trap.c revision 1.46
1/*	$NetBSD: trap.c,v 1.46 2007/11/22 13:33:08 hpeyerl 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 <sys/cdefs.h>
70__KERNEL_RCSID(0, "$NetBSD: trap.c,v 1.46 2007/11/22 13:33:08 hpeyerl Exp $");
71
72#include "opt_altivec.h"
73#include "opt_ddb.h"
74#include "opt_kgdb.h"
75
76#include <sys/param.h>
77#include <sys/proc.h>
78#include <sys/reboot.h>
79#include <sys/syscall.h>
80#include <sys/systm.h>
81#include <sys/user.h>
82#include <sys/pool.h>
83#include <sys/userret.h>
84#include <sys/kauth.h>
85
86#if defined(KGDB)
87#include <sys/kgdb.h>
88#endif
89
90#include <uvm/uvm_extern.h>
91
92#include <dev/cons.h>
93
94#include <machine/cpu.h>
95#include <machine/db_machdep.h>
96#include <machine/fpu.h>
97#include <machine/frame.h>
98#include <machine/pcb.h>
99#include <machine/psl.h>
100#include <machine/trap.h>
101
102#include <powerpc/spr.h>
103#include <powerpc/ibm4xx/pmap.h>
104#include <powerpc/ibm4xx/tlb.h>
105#include <powerpc/fpu/fpu_extern.h>
106
107/* These definitions should probably be somewhere else			XXX */
108#define	FIRSTARG	3		/* first argument is in reg 3 */
109#define	NARGREG		8		/* 8 args are in registers */
110#define	MOREARGS(sp)	((void *)((int)(sp) + 8)) /* more args go here */
111
112static int fix_unaligned __P((struct lwp *l, struct trapframe *frame));
113
114void trap __P((struct trapframe *));	/* Called from locore / trap_subr */
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 lwp *l = curlwp;
132	struct proc *p = l ? l->l_proc : NULL;
133	int type = frame->exc;
134	int ftype, rv;
135	ksiginfo_t ksi;
136
137	KASSERT(l == 0 || (l->l_stat == LSONPROC));
138
139	if (frame->srr1 & PSL_PR) {
140		LWP_CACHE_CREDS(l, p);
141		type |= EXC_USER;
142	}
143
144	ftype = VM_PROT_READ;
145
146	DBPRINTF(TDB_ALL, ("trap(%x) at %lx from frame %p &frame %p\n",
147	    type, frame->srr0, frame, &frame));
148
149	switch (type) {
150	case EXC_DEBUG|EXC_USER:
151		{
152			int srr2, srr3;
153
154			__asm volatile("mfspr %0,0x3f0" :
155			    "=r" (rv), "=r" (srr2), "=r" (srr3) :);
156			printf("debug reg is %x srr2 %x srr3 %x\n", rv, srr2,
157			    srr3);
158			/* XXX fall through or break here?! */
159		}
160		/*
161		 * DEBUG intr -- probably single-step.
162		 */
163	case EXC_TRC|EXC_USER:
164		frame->srr1 &= ~PSL_SE;
165		KSI_INIT_TRAP(&ksi);
166		ksi.ksi_signo = SIGTRAP;
167		ksi.ksi_trap = EXC_TRC;
168		ksi.ksi_addr = (void *)frame->srr0;
169		KERNEL_LOCK(1, l);
170		trapsignal(l, &ksi);
171		KERNEL_UNLOCK_LAST(l);
172		break;
173
174	/*
175	 * If we could not find and install appropriate TLB entry, fall through.
