1 
2 /*---------------------------------------------------------------*/
3 /*--- begin                                          libvex.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 #ifndef __LIBVEX_H
37 #define __LIBVEX_H
38 
39 
40 #include "libvex_basictypes.h"
41 #include "libvex_ir.h"
42 
43 
44 /*---------------------------------------------------------------*/
45 /*--- This file defines the top-level interface to LibVEX.    ---*/
46 /*---------------------------------------------------------------*/
47 
48 /*-------------------------------------------------------*/
49 /*--- Architectures, variants, and other arch info    ---*/
50 /*-------------------------------------------------------*/
51 
52 typedef
53    enum {
54       VexArch_INVALID=0x400,
55       VexArchX86,
56       VexArchAMD64,
57       VexArchARM,
58       VexArchARM64,
59       VexArchPPC32,
60       VexArchPPC64,
61       VexArchS390X,
62       VexArchMIPS32,
63       VexArchMIPS64,
64       VexArchTILEGX
65    }
66    VexArch;
67 
68 
69 /* Information about endianness. */
70 typedef
71    enum {
72       VexEndness_INVALID=0x600, /* unknown endianness */
73       VexEndnessLE,             /* little endian */
74       VexEndnessBE              /* big endian */
75    }
76    VexEndness;
77 
78 
79 /* For a given architecture, these specify extra capabilities beyond
80    the minimum supported (baseline) capabilities.  They may be OR'd
81    together, although some combinations don't make sense.  (eg, SSE2
82    but not SSE1).  LibVEX_Translate will check for nonsensical
83    combinations. */
84 
85 /* x86: baseline capability is Pentium-1 (FPU, MMX, but no SSE), with
86    cmpxchg8b. MMXEXT is a special AMD only subset of SSE1 (Integer SSE). */
87 #define VEX_HWCAPS_X86_MMXEXT  (1<<1)  /* A subset of SSE1 on early AMD */
88 #define VEX_HWCAPS_X86_SSE1    (1<<2)  /* SSE1 support (Pentium III) */
89 #define VEX_HWCAPS_X86_SSE2    (1<<3)  /* SSE2 support (Pentium 4) */
90 #define VEX_HWCAPS_X86_SSE3    (1<<4)  /* SSE3 support (>= Prescott) */
91 #define VEX_HWCAPS_X86_LZCNT   (1<<5)  /* SSE4a LZCNT insn */
92 
93 /* amd64: baseline capability is SSE2, with cmpxchg8b but not
94    cmpxchg16b. */
95 #define VEX_HWCAPS_AMD64_SSE3   (1<<5)  /* SSE3 support */
96 #define VEX_HWCAPS_AMD64_CX16   (1<<6)  /* cmpxchg16b support */
97 #define VEX_HWCAPS_AMD64_LZCNT  (1<<7)  /* SSE4a LZCNT insn */
98 #define VEX_HWCAPS_AMD64_AVX    (1<<8)  /* AVX instructions */
99 #define VEX_HWCAPS_AMD64_RDTSCP (1<<9)  /* RDTSCP instruction */
100 #define VEX_HWCAPS_AMD64_BMI    (1<<10) /* BMI1 instructions */
101 #define VEX_HWCAPS_AMD64_AVX2   (1<<11) /* AVX2 instructions */
102 
103 /* ppc32: baseline capability is integer only */
104 #define VEX_HWCAPS_PPC32_F     (1<<8)  /* basic (non-optional) FP */
105 #define VEX_HWCAPS_PPC32_V     (1<<9)  /* Altivec (VMX) */
106 #define VEX_HWCAPS_PPC32_FX    (1<<10) /* FP extns (fsqrt, fsqrts) */
107 #define VEX_HWCAPS_PPC32_GX    (1<<11) /* Graphics extns
108                                           (fres,frsqrte,fsel,stfiwx) */
109 #define VEX_HWCAPS_PPC32_VX    (1<<12) /* Vector-scalar floating-point (VSX); implies ISA 2.06 or higher  */
110 #define VEX_HWCAPS_PPC32_DFP   (1<<17) /* Decimal Floating Point (DFP) -- e.g., dadd */
111 #define VEX_HWCAPS_PPC32_ISA2_07   (1<<19) /* ISA 2.07 -- e.g., mtvsrd */
112 
113 /* ppc64: baseline capability is integer and basic FP insns */
114 #define VEX_HWCAPS_PPC64_V     (1<<13) /* Altivec (VMX) */
115 #define VEX_HWCAPS_PPC64_FX    (1<<14) /* FP extns (fsqrt, fsqrts) */
116 #define VEX_HWCAPS_PPC64_GX    (1<<15) /* Graphics extns
117                                           (fres,frsqrte,fsel,stfiwx) */
118 #define VEX_HWCAPS_PPC64_VX    (1<<16) /* Vector-scalar floating-point (VSX); implies ISA 2.06 or higher  */
119 #define VEX_HWCAPS_PPC64_DFP   (1<<18) /* Decimal Floating Point (DFP) -- e.g., dadd */
120 #define VEX_HWCAPS_PPC64_ISA2_07   (1<<20) /* ISA 2.07 -- e.g., mtvsrd */
121 
122 /* s390x: Hardware capability encoding
123 
124    Bits [26:31] encode the machine model (see VEX_S390X_MODEL... below)
125    Bits [0:20]  encode specific hardware capabilities
126                 (see VEX_HWAPS_S390X_... below)
127 */
128 
129 /* Model numbers must be assigned in chronological order.
