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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 | ||
1d18c47c CM |
44 | /* |
45 | * Dump out the page tables associated with 'addr' in mm 'mm'. | |
46 | */ | |
47 | void show_pte(struct mm_struct *mm, unsigned long addr) | |
48 | { | |
49 | pgd_t *pgd; | |
50 | ||
51 | if (!mm) | |
52 | mm = &init_mm; | |
53 | ||
54 | pr_alert("pgd = %p\n", mm->pgd); | |
55 | pgd = pgd_offset(mm, addr); | |
56 | pr_alert("[%08lx] *pgd=%016llx", addr, pgd_val(*pgd)); | |
57 | ||
58 | do { | |
59 | pud_t *pud; | |
60 | pmd_t *pmd; | |
61 | pte_t *pte; | |
62 | ||
4339e3f3 | 63 | if (pgd_none(*pgd) || pgd_bad(*pgd)) |
1d18c47c CM |
64 | break; |
65 | ||
66 | pud = pud_offset(pgd, addr); | |
c79b954b | 67 | printk(", *pud=%016llx", pud_val(*pud)); |
4339e3f3 | 68 | if (pud_none(*pud) || pud_bad(*pud)) |
1d18c47c CM |
69 | break; |
70 | ||
71 | pmd = pmd_offset(pud, addr); | |
72 | printk(", *pmd=%016llx", pmd_val(*pmd)); | |
4339e3f3 | 73 | if (pmd_none(*pmd) || pmd_bad(*pmd)) |
1d18c47c CM |
74 | break; |
75 | ||
76 | pte = pte_offset_map(pmd, addr); | |
77 | printk(", *pte=%016llx", pte_val(*pte)); | |
78 | pte_unmap(pte); | |
79 | } while(0); | |
80 | ||
81 | printk("\n"); | |
82 | } | |
83 | ||
84 | /* | |
85 | * The kernel tried to access some page that wasn't present. | |
86 | */ | |
87 | static void __do_kernel_fault(struct mm_struct *mm, unsigned long addr, | |
88 | unsigned int esr, struct pt_regs *regs) | |
89 | { | |
90 | /* | |
91 | * Are we prepared to handle this kernel fault? | |
92 | */ | |
93 | if (fixup_exception(regs)) | |
94 | return; | |
95 | ||
96 | /* | |
97 | * No handler, we'll have to terminate things with extreme prejudice. | |
98 | */ | |
99 | bust_spinlocks(1); | |
100 | pr_alert("Unable to handle kernel %s at virtual address %08lx\n", | |
101 | (addr < PAGE_SIZE) ? "NULL pointer dereference" : | |
102 | "paging request", addr); | |
103 | ||
104 | show_pte(mm, addr); | |
105 | die("Oops", regs, esr); | |
106 | bust_spinlocks(0); | |
107 | do_exit(SIGKILL); | |
108 | } | |
109 | ||
110 | /* | |
111 | * Something tried to access memory that isn't in our memory map. User mode | |
112 | * accesses just cause a SIGSEGV | |
113 | */ | |
114 | static void __do_user_fault(struct task_struct *tsk, unsigned long addr, | |
115 | unsigned int esr, unsigned int sig, int code, | |
116 | struct pt_regs *regs) | |
117 | { | |
118 | struct siginfo si; | |
119 | ||
f871d268 | 120 | if (unhandled_signal(tsk, sig) && show_unhandled_signals_ratelimited()) { |
3495386b CM |
121 | pr_info("%s[%d]: unhandled %s (%d) at 0x%08lx, esr 0x%03x\n", |
122 | tsk->comm, task_pid_nr(tsk), fault_name(esr), sig, | |
123 | addr, esr); | |
1d18c47c CM |
124 | show_pte(tsk->mm, addr); |
125 | show_regs(regs); | |
126 | } | |
127 | ||
128 | tsk->thread.fault_address = addr; | |
9141300a | 129 | tsk->thread.fault_code = esr; |
1d18c47c CM |
130 | si.si_signo = sig; |
131 | si.si_errno = 0; | |
132 | si.si_code = code; | |
133 | si.si_addr = (void __user *)addr; | |
