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authorOndřej Surý <ondrej@sury.org>2011-09-13 13:13:40 +0200
committerOndřej Surý <ondrej@sury.org>2011-09-13 13:13:40 +0200
commit5ff4c17907d5b19510a62e08fd8d3b11e62b431d (patch)
treec0650497e988f47be9c6f2324fa692a52dea82e1 /test/nilptr/structfield.go
parent80f18fc933cf3f3e829c5455a1023d69f7b86e52 (diff)
downloadgolang-upstream/60.tar.gz
Imported Upstream version 60upstream/60
Diffstat (limited to 'test/nilptr/structfield.go')
-rw-r--r--test/nilptr/structfield.go34
1 files changed, 34 insertions, 0 deletions
diff --git a/test/nilptr/structfield.go b/test/nilptr/structfield.go
new file mode 100644
index 000000000..35196bb68
--- /dev/null
+++ b/test/nilptr/structfield.go
@@ -0,0 +1,34 @@
+// $G $D/$F.go && $L $F.$A &&
+// ((! sh -c ./$A.out) >/dev/null 2>&1 || echo BUG: should fail)
+
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import "unsafe"
+
+var dummy [512<<20]byte // give us a big address space
+type T struct {
+ x [256<<20] byte
+ i int
+}
+
+func main() {
+ // the test only tests what we intend to test
+ // if dummy starts in the first 256 MB of memory.
+ // otherwise there might not be anything mapped
+ // at the address that might be accidentally
+ // dereferenced below.
+ if uintptr(unsafe.Pointer(&dummy)) > 256<<20 {
+ panic("dummy too far out")
+ }
+
+ // The problem here is that indexing into t with a large
+ // enough index can jump out of the unmapped section
+ // at the beginning of memory and into valid memory.
+ // We require the pointer dereference to check.
+ var t *T
+ println(t.i) // should crash
+}