trap.c revision 260667
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 260667 2014-01-15 04:16:45Z jhibbits $"); 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/uio.h> 52#include <sys/signalvar.h> 53#include <sys/vmmeter.h> 54 55#include <security/audit/audit.h> 56 57#include <vm/vm.h> 58#include <vm/pmap.h> 59#include <vm/vm_extern.h> 60#include <vm/vm_param.h> 61#include <vm/vm_kern.h> 62#include <vm/vm_map.h> 63#include <vm/vm_page.h> 64 65#include <machine/_inttypes.h> 66#include <machine/altivec.h> 67#include <machine/cpu.h> 68#include <machine/db_machdep.h> 69#include <machine/fpu.h> 70#include <machine/frame.h> 71#include <machine/pcb.h> 72#include <machine/pmap.h> 73#include <machine/psl.h> 74#include <machine/trap.h> 75#include <machine/spr.h> 76#include <machine/sr.h> 77 78static void trap_fatal(struct trapframe *frame); 79static void printtrap(u_int vector, struct trapframe *frame, int isfatal, 80 int user); 81static int trap_pfault(struct trapframe *frame, int user); 82static int fix_unaligned(struct thread *td, struct trapframe *frame); 83static int ppc_instr_emulate(struct trapframe *frame); 84static int handle_onfault(struct trapframe *frame); 85static void syscall(struct trapframe *frame); 86 87#ifdef __powerpc64__ 88 void handle_kernel_slb_spill(int, register_t, register_t); 89static int handle_user_slb_spill(pmap_t pm, vm_offset_t addr); 90extern int n_slbs; 91#endif 92 93int setfault(faultbuf); /* defined in locore.S */ 94 95/* Why are these not defined in a header? */ 96int badaddr(void *, size_t); 97int badaddr_read(void *, size_t, int *); 98 99struct powerpc_exception { 100 u_int vector; 101 char *name; 102}; 103 104#ifdef KDTRACE_HOOKS 105#include <sys/dtrace_bsd.h> 106 107/* 108 * This is a hook which is initialised by the dtrace module 109 * to handle traps which might occur during DTrace probe 110 * execution. 111 */ 112dtrace_trap_func_t dtrace_trap_func; 113 114dtrace_doubletrap_func_t dtrace_doubletrap_func; 115 116/* 117 * This is a hook which is initialised by the systrace module 118 * when it is loaded. This keeps the DTrace syscall provider 119 * implementation opaque. 120 */ 121systrace_probe_func_t systrace_probe_func; 122 123/* 124 * These hooks are necessary for the pid, usdt and fasttrap providers. 125 */ 126dtrace_fasttrap_probe_ptr_t dtrace_fasttrap_probe_ptr; 127dtrace_pid_probe_ptr_t dtrace_pid_probe_ptr; 128dtrace_return_probe_ptr_t dtrace_return_probe_ptr; 129int (*dtrace_invop_jump_addr)(struct trapframe *); 130#endif 131 132static struct powerpc_exception powerpc_exceptions[] = { 133 { 0x0100, "system reset" }, 134 { 0x0200, "machine check" }, 135 { 0x0300, "data storage interrupt" }, 136 { 0x0380, "data segment exception" }, 137 { 0x0400, "instruction storage interrupt" }, 138 { 0x0480, "instruction segment exception" }, 139 { 0x0500, "external interrupt" }, 140 { 0x0600, "alignment" }, 141 { 0x0700, "program" }, 142 { 0x0800, "floating-point unavailable" }, 143 { 0x0900, "decrementer" }, 144 { 0x0c00, "system call" }, 145 { 0x0d00, "trace" }, 146 { 0x0e00, "floating-point assist" }, 147 { 