xref: /netbsd-src/sys/arch/powerpc/ibm4xx/trap.c (revision fad4c9f71477ae11cea2ee75ec82151ac770a534)
1 /*	$NetBSD: trap.c,v 1.34 2006/05/15 09:21:21 yamt 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 1.34 2006/05/15 09:21:21 yamt Exp $");
71 
72 #include "opt_altivec.h"
73 #include "opt_ddb.h"
74 
75 #include <sys/param.h>
76 #include <sys/proc.h>
77 #include <sys/reboot.h>
78 #include <sys/syscall.h>
79 #include <sys/systm.h>
80 #include <sys/user.h>
81 #include <sys/pool.h>
82 #include <sys/sa.h>
83 #include <sys/savar.h>
84 #include <sys/userret.h>
85 #include <sys/kauth.h>
86 
87 #include <uvm/uvm_extern.h>
88 
89 #include <dev/cons.h>
90 
91 #include <machine/cpu.h>
92 #include <machine/db_machdep.h>
93 #include <machine/fpu.h>
94 #include <machine/frame.h>
95 #include <machine/pcb.h>
96 #include <machine/psl.h>
97 #include <machine/trap.h>
98 
99 #include <powerpc/spr.h>
100 #include <powerpc/ibm4xx/pmap.h>
101 #include <powerpc/ibm4xx/tlb.h>
102 #include <powerpc/fpu/fpu_extern.h>
103 
104 /* These definitions should probably be somewhere else			XXX */
105 #define	FIRSTARG	3		/* first argument is in reg 3 */
106 #define	NARGREG		8		/* 8 args are in registers */
107 #define	MOREARGS(sp)	((caddr_t)((int)(sp) + 8)) /* more args go here */
108 
109 static int fix_unaligned __P((struct lwp *l, struct trapframe *frame));
110 
111 void trap __P((struct trapframe *));	/* Called from locore / trap_subr */
112 /* Why are these not defined in a header? */
113 int badaddr __P((void *, size_t));
114 int badaddr_read __P((void *, size_t, int *));
115 int ctx_setup __P((int, int));
116 
117 #ifdef DEBUG
118 #define TDB_ALL	0x1
119 int trapdebug = /* TDB_ALL */ 0;
120 #define	DBPRINTF(x, y)	if (trapdebug & (x)) printf y
121 #else
122 #define DBPRINTF(x, y)
123 #endif
124 
125 void
126 trap(struct trapframe *frame)
127 {
128 	struct lwp *l = curlwp;
129 	struct proc *p = l ? l->l_proc : NULL;
130 	int type = frame->exc;
131 	int ftype, rv;
132 	ksiginfo_t ksi;
133 
134 	KASSERT(l == 0 || (l->l_stat == LSONPROC));
135 
136 	if (frame->srr1 & PSL_PR)
137 		type |= EXC_USER;
138 
139 	ftype = VM_PROT_READ;
140 
141 	DBPRINTF(TDB_ALL, ("trap(%x) at %lx from frame %p &frame %p\n",
142 	    type, frame->srr0, frame, &frame));
143 
144 	switch (type) {
145 	case EXC_DEBUG|EXC_USER:
146 		{
147 			int srr2, srr3;
148 
149 			__asm volatile("mfspr %0,0x3f0" :
150 			    "=r" (rv), "=r" (srr2), "=r" (srr3) :);
151 			printf("debug reg is %x srr2 %x srr3 %x\n", rv, srr2,
152 			    srr3);
153 			/* XXX fall through or break here?! */
154 		}
155 		/*
156 		 * DEBUG intr -- probably single-step.
157 		 */
158 	case EXC_TRC|EXC_USER:
159 		frame->srr1 &= ~PSL_SE;
160 		KSI_INIT_TRAP(&ksi);
161 		ksi.ksi_signo = SIGTRAP;
162 		ksi.ksi_trap = EXC_TRC;
163 		ksi.ksi_addr = (void *)frame->srr0;
164 		KERNEL_PROC_LOCK(l);
165 		trapsignal(l, &ksi);
166 		KERNEL_PROC_UNLOCK(l);
167 		break;
168 
169 	/*
170 	 * If we could not find and install appropriate TLB entry, fall through.
