From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id BC5E11C84C6 for ; Fri, 25 Jul 2025 09:08:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753434513; cv=none; b=EJtPiZ8CKmL5nrEwphnr0vCCTlymjmyK5rnX0p80FOktKInj4IIQsjEHgrM6AgHbyuLAXSLuj24jPVDu6E+xED+68vEJeg8iYu/+pDWKL6qWa+YbLvyHCOYIZq2gtL2KiKmYXmqHIQzFP0s6mLzNE+npGgxqNWEYatGYl1K88NQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753434513; c=relaxed/simple; bh=De6jJ9WFKxdiSckwlbxEIJ8N2MPXJWidcPZwaY2r0ig=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=GX3K74Nf8nR+hfWg22UngihOb+NU9hS3HW9H+ZLuMjkrI3RHxcYvm9WVNg+8FbMb6mz8SycMOX04aSo1yK1xjHtTzBWQ7Lo2uIFgvc4RPapfMFcfO1uPdpFnIGCTMZX7J9XA+E6zq+cqka61+xJIk0SLfdWwxm6j3HCugtTXf70= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 1D2F5176C; Fri, 25 Jul 2025 02:08:24 -0700 (PDT) Received: from J2N7QTR9R3 (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id B08203F66E; Fri, 25 Jul 2025 02:08:29 -0700 (PDT) Date: Fri, 25 Jul 2025 10:08:23 +0100 From: Mark Rutland To: Arnd Bergmann Cc: Jeff Johnson , linux-kernel@vger.kernel.org, Peter Zijlstra , Josh Poimboeuf Subject: Re: build failure with crosstools gcc 15.1.0 Message-ID: References: <8362b484-ea77-4825-8ccb-d5acad660102@oss.qualcomm.com> <617201f8-1ad7-4403-b195-8c80d35ea30f@app.fastmail.com> 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: On Thu, Jul 24, 2025 at 05:37:11PM +0200, Arnd Bergmann wrote: > On Thu, Jul 24, 2025, at 12:44, Mark Rutland wrote: > > On Fri, Jul 04, 2025 at 03:25:49PM +0200, Arnd Bergmann wrote: > >> On Mon, Jun 23, 2025, at 21:52, Jeff Johnson wrote: > >> > vmlinux.o: warning: objtool: ncsi_process_next_channel() falls through > >> > to next function ncsi_channel_monitor.cold() > >> > vmlinux.o: error: objtool [elf.c:1360]: elf_write: elf_update failed: > >> > >> Sorry for the late reply, have you figured it out in the meantime? > >> > >> I couldn't immediately reproduce it, so it may already be fixed > >> in linux-next. > > > > $ git clean -fdx > > $ usekorg 15.1.0 make ARCH=x86_64 CROSS_COMPILE=x86_64-linux- defconfig > > $ usekorg 15.1.0 make ARCH=x86_64 CROSS_COMPILE=x86_64-linux- -j56 > > This is very close to what I use. I assume you are also on an arm64 > host here? Nope, this was on an x86-64 host running Debian 11.10. I *DON'T* see this when building on an arm64 host running Debain 12.11, using the (arm64 builds of) the GCC 15.1.0 binaries from kernel.org. That suggests this is down to something on the build host. Given that the failure is seen at a call to elf_update() (which is part of libelf): /* Write all changes to the file. */ if (elf_update(elf->elf, ELF_C_WRITE) < 0) { ERROR_ELF("elf_update"); return -1; } ... I suspect the version of libelf might have something to do with it. The x86 host has libelf-dev 0.183-1 whereas the arm64 host has libelf-dev 0.188-2.1, so maybe there's something added or fixed between those versions. Otherwise, looking at the resulting .config files, the only differences are: * The x86 host has: CONFIG_PAHOLE_VERSION=120 CONFIG_CC_HAS_MARCH_NATIVE=y # CONFIG_X86_NATIVE_CPU is not set * The arm64 host has: CONFIG_PAHOLE_VERSION=124 ... and otherwise everything else is the same. AFAICT, pahole shouldn't affect the build since none of the BTF options are selected. Mark.