0x0f00, "performance monitoring" }, 148 { 0x0f20, "altivec unavailable" }, 149 { 0x1000, "instruction tlb miss" }, 150 { 0x1100, "data load tlb miss" }, 151 { 0x1200, "data store tlb miss" }, 152 { 0x1300, "instruction breakpoint" }, 153 { 0x1400, "system management" }, 154 { 0x1600, "altivec assist" }, 155 { 0x1700, "thermal management" }, 156 { 0x2000, "run mode/trace" }, 157 { 0x3000, NULL } 158}; 159 160static const char * 161trapname(u_int vector) 162{ 163 struct powerpc_exception *pe; 164 165 for (pe = powerpc_exceptions; pe->vector != 0x3000; pe++) { 166 if (pe->vector == vector) 167 return (pe->name); 168 } 169 170 return ("unknown"); 171} 172 173void 174trap(struct trapframe *frame) 175{ 176 struct thread *td; 177 struct proc *p; 178 int sig, type, user; 179 u_int ucode; 180 ksiginfo_t ksi; 181 182 PCPU_INC(cnt.v_trap); 183 184 td = curthread; 185 p = td->td_proc; 186 187 type = ucode = frame->exc; 188 sig = 0; 189 user = frame->srr1 & PSL_PR; 190 191 CTR3(KTR_TRAP, "trap: %s type=%s (%s)", td->td_name, 192 trapname(type), user ? "user" : "kernel"); 193 194#ifdef KDTRACE_HOOKS 195 /* 196 * A trap can occur while DTrace executes a probe. Before 197 * executing the probe, DTrace blocks re-scheduling and sets 198 * a flag in it's per-cpu flags to indicate that it doesn't 199 * want to fault. On returning from the probe, the no-fault 200 * flag is cleared and finally re-scheduling is enabled. 201 * 202 * If the DTrace kernel module has registered a trap handler, 203 * call it and if it returns non-zero, assume that it has 204 * handled the trap and modified the trap frame so that this 205 * function can return normally. 206 */ 207 /* 208 * XXXDTRACE: add fasttrap and pid probes handlers here (if ever) 209 */ 210 if (dtrace_trap_func != NULL && (*dtrace_trap_func)(frame, type)) 211 return; 212#endif 213 214 if (user) { 215 td->td_pticks = 0; 216 td->td_frame = frame; 217 if (td->td_ucred != p->p_ucred) 218 cred_update_thread(td); 219 220 /* User Mode Traps */ 221 switch (type) { 222 case EXC_RUNMODETRC: 223 case EXC_TRC: 224 frame->srr1 &= ~PSL_SE; 225 sig = SIGTRAP; 226 break; 227 228#ifdef __powerpc64__ 229 case EXC_ISE: 230 case EXC_DSE: 231 if (handle_user_slb_spill(&p->p_vmspace->vm_pmap, 232 (type == EXC_ISE) ? frame->srr0 : 233 frame->cpu.aim.dar) != 0) 234 sig = SIGSEGV; 235 break; 236#endif 237 case EXC_DSI: 238 case EXC_ISI: 239 sig = trap_pfault(frame, 1); 240 break; 241 242 case EXC_SC: 243 syscall(frame); 244 break; 245 246 case EXC_FPU: 247 KASSERT((td->td_pcb->pcb_flags & PCB_FPU) != PCB_FPU, 248 ("FPU already enabled for thread")); 249 enable_fpu(td); 250 break; 251 252 case EXC_VEC: 253 KASSERT((td->td_pcb->pcb_flags & PCB_VEC) != PCB_VEC, 254 ("Altivec already enabled for thread")); 255 enable_vec(td); 256 break; 257 258 case EXC_VECAST_G4: 259 case EXC_VECAST_G5: 260 /* 261 * We get a VPU assist exception for IEEE mode 262 * vector operations on denormalized floats. 