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tnt_main.c
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tnt_main.c
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/*--------------------------------------------------------------------*/
/*--- Taintgrind: The taint analysis Valgrind tool. tnt_main.c ---*/
/*--------------------------------------------------------------------*/
/*
This file is part of Taintgrind, the taint analysis Valgrind tool.
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307, USA.
The GNU General Public License is contained in the file COPYING.
*/
#include "pub_tool_basics.h"
#include "pub_tool_tooliface.h"
#include "pub_tool_vki.h" // keeps libcproc.h happy
#include "pub_tool_aspacemgr.h" // VG_(am_shadow_alloc)
#include "pub_tool_debuginfo.h" // VG_(get_fnname_w_offset), VG_(get_fnname)
#include "pub_tool_hashtable.h" // For tnt_include.h, VgHashtable
#include "pub_tool_libcassert.h" // tl_assert
#include "pub_tool_libcbase.h" // VG_STREQN
#include "pub_tool_libcprint.h" // VG_(message)
#include "pub_tool_libcproc.h" // VG_(getenv)
#include "pub_tool_replacemalloc.h" // VG_(replacement_malloc_process_cmd_line_option)
#include "pub_tool_machine.h" // VG_(get_IP)
#include "pub_tool_mallocfree.h" // VG_(out_of_memory_NORETURN)
#include "pub_tool_options.h" // VG_STR/BHEX/BINT_CLO
#include "pub_tool_oset.h" // OSet operations
#include "pub_tool_threadstate.h" // VG_(get_running_tid)
#include "pub_tool_xarray.h" // VG_(*XA)
#include "pub_tool_stacktrace.h" // VG_(get_and_pp_StackTrace)
#include "tnt_include.h"
#include "tnt_strings.h"
#include "tnt_structs.h"
/*------------------------------------------------------------*/
/*--- Fast-case knobs ---*/
/*------------------------------------------------------------*/
// Comment these out to disable the fast cases (don't just set them to zero).
#define PERF_FAST_LOADV 1
#define PERF_FAST_STOREV 1
#define PERF_FAST_SARP 1
/*---------- Taintgrind DEBUG statements---------*/
//#define DBG_MEM
//#define DBG_LOAD
//#define DBG_STORE
//#define DBG_COPY_ADDR_RANGE_STATE
/* --------------- Basic configuration --------------- */
/* Only change this. N_PRIMARY_MAP *must* be a power of 2. */
#if VG_WORDSIZE == 4
/* cover the entire address space */
# define N_PRIMARY_BITS 16
#else
/* Just handle the first 32G fast and the rest via auxiliary
primaries. If you change this, Memcheck will assert at startup.
See the definition of UNALIGNED_OR_HIGH for extensive comments. */
# define N_PRIMARY_BITS 19
#endif
/* Do not change this. */
#define N_PRIMARY_MAP ( ((UWord)1) << N_PRIMARY_BITS)
/* Do not change this. */
#define MAX_PRIMARY_ADDRESS (Addr)((((Addr)65536) * N_PRIMARY_MAP)-1)
// These represent eight bits of memory.
#define VA_BITS2_NOACCESS 0x0 // 00b
#define VA_BITS2_TAINTED 0x1 // 01b
#define VA_BITS2_UNTAINTED 0x2 // 10b
#define VA_BITS2_PARTUNTAINTED 0x3 // 11b
// These represent 16 bits of memory.
#define VA_BITS4_NOACCESS 0x0 // 00_00b
#define VA_BITS4_TAINTED 0x5 // 01_01b
#define VA_BITS4_UNTAINTED 0xa // 10_10b
// These represent 32 bits of memory.
#define VA_BITS8_NOACCESS 0x00 // 00_00_00_00b
#define VA_BITS8_TAINTED 0x55 // 01_01_01_01b
#define VA_BITS8_UNTAINTED 0xaa // 10_10_10_10b
// These represent 64 bits of memory.
#define VA_BITS16_NOACCESS 0x0000 // 00_00_00_00b x 2
#define VA_BITS16_TAINTED 0x5555 // 01_01_01_01b x 2
#define VA_BITS16_UNTAINTED 0xaaaa // 10_10_10_10b x 2
#define SM_CHUNKS 16384
#define SM_OFF(aaa) (((aaa) & 0xffff) >> 2)
#define SM_OFF_16(aaa) (((aaa) & 0xffff) >> 3)
// Paranoia: it's critical for performance that the requested inlining
// occurs. So try extra hard.
#define INLINE inline __attribute__((always_inline))
static INLINE Addr start_of_this_sm ( Addr a ) {
return (a & (~SM_MASK));
}
static INLINE Bool is_start_of_sm ( Addr a ) {
return (start_of_this_sm(a) == a);
}
typedef
struct {
UChar vabits8[SM_CHUNKS];
}
SecMap;
// 3 distinguished secondary maps, one for no-access, one for
// accessible but undefined, and one for accessible and defined.
