153 | 20 | #include <linux/sched/debug.h> |
65cec8e3 | 21 | #include <linux/highmem.h> |
7ada189f | 22 | #include <linux/perf_event.h> |
1da177e4 | 23 | |
5a567d78 | 24 | #include <asm/exception.h> |
1da177e4 | 25 | #include <asm/pgtable.h> |
9f97da78 DH |
26 | #include <asm/system_misc.h> |
27 | #include <asm/system_info.h> | |
1da177e4 | 28 | #include <asm/tlbflush.h> |
1da177e4 LT |
29 | |
30 | #include "fault.h" | |
31 | ||
09529f7a | 32 | #ifdef CONFIG_MMU |
25ce1dd7 NP |
33 | |
34 | #ifdef CONFIG_KPROBES | |
35 | static inline int notify_page_fault(struct pt_regs *regs, unsigned int fsr) | |
36 | { | |
37 | int ret = 0; | |
38 | ||
39 | if (!user_mode(regs)) { | |
40 | /* kprobe_running() needs smp_processor_id() */ | |
41 | preempt_disable(); | |
42 | if (kprobe_running() && kprobe_fault_handler(regs, fsr)) | |
43 | ret = 1; | |
44 | preempt_enable(); | |
45 | } | |
46 | ||
47 | return ret; | |
48 | } | |
49 | #else | |
50 | static inline int notify_page_fault(struct pt_regs *regs, unsigned int fsr) | |
51 | { | |
52 | return 0; | |
53 | } | |
54 | #endif | |
55 | ||
1da177e4 LT |
56 | /* |
57 | * This is useful to dump out the page tables associated with | |
58 | * 'addr' in mm 'mm'. | |
59 | */ | |
60 | void show_pte(struct mm_struct *mm, unsigned long addr) | |
61 | { | |
62 | pgd_t *pgd; | |
63 | ||
64 | if (!mm) | |
65 | mm = &init_mm; | |
66 | ||
4ed89f22 | 67 | pr_alert("pgd = %p\n", mm->pgd); |
1da177e4 | 68 | pgd = pgd_offset(mm, addr); |
4ed89f22 | 69 | pr_alert("[%08lx] *pgd=%08llx", |
29a38193 | 70 | addr, (long long)pgd_val(*pgd)); |
1da177e4 LT |
71 | |
72 | do { | |
516295e5 | 73 | pud_t *pud; |
1da177e4 LT |
74 | pmd_t *pmd; |
75 | pte_t *pte; | |
76 | ||
77 | if (pgd_none(*pgd)) | |
78 | break; | |
79 | ||
80 | if (pgd_bad(*pgd)) { | |
4ed89f22 | 81 | pr_cont("(bad)"); |
1da177e4 LT |
82 | break; |
83 | } | |
84 | ||
516295e5 RK |
85 | pud = pud_offset(pgd, addr); |
86 | if (PTRS_PER_PUD != 1) | |
4ed89f22 | 87 | pr_cont(", *pud=%08llx", (long long)pud_val(*pud)); |
516295e5 RK |
88 | |
89 | if (pud_none(*pud)) | |
90 | break; | |
91 | ||
92 | if (pud_bad(*pud)) { | |
4ed89f22 | 93 | pr_cont("(bad)"); |
516295e5 RK |
94 | break; |
95 | } | |
96 | ||
97 | pmd = pmd_offset(pud, addr); | |
da46c79a | 98 | if (PTRS_PER_PMD != 1) |
4ed89f22 | 99 | pr_cont(", *pmd=%08llx", (long long)pmd_val(*pmd)); |
1da177e4 LT |
100 | |
101 | if (pmd_none(*pmd)) | |
102 | break; | |
103 | ||
104 | if (pmd_bad(*pmd)) { | |
4ed89f22 | 105 | pr_cont("(bad)"); |
1da177e4 LT |
106 | break; |
107 | } | |
108 | ||
1da177e4 | 109 | /* We must not map this if we have highmem enabled */ |
252d4c27 NP |
110 | if (PageHighMem(pfn_to_page(pmd_val(*pmd) >> PAGE_SHIFT))) |
111 | break; | |
112 | ||
1da177e4 | 113 | pte = pte_offset_map(pmd, addr); |
4ed89f22 | 114 | pr_cont(", *pte=%08llx", (long long)pte_val(*pte)); |
f7b8156d | 115 | #ifndef CONFIG_ARM_LPAE |
4ed89f22 | 116 | pr_cont(", *ppte=%08llx", |
29a38193 | 117 | (long long)pte_val(pte[PTE_HWTABLE_PTRS])); |
f7b8156d | 118 | #endif |
1da177e4 | 119 | pte_unmap(pte); |
1da177e4 LT |
120 | } while(0); |
121 | ||
4ed89f22 | 122 | pr_cont("\n"); |
1da177e4 | 123 | } |
