fatal error: unexpected signal during runtime execution

[mappu]

Hi,

My go binary listens on a named pipe. All works fine normally, but I sometimes get this panic if the named pipe receives a connection:

fatal error: unexpected signal during runtime execution
[signal 0xc0000005 code=0x0 addr=0xffffffffffffffff pc=0x40f115]

goroutine 18 [running]:
runtime.throw(0xa53f6f, 0x2a)
	C:/Go/src/runtime/panic.go:596 +0x9c fp=0xc042151e08 sp=0xc042151de8
runtime.sigpanic()
	C:/Go/src/runtime/signal_windows.go:155 +0x18b fp=0xc042151e38 sp=0xc042151e08
runtime.lock(0x5105fcc3b06b83db)
	C:/Go/src/runtime/lock_sema.go:43 +0x65 fp=0xc042151e70 sp=0xc042151e38
runtime.chansend(0x970300, 0x5105fcc3b06b8383, 0xc042151fb0, 0xc042151f01, 0x5d013a, 0xc042151f9c)
	C:/Go/src/runtime/chan.go:176 +0xba fp=0xc042151f20 sp=0xc042151e70
runtime.chansend1(0x970300, 0x5105fcc3b06b8383, 0xc042151fb0)
	C:/Go/src/runtime/chan.go:113 +0x4d fp=0xc042151f60 sp=0xc042151f20
vendor/github.com/Microsoft/go-winio.ioCompletionProcessor(0x1f8)
	src/vendor/github.com/Microsoft/go-winio/file.go:133 +0xea fp=0xc042151fd8 sp=0xc042151f60
runtime.goexit()
	C:/Go/src/runtime/asm_amd64.s:2197 +0x1 fp=0xc042151fe0 sp=0xc042151fd8
created by vendor/github.com/Microsoft/go-winio.initIo
	src/vendor/github.com/Microsoft/go-winio/file.go:57 +0x87

Other google results for this error were submitted directly to golang/go, so i don't know if this is an issue with Golang's runtime or an issue with this library.

It seems to happen randomly, based on synchronisation state of other parts of the program.

go version go1.8 windows/amd64

EDIT: Simplified report using the latest information.

[mappu]

Hi,

I have a minimal test case that reproduces this issue in maybe 1 of 10 executions.

The program creates a named pipe to listen on; does some background work; and then connects to the named pipe.

It also involves one other third-party CGO library that seems to exacerbate the issue, but, this third-party library does not appear anywhere in the stack traces.

Source for reproducer:

• https://github.com/mappu/winio-zstd-panic/blob/master/src/winio-zstd-panic/main.go

Go-get installer:

• go get github.com/mappu/winio-zstd-panic/src/winio-zstd-panic

Example full stack trace:

• https://gist.github.com/mappu/d1972e6e59596e98c7d3b677b18e5237

[mappu]

After some research in ticket golang/go#19468 (comment) , i think this library has not been updated for the stricter runtime.SetFinalizer rules in Go 1.8. This is causing the library to use uninitialised memory.