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 "opt_ktrace.h"
83
84 #include <sys/cdefs.h>
85 __FBSDID("$FreeBSD$");
86
87 #include <sys/param.h>
88 #include <sys/systm.h>
89 #include <sys/proc.h>
90 #include <sys/kernel.h>
91 #include <sys/lock.h>
92 #include <sys/mutex.h>
93 #include <sys/syscall.h>
94 #include <sys/sysent.h>
95 #include <sys/signalvar.h>
96 #include <sys/ktr.h>
97 #ifdef KTRACE
98 #include <sys/uio.h>
99 #include <sys/ktrace.h>
100 #endif
101 #include <sys/ptrace.h>
102 #include <sys/pioctl.h>
103
104 #include <vm/vm.h>
105 #include <vm/pmap.h>
106 #include <vm/vm_kern.h>
107 #include <vm/vm_map.h>
108 #include <vm/vm_extern.h>
109
110 #include <machine/cpuconf.h>
111 #include <machine/vmparam.h>
112 #include <machine/frame.h>
113 #include <machine/cpu.h>
114 #include <machine/intr.h>
115 #include <machine/pcb.h>
116 #include <machine/proc.h>
117 #include <machine/swi.h>
118
119 #include <security/audit/audit.h>
120
121 #ifdef KDB
122 #include <sys/kdb.h>
123 #endif
124
125
126 void swi_handler(trapframe_t *);
127 void undefinedinstruction(trapframe_t *);
128
129 #include <machine/disassem.h>
130 #include <machine/machdep.h>
131
132 extern char fusubailout[];
133
134 #ifdef DEBUG
135 int last_fault_code; /* For the benefit of pmap_fault_fixup() */
136 #endif
137
138 #if defined(CPU_ARM7TDMI)
139 /* These CPUs may need data/prefetch abort fixups */
140 #define CPU_ABORT_FIXUP_REQUIRED
141 #endif
142
143 struct ksig {
144 int signb;
145 u_long code;
146 };
147 struct data_abort {
148 int (*func)(trapframe_t *, u_int, u_int, struct thread *, struct ksig *);
149 const char *desc;
150 };
151
152 static int dab_fatal(trapframe_t *, u_int, u_int, struct thread *, struct ksig *);
153 static int dab_align(trapframe_t *, u_int, u_int, struct thread *, struct ksig *);
154 static int dab_buserr(trapframe_t *, u_int, u_int, struct thread *, struct ksig *);
155
156 static const struct data_abort data_aborts[] = {
157 {dab_fatal, "Vector Exception"},
158 {dab_align, "Alignment Fault 1"},
159 {dab_fatal, "Terminal Exception"},
160 {dab_align, "Alignment Fault 3"},
161 {dab_buserr, "External Linefetch Abort (S)"},
162 {NULL, "Translation Fault (S)"},
163 {dab_buserr, "External Linefetch Abort (P)"},
164 {NULL, "Translation Fault (P)"},
165 {dab_buserr, "External Non-Linefetch Abort (S)"},
166 {NULL, "Domain Fault (S)"},
167 {dab_buserr, "External Non-Linefetch Abort (P)"},
168 {NULL, "Domain Fault (P)"},
169 {dab_buserr, "External Translation Abort (L1)"},
170 {NULL, "Permission Fault (S)"},
171 {dab_buserr, "External Translation Abort (L2)"},
172 {NULL, "Permission Fault (P)"}
173 };
174
175 /* Determine if a fault came from user mode */
176 #define TRAP_USERMODE(tf) ((tf->tf_spsr & PSR_MODE) == PSR_USR32_MODE)
177
178 /* Determine if 'x' is a permission fault */
179 #define IS_PERMISSION_FAULT(x) \
180 (((1 << ((x) & FAULT_TYPE_MASK)) & \
181 ((1 << FAULT_PERM_P) | (1 << FAULT_PERM_S))) != 0)
182
183 static __inline void
