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> |
e7c600f1 | 34 | #include <linux/hugetlb.h> |
1d18c47c | 35 | |
7209c868 | 36 | #include <asm/bug.h> |
3bbf7157 | 37 | #include <asm/cmpxchg.h> |
338d4f49 | 38 | #include <asm/cpufeature.h> |
1d18c47c | 39 | #include <asm/exception.h> |
9a0c0328 | 40 | #include <asm/daifflags.h> |
1d18c47c | 41 | #include <asm/debug-monitors.h> |
9141300a | 42 | #include <asm/esr.h> |
338d4f49 | 43 | #include <asm/sysreg.h> |
1d18c47c CM |
44 | #include <asm/system_misc.h> |
45 | #include <asm/pgtable.h> | |
46 | #include <asm/tlbflush.h> | |
92ff0674 | 47 | #include <asm/traps.h> |
1d18c47c | 48 | |
7edda088 TB |
49 | #include <acpi/ghes.h> |
50 | ||
09a6adf5 VK |
51 | struct fault_info { |
52 | int (*fn)(unsigned long addr, unsigned int esr, | |
53 | struct pt_regs *regs); | |
54 | int sig; | |
55 | int code; | |
56 | const char *name; | |
57 | }; | |
58 | ||
59 | static const struct fault_info fault_info[]; | |
359048f9 | 60 | static struct fault_info debug_fault_info[]; |
09a6adf5 VK |
61 | |
62 | static inline const struct fault_info *esr_to_fault_info(unsigned int esr) | |
63 | { | |
00bbd5d9 | 64 | return fault_info + (esr & ESR_ELx_FSC); |
09a6adf5 | 65 | } |
3495386b | 66 | |
359048f9 AK |
67 | static inline const struct fault_info *esr_to_debug_fault_info(unsigned int esr) |
68 | { | |
69 | return debug_fault_info + DBG_ESR_EVT(esr); | |
70 | } | |
71 | ||
2dd0e8d2 SP |
72 | #ifdef CONFIG_KPROBES |
73 | static inline int notify_page_fault(struct pt_regs *regs, unsigned int esr) | |
74 | { | |
75 | int ret = 0; | |
76 | ||
77 | /* kprobe_running() needs smp_processor_id() */ | |
78 | if (!user_mode(regs)) { | |
79 | preempt_disable(); | |
80 | if (kprobe_running() && kprobe_fault_handler(regs, esr)) | |
81 | ret = 1; | |
82 | preempt_enable(); | |
83 | } | |
84 | ||
85 | return ret; | |
86 | } | |
87 | #else | |
88 | static inline int notify_page_fault(struct pt_regs *regs, unsigned int esr) | |
89 | { | |
90 | return 0; | |
91 | } | |
92 | #endif | |
93 | ||
1f9b8936 JT |
94 | static void data_abort_decode(unsigned int esr) |
95 | { | |
96 | pr_alert("Data abort info:\n"); | |
97 | ||
98 | if (esr & ESR_ELx_ISV) { | |
99 | pr_alert(" Access size = %u byte(s)\n", | |
100 | 1U << ((esr & ESR_ELx_SAS) >> ESR_ELx_SAS_SHIFT)); | |
101 | pr_alert(" SSE = %lu, SRT = %lu\n", | |
102 | (esr & ESR_ELx_SSE) >> ESR_ELx_SSE_SHIFT, | |
103 | (esr & ESR_ELx_SRT_MASK) >> ESR_ELx_SRT_SHIFT); | |
104 | pr_alert(" SF = %lu, AR = %lu\n", | |
105 | (esr & ESR_ELx_SF) >> ESR_ELx_SF_SHIFT, | |
106 | (esr & ESR_ELx_AR) >> ESR_ELx_AR_SHIFT); | |
107 | } else { | |
0a6de8b8 | 108 | pr_alert(" ISV = 0, ISS = 0x%08lx\n", esr & ESR_ELx_ISS_MASK); |
1f9b8936 JT |
109 | } |
110 | ||
111 | pr_alert(" CM = %lu, WnR = %lu\n", | |
112 | (esr & ESR_ELx_CM) >> ESR_ELx_CM_SHIFT, | |
113 | (esr & ESR_ELx_WNR) >> ESR_ELx_WNR_SHIFT); | |
114 | } | |
115 | ||
1f9b8936 JT |
116 | static void mem_abort_decode(unsigned int esr) |
117 | { | |
118 | pr_alert("Mem abort info:\n"); | |
119 | ||
42dbf54e | 120 | pr_alert(" ESR = 0x%08x\n", esr); |
1f9b8936 JT |
121 | pr_alert(" Exception class = %s, IL = %u bits\n", |
122 | esr_get_class_string(esr), | |
123 | (esr & ESR_ELx_IL) ? 32 : 16); | |
124 | pr_alert(" SET = %lu, FnV = %lu\n", | |
125 | (esr & ESR_ELx_SET_MASK) >> ESR_ELx_SET_SHIFT, | |
126 | (esr & ESR_ELx_FnV) >> ESR_ELx_FnV_SHIFT); | |
127 | pr_alert(" EA = %lu, S1PTW = %lu\n", | |
128 | (esr & ESR_ELx_EA) >> ESR_ELx_EA_SHIFT, | |
129 | (esr & ESR_ELx_S1PTW) >> ESR_ELx_S1PTW_SHIFT); | |
130 | ||
131 | if (esr_is_data_abort(esr)) | |
132 | data_abort_decode(esr); | |
133 | } | |
134 | ||
1d18c47c | 135 | /* |
67ce16ec | 136 | * Dump out the page tables associated with 'addr' in the currently active mm. |
1d18c47c | 137 | */ |
67ce16ec | 138 | void show_pte(unsigned long addr) |
1d18c47c | 139 | { |
67ce16ec | 140 | struct mm_struct *mm; |
20a004e7 WD |
141 | pgd_t *pgdp; |
142 | pgd_t pgd; | |
1d18c47c | 143 | |
67ce16ec KM |
144 | if (addr < TASK_SIZE) { |
145 | /* TTBR0 */ | |
146 | mm = current->active_mm; | |
