sys/powerpc/aim/trap.c

   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("$FreeBSD$");
  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 *
 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
 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, &regs);
 270                                         (*dtrace_pid_probe_ptr)(&regs);
 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
 358 trap_fatal(struct trapframe *frame)
 359 {
 360
 361         printtrap(frame->exc, frame, 1, (frame->srr1 & PSL_PR));
 362 #ifdef KDB
 363         if ((debugger_on_panic || kdb_active) &&
 364             kdb_trap(frame->exc, 0, frame))
 365                 return;
 366 #endif
 367         panic("%s trap", trapname(frame->exc));
 368 }
 369
 370 static void
 371 printtrap(u_int vector, struct trapframe *frame, int isfatal, int user)
 372 {
 373
 374         printf("\n");
 375         printf("%s %s trap:\n", isfatal ? "fatal" : "handled",
 376             user ? "user" : "kernel");
 377         printf("\n");
 378         printf("   exception       = 0x%x (%s)\n", vector, trapname(vector));
 379         switch (vector) {
 380         case EXC_DSE:
 381         case EXC_DSI:
 382                 printf("   virtual address = 0x%" PRIxPTR "\n",
 383                     frame->cpu.aim.dar);
 384                 printf("   dsisr           = 0x%" PRIxPTR "\n",
 385                     frame->cpu.aim.dsisr);
 386                 break;
 387         case EXC_ISE:
 388         case EXC_ISI:
 389                 printf("   virtual address = 0x%" PRIxPTR "\n", frame->srr0);
 390                 break;
 391         }
 392         printf("   srr0            = 0x%" PRIxPTR "\n", frame->srr0);
 393         printf("   srr1            = 0x%" PRIxPTR "\n", frame->srr1);
 394         printf("   lr              = 0x%" PRIxPTR "\n", frame->lr);
 395         printf("   curthread       = %p\n", curthread);
 396         if (curthread != NULL)
 397                 printf("          pid = %d, comm = %s\n",
 398                     curthread->td_proc->p_pid, curthread->td_name);
 399         printf("\n");
 400 }
 401
 402 /*
 403  * Handles a fatal fault when we have onfault state to recover.  Returns
 404  * non-zero if there was onfault recovery state available.
 405  */
 406 static int
 407 handle_onfault(struct trapframe *frame)
 408 {
 409         struct          thread *td;
 410         faultbuf        *fb;
 411
 412         td = curthread;
 413         fb = td->td_pcb->pcb_onfault;
 414         if (fb != NULL) {
 415                 frame->srr0 = (*fb)[0];
 416                 frame->fixreg[1] = (*fb)[1];
 417                 frame->fixreg[2] = (*fb)[2];
 418                 frame->fixreg[3] = 1;
 419                 frame->cr = (*fb)[3];
 420                 bcopy(&(*fb)[4], &frame->fixreg[13],
 421                     19 * sizeof(register_t));
 422                 return (1);
 423         }
 424         return (0);
 425 }
 426
 427 int
 428 cpu_fetch_syscall_args(struct thread *td, struct syscall_args *sa)
 429 {
 430         struct proc *p;
 431         struct trapframe *frame;
 432         caddr_t params;
 433         size_t argsz;
 434         int error, n, i;
 435
 436         p = td->td_proc;
 437         frame = td->td_frame;
 438
 439         sa->code = frame->fixreg[0];
 440         params = (caddr_t)(frame->fixreg + FIRSTARG);
 441         n = NARGREG;
 442
 443         if (sa->code == SYS_syscall) {
 444                 /*
 445                  * code is first argument,
 446                  * followed by actual args.
 447                  */
 448                 sa->code = *(register_t *) params;
 449                 params += sizeof(register_t);
 450                 n -= 1;
 451         } else if (sa->code == SYS___syscall) {
 452                 /*
 453                  * Like syscall, but code is a quad,
 454                  * so as to maintain quad alignment
 455                  * for the rest of the args.