184 call_trapsignal(struct thread *td, int sig, u_long code)
185 {
186 ksiginfo_t ksi;
187
188 ksiginfo_init_trap(&ksi);
189 ksi.ksi_signo = sig;
190 ksi.ksi_code = (int)code;
191 trapsignal(td, &ksi);
192 }
193
194 static __inline int
195 data_abort_fixup(trapframe_t *tf, u_int fsr, u_int far, struct thread *td, struct ksig *ksig)
196 {
197 #ifdef CPU_ABORT_FIXUP_REQUIRED
198 int error;
199
200 /* Call the cpu specific data abort fixup routine */
201 error = cpu_dataabt_fixup(tf);
202 if (__predict_true(error != ABORT_FIXUP_FAILED))
203 return (error);
204
205 /*
206 * Oops, couldn't fix up the instruction
207 */
208 printf("data_abort_fixup: fixup for %s mode data abort failed.\n",
209 TRAP_USERMODE(tf) ? "user" : "kernel");
210 printf("pc = 0x%08x, opcode 0x%08x, insn = ", tf->tf_pc,
211 *((u_int *)tf->tf_pc));
212 disassemble(tf->tf_pc);
213
214 /* Die now if this happened in kernel mode */
215 if (!TRAP_USERMODE(tf))
216 dab_fatal(tf, fsr, far, td, NULL, ksig);
217
218 return (error);
219 #else
220 return (ABORT_FIXUP_OK);
221 #endif /* CPU_ABORT_FIXUP_REQUIRED */
222 }
223
224 void
225 data_abort_handler(trapframe_t *tf)
226 {
227 struct vm_map *map;
228 struct pcb *pcb;
229 struct thread *td;
230 u_int user, far, fsr;
231 vm_prot_t ftype;
232 void *onfault;
233 vm_offset_t va;
234 int error = 0;
235 struct ksig ksig;
236 struct proc *p;
237
238
239 /* Grab FAR/FSR before enabling interrupts */
240 far = cpu_faultaddress();
241 fsr = cpu_faultstatus();
242 #if 0
243 printf("data abort: %p (from %p %p)\n", (void*)far, (void*)tf->tf_pc,
244 (void*)tf->tf_svc_lr);
245 #endif
246
247 /* Update vmmeter statistics */
248 #if 0
249 vmexp.traps++;
250 #endif
251
252 td = curthread;
253 p = td->td_proc;
254
255 PCPU_INC(cnt.v_trap);
256 /* Data abort came from user mode? */
257 user = TRAP_USERMODE(tf);
258
259 if (user) {
260 td->td_pticks = 0;
261 td->td_frame = tf;
262 if (td->td_ucred != td->td_proc->p_ucred)
263 cred_update_thread(td);
264
265 }
266 /* Grab the current pcb */
267 pcb = td->td_pcb;
268 /* Re-enable interrupts if they were enabled previously */
269 if (td->td_md.md_spinlock_count == 0) {
270 if (__predict_true(tf->tf_spsr & I32_bit) == 0)
271 enable_interrupts(I32_bit);
272 if (__predict_true(tf->tf_spsr & F32_bit) == 0)
273 enable_interrupts(F32_bit);
274 }
275
276
277 /* Invoke the appropriate handler, if necessary */
278 if (__predict_false(data_aborts[fsr & FAULT_TYPE_MASK].func != NULL)) {
279 if ((data_aborts[fsr & FAULT_TYPE_MASK].func)(tf, fsr, far,
280 td, &ksig)) {
281 goto do_trapsignal;
282 }
283 goto out;
284 }
285
286 /*
287 * At this point, we're dealing with one of the following data aborts:
288 *
289 * FAULT_TRANS_S - Translation -- Section
290 * FAULT_TRANS_P - Translation -- Page
291 * FAULT_DOMAIN_S - Domain -- Section
292 * FAULT_DOMAIN_P - Domain -- Page
293 * FAULT_PERM_S - Permission -- Section
294 * FAULT_PERM_P - Permission -- Page
295 *
296 * These are the main virtual memory-related faults signalled by
297 * the MMU.
