blob: 3a82231a7b44282f8ee1dbacd98aed39ec11b282 [file] [log] [blame]
/*---------------------------------------------------------------*/
/*--- ---*/
/*--- This file (libvex.h) is ---*/
/*--- Copyright (C) OpenWorks LLP. All rights reserved. ---*/
/*--- ---*/
/*---------------------------------------------------------------*/
/*
This file is part of LibVEX, a library for dynamic binary
instrumentation and translation.
Copyright (C) 2004-2008 OpenWorks LLP. All rights reserved.
This library is made available under a dual licensing scheme.
If you link LibVEX against other code all of which is itself
licensed under the GNU General Public License, version 2 dated June
1991 ("GPL v2"), then you may use LibVEX under the terms of the GPL
v2, as appearing in the file LICENSE.GPL. If the file LICENSE.GPL
is missing, you can obtain a copy of the GPL v2 from the Free
Software Foundation Inc., 51 Franklin St, Fifth Floor, Boston, MA
02110-1301, USA.
For any other uses of LibVEX, you must first obtain a commercial
license from OpenWorks LLP. Please contact info@open-works.co.uk
for information about commercial licensing.
This software is provided by OpenWorks LLP "as is" and any express
or implied warranties, including, but not limited to, the implied
warranties of merchantability and fitness for a particular purpose
are disclaimed. In no event shall OpenWorks LLP be liable for any
direct, indirect, incidental, special, exemplary, or consequential
damages (including, but not limited to, procurement of substitute
goods or services; loss of use, data, or profits; or business
interruption) however caused and on any theory of liability,
whether in contract, strict liability, or tort (including
negligence or otherwise) arising in any way out of the use of this
software, even if advised of the possibility of such damage.
Neither the names of the U.S. Department of Energy nor the
University of California nor the names of its contributors may be
used to endorse or promote products derived from this software
without prior written permission.
*/
#ifndef __LIBVEX_H
#define __LIBVEX_H
#include "libvex_basictypes.h"
#include "libvex_ir.h"
/*---------------------------------------------------------------*/
/*--- This file defines the top-level interface to LibVEX. ---*/
/*---------------------------------------------------------------*/
/*-------------------------------------------------------*/
/*--- Architectures, variants, and other arch info ---*/
/*-------------------------------------------------------*/
typedef
enum {
VexArch_INVALID,
VexArchX86,
VexArchAMD64,
VexArchARM,
VexArchPPC32,
VexArchPPC64
}
VexArch;
/* For a given architecture, these specify extra capabilities beyond
the minimum supported (baseline) capabilities. They may be OR'd
together, although some combinations don't make sense. (eg, SSE2
but not SSE1). LibVEX_Translate will check for nonsensical
combinations. */
/* x86: baseline capability is Pentium-1 (FPU, MMX, but no SSE), with
cmpxchg8b. */
#define VEX_HWCAPS_X86_SSE1 (1<<1) /* SSE1 support (Pentium III) */
#define VEX_HWCAPS_X86_SSE2 (1<<2) /* SSE2 support (Pentium 4) */
#define VEX_HWCAPS_X86_SSE3 (1<<3) /* SSE3 support (>= Prescott) */
/* amd64: baseline capability is SSE2, with cmpxchg8b but not
cmpxchg16b. */
#define VEX_HWCAPS_AMD64_SSE3 (1<<4) /* SSE3 support */
#define VEX_HWCAPS_AMD64_CX16 (1<<5) /* cmpxchg16b support */
/* ppc32: baseline capability is integer only */
#define VEX_HWCAPS_PPC32_F (1<<6) /* basic (non-optional) FP */
#define VEX_HWCAPS_PPC32_V (1<<7) /* Altivec (VMX) */
#define VEX_HWCAPS_PPC32_FX (1<<8) /* FP extns (fsqrt, fsqrts) */
#define VEX_HWCAPS_PPC32_GX (1<<9) /* Graphics extns
(fres,frsqrte,fsel,stfiwx) */
/* ppc64: baseline capability is integer and basic FP insns */
#define VEX_HWCAPS_PPC64_V (1<<10) /* Altivec (VMX) */
#define VEX_HWCAPS_PPC64_FX (1<<11) /* FP extns (fsqrt, fsqrts) */
#define VEX_HWCAPS_PPC64_GX (1<<12) /* Graphics extns
(fres,frsqrte,fsel,stfiwx) */
/* arm: baseline capability is ARMv4 */
/* No extra capabilities */
/* These return statically allocated strings. */
extern const HChar* LibVEX_ppVexArch ( VexArch );
extern const HChar* LibVEX_ppVexHwCaps ( VexArch, UInt );
/* This struct is a bit of a hack, but is needed to carry misc
important bits of info about an arch. Fields which are meaningless
or ignored for the platform in question should be set to zero. */
typedef
struct {
/* This is the only mandatory field. */
UInt hwcaps;
/* PPC32/PPC64 only: size of cache line */
Int ppc_cache_line_szB;
}
VexArchInfo;
/* Write default settings info *vai. */
extern
void LibVEX_default_VexArchInfo ( /*OUT*/VexArchInfo* vai );
/* This struct carries guest and host ABI variant information that may
be needed. Fields which are meaningless or ignored for the
platform in question should be set to zero.
