blob: b93631e1d83b53e3215ebe754f0de38269e92482 [file] [log] [blame]
// Copyright 2020 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.
//go:build aix || darwin || dragonfly || freebsd || linux || netbsd || openbsd
// +build aix darwin dragonfly freebsd linux netbsd openbsd
// TODO: test on Windows?
package debug_test
import (
"runtime"
"runtime/debug"
"syscall"
"testing"
"unsafe"
)
func TestPanicOnFault(t *testing.T) {
if runtime.GOARCH == "s390x" {
t.Skip("s390x fault addresses are missing the low order bits")
}
if runtime.GOOS == "ios" {
t.Skip("iOS doesn't provide fault addresses")
}
m, err := syscall.Mmap(-1, 0, 0x1000, syscall.PROT_READ /* Note: no PROT_WRITE */, syscall.MAP_SHARED|syscall.MAP_ANON)
if err != nil {
t.Fatalf("can't map anonymous memory: %s", err)
}
defer syscall.Munmap(m)
old := debug.SetPanicOnFault(true)
defer debug.SetPanicOnFault(old)
const lowBits = 0x3e7
defer func() {
r := recover()
if r == nil {
t.Fatalf("write did not fault")
}
type addressable interface {
Addr() uintptr
}
a, ok := r.(addressable)
if !ok {
t.Fatalf("fault does not contain address")
}
want := uintptr(unsafe.Pointer(&m[lowBits]))
got := a.Addr()
if got != want {
t.Fatalf("fault address %x, want %x", got, want)
}
}()
m[lowBits] = 1 // will fault
}