osfmk/i386/bsd_i386.c

   1 /*
   2  * Copyright (c) 2000-2016 Apple Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28 #ifdef  MACH_BSD
  29 #include <mach_rt.h>
  30 #include <mach_debug.h>
  31 #include <mach_ldebug.h>
  32
  33 #include <mach/kern_return.h>
  34 #include <mach/mach_traps.h>
  35 #include <mach/thread_status.h>
  36 #include <mach/vm_param.h>
  37
  38 #include <kern/counters.h>
  39 #include <kern/cpu_data.h>
  40 #include <kern/mach_param.h>
  41 #include <kern/task.h>
  42 #include <kern/thread.h>
  43 #include <kern/sched_prim.h>
  44 #include <kern/misc_protos.h>
  45 #include <kern/assert.h>
  46 #include <kern/debug.h>
  47 #include <kern/spl.h>
  48 #include <kern/syscall_sw.h>
  49 #include <ipc/ipc_port.h>
  50 #include <vm/vm_kern.h>
  51 #include <vm/pmap.h>
  52
  53 #include <i386/cpu_number.h>
  54 #include <i386/eflags.h>
  55 #include <i386/proc_reg.h>
  56 #include <i386/tss.h>
  57 #include <i386/user_ldt.h>
  58 #include <i386/fpu.h>
  59 #include <i386/machdep_call.h>
  60 #include <i386/vmparam.h>
  61 #include <i386/mp_desc.h>
  62 #include <i386/misc_protos.h>
  63 #include <i386/thread.h>
  64 #include <i386/trap.h>
  65 #include <i386/seg.h>
  66 #include <mach/i386/syscall_sw.h>
  67 #include <sys/syscall.h>
  68 #include <sys/kdebug.h>
  69 #include <sys/errno.h>
  70 #include <../bsd/sys/sysent.h>
  71
  72 #ifdef MACH_BSD
  73 extern void     mach_kauth_cred_uthread_update(void);
  74 extern void throttle_lowpri_io(int);
  75 #endif
  76
  77 void * find_user_regs(thread_t);
  78
  79 unsigned int get_msr_exportmask(void);
  80
  81 unsigned int get_msr_nbits(void);
  82
  83 unsigned int get_msr_rbits(void);
  84
  85 /*
  86  * thread_userstack:
  87  *
  88  * Return the user stack pointer from the machine
  89  * dependent thread state info.
  90  */
  91 kern_return_t
  92 thread_userstack(
  93     __unused thread_t   thread,
  94     int                 flavor,
  95     thread_state_t      tstate,
  96     __unused unsigned int        count,
  97     mach_vm_offset_t    *user_stack,
  98     int                 *customstack,
  99     __unused boolean_t  is64bit
 100 )
 101 {
 102         if (customstack)
 103                 *customstack = 0;
 104
 105         switch (flavor) {
 106         case x86_THREAD_STATE32:
 107                 {
 108                         x86_thread_state32_t *state25;
 109
 110                         state25 = (x86_thread_state32_t *) tstate;
 111
 112                         if (state25->esp) {
 113                                 *user_stack = state25->esp;
 114                                 if (customstack)
 115                                         *customstack = 1;
 116                         } else {
 117                                 *user_stack = VM_USRSTACK32;
 118                                 if (customstack)
 119                                         *customstack = 0;
 120                         }
 121                         break;
 122                 }
 123
 124         case x86_THREAD_STATE64:
 125                 {
 126                         x86_thread_state64_t *state25;
 127
 128                         state25 = (x86_thread_state64_t *) tstate;
 129
 130                         if (state25->rsp) {
 131                                 *user_stack = state25->rsp;
 132                                 if (customstack)
 133                                         *customstack = 1;
 134                         } else {
 135                                 *user_stack = VM_USRSTACK64;
 136                                 if (customstack)
 137                                         *customstack = 0;
 138                         }
 139                         break;
 140                 }
 141
 142         default:
 143                 return (KERN_INVALID_ARGUMENT);
 144         }
 145
 146         return (KERN_SUCCESS);
 147 }
 148
 149 /*
 150  * thread_userstackdefault:
 151  *
 152  * Return the default stack location for the
 153  * thread, if otherwise unknown.