130    They are used as array index. */
131 #define VEX_S390X_MODEL_Z900     0
132 #define VEX_S390X_MODEL_Z800     1
133 #define VEX_S390X_MODEL_Z990     2
134 #define VEX_S390X_MODEL_Z890     3
135 #define VEX_S390X_MODEL_Z9_EC    4
136 #define VEX_S390X_MODEL_Z9_BC    5
137 #define VEX_S390X_MODEL_Z10_EC   6
138 #define VEX_S390X_MODEL_Z10_BC   7
139 #define VEX_S390X_MODEL_Z196     8
140 #define VEX_S390X_MODEL_Z114     9
141 #define VEX_S390X_MODEL_ZEC12    10
142 #define VEX_S390X_MODEL_ZBC12    11
143 #define VEX_S390X_MODEL_Z13      12
144 #define VEX_S390X_MODEL_UNKNOWN  13     /* always last in list */
145 #define VEX_S390X_MODEL_MASK     0x3F
146 
147 #define VEX_HWCAPS_S390X_LDISP (1<<6)   /* Long-displacement facility */
148 #define VEX_HWCAPS_S390X_EIMM  (1<<7)   /* Extended-immediate facility */
149 #define VEX_HWCAPS_S390X_GIE   (1<<8)   /* General-instruction-extension facility */
150 #define VEX_HWCAPS_S390X_DFP   (1<<9)   /* Decimal floating point facility */
151 #define VEX_HWCAPS_S390X_FGX   (1<<10)  /* FPR-GR transfer facility */
152 #define VEX_HWCAPS_S390X_ETF2  (1<<11)  /* ETF2-enhancement facility */
153 #define VEX_HWCAPS_S390X_STFLE (1<<12)  /* STFLE facility */
154 #define VEX_HWCAPS_S390X_ETF3  (1<<13)  /* ETF3-enhancement facility */
155 #define VEX_HWCAPS_S390X_STCKF (1<<14)  /* STCKF facility */
156 #define VEX_HWCAPS_S390X_FPEXT (1<<15)  /* Floating point extension facility */
157 #define VEX_HWCAPS_S390X_LSC   (1<<16)  /* Conditional load/store facility */
158 #define VEX_HWCAPS_S390X_PFPO  (1<<17)  /* Perform floating point ops facility */
159 
160 /* Special value representing all available s390x hwcaps */
161 #define VEX_HWCAPS_S390X_ALL   (VEX_HWCAPS_S390X_LDISP | \
162                                 VEX_HWCAPS_S390X_EIMM  | \
163                                 VEX_HWCAPS_S390X_GIE   | \
164                                 VEX_HWCAPS_S390X_DFP   | \
165                                 VEX_HWCAPS_S390X_FGX   | \
166                                 VEX_HWCAPS_S390X_STFLE | \
167                                 VEX_HWCAPS_S390X_STCKF | \
168                                 VEX_HWCAPS_S390X_FPEXT | \
169                                 VEX_HWCAPS_S390X_LSC   | \
170                                 VEX_HWCAPS_S390X_ETF3  | \
171                                 VEX_HWCAPS_S390X_ETF2  | \
172                                 VEX_HWCAPS_S390X_PFPO)
173 
174 #define VEX_HWCAPS_S390X(x)  ((x) & ~VEX_S390X_MODEL_MASK)
175 #define VEX_S390X_MODEL(x)   ((x) &  VEX_S390X_MODEL_MASK)
176 
177 /* Tilegx: baseline capability is TILEGX36 */
178 #define VEX_HWCAPS_TILEGX_BASE (1<<16)  /* TILEGX Baseline */
179 
180 /* arm: baseline capability is ARMv4 */
181 /* Bits 5:0 - architecture level (e.g. 5 for v5, 6 for v6 etc) */
182 #define VEX_HWCAPS_ARM_VFP    (1<<6)  /* VFP extension */
183 #define VEX_HWCAPS_ARM_VFP2   (1<<7)  /* VFPv2 */
184 #define VEX_HWCAPS_ARM_VFP3   (1<<8)  /* VFPv3 */
185 /* Bits 15:10 reserved for (possible) future VFP revisions */
186 #define VEX_HWCAPS_ARM_NEON   (1<<16) /* Advanced SIMD also known as NEON */
187 
188 /* Get an ARM architecure level from HWCAPS */
189 #define VEX_ARM_ARCHLEVEL(x) ((x) & 0x3f)
190 
191 /* ARM64: baseline capability is AArch64 v8. */
192 /* (no definitions since no variants so far) */
193 
194 /* MIPS baseline capability */
195 /* Assigned Company values for bits 23:16 of the PRId Register
196    (CP0 register 15, select 0).  As of the MIPS32 and MIPS64 specs from
197    MTI, the PRId register is defined in this (backwards compatible)
198    way:
199 
200   +----------------+----------------+----------------+----------------+
201   | Company Options| Company ID     | Processor ID   | Revision       |
202   +----------------+----------------+----------------+----------------+
203    31            24 23            16 15             8 7
204 
205 */
206 
207 #define VEX_PRID_COMP_MIPS      0x00010000
208 #define VEX_PRID_COMP_BROADCOM  0x00020000
209 #define VEX_PRID_COMP_NETLOGIC  0x000C0000
210 #define VEX_PRID_COMP_CAVIUM    0x000D0000
211 
212 /*
213  * These are the PRID's for when 23:16 == PRID_COMP_MIPS
214  */
215 #define VEX_PRID_IMP_34K        0x9500