09529f7a CM |
124 | #else /* CONFIG_MMU */ |
125 | void show_pte(struct mm_struct *mm, unsigned long addr) | |
126 | { } | |
127 | #endif /* CONFIG_MMU */ | |
1da177e4 LT |
128 | |
129 | /* | |
130 | * Oops. The kernel tried to access some page that wasn't present. | |
131 | */ | |
132 | static void | |
133 | __do_kernel_fault(struct mm_struct *mm, unsigned long addr, unsigned int fsr, | |
134 | struct pt_regs *regs) | |
135 | { | |
136 | /* | |
137 | * Are we prepared to handle this kernel fault? | |
138 | */ | |
139 | if (fixup_exception(regs)) | |
140 | return; | |
141 | ||
142 | /* | |
143 | * No handler, we'll have to terminate things with extreme prejudice. | |
144 | */ | |
145 | bust_spinlocks(1); | |
4ed89f22 RK |
146 | pr_alert("Unable to handle kernel %s at virtual address %08lx\n", |
147 | (addr < PAGE_SIZE) ? "NULL pointer dereference" : | |
148 | "paging request", addr); | |
1da177e4 LT |
149 | |
150 | show_pte(mm, addr); | |
151 | die("Oops", regs, fsr); | |
152 | bust_spinlocks(0); | |
153 | do_exit(SIGKILL); | |
154 | } | |
155 | ||
156 | /* | |
157 | * Something tried to access memory that isn't in our memory map.. | |
158 | * User mode accesses just cause a SIGSEGV | |
159 | */ | |
160 | static void | |
161 | __do_user_fault(struct task_struct *tsk, unsigned long addr, | |
2d137c24 | 162 | unsigned int fsr, unsigned int sig, int code, |
163 | struct pt_regs *regs) | |
1da177e4 LT |
164 | { |
165 | struct siginfo si; | |
166 | ||
167 | #ifdef CONFIG_DEBUG_USER | |
f5274c2d JM |
168 | if (((user_debug & UDBG_SEGV) && (sig == SIGSEGV)) || |
169 | ((user_debug & UDBG_BUS) && (sig == SIGBUS))) { | |
2d137c24 | 170 | printk(KERN_DEBUG "%s: unhandled page fault (%d) at 0x%08lx, code 0x%03x\n", |
171 | tsk->comm, sig, addr, fsr); | |
1da177e4 LT |
172 | show_pte(tsk->mm, addr); |
173 | show_regs(regs); | |
174 | } | |
175 | #endif | |
176 | ||
177 | tsk->thread.address = addr; | |
178 | tsk->thread.error_code = fsr; | |
179 | tsk->thread.trap_no = 14; | |
2d137c24 | 180 | si.si_signo = sig; |
1da177e4 LT |
181 | si.si_errno = 0; |
182 | si.si_code = code; | |
183 | si.si_addr = (void __user *)addr; | |
2d137c24 | 184 | force_sig_info(sig, &si, tsk); |
1da177e4 LT |
185 | } |
186 | ||
e5beac37 | 187 | void do_bad_area(unsigned long addr, unsigned int fsr, struct pt_regs *regs) |
1da177e4 | 188 | { |
e5beac37 RK |
189 | struct task_struct *tsk = current; |
190 | struct mm_struct *mm = tsk->active_mm; | |
191 | ||
1da177e4 LT |
192 | /* |
193 | * If we are in kernel mode at this point, we | |
194 | * have no context to handle this fault with. | |
195 | */ | |
196 | if (user_mode(regs)) | |
2d137c24 | 197 | __do_user_fault(tsk, addr, fsr, SIGSEGV, SEGV_MAPERR, regs); |
1da177e4 LT |
198 | else |
199 | __do_kernel_fault(mm, addr, fsr, regs); | |
200 | } | |
201 | ||
09529f7a | 202 | #ifdef CONFIG_MMU |
5c72fc5c NP |
203 | #define VM_FAULT_BADMAP 0x010000 |
204 | #define VM_FAULT_BADACCESS 0x020000 | |
1da177e4 | 205 | |
d374bf14 RK |
206 | /* |
207 | * Check that the permissions on the VMA allow for the fault which occurred. | |
208 | * If we encountered a write fault, we must have write permission, otherwise | |