298 */
299
300 /* fusubailout is used by [fs]uswintr to avoid page faulting */
301 if (__predict_false(pcb->pcb_onfault == fusubailout)) {
302 tf->tf_r0 = EFAULT;
303 tf->tf_pc = (register_t)(intptr_t) pcb->pcb_onfault;
304 return;
305 }
306
307 /*
308 * Make sure the Program Counter is sane. We could fall foul of
309 * someone executing Thumb code, in which case the PC might not
310 * be word-aligned. This would cause a kernel alignment fault
311 * further down if we have to decode the current instruction.
312 * XXX: It would be nice to be able to support Thumb at some point.
313 */
314 if (__predict_false((tf->tf_pc & 3) != 0)) {
315 if (user) {
316 /*
317 * Give the user an illegal instruction signal.
318 */
319 /* Deliver a SIGILL to the process */
320 ksig.signb = SIGILL;
321 ksig.code = 0;
322 goto do_trapsignal;
323 }
324
325 /*
326 * The kernel never executes Thumb code.
327 */
328 printf("\ndata_abort_fault: Misaligned Kernel-mode "
329 "Program Counter\n");
330 dab_fatal(tf, fsr, far, td, &ksig);
331 }
332
333 /* See if the cpu state needs to be fixed up */
334 switch (data_abort_fixup(tf, fsr, far, td, &ksig)) {
335 case ABORT_FIXUP_RETURN:
336 return;
337 case ABORT_FIXUP_FAILED:
338 /* Deliver a SIGILL to the process */
339 ksig.signb = SIGILL;
340 ksig.code = 0;
341 goto do_trapsignal;
342 default:
343 break;
344 }
345
346 va = trunc_page((vm_offset_t)far);
347
348 /*
349 * It is only a kernel address space fault iff:
350 * 1. user == 0 and
351 * 2. pcb_onfault not set or
352 * 3. pcb_onfault set and not LDRT/LDRBT/STRT/STRBT instruction.
353 */
354 if (user == 0 && (va >= VM_MIN_KERNEL_ADDRESS ||
355 (va < VM_MIN_ADDRESS && vector_page == ARM_VECTORS_LOW)) &&
356 __predict_true((pcb->pcb_onfault == NULL ||
357 (ReadWord(tf->tf_pc) & 0x05200000) != 0x04200000))) {
358 map = kernel_map;
359
360 /* Was the fault due to the FPE/IPKDB ? */
361 if (__predict_false((tf->tf_spsr & PSR_MODE)==PSR_UND32_MODE)) {
362
363 /*
364 * Force exit via userret()
365 * This is necessary as the FPE is an extension to
366 * userland that actually runs in a priveledged mode
367 * but uses USR mode permissions for its accesses.
368 */
369 user = 1;
370 ksig.signb = SIGSEGV;
371 ksig.code = 0;
372 goto do_trapsignal;
373 }
374 } else {
375 map = &td->td_proc->p_vmspace->vm_map;
376 }
377
378 /*
379 * We need to know whether the page should be mapped
380 * as R or R/W. The MMU does not give us the info as
381 * to whether the fault was caused by a read or a write.
382 *
383 * However, we know that a permission fault can only be
384 * the result of a write to a read-only location, so
385 * we can deal with those quickly.
386 *
387 * Otherwise we need to disassemble the instruction
388 * responsible to determine if it was a write.
389 */
390 if (IS_PERMISSION_FAULT(fsr)) {
391 ftype = VM_PROT_WRITE;
392 } else {
393 u_int insn = ReadWord(tf->tf_pc);
394
395 if (((insn & 0x0c100000) == 0x04000000) || /* STR/STRB */
396 ((insn & 0x0e1000b0) == 0x000000b0) || /* STRH/STRD */
397 ((insn & 0x0a100000) == 0x08000000)) /* STM/CDT */
398 {
399 ftype = VM_PROT_WRITE;
400 }
401 else
402 if ((insn & 0x0fb00ff0) == 0x01000090) /* SWP */
403 ftype = VM_PROT_READ | VM_PROT_WRITE;
404 else
405 ftype = VM_PROT_READ;
406 }
407
408 /*
409 * See if the fault is as a result of ref/mod emulation,
410 * or domain mismatch.