216 #define VEX_PRID_IMP_74K        0x9700
217 
218 /* CPU has FPU and 32 dbl. prec. FP registers */
219 #define VEX_PRID_CPU_32FPR      0x00000040
220 
221 /* Get MIPS Company ID from HWCAPS */
222 #define VEX_MIPS_COMP_ID(x) ((x) & 0x00FF0000)
223 /* Get MIPS Processor ID from HWCAPS */
224 #define VEX_MIPS_PROC_ID(x) ((x) & 0x0000FF00)
225 /* Get MIPS Revision from HWCAPS */
226 #define VEX_MIPS_REV(x) ((x) & 0x000000FF)
227 /* Check if the processor supports DSP ASE Rev 2. */
228 #define VEX_MIPS_PROC_DSP2(x) ((VEX_MIPS_COMP_ID(x) == VEX_PRID_COMP_MIPS) && \
229                                (VEX_MIPS_PROC_ID(x) == VEX_PRID_IMP_74K))
230 /* Check if the processor supports DSP ASE Rev 1. */
231 #define VEX_MIPS_PROC_DSP(x)  (VEX_MIPS_PROC_DSP2(x) || \
232                                ((VEX_MIPS_COMP_ID(x) == VEX_PRID_COMP_MIPS) && \
233                                (VEX_MIPS_PROC_ID(x) == VEX_PRID_IMP_34K)))
234 
235 /* These return statically allocated strings. */
236 
237 extern const HChar* LibVEX_ppVexArch    ( VexArch );
238 extern const HChar* LibVEX_ppVexEndness ( VexEndness endness );
239 extern const HChar* LibVEX_ppVexHwCaps  ( VexArch, UInt );
240 
241 
242 /* The various kinds of caches */
243 typedef enum {
244    DATA_CACHE=0x500,
245    INSN_CACHE,
246    UNIFIED_CACHE
247 } VexCacheKind;
248 
249 /* Information about a particular cache */
250 typedef struct {
251    VexCacheKind kind;
252    UInt level;         /* level this cache is at, e.g. 1 for L1 cache */
253    UInt sizeB;         /* size of this cache in bytes */
254    UInt line_sizeB;    /* cache line size in bytes */
255    UInt assoc;         /* set associativity */
256    Bool is_trace_cache;  /* False, except for certain Pentium 4 models */
257 } VexCache;
258 
259 /* Convenience macro to initialise a VexCache */
260 #define VEX_CACHE_INIT(_kind, _level, _size, _line_size, _assoc)         \
261          ({ (VexCache) { .kind = _kind, .level = _level, .sizeB = _size, \
262                .line_sizeB = _line_size, .assoc = _assoc, \
263                .is_trace_cache = False }; })
264 
265 /* Information about the cache system as a whole */
266 typedef struct {
267    UInt num_levels;
268    UInt num_caches;
269    /* Unordered array of caches for this host. NULL if there are
270       no caches. The following can always be assumed:
271       (1) There is at most one cache of a given kind per cache level.
272       (2) If there exists a unified cache at a particular level then
273           no other cache exists at that level.
274       (3) The existence of a cache at level N > 1 implies the existence of
275           at least one cache at level N-1. */
276    VexCache *caches;
277    Bool icaches_maintain_coherence;
278 } VexCacheInfo;
279 
280 
281 /* This struct is a bit of a hack, but is needed to carry misc
282    important bits of info about an arch.  Fields which are meaningless
283    or ignored for the platform in question should be set to zero.
284    Nb: if you add fields to the struct make sure to update function
285    LibVEX_default_VexArchInfo. */
286 
287 typedef
288    struct {
289       /* The following three fields are mandatory. */
290       UInt         hwcaps;
291       VexEndness   endness;
292       VexCacheInfo hwcache_info;
293       /* PPC32/PPC64 only: size of instruction cache line */
294       Int ppc_icache_line_szB;
295       /* PPC32/PPC64 only: sizes zeroed by the dcbz/dcbzl instructions
296          (bug#135264) */
297       UInt ppc_dcbz_szB;
298       UInt ppc_dcbzl_szB; /* 0 means unsupported (SIGILL) */
299       /* ARM64: I- and D- minimum line sizes in log2(bytes), as
300          obtained from ctr_el0.DminLine and .IminLine.  For example, a
301          line size of 64 bytes would be encoded here as 6. */
302       UInt arm64_dMinLine_lg2_szB;
303       UInt arm64_iMinLine_lg2_szB;
304    }
305    VexArchInfo;
306 
307 /* Write default settings info *vai. */
308 extern
309 void LibVEX_default_VexArchInfo ( /*OUT*/VexArchInfo* vai );
310 
311 
312 /* This struct carries guest and host ABI variant information that may
313    be needed.  Fields which are meaningless or ignored for the
314    platform in question should be set to zero.