134 | force_sig_info(sig, &si, tsk); | |
135 | } | |
136 | ||
59f67e16 | 137 | static void do_bad_area(unsigned long addr, unsigned int esr, struct pt_regs *regs) |
1d18c47c CM |
138 | { |
139 | struct task_struct *tsk = current; | |
140 | struct mm_struct *mm = tsk->active_mm; | |
141 | ||
142 | /* | |
143 | * If we are in kernel mode at this point, we have no context to | |
144 | * handle this fault with. | |
145 | */ | |
146 | if (user_mode(regs)) | |
147 | __do_user_fault(tsk, addr, esr, SIGSEGV, SEGV_MAPERR, regs); | |
148 | else | |
149 | __do_kernel_fault(mm, addr, esr, regs); | |
150 | } | |
151 | ||
152 | #define VM_FAULT_BADMAP 0x010000 | |
153 | #define VM_FAULT_BADACCESS 0x020000 | |
154 | ||
1d18c47c CM |
155 | #define ESR_LNX_EXEC (1 << 24) |
156 | ||
1d18c47c | 157 | static int __do_page_fault(struct mm_struct *mm, unsigned long addr, |
db6f4106 | 158 | unsigned int mm_flags, unsigned long vm_flags, |
1d18c47c CM |
159 | struct task_struct *tsk) |
160 | { | |
161 | struct vm_area_struct *vma; | |
162 | int fault; | |
163 | ||
164 | vma = find_vma(mm, addr); | |
165 | fault = VM_FAULT_BADMAP; | |
166 | if (unlikely(!vma)) | |
167 | goto out; | |
168 | if (unlikely(vma->vm_start > addr)) | |
169 | goto check_stack; | |
170 | ||
171 | /* | |
172 | * Ok, we have a good vm_area for this memory access, so we can handle | |
173 | * it. | |
174 | */ | |
175 | good_area: | |
db6f4106 WD |
176 | /* |
177 | * Check that the permissions on the VMA allow for the fault which | |
5a0fdfad CM |
178 | * occurred. If we encountered a write or exec fault, we must have |
179 | * appropriate permissions, otherwise we allow any permission. | |
db6f4106 WD |
180 | */ |
181 | if (!(vma->vm_flags & vm_flags)) { | |
1d18c47c CM |
182 | fault = VM_FAULT_BADACCESS; |
183 | goto out; | |
184 | } | |
185 | ||
db6f4106 | 186 | return handle_mm_fault(mm, vma, addr & PAGE_MASK, mm_flags); |
1d18c47c CM |
187 | |
188 | check_stack: | |
189 | if (vma->vm_flags & VM_GROWSDOWN && !expand_stack(vma, addr)) | |
190 | goto good_area; | |
191 | out: | |
192 | return fault; | |
193 | } | |
194 | ||
57f4959b JM |
195 | static inline int permission_fault(unsigned int esr) |
196 | { | |
197 | unsigned int ec = (esr & ESR_ELx_EC_MASK) >> ESR_ELx_EC_SHIFT; | |
198 | unsigned int fsc_type = esr & ESR_ELx_FSC_TYPE; | |
199 | ||
200 | return (ec == ESR_ELx_EC_DABT_CUR && fsc_type == ESR_ELx_FSC_PERM); | |
201 | } | |
202 | ||
1d18c47c CM |
203 | static int __kprobes do_page_fault(unsigned long addr, unsigned int esr, |
204 | struct pt_regs *regs) | |
205 | { | |
206 | struct task_struct *tsk; | |
207 | struct mm_struct *mm; | |
208 | int fault, sig, code; | |
5a0fdfad | 209 | unsigned long vm_flags = VM_READ | VM_WRITE | VM_EXEC; |
db6f4106 WD |
210 | unsigned int mm_flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE; |
211 | ||
1d18c47c CM |
212 | tsk = current; |
213 | mm = tsk->mm; | |
214 | ||
215 | /* Enable interrupts if they were enabled in the parent context. */ | |
216 | if (interrupts_enabled(regs)) | |
