[vlc-devel] [PATCH] Win64: use high-entropy ASLR

[Jean-Baptiste Kempf]

On 23 May, Derek Buitenhuis wrote :
> On 5/23/2016 9:16 AM, Jean-Baptiste Kempf wrote:
> > ---
> >  configure.ac | 1 +
> >  1 file changed, 1 insertion(+)
> > 
> > diff --git a/configure.ac b/configure.ac
> > index 87d7c6b..326af67 100644
> > --- a/configure.ac
> > +++ b/configure.ac
> > @@ -269,6 +269,7 @@ case "${host_os}" in
> >                  HAVE_WIN64="1"
> >                  WINDOWS_ARCH="x64"
> >                  PROGRAMFILES="PROGRAMFILES64"
> > +                LDFLAGS="${LDFLAGS} -Wl,--high-entropy-va"
> 
> It may perhaps make sense to set the image base to >4GB, since this
> is Win64? e.g.:
> 
>     -Wl,--image-base,0x140000000
> 
> This is, in fact, what lld does by default, but not binutils (which
> has bad defaults all around). IIRC, the rationale is 'even more
> entropy when using HEASLR anyway'.

So, we should do both?

> Of course, I don't know if this will affect VLC somehow unexpectedly,
> but I can't imagine VLC has any code that would blow up.

It needs testing, but I don't see how it could explode, indeed.

-- 
Jean-Baptiste Kempf
http://www.jbkempf.com/ - +33 672 704 734
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