Hi John, On Thu, Nov 11, 2021 at 09:39:06PM -0500, John Bazik wrote: > Package: src:linux > Version: 5.10.70-1 > Severity: normal > Tags: upstream > > Dear Maintainer, > > When reading from a pty, a call to read(2) always returns a string > ending in a newline, except when the text written to the pty > contains a multiple of 64 characters, plus the newline. In the > exceptional case, a second call to read returns just the newline. > > In the previous debian release, buster, with kernel 4.19.0-18-amd64, > a newline was always returned irrespective of the size of the input. > > This was discovered by students on our operating systems class. We > include a test program that exhibits the problem. The hardware > referenced in this ticket is a VM, but we saw similar results on > hardware.
I guess this should be upstream since the changes round 15ea8ae8e03f ("tty: teach n_tty line discipline about the new "cookie continuations"")[1], cf. [2]. [1] https://git.kernel.org/linus/15ea8ae8e03fdb845ed3ff5d9f11dd5f4f60252c [2] https://git.kernel.org/linux/3b830a9c34d5897be07176ce4e6f2d75e2c8cfd7 Regards, Salvatore