Esempio n. 1
0
IRStmt* pyvex_deepCopyIRStmt ( IRStmt* s )
{
   switch (s->tag) {
      case Ist_NoOp:
         return IRStmt_NoOp();
      case Ist_AbiHint:
         return IRStmt_AbiHint(pyvex_deepCopyIRExpr(s->Ist.AbiHint.base),
                               s->Ist.AbiHint.len,
                               pyvex_deepCopyIRExpr(s->Ist.AbiHint.nia));
      case Ist_IMark:
         return IRStmt_IMark(s->Ist.IMark.addr,
                             s->Ist.IMark.len,
                             s->Ist.IMark.delta);
      case Ist_Put: 
         return IRStmt_Put(s->Ist.Put.offset, 
                           pyvex_deepCopyIRExpr(s->Ist.Put.data));
      case Ist_PutI: 
         return IRStmt_PutI(pyvex_deepCopyIRPutI(s->Ist.PutI.details));
      case Ist_WrTmp:
         return IRStmt_WrTmp(s->Ist.WrTmp.tmp,
                             pyvex_deepCopyIRExpr(s->Ist.WrTmp.data));
      case Ist_Store: 
         return IRStmt_Store(s->Ist.Store.end,
                             pyvex_deepCopyIRExpr(s->Ist.Store.addr),
                             pyvex_deepCopyIRExpr(s->Ist.Store.data));
      case Ist_CAS:
         return IRStmt_CAS(pyvex_deepCopyIRCAS(s->Ist.CAS.details));
      case Ist_LLSC:
         return IRStmt_LLSC(s->Ist.LLSC.end,
                            s->Ist.LLSC.result,
                            pyvex_deepCopyIRExpr(s->Ist.LLSC.addr),
                            s->Ist.LLSC.storedata
                               ? pyvex_deepCopyIRExpr(s->Ist.LLSC.storedata)
                               : NULL);
      case Ist_Dirty: 
         return IRStmt_Dirty(pyvex_deepCopyIRDirty(s->Ist.Dirty.details));
      case Ist_MBE:
         return IRStmt_MBE(s->Ist.MBE.event);
      case Ist_Exit: 
         return IRStmt_Exit(pyvex_deepCopyIRExpr(s->Ist.Exit.guard),
                            s->Ist.Exit.jk,
                            pyvex_deepCopyIRConst(s->Ist.Exit.dst),
                            s->Ist.Exit.offsIP);
      default: 
         vpanic("pyvex_deepCopyIRStmt");
   }
}
Esempio n. 2
0
IRBB* bb_to_IR ( /*OUT*/VexGuestExtents* vge,
                 /*IN*/ void*            callback_opaque,
                 /*IN*/ DisOneInstrFn    dis_instr_fn,
                 /*IN*/ UChar*           guest_code,
                 /*IN*/ Addr64           guest_IP_bbstart,
                 /*IN*/ Bool             (*chase_into_ok)(void*,Addr64),
                 /*IN*/ Bool             host_bigendian,
                 /*IN*/ VexArch          arch_guest,
                 /*IN*/ VexArchInfo*     archinfo_guest,
                 /*IN*/ IRType           guest_word_type,
                 /*IN*/ Bool             do_self_check,
                 /*IN*/ Bool             (*preamble_function)(void*,IRBB*),
                 /*IN*/ Int              offB_TISTART,
                 /*IN*/ Int              offB_TILEN )
{
   Long       delta;
   Int        i, n_instrs, first_stmt_idx;
   Bool       resteerOK, need_to_put_IP, debug_print;
   DisResult  dres;
   IRStmt*    imark;
   static Int n_resteers = 0;
   Int        d_resteers = 0;
   Int        selfcheck_idx = 0;
   IRBB*      irbb;
   Addr64     guest_IP_curr_instr;
   IRConst*   guest_IP_bbstart_IRConst = NULL;

   Bool (*resteerOKfn)(void*,Addr64) = NULL;

   debug_print = toBool(vex_traceflags & VEX_TRACE_FE);

   /* Note: for adler32 to work without % operation for the self
      check, need to limit length of stuff it scans to 5552 bytes.
      Therefore limiting the max bb len to 100 insns seems generously
      conservative. */

   /* check sanity .. */
   vassert(sizeof(HWord) == sizeof(void*));
   vassert(vex_control.guest_max_insns >= 1);
   vassert(vex_control.guest_max_insns < 100);
   vassert(vex_control.guest_chase_thresh >= 0);
   vassert(vex_control.guest_chase_thresh < vex_control.guest_max_insns);
   vassert(guest_word_type == Ity_I32 || guest_word_type == Ity_I64);

   /* Start a new, empty extent. */
   vge->n_used  = 1;
   vge->base[0] = guest_IP_bbstart;
   vge->len[0]  = 0;

