FreeBSD/Linux Kernel Cross Reference
sys/arm/arm/trap.c
1 /* $NetBSD: fault.c,v 1.45 2003/11/20 14:44:36 scw Exp $ */
2
3 /*-
4 * Copyright 2004 Olivier Houchard
5 * Copyright 2003 Wasabi Systems, Inc.
6 * All rights reserved.
7 *
8 * Written by Steve C. Woodford for Wasabi Systems, Inc.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. All advertising materials mentioning features or use of this software
19 * must display the following acknowledgement:
20 * This product includes software developed for the NetBSD Project by
21 * Wasabi Systems, Inc.
22 * 4. The name of Wasabi Systems, Inc. may not be used to endorse
23 * or promote products derived from this software without specific prior
24 * written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL WASABI SYSTEMS, INC
30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36 * POSSIBILITY OF SUCH DAMAGE.
37 */
38 /*-
39 * Copyright (c) 1994-1997 Mark Brinicombe.
40 * Copyright (c) 1994 Brini.
41 * All rights reserved.
42 *
43 * This code is derived from software written for Brini by Mark Brinicombe
44 *
45 * Redistribution and use in source and binary forms, with or without
46 * modification, are permitted provided that the following conditions
47 * are met:
48 * 1. Redistributions of source code must retain the above copyright
49 * notice, this list of conditions and the following disclaimer.
50 * 2. Redistributions in binary form must reproduce the above copyright
51 * notice, this list of conditions and the following disclaimer in the
52 * documentation and/or other materials provided with the distribution.
53 * 3. All advertising materials mentioning features or use of this software
54 * must display the following acknowledgement:
55 * This product includes software developed by Brini.
56 * 4. The name of the company nor the name of the author may be used to
57 * endorse or promote products derived from this software without specific
58 * prior written permission.
59 *
60 * THIS SOFTWARE IS PROVIDED BY BRINI ``AS IS'' AND ANY EXPRESS OR IMPLIED
61 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
62 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
63 * IN NO EVENT SHALL BRINI OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
64 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
65 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
66 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
67 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
68 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
69 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
70 * SUCH DAMAGE.
71 *
72 * RiscBSD kernel project
73 *
74 * fault.c
75 *
76 * Fault handlers
77 *
78 * Created : 28/11/94
79 */
80
81
82 #include <sys/cdefs.h>
83 __FBSDID("$FreeBSD: releng/10.2/sys/arm/arm/trap.c 278656 2015-02-13 02:02:12Z ian $");
84
85 #include <sys/param.h>
86 #include <sys/systm.h>
87 #include <sys/proc.h>
88 #include <sys/lock.h>
89 #include <sys/mutex.h>
90 #include <sys/signalvar.h>
91
92 #include <vm/vm.h>
93 #include <vm/pmap.h>
94 #include <vm/vm_kern.h>
95 #include <vm/vm_map.h>
96 #include <vm/vm_extern.h>
97
98 #include <machine/cpu.h>
99 #include <machine/frame.h>
100 #include <machine/machdep.h>
101 #include <machine/pcb.h>
102 #include <machine/vmparam.h>
103
104 #ifdef KDB
105 #include <sys/kdb.h>
106 #endif
107
108 extern char fusubailout[];
109
110 #ifdef DEBUG
111 int last_fault_code; /* For the benefit of pmap_fault_fixup() */
112 #endif
113
114 struct ksig {
115 int signb;
116 u_long code;
117 };
118 struct data_abort {
119 int (*func)(struct trapframe *, u_int, u_int, struct thread *,
120 struct ksig *);
121 const char *desc;
122 };
123
