Fix MIPS build failure: Handle unaligned buffers in connect's TYPBLK classbb-10.5-connect-anel

On MIPS platforms (and probably others) unaligned memory access results in a
bus error. In the connect storage engine, block data for some data formats is
stored packed in memory and the TYPBLK class is used to read values from it.
Since TYPBLK does not have special handling for this packed memory, it can
quite easily result in unaligned memory accesses.

The simple way to fix this is to perform all accesses to the main buffer
through memcpy. With GCC and optimizations turned on, this call to memcpy is
completely optimized away on architectures where unaligned accesses are ok
(like x86).

Contributors:
James Cowgill <jcowgill@debian.org>

2 files changed, 52 insertions, 40 deletions

diff --git a/storage/connect/valblk.cpp b/storage/connect/valblk.cpp
index 2ae9382609d..9e63f49391d 100644
--- a/storage/connect/valblk.cpp
+++ b/storage/connect/valblk.cpp
@@ -268,14 +268,14 @@ bool TYPBLK<TYPE>::Init(PGLOBAL g, bool check)
 template <class TYPE>
 char *TYPBLK<TYPE>::GetCharString(char *p, int n)
   {
-  sprintf(p, Fmt, Typp[n]);
+  sprintf(p, Fmt, UnalignedRead(n));
   return p;
   } // end of GetCharString
 
 template <>
 char *TYPBLK<double>::GetCharString(char *p, int n)
   {
-  sprintf(p, Fmt, Prec, Typp[n]);
+  sprintf(p, Fmt, Prec, UnalignedRead(n));
   return p;
   } // end of GetCharString
 
@@ -291,7 +291,7 @@ void TYPBLK<TYPE>::SetValue(PVAL valp, int n)
   ChkTyp(valp);
 
   if (!(b = valp->IsNull()))
-    Typp[n] = GetTypedValue(valp);
+    UnalignedWrite(n, GetTypedValue(valp));
   else
     Reset(n);
 
@@ -353,9 +353,9 @@ void TYPBLK<TYPE>::SetValue(PCSZ p, int n)
   ulonglong val = CharToNumber(p, strlen(p), maxval, Unsigned, &minus); 
     
   if (minus && val < maxval)
-    Typp[n] = (TYPE)(-(signed)val);
+    UnalignedWrite(n, (TYPE)(-(signed)val));
   else
-    Typp[n] = (TYPE)val;
+    UnalignedWrite(n, (TYPE)val);
 
   SetNull(n, false);
   } // end of SetValue
@@ -398,7 +398,7 @@ void TYPBLK<double>::SetValue(PCSZ p, int n)
 		throw Type;
 	} // endif Check
 
-  Typp[n] = atof(p);
+  UnalignedWrite(n, atof(p));
   SetNull(n, false);
   } // end of SetValue
 
@@ -430,7 +430,7 @@ void TYPBLK<TYPE>::SetValue(PVBLK pv, int n1, int n2)
   ChkTyp(pv);
 
   if (!(b = pv->IsNull(n2) && Nullable))
-    Typp[n1] = GetTypedValue(pv, n2);
+    UnalignedWrite(n1, GetTypedValue(pv, n2));
   else
     Reset(n1);
 
@@ -481,10 +481,10 @@ void TYPBLK<TYPE>::SetMin(PVAL valp, int n)
   {
   CheckParms(valp, n)
   TYPE  tval = GetTypedValue(valp);
-  TYPE& tmin = Typp[n];
+  TYPE  tmin = UnalignedRead(n);
 
   if (tval < tmin)
-    tmin = tval;
+    UnalignedWrite(n, tval);
 
   } // end of SetMin
 
@@ -496,10 +496,10 @@ void TYPBLK<TYPE>::SetMax(PVAL valp, int n)
   {
   CheckParms(valp, n)
   TYPE  tval = GetTypedValue(valp);
-  TYPE& tmin = Typp[n];
+  TYPE  tmin = UnalignedRead(n);
 
   if (tval > tmin)
-    tmin = tval;
+    UnalignedWrite(n, tval);
 
   } // end of SetMax
 
@@ -513,8 +513,7 @@ void TYPBLK<TYPE>::SetValues(PVBLK pv, int k, int n)
   CheckType(pv)
   TYPE *lp = ((TYPBLK*)pv)->Typp;
 
