xref: /netbsd-src/sys/arch/arm/arm32/fault.c (revision 1ffa7b76c40339c17a0fb2a09fac93f287cfc046)
1 /*	$NetBSD: fault.c,v 1.29 2003/04/28 15:57:23 scw Exp $	*/
2 
3 /*
4  * Copyright 2003 Wasabi Systems, Inc.
5  * All rights reserved.
6  *
7  * Written by Steve C. Woodford for Wasabi Systems, Inc.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. All advertising materials mentioning features or use of this software
18  *    must display the following acknowledgement:
19  *      This product includes software developed for the NetBSD Project by
20  *      Wasabi Systems, Inc.
21  * 4. The name of Wasabi Systems, Inc. may not be used to endorse
22  *    or promote products derived from this software without specific prior
23  *    written permission.
24  *
25  * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
27  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
28  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL WASABI SYSTEMS, INC
29  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
30  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
31  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
32  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
33  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
34  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
35  * POSSIBILITY OF SUCH DAMAGE.
36  */
37 /*
38  * Copyright (c) 1994-1997 Mark Brinicombe.
39  * Copyright (c) 1994 Brini.
40  * All rights reserved.
41  *
42  * This code is derived from software written for Brini by Mark Brinicombe
43  *
44  * Redistribution and use in source and binary forms, with or without
45  * modification, are permitted provided that the following conditions
46  * are met:
47  * 1. Redistributions of source code must retain the above copyright
48  *    notice, this list of conditions and the following disclaimer.
49  * 2. Redistributions in binary form must reproduce the above copyright
50  *    notice, this list of conditions and the following disclaimer in the
51  *    documentation and/or other materials provided with the distribution.
52  * 3. All advertising materials mentioning features or use of this software
53  *    must display the following acknowledgement:
54  *	This product includes software developed by Brini.
55  * 4. The name of the company nor the name of the author may be used to
56  *    endorse or promote products derived from this software without specific
57  *    prior written permission.
58  *
59  * THIS SOFTWARE IS PROVIDED BY BRINI ``AS IS'' AND ANY EXPRESS OR IMPLIED
60  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
61  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
62  * IN NO EVENT SHALL BRINI OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
63  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
64  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
65  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
66  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
67  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
68  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
69  * SUCH DAMAGE.
70  *
71  * RiscBSD kernel project
72  *
73  * fault.c
74  *
75  * Fault handlers
76  *
77  * Created      : 28/11/94
78  */
79 
80 #include "opt_ddb.h"
81 #include "opt_kgdb.h"
82 #include "opt_pmap_debug.h"
83 
84 #include <sys/types.h>
85 __KERNEL_RCSID(0, "$NetBSD: fault.c,v 1.29 2003/04/28 15:57:23 scw Exp $");
86 
87 #include <sys/param.h>
88 #include <sys/systm.h>
89 #include <sys/proc.h>
90 #include <sys/user.h>
91 #include <sys/kernel.h>
92 
