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: releng/10.0/sys/arm/arm/trap.c 253142 2013-07-10 10:15:38Z ray $");
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 #if (ARM_MMU_V6 + ARM_MMU_V7) != 0
164 {NULL, "Translation Flag Fault"},
165 #else
166 {dab_buserr, "External Linefetch Abort (P)"},
167 #endif
168 {NULL, "Translation Fault (P)"},
169 {dab_buserr, "External Non-Linefetch Abort (S)"},
170 {NULL, "Domain Fault (S)"},
171 {dab_buserr, "External Non-Linefetch Abort (P)"},
172 {NULL, "Domain Fault (P)"},
173 {dab_buserr, "External Translation Abort (L1)"},
174 {NULL, "Permission Fault (S)"},
175 {dab_buserr, "External Translation Abort (L2)"},
176 {NULL, "Permission Fault (P)"}
177 };
178
179 /* Determine if a fault came from user mode */
180 #define TRAP_USERMODE(tf) ((tf->tf_spsr & PSR_MODE) == PSR_USR32_MODE)
181
182 /* Determine if 'x' is a permission fault */
183 #define IS_PERMISSION_FAULT(x) \
184 (((1 << ((x) & FAULT_TYPE_MASK)) & \
185 ((1 << FAULT_PERM_P) | (1 << FAULT_PERM_S))) != 0)
186
187 static __inline void
188 call_trapsignal(struct thread *td, int sig, u_long code)
189 {
190 ksiginfo_t ksi;
191
192 ksiginfo_init_trap(&ksi);
193 ksi.ksi_signo = sig;
194 ksi.ksi_code = (int)code;
195 trapsignal(td, &ksi);
196 }
197
198 static __inline int
199 data_abort_fixup(trapframe_t *tf, u_int fsr, u_int far, struct thread *td, struct ksig *ksig)
200 {
201 #ifdef CPU_ABORT_FIXUP_REQUIRED
202 int error;
203
204 /* Call the cpu specific data abort fixup routine */
205 error = cpu_dataabt_fixup(tf);
206 if (__predict_true(error != ABORT_FIXUP_FAILED))
207 return (error);
208
209 /*
210 * Oops, couldn't fix up the instruction
211 */
212 printf("data_abort_fixup: fixup for %s mode data abort failed.\n",
213 TRAP_USERMODE(tf) ? "user" : "kernel");
214 printf("pc = 0x%08x, opcode 0x%08x, insn = ", tf->tf_pc,
215 *((u_int *)tf->tf_pc));
216 disassemble(tf->tf_pc);
217
218 /* Die now if this happened in kernel mode */
219 if (!TRAP_USERMODE(tf))
220 dab_fatal(tf, fsr, far, td, NULL, ksig);
221
222 return (error);
223 #else
224 return (ABORT_FIXUP_OK);
225 #endif /* CPU_ABORT_FIXUP_REQUIRED */
226 }
227
228 void
229 data_abort_handler(trapframe_t *tf)
230 {
231 struct vm_map *map;
232 struct pcb *pcb;
233 struct thread *td;
234 u_int user, far, fsr;
235 vm_prot_t ftype;
236 void *onfault;
237 vm_offset_t va;
238 int error = 0;
239 struct ksig ksig;
240 struct proc *p;
241
242
243 /* Grab FAR/FSR before enabling interrupts */
244 far = cpu_faultaddress();
245 fsr = cpu_faultstatus();
246 #if 0
247 printf("data abort: fault address=%p (from pc=%p lr=%p)\n",
248 (void*)far, (void*)tf->tf_pc, (void*)tf->tf_svc_lr);
249 #endif
250
251 /* Update vmmeter statistics */
252 #if 0
253 vmexp.traps++;
254 #endif
255
256 td = curthread;
257 p = td->td_proc;
258
259 PCPU_INC(cnt.v_trap);
260 /* Data abort came from user mode? */
261 user = TRAP_USERMODE(tf);
262
263 if (user) {
264 td->td_pticks = 0;
265 td->td_frame = tf;
266 if (td->td_ucred != td->td_proc->p_ucred)
267 cred_update_thread(td);
268
269 }
270 /* Grab the current pcb */
271 pcb = td->td_pcb;
272 /* Re-enable interrupts if they were enabled previously */
273 if (td->td_md.md_spinlock_count == 0) {
274 if (__predict_true(tf->tf_spsr & I32_bit) == 0)
275 enable_interrupts(I32_bit);
276 if (__predict_true(tf->tf_spsr & F32_bit) == 0)
277 enable_interrupts(F32_bit);
278 }
279
280
281 /* Invoke the appropriate handler, if necessary */
282 if (__predict_false(data_aborts[fsr & FAULT_TYPE_MASK].func != NULL)) {
283 if ((data_aborts[fsr & FAULT_TYPE_MASK].func)(tf, fsr, far,
284 td, &ksig)) {
285 goto do_trapsignal;
286 }
287 goto out;
288 }
289
290 /*
291 * At this point, we're dealing with one of the following data aborts:
292 *
293 * FAULT_TRANS_S - Translation -- Section
294 * FAULT_TRANS_P - Translation -- Page
295 * FAULT_DOMAIN_S - Domain -- Section
296 * FAULT_DOMAIN_P - Domain -- Page
297 * FAULT_PERM_S - Permission -- Section
298 * FAULT_PERM_P - Permission -- Page
299 *
300 * These are the main virtual memory-related faults signalled by
301 * the MMU.