// Distinguished secondaries may never be modified.
#define SM_DIST_NOACCESS 0
#define SM_DIST_TAINTED 1
#define SM_DIST_UNTAINTED 2
static SecMap sm_distinguished[3];
static INLINE Bool is_distinguished_sm ( SecMap* sm ) {
return sm >= &sm_distinguished[0] && sm <= &sm_distinguished[2];
}
// Forward declaration
Int ctoi( HChar c );
Int ctoi_test( HChar c );
Int atoi( HChar *s );
Char decode_char( UInt num );
void decode_string( UInt *enc, HChar *aStr );
void post_decode_string( HChar *aStr );
void post_decode_string_load( HChar *aStr );
void post_decode_string_primops( HChar *aStr );
void post_decode_string_binops( HChar *aStr );
void post_decode_string_store( HChar *aStr );
void post_decode_string_ite( HChar *aStr );
Int get_and_check_reg( HChar *reg );
Int get_and_check_tvar( HChar *tmp );
static void update_SM_counts(SecMap* oldSM, SecMap* newSM); //285
/* dist_sm points to one of our three distinguished secondaries. Make
a copy of it so that we can write to it.
*/
static SecMap* copy_for_writing ( SecMap* dist_sm )
{
SecMap* new_sm;
tl_assert(dist_sm == &sm_distinguished[0]
|| dist_sm == &sm_distinguished[1]
|| dist_sm == &sm_distinguished[2]);
new_sm = VG_(am_shadow_alloc)(sizeof(SecMap));
if (new_sm == NULL)
VG_(out_of_memory_NORETURN)( "memcheck:allocate new SecMap",
sizeof(SecMap) );
VG_(memcpy)(new_sm, dist_sm, sizeof(SecMap));
update_SM_counts(dist_sm, new_sm);
return new_sm;
}
/* --------------- Stats --------------- */
static Int n_issued_SMs = 0;
static Int n_deissued_SMs = 0;
static Int n_noaccess_SMs = N_PRIMARY_MAP; // start with many noaccess DSMs
static Int n_undefined_SMs = 0;
static Int n_defined_SMs = 0;
static Int n_non_DSM_SMs = 0;
static Int max_noaccess_SMs = 0;
static Int max_undefined_SMs = 0;
static Int max_defined_SMs = 0;
static Int max_non_DSM_SMs = 0;
/* # searches initiated in auxmap_L1, and # base cmps required */
static ULong n_auxmap_L1_searches = 0;
static ULong n_auxmap_L1_cmps = 0;
/* # of searches that missed in auxmap_L1 and therefore had to
be handed to auxmap_L2. And the number of nodes inserted. */
static ULong n_auxmap_L2_searches = 0;
static ULong n_auxmap_L2_nodes = 0;
//static Int n_sanity_cheap = 0;
//static Int n_sanity_expensive = 0;
static Int n_secVBit_nodes = 0;
static Int max_secVBit_nodes = 0;
static void update_SM_counts(SecMap* oldSM, SecMap* newSM)
{
if (oldSM == &sm_distinguished[SM_DIST_NOACCESS ]) n_noaccess_SMs --;
else if (oldSM == &sm_distinguished[SM_DIST_TAINTED]) n_undefined_SMs--;
else if (oldSM == &sm_distinguished[SM_DIST_UNTAINTED ]) n_defined_SMs --;
else { n_non_DSM_SMs --;
n_deissued_SMs ++; }
if (newSM == &sm_distinguished[SM_DIST_NOACCESS ]) n_noaccess_SMs ++;
else if (newSM == &sm_distinguished[SM_DIST_TAINTED]) n_undefined_SMs++;
else if (newSM == &sm_distinguished[SM_DIST_UNTAINTED ]) n_defined_SMs ++;
else { n_non_DSM_SMs ++;
n_issued_SMs ++; }
if (n_noaccess_SMs > max_noaccess_SMs ) max_noaccess_SMs = n_noaccess_SMs;
if (n_undefined_SMs > max_undefined_SMs) max_undefined_SMs = n_undefined_SMs;
if (n_defined_SMs > max_defined_SMs ) max_defined_SMs = n_defined_SMs;
if (n_non_DSM_SMs > max_non_DSM_SMs ) max_non_DSM_SMs = n_non_DSM_SMs;
}
/* --------------- Primary maps --------------- */
/* The main primary map. This covers some initial part of the address
space, addresses 0 .. (N_PRIMARY_MAP << 16)-1. The rest of it is
handled using the auxiliary primary map.
*/
static SecMap* primary_map[N_PRIMARY_MAP];
/* An entry in the auxiliary primary map. base must be a 64k-aligned
value, and sm points at the relevant secondary map. As with the
main primary map, the secondary may be either a real secondary, or
one of the three distinguished secondaries. DO NOT CHANGE THIS
LAYOUT: the first word has to be the key for OSet fast lookups.
