trap.c revision 1.35 1 /* $NetBSD: trap.c,v 1.35 2006/07/19 21:11:45 ad 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 1.35 2006/07/19 21:11:45 ad 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 LWP_CACHE_CREDS(l, p);
138 type |= EXC_USER;
139 }
140
141 ftype = VM_PROT_READ;
142
143 DBPRINTF(TDB_ALL, ("trap(%x) at %lx from frame %p &frame %p\n",
144 type, frame->srr0, frame, &frame));
145
146 switch (type) {
147 case EXC_DEBUG|EXC_USER:
148 {
149 int srr2, srr3;
150
151 __asm volatile("mfspr %0,0x3f0" :
152 "=r" (rv), "=r" (srr2), "=r" (srr3) :);
153 printf("debug reg is %x srr2 %x srr3 %x\n", rv, srr2,
154 srr3);
155 /* XXX fall through or break here?! */
156 }
157 /*
158 * DEBUG intr -- probably single-step.
159 */
160 case EXC_TRC|EXC_USER:
161 frame->srr1 &= ~PSL_SE;
162 KSI_INIT_TRAP(&ksi);
163 ksi.ksi_signo = SIGTRAP;
164 ksi.ksi_trap = EXC_TRC;
165 ksi.ksi_addr = (void *)frame->srr0;
166 KERNEL_PROC_LOCK(l);
167 trapsignal(l, &ksi);
168 KERNEL_PROC_UNLOCK(l);
169 break;
170
171 /*
172 * If we could not find and install appropriate TLB entry, fall through.
173 */
174
175 case EXC_DSI:
176 /* FALLTHROUGH */
177 case EXC_DTMISS:
178 {
179 struct vm_map *map;
180 vaddr_t va;
181 struct faultbuf *fb = NULL;
182
183 KERNEL_LOCK(LK_CANRECURSE|LK_EXCLUSIVE);
184 va = frame->dar;
185 if (frame->tf_xtra[TF_PID] == KERNEL_PID) {
186 map = kernel_map;
187 } else {
188 map = &p->p_vmspace->vm_map;
189 if (l->l_flag & L_SA) {
190 l->l_savp->savp_faultaddr = va;
191 l->l_flag |= L_SA_PAGEFAULT;
192 }
193 }
194
195 if (frame->tf_xtra[TF_ESR] & (ESR_DST|ESR_DIZ))
196 ftype = VM_PROT_WRITE;
197
198 DBPRINTF(TDB_ALL,
199 ("trap(EXC_DSI) at %lx %s fault on %p esr %x\n",
200 frame->srr0,
201 (ftype & VM_PROT_WRITE) ? "write" : "read",
202 (void *)va, frame->tf_xtra[TF_ESR]));
203 rv = uvm_fault(map, trunc_page(va), ftype);
204 KERNEL_UNLOCK();
205 if (map != kernel_map)
206 l->l_flag &= ~L_SA_PAGEFAULT;
207 if (rv == 0)
208 goto done;
209 if ((fb = l->l_addr->u_pcb.pcb_onfault) != NULL) {
210 frame->tf_xtra[TF_PID] = KERNEL_PID;
211 frame->srr0 = fb->fb_pc;
212 frame->srr1 |= PSL_IR; /* Re-enable IMMU */
213 frame->fixreg[1] = fb->fb_sp;
214 frame->fixreg[2] = fb->fb_r2;
215 frame->fixreg[3] = 1; /* Return TRUE */
216 frame->cr = fb->fb_cr;
217 memcpy(&frame->fixreg[13], fb->fb_fixreg,
218 sizeof(fb->fb_fixreg));
219 goto done;
220 }
221 }
222 goto brain_damage;
223
224 case EXC_DSI|EXC_USER:
225 /* FALLTHROUGH */
226 case EXC_DTMISS|EXC_USER:
227 KERNEL_PROC_LOCK(l);
228
229 if (frame->tf_xtra[TF_ESR] & (ESR_DST|ESR_DIZ))
230 ftype = VM_PROT_WRITE;
231
232 DBPRINTF(TDB_ALL,
233 ("trap(EXC_DSI|EXC_USER) at %lx %s fault on %lx %x\n",
234 frame->srr0, (ftype & VM_PROT_WRITE) ? "write" : "read",
235 frame->dar, frame->tf_xtra[TF_ESR]));
236 KASSERT(l == curlwp && (l->l_stat == LSONPROC));
237 if (l->l_flag & L_SA) {
238 l->l_savp->savp_faultaddr = (vaddr_t)frame->dar;
239 l->l_flag |= L_SA_PAGEFAULT;
240 }
241 rv = uvm_fault(&p->p_vmspace->vm_map, trunc_page(frame->dar),
242 ftype);
243 if (rv == 0) {
244 l->l_flag &= ~L_SA_PAGEFAULT;
245 KERNEL_PROC_UNLOCK(l);
246 break;
247 }
248 KSI_INIT_TRAP(&ksi);
249 ksi.ksi_signo = SIGSEGV;
250 ksi.ksi_trap = EXC_DSI;
251 ksi.ksi_addr = (void *)frame->dar;
252 if (rv == ENOMEM) {
253 printf("UVM: pid %d (%s) lid %d, uid %d killed: "
254 "out of swap\n",
255 p->p_pid, p->p_comm, l->l_lid,
256 p->p_cred ?
