On Wed, Jul 24, 2024 at 11:07:32AM +0300, stsp wrote: > 24.07.2024 09:51, Greg KH пишет: > > What caused this change/regression? > > I have absolutely no idea. > I've found it by debugging userspace, > and wrote a test-case to make sure the > problem is not in user-space. So this has always worked this way? Or has it changed? If changed, when did it work before? > > And does any real-world programs > > rely on this? > > dosemu It does this today or wants to do this in the future? > > What exactly are you trying to determine with this ioctl > > test? > > Whether it is a PTS (Pseudo-Tty-Slave), or > a real comport with MSR signalling. Why is that needed? And why not do it how other programs (like stty) does it? > > Is there a different way to determine that? > I am not aware of any "canonical" way > of determining this. Maybe you tell me. :) > So far the only fix I know, is to stop checking > errno. But you return ENOTTY for a tty-associated > fd (isatty(fd)==1), so I believe this is a > bug in a kernel. isatty() is a libc provided function, not a kernel call. thanks, greg k-h