217 | local_irq_enable(); | |
218 | ||
219 | /* | |
220 | * If we're in an interrupt or have no user context, we must not take | |
221 | * the fault. | |
222 | */ | |
70ffdb93 | 223 | if (faulthandler_disabled() || !mm) |
1d18c47c CM |
224 | goto no_context; |
225 | ||
759496ba JW |
226 | if (user_mode(regs)) |
227 | mm_flags |= FAULT_FLAG_USER; | |
228 | ||
229 | if (esr & ESR_LNX_EXEC) { | |
230 | vm_flags = VM_EXEC; | |
aed40e01 | 231 | } else if ((esr & ESR_ELx_WNR) && !(esr & ESR_ELx_CM)) { |
759496ba JW |
232 | vm_flags = VM_WRITE; |
233 | mm_flags |= FAULT_FLAG_WRITE; | |
234 | } | |
235 | ||
57f4959b | 236 | if (permission_fault(esr) && (addr < USER_DS)) { |
e950631e | 237 | if (get_fs() == KERNEL_DS) |
70544196 JM |
238 | panic("Accessing user space memory with fs=KERNEL_DS"); |
239 | ||
57f4959b JM |
240 | if (!search_exception_tables(regs->pc)) |
241 | panic("Accessing user space memory outside uaccess.h routines"); | |
242 | } | |
338d4f49 | 243 | |
1d18c47c CM |
244 | /* |
245 | * As per x86, we may deadlock here. However, since the kernel only | |
246 | * validly references user space from well defined areas of the code, | |
247 | * we can bug out early if this is from code which shouldn't. | |
248 | */ | |
249 | if (!down_read_trylock(&mm->mmap_sem)) { | |
250 | if (!user_mode(regs) && !search_exception_tables(regs->pc)) | |
251 | goto no_context; | |
252 | retry: | |
253 | down_read(&mm->mmap_sem); | |
254 | } else { | |
255 | /* | |
256 | * The above down_read_trylock() might have succeeded in which | |
257 | * case, we'll have missed the might_sleep() from down_read(). | |
258 | */ | |
259 | might_sleep(); | |
260 | #ifdef CONFIG_DEBUG_VM | |
261 | if (!user_mode(regs) && !search_exception_tables(regs->pc)) | |
262 | goto no_context; | |
263 | #endif | |
264 | } | |
265 | ||
db6f4106 | 266 | fault = __do_page_fault(mm, addr, mm_flags, vm_flags, tsk); |
1d18c47c CM |
267 | |
268 | /* | |
269 | * If we need to retry but a fatal signal is pending, handle the | |
270 | * signal first. We do not need to release the mmap_sem because it | |
271 | * would already be released in __lock_page_or_retry in mm/filemap.c. | |
272 | */ | |
273 | if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current)) | |
274 | return 0; | |
275 | ||
276 | /* | |
277 | * Major/minor page fault accounting is only done on the initial | |
278 | * attempt. If we go through a retry, it is extremely likely that the | |
279 | * page will be found in page cache at that point. | |
280 | */ | |
281 | ||
282 | perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, addr); | |
db6f4106 | 283 | if (mm_flags & FAULT_FLAG_ALLOW_RETRY) { |
1d18c47c CM |
284 | if (fault & VM_FAULT_MAJOR) { |
285 | tsk->maj_flt++; | |
286 | perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1, regs, | |
287 | addr); | |
288 | } else { | |
289 | tsk->min_flt++; | |
290 | perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, 1, regs, | |
291 | addr); | |
292 | } | |
293 | if (fault & VM_FAULT_RETRY) { | |
