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Peter Anvin" , "maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)" , LKML , clang-built-linux , Michael Matz , Fangrui Song , Kees Cook Subject: Re: [PATCH 0/2] Stop generating .eh_frame sections Message-ID: <20200224215330.GA560533@rani.riverdale.lan> References: <20200222235709.GA3786197@rani.riverdale.lan> <20200223193715.83729-1-nivedita@alum.mit.edu> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Feb 24, 2020 at 12:49:03PM -0800, Nick Desaulniers wrote: > On Sun, Feb 23, 2020 at 11:37 AM Arvind Sankar wrote: > > > > In three places in the x86 kernel we are currently generating .eh_frame > > sections only to discard them later via linker script. This is in the > > boot code (setup.elf), the realmode trampoline (realmode.elf) and the > > compressed kernel. > > > > Implement Fangrui and Nick's suggestion [1] to fix KBUILD_CFLAGS by > > adding -fno-asynchronous-unwind-tables to avoid generating .eh_frame > > sections in the first place, rather than discarding it in the linker > > script. > > > > Arvind Sankar (2): > > arch/x86: Use -fno-asynchronous-unwind-tables to suppress .eh_frame sections > > arch/x86: Drop unneeded linker script discard of .eh_frame > > Thanks for the series! I've left some feedback for a v2. Would you > mind please including a revert of ("x86/boot/compressed: Remove > unnecessary sections from bzImage") in a v2 series? Our CI being red > through the weekend is no bueno. Sorry about that. Boris already updated tip:x86/boot to only discard eh_frame, so your CI should be ok at least now. > > > > > arch/x86/boot/Makefile | 1 + > > arch/x86/boot/compressed/Makefile | 1 + > > arch/x86/boot/setup.ld | 1 - > > arch/x86/kernel/vmlinux.lds.S | 3 --- > > arch/x86/realmode/rm/Makefile | 1 + > > arch/x86/realmode/rm/realmode.lds.S | 1 - > > drivers/firmware/efi/libstub/Makefile | 3 ++- > > 7 files changed, 5 insertions(+), 6 deletions(-) > > > > -- > > 2.24.1 > > > > > -- > Thanks, > ~Nick Desaulniers