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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 | ||
21 | #include <linux/module.h> | |
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> | |
32 | ||
338d4f49 | 33 | #include <asm/cpufeature.h> |
1d18c47c CM |
34 | #include <asm/exception.h> |
35 | #include <asm/debug-monitors.h> | |
9141300a | 36 | #include <asm/esr.h> |
338d4f49 | 37 | #include <asm/sysreg.h> |
1d18c47c CM |
38 | #include <asm/system_misc.h> |
39 | #include <asm/pgtable.h> | |
40 | #include <asm/tlbflush.h> | |
41 | ||
3495386b CM |
42 | static const char *fault_name(unsigned int esr); |
43 | ||
2dd0e8d2 SP |
44 | #ifdef CONFIG_KPROBES |
45 | static inline int notify_page_fault(struct pt_regs *regs, unsigned int esr) | |
46 | { | |
47 | int ret = 0; | |
48 | ||
49 | /* kprobe_running() needs smp_processor_id() */ | |
50 | if (!user_mode(regs)) { | |
51 | preempt_disable(); | |
52 | if (kprobe_running() && kprobe_fault_handler(regs, esr)) | |
53 | ret = 1; | |
54 | preempt_enable(); | |
55 | } | |
56 | ||
57 | return ret; | |
58 | } | |
59 | #else | |
60 | static inline int notify_page_fault(struct pt_regs *regs, unsigned int esr) | |
61 | { | |
62 | return 0; | |
63 | } | |
64 | #endif | |
65 | ||
1d18c47c CM |
66 | /* |
67 | * Dump out the page tables associated with 'addr' in mm 'mm'. | |
68 | */ | |
69 | void show_pte(struct mm_struct *mm, unsigned long addr) | |
70 | { | |
71 | pgd_t *pgd; | |
72 | ||
73 | if (!mm) | |
74 | mm = &init_mm; | |
75 | ||
76 | pr_alert("pgd = %p\n", mm->pgd); | |
77 | pgd = pgd_offset(mm, addr); | |
78 | pr_alert("[%08lx] *pgd=%016llx", addr, pgd_val(*pgd)); | |
79 | ||
80 | do { | |
81 | pud_t *pud; | |
82 | pmd_t *pmd; | |
83 | pte_t *pte; | |
84 | ||
4339e3f3 | 85 | if (pgd_none(*pgd) || pgd_bad(*pgd)) |
1d18c47c CM |
86 | break; |
87 | ||
88 | pud = pud_offset(pgd, addr); | |
c79b954b | 89 | printk(", *pud=%016llx", pud_val(*pud)); |
4339e3f3 | 90 | if (pud_none(*pud) || pud_bad(*pud)) |
1d18c47c CM |
91 | break; |
92 | ||
93 | pmd = pmd_offset(pud, addr); | |
94 | printk(", *pmd=%016llx", pmd_val(*pmd)); | |
4339e3f3 | 95 | if (pmd_none(*pmd) || pmd_bad(*pmd)) |
1d18c47c CM |
96 | break; |
97 | ||
98 | pte = pte_offset_map(pmd, addr); | |
99 | printk(", *pte=%016llx", pte_val(*pte)); | |
100 | pte_unmap(pte); | |
101 | } while(0); | |
102 | ||
103 | printk("\n"); | |
104 | } | |
105 | ||
66dbd6e6 CM |
106 | #ifdef CONFIG_ARM64_HW_AFDBM |
107 | /* | |
108 | * This function sets the access flags (dirty, accessed), as well as write | |
109 | * permission, and only to a more permissive setting. | |
110 | * | |
111 | * It needs to cope with hardware update of the accessed/dirty state by other | |
112 | * agents in the system and can safely skip the __sync_icache_dcache() call as, | |
113 | * like set_pte_at(), the PTE is never changed from no-exec to exec here. | |
114 | * | |
115 | * Returns whether or not the PTE actually changed. | |
116 | */ | |
117 | int ptep_set_access_flags(struct vm_area_struct *vma, | |
118 | unsigned long address, pte_t *ptep, | |
119 | pte_t entry, int dirty) | |
120 | { | |
121 | pteval_t old_pteval; | |
122 | unsigned int tmp; | |
123 | ||
124 | if (pte_same(*ptep, entry)) | |
125 | return 0; | |