302 */
303
304 /* fusubailout is used by [fs]uswintr to avoid page faulting */
305 if (__predict_false(pcb->pcb_onfault == fusubailout)) {
306 tf->tf_r0 = EFAULT;
307 tf->tf_pc = (register_t)(intptr_t) pcb->pcb_onfault;
308 return;
309 }
310
311 /*
312 * Make sure the Program Counter is sane. We could fall foul of
313 * someone executing Thumb code, in which case the PC might not
314 * be word-aligned. This would cause a kernel alignment fault
315 * further down if we have to decode the current instruction.
316 * XXX: It would be nice to be able to support Thumb at some point.
317 */
318 if (__predict_false((tf->tf_pc & 3) != 0)) {
319 if (user) {
320 /*
321 * Give the user an illegal instruction signal.
322 */
323 /* Deliver a SIGILL to the process */
324 ksig.signb = SIGILL;
325 ksig.code = 0;
326 goto do_trapsignal;
327 }
328
329 /*
330 * The kernel never executes Thumb code.
331 */
332 printf("\ndata_abort_fault: Misaligned Kernel-mode "
333 "Program Counter\n");
334 dab_fatal(tf, fsr, far, td, &ksig);
335 }
336
337 /* See if the cpu state needs to be fixed up */
338 switch (data_abort_fixup(tf, fsr, far, td, &ksig)) {
339 case ABORT_FIXUP_RETURN:
340 return;
341 case ABORT_FIXUP_FAILED:
342 /* Deliver a SIGILL to the process */
343 ksig.signb = SIGILL;
344 ksig.code = 0;
345 goto do_trapsignal;
346 default:
347 break;
348 }
349
350 va = trunc_page((vm_offset_t)far);
351
352 /*
353 * It is only a kernel address space fault iff:
354 * 1. user == 0 and
355 * 2. pcb_onfault not set or
356 * 3. pcb_onfault set and not LDRT/LDRBT/STRT/STRBT instruction.
357 */
358 if (user == 0 && (va >= VM_MIN_KERNEL_ADDRESS ||
359 (va < VM_MIN_ADDRESS && vector_page == ARM_VECTORS_LOW)) &&
360 __predict_true((pcb->pcb_onfault == NULL ||
361 (ReadWord(tf->tf_pc) & 0x05200000) != 0x04200000))) {
362 map = kernel_map;
363
364 /* Was the fault due to the FPE/IPKDB ? */
365 if (__predict_false((tf->tf_spsr & PSR_MODE)==PSR_UND32_MODE)) {
366
367 /*
368 * Force exit via userret()
369 * This is necessary as the FPE is an extension to
370 * userland that actually runs in a priveledged mode
371 * but uses USR mode permissions for its accesses.
372 */
373 user = 1;
374 ksig.signb = SIGSEGV;
375 ksig.code = 0;
376 goto do_trapsignal;
377 }
378 } else {
379 map = &td->td_proc->p_vmspace->vm_map;
380 }
381
382 /*
383 * We need to know whether the page should be mapped
384 * as R or R/W. The MMU does not give us the info as
385 * to whether the fault was caused by a read or a write.
