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Message-ID: <fc82a40dbc269bf1b4f9c9ca1b56e8115783edbb.camel@linux.intel.com>
Subject: Re: [RFC PATCH 08/11] x86: Add support for finer grained KASLR
From:   Kristen Carlson Accardi <kristen@linux.intel.com>
To:     Arvind Sankar <nivedita@alum.mit.edu>
Cc:     tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, hpa@zytor.com,
        arjan@linux.intel.com, keescook@chromium.org,
        rick.p.edgecombe@intel.com, x86@kernel.org,
        linux-kernel@vger.kernel.org, kernel-hardening@lists.openwall.com
Date:   Wed, 26 Feb 2020 11:26:08 -0800
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         <20200225174951.GA1373392@rani.riverdale.lan>
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On Tue, 2020-02-25 at 12:49 -0500, Arvind Sankar wrote:
> On Wed, Feb 05, 2020 at 02:39:47PM -0800, Kristen Carlson Accardi
> wrote:
> > At boot time, find all the function sections that have separate
> > .text
> > sections, shuffle them, and then copy them to new locations. Adjust
> > any relocations accordingly.
> > 
> > Signed-off-by: Kristen Carlson Accardi <kristen@linux.intel.com>
> > ---
> >  arch/x86/boot/compressed/Makefile        |   1 +
> >  arch/x86/boot/compressed/fgkaslr.c       | 751
> > +++++++++++++++++++++++
> >  arch/x86/boot/compressed/misc.c          | 106 +++-
> >  arch/x86/boot/compressed/misc.h          |  26 +
> >  arch/x86/boot/compressed/vmlinux.symbols |  15 +
> >  arch/x86/include/asm/boot.h              |  15 +-
> >  arch/x86/include/asm/kaslr.h             |   1 +
> >  arch/x86/lib/kaslr.c                     |  15 +
> >  scripts/kallsyms.c                       |  14 +-
> >  scripts/link-vmlinux.sh                  |   4 +
> >  10 files changed, 939 insertions(+), 9 deletions(-)
> >  create mode 100644 arch/x86/boot/compressed/fgkaslr.c
> >  create mode 100644 arch/x86/boot/compressed/vmlinux.symbols
> > 
> > diff --git a/arch/x86/boot/compressed/Makefile
> > b/arch/x86/boot/compressed/Makefile
> > index b7e5ea757ef4..60d4c4e59c05 100644
> > --- a/arch/x86/boot/compressed/Makefile
> > +++ b/arch/x86/boot/compressed/Makefile
> > @@ -122,6 +122,7 @@ OBJCOPYFLAGS_vmlinux.bin :=  -R .comment -S
> >  
> >  ifdef CONFIG_FG_KASLR
> >  	RELOCS_ARGS += --fg-kaslr
> > +	OBJCOPYFLAGS += --keep-symbols=$(obj)/vmlinux.symbols
> 
> I think this should be $(srctree)/$(src) rather than $(obj)? Using a
> separate build directory fails currently.

Thanks, I'll add this to my test plan for v1.