*/
typedef
struct {
Addr base;
SecMap* sm;
}
AuxMapEnt;
/* Tunable parameter: How big is the L1 queue? */
#define N_AUXMAP_L1 24
/* Tunable parameter: How far along the L1 queue to insert
entries resulting from L2 lookups? */
#define AUXMAP_L1_INSERT_IX 12
static struct {
Addr base;
AuxMapEnt* ent; // pointer to the matching auxmap_L2 node
}
auxmap_L1[N_AUXMAP_L1];
static OSet* auxmap_L2 = NULL;
static void init_auxmap_L1_L2 ( void )
{
Int i;
for (i = 0; i < N_AUXMAP_L1; i++) {
auxmap_L1[i].base = 0;
auxmap_L1[i].ent = NULL;
}
tl_assert(0 == offsetof(AuxMapEnt,base));
tl_assert(sizeof(Addr) == sizeof(void*));
auxmap_L2 = VG_(OSetGen_Create)( /*keyOff*/ offsetof(AuxMapEnt,base),
/*fastCmp*/ NULL,
VG_(malloc), "mc.iaLL.1", VG_(free) );
}
/* Check representation invariants; if OK return NULL; else a
descriptive bit of text. Also return the number of
non-distinguished secondary maps referred to from the auxiliary
primary maps. */
//static HChar* check_auxmap_L1_L2_sanity ( Word* n_secmaps_found )
//{
// Word i, j;
/* On a 32-bit platform, the L2 and L1 tables should
both remain empty forever.
On a 64-bit platform:
In the L2 table:
all .base & 0xFFFF == 0
all .base > MAX_PRIMARY_ADDRESS
In the L1 table:
all .base & 0xFFFF == 0
all (.base > MAX_PRIMARY_ADDRESS
.base & 0xFFFF == 0
and .ent points to an AuxMapEnt with the same .base)
or
(.base == 0 and .ent == NULL)
*/
// *n_secmaps_found = 0;
// if (sizeof(void*) == 4) {
/* 32-bit platform */
// if (VG_(OSetGen_Size)(auxmap_L2) != 0)
// return "32-bit: auxmap_L2 is non-empty";
// for (i = 0; i < N_AUXMAP_L1; i++)
// if (auxmap_L1[i].base != 0 || auxmap_L1[i].ent != NULL)
// return "32-bit: auxmap_L1 is non-empty";
// } else {
/* 64-bit platform */
// UWord elems_seen = 0;
// AuxMapEnt *elem, *res;
// AuxMapEnt key;
/* L2 table */
// VG_(OSetGen_ResetIter)(auxmap_L2);
// while ( (elem = VG_(OSetGen_Next)(auxmap_L2)) ) {
// elems_seen++;
// if (0 != (elem->base & (Addr)0xFFFF))
// return "64-bit: nonzero .base & 0xFFFF in auxmap_L2";
// if (elem->base <= MAX_PRIMARY_ADDRESS)
// return "64-bit: .base <= MAX_PRIMARY_ADDRESS in auxmap_L2";
// if (elem->sm == NULL)
// return "64-bit: .sm in _L2 is NULL";
// if (!is_distinguished_sm(elem->sm))
// (*n_secmaps_found)++;
// }
// if (elems_seen != n_auxmap_L2_nodes)
// return "64-bit: disagreement on number of elems in _L2";
/* Check L1-L2 correspondence */
/* for (i = 0; i < N_AUXMAP_L1; i++) {
if (auxmap_L1[i].base == 0 && auxmap_L1[i].ent == NULL)
continue;
if (0 != (auxmap_L1[i].base & (Addr)0xFFFF))
return "64-bit: nonzero .base & 0xFFFF in auxmap_L1";
if (auxmap_L1[i].base <= MAX_PRIMARY_ADDRESS)
return "64-bit: .base <= MAX_PRIMARY_ADDRESS in auxmap_L1";
if (auxmap_L1[i].ent == NULL)
return "64-bit: .ent is NULL in auxmap_L1";
if (auxmap_L1[i].ent->base != auxmap_L1[i].base)
return "64-bit: _L1 and _L2 bases are inconsistent";*/
/* Look it up in auxmap_L2. */
/* key.base = auxmap_L1[i].base;
key.sm = 0;
res = VG_(OSetGen_Lookup)(auxmap_L2, &key);
if (res == NULL)
return "64-bit: _L1 .base not found in _L2";
if (res != auxmap_L1[i].ent)
return "64-bit: _L1 .ent disagrees with _L2 entry";
}*/
/* Check L1 contains no duplicates */
/* for (i = 0; i < N_AUXMAP_L1; i++) {
if (auxmap_L1[i].base == 0)
continue;
for (j = i+1; j < N_AUXMAP_L1; j++) {
if (auxmap_L1[j].base == 0)
continue;
if (auxmap_L1[j].base == auxmap_L1[i].base)
return "64-bit: duplicate _L1 .base entries";
}
}
}
return NULL;*/ /* ok */
//}
