From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) (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 7DC542D3755 for ; Wed, 17 Dec 2025 12:47:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.50.34 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765975642; cv=none; b=MGzlI65EA8d3vZOt6i0cHZ26UwhGESf649no7EHvSC+JnSISFqg6WAwT3UAkKupYaC0JFOppDPyh6eCEBuR50pPuiO5q+NeNCMtYhNoOxze9lz5T6kr5OuYwZBqFbcYiHjc76unAivSLXhm25wT3kG1ofUmRa4udzxTimcsdpLQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765975642; c=relaxed/simple; bh=p6CCgrjaU1ZubiRRwRzFe4NHG23Zpsaw4zXMXbvkDuU=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=hnoxD+DIJyivUbinZ/65cFxe3+7A3dCl8eqG2xdpxNFhT0cFZAP87pp+GGNyffFq09Bi5lgVAV9wVA8UXdO1fraJ3hZISSe1lBEuzD01RjOpOAJwZ8jGsy65Y1Qh45lM4j0schYR8kfKxn21+TN4CHbbnmi2dXX92t/tFvVZV2Q= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=o2GfNMcF; arc=none smtp.client-ip=90.155.50.34 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="o2GfNMcF" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=L1VnR7rSv+IxYzkEZQSVwKOEFM8DNqkCl20PifYzxCo=; b=o2GfNMcFVTOCHNzpjo+P4HyuLK eP1th4i7QPuwL8Rh3ki3K/mpf+9COPzHjGjCvywTwap0uilMm5h3k9pO15KeQ7rrP54OFp+2yLXNp hLJUhi6dcbFtgu1pE3IbPpUaBFmeRIZg5HOHio8UQG8vpB1+6ruBg7HDJVRkW7RfGg6pEsRD5cyhZ Ve5vNFXC5yjaphgvIkPw4vXfk+/+g3/Yko9sguxLyqqk6xNbvs6Tr5xkFQzByBFlfoBQuI1JMnXG5 lVwZPjbuE/ffyHP3KvUKgXlc3LIyrIjEGroZxkb+RuqM8BAlLkBduNJ+SIDtscLIZ0oYbMam8iHnE /LI6LQ7Q==; Received: from 2001-1c00-8d85-5700-266e-96ff-fe07-7dcc.cable.dynamic.v6.ziggo.nl ([2001:1c00:8d85:5700:266e:96ff:fe07:7dcc] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.98.2 #2 (Red Hat Linux)) id 1vVqvy-00000004iSN-3TGL; Wed, 17 Dec 2025 12:47:14 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id C274F3005E0; Wed, 17 Dec 2025 13:47:13 +0100 (CET) Date: Wed, 17 Dec 2025 13:47:13 +0100 From: Peter Zijlstra To: Jean Delvare Cc: LKML Subject: Re: Build breakage caused by the use of UDB Message-ID: <20251217124713.GD3708021@noisy.programming.kicks-ass.net> References: <20251217124119.5832bba7@endymion> <20251217123536.GE3707891@noisy.programming.kicks-ass.net> 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: <20251217123536.GE3707891@noisy.programming.kicks-ass.net> On Wed, Dec 17, 2025 at 01:35:36PM +0100, Peter Zijlstra wrote: > On Wed, Dec 17, 2025 at 12:44:23PM +0100, Jean Delvare wrote: > > Hi Peter, > > > > Kernel v6.18.1 doesn't build on x86_64 for me. The build failure is: > > > > make[1]: Entering directory '/home/khali/src/linux-6.18/drivers/net/wireless/realtek/rtlwifi/rtl8192c' > > CC [M] main.o > > CC [M] dm_common.o > > CC [M] fw_common.o > > CC [M] phy_common.o > > CHECK main.c > > fw_common.c: Assembler messages: > > fw_common.c:416: Error: unknown pseudo-op: `.byte0x0f' > > fw_common.c:391: Error: unknown pseudo-op: `.byte0x0f' > > make[3]: *** [/home/khali/src/linux-6.18/scripts/Makefile.build:287: fw_common.o] Error 1 > > make[3]: *** Waiting for unfinished jobs.... > > CHECK dm_common.c > > phy_common.c: Assembler messages: > > phy_common.c:58: Error: unknown pseudo-op: `.byte0x0f' > > phy_common.c:67: Error: unknown pseudo-op: `.byte0x0f' > > ../wifi.h:3033: Error: unknown pseudo-op: `.byte0x0f' > > ../wifi.h:3033: Error: unknown pseudo-op: `.byte0x0f' > > phy_common.c:807: Error: unknown pseudo-op: `.byte0x0f' > > phy_common.c:714: Error: unknown pseudo-op: `.byte0x0f' > > make[3]: *** [/home/khali/src/linux-6.18/scripts/Makefile.build:287: phy_common.o] Error 1 > > make[2]: *** [/home/khali/src/linux-6.18/Makefile:2010: .] Error 2 > > make[1]: *** [/home/khali/src/linux-6.18/Makefile:248: __sub-make] Error 2 > > make[1]: Leaving directory '/home/khali/src/linux-6.18/drivers/net/wireless/realtek/rtlwifi/rtl8192c' > > make: *** [Makefile:248: __sub-make] Error 2 > > > > I bisected it down to: > > > > commit 85a2d4a890dce3cfc9c14aa91afc3dd7af8e3bf5 > > Author: Peter Zijlstra > > Date: Mon Sep 1 12:49:58 2025 +0200 > > > > x86,ibt: Use UDB instead of 0xEA > > > > Reverting this commit allows me to build v6.18.1. > > > > I must confess this is all way beyond me and I have no idea how this > > change can cause such a build failure, but it does. If it matters, my > > compiler is gcc 8.2.1. > > Well, that is somewhat unexpected. None of the build robots fingered > this. Is there a particular .config I should try? > > I don't seem to have 8.2.1 at hand, but I'll try with 8.3.0. I had to (obviously) enable the RTL8192 bits, but then, yes. gcc-8 fails to build this while gcc-10 doesn't seem to have any problems (for some reason my random dev machine of the day doesn't seem to have gcc-9). Let me prod at this for a bit. But also, is there a good reason you're using this stone-age compiler? :-) And yes, its our minimum supported, so I suppose I should go fix, but other than build testing, you really shoulnd't be using it.