From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 CB6AF374E7A for ; Thu, 24 Sep 2026 03:24:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790220290; cv=none; b=n9+gKa2lKcAZxTCVqnMdUPBsEBMa0yJtZBCCKd7FjqcXHoYP3Lbjyp7isLH/yc9XNAb7YvmsQSdFMANi0PIGryYAOAAM5nuYoR2w8wLSTsIjvqEAhUGhdknXwW5dnRJkDfa5W73o5C8RnkngSX0Fjo0QTEDs0YfEMW9lSN8upaI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790220290; c=relaxed/simple; bh=cwbLYLitS7LEcU4XgagnKGY2mKrmOuDb6Qdoi3vYmAU=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=thBg0//92LdcV5y/X5h/BEGSLkYUSr39Fa3tnjMY3FJv+DjShD3JGq0lmu0DD/cyhFhyIrA0Rj2R8nJNfCyvqeXzuucniXoxfmEGV75c2OLUu1TbF6DB0vw1H9naNrIMz6fQGs9/mOo8Hj86/WOrP5oyIQNo2MFGTPXUMWjvnWI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=iVIi/+0d; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="iVIi/+0d" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2262C1F000FF; Thu, 24 Sep 2026 03:24:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1790220289; bh=dS6xM6YKItsqX75coPt9kSWsKNwEnbwlGIyOx/9zO8I=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=iVIi/+0dEQUUXrlcQIzjIda5APKTOT2TOqRxnewI7oKhPL7+264rB+gfcnAGJRhp+ p8g0qSYubY/+9TwrNUvZ8KGZs4FjbHV7DBbvlO0LVuFLXBd1+vIcRfYaAL9Uxl7VLU cyyseibybD8Pu44eWCgpLxNlhQ59AfiPYmiTFlpx46M/UmeKBXRcJnNRPyOevUZeMF ufN57uHZHD7CVx2XPVx6pcUT1QIDXK0wOpVIJs9EN/j74vwcTW1Whoa6F1XDoQoH1B haAn05ePyB/1uhPqUB7iXjYFwIbRXDXobmHYts2lhMuN+lConEENbnzGl1oHde5gf3 wpkk3xXXO5WSQ== Date: Wed, 23 Sep 2026 20:24:46 -0700 From: Eric Biggers To: Borislav Petkov Cc: x86@kernel.org, Thomas Gleixner , Ingo Molnar , Dave Hansen , linux-kernel@vger.kernel.org, "H . Peter Anvin" , Arnd Bergmann Subject: Re: [PATCH] x86/fpu: Remove unnecessary checks for X86_FEATURE_FPU Message-ID: <20260924032446.GA5048@sol> References: <20260831185706.90103-1-ebiggers@kernel.org> <20260923211450.GBarRBSoXGFKvUBwe7@fat_crate.local> 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: <20260923211450.GBarRBSoXGFKvUBwe7@fat_crate.local> On Wed, Sep 23, 2026 at 02:14:50PM -0700, Borislav Petkov wrote: > On Mon, Aug 31, 2026 at 11:57:06AM -0700, Eric Biggers wrote: > > Since commit ab05214025ee ("x86/fpu: Remove MATH_EMULATION and related > > glue code"), X86_FEATURE_FPU is mandatory. If it's absent, the kernel > > halts execution in fpu__init_system_early_generic(). Remove unnecessary > > checks for X86_FEATURE_FPU that occur later in core x86 code. > > > > Signed-off-by: Eric Biggers > > --- > > arch/x86/kernel/fpu/bugs.c | 4 ---- > > arch/x86/kernel/fpu/core.c | 2 +- > > arch/x86/kernel/fpu/init.c | 2 -- > > arch/x86/kernel/fpu/xstate.c | 5 ----- > > 4 files changed, 1 insertion(+), 12 deletions(-) > > Sashiko might have a point here: > > https://sashiko.dev/#/patchset/20260831185706.90103-1-ebiggers%40kernel.org Sure, there's more stuff that can be removed too. It will make for a large patch, but I'll try to get the rest in x86/fpu code. - Eric