147 | if (mm == &init_mm) { | |
148 | pr_alert("[%016lx] user address but active_mm is swapper\n", | |
149 | addr); | |
150 | return; | |
151 | } | |
152 | } else if (addr >= VA_START) { | |
153 | /* TTBR1 */ | |
1d18c47c | 154 | mm = &init_mm; |
67ce16ec KM |
155 | } else { |
156 | pr_alert("[%016lx] address between user and kernel address ranges\n", | |
157 | addr); | |
158 | return; | |
159 | } | |
1d18c47c | 160 | |
20a004e7 | 161 | pr_alert("%s pgtable: %luk pages, %u-bit VAs, pgdp = %p\n", |
1eb34b6e | 162 | mm == &init_mm ? "swapper" : "user", PAGE_SIZE / SZ_1K, |
67e7fdfc | 163 | mm == &init_mm ? VA_BITS : (int) vabits_user, mm->pgd); |
20a004e7 WD |
164 | pgdp = pgd_offset(mm, addr); |
165 | pgd = READ_ONCE(*pgdp); | |
166 | pr_alert("[%016lx] pgd=%016llx", addr, pgd_val(pgd)); | |
1d18c47c CM |
167 | |
168 | do { | |
20a004e7 WD |
169 | pud_t *pudp, pud; |
170 | pmd_t *pmdp, pmd; | |
171 | pte_t *ptep, pte; | |
1d18c47c | 172 | |
20a004e7 | 173 | if (pgd_none(pgd) || pgd_bad(pgd)) |
1d18c47c CM |
174 | break; |
175 | ||
20a004e7 WD |
176 | pudp = pud_offset(pgdp, addr); |
177 | pud = READ_ONCE(*pudp); | |
178 | pr_cont(", pud=%016llx", pud_val(pud)); | |
179 | if (pud_none(pud) || pud_bad(pud)) | |
1d18c47c CM |
180 | break; |
181 | ||
20a004e7 WD |
182 | pmdp = pmd_offset(pudp, addr); |
183 | pmd = READ_ONCE(*pmdp); | |
184 | pr_cont(", pmd=%016llx", pmd_val(pmd)); | |
185 | if (pmd_none(pmd) || pmd_bad(pmd)) | |
1d18c47c CM |
186 | break; |
187 | ||
20a004e7 WD |
188 | ptep = pte_offset_map(pmdp, addr); |
189 | pte = READ_ONCE(*ptep); | |
190 | pr_cont(", pte=%016llx", pte_val(pte)); | |
191 | pte_unmap(ptep); | |
1d18c47c CM |
192 | } while(0); |
193 | ||
6ef4fb38 | 194 | pr_cont("\n"); |
1d18c47c CM |
195 | } |
196 | ||
66dbd6e6 CM |
197 | /* |
198 | * This function sets the access flags (dirty, accessed), as well as write | |
199 | * permission, and only to a more permissive setting. | |
200 | * | |
201 | * It needs to cope with hardware update of the accessed/dirty state by other | |
202 | * agents in the system and can safely skip the __sync_icache_dcache() call as, | |
203 | * like set_pte_at(), the PTE is never changed from no-exec to exec here. | |
204 | * | |
205 | * Returns whether or not the PTE actually changed. | |
206 | */ | |
207 | int ptep_set_access_flags(struct vm_area_struct *vma, | |
208 | unsigned long address, pte_t *ptep, | |
209 | pte_t entry, int dirty) | |
210 | { | |
3bbf7157 | 211 | pteval_t old_pteval, pteval; |
20a004e7 | 212 | pte_t pte = READ_ONCE(*ptep); |
66dbd6e6 | 213 | |
20a004e7 | 214 | if (pte_same(pte, entry)) |
66dbd6e6 CM |
215 | return 0; |
216 | ||
217 | /* only preserve the access flags and write permission */ | |
73e86cb0 | 218 | pte_val(entry) &= PTE_RDONLY | PTE_AF | PTE_WRITE | PTE_DIRTY; |
66dbd6e6 CM |
219 | |
220 | /* | |
221 | * Setting the flags must be done atomically to avoid racing with the | |
6d332747 CM |
222 | * hardware update of the access/dirty state. The PTE_RDONLY bit must |
223 | * be set to the most permissive (lowest value) of *ptep and entry | |
224 | * (calculated as: a & b == ~(~a | ~b)). | |
66dbd6e6 | 225 | */ |
6d332747 | 226 | pte_val(entry) ^= PTE_RDONLY; |
20a004e7 | 227 | pteval = pte_val(pte); |
3bbf7157 CM |
228 | do { |
229 | old_pteval = pteval; | |
230 | pteval ^= PTE_RDONLY; | |
231 | pteval |= pte_val(entry); | |
232 | pteval ^= PTE_RDONLY; | |
233 | pteval = cmpxchg_relaxed(&pte_val(*ptep), old_pteval, pteval); | |
234 | } while (pteval != old_pteval); | |
66dbd6e6 CM |
235 | |
236 | flush_tlb_fix_spurious_fault(vma, address); | |
237 | return 1; | |
238 | } | |
66dbd6e6 | 239 | |
9adeb8e7 LA |
240 | static bool is_el1_instruction_abort(unsigned int esr) |
241 | { | |
242 | return ESR_ELx_EC(esr) == ESR_ELx_EC_IABT_CUR; | |
243 | } | |
244 | ||
dbfe3828 AK |
245 | static inline bool is_el1_permission_fault(unsigned long addr, unsigned int esr, |
246 | struct pt_regs *regs) | |
b824b930 SB |
247 | { |
248 | unsigned int ec = ESR_ELx_EC(esr); | |
249 | unsigned int fsc_type = esr & ESR_ELx_FSC_TYPE; | |
250 | ||
