On Tue, 2023-11-07 at 14:08 -0800, Ben Greear wrote: > Hello, > > I think this lockup is because iw is holding rtnl and wiphy mutex, > and is blocked waiting for debugfs to be closed. Another 'cat' > program has debugfs file open, and is blocking on trying to acquire > wiphy mutex. > > I think we must not acquire wiphy mutex in debugfs methods, somehow, > to resolve this deadlock. I do not know a safe way to do that. Hmm. I almost want to say "don't do that then", but I guess you're just randomly accessing debugfs files. I guess we can at least make the mutex acquisition in debugfs killable (or interruptible), so you can recover from this. But fundamentally this is probably not really even a new issue. I don't know how to interrupt a specific task that's stuck in a specific debugfs file though, e.g. when removing them. johannes