124 static int dab_fatal(struct trapframe *, u_int, u_int, struct thread *,
125 struct ksig *);
126 static int dab_align(struct trapframe *, u_int, u_int, struct thread *,
127 struct ksig *);
128 static int dab_buserr(struct trapframe *, u_int, u_int, struct thread *,
129 struct ksig *);
130 static void prefetch_abort_handler(struct trapframe *);
131
132 static const struct data_abort data_aborts[] = {
133 {dab_fatal, "Vector Exception"},
134 {dab_align, "Alignment Fault 1"},
135 {dab_fatal, "Terminal Exception"},
136 {dab_align, "Alignment Fault 3"},
137 {dab_buserr, "External Linefetch Abort (S)"},
138 {NULL, "Translation Fault (S)"},
139 #if (ARM_MMU_V6 + ARM_MMU_V7) != 0
140 {NULL, "Translation Flag Fault"},
141 #else
142 {dab_buserr, "External Linefetch Abort (P)"},
143 #endif
144 {NULL, "Translation Fault (P)"},
145 {dab_buserr, "External Non-Linefetch Abort (S)"},
146 {NULL, "Domain Fault (S)"},
147 {dab_buserr, "External Non-Linefetch Abort (P)"},
148 {NULL, "Domain Fault (P)"},
149 {dab_buserr, "External Translation Abort (L1)"},
150 {NULL, "Permission Fault (S)"},
151 {dab_buserr, "External Translation Abort (L2)"},
152 {NULL, "Permission Fault (P)"}
153 };
154
155 /* Determine if a fault came from user mode */
156 #define TRAP_USERMODE(tf) ((tf->tf_spsr & PSR_MODE) == PSR_USR32_MODE)
157
158 /* Determine if 'x' is a permission fault */
159 #define IS_PERMISSION_FAULT(x) \
160 (((1 << ((x) & FAULT_TYPE_MASK)) & \
161 ((1 << FAULT_PERM_P) | (1 << FAULT_PERM_S))) != 0)
162
163 static __inline void
164 call_trapsignal(struct thread *td, int sig, u_long code)
165 {
166 ksiginfo_t ksi;
167
168 ksiginfo_init_trap(&ksi);
169 ksi.ksi_signo = sig;
170 ksi.ksi_code = (int)code;
171 trapsignal(td, &ksi);
172 }
173
174 void
175 abort_handler(struct trapframe *tf, int type)
176 {
177 struct vm_map *map;
178 struct pcb *pcb;
179 struct thread *td;
180 u_int user, far, fsr;
181 vm_prot_t ftype;
182 void *onfault;
183 vm_offset_t va;
184 int error = 0;
185 struct ksig ksig;
186 struct proc *p;
187
188 if (type == 1)
189 return (prefetch_abort_handler(tf));
190
191 /* Grab FAR/FSR before enabling interrupts */
192 far = cpu_faultaddress();
193 fsr = cpu_faultstatus();
194 #if 0
195 printf("data abort: fault address=%p (from pc=%p lr=%p)\n",
196 (void*)far, (void*)tf->tf_pc, (void*)tf->tf_svc_lr);
197 #endif
198
199 /* Update vmmeter statistics */
200 #if 0
201 vmexp.traps++;
202 #endif
203
204 td = curthread;
205 p = td->td_proc;
206
207 PCPU_INC(cnt.v_trap);
208 /* Data abort came from user mode? */
209 user = TRAP_USERMODE(tf);
210
211 if (user) {
212 td->td_pticks = 0;
213 td->td_frame = tf;
214 if (td->td_ucred != td->td_proc->p_ucred)
215 cred_update_thread(td);
216
217 }
218 /* Grab the current pcb */
219 pcb = td->td_pcb;
220 /* Re-enable interrupts if they were enabled previously */
221 if (td->td_md.md_spinlock_count == 0) {
222 if (__predict_true(tf->tf_spsr & PSR_I) == 0)
223 enable_interrupts(PSR_I);
224 if (__predict_true(tf->tf_spsr & PSR_F) == 0)
225 enable_interrupts(PSR_F);
226 }
227
228
229 /* Invoke the appropriate handler, if necessary */
230 if (__predict_false(data_aborts[fsr & FAULT_TYPE_MASK].func != NULL)) {
231 if ((data_aborts[fsr & FAULT_TYPE_MASK].func)(tf, fsr, far,
232 td, &ksig)) {
233 goto do_trapsignal;
234 }
235 goto out;
236 }
237
238 /*
239 * At this point, we're dealing with one of the following data aborts:
240 *
241 * FAULT_TRANS_S - Translation -- Section
242 * FAULT_TRANS_P - Translation -- Page
243 * FAULT_DOMAIN_S - Domain -- Section
244 * FAULT_DOMAIN_P - Domain -- Page
245 * FAULT_PERM_S - Permission -- Section
246 * FAULT_PERM_P - Permission -- Page
247 *
248 * These are the main virtual memory-related faults signalled by
249 * the MMU.