386 *
387 * However, we know that a permission fault can only be
388 * the result of a write to a read-only location, so
389 * we can deal with those quickly.
390 *
391 * Otherwise we need to disassemble the instruction
392 * responsible to determine if it was a write.
393 */
394 if (IS_PERMISSION_FAULT(fsr))
395 ftype = VM_PROT_WRITE;
396 else {
397 u_int insn = ReadWord(tf->tf_pc);
398
399 if (((insn & 0x0c100000) == 0x04000000) || /* STR/STRB */
400 ((insn & 0x0e1000b0) == 0x000000b0) || /* STRH/STRD */
401 ((insn & 0x0a100000) == 0x08000000)) { /* STM/CDT */
402 ftype = VM_PROT_WRITE;
403 } else {
404 if ((insn & 0x0fb00ff0) == 0x01000090) /* SWP */
405 ftype = VM_PROT_READ | VM_PROT_WRITE;
406 else
407 ftype = VM_PROT_READ;
408 }
409 }
410
411 /*
412 * See if the fault is as a result of ref/mod emulation,
413 * or domain mismatch.
414 */
415 #ifdef DEBUG
416 last_fault_code = fsr;
417 #endif
418 if (pmap_fault_fixup(vmspace_pmap(td->td_proc->p_vmspace), va, ftype,
419 user)) {
420 goto out;
421 }
422
423 onfault = pcb->pcb_onfault;
424 pcb->pcb_onfault = NULL;
425 if (map != kernel_map) {
426 PROC_LOCK(p);
427 p->p_lock++;
428 PROC_UNLOCK(p);
429 }
430 error = vm_fault(map, va, ftype, VM_FAULT_NORMAL);
431 pcb->pcb_onfault = onfault;
432
433 if (map != kernel_map) {
434 PROC_LOCK(p);
435 p->p_lock--;
436 PROC_UNLOCK(p);
437 }
438 if (__predict_true(error == 0))
439 goto out;
440 if (user == 0) {
441 if (pcb->pcb_onfault) {
442 tf->tf_r0 = error;
443 tf->tf_pc = (register_t)(intptr_t) pcb->pcb_onfault;
444 return;
445 }
446
447 printf("\nvm_fault(%p, %x, %x, 0) -> %x\n", map, va, ftype,
448 error);
449 dab_fatal(tf, fsr, far, td, &ksig);
450 }
451
452
453 if (error == ENOMEM) {
454 printf("VM: pid %d (%s), uid %d killed: "
455 "out of swap\n", td->td_proc->p_pid, td->td_name,
456 (td->td_proc->p_ucred) ?
457 td->td_proc->p_ucred->cr_uid : -1);
458 ksig.signb = SIGKILL;
459 } else {
460 ksig.signb = SIGSEGV;
461 }
462 ksig.code = 0;
463 do_trapsignal:
464 call_trapsignal(td, ksig.signb, ksig.code);
465 out:
466 /* If returning to user mode, make sure to invoke userret() */
467 if (user)
468 userret(td, tf);
469 }
470
471 /*
472 * dab_fatal() handles the following data aborts:
473 *
474 * FAULT_WRTBUF_0 - Vector Exception
475 * FAULT_WRTBUF_1 - Terminal Exception
476 *
477 * We should never see these on a properly functioning system.
478 *
479 * This function is also called by the other handlers if they
480 * detect a fatal problem.
481 *
482 * Note: If 'l' is NULL, we assume we're dealing with a prefetch abort.
