golang badtraceback 代码
文件路径：/src/runtime/testdata/testprog/badtraceback.go
/ 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.
package main
import (
"runtime"
"runtime/debug"
"unsafe"
)
func init() {
register("BadTraceback", BadTraceback)
}
func BadTraceback() {
/ Disable GC to prevent traceback at unexpected time.
debug.SetGCPercent(-1)
/ Out of an abundance of caution, also make sure that there are
/ no GCs actively in progress.
runtime.GC()
/ Run badLR1 on its own stack to minimize the stack size and
/ exercise the stack bounds logic in the hex dump.
go badLR1()
select {}
}
/go:noinline
func badLR1() {
/ We need two frames on LR machines because we'll smash this
/ frame's saved LR.
badLR2(0)
}
/go:noinline
func badLR2(arg int) {
/ Smash the return PC or saved LR.
lrOff := unsafe.Sizeof(uintptr(0))
if runtime.GOARCH == "ppc64" || runtime.GOARCH == "ppc64le" {
lrOff = 32 / FIXED_FRAME or sys.MinFrameSize
}
lrPtr := (*uintptr)(unsafe.Pointer(uintptr(unsafe.Pointer(&arg)) - lrOff))
*lrPtr = 0xbad
/ Print a backtrace. This should include diagnostics for the
/ bad return PC and a hex dump.
panic("backtrace")
}