263 * Emulating this is a giant pain, so for now, 264 * just switch off IEEE mode and treat them as 265 * zero. 266 */ 267 268 save_vec(td); 269 td->td_pcb->pcb_vec.vscr |= ALTIVEC_VSCR_NJ; 270 enable_vec(td); 271 break; 272 273 case EXC_ALI: 274 if (fix_unaligned(td, frame) != 0) 275 sig = SIGBUS; 276 else 277 frame->srr0 += 4; 278 break; 279 280 case EXC_PGM: 281 /* Identify the trap reason */ 282 if (frame->srr1 & EXC_PGM_TRAP) 283 sig = SIGTRAP; 284 else if (ppc_instr_emulate(frame) == 0) 285 frame->srr0 += 4; 286 else 287 sig = SIGILL; 288 break; 289 290 default: 291 trap_fatal(frame); 292 } 293 } else { 294 /* Kernel Mode Traps */ 295 296 KASSERT(cold || td->td_ucred != NULL, 297 ("kernel trap doesn't have ucred")); 298 switch (type) { 299#ifdef KDTRACE_HOOKS 300 case EXC_PGM: 301 if (frame->srr1 & EXC_PGM_TRAP) { 302 if (*(uintptr_t *)frame->srr0 == 0x7c810808) { 303 if (dtrace_invop_jump_addr != NULL) { 304 dtrace_invop_jump_addr(frame); 305 return; 306 } 307 } 308 } 309 break; 310#endif 311#ifdef __powerpc64__ 312 case EXC_DSE: 313 if ((frame->cpu.aim.dar & SEGMENT_MASK) == USER_ADDR) { 314 __asm __volatile ("slbmte %0, %1" :: 315 "r"(td->td_pcb->pcb_cpu.aim.usr_vsid), 316 "r"(USER_SLB_SLBE)); 317 return; 318 } 319 break; 320#endif 321 case EXC_DSI: 322 if (trap_pfault(frame, 0) == 0) 323 return; 324 break; 325 case EXC_MCHK: 326 if (handle_onfault(frame)) 327 return; 328 break; 329 default: 330 break; 331 } 332 trap_fatal(frame); 333 } 334 335 if (sig != 0) { 336 if (p->p_sysent->sv_transtrap != NULL) 337 sig = (p->p_sysent->sv_transtrap)(sig, type); 338 ksiginfo_init_trap(&ksi); 339 ksi.ksi_signo = sig; 340 ksi.ksi_code = (int) ucode; /* XXX, not POSIX */ 341 /* ksi.ksi_addr = ? */ 342 ksi.ksi_trapno = type; 343 trapsignal(td, &ksi); 344 } 345 346 userret(td, frame); 347} 348 349static void 350trap_fatal(struct trapframe *frame) 351{ 352 353 printtrap(frame->exc, frame, 1, (frame->srr1 & PSL_PR)); 354#ifdef KDB 355 if ((debugger_on_panic || kdb_active) && 356 kdb_trap(frame->exc, 0, frame)) 357 return; 358#endif 359 panic("%s trap", trapname(frame->exc)); 360} 361 362static void 363printtrap(u_int vector, struct trapframe *frame, int isfatal, int user) 364{ 365 366 printf("\n"); 367 printf("%s %s trap:\n", isfatal ? "fatal" : "handled", 368 user ? "user" : "kernel"); 369 printf("\n"); 370 printf(" exception = 0x%x (%s)\n", vector, trapname(vector)); 371 switch (vector) { 372 case EXC_DSE: 373 case EXC_DSI: 374 printf(" virtual address = 0x%" PRIxPTR "\n", 375 frame->cpu.aim.dar); 376 printf(" dsisr = 0x%" PRIxPTR "\n", 377 frame->cpu.aim.dsisr); 378 break; 379 case EXC_ISE: 380 case EXC_ISI: 381 printf(" virtual address = 0x%" PRIxPTR "\n", frame->srr0); 382 break; 383 } 384 printf(" srr0 = 0x%" PRIxPTR "\n", frame->srr0); 385 printf(" srr1 = 0x%" PRIxPTR "\n", frame->srr1); 386 printf(" lr = 0x%" PRIxPTR "\n", frame->lr); 387 printf(" curthread = %p\n", curthread); 388 if (curthread != NULL) 389 printf(" pid = %d, comm = %s\n", 390 curthread->td_proc->p_pid, curthread->td_name); 391 printf("\n"); 392} 393 394/* 395 * Handles a fatal fault when we have onfault state to recover. Returns 396 * non-zero if there was onfault recovery state available. 