250 */
251
252 /* fusubailout is used by [fs]uswintr to avoid page faulting */
253 if (__predict_false(pcb->pcb_onfault == fusubailout)) {
254 tf->tf_r0 = EFAULT;
255 tf->tf_pc = (register_t)(intptr_t) pcb->pcb_onfault;
256 return;
257 }
258
259 /*
260 * Make sure the Program Counter is sane. We could fall foul of
261 * someone executing Thumb code, in which case the PC might not
262 * be word-aligned. This would cause a kernel alignment fault
263 * further down if we have to decode the current instruction.
264 * XXX: It would be nice to be able to support Thumb at some point.
265 */
266 if (__predict_false((tf->tf_pc & 3) != 0)) {
267 if (user) {
268 /*
269 * Give the user an illegal instruction signal.
270 */
271 /* Deliver a SIGILL to the process */
272 ksig.signb = SIGILL;
273 ksig.code = 0;
274 goto do_trapsignal;
275 }
276
277 /*
278 * The kernel never executes Thumb code.
279 */
280 printf("\ndata_abort_fault: Misaligned Kernel-mode "
281 "Program Counter\n");
282 dab_fatal(tf, fsr, far, td, &ksig);
283 }
284
285 va = trunc_page((vm_offset_t)far);
286
287 /*
288 * It is only a kernel address space fault iff:
289 * 1. user == 0 and
290 * 2. pcb_onfault not set or
291 * 3. pcb_onfault set and not LDRT/LDRBT/STRT/STRBT instruction.
292 */
293 if (user == 0 && (va >= VM_MIN_KERNEL_ADDRESS ||
294 (va < VM_MIN_ADDRESS && vector_page == ARM_VECTORS_LOW)) &&
295 __predict_true((pcb->pcb_onfault == NULL ||
296 (ReadWord(tf->tf_pc) & 0x05200000) != 0x04200000))) {
297 map = kernel_map;
298
299 /* Was the fault due to the FPE/IPKDB ? */
300 if (__predict_false((tf->tf_spsr & PSR_MODE)==PSR_UND32_MODE)) {
301
302 /*
303 * Force exit via userret()
304 * This is necessary as the FPE is an extension to
305 * userland that actually runs in a priveledged mode
306 * but uses USR mode permissions for its accesses.
307 */
308 user = 1;
309 ksig.signb = SIGSEGV;
310 ksig.code = 0;
311 goto do_trapsignal;
312 }
313 } else {
314 map = &td->td_proc->p_vmspace->vm_map;
315 }
316
317 /*
318 * We need to know whether the page should be mapped as R or R/W. On
319 * armv6 and later the fault status register indicates whether the
320 * access was a read or write. Prior to armv6, we know that a
321 * permission fault can only be the result of a write to a read-only
322 * location, so we can deal with those quickly. Otherwise we need to
323 * disassemble the faulting instruction to determine if it was a write.