93 #include <uvm/uvm_extern.h>
94 
95 #include <arm/cpuconf.h>
96 
97 #include <machine/frame.h>
98 #include <arm/arm32/katelib.h>
99 #include <machine/cpu.h>
100 #include <machine/intr.h>
101 #if defined(DDB) || defined(KGDB)
102 #include <machine/db_machdep.h>
103 #ifdef KGDB
104 #include <sys/kgdb.h>
105 #endif
106 #if !defined(DDB)
107 #define kdb_trap	kgdb_trap
108 #endif
109 #endif
110 
111 #include <arch/arm/arm/disassem.h>
112 #include <arm/arm32/machdep.h>
113 
114 extern char fusubailout[];
115 
116 #ifdef DEBUG
117 int last_fault_code;	/* For the benefit of pmap_fault_fixup() */
118 #endif
119 
120 static void report_abort __P((const char *, u_int, u_int, u_int));
121 
122 /* Abort code */
123 
124 /* Define text descriptions of the different aborts */
125 
126 static const char *aborts[16] = {
127 	"Write buffer fault",
128 	"Alignment fault",
129 	"Write buffer fault",
130 	"Alignment fault",
131 	"Bus error (LF section)",
132 	"Translation fault (section)",
133 	"Bus error (page)",
134 	"Translation fault (page)",
135 	"Bus error (section)",
136 	"Domain error (section)",
137 	"Bus error (page)",
138 	"Domain error (page)",
139 	"Bus error trans (L1)",
140 	"Permission error (section)",
141 	"Bus error trans (L2)",
142 	"Permission error (page)"
143 };
144 
145 static void
146 report_abort(prefix, fault_status, fault_address, fault_pc)
147 	const char *prefix;
148 	u_int fault_status;
149 	u_int fault_address;
150 	u_int fault_pc;
151 {
152 #ifndef DEBUG
153 	if (prefix == NULL) {
154 #endif
155 		if (prefix)
156 			printf("%s ", prefix);
157 		printf("Data abort: '%s' status=%03x address=%08x PC=%08x\n",
158 		    aborts[fault_status & FAULT_TYPE_MASK],
159 		    fault_status & 0xfff, fault_address, fault_pc);
160 #ifndef DEBUG
161 	}
162 #endif
163 }
164 
165 static __volatile int data_abort_expected;
166 static __volatile int data_abort_received;
167 
168 int
169 badaddr_read(void *addr, size_t size, void *rptr)
170 {
171 	u_long rcpt;
172 	int rv;
173 
174 	/* Tell the Data Abort handler that we're expecting one. */
175 	data_abort_received = 0;
176 	data_abort_expected = 1;
177 
178 	cpu_drain_writebuf();
179 
180 	/* Read from the test address. */
181 	switch (size) {
182 	case sizeof(uint8_t):
183 		__asm __volatile("ldrb %0, [%1]"
184 			: "=r" (rcpt)
185 			: "r" (addr));
186 		break;
187 
188 	case sizeof(uint16_t):
189 		__asm __volatile("ldrh %0, [%1]"
190 			: "=r" (rcpt)
191 			: "r" (addr));
192 		break;
193 
194 	case sizeof(uint32_t):
195 		__asm __volatile("ldr %0, [%1]"
196 			: "=r" (rcpt)
197 			: "r" (addr));
198 		break;
199 
200 	default:
201 		data_abort_expected = 0;
202 		panic("badaddr: invalid size (%lu)", (u_long) size);
203 	}
204 
205 	/* Disallow further Data Aborts. */
206 	data_abort_expected = 0;
207 
208 	rv = data_abort_received;
209 	data_abort_received = 0;
210 
211 	/* Copy the data back if no fault occurred. */
212 	if (rptr != NULL && rv == 0) {
213 		switch (size) {
214 		case sizeof(uint8_t):
215 			*(uint8_t *) rptr = rcpt;
216 			break;
217 
218 		case sizeof(uint16_t):
219 			*(uint16_t *) rptr = rcpt;
220 			break;
221 
222 		case sizeof(uint32_t):
223 			*(uint32_t *) rptr = rcpt;
224 			break;
225 		}
226 	}
227 
228 	/* Return true if the address was invalid. */
229 	return (rv);
230 }
231 
232 /*
233  * void data_abort_handler(trapframe_t *frame)
234  *
235  * Abort handler called when read/write occurs at an address of
236  * a non existent or restricted (access permissions) memory page.
237  * We first need to identify the type of page fault.
