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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) 2004-2013 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    bb_to_IR.h. */
52 extern
53 DisResult disInstr_X86 ( IRSB*        irbb,
54                          Bool         (*resteerOkFn) ( void*, Addr64 ),
55                          Bool         resteerCisOk,
56                          void*        callback_opaque,
57                          UChar*       guest_code,
58                          Long         delta,
59                          Addr64       guest_IP,
60                          VexArch      guest_arch,
61                          VexArchInfo* archinfo,
62                          VexAbiInfo*  abiinfo,
63                          Bool         host_bigendian,
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 
79 extern
80 VexGuestLayout x86guest_layout;
81 
82 
83 /*---------------------------------------------------------*/
84 /*--- x86 guest helpers                                 ---*/
85 /*---------------------------------------------------------*/
86 
87 /* --- CLEAN HELPERS --- */
88 
89 extern UInt  x86g_calculate_eflags_all (
90                 UInt cc_op, UInt cc_dep1, UInt cc_dep2, UInt cc_ndep
91              );
92 
93 VEX_REGPARM(3)
94 extern UInt  x86g_calculate_eflags_c (
95                 UInt cc_op, UInt cc_dep1, UInt cc_dep2, UInt cc_ndep
96              );
97 
98 extern UInt  x86g_calculate_condition (
99                 UInt/*X86Condcode*/ cond,
100                 UInt cc_op,
101                 UInt cc_dep1, UInt cc_dep2, UInt cc_ndep
102              );
103 
104 extern UInt  x86g_calculate_FXAM ( UInt tag, ULong dbl );
105 
106 extern ULong x86g_calculate_RCR (
107                 UInt arg, UInt rot_amt, UInt eflags_in, UInt sz
108              );
109 extern ULong x86g_calculate_RCL (
110                 UInt arg, UInt rot_amt, UInt eflags_in, UInt sz
111              );
112 
113 extern UInt x86g_calculate_daa_das_aaa_aas ( UInt AX_and_flags, UInt opcode );
114 
115 extern UInt x86g_calculate_aad_aam ( UInt AX_and_flags, UInt opcode );
116 
117 extern ULong x86g_check_fldcw ( UInt fpucw );
118 
119 extern UInt  x86g_create_fpucw ( UInt fpround );
120 
121 extern ULong x86g_check_ldmxcsr ( UInt mxcsr );
122 
123 extern UInt  x86g_create_mxcsr ( UInt sseround );
124 
125 
126 /* Translate a guest virtual_addr into a guest linear address by
127    consulting the supplied LDT/GDT structures.  Their representation
128    must be as specified in pub/libvex_guest_x86.h.  To indicate a
129    translation failure, 1<<32 is returned.  On success, the lower 32
130    bits of the returned result indicate the linear address.
131 */
132 extern
133 ULong x86g_use_seg_selector ( HWord ldt, HWord gdt,
134                               UInt seg_selector, UInt virtual_addr );
135 
136 extern ULong x86g_calculate_mmx_pmaddwd  ( ULong, ULong );
137 extern ULong x86g_calculate_mmx_psadbw   ( ULong, ULong );
138 
139 
140 /* --- DIRTY HELPERS --- */
141 
142 extern ULong x86g_dirtyhelper_loadF80le  ( UInt );
143 
144 extern void  x86g_dirtyhelper_storeF80le ( UInt, ULong );
145 
146 extern void  x86g_dirtyhelper_CPUID_sse0 ( VexGuestX86State* );
147 extern void  x86g_dirtyhelper_CPUID_mmxext ( VexGuestX86State* );
148 extern void  x86g_dirtyhelper_CPUID_sse1 ( VexGuestX86State* );
149 extern void  x86g_dirtyhelper_CPUID_sse2 ( VexGuestX86State* );
150 
151 extern void  x86g_dirtyhelper_FINIT ( VexGuestX86State* );
152 
153 extern void  x86g_dirtyhelper_FXSAVE ( VexGuestX86State*, HWord );
154 extern void  x86g_dirtyhelper_FSAVE  ( VexGuestX86State*, HWord );
155 extern void  x86g_dirtyhelper_FSTENV ( VexGuestX86State*, HWord );
