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