171 	 */
172 
173 	case EXC_DSI:
174 		/* FALLTHROUGH */
175 	case EXC_DTMISS:
176 		{
177 			struct vm_map *map;
178 			vaddr_t va;
179 			struct faultbuf *fb = NULL;
180 
181 			KERNEL_LOCK(LK_CANRECURSE|LK_EXCLUSIVE);
182 			va = frame->dar;
183 			if (frame->tf_xtra[TF_PID] == KERNEL_PID) {
184 				map = kernel_map;
185 			} else {
186 				map = &p->p_vmspace->vm_map;
187 				if (l->l_flag & L_SA) {
188 					l->l_savp->savp_faultaddr = va;
189 					l->l_flag |= L_SA_PAGEFAULT;
190 				}
191 			}
192 
193 			if (frame->tf_xtra[TF_ESR] & (ESR_DST|ESR_DIZ))
194 				ftype = VM_PROT_WRITE;
195 
196 			DBPRINTF(TDB_ALL,
197 			    ("trap(EXC_DSI) at %lx %s fault on %p esr %x\n",
198 			    frame->srr0,
199 			    (ftype & VM_PROT_WRITE) ? "write" : "read",
200 			    (void *)va, frame->tf_xtra[TF_ESR]));
201 			rv = uvm_fault(map, trunc_page(va), ftype);
202 			KERNEL_UNLOCK();
203 			if (map != kernel_map)
204 				l->l_flag &= ~L_SA_PAGEFAULT;
205 			if (rv == 0)
206 				goto done;
207 			if ((fb = l->l_addr->u_pcb.pcb_onfault) != NULL) {
208 				frame->tf_xtra[TF_PID] = KERNEL_PID;
209 				frame->srr0 = fb->fb_pc;
210 				frame->srr1 |= PSL_IR; /* Re-enable IMMU */
211 				frame->fixreg[1] = fb->fb_sp;
212 				frame->fixreg[2] = fb->fb_r2;
213 				frame->fixreg[3] = 1; /* Return TRUE */
214 				frame->cr = fb->fb_cr;
215 				memcpy(&frame->fixreg[13], fb->fb_fixreg,
216 				    sizeof(fb->fb_fixreg));
217 				goto done;
218 			}
219 		}
220 		goto brain_damage;
221 
222 	case EXC_DSI|EXC_USER:
223 		/* FALLTHROUGH */
224 	case EXC_DTMISS|EXC_USER:
225 		KERNEL_PROC_LOCK(l);
226 
227 		if (frame->tf_xtra[TF_ESR] & (ESR_DST|ESR_DIZ))
228 			ftype = VM_PROT_WRITE;
229 
230 		DBPRINTF(TDB_ALL,
231 		    ("trap(EXC_DSI|EXC_USER) at %lx %s fault on %lx %x\n",
232 		    frame->srr0, (ftype & VM_PROT_WRITE) ? "write" : "read",
233 		    frame->dar, frame->tf_xtra[TF_ESR]));
234 		KASSERT(l == curlwp && (l->l_stat == LSONPROC));
235 		if (l->l_flag & L_SA) {
236 			l->l_savp->savp_faultaddr = (vaddr_t)frame->dar;
237 			l->l_flag |= L_SA_PAGEFAULT;
238 		}
239 		rv = uvm_fault(&p->p_vmspace->vm_map, trunc_page(frame->dar),
240 		    ftype);
241 		if (rv == 0) {
242 			l->l_flag &= ~L_SA_PAGEFAULT;
243 			KERNEL_PROC_UNLOCK(l);
244 			break;
245 		}
246 		KSI_INIT_TRAP(&ksi);
247 		ksi.ksi_signo = SIGSEGV;
248 		ksi.ksi_trap = EXC_DSI;
249 		ksi.ksi_addr = (void *)frame->dar;
250 		if (rv == ENOMEM) {
251 			printf("UVM: pid %d (%s) lid %d, uid %d killed: "
252 			    "out of swap\n",
253 			    p->p_pid, p->p_comm, l->l_lid,
254 			    p->p_cred ?
