From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753614AbeEWATs (ORCPT ); Tue, 22 May 2018 20:19:48 -0400 Received: from mail-pl0-f67.google.com ([209.85.160.67]:38920 "EHLO mail-pl0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751872AbeEWATq (ORCPT ); Tue, 22 May 2018 20:19:46 -0400 X-Google-Smtp-Source: AB8JxZoS1v8X3SWpiEeZjaR55VcUFLzuuUB1lSBe2bYfvf78x0nDRDfdViuI9CYgfPdEwSeXdg/liw== From: Laura Abbott To: Andy Lutomirski , mjw@fedoraproject.org, "H . J . Lu" , Masahiro Yamada Cc: Laura Abbott , Linus Torvalds , X86 ML , linux-kernel@vger.kernel.org, Nick Clifton , Cary Coutant , linux-kbuild@vger.kernel.org Subject: [PATCHv3 0/2] Salted build ids via linker sections Date: Tue, 22 May 2018 17:19:37 -0700 Message-Id: <20180523001939.9431-1-labbott@redhat.com> X-Mailer: git-send-email 2.17.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, This is v3 of the series to allow unique build-ids in the kernel. As a reminder of the context: "" In Fedora, the debug information is packaged separately (foo-debuginfo) and can be installed separately. There's been a long standing issue where only one version of a debuginfo info package can be installed at a time. Mark Wielaard made an effort for Fedora 27 to allow parallel installation of debuginfo (see https://fedoraproject.org/wiki/Changes/ParallelInstallableDebuginfo for more details) Part of the requirement to allow this to work is that build ids are unique between builds. The existing upstream rpm implementation ensures this by re-calculating the build-id using the version and release as a seed. This doesn't work 100% for the kernel because of the vDSO which is its own binary and doesn't get updated. After poking holes in a few of my ideas, there was a discussion with some people from the binutils team about adding --build-id-salt to let ld do the calculation debugedit is doing. There was a counter proposal made about adding some extra information via a .comment which will affect the build id calculation but just get stripped out. "" I mentioned in the previous version that there were problems with sporadic build failures. v3 switches to generating the linker script directly instead of a header + a linker script to avoid this problem. I also dropped the Kconfig completely (I can add it back as a guard if this seems not small enough to want all the time). I've also dropped the RFC tag since it's well formed enough at this point. Laura Abbott (2): kbuild: Introduce build-salt linker script x86/vdso: Add build salt to the vDSO Makefile | 4 +++- arch/x86/entry/vdso/Makefile | 4 +++- scripts/.gitignore | 1 + scripts/Makefile | 9 ++++++++- scripts/gensalt | 22 ++++++++++++++++++++++ scripts/link-vmlinux.sh | 3 ++- 6 files changed, 39 insertions(+), 4 deletions(-) create mode 100755 scripts/gensalt -- 2.17.0