 154  */
 155 kern_return_t
 156 thread_userstackdefault(
 157         mach_vm_offset_t *default_user_stack,
 158         boolean_t is64bit)
 159 {
 160         if (is64bit) {
 161                 *default_user_stack = VM_USRSTACK64;
 162         } else {
 163                 *default_user_stack = VM_USRSTACK32;
 164         }
 165         return (KERN_SUCCESS);
 166 }
 167
 168 kern_return_t
 169 thread_entrypoint(
 170     __unused thread_t   thread,
 171     int                 flavor,
 172     thread_state_t      tstate,
 173     __unused unsigned int        count,
 174     mach_vm_offset_t    *entry_point
 175 )
 176 {
 177         /*
 178          * Set a default.
 179          */
 180         if (*entry_point == 0)
 181                 *entry_point = VM_MIN_ADDRESS;
 182
 183         switch (flavor) {
 184         case x86_THREAD_STATE32:
 185                 {
 186                         x86_thread_state32_t *state25;
 187
 188                         state25 = (i386_thread_state_t *) tstate;
 189                         *entry_point = state25->eip ? state25->eip: VM_MIN_ADDRESS;
 190                         break;
 191                 }
 192
 193         case x86_THREAD_STATE64:
 194                 {
 195                         x86_thread_state64_t *state25;
 196
 197                         state25 = (x86_thread_state64_t *) tstate;
 198                         *entry_point = state25->rip ? state25->rip: VM_MIN_ADDRESS64;
 199                         break;
 200                 }
 201         }
 202         return (KERN_SUCCESS);
 203 }
 204
 205 /*
 206  * FIXME - thread_set_child
 207  */
 208
 209 void thread_set_child(thread_t child, int pid);
 210 void
 211 thread_set_child(thread_t child, int pid)
 212 {
 213         pal_register_cache_state(child, DIRTY);
 214
 215         if (thread_is_64bit(child)) {
 216                 x86_saved_state64_t     *iss64;
 217
 218                 iss64 = USER_REGS64(child);
 219
 220                 iss64->rax = pid;
 221                 iss64->rdx = 1;
 222                 iss64->isf.rflags &= ~EFL_CF;
 223         } else {
 224                 x86_saved_state32_t     *iss32;
 225
 226                 iss32 = USER_REGS32(child);
 227
 228                 iss32->eax = pid;
 229                 iss32->edx = 1;
 230                 iss32->efl &= ~EFL_CF;
 231         }
 232 }
 233
 234
 235
 236 /*
 237  * System Call handling code
 238  */
 239
 240 extern long fuword(vm_offset_t);
 241
 242 __attribute__((noreturn))
 243 void
 244 machdep_syscall(x86_saved_state_t *state)
 245 {
 246         int                     args[machdep_call_count];
 247         int                     trapno;
 248         int                     nargs;
 249         const machdep_call_t    *entry;
 250         x86_saved_state32_t     *regs;
 251
 252         assert(is_saved_state32(state));
 253         regs = saved_state32(state);
 254
 255         trapno = regs->eax;
 256 #if DEBUG_TRACE
 257         kprintf("machdep_syscall(0x%08x) code=%d\n", regs, trapno);
 258 #endif
 259
 260         DEBUG_KPRINT_SYSCALL_MDEP(
 261                 "machdep_syscall: trapno=%d\n", trapno);
 262
 263         if (trapno < 0 || trapno >= machdep_call_count) {
 264                 regs->eax = (unsigned int)kern_invalid(NULL);
 265
 266                 thread_exception_return();
 267                 /* NOTREACHED */
 268         }
 269         entry = &machdep_call_table[trapno];
 270         nargs = entry->nargs;
 271
 272         if (nargs != 0) {
 273                 if (copyin((user_addr_t) regs->uesp + sizeof (int),
 274                                 (char *) args, (nargs * sizeof (int)))) {
 275                         regs->eax = KERN_INVALID_ADDRESS;
 276
 277                         thread_exception_return();
 278                         /* NOTREACHED */
 279                 }
 280         }