209 | * we allow any permission. | |
210 | */ | |
211 | static inline bool access_error(unsigned int fsr, struct vm_area_struct *vma) | |
212 | { | |
213 | unsigned int mask = VM_READ | VM_WRITE | VM_EXEC; | |
214 | ||
215 | if (fsr & FSR_WRITE) | |
216 | mask = VM_WRITE; | |
df297bf6 RK |
217 | if (fsr & FSR_LNX_PF) |
218 | mask = VM_EXEC; | |
d374bf14 RK |
219 | |
220 | return vma->vm_flags & mask ? false : true; | |
221 | } | |
222 | ||
223 | static int __kprobes | |
1da177e4 | 224 | __do_page_fault(struct mm_struct *mm, unsigned long addr, unsigned int fsr, |
8878a539 | 225 | unsigned int flags, struct task_struct *tsk) |
1da177e4 LT |
226 | { |
227 | struct vm_area_struct *vma; | |
d374bf14 | 228 | int fault; |
1da177e4 LT |
229 | |
230 | vma = find_vma(mm, addr); | |
231 | fault = VM_FAULT_BADMAP; | |
d374bf14 | 232 | if (unlikely(!vma)) |
1da177e4 | 233 | goto out; |
d374bf14 | 234 | if (unlikely(vma->vm_start > addr)) |
1da177e4 LT |
235 | goto check_stack; |
236 | ||
237 | /* | |
238 | * Ok, we have a good vm_area for this | |
239 | * memory access, so we can handle it. | |
240 | */ | |
241 | good_area: | |
d374bf14 RK |
242 | if (access_error(fsr, vma)) { |
243 | fault = VM_FAULT_BADACCESS; | |
1da177e4 | 244 | goto out; |
d374bf14 | 245 | } |
1da177e4 | 246 | |
dcddffd4 | 247 | return handle_mm_fault(vma, addr & PAGE_MASK, flags); |
1da177e4 | 248 | |
1da177e4 | 249 | check_stack: |
9b61a4d1 RK |
250 | /* Don't allow expansion below FIRST_USER_ADDRESS */ |
251 | if (vma->vm_flags & VM_GROWSDOWN && | |
252 | addr >= FIRST_USER_ADDRESS && !expand_stack(vma, addr)) | |
1da177e4 LT |
253 | goto good_area; |
254 | out: | |
255 | return fault; | |
256 | } | |
257 | ||
785d3cd2 | 258 | static int __kprobes |
1da177e4 LT |
259 | do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs) |
260 | { | |
261 | struct task_struct *tsk; | |
262 | struct mm_struct *mm; | |
2d137c24 | 263 | int fault, sig, code; |
759496ba | 264 | unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE; |
1da177e4 | 265 | |
25ce1dd7 NP |
266 | if (notify_page_fault(regs, fsr)) |
267 | return 0; | |
268 | ||
1da177e4 LT |
269 | tsk = current; |
270 | mm = tsk->mm; | |
271 | ||
02fe2845 RK |
272 | /* Enable interrupts if they were enabled in the parent context. */ |
273 | if (interrupts_enabled(regs)) | |
274 | local_irq_enable(); | |
275 | ||
1da177e4 LT |
276 | /* |
277 | * If we're in an interrupt or have no user | |
278 | * context, we must not take the fault.. | |
279 | */ | |
70ffdb93 | 280 | if (faulthandler_disabled() || !mm) |
1da177e4 LT |
281 | goto no_context; |
282 | ||
759496ba JW |
283 | if (user_mode(regs)) |
284 | flags |= FAULT_FLAG_USER; | |
285 | if (fsr & FSR_WRITE) | |
286 | flags |= FAULT_FLAG_WRITE; | |
287 | ||
840ff6a4 RK |
288 | /* |
289 | * As per x86, we may deadlock here. However, since the kernel only | |
290 | * validly references user space from well defined areas of the code, | |
291 | * we can bug out early if this is from code which shouldn't. | |
292 | */ | |
293 | if (!down_read_trylock(&mm->mmap_sem)) { | |
294 | if (!user_mode(regs) && !search_exception_tables(regs->ARM_pc)) | |