324 */
325 #if ARM_ARCH_6 || ARM_ARCH_7A
326 ftype = (fsr & FAULT_WNR) ? VM_PROT_READ | VM_PROT_WRITE : VM_PROT_READ;
327 #else
328 if (IS_PERMISSION_FAULT(fsr))
329 ftype = VM_PROT_WRITE;
330 else {
331 u_int insn = ReadWord(tf->tf_pc);
332
333 if (((insn & 0x0c100000) == 0x04000000) || /* STR/STRB */
334 ((insn & 0x0e1000b0) == 0x000000b0) || /* STRH/STRD */
335 ((insn & 0x0a100000) == 0x08000000)) { /* STM/CDT */
336 ftype = VM_PROT_WRITE;
337 } else {
338 if ((insn & 0x0fb00ff0) == 0x01000090) /* SWP */
339 ftype = VM_PROT_READ | VM_PROT_WRITE;
340 else
341 ftype = VM_PROT_READ;
342 }
343 }
344 #endif
345
346 /*
347 * See if the fault is as a result of ref/mod emulation,
348 * or domain mismatch.
349 */
350 #ifdef DEBUG
351 last_fault_code = fsr;
352 #endif
353 if (pmap_fault_fixup(vmspace_pmap(td->td_proc->p_vmspace), va, ftype,
354 user)) {
355 goto out;
356 }
357
358 onfault = pcb->pcb_onfault;
359 pcb->pcb_onfault = NULL;
360 if (map != kernel_map) {
361 PROC_LOCK(p);
362 p->p_lock++;
363 PROC_UNLOCK(p);
364 }
365 error = vm_fault(map, va, ftype, VM_FAULT_NORMAL);
366 pcb->pcb_onfault = onfault;
367
368 if (map != kernel_map) {
369 PROC_LOCK(p);
370 p->p_lock--;
371 PROC_UNLOCK(p);
372 }
373 if (__predict_true(error == 0))
374 goto out;
375 if (user == 0) {
376 if (pcb->pcb_onfault) {
377 tf->tf_r0 = error;
378 tf->tf_pc = (register_t)(intptr_t) pcb->pcb_onfault;
379 return;
380 }
381
382 printf("\nvm_fault(%p, %x, %x, 0) -> %x\n", map, va, ftype,
383 error);
384 dab_fatal(tf, fsr, far, td, &ksig);
385 }
386
387
388 if (error == ENOMEM) {
389 printf("VM: pid %d (%s), uid %d killed: "
390 "out of swap\n", td->td_proc->p_pid, td->td_name,
391 (td->td_proc->p_ucred) ?
392 td->td_proc->p_ucred->cr_uid : -1);
393 ksig.signb = SIGKILL;
394 } else {
395 ksig.signb = SIGSEGV;
396 }
397 ksig.code = 0;
398 do_trapsignal:
399 call_trapsignal(td, ksig.signb, ksig.code);
400 out:
401 /* If returning to user mode, make sure to invoke userret() */
402 if (user)
403 userret(td, tf);
404 }
405
406 /*
407 * dab_fatal() handles the following data aborts:
408 *
409 * FAULT_WRTBUF_0 - Vector Exception
410 * FAULT_WRTBUF_1 - Terminal Exception
411 *
412 * We should never see these on a properly functioning system.
413 *
414 * This function is also called by the other handlers if they
415 * detect a fatal problem.
416 *
417 * Note: If 'l' is NULL, we assume we're dealing with a prefetch abort.