255 			    kauth_cred_geteuid(p->p_cred) : -1);
256 			ksi.ksi_signo = SIGKILL;
257 		}
258 		trapsignal(l, &ksi);
259 		l->l_flag &= ~L_SA_PAGEFAULT;
260 		KERNEL_PROC_UNLOCK(l);
261 		break;
262 
263 	case EXC_ITMISS|EXC_USER:
264 	case EXC_ISI|EXC_USER:
265 		KERNEL_PROC_LOCK(l);
266 		if (l->l_flag & L_SA) {
267 			l->l_savp->savp_faultaddr = (vaddr_t)frame->srr0;
268 			l->l_flag |= L_SA_PAGEFAULT;
269 		}
270 		ftype = VM_PROT_EXECUTE;
271 		DBPRINTF(TDB_ALL,
272 		    ("trap(EXC_ISI|EXC_USER) at %lx execute fault tf %p\n",
273 		    frame->srr0, frame));
274 		rv = uvm_fault(&p->p_vmspace->vm_map, trunc_page(frame->srr0),
275 		    ftype);
276 		if (rv == 0) {
277 			l->l_flag &= ~L_SA_PAGEFAULT;
278 			KERNEL_PROC_UNLOCK(l);
279 			break;
280 		}
281 		KSI_INIT_TRAP(&ksi);
282 		ksi.ksi_signo = SIGSEGV;
283 		ksi.ksi_trap = EXC_ISI;
284 		ksi.ksi_addr = (void *)frame->srr0;
285 		ksi.ksi_code = (rv == EACCES ? SEGV_ACCERR : SEGV_MAPERR);
286 		trapsignal(l, &ksi);
287 		l->l_flag &= ~L_SA_PAGEFAULT;
288 		KERNEL_PROC_UNLOCK(l);
289 		break;
290 
291 	case EXC_AST|EXC_USER:
292 		curcpu()->ci_astpending = 0;	/* we are about to do it */
293 		KERNEL_PROC_LOCK(l);
294 		uvmexp.softs++;
295 		if (p->p_flag & P_OWEUPC) {
296 			p->p_flag &= ~P_OWEUPC;
297 			ADDUPROF(p);
298 		}
299 		/* Check whether we are being preempted. */
300 		if (curcpu()->ci_want_resched)
301 			preempt(0);
302 		KERNEL_PROC_UNLOCK(l);
303 		break;
304 
305 
306 	case EXC_ALI|EXC_USER:
307 		KERNEL_PROC_LOCK(l);
308 		if (fix_unaligned(l, frame) != 0) {
309 			KSI_INIT_TRAP(&ksi);
310 			ksi.ksi_signo = SIGBUS;
311 			ksi.ksi_trap = EXC_ALI;
312 			ksi.ksi_addr = (void *)frame->dar;
313 			trapsignal(l, &ksi);
314 		} else
315 			frame->srr0 += 4;
316 		KERNEL_PROC_UNLOCK(l);
317 		break;
318 
319 	case EXC_PGM|EXC_USER:
320 		/*
321 		 * Illegal insn:
322 		 *
323 		 * let's try to see if it's FPU and can be emulated.
