VEX/priv/guest_x86_defs.h

   1
   2 /*---------------------------------------------------------------*/
   3 /*--- begin                                  guest_x86_defs.h ---*/
   4 /*---------------------------------------------------------------*/
   5
   6 /*
   7    This file is part of Valgrind, a dynamic binary instrumentation
   8    framework.
   9
  10    Copyright (C) 2004-2017 OpenWorks LLP
  11       info@open-works.net
  12
  13    This program is free software; you can redistribute it and/or
  14    modify it under the terms of the GNU General Public License as
  15    published by the Free Software Foundation; either version 2 of the
  16    License, or (at your option) any later version.
  17
  18    This program is distributed in the hope that it will be useful, but
  19    WITHOUT ANY WARRANTY; without even the implied warranty of
  20    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  21    General Public License for more details.
  22
  23    You should have received a copy of the GNU General Public License
  24    along with this program; if not, write to the Free Software
  25    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  26    02110-1301, USA.
  27
  28    The GNU General Public License is contained in the file COPYING.
  29
  30    Neither the names of the U.S. Department of Energy nor the
  31    University of California nor the names of its contributors may be
  32    used to endorse or promote products derived from this software
  33    without prior written permission.
  34 */
  35
  36 /* Only to be used within the guest-x86 directory. */
  37
  38 #ifndef __VEX_GUEST_X86_DEFS_H
  39 #define __VEX_GUEST_X86_DEFS_H
  40
  41 #include "libvex_basictypes.h"
  42 #include "libvex_guest_x86.h"           // VexGuestX86State
  43 #include "libvex_emnote.h"              // VexEmNote
  44 #include "guest_generic_bb_to_IR.h"     // DisResult
  45
  46 /*---------------------------------------------------------*/
  47 /*--- x86 to IR conversion                              ---*/
  48 /*---------------------------------------------------------*/
  49
  50 /* Convert one x86 insn to IR.  See the type DisOneInstrFn in
  51    guest_generic_bb_to_IR.h. */
  52 extern
  53 DisResult disInstr_X86 ( IRSB*        irbb,
  54                          Bool         (*resteerOkFn) ( void*, Addr ),
  55                          Bool         resteerCisOk,
  56                          void*        callback_opaque,
  57                          const UChar* guest_code,
  58                          Long         delta,
  59                          Addr         guest_IP,
  60                          VexArch      guest_arch,
  61                          const VexArchInfo* archinfo,
  62                          const VexAbiInfo*  abiinfo,
  63                          VexEndness   host_endness,
  64                          Bool         sigill_diag );
  65
  66 /* Used by the optimiser to specialise calls to helpers. */
  67 extern
  68 IRExpr* guest_x86_spechelper ( const HChar* function_name,
  69                                IRExpr** args,
  70                                IRStmt** precedingStmts,
  71                                Int      n_precedingStmts );
  72
  73 /* Describes to the optimiser which part of the guest state require
  74    precise memory exceptions.  This is logically part of the guest
  75    state description. */
  76 extern
  77 Bool guest_x86_state_requires_precise_mem_exns ( Int, Int,
  78                                                  VexRegisterUpdates );