295 | goto no_context; | |
8878a539 | 296 | retry: |
840ff6a4 | 297 | down_read(&mm->mmap_sem); |
bf456992 RK |
298 | } else { |
299 | /* | |
300 | * The above down_read_trylock() might have succeeded in | |
301 | * which case, we'll have missed the might_sleep() from | |
302 | * down_read() | |
303 | */ | |
304 | might_sleep(); | |
1d212712 ID |
305 | #ifdef CONFIG_DEBUG_VM |
306 | if (!user_mode(regs) && | |
307 | !search_exception_tables(regs->ARM_pc)) | |
308 | goto no_context; | |
309 | #endif | |
840ff6a4 RK |
310 | } |
311 | ||
8878a539 KC |
312 | fault = __do_page_fault(mm, addr, fsr, flags, tsk); |
313 | ||
314 | /* If we need to retry but a fatal signal is pending, handle the | |
315 | * signal first. We do not need to release the mmap_sem because | |
316 | * it would already be released in __lock_page_or_retry in | |
317 | * mm/filemap.c. */ | |
0862f029 MR |
318 | if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current)) { |
319 | if (!user_mode(regs)) | |
320 | goto no_context; | |
8878a539 | 321 | return 0; |
0862f029 | 322 | } |
8878a539 KC |
323 | |
324 | /* | |
325 | * Major/minor page fault accounting is only done on the | |
326 | * initial attempt. If we go through a retry, it is extremely | |
327 | * likely that the page will be found in page cache at that point. | |
328 | */ | |
1da177e4 | 329 | |
a8b0ca17 | 330 | perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, addr); |
dff2aa7a | 331 | if (!(fault & VM_FAULT_ERROR) && flags & FAULT_FLAG_ALLOW_RETRY) { |
8878a539 KC |
332 | if (fault & VM_FAULT_MAJOR) { |
333 | tsk->maj_flt++; | |
334 | perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1, | |
335 | regs, addr); | |
336 | } else { | |
337 | tsk->min_flt++; | |
338 | perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, 1, | |
339 | regs, addr); | |
340 | } | |
341 | if (fault & VM_FAULT_RETRY) { | |
342 | /* Clear FAULT_FLAG_ALLOW_RETRY to avoid any risk | |
343 | * of starvation. */ | |
344 | flags &= ~FAULT_FLAG_ALLOW_RETRY; | |
45cac65b | 345 | flags |= FAULT_FLAG_TRIED; |
8878a539 KC |
346 | goto retry; |
347 | } | |
348 | } | |
349 | ||
350 | up_read(&mm->mmap_sem); | |
7ada189f | 351 | |
1da177e4 | 352 | /* |
0e8fb931 | 353 | * Handle the "normal" case first - VM_FAULT_MAJOR |
1da177e4 | 354 | */ |
5c72fc5c | 355 | if (likely(!(fault & (VM_FAULT_ERROR | VM_FAULT_BADMAP | VM_FAULT_BADACCESS)))) |
1da177e4 LT |
356 | return 0; |
357 | ||
87134102 JW |
358 | /* |
359 | * If we are in kernel mode at this point, we | |
360 | * have no context to handle this fault with. | |
361 | */ | |
362 | if (!user_mode(regs)) | |
363 | goto no_context; | |
364 | ||
b42c6344 RK |
365 | if (fault & VM_FAULT_OOM) { |
366 | /* | |
367 | * We ran out of memory, call the OOM killer, and return to | |
368 | * userspace (which will retry the fault, or kill us if we | |
369 | * got oom-killed) | |
370 | */ | |
371 | pagefault_out_of_memory(); | |
372 | return 0; | |
373 | } | |
374 | ||
83c54070 | 375 | if (fault & VM_FAULT_SIGBUS) { |
2d137c24 | 376 | /* |
377 | * We had some memory, but were unable to | |
378 | * successfully fix up this page fault. | |
379 | */ | |