257 kauth_cred_geteuid(p->p_cred) : -1);
258 ksi.ksi_signo = SIGKILL;
259 }
260 trapsignal(l, &ksi);
261 l->l_flag &= ~L_SA_PAGEFAULT;
262 KERNEL_PROC_UNLOCK(l);
263 break;
264
265 case EXC_ITMISS|EXC_USER:
266 case EXC_ISI|EXC_USER:
267 KERNEL_PROC_LOCK(l);
268 if (l->l_flag & L_SA) {
269 l->l_savp->savp_faultaddr = (vaddr_t)frame->srr0;
270 l->l_flag |= L_SA_PAGEFAULT;
271 }
272 ftype = VM_PROT_EXECUTE;
273 DBPRINTF(TDB_ALL,
274 ("trap(EXC_ISI|EXC_USER) at %lx execute fault tf %p\n",
275 frame->srr0, frame));
276 rv = uvm_fault(&p->p_vmspace->vm_map, trunc_page(frame->srr0),
277 ftype);
278 if (rv == 0) {
279 l->l_flag &= ~L_SA_PAGEFAULT;
280 KERNEL_PROC_UNLOCK(l);
281 break;
282 }
283 KSI_INIT_TRAP(&ksi);
284 ksi.ksi_signo = SIGSEGV;
285 ksi.ksi_trap = EXC_ISI;
286 ksi.ksi_addr = (void *)frame->srr0;
287 ksi.ksi_code = (rv == EACCES ? SEGV_ACCERR : SEGV_MAPERR);
288 trapsignal(l, &ksi);
289 l->l_flag &= ~L_SA_PAGEFAULT;
290 KERNEL_PROC_UNLOCK(l);
291 break;
292
293 case EXC_AST|EXC_USER:
294 curcpu()->ci_astpending = 0; /* we are about to do it */
295 KERNEL_PROC_LOCK(l);
296 uvmexp.softs++;
297 if (p->p_flag & P_OWEUPC) {
298 p->p_flag &= ~P_OWEUPC;
299 ADDUPROF(p);
300 }
301 /* Check whether we are being preempted. */
302 if (curcpu()->ci_want_resched)
303 preempt(0);
304 KERNEL_PROC_UNLOCK(l);
305 break;
306
307
308 case EXC_ALI|EXC_USER:
309 KERNEL_PROC_LOCK(l);
310 if (fix_unaligned(l, frame) != 0) {
311 KSI_INIT_TRAP(&ksi);
312 ksi.ksi_signo = SIGBUS;
313 ksi.ksi_trap = EXC_ALI;
314 ksi.ksi_addr = (void *)frame->dar;
315 trapsignal(l, &ksi);
316 } else
317 frame->srr0 += 4;
318 KERNEL_PROC_UNLOCK(l);
319 break;
320
321 case EXC_PGM|EXC_USER:
322 /*
323 * Illegal insn:
324 *
325 * let's try to see if it's FPU and can be emulated.
