1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * S390 version
4 * Copyright IBM Corp. 1999
5 * Author(s): Hartmut Penner (hp@de.ibm.com)
6 * Ulrich Weigand (uweigand@de.ibm.com)
7 *
8 * Derived from "arch/i386/mm/fault.c"
9 * Copyright (C) 1995 Linus Torvalds
10 */
11
12 #include <linux/kernel_stat.h>
13 #include <linux/perf_event.h>
14 #include <linux/signal.h>
15 #include <linux/sched.h>
16 #include <linux/sched/debug.h>
17 #include <linux/kernel.h>
18 #include <linux/errno.h>
19 #include <linux/string.h>
20 #include <linux/types.h>
21 #include <linux/ptrace.h>
22 #include <linux/mman.h>
23 #include <linux/mm.h>
24 #include <linux/compat.h>
25 #include <linux/smp.h>
26 #include <linux/kdebug.h>
27 #include <linux/init.h>
28 #include <linux/console.h>
29 #include <linux/extable.h>
30 #include <linux/hardirq.h>
31 #include <linux/kprobes.h>
32 #include <linux/uaccess.h>
33 #include <linux/hugetlb.h>
34 #include <linux/kfence.h>
35 #include <asm/asm-extable.h>
36 #include <asm/asm-offsets.h>
37 #include <asm/diag.h>
38 #include <asm/gmap.h>
39 #include <asm/irq.h>
40 #include <asm/mmu_context.h>
41 #include <asm/facility.h>
42 #include <asm/uv.h>
43 #include "../kernel/entry.h"
44
45 #define __FAIL_ADDR_MASK -4096L
46
47 /*
48 * Allocate private vm_fault_reason from top. Please make sure it won't
49 * collide with vm_fault_reason.
50 */
51 #define VM_FAULT_BADCONTEXT ((__force vm_fault_t)0x80000000)
52 #define VM_FAULT_BADMAP ((__force vm_fault_t)0x40000000)
53 #define VM_FAULT_BADACCESS ((__force vm_fault_t)0x20000000)
54 #define VM_FAULT_SIGNAL ((__force vm_fault_t)0x10000000)
55 #define VM_FAULT_PFAULT ((__force vm_fault_t)0x8000000)
56
57 enum fault_type {
58 KERNEL_FAULT,
59 USER_FAULT,
60 GMAP_FAULT,
61 };
62
63 static unsigned long store_indication __read_mostly;
64
fault_init(void)65 static int __init fault_init(void)
66 {
67 if (test_facility(75))
68 store_indication = 0xc00;
69 return 0;
70 }
71 early_initcall(fault_init);
72
73 /*
74 * Find out which address space caused the exception.
75 */
get_fault_type(struct pt_regs * regs)76 static enum fault_type get_fault_type(struct pt_regs *regs)
77 {
78 unsigned long trans_exc_code;
79
80 trans_exc_code = regs->int_parm_long & 3;
81 if (likely(trans_exc_code == 0)) {
82 /* primary space exception */
83 if (user_mode(regs))
84 return USER_FAULT;
85 if (!IS_ENABLED(CONFIG_PGSTE))
86 return KERNEL_FAULT;
87 if (test_pt_regs_flag(regs, PIF_GUEST_FAULT))
88 return GMAP_FAULT;
89 return KERNEL_FAULT;
90 }
91 if (trans_exc_code == 2)
92 return USER_FAULT;
93 if (trans_exc_code == 1) {
94 /* access register mode, not used in the kernel */
95 return USER_FAULT;
96 }
97 /* home space exception -> access via kernel ASCE */
98 return KERNEL_FAULT;
99 }
100
get_fault_address(struct pt_regs * regs)101 static unsigned long get_fault_address(struct pt_regs *regs)
102 {
103 unsigned long trans_exc_code = regs->int_parm_long;
104
105 return trans_exc_code & __FAIL_ADDR_MASK;
106 }
107
fault_is_write(struct pt_regs * regs)108 static bool fault_is_write(struct pt_regs *regs)
109 {
110 unsigned long trans_exc_code = regs->int_parm_long;
111
112 return (trans_exc_code & store_indication) == 0x400;
113 }
114
bad_address(void * p)115 static int bad_address(void *p)
116 {
117 unsigned long dummy;
118
119 return get_kernel_nofault(dummy, (unsigned long *)p);
120 }
121