 281         switch (nargs) {
 282         case 0:
 283                 regs->eax = (*entry->routine.args_0)();
 284                 break;
 285         case 1:
 286                 regs->eax = (*entry->routine.args_1)(args[0]);
 287                 break;
 288         case 2:
 289                 regs->eax = (*entry->routine.args_2)(args[0],args[1]);
 290                 break;
 291         case 3:
 292                 if (!entry->bsd_style)
 293                         regs->eax = (*entry->routine.args_3)(args[0],args[1],args[2]);
 294                 else {
 295                         int     error;
 296                         uint32_t        rval;
 297
 298                         error = (*entry->routine.args_bsd_3)(&rval, args[0], args[1], args[2]);
 299                         if (error) {
 300                                 regs->eax = error;
 301                                 regs->efl |= EFL_CF;    /* carry bit */
 302                         } else {
 303                                 regs->eax = rval;
 304                                 regs->efl &= ~EFL_CF;
 305                         }
 306                 }
 307                 break;
 308         case 4:
 309                 regs->eax = (*entry->routine.args_4)(args[0], args[1], args[2], args[3]);
 310                 break;
 311
 312         default:
 313                 panic("machdep_syscall: too many args");
 314         }
 315
 316         DEBUG_KPRINT_SYSCALL_MDEP("machdep_syscall: retval=%u\n", regs->eax);
 317
 318         throttle_lowpri_io(1);
 319
 320         thread_exception_return();
 321         /* NOTREACHED */
 322 }
 323
 324 __attribute__((noreturn))
 325 void
 326 machdep_syscall64(x86_saved_state_t *state)
 327 {
 328         int                     trapno;
 329         const machdep_call_t    *entry;
 330         x86_saved_state64_t     *regs;
 331
 332         assert(is_saved_state64(state));
 333         regs = saved_state64(state);
 334
 335         trapno = (int)(regs->rax & SYSCALL_NUMBER_MASK);
 336
 337         DEBUG_KPRINT_SYSCALL_MDEP(
 338                 "machdep_syscall64: trapno=%d\n", trapno);
 339
 340         if (trapno < 0 || trapno >= machdep_call_count) {
 341                 regs->rax = (unsigned int)kern_invalid(NULL);
 342
 343                 thread_exception_return();
 344                 /* NOTREACHED */
 345         }
 346         entry = &machdep_call_table64[trapno];
 347
 348         switch (entry->nargs) {
 349         case 0:
 350                 regs->rax = (*entry->routine.args_0)();
 351                 break;
 352         case 1:
 353                 regs->rax = (*entry->routine.args64_1)(regs->rdi);
 354                 break;
 355         case 2:
 356                 regs->rax = (*entry->routine.args64_2)(regs->rdi, regs->rsi);
 357                 break;
 358         default:
 359                 panic("machdep_syscall64: too many args");
 360         }
 361
 362         DEBUG_KPRINT_SYSCALL_MDEP("machdep_syscall: retval=%llu\n", regs->rax);
 363
 364         throttle_lowpri_io(1);
 365
 366         thread_exception_return();
 367         /* NOTREACHED */
 368 }
 369
 370 #endif  /* MACH_BSD */
 371
 372
 373 typedef kern_return_t (*mach_call_t)(void *);
 374
 375 struct mach_call_args {
 376         syscall_arg_t arg1;
 377         syscall_arg_t arg2;
 378         syscall_arg_t arg3;
 379         syscall_arg_t arg4;
 380         syscall_arg_t arg5;
 381         syscall_arg_t arg6;
 382         syscall_arg_t arg7;
 383         syscall_arg_t arg8;
 384         syscall_arg_t arg9;
 385 };
 386
 387 static kern_return_t
 388 mach_call_arg_munger32(uint32_t sp, struct mach_call_args *args, const mach_trap_t *trapp);
 389
 390
 391 static kern_return_t
 392 mach_call_arg_munger32(uint32_t sp, struct mach_call_args *args, const mach_trap_t *trapp)
 393 {
