ntoskrnl/include/internal/i386/ke.h

   1 #pragma once
   2
   3 #ifndef __ASM__
   4
   5 #include "intrin_i.h"
   6
   7 //
   8 // Thread Dispatcher Header DebugActive Mask
   9 //
  10 #define DR_MASK(x)                              (1 << (x))
  11 #define DR_REG_MASK                             0x4F
  12
  13 //
  14 // INT3 is 1 byte long
  15 //
  16 #define KD_BREAKPOINT_TYPE        UCHAR
  17 #define KD_BREAKPOINT_SIZE        sizeof(UCHAR)
  18 #define KD_BREAKPOINT_VALUE       0xCC
  19
  20 //
  21 // Macros for getting and setting special purpose registers in portable code
  22 //
  23 #define KeGetContextPc(Context) \
  24     ((Context)->Eip)
  25
  26 #define KeSetContextPc(Context, ProgramCounter) \
  27     ((Context)->Eip = (ProgramCounter))
  28
  29 #define KeGetTrapFramePc(TrapFrame) \
  30     ((TrapFrame)->Eip)
  31
  32 #define KiGetLinkedTrapFrame(x) \
  33     (PKTRAP_FRAME)((x)->Edx)
  34
  35 #define KeGetContextReturnRegister(Context) \
  36     ((Context)->Eax)
  37
  38 #define KeSetContextReturnRegister(Context, ReturnValue) \
  39     ((Context)->Eax = (ReturnValue))
  40
  41 //
  42 // Macro to get trap and exception frame from a thread stack
  43 //
  44 #define KeGetTrapFrame(Thread) \
  45     (PKTRAP_FRAME)((ULONG_PTR)((Thread)->InitialStack) - \
  46                    sizeof(KTRAP_FRAME) - \
  47                    sizeof(FX_SAVE_AREA))
  48
  49 #define KeGetExceptionFrame(Thread) \
  50     NULL
  51
  52 //
  53 // Macro to get context switches from the PRCB
  54 // All architectures but x86 have it in the PRCB's KeContextSwitches
  55 //
  56 #define KeGetContextSwitches(Prcb)  \
  57     CONTAINING_RECORD(Prcb, KIPCR, PrcbData)->ContextSwitches
  58
  59 //
  60 // Macro to get the second level cache size field name which differs between
  61 // CISC and RISC architectures, as the former has unified I/D cache
  62 //
  63 #define KiGetSecondLevelDCacheSize() ((PKIPCR)KeGetPcr())->SecondLevelCacheSize
  64
  65 //
  66 // Returns the Interrupt State from a Trap Frame.
  67 // ON = TRUE, OFF = FALSE
  68 //
  69 #define KeGetTrapFrameInterruptState(TrapFrame) \
  70         BooleanFlagOn((TrapFrame)->EFlags, EFLAGS_INTERRUPT_MASK)
  71
  72 //
  73 // Flags for exiting a trap
  74 //
  75 #define KTE_SKIP_PM_BIT  (((KTRAP_EXIT_SKIP_BITS) { { .SkipPreviousMode = TRUE } }).Bits)
  76 #define KTE_SKIP_SEG_BIT (((KTRAP_EXIT_SKIP_BITS) { { .SkipSegments  = TRUE } }).Bits)
  77 #define KTE_SKIP_VOL_BIT (((KTRAP_EXIT_SKIP_BITS) { { .SkipVolatiles = TRUE } }).Bits)
  78
  79 typedef union _KTRAP_EXIT_SKIP_BITS
  80 {
  81     struct
  82     {
  83         UCHAR SkipPreviousMode:1;
  84         UCHAR SkipSegments:1;
  85         UCHAR SkipVolatiles:1;
  86         UCHAR Reserved:5;
  87     };
  88     UCHAR Bits;
  89 } KTRAP_EXIT_SKIP_BITS, *PKTRAP_EXIT_SKIP_BITS;
  90
  91
  92 //
  93 // Flags used by the VDM/V8086 emulation engine for determining instruction prefixes
  94 //
  95 #define PFX_FLAG_ES                0x00000100
  96 #define PFX_FLAG_CS                0x00000200
  97 #define PFX_FLAG_SS                0x00000400
  98 #define PFX_FLAG_DS                0x00000800
  99 #define PFX_FLAG_FS                0x00001000
 100 #define PFX_FLAG_GS                0x00002000
 101 #define PFX_FLAG_OPER32            0x00004000
 102 #define PFX_FLAG_ADDR32            0x00008000
 103 #define PFX_FLAG_LOCK              0x00010000
 104 #define PFX_FLAG_REPNE             0x00020000
 105 #define PFX_FLAG_REP               0x00040000
 106
 107 //
 108 // VDM Helper Macros
 109 //
 110 // All VDM/V8086 opcode emulators have the same FASTCALL function definition.