   /* And a new IR BB to dump the result into. */
   irbb = emptyIRBB();

   /* Delta keeps track of how far along the guest_code array we have
      so far gone. */
   delta    = 0;
   n_instrs = 0;

   /* Guest addresses as IRConsts.  Used in the two self-checks
      generated. */
   if (do_self_check) {
      guest_IP_bbstart_IRConst
         = guest_word_type==Ity_I32 
              ? IRConst_U32(toUInt(guest_IP_bbstart))
              : IRConst_U64(guest_IP_bbstart);
   }

   /* If asked to make a self-checking translation, leave 5 spaces
      in which to put the check statements.  We'll fill them in later
      when we know the length and adler32 of the area to check. */
   if (do_self_check) {
      selfcheck_idx = irbb->stmts_used;
      addStmtToIRBB( irbb, IRStmt_NoOp() );
      addStmtToIRBB( irbb, IRStmt_NoOp() );
      addStmtToIRBB( irbb, IRStmt_NoOp() );
      addStmtToIRBB( irbb, IRStmt_NoOp() );
      addStmtToIRBB( irbb, IRStmt_NoOp() );
   }

   /* If the caller supplied a function to add its own preamble, use
      it now. */
   if (preamble_function) {
      Bool stopNow = preamble_function( callback_opaque, irbb );
      if (stopNow) {
         /* The callback has completed the IR block without any guest
            insns being disassembled into it, so just return it at
            this point, even if a self-check was requested - as there
            is nothing to self-check.  The five self-check no-ops will
            still be in place, but they are harmless. */
         return irbb;
      }
   }

   /* Process instructions. */
   while (True) {
      vassert(n_instrs < vex_control.guest_max_insns);

      /* Regardless of what chase_into_ok says, is chasing permissible
         at all right now?  Set resteerOKfn accordingly. */
      resteerOK 
         = toBool(
              n_instrs < vex_control.guest_chase_thresh
              /* If making self-checking translations, don't chase
                 .. it makes the checks too complicated.  We only want
                 to scan just one sequence of bytes in the check, not
                 a whole bunch. */
              && !do_self_check
              /* we can't afford to have a resteer once we're on the
                 last extent slot. */
              && vge->n_used < 3
           );

      resteerOKfn
         = resteerOK ? chase_into_ok : const_False;

      /* This is the IP of the instruction we're just about to deal
         with. */
      guest_IP_curr_instr = guest_IP_bbstart + delta;

      /* This is the irbb statement array index of the first stmt in
         this insn.  That will always be the instruction-mark
         descriptor. */
      first_stmt_idx = irbb->stmts_used;

      /* Add an instruction-mark statement.  We won't know until after
         disassembling the instruction how long it instruction is, so
         just put in a zero length and we'll fix it up later. */
      addStmtToIRBB( irbb, IRStmt_IMark( guest_IP_curr_instr, 0 ));

      /* for the first insn, the dispatch loop will have set
         %IP, but for all the others we have to do it ourselves. */
      need_to_put_IP = toBool(n_instrs > 0);

      /* Finally, actually disassemble an instruction. */
      dres = dis_instr_fn ( irbb,
                            need_to_put_IP,
                            resteerOKfn,
                            callback_opaque,
                            guest_code,
                            delta,
                            guest_IP_curr_instr,
                            arch_guest,
                            archinfo_guest,
                            host_bigendian );

      /* stay sane ... */
      vassert(dres.whatNext == Dis_StopHere
              || dres.whatNext == Dis_Continue
              || dres.whatNext == Dis_Resteer);
      vassert(dres.len >= 0 && dres.len <= 20);
      if (dres.whatNext != Dis_Resteer)
         vassert(dres.continueAt == 0);

      /* Fill in the insn-mark length field. */
      vassert(first_stmt_idx >= 0 && first_stmt_idx < irbb->stmts_used);
      imark = irbb->stmts[first_stmt_idx];
      vassert(imark);
      vassert(imark->tag == Ist_IMark);
      vassert(imark->Ist.IMark.len == 0);
      imark->Ist.IMark.len = toUInt(dres.len);

      /* Print the resulting IR, if needed. */
      if (vex_traceflags & VEX_TRACE_FE) {
         for (i = first_stmt_idx; i < irbb->stmts_used; i++) {
            vex_printf("              ");
            ppIRStmt(irbb->stmts[i]);
            vex_printf("\n");
         }
      }

      /* If dis_instr_fn terminated the BB at this point, check it
	 also filled in the irbb->next field. */
      if (dres.whatNext == Dis_StopHere) {
         vassert(irbb->next != NULL);
         if (debug_print) {
            vex_printf("              ");
            vex_printf( "goto {");
            ppIRJumpKind(irbb->jumpkind);
            vex_printf( "} ");
            ppIRExpr( irbb->next );
            vex_printf( "\n");
         }
      }

