| // 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 | |
| // 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") | |
| } | |
| if runtime.GOOS == "netbsd" && runtime.GOARCH == "arm" { | |
| t.Skip("netbsd-arm doesn't provide fault address (golang.org/issue/45026)") | |
| } | |
| 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 | |
| } | |