From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sami Tolvanen Subject: Re: [PATCH 07/22] kbuild: lto: merge module sections Date: Wed, 24 Jun 2020 14:31:29 -0700 Message-ID: <20200624213129.GC26253@google.com> References: <20200624203200.78870-1-samitolvanen@google.com> <20200624203200.78870-8-samitolvanen@google.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-kbuild-owner@vger.kernel.org To: Nick Desaulniers Cc: Masahiro Yamada , Will Deacon , Greg Kroah-Hartman , "Paul E. McKenney" , Kees Cook , clang-built-linux , Kernel Hardening , linux-arch , Linux ARM , Linux Kbuild mailing list , LKML , linux-pci@vger.kernel.org, "maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)" List-Id: linux-arch.vger.kernel.org On Wed, Jun 24, 2020 at 02:01:59PM -0700, 'Nick Desaulniers' via Clang Built Linux wrote: > On Wed, Jun 24, 2020 at 1:33 PM Sami Tolvanen wrote: > > > > LLD always splits sections with LTO, which increases module sizes. This > > change adds a linker script that merges the split sections in the final > > module and discards the .eh_frame section that LLD may generate. > > For discarding .eh_frame, Kees is currently fighting with a series > that I would really like to see land that enables warnings on orphan > section placement. I don't see any new flags to inhibit .eh_frame > generation, or discard it in the linker script, so I'd expect it to be > treated as an orphan section and kept. Was that missed, or should > that be removed from the commit message? It should be removed from the commit message, thanks for pointing it out. Sami From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59714 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2403823AbgFXVbh (ORCPT ); Wed, 24 Jun 2020 17:31:37 -0400 Received: from mail-pj1-x1042.google.com (mail-pj1-x1042.google.com [IPv6:2607:f8b0:4864:20::1042]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A929BC061796 for ; Wed, 24 Jun 2020 14:31:35 -0700 (PDT) Received: by mail-pj1-x1042.google.com with SMTP id b7so2686819pju.0 for ; Wed, 24 Jun 2020 14:31:35 -0700 (PDT) Date: Wed, 24 Jun 2020 14:31:29 -0700 From: Sami Tolvanen Subject: Re: [PATCH 07/22] kbuild: lto: merge module sections Message-ID: <20200624213129.GC26253@google.com> References: <20200624203200.78870-1-samitolvanen@google.com> <20200624203200.78870-8-samitolvanen@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-arch-owner@vger.kernel.org List-ID: To: Nick Desaulniers Cc: Masahiro Yamada , Will Deacon , Greg Kroah-Hartman , "Paul E. McKenney" , Kees Cook , clang-built-linux , Kernel Hardening , linux-arch , Linux ARM , Linux Kbuild mailing list , LKML , linux-pci@vger.kernel.org, "maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)" Message-ID: <20200624213129.DiOy0tPy016JGlFkAvQ48WfVvi3Rd-RpEYdrqi8r2jg@z> On Wed, Jun 24, 2020 at 02:01:59PM -0700, 'Nick Desaulniers' via Clang Built Linux wrote: > On Wed, Jun 24, 2020 at 1:33 PM Sami Tolvanen wrote: > > > > LLD always splits sections with LTO, which increases module sizes. This > > change adds a linker script that merges the split sections in the final > > module and discards the .eh_frame section that LLD may generate. > > For discarding .eh_frame, Kees is currently fighting with a series > that I would really like to see land that enables warnings on orphan > section placement. I don't see any new flags to inhibit .eh_frame > generation, or discard it in the linker script, so I'd expect it to be > treated as an orphan section and kept. Was that missed, or should > that be removed from the commit message? It should be removed from the commit message, thanks for pointing it out. Sami