From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mta1.formilux.org (mta1.formilux.org [51.159.59.229]) (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 F33CC33343E; Mon, 5 Jan 2026 08:31:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=51.159.59.229 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767601884; cv=none; b=gOSegYnu4GbX0NYsQi+QsE7A0VNHDojnHoxiHpdI7QLyytqD1j7PH6qQjP5lLzEjUVYtExBD2kQGEOJQ6JugNTSYHqySfyzsvmEHjI50op/zvi91HzbGPIMY/EYycjv7/VEp0E31qCDf8BftioviEYUEqHi5giDb18hB/HIqmzY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767601884; c=relaxed/simple; bh=gv6KdDFJISABMjgCEf5Xsb/e5mJpBEAPd8hEpew9Ppo=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=sK3mJ3JD5k5v2WC7PFUG8te8d0GXaiSCMdypZaQPSjBU2vv+gwLtWeAV3b+1pmiZXwDJRF3xfwAG7Ouq6hmm+ImjWevlqqd//D+zQegTBXBqEwtR+lGc0o85ZBZcDwm4j5k/nmh5x9aewRCFgMaAGVZbnXw4WaBphTxdV/zl4LI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=1wt.eu; spf=pass smtp.mailfrom=1wt.eu; dkim=pass (1024-bit key) header.d=1wt.eu header.i=@1wt.eu header.b=Kdi701aT; arc=none smtp.client-ip=51.159.59.229 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=1wt.eu Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=1wt.eu Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=1wt.eu header.i=@1wt.eu header.b="Kdi701aT" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1wt.eu; s=mail; t=1767601880; bh=Q37A0rzxuWw+vP0tLyMFa4Ua62rbIstKj/79C6auIec=; h=From:Message-ID:From; b=Kdi701aTAPjACorCt4yLVj177twQpFX7ZMjEFcFlpJZGtnUCDQXprwnRF43mH4FYx 3hRBWFAN54WSmC0BHdm+MV4H2Ljve4+GohFAGoXYxIcCNn5Gq2zI520i1/d7ABH97a e61rFYfSKdbhR9W/ll7eg07QC9dbKs2R8foZ1vWc= Received: from 1wt.eu (ded1.1wt.eu [163.172.96.212]) by mta1.formilux.org (Postfix) with ESMTP id EE821C0943; Mon, 05 Jan 2026 09:31:19 +0100 (CET) Date: Mon, 5 Jan 2026 09:31:19 +0100 From: Willy Tarreau To: Thomas =?iso-8859-1?Q?Wei=DFschuh?= Cc: Shuah Khan , linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] selftests/nolibc: fix sparc32 tests with -mcpu=v9 Message-ID: References: <20260104-nolibc-sparc32-fix-v1-1-e341b06cbdb7@weissschuh.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=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: On Mon, Jan 05, 2026 at 09:19:16AM +0100, Thomas Weißschuh wrote: > On 2026-01-05 08:44:50+0100, Willy Tarreau wrote: > > Hi Thomas, > > > > On Sun, Jan 04, 2026 at 11:14:13PM +0100, Thomas Weißschuh wrote: > > > Since LLVM commit 39e30508a7f6 ("[Driver][Sparc] Default to -mcpu=v9 for > > > 32-bit Linux/sparc64 (#109278)"), clang defaults to -mcpu=v9 for 32-bit > > > SPARC builds. -mcpu=v9 generates instructions which are not recognized > > > by qemu-sparc and qemu-system-sparc. Instead qemu-sparc32plus and > > > qemu-system-sparc64 with a 64-bit kernel and CONFIG_COMPAT are needed. > > > > > > Rework the test setup so that -mcpu=v9 also works correctly. > > > > Hmmm doesn't this mean that we're now unable to emit proper sparc32 > > instructions with this compiler ? > > That depends on the definition of "proper" sparc32 :-) For sure! > Jokes aside, that compiler still supports -mcpu=v8 just fine, > only the default has changed. > > > I don't know which CPUs the kernel > > still supports, but if it still supports these old SS-5, maybe we > > should instead pass the correct -mcpu to clang so that it emits the > > expected instructions, otherwise we're just hiding the regressing by > > upgrading the test machine beyond what the kernel supports ? > > The 32-bit kernel also runs just fine on QEMU SS-5. OK! > My reasoning was more that we now test both the v8 and v9 code paths in > nolibc. But in the end it doesn't really matter, as it is the same > kernel interface for v8 and v9. We can also just specify -mcpu=v8. > I'll do that for v2. OK thank you for checking and explaining! Willy