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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-16 19:23:18 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-16 19:23:18 +0000 |
commit | 43a123c1ae6613b3efeed291fa552ecd909d3acf (patch) | |
tree | fd92518b7024bc74031f78a1cf9e454b65e73665 /test/nilptr.go | |
parent | Initial commit. (diff) | |
download | golang-1.20-43a123c1ae6613b3efeed291fa552ecd909d3acf.tar.xz golang-1.20-43a123c1ae6613b3efeed291fa552ecd909d3acf.zip |
Adding upstream version 1.20.14.upstream/1.20.14upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'test/nilptr.go')
-rw-r--r-- | test/nilptr.go | 187 |
1 files changed, 187 insertions, 0 deletions
diff --git a/test/nilptr.go b/test/nilptr.go new file mode 100644 index 0000000..b296c88 --- /dev/null +++ b/test/nilptr.go @@ -0,0 +1,187 @@ +// run + +// Copyright 2011 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. + +// Test that the implementation catches nil ptr indirection +// in a large address space. + +// +build !aix +// +build !darwin !arm64 +// +build !windows !arm64 +// Address space starts at 1<<32 on AIX and on darwin/arm64 and on windows/arm64, so dummy is too far. + +package main + +import "unsafe" + +// Having a big address space means that indexing +// at a 256 MB offset from a nil pointer might not +// cause a memory access fault. This test checks +// that Go is doing the correct explicit checks to catch +// these nil pointer accesses, not just relying on the hardware. +var dummy [256 << 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") + } + + shouldPanic(p1) + shouldPanic(p2) + shouldPanic(p3) + shouldPanic(p4) + shouldPanic(p5) + shouldPanic(p6) + shouldPanic(p7) + shouldPanic(p8) + shouldPanic(p9) + shouldPanic(p10) + shouldPanic(p11) + shouldPanic(p12) + shouldPanic(p13) + shouldPanic(p14) + shouldPanic(p15) + shouldPanic(p16) +} + +func shouldPanic(f func()) { + defer func() { + if recover() == nil { + panic("memory reference did not panic") + } + }() + f() +} + +func p1() { + // Array index. + var p *[1 << 30]byte = nil + println(p[256<<20]) // very likely to be inside dummy, but should panic +} + +var xb byte + +func p2() { + var p *[1 << 30]byte = nil + xb = 123 + + // Array index. + println(p[uintptr(unsafe.Pointer(&xb))]) // should panic +} + +func p3() { + // Array to slice. + var p *[1 << 30]byte = nil + var x []byte = p[0:] // should panic + _ = x +} + +var q *[1 << 30]byte + +func p4() { + // Array to slice. + var x []byte + var y = &x + *y = q[0:] // should crash (uses arraytoslice runtime routine) +} + +func fb([]byte) { + panic("unreachable") +} + +func p5() { + // Array to slice. + var p *[1 << 30]byte = nil + fb(p[0:]) // should crash +} + +func p6() { + // Array to slice. + var p *[1 << 30]byte = nil + var _ []byte = p[10 : len(p)-10] // should crash +} + +type T struct { + x [256 << 20]byte + i int +} + +func f() *T { + return nil +} + +var y *T +var x = &y + +func p7() { + // Struct field access with large offset. + println(f().i) // should crash +} + +func p8() { + // Struct field access with large offset. + println((*x).i) // should crash +} + +func p9() { + // Struct field access with large offset. + var t *T + println(&t.i) // should crash +} + +func p10() { + // Struct field access with large offset. + var t *T + println(t.i) // should crash +} + +type T1 struct { + T +} + +type T2 struct { + *T1 +} + +func p11() { + t := &T2{} + p := &t.i + println(*p) +} + +// ADDR(DOT(IND(p))) needs a check also +func p12() { + var p *T = nil + println(*(&((*p).i))) +} + +// Tests suggested in golang.org/issue/6080. + +func p13() { + var x *[10]int + y := x[:] + _ = y +} + +func p14() { + println((*[1]int)(nil)[:]) +} + +func p15() { + for i := range (*[1]int)(nil)[:] { + _ = i + } +} + +func p16() { + for i, v := range (*[1]int)(nil)[:] { + _ = i + v + } +} |