Settings which are believed to be correct are:
guest_stack_redzone_size
guest is ppc32-linux ==> 0
guest is ppc64-linux ==> 288
guest is ppc32-aix5 ==> 220
guest is ppc64-aix5 ==> unknown
guest is amd64-linux ==> 128
guest is other ==> inapplicable
guest_amd64_assume_fs_is_zero
guest is amd64-linux ==> True
guest is amd64-darwin ==> False
guest is other ==> inapplicable
guest_amd64_assume_gs_is_0x60
guest is amd64-darwin ==> True
guest is amd64-linux ==> False
guest is other ==> inapplicable
guest_ppc_zap_RZ_at_blr
guest is ppc64-linux ==> True
guest is ppc32-linux ==> False
guest is ppc64-aix5 ==> unknown
guest is ppc32-aix5 ==> False
guest is other ==> inapplicable
guest_ppc_zap_RZ_at_bl
guest is ppc64-linux ==> const True
guest is ppc32-linux ==> const False
guest is ppc64-aix5 ==> unknown
guest is ppc32-aix5 ==> True except for calls to
millicode, $SAVEFn, $RESTFn
guest is other ==> inapplicable
guest_ppc_sc_continues_at_LR:
guest is ppc32-aix5 or ppc64-aix5 ==> True
guest is ppc32-linux or ppc64-linux ==> False
guest is other ==> inapplicable
host_ppc_calls_use_fndescrs:
host is ppc32-linux ==> False
host is ppc64-linux ==> True
host is ppc32-aix5 or ppc64-aix5 ==> True
host is other ==> inapplicable
host_ppc32_regalign_int64_args:
host is ppc32-linux ==> True
host is ppc32-aix5 ==> False
host is other ==> inapplicable
*/
typedef
struct {
/* PPC and AMD64 GUESTS only: how many bytes below the
stack pointer are validly addressible? */
Int guest_stack_redzone_size;
/* AMD64 GUESTS only: should we translate %fs-prefixed
instructions using the assumption that %fs always contains
zero? */
Bool guest_amd64_assume_fs_is_zero;
/* AMD64 GUESTS only: should we translate %gs-prefixed
instructions using the assumption that %gs always contains
0x60? */
Bool guest_amd64_assume_gs_is_0x60;
/* PPC GUESTS only: should we zap the stack red zone at a 'blr'
(function return) ? */
Bool guest_ppc_zap_RZ_at_blr;
/* PPC GUESTS only: should we zap the stack red zone at a 'bl'
(function call) ? Is supplied with the guest address of the
target of the call since that may be significant. If NULL,
is assumed equivalent to a fn which always returns False. */
Bool (*guest_ppc_zap_RZ_at_bl)(Addr64);
/* PPC32/PPC64 GUESTS only: where does the kernel resume after
'sc'? False => Linux style, at the next insn. True => AIX
style, at the address stated in the link register. */
Bool guest_ppc_sc_continues_at_LR;
/* PPC32/PPC64 HOSTS only: does '&f' give us a pointer to a
function descriptor on the host, or to the function code
itself? True => descriptor, False => code. */
Bool host_ppc_calls_use_fndescrs;
/* PPC32 HOSTS only: when generating code to pass a 64-bit value
(actual parameter) in a pair of regs, should we skip an arg
reg if it is even-numbered? True => yes, False => no. */
Bool host_ppc32_regalign_int64_args;
}
VexAbiInfo;
/* Write default settings info *vbi. */
extern
void LibVEX_default_VexAbiInfo ( /*OUT*/VexAbiInfo* vbi );
/*-------------------------------------------------------*/
/*--- Control of Vex's optimiser (iropt). ---*/
/*-------------------------------------------------------*/
/* Control of Vex's optimiser. */
typedef
struct {
/* Controls verbosity of iropt. 0 = no output. */
Int iropt_verbosity;
/* Control aggressiveness of iropt. 0 = no opt, 1 = simple
opts, 2 (default) = max optimisation. */
Int iropt_level;
/* Ensure all integer registers are up to date at potential
memory exception points? True(default)=yes, False=no, only
the guest's stack pointer. */
Bool iropt_precise_memory_exns;
/* How aggressive should iropt be in unrolling loops? Higher
numbers make it more enthusiastic about loop unrolling.
