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/8.1/sys/arm/arm/trap.c 200443 2009-12-12 20:06:25Z kib $");
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 extern char *syscallnames[];
134
135 #ifdef DEBUG
136 int last_fault_code; /* For the benefit of pmap_fault_fixup() */
137 #endif
138
139 #if defined(CPU_ARM7TDMI)
140 /* These CPUs may need data/prefetch abort fixups */
141 #define CPU_ABORT_FIXUP_REQUIRED
142 #endif
143
144 struct ksig {
145 int signb;
146 u_long code;
147 };
148 struct data_abort {
149 int (*func)(trapframe_t *, u_int, u_int, struct thread *, struct ksig *);
150 const char *desc;
151 };
152
153 static int dab_fatal(trapframe_t *, u_int, u_int, struct thread *, struct ksig *);
154 static int dab_align(trapframe_t *, u_int, u_int, struct thread *, struct ksig *);
155 static int dab_buserr(trapframe_t *, u_int, u_int, struct thread *, struct ksig *);
156
157 static const struct data_abort data_aborts[] = {
158 {dab_fatal, "Vector Exception"},
159 {dab_align, "Alignment Fault 1"},
160 {dab_fatal, "Terminal Exception"},
161 {dab_align, "Alignment Fault 3"},
162 {dab_buserr, "External Linefetch Abort (S)"},
163 {NULL, "Translation Fault (S)"},
164 {dab_buserr, "External Linefetch Abort (P)"},
165 {NULL, "Translation Fault (P)"},
166 {dab_buserr, "External Non-Linefetch Abort (S)"},
167 {NULL, "Domain Fault (S)"},
168 {dab_buserr, "External Non-Linefetch Abort (P)"},
169 {NULL, "Domain Fault (P)"},
170 {dab_buserr, "External Translation Abort (L1)"},
171 {NULL, "Permission Fault (S)"},
172 {dab_buserr, "External Translation Abort (L2)"},
173 {NULL, "Permission Fault (P)"}
174 };
175
176 /* Determine if a fault came from user mode */
177 #define TRAP_USERMODE(tf) ((tf->tf_spsr & PSR_MODE) == PSR_USR32_MODE)
178
179 /* Determine if 'x' is a permission fault */
180 #define IS_PERMISSION_FAULT(x) \
181 (((1 << ((x) & FAULT_TYPE_MASK)) & \
182 ((1 << FAULT_PERM_P) | (1 << FAULT_PERM_S))) != 0)
183
184 static __inline void
185 call_trapsignal(struct thread *td, int sig, u_long code)
186 {
187 ksiginfo_t ksi;
188
189 ksiginfo_init_trap(&ksi);
190 ksi.ksi_signo = sig;
191 ksi.ksi_code = (int)code;
192 trapsignal(td, &ksi);
193 }
194
195 static __inline int
196 data_abort_fixup(trapframe_t *tf, u_int fsr, u_int far, struct thread *td, struct ksig *ksig)
197 {
198 #ifdef CPU_ABORT_FIXUP_REQUIRED
199 int error;
200
201 /* Call the cpu specific data abort fixup routine */
202 error = cpu_dataabt_fixup(tf);
203 if (__predict_true(error != ABORT_FIXUP_FAILED))
204 return (error);
205
206 /*
207 * Oops, couldn't fix up the instruction
208 */
209 printf("data_abort_fixup: fixup for %s mode data abort failed.\n",
210 TRAP_USERMODE(tf) ? "user" : "kernel");
211 printf("pc = 0x%08x, opcode 0x%08x, insn = ", tf->tf_pc,
212 *((u_int *)tf->tf_pc));
213 disassemble(tf->tf_pc);
214
215 /* Die now if this happened in kernel mode */
216 if (!TRAP_USERMODE(tf))
217 dab_fatal(tf, fsr, far, td, NULL, ksig);
218
219 return (error);
220 #else
221 return (ABORT_FIXUP_OK);
222 #endif /* CPU_ABORT_FIXUP_REQUIRED */
223 }
224
225 void
226 data_abort_handler(trapframe_t *tf)
227 {
228 struct vm_map *map;
229 struct pcb *pcb;
230 struct thread *td;
231 u_int user, far, fsr;
232 vm_prot_t ftype;
233 void *onfault;
234 vm_offset_t va;
