1 /*-
2 * Copyright (C) 1995, 1996 Wolfgang Solfrank.
3 * Copyright (C) 1995, 1996 TooLs GmbH.
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * 3. All advertising materials mentioning features or use of this software
15 * must display the following acknowledgement:
16 * This product includes software developed by TooLs GmbH.
17 * 4. The name of TooLs GmbH may not be used to endorse or promote products
18 * derived from this software without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
21 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
22 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
23 * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
24 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
25 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
26 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
27 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
28 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
29 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 *
31 * $NetBSD: trap.c,v 1.58 2002/03/04 04:07:35 dbj Exp $
32 */
33
34 #include <sys/cdefs.h>
35 __FBSDID("$FreeBSD: stable/10/sys/powerpc/aim/trap.c 333205 2018-05-03 07:57:08Z avg $");
36
37 #include "opt_kdtrace.h"
38
39 #include <sys/param.h>
40 #include <sys/kdb.h>
41 #include <sys/proc.h>
42 #include <sys/ktr.h>
43 #include <sys/lock.h>
44 #include <sys/mutex.h>
45 #include <sys/pioctl.h>
46 #include <sys/ptrace.h>
47 #include <sys/reboot.h>
48 #include <sys/syscall.h>
49 #include <sys/sysent.h>
50 #include <sys/systm.h>
51 #include <sys/kernel.h>
52 #include <sys/uio.h>
53 #include <sys/signalvar.h>
54 #include <sys/vmmeter.h>
55
56 #include <security/audit/audit.h>
57
58 #include <vm/vm.h>
59 #include <vm/pmap.h>
60 #include <vm/vm_extern.h>
61 #include <vm/vm_param.h>
62 #include <vm/vm_kern.h>
63 #include <vm/vm_map.h>
64 #include <vm/vm_page.h>
65
66 #include <machine/_inttypes.h>
67 #include <machine/altivec.h>
68 #include <machine/cpu.h>
69 #include <machine/db_machdep.h>
70 #include <machine/fpu.h>
71 #include <machine/frame.h>
72 #include <machine/pcb.h>
73 #include <machine/pmap.h>
74 #include <machine/psl.h>
75 #include <machine/trap.h>
76 #include <machine/spr.h>
77 #include <machine/sr.h>
78
79 static void trap_fatal(struct trapframe *frame);
80 static void printtrap(u_int vector, struct trapframe *frame, int isfatal,
81 int user);
82 static int trap_pfault(struct trapframe *frame, int user);
83 static int fix_unaligned(struct thread *td, struct trapframe *frame);
84 static int handle_onfault(struct trapframe *frame);
85 static void syscall(struct trapframe *frame);
86
87 #ifdef __powerpc64__
88 void handle_kernel_slb_spill(int, register_t, register_t);
89 static int handle_user_slb_spill(pmap_t pm, vm_offset_t addr);
90 extern int n_slbs;
91 #endif
92
93 struct powerpc_exception {
94 u_int vector;
95 char *name;
96 };
97
98 #ifdef KDTRACE_HOOKS
99 #include <sys/dtrace_bsd.h>
100
101 int (*dtrace_invop_jump_addr)(struct trapframe *);
102 #endif
103
104 static struct powerpc_exception powerpc_exceptions[] = {
105 { 0x0100, "system reset" },
106 { 0x0200, "machine check" },
107 { 0x0300, "data storage interrupt" },
108 { 0x0380, "data segment exception" },
109 { 0x0400, "instruction storage interrupt" },
110 { 0x0480, "instruction segment exception" },
111 { 0x0500, "external interrupt" },
112 { 0x0600, "alignment" },
113 { 0x0700, "program" },