 111 // We need to keep 2 parameters while the original ASM implementation uses 4:
 112 // TrapFrame, PrefixFlags, Eip, InstructionSize;
 113 //
 114 // We pass the trap frame, and prefix flags, in our two parameters.
 115 //
 116 // We then realize that since the smallest prefix flag is 0x100, this gives us
 117 // a count of up to 0xFF. So we OR in the instruction size with the prefix flags
 118 //
 119 // We further realize that we always have access to EIP from the trap frame, and
 120 // that if we want the *current instruction* EIP, we simply have to add the
 121 // instruction size *MINUS ONE*, and that gives us the EIP we should be looking
 122 // at now, so we don't need to use the stack to push this parameter.
 123 //
 124 // We actually only care about the *current instruction* EIP in one location,
 125 // so although it may be slightly more expensive to re-calculate the EIP one
 126 // more time, this way we don't redefine ALL opcode handlers to have 3 parameters,
 127 // which would be forcing stack usage in all other scenarios.
 128 //
 129 #define KiVdmSetVdmEFlags(x)        InterlockedOr((PLONG)KiNtVdmState, (x));
 130 #define KiVdmClearVdmEFlags(x)      InterlockedAnd((PLONG)KiNtVdmState, ~(x))
 131 #define KiCallVdmHandler(x)         KiVdmOpcode##x(TrapFrame, Flags)
 132 #define KiCallVdmPrefixHandler(x)   KiVdmOpcodePrefix(TrapFrame, Flags | x)
 133 #define KiVdmUnhandledOpcode(x)                     \
 134     BOOLEAN                                         \
 135     FASTCALL                                        \
 136     KiVdmOpcode##x(IN PKTRAP_FRAME TrapFrame,       \
 137                    IN ULONG Flags)                  \
 138     {                                               \
 139         /* Not yet handled */                       \
 140         UNIMPLEMENTED_DBGBREAK();                   \
 141         return FALSE;                               \
 142     }
 143
 144 C_ASSERT(NPX_FRAME_LENGTH == sizeof(FX_SAVE_AREA));
 145
 146 //
 147 // Local parameters
 148 //
 149 typedef struct _KV86_FRAME
 150 {
 151     PVOID ThreadStack;
 152     PVOID ThreadTeb;
 153     PVOID PcrTeb;
 154 } KV86_FRAME, *PKV86_FRAME;
 155
 156 //
 157 // Virtual Stack Frame
 158 //
 159 typedef struct _KV8086_STACK_FRAME
 160 {
 161     KTRAP_FRAME TrapFrame;
 162     FX_SAVE_AREA NpxArea;
 163     KV86_FRAME V86Frame;
 164 } KV8086_STACK_FRAME, *PKV8086_STACK_FRAME;
 165
 166 //
 167 // Large Pages Support
 168 //
 169 typedef struct _LARGE_IDENTITY_MAP
 170 {
 171     PHARDWARE_PTE TopLevelDirectory;
 172     ULONG Cr3;
 173     ULONG_PTR StartAddress;
 174     ULONG PagesCount;
 175     PVOID PagesList[30];
 176 } LARGE_IDENTITY_MAP, *PLARGE_IDENTITY_MAP;
 177
 178 /* Diable interrupts and return whether they were enabled before */
 179 FORCEINLINE
 180 BOOLEAN