238  */
239 
240 #define TRAP_CODE ((fault_status & 0x0f) | (fault_address & 0xfffffff0))
241 
242 /* Determine if we can recover from a fault */
243 #ifdef ARM32_PMAP_NEW
244 #define	IS_FATAL_FAULT(x)					\
245 	(((1 << (x)) &						\
246 	  ((1 << FAULT_WRTBUF_0) | (1 << FAULT_WRTBUF_1) |	\
247 	   (1 << FAULT_BUSERR_0) | (1 << FAULT_BUSERR_1) |	\
248 	   (1 << FAULT_BUSERR_2) | (1 << FAULT_BUSERR_3) |	\
249 	   (1 << FAULT_BUSTRNL1) | (1 << FAULT_BUSTRNL2) |	\
250 	   (1 << FAULT_ALIGN_0)  | (1 << FAULT_ALIGN_1))) != 0)
251 #else
252 #define	IS_FATAL_FAULT(x)					\
253 	(((1 << (x)) &						\
254 	  ((1 << FAULT_WRTBUF_0) | (1 << FAULT_WRTBUF_1) |	\
255 	   (1 << FAULT_BUSERR_0) | (1 << FAULT_BUSERR_1) |	\
256 	   (1 << FAULT_BUSERR_2) | (1 << FAULT_BUSERR_3) |	\
257 	   (1 << FAULT_BUSTRNL1) | (1 << FAULT_BUSTRNL2) |	\
258 	   (1 << FAULT_DOMAIN_S) | (1 << FAULT_DOMAIN_P) |	\
259 	   (1 << FAULT_ALIGN_0)  | (1 << FAULT_ALIGN_1))) != 0)
260 #endif
261 
262 void
263 data_abort_handler(frame)
264 	trapframe_t *frame;
265 {
266 	struct lwp *l;
267 	struct proc *p;
268 	struct pcb *pcb;
269 	u_int fault_address;
270 	u_int fault_status;
271 	u_int fault_pc;
272 	u_int fault_instruction;
273 	int fault_code, fatal_fault;
274 	int user;
275 	int error;
276 	int rv;
277 	void *onfault;
278 	vaddr_t va;
279 	struct vmspace *vm;
280 	struct vm_map *map;
281 	vm_prot_t ftype;
282 	extern struct vm_map *kernel_map;
283 
284 	/*
285 	 * If we were expecting a Data Abort, signal that we got
286 	 * one, adjust the PC to skip the faulting insn, and
287 	 * return.
288 	 */
289 	if (data_abort_expected) {
290 		data_abort_received = 1;
291 		frame->tf_pc += INSN_SIZE;
292 		return;
293 	}
294 
295 	/*
296 	 * Must get fault address and status from the CPU before
297 	 * re-enabling interrupts.  (Interrupt handlers may take
298 	 * R/M emulation faults.)
299 	 */
300 	fault_address = cpu_faultaddress();
301 	fault_status = cpu_faultstatus();
302 	fault_pc = frame->tf_pc;
303 
304 	/*
305 	 * Enable IRQ's (disabled by CPU on abort) if trapframe
306 	 * shows they were enabled.
307 	 */
308 	if (!(frame->tf_spsr & I32_bit))
309 		enable_interrupts(I32_bit);
310 
311 #ifdef DEBUG
312 	if ((GetCPSR() & PSR_MODE) != PSR_SVC32_MODE)
313 		panic("data_abort_handler: not in SVC32 mode");
314 #endif
315 
316 	/* Update vmmeter statistics */
317 	uvmexp.traps++;
318 
319 	/* Extract the fault code from the fault status */
320 	fault_code = fault_status & FAULT_TYPE_MASK;
321 	fatal_fault = IS_FATAL_FAULT(fault_code);
322 
323 	/* Get the current lwp structure or lwp0 if there is none */
324 	l = curlwp == NULL ? &lwp0 : curlwp;
325 	p = l->l_proc;
326 
327 	/*
328 	 * can't use curpcb, as it might be NULL; and we have p in
329 	 * a register anyway
330 	 */
331 	pcb = &l->l_addr->u_pcb;
332 
333 	/* fusubailout is used by [fs]uswintr to avoid page faulting */
334 	if (pcb->pcb_onfault &&
335 	    (fatal_fault || pcb->pcb_onfault == fusubailout)) {
336 
337 		frame->tf_r0 = EFAULT;
338 copyfault:
339 #ifdef DEBUG
340 		printf("Using pcb_onfault=%p addr=%08x st=%08x l=%p\n",
341 		    pcb->pcb_onfault, fault_address, fault_status, l);
342 #endif
