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trap.c revision 1.2.6.3
      1 /*	$NetBSD: trap.c,v 1.2.6.3 2001/12/17 21:34:44 nathanw 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 #include <sys/lwp.h>
     82 #include <sys/pool.h>
     83 #include <sys/sa.h>
     84 #include <sys/savar.h>
     85 
     86 #include <uvm/uvm_extern.h>
     87 
     88 #include <dev/cons.h>
     89 
     90 #include <machine/cpu.h>
     91 #include <machine/db_machdep.h>
     92 #include <machine/fpu.h>
     93 #include <machine/frame.h>
     94 #include <machine/pcb.h>
     95 #include <machine/psl.h>
     96 #include <machine/trap.h>
     97 
     98 #include <powerpc/spr.h>
     99 #include <powerpc/ibm4xx/pmap.h>
    100 #include <powerpc/ibm4xx/tlb.h>
    101 #include <powerpc/fpu/fpu_extern.h>
    102 
    103 /* These definitions should probably be somewhere else			XXX */
    104 #define	FIRSTARG	3		/* first argument is in reg 3 */
    105 #define	NARGREG		8		/* 8 args are in registers */
    106 #define	MOREARGS(sp)	((caddr_t)((int)(sp) + 8)) /* more args go here */
    107 
    108 #ifndef MULTIPROCESSOR
    109 volatile int astpending;
    110 volatile int want_resched;
    111 #endif
    112 
    113 void *syscall = NULL;	/* XXX dummy symbol for emul_netbsd */
    114 
    115 static int fix_unaligned __P((struct lwp *p, struct trapframe *frame));
    116 
    117 void trap __P((struct trapframe *));	/* Called from locore / trap_subr */
    118 int setfault __P((faultbuf));	/* defined in locore.S */
    119 /* Why are these not defined in a header? */
    120 int badaddr __P((void *, size_t));
    121 int badaddr_read __P((void *, size_t, int *));
    122 int ctx_setup __P((int, int));
    123 
    124 #ifdef DEBUG
    125 #define TDB_ALL	0x1
    126 int trapdebug = /* TDB_ALL */ 0;
    127 #define	DBPRINTF(x, y)	if (trapdebug & (x)) printf y
    128 #else
    129 #define DBPRINTF(x, y)
    130 #endif
    131 
    132 void
    133 trap(struct trapframe *frame)
    134 {
    135 	struct lwp *l = curproc;
    136 	struct proc *p = l ? l->l_proc : NULL;
    137 	int type = frame->exc;
    138 	int ftype, rv;
    139 
    140 	KASSERT(l == 0 || (l->l_stat == LSONPROC));
    141 
    142 	if (frame->srr1 & PSL_PR)
    143 		type |= EXC_USER;
    144 
    145 	ftype = VM_PROT_READ;
    146 
    147 DBPRINTF(TDB_ALL, ("trap(%x) at %x from frame %p &frame %p\n",
    148 	type, frame->srr0, frame, &frame));
    149 
    150 	switch (type) {
    151 	case EXC_DEBUG|EXC_USER:
    152 {
    153 	int srr2, srr3;
    154 __asm __volatile("mfspr %0,0x3f0" : "=r" (rv), "=r" (srr2), "=r" (srr3) :);
    155 printf("debug reg is %x srr2 %x srr3 %x\n", rv, srr2, srr3);
    156 }
    157 		/*
    158 		 * DEBUG intr -- probably single-step.
