From nobody Fri Dec 19 12:46:35 2025 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (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 EC0BB2DE202; Wed, 5 Nov 2025 12:31:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=193.142.43.55 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762345900; cv=none; b=ZQvgPmzy00iWf0uKZ852uXkW7nCBpzz4ij2k54mSznMpugHSCjOBO3wPDERpwYb73Q/cY+SJ4eflsxU9YgsFjarm+OtG0RN6IT2y90R8rNRLzRr+m5NvkwwjYwSWYPGR+OzAeYgc/QiVftaHGNV0Ux/kQCEEO8x5CtE5Ql4V49A= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762345900; c=relaxed/simple; bh=R0xIUk5xUk5kjTH1s/f7OZ2/U/P7P9oA6a70auF7DK0=; h=Date:From:To:Subject:Cc:MIME-Version:Message-ID:Content-Type; b=gtb4j1BzwBiBh6zJ0RyBwW24RAe0aJMsQmE+7qc3eaAM/EhLXWpEulTq4bSYgGLEtcqh6H7Dv+BVDTI4fQVsHP+quZiVwcIR3jDw4x//R4VR6s85rWCQidetSdhqAETzRMoQ1Th5DvwC7B/298aBtYpivDxIaiWQdH+XmdR1Tkw= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de; spf=pass smtp.mailfrom=linutronix.de; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=OcOEff3u; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=h8w1hdwk; arc=none smtp.client-ip=193.142.43.55 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linutronix.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="OcOEff3u"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="h8w1hdwk" Date: Wed, 05 Nov 2025 12:31:25 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1762345890; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=ZN5gtsvEQm25Odxnls5yakPee5U15HOSC/cewgMDyHE=; b=OcOEff3uWZVpW2HuvrOl3rKRrjjj46vONcfwl0uECOJYedB0dl9/yjolRP01dLwEFoPqUi rwStyEKTCgNu7oIJeruHdn0Z2rf/zM3A7XjM8kSTlicf1TUcsD1OypwUsv7WTaTQcjgu3f FT/UlsddL+nPGSg4/ChSkexu9jhOQpQiYG7ANilgk8F119cwW+mjQaqRBcaDtt5OsB/7ih 4bWnRYtd/h/bXRodYXYPs/vIDsQJ7wdSBje95sSxqdqnTkAstzUbg6+crzv6rQ0cwB6SL+ BVvAeLkz11FJc8AH4Lzj7bZNu2FG7JrMrtyjOHk/XWvi2KCKWiKK3mostztgbQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1762345890; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=ZN5gtsvEQm25Odxnls5yakPee5U15HOSC/cewgMDyHE=; b=h8w1hdwkowUFpYbyq7f7uPjeESxh3iBuFp3LIBjqLXZV78czk8vF23B4yDo3n4daI40TsE 9dwOHYuyOCD0NNAA== From: "tip-bot2 for Marc Herbert" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: x86/misc] x86/msr: Add CPU_OUT_OF_SPEC taint name to "unrecognized" pr_warn(msg) Cc: Marc Herbert , "Borislav Petkov (AMD)" , x86@kernel.org, linux-kernel@vger.kernel.org Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-ID: <176234588546.2601451.13367192916449580721.tip-bot2@tip-bot2> Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Precedence: bulk Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable The following commit has been merged into the x86/misc branch of tip: Commit-ID: 41f4767000667f402be2f1ccd70cd215bfc41ec3 Gitweb: https://git.kernel.org/tip/41f4767000667f402be2f1ccd70cd215b= fc41ec3 Author: Marc Herbert AuthorDate: Mon, 03 Nov 2025 03:08:11=20 Committer: Borislav Petkov (AMD) CommitterDate: Wed, 05 Nov 2025 13:14:42 +01:00 x86/msr: Add CPU_OUT_OF_SPEC taint name to "unrecognized" pr_warn(msg) While restricting access, a7e1f67ed29f ("x86/msr: Filter MSR writes") also added warning and started tainting the kernel. But the warning message never mentioned tainting. Moreover, this uses the "CPU_OUT_OF_SPEC" flag which is not clearly related to MSRs: that flag is overloaded by several, fairly different situations, including some much scarier ones. So, without an expert around (thank you Dave Hansen), it would have been practically impossible to root cause the tainting from just the log file at hand. So it would be prudent to explicitly mention in the logs when the tainting happens so that debugging crashes can be made easier. Fix this by simply appending the CPU_OUT_OF_SPEC flag to the warning messag= e. This readability issue happened when staring at logs involving the Intel Memory Latency Checker (among many other things going on in that log). The = MLC disables hardware prefetch. [ bp: Massage and extend commit message. ] Signed-off-by: Marc Herbert Signed-off-by: Borislav Petkov (AMD) Link: https://lore.kernel.org/r/20251101-tainted-msr-v1-1-e00658ba04d4@linu= x.intel.com --- arch/x86/kernel/msr.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kernel/msr.c b/arch/x86/kernel/msr.c index e17c16c..4469c78 100644 --- a/arch/x86/kernel/msr.c +++ b/arch/x86/kernel/msr.c @@ -98,7 +98,7 @@ static int filter_write(u32 reg) if (!__ratelimit(&fw_rs)) return 0; =20 - pr_warn("Write to unrecognized MSR 0x%x by %s (pid: %d).\n", + pr_warn("Write to unrecognized MSR 0x%x by %s (pid: %d), tainting CPU_OUT= _OF_SPEC.\n", reg, current->comm, current->pid); pr_warn("See https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git/= about for details.\n"); =20