trap.c revision 1.2
1/*	$NetBSD: trap.c,v 1.2 2001/07/22 11:29:45 wiz Exp $	*/
2
3/*
4 * Copyright 2001 Wasabi Systems, Inc.
5 * All rights reserved.
6 *
7 * Written by Eduardo Horvath and Simon Burge 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/*
39 * Copyright (C) 1995, 1996 Wolfgang Solfrank.
40 * Copyright (C) 1995, 1996 TooLs GmbH.
41 * All rights reserved.
42 *
43 * Redistribution and use in source and binary forms, with or without
44 * modification, are permitted provided that the following conditions
45 * are met:
46 * 1. Redistributions of source code must retain the above copyright
47 *    notice, this list of conditions and the following disclaimer.
48 * 2. Redistributions in binary form must reproduce the above copyright
49 *    notice, this list of conditions and the following disclaimer in the
50 *    documentation and/or other materials provided with the distribution.
51 * 3. All advertising materials mentioning features or use of this software
52 *    must display the following acknowledgement:
53 *	This product includes software developed by TooLs GmbH.
54 * 4. The name of TooLs GmbH may not be used to endorse or promote products
55 *    derived from this software without specific prior written permission.
56 *
57 * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
58 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
59 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
60 * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
61 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
62 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
63 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
64 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
65 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
66 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
67 */
68
69#include "opt_altivec.h"
70#include "opt_ddb.h"
71#include "opt_ktrace.h"
72#include "opt_syscall_debug.h"
73
74#include <sys/param.h>
75#include <sys/proc.h>
76#include <sys/reboot.h>
77#include <sys/syscall.h>
78#include <sys/systm.h>
79#include <sys/user.h>
80#include <sys/ktrace.h>
81
82#include <uvm/uvm_extern.h>
83
84#include <dev/cons.h>
85
86#include <machine/cpu.h>
87#include <machine/db_machdep.h>
88#include <machine/fpu.h>
89#include <machine/frame.h>
90#include <machine/pcb.h>
91#include <machine/psl.h>
92#include <machine/trap.h>
93
94#include <powerpc/spr.h>
95#include <powerpc/ibm4xx/pmap.h>
96#include <powerpc/ibm4xx/tlb.h>
97#include <powerpc/fpu/fpu_extern.h>
98
99/* These definitions should probably be somewhere else			XXX */
100#define	FIRSTARG	3		/* first argument is in reg 3 */
101#define	NARGREG		8		/* 8 args are in registers */
102#define	MOREARGS(sp)	((caddr_t)((int)(sp) + 8)) /* more args go here */
103
104#ifndef MULTIPROCESSOR
105volatile int astpending;
106volatile int want_resched;
107#endif
108
109void *syscall = NULL;	/* XXX dummy symbol for emul_netbsd */
110
111static int fix_unaligned __P((struct proc *p, struct trapframe *frame));
112
113void trap __P((struct trapframe *));	/* Called from locore / trap_subr */
114int setfault __P((faultbuf));	/* defined in locore.S */
115/* Why are these not defined in a header? */
116int badaddr __P((void *, size_t));
117int badaddr_read __P((void *, size_t, int *));
118int ctx_setup __P((int, int));
119
120#ifdef DEBUG
121#define TDB_ALL	0x1
122int trapdebug = /* TDB_ALL */ 0;
123#define	DBPRINTF(x, y)	if (trapdebug & (x)) printf y
124#else
125#define DBPRINTF(x, y)
126#endif
127
128void
129trap(struct trapframe *frame)
130{
131	struct proc *p = curproc;
132	int type = frame->exc;
133	int ftype, rv;
134
135	KASSERT(p == 0 || (p->p_stat == SONPROC));
136
137	if (frame->srr1 & PSL_PR)
138		type |= EXC_USER;
139
140	ftype = VM_PROT_READ;
141
142DBPRINTF(TDB_ALL, ("trap(%x) at %x from frame %p &frame %p\n",
143	type, frame->srr0, frame, &frame));
144
145	switch (type) {
146	case EXC_DEBUG|EXC_USER:
147{
148	int srr2, srr3;
149__asm __volatile("mfspr %0,0x3f0" : "=r" (rv), "=r" (srr2), "=r" (srr3) :);
150printf("debug reg is %x srr2 %x srr3 %x\n", rv, srr2, srr3);
151}
152		/*
153		 * DEBUG intr -- probably single-step.