176	 */
177
178	case EXC_DSI:
179		/* FALLTHROUGH */
180	case EXC_DTMISS:
181		{
182			struct vm_map *map;
183			vaddr_t va;
184			struct faultbuf *fb = NULL;
185
186			KERNEL_LOCK(1, NULL);
187			va = frame->dar;
188			if (frame->tf_xtra[TF_PID] == KERNEL_PID) {
189				map = kernel_map;
190			} else {
191				map = &p->p_vmspace->vm_map;
192			}
193
194			if (frame->tf_xtra[TF_ESR] & (ESR_DST|ESR_DIZ))
195				ftype = VM_PROT_WRITE;
196
197			DBPRINTF(TDB_ALL,
198			    ("trap(EXC_DSI) at %lx %s fault on %p esr %x\n",
199			    frame->srr0,
200			    (ftype & VM_PROT_WRITE) ? "write" : "read",
201			    (void *)va, frame->tf_xtra[TF_ESR]));
202			rv = uvm_fault(map, trunc_page(va), ftype);
203			KERNEL_UNLOCK_ONE(NULL);
204			if (rv == 0)
205				goto done;
206			if ((fb = l->l_addr->u_pcb.pcb_onfault) != NULL) {
207				frame->tf_xtra[TF_PID] = KERNEL_PID;
208				frame->srr0 = fb->fb_pc;
209				frame->srr1 |= PSL_IR; /* Re-enable IMMU */
210				frame->fixreg[1] = fb->fb_sp;
211				frame->fixreg[2] = fb->fb_r2;
212				frame->fixreg[3] = 1; /* Return TRUE */
213				frame->cr = fb->fb_cr;
214				memcpy(&frame->fixreg[13], fb->fb_fixreg,
215				    sizeof(fb->fb_fixreg));
216				goto done;
217			}
218		}
219		goto brain_damage;
220
221	case EXC_DSI|EXC_USER:
222		/* FALLTHROUGH */
223	case EXC_DTMISS|EXC_USER:
224		KERNEL_LOCK(1, l);
225
226		if (frame->tf_xtra[TF_ESR] & (ESR_DST|ESR_DIZ))
227			ftype = VM_PROT_WRITE;
228
229		DBPRINTF(TDB_ALL,
230		    ("trap(EXC_DSI|EXC_USER) at %lx %s fault on %lx %x\n",
231		    frame->srr0, (ftype & VM_PROT_WRITE) ? "write" : "read",
232		    frame->dar, frame->tf_xtra[TF_ESR]));
233		KASSERT(l == curlwp && (l->l_stat == LSONPROC));
234		rv = uvm_fault(&p->p_vmspace->vm_map, trunc_page(frame->dar),
235		    ftype);
236		if (rv == 0) {
237			KERNEL_UNLOCK_LAST(l);
238			break;
239		}
240		KSI_INIT_TRAP(&ksi);
241		ksi.ksi_signo = SIGSEGV;
242		ksi.ksi_trap = EXC_DSI;
243		ksi.ksi_addr = (void *)frame->dar;
244		if (rv == ENOMEM) {
245			printf("UVM: pid %d (%s) lid %d, uid %d killed: "
246			    "out of swap\n",
247			    p->p_pid, p->p_comm, l->l_lid,
248			    l->l_cred ?
249			    kauth_cred_geteuid(l->l_cred) : -1);
250			ksi.ksi_signo = SIGKILL;
251		}
252		trapsignal(l, &ksi);
253		KERNEL_UNLOCK_LAST(l);
254		break;
255
256	case EXC_ITMISS|EXC_USER:
257	case EXC_ISI|EXC_USER:
258		KERNEL_LOCK(1, l);
259		ftype = VM_PROT_EXECUTE;
260		DBPRINTF(TDB_ALL,
261		    ("trap(EXC_ISI|EXC_USER) at %lx execute fault tf %p\n",
262		    frame->srr0, frame));
263		rv = uvm_fault(&p->p_vmspace->vm_map, trunc_page(frame->srr0),
264		    ftype);
265		if (rv == 0) {
266			KERNEL_UNLOCK_LAST(l);
267			break;
268		}
269		KSI_INIT_TRAP(&ksi);
270		ksi.ksi_signo = SIGSEGV;
271		ksi.ksi_trap = EXC_ISI;
272		ksi.ksi_addr = (void *)frame->srr0;