static void insert_into_auxmap_L1_at ( Word rank, AuxMapEnt* ent )
{
Word i;
tl_assert(ent);
tl_assert(rank >= 0 && rank < N_AUXMAP_L1);
for (i = N_AUXMAP_L1-1; i > rank; i--)
auxmap_L1[i] = auxmap_L1[i-1];
auxmap_L1[rank].base = ent->base;
auxmap_L1[rank].ent = ent;
}
static INLINE AuxMapEnt* maybe_find_in_auxmap ( Addr a )
{
AuxMapEnt key;
AuxMapEnt* res;
Word i;
tl_assert(a > MAX_PRIMARY_ADDRESS);
a &= ~(Addr)0xFFFF;
/* First search the front-cache, which is a self-organising
list containing the most popular entries. */
if (LIKELY(auxmap_L1[0].base == a))
return auxmap_L1[0].ent;
if (LIKELY(auxmap_L1[1].base == a)) {
Addr t_base = auxmap_L1[0].base;
AuxMapEnt* t_ent = auxmap_L1[0].ent;
auxmap_L1[0].base = auxmap_L1[1].base;
auxmap_L1[0].ent = auxmap_L1[1].ent;
auxmap_L1[1].base = t_base;
auxmap_L1[1].ent = t_ent;
return auxmap_L1[0].ent;
}
n_auxmap_L1_searches++;
for (i = 0; i < N_AUXMAP_L1; i++) {
if (auxmap_L1[i].base == a) {
break;
}
}
tl_assert(i >= 0 && i <= N_AUXMAP_L1);
n_auxmap_L1_cmps += (ULong)(i+1);
if (i < N_AUXMAP_L1) {
if (i > 0) {
Addr t_base = auxmap_L1[i-1].base;
AuxMapEnt* t_ent = auxmap_L1[i-1].ent;
auxmap_L1[i-1].base = auxmap_L1[i-0].base;
auxmap_L1[i-1].ent = auxmap_L1[i-0].ent;
auxmap_L1[i-0].base = t_base;
auxmap_L1[i-0].ent = t_ent;
i--;
}
return auxmap_L1[i].ent;
}
n_auxmap_L2_searches++;
/* First see if we already have it. */
key.base = a;
key.sm = 0;
res = VG_(OSetGen_Lookup)(auxmap_L2, &key);
if (res)
insert_into_auxmap_L1_at( AUXMAP_L1_INSERT_IX, res );
return res;
}
static AuxMapEnt* find_or_alloc_in_auxmap ( Addr a )
{
AuxMapEnt *nyu, *res;
/* First see if we already have it. */
res = maybe_find_in_auxmap( a );
if (LIKELY(res))
return res;
/* Ok, there's no entry in the secondary map, so we'll have
to allocate one. */
a &= ~(Addr)0xFFFF;
nyu = (AuxMapEnt*) VG_(OSetGen_AllocNode)( auxmap_L2, sizeof(AuxMapEnt) );
tl_assert(nyu);
nyu->base = a;
nyu->sm = &sm_distinguished[SM_DIST_NOACCESS];
VG_(OSetGen_Insert)( auxmap_L2, nyu );
insert_into_auxmap_L1_at( AUXMAP_L1_INSERT_IX, nyu );
n_auxmap_L2_nodes++;
return nyu;
}
/* --------------- SecMap fundamentals --------------- */ //586
// In all these, 'low' means it's definitely in the main primary map,
// 'high' means it's definitely in the auxiliary table.
static INLINE SecMap** get_secmap_low_ptr ( Addr a )
{
UWord pm_off = a >> 16;
//# if VG_DEBUG_MEMORY >= 1
tl_assert(pm_off < N_PRIMARY_MAP);
//# endif
return &primary_map[ pm_off ];
}
static INLINE SecMap** get_secmap_high_ptr ( Addr a )
{
AuxMapEnt* am = find_or_alloc_in_auxmap(a);
return &am->sm;
}
static SecMap** get_secmap_ptr ( Addr a )
{
return ( a <= MAX_PRIMARY_ADDRESS
? get_secmap_low_ptr(a)
: get_secmap_high_ptr(a));
}
static INLINE SecMap* get_secmap_for_reading_low ( Addr a )
{
return *get_secmap_low_ptr(a);
}
static INLINE SecMap* get_secmap_for_reading_high ( Addr a )
{
return *get_secmap_high_ptr(a);
}
static INLINE SecMap* get_secmap_for_writing_low(Addr a)
{
SecMap** p = get_secmap_low_ptr(a);
if (UNLIKELY(is_distinguished_sm(*p)))
*p = copy_for_writing(*p);
return *p;
}
static INLINE SecMap* get_secmap_for_writing_high ( Addr a )
{
SecMap** p = get_secmap_high_ptr(a);
if (UNLIKELY(is_distinguished_sm(*p)))
*p = copy_for_writing(*p);
return *p;
}
/* Produce the secmap for 'a', either from the primary map or by
ensuring there is an entry for it in the aux primary map. The
secmap may be a distinguished one as the caller will only want to
be able to read it.
