xref: /netbsd-src/sys/arch/powerpc/ibm4xx/trap.c (revision d20841bb642898112fe68f0ad3f7b26dddf56f07)
1 /*	$NetBSD: trap.c,v 1.20 2003/10/31 16:44:35 cl 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 1.20 2003/10/31 16:44:35 cl Exp $");
71 
72 #include "opt_altivec.h"
73 #include "opt_ddb.h"
74 #include "opt_ktrace.h"
75 #include "opt_systrace.h"
76 #include "opt_syscall_debug.h"
77 
78 #include <sys/param.h>
79 #include <sys/proc.h>
80 #include <sys/reboot.h>
81 #include <sys/syscall.h>
82 #include <sys/systm.h>
83 #include <sys/user.h>
84 #ifdef KTRACE
85 #include <sys/ktrace.h>
86 #endif
87 #include <sys/pool.h>
88 #include <sys/sa.h>
89 #include <sys/savar.h>
90 #ifdef SYSTRACE
91 #include <sys/systrace.h>
92 #endif
93 #include <sys/userret.h>
94 
95 #include <uvm/uvm_extern.h>
96 
97 #include <dev/cons.h>
98 
99 #include <machine/cpu.h>
100 #include <machine/db_machdep.h>
101 #include <machine/fpu.h>
102 #include <machine/frame.h>
103 #include <machine/pcb.h>
104 #include <machine/psl.h>
105 #include <machine/trap.h>
106 
107 #include <powerpc/spr.h>
108 #include <powerpc/ibm4xx/pmap.h>
109 #include <powerpc/ibm4xx/tlb.h>
110 #include <powerpc/fpu/fpu_extern.h>
111 
112 /* These definitions should probably be somewhere else			XXX */
113 #define	FIRSTARG	3		/* first argument is in reg 3 */
114 #define	NARGREG		8		/* 8 args are in registers */
115 #define	MOREARGS(sp)	((caddr_t)((int)(sp) + 8)) /* more args go here */
116 
117 static int fix_unaligned __P((struct lwp *l, struct trapframe *frame));
118 
119 void trap __P((struct trapframe *));	/* Called from locore / trap_subr */
120 /* Why are these not defined in a header? */
121 int badaddr __P((void *, size_t));
122 int badaddr_read __P((void *, size_t, int *));
123 int ctx_setup __P((int, int));
124 
125 #ifdef DEBUG
126 #define TDB_ALL	0x1
127 int trapdebug = /* TDB_ALL */ 0;
128 #define	DBPRINTF(x, y)	if (trapdebug & (x)) printf y
129 #else
130 #define DBPRINTF(x, y)
131 #endif
132 
133 void
134 trap(struct trapframe *frame)
135 {
136 	struct lwp *l = curlwp;
137 	struct proc *p = l ? l->l_proc : NULL;
138 	int type = frame->exc;
139 	int ftype, rv;
140 	ksiginfo_t ksi;
141 
142 	KASSERT(l == 0 || (l->l_stat == LSONPROC));
143 
144 	if (frame->srr1 & PSL_PR)
145 		type |= EXC_USER;
146 
147 	ftype = VM_PROT_READ;
148 
149 	DBPRINTF(TDB_ALL, ("trap(%x) at %lx from frame %p &frame %p\n",
150 	    type, frame->srr0, frame, &frame));
151 
152 	switch (type) {
153 	case EXC_DEBUG|EXC_USER:
154 		{
155 			int srr2, srr3;
156 
157 			__asm __volatile("mfspr %0,0x3f0" :
158 			    "=r" (rv), "=r" (srr2), "=r" (srr3) :);
159 			printf("debug reg is %x srr2 %x srr3 %x\n", rv, srr2,
160 			    srr3);
161 			/* XXX fall through or break here?! */
162 		}
163 		/*
164 		 * DEBUG intr -- probably single-step.
165 		 */
166 	case EXC_TRC|EXC_USER:
167 		frame->srr1 &= ~PSL_SE;
168 		KSI_INIT_TRAP(&ksi);
169 		ksi.ksi_signo = SIGTRAP;
170 		ksi.ksi_trap = EXC_TRC;
171 		ksi.ksi_addr = (void *)frame->srr0;
172 		KERNEL_PROC_LOCK(l);
173 		trapsignal(l, &ksi);
174 		KERNEL_PROC_UNLOCK(l);
175 		break;
176 
177 	/*
178 	 * If we could not find and install appropriate TLB entry, fall through.
