Re: [PATCH 1/2] x86/cfi: Fix ret_from_fork indirect calls

[Peter Zijlstra]

On Wed, Jun 21, 2023 at 08:33:56PM +0200, Peter Zijlstra wrote:
> On Wed, Jun 21, 2023 at 08:16:59PM +0200, Peter Zijlstra wrote:
> > On Wed, Jun 21, 2023 at 11:08:46AM -0700, Kees Cook wrote:
> > 
> > > Ah yeah, it should be direct-called only. I keep forgetting about the
> > > endbr removal pass.
> > > 
> > > > I can't seem to manage to have it clobber it's __cfi hash value. Ideally
> > > > we'd have an attribute to force the thing to 0 or something.
> > > 
> > > Doesn't objtool have logic to figure out this is only ever
> > > direct-called?
> > 
> > It does; let me also use that same thing to clobber the kCFI hashes for
> > these functions.
> 
> Completely untested... gotta go put the kids to bed. I'll try later.

With a few minor edits it seems to actually boot too. I'll go write up a
Changelog tomorrow. Now I've got to discover how Drizzt's adventure
continues ;-)