Re: [PATCH v7 03/14] x86/cet/ibt: Add IBT legacy code bitmap setup function

[Yu-cheng Yu]

On Fri, 2019-06-07 at 15:27 -0700, Andy Lutomirski wrote:
> > On Jun 7, 2019, at 2:09 PM, Dave Hansen <dave.hansen@xxxxxxxxx> wrote:
> > 
> > On 6/7/19 1:06 PM, Yu-cheng Yu wrote:
> > > > Huh, how does glibc know about all possible past and future legacy code
> > > > in the application?
> > > 
> > > When dlopen() gets a legacy binary and the policy allows that, it will
> > > manage
> > > the bitmap:
> > > 
> > >  If a bitmap has not been created, create one.
> > >  Set bits for the legacy code being loaded.
> > 
> > I was thinking about code that doesn't go through GLIBC like JITs.
> 
> CRIU is another consideration: it would be rather annoying if CET programs
> canât migrate between LA57 and normal machines.

When a machine migrates, does its applications' addresses change?
If no, then the bitmap should still work, right?

Yu-cheng