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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> | |
29 | #include <linux/sched.h> | |
30 | #include <linux/highmem.h> | |
31 | #include <linux/perf_event.h> | |
7209c868 | 32 | #include <linux/preempt.h> |
1d18c47c | 33 | |
7209c868 | 34 | #include <asm/bug.h> |
338d4f49 | 35 | #include <asm/cpufeature.h> |
1d18c47c CM |
36 | #include <asm/exception.h> |
37 | #include <asm/debug-monitors.h> | |
9141300a | 38 | #include <asm/esr.h> |
338d4f49 | 39 | #include <asm/sysreg.h> |
1d18c47c CM |
40 | #include <asm/system_misc.h> |
41 | #include <asm/pgtable.h> | |
42 | #include <asm/tlbflush.h> | |
43 | ||
3495386b CM |
44 | static const char *fault_name(unsigned int esr); |
45 | ||
2dd0e8d2 SP |
46 | #ifdef CONFIG_KPROBES |
47 | static inline int notify_page_fault(struct pt_regs *regs, unsigned int esr) | |
48 | { | |
49 | int ret = 0; | |
50 | ||
51 | /* kprobe_running() needs smp_processor_id() */ | |
52 | if (!user_mode(regs)) { | |
53 | preempt_disable(); | |
54 | if (kprobe_running() && kprobe_fault_handler(regs, esr)) | |
55 | ret = 1; | |
56 | preempt_enable(); | |
57 | } | |
58 | ||
59 | return ret; | |
60 | } | |
61 | #else | |
62 | static inline int notify_page_fault(struct pt_regs *regs, unsigned int esr) | |
63 | { | |
64 | return 0; | |
65 | } | |
66 | #endif | |
67 | ||
1d18c47c CM |
68 | /* |
69 | * Dump out the page tables associated with 'addr' in mm 'mm'. | |
70 | */ | |
71 | void show_pte(struct mm_struct *mm, unsigned long addr) | |
72 | { | |
73 | pgd_t *pgd; | |
74 | ||
75 | if (!mm) | |
76 | mm = &init_mm; | |
77 | ||
78 | pr_alert("pgd = %p\n", mm->pgd); | |
79 | pgd = pgd_offset(mm, addr); | |
80 | pr_alert("[%08lx] *pgd=%016llx", addr, pgd_val(*pgd)); | |
81 | ||
82 | do { | |
83 | pud_t *pud; | |
84 | pmd_t *pmd; | |
85 | pte_t *pte; | |
86 | ||
4339e3f3 | 87 | if (pgd_none(*pgd) || pgd_bad(*pgd)) |
1d18c47c CM |
88 | break; |
89 | ||
90 | pud = pud_offset(pgd, addr); | |
6ef4fb38 | 91 | pr_cont(", *pud=%016llx", pud_val(*pud)); |
4339e3f3 | 92 | if (pud_none(*pud) || pud_bad(*pud)) |
1d18c47c CM |
93 | break; |
94 | ||
95 | pmd = pmd_offset(pud, addr); | |
6ef4fb38 | 96 | pr_cont(", *pmd=%016llx", pmd_val(*pmd)); |
4339e3f3 | 97 | if (pmd_none(*pmd) || pmd_bad(*pmd)) |
1d18c47c CM |
98 | break; |
99 | ||
100 | pte = pte_offset_map(pmd, addr); | |
6ef4fb38 | 101 | pr_cont(", *pte=%016llx", pte_val(*pte)); |
1d18c47c CM |
102 | pte_unmap(pte); |
103 | } while(0); | |
104 | ||
6ef4fb38 | 105 | pr_cont("\n"); |
1d18c47c CM |
106 | } |
107 | ||
66dbd6e6 CM |
108 | #ifdef CONFIG_ARM64_HW_AFDBM |
109 | /* | |
110 | * This function sets the access flags (dirty, accessed), as well as write | |
111 | * permission, and only to a more permissive setting. | |
112 | * | |
113 | * It needs to cope with hardware update of the accessed/dirty state by other | |
114 | * agents in the system and can safely skip the __sync_icache_dcache() call as, | |
115 | * like set_pte_at(), the PTE is never changed from no-exec to exec here. | |
116 | * | |
117 | * Returns whether or not the PTE actually changed. | |
118 | */ | |
119 | int ptep_set_access_flags(struct vm_area_struct *vma, | |
120 | unsigned long address, pte_t *ptep, | |
121 | pte_t entry, int dirty) | |
122 | { | |
123 | pteval_t old_pteval; | |