-  for (int i = k; i < n; i++)          // TODO
-    Typp[i] = lp[i];
+  memcpy(Typp + k, lp + k, sizeof(TYPE) * n);
 
   } // end of SetValues
 #endif // 0
@@ -525,7 +524,7 @@ void TYPBLK<TYPE>::SetValues(PVBLK pv, int k, int n)
 template <class TYPE>
 void TYPBLK<TYPE>::Move(int i, int j)
   {
-  Typp[j] = Typp[i];
+  UnalignedWrite(j, UnalignedRead(i));
   MoveNull(i, j);
   } // end of Move
 
@@ -539,7 +538,7 @@ int TYPBLK<TYPE>::CompVal(PVAL vp, int n)
   ChkIndx(n);
   ChkTyp(vp);
 #endif   // _DEBUG
-  TYPE mlv = Typp[n];
+  TYPE mlv = UnalignedRead(n);
   TYPE vlv = GetTypedValue(vp);
 
   return (vlv > mlv) ? 1 : (vlv < mlv) ? (-1) : 0;
@@ -551,8 +550,8 @@ int TYPBLK<TYPE>::CompVal(PVAL vp, int n)
 template <class TYPE>
 int TYPBLK<TYPE>::CompVal(int i1, int i2)
   {
-  TYPE lv1 = Typp[i1];
-  TYPE lv2 = Typp[i2];
+  TYPE lv1 = UnalignedRead(i1);
+  TYPE lv2 = UnalignedRead(i2);
 
   return (lv1 > lv2) ? 1 : (lv1 < lv2) ? (-1) : 0;
   } // end of CompVal
@@ -589,7 +588,7 @@ int TYPBLK<TYPE>::Find(PVAL vp)
   TYPE n = GetTypedValue(vp);
 
   for (i = 0; i < Nval; i++)
-    if (n == Typp[i])
+    if (n == UnalignedRead(i))
       break;
 
   return (i < Nval) ? i : (-1);
@@ -605,7 +604,7 @@ int TYPBLK<TYPE>::GetMaxLength(void)
   int i, n, m;
 
   for (i = n = 0; i < Nval; i++) {
-    m = sprintf(buf, Fmt, Typp[i]);
+    m = sprintf(buf, Fmt, UnalignedRead(i));
     n = MY_MAX(n, m);
     } // endfor i
 
@@ -1335,7 +1334,7 @@ char *DATBLK::GetCharString(char *p, int n)
   char *vp;
 
   if (Dvalp) {
-    Dvalp->SetValue(Typp[n]);
+    Dvalp->SetValue(UnalignedRead(n));
     vp = Dvalp->GetCharString(p);
   } else
     vp = TYPBLK<int>::GetCharString(p, n);
@@ -1351,7 +1350,7 @@ void DATBLK::SetValue(PCSZ p, int n)
   if (Dvalp) {
     // Decode the string according to format
     Dvalp->SetValue_psz(p);
-    Typp[n] = Dvalp->GetIntValue();
+    UnalignedWrite(n, Dvalp->GetIntValue());
   } else
     TYPBLK<int>::SetValue(p, n);
 
diff --git a/storage/connect/valblk.h b/storage/connect/valblk.h
index ad970105868..39128686050 100644
--- a/storage/connect/valblk.h
+++ b/storage/connect/valblk.h
@@ -139,6 +139,7 @@ class VALBLK : public BLOCK {
   int     Prec;             // Precision of float values
   }; // end of class VALBLK
 