315 
316    Settings which are believed to be correct are:
317 
318    guest_stack_redzone_size
319       guest is ppc32-linux                ==> 0
320       guest is ppc64-linux                ==> 288
321       guest is amd64-linux                ==> 128
322       guest is other                      ==> inapplicable
323 
324    guest_amd64_assume_fs_is_const
325       guest is amd64-linux                ==> True
326       guest is amd64-darwin               ==> False
327       guest is other                      ==> inapplicable
328 
329    guest_amd64_assume_gs_is_const
330       guest is amd64-darwin               ==> True
331       guest is amd64-linux                ==> True
332       guest is other                      ==> inapplicable
333 
334    guest_ppc_zap_RZ_at_blr
335       guest is ppc64-linux                ==> True
336       guest is ppc32-linux                ==> False
337       guest is other                      ==> inapplicable
338 
339    guest_ppc_zap_RZ_at_bl
340       guest is ppc64-linux                ==> const True
341       guest is ppc32-linux                ==> const False
342       guest is other                      ==> inapplicable
343 
344    host_ppc_calls_use_fndescrs:
345       host is ppc32-linux                 ==> False
346       host is ppc64-linux                 ==> True
347       host is other                       ==> inapplicable
348 */
349 
350 typedef
351    struct {
352       /* PPC and AMD64 GUESTS only: how many bytes below the
353          stack pointer are validly addressible? */
354       Int guest_stack_redzone_size;
355 
356       /* AMD64 GUESTS only: should we translate %fs-prefixed
357          instructions using the assumption that %fs always contains
358          the same value? (typically zero on linux) */
359       Bool guest_amd64_assume_fs_is_const;
360 
361       /* AMD64 GUESTS only: should we translate %gs-prefixed
362          instructions using the assumption that %gs always contains
363          the same value? (typically 0x60 on darwin)? */
364       Bool guest_amd64_assume_gs_is_const;
365 
366       /* PPC GUESTS only: should we zap the stack red zone at a 'blr'
367          (function return) ? */
368       Bool guest_ppc_zap_RZ_at_blr;
369 
370       /* PPC GUESTS only: should we zap the stack red zone at a 'bl'
371          (function call) ?  Is supplied with the guest address of the
372          target of the call since that may be significant.  If NULL,
373          is assumed equivalent to a fn which always returns False. */
374       Bool (*guest_ppc_zap_RZ_at_bl)(Addr);
375 
376       /* PPC32/PPC64 HOSTS only: does '&f' give us a pointer to a
377          function descriptor on the host, or to the function code
378          itself?  True => descriptor, False => code. */
379       Bool host_ppc_calls_use_fndescrs;
380    }
381    VexAbiInfo;
382 
383 /* Write default settings info *vbi. */
384 extern
385 void LibVEX_default_VexAbiInfo ( /*OUT*/VexAbiInfo* vbi );
386 
387 
388 /*-------------------------------------------------------*/
389 /*--- Control of Vex's optimiser (iropt).             ---*/
390 /*-------------------------------------------------------*/
391 
392 
393 /* VexRegisterUpdates specifies when to ensure that the guest state is
394    up to date, in order of increasing accuracy but increasing expense.
395 
396      VexRegUpdSpAtMemAccess: all registers are updated at superblock
397      exits, and SP is also up to date at memory exception points.  The
398      SP is described by the arch specific functions
399      guest_<arch>_state_requires_precise_mem_exns.
400 
401      VexRegUpdUnwindregsAtMemAccess: registers needed to make a stack
402      trace are up to date at memory exception points.  Typically,
403      these are PC/SP/FP.  The minimal registers are described by the
404      arch specific functions guest_<arch>_state_requires_precise_mem_exns.
405      This is what Valgrind sets as the default.
406 
407      VexRegUpdAllregsAtMemAccess: all registers up to date at memory
408      exception points.  This is what normally might be considered as
409      providing "precise exceptions for memory", but does not
410      necessarily provide precise register values at any other kind of
411      exception.
412 
413      VexRegUpdAllregsAtEachInsn: all registers up to date at each
414      instruction.