324 		 */
325 		uvmexp.traps++;
326 		if (!(l->l_addr->u_pcb.pcb_flags & PCB_FPU)) {
327 			memset(&l->l_addr->u_pcb.pcb_fpu, 0,
328 				sizeof l->l_addr->u_pcb.pcb_fpu);
329 			l->l_addr->u_pcb.pcb_flags |= PCB_FPU;
330 		}
331 
332 		if ((rv = fpu_emulate(frame,
333 			(struct fpreg *)&l->l_addr->u_pcb.pcb_fpu))) {
334 			KSI_INIT_TRAP(&ksi);
335 			ksi.ksi_signo = rv;
336 			ksi.ksi_trap = EXC_PGM;
337 			ksi.ksi_addr = (void *)frame->srr0;
338 			KERNEL_PROC_LOCK(l);
339 			trapsignal(l, &ksi);
340 			KERNEL_PROC_UNLOCK(l);
341 		}
342 		break;
343 
344 	case EXC_MCHK:
345 		{
346 			struct faultbuf *fb;
347 
348 			if ((fb = l->l_addr->u_pcb.pcb_onfault) != NULL) {
349 				frame->tf_xtra[TF_PID] = KERNEL_PID;
350 				frame->srr0 = fb->fb_pc;
351 				frame->srr1 |= PSL_IR; /* Re-enable IMMU */
352 				frame->fixreg[1] = fb->fb_sp;
353 				frame->fixreg[2] = fb->fb_r2;
354 				frame->fixreg[3] = 1; /* Return TRUE */
355 				frame->cr = fb->fb_cr;
356 				memcpy(&frame->fixreg[13], fb->fb_fixreg,
357 				    sizeof(fb->fb_fixreg));
358 				goto done;
359 			}
360 		}
361 		goto brain_damage;
362 	default:
363  brain_damage:
364 		printf("trap type 0x%x at 0x%lx\n", type, frame->srr0);
365 #ifdef DDB
366 		if (kdb_trap(type, frame))
367 			goto done;
368 #endif
369 #ifdef TRAP_PANICWAIT
370 		printf("Press a key to panic.\n");
371 		cngetc();
372 #endif
373 		panic("trap");
374 	}
375 
376 	/* Invoke MI userret code */
377 	mi_userret(l);
378 
379 	curcpu()->ci_schedstate.spc_curpriority = l->l_priority = l->l_usrpri;
380  done:
381 	return;
382 }
383 
384 int
385 ctx_setup(int ctx, int srr1)
386 {
387 	volatile struct pmap *pm;
388 
389 	/* Update PID if we're returning to user mode. */
390 	if (srr1 & PSL_PR) {
391 		pm = curproc->p_vmspace->vm_map.pmap;
392 		if (!pm->pm_ctx) {
393 			ctx_alloc(__UNVOLATILE(pm));
394 		}
395 		ctx = pm->pm_ctx;
396 		if (srr1 & PSL_SE) {
397 			int dbreg, mask = 0x48000000;
398 				/*
399 				 * Set the Internal Debug and
400 				 * Instruction Completion bits of
401 				 * the DBCR0 register.
402 				 *
403 				 * XXX this is also used by jtag debuggers...
404 				 */
405 			__asm volatile("mfspr %0,0x3f2;"
406 			    "or %0,%0,%1;"
407 			    "mtspr 0x3f2,%0;" :
408 			    "=&r" (dbreg) : "r" (mask));
409 		}
410 	}
411 	else if (!ctx) {
412 		ctx = KERNEL_PID;
413 	}
414 	return (ctx);
415 }
416 
417 /*
418  * Used by copyin()/copyout()
419  */
420 extern vaddr_t vmaprange __P((struct proc *, vaddr_t, vsize_t, int));
421 extern void vunmaprange __P((vaddr_t, vsize_t));
422 static int bigcopyin __P((const void *, void *, size_t ));
423 static int bigcopyout __P((const void *, void *, size_t ));
424 
425 int
426 copyin(const void *udaddr, void *kaddr, size_t len)
427 {
428 	struct pmap *pm = curproc->p_vmspace->vm_map.pmap;
429 	int msr, pid, tmp, ctx;
430 	struct faultbuf env;
431 
432 	/* For bigger buffers use the faster copy */
433 	if (len > 256)
434 		return (bigcopyin(udaddr, kaddr, len));
435 
436 	if (setfault(&env)) {
437 		curpcb->pcb_onfault = 0;
438 		return EFAULT;
439 	}
440 
441 	if (!(ctx = pm->pm_ctx)) {
442 		/* No context -- assign it one */
443 		ctx_alloc(pm);
444 		ctx = pm->pm_ctx;
445 	}
446 
447 	__asm volatile("addi %6,%6,1; mtctr %6;"	/* Set up counter */
448 		"mfmsr %0;"			/* Save MSR */
449 		"li %1,0x20; "
450 		"andc %1,%0,%1; mtmsr %1;"	/* Disable IMMU */
451 		"mfpid %1;"			/* Save old PID */