154		 */
155	case EXC_TRC|EXC_USER:
156		KERNEL_PROC_LOCK(p);
157		frame->srr1 &= ~PSL_SE;
158		trapsignal(p, SIGTRAP, EXC_TRC);
159		KERNEL_PROC_UNLOCK(p);
160		break;
161
162	  /* If we could not find and install appropriate TLB entry, fall through */
163
164	case EXC_DSI:
165		/* FALLTHROUGH */
166	case EXC_DTMISS:
167		{
168			struct vm_map *map;
169			vaddr_t va;
170			faultbuf *fb = NULL;
171
172			KERNEL_LOCK(LK_CANRECURSE|LK_EXCLUSIVE);
173			va = frame->dear;
174			if (frame->pid == KERNEL_PID) {
175				map = kernel_map;
176			} else {
177				map = &p->p_vmspace->vm_map;
178			}
179
180			if (frame->esr & (ESR_DST|ESR_DIZ))
181				ftype = VM_PROT_READ | VM_PROT_WRITE;
182
183DBPRINTF(TDB_ALL, ("trap(EXC_DSI) at %x %s fault on %p esr %x\n",
184frame->srr0, (ftype&VM_PROT_WRITE) ? "write" : "read", (void *)va, frame->esr));
185			rv = uvm_fault(map, trunc_page(va), 0, ftype);
186			KERNEL_UNLOCK();
187			if (rv == 0)
188				goto done;
189			if ((fb = p->p_addr->u_pcb.pcb_onfault) != NULL) {
190				frame->pid = KERNEL_PID;
191				frame->srr0 = (*fb)[0];
192				frame->srr1 |= PSL_IR; /* Re-enable IMMU */
193				frame->fixreg[1] = (*fb)[1];
194				frame->fixreg[2] = (*fb)[2];
195				frame->fixreg[3] = 1; /* Return TRUE */
196				frame->cr = (*fb)[3];
197				memcpy(&frame->fixreg[13], &(*fb)[4],
198				      19 * sizeof(register_t));
199				goto done;
200			}
201		}
202		goto brain_damage;
203
204	case EXC_DSI|EXC_USER:
205		/* FALLTHROUGH */
206	case EXC_DTMISS|EXC_USER:
207		KERNEL_PROC_LOCK(p);
208
209		if (frame->esr & (ESR_DST|ESR_DIZ))
210			ftype = VM_PROT_READ | VM_PROT_WRITE;
211
212DBPRINTF(TDB_ALL, ("trap(EXC_DSI|EXC_USER) at %x %s fault on %x %x\n",
213frame->srr0, (ftype&VM_PROT_WRITE) ? "write" : "read", frame->dear, frame->esr));
214KASSERT(p == curproc && (p->p_stat == SONPROC));
215		rv = uvm_fault(&p->p_vmspace->vm_map,
216			       trunc_page(frame->dear), 0, ftype);
217		if (rv == 0) {
218		  KERNEL_PROC_UNLOCK(p);
219		  break;
220		}
221		if (rv == ENOMEM) {
222			printf("UVM: pid %d (%s), uid %d killed: "
223			       "out of swap\n",
224			       p->p_pid, p->p_comm,
225			       p->p_cred && p->p_ucred ?