273		ksi.ksi_code = (rv == EACCES ? SEGV_ACCERR : SEGV_MAPERR);
274		trapsignal(l, &ksi);
275		KERNEL_UNLOCK_LAST(l);
276		break;
277
278	case EXC_AST|EXC_USER:
279		curcpu()->ci_astpending = 0;	/* we are about to do it */
280		uvmexp.softs++;
281		if (l->l_pflag & LP_OWEUPC) {
282			l->l_pflag &= ~LP_OWEUPC;
283			ADDUPROF(l);
284		}
285		/* Check whether we are being preempted. */
286		if (curcpu()->ci_want_resched)
287			preempt();
288		break;
289
290
291	case EXC_ALI|EXC_USER:
292		KERNEL_LOCK(1, l);
293		if (fix_unaligned(l, frame) != 0) {
294			KSI_INIT_TRAP(&ksi);
295			ksi.ksi_signo = SIGBUS;
296			ksi.ksi_trap = EXC_ALI;
297			ksi.ksi_addr = (void *)frame->dar;
298			trapsignal(l, &ksi);
299		} else
300			frame->srr0 += 4;
301		KERNEL_UNLOCK_LAST(l);
302		break;
303
304	case EXC_PGM|EXC_USER:
305		/*
306		 * Illegal insn:
307		 *
308		 * let's try to see if it's FPU and can be emulated.
309		 */
310		uvmexp.traps++;
311		if (!(l->l_addr->u_pcb.pcb_flags & PCB_FPU)) {
312			memset(&l->l_addr->u_pcb.pcb_fpu, 0,
313				sizeof l->l_addr->u_pcb.pcb_fpu);
314			l->l_addr->u_pcb.pcb_flags |= PCB_FPU;
315		}
316
317		if ((rv = fpu_emulate(frame,
318			(struct fpreg *)&l->l_addr->u_pcb.pcb_fpu))) {
319			KSI_INIT_TRAP(&ksi);
320			ksi.ksi_signo = rv;
321			ksi.ksi_trap = EXC_PGM;
322			ksi.ksi_addr = (void *)frame->srr0;
323			KERNEL_LOCK(1, l);
324			trapsignal(l, &ksi);
325			KERNEL_UNLOCK_LAST(l);
326		}
327		break;
328
329	case EXC_MCHK:
330		{
331			struct faultbuf *fb;
332
333			if ((fb = l->l_addr->u_pcb.pcb_onfault) != NULL) {
334				frame->tf_xtra[TF_PID] = KERNEL_PID;
335				frame->srr0 = fb->fb_pc;
336				frame->srr1 |= PSL_IR; /* Re-enable IMMU */
337				frame->fixreg[1] = fb->fb_sp;
338				frame->fixreg[2] = fb->fb_r2;
339				frame->fixreg[3] = 1; /* Return TRUE */
340				frame->cr = fb->fb_cr;
341				memcpy(&frame->fixreg[13], fb->fb_fixreg,
342				    sizeof(fb->fb_fixreg));
343				goto done;
344			}
345		}
346		goto brain_damage;
347	default:
348 brain_damage:
349		printf("trap type 0x%x at 0x%lx\n", type, frame->srr0);
350#if defined(DDB) || defined(KGDB)
351		if (kdb_trap(type, frame))
352			goto done;
353#endif
354#ifdef TRAP_PANICWAIT
355		printf("Press a key to panic.\n");
356		cngetc();
357#endif
358		panic("trap");
359	}
360
361	/* Invoke MI userret code */
362	mi_userret(l);
363 done:
364	return;
365}
366
367int
368ctx_setup(int ctx, int srr1)
369{
370	volatile struct pmap *pm;
371
372	/* Update PID if we're returning to user mode. */
373	if (srr1 & PSL_PR) {
374		pm = curproc->p_vmspace->vm_map.pmap;
375		if (!pm->pm_ctx) {
376			ctx_alloc(__UNVOLATILE(pm));
377		}
378		ctx = pm->pm_ctx;
379		if (srr1 & PSL_SE) {
380			int dbreg, mask = 0x48000000;
381				/*
382				 * Set the Internal Debug and
383				 * Instruction Completion bits of
384				 * the DBCR0 register.