326 */
327 uvmexp.traps++;
328 if (!(l->l_addr->u_pcb.pcb_flags & PCB_FPU)) {
329 memset(&l->l_addr->u_pcb.pcb_fpu, 0,
330 sizeof l->l_addr->u_pcb.pcb_fpu);
331 l->l_addr->u_pcb.pcb_flags |= PCB_FPU;
332 }
333
334 if ((rv = fpu_emulate(frame,
335 (struct fpreg *)&l->l_addr->u_pcb.pcb_fpu))) {
336 KSI_INIT_TRAP(&ksi);
337 ksi.ksi_signo = rv;
338 ksi.ksi_trap = EXC_PGM;
339 ksi.ksi_addr = (void *)frame->srr0;
340 KERNEL_PROC_LOCK(l);
341 trapsignal(l, &ksi);
342 KERNEL_PROC_UNLOCK(l);
343 }
344 break;
345
346 case EXC_MCHK:
347 {
348 struct faultbuf *fb;
349
350 if ((fb = l->l_addr->u_pcb.pcb_onfault) != NULL) {
351 frame->tf_xtra[TF_PID] = KERNEL_PID;
352 frame->srr0 = fb->fb_pc;
353 frame->srr1 |= PSL_IR; /* Re-enable IMMU */
354 frame->fixreg[1] = fb->fb_sp;
355 frame->fixreg[2] = fb->fb_r2;
356 frame->fixreg[3] = 1; /* Return TRUE */
357 frame->cr = fb->fb_cr;
358 memcpy(&frame->fixreg[13], fb->fb_fixreg,
359 sizeof(fb->fb_fixreg));
360 goto done;
361 }
362 }
363 goto brain_damage;
364 default:
365 brain_damage:
366 printf("trap type 0x%x at 0x%lx\n", type, frame->srr0);
367 #ifdef DDB
368 if (kdb_trap(type, frame))
369 goto done;
370 #endif
371 #ifdef TRAP_PANICWAIT
372 printf("Press a key to panic.\n");
373 cngetc();
374 #endif
375 panic("trap");
376 }
377
378 /* Invoke MI userret code */
379 mi_userret(l);
380
381 curcpu()->ci_schedstate.spc_curpriority = l->l_priority = l->l_usrpri;
382 done:
383 return;
384 }
385
386 int
387 ctx_setup(int ctx, int srr1)
388 {
389 volatile struct pmap *pm;
390
391 /* Update PID if we're returning to user mode. */
392 if (srr1 & PSL_PR) {
393 pm = curproc->p_vmspace->vm_map.pmap;
394 if (!pm->pm_ctx) {
395 ctx_alloc(__UNVOLATILE(pm));
396 }
397 ctx = pm->pm_ctx;
398 if (srr1 & PSL_SE) {
399 int dbreg, mask = 0x48000000;
400 /*
401 * Set the Internal Debug and
402 * Instruction Completion bits of
403 * the DBCR0 register.
404 *
405 * XXX this is also used by jtag debuggers...