235 int error = 0;
236 struct ksig ksig;
237 struct proc *p;
238
239
240 /* Grab FAR/FSR before enabling interrupts */
241 far = cpu_faultaddress();
242 fsr = cpu_faultstatus();
243 #if 0
244 printf("data abort: %p (from %p %p)\n", (void*)far, (void*)tf->tf_pc,
245 (void*)tf->tf_svc_lr);
246 #endif
247
248 /* Update vmmeter statistics */
249 #if 0
250 vmexp.traps++;
251 #endif
252
253 td = curthread;
254 p = td->td_proc;
255
256 PCPU_INC(cnt.v_trap);
257 /* Data abort came from user mode? */
258 user = TRAP_USERMODE(tf);
259
260 if (user) {
261 td->td_pticks = 0;
262 td->td_frame = tf;
263 if (td->td_ucred != td->td_proc->p_ucred)
264 cred_update_thread(td);
265
266 }
267 /* Grab the current pcb */
268 pcb = td->td_pcb;
269 /* Re-enable interrupts if they were enabled previously */
270 if (td->td_md.md_spinlock_count == 0) {
271 if (__predict_true(tf->tf_spsr & I32_bit) == 0)
272 enable_interrupts(I32_bit);
273 if (__predict_true(tf->tf_spsr & F32_bit) == 0)
274 enable_interrupts(F32_bit);
275 }
276
277
278 /* Invoke the appropriate handler, if necessary */
279 if (__predict_false(data_aborts[fsr & FAULT_TYPE_MASK].func != NULL)) {
280 if ((data_aborts[fsr & FAULT_TYPE_MASK].func)(tf, fsr, far,
281 td, &ksig)) {
282 goto do_trapsignal;
283 }
284 goto out;
285 }
286
287 /*
288 * At this point, we're dealing with one of the following data aborts:
289 *
290 * FAULT_TRANS_S - Translation -- Section
291 * FAULT_TRANS_P - Translation -- Page
292 * FAULT_DOMAIN_S - Domain -- Section
293 * FAULT_DOMAIN_P - Domain -- Page
294 * FAULT_PERM_S - Permission -- Section
295 * FAULT_PERM_P - Permission -- Page
296 *
297 * These are the main virtual memory-related faults signalled by
298 * the MMU.
299 */
300
301 /* fusubailout is used by [fs]uswintr to avoid page faulting */
302 if (__predict_false(pcb->pcb_onfault == fusubailout)) {
303 tf->tf_r0 = EFAULT;
304 tf->tf_pc = (register_t)(intptr_t) pcb->pcb_onfault;
305 return;
306 }
307
308 /*
309 * Make sure the Program Counter is sane. We could fall foul of
310 * someone executing Thumb code, in which case the PC might not
311 * be word-aligned. This would cause a kernel alignment fault
312 * further down if we have to decode the current instruction.
313 * XXX: It would be nice to be able to support Thumb at some point.
314 */
315 if (__predict_false((tf->tf_pc & 3) != 0)) {
316 if (user) {
317 /*
318 * Give the user an illegal instruction signal.
319 */
320 /* Deliver a SIGILL to the process */
321 ksig.signb = SIGILL;
322 ksig.code = 0;
323 goto do_trapsignal;
324 }
325
326 /*
327 * The kernel never executes Thumb code.
328 */
329 printf("\ndata_abort_fault: Misaligned Kernel-mode "
330 "Program Counter\n");
331 dab_fatal(tf, fsr, far, td, &ksig);
332 }
333
334 /* See if the cpu state needs to be fixed up */
335 switch (data_abort_fixup(tf, fsr, far, td, &ksig)) {
336 case ABORT_FIXUP_RETURN:
337 return;
338 case ABORT_FIXUP_FAILED:
339 /* Deliver a SIGILL to the process */
340 ksig.signb = SIGILL;
341 ksig.code = 0;
342 goto do_trapsignal;
343 default:
344 break;
345 }
346
347 va = trunc_page((vm_offset_t)far);
348
349 /*
350 * It is only a kernel address space fault iff:
351 * 1. user == 0 and
352 * 2. pcb_onfault not set or
353 * 3. pcb_onfault set and not LDRT/LDRBT/STRT/STRBT instruction.