415 */
416 typedef
417    enum {
418       VexRegUpd_INVALID=0x700,
419       VexRegUpdSpAtMemAccess,
420       VexRegUpdUnwindregsAtMemAccess,
421       VexRegUpdAllregsAtMemAccess,
422       VexRegUpdAllregsAtEachInsn
423    }
424    VexRegisterUpdates;
425 
426 /* Control of Vex's optimiser. */
427 
428 typedef
429    struct {
430       /* Controls verbosity of iropt.  0 = no output. */
431       Int iropt_verbosity;
432       /* Control aggressiveness of iropt.  0 = no opt, 1 = simple
433          opts, 2 (default) = max optimisation. */
434       Int iropt_level;
435       /* Controls when registers are updated in guest state.  Note
436          that this is the default value.  The VEX client can override
437          this on a per-IRSB basis if it wants.  bb_to_IR() will query
438          the client to ask if it wants a different setting for the
439          block under construction, and that new setting is transported
440          back to LibVEX_Translate, which feeds it to iropt via the
441          various do_iropt_BB calls. */
442       VexRegisterUpdates iropt_register_updates_default;
443       /* How aggressive should iropt be in unrolling loops?  Higher
444          numbers make it more enthusiastic about loop unrolling.
445          Default=120.  A setting of zero disables unrolling.  */
446       Int iropt_unroll_thresh;
447       /* What's the maximum basic block length the front end(s) allow?
448          BBs longer than this are split up.  Default=50 (guest
449          insns). */
450       Int guest_max_insns;
451       /* How aggressive should front ends be in following
452          unconditional branches to known destinations?  Default=10,
453          meaning that if a block contains less than 10 guest insns so
454          far, the front end(s) will attempt to chase into its
455          successor. A setting of zero disables chasing.  */
456       Int guest_chase_thresh;
457       /* EXPERIMENTAL: chase across conditional branches?  Not all
458          front ends honour this.  Default: NO. */
459       Bool guest_chase_cond;
460    }
461    VexControl;
462 
463 
464 /* Write the default settings into *vcon. */
465 
466 extern
467 void LibVEX_default_VexControl ( /*OUT*/ VexControl* vcon );
468 
469 
470 /*-------------------------------------------------------*/
471 /*--- Storage management control                      ---*/
472 /*-------------------------------------------------------*/
473 
474 /* Allocate in Vex's temporary allocation area.  Be careful with this.
475    You can only call it inside an instrumentation or optimisation
476    callback that you have previously specified in a call to
477    LibVEX_Translate.  The storage allocated will only stay alive until
478    translation of the current basic block is complete. */
479 extern void* LibVEX_Alloc ( SizeT nbytes );
480 
481 /* Show Vex allocation statistics. */
482 extern void LibVEX_ShowAllocStats ( void );
483 
484 
485 /*-------------------------------------------------------*/
486 /*--- Describing guest state layout                   ---*/
487 /*-------------------------------------------------------*/
488 
489 /* Describe the guest state enough that the instrumentation
490    functions can work. */
491 
492 /* The max number of guest state chunks which we can describe as
493    always defined (for the benefit of Memcheck). */
494 #define VEXGLO_N_ALWAYSDEFD  24
495 
496 typedef
497    struct {
498       /* Total size of the guest state, in bytes.  Must be
499          16-aligned. */
500       Int total_sizeB;
501       /* Whereabouts is the stack pointer? */
502       Int offset_SP;
503       Int sizeof_SP; /* 4 or 8 */
504       /* Whereabouts is the frame pointer? */
505       Int offset_FP;
506       Int sizeof_FP; /* 4 or 8 */
507       /* Whereabouts is the instruction pointer? */
508       Int offset_IP;
509       Int sizeof_IP; /* 4 or 8 */
510       /* Describe parts of the guest state regarded as 'always
511          defined'. */
512       Int n_alwaysDefd;
513       struct {
514          Int offset;
515          Int size;
516       } alwaysDefd[VEXGLO_N_ALWAYSDEFD];
517    }
518    VexGuestLayout;
519 
520 /* A note about guest state layout.
521 
522    LibVEX defines the layout for the guest state, in the file
523    pub/libvex_guest_<arch>.h.  The struct will have an 16-aligned
524    size.  Each translated bb is assumed to be entered with a specified
525    register pointing at such a struct.  Beyond that is two copies of
526    the shadow state area with the same size as the struct.  Beyond
527    that is a spill area that LibVEX may spill into.  It must have size
528    LibVEX_N_SPILL_BYTES, and this must be a 16-aligned number.
529 
530    On entry, the baseblock pointer register must be 16-aligned.
531 
532    There must be no holes in between the primary guest state, its two
533    copies, and the spill area.  In short, all 4 areas must have a
534    16-aligned size and be 16-aligned, and placed back-to-back.
535 */
536 
537 #define LibVEX_N_SPILL_BYTES 4096
538 
539 /* The size of the guest state must be a multiple of this number. */
540 #define LibVEX_GUEST_STATE_ALIGN 16
541 
542 /*-------------------------------------------------------*/
543 /*--- Initialisation of the library                   ---*/
544 /*-------------------------------------------------------*/
545 
546 /* Initialise the library.  You must call this first. */
547 
548 extern void LibVEX_Init (
549 
550    /* failure exit function */
551 #  if __cplusplus == 1 && __GNUC__ && __GNUC__ <= 3
552    /* g++ 3.x doesn't understand attributes on function parameters.