418 */
419 static int
420 dab_fatal(struct trapframe *tf, u_int fsr, u_int far, struct thread *td,
421 struct ksig *ksig)
422 {
423 const char *mode;
424
425 mode = TRAP_USERMODE(tf) ? "user" : "kernel";
426
427 disable_interrupts(PSR_I|PSR_F);
428 if (td != NULL) {
429 printf("Fatal %s mode data abort: '%s'\n", mode,
430 data_aborts[fsr & FAULT_TYPE_MASK].desc);
431 printf("trapframe: %p\nFSR=%08x, FAR=", tf, fsr);
432 if ((fsr & FAULT_IMPRECISE) == 0)
433 printf("%08x, ", far);
434 else
435 printf("Invalid, ");
436 printf("spsr=%08x\n", tf->tf_spsr);
437 } else {
438 printf("Fatal %s mode prefetch abort at 0x%08x\n",
439 mode, tf->tf_pc);
440 printf("trapframe: %p, spsr=%08x\n", tf, tf->tf_spsr);
441 }
442
443 printf("r0 =%08x, r1 =%08x, r2 =%08x, r3 =%08x\n",
444 tf->tf_r0, tf->tf_r1, tf->tf_r2, tf->tf_r3);
445 printf("r4 =%08x, r5 =%08x, r6 =%08x, r7 =%08x\n",
446 tf->tf_r4, tf->tf_r5, tf->tf_r6, tf->tf_r7);
447 printf("r8 =%08x, r9 =%08x, r10=%08x, r11=%08x\n",
448 tf->tf_r8, tf->tf_r9, tf->tf_r10, tf->tf_r11);
449 printf("r12=%08x, ", tf->tf_r12);
450
451 if (TRAP_USERMODE(tf))
452 printf("usp=%08x, ulr=%08x",
453 tf->tf_usr_sp, tf->tf_usr_lr);
454 else
455 printf("ssp=%08x, slr=%08x",
456 tf->tf_svc_sp, tf->tf_svc_lr);
457 printf(", pc =%08x\n\n", tf->tf_pc);
458
459 #ifdef KDB
460 if (debugger_on_panic || kdb_active)
461 if (kdb_trap(fsr, 0, tf))
462 return (0);
463 #endif
464 panic("Fatal abort");
465 /*NOTREACHED*/
466 }
467
468 /*
469 * dab_align() handles the following data aborts:
470 *
471 * FAULT_ALIGN_0 - Alignment fault
472 * FAULT_ALIGN_1 - Alignment fault
473 *
474 * These faults are fatal if they happen in kernel mode. Otherwise, we
475 * deliver a bus error to the process.
476 */
477 static int
478 dab_align(struct trapframe *tf, u_int fsr, u_int far, struct thread *td,
479 struct ksig *ksig)
480 {
481
482 /* Alignment faults are always fatal if they occur in kernel mode */
483 if (!TRAP_USERMODE(tf)) {
484 if (!td || !td->td_pcb->pcb_onfault)
485 dab_fatal(tf, fsr, far, td, ksig);
486 tf->tf_r0 = EFAULT;
487 tf->tf_pc = (int)td->td_pcb->pcb_onfault;
488 return (0);
489 }
490
491 /* pcb_onfault *must* be NULL at this point */
492
493 /* Deliver a bus error signal to the process */
494 ksig->code = 0;
495 ksig->signb = SIGBUS;
496 td->td_frame = tf;
497
498 return (1);
499 }
500
501 /*
502 * dab_buserr() handles the following data aborts:
503 *
504 * FAULT_BUSERR_0 - External Abort on Linefetch -- Section
505 * FAULT_BUSERR_1 - External Abort on Linefetch -- Page
506 * FAULT_BUSERR_2 - External Abort on Non-linefetch -- Section
507 * FAULT_BUSERR_3 - External Abort on Non-linefetch -- Page
508 * FAULT_BUSTRNL1 - External abort on Translation -- Level 1
509 * FAULT_BUSTRNL2 - External abort on Translation -- Level 2
510 *
511 * If pcb_onfault is set, flag the fault and return to the handler.
512 * If the fault occurred in user mode, give the process a SIGBUS.
513 *
514 * Note: On XScale, FAULT_BUSERR_0, FAULT_BUSERR_1, and FAULT_BUSERR_2
515 * can be flagged as imprecise in the FSR. This causes a real headache
516 * since some of the machine state is lost. In this case, tf->tf_pc
517 * may not actually point to the offending instruction. In fact, if
518 * we've taken a double abort fault, it generally points somewhere near
519 * the top of "data_abort_entry" in exception.S.
520 *
521 * In all other cases, these data aborts are considered fatal.