411 */
412 #ifdef DEBUG
413 last_fault_code = fsr;
414 #endif
415 if (pmap_fault_fixup(vmspace_pmap(td->td_proc->p_vmspace), va, ftype,
416 user)) {
417 goto out;
418 }
419
420 onfault = pcb->pcb_onfault;
421 pcb->pcb_onfault = NULL;
422 if (map != kernel_map) {
423 PROC_LOCK(p);
424 p->p_lock++;
425 PROC_UNLOCK(p);
426 }
427 error = vm_fault(map, va, ftype, VM_FAULT_NORMAL);
428 pcb->pcb_onfault = onfault;
429
430 if (map != kernel_map) {
431 PROC_LOCK(p);
432 p->p_lock--;
433 PROC_UNLOCK(p);
434 }
435 if (__predict_true(error == 0))
436 goto out;
437 if (user == 0) {
438 if (pcb->pcb_onfault) {
439 tf->tf_r0 = error;
440 tf->tf_pc = (register_t)(intptr_t) pcb->pcb_onfault;
441 return;
442 }
443
444 printf("\nvm_fault(%p, %x, %x, 0) -> %x\n", map, va, ftype,
445 error);
446 dab_fatal(tf, fsr, far, td, &ksig);
447 }
448
449
450 if (error == ENOMEM) {
451 printf("VM: pid %d (%s), uid %d killed: "
452 "out of swap\n", td->td_proc->p_pid, td->td_name,
453 (td->td_proc->p_ucred) ?
454 td->td_proc->p_ucred->cr_uid : -1);
455 ksig.signb = SIGKILL;
456 } else {
457 ksig.signb = SIGSEGV;
458 }
459 ksig.code = 0;
460 do_trapsignal:
461 call_trapsignal(td, ksig.signb, ksig.code);
462 out:
463 /* If returning to user mode, make sure to invoke userret() */
464 if (user)
465 userret(td, tf);
466 }
467
468 /*
469 * dab_fatal() handles the following data aborts:
470 *
471 * FAULT_WRTBUF_0 - Vector Exception
472 * FAULT_WRTBUF_1 - Terminal Exception
473 *
474 * We should never see these on a properly functioning system.
475 *
476 * This function is also called by the other handlers if they
477 * detect a fatal problem.
478 *
479 * Note: If 'l' is NULL, we assume we're dealing with a prefetch abort.
480 */
481 static int
482 dab_fatal(trapframe_t *tf, u_int fsr, u_int far, struct thread *td, struct ksig *ksig)
483 {
484 const char *mode;
485
486 mode = TRAP_USERMODE(tf) ? "user" : "kernel";
487
488 disable_interrupts(I32_bit|F32_bit);
489 if (td != NULL) {
490 printf("Fatal %s mode data abort: '%s'\n", mode,
491 data_aborts[fsr & FAULT_TYPE_MASK].desc);
492 printf("trapframe: %p\nFSR=%08x, FAR=", tf, fsr);
493 if ((fsr & FAULT_IMPRECISE) == 0)
494 printf("%08x, ", far);
495 else
496 printf("Invalid, ");
497 printf("spsr=%08x\n", tf->tf_spsr);
498 } else {
499 printf("Fatal %s mode prefetch abort at 0x%08x\n",
500 mode, tf->tf_pc);
501 printf("trapframe: %p, spsr=%08x\n", tf, tf->tf_spsr);
502 }
503
504 printf("r0 =%08x, r1 =%08x, r2 =%08x, r3 =%08x\n",
505 tf->tf_r0, tf->tf_r1, tf->tf_r2, tf->tf_r3);
506 printf("r4 =%08x, r5 =%08x, r6 =%08x, r7 =%08x\n",
507 tf->tf_r4, tf->tf_r5, tf->tf_r6, tf->tf_r7);
508 printf("r8 =%08x, r9 =%08x, r10=%08x, r11=%08x\n",
509 tf->tf_r8, tf->tf_r9, tf->tf_r10, tf->tf_r11);
510 printf("r12=%08x, ", tf->tf_r12);
511
512 if (TRAP_USERMODE(tf))
513 printf("usp=%08x, ulr=%08x",
514 tf->tf_usr_sp, tf->tf_usr_lr);
515 else
516 printf("ssp=%08x, slr=%08x",
517 tf->tf_svc_sp, tf->tf_svc_lr);
518 printf(", pc =%08x\n\n", tf->tf_pc);
519
520 #ifdef KDB
521 if (debugger_on_panic || kdb_active)
522 kdb_trap(fsr, 0, tf);
523 #endif
524 panic("Fatal abort");
525 /*NOTREACHED*/
526 }
527
528 /*
529 * dab_align() handles the following data aborts:
530 *
531 * FAULT_ALIGN_0 - Alignment fault
532 * FAULT_ALIGN_1 - Alignment fault
533 *
534 * These faults are fatal if they happen in kernel mode. Otherwise, we
535 * deliver a bus error to the process.