 181 KeDisableInterrupts(VOID)
 182 {
 183     ULONG Flags;
 184     BOOLEAN Return;
 185
 186     /* Get EFLAGS and check if the interrupt bit is set */
 187     Flags = __readeflags();
 188     Return = (Flags & EFLAGS_INTERRUPT_MASK) ? TRUE: FALSE;
 189
 190     /* Disable interrupts */
 191     _disable();
 192     return Return;
 193 }
 194
 195 /* Restore previous interrupt state */
 196 FORCEINLINE
 197 VOID
 198 KeRestoreInterrupts(BOOLEAN WereEnabled)
 199 {
 200     if (WereEnabled) _enable();
 201 }
 202
 203 //
 204 // Registers an interrupt handler with an IDT vector
 205 //
 206 FORCEINLINE
 207 VOID
 208 KeRegisterInterruptHandler(IN ULONG Vector,
 209                            IN PVOID Handler)
 210 {
 211     UCHAR Entry;
 212     ULONG_PTR Address;
 213     PKIPCR Pcr = (PKIPCR)KeGetPcr();
 214
 215     //
 216     // Get the entry from the HAL
 217     //
 218     Entry = HalVectorToIDTEntry(Vector);
 219     Address = PtrToUlong(Handler);
 220
 221     //
 222     // Now set the data
 223     //
 224     Pcr->IDT[Entry].ExtendedOffset = (USHORT)(Address >> 16);
 225     Pcr->IDT[Entry].Offset = (USHORT)Address;
 226 }
 227
 228 //
 229 // Returns the registered interrupt handler for a given IDT vector
 230 //
 231 FORCEINLINE
 232 PVOID
 233 KeQueryInterruptHandler(IN ULONG Vector)
 234 {
 235     PKIPCR Pcr = (PKIPCR)KeGetPcr();
 236     UCHAR Entry;
 237
 238     //
 239     // Get the entry from the HAL
 240     //
 241     Entry = HalVectorToIDTEntry(Vector);
 242
 243     //
 244     // Read the entry from the IDT
 245     //
 246     return (PVOID)(((Pcr->IDT[Entry].ExtendedOffset << 16) & 0xFFFF0000) |
 247                     (Pcr->IDT[Entry].Offset & 0xFFFF));
 248 }
 249
 250 //
 251 // Invalidates the TLB entry for a specified address
 252 //
 253 FORCEINLINE
 254 VOID
 255 KeInvalidateTlbEntry(IN PVOID Address)
 256 {
 257     /* Invalidate the TLB entry for this address */
 258     __invlpg(Address);
 259 }
 260
 261 FORCEINLINE
 262 VOID
 263 KeFlushProcessTb(VOID)
 264 {
 265     /* Flush the TLB by resetting CR3 */
 266     __writecr3(__readcr3());
 267 }
 268
 269 FORCEINLINE
 270 PRKTHREAD
 271 KeGetCurrentThread(VOID)
 272 {
 273     /* Return the current thread */
 274     return ((PKIPCR)KeGetPcr())->PrcbData.CurrentThread;
 275 }
 276
 277 FORCEINLINE
 278 VOID
 279 KiRundownThread(IN PKTHREAD Thread)
 280 {
 281 #ifndef CONFIG_SMP
 282     /* Check if this is the NPX Thread */
 283     if (KeGetCurrentPrcb()->NpxThread == Thread)
 284     {
 285         /* Clear it */
 286         KeGetCurrentPrcb()->NpxThread = NULL;
 287         Ke386FnInit();
 288     }
 289 #else
 290     /* Nothing to do */
 291 #endif
 292 }
 293
 294 FORCEINLINE
 295 VOID
 296 Ke386SetGdtEntryBase(PKGDTENTRY GdtEntry, PVOID BaseAddress)
 297 {