 456                  */
 457                 if (SV_PROC_FLAG(p, SV_ILP32)) {
 458                         params += sizeof(register_t);
 459                         sa->code = *(register_t *) params;
 460                         params += sizeof(register_t);
 461                         n -= 2;
 462                 } else {
 463                         sa->code = *(register_t *) params;
 464                         params += sizeof(register_t);
 465                         n -= 1;
 466                 }
 467         }
 468
 469         if (p->p_sysent->sv_mask)
 470                 sa->code &= p->p_sysent->sv_mask;
 471         if (sa->code >= p->p_sysent->sv_size)
 472                 sa->callp = &p->p_sysent->sv_table[0];
 473         else
 474                 sa->callp = &p->p_sysent->sv_table[sa->code];
 475
 476         sa->narg = sa->callp->sy_narg;
 477
 478         if (SV_PROC_FLAG(p, SV_ILP32)) {
 479                 argsz = sizeof(uint32_t);
 480
 481                 for (i = 0; i < n; i++)
 482                         sa->args[i] = ((u_register_t *)(params))[i] &
 483                             0xffffffff;
 484         } else {
 485                 argsz = sizeof(uint64_t);
 486
 487                 for (i = 0; i < n; i++)
 488                         sa->args[i] = ((u_register_t *)(params))[i];
 489         }
 490
 491         if (sa->narg > n)
 492                 error = copyin(MOREARGS(frame->fixreg[1]), sa->args + n,
 493                                (sa->narg - n) * argsz);
 494         else
 495                 error = 0;
 496
 497 #ifdef __powerpc64__
 498         if (SV_PROC_FLAG(p, SV_ILP32) && sa->narg > n) {
 499                 /* Expand the size of arguments copied from the stack */
 500
 501                 for (i = sa->narg; i >= n; i--)
 502                         sa->args[i] = ((uint32_t *)(&sa->args[n]))[i-n];
 503         }
 504 #endif
 505
 506         if (error == 0) {
 507                 td->td_retval[0] = 0;
 508                 td->td_retval[1] = frame->fixreg[FIRSTARG + 1];
 509         }
 510         return (error);
 511 }
 512
 513 #include "../../kern/subr_syscall.c"
 514
 515 void
 516 syscall(struct trapframe *frame)
 517 {
 518         struct thread *td;
 519         struct syscall_args sa;
 520         int error;
 521
 522         td = curthread;
 523         td->td_frame = frame;
 524
 525 #ifdef __powerpc64__
 526         /*
 527          * Speculatively restore last user SLB segment, which we know is
 528          * invalid already, since we are likely to do copyin()/copyout().
 529          */
 530         __asm __volatile ("slbmte %0, %1; isync" ::
 531             "r"(td->td_pcb->pcb_cpu.aim.usr_vsid), "r"(USER_SLB_SLBE));
 532 #endif
 533
 534         error = syscallenter(td, &sa);
 535         syscallret(td, error, &sa);
 536 }
 537
 538 #ifdef __powerpc64__
 539 /* Handle kernel SLB faults -- runs in real mode, all seat belts off */
 540 void
 541 handle_kernel_slb_spill(int type, register_t dar, register_t srr0)
 542 {
 543         struct slb *slbcache;
 544         uint64_t slbe, slbv;
 545         uint64_t esid, addr;
 546         int i;
 547
 548         addr = (type == EXC_ISE) ? srr0 : dar;
 549         slbcache = PCPU_GET(slb);
 550         esid = (uintptr_t)addr >> ADDR_SR_SHFT;
 551         slbe = (esid << SLBE_ESID_SHIFT) | SLBE_VALID;
 552
 553         /* See if the hardware flushed this somehow (can happen in LPARs) */
 554         for (i = 0; i < n_slbs; i++)
 555                 if (slbcache[i].slbe == (slbe | (uint64_t)i))
 556                         return;
 557
 558         /* Not in the map, needs to actually be added */
 559         slbv = kernel_va_to_slbv(addr);
 560         if (slbcache[USER_SLB_SLOT].slbe == 0) {
 561                 for (i = 0; i < n_slbs; i++) {
 562                         if (i == USER_SLB_SLOT)
 563                                 continue;
 564                         if (!(slbcache[i].slbe & SLBE_VALID))
 565                                 goto fillkernslb;
 566                 }
 567
 568                 if (i == n_slbs)
 569                         slbcache[USER_SLB_SLOT].slbe = 1;
 570         }
 571
 572         /* Sacrifice a random SLB entry that is not the user entry */
 573         i = mftb() % n_slbs;
 574         if (i == USER_SLB_SLOT)
 575                 i = (i+1) % n_slbs;
 576
 577 fillkernslb:
 578         /* Write new entry */
 579         slbcache[i].slbv = slbv;
 580         slbcache[i].slbe = slbe | (uint64_t)i;
 581
 582         /* Trap handler will restore from cache on exit */
 583 }
 584
 585 static int
 586 handle_user_slb_spill(pmap_t pm, vm_offset_t addr)
 587 {
 588         struct slb *user_entry;
 589         uint64_t esid;
 590         int i;
 591
 592         esid = (uintptr_t)addr >> ADDR_SR_SHFT;
 593
 594         PMAP_LOCK(pm);
 595         user_entry = user_va_to_slb_entry(pm, addr);
 596
 597         if (user_entry == NULL) {
 598                 /* allocate_vsid auto-spills it */
 599                 (void)allocate_user_vsid(pm, esid, 0);
 600         } else {
 601                 /*
 602                  * Check that another CPU has not already mapped this.
 603                  * XXX: Per-thread SLB caches would be better.