    159 		 */
    160 	case EXC_TRC|EXC_USER:
    161 		KERNEL_PROC_LOCK(l);
    162 		frame->srr1 &= ~PSL_SE;
    163 		trapsignal(l, SIGTRAP, EXC_TRC);
    164 		KERNEL_PROC_UNLOCK(l);
    165 		break;
    166 
    167 	  /* If we could not find and install appropriate TLB entry, fall through */
    168 
    169 	case EXC_DSI:
    170 		/* FALLTHROUGH */
    171 	case EXC_DTMISS:
    172 		{
    173 			struct vm_map *map;
    174 			vaddr_t va;
    175 			faultbuf *fb = NULL;
    176 
    177 			KERNEL_LOCK(LK_CANRECURSE|LK_EXCLUSIVE);
    178 			va = frame->dear;
    179 			if (frame->pid == KERNEL_PID) {
    180 				map = kernel_map;
    181 			} else {
    182 				map = &p->p_vmspace->vm_map;
    183 			}
    184 
    185 			if (frame->esr & (ESR_DST|ESR_DIZ))
    186 				ftype = VM_PROT_READ | VM_PROT_WRITE;
    187 
    188 DBPRINTF(TDB_ALL, ("trap(EXC_DSI) at %x %s fault on %p esr %x\n",
    189 frame->srr0, (ftype&VM_PROT_WRITE) ? "write" : "read", (void *)va, frame->esr));
    190 			rv = uvm_fault(map, trunc_page(va), 0, ftype);
    191 			KERNEL_UNLOCK();
    192 			if (rv == 0)
    193 				goto done;
    194 			if ((fb = l->l_addr->u_pcb.pcb_onfault) != NULL) {
    195 				frame->pid = KERNEL_PID;
    196 				frame->srr0 = (*fb)[0];
    197 				frame->srr1 |= PSL_IR; /* Re-enable IMMU */
    198 				frame->fixreg[1] = (*fb)[1];
    199 				frame->fixreg[2] = (*fb)[2];
    200 				frame->fixreg[3] = 1; /* Return TRUE */
    201 				frame->cr = (*fb)[3];
    202 				memcpy(&frame->fixreg[13], &(*fb)[4],
    203 				      19 * sizeof(register_t));
    204 				goto done;
    205 			}
    206 		}
    207 		goto brain_damage;
    208 
    209 	case EXC_DSI|EXC_USER:
    210 		/* FALLTHROUGH */
    211 	case EXC_DTMISS|EXC_USER:
    212 		KERNEL_PROC_LOCK(l);
    213 
    214 		if (frame->esr & (ESR_DST|ESR_DIZ))
    215 			ftype = VM_PROT_READ | VM_PROT_WRITE;
    216 
    217 DBPRINTF(TDB_ALL, ("trap(EXC_DSI|EXC_USER) at %x %s fault on %x %x\n",
    218 frame->srr0, (ftype&VM_PROT_WRITE) ? "write" : "read", frame->dear, frame->esr));
    219 KASSERT(l == curproc && (l->l_stat == LSONPROC));
    220 		rv = uvm_fault(&p->p_vmspace->vm_map,
    221 			       trunc_page(frame->dear), 0, ftype);
    222 		if (rv == 0) {
    223 		  KERNEL_PROC_UNLOCK(l);
    224 		  break;
    225 		}
    226 		if (rv == ENOMEM) {
    227 			printf("UVM: pid %d (%s) lid %d, uid %d killed: "
    228 			       "out of swap\n",
    229 			       p->p_pid, p->p_comm, l->l_lid,
    230 			       p->p_cred && p->p_ucred ?
    231 			       p->p_ucred->cr_uid : -1);
    232 			trapsignal(l, SIGKILL, EXC_DSI);
    233 		} else {
    234 			trapsignal(l, SIGSEGV, EXC_DSI);
    235 		}
    236 		KERNEL_PROC_UNLOCK(l);
    237 		break;
    238 	case EXC_ITMISS|EXC_USER:
    239 	case EXC_ISI|EXC_USER:
    240 		KERNEL_PROC_LOCK(l);
    241 		ftype = VM_PROT_READ | VM_PROT_EXECUTE;
    242 DBPRINTF(TDB_ALL, ("trap(EXC_ISI|EXC_USER) at %x %s fault on %x tf %p\n",
    243 frame->srr0, (ftype&VM_PROT_WRITE) ? "write" : "read", frame->srr0, frame));
    244 		rv = uvm_fault(&p->p_vmspace->vm_map, trunc_page(frame->srr0), 0, ftype);
    245 		if (rv == 0) {
    246 		  KERNEL_PROC_UNLOCK(l);
    247 		  break;
    248 		}
    249 		trapsignal(l, SIGSEGV, EXC_ISI);
    250 		KERNEL_PROC_UNLOCK(l);
    251 		break;
    252 	case EXC_SC|EXC_USER:
    253 		{
    254 			const struct sysent *callp;
    255 			size_t argsize;
    256 			register_t code, error;
    257 			register_t *params, rval[2];
    258 			int n;
    259 			register_t args[10];
    260 
    261 			KERNEL_PROC_LOCK(l);
    262 
    263 			uvmexp.syscalls++;
    264 
    265 			code = frame->fixreg[0];
    266 			callp = p->p_emul->e_sysent;
    267 			params = frame->fixreg + FIRSTARG;
    268 			n = NARGREG;
    269 
    270 			switch (code) {
    271 			case SYS_syscall:
    272 				/*
    273 				 * code is first argument,
    274 				 * followed by actual args.
