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1d18c47c CM |
1 | /* |
2 | * Based on arch/arm/mm/fault.c | |
3 | * | |
4 | * Copyright (C) 1995 Linus Torvalds | |
5 | * Copyright (C) 1995-2004 Russell King | |
6 | * Copyright (C) 2012 ARM Ltd. | |
7 | * | |
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. | |
11 | * | |
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. | |
16 | * | |
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/>. | |
19 | */ | |
20 | ||
0edfa839 | 21 | #include <linux/extable.h> |
1d18c47c CM |
22 | #include <linux/signal.h> |
23 | #include <linux/mm.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> | |
3f07c014 | 29 | #include <linux/sched/signal.h> |
b17b0153 | 30 | #include <linux/sched/debug.h> |
1d18c47c CM |
31 | #include <linux/highmem.h> |
32 | #include <linux/perf_event.h> | |
7209c868 | 33 | #include <linux/preempt.h> |
1d18c47c | 34 | |
7209c868 | 35 | #include <asm/bug.h> |
338d4f49 | 36 | #include <asm/cpufeature.h> |
1d18c47c CM |
37 | #include <asm/exception.h> |
38 | #include <asm/debug-monitors.h> | |
9141300a | 39 | #include <asm/esr.h> |
338d4f49 | 40 | #include <asm/sysreg.h> |
1d18c47c CM |
41 | #include <asm/system_misc.h> |
42 | #include <asm/pgtable.h> | |
43 | #include <asm/tlbflush.h> | |
44 | ||
09a6adf5 VK |
45 | struct fault_info { |
46 | int (*fn)(unsigned long addr, unsigned int esr, | |
47 | struct pt_regs *regs); | |
48 | int sig; | |
49 | int code; | |
50 | const char *name; | |
51 | }; | |
52 | ||
53 | static const struct fault_info fault_info[]; | |
54 | ||
55 | static inline const struct fault_info *esr_to_fault_info(unsigned int esr) | |
56 | { | |
57 | return fault_info + (esr & 63); | |
58 | } | |
3495386b | 59 | |
2dd0e8d2 SP |
60 | #ifdef CONFIG_KPROBES |
61 | static inline int notify_page_fault(struct pt_regs *regs, unsigned int esr) | |
62 | { | |
63 | int ret = 0; | |
64 | ||
65 | /* kprobe_running() needs smp_processor_id() */ | |
66 | if (!user_mode(regs)) { | |
67 | preempt_disable(); | |
68 | if (kprobe_running() && kprobe_fault_handler(regs, esr)) | |
69 | ret = 1; | |
70 | preempt_enable(); | |
71 | } | |
72 | ||
73 | return ret; | |
74 | } | |
75 | #else | |
76 | static inline int notify_page_fault(struct pt_regs *regs, unsigned int esr) | |
77 | { | |
78 | return 0; | |
79 | } | |
80 | #endif | |
81 | ||
1d18c47c CM |
82 | /* |
83 | * Dump out the page tables associated with 'addr' in mm 'mm'. | |
84 | */ | |
85 | void show_pte(struct mm_struct *mm, unsigned long addr) | |
86 | { | |
87 | pgd_t *pgd; | |
88 | ||
89 | if (!mm) | |
90 | mm = &init_mm; | |
91 | ||
92 | pr_alert("pgd = %p\n", mm->pgd); | |
93 | pgd = pgd_offset(mm, addr); | |
94 | pr_alert("[%08lx] *pgd=%016llx", addr, pgd_val(*pgd)); | |
95 | ||
96 | do { | |
97 | pud_t *pud; | |
98 | pmd_t *pmd; | |
99 | pte_t *pte; | |
100 | ||
4339e3f3 | 101 | if (pgd_none(*pgd) || pgd_bad(*pgd)) |
1d18c47c CM |
102 | break; |
103 | ||
104 | pud = pud_offset(pgd, addr); | |
6ef4fb38 | 105 | pr_cont(", *pud=%016llx", pud_val(*pud)); |
4339e3f3 | 106 | if (pud_none(*pud) || pud_bad(*pud)) |
1d18c47c CM |
107 | break; |
108 | ||
109 | pmd = pmd_offset(pud, addr); | |
6ef4fb38 | 110 | pr_cont(", *pmd=%016llx", pmd_val(*pmd)); |
4339e3f3 | 111 | if (pmd_none(*pmd) || pmd_bad(*pmd)) |
1d18c47c CM |
112 | break; |
113 | ||
114 | pte = pte_offset_map(pmd, addr); | |
