trap.c revision 1.34 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