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