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go/test/fixedbugs/issue11656.go
Tom Thorogood 32e789f4fb test: fix incorrectly laid out instructions in issue11656.go
CL 279423 introduced a regression in this test as it incorrectly laid
out various instructions. In the case of arm, the second instruction
was overwriting the first. In the case of 386, amd64 and s390x, the
instructions were being appended to the end of the slice after 64
zero bytes.

This was causing test failures on "linux/s390x on z13".

Fixes #44028

Change-Id: Id136212dabdae27db7e91904b0df6a3a9d2f4af4
Reviewed-on: https://go-review.googlesource.com/c/go/+/288278
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
2021-02-01 21:38:01 +00:00

90 lines
2.4 KiB
Go

// run
// Copyright 2015 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.
// windows doesn't work, because Windows exception handling
// delivers signals based on the current PC, and that current PC
// doesn't go into the Go runtime.
// +build !windows
// wasm does not work, because the linear memory is not executable.
// +build !wasm
// This test doesn't work on gccgo/GoLLVM, because they will not find
// any unwind information for the artificial function, and will not be
// able to unwind past that point.
// +build !gccgo
package main
import (
"encoding/binary"
"runtime"
"runtime/debug"
"unsafe"
)
func main() {
debug.SetPanicOnFault(true)
defer func() {
if err := recover(); err == nil {
panic("not panicking")
}
pc, _, _, _ := runtime.Caller(10)
f := runtime.FuncForPC(pc)
if f == nil || f.Name() != "main.f" {
if f == nil {
println("no func for ", unsafe.Pointer(pc))
} else {
println("found func:", f.Name())
}
panic("cannot find main.f on stack")
}
}()
f(20)
}
func f(n int) {
if n > 0 {
f(n - 1)
}
var f struct {
x uintptr
}
// We want to force a seg fault, to get a crash at a PC value != 0.
// Not all systems make the data section non-executable.
ill := make([]byte, 64)
switch runtime.GOARCH {
case "386", "amd64":
ill = append(ill[:0], 0x89, 0x04, 0x25, 0x00, 0x00, 0x00, 0x00) // MOVL AX, 0
case "arm":
binary.LittleEndian.PutUint32(ill[0:4], 0xe3a00000) // MOVW $0, R0
binary.LittleEndian.PutUint32(ill[4:8], 0xe5800000) // MOVW R0, (R0)
case "arm64":
binary.LittleEndian.PutUint32(ill, 0xf90003ff) // MOVD ZR, (ZR)
case "ppc64":
binary.BigEndian.PutUint32(ill, 0xf8000000) // MOVD R0, (R0)
case "ppc64le":
binary.LittleEndian.PutUint32(ill, 0xf8000000) // MOVD R0, (R0)
case "mips", "mips64":
binary.BigEndian.PutUint32(ill, 0xfc000000) // MOVV R0, (R0)
case "mipsle", "mips64le":
binary.LittleEndian.PutUint32(ill, 0xfc000000) // MOVV R0, (R0)
case "s390x":
ill = append(ill[:0], 0xa7, 0x09, 0x00, 0x00) // MOVD $0, R0
ill = append(ill, 0xe3, 0x00, 0x00, 0x00, 0x00, 0x24) // MOVD R0, (R0)
case "riscv64":
binary.LittleEndian.PutUint32(ill, 0x00003023) // MOV X0, (X0)
default:
// Just leave it as 0 and hope for the best.
}
f.x = uintptr(unsafe.Pointer(&ill[0]))
p := &f
fn := *(*func())(unsafe.Pointer(&p))
fn()
}