    275 				 */
    276 				code = *params++;
    277 				n -= 1;
    278 				break;
    279 			case SYS___syscall:
    280 				params++;
    281 				code = *params++;
    282 				n -= 2;
    283 				break;
    284 			default:
    285 				break;
    286 			}
    287 
    288 			code &= (SYS_NSYSENT - 1);
    289 			callp += code;
    290 			argsize = callp->sy_argsize;
    291 
    292 			if (argsize > n * sizeof(register_t)) {
    293 				memcpy(args, params, n * sizeof(register_t));
    294 				error = copyin(MOREARGS(frame->fixreg[1]),
    295 					       args + n,
    296 					       argsize - n * sizeof(register_t));
    297 				if (error)
    298 					goto syscall_bad;
    299 				params = args;
    300 			}
    301 
    302 #ifdef	KTRACE
    303 			if (KTRPOINT(p, KTR_SYSCALL))
    304 				ktrsyscall(p, code, argsize, params);
    305 #endif
    306 #ifdef SYSCALL_DEBUG
    307 			if (trapdebug)
    308 				scdebug_call(p, code, args);
    309 #endif
    310 			rval[0] = 0;
    311 			rval[1] = 0;
    312 
    313 			error = (*callp->sy_call)(l, params, rval);
    314 #ifdef SYSCALL_DEBUG
    315 			if (trapdebug)
    316 				scdebug_ret(p, code, error, rval);
    317 #endif
    318 			switch (error) {
    319 			case 0:
    320 				frame->fixreg[FIRSTARG] = rval[0];
    321 				frame->fixreg[FIRSTARG + 1] = rval[1];
    322 				frame->cr &= ~0x10000000;
    323 				break;
    324 			case ERESTART:
    325 				/*
    326 				 * Set user's pc back to redo the system call.
    327 				 */
    328 				frame->srr0 -= 4;
    329 				break;
    330 			case EJUSTRETURN:
    331 				/* nothing to do */
    332 				break;
    333 			default:
    334 syscall_bad:
    335 				if (p->p_emul->e_errno)
    336 					error = p->p_emul->e_errno[error];
    337 				frame->fixreg[FIRSTARG] = error;
    338 				frame->cr |= 0x10000000;
    339 				break;
    340 			}
    341 
    342 #ifdef	KTRACE
    343 			if (KTRPOINT(p, KTR_SYSRET))
    344 				ktrsysret(p, code, error, rval[0]);
    345 #endif
    346 		}
    347 		KERNEL_PROC_UNLOCK(l);
    348 		break;
    349 
    350 	case EXC_AST|EXC_USER:
    351 		astpending = 0;		/* we are about to do it */
    352 		KERNEL_PROC_LOCK(l);
    353 		uvmexp.softs++;
    354 		if (p->p_flag & P_OWEUPC) {
    355 			p->p_flag &= ~P_OWEUPC;
    356 			ADDUPROF(p);
    357 		}
    358 		/* Check whether we are being preempted. */
    359 		if (want_resched)
    360 			preempt(NULL);
    361 		KERNEL_PROC_UNLOCK(l);
    362 		break;
    363 
    364 
    365 	case EXC_ALI|EXC_USER:
    366 		KERNEL_PROC_LOCK(l);
    367 		if (fix_unaligned(l, frame) != 0)
    368 			trapsignal(l, SIGBUS, EXC_ALI);
    369 		else
    370 			frame->srr0 += 4;
    371 		KERNEL_PROC_UNLOCK(l);
    372 		break;
    373 
    374 	case EXC_PGM|EXC_USER:
    375 		/*
    376 		 * Illegal insn:
    377 		 *
    378 		 * let's try to see if it's FPU and can be emulated.
