On Wed, Oct 28, 2020 at 11:56 PM Kees Cook <keescook@xxxxxxxxxxxx> wrote: > On Mon, Oct 26, 2020 at 11:31:01AM +0100, Jann Horn wrote: > > Or I guess we could also just set O_NONBLOCK on the fd by default? > > Since the one existing user is eventloop-based... > > I thought about that initially, but it rubs me the wrong way: it > violates least-surprise for me. File descriptors are expected to be > default-blocking. It *is* a special fd, though, so maybe it could work. > The only case I can think of it would break would be ioctl-loop case > that is already buggy in that it didn't handle non-zero returns? We don't have any actual users that use the API that way outside of the kernel's selftest/sample code, right?