mirror of
https://github.com/golang/go
synced 2024-11-22 21:40:03 -07:00
37 lines
955 B
Go
37 lines
955 B
Go
|
// $G $D/$F.go && $L $F.$A && (! ./$A.out || 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 f() *T {
|
||
|
|
return nil;
|
||
|
|
}
|
||
|
|
|
||
|
|
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.
|
||
|
|
println(f().i); // should crash
|
||
|
|
}
|