From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D81AA1F948 for ; Wed, 9 Jul 2025 01:21:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752024098; cv=none; b=C3DjZJ+1p0tWZyrILv+E7v7cbJKiUMh1MiN2D3gKsoQCTUpV+/NXTJ9iI7Zqy8l6feyNctFvVE65N/tmEMniO5DD8advJhPtrKEHzAL5YvPohxP0Hc7t8natQ0568aUwu6GaEDjdFpx8uWdBSeLKhtTnHENPQF+V8yPkBdttiBc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752024098; c=relaxed/simple; bh=PrbBICA3NNs4hfUwHx+bIOiAj9282vkiXfbstW+6NBk=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=P8Iy42I9RD5veqLz2V7ATGi2188gTADmA9dBFaYunR2TBY1MJegnPFxtyuvArokL8i6ssK5lH2wHIZUoOhJW9GLfYtyDgJFR2JFLrEU4kw/HfUYgQOBfl6KaoIQeCgPgxRBdt2hFru1jftZ7OI3jE7e8wFDCxdOqVRfePQNH14g= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=LmPRQZuN; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="LmPRQZuN" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1A203C4CEED; Wed, 9 Jul 2025 01:21:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1752024098; bh=PrbBICA3NNs4hfUwHx+bIOiAj9282vkiXfbstW+6NBk=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=LmPRQZuN+R1ssGpiXwqOHMRjxHNN5ADHenwMK3onGd13CofFM+xZ7Z+oHN5f0eGLh q3NYY2Othz61NXhdeZb92Ie2ed/rKp97LCZuBR6VLYOsMHuvulF31Vspur+ejaf/Ld NNonyx0TJklZIx4n7jn+5Npo4FLJHYJUXlRWEUq5j18wD+seYV5ABC+oTywzAvjWN3 la8s0DPM2xB91ohf55zh/QR/C51aWgVCRFDWvs3dh5b4Sf1+kgQi08ZIqwW3Ynut8w 9Ji41Zwh+sefgpTHIJy9jAuqN5jUTL1xZ635kN2BezS4rEVkdTf09fTEBC6mKUmfoO Tm48VIEJstdgA== Date: Tue, 8 Jul 2025 18:21:34 -0700 From: Nathan Chancellor To: Martin Wetterwald Cc: linus.walleij@linaro.org, linux@armlinux.org.uk, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: Linux linking stage broken on ARM with binutils 2.33.1 (BFD) Message-ID: <20250709012134.GA1785682@ax162> References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Hi Martin, On Tue, Jul 08, 2025 at 09:44:44PM +0200, Martin Wetterwald wrote: > When I upgraded from 6.12.22 to 6.12.23 (without changing anything else), the > linking stage of vmlinux broke (arch ARM). > > > /home/.../linux-6.12.23/scripts/link-vmlinux.sh: line 49: 136961 Segmentation fault (core dumped) ${ld} ${ldflags} -o ${output} ${wl}--whole-archive ${objs} ${wl}--no-whole-archive ${wl}--start-group ${libs} ${wl}--end-group ${kallsymso} ${btf_vmlinux_bin_o} ${ldlibs} > > make[2]: *** [/home/.../linux-6.12.23/scripts/Makefile.vmlinux:34: vmlinux] Error 139 > > make[1]: *** [/home/.../linux-6.12.23/Makefile:1179: vmlinux] Error 2 > > make: *** [/home/.../linux-6.12.23/Makefile:224: __sub-make] Error 2 > > This patch seems related: > > > commit 59fc42318305cb38efb4f5565408150419be8451 > > Author: Nathan Chancellor > > Date: Thu Mar 20 22:33:49 2025 +0100 > > > > ARM: 9443/1: Require linker to support KEEP within OVERLAY for DCE > > > > commit e7607f7d6d81af71dcc5171278aadccc94d277cd upstream. > > > > ld.lld prior to 21.0.0 does not support using the KEEP keyword within an > > overlay description, which may be needed to avoid discarding necessary > > sections within an overlay with '--gc-sections', which can be enabled > > for the kernel via CONFIG_LD_DEAD_CODE_DATA_ELIMINATION. > > > > Disallow CONFIG_LD_DEAD_CODE_DATA_ELIMINATION without support for KEEP > > within OVERLAY and introduce a macro, OVERLAY_KEEP, that can be used to > > conditionally add KEEP when it is properly supported to avoid breaking > > old versions of ld.lld. > > > > Cc: stable@vger.kernel.org > > Link: https://github.com/llvm/llvm-project/commit/381599f1fe973afad3094e55ec99b1620dba7d8c > > Reviewed-by: Linus Walleij > > Signed-off-by: Nathan Chancellor > > Signed-off-by: Russell King (Oracle) > > [nathan: Fix conflict in init/Kconfig due to lack of RUSTC symbols] > > Signed-off-by: Nathan Chancellor > > Signed-off-by: Greg Kroah-Hartman > > I'm using BFD linker from GNU binutils 2.33.1 (built using musl-cross-make with > musl 1.2.5 and GCC 14). > > > scripts/ld-version.sh /tmp/arm-linux-musleabihf-ld > > BFD 23301 > > I don't know if it was the intention of the patch, but it is not only changing > a behavior for LLD, but also for BFD: > - Before the patch, ld BFD 2.33.1 was not selecting > HAVE_LD_DEAD_CODE_DATA_ELIMINATION, and my build worked. > - After the patch, ld BFD 2.33.1 is activating > HAVE_LD_DEAD_CODE_DATA_ELIMINATION, and it is segfaulting. > Shouldn't we keep the previous behavior and only select this option when BFD is > >= 2.36.0 (and not just when we have a BFD linker) ? > > The issue is the interaction between LD_CAN_USE_KEEP_IN_OVERLAY and > HAVE_LD_DEAD_CODE_DATA_ELIMINATION. > > Nathan, I've seen your proposal here: https://lkml.org/lkml/2025/7/5/431. > I confirm it also fixes the issue on my side. Should I propose the patch? Yes, your analysis is spot on, sorry again for the breakage :( I sent that diff to the list formally yesterday: https://lore.kernel.org/all/20250707-arm-fix-dce-older-binutils-v1-1-3b5e59dc3b26@kernel.org/ I plan to put it in Russell's patch tracker for application in the next couple of days, I wanted to wait a few days for the opportunity for review. Cheers, Nathan