25.02.2020, 10:08, "Jonathan de Boyne Pollard" <j.deboynepollard-newsgro...@ntlworld.com>: >> Of course, but once the fd is closed, /dev/console should not have >> any impact on the process, so would a kbrequest still reach it? > > Yes. First: This is a kernel virtual terminal thing not a console > thing. Strictly speaking, it is doing it wrongly to access it through > the console device, which is not necessarily a KVT. Second: The > mechanism does not require an open file descriptor. It requires that > the target process never terminate, because there's no symmetrical > kernel API function to disable the mechanism once it has been enabled, > but it does not require that that process have any particular file > descriptors open.
so /dev/tty0 should be open(2)ed instead of /dev/console since it is the tty master. and again: will the by the ioctl(2) call achieved arrangement survive exec chaining into another binary (the stage2 executable s6-svscan in case of s6) ?