126 | ||
127 | /* only preserve the access flags and write permission */ | |
128 | pte_val(entry) &= PTE_AF | PTE_WRITE | PTE_DIRTY; | |
129 | ||
130 | /* | |
131 | * PTE_RDONLY is cleared by default in the asm below, so set it in | |
132 | * back if necessary (read-only or clean PTE). | |
133 | */ | |
0106d456 | 134 | if (!pte_write(entry) || !pte_sw_dirty(entry)) |
66dbd6e6 CM |
135 | pte_val(entry) |= PTE_RDONLY; |
136 | ||
137 | /* | |
138 | * Setting the flags must be done atomically to avoid racing with the | |
139 | * hardware update of the access/dirty state. | |
140 | */ | |
141 | asm volatile("// ptep_set_access_flags\n" | |
142 | " prfm pstl1strm, %2\n" | |
143 | "1: ldxr %0, %2\n" | |
144 | " and %0, %0, %3 // clear PTE_RDONLY\n" | |
145 | " orr %0, %0, %4 // set flags\n" | |
146 | " stxr %w1, %0, %2\n" | |
147 | " cbnz %w1, 1b\n" | |
148 | : "=&r" (old_pteval), "=&r" (tmp), "+Q" (pte_val(*ptep)) | |
149 | : "L" (~PTE_RDONLY), "r" (pte_val(entry))); | |
150 | ||
151 | flush_tlb_fix_spurious_fault(vma, address); | |
152 | return 1; | |
153 | } | |
154 | #endif | |
155 | ||
9adeb8e7 LA |
156 | static bool is_el1_instruction_abort(unsigned int esr) |
157 | { | |
158 | return ESR_ELx_EC(esr) == ESR_ELx_EC_IABT_CUR; | |
159 | } | |
160 | ||
1d18c47c CM |
161 | /* |
162 | * The kernel tried to access some page that wasn't present. | |
163 | */ | |
164 | static void __do_kernel_fault(struct mm_struct *mm, unsigned long addr, | |
165 | unsigned int esr, struct pt_regs *regs) | |
166 | { | |
167 | /* | |
168 | * Are we prepared to handle this kernel fault? | |
9adeb8e7 | 169 | * We are almost certainly not prepared to handle instruction faults. |
1d18c47c | 170 | */ |
9adeb8e7 | 171 | if (!is_el1_instruction_abort(esr) && fixup_exception(regs)) |
1d18c47c CM |
172 | return; |
173 | ||
174 | /* | |
175 | * No handler, we'll have to terminate things with extreme prejudice. | |
176 | */ | |
177 | bust_spinlocks(1); | |
178 | pr_alert("Unable to handle kernel %s at virtual address %08lx\n", | |
179 | (addr < PAGE_SIZE) ? "NULL pointer dereference" : | |
180 | "paging request", addr); | |
181 | ||
182 | show_pte(mm, addr); | |
183 | die("Oops", regs, esr); | |
184 | bust_spinlocks(0); | |
185 | do_exit(SIGKILL); | |
186 | } | |
187 | ||
188 | /* | |
189 | * Something tried to access memory that isn't in our memory map. User mode | |
190 | * accesses just cause a SIGSEGV | |
191 | */ | |
192 | static void __do_user_fault(struct task_struct *tsk, unsigned long addr, | |
193 | unsigned int esr, unsigned int sig, int code, | |
194 | struct pt_regs *regs) | |
195 | { | |
196 | struct siginfo si; | |
197 | ||
f871d268 | 198 | if (unhandled_signal(tsk, sig) && show_unhandled_signals_ratelimited()) { |
3495386b CM |
199 | pr_info("%s[%d]: unhandled %s (%d) at 0x%08lx, esr 0x%03x\n", |
200 | tsk->comm, task_pid_nr(tsk), fault_name(esr), sig, | |
201 | addr, esr); | |
1d18c47c CM |
202 | show_pte(tsk->mm, addr); |
203 | show_regs(regs); | |
204 | } | |
205 | ||
206 | tsk->thread.fault_address = addr; | |
9141300a | 207 | tsk->thread.fault_code = esr; |
1d18c47c CM |
208 | si.si_signo = sig; |
209 | si.si_errno = 0; | |
210 | si.si_code = code; | |
211 | si.si_addr = (void __user *)addr; | |
