Re: [PATCH v7 03/14] x86/cet/ibt: Add IBT legacy code bitmap setup function
From: Yu-cheng Yu
Date: Mon Jun 10 2019 - 12:17:45 EST
On Fri, 2019-06-07 at 14:09 -0700, Dave Hansen 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.
If JIT manages the bitmap, it knows where it is.
It can always read the bitmap again, right?