385				 *
386				 * XXX this is also used by jtag debuggers...
387				 */
388			__asm volatile("mfspr %0,0x3f2;"
389			    "or %0,%0,%1;"
390			    "mtspr 0x3f2,%0;" :
391			    "=&r" (dbreg) : "r" (mask));
392		}
393	}
394	else if (!ctx) {
395		ctx = KERNEL_PID;
396	}
397	return (ctx);
398}
399
400/*
401 * Used by copyin()/copyout()
402 */
403extern vaddr_t vmaprange __P((struct proc *, vaddr_t, vsize_t, int));
404extern void vunmaprange __P((vaddr_t, vsize_t));
405static int bigcopyin __P((const void *, void *, size_t ));
406static int bigcopyout __P((const void *, void *, size_t ));
407
408int
409copyin(const void *udaddr, void *kaddr, size_t len)
410{
411	struct pmap *pm = curproc->p_vmspace->vm_map.pmap;
412	int msr, pid, tmp, ctx, count=0;
413	struct faultbuf env;
414
415	/* For bigger buffers use the faster copy */
416	if (len > 1024)
417		return (bigcopyin(udaddr, kaddr, len));
418
419	if (setfault(&env)) {
420		curpcb->pcb_onfault = 0;
421		return EFAULT;
422	}
423
424	if (!(ctx = pm->pm_ctx)) {
425		/* No context -- assign it one */
426		ctx_alloc(pm);
427		ctx = pm->pm_ctx;
428	}
429
430	__asm volatile(
431		"   mfmsr %[msr];"          /* Save MSR */
432		"   li %[pid],0x20; "
433		"   andc %[pid],%[msr],%[pid]; mtmsr %[pid];"   /* Disable IMMU */
434		"   mfpid %[pid];"          /* Save old PID */
435		"   sync; isync;"
436
437		"   srwi. %[count],%[len],0x2;"     /* How many words? */
438		"   beq-  2f;"              /* No words. Go do bytes */
439		"   mtctr %[count];"
440		"1: mtpid %[ctx]; sync;"
441		"   lwz %[tmp],0(%[udaddr]);"       /* Load user word */
442		"   addi %[udaddr],%[udaddr],0x4;"  /* next udaddr word */
443		"   sync; isync;"
444		"   mtpid %[pid];sync;"
445		"   stw %[tmp],0(%[kaddr]);"        /* Store kernel word */
446		"   dcbf 0,%[kaddr];"           /* flush cache */
447		"   addi %[kaddr],%[kaddr],0x4;"    /* next udaddr word */
448		"   sync; isync;"
449		"   bdnz 1b;"               /* repeat */
450
451		"2: andi. %[count],%[len],0x3;"     /* How many remaining bytes? */
452		"   addi %[count],%[count],0x1;"
453		"   mtctr %[count];"
454		"3: bdz 10f;"               /* while count */
455		"   mtpid %[ctx];sync;"
456		"   lbz %[tmp],0(%[udaddr]);"       /* Load user byte */
457		"   addi %[udaddr],%[udaddr],0x1;"  /* next udaddr byte */
458		"   sync; isync;"
459		"   mtpid %[pid]; sync;"
460		"   stb %[tmp],0(%[kaddr]);"        /* Store kernel byte */
461		"   dcbf 0,%[kaddr];"           /* flush cache */
462		"   addi %[kaddr],%[kaddr],0x1;"
463		"   sync; isync;"
464		"   b 3b;"
465		"10:mtpid %[pid]; mtmsr %[msr]; sync; isync;" /* Restore PID and MSR */
466		: [msr] "=&r" (msr), [pid] "=&r" (pid), [tmp] "=&r" (tmp)
467		: [udaddr] "b" (udaddr), [ctx] "b" (ctx), [kaddr] "b" (kaddr), [len] "b" (len), [count] "b" (count));
468
469	curpcb->pcb_onfault = 0;
470	return 0;
471}
472
473static int
474bigcopyin(const void *udaddr, void *kaddr, size_t len)
475{
476	const char *up;
477	char *kp = kaddr;
