From nobody Thu Nov 28 15:56:36 2024 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 5173C18EAB; Mon, 30 Sep 2024 17:38:33 +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=1727717915; cv=none; b=hNGadAW4FP4moXlI5y8FwDQ7FsDlohLwocWqll7cCHwRNQBF+IGWHMuzTqfY1UKJF1N/O9UcNo/RD4EdWgQdMwZ4dRYnlt2sthpVTQbX/murQoyufz+r5Sj4LlcJLIbaus5R/gX8RGJBFYMlWKaPi623Fi12g6VfZz1fNl7eulg= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727717915; c=relaxed/simple; bh=CwR/jaJJf5gRiS2tIxZMwYJTi9ewZBM0JWaufMRqG50=; h=Date:From:To:Subject:Cc:MIME-Version:Message-ID:Content-Type; b=cOmxj5liemq58k/0j6pUt0HyI9N1ZUTezX32KYlG5j0InkNKP15b+EB87HcZP7vLCiUgAJPJyqk0RoEeonQpT24sdI5RTY1aL6pPRlb+d4Kwm1ttIHM9hroirtYcMfOKaiUoVIV9AVlFnyI0XFwpGA6V3cDHsmBZihxdCCzpiiY= 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=YOPDBfPa; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=zLAKOlMu; 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="YOPDBfPa"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="zLAKOlMu" Date: Mon, 30 Sep 2024 17:38:29 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1727717911; 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=qp5nwg96y87OpSLZA/vVu33PD/rs5eKJFKqagbVKAw0=; b=YOPDBfPa4txdaG/FchV1pfamwQ/AUbUAeL4+JKdJ6vV0gfoOf7hOIO9PtW7DxZPoPeGpFW tAMIOztUFgf1156aDypF9kE4W4xC2xvTA5ZdJYOxFAvGPdHhUb09aJTlysnl79D7wC2CQ7 QlKvEQgizbpXzjjLw+Jklp5g9UBU6I65hHOKSWBZUayrkH8u6PDCzP4zT1DWxOJpDBlEkq imCrrhvEC8IhxZ7U0YTikiIhAvJt+Hkmj6ALeIPs80K8h8J330GL93DxYWpXj3MDbl7JVq F/cILImBCYvJA+eF/vIyJ1P5LKsN3VzDebtwR4eOhiBOhOSo8ZXxjyfIQBHTMA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1727717911; 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=qp5nwg96y87OpSLZA/vVu33PD/rs5eKJFKqagbVKAw0=; b=zLAKOlMuwI/8W1zaYhVMwXrRAd19gl6cIc+2Bo6R+/1Ij+2JQxJAYemK+4R5ItwK3ZtySU 7fJYn1ykWS5wd8AQ== From: "tip-bot2 for Breno Leitao" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: x86/misc] x86/bugs: Correct RSB terminology in Kconfig Cc: Breno Leitao , Dave Hansen , 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: <172771790961.1365.12944524838461131424.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: 86e39b94cd71a4987f9b98dd2a7d6c826e1c5c98 Gitweb: https://git.kernel.org/tip/86e39b94cd71a4987f9b98dd2a7d6c826= e1c5c98 Author: Breno Leitao AuthorDate: Fri, 13 Sep 2024 05:27:53 -07:00 Committer: Dave Hansen CommitterDate: Mon, 30 Sep 2024 10:30:54 -07:00 x86/bugs: Correct RSB terminology in Kconfig RSB stands for "Return Stack Buffer" in industry literature[1]. Update the kernel Kconfig to use this standard term instead of the current "Return-Speculation-Buffer". This change aligns kernel documentation with widely accepted terminology. The line length reduction triggers text reformatting, but no functional text is altered. [1] https://www.intel.com/content/www/us/en/developer/articles/technical/so= ftware-security-guidance/advisory-guidance/return-stack-buffer-underflow.ht= ml Signed-off-by: Breno Leitao Signed-off-by: Dave Hansen Acked-by: Dave Hansen Link: https://lore.kernel.org/all/20240913122754.249306-1-leitao%40debian.o= rg --- arch/x86/Kconfig | 17 ++++++++--------- 1 file changed, 8 insertions(+), 9 deletions(-) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 2852fcd..2cea5f2 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -2551,15 +2551,14 @@ config MITIGATION_CALL_DEPTH_TRACKING default y help Compile the kernel with call depth tracking to mitigate the Intel - SKL Return-Speculation-Buffer (RSB) underflow issue. The - mitigation is off by default and needs to be enabled on the - kernel command line via the retbleed=3Dstuff option. For - non-affected systems the overhead of this option is marginal as - the call depth tracking is using run-time generated call thunks - in a compiler generated padding area and call patching. This - increases text size by ~5%. For non affected systems this space - is unused. On affected SKL systems this results in a significant - performance gain over the IBRS mitigation. + SKL Return-Stack-Buffer (RSB) underflow issue. The mitigation is off + by default and needs to be enabled on the kernel command line via the + retbleed=3Dstuff option. For non-affected systems the overhead of this + option is marginal as the call depth tracking is using run-time + generated call thunks in a compiler generated padding area and call + patching. This increases text size by ~5%. For non affected systems + this space is unused. On affected SKL systems this results in a + significant performance gain over the IBRS mitigation. =20 config CALL_THUNKS_DEBUG bool "Enable call thunks and call depth tracking debugging"