  79
  80 extern
  81 VexGuestLayout x86guest_layout;
  82
  83
  84 /*---------------------------------------------------------*/
  85 /*--- x86 guest helpers                                 ---*/
  86 /*---------------------------------------------------------*/
  87
  88 /* --- CLEAN HELPERS --- */
  89
  90 extern UInt  x86g_calculate_eflags_all (
  91                 UInt cc_op, UInt cc_dep1, UInt cc_dep2, UInt cc_ndep
  92              );
  93
  94 VEX_REGPARM(3)
  95 extern UInt  x86g_calculate_eflags_c (
  96                 UInt cc_op, UInt cc_dep1, UInt cc_dep2, UInt cc_ndep
  97              );
  98
  99 extern UInt  x86g_calculate_condition (
 100                 UInt/*X86Condcode*/ cond,
 101                 UInt cc_op,
 102                 UInt cc_dep1, UInt cc_dep2, UInt cc_ndep
 103              );
 104
 105 extern UInt  x86g_calculate_FXAM ( UInt tag, ULong dbl );
 106
 107 extern ULong x86g_calculate_RCR (
 108                 UInt arg, UInt rot_amt, UInt eflags_in, UInt sz
 109              );
 110 extern ULong x86g_calculate_RCL (
 111                 UInt arg, UInt rot_amt, UInt eflags_in, UInt sz
 112              );
 113
 114 extern UInt x86g_calculate_daa_das_aaa_aas ( UInt AX_and_flags, UInt opcode );
 115
 116 extern UInt x86g_calculate_aad_aam ( UInt AX_and_flags, UInt opcode );
 117
 118 extern ULong x86g_check_fldcw ( UInt fpucw );
 119
 120 extern UInt  x86g_create_fpucw ( UInt fpround );
 121
 122 extern ULong x86g_check_ldmxcsr ( UInt mxcsr );
 123
 124 extern UInt  x86g_create_mxcsr ( UInt sseround );
 125
 126
 127 /* Translate a guest virtual_addr into a guest linear address by
 128    consulting the supplied LDT/GDT structures.  Their representation
 129    must be as specified in pub/libvex_guest_x86.h.  To indicate a
 130    translation failure, 1<<32 is returned.  On success, the lower 32
 131    bits of the returned result indicate the linear address.
 132 */
 133 extern
 134 ULong x86g_use_seg_selector ( HWord ldt, HWord gdt,
 135                               UInt seg_selector, UInt virtual_addr );
 136
 137 extern ULong x86g_calculate_mmx_pmaddwd  ( ULong, ULong );
 138 extern ULong x86g_calculate_mmx_psadbw   ( ULong, ULong );
 139
 140
 141 /* --- DIRTY HELPERS --- */
 142
 143 extern ULong x86g_dirtyhelper_loadF80le  ( Addr );
 144
 145 extern void  x86g_dirtyhelper_storeF80le ( Addr, ULong );
 146
 147 extern void  x86g_dirtyhelper_CPUID_sse0 ( VexGuestX86State* );
 148 extern void  x86g_dirtyhelper_CPUID_mmxext ( VexGuestX86State* );
 149 extern void  x86g_dirtyhelper_CPUID_sse1 ( VexGuestX86State* );
 150 extern void  x86g_dirtyhelper_CPUID_sse2 ( VexGuestX86State* );
 151 extern void  x86g_dirtyhelper_CPUID_sse3 ( VexGuestX86State* );
 152
 153 extern void  x86g_dirtyhelper_FINIT ( VexGuestX86State* );
 154
 155 extern void  x86g_dirtyhelper_FXSAVE ( VexGuestX86State*, HWord );
 156 extern void  x86g_dirtyhelper_FSAVE  ( VexGuestX86State*, HWord );
 157 extern void  x86g_dirtyhelper_FSTENV ( VexGuestX86State*, HWord );
 158
 159 extern ULong x86g_dirtyhelper_RDTSC ( void );
 160
 161 extern UInt x86g_dirtyhelper_IN  ( UInt portno, UInt sz/*1,2 or 4*/ );
 162 extern void x86g_dirtyhelper_OUT ( UInt portno, UInt data,
 163                                    UInt sz/*1,2 or 4*/ );
 164
 165 extern void x86g_dirtyhelper_SxDT ( void* address,
 166                                     UInt op /* 0 or 1 */ );
 167
 168 extern VexEmNote
 169             x86g_dirtyhelper_FXRSTOR ( VexGuestX86State*, HWord );
 170