251 | if (ec != ESR_ELx_EC_DABT_CUR && ec != ESR_ELx_EC_IABT_CUR) | |
252 | return false; | |
253 | ||
254 | if (fsc_type == ESR_ELx_FSC_PERM) | |
255 | return true; | |
256 | ||
51369e39 | 257 | if (addr < TASK_SIZE && system_uses_ttbr0_pan()) |
b824b930 SB |
258 | return fsc_type == ESR_ELx_FSC_FAULT && |
259 | (regs->pstate & PSR_PAN_BIT); | |
260 | ||
261 | return false; | |
262 | } | |
263 | ||
c870f14e MR |
264 | static void die_kernel_fault(const char *msg, unsigned long addr, |
265 | unsigned int esr, struct pt_regs *regs) | |
266 | { | |
267 | bust_spinlocks(1); | |
268 | ||
269 | pr_alert("Unable to handle kernel %s at virtual address %016lx\n", msg, | |
270 | addr); | |
271 | ||
272 | mem_abort_decode(esr); | |
273 | ||
274 | show_pte(addr); | |
275 | die("Oops", regs, esr); | |
276 | bust_spinlocks(0); | |
277 | do_exit(SIGKILL); | |
278 | } | |
279 | ||
67ce16ec KM |
280 | static void __do_kernel_fault(unsigned long addr, unsigned int esr, |
281 | struct pt_regs *regs) | |
1d18c47c | 282 | { |
b824b930 SB |
283 | const char *msg; |
284 | ||
1d18c47c CM |
285 | /* |
286 | * Are we prepared to handle this kernel fault? | |
9adeb8e7 | 287 | * We are almost certainly not prepared to handle instruction faults. |
1d18c47c | 288 | */ |
9adeb8e7 | 289 | if (!is_el1_instruction_abort(esr) && fixup_exception(regs)) |
1d18c47c CM |
290 | return; |
291 | ||
dbfe3828 | 292 | if (is_el1_permission_fault(addr, esr, regs)) { |
b824b930 SB |
293 | if (esr & ESR_ELx_WNR) |
294 | msg = "write to read-only memory"; | |
295 | else | |
296 | msg = "read from unreadable memory"; | |
297 | } else if (addr < PAGE_SIZE) { | |
298 | msg = "NULL pointer dereference"; | |
299 | } else { | |
300 | msg = "paging request"; | |
301 | } | |
302 | ||
c870f14e | 303 | die_kernel_fault(msg, addr, esr, regs); |
1d18c47c CM |
304 | } |
305 | ||
f29ad209 | 306 | static void set_thread_esr(unsigned long address, unsigned int esr) |
1d18c47c | 307 | { |
f29ad209 | 308 | current->thread.fault_address = address; |
cc198460 PM |
309 | |
310 | /* | |
311 | * If the faulting address is in the kernel, we must sanitize the ESR. | |
312 | * From userspace's point of view, kernel-only mappings don't exist | |
313 | * at all, so we report them as level 0 translation faults. | |
314 | * (This is not quite the way that "no mapping there at all" behaves: | |
315 | * an alignment fault not caused by the memory type would take | |
316 | * precedence over translation fault for a real access to empty | |
317 | * space. Unfortunately we can't easily distinguish "alignment fault | |
318 | * not caused by memory type" from "alignment fault caused by memory | |
319 | * type", so we ignore this wrinkle and just return the translation | |
320 | * fault.) | |
321 | */ | |
322 | if (current->thread.fault_address >= TASK_SIZE) { | |
323 | switch (ESR_ELx_EC(esr)) { | |
324 | case ESR_ELx_EC_DABT_LOW: | |
325 | /* | |
326 | * These bits provide only information about the | |
327 | * faulting instruction, which userspace knows already. | |
328 | * We explicitly clear bits which are architecturally | |
329 | * RES0 in case they are given meanings in future. | |
330 | * We always report the ESR as if the fault was taken | |
331 | * to EL1 and so ISV and the bits in ISS[23:14] are | |
332 | * clear. (In fact it always will be a fault to EL1.) | |
333 | */ | |
334 | esr &= ESR_ELx_EC_MASK | ESR_ELx_IL | | |
335 | ESR_ELx_CM | ESR_ELx_WNR; | |
336 | esr |= ESR_ELx_FSC_FAULT; | |
337 | break; | |
338 | case ESR_ELx_EC_IABT_LOW: | |
339 | /* | |
340 | * Claim a level 0 translation fault. | |
341 | * All other bits are architecturally RES0 for faults | |
342 | * reported with that DFSC value, so we clear them. | |
343 | */ | |
344 | esr &= ESR_ELx_EC_MASK | ESR_ELx_IL; | |
345 | esr |= ESR_ELx_FSC_FAULT; | |
346 | break; | |
347 | default: | |
348 | /* | |
349 | * This should never happen (entry.S only brings us | |
350 | * into this code for insn and data aborts from a lower | |
351 | * exception level). Fail safe by not providing an ESR | |
352 | * context record at all. | |
353 | */ | |