406 */
407 __asm volatile("mfspr %0,0x3f2;"
408 "or %0,%0,%1;"
409 "mtspr 0x3f2,%0;" :
410 "=&r" (dbreg) : "r" (mask));
411 }
412 }
413 else if (!ctx) {
414 ctx = KERNEL_PID;
415 }
416 return (ctx);
417 }
418
419 /*
420 * Used by copyin()/copyout()
421 */
422 extern vaddr_t vmaprange __P((struct proc *, vaddr_t, vsize_t, int));
423 extern void vunmaprange __P((vaddr_t, vsize_t));
424 static int bigcopyin __P((const void *, void *, size_t ));
425 static int bigcopyout __P((const void *, void *, size_t ));
426
427 int
428 copyin(const void *udaddr, void *kaddr, size_t len)
429 {
430 struct pmap *pm = curproc->p_vmspace->vm_map.pmap;
431 int msr, pid, tmp, ctx;
432 struct faultbuf env;
433
434 /* For bigger buffers use the faster copy */
435 if (len > 256)
436 return (bigcopyin(udaddr, kaddr, len));
437
438 if (setfault(&env)) {
439 curpcb->pcb_onfault = 0;
440 return EFAULT;
441 }
442
443 if (!(ctx = pm->pm_ctx)) {
444 /* No context -- assign it one */
445 ctx_alloc(pm);
446 ctx = pm->pm_ctx;
447 }
448
449 __asm volatile("addi %6,%6,1; mtctr %6;" /* Set up counter */
450 "mfmsr %0;" /* Save MSR */
451 "li %1,0x20; "
452 "andc %1,%0,%1; mtmsr %1;" /* Disable IMMU */
453 "mfpid %1;" /* Save old PID */
454 "sync; isync;"
455
456 "1: bdz 2f;" /* while len */
457 "mtpid %3; sync;" /* Load user ctx */
458 "lbz %2,0(%4); addi %4,%4,1;" /* Load byte */
459 "sync; isync;"
460 "mtpid %1;sync;"
461 "stb %2,0(%5); dcbf 0,%5; addi %5,%5,1;" /* Store kernel byte */
462 "sync; isync;"
463 "b 1b;" /* repeat */
464
465 "2: mtpid %1; mtmsr %0;" /* Restore PID and MSR */
466 "sync; isync;"
467 : "=&r" (msr), "=&r" (pid), "=&r" (tmp)
468 : "r" (ctx), "b" (udaddr), "b" (kaddr), "b" (len));
469
470 curpcb->pcb_onfault = 0;
471 return 0;
472 }
473
474 static int
475 bigcopyin(const void *udaddr, void *kaddr, size_t len)
476 {
477 const char *up;
478 char *kp = kaddr;
479 struct lwp *l = curlwp;
480 struct proc *p;
481 int error;
482
483 if (!l) {
484 return EFAULT;
485 }
486
487 p = l->l_proc;
488
489 /*
490 * Stolen from physio():
491 */
492 PHOLD(l);
493 error = uvm_vslock(p, __UNCONST(udaddr), len, VM_PROT_READ);
494 if (error) {
495 PRELE(l);
496 return EFAULT;
497 }
498 up = (char *)vmaprange(p, (vaddr_t)udaddr, len, VM_PROT_READ);
499
500 memcpy(kp, up, len);
501 vunmaprange((vaddr_t)up, len);
502 uvm_vsunlock(p, __UNCONST(udaddr), len);
503 PRELE(l);
504
505 return 0;
506 }
507
508 int
509 copyout(const void *kaddr, void *udaddr, size_t len)
510 {
511 struct pmap *pm = curproc->p_vmspace->vm_map.pmap;
512 int msr, pid, tmp, ctx;
513 struct faultbuf env;
514
515 /* For big copies use more efficient routine */
516 if (len > 256)
517 return (bigcopyout(kaddr, udaddr, len));
518
519 if (setfault(&env)) {
520 curpcb->pcb_onfault = 0;
521 return EFAULT;
522 }
523
524 if (!(ctx = pm->pm_ctx)) {
525 /* No context -- assign it one */
526 ctx_alloc(pm);
527 ctx = pm->pm_ctx;
528 }
529
530 __asm volatile("addi %6,%6,1; mtctr %6;" /* Set up counter */
531 "mfmsr %0;" /* Save MSR */
532 "li %1,0x20; "
533 "andc %1,%0,%1; mtmsr %1;" /* Disable IMMU */
534 "mfpid %1;" /* Save old PID */
535 "sync; isync;"
536
537 "1: bdz 2f;" /* while len */
538 "mtpid %1;sync;"
539 "lbz %2,0(%5); addi %5,%5,1;" /* Load kernel byte */
540 "sync; isync;"
541 "mtpid %3; sync;" /* Load user ctx */
542 "stb %2,0(%4); dcbf 0,%4; addi %4,%4,1;" /* Store user byte */
543 "sync; isync;"
544 "b 1b;" /* repeat */
545
546 "2: mtpid %1; mtmsr %0;" /* Restore PID and MSR */
547 "sync; isync;"
548 : "=&r" (msr), "=&r" (pid), "=&r" (tmp)
549 : "r" (ctx), "b" (udaddr), "b" (kaddr), "b" (len));
550
551 curpcb->pcb_onfault = 0;
552 return 0;
553 }
554
555 static int
556 bigcopyout(const void *kaddr, void *udaddr, size_t len)
557 {
558 char *up;
559 const char *kp = (const char *)kaddr;
560 struct lwp *l = curlwp;
561 struct proc *p;
562 int error;
563
564 if (!l) {
565 return EFAULT;
566 }
567
568 p = l->l_proc;
569
570 /*
571 * Stolen from physio():
572 */
573 PHOLD(l);
574 error = uvm_vslock(p, udaddr, len, VM_PROT_WRITE);
575 if (error) {
576 PRELE(l);
577 return EFAULT;
578 }
579 up = (char *)vmaprange(p, (vaddr_t)udaddr, len,
580 VM_PROT_READ | VM_PROT_WRITE);
581
582 memcpy(up, kp, len);
583 vunmaprange((vaddr_t)up, len);
584 uvm_vsunlock(p, udaddr, len);
585 PRELE(l);
586
587 return 0;
588 }
589
590 /*
591 * kcopy(const void *src, void *dst, size_t len);
592 *
593 * Copy len bytes from src to dst, aborting if we encounter a fatal
594 * page fault.