+
 /***********************************************************************/
 /*  Class TYPBLK: represents a block of typed values.                  */
 /***********************************************************************/
@@ -151,40 +152,41 @@ class TYPBLK : public VALBLK {
   // Implementation
   virtual bool   Init(PGLOBAL g, bool check);
   virtual int    GetVlen(void) {return sizeof(TYPE);}
-  virtual char   GetTinyValue(int n) {return (char)Typp[n];}
-  virtual uchar  GetUTinyValue(int n) {return (uchar)Typp[n];}
-  virtual short  GetShortValue(int n) {return (short)Typp[n];}
-  virtual ushort GetUShortValue(int n) {return (ushort)Typp[n];}
-  virtual int    GetIntValue(int n) {return (int)Typp[n];}
-  virtual uint   GetUIntValue(int n) {return (uint)Typp[n];}
-  virtual longlong GetBigintValue(int n) {return (longlong)Typp[n];}
-  virtual ulonglong GetUBigintValue(int n) {return (ulonglong)Typp[n];}
-  virtual double GetFloatValue(int n) {return (double)Typp[n];}
+
+  virtual char   GetTinyValue(int n) {return (char)UnalignedRead(n);}
+  virtual uchar  GetUTinyValue(int n) {return (uchar)UnalignedRead(n);}
+  virtual short  GetShortValue(int n) {return (short)UnalignedRead(n);}
+  virtual ushort GetUShortValue(int n) {return (ushort)UnalignedRead(n);}
+  virtual int    GetIntValue(int n) {return (int)UnalignedRead(n);}
+  virtual uint   GetUIntValue(int n) {return (uint)UnalignedRead(n);}
+  virtual longlong GetBigintValue(int n) {return (longlong)UnalignedRead(n);}
+  virtual ulonglong GetUBigintValue(int n) {return (ulonglong)UnalignedRead(n);}
+  virtual double GetFloatValue(int n) {return (double)UnalignedRead(n);}
   virtual char  *GetCharString(char *p, int n);
-  virtual void   Reset(int n) {Typp[n] = 0;}
+  virtual void   Reset(int n) {UnalignedWrite(n, 0);}
 
   // Methods
   using VALBLK::SetValue;
   virtual void   SetValue(PCSZ sp, int n);
   virtual void   SetValue(const char *sp, uint len, int n);
   virtual void   SetValue(short sval, int n)
-                  {Typp[n] = (TYPE)sval; SetNull(n, false);}
+                  {UnalignedWrite(n, (TYPE)sval); SetNull(n, false);}
   virtual void   SetValue(ushort sval, int n)
-                  {Typp[n] = (TYPE)sval; SetNull(n, false);}
+                  {UnalignedWrite(n, (TYPE)sval); SetNull(n, false);}
   virtual void   SetValue(int lval, int n)
-                  {Typp[n] = (TYPE)lval; SetNull(n, false);}
+                  {UnalignedWrite(n, (TYPE)lval); SetNull(n, false);}
   virtual void   SetValue(uint lval, int n)
-                  {Typp[n] = (TYPE)lval; SetNull(n, false);}
+                  {UnalignedWrite(n, (TYPE)lval); SetNull(n, false);}
   virtual void   SetValue(longlong lval, int n)
-                  {Typp[n] = (TYPE)lval; SetNull(n, false);}
+                  {UnalignedWrite(n, (TYPE)lval); SetNull(n, false);}
   virtual void   SetValue(ulonglong lval, int n)
-                  {Typp[n] = (TYPE)lval; SetNull(n, false);}
+                  {UnalignedWrite(n, (TYPE)lval); SetNull(n, false);}
   virtual void   SetValue(double fval, int n)
-                  {Typp[n] = (TYPE)fval; SetNull(n, false);}
+                  {UnalignedWrite(n, (TYPE)fval); SetNull(n, false);}
   virtual void   SetValue(char cval, int n)
-                  {Typp[n] = (TYPE)cval; SetNull(n, false);}
+                  {UnalignedWrite(n, (TYPE)cval); SetNull(n, false);}
   virtual void   SetValue(uchar cval, int n)
-                  {Typp[n] = (TYPE)cval; SetNull(n, false);}
+                  {UnalignedWrite(n, (TYPE)cval); SetNull(n, false);}
   virtual void   SetValue(PVAL valp, int n);
   virtual void   SetValue(PVBLK pv, int n1, int n2);
   virtual void   SetMin(PVAL valp, int n);
@@ -206,6 +208,17 @@ class TYPBLK : public VALBLK {
   // Members
   TYPE* const &Typp;
   const char  *Fmt;
+
+  // Unaligned access
+  TYPE UnalignedRead(int n) const {
+    TYPE result;
+    memcpy(&result, Typp + n, sizeof(TYPE));
+    return result;
+  }
+
+  void UnalignedWrite(int n, TYPE value) {
+    memcpy(Typp + n, &value, sizeof(TYPE));
+  }
   }; // end of class TYPBLK
 
 /***********************************************************************/