354 */
355 if (user == 0 && (va >= VM_MIN_KERNEL_ADDRESS ||
356 (va < VM_MIN_ADDRESS && vector_page == ARM_VECTORS_LOW)) &&
357 __predict_true((pcb->pcb_onfault == NULL ||
358 (ReadWord(tf->tf_pc) & 0x05200000) != 0x04200000))) {
359 map = kernel_map;
360
361 /* Was the fault due to the FPE/IPKDB ? */
362 if (__predict_false((tf->tf_spsr & PSR_MODE)==PSR_UND32_MODE)) {
363
364 /*
365 * Force exit via userret()
366 * This is necessary as the FPE is an extension to
367 * userland that actually runs in a priveledged mode
368 * but uses USR mode permissions for its accesses.
369 */
370 user = 1;
371 ksig.signb = SIGSEGV;
372 ksig.code = 0;
373 goto do_trapsignal;
374 }
375 } else {
376 map = &td->td_proc->p_vmspace->vm_map;
377 }
378
379 /*
380 * We need to know whether the page should be mapped
381 * as R or R/W. The MMU does not give us the info as
382 * to whether the fault was caused by a read or a write.
383 *
384 * However, we know that a permission fault can only be
385 * the result of a write to a read-only location, so
386 * we can deal with those quickly.
387 *
388 * Otherwise we need to disassemble the instruction
389 * responsible to determine if it was a write.
390 */
391 if (IS_PERMISSION_FAULT(fsr)) {
392 ftype = VM_PROT_WRITE;
393 } else {
394 u_int insn = ReadWord(tf->tf_pc);
395
396 if (((insn & 0x0c100000) == 0x04000000) || /* STR/STRB */
397 ((insn & 0x0e1000b0) == 0x000000b0) || /* STRH/STRD */
398 ((insn & 0x0a100000) == 0x08000000)) /* STM/CDT */
399 {
400 ftype = VM_PROT_WRITE;
401 }
402 else
403 if ((insn & 0x0fb00ff0) == 0x01000090) /* SWP */
404 ftype = VM_PROT_READ | VM_PROT_WRITE;
405 else
406 ftype = VM_PROT_READ;
407 }
408
409 /*
410 * See if the fault is as a result of ref/mod emulation,
411 * or domain mismatch.
412 */
413 #ifdef DEBUG
414 last_fault_code = fsr;
415 #endif
416 if (pmap_fault_fixup(vmspace_pmap(td->td_proc->p_vmspace), va, ftype,
417 user)) {
418 goto out;
419 }
420
421 onfault = pcb->pcb_onfault;
422 pcb->pcb_onfault = NULL;
423 if (map != kernel_map) {
424 PROC_LOCK(p);
425 p->p_lock++;
426 PROC_UNLOCK(p);
427 }
428 error = vm_fault(map, va, ftype, (ftype & VM_PROT_WRITE) ?
429 VM_FAULT_DIRTY : VM_FAULT_NORMAL);
430 pcb->pcb_onfault = onfault;
431
432 if (map != kernel_map) {
433 PROC_LOCK(p);
434 p->p_lock--;
435 PROC_UNLOCK(p);
436 }
437 if (__predict_true(error == 0))
438 goto out;
439 if (user == 0) {
440 if (pcb->pcb_onfault) {
441 tf->tf_r0 = error;
442 tf->tf_pc = (register_t)(intptr_t) pcb->pcb_onfault;
443 return;
444 }
445
446 printf("\nvm_fault(%p, %x, %x, 0) -> %x\n", map, va, ftype,
447 error);
448 dab_fatal(tf, fsr, far, td, &ksig);
449 }
450
451
452 if (error == ENOMEM) {
453 printf("VM: pid %d (%s), uid %d killed: "
454 "out of swap\n", td->td_proc->p_pid, td->td_name,
455 (td->td_proc->p_ucred) ?