179 	 */
180 
181 	case EXC_DSI:
182 		/* FALLTHROUGH */
183 	case EXC_DTMISS:
184 		{
185 			struct vm_map *map;
186 			vaddr_t va;
187 			struct faultbuf *fb = NULL;
188 
189 			KERNEL_LOCK(LK_CANRECURSE|LK_EXCLUSIVE);
190 			va = frame->dar;
191 			if (frame->tf_xtra[TF_PID] == KERNEL_PID) {
192 				map = kernel_map;
193 			} else {
194 				map = &p->p_vmspace->vm_map;
195 				if (l->l_flag & L_SA) {
196 					KDASSERT(p != NULL && p->p_sa != NULL);
197 					p->p_sa->sa_vp_faultaddr = va;
198 					l->l_flag |= L_SA_PAGEFAULT;
199 				}
200 			}
201 
202 			if (frame->tf_xtra[TF_ESR] & (ESR_DST|ESR_DIZ))
203 				ftype = VM_PROT_WRITE;
204 
205 			DBPRINTF(TDB_ALL,
206 			    ("trap(EXC_DSI) at %lx %s fault on %p esr %x\n",
207 			    frame->srr0,
208 			    (ftype & VM_PROT_WRITE) ? "write" : "read",
209 			    (void *)va, frame->tf_xtra[TF_ESR]));
210 			rv = uvm_fault(map, trunc_page(va), 0, ftype);
211 			KERNEL_UNLOCK();
212 			if (map != kernel_map)
213 				l->l_flag &= ~L_SA_PAGEFAULT;
214 			if (rv == 0)
215 				goto done;
216 			if ((fb = l->l_addr->u_pcb.pcb_onfault) != NULL) {
217 				frame->tf_xtra[TF_PID] = KERNEL_PID;
218 				frame->srr0 = fb->fb_pc;
219 				frame->srr1 |= PSL_IR; /* Re-enable IMMU */
220 				frame->fixreg[1] = fb->fb_sp;
221 				frame->fixreg[2] = fb->fb_r2;
222 				frame->fixreg[3] = 1; /* Return TRUE */
223 				frame->cr = fb->fb_cr;
224 				memcpy(&frame->fixreg[13], fb->fb_fixreg,
225 				    sizeof(fb->fb_fixreg));
226 				goto done;
227 			}
228 		}
229 		goto brain_damage;
230 
231 	case EXC_DSI|EXC_USER:
232 		/* FALLTHROUGH */
233 	case EXC_DTMISS|EXC_USER:
234 		KERNEL_PROC_LOCK(l);
235 
236 		if (frame->tf_xtra[TF_ESR] & (ESR_DST|ESR_DIZ))
237 			ftype = VM_PROT_WRITE;
238 
239 		DBPRINTF(TDB_ALL,
240 		    ("trap(EXC_DSI|EXC_USER) at %lx %s fault on %lx %x\n",
241 		    frame->srr0, (ftype & VM_PROT_WRITE) ? "write" : "read",
242 		    frame->dar, frame->tf_xtra[TF_ESR]));
243 		KASSERT(l == curlwp && (l->l_stat == LSONPROC));
244 		if (l->l_flag & L_SA) {
245 			KDASSERT(p != NULL && p->p_sa != NULL);
246 			p->p_sa->sa_vp_faultaddr = (vaddr_t)frame->dar;
247 			l->l_flag |= L_SA_PAGEFAULT;
248 		}
249 		rv = uvm_fault(&p->p_vmspace->vm_map, trunc_page(frame->dar),
250 		    0, ftype);
251 		if (rv == 0) {
252 			l->l_flag &= ~L_SA_PAGEFAULT;
253 			KERNEL_PROC_UNLOCK(l);
254 			break;
255 		}
256 		KSI_INIT_TRAP(&ksi);
257 		ksi.ksi_signo = SIGSEGV;
258 		ksi.ksi_trap = EXC_DSI;
259 		ksi.ksi_addr = (void *)frame->dar;
260 		if (rv == ENOMEM) {
261 			printf("UVM: pid %d (%s) lid %d, uid %d killed: "
262 			    "out of swap\n",
263 			    p->p_pid, p->p_comm, l->l_lid,
264 			    p->p_cred && p->p_ucred ?