354 | WARN(1, "ESR 0x%x is not DABT or IABT from EL0\n", esr); | |
355 | esr = 0; | |
356 | break; | |
357 | } | |
358 | } | |
359 | ||
92ff0674 | 360 | current->thread.fault_code = esr; |
1d18c47c CM |
361 | } |
362 | ||
59f67e16 | 363 | static void do_bad_area(unsigned long addr, unsigned int esr, struct pt_regs *regs) |
1d18c47c | 364 | { |
1d18c47c CM |
365 | /* |
366 | * If we are in kernel mode at this point, we have no context to | |
367 | * handle this fault with. | |
368 | */ | |
09a6adf5 | 369 | if (user_mode(regs)) { |
92ff0674 | 370 | const struct fault_info *inf = esr_to_fault_info(esr); |
3eb0f519 | 371 | |
effb093a | 372 | set_thread_esr(addr, esr); |
feca355b EB |
373 | arm64_force_sig_fault(inf->sig, inf->code, (void __user *)addr, |
374 | inf->name); | |
92ff0674 | 375 | } else { |
67ce16ec | 376 | __do_kernel_fault(addr, esr, regs); |
92ff0674 | 377 | } |
1d18c47c CM |
378 | } |
379 | ||
380 | #define VM_FAULT_BADMAP 0x010000 | |
381 | #define VM_FAULT_BADACCESS 0x020000 | |
382 | ||
50a7ca3c | 383 | static vm_fault_t __do_page_fault(struct mm_struct *mm, unsigned long addr, |
db6f4106 | 384 | unsigned int mm_flags, unsigned long vm_flags, |
1d18c47c CM |
385 | struct task_struct *tsk) |
386 | { | |
387 | struct vm_area_struct *vma; | |
50a7ca3c | 388 | vm_fault_t fault; |
1d18c47c CM |
389 | |
390 | vma = find_vma(mm, addr); | |
391 | fault = VM_FAULT_BADMAP; | |
392 | if (unlikely(!vma)) | |
393 | goto out; | |
394 | if (unlikely(vma->vm_start > addr)) | |
395 | goto check_stack; | |
396 | ||
397 | /* | |
398 | * Ok, we have a good vm_area for this memory access, so we can handle | |
399 | * it. | |
400 | */ | |
401 | good_area: | |
db6f4106 WD |
402 | /* |
403 | * Check that the permissions on the VMA allow for the fault which | |
cab15ce6 | 404 | * occurred. |
db6f4106 WD |
405 | */ |
406 | if (!(vma->vm_flags & vm_flags)) { | |
1d18c47c CM |
407 | fault = VM_FAULT_BADACCESS; |
408 | goto out; | |
409 | } | |
410 | ||
dcddffd4 | 411 | return handle_mm_fault(vma, addr & PAGE_MASK, mm_flags); |
1d18c47c CM |
412 | |
413 | check_stack: | |
414 | if (vma->vm_flags & VM_GROWSDOWN && !expand_stack(vma, addr)) | |
415 | goto good_area; | |
416 | out: | |
417 | return fault; | |
418 | } | |
419 | ||
541ec870 MR |
420 | static bool is_el0_instruction_abort(unsigned int esr) |
421 | { | |
422 | return ESR_ELx_EC(esr) == ESR_ELx_EC_IABT_LOW; | |
423 | } | |
424 | ||
1d18c47c CM |
425 | static int __kprobes do_page_fault(unsigned long addr, unsigned int esr, |
426 | struct pt_regs *regs) | |
427 | { | |
2d2837fa | 428 | const struct fault_info *inf; |
1d18c47c CM |
429 | struct task_struct *tsk; |
430 | struct mm_struct *mm; | |
50a7ca3c | 431 | vm_fault_t fault, major = 0; |
cab15ce6 | 432 | unsigned long vm_flags = VM_READ | VM_WRITE; |
db6f4106 WD |
433 | unsigned int mm_flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE; |
434 | ||
2dd0e8d2 SP |
435 | if (notify_page_fault(regs, esr)) |
436 | return 0; | |
437 | ||
1d18c47c CM |
438 | tsk = current; |
439 | mm = tsk->mm; | |
440 | ||
1d18c47c CM |
441 | /* |
442 | * If we're in an interrupt or have no user context, we must not take | |
443 | * the fault. | |
444 | */ | |
70ffdb93 | 445 | if (faulthandler_disabled() || !mm) |
1d18c47c CM |
446 | goto no_context; |
447 | ||
759496ba JW |
448 | if (user_mode(regs)) |
449 | mm_flags |= FAULT_FLAG_USER; | |
450 | ||
541ec870 | 451 | if (is_el0_instruction_abort(esr)) { |
759496ba | 452 | vm_flags = VM_EXEC; |
aed40e01 | 453 | } else if ((esr & ESR_ELx_WNR) && !(esr & ESR_ELx_CM)) { |
759496ba JW |
454 | vm_flags = VM_WRITE; |
455 | mm_flags |= FAULT_FLAG_WRITE; | |
456 | } | |
457 | ||
dbfe3828 | 458 | if (addr < TASK_SIZE && is_el1_permission_fault(addr, esr, regs)) { |
e19a6ee2 JM |
459 | /* regs->orig_addr_limit may be 0 if we entered from EL0 */ |
460 | if (regs->orig_addr_limit == KERNEL_DS) | |
c870f14e MR |
461 | die_kernel_fault("access to user memory with fs=KERNEL_DS", |
462 | addr, esr, regs); | |
70544196 | 463 | |
9adeb8e7 | 464 | if (is_el1_instruction_abort(esr)) |
c870f14e MR |
