linux-kernel - Re: [PATCH v3 3/7] x86/boot/compressed: Get rid of GOT fixup code

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <202006290852.8D8CAF38@keescook>
Date:   Mon, 29 Jun 2020 08:53:06 -0700
From:   Kees Cook <keescook@...omium.org>
To:     Arvind Sankar <nivedita@...m.mit.edu>
Cc:     Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
        "H. Peter Anvin" <hpa@...or.com>, x86@...nel.org,
        Nick Desaulniers <ndesaulniers@...gle.com>,
        Fangrui Song <maskray@...gle.com>,
        Dmitry Golovin <dima@...ovin.in>,
        clang-built-linux@...glegroups.com,
        Ard Biesheuvel <ardb@...nel.org>,
        Masahiro Yamada <masahiroy@...nel.org>,
        Daniel Kiper <daniel.kiper@...cle.com>,
        Sedat Dilek <sedat.dilek@...il.com>,
        Nathan Chancellor <natechancellor@...il.com>,
        Arnd Bergmann <arnd@...db.de>,
        "H . J . Lu" <hjl@...rceware.org>, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v3 3/7] x86/boot/compressed: Get rid of GOT fixup code

On Mon, Jun 29, 2020 at 10:09:24AM -0400, Arvind Sankar wrote:
> From: Ard Biesheuvel <ardb@...nel.org>
> 
> In a previous patch, we have eliminated GOT entries from the decompressor
> binary and added an assertion that the .got section is empty. This means
> that the GOT fixup routines that exist in both the 32-bit and 64-bit
> startup routines have become dead code, and can be removed.
> 
> While at it, drop the KEEP() from the linker script, as it has no effect
> on the contents of output sections that are created by the linker itself.
> 
> Signed-off-by: Ard Biesheuvel <ardb@...nel.org>
> Acked-by: Arvind Sankar <nivedita@...m.mit.edu>
> Signed-off-by: Arvind Sankar <nivedita@...m.mit.edu>
> From: Ard Biesheuvel <ardb@...nel.org>
> Link: https://lore.kernel.org/r/20200523120021.34996-4-ardb@kernel.org
> ---
>  arch/x86/boot/compressed/head_32.S     | 24 ++---------
>  arch/x86/boot/compressed/head_64.S     | 57 --------------------------
>  arch/x86/boot/compressed/vmlinux.lds.S |  4 +-
>  3 files changed, 5 insertions(+), 80 deletions(-)

This makes me very happy! This code always bugged me. ;)

Reviewed-by: Kees Cook <keescook@...omium.org>

-- 
Kees Cook