6ef4fb38 | 115 | pr_cont(", *pte=%016llx", pte_val(*pte)); |
1d18c47c CM |
116 | pte_unmap(pte); |
117 | } while(0); | |
118 | ||
6ef4fb38 | 119 | pr_cont("\n"); |
1d18c47c CM |
120 | } |
121 | ||
66dbd6e6 CM |
122 | #ifdef CONFIG_ARM64_HW_AFDBM |
123 | /* | |
124 | * This function sets the access flags (dirty, accessed), as well as write | |
125 | * permission, and only to a more permissive setting. | |
126 | * | |
127 | * It needs to cope with hardware update of the accessed/dirty state by other | |
128 | * agents in the system and can safely skip the __sync_icache_dcache() call as, | |
129 | * like set_pte_at(), the PTE is never changed from no-exec to exec here. | |
130 | * | |
131 | * Returns whether or not the PTE actually changed. | |
132 | */ | |
133 | int ptep_set_access_flags(struct vm_area_struct *vma, | |
134 | unsigned long address, pte_t *ptep, | |
135 | pte_t entry, int dirty) | |
136 | { | |
137 | pteval_t old_pteval; | |
138 | unsigned int tmp; | |
139 | ||
140 | if (pte_same(*ptep, entry)) | |
141 | return 0; | |
142 | ||
143 | /* only preserve the access flags and write permission */ | |
144 | pte_val(entry) &= PTE_AF | PTE_WRITE | PTE_DIRTY; | |
145 | ||
146 | /* | |
147 | * PTE_RDONLY is cleared by default in the asm below, so set it in | |
148 | * back if necessary (read-only or clean PTE). | |
149 | */ | |
0106d456 | 150 | if (!pte_write(entry) || !pte_sw_dirty(entry)) |
66dbd6e6 CM |
151 | pte_val(entry) |= PTE_RDONLY; |
152 | ||
153 | /* | |
154 | * Setting the flags must be done atomically to avoid racing with the | |
155 | * hardware update of the access/dirty state. | |
156 | */ | |
157 | asm volatile("// ptep_set_access_flags\n" | |
158 | " prfm pstl1strm, %2\n" | |
159 | "1: ldxr %0, %2\n" | |
160 | " and %0, %0, %3 // clear PTE_RDONLY\n" | |
161 | " orr %0, %0, %4 // set flags\n" | |
162 | " stxr %w1, %0, %2\n" | |
163 | " cbnz %w1, 1b\n" | |
164 | : "=&r" (old_pteval), "=&r" (tmp), "+Q" (pte_val(*ptep)) | |
165 | : "L" (~PTE_RDONLY), "r" (pte_val(entry))); | |
166 | ||
167 | flush_tlb_fix_spurious_fault(vma, address); | |
168 | return 1; | |
169 | } | |
170 | #endif | |
171 | ||
9adeb8e7 LA |
172 | static bool is_el1_instruction_abort(unsigned int esr) |
173 | { | |
174 | return ESR_ELx_EC(esr) == ESR_ELx_EC_IABT_CUR; | |
175 | } | |
176 | ||
1d18c47c CM |
177 | /* |
178 | * The kernel tried to access some page that wasn't present. | |
179 | */ | |
180 | static void __do_kernel_fault(struct mm_struct *mm, unsigned long addr, | |
181 | unsigned int esr, struct pt_regs *regs) | |
182 | { | |
183 | /* | |
184 | * Are we prepared to handle this kernel fault? | |
9adeb8e7 | 185 | * We are almost certainly not prepared to handle instruction faults. |
1d18c47c | 186 | */ |
9adeb8e7 | 187 | if (!is_el1_instruction_abort(esr) && fixup_exception(regs)) |
1d18c47c CM |
188 | return; |
189 | ||
190 | /* | |
191 | * No handler, we'll have to terminate things with extreme prejudice. | |
192 | */ | |
193 | bust_spinlocks(1); | |
194 | pr_alert("Unable to handle kernel %s at virtual address %08lx\n", | |
195 | (addr < PAGE_SIZE) ? "NULL pointer dereference" : | |
196 | "paging request", addr); | |
197 | ||
198 | show_pte(mm, addr); | |
199 | die("Oops", regs, esr); | |
200 | bust_spinlocks(0); | |
201 | do_exit(SIGKILL); | |
202 | } | |
203 | ||
204 | /* | |