114 { 0x0800, "floating-point unavailable" },
115 { 0x0900, "decrementer" },
116 { 0x0c00, "system call" },
117 { 0x0d00, "trace" },
118 { 0x0e00, "floating-point assist" },
119 { 0x0f00, "performance monitoring" },
120 { 0x0f20, "altivec unavailable" },
121 { 0x1000, "instruction tlb miss" },
122 { 0x1100, "data load tlb miss" },
123 { 0x1200, "data store tlb miss" },
124 { 0x1300, "instruction breakpoint" },
125 { 0x1400, "system management" },
126 { 0x1600, "altivec assist" },
127 { 0x1700, "thermal management" },
128 { 0x2000, "run mode/trace" },
129 { 0x3000, NULL }
130 };
131
132 static const char *
trapname(u_int vector)133 trapname(u_int vector)
134 {
135 struct powerpc_exception *pe;
136
137 for (pe = powerpc_exceptions; pe->vector != 0x3000; pe++) {
138 if (pe->vector == vector)
139 return (pe->name);
140 }
141
142 return ("unknown");
143 }
144
145 void
trap(struct trapframe * frame)146 trap(struct trapframe *frame)
147 {
148 struct thread *td;
149 struct proc *p;
150 #ifdef KDTRACE_HOOKS
151 uint32_t inst;
152 #endif
153 int sig, type, user;
154 u_int ucode;
155 ksiginfo_t ksi;
156
157 PCPU_INC(cnt.v_trap);
158
159 td = curthread;
160 p = td->td_proc;
161
162 type = ucode = frame->exc;
163 sig = 0;
164 user = frame->srr1 & PSL_PR;
165
166 CTR3(KTR_TRAP, "trap: %s type=%s (%s)", td->td_name,
167 trapname(type), user ? "user" : "kernel");
168
169 #ifdef KDTRACE_HOOKS
170 /*
171 * A trap can occur while DTrace executes a probe. Before
172 * executing the probe, DTrace blocks re-scheduling and sets
173 * a flag in it's per-cpu flags to indicate that it doesn't
174 * want to fault. On returning from the probe, the no-fault
175 * flag is cleared and finally re-scheduling is enabled.
176 *
177 * If the DTrace kernel module has registered a trap handler,
178 * call it and if it returns non-zero, assume that it has
179 * handled the trap and modified the trap frame so that this
180 * function can return normally.
181 */
182 /*
183 * XXXDTRACE: add pid probe handler here (if ever)
184 */
185 if (dtrace_trap_func != NULL && (*dtrace_trap_func)(frame, type))
186 return;
187 #endif
188
189 if (user) {
190 td->td_pticks = 0;
191 td->td_frame = frame;
192 if (td->td_ucred != p->p_ucred)
193 cred_update_thread(td);
194
195 /* User Mode Traps */
196 switch (type) {
197 case EXC_RUNMODETRC:
198 case EXC_TRC:
199 frame->srr1 &= ~PSL_SE;
200 sig = SIGTRAP;
201 ucode = TRAP_TRACE;
202 break;
203
204 #ifdef __powerpc64__
205 case EXC_ISE:
206 case EXC_DSE:
207 if (handle_user_slb_spill(&p->p_vmspace->vm_pmap,
208 (type == EXC_ISE) ? frame->srr0 :
209 frame->cpu.aim.dar) != 0) {
210 sig = SIGSEGV;
211 ucode = SEGV_MAPERR;
212 }
213 break;
214 #endif
215 case EXC_DSI:
216 case EXC_ISI:
217 sig = trap_pfault(frame, 1);
218 if (sig == SIGSEGV)
219 ucode = SEGV_MAPERR;
220 break;
221
222 case EXC_SC:
223 syscall(frame);
224 break;
225
226 case EXC_FPU:
227 KASSERT((td->td_pcb->pcb_flags & PCB_FPU) != PCB_FPU,
228 ("FPU already enabled for thread"));
229 enable_fpu(td);
230 break;
231
232 case EXC_VEC:
233 KASSERT((td->td_pcb->pcb_flags & PCB_VEC) != PCB_VEC,
234 ("Altivec already enabled for thread"));
235 enable_vec(td);
236 break;
237
238 case EXC_VECAST_G4:
239 case EXC_VECAST_G5:
240 /*
241 * We get a VPU assist exception for IEEE mode
242 * vector operations on denormalized floats.
243 * Emulating this is a giant pain, so for now,
244 * just switch off IEEE mode and treat them as
245 * zero.