265 			    p->p_ucred->cr_uid : -1);
266 			ksi.ksi_signo = SIGKILL;
267 		}
268 		trapsignal(l, &ksi);
269 		l->l_flag &= ~L_SA_PAGEFAULT;
270 		KERNEL_PROC_UNLOCK(l);
271 		break;
272 
273 	case EXC_ITMISS|EXC_USER:
274 	case EXC_ISI|EXC_USER:
275 		KERNEL_PROC_LOCK(l);
276 		if (l->l_flag & L_SA) {
277 			KDASSERT(p != NULL && p->p_sa != NULL);
278 			p->p_sa->sa_vp_faultaddr = (vaddr_t)frame->srr0;
279 			l->l_flag |= L_SA_PAGEFAULT;
280 		}
281 		ftype = VM_PROT_EXECUTE;
282 		DBPRINTF(TDB_ALL,
283 		    ("trap(EXC_ISI|EXC_USER) at %lx execute fault tf %p\n",
284 		    frame->srr0, frame));
285 		rv = uvm_fault(&p->p_vmspace->vm_map, trunc_page(frame->srr0),
286 		    0, ftype);
287 		if (rv == 0) {
288 			l->l_flag &= ~L_SA_PAGEFAULT;
289 			KERNEL_PROC_UNLOCK(l);
290 			break;
291 		}
292 		KSI_INIT_TRAP(&ksi);
293 		ksi.ksi_signo = SIGSEGV;
294 		ksi.ksi_trap = EXC_ISI;
295 		ksi.ksi_addr = (void *)frame->srr0;
296 		trapsignal(l, &ksi);
297 		l->l_flag &= ~L_SA_PAGEFAULT;
298 		KERNEL_PROC_UNLOCK(l);
299 		break;
300 
301 	case EXC_AST|EXC_USER:
302 		curcpu()->ci_astpending = 0;	/* we are about to do it */
303 		KERNEL_PROC_LOCK(l);
304 		uvmexp.softs++;
305 		if (p->p_flag & P_OWEUPC) {
306 			p->p_flag &= ~P_OWEUPC;
307 			ADDUPROF(p);
308 		}
309 		/* Check whether we are being preempted. */
310 		if (curcpu()->ci_want_resched)
311 			preempt(0);
312 		KERNEL_PROC_UNLOCK(l);
313 		break;
314 
315 
316 	case EXC_ALI|EXC_USER:
317 		KERNEL_PROC_LOCK(l);
318 		if (fix_unaligned(l, frame) != 0) {
319 			KSI_INIT_TRAP(&ksi);
320 			ksi.ksi_signo = SIGBUS;
321 			ksi.ksi_trap = EXC_ALI;
322 			ksi.ksi_addr = (void *)frame->dar;
323 			trapsignal(l, &ksi);
324 		} else
325 			frame->srr0 += 4;
326 		KERNEL_PROC_UNLOCK(l);
327 		break;
328 
329 	case EXC_PGM|EXC_USER:
330 		/*
331 		 * Illegal insn:
332 		 *
333 		 * let's try to see if it's FPU and can be emulated.