536 */
537 static int
538 dab_align(trapframe_t *tf, u_int fsr, u_int far, struct thread *td, struct ksig *ksig)
539 {
540
541 /* Alignment faults are always fatal if they occur in kernel mode */
542 if (!TRAP_USERMODE(tf)) {
543 if (!td || !td->td_pcb->pcb_onfault)
544 dab_fatal(tf, fsr, far, td, ksig);
545 tf->tf_r0 = EFAULT;
546 tf->tf_pc = (int)td->td_pcb->pcb_onfault;
547 return (0);
548 }
549
550 /* pcb_onfault *must* be NULL at this point */
551
552 /* See if the cpu state needs to be fixed up */
553 (void) data_abort_fixup(tf, fsr, far, td, ksig);
554
555 /* Deliver a bus error signal to the process */
556 ksig->code = 0;
557 ksig->signb = SIGBUS;
558 td->td_frame = tf;
559
560 return (1);
561 }
562
563 /*
564 * dab_buserr() handles the following data aborts:
565 *
566 * FAULT_BUSERR_0 - External Abort on Linefetch -- Section
567 * FAULT_BUSERR_1 - External Abort on Linefetch -- Page
568 * FAULT_BUSERR_2 - External Abort on Non-linefetch -- Section
569 * FAULT_BUSERR_3 - External Abort on Non-linefetch -- Page
570 * FAULT_BUSTRNL1 - External abort on Translation -- Level 1
571 * FAULT_BUSTRNL2 - External abort on Translation -- Level 2
572 *
573 * If pcb_onfault is set, flag the fault and return to the handler.
574 * If the fault occurred in user mode, give the process a SIGBUS.
575 *
576 * Note: On XScale, FAULT_BUSERR_0, FAULT_BUSERR_1, and FAULT_BUSERR_2
577 * can be flagged as imprecise in the FSR. This causes a real headache
578 * since some of the machine state is lost. In this case, tf->tf_pc
579 * may not actually point to the offending instruction. In fact, if
580 * we've taken a double abort fault, it generally points somewhere near
581 * the top of "data_abort_entry" in exception.S.
582 *
583 * In all other cases, these data aborts are considered fatal.
584 */
585 static int
586 dab_buserr(trapframe_t *tf, u_int fsr, u_int far, struct thread *td, struct ksig *ksig)
587 {
588 struct pcb *pcb = td->td_pcb;
589
590 #ifdef __XSCALE__
591 if ((fsr & FAULT_IMPRECISE) != 0 &&
592 (tf->tf_spsr & PSR_MODE) == PSR_ABT32_MODE) {
593 /*
594 * Oops, an imprecise, double abort fault. We've lost the
595 * r14_abt/spsr_abt values corresponding to the original
596 * abort, and the spsr saved in the trapframe indicates
597 * ABT mode.
598 */
599 tf->tf_spsr &= ~PSR_MODE;
600
601 /*
602 * We use a simple heuristic to determine if the double abort
603 * happened as a result of a kernel or user mode access.
604 * If the current trapframe is at the top of the kernel stack,
605 * the fault _must_ have come from user mode.
