Hi Greg, On Wed, Jun 12, 2024 at 04:21:25PM GMT, Greg KH wrote: > On Wed, Jun 12, 2024 at 04:00:18PM +0200, Alejandro Colomar wrote: > > I expect that these specific values and the operations done on them > > probably don't trigger UB, since the shifts are done by a controlled > > amount, and there are justa few operations done on them. > > These, for the most part, are NOT used as shifts. Quoting the EXAMPLES section in the manual page: tio.c_cflag &= ~(CBAUD << IBSHIFT); (And yeah, that shift is presumably controlled, so that it doesn't overflow, which is why I mean these are presumably just fine.) > > TL;DR: The kernel isn't broken, but improving this would allow users to > > enable stricter warnings, which is a good thing. > > Enable it where? I meant in user space programs that use termbits stuff. (That this may also allow the kernel to eventually have stricter warnings, I don't know. It might help. But mostly meant it for user space.) So, if I have a user-space program (or more likely a library) which wraps these ioctls, I'd prefer to be able to enable the warnings I reported, to preclude any mistakes in my code. That would need the constants to be unsigned, to avoid false negatives. Cheers, Alex -- <https://www.alejandro-colomar.es/>
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