156 
157 extern ULong x86g_dirtyhelper_RDTSC ( void );
158 
159 extern UInt x86g_dirtyhelper_IN  ( UInt portno, UInt sz/*1,2 or 4*/ );
160 extern void x86g_dirtyhelper_OUT ( UInt portno, UInt data,
161                                    UInt sz/*1,2 or 4*/ );
162 
163 extern void x86g_dirtyhelper_SxDT ( void* address,
164                                     UInt op /* 0 or 1 */ );
165 
166 extern VexEmNote
167             x86g_dirtyhelper_FXRSTOR ( VexGuestX86State*, HWord );
168 
169 extern VexEmNote
170             x86g_dirtyhelper_FRSTOR ( VexGuestX86State*, HWord );
171 
172 extern VexEmNote
173             x86g_dirtyhelper_FLDENV ( VexGuestX86State*, HWord );
174 
175 
176 /*---------------------------------------------------------*/
177 /*--- Condition code stuff                              ---*/
178 /*---------------------------------------------------------*/
179 
180 /* eflags masks */
181 #define X86G_CC_SHIFT_O   11
182 #define X86G_CC_SHIFT_S   7
183 #define X86G_CC_SHIFT_Z   6
184 #define X86G_CC_SHIFT_A   4
185 #define X86G_CC_SHIFT_C   0
186 #define X86G_CC_SHIFT_P   2
187 
188 #define X86G_CC_MASK_O    (1 << X86G_CC_SHIFT_O)
189 #define X86G_CC_MASK_S    (1 << X86G_CC_SHIFT_S)
190 #define X86G_CC_MASK_Z    (1 << X86G_CC_SHIFT_Z)
191 #define X86G_CC_MASK_A    (1 << X86G_CC_SHIFT_A)
192 #define X86G_CC_MASK_C    (1 << X86G_CC_SHIFT_C)
193 #define X86G_CC_MASK_P    (1 << X86G_CC_SHIFT_P)
194 
195 /* FPU flag masks */
196 #define X86G_FC_SHIFT_C3   14
197 #define X86G_FC_SHIFT_C2   10
198 #define X86G_FC_SHIFT_C1   9
199 #define X86G_FC_SHIFT_C0   8
200 
201 #define X86G_FC_MASK_C3    (1 << X86G_FC_SHIFT_C3)
202 #define X86G_FC_MASK_C2    (1 << X86G_FC_SHIFT_C2)
203 #define X86G_FC_MASK_C1    (1 << X86G_FC_SHIFT_C1)
204 #define X86G_FC_MASK_C0    (1 << X86G_FC_SHIFT_C0)
205 
206 
207 /* %EFLAGS thunk descriptors.  A four-word thunk is used to record
208    details of the most recent flag-setting operation, so the flags can
209    be computed later if needed.  It is possible to do this a little
210    more efficiently using a 3-word thunk, but that makes it impossible
211    to describe the flag data dependencies sufficiently accurately for
212    Memcheck.  Hence 4 words are used, with minimal loss of efficiency.
213 
214    The four words are:
215 
216       CC_OP, which describes the operation.
217 
218       CC_DEP1 and CC_DEP2.  These are arguments to the operation.
219          We want Memcheck to believe that the resulting flags are
220          data-dependent on both CC_DEP1 and CC_DEP2, hence the
221          name DEP.
222 
223       CC_NDEP.  This is a 3rd argument to the operation which is
224          sometimes needed.  We arrange things so that Memcheck does
225          not believe the resulting flags are data-dependent on CC_NDEP
226          ("not dependent").
227 
228    To make Memcheck believe that (the definedness of) the encoded
229    flags depends only on (the definedness of) CC_DEP1 and CC_DEP2
230    requires two things:
231 
232    (1) In the guest state layout info (x86guest_layout), CC_OP and
233        CC_NDEP are marked as always defined.
234 
235    (2) When passing the thunk components to an evaluation function
236        (calculate_condition, calculate_eflags, calculate_eflags_c) the
237        IRCallee's mcx_mask must be set so as to exclude from
238        consideration all passed args except CC_DEP1 and CC_DEP2.
239 
240    Strictly speaking only (2) is necessary for correctness.  However,
241    (1) helps efficiency in that since (2) means we never ask about the
242    definedness of CC_OP or CC_NDEP, we may as well not even bother to
243    track their definedness.