380 | sig = SIGBUS; | |
381 | code = BUS_ADRERR; | |
83c54070 | 382 | } else { |
2d137c24 | 383 | /* |
384 | * Something tried to access memory that | |
385 | * isn't in our memory map.. | |
386 | */ | |
387 | sig = SIGSEGV; | |
388 | code = fault == VM_FAULT_BADACCESS ? | |
389 | SEGV_ACCERR : SEGV_MAPERR; | |
1da177e4 | 390 | } |
1da177e4 | 391 | |
2d137c24 | 392 | __do_user_fault(tsk, addr, fsr, sig, code, regs); |
393 | return 0; | |
1da177e4 LT |
394 | |
395 | no_context: | |
396 | __do_kernel_fault(mm, addr, fsr, regs); | |
397 | return 0; | |
398 | } | |
09529f7a CM |
399 | #else /* CONFIG_MMU */ |
400 | static int | |
401 | do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs) | |
402 | { | |
403 | return 0; | |
404 | } | |
405 | #endif /* CONFIG_MMU */ | |
1da177e4 LT |
406 | |
407 | /* | |
408 | * First Level Translation Fault Handler | |
409 | * | |
410 | * We enter here because the first level page table doesn't contain | |
411 | * a valid entry for the address. | |
412 | * | |
413 | * If the address is in kernel space (>= TASK_SIZE), then we are | |
414 | * probably faulting in the vmalloc() area. | |
415 | * | |
416 | * If the init_task's first level page tables contains the relevant | |
417 | * entry, we copy the it to this task. If not, we send the process | |
418 | * a signal, fixup the exception, or oops the kernel. | |
419 | * | |
420 | * NOTE! We MUST NOT take any locks for this case. We may be in an | |
421 | * interrupt or a critical region, and should only copy the information | |
422 | * from the master page table, nothing more. | |
423 | */ | |
09529f7a | 424 | #ifdef CONFIG_MMU |
785d3cd2 | 425 | static int __kprobes |
1da177e4 LT |
426 | do_translation_fault(unsigned long addr, unsigned int fsr, |
427 | struct pt_regs *regs) | |
428 | { | |
1da177e4 LT |
429 | unsigned int index; |
430 | pgd_t *pgd, *pgd_k; | |
516295e5 | 431 | pud_t *pud, *pud_k; |
1da177e4 LT |
432 | pmd_t *pmd, *pmd_k; |
433 | ||
434 | if (addr < TASK_SIZE) | |
435 | return do_page_fault(addr, fsr, regs); | |
436 | ||
5e27fb78 A |
437 | if (user_mode(regs)) |
438 | goto bad_area; | |
439 | ||
1da177e4 LT |
440 | index = pgd_index(addr); |
441 | ||
1da177e4 LT |
442 | pgd = cpu_get_pgd() + index; |
443 | pgd_k = init_mm.pgd + index; | |
444 | ||
445 | if (pgd_none(*pgd_k)) | |
446 | goto bad_area; | |
1da177e4 LT |
447 | if (!pgd_present(*pgd)) |
448 | set_pgd(pgd, *pgd_k); | |
449 | ||
516295e5 RK |
450 | pud = pud_offset(pgd, addr); |
451 | pud_k = pud_offset(pgd_k, addr); | |
452 | ||
453 | if (pud_none(*pud_k)) | |
454 | goto bad_area; | |
455 | if (!pud_present(*pud)) | |
456 | set_pud(pud, *pud_k); | |
457 | ||
458 | pmd = pmd_offset(pud, addr); | |
459 | pmd_k = pmd_offset(pud_k, addr); | |
1da177e4 | 460 | |
f7b8156d CM |
461 | #ifdef CONFIG_ARM_LPAE |
462 | /* | |
463 | * Only one hardware entry per PMD with LPAE. | |
464 | */ | |
465 | index = 0; | |
466 | #else | |
33a9c41b KS |
467 | /* |
468 | * On ARM one Linux PGD entry contains two hardware entries (see page | |
469 | * tables layout in pgtable.h). We normally guarantee that we always | |
470 | * fill both L1 entries. But create_mapping() doesn't follow the rule. | |