246 */
247
248 save_vec(td);
249 td->td_pcb->pcb_vec.vscr |= ALTIVEC_VSCR_NJ;
250 enable_vec(td);
251 break;
252
253 case EXC_ALI:
254 if (fix_unaligned(td, frame) != 0) {
255 sig = SIGBUS;
256 ucode = BUS_ADRALN;
257 }
258 else
259 frame->srr0 += 4;
260 break;
261
262 case EXC_PGM:
263 /* Identify the trap reason */
264 if (frame->srr1 & EXC_PGM_TRAP) {
265 #ifdef KDTRACE_HOOKS
266 inst = fuword32((const void *)frame->srr0);
267 if (inst == 0x0FFFDDDD && dtrace_pid_probe_ptr != NULL) {
268 struct reg regs;
269 fill_regs(td, ®s);
270 (*dtrace_pid_probe_ptr)(®s);
271 break;
272 }
273 #endif
274 sig = SIGTRAP;
275 ucode = TRAP_BRKPT;
276 } else {
277 sig = ppc_instr_emulate(frame, td->td_pcb);
278 if (sig == SIGILL) {
279 if (frame->srr1 & EXC_PGM_PRIV)
280 ucode = ILL_PRVOPC;
281 else if (frame->srr1 & EXC_PGM_ILLEGAL)
282 ucode = ILL_ILLOPC;
283 } else if (sig == SIGFPE)
284 ucode = FPE_FLTINV; /* Punt for now, invalid operation. */
285 }
286 break;
287
288 case EXC_MCHK:
289 /*
290 * Note that this may not be recoverable for the user
291 * process, depending on the type of machine check,
292 * but it at least prevents the kernel from dying.
293 */
294 sig = SIGBUS;
295 ucode = BUS_OBJERR;
296 break;
297
298 default:
299 trap_fatal(frame);
300 }
301 } else {
302 /* Kernel Mode Traps */
303
304 KASSERT(cold || td->td_ucred != NULL,
305 ("kernel trap doesn't have ucred"));
306 switch (type) {
307 #ifdef KDTRACE_HOOKS
308 case EXC_PGM:
309 if (frame->srr1 & EXC_PGM_TRAP) {
310 if (*(uint32_t *)frame->srr0 == 0x7c810808) {
311 if (dtrace_invop_jump_addr != NULL) {
312 dtrace_invop_jump_addr(frame);
313 return;
314 }
315 }
316 }
317 break;
318 #endif
319 #ifdef __powerpc64__
320 case EXC_DSE:
321 if ((frame->cpu.aim.dar & SEGMENT_MASK) == USER_ADDR) {
322 __asm __volatile ("slbmte %0, %1" ::
323 "r"(td->td_pcb->pcb_cpu.aim.usr_vsid),
324 "r"(USER_SLB_SLBE));
325 return;
326 }
327 break;
328 #endif
329 case EXC_DSI:
330 if (trap_pfault(frame, 0) == 0)
331 return;
332 break;
333 case EXC_MCHK:
334 if (handle_onfault(frame))
335 return;
336 break;
337 default:
338 break;
339 }
340 trap_fatal(frame);
341 }
342
343 if (sig != 0) {
344 if (p->p_sysent->sv_transtrap != NULL)
345 sig = (p->p_sysent->sv_transtrap)(sig, type);
346 ksiginfo_init_trap(&ksi);
347 ksi.ksi_signo = sig;
348 ksi.ksi_code = (int) ucode; /* XXX, not POSIX */
349 /* ksi.ksi_addr = ? */
350 ksi.ksi_trapno = type;
351 trapsignal(td, &ksi);
352 }
353
354 userret(td, frame);
355 }
356
357 static void
trap_fatal(struct trapframe * frame)358 trap_fatal(struct trapframe *frame)
359 {
360 #ifdef KDB
361 bool handled;
362 #endif
363
364 printtrap(frame->exc, frame, 1, (frame->srr1 & PSL_PR));
365 #ifdef KDB
366 if (debugger_on_panic) {
367 kdb_why = KDB_WHY_TRAP;
368 handled = kdb_trap(frame->exc, 0, frame);
369 kdb_why = KDB_WHY_UNSET;
370 if (handled)
371 return;
372 }
373 #endif
374 panic("%s trap", trapname(frame->exc));
375 }
376
377 static void
printtrap(u_int vector,struct trapframe * frame,int isfatal,int user)378 printtrap(u_int vector, struct trapframe *frame, int isfatal, int user)
379 {
380
381 printf("\n");
382 printf("%s %s trap:\n", isfatal ? "fatal" : "handled",
383 user ? "user" : "kernel");
384 printf("\n");
385 printf(" exception = 0x%x (%s)\n", vector, trapname(vector));
386 switch (vector) {
387 case EXC_DSE:
388 case EXC_DSI:
389 printf(" virtual address = 0x%" PRIxPTR "\n",
390 frame->cpu.aim.dar);
391 printf(" dsisr = 0x%" PRIxPTR "\n",
392 frame->cpu.aim.dsisr);
393 break;
394 case EXC_ISE:
395 case EXC_ISI:
396 printf(" virtual address = 0x%" PRIxPTR "\n", frame->srr0);
397 break;
398 }
399 printf(" srr0 = 0x%" PRIxPTR "\n", frame->srr0);
400 printf(" srr1 = 0x%" PRIxPTR "\n", frame->srr1);
401 printf(" lr = 0x%" PRIxPTR "\n", frame->lr);
402 printf(" curthread = %p\n", curthread);
403 if (curthread != NULL)
404 printf(" pid = %d, comm = %s\n",
405 curthread->td_proc->p_pid, curthread->td_name);
406 printf("\n");
407 }
408
409 /*
410 * Handles a fatal fault when we have onfault state to recover. Returns
411 * non-zero if there was onfault recovery state available.