522 */
523 static int
524 dab_buserr(struct trapframe *tf, u_int fsr, u_int far, struct thread *td,
525 struct ksig *ksig)
526 {
527 struct pcb *pcb = td->td_pcb;
528
529 #ifdef __XSCALE__
530 if ((fsr & FAULT_IMPRECISE) != 0 &&
531 (tf->tf_spsr & PSR_MODE) == PSR_ABT32_MODE) {
532 /*
533 * Oops, an imprecise, double abort fault. We've lost the
534 * r14_abt/spsr_abt values corresponding to the original
535 * abort, and the spsr saved in the trapframe indicates
536 * ABT mode.
537 */
538 tf->tf_spsr &= ~PSR_MODE;
539
540 /*
541 * We use a simple heuristic to determine if the double abort
542 * happened as a result of a kernel or user mode access.
543 * If the current trapframe is at the top of the kernel stack,
544 * the fault _must_ have come from user mode.
545 */
546 if (tf != ((struct trapframe *)pcb->pcb_regs.sf_sp) - 1) {
547 /*
548 * Kernel mode. We're either about to die a
549 * spectacular death, or pcb_onfault will come
550 * to our rescue. Either way, the current value
551 * of tf->tf_pc is irrelevant.
552 */
553 tf->tf_spsr |= PSR_SVC32_MODE;
554 if (pcb->pcb_onfault == NULL)
555 printf("\nKernel mode double abort!\n");
556 } else {
557 /*
558 * User mode. We've lost the program counter at the
559 * time of the fault (not that it was accurate anyway;
560 * it's not called an imprecise fault for nothing).
561 * About all we can do is copy r14_usr to tf_pc and
562 * hope for the best. The process is about to get a
563 * SIGBUS, so it's probably history anyway.
564 */
565 tf->tf_spsr |= PSR_USR32_MODE;
566 tf->tf_pc = tf->tf_usr_lr;
567 }
568 }
569
570 /* FAR is invalid for imprecise exceptions */
571 if ((fsr & FAULT_IMPRECISE) != 0)
572 far = 0;
573 #endif /* __XSCALE__ */
574
575 if (pcb->pcb_onfault) {
576 tf->tf_r0 = EFAULT;
577 tf->tf_pc = (register_t)(intptr_t) pcb->pcb_onfault;
578 return (0);
579 }
580
581 /*
582 * At this point, if the fault happened in kernel mode, we're toast
583 */
584 if (!TRAP_USERMODE(tf))
585 dab_fatal(tf, fsr, far, td, ksig);
586
587 /* Deliver a bus error signal to the process */
588 ksig->signb = SIGBUS;
589 ksig->code = 0;
590 td->td_frame = tf;
591
592 return (1);
593 }
594
595 /*
596 * void prefetch_abort_handler(struct trapframe *tf)
597 *
598 * Abort handler called when instruction execution occurs at
599 * a non existent or restricted (access permissions) memory page.
600 * If the address is invalid and we were in SVC mode then panic as
601 * the kernel should never prefetch abort.
602 * If the address is invalid and the page is mapped then the user process
603 * does no have read permission so send it a signal.
604 * Otherwise fault the page in and try again.
