executor, table: fix potential data race (pingcap#55737) (pingcap#55739)

close pingcap#43118

Author: ti-chi-bot

executor/mem_reader.go

@@ -801,11 +801,7 @@ func getColIDAndPkColIDs(ctx sessionctx.Context, tbl table.Table, columns []*mod
 		pkColIDs = []int64{-1}
 	}
 	defVal := func(i int) ([]byte, error) {
-		sessVars := ctx.GetSessionVars()
-		originStrict := sessVars.StrictSQLMode
-		sessVars.StrictSQLMode = false
-		d, err := table.GetColOriginDefaultValue(ctx, columns[i])
-		sessVars.StrictSQLMode = originStrict
+		d, err := table.GetColOriginDefaultValueWithoutStrictSQLMode(ctx, columns[i])
 		if err != nil {
 			return nil, err
 		}

table/tables/tables.go

@@ -2266,16 +2266,12 @@ func SetPBColumnsDefaultValue(ctx sessionctx.Context, pbColumns []*tipb.ColumnIn
 			continue
 		}
 
-		sessVars := ctx.GetSessionVars()
-		originStrict := sessVars.StrictSQLMode
-		sessVars.StrictSQLMode = false
-		d, err := table.GetColOriginDefaultValue(ctx, c)
-		sessVars.StrictSQLMode = originStrict
+		d, err := table.GetColOriginDefaultValueWithoutStrictSQLMode(ctx, c)
 		if err != nil {
 			return err
 		}
 
-		pbColumns[i].DefaultVal, err = tablecodec.EncodeValue(sessVars.StmtCtx, nil, d)
+		pbColumns[i].DefaultVal, err = tablecodec.EncodeValue(ctx.GetSessionVars().StmtCtx, nil, d)
 		if err != nil {
 			return err
 		}