595 *
596 * kcopy() _must_ save and restore the old fault handler since it is
597 * called by uiomove(), which may be in the path of servicing a non-fatal
598 * page fault.
599 */
600 int
601 kcopy(const void *src, void *dst, size_t len)
602 {
603 struct faultbuf env, *oldfault;
604
605 oldfault = curpcb->pcb_onfault;
606 if (setfault(&env)) {
607 curpcb->pcb_onfault = oldfault;
608 return EFAULT;
609 }
610
611 memcpy(dst, src, len);
612
613 curpcb->pcb_onfault = oldfault;
614 return 0;
615 }
616
617 int
618 badaddr(void *addr, size_t size)
619 {
620
621 return badaddr_read(addr, size, NULL);
622 }
623
624 int
625 badaddr_read(void *addr, size_t size, int *rptr)
626 {
627 struct faultbuf env;
628 int x;
629
630 /* Get rid of any stale machine checks that have been waiting. */
631 __asm volatile ("sync; isync");
632
633 if (setfault(&env)) {
634 curpcb->pcb_onfault = 0;
635 __asm volatile ("sync");
636 return 1;
637 }
638
639 __asm volatile ("sync");
640
641 switch (size) {
642 case 1:
643 x = *(volatile int8_t *)addr;
644 break;
645 case 2:
646 x = *(volatile int16_t *)addr;
647 break;
648 case 4:
649 x = *(volatile int32_t *)addr;
650 break;
651 default:
652 panic("badaddr: invalid size (%d)", size);
653 }
654
655 /* Make sure we took the machine check, if we caused one. */
656 __asm volatile ("sync; isync");
657
658 curpcb->pcb_onfault = 0;
659 __asm volatile ("sync"); /* To be sure. */
660
661 /* Use the value to avoid reorder. */
662 if (rptr)
663 *rptr = x;
664
665 return 0;
666 }
667
668 /*
669 * For now, this only deals with the particular unaligned access case
670 * that gcc tends to generate. Eventually it should handle all of the
671 * possibilities that can happen on a 32-bit PowerPC in big-endian mode.
672 */
673
674 static int
675 fix_unaligned(struct lwp *l, struct trapframe *frame)
676 {
677
678 return -1;
679 }
680
681 /*
682 * Start a new LWP
683 */
684 void
685 startlwp(arg)
686 void *arg;
687 {
688 int err;
689 ucontext_t *uc = arg;
690 struct lwp *l = curlwp;
691
692 err = cpu_setmcontext(l, &uc->uc_mcontext, uc->uc_flags);
693 #if DIAGNOSTIC
694 if (err) {
695 printf("Error %d from cpu_setmcontext.", err);
696 }
697 #endif
698 pool_put(&lwp_uc_pool, uc);
699
700 upcallret(l);
701 }
702
703 /*
704 * XXX This is a terrible name.
705 */
706 void
707 upcallret(l)
708 struct lwp *l;
709 {
710
711 /* Invoke MI userret code */
712 mi_userret(l);
713
714 curcpu()->ci_schedstate.spc_curpriority = l->l_priority = l->l_usrpri;
715 }
716