334 		 */
335 		uvmexp.traps ++;
336 		if (!(l->l_addr->u_pcb.pcb_flags & PCB_FPU)) {
337 			memset(&l->l_addr->u_pcb.pcb_fpu, 0,
338 				sizeof l->l_addr->u_pcb.pcb_fpu);
339 			l->l_addr->u_pcb.pcb_flags |= PCB_FPU;
340 		}
341 
342 		if ((rv = fpu_emulate(frame,
343 			(struct fpreg *)&l->l_addr->u_pcb.pcb_fpu))) {
344 			KSI_INIT_TRAP(&ksi);
345 			ksi.ksi_signo = rv;
346 			ksi.ksi_trap = EXC_PGM;
347 			ksi.ksi_addr = (void *)frame->srr0;
348 			KERNEL_PROC_LOCK(l);
349 			trapsignal(l, &ksi);
350 			KERNEL_PROC_UNLOCK(l);
351 		}
352 		break;
353 
354 	case EXC_MCHK:
355 		{
356 			struct faultbuf *fb;
357 
358 			if ((fb = l->l_addr->u_pcb.pcb_onfault) != NULL) {
359 				frame->tf_xtra[TF_PID] = KERNEL_PID;
360 				frame->srr0 = fb->fb_pc;
361 				frame->srr1 |= PSL_IR; /* Re-enable IMMU */
362 				frame->fixreg[1] = fb->fb_sp;
363 				frame->fixreg[2] = fb->fb_r2;
364 				frame->fixreg[3] = 1; /* Return TRUE */
365 				frame->cr = fb->fb_cr;
366 				memcpy(&frame->fixreg[13], fb->fb_fixreg,
367 				    sizeof(fb->fb_fixreg));
368 				goto done;
369 			}
370 		}
371 		goto brain_damage;
372 	default:
373  brain_damage:
374 		printf("trap type 0x%x at 0x%lx\n", type, frame->srr0);
375 #ifdef DDB
376 		if (kdb_trap(type, frame))
377 			goto done;
378 #endif
379 #ifdef TRAP_PANICWAIT
380 		printf("Press a key to panic.\n");
381 		cngetc();
382 #endif
383 		panic("trap");
384 	}
385 
386 	/* Invoke MI userret code */
387 	mi_userret(l);
388 
389 	curcpu()->ci_schedstate.spc_curpriority = l->l_priority = l->l_usrpri;
390  done:
391 	return;
392 }
393 
394 int
395 ctx_setup(int ctx, int srr1)
396 {
397 	volatile struct pmap *pm;
398 
399 	/* Update PID if we're returning to user mode. */
400 	if (srr1 & PSL_PR) {
401 		pm = curproc->p_vmspace->vm_map.pmap;
402 		if (!pm->pm_ctx) {
403 			ctx_alloc((struct pmap *)pm);
404 		}
405 		ctx = pm->pm_ctx;
406 		if (srr1 & PSL_SE) {
407 			int dbreg, mask = 0x48000000;
408 				/*
409 				 * Set the Internal Debug and
410 				 * Instruction Completion bits of
411 				 * the DBCR0 register.
412 				 *
413 				 * XXX this is also used by jtag debuggers...
414 				 */
415 			__asm __volatile("mfspr %0,0x3f2;"
416 			    "or %0,%0,%1;"
417 			    "mtspr 0x3f2,%0;" :
418 			    "=&r" (dbreg) : "r" (mask));
419 		}
420 	}
421 	else if (!ctx) {
422 		ctx = KERNEL_PID;
423 	}
424 	return (ctx);
425 }
426 
427 /*
428  * Used by copyin()/copyout()
429  */
430 extern vaddr_t vmaprange __P((struct proc *, vaddr_t, vsize_t, int));
431 extern void vunmaprange __P((vaddr_t, vsize_t));
432 static int bigcopyin __P((const void *, void *, size_t ));
433 static int bigcopyout __P((const void *, void *, size_t ));
434 
435 int
436 copyin(const void *udaddr, void *kaddr, size_t len)
437 {
438 	struct pmap *pm = curproc->p_vmspace->vm_map.pmap;
439 	int msr, pid, tmp, ctx;
440 	struct faultbuf env;
441 
442 	/* For bigger buffers use the faster copy */
443 	if (len > 256) return (bigcopyin(udaddr, kaddr, len));
444 
445 	if (setfault(&env)) {
446 		curpcb->pcb_onfault = 0;
447 		return EFAULT;
448 	}
449 
450 	if (!(ctx = pm->pm_ctx)) {
451 		/* No context -- assign it one */
452 		ctx_alloc(pm);
453 		ctx = pm->pm_ctx;
454 	}
455 
456 	asm volatile("addi %6,%6,1; mtctr %6;"	/* Set up counter */
457 		"mfmsr %0;"			/* Save MSR */
458 		"li %1,0x20; "
459 		"andc %1,%0,%1; mtmsr %1;"	/* Disable IMMU */
460 		"mfpid %1;"			/* Save old PID */