452 		"sync; isync;"
453 
454 		"1: bdz 2f;"			/* while len */
455 		"mtpid %3; sync;"		/* Load user ctx */
456 		"lbz %2,0(%4); addi %4,%4,1;"	/* Load byte */
457 		"sync; isync;"
458 		"mtpid %1;sync;"
459 		"stb %2,0(%5); dcbf 0,%5; addi %5,%5,1;" /* Store kernel byte */
460 		"sync; isync;"
461 		"b 1b;"				/* repeat */
462 
463 		"2: mtpid %1; mtmsr %0;"	/* Restore PID and MSR */
464 		"sync; isync;"
465 		: "=&r" (msr), "=&r" (pid), "=&r" (tmp)
466 		: "r" (ctx), "b" (udaddr), "b" (kaddr), "b" (len));
467 
468 	curpcb->pcb_onfault = 0;
469 	return 0;
470 }
471 
472 static int
473 bigcopyin(const void *udaddr, void *kaddr, size_t len)
474 {
475 	const char *up;
476 	char *kp = kaddr;
477 	struct lwp *l = curlwp;
478 	struct proc *p;
479 	int error;
480 
481 	if (!l) {
482 		return EFAULT;
483 	}
484 
485 	p = l->l_proc;
486 
487 	/*
488 	 * Stolen from physio():
489 	 */
490 	PHOLD(l);
491 	error = uvm_vslock(p, __UNCONST(udaddr), len, VM_PROT_READ);
492 	if (error) {
493 		PRELE(l);
494 		return EFAULT;
495 	}
496 	up = (char *)vmaprange(p, (vaddr_t)udaddr, len, VM_PROT_READ);
497 
498 	memcpy(kp, up, len);
499 	vunmaprange((vaddr_t)up, len);
500 	uvm_vsunlock(p, __UNCONST(udaddr), len);
501 	PRELE(l);
502 
503 	return 0;
504 }
505 
506 int
507 copyout(const void *kaddr, void *udaddr, size_t len)
508 {
509 	struct pmap *pm = curproc->p_vmspace->vm_map.pmap;
510 	int msr, pid, tmp, ctx;
511 	struct faultbuf env;
512 
513 	/* For big copies use more efficient routine */
514 	if (len > 256)
515 		return (bigcopyout(kaddr, udaddr, len));
516 
517 	if (setfault(&env)) {
518 		curpcb->pcb_onfault = 0;
519 		return EFAULT;
520 	}
521 
522 	if (!(ctx = pm->pm_ctx)) {
523 		/* No context -- assign it one */
524 		ctx_alloc(pm);
525 		ctx = pm->pm_ctx;
526 	}
527 
528 	__asm volatile("addi %6,%6,1; mtctr %6;"	/* Set up counter */
529 		"mfmsr %0;"			/* Save MSR */
530 		"li %1,0x20; "
531 		"andc %1,%0,%1; mtmsr %1;"	/* Disable IMMU */
532 		"mfpid %1;"			/* Save old PID */
533 		"sync; isync;"
534 
535 		"1: bdz 2f;"			/* while len */
536 		"mtpid %1;sync;"
537 		"lbz %2,0(%5); addi %5,%5,1;"	/* Load kernel byte */
538 		"sync; isync;"
539 		"mtpid %3; sync;"		/* Load user ctx */
540 		"stb %2,0(%4);  dcbf 0,%4; addi %4,%4,1;" /* Store user byte */
541 		"sync; isync;"
542 		"b 1b;"				/* repeat */
543 
544 		"2: mtpid %1; mtmsr %0;"	/* Restore PID and MSR */
545 		"sync; isync;"
546 		: "=&r" (msr), "=&r" (pid), "=&r" (tmp)
547 		: "r" (ctx), "b" (udaddr), "b" (kaddr), "b" (len));
548 
549 	curpcb->pcb_onfault = 0;
550 	return 0;
551 }
552 
553 static int
554 bigcopyout(const void *kaddr, void *udaddr, size_t len)
555 {
556 	char *up;
557 	const char *kp = (const char *)kaddr;
558 	struct lwp *l = curlwp;
559 	struct proc *p;
560 	int error;
561 
562 	if (!l) {
563 		return EFAULT;
564 	}
565 
566 	p = l->l_proc;
567 
568 	/*
569 	 * Stolen from physio():
570 	 */
571 	PHOLD(l);
572 	error = uvm_vslock(p, udaddr, len, VM_PROT_WRITE);
573 	if (error) {
574 		PRELE(l);
575 		return EFAULT;
576 	}
577 	up = (char *)vmaprange(p, (vaddr_t)udaddr, len,
578 	    VM_PROT_READ | VM_PROT_WRITE);
579 
580 	memcpy(up, kp, len);
581 	vunmaprange((vaddr_t)up, len);
582 	uvm_vsunlock(p, udaddr, len);
583 	PRELE(l);
584 
585 	return 0;
586 }
587 
588 /*
589  * kcopy(const void *src, void *dst, size_t len);
590  *
591  * Copy len bytes from src to dst, aborting if we encounter a fatal
592  * page fault.