    379 		 */
    380 		uvmexp.traps ++;
    381 		if (!(l->l_addr->u_pcb.pcb_flags & PCB_FPU)) {
    382 			memset(&l->l_addr->u_pcb.pcb_fpu, 0,
    383 				sizeof l->l_addr->u_pcb.pcb_fpu);
    384 			l->l_addr->u_pcb.pcb_flags |= PCB_FPU;
    385 		}
    386 
    387 		if ((rv = fpu_emulate(frame,
    388 			(struct fpreg *)&l->l_addr->u_pcb.pcb_fpu))) {
    389 			KERNEL_PROC_LOCK(l);
    390 			trapsignal(l, rv, EXC_PGM);
    391 			KERNEL_PROC_UNLOCK(l);
    392 		}
    393 		break;
    394 
    395 	case EXC_MCHK:
    396 		{
    397 			faultbuf *fb;
    398 
    399 			if ((fb = l->l_addr->u_pcb.pcb_onfault) != NULL) {
    400 				frame->pid = KERNEL_PID;
    401 				frame->srr0 = (*fb)[0];
    402 				frame->srr1 |= PSL_IR; /* Re-enable IMMU */
    403 				frame->fixreg[1] = (*fb)[1];
    404 				frame->fixreg[2] = (*fb)[2];
    405 				frame->fixreg[3] = 1; /* Return TRUE */
    406 				frame->cr = (*fb)[3];
    407 				memcpy(&frame->fixreg[13], &(*fb)[4],
    408 				      19 * sizeof(register_t));
    409 				goto done;
    410 			}
    411 		}
    412 		goto brain_damage;
    413 	default:
    414 brain_damage:
    415 		printf("trap type 0x%x at 0x%x\n", type, frame->srr0);
    416 #ifdef DDB
    417 		if (kdb_trap(type, frame))
    418 			goto done;
    419 #endif
    420 #ifdef TRAP_PANICWAIT
    421 		printf("Press a key to panic.\n");
    422 		cngetc();
    423 #endif
    424 		panic("trap");
    425 	}
    426 
    427 	/* Take pending signals. */
    428 	{
    429 		int sig;
    430 
    431 		while ((sig = CURSIG(l)) != 0)
    432 			postsig(sig);
    433 	}
    434 
    435 	/* If our process is on the way out, die. */
    436 	if (p->p_flag & P_WEXIT)
    437 		lwp_exit(l);
    438 
    439 	/* Invoke any pending upcalls */
    440 	if (l->l_flag & L_SA_UPCALL)
    441 		sa_upcall_userret(l);
    442 
    443 	curcpu()->ci_schedstate.spc_curpriority = l->l_priority = l->l_usrpri;
    444   done:
    445 }
    446 
    447 int
    448 ctx_setup(int ctx, int srr1)
    449 {
    450 	volatile struct pmap *pm;
    451 
    452 	/* Update PID if we're returning to user mode. */
    453 	if (srr1 & PSL_PR) {
    454 		pm = curproc->l_proc->p_vmspace->vm_map.pmap;
    455 		if (!pm->pm_ctx) {
    456 			ctx_alloc((struct pmap *)pm);
    457 		}
    458 		ctx = pm->pm_ctx;
    459 		if (srr1 & PSL_SE) {
    460 			int dbreg, mask = 0x48000000;
    461 				/*
    462 				 * Set the Internal Debug and
    463 				 * Instruction Completion bits of
    464 				 * the DBCR0 register.
    465 				 *
    466 				 * XXX this is also used by jtag debuggers...