dump_pagetable(unsigned long asce,unsigned long address)122 static void dump_pagetable(unsigned long asce, unsigned long address)
123 {
124 unsigned long *table = __va(asce & _ASCE_ORIGIN);
125
126 pr_alert("AS:%016lx ", asce);
127 switch (asce & _ASCE_TYPE_MASK) {
128 case _ASCE_TYPE_REGION1:
129 table += (address & _REGION1_INDEX) >> _REGION1_SHIFT;
130 if (bad_address(table))
131 goto bad;
132 pr_cont("R1:%016lx ", *table);
133 if (*table & _REGION_ENTRY_INVALID)
134 goto out;
135 table = __va(*table & _REGION_ENTRY_ORIGIN);
136 fallthrough;
137 case _ASCE_TYPE_REGION2:
138 table += (address & _REGION2_INDEX) >> _REGION2_SHIFT;
139 if (bad_address(table))
140 goto bad;
141 pr_cont("R2:%016lx ", *table);
142 if (*table & _REGION_ENTRY_INVALID)
143 goto out;
144 table = __va(*table & _REGION_ENTRY_ORIGIN);
145 fallthrough;
146 case _ASCE_TYPE_REGION3:
147 table += (address & _REGION3_INDEX) >> _REGION3_SHIFT;
148 if (bad_address(table))
149 goto bad;
150 pr_cont("R3:%016lx ", *table);
151 if (*table & (_REGION_ENTRY_INVALID | _REGION3_ENTRY_LARGE))
152 goto out;
153 table = __va(*table & _REGION_ENTRY_ORIGIN);
154 fallthrough;
155 case _ASCE_TYPE_SEGMENT:
156 table += (address & _SEGMENT_INDEX) >> _SEGMENT_SHIFT;
157 if (bad_address(table))
158 goto bad;
159 pr_cont("S:%016lx ", *table);
160 if (*table & (_SEGMENT_ENTRY_INVALID | _SEGMENT_ENTRY_LARGE))
161 goto out;
162 table = __va(*table & _SEGMENT_ENTRY_ORIGIN);
163 }
164 table += (address & _PAGE_INDEX) >> _PAGE_SHIFT;
165 if (bad_address(table))
166 goto bad;
167 pr_cont("P:%016lx ", *table);
168 out:
169 pr_cont("\n");
170 return;
171 bad:
172 pr_cont("BAD\n");
173 }
174
dump_fault_info(struct pt_regs * regs)175 static void dump_fault_info(struct pt_regs *regs)
176 {
177 unsigned long asce;
178
179 pr_alert("Failing address: %016lx TEID: %016lx\n",
180 regs->int_parm_long & __FAIL_ADDR_MASK, regs->int_parm_long);
181 pr_alert("Fault in ");
182 switch (regs->int_parm_long & 3) {
183 case 3:
184 pr_cont("home space ");
185 break;
186 case 2:
187 pr_cont("secondary space ");
188 break;
189 case 1:
190 pr_cont("access register ");
191 break;
192 case 0:
193 pr_cont("primary space ");
194 break;
195 }
196 pr_cont("mode while using ");
197 switch (get_fault_type(regs)) {
198 case USER_FAULT:
199 asce = S390_lowcore.user_asce;
200 pr_cont("user ");
201 break;
202 case GMAP_FAULT:
203 asce = ((struct gmap *) S390_lowcore.gmap)->asce;
204 pr_cont("gmap ");
205 break;
206 case KERNEL_FAULT:
207 asce = S390_lowcore.kernel_asce;
208 pr_cont("kernel ");
209 break;
210 default:
211 unreachable();
212 }
213 pr_cont("ASCE.\n");
214 dump_pagetable(asce, regs->int_parm_long & __FAIL_ADDR_MASK);
215 }
216
217 int show_unhandled_signals = 1;
218
report_user_fault(struct pt_regs * regs,long signr,int is_mm_fault)219 void report_user_fault(struct pt_regs *regs, long signr, int is_mm_fault)
220 {
221 if ((task_pid_nr(current) > 1) && !show_unhandled_signals)
222 return;
223 if (!unhandled_signal(current, signr))
224 return;
225 if (!printk_ratelimit())
226 return;
227 printk(KERN_ALERT "User process fault: interruption code %04x ilc:%d ",
228 regs->int_code & 0xffff, regs->int_code >> 17);
229 print_vma_addr(KERN_CONT "in ", regs->psw.addr);
230 printk(KERN_CONT "\n");
231 if (is_mm_fault)
232 dump_fault_info(regs);
233 show_regs(regs);
234 }
235
236 /*
237 * Send SIGSEGV to task. This is an external routine
238 * to keep the stack usage of do_page_fault small.