343 		frame->tf_pc = (u_int)pcb->pcb_onfault;
344 		if ((frame->tf_spsr & PSR_MODE) == PSR_USR32_MODE)
345 			panic("Yikes pcb_onfault=%p during USR mode fault",
346 			    pcb->pcb_onfault);
347 		return;
348 	}
349 
350 	/* More debug stuff */
351 
352 	fault_instruction = ReadWord(fault_pc);
353 
354 #ifdef PMAP_DEBUG
355 	if (pmap_debug_level >= 0) {
356 		report_abort(NULL, fault_status, fault_address, fault_pc);
357 		printf("Instruction @V%08x = %08x\n",
358 		    fault_pc, fault_instruction);
359 	}
360 #endif
361 
362 	/* Call the cpu specific abort fixup routine */
363 	error = cpu_dataabt_fixup(frame);
364 	if (error == ABORT_FIXUP_RETURN)
365 		return;
366 	if (error == ABORT_FIXUP_FAILED) {
367 		printf("pc = 0x%08x, opcode 0x%08x, insn = ", fault_pc, *((u_int *)fault_pc));
368 		disassemble(fault_pc);
369 		printf("data abort handler: fixup failed for this instruction\n");
370 	}
371 
372 #ifdef PMAP_DEBUG
373 	if (pmap_debug_level >= 0)
374 		printf("fault in process %p\n", p);
375 #endif
376 
377 #ifdef DEBUG
378 	/* Is this needed ? (XXXSCW: yes. can happen during boot ...) */
379 	if (!cold && pcb != curpcb) {
380 		printf("data_abort: Alert ! pcb(%p) != curpcb(%p)\n",
381 		    pcb, curpcb);
382 		printf("data_abort: Alert ! proc(%p), curlwp(%p)\n",
383 		    p, curlwp);
384 	}
385 #endif	/* DEBUG */
386 
387 	/* Were we in user mode when the abort occurred ? */
388 	if ((frame->tf_spsr & PSR_MODE) == PSR_USR32_MODE) {
389 		/*
390 		 * Note that the fault was from USR mode.
391 		 */
392 		user = 1;
393 		l->l_addr->u_pcb.pcb_tf = frame;
394 	} else
395 		user = 0;
396 
397 	/* check if this was a failed fixup */
398 	if (error == ABORT_FIXUP_FAILED) {
399 		if (user) {
400 			trapsignal(l, SIGSEGV, TRAP_CODE);
401 			userret(l);
402 			return;
403 		};
404 		panic("Data abort fixup failed in kernel - we're dead");
405 	};
406 
407 	/* Now act on the fault type */
408 	if (fatal_fault) {
409 		/*
410 		 * None of these faults should happen on a perfectly
411 		 * functioning system. They indicate either some gross
412 		 * problem with the kernel, or a hardware problem.
413 		 * In either case, stop.
414 		 */
415 		report_abort(NULL, fault_status, fault_address, fault_pc);
416 
417 we_re_toast:
418 		/*
419 		 * Were are dead, try and provide some debug
420 		 * information before dying.
421 		 */
422 #if defined(DDB) || defined(KGDB)
423 		printf("Unhandled trap (frame = %p)\n", frame);
424 		report_abort(NULL, fault_status, fault_address, fault_pc);
425 		kdb_trap(-1, frame);
426 		return;
427 #else
428 		panic("Unhandled trap (frame = %p)", frame);
429 #endif	/* DDB || KGDB */
430 	}
431 
432 	/*
433 	 * At this point, we're dealing with one of the following faults:
434 	 *
435 	 *  FAULT_TRANS_P	Page Translation Fault
436 	 *  FAULT_PERM_P	Page Permission Fault
437 	 *  FAULT_TRANS_S	Section Translation Fault
438 	 *  FAULT_PERM_S	Section Permission Fault
439 	 *
440 	 * And if ARM32_PMAP_NEW is in effect:
441 	 *
442 	 *  FAULT_DOMAIN_P	Page Domain Error Fault
443 	 *  FAULT_DOMAIN_S	Section Domain Error Fault
444 	 *
445 	 * Page/section translation/permission fault -- need to fault in
446 	 * the page.
