1 
2 /*--------------------------------------------------------------------*/
3 /*--- begin                               guest_generic_bb_to_IR.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 #ifndef __VEX_GUEST_GENERIC_BB_TO_IR_H
37 #define __VEX_GUEST_GENERIC_BB_TO_IR_H
38 
39 #include "libvex_basictypes.h"
40 #include "libvex_ir.h"              // IRJumpKind
41 #include "libvex.h"                 // VexArch
42 
43 /* This defines stuff needed by the guest insn disassemblers.
44    It's a bit circular; is imported by
45    - the guest-specific toIR.c files (guest-{x86,amd64,ppc,arm}/toIR.c)
46    - the generic disassembly driver (bb_to_IR.c)
47    - vex_main.c
48 */
49 
50 
51 /* ---------------------------------------------------------------
52    Result of disassembling an instruction
53    --------------------------------------------------------------- */
54 
55 /* The results of disassembling an instruction.  There are three
56    possible outcomes.  For Dis_Resteer, the disassembler _must_
57    continue at the specified address.  For Dis_StopHere, the
58    disassembler _must_ terminate the BB.  For Dis_Continue, we may at
59    our option either disassemble the next insn, or terminate the BB;
60    but in the latter case we must set the bb's ->next field to point
61    to the next instruction.  */
62 
63 typedef
64 
65    struct {
66 
67       /* The disassembled insn has this length.  Must always be
68          set. */
69       UInt len;
70 
71       /* What happens next?
72          Dis_StopHere:  this insn terminates the BB; we must stop.
73          Dis_Continue:  we can optionally continue into the next insn
74          Dis_ResteerU:  followed an unconditional branch; continue at
75                         'continueAt'
76          Dis_ResteerC:  (speculatively, of course) followed a
77                         conditional branch; continue at 'continueAt'
78       */
79       enum { Dis_StopHere=0x10, Dis_Continue,
80              Dis_ResteerU, Dis_ResteerC } whatNext;
81 
82       /* Any other hints that we should feed back to the disassembler?
83          Dis_HintNone:     no hint
84          Dis_HintVerbose:  this insn potentially generates a lot of code
85       */
86       enum { Dis_HintNone=0x20, Dis_HintVerbose } hint;
87 
88       /* For whatNext==Dis_StopHere, we need to end the block and create a
89          transfer to whatever the NIA is.  That will have presumably
90          been set by the IR generated for this insn.  So we need to
91          know the jump kind to use.  Should Ijk_INVALID in other Dis_
92          cases. */
93       IRJumpKind jk_StopHere;
94 
95       /* For Dis_Resteer, this is the guest address we should continue
96          at.  Otherwise ignored (should be zero). */
97       Addr   continueAt;
98    }
99 
100    DisResult;
101 
102 
103 /* ---------------------------------------------------------------
104    The type of a function which disassembles one instruction.
105    C's function-type syntax is really astonishing bizarre.
106    --------------------------------------------------------------- */
107 
108 /* A function of this type (DisOneInstrFn) disassembles an instruction
109    located at host address &guest_code[delta], whose guest IP is
110    guest_IP (this may be entirely unrelated to where the insn is
111    actually located in the host's address space.).  The returned
112    DisResult.len field carries its size.  If the returned
113    DisResult.whatNext field is Dis_Resteer then DisResult.continueAt
114    should hold the guest IP of the next insn to disassemble.
115 
116    disInstr is not permitted to return Dis_Resteer if resteerOkFn,
117    when applied to the address which it wishes to resteer into,
118    returns False.
119 
120    The resulting IR is added to the end of irbb.
121 */
122 
123 typedef
124 
125    DisResult (*DisOneInstrFn) (
126 
127       /* This is the IRSB to which the resulting IR is to be appended. */
128       /*OUT*/ IRSB*        irbb,
129 
130       /* Return True iff resteering to the given addr is allowed (for
131          branches/calls to destinations that are known at JIT-time) */
132       /*IN*/  Bool         (*resteerOkFn) ( /*opaque*/void*, Addr ),
133 
134       /* Should we speculatively resteer across conditional branches?
135          (Experimental and not enabled by default).  The strategy is
136          to assume that backward branches are taken and forward
137          branches are not taken. */
138       /*IN*/  Bool         resteerCisOk,
139 
140       /* Vex-opaque data passed to all caller (valgrind) supplied
141          callbacks. */
142       /*IN*/  void*        callback_opaque,
143 
144       /* Where is the guest code? */
145       /*IN*/  const UChar* guest_code,
146 
147       /* Where is the actual insn?  Note: it's at &guest_code[delta] */
148       /*IN*/  Long         delta,
149 
150       /* What is the guest IP of the insn? */
151       /*IN*/  Addr         guest_IP,
152 
153       /* Info about the guest architecture */
154       /*IN*/  VexArch      guest_arch,
155       /*IN*/  const VexArchInfo* archinfo,
156 
157       /* ABI info for both guest and host */
158       /*IN*/  const VexAbiInfo*  abiinfo,
159 
160       /* The endianness of the host */
161       /*IN*/  VexEndness   host_endness,
162 
163       /* Should diagnostics be printed for illegal instructions? */
164       /*IN*/  Bool         sigill_diag
165 
166    );
167 
168 
169 /* ---------------------------------------------------------------
170    Top-level BB to IR conversion fn.
171    --------------------------------------------------------------- */
172 
173 /* See detailed comment in guest_generic_bb_to_IR.c. */
174 extern
175 IRSB* bb_to_IR (
176          /*OUT*/VexGuestExtents* vge,
177          /*OUT*/UInt*            n_sc_extents,
178          /*OUT*/UInt*            n_guest_instrs, /* stats only */
179          /*MOD*/VexRegisterUpdates* pxControl,
180          /*IN*/ void*            callback_opaque,
181          /*IN*/ DisOneInstrFn    dis_instr_fn,
182          /*IN*/ const UChar*     guest_code,
183          /*IN*/ Addr             guest_IP_bbstart,
184          /*IN*/ Bool             (*chase_into_ok)(void*,Addr),
185          /*IN*/ VexEndness       host_endness,
186          /*IN*/ Bool             sigill_diag,
187          /*IN*/ VexArch          arch_guest,
188          /*IN*/ const VexArchInfo* archinfo_guest,
189          /*IN*/ const VexAbiInfo*  abiinfo_both,
190          /*IN*/ IRType           guest_word_type,
191          /*IN*/ UInt             (*needs_self_check)
192                                     (void*, /*MB_MOD*/VexRegisterUpdates*,
193                                             const VexGuestExtents*),
194          /*IN*/ Bool             (*preamble_function)(void*,IRSB*),
195          /*IN*/ Int              offB_GUEST_CMSTART,
196          /*IN*/ Int              offB_GUEST_CMLEN,
197          /*IN*/ Int              offB_GUEST_IP,
198          /*IN*/ Int              szB_GUEST_IP
199       );
200 
201 
202 #endif /* ndef __VEX_GUEST_GENERIC_BB_TO_IR_H */
203 
204 /*--------------------------------------------------------------------*/
205 /*--- end                                 guest_generic_bb_to_IR.h ---*/
206 /*--------------------------------------------------------------------*/
207