226			       p->p_ucred->cr_uid : -1);
227			trapsignal(p, SIGKILL, EXC_DSI);
228		} else {
229			trapsignal(p, SIGSEGV, EXC_DSI);
230		}
231		KERNEL_PROC_UNLOCK(p);
232		break;
233	case EXC_ITMISS|EXC_USER:
234	case EXC_ISI|EXC_USER:
235		KERNEL_PROC_LOCK(p);
236		ftype = VM_PROT_READ | VM_PROT_EXECUTE;
237DBPRINTF(TDB_ALL, ("trap(EXC_ISI|EXC_USER) at %x %s fault on %x tf %p\n",
238frame->srr0, (ftype&VM_PROT_WRITE) ? "write" : "read", frame->srr0, frame));
239		rv = uvm_fault(&p->p_vmspace->vm_map, trunc_page(frame->srr0), 0, ftype);
240		if (rv == 0) {
241		  KERNEL_PROC_UNLOCK(p);
242		  break;
243		}
244		trapsignal(p, SIGSEGV, EXC_ISI);
245		KERNEL_PROC_UNLOCK(p);
246		break;
247	case EXC_SC|EXC_USER:
248		{
249			const struct sysent *callp;
250			size_t argsize;
251			register_t code, error;
252			register_t *params, rval[2];
253			int n;
254			register_t args[10];
255
256			KERNEL_PROC_LOCK(p);
257
258			uvmexp.syscalls++;
259
260			code = frame->fixreg[0];
261			callp = p->p_emul->e_sysent;
262			params = frame->fixreg + FIRSTARG;
263			n = NARGREG;
264
265			switch (code) {
266			case SYS_syscall:
267				/*
268				 * code is first argument,
269				 * followed by actual args.
270				 */
271				code = *params++;
272				n -= 1;
273				break;
274			case SYS___syscall:
275				params++;
276				code = *params++;
277				n -= 2;
278				break;
279			default:
280				break;
281			}
282
283			code &= (SYS_NSYSENT - 1);
284			callp += code;
285			argsize = callp->sy_argsize;
286
287			if (argsize > n * sizeof(register_t)) {
288				memcpy(args, params, n * sizeof(register_t));
289				error = copyin(MOREARGS(frame->fixreg[1]),
290					       args + n,
291					       argsize - n * sizeof(register_t));
292				if (error)
293					goto syscall_bad;
294				params = args;
295			}
296
297#ifdef	KTRACE
298			if (KTRPOINT(p, KTR_SYSCALL))
299				ktrsyscall(p, code, argsize, params);
300#endif
301#ifdef SYSCALL_DEBUG
302			if (trapdebug)
303				scdebug_call(p, code, args);
304#endif
305			rval[0] = 0;
306			rval[1] = 0;
307
308			error = (*callp->sy_call)(p, params, rval);
309#ifdef SYSCALL_DEBUG
310			if (trapdebug)
311				scdebug_ret(p, code, error, rval);
312#endif
313			switch (error) {
314			case 0:
315				frame->fixreg[FIRSTARG] = rval[0];
316				frame->fixreg[FIRSTARG + 1] = rval[1];
317				frame->cr &= ~0x10000000;
318				break;
319			case ERESTART:
320				/*
321				 * Set user's pc back to redo the system call.
322				 */
323				frame->srr0 -= 4;
324				break;
325			case EJUSTRETURN:
326				/* nothing to do */
327				break;
328			default:
329syscall_bad:
330				if (p->p_emul->e_errno)
331					error = p->p_emul->e_errno[error];
332				frame->fixreg[FIRSTARG] = error;
333				frame->cr |= 0x10000000;
334				break;
335			}
336
337#ifdef	KTRACE
338			if (KTRPOINT(p, KTR_SYSRET))
339				ktrsysret(p, code, error, rval[0]);
340#endif
341		}
342		KERNEL_PROC_UNLOCK(p);
343		break;
344
345	case EXC_AST|EXC_USER:
346		astpending = 0;		/* we are about to do it */
347		KERNEL_PROC_LOCK(p);
348		uvmexp.softs++;
349		if (p->p_flag & P_OWEUPC) {
350			p->p_flag &= ~P_OWEUPC;
351			ADDUPROF(p);
352		}
353		/* Check whether we are being preempted. */
354		if (want_resched)
355			preempt(NULL);
356		KERNEL_PROC_UNLOCK(p);
357		break;
358
359
360	case EXC_ALI|EXC_USER:
361		KERNEL_PROC_LOCK(p);
362		if (fix_unaligned(p, frame) != 0)
363			trapsignal(p, SIGBUS, EXC_ALI);
364		else
365			frame->srr0 += 4;
366		KERNEL_PROC_UNLOCK(p);
367		break;
368
369	case EXC_PGM|EXC_USER:
370		/*
371		 * Illegal insn:
372		 *
373		 * let's try to see if it's FPU and can be emulated.