239 */
do_sigsegv(struct pt_regs * regs,int si_code)240 static noinline void do_sigsegv(struct pt_regs *regs, int si_code)
241 {
242 report_user_fault(regs, SIGSEGV, 1);
243 force_sig_fault(SIGSEGV, si_code,
244 (void __user *)(regs->int_parm_long & __FAIL_ADDR_MASK));
245 }
246
do_no_context(struct pt_regs * regs,vm_fault_t fault)247 static noinline void do_no_context(struct pt_regs *regs, vm_fault_t fault)
248 {
249 enum fault_type fault_type;
250 unsigned long address;
251 bool is_write;
252
253 if (fixup_exception(regs))
254 return;
255 fault_type = get_fault_type(regs);
256 if ((fault_type == KERNEL_FAULT) && (fault == VM_FAULT_BADCONTEXT)) {
257 address = get_fault_address(regs);
258 is_write = fault_is_write(regs);
259 if (kfence_handle_page_fault(address, is_write, regs))
260 return;
261 }
262 /*
263 * Oops. The kernel tried to access some bad page. We'll have to
264 * terminate things with extreme prejudice.
265 */
266 if (fault_type == KERNEL_FAULT)
267 printk(KERN_ALERT "Unable to handle kernel pointer dereference"
268 " in virtual kernel address space\n");
269 else
270 printk(KERN_ALERT "Unable to handle kernel paging request"
271 " in virtual user address space\n");
272 dump_fault_info(regs);
273 die(regs, "Oops");
274 }
275
do_low_address(struct pt_regs * regs)276 static noinline void do_low_address(struct pt_regs *regs)
277 {
278 /* Low-address protection hit in kernel mode means
279 NULL pointer write access in kernel mode. */
280 if (regs->psw.mask & PSW_MASK_PSTATE) {
281 /* Low-address protection hit in user mode 'cannot happen'. */
282 die (regs, "Low-address protection");
283 }
284
285 do_no_context(regs, VM_FAULT_BADACCESS);
286 }
287
do_sigbus(struct pt_regs * regs)288 static noinline void do_sigbus(struct pt_regs *regs)
289 {
290 /*
291 * Send a sigbus, regardless of whether we were in kernel
292 * or user mode.
293 */
294 force_sig_fault(SIGBUS, BUS_ADRERR,
295 (void __user *)(regs->int_parm_long & __FAIL_ADDR_MASK));
296 }
297
do_fault_error(struct pt_regs * regs,vm_fault_t fault)298 static noinline void do_fault_error(struct pt_regs *regs, vm_fault_t fault)
299 {
300 int si_code;
301
302 switch (fault) {
303 case VM_FAULT_BADACCESS:
304 case VM_FAULT_BADMAP:
305 /* Bad memory access. Check if it is kernel or user space. */
306 if (user_mode(regs)) {
307 /* User mode accesses just cause a SIGSEGV */
308 si_code = (fault == VM_FAULT_BADMAP) ?
309 SEGV_MAPERR : SEGV_ACCERR;
310 do_sigsegv(regs, si_code);
311 break;
312 }
313 fallthrough;
314 case VM_FAULT_BADCONTEXT:
315 case VM_FAULT_PFAULT:
316 do_no_context(regs, fault);
317 break;
318 case VM_FAULT_SIGNAL:
319 if (!user_mode(regs))
320 do_no_context(regs, fault);
321 break;
322 default: /* fault & VM_FAULT_ERROR */
323 if (fault & VM_FAULT_OOM) {
324 if (!user_mode(regs))
325 do_no_context(regs, fault);
326 else
327 pagefault_out_of_memory();
328 } else if (fault & VM_FAULT_SIGSEGV) {
329 /* Kernel mode? Handle exceptions or die */
330 if (!user_mode(regs))
331 do_no_context(regs, fault);
332 else
333 do_sigsegv(regs, SEGV_MAPERR);
334 } else if (fault & VM_FAULT_SIGBUS) {
335 /* Kernel mode? Handle exceptions or die */
336 if (!user_mode(regs))
337 do_no_context(regs, fault);
338 else
339 do_sigbus(regs);
340 } else
341 BUG();
342 break;
343 }
344 }
345
346 /*
347 * This routine handles page faults. It determines the address,
348 * and the problem, and then passes it off to one of the appropriate
349 * routines.
