// [ $GOOS != nacl ] || exit 0 # do not bother on NaCl // $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" func f([]byte) { panic("unreachable"); } var dummy [512<<20]byte; // give us a big address space 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 p[] with a large // enough index can jump out of the unmapped section // at the beginning of memory and into valid memory. // // To avoid needing a check on every slice beyond the // usual len and cap, we require the *array -> slice // conversion to do the check. var p *[1<<30]byte = nil; f(p[0:]); // should crash }