471 | * It can create inidividual L1 entries, so here we have to call | |
472 | * pmd_none() check for the entry really corresponded to address, not | |
473 | * for the first of pair. | |
474 | */ | |
475 | index = (addr >> SECTION_SHIFT) & 1; | |
f7b8156d | 476 | #endif |
33a9c41b | 477 | if (pmd_none(pmd_k[index])) |
1da177e4 LT |
478 | goto bad_area; |
479 | ||
480 | copy_pmd(pmd, pmd_k); | |
481 | return 0; | |
482 | ||
483 | bad_area: | |
e5beac37 | 484 | do_bad_area(addr, fsr, regs); |
1da177e4 LT |
485 | return 0; |
486 | } | |
09529f7a CM |
487 | #else /* CONFIG_MMU */ |
488 | static int | |
489 | do_translation_fault(unsigned long addr, unsigned int fsr, | |
490 | struct pt_regs *regs) | |
491 | { | |
492 | return 0; | |
493 | } | |
494 | #endif /* CONFIG_MMU */ | |
1da177e4 LT |
495 | |
496 | /* | |
497 | * Some section permission faults need to be handled gracefully. | |
498 | * They can happen due to a __{get,put}_user during an oops. | |
499 | */ | |
809e660f | 500 | #ifndef CONFIG_ARM_LPAE |
1da177e4 LT |
501 | static int |
502 | do_sect_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs) | |
503 | { | |
e5beac37 | 504 | do_bad_area(addr, fsr, regs); |
1da177e4 LT |
505 | return 0; |
506 | } | |
809e660f | 507 | #endif /* CONFIG_ARM_LPAE */ |
1da177e4 LT |
508 | |
509 | /* | |
510 | * This abort handler always returns "fault". | |
511 | */ | |
512 | static int | |
513 | do_bad(unsigned long addr, unsigned int fsr, struct pt_regs *regs) | |
514 | { | |
515 | return 1; | |
516 | } | |
517 | ||
136848d4 | 518 | struct fsr_info { |
1da177e4 LT |
519 | int (*fn)(unsigned long addr, unsigned int fsr, struct pt_regs *regs); |
520 | int sig; | |
cfb0810e | 521 | int code; |
1da177e4 | 522 | const char *name; |
1da177e4 LT |
523 | }; |
524 | ||
136848d4 | 525 | /* FSR definition */ |
f7b8156d CM |
526 | #ifdef CONFIG_ARM_LPAE |
527 | #include "fsr-3level.c" | |
528 | #else | |
136848d4 | 529 | #include "fsr-2level.c" |
f7b8156d | 530 | #endif |
136848d4 | 531 | |
1da177e4 LT |
532 | void __init |
533 | hook_fault_code(int nr, int (*fn)(unsigned long, unsigned int, struct pt_regs *), | |
6338a6aa | 534 | int sig, int code, const char *name) |
1da177e4 | 535 | { |
6338a6aa KS |
536 | if (nr < 0 || nr >= ARRAY_SIZE(fsr_info)) |
537 | BUG(); | |
538 | ||
539 | fsr_info[nr].fn = fn; | |
540 | fsr_info[nr].sig = sig; | |
541 | fsr_info[nr].code = code; | |
542 | fsr_info[nr].name = name; | |
1da177e4 LT |
543 | } |
544 | ||
545 | /* | |
546 | * Dispatch a data abort to the relevant handler. | |
547 | */ | |
7ab3f8d5 | 548 | asmlinkage void __exception |
1da177e4 LT |
549 | do_DataAbort(unsigned long addr, unsigned int fsr, struct pt_regs *regs) |
550 | { | |
c88d6aa7 | 551 | const struct fsr_info *inf = fsr_info + fsr_fs(fsr); |
cfb0810e | 552 | struct siginfo info; |
1da177e4 | 553 | |
df297bf6 | 554 | if (!inf->fn(addr, fsr & ~FSR_LNX_PF, regs)) |
1da177e4 LT |
555 | return; |
556 | ||
4ed89f22 | 557 | pr_alert("Unhandled fault: %s (0x%03x) at 0x%08lx\n", |
1da177e4 | 558 | inf->name, fsr, addr); |
6d021b72 | 559 | show_pte(current->mm, addr); |
cfb0810e RK |
560 | |