478	struct lwp *l = curlwp;
479	struct proc *p;
480	int error;
481
482	if (!l) {
483		return EFAULT;
484	}
485
486	p = l->l_proc;
487
488	/*
489	 * Stolen from physio():
490	 */
491	uvm_lwp_hold(l);
492	error = uvm_vslock(p->p_vmspace, __UNCONST(udaddr), len, VM_PROT_READ);
493	if (error) {
494		uvm_lwp_rele(l);
495		return EFAULT;
496	}
497	up = (char *)vmaprange(p, (vaddr_t)udaddr, len, VM_PROT_READ);
498
499	memcpy(kp, up, len);
500	vunmaprange((vaddr_t)up, len);
501	uvm_vsunlock(p->p_vmspace, __UNCONST(udaddr), len);
502	uvm_lwp_rele(l);
503
504	return 0;
505}
506
507int
508copyout(const void *kaddr, void *udaddr, size_t len)
509{
510	struct pmap *pm = curproc->p_vmspace->vm_map.pmap;
511	int msr, pid, tmp, ctx, count=0;
512	struct faultbuf env;
513
514	/* For big copies use more efficient routine */
515	if (len > 1024)
516		return (bigcopyout(kaddr, udaddr, len));
517
518	if (setfault(&env)) {
519		curpcb->pcb_onfault = 0;
520		return EFAULT;
521	}
522
523	if (!(ctx = pm->pm_ctx)) {
524		/* No context -- assign it one */
525		ctx_alloc(pm);
526		ctx = pm->pm_ctx;
527	}
528
529	__asm volatile(
530		"   mfmsr %[msr];"          /* Save MSR */ \
531		"   li %[pid],0x20; " \
532		"   andc %[pid],%[msr],%[pid]; mtmsr %[pid];"   /* Disable IMMU */ \
533		"   mfpid %[pid];"          /* Save old PID */ \
534		"   sync; isync;"
535
536		"   srwi. %[count],%[len],0x2;"     /* How many words? */
537		"   beq-  2f;"              /* No words. Go do bytes */
538		"   mtctr %[count];"
539		"1: mtpid %[pid];sync;"
540		"   lwz %[tmp],0(%[kaddr]);"        /* Load kernel word */
541		"   addi %[kaddr],%[kaddr],0x4;"    /* next kaddr word */
542		"   sync; isync;"
543		"   mtpid %[ctx]; sync;"
544		"   stw %[tmp],0(%[udaddr]);"       /* Store user word */
545		"   dcbf 0,%[udaddr];"          /* flush cache */
546		"   addi %[udaddr],%[udaddr],0x4;"  /* next udaddr word */
547		"   sync; isync;"
548		"   bdnz 1b;"               /* repeat */
549
550		"2: andi. %[count],%[len],0x3;"     /* How many remaining bytes? */
551		"   addi %[count],%[count],0x1;"
552		"   mtctr %[count];"
553		"3: bdz  10f;"              /* while count */
554		"   mtpid %[pid];sync;"
555		"   lbz %[tmp],0(%[kaddr]);"        /* Load kernel byte */
556		"   addi %[kaddr],%[kaddr],0x1;"    /* next kaddr byte */
557		"   sync; isync;"
558		"   mtpid %[ctx]; sync;"
559		"   stb %[tmp],0(%[udaddr]);"       /* Store user byte */
560		"   dcbf 0,%[udaddr];"          /* flush cache */
561		"   addi %[udaddr],%[udaddr],0x1;"
562		"   sync; isync;"
563		"   b 3b;"
564		"10:mtpid %[pid]; mtmsr %[msr]; sync; isync;" /* Restore PID and MSR */
565		: [msr] "=&r" (msr), [pid] "=&r" (pid), [tmp] "=&r" (tmp)
566		: [udaddr] "b" (udaddr), [ctx] "b" (ctx), [kaddr] "b" (kaddr), [len] "b" (len), [count] "b" (count));
567
568	curpcb->pcb_onfault = 0;
569	return 0;
570}
571
572static int
573bigcopyout(const void *kaddr, void *udaddr, size_t len)
574{
575	char *up;
576	const char *kp = (const char *)kaddr;
