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:

quoted

On Thu, Aug 27, 2020 at 8:00 AM Christoph Hellwig [off-list ref] wrote:

quoted

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. :)

-- 
Kees Cook