561 | info.si_signo = inf->sig; | |
562 | info.si_errno = 0; | |
563 | info.si_code = inf->code; | |
564 | info.si_addr = (void __user *)addr; | |
1eeb66a1 | 565 | arm_notify_die("", regs, &info, fsr, 0); |
1da177e4 LT |
566 | } |
567 | ||
3a4b5dca WD |
568 | void __init |
569 | hook_ifault_code(int nr, int (*fn)(unsigned long, unsigned int, struct pt_regs *), | |
570 | int sig, int code, const char *name) | |
571 | { | |
572 | if (nr < 0 || nr >= ARRAY_SIZE(ifsr_info)) | |
573 | BUG(); | |
574 | ||
575 | ifsr_info[nr].fn = fn; | |
576 | ifsr_info[nr].sig = sig; | |
577 | ifsr_info[nr].code = code; | |
578 | ifsr_info[nr].name = name; | |
579 | } | |
580 | ||
7ab3f8d5 | 581 | asmlinkage void __exception |
4fb28474 | 582 | do_PrefetchAbort(unsigned long addr, unsigned int ifsr, struct pt_regs *regs) |
1da177e4 | 583 | { |
d25ef8b8 KS |
584 | const struct fsr_info *inf = ifsr_info + fsr_fs(ifsr); |
585 | struct siginfo info; | |
586 | ||
587 | if (!inf->fn(addr, ifsr | FSR_LNX_PF, regs)) | |
588 | return; | |
589 | ||
4ed89f22 | 590 | pr_alert("Unhandled prefetch abort: %s (0x%03x) at 0x%08lx\n", |
d25ef8b8 KS |
591 | inf->name, ifsr, addr); |
592 | ||
593 | info.si_signo = inf->sig; | |
594 | info.si_errno = 0; | |
595 | info.si_code = inf->code; | |
596 | info.si_addr = (void __user *)addr; | |
597 | arm_notify_die("", regs, &info, ifsr, 0); | |
1da177e4 LT |
598 | } |
599 | ||
9254970c LS |
600 | /* |
601 | * Abort handler to be used only during first unmasking of asynchronous aborts | |
602 | * on the boot CPU. This makes sure that the machine will not die if the | |
603 | * firmware/bootloader left an imprecise abort pending for us to trip over. | |
604 | */ | |
605 | static int __init early_abort_handler(unsigned long addr, unsigned int fsr, | |
606 | struct pt_regs *regs) | |
607 | { | |
608 | pr_warn("Hit pending asynchronous external abort (FSR=0x%08x) during " | |
609 | "first unmask, this is most likely caused by a " | |
610 | "firmware/bootloader bug.\n", fsr); | |
611 | ||
612 | return 0; | |
613 | } | |
614 | ||
615 | void __init early_abt_enable(void) | |
616 | { | |
97a98ae5 | 617 | fsr_info[FSR_FS_AEA].fn = early_abort_handler; |
9254970c | 618 | local_abt_enable(); |
97a98ae5 | 619 | fsr_info[FSR_FS_AEA].fn = do_bad; |
9254970c LS |
620 | } |
621 | ||
f7b8156d | 622 | #ifndef CONFIG_ARM_LPAE |
993bf4ec KS |
623 | static int __init exceptions_init(void) |
624 | { | |
625 | if (cpu_architecture() >= CPU_ARCH_ARMv6) { | |
626 | hook_fault_code(4, do_translation_fault, SIGSEGV, SEGV_MAPERR, | |
627 | "I-cache maintenance fault"); | |
628 | } | |
629 | ||
b8ab5397 KS |
630 | if (cpu_architecture() >= CPU_ARCH_ARMv7) { |
631 | /* | |
632 | * TODO: Access flag faults introduced in ARMv6K. | |
633 | * Runtime check for 'K' extension is needed | |
634 | */ | |
635 | hook_fault_code(3, do_bad, SIGSEGV, SEGV_MAPERR, | |
636 | "section access flag fault"); | |
637 | hook_fault_code(6, do_bad, SIGSEGV, SEGV_MAPERR, | |
638 | "section access flag fault"); | |
639 | } | |
640 | ||
993bf4ec KS |
641 | return 0; |
642 | } | |
643 | ||
644 | arch_initcall(exceptions_init); | |
f7b8156d | 645 | #endif |