coregrind/pub_core_transtab.h

   1
   2 /*--------------------------------------------------------------------*/
   3 /*--- The translation table and cache.                             ---*/
   4 /*---                                          pub_core_transtab.h ---*/
   5 /*--------------------------------------------------------------------*/
   6
   7 /*
   8    This file is part of Valgrind, a dynamic binary instrumentation
   9    framework.
  10
  11    Copyright (C) 2000-2017 Julian Seward
  12       jseward@acm.org
  13
  14    This program is free software; you can redistribute it and/or
  15    modify it under the terms of the GNU General Public License as
  16    published by the Free Software Foundation; either version 2 of the
  17    License, or (at your option) any later version.
  18
  19    This program is distributed in the hope that it will be useful, but
  20    WITHOUT ANY WARRANTY; without even the implied warranty of
  21    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  22    General Public License for more details.
  23
  24    You should have received a copy of the GNU General Public License
  25    along with this program; if not, see <http://www.gnu.org/licenses/>.
  26
  27    The GNU General Public License is contained in the file COPYING.
  28 */
  29
  30 #ifndef __PUB_CORE_TRANSTAB_H
  31 #define __PUB_CORE_TRANSTAB_H
  32
  33 //--------------------------------------------------------------------
  34 // PURPOSE: This module is responsible for caching translations, and
  35 // enabling fast look-ups of them.
  36 //--------------------------------------------------------------------
  37
  38 #include "pub_core_transtab_asm.h"
  39 #include "pub_tool_transtab.h"
  40 #include "libvex.h"                   // VexGuestExtents
  41
  42 /* The fast-cache for tt-lookup.  Unused entries are denoted by
  43    .guest == TRANSTAB_BOGUS_GUEST_ADDR (viz, 1), which is assumed
  44    to be a bogus address for all guest code.  See pub_core_transtab_asm.h
  45    for further description. */
  46 typedef
  47    struct {
  48       Addr guest0;
  49       Addr host0;
  50       Addr guest1;
  51       Addr host1;
  52       Addr guest2;
  53       Addr host2;
  54       Addr guest3;
  55       Addr host3;
  56    }
  57    FastCacheSet;
  58
  59 STATIC_ASSERT(sizeof(Addr) == sizeof(UWord));
  60 STATIC_ASSERT(sizeof(FastCacheSet) == sizeof(Addr) * 8);
  61
  62 extern __attribute__((aligned(64)))
  63        FastCacheSet VG_(tt_fast) [VG_TT_FAST_SETS];
  64
  65 #define TRANSTAB_BOGUS_GUEST_ADDR ((Addr)1)
  66
  67 #if defined(VGA_x86) || defined(VGA_amd64)
  68 static inline UWord VG_TT_FAST_HASH ( Addr guest ) {
  69    // There's no minimum insn alignment on these targets.
  70    UWord merged = ((UWord)guest) >> 0;
  71    merged = (merged >> VG_TT_FAST_BITS) ^ merged;
  72    return merged & VG_TT_FAST_MASK;
  73 }
  74
  75 #elif defined(VGA_s390x) || defined(VGA_arm) || defined(VGA_nanomips)
  76 static inline UWord VG_TT_FAST_HASH ( Addr guest ) {
  77    // Instructions are 2-byte aligned.
  78    UWord merged = ((UWord)guest) >> 1;
  79    merged = (merged >> VG_TT_FAST_BITS) ^ merged;
  80    return merged & VG_TT_FAST_MASK;
  81 }
  82
  83 #elif defined(VGA_ppc32) || defined(VGA_ppc64be) || defined(VGA_ppc64le) \
  84       || defined(VGA_mips32) || defined(VGA_mips64) || defined(VGA_arm64)
  85 static inline UWord VG_TT_FAST_HASH ( Addr guest ) {
  86    // Instructions are 4-byte aligned.