 394         if (copyin((user_addr_t)(sp + sizeof(int)), (char *)args, trapp->mach_trap_u32_words * sizeof (int)))
 395                 return KERN_INVALID_ARGUMENT;
 396 #if CONFIG_REQUIRES_U32_MUNGING
 397         trapp->mach_trap_arg_munge32(args);
 398 #else
 399 #error U32 mach traps on x86_64 kernel requires munging
 400 #endif
 401         return KERN_SUCCESS;
 402 }
 403
 404
 405 __private_extern__ void mach_call_munger(x86_saved_state_t *state);
 406
 407 extern const char *mach_syscall_name_table[];
 408
 409 __attribute__((noreturn))
 410 void
 411 mach_call_munger(x86_saved_state_t *state)
 412 {
 413         int argc;
 414         int call_number;
 415         mach_call_t mach_call;
 416         kern_return_t retval;
 417         struct mach_call_args args = { 0, 0, 0, 0, 0, 0, 0, 0, 0 };
 418         x86_saved_state32_t     *regs;
 419
 420 #if PROC_REF_DEBUG
 421         struct uthread *ut = get_bsdthread_info(current_thread());
 422
 423         uthread_reset_proc_refcount(ut);
 424 #endif
 425
 426         assert(is_saved_state32(state));
 427         regs = saved_state32(state);
 428
 429         call_number = -(regs->eax);
 430
 431         DEBUG_KPRINT_SYSCALL_MACH(
 432                 "mach_call_munger: code=%d(%s)\n",
 433                 call_number, mach_syscall_name_table[call_number]);
 434 #if DEBUG_TRACE
 435         kprintf("mach_call_munger(0x%08x) code=%d\n", regs, call_number);
 436 #endif
 437
 438         if (call_number < 0 || call_number >= mach_trap_count) {
 439                 i386_exception(EXC_SYSCALL, call_number, 1);
 440                 /* NOTREACHED */
 441         }
 442         mach_call = (mach_call_t)mach_trap_table[call_number].mach_trap_function;
 443
 444         if (mach_call == (mach_call_t)kern_invalid) {
 445                 DEBUG_KPRINT_SYSCALL_MACH(
 446                         "mach_call_munger: kern_invalid 0x%x\n", regs->eax);
 447                 i386_exception(EXC_SYSCALL, call_number, 1);
 448                 /* NOTREACHED */
 449         }
 450
 451         argc = mach_trap_table[call_number].mach_trap_arg_count;
 452         if (argc) {
 453                 retval = mach_call_arg_munger32(regs->uesp, &args,  &mach_trap_table[call_number]);
 454                 if (retval != KERN_SUCCESS) {
 455                         regs->eax = retval;
 456
 457                         DEBUG_KPRINT_SYSCALL_MACH(
 458                                 "mach_call_munger: retval=0x%x\n", retval);
 459
 460                         thread_exception_return();
 461                         /* NOTREACHED */
 462                 }
 463         }
 464
 465 #ifdef MACH_BSD
 466         mach_kauth_cred_uthread_update();
 467 #endif
 468
 469         KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
 470                 MACHDBG_CODE(DBG_MACH_EXCP_SC, (call_number)) | DBG_FUNC_START,
 471                 args.arg1, args.arg2, args.arg3, args.arg4, 0);
 472
 473         retval = mach_call(&args);
 474
 475         DEBUG_KPRINT_SYSCALL_MACH("mach_call_munger: retval=0x%x\n", retval);
 476
 477         KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
 478                 MACHDBG_CODE(DBG_MACH_EXCP_SC,(call_number)) | DBG_FUNC_END,
 479                 retval, 0, 0, 0, 0);
 480
 481         regs->eax = retval;
 482
 483         throttle_lowpri_io(1);
 484
 485 #if PROC_REF_DEBUG
 486         if (__improbable(uthread_get_proc_refcount(ut) != 0)) {
 487                 panic("system call returned with uu_proc_refcount != 0");
 488         }
 489 #endif
 490
 491         thread_exception_return();
 492         /* NOTREACHED */
 493 }
 494
 495
 496 __private_extern__ void mach_call_munger64(x86_saved_state_t *regs);
 497
 498 __attribute__((noreturn))
 499 void
 500 mach_call_munger64(x86_saved_state_t *state)
 501 {
 502         int call_number;
 503         int argc;
 504         mach_call_t mach_call;