    467 				 */
    468 			__asm __volatile("mfspr %0,0x3f2;"
    469 				"or %0,%0,%1;"
    470 				"mtspr 0x3f2,%0;" :
    471 				"=&r" (dbreg) : "r" (mask));
    472 		}
    473 	}
    474 	else if (!ctx) {
    475 		ctx = KERNEL_PID;
    476 	}
    477 	return (ctx);
    478 }
    479 
    480 void
    481 child_return(void *arg)
    482 {
    483 	struct lwp *l = arg;
    484 	struct proc *p = l->l_proc;
    485 	struct trapframe *tf = trapframe(l);
    486 
    487 	KERNEL_PROC_UNLOCK(l);
    488 
    489 	tf->fixreg[FIRSTARG] = 0;
    490 	tf->fixreg[FIRSTARG + 1] = 1;
    491 	tf->cr &= ~0x10000000;
    492 	tf->srr1 &= ~(PSL_FP|PSL_VEC);	/* Disable FP & AltiVec, as we can't be them */
    493 #ifdef	KTRACE
    494 	if (KTRPOINT(p, KTR_SYSRET)) {
    495 		KERNEL_PROC_LOCK(l);
    496 		ktrsysret(p, SYS_fork, 0, 0);
    497 		KERNEL_PROC_UNLOCK(l);
    498 	}
    499 #endif
    500 	/* Profiling?							XXX */
    501 	curcpu()->ci_schedstate.spc_curpriority = l->l_priority;
    502 }
    503 
    504 /*
    505  * Used by copyin()/copyout()
    506  */
    507 extern vaddr_t vmaprange __P((struct proc *, vaddr_t, vsize_t, int));
    508 extern void vunmaprange __P((vaddr_t, vsize_t));
    509 static int bigcopyin __P((const void *,	void *,	size_t ));
    510 static int bigcopyout __P((const void *, void *, size_t ));
    511 
    512 int
    513 copyin(const void *udaddr, void *kaddr, size_t len)
    514 {
    515 	struct pmap *pm = curproc->l_proc->p_vmspace->vm_map.pmap;
    516 	int msr, pid, tmp, ctx;
    517 	faultbuf env;
    518 
    519 	/* For bigger buffers use the faster copy */
    520 	if (len > 256) return (bigcopyin(udaddr, kaddr, len));
    521 
    522 	if (setfault(env)) {
    523 		curpcb->pcb_onfault = 0;
    524 		return EFAULT;
    525 	}
    526 
    527 	if (!(ctx = pm->pm_ctx)) {
    528 		/* No context -- assign it one */
    529 		ctx_alloc(pm);
    530 		ctx = pm->pm_ctx;
    531 	}
    532 
    533 	asm volatile("addi %6,%6,1; mtctr %6;"	/* Set up counter */
    534 		"mfmsr %0;"			/* Save MSR */
    535 		"li %1,0x20; "
    536 		"andc %1,%0,%1; mtmsr %1;"	/* Disable IMMU */
    537 		"mfpid %1;"			/* Save old PID */
    538 		"sync; isync;"
    539 
    540 		"1: bdz 2f;"			/* while len */
    541 		"mtpid %3; sync;"		/* Load user ctx */
    542 		"lbz %2,0(%4); addi %4,%4,1;"	/* Load byte */
    543 		"sync; isync;"
    544 		"mtpid %1;sync;"
    545 		"stb %2,0(%5); dcbf 0,%5; addi %5,%5,1;"	/* Store kernel byte */
    546 		"sync; isync;"
    547 		"b 1b;"				/* repeat */
    548 
    549 		"2: mtpid %1; mtmsr %0;"	/* Restore PID and MSR */
    550 		"sync; isync;"
    551 		: "=&r" (msr), "=&r" (pid), "=&r" (tmp)
    552 		: "r" (ctx), "r" (udaddr), "r" (kaddr), "r" (len));
    553 
    554 	curpcb->pcb_onfault = 0;
    555 	return 0;
    556 }
    557 
    558 static int
    559 bigcopyin(const void *udaddr, void *kaddr, size_t len)
    560 {
    561 	const char *up;
    562 	char *kp = kaddr;
    563 	struct lwp *l = curproc;
    564 	struct proc *p;
    565 	int error;
    566 
    567 	if (!l) {