124 | unsigned int tmp; | |
125 | ||
126 | if (pte_same(*ptep, entry)) | |
127 | return 0; | |
128 | ||
129 | /* only preserve the access flags and write permission */ | |
130 | pte_val(entry) &= PTE_AF | PTE_WRITE | PTE_DIRTY; | |
131 | ||
132 | /* | |
133 | * PTE_RDONLY is cleared by default in the asm below, so set it in | |
134 | * back if necessary (read-only or clean PTE). | |
135 | */ | |
0106d456 | 136 | if (!pte_write(entry) || !pte_sw_dirty(entry)) |
66dbd6e6 CM |
137 | pte_val(entry) |= PTE_RDONLY; |
138 | ||
139 | /* | |
140 | * Setting the flags must be done atomically to avoid racing with the | |
141 | * hardware update of the access/dirty state. | |
142 | */ | |
143 | asm volatile("// ptep_set_access_flags\n" | |
144 | " prfm pstl1strm, %2\n" | |
145 | "1: ldxr %0, %2\n" | |
146 | " and %0, %0, %3 // clear PTE_RDONLY\n" | |
147 | " orr %0, %0, %4 // set flags\n" | |
148 | " stxr %w1, %0, %2\n" | |
149 | " cbnz %w1, 1b\n" | |
150 | : "=&r" (old_pteval), "=&r" (tmp), "+Q" (pte_val(*ptep)) | |
151 | : "L" (~PTE_RDONLY), "r" (pte_val(entry))); | |
152 | ||
153 | flush_tlb_fix_spurious_fault(vma, address); | |
154 | return 1; | |
155 | } | |
156 | #endif | |
157 | ||
9adeb8e7 LA |
158 | static bool is_el1_instruction_abort(unsigned int esr) |
159 | { | |
160 | return ESR_ELx_EC(esr) == ESR_ELx_EC_IABT_CUR; | |
161 | } | |
162 | ||
1d18c47c CM |
163 | /* |
164 | * The kernel tried to access some page that wasn't present. | |
165 | */ | |
166 | static void __do_kernel_fault(struct mm_struct *mm, unsigned long addr, | |
167 | unsigned int esr, struct pt_regs *regs) | |
168 | { | |
169 | /* | |
170 | * Are we prepared to handle this kernel fault? | |
9adeb8e7 | 171 | * We are almost certainly not prepared to handle instruction faults. |
1d18c47c | 172 | */ |
9adeb8e7 | 173 | if (!is_el1_instruction_abort(esr) && fixup_exception(regs)) |
1d18c47c CM |
174 | return; |
175 | ||
176 | /* | |
177 | * No handler, we'll have to terminate things with extreme prejudice. | |
178 | */ | |
179 | bust_spinlocks(1); | |
180 | pr_alert("Unable to handle kernel %s at virtual address %08lx\n", | |
181 | (addr < PAGE_SIZE) ? "NULL pointer dereference" : | |
182 | "paging request", addr); | |
183 | ||
184 | show_pte(mm, addr); | |
185 | die("Oops", regs, esr); | |
186 | bust_spinlocks(0); | |
187 | do_exit(SIGKILL); | |
188 | } | |
189 | ||
190 | /* | |
191 | * Something tried to access memory that isn't in our memory map. User mode | |
192 | * accesses just cause a SIGSEGV | |
193 | */ | |
194 | static void __do_user_fault(struct task_struct *tsk, unsigned long addr, | |
195 | unsigned int esr, unsigned int sig, int code, | |
196 | struct pt_regs *regs) | |
197 | { | |
198 | struct siginfo si; | |
199 | ||
f871d268 | 200 | if (unhandled_signal(tsk, sig) && show_unhandled_signals_ratelimited()) { |
3495386b CM |
201 | pr_info("%s[%d]: unhandled %s (%d) at 0x%08lx, esr 0x%03x\n", |
202 | tsk->comm, task_pid_nr(tsk), fault_name(esr), sig, | |
203 | addr, esr); | |
1d18c47c CM |
204 | show_pte(tsk->mm, addr); |
205 | show_regs(regs); | |
206 | } | |
207 | ||
208 | tsk->thread.fault_address = addr; | |
9141300a | 209 | tsk->thread.fault_code = esr; |
1d18c47c CM |
210 | si.si_signo = sig; |
211 | si.si_errno = 0; | |
212 | si.si_code = code; | |
213 | si.si_addr = (void __user *)addr; | |