350 *
351 * interruption code (int_code):
352 * 04 Protection -> Write-Protection (suppression)
353 * 10 Segment translation -> Not present (nullification)
354 * 11 Page translation -> Not present (nullification)
355 * 3b Region third trans. -> Not present (nullification)
356 */
do_exception(struct pt_regs * regs,int access)357 static inline vm_fault_t do_exception(struct pt_regs *regs, int access)
358 {
359 struct gmap *gmap;
360 struct task_struct *tsk;
361 struct mm_struct *mm;
362 struct vm_area_struct *vma;
363 enum fault_type type;
364 unsigned long address;
365 unsigned int flags;
366 vm_fault_t fault;
367 bool is_write;
368
369 tsk = current;
370 /*
371 * The instruction that caused the program check has
372 * been nullified. Don't signal single step via SIGTRAP.
373 */
374 clear_thread_flag(TIF_PER_TRAP);
375
376 if (kprobe_page_fault(regs, 14))
377 return 0;
378
379 mm = tsk->mm;
380 address = get_fault_address(regs);
381 is_write = fault_is_write(regs);
382
383 /*
384 * Verify that the fault happened in user space, that
385 * we are not in an interrupt and that there is a
386 * user context.
387 */
388 fault = VM_FAULT_BADCONTEXT;
389 type = get_fault_type(regs);
390 switch (type) {
391 case KERNEL_FAULT:
392 goto out;
393 case USER_FAULT:
394 case GMAP_FAULT:
395 if (faulthandler_disabled() || !mm)
396 goto out;
397 break;
398 }
399
400 perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
401 flags = FAULT_FLAG_DEFAULT;
402 if (user_mode(regs))
403 flags |= FAULT_FLAG_USER;
404 if (is_write)
405 access = VM_WRITE;
406 if (access == VM_WRITE)
407 flags |= FAULT_FLAG_WRITE;
408 if (!(flags & FAULT_FLAG_USER))
409 goto lock_mmap;
410 vma = lock_vma_under_rcu(mm, address);
411 if (!vma)
412 goto lock_mmap;
413 if (!(vma->vm_flags & access)) {
414 vma_end_read(vma);
415 goto lock_mmap;
416 }
417 fault = handle_mm_fault(vma, address, flags | FAULT_FLAG_VMA_LOCK, regs);
418 if (!(fault & (VM_FAULT_RETRY | VM_FAULT_COMPLETED)))
419 vma_end_read(vma);
420 if (!(fault & VM_FAULT_RETRY)) {
421 count_vm_vma_lock_event(VMA_LOCK_SUCCESS);
422 if (likely(!(fault & VM_FAULT_ERROR)))
423 fault = 0;
424 goto out;
425 }
426 count_vm_vma_lock_event(VMA_LOCK_RETRY);
427 /* Quick path to respond to signals */
428 if (fault_signal_pending(fault, regs)) {
429 fault = VM_FAULT_SIGNAL;
430 goto out;
431 }
432 lock_mmap:
433 mmap_read_lock(mm);
434
435 gmap = NULL;
436 if (IS_ENABLED(CONFIG_PGSTE) && type == GMAP_FAULT) {
437 gmap = (struct gmap *) S390_lowcore.gmap;
438 current->thread.gmap_addr = address;
439 current->thread.gmap_write_flag = !!(flags & FAULT_FLAG_WRITE);
440 current->thread.gmap_int_code = regs->int_code & 0xffff;
441 address = __gmap_translate(gmap, address);
442 if (address == -EFAULT) {
443 fault = VM_FAULT_BADMAP;
444 goto out_up;
445 }
446 if (gmap->pfault_enabled)
447 flags |= FAULT_FLAG_RETRY_NOWAIT;
448 }
449
450 retry:
451 fault = VM_FAULT_BADMAP;
452 vma = find_vma(mm, address);
453 if (!vma)
454 goto out_up;
455
456 if (unlikely(vma->vm_start > address)) {
457 if (!(vma->vm_flags & VM_GROWSDOWN))
458 goto out_up;
459 vma = expand_stack(mm, address);
460 if (!vma)
461 goto out;
462 }
463
464 /*
465 * Ok, we have a good vm_area for this memory access, so
466 * we can handle it..