 298     GdtEntry->BaseLow = (USHORT)((ULONG_PTR)BaseAddress & 0xFFFF);
 299     GdtEntry->HighWord.Bytes.BaseMid = (UCHAR)((ULONG_PTR)BaseAddress >> 16);
 300     GdtEntry->HighWord.Bytes.BaseHi = (UCHAR)((ULONG_PTR)BaseAddress >> 24);
 301 }
 302
 303 FORCEINLINE
 304 VOID
 305 KiSetTebBase(PKPCR Pcr, PVOID TebAddress)
 306 {
 307     Pcr->NtTib.Self = TebAddress;
 308     Ke386SetGdtEntryBase(&Pcr->GDT[KGDT_R3_TEB / sizeof(KGDTENTRY)], TebAddress);
 309 }
 310
 311 VOID
 312 FASTCALL
 313 Ki386InitializeTss(
 314     IN PKTSS Tss,
 315     IN PKIDTENTRY Idt,
 316     IN PKGDTENTRY Gdt
 317 );
 318
 319 VOID
 320 NTAPI
 321 KiSetCR0Bits(VOID);
 322
 323 VOID
 324 NTAPI
 325 KiGetCacheInformation(VOID);
 326
 327 BOOLEAN
 328 NTAPI
 329 KiIsNpxPresent(
 330     VOID
 331 );
 332
 333 BOOLEAN
 334 NTAPI
 335 KiIsNpxErrataPresent(
 336     VOID
 337 );
 338
 339 VOID
 340 NTAPI
 341 KiSetProcessorType(VOID);
 342
 343 ULONG
 344 NTAPI
 345 KiGetFeatureBits(VOID);
 346
 347 VOID
 348 NTAPI
 349 KiThreadStartup(VOID);
 350
 351 NTSTATUS
 352 NTAPI
 353 Ke386GetGdtEntryThread(
 354     IN PKTHREAD Thread,
 355     IN ULONG Offset,
 356     IN PKGDTENTRY Descriptor
 357 );
 358
 359 VOID
 360 NTAPI
 361 KiFlushNPXState(
 362     IN FLOATING_SAVE_AREA *SaveArea
 363 );
 364
 365 VOID
 366 NTAPI
 367 Ki386AdjustEsp0(
 368     IN PKTRAP_FRAME TrapFrame
 369 );
 370
 371 VOID
 372 NTAPI
 373 Ki386SetupAndExitToV86Mode(
 374     OUT PTEB VdmTeb
 375 );
 376
 377 VOID
 378 NTAPI
 379 KeI386VdmInitialize(
 380     VOID
 381 );
 382
 383 ULONG_PTR
 384 NTAPI
 385 Ki386EnableGlobalPage(
 386     IN ULONG_PTR Context
 387 );
 388
 389 ULONG_PTR
 390 NTAPI
 391 Ki386EnableTargetLargePage(
 392     IN ULONG_PTR Context
 393 );
 394
 395 BOOLEAN
 396 NTAPI
 397 Ki386CreateIdentityMap(
 398     IN PLARGE_IDENTITY_MAP IdentityMap,
 399     IN PVOID StartPtr,
 400     IN ULONG Length
 401 );
 402
 403 VOID
 404 NTAPI
 405 Ki386FreeIdentityMap(
 406     IN PLARGE_IDENTITY_MAP IdentityMap
 407 );
 408
 409 VOID
 410 NTAPI
 411 Ki386EnableCurrentLargePage(
 412     IN ULONG_PTR StartAddress,
 413     IN ULONG Cr3
 414 );
 415
 416 VOID
 417 NTAPI
 418 KiI386PentiumLockErrataFixup(
 419     VOID
 420 );
 421
 422 VOID
 423 NTAPI
 424 KiInitializePAT(
 425     VOID
 426 );
 427
 428 VOID
 429 NTAPI
 430 KiInitializeMTRR(
 431     IN BOOLEAN FinalCpu
 432 );
 433
 434 VOID
 435 NTAPI
 436 KiAmdK6InitializeMTRR(
 437     VOID
 438 );
 439
 440 VOID
 441 NTAPI
 442 KiRestoreFastSyscallReturnState(
 443     VOID
 444 );
 445
 446 ULONG_PTR
 447 NTAPI
 448 Ki386EnableDE(
 449     IN ULONG_PTR Context
 450 );
 451
 452 ULONG_PTR
 453 NTAPI
 454 Ki386EnableFxsr(
 455     IN ULONG_PTR Context
 456 );
 457
 458 ULONG_PTR
 459 NTAPI
 460 Ki386EnableXMMIExceptions(
 461     IN ULONG_PTR Context
 462 );
 463
 464 BOOLEAN
 465 NTAPI
 466 VdmDispatchBop(