553       See #265762. */
554 #  else
555    __attribute__ ((noreturn))
556 #  endif
557    void (*failure_exit) ( void ),
558 
559    /* logging output function */
560    void (*log_bytes) ( const HChar*, SizeT nbytes ),
561 
562    /* debug paranoia level */
563    Int debuglevel,
564 
565    /* Control ... */
566    const VexControl* vcon
567 );
568 
569 
570 /*-------------------------------------------------------*/
571 /*--- Make a translation                              ---*/
572 /*-------------------------------------------------------*/
573 
574 /* Describes the outcome of a translation attempt. */
575 typedef
576    struct {
577       /* overall status */
578       enum { VexTransOK=0x800,
579              VexTransAccessFail, VexTransOutputFull } status;
580       /* The number of extents that have a self-check (0 to 3) */
581       UInt n_sc_extents;
582       /* Offset in generated code of the profile inc, or -1 if
583          none.  Needed for later patching. */
584       Int offs_profInc;
585       /* Stats only: the number of guest insns included in the
586          translation.  It may be zero (!). */
587       UInt n_guest_instrs;
588    }
589    VexTranslateResult;
590 
591 
592 /* Describes precisely the pieces of guest code that a translation
593    covers.  Now that Vex can chase across BB boundaries, the old
594    scheme of describing a chunk of guest code merely by its start
595    address and length is inadequate.
596 
597    This struct uses 20 bytes on a 32-bit archtecture and 32 bytes on a
598    64-bit architecture.  Space is important as clients will have to store
599    one of these for each translation made.
600 */
601 typedef
602    struct {
603       Addr   base[3];
604       UShort len[3];
605       UShort n_used;
606    }
607    VexGuestExtents;
608 
609 
610 /* A structure to carry arguments for LibVEX_Translate.  There are so
611    many of them, it seems better to have a structure. */
612 typedef
613    struct {
614       /* IN: The instruction sets we are translating from and to.  And
615          guest/host misc info. */
616       VexArch      arch_guest;
617       VexArchInfo  archinfo_guest;
618       VexArch      arch_host;
619       VexArchInfo  archinfo_host;
620       VexAbiInfo   abiinfo_both;
621 
622       /* IN: an opaque value which is passed as the first arg to all
623          callback functions supplied in this struct.  Vex has no idea
624          what's at the other end of this pointer. */
625       void*   callback_opaque;
626 
627       /* IN: the block to translate, and its guest address. */
628       /* where are the actual bytes in the host's address space? */
629       const UChar*  guest_bytes;
630       /* where do the bytes really come from in the guest's aspace?
631          This is the post-redirection guest address.  Not that Vex
632          understands anything about redirection; that is all done on
633          the Valgrind side. */
634       Addr    guest_bytes_addr;
635 
636       /* Is it OK to chase into this guest address?  May not be
637 	 NULL. */
638       Bool    (*chase_into_ok) ( /*callback_opaque*/void*, Addr );
639 
640       /* OUT: which bits of guest code actually got translated */
641       VexGuestExtents* guest_extents;
642 
643       /* IN: a place to put the resulting code, and its size */
644       UChar*  host_bytes;
645       Int     host_bytes_size;
646       /* OUT: how much of the output area is used. */
647       Int*    host_bytes_used;
648 
649       /* IN: optionally, two instrumentation functions.  May be
650 	 NULL. */
651       IRSB*   (*instrument1) ( /*callback_opaque*/void*,
652                                IRSB*,
653                                const VexGuestLayout*,
654                                const VexGuestExtents*,
655                                const VexArchInfo*,
656                                IRType gWordTy, IRType hWordTy );
657       IRSB*   (*instrument2) ( /*callback_opaque*/void*,
658                                IRSB*,
659                                const VexGuestLayout*,
660                                const VexGuestExtents*,
661                                const VexArchInfo*,
662                                IRType gWordTy, IRType hWordTy );
663 
664       IRSB* (*finaltidy) ( IRSB* );
665 
666       /* IN: a callback used to ask the caller which of the extents,
667          if any, a self check is required for.  Must not be NULL.
668          The returned value is a bitmask with a 1 in position i indicating
669          that the i'th extent needs a check.  Since there can be at most
670          3 extents, the returned values must be between 0 and 7.
671 
672          This call also gives the VEX client the opportunity to change
673          the precision of register update preservation as performed by
674          the IR optimiser.  Before the call, VEX will set *pxControl
675          to hold the default register-update status value as specified
676          by VexControl::iropt_register_updates_default as passed to
677          LibVEX_Init at library initialisation time.  The client (in
678          this callback) can if it wants, inspect the value and change
679          it to something different, and that value will be used for
680          subsequent IR optimisation of the block. */
681       UInt (*needs_self_check)( /*callback_opaque*/void*,
682                                 /*MAYBE_MOD*/VexRegisterUpdates* pxControl,
683                                 const VexGuestExtents* );
684 
685       /* IN: optionally, a callback which allows the caller to add its
686          own IR preamble following the self-check and any other
687          VEX-generated preamble, if any.  May be NULL.  If non-NULL,
688          the IRSB under construction is handed to this function, which
689          presumably adds IR statements to it.  The callback may
690          optionally complete the block and direct bb_to_IR not to
691          disassemble any instructions into it; this is indicated by
692          the callback returning True.