447 	 *
448 	 * Page/section domain fault -- need to see if the L1 entry can
449 	 * be fixed up.
450 	 */
451 	vm = p->p_vmspace;
452 	va = trunc_page((vaddr_t)fault_address);
453 
454 #ifdef PMAP_DEBUG
455 	if (pmap_debug_level >= 0)
456 		printf("page fault: addr=V%08lx ", va);
457 #endif
458 
459 	/*
460 	 * It is only a kernel address space fault iff:
461 	 *	1. user == 0  and
462 	 *	2. pcb_onfault not set or
463 	 *	3. pcb_onfault set but supervisor space fault
464 	 * The last can occur during an exec() copyin where the
465 	 * argument space is lazy-allocated.
466 	 */
467 	if (!user &&
468 	    (va >= VM_MIN_KERNEL_ADDRESS || va < VM_MIN_ADDRESS)) {
469 		/* Was the fault due to the FPE/IPKDB ? */
470 		if ((frame->tf_spsr & PSR_MODE) == PSR_UND32_MODE) {
471 			report_abort("UND32", fault_status,
472 			    fault_address, fault_pc);
473 			trapsignal(l, SIGSEGV, TRAP_CODE);
474 
475 			/*
476 			 * Force exit via userret()
477 			 * This is necessary as the FPE is an extension
478 			 * to userland that actually runs in a
479 			 * priveledged mode but uses USR mode
480 			 * permissions for its accesses.
481 			 */
482 			userret(l);
483 			return;
484 		}
485 		map = kernel_map;
486 	} else
487 		map = &vm->vm_map;
488 
489 #ifdef PMAP_DEBUG
490 	if (pmap_debug_level >= 0)
491 		printf("vmmap=%p ", map);
492 #endif
493 
494 	if (map == NULL)
495 		printf("No map for fault address va = 0x%08lx", va);
496 
497 	/*
498 	 * We need to know whether the page should be mapped
499 	 * as R or R/W. The MMU does not give us the info as
500 	 * to whether the fault was caused by a read or a write.
501 	 * This means we need to disassemble the instruction
502 	 * responsible and determine if it was a read or write
503 	 * instruction.
504 	 */
505 	/* STR instruction ? */
506 	if ((fault_instruction & 0x0c100000) == 0x04000000)
507 		ftype = VM_PROT_WRITE;
508 	/* STM or CDT instruction ? */
509 	else if ((fault_instruction & 0x0a100000) == 0x08000000)
510 		ftype = VM_PROT_WRITE;
511 	/* STRH, STRSH or STRSB instruction ? */
512 	else if ((fault_instruction & 0x0e100090) == 0x00000090)
513 		ftype = VM_PROT_WRITE;
514 	/* SWP instruction ? */
515 	else if ((fault_instruction & 0x0fb00ff0) == 0x01000090)
516 		ftype = VM_PROT_READ | VM_PROT_WRITE;
517 	else
518 		ftype = VM_PROT_READ;
519 
520 #ifdef PMAP_DEBUG
521 	if (pmap_debug_level >= 0)
522 		printf("fault protection = %d\n", ftype);
523 #endif
524 
525 #ifndef ARM32_PMAP_NEW
526 	if ((ftype & VM_PROT_WRITE) ?