593  *
594  * kcopy() _must_ save and restore the old fault handler since it is
595  * called by uiomove(), which may be in the path of servicing a non-fatal
596  * page fault.
597  */
598 int
599 kcopy(const void *src, void *dst, size_t len)
600 {
601 	struct faultbuf env, *oldfault;
602 
603 	oldfault = curpcb->pcb_onfault;
604 	if (setfault(&env)) {
605 		curpcb->pcb_onfault = oldfault;
606 		return EFAULT;
607 	}
608 
609 	memcpy(dst, src, len);
610 
611 	curpcb->pcb_onfault = oldfault;
612 	return 0;
613 }
614 
615 int
616 badaddr(void *addr, size_t size)
617 {
618 
619 	return badaddr_read(addr, size, NULL);
620 }
621 
622 int
623 badaddr_read(void *addr, size_t size, int *rptr)
624 {
625 	struct faultbuf env;
626 	int x;
627 
628 	/* Get rid of any stale machine checks that have been waiting.  */
629 	__asm volatile ("sync; isync");
630 
631 	if (setfault(&env)) {
632 		curpcb->pcb_onfault = 0;
633 		__asm volatile ("sync");
634 		return 1;
635 	}
636 
637 	__asm volatile ("sync");
638 
639 	switch (size) {
640 	case 1:
641 		x = *(volatile int8_t *)addr;
642 		break;
643 	case 2:
644 		x = *(volatile int16_t *)addr;
645 		break;
646 	case 4:
647 		x = *(volatile int32_t *)addr;
648 		break;
649 	default:
650 		panic("badaddr: invalid size (%d)", size);
651 	}
652 
653 	/* Make sure we took the machine check, if we caused one. */
654 	__asm volatile ("sync; isync");
655 
656 	curpcb->pcb_onfault = 0;
657 	__asm volatile ("sync");	/* To be sure. */
658 
659 	/* Use the value to avoid reorder. */
660 	if (rptr)
661 		*rptr = x;
662 
663 	return 0;
664 }
665 
666 /*
667  * For now, this only deals with the particular unaligned access case
668  * that gcc tends to generate.  Eventually it should handle all of the
669  * possibilities that can happen on a 32-bit PowerPC in big-endian mode.
670  */
671 
672 static int
673 fix_unaligned(struct lwp *l, struct trapframe *frame)
674 {
675 
676 	return -1;
677 }
678 
679 /*
680  * Start a new LWP
681  */
682 void
683 startlwp(arg)
684 	void *arg;
685 {
686 	int err;
687 	ucontext_t *uc = arg;
688 	struct lwp *l = curlwp;
689 
690 	err = cpu_setmcontext(l, &uc->uc_mcontext, uc->uc_flags);
691 #if DIAGNOSTIC
692 	if (err) {
693 		printf("Error %d from cpu_setmcontext.", err);
694 	}
695 #endif
696 	pool_put(&lwp_uc_pool, uc);
697 
698 	upcallret(l);
699 }
700 
701 /*
702  * XXX This is a terrible name.
703  */
704 void
705 upcallret(l)
706 	struct lwp *l;
707 {
708 
709 	/* Invoke MI userret code */
710 	mi_userret(l);
711 
712 	curcpu()->ci_schedstate.spc_curpriority = l->l_priority = l->l_usrpri;
713 }
714