465 | die_kernel_fault("execution of user memory", |
466 | addr, esr, regs); | |
9adeb8e7 | 467 | |
57f4959b | 468 | if (!search_exception_tables(regs->pc)) |
c870f14e MR |
469 | die_kernel_fault("access to user memory outside uaccess routines", |
470 | addr, esr, regs); | |
57f4959b | 471 | } |
338d4f49 | 472 | |
0e3a9026 PA |
473 | perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, addr); |
474 | ||
1d18c47c CM |
475 | /* |
476 | * As per x86, we may deadlock here. However, since the kernel only | |
477 | * validly references user space from well defined areas of the code, | |
478 | * we can bug out early if this is from code which shouldn't. | |
479 | */ | |
480 | if (!down_read_trylock(&mm->mmap_sem)) { | |
481 | if (!user_mode(regs) && !search_exception_tables(regs->pc)) | |
482 | goto no_context; | |
483 | retry: | |
484 | down_read(&mm->mmap_sem); | |
485 | } else { | |
486 | /* | |
487 | * The above down_read_trylock() might have succeeded in which | |
488 | * case, we'll have missed the might_sleep() from down_read(). | |
489 | */ | |
490 | might_sleep(); | |
491 | #ifdef CONFIG_DEBUG_VM | |
492 | if (!user_mode(regs) && !search_exception_tables(regs->pc)) | |
493 | goto no_context; | |
494 | #endif | |
495 | } | |
496 | ||
db6f4106 | 497 | fault = __do_page_fault(mm, addr, mm_flags, vm_flags, tsk); |
0e3a9026 | 498 | major |= fault & VM_FAULT_MAJOR; |
1d18c47c | 499 | |
0e3a9026 PA |
500 | if (fault & VM_FAULT_RETRY) { |
501 | /* | |
502 | * If we need to retry but a fatal signal is pending, | |
503 | * handle the signal first. We do not need to release | |
504 | * the mmap_sem because it would already be released | |
505 | * in __lock_page_or_retry in mm/filemap.c. | |
506 | */ | |
289d07a2 MR |
507 | if (fatal_signal_pending(current)) { |
508 | if (!user_mode(regs)) | |
509 | goto no_context; | |
0e3a9026 | 510 | return 0; |
289d07a2 | 511 | } |
0e3a9026 PA |
512 | |
513 | /* | |
514 | * Clear FAULT_FLAG_ALLOW_RETRY to avoid any risk of | |
515 | * starvation. | |
516 | */ | |
517 | if (mm_flags & FAULT_FLAG_ALLOW_RETRY) { | |
518 | mm_flags &= ~FAULT_FLAG_ALLOW_RETRY; | |
519 | mm_flags |= FAULT_FLAG_TRIED; | |
520 | goto retry; | |
521 | } | |
522 | } | |
523 | up_read(&mm->mmap_sem); | |
1d18c47c CM |
524 | |
525 | /* | |
0e3a9026 | 526 | * Handle the "normal" (no error) case first. |
1d18c47c | 527 | */ |
0e3a9026 PA |
528 | if (likely(!(fault & (VM_FAULT_ERROR | VM_FAULT_BADMAP | |
529 | VM_FAULT_BADACCESS)))) { | |
530 | /* | |
531 | * Major/minor page fault accounting is only done | |
532 | * once. If we go through a retry, it is extremely | |
533 | * likely that the page will be found in page cache at | |
534 | * that point. | |
535 | */ | |
536 | if (major) { | |
1d18c47c CM |
537 | tsk->maj_flt++; |
538 | perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1, regs, | |
539 | addr); | |
540 | } else { | |
541 | tsk->min_flt++; | |
542 | perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, 1, regs, | |
543 | addr); | |
544 | } | |
1d18c47c | 545 | |
1d18c47c | 546 | return 0; |
0e3a9026 | 547 | } |
1d18c47c | 548 | |
87134102 JW |
549 | /* |
550 | * If we are in kernel mode at this point, we have no context to | |
551 | * handle this fault with. | |
552 | */ | |
553 | if (!user_mode(regs)) | |
554 | goto no_context; | |
555 | ||
1d18c47c CM |
556 | if (fault & VM_FAULT_OOM) { |
557 | /* | |
558 | * We ran out of memory, call the OOM killer, and return to | |
559 | * userspace (which will retry the fault, or kill us if we got | |
560 | * oom-killed). | |
561 | */ | |
562 | pagefault_out_of_memory(); | |
563 | return 0; | |
564 | } | |
565 | ||
2d2837fa | 566 | inf = esr_to_fault_info(esr); |
559d8d91 | 567 | set_thread_esr(addr, esr); |
1d18c47c CM |
568 | if (fault & VM_FAULT_SIGBUS) { |
569 | /* | |
570 | * We had some memory, but were unable to successfully fix up | |
571 | * this page fault. | |
572 | */ | |
feca355b EB |
573 | arm64_force_sig_fault(SIGBUS, BUS_ADRERR, (void __user *)addr, |
574 | inf->name); | |
9ea3a974 EB |
575 | } else if (fault & (VM_FAULT_HWPOISON_LARGE | VM_FAULT_HWPOISON)) { |