605 */
606 static void
607 prefetch_abort_handler(struct trapframe *tf)
608 {
609 struct thread *td;
610 struct proc * p;
611 struct vm_map *map;
612 vm_offset_t fault_pc, va;
613 int error = 0;
614 struct ksig ksig;
615
616
617 #if 0
618 /* Update vmmeter statistics */
619 uvmexp.traps++;
620 #endif
621 #if 0
622 printf("prefetch abort handler: %p %p\n", (void*)tf->tf_pc,
623 (void*)tf->tf_usr_lr);
624 #endif
625
626 td = curthread;
627 p = td->td_proc;
628 PCPU_INC(cnt.v_trap);
629
630 if (TRAP_USERMODE(tf)) {
631 td->td_frame = tf;
632 if (td->td_ucred != td->td_proc->p_ucred)
633 cred_update_thread(td);
634 }
635 fault_pc = tf->tf_pc;
636 if (td->td_md.md_spinlock_count == 0) {
637 if (__predict_true(tf->tf_spsr & PSR_I) == 0)
638 enable_interrupts(PSR_I);
639 if (__predict_true(tf->tf_spsr & PSR_F) == 0)
640 enable_interrupts(PSR_F);
641 }
642
643 /* Prefetch aborts cannot happen in kernel mode */
644 if (__predict_false(!TRAP_USERMODE(tf)))
645 dab_fatal(tf, 0, tf->tf_pc, NULL, &ksig);
646 td->td_pticks = 0;
647
648
649 /* Ok validate the address, can only execute in USER space */
650 if (__predict_false(fault_pc >= VM_MAXUSER_ADDRESS ||
651 (fault_pc < VM_MIN_ADDRESS && vector_page == ARM_VECTORS_LOW))) {
652 ksig.signb = SIGSEGV;
653 ksig.code = 0;
654 goto do_trapsignal;
655 }
656
657 map = &td->td_proc->p_vmspace->vm_map;
658 va = trunc_page(fault_pc);
659
660 /*
661 * See if the pmap can handle this fault on its own...
662 */
663 #ifdef DEBUG
664 last_fault_code = -1;
665 #endif
666 if (pmap_fault_fixup(map->pmap, va, VM_PROT_READ, 1))
667 goto out;
668
669 if (map != kernel_map) {
670 PROC_LOCK(p);
671 p->p_lock++;
672 PROC_UNLOCK(p);
673 }
674
675 error = vm_fault(map, va, VM_PROT_READ | VM_PROT_EXECUTE,
676 VM_FAULT_NORMAL);
677 if (map != kernel_map) {
678 PROC_LOCK(p);
679 p->p_lock--;
680 PROC_UNLOCK(p);
681 }
682
683 if (__predict_true(error == 0))
684 goto out;
685
686 if (error == ENOMEM) {
687 printf("VM: pid %d (%s), uid %d killed: "
688 "out of swap\n", td->td_proc->p_pid, td->td_name,
689 (td->td_proc->p_ucred) ?
690 td->td_proc->p_ucred->cr_uid : -1);
691 ksig.signb = SIGKILL;
692 } else {
693 ksig.signb = SIGSEGV;
694 }
695 ksig.code = 0;
696
697 do_trapsignal:
698 call_trapsignal(td, ksig.signb, ksig.code);
699
700 out:
701 userret(td, tf);
702
703 }
704
705 extern int badaddr_read_1(const uint8_t *, uint8_t *);
706 extern int badaddr_read_2(const uint16_t *, uint16_t *);
707 extern int badaddr_read_4(const uint32_t *, uint32_t *);
708 /*
709 * Tentatively read an 8, 16, or 32-bit value from 'addr'.
710 * If the read succeeds, the value is written to 'rptr' and zero is returned.
711 * Else, return EFAULT.
712 */
713 int
714 badaddr_read(void *addr, size_t size, void *rptr)
715 {
716 union {
717 uint8_t v1;
718 uint16_t v2;
719 uint32_t v4;
720 } u;
721 int rv;
722
723 cpu_drain_writebuf();
724
725 /* Read from the test address. */
726 switch (size) {
727 case sizeof(uint8_t):
728 rv = badaddr_read_1(addr, &u.v1);
729 if (rv == 0 && rptr)
730 *(uint8_t *) rptr = u.v1;
731 break;
732
733 case sizeof(uint16_t):
734 rv = badaddr_read_2(addr, &u.v2);
735 if (rv == 0 && rptr)
736 *(uint16_t *) rptr = u.v2;
737 break;
738
739 case sizeof(uint32_t):
740 rv = badaddr_read_4(addr, &u.v4);
741 if (rv == 0 && rptr)
742 *(uint32_t *) rptr = u.v4;
743 break;
744
745 default:
746 panic("badaddr: invalid size (%lu)", (u_long) size);
747 }
748
749 /* Return EFAULT if the address was invalid, else zero */
750 return (rv);
Cache object: babcb75ea31d747cd40be04db9b0bd5d
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