205 | * Something tried to access memory that isn't in our memory map. User mode | |
206 | * accesses just cause a SIGSEGV | |
207 | */ | |
208 | static void __do_user_fault(struct task_struct *tsk, unsigned long addr, | |
209 | unsigned int esr, unsigned int sig, int code, | |
210 | struct pt_regs *regs) | |
211 | { | |
212 | struct siginfo si; | |
09a6adf5 | 213 | const struct fault_info *inf; |
1d18c47c | 214 | |
f871d268 | 215 | if (unhandled_signal(tsk, sig) && show_unhandled_signals_ratelimited()) { |
09a6adf5 | 216 | inf = esr_to_fault_info(esr); |
3495386b | 217 | pr_info("%s[%d]: unhandled %s (%d) at 0x%08lx, esr 0x%03x\n", |
09a6adf5 | 218 | tsk->comm, task_pid_nr(tsk), inf->name, sig, |
3495386b | 219 | addr, esr); |
1d18c47c CM |
220 | show_pte(tsk->mm, addr); |
221 | show_regs(regs); | |
222 | } | |
223 | ||
224 | tsk->thread.fault_address = addr; | |
9141300a | 225 | tsk->thread.fault_code = esr; |
1d18c47c CM |
226 | si.si_signo = sig; |
227 | si.si_errno = 0; | |
228 | si.si_code = code; | |
229 | si.si_addr = (void __user *)addr; | |
230 | force_sig_info(sig, &si, tsk); | |
231 | } | |
232 | ||
59f67e16 | 233 | static void do_bad_area(unsigned long addr, unsigned int esr, struct pt_regs *regs) |
1d18c47c CM |
234 | { |
235 | struct task_struct *tsk = current; | |
236 | struct mm_struct *mm = tsk->active_mm; | |
09a6adf5 | 237 | const struct fault_info *inf; |
1d18c47c CM |
238 | |
239 | /* | |
240 | * If we are in kernel mode at this point, we have no context to | |
241 | * handle this fault with. | |
242 | */ | |
09a6adf5 VK |
243 | if (user_mode(regs)) { |
244 | inf = esr_to_fault_info(esr); | |
245 | __do_user_fault(tsk, addr, esr, inf->sig, inf->code, regs); | |
246 | } else | |
1d18c47c CM |
247 | __do_kernel_fault(mm, addr, esr, regs); |
248 | } | |
249 | ||
250 | #define VM_FAULT_BADMAP 0x010000 | |
251 | #define VM_FAULT_BADACCESS 0x020000 | |
252 | ||
1d18c47c | 253 | static int __do_page_fault(struct mm_struct *mm, unsigned long addr, |
db6f4106 | 254 | unsigned int mm_flags, unsigned long vm_flags, |
1d18c47c CM |
255 | struct task_struct *tsk) |
256 | { | |
257 | struct vm_area_struct *vma; | |
258 | int fault; | |
259 | ||
260 | vma = find_vma(mm, addr); | |
261 | fault = VM_FAULT_BADMAP; | |
262 | if (unlikely(!vma)) | |
263 | goto out; | |
264 | if (unlikely(vma->vm_start > addr)) | |
265 | goto check_stack; | |
266 | ||
267 | /* | |
268 | * Ok, we have a good vm_area for this memory access, so we can handle | |
269 | * it. | |
270 | */ | |
271 | good_area: | |
db6f4106 WD |
272 | /* |
273 | * Check that the permissions on the VMA allow for the fault which | |
cab15ce6 | 274 | * occurred. |
db6f4106 WD |
275 | */ |
276 | if (!(vma->vm_flags & vm_flags)) { | |
1d18c47c CM |
277 | fault = VM_FAULT_BADACCESS; |
278 | goto out; | |
279 | } | |
280 | ||
dcddffd4 | 281 | return handle_mm_fault(vma, addr & PAGE_MASK, mm_flags); |
1d18c47c CM |
282 | |
283 | check_stack: | |
284 | if (vma->vm_flags & VM_GROWSDOWN && !expand_stack(vma, addr)) | |
285 | goto good_area; | |
286 | out: | |
287 | return fault; | |
288 | } | |
289 | ||
78688963 | 290 | static inline bool is_permission_fault(unsigned int esr, struct pt_regs *regs) |
57f4959b | 291 | { |
275f344b | 292 | unsigned int ec = ESR_ELx_EC(esr); |
57f4959b JM |
293 | unsigned int fsc_type = esr & ESR_ELx_FSC_TYPE; |
294 | ||
78688963 CM |