606 */
607 if (tf != ((trapframe_t *)pcb->un_32.pcb32_sp) - 1) {
608 /*
609 * Kernel mode. We're either about to die a
610 * spectacular death, or pcb_onfault will come
611 * to our rescue. Either way, the current value
612 * of tf->tf_pc is irrelevant.
613 */
614 tf->tf_spsr |= PSR_SVC32_MODE;
615 if (pcb->pcb_onfault == NULL)
616 printf("\nKernel mode double abort!\n");
617 } else {
618 /*
619 * User mode. We've lost the program counter at the
620 * time of the fault (not that it was accurate anyway;
621 * it's not called an imprecise fault for nothing).
622 * About all we can do is copy r14_usr to tf_pc and
623 * hope for the best. The process is about to get a
624 * SIGBUS, so it's probably history anyway.
625 */
626 tf->tf_spsr |= PSR_USR32_MODE;
627 tf->tf_pc = tf->tf_usr_lr;
628 }
629 }
630
631 /* FAR is invalid for imprecise exceptions */
632 if ((fsr & FAULT_IMPRECISE) != 0)
633 far = 0;
634 #endif /* __XSCALE__ */
635
636 if (pcb->pcb_onfault) {
637 tf->tf_r0 = EFAULT;
638 tf->tf_pc = (register_t)(intptr_t) pcb->pcb_onfault;
639 return (0);
640 }
641
642 /* See if the cpu state needs to be fixed up */
643 (void) data_abort_fixup(tf, fsr, far, td, ksig);
644
645 /*
646 * At this point, if the fault happened in kernel mode, we're toast
647 */
648 if (!TRAP_USERMODE(tf))
649 dab_fatal(tf, fsr, far, td, ksig);
650
651 /* Deliver a bus error signal to the process */
652 ksig->signb = SIGBUS;
653 ksig->code = 0;
654 td->td_frame = tf;
655
656 return (1);
657 }
658
659 static __inline int
660 prefetch_abort_fixup(trapframe_t *tf, struct ksig *ksig)
661 {
662 #ifdef CPU_ABORT_FIXUP_REQUIRED
663 int error;
664
665 /* Call the cpu specific prefetch abort fixup routine */
666 error = cpu_prefetchabt_fixup(tf);
667 if (__predict_true(error != ABORT_FIXUP_FAILED))
668 return (error);
669
670 /*
671 * Oops, couldn't fix up the instruction
672 */
673 printf(
674 "prefetch_abort_fixup: fixup for %s mode prefetch abort failed.\n",
675 TRAP_USERMODE(tf) ? "user" : "kernel");
676 printf("pc = 0x%08x, opcode 0x%08x, insn = ", tf->tf_pc,
677 *((u_int *)tf->tf_pc));
678 disassemble(tf->tf_pc);
679
680 /* Die now if this happened in kernel mode */
681 if (!TRAP_USERMODE(tf))
682 dab_fatal(tf, 0, tf->tf_pc, NULL, ksig);
683
684 return (error);
685 #else
686 return (ABORT_FIXUP_OK);
687 #endif /* CPU_ABORT_FIXUP_REQUIRED */
688 }
689
690 /*
691 * void prefetch_abort_handler(trapframe_t *tf)
692 *
693 * Abort handler called when instruction execution occurs at
694 * a non existent or restricted (access permissions) memory page.
695 * If the address is invalid and we were in SVC mode then panic as
696 * the kernel should never prefetch abort.
697 * If the address is invalid and the page is mapped then the user process
698 * does no have read permission so send it a signal.
699 * Otherwise fault the page in and try again.
