* Andy Lutomirski <l...@kernel.org> wrote: > On Tue, May 9, 2017 at 1:56 AM, Christoph Hellwig <h...@infradead.org> wrote: > > On Tue, May 09, 2017 at 08:45:22AM +0200, Ingo Molnar wrote: > >> We only have ~115 code blocks in the kernel that set/restore KERNEL_DS, it > >> would > >> be a pity to add a runtime check to every system call ... > > > > I think we should simply strive to remove all of them that aren't > > in core scheduler / arch code. Basically evetyytime we do the > > > > oldfs = get_fs(); > > set_fs(KERNEL_DS); > > .. > > set_fs(oldfs); > > > > trick we're doing something wrong, and there should always be better > > ways to archive it. E.g. using iov_iter with a ITER_KVEC type > > consistently would already remove most of them. > > How about trying to remove all of them? If we could actually get rid > of all of them, we could drop the arch support, and we'd get faster, > simpler, shorter uaccess code throughout the kernel.
I'm all for that! Thanks, Ingo