374		 */
375		uvmexp.traps ++;
376		if (!(p->p_addr->u_pcb.pcb_flags & PCB_FPU)) {
377			memset(&p->p_addr->u_pcb.pcb_fpu, 0,
378				sizeof p->p_addr->u_pcb.pcb_fpu);
379			p->p_addr->u_pcb.pcb_flags |= PCB_FPU;
380		}
381
382		if ((rv = fpu_emulate(frame,
383			(struct fpreg *)&p->p_addr->u_pcb.pcb_fpu))) {
384			KERNEL_PROC_LOCK(p);
385			trapsignal(p, rv, EXC_PGM);
386			KERNEL_PROC_UNLOCK(p);
387		}
388		break;
389
390	case EXC_MCHK:
391		{
392			faultbuf *fb;
393
394			if ((fb = p->p_addr->u_pcb.pcb_onfault) != NULL) {
395				frame->pid = KERNEL_PID;
396				frame->srr0 = (*fb)[0];
397				frame->srr1 |= PSL_IR; /* Re-enable IMMU */
398				frame->fixreg[1] = (*fb)[1];
399				frame->fixreg[2] = (*fb)[2];
400				frame->fixreg[3] = 1; /* Return TRUE */
401				frame->cr = (*fb)[3];
402				memcpy(&frame->fixreg[13], &(*fb)[4],
403				      19 * sizeof(register_t));
404				goto done;
405			}
406		}
407		goto brain_damage;
408	default:
409brain_damage:
410		printf("trap type 0x%x at 0x%x\n", type, frame->srr0);
411#ifdef DDB
412		if (kdb_trap(type, frame))
413			goto done;
414#endif
415#ifdef TRAP_PANICWAIT
416		printf("Press a key to panic.\n");
417		cngetc();
418#endif
419		panic("trap");
420	}
421
422	/* Take pending signals. */
423	{
424		int sig;
425
426		while ((sig = CURSIG(p)) != 0)
427			postsig(sig);
428	}
429
430	curcpu()->ci_schedstate.spc_curpriority = p->p_priority = p->p_usrpri;
431  done:
432}
433
434int
435ctx_setup(int ctx, int srr1)
436{
437	volatile struct pmap *pm;
438
439	/* Update PID if we're returning to user mode. */
440	if (srr1 & PSL_PR) {
441		pm = curproc->p_vmspace->vm_map.pmap;
442		if (!pm->pm_ctx) {
443			ctx_alloc((struct pmap *)pm);
444		}
445		ctx = pm->pm_ctx;
446		if (srr1 & PSL_SE) {
447			int dbreg, mask = 0x48000000;
448				/*
449				 * Set the Internal Debug and
450				 * Instruction Completion bits of
451				 * the DBCR0 register.
452				 *
453				 * XXX this is also used by jtag debuggers...