412 */
413 static int
handle_onfault(struct trapframe * frame)414 handle_onfault(struct trapframe *frame)
415 {
416 struct thread *td;
417 faultbuf *fb;
418
419 td = curthread;
420 fb = td->td_pcb->pcb_onfault;
421 if (fb != NULL) {
422 frame->srr0 = (*fb)[0];
423 frame->fixreg[1] = (*fb)[1];
424 frame->fixreg[2] = (*fb)[2];
425 frame->fixreg[3] = 1;
426 frame->cr = (*fb)[3];
427 bcopy(&(*fb)[4], &frame->fixreg[13],
428 19 * sizeof(register_t));
429 return (1);
430 }
431 return (0);
432 }
433
434 int
cpu_fetch_syscall_args(struct thread * td,struct syscall_args * sa)435 cpu_fetch_syscall_args(struct thread *td, struct syscall_args *sa)
436 {
437 struct proc *p;
438 struct trapframe *frame;
439 caddr_t params;
440 size_t argsz;
441 int error, n, i;
442
443 p = td->td_proc;
444 frame = td->td_frame;
445
446 sa->code = frame->fixreg[0];
447 params = (caddr_t)(frame->fixreg + FIRSTARG);
448 n = NARGREG;
449
450 if (sa->code == SYS_syscall) {
451 /*
452 * code is first argument,
453 * followed by actual args.
454 */
455 sa->code = *(register_t *) params;
456 params += sizeof(register_t);
457 n -= 1;
458 } else if (sa->code == SYS___syscall) {
459 /*
460 * Like syscall, but code is a quad,
461 * so as to maintain quad alignment
462 * for the rest of the args.
463 */
464 if (SV_PROC_FLAG(p, SV_ILP32)) {
465 params += sizeof(register_t);
466 sa->code = *(register_t *) params;
467 params += sizeof(register_t);
468 n -= 2;
469 } else {
470 sa->code = *(register_t *) params;
471 params += sizeof(register_t);
472 n -= 1;
473 }
474 }
475
476 if (p->p_sysent->sv_mask)
477 sa->code &= p->p_sysent->sv_mask;
478 if (sa->code >= p->p_sysent->sv_size)
479 sa->callp = &p->p_sysent->sv_table[0];
480 else
481 sa->callp = &p->p_sysent->sv_table[sa->code];
482
483 sa->narg = sa->callp->sy_narg;
484
485 if (SV_PROC_FLAG(p, SV_ILP32)) {
486 argsz = sizeof(uint32_t);
487
488 for (i = 0; i < n; i++)
489 sa->args[i] = ((u_register_t *)(params))[i] &
490 0xffffffff;
491 } else {
492 argsz = sizeof(uint64_t);
493
494 for (i = 0; i < n; i++)
495 sa->args[i] = ((u_register_t *)(params))[i];
496 }
497
498 if (sa->narg > n)
499 error = copyin(MOREARGS(frame->fixreg[1]), sa->args + n,
500 (sa->narg - n) * argsz);
501 else
502 error = 0;
503
504 #ifdef __powerpc64__
505 if (SV_PROC_FLAG(p, SV_ILP32) && sa->narg > n) {
506 /* Expand the size of arguments copied from the stack */
507
508 for (i = sa->narg; i >= n; i--)
509 sa->args[i] = ((uint32_t *)(&sa->args[n]))[i-n];
510 }
511 #endif
512
513 if (error == 0) {
514 td->td_retval[0] = 0;
515 td->td_retval[1] = frame->fixreg[FIRSTARG + 1];
516 }
517 return (error);
518 }
519
520 #include "../../kern/subr_syscall.c"
521
522 void
syscall(struct trapframe * frame)523 syscall(struct trapframe *frame)
524 {
525 struct thread *td;
526 struct syscall_args sa;
527 int error;
528
529 td = curthread;
530 td->td_frame = frame;
531
532 #ifdef __powerpc64__
533 /*
534 * Speculatively restore last user SLB segment, which we know is
535 * invalid already, since we are likely to do copyin()/copyout().