214 | force_sig_info(sig, &si, tsk); | |
215 | } | |
216 | ||
59f67e16 | 217 | static void do_bad_area(unsigned long addr, unsigned int esr, struct pt_regs *regs) |
1d18c47c CM |
218 | { |
219 | struct task_struct *tsk = current; | |
220 | struct mm_struct *mm = tsk->active_mm; | |
221 | ||
222 | /* | |
223 | * If we are in kernel mode at this point, we have no context to | |
224 | * handle this fault with. | |
225 | */ | |
226 | if (user_mode(regs)) | |
227 | __do_user_fault(tsk, addr, esr, SIGSEGV, SEGV_MAPERR, regs); | |
228 | else | |
229 | __do_kernel_fault(mm, addr, esr, regs); | |
230 | } | |
231 | ||
232 | #define VM_FAULT_BADMAP 0x010000 | |
233 | #define VM_FAULT_BADACCESS 0x020000 | |
234 | ||
1d18c47c | 235 | static int __do_page_fault(struct mm_struct *mm, unsigned long addr, |
db6f4106 | 236 | unsigned int mm_flags, unsigned long vm_flags, |
1d18c47c CM |
237 | struct task_struct *tsk) |
238 | { | |
239 | struct vm_area_struct *vma; | |
240 | int fault; | |
241 | ||
242 | vma = find_vma(mm, addr); | |
243 | fault = VM_FAULT_BADMAP; | |
244 | if (unlikely(!vma)) | |
245 | goto out; | |
246 | if (unlikely(vma->vm_start > addr)) | |
247 | goto check_stack; | |
248 | ||
249 | /* | |
250 | * Ok, we have a good vm_area for this memory access, so we can handle | |
251 | * it. | |
252 | */ | |
253 | good_area: | |
db6f4106 WD |
254 | /* |
255 | * Check that the permissions on the VMA allow for the fault which | |
cab15ce6 | 256 | * occurred. |
db6f4106 WD |
257 | */ |
258 | if (!(vma->vm_flags & vm_flags)) { | |
1d18c47c CM |
259 | fault = VM_FAULT_BADACCESS; |
260 | goto out; | |
261 | } | |
262 | ||
dcddffd4 | 263 | return handle_mm_fault(vma, addr & PAGE_MASK, mm_flags); |
1d18c47c CM |
264 | |
265 | check_stack: | |
266 | if (vma->vm_flags & VM_GROWSDOWN && !expand_stack(vma, addr)) | |
267 | goto good_area; | |
268 | out: | |
269 | return fault; | |
270 | } | |
271 | ||
78688963 | 272 | static inline bool is_permission_fault(unsigned int esr, struct pt_regs *regs) |
57f4959b | 273 | { |
275f344b | 274 | unsigned int ec = ESR_ELx_EC(esr); |
57f4959b JM |
275 | unsigned int fsc_type = esr & ESR_ELx_FSC_TYPE; |
276 | ||
78688963 CM |
277 | if (ec != ESR_ELx_EC_DABT_CUR && ec != ESR_ELx_EC_IABT_CUR) |
278 | return false; | |
279 | ||
280 | if (system_uses_ttbr0_pan()) | |
281 | return fsc_type == ESR_ELx_FSC_FAULT && | |
282 | (regs->pstate & PSR_PAN_BIT); | |
283 | else | |
284 | return fsc_type == ESR_ELx_FSC_PERM; | |
57f4959b JM |
285 | } |
286 | ||
541ec870 MR |
287 | static bool is_el0_instruction_abort(unsigned int esr) |
288 | { | |
289 | return ESR_ELx_EC(esr) == ESR_ELx_EC_IABT_LOW; | |
290 | } | |
291 | ||
1d18c47c CM |
292 | static int __kprobes do_page_fault(unsigned long addr, unsigned int esr, |
293 | struct pt_regs *regs) | |
294 | { | |
295 | struct task_struct *tsk; | |
296 | struct mm_struct *mm; | |
297 | int fault, sig, code; | |
cab15ce6 | 298 | unsigned long vm_flags = VM_READ | VM_WRITE; |
db6f4106 WD |
299 | unsigned int mm_flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE; |
300 | ||
2dd0e8d2 SP |
301 | if (notify_page_fault(regs, esr)) |
302 | return 0; | |
303 | ||
1d18c47c CM |
304 | tsk = current; |
305 | mm = tsk->mm; | |
306 | ||
1d18c47c CM |
307 | /* |
308 | * If we're in an interrupt or have no user context, we must not take | |