212 | force_sig_info(sig, &si, tsk); | |
213 | } | |
214 | ||
59f67e16 | 215 | static void do_bad_area(unsigned long addr, unsigned int esr, struct pt_regs *regs) |
1d18c47c CM |
216 | { |
217 | struct task_struct *tsk = current; | |
218 | struct mm_struct *mm = tsk->active_mm; | |
219 | ||
220 | /* | |
221 | * If we are in kernel mode at this point, we have no context to | |
222 | * handle this fault with. | |
223 | */ | |
224 | if (user_mode(regs)) | |
225 | __do_user_fault(tsk, addr, esr, SIGSEGV, SEGV_MAPERR, regs); | |
226 | else | |
227 | __do_kernel_fault(mm, addr, esr, regs); | |
228 | } | |
229 | ||
230 | #define VM_FAULT_BADMAP 0x010000 | |
231 | #define VM_FAULT_BADACCESS 0x020000 | |
232 | ||
1d18c47c | 233 | static int __do_page_fault(struct mm_struct *mm, unsigned long addr, |
db6f4106 | 234 | unsigned int mm_flags, unsigned long vm_flags, |
1d18c47c CM |
235 | struct task_struct *tsk) |
236 | { | |
237 | struct vm_area_struct *vma; | |
238 | int fault; | |
239 | ||
240 | vma = find_vma(mm, addr); | |
241 | fault = VM_FAULT_BADMAP; | |
242 | if (unlikely(!vma)) | |
243 | goto out; | |
244 | if (unlikely(vma->vm_start > addr)) | |
245 | goto check_stack; | |
246 | ||
247 | /* | |
248 | * Ok, we have a good vm_area for this memory access, so we can handle | |
249 | * it. | |
250 | */ | |
251 | good_area: | |
db6f4106 WD |
252 | /* |
253 | * Check that the permissions on the VMA allow for the fault which | |
5a0fdfad CM |
254 | * occurred. If we encountered a write or exec fault, we must have |
255 | * appropriate permissions, otherwise we allow any permission. | |
db6f4106 WD |
256 | */ |
257 | if (!(vma->vm_flags & vm_flags)) { | |
1d18c47c CM |
258 | fault = VM_FAULT_BADACCESS; |
259 | goto out; | |
260 | } | |
261 | ||
dcddffd4 | 262 | return handle_mm_fault(vma, addr & PAGE_MASK, mm_flags); |
1d18c47c CM |
263 | |
264 | check_stack: | |
265 | if (vma->vm_flags & VM_GROWSDOWN && !expand_stack(vma, addr)) | |
266 | goto good_area; | |
267 | out: | |
268 | return fault; | |
269 | } | |
270 | ||
541ec870 | 271 | static inline bool is_permission_fault(unsigned int esr) |
57f4959b | 272 | { |
275f344b | 273 | unsigned int ec = ESR_ELx_EC(esr); |
57f4959b JM |
274 | unsigned int fsc_type = esr & ESR_ELx_FSC_TYPE; |
275 | ||
9adeb8e7 LA |
276 | return (ec == ESR_ELx_EC_DABT_CUR && fsc_type == ESR_ELx_FSC_PERM) || |
277 | (ec == ESR_ELx_EC_IABT_CUR && fsc_type == ESR_ELx_FSC_PERM); | |
57f4959b JM |
278 | } |
279 | ||
541ec870 MR |
280 | static bool is_el0_instruction_abort(unsigned int esr) |
281 | { | |
282 | return ESR_ELx_EC(esr) == ESR_ELx_EC_IABT_LOW; | |
283 | } | |
284 | ||
1d18c47c CM |
285 | static int __kprobes do_page_fault(unsigned long addr, unsigned int esr, |
286 | struct pt_regs *regs) | |
287 | { | |
288 | struct task_struct *tsk; | |
289 | struct mm_struct *mm; | |
290 | int fault, sig, code; | |
5a0fdfad | 291 | unsigned long vm_flags = VM_READ | VM_WRITE | VM_EXEC; |
db6f4106 WD |
292 | unsigned int mm_flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE; |
293 | ||
2dd0e8d2 SP |
294 | if (notify_page_fault(regs, esr)) |
295 | return 0; | |
296 | ||
1d18c47c CM |
297 | tsk = current; |
298 | mm = tsk->mm; | |
299 | ||
1d18c47c CM |
300 | /* |