 171 extern VexEmNote
 172             x86g_dirtyhelper_FRSTOR ( VexGuestX86State*, HWord );
 173
 174 extern VexEmNote
 175             x86g_dirtyhelper_FLDENV ( VexGuestX86State*, HWord );
 176
 177
 178 /*---------------------------------------------------------*/
 179 /*--- Condition code stuff                              ---*/
 180 /*---------------------------------------------------------*/
 181
 182 /* eflags masks */
 183 #define X86G_CC_SHIFT_O   11
 184 #define X86G_CC_SHIFT_S   7
 185 #define X86G_CC_SHIFT_Z   6
 186 #define X86G_CC_SHIFT_A   4
 187 #define X86G_CC_SHIFT_C   0
 188 #define X86G_CC_SHIFT_P   2
 189
 190 #define X86G_CC_MASK_O    (1 << X86G_CC_SHIFT_O)
 191 #define X86G_CC_MASK_S    (1 << X86G_CC_SHIFT_S)
 192 #define X86G_CC_MASK_Z    (1 << X86G_CC_SHIFT_Z)
 193 #define X86G_CC_MASK_A    (1 << X86G_CC_SHIFT_A)
 194 #define X86G_CC_MASK_C    (1 << X86G_CC_SHIFT_C)
 195 #define X86G_CC_MASK_P    (1 << X86G_CC_SHIFT_P)
 196
 197 /* additional eflags masks */
 198 #define X86G_CC_SHIFT_ID  21
 199 #define X86G_CC_SHIFT_AC  18
 200 #define X86G_CC_SHIFT_D   10
 201
 202 #define X86G_CC_MASK_ID   (1 << X86G_CC_SHIFT_ID)
 203 #define X86G_CC_MASK_AC   (1 << X86G_CC_SHIFT_AC)
 204 #define X86G_CC_MASK_D    (1 << X86G_CC_SHIFT_D)
 205
 206 /* FPU flag masks */
 207 #define X86G_FC_SHIFT_C3   14
 208 #define X86G_FC_SHIFT_C2   10
 209 #define X86G_FC_SHIFT_C1   9
 210 #define X86G_FC_SHIFT_C0   8
 211
 212 #define X86G_FC_MASK_C3    (1 << X86G_FC_SHIFT_C3)
 213 #define X86G_FC_MASK_C2    (1 << X86G_FC_SHIFT_C2)
 214 #define X86G_FC_MASK_C1    (1 << X86G_FC_SHIFT_C1)
 215 #define X86G_FC_MASK_C0    (1 << X86G_FC_SHIFT_C0)
 216
 217
 218 /* %EFLAGS thunk descriptors.  A four-word thunk is used to record
 219    details of the most recent flag-setting operation, so the flags can
 220    be computed later if needed.  It is possible to do this a little
 221    more efficiently using a 3-word thunk, but that makes it impossible
 222    to describe the flag data dependencies sufficiently accurately for
 223    Memcheck.  Hence 4 words are used, with minimal loss of efficiency.
 224
 225    The four words are:
 226
 227       CC_OP, which describes the operation.
 228
 229       CC_DEP1 and CC_DEP2.  These are arguments to the operation.
 230          We want Memcheck to believe that the resulting flags are
 231          data-dependent on both CC_DEP1 and CC_DEP2, hence the
 232          name DEP.
 233
 234       CC_NDEP.  This is a 3rd argument to the operation which is
 235          sometimes needed.  We arrange things so that Memcheck does
 236          not believe the resulting flags are data-dependent on CC_NDEP
 237          ("not dependent").
 238
 239    To make Memcheck believe that (the definedness of) the encoded
 240    flags depends only on (the definedness of) CC_DEP1 and CC_DEP2
 241    requires two things:
 242
 243    (1) In the guest state layout info (x86guest_layout), CC_OP and
 244        CC_NDEP are marked as always defined.
 245
 246    (2) When passing the thunk components to an evaluation function
 247        (calculate_condition, calculate_eflags, calculate_eflags_c) the
 248        IRCallee's mcx_mask must be set so as to exclude from
 249        consideration all passed args except CC_DEP1 and CC_DEP2.
 250
 251    Strictly speaking only (2) is necessary for correctness.  However,
 252    (1) helps efficiency in that since (2) means we never ask about the
 253    definedness of CC_OP or CC_NDEP, we may as well not even bother to
 254    track their definedness.