 467     IN PKTRAP_FRAME TrapFrame
 468 );
 469
 470 BOOLEAN
 471 FASTCALL
 472 KiVdmOpcodePrefix(
 473     IN PKTRAP_FRAME TrapFrame,
 474     IN ULONG Flags
 475 );
 476
 477 BOOLEAN
 478 FASTCALL
 479 Ki386HandleOpcodeV86(
 480     IN PKTRAP_FRAME TrapFrame
 481 );
 482
 483 DECLSPEC_NORETURN
 484 VOID
 485 FASTCALL
 486 KiEoiHelper(
 487     IN PKTRAP_FRAME TrapFrame
 488 );
 489
 490 VOID
 491 FASTCALL
 492 Ki386BiosCallReturnAddress(
 493     IN PKTRAP_FRAME TrapFrame
 494 );
 495
 496 ULONG_PTR
 497 FASTCALL
 498 KiExitV86Mode(
 499     IN PKTRAP_FRAME TrapFrame
 500 );
 501
 502 DECLSPEC_NORETURN
 503 VOID
 504 NTAPI
 505 KiDispatchExceptionFromTrapFrame(
 506     IN NTSTATUS Code,
 507     IN ULONG_PTR Address,
 508     IN ULONG ParameterCount,
 509     IN ULONG_PTR Parameter1,
 510     IN ULONG_PTR Parameter2,
 511     IN ULONG_PTR Parameter3,
 512     IN PKTRAP_FRAME TrapFrame
 513 );
 514
 515 //
 516 // Global x86 only Kernel data
 517 //
 518 extern PVOID Ki386IopmSaveArea;
 519 extern ULONG KeI386EFlagsAndMaskV86;
 520 extern ULONG KeI386EFlagsOrMaskV86;
 521 extern BOOLEAN KeI386VirtualIntExtensions;
 522 extern KIDTENTRY KiIdt[MAXIMUM_IDTVECTOR+1];
 523 extern KDESCRIPTOR KiIdtDescriptor;
 524 extern BOOLEAN KiI386PentiumLockErrataPresent;
 525 extern ULONG KeI386NpxPresent;
 526 extern ULONG KeI386XMMIPresent;
 527 extern ULONG KeI386FxsrPresent;
 528 extern ULONG KiMXCsrMask;
 529 extern ULONG KeI386CpuType;
 530 extern ULONG KeI386CpuStep;
 531 extern ULONG Ke386CacheAlignment;
 532 extern ULONG KiFastSystemCallDisable;
 533 extern UCHAR KiDebugRegisterTrapOffsets[9];
 534 extern UCHAR KiDebugRegisterContextOffsets[9];
 535 extern DECLSPEC_NORETURN VOID __cdecl KiTrap02(VOID);
 536 extern VOID __cdecl KiTrap08(VOID);
 537 extern VOID __cdecl KiTrap13(VOID);
 538 extern VOID __cdecl KiFastCallEntry(VOID);
 539 extern VOID NTAPI ExpInterlockedPopEntrySListFault(VOID);
 540 extern VOID NTAPI ExpInterlockedPopEntrySListResume(VOID);
 541 extern VOID __cdecl CopyParams(VOID);
 542 extern VOID __cdecl ReadBatch(VOID);
 543 extern VOID __cdecl FrRestore(VOID);
 544 extern CHAR KiSystemCallExitBranch[];
 545 extern CHAR KiSystemCallExit[];
 546 extern CHAR KiSystemCallExit2[];
 547
 548 //
 549 // Trap Macros
 550 //
 551 #include "trap_x.h"
 552
 553 //
 554 // Returns a thread's FPU save area
 555 //
 556 FORCEINLINE
 557 PFX_SAVE_AREA
 558 KiGetThreadNpxArea(IN PKTHREAD Thread)
 559 {
 560     ASSERT((ULONG_PTR)Thread->InitialStack % 16 == 0);
 561     return (PFX_SAVE_AREA)((ULONG_PTR)Thread->InitialStack - sizeof(FX_SAVE_AREA));
 562 }
 563
 564 //
 565 // Sanitizes a selector
 566 //
 567 FORCEINLINE
 568 ULONG
 569 Ke386SanitizeSeg(IN ULONG Cs,
 570                 IN KPROCESSOR_MODE Mode)
 571 {
 572     //
 573     // Check if we're in kernel-mode, and force CPL 0 if so.
