On Tue, Sep 01, 2020 at 11:57:37AM -0700, Kees Cook wrote: > On Sat, Aug 29, 2020 at 11:24:06AM +0200, Christoph Hellwig wrote: > > On Thu, Aug 27, 2020 at 11:06:28AM -0700, Linus Torvalds wrote: > > > On Thu, Aug 27, 2020 at 8:00 AM Christoph Hellwig <hch@xxxxxx> wrote: > > > > > > > > Once we can't manipulate the address limit, we also can't test what > > > > happens when the manipulation is abused. > > > > > > Just remove these tests entirely. > > > > > > Once set_fs() doesn't exist on x86, the tests no longer make any sense > > > what-so-ever, because test coverage will be basically zero. > > > > > > So don't make the code uglier just to maintain a fiction that > > > something is tested when it isn't really. > > > > Sure fine with me unless Kees screams. > > To clarify: if any of x86, arm64, arm, powerpc, riscv, and s390 are > using set_fs(), I want to keep this test. "ugly" is fine in lkdtm. :) And Linus wants them gone entirely, so I'll need a stage fight between the two of you. At least for this merge window I'm only planning on x86 and power, plus maybe riscv if I get the work done in time. Although helper from the maintainers would be welcome. s390 has a driver that still uses set_fs that will need some surgery, although it shouldn't be too bad, but arm will be a piece of work. Unless I get help it will take a while.