456 td->td_proc->p_ucred->cr_uid : -1);
457 ksig.signb = SIGKILL;
458 } else {
459 ksig.signb = SIGSEGV;
460 }
461 ksig.code = 0;
462 do_trapsignal:
463 call_trapsignal(td, ksig.signb, ksig.code);
464 out:
465 /* If returning to user mode, make sure to invoke userret() */
466 if (user)
467 userret(td, tf);
468 }
469
470 /*
471 * dab_fatal() handles the following data aborts:
472 *
473 * FAULT_WRTBUF_0 - Vector Exception
474 * FAULT_WRTBUF_1 - Terminal Exception
475 *
476 * We should never see these on a properly functioning system.
477 *
478 * This function is also called by the other handlers if they
479 * detect a fatal problem.
480 *
481 * Note: If 'l' is NULL, we assume we're dealing with a prefetch abort.
482 */
483 static int
484 dab_fatal(trapframe_t *tf, u_int fsr, u_int far, struct thread *td, struct ksig *ksig)
485 {
486 const char *mode;
487
488 mode = TRAP_USERMODE(tf) ? "user" : "kernel";
489
490 disable_interrupts(I32_bit|F32_bit);
491 if (td != NULL) {
492 printf("Fatal %s mode data abort: '%s'\n", mode,
493 data_aborts[fsr & FAULT_TYPE_MASK].desc);
494 printf("trapframe: %p\nFSR=%08x, FAR=", tf, fsr);
495 if ((fsr & FAULT_IMPRECISE) == 0)
496 printf("%08x, ", far);
497 else
498 printf("Invalid, ");
499 printf("spsr=%08x\n", tf->tf_spsr);
500 } else {
501 printf("Fatal %s mode prefetch abort at 0x%08x\n",
502 mode, tf->tf_pc);
503 printf("trapframe: %p, spsr=%08x\n", tf, tf->tf_spsr);
504 }
505
506 printf("r0 =%08x, r1 =%08x, r2 =%08x, r3 =%08x\n",
507 tf->tf_r0, tf->tf_r1, tf->tf_r2, tf->tf_r3);
508 printf("r4 =%08x, r5 =%08x, r6 =%08x, r7 =%08x\n",
509 tf->tf_r4, tf->tf_r5, tf->tf_r6, tf->tf_r7);
510 printf("r8 =%08x, r9 =%08x, r10=%08x, r11=%08x\n",
511 tf->tf_r8, tf->tf_r9, tf->tf_r10, tf->tf_r11);
512 printf("r12=%08x, ", tf->tf_r12);
513
514 if (TRAP_USERMODE(tf))
515 printf("usp=%08x, ulr=%08x",
516 tf->tf_usr_sp, tf->tf_usr_lr);
517 else
518 printf("ssp=%08x, slr=%08x",
519 tf->tf_svc_sp, tf->tf_svc_lr);
520 printf(", pc =%08x\n\n", tf->tf_pc);
521
522 #ifdef KDB
523 if (debugger_on_panic || kdb_active)
524 kdb_trap(fsr, 0, tf);
525 #endif
526 panic("Fatal abort");
527 /*NOTREACHED*/
528 }
529
530 /*
531 * dab_align() handles the following data aborts:
532 *
533 * FAULT_ALIGN_0 - Alignment fault
534 * FAULT_ALIGN_1 - Alignment fault
535 *
536 * These faults are fatal if they happen in kernel mode. Otherwise, we
537 * deliver a bus error to the process.