295 | if (ec != ESR_ELx_EC_DABT_CUR && ec != ESR_ELx_EC_IABT_CUR) |
296 | return false; | |
297 | ||
298 | if (system_uses_ttbr0_pan()) | |
299 | return fsc_type == ESR_ELx_FSC_FAULT && | |
300 | (regs->pstate & PSR_PAN_BIT); | |
301 | else | |
302 | return fsc_type == ESR_ELx_FSC_PERM; | |
57f4959b JM |
303 | } |
304 | ||
541ec870 MR |
305 | static bool is_el0_instruction_abort(unsigned int esr) |
306 | { | |
307 | return ESR_ELx_EC(esr) == ESR_ELx_EC_IABT_LOW; | |
308 | } | |
309 | ||
1d18c47c CM |
310 | static int __kprobes do_page_fault(unsigned long addr, unsigned int esr, |
311 | struct pt_regs *regs) | |
312 | { | |
313 | struct task_struct *tsk; | |
314 | struct mm_struct *mm; | |
315 | int fault, sig, code; | |
cab15ce6 | 316 | unsigned long vm_flags = VM_READ | VM_WRITE; |
db6f4106 WD |
317 | unsigned int mm_flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE; |
318 | ||
2dd0e8d2 SP |
319 | if (notify_page_fault(regs, esr)) |
320 | return 0; | |
321 | ||
1d18c47c CM |
322 | tsk = current; |
323 | mm = tsk->mm; | |
324 | ||
1d18c47c CM |
325 | /* |
326 | * If we're in an interrupt or have no user context, we must not take | |
327 | * the fault. | |
328 | */ | |
70ffdb93 | 329 | if (faulthandler_disabled() || !mm) |
1d18c47c CM |
330 | goto no_context; |
331 | ||
759496ba JW |
332 | if (user_mode(regs)) |
333 | mm_flags |= FAULT_FLAG_USER; | |
334 | ||
541ec870 | 335 | if (is_el0_instruction_abort(esr)) { |
759496ba | 336 | vm_flags = VM_EXEC; |
aed40e01 | 337 | } else if ((esr & ESR_ELx_WNR) && !(esr & ESR_ELx_CM)) { |
759496ba JW |
338 | vm_flags = VM_WRITE; |
339 | mm_flags |= FAULT_FLAG_WRITE; | |
340 | } | |
341 | ||
78688963 | 342 | if (addr < USER_DS && is_permission_fault(esr, regs)) { |
e19a6ee2 JM |
343 | /* regs->orig_addr_limit may be 0 if we entered from EL0 */ |
344 | if (regs->orig_addr_limit == KERNEL_DS) | |
70c8abc2 | 345 | die("Accessing user space memory with fs=KERNEL_DS", regs, esr); |
70544196 | 346 | |
9adeb8e7 LA |
347 | if (is_el1_instruction_abort(esr)) |
348 | die("Attempting to execute userspace memory", regs, esr); | |
349 | ||
57f4959b | 350 | if (!search_exception_tables(regs->pc)) |
70c8abc2 | 351 | die("Accessing user space memory outside uaccess.h routines", regs, esr); |
57f4959b | 352 | } |
338d4f49 | 353 | |
1d18c47c CM |
354 | /* |
355 | * As per x86, we may deadlock here. However, since the kernel only | |
356 | * validly references user space from well defined areas of the code, | |
357 | * we can bug out early if this is from code which shouldn't. | |
358 | */ | |
359 | if (!down_read_trylock(&mm->mmap_sem)) { | |
360 | if (!user_mode(regs) && !search_exception_tables(regs->pc)) | |
361 | goto no_context; | |
362 | retry: | |
363 | down_read(&mm->mmap_sem); | |
364 | } else { | |
365 | /* | |
366 | * The above down_read_trylock() might have succeeded in which | |
367 | * case, we'll have missed the might_sleep() from down_read(). | |
368 | */ | |
369 | might_sleep(); | |
370 | #ifdef CONFIG_DEBUG_VM | |
371 | if (!user_mode(regs) && !search_exception_tables(regs->pc)) | |
372 | goto no_context; | |
373 | #endif | |
374 | } | |
375 | ||
db6f4106 | 376 | fault = __do_page_fault(mm, addr, mm_flags, vm_flags, tsk); |
1d18c47c CM |
377 | |
378 | /* | |
379 | * If we need to retry but a fatal signal is pending, handle the | |
