Adding upstream version 1.21.8.upstream/1.21.8

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 58 insertions, 0 deletions

diff --git a/test/fixedbugs/issue26407.go b/test/fixedbugs/issue26407.go
new file mode 100644
index 0000000..aa8e79c
--- /dev/null
+++ b/test/fixedbugs/issue26407.go
@@ -0,0 +1,58 @@
+// run
+
+// Copyright 2018 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.
+
+// Issue 26407: ensure that stack variables which have
+// had their address taken and then used in a comparison,
+// but are otherwise unused, are cleared.
+
+package main
+
+func main() {
+	poison()
+	test()
+}
+
+//go:noinline
+func poison() {
+	// initialise the stack with invalid pointers
+	var large [256]uintptr
+	for i := range large {
+		large[i] = 1
+	}
+	use(large[:])
+}
+
+//go:noinline
+func test() {
+	a := 2
+	x := &a
+	if x != compare(&x) {
+		panic("not possible")
+	}
+}
+
+//go:noinline
+func compare(x **int) *int {
+	var y *int
+	if x == &y {
+		panic("not possible")
+	}
+	// grow the stack to trigger a check for invalid pointers
+	grow()
+	if x == &y {
+		panic("not possible")
+	}
+	return *x
+}
+
+//go:noinline
+func grow() {
+	var large [1 << 16]uintptr
+	use(large[:])
+}
+
+//go:noinline
+func use(_ []uintptr) { }