397 */ 398static int 399handle_onfault(struct trapframe *frame) 400{ 401 struct thread *td; 402 faultbuf *fb; 403 404 td = curthread; 405 fb = td->td_pcb->pcb_onfault; 406 if (fb != NULL) { 407 frame->srr0 = (*fb)[0]; 408 frame->fixreg[1] = (*fb)[1]; 409 frame->fixreg[2] = (*fb)[2]; 410 frame->fixreg[3] = 1; 411 frame->cr = (*fb)[3]; 412 bcopy(&(*fb)[4], &frame->fixreg[13], 413 19 * sizeof(register_t)); 414 return (1); 415 } 416 return (0); 417} 418 419int 420cpu_fetch_syscall_args(struct thread *td, struct syscall_args *sa) 421{ 422 struct proc *p; 423 struct trapframe *frame; 424 caddr_t params; 425 size_t argsz; 426 int error, n, i; 427 428 p = td->td_proc; 429 frame = td->td_frame; 430 431 sa->code = frame->fixreg[0]; 432 params = (caddr_t)(frame->fixreg + FIRSTARG); 433 n = NARGREG; 434 435 if (sa->code == SYS_syscall) { 436 /* 437 * code is first argument, 438 * followed by actual args. 439 */ 440 sa->code = *(register_t *) params; 441 params += sizeof(register_t); 442 n -= 1; 443 } else if (sa->code == SYS___syscall) { 444 /* 445 * Like syscall, but code is a quad, 446 * so as to maintain quad alignment 447 * for the rest of the args. 448 */ 449 if (SV_PROC_FLAG(p, SV_ILP32)) { 450 params += sizeof(register_t); 451 sa->code = *(register_t *) params; 452 params += sizeof(register_t); 453 n -= 2; 454 } else { 455 sa->code = *(register_t *) params; 456 params += sizeof(register_t); 457 n -= 1; 458 } 459 } 460 461 if (p->p_sysent->sv_mask) 462 sa->code &= p->p_sysent->sv_mask; 463 if (sa->code >= p->p_sysent->sv_size) 464 sa->callp = &p->p_sysent->sv_table[0]; 465 else 466 sa->callp = &p->p_sysent->sv_table[sa->code]; 467 468 sa->narg = sa->callp->sy_narg; 469 470 if (SV_PROC_FLAG(p, SV_ILP32)) { 471 argsz = sizeof(uint32_t); 472 473 for (i = 0; i < n; i++) 474 sa->args[i] = ((u_register_t *)(params))[i] & 475 0xffffffff; 476 } else { 477 argsz = sizeof(uint64_t); 478 479 for (i = 0; i < n; i++) 480 sa->args[i] = ((u_register_t *)(params))[i]; 481 } 482 483 if (sa->narg > n) 484 error = copyin(MOREARGS(frame->fixreg[1]), sa->args + n, 485 (sa->narg - n) * argsz); 486 else 487 error = 0; 488 489#ifdef __powerpc64__ 490 if (SV_PROC_FLAG(p, SV_ILP32) && sa->narg > n) { 491 /* Expand the size of arguments copied from the stack */ 492 493 for (i = sa->narg; i >= n; i--) 494 sa->args[i] = ((uint32_t *)(&sa->args[n]))[i-n]; 495 } 496#endif 497 498 if (error == 0) { 499 td->td_retval[0] = 0; 500 td->td_retval[1] = frame->fixreg[FIRSTARG + 1]; 501 } 502 return (error); 503} 504 505#include "../../kern/subr_syscall.c" 506 507void 508syscall(struct trapframe *frame) 509{ 510 struct thread *td; 511 struct syscall_args sa; 512 int error; 513 514 td = curthread; 515 td->td_frame = frame; 516 517#ifdef __powerpc64__ 518 /* 519 * Speculatively restore last user SLB segment, which we know is 520 * invalid already, since we are likely to do copyin()/copyout(). 