454				 */
455			__asm __volatile("mfspr %0,0x3f2;"
456				"or %0,%0,%1;"
457				"mtspr 0x3f2,%0;" :
458				"=&r" (dbreg) : "r" (mask));
459		}
460	}
461	else if (!ctx) {
462		ctx = KERNEL_PID;
463	}
464	return (ctx);
465}
466
467void
468child_return(void *arg)
469{
470	struct proc *p = arg;
471	struct trapframe *tf = trapframe(p);
472
473	KERNEL_PROC_UNLOCK(p);
474
475	tf->fixreg[FIRSTARG] = 0;
476	tf->fixreg[FIRSTARG + 1] = 1;
477	tf->cr &= ~0x10000000;
478	tf->srr1 &= ~(PSL_FP|PSL_VEC);	/* Disable FP & AltiVec, as we can't be them */
479#ifdef	KTRACE
480	if (KTRPOINT(p, KTR_SYSRET)) {
481		KERNEL_PROC_LOCK(p);
482		ktrsysret(p, SYS_fork, 0, 0);
483		KERNEL_PROC_UNLOCK(p);
484	}
485#endif
486	/* Profiling?							XXX */
487	curcpu()->ci_schedstate.spc_curpriority = p->p_priority;
488}
489
490/*
491 * Used by copyin()/copyout()
492 */
493extern vaddr_t vmaprange __P((struct proc *, vaddr_t, vsize_t, int));
494extern void vunmaprange __P((vaddr_t, vsize_t));
495static int bigcopyin __P((const void *,	void *,	size_t ));
496static int bigcopyout __P((const void *, void *, size_t ));
497
498int
499copyin(const void *udaddr, void *kaddr, size_t len)
500{
501	struct pmap *pm = curproc->p_vmspace->vm_map.pmap;
502	int msr, pid, tmp, ctx;
503	faultbuf env;
504
505	/* For bigger buffers use the faster copy */
506	if (len > 256) return (bigcopyin(udaddr, kaddr, len));
507
508	if (setfault(env)) {
509		curpcb->pcb_onfault = 0;
510		return EFAULT;
511	}
512
513	if (!(ctx = pm->pm_ctx)) {
514		/* No context -- assign it one */
515		ctx_alloc(pm);
516		ctx = pm->pm_ctx;
517	}
518
519	asm volatile("addi %6,%6,1; mtctr %6;"	/* Set up counter */
520		"mfmsr %0;"			/* Save MSR */
521		"li %1,0x20; "
522		"andc %1,%0,%1; mtmsr %1;"	/* Disable IMMU */
523		"mfpid %1;"			/* Save old PID */
524		"sync; isync;"
525
526		"1: bdz 2f;"			/* while len */
527		"mtpid %3; sync;"		/* Load user ctx */
528		"lbz %2,0(%4); addi %4,%4,1;"	/* Load byte */
529		"sync; isync;"
530		"mtpid %1;sync;"
531		"stb %2,0(%5); dcbf 0,%5; addi %5,%5,1;"	/* Store kernel byte */
532		"sync; isync;"
533		"b 1b;"				/* repeat */
534
535		"2: mtpid %1; mtmsr %0;"	/* Restore PID and MSR */
536		"sync; isync;"
537		: "=&r" (msr), "=&r" (pid), "=&r" (tmp)
538		: "r" (ctx), "r" (udaddr), "r" (kaddr), "r" (len));
539
540	curpcb->pcb_onfault = 0;
541	return 0;
542}
543
544static int
545bigcopyin(const void *udaddr, void *kaddr, size_t len)
546{
547	const char *up;
548	char *kp = kaddr;
549	struct proc *p = curproc;
550	int error;
551
552	if (!p) {
553		return EFAULT;
554	}
555
556	/*
557	 * Stolen from physio():
558	 */
559	PHOLD(p);
560	error = uvm_vslock(p, (caddr_t)udaddr, len, VM_PROT_READ);
561	if (error) {
562		PRELE(p);
563		return EFAULT;
564	}
565	up = (char *)vmaprange(p, (vaddr_t)udaddr, len, VM_PROT_READ);
566
567	memcpy(kp, up, len);
568	vunmaprange((vaddr_t)up, len);
569	uvm_vsunlock(p, (caddr_t)udaddr, len);
570	PRELE(p);
571
572	return 0;
573}
574
575int
576copyout(const void *kaddr, void *udaddr, size_t len)
577{
578	struct pmap *pm = curproc->p_vmspace->vm_map.pmap;
579	int msr, pid, tmp, ctx;
580	faultbuf env;
581
582	/* For big copies use more efficient routine */
583	if (len > 256) return (bigcopyout(kaddr, udaddr, len));
584
585	if (setfault(env)) {
586		curpcb->pcb_onfault = 0;
587		return EFAULT;
588	}
589
590	if (!(ctx = pm->pm_ctx)) {
591		/* No context -- assign it one */
592		ctx_alloc(pm);