*/
static INLINE SecMap* get_secmap_for_reading ( Addr a )
{
return ( a <= MAX_PRIMARY_ADDRESS
? get_secmap_for_reading_low (a)
: get_secmap_for_reading_high(a) );
}
/* Produce the secmap for 'a', either from the primary map or by
ensuring there is an entry for it in the aux primary map. The
secmap may not be a distinguished one, since the caller will want
to be able to write it. If it is a distinguished secondary, make a
writable copy of it, install it, and return the copy instead. (COW
semantics).
*/
static SecMap* get_secmap_for_writing ( Addr a )
{
return ( a <= MAX_PRIMARY_ADDRESS
? get_secmap_for_writing_low (a)
: get_secmap_for_writing_high(a) );
}
/* If 'a' has a SecMap, produce it. Else produce NULL. But don't
allocate one if one doesn't already exist. This is used by the
leak checker.
*/
/*static SecMap* maybe_get_secmap_for ( Addr a )
{
if (a <= MAX_PRIMARY_ADDRESS) {
return get_secmap_for_reading_low(a);
} else {
AuxMapEnt* am = maybe_find_in_auxmap(a);
return am ? am->sm : NULL;
}
}*/
/* --------------- Fundamental functions --------------- */
static INLINE
void insert_vabits2_into_vabits8 ( Addr a, UChar vabits2, UChar* vabits8 ) //682
{
UInt shift = (a & 3) << 1; // shift by 0, 2, 4, or 6
*vabits8 &= ~(0x3 << shift); // mask out the two old bits
*vabits8 |= (vabits2 << shift); // mask in the two new bits
}
static INLINE
void insert_vabits4_into_vabits8 ( Addr a, UChar vabits4, UChar* vabits8 )
{
UInt shift;
tl_assert(VG_IS_2_ALIGNED(a)); // Must be 2-aligned
shift = (a & 2) << 1; // shift by 0 or 4
*vabits8 &= ~(0xf << shift); // mask out the four old bits
*vabits8 |= (vabits4 << shift); // mask in the four new bits
}
static INLINE
UChar extract_vabits2_from_vabits8 ( Addr a, UChar vabits8 )
{
UInt shift = (a & 3) << 1; // shift by 0, 2, 4, or 6
vabits8 >>= shift; // shift the two bits to the bottom
return 0x3 & vabits8; // mask out the rest
}
static INLINE
UChar extract_vabits4_from_vabits8 ( Addr a, UChar vabits8 )
{
UInt shift;
tl_assert(VG_IS_2_ALIGNED(a)); // Must be 2-aligned
shift = (a & 2) << 1; // shift by 0 or 4
vabits8 >>= shift; // shift the four bits to the bottom
return 0xf & vabits8; // mask out the rest
}
// Note that these four are only used in slow cases. The fast cases do
// clever things like combine the auxmap check (in
// get_secmap_{read,writ}able) with alignment checks.
// *** WARNING! ***
// Any time this function is called, if it is possible that vabits2
// is equal to VA_BITS2_PARTUNTAINTED, then the corresponding entry in the
// sec-V-bits table must also be set!
static INLINE
void set_vabits2 ( Addr a, UChar vabits2 ) //726
{
SecMap* sm = get_secmap_for_writing(a); // Taintgrind: only handle 32-bits
UWord sm_off = SM_OFF(a);
#ifdef DBG_MEM
// Taintgrind
// if (vabits2 == VA_BITS2_TAINTED)
VG_(printf)("set_vabits2 a:0x%08lx vabits2:0x%x sm->vabit8[sm_off]:0x%08x\n",
a, vabits2, (Int)&(sm->vabits8[sm_off]));
#endif
insert_vabits2_into_vabits8( a, vabits2, &(sm->vabits8[sm_off]) );
}
// Needed by TNT_(instrument)
//static INLINE
UChar get_vabits2 ( Addr a )
{
SecMap* sm = get_secmap_for_reading(a); // Taintgrind: only handle 32-bits
UWord sm_off = SM_OFF(a);
UChar vabits8 = sm->vabits8[sm_off];
#ifdef DBG_MEM
// Taintgrind
UChar result = extract_vabits2_from_vabits8(a, vabits8);
// if (vabits2 == VA_BITS2_TAINTED)
VG_(printf)("get_vabits2 a:0x%08lx vabits2:0x%x sm->vabit8[sm_off]:0x%08x\n",
a, result, (Int)&vabits8);
return result;
#endif
return extract_vabits2_from_vabits8(a, vabits8);
}
// *** WARNING! ***
// Any time this function is called, if it is possible that any of the
// 4 2-bit fields in vabits8 are equal to VA_BITS2_PARTUNTAINTED, then the
// corresponding entry(s) in the sec-V-bits table must also be set!