521 */ 522 __asm __volatile ("slbmte %0, %1; isync" :: 523 "r"(td->td_pcb->pcb_cpu.aim.usr_vsid), "r"(USER_SLB_SLBE)); 524#endif 525 526 error = syscallenter(td, &sa); 527 syscallret(td, error, &sa); 528} 529 530#ifdef __powerpc64__ 531/* Handle kernel SLB faults -- runs in real mode, all seat belts off */ 532void 533handle_kernel_slb_spill(int type, register_t dar, register_t srr0) 534{ 535 struct slb *slbcache; 536 uint64_t slbe, slbv; 537 uint64_t esid, addr; 538 int i; 539 540 addr = (type == EXC_ISE) ? srr0 : dar; 541 slbcache = PCPU_GET(slb); 542 esid = (uintptr_t)addr >> ADDR_SR_SHFT; 543 slbe = (esid << SLBE_ESID_SHIFT) | SLBE_VALID; 544 545 /* See if the hardware flushed this somehow (can happen in LPARs) */ 546 for (i = 0; i < n_slbs; i++) 547 if (slbcache[i].slbe == (slbe | (uint64_t)i)) 548 return; 549 550 /* Not in the map, needs to actually be added */ 551 slbv = kernel_va_to_slbv(addr); 552 if (slbcache[USER_SLB_SLOT].slbe == 0) { 553 for (i = 0; i < n_slbs; i++) { 554 if (i == USER_SLB_SLOT) 555 continue; 556 if (!(slbcache[i].slbe & SLBE_VALID)) 557 goto fillkernslb; 558 } 559 560 if (i == n_slbs) 561 slbcache[USER_SLB_SLOT].slbe = 1; 562 } 563 564 /* Sacrifice a random SLB entry that is not the user entry */ 565 i = mftb() % n_slbs; 566 if (i == USER_SLB_SLOT) 567 i = (i+1) % n_slbs; 568 569fillkernslb: 570 /* Write new entry */ 571 slbcache[i].slbv = slbv; 572 slbcache[i].slbe = slbe | (uint64_t)i; 573 574 /* Trap handler will restore from cache on exit */ 575} 576 577static int 578handle_user_slb_spill(pmap_t pm, vm_offset_t addr) 579{ 580 struct slb *user_entry; 581 uint64_t esid; 582 int i; 583 584 esid = (uintptr_t)addr >> ADDR_SR_SHFT; 585 586 PMAP_LOCK(pm); 587 user_entry = user_va_to_slb_entry(pm, addr); 588 589 if (user_entry == NULL) { 590 /* allocate_vsid auto-spills it */ 591 (void)allocate_user_vsid(pm, esid, 0); 592 } else { 593 /* 594 * Check that another CPU has not already mapped this. 595 * XXX: Per-thread SLB caches would be better. 596 */ 597 for (i = 0; i < pm->pm_slb_len; i++) 598 if (pm->pm_slb[i] == user_entry) 599 break; 600 601 if (i == pm->pm_slb_len) 602 slb_insert_user(pm, user_entry); 603 } 604 PMAP_UNLOCK(pm); 605 606 return (0); 607} 608#endif 609 610static int 611trap_pfault(struct trapframe *frame, int user) 612{ 613 vm_offset_t eva, va; 614 struct thread *td; 615 struct proc *p; 616 vm_map_t map; 617 vm_prot_t ftype; 618 int rv; 619 register_t user_sr; 620 621 td = curthread; 622 p = td->td_proc; 623 if (frame->exc == EXC_ISI) { 624 eva = frame->srr0; 625 ftype = VM_PROT_EXECUTE; 626 if (frame->srr1 & SRR1_ISI_PFAULT) 627 ftype |= VM_PROT_READ; 628 } else { 629 eva = frame->cpu.aim.dar; 630 if (frame->cpu.aim.dsisr & DSISR_STORE) 631 ftype = VM_PROT_WRITE; 632 else 633 ftype = VM_PROT_READ; 634 } 635 636 if (user) { 637 map = &p->p_vmspace->vm_map; 638 } else { 639 if ((eva >> ADDR_SR_SHFT) == (USER_ADDR >> ADDR_SR_SHFT)) { 640 if (p->p_vmspace == NULL) 641 return (SIGSEGV); 642 643 map = &p->p_vmspace->vm_map; 644 645 user_sr = td->td_pcb->pcb_cpu.aim.usr_segm; 646 eva &= ADDR_PIDX | ADDR_POFF; 647 eva |= user_sr << ADDR_SR_SHFT; 648 } else { 649 map = kernel_map; 650 } 651 } 652 va = trunc_page(eva); 653 654 if (map != kernel_map) { 655 /* 656 * Keep swapout from messing with us during this 657 * critical time. 658 */ 659 PROC_LOCK(p); 660 ++p->p_lock; 661 PROC_UNLOCK(p); 662 663 /* Fault in the user page: */ 664 rv = vm_fault(map, va, ftype, VM_FAULT_NORMAL); 665 666 PROC_LOCK(p); 667 --p->p_lock; 668 PROC_UNLOCK(p); 669 /* 670 * XXXDTRACE: add dtrace_doubletrap_func here? 671 */ 672 } else { 673 /* 674 * Don't have to worry about process locking or stacks in the 675 * kernel. 