Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750839AbcKXFAK (ORCPT ); Thu, 24 Nov 2016 00:00:10 -0500 Received: from mail-wj0-f193.google.com ([209.85.210.193]:33713 "EHLO mail-wj0-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750696AbcKXFAI (ORCPT ); Thu, 24 Nov 2016 00:00:08 -0500 Date: Thu, 24 Nov 2016 05:40:28 +0100 From: Ingo Molnar To: Adam Borowski , Michal Marek Cc: Philip Muller , linux-kernel@vger.kernel.org, Nicholas Piggin , Greg Kroah-Hartman , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Linus Torvalds , Andrew Morton , Peter Zijlstra Subject: Re: [PATCH] x86/kbuild: enable modversions for symbols exported from asm Message-ID: <20161124044028.GA12704@gmail.com> References: <20161123205338.GA12050@angband.pl> <20161123210256.31501-1-kilobyte@angband.pl> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20161123210256.31501-1-kilobyte@angband.pl> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2613 Lines: 67 * Adam Borowski wrote: > Commit 4efca4ed ("kbuild: modversions for EXPORT_SYMBOL() for asm") adds > modversion support for symbols exported from asm files. Architectures > must include C-style declarations for those symbols in asm/asm-prototypes.h > in order for them to be versioned. > > Add these declarations for x86, and an architecture-independent file that > can be used for common symbols. > > User impact: kernels may fail to load modules at all when > CONFIG_MODVERSIONS=y. > > Signed-off-by: Adam Borowski > Tested-by: Kalle Valo > Acked-by: Nicholas Piggin > Tested-by: Peter Wu > Tested-by: Oliver Hartkopp > --- > Changes: corrected Peter Wu's address, added Tested-by: Oliver. > This is an unsplit version (x86/include/ and include/ together). > > arch/x86/include/asm/asm-prototypes.h | 12 ++++++++++++ > include/asm-generic/asm-prototypes.h | 7 +++++++ > 2 files changed, 19 insertions(+) > create mode 100644 arch/x86/include/asm/asm-prototypes.h > create mode 100644 include/asm-generic/asm-prototypes.h Michal, I'm quite unhappy about how the offending commit that broke modversions for essentially _everyone_ who does more complex modular builds on x86 ended up upstream: commit 4efca4ed05cbdfd13ec3e8cb623fb77d6e4ab187 Author: Nicholas Piggin AuthorDate: Tue Nov 1 12:46:19 2016 +1100 Commit: Michal Marek CommitDate: Tue Nov 1 16:20:17 2016 +0100 kbuild: modversions for EXPORT_SYMBOL() for asm Allow architectures to create asm/asm-prototypes.h file that provides C prototypes for exported asm functions, which enables proper CRC versions to be generated for them. scripts/Makefile.build | 78 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++------ 1 file changed, 72 insertions(+), 6 deletions(-) It was applied 4 hours after it was sent in the -rc3 timeframe, and then it went upstream in -rc5: "Here are some regression fixes for kbuild: - modversion support for exported asm symbols (Nick Piggin). The affected architectures need separate patches adding asm-prototypes.h. ... the fine merge log even says that the commit 'needs separate patches'! It's still totally broken upstream and it didn't fix any regressions AFAICS (or if it did then its changelog was very silent on that fact). Why was such a complex patch applied and why isn't it reverted or fixed upstream? Thanks, Ingo