593		ctx = pm->pm_ctx;
594	}
595
596	asm volatile("addi %6,%6,1; mtctr %6;"	/* Set up counter */
597		"mfmsr %0;"			/* Save MSR */
598		"li %1,0x20; "
599		"andc %1,%0,%1; mtmsr %1;"	/* Disable IMMU */
600		"mfpid %1;"			/* Save old PID */
601		"sync; isync;"
602
603		"1: bdz 2f;"			/* while len */
604		"mtpid %1;sync;"
605		"lbz %2,0(%5); addi %5,%5,1;"	/* Load kernel byte */
606		"sync; isync;"
607		"mtpid %3; sync;"		/* Load user ctx */
608		"stb %2,0(%4);  dcbf 0,%4; addi %4,%4,1;"	/* Store user byte */
609		"sync; isync;"
610		"b 1b;"				/* repeat */
611
612		"2: mtpid %1; mtmsr %0;"	/* Restore PID and MSR */
613		"sync; isync;"
614		: "=&r" (msr), "=&r" (pid), "=&r" (tmp)
615		: "r" (ctx), "r" (udaddr), "r" (kaddr), "r" (len));
616
617	curpcb->pcb_onfault = 0;
618	return 0;
619}
620
621static int
622bigcopyout(const void *kaddr, void *udaddr, size_t len)
623{
624	char *up;
625	const char *kp = (char *)kaddr;
626	struct proc *p = curproc;
627	int error;
628
629	if (!p) {
630		return EFAULT;
631	}
632
633	/*
634	 * Stolen from physio():
635	 */
636	PHOLD(p);
637	error = uvm_vslock(p, udaddr, len, VM_PROT_READ|VM_PROT_WRITE);
638	if (error) {
639		PRELE(p);
640		return EFAULT;
641	}
642	up = (char *)vmaprange(p, (vaddr_t)udaddr, len,
643		VM_PROT_READ|VM_PROT_WRITE);
644
645	memcpy(up, kp, len);
646	vunmaprange((vaddr_t)up, len);
647	uvm_vsunlock(p, udaddr, len);
648	PRELE(p);
649
650	return 0;
651}
652
653/*
654 * kcopy(const void *src, void *dst, size_t len);
655 *
656 * Copy len bytes from src to dst, aborting if we encounter a fatal
657 * page fault.
658 *
659 * kcopy() _must_ save and restore the old fault handler since it is
660 * called by uiomove(), which may be in the path of servicing a non-fatal
661 * page fault.
662 */
663int
664kcopy(const void *src, void *dst, size_t len)
665{
666	faultbuf env, *oldfault;
667
668	oldfault = curpcb->pcb_onfault;
669	if (setfault(env)) {
670		curpcb->pcb_onfault = oldfault;
671		return EFAULT;
672	}
673
674	memcpy(dst, src, len);
675
676	curpcb->pcb_onfault = oldfault;
677	return 0;
678}
679
680int
681badaddr(void *addr, size_t size)
682{
683
684	return badaddr_read(addr, size, NULL);
685}
686
687int
688badaddr_read(void *addr, size_t size, int *rptr)
689{
690	faultbuf env;
691	int x;
692
693	/* Get rid of any stale machine checks that have been waiting.  */
694	__asm __volatile ("sync; isync");
695
696	if (setfault(env)) {
697		curpcb->pcb_onfault = 0;
698		__asm __volatile ("sync");
699		return 1;
700	}
701
702	__asm __volatile ("sync");
703
704	switch (size) {
705	case 1:
706		x = *(volatile int8_t *)addr;
707		break;
708	case 2:
709		x = *(volatile int16_t *)addr;
710		break;
711	case 4:
712		x = *(volatile int32_t *)addr;
713		break;
714	default:
715		panic("badaddr: invalid size (%d)", size);
716	}
717
718	/* Make sure we took the machine check, if we caused one. */
719	__asm __volatile ("sync; isync");
720
721	curpcb->pcb_onfault = 0;
722	__asm __volatile ("sync");	/* To be sure. */
723
724	/* Use the value to avoid reorder. */
725	if (rptr)
726		*rptr = x;
727
728	return 0;
729}
730
731/*
732 * For now, this only deals with the particular unaligned access case
733 * that gcc tends to generate.  Eventually it should handle all of the
734 * possibilities that can happen on a 32-bit PowerPC in big-endian mode.
735 */
736
737static int
738fix_unaligned(struct proc *p, struct trapframe *frame)
739{
740
741	return -1;
742}
743