 505         struct mach_call_args args = { 0, 0, 0, 0, 0, 0, 0, 0, 0 };
 506         x86_saved_state64_t     *regs;
 507
 508 #if PROC_REF_DEBUG
 509         struct uthread *ut = get_bsdthread_info(current_thread());
 510
 511         uthread_reset_proc_refcount(ut);
 512 #endif
 513
 514         assert(is_saved_state64(state));
 515         regs = saved_state64(state);
 516
 517         call_number = (int)(regs->rax & SYSCALL_NUMBER_MASK);
 518
 519         DEBUG_KPRINT_SYSCALL_MACH(
 520                 "mach_call_munger64: code=%d(%s)\n",
 521                 call_number, mach_syscall_name_table[call_number]);
 522
 523         KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
 524                 MACHDBG_CODE(DBG_MACH_EXCP_SC,(call_number)) | DBG_FUNC_START,
 525                 regs->rdi, regs->rsi, regs->rdx, regs->r10, 0);
 526
 527         if (call_number < 0 || call_number >= mach_trap_count) {
 528                 i386_exception(EXC_SYSCALL, regs->rax, 1);
 529                 /* NOTREACHED */
 530         }
 531         mach_call = (mach_call_t)mach_trap_table[call_number].mach_trap_function;
 532
 533         if (mach_call == (mach_call_t)kern_invalid) {
 534                 i386_exception(EXC_SYSCALL, regs->rax, 1);
 535                 /* NOTREACHED */
 536         }
 537         argc = mach_trap_table[call_number].mach_trap_arg_count;
 538         if (argc) {
 539                 int args_in_regs = MIN(6, argc);
 540
 541                 memcpy(&args.arg1, &regs->rdi, args_in_regs * sizeof(syscall_arg_t));
 542
 543                 if (argc > 6) {
 544                 int copyin_count;
 545
 546                         assert(argc <= 9);
 547                         copyin_count = (argc - 6) * (int)sizeof(syscall_arg_t);
 548
 549                 if (copyin((user_addr_t)(regs->isf.rsp + sizeof(user_addr_t)), (char *)&args.arg7, copyin_count)) {
 550                         regs->rax = KERN_INVALID_ARGUMENT;
 551
 552                                 thread_exception_return();
 553                                 /* NOTREACHED */
 554                         }
 555                 }
 556         }
 557
 558 #ifdef MACH_BSD
 559         mach_kauth_cred_uthread_update();
 560 #endif
 561
 562         regs->rax = (uint64_t)mach_call((void *)&args);
 563
 564         DEBUG_KPRINT_SYSCALL_MACH( "mach_call_munger64: retval=0x%llx\n", regs->rax);
 565
 566         KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
 567                 MACHDBG_CODE(DBG_MACH_EXCP_SC,(call_number)) | DBG_FUNC_END,
 568                 regs->rax, 0, 0, 0, 0);
 569
 570         throttle_lowpri_io(1);
 571
 572 #if PROC_REF_DEBUG
 573         if (__improbable(uthread_get_proc_refcount(ut) != 0)) {
 574                 panic("system call returned with uu_proc_refcount != 0");
 575         }
 576 #endif
 577
 578         thread_exception_return();
 579         /* NOTREACHED */
 580 }
 581
 582
 583 /*
 584  * thread_setuserstack:
 585  *
 586  * Sets the user stack pointer into the machine
 587  * dependent thread state info.
 588  */
 589 void
 590 thread_setuserstack(
 591         thread_t        thread,
 592         mach_vm_address_t       user_stack)
 593 {
 594         pal_register_cache_state(thread, DIRTY);
 595         if (thread_is_64bit(thread)) {
 596                 x86_saved_state64_t     *iss64;
 597
 598                 iss64 = USER_REGS64(thread);
 599
 600                 iss64->isf.rsp = (uint64_t)user_stack;
 601         } else {
 602                 x86_saved_state32_t     *iss32;
 603
 604                 iss32 = USER_REGS32(thread);
 605
 606                 iss32->uesp = CAST_DOWN_EXPLICIT(unsigned int, user_stack);
 607         }
 608 }
 609
 610 /*
 611  * thread_adjuserstack:
 612  *
 613  * Returns the adjusted user stack pointer from the machine
 614  * dependent thread state info.  Used for small (<2G) deltas.