294 | /* | |
295 | * Clear FAULT_FLAG_ALLOW_RETRY to avoid any risk of | |
296 | * starvation. | |
297 | */ | |
db6f4106 | 298 | mm_flags &= ~FAULT_FLAG_ALLOW_RETRY; |
569ba74a | 299 | mm_flags |= FAULT_FLAG_TRIED; |
1d18c47c CM |
300 | goto retry; |
301 | } | |
302 | } | |
303 | ||
304 | up_read(&mm->mmap_sem); | |
305 | ||
306 | /* | |
307 | * Handle the "normal" case first - VM_FAULT_MAJOR / VM_FAULT_MINOR | |
308 | */ | |
309 | if (likely(!(fault & (VM_FAULT_ERROR | VM_FAULT_BADMAP | | |
310 | VM_FAULT_BADACCESS)))) | |
311 | return 0; | |
312 | ||
87134102 JW |
313 | /* |
314 | * If we are in kernel mode at this point, we have no context to | |
315 | * handle this fault with. | |
316 | */ | |
317 | if (!user_mode(regs)) | |
318 | goto no_context; | |
319 | ||
1d18c47c CM |
320 | if (fault & VM_FAULT_OOM) { |
321 | /* | |
322 | * We ran out of memory, call the OOM killer, and return to | |
323 | * userspace (which will retry the fault, or kill us if we got | |
324 | * oom-killed). | |
325 | */ | |
326 | pagefault_out_of_memory(); | |
327 | return 0; | |
328 | } | |
329 | ||
1d18c47c CM |
330 | if (fault & VM_FAULT_SIGBUS) { |
331 | /* | |
332 | * We had some memory, but were unable to successfully fix up | |
333 | * this page fault. | |
334 | */ | |
335 | sig = SIGBUS; | |
336 | code = BUS_ADRERR; | |
337 | } else { | |
338 | /* | |
339 | * Something tried to access memory that isn't in our memory | |
340 | * map. | |
341 | */ | |
342 | sig = SIGSEGV; | |
343 | code = fault == VM_FAULT_BADACCESS ? | |
344 | SEGV_ACCERR : SEGV_MAPERR; | |
345 | } | |
346 | ||
347 | __do_user_fault(tsk, addr, esr, sig, code, regs); | |
348 | return 0; | |
349 | ||
350 | no_context: | |
351 | __do_kernel_fault(mm, addr, esr, regs); | |
352 | return 0; | |
353 | } | |
354 | ||
355 | /* | |
356 | * First Level Translation Fault Handler | |
357 | * | |
358 | * We enter here because the first level page table doesn't contain a valid | |
359 | * entry for the address. | |
360 | * | |
361 | * If the address is in kernel space (>= TASK_SIZE), then we are probably | |
362 | * faulting in the vmalloc() area. | |
363 | * | |
364 | * If the init_task's first level page tables contains the relevant entry, we | |
365 | * copy the it to this task. If not, we send the process a signal, fixup the | |
366 | * exception, or oops the kernel. | |
367 | * | |
368 | * NOTE! We MUST NOT take any locks for this case. We may be in an interrupt | |
369 | * or a critical region, and should only copy the information from the master | |
370 | * page table, nothing more. | |
371 | */ | |
372 | static int __kprobes do_translation_fault(unsigned long addr, | |
373 | unsigned int esr, | |
374 | struct pt_regs *regs) | |
375 | { | |
376 | if (addr < TASK_SIZE) | |
377 | return do_page_fault(addr, esr, regs); | |
378 | ||
379 | do_bad_area(addr, esr, regs); | |
380 | return 0; | |
381 | } | |
382 | ||
1d18c47c CM |
383 | /* |
384 | * This abort handler always returns "fault". | |
385 | */ | |
386 | static int do_bad(unsigned long addr, unsigned int esr, struct pt_regs *regs) | |
