Re: [RFC PATCH 06/11] x86: make sure _etext includes function sections

Arvind Sankar
2020-02-10T16:36:33Z

On Mon, Feb 10, 2020 at 07:54:58AM -0800, Arjan van de Ven wrote:
> >
> > I'll leave it to others to figure out the exact details. But afaict it
> > should be possible to have fine-grained-randomization and preserve the
> > workaround in the end.
> >
>
> the most obvious "solution" is to compile with an alignment of 4 bytes (so tight packing)
> and then in the randomizer preserve the offset within 32 bytes, no matter what it is
>
> that would get you an average padding of 16 bytes which is a bit more than now but not too insane
> (queue Kees' argument that tiny bits of padding are actually good)
>

With the patchset for adding the mbranches-within-32B-boundaries option,
the section alignment gets forced to 32. With function-sections that
means function alignment has to be 32 too.