 574     // Otherwise, force CPL 3.
 575     //
 576     return ((Mode == KernelMode) ?
 577             (Cs & (0xFFFF & ~RPL_MASK)) :
 578             (RPL_MASK | (Cs & 0xFFFF)));
 579 }
 580
 581 //
 582 // Sanitizes EFLAGS
 583 //
 584 FORCEINLINE
 585 ULONG
 586 Ke386SanitizeFlags(IN ULONG Eflags,
 587                    IN KPROCESSOR_MODE Mode)
 588 {
 589     //
 590     // Check if we're in kernel-mode, and sanitize EFLAGS if so.
 591     // Otherwise, also force interrupt mask on.
 592     //
 593     return ((Mode == KernelMode) ?
 594             (Eflags & (EFLAGS_USER_SANITIZE | EFLAGS_INTERRUPT_MASK)) :
 595             (EFLAGS_INTERRUPT_MASK | (Eflags & EFLAGS_USER_SANITIZE)));
 596 }
 597
 598 //
 599 // Sanitizes a Debug Register
 600 //
 601 FORCEINLINE
 602 PVOID
 603 Ke386SanitizeDr(IN PVOID DrAddress,
 604                 IN KPROCESSOR_MODE Mode)
 605 {
 606     //
 607     // Check if we're in kernel-mode, and return the address directly if so.
 608     // Otherwise, make sure it's not inside the kernel-mode address space.
 609     // If it is, then clear the address.
 610     //
 611     return ((Mode == KernelMode) ? DrAddress :
 612             (DrAddress <= MM_HIGHEST_USER_ADDRESS) ? DrAddress : 0);
 613 }
 614
 615 //
 616 // Exception with no arguments
 617 //
 618 FORCEINLINE
 619 DECLSPEC_NORETURN
 620 VOID
 621 KiDispatchException0Args(IN NTSTATUS Code,
 622                          IN ULONG_PTR Address,
 623                          IN PKTRAP_FRAME TrapFrame)
 624 {
 625     /* Helper for exceptions with no arguments */
 626     KiDispatchExceptionFromTrapFrame(Code, Address, 0, 0, 0, 0, TrapFrame);
 627 }
 628
 629 //
 630 // Exception with one argument
 631 //
 632 FORCEINLINE
 633 DECLSPEC_NORETURN
 634 VOID
 635 KiDispatchException1Args(IN NTSTATUS Code,
 636                          IN ULONG_PTR Address,
 637                          IN ULONG P1,
 638                          IN PKTRAP_FRAME TrapFrame)
 639 {
 640     /* Helper for exceptions with no arguments */
 641     KiDispatchExceptionFromTrapFrame(Code, Address, 1, P1, 0, 0, TrapFrame);
 642 }
 643
 644 //
 645 // Exception with two arguments
 646 //
 647 FORCEINLINE
 648 DECLSPEC_NORETURN
 649 VOID
 650 KiDispatchException2Args(IN NTSTATUS Code,
 651                          IN ULONG_PTR Address,
 652                          IN ULONG P1,
 653                          IN ULONG P2,
 654                          IN PKTRAP_FRAME TrapFrame)
 655 {
 656     /* Helper for exceptions with no arguments */
 657     KiDispatchExceptionFromTrapFrame(Code, Address, 2, P1, P2, 0, TrapFrame);
 658 }
 659
 660 //
 661 // Performs a system call
 662 //
 663
 664     /*
 665      * This sequence does a RtlCopyMemory(Stack - StackBytes, Arguments, StackBytes)
 666      * and then calls the function associated with the system call.
 667      *
 668      * It's done in assembly for two reasons: we need to muck with the stack,
 669      * and the call itself restores the stack back for us. The only way to do
 670      * this in C is to do manual C handlers for every possible number of args on
 671      * the stack, and then have the handler issue a call by pointer. This is
 672      * wasteful since it'll basically push the values twice and require another
 673      * level of call indirection.