576 | unsigned int lsb; | |
577 | ||
578 | lsb = PAGE_SHIFT; | |
579 | if (fault & VM_FAULT_HWPOISON_LARGE) | |
580 | lsb = hstate_index_to_shift(VM_FAULT_GET_HINDEX(fault)); | |
92ff0674 | 581 | |
b4d5557c EB |
582 | arm64_force_sig_mceerr(BUS_MCEERR_AR, (void __user *)addr, lsb, |
583 | inf->name); | |
1d18c47c CM |
584 | } else { |
585 | /* | |
586 | * Something tried to access memory that isn't in our memory | |
587 | * map. | |
588 | */ | |
feca355b EB |
589 | arm64_force_sig_fault(SIGSEGV, |
590 | fault == VM_FAULT_BADACCESS ? SEGV_ACCERR : SEGV_MAPERR, | |
591 | (void __user *)addr, | |
592 | inf->name); | |
1d18c47c CM |
593 | } |
594 | ||
1d18c47c CM |
595 | return 0; |
596 | ||
597 | no_context: | |
67ce16ec | 598 | __do_kernel_fault(addr, esr, regs); |
1d18c47c CM |
599 | return 0; |
600 | } | |
601 | ||
1d18c47c CM |
602 | static int __kprobes do_translation_fault(unsigned long addr, |
603 | unsigned int esr, | |
604 | struct pt_regs *regs) | |
605 | { | |
606 | if (addr < TASK_SIZE) | |
607 | return do_page_fault(addr, esr, regs); | |
608 | ||
609 | do_bad_area(addr, esr, regs); | |
610 | return 0; | |
611 | } | |
612 | ||
52d7523d EL |
613 | static int do_alignment_fault(unsigned long addr, unsigned int esr, |
614 | struct pt_regs *regs) | |
615 | { | |
616 | do_bad_area(addr, esr, regs); | |
617 | return 0; | |
618 | } | |
619 | ||
1d18c47c CM |
620 | static int do_bad(unsigned long addr, unsigned int esr, struct pt_regs *regs) |
621 | { | |
f67d5c4f | 622 | return 1; /* "fault" */ |
1d18c47c CM |
623 | } |
624 | ||
32015c23 TB |
625 | static int do_sea(unsigned long addr, unsigned int esr, struct pt_regs *regs) |
626 | { | |
32015c23 | 627 | const struct fault_info *inf; |
6fa998e8 | 628 | void __user *siaddr; |
32015c23 TB |
629 | |
630 | inf = esr_to_fault_info(esr); | |
32015c23 | 631 | |
7edda088 TB |
632 | /* |
633 | * Synchronous aborts may interrupt code which had interrupts masked. | |
634 | * Before calling out into the wider kernel tell the interested | |
635 | * subsystems. | |
636 | */ | |
637 | if (IS_ENABLED(CONFIG_ACPI_APEI_SEA)) { | |
638 | if (interrupts_enabled(regs)) | |
639 | nmi_enter(); | |
640 | ||
faa75e14 | 641 | ghes_notify_sea(); |
7edda088 TB |
642 | |
643 | if (interrupts_enabled(regs)) | |
644 | nmi_exit(); | |
645 | } | |
646 | ||
32015c23 | 647 | if (esr & ESR_ELx_FnV) |
6fa998e8 | 648 | siaddr = NULL; |
32015c23 | 649 | else |
6fa998e8 EB |
650 | siaddr = (void __user *)addr; |
651 | arm64_notify_die(inf->name, regs, inf->sig, inf->code, siaddr, esr); | |
32015c23 | 652 | |
faa75e14 | 653 | return 0; |
32015c23 TB |
654 | } |
655 | ||
09a6adf5 | 656 | static const struct fault_info fault_info[] = { |
af40ff68 DM |
657 | { do_bad, SIGKILL, SI_KERNEL, "ttbr address size fault" }, |
658 | { do_bad, SIGKILL, SI_KERNEL, "level 1 address size fault" }, | |
659 | { do_bad, SIGKILL, SI_KERNEL, "level 2 address size fault" }, | |
660 | { do_bad, SIGKILL, SI_KERNEL, "level 3 address size fault" }, | |
7f73f7ae | 661 | { do_translation_fault, SIGSEGV, SEGV_MAPERR, "level 0 translation fault" }, |
1d18c47c CM |
662 | { do_translation_fault, SIGSEGV, SEGV_MAPERR, "level 1 translation fault" }, |
663 | { do_translation_fault, SIGSEGV, SEGV_MAPERR, "level 2 translation fault" }, | |
760bfb47 | 664 | { do_translation_fault, SIGSEGV, SEGV_MAPERR, "level 3 translation fault" }, |
af40ff68 | 665 | { do_bad, SIGKILL, SI_KERNEL, "unknown 8" }, |
084bd298 SC |
666 | { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 1 access flag fault" }, |
667 | { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 2 access flag fault" }, | |
1d18c47c | 668 | { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 3 access flag fault" }, |
af40ff68 | 669 | { do_bad, SIGKILL, SI_KERNEL, "unknown 12" }, |
084bd298 SC |
670 | { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 1 permission fault" }, |
671 | { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 2 permission fault" }, | |
1d18c47c | 672 | { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 3 permission fault" }, |