380 | * signal first. We do not need to release the mmap_sem because it | |
381 | * would already be released in __lock_page_or_retry in mm/filemap.c. | |
382 | */ | |
383 | if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current)) | |
384 | return 0; | |
385 | ||
386 | /* | |
387 | * Major/minor page fault accounting is only done on the initial | |
388 | * attempt. If we go through a retry, it is extremely likely that the | |
389 | * page will be found in page cache at that point. | |
390 | */ | |
391 | ||
392 | perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, addr); | |
db6f4106 | 393 | if (mm_flags & FAULT_FLAG_ALLOW_RETRY) { |
1d18c47c CM |
394 | if (fault & VM_FAULT_MAJOR) { |
395 | tsk->maj_flt++; | |
396 | perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1, regs, | |
397 | addr); | |
398 | } else { | |
399 | tsk->min_flt++; | |
400 | perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, 1, regs, | |
401 | addr); | |
402 | } | |
403 | if (fault & VM_FAULT_RETRY) { | |
404 | /* | |
405 | * Clear FAULT_FLAG_ALLOW_RETRY to avoid any risk of | |
406 | * starvation. | |
407 | */ | |
db6f4106 | 408 | mm_flags &= ~FAULT_FLAG_ALLOW_RETRY; |
569ba74a | 409 | mm_flags |= FAULT_FLAG_TRIED; |
1d18c47c CM |
410 | goto retry; |
411 | } | |
412 | } | |
413 | ||
414 | up_read(&mm->mmap_sem); | |
415 | ||
416 | /* | |
0e8fb931 | 417 | * Handle the "normal" case first - VM_FAULT_MAJOR |
1d18c47c CM |
418 | */ |
419 | if (likely(!(fault & (VM_FAULT_ERROR | VM_FAULT_BADMAP | | |
420 | VM_FAULT_BADACCESS)))) | |
421 | return 0; | |
422 | ||
87134102 JW |
423 | /* |
424 | * If we are in kernel mode at this point, we have no context to | |
425 | * handle this fault with. | |
426 | */ | |
427 | if (!user_mode(regs)) | |
428 | goto no_context; | |
429 | ||
1d18c47c CM |
430 | if (fault & VM_FAULT_OOM) { |
431 | /* | |
432 | * We ran out of memory, call the OOM killer, and return to | |
433 | * userspace (which will retry the fault, or kill us if we got | |
434 | * oom-killed). | |
435 | */ | |
436 | pagefault_out_of_memory(); | |
437 | return 0; | |
438 | } | |
439 | ||
1d18c47c CM |
440 | if (fault & VM_FAULT_SIGBUS) { |
441 | /* | |
442 | * We had some memory, but were unable to successfully fix up | |
443 | * this page fault. | |
444 | */ | |
445 | sig = SIGBUS; | |
446 | code = BUS_ADRERR; | |
447 | } else { | |
448 | /* | |
449 | * Something tried to access memory that isn't in our memory | |
450 | * map. | |
451 | */ | |
452 | sig = SIGSEGV; | |
453 | code = fault == VM_FAULT_BADACCESS ? | |
454 | SEGV_ACCERR : SEGV_MAPERR; | |
455 | } | |
456 | ||
457 | __do_user_fault(tsk, addr, esr, sig, code, regs); | |
458 | return 0; | |
459 | ||
460 | no_context: | |
461 | __do_kernel_fault(mm, addr, esr, regs); | |
462 | return 0; | |
463 | } | |
464 | ||
465 | /* | |
466 | * First Level Translation Fault Handler | |
467 | * | |
468 | * We enter here because the first level page table doesn't contain a valid | |
469 | * entry for the address. | |
470 | * | |
471 | * If the address is in kernel space (>= TASK_SIZE), then we are probably | |
472 | * faulting in the vmalloc() area. | |
473 | * | |
474 | * If the init_task's first level page tables contains the relevant entry, we | |
475 | * copy the it to this task. If not, we send the process a signal, fixup the | |
476 | * exception, or oops the kernel. | |
477 | * | |