527 	    pmap_modified_emulation(map->pmap, va) :
528 	    pmap_handled_emulation(map->pmap, va))
529 		goto out;
530 #else
531 	if (pmap_fault_fixup(map->pmap, va, ftype, user))
532 		goto out;
533 #endif
534 
535 	if (current_intr_depth > 0) {
536 #if defined(DDB) || defined(KGDB)
537 		printf("Non-emulated page fault with intr_depth > 0\n");
538 		report_abort(NULL, fault_status, fault_address, fault_pc);
539 		kdb_trap(-1, frame);
540 		return;
541 #else
542 		panic("Fault with intr_depth > 0");
543 #endif	/* DDB */
544 	}
545 
546 	onfault = pcb->pcb_onfault;
547 	pcb->pcb_onfault = NULL;
548 	rv = uvm_fault(map, va, 0, ftype);
549 	pcb->pcb_onfault = onfault;
550 	if (rv == 0) {
551 		if (user != 0) /* Record any stack growth... */
552 			uvm_grow(p, trunc_page(va));
553 		goto out;
554 	}
555 	if (user == 0) {
556 		if (pcb->pcb_onfault) {
557 			frame->tf_r0 = rv;
558 			goto copyfault;
559 		}
560 		printf("[u]vm_fault(%p, %lx, %x, 0) -> %x\n", map, va, ftype,
561 		    rv);
562 		goto we_re_toast;
563 	}
564 
565 	report_abort("", fault_status, fault_address, fault_pc);
566 	if (rv == ENOMEM) {
567 		printf("UVM: pid %d (%s), uid %d killed: "
568 		    "out of swap\n", p->p_pid, p->p_comm,
569 		    (p->p_cred && p->p_ucred) ?  p->p_ucred->cr_uid : -1);
570 			trapsignal(l, SIGKILL, TRAP_CODE);
571 	} else
572 		trapsignal(l, SIGSEGV, TRAP_CODE);
573 
574 out:
575 	/* Call userret() if it was a USR mode fault */
576 	if (user)
577 		userret(l);
578 }
579 
580 
581 /*
582  * void prefetch_abort_handler(trapframe_t *frame)
583  *
584  * Abort handler called when instruction execution occurs at
585  * a non existent or restricted (access permissions) memory page.
586  * If the address is invalid and we were in SVC mode then panic as
587  * the kernel should never prefetch abort.
588  * If the address is invalid and the page is mapped then the user process
589  * does no have read permission so send it a signal.
590  * Otherwise fault the page in and try again.
591  */
592 
593 void
594 prefetch_abort_handler(frame)
595 	trapframe_t *frame;
596 {
597 	struct lwp *l;
598 	struct proc *p;
599 	struct vm_map *map;
600 	vaddr_t fault_pc, va;
601 	int error;
602 
603 	/*
604 	 * Enable IRQ's (disabled by the abort) This always comes
605 	 * from user mode so we know interrupts were not disabled.
606 	 * But we check anyway.
607 	 */
608 	if (!(frame->tf_spsr & I32_bit))
609 		enable_interrupts(I32_bit);
610 
611 #ifdef DEBUG
612 	if ((GetCPSR() & PSR_MODE) != PSR_SVC32_MODE)
613 		panic("prefetch_abort_handler: not in SVC32 mode");
614 #endif
615 
616 	/* Update vmmeter statistics */
617 	uvmexp.traps++;
618 
619 	/* Call the cpu specific abort fixup routine */
620 	error = cpu_prefetchabt_fixup(frame);
621 	if (error == ABORT_FIXUP_RETURN)
622 		return;
623 	if (error == ABORT_FIXUP_FAILED)
624 		panic("prefetch abort fixup failed");
625 
626 	/* Get the current proc structure or proc0 if there is none */
627 	if ((l = curlwp) == NULL) {
628 		l = &lwp0;
629 #ifdef DEBUG
630 		printf("Prefetch abort with curlwp == 0\n");
631 #endif
632 	}
633 	p = l->l_proc;