static INLINE
UChar get_vabits8_for_aligned_word32 ( Addr a ) //747
{
SecMap* sm = get_secmap_for_reading(a);
UWord sm_off = SM_OFF(a);
UChar vabits8 = sm->vabits8[sm_off];
return vabits8;
}
static INLINE
void set_vabits8_for_aligned_word32 ( Addr a, UChar vabits8 )
{
SecMap* sm = get_secmap_for_writing(a);
UWord sm_off = SM_OFF(a);
sm->vabits8[sm_off] = vabits8;
}
// Forward declarations
static UWord get_sec_vbits8(Addr a);
static void set_sec_vbits8(Addr a, UWord vbits8);
// Returns False if there was an addressability error.
static INLINE
Bool set_vbits8 ( Addr a, UChar vbits8 ) //768
{
Bool ok = True;
UChar vabits2 = get_vabits2(a);
if ( VA_BITS2_NOACCESS != vabits2 ) {
// Addressable. Convert in-register format to in-memory format.
// Also remove any existing sec V bit entry for the byte if no
// longer necessary.
if ( V_BITS8_UNTAINTED == vbits8 ) { vabits2 = VA_BITS2_UNTAINTED; }
else if ( V_BITS8_TAINTED == vbits8 ) { vabits2 = VA_BITS2_TAINTED; }
else { vabits2 = VA_BITS2_PARTUNTAINTED;
set_sec_vbits8(a, vbits8); }
set_vabits2(a, vabits2);
} else {
// Unaddressable! Do nothing -- when writing to unaddressable
// memory it acts as a black hole, and the V bits can never be seen
// again. So we don't have to write them at all.
ok = False;
}
return ok;
}
// Returns False if there was an addressability error. In that case, we put
// all defined bits into vbits8.
static INLINE
Bool get_vbits8 ( Addr a, UChar* vbits8 )
{
Bool ok = True;
UChar vabits2 = get_vabits2(a);
// Convert the in-memory format to in-register format.
if ( VA_BITS2_UNTAINTED == vabits2 ) { *vbits8 = V_BITS8_UNTAINTED; }
else if ( VA_BITS2_TAINTED == vabits2 ) { *vbits8 = V_BITS8_TAINTED; }
else if ( VA_BITS2_NOACCESS == vabits2 ) {
*vbits8 = V_BITS8_UNTAINTED; // Make V bits defined!
ok = False;
} else {
tl_assert( VA_BITS2_PARTUNTAINTED == vabits2 );
*vbits8 = get_sec_vbits8(a);
}
return ok;
}
/* --------------- Secondary V bit table ------------ */ //815
static OSet* secVBitTable;
// Stats
static ULong sec_vbits_new_nodes = 0;
static ULong sec_vbits_updates = 0;
// This must be a power of two; this is checked in tnt_pre_clo_init().
// The size chosen here is a trade-off: if the nodes are bigger (ie. cover
// a larger address range) they take more space but we can get multiple
// partially-defined bytes in one if they are close to each other, reducing
// the number of total nodes. In practice sometimes they are clustered (eg.
// perf/bz2 repeatedly writes then reads more than 20,000 in a contiguous
// row), but often not. So we choose something intermediate.
#define BYTES_PER_SEC_VBIT_NODE 16
// We make the table bigger if more than this many nodes survive a GC.
#define MAX_SURVIVOR_PROPORTION 0.5
// Each time we make the table bigger, we increase it by this much.
#define TABLE_GROWTH_FACTOR 2
// This defines "sufficiently stale" -- any node that hasn't been touched in
// this many GCs will be removed.
#define MAX_STALE_AGE 2
// We GC the table when it gets this many nodes in it, ie. it's effectively
// the table size. It can change.
static Int secVBitLimit = 1024;
// The number of GCs done, used to age sec-V-bit nodes for eviction.
// Because it's unsigned, wrapping doesn't matter -- the right answer will
// come out anyway.
static UInt GCs_done = 0;
typedef
struct {
Addr a;
UChar vbits8[BYTES_PER_SEC_VBIT_NODE];
UInt last_touched;
}
SecVBitNode;
static OSet* createSecVBitTable(void)
{
return VG_(OSetGen_Create)( offsetof(SecVBitNode, a),
NULL, // use fast comparisons
VG_(malloc), "mc.cSVT.1 (sec VBit table)",
VG_(free) );
}
static void gcSecVBitTable(void)
{
OSet* secVBitTable2;
SecVBitNode* n;
Int i, n_nodes = 0, n_survivors = 0;
GCs_done++;
// Create the new table.
secVBitTable2 = createSecVBitTable();
// Traverse the table, moving fresh nodes into the new table.
