On Sun, Sep 20, 2020 at 9:28 PM Andy Lutomirski <luto@xxxxxxxxxx> wrote: > On Sun, Sep 20, 2020 at 12:23 PM Matthew Wilcox <willy@xxxxxxxxxxxxx> wrote: > > > > On Sun, Sep 20, 2020 at 08:10:31PM +0100, Al Viro wrote: > > > IMO it's much saner to mark those and refuse to touch them from io_uring... > > > > Simpler solution is to remove io_uring from the 32-bit syscall list. > > If you're a 32-bit process, you don't get to use io_uring. Would > > any real users actually care about that? > > We could go one step farther and declare that we're done adding *any* > new compat syscalls :) Would you also stop adding system calls to native 32-bit systems then? On memory constrained systems (less than 2GB a.t.m.), there is still a strong demand for running 32-bit user space, but all of the recent Arm cores (after Cortex-A55) dropped the ability to run 32-bit kernels, so that compat mode may eventually become the primary way to run Linux on cheap embedded systems. I don't think there is any chance we can realistically take away io_uring from the 32-bit ABI any more now. Arnd