309 | * the fault. | |
310 | */ | |
70ffdb93 | 311 | if (faulthandler_disabled() || !mm) |
1d18c47c CM |
312 | goto no_context; |
313 | ||
759496ba JW |
314 | if (user_mode(regs)) |
315 | mm_flags |= FAULT_FLAG_USER; | |
316 | ||
541ec870 | 317 | if (is_el0_instruction_abort(esr)) { |
759496ba | 318 | vm_flags = VM_EXEC; |
aed40e01 | 319 | } else if ((esr & ESR_ELx_WNR) && !(esr & ESR_ELx_CM)) { |
759496ba JW |
320 | vm_flags = VM_WRITE; |
321 | mm_flags |= FAULT_FLAG_WRITE; | |
322 | } | |
323 | ||
78688963 | 324 | if (addr < USER_DS && is_permission_fault(esr, regs)) { |
e19a6ee2 JM |
325 | /* regs->orig_addr_limit may be 0 if we entered from EL0 */ |
326 | if (regs->orig_addr_limit == KERNEL_DS) | |
70c8abc2 | 327 | die("Accessing user space memory with fs=KERNEL_DS", regs, esr); |
70544196 | 328 | |
9adeb8e7 LA |
329 | if (is_el1_instruction_abort(esr)) |
330 | die("Attempting to execute userspace memory", regs, esr); | |
331 | ||
57f4959b | 332 | if (!search_exception_tables(regs->pc)) |
70c8abc2 | 333 | die("Accessing user space memory outside uaccess.h routines", regs, esr); |
57f4959b | 334 | } |
338d4f49 | 335 | |
1d18c47c CM |
336 | /* |
337 | * As per x86, we may deadlock here. However, since the kernel only | |
338 | * validly references user space from well defined areas of the code, | |
339 | * we can bug out early if this is from code which shouldn't. | |
340 | */ | |
341 | if (!down_read_trylock(&mm->mmap_sem)) { | |
342 | if (!user_mode(regs) && !search_exception_tables(regs->pc)) | |
343 | goto no_context; | |
344 | retry: | |
345 | down_read(&mm->mmap_sem); | |
346 | } else { | |
347 | /* | |
348 | * The above down_read_trylock() might have succeeded in which | |
349 | * case, we'll have missed the might_sleep() from down_read(). | |
350 | */ | |
351 | might_sleep(); | |
352 | #ifdef CONFIG_DEBUG_VM | |
353 | if (!user_mode(regs) && !search_exception_tables(regs->pc)) | |
354 | goto no_context; | |
355 | #endif | |
356 | } | |
357 | ||
db6f4106 | 358 | fault = __do_page_fault(mm, addr, mm_flags, vm_flags, tsk); |
1d18c47c CM |
359 | |
360 | /* | |
361 | * If we need to retry but a fatal signal is pending, handle the | |
362 | * signal first. We do not need to release the mmap_sem because it | |
363 | * would already be released in __lock_page_or_retry in mm/filemap.c. | |
364 | */ | |
365 | if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current)) | |
366 | return 0; | |
367 | ||
368 | /* | |
369 | * Major/minor page fault accounting is only done on the initial | |
370 | * attempt. If we go through a retry, it is extremely likely that the | |
371 | * page will be found in page cache at that point. | |
372 | */ | |
373 | ||
374 | perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, addr); | |
db6f4106 | 375 | if (mm_flags & FAULT_FLAG_ALLOW_RETRY) { |
1d18c47c CM |
376 | if (fault & VM_FAULT_MAJOR) { |
377 | tsk->maj_flt++; | |
378 | perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1, regs, | |
379 | addr); | |
380 | } else { | |
381 | tsk->min_flt++; | |
382 | perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, 1, regs, | |
383 | addr); | |
384 | } | |
385 | if (fault & VM_FAULT_RETRY) { | |
386 | /* | |
387 | * Clear FAULT_FLAG_ALLOW_RETRY to avoid any risk of | |
388 | * starvation. | |
389 | */ | |