538 */
539 static int
540 dab_align(trapframe_t *tf, u_int fsr, u_int far, struct thread *td, struct ksig *ksig)
541 {
542
543 /* Alignment faults are always fatal if they occur in kernel mode */
544 if (!TRAP_USERMODE(tf)) {
545 if (!td || !td->td_pcb->pcb_onfault)
546 dab_fatal(tf, fsr, far, td, ksig);
547 tf->tf_r0 = EFAULT;
548 tf->tf_pc = (int)td->td_pcb->pcb_onfault;
549 return (0);
550 }
551
552 /* pcb_onfault *must* be NULL at this point */
553
554 /* See if the cpu state needs to be fixed up */
555 (void) data_abort_fixup(tf, fsr, far, td, ksig);
556
557 /* Deliver a bus error signal to the process */
558 ksig->code = 0;
559 ksig->signb = SIGBUS;
560 td->td_frame = tf;
561
562 return (1);
563 }
564
565 /*
566 * dab_buserr() handles the following data aborts:
567 *
568 * FAULT_BUSERR_0 - External Abort on Linefetch -- Section
569 * FAULT_BUSERR_1 - External Abort on Linefetch -- Page
570 * FAULT_BUSERR_2 - External Abort on Non-linefetch -- Section
571 * FAULT_BUSERR_3 - External Abort on Non-linefetch -- Page
572 * FAULT_BUSTRNL1 - External abort on Translation -- Level 1
573 * FAULT_BUSTRNL2 - External abort on Translation -- Level 2
574 *
575 * If pcb_onfault is set, flag the fault and return to the handler.
576 * If the fault occurred in user mode, give the process a SIGBUS.
577 *
578 * Note: On XScale, FAULT_BUSERR_0, FAULT_BUSERR_1, and FAULT_BUSERR_2
579 * can be flagged as imprecise in the FSR. This causes a real headache
580 * since some of the machine state is lost. In this case, tf->tf_pc
581 * may not actually point to the offending instruction. In fact, if
582 * we've taken a double abort fault, it generally points somewhere near
583 * the top of "data_abort_entry" in exception.S.
584 *
585 * In all other cases, these data aborts are considered fatal.
586 */
587 static int
588 dab_buserr(trapframe_t *tf, u_int fsr, u_int far, struct thread *td, struct ksig *ksig)
589 {
590 struct pcb *pcb = td->td_pcb;
591
592 #ifdef __XSCALE__
593 if ((fsr & FAULT_IMPRECISE) != 0 &&
594 (tf->tf_spsr & PSR_MODE) == PSR_ABT32_MODE) {
595 /*
596 * Oops, an imprecise, double abort fault. We've lost the
597 * r14_abt/spsr_abt values corresponding to the original
598 * abort, and the spsr saved in the trapframe indicates
599 * ABT mode.
600 */
601 tf->tf_spsr &= ~PSR_MODE;
602
603 /*
604 * We use a simple heuristic to determine if the double abort
605 * happened as a result of a kernel or user mode access.
606 * If the current trapframe is at the top of the kernel stack,
607 * the fault _must_ have come from user mode.
608 */
609 if (tf != ((trapframe_t *)pcb->un_32.pcb32_sp) - 1) {
610 /*
611 * Kernel mode. We're either about to die a
612 * spectacular death, or pcb_onfault will come
613 * to our rescue. Either way, the current value
614 * of tf->tf_pc is irrelevant.
615 */
616 tf->tf_spsr |= PSR_SVC32_MODE;
617 if (pcb->pcb_onfault == NULL)
618 printf("\nKernel mode double abort!\n");
619 } else {
620 /*
621 * User mode. We've lost the program counter at the
622 * time of the fault (not that it was accurate anyway;
623 * it's not called an imprecise fault for nothing).
624 * About all we can do is copy r14_usr to tf_pc and
625 * hope for the best. The process is about to get a
626 * SIGBUS, so it's probably history anyway.