      /* Update the VexGuestExtents we are constructing. */
      /* If vex_control.guest_max_insns is required to be < 100 and
	 each insn is at max 20 bytes long, this limit of 5000 then
	 seems reasonable since the max possible extent length will be
	 100 * 20 == 2000. */
      vassert(vge->len[vge->n_used-1] < 5000);
      vge->len[vge->n_used-1] 
         = toUShort(toUInt( vge->len[vge->n_used-1] + dres.len ));
      n_instrs++;
      if (debug_print) 
         vex_printf("\n");

      /* Advance delta (inconspicuous but very important :-) */
      delta += (Long)dres.len;

      switch (dres.whatNext) {
         case Dis_Continue:
            vassert(irbb->next == NULL);
            if (n_instrs < vex_control.guest_max_insns) {
               /* keep going */
            } else {
               /* We have to stop. */
               irbb->next 
                  = IRExpr_Const(
                       guest_word_type == Ity_I32
                          ? IRConst_U32(toUInt(guest_IP_bbstart+delta))
                          : IRConst_U64(guest_IP_bbstart+delta)
                    );
               goto done;
            }
            break;
         case Dis_StopHere:
            vassert(irbb->next != NULL);
            goto done;
         case Dis_Resteer:
            /* Check that we actually allowed a resteer .. */
            vassert(resteerOK);
            vassert(irbb->next == NULL);
            /* figure out a new delta to continue at. */
            vassert(resteerOKfn(callback_opaque,dres.continueAt));
            delta = dres.continueAt - guest_IP_bbstart;
            /* we now have to start a new extent slot. */
            vge->n_used++;
            vassert(vge->n_used <= 3);
            vge->base[vge->n_used-1] = dres.continueAt;
            vge->len[vge->n_used-1] = 0;
            n_resteers++;
            d_resteers++;
            if (0 && (n_resteers & 0xFF) == 0)
            vex_printf("resteer[%d,%d] to 0x%llx (delta = %lld)\n",
                       n_resteers, d_resteers,
                       dres.continueAt, delta);
            break;
         default:
            vpanic("bb_to_IR");
      }
   }
   /*NOTREACHED*/
   vassert(0);

  done:
   /* We're done.  The only thing that might need attending to is that
      a self-checking preamble may need to be created. */
   if (do_self_check) {

      UInt     len2check, adler32;
      IRTemp   tistart_tmp, tilen_tmp;

      vassert(vge->n_used == 1);
      len2check = vge->len[0];
      if (len2check == 0) 
         len2check = 1;

     adler32 = genericg_compute_adler32( (HWord)guest_code, len2check );

     /* Set TISTART and TILEN.  These will describe to the despatcher
        the area of guest code to invalidate should we exit with a
        self-check failure. */

     tistart_tmp = newIRTemp(irbb->tyenv, guest_word_type);
     tilen_tmp   = newIRTemp(irbb->tyenv, guest_word_type);

     irbb->stmts[selfcheck_idx+0]
        = IRStmt_Tmp(tistart_tmp, IRExpr_Const(guest_IP_bbstart_IRConst) );

     irbb->stmts[selfcheck_idx+1]
        = IRStmt_Tmp(tilen_tmp,
                     guest_word_type==Ity_I32 
                        ? IRExpr_Const(IRConst_U32(len2check)) 
                        : IRExpr_Const(IRConst_U64(len2check))
          );

     irbb->stmts[selfcheck_idx+2]
        = IRStmt_Put( offB_TISTART, IRExpr_Tmp(tistart_tmp) );

     irbb->stmts[selfcheck_idx+3]
        = IRStmt_Put( offB_TILEN, IRExpr_Tmp(tilen_tmp) );

     irbb->stmts[selfcheck_idx+4]
        = IRStmt_Exit( 
             IRExpr_Binop( 
                Iop_CmpNE32, 
                mkIRExprCCall( 
                   Ity_I32, 
                   2/*regparms*/, 
                   "genericg_compute_adler32",
#if defined(__powerpc__) && defined(__powerpc64__)
                   (void*)((ULong*)(&genericg_compute_adler32))[0],
#else
                   &genericg_compute_adler32,
#endif
                   mkIRExprVec_2( 
                      mkIRExpr_HWord( (HWord)guest_code ), 
                      mkIRExpr_HWord( (HWord)len2check )
                   )
                ),
                IRExpr_Const(IRConst_U32(adler32))
             ),
             Ijk_TInval,
             guest_IP_bbstart_IRConst
          );
   }

   return irbb;
}