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-rw-r--r--test/fixedbugs/issue16515.go53
1 files changed, 53 insertions, 0 deletions
diff --git a/test/fixedbugs/issue16515.go b/test/fixedbugs/issue16515.go
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+++ b/test/fixedbugs/issue16515.go
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+// run
+
+// Copyright 2016 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 16515: spilled Duff-adjusted address may be invalid
+
+package main
+
+import "runtime"
+
+type T [62]int // DUFFZERO with non-zero adjustment on AMD64
+
+var sink interface{}
+
+//go:noinline
+func zero(x *T) {
+ // Two DUFFZEROs on the same address with a function call in between.
+ // Duff-adjusted address will be spilled and loaded
+
+ *x = T{} // DUFFZERO
+ runtime.GC()
+ (*x)[0] = 1
+ g() // call a function with large frame, trigger a stack move
+ *x = T{} // DUFFZERO again
+}
+
+//go:noinline
+// a function with large frame
+func g() {
+ var x [1000]int
+ _ = x
+}
+
+func main() {
+ var s struct { a T; b [8192-62]int } // allocate 64K, hopefully it's in a new span and a few bytes before it is garbage
+ sink = &s // force heap allocation
+ s.a[0] = 2
+ zero(&s.a)
+ if s.a[0] != 0 {
+ println("s.a[0] =", s.a[0])
+ panic("zeroing failed")
+ }
+
+ var a T // on stack
+ a[0] = 2
+ zero(&a)
+ if a[0] != 0 {
+ println("a[0] =", a[0])
+ panic("zeroing failed")
+ }
+}