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 52EB02868A9; Tue, 29 Jul 2025 09:01:29 +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=1753779690; cv=none; b=fa0/DXmSm04LQGdwUyF4/ZeHHLt+F5UBGHLMUk0crb8FdtpqpXqO3pQbfoUSlOrbStcennTmhnEF80zMa/2vPcOkrNsT/X181r/LI7tqUevNUPC2B5fmr6aUn1qOjwgoLm+HKKJindjJDzJj4ADg7VzDZPidL2EUwpP+SdBX3Jw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753779690; c=relaxed/simple; bh=XO+eOqdRW/QOnjLYBTQQzg5lu44bRFGUBptUmbIG57Y=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Wti4g3RTTzTbVAOdTOHsnXaHgvcZD191rITgAIf+0b1Pt9KfFfA7glMzI8zNK4H+tPZ9niesau55D6La9mFRdj/oiz/raO1ElKh96EFMCpITrlT7g8bxVKThJRnrwx42mEJMskt5E5f2BlNs7zK2AsJVdnWQlGWTi2K9GnEv5Cs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=D+ohNaPN; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="D+ohNaPN" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 235C1C4CEF7; Tue, 29 Jul 2025 09:01:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1753779689; bh=XO+eOqdRW/QOnjLYBTQQzg5lu44bRFGUBptUmbIG57Y=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=D+ohNaPNIv0UmxVGVC5BgNDxyiz9SrcUdlCwdCadP7OlJL19Bol3xWHOI7G+3hwGK afosDPFIwZeULzbQ6dOUEebZtaq+wF1Q4aTfvGYF49eS717JCbJj2PHtAb3goeVu7K Fk+NYIUu3V8+emvSIOH2EGeYd79Hd5eC14sywvms= Date: Tue, 29 Jul 2025 11:01:26 +0200 From: Greg KH To: Suchit Karunakaran Cc: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, darwi@linutronix.de, sohil.mehta@intel.com, peterz@infradead.org, ravi.bangoria@amd.com, skhan@linuxfoundation.org, linux-kernel-mentees@lists.linux.dev, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] x86/intel: Fix always false range check in x86_vfm model matching Message-ID: <2025072947-laziness-unlikable-e0f3@gregkh> References: <20250729042621.6403-1-suchitkarunakaran@gmail.com> <2025072925-lint-agreement-77e8@gregkh> <2025072931-recount-stifling-73e8@gregkh> Precedence: bulk X-Mailing-List: linux-kernel-mentees@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: On Tue, Jul 29, 2025 at 02:24:43PM +0530, Suchit Karunakaran wrote: > On Tue, 29 Jul 2025 at 13:26, Greg KH wrote: > > > > On Tue, Jul 29, 2025 at 12:23:27PM +0530, Suchit Karunakaran wrote: > > > On Tue, 29 Jul 2025 at 10:58, Greg KH wrote: > > > > > > > > On Tue, Jul 29, 2025 at 09:56:21AM +0530, Suchit Karunakaran wrote: > > > > > Fix a logic bug in early_init_intel() where a conditional range check: > > > > > (c->x86_vfm >= INTEL_P4_PRESCOTT && c->x86_vfm <= INTEL_P4_WILLAMETTE) > > > > > was always false due to (PRESCOTT) being numerically greater than the > > > > > upper bound (WILLAMETTE). This triggers:-Werror=logical-op: > > > > > logical ‘and’ of mutually exclusive tests is always false > > > > > The fix corrects the constant ordering to ensure the range is valid: > > > > > (c->x86_vfm >= INTEL_P4_PRESCOTT && c->x86_vfm <= INTEL_P4_CEDARMILL) > > > > > > > > > > Fixes: fadb6f569b10 ("x86/cpu/intel: Limit the non-architectural > > > > > constant_tsc model checks") > > > > > > > > > > Signed-off-by: Suchit Karunakaran > > > > > > > > > > Changes since v1: > > > > > - Fix incorrect logic > > > > > --- > > > > > arch/x86/kernel/cpu/intel.c | 2 +- > > > > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > > > > > > > diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c > > > > > index 076eaa41b8c8..6f5bd5dbc249 100644 > > > > > --- a/arch/x86/kernel/cpu/intel.c > > > > > +++ b/arch/x86/kernel/cpu/intel.c > > > > > @@ -262,7 +262,7 @@ static void early_init_intel(struct cpuinfo_x86 *c) > > > > > if (c->x86_power & (1 << 8)) { > > > > > set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC); > > > > > set_cpu_cap(c, X86_FEATURE_NONSTOP_TSC); > > > > > - } else if ((c->x86_vfm >= INTEL_P4_PRESCOTT && c->x86_vfm <= INTEL_P4_WILLAMETTE) || > > > > > + } else if ((c->x86_vfm >= INTEL_P4_PRESCOTT && c->x86_vfm <= INTEL_P4_CEDARMILL) || > > > > > (c->x86_vfm >= INTEL_CORE_YONAH && c->x86_vfm <= INTEL_IVYBRIDGE)) { > > > > > set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC); > > > > > } > > > > > -- > > > > > 2.50.1 > > > > > > > > > > > > > > > > > > Hi, > > > > > > > > This is the friendly patch-bot of Greg Kroah-Hartman. You have sent him > > > > a patch that has triggered this response. He used to manually respond > > > > to these common problems, but in order to save his sanity (he kept > > > > writing the same thing over and over, yet to different people), I was > > > > created. Hopefully you will not take offence and will fix the problem > > > > in your patch and resubmit it so that it can be accepted into the Linux > > > > kernel tree. > > > > > > > > You are receiving this message because of the following common error(s) > > > > as indicated below: > > > > > > > > - You have marked a patch with a "Fixes:" tag for a commit that is in an > > > > older released kernel, yet you do not have a cc: stable line in the > > > > signed-off-by area at all, which means that the patch will not be > > > > applied to any older kernel releases. To properly fix this, please > > > > follow the documented rules in the > > > > Documentation/process/stable-kernel-rules.rst file for how to resolve > > > > this. > > > > > > > > If you wish to discuss this problem further, or you have questions about > > > > how to resolve this issue, please feel free to respond to this email and > > > > Greg will reply once he has dug out from the pending patches received > > > > from other developers. > > > > > > > > thanks, > > > > > > > > greg k-h's patch email bot > > > > > > Hi Greg, > > > I've a question regarding backporting this fix. Can this fix be > > > backported to stable kernel version 6.15.8? Also, should I send the > > > backport patch only after the initial patch has been merged in > > > mainline or linux-next? > > > > Did you read the document that my bot linked to above? It should answer > > those questions :) > > > > thanks, > > > > greg k-h > > Hi Greg, > I did go through the document you linked. I just wanted to clarify > about the backporting process, especially since the merge window has > already started and it might take some time for this to be merged into > mainline. Regardless, I'll send the backport patch after the initial > one has been merged. As the document states, a commit must be in Linus's tree first, before we can consider it for any stable release. thanks, greg k-h