483 */
484 static int
485 dab_fatal(trapframe_t *tf, u_int fsr, u_int far, struct thread *td, struct ksig *ksig)
486 {
487 const char *mode;
488
489 mode = TRAP_USERMODE(tf) ? "user" : "kernel";
490
491 disable_interrupts(I32_bit|F32_bit);
492 if (td != NULL) {
493 printf("Fatal %s mode data abort: '%s'\n", mode,
494 data_aborts[fsr & FAULT_TYPE_MASK].desc);
495 printf("trapframe: %p\nFSR=%08x, FAR=", tf, fsr);
496 if ((fsr & FAULT_IMPRECISE) == 0)
497 printf("%08x, ", far);
498 else
499 printf("Invalid, ");
500 printf("spsr=%08x\n", tf->tf_spsr);
501 } else {
502 printf("Fatal %s mode prefetch abort at 0x%08x\n",
503 mode, tf->tf_pc);
504 printf("trapframe: %p, spsr=%08x\n", tf, tf->tf_spsr);
505 }
506
507 printf("r0 =%08x, r1 =%08x, r2 =%08x, r3 =%08x\n",
508 tf->tf_r0, tf->tf_r1, tf->tf_r2, tf->tf_r3);
509 printf("r4 =%08x, r5 =%08x, r6 =%08x, r7 =%08x\n",
510 tf->tf_r4, tf->tf_r5, tf->tf_r6, tf->tf_r7);
511 printf("r8 =%08x, r9 =%08x, r10=%08x, r11=%08x\n",
512 tf->tf_r8, tf->tf_r9, tf->tf_r10, tf->tf_r11);
513 printf("r12=%08x, ", tf->tf_r12);
514
515 if (TRAP_USERMODE(tf))
516 printf("usp=%08x, ulr=%08x",
517 tf->tf_usr_sp, tf->tf_usr_lr);
518 else
519 printf("ssp=%08x, slr=%08x",
520 tf->tf_svc_sp, tf->tf_svc_lr);
521 printf(", pc =%08x\n\n", tf->tf_pc);
522
523 #ifdef KDB
524 if (debugger_on_panic || kdb_active)
525 kdb_trap(fsr, 0, tf);
526 #endif
527 panic("Fatal abort");
528 /*NOTREACHED*/
529 }
530
531 /*
532 * dab_align() handles the following data aborts:
533 *
534 * FAULT_ALIGN_0 - Alignment fault
535 * FAULT_ALIGN_1 - Alignment fault
536 *
537 * These faults are fatal if they happen in kernel mode. Otherwise, we
538 * deliver a bus error to the process.
539 */
540 static int
541 dab_align(trapframe_t *tf, u_int fsr, u_int far, struct thread *td, struct ksig *ksig)
542 {
543
544 /* Alignment faults are always fatal if they occur in kernel mode */
545 if (!TRAP_USERMODE(tf)) {
546 if (!td || !td->td_pcb->pcb_onfault)
547 dab_fatal(tf, fsr, far, td, ksig);
548 tf->tf_r0 = EFAULT;
549 tf->tf_pc = (int)td->td_pcb->pcb_onfault;
550 return (0);
551 }
552
553 /* pcb_onfault *must* be NULL at this point */
554
555 /* See if the cpu state needs to be fixed up */
556 (void) data_abort_fixup(tf, fsr, far, td, ksig);
557
558 /* Deliver a bus error signal to the process */
559 ksig->code = 0;
560 ksig->signb = SIGBUS;
561 td->td_frame = tf;
562
563 return (1);
564 }
565
566 /*
567 * dab_buserr() handles the following data aborts:
568 *
569 * FAULT_BUSERR_0 - External Abort on Linefetch -- Section
570 * FAULT_BUSERR_1 - External Abort on Linefetch -- Page
571 * FAULT_BUSERR_2 - External Abort on Non-linefetch -- Section
572 * FAULT_BUSERR_3 - External Abort on Non-linefetch -- Page
573 * FAULT_BUSTRNL1 - External abort on Translation -- Level 1
574 * FAULT_BUSTRNL2 - External abort on Translation -- Level 2
575 *
576 * If pcb_onfault is set, flag the fault and return to the handler.
577 * If the fault occurred in user mode, give the process a SIGBUS.
578 *
579 * Note: On XScale, FAULT_BUSERR_0, FAULT_BUSERR_1, and FAULT_BUSERR_2
580 * can be flagged as imprecise in the FSR. This causes a real headache
581 * since some of the machine state is lost. In this case, tf->tf_pc
582 * may not actually point to the offending instruction. In fact, if
583 * we've taken a double abort fault, it generally points somewhere near
584 * the top of "data_abort_entry" in exception.S.
585 *
586 * In all other cases, these data aborts are considered fatal.
587 */
588 static int
589 dab_buserr(trapframe_t *tf, u_int fsr, u_int far, struct thread *td, struct ksig *ksig)
590 {
591 struct pcb *pcb = td->td_pcb;
592
593 #ifdef __XSCALE__
594 if ((fsr & FAULT_IMPRECISE) != 0 &&
595 (tf->tf_spsr & PSR_MODE) == PSR_ABT32_MODE) {
596 /*
597 * Oops, an imprecise, double abort fault. We've lost the
598 * r14_abt/spsr_abt values corresponding to the original
599 * abort, and the spsr saved in the trapframe indicates
600 * ABT mode.