478 | * NOTE! We MUST NOT take any locks for this case. We may be in an interrupt | |
479 | * or a critical region, and should only copy the information from the master | |
480 | * page table, nothing more. | |
481 | */ | |
482 | static int __kprobes do_translation_fault(unsigned long addr, | |
483 | unsigned int esr, | |
484 | struct pt_regs *regs) | |
485 | { | |
486 | if (addr < TASK_SIZE) | |
487 | return do_page_fault(addr, esr, regs); | |
488 | ||
489 | do_bad_area(addr, esr, regs); | |
490 | return 0; | |
491 | } | |
492 | ||
52d7523d EL |
493 | static int do_alignment_fault(unsigned long addr, unsigned int esr, |
494 | struct pt_regs *regs) | |
495 | { | |
496 | do_bad_area(addr, esr, regs); | |
497 | return 0; | |
498 | } | |
499 | ||
1d18c47c CM |
500 | /* |
501 | * This abort handler always returns "fault". | |
502 | */ | |
503 | static int do_bad(unsigned long addr, unsigned int esr, struct pt_regs *regs) | |
504 | { | |
505 | return 1; | |
506 | } | |
507 | ||
09a6adf5 | 508 | static const struct fault_info fault_info[] = { |
1d18c47c CM |
509 | { do_bad, SIGBUS, 0, "ttbr address size fault" }, |
510 | { do_bad, SIGBUS, 0, "level 1 address size fault" }, | |
511 | { do_bad, SIGBUS, 0, "level 2 address size fault" }, | |
512 | { do_bad, SIGBUS, 0, "level 3 address size fault" }, | |
7f73f7ae | 513 | { do_translation_fault, SIGSEGV, SEGV_MAPERR, "level 0 translation fault" }, |
1d18c47c CM |
514 | { do_translation_fault, SIGSEGV, SEGV_MAPERR, "level 1 translation fault" }, |
515 | { do_translation_fault, SIGSEGV, SEGV_MAPERR, "level 2 translation fault" }, | |
516 | { do_page_fault, SIGSEGV, SEGV_MAPERR, "level 3 translation fault" }, | |
c03784ee | 517 | { do_bad, SIGBUS, 0, "unknown 8" }, |
084bd298 SC |
518 | { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 1 access flag fault" }, |
519 | { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 2 access flag fault" }, | |
1d18c47c | 520 | { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 3 access flag fault" }, |
c03784ee | 521 | { do_bad, SIGBUS, 0, "unknown 12" }, |
084bd298 SC |
522 | { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 1 permission fault" }, |
523 | { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 2 permission fault" }, | |
1d18c47c CM |
524 | { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 3 permission fault" }, |
525 | { do_bad, SIGBUS, 0, "synchronous external abort" }, | |
c03784ee | 526 | { do_bad, SIGBUS, 0, "unknown 17" }, |
1d18c47c CM |
527 | { do_bad, SIGBUS, 0, "unknown 18" }, |
528 | { do_bad, SIGBUS, 0, "unknown 19" }, | |
a8ada146 CM |
529 | { do_bad, SIGBUS, 0, "synchronous external abort (translation table walk)" }, |
530 | { do_bad, SIGBUS, 0, "synchronous external abort (translation table walk)" }, | |
531 | { do_bad, SIGBUS, 0, "synchronous external abort (translation table walk)" }, | |
532 | { do_bad, SIGBUS, 0, "synchronous external abort (translation table walk)" }, | |
1d18c47c | 533 | { do_bad, SIGBUS, 0, "synchronous parity error" }, |
c03784ee | 534 | { do_bad, SIGBUS, 0, "unknown 25" }, |
1d18c47c CM |
535 | { do_bad, SIGBUS, 0, "unknown 26" }, |
536 | { do_bad, SIGBUS, 0, "unknown 27" }, | |
c03784ee MR |
537 | { do_bad, SIGBUS, 0, "synchronous parity error (translation table walk)" }, |
538 | { do_bad, SIGBUS, 0, "synchronous parity error (translation table walk)" }, | |