627 */
628 tf->tf_spsr |= PSR_USR32_MODE;
629 tf->tf_pc = tf->tf_usr_lr;
630 }
631 }
632
633 /* FAR is invalid for imprecise exceptions */
634 if ((fsr & FAULT_IMPRECISE) != 0)
635 far = 0;
636 #endif /* __XSCALE__ */
637
638 if (pcb->pcb_onfault) {
639 tf->tf_r0 = EFAULT;
640 tf->tf_pc = (register_t)(intptr_t) pcb->pcb_onfault;
641 return (0);
642 }
643
644 /* See if the cpu state needs to be fixed up */
645 (void) data_abort_fixup(tf, fsr, far, td, ksig);
646
647 /*
648 * At this point, if the fault happened in kernel mode, we're toast
649 */
650 if (!TRAP_USERMODE(tf))
651 dab_fatal(tf, fsr, far, td, ksig);
652
653 /* Deliver a bus error signal to the process */
654 ksig->signb = SIGBUS;
655 ksig->code = 0;
656 td->td_frame = tf;
657
658 return (1);
659 }
660
661 static __inline int
662 prefetch_abort_fixup(trapframe_t *tf, struct ksig *ksig)
663 {
664 #ifdef CPU_ABORT_FIXUP_REQUIRED
665 int error;
666
667 /* Call the cpu specific prefetch abort fixup routine */
668 error = cpu_prefetchabt_fixup(tf);
669 if (__predict_true(error != ABORT_FIXUP_FAILED))
670 return (error);
671
672 /*
673 * Oops, couldn't fix up the instruction
674 */
675 printf(
676 "prefetch_abort_fixup: fixup for %s mode prefetch abort failed.\n",
677 TRAP_USERMODE(tf) ? "user" : "kernel");
678 printf("pc = 0x%08x, opcode 0x%08x, insn = ", tf->tf_pc,
679 *((u_int *)tf->tf_pc));
680 disassemble(tf->tf_pc);
681
682 /* Die now if this happened in kernel mode */
683 if (!TRAP_USERMODE(tf))
684 dab_fatal(tf, 0, tf->tf_pc, NULL, ksig);
685
686 return (error);
687 #else
688 return (ABORT_FIXUP_OK);
689 #endif /* CPU_ABORT_FIXUP_REQUIRED */
690 }
691
692 /*
693 * void prefetch_abort_handler(trapframe_t *tf)
694 *
695 * Abort handler called when instruction execution occurs at
696 * a non existent or restricted (access permissions) memory page.
697 * If the address is invalid and we were in SVC mode then panic as
698 * the kernel should never prefetch abort.
699 * If the address is invalid and the page is mapped then the user process
700 * does no have read permission so send it a signal.
701 * Otherwise fault the page in and try again.
702 */
703 void
704 prefetch_abort_handler(trapframe_t *tf)
705 {
706 struct thread *td;
707 struct proc * p;
708 struct vm_map *map;
709 vm_offset_t fault_pc, va;
710 int error = 0;
711 struct ksig ksig;
712
713
714 #if 0
715 /* Update vmmeter statistics */
716 uvmexp.traps++;
717 #endif
718 #if 0
719 printf("prefetch abort handler: %p %p\n", (void*)tf->tf_pc,
720 (void*)tf->tf_usr_lr);
721 #endif
722
723 td = curthread;
724 p = td->td_proc;
725 PCPU_INC(cnt.v_trap);
726
727 if (TRAP_USERMODE(tf)) {
728 td->td_frame = tf;
729 if (td->td_ucred != td->td_proc->p_ucred)
730 cred_update_thread(td);
731 }
732 fault_pc = tf->tf_pc;
733 if (td->td_md.md_spinlock_count == 0) {
734 if (__predict_true(tf->tf_spsr & I32_bit) == 0)
735 enable_interrupts(I32_bit);
736 if (__predict_true(tf->tf_spsr & F32_bit) == 0)
737 enable_interrupts(F32_bit);
738 }
739
740
741
742 /* See if the cpu state needs to be fixed up */
743 switch (prefetch_abort_fixup(tf, &ksig)) {
744 case ABORT_FIXUP_RETURN:
745 return;
746 case ABORT_FIXUP_FAILED:
747 /* Deliver a SIGILL to the process */
748 ksig.signb = SIGILL;
749 ksig.code = 0;
750 td->td_frame = tf;
751 goto do_trapsignal;
752 default:
753 break;
754 }
755
756 /* Prefetch aborts cannot happen in kernel mode */
757 if (__predict_false(!TRAP_USERMODE(tf)))
758 dab_fatal(tf, 0, tf->tf_pc, NULL, &ksig);
759 td->td_pticks = 0;
760
761
762 /* Ok validate the address, can only execute in USER space */
763 if (__predict_false(fault_pc >= VM_MAXUSER_ADDRESS ||
764 (fault_pc < VM_MIN_ADDRESS && vector_page == ARM_VECTORS_LOW))) {
765 ksig.signb = SIGSEGV;
766 ksig.code = 0;
767 goto do_trapsignal;
768 }
769
770 map = &td->td_proc->p_vmspace->vm_map;
771 va = trunc_page(fault_pc);
772
773 /*
774 * See if the pmap can handle this fault on its own...
