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[198.145.64.163]) by smtp.gmail.com with ESMTPSA id s6sm47034pjz.2.2020.06.29.08.53.07 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 29 Jun 2020 08:53:07 -0700 (PDT) Date: Mon, 29 Jun 2020 08:53:06 -0700 From: Kees Cook To: Arvind Sankar Cc: Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H. Peter Anvin" , x86@kernel.org, Nick Desaulniers , Fangrui Song , Dmitry Golovin , clang-built-linux@googlegroups.com, Ard Biesheuvel , Masahiro Yamada , Daniel Kiper , Sedat Dilek , Nathan Chancellor , Arnd Bergmann , "H . J . Lu" , linux-kernel@vger.kernel.org Subject: Re: [PATCH v3 3/7] x86/boot/compressed: Get rid of GOT fixup code Message-ID: <202006290852.8D8CAF38@keescook> References: <20200629140928.858507-1-nivedita@alum.mit.edu> <20200629140928.858507-4-nivedita@alum.mit.edu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200629140928.858507-4-nivedita@alum.mit.edu> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jun 29, 2020 at 10:09:24AM -0400, Arvind Sankar wrote: > From: Ard Biesheuvel > > 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 > Acked-by: Arvind Sankar > Signed-off-by: Arvind Sankar > From: Ard Biesheuvel > 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 -- Kees Cook