db6f4106 | 390 | mm_flags &= ~FAULT_FLAG_ALLOW_RETRY; |
569ba74a | 391 | mm_flags |= FAULT_FLAG_TRIED; |
1d18c47c CM |
392 | goto retry; |
393 | } | |
394 | } | |
395 | ||
396 | up_read(&mm->mmap_sem); | |
397 | ||
398 | /* | |
0e8fb931 | 399 | * Handle the "normal" case first - VM_FAULT_MAJOR |
1d18c47c CM |
400 | */ |
401 | if (likely(!(fault & (VM_FAULT_ERROR | VM_FAULT_BADMAP | | |
402 | VM_FAULT_BADACCESS)))) | |
403 | return 0; | |
404 | ||
87134102 JW |
405 | /* |
406 | * If we are in kernel mode at this point, we have no context to | |
407 | * handle this fault with. | |
408 | */ | |
409 | if (!user_mode(regs)) | |
410 | goto no_context; | |
411 | ||
1d18c47c CM |
412 | if (fault & VM_FAULT_OOM) { |
413 | /* | |
414 | * We ran out of memory, call the OOM killer, and return to | |
415 | * userspace (which will retry the fault, or kill us if we got | |
416 | * oom-killed). | |
417 | */ | |
418 | pagefault_out_of_memory(); | |
419 | return 0; | |
420 | } | |
421 | ||
1d18c47c CM |
422 | if (fault & VM_FAULT_SIGBUS) { |
423 | /* | |
424 | * We had some memory, but were unable to successfully fix up | |
425 | * this page fault. | |
426 | */ | |
427 | sig = SIGBUS; | |
428 | code = BUS_ADRERR; | |
429 | } else { | |
430 | /* | |
431 | * Something tried to access memory that isn't in our memory | |
432 | * map. | |
433 | */ | |
434 | sig = SIGSEGV; | |
435 | code = fault == VM_FAULT_BADACCESS ? | |
436 | SEGV_ACCERR : SEGV_MAPERR; | |
437 | } | |
438 | ||
439 | __do_user_fault(tsk, addr, esr, sig, code, regs); | |
440 | return 0; | |
441 | ||
442 | no_context: | |
443 | __do_kernel_fault(mm, addr, esr, regs); | |
444 | return 0; | |
445 | } | |
446 | ||
447 | /* | |
448 | * First Level Translation Fault Handler | |
449 | * | |
450 | * We enter here because the first level page table doesn't contain a valid | |
451 | * entry for the address. | |
452 | * | |
453 | * If the address is in kernel space (>= TASK_SIZE), then we are probably | |
454 | * faulting in the vmalloc() area. | |
455 | * | |
456 | * If the init_task's first level page tables contains the relevant entry, we | |
457 | * copy the it to this task. If not, we send the process a signal, fixup the | |
458 | * exception, or oops the kernel. | |
459 | * | |
460 | * NOTE! We MUST NOT take any locks for this case. We may be in an interrupt | |
461 | * or a critical region, and should only copy the information from the master | |
462 | * page table, nothing more. | |
463 | */ | |
464 | static int __kprobes do_translation_fault(unsigned long addr, | |
465 | unsigned int esr, | |
466 | struct pt_regs *regs) | |
467 | { | |
468 | if (addr < TASK_SIZE) | |
469 | return do_page_fault(addr, esr, regs); | |
470 | ||
471 | do_bad_area(addr, esr, regs); | |
472 | return 0; | |
473 | } | |
474 | ||
52d7523d EL |
475 | static int do_alignment_fault(unsigned long addr, unsigned int esr, |
476 | struct pt_regs *regs) | |
477 | { | |
478 | do_bad_area(addr, esr, regs); | |
479 | return 0; | |
480 | } | |
481 | ||
1d18c47c CM |
482 | /* |
483 | * This abort handler always returns "fault". | |
484 | */ | |
485 | static int do_bad(unsigned long addr, unsigned int esr, struct pt_regs *regs) | |
486 | { | |
487 | return 1; | |
488 | } | |
489 | ||
bbb1681e | 490 | static const struct fault_info { |
1d18c47c CM |
