Test that mmap size doesn't exceed system memory address width

Should fix http://paste.ubuntu.com/26074620/

diff --git a/storage/mmap.go b/storage/mmap.go
index 0dc512d431b8bab51e64917076951aac34e709a5..fbd3f54d0a6642530543115f1c6f6c4d0577570d 100644 (file)
--- a/storage/mmap.go
+++ b/storage/mmap.go
@@ -1,6 +1,7 @@
 package storage
 
 import (
+       "errors"
        "fmt"
        "io"
        "os"
@@ -142,15 +143,18 @@ func mmapFile(name string, size int64) (ret mmap.MMap, err error) {
                // Can't mmap() regions with length 0.
                return
        }
-       ret, err = mmap.MapRegion(file,
-               int(size), // Probably not great on <64 bit systems.
-               mmap.RDWR, 0, 0)
+       intLen := int(size)
+       if int64(intLen) != size {
+               err = errors.New("size too large for system")
+               return
+       }
+       ret, err = mmap.MapRegion(file, intLen, mmap.RDWR, 0, 0)
        if err != nil {
-               err = fmt.Errorf("mapping file %q, length %d: %s", file.Name(), size, err)
+               err = fmt.Errorf("error mapping region: %s", err)
                return
        }
        if int64(len(ret)) != size {
-               panic("mmap has wrong length")
+               panic(len(ret))
        }
        return
 }