af40ff68 DM |
673 | { do_sea, SIGBUS, BUS_OBJERR, "synchronous external abort" }, |
674 | { do_bad, SIGKILL, SI_KERNEL, "unknown 17" }, | |
675 | { do_bad, SIGKILL, SI_KERNEL, "unknown 18" }, | |
676 | { do_bad, SIGKILL, SI_KERNEL, "unknown 19" }, | |
677 | { do_sea, SIGKILL, SI_KERNEL, "level 0 (translation table walk)" }, | |
678 | { do_sea, SIGKILL, SI_KERNEL, "level 1 (translation table walk)" }, | |
679 | { do_sea, SIGKILL, SI_KERNEL, "level 2 (translation table walk)" }, | |
680 | { do_sea, SIGKILL, SI_KERNEL, "level 3 (translation table walk)" }, | |
681 | { do_sea, SIGBUS, BUS_OBJERR, "synchronous parity or ECC error" }, // Reserved when RAS is implemented | |
682 | { do_bad, SIGKILL, SI_KERNEL, "unknown 25" }, | |
683 | { do_bad, SIGKILL, SI_KERNEL, "unknown 26" }, | |
684 | { do_bad, SIGKILL, SI_KERNEL, "unknown 27" }, | |
685 | { do_sea, SIGKILL, SI_KERNEL, "level 0 synchronous parity error (translation table walk)" }, // Reserved when RAS is implemented | |
686 | { do_sea, SIGKILL, SI_KERNEL, "level 1 synchronous parity error (translation table walk)" }, // Reserved when RAS is implemented | |
687 | { do_sea, SIGKILL, SI_KERNEL, "level 2 synchronous parity error (translation table walk)" }, // Reserved when RAS is implemented | |
688 | { do_sea, SIGKILL, SI_KERNEL, "level 3 synchronous parity error (translation table walk)" }, // Reserved when RAS is implemented | |
689 | { do_bad, SIGKILL, SI_KERNEL, "unknown 32" }, | |
52d7523d | 690 | { do_alignment_fault, SIGBUS, BUS_ADRALN, "alignment fault" }, |
af40ff68 DM |
691 | { do_bad, SIGKILL, SI_KERNEL, "unknown 34" }, |
692 | { do_bad, SIGKILL, SI_KERNEL, "unknown 35" }, | |
693 | { do_bad, SIGKILL, SI_KERNEL, "unknown 36" }, | |
694 | { do_bad, SIGKILL, SI_KERNEL, "unknown 37" }, | |
695 | { do_bad, SIGKILL, SI_KERNEL, "unknown 38" }, | |
696 | { do_bad, SIGKILL, SI_KERNEL, "unknown 39" }, | |
697 | { do_bad, SIGKILL, SI_KERNEL, "unknown 40" }, | |
698 | { do_bad, SIGKILL, SI_KERNEL, "unknown 41" }, | |
699 | { do_bad, SIGKILL, SI_KERNEL, "unknown 42" }, | |
700 | { do_bad, SIGKILL, SI_KERNEL, "unknown 43" }, | |
701 | { do_bad, SIGKILL, SI_KERNEL, "unknown 44" }, | |
702 | { do_bad, SIGKILL, SI_KERNEL, "unknown 45" }, | |
703 | { do_bad, SIGKILL, SI_KERNEL, "unknown 46" }, | |
704 | { do_bad, SIGKILL, SI_KERNEL, "unknown 47" }, | |
705 | { do_bad, SIGKILL, SI_KERNEL, "TLB conflict abort" }, | |
706 | { do_bad, SIGKILL, SI_KERNEL, "Unsupported atomic hardware update fault" }, | |
707 | { do_bad, SIGKILL, SI_KERNEL, "unknown 50" }, | |
708 | { do_bad, SIGKILL, SI_KERNEL, "unknown 51" }, | |
709 | { do_bad, SIGKILL, SI_KERNEL, "implementation fault (lockdown abort)" }, | |
710 | { do_bad, SIGBUS, BUS_OBJERR, "implementation fault (unsupported exclusive)" }, | |
711 | { do_bad, SIGKILL, SI_KERNEL, "unknown 54" }, | |
712 | { do_bad, SIGKILL, SI_KERNEL, "unknown 55" }, | |
713 | { do_bad, SIGKILL, SI_KERNEL, "unknown 56" }, | |
714 | { do_bad, SIGKILL, SI_KERNEL, "unknown 57" }, | |
715 | { do_bad, SIGKILL, SI_KERNEL, "unknown 58" }, | |
716 | { do_bad, SIGKILL, SI_KERNEL, "unknown 59" }, | |
717 | { do_bad, SIGKILL, SI_KERNEL, "unknown 60" }, | |
718 | { do_bad, SIGKILL, SI_KERNEL, "section domain fault" }, | |
719 | { do_bad, SIGKILL, SI_KERNEL, "page domain fault" }, | |
720 | { do_bad, SIGKILL, SI_KERNEL, "unknown 63" }, | |
1d18c47c CM |
721 | }; |
722 | ||
621f48e4 TB |
723 | int handle_guest_sea(phys_addr_t addr, unsigned int esr) |
724 | { | |
1035a078 | 725 | return ghes_notify_sea(); |
621f48e4 TB |
726 | } |
727 | ||
1d18c47c CM |
728 | asmlinkage void __exception do_mem_abort(unsigned long addr, unsigned int esr, |
729 | struct pt_regs *regs) | |
730 | { | |
09a6adf5 | 731 | const struct fault_info *inf = esr_to_fault_info(esr); |
1d18c47c CM |
732 | |
733 | if (!inf->fn(addr, esr, regs)) | |
734 | return; | |
735 | ||
1049c308 WD |
736 | if (!user_mode(regs)) { |
737 | pr_alert("Unhandled fault at 0x%016lx\n", addr); | |
738 | mem_abort_decode(esr); | |
80b6eb04 | 739 | show_pte(addr); |
1049c308 | 740 | } |
42dbf54e | 741 | |
6fa998e8 EB |