536 */
537 __asm __volatile ("slbmte %0, %1; isync" ::
538 "r"(td->td_pcb->pcb_cpu.aim.usr_vsid), "r"(USER_SLB_SLBE));
539 #endif
540
541 error = syscallenter(td, &sa);
542 syscallret(td, error, &sa);
543 }
544
545 #ifdef __powerpc64__
546 /* Handle kernel SLB faults -- runs in real mode, all seat belts off */
547 void
handle_kernel_slb_spill(int type,register_t dar,register_t srr0)548 handle_kernel_slb_spill(int type, register_t dar, register_t srr0)
549 {
550 struct slb *slbcache;
551 uint64_t slbe, slbv;
552 uint64_t esid, addr;
553 int i;
554
555 addr = (type == EXC_ISE) ? srr0 : dar;
556 slbcache = PCPU_GET(slb);
557 esid = (uintptr_t)addr >> ADDR_SR_SHFT;
558 slbe = (esid << SLBE_ESID_SHIFT) | SLBE_VALID;
559
560 /* See if the hardware flushed this somehow (can happen in LPARs) */
561 for (i = 0; i < n_slbs; i++)
562 if (slbcache[i].slbe == (slbe | (uint64_t)i))
563 return;
564
565 /* Not in the map, needs to actually be added */
566 slbv = kernel_va_to_slbv(addr);
567 if (slbcache[USER_SLB_SLOT].slbe == 0) {
568 for (i = 0; i < n_slbs; i++) {
569 if (i == USER_SLB_SLOT)
570 continue;
571 if (!(slbcache[i].slbe & SLBE_VALID))
572 goto fillkernslb;
573 }
574
575 if (i == n_slbs)
576 slbcache[USER_SLB_SLOT].slbe = 1;
577 }
578
579 /* Sacrifice a random SLB entry that is not the user entry */
580 i = mftb() % n_slbs;
581 if (i == USER_SLB_SLOT)
582 i = (i+1) % n_slbs;
583
584 fillkernslb:
585 /* Write new entry */
586 slbcache[i].slbv = slbv;
587 slbcache[i].slbe = slbe | (uint64_t)i;
588
589 /* Trap handler will restore from cache on exit */
590 }
591
592 static int
handle_user_slb_spill(pmap_t pm,vm_offset_t addr)593 handle_user_slb_spill(pmap_t pm, vm_offset_t addr)
594 {
595 struct slb *user_entry;
596 uint64_t esid;
597 int i;
598
599 esid = (uintptr_t)addr >> ADDR_SR_SHFT;
600
601 PMAP_LOCK(pm);
602 user_entry = user_va_to_slb_entry(pm, addr);
603
604 if (user_entry == NULL) {
605 /* allocate_vsid auto-spills it */
606 (void)allocate_user_vsid(pm, esid, 0);
607 } else {
608 /*
609 * Check that another CPU has not already mapped this.
610 * XXX: Per-thread SLB caches would be better.
