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31 lines
1.0 KiB
Go
31 lines
1.0 KiB
Go
// $G $D/$F.go && $L $F.$A && (! ./$A.out || echo BUG: should fail)
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// Copyright 2009 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package main
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import "unsafe"
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var dummy [512<<20]byte; // give us a big address space
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func main() {
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// the test only tests what we intend to test
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// if dummy starts in the first 256 MB of memory.
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// otherwise there might not be anything mapped
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// at the address that might be accidentally
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// dereferenced below.
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if uintptr(unsafe.Pointer(&dummy)) > 256<<20 {
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panic("dummy too far out");
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}
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// The problem here is that indexing into p[] with a large
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// enough index jumps out of the unmapped section
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// at the beginning of memory and into valid memory.
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// Pointer offsets and array indices, if they are
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// very large, need to dereference the base pointer
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// to trigger a trap.
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var p *[1<<30]byte = nil;
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println(p[256<<20]); // very likely to be inside dummy, but should crash
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}
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