 674      *
 675      * The ARM kernel currently does this, but it should probably be changed
 676      * later to function like this as well.
 677      *
 678      */
 679 #ifdef __GNUC__
 680 FORCEINLINE
 681 NTSTATUS
 682 KiSystemCallTrampoline(IN PVOID Handler,
 683                        IN PVOID Arguments,
 684                        IN ULONG StackBytes)
 685 {
 686     NTSTATUS Result;
 687
 688     __asm__ __volatile__
 689     (
 690         "subl %1, %%esp\n"
 691         "movl %%esp, %%edi\n"
 692         "movl %2, %%esi\n"
 693         "shrl $2, %1\n"
 694         "rep movsd\n"
 695         "call *%3\n"
 696         "movl %%eax, %0\n"
 697         : "=r"(Result)
 698         : "c"(StackBytes),
 699           "d"(Arguments),
 700           "r"(Handler)
 701         : "%esp", "%esi", "%edi"
 702     );
 703     return Result;
 704 }
 705 #elif defined(_MSC_VER)
 706 FORCEINLINE
 707 NTSTATUS
 708 KiSystemCallTrampoline(IN PVOID Handler,
 709                        IN PVOID Arguments,
 710                        IN ULONG StackBytes)
 711 {
 712     __asm
 713     {
 714         mov ecx, StackBytes
 715         mov esi, Arguments
 716         mov eax, Handler
 717         sub esp, ecx
 718         mov edi, esp
 719         shr ecx, 2
 720         rep movsd
 721         call eax
 722     }
 723     /* Return with result in EAX */
 724 }
 725 #else
 726 #error Unknown Compiler
 727 #endif
 728
 729
 730 //
 731 // Checks for pending APCs
 732 //
 733 FORCEINLINE
 734 VOID
 735 KiCheckForApcDelivery(IN PKTRAP_FRAME TrapFrame)
 736 {
 737     PKTHREAD Thread;
 738     KIRQL OldIrql;
 739
 740     /* Check for V8086 or user-mode trap */
 741     if ((TrapFrame->EFlags & EFLAGS_V86_MASK) || (KiUserTrap(TrapFrame)))
 742     {
 743         /* Get the thread */
 744         Thread = KeGetCurrentThread();
 745         while (TRUE)
 746         {
 747             /* Turn off the alerted state for kernel mode */
 748             Thread->Alerted[KernelMode] = FALSE;
 749
 750             /* Are there pending user APCs? */
 751             if (!Thread->ApcState.UserApcPending) break;
 752
 753             /* Raise to APC level and enable interrupts */
 754             OldIrql = KfRaiseIrql(APC_LEVEL);
 755             _enable();
 756
 757             /* Deliver APCs */
 758             KiDeliverApc(UserMode, NULL, TrapFrame);
 759
 760             /* Restore IRQL and disable interrupts once again */
 761             KfLowerIrql(OldIrql);
 762             _disable();
 763         }
 764     }
 765 }
 766
 767 //
 768 // Converts a base thread to a GUI thread
 769 //
 770 #ifdef __GNUC__
 771 FORCEINLINE
 772 NTSTATUS
 773 KiConvertToGuiThread(VOID)
 774 {
 775     NTSTATUS Result;
 776     PVOID StackFrame;
 777
 778     /*
 779      * Converting to a GUI thread safely updates ESP in-place as well as the
 780      * current Thread->TrapFrame and EBP when KeSwitchKernelStack is called.
 781      *
 782      * However, PsConvertToGuiThread "helpfully" restores EBP to the original
 783      * caller's value, since it is considered a nonvolatile register. As such,
 784      * as soon as we're back after the conversion and we try to store the result
 785      * which will probably be in some stack variable (EBP-based), we'll crash as
 786      * we are touching the de-allocated non-expanded stack.
 787      *
 788      * Thus we need a way to update our EBP before EBP is touched, and the only
 789      * way to guarantee this is to do the call itself in assembly, use the EAX
 790      * register to store the result, fixup EBP, and then let the C code continue
 791      * on its merry way.