775 */
776 #ifdef DEBUG
777 last_fault_code = -1;
778 #endif
779 if (pmap_fault_fixup(map->pmap, va, VM_PROT_READ, 1))
780 goto out;
781
782 if (map != kernel_map) {
783 PROC_LOCK(p);
784 p->p_lock++;
785 PROC_UNLOCK(p);
786 }
787
788 error = vm_fault(map, va, VM_PROT_READ | VM_PROT_EXECUTE,
789 VM_FAULT_NORMAL);
790 if (map != kernel_map) {
791 PROC_LOCK(p);
792 p->p_lock--;
793 PROC_UNLOCK(p);
794 }
795
796 if (__predict_true(error == 0))
797 goto out;
798
799 if (error == ENOMEM) {
800 printf("VM: pid %d (%s), uid %d killed: "
801 "out of swap\n", td->td_proc->p_pid, td->td_name,
802 (td->td_proc->p_ucred) ?
803 td->td_proc->p_ucred->cr_uid : -1);
804 ksig.signb = SIGKILL;
805 } else {
806 ksig.signb = SIGSEGV;
807 }
808 ksig.code = 0;
809
810 do_trapsignal:
811 call_trapsignal(td, ksig.signb, ksig.code);
812
813 out:
814 userret(td, tf);
815
816 }
817
818 extern int badaddr_read_1(const uint8_t *, uint8_t *);
819 extern int badaddr_read_2(const uint16_t *, uint16_t *);
820 extern int badaddr_read_4(const uint32_t *, uint32_t *);
821 /*
822 * Tentatively read an 8, 16, or 32-bit value from 'addr'.
823 * If the read succeeds, the value is written to 'rptr' and zero is returned.
824 * Else, return EFAULT.
825 */
826 int
827 badaddr_read(void *addr, size_t size, void *rptr)
828 {
829 union {
830 uint8_t v1;
831 uint16_t v2;
832 uint32_t v4;
833 } u;
834 int rv;
835
836 cpu_drain_writebuf();
837
838 /* Read from the test address. */
839 switch (size) {
840 case sizeof(uint8_t):
841 rv = badaddr_read_1(addr, &u.v1);
842 if (rv == 0 && rptr)
843 *(uint8_t *) rptr = u.v1;
844 break;
845
846 case sizeof(uint16_t):
847 rv = badaddr_read_2(addr, &u.v2);
848 if (rv == 0 && rptr)
849 *(uint16_t *) rptr = u.v2;
850 break;
851
852 case sizeof(uint32_t):
853 rv = badaddr_read_4(addr, &u.v4);
854 if (rv == 0 && rptr)
855 *(uint32_t *) rptr = u.v4;
856 break;
857
858 default:
859 panic("badaddr: invalid size (%lu)", (u_long) size);
860 }
861
862 /* Return EFAULT if the address was invalid, else zero */
863 return (rv);
864 }
865
866 #define MAXARGS 8
867 static void
868 syscall(struct thread *td, trapframe_t *frame, u_int32_t insn)
869 {
870 struct proc *p = td->td_proc;
871 int code, error;
872 u_int nap, nargs;
873 register_t *ap, *args, copyargs[MAXARGS];
874 struct sysent *callp;
875
876 PCPU_INC(cnt.v_syscall);
877 td->td_pticks = 0;
878 if (td->td_ucred != td->td_proc->p_ucred)
879 cred_update_thread(td);
880 switch (insn & SWI_OS_MASK) {
881 case 0: /* XXX: we need our own one. */
882 nap = 4;
883 break;
884 default:
885 call_trapsignal(td, SIGILL, 0);
886 userret(td, frame);
887 return;
888 }
889 code = insn & 0x000fffff;
890 td->td_pticks = 0;
891 ap = &frame->tf_r0;
892 if (code == SYS_syscall) {
893 code = *ap++;
894
895 nap--;
896 } else if (code == SYS___syscall) {
897 code = ap[_QUAD_LOWWORD];
898 nap -= 2;
899 ap += 2;
900 }