700 */
701 void
702 prefetch_abort_handler(trapframe_t *tf)
703 {
704 struct thread *td;
705 struct proc * p;
706 struct vm_map *map;
707 vm_offset_t fault_pc, va;
708 int error = 0;
709 struct ksig ksig;
710
711
712 #if 0
713 /* Update vmmeter statistics */
714 uvmexp.traps++;
715 #endif
716 #if 0
717 printf("prefetch abort handler: %p %p\n", (void*)tf->tf_pc,
718 (void*)tf->tf_usr_lr);
719 #endif
720
721 td = curthread;
722 p = td->td_proc;
723 PCPU_INC(cnt.v_trap);
724
725 if (TRAP_USERMODE(tf)) {
726 td->td_frame = tf;
727 if (td->td_ucred != td->td_proc->p_ucred)
728 cred_update_thread(td);
729 }
730 fault_pc = tf->tf_pc;
731 if (td->td_md.md_spinlock_count == 0) {
732 if (__predict_true(tf->tf_spsr & I32_bit) == 0)
733 enable_interrupts(I32_bit);
734 if (__predict_true(tf->tf_spsr & F32_bit) == 0)
735 enable_interrupts(F32_bit);
736 }
737
738 /* See if the cpu state needs to be fixed up */
739 switch (prefetch_abort_fixup(tf, &ksig)) {
740 case ABORT_FIXUP_RETURN:
741 return;
742 case ABORT_FIXUP_FAILED:
743 /* Deliver a SIGILL to the process */
744 ksig.signb = SIGILL;
745 ksig.code = 0;
746 td->td_frame = tf;
747 goto do_trapsignal;
748 default:
749 break;
750 }
751
752 /* Prefetch aborts cannot happen in kernel mode */
753 if (__predict_false(!TRAP_USERMODE(tf)))
754 dab_fatal(tf, 0, tf->tf_pc, NULL, &ksig);
755 td->td_pticks = 0;
756
757
758 /* Ok validate the address, can only execute in USER space */
759 if (__predict_false(fault_pc >= VM_MAXUSER_ADDRESS ||
760 (fault_pc < VM_MIN_ADDRESS && vector_page == ARM_VECTORS_LOW))) {
761 ksig.signb = SIGSEGV;
762 ksig.code = 0;
763 goto do_trapsignal;
764 }
765
766 map = &td->td_proc->p_vmspace->vm_map;
767 va = trunc_page(fault_pc);
768
769 /*
770 * See if the pmap can handle this fault on its own...
771 */
772 #ifdef DEBUG
773 last_fault_code = -1;
774 #endif
775 if (pmap_fault_fixup(map->pmap, va, VM_PROT_READ, 1))
776 goto out;
777
778 if (map != kernel_map) {
779 PROC_LOCK(p);
780 p->p_lock++;
781 PROC_UNLOCK(p);
782 }
783
784 error = vm_fault(map, va, VM_PROT_READ | VM_PROT_EXECUTE,
785 VM_FAULT_NORMAL);
786 if (map != kernel_map) {
787 PROC_LOCK(p);
788 p->p_lock--;
789 PROC_UNLOCK(p);
790 }
791
792 if (__predict_true(error == 0))
793 goto out;
794
795 if (error == ENOMEM) {
796 printf("VM: pid %d (%s), uid %d killed: "
797 "out of swap\n", td->td_proc->p_pid, td->td_name,
798 (td->td_proc->p_ucred) ?
799 td->td_proc->p_ucred->cr_uid : -1);
800 ksig.signb = SIGKILL;
801 } else {
802 ksig.signb = SIGSEGV;
803 }
804 ksig.code = 0;
805
806 do_trapsignal:
807 call_trapsignal(td, ksig.signb, ksig.code);
808
809 out:
810 userret(td, tf);
811
812 }
813
814 extern int badaddr_read_1(const uint8_t *, uint8_t *);
815 extern int badaddr_read_2(const uint16_t *, uint16_t *);
816 extern int badaddr_read_4(const uint32_t *, uint32_t *);
817 /*
818 * Tentatively read an 8, 16, or 32-bit value from 'addr'.
819 * If the read succeeds, the value is written to 'rptr' and zero is returned.
820 * Else, return EFAULT.