    568 		return EFAULT;
    569 	}
    570 
    571 	p = l->l_proc;
    572 
    573 	/*
    574 	 * Stolen from physio():
    575 	 */
    576 	PHOLD(l);
    577 	error = uvm_vslock(p, (caddr_t)udaddr, len, VM_PROT_READ);
    578 	if (error) {
    579 		PRELE(l);
    580 		return EFAULT;
    581 	}
    582 	up = (char *)vmaprange(p, (vaddr_t)udaddr, len, VM_PROT_READ);
    583 
    584 	memcpy(kp, up, len);
    585 	vunmaprange((vaddr_t)up, len);
    586 	uvm_vsunlock(p, (caddr_t)udaddr, len);
    587 	PRELE(l);
    588 
    589 	return 0;
    590 }
    591 
    592 int
    593 copyout(const void *kaddr, void *udaddr, size_t len)
    594 {
    595 	struct pmap *pm = curproc->l_proc->p_vmspace->vm_map.pmap;
    596 	int msr, pid, tmp, ctx;
    597 	faultbuf env;
    598 
    599 	/* For big copies use more efficient routine */
    600 	if (len > 256) return (bigcopyout(kaddr, udaddr, len));
    601 
    602 	if (setfault(env)) {
    603 		curpcb->pcb_onfault = 0;
    604 		return EFAULT;
    605 	}
    606 
    607 	if (!(ctx = pm->pm_ctx)) {
    608 		/* No context -- assign it one */
    609 		ctx_alloc(pm);
    610 		ctx = pm->pm_ctx;
    611 	}
    612 
    613 	asm volatile("addi %6,%6,1; mtctr %6;"	/* Set up counter */
    614 		"mfmsr %0;"			/* Save MSR */
    615 		"li %1,0x20; "
    616 		"andc %1,%0,%1; mtmsr %1;"	/* Disable IMMU */
    617 		"mfpid %1;"			/* Save old PID */
    618 		"sync; isync;"
    619 
    620 		"1: bdz 2f;"			/* while len */
    621 		"mtpid %1;sync;"
    622 		"lbz %2,0(%5); addi %5,%5,1;"	/* Load kernel byte */
    623 		"sync; isync;"
    624 		"mtpid %3; sync;"		/* Load user ctx */
    625 		"stb %2,0(%4);  dcbf 0,%4; addi %4,%4,1;"	/* Store user byte */
    626 		"sync; isync;"
    627 		"b 1b;"				/* repeat */
    628 
    629 		"2: mtpid %1; mtmsr %0;"	/* Restore PID and MSR */
    630 		"sync; isync;"
    631 		: "=&r" (msr), "=&r" (pid), "=&r" (tmp)
    632 		: "r" (ctx), "r" (udaddr), "r" (kaddr), "r" (len));
    633 
    634 	curpcb->pcb_onfault = 0;
    635 	return 0;
    636 }
    637 
    638 static int
    639 bigcopyout(const void *kaddr, void *udaddr, size_t len)
    640 {
    641 	char *up;
    642 	const char *kp = (char *)kaddr;
    643 	struct lwp *l = curproc;
    644 	struct proc *p;
    645 	int error;
    646 
    647 	if (!l) {
    648 		return EFAULT;
    649 	}
    650 
    651 	p = l->l_proc;
    652 
    653 	/*
    654 	 * Stolen from physio():
    655 	 */
    656 	PHOLD(l);
    657 	error = uvm_vslock(p, udaddr, len, VM_PROT_READ|VM_PROT_WRITE);
    658 	if (error) {
    659 		PRELE(l);
    660 		return EFAULT;
    661 	}
    662 	up = (char *)vmaprange(p, (vaddr_t)udaddr, len,
    663 		VM_PROT_READ|VM_PROT_WRITE);
    664 
    665 	memcpy(up, kp, len);
    666 	vunmaprange((vaddr_t)up, len);
    667 	uvm_vsunlock(p, udaddr, len);
    668 	PRELE(l);
    669 
    670 	return 0;
    671 }
    672 
    673 /*
    674  * kcopy(const void *src, void *dst, size_t len);
    675  *
    676  * Copy len bytes from src to dst, aborting if we encounter a fatal
    677  * page fault.