301 | * If we're in an interrupt or have no user context, we must not take | |
302 | * the fault. | |
303 | */ | |
70ffdb93 | 304 | if (faulthandler_disabled() || !mm) |
1d18c47c CM |
305 | goto no_context; |
306 | ||
759496ba JW |
307 | if (user_mode(regs)) |
308 | mm_flags |= FAULT_FLAG_USER; | |
309 | ||
541ec870 | 310 | if (is_el0_instruction_abort(esr)) { |
759496ba | 311 | vm_flags = VM_EXEC; |
aed40e01 | 312 | } else if ((esr & ESR_ELx_WNR) && !(esr & ESR_ELx_CM)) { |
759496ba JW |
313 | vm_flags = VM_WRITE; |
314 | mm_flags |= FAULT_FLAG_WRITE; | |
315 | } | |
316 | ||
541ec870 | 317 | if (is_permission_fault(esr) && (addr < USER_DS)) { |
e19a6ee2 JM |
318 | /* regs->orig_addr_limit may be 0 if we entered from EL0 */ |
319 | if (regs->orig_addr_limit == KERNEL_DS) | |
70c8abc2 | 320 | die("Accessing user space memory with fs=KERNEL_DS", regs, esr); |
70544196 | 321 | |
9adeb8e7 LA |
322 | if (is_el1_instruction_abort(esr)) |
323 | die("Attempting to execute userspace memory", regs, esr); | |
324 | ||
57f4959b | 325 | if (!search_exception_tables(regs->pc)) |
70c8abc2 | 326 | die("Accessing user space memory outside uaccess.h routines", regs, esr); |
57f4959b | 327 | } |
338d4f49 | 328 | |
1d18c47c CM |
329 | /* |
330 | * As per x86, we may deadlock here. However, since the kernel only | |
331 | * validly references user space from well defined areas of the code, | |
332 | * we can bug out early if this is from code which shouldn't. | |
333 | */ | |
334 | if (!down_read_trylock(&mm->mmap_sem)) { | |
335 | if (!user_mode(regs) && !search_exception_tables(regs->pc)) | |
336 | goto no_context; | |
337 | retry: | |
338 | down_read(&mm->mmap_sem); | |
339 | } else { | |
340 | /* | |
341 | * The above down_read_trylock() might have succeeded in which | |
342 | * case, we'll have missed the might_sleep() from down_read(). | |
343 | */ | |
344 | might_sleep(); | |
345 | #ifdef CONFIG_DEBUG_VM | |
346 | if (!user_mode(regs) && !search_exception_tables(regs->pc)) | |
347 | goto no_context; | |
348 | #endif | |
349 | } | |
350 | ||
db6f4106 | 351 | fault = __do_page_fault(mm, addr, mm_flags, vm_flags, tsk); |
1d18c47c CM |
352 | |
353 | /* | |
354 | * If we need to retry but a fatal signal is pending, handle the | |
355 | * signal first. We do not need to release the mmap_sem because it | |
356 | * would already be released in __lock_page_or_retry in mm/filemap.c. | |
357 | */ | |
358 | if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current)) | |
359 | return 0; | |
360 | ||
361 | /* | |
362 | * Major/minor page fault accounting is only done on the initial | |
363 | * attempt. If we go through a retry, it is extremely likely that the | |
364 | * page will be found in page cache at that point. | |
365 | */ | |
366 | ||
367 | perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, addr); | |
db6f4106 | 368 | if (mm_flags & FAULT_FLAG_ALLOW_RETRY) { |
1d18c47c CM |
369 | if (fault & VM_FAULT_MAJOR) { |
370 | tsk->maj_flt++; | |
371 | perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1, regs, | |
372 | addr); | |
373 | } else { | |
374 | tsk->min_flt++; | |
375 | perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, 1, regs, | |
376 | addr); | |
377 | } | |
378 | if (fault & VM_FAULT_RETRY) { | |