461 		"sync; isync;"
462 
463 		"1: bdz 2f;"			/* while len */
464 		"mtpid %3; sync;"		/* Load user ctx */
465 		"lbz %2,0(%4); addi %4,%4,1;"	/* Load byte */
466 		"sync; isync;"
467 		"mtpid %1;sync;"
468 		"stb %2,0(%5); dcbf 0,%5; addi %5,%5,1;" /* Store kernel byte */
469 		"sync; isync;"
470 		"b 1b;"				/* repeat */
471 
472 		"2: mtpid %1; mtmsr %0;"	/* Restore PID and MSR */
473 		"sync; isync;"
474 		: "=&r" (msr), "=&r" (pid), "=&r" (tmp)
475 		: "r" (ctx), "r" (udaddr), "r" (kaddr), "r" (len));
476 
477 	curpcb->pcb_onfault = 0;
478 	return 0;
479 }
480 
481 static int
482 bigcopyin(const void *udaddr, void *kaddr, size_t len)
483 {
484 	const char *up;
485 	char *kp = kaddr;
486 	struct lwp *l = curlwp;
487 	struct proc *p;
488 	int error;
489 
490 	if (!l) {
491 		return EFAULT;
492 	}
493 
494 	p = l->l_proc;
495 
496 	/*
497 	 * Stolen from physio():
498 	 */
499 	PHOLD(l);
500 	error = uvm_vslock(p, (caddr_t)udaddr, len, VM_PROT_READ);
501 	if (error) {
502 		PRELE(l);
503 		return EFAULT;
504 	}
505 	up = (char *)vmaprange(p, (vaddr_t)udaddr, len, VM_PROT_READ);
506 
507 	memcpy(kp, up, len);
508 	vunmaprange((vaddr_t)up, len);
509 	uvm_vsunlock(p, (caddr_t)udaddr, len);
510 	PRELE(l);
511 
512 	return 0;
513 }
514 
515 int
516 copyout(const void *kaddr, void *udaddr, size_t len)
517 {
518 	struct pmap *pm = curproc->p_vmspace->vm_map.pmap;
519 	int msr, pid, tmp, ctx;
520 	struct faultbuf env;
521 
522 	/* For big copies use more efficient routine */
523 	if (len > 256) return (bigcopyout(kaddr, udaddr, len));
524 
525 	if (setfault(&env)) {
526 		curpcb->pcb_onfault = 0;
527 		return EFAULT;
528 	}
529 
530 	if (!(ctx = pm->pm_ctx)) {
531 		/* No context -- assign it one */
532 		ctx_alloc(pm);
533 		ctx = pm->pm_ctx;
534 	}
535 
536 	asm volatile("addi %6,%6,1; mtctr %6;"	/* Set up counter */
537 		"mfmsr %0;"			/* Save MSR */
538 		"li %1,0x20; "
539 		"andc %1,%0,%1; mtmsr %1;"	/* Disable IMMU */
540 		"mfpid %1;"			/* Save old PID */
541 		"sync; isync;"
542 
543 		"1: bdz 2f;"			/* while len */
544 		"mtpid %1;sync;"
545 		"lbz %2,0(%5); addi %5,%5,1;"	/* Load kernel byte */
546 		"sync; isync;"
547 		"mtpid %3; sync;"		/* Load user ctx */
548 		"stb %2,0(%4);  dcbf 0,%4; addi %4,%4,1;" /* Store user byte */
549 		"sync; isync;"
550 		"b 1b;"				/* repeat */
551 
552 		"2: mtpid %1; mtmsr %0;"	/* Restore PID and MSR */
553 		"sync; isync;"
554 		: "=&r" (msr), "=&r" (pid), "=&r" (tmp)
555 		: "r" (ctx), "r" (udaddr), "r" (kaddr), "r" (len));
556 
557 	curpcb->pcb_onfault = 0;
558 	return 0;
559 }
560 
561 static int
562 bigcopyout(const void *kaddr, void *udaddr, size_t len)
563 {
564 	char *up;
565 	const char *kp = (char *)kaddr;
566 	struct lwp *l = curlwp;
567 	struct proc *p;
568 	int error;
569 
570 	if (!l) {
571 		return EFAULT;
572 	}
573 
574 	p = l->l_proc;
575 
576 	/*
577 	 * Stolen from physio():
578 	 */
579 	PHOLD(l);
580 	error = uvm_vslock(p, udaddr, len, VM_PROT_WRITE);
581 	if (error) {
582 		PRELE(l);
583 		return EFAULT;
584 	}
585 	up = (char *)vmaprange(p, (vaddr_t)udaddr, len,
586 	    VM_PROT_READ | VM_PROT_WRITE);
587 
588 	memcpy(up, kp, len);
589 	vunmaprange((vaddr_t)up, len);
590 	uvm_vsunlock(p, udaddr, len);
591 	PRELE(l);
592 
593 	return 0;
594 }
595 
596 /*
597  * kcopy(const void *src, void *dst, size_t len);
598  *
599  * Copy len bytes from src to dst, aborting if we encounter a fatal
600  * page fault.