577	struct lwp *l = curlwp;
578	struct proc *p;
579	int error;
580
581	if (!l) {
582		return EFAULT;
583	}
584
585	p = l->l_proc;
586
587	/*
588	 * Stolen from physio():
589	 */
590	uvm_lwp_hold(l);
591	error = uvm_vslock(p->p_vmspace, udaddr, len, VM_PROT_WRITE);
592	if (error) {
593		uvm_lwp_rele(l);
594		return EFAULT;
595	}
596	up = (char *)vmaprange(p, (vaddr_t)udaddr, len,
597	    VM_PROT_READ | VM_PROT_WRITE);
598
599	memcpy(up, kp, len);
600	vunmaprange((vaddr_t)up, len);
601	uvm_vsunlock(p->p_vmspace, udaddr, len);
602	uvm_lwp_rele(l);
603
604	return 0;
605}
606
607/*
608 * kcopy(const void *src, void *dst, size_t len);
609 *
610 * Copy len bytes from src to dst, aborting if we encounter a fatal
611 * page fault.
612 *
613 * kcopy() _must_ save and restore the old fault handler since it is
614 * called by uiomove(), which may be in the path of servicing a non-fatal
615 * page fault.
616 */
617int
618kcopy(const void *src, void *dst, size_t len)
619{
620	struct faultbuf env, *oldfault;
621
622	oldfault = curpcb->pcb_onfault;
623	if (setfault(&env)) {
624		curpcb->pcb_onfault = oldfault;
625		return EFAULT;
626	}
627
628	memcpy(dst, src, len);
629
630	curpcb->pcb_onfault = oldfault;
631	return 0;
632}
633
634int
635badaddr(void *addr, size_t size)
636{
637
638	return badaddr_read(addr, size, NULL);
639}
640
641int
642badaddr_read(void *addr, size_t size, int *rptr)
643{
644	struct faultbuf env;
645	int x;
646
647	/* Get rid of any stale machine checks that have been waiting.  */
648	__asm volatile ("sync; isync");
649
650	if (setfault(&env)) {
651		curpcb->pcb_onfault = 0;
652		__asm volatile ("sync");
653		return 1;
654	}
655
656	__asm volatile ("sync");
657
658	switch (size) {
659	case 1:
660		x = *(volatile int8_t *)addr;
661		break;
662	case 2:
663		x = *(volatile int16_t *)addr;
664		break;
665	case 4:
666		x = *(volatile int32_t *)addr;
667		break;
668	default:
669		panic("badaddr: invalid size (%d)", size);
670	}
671
672	/* Make sure we took the machine check, if we caused one. */
673	__asm volatile ("sync; isync");
674
675	curpcb->pcb_onfault = 0;
676	__asm volatile ("sync");	/* To be sure. */
677
678	/* Use the value to avoid reorder. */
679	if (rptr)
680		*rptr = x;
681
682	return 0;
683}
684
685/*
686 * For now, this only deals with the particular unaligned access case
687 * that gcc tends to generate.  Eventually it should handle all of the
688 * possibilities that can happen on a 32-bit PowerPC in big-endian mode.
689 */
690
691static int
692fix_unaligned(struct lwp *l, struct trapframe *frame)
693{
694
695	return -1;
696}
697
698/*
699 * Start a new LWP
700 */
701void
702startlwp(arg)
703	void *arg;
704{
705	int err;
706	ucontext_t *uc = arg;
707	struct lwp *l = curlwp;
708
709	err = cpu_setmcontext(l, &uc->uc_mcontext, uc->uc_flags);
710#if DIAGNOSTIC
711	if (err) {
712		printf("Error %d from cpu_setmcontext.", err);
713	}
714#endif
715	pool_put(&lwp_uc_pool, uc);
716
717	/* Invoke MI userret code */
718	mi_userret(l);
719}
720