From: Adam Borowski Subject: Re: [PATCH] x86/kbuild: enable modversions for symbols exported from asm Date: Tue, 29 Nov 2016 18:05:22 +0100 Message-ID: <20161129170522.GA3441@angband.pl> References: <20161129131922.GA31466@angband.pl> <20161129135118.24696-1-kilobyte@angband.pl> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: Resent-Message-ID: List-URL: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Archive: https://lists.debian.org/msgid-search/20161129170522.GA3441@angband.pl To: Linus Torvalds Cc: Greg Kroah-Hartman , Linux Kbuild mailing list , Michal Marek , Ben Hutchings , Debian kernel maintainers , "linux-arch@vger.kernel.org" , Arnd Bergmann , Ingo Molnar , Nicholas Piggin , Linux Kernel Mailing List List-Id: linux-arch.vger.kernel.org On Tue, Nov 29, 2016 at 07:27:12AM -0800, Linus Torvalds wrote: > On Nov 29, 2016 5:51 AM, "Adam Borowski" wrote: > > > > > > (a) tested > > > > By many people. > > No. > > I've tested the build *without* this, and it works fine. Michal mentioned "why", let's try "where". I have no idea what setup is required to trigger the problem, but here's a simple sufficient one: Current Debian unstable, amd64. git reset --hard v4.9-rc7 git revert cd3caefb make defconfig CONFIG_MODVERSIONS=y (in my case) CONFIG_BTRFS_FS=y (so I can boot) enable a module for testing, I used CONFIG_EXT4_FS=m make bindeb-pkg dpkg -i linux-image_XXXXX.deb modprobe ext4 [ 63.779490] jbd2: no symbol version for memcpy [ 63.779492] jbd2: Unknown symbol memcpy (err -22) [ 63.779550] jbd2: no symbol version for phys_base [ 63.779551] jbd2: Unknown symbol phys_base (err -22) [ 63.779561] jbd2: no symbol version for memset [ 63.779562] jbd2: Unknown symbol memset (err -22) Not sure which piece of toolchain matters here, someone said binutils. In that case, Fedora ships 2.26.1-1.fc25, they were frozen so couldn't update. Debian is at 2.27.51.20161127-1, Gentoo at 2.27, same for Arch, OpenSUSE; Ubuntu at 2.27.51.20161124-1. Thus, if it's indeed binutils, you'll see the breakage as soon as Fedora recovers from the freeze. Meow!