601  *
602  * kcopy() _must_ save and restore the old fault handler since it is
603  * called by uiomove(), which may be in the path of servicing a non-fatal
604  * page fault.
605  */
606 int
607 kcopy(const void *src, void *dst, size_t len)
608 {
609 	struct faultbuf env, *oldfault;
610 
611 	oldfault = curpcb->pcb_onfault;
612 	if (setfault(&env)) {
613 		curpcb->pcb_onfault = oldfault;
614 		return EFAULT;
615 	}
616 
617 	memcpy(dst, src, len);
618 
619 	curpcb->pcb_onfault = oldfault;
620 	return 0;
621 }
622 
623 int
624 badaddr(void *addr, size_t size)
625 {
626 
627 	return badaddr_read(addr, size, NULL);
628 }
629 
630 int
631 badaddr_read(void *addr, size_t size, int *rptr)
632 {
633 	struct faultbuf env;
634 	int x;
635 
636 	/* Get rid of any stale machine checks that have been waiting.  */
637 	__asm __volatile ("sync; isync");
638 
639 	if (setfault(&env)) {
640 		curpcb->pcb_onfault = 0;
641 		__asm __volatile ("sync");
642 		return 1;
643 	}
644 
645 	__asm __volatile ("sync");
646 
647 	switch (size) {
648 	case 1:
649 		x = *(volatile int8_t *)addr;
650 		break;
651 	case 2:
652 		x = *(volatile int16_t *)addr;
653 		break;
654 	case 4:
655 		x = *(volatile int32_t *)addr;
656 		break;
657 	default:
658 		panic("badaddr: invalid size (%d)", size);
659 	}
660 
661 	/* Make sure we took the machine check, if we caused one. */
662 	__asm __volatile ("sync; isync");
663 
664 	curpcb->pcb_onfault = 0;
665 	__asm __volatile ("sync");	/* To be sure. */
666 
667 	/* Use the value to avoid reorder. */
668 	if (rptr)
669 		*rptr = x;
670 
671 	return 0;
672 }
673 
674 /*
675  * For now, this only deals with the particular unaligned access case
676  * that gcc tends to generate.  Eventually it should handle all of the
677  * possibilities that can happen on a 32-bit PowerPC in big-endian mode.
678  */
679 
680 static int
681 fix_unaligned(struct lwp *l, struct trapframe *frame)
682 {
683 
684 	return -1;
685 }
686 
687 /*
688  * Start a new LWP
689  */
690 void
691 startlwp(arg)
692 	void *arg;
693 {
694 	int err;
695 	ucontext_t *uc = arg;
696 	struct lwp *l = curlwp;
697 
698 	err = cpu_setmcontext(l, &uc->uc_mcontext, uc->uc_flags);
699 #if DIAGNOSTIC
700 	if (err) {
701 		printf("Error %d from cpu_setmcontext.", err);
702 	}
703 #endif
704 	pool_put(&lwp_uc_pool, uc);
705 
706 	upcallret(l);
707 }
708 
709 /*
710  * XXX This is a terrible name.
711  */
712 void
713 upcallret(l)
714 	struct lwp *l;
715 {
716 
717 	/* Invoke MI userret code */
718 	mi_userret(l);
719 
720 	curcpu()->ci_schedstate.spc_curpriority = l->l_priority = l->l_usrpri;
721 }
722