693       */
694       Bool    (*preamble_function)(/*callback_opaque*/void*, IRSB*);
695 
696       /* IN: debug: trace vex activity at various points */
697       Int     traceflags;
698 
699       /* IN: debug: print diagnostics when an illegal instr is detected */
700       Bool    sigill_diag;
701 
702       /* IN: profiling: add a 64 bit profiler counter increment to the
703          translation? */
704       Bool    addProfInc;
705 
706       /* IN: address of the dispatcher entry points.  Describes the
707          places where generated code should jump to at the end of each
708          bb.
709 
710          At the end of each translation, the next guest address is
711          placed in the host's standard return register (x86: %eax,
712          amd64: %rax, ppc32: %r3, ppc64: %r3).  Optionally, the guest
713          state pointer register (on host x86: %ebp; amd64: %rbp;
714          ppc32/64: r31) may be set to a VEX_TRC_ value to indicate any
715          special action required before the next block is run.
716 
717          Control is then passed back to the dispatcher (beyond Vex's
718          control; caller supplies this) in the following way:
719 
720          - On host archs which lack a link register (x86, amd64), by a
721            jump to the host address specified in
722            'dispatcher_assisted', if the guest state pointer has been
723            changed so as to request some action before the next block
724            is run, or 'dispatcher_unassisted' (the fast path), in
725            which it is assumed that the guest state pointer is
726            unchanged and we wish to continue directly with the next
727            translation.  Both of these must be non-NULL.
728 
729          - On host archs which have a link register (ppc32, ppc64), by
730            a branch to the link register (which is guaranteed to be
731            unchanged from whatever it was at entry to the
732            translation).  'dispatch_assisted' and
733            'dispatch_unassisted' must be NULL.
734 
735          The aim is to get back and forth between translations and the
736          dispatcher without creating memory traffic to store return
737          addresses.
738 
739          FIXME: update this comment
740       */
741       const void* disp_cp_chain_me_to_slowEP;
742       const void* disp_cp_chain_me_to_fastEP;
743       const void* disp_cp_xindir;
744       const void* disp_cp_xassisted;
745    }
746    VexTranslateArgs;
747 
748 
749 extern
750 VexTranslateResult LibVEX_Translate ( VexTranslateArgs* );
751 
752 /* A subtlety re interaction between self-checking translations and
753    bb-chasing.  The supplied chase_into_ok function should say NO
754    (False) when presented with any address for which you might want to
755    make a self-checking translation.
756 
757    If it doesn't do that, you may end up with Vex chasing from BB #1
758    to BB #2 (fine); but if you wanted checking for #2 and not #1, that
759    would not be the result.  Therefore chase_into_ok should disallow
760    following into #2.  That will force the caller to eventually
761    request a new translation starting at #2, at which point Vex will
762    correctly observe the make-a-self-check flag.
763 
764    FIXME: is this still up to date? */
765 
766 
767 /*-------------------------------------------------------*/
768 /*--- Patch existing translations                     ---*/
769 /*-------------------------------------------------------*/
770 
771 /* A host address range that was modified by the functions below.
772    Callers must request I-cache syncing after the call as appropriate. */
773 typedef
774    struct {
775       HWord start;
776       HWord len;     /* always > 0 */
777    }
778    VexInvalRange;
779 
780 /* Chain an XDirect jump located at place_to_chain so it jumps to
781    place_to_jump_to.  It is expected (and checked) that this site
782    currently contains a call to the dispatcher specified by
783    disp_cp_chain_me_EXPECTED. */
784 extern
785 VexInvalRange LibVEX_Chain ( VexArch     arch_host,
786                              VexEndness  endhess_host,
787                              void*       place_to_chain,
788                              const void* disp_cp_chain_me_EXPECTED,
789                              const void* place_to_jump_to );
790 
791 /* Undo an XDirect jump located at place_to_unchain, so it is
792    converted back into a call to disp_cp_chain_me.  It is expected
793    (and checked) that this site currently contains a jump directly to
794    the address specified by place_to_jump_to_EXPECTED. */
795 extern
796 VexInvalRange LibVEX_UnChain ( VexArch     arch_host,
797                                VexEndness  endness_host,
798                                void*       place_to_unchain,
799                                const void* place_to_jump_to_EXPECTED,
800                                const void* disp_cp_chain_me );
801 
802 /* Returns a constant -- the size of the event check that is put at
803    the start of every translation.  This makes it possible to
804    calculate the fast entry point address if the slow entry point
805    address is known (the usual case), or vice versa. */
806 extern
807 Int LibVEX_evCheckSzB ( VexArch arch_host );
808 
809 
810 /* Patch the counter location into an existing ProfInc point.  The
811    specified point is checked to make sure it is plausible. */