Default=120. A setting of zero disables unrolling. */
Int iropt_unroll_thresh;
/* What's the maximum basic block length the front end(s) allow?
BBs longer than this are split up. Default=50 (guest
insns). */
Int guest_max_insns;
/* How aggressive should front ends be in following
unconditional branches to known destinations? Default=10,
meaning that if a block contains less than 10 guest insns so
far, the front end(s) will attempt to chase into its
successor. A setting of zero disables chasing. */
Int guest_chase_thresh;
}
VexControl;
/* Write the default settings into *vcon. */
extern
void LibVEX_default_VexControl ( /*OUT*/ VexControl* vcon );
/*-------------------------------------------------------*/
/*--- Version information ---*/
/*-------------------------------------------------------*/
/* Returns the Vex SVN version, as a statically allocated string. */
extern const HChar* LibVEX_Version ( void );
/*-------------------------------------------------------*/
/*--- Storage management control ---*/
/*-------------------------------------------------------*/
/* Allocate in Vex's temporary allocation area. Be careful with this.
You can only call it inside an instrumentation or optimisation
callback that you have previously specified in a call to
LibVEX_Translate. The storage allocated will only stay alive until
translation of the current basic block is complete.
*/
extern HChar* private_LibVEX_alloc_first;
extern HChar* private_LibVEX_alloc_curr;
extern HChar* private_LibVEX_alloc_last;
extern void private_LibVEX_alloc_OOM(void) __attribute__((noreturn));
static inline void* LibVEX_Alloc ( Int nbytes )
{
#if 0
/* Nasty debugging hack, do not use. */
return malloc(nbytes);
#else
HChar* curr;
HChar* next;
Int ALIGN;
ALIGN = sizeof(void*)-1;
nbytes = (nbytes + ALIGN) & ~ALIGN;
curr = private_LibVEX_alloc_curr;
next = curr + nbytes;
if (next >= private_LibVEX_alloc_last)
private_LibVEX_alloc_OOM();
private_LibVEX_alloc_curr = next;
return curr;
#endif
}
/* Show Vex allocation statistics. */
extern void LibVEX_ShowAllocStats ( void );
/*-------------------------------------------------------*/
/*--- Describing guest state layout ---*/
/*-------------------------------------------------------*/
/* Describe the guest state enough that the instrumentation
functions can work. */
/* The max number of guest state chunks which we can describe as
always defined (for the benefit of Memcheck). */
#define VEXGLO_N_ALWAYSDEFD 24
typedef
struct {
/* Total size of the guest state, in bytes. Must be
8-aligned. */
Int total_sizeB;
/* Whereabouts is the stack pointer? */
Int offset_SP;
Int sizeof_SP; /* 4 or 8 */
/* Whereabouts is the frame pointer? */
Int offset_FP;
Int sizeof_FP; /* 4 or 8 */
/* Whereabouts is the instruction pointer? */
Int offset_IP;
Int sizeof_IP; /* 4 or 8 */
/* Describe parts of the guest state regarded as 'always
defined'. */
Int n_alwaysDefd;
struct {
Int offset;
Int size;
} alwaysDefd[VEXGLO_N_ALWAYSDEFD];
}
VexGuestLayout;
/* A note about guest state layout.