601 */
602 tf->tf_spsr &= ~PSR_MODE;
603
604 /*
605 * We use a simple heuristic to determine if the double abort
606 * happened as a result of a kernel or user mode access.
607 * If the current trapframe is at the top of the kernel stack,
608 * the fault _must_ have come from user mode.
609 */
610 if (tf != ((trapframe_t *)pcb->un_32.pcb32_sp) - 1) {
611 /*
612 * Kernel mode. We're either about to die a
613 * spectacular death, or pcb_onfault will come
614 * to our rescue. Either way, the current value
615 * of tf->tf_pc is irrelevant.
616 */
617 tf->tf_spsr |= PSR_SVC32_MODE;
618 if (pcb->pcb_onfault == NULL)
619 printf("\nKernel mode double abort!\n");
620 } else {
621 /*
622 * User mode. We've lost the program counter at the
623 * time of the fault (not that it was accurate anyway;
624 * it's not called an imprecise fault for nothing).
625 * About all we can do is copy r14_usr to tf_pc and
626 * hope for the best. The process is about to get a
627 * SIGBUS, so it's probably history anyway.
628 */
629 tf->tf_spsr |= PSR_USR32_MODE;
630 tf->tf_pc = tf->tf_usr_lr;
631 }
632 }
633
634 /* FAR is invalid for imprecise exceptions */
635 if ((fsr & FAULT_IMPRECISE) != 0)
636 far = 0;
637 #endif /* __XSCALE__ */
638
639 if (pcb->pcb_onfault) {
640 tf->tf_r0 = EFAULT;
641 tf->tf_pc = (register_t)(intptr_t) pcb->pcb_onfault;
642 return (0);
643 }
644
645 /* See if the cpu state needs to be fixed up */
646 (void) data_abort_fixup(tf, fsr, far, td, ksig);
647
648 /*
649 * At this point, if the fault happened in kernel mode, we're toast
650 */
651 if (!TRAP_USERMODE(tf))
652 dab_fatal(tf, fsr, far, td, ksig);
653
654 /* Deliver a bus error signal to the process */
655 ksig->signb = SIGBUS;
656 ksig->code = 0;
657 td->td_frame = tf;
658
659 return (1);
660 }
661
662 static __inline int
663 prefetch_abort_fixup(trapframe_t *tf, struct ksig *ksig)
664 {
665 #ifdef CPU_ABORT_FIXUP_REQUIRED
666 int error;
667
668 /* Call the cpu specific prefetch abort fixup routine */
669 error = cpu_prefetchabt_fixup(tf);
670 if (__predict_true(error != ABORT_FIXUP_FAILED))
671 return (error);
672
673 /*
674 * Oops, couldn't fix up the instruction
675 */
676 printf(
677 "prefetch_abort_fixup: fixup for %s mode prefetch abort failed.\n",
678 TRAP_USERMODE(tf) ? "user" : "kernel");
679 printf("pc = 0x%08x, opcode 0x%08x, insn = ", tf->tf_pc,
680 *((u_int *)tf->tf_pc));
681 disassemble(tf->tf_pc);
682
683 /* Die now if this happened in kernel mode */
684 if (!TRAP_USERMODE(tf))
685 dab_fatal(tf, 0, tf->tf_pc, NULL, ksig);
686
687 return (error);
688 #else
689 return (ABORT_FIXUP_OK);
690 #endif /* CPU_ABORT_FIXUP_REQUIRED */
691 }
692
693 /*
694 * void prefetch_abort_handler(trapframe_t *tf)
695 *
696 * Abort handler called when instruction execution occurs at
697 * a non existent or restricted (access permissions) memory page.
698 * If the address is invalid and we were in SVC mode then panic as
699 * the kernel should never prefetch abort.
700 * If the address is invalid and the page is mapped then the user process
701 * does no have read permission so send it a signal.
702 * Otherwise fault the page in and try again.