379 | /* | |
380 | * Clear FAULT_FLAG_ALLOW_RETRY to avoid any risk of | |
381 | * starvation. | |
382 | */ | |
db6f4106 | 383 | mm_flags &= ~FAULT_FLAG_ALLOW_RETRY; |
569ba74a | 384 | mm_flags |= FAULT_FLAG_TRIED; |
1d18c47c CM |
385 | goto retry; |
386 | } | |
387 | } | |
388 | ||
389 | up_read(&mm->mmap_sem); | |
390 | ||
391 | /* | |
0e8fb931 | 392 | * Handle the "normal" case first - VM_FAULT_MAJOR |
1d18c47c CM |
393 | */ |
394 | if (likely(!(fault & (VM_FAULT_ERROR | VM_FAULT_BADMAP | | |
395 | VM_FAULT_BADACCESS)))) | |
396 | return 0; | |
397 | ||
87134102 JW |
398 | /* |
399 | * If we are in kernel mode at this point, we have no context to | |
400 | * handle this fault with. | |
401 | */ | |
402 | if (!user_mode(regs)) | |
403 | goto no_context; | |
404 | ||
1d18c47c CM |
405 | if (fault & VM_FAULT_OOM) { |
406 | /* | |
407 | * We ran out of memory, call the OOM killer, and return to | |
408 | * userspace (which will retry the fault, or kill us if we got | |
409 | * oom-killed). | |
410 | */ | |
411 | pagefault_out_of_memory(); | |
412 | return 0; | |
413 | } | |
414 | ||
1d18c47c CM |
415 | if (fault & VM_FAULT_SIGBUS) { |
416 | /* | |
417 | * We had some memory, but were unable to successfully fix up | |
418 | * this page fault. | |
419 | */ | |
420 | sig = SIGBUS; | |
421 | code = BUS_ADRERR; | |
422 | } else { | |
423 | /* | |
424 | * Something tried to access memory that isn't in our memory | |
425 | * map. | |
426 | */ | |
427 | sig = SIGSEGV; | |
428 | code = fault == VM_FAULT_BADACCESS ? | |
429 | SEGV_ACCERR : SEGV_MAPERR; | |
430 | } | |
431 | ||
432 | __do_user_fault(tsk, addr, esr, sig, code, regs); | |
433 | return 0; | |
434 | ||
435 | no_context: | |
436 | __do_kernel_fault(mm, addr, esr, regs); | |
437 | return 0; | |
438 | } | |
439 | ||
440 | /* | |
441 | * First Level Translation Fault Handler | |
442 | * | |
443 | * We enter here because the first level page table doesn't contain a valid | |
444 | * entry for the address. | |
445 | * | |
446 | * If the address is in kernel space (>= TASK_SIZE), then we are probably | |
447 | * faulting in the vmalloc() area. | |
448 | * | |
449 | * If the init_task's first level page tables contains the relevant entry, we | |
450 | * copy the it to this task. If not, we send the process a signal, fixup the | |
451 | * exception, or oops the kernel. | |
452 | * | |
453 | * NOTE! We MUST NOT take any locks for this case. We may be in an interrupt | |
454 | * or a critical region, and should only copy the information from the master | |
455 | * page table, nothing more. | |
456 | */ | |
457 | static int __kprobes do_translation_fault(unsigned long addr, | |
458 | unsigned int esr, | |
459 | struct pt_regs *regs) | |
460 | { | |
461 | if (addr < TASK_SIZE) | |
462 | return do_page_fault(addr, esr, regs); | |
463 | ||
464 | do_bad_area(addr, esr, regs); | |
465 | return 0; | |
466 | } | |
467 | ||
52d7523d EL |
468 | static int do_alignment_fault(unsigned long addr, unsigned int esr, |
469 | struct pt_regs *regs) | |
470 | { | |
471 | do_bad_area(addr, esr, regs); | |
472 | return 0; | |
473 | } | |
474 | ||
1d18c47c CM |
475 | /* |
476 | * This abort handler always returns "fault". | |
477 | */ | |
