* postmaster: > The pipe works fine and the process can correctly transmit data back to the > master. The only issue appears when trying to run input pump based > applications like cat, grep, etc. When running these applications the pipe > write end which is marked FC_CLOEXEC should be closed when execve is > triggered, however it is not, but execve still succeeded. > When the target process to execve is not an input pump (uname, ls, .) no > issue occurs and the pipe is correctly closed when execve is triggered and > succeeds. > > That is a problem as my master process expects the blocking read to return > with either cause of pipe file descriptor closed or some data written. In > this case when the target process is an input pump the master process never > gets notified of file descriptor closed and by extension locks forever. Do you have a minimal but complete example that shows the problem? You cannot really make standard input a CLOEXEC descriptor. If you do not want subprocesses to use the original standard input, you need to replace the descriptor with /dev/null before the execve call (but already in the subprocess).