491 | int (*fn)(unsigned long addr, unsigned int esr, struct pt_regs *regs); |
492 | int sig; | |
493 | int code; | |
494 | const char *name; | |
495 | } fault_info[] = { | |
496 | { do_bad, SIGBUS, 0, "ttbr address size fault" }, | |
497 | { do_bad, SIGBUS, 0, "level 1 address size fault" }, | |
498 | { do_bad, SIGBUS, 0, "level 2 address size fault" }, | |
499 | { do_bad, SIGBUS, 0, "level 3 address size fault" }, | |
7f73f7ae | 500 | { do_translation_fault, SIGSEGV, SEGV_MAPERR, "level 0 translation fault" }, |
1d18c47c CM |
501 | { do_translation_fault, SIGSEGV, SEGV_MAPERR, "level 1 translation fault" }, |
502 | { do_translation_fault, SIGSEGV, SEGV_MAPERR, "level 2 translation fault" }, | |
503 | { do_page_fault, SIGSEGV, SEGV_MAPERR, "level 3 translation fault" }, | |
c03784ee | 504 | { do_bad, SIGBUS, 0, "unknown 8" }, |
084bd298 SC |
505 | { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 1 access flag fault" }, |
506 | { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 2 access flag fault" }, | |
1d18c47c | 507 | { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 3 access flag fault" }, |
c03784ee | 508 | { do_bad, SIGBUS, 0, "unknown 12" }, |
084bd298 SC |
509 | { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 1 permission fault" }, |
510 | { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 2 permission fault" }, | |
1d18c47c CM |
511 | { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 3 permission fault" }, |
512 | { do_bad, SIGBUS, 0, "synchronous external abort" }, | |
c03784ee | 513 | { do_bad, SIGBUS, 0, "unknown 17" }, |
1d18c47c CM |
514 | { do_bad, SIGBUS, 0, "unknown 18" }, |
515 | { do_bad, SIGBUS, 0, "unknown 19" }, | |
a8ada146 CM |
516 | { do_bad, SIGBUS, 0, "synchronous external abort (translation table walk)" }, |
517 | { do_bad, SIGBUS, 0, "synchronous external abort (translation table walk)" }, | |
518 | { do_bad, SIGBUS, 0, "synchronous external abort (translation table walk)" }, | |
519 | { do_bad, SIGBUS, 0, "synchronous external abort (translation table walk)" }, | |
1d18c47c | 520 | { do_bad, SIGBUS, 0, "synchronous parity error" }, |
c03784ee | 521 | { do_bad, SIGBUS, 0, "unknown 25" }, |
1d18c47c CM |
522 | { do_bad, SIGBUS, 0, "unknown 26" }, |
523 | { do_bad, SIGBUS, 0, "unknown 27" }, | |
c03784ee MR |
524 | { do_bad, SIGBUS, 0, "synchronous parity error (translation table walk)" }, |
525 | { do_bad, SIGBUS, 0, "synchronous parity error (translation table walk)" }, | |
526 | { do_bad, SIGBUS, 0, "synchronous parity error (translation table walk)" }, | |
527 | { do_bad, SIGBUS, 0, "synchronous parity error (translation table walk)" }, | |
1d18c47c | 528 | { do_bad, SIGBUS, 0, "unknown 32" }, |
52d7523d | 529 | { do_alignment_fault, SIGBUS, BUS_ADRALN, "alignment fault" }, |
c03784ee | 530 | { do_bad, SIGBUS, 0, "unknown 34" }, |
1d18c47c CM |
531 | { do_bad, SIGBUS, 0, "unknown 35" }, |
532 | { do_bad, SIGBUS, 0, "unknown 36" }, | |
533 | { do_bad, SIGBUS, 0, "unknown 37" }, | |
534 | { do_bad, SIGBUS, 0, "unknown 38" }, | |
535 | { do_bad, SIGBUS, 0, "unknown 39" }, | |
536 | { do_bad, SIGBUS, 0, "unknown 40" }, | |
537 | { do_bad, SIGBUS, 0, "unknown 41" }, | |
538 | { do_bad, SIGBUS, 0, "unknown 42" }, | |
539 | { do_bad, SIGBUS, 0, "unknown 43" }, | |
540 | { do_bad, SIGBUS, 0, "unknown 44" }, | |