478 | static int do_bad(unsigned long addr, unsigned int esr, struct pt_regs *regs) | |
479 | { | |
480 | return 1; | |
481 | } | |
482 | ||
bbb1681e | 483 | static const struct fault_info { |
1d18c47c CM |
484 | int (*fn)(unsigned long addr, unsigned int esr, struct pt_regs *regs); |
485 | int sig; | |
486 | int code; | |
487 | const char *name; | |
488 | } fault_info[] = { | |
489 | { do_bad, SIGBUS, 0, "ttbr address size fault" }, | |
490 | { do_bad, SIGBUS, 0, "level 1 address size fault" }, | |
491 | { do_bad, SIGBUS, 0, "level 2 address size fault" }, | |
492 | { do_bad, SIGBUS, 0, "level 3 address size fault" }, | |
7f73f7ae | 493 | { do_translation_fault, SIGSEGV, SEGV_MAPERR, "level 0 translation fault" }, |
1d18c47c CM |
494 | { do_translation_fault, SIGSEGV, SEGV_MAPERR, "level 1 translation fault" }, |
495 | { do_translation_fault, SIGSEGV, SEGV_MAPERR, "level 2 translation fault" }, | |
496 | { do_page_fault, SIGSEGV, SEGV_MAPERR, "level 3 translation fault" }, | |
c03784ee | 497 | { do_bad, SIGBUS, 0, "unknown 8" }, |
084bd298 SC |
498 | { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 1 access flag fault" }, |
499 | { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 2 access flag fault" }, | |
1d18c47c | 500 | { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 3 access flag fault" }, |
c03784ee | 501 | { do_bad, SIGBUS, 0, "unknown 12" }, |
084bd298 SC |
502 | { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 1 permission fault" }, |
503 | { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 2 permission fault" }, | |
1d18c47c CM |
504 | { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 3 permission fault" }, |
505 | { do_bad, SIGBUS, 0, "synchronous external abort" }, | |
c03784ee | 506 | { do_bad, SIGBUS, 0, "unknown 17" }, |
1d18c47c CM |
507 | { do_bad, SIGBUS, 0, "unknown 18" }, |
508 | { do_bad, SIGBUS, 0, "unknown 19" }, | |
509 | { do_bad, SIGBUS, 0, "synchronous abort (translation table walk)" }, | |
510 | { do_bad, SIGBUS, 0, "synchronous abort (translation table walk)" }, | |
511 | { do_bad, SIGBUS, 0, "synchronous abort (translation table walk)" }, | |
512 | { do_bad, SIGBUS, 0, "synchronous abort (translation table walk)" }, | |
513 | { do_bad, SIGBUS, 0, "synchronous parity error" }, | |
c03784ee | 514 | { do_bad, SIGBUS, 0, "unknown 25" }, |
1d18c47c CM |
515 | { do_bad, SIGBUS, 0, "unknown 26" }, |
516 | { do_bad, SIGBUS, 0, "unknown 27" }, | |
c03784ee MR |
517 | { do_bad, SIGBUS, 0, "synchronous parity error (translation table walk)" }, |
518 | { do_bad, SIGBUS, 0, "synchronous parity error (translation table walk)" }, | |
519 | { do_bad, SIGBUS, 0, "synchronous parity error (translation table walk)" }, | |
520 | { do_bad, SIGBUS, 0, "synchronous parity error (translation table walk)" }, | |
1d18c47c | 521 | { do_bad, SIGBUS, 0, "unknown 32" }, |
52d7523d | 522 | { do_alignment_fault, SIGBUS, BUS_ADRALN, "alignment fault" }, |
c03784ee | 523 | { do_bad, SIGBUS, 0, "unknown 34" }, |
1d18c47c CM |
524 | { do_bad, SIGBUS, 0, "unknown 35" }, |
525 | { do_bad, SIGBUS, 0, "unknown 36" }, | |
526 | { do_bad, SIGBUS, 0, "unknown 37" }, | |
527 | { do_bad, SIGBUS, 0, "unknown 38" }, | |
528 | { do_bad, SIGBUS, 0, "unknown 39" }, | |