611 */
612 for (i = 0; i < pm->pm_slb_len; i++)
613 if (pm->pm_slb[i] == user_entry)
614 break;
615
616 if (i == pm->pm_slb_len)
617 slb_insert_user(pm, user_entry);
618 }
619 PMAP_UNLOCK(pm);
620
621 return (0);
622 }
623 #endif
624
625 static int
trap_pfault(struct trapframe * frame,int user)626 trap_pfault(struct trapframe *frame, int user)
627 {
628 vm_offset_t eva, va;
629 struct thread *td;
630 struct proc *p;
631 vm_map_t map;
632 vm_prot_t ftype;
633 int rv;
634 register_t user_sr;
635
636 td = curthread;
637 p = td->td_proc;
638 if (frame->exc == EXC_ISI) {
639 eva = frame->srr0;
640 ftype = VM_PROT_EXECUTE;
641 if (frame->srr1 & SRR1_ISI_PFAULT)
642 ftype |= VM_PROT_READ;
643 } else {
644 eva = frame->cpu.aim.dar;
645 if (frame->cpu.aim.dsisr & DSISR_STORE)
646 ftype = VM_PROT_WRITE;
647 else
648 ftype = VM_PROT_READ;
649 }
650
651 if (user) {
652 map = &p->p_vmspace->vm_map;
653 } else {
654 if ((eva >> ADDR_SR_SHFT) == (USER_ADDR >> ADDR_SR_SHFT)) {
655 if (p->p_vmspace == NULL)
656 return (SIGSEGV);
657
658 map = &p->p_vmspace->vm_map;
659
660 user_sr = td->td_pcb->pcb_cpu.aim.usr_segm;
661 eva &= ADDR_PIDX | ADDR_POFF;
662 eva |= user_sr << ADDR_SR_SHFT;
663 } else {
664 map = kernel_map;
665 }
666 }
667 va = trunc_page(eva);
668
669 if (map != kernel_map) {
670 /*
671 * Keep swapout from messing with us during this
672 * critical time.
673 */
674 PROC_LOCK(p);
675 ++p->p_lock;
676 PROC_UNLOCK(p);
677
678 /* Fault in the user page: */
679 rv = vm_fault(map, va, ftype, VM_FAULT_NORMAL);
680
681 PROC_LOCK(p);
682 --p->p_lock;
683 PROC_UNLOCK(p);
684 /*
685 * XXXDTRACE: add dtrace_doubletrap_func here?
686 */
687 } else {
688 /*
689 * Don't have to worry about process locking or stacks in the
690 * kernel.
691 */
692 rv = vm_fault(map, va, ftype, VM_FAULT_NORMAL);
693 }
694
695 if (rv == KERN_SUCCESS)
696 return (0);
697
698 if (!user && handle_onfault(frame))
699 return (0);
700
701 return (SIGSEGV);
702 }
703
704 /*
705 * For now, this only deals with the particular unaligned access case
706 * that gcc tends to generate. Eventually it should handle all of the
707 * possibilities that can happen on a 32-bit PowerPC in big-endian mode.
708 */
709
710 static int
fix_unaligned(struct thread * td,struct trapframe * frame)711 fix_unaligned(struct thread *td, struct trapframe *frame)
712 {
713 struct thread *fputhread;
714 int indicator, reg;
715 double *fpr;
716
717 indicator = EXC_ALI_OPCODE_INDICATOR(frame->cpu.aim.dsisr);
718
719 switch (indicator) {
720 case EXC_ALI_LFD:
721 case EXC_ALI_STFD:
722 reg = EXC_ALI_RST(frame->cpu.aim.dsisr);
723 fpr = &td->td_pcb->pcb_fpu.fpr[reg];
724 fputhread = PCPU_GET(fputhread);
725
726 /* Juggle the FPU to ensure that we've initialized
727 * the FPRs, and that their current state is in
728 * the PCB.
729 */
730 if (fputhread != td) {
731 if (fputhread)
732 save_fpu(fputhread);
733 enable_fpu(td);
734 }
735 save_fpu(td);
736
737 if (indicator == EXC_ALI_LFD) {
738 if (copyin((void *)frame->cpu.aim.dar, fpr,
739 sizeof(double)) != 0)
740 return -1;
741 enable_fpu(td);
742 } else {
743 if (copyout(fpr, (void *)frame->cpu.aim.dar,
744 sizeof(double)) != 0)
745 return -1;
746 }
747 return 0;
748 break;
749 }
750
751 return -1;
752 }
753
754