  87    UWord merged = ((UWord)guest) >> 2;
  88    merged = (merged >> VG_TT_FAST_BITS) ^ merged;
  89    return merged & VG_TT_FAST_MASK;
  90 }
  91
  92 #else
  93 #  error "VG_TT_FAST_HASH: unknown platform"
  94 #endif
  95
  96 static inline Bool VG_(lookupInFastCache)( /*MB_OUT*/Addr* host, Addr guest )
  97 {
  98    UWord setNo = (UInt)VG_TT_FAST_HASH(guest);
  99    FastCacheSet* set = &VG_(tt_fast)[setNo];
 100    if (LIKELY(set->guest0 == guest)) {
 101       // hit at way 0
 102       *host = set->host0;
 103       return True;
 104    }
 105    if (LIKELY(set->guest1 == guest)) {
 106       // hit at way 1; swap upwards
 107       Addr tG = guest;
 108       Addr tH = set->host1;
 109       set->guest1 = set->guest0;
 110       set->host1  = set->host0;
 111       set->guest0 = tG;
 112       set->host0  = tH;
 113       *host = tH;
 114       return True;
 115    }
 116    if (LIKELY(set->guest2 == guest)) {
 117       // hit at way 2; swap upwards
 118       Addr tG = guest;
 119       Addr tH = set->host2;
 120       set->guest2 = set->guest1;
 121       set->host2  = set->host1;
 122       set->guest1 = tG;
 123       set->host1  = tH;
 124       *host = tH;
 125       return True;
 126    }
 127    if (LIKELY(set->guest3 == guest)) {
 128       // hit at way 3; swap upwards
 129       Addr tG = guest;
 130       Addr tH = set->host3;
 131       set->guest3 = set->guest2;
 132       set->host3  = set->host2;
 133       set->guest2 = tG;
 134       set->host2  = tH;
 135       *host = tH;
 136       return True;
 137    }
 138    // Not found
 139    *host = 0;
 140    return False;
 141 }
 142
 143
 144 /* Initialises the TC, using VG_(clo_num_transtab_sectors)
 145    and VG_(clo_avg_transtab_entry_size).
 146    VG_(clo_num_transtab_sectors) must be >= MIN_N_SECTORS
 147    and <= MAX_N_SECTORS. */
 148 extern void VG_(init_tt_tc)       ( void );
 149
 150
 151 /* Limits for number of sectors the TC is divided into.  If you need a larger
 152    overall translation cache, increase MAX_N_SECTORS. */
 153 #define MIN_N_SECTORS 2
 154 #define MAX_N_SECTORS 48
 155
 156 /* Default for the nr of sectors, if not overridden by command line.
 157    On Android, space is limited, so try to get by with fewer sectors.
 158    On other platforms we can go to town.  32 sectors gives theoretical
 159    capacity of about 880MB of JITted code in 2.1 million translations
 160    (realistically, about 2/3 of that) for Memcheck. */
 161 #if defined(VGPV_arm_linux_android) \
 162     || defined(VGPV_x86_linux_android) \
 163     || defined(VGPV_mips32_linux_android) \
 164     || defined(VGPV_arm64_linux_android)
 165 # define N_SECTORS_DEFAULT 12
 166 #else
 167 # define N_SECTORS_DEFAULT 32
 168 #endif
 169
 170 extern
 171 void VG_(add_to_transtab)( const VexGuestExtents* vge,
 172                            Addr             entry,
 173                            Addr             code,
 174                            UInt             code_len,
 175                            Bool             is_self_checking,
 176                            Int              offs_profInc,
 177                            UInt             n_guest_instrs );
 178
 179 typedef UShort SECno; // SECno type identifies a sector
 180 typedef UShort TTEno; // TTEno type identifies a TT entry in a sector.
 181
 182 // 2 constants that indicates Invalid entries.
 183 #define INV_SNO ((SECno)0xFFFF)
 184 #define INV_TTE ((TTEno)0xFFFF)
 185
 186 extern
 187 void VG_(tt_tc_do_chaining) ( void* from__patch_addr,
 188                               SECno to_sNo,
 189                               TTEno to_tteNo,
 190                               Bool  to_fastEP );
 191
 192 extern Bool VG_(search_transtab) ( /*OUT*/Addr*  res_hcode,
 193                                    /*OUT*/SECno* res_sNo,
 194                                    /*OUT*/TTEno* res_tteNo,
 195                                    Addr          guest_addr,
 196                                    Bool          upd_cache );
 197
 198 extern void VG_(discard_translations) ( Addr  start, ULong range,
 199                                         const HChar* who );
 200
 201 extern void VG_(print_tt_tc_stats) ( void );
 202
 203 extern ULong VG_(get_bbs_translated) ( void );
 204 extern ULong VG_(get_bbs_discarded_or_dumped) ( void );
 205
 206 /* Add to / search the auxiliary, small, unredirected translation
 207    table. */
 208
 209 extern
 210 void VG_(add_to_unredir_transtab)( const VexGuestExtents* vge,
 211                                    Addr             entry,
 212                                    Addr             code,
 213                                    UInt             code_len );
 214 extern
 215 Bool VG_(search_unredir_transtab) ( /*OUT*/Addr*  result,
 216                                     Addr          guest_addr );
 217
 218 // SB profiling stuff
 219
 220 typedef struct _SBProfEntry {
 221    Addr   addr;
 222    ULong  score;
 223 } SBProfEntry;
 224
 225 extern ULong VG_(get_SB_profile) ( SBProfEntry tops[], UInt n_tops );
 226
 227 //  Exported variables
 228 extern Bool  VG_(ok_to_discard_translations);
 229
 230 #endif   // __PUB_CORE_TRANSTAB_H
 231
 232 /*--------------------------------------------------------------------*/
 233 /*--- end                                                          ---*/
 234 /*--------------------------------------------------------------------*/