 792      *
 793      */
 794     __asm__ __volatile__
 795     (
 796         "movl %%ebp, %1\n\t"
 797         "subl %%esp, %1\n\t"
 798         "call _PsConvertToGuiThread@0\n\t"
 799         "addl %%esp, %1\n\t"
 800         "movl %1, %%ebp"
 801         : "=a"(Result), "=r"(StackFrame)
 802         :
 803         : "%esp", "%ecx", "%edx", "memory"
 804     );
 805     return Result;
 806 }
 807 #elif defined(_MSC_VER)
 808 NTSTATUS
 809 NTAPI
 810 KiConvertToGuiThread(VOID);
 811 #else
 812 #error Unknown Compiler
 813 #endif
 814
 815 //
 816 // Switches from boot loader to initial kernel stack
 817 //
 818 FORCEINLINE
 819 VOID
 820 KiSwitchToBootStack(IN ULONG_PTR InitialStack)
 821 {
 822     /* We have to switch to a new stack before continuing kernel initialization */
 823 #ifdef __GNUC__
 824     __asm__
 825     (
 826         "movl %0, %%esp\n"
 827         "subl %1, %%esp\n"
 828         "pushl %2\n"
 829         "jmp _KiSystemStartupBootStack@0\n"
 830         :
 831         : "c"(InitialStack),
 832           "i"(NPX_FRAME_LENGTH + KTRAP_FRAME_ALIGN + KTRAP_FRAME_LENGTH),
 833           "i"(CR0_EM | CR0_TS | CR0_MP)
 834         : "%esp"
 835     );
 836 #elif defined(_MSC_VER)
 837     VOID NTAPI KiSystemStartupBootStack(VOID);
 838     __asm
 839     {
 840         mov esp, InitialStack
 841         sub esp, (NPX_FRAME_LENGTH + KTRAP_FRAME_ALIGN + KTRAP_FRAME_LENGTH)
 842         push (CR0_EM | CR0_TS | CR0_MP)
 843         jmp KiSystemStartupBootStack
 844     }
 845 #else
 846 #error Unknown Compiler
 847 #endif
 848 }
 849
 850 //
 851 // Emits the iret instruction for C code
 852 //
 853 FORCEINLINE
 854 DECLSPEC_NORETURN
 855 VOID
 856 KiIret(VOID)
 857 {
 858 #if defined(__GNUC__)
 859     __asm__ __volatile__
 860     (
 861         "iret\n"
 862     );
 863 #elif defined(_MSC_VER)
 864     __asm
 865     {
 866         iretd
 867     }
 868 #else
 869 #error Unsupported compiler
 870 #endif
 871     UNREACHABLE;
 872 }
 873
 874 //
 875 // Normally this is done by the HAL, but on x86 as an optimization, the kernel
 876 // initiates the end by calling back into the HAL and exiting the trap here.
 877 //
 878 FORCEINLINE
 879 VOID
 880 KiEndInterrupt(IN KIRQL Irql,
 881                IN PKTRAP_FRAME TrapFrame)
 882 {
 883     /* Disable interrupts and end the interrupt */
 884     _disable();
 885     HalEndSystemInterrupt(Irql, TrapFrame);
 886
 887     /* Exit the interrupt */
 888     KiEoiHelper(TrapFrame);
 889 }
 890
 891 //
 892 // PERF Code
 893 //
 894 FORCEINLINE
 895 VOID
 896 Ki386PerfEnd(VOID)
 897 {
 898     extern ULONGLONG BootCyclesEnd, BootCycles;
 899     BootCyclesEnd = __rdtsc();
 900     DbgPrint("Boot took %I64u cycles!\n", BootCyclesEnd - BootCycles);
 901     DbgPrint("Interrupts: %u System Calls: %u Context Switches: %u\n",
 902              KeGetCurrentPrcb()->InterruptCount,
 903              KeGetCurrentPrcb()->KeSystemCalls,
 904              KeGetContextSwitches(KeGetCurrentPrcb()));
 905 }
 906
 907 FORCEINLINE
 908 PULONG
 909 KiGetUserModeStackAddress(void)
 910 {
 911     return &(KeGetCurrentThread()->TrapFrame->HardwareEsp);
 912 }
 913
 914 #endif