467 */
468 fault = VM_FAULT_BADACCESS;
469 if (unlikely(!(vma->vm_flags & access)))
470 goto out_up;
471
472 /*
473 * If for any reason at all we couldn't handle the fault,
474 * make sure we exit gracefully rather than endlessly redo
475 * the fault.
476 */
477 fault = handle_mm_fault(vma, address, flags, regs);
478 if (fault_signal_pending(fault, regs)) {
479 fault = VM_FAULT_SIGNAL;
480 if (flags & FAULT_FLAG_RETRY_NOWAIT)
481 goto out_up;
482 goto out;
483 }
484
485 /* The fault is fully completed (including releasing mmap lock) */
486 if (fault & VM_FAULT_COMPLETED) {
487 if (gmap) {
488 mmap_read_lock(mm);
489 goto out_gmap;
490 }
491 fault = 0;
492 goto out;
493 }
494
495 if (unlikely(fault & VM_FAULT_ERROR))
496 goto out_up;
497
498 if (fault & VM_FAULT_RETRY) {
499 if (IS_ENABLED(CONFIG_PGSTE) && gmap &&
500 (flags & FAULT_FLAG_RETRY_NOWAIT)) {
501 /*
502 * FAULT_FLAG_RETRY_NOWAIT has been set, mmap_lock has
503 * not been released
504 */
505 current->thread.gmap_pfault = 1;
506 fault = VM_FAULT_PFAULT;
507 goto out_up;
508 }
509 flags &= ~FAULT_FLAG_RETRY_NOWAIT;
510 flags |= FAULT_FLAG_TRIED;
511 mmap_read_lock(mm);
512 goto retry;
513 }
514 out_gmap:
515 if (IS_ENABLED(CONFIG_PGSTE) && gmap) {
516 address = __gmap_link(gmap, current->thread.gmap_addr,
517 address);
518 if (address == -EFAULT) {
519 fault = VM_FAULT_BADMAP;
520 goto out_up;
521 }
522 if (address == -ENOMEM) {
523 fault = VM_FAULT_OOM;
524 goto out_up;
525 }
526 }
527 fault = 0;
528 out_up:
529 mmap_read_unlock(mm);
530 out:
531 return fault;
532 }
533
do_protection_exception(struct pt_regs * regs)534 void do_protection_exception(struct pt_regs *regs)
535 {
536 unsigned long trans_exc_code;
537 int access;
538 vm_fault_t fault;
539
540 trans_exc_code = regs->int_parm_long;
541 /*
542 * Protection exceptions are suppressing, decrement psw address.
543 * The exception to this rule are aborted transactions, for these
544 * the PSW already points to the correct location.
545 */
546 if (!(regs->int_code & 0x200))
547 regs->psw.addr = __rewind_psw(regs->psw, regs->int_code >> 16);
548 /*
549 * Check for low-address protection. This needs to be treated
550 * as a special case because the translation exception code
551 * field is not guaranteed to contain valid data in this case.
552 */
553 if (unlikely(!(trans_exc_code & 4))) {
554 do_low_address(regs);
555 return;
556 }
557 if (unlikely(MACHINE_HAS_NX && (trans_exc_code & 0x80))) {
558 regs->int_parm_long = (trans_exc_code & ~PAGE_MASK) |
559 (regs->psw.addr & PAGE_MASK);
560 access = VM_EXEC;
561 fault = VM_FAULT_BADACCESS;
562 } else {
563 access = VM_WRITE;
564 fault = do_exception(regs, access);
565 }
566 if (unlikely(fault))
567 do_fault_error(regs, fault);
568 }
569 NOKPROBE_SYMBOL(do_protection_exception);
570
do_dat_exception(struct pt_regs * regs)571 void do_dat_exception(struct pt_regs *regs)
572 {
573 int access;
574 vm_fault_t fault;
575
576 access = VM_ACCESS_FLAGS;
577 fault = do_exception(regs, access);
578 if (unlikely(fault))
579 do_fault_error(regs, fault);
580 }
581 NOKPROBE_SYMBOL(do_dat_exception);
582
583 #if IS_ENABLED(CONFIG_PGSTE)
584
do_secure_storage_access(struct pt_regs * regs)585 void do_secure_storage_access(struct pt_regs *regs)
586 {
587 unsigned long addr = regs->int_parm_long & __FAIL_ADDR_MASK;
588 struct vm_area_struct *vma;
589 struct mm_struct *mm;
590 struct page *page;
591 struct gmap *gmap;
592 int rc;
593
594 /*
595 * bit 61 tells us if the address is valid, if it's not we
596 * have a major problem and should stop the kernel or send a
597 * SIGSEGV to the process. Unfortunately bit 61 is not
598 * reliable without the misc UV feature so we need to check
599 * for that as well.