634 
635 #ifdef PMAP_DEBUG
636 	if (pmap_debug_level >= 0)
637 		printf("prefetch fault in process %p %s\n", p, p->p_comm);
638 #endif
639 
640 	/* Get fault address */
641 	fault_pc = frame->tf_pc;
642 	va = trunc_page(fault_pc);
643 
644 	/* Was the prefectch abort from USR32 mode ? */
645 	if ((frame->tf_spsr & PSR_MODE) == PSR_USR32_MODE) {
646 		l->l_addr->u_pcb.pcb_tf = frame;
647 	} else {
648 		/*
649 		 * All the kernel code pages are loaded at boot time
650 		 * and do not get paged
651 		 */
652 	        panic("Prefetch abort in non-USR mode (frame=%p PC=0x%08lx)",
653 	            frame, fault_pc);
654 	}
655 
656 	map = &p->p_vmspace->vm_map;
657 
658 #ifdef PMAP_DEBUG
659 	if (pmap_debug_level >= 0)
660 		printf("prefetch_abort: PC = %08lx\n", fault_pc);
661 #endif
662 	/* Ok validate the address, can only execute in USER space */
663 	if (fault_pc < VM_MIN_ADDRESS || fault_pc >= VM_MAXUSER_ADDRESS) {
664 #ifdef DEBUG
665 		printf("prefetch: pc (%08lx) not in user process space\n",
666 		    fault_pc);
667 #endif
668 		trapsignal(l, SIGSEGV, fault_pc);
669 		userret(l);
670 		return;
671 	}
672 
673 #ifndef ARM32_PMAP_NEW
674 #ifdef CPU_SA110
675 	/*
676 	 * There are bugs in the rev K SA110.  This is a check for one
677 	 * of them.
678 	 */
679 	if (curcpu()->ci_arm_cputype == CPU_ID_SA110 &&
680 	    curcpu()->ci_arm_cpurev < 3) {
681 		/* Always current pmap */
682 		pt_entry_t *pte = vtopte((vaddr_t) fault_pc);
683 		struct pmap *pmap = p->p_vmspace->vm_map.pmap;
684 
685 		if (pmap_pde_v(pmap_pde(pmap, (vaddr_t) fault_pc)) &&
686 		    pmap_pte_v(pte)) {
687 			extern int kernel_debug;
688 			if (kernel_debug & 1) {
689 				printf("prefetch_abort: page is already "
690 				    "mapped - pte=%p *pte=%08x\n", pte, *pte);
691 				printf("prefetch_abort: pc=%08lx proc=%p "
692 				    "process=%s\n", fault_pc, p, p->p_comm);
693 				printf("prefetch_abort: far=%08x fs=%x\n",
694 				    cpu_faultaddress(), cpu_faultstatus());
695 				printf("prefetch_abort: trapframe=%08x\n",
696 				    (u_int)frame);
697 			}
698 #ifdef DDB
699 			if (kernel_debug & 2)
700 				Debugger();
701 #endif
702 		}
703 	}
704 #endif /* CPU_SA110 */
705 
706 	if (pmap_handled_emulation(map->pmap, va))
707 		goto out;
708 
709 #else	/* ARM32_PMAP_NEW */
710 
711 	/*
712 	 * See if the pmap can handle this fault on its own...
713 	 */
714 	if (pmap_fault_fixup(map->pmap, va, VM_PROT_READ, 1))
715 		goto out;
716 #endif
717 
718 	if (current_intr_depth > 0) {
719 #ifdef DDB
720 		printf("Non-emulated prefetch abort with intr_depth > 0\n");
721 		kdb_trap(-1, frame);
722 		return;
723 #else
724 		panic("Prefetch Abort with intr_depth > 0");
725 #endif
726 	}
727 
728 	error = uvm_fault(map, va, 0, VM_PROT_READ);
729 	if (error == 0)
730 		goto out;
731 
732 	if (error == ENOMEM) {
733 		printf("UVM: pid %d (%s), uid %d killed: "
734 		    "out of swap\n", p->p_pid, p->p_comm,
735 		    (p->p_cred && p->p_ucred) ?  p->p_ucred->cr_uid : -1);
736 		trapsignal(l, SIGKILL, fault_pc);
737 	} else
738 		trapsignal(l, SIGSEGV, fault_pc);
739 out:
740 	userret(l);
741 }
742