387 | { | |
388 | return 1; | |
389 | } | |
390 | ||
391 | static struct fault_info { | |
392 | int (*fn)(unsigned long addr, unsigned int esr, struct pt_regs *regs); | |
393 | int sig; | |
394 | int code; | |
395 | const char *name; | |
396 | } fault_info[] = { | |
397 | { do_bad, SIGBUS, 0, "ttbr address size fault" }, | |
398 | { do_bad, SIGBUS, 0, "level 1 address size fault" }, | |
399 | { do_bad, SIGBUS, 0, "level 2 address size fault" }, | |
400 | { do_bad, SIGBUS, 0, "level 3 address size fault" }, | |
7f73f7ae | 401 | { do_translation_fault, SIGSEGV, SEGV_MAPERR, "level 0 translation fault" }, |
1d18c47c CM |
402 | { do_translation_fault, SIGSEGV, SEGV_MAPERR, "level 1 translation fault" }, |
403 | { do_translation_fault, SIGSEGV, SEGV_MAPERR, "level 2 translation fault" }, | |
404 | { do_page_fault, SIGSEGV, SEGV_MAPERR, "level 3 translation fault" }, | |
c03784ee | 405 | { do_bad, SIGBUS, 0, "unknown 8" }, |
084bd298 SC |
406 | { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 1 access flag fault" }, |
407 | { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 2 access flag fault" }, | |
1d18c47c | 408 | { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 3 access flag fault" }, |
c03784ee | 409 | { do_bad, SIGBUS, 0, "unknown 12" }, |
084bd298 SC |
410 | { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 1 permission fault" }, |
411 | { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 2 permission fault" }, | |
1d18c47c CM |
412 | { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 3 permission fault" }, |
413 | { do_bad, SIGBUS, 0, "synchronous external abort" }, | |
c03784ee | 414 | { do_bad, SIGBUS, 0, "unknown 17" }, |
1d18c47c CM |
415 | { do_bad, SIGBUS, 0, "unknown 18" }, |
416 | { do_bad, SIGBUS, 0, "unknown 19" }, | |
417 | { do_bad, SIGBUS, 0, "synchronous abort (translation table walk)" }, | |
418 | { do_bad, SIGBUS, 0, "synchronous abort (translation table walk)" }, | |
419 | { do_bad, SIGBUS, 0, "synchronous abort (translation table walk)" }, | |
420 | { do_bad, SIGBUS, 0, "synchronous abort (translation table walk)" }, | |
421 | { do_bad, SIGBUS, 0, "synchronous parity error" }, | |
c03784ee | 422 | { do_bad, SIGBUS, 0, "unknown 25" }, |
1d18c47c CM |
423 | { do_bad, SIGBUS, 0, "unknown 26" }, |
424 | { do_bad, SIGBUS, 0, "unknown 27" }, | |
c03784ee MR |
425 | { do_bad, SIGBUS, 0, "synchronous parity error (translation table walk)" }, |
426 | { do_bad, SIGBUS, 0, "synchronous parity error (translation table walk)" }, | |
427 | { do_bad, SIGBUS, 0, "synchronous parity error (translation table walk)" }, | |
428 | { do_bad, SIGBUS, 0, "synchronous parity error (translation table walk)" }, | |
1d18c47c CM |
429 | { do_bad, SIGBUS, 0, "unknown 32" }, |
430 | { do_bad, SIGBUS, BUS_ADRALN, "alignment fault" }, | |
c03784ee | 431 | { do_bad, SIGBUS, 0, "unknown 34" }, |
1d18c47c CM |
432 | { do_bad, SIGBUS, 0, "unknown 35" }, |
433 | { do_bad, SIGBUS, 0, "unknown 36" }, | |
434 | { do_bad, SIGBUS, 0, "unknown 37" }, | |