529 | { do_bad, SIGBUS, 0, "unknown 40" }, | |
530 | { do_bad, SIGBUS, 0, "unknown 41" }, | |
531 | { do_bad, SIGBUS, 0, "unknown 42" }, | |
532 | { do_bad, SIGBUS, 0, "unknown 43" }, | |
533 | { do_bad, SIGBUS, 0, "unknown 44" }, | |
534 | { do_bad, SIGBUS, 0, "unknown 45" }, | |
535 | { do_bad, SIGBUS, 0, "unknown 46" }, | |
536 | { do_bad, SIGBUS, 0, "unknown 47" }, | |
c03784ee | 537 | { do_bad, SIGBUS, 0, "TLB conflict abort" }, |
1d18c47c CM |
538 | { do_bad, SIGBUS, 0, "unknown 49" }, |
539 | { do_bad, SIGBUS, 0, "unknown 50" }, | |
540 | { do_bad, SIGBUS, 0, "unknown 51" }, | |
541 | { do_bad, SIGBUS, 0, "implementation fault (lockdown abort)" }, | |
c03784ee | 542 | { do_bad, SIGBUS, 0, "implementation fault (unsupported exclusive)" }, |
1d18c47c CM |
543 | { do_bad, SIGBUS, 0, "unknown 54" }, |
544 | { do_bad, SIGBUS, 0, "unknown 55" }, | |
545 | { do_bad, SIGBUS, 0, "unknown 56" }, | |
546 | { do_bad, SIGBUS, 0, "unknown 57" }, | |
c03784ee | 547 | { do_bad, SIGBUS, 0, "unknown 58" }, |
1d18c47c CM |
548 | { do_bad, SIGBUS, 0, "unknown 59" }, |
549 | { do_bad, SIGBUS, 0, "unknown 60" }, | |
c03784ee MR |
550 | { do_bad, SIGBUS, 0, "section domain fault" }, |
551 | { do_bad, SIGBUS, 0, "page domain fault" }, | |
1d18c47c CM |
552 | { do_bad, SIGBUS, 0, "unknown 63" }, |
553 | }; | |
554 | ||
3495386b CM |
555 | static const char *fault_name(unsigned int esr) |
556 | { | |
557 | const struct fault_info *inf = fault_info + (esr & 63); | |
558 | return inf->name; | |
559 | } | |
560 | ||
1d18c47c CM |
561 | /* |
562 | * Dispatch a data abort to the relevant handler. | |
563 | */ | |
564 | asmlinkage void __exception do_mem_abort(unsigned long addr, unsigned int esr, | |
565 | struct pt_regs *regs) | |
566 | { | |
567 | const struct fault_info *inf = fault_info + (esr & 63); | |
568 | struct siginfo info; | |
569 | ||
570 | if (!inf->fn(addr, esr, regs)) | |
571 | return; | |
572 | ||
573 | pr_alert("Unhandled fault: %s (0x%08x) at 0x%016lx\n", | |
574 | inf->name, esr, addr); | |
575 | ||
576 | info.si_signo = inf->sig; | |
577 | info.si_errno = 0; | |
578 | info.si_code = inf->code; | |
579 | info.si_addr = (void __user *)addr; | |
580 | arm64_notify_die("", regs, &info, esr); | |
581 | } | |
582 | ||
583 | /* | |
584 | * Handle stack alignment exceptions. | |
585 | */ | |
586 | asmlinkage void __exception do_sp_pc_abort(unsigned long addr, | |
587 | unsigned int esr, | |
588 | struct pt_regs *regs) | |
589 | { | |
590 | struct siginfo info; | |
9e793ab8 VM |
591 | struct task_struct *tsk = current; |
592 | ||
593 | if (show_unhandled_signals && unhandled_signal(tsk, SIGBUS)) | |
594 | pr_info_ratelimited("%s[%d]: %s exception: pc=%p sp=%p\n", | |
595 | tsk->comm, task_pid_nr(tsk), | |
596 | esr_get_class_string(esr), (void *)regs->pc, | |
597 | (void *)regs->sp); | |
1d18c47c CM |
598 | |
599 | info.si_signo = SIGBUS; | |
600 | info.si_errno = 0; | |
601 | info.si_code = BUS_ADRALN; | |
602 | info.si_addr = (void __user *)addr; | |
9e793ab8 | 603 | arm64_notify_die("Oops - SP/PC alignment exception", regs, &info, esr); |
1d18c47c CM |
604 | } |
605 | ||
9fb7410f DM |
606 | int __init early_brk64(unsigned long addr, unsigned int esr, |
607 | struct pt_regs *regs); | |
608 | ||
609 | /* | |
