runtime: go of nil func value crashes #8045
Description
go version devel +4a839bf01b58 Tue May 20 15:52:08 2014 +1000 linux/amd64
The program is:
package main
func main() {
var f func()
go f()
select{}
}
Currently it crashes with:
fatal error: unexpected signal during runtime execution
[signal 0xb code=0x1 addr=0x0 pc=0x417e77]
goroutine 16 [running]:
runtime.throw(0x4561c5)
src/pkg/runtime/panic.c:520 +0x69 fp=0x7ff05514de78
runtime.sigpanic()
src/pkg/runtime/os_linux.c:222 +0x3d fp=0x7ff05514de90
runtime.gostartcallfn(0xc2080025c8, 0x0)
src/pkg/runtime/stack.c:847 +0x27 fp=0x7ff05514deb0
runtime.newproc1(0x0, 0x7ff05514df38, 0x0, 0x400c38)
src/pkg/runtime/proc.c:1852 +0x137 fp=0x7ff05514def0
runtime.newproc(0x0, 0x0)
src/pkg/runtime/proc.c:1803 +0x53 fp=0x7ff05514df28
main.main()
/tmp/go-build923308582/main.go:9 +0x38 fp=0x7ff05514df50
runtime.main()
src/pkg/runtime/proc.c:247 +0x11a fp=0x7ff05514dfa8
This happens because runtime.gostartcallfn dereferences nil with m->locks>0.
This causes unrecoverable fatal error. The program must panic instead.