244 
245    When building the thunk, it is always necessary to write words into
246    CC_DEP1 and CC_DEP2, even if those args are not used given the
247    CC_OP field (eg, CC_DEP2 is not used if CC_OP is CC_LOGIC1/2/4).
248    This is important because otherwise Memcheck could give false
249    positives as it does not understand the relationship between the
250    CC_OP field and CC_DEP1 and CC_DEP2, and so believes that the
251    definedness of the stored flags always depends on both CC_DEP1 and
252    CC_DEP2.
253 
254    However, it is only necessary to set CC_NDEP when the CC_OP value
255    requires it, because Memcheck ignores CC_NDEP, and the evaluation
256    functions do understand the CC_OP fields and will only examine
257    CC_NDEP for suitable values of CC_OP.
258 
259    A summary of the field usages is:
260 
261    Operation          DEP1               DEP2               NDEP
262    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
263 
264    add/sub/mul        first arg          second arg         unused
265 
266    adc/sbb            first arg          (second arg)
267                                          XOR old_carry      old_carry
268 
269    and/or/xor         result             zero               unused
270 
271    inc/dec            result             zero               old_carry
272 
273    shl/shr/sar        result             subshifted-        unused
274                                          result
275 
276    rol/ror            result             zero               old_flags
277 
278    copy               old_flags          zero               unused.
279 
280 
281    Therefore Memcheck will believe the following:
282 
283    * add/sub/mul -- definedness of result flags depends on definedness
284      of both args.
285 
286    * adc/sbb -- definedness of result flags depends on definedness of
287      both args and definedness of the old C flag.  Because only two
288      DEP fields are available, the old C flag is XOR'd into the second
289      arg so that Memcheck sees the data dependency on it.  That means
290      the NDEP field must contain a second copy of the old C flag
291      so that the evaluation functions can correctly recover the second
292      arg.
293 
294    * and/or/xor are straightforward -- definedness of result flags
295      depends on definedness of result value.
296 
297    * inc/dec -- definedness of result flags depends only on
298      definedness of result.  This isn't really true -- it also depends
299      on the old C flag.  However, we don't want Memcheck to see that,
300      and so the old C flag must be passed in NDEP and not in DEP2.
301      It's inconceivable that a compiler would generate code that puts
302      the C flag in an undefined state, then does an inc/dec, which
303      leaves C unchanged, and then makes a conditional jump/move based
304      on C.  So our fiction seems a good approximation.
305 
306    * shl/shr/sar -- straightforward, again, definedness of result
307      flags depends on definedness of result value.  The subshifted
308      value (value shifted one less) is also needed, but its
309      definedness is the same as the definedness of the shifted value.
310 
311    * rol/ror -- these only set O and C, and leave A Z C P alone.
312      However it seems prudent (as per inc/dec) to say the definedness
313      of all resulting flags depends on the definedness of the result,
314      hence the old flags must go in as NDEP and not DEP2.
315 
316    * rcl/rcr are too difficult to do in-line, and so are done by a
317      helper function.  They are not part of this scheme.  The helper
318      function takes the value to be rotated, the rotate amount and the
319      old flags, and returns the new flags and the rotated value.
320      Since the helper's mcx_mask does not have any set bits, Memcheck
321      will lazily propagate undefinedness from any of the 3 args into
322      both results (flags and actual value).