812 extern
813 VexInvalRange LibVEX_PatchProfInc ( VexArch      arch_host,
814                                     VexEndness   endness_host,
815                                     void*        place_to_patch,
816                                     const ULong* location_of_counter );
817 
818 
819 /*-------------------------------------------------------*/
820 /*--- Show accumulated statistics                     ---*/
821 /*-------------------------------------------------------*/
822 
823 extern void LibVEX_ShowStats ( void );
824 
825 /*-------------------------------------------------------*/
826 /*-- IR injection                                      --*/
827 /*-------------------------------------------------------*/
828 
829 /* IR Injection Control Block */
830 
831 #define NO_ROUNDING_MODE (~0u)
832 
833 typedef
834    struct {
835       IROp  op;        // the operation to perform
836       HWord result;    // address of the result
837       HWord opnd1;     // address of 1st operand
838       HWord opnd2;     // address of 2nd operand
839       HWord opnd3;     // address of 3rd operand
840       HWord opnd4;     // address of 4th operand
841       IRType t_result; // type of result
842       IRType t_opnd1;  // type of 1st operand
843       IRType t_opnd2;  // type of 2nd operand
844       IRType t_opnd3;  // type of 3rd operand
845       IRType t_opnd4;  // type of 4th operand
846       UInt  rounding_mode;
847       UInt  num_operands; // excluding rounding mode, if any
848       Bool  shift_amount_is_immediate;
849    }
850    IRICB;
851 
852 extern void LibVEX_InitIRI ( const IRICB * );
853 
854 /*-------------------------------------------------------*/
855 /*--- Notes                                           ---*/
856 /*-------------------------------------------------------*/
857 
858 /* Code generation conventions that need to be recorded somewhere.
859    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
860 
861    x86
862    ~~~
863    Generated code should be entered using a JMP instruction.  On
864    entry, %ebp should point to the guest state, and %esp should be a
865    valid stack pointer.  The generated code may change %eax, %ebx,
866    %ecx, %edx, %esi, %edi, all the FP registers and control state, and
867    all the XMM registers.
868 
869    On entry, the FPU control word should be set to 0x027F, and the SSE
870    control word (%mxcsr) should be set to 0x1F80.  On exit, they
871    should still have those values (after masking off the lowest 6 bits
872    of %mxcsr).  If they don't, there is a bug in VEX-generated code.
873 
874    Generated code returns to the scheduler using a JMP instruction, to
875    the address specified in the .dispatch field of VexTranslateArgs.
876    %eax (or %eax:%edx, if simulating a 64-bit target) will contain the
877    guest address of the next block to execute.  %ebp may be changed
878    to a VEX_TRC_ value, otherwise it should be as it was at entry.
879 
880    CRITICAL ISSUES in x86 code generation.  The only known critical
881    issue is that the host FPU and SSE state is not properly saved
882    across calls to helper functions.  If any helper references any
883    such state, it is likely (1) to misbehave itself, since the FP
884    stack tags will not be as expected, and (2) after returning to
885    generated code, the generated code is likely to go wrong.  This
886    really should be fixed.
887 
888    amd64
889    ~~~~~
890    Analogous to x86.
891 
892    ppc32
893    ~~~~~
894    On entry, guest state pointer is r31.  .dispatch must be NULL.
895    Control is returned with a branch to the link register.  Generated
896    code will not change lr.  At return, r3 holds the next guest addr
897    (or r3:r4 ?).  r31 may be may be changed to a VEX_TRC_ value,
898    otherwise it should be as it was at entry.
899 
900    ppc64
901    ~~~~~
902    Same as ppc32.
903 
904    arm32
905    ~~~~~
906    r8 is GSP.
907 
908    arm64
909    ~~~~~
910    r21 is GSP.
911 
912    ALL GUEST ARCHITECTURES
913    ~~~~~~~~~~~~~~~~~~~~~~~
914    The guest state must contain two pseudo-registers, guest_CMSTART
915    and guest_CMLEN.  These are used to specify guest address ranges,
916    either of code to be invalidated, when used in conjunction with
917    Ijk_InvalICache, or of d-cache ranges to be flushed, when used in
918    conjunction with Ijk_FlushDCache.  In such cases, the two _CM
919    pseudo-regs should be filled in by the IR, and then an exit with
920    one of the two abovementioned Ijk_ kinds should happen, so that the
921    dispatcher can action them.  Both pseudo-regs must have size equal
922    to the guest word size.
923 
924    The architecture must a third pseudo-register, guest_NRADDR, also
925    guest-word-sized.  This is used to record the unredirected guest
926    address at the start of a translation whose start has been
927    redirected.  By reading this pseudo-register shortly afterwards,
928    the translation can find out what the corresponding no-redirection
929    address was.  Note, this is only set for wrap-style redirects, not
930    for replace-style ones.
931 */
932 #endif /* ndef __LIBVEX_H */
933 
934 /*---------------------------------------------------------------*/
935 /*---                                                libvex.h ---*/
936 /*---------------------------------------------------------------*/
937