676 */ 677 rv = vm_fault(map, va, ftype, VM_FAULT_NORMAL); 678 } 679 680 if (rv == KERN_SUCCESS) 681 return (0); 682 683 if (!user && handle_onfault(frame)) 684 return (0); 685 686 return (SIGSEGV); 687} 688 689int 690badaddr(void *addr, size_t size) 691{ 692 return (badaddr_read(addr, size, NULL)); 693} 694 695int 696badaddr_read(void *addr, size_t size, int *rptr) 697{ 698 struct thread *td; 699 faultbuf env; 700 int x; 701 702 /* Get rid of any stale machine checks that have been waiting. */ 703 __asm __volatile ("sync; isync"); 704 705 td = curthread; 706 707 if (setfault(env)) { 708 td->td_pcb->pcb_onfault = 0; 709 __asm __volatile ("sync"); 710 return 1; 711 } 712 713 __asm __volatile ("sync"); 714 715 switch (size) { 716 case 1: 717 x = *(volatile int8_t *)addr; 718 break; 719 case 2: 720 x = *(volatile int16_t *)addr; 721 break; 722 case 4: 723 x = *(volatile int32_t *)addr; 724 break; 725 default: 726 panic("badaddr: invalid size (%zd)", size); 727 } 728 729 /* Make sure we took the machine check, if we caused one. */ 730 __asm __volatile ("sync; isync"); 731 732 td->td_pcb->pcb_onfault = 0; 733 __asm __volatile ("sync"); /* To be sure. */ 734 735 /* Use the value to avoid reorder. */ 736 if (rptr) 737 *rptr = x; 738 739 return (0); 740} 741 742/* 743 * For now, this only deals with the particular unaligned access case 744 * that gcc tends to generate. Eventually it should handle all of the 745 * possibilities that can happen on a 32-bit PowerPC in big-endian mode. 746 */ 747 748static int 749fix_unaligned(struct thread *td, struct trapframe *frame) 750{ 751 struct thread *fputhread; 752 int indicator, reg; 753 double *fpr; 754 755 indicator = EXC_ALI_OPCODE_INDICATOR(frame->cpu.aim.dsisr); 756 757 switch (indicator) { 758 case EXC_ALI_LFD: 759 case EXC_ALI_STFD: 760 reg = EXC_ALI_RST(frame->cpu.aim.dsisr); 761 fpr = &td->td_pcb->pcb_fpu.fpr[reg]; 762 fputhread = PCPU_GET(fputhread); 763 764 /* Juggle the FPU to ensure that we've initialized 765 * the FPRs, and that their current state is in 766 * the PCB. 767 */ 768 if (fputhread != td) { 769 if (fputhread) 770 save_fpu(fputhread); 771 enable_fpu(td); 772 } 773 save_fpu(td); 774 775 if (indicator == EXC_ALI_LFD) { 776 if (copyin((void *)frame->cpu.aim.dar, fpr, 777 sizeof(double)) != 0) 778 return -1; 779 enable_fpu(td); 780 } else { 781 if (copyout(fpr, (void *)frame->cpu.aim.dar, 782 sizeof(double)) != 0) 783 return -1; 784 } 785 return 0; 786 break; 787 } 788 789 return -1; 790} 791 792static int 793ppc_instr_emulate(struct trapframe *frame) 794{ 795 uint32_t instr; 796 int reg; 797 798 instr = fuword32((void *)frame->srr0); 799 800 if ((instr & 0xfc1fffff) == 0x7c1f42a6) { /* mfpvr */ 801 reg = (instr & ~0xfc1fffff) >> 21; 802 frame->fixreg[reg] = mfpvr(); 803 return (0); 804 } 805 806 return (-1); 807} 808 809