539 | { do_bad, SIGBUS, 0, "synchronous parity error (translation table walk)" }, | |
540 | { do_bad, SIGBUS, 0, "synchronous parity error (translation table walk)" }, | |
1d18c47c | 541 | { do_bad, SIGBUS, 0, "unknown 32" }, |
52d7523d | 542 | { do_alignment_fault, SIGBUS, BUS_ADRALN, "alignment fault" }, |
c03784ee | 543 | { do_bad, SIGBUS, 0, "unknown 34" }, |
1d18c47c CM |
544 | { do_bad, SIGBUS, 0, "unknown 35" }, |
545 | { do_bad, SIGBUS, 0, "unknown 36" }, | |
546 | { do_bad, SIGBUS, 0, "unknown 37" }, | |
547 | { do_bad, SIGBUS, 0, "unknown 38" }, | |
548 | { do_bad, SIGBUS, 0, "unknown 39" }, | |
549 | { do_bad, SIGBUS, 0, "unknown 40" }, | |
550 | { do_bad, SIGBUS, 0, "unknown 41" }, | |
551 | { do_bad, SIGBUS, 0, "unknown 42" }, | |
552 | { do_bad, SIGBUS, 0, "unknown 43" }, | |
553 | { do_bad, SIGBUS, 0, "unknown 44" }, | |
554 | { do_bad, SIGBUS, 0, "unknown 45" }, | |
555 | { do_bad, SIGBUS, 0, "unknown 46" }, | |
556 | { do_bad, SIGBUS, 0, "unknown 47" }, | |
c03784ee | 557 | { do_bad, SIGBUS, 0, "TLB conflict abort" }, |
1d18c47c CM |
558 | { do_bad, SIGBUS, 0, "unknown 49" }, |
559 | { do_bad, SIGBUS, 0, "unknown 50" }, | |
560 | { do_bad, SIGBUS, 0, "unknown 51" }, | |
561 | { do_bad, SIGBUS, 0, "implementation fault (lockdown abort)" }, | |
c03784ee | 562 | { do_bad, SIGBUS, 0, "implementation fault (unsupported exclusive)" }, |
1d18c47c CM |
563 | { do_bad, SIGBUS, 0, "unknown 54" }, |
564 | { do_bad, SIGBUS, 0, "unknown 55" }, | |
565 | { do_bad, SIGBUS, 0, "unknown 56" }, | |
566 | { do_bad, SIGBUS, 0, "unknown 57" }, | |
c03784ee | 567 | { do_bad, SIGBUS, 0, "unknown 58" }, |
1d18c47c CM |
568 | { do_bad, SIGBUS, 0, "unknown 59" }, |
569 | { do_bad, SIGBUS, 0, "unknown 60" }, | |
c03784ee MR |
570 | { do_bad, SIGBUS, 0, "section domain fault" }, |
571 | { do_bad, SIGBUS, 0, "page domain fault" }, | |
1d18c47c CM |
572 | { do_bad, SIGBUS, 0, "unknown 63" }, |
573 | }; | |
574 | ||
575 | /* | |
576 | * Dispatch a data abort to the relevant handler. | |
577 | */ | |
578 | asmlinkage void __exception do_mem_abort(unsigned long addr, unsigned int esr, | |
579 | struct pt_regs *regs) | |
580 | { | |
09a6adf5 | 581 | const struct fault_info *inf = esr_to_fault_info(esr); |
1d18c47c CM |
582 | struct siginfo info; |
583 | ||
584 | if (!inf->fn(addr, esr, regs)) | |
585 | return; | |
586 | ||
587 | pr_alert("Unhandled fault: %s (0x%08x) at 0x%016lx\n", | |
588 | inf->name, esr, addr); | |
589 | ||
590 | info.si_signo = inf->sig; | |
591 | info.si_errno = 0; | |
592 | info.si_code = inf->code; | |
593 | info.si_addr = (void __user *)addr; | |
594 | arm64_notify_die("", regs, &info, esr); | |
595 | } | |
596 | ||
597 | /* | |
598 | * Handle stack alignment exceptions. | |
599 | */ | |
600 | asmlinkage void __exception do_sp_pc_abort(unsigned long addr, | |
601 | unsigned int esr, | |
602 | struct pt_regs *regs) | |
603 | { | |
604 | struct siginfo info; | |
9e793ab8 VM |
605 | struct task_struct *tsk = current; |
606 | ||
607 | if (show_unhandled_signals && unhandled_signal(tsk, SIGBUS)) | |
608 | pr_info_ratelimited("%s[%d]: %s exception: pc=%p sp=%p\n", | |
609 | tsk->comm, task_pid_nr(tsk), | |
610 | esr_get_class_string(esr), (void *)regs->pc, | |
611 | (void *)regs->sp); | |
1d18c47c CM |
612 | |
613 | info.si_signo = SIGBUS; | |
614 | info.si_errno = 0; | |
615 | info.si_code = BUS_ADRALN; | |