VG_(OSetGen_ResetIter)(secVBitTable);
while ( (n = VG_(OSetGen_Next)(secVBitTable)) ) {
Bool keep = False;
if ( (GCs_done - n->last_touched) <= MAX_STALE_AGE ) {
// Keep node if it's been touched recently enough (regardless of
// freshness/staleness).
keep = True;
} else {
// Keep node if any of its bytes are non-stale. Using
// get_vabits2() for the lookup is not very efficient, but I don't
// think it matters.
for (i = 0; i < BYTES_PER_SEC_VBIT_NODE; i++) {
if (VA_BITS2_PARTUNTAINTED == get_vabits2(n->a + i)) {
keep = True; // Found a non-stale byte, so keep
break;
}
}
}
if ( keep ) {
// Insert a copy of the node into the new table.
SecVBitNode* n2 =
VG_(OSetGen_AllocNode)(secVBitTable2, sizeof(SecVBitNode));
*n2 = *n;
VG_(OSetGen_Insert)(secVBitTable2, n2);
}
}
// Get the before and after sizes.
n_nodes = VG_(OSetGen_Size)(secVBitTable);
n_survivors = VG_(OSetGen_Size)(secVBitTable2);
// Destroy the old table, and put the new one in its place.
VG_(OSetGen_Destroy)(secVBitTable);
secVBitTable = secVBitTable2;
if (VG_(clo_verbosity) > 1) {
HChar percbuf[6];
VG_(percentify)(n_survivors, n_nodes, 1, 6, percbuf);
VG_(message)(Vg_DebugMsg, "tnt_main.c: GC: %d nodes, %d survivors (%s)\n",
n_nodes, n_survivors, percbuf);
}
// Increase table size if necessary.
if (n_survivors > (secVBitLimit * MAX_SURVIVOR_PROPORTION)) {
secVBitLimit *= TABLE_GROWTH_FACTOR;
if (VG_(clo_verbosity) > 1)
VG_(message)(Vg_DebugMsg, "tnt_main.c: GC: increase table size to %d\n",
secVBitLimit);
}
}
static UWord get_sec_vbits8(Addr a) //962
{
Addr aAligned = VG_ROUNDDN(a, BYTES_PER_SEC_VBIT_NODE);
Int amod = a % BYTES_PER_SEC_VBIT_NODE;
SecVBitNode* n = VG_(OSetGen_Lookup)(secVBitTable, &aAligned);
UChar vbits8;
tl_assert2(n, "get_sec_vbits8: no node for address %p (%p)\n", aAligned, a);
// Shouldn't be fully defined or fully undefined -- those cases shouldn't
// make it to the secondary V bits table.
vbits8 = n->vbits8[amod];
tl_assert(V_BITS8_UNTAINTED != vbits8 && V_BITS8_TAINTED != vbits8);
return vbits8;
}
static void set_sec_vbits8(Addr a, UWord vbits8)
{
Addr aAligned = VG_ROUNDDN(a, BYTES_PER_SEC_VBIT_NODE);
Int i, amod = a % BYTES_PER_SEC_VBIT_NODE;
SecVBitNode* n = VG_(OSetGen_Lookup)(secVBitTable, &aAligned);
// Shouldn't be fully defined or fully undefined -- those cases shouldn't
// make it to the secondary V bits table.
tl_assert(V_BITS8_UNTAINTED != vbits8 && V_BITS8_TAINTED != vbits8);
if (n) {
n->vbits8[amod] = vbits8; // update
n->last_touched = GCs_done;
sec_vbits_updates++;
} else {
// New node: assign the specific byte, make the rest invalid (they
// should never be read as-is, but be cautious).
n = VG_(OSetGen_AllocNode)(secVBitTable, sizeof(SecVBitNode));
n->a = aAligned;
for (i = 0; i < BYTES_PER_SEC_VBIT_NODE; i++) {
n->vbits8[i] = V_BITS8_TAINTED;
}
n->vbits8[amod] = vbits8;
n->last_touched = GCs_done;
// Do a table GC if necessary. Nb: do this before inserting the new
// node, to avoid erroneously GC'ing the new node.
if (secVBitLimit == VG_(OSetGen_Size)(secVBitTable)) {
gcSecVBitTable();
}
// Insert the new node.