435 | { do_bad, SIGBUS, 0, "unknown 38" }, | |
436 | { do_bad, SIGBUS, 0, "unknown 39" }, | |
437 | { do_bad, SIGBUS, 0, "unknown 40" }, | |
438 | { do_bad, SIGBUS, 0, "unknown 41" }, | |
439 | { do_bad, SIGBUS, 0, "unknown 42" }, | |
440 | { do_bad, SIGBUS, 0, "unknown 43" }, | |
441 | { do_bad, SIGBUS, 0, "unknown 44" }, | |
442 | { do_bad, SIGBUS, 0, "unknown 45" }, | |
443 | { do_bad, SIGBUS, 0, "unknown 46" }, | |
444 | { do_bad, SIGBUS, 0, "unknown 47" }, | |
c03784ee | 445 | { do_bad, SIGBUS, 0, "TLB conflict abort" }, |
1d18c47c CM |
446 | { do_bad, SIGBUS, 0, "unknown 49" }, |
447 | { do_bad, SIGBUS, 0, "unknown 50" }, | |
448 | { do_bad, SIGBUS, 0, "unknown 51" }, | |
449 | { do_bad, SIGBUS, 0, "implementation fault (lockdown abort)" }, | |
c03784ee | 450 | { do_bad, SIGBUS, 0, "implementation fault (unsupported exclusive)" }, |
1d18c47c CM |
451 | { do_bad, SIGBUS, 0, "unknown 54" }, |
452 | { do_bad, SIGBUS, 0, "unknown 55" }, | |
453 | { do_bad, SIGBUS, 0, "unknown 56" }, | |
454 | { do_bad, SIGBUS, 0, "unknown 57" }, | |
c03784ee | 455 | { do_bad, SIGBUS, 0, "unknown 58" }, |
1d18c47c CM |
456 | { do_bad, SIGBUS, 0, "unknown 59" }, |
457 | { do_bad, SIGBUS, 0, "unknown 60" }, | |
c03784ee MR |
458 | { do_bad, SIGBUS, 0, "section domain fault" }, |
459 | { do_bad, SIGBUS, 0, "page domain fault" }, | |
1d18c47c CM |
460 | { do_bad, SIGBUS, 0, "unknown 63" }, |
461 | }; | |
462 | ||
3495386b CM |
463 | static const char *fault_name(unsigned int esr) |
464 | { | |
465 | const struct fault_info *inf = fault_info + (esr & 63); | |
466 | return inf->name; | |
467 | } | |
468 | ||
1d18c47c CM |
469 | /* |
470 | * Dispatch a data abort to the relevant handler. | |
471 | */ | |
472 | asmlinkage void __exception do_mem_abort(unsigned long addr, unsigned int esr, | |
473 | struct pt_regs *regs) | |
474 | { | |
475 | const struct fault_info *inf = fault_info + (esr & 63); | |
476 | struct siginfo info; | |
477 | ||
478 | if (!inf->fn(addr, esr, regs)) | |
479 | return; | |
480 | ||
481 | pr_alert("Unhandled fault: %s (0x%08x) at 0x%016lx\n", | |
482 | inf->name, esr, addr); | |
483 | ||
484 | info.si_signo = inf->sig; | |
485 | info.si_errno = 0; | |
486 | info.si_code = inf->code; | |
487 | info.si_addr = (void __user *)addr; | |
488 | arm64_notify_die("", regs, &info, esr); | |
489 | } | |
490 | ||
491 | /* | |
492 | * Handle stack alignment exceptions. | |
493 | */ | |
494 | asmlinkage void __exception do_sp_pc_abort(unsigned long addr, | |
495 | unsigned int esr, | |
496 | struct pt_regs *regs) | |
497 | { | |
498 | struct siginfo info; | |
9e793ab8 VM |
499 | struct task_struct *tsk = current; |
500 | ||
501 | if (show_unhandled_signals && unhandled_signal(tsk, SIGBUS)) | |
502 | pr_info_ratelimited("%s[%d]: %s exception: pc=%p sp=%p\n", | |
503 | tsk->comm, task_pid_nr(tsk), | |
504 | esr_get_class_string(esr), (void *)regs->pc, | |
505 | (void *)regs->sp); | |
1d18c47c CM |
506 | |
507 | info.si_signo = SIGBUS; | |
508 | info.si_errno = 0; | |
509 | info.si_code = BUS_ADRALN; | |