703 */
704 void
705 prefetch_abort_handler(trapframe_t *tf)
706 {
707 struct thread *td;
708 struct proc * p;
709 struct vm_map *map;
710 vm_offset_t fault_pc, va;
711 int error = 0;
712 struct ksig ksig;
713
714
715 #if 0
716 /* Update vmmeter statistics */
717 uvmexp.traps++;
718 #endif
719 #if 0
720 printf("prefetch abort handler: %p %p\n", (void*)tf->tf_pc,
721 (void*)tf->tf_usr_lr);
722 #endif
723
724 td = curthread;
725 p = td->td_proc;
726 PCPU_INC(cnt.v_trap);
727
728 if (TRAP_USERMODE(tf)) {
729 td->td_frame = tf;
730 if (td->td_ucred != td->td_proc->p_ucred)
731 cred_update_thread(td);
732 }
733 fault_pc = tf->tf_pc;
734 if (td->td_md.md_spinlock_count == 0) {
735 if (__predict_true(tf->tf_spsr & I32_bit) == 0)
736 enable_interrupts(I32_bit);
737 if (__predict_true(tf->tf_spsr & F32_bit) == 0)
738 enable_interrupts(F32_bit);
739 }
740
741 /* See if the cpu state needs to be fixed up */
742 switch (prefetch_abort_fixup(tf, &ksig)) {
743 case ABORT_FIXUP_RETURN:
744 return;
745 case ABORT_FIXUP_FAILED:
746 /* Deliver a SIGILL to the process */
747 ksig.signb = SIGILL;
748 ksig.code = 0;
749 td->td_frame = tf;
750 goto do_trapsignal;
751 default:
752 break;
753 }
754
755 /* Prefetch aborts cannot happen in kernel mode */
756 if (__predict_false(!TRAP_USERMODE(tf)))
757 dab_fatal(tf, 0, tf->tf_pc, NULL, &ksig);
758 td->td_pticks = 0;
759
760
761 /* Ok validate the address, can only execute in USER space */
762 if (__predict_false(fault_pc >= VM_MAXUSER_ADDRESS ||
763 (fault_pc < VM_MIN_ADDRESS && vector_page == ARM_VECTORS_LOW))) {
764 ksig.signb = SIGSEGV;
765 ksig.code = 0;
766 goto do_trapsignal;
767 }
768
769 map = &td->td_proc->p_vmspace->vm_map;
770 va = trunc_page(fault_pc);
771
772 /*
773 * See if the pmap can handle this fault on its own...
774 */
775 #ifdef DEBUG
776 last_fault_code = -1;
777 #endif
778 if (pmap_fault_fixup(map->pmap, va, VM_PROT_READ, 1))
779 goto out;
780
781 if (map != kernel_map) {
782 PROC_LOCK(p);
783 p->p_lock++;
784 PROC_UNLOCK(p);
785 }
786
787 error = vm_fault(map, va, VM_PROT_READ | VM_PROT_EXECUTE,
788 VM_FAULT_NORMAL);
789 if (map != kernel_map) {
790 PROC_LOCK(p);
791 p->p_lock--;
792 PROC_UNLOCK(p);
793 }
794
795 if (__predict_true(error == 0))
796 goto out;
797
798 if (error == ENOMEM) {
799 printf("VM: pid %d (%s), uid %d killed: "
800 "out of swap\n", td->td_proc->p_pid, td->td_name,
801 (td->td_proc->p_ucred) ?
802 td->td_proc->p_ucred->cr_uid : -1);
803 ksig.signb = SIGKILL;
804 } else {
805 ksig.signb = SIGSEGV;
806 }
807 ksig.code = 0;
808
809 do_trapsignal:
810 call_trapsignal(td, ksig.signb, ksig.code);
811
812 out:
813 userret(td, tf);
814
815 }
816
817 extern int badaddr_read_1(const uint8_t *, uint8_t *);
818 extern int badaddr_read_2(const uint16_t *, uint16_t *);
819 extern int badaddr_read_4(const uint32_t *, uint32_t *);
820 /*
821 * Tentatively read an 8, 16, or 32-bit value from 'addr'.
822 * If the read succeeds, the value is written to 'rptr' and zero is returned.
823 * Else, return EFAULT.