    678  *
    679  * kcopy() _must_ save and restore the old fault handler since it is
    680  * called by uiomove(), which may be in the path of servicing a non-fatal
    681  * page fault.
    682  */
    683 int
    684 kcopy(const void *src, void *dst, size_t len)
    685 {
    686 	faultbuf env, *oldfault;
    687 
    688 	oldfault = curpcb->pcb_onfault;
    689 	if (setfault(env)) {
    690 		curpcb->pcb_onfault = oldfault;
    691 		return EFAULT;
    692 	}
    693 
    694 	memcpy(dst, src, len);
    695 
    696 	curpcb->pcb_onfault = oldfault;
    697 	return 0;
    698 }
    699 
    700 int
    701 badaddr(void *addr, size_t size)
    702 {
    703 
    704 	return badaddr_read(addr, size, NULL);
    705 }
    706 
    707 int
    708 badaddr_read(void *addr, size_t size, int *rptr)
    709 {
    710 	faultbuf env;
    711 	int x;
    712 
    713 	/* Get rid of any stale machine checks that have been waiting.  */
    714 	__asm __volatile ("sync; isync");
    715 
    716 	if (setfault(env)) {
    717 		curpcb->pcb_onfault = 0;
    718 		__asm __volatile ("sync");
    719 		return 1;
    720 	}
    721 
    722 	__asm __volatile ("sync");
    723 
    724 	switch (size) {
    725 	case 1:
    726 		x = *(volatile int8_t *)addr;
    727 		break;
    728 	case 2:
    729 		x = *(volatile int16_t *)addr;
    730 		break;
    731 	case 4:
    732 		x = *(volatile int32_t *)addr;
    733 		break;
    734 	default:
    735 		panic("badaddr: invalid size (%d)", size);
    736 	}
    737 
    738 	/* Make sure we took the machine check, if we caused one. */
    739 	__asm __volatile ("sync; isync");
    740 
    741 	curpcb->pcb_onfault = 0;
    742 	__asm __volatile ("sync");	/* To be sure. */
    743 
    744 	/* Use the value to avoid reorder. */
    745 	if (rptr)
    746 		*rptr = x;
    747 
    748 	return 0;
    749 }
    750 
    751 /*
    752  * For now, this only deals with the particular unaligned access case
    753  * that gcc tends to generate.  Eventually it should handle all of the
    754  * possibilities that can happen on a 32-bit PowerPC in big-endian mode.
    755  */
    756 
    757 static int
    758 fix_unaligned(struct lwp *l, struct trapframe *frame)
    759 {
    760 
    761 	return -1;
    762 }
    763 
    764 /*
    765  * Start a new LWP
    766  */
    767 void
    768 startlwp(arg)
    769 	void *arg;
    770 {
    771 	int err;
    772 	ucontext_t *uc = arg;
    773 	struct lwp *l = curproc;
    774 
    775 	err = cpu_setmcontext(l, &uc->uc_mcontext, uc->uc_flags);
    776 #if DIAGNOSTIC
    777 	if (err) {
    778 		printf("Error %d from cpu_setmcontext.", err);
    779 	}
    780 #endif
    781 	pool_put(&lwp_uc_pool, uc);
    782 
    783 	upcallret(l);
    784 }
    785 
    786 /*
    787  * XXX This is a terrible name.
    788  */
    789 void
    790 upcallret(arg)
    791 	void *arg;
    792 {
    793 	struct lwp *l = curproc;
    794 	int sig;
    795 
    796 	/* Take pending signals. */
    797 	while ((sig = CURSIG(l)) != 0)
    798 		postsig(sig);
    799 
    800 	/* If our process is on the way out, die. */
    801 	if (l->l_proc->p_flag & P_WEXIT)
    802 		lwp_exit(l);
    803 
    804 	/* Invoke any pending upcalls */
    805 	if (l->l_flag & L_SA_UPCALL)
    806 		sa_upcall_userret(l);
    807 
    808 	curcpu()->ci_schedstate.spc_curpriority = l->l_priority = l->l_usrpri;
    809 }
    810