323 */
324 enum {
325     X86G_CC_OP_COPY=0,  /* DEP1 = current flags, DEP2 = 0, NDEP = unused */
326                         /* just copy DEP1 to output */
327 
328     X86G_CC_OP_ADDB,    /* 1 */
329     X86G_CC_OP_ADDW,    /* 2 DEP1 = argL, DEP2 = argR, NDEP = unused */
330     X86G_CC_OP_ADDL,    /* 3 */
331 
332     X86G_CC_OP_SUBB,    /* 4 */
333     X86G_CC_OP_SUBW,    /* 5 DEP1 = argL, DEP2 = argR, NDEP = unused */
334     X86G_CC_OP_SUBL,    /* 6 */
335 
336     X86G_CC_OP_ADCB,    /* 7 */
337     X86G_CC_OP_ADCW,    /* 8 DEP1 = argL, DEP2 = argR ^ oldCarry, NDEP = oldCarry */
338     X86G_CC_OP_ADCL,    /* 9 */
339 
340     X86G_CC_OP_SBBB,    /* 10 */
341     X86G_CC_OP_SBBW,    /* 11 DEP1 = argL, DEP2 = argR ^ oldCarry, NDEP = oldCarry */
342     X86G_CC_OP_SBBL,    /* 12 */
343 
344     X86G_CC_OP_LOGICB,  /* 13 */
345     X86G_CC_OP_LOGICW,  /* 14 DEP1 = result, DEP2 = 0, NDEP = unused */
346     X86G_CC_OP_LOGICL,  /* 15 */
347 
348     X86G_CC_OP_INCB,    /* 16 */
349     X86G_CC_OP_INCW,    /* 17 DEP1 = result, DEP2 = 0, NDEP = oldCarry (0 or 1) */
350     X86G_CC_OP_INCL,    /* 18 */
351 
352     X86G_CC_OP_DECB,    /* 19 */
353     X86G_CC_OP_DECW,    /* 20 DEP1 = result, DEP2 = 0, NDEP = oldCarry (0 or 1) */
354     X86G_CC_OP_DECL,    /* 21 */
355 
356     X86G_CC_OP_SHLB,    /* 22 DEP1 = res, DEP2 = res', NDEP = unused */
357     X86G_CC_OP_SHLW,    /* 23 where res' is like res but shifted one bit less */
358     X86G_CC_OP_SHLL,    /* 24 */
359 
360     X86G_CC_OP_SHRB,    /* 25 DEP1 = res, DEP2 = res', NDEP = unused */
361     X86G_CC_OP_SHRW,    /* 26 where res' is like res but shifted one bit less */
362     X86G_CC_OP_SHRL,    /* 27 */
363 
364     X86G_CC_OP_ROLB,    /* 28 */
365     X86G_CC_OP_ROLW,    /* 29 DEP1 = res, DEP2 = 0, NDEP = old flags */
366     X86G_CC_OP_ROLL,    /* 30 */
367 
368     X86G_CC_OP_RORB,    /* 31 */
369     X86G_CC_OP_RORW,    /* 32 DEP1 = res, DEP2 = 0, NDEP = old flags */
370     X86G_CC_OP_RORL,    /* 33 */
371 
372     X86G_CC_OP_UMULB,   /* 34 */
373     X86G_CC_OP_UMULW,   /* 35 DEP1 = argL, DEP2 = argR, NDEP = unused */
374     X86G_CC_OP_UMULL,   /* 36 */
375 
376     X86G_CC_OP_SMULB,   /* 37 */
377     X86G_CC_OP_SMULW,   /* 38 DEP1 = argL, DEP2 = argR, NDEP = unused */
378     X86G_CC_OP_SMULL,   /* 39 */
379 
380     X86G_CC_OP_NUMBER
381 };
382 
383 typedef
384    enum {
385       X86CondO      = 0,  /* overflow           */
386       X86CondNO     = 1,  /* no overflow        */
387 
388       X86CondB      = 2,  /* below              */
389       X86CondNB     = 3,  /* not below          */
390 
391       X86CondZ      = 4,  /* zero               */
392       X86CondNZ     = 5,  /* not zero           */
393 
394       X86CondBE     = 6,  /* below or equal     */
395       X86CondNBE    = 7,  /* not below or equal */
396 
397       X86CondS      = 8,  /* negative           */
398       X86CondNS     = 9,  /* not negative       */
399 
400       X86CondP      = 10, /* parity even        */
401       X86CondNP     = 11, /* not parity even    */
402 
403       X86CondL      = 12, /* jump less          */
404       X86CondNL     = 13, /* not less           */
405 
406       X86CondLE     = 14, /* less or equal      */
407       X86CondNLE    = 15, /* not less or equal  */
408 
409       X86CondAlways = 16  /* HACK */
410    }
411    X86Condcode;
412 
413 #endif /* ndef __VEX_GUEST_X86_DEFS_H */
414 
415 /*---------------------------------------------------------------*/
416 /*--- end                                    guest_x86_defs.h ---*/
417 /*---------------------------------------------------------------*/
418