616 | info.si_addr = (void __user *)addr; | |
9e793ab8 | 617 | arm64_notify_die("Oops - SP/PC alignment exception", regs, &info, esr); |
1d18c47c CM |
618 | } |
619 | ||
9fb7410f DM |
620 | int __init early_brk64(unsigned long addr, unsigned int esr, |
621 | struct pt_regs *regs); | |
622 | ||
623 | /* | |
624 | * __refdata because early_brk64 is __init, but the reference to it is | |
625 | * clobbered at arch_initcall time. | |
626 | * See traps.c and debug-monitors.c:debug_traps_init(). | |
627 | */ | |
628 | static struct fault_info __refdata debug_fault_info[] = { | |
1d18c47c CM |
629 | { do_bad, SIGTRAP, TRAP_HWBKPT, "hardware breakpoint" }, |
630 | { do_bad, SIGTRAP, TRAP_HWBKPT, "hardware single-step" }, | |
631 | { do_bad, SIGTRAP, TRAP_HWBKPT, "hardware watchpoint" }, | |
632 | { do_bad, SIGBUS, 0, "unknown 3" }, | |
633 | { do_bad, SIGTRAP, TRAP_BRKPT, "aarch32 BKPT" }, | |
634 | { do_bad, SIGTRAP, 0, "aarch32 vector catch" }, | |
9fb7410f | 635 | { early_brk64, SIGTRAP, TRAP_BRKPT, "aarch64 BRK" }, |
1d18c47c CM |
636 | { do_bad, SIGBUS, 0, "unknown 7" }, |
637 | }; | |
638 | ||
639 | void __init hook_debug_fault_code(int nr, | |
640 | int (*fn)(unsigned long, unsigned int, struct pt_regs *), | |
641 | int sig, int code, const char *name) | |
642 | { | |
643 | BUG_ON(nr < 0 || nr >= ARRAY_SIZE(debug_fault_info)); | |
644 | ||
645 | debug_fault_info[nr].fn = fn; | |
646 | debug_fault_info[nr].sig = sig; | |
647 | debug_fault_info[nr].code = code; | |
648 | debug_fault_info[nr].name = name; | |
649 | } | |
650 | ||
651 | asmlinkage int __exception do_debug_exception(unsigned long addr, | |
652 | unsigned int esr, | |
653 | struct pt_regs *regs) | |
654 | { | |
655 | const struct fault_info *inf = debug_fault_info + DBG_ESR_EVT(esr); | |
656 | struct siginfo info; | |
6afedcd2 | 657 | int rv; |
1d18c47c | 658 | |
6afedcd2 JM |
659 | /* |
660 | * Tell lockdep we disabled irqs in entry.S. Do nothing if they were | |
661 | * already disabled to preserve the last enabled/disabled addresses. | |
662 | */ | |
663 | if (interrupts_enabled(regs)) | |
664 | trace_hardirqs_off(); | |
1d18c47c | 665 | |
6afedcd2 JM |
666 | if (!inf->fn(addr, esr, regs)) { |
667 | rv = 1; | |
668 | } else { | |
669 | pr_alert("Unhandled debug exception: %s (0x%08x) at 0x%016lx\n", | |
670 | inf->name, esr, addr); | |
671 | ||
672 | info.si_signo = inf->sig; | |
673 | info.si_errno = 0; | |
674 | info.si_code = inf->code; | |
675 | info.si_addr = (void __user *)addr; | |
676 | arm64_notify_die("", regs, &info, 0); | |
677 | rv = 0; | |
678 | } | |
1d18c47c | 679 | |
6afedcd2 JM |
680 | if (interrupts_enabled(regs)) |
681 | trace_hardirqs_on(); | |
1d18c47c | 682 | |
6afedcd2 | 683 | return rv; |
1d18c47c | 684 | } |
2dd0e8d2 | 685 | NOKPROBE_SYMBOL(do_debug_exception); |
338d4f49 JM |
686 | |
687 | #ifdef CONFIG_ARM64_PAN | |
2a6dcb2b | 688 | int cpu_enable_pan(void *__unused) |
338d4f49 | 689 | { |
7209c868 JM |
690 | /* |
691 | * We modify PSTATE. This won't work from irq context as the PSTATE | |
692 | * is discarded once we return from the exception. | |
693 | */ | |
694 | WARN_ON_ONCE(in_interrupt()); | |
695 | ||
338d4f49 | 696 | config_sctlr_el1(SCTLR_EL1_SPAN, 0); |
7209c868 | 697 | asm(SET_PSTATE_PAN(1)); |
2a6dcb2b | 698 | return 0; |
338d4f49 JM |
699 | } |
700 | #endif /* CONFIG_ARM64_PAN */ |