LibVEX defines the layout for the guest state, in the file
pub/libvex_guest_<arch>.h. The struct will have an 16-aligned
size. Each translated bb is assumed to be entered with a specified
register pointing at such a struct. Beyond that is two copies of
the shadow state area with the same size as the struct. Beyond
that is a spill area that LibVEX may spill into. It must have size
LibVEX_N_SPILL_BYTES, and this must be a 16-aligned number.
On entry, the baseblock pointer register must be 16-aligned.
There must be no holes in between the primary guest state, its two
copies, and the spill area. In short, all 4 areas must have a
16-aligned size and be 16-aligned, and placed back-to-back.
*/
#define LibVEX_N_SPILL_BYTES 2048
/*-------------------------------------------------------*/
/*--- Initialisation of the library ---*/
/*-------------------------------------------------------*/
/* Initialise the library. You must call this first. */
extern void LibVEX_Init (
/* failure exit function */
__attribute__ ((noreturn))
void (*failure_exit) ( void ),
/* logging output function */
void (*log_bytes) ( HChar*, Int nbytes ),
/* debug paranoia level */
Int debuglevel,
/* Are we supporting valgrind checking? */
Bool valgrind_support,
/* Control ... */
/*READONLY*/VexControl* vcon
);
/*-------------------------------------------------------*/
/*--- Make a translation ---*/
/*-------------------------------------------------------*/
/* Describes the outcome of a translation attempt. */
typedef
enum {
VexTransOK,
VexTransAccessFail,
VexTransOutputFull
}
VexTranslateResult;
/* Describes precisely the pieces of guest code that a translation
covers. Now that Vex can chase across BB boundaries, the old
scheme of describing a chunk of guest code merely by its start
address and length is inadequate.
Hopefully this struct is only 32 bytes long. Space is important as
clients will have to store one of these for each translation made.
*/
typedef
struct {
Addr64 base[3];
UShort len[3];
UShort n_used;
}
VexGuestExtents;
/* A structure to carry arguments for LibVEX_Translate. There are so
many of them, it seems better to have a structure. */
typedef
struct {
/* IN: The instruction sets we are translating from and to. And
guest/host misc info. */
VexArch arch_guest;
VexArchInfo archinfo_guest;
VexArch arch_host;
VexArchInfo archinfo_host;
VexAbiInfo abiinfo_both;
/* IN: an opaque value which is passed as the first arg to all
callback functions supplied in this struct. Vex has no idea
what's at the other end of this pointer. */
void* callback_opaque;
/* IN: the block to translate, and its guest address. */
/* where are the actual bytes in the host's address space? */
UChar* guest_bytes;
/* where do the bytes really come from in the guest's aspace?
This is the post-redirection guest address. Not that Vex
understands anything about redirection; that is all done on
the Valgrind side. */
Addr64 guest_bytes_addr;
/* Is it OK to chase into this guest address? May not be
NULL. */
Bool (*chase_into_ok) ( /*callback_opaque*/void*, Addr64 );
/* OUT: which bits of guest code actually got translated */
VexGuestExtents* guest_extents;
/* IN: a place to put the resulting code, and its size */
UChar* host_bytes;
Int host_bytes_size;
/* OUT: how much of the output area is used. */
Int* host_bytes_used;
/* IN: optionally, two instrumentation functions. May be
NULL. */
IRSB* (*instrument1) ( /*callback_opaque*/void*,
IRSB*,
VexGuestLayout*,
VexGuestExtents*,
IRType gWordTy, IRType hWordTy );
IRSB* (*instrument2) ( /*callback_opaque*/void*,
IRSB*,
VexGuestLayout*,
VexGuestExtents*,
IRType gWordTy, IRType hWordTy );
IRSB* (*finaltidy) ( IRSB* );
/* IN: should this translation be self-checking? default: False */
Bool do_self_check;
/* IN: optionally, a callback which allows the caller to add its
own IR preamble following the self-check and any other
VEX-generated preamble, if any. May be NULL. If non-NULL,
the IRSB under construction is handed to this function, which
presumably adds IR statements to it. The callback may
optionally complete the block and direct bb_to_IR not to
disassemble any instructions into it; this is indicated by
the callback returning True.
*/
Bool (*preamble_function)(/*callback_opaque*/void*, IRSB*);
/* IN: debug: trace vex activity at various points */
Int traceflags;
/* IN: address of the dispatcher entry point. Describes the
place where generated code should jump to at the end of each
bb.