 604                  */
 605                 for (i = 0; i < pm->pm_slb_len; i++)
 606                         if (pm->pm_slb[i] == user_entry)
 607                                 break;
 608
 609                 if (i == pm->pm_slb_len)
 610                         slb_insert_user(pm, user_entry);
 611         }
 612         PMAP_UNLOCK(pm);
 613
 614         return (0);
 615 }
 616 #endif
 617
 618 static int
 619 trap_pfault(struct trapframe *frame, int user)
 620 {
 621         vm_offset_t     eva, va;
 622         struct          thread *td;
 623         struct          proc *p;
 624         vm_map_t        map;
 625         vm_prot_t       ftype;
 626         int             rv;
 627         register_t      user_sr;
 628
 629         td = curthread;
 630         p = td->td_proc;
 631         if (frame->exc == EXC_ISI) {
 632                 eva = frame->srr0;
 633                 ftype = VM_PROT_EXECUTE;
 634                 if (frame->srr1 & SRR1_ISI_PFAULT)
 635                         ftype |= VM_PROT_READ;
 636         } else {
 637                 eva = frame->cpu.aim.dar;
 638                 if (frame->cpu.aim.dsisr & DSISR_STORE)
 639                         ftype = VM_PROT_WRITE;
 640                 else
 641                         ftype = VM_PROT_READ;
 642         }
 643
 644         if (user) {
 645                 map = &p->p_vmspace->vm_map;
 646         } else {
 647                 if ((eva >> ADDR_SR_SHFT) == (USER_ADDR >> ADDR_SR_SHFT)) {
 648                         if (p->p_vmspace == NULL)
 649                                 return (SIGSEGV);
 650
 651                         map = &p->p_vmspace->vm_map;
 652
 653                         user_sr = td->td_pcb->pcb_cpu.aim.usr_segm;
 654                         eva &= ADDR_PIDX | ADDR_POFF;
 655                         eva |= user_sr << ADDR_SR_SHFT;
 656                 } else {
 657                         map = kernel_map;
 658                 }
 659         }
 660         va = trunc_page(eva);
 661
 662         if (map != kernel_map) {
 663                 /*
 664                  * Keep swapout from messing with us during this
 665                  *      critical time.
 666                  */
 667                 PROC_LOCK(p);
 668                 ++p->p_lock;
 669                 PROC_UNLOCK(p);
 670
 671                 /* Fault in the user page: */
 672                 rv = vm_fault(map, va, ftype, VM_FAULT_NORMAL);
 673
 674                 PROC_LOCK(p);
 675                 --p->p_lock;
 676                 PROC_UNLOCK(p);
 677                 /*
 678                  * XXXDTRACE: add dtrace_doubletrap_func here?
 679                  */
 680         } else {
 681                 /*
 682                  * Don't have to worry about process locking or stacks in the
 683                  * kernel.
 684                  */
 685                 rv = vm_fault(map, va, ftype, VM_FAULT_NORMAL);
 686         }
 687
 688         if (rv == KERN_SUCCESS)
 689                 return (0);
 690
 691         if (!user && handle_onfault(frame))
 692                 return (0);
 693
 694         return (SIGSEGV);
 695 }
 696
 697 /*
 698  * For now, this only deals with the particular unaligned access case
 699  * that gcc tends to generate.  Eventually it should handle all of the
 700  * possibilities that can happen on a 32-bit PowerPC in big-endian mode.
 701  */
 702
 703 static int
 704 fix_unaligned(struct thread *td, struct trapframe *frame)
 705 {
 706         struct thread   *fputhread;
 707         int             indicator, reg;
 708         double          *fpr;
 709
 710         indicator = EXC_ALI_OPCODE_INDICATOR(frame->cpu.aim.dsisr);
 711
 712         switch (indicator) {
 713         case EXC_ALI_LFD:
 714         case EXC_ALI_STFD:
 715                 reg = EXC_ALI_RST(frame->cpu.aim.dsisr);
 716                 fpr = &td->td_pcb->pcb_fpu.fpr[reg];
 717                 fputhread = PCPU_GET(fputhread);
 718
 719                 /* Juggle the FPU to ensure that we've initialized
 720                  * the FPRs, and that their current state is in
 721                  * the PCB.
 722                  */
 723                 if (fputhread != td) {
 724                         if (fputhread)
 725                                 save_fpu(fputhread);
 726                         enable_fpu(td);
 727                 }
 728                 save_fpu(td);
 729
 730                 if (indicator == EXC_ALI_LFD) {
 731                         if (copyin((void *)frame->cpu.aim.dar, fpr,
 732                             sizeof(double)) != 0)
 733                                 return -1;
 734                         enable_fpu(td);
 735                 } else {
 736                         if (copyout(fpr, (void *)frame->cpu.aim.dar,
 737                             sizeof(double)) != 0)
 738                                 return -1;
 739                 }
 740                 return 0;
 741                 break;
 742         }
 743
 744         return -1;
 745 }
 746