600 */
601 if (uv_has_feature(BIT_UV_FEAT_MISC) &&
602 !test_bit_inv(61, ®s->int_parm_long)) {
603 /*
604 * When this happens, userspace did something that it
605 * was not supposed to do, e.g. branching into secure
606 * memory. Trigger a segmentation fault.
607 */
608 if (user_mode(regs)) {
609 send_sig(SIGSEGV, current, 0);
610 return;
611 }
612
613 /*
614 * The kernel should never run into this case and we
615 * have no way out of this situation.
616 */
617 panic("Unexpected PGM 0x3d with TEID bit 61=0");
618 }
619
620 switch (get_fault_type(regs)) {
621 case GMAP_FAULT:
622 mm = current->mm;
623 gmap = (struct gmap *)S390_lowcore.gmap;
624 mmap_read_lock(mm);
625 addr = __gmap_translate(gmap, addr);
626 mmap_read_unlock(mm);
627 if (IS_ERR_VALUE(addr)) {
628 do_fault_error(regs, VM_FAULT_BADMAP);
629 break;
630 }
631 fallthrough;
632 case USER_FAULT:
633 mm = current->mm;
634 mmap_read_lock(mm);
635 vma = find_vma(mm, addr);
636 if (!vma) {
637 mmap_read_unlock(mm);
638 do_fault_error(regs, VM_FAULT_BADMAP);
639 break;
640 }
641 page = follow_page(vma, addr, FOLL_WRITE | FOLL_GET);
642 if (IS_ERR_OR_NULL(page)) {
643 mmap_read_unlock(mm);
644 break;
645 }
646 if (arch_make_page_accessible(page))
647 send_sig(SIGSEGV, current, 0);
648 put_page(page);
649 mmap_read_unlock(mm);
650 break;
651 case KERNEL_FAULT:
652 page = phys_to_page(addr);
653 if (unlikely(!try_get_page(page)))
654 break;
655 rc = arch_make_page_accessible(page);
656 put_page(page);
657 if (rc)
658 BUG();
659 break;
660 default:
661 do_fault_error(regs, VM_FAULT_BADMAP);
662 WARN_ON_ONCE(1);
663 }
664 }
665 NOKPROBE_SYMBOL(do_secure_storage_access);
666
do_non_secure_storage_access(struct pt_regs * regs)667 void do_non_secure_storage_access(struct pt_regs *regs)
668 {
669 unsigned long gaddr = regs->int_parm_long & __FAIL_ADDR_MASK;
670 struct gmap *gmap = (struct gmap *)S390_lowcore.gmap;
671
672 if (get_fault_type(regs) != GMAP_FAULT) {
673 do_fault_error(regs, VM_FAULT_BADMAP);
674 WARN_ON_ONCE(1);
675 return;
676 }
677
678 if (gmap_convert_to_secure(gmap, gaddr) == -EINVAL)
679 send_sig(SIGSEGV, current, 0);
680 }
681 NOKPROBE_SYMBOL(do_non_secure_storage_access);
682
do_secure_storage_violation(struct pt_regs * regs)683 void do_secure_storage_violation(struct pt_regs *regs)
684 {
685 unsigned long gaddr = regs->int_parm_long & __FAIL_ADDR_MASK;
686 struct gmap *gmap = (struct gmap *)S390_lowcore.gmap;
687
688 /*
689 * If the VM has been rebooted, its address space might still contain
690 * secure pages from the previous boot.
691 * Clear the page so it can be reused.
692 */
693 if (!gmap_destroy_page(gmap, gaddr))
694 return;
695 /*
696 * Either KVM messed up the secure guest mapping or the same
697 * page is mapped into multiple secure guests.
698 *
699 * This exception is only triggered when a guest 2 is running
700 * and can therefore never occur in kernel context.
701 */
702 printk_ratelimited(KERN_WARNING
703 "Secure storage violation in task: %s, pid %d\n",
704 current->comm, current->pid);
705 send_sig(SIGSEGV, current, 0);
706 }
707
708 #endif /* CONFIG_PGSTE */
709