At the end of each translation, the next guest address is
placed in the host's standard return register (x86: %eax,
amd64: %rax, ppc32: %r3, ppc64: %r3). Optionally, the guest
state pointer register (on host x86: %ebp; amd64: %rbp;
ppc32/64: r31) may be set to a VEX_TRC_ value to indicate any
special action required before the next block is run.
Control is then passed back to the dispatcher (beyond Vex's
control; caller supplies this) in the following way:
- On host archs which lack a link register (x86, amd64), by a
jump to the host address specified in 'dispatcher', which
must be non-NULL.
- On host archs which have a link register (ppc32, ppc64), by
a branch to the link register (which is guaranteed to be
unchanged from whatever it was at entry to the
translation). 'dispatch' must be NULL.
The aim is to get back and forth between translations and the
dispatcher without creating memory traffic to store return
addresses.
*/
void* dispatch;
}
VexTranslateArgs;
extern
VexTranslateResult LibVEX_Translate ( VexTranslateArgs* );
/* A subtlety re interaction between self-checking translations and
bb-chasing. The supplied chase_into_ok function should say NO
(False) when presented with any address for which you might want to
make a self-checking translation.
If it doesn't do that, you may end up with Vex chasing from BB #1
to BB #2 (fine); but if you wanted checking for #2 and not #1, that
would not be the result. Therefore chase_into_ok should disallow
following into #2. That will force the caller to eventually
request a new translation starting at #2, at which point Vex will
correctly observe the make-a-self-check flag. */
/*-------------------------------------------------------*/
/*--- Show accumulated statistics ---*/
/*-------------------------------------------------------*/
extern void LibVEX_ShowStats ( void );
/*-------------------------------------------------------*/
/*--- Notes ---*/
/*-------------------------------------------------------*/
/* Code generation conventions that need to be recorded somewhere.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
x86
~~~
Generated code should be entered using a JMP instruction. On
entry, %ebp should point to the guest state, and %esp should be a
valid stack pointer. The generated code may change %eax, %ebx,
%ecx, %edx, %esi, %edi, all the FP registers and control state, and
all the XMM registers.
On entry, the FPU control word should be set to 0x027F, and the SSE
control word (%mxcsr) should be set to 0x1F80. On exit, they
should still have those values (after masking off the lowest 6 bits
of %mxcsr). If they don't, there is a bug in VEX-generated code.
Generated code returns to the scheduler using a JMP instruction, to
the address specified in the .dispatch field of VexTranslateArgs.
%eax (or %eax:%edx, if simulating a 64-bit target) will contain the
guest address of the next block to execute. %ebp may be changed
to a VEX_TRC_ value, otherwise it should be as it was at entry.
CRITICAL ISSUES in x86 code generation. The only known critical
issue is that the host FPU and SSE state is not properly saved
across calls to helper functions. If any helper references any
such state, it is likely (1) to misbehave itself, since the FP
stack tags will not be as expected, and (2) after returning to
generated code, the generated code is likely to go wrong. This
really should be fixed.
amd64
~~~~~
Analogous to x86.
ppc32
~~~~~
On entry, guest state pointer is r31. .dispatch must be NULL.
Control is returned with a branch to the link register. Generated
code will not change lr. At return, r3 holds the next guest addr
(or r3:r4 ?). r31 may be may be changed to a VEX_TRC_ value,
otherwise it should be as it was at entry.
ppc64
~~~~~
Same as ppc32.
ALL GUEST ARCHITECTURES
~~~~~~~~~~~~~~~~~~~~~~~
The guest state must contain two pseudo-registers, guest_TISTART
and guest_TILEN. These are used to pass the address of areas of
guest code, translations of which are to be invalidated, back to
the despatcher. Both pseudo-regs must have size equal to the guest
word size.
The architecture must a third pseudo-register, guest_NRADDR, also
guest-word-sized. This is used to record the unredirected guest
address at the start of a translation whose start has been
redirected. By reading this pseudo-register shortly afterwards,
the translation can find out what the corresponding no-redirection
address was. Note, this is only set for wrap-style redirects, not
for replace-style ones.
*/
#endif /* ndef __LIBVEX_H */
/*---------------------------------------------------------------*/
/*--- libvex.h ---*/
/*---------------------------------------------------------------*/