901 if (p->p_sysent->sv_mask)
902 code &= p->p_sysent->sv_mask;
903 if (code >= p->p_sysent->sv_size)
904 callp = &p->p_sysent->sv_table[0];
905 else
906 callp = &p->p_sysent->sv_table[code];
907 nargs = callp->sy_narg;
908 memcpy(copyargs, ap, nap * sizeof(register_t));
909 if (nargs > nap) {
910 error = copyin((void *)frame->tf_usr_sp, copyargs + nap,
911 (nargs - nap) * sizeof(register_t));
912 if (error)
913 goto bad;
914 }
915 args = copyargs;
916 error = 0;
917 #ifdef KTRACE
918 if (KTRPOINT(td, KTR_SYSCALL))
919 ktrsyscall(code, nargs, args);
920 #endif
921
922 CTR4(KTR_SYSC, "syscall enter thread %p pid %d proc %s code %d", td,
923 td->td_proc->p_pid, td->td_name, code);
924 if (error == 0) {
925 td->td_retval[0] = 0;
926 td->td_retval[1] = 0;
927 STOPEVENT(p, S_SCE, callp->sy_narg);
928 PTRACESTOP_SC(p, td, S_PT_SCE);
929 AUDIT_SYSCALL_ENTER(code, td);
930 error = (*callp->sy_call)(td, args);
931 AUDIT_SYSCALL_EXIT(error, td);
932 KASSERT(td->td_ar == NULL,
933 ("returning from syscall with td_ar set!"));
934 }
935 bad:
936 cpu_set_syscall_retval(td, error);
937
938 WITNESS_WARN(WARN_PANIC, NULL, "System call %s returning",
939 (code >= 0 && code < SYS_MAXSYSCALL) ? syscallnames[code] : "???");
940 KASSERT(td->td_critnest == 0,
941 ("System call %s returning in a critical section",
942 (code >= 0 && code < SYS_MAXSYSCALL) ? syscallnames[code] : "???"));
943 KASSERT(td->td_locks == 0,
944 ("System call %s returning with %d locks held",
945 (code >= 0 && code < SYS_MAXSYSCALL) ? syscallnames[code] : "???",
946 td->td_locks));
947
948 userret(td, frame);
949 CTR4(KTR_SYSC, "syscall exit thread %p pid %d proc %s code %d", td,
950 td->td_proc->p_pid, td->td_name, code);
951
952 STOPEVENT(p, S_SCX, code);
953 PTRACESTOP_SC(p, td, S_PT_SCX);
954 #ifdef KTRACE
955 if (KTRPOINT(td, KTR_SYSRET))
956 ktrsysret(code, error, td->td_retval[0]);
957 #endif
958 }
959
960 void
961 swi_handler(trapframe_t *frame)
962 {
963 struct thread *td = curthread;
964 uint32_t insn;
965
966 td->td_frame = frame;
967
968 td->td_pticks = 0;
969 /*
970 * Make sure the program counter is correctly aligned so we
971 * don't take an alignment fault trying to read the opcode.
972 */
973 if (__predict_false(((frame->tf_pc - INSN_SIZE) & 3) != 0)) {
974 call_trapsignal(td, SIGILL, 0);
975 userret(td, frame);
976 return;
977 }
978 insn = *(u_int32_t *)(frame->tf_pc - INSN_SIZE);
979 /*
980 * Enable interrupts if they were enabled before the exception.
981 * Since all syscalls *should* come from user mode it will always
982 * be safe to enable them, but check anyway.
983 */
984 if (td->td_md.md_spinlock_count == 0) {
985 if (__predict_true(frame->tf_spsr & I32_bit) == 0)
986 enable_interrupts(I32_bit);
987 if (__predict_true(frame->tf_spsr & F32_bit) == 0)
988 enable_interrupts(F32_bit);
989 }
990
991 syscall(td, frame, insn);
992 }
993
Cache object: 3eaf33cdf4760de87d92717be073e27e
|