On 18.09.18 18:15:51, Will Deacon wrote: > On Tue, Sep 18, 2018 at 11:52:27AM +0200, Robert Richter wrote: > > On 18.09.18 09:38:05, Will Deacon wrote: > > > On Mon, Sep 17, 2018 at 07:22:07PM +0200, Robert Richter wrote: > > > > On 27.08.18 16:33:07, Mian Yousaf Kaukab wrote: > > > > > Hard-coded since patches are merged and there are no configuration > > > > > options. > > > > > > > > Could you add a list of upstream patches to the description that are > > > > required to solve this? This would be a strict definition for the > > > > mitigation being enabled and makes it easier to check if backports are > > > > affected or not. A build-time check would be ideal (e.g. checking for > > > > certain macros). > > > > > > Hmm, I don't grok what you're proposing here. Why do we need a build-time > > > check (and to check what?) > > > > My concern is, that for kernel backports (esp. distro kernels) there > > could be various interpretations of what "Mitigation: __user pointer > > sanitization" means. So a list of upstream patches that need to be > > backported in addition to this patch as a requirement would be good to > > agree on. That should be documented in the patch description. > > > > If these mitigations are available in a kernel backport, that could be > > even checked at build time. E.g. we could have a sanity check if the > > macro array_index_nospec() is defined. But such a check does not > > replace a code review of a kernel backport. > > > > I hope that makes sense? > > Ok, I see what you mean now, thanks. However, it doesn't sound much > different than backporting a patch with dependencies, so I'd rather > avoid adding additional code to treat this case specially.
A pointer to the patches would be helpful as the dependencies are not obvious. This is different to just backport a complete series of patches. -Robert