541 | { do_bad, SIGBUS, 0, "unknown 45" }, | |
542 | { do_bad, SIGBUS, 0, "unknown 46" }, | |
543 | { do_bad, SIGBUS, 0, "unknown 47" }, | |
c03784ee | 544 | { do_bad, SIGBUS, 0, "TLB conflict abort" }, |
1d18c47c CM |
545 | { do_bad, SIGBUS, 0, "unknown 49" }, |
546 | { do_bad, SIGBUS, 0, "unknown 50" }, | |
547 | { do_bad, SIGBUS, 0, "unknown 51" }, | |
548 | { do_bad, SIGBUS, 0, "implementation fault (lockdown abort)" }, | |
c03784ee | 549 | { do_bad, SIGBUS, 0, "implementation fault (unsupported exclusive)" }, |
1d18c47c CM |
550 | { do_bad, SIGBUS, 0, "unknown 54" }, |
551 | { do_bad, SIGBUS, 0, "unknown 55" }, | |
552 | { do_bad, SIGBUS, 0, "unknown 56" }, | |
553 | { do_bad, SIGBUS, 0, "unknown 57" }, | |
c03784ee | 554 | { do_bad, SIGBUS, 0, "unknown 58" }, |
1d18c47c CM |
555 | { do_bad, SIGBUS, 0, "unknown 59" }, |
556 | { do_bad, SIGBUS, 0, "unknown 60" }, | |
c03784ee MR |
557 | { do_bad, SIGBUS, 0, "section domain fault" }, |
558 | { do_bad, SIGBUS, 0, "page domain fault" }, | |
1d18c47c CM |
559 | { do_bad, SIGBUS, 0, "unknown 63" }, |
560 | }; | |
561 | ||
3495386b CM |
562 | static const char *fault_name(unsigned int esr) |
563 | { | |
564 | const struct fault_info *inf = fault_info + (esr & 63); | |
565 | return inf->name; | |
566 | } | |
567 | ||
1d18c47c CM |
568 | /* |
569 | * Dispatch a data abort to the relevant handler. | |
570 | */ | |
571 | asmlinkage void __exception do_mem_abort(unsigned long addr, unsigned int esr, | |
572 | struct pt_regs *regs) | |
573 | { | |
574 | const struct fault_info *inf = fault_info + (esr & 63); | |
575 | struct siginfo info; | |
576 | ||
577 | if (!inf->fn(addr, esr, regs)) | |
578 | return; | |
579 | ||
580 | pr_alert("Unhandled fault: %s (0x%08x) at 0x%016lx\n", | |
581 | inf->name, esr, addr); | |
582 | ||
583 | info.si_signo = inf->sig; | |
584 | info.si_errno = 0; | |
585 | info.si_code = inf->code; | |
586 | info.si_addr = (void __user *)addr; | |
587 | arm64_notify_die("", regs, &info, esr); | |
588 | } | |
589 | ||
590 | /* | |
591 | * Handle stack alignment exceptions. | |
592 | */ | |
593 | asmlinkage void __exception do_sp_pc_abort(unsigned long addr, | |
594 | unsigned int esr, | |
595 | struct pt_regs *regs) | |
596 | { | |
597 | struct siginfo info; | |
9e793ab8 VM |
598 | struct task_struct *tsk = current; |
599 | ||
600 | if (show_unhandled_signals && unhandled_signal(tsk, SIGBUS)) | |
601 | pr_info_ratelimited("%s[%d]: %s exception: pc=%p sp=%p\n", | |
602 | tsk->comm, task_pid_nr(tsk), | |
603 | esr_get_class_string(esr), (void *)regs->pc, | |
604 | (void *)regs->sp); | |
1d18c47c CM |
605 | |
606 | info.si_signo = SIGBUS; | |
607 | info.si_errno = 0; | |
608 | info.si_code = BUS_ADRALN; | |
609 | info.si_addr = (void __user *)addr; | |
9e793ab8 | 610 | arm64_notify_die("Oops - SP/PC alignment exception", regs, &info, esr); |
1d18c47c CM |
611 | } |
612 | ||
9fb7410f DM |
613 | int __init early_brk64(unsigned long addr, unsigned int esr, |
614 | struct pt_regs *regs); | |
615 | ||
616 | /* | |
617 | * __refdata because early_brk64 is __init, but the reference to it is | |
618 | * clobbered at arch_initcall time. | |
619 | * See traps.c and debug-monitors.c:debug_traps_init(). | |
620 | */ | |
621 | static struct fault_info __refdata debug_fault_info[] = { | |
1d18c47c CM |