824 */
825 int
826 badaddr_read(void *addr, size_t size, void *rptr)
827 {
828 union {
829 uint8_t v1;
830 uint16_t v2;
831 uint32_t v4;
832 } u;
833 int rv;
834
835 cpu_drain_writebuf();
836
837 /* Read from the test address. */
838 switch (size) {
839 case sizeof(uint8_t):
840 rv = badaddr_read_1(addr, &u.v1);
841 if (rv == 0 && rptr)
842 *(uint8_t *) rptr = u.v1;
843 break;
844
845 case sizeof(uint16_t):
846 rv = badaddr_read_2(addr, &u.v2);
847 if (rv == 0 && rptr)
848 *(uint16_t *) rptr = u.v2;
849 break;
850
851 case sizeof(uint32_t):
852 rv = badaddr_read_4(addr, &u.v4);
853 if (rv == 0 && rptr)
854 *(uint32_t *) rptr = u.v4;
855 break;
856
857 default:
858 panic("badaddr: invalid size (%lu)", (u_long) size);
859 }
860
861 /* Return EFAULT if the address was invalid, else zero */
862 return (rv);
863 }
864
865 int
866 cpu_fetch_syscall_args(struct thread *td, struct syscall_args *sa)
867 {
868 struct proc *p;
869 register_t *ap;
870 int error;
871
872 #ifdef __ARM_EABI__
873 sa->code = td->td_frame->tf_r7;
874 #else
875 sa->code = sa->insn & 0x000fffff;
876 #endif
877 ap = &td->td_frame->tf_r0;
878 if (sa->code == SYS_syscall) {
879 sa->code = *ap++;
880 sa->nap--;
881 } else if (sa->code == SYS___syscall) {
882 sa->code = ap[_QUAD_LOWWORD];
883 sa->nap -= 2;
884 ap += 2;
885 }
886 p = td->td_proc;
887 if (p->p_sysent->sv_mask)
888 sa->code &= p->p_sysent->sv_mask;
889 if (sa->code >= p->p_sysent->sv_size)
890 sa->callp = &p->p_sysent->sv_table[0];
891 else
892 sa->callp = &p->p_sysent->sv_table[sa->code];
893 sa->narg = sa->callp->sy_narg;
894 error = 0;
895 memcpy(sa->args, ap, sa->nap * sizeof(register_t));
896 if (sa->narg > sa->nap) {
897 error = copyin((void *)td->td_frame->tf_usr_sp, sa->args +
898 sa->nap, (sa->narg - sa->nap) * sizeof(register_t));
899 }
900 if (error == 0) {
901 td->td_retval[0] = 0;
902 td->td_retval[1] = 0;
903 }
904 return (error);
905 }
906
907 #include "../../kern/subr_syscall.c"
908
909 static void
910 syscall(struct thread *td, trapframe_t *frame)
911 {
912 struct syscall_args sa;
913 int error;
914
915 #ifndef __ARM_EABI__
916 sa.insn = *(uint32_t *)(frame->tf_pc - INSN_SIZE);
917 switch (sa.insn & SWI_OS_MASK) {
918 case 0: /* XXX: we need our own one. */
919 break;
920 default:
921 call_trapsignal(td, SIGILL, 0);
922 userret(td, frame);
923 return;
924 }
925 #endif
926 sa.nap = 4;
927
928 error = syscallenter(td, &sa);
929 KASSERT(error != 0 || td->td_ar == NULL,
930 ("returning from syscall with td_ar set!"));
931 syscallret(td, error, &sa);
932 }
933
934 void
935 swi_handler(trapframe_t *frame)
936 {
937 struct thread *td = curthread;
938
939 td->td_frame = frame;
940
941 td->td_pticks = 0;
942 /*
943 * Make sure the program counter is correctly aligned so we
944 * don't take an alignment fault trying to read the opcode.
945 */
946 if (__predict_false(((frame->tf_pc - INSN_SIZE) & 3) != 0)) {
947 call_trapsignal(td, SIGILL, 0);
948 userret(td, frame);
949 return;
950 }
951 /*
952 * Enable interrupts if they were enabled before the exception.
953 * Since all syscalls *should* come from user mode it will always
954 * be safe to enable them, but check anyway.
955 */
956 if (td->td_md.md_spinlock_count == 0) {
957 if (__predict_true(frame->tf_spsr & I32_bit) == 0)
958 enable_interrupts(I32_bit);
959 if (__predict_true(frame->tf_spsr & F32_bit) == 0)
960 enable_interrupts(F32_bit);
961 }
962
963 syscall(td, frame);
964 }
965
Cache object: bdecbbab2c0eab11fe90df9553025cee
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