821 */
822 int
823 badaddr_read(void *addr, size_t size, void *rptr)
824 {
825 union {
826 uint8_t v1;
827 uint16_t v2;
828 uint32_t v4;
829 } u;
830 int rv;
831
832 cpu_drain_writebuf();
833
834 /* Read from the test address. */
835 switch (size) {
836 case sizeof(uint8_t):
837 rv = badaddr_read_1(addr, &u.v1);
838 if (rv == 0 && rptr)
839 *(uint8_t *) rptr = u.v1;
840 break;
841
842 case sizeof(uint16_t):
843 rv = badaddr_read_2(addr, &u.v2);
844 if (rv == 0 && rptr)
845 *(uint16_t *) rptr = u.v2;
846 break;
847
848 case sizeof(uint32_t):
849 rv = badaddr_read_4(addr, &u.v4);
850 if (rv == 0 && rptr)
851 *(uint32_t *) rptr = u.v4;
852 break;
853
854 default:
855 panic("badaddr: invalid size (%lu)", (u_long) size);
856 }
857
858 /* Return EFAULT if the address was invalid, else zero */
859 return (rv);
860 }
861
862 int
863 cpu_fetch_syscall_args(struct thread *td, struct syscall_args *sa)
864 {
865 struct proc *p;
866 register_t *ap;
867 int error;
868
869 sa->code = sa->insn & 0x000fffff;
870 ap = &td->td_frame->tf_r0;
871 if (sa->code == SYS_syscall) {
872 sa->code = *ap++;
873 sa->nap--;
874 } else if (sa->code == SYS___syscall) {
875 sa->code = ap[_QUAD_LOWWORD];
876 sa->nap -= 2;
877 ap += 2;
878 }
879 p = td->td_proc;
880 if (p->p_sysent->sv_mask)
881 sa->code &= p->p_sysent->sv_mask;
882 if (sa->code >= p->p_sysent->sv_size)
883 sa->callp = &p->p_sysent->sv_table[0];
884 else
885 sa->callp = &p->p_sysent->sv_table[sa->code];
886 sa->narg = sa->callp->sy_narg;
887 error = 0;
888 memcpy(sa->args, ap, sa->nap * sizeof(register_t));
889 if (sa->narg > sa->nap) {
890 error = copyin((void *)td->td_frame->tf_usr_sp, sa->args +
891 sa->nap, (sa->narg - sa->nap) * sizeof(register_t));
892 }
893 if (error == 0) {
894 td->td_retval[0] = 0;
895 td->td_retval[1] = 0;
896 }
897 return (error);
898 }
899
900 #include "../../kern/subr_syscall.c"
901
902 static void
903 syscall(struct thread *td, trapframe_t *frame, u_int32_t insn)
904 {
905 struct syscall_args sa;
906 int error;
907
908 td->td_frame = frame;
909 sa.insn = insn;
910 switch (insn & SWI_OS_MASK) {
911 case 0: /* XXX: we need our own one. */
912 sa.nap = 4;
913 break;
914 default:
915 call_trapsignal(td, SIGILL, 0);
916 userret(td, frame);
917 return;
918 }
919
920 error = syscallenter(td, &sa);
921 KASSERT(error != 0 || td->td_ar == NULL,
922 ("returning from syscall with td_ar set!"));
923 syscallret(td, error, &sa);
924 }
925
926 void
927 swi_handler(trapframe_t *frame)
928 {
929 struct thread *td = curthread;
930 uint32_t insn;
931
932 td->td_frame = frame;
933
934 td->td_pticks = 0;
935 /*
936 * Make sure the program counter is correctly aligned so we
937 * don't take an alignment fault trying to read the opcode.
938 */
939 if (__predict_false(((frame->tf_pc - INSN_SIZE) & 3) != 0)) {
940 call_trapsignal(td, SIGILL, 0);
941 userret(td, frame);
942 return;
943 }
944 insn = *(u_int32_t *)(frame->tf_pc - INSN_SIZE);
945 /*
946 * Enable interrupts if they were enabled before the exception.
947 * Since all syscalls *should* come from user mode it will always
948 * be safe to enable them, but check anyway.
949 */
950 if (td->td_md.md_spinlock_count == 0) {
951 if (__predict_true(frame->tf_spsr & I32_bit) == 0)
952 enable_interrupts(I32_bit);
953 if (__predict_true(frame->tf_spsr & F32_bit) == 0)
954 enable_interrupts(F32_bit);
955 }
956
957 syscall(td, frame, insn);
958 }
959
Cache object: e3b2a4782b780eed7fdd7adbac5e06b5
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