 615  */
 616 uint64_t
 617 thread_adjuserstack(
 618         thread_t        thread,
 619         int             adjust)
 620 {
 621         pal_register_cache_state(thread, DIRTY);
 622         if (thread_is_64bit(thread)) {
 623                 x86_saved_state64_t     *iss64;
 624
 625                 iss64 = USER_REGS64(thread);
 626
 627                 iss64->isf.rsp += adjust;
 628
 629                 return iss64->isf.rsp;
 630         } else {
 631                 x86_saved_state32_t     *iss32;
 632
 633                 iss32 = USER_REGS32(thread);
 634
 635                 iss32->uesp += adjust;
 636
 637                 return CAST_USER_ADDR_T(iss32->uesp);
 638         }
 639 }
 640
 641 /*
 642  * thread_setentrypoint:
 643  *
 644  * Sets the user PC into the machine
 645  * dependent thread state info.
 646  */
 647 void
 648 thread_setentrypoint(thread_t thread, mach_vm_address_t entry)
 649 {
 650         pal_register_cache_state(thread, DIRTY);
 651         if (thread_is_64bit(thread)) {
 652                 x86_saved_state64_t     *iss64;
 653
 654                 iss64 = USER_REGS64(thread);
 655
 656                 iss64->isf.rip = (uint64_t)entry;
 657         } else {
 658                 x86_saved_state32_t     *iss32;
 659
 660                 iss32 = USER_REGS32(thread);
 661
 662                 iss32->eip = CAST_DOWN_EXPLICIT(unsigned int, entry);
 663         }
 664 }
 665
 666
 667 kern_return_t
 668 thread_setsinglestep(thread_t thread, int on)
 669 {
 670         pal_register_cache_state(thread, DIRTY);
 671         if (thread_is_64bit(thread)) {
 672                 x86_saved_state64_t     *iss64;
 673
 674                 iss64 = USER_REGS64(thread);
 675
 676                 if (on)
 677                         iss64->isf.rflags |= EFL_TF;
 678                 else
 679                         iss64->isf.rflags &= ~EFL_TF;
 680         } else {
 681                 x86_saved_state32_t     *iss32;
 682
 683                 iss32 = USER_REGS32(thread);
 684
 685                 if (on) {
 686                         iss32->efl |= EFL_TF;
 687                         /* Ensure IRET */
 688                         if (iss32->cs == SYSENTER_CS)
 689                                 iss32->cs = SYSENTER_TF_CS;
 690                 }
 691                 else
 692                         iss32->efl &= ~EFL_TF;
 693         }
 694
 695         return (KERN_SUCCESS);
 696 }
 697
 698 void *
 699 get_user_regs(thread_t th)
 700 {
 701         pal_register_cache_state(th, DIRTY);
 702         return(USER_STATE(th));
 703 }
 704
 705 void *
 706 find_user_regs(thread_t thread)
 707 {
 708         return get_user_regs(thread);
 709 }
 710
 711 #if CONFIG_DTRACE
 712 /*
 713  * DTrace would like to have a peek at the kernel interrupt state, if available.
 714  * Based on osfmk/chud/i386/chud_thread_i386.c:chudxnu_thread_get_state(), which see.
 715  */
 716 x86_saved_state_t *find_kern_regs(thread_t);
 717
 718 x86_saved_state_t *
 719 find_kern_regs(thread_t thread)
 720 {
 721         if (thread == current_thread() &&
 722                 NULL != current_cpu_datap()->cpu_int_state &&
 723                 !(USER_STATE(thread) == current_cpu_datap()->cpu_int_state &&
 724                   current_cpu_datap()->cpu_interrupt_level == 1)) {
 725
 726                 return current_cpu_datap()->cpu_int_state;
 727         } else {
 728                 return NULL;
 729         }
 730 }
 731
 732 vm_offset_t dtrace_get_cpu_int_stack_top(void);
 733
 734 vm_offset_t
 735 dtrace_get_cpu_int_stack_top(void)
 736 {
 737         return current_cpu_datap()->cpu_int_stack_top;
 738 }
 739 #endif