622 | { do_bad, SIGTRAP, TRAP_HWBKPT, "hardware breakpoint" }, |
623 | { do_bad, SIGTRAP, TRAP_HWBKPT, "hardware single-step" }, | |
624 | { do_bad, SIGTRAP, TRAP_HWBKPT, "hardware watchpoint" }, | |
625 | { do_bad, SIGBUS, 0, "unknown 3" }, | |
626 | { do_bad, SIGTRAP, TRAP_BRKPT, "aarch32 BKPT" }, | |
627 | { do_bad, SIGTRAP, 0, "aarch32 vector catch" }, | |
9fb7410f | 628 | { early_brk64, SIGTRAP, TRAP_BRKPT, "aarch64 BRK" }, |
1d18c47c CM |
629 | { do_bad, SIGBUS, 0, "unknown 7" }, |
630 | }; | |
631 | ||
632 | void __init hook_debug_fault_code(int nr, | |
633 | int (*fn)(unsigned long, unsigned int, struct pt_regs *), | |
634 | int sig, int code, const char *name) | |
635 | { | |
636 | BUG_ON(nr < 0 || nr >= ARRAY_SIZE(debug_fault_info)); | |
637 | ||
638 | debug_fault_info[nr].fn = fn; | |
639 | debug_fault_info[nr].sig = sig; | |
640 | debug_fault_info[nr].code = code; | |
641 | debug_fault_info[nr].name = name; | |
642 | } | |
643 | ||
644 | asmlinkage int __exception do_debug_exception(unsigned long addr, | |
645 | unsigned int esr, | |
646 | struct pt_regs *regs) | |
647 | { | |
648 | const struct fault_info *inf = debug_fault_info + DBG_ESR_EVT(esr); | |
649 | struct siginfo info; | |
6afedcd2 | 650 | int rv; |
1d18c47c | 651 | |
6afedcd2 JM |
652 | /* |
653 | * Tell lockdep we disabled irqs in entry.S. Do nothing if they were | |
654 | * already disabled to preserve the last enabled/disabled addresses. | |
655 | */ | |
656 | if (interrupts_enabled(regs)) | |
657 | trace_hardirqs_off(); | |
1d18c47c | 658 | |
6afedcd2 JM |
659 | if (!inf->fn(addr, esr, regs)) { |
660 | rv = 1; | |
661 | } else { | |
662 | pr_alert("Unhandled debug exception: %s (0x%08x) at 0x%016lx\n", | |
663 | inf->name, esr, addr); | |
664 | ||
665 | info.si_signo = inf->sig; | |
666 | info.si_errno = 0; | |
667 | info.si_code = inf->code; | |
668 | info.si_addr = (void __user *)addr; | |
669 | arm64_notify_die("", regs, &info, 0); | |
670 | rv = 0; | |
671 | } | |
1d18c47c | 672 | |
6afedcd2 JM |
673 | if (interrupts_enabled(regs)) |
674 | trace_hardirqs_on(); | |
1d18c47c | 675 | |
6afedcd2 | 676 | return rv; |
1d18c47c | 677 | } |
2dd0e8d2 | 678 | NOKPROBE_SYMBOL(do_debug_exception); |
338d4f49 JM |
679 | |
680 | #ifdef CONFIG_ARM64_PAN | |
2a6dcb2b | 681 | int cpu_enable_pan(void *__unused) |
338d4f49 | 682 | { |
7209c868 JM |
683 | /* |
684 | * We modify PSTATE. This won't work from irq context as the PSTATE | |
685 | * is discarded once we return from the exception. | |
686 | */ | |
687 | WARN_ON_ONCE(in_interrupt()); | |
688 | ||
338d4f49 | 689 | config_sctlr_el1(SCTLR_EL1_SPAN, 0); |
7209c868 | 690 | asm(SET_PSTATE_PAN(1)); |
2a6dcb2b | 691 | return 0; |
338d4f49 JM |
692 | } |
693 | #endif /* CONFIG_ARM64_PAN */ | |
57f4959b JM |
694 | |
695 | #ifdef CONFIG_ARM64_UAO | |
696 | /* | |
697 | * Kernel threads have fs=KERNEL_DS by default, and don't need to call | |
698 | * set_fs(), devtmpfs in particular relies on this behaviour. | |
699 | * We need to enable the feature at runtime (instead of adding it to | |
700 | * PSR_MODE_EL1h) as the feature may not be implemented by the cpu. | |
701 | */ | |
2a6dcb2b | 702 | int cpu_enable_uao(void *__unused) |
57f4959b JM |
703 | { |
704 | asm(SET_PSTATE_UAO(1)); | |
2a6dcb2b | 705 | return 0; |
57f4959b JM |
706 | } |
707 | #endif /* CONFIG_ARM64_UAO */ |