 255
 256    When building the thunk, it is always necessary to write words into
 257    CC_DEP1 and CC_DEP2, even if those args are not used given the
 258    CC_OP field (eg, CC_DEP2 is not used if CC_OP is CC_LOGIC1/2/4).
 259    This is important because otherwise Memcheck could give false
 260    positives as it does not understand the relationship between the
 261    CC_OP field and CC_DEP1 and CC_DEP2, and so believes that the
 262    definedness of the stored flags always depends on both CC_DEP1 and
 263    CC_DEP2.
 264
 265    However, it is only necessary to set CC_NDEP when the CC_OP value
 266    requires it, because Memcheck ignores CC_NDEP, and the evaluation
 267    functions do understand the CC_OP fields and will only examine
 268    CC_NDEP for suitable values of CC_OP.
 269
 270    A summary of the field usages is:
 271
 272    Operation          DEP1               DEP2               NDEP
 273    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 274
 275    add/sub/mul        first arg          second arg         unused
 276
 277    adc/sbb            first arg          (second arg)
 278                                          XOR old_carry      old_carry
 279
 280    and/or/xor         result             zero               unused
 281
 282    inc/dec            result             zero               old_carry
 283
 284    shl/shr/sar        result             subshifted-        unused
 285                                          result
 286
 287    rol/ror            result             zero               old_flags
 288
 289    copy               old_flags          zero               unused.
 290
 291
 292    Therefore Memcheck will believe the following:
 293
 294    * add/sub/mul -- definedness of result flags depends on definedness
 295      of both args.
 296
 297    * adc/sbb -- definedness of result flags depends on definedness of
 298      both args and definedness of the old C flag.  Because only two
 299      DEP fields are available, the old C flag is XOR'd into the second
 300      arg so that Memcheck sees the data dependency on it.  That means
 301      the NDEP field must contain a second copy of the old C flag
 302      so that the evaluation functions can correctly recover the second
 303      arg.
 304
 305    * and/or/xor are straightforward -- definedness of result flags
 306      depends on definedness of result value.
 307
 308    * inc/dec -- definedness of result flags depends only on
 309      definedness of result.  This isn't really true -- it also depends
 310      on the old C flag.  However, we don't want Memcheck to see that,
 311      and so the old C flag must be passed in NDEP and not in DEP2.
 312      It's inconceivable that a compiler would generate code that puts
 313      the C flag in an undefined state, then does an inc/dec, which
 314      leaves C unchanged, and then makes a conditional jump/move based
 315      on C.  So our fiction seems a good approximation.
 316
 317    * shl/shr/sar -- straightforward, again, definedness of result
 318      flags depends on definedness of result value.  The subshifted
 319      value (value shifted one less) is also needed, but its
 320      definedness is the same as the definedness of the shifted value.
 321
 322    * rol/ror -- these only set O and C, and leave A Z C P alone.
 323      However it seems prudent (as per inc/dec) to say the definedness
 324      of all resulting flags depends on the definedness of the result,
 325      hence the old flags must go in as NDEP and not DEP2.
 326
 327    * rcl/rcr are too difficult to do in-line, and so are done by a
 328      helper function.  They are not part of this scheme.  The helper
 329      function takes the value to be rotated, the rotate amount and the
 330      old flags, and returns the new flags and the rotated value.
 331      Since the helper's mcx_mask does not have any set bits, Memcheck
 332      will lazily propagate undefinedness from any of the 3 args into
 333      both results (flags and actual value).
