Why would (pseudocode, nonexisting but possible example) write(SIGKILL, "/proc/12345/signals") not be possible? For the other direction, there is signalfd in Linux. And of course you can get a peer address from /dev/tcp (https://andreafortuna.org/2021/03/06/some-useful-tips-about-... ). Yes, /dev/tcp is not an OS primitive but a bash builtin, but there isn't really a reason you cannot do this in the OS. Shared memory can be a file, you just have to mmap() it. mmap is always left out of the open/close/read/write-enumeration of the traditional file API, but I think it is actually extremely useful and should be the fifth alongside those.
Debugging is hard to imagine, yes. One could look at /proc/12345/mem, write breakpoints in there, but I'm not sure about how to do the more exotic things.
Debugging is hard to imagine, yes. One could look at /proc/12345/mem, write breakpoints in there, but I'm not sure about how to do the more exotic things.