VG_(OSetGen_Insert)(secVBitTable, n);
sec_vbits_new_nodes++;
n_secVBit_nodes = VG_(OSetGen_Size)(secVBitTable);
if (n_secVBit_nodes > max_secVBit_nodes)
max_secVBit_nodes = n_secVBit_nodes;
}
}
/* --------------- Endianness helpers --------------- */
/* Returns the offset in memory of the byteno-th most significant byte
in a wordszB-sized word, given the specified endianness. */
static INLINE UWord byte_offset_w ( UWord wordszB, Bool bigendian, //1019
UWord byteno ) {
return bigendian ? (wordszB-1-byteno) : byteno;
}
/* --------------- Load/store slow cases. --------------- *///1147
static
#ifndef PERF_FAST_LOADV
INLINE
#endif
ULong tnt_LOADVn_slow ( Addr a, SizeT nBits, Bool bigendian )
{
/* Make up a 64-bit result V word, which contains the loaded data for
valid addresses and Defined for invalid addresses. Iterate over
the bytes in the word, from the most significant down to the
least. */
ULong vbits64 = V_BITS64_TAINTED;
SizeT szB = nBits / 8;
SSizeT i; // Must be signed.
SizeT n_addrs_bad = 0;
Addr ai;
Bool partial_load_exemption_applies;
UChar vbits8;
Bool ok;
PROF_EVENT(30, "tnt_LOADVn_slow");
/* ------------ BEGIN semi-fast cases ------------ */
/* These deal quickly-ish with the common auxiliary primary map
cases on 64-bit platforms. Are merely a speedup hack; can be
omitted without loss of correctness/functionality. Note that in
both cases the "sizeof(void*) == 8" causes these cases to be
folded out by compilers on 32-bit platforms. These are derived
from LOADV64 and LOADV32.
*/
if (LIKELY(sizeof(void*) == 8
&& nBits == 64 && VG_IS_8_ALIGNED(a))) {
SecMap* sm = get_secmap_for_reading(a);
UWord sm_off16 = SM_OFF_16(a);
UWord vabits16 = ((UShort*)(sm->vabits8))[sm_off16];
if (LIKELY(vabits16 == VA_BITS16_UNTAINTED))
return V_BITS64_UNTAINTED;
if (LIKELY(vabits16 == VA_BITS16_TAINTED))
return V_BITS64_TAINTED;
/* else fall into the slow case */
}
if (LIKELY(sizeof(void*) == 8
&& nBits == 32 && VG_IS_4_ALIGNED(a))) {
SecMap* sm = get_secmap_for_reading(a);
UWord sm_off = SM_OFF(a);
UWord vabits8 = sm->vabits8[sm_off];
if (LIKELY(vabits8 == VA_BITS8_UNTAINTED))
return ((UWord)0xFFFFFFFF00000000ULL | (UWord)V_BITS32_UNTAINTED);
if (LIKELY(vabits8 == VA_BITS8_TAINTED))
return ((UWord)0xFFFFFFFF00000000ULL | (UWord)V_BITS32_TAINTED);
/* else fall into slow case */
}
/* ------------ END semi-fast cases ------------ */
tl_assert(nBits == 64 || nBits == 32 || nBits == 16 || nBits == 8);
for (i = szB-1; i >= 0; i--) {
PROF_EVENT(31, "tnt_LOADVn_slow(loop)");
ai = a + byte_offset_w(szB, bigendian, i);
ok = get_vbits8(ai, &vbits8);
if (!ok) n_addrs_bad++;
vbits64 <<= 8;
vbits64 |= vbits8;
}
/* This is a hack which avoids producing errors for code which
insists in stepping along byte strings in aligned word-sized
chunks, and there is a partially defined word at the end. (eg,
optimised strlen). Such code is basically broken at least WRT
semantics of ANSI C, but sometimes users don't have the option
to fix it, and so this option is provided. Note it is now
defaulted to not-engaged.
A load from a partially-addressible place is allowed if:
- the command-line flag is set
- it's a word-sized, word-aligned load
- at least one of the addresses in the word *is* valid
*/
partial_load_exemption_applies
= /*TNT_(clo_partial_loads_ok)*/ 0 && szB == VG_WORDSIZE
&& VG_IS_WORD_ALIGNED(a)
&& n_addrs_bad < VG_WORDSIZE;
// Taintgrind: TODO
// if (n_addrs_bad > 0 && !partial_load_exemption_applies)
// TNT_(record_address_error)( VG_(get_running_tid)(), a, szB, False );
#ifdef DBG_LOAD
if( nBits == 8 &&
vbits64
// || (a & 0x80000000)
)
VG_(printf)("tnt_LOADn_slow 0x%08lx 0x%llx\n", a, vbits64);
// VG_(printf)("tnt_LOADn_slow 0x%08lx\n", a);
#endif
return vbits64;
}
static
#ifndef PERF_FAST_STOREV
INLINE
#endif
void tnt_STOREVn_slow ( Addr a, SizeT nBits, ULong vbytes, Bool bigendian )
{
SizeT szB = nBits / 8;
SizeT i, n_addrs_bad = 0;
UChar vbits8;
Addr ai;
Bool ok;
PROF_EVENT(35, "tnt_STOREVn_slow");
/* ------------ BEGIN semi-fast cases ------------ */