510 | info.si_addr = (void __user *)addr; | |
9e793ab8 | 511 | arm64_notify_die("Oops - SP/PC alignment exception", regs, &info, esr); |
1d18c47c CM |
512 | } |
513 | ||
9fb7410f DM |
514 | int __init early_brk64(unsigned long addr, unsigned int esr, |
515 | struct pt_regs *regs); | |
516 | ||
517 | /* | |
518 | * __refdata because early_brk64 is __init, but the reference to it is | |
519 | * clobbered at arch_initcall time. | |
520 | * See traps.c and debug-monitors.c:debug_traps_init(). | |
521 | */ | |
522 | static struct fault_info __refdata debug_fault_info[] = { | |
1d18c47c CM |
523 | { do_bad, SIGTRAP, TRAP_HWBKPT, "hardware breakpoint" }, |
524 | { do_bad, SIGTRAP, TRAP_HWBKPT, "hardware single-step" }, | |
525 | { do_bad, SIGTRAP, TRAP_HWBKPT, "hardware watchpoint" }, | |
526 | { do_bad, SIGBUS, 0, "unknown 3" }, | |
527 | { do_bad, SIGTRAP, TRAP_BRKPT, "aarch32 BKPT" }, | |
528 | { do_bad, SIGTRAP, 0, "aarch32 vector catch" }, | |
9fb7410f | 529 | { early_brk64, SIGTRAP, TRAP_BRKPT, "aarch64 BRK" }, |
1d18c47c CM |
530 | { do_bad, SIGBUS, 0, "unknown 7" }, |
531 | }; | |
532 | ||
533 | void __init hook_debug_fault_code(int nr, | |
534 | int (*fn)(unsigned long, unsigned int, struct pt_regs *), | |
535 | int sig, int code, const char *name) | |
536 | { | |
537 | BUG_ON(nr < 0 || nr >= ARRAY_SIZE(debug_fault_info)); | |
538 | ||
539 | debug_fault_info[nr].fn = fn; | |
540 | debug_fault_info[nr].sig = sig; | |
541 | debug_fault_info[nr].code = code; | |
542 | debug_fault_info[nr].name = name; | |
543 | } | |
544 | ||
545 | asmlinkage int __exception do_debug_exception(unsigned long addr, | |
546 | unsigned int esr, | |
547 | struct pt_regs *regs) | |
548 | { | |
549 | const struct fault_info *inf = debug_fault_info + DBG_ESR_EVT(esr); | |
550 | struct siginfo info; | |
551 | ||
552 | if (!inf->fn(addr, esr, regs)) | |
553 | return 1; | |
554 | ||
555 | pr_alert("Unhandled debug exception: %s (0x%08x) at 0x%016lx\n", | |
556 | inf->name, esr, addr); | |
557 | ||
558 | info.si_signo = inf->sig; | |
559 | info.si_errno = 0; | |
560 | info.si_code = inf->code; | |
561 | info.si_addr = (void __user *)addr; | |
9141300a | 562 | arm64_notify_die("", regs, &info, 0); |
1d18c47c CM |
563 | |
564 | return 0; | |
565 | } | |
338d4f49 JM |
566 | |
567 | #ifdef CONFIG_ARM64_PAN | |
dbb4e152 | 568 | void cpu_enable_pan(void *__unused) |
338d4f49 JM |
569 | { |
570 | config_sctlr_el1(SCTLR_EL1_SPAN, 0); | |
571 | } | |
572 | #endif /* CONFIG_ARM64_PAN */ | |
57f4959b JM |
573 | |
574 | #ifdef CONFIG_ARM64_UAO | |
575 | /* | |
576 | * Kernel threads have fs=KERNEL_DS by default, and don't need to call | |
577 | * set_fs(), devtmpfs in particular relies on this behaviour. | |
578 | * We need to enable the feature at runtime (instead of adding it to | |
579 | * PSR_MODE_EL1h) as the feature may not be implemented by the cpu. | |
580 | */ | |
581 | void cpu_enable_uao(void *__unused) | |
582 | { | |
583 | asm(SET_PSTATE_UAO(1)); | |
584 | } | |
585 | #endif /* CONFIG_ARM64_UAO */ |