 334 */
 335 enum {
 336     X86G_CC_OP_COPY=0,  /* DEP1 = current flags, DEP2 = 0, NDEP = unused */
 337                         /* just copy DEP1 to output */
 338
 339     X86G_CC_OP_ADDB,    /* 1 */
 340     X86G_CC_OP_ADDW,    /* 2 DEP1 = argL, DEP2 = argR, NDEP = unused */
 341     X86G_CC_OP_ADDL,    /* 3 */
 342
 343     X86G_CC_OP_SUBB,    /* 4 */
 344     X86G_CC_OP_SUBW,    /* 5 DEP1 = argL, DEP2 = argR, NDEP = unused */
 345     X86G_CC_OP_SUBL,    /* 6 */
 346
 347     X86G_CC_OP_ADCB,    /* 7 */
 348     X86G_CC_OP_ADCW,    /* 8 DEP1 = argL, DEP2 = argR ^ oldCarry, NDEP = oldCarry */
 349     X86G_CC_OP_ADCL,    /* 9 */
 350
 351     X86G_CC_OP_SBBB,    /* 10 */
 352     X86G_CC_OP_SBBW,    /* 11 DEP1 = argL, DEP2 = argR ^ oldCarry, NDEP = oldCarry */
 353     X86G_CC_OP_SBBL,    /* 12 */
 354
 355     X86G_CC_OP_LOGICB,  /* 13 */
 356     X86G_CC_OP_LOGICW,  /* 14 DEP1 = result, DEP2 = 0, NDEP = unused */
 357     X86G_CC_OP_LOGICL,  /* 15 */
 358
 359     X86G_CC_OP_INCB,    /* 16 */
 360     X86G_CC_OP_INCW,    /* 17 DEP1 = result, DEP2 = 0, NDEP = oldCarry (0 or 1) */
 361     X86G_CC_OP_INCL,    /* 18 */
 362
 363     X86G_CC_OP_DECB,    /* 19 */
 364     X86G_CC_OP_DECW,    /* 20 DEP1 = result, DEP2 = 0, NDEP = oldCarry (0 or 1) */
 365     X86G_CC_OP_DECL,    /* 21 */
 366
 367     X86G_CC_OP_SHLB,    /* 22 DEP1 = res, DEP2 = res', NDEP = unused */
 368     X86G_CC_OP_SHLW,    /* 23 where res' is like res but shifted one bit less */
 369     X86G_CC_OP_SHLL,    /* 24 */
 370
 371     X86G_CC_OP_SHRB,    /* 25 DEP1 = res, DEP2 = res', NDEP = unused */
 372     X86G_CC_OP_SHRW,    /* 26 where res' is like res but shifted one bit less */
 373     X86G_CC_OP_SHRL,    /* 27 */
 374
 375     X86G_CC_OP_ROLB,    /* 28 */
 376     X86G_CC_OP_ROLW,    /* 29 DEP1 = res, DEP2 = 0, NDEP = old flags */
 377     X86G_CC_OP_ROLL,    /* 30 */
 378
 379     X86G_CC_OP_RORB,    /* 31 */
 380     X86G_CC_OP_RORW,    /* 32 DEP1 = res, DEP2 = 0, NDEP = old flags */
 381     X86G_CC_OP_RORL,    /* 33 */
 382
 383     X86G_CC_OP_UMULB,   /* 34 */
 384     X86G_CC_OP_UMULW,   /* 35 DEP1 = argL, DEP2 = argR, NDEP = unused */
 385     X86G_CC_OP_UMULL,   /* 36 */
 386
 387     X86G_CC_OP_SMULB,   /* 37 */
 388     X86G_CC_OP_SMULW,   /* 38 DEP1 = argL, DEP2 = argR, NDEP = unused */
 389     X86G_CC_OP_SMULL,   /* 39 */
 390
 391     X86G_CC_OP_NUMBER
 392 };
 393
 394 typedef
 395    enum {
 396       X86CondO      = 0,  /* overflow           */
 397       X86CondNO     = 1,  /* no overflow        */
 398
 399       X86CondB      = 2,  /* below              */
 400       X86CondNB     = 3,  /* not below          */
 401
 402       X86CondZ      = 4,  /* zero               */
 403       X86CondNZ     = 5,  /* not zero           */
 404
 405       X86CondBE     = 6,  /* below or equal     */
 406       X86CondNBE    = 7,  /* not below or equal */
 407
 408       X86CondS      = 8,  /* negative           */
 409       X86CondNS     = 9,  /* not negative       */
 410
 411       X86CondP      = 10, /* parity even        */
 412       X86CondNP     = 11, /* not parity even    */
 413
 414       X86CondL      = 12, /* jump less          */
 415       X86CondNL     = 13, /* not less           */
 416
 417       X86CondLE     = 14, /* less or equal      */
 418       X86CondNLE    = 15, /* not less or equal  */
 419
 420       X86CondAlways = 16  /* HACK */
 421    }
 422    X86Condcode;
 423
 424 #endif /* ndef __VEX_GUEST_X86_DEFS_H */
 425
 426 /*---------------------------------------------------------------*/
 427 /*--- end                                    guest_x86_defs.h ---*/
 428 /*---------------------------------------------------------------*/