610 | * __refdata because early_brk64 is __init, but the reference to it is | |
611 | * clobbered at arch_initcall time. | |
612 | * See traps.c and debug-monitors.c:debug_traps_init(). | |
613 | */ | |
614 | static struct fault_info __refdata debug_fault_info[] = { | |
1d18c47c CM |
615 | { do_bad, SIGTRAP, TRAP_HWBKPT, "hardware breakpoint" }, |
616 | { do_bad, SIGTRAP, TRAP_HWBKPT, "hardware single-step" }, | |
617 | { do_bad, SIGTRAP, TRAP_HWBKPT, "hardware watchpoint" }, | |
618 | { do_bad, SIGBUS, 0, "unknown 3" }, | |
619 | { do_bad, SIGTRAP, TRAP_BRKPT, "aarch32 BKPT" }, | |
620 | { do_bad, SIGTRAP, 0, "aarch32 vector catch" }, | |
9fb7410f | 621 | { early_brk64, SIGTRAP, TRAP_BRKPT, "aarch64 BRK" }, |
1d18c47c CM |
622 | { do_bad, SIGBUS, 0, "unknown 7" }, |
623 | }; | |
624 | ||
625 | void __init hook_debug_fault_code(int nr, | |
626 | int (*fn)(unsigned long, unsigned int, struct pt_regs *), | |
627 | int sig, int code, const char *name) | |
628 | { | |
629 | BUG_ON(nr < 0 || nr >= ARRAY_SIZE(debug_fault_info)); | |
630 | ||
631 | debug_fault_info[nr].fn = fn; | |
632 | debug_fault_info[nr].sig = sig; | |
633 | debug_fault_info[nr].code = code; | |
634 | debug_fault_info[nr].name = name; | |
635 | } | |
636 | ||
637 | asmlinkage int __exception do_debug_exception(unsigned long addr, | |
638 | unsigned int esr, | |
639 | struct pt_regs *regs) | |
640 | { | |
641 | const struct fault_info *inf = debug_fault_info + DBG_ESR_EVT(esr); | |
642 | struct siginfo info; | |
6afedcd2 | 643 | int rv; |
1d18c47c | 644 | |
6afedcd2 JM |
645 | /* |
646 | * Tell lockdep we disabled irqs in entry.S. Do nothing if they were | |
647 | * already disabled to preserve the last enabled/disabled addresses. | |
648 | */ | |
649 | if (interrupts_enabled(regs)) | |
650 | trace_hardirqs_off(); | |
1d18c47c | 651 | |
6afedcd2 JM |
652 | if (!inf->fn(addr, esr, regs)) { |
653 | rv = 1; | |
654 | } else { | |
655 | pr_alert("Unhandled debug exception: %s (0x%08x) at 0x%016lx\n", | |
656 | inf->name, esr, addr); | |
657 | ||
658 | info.si_signo = inf->sig; | |
659 | info.si_errno = 0; | |
660 | info.si_code = inf->code; | |
661 | info.si_addr = (void __user *)addr; | |
662 | arm64_notify_die("", regs, &info, 0); | |
663 | rv = 0; | |
664 | } | |
1d18c47c | 665 | |
6afedcd2 JM |
666 | if (interrupts_enabled(regs)) |
667 | trace_hardirqs_on(); | |
1d18c47c | 668 | |
6afedcd2 | 669 | return rv; |
1d18c47c | 670 | } |
2dd0e8d2 | 671 | NOKPROBE_SYMBOL(do_debug_exception); |
338d4f49 JM |
672 | |
673 | #ifdef CONFIG_ARM64_PAN | |
dbb4e152 | 674 | void cpu_enable_pan(void *__unused) |
338d4f49 JM |
675 | { |
676 | config_sctlr_el1(SCTLR_EL1_SPAN, 0); | |
677 | } | |
678 | #endif /* CONFIG_ARM64_PAN */ | |
57f4959b JM |
679 | |
680 | #ifdef CONFIG_ARM64_UAO | |
681 | /* | |
682 | * Kernel threads have fs=KERNEL_DS by default, and don't need to call | |
683 | * set_fs(), devtmpfs in particular relies on this behaviour. | |
684 | * We need to enable the feature at runtime (instead of adding it to | |
685 | * PSR_MODE_EL1h) as the feature may not be implemented by the cpu. | |
686 | */ | |
687 | void cpu_enable_uao(void *__unused) | |
688 | { | |
689 | asm(SET_PSTATE_UAO(1)); | |
690 | } | |
691 | #endif /* CONFIG_ARM64_UAO */ |