mirror of
https://github.com/golang/go
synced 2024-11-23 00:40:08 -07:00
bf5c0c957c
needs to dereference the base pointer to make sure it catches nil. R=r,ken DELTA=21 (21 added, 0 deleted, 0 changed) OCL=30083 CL=30101
26 lines
693 B
Go
26 lines
693 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 x byte
|
|
|
|
func main() {
|
|
var p *[1<<30]byte = nil;
|
|
x = 123;
|
|
|
|
// The problem here is not the use of unsafe:
|
|
// it is that indexing into p[] with a large
|
|
// enough index jumps out of the unmapped section
|
|
// at the beginning of memory and into valid memory.
|
|
// Pointer offsets and array indices, if they are
|
|
// very large, need to dereference the base pointer
|
|
// to trigger a trap.
|
|
println(p[uintptr(unsafe.Pointer(&x))]);
|
|
}
|