cgo and fatal: morestack on g0

[Miha Vrhovnik]

Hey,

we are using a library via CGO that is the emulator for a real device.

That library also contains a javascript engine which calls to Go for communication to the outside world. The problem we are facing is that we are getting more and more crashes with "morestack on g0".

I have found tickets on the go github (for windows) that show that this occurs where go is out of stack. When looking at the gdb bt, the callstack doesn't seem so deep.

And before anyone asks, yes the call stack looks like this  go->c->c->.........->c->go (crash).

The main is locked to the Os thread with runtime.LockOSThread() however removing this doesn't help.

Is there any chance of upping up the available stack in CGO cases.

The behavior is the same on 1.16.7 and newly released 1.17.

BR,

Miha

[Ian Lance Taylor]

You didn't mention what kind of system you are using. When a Go
program uses cgo, the C threads will be created with the default stack
size for that system. Many systems have a way to configure this value
independently of the program. For example, on Linux, use ulimit -s.

Ian