742 | arm64_notify_die(inf->name, regs, |
743 | inf->sig, inf->code, (void __user *)addr, esr); | |
1d18c47c CM |
744 | } |
745 | ||
30d88c0e WD |
746 | asmlinkage void __exception do_el0_irq_bp_hardening(void) |
747 | { | |
748 | /* PC has already been checked in entry.S */ | |
749 | arm64_apply_bp_hardening(); | |
750 | } | |
751 | ||
0f15adbb WD |
752 | asmlinkage void __exception do_el0_ia_bp_hardening(unsigned long addr, |
753 | unsigned int esr, | |
754 | struct pt_regs *regs) | |
755 | { | |
756 | /* | |
757 | * We've taken an instruction abort from userspace and not yet | |
758 | * re-enabled IRQs. If the address is a kernel address, apply | |
759 | * BP hardening prior to enabling IRQs and pre-emption. | |
760 | */ | |
761 | if (addr > TASK_SIZE) | |
762 | arm64_apply_bp_hardening(); | |
763 | ||
9a0c0328 | 764 | local_daif_restore(DAIF_PROCCTX); |
0f15adbb WD |
765 | do_mem_abort(addr, esr, regs); |
766 | } | |
767 | ||
768 | ||
1d18c47c CM |
769 | asmlinkage void __exception do_sp_pc_abort(unsigned long addr, |
770 | unsigned int esr, | |
771 | struct pt_regs *regs) | |
772 | { | |
5dfc6ed2 WD |
773 | if (user_mode(regs)) { |
774 | if (instruction_pointer(regs) > TASK_SIZE) | |
775 | arm64_apply_bp_hardening(); | |
9a0c0328 | 776 | local_daif_restore(DAIF_PROCCTX); |
5dfc6ed2 WD |
777 | } |
778 | ||
6fa998e8 EB |
779 | arm64_notify_die("SP/PC alignment exception", regs, |
780 | SIGBUS, BUS_ADRALN, (void __user *)addr, esr); | |
1d18c47c CM |
781 | } |
782 | ||
9fb7410f DM |
783 | int __init early_brk64(unsigned long addr, unsigned int esr, |
784 | struct pt_regs *regs); | |
785 | ||
786 | /* | |
787 | * __refdata because early_brk64 is __init, but the reference to it is | |
788 | * clobbered at arch_initcall time. | |
789 | * See traps.c and debug-monitors.c:debug_traps_init(). | |
790 | */ | |
791 | static struct fault_info __refdata debug_fault_info[] = { | |
1d18c47c CM |
792 | { do_bad, SIGTRAP, TRAP_HWBKPT, "hardware breakpoint" }, |
793 | { do_bad, SIGTRAP, TRAP_HWBKPT, "hardware single-step" }, | |
794 | { do_bad, SIGTRAP, TRAP_HWBKPT, "hardware watchpoint" }, | |
af40ff68 | 795 | { do_bad, SIGKILL, SI_KERNEL, "unknown 3" }, |
1d18c47c | 796 | { do_bad, SIGTRAP, TRAP_BRKPT, "aarch32 BKPT" }, |
af40ff68 | 797 | { do_bad, SIGKILL, SI_KERNEL, "aarch32 vector catch" }, |
9fb7410f | 798 | { early_brk64, SIGTRAP, TRAP_BRKPT, "aarch64 BRK" }, |
af40ff68 | 799 | { do_bad, SIGKILL, SI_KERNEL, "unknown 7" }, |
1d18c47c CM |
800 | }; |
801 | ||
802 | void __init hook_debug_fault_code(int nr, | |
803 | int (*fn)(unsigned long, unsigned int, struct pt_regs *), | |
804 | int sig, int code, const char *name) | |
805 | { | |
806 | BUG_ON(nr < 0 || nr >= ARRAY_SIZE(debug_fault_info)); | |
807 | ||
808 | debug_fault_info[nr].fn = fn; | |
809 | debug_fault_info[nr].sig = sig; | |
810 | debug_fault_info[nr].code = code; | |
811 | debug_fault_info[nr].name = name; | |
812 | } | |
813 | ||
814 | asmlinkage int __exception do_debug_exception(unsigned long addr, | |
815 | unsigned int esr, | |
816 | struct pt_regs *regs) | |
817 | { | |
359048f9 | 818 | const struct fault_info *inf = esr_to_debug_fault_info(esr); |
6afedcd2 | 819 | int rv; |
1d18c47c | 820 | |
6afedcd2 JM |
821 | /* |
822 | * Tell lockdep we disabled irqs in entry.S. Do nothing if they were | |
823 | * already disabled to preserve the last enabled/disabled addresses. | |
824 | */ | |
825 | if (interrupts_enabled(regs)) | |
826 | trace_hardirqs_off(); | |
1d18c47c | 827 | |
5dfc6ed2 WD |
828 | if (user_mode(regs) && instruction_pointer(regs) > TASK_SIZE) |
829 | arm64_apply_bp_hardening(); | |
830 | ||
6afedcd2 JM |
831 | if (!inf->fn(addr, esr, regs)) { |
832 | rv = 1; | |
833 | } else { | |
6fa998e8 EB |
834 | arm64_notify_die(inf->name, regs, |
835 | inf->sig, inf->code, (void __user *)addr, esr); | |
6afedcd2 JM |
836 | rv = 0; |
837 | } | |
1d18c47c | 838 | |
6afedcd2 JM |
839 | if (interrupts_enabled(regs)) |
840 | trace_hardirqs_on(); | |
1d18c47c | 841 | |
6afedcd2 | 842 | return rv; |
1d18c47c | 843 | } |
2dd0e8d2 | 844 | NOKPROBE_SYMBOL(do_debug_exception); |